SARS coronavims is an emerging virus. A lot of animals could be infected by SARS-CoV and Himalayan palm civets, as one of important hosts, is an ideal animal model. Viral genetic factors have been implicated in the emergence of SARS-CoV, with the suggestion that this virus is a recombinant between mammalian and avian coronaviruses. However, the recombination is unlikely to explain the appearance of SARS in humans.

The teaching methods were explored to improve the quality of medical genetic teaching for foreign students according to the common problems during the teaching process. The negative effects of communication barriers in medical genetic teaching could be reduced by interactive teaching or problem-based learning in groups,in which the ability to resolve problems by themselves could be improved. In order to improve the teaching systematicness and teaching quality,the teaching contents in class should be from simple to deep,covering genetic laws,pathogenesis,diagnosis and control measure of genetic diseases. From the perspective of practical application and combining with the construction of self-de-signed teaching textbook and cases, the quality of medical genetic teaching ultimately could be further improved.

Objective To observe the characteristic of precancerous lesions and early gastric carcinoma with narrow belt imaging technology. Methods The 74 patients were enrolled in this study. The same case was used as self-control. The operation was made in pain-less under anesthesia. When the mirror was advanced to the duodenal descending segment, an ordinary microscope mode was used and the mirror was back to Mallory, the lesions found were recorded, the image was zoomed in with low-fold and observed (1.4,1.6,1.8 times). Suspicious lesions were collected and biopsies were made. Results Chronic gastritis could be commonly found in type A and AB. Mild in-testinalization and mild atypical hyperplasia could be commonly found in mixed type holding type C, type BC and AB. Moderate atypical hy-perplasia could be found in type CD and AC, and heavy atypical hyperplasia in type CD and D. Early gastric cancers (superficial depressed) were seen in type BC and irregular thick type A. Advanced gastric cancers were in type CD, D and C. Helicobacter pylori infection were common in type A and B. Protruded type, sunken type were not easily missed with common endoscopic and NBI. But "for ordinary focus of infection, it was easily missed with common endoscopic, while less with NBI. Conclusion NBI is a simple and safe method, which can be used to find precancerous lesions and early gastric cancer lesions more easily. It will enlaance the diagnosis rate of precancerous lesions and early gastric cancer as positive rate of biopsy was markedly improved.

Objective In order to master the current situation of Keshan disease in Yunnan province and to provide scientific basis for Keshan disease control and prevention. Methods Eighteen villages were selected as the investigation sites in 6 counties across all the Keshan disease wards in Yunnan province,where the residents were investigated. Then,the villages census data was collected,clinical examination aiming mainly on cardiovascular system was carried out,including electrocardiography and X-ray to the suspected patients. Correct diagnose of Keshan disease was made by the Diagnostic Standard of Keshan Disease(GB 17021-1997). At the same time,10 food samples and 10 hair samples for detecting selenium content in every investigation site. Results There were 9818 residents investigated in the 18 investigation sites in 6 counties,and 34 eases of Keshan disease were found,the total incidence rate was 0.35%(34/9818). Among the 34 Keshan disease eases,32 cases were latent Keshan disease,the incidence rate was 0.33%(32/9818); 2 cases were chronic Keshan disease,the incidence rate was 0.02%(2/9818). There was no any acute and sub acute cases be found. Most Keshan disease cases aged from 5 to 14,67.65% (23/34). Abnormal ECG rate was 6.90% (677/9818). Among 56 X-ray films,47 cases had a cardiothoracic ratio less than or equal to 0.50,83.93%(47/56),5 cases from 0.51 to 0.55,8.93%(5/56),4 cases from 0.56 to 0.60,7.14%(4/56). Selenium content was detected in 180 food samples and 180 hair samples. The average food selenium content (mg/kg) was 0.013±0.010,the lowest content in Yongsheng county (0.006± 0.001),the highest content in Tonghai county(0.027±0.009). The average hair selenium eontentwas(0.252± 0.078)mg/kg,with the lowest(0.145±0.043)mg/kg in Yoagsbeng county,the highest (0.297±0.062)mg/kg in Tonghai county. Conclusions The detected ratio of Keshan disease is low in Yunnan province. Most of Keshan disease patients age from 5 to 14. It was presented that the Keshan disease infectious agents were still strong and active. The foodstuffs and hair Selenium content is low in food and hair sample,and varies in different investigation site. It is necessary to supply selenium for prevent Keshan disease in the severe areas.

Objective To investigate the prevalence of integrons in A.baumannii isolates,analyze the correlation between inte- grons and resistance of A.baumannii,and study the resistance genes in integrons.Methods A total of 106 strains of A.bau- mannii were collected to test the antibiotic susceptibility by disk diffusion method.The classification of integrons was per- formed by analyzing the positive PCR products using restriction fragment length polymorphism (RFLP).The variable region of integrons was amplified by integron PCR.RFLP and DNA sequencing were used to analyze the resistance genes in integrons. Results About 52.8% (56/106) of the isolates showed integron positive.PCR-RFLP analysis revealed that they were all class I integrons.About 94.6%(53/56) of the positive strains with integrons owned the variable region,which was confirmed by integron PCR.The sizes of the amplicons ranged from 0.15 kb to 2.8 kb.All together 7 different cassette arrays were detec- ted,including genes coding resistance to aminoglycosides (aadA1,aadA2,aadA5,aadB,aacA4),sulphonamides (dfrⅫ, dfr17),?-lactam compounds (bla_(ara-10)),chloramphenicol (catB-like,catB8),and two open reading frames (orfF,orfI) with unknown function.A novel cassette array orfI-aadA1 was reported,and its GenBank accession number was DQ092497.Conclu- sions Class I integrons are widespread in A.baumannii isolates in Nanjing.The integrons are closely associated with the resist- ance and multidrug resistance in A.baumannii isolates.

Objective Meta-analysis the efficacy and safety of Exenatide and insulin therapy oral hypoglycemic drugs effect of obesity with type 2 diabetes .Methods According to the research purpose to set up the screening of related literature and exclusion criteria; formulatethe searching strategy, through PubMed、the Chinese Biological Medicine Datebase(CBM)、 CNKI、Wanfang Data Knowledge Service Platform, VIP to retrieve all theliterature selection of efficacy and safety by Exenatide oral hypoglycemic drugs and insulin therapy of obese type 2 diabetes mellitus.Choose met inclusion exclusion criteria, the complete data information randomized controlled trial (RCT) as the research object; Apply to the international commonly used Jadad score method to evaluate quality included in the test; To process the relevant data in the test ; Apply the ReviewManager 5.1 software to analysis the extracted research data.Analysis the results and put forward conclusions.Results Participants included 11 RCT , meta analysis results showed that compared with the Exenatide, in terms of reducing fasting glucose ,insulin effect more apparent [MD = 0.35, 95％CI: (0.11, 0.59), P = 0.004)]. In control effect of glycosylated hemoglobin, there was no statistically significant difference[MD=-0.04 ,95％CI:(-0.20,0.11), P=0.58],between Exenatide and insulin. Compared with the insulin, Exenatide reduce BMI more apparent[MD=-2.77,(95％CI: -3.34,-2.20),P<0.00001]; Compared with the insulin, Exenatide reduce insulin resistance index, the effect is more obvious[MD=-1.67,95％CI:(-1.93,-1.41), P<0.00001]; Adverse reaction in the process of treatment, the insulin is more likely to lead to hypoglycemia, [OR = 0.32, 95％ CI: 0.19, 0.54), P<0.0001]; While Exenatide are more likely to lead to gastrointestinal adverse reaction [OR = 4.04, 95％ CI: 2.35, 6.93), P<0.00001).Conclusion According to the Meta-analysis: Exenatide can be used in the treatment of oral hypoglycemic drugs of adult obesity with type 2 diabetes, and obvious effects of treatment of insulin resistance, long-term results still needs a large number of samples of high quality RCT to verify.

Objective To study the current incidence of Keshan disease in Yunnan Province,and provide scientific basis for Keshan disease(KD) prevention and control. Methods Based on the Scheme of KD Surveillance, 16 villages in 11 counties were chosen as surveillance sites by the historical data. An survey was made to the residents in the 16 surveillance sites by filling in the questionnaire, inquiry medical history, clinical examination, electrocardiogram and 2 meters post-anterior chest X-ray for suspected cases. KD cases were diagnosed according to the Diagnostic Criteria for Keshan Disease(GB 17021-1997). The prevalence data of KD in the whole province were collected from the KD case report in 2007 and the trace surveys. Results There were 6877 residents in 16 surveillance sites of 11 surveillance counties and totally 39 KD cases were diagnosed with a detection ratio of 0.57% (39/6877). The detection ratio of latent and chronic KD were 0.41%(28/6877) and 0.16%(11/6877), respectively and no acute or subacute cases were found. The cases aged 5 to 14 years old accounting for 66.67% (26/39). Electrocardiogram examination of 6877 residents were made and 5.25% (361/6877) abnormal electrocardiograms were detected in the 16 surveillance sites. Fifty-five people were checked by chest X-ray and there were 31 cases with heart-chest ratio ≤0.50, 16 cases with heart-chest ratio from 0.51 to 0.55 and 8 cases with heart-chest ratio from 0.56 to 0.60. The prevalence rate and incidence rate of chronic KD were 4.24 per 100 000 and 0.50 per 100 000 in Yunnan. No acute or subacute cases were found and the latent cases were listed. The prevalence rate and incidence rate were 7.76 per 100 000 and 1.18 per 100 000 in the 16 surveillance sites. Conclusions The incidence of KD is low incidence in Yunnan Province. Higher ineidence of chronic KD was detected in the some areas and the corresponding control measures need to be adopted.

Objective To report four patients with secondary α-dystroglycanopathy caused by guanosine diphosphate-mannose pyrophosphorylase-B ( GMPPB ) gene mutations and review the literature aiming to analyze the clinical manifestations , muscle image , molecular pathology and genetic characteristics of the disease.Methods The medical history , physical examination , electromyography and other clinical data of four patients with secondary α-dystroglycanopathy from two families were collected and retrospectively reviewed from 2009 to 2017.Case 1 ( proband of pedigree 1) and case 2 ( proband of pedigree 2) were then further analyzed with muscle imaging , muscle pathology and targeted next generation gene sequencing (NGS).Results Four patients came from two families (three from the same pedigree), two males and two females, with an onset age of 17 -18 years.All four cases presented as limb-girdle muscular dystrophy (LGMD) overlapping with congenital myasthenic syndrome (CMS) characterized by evident proximal limb weakness in early adulthood and fluctuating muscle weakness .They all had delayed motor milestone and did not perform well in physical education since childhood . Serum creatine kinase was elevated markedly (1877-5275 U/L).Myogenic changes on electromyography and marked attenuation on three Hz repetitive nerve stimulation were observed in all patients .Muscle MRI showed prominent involvement of bilateral hamstrings in case 1 and case 2.Muscular dystrophic patterns were demonstrated on muscle biopsies . Targeted NGS revealed two compound heterozygous missense mutations in GMPPB for each case .Case 1 carried c.860G>T (p.R287L)/c851T>C (p.V284L).Case 2 and his two affected sisters (case 3 and case 4) carried c.1097A >G ( p.N366S)/c.589G >T ( p.V197F) .All of these mutations were novel variants and pedigree analysis suggested that the two mutations were from parents .Compared with normal controls, immunohistochemistry and Western blotting showed significantly decreased expression of α-dystroglycan in the muscle tissue from case 1 and case 2.The myasthenic symptoms of all four patients were improved to varying degrees after treatment with pyridostigmine bromide . Conclusions Mutations in GMPPB can lead to dysfunction both in muscle and in neuromuscular transmission causing overlapping between LGMD and CMS phenotypes . Cholinesterase inhibitors can partly improve the symptoms of myasthenia in such patients .

BACKGROUND:The molecular mechanism of traumatic deep vein thrombosis is complex.Numerous studies focus on clinical observation and epidemiology,but its molecular mechanism has not been a new breakthrough.OBJECTIVE:By use of gene array technology,this study was aimed to study the expression changes of matrix metalloproteinases in rat models of traumatic deep vein thrombosis,and to explore the roles of matrix metalloproteinases in traumatic deep venous thrombosis.METHODS:A total of 150 SD rats,SPF grade,of 8-12 weeks old,body weight of 250-300 g,were divided at random into normal control group (n=10) and model group (n=140).Rat traumatic deep venous thrombosis models were set up by clamping the femoral vein and fixing the bilateral hind limbs,and the fixation of hip spica with plaster bandage was conducted in each group.Then rats were divided into 7 subgroups:post-traumatic 0.5 hours,post-traumatic 2.5 hours (initial period of thrombosis),post-traumatic 25 hours (thrombogenesis at thrombotic crest-time),post-traumatic 25 hours non-thrombogenesis at the thrombotic crest-time),post-traumatic 72 hours (thrombus resolution),post-traumatic 72 hours thrombus insolution) and post-traumatic 168 hours (nonthrombosis).At the corresponding phasess,the femoral vein tissues were incised,and total RNA of femoral vein was extracted using Trizol one-step method.Applying Genechip Rat Genome 430 2.0 genechips,the gene expressions in femoral vein were detected in different groups.The rate of traumatic deep venous thrombogenesis and non-thrombogenesis,the rate of thrombi solution and insolution were observed;the expressions of matrix metalloproteinases and tissue inhibitor of metalloproteinases at different time phases was detected by gene array data analysis.RESULTS AND CONCLUSION:Three model rats died and the remaining 147 rats were involved in the final analysis.At the post-traumatic 25 hours,the rate of thrombogenesis was 50.5% and nonthrombogenesis was 49.5%.To the post-traumatic 168 hours,the rate of thrombus solution was 56.7% and thrombus insolution was 43.3%.Both matrix metalloproteinases and tissue inhibitor of metalloproteinases exhibited differential expressions in the course of traumatic deep venous thrombosis.Under the thrombus insolution state,matrix metalloproteinases continued to show a high expression,tissue inhibitor of metalloproteinase expression was down-regulated in the thrombus formation,was significantly inhibited in the thrombus insoluUon process.In the process of traumatic deep vein thrombosis and insolution,matrix metalloproteinase was closely related to traumatic deep vein thrombosis,the matrix metalloproteinase/tissue inhibitor of metalloproteinases are likely to affect the biological state of thrombosis.

Objective To investigate the effects of output power,action time and radiofrequency(RF) needle on the cool-tip radiofrequency ablation(RFA) by experimental tools and to determine the value of ultrasonography in size evaluation of RFA zone.Methods The cool-tip RFA to fresh calf liver were monitored by ultrasound.The experiments by single electrode needle were performed with different combination of output power (80 W,120 W) and time (5 min,8 min,10 min).The cluster needle was used for assessment at 5 min with different output power(80 W,120 W).After the end of trial,the longitudinal specimens were cut open.The view and size of the ablation zone were recorded with naked eyes.The pathological changes displayed by optical microscope were recorded as well.Results The measurement of ablation zone with naked eyes showed with the ablation zone expanded with time in 80 W-power cases,but the pace of expansion slowed down,but in 120 W-power cases,expansion of the ablation zone was not obvious; the ablation zone in 120 W-power was bigger than that in 80 W-power at 5 min,their difference decreased with time,and the ablation zones were similar at 10 min.The cluster needle can produce ablation zone with lesser aspect ratio than that of single electrode needle,consequently similar to circle.Ultrasonic measurement of the ablation zone had real discrepancy.Most of longitudinal diameters were greater than the real ones,while in large ablation lesions,vertical diameters were often less than the real ones.Under optical microscope,no change could be found in shape and structure of the cells in ablation zone.Conclusion The output power and performing time have impact on ablation.The high-power output increased heat production as well as reduction of heat conduction.Compared with single electrode needle,the cluster needle produced ablation zone closer to real hepatic tumor,thus has more reliable effect to small hepatocellular carcinoma with diameter around 2 cm.The ultrasond has a great significance in RFA guidance,but it could not accurately define the border of ablation zone.