Construction of nsdAmgh gene disruption mutant in Strempomyces roseoflavus Men-myco-93-63 / 生物工程学报

Insertional mutagenesis is a widely used method to determine the function(s) of a gene. To study the function(s) of the gene nsdAmgh in Streptomyces roseoflavus, a homologous recombination vector pSRNA2500 was structured in this paper. The recombination donor vector was then transformed into Strempomyces roseoflavus strain Men-myco-93-63 by conjugative transfer. The transformants were subjected to selection under the pressure of high temperature and appropriate antibiotics. As a result, several disrupted mutants of nsdAmgh gene, with a phenotype of Am(s)Km(r), were isolated and verified using PCR and Dot-blotting and Southern blotting hybridization methods. Functional analysis showed that the disrupted mutants of nsdAmgh had a two-fold higher inhibition against Verticillium dahlia Kleb than that of the wild strain Men-myco-93-63, which all will provide a new study route for future research about positive and negative regulator in Men-myco-93-63.

Study on a test of screening to predict stroke-using cerebral vascular hemodynamic indexes / 中华流行病学杂志

<p><b>OBJECTIVE</b>To evaluate efficacy and optimal cut-off-point through cerebral vascular hemodynamic indexes (CVHI) examination to predict stroke.</p><p><b>METHODS</b>A number of 20,333 people at 35 years old and over were checked by CVHI and accumulative score was calculated according to the value of detected indexes. Risk factors of stroke were investigated simultaneously. One hundred and sixty-eight patients with stroke occurred during 4-year following up. Typical syndromes and signs stroke were used as golden standard to evaluate screening efficacy of CVHI.</p><p><b>RESULTS</b>Score of optimal cut-off-point of cerebral vascular hemodynamic indexes was under 75 in ROC curve analyses. Sensitivity, specificity, accuracy, positive and negative predictive values, positive and negative likelihood ratios as well as Youden's index for predicting stroke within 4 years after examination were found to be 87.50%, 67.70%, 67.86%, 2.21%, 99.85%, 2.71, 0.18 and 0.55 respectively. Sensitivity and positive predict values for predicting cerebral vascular thrombosis were superior to predicting cerebral hemorrhage. Positive predicting value in risk exposure population was higher than that of overall population. Coefficiency of variation of cerebral vascular hemodynamic examination was 4.03%. The agreement rate of examination between two physicians was 97.62% and Kappa value was 0.94.</p><p><b>CONCLUSION</b>The score of optimal cut-off-point of cerebral vascular hemodynamic indexes examination was 75. Both Efficacy and reliability for predicting stroke seemed to be good, especially for predicting cerebral vascular thrombosis.</p>

Evaluation on effectiveness of stroke intervention in over 35 years old population in Nanhui county of Shanghai city / 临床神经病学杂志

Objective To evaluate the effectiveness of "screen and target population intervention policy" for stroke intervention in Nanhui county of Shanghai city.Methods A cross sectional survey on stroke was carried out in January 1999,and 696558 population in Nanhui county of Shanghai city were investigated in the study. Surveillance data on incidence and mortality rate of stoke from January 1996 to December 1998 in the county were retrospectively checked and reinvestigated.The CVHI of 35 years old and over in this population which have one and more of risk factors were measured,their CVHI total score