ABSTRACT
Objective To explore the application values of GeneXpert MTB/RIF assay (Xpert assay) for rifampicin resistance and multidrug resistant tuberculosis (MDR-TB).Discordance of Xpert and L-J proportion DST of rifampicin was analyzed.Methods Specimens of 1 300patients from January 2014to June 2016in our hospital were collected for solid culture, Xpert assay and L-J proportion drug susceptibility test (DST).Rifampicin resistance detected by Xpert assay was compared with L-J proportion method as a gold standard.Sequencing of rpoB gene and determination of minimum inhibition concentration were accomplished on the discordant MTB strains between Xpert and L-J proportion DST.Results Compared with the DST, the sensitivity, specificity, positive and negative predictive value of Xpert assay for rifampicin resistance were 99.31％, 97.82％, 92.88％and 99.80％, respectively.Among 1 300culture-positive specimens, mutations were detected from 309specimens by Xpert assay, which included 125initial treatment and 184retreatment patients.Among309specimens with rpoB gene mutations, mutations detected by probes E, D and B were common, and the rates were 65.70％, 14.56％and 10.68％, respectively.Totally 239patients were MDR-TB[77.35％ (239/309) ], of which 94initial treatment patients[75.20％ (94/125) ]and 145retreatment patients[78.80％ (145/184) ]were MDR-TB.Among 22strains which were detected rpoB gene mutations by Xpert, but sensitive by L-J proportion DST, 6strains had no mutation in rpoB gene rifampicin resistance determining region (RRDR);16strains had mutations, which were mainly located in L511Pcodon (8strains) and L533Pcodon (4strains).Among 2strains which had no rpoB gene mutation by Xpert, but were resistant by L-J proportion DST, 1strain had no mutation in rpoB gene RRDR region;1strain had mutation which was located in E546G codon outside RRDR region.Conclusion Xpert assay can be used to rapidly detect rifampicin resistance and to screen MDR-TB.Mutations in codon 511and 533are related to low-level resistance to rifampicin.
ABSTRACT
Objective To investigate the role of N-acetylcysteine as a protective agent in rifampicin-induced hepatic injury of mice. Methods Thirth-two Kunming mice were randomly divided into four groups(n=8 each).The mice in each group were injected intraperitoneally with 0.9% sodium chloride solution (control), N-acetylcysteine (NAC), combination of rifampicin (R), or NAC and R (NAC+R) once every day.After 14 days, the liver index (LI), alanine aminotransferase (ALT) and aspartate aminotransferase ( AST) activity in serum, and the level of malondialdehyde( MDA) ,superoxide dismutase( SOD) activity in liver tissues were measured respectively.Hepatic tissue morphology was observed under light microscope. Results Macroscopic analysis revealed that rifampicin led to severe liver tissue injury,including a wide range of hepatocellular vascular congestion,fatty change and local necrosis, whereas the administrationof NAC produced a significant reduction of rifampicin-induced hepatotoxicity .LI,ALT and AST activities in R or NAC+R group were significantly elevated as compared with the control group(P<0.01) .LI, activities of ALT and AST in serum,and MDA levels in liver tissues in NAC+R group were significantly lower than those in R group ( P<0.01) ,but the SOD activity in NAC+R group was increased significantly in comparison with R group (P<0.01). Conclusion Rifampicin was able to cause severe hepatic injury.Pre-administration of NAC reduced the side-effect induced by the treatment with the rifampicin.
ABSTRACT
Objective To discuss the Clinical character of pulmonary tuberculosis combined malignant lymphoma and its Pathogenesis,and to review the literature.Methods Eighteen cases of pulmonary tuberculosis combined malignant lymphoma from 1996 to 2003 were retrospectively analyzed by its clinical manifestations,X-ray features,diagnosis and treatments.Results 18 cases were all infiltrative pulmonary tuberculosis,13 them were calcification focals,5 were active pulmonary tuberculosis;5 of all were Hodgkin’s lymphomas,13 of all were non-Hodgkin′s lymphomas.16 cases were lymphomas after tuberculosis,2 cases tuberculosis after lymphomas,none were co-existent malignant lymphoma and tuberculosis.Tuberculosis may precede or complicate a lymphomatous process during the development of both diseases,This might is linked to immune deficiency and chronic inflammation;Lymphomas might cause pulmonary tuberculosis,it might cause the immune turbulence of an individual,Pulmonary tuberculosis infection occurring during or after the radiotherapy and chemotherapy of lymphoma.Conclusions It may pulmonary tuberculosis combined malignant lymphoma in the patients in the endemic areas of tuberculosis,Appropriate invasive biopsy procedures are necessary for early diagnosis.