Isolation and identification of plague phage from Suncus murinus in Yunnan Province and its epidemiological significance / 中华地方病学杂志

Objective:To study the basic situation of Yunnan Province Suncus murinus carrying plague phage and to explore its epidemiological significance. Methods:From 2015 to 2018, a survey of plague host animals was carried out in 10 investigation sites in the historical plague foci, new plague foci (after 1982) and stubborn plague foci of domestric mouse in Yunnan Province. The plague phage was isolated and cultured from the intestinal specimens of Suncus murinus. The growth of plaque was observed by double-layer plate method, and the morphology and structure of plague phage were observed under electron microscope. At the same time, intestinal samples were taken to detect the structural gene caf1 of F1 antigen of Yersinia pestis. Results:In this study, a total of 157 Suncus murinus were captured and 16 strains of plague phage were isolated, with a total isolation rate of 10.19%. There was no difference in plague phage isolation rate between historical plague foci (10.00%, 1/10) and stubborn plague foci (16.22%, 12/74), new plague foci (4.11%, 3/73, χ 2 = 0.00, P = 0.965; Fisher test, P = 1.000). However, there was a difference in plague phage isolation rate between stubborn plague foci and new plague foci (χ 2 = 5.88, P = 0.015). There was no significant difference in the isolation rate of plague phage among different sex, growth period and habitat ( P > 0.05). The plaque morphology of the isolated plague phage was diverse, of which four strains were myotavirus phages; and all samples were negative for F1 antigen structural gene caf1. Conclusions:Suncus murinus is widely distributed in the domestic mouse plague foci in Yunnan Province, and the animals carry a certain number of plague phage. Regular surveillance of Suncus murinus and their plague phage has a certain guiding significance for the surveillance and early warning of plague in Yunnan Province.

Commonly Used Vomiting Animal Models / 中国实验方剂学杂志

Vomiting is a common clinical symptom. Long-term severe vomiting could seriously reduce the life quality of patients, so it is necessary to be intervened with antiemetic drugs. Traditional Chinese medicine has a long history in the treatment of vomiting with remarkable a curative effect. It has the advantages of multi-component, multi-target and multi-system synergistic antagonism. However, due to the active substance and unclear mechanism, it is urgent to adopt an internationally recognized vomiting model system to evaluate the antiemetic characteristics, elucidate the vomiting mechanism, and provide reference for better clinical application. Therefore, this paper systematically introduces several vomiting animal models that are widely used at home and abroad. According to the authors' own experimental experience, this paper focuses on the rat and mice pica models for reference of relevant researchers. Specifically, ferrets are an internationally recognized ideal vomiting animal model, and the golden standard for evaluating the effects of antiemetic drugs, suncus murinus is the smallest mammalian vomiting model. Rodents have no vomiting reflexes, but studies have shown that its pica behavior is equivalent to the vomiting behavior of other species. Because the easy availability and operation, the model has been promoted and applied in mainland China. Guizhou mini-pig model is a self-developed medium-sized mammalian vomiting model with a similar anatomical structure and vomiting characteristics to human, and worthy of popularization and application. In conclusion, different vomiting models have their own characteristics that need to be optimized according to the purpose of experiments and samples.

Review and evaluation of vomiting animal models / 中国药理学通报

Only limited species of animals with vomiting reflex are available for the vomiting animal models. From 1980s some new vomiting models have been developed, such as in ferret, which is convinced its vomiting behavior is closest to human being; Suncus murinus(house musk shrew)is the smallest mammal used in vomiting model and the most sensitive animal to motion sickness; rat, although without vomiting reflex, but consuming non-nutritive substance such as kaolin(pica) can be considered to be an index of nausea and vomiting; mink, from the same genus as ferret, can be a substitute of ferret in vomiting model. It should be noted that the sensitivity profile to different emetic stimuli is species-dependent.