河豚毒素生物定量方法的评价

河豚毒素是一种神经毒,其生物测定方法有最小致死量法、小鼠单位法、死亡时间倒数曲线法。本文旨在对这三种方法进行初步评价;实验结果:三法之间无显著性差异p>0.05;但小鼠单位法具有设计周密合理,时间查对精确,能体现小鼠死亡时间与毒量间的关系,可选时间范围广,动物重量可选范围大,比较节省动物和时间的优点,值得推广应用。     

Health and Economic Evaluation of Vaccination Against Pertussis in China: A 40-Year Analysis

ObjectivesThis study aimed to evaluate the health and economic impact of diphtheria, tetanus, whole-cell pertussis vaccine (DTwP) and diphtheria-tetanus-acellular pertussis vaccine (DTaP) vaccination on pertussis prevention and control in China during the 40 years from 1978 to 2017.MethodsWe conducted cost-benefit analyses with a decision tree model populated with historical vaccination coverage levels and pertussis incidence and mortality data from before 1978 and during 1978 to 2017. We modeled 40 birth cohorts from birth until death. Costs and benefits were estimated from direct cost and societal perspectives (direct and indirect costs). Costs and benefits were adjusted to 2017 US dollars (USD), and future values were discounted at a 3% annual rate. We calculated net benefit values (net savings) and benefit-cost ratios of pertussis vaccination of children younger than 5 years. We conducted sensitivity analyses by varying key parameters within plausible ranges.ResultsWithout DTwP and DTaP vaccination, there would be an estimated 115.76 million pertussis cases and 426 650 pertussis deaths in the 40 cohorts. With DTwP/DTaP vaccination, pertussis cases and deaths were decreased by an estimated 92.57% and 97.43%, saving 46 987.81 million USD in direct costs and 82 013.37 million USD from societal perspective. Pertussis vaccination program costs were 2168.76 million USD and 3961.28 million USD from direct cost and societal perspectives. Benefit-cost ratios were 21.67:1 from the direct cost perspective and 20.70:1 from the societal perspective. Sensitivity analyses showed the results to be robust.ConclusionsOver the lifetime of 40 birth cohorts, China’s immunization program is preventing 93% of pertussis cases and 97% of pertussis deaths, resulting in substantial savings to the healthcare system and society.     

A nomogram to predict early postoperative recurrence of hepatocellular carcinoma with portal vein tumour thrombus after R0 liver resection: A large-scale,multicenter study

BackgroundPortal vein tumour thrombus (PVTT) is a significant poor prognostic factor for hepatocellular carcinoma (HCC). Patients with PVTT limited to a first-order branch or above of the main portal vein (MPV) could benefit from R0 liver resection (LR). A nomogram is needed to predict early postoperative recurrence (ER) in HCC patients with PVTT and to guide selection of these patients for adjuvant therapy to reduce postoperative recurrence risks.MethodsHCC patients with PVTT limited to a first-order branch or above of the MPV after R0 LR as an initial therapy were included. A nomogram using data from a retrospective training cohort was developed with the Cox regression model. The model was tested in a prospective internal validation cohort and three external validation cohorts.ResultsOf 979 patients, 657 developed postoperative ER (67.1%). ER occurred in 165 of 264 patients (62.5%) in the training cohort, 146 of 218 patients (70.0%) in the internal validation cohort, and 204 of 284 patients (71.8%), 77 of 113 patients (68.1%), and 65 of 100 patients (65%) in the three external validation cohorts, respectively. The nomogram included the following variables: hepatitis B surface antigen (HBsAg), PVTT, HBV DNA, satellite nodules, α-fetoprotein, and tumour diameter. The ROC were 0.836, 0.763, 0.802, 0.837, and 0.846 in predicting ER in the five respective cohorts.ConclusionA nomogram was developed and validated to predict postoperative ER in patients with HCC with PVTT after R0 LR. This nomogram could select appropriate patients with high ER risks for postoperative adjuvant therapy.