Objective:To explore the relationship between low serum albumin levels and its duration on first episode of peritonitis in peritoneal dialysis (PD) patients.Methods:PD patients who were regularly followed up in the Pearl River Delta region from September 1, 2000 to July 6, 2021 in Shunde Hospital of Southern Medical University, Nanfang Hospital of Southern Medical University, and Foshan First People′s Hospital were retrospectively selected. The patients were divided into low serum albumin group (LSA group, mean albumin<35 g/L), moderate serum albumin group (MSA group, 35 g/L≤mean albumin<40 g/L) and high serum albumin group (HSA group, mean albumin≥40 g/L) according to the mean albumin of the patients, and the differences among the three groups were compared. The Kaplan-Meier survival analysis method was used to compare the risk of peritonitis events in different mean albumin groups and different durations of hypoalbuminemia. The multivariate Cox regression model was used to analyze the relationship between serum albumin levels and duration of hypoalbuminemia and new-onset peritonitis.Results:A total of 1 853 PD patients were included in this study, aged (49.72±15.34) years, and 1 036(55.9%) males. There were 551 patients (29.7%) in the LSA group, 920 patients (49.7%) in the MSA group, and 382 patients (20.6%) in the HSA group. The median follow-up was 37 (15, 66) months and there were 508 patients (27.4%) with new-onset peritonitis during the follow-up. Compared with the LSA group, the incidence of new peritonitis in the MSA group and HSA group was lower ( χ2=14.053, P<0.001; χ2=21.857, P<0.001), but there was no significant difference in the incidence of new peritonitis between the HSA group and MSA group. The Kaplan-Meier survival analysis showed that the cumulative incidence of peritonitis in the LSA group was significantly higher than that in the MSA group and HSA group (Log-rank χ2=22.128, P<0.001). Compared with PD patients with normal serum albumin, the patients with longer duration of hypoalbuminemia tended to have a higher incidence of new peritonitis. Multivariate Cox regression analysis showed that the mean albumin<35 g/L (LSA group/MSA group, HR=1.495, 95% CI 1.198-1.866, P<0.001; LSA group/HSA group, HR=1.459, 95% CI 1.104-1.928, P=0.008) was an independent risk factor of new-onset peritonitis in PD patients and the prolongation of duration of hypoalbuminemia had a significantly higher risk of new-onset peritonitis ( HR=1.013, 95% CI 1.003-1.024, P=0.014). Conclusion:The mean albumin<35 g/L and prolong duration of hypoalbuminemia are independent risk factors of PD-related peritonitis in PD patients.

Objective To investigate the relationship between serum uric acid level and renal function decline by retrospective cohort study.Methods Through the physical examination system of the First People's Hospital of Foshan,the physical examination data from 2015 to 2018 of a public institution in Foshan city were obtained.The gender,age,blood cell analysis,liver function,serum creatinine,uric acid,fasting blood glucose were obtained.The change of eGFR (△eGFR=eGFR2018-eGFR2015) was analyzed.Results A total of 2505 subjects were followed up for four years.The subjects were divided into △eGFR ≥0 group and △eGFR ＜ 0 group.There were 845 subjects in △eGFR ≥0 group,and 1660 subjects in △eGFR ＜ 0 group.Compared with that in △eGFR ＜ 0 group,the base-level of uric acid in △eGFR ≥ 0 group was higher [(349.48±87.62) μmol/L vs (325.72±82.58) μmol/L,t=6.669,P ＜ 0.001],but the rate of uric acid decline was greater [-15.00(-53.50,17.00) μmol/L vs 15.50(-18.00,49.00) μmol/L,Z=-13.470,P ＜ 0.001].According to the levels of uric acid in 2015 and 2018,then the subjects were divided into four groups,normal to normal group (N-N,1551 cases),normal change into high uric acid group (N-H,299 cases),high uric acid drop to normal group (H-N,238 cases),and high to high uric acid group (H-H,417 cases).The △eGFR was-1.58(-4.17,1.01) ml · min-1 · (1.73 m2) 1 in N-N group,and-3.60(-7.24,-0.98) ml · min-1 · (1.73 m2)-1 in N-H group,-0.20(-3.14,3.27) ml· min-1· (1.73 m2)-1 in H-N group,-0.96(-4.07,1.93) ml· min-1· (1.73 m2)-1 in H-H group,respectively.The △eGFR decreased most significantly in N-H group than the other three groups (x2=103.130,P ＜ 0.001).Multivariate logistic regression analysis showed that elevated uric acid was an independent risk factor for eGFR decline (OR=1.739,95％CI 1.587-1.906,P ＜ 0.001),while elevated indirect bilirubin (OR=0.968,95％CI 0.943-0.993,P=0.013),elevated red blood cells (OR=0.815,95％ CI 0.680-0.976,P=0.026) were independent protective factors for eGFR decline.Conclusion Elevated uric acid is an independent risk factor for the decline of renal function.Good control of hyperuricemia is beneficial to the protection of renal function.

Objective To establish and evaluate a method for rapid and sensitive S.xylosus detection using qPCR(real-time quantitative PCR).Methods A gehM gene fragment was selected as the target for S.xylosus.A set of specific primers was synthesized and a qPCR method was established to detect S.xylosus.A S.xylosus standard strain and other non-target strains were chosen for analysis.DNA of S.xylosus was diluted 10-fold to determine its sensitivity.Clinical samples were tested,and positive products were sequenced.The result were compared with those of bacterial culture.Results S.xylosus had a specific amplification curve,whereas other non-S.xylosus species did not,indicating that the primers were specific for S.xylosus.Sensitivity was 100 fg/μL DNA.Repeatability within and between groups was less than 3％.A total of 60 clinical samples were analyzed,of which five samples had a typical S curve.qPCR products were sequenced and BLAST searched.The similarity of the gene sequences was 99.63％,indicating that the sample was positive for the S.xylosus gehM gene with a positivity rate of 8.3％.However,the positivity rate of bacterial culture was 6.7％.The positivity rate of qPCR was slightly higher than that of the culture.Conclusions The established qPCR method is rapid with high sensitivity and specificity,and can be used to detect S.xylosus.

The microbiological quality of laboratory animals is crucial for the validity and reproducibility of scientific research data, as well as human health and animal welfare. Currently, individual ventilation cages (IVC) have become the mainstream feeding system for rodent laboratory animals. The most commonly used pathogen monitoring method for this feeding system is soiled bedding sentinels (SBS). This method monitors the microbial carrying status of mouse colony through indirect contact and delayed feedback. It can effectively monitor pathogens transmitted via the fecal-oral route, such as mouse hepatitis virus and reovirus. However, this method has difficulty detecting pathogens mainly transmitted through aerosols or direct contact, such as Sendai virus and Pasteurella pneumotropica. The exhaust air dust (EAD)-PCR monitoring method involves swab sampling in the IVC exhaust ducts to monitor the corresponding racks of the ducts; swab sampling before the prefiltration of the host to monitor the entire IVC rack; and EAD collection device sampling to monitor all racks connected to the same host. Different IVC manufacturers have developed corresponding EAD collection devices for their respective IVC systems, making operations convenient and standardization easy. Compared with the SBS method, the EAD-PCR method significantly improves detection rate and timeliness, with the fastest detection possible after one week of exposure. It can serve as a supplement or replacement for the SBS method. Currently, increasing evidence supports that EAD-PCR testing is a more reliable, sensitive, and cost-effective monitoring method, and is more beneficial to animal welfare. This article reviews the application progress of these two methods for monitoring pathogens, analyzes the existing limitations of the EAD-PCR method, and proposes solutions based on its implementation in our laboratory and examination units. The EAD-PCR method helps reduce the number of live sentinel animals used in pathogen monitoring, in order to better maintain the "3Rs" principle of laboratory animal welfare.