Objective To develop a subgroup analysis method that can simultaneously deal with longitudinal data containing measurement errors and dropouts.Methods Subgroup analysis was carried out based on a threshold regression model.A new generalized unbiased estimation equation is constructed by using the independence between repeated measurements to deal with measurement errors and introducing an inverse probability weighting matrix to deal with missing response.Results The computer stochastic simulation shows that the proposed estimation method is effective in dealing with measurement errors and dropouts,and has smaller bias and mean square error than the generalized estimation equation method without correcting measurement errors or dropouts.Conclusion In subgroup analysis,when there are measurement errors in covariables and missing values in response variables,it is usually necessary to deal with the measurement errors and missing values in order to obtain reliable parameter estimation.

This study used the Appraisal of Guidelines Research & Evaluation-Health Systems （AGREE-HS） to demonstratively compare 34 global coronavirus disease-2019 （COVID-19） health systems guidance documents （HSGs） and 6 World Health Organization （WHO） standard HSGs. The comparison involved topic， participants， methods， recommendations， and implementability， with the aim of exploring the characteristics of emergency HSGs. The results showed that the emergency HSGs had an overall average score of 49%， with topic having the highest score， recommendations having the second highest score， and participants having the lowest score. The standard HSGs had an overall average score of 79%， with high scores in all items. The emergency HSGs had lower scores in participants， methods， recommendations， and implementability than the standard HSGs （P<0.001）， while the COVID-19 emergency HSGs developed by the WHO had higher score in topic than the standard HSGs （P<0.05）. Compared with those released by countries， the COVID-19 emergency HSG developed by the WHO showed superiority in all items and overall scores （P=0.000 2）. This indicates that emergency HSGs， represented by the COVID-19 emergency HSG， place equal emphasis on topic and recommendations as standard HSGs but have low requirements in terms of expert participation， evidence support， and comprehensive consideration in the time- and resource-limited context. They have the characteristics of prominent topics， clear purposes， orientation to demand， keeping up with the latest evidence， flexible adjustment， and timeliness， emphasizing immediate implementation effects， weakening long-term effects， and focusing on comprehensive benefits. Additionally， developers， types， and report completeness are important influencing factors.

【Objective】 To investigate the death time of patients with coronavirus disease 2019 (COVID-19). 【Methods】 The death time was calculated and analyzed using individual data and aggregated data through the daily notification of the epidemic situation and the death cases published on the website of the Heath Commission of China and provinces. 【Results】 In the 153 patients who died of COVID-19, the shortest time from onset to death was 4 days and the longest time was 50 days with the mean±standard deviation of (16.7±9.2) days. The median was 14 days and the 95% confidence interval was 4.6-42.9. The shortest time from admission to death was 1 day and the longest time was 50 days with the mean ± standard deviation of (12.1±7.8) days. The median was 11 days and the 95% confidence interval was 2-32.8. The time curve from diagnosis to death was skewed. The death time from diagnosis to death was 0 to 48 days with the mean ± standard deviation of (11.1±8.9) days. The median was 9 days, the interquartile interval was 10.5 days, and the 95% confidence interval was 0-35.4. It took 3 days from onset to admission and 1 day from admission to diagnosis. Aggregated data showed that the time from diagnosis to death of COVID-19 patients in China, China (except Hubei Province), Hubei Province and Wuhan City was 8, 9, 6 and 6 days, respectively. 【Conclusion】 The time from diagnosis to death of COVID-19 patients varied significantly, with the median time of 6-9 days in different regions.

Objective To understand the present status and explore the influencing factors of quality of life(QOL)among medical students,so as to provide a reference for the improvement of the QOL. Methods A total of 1 898 medical students sampled by stratified cluster sampling method were recruited and investigated by wHO-BREF scale. The influencing factors were assessed by t-test and one-way ANOVA. The data were analyzed by SPSS 19.0. Results Scores of the physical,psychological,social relationship,environmental domain of quality of life were 64.99±13.28,61.85± 13.79,61.58±14.53,and 54.91±13.91,respectively. The results indicated grade,monthly income of family,physical training,quality of sleep and history of trauma were the influencing factors of QOL among medical students,and the differences were all statistically significant(P<0.05). Con?clusion The score of environmental domain of QOL among medical students was the lowest. In order to improve the QOL of medical students, schools should take different measures to them according to different grades or monthly income.

Objective To investigate the effects of oral folic acid on cardiac development related gene expression of offspring in an experimental model of coxsackievirus B3(CVB3) infection of pregnant rats. Methods SD female rats were randomized into control group, folic acid group, CVB3 group and CVB3+folic acid group. The female rats were given folic acid by gavage for 2 weeks before pregnancy in folic acid group and CVB3+folic acid group. After conception for 7 days, rat model was established by intraperitoneal injection of CVB3 for 5 days in CVB3 group and CVB3+folic acid group. After nat-ural childbirth neonatal heart was taken and stored in liquid nitrogen. The morphological changes of neonatal rat myocardial tissues were observed by HE staining. The expressions of GATA-4 and NKx2.5 mRNA were detected by RT-PCR and West-ern blot assay. Results There was significant myocardial injury, such as myocardial fiber disarray and myocardial fiber breakage, in neonatal rats in CVB3 group. These damages were improved in CVB3+folic acid group. The expression levels of GATA-4 and NKx2.5 genes in myocardial tissues were significantly lower in CVB3 group than those of control group (P<0.05). The expression levels of GATA-4 and NKx2.5 proteins in myocardial tissues were significantly higher in CVB3+folic acid group than those of CVB3 group (P<0.05). Conclusion CVB3 infection in the early pregnancy inhibited the expres-sion of neonatal rat cardiac development factor. Folic acid supplementation has obvious protective effects on the neonatal rat cardiac development.

We studied medium alkalinization in Salvia miltiorrhiza suspension cultures treated with salicylic acid and the effect of Ca2+ in this process through application of calcium channel antagonists (Verapamil, LaCl3, LiCl, 2-APB) and ionophore A23187. The results show that salicylic acid could induce significant medium alkalinization in S. miltiorrhiza culture. Verapamil and LaCl3 or LiCl and 2-APB, two different groups of calcium channel antagonist, significantly inhibited the medium alkalinization induced by salicylic acid. However, the suppression effect of verapamil or LaCl3 on medium alkalinization induced by salicylic acid was higher than that of LiCl or 2-APB. When two types of calcium channel inhibitor (LaCl3 and 2-APB) were used together, the medium alkalinization induced by salicylic acid was completely suppressed and even reduced the pH in medium. On the other hand, A23187 could promote the medium alkalinization. Based on the results above, we speculated that salicylic acid could induce significant medium alkalinization in S. miltiorrhiza culture, depending on the calcium from both extracell and intracell. Moreover, calcium from extracell plays a more dominant role in this process. Reveal of relationship in this research between Ca2+ and medium alkalinization can provide theory evidence for mechanism of the plant secondary metabolism.
Calcimycin ; pharmacology ; Calcium ; chemistry ; Calcium Channel Blockers ; pharmacology ; Calcium Ionophores ; pharmacology ; Cell Culture Techniques ; Culture Media ; chemistry ; Salicylic Acid ; pharmacology ; Salvia miltiorrhiza ; metabolism ; Verapamil ; pharmacology

Objective To investigate the effect of sevoflurane postconditioning on oxidative stress responses during focal cerebral ischemia-reperfusion (I/R) in rats.Methods Twenty-four male Wistar rats,weighing 240-280 g,were randomly assigned into 3 groups:sham operation group (group S),focal cerebral I/R group (group I/R) and sevoflurane postconditioning group (group SP).The animals were anesthetized with intraperitoneal 10％ chloral hydrate 350 mg/kg.Focal cerebral I/R was produced by middle cerebral artery occlusion.In group SP,3.9％ sevoflurane (1.5 MAC) was inhaled starting from 20 min before reperfusion until 10 min after reperfusion.While 100％ O2 and air were given instead of sevoflurane in groups I/R and S,respectively.Six rats chosen from each group at 24 h of reperfusion were sacrificed and brains were removed for determination of malondialdehyde (MDA),glutathione (GSH),superoxide dismutase (SOD),catalase (CAT),glutathione peroxidase (GSH-Px) and glutathione reductase (GR) levels and for microscopic examination.The cerebral infarct size was measured by TTC staining.Results Compared with group S,MDA level and cerebral infarct size were significantly increased in groups I/R and SP,and GSH,SOD,CAT,GSH-Px and GR levels were decreased in group I/R,and GSH-Px level was decreased in group SP (P ＜ 0.05).Compared with group I/R,cerebral infarct size and MDA level were decreased,and GSH,SOD,CAT,GSH-Px and GR levels were decreased in group SP (P ＜ 0.05).The pathological changes were significantly attenuated in group SP compared with group I/R.Conclusion The mechanism by which sevoflurane postconditioning mitigates focal cerebral I/R injury in rats is related to enhanced antioxidase activity and inhibition of oxidative stress responses.

A total of 1151 subjects were enrolled in this study.Metabolic syndrome (MS) was diagnosed according to the International Diabetes Federation (IDF) criteria.Significant differences in waist circumference,body mass index(BMI),diastolic blood pressure(DBP),systolic blood pressure(SBP),fat mass,Fat％ in different serum TSH levels were found.There were positive relation between fasting plasma glucose,DBP,SBP,and serum FT4 levels,between high density lipoprotein-cholesterol,DBP,SBP,waist circumference,fat mass,Fat％,and serum FT3 levels,even after adjustment for age and sex.Serum FT3 and FT4 levels were higher in the MS group than those in the control group.

This study investigated the relationship between serum thyrotrophin levels and dyslipidemia in subclinical hypothyroid and euthyroid subjects. A total of 110 subjects with subclinical hypothyroidism and 1,240 euthyroid subjects enrolled in this study. Patients with subclinical hypothyroidism had significantly lower high density lipoprotein cholesterol (HDL-C) levels than those who were euthyroid. The lipid profiles were each categorized and mean thyrotrophin levels were higher in subjects in the dyslipidemia subclasses than subjects in the normal subclasses. Thyrotrophin was positively associated with serum triglyceride and negatively associated with serum HDL-C in women. Thyrotrophin was also positively associated with total cholesterol (TC) in the overweight population along with TC and LDL-C in overweight women. In the euthyroid population, thyrotrophin was positively associated with TC in the overweight population. In conclusion, serum thyrotrophin was correlated with dyslipidemia in subclinical hypothyroid and euthyroid subjects; the correlation was independent of insulin sensitivity.
Adolescent ; Adult ; Aged ; Aged, 80 and over ; Cholesterol/blood ; Cholesterol, HDL/blood ; Dyslipidemias/*blood ; Female ; Humans ; Insulin Resistance ; Lipids/blood ; Male ; Middle Aged ; Thyrotropin/*blood ; Triglycerides/blood ; Young Adult

Objective To verify the criteria proposed by National Academy of Clinical Biochemistry(NACB)guidelines in investigating the factors that affect serum TSH determination, and to determine the reference range of serum TSH in iodine-sufficient areas of China. Methods In 2007, 5 348 inhabitants were enrolled from 3 iodine-sufficient areas of Liaoning Province, and were asked to fulfill the questionnaire. Serum TSH, thyroid peroxidase antibody(TPOAb), and thyroglobulin antibody(TgAb)were determined, and thyroid ultrasonography was carried out. Results The distribution of TSH levels was skewed in healthy people and closely fit the curve of Gaussian distribution after logarithmic transformation. The levels of TSH in subjects of 12-19 years of age were significantly higher than those of other age groups(P＜0.01), and no significant difference was found among the latter groups. TSH level in females [(1.68±1.90)mIU/L] was higher than in males[(1.45±1.92)mIU/L, P＜0.01]. The reference range of TSH was 0.43-4.74 mIU/L in males, and 0.48-5.39 mIU/L in females. Family history of thyroid disease, abnormal thyroid ultrasonography, and positive thyroid antibodies were the factors that influenced TSH level. Conclusion The reference range of serum TSH in iodine-sufficient areas of China is established.