Objective To develop an ELISA method for determination of heparin-induced thrombocytopenia (HIT)antibody. Methods The compound formed between human platelet factor 4 (PF4)and heparin was used as the coating antigen,incu-bating the patients plasma with the coating antigen in the well,after washing,the second antibody labeled HRP was added in the well to incubate and washing again,the chromogenic substrates was added in the well to incubate,when the stop reaction was finished,the absorbance A450/A630 was detected,and the test results were judged according to standard,this method was compared with IBL method and was optimized and evaluated the performance.Results An indirect ELISA method was de-velop with the purified human PF4,the optimal dilution of sample and second antibody were 1∶100 and 1∶1 500 which de-tected by the orthogonal test,the intra-and inter-assay average coefficients of variation were 7.66% and 7.76%(<10%) respectively that detected by repeated measurement the three positive standard plasma.Through measureing the 100 healthy human plasm with no history of using heparin,the positive and negative predictive reference values were 0.304 and 0.456. IBL and this method detected 100 hemodialysis patients samples at the same time,and the result of statistical analysis was that,the sensitivity,speciality and accuracy of this method were 90%,97.78% and 90%,respectively.The negative and posi-tive predictive value were 81.8% and 98.88% respectively,and the difference was statistically significant [K=0.84(0.81~1)and Pexac=0.012<0.05].The difference was statistically significant,consistency was optimal,95% confidence interval was 92.59%~92.59%.Conclusion Comparing with the IBL,the method reported by this article had the similar perform-ance and good consistency,and it could satisfy the clinical detection and diagnosis of HIT patients.

Objective To explore the effect of etoricoxib combined with Bitong decoction formula on the clinical efficacy and serum level of patients with knee osteoarthritis.Methods Retrospective analysis was used to collect patients with knee osteoarthritis admitted to our hospital from August 2022 to August 2023.According to the medication method,they were divided into the combined group and the control group.The control group was given etoricoxib tablets,and the combination group was given a combination of Bitong decoction formula on the basis of the control group.Both groups were treated for one month.The efficacy after treatment,Traditional Chinese Medicine(TCM)syndrome score,the knee joint function[osteoarthritis index(WOMAC),Lequesne score],inflammatory indicators[interleukin-1β(IL-1β),tumor necrosis factor-α(TNF-α),matrix metalloproteinase-3(MMP-3),tissue inhibitor of metalloproteinase-1(TIMP-1)],oxidative stress indicators[total antioxidant capacity(TAOC),lipid peroxidation(LPO),nitric oxide(NO)]before and after treatment and safety of the two groups were compared.Results A total of 162 patients were included,with 81 in each group.The overall efficacy and total effective rate of the combined group were higher than those of the control group(P＜0.05).After treatment,TCM syndrome score,WOMAC,Lequesne score,IL-1 β,TNF-α,MMP-3,TIMP-1,LPO and NO levels in two groups were decreased compared with before treatment,while TAOC increased compared with before treatment(P＜0.05),and all the above indexes in the combination group were better than those in the control group(P＜0.05).The safety of the two groups was comparable(P＞0.05).Conclusion The efficacy of etoricoxib combined with Bitong decoction formula in knee osteoarthritis is better than that of single western medicine,which can alleviate symptoms and improve knee joint function,as well as reduce inflammation and oxidative stress,and has high safety.

Objective:By analyzed the transmission patterns of 4 out of the 51 COVID-19 cluster cases in Shaanxi province to provide evidences for the COVID-19 control and prevention.Methods:The epidemiological data of RT-PCR test-confirmed COVID-19 cases were collected. Transmission chain was drawn and the transmission process was analyzed.Results:Cluster case 1 contained 13 cases and was caused by a family of 5 who traveled by car to Wuhan and returned to Shaanxi. Cluster case 2 had 5cases and caused by initial patient who participated family get-together right after back from Wuhan while under incubation period. Cluster case 3 contained 10 cases and could be defined as nosocomial infection. Cluster case 4 contained 4 cases and occurred in work place.Conclusion:Higher contact frequency and smaller places were more likely to cause a small-scale COVID-19 cluster outbreak, with potential longer incubation period. COVID-19 control strategies should turn the attention to infection prevention and control in crowded places, management of enterprise resumption and prevention of nosocomial infection.

Objective:To understand the incidence trend and epidemiological characteristics of COVID-19 in Shaanxi province.Methods:The incidence data of COVID-19 reported in Shaanxi as of 22 February, 2020 were collected for an epidemiological descriptive analysis.Results:A total of 245 confirmed cases of COVID-19 were reported in Shaanxi. Most cases were mild (87.76%). As time passed, the areas where confirmed cases were reported continued to increase. The case number in Xi’an was highest, accounting for nearly half of the total reported cases in the province. The epidemic pattern in Shaanxi had gradually shifted from imported case pattern to local case pattern, and the transmission of local cases was mainly based on family cluster transmission. The confirmed cases from different sources had caused the secondary transmission in Shaanxi. After February 7, the number of reported cases began to fluctuate and decrease stably, indicating a decrease-to-zero period.Conclusions:At present, the overall epidemic of COVID-19 in Shaanxi has gradually been mitigated. However, considering the approaching of return to work and study and the increasing of imported cases from other countries, the prevention and control of COVIS-19 in Shaanxi will face new challenges.

Cohort study is one of the basic methods used in epidemiological research. With the development of the etiological analysis of complex diseases such as cardiovascular diseases, large natural population-based cohort study has become a popular topic in medical research. In the process of cohort development, one of the important issues is to ensure the efficiency and safety on data collection. As a database management system, with open source, free clinical research data collection and high quality, REDCap can widely be applied in large population-based cohort studies. This article summarizes the baseline survey and follow-up procedures on cohort studies and introduces a REDCap-system-based solution for data collection and management. Contents on the establishment of data working groups, data collection, cohort follow-up methods and field application are also discussed in this paper, in order to improve the efficiency of data collection and management in cohort study to help the development of cohort study in China.

Objective:To investigate the relationship between triglyceride glucose index (TyG) and body inflammation.Methods:The data were obtained from a baseline survey in population in Xi'an in natural population cohort study in northwest China established in 2018-2019. Based on TG and FPG, TyG/TyG-BMI was constructed to reflect insulin resistance (IR) in the body, and systemic immune-inflammation index (SII) reflecting inflammation in the body was constructed using neutrophil, lymphocyte, and platelet counts. A logistic regression model was used to explore the relationship between the TyG and the SII.Results:A total of 11 491 subjects were included in the analysis. After adjusting for covariates, each unit increase in the TyG increased the risk of high SII by 21% ( OR=1.21, 95% CI:1.12-1.30). The risk of high SII in the group with the TyG in Q4 was 1.34 times higher than that in the group Q1 ( OR=1.34, 95% CI:1.18-1.52). Both sensitivity analysis and subgroup analysis further confirmed the stability of the association between the TyG and the SII. In the population with a BMI ranging from 18.5 to 23.9 kg/m 2, for every unit increase in the TyG as a continuous variable, the risk for high SII increased by 31% ( OR=1.31, 95% CI:1.18-1.45). As a categorical variable, the risk for high SII in the Q4 group was 1.52 times higher than that in the Q1 group ( OR=1.52, 95% CI:1.27-1.83). In a population with BMIs ranging from 24.0 to 27.9 kg/m 2, for every unit increase in the TyG as a continuous variable, the risk for high SII increased by 20% ( OR=1.20, 95% CI:1.07-1.35), and there was no significant difference when it was a categorical variable. Conclusions:The increase in IR is closely related to the development of inflammation in the body, and BMI may regulate their relationship. Early prevention of elevated IR levels before overweight or obesity may have a positive effect on the control of inflammation in the body.

【Objective】 To study the incidence and specificity of platelet antibody in blood donors in Suzhou, analyze the distribution characteristics of platelet antibody in blood donors in this area, and explore the significance of platelet antibody detection in blood donors to reduce the adverse reactions toplatelet transfusion in clinical. 【Methods】 Platelet antibody detection was performed in 2178 blood donors in this area by solid-phase immunosorbent assay. The antibody specificity of the positive samples was analyzed by commercial kit, and the anti-CD36 antibody positive samples were further identified by flow cytometry and gene sequencing. 【Results】 Twelve positive samples were detected by platelet antibody screening, with a positive rate of 0.55%(12/2 178), including 5 males (0.33%, 5/2 178)and 7 females(1.06%, 7/2 178). Among the positive samples, anti-HLA-Ⅰ antibody was identified in 2 cases, anti-CD36 antibody in 1 case, and the antibody specificity was not identified in the other 9 cases. In one case, the positive rate of anti-HLA-Ⅰ antibody PRA was 31.31%(31/ 99), which was mainly specific to anti-B15, anti-B35 and anti-B40. The positive rate of anti-HLA-Ⅰ antibody PRA in the other case was 45.45%(45/ 99), which was mainly specific to anti-A2, anti-A11, anti-A24, anti-A29, anti-A33, anti-A66, anti-B15 and anti-B35. The blood donor with anti-CD36 antibody was type I CD36 deficiency, and 329_330delAC mutation occurred in exon 5. 【Conclusion】 Through antibody screening and specificity identification, the positive rate of platelet antibody in females was significantly higher than that in males(P<0.05). In addition to the common anti-HLA-I antibodies, anti-CD36 antibody was also detected in type I CD36 deficient blood donor. Therefore, the detection of platelet antibodies in blood donors is of certain clinical significance to reduce the adverse reactions to blood transfusion caused by antibodies in platelet products.

【Objective】 To investigate the frequency of CD36 deletion and gene mutation in voluntary blood donors of Zhongshan city, and to explore the possibility of establishing local CD36 negative platelet donor bank. 【Methods】 Platelet CD36 antigen was detected by ELISA in 1 654 voluntary blood donors.Some of the negative samples were confirmed by flow cytometry, and genotyping was also performed. 【Results】 Platelet CD36 antigen was negative in 27 cases, accounting for 1.6% (27/1654), among which 1.6% (18/1149) were males and 1.8% (9/505) were females.No significant difference was noticed between males and females in CD36 antigen deletion cases (P>0.05). Fifteen CD36 negative samples were randomly selected, genotyped and sequenced, with type I deletion in 1 case[ 6.7% (1/15)], type Ⅱ deletion in 14 cases[ 93.3% (14/15)], and gene mutation in exon 3-14 detected in 8 cases. 【Conclusion】 The frequency of platelet CD36 antigen deletion in Zhongshan is comparable to that in other southern regions of China.The establishment of CD36 negative platelet donor bank is conductive to improve the effectiveness of platelet transfusion.

Objective : To observe the effect of hydrogen sulfide( H2 S) on the expression of transforming growth factor⁃β1(TGF⁃ β1) , E ⁃cadherin (E⁃CAD) , Vimentin (VIM) , alpha⁃smooth muscle actin ( α ⁃SMA) during epithelial⁃mesenchymal transformation(EMT) , and to explore the anti⁃fibrosis mechanism of it. Methods : Sixty rats ( male SD) were randomly divided into control group, bleomycin group, NaHS + bleomycin group and prednisolone + bleomycin group , 15 rats per group. 5 rats of each group were sacrificed at random in 7th , 14th and 28th day. The degree of alveolitis and pulmonary fibrosis was observed . The expression of protein and mRNA of TGF⁃ β1 , E ⁃cad , VIM , α ⁃SMA were determined by Immunohistochemi stry and RT⁃PCR. Results : ① HE and Masson staining showed that the lung tissue of fibrosis had the lowest degree in control group. and the most severe in bleomycin group. The lung tissue of NaHS + bleomycin group and prednisolone + bleomycin group also had alveolitis and fibrosis changes , but the degree Were significantly less than bleomycin group. ② The mRNA and protein expression levels of TGF⁃ β1 , VIM and α ⁃SMA in bleomycin group, NaHS + bleomycin group and prednisolone + bleomycin group were all higher than that in control group at 7th , 14th and 28th day ( P < 0. 05 ) , while the expression levels of them in NaHS + bleomycin group and prednisolone + bleomycin group were all lower than that in bleomycin groupat each time (P < 0. 05) , which was significant at 28th day in NaHS + bleomycin. ③ The mRNA and protein expression levels of E ⁃Cad in bleomycin group, NaHS + bleomycin group and prednisolone + bleomycin group were all lower than that in control group at 7th , 14th and 28th day(P < 0. 05) , but the expression levels of E ⁃Cad in⁃NaHS + bleomycin group and prednisolone + bleomycin group were higher than that in bleomycin group at each time(P < 0. 05) , which was significant at 28th day in NaHS + bleomycin. Conclusion H2 S can reduce the degree of pulmonary fibrosis in rats , its mechanism may be related to the down⁃regulation of TGF⁃ β1and the inhibition of the EMT , which can enhance the expression of E ⁃cad and reduce the expression of TGF⁃ β1 , VIM and α ⁃SMA.