Objective To investigate the prevalence and influencing factors of thyroid enlargement in school-age children in Tianjin. Methods School-age children were randomly selected in Tianjin to undergo thyroid ultrasound examination, and salt iodine, urine iodine, height, and weight tests. A questionnaire survey was conducted. Univariate and multivariate regression models were used to analyze the risk factors for thyroid enlargement. Results A total of 917 children aged 7-13 years in Tianjin were surveyed, with a thyroid enlargement rate of 4.03% and a median thyroid volume of 2.60 ml. There was a non-linear relationship between children's body mass index (BMI) and the incidence of thyroid enlargement in children (P=0.008), and a linear relationship between children's body surface area (BSA) and the incidence of thyroid enlargement in children (P<0.001). Being 9 years old (OR=3.728, 95%CI: 1.343-10.343, P=0.012), obesity (OR=3.886, 95%CI: 1.801-8.384, P=0.001), having lunch at school (OR=3.157, 95%CI: 1.497-6.658, P=0.003) and frequent consumption of preserved foods (OR=4.611, 95%CI: 1.643-12.945, P=0.004) were risk factors for goiter in children. Regular consumption of seaweed (OR=0.305, 95%CI: 0.100-0.927, P=0.036) was a protective factor for goiter in children. Conclusion The incidence of thyroid enlargement in children in Tianjin meets national standards. Obesity, eating lunch at school, frequently consuming pickled foods, and being 9 years old may be risk factors for thyroid enlargement in children. Eating seaweed or kelp regularly is a protective factor. At the same time, attention should be paid to the relationship between BMI, BSA, and thyroid enlargement rate in children..

Objective To explore the association between different levels of fluoride exposure and dyslipidemia in elderly people, and to analyze the influencing factors and their interactions. Methods A total of 1 143 elderly people over 60 years old were randomly selected from historical high water fluorosis areas and control areas in Tianjin. Logistic regression model and classification tree model were used to analyze the influencing factors of dyslipidemia, and to analyze the interaction between high fluoride exposure and relevant influencing factors on dyslipidemia. Results The prevalence of elevated low density lipoprotein cholesterol (LDL-C) was 5.69% (65/1 143). There was a significant difference in the prevalence of high LDL-C in different fluoride-exposed areas (2 = 0.092，P = 0.762). Multivariate logistic analysis showed that high fluoride exposure (OR=2.306，95%CI：1.185-4.491) and abdominal obesity (OR=2.274，95%CI：1.299-3.978) were risk factors for high LDL-C, while type B personality (OR=0.529，95%CI：0.308-0.908) was a protective factor for high LDL-C. The results of classification tree model showed that abdominal obesity contributed the most to the prevalence of high LDL-C in the elderly, followed by high fluoride exposure and hyperglycemia. There was a significant multiplicative interaction between high fluoride exposure and abdominal obesity on dyslipidemia (OR=5.191,95%CI：1.609-16.745，P=0.006). Conclusion High fluoride exposure may increase the risk of high LDL-C, and there is a multiplicative interaction between high fluoride exposure and abdominal obesity on dyslipidemia.

Objective To establish an acute rejection model of cervical heart transplantation in mice and evaluate the survival and dynamic rejection process post-transplantation. Methods Mice were randomly divided into sham operation group (n=10), syngeneic transplantation group (n=21), and allogeneic transplantation group (n=65). Sham operation, syngeneic cervical heart transplantation, and allogeneic cervical heart transplantation were performed respectively. The survival of recipient mice and grafts, histopathological changes of graft tissues, subpopulations of splenic lymphocytes, and expression of inflammatory factors in serum and grafts were observed. Results The survival rate and graft survival rate of the sham operation group and syngeneic transplantation group were 100% at 7 days after surgery. In the allogeneic transplantation group, 5 cases failed and died on the first day after surgery. The survival rate at 7 days after surgery was 86%, and all surviving mice had grafts that stopped beating at 7 days after surgery. The allogeneic transplantation group showed significant rejection at 7 days after surgery, accompanied by tissue damage and CD8⁺ T cell infiltration. The proportion of CD8⁺ T cells in the spleen continued to rise post-operation, while the proportion of CD4⁺ T cells showed a downward trend. The expression of interferon-γ in serum and grafts peaked at 5 days after surgery, while the expression of tumor necrosis factor-α showed no statistical significance. Conclusions Acute rejection following heart transplantation in mice intensifies between 5 to 7 days after surgery, which may be a critical time window for immunological intervention.

Liver transplantation is the most effective radical treatment for hepatocellular carcinoma (HCC), especially for patients with HCC complicated by cirrhosis. Since most patients are in an advanced stage of unresectable state when they are present, the preoperative downstaging treatment for liver transplantation in HCC is of great significance for increasing the opportunity for surgery, reducing the dropout rate from the liver transplant waiting list, and thereby lowering the postoperative recurrence rate. Currently, immune checkpoint inhibitor (ICI)-based combination immunotherapy and targeted therapy is the most effective treatment for preoperative downstaging in liver transplantation for HCC. However, the immunoenhancing effects of ICI may increase the risk of post-transplant rejection. Therefore, it is necessary to find a "critical point" that allows ICI to effectively inhibit tumor growth during preoperative downstaging treatment without causing severe rejection after transplantation. This article reviews the latest advances in preoperative ICI treatment protocols, efficacy assessment, indications, contraindications, drug discontinuation timing, and principles of prevention and treatment of rejection in liver transplantation for HCC.

Objective To evaluate the effect of irregular follow-up during normalized prevention and control of novel coronavirus pneumonia (COVID-19) epidemic on BK virus (BKV) reactivation and clinical prognosis of kidney transplant recipients. Methods Clinical data of 363 kidney transplant recipients were retrospectively analyzed, and they were divided into the pre-epidemic follow-up group and during-epidemic follow-up group according to the follow-up time. All patients were followed up for 1 year. The follow-up interval was compared between two groups. The infection of BKV and the correlation between the infection process of BKV and renal graft function were analyzed in two groups. Results A total of 1 790 preson-times were followed up before COVID-19 epidemic and 2 680 during COVID-19 epidemic. Compared with the during-epidemic follow-up group, the follow-up intervals within 3, 3-6 and 7-12 months after kidney transplantation were shorter in the pre-epidemic follow-up group, and the differences were statistically significant (all P<0.05). Within 1 year after kidney transplantation, 35 cases（32%） were diagnosed with BKV viruria, 3 cases（3%） of BKV viremia and 1 case（1%） of BKV-associated nephropathy (BKVAN) in the pre-epidemic follow-up group, and 53（25%）, 3（1%） and 1（1%） in the during-epidemic follow-up group, with no statistical significance (all P>0.05). In the pre-epidemic follow-up group, the time for the initial diagnosis of BKV viruria was longer and the viral load of the first urinary BKV reactivation was smaller than those in the during-epidemic follow-up group, with statistical significance (both P<0.05). The load of the first urinary BKV reactivation was positively correlated with the peak load of urinary BKV, and the differences between the baseline and serum creatinine levels at 1 and 3 months after BKV reactivation (all P<0.05). Conclusions Irregular follow-up after kidney transplantation may lead to early BKV reactivation and higher detection value of the first viral load of urinary BKV, delay diagnosis and interventions, and lead to poor prognosis. It is urgent to establish a remote follow-up system to meet the follow-up requirements of kidney transplant recipients when public health incidents occur.