334 research outputs found

    Peptidyl-prolyl cis-trans isomerases (immunophilins) and their roles in parasite biochemistry, host-parasite interaction and antiparasitic drug action.

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    Immunophilin is the collective name given to the cyclophilin and FK506-binding protein (FKBP) families. As the name suggests, these include the major binding proteins of certain immunosuppressive drugs: cyclophilins for the cyclic peptide cyclosporin A and FKBPs for the macrolactones FK506 and rapamycin. Both families, although dissimilar in sequence, possess peptidyl-prolyl <i>cis-trans</i> isomerase activity in vitro and can play roles in protein folding and transport, RNA splicing and the regulation of multiprotein complexes in cells. In addition to enzymic activity, many immunophilins act as molecular chaperones. This property may be conferred by the isomerase domain and/or by additional domains. Recent years have seen a great increase in the number of known immunophilin genes in parasitic protozoa and helminths and in many cases their products have been characterized biochemically and their temporal and spatial expression patterns have been examined. Some of these genes represent novel types: one example is a <i>Toxoplasma gondii</i> gene encoding a protein with both cyclophilin and FKBP domains. Likely roles in protein folding and oligomerisation, RNA splicing and sexual differentiation have been suggested for parasite immunophilins. In addition, unexpected roles in parasite virulence (Mip FKBP of <i>Trypanosoma cruzi</i>) and host immuno-modulation (e.g. 18-kDa cyclophilin of <i>Toxoplasma gondii</i>) have been established. Furthermore, in view of the potent antiparasitic activities of cyclosporins, macrolactones and nonimmunosuppressive derivatives of these compounds, immunophilins may mediate drug action and/or may themselves represent potential drug targets. Investigation of the mechanisms of action of these agents may lead to the design of potent and selective antimalarial and other antiparasitic drugs. This review discusses the properties of immunophilins in parasites and the 'animal model' <i>Caenorhabditis elegans</i> and relates these to our understanding of the roles of these proteins in cellular biochemistry, host-parasite interaction and the antiparasitic mechanisms of the drugs that bind to them

    Impact of herpes zoster and post-herpetic neuralgia on patients’ quality of life: a patient-reported outcomes survey

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    Background: The impact of herpes zoster (HZ) and post-herpetic neuralgia (PHN) on patients’ quality of life (QoL) is currently poorly documented. Subjects and methods: Telephone interviews in Germany identified patients ≥50 years old with painful HZ diagnosed during the previous 5 years. Bespoke questions evaluated previous HZ episodes. Results: Of 11,009 respondents, 280 met the screening criteria, and 32 (11%) developed PHN. PHN was associated with significantly worse outcomes than HZ (all P < 0.05). Mean pain scores associated with PHN and HZ, respectively, were 7.1 and 6.2 (average) and 8.2 and 7.0 (worst). Many patients with PHN (91%) and HZ (73%) experienced problems with daily activities, including work, studies, housework, family and leisure activities. Mean pain interference scores in patients with PHN versus HZ were highest for sleep (6.5 versus 4.9), normal work (6.1 versus 4.4) and mood (5.9 versus 4.4). Most employed interviewees with PHN (70%) and HZ (64%) stopped work during the disease. Pain and QoL outcomes were not significantly different between all patients versus those diagnosed during the previous 12 months or between patients aged 50–59 years versus ≥60 years. Conclusions: HZ causes substantial pain, which seriously interferes with many aspects of daily life, particularly in patients with PHN

    Single-Dose Intravenous Toxicity Study of IRDye 800CW in Sprague-Dawley Rats

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    Objective: Fluorophore-labeled contrast imaging agents are moving toward clinical use for a number of applications. The near-infrared dye IRDye 800CW is frequently used in its N-hydroxysuccinamide (NHS) ester form for labeling these agents. Following conjugation or breakdown of a labeled ligand, excess NHS ester is converted to the carboxylate form. To prepare for clinical use as a near-infrared fluorophore, a toxicity study was conducted on IRDye 800CW carboxylate. Methods: Male and female Sprague–Dawley rats were given a single intravenous or intradermal administration of IRDye 800CW carboxylate; Indocyanine Green was used as a comparative control. Animals were injected with varying doses of the test and control articles and observed for up to 14 days. Clinical chemistry, hematological, and pharmacokinetic analyses were performed on subgroups of animals. Organs were analyzed for content of the test article. Tissues were analyzed microscopically for pathological changes. Results: Based on hematologic, clinical chemistry, and histopathologic evaluation, single administration of IRDye 800CW carboxylate intravenously at dose levels of 1, 5, and 20 mg/kg or 20 mg/kg intradermally produced no pathological evidence of toxicity. Conclusion: A dose of 20 mg/kg was identified as the no observed adverse effect level following IV or ID routes of administration of IRDye 800CW

    Trends in publications regarding evidence-practice gaps: A literature review

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    <p>Abstract</p> <p>Background</p> <p>Well-designed trials of strategies to improve adherence to clinical practice guidelines are needed to close persistent evidence-practice gaps. We studied how the number of these trials is changing with time, and to what extent physicians are participating in such trials.</p> <p>Methods</p> <p>This is a literature-based study of trends in evidence-practice gap publications over 10 years and participation of clinicians in intervention trials to narrow evidence-practice gaps. We chose nine evidence-based guidelines and identified relevant publications in the PubMed database from January 1998 to December 2007. We coded these publications by study type (intervention versus non-intervention studies). We further subdivided intervention studies into those for clinicians and those for patients. Data were analyzed to determine if observed trends were statistically significant.</p> <p>Results</p> <p>We identified 1,151 publications that discussed evidence-practice gaps in nine topic areas. There were 169 intervention studies that were designed to improve adherence to well-established clinical guidelines, averaging 1.9 studies per year per topic area. Twenty-eight publications (34%; 95% CI: 24% - 45%) reported interventions intended for clinicians or health systems that met Effective Practice and Organization of Care (EPOC) criteria for adequate design. The median consent rate of physicians asked to participate in these well-designed studies was 60% (95% CI, 25% to 69%).</p> <p>Conclusions</p> <p>We evaluated research publications for nine evidence-practice gaps, and identified small numbers of well-designed intervention trials and low rates of physician participation in these trials.</p

    Evaluation of PCR on Bronchoalveolar Lavage Fluid for Diagnosis of Invasive Aspergillosis: A Bivariate Metaanalysis and Systematic Review

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    BACKGROUND: Nucleic acid detection by polymerase chain reaction (PCR) is emerging as a sensitive and rapid diagnostic tool. PCR assays on serum have the potential to be a practical diagnostic tool. However, PCR on bronchoalveolar lavage fluid (BALF) has not been well established. We performed a systematic review of published studies to evaluate the diagnostic accuracy of PCR assays on BALF for invasive aspergillosis (IA). METHODS: Relevant published studies were shortlisted to evaluate the quality of their methodologies. A bivariate regression approach was used to calculate pooled values of the method sensitivity, specificity, and positive and negative likelihood ratios. Hierarchical summary receiver operating characteristic curves were used to summarize overall performance. We calculated the post-test probability to evaluate clinical usefulness. Potential heterogeneity among studies was explored by subgroup analyses. RESULTS: Seventeen studies comprising 1191 at-risk patients were selected. The summary estimates of the BALF-PCR assay for proven and probable IA were as follows: sensitivity, 0.91 (95% confidence interval (CI), 0.79-0.96); specificity, 0.92 (95% CI, 0.87-0.96); positive likelihood ratio, 11.90 (95% CI, 6.80-20.80); and negative likelihood ratio, 0.10 (95% CI, 0.04-0.24). Subgroup analyses showed that the performance of the PCR assay was influenced by PCR assay methodology, primer design and the methods of cell wall disruption and DNA extraction. CONCLUSIONS: PCR assay on BALF is highly accurate for diagnosing IA in immunocompromised patients and is likely to be a useful diagnostic tool. However, further efforts towards devising a standard protocol are needed to enable formal validation of BALF-PCR
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