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Bacteroides fragilis ATCC25285から得られたアルカリ安定脂質は赤外吸収スペクトルでアミド結合に由来する特徴的な吸収がみられることや,スフィンゴシンを有することなどからスフィンゴリン脂質であることが示された。このスフィンゴリン脂質の薄層クロマトグラフィーによる分析からセラミドホスホリルエタノールアミン(CPE)とセラミドホスホリルグリセロール(CPG)の2種類のスフィンゴリン脂質が検出された。また,Bacteroides属の全10菌種についてスフインゴリン脂質の組成を分析して菌種間の分布を調べたところ,CPEとCPGは7菌種から見いだされた。さらに,薄層クロマトグラフ上にはスフィンゴリン脂質と考えられる未知スポットが見いだされた。各菌種で見いだされたスフィンゴリン脂質組成は,菌種について特徴的であり,菌株間での変異は認められなかった

DOCK2 is involved in the host genetics and biology of severe COVID-19

「コロナ制圧タスクフォース」COVID-19疾患感受性遺伝子DOCK2の重症化機序を解明 --アジア最大のバイオレポジトリーでCOVID-19の治療標的を発見--. 京都大学プレスリリース. 2022-08-10.Identifying the host genetic factors underlying severe COVID-19 is an emerging challenge. Here we conducted a genome-wide association study (GWAS) involving 2, 393 cases of COVID-19 in a cohort of Japanese individuals collected during the initial waves of the pandemic, with 3, 289 unaffected controls. We identified a variant on chromosome 5 at 5q35 (rs60200309-A), close to the dedicator of cytokinesis 2 gene (DOCK2), which was associated with severe COVID-19 in patients less than 65 years of age. This risk allele was prevalent in East Asian individuals but rare in Europeans, highlighting the value of genome-wide association studies in non-European populations. RNA-sequencing analysis of 473 bulk peripheral blood samples identified decreased expression of DOCK2 associated with the risk allele in these younger patients. DOCK2 expression was suppressed in patients with severe cases of COVID-19. Single-cell RNA-sequencing analysis (n = 61 individuals) identified cell-type-specific downregulation of DOCK2 and a COVID-19-specific decreasing effect of the risk allele on DOCK2 expression in non-classical monocytes. Immunohistochemistry of lung specimens from patients with severe COVID-19 pneumonia showed suppressed DOCK2 expression. Moreover, inhibition of DOCK2 function with CPYPP increased the severity of pneumonia in a Syrian hamster model of SARS-CoV-2 infection, characterized by weight loss, lung oedema, enhanced viral loads, impaired macrophage recruitment and dysregulated type I interferon responses. We conclude that DOCK2 has an important role in the host immune response to SARS-CoV-2 infection and the development of severe COVID-19, and could be further explored as a potential biomarker and/or therapeutic target

The whole blood transcriptional regulation landscape in 465 COVID-19 infected samples from Japan COVID-19 Task Force

「コロナ制圧タスクフォース」COVID-19患者由来の血液細胞における遺伝子発現の網羅的解析 --重症度に応じた遺伝子発現の変化には、ヒトゲノム配列の個人差が影響する--. 京都大学プレスリリース. 2022-08-23.Coronavirus disease 2019 (COVID-19) is a recently-emerged infectious disease that has caused millions of deaths, where comprehensive understanding of disease mechanisms is still unestablished. In particular, studies of gene expression dynamics and regulation landscape in COVID-19 infected individuals are limited. Here, we report on a thorough analysis of whole blood RNA-seq data from 465 genotyped samples from the Japan COVID-19 Task Force, including 359 severe and 106 non-severe COVID-19 cases. We discover 1169 putative causal expression quantitative trait loci (eQTLs) including 34 possible colocalizations with biobank fine-mapping results of hematopoietic traits in a Japanese population, 1549 putative causal splice QTLs (sQTLs; e.g. two independent sQTLs at TOR1AIP1), as well as biologically interpretable trans-eQTL examples (e.g., REST and STING1), all fine-mapped at single variant resolution. We perform differential gene expression analysis to elucidate 198 genes with increased expression in severe COVID-19 cases and enriched for innate immune-related functions. Finally, we evaluate the limited but non-zero effect of COVID-19 phenotype on eQTL discovery, and highlight the presence of COVID-19 severity-interaction eQTLs (ieQTLs; e.g., CLEC4C and MYBL2). Our study provides a comprehensive catalog of whole blood regulatory variants in Japanese, as well as a reference for transcriptional landscapes in response to COVID-19 infection

Small intestinal intussusceptions due to the placement of a percutaneous endoscopic jejunostomy tube

http://dx.doi.org/10.1136/bcr.07.2010.3169 AuthorPercutaneous endoscopic jejunostomy (PEJ) has been developed and is considered to be a better method than percutaneous endoscopic gastrostomy for preventing the occurrence of aspiration pneumonia. However, the incidence of other complications associated with this procedure is less clear. We herein report a rare case with a small intestinal intussusception due to a PEJ placement. In this case, a radiologic examination with gastrografin was useful to detect the typical findings of a small intestinal intussusception, a beak-like filling defect, and identify the location of the lesion. An endoscopic examination that was carefully performed with a thin scope was effective to observe the ischaemic change of the small intestine and immediately determine the indication for surgical treatment. This case highlights the necessity to carefully manage patients with a PEJ placement, considering the risk of small intestinal intussusceptions when the patient complains of symptoms that are suspicious for an intestinal obstruction