Sample Collection and Processing in Volatile Organic Compound Analysis for Gastrointestinal Cancers.

Volatile organic compounds have drawn significant attention in recent years as a novel tool for non-invasive detection of a wide range of diseases, including gastrointestinal cancers, for which the need for effective, affordable, and non-invasive screening methods is substantial. Sample preparation is a fundamental step that greatly influences the quality of results and the feasibility of wide-range applications. This review summarizes sampling methods used in studies aiming at testing the diagnostic value of volatile organic compounds in gastrointestinal cancers, discussing in detail some of the recent advancements in automated sampling techniques. Finally, we propose some directions in which sample collection and processing can improve for VOC analysis to be popularized in clinical settings.

miRNA­21 promotes the progression of acute liver failure via the KLF6/autophagy/IL­23 signaling pathway.

Acute liver failure (ALF) is a complex syndrome characterized by overactivation of innate immunity, and the recruitment and differentiation of immune cells at inflammatory sites. The present study aimed to explore the role of microRNA (miRNA/miR)­21 and its potential mechanisms underlying inflammatory responses in ALF. Baseline serum miR­21 was analyzed in patients with ALF and healthy controls. In addition, miR­21 antagomir was injected via the tail vein into C57BL/6 mice, and lipopolysaccharide/D­galactosamine (LPS/GalN) was injected into mice after 48 h. The expression levels of miR­21, Krüppel­like­factor­6 (KLF6), autophagy­related proteins and interleukin (IL)­23, and hepatic pathology were then assessed in the liver tissue. Furthermore, THP­1­derived macrophages were transfected with a miRNA negative control, miR­21 inhibitor, miR­21 mimics or KLF6 overexpression plasmid, followed by treatment with or without rapamycin, and the expression levels of miR­21, KLF6, autophagy­related proteins and IL­23 were evaluated. The results revealed that baseline serum miR­21 levels were significantly upregulated in patients with ALF. In addition, LPS/GalN­induced ALF was attenuated in the antagomir­21 mouse group. KLF6 was identified as a target of miR­21­5p with one putative seed match site identified by TargetScan. A subsequent luciferase activity assay demonstrated a direct interaction between miR­21­5p and the 3'­UTR of KLF6 mRNA. Further experiments suggested that miR­21 promoted the expression of IL­23 via inhibiting KLF6, which regulated autophagy. In conclusion, in the present study, baseline serum miR­21 levels were highly upregulated in patients with ALF, antagomir­21 attenuated LPS/GalN­induced ALF in a mouse model, and miR­21 could promote the expression of IL­23 via inhibiting KLF6.

The intestinal microbial metabolite acetyl l-carnitine improves gut inflammation and immune homeostasis via CADM2.

Intestinal symbiotic bacteria play a key role in the regulation of immune tolerance in inflammatory bowel disease (IBD) hosts. However, the bacterial strains directly involved in this regulation and their related metabolites are largely unknown. We sought to investigate the effects of intestinal microbial metabolites on intestinal epithelium and to elucidate their therapeutic potential in regulating intestinal mucosal inflammation and immune homeostasis. Here, we used metagenomic data from Crohn's disease (CD) patients to analyze the composition of intestinal flora and identify metabolite profiles associated with disease behavior, and used the mouse model of dextran sodium sulfate (DSS)-induced colitis to characterize the therapeutic effects of the flora metabolite acetyl l-carnitine (ALC) on DSS-induced colitis. We found that intraperitoneal injection of ALC treatment could significantly alleviate the symptoms of DSS-induced colitis in mice, including prevention of weight loss, reduction in disease activity index (DAI) scores, increasing of colonic length, reduction in histological scores, and improvement in intestinal barrier function. Further, transcriptome sequencing analysis and gene silencing experiments revealed that the absence of CADM2 abolished the inhibitory effect of ALC on the TLR-MyD88 pathway in colonic epithelial cells, thereby reducing the release of inflammatory factors in colon epithelial cells. And we confirmed a significant downregulation of CADM2 expression in intestinal tissues of CD patients compared to healthy people in a population cohort. In addition, we also found that ALC increased the ratio of Treg cells in colon, and decreased the ratio of Th17 cells and macrophages, thereby improving the immune tolerance of the organism. The proposed study could be a potential approach for the treatment of CD.

The influence of sleep factors and dietary habits on the disease pattern of ulcerative colitis patients with long and short disease courses - a multicentre cross-sectional analysis.

BACKGROUND: Ulcerative colitis (UC) is a disease characterized by chronic relapsing-remitting inflammatory disorders and is associated with environmental changes. AIM: To explore the disease patterns of Chinese UC patients and to determine controllable related environmental factors. METHODS: This multicentre cross-sectional study was performed using a questionnaire survey. Data on clinical characteristics and environmental factors were collected. Patients with a disease course ≥5 years were defined as the long course group, and those with a disease course < 5 years were defined as the short course group. RESULTS: A total of 588 effective questionnaires were collected. The proportion of the chronic continuous pattern was the highest among patients with a long disease course (46.8%), and in patients with a short disease course, the proportion of the active to remission pattern was the highest (53.3%). In patients with a long disease course, a higher proportion of patients with adequate sleep was found in the active to remission pattern than in the chronic intermittent (72.1% vs. 43.3%, p = 0.008) and chronic continuous (72.1% vs. 52.4%, p = 0.016) patterns. In patients with a short disease course, the frequency of shellfish and shrimp was higher in the chronic continuous pattern group than in the active to remission pattern group (P = 0.001 and 0.017 respectively). CONCLUSIONS: For early diagnosis patients, dietary guidance should be actively carried out. With the prolongation of the disease course, attention should be given to the sleep quality of patients.

1.UC exhibits various disease patterns, which may be associated with differences in patient prognosis and treatment response.2.Environmental factors, especially sleep and dietary factors, correlated strongly with disease patterns, which varied in different disease courses.3.Early diagnosis patients should receive active dietary guidance, while patients with a prolonged disease course require attention to their sleep quality and appropriate drug interventions when necessary.