张家口坝上四县鼠蚤分布及疫情分析

张家口坝上四县毗邻内蒙,为内蒙古高原的南部边缘,海拔1300～1800m,属典型干草原大陆型季风气候,年均气温1～3℃平均降水量300～400mm。为防止疫情传入和发生,深入了解该地鼠、蚤分布有利于全市鼠防工作的开展。1 鼠类分布 按河北省啮齿动物区系划分。

Animal models for the study of hepatitis C virus infection and replication

Hepatitis C virus (HCV) hepatitis, initially termed non-A, non-B hepatitis, has become one of the leading causes of cirrhosis and hepatocellular carcinoma worldwide. With the help of animal models, our understanding of the virus has grown substantially from the time of initial discovery. There is a paucity of available animal models for the study of HCV, mainly because of the selective susceptibility limited to humans and primates. Recent work has focused modification of animals to permit HCV entry, replication and transmission. In this review, we highlight the currently available models for the study of HCV including chimpanzees, tupaia, mouse and rat models. Discussion will include methods of model design as well as the advantages and disadvantages of each model. Particular focus is dedicated to knowledge of pathophysiologic mechanisms of HCV infection that have been elucidated through animal studies. Research within animal models is critically important to establish a complete understanding of HCV infection, which will ultimately form the basis for future treatments and prevention of disease.

Transient micro-elastography:A novel non-invasive approach to measure liver stiffness in mice

AIM:To develop and validate a transient micro-elastography device to measure liver stiffness(LS) in mice.METHODS:A novel transient micro-elastography(TME) device,dedicated to LS measurements in mice with a range of measurement from 1-170 kPa,was developed using an optimized vibration frequency of 300 Hz and a 2 mm piston.The novel probe was validated in a classical fibrosis model(CCl4) and in a transgenic murine model of systemic amyloidosis.RESULTS:TME could be successfully performed in control mice below the xiphoid cartilage,with a mean LS of 4.4 ± 1.3 kPa,a mean success rate of 88%,and an excellent intra-observer agreement(0.98).Treatment with CCl4 over seven weeks drastically increased LS as compared to controls(18.2 ± 3.7 kPa vs 3.6 ± 1.2 kPa).Moreover,fibrosis stage was highly correlated with LS(Spearman coefficient = 0.88,P < 0.01).In the amyloidosis model,much higher LS values were obtained,reaching maximum values of > 150 kPa.LS significantly correlated with the amyloidosis index(0.93,P < 0.0001) and the plasma concentration of mutant hapoA-□(0.62,P < 0.005).CONCLUSION:Here,we have established the first non-invasive approach to measure LS in mice,and have successfully validated it in two murine models of high LS.

Effect of local administration of cyclosporine A on pe- ripheral nerve regeneration in a rat sciatic nerve transec- tion model

Objective： To assess the effect of cyclosporine A （CsA） loaded in chitosan conduit on bridg- ing the sciatic nerve defects in a rat model. Methods： A 10 mm sciatic nerve defect was bridged using a chitosan conduit filled with 10 μl carrier-drug dilu- tion （10 pg/L CsA）. In control group, the conduit was filled with the same volume of carrier dilution alone. The regene- rated fibers were studied 4, 8 and 12 weeks after surgery. Results： The functional study confirmed faster recov- ery of the regenerated axons in treatment group than control group （P〈0.05）. There was statistically significant differ- ence of the gastrocnemius muscle weight ratios between treatment and control groups （P〈0.05）. Morphometric indi-ces of regenerated fibers showed that the number and diam- eter of the myelinated fibers in CsA-treated animals were significantly higher than those in control group. In immunohistochemistry, the location of reactions to S-100 in CsA group was clearly more positive than control group. Conclusion： CsA loaded in a chitosan conduit results in improvement of functional recovery and quantitative mor- phometric indices of sciatic nerve. It is easily available with- out any complications compared with its systemic administration.

Sequence Similarity Analysis of Non-Self CTL Epitopes and Mouse Proteins Using Sequence Alignment

This research analyzed amino acid sequence similarity between non-self T cell epitopes recognized by mouse antibodies and mouse proteins. Using sequence alignment,we found that only 8 of 1 108 epitopes are highly similar to mouse protein sequences. The result shows that non-self T cell epitopes are not similar or have little similarity to mouse protein sequences. Furthermore,reviewing the related literature,we also found that the eight epitopes would trigger immune responses in some particular environment,which are ignored by T cells in normal condition. The result suggests that no or low-similarity peptide vaccines can reduce the chance of collateral cross-reactions and enhance the antigen-specific immune response to vaccine.

Respiratory face mask:a novel and cost-effective device for use during the application of myocardial ischemia in rats

To shorten operation time and improve survival rate of rats with myocardial ischemia or myocardial infarction,we use a novel device comprised of a face mask and a head/neck retainer in this study.We report the basic design of the novel respiratory face mask(RFM) and evaluate its performance in a rat model of myocardial ischemia.The device is cost-effective and easier to handle than other devices,such as tracheal intubation.Compared with conventional tracheal intubation,we found that RFM shortens operation time significantly while keeping blood indices normal;the mean operation time for rats in the mask group was(32±3) min,and that for the intubation group was(45±7) min(P<0.05).Moreover,the size and shape of the RFM can be changed according to the body weight of rats.In conclusion,RFM is an appropriate device for the establishment of myocardial infarction or ischemia-reperfusion in rats.