[Clinicopathological characteristics of rectal neuroendocrine neoplasms].

Objective: Clinicopathological characteristics of neuroendocrine neoplasms are highly heterogeneous based on variable origins.Our study aims to explore the clinical features of rectal neuroendocrine neoplasm (RNEN). Methods: Patients with histologically diagnosed rectal neuroendocrine neoplasms were retrospectively analyzed between January 2012 and December 2020. Epidemiological characteristics, clinical manifestations, complete blood count, endoscopy findings, and pathological features were recorded and analyzed. T-test was used for measurement data analysis, Chi-square test was performed for classification data analysis, and Binary logistic regression was applied for analyzing risk factors of metastasis. Results: Among 172 patients, the male to female ratio was 107 to 65 with an average age of (52±12) years (16-77 years). Altered bowel habit was the most common initial symptom (58/172, 33.7%), followed by abdominal pain (36/172, 20.9%) and loss of body weight (27/172, 15.7%). One hundred and sixty-one cases were neuroendocrine tumors, 9 were neuroendocrine carcinomas and 2 were mixed neuroendocrine-non-neuroendocrine neoplasms. Most endoscopic presentations were polypoid lesions (147/172, 85.5%), mainly limited to mucosa (48/172, 27.9%) and submucosa (96/172, 55.8%). Twenty-nine patients developed lymph node invasion or distant metastasis at diagnosis. There were statistical difference of neutrophil-to-lymphocyte ratios (NLR) among groups with different tumor size (<10 mm vs. 10-20 mm vs.>20 mm, mean NLR 1.79±0.55 vs. 2.27±1.23 vs. 2.95±0.66, P<0.01. Compared with non-metastatic group, the metastatic group presented higher NLR(2.61±0.81 vs. 1.89±0.80, P<0.01). Tumor size (<10 mm vs. 10-20 mm vs.>20 mm, OR 1.00 vs. 2.10 vs. 5.25×109, P =0.001), invasion to bowel wall (mucosa vs. submucosa vs. muscularis vs. serosa invasion,OR 1.00 vs. 3.26 vs. 14.11 vs. 39.42, P=0.008), and NLR (NLR<2.25 vs. NLR≥2.25, OR 1.00 vs. 5.19, P =0.024) were risk factors for metastasis. Conclusion: Metastasis of RNEN is related with tumor size, degree of bowel invasion and NLR. High NLR is a poor prognostic factor of RNEN.

[Effect of VSL#3 and S.Boulardii on intestinal microbiota in mice with acute colitis].

Objective: To investigate the effects of probiotics(VSL#3, S. Boulardii) on intestinal flora of mice with DDS-induced acute colitis. Methods: C57BL/6J mice were administered with 2.5% dextran sulfate sodium for 5 consecutive days to develop the acute colitis model except for the blank control group. Meantime,Mice were treated with drinking water (DSS model group),VSL#3 (1.5×10(9) CFU),or S.Boulardii(5×10(7) CFU) by gavage for 7 days respectively,and mice were sacrificed 2 days after the model of colitis was established. The fecal specimens before gavage (day 0),in the middle of experiment (day 4),and the end of gavage (day 7) and the intestinal mucosa after sacrifice were collected to analyze the differences between these four groups by 16s rDNA sequencing method. Results: Compared with the DSS model group, VSL#3 group showed a decrease in disease activity index (DAI) and histological scores, and there was no significant change in the S.Boulardii group. Fecal microbiota:in the middle of experiment,the alpha diversity of DSS model group,VSL#3 group and S.Boulardii group were lower than that of the blank control group(P=0.0135,P=0.0018,P=0.0151). After the end of gavage,the diversity of the VSL#3 group was lower than that of the blank control group(P=0.025), and the difference between any other two groups was not statistically significant. Mucosa-adherent microbiota:biodiversity of DSS model group,S.Boulardii group were lower than the blank control group(P=0.031,P=0.0437),while biodiversity of VSL#3 group was higher than DSS model group and S. Boulardii group(P=0.0394, P=0.0426). Compared with the blank control group, the DSS model group showed an increase in Bacteroides and a decrease in Lactobacillus. Abundance in the genus Turicibacter and Odoribacter increased in intestinal microbiota of mice with acute colitis, while VSL#3 inhibited them. Conclusions: VSL#3 alleviates inflammation in DSS-induced colitis of mice.Both VSL#3 and S.Boulardii can affect intestinal microbiota. Compared with healthy mice,mice with colitis showed a reduced diversity of microbiota both in feces and in intestinal mucosa. VSL#3 increases biodiversity of mucosal microbiota in mice with acute colitis,while it does not increase biodiversity of fecal microbiota. Genera such as Turicibacter and Odoribacter increase in mice with acute colitis, and these genera can be inhibited by VSL#3.