Objective To explore the mechanism of immunoregulation by investigating the effects of polysaccharides from Millettia speciosa Champ (MSC) on proliferation of spleen lymphocyte and secretion of cytokine in mice.Methods The effects of MSC polysaccharides on Con A-induced spleen T lymphocyte proliferation were determined by MTT.The contents of TNF-α, IL-6 and PGE2 were determined by ELISA.Results The Con A-induced T lymphocyte proliferation was significantly increased by MSC polysaccharides at the concentrations from 50 to 200 μg·mL-1.Coupled with TNF-α and IL-6 were significantly increased while PGE2 was significantly decreased.Conclusion MSC polysaccharides could increase proliferation of spleen lymphocyte and enhance the immune responses by increasing the secretion of TNF-α and IL-6 in mice.

Objective:To investigate the epidemiology of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in patients with maintenance hemodialysis (MHD) in Jiangsu province during SARS-CoV-2 pandemic in China from December 7, 2022 to January 27, 2023, and to analyze the influencing factors of all-cause death.Methods:It was a multi-center cross-sectional investigation. Structured questionnaire was used to collect patient information by medical staff of each hemodialysis center (room) as investigators. Part of the demography data and laboratory examination data came from the Jiangsu Province Hemodialysis Data Information System. MHD patients from hemodialysis centers (rooms) at all levels of medical institutions and independent hemodialysis institutions in Jiangsu province during the outbreak of SARS-CoV-2 infection were included, and the clinical characteristics and all-cause mortality of confirmed and suspected cases of SARS-CoV-2 infection were analyzed.Results:Questionnaire surveys and data analysis on 57 278 patients in 407 hemodialysis centers (rooms) were completed, accounting for 90.41% of the total number of MHD patients (63 357 cases) in Jiangsu province during the same period. There were 24 038 cases (41.97%) of SARS-CoV-2 infection and 14 805 cases (25.85%) of suspected infection, which were widely distributed in all dialysis centers in Jiangsu province. After clinical classification of 38 843 confirmed and suspected SARS-CoV-2 infection cases, 3 662 cases were severe and critical cases, accounting for 9.43% of the infected and suspected cases. Among the patients who had completed the questionnaires, there were 1 812 all-cause deaths, with an all-cause mortality rate of 3.16%. Multivariate logistic regression analysis showed that elderly (taking ≤50 years as a reference, 51-59 years: OR=1.583, 95% CI 1.279-1.933, P=0.001; 60-69 years: OR=3.972, 95% CI 3.271-4.858, P<0.001; 70-79 years: OR=7.236, 95% CI 5.917-8.698, P<0.001; ≥80 years: OR=11.738, 95% CI 9.459-14.663, P<0.001), male ( OR=1.371, 95% CI 1.229-1.529, P<0.001), and co-infection with hepatitis B virus (HBV) (positive serum HBV surface antigen, OR=0.629, 95% CI 0.484-0.817, P<0.001) were independent influencing factors for all cause mortality. Receiver-operating characteristic curve analysis showed that the area under the curve for male, age and current HBV infection prediction of all-cause death was 0.529 ( P<0.001), 0.724 ( P<0.001) and 0.514 ( P=0.042), respectively, and the cut-off value for age prediction of all-cause death was 65.5 years old. Compared with patients without HBV infection, MHD patients with HBV infection significantly reduced the proportion of severe and critically ill patients, all-cause hospitalizations and all cause deaths when infected with SARS-CoV-2 (4.99% vs. 6.41%, χ2=6.136, P=0.013; 8.90% vs. 11.44%, χ2=11.662, P<0.001; 2.01% vs. 3.37%, χ2=10.713, P=0.001, respectively). Conclusion:The MHD patients in Jiangsu province are susceptible to SARS-CoV-2. Elderly age and male gender are independent risk factors for death in MHD patients during the epidemic, while the HBV infection may be a protective factor for death of MHD patients infected with SARS-CoV-2.