title stringlengths 0 1.13k | abstract stringlengths 1 15.7k | PMID int64 22 36.5M |
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Increased thyroid blood flow in the hypoechoic lesions in patients with recurrent, painful Hashimoto's thyroiditis at the time of acute exacerbation. | We report two cases with painful Hashimoto's thyroiditis, who developed recurrent fever and painful thyroid. Glucocorticoid treatment was transiently successful but tenderness in the thyroid gland and fever developed when glucocorticoid was tapered. One patient underwent total thyroidectomy uneventfully. As is well known, it is frequently difficult to make differential diagnosis between painful Hashimoto's thyroiditis and subacute thyroiditis particularly at the initial phase. Interestingly, color flow doppler sonography of patient 1 revealed an increased thyroid blood flow in the hypoechoic lesions at the time of acute exacerbation although the serum level of TSH was suppressed. In the other patient, thyroid blood flow was also increased mainly in the hypoechoic lesions when the serum level of TSH was moderately increased, and it disappeared completely after supplementation of prednisolone and L-T4. Since thyroid blood flow in subacute thyroiditis is always decreased, such an increased blood flow in the hypoechoic lesion may be one of clinical characteristics of painful Hashimoto's thyroiditis, and useful for differential diagnosis from subacute thyroiditis. | 18,840,927 |
Application of the Life Change Unit model for the prevention of accident proneness among small to medium sized industries in Korea. | Behavior models have provided an accident proneness concept based on life change unit (LCU) factors. This paper describes the development of a Korean Life Change Unit (KLCU) model for workers and managers in fatal accident areas, as well as an evaluation of its application. Results suggest that death of parents is the highest stress-giving factor for employees of small and medium sized industries a rational finding the viewpoint of Korean culture. The next stress-giving factors were shown to be the death of a spouse or loved ones, followed by the death of close family members, the death of close friends, changes of family members' health, unemployment, and jail terms. It turned out that these factors have a serious effect on industrial accidents and work-related diseases. The death of parents and close friends are ranked higher in the KLCU model than that of Western society. Crucial information for industrial accident prevention in real fields will be provided and the provided information will be useful for safety management programs related to accident prevention. | 18,840,937 |
Vibration-isolating performance of cotton work gloves based on newly issued JIS T8114. | The mean vibration transmissibility values were measured for cotton work gloves commonly used in vibration-generating workplaces to evaluate the vibration isolating performance of cotton work gloves. The mean vibration transmissibility values of work cotton gloves were compared with those of four types of anti-vibration gloves measured in the same way. All the measurements were performed based on the newly issued JIS T8114 that is identical to ISO10819. Also, linear transmissibility values were calculated from the measured data. Cotton work glove samples did not satisfy the requirements specified in JIS T8114. All the test samples showed mean vibration transmissibility values of more than 1.0 for spectra M and H. In contrast, all the anti-vibration gloves tested in this study satisfied the JIS T8114 requirements. The linear transmissibility values of cotton work gloves were consistently higher than those of anti-vibration gloves for spectrum H. The linear transmissibility values of cotton work gloves were steady at about 0.9 up to 200 Hz, then increased with vibration frequency to about 1.0 at 400 Hz. In contrast, the linear transmissibility values of anti-vibration gloves increased with frequency to 1.0 at 30 Hz and then decreased with small peaks at 100 Hz and 300 Hz. Our results suggest that cotton work gloves do not show enough vibration-isolating performance. Therefore, attention should be paid to encouraging the widespread use of anti-vibration gloves in place of cotton work gloves to reduce exposure to hand-arm vibration. | 18,840,938 |
Effects of adjustable sit-stand VDT workstations on workers' musculoskeletal discomfort, alertness and performance. | Adjustable sit-stand workstations, which are designed to allow workers to sit and stand autonomously while working, were examined to identify the effects on workers' musculoskeletal discomfort, alertness and performance. Twenty-four healthy subjects participated in the study. The subjects were required to do an English transcription task for 150 min under the following conditions: 1) sitting at standard workstations (Standard), 2) sitting on a chair with the work surface elevated to standing position (High-chair) and 3) a combination of 10-min sitting and 5-min standing with the same setting as that in the high-chair condition (Sit-stand). The subjective musculoskeletal discomfort scores indicated that High-chair and Sit-stand resulted in relatively higher discomfort levels than the Standard condition. Although the ratio between low-frequency (0.04-0.15 Hz) and high-frequency (0.15-0.4 Hz) components of heart rate variability (LF/HF ratio) in Sit-stand was higher than that in other conditions, there were no significant differences in subjective sleepiness among the three conditions. As for work performance, there was a tendency to be steadily high under the Sit-stand condition compared with other conditions, but not a significant difference. This study revealed that although the use of sit-stand workstations can contribute to keeping workers' arousal level steady, it has an adverse effect in light of musculoskeletal discomfort. | 18,840,942 |
[Iodine concentration in current Japanese foods and beverages]. | In the present study, we determined iodine concentration in commonly consumed foods in Japan. One hundred thirty-nine foods and beverages were purchased from local markets and convenience stores. These samples were examined for iodine concentration by using gas chromatography after ashing or extraction. The iodine concentrations in various food groups were as follows, The concentrations in cereals, sugar, sweeteners, vegetables, fruit, milk, and meat were too low to be detected (<0.05 mg/100 g). The iodine concentrations of algae and dashi (Japanese broth or stock) from algae were <0.05-225 mg/100 g; Japanese seasoning, <0.05-10.5 mg/100 g; and iodine-rich eggs, 1.09-2.00 mg/100 g. Food and beverages with high iodine concentrations need to be taken into account in the nutritional survey for health hazards and benefits in the evaluation of daily nutritional intake. | 18,840,947 |
[Does the population approach increase health inequality? Vulnerable population approach as an alternative strategy]. | The population approach is well recognized as an effective strategy to improve population health, as well as the population-at-risk approach. It aims to decrease risk exposure of the total population through a change of contextual conditions. However, the population approach has the possibility of increasing health inequality because of variation in the effectiveness of the strategy in accordance with the risk exposure. This paper proposes the "vulnerable population approach" as an alternative and supplemental strategy. It aims to decrease health inequalities between socially defined groups, by shifting the distribution of a lower level of risk exposure of the groups through changes in social and environmental conditions that make groups at higher risk. No interventional approach can be singly applied to all health problems. To improve population health, it is important to select the most effective strategy among the three approaches, considering their advantages and limitations, and to adopt a suitable combination of different approaches. | 18,840,948 |
[A new method of measuring temporal resolution for computed tomography]. | In this study, we proposed a new method of measuring temporal resolution using an impulse signal in the time domain in computed tomography (CT). We employed a metal ball with a diameter of 11 mm as the source of the impulse signal, which was shot to a slice plane at a very fast speed during scanning, along the perpendicular direction to the plane. A 4-slice multi detector-row CT (MDCT) system was employed to evaluate the new method, and images for region of interest (ROI) measurement were reconstructed with a z-increment corresponding to a very short time (< or = 0.03 sec). Temporal sensitivity profiles (TSPs) for various helical beam-pitches were obtained by plotting averaged CT values within the ROIs against the temporal axis. The accuracy of the method was examined by comparing the measured TSPs with theoretical TSPs corresponding to respective helical beam-pitches. As a result, the theoretical TSPs and measured TSPs demonstrated high coincidence in all beam-pitches. Since the TSPs indicated the profiles with sharp shapes faithful to the theoretical TSPs, it was proved that the new method had sufficient inherent temporal resolution. It was indicated that the new method we proposed would be an effective method for evaluating temporal resolution in CT. | 18,840,955 |
Immunohistochemical study of cathepsin D in the spinal cords of rats with clip compression injury. | This study examined the temporal expression of cathepsin D protein and its cellular localization in the spinal cords of rats after a clip compression injury to determine the involvement of cathepsin D in spinal cord injury (SCI). Western blot analysis showed a significant increase in the approximately 31-kDa active form of cathepsin D on days 4 and 7 after the SCI, while the level of the approximately 44-kDa inactive form remained relatively unchanged. Immunohistochemistry revealed cathepsin D with constitutive localization in most neurons and some gliocytes in the normal spinal cord to be intensely immuno-detected primarily in CD68-positive activated macrophages/microglia in the SCI lesions. Overall, these findings suggest that cathepsin D plays an important role in the phagocytosis and lysosomal activation of macrophages/microglia during the central nervous system inflammation caused by trauma. | 18,840,968 |
Granulocyte colony-stimulating factor has no adverse effects on atherosclerotic lesions in high cholesterol-fed miniature Swine. | Granulocyte colony-stimulating factor (G-CSF) is widely used to mobilize peripheral blood stem cells, and expected to restore cardiac function for patients with coronary artery diseases as a consequence of progression of atherosclerosis. Safety issues related to the administration of G-CSF to these patients, however, are still under study. The animal model for atherosclerosis was produced by feeding miniature swine a high-cholesterol diet for 3 months. G-CSF (5 or 10 microg/kg/day) was given to the animal model by daily subcutaneous injections for 10 days and 20 main arteries were evaluated pathologically. In addition, the general toxicological effects were studied on clinical signs, body weight, hematology, blood chemistry and pathology. In the G-CSF-treated groups, a variety of changes related to the major pharmacological activity of G-CSF including an increase in white blood cell (WBC) counts were observed. In many arteries, atherosclerotic lesions similar to Type I-V of the proposed classification by the American Heart Association were observed. No effects of the G-CSF treatment were seen on the histopathological findings, incidence, severity or distribution of atherosclerotic lesions. In addition, no infiltration of neutrophils to the lesions was observed. These findings suggest that the administration of G-CSF causes neither exacerbation or modification of atherosclerotic lesions nor adverse changes despite that a sufficient increase in WBC counts could be achieved in the peripheral blood. | 18,840,969 |
Mapping of rRNA gene loci in the mice, Mus musculus molossinus (Japan) and Mus musculus musculus (Russia) by double color FISH. | Ribosomal RNA gene (rDNA) loci of Russian Mus musculus musculus and of Japanese Mus musuculus molossinus were mapped by double color FISH. The total number of rDNA loci was varied from 5 to 12, although the loci on chromosomes 12, 15, 16, 18, and 19 were common to all mice examined. Instead, polymorphisms of the rDNA loci were found on chromosomes 1, 5, 8, 9, 10, 11, 13 and 17. The novel rDNA loci of M. m. musculus were found in Nov/TUA strain on chromosomes 8 and 17. These observations, together with those of previous reports, suggest that the rDNA loci of Mus musculus species are in the evolutionary process of further translocation to other chromosomes. | 18,840,979 |
Chromogranin A as an alternative to 5-hydroxyindoleacetic acid in the evaluation of symptoms during treatment of patients with neuroendocrine Tumors. | Urinary 5-HIAA excretion is a well-known marker in neuroendocrine tumors (NETs), but it has a low sensitivity and the 24-hour collection is inconvenient for patients. Chromogranin A (CgA) is a promising marker, but a thorough evaluation during follow-up is still lacking. 39 patients with metastatic gastrointestinal NETs were monitored during treatment with the long-acting octreotide SandostatinLAR. A comparison was made between serum CgA and urinary 5-HIAA in relation to quality of life (HRQL) assessed by the EORTC QLQ-C30 questionnaire, supplemented with questions specific to carcinoid symptoms. Survival analyses were performed to examine the association between the markers and survival time. Correlations were found between CgA and physical functioning (p = 0.01) and quality of life (p = 0.03), while no significant correlations were observed between 5-HIAA levels and any of the self-reported health outcomes. Cox regression showed an association between CgA levels and survival time (p = 0.02), while no significant association was observed between 5-HIAA levels and survival time. Stronger correlations of CgA compared to 5-HIAA with physical functioning and wellbeing, the convenience of measuring in blood, as well as the prognostic value of CgA for survival, makes CgA the recommended marker in the management of patients with metastatic NETs. | 18,840,995 |
Relation of chronic obstructive pulmonary disease exacerbations to FEV(1)--an intricate tango. | This article provides a brief review of the complex interrelationships that surround chronic obstructive pulmonary disease exacerbations and lung function, particularly FEV(1). Areas of discussion include a consideration of baseline lung function as a risk factor for exacerbation, the magnitude and duration of lung function abnormalities after onset and during recovery from exacerbations, the relation between changes in lung function during an exacerbations and clinical outcomes, and the potential impact of recurrent exacerbations on long-term deterioration in lung function. | 18,840,996 |
Pulse volume changes recorded by air plethysmography during single hemodialysis sessions. | This study investigated whether fluid removal during a hemodialysis (HD) session affects the results of non-invasive pulse volume recording (PVR) on the lower extremities. The results of PVR by air plethysmography (Portable Vascular Laboratory; BioMedix, USA) were compared with bioelectrical impedance analysis (Nutriguard-M device; Data Input, Germany) of the human body before and after a single HD in 28 anuric patients (10 women; 18 men) aged 33-76 years. Changes in the wave amplitude of the PVR correlated with the changes in the patient's weight during HD. Lower stroke volume at the end of HD due to blood volume withdrawal resulted in PVR reduction at the ankle level. Significant Spearman coefficients were found between extracellular water and PVR amplitude changes (r = 0.7, p < 0.01) as well as between intracellular water and PVR (r = 0.6, p < 0.04). To avoid falsification connected with hypervolemia and stroke volume change, the most appropriate time for PVR in vascular diagnosing seems to be the period of a few hours after dialysis session. | 18,841,005 |
Neural correlates of the Clock Drawing Test performance in Alzheimer's disease: a FDG-PET study. | This study aimed to identify the functional neuroanatomical correlates of impaired clock drawing test (CDT) performance in patients with Alzheimer's disease (AD). The CDT was administered to 71 patients with AD, and regional cerebral glucose metabolism (rCMglc) was measured by positron emission tomography (PET). Correlations between CDT scores and rCMglc were examined on a voxel-by-voxel basis. Significant positive correlations were found between CDT performance and rCMglc in the right inferior parietal lobule and right posterior cingulate cortex. These results provide the first PET evidence that poor CDT performance in patients with AD is closely related to the functional decline in the right hemisphere, especially the right parietal cortex. | 18,841,015 |
Multi-center comparison of medial temporal atrophy in patients with Alzheimer's disease--data from the ICTUS study. | To study multi-center variability of medial temporal lobe atrophy (MTA) in patients with Alzheimer's disease (AD) recruited in a European observational study of AD. 117 mild to moderate AD patients from 5 European centers (Amsterdam, The Netherlands; Brescia and Genova, Italy; Mannheim, Germany; Pamplona, Spain) had magnetic resonance imaging scans performed as part of the routine diagnostic examination. MTA was assessed with the visual Scheltens scale. AD patients from Brescia, Genova, Pamplona, and Mannheim had a mean 32% prevalence of no or borderline MTA vs. 62% of patients from Amsterdam (p = 0.002 for the difference between Amsterdam and all the other centers). The peculiar distribution of MTA in the Amsterdam patients may be attributable to younger age (70.7 +/- 8.4 vs. 75.3 +/- 6.8 years, p = 0.002), milder dementia severity (score 0.5 on the clinical dementia rating scale: 52 vs. 23%, p = 0.003), and less frequent depression (14 vs. 49%, p < 0.0005 in Amsterdam vs. all the other centers, respectively). Patients with probable AD recruited in different centers of Europe generally have similar MTA distribution, even if peculiar demographic and clinical findings might explain occasional differences. These results have implications for clinical trials in AD with biological markers as outcome measures. | 18,841,016 |
Triple-negative breast cancer. | Triple-negative breast cancer has been of great interest to oncologists because these cancers do not benefit from hormonal therapies or treatments targeted against human epidermal growth factor receptor 2 receptors. The only systemic therapy currently available is chemotherapy, and prognosis remains poor. We would like to describe recent pathological and genetic advancements and their possible implications on the development of new treatment strategies. Increasing pathological and molecular knowledge has led to a better understanding of breast cancer in general. Triple-negative breast cancer, however, remains a heterogeneous subgroup with difficult-to-define subtypes. New targeted therapies are currently being developed and researched. The recent advances in pathological and molecular knowledge have changed the landscape of breast cancer, with triple-negative breast cancer emerging as a pathological and clinical heterogeneous group. The main challenge lies in the development of new tailored treatment strategies for the various subgroups, with receptor kinase inhibition as the most promising new evolution to date. Further trials are needed to validate these new treatment options. | 18,841,042 |
Erythropoietin in cancer-related anemia. | Erythropoiesis-stimulating agents reduce the transfusion requirements of anemic cancer patients receiving chemotherapy. Risks associated with the use of erythropoiesis-stimulating agents in cancer patients have more recently been identified. Several recently published phase III trials and a meta-analysis have shown an increased risk of venous thromboembolism and a decreased survival in anemic cancer patients treated with erythropoiesis-stimulating agents. To minimize risks associated with erythropoiesis-stimulating agent use in cancer patients, the most recent American Society of Clinical Oncology/American Society of Hematology clinical practice guidelines and Food and Drug Administration recommendations should be followed. | 18,841,051 |
Ilizarov method to correct limb length discrepancy after limb-sparing hemipelvectomy. | Pelvic resection for a sarcoma in young patients is challenging, with significant functional, psychological, and social implications. We report the case of a 26-year-old former Ewing's sarcoma patient in whom the Ilizarov technique was applied to address 6 cm of leg length discrepancy secondary to internal hemipelvectomy with superomedial dislocation of the right femoral head. Fifteen years after the internal hemipelvectomy, the patient underwent distal femoral and bifocal tibial lengthening using circular frames. The results obtained in this patient underline the usefulness of the Ilizarov treatment to increase the quality of life in long-term survivors of pelvic bone cancer. | 18,841,062 |
Effect of crude sulphated polysaccharide from brown algae against acetaminophen-induced toxicity in rats. | This study was conducted to examine the protective role of crude polysaccharide from brown seaweed Sargassum polycystum against acetaminophen-induced abnormality in blood glucose, serum albumin/globulin ratio, and liver glycogen, lactate, and pyruvate. Liver and renal tissue histology was performed to confirm the efficacy of Sargassum polysaccharide. A toxic dose of acetaminophen (800 mg/kg body weight intraperitoneally) induced severe abnormality in all basic parameters with apparent toxicity in liver (enlargement of hepatocytes, loss of cytoplasmic content with disruption in the hepatic plates and sinusoidal dilation) and renal tissue (glomerular damage with congestion of tubules). The isolated liver cells were stained with acridine orange and examined under fluorescence microscope, which revealed that the acetaminophen induced significant damage. In contrast, the rats pretreated with Sargassum polysaccharide (200 mg/kg body weight) daily for 3 weeks did not show liver and renal tissue with these severe aberrations induced by acetaminophen. Histology results were also consistent with analyzed basic biochemical parameters, which confirmed the effectiveness of the crude polysaccharide against acetaminophen-induced abnormality in rats. | 18,841,170 |
Paediatric inflammatory bowel disease in New Zealand. | To determine the incidence, presentation, and initial management of paediatric inflammatory bowel disease in New Zealand. A prospective study in collaboration with the New Zealand Paediatric Surveillance Unit was undertaken between 2002-2003. Paediatricians and healthcare professionals working with children were surveyed monthly for cases of paediatric inflammatory bowel disease. There were 52 cases(30 males); 34 (66%) Crohn's disease, 9 (17%) ulcerative colitis, and 9 (17%) inflammatory bowel disease type unclassified. The estimated incidence of paediatric inflammatory bowel disease, Crohn's disease, and ulcerative colitis were 2.9, 1.9, and 0.5 per 100,000 per year respectively. Mean age at diagnosis was 11 years with a delay of 8.4 months from clinical presentation to diagnosis. 85% were European, while no Maori or Pacific Islanders had Crohn's disease or ulcerative colitis. The most common symptoms at presentation were abdominal pain (63%), rectal bleeding (57%), diarrhoea (55%), and weight loss (43%). 39% of Crohn's disease patients had perianal disease at presentation. Only 18% of the Crohn's disease patients presented with the classic triad of symptoms-abdominal pain, weight loss, and diarrhoea. Haematological laboratory abnormalities were more common in Crohn's disease. 5-aminosalicylic acid agents were the most common initial therapy followed by systemic steroids. 25% of the paediatric inflammatory bowel disease cohort received immunomodulators. The incidence of paediatric inflammatory bowel disease in New Zealand is comparable but at the lower end relative to North America and United Kingdom. There is more Crohn's disease than ulcerative colitis and only a minority of Crohn's disease patients presented with the classic triad of abdominal pain, weight loss, and diarrhoea. 5-aminosalicylic acid preparations and steroids as first line treatment of Crohn's disease were much more common than nutritional therapy. It is rare for New Zealand Polynesian children to develop paediatric inflammatory bowel disease. | 18,841,182 |
High prevalence of gout in patients with Type 2 diabetes: male sex, renal impairment, and diuretic use are major risk factors. | Gout and hyperuricaemia are recognised features of the metabolic syndrome. The objective of this study was to determine the prevalence of gout in patients with diabetes. We studied 292 consecutive outpatients attending diabetes clinics between August and September 2005. A self-reported history of gout was obtained, and was confirmed by clinical chart review. Information regarding associated comorbidities was also recorded. Current treatments were compared with published EULAR guidelines for the management of gout. Gout was confirmed in 0/27 (0%) patients with Type 1 diabetes and 59/265 (22%) of patients with Type 2 diabetes (p<0.01). Prevalence rates varied depending on age and sex, and were highest (41%) in men with type 2 diabetes over the age of 65 years. Multivariate analysis showed that the following variables were independent predictors for gout in patients with Type 2 diabetes: male sex (adjusted OR 4.4, 95%CI 2.1-9.6), impaired renal function (adjusted OR 1.2 for every 10 ml/min reduction in GFR, 95%CI 1.1-1.4), diuretic use (adjusted OR 3.2, 95%CI 1.6-6.6), and high triglycerides (adjusted OR 2.2, 95%CI 1.0-4.7) Only 28/59 (47%) of patients with gout were on urate-lowering therapy. A further 24/59 (41%) met recommended criteria for urate-lowering therapy but were not receiving this medication. This study has demonstrated a high prevalence of gout in patients with Type 2 diabetes. Improved recognition of those at high risk of gout is needed to ensure optimal management of these patients. | 18,841,184 |
When should I do rural general practice? A qualitative study of job/life satisfaction of male rural GPs of differing ages in New Zealand. | There is a shortage of rural general practitioners in New Zealand (NZ), and many are approaching retirement. This qualitative study was undertaken to investigate the perceived advantages and disadvantages of rural general practice at various stages of family life of male NZ-trained GPs. Semi-structured interviews were conducted with 12 male NZ-trained rural GPs from the Waikato and Northland regions during December 2006. Major themes relating to rural general practice as a career were identified and analysed with respect to the family life cycle: no children yet, pre-school children, high school children, or 'empty nest'. Trends in the frequency of themes, and changes in the sentiments within each theme across different stages of family life were noted. Based on the frequency of themes and sentiments, a conceptual picture of the influences of stages of a male rural GP's family life on the GP are discussed. | 18,841,186 |
The secondary abdominal compartment syndrome: not just another post-traumatic complication. | The secondary abdominal compartment syndrome (ACS) is defined as the presence of organ dysfunction with concurrent intra-abdominal hypertension (IAH) in a scenario lacking primary intraperitoneal injury or intervention. This state appears to be related to visceral, abdominal wall and retroperitoneal edema and ascites induced by resuscitation. Despite a diverse range of associated causes such as pancreatitis, intra-abdominal sepsis, cardiac arrest, thermal injury and extraperitoneal trauma, this class of ACS is characterized by the presence of shock requiring aggressive fluid resuscitation. Secondary ACS is an extreme condition along a continuum of raised intra-abdominal pressure (IAP) that is pathoneumonic when associated with new overt organ failure. When IAP is above normal but is not associated with organ failure, IAH is diagnosed. Because these conditions are common among critically ill patients, the measurement of IAP is crucial. It is unclear whether preventing IAH reduces progression to ACS or influences outcomes. When overt ACS is confirmed, immediate surgical decompression of the patient's abdomen via a standard laparotomy is usually required. Because many disease processes resulting in critical illness require aggressive fluid resuscitation as a primary therapy, it is likely that secondary ACS is much more common than previously believed. Further study is needed. | 18,841,232 |
SNPinProbe_1.0: a database for filtering out probes in the Affymetrix GeneChip human exon 1.0 ST array potentially affected by SNPs. | The Affymetrix GeneChip(R) Human Exon 1.0 ST array (exon array) is designed to measure both gene-level and exon-level expression in human samples. This exon array contains approximately 1.4 million probesets consisting of approximately 5.4 million probes and profiles over 17,000 well-annotated gene transcripts in the human genome. As with all expression arrays, the exon array is vulnerable to SNPs within probes, because these SNPs can affect the hybridization of the probes and thus produce misleading expression values. In some cases, this could result in dramatic fluctuations of the exon-level expression. For this reason, we performed a genome-wide search for SNPs within regions that hybridize to probes by evaluating approximately 18 million SNPs in dbSNP (Build 129) and about 5.4 million probes in the exon array. We identified 597,068 probes within 350,382 probe sets that hybridized to regions containing SNPs. These affected probes and/or probesets can be filtered in the data processing procedure thus controlling for potential false expression phenotypes when using this exon array. http://cid-fb2a64e541add2be.skydrive.live.com/browse.aspx/Affy%7C_HuEx%7C_1.0ST?uc=2. | 18,841,244 |
THE RACE/ETHNICITY DISPARITY IN MISDEMEANOR MARIJUANA ARRESTS IN NEW YORK CITY. | RESEARCH SUMMARY: This article examines the growth in marijuana misdemeanor arrests in New York City (NYC) from 1980 to 2003 and its differential impact on blacks and Hispanics. Since 1980, the New York City Police Department (NYPD) expanded its use of arrest and detention for minor offenses under its quality-of-life (QOL) policing initiative. Arrest data indicate that during the 1990s the primary focus of QOL policing became smoking marijuana in public view (MPV). By 2000, MPV had become the most common misdemeanor arrest, accounting for 15% of all NYC adult arrests and rivaling controlled substance arrests as the primary focus of drug abuse control. Of note, most MPV arrestees have been black or Hispanic. Furthermore, black and Hispanic MPV arrestees have been more likely to be detained prior to arraignment, convicted, and sentenced to jail than their white counterparts. POLICY IMPLICATIONS: In light of the disparities, we recommend that the NYPD consider scaling back on MPV enforcement and reducing the harshness of treatment by routinely issuing Desk Appearance Tickets when the person is not wanted on other charges, so that most MPV arrestees would not be detained. Furthermore, we recommend that legislators should consider making smoking marijuana in public a violation and not a misdemeanor. Lastly, we suggest ways that NYC could monitor the effectiveness of these policy modifications to assure that the city continues to meet its goals for order maintenance. | 18,841,246 |
Polyelectrolyte multilayer films of controlled stiffness modulate myoblast cells differentiation. | Beside chemical properties and topographical features, mechanical properties of gels have been recently demonstrated to play an important role in various cellular processes, including cell attachment, proliferation, and differentiation. In this work, we used multilayer films made of poly(L-lysine)/Hyaluronan (PLL/HA) of controlled stiffness to investigate the effects of mechanical properties of thin films on skeletal muscle cells (C2C12 cells) differentiation. Prior to differentiation, cells need to adhere and proliferate in growth medium. Stiff films (E(0) > 320 kPa) promoted formation of focal adhesions and organization of the cytoskeleton as well as an enhanced proliferation, whereas soft films were not favorable for cell anchoring, spreading or proliferation. Then C2C12 cells were switched to a low serum containing medium to induce cell differentiation, which was also greatly dependent on film stiffness. Although myogenin and troponin T expressions were only moderately affected by film stiffness, the morphology of the myotubes exhibited striking stiffness-dependent differences. Soft films allowed differentiation only for few days and the myotubes were very short and thick. Cell clumping followed by aggregates detachment could be observed after ~2 to 4 days. On stiffer films, significantly more elongated and thinner myotubes were observed for up to ~ 2 weeks. Myotube striation was also observed but only for the stiffer films. These results demonstrate that film stiffness modulates deeply adhesion, proliferation and differentiation, each of these processes having its own stiffness requirement. | 18,841,249 |
GOVERNING GENETIC DATABASES: COLLECTION, STORAGE AND USE. | This paper provides an introduction to a collection of five papers, published as a special symposium journal issue, under the title: "Governing Genetic Databases: Collection, Storage and Use". It begins by setting the scene, to provide a backdrop and context for the papers. It describes the evolving scientific landscape around genetic databases and genomic research, particularly within the biomedical and criminal forensic investigation fields. It notes the lack of any clear, coherent or coordinated legal governance regime, either at the national or international level. It then identifies and reflects on key cross-cutting issues and themes that emerge from the five papers, in particular: terminology and definitions; consent; special concerns around population genetic databases (biobanks) and forensic databases; international harmonisation; data protection; data access; boundary-setting; governance; and issues around balancing individual interests against public good values. | 18,841,252 |
Isolated right ventricular infarction due to occlusion of the right ventricular branch in the absence of percutaneous coronary intervention. | Isolated right ventricular myocardial infarction accounts for only 3% of all infarctions. It has previously been reported as a complication of percutaneous coronary intervention involving the right coronary artery secondary to occlusion of the right ventricular branch. In the present report, a patient is described in whom isolated right ventricular myocardial infarction developed due to occlusion of the right ventricular branch of the right coronary artery in the absence of percutaneous intervention. | 18,841,260 |
Protective effects of activated protein C in sepsis. | Sepsis remains a complex syndrome associated with significant morbidity and mortality. It is now widely accepted that the pathways of inflammation, coagulation, apoptosis, and endothelial permeability are intimately linked in sepsis pathophysiology. The clinical success of activated protein C (APC), a natural anticoagulant, in reducing mortality in patients with severe sepsis has fuelled basic and preclinical research on the protective effects of this molecule. Over the past 15 years, impressive research advances have provided novel insights into the multifunctional activities of APC. APC is now viewed not only as an anticoagulant, but also as a cell signaling molecule that dampens the excessive or insufficiently controlled host response during sepsis. This review attempts to summarize the pleiotropic activities of APC with focus on its ability to inhibit coagulation, inflammation, apoptosis, and endothelial barrier breakdown. A comprehensive PUBMED literature review up to May 2008 was conducted. | 18,841,279 |
Effects of omega-3 acid ethyl esters and aspirin, alone and in combination, on platelet function in healthy subjects. | Omega-3 fatty acids (n-3 FA) from oily fish are clinically useful for lowering triglycerides and reducing risk of heart attacks. Accordingly, patients at risk are often advised to take both aspirin and n-3 FA. However, both of these agents can increase bleeding times, and the extent to which the combination inhibits platelet function is unknown. The purpose of this pilot study was to determine the effects of a prescription omega-3 FA product (P-OM3) and aspirin, alone and in combination, on platelet aggregation assessed by whole blood impedance aggregometry (WBA). Ten healthy volunteers provided blood samples on four separate occasions: Day 1, baseline; Day 2, one day after taking aspirin (2 x 325 mg tablets); Day 29, after 28 days of P-OM3 (4 capsules/day); and Day 30, after one day of combined P-OM3 and aspirin. WBA was tested with two concentrations of collagen, with ADP and with a thrombin receptor activating peptide (TRAP). Compared to baseline, aspirin alone inhibited aggregation only with low-dose collagen stimulation; P-OM3 alone did not inhibit aggregation with any agonist; and combined therapy inhibited aggregation with all agonists but TRAP. Significant interactions between interventions were not observed in response to any agonist. In conclusion, P-OM3 alone did not inhibit platelet aggregation, but did (with two agonists) when combined with aspirin. Since previous studies have not reported a clinically significant risk for bleeding in subjects on combined therapy, P-OM3 may safely enhance the anti-platelet effect of aspirin. | 18,841,286 |
The biological and ethical basis of the use of human embryonic stem cells for in vitro test systems or cell therapy. | Human embryonic stem cells (hESC) are now routinely cultured in many laboratories, and differentiation protocols are available to generate a large variety of cell types. In an ongoing ethical debate opinions of different groups are based on varying sets of religious, historical, cultural and scientific arguments as well as on widely differing levels of general information. We here give an overview of the biological background for non-specialists, and address all is- sues of the current stem cell debate that are of concern in different cultures and states. Thirty-five chapters address embryo definition, potential killing and the beginning of human life, in addition to matters of human dignity, patenting, commercialisation, and potential alternatives for the future, such as induced pluripotent (reprogrammed) stem cells. All arguments are compiled in a synopsis, and compromise solutions, e.g. for the definition of the beginning of personhood and for assigning dignity to embryos, are suggested. Until recently, the major application of hESC was thought to be transplantation of cells derived from hESC for therapeutic use. We discuss here that the most likely immediate uses will rather be in vitro test systems and disease models. Major and minor pharmaceutical companies have entered this field, and the European Union is sponsoring academic research into hESC-based innovative test systems. This development is supported by new testing strategies in Europe and the USA focussing on human cell-based in vitro systems for safety evaluations, and shifting the focus of toxicology away from classical animal experiments towards a more mechanistic understanding. | 18,841,314 |
Abnormal short latency afferent inhibition in early Alzheimer's disease: a transcranial magnetic demonstration. | The pathogenesis of Alzheimer's disease (AD) appears to involve several different mechanisms, the most consistent of which is an impairment of cholinergic neurotransmission; however, there is controversy about its relevance at the early stage of disease. A transcranial magnetic stimulation (TMS) protocol based on coupling peripheral nerve stimulation with motor cortex TMS (short latency afferent inhibition, SAI) may give direct information about the function of some cholinergic pathways in the human motor cortex. We evaluated SAI in a group of patients with early diagnosis of AD and compared the data with that from a control group. The amount of SAI was significantly smaller in early AD patients than in controls. This study first provides physiological evidence that a central cholinergic dysfunction occurs in the earlier stages of AD. Identification of SAI abnormalities that occur early in the course of AD will allow earlier diagnosis and treatment with cholinergic drugs. | 18,841,323 |
Screening of DHFR-binding drugs by MALDI-TOFMS. | The class of antimetabolite chemotherapeutical agents has been used to treat cancers in humans for almost 50 years and gives significant results by binding dihydrofolate reductase (DHFR), a key enzyme in DNA synthesis. Therefore, finding new active compounds inhibiting DNA synthesis through their binding to DHFR is of prime interest. The aim of this work is to describe a protocol designed to study the binding of compounds to DHFR. This screening protocol involves matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) detection of target-bound compounds. Firstly, a screening protocol is developed and proves to be a simple, fast, and specific method to characterize the binding capability of a compound. Secondly, the possibility of determining the relative affinities of DHFR-binding compounds by comparing MALDI-TOFMS data is discussed. A ratio is calculated for a compound X such as R(X) = A.I.(denaturation)(X)/A.I.(direct)(X) (where AI(direct) and AI(denaturation) are the average absolute intensities of a binding compound X before and after denaturation of DHFR). It is shown that by using this protocol, one can characterize the strength of the binding of different compounds. These two strategies are then applied to screen green tea (Camellia sinensis) extracts for DHFR-binding compounds, and epigallocatechin gallate is shown to be an active compound with a relative affinity between those of pyrimethamine and methotrexate. | 18,841,351 |
Magnetic nanoparticle imaging by means of minimum norm estimates from remanence measurements. | In magnetic nanoparticle imaging, magnetic nanoparticles are coated and functionalized to bind to specific targets. After measuring their magnetic relaxation or remanence, their distribution can be determined by means of inverse methods. The reconstruction algorithm presented in this paper includes first a dipole fit using a Levenberg-Marquardt optimizer to determine the reconstruction plane. Secondly, a minimum norm estimate is obtained on a regular grid placed in that plane. Computer simulations involving different parameter sets and conditions show that the used approach allows for the reconstruction of distributed sources, although the reconstructed shapes are distorted by blurring effects. The reconstruction quality depends on the signal-to-noise ratio of the measurements and decreases with larger sensor-source distances and higher grid spacings. In phantom measurements, the magnetic remanence of nanoparticle columns with clinical relevant sizes is determined with two common measurement systems. The reconstructions from these measurements indicate that the approach is applicable for clinical measurements. Our results provide parameter sets for successful application of minimum norm approaches to Magnetic Nanoparticle Imaging. | 18,841,404 |
Response of phytoplankton community to low-dose atrazine exposure combined with phosphorus fluctuations. | The effects of atrazine on a controlled phytoplankton community derived from a natural freshwater wetland exposed to low doses of this photosynthesis-inhibiting herbicide were examined. The community was exposed for 7 weeks to doses of 0.1, 1, and 10 microg L(-1) atrazine, combined with changes in nutrient concentration, and the photosynthetic activity, biomass, and community structure were noted during the experiment. Responses of the phytoplankton community were examined in terms of photosynthetic activity, biomass, and community structure. Significant effects of atrazine on the phytoplankton assemblage, in terms of primary production and community structure, were highlighted, even at doses as low as 1 and 0.1 microg L(-1), when associated with phosphorus fluctuations. The most abundant Chlorophyceae decreased in concentration with increasing atrazine dose, whereas cyanobacteria were more tolerant to atrazine, particularly with increased nutrient supply. The subinhibitory doses of atrazine used in the present study confirmed the higher sensitivity of long-term exposure of multispecies assemblages under resource competition. Our study supports the emerging hypothesis that the increasing prevalence of cyanobacterial blooms in European aquatic systems may result from a combination of unbalanced nutrient enrichment and selective pressures from multiple toxicants. | 18,841,407 |
Management of mandibular fractures in a developing country: a review of 314 cases from two urban centers in Nigeria. | This study was designed to establish the current demographic and treatment patterns of mandibular fractures in two urban centers (Lagos University Teaching Hospital, Lagos, and National Hospital, Abuja) in Nigeria. All cases of mandibular fractures diagnosed and treated at the Department of Oral and Maxillofacial Surgery, Lagos University Teaching Hospital, Lagos (1998-2007) and Department of Oral and Maxillofacial Surgery, National Hospital, Abuja, Nigeria (2001-2007) were reviewed. Data collected included age, sex, etiology of fracture, anatomic site of fracture, associated maxillofacial fracture, types of treatment, and postoperative complications. The highest incidence of mandibular fractures (49.3%) occurred in the age group 21-30 years and the lowest in the age group 0-10 years, with male preponderance in nearly all age groups. Road traffic crashes (RTC) were the leading cause (67.5%), followed by assault (18.8%), and gunshot. Of the RTC cases, 85 (40%) were sustained from motorcycle-related crashes. The commonest site of fracture was the body of the mandible (n = 137), followed by the angle (n = 114). The majority (83.1%) were treated by closed reduction using intermaxillary fixation, 13.1% by open reduction and internal fixation, and 3.8% had conservative treatment. Mandibular fractures are commonest during the third decade of life and in men, with almost half of the cases due to of road traffic crashes. RTC was the leading cause of mandibular fractures in all age groups. Motorcycle-related mandibular fractures seem to be increasing in Nigeria. There is a need to enforce legislation designed to prevent RTC to reduce maxillofacial fractures in Nigeria. | 18,841,410 |
Home ranges of bottlenose dolphins (Tursiops truncatus) in the Indian River Lagoon, Florida: environmental correlates and implications for management strategies. | Photo-identification surveys conducted between 2002 and 2005 were used to determine dolphin home ranges and site fidelity within the Indian River Lagoon (IRL), Florida. The IRL was divided into six segments based on hydrodynamics and geographic features for purposes of characterization. Among the 615 dolphins with identifiable dorsal fins, 339 had > or =6 sightings and were used in segment and linear range analyses. The majority (98%) of dolphins were seen in < or =3 consecutive segments (331/339); of these, 44% (144/331) occurred in two segments, and 33% (109/331) in one segment. No dolphins were observed in all six segments. The largest number of dolphins was sighted in segment 1C (North Indian River). However, the highest density of dolphins was found in segment 2 (North-Central Indian River). Re-sighting rates for dolphins with > or =6 sightings ranged from 2.8 to 8.7 times observed. The mean linear home range varied from 22 to 54 km. Distributional analyses indicated that at least three different dolphin communities exist within the IRL: Mosquito Lagoon, and the North and South Indian River. No statistically significant correlations were found between the total number or density per km(2 )of dolphins and surface water area, salinity, or contaminant loads within segments of the lagoon. These results suggest that dolphins do not selectively avoid areas with relatively unfavorable water quality. IRL dolphins should be studied on smaller spatial scales than currently practiced, and potential anthropogenic impacts should be evaluated based on geographic partitioning. | 18,841,416 |
Concomitant laparoscopic adjustable gastric banding and laparoscopic cholecystectomy in a super-obese patient with situs inversus totalis who previously underwent intragastric balloon placement. | Laparoscopic adjustable gastric banding has been increasingly performed since its introduction in 1990. Situs inversus totalis is a rare anomaly in which transposition of organs to the opposite side of the body occurs. Laparoscopic gastric banding in such few patients has been reported in the literature. We discuss a super-obese patient with situs inversus totalis and asymptomatic cholelithiasis who previously underwent endoscopic intragastric balloon placement in preparation for bariatric surgery. Afterwards, laparoscopic cholecystectomy and laparoscopic adjustable gastric banding were performed in the same session. Special attention is paid to the literature review and the mirror-image modification of the laparoscopic cholecystectomy and laparoscopic gastric banding procedures. With preoperative assessment, modifications in the surgical team, and equipment, the operation can be performed safely. | 18,841,426 |
The utility of the Beck Depression Inventory in a bariatric surgery population. | The Beck Depression Inventory (BDI) is commonly used in bariatric surgery psychological assessments. However, several items may be measuring physical consequences of obesity (e.g., sleep disturbance, chronic pain, or sexual dysfunction) rather than depressive symptoms. Bariatric surgery candidates (n = 210) completed a series of assessments including the BDI, a chronic pain assessment, and a semistructured clinical interview. Total BDI scores, subscale scores, and endorsement patterns of somatic versus cognitive-affective items were examined based on (1) the presence or absence of a depressive diagnosis or (2) the presence or absence of chronic pain, and optimal cut points were determined. Both the total BDI and cognitive-affective subscale had good discriminating accuracy between participants with and without depression, with an optimal cut point of 12 for the BDI and 7 for the cognitive-affective subscale. Bariatric surgery candidates with chronic pain had significantly higher mean total scores on the BDI (M = 12.5 +/- 7.5) than those without chronic pain (M = 9.02 +/- 6.7; p < 0.01), and those with chronic pain were significantly more likely to endorse many of the physical items than those without chronic pain. The BDI, with or without the somatic items, appears to be a reasonable screening measure for depressive symptoms among bariatric surgery candidates and the subpopulation of those with chronic pain, although future investigations may wish to examine whether other measures would have improved discrimination accuracy. | 18,841,428 |
Reliability across studies from the functional assessment of cancer therapy-general (FACT-G) and its subscales: a reliability generalization. | The aim of this study was to conduct a reliability generalization of the Functional Assessment of Cancer Therapy-General (FACT-G) and its subscales to examine variation in score reliability across all published studies. We reviewed 344 publications based on predetermined criteria. About 78 published studies reported Cronbach's Alpha reliability coefficients from their study in which data were collected. Sample size based weights were applied, and studies were coded on several scale and demographic characteristics. Using independent samples t tests, we examined associations between study characteristics and internal consistency variability. Average FACT-G score reliability was .88 (subscales ranged between .71-.83). Three variables produced small, statistically significant (P < or = .05) eta squared effects (ranging between .06-.21) due to different sources of variation in the FACT-G and subscales: ethnicity, cancer type, and study type-all of which appeared to be related to disproportionate representation of studies with the majority including Caucasian samples, mixed cancer samples, and validation type studies. The FACT-G and its subscales demonstrated acceptable reliability evidence across observed studies, without substantial variability due to scale or demographic characteristics. | 18,841,493 |
Reliability and validity of the Korean version of UKU-SERS-Pat in patients with bipolar disorder. | Poor drug compliance caused by side effects is an important factor affecting clinical outcomes. Thus reliable and valid rating scales to accurately evaluate the side effects of medications in their early stages are needed. This study aimed to develop the Korean version of the Udvalg for Kliniske Undersøgelser (UKU) Side Effects Rating Scale for Patients (K-UKU-SERS-Pat) to comprehensively measure side effects of psychotropic medications by the self-report method and to examine reliability and validity in patients with bipolar disorder (BD). Ninety-three patients diagnosed with BD by DSM-IV criteria were recruited in this study. The patients completed the K-UKU-SERS-Pat. The Side Effects Rating Scale for Clinicians was administered simultaneously. In 19 patients, the K-UKU-SERS-Pat was conducted twice on a 3-day interval to examine the test-retest reliability. Depressive symptoms were evaluated with the Hamilton Depression Rating Scale-17 and (hypo)manic symptoms with the Young Mania Rating Scale. The test-retest reliability (rho=0.89, P<0.01) and the concurrent validity (rho=0.80, P<0.01) of K-UKU-SERS-Pat were good. However, patients had a tendency to report their side effects more frequently and severely than clinicians. The K-UKU-SERS-Pat is proved to be a reliable and valid tool to comprehensively and practically monitor the side effects of psychotropics. | 18,841,509 |
Risk factors of the failure of surfactant treatment by transient intubation during nasal continuous positive airway pressure in preterm infants. | We sought to identify risk factors and neonatal outcomes associated with the failure of the INSURE method ( INtubation- SURfactant- Extubation) during nasal continuous positive airway pressure for preterm infants with respiratory distress syndrome. We used a retrospective analysis of the prenatal histories, clinical courses, and laboratory data of all inborn infants with gestational age 27 to 34 weeks and respiratory distress syndrome treated with INSURE method. Infants were categorized into two groups: INSURE failure group and INSURE success group. One hundred nine infants were eligible to the study. INSURE failure was registered in 35 infants (32.1%). After control for confounding variables, INSURE failure was significantly associated with arterial partial pressure of carbon dioxide (adjusted odds ratio [OR] = 1.82; 95% confidence interval [CI] = 1.76 to 90.56), mean arterial-to-alveolar oxygen tension ratio (adjusted OR = 1.13; 95% CI = 1.06 to 85.34) and severe radiological grade (adjusted OR = 1.31; 95% CI = 1.15 to 70.16). Positive predictive values of these variables were 70, 75, and 55%, respectively. Patent ductus arteriosus and mortality rates were significantly higher in INSURE failure group. Arterial partial pressure of carbon dioxide, arterial-to-alveolar oxygen tension ratio, and severe radiological grade are predictors of the failure of INSURE method in preterm infants with respiratory distress syndrome. However, a prospective randomized controlled trial is needed to determine whether or not infants at risk for INSURE failure are better off being treated with mechanical ventilation. | 18,841,536 |
[Treatment of headaches among the Aborigines of Tierra de Fuego. A comparison with other anthropological studies]. | Several different indigenous groups (Yamana, Selk'nam, Alacaluf, Haush) used to inhabit the Patagonian region of Tierra de Fuego, but are now extinct. To analyse the healing practices that these prehistoric aborigines used to treat headaches and to compare them with those observed in other anthropological studies. The article reviews the most important manuscripts from the end of the 19th century written by anthropologists and missionaries who were in contact with these peoples (Bridges, Hyades, Gusinde). The Yamana, or 'canoero' Indians, lived in the coastal areas and ate mostly seals and shellfish. The Selk'nam were nomadic hunter-gatherers who lived in the northern part of the Isla Grande. The Yekamush were the Yamana healers. The chief palliative treatments for pain were fasting, drinking cold water and the application of localised heat and massages. Headaches were one of the most prevalent conditions among the Yamana. Treatment for headaches consisted in hitting the patient's head with prickly chaura (Pernettya mucronata) leaves, which produces a small amount of bleeding, or the use of fresh nettle leaves, which were held in place with a headband. The Selk'nam used the term kwaketan to refer to the feeling of sadness with pain, while the term kwake meant 'illness'. Other common ways of treating headaches included ritual ceremonies with chanting, the detection of painful points, and the absorption and expulsion of the kwake. Headaches were one of the most frequent neurological pathologies among these prehistoric Fuegian aborigines, in line with the observations made in other transcultural studies conducted on present-day native cultures. | 18,841,550 |
[The mutation and expression of MUS81 gene in laryngeal squamous cell carcinoma]. | To investigate the association of mutations and expression of MUS81 gene with the tumorigenesis and progression of laryngeal squamous cell carcinoma (LSCC). PCR-SSCP and DNA sequencing were carried out to examine mutations at exons 9 and 10 of MUS81 gene in 42 LSCC samples, with paired adjacent normal laryngeal tissues (PANLs) as control. Semi-quantitative RT-PCR and Western blot were used to detect the expression of MUS81 gene in the specimens. No mutation was detected in the control group. Among the 42 LSCC specimens, nineteen (45.2%) were found to harbor mutations, including 11(26.2%) occurring within exon 9, and 8 (19%) within exon 10. Seventeen (40.48%) samples showed lower mRNA level of the MUS81 gene (P<0.01), and same proportion of samples had lower protein level (P<0.01), suggesting that MUS81 gene was similarly down-regulated at both mRNA and protein levels in the LSCC samples. Furthermore, mutations of MUS81 gene did not significantly correlate with TNM stages, age and lymphoid node metastasis (P>0.05). Nor did the expression of MUS81 gene with the TNM stages, age and lymphoid node metastasis in LSCC (P>0.05). Mutations and abnormal expression of MUS81 gene in the LSCC tissues were observed, which suggested that abnormalities of MUS81 gene may play an important role in the tumorigenesis of LSCC. | 18,841,572 |
[Clinical and cytogenetic features of hematologic malignancies associated with acquired trisomy 21]. | To investigate the association between trisomy 21 abnormalities and the clinical and cytogenetic features of hematologic malignancies. Chromosome preparations were made on bone marrow cells by using direct method and/or unstimulated short-term cultures. Karyotypes were analyzed by R-banding. Thirteen patients (1.5%) with acute myeloid leukemia (AML) including 6 cases of M5b, 8 (2.2%) with acute lymphoblastic leukemia (ALL) and 4 cases with other hematologic malignancies had acquired trisomy 21, and in 13 patients it occurred as the sole cytogenetic abnormality. The remaining had combination with other abnormalities. The median survival for the 19 patients with trisomy 21 was 9 months. M5b was the major type in AML with sole acquired trisomy 21.Trisomy 21 as the sole abnormality appeared to have a poor prognosis. | 18,841,576 |
Experiments in payment. | Everyone agrees: The nation's health care payment system is a mess. Today, dozens of reform ideas are being tested, and while there is little coordination, the goal is the same: Get more value for the health care buck in terms of quality and results. Some experts say this is the beginning of a "quiet revolution" in payment. We look at five of the most ambitious projects. | 18,841,682 |
Host-microbe symbiosis: the squid-Vibrio association--a naturally occurring, experimental model of animal/bacterial partnerships. | Many, if not most, animals have specific symbiotic relationships with bacterial partners. Recent studies suggest that vertebrates create alliances with highly complex consortia of hundreds to thousands of prokaryotic phylotypes. In contrast, invertebrates often have binary associations, i.e., relationships with a population of a single bacterial species. In this chapter, the association between the Hawaiian sepiolid squid Euprymna scolopes and the marine luminous bacterium Vibrio fisheri is highlighted. This symbiosis offers a relatively simple, yet naturally occurring, association that can be experimentally manipulated. Studies of this system are providing insight into the precise mechanisms by which a beneficial animal-bacterial symbiosis can be established and maintained. | 18,841,707 |
Effect of energy density on color stability in dental resin composites under accelerated aging. | The effects of the energy density that is used for polymerization on properties of dental resin composites are well known. However, few studies relate color stability to this factor. The aim of this study was to assess color changes (deltaE*), in vitro, in terms of accelerated aging under UV exposure of specimens prepared with different energy densities. Four commercial dental resin composites were included in the study. Thirty six specimens were prepared for each one of them, following the procedure established by ISO 4049 Standard, and assigned to three groups: A (3.75 J/cm2), B (9 J/cm2), C (24 J/cm2). Each group was further subdivided into four subgroups: 1 (no aging), 2 (500 hours aging), 3 (1000 hours aging) and 4 (1500 hours aging). The results were analyzed by means of ANOVA and Tukey's test (alpha = 0.05) to determine the effect of the factors. Correlation was performed in order to determine the possible relationship among variables. Energy density is not a significant factor in color stability. However aging is directly proportional to color changes. deltaE* depends on filler size; hybrid material presented deltaE* of 2.1(0.5), 2.4(0.6) and 3.3(0.3) at 500, 1000 and 1500 hours of accelerated aging respectively, and nanofilled material showed deltaE* of 3.0(0.6), 4.5(1.2) and 5.9(0.6) at the same times respectively. It can be concluded that deltaE* does not depend on energy density; however other factors are involved in color change. Further studies in this area are warranted. | 18,841,740 |
Film thickness of resin cements used with adhesive systems. | The final film thickness of a resin adhesive and a resin cement could be affected by previous polymerization of the adhesive systems on dentin surfaces. The aim of this work was to evaluate changes in the film thickness of dual resin based cements with their adhesives as a function of polymerization of the latter on dentin surfaces. The materials used were: RelyX ARC (R) + Single Bond (SB) and Variolink base (VB) and high (HV) or low (LV) viscosity catalyst + Syntac Classic (S) or Excite DSC (E); 56 human dentin discs and 56 composite resin discs (Z250). Dentin disc surfaces were treated with 35% phosphoric acid (except for S) and the adhesive system was either polymerized or not polymerized. A 0.05 ml increment of cement mixture was placed on the dentin disc and covered with the resin disc. A 25 N load was applied for ten minutes and then, the combined thickness was measured with a digital micrometer. Sample size (n) was 4 for each cement or condition. A two-way analysis of variance was performed with a level of significance of p < 0.05. The mean film thickness (and standard deviations) in microm, with and without previous polymerization of the adhesive layer, were: R+SB: 16.50 (2.64) and 17.00 (1.41); VB+S: 21.75 (5.37) and 62.25 (0.95); VB LV+S: 24.50 (3.87) and 72.75 (1.89); VB HV+S: 28.75 (8.46) and 93.00 (53.63); VB+E: 31.75 (8.38) and 42.75 (4.34); VB LV+E: 47.75 (2.50) and 45.75 (3.20); VB HV+E: 49.25 (25.50) and 45.75 (2.75). Significant differences (p < 0.01) were found for the cements and polymerization condition as well as for the interaction between them. Instructions regarding polymerization of the adhesive layer must be followed when adhesive systems are used in combination with dual polymerized resin based cements. Otherwise, final film thickness of the adhesive and the resin cement could be affected. | 18,841,743 |
Relationship between oral health in children and poverty related factors. | The aim of this investigation was to analyze the variables related to poverty and its influence on oral health in children living in a suburban area ofBuenos Aires, Argentina. The study population consisted of 1,049 children. 579 children at social risk (Group I) were recruited from five neighborhoods with critical lacks (Katzman, 1989) and divided into 2 subgroups according to age: (A) preschool children and (B) school children. 470 preschool and school children from the same district but living in homes without critical lacks served as controls (Group II). The following variables associated with poverty were analyzed: (a) parents' instructional level, (b) employment conditions, and (c) accessibilty to regular oral health care. Group I comprised children from five neighborhoods categorized according to the incidence rate of each variable. Clinical examinations were performed under similar conditions by three calibrated investigators. DMFS, dmfs, total DMFS + dmfs, DS + ds, Care Index and Loe & Silness plaque index were recorded and analyzed using Students t test, ANOVA and Chi square test (level of significance p < 0.05). Dental indicators were significantly higher in Group I than in Group II. The dental caries indicators increased as the incidence rate of the poverty-related variables rose. The highest number of children with high cariogenic risk was observed in neighborhoods with the highest social risk (c2 = 30.48; p < 0.005). The analyzed poverty-related variables seemed to be associated with factors that play a role in the dental caries development process in school and preschool children living in the Metropolitan area of Buenos Aires. | 18,841,746 |
Passive drainage through the vestibular oblique incision in impacted inferior third molar surgery: a preliminary study. | The aim of the present study was to clinically evaluate the variables pain, swelling and trismus when two different suture techniques were applied in surgery of impacted lower third molars. The sample comprised 20 patients of both genders participating in the clinical trial at the Division of Oral and Maxillofacial Surgery, with an indication for the removal of bilaterally impacted lower third molars. They were divided into test and control groups. Complete suture was performed on the free and attached gums in the control group and only on the attached gum of the oblique vestibular incision in the test group. The results showed that the fact that the drainage of fluid through the suture was not obliterated led to diminution of pain 48 hours after surgery. No statistically significant differences were observed in relation to swelling, which diminished gradually in both groups. As regards the variable trismus, the test group presented a greater mouth opening throughout the evaluation, being statistically significant at 7 days. The probing depth, three months postoperatively, was found to be greater in the control group. This difference reached statistical significance for the vestibular distal region of the adjacent second molar. It is concluded that the strategy of not suturing the free gum of the oblique vestibular incision in the extraction of impacted lower third molars leads to the diminution of immediate painful symptomatology, but has no influence on the swelling. | 18,841,747 |
Protein content in irrigating solutions in contact with pulp tissue. | Endodontic irrigating solutions may have different effects, one of which is dissolving pulp tissue. The capacity of different irrigants to dissolve vital and necrotic pulp tissue was evaluated in vitro by means of a quantitative and qualitative study of total soluble pulp protein. Vital pulps and pulps with induced necrosis from young bovine teeth were used. Pulp was cut into smaller pieces, weighed and placed in 1 ml of 1% and 2.5% sodium hypochlorite, 1% and 5% calcium hydroxide, 0.2% chlorhexidine gluconate, 1% tea and distilled water as a control, and kept at 37 degrees. Samples of 20 microl were taken at 30 and 90 minutes and 20 hours. Total protein was dosed using the Lowry method and soluble protein bands were determined by electrophoresis (12% SDS-Page). The results were analyzed using Anova. Chemical analysis of the electrophoretic runs of bovine pulp protein showed that both concentrations of sodium hypochlorite and calcium hydroxide produce denaturation of proteins. No solvent action was found with chlorhexidine, tea or distilled water. | 18,841,748 |
[Limited determination of trace toxical aconitine alkaloid in guifudihuang pills]. | To establish a capillary electrophoresis with field-amplified sample stacking method for the separation and determination of aconitine alkaloid in Guifudihuang pills. An uncoated fused-silica capillary column (50 microm x 43 cm, effective length 35 cm) was used. The running buffer was 50 mmol x L(-1) phosphate electrolyte solution (pH 4.6)-methanol (8:2). The runing voltage was 10 kV and the capillary inlet was dipped in methanol for 5 s prior to electrokinetic injection (10 kV, 40 s). The detection wavelength was 235 nm. This method allowed 500 fold enrichment of aconitine alkaloid. A good linear relation was obtained in the range of 31.3-2 x 10(3) microg x L(-1) (r = 0.9996), with the detection limit of 9.4 microg x L(-1). The average recovery was 98.0% with the RSD of 2.6%. The method is simple, rapid and specific with high stacking efficiency; it provides a new reliable means for production and quality control of Guifudihuang pills. | 18,841,765 |
[Experimental research on application of hydrodynamic acoustic generator in extraction of Chinese medicine]. | To study the hydrodynamic ultrasonic energy extraction technique for Chinese Medicine. The content of baicalin in Radix Scutellariae extracts and total flavones in Folium Ginkgo extracts were as indexes respectively and measured by high performance liquid chromatography. We investigated the hydrodynamic ultrasonic energy extraction process for the extraction of Radix Scutellariae and Folium Ginkgo respectively, and compared with refluxing method, decoction and ultrasonic extraction. With the content of the extracts as indexes, Compound prescriptions of Traditional Chinese Medicine were extracted by the hydrodynamic ultrasonic extraction and decoction extraction. The content of baicalin of hydrodynamic ultrasonic energy extracts was significant higher than other extracts. The content of Ginkgo leaves flavones in hydrodynamic ultrasonic energy extracts and ultrasonic extracts had no significant difference. Compared with decocting extracts, hydrodynamic ultrasonic energy extracts of TCM compound prescriptions content was higher greatly. The hydrodynamic ultrasonic energy extraction process showed higher extraction rate of baicalin of radix scutellariae than traditional extraction methods. And it was beneficial to the dissolution of water-soluble constituents in compound prescriptions of TCM. The content of Ginkgo leaves flavones in the hydrodynamic ultrasonic energy extracts and ultrasonic extracts had no obvious difference. | 18,841,766 |
[Effects and mechanism of CD4+ CD25+ regulatory T cells in mouse experimental colitis treated by CLYSTER No. 1]. | To explore the effects and mechanism of CD4+ CD25+ regulatory T cells (Tregs) in mouse experimental colitis treated by CLYSTER No. 1. The mouse model of experimental colitis was established by dinitrochlorobenzene (DNCB)-acetic acid (AA) in mice DNCB and AA. Adult KM mouse were randomly divided into four groups: normal control group, experimental colitis model group, SASP and Chinese medicine therapeutic groups. Proportion of CD4 CD25+ Tregs in peripheral blood (PB) and mesenteric lymph node (MLN) was estimated by flow cytometry at the end of one or two week after treating with SASP and CLYSTER No. 1. The model of experimental colitis in mouse was successfully established. Compared with normal control group, the proportion of CD4 CD25 Tregs was markedly decreased in PB and MLN of model control group of experimental colitis. But it was significantly increased in therapeutic groups of SASP and CLYSTER No. 1, and their CD4+ CD25+ Tregs in PB and MLN were much more than the model control group at the end of one or two weeks after treating with SASP and CLYSTER No. 1. CD4+ CD25+ Tregs with strong immune suppression could play a central role in the initiation and development of mouse experiment colitis, and the CLYSTER No. 1 might exert its therapeutic effects on UC by the regulation of number and function of CD4+ CD25+ Tregs. | 18,841,781 |
[Diagnosis and therapy of choanal polyps from posterior ethmoid sinus]. | To investigate the clinical feature, diagnosis and endoscopic surgery of choanal polyps (CP) from posterior ethmoid sinus. Eleven cases with CP from posterior ethmoid sinus treated by endoscopic endonasal surgery between January 2002 to June 2007 were retrospectively reviewed. Clinical manifestation, intranasal and intrasinus lesions, methods and attentions of endoscopic surgery and therapeutic effects were analysed. All cases were treated by endoscopic surgery and CP were found originated from posterior ethmoidal ostium. Lesions in posterior ethmoid sinus included 3 (27.3%) cyst, 5 (45.4%) polyp and 3 (27.3%) mucosal edema. No operation complications were observed. The follow-up period ranged from 6 months to 3 years (mean 1.2 years) and no recurrence was founded. Most of CP originated from posterior ethmoidal ostium and its formation might be related to the cyst in the sinus. Endoscopic surgery represents a minimally invasive and highly successful procedure, complete removal of CP and lesions in the sinus can reduce the recurrence. | 18,841,792 |
[Diagnosis and management in parotid lymphoepithelioma-like carcinoma]. | To study the diagnosis and treatment of parotid Lymphoepithelioma-like carcinoma (LELC), and improve the rate of the diagnosis and treatment. Eighteen cases with parotid LELC confirmed pathologically were collected in our department, and the clinical presentation, diagnosis, treatment and prognosis were retrospectively summarized and analyzed from 1982 to 2002. All of these LELC patients were found in unilateral side. All cases received Epstein-Barr virus serological test except 2 cases because of refusing, and the testing result displayed: EBV-VCA-IGA positive rate in 93% (15/16); EBV-EA-IGA in 75% (12/ 16); EBV-DNA enzyme in 63% (10/16). Of 16 cases with facial nerve reserved, parotid superficial lobectomy were undertaken in 6 cases, resecting a majority of parotid in 5 cases, whole lobectomy in 5 cases. Facial never resection and whole lobectomy in 2 cases due to facial nerve trunk involved. Functional neck lymph dissection in superior and middle part was undertaken in 14 cases and radical neck lymph dissection in 4 cases, total neck lymph node metastasis rate was 67% (12/18). All of patients received radiotherapy to 50-70 Gy. The follow up were over 1 year, and local recurrence occurred in 2-4 years after operation for 4 cases and had to undergo reoperation. The 1, 3, 5 years survival rates of the 18 cases were 94% (17/18), 72% (13/18) and 50% (9/18), respectively. The chief Causes of death were distant metastasis and local recurrence. There maybe be close relationship between occurrence of LELC and Epstein-Barr virus infection. Its histopathologic feature is similar to undifferentiated nasopharyngeal carcinoma and nasopharynx biopsy must be demanded before confirming diagnosis for eliminating metastasis focus. The neck lymph node metastasis rate of LELC is high and local invasion is strong. It is important to undergo enlarged local resection, neck lymph dissection and postoperative radiotherapy. | 18,841,797 |
[Breast cancer less than 1 cm: bio-morphologic characterization with ER, PgR, Ki67, Her-2/Neu, MDV, MAGS, p53, EGF-R]. | Breast carcinoma is the most common malignant tumour and the main cause of carcinoma death in women. There has been a sharp increase in the detection of breast carcinoma, although mortality is still unvaried. In the last ten years the incidence of breast cancer measuring less than 1 cm, corresponding to pT1a, pT1b in TNM stadiation, has greatly increased. The present study describes the biologic characterisation of small breast carcinomas. The Nottingham/Tenovus Primary Breast Cancer Study stated that tumour size is a significant, independent factor for breast cancer prognosis. Cases were selected among formalin-fixed, paraffin-embedded tissues from 360 ductal breast cancers. In one-half of cases, the tumour was less than 1 cm in diameter, pT1a- pT1b; in the other half the tumour size was greater than 1 cm, but less than 2 cm, pT1c. Histological grading was assessed with the Scarff-Bloom-Richardson method, without Nottingham grade. Immunohistochemical determinations for ER, PgR, Ki-67, Her-2/Neu, CD34, p53, EGFR were done with an automated method. From the above analyses, it was demonstrated that the tumour size is indeed an important prognostic factor, particularly in cases without lymph node metastasis (N0). In particular, we observed significant differences between pT1a-b and pT1c cases, confirming that tumour size is an important criterion for prognostic valuation in ductal breast cancer without lymph node metastasis. | 18,841,818 |
Extragastrointestinal stromal tumor of the urinary wall bladder: case report and review of the literature. | Most mesenchymal tumours of the gastrointestinal tract are now referred to as gastrointestinal stromal tumours (GISTs). These tumours typically express c-kit (CD117) and CD34; 30-50% are (often focally) positive for alpha-smooth muscle actin, and all are negative for desmin and S100 protein. Recently, mutations in exon 11 of the c-kit gene have been identified as a molecular genetic marker for the subset of GISTs. In this report, we describe a mesenchymal tumour removed from the pelvic cavity of a 34-year-old man. The tumour was strongly attached to the external wall of the urinary bladder. The neoplasm grossly resembled a leiomyoma, and was histologically composed of sheets of spindle cells with a dense collagenous background. The mitotic activity was low (less then 1 per 50 high-power fields). Immunohistochemically, tumour cells were negative for alpha-smooth muscle actin and desmin and positive for CD117 and CD34. This case illustrates that tumours which are phenotypically and genotypically similar to GISTs may present in sites other than the tubular gastrointestinal tract. | 18,841,822 |
A pulmonary mucinous cystic tumour of borderline malignancy. | We report a well-documented case of pulmonary mucinous cystic tumour of borderline malignancy involving the left lower lobe. The lesion was found incidentally by chest radiograph and CT scan with a provisional diagnosis of bronchioloalveolar carcinoma. The tumour was 4 cm in its greatest dimension, cystic and filled with gelatinous mucus. Microscopically, the neoplastic mucinous epithelium was composed of cuboidal cells with focally nuclear stratification and mild to moderate nuclear atypia. The patient has remained free from recurrence or metastases for 6 years. Pulmonary mucinous cystic tumour of borderline malignancy is a rare, recently described neoplasm, which spans a spectrum of tumours with malignant potential. The recent World Health Organization classification of lung tumours does not recognize this entity, which has a very good prognosis, and as such should be distinguished from classic pulmonary adenocarcinoma. Histological diagnosis can be difficult to distinguish from cystic bronchioloalveolar carcinoma or metastatic mucinous adenocarcinoma. | 18,841,826 |
Real-time tumor tracking with preprogrammed dynamic multileaf-collimator motion and adaptive dose-rate regulation. | The authors have developed a new method for real-time tumor tracking with dynamic multileaf-collimator (MLC) motion under condition of free breathing. Unlike other previously proposed tumor-tracking methods, their new method uses a preprogrammed dynamic MLC sequence in combination with real-time dose-rate control. This new scheme circumvents the technical challenge in MLC-based tumor tracking of having to control the MLC motion in real time, based on real-time detected tumor motion. With their new method, the movement of the tumor, as a function of breathing phase, amplitude, or tidal volume, is reflected in the preprogrammed MLC sequence. The irregularity of breathing during treatment is handled by real-time regulation of the machine dose rate, which effectively speeds up or slows down the delivery of radiation as needed. This method is based on the fact that all of the parameters in dynamic radiation delivery, including MLC motion, are enslaved to the cumulative dose, which, in turn, can be accelerated or decelerated by varying the dose rate. Because commercially available MLC systems do not allow the MLC delivery sequence to be modified in real time based on the patient's breathing signal, previously proposed tumor-tracking techniques using a MLC cannot be readily implemented in the clinic today. By using a preprogrammed MLC sequence to handle the required motion, the task for real-time control is greatly simplified. With their new scheme, which they call dose-rate-regulated tracking (DRRT), it is possible to use existing linear accelerators that have dynamic MLC capability to achieve real-time tumor tracking, provided that the beam dose rate can be controlled externally. Tracking-error evaluation for 13 patients out of 14 resulted in a tracking error of less than 1 mm (1 sigma), if the effect of the response time of the treatment machine on the dose-rate modulation can be neglected. Film measurements on a moving phantom with variable breathing patterns and DRRT delivery showed that 97% of the measurement points have gamma values less than 1 (for 3% and 2-mm criteria), while non-DRRT delivery showed only 87%. This study shows that real-time tracking is feasible with DRRT even when the patient breathing frequency is irregular. Effects of the variation of breathing amplitude and of base line drift on the tracking error with DRRT are discussed; pending further study, a criterion is suggested for patient selection in the application of this new technique in the clinic. | 18,841,846 |
Comparison of SNR and CNR for in vivo mouse brain imaging at 3 and 7 T using well matched scanner configurations. | Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) for magnetic resonance microimaging were measured using two nearly identical magnetic resonance imaging (MRI) scanners operating at field strengths of 3 and 7 T. Six mice were scanned using two imaging protocols commonly applied for in vivo imaging of small animal brain: RARE and FLASH. An accounting was made of the field dependence of relaxation times as well as a small number of hardware disparities between scanner systems. Standard methods for relaxometry were utilized to measure T1 and T2 for two white matter (WM) and two gray matter (GM) regions in the mouse brain. An average increase in T1 between 3 and 7 T of 28% was observed in the brain. T2 was found to decrease by 27% at 7 T in agreement with theoretical models. The SNR was found to be uniform throughout the mouse brain, increasing at higher field by a factor statistically indistinguishable from the ratio of Larmor frequencies when imaging with either method. The CNR between GM and WM structures was found to adhere to the expected field dependence for the RARE imaging sequence. Improvement in the CNR for the FLASH imaging sequence between 3 and 7 T was observed to be greater than the Larmor ratio, reflecting a greater susceptibility to partial volume effects at the lower SNR values at 3 T. Imaging at 7 T versus 3 T in small animals clearly provides advantages with respect to the CNR, even beyond the Larmor ratio, especially in lower SNR regimes. This careful multifaceted assessment of the benefits of higher static field is instructive for those newly embarking on small animal imaging. Currently the number of 7 T MRI scanners in use for research in human subjects is increasing at a rapid pace with approximately 30 systems deployed worldwide in 2008. The data presented in this article verify that if system performance and radio frequency uniformity is optimized at 7 T, it should be possible to realize the expected improvements in the CNR and SNR compared with MRI at 3 T. | 18,841,848 |
Monte Carlo calculations of correction factors for plane-parallel ionization chambers in clinical electron dosimetry. | Recent standard dosimetry protocols recommend that plane-parallel ionization chambers be used in the measurements of depth-dose distributions or the calibration of low-energy electron beams with beam quality R50 <4 g/cm2. In electron dosimetry protocols with the plane-parallel chambers, the wall correction factor, Pwall, in water is assumed to be unity and the replacement correction factor, Prepl, is taken to be unity for well-guarded plane-parallel chambers, at all measurement depths. This study calculated Pwall and Prepl for NACP-02, Markus, and Roos plane-parallel chambers in clinical electron dosimetry using the EGSnrc Monte Carlo code system. The Pwall values for the plane-parallel chambers increased rapidly as a function of depth in water, especially at lower energy. The value around R50 for NACP-02 was about 10% greater than unity at 4 MeV. The effect was smaller for higher electron energies. Similarly, Prepl values with depth increased drastically at the region with the steep dose gradient for lower energy. For Markus Prepl departed more than 10% from unity close to R50 due to the narrow guard ring width. Prepl for NACP-02 and Roos was close to unity in the plateau region of depth-dose curves that includes a reference depth, dref. It was also found that the ratio of the dose to water and the dose to the sensitive volume in the air cavity for the plane-parallel chambers, Dw/[Dair]pp, at d(ref) differs significantly from that assumed by electron dosimetry protocols. | 18,841,855 |
Geometrical differences in target volumes between slow CT and 4D CT imaging in stereotactic body radiotherapy for lung tumors in the upper and middle lobe. | Since stereotactic body radiotherapy (SBRT) was started for patients with lung tumor in 1998 in our institution, x-ray fluoroscopic examination and slow computed tomography (CT) scan with a rotation time of 4 s have been routinely applied to determine target volumes. When lung tumor motion observed with x-ray fluoroscopy is larger than 8 mm, diaphragm control (DC) is used to reduce tumor motion during respiration. After the installation of a four-dimensional (4D) CT scanner in 2006, 4D CT images have been supplementarily acquired to determine target volumes. It was found that target volumes based on slow CT images were substantially different from those on 4D CT images, even for patients with lung tumor motion no larger than 8 mm. Although slow CT scan might be expected to fare well for lung tumors with motion range of 8 mm or less, the potential limitations of slow CT scan are unknown. The purpose of this study was to evaluate the geometrical differences in target volumes between slow CT and 4D CT imaging for lung tumors with motion range no larger than 8 mm in the upper and middle lobe. Of the patients who underwent SBR between October 2006 and April 2008, 32 patients who had lung tumor with motion range no larger than 8 mm and did not need to use DC were enrolled in this study. Slow CT and 4D CT images were acquired under free breathing for each patient. Target volumes were manually delineated on slow CT images (TV(slow CT)). Gross tumor volumes were also delineated on each of the 4D CT volumes and their union (TV(4D CT)) was constructed. Volumetric and statistical analyses were performed for each patient. The mean +/- standard deviation (S.D.) of TV(slow CT)/TV(4D CT) was 0.75 +/- 0.17 (range, 0.38-1.10). The difference between sizes of TV(slow CT) and TV(4D CT) was not statistically significant (P = 0.096). A mean of 8% volume of TV(slow CT) was not encompassed in TV(4D CT) (mean +/- S.D. = 0.92 +/- 0.07). The patients were separated into two groups to test whether the quality of target delineation on slow CT scans depends on respiratory periods below or above the CT rotation time of 4 s. No significant difference was observed between these groups (P = 0.229). Even lung tumors with motion range no larger than 8 mm might not be accurately depicted on slow CT images. When only a single slow CT scan was used for lung tumors with motion range of 8 mm or less, 95% confidence values for additional margins for TV(slow CT) to encompass TV(4D CT) were 4.0, 5.4, 4.9, 5.1, 1.8, and 1.7 mm for lateral, medial, ventral, dorsal, cranial, and caudal directions, respectively. | 18,841,867 |
Proteomic analysis of the hyaloid vascular system regression during ocular development. | We describe a proteomic approach to investigate the differential protein expression patterns and identify the physiologically relevant angiogenic and antiangiogenic factors involved in the hyaloid vascular system regression. Differentially expressed proteins were identified using two-dimensional gel electrophoresis followed by nanoflow chromatography coupled with tandem mass spectrometry. These proteins are expected to provide insight as to their function in the early maintenance and eventual regression of the hyaloid vascular system. | 18,841,878 |
Synthesis and evaluation of structurally constrained quinazolinone derivatives as potent and selective histamine H3 receptor inverse agonists. | A series of structurally constrained derivatives of the potent H 3 inverse agonist 1 was designed, synthesized, and evaluated as histamine H 3 receptor inverse agonists. As a result, the N-cyclobutylpiperidin-4-yloxy group as in 2f was identified as an optimal surrogate structure for the flexible 1-pyrrolidinopropoxy group of 1. Subsequent optimization of the quinazolinone core of 2f revealed that substitution at the 5-position of the quinazolinone ring influences potency. Representative derivatives 5a and 5s showed improved potency in a histamine release assay in rats and a receptor occupancy assay in mice. | 18,841,880 |
Highly diastereoselective switchable enantioselective Mannich reaction of glycine derivatives with imines. | Tuning of diastereoselectivity was realized in the Mannich reaction of glycine derivatives with aromatic and aliphatic N-Ts imines using CuClO4-FcPHOX ligand 4b and 4f having an MeO group at the 4-position and F atom at the 3,5-position of the phenyl ring on the P-atom respectively as catalyst, providing either anti- or syn-alpha,beta-diamino acid derivatives in high yields and in high diastereo- and enantioselectivities. | 18,841,892 |
Self-assembly of organic-inorganic hybrid amphiphilic surfactants with large polyoxometalates as polar head groups. | Mn-Anderson-C6 and Mn-Anderson-C16, A type of inorganic-organic hybrid molecules containing a large anionic polyoxometalate (POM) cluster and two C6 and C16 alkyl chains, respectively, demonstrate amphiphilic surfactant behavior in the mixed solvents of acetonitrile and water. The amphiphilic hybrid molecules can slowly assemble into membrane-like vesicles by using the POM clusters as polar head groups, as studied by laser light scattering and TEM techniques. The hollow vesicles have a typical bilayer structure with the hydrophilic Mn-Anderson cluster facing outside and long hydrophobic alkyl chains staying inside to form the solvent-phobic layer. Due to the rigidity of the POM polar heads, the two alkyl tails have to bend significantly for the vesicle formation, which makes the vesicle formation more difficult compared to some conventional surfactants. This is the first example of using hydrophilic POM macroions as polar head groups for a surfactant system. | 18,841,899 |
Triterpene glycosides from Antarctic sea cucumbers. 1. Structure of liouvillosides A1, A2, A3, B1, and B2 from the sea cucumber Staurocucumis liouvillei: new procedure for separation of highly polar glycoside fractions and taxonomic revision. | Five new triterpene glycosides, liouvillosides A1 (1), A2 (2), A3 (3), B1 (4), and B2 (5), have been isolated from the Antarctic sea cucumber Staurocucumis liouviellei along with the known liouvilloside A(6), isolated earlier from the same species, and hemoiedemosides A (7) and B (8), isolated earlier from the Patagonian sea cucumber Hemioedema spectabilis. The isolation was carried out using a new chromatographic procedure including application of ion-pair reversed-phase chromatography followed by chiral chromatography on a cyclodextrin ChiraDex column. The structures of the new glycosides were elucidated using extensive NMR spectroscopy (1H and 13C NMR spectrometry, DEPT, 1H-(1)H COSY, HMBC, HMQC, and NOESY), ESI-FTMS, and CID MS/MS, and chemical transformations. Glycosides 1-3 are disulfated tetraosides and glycosides 4 and 5 are trisulfated tetraosides. Glycosides 2 and 3 contain 3-O-methylquinovose, found for the first time as a natural monosaccharide in sea cucumber glycosides. On the basis of analyses of glycoside structures a taxonomic revision is proposed. | 18,841,904 |
Aza-beta3-cyclotetrapeptides. | The cyclization of aza-beta(3)-tetrapeptides gives access to new CTP (cyclotetrapeptide) analogues. These stereocontrolled templates are assembled without any asymmetric synthesis. X-ray crystallographic structure and NMR analysis show that the macrocyclic scaffold is characterized by a fully cooperative intramolecular H-bond network, in sharp contrast with the nanotubular assemblies observed for beta(3)-cyclotetrapeptides. This folding property reduces considerably the polarity of aza-beta(3)-tetrapeptides and should be useful in addressing intracellular targets. | 18,841,910 |
Interactions between antimicrobial polynorbornenes and phospholipid vesicles monitored by light scattering and microcalorimetry. | Antimicrobial polynorbornenes composed of facially amphiphilic monomers have been previously reported to accurately emulate the antimicrobial activity of natural host-defense peptides (HDPs). The lethal mechanism of most HDPs involves binding to the membrane surface of bacteria leading to compromised phospholipid bilayers. In this paper, the interactions between biomimetic vesicle membranes and these cationic antimicrobial polynorbornenes are reported. Vesicle dye-leakage experiments were consistent with previous biological assays and corroborated a mode of action involving membrane disruption. Dynamic light scattering (DLS) showed that these antimicrobial polymers cause extensive aggregation of vesicles without complete bilayer disintegration as observed with surfactants that efficiently solubilize the membrane. Fluorescence microscopy on vesicles and bacterial cells also showed polymer-induced aggregation of both synthetic vesicles and bacterial cells. Isothermal titration calorimetry (ITC) afforded free energy of binding values (Delta G) and polymer to lipid binding ratios, plus revealed that the interaction is entropically favorable (Delta S>0, Delta H>0). It was observed that the strength of vesicle binding was similar between the active polymers while the binding stoichiometries were dramatically different. | 18,841,926 |
High nuclearity single-molecule magnets: a mixed-valence Mn26 cluster containing the di-2-pyridylketone diolate dianion. | The employment of the dianion (dpkd(2-)) of the gem-diol form of di-2-pyridylketone (dpk) as a tetradentate chelate in manganese chemistry is reported, and the synthesis, crystal structure, and magnetochemical characterization of [Mn26O16(OMe)12(dpkd)12(MeOH)6](OH)6 x solv (3 x solv) are described. The reaction of Mn(ClO4)2 x 6 H2O, dpk, NaOMe, and NEt3 (2:1:4:2) in MeCN/MeOH affords complex 3, which possesses a rare metal topology and is mixed-valence (4 Mn(II), 22 Mn(III)). The complicated [Mn26(mu4-O)10(mu3-O)6(mu3-OMe)12(mu-OR)12](18+) core of 3 consists of an internal Mn(III)16 cage of adjacent Mn4 tetrahedra surrounded by an external Mn(II)4Mn(III)6 shell. The latter is held together by the alkoxide arms of twelve eta(1):eta(2):eta(1):eta(1):mu3 dpkd(2-) groups. Variable-temperature, solid-state direct current (dc), and alternating current (ac) magnetization studies were carried out on 3 in the 1.8-300 K range. Complex 3 is predominantly antiferromagnetically coupled with a resulting S = 6 ground state, a conclusion confirmed by the in-phase (chi'(M)) ac susceptibility data. The observation of out-of-phase (chi''(M)) ac susceptibility signals suggested that 3 might be a single-molecule magnet, and this was confirmed by single-crystal magnetization vs dc field sweeps that exhibited hysteresis, the diagnostic property of a magnet. Combined ac chi''(M) and magnetization decay vs time data collected below 1.1 K were used to construct an Arrhenius plot; the fit of the thermally activated region above approximately 0.1 K gave U(eff) = 30 K, where U(eff) is the effective relaxation barrier. At lower temperatures, the complex exhibits temperature-independent relaxation, characteristic of ground-state quantum tunneling of magnetization between the lowest-lying M(s) = +/-6 levels. The combined work demonstrates the ligating flexibility of dipyridyl-diolate chelates and their usefulness in the synthesis of polynuclear Mn(x) clusters with interesting magnetic properties, without requiring the co-presence of carboxylate ligands. | 18,841,928 |
Ab initio study of the diatomic fluorides FeF, CoF, NiF, and CuF. | The late-3d transition-metal diatomic fluorides MF = FeF, CoF, NiF, and CuF have been studied using variational multireference (MRCI) and coupled-cluster [RCCSD(T)] methods, combined with large to very large basis sets. We examined a total of 35 (2S+1)|Lambda| states, constructing as well 29 full potential energy curves through the MRCI method. All examined states are ionic, diabatically correlating to M(+)+F(-)((1)S). Notwithstanding the "eccentric" character of the 3d transition metals and the difficulties to accurately be described with all-electron ab initio methods, our results are, in general, in very good agreement with available experimental numbers. | 18,841,949 |
Spiroacetal biosynthesis in insects from Diptera to Hymenoptera: the Giant Ichneumon wasp Megarhyssa nortoni nortoni Cresson. | The volatile components of the mandibular gland secretion generated by the Giant Ichneumon parasitoid wasp Megarhyssa nortoni nortoni Cresson are mainly spiroacetals and methyl ketones, and all have an odd number of carbon atoms. A biosynthetic scheme rationalizing the formation of these diverse components is presented. This scheme is based on the results of incorporation studies using (2)H-labeled precursors and [(18)O]dioxygen. The key steps are postulated to be decarboxylation of beta-ketoacid equivalents, beta-oxidation (chain shortening), and monooxygenase-mediated hydroxylation leading to a putative ketodiol that cyclizes to spiroacetals. The generality of the role of monooxygenases in spiroacetal formation in insects is considered, and overall, a cohesive, internally consistent theory of spiroacetal generation by insects is presented, against which future hypotheses will have to be compared. | 18,841,963 |
Formation of spectral intermediate G-C and A-T anion complex in duplex DNA studied by pulse radiolysis. | The dynamics of electron adducts of 2'-deoxynucleotides and oligonucelotides (ODNs) were measured spectroscopically by nanosecond pulse radiolysis. The radical anions of the nucleotides were produced within 10 ns by the reaction of hydrated electrons (e(aq)(-)) and were protonated to form the corresponding neutral radicals. At pH 7.0, the radical anion of deoxythymidine (dT(*-)) was protonated to form the neutral radical dT(H)(*) in the time range of microseconds. The rate constant for the protonation was determined as 1.8 x 10(10) M(-1) s(-1). In contrast, the neutral radical of dC(H)(*) was formed immediately after the pulse, suggesting that the protonation occurs within 10 ns. The transient spectra of excess electrons of the double-stranded ODNs 5'-TAATTTAATAT-3' (AT) and 5'-CGGCCCGGCGC-3' (GC) differed from those of pyrimidine radicals (C and T) and their composite. In contrast, the spectra of the electron adducts of the single-stranded ODNs GC and AT exhibited characteristics of C and T, respectively. These results suggest that, in duplex ODNs, the spectral intermediates of G-C and A-T anions complex were formed. On the microsecond time scale, the subsequent changes in absorbance of the ODN AT had a first-order rate constant of 4 x 10(4) s(-1), reflecting the protonation of T. | 18,841,971 |
Inhibition of Angiotensin converting enzyme I caused by autolysis of potato proteins by enzymatic activities confined to different parts of the potato tuber. | Autolysis of protein isolates from vascular bundle and inner tuber tissues of potato (Solanum tuberosum) enhanced the inhibition of the angiotensin converting enzyme I (ACE), a biochemical factor affecting blood pressure (hypertension). The physiological age of the tuber affected the strength of ACE inhibition, the rate of its increase during autolysis, and the tuber tissue where ACE inhibition was most pronounced. The highest inhibitory activities (50% reduction in ACE activity achieved following autolysis at a protein concentration of 0.36 mg mL (-1)) were measured in tubers after 5-6 months of storage prior to sprouting. The rate of ACE inhibition was positively correlated with protease activity in tuber tissues. Amendment of the autolysis reaction with protein substrates from which bioactive ACE-inhibitory peptides may be released, for example, a purified recombinant protein or a concentrate of total tuber proteins, also enhanced ACE inhibition. Many tuber proteins including aspartic protease inhibitors were degraded during autolysis. The data provide indications of differences in the enzymatic activities confined to different parts of the potato tuber at different physiological stages. Results suggest that native enzymes and substrate proteins of potato tubers can be utilized in search of dietary tools to manage elevated blood pressure. | 18,841,984 |
Logistic regression modeling of cropping systems to predict fumonisin contamination in maize. | The aims of this research were to monitor the presence of fumonisins in maize crops in northern Italy over a 6 year period, to study the role of the cropping system on fumonisin levels, and to contribute to the development of a predictive system for fumonisin contamination. In the 6 year period from 2002 to 2007, 438 maize samples were collected in five regions, supported by agronomic data, and analyzed for fumonisin content. Fumonisin was detected in almost all of the grain samples, but 2007 was less and 2005 more contaminated compared to the other years. Preceding crop, maturity class of hybrids, nitrogen fertilization, sowing and harvest week, and grain moisture significantly affected the level of contamination. The logistic regression developed explained around 60% of variability with major roles for longitude, maturity class, and growing weeks. The function can be used to quantify the effect of these factors in a predictive system. | 18,841,987 |
Electrochemically modulated liquid-liquid extraction of ionized drugs under physiological conditions. | Electrochemically modulated liquid-liquid extraction (EMLLE) enables the selective extraction and separation of ions from mixtures by choice of an applied interfacial potential difference. The extraction of ionized drugs from artificial urine is reported in this paper. The artificial urine matrix was characterized by cyclic voltammetry at the interface between two immiscible electrolyte solutions (ITIES), showing that components of that aqueous phase truncate the available potential window at the ITIES. The transfer of three cationic drugs from aqueous artificial urine to the 1,2-dichloroethane organic electrolyte phase was examined. Both propranolol and timolol were found to transfer across the artificial urine-organic interface. However, sotalol transfer was not possible within the available potential window. Extraction of propranolol and timolol from artificial urine into an organogel phase, by electrochemically modulated liquid-liquid extraction, was examined. The application of potentials positive of the drugs' formal transfer potentials enabled the selective extraction of both propranolol and timolol, with a higher potential being required for timolol. This work demonstrates the practical utility of EMLLE for the selective extraction of target compounds from a complex sample matrix. | 18,841,995 |
O-phospho-L-serine and the thiocarboxylated sulfur carrier protein CysO-COSH are substrates for CysM, a cysteine synthase from Mycobacterium tuberculosis. | The kinetic pathway of CysM, a cysteine synthase from Mycobacterium tuberculosis, was studied by transient-state kinetic techniques. The expression of which is upregulated under conditions of oxidative stress. This enzyme exhibits extensive homology with the B-isozymes of the well-studied O-acetylserine sulfhydrylase family and employs a similar chemical mechanism involving a stable alpha-aminoacrylate intermediate. However, we show that specificity of CysM for its amino acid substrate is more than 500-fold greater for O-phospho-L-serine than for O-acetyl-L-serine, suggesting that O-phospho-L-serine is the likely substrate in vivo. We also investigated the kinetics of the carbon-sulfur bond-forming reaction between the CysM-bound alpha-aminoacrylate intermediate and the thiocarboxylated sulfur carrier protein, CysO-COSH. The specificity of CysM for this physiological sulfide equivalent is more than 3 orders of magnitude greater than that for bisulfide. Moreover, the kinetics of this latter reaction are limited by association of the proteins, while the reaction with bisulfide is consistent with a rapid equilibrium binding model. We interpret this finding to suggest that the CysM active site with the bound aminoacrylate intermediate is protected from solvent and that binding of CysO-COSH produces a conformational change allowing rapid sulfur transfer. This study represents the first detailed kinetic characterization of sulfide transfer from a sulfide carrier protein. | 18,842,002 |
P450 versus P420: correlation between cyclic voltammetry and visible absorption spectroscopy of the immobilized heme domain of cytochrome P450 BM3. | Cyclic voltabsorptometry is used for the first time to distinguish and characterize electrochemically the active (P450) and inactive (P420) forms of cytochromes P450 immobilized on an electrode during voltammetry experiments. This was achieved by using the heme domain (BMP) of the bacterial cytochrome P450 BM3 from Bacillus megaterium (CYP102A1) immobilized on mesopouros tin-oxide (SnO2) electrodes. We demonstrate that the formation of either the P450 form or the P420 one can be obtained by modifying the mesoporous electrode surface with polycations with different properties such as polyethylenimmine (PEI) and polydiallyldimethylammonium chloride (PDDA). Potential step spectroelectrochemistry allowed measurement of reduction potentials of the active P450 form. Values of -0.39+/-0.01 V and -0.58+/-0.01 V (both versus Ag/AgCl) were calculated for the active P450 form immobilized on the BMP/PDDA-SnO2 and BMP/PEI-SnO2 electrodes, respectively. The cyclic voltabsorptometric experiments showed how, when both the active and inactive forms are present on the PEI film, the inactive P420 species tends to dominate the cyclic voltammetric signal. | 18,842,012 |
Synthesis of 1,1-dialkylindolium-2-thiolates via base-induced transformation of 4-(2-chloro-5-nitrophenyl)-1,2,3-thiadiazole in the presence of secondary amines. | 4-(2-Chloro-5-nitrophenyl)-1,2,3-thiadiazole undergoes ring-opening to produce a thioketene intermediate that reacts with secondary amines forming 2-(2-chloro-5-nitrophenyl)-N,N-dialkylthioacetamides. Intramolecular cyclization of these thioamides via nucleophilic substitution of the halogen on the aromatic ring affords nonaromatic 1,1-dialkylindolium-2-thiolates instead of the expected aromatic N,N-dialkylaminobenzo[b]thiophenes. | 18,842,029 |
The promiscuity of beta-strand pairing allows for rational design of beta-sheet face inversion. | Recent studies suggest the dominant role of main-chain H-bond formation in specifying beta-sheet topology. Its essentially sequence-independent nature implies a large degree of freedom in designing beta-sheet-based nanomaterials. Here we show rational design of beta-sheet face inversions by incremental deletions of beta-strands from the single-layer beta-sheet of Borrelia outer surface protein A. We show that a beta-sheet structure can be maintained when a large number of native contacts are removed and that one can design large-scale conformational transitions of a beta-sheet such as face inversion by exploiting the promiscuity of strand-strand interactions. High-resolution X-ray crystal structures confirmed the success of the design and supported the importance of main-chain H-bonds in determining beta-sheet topology. This work suggests a simple but effective strategy for designing and controlling nanomaterials based on beta-rich peptide self-assemblies. | 18,842,042 |
Direct visualization of reversible switching of micropatterned polyelectrolyte brushes on gold surfaces using laser scanning confocal microscopy. | We apply confocal fluorescence microscopy for real time studies of reversible conformational changes of poly(methacryloyloxyethyl phosphate) (PMEP) brushes chemically grafted onto gold substrates. Oregon green 488 fluorophores chemically attached onto the PMEP polymers were used as reporters for probing the conformational changes. Use of a specially designed liquid flow microchamber allowed dynamic imaging of the brushes under varying environmental conditions. The fluorescence intensities exhibited fully reversible brightness changes on alternation of the solution in the chamber between water and KCl. This reversible quenching behavior is consistent with a conformational change between an extended and a collapsed brush configuration. The fluorescence quenching behavior of the brushes was found to be dependent on ion concentration as well as polymer grafting density and was caused by nonradiative energy transfer to the polymer scaffold and the gold substrate. | 18,842,063 |
Impact of model perfumes on surfactant and mixed surfactant self-assembly. | The impact of some model perfumes on surfactant self-assembly has been investigated, using small-angle neutron scattering. A range of different model perfumes, with differing degrees of hydrophilicity/hydrophobicity, have been explored, and in order of increasing hydrophobicity include phenyl ethanol (PE), rose oxide (RO), limonene (LM), linalool (LL), and dihydrogen mercenol (DHM). The effect of their solubilization on the nonionic surfactant micelles of dodecaethylene monododecyl ether (C12EO12) and on the mixed surfactant aggregates of C12EO12 and the cationic dialkyl chain surfactant dihexadecyl dimethyl ammonium bromide (DHDAB) has been quantified. For PE and LL the effect of their solubilization on the micelle, mixed micelle/lamellar and lamellar regimes of the C12EO12/DHDAB mixtures, has also been determined. For the C12EO12 and mixed DHDAB/C12EO12 micelles PE is solubilized predominantly at the hydrophilic/hydrophobic interface, whereas the more hydrophobic perfumes, from RO to DHM, are solubilized predominantly in the hydrophobic core of the micelles. For the C12EO12 micelles, with increasing perfume concentration, the more hydrophobic perfumes (RO to DHM) promote micellar growth. Relatively modest growth is observed for RO and LM, whereas substantial growth is observed for LL and DHM. In contrast, for the addition of PE the C12EO12 micelles remain as relatively small globular micelles, with no significant growth. For the C12EO12/DHDAB mixed micelles, the pattern of behavior with the addition of perfume is broadly similar, except that the micellar growth with increasing perfume concentration for the more hydrophobic perfumes is less pronounced. In the Lbeta (Lv) region of the DHDAB-rich C12EO12/DHDAB phase diagram, the addition of PE results in a less structured (less rigid) lamellar phase, and ultimately a shift toward a structure more consistent with a sponge or bicontinuous phase. In the mixed L1/Lbeta region of the phase diagram PE induces a slight shift in the coexistence from Lbeta toward L1. The addition of LL to the Lbeta (Lv) region of the DHDAB-rich C12EO12/DHDAB phase diagram also results in a reduction in the lamellar structure (less rigid lamellae), and a shift toward a structure more consistent with a sponge or bicontinuous phase, or a coexisting phase of small vesicles. For the mixed L1/Lbeta region of the phase diagram LL induces a shift toward a greater L beta component. | 18,842,064 |
Adaptive strategies for reading with a forced retinal location. | Forcing normal-sighted participants to use a distinct parafoveal retinal location for reading, we studied which part of the visual field is best suited to take over functions of the fovea during early stages of macular degeneration (MD). A region to the right of fixation lead to best reading performance and most natural gaze behavior, whereas reading performance was severely impaired when a region to the left or below fixation had to be used. An analysis of the underlying oculomotor behavior revealed that practice effects were accompanied by a larger number of saccades in text direction and decreased fixation durations, whereas no adjustment of saccade amplitudes was observed. We provide an explanation for the observed performance differences at different retinal locations based on the interplay of attention and eye movements. Our findings have important implications for the development of training methods for MD patients targeted at reading, suggesting that it would be beneficial for MD patients to use a region to the right of their central scotoma. | 18,842,077 |
Perceptual multistability predicted by search model for Bayesian decisions. | Perceptual multistability refers to the phenomenon of spontaneous perceptual switching between two or more likely interpretations of an image. Although frequently explained by processes of adaptation or hysteresis, we show that perceptual switching can arise as a natural byproduct of perceptual decision making based on probabilistic (Bayesian) inference, which interprets images by combining probabilistic models of image formation with knowledge of scene regularities. Empirically, we investigated the effect of introducing scene regularities on Necker cube bistability by flanking the Necker cube with fields of unambiguous cubes that are oriented to coincide with one of the Necker cube percepts. We show that background cubes increase the time spent in percepts most similar to the background. To characterize changes in the temporal dynamics of the perceptual alternations beyond percept durations, we introduce Markov Renewal Processes (MRPs). MRPs provide a general mathematical framework for describing probabilistic switching behavior in finite state processes. Additionally, we introduce a simple theoretical model consistent with Bayesian models of vision that involves searching for good interpretations of an image by sampling a posterior distribution coupled with a decay process that favors recent to old interpretations. The model has the same quantitative characteristics as our human data and variation in model parameters can capture between-subject variation. Because the model produces the same kind of stochastic process found in human perceptual behavior, we conclude that multistability may represent an unavoidable by-product of normal perceptual (Bayesian) decision making with ambiguous images. | 18,842,083 |
Detection of skewed symmetry. | This study examined the ability of human observers to discriminate between symmetric and asymmetric planar figures from perspective and orthographic images. The first experiment showed that the discrimination is reliable in the case of polygons, but not dotted patterns. The second experiment showed that the discrimination is facilitated when the projected symmetry axis or projected symmetry lines are known to the subject. A control experiment showed that the discrimination is more reliable with orthographic, than with perspective images. Based on these results, we formulated a computational model of symmetry detection. The model measures the asymmetry of the presented polygon based on its single orthographic or perspective image. Performance of the model is similar to that of the subjects. | 18,842,085 |
Sinorhizobium meliloti regulator MucR couples exopolysaccharide synthesis and motility. | In order to enter symbiosis with its legume partner, Sinorhizobium meliloti requires regulatory systems for the appropriate responses to its environment. For example, motility is required for the chemotactic movement of bacteria toward the compounds released by its host, and exopolysaccharides (EPS) are required for bacterial attachment to the root or for invasion of the infection thread. Previous research has shown that ExoR/ExoS/ChvI as well as the ExpR/Sin quorum-sensing system inversely regulate both motility and EPS production, although the regulation mechanisms were unknown. We were able to attribute the ExpR-mediated regulation of motility to the ability of ExpR to bind a DNA sequence upstream of visN when activated by N-acyl-homoserine lactone. Furthermore, MucR, previously characterized as a regulator of EPS production, also affected motility. MucR inhibited expression of rem encoding an activator of motility gene expression and, consequently, the expression of Rem-regulated genes such as flaF and flgG. Binding of MucR to the rem promoter region was demonstrated and a sequence motif similar to the previously identified MucR binding consensus was identified within this region. The swarming ability of S. meliloti Rm2011 was shown to depend on a functional ExpR/Sin quorum-sensing system and the production of both flagella and EPS. Finally, we propose a model for the coordination of motility and EPS synthesis in S. meliloti. | 18,842,098 |
Drosophila models of neurodegenerative diseases. | Neurodegenerative diseases are progressive disorders of the nervous system that affect specific cellular populations in the central and peripheral nervous systems. Although most cases are sporadic, genes associated with familial cases have been identified, thus enabling the development of animal models. Invertebrates such as Drosophila have recently emerged as model systems for studying mechanisms of neurodegeneration in several major neurodegenerative diseases. These models are also excellent in vivo systems for the testing of therapeutic compounds. Genetic studies using these animal models have provided novel insights into the disease process. We anticipate that further exploration of the animal models will further our understanding of mechanisms of neurodegeneration as well as facilitate the development of rational treatments for debilitating degenerative diseases. | 18,842,101 |
LC-MSsim--a simulation software for liquid chromatography mass spectrometry data. | Mass Spectrometry coupled to Liquid Chromatography (LC-MS) is commonly used to analyze the protein content of biological samples in large scale studies. The data resulting from an LC-MS experiment is huge, highly complex and noisy. Accordingly, it has sparked new developments in Bioinformatics, especially in the fields of algorithm development, statistics and software engineering. In a quantitative label-free mass spectrometry experiment, crucial steps are the detection of peptide features in the mass spectra and the alignment of samples by correcting for shifts in retention time. At the moment, it is difficult to compare the plethora of algorithms for these tasks. So far, curated benchmark data exists only for peptide identification algorithms but no data that represents a ground truth for the evaluation of feature detection, alignment and filtering algorithms. We present LC-MSsim, a simulation software for LC-ESI-MS experiments. It simulates ESI spectra on the MS level. It reads a list of proteins from a FASTA file and digests the protein mixture using a user-defined enzyme. The software creates an LC-MS data set using a predictor for the retention time of the peptides and a model for peak shapes and elution profiles of the mass spectral peaks. Our software also offers the possibility to add contaminants, to change the background noise level and includes a model for the detectability of peptides in mass spectra. After the simulation, LC-MSsim writes the simulated data to mzData, a public XML format. The software also stores the positions (monoisotopic m/z and retention time) and ion counts of the simulated ions in separate files. LC-MSsim generates simulated LC-MS data sets and incorporates models for peak shapes and contaminations. Algorithm developers can match the results of feature detection and alignment algorithms against the simulated ion lists and meaningful error rates can be computed. We anticipate that LC-MSsim will be useful to the wider community to perform benchmark studies and comparisons between computational tools. | 18,842,122 |
Variations in the transcriptome of Alzheimer's disease reveal molecular networks involved in cardiovascular diseases. | Because of its polygenic nature, Alzheimer's disease is believed to be caused not by defects in single genes, but rather by variations in a large number of genes and their complex interactions. A systems biology approach, such as the generation of a network of co-expressed genes and the identification of functional modules and cis-regulatory elements, to extract insights and knowledge from microarray data will lead to a better understanding of complex diseases such as Alzheimer's disease. In this study, we perform a series of analyses using co-expression networks, cis-regulatory elements, and functions of co-expressed gene modules to analyze single-cell gene expression data from normal and Alzheimer's disease-affected subjects. We identified six co-expressed gene modules, each of which represented a biological process perturbed in Alzheimer's disease. Alzheimer's disease-related genes, such as APOE, A2M, PON2 and MAP4, and cardiovascular disease-associated genes, including COMT, CBS and WNK1, all congregated in a single module. Some of the disease-related genes were hub genes while many of them were directly connected to one or more hub genes. Further investigation of this disease-associated module revealed cis-regulatory elements that match to the binding sites of transcription factors involved in Alzheimer's disease and cardiovascular disease. Our results show the extensive links between Alzheimer's disease and cardiovascular disease at the co-expression and co-regulation levels, providing further evidence for the hypothesis that cardiovascular disease and Alzheimer's disease are linked. Our results support the notion that diseases in which the same set of biochemical pathways are affected may tend to co-occur with each other. | 18,842,138 |
The accuracy of symptoms, signs and diagnostic tests in the diagnosis of left ventricular dysfunction in primary care: a diagnostic accuracy systematic review. | To assess the accuracy of findings from the clinical history, symptoms, signs and diagnostic tests (ECG, CXR and natriuretic peptides) in relation to the diagnosis of left ventricular systolic dysfunction (LVSD) in a primary care setting. Diagnostic accuracy systematic review, we searched Medline (1966 to March 2008), EMBASE (1988 to March 2008), Central, Cochrane and ZETOC using a diagnostic accuracy search filter. We included cross-sectional or cohort studies that assess the diagnostic utility of clinical history, symptoms, signs and diagnostic tests, against a reference standard of echocardiography. We calculated pooled positive and negative likelihood ratios and assessed heterogeneity using the I2 index. 24 studies incorporating 10,710 patients were included. The median prevalence of LVSD was 29.9% (inter-quartile range 14% to 37%). No item from the clinical history or symptoms provided sufficient diagnostic information to "rule in" or "rule out" LVSD. Displaced apex beat shows a convincing diagnostic effect with a pooled positive likelihood ratio of 16.0 (8.2-30.9) but this finding occurs infrequently in patients. ECG was the most widely studied diagnostic test, the negative likelihood ratio ranging from 0.06 to 0.6. Natriuretic peptide results were strongly heterogeneous, with negative likelihood ratios ranging from 0.02 to 0.80. Findings from the clinical history and examination are insufficient to "rule in" or "rule out" a diagnosis of LVSD in primary care settings. BNP and ECG measurement appear to have similar diagnostic utility and are most useful in "ruling out" LVSD with a normal test result when the probability of LVSD is in the intermediate range. | 18,842,141 |
Characterization of ten novel Ty1/copia-like retrotransposon families of the grapevine genome. | Retrotransposons make a significant contribution to the size, organization and genetic diversity of their host genomes. To characterize retrotransposon families in the grapevine genome (the fourth crop plant genome sequenced) we have combined two approaches: a PCR-based method for the isolation of RnaseH-LTR sequences with a computer-based sequence similarity search in the whole-genome sequence of PN40024. Supported by a phylogenic analysis, ten novel Ty1/copia families were distinguished in this study. To select a canonical reference element sequence from amongst the various insertions in the genome belonging to each retroelement family, the following screening criteria were adopted to identify the element sequence with: (1) perfect 5 bp-duplication of target sites, (2) the highest level of identity between 5' and 3'-LTR within a single insertion sequence, and (3) longest, un-interrupted coding capacity within the gag-pol ORF. One to eight copies encoding a single putatively functional gag-pol polyprotein were found for three families, indicating that these families could be still autonomous and active. For the others, no autonomous copies were identified. However, a subset of copies within the presumably non-autonomous families had perfect identity between their 5' and 3' LTRs, indicating a recent insertion event. A phylogenic study based on the sequence alignment of the region located between reverse transcriptase domains I and VII distinguished these 10 families from other plant retrotransposons. Including the previously characterized Ty1/copia-like grapevine retrotransposons Tvv1 and Vine 1 and the Ty3/gypsy-like Gret1 in this assessment, a total of 1709 copies were identified for the 13 retrotransposon families, representing 1.24% of the sequenced genome. The copy number per family ranged from 91-212 copies. We performed insertion site profiling for 8 out of the 13 retrotransposon families and confirmed multiple insertions of these elements across the Vitis genus. Insertional polymorphism analysis and dating of full-length copies based on their LTR divergence demonstrated that each family has a particular amplification history, with 71% of the identified copies being inserted within the last 2 million years. The strategy we used efficiently delivered new Ty1/copia-like retrotransposon sequences, increasing the total number of characterized grapevine retrotrotransposons from 3 to 13. We provide insights into the representation and dynamics of the 13 families in the genome. Our data demonstrated that each family has a particular amplification pattern, with 7 families having copies recently inserted within the last 0.2 million year. Among those 7 families with recent insertions, three retain the capacity for activity in the grape genome today. | 18,842,156 |
Mast cells and chemokines. | Chemokines are small proteins (8-12 kD polypeptides) secreted by the cells of innate and adaptive immunity that mediate many of the functions of these cells, including recruitment of other cells. They are classified into families: CC, CXC and CX3C. CXC chemoattract mainly on neutrophils and CC act mainly on monocytes, eosinophils and mast cells. Mast cells are important cells in the modulation of allergic and inflammatory diseases. Activation of mast cells with specific IgE antibody and antigens or other active compounds such as Substance P and corticotrophin releasing hormone causes transcription and translation of several different cytokines/chemokines such as tumor necrosis factor-alpha (TNF-alpha), macrophage inflammatory protein-1 (MIP-1) and GM-CSF, RANTES, MCP-1, CXCL8, along with other proinflammatory compounds, proteases (chymase and tryptase), histamine, leukotrienes and prostaglandin D2. Neutralization of chemokines may reduce inflammatory cell accumulation and may protect against allergy, toxic shock syndrome and inflammatory diseases. | 18,842,167 |
Is there an association between antiphospholipid antibodies and psoriasis? | Ever increasing evidence supports the association between psoriasis and cardiovascular risk. Antiphospholipid antibodies (APAs), which can occur in many autoimmune diseases, are considered prothrombotic and have been associated with atherosclerosis. The aim of this study is to evaluate the prevalence and levels of APAs in psoriasis patients. Fifty patients with moderate to severe plaque psoriasis and 48 healthy subjects were investigated for lupus anticoagulant (LAC) by screening and confirmatory coagulation tests, as well as for antibodies against cardiolipin or beta2-glycoprotein I. Levels of APAs and LAC-related parameters were similar for patients with psoriasis and normal controls (p>0.05). APAs were found in only one psoriatic patient (2%) and in none of the controls. LAC was detected in 2 patients (4%) and in one subject of the control group (2.1%). These results suggest that the prevalence of APAs is not increased in plaque psoriasis as compared to the control group. The increased cardiovascular risk observed in psoriatic patients is therefore likely to be correlated to factors different from APAs. | 18,842,175 |
Effect of impaired glucose tolerance during pregnancy on the expression of VEGF receptors in human placenta. | The aim of the present study was to determine the expression of vascular endothelial growth factor (VEGF) receptors VEGFR-1, VEGFR-2 and VEGFR-3 in placentas from pregnancies complicated by altered glycaemia. Placentas from women with physiological pregnancies (Group 1), pregnancies complicated by minor degree of glucose intolerance (MDGI, Group 2) and by gestational diabetes mellitus (GDM) treated with insulin (Group 3) were collected. Immunohistochemistry, RT-PCR and western blot were employed to evaluate receptor expression. In the three study groups, VEGFR-1 immunoreactivity was detected in all the placental components. VEGFR-2 immunoreactivity was observed in the vessels of all the placentas from Groups 1 and 2, but only in some placentas of Group 3. VEGFR-3 reactivity was observed in all the components of Group 1; in Groups 2 and 3 reactivity was observed in some portions of the trophoblast or the whole trophoblast, and in the stroma. VEGFR-1 and VEGFR-2 mRNA levels in Groups 2 and 3 were significantly higher compared with Group 1, whereas those of VEGFR-3 were significantly lower. Receptor protein levels were significantly lower in Groups 2 and 3 compared with Group 1. These findings demonstrated dysregulation of expression of the three placental receptors, both in GDM and in MDGI. | 18,842,181 |
Porcine embryos produced after intracytoplasmic sperm injection using xenogeneic pig sperm from neonatal testis tissue grafted in mice. | Embryo development after homologous intracytoplasmic sperm injection (ICSI) with sperm from testis tissue xenografts from pigs or any other farm animal species has not been evaluated critically. Here, we report development of porcine embryos in vitro following ICSI with sperm retrieved from xenografted neonatal pig testis. Small pieces of testis tissue from newborn piglets were grafted under the back skin of castrated immunodeficient mice (n = 4) and the xenografts were collected 8 months after grafting. Spermatozoa were recovered by mincing of the grafted tissue. For comparison, testicular, epididymal and ejaculated spermatozoa were also collected from mature boars. Oocytes injected with xenogeneic spermatozoa were either fixed to determine fertilisation processes (n = 89 in five replicates) or allowed to develop in vitro (n = 143 in four replicates). Xenogeneic porcine spermatozoa were fertilisation competent (24% v. 58%, 68%, 62% or 0% for xenogeneic v. control testicular, epididymal and ejaculated spermatozoa or no spermatozoa, respectively) and embryos developed to the blastocyst stage (8% v. 22%, 27%, 25% or 0%, respectively). These results demonstrate that porcine spermatozoa derived from immature testis tissue xenografted into mice are fertilisation competent, albeit at a lower rate than testicular, epididymal or ejaculated spermatozoa from control boars, and support embryo development after ICSI. | 18,842,182 |
Molecular control of mitochondrial function in developing rhesus monkey oocytes and preimplantation-stage embryos. | The mitochondrion undergoes significant functional and structural changes, as well as an increase in number, during preimplantation embryonic development. The mitochondrion generates ATP and regulates a range of cellular processes, such as signal transduction and apoptosis. Therefore, mitochondria contribute to overall oocyte quality and embryo developmental competence. The present study identified, for the first time, the detailed temporal expression of mRNAs related to mitochondrial biogenesis in rhesus monkey oocytes and embryos. Persistent expression of maternally encoded mRNAs was observed, in combination with transcriptional activation and mRNA accumulation at the eight-cell stage, around the time of embryonic genome activation. The expression of these transcripts was significantly altered in oocytes and embryos with reduced developmental potential. In these embryos, most maternally encoded transcripts were precociously depleted. Embryo culture and specific culture media affected the expression of some of these transcripts, including a deficiency in the expression of key transcriptional regulators. Several genes involved in regulating mitochondrial transcription and replication are similarly affected by in vitro conditions and their downregulation may be instrumental in maintaining the mRNA profiles of mitochondrially encoded genes observed in the present study. These data support the hypothesis that the molecular control of mitochondrial biogenesis, and therefore mitochondrial function, is impaired in in vitro-cultured embryos. These results highlight the need for additional studies in human and non-human primate model species to determine how mitochondrial biogenesis can be altered by oocyte and embryo manipulation protocols and whether this affects physiological function in progeny. | 18,842,187 |
[Structured review of activities of daily living measures in older people]. | the present article evaluates the evidence relating to the conceptual adaptation, applicability and psychometric properties of activities of daily living measures in Spanish elderly people. to obtain original documents, electronic searches were carried out in Spanish (IME and ISOC) and international databases (MEDLINE, PsycInfo, CINAHL and EMBASE). Manual searches and reference searches were also conducted. 34 articles relating to 4 instruments met the inclusion criteria: the Barthel Index, the Katz Index, the Red Cross Scale of Physical Disability and the Subscale of Personal Care Activities from the OARS. Overall, the results show a large number of versions for each instrument with weak transcultural adaptation processes and without standards for their administration or interpretation. The most frequently evaluated reliability measure was interrater reproducibility. The evidence on predictive validity is extensive, but the evidence on concurrent validity and responsiveness is almost nil. one version of the Barthel index and another one of the Katz index are the two versions about which the largest quantity of information has been obtained. | 18,842,201 |
[Cognitive markers to discriminate between mild cognitive impairment and normal ageing]. | mild cognitive impairment (MCI) has been characterized as a transitional stage between normal ageing and dementia. The aim of the present study was to examine differences between normal ageing and MCI in the performance of several cognitive tests. These differences might serve as differential markers. we performed a longitudinal study (24 months) with two evaluations at 12-monthly intervals using the CAMCOG-R and a verbal learning test [test de aprendizaje verbal España-Complutense (TAVEC)]. The sample was composed of 25 persons aged more than 50 years old (five men and 20 women), distributed into two groups: the control group and the MCI group. To assign persons to either of the two groups, Petersen's MCI criteria were applied to Mini-Mental State Examination (MMSE) scores. repeated measures ANOVA (2 groups x 2 assessment) showed significant differences between the MCI and control group in the CAMCOG-R scores in orientation, language, memory, abstract thinking, executive function and global score and in the TAVEC scores for immediate recall and short- and long-term free and clued recall. No significant differences were found between the first and second assessment or in the interaction group assessment. the results of the present study confirm that the CAMCOG-R and the TAVEC effectively discriminate between normal ageing and MCI and can be used complementarily. | 18,842,203 |
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