Application of mendelian randomization methods in causal inference of observational study / 中华预防医学杂志

Mendelian randomization (MR) approach follows the Mendel′s law of inheritance, which is called "Parental alleles randomly assigned to the offspring", and refers to use genetic variants as an instrumental variable to develop causal inference between the exposure factor and the outcome from observational study. In recent years, with the rapid development of genome-wide association study (GWAS) and various omics data,the disclosure of a large number of aggregated data provides an opportunity for the wide application of MR approach in causal inference. We introduce three methods widely used in MR and then apply them to explore causal relationship between blood metabolites and depressive. The advantages and disadvantages of three methods in causal inference are compared in order to provide reference for the application of MR in observational studies.

Estimation on the individual treatment effect among heterogeneous population, using the Causal Forests method / 中华流行病学杂志

Objective@#This project aimed to explore the effectiveness of estimating individual treatment effect on real data, among the heterogeneous population, with Causal Forests (CF) method, to find out the characteristics of heterogeneous population.@*Methods@#We designed and conducted four computer simulation schemes to verify the effect of estimating on individual treatment, using the CF under four different environments of the treatment effects. Real data was then analyzed for the catheterization on right heart.@*Results@#Results from the simulation process showed that the values on individual treatment effect that were estimated by causal forests were consistent with the population effect as well as in line with the expected distribution under the setting of four different effect values. Results of real data analysis showed that values of individual treatment effect among most patients appeared positive, so the use of RHC could cause an increase of the '180-day mortality rate’ in the sampled population. Patients with lower predicted probability of 2-mo survival and albumin were more likely to have a lower risk of death after using the RHC.@*Conclusion@#CF method could be effectively used to estimate the individual treatment effect and helping the individuals to make decision on the receipt of treatment.

Effect of ventilation with low tidal volume and positive end-expiratory pressure in different periods on postoperative pulmonary function and short-term prognosis in elderly patients with abdominal surgery / 临床麻醉学杂志

Objective To observe the effects of ventilation with low tidal volume and positive end-expiratory pressure (PEEP)in different periods on the postoperative pulmonary function and short-term prognosis in aged patients undergoing abdominal surgery.Methods Sixty aged patients undergoing selective open abdominal surgery scheduled for general anesthesia,21 males and 39 fe-males,were randomized into 3 groups (n =20).Patients in group A received PEEP 1 h after the be-ginning of surgery;patients in group B received PEEP 1 h before tracheal extubation;patients in group C received PEEP intraoperatively.The secretion score in preoperative,postoperative 24 h and 72 h respectively,and the arterial blood gas analysis indexes (PaCO 2 ,PaO 2 ,A-aDO 2 ,PaO 2/FiO 2 calculation)in postoperative 1 h and 24 h were recorded.Results Compared with preoperative,in postoperative 1 h,PaCO 2 increased obviously in all groups,PaO 2 decreased in group B,A-aDO 2 in-creased in group A (P <0.05);in postoperative 24 h,PaCO 2 was significantly increased in group B and C,PaO 2/FiO 2 decreased in group B (P <0.05).Compared with postoperative 1 h,in postopera-tive 24 h,PaCO 2 and A-aDO 2 decreased obviously in group A (P <0.05).There were no differences in postoperative secretions score in between the 3 groups.Conclusion Low tidal volume combined short-range PEEP in different periods of surgery may improve postoperative pulmonary oxygenation. But they had no obvious help with postoperative pulmonary complications.

Investigation of the awareness in laboratory biosafety among teachers and students of medical colleges in Jiangsu Province / 中华疾病控制杂志

Objective To investigate the biosafety-related knowledge level of teachers,technicians and graduate students of medical colleges in Jiangsu province and to explore policy for management of laboratory biosafety in medical colleges.Methods In total of 550 teachers,technicians and graduate students from 5 full-time medical colleges were enrolled using a multiple-stage stratified random sampling method.Each subject was asked to complete questionnaire consisting of laboratory biosafety rules,safety consciousness,route of transmission,waste management and biosafety training,etc.Results The general awareness rate was 54.38%.The percentage of awareness in laboratory biosafety rules,safety consciousness,route of transmission were 27.58%,27.68% and 10.23%,respectively.The awareness rate in reagents toxicity was the lowest(7.21%).However,the awareness rate in protecting rules and waste management were as high as 83.77% and 76.90%,respectively.About 96.30% of the respondents considered that it would be necessary to launch a biosafety course in medical colleges.Conclusions The results showed that the awareness in laboratory biosafety among teachers and students of medical colleges still need to be improved.Propaganda and training of laboratory biosafety should be performed regularly to improve the general awareness and strengthen management.