0.05).But transitional PBL had much priority in enhancing students' learning interests. Conclusion The applicational of transitional PBL requires to be further deepened and improved in the realm of medical education.

ObjectiveTo investigate the epidemic situation of brucellosis in Datong city, and to provide scientific evidence for making appropriate prevention and control measures. MethodsSurveillance data of human brucellosis in 7 countris and 4 districts in Datong city between 2006 and 2009 were collected, throng the national network straight quote system in an infectious diseases. Excel database was established and all data were statistically analyzed. Incidence of brucellosis in local population was analyzed. The regional distribution, time distribution,occupation, age and sex distribution were analyzed. Epidemic characteristics and trend of brucellosis in Datong city were summarized. Results A total of 5195 cases of brucellosis patients in Datong were found between 2006 and 2009, the average incidence rate was 57.51/10 million. All counties had the disease, and the onset of the disease mainly in the spring and summer. Most cases were young males. Farmer case was 81.67％(4243/5195) of the total patients. ConclusionsFrom 2006 to 2009, epidemic characteristic of Datong human brucellosis ishigh-low-high(incidence). We suggests the Department concerned to strengthen the prevention and control of the disease in some counties, focusing on spreading of disease prevention and control knowledge among farmers and increase their self-protection awareness.

This project is targeted on exploring some improving approaches to isolate and culture the microorganisms which are difficult to be isolated and cultured through the conventional ways. The results showed that betaine, sodium pyruvate, SOD and catalase are helpful for increasing the total number and variety of isolated strains. A kind of combined method was also used to isolate the micro-colony which can not be seen by naked eyes on the plates. Totally 52 Actinomycetes and 103 bacteria and 17 fungi were obtained from 4 soil samples using the above methods. 4. 325% microorganisms were obtained as positive strains to inhibit the growth of some kinds of test bacteria, which is higher than the percent using generally isolated ones. These microbial natural products may remain an important resource for the drug discovery.

To explore the new method of discriminating Cistanche deserticola, Cynomorium songaricum and Orobanche pycnostachya by using PCR amplification of specific alleles. 30 samples of the different C. deserticola, 21 samples of C. songaricum and O. pycnostachya were collected. The total DNA of the samples were extracted, the ITS sequences from C. deserticola, C. songaricum and O. pycnostachya were amplified by PCR and sequenced unidirectionally. These sequences were aligned by using ClustulW. Specific primer was designed according to the ITS sequences of specific alleles, and PCR reaction system was optimized. Additionally, compare with the identification of specific PCR method and DNA sequence analysis method. The result showed that the 331 bp identification band for C. deserticola and the adulterants not amplified bands by a single PCR reaction, which showed good identification ability to the three species. PCR amplification of specific alleles can be used to identify C. deserticola, C. songaricum and O. pycnostachya successfully.
Alleles ; Cistanche ; classification ; genetics ; DNA Primers ; genetics ; DNA, Intergenic ; genetics ; DNA, Plant ; genetics ; Drug Contamination ; prevention & control ; Phylogeny ; Polymerase Chain Reaction ; methods

Objective To improve the method of blood collection from external jugular vein in rats,so as to repeatedly obtain blood samples of high quality and to meet the special requirements of the experiment.Methods The experimental rats were anesthetized by intraperitoneal anesthesia,and the jugular vein was fully exposed with special fixed method.Whereafter,the blood samples were collected by disposable vacuum blood vessels.Results This method had little traumatic effect.The blood samples were collected from 60 rats at an interval of 14 days with 1.8 to 2.5 mL each time.The success rate was above 95％,and the normal activities of the rats were not apparently affected.This vacuum blood collection method guaranteed the quality of serum,and the veracity of blood detection and analysis were also significantly improved.Conclusion On the basis of the principle of animal welfare,the improved rat jugular vein blood collection method has the advantages of simple operation,less trauma,large blood collection,high blood sample quality aod so on,which can ensure the effect of the special experiment.

Objective To analyze the effect of endoscopic ultrasonography guided interstitial iodine 125 seed implantation in treatment of unresectable pancreatic cancer and migration of implanted seeds. Methods A total of 17 patients with unresectale pancreatic cancer underwent endoscopic ultrasono- graphy guided interstitial iodine seeds implantation.The therapeutic plan system was used to calculate the number of implanted seeds before procedure.The patients were followed-up monthly and tumor alteration and migration number or loss of implanted seeds were investigated by abdominal plain film.Results Io- dine 125 seeds were successfully implanted in all patients under endoscopic ultrasonography. Before treatment,the median size of tumor was 5.4cm(ranged from 3.7 to 9.0cm)and the number of implan- ted seeds was 27,with median 14(ranged from 7 to 24)once for 2 times.The mean radioactivity per seed was(0.6894?0.016)mCi.The patients were follow-up of 2 to 14 months(mean 4.8 months). Three months after implantation,partial relief was observed in 5 patients(29.4%),no change in 7 patients(41.2%)and progressing in 5 patients(29.4%).The implanted seeds migrated into spleen in 1 case, into liver in 1 case and into bowel in 3 cases.The seeds loss was found in 4 patients.Conclusions Endoscopic uhrasonography guided interstitial implantation of iodine 125 seeds in treatment of advanced pancreatic cancer may significantly inhibit tumor growth,and attention must be paied on the complications of seeds migration or loss,which will impair the nearby organs because of its radioactivity.

Objective We examined the in vivo effect of the antisense or/and decoy oligonucleotide of nuclear factor-?appa B (NF-?B) on balloon-injured smooth muscle cell proliferation and MMP-9 in the carotid artery of rats. Methods Sprague-Dawley rats underwent balloon-dilation injury of the left carotid artery. Rats were divided into 7 groups(n=18) and each group included 6 time points (6 h and 1,3,5,7,14 d)(n=3). Results The mean intima/media ratio increased significantly in sense group、scramble group and model group and reached the maximum at 7 d after rat injured carotid artery, compared with normal group, antisense group, decoy group and decoy plus antisense group(P

Objective To analyze the results of the Objective Structured Clinical Examination(OSCE) of medical interns in Department of Gynecology and Obstetrics,and to assess the role of OSCE in clinical teaching and practice. MethodsAtolal of 104 medical interns of five-year education program in 2002 and seven-year education program in 2003 in School of Medicine had taken part in OSCE of gynecology and obstetrics.The OSCE consisted of six stations: gynecologic examination,obstetric examination,oral test,interrogation of standardized-patients(SP),drawing partogram,and non-stress test(NST) explanation.After gathering the data of each station,the software of SPSS 11.0 was used to make statistical analysis. Results The median scores were as follows: 92.0 for gynecologic examination,91.0 for obstetric examination,83.5 for oral test,80.0 for interrogation of SP,80.0 for drawing partogram,and 70.0 for NST explanation.There was no significant impact of familiarity to OSCE on the results of the test.The results showed that medical interns did good job in basic performance,but lack of clinical practice skills in some complicated practice of gynecology and obstetrics.Conclusion The grading system and stations setup of OSCE in Department of Gynecology and Obstetrics in Shanghai Sixth People's Hospital show objectivity and equity.The OSCE can be widely applied in the after-department examination and even graduation examination.

Abstract: Objective　To analyze the nucleic acid detection results of severe acute respiratory syndrome corona virus-2 (SARS-CoV-2) by droplet digital PCR (ddPCR) and compare with the detection results of real-time fluorescence quantitative RT-PCR (qRT-PCR), so as to evaluate the advantages and disadvantages of detection, and to provide data support for optimizing the nucleic acid detection scheme of SARS-CoV-2. Methods　According to the SARS-CoV-2 specific primer probe published by the China Center for Disease Control and Prevention, a ddPCR detection method for SARS-CoV-2 was designed. One sample was selected for sensitivity test after gradient dilution; six respiratory virus nucleic acid positive samples including seasonal H3N2 influenza virus and SARS-CoV-2 positive samples were selected for specificity test; five SARS-CoV-2 positive samples were selected for repeatability test; in addition, 30 positive and 20 negative SARS-CoV-2 samples were selected for multiple clinical samples testing, and the results were analyzed and compared with those of qRT-PCR. Results　The ddPCR method can specifically detect SARS-CoV-2, and directly obtain the original copy number of the sample target gene to achieve accurate quantification; the sensitivity test of gradient dilution positive samples showed that qRT-PCR detected target genes in part of the 10-5 dilution of samples, and no target genes were detected in 10-6 dilution, while ddPCR detected all target genes in both 10-5 and 10-6 dilution of samples. The detection limit of ddPCR was two orders of magnitude higher than that of qRT-PCR, and the sensitivity was higher than that of qRT-PCR; in the comparison of the repeatability test results of the two methods, the coefficient of variation of ddPCR was 1.266%-11.814%, lower than 1.729%-26.174% of qRT PCR, and the repeatability was higher than qRT-PCR; among 50 clinical samples, 30 positive samples of confirmed cases of Coronavirus Disease 2019 (COVID-19) were detected by both methods, SARS-CoV-2 was successfully detected by both methods, and 20 negative samples of COVID-19 were detected by both methods, and the results were negative, with a coincidence rate of 100.00% (50/50). Conclusion　The ddPCR method can accurately quantify SARS-CoV-2 with strong specificity, and its sensitivity and repeatability are higher than those of qRT-PCR, but it also has certain detection limitations and is more suitable for the detection of low load samples. In the actual detection, the two methods can be reasonably combined to improve the detection accuracy.

OBJECTIVETo discuss the unsuccessful reasons and the preventive methods of the unsuccessful clinic cases.

METHODSThe retrospective analysis was carried on the 80 prosthesis in 70 patients from 1994 to 2001 which were suffered with unsuccessful results after the restoration of the metal crowns and bridges.

RESULTSThere were 68 teeth which had collapsed or broken. 20 teeth had the post loosing or shedding. Root breaking, food impaction, unharmony colors of porcelain and the changing color of gingival were 3, 3, 6 and 2 teeth.

CONCLUSIONIt is necessary to select suitable repairing materials and operate correctly for preventing the occurring of the unsuccessful results in the porcelain-fused-to-metal-crowns and bridges.