109 research outputs found
Sensitive and rapid detection of cholera toxin-producing Vibrio cholerae using a loop-mediated isothermal amplification
<p>Abstract</p> <p>Background</p> <p><it>Vibrio cholerae </it>is widely acknowledged as one of the most important waterborne pathogen causing gastrointestinal disorders. Cholera toxin (CT) is a major virulence determinant of <it>V. cholerae</it>. Detection of CT-producing <it>V. cholerae </it>using conventional culture-, biochemical- and immunological-based assays is time-consuming and laborious, requiring more than three days. Thus, we developed a novel and highly specific loop-mediated isothermal amplification (LAMP) assay for the sensitive and rapid detection of cholera toxin (CT)-producing <it>Vibrio cholerae</it>.</p> <p>Results</p> <p>The assay provided markedly more sensitive and rapid detection of CT-producing <it>V. cholerae </it>strains than conventional biochemical and PCR assays. The assay correctly identified 34 CT-producing <it>V. cholerae </it>strains, but did not detect 13 CT non-producing <it>V. cholerae </it>and 53 non-<it>V. cholerae </it>strains. Sensitivity of the LAMP assay for direct detection of CT-producing <it>V. cholerae </it>in spiked human feces was 7.8 × 10<sup>2 </sup>CFU per g (1.4 CFU per reaction). The sensitivity of the LAMP assay was 10-fold more sensitive than that of the conventional PCR assay. The LAMP assay for detection of CT-producing <it>V. cholerae </it>required less than 35 min with a single colony on thiosulfate citrate bile salt sucrose (TCBS) agar and 70 min with human feces from the beginning of DNA extraction to final determination.</p> <p>Conclusion</p> <p>The LAMP assay is a sensitive, rapid and simple tool for the detection of CT-producing <it>V. cholerae </it>and will be useful in facilitating the early diagnosis of human <it>V. cholerae </it>infection.</p
Histone H3.3 sub-variant H3mm7 is required for normal skeletal muscle regeneration
Regulation of gene expression requires selective incorporation of histone H3 variant H3.3 into chromatin. Histone H3.3 has several subsidiary variants but their functions are unclear. Here we characterize the function of histone H3.3 sub-variant, H3mm7, which is expressed in skeletal muscle satellite cells. H3mm7 knockout mice demonstrate an essential role of H3mm7 in skeletal muscle regeneration. Chromatin analysis reveals that H3mm7 facilitates transcription by forming an open chromatin structure around promoter regions including those of myogenic genes. The crystal structure of the nucleosome containing H3mm7 reveals that, unlike the S57 residue of other H3 proteins, the H3mm7-specific A57 residue cannot form a hydrogen bond with the R40 residue of the cognate H4 molecule. Consequently, the H3mm7 nucleosome is unstable in vitro and exhibited higher mobility in vivo compared with the H3.3 nucleosome. We conclude that the unstable H3mm7 nucleosome may be required for proper skeletal muscle differentiation
[研究ノート] 高齢者集落における社会的紐帯と健康状態の関連への文化人類学からのアプローチ:秋田県男鹿市A地区B集落での予備調査から
要旨:保健分野のソーシャル・キャピタル研究では、ソーシャル・キャピタルの内実が地域毎に異なるにも関わらずその内実が解明されず、またソーシャル・キャピタルと健康の因果関係が明らかにされないという2つの問題点がある。本研究では、対象社会の社会構造の特徴を精査した上で、それが集団レベルの健康状態と結びつくメカニズムの解明を目指す文化人類学の手法を構想した。2015年4月から秋田県男鹿市A地区の住民を対象に行った現在までの予備調査では、対象地域住民の間で社会的紐帯が強く、その背景に親族組織や農事勉強会などの社会組織が関連するという手がかりを得た。本稿では現在までに得た予備調査データを参照しつつ本研究の構想を示す。Abstract:Many studies have been conducted using the concept of social capital in the fi eld of health recently. These studies typically have two problems. The first is that they do not pay close attention to the actual situation of social capital, although there are real diff erences amongst communities. The second is that they do not discuss causation between social capital and health status. Thus, in this study, we utilize a cultural anthropological approach to investigate the relationship between the social structure and the health status of a given group, based on a survey of the characteristics of social structure in the subject community. The participants are located in the (A) district of Ogacity, Akita, where we have been conducting fieldwork since April, 2015. According to our preliminary fieldwork, we have discovered results, which suggest that the connection amongst the people was strong in the subject community, which has a relationship with social organizations such as a kin group, agricultural study meeting, and so on. In this article, we present our research framework based on data from our preliminary fieldwork
Clinical relevance of heparin-PF4 complex antibody in DVT after total joint replacement
<p>Abstract</p> <p>Background</p> <p>Antibodies to the heparin-platelet factor-4 (HPF-4) complex (HIT antibodies) have been observed in patients with heparin-induced thrombocytopenia (HIT). These antibodies are thought to be involved in thrombosis through activation of platelet/endothelial cells. This prospective study was conducted to determine the incidence of post-operative HIT antibodies to assess the associated risk of deep vein thrombosis (DVT) in patients undergoing total knee arthroplasty (TKA) or total hip arthroplasty (THA).</p> <p>Methods</p> <p>We studied 104 patients who underwent unilateral primary TKA (n = 44) and primary THA (n = 60) with short-duration prophylaxis (1–2 days of a fixed dose of unfractionated heparin). HIT antibodies were assayed using a sandwich-type ELISA before the operation and after heparin treatment (post-operative day 7).</p> <p>Results</p> <p>In the clinical outcome, the incidence of symptomatic DVT was 15.4% (16/104, TKA; 10, THA 6) and pulmonary embolism (PE) was not observed. The total seroconversion rate of HIT antibodies at post-operative day 7 was 34.6% (36/104). Among 36 seroconverted patients, 11 (30.6%) developed symptomatic DVT and 5 out of 68 of the non-seroconverted patients (7.4%) developed symptomatic DVT. The incidence for DVT was significantly higher in the seroconverted patients compared with that of the non-seroconverted patients (odds ratio 5.5, 95%CI: 1.7–17.6 <it>p </it>= 0.0028). Furthermore, in the patients with symptomatic DVT, the titer of HIT antibodies at post-operative day 7 was significantly higher compared with those without symptomatic DVT.</p> <p>Conclusion</p> <p>Our data therefore suggest that seroconversion for HIT antibodies generated by heparin is associated with a risk of DVT in patients undergoing total joint replacement.</p
Discovery of widespread transcription initiation at microsatellites predictable by sequence-based deep neural network
Using the Cap Analysis of Gene Expression (CAGE) technology, the FANTOM5 consortium provided one of the most comprehensive maps of transcription start sites (TSSs) in several species. Strikingly, ~72% of them could not be assigned to a specific gene and initiate at unconventional regions, outside promoters or enhancers. Here, we probe these unassigned TSSs and show that, in all species studied, a significant fraction of CAGE peaks initiate at microsatellites, also called short tandem repeats (STRs). To confirm this transcription, we develop Cap Trap RNA-seq, a technology which combines cap trapping and long read MinION sequencing. We train sequence-based deep learning models able to predict CAGE signal at STRs with high accuracy. These models unveil the importance of STR surrounding sequences not only to distinguish STR classes, but also to predict the level of transcription initiation. Importantly, genetic variants linked to human diseases are preferentially found at STRs with high transcription initiation level, supporting the biological and clinical relevance of transcription initiation at STRs. Together, our results extend the repertoire of non-coding transcription associated with DNA tandem repeats and complexify STR polymorphism
Relationship between depression score and acidbase status in Japanese Black calves with diarrhea
We evaluated the relationship between depression score and acid-base status in 84 purebred and crossbred Japanese Black calves. The bicarbonate (p<0.001) and base excess concentrations (p<0.001) were significantly and negatively correlated with the depression scores of the calves. The proposed diagnostic cutoff point for a depression score that indicates severe metabolic acidosis (BE < -10 mM) is 6.5 based on analysis of the ROC curve. The sensitivity and specificity were 88.4% and 81.2%, respectively. The depression scoring system is a useful tool for evaluation of the acid-base status of purebred and crossbred Japanese Black calves. In addition, a depression score of 6.5 suggests severe metabolic acidosis and that intravenous infusion of sodium bicarbonate solution is necessary
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