Drug-induced nephrotoxicity is very common in both new drug development and clinic practice. Various drugs can induce kidney injuries, including tubulointerstitial, glomerular and renal vascular disease. To investigate the mechanism of drug induced nephrotoxicity is important for risk reduction of new drug development, reasonable drug usage, early discovery and effective prevention/treatment of adverse effects in clinics.

Objective To investigate changes of regulatory T (Treg) cell proportion and activity in patients with decompensated hepatitis B-related cirrhosis complicated with bacterial infections.Methods Thirty patients with decompensated hepatitis B-related cirrhosis complicated with bacterial infections,20patients with decompensated hepatitis B-related cirrhosis without bacterial infection and 10 healthy controls were recruited in the study from Renmin Hospital of Wuhan University during January 2009 and December 2011.Peripheral blood mononuclear cells (PBMCs) were obtained from blood samples via density gradient centrifugation.The proportion of CD4+ CD25+ CD127low Treg cells in CD4+ cells was detected by flow cytometry.The immune activity of Treg cells isolated from PBMCs was observed by a suppression assay of allogeneic mixed lymphocyte response (MLR).Results Patients with decompensated hepatitis B-related cirrhosis complicated with bacterial infections had significantly lower percentage of Treg cells in CD4 + T cells of PBMCs than the patients with decompensated hepatitis B-related cirrhosis without bacterial infections [(4.07±1.18)％ vs.(9.74 ±3.00)％,t =9.35,P＜0.01].The suppression ability to homologous PBMCs proliferation of Treg cells isolated from patients with decompensated hepatitis B-related cirrhosis complicated with bacterial infections was significantly weakened as demonstrated in MLR assay [ cpm =(22.79 ± 4.94) × 103],which had a statistical difference compared with both the patients with decompensated hepatitis B-related cirrhosis without bacterial infection and the healthy controls [ cpm =(6.43±1.19) × 103 and (5.96 ± 1.25) × 103 respectively; t =16.09 and 16.51,P＜ 0.01].Conclusion There is a decrease of both quantity and activity of Treg cell in the patients with decompensated hepatitis B-related cirrhosis complicated with bacterial infections.

Antibody-drug conjugates(ADCs)are commonly heterogeneous and require extensive assessment of exposure-efficacy and exposure-safety relationships in preclinical and clinical studies.In this study,we report the generation of a monoclonal antibody against monomethyl auristatin E(MMAE)and the development,validation,and application of sensitive and high-throughput enzyme-linked immunosor-bent assays(ELISA)to measure the concentrations of MMAE-conjugated ADCs and total antibodies(tAb,antibodies in ADC plus unconjugated antibodies)in cynomolgus monkey sera.These assays were suc-cessfully applied to in vitro plasma stability and pharmacokinetic(PK)studies of SMADC001,an MMAE-conjugated ADC against trophoblast cell surface antigen 2(TROP-2).The plasma stability of SMADC001 was better than that of similar ADCs coupled with PEG4-Val-Cit,Lys(m-dPEG24)-Cit,and Val-Cit linkers.The developed ELISA methods for the calibration standards of ADC and tAb revealed a correlation be-tween serum concentrations and the OD450 values,with R2 at 1.000,and the dynamic range was 0.3-35.0 ng/mL and 0.2-22.0 ng/mL,respectively;the intra-and inter-assay accuracy bias％ranged from-12.2％to-5.2％,precision ranged from-12.4％to-1.4％,and the relative standard deviation(RSD)was less than 6.6％and 8.7％,respectively.The total error was less than 20.4％.The development and validation steps of these two assays met the acceptance criteria for all addressed validation parameters,which suggested that these can be applied to quantify MMAE-conjugated ADCs,as well as in PK studies.Furthermore,these assays can be easily adopted for development of other similar immunoassays.

Objective To analyze the risk factors of bleeding in elderly patients with peptic ulcer disease (PUD) and its correlation with Helicobacter pylori (Hp) infection, and to provide a theoretical basis for clinical diagnosis and treatment of elderly patients with PUD bleeding. Methods A total of 418 elderly PUD patients admitted to our hospital from June 2019 to June 2020 were selected. The ¹³C-urea breath test was used to determine HP infection. PUD patients were divided into observation group (n=87, bleeding) and control group (n=331, no bleeding). Age, sex, ulcer number, ulcer location, ulcer stage, ulcer diameter and other clinical data were collected. Univariate analysis and logistic regression were used to analyze the risk factors of bleeding in elderly PUD patients. The Forrest classification was used to evaluate the severity of PUD bleeding patients. Pearson correlation analysis was performed between Forrest classification and Hp infection in elderly PUD bleeding patients. Results There were statistically significant differences between the two groups in the course of disease, PUD history, NSAIDs application/ulcer number, ulcer diameter, ulcer location, ulcer stage, Hp infection and NSAIDs application (P<0.05). Multivariate logistic regression analysis showed that the use of NSAIDs, active ulcer, Hp infection and ulcer diameter ≥2 cm were risk factors for bleeding in elderly patients with PUD (P<0.05). The Hp positive rate in Forrest I patients was significantly higher than that in Forrest II and Forrest III patients (P<0.05). The positive rate of Hp in Forrest II patients was significantly higher than that in Forrest III patients. Pearson correlation analysis showed that Hp infection was positively correlated with the severity of peptic ulcer bleeding in the elderly (r=0.512, P<0.05). Conclusion The risk of bleeding from PUD is higher in the elderly, especially in patients with active ulcer, Hp infection and ulcer diameter ≥ 2 cm. In the treatment process of PUD patients, the eradication therapy of Hp should be emphasized, which can reduce the risk of bleeding.

Glycosite-specific antibody‒drug conjugatess (gsADCs), harnessing Asn297 N-glycan of IgG Fc as the conjugation site for drug payloads, usually require multi-step glycoengineering with two or more enzymes, which limits the substrate diversification and complicates the preparation process. Herein, we report a series of novel disaccharide-based substrates, which reprogram the IgG glycoengineering to one-step synthesis of gsADCs, catalyzed by an endo-N-acetylglucosaminidase (ENGase) of Endo-S2. IgG glycoengineering via ENGases usually has two steps: deglycosylation by wild-type (WT) ENGases and transglycosylation by mutated ENGases. But in the current method, we have found that disaccharide LacNAc oxazoline can be efficiently assembled onto IgG by WT Endo-S2 without hydrolysis of the product, which enables the one-step glycoengineering directly from native antibodies. Further studies on substrate specificity revealed that this approach has excellent tolerance on various modification of 6-Gal motif of LacNAc. Within 1 h, one-step synthesis of gsADC was achieved using the LacNAc-toxin substrates including structures free of bioorthogonal groups. These gsADCs demonstrated good homogeneity, buffer stability, in vitro and in vivo anti-tumor activity. This work presents a novel strategy using LacNAc-based substrates to reprogram the multi-step IgG glycoengineering to a one-step manner for highly efficient synthesis of gsADCs.