Objective: To investigate the effects of platelet-derived PD-L1 released during storage on T cell proliferation, apoptosis, and cytokine expression. Methods: Apheresis platelets were stored with agitation at 22℃. Platelet supernatant was collected on days 1, 3, 5, and 7 of storage, and then co-cultured with human CD4 and CD8 mixed T cells isolated by magnetic bead sorting. CCK8 assay was used to detect T cell proliferation; flow cytometry was applied to determine T cell apoptosis as well as the expression levels of IFN-γ and GZMB. Additionally, Western blot was employed to examine alterations in downstream signaling molecules of the PD-1 receptor. Results: With the prolongation of platelet storage time, the inhibitory effect of platelet storage medium on T cell proliferation was gradually enhanced, accompanied by suppressed expression of IFN-γ and GZMB, whereas the apoptosis level of T cells increased progressively. Treatment with PD-1 antibody or PD-L1 antibody partially blocked the regulatory effects of platelet storage medium on T cell proliferation, apoptosis, and the expression of IFN-γ and GZMB. Western blot results showed that the phosphorylation levels of p-SHP1 and p-SHP2 were significantly upregulated, whereas p-AKT expression was downregulated in T cells co-cultured with platelet storage medium. Intervention with PD-1 or PD-L1 antibody could partially reverse the above changes in protein expression. Conclusion: During platelet storage, platelet-derived PD-L1 in the storage medium promotes T cell apoptosis and inhibits T cell proliferation as well as the expression of related cytokines in a time-dependent manner. Therefore, platelet-derived PD-L1, as an important immune regulatory mediator, may be involved in transfusion-related immunomodulation (TRIM).

Objective: To evaluate the application of blood conservation measures in obstetric patients with different red blood cell transfusion volumes and to assess the impact of different transfusion volumes on postpartum outcomes. Methods: A retrospective investigation was conducted on 448 obstetric patients who received blood transfusions at the Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine from January 2016 to December 2022. Patients were divided into four groups (1-2 units group, 3-4 units group, 5-6 units group, and >6 units group) based on the volumes of red blood cells (RBCs) transfused during and within 7 days after delivery. The maternal physiological indicators, pre- and postpartum laboratory test indicators, obstetric complications, application of blood conservation measures, use of blood products, and postpartum outcomes were reviewed. The clinical characteristics, application of blood conservation measures, and their impact on postpartum outcomes were compared among different transfusion groups. Results: There were statistically significant differences in the multivariate logistic analysis of history of previous cesarean section (OR=1.781), eclampsia/pre-eclampsia/(OR=1.972) and postpartum blood loss>1 000 mL（OR=1.699）(P<0.05) among different transfusion groups. In terms of blood conservation measures, the more RBCs transfused, the higher the rate of mothers receiving blood conservation measures such as balloon occlusion, arterial ligation, autologous blood transfusion with a cell saver, and hysterectomy. With the increase in the volume of RBCs transfusion, the demand for fresh frozen plasma（FFP）, cryoprecipitate, and platelet transfusions also increased. The hospitalization days for the four groups of parturients were 6.0 (4.0-9.0), 7.5 (5.0-14.8), 7.0 (4.5-13.0) and 11.0 (9.0-20.5), respectively (P<0.05) and the rates of ICU transfer were 2.0% (5/250), 9.4% (12/128),18.2% (6/33) and 51.4% (19/37), respectively (P<0.05). Both increased significantly with the increase in the volume of RBCs transfusion, and the differences between groups were statistically significant. Conclusion: Parturients who received higher volume of RBCs had multiple risks factors for bleeding before childbirth, had higher postpartum blood loss, and had a higher rate of application of various blood conservation measures. In addition, an increase in the volume of RBCs transfusion may have adverse effects on postpartum recovery.

Nonalcoholic fatty liver disease (NAFLD) is characterized by hepatic steatosis caused by nonalcoholic factors, and its pathogenesis, progression, treatment, and prevention have attracted more and more attention. At present, an increasing number of studies have been conducted on the association of intestinal microecology with various metabolic diseases such as obesity, diabetes, and cardiovascular diseases. Recent studies have found that butyrate, a metabolite of intestinal flora, is closely associated with NAFLD and can affect the development and progression of NAFLD through various mechanisms, such as alleviating inflammatory response, inhibiting insulin resistance, and reducing oxidative stress of liver mitochondria. Exploration of the association between butyrate and NAFLD is expected to provide a new approach for the prevention and treatment of NAFLD.

Objective To investigate the predictive value of metastatic lymph node ratio (MLNR) combined with preoperative serum carcinoembryonic antigen (CEA) in the detection of distant metastasis of stage Ⅱ-Ⅲ colon cancer after radical resection.Methods A retrospective study was performed on the clinical data of 325 patients with stage Ⅱ-Ⅲ colon cancer undergoing radical resection in the Second Hospital of Lanzhou University from Jan 2010 to Jan 2015.Results MLNR was correlated with the maximum diameter of tumors,the degree of differentiation of tumors,clinical TNM stage and distant metastasis (P ＜ 0.05),serum CEA was correlated with the maximum diameter of tumors,clinical TNM stage,nerve or vascular invasion and distant metastasis (P ＜ 0.05).Logistic regression analysis showed that low differentiation of tumor tissue,TNM Ⅲ stage,high MLNR and high serum CEA were independent risk factors for distant metastasis of colon cancer after radical operation.Conclusions The combined detection of MLNR and serum CEA has a good predictive value for distant metastasis with stage Ⅱ-Ⅲ colon cancer.