Background Salidroside (SAL) has a protective effect on multiple organ systems. Exposure to fine particulate matter (PM_2.5) in the atmosphere may lead to disruptions in gut microbiota and impact intestinal health. The regulatory effect of SAL on the gut microbiota of mice exposed to PM_2.5 requires further investigation. Objective To evaluate gut microbiota disruption in mice after being exposed to PM_2.5 and the potential effect of SAL. Methods Forty male C57BL/6 mice, aged 6 to 8 weeks, were randomly divided into four groups: a control group, an SAL group, a PM_2.5 group, and an SAL+PM_2.5 group, each containing 10 mice. In the SAL group and the SAL+PM_2.5 group, the mice were administered SAL (60 mg·kg⁻¹) by gavage, while in the control group and the PM_2.5 group, sterile saline (10 mL·kg⁻¹) was administered by gavage. In the PM_2.5 group and the SAL+PM_2.5 group, PM_2.5 suspension (8 mg·kg⁻¹) was intratracheally instilled, and in the control group and SAL group, sterile saline (1.5 mL·kg⁻¹) was intratracheally administered. Each experiment cycle spanned 2 d, with a total of 10 cycles conducted over 20 d. Histopathological changes in the ileum tissue of the mice were observed after HE staining. Colon contents were collected for gut microbiota sequencing and short-chain fatty acids (SCFAs) measurements. Results The PM_2.5 group showed infiltration of inflammatory cells in the ileum tissue, while the SAL+PM_2.5 group exhibited only a small amount of inflammatory cell infiltration. Compared to the control group, the PM_2.5 group showed decreased Shannon index (P<0.05) and increased Simpson index (P<0.05), indicating that the diversity of gut microbiota in this group was decreased; the SAL+PM_2.5 group showed increased Shannon index compared to the PM_2.5 group (P<0.05) and decreased Simpson index (P<0.05), indicating that the diversity of gut microbiota in mice intervened with SAL was increased. The principal coordinates analysis (PCoA) revealed a significant separation between the PM_2.5 group and the control group, while the separation trend was less evident among the control group, the SAL group, and the SAL+PM_2.5 group. The unweighted pair-group method with arithmetic means (UPGMA) clustering tree results showed that the control group and the SAL group clustered together first, followed by clustering with the SAL+PM_2.5 group, and finally, the three groups clustered with the PM_2.5 group. The PCoA and UPGMA clustering results indicated that the uniformity and similarity of the microbiota in the PM_2.5 group were significantly decreased. Compared to the control group, the PM_2.5 group showed decreased abundance of phylum Bacteroidetes and Candidatus_Saccharimonas (P<0.05) and increased abundance of phylum Proteobacteria, genus Escherichia, genus Bacteroides, genus Prevotella, genus Enterococcus, and genus Proteus (P<0.05). Compared to the PM_2.5 group, the SAL+PM_2.5 group showed decreased abundance of phylum Proteobacteria, phylum Actinobacteria, genus Prevotella, and genus Proteus (P<0.05), and increased abundance of Candidatus_Saccharimonas (P<0.05). The PM_2.5 group showed reduced levels of propionic acid, valeric acid, and hexanoic acid compared to the control group (P<0.05), while the SAL+PM_2.5 group showed increased levels of propionic acid, isobutyric acid, butyric acid, valeric acid, and hexanoic acid compared to the PM_2.5 group (P<0.05). Conclusion Exposure to PM_2.5 can cause pathological alterations, microbial dysbiosis, and disturbing production of SCFAs in intestinal tissue in mice. However, SAL can provide a certain degree of protective effect against these changes.

Background Hexavalent chromium [Cr(VI)] exposure can cause structural disruption of intestinal flora and functional impairment. Vitamin C (VC) is one of the essential micronutrients, which plays an important role in promoting the growth of intestinal probiotics, improving the intestinal barrier, and maintaining the homeostasis of intestinal flora. However, the regulatory effect of VC on the intestinal flora disorders caused by Cr(VI) exposure remains to be investigated. Objective To investigate the effect of VC on intestinal flora disruption in mice due to Cr(VI) exposure. Methods Thirty-two SPF-grade C57BL/6 mice were acclimatized and fed for 3 d and randomly divided into control (Con), VC, potassium dichromate [K₂Cr₂O₇, Cr(VI)], and VC+K₂Cr₂O₇ [VC+Cr(VI)] groups. At 8:00 a.m. on day 4, the Con group (double-distilled water given by gavage and injected intraperitoneally), the VC group (VC given by gavage and double-distilled water injected intraperitoneally), the Cr(VI) group (double-distilled water given by gavage and K₂Cr₂O₇ solution injected intraperitoneally), and the VC+Cr(VI) group (VC given by gavage and K₂Cr₂O₇ solution injected intraperitoneally) were treated. The dose of VC was 200 mg·kg⁻¹, and the dose of K₂Cr₂O₇ was 1.25 mg·kg⁻¹. The mice were treated for 45 consecutive days and then executed, the contents of the colon were sampled in sterile freezing tubes, and three replicates were collected from each group. After labeling, the samples were immediately put into liquid nitrogen for rapid freezing. After all the samples were collected, they were transferred to a -80 ℃ ultra-low temperature refrigerator for storage. Samples of colon contents were analyzed for intestinal flora structure by high-throughput sequencing and bioinformatics software. Results The Cr(VI) exposure resulted in reduced body weight gain values in mice compared to the Con group. Pathological changes occurred in the ileal tissue of mice, with significant inflammatory cell infiltration in the Cr(VI) group and reduced inflammatory cell infiltration in the VC+Cr(VI) group. The number of operational taxonomic units (OTUs) of intestinal flora was altered in the Cr(VI) group of mice. In the α diversity analysis, the mean Sobs index in the Cr(VI) group was 240.333±67.796, the Chao index was 258.173±64.813, and the Ace index was 259.481±66.891, which were significantly lower than those in the Con group (P<0.05), the PD whole tree index in the Cr(VI) group was 27.863±2.399, which was significantly higher than that in the Con group (P<0.05), and the VC intervention significantly reversed the changes of the above indexes due to Cr(VI) exposure (P<0.05). In the β diversity analysis, the principal coordinates analysis (PCoA) results showed a significant separation between the Cr(VI) group and the Con group, and after the VC intervention, there was a retraction of the separation trend and the difference was reduced. The multi-sample similarity dendrogram results showed that the control and the VC groups clustered together first, then with the VC+Cr(VI) group, and finally with the Cr(VI) group. The abundances of Bacteroidetes, Saccharibacteria, and Tenericutes in the intestine of mice in the Cr(VI) group were decreased, and the abundance of Firmicutes was increased; the abundances of Lactobacillus, Alistipes, Bacteroides, and Ruminiclostridium were also increased. Included among these, Bacteroides showed a significantly higher abundance compared to the control mice (P<0.05). Changes in the abundances of phyla and genera of the above mentioned gut microorganisms were reversed after the VC intervention. Conclusion Cr(VI) exposure can lead to intestinal damage and disorganization of the intestinal flora structure in mice, while VC intervention can ameliorate the above changes to a certain extent and normalize the intestinal flora structure.

Background Acute exposure to mercury chloride (HgCl₂) can cause liver damage. Whether oleanolic acid (OA) as a hepatoprotective drug can protect against liver injury induced by acute exposure to HgCl₂ and related mechanism of action remain unclear. Objective To investigate the protective effect and possible mechanism of OA on liver injury in mice caused by acute exposure to HgCl₂. Methods Forty SPF C57BL/6 male mice were randomly divided into four groups with 10 mice in each group according to body weight. The four groups were named control group, OA group (300 mg·kg⁻¹), HgCl₂ group (5 mg·kg⁻¹), and OA + HgCl₂ group (300 mg·kg⁻¹ OA + 5mg·kg⁻¹ Hgcl₂). Soybean oil and OA solution were administered intragastric once a day for two consecutive days. HgCl₂ solution was injected intraperitoneally 2 h after the second intragastric administration. Mice were sacrificed after 48 h, and their serum and liver were collected. Liver coefficient was calculated. The changes of liver structure and iron deposition were observed by hematoxylin-eosin (HE) staining and Prussian blue staining. Alanine aminotransferase (ALT), aspartate aminotransferase (AST), total superoxide dismutase (T-SOD), reduced glutathione (GSH), malondialdehyde (MDA), and tissue iron content were measured with commercial kits. Western blotting was used to detect nuclear factor erythroid-2 related factor 2 (Nrf2), heme oxygenase 1 (HO-1), glutathione peroxidase 4 (Gpx4), transferrin receptor 1 (TFR1,) and solute carrier family 7 member 11 (SLC7A11). Results The AST and ALT levels of the HgCl₂ group were (76.447±9.695) U·g⁻¹ and (98.563±24.673)U·g⁻¹, respectively, which were higher than those of the control group (P<0.05). After the OA pretreatment, the liver coefficient and the above indexes were decreased to (4.769±0.237)%, (57.086±10.087) U·g⁻¹, and (87.294±27.181)U·g⁻¹, respectively. The liver coefficient and AST level of the OA + HgCl₂ group were significantly different from those of the HgCl₂ group (P<0.05). After acute exposure to HgCl₂, the hepatocytes of mice were disordered, accompanied by inflammatory infiltration, positive blue particles appeared in Prussian blue staining of liver tissue, and the above changes in liver tissue were alleviated after the OA pretreatment. The iron content in the HgCl₂ group was (3.646±0.238) μmol·g⁻¹, which was higher than that in the control group, (2.948±0.308) μmol·g⁻¹. After the OA pretreatment, the iron content decreased to (3.429±0.415) μmol·g⁻¹. Compared with the control group, acute exposure to HgCl₂ resulted in decreased levels of GSH and T-SOD, decreased protein expression levels of Nrf2, HO-1, SLC7A11, and Gpx4, increased level of MDA, and increased protein expression level of TFR1 (P<0.05). After the OA pretreatment, all indicators were improved including increased GSH level, decreased MDA level, increased Nrf2, HO-1, and SLC7A11 protein expression levels, and decreased TFR1 protein expression level; compared with the HgCl₂ group, the differences were statistically significant (P<0.05). Conclusion Acute HgCl₂ exposure could induce liver injury in mice, and its mechanism may involve iron overload and ferroptosis. OA may alleviate the liver injury caused by acute HgCl₂ exposure by affecting iron overload and the ferroptosis-related protein expression.

Objective:Based on the analysis of case report and case series studies involving COVID-19 pregnant women in China, we aimed to discuss the updated management requirements for publication of scientific papers at hospitals in the new circumstances and context.Methods:The case report and case series studies published by domestic scholars in the early stage of COVID-19 outbreak were retrieved. Bibliometrics were used to analyze the research time, research content and research objects of the included literatures.Results:Nearly 200 cases (55%) of the 360 cases of COVID-19 pregnant women could not be clearly excluded from the possibility of repeated reporting. However, all these cases were not disclosed in the paper for possible repeated report.Conclusions:Potential repeated report problem may cause trouble for later meta-analysis, which also may have negative impact for the development of clinical guidelines. The departments of scientific research management at hospital should pay more attention to the management of patient′s data in scientific papers, so that it can better serve the accurate assessment of disease characteristics and epidemic situation, as well as the scientific formulation of clinical guidelines and control strategies.

Objective To investigate the effect of KRAS gene mutation and clinical factors on postopera-tive prognosis of rectal cancer patients and to explore their value in prognosis. Methods A total of 130 cases of rectal cancer patients from January to December 2010 were collected in the study. The tumor tissues sample was used to detect the KRAS gene mutation and 5-year follow-up was conducted. The correlation between KRAS gene mutation and clinical pathological features was analyzed.The clinic pathological factors that may affect the progno-sis were analyzed by survival analysis. Results Forty-five patients had mutations in No.2 expressed region of KRAS,with a mutation rate of 34.6%.KRAS gene mutation and stronger positive expression of EGFR(P<0.05), and multiple metastasis of tumor(P<0.05)were strongly coupled.The average survival of patients with wild-type KRAS gene was 57.5 months and that of patients with KRAS gene mutation 58.9 months but no significant differ-ence was observed(P>0.05).The TNM by high staging,multiple metastasis,lung metastasis and liver metasta-sis of cancer cells was closely related with poor postoperative prognosis of patients(P<0.05).The average surviv-al of postoperative patients in stage Ⅳ was 49months. Conclusions KRAS gene mutation in patients with rectal cancer after surgery is related with stronger positive expression of EGFR and multiple metastasis of cancer.TNM by high staging and metastatic sites affects the prognosis. The survival of rectal cancer after surgery in patients with stage Ⅳ are prolonged but the relation between KRAS genovariation and patients′ postoperative prognosis can not be determined.

Objective To analyze the difference of salivary microbiome between the patients with functional dyspepsia and healthy controls.Methods Saliva samples were collected from the patients with functional dyspepsia and healthy control.Genomic DNA of the samples was extracted,and the high-throughput sequencing technology was used to conduct DNA sequence of 16S rRNA-V4 region.Subsequently,all the data were performed by the bioinformatic analysis.Results The salivary microbiome in the functional dyspepsia group was dominated by Proteobacteria,while Bacteroidetes was the top microbiota in the heathy control group.In the functional dyspepsia group,the Chao1 index,ACE index,Shannon index and Simpson index were 1 295,1 351,4.93 and 0.90 respectively.In the healthy control group,the above indexes were 1 001,1 351,5.28 and 0.92 respectively.The PCoA ba sically separated the microbiome composition of the two groups.Sixteen kinds of microbiota were significantly different between two groups using linear discriminant analysis effect size tool,including Bacteroidetes,Prevotella,Prevotellaceae,Neisseria,Betaproteobacteria and Proteobacteria,etc.Conclusion Saliva in the patients with functional dyspesia has characteristic microbiome composition,which is dominated by Proteobacteria,but the richness and diversity between the two groups have no difference.Neisseria is one of the significantly different bacteria between the two groups.

Objective To analyze the diversity of salivary bacteria in patients with nonalcoholic fatty liv-er disease(NAFLD group)and healthy control group(HC group). Methods Saliva samples were collected from 24 patients with nonalcoholic fatty liver disease and 22 healthy control.Genomic DNA of the samples was extracted and extended to 16S rRNA V4-V5 hypervariable region after PCR with Illumina high-throughput sequencing tech-nology.All the data,including operational taxonomic units,diversity indexes and species annotation,etc.was ana-lyzed. Results 39118 optimized sequences in the saliva of each group were obtained,including nonalcoholic fatty liver group clustering OTUs about 308 ± 48 and healthy control group clustering OTUs about 305 ± 53.The diversi-ty analysis of NAFLD group and HC group showed that there was little difference in diversity of the whole salivary bacteria.The data of the species analysis of the saliva bacteria in two group indicate that the composition was simi-lar and the relative abundance was different in phylum and genus.In NAFLD group,the ratio of the abundance of firmicutes(20.42%)increased and the proportion of bacteroides(36.75%)decreased in phylum. Genus of the NAFLD group,the ratio of fusobacterium,porphyromonas and veillonella increased significantly,and the ratio of prevotella and[Prevotella]decreased.Conclusion In the NAFLD group,the abundance of firmicutes increased, and the abundance of the bacteria decreased.It was speculated that the imbalance of the salivary bacteria is associ-ated with nonalcoholic fatty liver disease.

Objective To explore the mediating effects of resilience between family function and geriatric depression. Methods By convenient sampling, 212 elderly people who were from the communities in Yuexiu, Guangxhou city were analyzed by using Geriatric Depression Scale (GDS-30) and Family Concern Index Questionnaire (APGAR) and Connor-Davidson Resilience Scale (CD-RISC) and the self-designed General Condition Questionnaire, and a mediating model was proposed and the impacts of resilience on family function and geriatric depression were tested. Results The incidence rate of depression among the community elderly was 23.6% (50/212), and the average score of APGAR was 7.87 ± 2.83, and the average score of CD-RISC was 83.66 ± 12.88. The scores of GDS-30 showed significantly negative correlation with the scores of APGAR (r=-0.582,P<0.01)and the scores of CD-RISC (r=-0.425, P<0.01), and there was positive correlation between the scores of APGAR and the scores of CD-RISC (r=0.335, P < 0.01). The mediating model had high degree of fitting, and level of path had statistical significance (P < 0.01). Resilience was the mediator between family function and geriatric depression. Family function had direct effects (0.50) on geriatric depression and indirect effects (0.11) through resilience, and the combined effects of family function and resilience determined 45%changing range of geriatric depression. Conclusions Family function was a direct predictor of geriatric depression, and resilience had mediating effects between family function and geriatric depression. Community mental health work should pay enough attention to the effects of family function on the life of the aged, and increased the care to the elderly with family dysfunction, while promote and develop family-centered mental health education, propaganda and psychological guidance, so that improves resilience of the aged and help the aged positively coping and maintain good mental health status.

Objective To compare sedated water exchange and conventional colonoscopy in the recovery time,rates of reaching ileocecal valve and adenoma detection.Methods A total of 200 newly diagnosed patients undergoing colonoscopy with routine bowel preparation and propofol intravenous anesthesia were randomly divided into 2 groups:water exchange group (WE) and conventional group,100 patients in each group.The operations were performed by two experienced physicians.The recovery time,rates of reaching ileocecal valve and adenoma detection of each group were analyzed and compared after operation.Results The recovery times of patients in water exchange and conventional groups were 8.08±0.58 min and 12.34±0.72 min,respectively (F =2 147.33,P＜ 0.05).Rates of reaching ileocecal valve were 100.00％(100/100,WE group) and 96.00％ (96/100,conventional group),respectively(x2 =4.17,P＜0.05).Adenoma detection rates of whole colon were 43.00％ (43/100,WE group) and 29.00％ (29/100,conventional group) (x2=4.25,P＜0.05),of which small adenomas (＜ 1.0 cm) accounted for 83.96％ (89/106,WE group) and 70.59％ (48/68,conventional group) (x2 =4.43,P ＜ 0.05),respectively.Adenoma detection rates of proximal colon were 28.00％ (28/100,WE group) and 20.00％ (20/100,conventional group) (x2 =1.75,P＞ 0.05),of which small adenomas (＜ 1.0 cm) accounted for 90.41％ (66/73,WE group) and 74.47％ (35/47,conventional group) (x2 =5.45,P ＜ 0.05),respectively.Conclusion Water exchange colonoscopy can not only shorten the recovery time of patients,but also increase rates of reaching ileocecal valve and adenoma detection.

BACKGROUND:Conditioned medium from mesenchymal stem cels (MSC-CM) that contains abundant MSCs paracrine substances may represent a promising alternative to MSCs transplantation. However, normal MSC-CM with insufficient paracrine ability is not effective for tissue damage repair. OBJECTIVE:To investigate the effects of MSC-CM with (MSC-CMHyp) and without hypoxic activation (MSC-CMNor) on the proliferation and apoptosis of radiation-induced injured intestinal epithelial cels (IEC-6) and to further discuss the paracrine mechanisms. METHODS: IEC-6 cels were exposed to 10 Gy irradiation and cultured in MSC-CMHyp, MSC-CMNor, and DMEM-F12 medium, respectively. RESULTS AND CONCLUSION: Findings from trypan blue staining, flow cytometry and western blot assay showed that, compared with the DMEM-F12 medium group, treatment with MSC-CMHyp significantly enhanced IEC-6 viability proliferation after radiation-induced injury, as wel as significantly decreased cel apoptosis and expression of Caspases-3/8 (P < 0.05). However, there was no significant difference between the MSC-CMNor group and DMEM-F12 medium group (P > 0.05). On the other hand, the increased levels of vascular endothelial growth factor, basic fibroblast growth factor, insulin-like growth factor-1, and interleukin-10 were detected in the MSC-CMHyp group compared to the MSC-CMNor group (P < 0.05). These results suggest that the MSC-CMHyp improves the viability and proliferative capacity of IEC-6 cels after radiation-induced injuryvia up-regulating secretion of cytokines and down-regulating apoptotic signaling.