In vivo pilot study into superficial microcirculatory characteristics of colorectal adenomas using novel high-resolution magnifying endoscopy with blue laser imaging.

BACKGROUND: No studies have yet been conducted on changes in microcirculatory hemodynamics of colorectal adenomas in vivo under endoscopy. The microcirculation of the colorectal adenoma could be observed in vivo by a novel high-resolution magnification endoscopy with blue laser imaging (BLI), thus providing a new insight into the microcirculation of early colon tumors. AIM: To observe the superficial microcirculation of colorectal adenomas using the novel magnifying colonoscope with BLI and quantitatively analyzed the changes in hemodynamic parameters. METHODS: From October 2019 to January 2020, 11 patients were screened for colon adenomas with the novel high-resolution magnification endoscope with BLI. Video images were recorded and processed with Adobe Premiere, Adobe Photoshop and Image-pro Plus software. Four microcirculation parameters: Microcirculation vessel density (MVD), mean vessel width (MVW) with width standard deviation (WSD), and blood flow velocity (BFV), were calculated for adenomas and the surrounding normal mucosa. RESULTS: A total of 16 adenomas were identified. Compared with the normal surrounding mucosa, the superficial vessel density in the adenomas was decreased (MVD: 0.95 ± 0.18 vs 1.17 ± 0.28 µm/µm2, P < 0.05). MVW (5.11 ± 1.19 vs 4.16 ± 0.76 µm, P < 0.05) and WSD (11.94 ± 3.44 vs 9.04 ± 3.74, P < 0.05) were both increased. BFV slowed in the adenomas (709.74 ± 213.28 vs 1256.51 ± 383.31 µm/s, P < 0.05). CONCLUSION: The novel high-resolution magnification endoscope with BLI can be used for in vivo study of adenoma superficial microcirculation. Superficial vessel density was decreased, more irregular, with slower blood flow.

Mesenteric adipose tissue B lymphocytes promote intestinal injury in severe acute pancreatitis by mediating enteric pyroptosis.

BACKGROUND: Visceral adipose tissue (VAT) has been linked to the severe acute pancreatitis (SAP) prognosis, although the underlying mechanism remains unclear. It has been reported that pyroptosis worsens SAP. The present study aimed to verify whether mesenteric adipose tissue (MAT, a component of VAT) can cause secondary intestinal injury through the pyroptotic pathway. METHODS: Thirty-six male Sprague Dawley (SD) rats were divided into six different groups. Twelve rats were randomly divided into the SAP and control groups. We monitored the changes of MAT and B lymphocytes infiltration in MAT of SAP rats. Twelve SAP rats were injected with MAT B lymphocytes or phosphate buffer solution (PBS). The remaining twelve SAP rats were first injected with MAT B lymphocytes, and then with MCC950 (NLRP3 inhibitor) or PBS. We collected blood and tissue samples from pancreas, gut and MAT for analysis. RESULTS: Compared to the control rats, the SAP group showed inflammation in MAT, including higher expression of tumor necrosis factor (TNF-α) and interleukin-6 (IL-6), lower expression of IL-10, and histological changes. Flow cytometry analysis revealed B lymphocytes infiltration in MAT but not T lymphocytes and macrophages. The SAP rats also exhibited intestinal injury, characterized by lower expression of zonula occludens-1 (ZO-1) and occludin, higher levels of lipopolysaccharide and diamine oxidase, and pathological changes. The expression of NLRP3 and n-GSDMD, which are responsible for pyroptosis, was increased in the intestine of SAP rats. The injection of MAT B lymphocytes into SAP rats exacerbated the inflammation in MAT. The upregulation of pyroptosis reduced tight junction in the intestine, which contributed to the SAP progression, including higher inflammatory indicators and worse histological changes. The administration of MCC950 to SAP + MAT B rats downregulated pyroptosis, which subsequently improved the intestinal barrier and ameliorated inflammatory response of SAP. CONCLUSIONS: In SAP, MAT B lymphocytes aggravated local inflammation, and promoted the injury to the intestine through the enteric pyroptotic pathway.

Efficacy and safety of fecal microbiota transplantation for the induction of remission in active ulcerative colitis: a systematic review and meta-analysis of randomized controlled trials.

Background: Fecal microbiota transplantation (FMT) is a novel management strategy for ulcerative colitis (UC). However, its effectiveness remains controversial. This study sought to assess the effectiveness of FMT in the treatment of active UC by performing a meta-analysis of randomized controlled trials (RCTs). Methods: We searched the Cochrane, Embase, PubMed, and Web of Science databases from their inception to December 2021. RCTs that recruited patients with active UC and treated them with FMT, a placebo or a suitable comparator were included in the meta-analysis. PICOS: Patients, active UC; Intervention, FMT; Control, placebo or a suitable comparator; Outcomes, remission rate; Studies, RCTs. The risk of bias assessment was performed with Revised Cochrane risk-of-bias tool (version 2). Meta-analyses of risk ratios (RRs) were performed to estimate the differences in remission rates and the risk of serious adverse events (SAEs) between the FMT-treated and control patients. Results: A total of 9 RCTs comprising 425 UC patients (213 FMT and 212 control) were included in the meta-analysis. The risk of bias was low in these RCTs. Clinical remission was observed in 86 of the 213 patients in the FMT groups and 47 of the 212 patients in the control groups [RR: 1.84; 95% confidence interval (CI): 1.37, 2.47; P<0.0001]. Clinical remission was better when the FMT delivery route was via the lower gut, the FMT dose was >300 grams, and the fecal specimen from multiple donors. Endoscopic remission (observed in 7 RCTs) was achieved in 33 of the 195 FMT-treated patients compared to 17 of the 194 control patients (RR: 1.94; 95% CI: 1.14, 3.31; P=0.01). SAEs were reported in 22 of the 213 FMT-treated patients but only 11 of the 212 control patients (RR: 2.05; 95% CI: 1.03, 4.09; P=0.04). Discussion: FMT is an effective treatment for patients with active UC. Significantly higher clinical and endoscopic remission rates are observed with FMT than with control treatments. However, FMT may cause a significantly higher incidence of SAEs than control treatments. Future studies should delineate the effects of donor selection, dosage, delivery route, and antibiotic pretreatment and should evaluate the safety profile of FMT.