Molecular characterization of embB306 gene in Mycobacterium tuberculosis isolates from tuberculosis patients in Chongqing municipality / 中华预防医学杂志

<p><b>OBJECTIVE</b>To understand the characteristics of embB gene mutation of Mycobacterium tuberculosis (MTB) isolates from tuberculosis patients in Chongqing, and the value of embB306 as a molecular marker used to diagnose ethambutol (EMB)-resistant MTB strains.</p><p><b>METHODS</b>Direct sequencing was used to analyze the polymorphism of embB mutation in 51 EMB-resistant MTB strains and 50 EMB-sensitive MTB strains. And diagnostic testing was used to evaluate the value of embB306 as a molecular marker of EMB -resistant MTB strains as compared with the traditional sensitivity test.</p><p><b>RESULTS</b>All 34 of 51 EMB-resistant strains (66.7%) and 3 of 51 EMB-sensitive strains (6%) had had embB306 mutation. The embB306 mutation rate in EMB-resistant strains coming from previously treated case was 87.5%, showing significantly higher than that from new cases (48.1%, P < 0.01); embB306 mutation rate was increased with the number of the resistant drugs; embB306 mutation serving as a marker to diagnose EMB-resistant MTB strains comparing with the traditional sensitivity test, had the rate of sensitivity = 66.7%, specificity = 94.0%, accuracy = 80.2% and Youden index = 60.7%.</p><p><b>CONCLUSION</b>embB306 mutation should be the main mechanism of MTB resistance to EMB in Chongqing, showing an association with the history of the treated and numbers of the resistant drugs. embB306 mutation should be a good marker to diagnose EMB-resistant MTB strains.</p>

Change of free hemoglobin content after mixing type B whole blood with different amounts of type O whole blood / 中国实验血液学杂志

To investigate the changes of free hemoglobin (FHb) content after mixing type B whole blood with different amounts of type O whole blood at room temperature and at 37 degrees C, two lots of type B whole blood stored at 4 degrees C for 24 hours were randomly taken as recipient blood, and were packed as 60 ml respectively. Type O blood was taken as donor blood. 60 ml type B whole bloods were mixed with different amounts of type O whole blood, i.e. with 9, 12, 15 and 18 ml. The mixed blood was packed into 100 ml plastic blood bags and stored at 37 degrees C or room temperature, shaken once every 15 minutes. Free hemoglobin content was determined for the harvested samples at 1, 2, 4, 8 and 12 hours after store. The results showed that there was no significant elevation of FHb within 12 hours after mixing B whole blood with different amounts of type O whole blood. In another lot, there was obvious difference in FHb after 1 hour store along with the prolongation of store at either room temperature or 37 degrees C. In one lot, there was no difference of FHb (P > 0.05) during 1 - 8 hours of store at room temperature or 37 degrees C, but significant difference at 12 hours of store (P < 0.001). In another lot, there was no difference of FHb (P > 0.05) within 1 hour of store at room temperature and at 37 degrees C, but significant difference during 2 approximately 8 hours of store (P < 0.001). It is concluded that the FHb would not change significantly within 12 hours after type B blood was mixed with 1 200 ml of type O whole blood, but when the mixed blood was placed at room temperature or at 37 degrees C for 8 hours, the FHb content approaches, even exceeds 170.4 mg/L which was observed in the blood stored for 2 days. It suggests that freshly collected blood must be put into refrigerator of 2 approximately 4 degrees C for storing as soon as possible, so as to decrease the catabolism of erythrocyte and the releasing of FHb and other metabolites which are deleterious to the recipients.

Experimental hemorheology study on group a whole blood added with group O whole blood / 中国实验血液学杂志

The study was to investigate the hemorheologyic changes of group A blood recipient transfused with large amounts of group O whole blood, by erythrocyte count, sympexis index, erythrocyte deformation index, erythrocyte rigid index and whole blood reduced viscosity, 60 ml of group A whole blood were added with 9, 12, 15 and 18 ml of group O whole blood (which corresponds to the 4 000 ml whole blood added with 600, 800, 1 000 and 1 200 ml whole blood). The mixed blood was incubated at 37 degrees C with mixing at 80 times per minute. Samples were taken from the mixed blood at 30 minutes, 2, 4, 8, 12 and 24 hours after culture, and the hemorheology of the mixed whole blood was determined by FASCO-series type 3020B automatic rheograph apparatus. The results showed that there were no differences of erythrocyte count, sympexis index, erythrocyte deformation index, erythrocyte rigid index and whole blood reduced viscosity among all different kinds of mixed whole blood, and there was no difference of sympexis index at different times, but there were obvious differences of erythrocyte count, erythrocyte deformation index, erythrocyte rigid index and whole blood reduced viscosity. It is concluded that blood transfusion of 1,200 ml group O whole blood to a recipient with 50 kg of body weight but with different blood type in emergent situation may exert no harm to the erythrocytes of recipient in a short term.