title stringlengths 0 1.13k | abstract stringlengths 1 15.7k | PMID int64 22 36.5M |
|---|---|---|
Conjugation of fluorochromes to monoclonal antibodies. | Detection of cell surface molecules labeled by monoclonal or polyclonal antibodies conjugated to a fluorochrome is probably the most widely used application of flow cytometry. This unit contains protocols for tagging monoclonal antibodies with fluorescein, biotin, Texas Red, and phycobiliproteins. In addition, it provides a procedure for preparing a PE-Texas Red tandem conjugate dye that can then be used for antibody conjugation. These protocols enable investigators to label antibodies of their choice with multiple fluorochromes and permit more combinations of antibodies for multicolor flow applications. flow cytometry; monoclonal antibodies; fluorochromes; antibody labeling. | 18,770,708 |
Handling, storage, and preparation of human tissues. | Human tissue for flow cytometry must be prepared as an adequate single-cell suspension. The appropriate methods for tissue collection, transport, storage, and dissociation depend on the cell parameters being measured and the localization of the markers. This unit includes a general method for collecting and transporting human tissue and preparing a tissue imprint. Protocols are supplied for tissue disaggregation by either mechanical or enzymatic means and for preparation of single-cell suspensions of whole cells from fine-needle aspirates, pleural effusions, abdominal fluids, or other body fluids. Other protocols detail preparation of intact nuclei from fresh, frozen, or paraffin-embedded tissue. Support protocols cover fixation, cryospin preparation, cryopreservation, and removal of debris. | 18,770,712 |
Flow analysis and sorting of plant chromosomes. | The use of flow cytometry for evaluation of plant chromosomes requires some specialized attention to preparation and instrumentation. This unit deals exclusively with plant cytogenetics and presents an outline of this area as well as methods for accumulation of cells in metaphase, preparation of chromosome suspensions, flow analysis and sorting of chromosomes, and processing of the sorted chromosomes. Each method is described in tremendous detail because in many aspects dealing with plant cells is quite different from dealing with mammalian cells. Supporting histograms are presented as well as a range of special hints on dealing with plant material and a discussion of the utility of sorted chromosomes for plant genome mapping. | 18,770,713 |
Assessment of viability, immunofluorescence, and DNA content. | This unit addresses the difficult and important area of differentiation between viable and nonviable cells, a question of particular interest for DNA studies. The basic protocol describes the determination of DNA content using pyronin Y combined with dead cell discrimination using 7-AAD. Alternate protocols present methods for DNA content and viability assessment and simultaneous surface or intracellular antigen expression. | 18,770,723 |
Ultraviolet-induced detection of halogenated pyrimidines (UVID). | When halogenated pyrimidines such as BrdU are used to identify DNA-synthesizing cells, their detection with monoclonal antibodies requires DNA denaturation, which can lead to loss of cells and/or cell markers or antigens. The authors present an alternative method employing ultraviolet light to partially photolyze BrdU and induce extensive damage in the nuclei which have incorporated the pyrimidine. Under appropriate conditions the BrdU in the unfolding chromatin is detected by certain monoclonal antibodies. Since no denaturation step or enzymatic treatment is required, this method preserves cellular markers and avoids enzyme-specific artifacts. Directions are given for both coagulative (ethanol) and crosslinking (formaldehyde) fixation. | 18,770,727 |
Analysis of nuclear DNA content and ploidy in higher plants. | This is the first of a series of units discussing the application of cytometry to plant material. Techniques commonly used for mammalian nuclei evaluation need considerable modification to be successful with plant material. David Galbraith and his colleagues bring together many years of knowledge in plant cytometry. Their unit provides detailed protocols on measuring DNA content, ploidy, and cell cycle status of plant tissue using both conventional laser based instruments as well as arc lamp cytometers. This unit provides an excellent starting point for those interested in doing cytometry with plants. | 18,770,733 |
Basic preparative techniques for fluorescence in situ hybridization. | This unit presents protocols for preparing human metaphase chromosome slides from peripheral blood lymphocytes, isolating interphase nuclei from lymphocytes and paraffin-embedded tissues, and preparing DNA fibers. The protocols are designed so that the resulting preparations are amenable to FISH. The methods correspond to a selection of the specimens that can be analyzed with FISH techniques, and the choice of sample preparation method is highly dependent on the molecular cytogenetics question being addressed. | 18,770,740 |
Assessment of surface markers and functionality of dendritic cells (DCs). | Dendritic cells are a complex group of mainly bone marrow derived cells that possess significant ability to take up, process, and present soluble antigens to responder cells in the lymphoid tissues. Characterization of DC surface markers has been a difficult task owing to the lack of appropriate reagents of sufficient specificity. Molecules closely associated with dendritic cells are being identified and investigated and flow cytometric approaches to evaluation of monoclonal antibodies against DC populations are being developed. This informative unit describes assays for determination of the existence of subsets within two DC populations, the kinetics of antigen expression, and the identification of specific markers for DC subsets. A Support Protocol presents an approach for generating dendritic cells and Langerhans cells (a skin-derived DC) from blood monocytes. | 18,770,754 |
Flow cytometric measurement of intracellular pH. | A number of fundamentally important biological processes, such as cell signaling and the initiation of mitosis, are accompanied by a change in intracellular pH. Flow cytometric measurement of pH is a generally straightforward procedure that can be done with any instrument equipped with a 488-nm argon laser. The overall approach is similar to that for calcium: generation of a calibration curve by imparting known changes in pH and interpolation of the test sample pH. This unit presents the traditional calibration method using high-potassium buffers and the proton ionophore nigericin and a more recently developed technique, the pseudo null method, which involves resuspension of cells in defined mixtures of weak acids and weak bases. | 18,770,756 |
Abbreviations used in this manual. | This appendix consists of abbreviations commonly used in cytometry and their definitions. | 18,770,761 |
Immunophenotypic analysis of PNH cells. | Paroxysmal nocturnal hemoglobinuria (PNH) is a rare acquired hematopoietic stem-cell disorder in which a gene mutation results in cellular inability to synthesize the glycosylphosphatidylinositol (GPI) anchors needed to attach various proteins to the cell membrane. Traditional clinical laboratory PNH screening and diagnosis are based upon demonstration of increased erythrocyte susceptibility to lysis by activated complement. These methods are neither very specific nor very sensitive, and have largely been superseded by the rapid, sensitive, and specific flow cytometric analysis of GPI-linked antigen expression. The protocols in this unit cover immunophenotypic analysis of red blood cells, peripheral blood granulocytes, and peripheral blood monocytes, as well as a four-color modification for simultaneous analysis of peripheral blood granulocytes and monocytes. | 18,770,768 |
Labeling of bacterial pathogens for flow cytometric detection and enumeration. | Traditional uses of flow cytometry have been for research and diagnostic purposes, on mammalian cells. This unit focuses on using a flow cytometer for enumerating specific bacteria and parasites. Several different labeling methods are discussed, as well as how to set up a cytometer for detecting and enumerating bacteria. Labeling methods include direct detection with a primary fluorochrome-conjugated antibody and indirect labeling with an unconjugated primary and a fluorochrome-conjugated secondary antibody, as well as labeling with rRNA sequence-specific peptide nucleic-acid probes end-labeled with a fluorochrome. Data and methods throughout this unit focus on detection of Salmonella in clean matrices; however, pertinent information is also provided on using these methods to label other pathogens. The Commentary covers critical aspects of the protocols, and also includes information and suggestions on the application of these methods for testing in the food and pharmaceutical industries, as well as in environmental water testing. | 18,770,788 |
Estimation of microbial viability using flow cytometry. | For microorganisms in particular, viability is a term that is difficult to define and a state consequently difficult to measure. The traditional (and gold-standard) usage equates viability and culturability (i.e., the ability to multiply), but the process of determining culturability is often too slow. Flow cytometry provides the opportunity to make rapid and quantitative measurements of dye uptake in large numbers of cells, and we can therefore exploit the flow cytometric approach to evaluate so-called viability stains and to develop protocols for more routine assessments of microbial viability. This unit is primarily commentary, but several basic protocols have been included to ensure that users have a firm basis for attempting these reasonably difficult assays on traditional flow cytometer instruments. What is clear is that each assay must be carefully validated with the particular microorganism of interest before being applied in any research, clinical, or service form. | 18,770,790 |
Combined immunofluorescence and FISH: new prospects for tumor cell detection/identification. | Fluorescence-microscope based methods are presented that allow automatic selection and quantification of immunophenotyped cells and sequential FISH analysis to facilitate molecular cytogenetic analysis of single cells and very small cell populations. The protocols in this unit are particularly useful for studying the biological and genetic makeup of disseminated tumor cells or other rare cells. | 18,770,807 |
Modern confocal microscopy. | This unit re-examines confocal microscopy from a current perspective. It outlines many of the most modern applications of confocal microscopy and the issues surrounding them. The expanding applications of confocal microscopy demand both minor and major modifications of the technology to enhance imaging capabilities for a growing variety of samples. Techniques of interest such as FRET, FLIP, FRAP, and IFRAP are described. The unit includes a discussion on multispectral imaging, potentially the most exciting innovation in the field of biological imaging. The other area that is beginning to have considerable impact on biology, medicine, and pharmacology comprises high-content screening (HCS) and high-throughput screening (HTS). This unit also introduces programmable array microscopes (PAMs), which are based upon a technique in which spatial modulators are placed in the imaging plane of a microscope and used to generate patterns of illumination and/or detection. | 18,770,814 |
Microsphere surface protein determination using flow cytometry. | This unit describes an extrinsic staining protocol using the amine-reactive CBQCA dye to measure the amount of protein on the surface of a microsphere. This approach is novel in that it allows microspheres bearing proteins without known binding partners to be accurately quantified on a flow cytometer. | 18,770,818 |
Stem cell identification and sorting using the Hoechst 33342 side population (SP). | This unit describes the use of Hoechst 33342 to identify and purify murine hematopoietic stem cells, the so-called side population. Three properties of the dye contribute to the ability to distinguish stem cells in this way. Hoechst is a DNA-binding dye. It has at least two binding modes that result in different spectral properties, allowing resolution of multiple populations by viewing fluorescence at two wavelengths simultaneously. The ability to discriminate SP cells is based on the differential efflux of the dye by a multi-drug-like transporter. Particular attention is given to the critical aspects of Hoechst concentration, cell concentration, staining time, and staining temperature. | 18,770,827 |
Reagents and instruments for multiplexed analysis using microparticles. | Multiplexed molecular analysis by means of flow cytometry using optically encoded microspheres is a rapidly expanding application that has its roots in the earliest days of flow cytometry. The approach is driven by increasing demand for analytical methods to measure large numbers of biomolecules quantitatively and sensitively in small volumes of sample. Encoded microspheres and flow cytometry have been employed for a wide range of multiplexed molecular analysis, and detailed protocols for many of these have been developed. The goal of this unit is to provide an overview of the concepts, instruments, and reagents that enable these assays. | 18,770,838 |
Separation index: an easy-to-use metric for evaluation of different configurations on the same flow cytometer. | A quick and understandable method, using material readily available in a biology laboratory, for evaluating the measurement sensitivity of flow cytometers is presented in detail. Two examples of its use, in determining an optimal emission filter and in evaluating compensation, are also presented. | 18,770,847 |
Detecting protein-protein interactions in vivo with FRET using multiphoton fluorescence lifetime imaging microscopy (FLIM). | Protein interactions are critical for many processes in mammalian cells. Such interactions include the stable association of proteins within multi-subunit complexes and the transient association of regulatory proteins. Information about protein interactions in cells has previously come from either in vitro analyses using recombinant expressed proteins, or from yeast 2-hybrid studies. A limitation of this approach is that the protein interaction is studied in isolation, without regard to the many competing protein interactions that can occur within cells. This unit presents a light microscopy approach for detecting protein-protein interactions in vivo based on the measurement of FRET using the multiphoton fluorescence lifetime imaging microscopy (FLIM) technique. By using the FLIM-FRET technique, the spatial organization and quantification of such interactions in a living cell can be characterized. A detailed protocol describing the complete microscope procedure and the choice of the appropriate experimental controls as well as the FRET calculations is also included. | 18,770,849 |
Polychromatic analysis of mitochondrial membrane potential using JC-1. | Dissipation of the mitochondrial membrane potential (DeltaPsi(m)) has been accepted as a hallmark of some apoptotic processes. Depending on the model studied, it can occur during the early stages of cell death or later on, after loss of DNA integrity. Discordant data in the literature could be the consequence of using improper probes such as rhodamine 123 (R123) or DiOC(6)(3), which are not always appropriate for the study of DeltaPsi(m). The lipophilic cation JC-1, a specific probe for measuring DeltaPsi(m), is currently the gold standard. Thanks to recently developed instruments and additional probes for cell surface and intracellular markers, it can be used in polychromatic flow cytometric assays to simultaneously detect DeltaPsi(m) along with other biological parameters. | 18,770,854 |
Spiro skeletons: a class of privileged structure for chiral ligand design. | This Focus Review highlights the exciting results obtained in the area of asymmetric catalysis using spirobiindane- or spirobifluorene-based chiral ligands. The spiro, mono, and bidentate ligands have been successfully applied in a wide range of transition-metal-catalyzed asymmetric reactions, including hydrogenations, carbon-carbon and carbon-heteroatom coupling reactions, with superior or comparable enantioselectivities to those obtained by using the related ligands bearing other backbones, thus proving that the spiro skeleton is a type of privileged structure for chiral ligand design. It is expected that the spiro concept for chiral ligand design will stimulate the future efforts to understand the features that account for their broad applicability and to apply this understanding to seek new privileged chiral ligands and catalysts. | 18,770,872 |
Proximity to death and participation in the long-term care market. | The extent to which increasing longevity increases per capita demand for long-term care depends on the degree to which utilization is concentrated at the end of life. We estimate the marginal effect of proximity to death, measured by being within 2 years of death, on the probabilities of nursing home and formal home care use, and we determine whether this effect differs by availability of informal care--i.e. marital status and co-residence with an adult child. The analysis uses a sample of elderly aged 70+ from the 1993-2002 Health and Retirement Study. Simultaneous probit models address the joint decisions to use long-term care and co-reside with an adult child. Overall, proximity to death significantly increases the probability of nursing home use by 50.0% and of formal home care use by 12.4%. Availability of informal support significantly reduces the effect of proximity to death. Among married elderly, proximity to death has no effect on institutionalization. In conclusion, proximity to death is one of the main drivers of long-term care use, but changes in sources of informal support, such as an increase in the proportion of married elderly, may lessen its importance in shaping the demand for long-term care. | 18,770,873 |
Neuropsychiatric aspects of coinfection with HIV and hepatitis C virus. | The increasing health care crisis of coinfection with hepatitis C virus (HCV) and HIV has recently attracted the attention of research in the areas of psychiatric and neurocognitive complications related to coinfection. The preliminary data suggest that HIV/HCV coinfection has neurocognitive and psychiatric effects. This review summarizes the findings of what is known about the neurocognitive and psychiatric aspects of HIV/HCV coinfection and discusses the clinical implications and challenges in working with coinfected persons. An integrated, flexible, and interdisciplinary team approach model of treating patients who are coinfected is presented with specific recommendations for clinicians working with this population. | 18,770,900 |
[Saphenous insufficiency. Ambulatory treatment with ligation and vein preservation]. | During years the treatment of the insufficiency of the ostial valve of the Internal Safena (IS) it has consisted of the resection of the vein by means of different techniques. To propose and to evaluate the results of the preservative treatment by means of tie and section of the cayado one of IF with preservation of the vein in Situ. Prospective, experimental and observacional study. Between March of 2005 and May of 2007 47 patients were dealed with with varices of Inferior Members due to an insufficiency of the ostial valve IS. In all the cases it was made tie and section of IF at level of the cayado one with preservation of the vein in Situ in completely ambulatory form. The 93.75% of the treated patients, refered the disappearance of the subjective symptoms, in the 6.25% rest the improvement was partial. There was no morbidity nor mortality inherent to the made procedure. The ambulatory treatment of the ostial insufficiency of IF with preservation of the vein in Situ it demonstrated, in this initial experience, to be effective and safe. | 18,770,934 |
[Endocarditis of pacemaker or implantable cardioverter-defibrillator leads]. | Infective endocarditis includes the endovascular devices infection. The main objective was to evaluate the clinical characteristics and evolution of the endocarditis related to electronics devices. Between 2002 - 2007 periods were identified 7 patients, age average of 56.5 years. The clinical presentation was fever of unknown origin in 85.7%, with a mean of 28 days of evolution. The microbiology isolated was coagulase-negative staphylococci in 6 patients and staphylococcus aureus in 1 patient. The treatment was complete system extraction and antibiotic therapy, except in 1 case that only received antibiotics. There were 2 deaths (28,5%) during in hospital follow-up. The endocarditis related to devices is a disease with high mortality. Early diagnosis and system extraction are very important for the treatment and prognosis. | 18,770,936 |
[Primary ovarian pregnancy (case report)]. | A case of a patients is presented that consults for sharp abdominal pain that is intervened surgically with extirpation of a mass that commits the right annex. Histological preparations showed confirms ovarian pregnancy. | 18,770,938 |
[Benign recurrent intrahepatic cholestasis type-II--a rare cause of direct hyperbilirubinemia exacerbations with hepatic fibrosis]. | Direct hyperbilirubinemia, may result from a variety of pathologies, including structural obstructions with biliary tract occlusions (as in cholelithiasis), infections (e.g. hepatitis) and genetic disorders (Rotor's and Dubin-Johnson's syndrome). One of the less common and probably more frequently underdiagnosed causes is benign recurrent intrahepatic cholestasis (BRIC). First described in 1959, BRIC was further classified into two subgroups which differ in their pathogenesis and clinical manifestation. Both BRIC types originate from impaired function bile salt excretion from hepatocytes to the canaliculi which is mediated by the bile salt export pump (BSEP) which is located on the hepatyocyte membrane, unevenly distributed within the membrane lipid bilayer. In BRIC type-I, a mutation impairs the asymmetrical distribution of BSEP. In BRIC type-II, a mutation occurs directly damaging the BSEP. Apart from cholestasis, clinical manifestations of BRIC type-I include extra-hepatic symptoms such as watery diarrhea, pancreatitis and hearing impairment. Patients with BRIC type-II present mainly with hepatobiliary disease such as colelithiasis. In the past, BRIC was conventionally considered to result in no more than canalicular cholestasis, however several reports have associated BRIC with fibrosis and porto-portal septa formation. Disease course may last between weeks and months, more common in females, at any age, and usually resolves spontaneously, although chronic liver disease has also been described. Treatment modalities range from expectant management, medication (cholestyramine, ursolit) or even surgery (biliary bypass/liver transplantation). This report describes a patient with BRIC type-II and reviews the relevant literature. | 18,770,956 |
[Three-dimensional conformal radiation therapy concurrent with full dose Gemcitabine for locally advanced inoperable pancreatic cancer]. | Gemcitabine is a potent radiosensitizer of pancreatic cancer cells. Concomitant full dose Gemcitabine and three dimensional conformal radiation to a small field is a novel approach to unresectable locally advanced pancreatic cancer. The aim of this study is to report the outcome, tolerability and toxicity of this combined therapy. A retrospective chart review, with survival data confirmed by the population registry and statistic analysis was performed with SPSS. Radiotherapy was planned using computerized tomography, treated only the gross tumor without regional lymph nodes and was delivered in 15 fractions of 2.4 Gy to a dose of 36 Gy. Gemcitabine was administered weekly during radiation at a dose of 1000 mg/m2. Gastrointestinal toxicity was scored according to the NCI Common Toxicity Criteria. Local control was assessed by RECIST criteria, a partial response defined as a decrease of at least 30% in the longest diameter of the tumor. Eighteen of the 19 patients completed treatment as planned without the need for treatment break. Four patients subsequently developed severe grade III-IV gastrointestinal toxicity; 37% of patients achieved a partial response and 52% experienced significant clinical benefit. The median survival was 11.7 months. Full dose gemcitabine with conformal 3-D radiotherapy to a small field was well tolerated and was associated with a low incidence of severe gastrointestinal toxicity compared with previous studies of combination therapy using standard large radiation portals which encompass both the tumor and the regional lymph nodes. A partial response was observed in over one third of patients, non-progression of the irradiated tumor in the rest with pain relief and clinical benefit in more than half the patients. This treatment approach was well tolerated with little morbidity and achieves outcomes equal to or better than other contemporary combination modality approaches. | 18,770,957 |
The relationship among mathematics anxiety, beliefs about mathematics, mathematics self-efficacy, and mathematics performance in associate degree nursing students. | This research explored nursing students' mathematics anxiety, beliefs about mathematics, and mathematics self-efficacy in relation to performance on a medication mathematics test. Results revealed that the participants experienced some mathematics anxiety and had positive beliefs about mathematics and mathematics self-efficacy. Qualitative responses indicated that participants worried about the consequences of failing the medication mathematics test and that practice helped reduce this anxiety. In addition, participants acknowledged the importance of correct dosage calculations for nursing practice. Implications for nursing education are discussed. | 18,770,952 |
[Conscience, principled refusal and ethics of refusal to provide treatment to a patient's request]. | There are situations in which refusal to provide treatment according to a patient's request may be justified by ethical rules and principles of medical ethics. This article explores such situations, analyzing the various factors which a physician may consider when refusal to provide treatment is at stake. The article focuses on three major states of affairs under which the question of whether a physician has liberty to refuse to treat may occur: refusals deriving from conflicts between the physician's personal values and ones reflected in the proposed treatment; refusals stemming from general considerations to be classified as policy reasons; and refusals following a clinical assessment as to the proposed treatment, expected chances of recovery and expected benefit to the patient. The ethical analysis of the article leads to the conclusion that a physician may (although he/she does not have a right to) refuse to provide medical treatment following a patient's request when the physician's refusal originates in conscientious resistance. However, the physician may not refuse to treat when refusal is based on policy considerations or concerns third parties not immediately involved in the physician-patient relationship. In addition, a physician may refuse to provide treatment following a medical assessment when and if the proposed treatment is not urgently required, if the provision of treatment may create risks to the patient's health, if its conferral may inflict pain or suffering exceeding its expected benefits to the patient, or the proposed treatment is futile and its chances to combat the disease are significantly minimal. | 18,770,960 |
Characterization and activity of cephalosporin metal complexes. | Semi-synthetic cephalosporin antibiotics have structures similar to that of penicillins, and both groups of compounds are characterized by similar properties and determined by the same methods. Most antibiotics, including cephalosporins and their decomposition products, contain electron donor groups that can bind naturally occurring metal ions in vivo. Cephalosporin antibiotics exhibit a change in their toxicological properties and biological performance when they were tested as metal complexes. The proposed reason for such a behavior is the capability of chelate binding of the cephalosporins to the metals. In an attempt to understand the coordination mode of metals with cephalosporins, different spectroscopic techniques such as IR, UV-visible, NMR spectroscopy and voltammetric measurements were carried out to elucidate the structure of the metal-cephalosporin complexes. Synthesis, characterization and biological screening of the cephalosporins and of the cephalosporin-metal complexes are discussed in this review. However, little information is available on the influence of the metal ions on the pharmacokinetics of the cephalosporin derivatives. | 18,771,001 |
Transcriptome alterations in the prefrontal cortex of subjects with schizophrenia who committed suicide. | To better understand the pathophysiological events associate with suicide in subjects with schizophrenia, we performed a DNA microarray expression profiling of the frontal cortex of subjects with schizophrenia who committed suicide, subjects with schizophrenia who died of non-suicidal causes and matched control subjects. Simultaneous expression profiling for >40,000 genes was performed using HU133A and HU133B Affymetrix oligonucleotide arrays. We conclude that suicide in schizophrenia is associated with a number of gene expression changes in the prefrontal cortex that are distinct from both of that observed in controls and subjects with schizophrenia who did not commit suicide. Furthermore, the observed gene expression signature contains a prefrontal cortical downregulation of the HTR2A serotonin receptor transcript, strengthening previously reported genetic susceptibility reports. As the observed transcript changes are likely developing over days or weeks, these data argue that the molecular predisposition to suicide develops significantly earlier than the act of suicide occurs. Finally, the presented data also strengthens previous reports of neuroimmune transcriptome disturbances in subjects with schizophrenia. | 18,771,015 |
Is transmission of HIV-1 in non-viraemic serodiscordant couples possible? | Several studies have shown that HIV-1 transmission in serodiscordant couples is significantly reduced when the plasma viral load (pVL) in the infected partner is low or undetectable. However, residual infectivity in the seminal compartment despite undetectable pVL has also been shown. Here we report HIV-1 transmission in a serodiscordant couple despite successful antiretroviral therapy of the HIV-infected partner. The newly infected partner had a negative HIV-1 screening ELISA when his HIV-1-positive partner was already on antiretroviral treatment with undetectable pVL, which remained undetectable beyond the time of seroconversion in the initially negative partner. Frozen blood samples were analyzed phylogenetically from the HIV-1-positive patient and the newly infected partner before treatment and shortly after seroconversion, respectively; they showed a true relationship. On the basis of these data, the present report suggests that transmission of HIV-1 can occur despite undetectable pVL. This should be added to the discussion of prevention strategies, which should not advise the abandonment of safer-sex practices without referring to the relatively low but not impossible risk of HIV-1 transmission in this context. | 18,771,057 |
The times they are a changin': marital status and health differentials from 1972 to 2003. | Although the meanings and rates of being married, divorced, separated, never-married, and widowed have changed significantly over the past several decades, we know very little about historical trends in the relationship between marital status and health. Our analysis of pooled data from the National Health Interview Survey from 1972 to 2003 shows that the self-rated health of the never-married has improved over the past three decades. Moreover, the gap between the married and the never married has steadily converged over time for men but not for women. In contrast, the self-rated health of the widowed, divorced, and separated worsened over time relative to the married, and the adverse effects of marital dissolution have increased more for women than for men. Our findings highlight the importance of social change in shaping the impact of marital status on self-reported health and challenge long-held assumptions about gender, marital status, and health. | 18,771,061 |
The formation of a socioeconomic health disparity: the case of cocaine use during the 1980s and 1990s. | Despite the substantial and prolonged sociological interest in health disparities, much remains unknown about the processes that initiate them. To investigate this topic, we focus on the case study of cocaine use, for which a socioeconomic disparity emerged across all age groups in a short period of time around 1990. We examine whether the newly-formed disparity represents a selective remnant of previous users or, instead, a selective recruitment of new users. To evaluate these two potential processes we use latent class regression on a nationally representative cohort with repeated measures of past-year cocaine use before and after 1990. Results support the "remnant" hypothesis and show that the newly-formed disparity resulted primarily because people in the lower social strata were less likely to have a trajectory of cocaine use with a sharp drop in use after 1990. These results point to the "remnant" concept as a way to bring together disparity analysis of very different and diverse health outcomes. | 18,771,068 |
Bortezomib as a therapeutic candidate for neuroblastoma. | Outcomes remain poor in neuroblastoma despite intensive treatment. Agents with potential efficacy can be drawn from anti-neoplastic drugs introduced for other malignancies. Bortezomib, a proteasome inhibitor, modulates cell-signaling molecules leading to apoptosis. Bortezomib, alone and in combination with other agents, was tested across an in vitro panel of neuroblastic, stromal, and chemo-resistant neuroblastoma cell types to determine its effect on cell viability and to assess for interactions between bortezomib and other chemotherapeutic agents that either limit or increase overall response. Each subtype of neuroblastoma was sensitive to bortezomib and killing occurred with EC50 values of approximately 50 nM. When bortezomib was combined with other agents (doxorubicin, etoposide, SN-38, carboplatin, or cisplatin), no antagonism was observed. The bortezomib-doxorubicin combination was especially effective, demonstrating synergy on isobolographic analysis and resulting in a decrease in EC50 from 50 ng/mL with doxorubicin alone to 5 ng/mL with 25 nM bortezomib. Interestingly, the different cell types exhibited varying response patterns to treatment with bortezomib alone and in combination with other drugs suggesting different mechanisms may be engaged. A decision analysis, incorporating these results showing efficacy in all cell types, the synergy obtained in combination, and the available toxicity data, supports a phase II clinical trial of bortezomib in neuroblastoma. | 18,771,087 |
Human Borna disease virus-infection and its therapy in affective disorders. | Patients with affective disorders show an enhanced prevalence of Borna disease virus (BDV)-infection. Furthermore, BDV causes latent infection preferably in limbic central nervous structures and is suggested to be causally related to subtypes of affective disorders, especially with melancholic clinical features or bipolarity. Such a possible link was highlighted by the first report of amantadine showing an antidepressive and an antiviral efficacy against BDV in a patient with a bipolar disorder. This article summarizes clinical studies which followed this first report on the use of amantadine in BDV-infected patients with an affective disorder. A special focus is given on an open clinical study in patients with depression (n = 25), a study in remitted patients with affective disorders (n = 16), and the effect of amantadine on severe hypomanic or moderately manic patients with a bipolar disorder in an on-off-on study. In these studies amantadine reduced clinical symptoms paralleled by a reduction of BDV-infection in depressive patients, it also reduced all three BDV-parameters (BDV-Ab, -AG, and -CICs) in remitted patients, and it even reduced severe hypomania and moderate mania in bipolar patients. These data suggest the existence of an etiopathogenetic link between BDV and subtypes of affective disorders. | 18,771,101 |
Homosexual experience, desire and identity among young adults. | Is young people's sexuality becoming more fluid and less tied to steady, stable identity patterns? Are we developing into a society where sexual relationships between individuals of the same sex are no longer reserved for the small minority of gay men and lesbian women? Adherents of so-called queer theory have promulgated such views. Using a population-based sample of young adults (aged 19 to 26, N 2753), we investigated homosexual experiences, desire and identity. We found that levels of prevalence of homosexuality were primarily a function of the criteria we used. Using the most restricted ("narrow") definitions, we found that about one percent of both genders reported "exclusive" homosexual interest and identity. Using the most inclusive criteria, we found that one of ten young men and one of four young women reported having some homosexual experience, interest or identity. Still, the most striking finding involved the substantial gender-specific differences: homoerotic activity and interest are far more interwoven with heterosexual activity for women. There are strong indications that homosexuality is a lot more threatening and potentially in conflict with traditional male gender roles than we find to be the case for women. In other words, while there may be signs of more fluid sexual identity categories, this phenomenon primarily applies to women. | 18,771,114 |
[Retroperitoneal endoscopic adrenalectomy vs. conventional adrenalectomy in treatment of benign adrenal lesions--comparative analysis]. | Miniinvasive adrenalectomy is considered to be the standard of care for the surgical treatment of the adrenal gland's pathology. Since the initial report of laparoscopic adrenalectomy in 1992 and of retroperitoneal endoscopic adrenalectomy in 1994, it has evolved into a feasible and safe minimally invasive procedure for benign adrenal tumors. Clinical characteristics and outcomes of 63 retroperitoneal endoscopic adrenalectomies (REAs) and 45 conventional adrenalectomies (CAs) from 1996 to 2004 were evaluated. 61 patients underwent 63 REAs. Tumor size varied from 2 to 8 cm. Median age was 48.6 years. Mean operative time was 135 min (45-240), mean intraoperative blood loss - 85 ml (30-550). The complication rate was 17.77%. Median postoperative hospital stay was 5 days (2-10). 44 patients underwent 45 conventional adenalectomies. Median age was 44.5 years (16-71). Intraoperative complication rate was 17.77%, postoperative - 22.22%, Mean operative time was 120 min (75-240). Median postoperative hospital stay was 10 days (6-21). No statistically significant difference was established between mean operative times of REA- and CA-groups (p=0.91). Conventional adrenalectomy was associated with a significantly increased complication rate (p=0.009). Hospitalization was also longer after the open technique (p < 0.0001). Introduced in 1994 and displaying all advantages of minimal access surgery REA has become the standard of care for benign adrenal tumors. | 18,771,144 |
[Experience of systematization on the treatment of patients with upper jaws fractures, during the period 1991-2000]. | A retrospecive analysis was done of the 128 patients with fractures in a upper jaw, treated during the period 1991-2000. The treatment of the patients with partial fractures in a alveolar part of maxilla and frontal wall of maxillary sinus, consist of debridement on the open wound, primery stiched and stabilization by arch bar of perspective teeth. In the cases with fractures of tuber maxilla and opening of maxillary sinus they tray to clouse it by Rhermann technique, with or without radical antrothomy by Caldwell-Luc technique. On the patients by total upper jaw fractures they try lead by princip of duble stage fixation: from one side-of intact upper bone structures and the other side-on a mandible. On the cases of upper jaw fractures, combine with barain traums. was treated conservativly - the specialize treatment of facial injures was postpoun until stabilization of brain status. | 18,771,150 |
[Characteristics of the spontaneously transformed human endothelial cell line ECV304. I. Multiple chromosomal rearrangements in endothelial cells ECV304]. | Karyotype of endothelial line ECV304 cells obtained from human umbilicus vein endothelial cells was studied using G-banding chromosome staining. It has been revealed that the cells have a polyploidy karyotype with 96-112 chromosomes and multiple numerical and structural clonal rearrangements. Almost all the chromosomes of the karyotype are involved in structural rearrangements. There are several double chromosome rearrangements revealed including del(9)(p21) as well as two derivatives of chromosome 3 with the breakpoint in the locus p25 - der(3)t(3;12)(3p25;12q11- 12q24.?1) and der(3)t(3;?)(3p25). The role of these rearrangements in the immortalization of endothelial cells and sighs of transformation are discussed. In connection with the information received about the fact that the cells of ECV304 line are not endothelial cells but T24, urinary bladder cancer cells (which karyotype was studied by Hurst et al., 2000), the comparative analysis of the karyotypes of these two lines was carried out. It has been revealed that these two lines differ by all cytogenetic characteristics. Neither identical structural chromosomal rearrangements nor cell characteristic of urinary bladder cancer cells were detected. Our line ECV304 is not identical to the line T24. | 18,771,171 |
[How I treat... paracetamol poisoning]. | Drug self-poisoning is a common cause of admission in ED. Among various incriminated substances, paracetamol is often implicated and presents a severe toxicity. We briefly describe the epidemiology and physiopathology of paracetamol self-poisoning. We then clarify the diagnostic elements, thresholds of toxicity, indications for treatment and different available therapeutic guidelines. | 18,771,223 |
Electrochemical pinning of the Fermi level: mediation of photoluminescence from gallium nitride and zinc oxide. | Charge transfer between diamond and an electrochemical redox couple in an adsorbed water film has recently been shown to pin the Fermi level in hydrogen-terminated diamond. Here we show that this effect is a more general phenomenon and influences the properties of other semiconductors when the band lineup between the ambient and electronic states in the semiconductor is appropriate. We find that the luminescent intensities from GaN and ZnO change in different, but predictable, ways when exposed to HCl and NH3 vapors in humid air. The effect is reversible and has been observed on single crystals, nanowires, flakes, and powders. These observations are explained by electron exchange between the oxygen electrochemical redox couple in an adsorbed water film and electronic states in the semiconductor. This effect can take place in parallel with other processes such as defect formation, chemisorption, and surface reconstruction and may play an important, but previously unrecognized, role when electronic and optical measurements are made in air. | 18,771,263 |
Structural requirements for key residues and auxiliary portions of a BLUF domain. | BlrB in Rhodobacter sphaeroides is a single domain, flavin-based blue light sensor protein in the BLUF family of photoreceptors. Consistent with other members of this family, blue light excitation induces a putative signaling state characterized by a 10 nm red shift in the UV-visible absorbance spectrum. Structural and spectroscopic characterization of truncated BlrB constructs establishes that the C-terminal 50 amino acids of this protein are essential to its structural integrity despite not being part of the canonical BLUF domain architecture. Mutagenesis studies support the critical roles of Tyr9, Asn33, and Gln51 for flavin binding and the integrity of the BLUF domain fold. Comparison of solution NMR spectra of BlrB acquired under dark and light conditions indicates very limited light-dependent conformational changes except for a few interesting residues: Trp92, Met94, and Ile127. Notably, the Ile127 side chain experiences significant chemical shift changes despite the fact that it is far ( approximately 15 A) from the flavin chromophore in the C-terminal extension. These data suggest that the light-induced signal is propagated from the flavin through the beta sheet to the last two alpha helices in the C-terminal extension, potentially providing a mechanism to transmit this change to initiate a cellular response to blue light. | 18,771,279 |
Kinetic mechanism of protein arginine methyltransferase 1. | Protein arginine methyltransferases (PRMTs) are SAM-dependent enzymes that catalyze the mono- and dimethylation of peptidyl arginine residues. Although all PRMTs produce monomethyl arginine (MMA), type 1 PRMTs go on to form asymmetrically dimethylated arginine (ADMA), while type 2 enzymes form symmetrically dimethylated arginine (SDMA). PRMT1 is the major type 1 PRMT in vivo, thus it is the primary producer of the competitive NOS inhibitor, ADMA. Hence, potent inhibitors, which are highly selective for this particular isozyme, could serve as excellent therapeutics for heart disease. However, the design of such inhibitors is impeded by a lack of information regarding this enzyme's kinetic and catalytic mechanisms. Herein we report an analysis of the kinetic mechanism of human PRMT1 using both an unmethylated and a monomethylated substrate peptide based on the N-terminus of histone H4. The results of initial velocity and product and dead-end inhibition experiments indicate that PRMT1 utilizes a rapid equilibrium random mechanism with the formation of dead-end EAP and EBQ complexes. This mechanism is gratifyingly consistent with previous results demonstrating that PRMT1 catalyzes substrate dimethylation in a partially processive manner. | 18,771,293 |
Viscosity and electrophoretic mobility of cesium fullerenehexamalonate in aqueous solutions--comparing experiments and theories on nanometer-sized spherical polyelectrolyte. | The viscosity of aqueous solutions of cesium fullerenehexamalonate T h -C 66(COOCs) 12, a rigid spherical nanometer-sized polyvalent salt, was measured by the Ubbelohde-type viscometer. The measurements were performed without added salt at 25 degrees C in the concentration range between 7 and 320 g/dm (3). THe concentration dependence of the obtained reduced viscosity was compared with the theoretical prediction, taking into account contributions stemming from the intrinsic viscosity, hydrodynamic perturbations of the hypothetically bare fullerenehexamalonate macroion, the primary electroviscous effect, and the secondary electroviscous effect. Using the geometric radius of the bare macroion from the previous measurements of the estimated effective charge of the macroion and from the small-angle X-ray scattering data of the estimated thickness of the compact shell of counterions electrostatically bound to the macroion, a good agreement between theory and the experiment was obtained in the range of the lowest and of the highest concentrations. Electrostatic interactions are identified as the main cause of the increased reduced viscosity at the lowest measured concentrations. At the highest concentrations, electrostatic interactions are effectively screened, and the influence of binary hydrodynamic interactions and perturbations of the hypothetical bare macroion prevails over electrostatic contributions to the increased viscosity. The electrophoretic mobility of the fullerenehexamalonate ion in aqueous salt-free medium was computed with the same value for the radius of the fullerenehexamalonate macroion as that used in the calculation of viscosity. The numerical solution of Ohshima's equation agreed well with the experimental values. | 18,771,306 |
Coupled deswelling of multiresponse microgels. | In this article, we study the response of a thermosensitive and ionic microgel to various external stimuli where coupling between different contributions to the total osmotic pressure is needed to describe the observations. We introduce a new Flory solvency parameter chi ( T, Q, n) with strong dependence on the network charge, Q, and salt concentration, n. The scaling exponent for the salt-induced deswelling of the microgel is the signature of the coupling between the mixing and ionic osmotic pressures. | 18,771,310 |
Functionalized polycarbonate derived from tartaric acid: enzymatic ring-opening polymerization of a seven-membered cyclic carbonate. | Enantiomerically pure functional polycarbonate was synthesized from a novel seven-membered cyclic carbonate monomer derived from naturally occurring L-tartaric acid. The monomer was synthesized in three steps and screened for polymerization with four commercially available lipases from different sources at 80 degrees C, in bulk. The ring-opening polymerization (ROP) was affected by the source of the enzyme; the highest number-average molecular weight, M(n) = 15500 g/mol (PDI = 1.7; [alpha]D(20) = +77.8, T(m) = 58.8 degrees C) optically active polycarbonate was obtained with lipase Novozyme-435. The relationship between monomer conversion, reaction time, molecular weight, and molecular weight distribution were investigated for Novozyme-435 catalyzed ROP. Deprotection of the ketal groups was achieved with minimal polymer chain cleavage (M(n) = 10000 g/mol, PDI = 2.0) and resulted in optically pure polycarbonate ([alpha]D(20) = +56) bearing hydroxy functional groups. Deprotected poly(ITC) shows T(m) of 60.2 degrees C and DeltaH(f) = 69.56 J/g and similar to that of the poly(ITC), a glass transition temperature was not found. The availability of the pendant hydroxyl group is expected to enhance the biodegradability of the polymer and serves in a variety of potential biomedical applications such as polymeric drug delivery systems. | 18,771,312 |
Novel textile chitosan scaffolds promote spreading, proliferation, and differentiation of osteoblasts. | Two novel scaffold models made of chitosan fibers were designed, fabricated, and investigated. Raw chitosan fibers were either tightened between plastic rings or were processed into stand-alone scaffolds. Chitosan fiber scaffolds were further modified by coating with a thin layer of fibrillar collagen type I to biologize the surface. Cell culture experiments were carried out using murine osteoblast-like cells (7F2). Confocal laser scanning microscopy (cLSM) as well as scanning electron microscopy (SEM) revealed fast attachment and morphological adaptation of the cells on both the raw chitosan fibers and the collagen-coated scaffolds. Cells were cultivated for up to 4 weeks on the materials and proliferation as well as osteogenic differentiation was quantitatively analyzed in terms of lactate dehydrogenase (LDH) and alkaline phosphatase (ALP) activity. We found a 14-16-fold increase of cell number and the typical pattern of ALP activity, whereas the collagen coating does not remarkably influence these parameters. The maintenance of osteogenic phenotype on the novel materials was furthermore confirmed by immunostaining of osteocalcin and study of matrix mineralization. The feature of the collagen-coated but also the raw chitosan fiber scaffolds to support the attachment, proliferation, and differentiation of osteoblast-like cells suggest a potential application of chitosan fibers and textile chitosan scaffolds for the tissue engineering of bone. | 18,771,318 |
Laser directed growth of carbon-based nanostructures by plasmon resonant chemical vapor deposition. | We exploit the strong plasmon resonance of gold nanoparticles in the catalytic decomposition of CO to grow various forms of carbonaceous materials. Irradiating gold nanoparticles in a CO environment at their plasmon resonant frequency generates high temperatures and strong electric fields required to break the CO bond. By varying the laser power, exposure time, and gas flow rate, we deposit amorphous carbon, graphitic carbon, and carbon nanotubes. The formation of iron oxide nanocrystals catalyzes the growth of carbon nanotubes. Predefined microstructure geometries are patterned by moving the focused laser spot during the growth process, forming suspended single-walled carbon nanotube structures. Raman spectroscopy, energy dispersive X-ray spectroscopy, and transmission electron microscopy are used to characterize the resulting material. The localized nature of the plasmonic heating enables growth of these materials, while the underlying substrate remains at room temperature. | 18,771,333 |
Tumor targeting by a multivalent single-chain Fv (scFv) anti-Lewis Y antibody construct. | The use of single-chain variable fragment (scFv) constructs has been investigated in cancer radioimmunotherapy (RIT) and radioimmunodetection, as these molecules permit rapid tumor penetration and clearance from the serum relative to whole IgG. Multimerization of scFv constructs has demonstrated improvements in functional affinity (i.e., avidity) and maximal tumor uptake. In this paper, we report the first biodistribution and pharmacokinetics studies of a noncovalent, direct-linked scFv (V(L)-0-V(H)) trimeric/tetrameric "multimer" of the anti-Lewis Y monoclonal antibody, hu3S193. The in vitro binding and in vivo biodistribution of the hu3S193 multimer was characterized alongside the hu3S193 F(ab')(2) following radiolabeling with the Indium-111 ((111)In) radioisotope. Immunoreactivities of the radiolabeled multimer and F(ab')(2) were 73% and 53.2%, and binding affinities (K(a)) were 1.58 x 10(7) M(1) and 4.31 x 10(6) M (1) for the multimer and F(ab')(2), respectively. Maximal tumor uptake in Le(y)-positive MCF-7 breast cancer xenografted BALB/c nude mice was 12.6 +/- 2.5 percent injected dose/per gram (%ID/g) at 6 hours postinjection for the multimer and 15.7 +/- 2.1 %ID/g at 24 hours postinjection for the F(ab')(2). However, limited in vitro stability and high renal localization of radiolabeled constructs were observed, which, despite the observed tumor targeting of the hu3S193 multimer, most likely preclude its use in RIT and imaging modalities. | 18,771,345 |
Increased expression of the tumor suppressor PLZF is a continuous predictor of long-term survival in malignant melanoma patients. | Promyelocytic leukemia zinc finger (PLZF) is a transcriptional repressor and tumor suppressor inhibiting melanoma cell growth in vitro and in vivo in animal models. In this study, we analyzed the impact of in vivo primary tumor gene expression of PLZF on the long-term survival of malignant melanoma patients. PLZF expression was assessed by using DNA microarray and real-time polymerase chain reaction analysis of 41 primary malignant melanomas from patients with a defined histology and a close to 20-year clinical follow-up, of 29 melanoma metastases, and of 6 different melanoma cell lines. Kaplan-Meier survival analyses, log-rank statistics and Cox regression analysis were employed to identify the impact of PLZF expression on long-term survival. We detected PLZF expression in 92% of primary melanoma tumors in vivo but not in melanoma cell lines in vitro. By univariate analysis, we identified: (1) PLZF mRNA expression < or = 10,000 mRNA copies/mug total tumor RNA, (2) Breslow tumor thickness >4 mm, and (3) American Joint Committee on Cancer stages IIC, IIIB, IIIC, and IV as statistically significant pretreatment risk factors. We defined a continuous prognostic index (i.e., risk score) for primary melanoma patients based on the regression coefficient of PLZF mRNA expression. Applying a cutpoint to the prognostic index at - 1.65, patients were assigned to one of two risk groups: low-risk patients (n = 28) with a median overall survival of 79 months (5-year survival of 61%) and high-risk patients (n = 13) with a median overall survival of 32 months (5-year survival of 23%) (p < 0.05). This is the first time that PLZF mRNA expression has been linked to a prognostic model for primary malignant melanoma patients to derive prognostic groups for clinical purposes (e.g., improved melanoma immunotherapies). | 18,771,349 |
Immunochemotherapy with PSK and fluoropyrimidines improves long-term prognosis for curatively resected colorectal cancer. | Long-term survival, which extends beyond 5 years, is a desired outcome for colorectal cancer patients. In the present study, we retrospectively compared the 10-year overall survival between the control group and the polysaccharide kureha (PSK) group and analyzed the factors influencing the prognosis. The control group was treated exclusively with oral fluoropyrimidines, whereas the PSK group was treated with fluoropyrimidines, given in conjunction with PSK for 24 months. The 10-year survival rates for the PSK group (81.9%) were significantly superior to those of the control group (50.6%). In Dukes' C cases, the 10-year overall survival rates for the PSK group were also significantly higher than those of the control group. In cases with lymphatic invasion graded ly2-ly3 or venous invasion graded v2-v3, the 10-year overall survival rates were 80.6% in the PSK group, which were significantly superior, compared to 25.9% in the control group. Analysis by Cox's proportional hazard model showed a significant difference between the control and PSK groups. These results indicate that postoperative adjuvant immunochemotherapy with PSK greatly improves prognosis at 10 years. On the basis of these results, we recommend postoperative adjuvant immunochemotherapy combined with PSK for patients with Dukes' C and in cases with ly2-ly3 or v2-v3 invasion. | 18,771,350 |
Modeling of trabecular bone and lamina dura following selective alveolar decortication in rats. | Modifying the balance between resorption and apposition through selectively injuring the cortical plate of the alveolus has been an approach to speed tooth movement and is referred to as periodontally accelerated osteogenic orthodontics. The aim of this study was to investigate the alveolar response to corticotomy as a function of time and proximity to the surgical injury in a rat model. Maxillary buccal and lingual cortical plates were injured in 36 healthy adult rats adjacent to the upper left first molars. Twenty-four animals were euthanized at 3, 7, or 11 weeks. In one group, the maxillae were removed and stripped of soft tissues, and histomorphometric analysis was performed to study alveolar spongiosa and periodontal ligament (PDL) modeling dynamics. Catabolic activity was analyzed with tartrate-resistant acid phosphatase-positive osteoclasts and preosteoclasts. Anabolic actions were measured using a fluorescent vital bone stain series followed by sacrifice at 30 and 51 days. To further analyze the new bone formation, a separate group of animals were fed with calcein fluorescent stain and processed for non-decalcified fluorescent stain histology. At 3 weeks, the surgery group had significantly (P <0.05) less calcified spongiosa bone surface, greater periodontal ligament surface, higher osteoclast number, and greater lamina dura apposition width. The catabolic activity (osteoclast count) and anabolic activity (apposition rate) were three-fold greater, calcified spongiosa decreased by two-fold, and PDL surface increased by two-fold. Surgical injury to the alveolus that induced a significant increase in tissue turnover by week 3 dissipated to a steady state by postoperative week 11. The impact of the injury was localized to the area immediately adjacent to the decortication injury. Selective alveolar decortication induced increased turnover of alveolar spongiosa, and the activity was localized; dramatic escalation of demineralization-remineralization dynamics is the likely biologic mechanism underlying rapid tooth movement following selective alveolar decortication. | 18,771,369 |
Collagenolytic fragments and active gelatinase complexes in periodontitis. | Periodontal tissues remodel rapidly, which enables quick adaptation to mechanical changes. Matrix metalloproteinases (MMPs) are involved in these remodeling processes under control of tissue inhibitor of metalloproteinases (TIMPs). In periodontitis, overactivity of MMPs results in pathologic tissue degradation. The aim of this study was to analyze MMPs and TIMPs in healthy and diseased gingiva, periodontal ligament (PDL), and gingival crevicular fluid (GCF). Samples of gingiva, PDL, and GCF were obtained from healthy controls (gingiva: n = 18; PDL: n = 15; GCF: n = 8) and subjects with periodontitis (gingiva: n = 11; PDL: n = 18; GCF: n = 12). MMPs and TIMPs were analyzed by gelatin-, collagen-, and reverse zymography and by Western blotting. Total MMP activity was analyzed using a fluorogenic substrate. TIMP-1 and -2, active and pro-MMP-2 and -9, and active MMP-1 and -8 were present in all samples. Large amounts of active MMP-2 complexes and collagenolytic fragments were also found. Their levels were higher in PDL and GCF from subjects with periodontitis. In general, TIMP levels were lower in diseased periodontal tissues. Especially diseased GCF contained more MMPs. Surprisingly, some MMPs were more abundant in healthy gingiva and PDL than in diseased tissue. Unexpected variations in MMP and TIMP levels in gingiva, PDL, and GCF may result from differences in subject characteristics and disease activity. The levels of active MMP-2 complexes and collagenolytic fragments are higher in the periodontium of subjects with periodontitis and might contribute significantly to periodontal destruction. | 18,771,372 |
Analysis of the occlusal stress transmitted to the inferior alveolar nerve by an osseointegrated threaded fixture. | Altered sensation can occur after the placement or loading of mandibular implants. Limited evidence exists with regard to the proper distance between the implant and the mandibular nerve to ensure the nerve's integrity and physiologic activity. The proper distance should come from evaluation of clinical data as well as from biomechanical analyses. A numeric mandibular model based on the boundary element method was created to simulate a mandibular segment containing a threaded fixture so that the pressure on the trigeminal nerve, as induced by the occlusal loads, could be assessed. Such pressure distributions were evaluated with different distances of the fixture from the mandibular canal and considering different bone densities. Although all simulations considered a canal that was orthogonal to the implant axis, in one case, the effects of an inclined canal were analyzed. The nerve pressure increased rapidly with a bone density decrease. A low mandibular cortical bone density caused a major nerve pressure increase. Our study suggested a distance of 1.5 mm to prevent implant damage to the underlying inferior alveolar nerve when biomechanical loading was taken into consideration. | 18,771,376 |
Clinical, histologic, and histomorphometric analyses of regenerated bone in maxillary sinus augmentation using fresh frozen human bone allografts. | The purpose of the present study was the clinical and the histologic evaluation of fresh frozen human bone (FFB) allografts used for maxillary sinus-augmentation procedures. Ten subjects were treated with maxillary sinus augmentations using FFB. Radiologic measurements were recorded on computed tomography scans preoperatively and 5 months after the sinus surgeries. At 5 months, during implant placement, 10 core biopsies were retrieved and processed for histomorphometric evaluation under light microscopy (LM). Clinical and histomorphometric measurements are presented as mean +/- SD. At baseline, the height of the alveolar ridge measured 4.3 +/- 1.3 mm (mean); after augmentation procedures, at implant positioning, it had a mean height of 16.0 +/- 1.8 mm. All 22 dental implants were clinically healthy after 5 months. LM showed that most of the specimens presented newly formed bone that was completely integrated with preexisting bone. The interface areas between new and old bone were not discernible. Woven bone was present in some areas of the biopsies; however, in the majority of the examined regions, there was mature osseous tissue presenting features of trabecular bone. There was no evidence of an acute inflammatory infiltrate. Histomorphometry revealed that the percentage of bone was 48.15% +/- 14.32%, whereas marrow spaces occupied the rest of the area. FFB is a biocompatible material that can be successfully used for maxillary sinus augmentations without interfering with normal reparative bone processes. | 18,771,383 |
What explains racial differences in the use of advance directives and attitudes toward hospice care? | Cultural beliefs and values are thought to account for differences between African Americans and whites in the use of advance directives and beliefs about hospice care, but few data clarify which beliefs and values explain these differences. Two hundred five adults aged 65 and older who received primary care in the Duke University Health System were surveyed. The survey included five scales: Hospice Beliefs and Attitudes, Preferences for Care, Spirituality, Healthcare System Distrust, and Beliefs About Dying and Advance Care Planning. African Americans were less likely than white subjects to have completed an advance directive (35.5% vs 67.4%, P<.001) and had less favorable beliefs about hospice care (Hospice Beliefs and Attitudes Scale score, P<.001). African Americans were more likely to express discomfort discussing death, want aggressive care at the end of life, have spiritual beliefs that conflict with the goals of palliative care, and distrust the healthcare system. In multivariate analyses, none of these factors alone completely explained racial differences in possession of an advance directive or beliefs about hospice care, but when all of these factors were combined, race was no longer a significant predictor of either of the two outcomes. These findings suggest that ethnicity is a marker of common cultural beliefs and values that, in combination, influence decision-making at the end of life. This study has implications for the design of healthcare delivery models and programs that provide culturally sensitive end-of-life care to a growing population of ethnically diverse older adults. | 18,771,455 |
Establishment and characterization of immortalized human gingival keratinocyte cell lines. | Primary human keratinocytes are used to analyze the properties of the oral epithelium and the early stages of oral bacterial infections. In vitro, these cells are characterized by their short life span and restricted availability. Approaches for culturing these cells will end after approximately 6-10 passages as a result of entry into apoptosis. For this reason, it is important to generate cell lines suitable for obtaining an unlimited source of cells. Therefore, the aim of the present study was to generate gingival keratinocyte cell lines and to compare their in vitro behaviour with those of primary human gingival keratinocytes. Primary human gingival keratinocytes were immortalized with a combination of the human papilloma virus onkoproteins E6 and E7. The pattern of the cytokeratins, involucrin and filaggrin was investigated by intracellular staining using flow cytometry. This method allows quantitative analysis of the expression of a variety of intracellular or extracellular markers. The immortalized cell lines showed many morphological similarities, expressing a cytokeratin pattern that is comparable with that of primary gingival keratinocytes. Furthermore, they developed transepithelial electrical resistance, which is a marker for the generation of tight junctions. These results indicate that the cells might be able to act as an epithelial barrier, reflecting the reaction of primary human cells. The establishment of a continuous line of human gingival epithelial cells with functional characteristics of the epithelial barrier provides a valuable in vitro model for using to study the early steps of gingival/periodontal infections. | 18,771,458 |
Negative affect and 24-hour ambulatory physiological recordings as predictors of spontaneous improvement of medically unexplained symptoms. | The predictive value for spontaneous improvement in individuals suffering from medically unexplained symptoms (MUS) was explored of (1) anxiety and depression obtained from questionnaires, (2) negative affective states obtained from experience-sampling, and (3) ambulatory-assessed real-life physiological recordings. Sixty-seven individuals with MUS and 61 healthy controls were included. Twenty-four hour ambulatory recordings of cardiac autonomic activity, respiration, end-tidal CO(2) and saliva cortisol were combined with experience-sampling of somatic complaints and mood. Complaints were assessed again after one year. Although a reduction in symptoms (25%) was found, this could not be predicted from initial anxiety and depression. Improvement was somewhat related to relatively low diary reports of fatigue, especially in the late-afternoon and evening (3% variance explained). From the physiological measures only relatively high PetCO(2) values in the morning predicted improvement (5% explained). It was concluded that spontaneous recovery from MUS is hard to predict from self-reported distress and ambulatory physiological recordings. | 18,771,476 |
Antinociceptive effect of a ruthenium complex in mice. | 1. The ruthenium complexes are important tools in inorganic chemistry. Different biological properties are found in the presence of distinct coordinate ligands, which offer a variety of potential clinical and pharmacological uses. 2. The aim of this work was to evaluate the antinociceptive and behavioural effects of the ruthenium complex, trans-[RuCl(2)(i-dinic)(4)]Cl, in mice. 3. The potential analgesic activity was tested using the formalin and hot plate tests and the behavioural effect was evaluated using the rotarod and spontaneous locomotor tests. The complex was administered at concentrations of 1.3, 4.5 and 18.0 mumol kg(-1) i.p. Morphine (6.0 mg kg(-1), i.p.) and diclofenac sodium (20.0 mg kg(-1), i.p.) were used as reference drugs. 4. The compound had no sedative activity on motor ataxia in the behavioural and analgesic tests. No significant effect was observed in the first phase of the formalin test, however, an effect was observed in the second phase. 5. The complex studied was probably more powerful than the reference drugs as an antinociceptive agent, as this mechanism also involved the nitric oxide (NO) pathway. From this perspective, further experimental studies will be useful to understand the effect of these compounds on NO and the relationship between prostaglandin and NO biosynthesis. | 18,771,479 |
HTR2A variation and sudden infant death syndrome: a case-control analysis. | The serotonergic (5-HT) system functions in central autonomic regulation with homeostatic roles in cardiorespiratory control, thermoregulation, arousal and sleep-wake cycling. Altered function and development of this system in cases of sudden infant death syndrome (SIDS) have been established, but the aetiology of these disturbances remains unclear. The serotonin receptor, HTR2A, functions within this system with roles in the homeostatic response to hypoxia including excitatory effects on respiration, gasping and rhythm generation, all functions potentially compromised in SIDS. The objective of this study was to examine the relationship between SIDS risk and HTR2A variation. All coding regions, intron-exon boundaries and the promoter region of HTR2A were PCR amplified and analysed by standard sequencing in 96 SIDS cases and 96 matched controls. Twenty-one HTR2A variations were identified in this case-control cohort, including four novel variations (c.C-1185A, c.T-923C, c.T-17C and c.C50T). None of the variations identified showed a significant association with SIDS. This report provides evidence that despite known alterations of the 5-HT system in SIDS, and the logical role for the HTR2A receptor, genetic variation of HTR2A as studied in our cohort is not responsible for these alterations. These results represent a further step in the investigation of the aetiology of the altered serotonin system in SIDS cases. | 18,771,483 |
Should children with a history of anaphylaxis to foods undergo challenge testing? | Data on the frequency of resolution of anaphylaxis to foods are not available, but such resolution is generally assumed to be rare. To determine whether the frequency of negative challenge tests in children with a history of anaphylaxis to foods is frequent enough to warrant challenge testing to re-evaluate the diagnosis of anaphylaxis, and to document the safety of this procedure. All children (n=441) who underwent a double-blind, placebo-controlled food challenge (DBPCFC) between January 2003 and March 2007 were screened for symptoms of anaphylaxis to food by history. Anaphylaxis was defined as symptoms and signs of cardiovascular instability, occurring within 2 h after ingestion of the suspected food. Twenty-one children were enrolled (median age 6.1 years, range 0.8-14.4). The median time interval between the most recent anaphylactic reaction and the DBPCFC was 4.25 years, range 0.3-12.8. Twenty-one DBPCFCs were performed in 21 children. Eighteen of 21 children were sensitized to the food in question. Six DBPCFCs were negative (29%): three for cows milk, one for egg, one for peanut, and one for wheat. In the positive DBPCFCs, no severe reactions occurred, and epinephrine administration was not required. This is the first study using DBPCFCs in a consecutive series of children with a history of anaphylaxis to foods, and no indications in dietary history that the food allergy had been resolved. Our study shows that in such children having specific IgE levels below established cut-off levels reported in other studies predicting positive challenge outcomes, re-evaluation of clinical reactivity to food by DBPCFC should be considered, even when there are no indications in history that anaphylaxis has resolved. DBPCFCs can be performed safely in these children, although there is a potential risk for severe reactions. | 18,771,485 |
An association of migraine with hereditary haemorrhagic telangiectasia independently of pulmonary right-to-left shunts. | Hereditary haemorrhagic telangiectasia (HHT) is a genetic disorder characterized by epistaxis, telangiectasia and visceral vascular manifestations. It is associated with migraine with aura due to pulmonary arteriovenous malformations (pAVMs). The aim of the study was to evaluate headache prevalence in 106 consecutive HHT patients (67 female, 39 male, age 53.5 +/- 14.5 years) and age- and gender-matched controls. An extensive clinical work-up was performed and headache prevalence was determined. Lifetime prevalence of migraine was higher in HHT patients (39.6%) than in controls (19.8%) [P < 0.001, chi(2) = 12.17, odds ratio (OR) 3.0; 95% confidence interval 1.6 < OR < 5.7]. A positive association was confirmed between HHT patients with pAVMs and migraine with aura (38.5% vs. 10%). Furthermore, HHT patients without pAVMs had a higher prevalence of migraine without aura (11.5% vs. 26.3%; chi(2) = 11.85; d.f. = 2; P = 0.003). We speculate that pathophysiological mechanisms, including dysfunction of the transforming growth factor-beta pathways and resulting vascular changes, contribute to the higher prevalence of migraine without aura in HHT patients without pAVMs. | 18,771,488 |
The link between pain patient and analgesic medication is greater in migraine than in rheumatic disease patients. | Our aim was to measure and compare the link between pain patients and the different kinds of analgesic medications they use by the Leeds Dependence Questionnaire (LDQ). This is a self-completion 10-item instrument to measure the severity of dependence upon a variety of substances. LDQ was administered to 200 episodic migraine patients (EM group), 77 chronic migraine patients (CM group) overusing acute medications, and 114 patients suffering from rheumatic disease (RD group), consecutively attending the Headache Centre or the Rheumatology Clinic of the University Hospital of Modena in the course of the first semester of 2007. The link with analgesics was greater in migraine patients than in patients with rheumatic disease, since the LDQ total score was significantly higher in the EM (6.65 +/- 0.32, P < 0.005) and CM groups (9.61 +/- 0.59, P < 0.0001) than in the RD group (5.17 +/- 0.37) (Kruskal-Wallis and Mann-Whitney U-tests). Migraine patients were significantly more linked to triptans and to combined medications than to non-steroidal anti-inflammatory drugs. The strength of the link between migraine patients and the analgesic medications they take could represent a factor of vulnerability: overusing these medications could develop medication overuse headache. | 18,771,492 |
Characterizing microbial diversity in production water from an Alaskan mesothermic petroleum reservoir with two independent molecular methods. | The phylogenetic diversity of Bacteria and Archaea within a biodegraded, mesothermic petroleum reservoir in the Schrader Bluff Formation of Alaska was examined by two culture-independent methods based on fosmid and small-subunit rRNA gene PCR clone libraries. Despite the exclusion of certain groups by each method, there was overall no significant qualitative difference in the diversity of phylotypes recovered by the two methods. The resident Bacteria belonged to at least 14 phylum-level lineages, including the polyphyletic Firmicutes, which accounted for 36.2% of all small-subunit rRNA gene-containing (SSU(+)) fosmid clones identified. Members of uncultured divisions were also numerous and made up 35.2% of the SSU(+) fosmid clones. Clones from domain Archaea accounted for about half of all SSU(+) fosmids, suggesting that their cell numbers were comparable to those of the Bacteria in this microbial community. In contrast to the Bacteria, however, nearly all archaeal clones recovered by both methods were related to methanogens, especially acetoclastic methanogens, while the plurality of bacterial fosmid clones was affiliated with Synergistes-like acetogenic Firmicutes that possibly degrade longer-chain carboxylic acid components in the crude oil to acetate. These data suggest that acetate may be a key intermediary metabolite in this subsurface anaerobic food chain, which leads to methane production as the primary terminal electron sink. | 18,771,500 |
Prevalence of Campylobacter jejuni and its resistance to antibiotics in poultry in the Czech Republic. | Thermotolerant Campylobacter spp., in particular Campylobacter jejuni, are among the most frequently identified pathogens, found to be causing human gastrointestinal infections in Europe, with the Czech Republic being no exception. The presented work aimed at assessing results of the first nationwide monitoring of prevalence and antibiotic resistance of Campylobacter spp. in broiler flocks in the Czech Republic, including a comparison of antibiotic resistance of C. jejuni isolates collected from poultry and the human community. The monitoring was carried out in poultry slaughterhouses in 2006 and 2007. From broilers, cloacal swabs were collected and examined. The human isolates of C. jejuni were acquired from rectal swabs in community patients with diarrhoeal diseases. Suspected isolates of both animal and human origin were confirmed by the PCR methods. Antibiotic resistance to selected anti-microbial agents was tested by the microdilution method. In the monitored period, the prevalence of thermotolerant Campylobacter spp. in broilers in the Czech Republic reached almost 50%. In 2006, C. jejuni was detected in 46% and Campylobacter coli in 3% of the tested samples. In 2007, C. jejuni was found in 43% and C. coli in 2% of the samples. The results of anti-microbial susceptibility testing of C. jejuni showed higher resistance in animals when compared with humans. The only exception was tetracycline with higher resistance in isolates of human origin. The highest resistance detected was to quinolone antibiotics. Resistance to oxolinic acid was 77% in animal and 60% in human isolates, to ciprofloxacin 72% in isolates from poultry and 55% in those from humans. In ampicillin, 26% of poultry isolates and 16% of human isolates were resistant. Moreover, 9% of animal isolates demonstrated resistance to streptomycin, undetected in human isolates. In erythromycin, resistance was found in 6% of poultry and 1% of human isolates. | 18,771,516 |
Treatment of advanced cervical cancer: a population-based study. | Chemoradiation is the standard treatment for locally advanced cervical cancer. We report how our population were treated over a 6-year period. Approximately 78.7% of all patients with advanced cervical cancer received chemoradiation, which appears to be well tolerated and acceptable to patients. | 18,771,538 |
Adjustment of L-T4 substitutive therapy in pregnant women with subclinical, overt or post-ablative hypothyroidism. | Maternal hyperthyrotropinaemia is associated with an increased risk of adverse maternal and neonatal outcomes. Physiological changes during pregnancy require an increased production of thyroid hormones (or an increase in daily substitutive doses of L-T4 in hypothyroid patients) to meet the maternal and foetal needs. The aim of the study was to evaluate variations of substitutive L-T4 doses that are able to maintain serum TSH between 0.5 and 2.5 mU/l in pregnant women with subclinical- (SH), overt- (OH) and post-ablative (PH) hypothyroidism. This was a retrospective study on hypothyroid pregnant women referred to the out-patient department between January 2004 and December 2006. A total of 185 pregnant women were studied during gestation; 155 patients (76 SH, 52 OH, 27 PH) were already on L-T4 before conception and 30 (SH) started L-T4 therapy during gestation. Thyroid function and body weight were evaluated every 4-6 weeks. In the group of patients already treated before conception, 134 (86.5%) increased L-T4 doses during gestation one or more times, eight (6%) reached a definitive therapeutic dosage within the 12th week of pregnancy, 64 (47.8%) within the 20th week and 62 (46.2%) within the 31st week. This initial L-T4 increase at the first evaluation during pregnancy was 22.9 +/- 9.8 microg/day. The final L-T4 doses were significantly different depending on the aetiology, being 101.0 +/- 24.6 microg/day in SH, 136.8 +/- 30.4 microg/day in OH and 159.0 +/- 24.6 microg/day in PH. The per cent increase of L-T4, expressed as Delta% of absolute dose, was +70% in SH, +45% in OH and +49% in PH as compared to baseline dose. In SH patients diagnosed during gestation, the starting L-T4 dose was higher than L-T4 dose before pregnancy of SH patients already treated (75.4 +/- 14.5 and 63.2 +/- 20.1 microg/day, respectively), whereas the final doses were similar. L-T4 dose was increased one or more times in 24 patients (80%), 8 reached the definitive dosage within the second trimester (33.3%) and 16 within the third trimester (66.7%). Serum TSH and FT4 measurements are mandatory in pregnant patients and the optimal timing for increasing L-T4 is the first trimester of pregnancy, though many patients require adjustments also during the second and third trimester. The aetiology of hypothyroidism influences the adjustment of L-T4 therapy and SH patients needed a larger increase than OH and PH. Close monitoring during pregnancy appears to be mandatory in hypothyroid women. | 18,771,569 |
Normalization of flow-mediated dilation to shear stress area under the curve eliminates the impact of variable hyperemic stimulus. | Normalization of brachial artery flow-mediated dilation (FMD) to individual shear stress area under the curve (peak FMD:SSAUC ratio) has recently been proposed as an approach to control for the large inter-subject variability in reactive hyperemia-induced shear stress; however, the adoption of this approach among researchers has been slow. The present study was designed to further examine the efficacy of FMD normalization to shear stress in reducing measurement variability. Five different magnitudes of reactive hyperemia-induced shear stress were applied to 20 healthy, physically active young adults (25.3 +/- 0. 6 yrs; 10 men, 10 women) by manipulating forearm cuff occlusion duration: 1, 2, 3, 4, and 5 min, in a randomized order. A venous blood draw was performed for determination of baseline whole blood viscosity and hematocrit. The magnitude of occlusion-induced forearm ischemia was quantified by dual-wavelength near-infrared spectrometry (NIRS). Brachial artery diameters and velocities were obtained via high-resolution ultrasound. The SSAUC was individually calculated for the duration of time-to-peak dilation. One-way repeated measures ANOVA demonstrated distinct magnitudes of occlusion-induced ischemia (volume and peak), hyperemic shear stress, and peak FMD responses (all p < 0.0001) across forearm occlusion durations. Differences in peak FMD were abolished when normalizing FMD to SSAUC (p = 0.785). Our data confirm that normalization of FMD to SSAUC eliminates the influences of variable shear stress and solidifies the utility of FMD:SSAUC ratio as an index of endothelial function. | 18,771,594 |
HIV risk practices sought by men who have sex with other men, and who use internet websites to identify potential sexual partners. | Men who have sex with men (MSM) account for the largest number of persons diagnosed with AIDS in the USA, with higher than average rates of drug use and unprotected sex being cited as the principal reasons underlying their high rates of HIV infection. Recent evidence has suggested that the use of websites specifically designed to promote unsafe sexual practices may be particularly common among MSM, thereby fostering their risky behaviours. In light of these findings, the present study is based on a content analysis of 1316 ads/profiles posted on one of the most popular MSM websites that specifically fosters unprotected sex. Ads/profiles were selected randomly based on the American ZIP code of residence. Data were collected between September 2006 and January 2007. Rates of advertised for high-risk sexual behaviours were very high, particularly for oral sex involving ejaculation into the mouth (88.0% for receptive oral sex, 77.4% for insertive oral sex), anal sex involving ejaculation into the anus (79.7% for insertive anal sex, 69.4% for receptive anal sex), multiple partner sex (77.9%) and felching (16.5%). A multivariate analysis of the correlates of sexual risk preferences identified seven factors that were related to a propensity towards enhanced sexual risk: younger age (beta = 0.12, P = 0.0001), not being African American (beta = 0.05, P = 0.0341), self-identification as a sexual 'bottom' (beta = 0.20, P = 0.0001), not caring about one's potential sex partners' HIV serostatus (beta = 0.15, P = 0.0001), preferring to have sex while under the influence of drugs (beta = 0.08, P = 0.0022), a greater involvement in and commitment to the use of the website to locate potential unprotected sex partners (beta = 0.16, P = 0.0001) and not being HIV-negative (beta = 0.08, P = 0.0081). The HIV intervention-related implications of these findings are discussed. | 18,771,639 |
A method for detecting microfilaraemia, filarial specific antigens and antibodies and typing of parasites for drug resistance and genotypes using finger prick blood sample. | Monitoring and evaluation of programme to eliminate lymphatic filariasis (LF) depends on epidemiological assessment using appropriate indicators. Minimum efforts using reliable tests are necessary to guide the programme managers in decision-making. Impact of Mass Drug Administration (MDA) towards filariasis elimination can be assessed by the detection of microfilariae (mf) or parasite DNA (infective), filarial antigens (infected) and antibodies (exposure). It is also important to monitor drug resistance and variation in genetic structure of parasite populations using molecular markers. We developed a method to carry out parasitological, molecular, immunological and genetic analysis from a minimum volume of blood sample (about 150 microl) drawn from finger tip of an individual residing in LF endemic area. The method involves separation of sera for immunological assays and isolation of mf of Wuchereria bancrofti from the blood clots for counting, which were then used for W. bancrofti specific PCR, screening for albendazole sensitivity/resistance alleles by AS-PCR, RAPD profiling and ITS 2 PCR for genotyping. A protocol is also suggested for the separation of sera for assays to detect antigen and antibodies and isolation of mf from clots for genetic analysis. The protocol developed has shown potential application in monitoring several immunological, parasitological and molecular parameters from a limited amount of blood sample collected by finger prick, in large-scale operations. | 18,771,650 |
Crystal structure of chondroitin polymerase from Escherichia coli K4. | Elongation of glycosaminoglycan chains, such as heparan and chondroitin, is catalyzed by bi-functional glycosyltransferases, for which both 3-dimensional structures and reaction mechanisms remain unknown. The bacterial chondroitin polymerase K4CP catalyzes elongation of the chondroitin chain by alternatively transferring the GlcUA and GalNAc moiety from UDP-GlcUA and UDP-GalNAc to the non-reducing ends of the chondroitin chain. Here, we have determined the crystal structure of K4CP in the presence of UDP and UDP-GalNAc as well as with UDP and UDP-GlcUA. The structures consisted of two GT-A fold domains in which the two active sites were 60A apart. UDP-GalNAc and UDP-GlcUA were found at the active sites of the N-terminal and C-terminal domains, respectively. The present K4CP structures have provided the structural basis for further investigating the molecular mechanism of biosynthesis of chondroitin chain. | 18,771,653 |
The role of 15-deoxy-delta(12,14)-prostaglandin J(2), an endogenous ligand of peroxisome proliferator-activated receptor gamma, in tumor angiogenesis. | Peroxisome proliferator-activated receptor gamma (PPARgamma), a nuclear hormone receptor, is a ligand-activated transcription factor involved in adipogenesis, glucose homeostasis and lipid metabolism. 15-Deoxy-Delta(12,14)-prostaglandin J(2) (15d-PGJ(2)), an endogenous ligand of PPARgamma, has multifaceted cellular functions. Angiogenesis plays an important role in the pathophysiology of ischemic and neoplastic disorders, especially cancer. 15d-PGJ(2) is involved in regulation of angiogenic mediators including vascular endothelial growth factor and hence participates in the blood vessel formation by means of angiogenesis. However, depending on the experimental conditions, this cyclopentenone prostaglandin can exert opposite effects on angiogenesis. 15d-PGJ(2) inhibits angiogenesis via suppression of pro-inflammatory enzymes and cytokines, while it also stimulates angiogenesis via induction of heme oxygenase-1, endothelial nitric-oxide synthase, and hypoxia inducible factor-1alpha. The aim of this review is to highlight such dual effects of 15d-PGJ(2) on angiogenesis and underlying molecular mechanisms. | 18,771,658 |
Clinical practice of rTMS reveals a functional dissociation between agency and hallucinations in schizophrenia. | We report here the case of a hospitalized 11 year-old boy (YP) with a positive diagnosis of 'Childhood Onset Schizophrenia'. YP experienced verbal-auditory hallucinations, a delusion of alien control and hetero-aggressive behaviour. Antipsychotic drugs were unsuccessful and furthermore provoked severe acute dystonia. fMRI-guided rTMS applied over several cortical regions provided the means to reveal for the first time a functional dissociation between auditory-verbal hallucinations and agency. These results demonstrate the efficacy of rTMS for young patients suffering from drug-resistant hallucinations but they furthermore question the physiopathology of the hallucinatory process by suggesting that agency and hallucinations may be sub-served by different neural networks. | 18,771,675 |
Random number generation in neglect patients reveals enhanced response stereotypy, but no neglect in number space. | Based on interactions between number and space apparent from healthy subjects' randomization attempts we expected random number generation (RNG) to be sensitive for the monitoring of unilateral spatial deficits. Specifically, we predicted patients with left-sided hemineglect to evidence "neglect in number space", i.e. to produce a deficiency in the generation of small, "left-sided" numbers. In RNG of digits from 1 to 6, 19 patients with left-sided neglect generated sequences with a higher redundancy, but as many small numbers as did a matched control group. We discuss possible reasons for the absence of a small-number neglect and emphasize that the observed redundancy was not due to a counting bias, as known from other neurological patients, but to an unspecific imbalance in the use of response alternatives. We speculate that this may be the consequence of disrupted fronto-parietal functions normally serving in the sequential organization and manipulation of items in working memory. | 18,771,676 |
Reciprocal regulation of extracellular signal regulated kinase 1/2 and mitogen activated protein kinase phosphatase-3. | Mitogen activated protein kinase phosphatase-3 (MKP-3) is a putative tumor suppressor. When transiently overexpressed, MKP-3 dephosphorylates and inactivates extracellular signal regulated kinase (ERK) 1/2. Little is known about the roles of endogenous MKP-3, however. We previously showed that MKP-3 is upregulated in cell lines that express oncogenic Ras. Here we tested the roles of endogenous MKP-3 in modulating ERK1/2 under conditions of chronic stimulation of the Ras/Raf/MEK1/2/ERK1/2 pathway by expression of oncogenic Ras. We used two cell lines: H-ras MCF10A, breast epithelial cells engineered to express H-Ras, and DLD-1, colon cancer cells that express endogenous Ki-Ras. First, we found that MKP-3 acts in a negative feedback loop to suppress basal ERK1/2 when oncogenic Ras stimulates the Ras/Raf/MEK1/2/ERK1/2 cascade. ERK1/2 was required to maintain elevated MKP-3, indicative of a negative feedback loop. Accordingly, knockdown of MKP-3, via siRNA, increased ERK1/2 phosphorylation. Second, by using siRNA, we found that MKP-3 helps establish the sensitivity of ERK1/2 to extracellular activators by limiting the duration of ERK1/2 phosphorylation. Third, we found that the regulation of ERK1/2 by MKP-3 is countered by the complex regulation of MKP-3 by ERK1/2. Potent ERK1/2 activators stimulated the loss of MKP-3 within 30 min due to an ERK1/2-dependent decrease in MKP-3 protein stability. MKP-3 levels recovered within 120 min due to ERK1/2-dependent resynthesis. Preventing MKP-3 resynthesis, via siRNA, prolonged ERK1/2 phosphorylation. Altogether, these results suggest that under the pressure of oncogenic Ras expression, MKP-3 reins in ERK1/2 by serving in ERK1/2-dependent negative feedback pathways. | 18,771,677 |
Long-term effects of prenatal stress: changes in adult cardiovascular regulation and sensitivity to stress. | Prenatal environment exerts profound influences on the development of an organism and stressful events during pregnancy can bring about long-term physiological/behavioral alterations in the offspring. Epidemiological evidence points to a relationship between intrauterine growth restriction (IUGR), body weight at birth, and adult cardiovascular disease. Experimental research employed different models of IUGR, including altered maternal nutrition, exposure to elevated glucocorticoids, and reduced placental perfusion, all of which can program, when acting during sensitive temporal windows of foetal life, alterations in cardiovascular regulation and stress sensitivity. Original data are presented indicating that prenatal psychological stress (intermittent restraint) does not induce in the rat adult offspring changes of plasma corticosterone levels, cardiac autonomic modulation, and circadian rhythmicity of heart rate (HR), body temperature (T) and physical activity (Act) at rest. However, prenatally stressed rats--when further stimulated in adulthood--exhibit prolonged adrenocortical stress responsivity, disturbed circadian rhythmicity of HR, T, and Act, and increased adrenal weight. This evidence supports the idea that prenatal stress per se does not change dramatically a given structure or function, but it affects resilience and renders the animal more susceptible to pathophysiological outcomes when further insults occur during adulthood. | 18,771,688 |
Detection of human survival motor neuron (SMN) protein in mice containing the SMN2 transgene: applicability to preclinical therapy development for spinal muscular atrophy. | Spinal muscular atrophy (SMA), the leading genetic cause of infant death results from loss of spinal motor neurons causing atrophy of skeletal muscle. SMA is caused by loss of the Survival Motor Neuron 1 (SMN1) gene, however, an identically coding gene called SMN2 is retained, but is alternatively spliced to produce approximately 90% truncated protein. Most SMA translational and preclinical drug development has relied on the use of SMA mice to determine changes in SMN protein levels. However, the SMA mouse models are relatively severe and analysis of SMN-inducing compounds is confounded by the early mortality of these animals. An antibody that could detect SMN protein on a Smn background could circumvent this limitation and allow unaffected, heterozygous animals to be examined. Here we describe the generation and characterization of a monoclonal anti-SMN antibody, 4F11, which specifically recognizes human SMN protein. 4F11 detects SMN (human) but not native Smn (mouse) protein in SMN2 transgenic mice and in SMA cell lines. We demonstrate the feasibility of using 4F11 to detect changes in SMN2-derived SMN protein in SMA patient fibroblasts and in healthy SMN2 transgenic mice. This antibody is, therefore, an excellent tool for examining SMN2-inducing therapeutics in patient cells as well as in transgenic mice. | 18,771,690 |
The effect of simultaneous contractions of ipsilateral muscles on changes in corticospinal excitability induced by paired associative stimulation (PAS). | Consideration was given to means of increasing the reliability and muscle specificity of paired associative stimulation (PAS) by utilising the phenomenon of crossed-facilitation. Eight participants completed three separate sessions: isometric flexor contractions of the left wrist at 20% of maximum voluntary contraction (MVC) simultaneously with PAS (20s intervals; 14 min duration) delivered at the right median nerve and left primary motor cortex (M1); isometric contractions at 20% of MVC; and PAS only (14 min). Eight further participants completed two sessions of longer duration PAS (28 min): either alone or in conjunction with flexion contractions of the left wrist. Thirty motor potentials (MEPs) were evoked in the right flexor (rFCR) and extensor (rECR) carpi radialis muscles by magnetic stimulation of left M1 prior to the interventions, immediately post-intervention, and 10 min post-intervention. Both 14 and 28 min of combined PAS and (left wrist flexion) contractions resulted in reliable increases in rFCR MEP amplitude, which were not present in rECR. In the PAS only conditions, 14 min of stimulation gave rise to unreliable increases in MEP amplitudes in rFCR and rECR, whereas 28 min of PAS induced small (unreliable) changes only for rFCR. These results support the conclusion that changes in the excitability of the corticospinal pathway induced by PAS interact with those associated with contraction of the muscles ipsilateral to the site of cortical stimulation. Furthermore, focal contractions applied by the opposite limb increase the extent and muscle specificity of the induced changes in excitability associated with PAS. | 18,771,706 |
Astrocyte response to Junín virus infection. | In a previous study of experimental murine encephalitis induced by Junín virus (JV), an arenavirus, we showed increased expression of iNOS by unidentified cells, concomitant with the astrocyte reaction. The specific inhibition of iNOS was associated with greater mortality but lower astrocytosis, suggesting that the protective role of nitric oxide (NO) synthesized by iNOS was related to enhanced astrocyte activation, representing a beneficial cellular response to virus-induced central nervous system damage. In the present work, cultured astrocytes were used to study whether JV infection could trigger iNOS expression and assess its eventual relationship with viral replication, glial fibrilary acidic protein (GFAP) expression levels and the presence of apoptosis. We found that JV infection of astrocytes did not induce apoptosis but produced both increased iNOS synthesis, detected by immunocytochemistry and fluorescence activated cell sorting (FACS) analysis, and increased NO, which was indirectly measured by nitrite/nitrate levels. These changes occurred early relative to the increases in GFAP expression, as detected by immunocytochemistry, FACS analysis and RT-PCR. The fact that iNOS inhibition abolished enhanced GFAP expression in infected monolayers suggests that NO was directly involved. In addition, iNOS inhibition enhanced virus replication. Together with data from confocal microscopy, these results suggest that JV induces iNOS expression in infected astrocytes and that the resulting NO has an important role both in reducing viral replication and in enhancing subsequent astrocyte activation. | 18,771,707 |
Differential expression of phosphorylated Ca2+/calmodulin-dependent protein kinase II and phosphorylated extracellular signal-regulated protein in the mouse hippocampus induced by various nociceptive stimuli. | In the present study, we characterized differential expressions of phosphorylated Ca(2+)/calmodulin-dependent protein kinase IIalpha (pCaMKIIalpha) and phosphorylated extracellular signal-regulated protein (pERK) in the mouse hippocampus induced by various nociceptive stimuli. In an immunoblot study, s.c. injection of formalin and intrathecal (i.t.) injections of glutamate, tumor necrosis factor-alpha (TNF-alpha), and interleukin-1beta (IL-1 beta) significantly increased pCaMKIIalpha expression in the hippocampus, but i.p. injections of acetic acid did not. pERK1/2 expression was also increased by i.t. injection of glutamate, TNF-alpha, and IL-1beta but not by s.c. injections of formalin or i.p. injections of acetic acid. In an immunohistochemical study, we found that increased pCaMKIIalpha and pERK expressions were mainly located at CA3 or the dentate gyrus of the hippocampus. In a behavioral study, we assessed the effects of PD98059 (a MEK 1/2 inhibitor) and KN-93 (a CaMKII inhibitor) following i.c.v. administration on the nociceptive behaviors induced by i.t. injections of glutamate, pro-inflammatory cytokines (TNF-alpha or IL-1beta), and i.p. injections of acetic acid. PD98059 as well as KN-93 significantly attenuated the nociceptive behavior induced by glutamate, pro-inflammatory cytokines, and acetic acid. Our results suggest that (1) pERKalpha and pCaMK-II located in the hippocampus are important regulators during the nociceptive processes induced by s.c. formalin, i.t. glutamate, i.t. pro-inflammatory cytokines, and i.p. acetic acid injection, respectively, and (2) the alteration of pERK and pCaMKIIalpha in nociceptive processing induced by formalin, glutamate, pro-inflammatory cytokines and acetic acid was modulated in a different manner. | 18,771,711 |
DHEA levels and social dominance relationships in wintering brent geese (Branta bernicla bernicla). | After testosterone, dehydroepiandrosterone (DHEA) is the main hormone involved in aggressive behaviour in birds. While the role of DHEA has been verified for wintering territorial passerines, it has not been shown for gregarious species. In wintering geese species, both sexes present very low testosterone levels and aggression in a non-sexual context is not testosterone-related. Therefore, testosterone does not seem to be responsible for aggressive behaviour by geese during winter and the role of DHEA must be explored. We used brent geese (Branta bernicla bernicla) to examine the roles of testosterone and DHEA in dominance relationships. For the first time, we highlighted the presence of plasma DHEA in free-living geese. As the level of DHEA was lower than that of testosterone, and there was no obvious impact of DHEA level on dominance status, our results failed to confirm the role of plasma DHEA in the social hierarchies of this species during winter. Nevertheless, because DHEA levels were greater in singletons than in paired birds, we discuss the need to explore hormonal and/or behavioural mechanisms implicated within dominance status acquisition and maintenance within each reproductive status class, to underline the role of the presence of relatives as a signal of dominance abilities. We also acknowledge and discuss the possibility that the long handling time may have affected DHEA levels and masked subtle differences between individuals. | 18,771,715 |
Tunneling response of termites to a pre-formed tunnel. | Subterranean termites move from place to place while foraging by tunneling through soil. During a period of foraging, they are likely to encounter a number of pre-formed tunnels created by, for example, tree roots or the breaking up of a zone of hard or compacted soil. We systematically observed the behavioral response of tunneling termites to such pre-formed, artificially constructed tunnels at widths, W, of 0.5, 1.0, 1.5, and 2.0mm, which mimicked pre-formed tunnels in the field. The two tunnels intersected at an angle, theta (=0 degrees , 10 degrees , 20 degrees , 30 degrees , 40 degrees , 50 degrees , and 60 degrees ) formed between the advance direction of a termite tunnel and the perpendicular direction of a pre-formed tunnel. For W=Wc (=0.5mm) and theta<or=theta c (=30 degrees ), the tunneling termites penetrated the pre-formed tunnel, whereas for all other combinations of W and theta investigated, the termite tunnel merged with the pre-formed tunnel. The implications of these findings are briefly discussed in relation to the minimum size of surface indentation that termites can recognize as a cue to tunnel. | 18,771,716 |
Rsp5p ubiquitin ligase and the transcriptional activators Spt23p and Mga2p are involved in co-regulation of biosynthesis of end products of the mevalonate pathway and triacylglycerol in yeast Saccharomyces cerevisiae. | Rsp5p, a yeast S. cerevisiae ubiquitin ligase, is essential for regulation of unsaturated fatty acid synthesis via activation of the transcriptional activators Spt23p and Mga2p. Here we show that the conditional mutant rsp5-19 produces decreased levels of the end products of mevalonate pathway, such as ergosterol, ubiquinone and of dolichols, especially those with 19-24 isoprene units. The mechanism of Rsp5p involvement in the control of these lipid synthesis pathways was addressed by overproduction of Rsp5p-independent Spt23p or Mga2p. Expression of constitutively active forms of these transactivators resulted in excess production of ergosterol, but did not restore a wild-type level of dolichols. Moreover, synthesis of long chain dolichols was decreased in the wild-type and a rsp5-19 background. Finally, overproduction of active Spt23p or Mga2p was accompanied by the appearance of large lipid particles in the wild-type and rsp5-19 strains as observed by Nile Red staining, due to accumulation of unsaturated triacylglycerol. Thus, we conclude that Rsp5p, Spt23p and Mga2p may participate in the control of the homeostasis of lipids and lipid particles. | 18,771,750 |
FASTKD2 nonsense mutation in an infantile mitochondrial encephalomyopathy associated with cytochrome c oxidase deficiency. | In two siblings we found a mitochondrial encephalomyopathy, characterized by developmental delay, hemiplegia, convulsions, asymmetrical brain atrophy, and low cytochrome c oxidase (COX) activity in skeletal muscle. The disease locus was identified on chromosome 2 by homozygosity mapping; candidate genes were prioritized for their known or predicted mitochondrial localization and then sequenced in probands and controls. A homozygous nonsense mutation in the KIAA0971 gene segregated with the disease in the proband family. The corresponding protein is known as fas activated serine-threonine kinase domain 2, FASTKD2. Confocal immunofluorescence colocalized a tagged recombinant FASTKD2 protein with mitochondrial markers, and membrane-potential-dependent in vitro mitochondrial import was demonstrated in isolated mitochondria. In staurosporine-induced-apoptosis experiments, decreased nuclear fragmentation was detected in treated mutant versus control fibroblasts. In conclusion, we found a loss-of-function mutation in a gene segregating with a peculiar mitochondrial encephalomyopathy associated with COX deficiency in skeletal muscle. The corresponding protein is localized in the mitochondrial inner compartment. Preliminary data indicate that FASTKD2 plays a role in mitochondrial apoptosis. | 18,771,761 |
Investigation of retention behavior of drug molecules in supercritical fluid chromatography using linear solvation energy relationships. | In this study, the retention behaviors of pharmaceutical and drug-like compounds in supercritical fluid chromatography (SFC) with polar stationary phases were evaluated using linear solvation energy relationships (LSERs). We used more than 200 compounds, including mono-, di-substituted benzenes, and other marketed drugs with a wide range of solvation descriptors. The dominant contribution to positive retention was the hydrogen bond donor acidity of the solutes, particularly for pyridine and amino columns. That factor is determined by the difference in basicity between the mobile and stationary phases. Another significant contributor to retention behavior was the hydrogen bond acceptor basicity of the solutes made particularly for diol and amino columns. The hydrogen bond donating ability is small for cyano and pyridine stationary phases (or should be zero) since those two phases lack hydrogen bond donor groups. The LSER results showed that the SFC retention behavior of compounds using carbon dioxide-methanol with polar stationary phases was close to that reported for normal phase LC using hexane-methanol. As expected, mobile phases containing high percentages of modifier resulted in decreased retention times for most compounds. A greater knowledge of the nature of solute/stationary phase and solute/mobile phase allows a more rapid and efficient choice in high-throughput screening of compound libraries. | 18,771,773 |
Thermodynamics and bending energetics of toruslike micelles. | The self-assembly of surfactants forming toruslike or toroidal micelles has been investigated from a theoretical point of view, in particular the structural behaviour and stability of tori in terms of the three bending elasticity constants spontaneous curvature (H(0)), bending rigidity (k(c)) and saddle-splay constant (k(c)). It is demonstrated that the size of toruslike micelles increases with an increasing bending rigidity, but is independent of both spontaneous curvature and saddle-splay constant. Similar to conventional micelles, toruslike micelles are found to be stable over bilayers as the spontaneous curvature times the surfactant layer thickness exceeds 1/4. Moreover, it is shown that toruslike micelles, in general, are favoured at the expense of long spherocylindrical micelles as a result of elimination of the unfavourable end-caps. However, conventional micelles that are able to grow with respect to both width and length (tablets) may be stable over tori as well as spheres in much wider regimes of different bending elasticity constants. As a result, toruslike micelles are predicted to be stable over conventional micelles, including rods, at large values of the effective bending constant k(eff) identical with 2k(c)+k(c), i.e. in the same region where infinite cylinders are expected to be observed. This result is consistent with the fact that toruslike micelles have usually been observed to coexist with large networks of branched cylinders. | 18,771,780 |
IT3F: a web-based tool for functional analysis of transcription factors in plants. | A web-based tool, the Interspecies Transcription Factor Function Finder (IT3F), has been developed to display both evolutionary gene relationships and expression data for plant transcription factors, focussing primarily on the R2R3MYB gene subfamily for proof of concept. The graphical display of information allows users to make direct comparisons between structurally related genes and to identify those genes that are potentially orthologous, thereby assisting with their understanding of gene function. A key feature of the website is the provision of an interrogative phylogenetic tree that allows submission of new sequences corresponding to a transcription factor family or subfamily and maps their relative positions to the products of other genes on an 'existing' tree containing proteins encoded by Arabidopsis and rice genes, along with key proteins encoded by genes from other species that have been characterised functionally. In addition, a feature to select clusters of related sequences has been developed so that more detailed phylogenetic analysis can be performed to highlight potential orthologous and paralogous genes within related clusters. Arabidopsis genes that reside on duplicated regions of the genome are indicated on the tree, providing further information for interpreting gene function. An additional feature of the website allows a selected number of key Arabidopsis and rice microarray experiments to be visualised alongside the tree as a tabulated heat map of expression intensity values. Through this display, it is possible to observe relative expression levels across a whole gene family and the extent to which the expression of closely related genes within subgroups has altered since their ancestral divergence. The website is available at http://jicbio.nbi.ac.uk/IT3F/. | 18,771,782 |
3D-QSAR studies of boron-containing dipeptides as proteasome inhibitors with CoMFA and CoMSIA methods. | Three-dimensional quantitative structure-activity relationship (3D-QSAR) studies were performed for a series of dipeptide boronate proteasome inhibitors using comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) techniques. A training set containing 46 molecules served to establish the models. The optimum CoMFA and CoMSIA models obtained for the training set were all statistically significant with cross-validated coefficients (q(2)) of 0.676 and 0.630 and conventional coefficients (r(2)) of 0.989 and 0.956, respectively. The predictive capacities of both models were successfully validated by calculating a test set of 13 molecules that were not included in the training set. The predicted correlation coefficients (r(2)(pred)) of CoMFA and CoMSIA are 0.963 and 0.919, respectively. The CoMFA and CoMSIA field contour maps agree well with the structural characteristics of the binding pocket of beta5 subunit of 20S proteasome, which suggests that the 3D-QSAR models constructed in this paper can be used to guide the development of novel dipeptide boronate inhibitors of 20S proteasome. | 18,771,818 |
Estimation of the impact of prevailing weather conditions on the occurrence of oil-contaminated dead birds on the German North Sea coast. | Chronic oil pollution by illegal oil dumping in the North Sea is difficult to quantify. Beached, oil-contaminated sea birds, however, may be used as an indirect indicator. Reconstructing the drift of oil slicks and sea bird corpses in the southern North Sea for the period 1992-2003 by means of a two-dimensional numerical transport model driven by re-analysed weather data, we show with an example of two common sea bird species that the variability observed within the number of corpses registered during beached bird surveys for the German coast primarily reflects the inter-annual variability of prevailing weather conditions. This should be taken into account when interpreting the data. We propose normalisation of beached bird survey data based on numerical drift simulations to improve the recognition of trends in the level of chronic oil pollution. | 18,771,830 |
Paternal age and twinning in the Jerusalem Perinatal Study. | To investigate whether incidence of twin deliveries is related to father's age, independently of mother's age, and whether it differs for same-sex or opposite-sex twin sets. In a program of research on effects of paternal age, this study used data from a prospective cohort of 92,408 offspring born in Jerusalem from 1964 to 1976. Of the 91,253 deliveries in the Jerusalem Perinatal Study, 1115 were twin deliveries. The data were analyzed with General Estimate Equations to inform unconditional logistic regression. After controlling for maternal age, odds ratios (ORs) and 95% confidence intervals (95% CI) associated with father's ages 25-34 and 35+ were 1.3 (1.1, 1.7) and 1.5 (1.2, 2.1) respectively, compared with fathers <25 years old. The effect of maternal age was partly explained by paternal age. The ORs for opposite-sex twin sets and male-male twin sets increased slightly with paternal age, while the OR for same-sex and female-female twin decreased. Studies of twins are used to estimate effects of genes and environment in a variety of diseases. Our findings highlight the need to consider paternal as well as maternal age when analyzing data on twins to explore etiology of diseases. | 18,771,839 |
Mannheimia haemolytica serotype A1 exhibits differential pathogenicity in two related species, Ovis canadensis and Ovis aries. | Mannheimia haemolytica causes pneumonia in both bighorn sheep (BHS, Ovis canadensis) and domestic sheep (DS, Ovis aries). Under experimental conditions, co-pasturing of BHS and DS results in fatal pneumonia in BHS. It is conceivable that certain serotypes of M. haemolytica carried by DS are non-pathogenic to them, but lethal for BHS. M. haemolytica serotypes A1 and A2 are carried by DS in the nasopharynx. However, it is the serotype A2 that predominantly causes pneumonia in DS. The objectives of this study were to determine whether serotype A1 exhibits differential pathogenicity to BHS and DS, and to determine whether leukotoxin (Lkt) secreted by this organism is its primary virulence factor. Three groups each of BHS and DS were intra-tracheally administered either 1 x 10(9)cfu of serotype A1 wild-type (lktA-Wt group), Lkt-deletion mutant of serotype A1-(lktA-Mt group), or saline (control group), respectively. In the lktA-Wt groups, all four BHS died within 48h while none of the DS died during the 2-week study period. In the lktA-Mt groups, none of the BHS or DS died. In the control groups, one DS died due to an unrelated cause. Necropsy and histopathological findings revealed that death of BHS in the lktA-Wt group was due to bilateral, fibrinohemorrhagic pneumonia. Although the A1-Mt-inoculated BHS were clinically normal, on necropsy, lungs of two BHS showed varying degrees of mild chronic pneumonia. These results indicate that M. haemolytica serotype A1 is non-pathogenic to DS, but highly lethal to BHS, and that Lkt is the primary virulence factor of M. haemolytica. | 18,771,862 |
Standardization and validation of an induced ovulation model system in buffalo cows: Characterization of gene expression changes in the periovulatory follicle. | In bovines characterization of biochemical and molecular determinants of the dominant follicle before and during different time intervals after gonadotrophin surge requires precise identification of the dominant follicle from a follicular wave. The objectives of the present study were to standardize an experimental model in buffalo cows for accurately identifying the dominant follicle of the first wave of follicular growth and characterize changes in follicular fluid hormone concentrations as well as expression patterns of various genes associated with the process of ovulation. From the day of estrus (day 0), animals were subjected to blood sampling and ultrasonography for monitoring circulating progesterone levels and follicular growth. On day 7 of the cycle, animals were administered a PGF(2alpha) analogue (Tiaprost Trometamol, 750 microg i.m.) followed by an injection of hCG (2000 IU i.m.) 36 h later. Circulating progesterone levels progressively increased from day 1 of the cycle to 2.26+/-0.17 ng/ml on day 7 of the cycle, but declined significantly after PGF(2alpha) injection. A progressive increase in the size of the dominant follicle was observed by ultrasonography. The follicular fluid estradiol and progesterone concentrations in the dominant follicle were 600+/-16.7 and 38+/-7.6 ng/ml, respectively, before hCG injection and the concentration of estradiol decreased to 125.8+/-25.26 ng/ml, but concentration of progesterone increased to 195+/-24.6 ng/ml, 24h post-hCG injection. Inh-alpha and Cyp19A1 expressions in granulosa cells were maximal in the dominant follicle and declined in response to hCG treatment. Progesterone receptor, oxytocin and cycloxygenase-2 expressions in granulosa cells, regarded as markers of ovulation, were maximal at 24h post-hCG. The expressions of genes belonging to the super family of proteases were also examined; Cathepsin L expression decreased, while ADAMTS 3 and 5 expressions increased 24h post-hCG treatment. The results of the current study indicate that sequential treatments of PGF(2alpha) and hCG during early estrous cycle in the buffalo cow leads to follicular growth that culminates in ovulation. The model system reported in the present study would be valuable for examining temporo-spatial changes in the periovulatory follicle immediately before and after the onset of gonadotrophin surge. | 18,771,864 |
[Emerging viral infections in South East Asia and the Pacific region]. | The epidemiology of several viral diseases underwent profound changes in South-East Asia and Oceania over the past decades. This was due to several factors, including the geographical distribution of vectors and the viruses they transmit; increasing traveling and trade; increasing ecological and demographic pressure. We reviewed the current state of knowledge based on published sources and available epidemiological data. The review was limited to potentially emerging viruses in Southeast Asia and the Pacific reported in human cases. Dengue, Chikungunya, and Japanese Encephalitis viruses have recurred on a yearly basis with a steady increase in these regions. Ross River and Barmah viruses now appear regularly in Australia, in an increasing number of cases. Nipah virus strikes regularly with limited but deadly epidemics in Southeast Asia. Finally, infections by lyssaviruses, Kunjin, Murray Valley, or Zika viruses were also reviewed. | 18,771,865 |
The relationship between cytokine concentrations and wound healing in chronic venous ulceration. | The importance of wound cytokine function in chronic venous leg ulcers remains poorly understood. This study evaluated the relationship between local and systemic concentrations of wound cytokines and wound healing in patients with chronic venous ulceration. This prospective observational study was set in a community- and hospital-based leg ulcer clinic. Consecutive patients with chronic leg ulceration and ankle-brachial pressure index >0.85 were prospectively investigated. All patients were treated with multilayer compression bandaging. Wound fluid and venous blood samples were collected at recruitment and 5 weeks later. In the wound fluid and venous blood, cytokines and factors reflecting the processes of inflammation (interleukin 1beta, tumor necrosis factor-alpha), proteolysis (matrix metalloproteinases-2 and -9), angiogenesis (basic fibroblast growth factor [bFGF], vascular endothelial growth factor), and fibrosis (transforming growth factor-beta(1) [TGFbeta(1)]) were measured. Ulcer healing was assessed using digital planimetry at both assessments. The study comprised 80 patients (43 men, 37 women). Median (range) ulcer size reduced from 4.4 (0.1-142.4) cm(2) to 2.2 (0-135.5) cm(2) after 5 weeks (P < .001; Wilcoxon signed rank), although 17 of 80 ulcers increased in size. The volume of wound fluid collected strongly correlated with ulcer size (Spearman rank = 0.801, P < .01). Initial wound fluid concentrations of bFGF correlated with ulcer size (Pearson coefficient = 0.641, P < .01), and changes in wound fluid TGFbeta(1) concentrations inversely correlated with changes in ulcer size (Spearman rank = -0.645, P = .032). There were no significant correlations between changes in other factors and ulcer healing. Wound fluid and serum cytokine concentrations correlated poorly. Wound fluid collection volume correlates with ulcer size. Ulcer healing correlated with increased concentrations of TGFbeta(1), possibly reflecting increased fibrogenesis in the proliferating wound. Aside from this, there was a large variation in wound and serum cytokine levels that largely limits their usefulness as markers of healing. | 18,771,884 |
Alveolar bone grafting in the treatment of midline alveolar cleft and diastema in incomplete median cleft lip. | Median cleft lip is a rare congenital anomaly. The wide diastema with mesial tipping observed in these patients has been largely overlooked. A midline submucosal alveolar cleft prevents adequate treatment. The purpose of this article is to describe an alveolar bone grafting (ABG) technique used in the combined surgical-orthodontic approach to diastema treatment in patients presenting with incomplete median cleft lip. Patients treated for incomplete median cleft lip and diastema were identified in the clinic registry from 1981 to 2007. Six patients were identified; 4 underwent ABG before permanent maxillary incisor eruption, the other 2 were seen later when they were 11 years old. All 6 ABGs were successful. The incisors erupted through the graft or were successfully moved into it with lasting results. Follow-up ranged from 8 to 21 years. The existence of a midline submucosal alveolar cleft and subsequent diastema should be recognized and addressed in all patients who present with incomplete median cleft lip repair. This includes taking maxillary occlusal view X-rays before the age of 5 years to detect the cleft, and proceed to ABG if necessary, generally before permanent maxillary incisor eruption. | 18,771,899 |
Relevance of botulinum toxin injection and nerve block of rectus femoris to kinematic and functional parameters of stiff knee gait in hemiplegic adults. | Stiff knee gait (SKG) is common in hemiplegic patients. The main focus of treatment is rectus femoris (RF) spasticity. The aims of this study were to evaluate the effect of botulinum toxin injection (BTI) in the RF muscle on peak knee flexion during swing phase and its quantitative and functional impact on gait. We also wished to evaluate the correlation between the effects of nerve block and BTI on peak knee flexion. 10 adult hemiplegic subjects (>6 months post stroke or traumatic brain injury) with SKG and inappropriate RF EMG activity during mid-swing phase were included. 3D gait analysis, clinical and functional assessments (Timed Up and Go test, 10 m walk test, 6 min walk test and the time taken to ascend and descend a flight of stairs) were performed initially, 30 min after anaesthetic block of the RF nerve and one month post BTI. After BTI, there was a significant increase in knee flexion (8 degrees average) and a tendency towards improvement in gait and functional parameters. The effect of the nerve block on peak knee flexion was significantly correlated with the effect of BTI (11 degrees average increase in peak knee flexion after nerve block). We challenge the relevance of RF nerve blocks in this population when EMG and kinematic data are available. Our results indicate that BTI is an effective treatment for SKG in adult hemiplegic subjects, with a significant increase in peak knee flexion, no reduction in hip flexion and a tendency towards functional improvements. | 18,771,925 |
Tibial tubercle osteotomy in primary total knee arthroplasty: a safe procedure or not? | The objective of this study was to investigate the influence of tibial tubercle osteotomy on postoperative outcome, intra- and postoperative complications, as well as postoperative clinical results and failures in primary total knee arthroplasty (TKA). In a continuous, consecutive series of 1474 primary TKA, we analysed 126 cases where a tibial tubercle osteotomy approach was performed and 1348 cases without tibial tubercle osteotomy. Before surgery, all patients underwent a systematic assessment that included a clinical examination, radiographs (stress hip-knee-ankle film [pangonogram], weight bearing, anteroposterior knee view, schuss view, profile and patellar axial view at 30 degrees, stress valgus and varus view) and International Knee Society scores. When analysing intraoperative complications, tibial plateau fissures or fractures and tibial tubercle fracture were considered as complications relating to the tibial tubercle osteotomy group (p<0.001, p=0.007). With a 2-year minimum follow-up, there was no statistical difference in the number of revisions carried out in the two study groups (p=0.084). However, postoperative tibial tubercle fracture and skin necrosis were significantly related to the osteotomy (p=0.001 and p</=0.001, respectively). Tibial tubercle osteotomy cannot be considered an entirely safe procedure in primary TKA as it is associated with local complications, particularly skin necrosis and fracture of the tibial tubercle. Therefore, tibial tubercle osteotomy should be performed only when necessary, i.e. in cases where there are difficulties gaining adequate surgical exposure, ligament balance and correct implant positioning. The procedure also demands considerable surgical experience to achieve a good outcome. | 18,771,928 |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.