710 research outputs found

    Vigabatrin-Induced Peripheral Visual Field Defects in Patients With Refractory Partial Epilepsy

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    Purpose: Vigabatrin can cause retinopathy, resulting in bilateral visual field constriction. Previous analyses of results from a prospective, observational study assessing vigabatrin-induced visual field constriction (described below) employed a partially subjective interpretation of static perimetery. In an effort to affirm these previous findings through more objective, quantitative methodology, we now report data from a subset analysis of refractory partial epilepsy patients in the study who underwent Goldmann kinetic perimetry. Methods: Patients aged ≥8 years with refractory partial seizures were enrolled and grouped: those receiving vigabatrin for ≥6 months (Group I); those who had received vigabatrin for ≥6 months and then had discontinued for ≥6 months (Group II); and those naïve to vigabatrin (Group III). Patients underwent static or kinetic perimetry or both every 4–6 months for ≤3 years. For kinetic perimetry, the temporal and nasal visual fields were measured along the horizontal meridian with the largest (V4e, IV4e) and smallest (I2e, I1e) isopters, respectively. Results: Of 735 patients enrolled, 341 had Goldmann perimetry data. Of these, 258 received vigabatrin. Sixteen percent of vigabatrin-exposed patients had moderate visual field defects (30°–60° retained temporal vision), and 3% had severe defects (\u3c30° retained temporal vision). Visual function questionnaire results indicated a weak correlation between visual field constriction severity and visual symptoms. Conclusions: These results affirm both an analysis of the same study based primarily on static perimetry and findings from cross-sectional studies. The present analysis verifies that visual field constriction, when it occurs, is most often mild or moderate and is not associated with symptoms of abnormal visual function. The clinical decision to prescribe vigabatrin should be based on a benefit-risk analysis for each individual patient

    Assessment of Changes of Complex Shoreline from Medium‑Resolution Satellite Imagery

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    The imagery collected by medium-resolution earth-observing satellites is a powerful and cost-effective tool for the quantitative assessment of shoreline dynamics for water bodies of different spatial scales. In this study, we utilize imagery collected in 1984–2021 on the Middle Peninsula, Virginia, bordering the Chesapeake Bay, USA, by medium-resolution (10–30 m) satellites Landsat-5/7/8 and Sentinel-2A/B. The data was managed in the Earth Analytics Interoperability Lab (EAIL) Data Cube built and configured by the Commonwealth Scientific and Industrial Research Organization (CSIRO, Australia and Chile). The assessments of shoreline change demonstrate adequate agreement with assessments based on aerial photography collected during 1937–2009 by the Virginia Institute of Marine Science, with reasonable disagreement attributed to the differences in the analyzed periods and in the accuracy of land/ water edge detection. Most of the studied coastline was subject to land loss (erosion), in some locations exceeding 3 m year− 1, usually along low-lying sandy beaches. The shoreline segments with man-made structures such as marinas, bulkheads, revetments, and offshore breakwaters demonstrated a significantly lower range of changes as compared to natural reaches. Regular analysis of medium resolution satellite imagery appears to be an effective method for routine assessment of shoreline changes along the land/water edge

    Cautionary Tale of Using Tris(alkyl)phosphine Reducing Agents with NAD+-Dependent Enzymes

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    Protein biochemistry protocols typically include disulfide bond reducing agents to guard against unwanted thiol oxidation and protein aggregation. Commonly used disulfide bond reducing agents include dithiothreitol, β-mercaptoethanol, glutathione, and the tris(alkyl)phosphine compounds tris(2-carboxyethyl)phosphine (TCEP) and tris(3-hydroxypropyl)phosphine (THPP). While studying the catalytic activity of the NAD(P)H-dependent enzyme Δ1-pyrroline-5-carboxylate reductase, we unexpectedly observed a rapid non-enzymatic chemical reaction between NAD+ and the reducing agents TCEP and THPP. The product of the reaction exhibits a maximum ultraviolet absorbance peak at 334 nm and forms with an apparent association rate constant of 231–491 M−1 s−1. The reaction is reversible, and nuclear magnetic resonance characterization (1H, 13C, and 31P) of the product revealed a covalent adduct between the phosphorus of the tris(alkyl)phosphine reducing agent and the C4 atom of the nicotinamide ring of NAD+. We also report a 1.45 Å resolution crystal structure of short-chain dehydrogenase/reductase with the NADP+–TCEP reaction product bound in the cofactor binding site, which shows that the adduct can potentially inhibit enzymes. These findings serve to caution researchers when using TCEP or THPP in experimental protocols with NAD(P)+. Because NAD(P)+-dependent oxidoreductases are widespread in nature, our results may be broadly relevant

    Colwellia psychrerythraea Strains from Distant Deep Sea Basins Show Adaptation to Local Conditions

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    Many studies have shown that microbes, which share nearly identical 16S rRNA genes, can have highly divergent genomes. Microbes from distinct parts of the ocean also exhibit biogeographic patterning. Here we seek to better understand how certain microbes from the same species have adapted for growth under local conditions. The phenotypic and genomic heterogeneity of three strains of Colwellia psychrerythraeawas investigated in order to understand adaptions to local environments. Colwellia are psychrophilic heterotrophic marine bacteria ubiquitous in cold marine ecosystems. We have recently isolated two Colwellia strains: ND2E from the Eastern Mediterranean and GAB14E from the Great Australian Bight. The 16S rRNA sequence of these two strains were greater than 98.2% identical to the well-characterized C. psychrerythraea 34H, which was isolated from arctic sediments. Salt tolerance, and carbon source utilization profiles for these strains were determined using Biolog Phenotype MicoArrays. These strains exhibited distinct salt tolerance, which was not associated with the salinity of sites of isolation. The carbon source utilization profiles were distinct with less than half of the tested carbon sources being metabolized by all three strains. Whole genome sequencing revealed that the genomes of these three strains were quite diverse with some genomes having up to 1600 strain-specific genes. Many genes involved in degrading strain-specific carbon sources were identified. There appears to be a link between carbon source utilization and location of isolation with distinctions observed between the Colwellia isolate recovered from sediment compared to water column isolates

    Comparing professional and consumer ratings of mental health apps : mixed methods study

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    Background: As the number of mental health apps has grown, increasing efforts have been focused on establishing quality tailored reviews. These reviews prioritize clinician and academic views rather than the views of those who use them, particularly those with lived experiences of mental health problems. Given that the COVID-19 pandemic has increased reliance on web-based and mobile mental health support, understanding the views of those with mental health conditions is of increasing importance. Objective: This study aimed to understand the opinions of people with mental health problems on mental health apps and how they differ from established ratings by professionals. Methods: A mixed methods study was conducted using a web-based survey administered between December 2020 and April 2021, assessing 11 mental health apps. We recruited individuals who had experienced mental health problems to download and use 3 apps for 3 days and complete a survey. The survey consisted of the One Mind PsyberGuide Consumer Review Questionnaire and 2 items from the Mobile App Rating Scale (star and recommendation ratings from 1 to 5). The consumer review questionnaire contained a series of open-ended questions, which were thematically analyzed and using a predefined protocol, converted into binary (positive or negative) ratings, and compared with app ratings by professionals and star ratings from app stores. Results: We found low agreement between the participants’ and professionals’ ratings. More than half of the app ratings showed disagreement between participants and professionals (198/372, 53.2%). Compared with participants, professionals gave the apps higher star ratings (3.58 vs 4.56) and were more likely to recommend the apps to others (3.44 vs 4.39). Participants’ star ratings were weakly positively correlated with app store ratings (r=0.32, P=.01). Thematic analysis found 11 themes, including issues of user experience, ease of use and interactivity, privacy concerns, customization, and integration with daily life. Participants particularly valued certain aspects of mental health apps, which appear to be overlooked by professional reviewers. These included functions such as the ability to track and measure mental health and providing general mental health education. The cost of apps was among the most important factors for participants. Although this is already considered by professionals, this information is not always easily accessible. Conclusions: As reviews on app stores and by professionals differ from those by people with lived experiences of mental health problems, these alone are not sufficient to provide people with mental health problems with the information they desire when choosing a mental health app. App rating measures must include the perspectives of mental health service users to ensure ratings represent their priorities. Additional work should be done to incorporate the features most important to mental health service users into mental health apps

    Dynamic regulation of the endocannabinoid system: implications for analgesia

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    The analgesic effects of cannabinoids are well documented, but these are often limited by psychoactive side-effects. Recent studies indicate that the endocannabinoid system is dynamic and altered under different pathological conditions, including pain states. Changes in this receptor system include altered expression of receptors, differential synthetic pathways for endocannabinoids are expressed by various cell types, multiple pathways of catabolism and the generation of biologically active metabolites, which may be engaged under different conditions. This review discusses the evidence that pain states alter the endocannabinoid receptor system at key sites involved in pain processing and how these changes may inform the development of cannabinoid-based analgesics
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