Meta-analysis of infection and disease among household contacts of patients with drug-resistant tuberculosis / 中国热带医学

@#Abstract: Objective　To analyze the association between drug resistance and the risk of latent tuberculosis infection and disease among household contacts of patients with pulmonary tuberculosis, and to explore whether the compensatory mutation of drug-resistant Mycobacterium tuberculosis will enhance its pathogenicity or transmission ability. Methods　The English and Chinese databases, including PubMed, web of science, EMBASE, Cochrane library database, CNKI and Wanfang database, were searched by computer from the time of establishment of the database to January 2022. Cohort studies on the risk of infection and disease among household contacts of patients with drug-resistant and sensitive pulmonary tuberculosis were searched and screened according to the inclusion and exclusion criteria. The data were extracted and evaluated by NOS scale, using stata16.0 software meta-analysis to calculate the combined effect of tuberculosis infection and disease risk of family contacts, and carry out heterogeneity test, subgroup analysis and sensitivity analysis. Results　A total of 7 cohort studies involving 9653 TB index cases and 29, 734 house contacts were included. The results of meta-analysis showed that compared with drug-sensitive pulmonary tuberculosis patients, the risk of tuberculosis infection in house contacts of drug-resistant pulmonary tuberculosis patients was increased (OR=1.56, 95%CI=1.25-1.96, P<0.001), but there was no difference in the risk of incidence (RR=1.06, 95%CI=0.80-1.41, P=0.67>0.05). Subgroup analysis showed that the risk of latent tuberculosis infection in house contacts was affected by the study area, and the size of family contacts had an impact on the risk of TB . Sensitivity analysis showed that the results of meta-analysis were robust. Conclusion　Compared with drug sensitive TB patients, household contacts with drug-resistant TB patients had a higher risk of tuberculosis, but there was no difference in the risk of TB among the two groups.

[Effects of mono(2-ethylhexyl) phthalate on testosterone biosynthesis in leydig cells cultured from the rat testis].

OBJECTIVE: To investigate the effects of mono(2-ethylhexyl) phthalate(MEHP), the primary metabolite of di(2-ethylhexyl) phthalate (DEHP), on testosterone biosynthesis in Leydig cells cultured from the Sprague Dawley rat testis. METHODS: Based on the primary Leydig cell culture model, MEHP exposure groups involved control (0 micromol/L), 62.5, 125, 250, 500 and 1000 micromol/L. We observed mitochondria activity with the MTT method, measured the testosterone level with RIA and determined steroidogenesis acute regulatory protein (StAR) mRNA expression with RT-PCR. RESULTS: After Leydig cells were exposed to MEHP for 24 hours, the activity of mitochondria enhanced evidently at 250 micromol/L and then declined markedly at 1000 micromol/L compared with the control group (P < 0.01). The testosterone level showed an increasing tendency in both basal and hCG-stimulated states with statistical significance at 250 and 500 micromol/L compared with the control group (P < 0.01). However, the expression of StAR mRNA appeared unchanged at 62.5, 125 or 250 micromol/L, but exhibited a decreasing tendency at 500 and 1000 micromol/L (P < 0.01). CONCLUSION: ME- HP directly affected the activity of mitochondria and testosterone biosynthesis of the Leydig cells in vitro. StAR, the regulator of cholesterol transport into mitochondria, might not be responsible for the increase of testosterone biosynthesis induced by MEHP.

[Effects of dibutyl phthalate on sertoli cells of rat testis].

OBJECTIVE: The present study was performed to examine functional and structural impairment of rat sertoli cells following dibutyl phthalate (DBP) exposure. METHODS: The 6-week-old healthy male Sprague Dawley rats were randomly divided into 4 groups with 16 animals in each group. DBP dissolved in peanut oil was administered by gavage at doses of 0, 250, 500 and 1 000 mg/kg. After 2-week DBP treatment, half of the rats were sacrificed. The rest were killed following 4-week DBP exposure. Follicle stimulating hormone (FSH) was analysed by radioimmunoassay. The relative expression levels of androgen binding protein (ABP) mRNA and inhibin (INH)alpha mRNA were determined by semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR). The sertoli cell ultrastructures were observed by using transmission electron microscope (TEM). RESULTS: FSH levels were increased after 4-week DBP exposure with significance at doses of 250 and 1 000 mg/kg. Sperm head count and daily sperm product were decreased significantly in 500 and 1 000 mg/kg groups. The expression levels of ABP mRNA were 0.89 +/- 0.15, 0.85 +/- 0.23, 0.54 +/- 0.17, 0.52 +/- 0.16 and 0.88 +/- 0.16, 0.61 +/- 0.12, 0.48 +/- 0.15, 0.47 +/- 0.11 for 0, 250, 500 and 1 000 mg/kg after 2- and 4-week DBP treatments respectively with significance at doses of 500 and 1 000 mg/kg (P < 0.01), while the levels of INHalpha mRNA were 0.88 +/- 0.16, 0.61 +/- 0.12, 0.48 +/- 0.15, 0.47 +/- 0.11 and 0.75 +/- 0.19, 0.56 +/- 0.16, 0.53 +/- 0.08, 0.45 +/- 0.10 with significance at all exposure groups (P < 0.01 or P < 0.05). In sertoli cells of rats exposed to 1 000 mg/kg DBP, TEM photos showed more lysosomes in cytoplasm, proliferated and expanded endoplasmic reticulum and nuclei malformation. CONCLUSIONS: Sertoli cell should be one of the major toxic targets. Impairment of spermatogenesis caused by DBP should be partly due to the suppression of ABP and INHalpha biosynthesis.