Markers for Risk of Type 1 Diabetes in Relatives of Alsacian Patients With Type 1 Diabetes

Background: The cytotoxic T lymphocyteassociated antigen 4 gene (CTLA-4) encode the T cell receptor involved in the control of T cell proliferation and mediates T cell apoptosis. The receptor protein is a specific T lymphocyte surface antigen that is detected on cells only after antigen presentation. Thus, CTLA-4 is directly involved in both immune and autoimmune responses and may be involved in the pathogenesis of multiple T cell-mediated autoimmune disorders. There is polymorphism at position 49 in exon 1 of the CTLA-4 gene, providing an A-G exchange. Moreover, we assessed the CTLA-4 49 (Thr/Ala) polymorphism in diabetic patients and first-degree relatives as compared to control subjects. Research design and methods: Three loci (HLA-DQB1, DQA1 and CTLA-4) were analysed in 62 type 1 diabetic patients, 72 firstdegree relatives and 84 nondiabetic control subjects by means of PCR-RFLP. Results: A significant enrichment in DQB1 alleles encoding for an amino acid different from Asp in position 57 (NA) and DQA1 alleles encoding for Arg in position 52 was observed in diabetic subjects and first-degree relatives as compared to controls. The genotype and allele frequencies of these polymorphisms in type 1 diabetic patients and firstdegree relatives differed significantly from those of controls (p< 0.001 and 0.05 respectively). CTLA-49 Ala alleles frequencies were 75.8% in type 1 diabetic patients and 68.1% in first-degree relatives in comparison to 35.7% in control subjects. The Ala/Ala genotype conferred a relative risk of 18.8 (p < 0.001). Conclusion: The CTLA-4 49 Ala allele confers an increased risk of type 1 diabetes, independent of age and HLA-DQ genetic markers.     

A lesson from polybutylene succinate plastisphere to the discovery of novel plastic degrading enzyme genes in marine vibrios

Polybutylene succinate (PBS) is an eco-friendly green plastic. However, PBS was shown as being non-biodegradable in marine environments, and up until now, only a limited number of PBS-degrading marine microbes have been discovered. We first set up in vitro PBS- and PBSA (polybutylene succinate adipate)-plastispheres to characterize novel PBS-degrading marine microbes. Microbial growth and oxygen consumption were observed in both PBS- and PBSA-plastispheres enriched with natural seawater collected from Usujiri, Hokkaido, Japan, and Vibrionaceae and Pseudoalteromonadaceae were significantly enriched on these films. Further gene identification indicated that vibrios belonging to the Gazogenes clade possess genes related to a PBS degrading enzyme (PBSase). The PBS degradation assay for six Gazogenes clade vibrios identified Vibrio ruber, Vibrio rhizosphaerae, and Vibrio spartinae as being capable of degrading PBS. We further identified the gene responsible for PBSase from the type strain of V. ruber, and the purified recombinant vibrio PBSase was found to have low-temperature adaptation and was active under high NaCl concentrations. We also provided docking models between the vibrio PBSase and PBS and PBSA units to show how vibrio PBSase interacts with each substrate compared to the Acidovorax PBSase. These results could contribute to a more sustainable society through further utilization of PBS in marine environments and plastic recycling.     

Interpretation and predictions of the Emergent neutrality model: a reply to Barabás et al.

Formulated in 2006, Scheffer and van Nes’ Emergent neutrality model predicts that competing species might self‐organize into groups of species similar in their traits. Recently, Vergnon et al. showed that the model consistently generates multimodal species abundance distributions, in accordance with empirical data. Barabás et al. argue that Emergent neutrality model relies on unmodeled, ‘hidden’ species differences. They also suggest that an Emergent neutrality model explicitly integrating such differences may fail to generate multimodal species abundance distributions, while other models can robustly produce those patterns. Here we demonstrate that density dependence – the process deemed problematic by Barabás et al. – may permanently maintain groups of similar species without need for additional species differences. More broadly, we make it clear that density dependence is not the only likely mechanism that could allow the permanent coexistence of similar species in the Emergent neutrality framework. We welcome the finding that models other than Emergent neutrality can generate multimodal abundance distributions and we briefly discuss their novelty and relevance.     

A comparison of the anatomical distribution of substance P and substance P receptors in the rat central nervous system

A comparison of anatomical distributions of substance P (SP) and substance P receptors in the rat central nervous system was performed. SP was localized by microdissection and radioimmunoassay and SP fibers and cell bodies by immunohistochemistry. Receptors for ¹²⁵I-Bolton Hunter labelled SP (¹²⁵I-BH-SP) were characterized pharmacologically by a slice binding technique in sections that contained primarily striatum. The receptor was saturable and had an equilibrium dissociation constant (K_D) of 0.30 nM and maximum number of binding sites (B_max) of 37.8 fmol/mg protein. Pharmacological characterization using C terminal fragments and naturally occurring analogues of SP reflected characteristics of the receptor which had been shown previously in bioassays and biochemical assays. Comparison of distribution of SP fibers and cell bodies and SP receptors indicated that there is no consistent relationship between the amount of SP receptor and density of SP fibers or cell bodies in a given region of the brain.