Cases of 2019-nCoV nucleic acid and antibody (IgM and IgG total antibody) after discharge from a hospital in Chongqing were continuously monitored. It was found that 5 cases of "re-positive" phenomenon, 5 cases of antibody were positive, and there was a trend of increasing with time. "Re-Positive" may be related to the following three factors. Children with asymptomatic infection had a long time of fecal detoxification.There were two consecutive nucleic acid tests "false negative" caused by various reasons.The virus clearance in patients was not complete, and the discharge standard was not conservative enough. The analysis of the causes of "Re-Positive" patients and the discussion of its infection will help us reveal more characteristics of this virus, and to provide a new basis for the discharge standard in the constantly updated diagnosis and treatment programme.

Background::Histological healing is closely associated with improved long-term clinical outcomes and lowered relapses in patients with ulcerative colitis (UC). Here, we developed a novel diagnostic criterion for assessing histological healing in UC patients.Methods::We conducted a retrospective cohort study in UC patients, whose treatment was iteratively optimized to achieve mucosal healing at Shanghai Tenth People’s Hospital of Tongji University from January 2017 to May 2022. We identified an inflammatory cell enumeration index (ICEI) for assessing histological healing based on the proportions of eosinophils, CD177 + neutrophils, and CD40L + T cells in the colonic lamina propria under high power field (HPF), and the outcomes (risks of symptomatic relapses) of achieving histological remission vs. persistent histological inflammation using Kaplan-Meier curves. Intrareader reliability and inter-reader reliability were evaluated by each reader. The relationships to the changes in the Nancy index and the Geboes score were also assessed for responsiveness. The ICEI was further validated in a new cohort of UC patients from other nine university hospitals. Results::We developed an ICEI for clinical diagnosis of histological healing, i.e., Y = 1.701X 1 + 0.758X 2 + 1.347X 3 - 7.745 (X 1, X 2, and X 3 represent the proportions of CD177 + neutrophils, eosinophils, and CD40L + T cells, respectively, in the colonic lamina propria under HPF). The receiver operating characteristics curve (ROC) analysis revealed that Y <-0.391 was the cutoff value for the diagnosis of histological healing and that an area under the curve (AUC) was 0.942 (95% confidence interval [CI]: 0.905-0.979) with a sensitivity of 92.5% and a specificity of 83.6% ( P <0.001). The intraclass correlation coefficient (ICC) for the intrareader reliability was 0.855 (95% CI: 0.781-0.909), and ICEI had good inter-reader reliability of 0.832 (95% CI: 0.748-0.894). During an 18-month follow-up, patients with histological healing had a substantially better outcome compared with those with unachieved histological healing ( P <0.001) using ICEI. During a 12-month follow-up from other nine hospitals, patients with histological healing also had a lower risk of relapse than patients with unachieved histological healing. Conclusions::ICEI can be used to predict histological healing and identify patients with a risk of relapse 12 months and 18 months after clinical therapy. Therefore, ICEI provides a promising, simplified approach to monitor histological healing and to predict the prognosis of UC.Registration::Chinese Clinical Trial Registry, No. ChiCTR2300077792.

Objective: To investigate the effects of autologous platelet-rich plasma (aPRP) collected using a continuous blood cell separator on blood conservation and prognosis in patients with type A aortic dissection. Methods: The clinical data of patients who underwent emergency aortic replacement for acute type A aortic dissection at our hospital from January 2020 to December 2023 were respectively analyzed. Patients were divided into two groups based on whether they received aPRP collection before surgery for subsequent reinfusion: the aPRP group (n=32) and the control group (n=35). The volume of aPRP collected and the platelet concentration in the aPRP were recorded. The volumes of allogeneic blood and blood products transfused, and the associated costs during hospitalization were compared between two groups. Intraoperative blood loss, perioperative laboratory parameter changes, 24-hour postoperative drainage volume, duration of ICU stay and mechanical ventilation, length of hospital stay, and mortality rate of the two groups were also compared. Results: The platelet concentration in aPRP was (491.5±85.4)×10 /L, accounting for (24.1±9.6)% of the patient's total platelet count. The volume of aPRP collected accounted for (23.0±6.3)% of the patient's total plasma volume. Compared with the control group, the aPRP group demonstrated significantly reduced transfusion volumes of allogeneic red blood cells, plasma, and platelets (P<0.05), along with significantly lower blood-related costs during hospitalization (P<0.05). Postoperative coagulation parameters (APTT, PT, INR, and TEG) were significantly improved (P<0.05), and platelet counts were markedly increased (P<0.05) in aPRP group as compared with the control group. No statistically significant differences were observed in postoperative use of prothrombin complex concentrate and fibrinogen between the two groups. Similarly, there were no significant differences in postoperative 24-hour drainage volume, 24-hour extubation rate, ICU length of stay, duration of mechanical ventilation, or total hospital length of stay. The incidence of complications and mortality did not differ significantly between the two groups. Conclusion: The administration of aPRP significantly reduces the requirement for perioperative allogeneic blood transfusion in patients undergoing surgery for type A aortic dissection. Furthermore, it enhances coagulation function and reduces associated transfusion costs, thereby establishing itself as an effective and safe strategy for blood conservation.