Gastrointestinal tract contains a wide variety of host-specific microbial communities that not only adapt to the unique and diverse environment in the stomach and intestine, but also respond quickly to all kinds of variants from outside of the body. A series of biochemical signals are occurred for interacting with the host to coordinate the exchange of nutrients and regulate the immune function. The interaction between host and microorganisms is based on homeostasis; dysbiosis of intestinal microbiota contributes to the initiation and development of diseases. The relationship between microbes and host from the perspective of microecology, and the relationship between intestinal microecology and digestive system diseases were summarized in this article.

Objective: To screen the differentially expressed proteins in clear cell renal cell carcinoma (ccRCC), and to investigate its clinical significance. Methods: The differentially expressed proteins in 15 cases of ccRCC and their adjacent renal tissues were screened by two-dimensional fluorescence difference in gel electrophoresis combined with mass spectrometry (2-D DIGE-MS). The expression levels of differentially expressed proteins screened by 2-D DIGE-MS in 45 cases of ccRCC and their adjacent tissues were examined by Western blotting. The expression levels of this differentially expressed proteins in 152 specimens of ccRCC and 40 specimens of adjacent tissues were detected by immunohistochemistry. The correlations of this protein expression with the clinicopathologic features and prognosis of ccRCC patients were analyzed. Results: Proteomics screening results showed that the expression level of peroxiredoxin 4 (PRDX4) was significantly different in ccRCC and its adjacent tissues; compared with the adjacent tissues, PRDX4 expression was significantly down-regulated in ccRCC tissues (P < 0.05); and the expression level of PRDX4 in the adjacent tissues was 3.979 times higher than that in ccRCC tisseus. Western blotting showed that the expression level of PRDX4 in ccRCC tissues was significantly lower than that in adjacent tissues (t = 12.810, P < 0.001). Immunohistochemistry showed that the positive expression rate of PRDX4 in ccRCC tissues was significantly lower than that in the adjacent tissues [36.8% (56/152) vs 87.5% (35/40), ?2 = 32.594, P < 0.001]. Furthermore, the expression level of PRDX4 was correlated with tumor grade (?2 = 6.802, P = 0.033) and distant metastasis (?2 = 3.925, P = 0.048), but was not related to gender, age, T stage, lymph node metastasis and recurrence (all P > 0.05). The patients with lower expression of PRDX4 had high grade of ccRCC (? = -0.211, P = 0.009) and distant metastasis (? = -0.161, P = 0.048). The 5-year survival rates of patients with positive and negative expression of PRDX4 were 75.3% and 62.7% (P = 0.862), respectively. Conclusion: PRDX4, as a differentially expressed protein in ccRCC, may be involved in the formation and development of renal cancer, and its down-regulation is correlated with the increased malignancy of ccRCC.

The mechanism of triggering and maintaining atrial fibrillation (AF) is still not clear. There are different understandings about triggering and maintenance of AF, and therapeutic strategies relevant to them could not reach an agreement. In recent years, basic researches on AF have made greater progress. For example, the atrial rotor and autonomic nerve plexus theories has also been identified clinically, and it changed the strategies of radiofrequency ablation treatment for AF. This article summarizes the mechanism and current status of AF ablation.

CD44 is a widely distributed cell-adhesion molecule that participates in a number of biological events. CD44 is proteolytically cleaved by other enzymes and the level of its proteolysis is correlated to the cell activity. The CD44-proteolytic peptides including soluble CD44 and CD44 intracellular domain have different functions in cell events. In recent years, a number of researches found the functions of CD44-proteolytic peptides. In this review, the release of CD44-proteolytic peptides and their functions of these peptides were summarized.
Hyaluronan Receptors ; metabolism ; Hydrolysis

Background: Clostridium difficile infection (CDI) is the most commonly seen opportunistic infection. Although antibiotic therapy is the first-line treatment, there are still some problems existed such as poor therapeutic effect, recurrence of infection and recrudescence. Therefore, it is necessary to develop new anti-infectious drugs. Aims: To explore the possible intervention effect of SR1001 on CDI and its potential mechanism, and to explore its potential intervention targets. Methods: Clostridium difficile (C. difficile) was cultured with HT-29 cells, and were divided into control group, CDI group (infected with C. difficile) and SR1001 treatment group (infected with C. difficile+SR1001 treatment). Morphological changes of HT-29 cells were observed. Cell proliferation was detected by CCK-8 assay, expression of PI3K/AKT/mTOR signaling pathway was detected by Western blotting, and TcdB content in the cell supernatant was detected by ELISA. Results: Compared with the control group, cells in CDI group became brighter and rounder, apoptosis was obvious, cell proliferation ability was significantly decreased (P<0.05), and inhibition of cell proliferation increased with the extension of time; the expressions of PI3K/AKT/mTOR pathway phosphorylated proteins and the content of TcdB in the supernatant were significantly increased (P<0.05). After SR1001 treatment, the cells tended to be in normal 'paving stone'-like arrangement, apoptosis was improved, cell proliferation ability was significantly increased than in CDI group, and expressions of PI3K/AKT/mTOR pathway phosphorylated proteins and TcdB content in the supernatant were significantly decreased. Conclusions: SR1001 can reverse the effect of C. difficile on growth of colon cancer cells by interfering the phosphorylation of PI3K/AKT/mTOR pathway.

Objective: To study and analyze the effect of applying the knowledge, attitude/belief, and practice (KAP) nursing mode in caring for patients who receive fixed orthodontic treatment. Methods : A total of 112 patients who received orthodontic treatment were selected as study subjects. They were randomly divided into an observation group and a control group, with 56 patients in each group. Patients in the control group were treated with conventional oral care, while those in the observation group were treated with the KAP nursing mode. The patients’ awareness of the disease, treatment compliance, and orthodontic complications were compared between the two groups. Results : After treatment with the KAP nursing mode, the disease cognition score was significantly higher in the observation group than in the control group (P < 0.05). Patient compliance was better in the observation group than in the control group throughout the treatment. Patients in the observation group were more able to return to the hospital on time than those in the control group. The orthodontic plaque index (OPI) of patients in the observation group decreased during the treatment. The OPI of patients in the observation group was significantly lower than that of patients in the control group at 6 months (t=2.344) and 12 months (t=3.721) after the start of the treatment (P < 0.05), and the incidence of orthodontic complications in the observation group was 7.1% (4/56), significantly lower than that in the control group (26.9% (15/56); χ2=9.728, P < 0.05). Conclusion Application of the KAP nursing mode can effectively reduce the incidence of complications in patients with fixed orthodontics, improve the oral health of patients, and positively affect orthodontic treatment.

OBJECTIVE: Use cadavers and three-dimensional MRA models to study the anatomical relationship between the sacrospinous ligament(SSL)and its adjacent vessels and nerves.METHODS: Totally 24 female cadavers provided by Anatomy Department of Southern Medical University from September 2017 to September 2018 were dissected,and 30 MRA data collected by Gynecology Department of Nanfang Hospital of Southern Medical University from January 2015 to December 2018 were selected to reconstruct to measure the relevant application parameters.RESULTS: The medial structure of the pudendal canal was the pudendal nerve,and the horizontal distance between the right pudendal nerve and the sciatic spine was(1.51 ± 0.35)cm. The thickness of the thickest point of the right coccygeus-sacrospinousligament(CSSL)was(1.03±0.23)cm and the horizontal distance between the point and the right sciatic spine was(2.81±0.55)cm;the vertical distance from where the right inferior gluteal artery is out of pelvis cavity to the horizontal line of sciatic spine was(2.43±0.95)cm,and the distance between the vertical point and the sciatic spine was(1.83±0.83)cm. In anatomy and MRA model,none of the inferior gluteal artery went dorsally through the SSL,and the sciatic nerve was away from the SSL.There was no obvious vascular nerve traveling on the pelvic surface of SSL.CONCLUSION: The point which is 2.81 cm away from the right sciatic spine of the SSL at the horizonal level may be the best suspension point for SSLF.

OBJECTIVE: To explore the clinicopathological features and types of genic mutations in DNA mismatch repair (MMR) in colorectal cancer (CRC). METHODS: Immunohistochemistry was used to determine the expression of MMR proteins in 1394 patients with CRC, and PCR-capillary electrophoresis (PCR-CE) was used to detect microsatellite instability (MSI) in 106 cases of defective MMR (dMMR), 46 cases of proficient MMR (pMMR) with heterogeneous expression and 147 randomly selected cases of pMMR. The relationship between the expressions of MMR proteins and the clinicopathological features of the patients was evaluated. The consistency between the results of immunohistochemistry and PCR-CE was assessed. RESULTS: Immunohistochemical staining showed an incidence of dMMR of 7.6% in the patients. The main type of dMMR was co-deletion of MLH1 and PMS2, accounting for 55.7% of the total dMMR cases. The deletion of MMR proteins was significantly correlated with the patients' age, tumor location, tumor size, gross type, histological type, degree of differentiation, lymph node status and TNM stage ( CONCLUSIONS The main type of dMMR is co-deletion of MLH1 and PMS2 in patients with colorectal cancer. dMMR colorectal cancer has typical clinicopathological features and a lower incidence in China than in Western countries. The results of immunohistochemistry and PCR-CE are highly consistent for detecting dMMR in colorectal cancer patients.
China ; Colorectal Neoplasms/genetics* ; DNA Mismatch Repair/genetics* ; Humans ; Microsatellite Instability

OBJECTIVE: To explore the molecular mechanisms of Porphyromonas gingivalis infection-induced umbilical vein endothelial barrier dysfunction in vitro. METHODS: Human umbilical vein endothelial cells (HUVECs) were cultured in vitro, and after the formation of the endothelial barrier, the cells were infected with P. gingivals at a multiplicity of infection (MOI). The transepithelial electrical resistance (TEER) of the cell barrier was measured, and FITC-dextran trans-endothelial permeability assay and bacterial translocation assay were performed to assess the endothelial barrier function. The expression levels of cell junction proteins including ZO-1, occludin and VE-cadherin in the cells were examined by qRT-PCR and Western blotting. RESULTS: In freshly seeded HUVECs, TEER increased until reaching the maximum on Day 5 (94 Ωcm²), suggesting the formation of the endothelial barrier. P. gingivals infection caused an increase of the permeability of the endothelial barrier as early as 0.5 h after bacterial inoculation, and the barrier function further exacerbated with time, as shown by significantly lowered TEER, increased permeability of FITC-dextran (40 000/70 000), and increased translocation of SYTO9-E. coli cross the barrier. MTT assay suggested that P. gingivals infection did not significantly affect the proliferation of HUVECs (P>0.05), but in P. gingivalsinfected cells, the expressions of ZO-1, occludin and VE-cadherin increased significantly at 24 and 48 h after bacterial inoculation (P < 0.05). CONCLUSION P. gingivals may disrupt the endothelial barrier function by down-regulating the expressions of the cell junction proteins (ZO-1, occludin, VE-cadherin) and increasing the permeability of the endothelial barrier.
Humans ; Cadherins/metabolism* ; Escherichia coli/metabolism* ; Human Umbilical Vein Endothelial Cells/metabolism* ; Occludin ; Porphyromonas gingivalis/metabolism* ; Umbilical Veins/metabolism*

ObjectiveTo investigate the efficacy of transjugular intrahepatic portosystemic shunt （TIPS） in preventing rebleeding in patients with hepatocellular carcinoma （HCC） comorbid with esophagogastric variceal bleeding and the influencing factors for prognosis. MethodsA retrospective analysis was performed for the clinical data of 35 HCC patients comorbid with esophagogastric variceal bleeding who were admitted to Zengcheng Branch of Nanfang Hospital， Southern Medical University， and were treated with TIPS from July 2019 to April 2023. The Kaplan-Meier curve was used to assess rebleeding rate and survival rate after TIPS， and the Cox regression model was used to investigate the influencing factors for postoperative rebleeding and survival. ResultsThe TIPS procedure was technically successful in all patients， with a median follow-up time of 16.4 months. During follow-up， 11 patients （31.4%） experienced esophagogastric variceal rebleeding， with the 1-month， 3-month， and 1-year rebleeding rates of 5.7%， 17.1%， and 28.6%， respectively. White blood cell count （WBC） （risk ratio ［HR］=1.31， 95% confidence interval ［CI］： 1.04 ‍—‍ 1.64， P=0.021）， number of tumors ≥3 （HR=35.68， 95%CI： 1.74 ‍—‍ 733.79， P=0.021）， and portal pressure gradient before TIPS （HR=0.85， 95%CI： 0.73 ‍—‍ 0.99， P=0.032） were independent predictive factors for rebleeding after TIPS. Shunt dysfunction was observed in 5 patients after surgery. A total of 19 patients died during follow-up， with a median survival time of 9.6 months. Portal vein tumor thrombosis （PVTT） （HR=7.04， 95%CI： 1.31 ‍—‍ 37.78， P=0.023）， total bilirubin （TBil） （HR=1.02， 95%CI： 1.00 ‍—‍ 1.03， P=0.042）， and serum albumin （HR=0.82， 95%CI： 0.72 ‍—‍ 0.94， P=0.004） were independent predictive factors for survival after TIPS. ConclusionTIPS procedure can be used as a therapeutic option to prevent esophagogastric variceal rebleeding in patients with HCC. Patients with a relatively high level of WBC or TBil or those with PVTT tend to have a poorer prognosis， and the application of TIPS treatment in such patients should be determined with caution.