Effects of Terrestrial Buffer Zones on Amphibians on Golf Courses

A major cause of amphibian declines worldwide is habitat destruction or alteration. Public green spaces, such as golf courses and parks, could serve as safe havens to curb the effects of habitat loss if managed in ways to bolster local amphibian communities. We reared larval Blanchard's cricket frogs (Acris blanchardi) and green frogs (Rana clamitans) in golf course ponds with and without 1 m terrestrial buffer zones, and released marked cricket frog metamorphs at the golf course ponds they were reared in. Larval survival of both species was affected by the presence of a buffer zone, with increased survival for cricket frogs and decreased survival for green frogs when reared in ponds with buffer zones. No marked cricket frog juveniles were recovered at any golf course pond in the following year, suggesting that most animals died or migrated. In a separate study, we released cricket frogs in a terrestrial pen and allowed them to choose between mown and unmown grass. Cricket frogs had a greater probability of using unmown versus mown grass. Our results suggest that incorporating buffer zones around ponds can offer suitable habitat for some amphibian species and can improve the quality of the aquatic environment for some sensitive local amphibians

Dapsone‐ and nitroso dapsone‐specific activation of T cells from hypersensitive patients expressing the risk allele HLA‐B*13:01

BACKGROUND:Research into drug hypersensitivity associated with expression of specific HLA alleles has focussed on the interaction between parent drug and the HLA with no attention given to reactive metabolites. For this reason, we have studied HLA-B*13:01-linked dapsone hypersensitivity to (1) explore whether the parent drug and/or nitroso metabolite activates T-cells and (2) determine whether HLA-B*13:01 is involved in the response. METHODS:PBMC from 6 patients were cultured with dapsone and nitroso dapsone and proliferative responses and IFN-γ release were measured. Dapsone- and nitroso dapsone-specific T-cell clones were generated and phenotype, function, HLA allele restriction and cross-reactivity assessed. Dapsone intermediates were characterized by mass spectrometry. RESULTS:PBMC from 6 patients and cloned T-cells proliferated and secreted Th1/2/22 cytokines when stimulated with dapsone (clones: n=395; 80% CD4+ CXCR3hi CCR4hi , 20% CD8+CXCR3hi CCR4hi CCR6hi CCR9hi CCR10hi ) and nitroso dapsone (clones: n=399; 78% CD4+, 22% CD8+ with same chemokine receptor profile). CD4+ and CD8+ clones were HLA-class II and class I restricted, respectively, and displayed three patterns of reactivity: compound-specific, weakly crossreactive and strongly cross reactive. Nitroso dapsone formed dimers in culture and was reduced to dapsone, providing a rationale for the crossreactivity. T-cell responses to nitroso dapsone were dependent on the formation of a cysteine-modified protein adduct, while dapsone interacted in a labile manner with antigen presenting cells. CD8+ clones displayed an HLA-B*13:01-restricted pattern of activation. CONCLUSION:These studies describe the phenotype and function of dapsone- and nitroso dapsone-responsive CD4+ and CD8+ T-cells from hypersensitive patients. Discovery of HLA-B*13:01-restricted CD8+ T-cell responses indicates that drugs and their reactive metabolites participate in HLA allele-linked forms of hypersensitivity. This article is protected by copyright. All rights reserved

Large expert-curated database for benchmarking document similarity detection in biomedical literature search

Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency–Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research

Rare Variant Burden Analysis within Enhancers Identifies CAV1 as an ALS Risk Gene

Amyotrophic lateral sclerosis (ALS) is an incurable neurodegenerative disease. CAV1 and CAV2 organize membrane lipid rafts (MLRs) important for cell signaling and neuronal survival, and overexpression of CAV1 ameliorates ALS phenotypes in vivo. Genome-wide association studies localize a large proportion of ALS risk variants within the non-coding genome, but further characterization has been limited by lack of appropriate tools. By designing and applying a pipeline to identify pathogenic genetic variation within enhancer elements responsible for regulating gene expression, we identify disease-associated variation within CAV1/CAV2 enhancers, which replicate in an independent cohort. Discovered enhancer mutations reduce CAV1/CAV2 expression and disrupt MLRs in patient-derived cells, and CRISPR-Cas9 perturbation proximate to a patient mutation is sufficient to reduce CAV1/CAV2 expression in neurons. Additional enrichment of ALS-associated mutations within CAV1 exons positions CAV1 as an ALS risk gene. We propose CAV1/CAV2 overexpression as a personalized medicine target for ALS

Impaired permeability to IP3 in a mutant connexin underlies recessive hereditary deafness

Connexins are membrane proteins that assemble into gap-junction channels and are responsible for direct, electrical and metabolic coupling between connected cells. Here we describe an investigation of the properties of a recombinantly expressed recessive mutant of connexin 26 (Cx26), the V84L mutant, associated with deafness. Unlike other Cx26 mutations, V84L affects neither intracellular sorting nor electrical coupling, but specifically reduces permeability to the Ca2+-mobilizing messenger inositol 1,4,5-trisphosphate (Ins(1,4,5)P-3). Both the permeability to Lucifer Yellow and the unitary channel conductance of V84L-mutant channels are indistinguishable from those of the wildtype Cx26. Injection of Ins(1,4,5)P-3 into supporting cells of the rat organ of Corti, which abundantly express Cx26, ensues in a regenerative wave of Ca2+ throughout the tissue. Blocking the gap junction communication abolishes wave propagation. We propose that the V84L mutation reduces metabolic coupling mediated by Ins(1,4,5)P-3 to an extent sufficient to impair the propagation of Ca2+ waves and the formation of a functional syncytium. Our data provide the first demonstration of a specific defect of metabolic coupling and offer a mechanistic explanation for the pathogenesis of an inherited human disease