UPLC-MS/MS测定人痰液中异烟肼、吡嗪酰胺和左氧氟沙星的浓度

目的建立超高效液相色谱串联质谱法(UPLC-MS/MS)同时检测痰液中3种药物异烟肼(isoniazid,INH)、左氧氟沙星(levofloxacin,LFX)和吡嗪酰胺(pyrazinamide,PZA)浓度的方法,冒在为实现临床个体化用药提供帮助。方法痰液样品离心后经甲醇/乙腈蛋白沉淀法预处理后进样液质联用仪进行分析。实验采用的流动相A为含0.1%甲酸的水溶液,流动相B为含0.1%甲酸的乙腈;流速0.35mL·min^-1;采用ACQUITY UPLAC HSS T31.8μm column(2.1mm×100mm,Waters公司)分离;采用电喷零电离源,采用多反应监测(multiple reaction monitoring,MRM)模式对待测物进行正离子扫描检测。此外,本试验盲态收集5例患者的痰液,用该法进行定量分析。结果测得痰液中INH、PZA和LFX分别在48~6000 ng·mL^-1(r=0.9988)、480~60000 ng·mL^-1(r=0.9993)、120~15000 ng·mL^-1(r=0.9995)内表现出良好的线性关系。INH、PZA和LFX 3种药物的日内和日间精密度均低于15%,且3种药物的提取回收率均处于97.21%~107.80%之间。7例受试者体内均检测到药物INH,质量浓度分别为44.74、120.1、301.5、481、595.5、1220及1570 ng·mL^-1;PZA的质量浓度分别为104.2、6273.34和3185 ng·mL^-1;1例受试者检出LFX,质量浓度为199.86 ng·mL^-1。结论本试验建立了痰液中INH、PZA及LFX的检测方法,具有灵敏度高、测定结果准确、快速等诸多优点,可以应用于临床治疗药物的监测。     

Genotype MTBDR plus快速检测耐多药结核病的临床应用

目的评价Genotype MTBDR plus快速检测耐多药结核病的临床应用价值。方法对涂阳肺结核患者痰标本和临床分离菌株分别用传统比例法药敏试验和Genotype MTBDR plus进行异烟肼和利福平耐药性检测,以比例法药敏试验为金标准对Genotype MTBDR plus检测结果进行比较分析。结果在368例涂阳痰标本中,比例法药敏试验与Genotype MTBDR plus检测异烟肼、利福平耐药率比较,差异均无统计学意义(P均0.05);两种方法检测异烟肼和利福平的一致率分别为95.38%(351/368)和97.55%(359/368)。在85例临床分离菌株中,比例法药敏试验与Genotype MTB-DR plus检测异烟肼、利福平耐药率比较,差异均无统计学意义(P均0.05)。两种方法检测异烟肼和利福平一致率分别为92.94%(79/85)和96.47%(82/85)。与比例法药敏试验比较,Genotype MTBDR plus检测涂阳痰标本和菌株中异烟肼的灵敏度分别为76.32%(29/38)、78.57%(11/14),特异性分别为97.58%(322/330)、95.77%(68/71));检测利福平的灵敏度分别为93.55%(29/31)、91.67%(11/12),特异性分别为97.92%(330/337)、97.26%(71/73)。结论 Genotype MTBDRplus能快速检测结核分枝杆菌对异烟肼、利福平的耐药性,和传统药敏试验比较具有较高的一致性和特异性,是目前快速诊断耐多药结核病的一种较为理想的检测方法,适宜在有条件的实验室开展。     

Incorporation of Antitubercular Drug Isoniazid in Pharmaceutically Accepted Microemulsion: Effect on Microstructure and Physical Parameters

Purpose The purpose of present study is to formulate microemulsion composed of oleic acid, phosphate buffer, Tween 80, ethanol and to investigate its potential as drug delivery system for an antitubercular drug isoniazid. Materials and Methods The pseudo-ternary phase diagram (Gibbs Triangle) was delineated at constant surfactant/co-surfactant ratio (Km 0.55). Changes in the microstructure were established using conductivity (σ), viscosity (η), surface tension (γ) and density measurements. Dissolution studies and particle size analysis were carried out to understand the release of isoniazid from the microemulsion formulation. Further, partitioning studies and spectroscopic analysis (FT-IR and ¹H NMR) was performed to evaluate the location of drug in the colloidal formulation. Results Physico-chemical analysis of microemulsion system showed the occurrence of structural changes from water-in-oil to oil-in-water microemulsion. It has been observed that the microemulsion remained stable after the incorporation of isoniazid (in terms of optical texture, pH and phase separation). The changes in the microstructure of the microemulsion after incorporation of drug was analyzed on the basis of partition studies of isoniazid in microemulsion components and various parameters viz pH, σ, η,γ. In addition, the particle size analysis indicates that the microemulsion changes into o/w emulsion at infinite dilution. The spectroscopic studies revealed that most of the drug molecules are present in the continuum region of an o/w microemulsion. Dissolution studies infer that a controlled release of drug is expected from o/w emulsion droplet. In the present system the release of isoniazid from microemulsion was found to be non-Fickian. Conclusion The present Tween based microemulsion appears beneficial for the delivery of the isoniazid in terms of easy preparation, stability, low cost, sustained and controlled release of a highly water soluble drug. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Rifampicin exacerbates isoniazid-induced toxicity in human but not in rat hepatocytes in tissue-like cultures

BACKGROUND AND PURPOSE: Rifampicin has been extensively reported to exacerbate the hepatotoxicity of isoniazid in patients with tuberculosis. However, this was controversially claimed by previous reports using rat models. This study evaluated the effect of rifampicin on isoniazid-induced hepatocyte toxicity by using human and rat hepatocytes in tissue-like culture.EXPERIMENTAL APPROACH: Hepatocytes in tissue-like gel entrapment were used to examine isoniazid toxicity, as shown by cell viability, intracellular glutathione content and albumin secretion. For demonstration of the differential effects of rifampicin on human and rat hepatocytes, induction by rifampicin of cytochrome P450 (CYP) 2E1, a major enzyme associated with isoniazid hepatotoxicity, was detected by 4-nitrocatechol formation and RT-PCR analysis.KEY RESULTS: Rifampicin (12 microM) enhanced isoniazid-induced toxicity in human hepatocytes but not in rat hepatocytes. Enhanced CYP 2E1 enzymic activity and mRNA expression were similarly detected in human hepatocytes but not in rat hepatocytes. Both rat and human hepatocytes in gel entrapment were more sensitive to isoniazid treatment compared with the corresponding hepatocytes in a monolayer culture.CONCLUSIONS AND IMPLICATIONS: The difference in induction of CYP 2E1 by rifampicin between rat and human hepatocytes accounted for the difference in exacerbation of isoniazid hepatocyte toxicity by rifampicin, with more significant toxicity in gel entrapment than in monolayer cultures. Thus, human hepatocytes in tissue-like cultures (gel entrapment) could be an effective model for hepatotoxicity research in vitro, closer to the in vivo situation.     

Isoniazid causing pleural effusion

Isoniazid (INH) is a first-line antitubercular drug. We report a case of a patient who developed a pleural effusion 2 months after starting antitubercular treatment for spinal tuberculosis. Isoniazid was found to be the culprit and its discontinuation caused subsidence of the effusion.     

An observational study on the incidence of tuberculosis among a cohort of HIV infected adults in a setting with low prevalence of tuberculosis

Background: Tuberculosis (TB) remains a main cause of morbidity and mortality among individuals infected with HIV. We investigated the incidence of TB among a cohort of HIV infected patients attending a setting with low TB burden where screening for latent TB infection is not routinely carried out.

Methods: an observational cohort study on HIV-infected adults attending the HIV clinic at Queen Elizabeth Hospital Birmingham, UK between 1 January 2011 and 30 September 2015. Patients with culture-proven TB after HIV diagnosis, or those treated for clinical diagnosis of the infection, were classified as having “active TB”.

Results: 1824 patients were included in the study (5347 patient years of follow up), of whom 21 patients developed TB (16 microbiology confirmed). Of the 666 new HIV diagnoses, six patients developed TB within one month, giving a TB prevalence at the time of HIV diagnosis of 0.9%. The total TB incidence for the remaining 1818 patients was 2.81 cases per 1000 patient years (95% CI: 1.63–4.53). TB incidence was significantly more common among patients with CD4 ≤ 200 cells/mm³ compared to those with CD4 > 500 cells/mm³ (28.2 vs. 1.22 per 1000 patient years, p < 0.001), and in patients with VL ≥ 40 copies/mL compared to <40 copies/mL (8.30 vs. 1.42, p < 0.001).

Conclusion: In settings with low TB prevalence, early start of combined antiretroviral therapy and intensified TB case finding protocols may significantly reduce the incidence of TB.     

结核病患者异烟肼治疗依从性现场检测方法的建立与验证

目的建立尿中异烟肼代谢产物现场快速定性检测方法,评估结核病患者治疗依从性。方法建立氰化物-氯胺T-巴比妥酸定性检测异烟酸法,通过北海市结核病防治院住院53例服用异烟肼的在治患者和51例未服药病人尿液检测对方法进行验证。结果所建立方法的检测原理:氰化物溶液与氯胺T溶液混合,再与待检物、巴比妥酸溶液混合,在室温下产生显色反应,目视判读结果,蓝紫色为阳性,异烟酸检出限约为0.5μg/m L。在104名临床住院患者的验证试验中,53例服用异烟肼的结核病患者服药后6h、24h尿液检测结果全部阳性,灵敏度100.0%;51例未服药对照组尿检结果全部阴性,特异度100.0%。结论建立了尿异烟肼代谢产物现场快速定性检测方法,经临床验证该方法的灵敏度、特异度均可达100.0%。     

银杏叶醇提取物对异烟肼和利福平肝毒性保护作用的实验研究

目的 :观察银杏叶醇提取物对异烟肼和利福平肝毒性的保护作用及其机制探讨。方法 :分别测定肝损害组和银杏叶醇提取物大、小剂量组小鼠的血清谷丙转胺酶 (SGPT)、肝指数、肝匀浆丙二醛 (MDA)含量、肝微粒体P4 50和线粒体Ca2 ATP酶活性 ,以及肝病理检查 ,并与对照组比较。结果 :银杏叶醇提取物大、小剂量均可对抗异烟肼和利福平引起的MDA、SGPT、肝微粒体P4 50 的增高 (P <0 .0 5) ,以及对抗其引起的形态学改变 ;银杏叶醇提取物大剂量对抗其线粒体Ca2 ATP酶活性的降低。结论 :银杏叶醇提取物可对抗异烟肼和利福平所致肝毒性。     

Latent tuberculosis infection: Opportunities and challenges

Diagnosing and treating latent tuberculosis (TB) infection (LTBI) is recognized by the World Health Organization as an important strategy to accelerate the decline in global TB and achieve TB elimination. Even among low‐TB burden countries that have achieved high rates of detection and successful treatment for active TB, a number of barriers have prevented implementing or expanding LTBI treatment programmes. Of those infected with TB, relatively few will develop active disease and the current diagnostic tests have a low predictive value. LTBI treatment using isoniazid (INH) has low completion rates due to the long duration of therapy and poor tolerability. Both patients and physicians often perceive the risk of toxicity to be greater than the risk of reactivation TB. As a result, LTBI treatment has had a limited or negligible role outside of countries with high resources and low burden of disease. New tools have emerged including the interferon‐gamma release assays that more accurately diagnose LTBI, particularly in people vaccinated with Bacillus Calmette–Guerin (BCG). Shorter, better tolerated treatment using rifamycins are proving safe and effective alternatives to INH. While still imperfect, TB prevention using these new diagnostic and treatment tools appear cost effective in modelling studies in the United States and have the potential to improve TB prevention efforts globally. Continued research to understand the host–organism interactions within the spectrum of LTBI is needed to develop better tools. Until then, overcoming the barriers and optimizing our current tools is essential for progressing toward TB elimination.