title stringlengths 0 1.13k | abstract stringlengths 1 15.7k | PMID int64 22 36.5M |
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Social support for physical activity of middle school students. | To explore gender and age differences in social support and their relationship with physical activity. This cross-sectional study with enhanced reliability due to repeated measures involved 105 boys and 101 girls. Information on sources and forms of social support, as well as physical activity, was obtained from students, who completed the same questionnaire twice, 2 weeks apart. Boys, compared with girls, were more likely to name fathers and less likely to identify sisters. Compared with older boys, older girls were less likely to identify fathers. Older girls were less likely than both younger girls and older boys to name brothers. Students who identified fathers reported more minutes and days of physical activity and had a stronger physical activity self-definition than those who did not name fathers. Students who selected peers and sisters had more minutes of physical activity and a stronger physical activity self-definition, respectively, than those who did not name peers and sisters. Transportation and encouragement were related to physical activity. Gender differences in social support are not uniform across age groups. Awareness of these differences can inform the development of appropriate physical activity programs. | 18,816,362 |
Surgical difficulties for Total Knee Replacement in Stickler syndrome: A case report. | Stickler syndrome is believed to be the most common connective tissue disorder in Europe and the USA. Severe osteoarthritis sets in at very early age in 3rd to 4th decade of life necessitating joint arthroplasty. This case report highlights the intraoperative surgical difficulties faced by the surgeon and the planning needed for the operation. | 18,816,376 |
Process factors explaining the ineffectiveness of a multidisciplinary fall prevention programme: a process evaluation. | Falls are a major health threat to older community-living people, and initiatives to prevent falls should be a public health priority. We evaluated a Dutch version of a successful British fall prevention programme. Results of this Dutch study showed no effects on falls or daily functioning. In parallel to the effect evaluation, we carried out a detailed process evaluation to assess the feasibility of our multidisciplinary fall prevention programme. The present study reports on the results of this process evaluation. Our fall prevention programme comprised a medical and occupational-therapy assessment, resulting in recommendations and/or referrals to other services if indicated. We used self-administered questionnaires, structured telephone interviews, structured recording forms, structured face-to-face interviews and a plenary group discussion to collect data from participants allocated to the intervention group (n = 166) and from all practitioners who performed the assessments (n = 8). The following outcomes were assessed: the extent to which the multidisciplinary fall prevention programme was performed according to protocol, the nature of the recommendations and referrals provided to the participants, participants' self-reported compliance and participants' and practitioners' opinions about the programme. Both participants and practitioners judged the programme to be feasible. The programme was largely performed according to protocol. The number of referrals and recommendations ensuing from the medical assessment was relatively small. Participants' self-reported compliance as regards contacting their GP to be informed of the recommendations and/or referrals was low to moderate. However, self-reported compliance with such referrals and recommendations was reasonable to good. A large majority of participants reported they had benefited from the programme. The results of the present study show that the programme was feasible for both practitioners and participants. Main factors that seem to be responsible for the lack of effectiveness are the relatively low number of referrals and recommendations ensuing from the medical assessments and participants' low compliance as regards contacting their GP about the results of the medical assessment. We do not recommend implementing the programme in its present form in regular care. ISRCTN64716113. | 18,816,381 |
Tuberculous meningitis presenting with unusual clinical features in Nigerians: Two case reports. | Tuberculous meningitis is common in developing countries and accounts for about 7.8% to 14% of all cases of tuberculosis in Nigeria. Case 1 was a 17-year-old woman who presented with a 3-week history of weakness of the right upper and lower limbs, a 6-hour history of inability to speak and irrational behaviour. She had no remarkable past medical history. Physical examination revealed pyrexia (temperature of 38.2 degrees C) and altered level of consciousness (Glasgow coma score = 7/15). The signs of meningeal irritation were present and she had anisocoria and right spastic hemiparesis. Other aspects of physical examination were normal. Laboratory investigations showed an elevated erythrocyte sedimentation rate, normal cerebrospinal fluid protein and reduced glucose. The brain computed tomography scan showed features in keeping with obstructive hydrocephalus and she was immediately commenced on antituberculous drugs, intravenous steroids and mannitol. She made a remarkable clinical recovery and was discharged home 6 weeks after admission. Case 2 was a 40-year-old man who presented with a 6-week history of headache and fever and a 2-week history of alteration in level of consciousness. There was no history of neck pain and/or stiffness, nausea or vomiting. He had no other remarkable past medical history. He had been placed on various intravenous antibiotics in private hospitals before presentation, with no clinical improvement. Physical examination showed a young man in a coma (Glasgow coma score = 4/15) and febrile (temperature of 38.5 degrees C) with signs of meningeal irritation. The brain stem reflexes were impaired and he had spastic quadriparesis. Further physical examination was essentially normal. The cerebrospinal fluid analysis showed features in keeping with meningeal inflammation and he had a raised erythrocyte sedimentation rate. The brain computed tomography scan showed features in keeping with obstructive hydrocephalus. He was placed on antituberculous drugs and intravenous steroids but despite this his clinical condition deteriorated and he died on the sixth day after admission. Late presentation of tuberculous meningitis is not rare in Nigerians and we report two cases of tuberculous meningitis that presented late to our health care facility. This report is intended to make clinicians aware of the unusual clinical presentations of tuberculous meningitis. | 18,816,394 |
Attitudes towards those bereaved by a suicide: a population-based, cross-sectional study in rural Japan. | Family or friends bereaved by suicide are at risk of experiencing complications because of attitudes regarding suicide. It is important that individuals close to those grieving after a death by suicide demonstrate adequate knowledge and compassionate attitudes. To this end, we examined the factors that contribute to attitudes toward persons bereaved by the suicide of a family member or friend, and perceptions of suicide prevention and the promotion of mental health. A total of 5154 residents of a rural town in northern Japan aged 30-69 years completed a cross-sectional questionnaire. The questionnaire gathered data about demographic variables, depressive symptoms, and issues related to suicide including personal experience of an acquaintance's suicide, attitudes towards those bereaved by suicide, and perceptions regarding suicide prevention. Factors related to these attitudes and perceptions were analysed using logistic regression models. Overall, 67.5% of respondents demonstrated appropriate attitudes towards those bereaved by suicide; 30.4% of responses were undetermined, and 2.1% were inappropriate. Undetermined attitudes were associated with male gender (adjusted OR 1.42, 95%CI = 1.26-1.61), younger age (2.64, 2.12-3.29), lower education level (1.32, 1.07-1.62), greater severity of depression (3.81, 2.80-5.20), and lack of personal experience of an acquaintance's suicide (1.39, 1.22-1.57). Inappropriate attitudes were associated with male gender (adjusted OR 1.98, 95%CI = 1.33-2.94), lower education level (2.55 1.34-4.83), and greater severity of depression (6.93, 3.52-13.67). Overall, 16.0% demonstrated passive thoughts regarding suicide prevention and the promotion of mental health in the community, and were associated with male gender (1.22, 1.04-1.42), younger age (2.72, 2.03-3.65), lower education level (1.32, 1.02-1.71), and greater severity of depression (4.94, 3.58-6.82). Factors that contributed to undetermined attitudes included male gender, younger age, lower education level, greater severity of depression, and lack of personal experience of an acquaintance's suicide. Passive thoughts regarding suicide prevention and the promotion of mental health were associated with male gender, younger age, lower education level, and greater severity of depression. | 18,816,411 |
Measuring care of the elderly: psychometric testing and modification of the Time in Care instrument for measurement of care needs in nursing homes. | Aging entails not only a decrease in the ability to be active, but also a trend toward increased dependence to sustain basic life functions. An important aspect for appropriately elucidating the individual's care needs is the ability to measure them both simply and reliably. Since 2006 a new version of the Time in Care needs (TIC-n) instrument (19-item version) has been explored and used in one additional municipality with the same structure as the one described in an earlier study. The TIC-n assessment was conducted on a total of 1282 care recipients. Factor analysis (principal component) was applied to explore the construct validity of the TIC-n. Cronbach's alpha was calculated to test reliability and for each of the items remaining in the instrument after factor analysis, an inter-rater comparison was carried out on all recipients in both municipalities. Independently of each other, a weighted Kappa (Kw) was calculated. Results. The mean of each weighted Kappa (Kw) for the dimensions in the two municipalities was 0.75 and 0.76, respectively. Factor analysis showed that all 19 items had a factor loading of >or=0.40. Three factors (General Care, Medical Care and Cognitive Care) were created. The TIC-n instrument has now been tested for validity and reliability in two municipalities with satisfactory results. However, TIC-n can not yet be used as a golden standard, but it can be recommended for use of measurement of individual care needs in municipal elderly care. | 18,816,418 |
Integration of acoustic and electrical hearing. | For some individuals with severe high-frequency hearing loss, hearing aids cannot provide a satisfactory improvement in speech recognition. However, these same patients often have too much residual hearing to qualify as candidates for a cochlear implant. Here we describe results with the Iowa/Nucleus Hybrid cochlear implant, which is designed to preserve the patient's residual low-frequency hearing while at the same time supplementing their high-frequency hearing through electrical stimulation. The advantages of this approach are presented, including improved speech recognition in competing backgrounds as compared with traditional cochlear implants. The results with the Iowa/Nucleus Hybrid device demonstrate the ability of the auditory system to integrate acoustic and electrical stimulation, even under conditions of severe distortions to the normal cochlear place-frequency mapping. | 18,816,425 |
[A "simple" method for correction of the Apert's hand]. | In view of the multiple malformations in patients with Apert syndrome, numerous operations need to be carried out on the skull, midface, jaws, hands and in some cases also feet. We describe here a simplified surgical approach to hand surgery that enables several operative steps to be performed during one session and thus reduces the total number of surgical interventions. After visualising with MSCT angiography the bone and soft-tissue malformations and blood vessels, the operation is planned carefully. Transection and removal of the bony and cartilaginous bridges between the symphalangeal fingers is followed by placement of silastic sheets between the separated fingers for a period of 2 - 3 weeks to help form well-vascularised tissue over the spongy bone, which is then covered by full-thickness skin graft to promote healing. Depending on the severity of the Apert hand, numerous surgical procedures can be performed together at one and the same session. This is a simplified method in which the thumb is also straightened either during the same intervention or at a later date. This approach is explained with the help of three of our cases. | 18,816,432 |
Interpretation of positive transcription-mediated amplification test results from polymerase chain reaction-negative samples obtained after treatment of chronic hepatitis C. | The Siemens VERSANT transcription-mediated amplification (TMA) assay is extremely sensitive for the detection of hepatitis C virus (HCV) RNA in serum. Eleven of 180 subjects in the Hepatitis C Antiviral Long-term Treatment against Cirrhosis (HALT-C) Trial who achieved polymerase chain reaction (PCR)-defined sustained virological response (SVR) at week 72 also had TMA-positive results from the same blood draw; six were positive on repeat testing. We report the follow-up on these 11 patients, and the reproducibility of TMA test results from PCR-negative samples in relationship to antiviral treatment outcome. Peginterferon and ribavirin treatment was initiated in 1145 prior interferon nonresponders with advanced hepatic fibrosis. Treatment was continued for 48 weeks if patients had undetectable HCV RNA by PCR at treatment week 20. Frozen serum samples from weeks 12, 20, 24, 48, and 72 were subsequently tested by TMA. Nine of the 11 patients returned for testing (median, 30 months after the week 72 visit), and all had undetectable HCV RNA by TMA and PCR. Among 759 PCR-negative samples obtained during treatment that were tested twice by TMA, 17% overall exhibited consistently positive results, and 21% exhibited inconsistently positive results. SVR was more likely if TMA was consistently negative than if consistently or inconsistently positive. With continued treatment, patients with inconsistently positive TMA results were more likely to become TMA-negative than TMA-positive (P < 0.0001). In PCR-negative samples, positive TMA results may indicate the presence of low levels of HCV RNA. However, because patients with positive TMA results may achieve SVR, management decisions during therapy should not be based on a single positive TMA test result. | 18,816,437 |
Diverse roles of E-cadherin in the morphogenesis of the submandibular gland: insights into the formation of acinar and ductal structures. | The formation of acinar and ductal structures during epithelial tissue branching morphogenesis is not well understood. We report that in the mouse submandibular gland (SMG), acinar and ductal cell fates are determined early in embryonic morphogenesis with E-cadherin playing pivotal roles in development. We identified two morphologically distinct cell populations at the single bud stage, destined for different functions. The outer layer of columnar cells with organized E-cadherin junctions expressed the neonatal acinar marker B1 by E13.5, demonstrating their acinar fate. The interior cells initially lacked distinct E-cadherin junctions, but with morphogenesis formed cytokeratin 7 (K7) -positive ductal structures with organized E-cadherin junctions and F-actin filaments. Inhibition of E-cadherin function with either siRNA or function blocking antibody caused extensive apoptosis of ductal cells and aberrantly dilated lumens, providing the first evidence that E-cadherin regulates ductal lumen formation during branching morphogenesis of the salivary gland. | 18,816,447 |
Transport proteins (carriers) of mitochondria. | Mitochondria are subcellular structures essential to the aerobic eukaryotic cell. Their role extends much beyond their basic reactions of oxidative phosphorylation. It encompasses the steps critical for cellular metabolic pathways, for apoptosis, and for other processes such as antiviral signaling. This short review is limited to transport proteins (carriers) that catalyze the transport of metabolites across the inner mitochondrial membrane and thus link metabolic pathway reactions in the cytosol and the mitochondrial matrix. Such transport must minimally affect the electrochemical proton gradient essential for oxidative phosphorylation (chemiosmotic mechanism of oxidative phosphorylation). Many of these transport proteins belong to a family of membrane proteins, and the major part of this review will consider their structures and functions. First studies of these transporters were carried out with intact mitochondria and with inhibitors that appeared transporter-specific. Such an inhibitor was then utilized in the first purification of one of these transporter proteins. Its substrate-specificity was then established after functionally active incorporation into liposomes. Questions about copurification of other transporters and thus a definitive identification of transported substrate with the purified protein were resolved definitively only after heterologous expression in bacteria, most generally as inclusion bodies, and followed by reconstitution in liposomes. Site-specific mutations permitted the identification of amino acids essential to their transport function. These mutagenesis studies then also helped interpret human diseases with mutations in these transport proteins. The high-resolution structure of a member of this transporter protein family dramatically advanced these studies. It raised new questions because this structure complexed with a high-affinity inhibitor showed a monomeric protein, while purification and inhibitor stoichiometry studies suggest a functional homodimeric transport protein. Remaining key questions need to address: the homodimeric nature of the transporters, details of their transport mechanism, and the functional identification of many members of this family whose existence has only been suggested from genomic data. | 18,816,452 |
Preparative isolation and purification of alkannin/shikonin derivatives from natural products by high-speed counter-current chromatography. | Alkannin and shikonin (A/S) and their derivatives have been found in the roots of several Boraginaceous species and are also produced through plant tissue cultures. The chiral compounds A/S are potent pharmaceutical substances with a wide spectrum of biological and pharmacological activities like wound healing, antimicrobial, anti-inflammatory, anticancer and antioxidant activity. High-speed counter-current chromatography (HSCCC) was applied for the first time to the separation, preparative isolation and purification of A/S and their esters from extracts of Alkanna tinctoria roots, as well as commercial samples. The constituents of HSCCC fractions and their purity were determined by high-performance liquid chromatography-diode array detection-mass spectrometry (HPLC-DAD-MS), since DAD cannot detect oligomeric A/S derivatives that are present in most of the samples containing the respective monomeric derivatives. The purity of HSCCC fractions was compared with the one of fractions isolated by column chromatography (CC) using as stationary phases silica gel and Sephadex LH-20. As shown, the purity of monomeric alkannin/shikonin was greater by HSCCC than CC separation of commercial A/S samples. | 18,816,456 |
Development of an immunochromatographic assay for rapid detection of 1-Aminohydantoin in urine specimens. | A rapid immunochromatographic assay was developed and validated for detection of 1-aminohydantoin (AHD) in urine specimens. Colloidal gold-labeled polyclonal antibody specific to AHD derivative was used as the marker; based on the competitive reactivity theory, the metabolite of nitrofurantoin after derivatization with benzaldehyde would compete with carboxyphenyl AHD derivative-conjugated ovalbumin. The test strip could efficaciously detect the novel analyte with a visual detection limit of 10 ng mL(-1) and high specificity. The reliability of the assay was determined by testing 80 standard samples comparing with enzyme-linked immunosorbent assay. The semi-quantitative detection was accomplished in less than 15 min with low cost, especially for requirements of rapid and simple screening. This is the first publication of an immunochromatographic assay for detection of nitrofuran residues. | 18,816,479 |
Involvement of glycosaminoglycans in vesicular stomatitis virus G glycoprotein pseudotyped lentiviral vector-mediated gene transfer into airway epithelial cells. | The involvement of surface molecules in HIV-1-derived lentivirus (LV)-mediated transduction of airway epithelial cells has not been studied so far. The present study aimed to evaluate the role of glycosaminoglycans (GAGs) in gene transfer mediated by a third generation vesicular stomatitis virus G glycoprotein (VSV-G) pseudotyped LV vector in an in vitro model of polarized airway epithelial cells. Human bronchial (16HBE-S1) and tracheal (CFT1-C2) epithelial cells were grown either on plastic or on filters and transduced with the LV vector polypurine tract (PPT)-green fluoresecent protein (GFP). Zonula Occludens (ZO)-1, a marker of tight junction, and GAG localization were assessed by cytofluorimetry and confocal microscopy. Soluble GAGs and removal of cell surface GAGs were used to affect LV-mediated transduction. Extensive optimization of experimental parameters (presence of polybrene during the infection, the incubation time in the presence of LV particles, period of time intercurring between infection and gene expression analysis) was carried out in plastic-adherent cells. Polybrene resulted to be cytotoxic and was not further used. In CFT1-C2 polarized cells, EGTA treatment determined a 20% decrease in transepithelial resistance, a diminished ZO-1 localization at the tight junction location and a 31% increase in GFP positive cells. Heparane sulfate was distributed evenly on the cell surface. Heparin and soluble chondroitin sulfate A and B inhibited LV-mediated transduction in a dose-dependent fashion. These results were confirmed upon enzymatic removal of GAGs from the cell surface. Taken together, these results show that GAGs are involved in VSV-G LV transduction of airway epithelial cells. | 18,816,484 |
Protein nanotubes comprised of an alternate layer-by-layer assembly using a polycation as an electrostatic glue. | We present the synthesis and structure of various protein nanotubes comprised of an alternate layer-by-layer (LbL) assembly using a polycation as an electrostatic glue. The nanotubes were fabricated by sequential LbL depositions of positively charged polycations and negatively charged proteins into a porous polycarbonate (PC) membrane, followed by release of the cylindrical core by quick dissolution of the template with CH(2)Cl(2). This procedure provides a variety of protein nanotubes without interlayer cross-linking. The three-cycle depositions of poly-L-arginine (PLA) and human serum albumin (HSA, M(w)=66.5 kDa) into the porous PC template (pore diameter, D(p)=400 nm) yielded well-defined (PLA/HSA)(3) nanotubes with an outer diameter of 419+/-29 nm and a wall thickness of 46+/-8 nm, revealed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) observations. The outer diameter of the tubules can be controlled by the pore size of the template (200-800 nm), whereas the wall thickness is always constant, independent of the D(p) value. The (PEI/HSA)(3) (PEI: polyethylenimine) nanotubes showed a slightly thin wall of 39+/-5 nm. CD spectra of the multilayered (PEI/HSA)(n) film on a flat quartz plate suggested that the secondary structure of HSA between the polycations was almost the same as that in aqueous solution. The three-cycle LbL depositions of PLA and ferritin (M(w)=460 kDa) or myoglobin (Mb, M(w)=1.7 kDa) into the porous PC membrane also gave cylindrical hollow structures. The wall thickness of the (PLA/ferritin)(3) and (PLA/Mb)(3) nanotubes were 55+/-5 nm and 31+/-4 nm; it depends on the globular size of the protein (ferritin>HSA>Mb). The individual ferritin molecule was clearly seen in the tubular walls by SEM and TEM measurements. | 18,816,557 |
Why has the health inequality among infants in the US declined? Accounting for the shrinking gap. | Given that wealthier people are healthier, the increase in income inequality over the past two decades has led to fears that inequalities in health have also increased. Indeed, some papers have found that health disparities have become more salient among some adult populations. Using the US Vital Statistics 1983-2000, this paper presents a new stylized fact: the infant health disparity, as measured by Apgar score, neonatal mortality and infant mortality, has been narrowing over the past two decades. This is in sharp contrast to the increasing disparities in health among adults of different educational backgrounds. Using a decomposition method, I find that the most important factor in explaining the closing gap is an increase in access to medical care. All else being equal, access to proper medical care is the most important factor in explaining the narrowing infant health gap. Demographic shifts and maternal behavior changes are also significant factors, together explaining 42.2% of the closing gap in low Apgar score, 41.4% of the closing gap in neonatal death, and 45.6% of the closing gap in infant death. | 18,816,582 |
Adaptive and nonadaptive responses to voluntary wheel running by mdx mice. | The purpose of this study was to determine the extent to which hindlimb muscles of mdx mice adapt to a voluntary endurance type of exercise. mdx and C57BL mice engaged in 8 weeks of wheel running or maintained normal cage activities. Beneficial adaptations that occurred in mdx mice included changes in muscle mass, fiber size, and fiber types based on myosin heavy chain (MHC) isoform expression. These adaptations occurred without increases in fiber central nuclei and embryonic MHC expression. An undesirable outcome, however, was that muscle mitochondrial enzyme activities did not improve with exercise in mdx mice as they did in C57BL mice. Cellular remodeling of dystrophic muscle following exercise has not been studied adequately. In this study we found that some, but not all, of the expected adaptations occurred in mdx mouse muscle. We must better understand these (non)adaptations in order to inform individuals with DMD about the benefits of exercise. | 18,816,601 |
Long-term intensive electrically stimulated cycling by spinal cord-injured people: effect on muscle properties and their relation to power output. | Inactivity and muscular adaptations following spinal cord injury (SCI) result in secondary complications such as cardiovascular disease, obesity, and pressure sores. Functional electrically stimulated (FES) cycling can potentially reduce these complications, but previous studies have provided inconsistent results. We studied the effect of intensive long-term FES cycle training on muscle properties in 11 SCI subjects (mean +/- SEM: 41.8 +/- 2.3 years) who had trained for up to 1 hour/day, 5 days/week, for 1 year. Comparative measurements were made in 10 able-bodied (AB) subjects. Quadriceps maximal electrically stimulated torque increased fivefold (n = 5), but remained lower than in AB individuals. Relative force response at 1 HZ decreased, relaxation rate remained unchanged, and fatigue resistance improved significantly. Power output (PO) improved to a lesser extent than quadriceps torque and not to a greater extent than has been reported previously. We need to understand the factors that limit PO in order to maximize the benefits of FES cycling. | 18,816,613 |
Guideline implementation for breast healthcare in low-income and middle-income countries: overview of the Breast Health Global Initiative Global Summit 2007. | Breast cancer outcomes in low- and middle-income countries (LMCs) correlate with the degree to which 1) cancers are detected at early stages, 2) newly detected cancers can be diagnosed correctly, and 3) appropriately selected multimodality treatment can be provided properly in a timely fashion. The Breast Health Global Initiative (BHGI) invited international experts to review and revise previously developed BHGI resource-stratified guideline tables for early detection, diagnosis, treatment, and healthcare systems. Focus groups addressed specific issues in breast pathology, radiation therapy, and management of locally advanced disease. Process metrics were developed based on the priorities established in the guideline stratification. The groups indicated that cancer prevention through health behavior modification could influence breast cancer incidence in LMCs. Diagnosing breast cancer at earlier stages will reduce breast cancer mortality. Programs to promote breast self-awareness and clinical breast examination and resource-adapted mammographic screening are important early detection steps. Breast imaging, initially with ultrasound and, at higher resource levels with diagnostic mammography, improves preoperative diagnostic assessment and permits image-guided needle sampling. Multimodality therapy includes surgery, radiation, and systemic therapies. Government intervention is needed to address drug-delivery problems relating to high cost and poor access. Guideline dissemination and implementation research plays a crucial role in improving care. Adaptation of technology is needed in LMCs, especially for breast imaging, pathology, radiation therapy, and systemic treatment. Curricula for education and training in LMCs should be developed, applied, and studied in LMC-based learning laboratories to aid information transfer of evidence-based BHGI guidelines. | 18,816,619 |
Vitamin D receptor polymorphisms and the risk of cutaneous melanoma: a systematic review and meta-analysis. | It has been hypothesized that polymorphisms in the vitamin D receptor (VDR) gene affect the risk of developing melanoma. However, results often are conflicting, and no meta-analysis has been performed to date on published data. Six studies (cases, 2152; controls, 2410) that investigated the association between 5 VDR polymorphisms (TaqI, FokI, BsmI, EcoRV, and Cdx2) and the risk of melanoma were retrieved and analyzed. The model-free approach was applied to meta-analyze these molecular association studies. Available data suggested a significant association between the BsmI VDR polymorphism and melanoma risk (pooled odds ratio [OR], 1.30; 95% confidence interval [CI], 1.11-1.53; P= .002; heterogeneity Cochran Q test, P> .1), and the population-attributable risk was 9.2%. In contrast, the FokI polymorphism did not appear to be associated with such risk (OR, 1.09; 95% CI, 0.99-1.21; P= .07; heterogeneity Cochran Q test, P> .1). For the TaqI and the EcoRV polymorphisms, significant between-study heterogeneity did not support genotype data pooling. Only 1 study investigated the Cdx2 variant, and the findings were negative. Current evidence is in favor of an association between 1 VDR gene polymorphism (BsmI) and the risk of developing melanoma. The current findings prompt further investigation on this subject and indirectly support the hypothesis that sun exposure may have an antimelanoma effect through activation of the vitamin D system. | 18,816,636 |
Management of Wilms tumors in Drash and Frasier syndromes. | Children with WT1 gene-related disorders such as Denys-Drash syndrome (DDS) and Frasier syndrome (FS) are at increased risk of Wilms tumor and end-stage renal disease. We investigated whether Wilms tumors in these patients displayed a specific phenotype or behavior and whether nephron-sparing surgery was beneficial. We retrospectively studied all patients with DDS, FS, or other WT1 mutations treated at our institutions between 1980 and 2007. We identified 20 patients, of whom 18 had benign or malignant tumors. Wilms tumors occurred in 15 patients, being unilateral in 10 and bilateral in 5 (20 tumors). Median age at Wilms tumor diagnosis was 9 months. No patients had metastases. According to the International Society of Pediatric Oncology Working Classification, there were 19 intermediate-risk tumors and one high-risk tumor; no tumor was anaplastic. In patients with nephropathy who underwent unilateral nephrectomy for Wilms tumor or nephron-sparing surgery for bilateral Wilms tumor, mean time to dialysis was 11 or 9 months, respectively. Other tumors included three gonadoblastomas (in two patients), one retroperitoneal soft-tissue tumor, and one transitional cell papilloma of the bladder. Two patients, both with stage I Wilms tumor, died from end-stage renal disease-related complications. The median follow-up time for the 18 survivors was 136 months (range, 17-224 months). Most Wilms tumors in children with WT1-related disorders were early-stage and intermediate-risk tumors, with a young age at diagnosis. In patients without end-stage renal disease, nephron-sparing surgery should be considered for delaying the onset of renal failure. | 18,816,692 |
Guanosine improves motor behavior, reduces apoptosis, and stimulates neurogenesis in rats with parkinsonism. | Parkinson's disease (PD) is characterized by progressive degeneration of dopaminergic neurons in the substantia nigra pars compacta (SNc) caused by an abnormal rate of apoptosis. Endogenous stem cells in the adult mammalian brain indicate an innate potential for regeneration and possible resource for neuroregeneration in PD. We previously showed that guanosine prevents apoptosis even when administered 48 hr after the toxin 1-methyl-4-phenylpyridinium (MPP(+)). Here, we induced parkinsonism in rats with a proteasome inhibitor. Guanosine treatment reduced apoptosis, increased tyrosine hydroxylase-positive dopaminergic neurons and expression of tyrosine hydroxylase in the SNc, increased cellular proliferation in the SNc and subventricular zone, and ameliorated symptoms. Proliferating cells in the subventricular zone were nestin-positive adult neural progenitor/stem cells. Fibroblast growth factor-2-expressing cells were also increased by guanosine. Thus, guanosine protected cells from apoptosis and stimulated "intrinsic" adult progenitor/stem cells to become dopaminergic neurons in rats with proteasome inhibitor-induced PD. The cellular/molecular mechanisms underlying these effects may open new avenues for development of novel therapeutics for PD. | 18,816,792 |
Walking speed during single and dual tasks in Parkinson's disease: which characteristics are important? | The impact of dual tasks on gait in Parkinson's disease (PD) reveals lack of automaticity and increased cognitive demands. We explored which characteristics explained walking speed with and without dual task interference and if they reflected the cognitive demands of the task. In 130 people with PD, gait performance was quantified in the home using accelerometers allowing estimates of single and dual task walking speed and interference (difference between dual and single task). Multiple regression analysis was used to explore the effect of 12 characteristics representing four domains (personal, motor symptoms, cognitive, affective) on gait outcomes. Thirty-seven percent of variance in single task speed was explained by increased fear of falling, sex, age, disease severity, and depression; 34% of variance in dual task speed was explained by increased fear of falling, disease severity, medication, and depression; 12% of variance in interference scores was explained by greater disease severity and impaired executive function. Personal, motor, affective, and cognitive characteristics contribute to walking speed and interference, highlighting the multifactorial nature of gait. Different patterns of characteristics for each outcome indicates the impact of cognitive demand and task complexity, providing cautious support for dual task speed and interference as valid proxy measures of cognitive demand in PD gait. | 18,816,800 |
Exponential excitation pulses for improved water content mapping in the presence of background gradients. | Several water content mapping techniques are based on the acquisition of multiple gradient echoes (GE) with different echo times (TE). However, in the presence of linear magnetic field gradients G(susc) the signal decay is no longer exponential but in the case of a rectangular slice profile weighted by a sinc function, giving rise to erroneous initial amplitudes S(0) in monoexponential fitting. Generally, it can be shown that the signal decay is weighted by the time profile of the excitation pulse. Thus, for an excitation pulse with an exponential time profile, i.e., a Lorentzian slice profile, the signal decay remains exponential and exponential fitting still yields the correct amplitude S(0). Multiecho GE images of a gel phantom and five human volunteers were acquired at 3 T using a sinc-shaped and an exponential excitation pulse. In addition, simulations were performed to investigate the influence of saturation effects due to distortion of the ideal Lorentzian slice profile. A considerable overestimation of S(0) when using a sinc-shaped excitation pulse was observed. Errors were greatly reduced with an exponential excitation pulse. We thus propose the use of excitation pulses with exponential time profile to obtain accurate estimates for S(0) from exponential fitting. | 18,816,811 |
Quantitative MR susceptibility mapping using piece-wise constant regularized inversion of the magnetic field. | Magnetic properties characterized by susceptibility and chemical shift linearly modify the local magnetic field experienced by spins. A piece-wise constant solution using magnetic resonance imaging is found to the challenging inversion problem from field to magnetic properties. The magnetic field shifts were estimated from MR phase images. The MR magnitude images were segmented into many regions of uniform magnetic properties. Standard linear regression using the calculated magnetic field from each region allowed accurate susceptibility quantification. The technique was experimentally validated on a variety of samples including water, vegetable oil, air, Gadolinium, and superparamagnetic iron oxides. Susceptibility was measured with a precision better than 0.1 ppm, in a range of 10 ppm. In vivo feasibility was shown on the forearm for which soft-tissue, cortical bone, and bone marrow susceptibility, and chemical shift values in good agreement with literature data were obtained. | 18,816,834 |
Mouse Fem1b interacts with the Nkx3.1 homeoprotein and is required for proper male secondary sexual development. | Previous studies of epithelial cell growth and differentiation in the prostate gland have identified the homeodomain protein Nkx3.1 as a central regulator of prostate development and carcinogenesis. To understand the molecular mechanisms of Nkx3.1 function, we have used yeast two-hybrid analysis to identify Nkx3.1 interacting proteins, and have isolated Fem1b, a mammalian homolog of the C. elegans sex-determining gene Fem-1. In mice, the Fem1b and Nkx3.1 genes encode proteins that interact in glutathione-S-transferase (GST) pull-down and co-immunoprecipitation assays, and are co-expressed in the prostate and testis of neonatal mice. Null mutants for Fem1b generated by gene targeting display defects in prostate ductal morphogenesis and secretory protein expression, similar to phenotypes found in Nkx3.1 mutants. We propose that Fem1b may have a conserved role in the generation of sexual dimorphism through its interaction with Nkx3.1 in the developing prostate gland. | 18,816,836 |
Leading edge-secreted Dpp cooperates with ACK-dependent signaling from the amnioserosa to regulate myosin levels during dorsal closure. | Dorsal closure of the Drosophila embryo is an epithelial fusion in which the epidermal flanks migrate to close a hole in the epidermis occupied by the amnioserosa, a process driven in part by myosin-dependent cell shape change. Dpp signaling is required for the morphogenesis of both tissues, where it promotes transcription of myosin from the zipper (zip) gene. Drosophila has two members of the activated Cdc42-associated kinase (ACK) family: DACK and PR2. Overexpression of DACK in embryos deficient in Dpp signaling can restore zip expression and suppress dorsal closure defects, while reducing the levels of DACK and PR2 simultaneously using mutations or amnioserosa-specific knock down by RNAi results in loss of zip expression. ACK function in the amnioserosa may generate a signal cooperating with Dpp secreted from the epidermis in driving zip expression in these two tissues, ensuring that cell shape changes in dorsal closure occur in a coordinated manner. | 18,816,840 |
Toward understanding the morphogenesis of siliceous spicules in freshwater sponge: differential mRNA expression of spicule-type-specific silicatein genes in Ephydatia fluviatilis. | Siliceous spicules of sponges are morphologically diverse and provide good models for understanding the morphogenesis of biomineralized products. The silica deposition enzyme silicatein is a component of siliceous spicules of sponges and is thought to be the key molecule determining the morphology of spicules. Here, we focused on the silicateins of the freshwater sponge Ephydatia fluviatilis, which has two types of morphologically and functionally different spicules, called megascleres and gemmoscleres. We isolated six isoforms of silicateins and examined their mRNA expression in the cells producing megascleres and gemmoscleres. The spicule-type-specific mRNA expression of these isoforms and differential expression during spicule development suggest that the characteristic morphology of spicules is due to the specific properties and combinatory functions of silicatein isoforms. | 18,816,843 |
Development of the proepicardium in Xenopus laevis. | The proepicardium (PE) is an embryonic progenitor cell population, which provides the epicardium, the majority of the cardiac interstitium, the coronary vasculature and possibly some cardiomyocytes. Recent studies have documented (1) the presence of bilaterally paired PE anlagen in several vertebrates, and (2) species-specific differences in the fate of the left and right PE anlagen. Here, we document PE development in Xenopus laevis (stages 37-46). The PE appears at stage 41 in the form of a cone-shaped accumulation of mesothelial cells covering the pericardial surface of the right horn of the sinus venosus. No such structure appears on the left sinus horn. At the end of stage 41, the tip of the PE establishes a firm contact with the developing ventricle. A secondary tissue bridge is established facilitating the transfer of PE cells to the heart. During stages 41-46, this tissue bridge is visible in vivo through the transparent body wall. Corresponding to the morphological data, the PE marker gene Tbx18 is expressed only on the right sinus horn suggesting a right-sided origin of the PE. Left-right lineage tracing has confirmed this idea. These results show that Xenopus PE development proceeds in a bilaterally asymmetric pattern as previously observed in chicks. We speculate that asymmetric PE development is controlled by signals from left-right signaling pathways and that the PE is an indicator for right-sidedness in Xenopus embryos. Xenopus might be a good model to uncover the role of left-right signaling pathways in the control of asymmetric PE development. | 18,816,844 |
Development of diverse lateral line patterns on the teleost caudal fin. | The lateral line is composed of mechanoreceptors, the neuromasts, which are distributed over the body surfaces of fish. We examine the development of neuromast patterns on the caudal fins of medaka and zebrafish. In medaka, the terminal neuromast is established just prior to the caudal fin formation. The terminal neuromast subsequently gives rise to a cluster of accessory neuromasts. In zebrafish, the terminal neuromasts vary in terms of both number and position, and they achieve their final positions relative to the caudal fin structures through migration. Subsequently, they give rise to four lines of accessory neuromasts that extend along the caudal fin. We show that developmental processes similar to those observed in medaka and zebrafish may account for a large variety of patterns in other teleost species. These results establish terminal neuromast patterning as a new model for the study of the developmental mechanisms underlying diverse lateral line patterns. | 18,816,847 |
Altered white matter diffusion anisotropy in normal and preterm infants at term-equivalent age. | To investigate white matter (WM) development, voxelwise analyses of diffusion tensor MRI (DTMRI) data, acquired from 12 very preterm and 11 preterm infants with gestational ages (GA) ranging from 25 to 29 and 29 to 32 weeks, respectively, and 10 newborn normal term infants were performed. T(2) relaxation measures were also generated to assess brain water content. Compared with newborn term infants, very preterm infants were found to possess reduced fractional anisotropy (FA) within the frontal lobe, and a number of anterior and posterior commissural pathways. Preterm infants possessed reduced FA mainly within the posterior regions of the corpus callosum. Unexpectedly, we observed significantly reduced FA and increased T(2) within a number of corticospinal projections in the newborn term infants compared to the preterm groups. This finding may reflect increased water concentration and/or a lowering of FA due to the presence of crossing interhemispheric WM projections. These findings indicate that care should be taken when interpreting FA indices without knowledge of the possible effects of water concentration in the newborn infant brain. | 18,816,850 |
Thyroid hormone-up-regulated hedgehog interacting protein is involved in larval-to-adult intestinal remodeling by regulating sonic hedgehog signaling pathway in Xenopus laevis. | Sonic hedgehog (Shh) was previously shown to be involved in the larval-to-adult remodeling of the Xenopus laevis intestine. While Shh is transcriptionally regulated by thyroid hormone (TH), the posttranscriptional regulation of Shh signaling during intestinal remodeling is largely unknown. In the present study, we focused on a role of the pan-hedgehog inhibitor, hedgehog interacting protein (Hip), in the spatiotemporal regulation of Shh signaling. Using real-time reverse transcriptase-polymerase chain reaction and in situ hybridization, we show that Hip expression is transiently up-regulated during both natural and TH-induced metamorphosis and that Hip mRNA is localized in the connective tissue adjacent to the adult epithelial primordia expressing Shh. Interestingly, the expression of bone morphogenetic protein-4, a Shh target gene, is hardly detectable where Hip is strongly expressed. Finally, we demonstrate that Hip binds to the N-terminal fragment of processed Shh in vivo, suggesting that Hip suppresses Shh signaling through sequestering Shh. | 18,816,855 |
BOLD imaging in the mouse brain using a turboCRAZED sequence at high magnetic fields. | Functional MRI (fMRI) based on the detection of intermolecular double-quantum coherences (iDQC) has previously been shown to provide pronounced activation signal. For fMRI in small animals at very high magnetic fields, the essential fast gradient echo-based readout methods become problematic. Here, rapid intermolecular double-quantum coherence (iDQC) imaging was implemented, combining the iDQC preparation sequence with a Turbo spin echo-like readout. Four-step phase cycling and a novel intensity-ordered k-space encoding scheme with separate acquisition of odd and even echoes were essential to optimize signal to noise ratio efficiency. Compared with a single echo readout of iDQC signal, acceleration of factor 16 was achieved in phantoms using the novel method at 17.6 Tesla. In vivo, echo trains consisting of 32 echoes were possible and images of the mouse brain were obtained in 30 s. The blood oxygen level dependent (BOLD) effect in the mouse brain upon change of breathing gas was observed as average signal change of (6.3 +/- 1.1)% in iDQC images. Signal changes in conventional multi spin echo images were (4.4 +/- 2.3)% and (8.3 +/- 3.8)% with gradient echo methods. Combination of T(2)*-weighting with the fast iDQC sequence may yield higher signal changes than with either method alone, and establish fast iDQC imaging a robust tool for high field fMRI in small animals. | 18,816,869 |
Extensions to decomposition of the redistributive effect of health care finance. | The total redistributive effect (RE) of health-care finance has been decomposed into vertical, horizontal and reranking effects. The vertical effect has been further decomposed into tax rate and tax structure effects. We extend this latter decomposition to the horizontal and reranking components of the RE. We also show how to measure the vertical, horizontal and reranking effects of each component of the redistributive system, allowing analysis of the RE of health-care finance in the context of that system. The methods are illustrated with application to the RE of health-care financing in Canada. | 18,816,874 |
Metabolic demands of body armor on physical performance in simulated conditions. | The purpose of this study was to examine physical work performance, energy cost, and physiological fatigue in military personnel during simulated operational conditions. Using a within-subject, repeated-measures design, 34 military personnel volunteered to undergo two experimental conditions: with body armor (BA+) and without BA (BA-). Subjects walked on a treadmill for 30 minutes and completed a physical performance battery during each of two sessions, which were separated by > or = 5 days. Subjects with BA+ as compared with BA- had significantly greater increases in: oxygen uptake (VO2) at slow (16.8 +/- 1.5 vs. 18.8 +/- 1.7 mL x kg(-1) x min(-1)) and moderate paces (34.8 +/- 3.9 vs. 40.8 +/- 5.0 mL x kg(-1) x min(-1)); blood lactate at a moderate pace (4.0 +/- 2.4 vs. 6.7 +/- 2.6 mmol/L); heart rate at slow (107 +/- 14 vs. 118 +/- 16 beats per minute) and moderate paces (164 +/- 16 vs. 180 +/- 13 beats per minute); and ratings of perceived physical exertion at slow (8.4 +/- 1.5 vs. 10.4 +/- 1.8) and moderate paces (14.3 +/- 2.3 vs. 16.7 +/- 2.1). Physical tasks were significantly affected by BA: under BA+, men performed 61% fewer pull-ups and women's hang time was reduced by 63%; stair stepping was reduced by 16% for both men and women. BA significantly impacted the physical work capacity of militarily relevant tasks. Specifically, wearing BA significantly increased VO2 when walking at both slow and moderate paces. The potential for physical exhaustion is high and performance of physical tasks is markedly impaired when wearing BA. | 18,816,920 |
Characteristics of domestic violence incidents reported at the scene by volunteer victim advocates. | At a single U.S. Army installation from 1997 to 2005, domestic violence volunteer victim advocates assisted 1,417 clients in 1,380 physical and 301 verbal abuse incidents. The average soldier and spouse population during this time was slightly less than 10,000. Advocates went to the scene of the incident to talk to the victim to ensure that her/his rights were observed, to determine whether the victim was safe, was referred to the hospital social work service for assessment, and had the information necessary to negotiate the complex military and community systems. The advocate inquired of the victim the characteristics of the incident and risk factors in the history of the relationship. In many incidents, risk factors indicated a history of serious violence by the offender including an increasing level of violence, stalking, and assaults. Frequently reported precipitants of incidents were relationship problems, jealously, and infidelity. Spouses often reported previous attempts to leave and to get help. Advocates play an important role in gathering information uniquely available at the scene that can be useful in planning education and intervention programs to reduce domestic violence in the Army, the military services, and civilian society. | 18,816,925 |
Successful treatment of vancomycin-resistant enterococcal ventriculitis in a pediatric patient with linezolid. | Although vancomycin-resistant Enterococcus infection of the central nervous system is not common, this organism is becoming an increasing problem in nosocomial infections. We report a 17-month-old male infant with an externalized ventricular peritoneal shunt secondary to infection who subsequently developed a vancomycin-resistant Enterococcus faecium ventriculitis. This infection was successfully treated with a 28-day course of linezolid while monitoring linezolid drug levels in both the cerebral spinal fluid and serum. This case supports the use of linezolid in treating such resistant infections. However, our drug level results suggest that further investigation is needed to determine the optimal dosing of linezolid in treatment of central nervous system infection in pediatric patients. | 18,816,936 |
Attentional focus effects in balance acrobats. | Performing and learning motor skills has been shown to be enhanced if the performer adopts an external relative to internal focus (or no focus) of attention (Wulf 2007). The present study examined the generalizability of this effect to top-level performers (balance acrobats). Participants performed a balance task (standing on an inflated rubber dish) under each of three attentional focus conditions: (a) external focus (i.e., minimize movements of the disk), (b) internal focus (i.e., minimize movements of the feet), and (c) control conditions (no focus instructions). While there were no differences between conditions in the amount of postural sway, the frequency of movement adjustments was higher in the control condition, relative to both external and internal focus conditions. This suggests that movement automaticity and postural stability were greatest when the balance experts were free to adopt their "normal" focus of attention. The finding implies that there may be a limit to the performance-enhancing effects of external focus instructions for top-level performers. The findings are discussed in terms of action control levels and possible changes in the optimal attentional focus with the performer's level of expertise. | 18,816,943 |
Are preschool children active enough? Objectively measured physical activity levels. | The present study aimed to describe accelerometer-based physical activity levels in 4- and 5-year-old children (N = 76) on 2 weekdays and 2 weekend days. The children were sedentary for 9.6 hr (85%) daily, while they engaged in moderate to vigorous physical activity (MVPA) for 34 min (5%). Only 7% of the children engaged in MVPA for 60 min per day, and only 26% reached the standard of 120 min of total activity. Their engagement in MVPA did not significantly differ between weekend and weekdays. Mean activity counts and minutes in MVPA did not differ between genders. Physical activity levels in this sample of preschool children were far lower than recommended. | 18,816,944 |
How do expert soccer players encode visual information to make decisions in simulated game situations? | The aim of this study was to determine what visual information expert soccer players encode when they are asked to make a decision. We used a repetition-priming paradigm to test the hypothesis that experts encode a soccer pattern's structure independently of the players' physical characteristics (i.e., posture and morphology). The participants were given either realistic (digital photos) or abstract (three-dimensional schematic representations) soccer game patterns. The results showed that the experts benefited from priming effects regardless of how abstract the stimuli were. This suggests that an abstract representation of a realistic pattern (i.e., one that does not include visual information related to the players'physical characteristics) is sufficient to activate experts'specific knowledge during decision making. These results seem to show that expert soccer players encode and store abstract representations of visual patterns in memory. | 18,816,951 |
Evaluating preference assessments for use in the general education population. | This study compared the effectiveness of a multiple-stimulus-without-replacement (MSWO) preference assessment and teacher preference ranking in identifying reinforcers for use in a general education setting with typically developing elementary-school children. The mean number of digits correctly answered was greater in the MSWO-selected reward and the teacher-selected reward conditions relative to the no-reward condition for 2 of the 4 participants, but there were no differences between the MSWO-selected and teacher-selected reward conditions for any participant. | 18,816,985 |
Hematology of the Pascagoula map turtle (Graptemys gibbonsi) and the southeast Asian box turtle (Cuora amboinensis). | Turtle populations are decreasing dramatically due to habitat loss and collection for the food and pet market. This study sought to determine hematologic values in two species of turtles to help assess health status of captive and wild populations. Blood samples were collected from 12 individuals of the Pascagoula map turtle (Graptemys gibbonsi) and seven individuals of the southeast Asian box turtle (Cuora amboinensis) from the Savannah River Ecology Laboratory (South Carolina, USA). The hematologic data included hematocrit, total solids, erythrocyte count, leukocyte count, and differential and percentage leukocyte counts. Low hematocrit values and high basophil counts were found in both species. The basophil was the most abundant leukocyte in the Pascagoula map turtle (median = 0.80 x 10(9)/L), whereas in the Southeast Asian box turtle the most abundant leukocyte was the heterophil (median = 2.06 x 10(9)/L). | 18,817,012 |
Repeat laparotomy for the treatment of septic peritonitis in a Bornean orangutan (Pongo pygmaeus pygmaeus). | A 9-yr-old female Bornean orangutan (Pongo pygmaeus pygmaeus) presented with a 48-hr history of depression, lethargy, anorexia, and mucoid discharge from the rectum. Clinical, radiographic, and ultrasonographic examination demonstrated the presence of multiple distended loops of intestine, intestinal adhesions, and free gas within the abdomen. During exploratory laparotomy, fibrinopurulent diffuse peritonitis as a result of a ruptured intrapelvic abscess with associated large bowel adhesions was evident. The abdomen was thoroughly lavaged, necrotic debris and abscess wall removed, and fibrinous adhesions disrupted. The orangutan was kept sedated for 48 hr to allow for intensive care. Six months later, when the orangutan presented with similar clinical signs, ultrasonographic examination demonstrated the presence of a pelvic abscess. The previous procedure was repeated with the addition of a hysterectomy. This report is the first documentation of long-term management following surgical intervention for internal abdominal abscessation and septic peritonitis in a great ape. | 18,817,016 |
Successful pregnancy outcome following laparoscopic myomectomy: case report. | Laparoscopic myomectomy is now widely used as an alternative to laparotomy in the management of symptomatic uterine fibroids. The advantages of this minimal access approach outweigh those of the open techniques. The pregnancy outcomes between the two methods have been studied and are comparable, but there still exists a lot of scepticism locally concerning this. It is against this background that we present a 31 year old nulliparous lady who had a two year history of primary infertility secondary to multiple uterine fibroids, the largest being fundal and measuring 6.6cm. She underwent a successful laparoscopic myomectomy in November, 2006 and conceived spontaneously in February 2007. Her antenatal follow up was uneventful. She delivered a live male, 2,650 grams by Caesarean section in October, 2007 and had an unremarkable peuperium. With the availability of proper equipment, instruments, and adequately developing skills, laparoscopic myomectomy is feasible locally and with proper patient selection could result in favourable outcome as it is elsewhere. | 18,817,027 |
[Electrophysiological examination of peripheral nerve injury and its significance in forensic medicine]. | Assessment of peripheral nerve injury is a common task in forensic practice. As an objective assistance of inspection, electrophysiological examination is significant in the evaluation of peripheral nerve function after injury. There are currently several methods of electrophysiological examination, including I-T curve, EMG, NCV and SEP. Because electrophysiological examination can assess the injury and regeneration of peripheral nerve injury at different times, it is valuable to estimate prognosis of peripheral nerve injury in forensic medicine. Besides the electrophysiological examination, evaluation of the peripheral nerve injury needs to combine other clinical manifestations to provide an accurate appraisal. | 18,817,040 |
[Tramadol intoxication and its toxicological effect]. | Tramadol is a centrally acting analgesic with a dual mode of action. Its analgesic efficacy is attributed to its partial affinity for the mu-opiate receptor and its inhibition of norepinephrine and serotonin reuptake. Acting in a synergistic manner and being more efficacious, tramadol is used worldwide for the treatment of moderate to severe acute or chronic pain. Abuse and dependence of tramadol as well as tramadol-related deaths have been increasingly reported, either ingested alone or taken in combination with other potentially interacting drugs. The possible toxic effect of tramadol was reviewed from aspects of its analgesic mechanisms, adverse effect, dependence, and abuse. | 18,817,043 |
Health effects of night shift duty on nurses in a university teaching hospital in Benin City, Nigeria. | This study is aimed at identifying the effects of night shift duty on the health and wellbeing of nurses in order to make recommendations on ways of ameliorating them. The study was ofa cross sectional descriptive type using a total sample of nurses in the hospital. Data collection was by means of a semi-structured self-administered questionnaire and the analysis by the computer Programme for Epidemiologists (PEPI). The response rate was 79.3% with a total of 211 (68.1%) having one or more health complaints, which included muscle ache and pains (58.7%), frequent headaches (21.9%), lack of concentration (21.3%) and a negative effect on social life (66.1%). The younger nurses disliked night shift more than the older ones (2 = 57.5, df=6, p = 0.000) and 57.7% felt they were less productive during night shift. The shorter the period of sleep after the night shift, the lesser the level of productivity and the more the manifestation of health symptoms (2 = 45.5, df = 4, p = 0.000 and 2 = 29.0, df = 2, p = 0.000 respectively). Night shift duty caused both medical and psychological problems on the nurses. There is a need for medical surveillance, educational programme and the application of sleep hygiene techniques for shift working nurses. | 18,817,055 |
Profiling of microbial communities in a bioreactor for treating hydrocarbon-sulfide-containing wastewater. | A technology of polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) was used to profile the structure and dynamic changes of microbial communities in a bioreactor for treating hydrocarbon-sulfide-containing (HSC) wastewater. The results showed that the heterotrophic genus of Acinetobacter and the autotrophic genera of Thiobacillus and Thiomonas could survive well in all of three operating conditions. Some special genera were also observed with changes of micro-ecoenvironment in the reactor, such as the halophilic genus of Nesterenkonia. Further, a new genus was found in the reactor, which was likely to have the ability to degrade sulfide and hydrocarbon at the same time. All of these detected and the new found genera have widely applicable potential in the treatment of HSC wastewater. | 18,817,065 |
Extraction of copper from sewage sludge using biodegradable chelant EDDS. | [S,S]-Ethylenediaminedisuccinic acid (EDDS), a biodegradable chelant, was used to separate the heavy metals from the sewage sludge based on chemical extraction technology. Under various conditions, the extraction experiments were carried out for the sewage sludge from Shanghai Taopu Municipal Wastewater Plant, China. The influences of pH and the concentration of EDDS on the extraction efficiency for copper (Cu) were discussed. The results showed that EDDS had higher extraction efficiency for Cu from the sewage sludge than other heavy metals. The system pH and the concentration of EDDS had a significant effect on the extraction efficiency. The extraction efficiency of Cu increased gradually with the increase of system pH and reached a higher efficiency within pH range of 3-10. The extraction efficiency maintained at approximately 70% when the pH > or = 4.5 and the molar ratio of EDDS to total heavy metals was 10:1. From the fractional analysis of the heavy metals in sewage sludge before and after the extraction, it was found that the extracted Cu mainly came from the following four fractions, i.e. water soluble, acid-soluble, reducible, and oxidizable fractions. | 18,817,077 |
A risk assessment system for alien plant bio-invasion in Xiamen, China. | Bio-invasion has caused serious ecosystem damage and enormous economic losses in China, and it has been the greatest factor to island bio-diversity reduction. Xiamen, as an important seaport with a relatively high conservation value, is particularly vulnerable to bio-invasion for its typical island ecosystem as well as frequent human-made disturbance. As a result of field surveys, literature review, and consultation with experts, a list of 67 alien plants identified as major invaders (12 species) and emerging invaders (55 species) in Xiamen has been compiled. Based on the analysis of the current situation of bio-invasion in Xiamen, a risk assessment system for alien plant invasion has been designed using a ranking system and an analytic hierarchy process. The system consists of 17 secondary indices, grouped into 6 primary indices reflecting the different stages in the bio-invasion process: introduction, establishment, dispersion, current range, infestation, and artificial control. Biogeographical, ecological, and experience-linked aspects of the species as well as artificial disturbance were taken into account in the index selection and criterion development. The system was then validated (and worked well) using fifty well-known alien plant species as candidates. Appropriate recommendations are proposed to help local policy-makers prioritize their decisions on such alien plants. | 18,817,080 |
Metastases of clinically occult testicular seminoma mimicking primary extragonadal retroperitoneal germ cell tumors. | Whether extragonadal germ cell tumors develop primarily in the retroperitoneum or whether they are essentially metastases of a primary testicular tumor has long been debated and remains controversial. Three patients presenting with apparent primary extragonadal retroperitoneal germ cell tumors are reported. Ipsilateral testicular evaluation was extended with palpation, ultrasonography and finally histological examination. The retroperitoneal extragonadal tumors were found during abdominal MSCT. It was a fortuitous finding in the two first patients.The third patient presented with abdominal pain attributed to necrosis of the large mass which was subsequently firstly drained through endoscopic ultrasound-guided transduodenal puncture. The seminomatous nature of the retroperitoneal tumors was obtained through transduodenal echoendoscopic-guided cytopuncture in the first case, celioscopic resection in the second case and delayed percutaneous CT guided biopsy in the third symptomatic case. The first two patients had a history of cryptorchidism with substantial clinical testicular atrophy; ultrasonography showed microlithiasis and a small intratesticular tumor in the first patient and an hypoechoic but rather homogeneous atrophic testis in the other; orchiectomy confirmed small seminomatous intratesticular tumors in the two cases. The third patient had an atypical hypoechoic area on testicular ultrasound and histopatholgy revealed a burn-out primary tumor. So-called primary extragonadal retroperitoneal germ cell tumors are extremely rare and should first be considered as metastases of a viable or burned-out testicular cancer until proven otherwise. All ipsilateral testicular abnormalities revealed by the patient's history, clinical examination and mostly by testicular ultrasound must be treated adequately with orchiectomy because they may act as a sanctuary for later tumor growth. | 18,817,085 |
Multivesicular mediastinal hydatid cyst presenting with left recurrent and phrenic nerve palsy. | Hydatid disease caused by Echinococcus granulosus is endemic in Indian subcontinent and a common surgical problem. Although hydatid cyst is common in the liver and lung, it can be encountered in almost every part of the body. Mediastinal hydatid disease is a rare occurrence and only a few cases have been reported in the literature.The present article reports a case of a multivesicular mediastinal hydatid cyst associated with nerve palsies.The patient presented with left recurrent nerve and phrenic nerve palsy. Ultrasonography (US) and computed tomography (CT) of the thorax revealed a multivesicular cyst in the superior mediastinum, the cyst fluid was aspirated and sent for cytology which confirmed the echinococcus as the cause of cystic lesion. Surgical exploration was done by left anterolateral thoracotomy and the cyst was excised. The aim of the present article is to make the reader aware of such rare presentation of hydatid disease especially in endemic areas. | 18,817,089 |
Current management of lobular in situ neoplasia. | Although the term of lobular neoplasia was first proposed in 1978 and the term Lobular In situ Neoplasia (LIN) has been incorporated in the current World Health Organisation (WHO) classification to cover both atypical lobular hyperplasia (ALH) and lobular carcinoma in situ (LCIS), the clinical significance and the natural history of lobular neoplasia is far from being fully understood. Furthermore problems and confusion still remain surrounding (1) the most appropriate terminology and classification for these lesions, (2) the best course of long-term management after diagnosis.This article summarizes the opinions on LCIS management of a group of Belgian experts. | 18,817,092 |
Air and groundwater pollution in an agricultural region of the Turkish Mediterranean coast. | Air pollution and groundwater pollution in conjunction with agricultural activity were investigated in Antayla province on the Turkish Mediterranean coast. The air pollution was investigated in terms of gas-phase nitric acid (HNO3), sulfur dioxide (SO2), ammonia (NH3), and particulate matter for a 6-month period in the atmosphere using a "filter pack" system, which was developed and optimized in our laboratory. Ozone was measured by using an automated analyzer. Among all of the gas-phase pollutants, HNO3 had the lowest concentration (0.42 microg x m(-3)) followed by NH3. Agricultural activities seem to be the major source of observed NH3 in the air. The current state of water pollution was investigated in terms of organochlorine and organophosphorus pesticides around the greenhouses, in which mainly tomato, pepper, and eggplant are cultivated. Water samples were collected from 40 points, 28 of which were wells and 12 of which were surface water. The pesticide concentrations in water samples were determined by means of solid-phase extraction (SPE) followed by a gas chromatography (GC)-electron capture detector (ECD)/nitrogen phosphorus detector (NPD) system. In general, surface water samples were more polluted by the pesticides than groundwater samples. The most frequently observed pesticides were chlorpyriphos (57%) and aldrin (79%) in groundwater, and chlorpyriphos (75%), aldrin, and endosulfan sulfate (83%) in surface water samples. The highest concentrations were observed for fenamiphos (394.8 ng/L) and aldrin (68.51 ng/L) in groundwater, and dichlorvos (322.2 ng/L) and endosulfan sulfate (89.5 ng/L) in surface water samples. At least one pesticide had a concentration above the health limit in 38% of all the water samples analyzed. | 18,817,117 |
Fibrinogen and ceruloplasmin in plasma and milk from dairy cows with subclinical and clinical mastitis. | The potential using of Acute Phase Proteins (APPs) in the assessment of mammary gland health was studied by examining the levels of Fibrinogen (Fb) and Ceruloplasmin (Cp) in plasma and milk from dairy cows with different grades of mastitis. Plasma samples were taken from jugular vein and milk samples were collected from quarters of cows with subclinical and clinical mastitis, as well as healthy controls. California Mastitis Test (CMT) were performed on each udder quarter of cows for detection of CMT2+ and CMT3+ quarters. CMT (0) and culture negative cases were considered healthy cows. Clinical mastitis, was graded as mild (clots in milk) or moderate (clots in milk and visible signs of inflammation in the mammary gland/s). The concentrations of Fb in the plasma of the cows with subclinical and clinical mastitis were higher than in the plasma of the healthy cows (p<0.01). There was no significant difference in plasma concentration of Cp between healthy and subclinical groups (p>0.05), but differences between clinical and healthy groups were significant (p<0.05). The concentrations of Fb and Cp in the milk of the cows with subclinical and clinical mastitis were higher than in the milk of the healthy cows (p<0.01). The results indicated that measurement of Fb in plasma and milk and Cp only in milk might be suitable for early diagnosis of mastitis in dairy cows. | 18,817,128 |
Trophic status and primary production in Lake Choghakhor, Chaharmahal-Bakhtiyari Province, Islamic Republic of Iran. | In this study, trophic state indicators, total phosphate, algal chlorophyll and Secchi disk transparency and zooplankton community of Lake Choghakhor was studied monthly between May 2003 and April 2004. This lake is a shallow ecologically and economically important water body in eastern part of Iran. Crop farming and recreational activities are examples of the human impact around and within the lake, leading to a loading of DIN (Dissolved Inorganic Nitrogen) and TP (Total Phosphate) into the lake. Now submerged plants especially Myriophyllum spicatum has covered almost the entire lake and dense macrophyte beds (Polygonom amphibium), located on the East Southern end of the lake appear to act as a sink for these nutrients. Lake Choghakhor appeared to be in a macrophyte dominated clear water state with low TP (annual mean: 24 +/- 15 microg L(-1)) and chlorophyll a (annual mean: 3 +/- 1.28 microg L(-1)) concentrations and very high Secchi depth. The grazing pressure of dominant pelagic filtering zooplankton Daphnia longespina did not seem to be significant in determining the low phytoplankton crop expressed as chlorophyll a. We expect that sequestering of nutrients by submerged plants and associated epiphytes are the dominant stabilizing mechanisms suppressing the phytoplankton crop of Lake Choghakhor. | 18,817,129 |
Plasma cortisol changes and body composition in Stizostedion lucioperca exposed to handling stress. | Stizostedion lucioperca aquaculture/stoking, remains a restrained industry due to several factors such as the paucity of freshwater resources and studies on the physiological responses of this species under environmental changes. The fish were subjected to handling stress by holding them out of the water in a hand-held dip net for 30 sec and netting the fish from the rearing tanks and transferring them to a small confinement tank. Sufficient aeration was supplied to the confinement tank to revert additional stress from oxygen depletion. Then measured changes in plasma cortisol levels and the growth ability (body composition) in Stizostedion lucioperca subjected to handling stress. Blood samples were collected from the fish after exposure to the handling stress. Crude protein (Nx6.25) was determined according to the Kjeldahl method, moisture content was determined by oven drying at 105+/-2 degrees C to constant weight and ash by heating in a muffle furnace at 550 degrees C to constant weight. Total lipids were extracted according to the Bligh and Dyer method. The results indicated that, handling stress significantly increased the plasma levels of cortisol 59.04 ng mL(-1) versus 40.83 ng mL(-1) in control group. Also the decrease of the level of protein and lipid concentrations show a significant difference between treatment and control (p<0.05). As protein and lipid decreased, moisture increased from 78.19% in control to 80.40% in treatment groups. According to the results, there was no significant change in ash content in control and treatment groups which was about 9%. In other words, it could be emphasized that nutrition-related behavior of Stizostedion lucioperca resulting from the activation of the hypothalamic/inter-renal axis in response to stress despite of different reactions bear resemblance to that of other fishes. Present data indicate that cortisol appears to be adequate to assess stress in Stizostedion lucioperca. | 18,817,137 |
Evaluation of Bt (Bacillus thuringiensis) rice varieties against stem borer (Chilo suppressalis). | Three transgenic rice varieties namely Khazar, Neda and Nemat, all containing a cry1Ab gene, were evaluated through PCR analysis and field examinations for their resistance at natural infestation of insect pests during 2007. The results showed that all transgenic varieties produced 1.2 kb PCR product derived from application of cry1Ab gene. In field conditions, transgenic varieties exhibited high levels of resistance against natural infestation of stem borer and the damaged plants based on dead heart or white heat for them were less than 1%. Moreover, in stem-cut bioassay 100% of released larvae died within four days after infestation. These results demonstrate that expression of cry1Ab gene in the genome of transgenic varieties provided season-long protection from the natural infestation of lepidopteran insects. | 18,817,142 |
Effect of salinity on growth and yield of Desi and Kabuli chickpea cultivars. | To evaluate the effects of different level of Na salinity (0, 3, 6 and 9 dS m(-1)) on growth, yield and yield component of Kabuli (Hashem and Jam) and Desi (Kaka and Pirooz) chickpea cultivars a factorial experiment based on randomized complete block design with four replications was carried out in Research Greenhouse of Mokrian Agricultural Extension Center near Mahabad, Iran at 2006. Seeds of four chickpea cultivars were grown under 0, 3, 6 and 9 dS m(-1) levels of salinity until maturity. Salinity reduced the plant growth, flower, pod and seed number and seed weight. As increase in salinity, the undesirable effect of Na+ was more pronounced and reached the highest value at 9 dS m(-1) in all cultivars. Four chickpea cultivar have different responses to salinity and the Kabuli cultivars seemed to have a greater capacity for salt tolerance compared to Desi cultivars. Hahshem cultivar has the highest salinity tolerance among all cultivars. | 18,817,146 |
Toxicological screening of lyophilized extract of some Nigerian wild mushrooms in mice. | Mushrooms are macrofungi widely consumed as food. However, many mushrooms rot away in the wild because of fear of toxicity. Therefore, lyophilized aqueous extracts of 6 mushroom species collected from Zaria, Nigeria and taxonomically identified as Chlorophyllum molybdites, Panaeolus subalteatus, Macrolepiota procera, Leucopaxillus albissmus, Hygrophoropsis aurantiacus and Pholiota aurea were screened for toxicity in mice. Lyophilized aqueous extract of each of these mushrooms was administered to three groups of 3 mice intraperitoneally (i.p.) at doses of 100, 1000 and 10, 000 mg kg(-1), respectively. Another group of three mice given distilled water served as control. The mice were examined for clinical signs of toxicity over a period of 72 h and pathological examinations conducted on dead animals. The severity of clinical signs, onset of death and pathological lesions were dose dependent. Death occurred within 10 min in all the mice dosed at 10,000 mg kg(-1) with the lyophilized extracts of all the mushrooms screened, with the exception of that of H. aurantiacus, which produced death 21-23 h post administration. This result showed that all the screened mushrooms, including the popular edible M. procera were found toxic. Therefore, since all the mushrooms screened were found toxic, it is recommended that extreme caution should be exercised in their consumption. Furthermore, in view of the regional differences in the toxicity of mushrooms, there is the need to screen more wild mushrooms found in Nigeria for toxicity. This will boost mushroom mycophagy, reduce poisoning incidence and reduce wastage of edible mushrooms in the wild. | 18,817,162 |
Seasonal hair follicle cycle of Camelus dromedarius. | This experiment was conducted to identify the annual changes in hair follicle activity, changes at the follicular level and to characterize some of the fibre-follicle characteristics of camels at different ages. A total of 28 camels were allocated at random on the basis of age to one of four groups (2, 4, 6 and older than 8 years). All groups of camels were fed a maintenance level of ration throughout the experiment. To determine hair follicle cycle and other follicle characteristics samples of skin were taken using a trephine from the right midside of animals at approximately 28 day intervals for a period of 12 months. Using a small hand clipper, 15 g of fibre sample was taken from the left midside region to determine fibre characteristics. Analysis of variance was performed using a one-way SAS package and the means and the standard deviations of means were generated with this program. Mean S/P ratio, primary and secondary and total follicle densities of all groups of camels were 6.85 +/- 0.75, 3.76 +/- 0.63, 22.29 +/- 3.57 and 25.33 +/- 3.85, respectively. Mean fibre diameter, percentage of medullated and non-medullated fibre and clean wool percentage of all groups were 18.98 +/- 1.64, 18.10 +/- 1.65, 81.89 +/- 6.98 and 77.58 +/- 4.58, respectively. Mean percentage of active primary follicles significantly (p < 0.05) decreased to lowest in February to a minimum of 83.1%, then significantly (p < 0.05) increased over spring. Secondary follicle activity decreased over winter and spring to a minimum of 60% in February. | 18,817,164 |
The distribution and coexistence of some wild plants in relation to mineral nutrient availability in a high sodium polluted site in central Sudan. | The factors affecting the distribution and coexistence of Cyperus laevigatus, Typha angustata and Paspalum viginatum, in a high sodium polluted site in central Sudan, were investigated. The high sodium content of the site was mainly due to effluents from a near by textile factory where high quantities of Na compounds, like: NaOH, Na2CO3, Na2SiO3 and NaHCO3 were used in the textile processes. The investigation was carried out by chemical analysis of soil and plant samples and computation of correlation coefficients between soil nutrients and ion uptake by the investigated plants. Soil and plant samples, from the investigated site, were collected from 35 sampling points of 80 x 120 m rectangular grid, each point is 20 m distant from the other neighboring points. Soil chemical analysis data showed that the investigated site was moderately alkaline and characterized by very high content of Na, reasonably high content of Ca, adequate quantities of Mg, K and Fe, low content of NH4-N and P and very low content of Mn. The plant chemical analysis results clearly reflect the different nutritional requirements of the examined plant species. Correlation analysis between soil nutrients and ion uptake by the investigated plants showed that the uptake of a mineral ion by any of the three investigated plant species may be accelerated, slowed down, or may have no obvious effect by another ion in the soil. Moreover, correlation and regression analysis clearly reflect the different patterns of mineral nutrient uptake by the investigated species and hence niche differentiation and coexistence between the investigated species in the investigated site. | 18,817,171 |
Ulcerative gingival granuloma: a condition for bone biopsy. | Osteomyelitis as a medical term defining a specific type of infection may be classified in acute and chronic form. In our case an acute mandibular osteomyelitis is reported with evaluation of the clinical and histological examination. The biological course of the disease determined on that basis. The significance of this report focused on the early diagnosis and the possible need for bone biopsy. | 18,817,182 |
Effect of season on the immunity of newly hatched broiler chicks reared in arid-hot climate. | This study was conducted to investigate the effect of the environmental temperature on the immune response of exotic broiler chicks reared in arid-hot climate zone (the Sudan). Twenty eight broiler chicks (Lohman) were challenged with 1 mL of 10% sheep red blood cells suspension (10% SRBCs) at day 2 and day 13 during summer (June) and winter (January) seasons. At day 13 and day 20 sera were harvested and subjected to hemagglutination test to measure antibody titers against 10% SRBCs for primary and secondary immune response, respectively. In winter season the antibody titers (GMT) against 10% SRBCs for the secondary immune response was so high compared to that in summer season. Nevertheless, the antibody titers for primary immune response during winter and summer seasons were, somehow, identical although it was a little bit higher during winter season. The weights of the lymphoid organs (spleen, thymus and bursa of Fabricius) were significantly higher in the winter season compared to summer season irrespective of the age. | 18,817,214 |
Light and electron microscopic study on a haemogregarine species infecting the viper cerastes Cerastes gasperitti from Saudi Arabia. | A Haemogregarine sp. infecting the Viper Cerastes cerastes gasperitti (35%) from K.S.A. was recorded for the 1st time. Parasites were recorded exclusively in the red blood cells of the Vipers. Erythrocytic parasites measured 17.5 x 3 microm with a nucleus of 8.1 x 2.5 microm. Mature Schizonts of 30 x 2.5 microm and producing 18-30 merozoites by ectomerogony were reported in the endothelial cells of blood capillaries of different internal organs (liver, spleen and lung). The merozoites measured 13 x 3.5 microm and these were similar to the stages in the red blood cells. The motile stages of the parasite recorded in the present study showed all the general architectures of the Apicomplexa with some pecularities such as presence of micronemes and rhoptries at both sides of the nucleus and the occurance of large number of subpellicular microtubules (80-90) extending to the posterior end of the parasite. | 18,817,240 |
Assessment of chronic gastritis in pet dogs and its relation with helicobacter-like organisms. | The aim of this study was to evaluate the prevalence of chronic gastritis in pet dogs, to determine the histopathologic changes of gastric mucosa and, to determine its relationship with canine gastric Helicobacter infection. Sixty percent (n = 18), 27% (n = 8) and 13% (n = 4) of the examined stomachs showed normal, congested and erosive gastric mucosa respectively. Histopathologic examination was confirmed the presence of chronic gastritis in 40% of dogs (n = 12). Lymphocytic-plasmacytic gastritis was the most common type of chronic gastritis. Gastric Helicobacter was detected in cytological examination of 26 out of 30 dogs (86.6%) but in the PCR analysis, 93% of gastric samples were positive for GHLO. There was no significant relation between the presence of Helicobacters and chronic gastritis (p>0.05). Follicular gastritis was detected in 12 cases (40%) and there was also no significant correlation between its presence and GHLO's infection (p>0.05). In conclusion, chronic gastritis can be considered as a prevalent disease especially in dogs. Nutritional and environmental factors as well as individual immune response may have role in induction of chronic gastritis, but the clinical significance of these histopathologic changes should be evaluated. | 18,817,244 |
The seeds quality of Betula pndula Roth and Betula oscura Kotula from semi-natural and anthropogenic habitats. | This research presents the results of the study of seeds quality of two Polish native species of the genus Betula L. (Betula pendula Roth and Betula obscura Kotula), growing on the semi-natural (low human activities) and anthropogenic (high human activities) habitats. In this study the generative phase has been investigated to find differences between studied taxa and try to find out why population of B. obscura is very rare. In this research we have checked the quality of the seeds from B. obscura and B. pendula and test the survival of seedlings sowed into the ground researched in laboratory conditions. Results of germination capacity shown significant difference between trees from the anthropogenic and semi-natural sites; the energy capacity indicated significant difference between trees: B. pendula and B. obscura from all study areas. Mixed-model ANOVA/MANOVA for seedlings growth showed statistically important effects of factors (species, area, months). The results show that B. obscura grows better on the anthropogenic habitats than B. pendula, but the latter had more of the fully developed seeds and higher germination and seeds energy capacity. | 18,817,246 |
Continuation rates and reasons for discontinuing TCu380A IUD use in Sari, Iran. | This study reports results from a 60-month study on the use of TCu380A IUD among 400 women in Sari, Iran. The aim of this study was to assess a sample of women in our region who requested removal of their IUD, continuation rates use and reason for discontinuation. This is a cohort study on 400 women who using the TCu380A IUD and referred to medical health centers of Sari/Iran from May 1999 to May 2006. We randomly selected one half of all health and medical centers in Sari (a total of 20 centers). At each selected center, we randomly sampled 10% of all IUD subjects whose insertion occurred between May 1999 and May 2006. Obtained data were analyzed by descriptive statistical methods. Continuation rates at the end of 1, 2, 3, 4 and 5 years were 96.3, 81.5, 79.2 and 18 per 100, respectively. Median survival time was about 37 months. Among women using the TCu380A IUD, the rate of termination due to bleeding was significantly higher than the rate of termination due to other causes. These findings indicate that family planning educators and health care providers should give more emphasis to counseling programs for women desiring IUD insertion and during follow-up. | 18,817,258 |
Volatile components of Camellia sinensis inhibit growth and biofilm formation of oral streptococci in vitro. | This study aimed to evaluate the efficacy of semi fermented and non fermented Camellia sinensis extracts (Black and Green tea) and comparison between them against Streptococcus mutans ATCC 25175, S. mitis ATCC 9811 and S. sanguis ATCC 10556 that are responsible for dental caries and bacteremias following dental manipulations. Minimum inhibitory concentrations of both tea extracts were assessed by Well diffusion and Broth dilution methods and examination of cell adherence (Biofilm inhibitory concentrations) was observed on glass slides under phase contrast microscope and colony counts from glass beads. Concentration of 1 mg mL(-1) of semi fermented tea extract was completely biofilm inhibitor but biofilm formation by these bacteria was seen 7 days after treatment with 1 mg mL(-1) of non fermented Camellia sinensis on glass beads and BIC for oral streptococci treated with this extract was 1.5, 2.5 mg mL(-1) of semi fermented and 3 mg mL(-1) of non fermented extracts had bactericidal effect on these bacteria. Semi fermented and non fermented Camellia sinensis extracts were able to prevent growth of oral streptococci. Therefore dental caries significantly reduce and the efficiency of semi fermented tea was higher due to rich content of volatile components rather than non fermented extracts. | 18,817,265 |
Growth and some physiological parameters of four sugar beet (Beta vulgaris l.) cultivars as affected by salinity. | The comparative responses of certain biochemical and physiological characteristics to salinity were studied in 4 cultivars of sugar beet (Beta vulgaris L.) plants. Eight weeks old plants were treated with NaCl at 0, 25 and 50 mM in nutrient solutions. Plants were grown under controlled environment and harvested after 3 weeks for measurements of biochemical and physiological parameters. Results showed that in 25 mM NaCl for cultivars of ET5 and C3-3, soluble sugars in leaves, photosynthetic rate and growth parameters were significantly increased as compared to those of other cultivars. In 50 mM NaCl photosynthetic rate and soluble sugars were significantly increased only in ET5 cultivar as compared with those of others. Results indicated that in 25 mM NaCl, ET5 cultivar showed high growth responses and tolerated to 50 mM NaCl. | 18,817,275 |
Computational integration of structural and functional genomics data across species to develop information on the porcine inflammatory gene regulatory pathway. | We are investigating the porcine gut immune response to infection through gene expression profiling. Porcine Affymetrix GeneChip data was obtained from RNA prepared from mesenteric lymph node of swine infected with either Salmonella enterica serovar Typhimurium (ST) or S. Choleraesuis (SC) for 0, 8, 24, 48 or 504 hours post-inoculation (hpi). In total, 2365 genes with statistical evidence for differential expression (DE; p < 0.01, q < 0.26, fold-change > 2) between at least two time-points were identified. Comparative Gene Ontology analyses revealed that a high proportion of annotated DE genes in both infections are involved in immune and defence responses. Hierarchical clustering of expression patterns and annotations showed that 22 of the 83 genes upregulated from 8-24 hpi in the SC infection are known NF-kappaB targets. The promoter sequences of human genes orthologous to the DE genes were collected and TFM-Explorer was used to identify a set of 72 gene promoters with significant over-representation of NF-kappaB DNA-binding motifs. All 22 known NF-kappaB target genes are in this list; we hypothesize that the remaining 51 genes are un-recognized NF-kappaB targets. Integration of these results and verification of putative target genes will increase our understanding of the porcine response pathways responding to bacterial infection. | 18,817,292 |
EST-based gene indices for the cattle fever tick, the horn fly, and the screwworm fly. | The southern cattle tick, Rhip,cephalus (Boophilus) microplus, the horn fly, Haematobia irritans, and the New World screwworm, Cochl,omyia hominivorax, are economically important parasites of cattle throughout the world. Understanding the biology and genomics of these pests is critical to developing novel control methods. We developed EST sequence databases for these parasites and used bioinformatic analysis to identify conceptual open reading frames and assigned Gene Ontology (GO) terms to those database transcripts that had informative BlasIX hits. Bloinformatic analysis showed that a large fraction of the tick database entries have no clear matches in other sequenced genomes. Several putative tick G protein-coupled receptors (GPCRs) were identified that mightserve as starting points to develop novel control technologies. | 18,817,293 |
Physiological interactions between the endocrine and immune systems shown in gene analysis in pigs. | A number of observations support the concept of important physiological interactions between the endocrine and immune systems. It could be confirmed that hormones secreted by the neuroendocrine system play an important role in communication and regulation of the cells of the immune system. Among protein hormones, this has been most clearly documented for prolactin (PRL), growth hormone (GH), and insulin-like growth factor 1 (IGF-1). A number of traits of the immune response in a Duroc x Berlin Miniature pig family (DUMI) were examined. The haemolytic complement activity in the classical complement pathway (CH50) and the alternative pathway (AH50)was examined at eight different time points in pigs that were vaccinated with different vaccines. Single nucleotide polymorphism (SNP) genotyping was employed to genotype the DUMI F2 animal for growth hormone (Gh), growth hormone releasing hormone (Ghrh), pituitary-specific transcription factor 1 (Pit1), and prolactin receptor (Prlr) loci, and also a microsatellite within insulin-like growth factor 1 (Igf1). Using a family-based association test (FBAT) program, a highly significant association of Gh, Pit1, and Prlr to AH50 (p < or = 0.01) and a significant association of Pit1 to CH50 (p < or = 0.05) were found. Using the SAS system for mixed model, a highly significant association of Gh, and Igf1 to AH50 and CH50 (p < or = 0.01) was detected, while Prlr and Ghrh had a highly significant association (p < or = 0.01) with CH50 only. | 18,817,298 |
High resolution, advanced intercross mapping of host resistance to Salmonella colonization. | Availability of a dense single-nucleotide polymorphism (SNP) map in chickens has allowed for whole-genome QTL mapping for disease resistance. In this study, two F8 advanced intercross lines of broiler by Fayoumi and broiler by Leghorn chickens, and a dense, genome-wide SNP panel were used to map genomic regions associated with host resistance to bacterial colonisation. One week after inoculation of day-old chicks with Salmonella enteritidis (SE), caecum and spleen tissues were collected to quantitate the bacterial load. Of 2733 genotyped SNPs, 875 were homozygous and the remaining SNPs with a minor allele frequency of > 0.2 were individually tested for association with SE burden by utilising a Chi-square log-likelihood test between models with and without SNP genotype. Using a Q-value of 25%, calculated utilising 1207 SNPs with Chi-square P-Value < 1.0 to control for false discovery, 21 SNPs identifying 19 genes were significantly associated with SE bacterial levels. Ten genes were in pathways associated with immune response to Salmonella (toll-like receptor signaling, apoptosis, and MAPK signaling), further supporting their involvement in host resistance pathways. In addition to identifying new candidate genes for bacterial resistance, the trait-associated SNPs may be useful in marker assisted selection programmes for disease resistance. | 18,817,304 |
Evaluation of MAFbx expression as a marker for congenital splay leg in piglets. | Splay leg is a hereditary syndrome observed in highly varying frequency in newborn piglets. Although the phenotype indicates a muscular weakness, the etiology is still poorly understood. Only recently, the gene expression of muscle atrophy F-box (MAFbx; FBXO32) was proposed as being of diagnostic value for splay leg in piglet. In this study, total RNA from three healthy and three affected male piglets was isolated. Samples were collected from M. gracilis, Mm. adductores, and M. sartorius. Further samples were taken for histological and biochemical analyses. Expression of MAFbx was analysed by real-time RT-PCR and with the GeneChip" Porcine Genome Array (Affymetrix). No significant differences (p>0.05) were observed in relative MAFbx expression, either between the three muscles or between splay leg and healthy piglets for each muscle. The expression of further atrophy-related genes was unchanged, indicating that splay leg is not characterized by general muscular atrophy in the affected hind limbs. This is supported by histological and biochemical data that does not demonstrate signs of atrophy in splay leg muscles. We conclude that the diagnostic value of MAFbx expression for congenital splay leg in piglets is doubtful and that the disease is characterized by heterogeneous alterations in skeletal muscle. | 18,817,317 |
CDNA microarray analysis of gene expression patterns in blood mononuclear cells of SLA-DRB1-defined Yorkshire pigs. | Three lines of commercialYorkshire pigs with defined SLA-DRB1 alleles were developed at the University of Guelph for xenotransplantation and immune response studies. Two of the SLA-DRB1 alleles have been previously reported (SLA-DRB1*0502 and *0701), whereas the third one is a new allele. The influence of defined SLA-DRB1 alleles on transcriptional patterns of immune-related genes in blood mononuclear cells (BMCs) of pigs was explored using cDNA microarray. Microarray analysis showed significant differential expression of inflammatory genes in association with the various SLA-DRB1 alleles. A better understanding of the association between SLA genotypes and gene activity can increase the knowledge of the function of these molecules, as well as define new strategies to control animal health and optimize animal production. | 18,817,320 |
The use of RNAi and transgenics to develop viral disease resistant livestock. | The possibility of genetically engineering poultry to make them resistant to avian influenza is attracting attention and has now become a real possibility with improved methods for genetic modification and the emergence of RNAi as an antiviral strategy. In order to test this possibility, we have generated transgenic mice that express RNAi molecules targeting a conserved region of the influenza A NP gene and are testing these mice for resistance to influenza infection. Transgenes were initially developed that express short hairpin RNAs (shRNAs) targeting multiple influenza A viral genes. The shRNAs were tested for inhibition of H1N1 PR8 virus in vitro. Two potent shRNAs that target the NP and PA genes were chosen for lentiviral mediated generation of transgenic mice. Transgenic founders for the NP shRNA construct and also a negative control shRNAtargeting EGFP were generated. The constitutive expression of the shRNA molecules in a range of tissue types including lung, was confirmed and so far stable transmission of the RNAi transgenes from the F0 to F3 generation has been observed. Resistance to influenza infection in these transgenic mice is now being confirmed. | 18,817,330 |
[Psychological factors and erectile function in men with refractory chronic prostatitis]. | To study the psychological factors and erectile function in patients with refractory chronic prostatitis. We obtained and compared the scores on the NIH scales of chronic prostatitis symptoms, anxiety, depression and erectile function among 232 refractory and medical chronic prostatitis patients who had never received any psychotherapy. No significant differences were observed in the scores on chronic prostatitis symptoms between the refractory and the medical chronic prostatitis groups, while the scores on anxiety and depression were significantly higher and that on erectile function significantly lower in the refractory than in the medical group (P < 0.01), with a negative correlation between the scores on the former two items and that on the latter. Obvious psychological factors exist in patients with refractory chronic prostatitis, which may affect their erectile function. | 18,817,347 |
Structure-activity relationships in 1,4-benzodioxan-related compounds. 9. From 1,4-benzodioxane to 1,4-dioxane ring as a promising template of novel alpha1D-adrenoreceptor antagonists, 5-HT1A full agonists, and cytotoxic agents. | Novel 1,4-dioxane compounds structurally related to WB 4101 (1) were prepared in order to investigate the possibility that the quite planar 1,4-benzodioxane template of 1 might be replaced by the less conformationally constrained 1,4-dioxane ring. The biological profiles of the new compounds were assessed using binding assays at human cloned alpha 1-adrenoreceptor (alpha 1-AR) subtypes and 5-HT 1A receptors, expressed in Chinese hamster ovary and HeLa cell membranes, respectively, and by functional experiments in isolated rat vas deferens (alpha 1A), spleen (alpha 1B), and aorta (alpha 1D). Moreover, the cytotoxic effects of the novel compounds were determined in PC-3 prostate cancer cells. The results showed that the properly substituted 1,4-dioxane nucleus proved to be a suitable scaffold for selective alpha 1D-AR antagonists (compound 14), potential anticancer agents (compound 13), and full 5-HT 1A receptor agonists (compound 15). In particular, compound 15 may represent a novel lead in the development of highly potent 5-HT 1A receptor full agonists useful as antidepressant and neuroprotective agents. | 18,817,363 |
New directions in the preparation and redox chemistry of fluoride-templated tetranuclear vanadium phosphonate cage compounds, M(n+)[(V2O3)2(RPO3)4<F]n. | A new and simple preparation method for fluoride-templated tetranuclear vanadium phosphonate cage compounds, M(n+)[(V2O3)2(RPO3)4<F]n is outlined. The crystalline products were characterized by X-ray diffraction, elemental analysis, and thermogravimetric analysis. Using the acceptable solubility of the products, multinuclear NMR could be performed on the corresponding solutions. Some insight into the process of formation of the cage compounds in solution could be reached by monitoring the corresponding reaction mixture by multinuclear NMR. The template function of the F(-) ion could be demonstrated together with the fact that the non-transition-metal ions (M(n+)) used here (phosphonium ions) have no direct effect on the formation of the cage. In contrast, the redox behavior of these compounds in the solid state distinctly depends on the cations. This could be easily investigated by electron paramagnetic resonance because the mixed-valence species (3V(V)/V(IV)) can be produced chemically or thermally induced in solution as well as in the solid state. In the latter case, the reaction of the cage with H2 activated on the platinum powder can be regarded as a key experiment for understanding the redox process of the title compounds in the solid state. The role of specific interactions in solution at the tumbling rate and the localization of spin density in the cage could be demonstrated by the reduction performed with 1-methylimidazole and quinoline. While the substituents R = Me and Ph have only a small influence on the cage formation in solution, they have a significant influence on the redox reaction and structural relaxation in the solid state. | 18,817,374 |
Alternative polyadenylation: a twist on mRNA 3' end formation. | Regulation of gene expression by RNA processing mechanisms is now understood to be an important level of control in mammalian cells. Regulation at the level of RNA transcription, splicing, polyadenylation, nucleo-cytoplasmic transport, and translation into polypeptides has been well-studied. Alternative RNA processing events, such as alternative splicing, also have been recognized as key contributors to the complexity of mammalian gene expression. Pre-messenger RNAs (pre-mRNAs) may be polyadenylated in several different ways due to more than one polyadenylation signal, allowing a single gene to encode multiple mRNA transcripts. However, alternative polyadenylation has only recently taken the field as a major player in gene regulation. This review summarizes what is currently known about alternative polyadenylation. It covers results from bioinformatics, as well as those from investigations of viral and tissue-specific studies and, importantly, will set the stage for what is yet to come. | 18,817,380 |
Total synthesis of (+)-cassaine via transannular Diels-Alder reaction. | A full account of the total synthesis of (+)-cassaine ( 1) using the transannular Diels-Alder (TADA) reaction as the pivotal construction is described. The strategy began from Evans' oxazolidine 8, the only chiral source used for the total stereochemical outcome of the target molecule. The key intermediate 3 was obtained from 8 in 10 steps in 40% overall yield. Following extensive optimization, the coupling of 3 on both ends with another densely functional partner 2 followed by TADA reaction on macrocycle 4 cleanly furnished the tricycle 5. The stereochemical outcome in 5 was expected via a least-energetic transition state T4. A stereoselective reduction, hydroboration, and methyl cuprate 1,4-addition along with a few other functional interconversions transformed 5 into the key intermediate 37. Final tethering of dimethylaminoethyloxycarbonyl along with epimerization at C8 and alcohol deprotection at C3 yielded the natural product 1. | 18,817,389 |
Formation and spectroscopy of a tryptophan radical containing peptide in the gas phase. | A doubly deprotonated tryptophan containing peptide was electrosprayed and isolated in an ion trap. UV excitation on this peptide leads to electron detachment and to the formation of an indolyl radical. The photogenerated radical was fragmented by a second laser. The visible spectrum of the gas-phase neutral tryptophan radical containing peptide has been recorded and constitutes a benchmark for calculations and optical measurements. | 18,817,390 |
Bilayer in small bicelles revealed by lipid-protein interactions using NMR spectroscopy. | Intermolecular nuclear Overhauser effects (NOEs) between the integral outer membrane protein OmpX from Escherichia coli and small bicelles of dihexanoyl phosphatidylcholine (DHPC) and dimyristoyl phosphatidylcholine (DMPC) give insights into protein-lipid interactions. Intermolecular NOEs between hydrophobic tails of lipid and protein in the bicelles cover the surface area of OmpX forming a continuous cylindric jacket of approximately 2.7 nm in height. These NOEs originate only from DMPC molecules, and no NOEs from DHPC are observed. Further, these NOEs are mainly from methylene groups of the hydrophobic tails of DMPC, and only a handful of NOEs arise from methyl groups of the hydrophobic tails. The observed contacts indicate that the hydrophobic tails of DMPC are oriented parallel to the surface of OmpX and thus DMPC molecules form a bilayer in the vicinity of the protein. Thus, a bilayer exists in the small bicelles not only in the absence of but also in the presence of a membrane protein. In addition, the number of NOEs between the polar head groups of lipid molecules and protein is increased in the bicelles compared with those in micelles. This observation may be due to the closely packed head groups of the bilayer. Moreover, irregularity of hydrophobic interactions in the middle of the bilayer environment was observed. This observation together with the interactions between polar head groups and proteins gives a possible rationale for structural and functional differences of membrane proteins solubilized in micelles and in bilayer systems and hints at structural differences between protein-free and protein-loaded bilayers. | 18,817,394 |
Polymeric PARACEST agents for enhancing MRI contrast sensitivity. | Linear polymers of PARACEST agents were prepared by using classical free radical chain polymerization conditions. The Eu3+-polymers exhibited similar intermediate-to-slow water exchange and CEST characteristics as the Eu3+-monomers. This provided an avenue to lower the detection limit of these imaging agents substantially and makes them potentially useful as MRI sensors for molecular imaging. | 18,817,395 |
Integrin binding immunoglobulin type filamin domains have variable stability. | Filamin, a large modular protein composed mainly of many immunoglobulin-like domains, is a potent cross-linker of actin filaments. The region containing immunoglobulin type modules 19-21 makes up the binding site for the cytoplasmic tails of the integrin adhesion receptors. Here we investigate the stability of the Ig-like filamin domains using NMR studies over a range of pH and temperature. We show that the 21st Ig-like module (FLNa21) is partly unfolded even under physiological conditions and when attached to FLNa20. It is, however, appreciably stabilized upon binding to integrins. FLNa21 is noticeably less stable than neighboring homologous modules, such as FLNa19 and FLNa17. This variability in stability could be related to the known sensitivity of filamin to cell-mediated mechanical forces. | 18,817,417 |
Microwave, photo- and thermally responsive PNIPAm-gold nanoparticle microgels. | Microwave-, photo- and thermo-responsive polymer microgels that range in size from 500 to 800 microm and are swollen with water were prepared by a novel microarray technique. We used a liquid-liquid dispersion technique in a system of three immiscible liquids to prepare hybrid PNIPAm- co-AM core-shell capsules loaded with AuNPs. The spontaneous encapsulation is a result of the formation of double oil-in-water-in-oil (o/w/o) emulsion. It is facilitated by adjusting the balance of the interfacial tensions between the aqueous phase (in which a water-soluble drug may be dissolved), the monomer phase and the continuous phase. The water-in-oil (w/o) droplets containing 26 wt% NIPAm and Am monomers, 0.1 wt% Tween-80 surfactant, FITC fluorescent dye and colloidal gold nanoparticles spontaneously developed a core-shell morphology that was fixed by in situ photopolymerization. The results demonstrate new reversibly swelling and deswelling AuNP/PNIPAm hybrid core-shell microcapsules and microgels that can be actuated by visible light and/or microwave radiation (<or=1,250 nm) and/or temperature. This is the first study to demonstrate that incorporating AuNPs speeds up the response kinetics of PNIPAm, and hence enhances the sensitivity to external stimuli of PNIPAm. These microgels can have potential applications for microfluidic switches or microactuators, photosensors, and various nanomedicine applications in controlled delivery and release. | 18,817,426 |
Proteomic analysis of oxidative stress-responsive proteins in human pneumocytes: insight into the regulation of DJ-1 expression. | Oxidative injury is believed to play an important role in the pathogenesis of lung diseases such as emphysema and lung cancer. We examined the effects of a classic reactive oxygen species, H 2O 2, on the hydrogen peroxide response proteins (HPRP) in human pneumocytes using comparative two-dimensional gel electrophoresis (2DE) and peptide mass fingerprinting. Four HPRP-associated proteins (DJ-1, peroxiredoxins [Prxs] I and IV and glyceraldehyde-3-phosphate dehydrogenase [GAPDH]) were changed upon exposure to H 2O 2 (1 mM for 24 h). H 2O 2 exposure increased the acid (oxidized) form and decreased the basic (reduced) form of DJ-1 (pI 5.8 and 6.2, respectively), Prx I and IV and GAPDH. Mechanistic studies on DJ-1 indicated that the slow recovery of the reduced form was blocked by cyclohexamide, suggesting that the recovery was due to new protein synthesis. Total DJ-1 expression was decreased by increasing concentrations of H 2O 2. In contrast, a more complex mix of oxidants in the form of cigarette smoke extract (CSE) dose-dependently increased DJ-1 expression and produced a novel DJ-1 isoform (p I 5.6). Moreover, DJ-1 expression was higher in the lungs of chronic cigarette smokers compared with nonsmokers, a result which resembled the effects of CSE in cultured cells. These data indicate that in human pneumocytes, DJ-1 functions as an antioxidant but that no enzymatic system converts the oxidized to the reduced form. Up-regulation of DJ-1 by cigarette smoke may be a compensatory mechanism that protects the lung from oxidative stress-related injury. | 18,817,430 |
The intrinsic stiffness of polyglutamine peptides. | We have used the method of Trp/Cys contact quenching to measure the rate of contact formation in polyglutamine and find it to be a very stiff peptide. Separation of observed rates into reaction-limited and diffusion-limited rates show that the reaction-limited rates increase (rather than decrease) slightly with length between 4 and 16 amino acids. Using Szabo, Schulten, and Schulten theory, we have modeled the results with a wormlike chain with excluded volume and find the persistence length to be about 13.0 A, much longer than has been observed for other random peptides and unfolded proteins. The preferred extended conformation of polyglutamine could account for a propensity for expanded glutamine stretches to unfold the Huntington's protein and the high propensity to aggregate from a disordered monomer. | 18,817,433 |
Insights into melanosomes and melanin from some interesting spatial and temporal properties. | Melanosomes are organelles found in a wide variety of tissues throughout the animal kingdom and exhibit a range of different shapes: spheres of up to approximately 1 mum diameters and ellipsoids with lengths of up to approximately 2 mum and varying aspect ratios. The functions of melanosomes include photoprotection, mitigation of the effects of reactive oxygen species, and metal chelation. The melanosome contains a variety of biological molecules, e.g., proteins and lipids, but the dominant constituent is the pigment melanin, and the functions ascribed to melanosomes are uniquely enabled by the chemical properties of the melanins they contain. In the past decade, there has been significant progress in understanding melanins and their impact on human health. While the molecular details of melanin production and how the pigment is organized within the melanosome determine its properties and biological functions, the physical and chemical properties of the surface of the melanosome are central to their range of ascribed functions. Surprisingly, few studies designed to probe this biological surface have been reported. In this article, we discuss recent work using surface-sensitive analytic, spectroscopic, and imaging techniques to examine the structural and chemical properties of many types of natural pigments: sepia melanin granules, human and bovine ocular melanosomes, human hair melanosomes, and neuromelanin. N 2 adsorption/desorption measurements and atomic force microscopy provide novel insights into surface morphology. The chemical properties of the melanins present on the surface are revealed by X-ray photoelectron spectroscopy and photoemission electron microscopy. These technologies are also applied to elucidate changes in surface properties that occur with aging. Specifically, studies of the surface properties of human retinal pigment epithelium melanosomes as a function of age are stimulating the development of models for their age-dependent behaviors. The article concludes with a brief discussion of important unanswered research questions in this field. | 18,817,437 |
Shape-controlled platinum nanocubes and their assembly into two-dimensional and three-dimensional superlattices. | Liquid-liquid phase transfer has been used to synthesize platinum nanocrystals with a cubic morphology. By finely tuning the parameters controlling the nucleation and growth processes, nanometric truncated cubes or perfect cubes may be obtained. To our knowledge, this is the first time such shapes are obtained with this procedure. The importance of both the length of the capping agent to control the growth process and the bromide anions as poison for the (111) facet is shown. The low degree of size polydispersity allows these nanocrystals to self-assemble with a long-range ordering in two-dimensional and three-dimensional supracrystals. According to the nanocrystal shape, simple cubic or face-centered cubic supracrystals are observed. It is remarkable to notice that well-faceted supracrystals with sizes on the order of 10 microm may be obtained. | 18,817,438 |
Factors governing helix formation in peptides confined to carbon nanotubes. | The effect of confinement on the stability and dynamics of peptides and proteins is relevant in the context of a number of problems in biology and biotechnology. We have examined the stability of different helix-forming sequences upon confinement to a carbon nanotube using Langevin dynamics simulations of a coarse-grained representation of the polypeptide chain. We show that the interplay of several factors that include sequence, solvent conditions, strength (lambda) of nanotube-peptide interactions, and the nanotube diameter (D) determines confinement-induced stability of helicies. In agreement with predictions based on polymer theory, the helical state is entropically stabilized for all sequences when the interaction between the peptide and the nanotube is weakly hydrophobic and D is small. However, there is a strong sequence dependence as the strength of the lambda increases. For an amphiphilic sequence, the helical stability increases with lambda, whereas for polyalanine the diagram of states is a complex function of lambda and D. In addition, decreasing the size of the "hydrophobic patch" lining the nanotube, which mimics the chemical heterogeneity of the ribosome tunnel, increases the helical stability of the polyalanine sequence. Our results provide a framework for interpreting a number of experiments involving the structure formation of peptides in the ribosome tunnel as well as transport of biopolymers through nanotubes. | 18,817,452 |
A national risk assessment for intersex in fish arising from steroid estrogens. | The occurrence of intersex fish is widespread in the rivers of England and Wales. The extent of intersex in fish populations is believed to be strongly linked to their exposure to steroid estrogens. The present study presents, to our knowledge, the first national, catchment-based risk assessment for steroid estrogens in the world. A graphical information system-based model predicted the concentrations of estradiol (E2), estrone, and ethinylestradiol, which were combined and compared with known biological effect levels to predict the risk of endocrine disruption for 10,313 individual river reaches (21,452 km) receiving effluent from more than 2000 sewage treatment plants serving more than 29 million people. The large scale of this assessment underlines the usefulness of computer-based risk assessment methods. Overall, 61% [corrected] of the modeled reaches (all percentages are in terms of the total river length modeled) in England and Wales were predicted to be not at risk from endocrine disruption (mean concentrations, <1 ng/L E2 equivalents). A large range existed in the percentage of river reaches at risk in the various regions, from 5% in Wales to 67% in the Thames catchment. Important factors influencing this proportion are the population density, particularly their location, and the available dilution. A very small proportion of reaches (approximately 1-3%) were predicted to be at high risk (>10 ng/L E2 equivalents). Many of these high-risk reaches, however, were ditches, which were composed almost entirely of sewage effluent. The model could be applied equally well to any other chemical of concern emanating from the human population that would be impractical to assess by measurement. | 18,817,457 |
Prospects for life span extension. | Life expectancy has increased dramatically in the United States and in much of the world in recent years and decades. The factors underlying this increase are incompletely understood and are undoubtedly complex. A question that drives current research is whether life expectancy can be further extended using current knowledge of modifiable risk factors. A still more challenging research focus is on the possibility that life expectancy might be further increased through knowledge gained from studies of the basic biology of aging and its genetic and environmental modifiers. | 18,817,460 |
Dendrimers for enhanced drug solubilization. | Approximately 40% of newly developed drugs are rejected by the pharmaceutical industry and will never benefit a patient because of low water solubility. Another 17% of launched drugs exhibit suboptimal performance for the same reason. Given the growing impact and need for drug delivery, a thorough understanding of delivery technologies that enhance the bioavailability of drugs is important. The high level of control over the dendritic architecture (size, branching density, surface functionality) makes dendrimers ideal excipients for enhanced solubility of poorly water-soluble drugs. Many commercial small-molecule drugs with anticancer, anti-inflammatory and antimicrobial activity have been formulated successfully with dendrimers, such as poly(amidoamine) (PAMAM), poly(propylene imine) (PPI or DAB) and poly(etherhydroxylamine) (PEHAM). Some dendrimers themselves show pharmaceutical activity in these three areas, providing the opportunity for combination therapy in which the dendrimers serve as the drug carrier and simultaneously as an active part of the therapy. | 18,817,470 |
The muscle stem cell niche: regulation of satellite cells during regeneration. | Satellite cells are considered to be adult skeletal muscle stem cells. Their ability to regenerate large muscle defects is highly dependent on their specific niche. When these cells are cultured in vitro, the loss of this niche leads to a loss of proliferative capacity and defective regeneration when implanted back into a muscle defect. The most important aspects of the niche will be discussed--in particular, the basement membrane, the niche's mechanical properties, its supporting cells, and the influence these features have on satellite cell activation, proliferation, and differentiation. Understanding more about the control of these satellite cell activities by the niche will facilitate their recruitment and effective deployment for regenerative medicine. | 18,817,477 |
Cost comparison between telemonitoring and usual care of heart failure: a systematic review. | Heart failure (HF) is associated with high direct and indirect costs to the patients and the healthcare system. This systematic review aims to analyze existing economic data to determine whether telemonitoring of patients with HF will result in decreased costs. The Scopus and PubMed databases were searched independently by two reviewers for journal articles that reported on an economic analysis (i.e., calculated monetary amounts or percentage change in costs) of a study using a HF telemonitoring system. Only articles describing telemonitoring systems with a component of home physiological measurements were included. Eleven articles met the inclusion criteria, describing 10 different HF telemonitoring systems. Nine of the 10 studies analyzed the direct costs to the healthcare system. All the studies found cost reductions from telemonitoring compared to usual care, which ranged between 1.6% and 68.3%. Cost reductions were mainly attributed to reduced hospitalization expenditures. Only one study discussed the impact of HF telemonitoring on direct patient costs. The study found a 3.5% lower travel cost for patients using telemonitoring compared to those in the usual care group. The single study that was found for indirect costs described the willingness to pay for telemedicine by patients with HF (55% of the patients with HF were willing to pay $20 to access telemedicine, and 19% were willing to pay $40). Available data from existing studies suggest that although HF telemonitoring will require an initial financial investment, it will substantially reduce costs in the long term, particularly by reducing rehospitalization and travel costs. | 18,817,497 |
The study of a remote-controlled gastrointestinal drug delivery and sampling system. | A micromachined capsule based on microelectromechanical systems (MEMS) technology is introduced in this paper. It is an effective tool for diagnosing and treating gastrointestinal diseases. The microcapsule can carry out real-time drug release and the gastrointestinal fluid sampling in the gastrointestinal tract. According to the structural and metabolic characters of the gastrointestinal tract, the configuration of the microcapsule was designed as a cylinder. This nondigestible oral device can smoothly pass through the gastrointestinal tract for drug delivery and liquid sampling. The working mechanism of the capsule was the mechanic movement mode of a piston, which was regulated through a MEMS calorific element. The action of drug delivery and gastrointestinal fluid sampling in the gastrointestinal tract was performed wirelessly. The remote control device can be connected with a computer through a serial port (RS-232), and it can be used in telemedicine applications. Some experimental research has been carried out to validate the design. The experimental results indicated that the microcapsule can achieve drug delivery and liquid sample reliably. | 18,817,502 |
Complementary roles of the main and accessory olfactory systems in mammalian mate recognition. | We review studies conducted in mouse and ferret that have specified roles of both the main and the accessory olfactory nervous systems in the detection and processing of body odorants (e.g., urinary pheromones, extraorbital lacrimal gland secretions, major histocompatibility complex peptide ligands, and anal scent gland secretions) that play an essential role in sex discrimination and attraction between males and females leading to mate choice and successful reproduction. We also review literature that compares the forebrain processing of inputs from the two olfactory systems in the two sexes that underlies heterosexual partner preferences. Finally, we review experiments that raise the possibility that body odorants detected by the main olfactory system contribute to mate recognition in humans. | 18,817,511 |
Thermo-responsive systems for controlled drug delivery. | Controlled drug delivery systems represent advanced systems that can be tightly modulated by stimuli in order to treat diseases in which sustained drug release is undesirable. Among the many different stimuli-sensitive delivery systems, temperature-sensitive drug delivery systems offer great potential over their counterparts due to their versatility in design, tunability of phase transition temperatures, passive targeting ability and in situ phase transitions. Thus, thermosensitive drug delivery systems can overcome many of the hurdles of conventional drug delivery systems in order to increase drug efficacies, drug targeting and decrease drug toxicities. In an effort to further control existing temperature-responsive systems, current innovative applications have combined temperature with other stimuli such as pH and light. The result has been the development of highly sophisticated systems, which demonstrate exquisite control over drug release and represent huge advances in biomedical research. | 18,817,514 |
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