Objective To identify homogenous clones of S.flexneri 2a, using gene distribution polymorphism of Shigella enterotoxinl and Shigella enterotoxin2 in a shigellosis outbreak by S.flexneri 2a. Methods 93 strains of S.flexneri 2a isolated from different areas, at different time were detected by Shigella enterotoxin1 and Shigella enterotoxin2 gene polymerase chain reaction to identify genetic type of S.flexneri 2a. Results The 93 strains of S.flexneri 2a were divided into 4 clones: ShET1(-)/ShET2(+)for 12 strains,ShET1(+)/ShET2(-)for 14 strains,ShET1(+)/ShET2(-)for 59 strains, ShET1(-)/ShET2(-)for 8 strains. Conclusions It is believed that Shigella enterotoxin1 and Shigella enterotoxin2 gene PCR analysis is a simple method for the primary screening of S.flexneri 2a.

Objective To evaluate the effect of behavioral intervention on changing knowledge, attitude and practice (KAP) about AIDS among the migrant workers in railway construction sites. Methods Health education and behavioral intervention on AIDS were carried out among the migrant workers for 4 to 5 months, who were clusteredly sampled from two railway construction sites, in the forms of mini-media, peer education and so on. Questionnaire survey was conducted among them before and after the intervention. Results The results showed that the knowledge awareness of the migrant workers on the transmission routes, preventions of AIDS and self-protection consciousness increased significantly by comparing the indexes of 943 pre-intervention with those of 671 post-intervention workers. After intervention procedures, the rate of those workers who would adopt negative attitudes towards the HIV infected persons because of fear and discrimination was decreased from 9.8% and 10.5% to 6.3% and 3.5% (both P

BACKGROUND: Marrow stromal cells (MSCs) own the characteristic of migration. However, the mechanisms underlying the migration of these cells remain unclear. OBJECTIVE: To explore the roles of stromal cell-derived factor-1 (SDF-1) and its receptor CXCR4 in trafficking of MSCs migration. DESIGN, TIME AND SETTING: The in vivo cytology experiment was performed at Department of Anatomy, National University of Singapore from March 2007 to June 2007. MATERIALS: MSCs were isolated and purified from a Wistar neonatal rat. Forty adult female Wistar rats were randomly divided into sham operation and experimental groups, with 20 animals in each group. METHODS: The chemotaxis assay was performed at a 48 well Boyden chamber, and a total of 25 μL SDF-1 was added to the lower layer of chamber, covered with 8 μm polycarbonate membrane filter; SDF-1 cultured in DMEM conditioned medium was served as a blank control group. Cell concentration was regulated to 1.5×109L-1/L. 50 μL and cell suspension was added into the upper layer of chamber, cultured at CO2 incubator with temperature of 37 ℃ for 10 hours. Rats in the experimental group were prepared for transected spinal cord injury models, and in the sham operation'group, only the vertebral plate was opened. 1.0 mL (1×109L-1/L) MSCs suspension labeled with 5-(and-6)-carboxyfluorescein diacetate succinimidyl ester (CFDA-SE) was injected through internal jugular vein at 1 hour after completely transected spinal cord. MAIN OUTCOME MEASURES: Expression of chemokine receptor CXCR4 in MSCs, as well as the effect of SDF-1 on the migration of MSCs was observed by immunofluorescence, change of SDF-1 in lesion site of spinal cord was detected by real-time PCR analysis, as well as the in vivo migration of intravenously injected MSCs was detected by fluorescence microscopy. RESULTS: The pudfied MSCs were positive to CXCR4. Compared to the blank control group, SDF-1 with concentrations of 5, 50, and 500 μg/L could accelerated the migration of MSCs (P < 0.05), which reached a peak with concentration of 500 μg/L. The expression of SDF-1 RNA was obvious increased in the experimental group than that of the sham operation group (P < 0.05), and returned to a normal level at 14 days. At 2 weeks after cell injection, the number of MSCs migrated to the lesion site of completely transected spinal cord was significant increased than sham operation group (P < 0.05). CONCLUSION: SDF-1 may contribute to MSCs migration in vitro and in vivo. SDF-1 and its receptor CXCR4 are involved in the migration of injected MSCs to the lesion site of completely transected spinal cord.Ding P, Xue LP, Yang ZY, Wang CQ, Wang JH, Feng ZT, Ling EA.Chemokine stromal cell-derived factor-1 and its receptor CXCR4 mediate migration of marrow stromal ceils into the lesion site of completely transected spinal cord.

4"-O-isovaleryltransferase gene (ist) was regulated by positive regulatory genes of midecamycin 4"-O-propionyltransferase gene (mpt) in Streptomyces lividans TK24. A BamH I ~8.0 kb fragment from Streptomyces mycarofaciens 1748 was proved that it contained mpt gene and linked with two positive regulatory genes, orf27 and orf28. Orf of mpt was replaced by orf of ist and linked with two regulatory genes or orf27 single, and individually cloned into the vectors pKC1139 or pWHM3 (high copy number), and then transformed into S. lividans TK24. The levels of mpt and ist expression were evaluated by the bio-tramsformation efficacy of spiramycin into 4"-O-acylspiramycins in these transformants. The results showed that 4"-O-isovalerylspiramycins could be detected only in the transformants containing the plasmids constructed with pWHM3. The efficacy of bio-transformation of the transformants containing two regulatory genes was higher than that of orf27 single. So, the positive regulatory genes system of mpt gene could enhance ist gene expression.
Acyltransferases ; genetics ; metabolism ; Bacterial Proteins ; genetics ; metabolism ; Gene Expression ; Genetic Vectors ; Plasmids ; Spiramycin ; analogs & derivatives ; biosynthesis ; Streptomyces ; enzymology ; genetics ; Streptomyces lividans ; metabolism ; Transformation, Genetic

Objective To describe the CT manifestations of thymic epithelial tumor and explore the correlation between CT findings and post-operative tumor-related survival time. Methods Ninety-one patients who underwent CT scan before operation were reviewed retrospectively. All cases had operation and were classified according to the WHO classification. The size, contour, shape, density and enhancement of the tumors on CT were assessed. Presence of mediastinal lymphadenopathy, great vessel invasion, metastasis to the lung or plural, myasthenia gravis (MG) were also analyzed. The survival rate was obtained using the Kaplan-Meier method. The Cox model was applied to determine the factors affecting the tumor-related survivals. Chi square test was used to analyze the relationship between CT findings and WHO classification. Results Two patients were excluded because of dying of myocardial infarction and colon cancer. The total 5-year survival rate was 84.3%(n=75). Eighty-nine patients had total 91 tumors. Tumors with diameter larger than 5 cm, lobular contour, heterogenous density, and presence of great vessel invasion, mediastinal lymphadenopathy, and metastasis were adverse factors which could significantly affect the survival time. Five-year survival rates of these factors were 72.7%, 77.3%, 76.7%, 73.8%, 30.0%, and 68.8%, respectively. Presence of MG was a favorable factor which also significantly affected the survival time (P＜0.05). While the shape and enhancement of the tumors and the age, gender of the patients did not significantly affect the survival time (P＞0.05). The result of the Cox multivariate analysis was consistent with that of the Log-rank test. For different WHO classification, there were significant different among the size or contour of the tumors, presence of great vessel invasion, mediastinal lymphadenopathy, and metastasis (x2 value were 6.598, 5.737, 18.307, 8.465, and 15.608, respectively P＜0.05). Conclusions CT findings may be served as predictors of clinical prognosis of the thymic epithelial tumors. Adverse factors for survival time are the size of the tumors and presence of mediastinal lymphadenopathy, while MG is a favorable factor for survival time.

Objective To investigate CT characteristics of ganglioneuroma.Methods CT findings in 12 patients with ganglioneuroma proved histopathologically were retrospectively analyzed.Results The lesions localized in the adrenal gland in 8,the retroperitoneum in 3,the posterior mediastinum in 1.eleven lesions appeared as homogeneous hypo-or isodense oval masses with well delineated margins and 1 was cysto-solid on plain CT scans.The calcifications were seen inside one tumor.On enhanced CT scans,the lesions were mild enhancement in 4,moderate enhancement in 3,significant enhancement in 3 and no enhancement in 2.Mild delayed enhancement in 5 cases,moderate delayed enhancement in 4 cases and no delayed enhancement in 3 cases were showed.Conclusion Typical ganglioneuroma shows low intensity,mild or moderate enhancement and delayed enhancement.

ObjectiveTo investigate the CT findings of thymic epithelial tumors (TETs).Methods The CT images of 133 cases with TETs confirmed pathologically were reviewed retrospectively.The TETs were reclassified according to WHO 2004 Classification System.The CT features of different histopathological types of TETs were analyzed.The frequencies of demonstrating these CT features were compared between different types using Chi-square exact test.ResultsType A(9/10,90.0％),AB(15/17,88.2％),B1 (10/13,76.9％ ),and B2( 31/46,67.4％ ) tumors were more likely to have spherical or oval shapes and smooth contours on CT.TETs with irregular or lobular contours were mostly seen in type B3 (21/30,70.0％ )and thymic carcinoma (15/17,88.2％ ).TETs with cyst and necrosis formation were common in type A(6/10,60％ ),B3 ( 19/30,63.3％ ) and thymic carcinoma ( 15/17,88.2％ ).Calcification was more frequently seen in type B2 and B3 (32/76,42.1％ ) than any other type ofTETs (8/57,14.0％ ;x2 =12.20,P ＜ 0.01 ).Type A,AB,B3 and thymic carcinoma had higher prevalence of significant enhancement (39/74,52.7％) than type B1 and B2 (8/57,13.6％;x2=22.01,P＜0.01).ConclusionAccording to WHO 2004 histologic classification system,different types of TET have corresponding CT features.CT has showed the potentiality in differentiating histological subtypes of TETs.

Aiming at the problems existing in standardized training of clinical resident physicians, we put forward a basic theory teaching method based on micro class,online PPT and network feedback test, covering the teaching contents and teaching methods, teaching evaluation etc. With systematic, concrete,organized and clear auxiliary clinical practice,we can achieve the purpose of training the residents who have comprehensive clinical practice ability.

Objective: To investigate the effect of pre-pregnancy weight and the increase of gestational weight on fetal growth restriction. Methods: From May 2013 to September 2014, a total of 3 474 pregnant women who took their first antenatal care and willing to undergo their prenatal care and delivery in Ma 'anshan Maternity and Child Care Centers were recruited in the cohort study. Excluding subjects without weight data before delivery (n=54), pregnancy termination (n=162), twins live births (n=39), without fetal birth weight data (n=7), 3 212 maternal-singleton pairs were enrolled for the final data analysis. Demographic information of pregnant woman, pregnancy history, disease history, height and weight were collected. In the 24^th-28^th, 32^nd-36^th gestational week and childbirth, three follow-up visits were undertaken to collect data of pregnancy weight, pregnancy vomiting, gestational hypertension, gestational diabetes mellitus, newborn gender and birth weight. χ² test was used to compare the detection rate of fetal growth restriction in different groups. Multivariate unconditional logistic regression model and spreadsheet were used to analyze the independent and interaction effect of pre-pregnancy weight and the increase of gestational weight on fetal growth restriction. Results: The incidence of fetal growth restriction was 9.7%(311/3 212). The incidence of fetal growth restriction in pre-pregnancy underweight group was 14.9% (90/603), higher than that in normal pre-pregnancy weight group (8.7% (194/2 226)) (χ²=24.37, P<0.001). The incidence of fetal growth restriction in inadequate increase of gestational weight group was 17.9% (50/279), higher than the appropriate increase of weight group (11.8% (110/932)) (χ²=36.89, P<0.001). Multivariate unconditional logistic regression analysis showed that compared with normal pre-pregnancy weight group, pre-pregnancy underweightwas a risk factor for fetal growth restriction, with RR (95%CI) at 1.76 (1.34-2.32); Compared with the appropriate increase of gestational weight group, inadequate weight increase during pregnancy was a risk factor for fetal growth restriction, with the RR (95%CI) at 1.70 (1.17-2.48). No additive model interaction [relative excess risk of interaction, attributable proportions of interaction, the synergy index and their 95%CI were 0.75 (-2.14-3.63), 0.21 (-0.43-0.86) and 1.43 (0.45-4.53), respectively] or multiplication model interaction (RR (95%CI): 1.00 (0.44-2.29)) existed between pre-pregnancy underweight and inadequate increase of gestational weight on fetal growth restriction. Conclusion Pre-pregnancy underweight and inadequate increase of gestational weight would increase the risk of fetal growth restriction without interaction.

Objective:To retrospectively analyze the independent risk factors of complicated appendicitis(CA)in children under five years old and establish a clinical prediction model, and to evaluate the clinical application of this model.Methods:A retrospective analysis was performed on children under five years old who underwent appendectomy at Children′s Hospital of Shanghai Jiao Tong University School of Medicine from January 2018 to December 2021.The children were divided into CA group and uncomplicated appendicitis group according to whether there was sign of perforation or gangrene in appendiceal tissue after operation.The differences in clinical features and preoperative laboratory test results between two groups were compared.The independent risk factors of CA were identified and a clinical prediction model was established.The clinical prediction model was verified by receiver operating characteristic curve.Results:A total of 140 children were enrolled in this study, including 84 cases in the CA group and 56 cases in uncomplicated appendicitis group.Univariate and binary Logistic regression analysis showed that the duration of symptoms>23.5 h( OR=6.650, 95% CI 2.469-17.912, P<0.05), abdominal muscle tension( OR=3.082, 95% CI 1.190-7.979, P<0.05) and C-reactive protein>41 mg/L ( OR=3.287, 95% CI 1.274-8.480, P<0.05) were independent risk factors for CA( P<0.05). The clinical prediction model of CA was constructed by the above mentioned three independent risk factors.The area under the receiver operating characteristic curve of the clinical prediction model was 0.881(95% CI 0.825-0.936), the sensitivity was 77.4%, the specificity was 87.5%, the positive predictive value was 91.3% and the negative predictive value was 70.0%. Conclusion:Acute appendicitis in children under five years old is more likely to progress to CA if the duration of symptoms>23.5 h, the level of C-reactive protein is increased, and the abdominal muscle tension is accompanied.The clinical prediction model of CA constructed by common clinical information in pediatric clinics has good prediction efficiency, which provides a simple and feasible reference method for clinicians to distinguish CA from uncomplicated appendicitis.