MULTIDRUG RESISTANT TUBERCULOSIS – BIOMECHANISM,EPIDEMIOLOGY AND MANAGEMENT STRATEGIES

Muitidrug resistant tuberculosis has shown an alarming increase and this assumes added importance in view of the increasing number of HIV infected patients. This article reviews the biomechanism of resistance and discusses the present stategies that are available and recommended to tackle the rising incidence of tuberculosis due to resistant mycobacteria.KEYWORDS: Antitubereular drugs, Drug resistance, Mycobacterium tuberculosis     

Preterm premature rupture of membranes (PPROM): outcomes of delivery at 32°/7 –336/7 weeks after confirmed fetal lung maturity (FLM) versus expectant management until 34°/7 weeks

Objective: Our objective was to compare maternal and neonatal outcomes in patients with preterm premature rupture of membranes (PPROM) delivered prior to 34^°/7 weeks upon confirmation of fetal lung maturity (FLM) to those managed expectantly until 34^°/7 weeks.

Methods: We performed a retrospective cohort study of non-anomalous singleton gestations with PPROM occurring after 24 weeks delivered between 32^°/7 and 34^°/7 weeks from 2004 to 2012. Patients delivered upon documented FLM (+FLM) – defined as the presence of phosphatidylglycerol (PG) at 32^°/7–33^6/7 weeks if amniotic fluid was obtainable vaginally – were compared with patients delivered without documented FLM between 32^°/7 and 34^°/7 weeks (expectant). Primary outcomes included maternal infection (clinically diagnosed endometritis or chorioamnionitis), placental abruption and a composite of neonatal morbidities (including but not limited to mechanical ventilation, intraventricular hemorrhage, necrotizing enterocolitis, sepsis and respiratory distress syndrome). Statistical analysis was performed using Student’s t-test for continuous variables and Chi-square or Fisher’s exact test for categorical data. Covariates were analyzed via multivariate logistic regression and adjusted odds ratios were calculated.

Results: Of 237 PPROMs delivered at 32^°/7–34^°/7 weeks, 74 were intentionally delivered for +FLM and 163 were expectantly managed. No cord prolapse or stillbirth was observed. Maternal infection (chorioamnionitis or endometritis) was lower in the +FLM group (aOR 0.33 95% CI 0.12–0.88). Overall, there was no difference in composite neonatal morbidity did not differ between the two groups (aOR 1.36 95% CI 0.53–3.54).

Conclusions: In patients with PPROM, delivery after confirmation of FLM at 32^°/7–33^6/7 weeks compared with expectant management until 34^°/7 weeks may prevent maternal infection without increasing neonatal morbidity.     

HPLC柱切换法血浆直接进样测定糖肾平

采用HPLC柱切换技术,以Merck Lichroprep RP2(25～40μm)为预处理柱填料,以水为预处理流动相,以0.2mol/L乙酸-乙酸铵为净化清洗液,血浆直接进样,在线富集净化样品。血浆样品以0.2ml/min慢速转移通过预处理柱,净化回收率达80%。以ShimpackCLC-ODS为分析柱(15cm×6mm,ID),甲醇-异丙醇-0.2mol/L 乙酸铵(61:5:34)为分析流动相,310nm波长检测,外标法定量测定人体血浆中糖肾平的浓度。血浆样品仅需稀释后即可进样,净化富集样品操作简便,预处理柱可长期反复进样使用。血浆中最低检测浓度为30ng/ml,日内变异系数为2.0%～5.4%,日间变异系数为2.4%～2.7%,在浓度为60～2020ng/ml血浆范围内呈线性关系。     

Maternal serum folate and zinc concentrations and their relationships to pregnancy outcome.

To evaluate the relationship between folate and zinc, and its effect on pregnancy outcome, maternal serum folate and zinc concentrations were determined at 18 and 30 wk gestation in a defined population of 285 pregnant women as part of a large-scale study to identify risk factors for fetal growth retardation (FGR). These results were correlated with birth weight and Apgar scores of newborn infants and with maternal infections during the perinatal period. A weak linear relationship was observed between maternal serum folate and zinc concentrations at 30 wk gestation. Folic acid supplementation had favorable effects on birth weight and Apgar scores of newborns, and reduced prevalence of FGR and maternal infections. No significant correlation was found between serum zinc concentration and birth weight of infants. The concept that folic acid supplementation has an adverse effect on maternal zinc nutriture and pregnancy outcome was not supported.     

The impact of short interpregnancy intervals on pregnancy outcomes in a low-income population.

OBJECTIVES: The objective of this study was to determine whether the length of the interval between pregnancies was associated with either preterm birth or intrauterine growth retardation in a low-income, largely Black population. METHODS: The study population consisted of 4400 women who had received prenatal care in county clinics and had two consecutive singleton births between 1980 and 1990. RESULTS: Interpregnancy intervals were positively associated with age and negatively associated with the trimester in which care was initiated in the second pregnancy. Whites had shorter intervals than non-Whites. The percentage of preterm births increased as the length of the interpregnancy interval decreased, but only for women who had not had a previous preterm birth. The association between interval and preterm birth was maintained when other factors associated with preterm birth were controlled. There was no significant relationship between intrauterine growth retardation and interpregnancy interval. CONCLUSIONS: Women, particularly those who are poor and young, should be advised of the potential harm to their infants of short interpregnancy intervals.     

Carcinogenic polycyclic aromatic hydrocarbons increase intracellular Ca2+ and cell proliferation in primary human mammary epithelial cells

Previous studies have shown that polycyclic aromatic hydrocarbons (PAHs) mobilize intracellular Ca2+ in human T cells by inositol trisphosphate-dependent mechanisms resulting from activation of phospholipase C-gamma by SRC-related protein tyrosine kinases, thereby mimicking antigen-receptor activation. Ca2+ appears to play an important second messenger role in growth factor control of cell proliferation in human mammary epithelial cells (HMEC), such as the epidermal growth factor receptor pathway. The purpose of the present studies was to determine if PAHs are able to increase intracellular Ca2+ in primary cultures of HMEC and increase cell proliferation. Two carcinogenic and two non-carcinogenic PAHs were tested for their ability to increase intracellular Ca2+ in HMEC. The carcinogenic PAHs dimethylbenz[a]anthracene (DMBA) and benzo[a] pyrene (BaP) were able to cause Ca2+ elevation in HMEC at early time points (2 h) and caused sustained alterations in Ca2+ homeostasis (18 h). DMBA showed maximal effects at early time points (2 h), while BaP showed maximal effects on sustained Ca2+ (18 h). 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD), a potent dioxin and tumor promoter, produced maximal Ca2+ elevation at 2 h, with a return to near baseline levels by 6 h. The non-carcinogenic PAHs benzo[e]pyrene and anthracene did not significantly alter intracellular Ca2+ at any time point. alpha-Naphthoflavone significantly reduced the Ca2+ response induced by BaP treatment, but not by DMBA or TCDD, suggesting that P450 1A or 1B metabolism of BaP may be important in the sustained Ca2+ elevating response. In evaluating the effects of BaP on HMEC proliferation, BaP was found to increase the number of cells recovered after 4 days in culture in the absence or presence of various concentrations of epidermal growth factor. These studies provide initial evidence that Ca2+ signaling may be associated with mitogenesis in HMEC, which may play a role in tumor promotion and progression produced by PAHs.      

交流示波极谱滴定法测定盐酸环丙沙星及其制剂的含量

目的：采用交流示波极谱滴定法测定了盐酸环丙沙星及其制剂的含量。方法：在ｐＨ５．０－５．５的醋酸－醋酸钠缓冲液溶液中，环丙沙星与四苯硼钠定量反应形成１：１沉淀。过量的四苯硼钠用醋酸亚铊标准溶液回滴至示波极谱图上四苯硼钠切口消失。结果：该法平均回收率为９９．１８％，ＲＳＤ为０．４９％。结论：本法简便，快速，结果准确，可靠。     

睾丸酮、雌二醇和棉酚合并用药的雄性抗生育作用及其安全性的研究

睾丸酮、雌二醇和棉酚合并用药的雄性抗生育作用及其安全性的研究叶惟三，但凌，郭燕，钱晓菁，应骏，薛社普（中国医学科学院，中国协和医科大学基础医学研究所，北京１００００５）减轻有抗男性生育活性棉酚的副作用是发展棉酚成为男性避孕药急待解决的问题［１，２］。...     

抗癌及癌化学预防药物的研究:3-α-酮醛香豆素衍生物的合成及其抗致突活性与结构间的关系

α-酮醛及其衍生物在抗病毒、抗肿瘤方面有一定活性。我们合成了18个新的3-α-酮醛香豆素衍生物,研究该类化合物的质谱裂解方式与氢核磁共振谱的特征峰。体外药理筛选发现其中部分化合物有不同程度的抗致突活性,对其构效关系进行了分析,并提出了这类化合物产生抗致突活性的可能亚结构。