AIM: To investigate the expression kinetics of PD-L1 and PD-L2 on the surface of the resting and activated B/T cells as well as monocytes from healthy human peripheral blood.METHODS: Fluorescent antibody staining together with flow cytometry were used to detect the percentages of the resting as well as the activated B cells and T cells that expressed PD-L1 and PD-L2.Meanwhile the percentages of the resting and activated monocytes that expressed PD-L2 were determined.RESULTS: Both resting B cells and T cells did not express PD-L1 on their surface,however PD-L1 expression was significantly up-regulated on the surface of the activated B cells after 6 h stimulation with LPS or pokeweed mitogen(PWM),and the percentages of B cells that expressed PD-L1 reached a plateau at 24 h,which were(46.26?10.71)% with LPS and(43.67?6.14)% with PWM stimulation,respectively.No markedly change of PD-L1 expression on the surface of the activated T cells after stimulation with LPS was observed,but upregulation of PD-L1 expression was observed when stimulation with PWM.The percentages of T cells that expressed PD-L1 reached a plateau at 24 h,which was(25.42?9.23)%.PD-L2 expression was not found on the resting as well as the activated B cells and T cells.In addition,the resting monocytes did not express PD-L2.Combination of INF-? plus LPS markedly induced the PD-L2 expression,and the percentages of monocytes that expressed PD-L2 reached a peak at 48 h,which was(28.70?14.22)%.CONCLUSION: The activated lymphocytes only express PD-L1,reaching a plateau at 24 h.PD-L2 is expressed on the surface of the activated monocytes,reaching a peak at 48 h.

To investigate the relationship between sex hormone binding globulin (SHBG) and metabolic syndrome in elderly males in Shanghai,all the subjects (≥ 60 years old,male) underwent measurements of weight,height,waist and hip circumferences,and blood pressures,serum levels of fasting plasma glucose,total cholesterol,triglyceride,high density lipoprotein-cholesterol (HDL-C),and low density lipoprotein-cholesterol were determined (Hitachi,7600),while the levels of serum insulin,total testosterone,and SHBG were determined by using chemiluminescence methods.Free testosterone was calculated by using the Vermeulen equation.Metabolic syndrome was defined according to the criteria of the Chinese Diabetes Society (CDS 2004).The SHBG level in the metabolic syndrome group was significantly lower than that in non-metabolic syndrome group [(40.50 ± 26.16) nmol/L vs (47.80± 20.34) nmol/L,P＜0.01].With increasing number of metabolic syndrome components,the level of SHBG became lowered progressively.The subjects were divided into four subgroups according to SHBG Quartiles.From Quartile 1 to Quartile 4,body mass index,waist-hip ratio,diastolic blood pressure,fasting plasma glucose,triglyceride,fasting insulin,homeostasis model assessment for insulin resistance(HOMA-IR),free testosterone,free androgen index,and free testosterone percentage became progressively lowered,while age and HDL-C became raised (P＜0.05).SHBG was correlated significantly with age,body mass index,waist-hip ratio,diastolic blood pressure,fasting plasma glucose,HDL-C,and triglyceride.Age,HDL-C,and body mass index remained independently associated with SHBG in the multivariate regression analysis.In a logistic regression taking metabolic syndrome as the dependent variable,SHBG and HOMA-IR were included in the final model with statistical significance.Lowered SHBG is a risk factor of metabolic syndrome in elderly males.SHBG may be an independent predictor of metabolic syndrome,but the mechanism of how SHBG is involved in the metabolic syndrome needs to be further studied.

Background: Studies have shown that transient receptor potential (TRP) channels play important roles in gastroesophageal reflux disease (GERD), however, the relationship between TRPV1 and TRPM8 in reflux esophagitis (RE) remains unclear. Aims: To investigate the expressions of TRPV1, TRPM8 and their correlation in guinea pigs with RE. Methods: Thirty male guinea pigs aged 3⁃4 weeks were randomly divided into 3 groups: blank control group, negative control group and model group, with 10 animals in each group. Guinea pigs in model group and negative control group were given esophageal perfusion with 0.1 mol/L HCl containing 0.5% pepsin and normal saline, respectively, once a day for 14 days; guinea pigs in blank control group were free to drink sterile water for 14 days. On day 15, the esophagus was dissected for macroscopic and histopathological examination, and Western blotting and/or real⁃time PCR were used to detect the expression levels of TRPV1, TRPM8, GNAQ (an isoform of G protein), and the tight junction proteins and proinflammatory cytokines in esophageal tissue. The co⁃localization of TRPV1 and TRPM8 was assessed by immunofluorescence. Results: Esophageal mucosal congestion, hyperplasia of esophageal epithelial cells, infiltration of inflammatory cells, as well as up⁃regulation of proinflammatory cytokines and down⁃regulation of tight junction proteins were observed in esophageal tissue of guinea pigs in model group, which indicated the successful RE model construction. As compared with the negative control group, expression levels of TRPV1 and GNAQ mRNA and protein were significantly increased, while expression levels of TRPM8 mRNA and protein were significantly reduced in esophageal tissue of guinea pigs in model group (all P<0.05). TRPV1 and TRPM8 channels were co ⁃ localized in the lamina propria of esophageal mucosa. Conclusions: There is a certain equilibrium mechanism between TRPV1 and TRPM8 channels in RE models. G protein⁃coupled receptor signaling pathway and the downstream TRPV1/TRPM8 might be involved in the occurrence and development of GERD.