Objective To investigate the role and mechanism of SDF-1/CXCR4 in the development of chronic rejection (CR) in rat models.Methods CR rat models were established using Fisher 344 to Lewis rats.In the blank control group (n=10),Lewis rats getting isotransplantation were treated with Cyclosporine A.CR rat models were established in positive group (n=10) and the rats were treated with Cyclosporine A.CR rat models were also established in CXCR4 antagonism group (n=10) and the rats were treated with both Cyclosporine A and AMD3100 (1 mg/kg).The serum creatinine levels were monitored every week.Kidney grafts were harvested 12 weeks after transplantation for histological analysis.We evaluated graft injuries using chronic allograft damage index (CADI) scores.Q-PCR and Western blotting were used to measure CXCR4,TGF-β1/Smad3 signaling pathway and α-smooth muscle actin (α-SMA) expression in renal allograft tissues.Results The serum creatinine levels in blank control group and CXCR4 antagonism group were significantly lower than those in positive control group (P<0.05).The blank control group and CXCR4 antagonism group presented milder pathological manifestations of CR.The CADI score in CXCR4 antagonism group was 3.54,which was lower than that of positive control group (P<0.05).The expression of biological markers in TGF-β1/Smad3 signaling pathway and SDF-1/CXCR4 signaling pathway was significantly lower in blank control group and CXCR4 antagonism group than in positive control group (P<0.05).Conclusion SDF-1/CXCR4 signaling pathway may play a crucial role in the development of CR.The usage of SDF-1/CXCR4 antagonist can protect renal allograft by inhibiting the TGF-β1/Smad3 pathway.Therefore,antagonism of CXCR4 may provide a novel way to prevent the development of CR.

Objective:To investigate the effect and mechanism of short-chain fatty acids (SCFAs) on the side-effect of tacrolimus on blood glucose.Methods:The C57BL/6 mice were treated with tacrolimus orally (10 mg/kg, tacrolimus group), tacrolimus plus 150 mmol/L sodium butyrate and isovalerate mixed solution (SCFAs group), broad-spectrum antibiotics (antibiotic group), and tacrolimus plus broad-spectrum antibiotics (tac&abx group). After 8 weeks intervention, the fasting blood glucose (FBG), oral glucose tolerance test (OGTT), hemoglobin A1C (HbA1c) were tested as indicators of glucose metabolism, and the gut microbiota, SCFAs concentration in the ileocecal, serum glucagon-like peptide-1 (GLP-1), fasting serum insulin, and GLP-1 expression in intestinal mucosa were performed for intestinal-glucose metabolism mechanism.Results:The FBG and HbA1c were significantly increased in tacrolimus group[(7.31±0.97)mmol/L, (8.34±1.12)%] than control group [(5.23±0.30)mmol/L, (4.32±0.80)%, all P<0.05], which remained normal in antibiotic group [(4.92±0.31)mmol/L, (5.61±0.98)%)], tac&abx group[(5.95±0.37)mmol/L, (4.56±0.26)%] and SCFAs groups [(5.87±0.68)mmol/L, (5.07±1.79)%]. The OGTT in the tacrolimus group showed glucose tolerance impairment, while other groups remained normal. The ileocecal butyric acid and isovaleric acid concentrations in the tacrolimus group were (722.3±262.2) μg/g and (10.0±5.1)μg/g, lower than the control group[ (1 321.3±165.5) μg/g, (19.7±3.6)μg/g, P<0.05]. The above acids in the SCFAs group remained normal as in the control group [(1 375.7±451.6) μg/g, (24.5±11.5)μg/g)]. The fasting serum insulin in the tacrolimus group decreased significantly to (3.2 ± 0.6)mIU/L, compared with control[ (4.4±0.9) mIU/L]and SCFAs groups [(7.0±1.1) mIU/L]. The GLP-1 test indicated a significant decrease in the tacrolimus group[ (4.7±2.9)pg/ml, P<0.05] compared with the SCFAs group and control group [(42.5±19.9) pg/ml, (33.1±9.1) pg/ml]. Conclusions:Tacrolimus affects glucose metabolism through the SCFAs-associated GLP-1 pathway in the intestine, and oral supplementation with mixed SCFAs provides a new insight for the prevention and treatment of tacrolimus-induced hyperglycemia in transplant recipients.

Objective:To investigate the application value of MRI in evaluating the disorders of pelvic floor in female stress urinary incontinence (SUI).Methods:From January 2017 to January 2019, the patients in the SUI group and the control group of Beijing Chaoyang Hospital, Capital Medical University were prospectively collected. Some patients in the SUI group were treated with tension-free vaginal tape (TVT). The dynamic MR was performed in both SUI patients and volunteers, and the following functional MR parameters were assessed between two groups: the urethral length and urethral hypermobility; the opening of urethral and bladder neck; and the pelvic organ prolapse. For SUI patients, the functional changes of the pelvic floor on MRI after TVT was also analyzed. Chi-square test, rank-sum test and t test were used. Results:Comparing with the control groups ( n=25), the urethral hypermobility, shortening functional urethral length, bladder neck funneling and urethra opening were significantly associated with SUI group ( n=33). Thirty one patients were treated with TVT, 12 of them were reexamined with MRI at 3 to 6 months after operation. Postoperative MR showed that SUI patients had lower risk of the urethral opening and bladder neck funneling ( P<0.05). There were significant differences in the length of functional urethra, angle of urethra movement, H-line, M-line, bladder funnel sign, urethra opening and bladder prolapse between the two groups ( P<0.05). There was a significant difference between the bladder funnel sign and urethra open sign before and after TVT ( P<0.05). There was no significant difference in the degree of bladder prolapse and uterus prolapse, length of urethra and angle of urethra movement between the two groups ( P>0.05). Conclusion:MRI can accurately evaluate pelvic floor function of SUI patients. However, TVT did not significantly improve weak pelvic supporting structures and pelvic organ prolapse.

Objective:In order to put forward relevant measures and suggestions to improve the quality of the Investigator-Initiated Trials of oncology in medical institutions.Methods:Through literature research, comparative study, combined with the implementation and management of investigator initiated trials, the current status and challenges of the administration of these trials were analyzed.Results:Investigator-Initiated Trials of oncology become increasingly important. However, its quality is poor compared with Industry-Sponsored Trials due to insufficient funds and lack of effective supervision. Besides, four main challenges as follows were identified: lack of clinical research professionals, the quality concerns of ethical review in some institutions, insufficient funding for clinical research, and imperfect quality management system.Conclusions:Based on the actual needs of IITs of oncology, medical institutions should strengthen the talent cultivation, establish electronic information management platform, increase project support, strengthen scientific research supervision and deepen the awareness of risk prevention to improve the quality of investigator initiated trials.

Objective:The two detection method for the detection of hepatitis A virus (HAV) in strawberries were optimized and compared to select the best detection method for the detection of hepatitis A virus in strawberries.Methods:Different concentrations of HAV were inoculated on the surface of known negative frozen strawberry specimens, the concentration of beef extract powder in alkaline elution-PEG concentration method was optimized, the optimal nucleic acid extraction kit was selected, the optimal lysis buffer volume in direct lysis method was optimized, and the recovered viral load was detected by Real-time fluorescence quantitative RT-PCR. SPSS26.0 was used to statistically analyze the data, and the optimized two method were used for the detection of actual specimens.Results:The concentration of beef extract powder by the optimized alkaline elution-PEG concentration method was selected at 3%, and the viral nucleic acid extraction kit was selected as kit B. Six ml of lysis buffer was selected for the optimized direct lysis method. The recovery rates of HAV virus by alkaline elution-PEG concentration and direct lysis were compared with the HAV addition levels, and the HAV virus recovery rates of the two method were 21.50±1.06% and 5.82±0.01%, respectively, and the result showed that the differences were statistically significant. A total of 60 strawberry specimens from four regions were tested at the same time, and the result were all negative.Conclusions:The optimized alkaline elution-PEG concentration method has higher sensitivity and is more suitable for the detection of HAV in strawberry specimens.

Objective:To establish a digital droplet RT-PCR(dRT-PCR) method for Hepatitis A virus (HAV), and compare it with Real time RT-PCR(RT-qPCR) method, and select the best method for detecting hepatitis A virus in strawberry.Methods:Extract HAV vaccine RNA, optimize the reaction conditions of dRT-PCR and evaluate its specificity; Alkaline elution -PEG concentration method was used to extract nucleic acid from strawberry samples. At the same time, dRT-PCR and RT-qPCR method were used to detect the sensitivity and inhibition rate of HAV vaccine RNA in pure water and strawberry matrix, and the recovery rate of HAV in artificially contaminated strawberry was compared, which was applied to the detection of commercially available samples.Results:The optimal annealing temperature for dRT-PCR reaction was 60 ℃, and the optimal concentrations of primers and probes were 0.4 μmol/L、0.4 μmol/L and 0.2 μmol/L, with good specificity. There is no significant difference in sensitivity between the two method in detecting HAV vaccine RNA in pure water and strawberry matrix. The inhibition rate of dRT-PCR is low. The recovery rates of dRT-PCR and RT-qRCR in the detection of strawberry samples contaminated with HAV at higher concentrations were 12.90±0.006% and 30.12±0.02%, respectively. The recovery rates of lower concentrations of HAV contaminated strawberry samples were 18.27±0.07% and 10.85±0.03%, respectively, and the difference was statistically significant ( P<0.05). When strawberry samples on the market were tested, the result of both method were negative. Conclusions:The sensitivity of dRT-PCR method established in this study is not significantly different from that of RT-qPCR in detecting HAV RNA in different substrates, but dRT-PCR has good tolerance to PCR reaction inhibitors and high recovery rate when detecting low concentration HAV. Both detection method can be used for quantitative detection of hepatitis A virus in strawberry, and can be selected according to the actual situation.