Detection of CYP1A1 protein in human liver and induction by TCDD in precision-cut liver slices incubated in dynamic organ culture

Cytochrome P4501A1 (CYP1A1) has been implicated in the conversion of numerous polycyclic aromatic hydrocarbons into electrophilic species capable of binding covalently to DNA and has therefore been postulated to be involved in the initiation of carcinogenesis. The expression of CYP1A1 protein appears not to be constitutive, but is readily inducible by aryl hydrocarbon (Ah) receptor ligands in a majority of tissues of experimental animals, especially the liver. To date, there is conflicting evidence for the expression or inducibility of CYP1A1 protein in human liver. In this present study, we report the detection of CYP1A1 in all 20 human liver microsomal samples tested by standard western immunoblotting with chemiluminescent detection using a specific monoclonal antibody (mAb 1-12-3) directed against a marine fish (scup) cytochrome P450E. mAb 1-12-3 has been shown previously to specifically recognize CYP1A1 in mammals. This system consistently demonstrated a detection sensitivity as low as 0.01-0.025 pmol CYP1A1 per lane. In the samples where CYP1A1 protein levels were quantitated, CYP1A1 ranged from approximately 0.4 to 5 pmol CYP1A1/mg microsomal protein. Additionally, the inducibility of CYP1A1 protein was demonstrated by incubating precision-cut human liver slices in dynamic organ culture for up to 96 h in the presence of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). The specificity of mAb 1-12-3 was tested using several purified human and rat cytochrome P450s to ensure that the protein being detected was CYP1A1. mAb 1-12-3 did not cross-react with human CYP1A2 or CYP3A4 or rat CYP1B1, but did strongly recognize CYP1A1. However, there was a very weak cross-reactivity of mAb 1-12-3 with human CYP2E1, approximately 75-fold less compared with CYP1A1. In order to confirm CYP1A1 as the immunoreactive protein detected in human liver, microsomal samples were subjected to two-dimensional electrophoresis involving isoelectric focusing followed by SDS-PAGE and immunoblotting. Utilizing mAb 1-12-3, the human liver microsomal samples displayed an immunoblotting profile matching that obtained from a microsomal preparation from a AHH-1 TK+/- cell line expressing solely human CYP1A1 and differing from the profile obtained using a polyclonal antibody directed against CYP2E1 and cells expressing CYP2E1. Furthermore, mAb 1- 12-3 recognized only one protein of identical mobility on the two- dimensional blots from human liver microsomes and AHH-1 TK+/- cells expressing CYP1A1, while displaying no reaction to cells expressing only CYP2E1. In conclusion, CYP1A1 appears to be expressed in human liver at low levels and is inducible upon exposure to TCDD.      

Extradural cavernous haemangioma simulating a disc protrusion

Cavernous haemangiomas confined to the epidural space are rare and are therefore infrequently considered in the differential diagnosis of spinal epidural masses. In order to draw attention to this diagnosis, a case in which an epidural cavernous haemangioma simulates a lateral/foraminal disc protrusion is presented.     

河北省4个地区广泛焦虑症的流行病学调查

目的:了解广泛焦虑症的患病率及人口学特点。方法:于2004-10/2005-03随机抽取河北省邯郸、保定、秦皇岛、承德4个地级市18岁以上人口进行全省精神疾病流行病学现场抽样调查工作,总样本24000人。调查筛选工具采用改编后的一般健康问卷12项,以《DSM-Ⅳ-TR轴Ⅰ障碍定式临床检查》病人版为调查的诊断工具。根据被调查者一般健康问卷12项总分,把被调查者分为高危人群、中危人群、低危人群3类。根据预试验调查结果确定三段危险人群的分界分:总分≥4分属于高危人群,高危人群全部进行DSM-Ⅳ-TR轴Ⅰ障碍定式临床检查;总分为2分或3分即属中危人群,中危人群约40%需进行DSM-Ⅳ-TR轴Ⅰ障碍定式临床检查,总分为0分或1分即属低危人群,低危人群中10%需进行DSM-Ⅳ-TR轴Ⅰ障碍定式临床检查。改编后的一般健康问卷12项分数及内容不变,另外增加8个问题均为高危因素,并进行DSM-Ⅳ-TR轴Ⅰ障碍定式临床检查。结果:①实际完成调查20716人,其中男10343人(49.9%),女10373人(50.1%)。共诊断焦虑症患者127例。②按高中低危因素调整后时点患病率为7.69/1000(95%CI6.50/1000～8.88/1000)。城市患病率4.87/1000,农村患病率8.10/1000,两者差异无显著性意义(u=1.78,P>0.05)。女性患病率明显高于男性,差异有显著性意义(分别为10.42/1000,4.97/1000,u=4.49,P<0.01),男女患病率比例为1:2.10。按不同年龄阶段的人口计算出各年龄段的时点患病率,20～29岁患病率较低(3.17/1000),50～59岁患病率较高(15.56/1000)。③通过12个因素的Logistic回归分析发现,影响广泛焦虑症的危险因素有年龄50～59岁(OR=1.713);保护性因素男性(OR=0.431),年龄20～29岁(OR=0.393),收入10001～20000元(OR=0.568),收入20001～40000元(OR=0.117)。结论:广泛焦虑症的流行病学特征为女性、中老年人患病率较高,男性、青年、收入中等者患病率较低。     

纳米羟基磷灰石/硫酸庆大霉素缓释系统的制备及体内释放实验

目的:制备纳米羟基磷灰石/硫酸庆大霉素缓释系统(drug delivery system,DDS),观察其体内释药特性,为慢性骨髓炎的治疗寻找更好的方法。方法:实验于2004-05/2005-03在南方医科大学珠江医院中心实验室和华南理工大学生物工程与材料学院实验室完成。实验材料:纳米羟基磷灰石(nano-hydroxypatite,nano-HA)、聚羟基丁酸酯-羟基戊酸酯共聚物[poly(3-hydroxybutyrate-hydroxyvalerate),PHBV]、聚乙二醇(polyethylene glycol,PEG)、硫酸庆大霉素(gentamicin,GM)。新西兰大白兔24只。实验方法:①nano-HA/PHBV-PEG-GM-DDS的制备:以nano-HA为载药核心,外包裹生物相容性好且降解可调控的PHBV、PEG,承载GM制成。②采用SPSS10.0统计软件包绘制庆大霉素浓度与抑菌环直径的半对数标准曲线。③体内释放实验:在新西兰大白兔左股骨外上髁钻孔,刮除部分骨质和骨髓,将nano-HA-PHBV/PEG-GM微球自骨窗内植入,分别于术后1,3,5,7,10,14,21,28d8个时间点各选3只大白兔,麻醉后取干骺端松质骨及骨干皮质骨标本。用标准曲线计算出各标本药物浓度,用SPSS10.0统计软件包绘制nano-HA/PHBV-PEG-GM-DDS的释药浓度与时间关系曲线。实验评估:①扫描电镜下观察nano-HA/PHBV-PEG-GM-DDS的微球形态。②nano-HA/PHBV-PEG-GM-DDS的释药浓度与时间的关系。结果:纳入兔24只,均进入结果分析。①nano-HA/PHBV-PEG-GM-DDS微球形态:大小均匀规整,微球平均粒径为345μm,小微球粒径为78μm,微球表面形态一致,为多孔皱缩结构。②nano-HA/PHBV-PEG-GM-DDS释药浓度与时间的关系:术后第1天nano-HA/PHBV-PEG-GM-DDS周围皮质骨和松质骨中庆大霉素质量浓度分别为(110.10±11.70),(97.30±9.60)mg/L,其后逐渐下降,至术后第28天时皮质骨和松质骨中庆大霉素质量浓度仍可分别达(7.30±1.40),(6.80±1.10)mg/L,局部骨组织中庆大霉素质量浓度仍在金黄色葡萄球菌最小抑菌浓度(2mg/L)以上。结论:nano-HA/PHBV-PEG-GM-DDS具有较好的体内缓释作用。     

Current treatment of HIV/hepatitis B virus coinfection

Coinfection with HIV and hepatitis B virus (HBV) has become a significant global health problem. Liver disease is now one of the leading causes of morbidity and mortality in individuals with HIV, particularly those with viral hepatitis. There are a number of agents available with dual activity against HIV and HBV, and effective treatment depends on understanding the potential advantages and pitfalls in using these agents. There are a number of unresolved issues in the management of HIV/HBV coinfection. These include the role of liver biopsy, the significance of normal aminotransferase levels, serum HBV DNA threshold for treatment, treatment end-points, and the treatment of HBV when HIV does not yet require treatment. Treatment of HBV should be considered in individuals with HIV/HBV coinfection with evidence of significant fibrosis (>/=F2), or with elevated serum HBV DNA levels (>2000 IU/mL). Sustained suppression of serum HBV DNA to below the level of detection by the most sensitive available assay should be the goal of therapy, and, at present, treatment of HBV in HIV/HBV coinfection is lifelong. If antiretroviral therapy is required, then two agents with anti-HBV activity should be incorporated into the regimen. If antiretroviral therapy is not required, then the options are pegylated interferon, adefovir or the early introduction of antiretroviral therapy. Close monitoring is necessary to detect treatment failure or hepatic flares, such as immune reconstitution disease. Further studies of newer anti-HBV agents in individuals HIV/HBV coinfection may advance treatment of this important condition.     

Albuminuria in Australian Aboriginal people: prevalence and associations with components of the metabolic syndrome

Aims/hypothesis. To examine the prevalence and associations with the metabolic syndrome of albuminuria among Australian Aboriginal people.¶Methods. Early-morning urine specimens were collected as part of community-based risk factor surveys assessing the prevalence of diabetes and cardiovascular disease in eight remote communities, with a sample size of 1,075 people. Microalbuminuria was defined as urinary albumin : creatinine ratio 3.4–33.9 mg/mmol, macroalbuminuria as albumin : creatinine ratio equal to or greater than 34 mg/mmol.¶Results. There were high prevalences of microalbuminuria (men 22.2 %, women 26.9 %) and of macroalbuminuria (men 10.4 %, women 13.5 %). There were highly statistically significant linear associations of microalbuminuria and macroalbuminuria with increasing number of coexisting components of the metabolic syndrome (hypertension, glucose intolerance, dyslipidaemia, insulin resistance, abdominal obesity): among people with zero, one, two and three to five of these conditions, respectively, prevalence of microalbuminuria was 16 %, 20 %, 36 % and 32 % (p < 0.001); prevalence of macroalbuminuria was 2 %, 6 %, 12 % and 32 % (p < 0.001). There were independent associations of microalbuminuria with hypertension (odds ratio, 95 % confidence interval = 2.36, 1.63–3.42) and diabetes (2.10, 1.28–3.45): macroalbuminuria was independently associated with hypertension (6.39, 3.93–10.4), diabetes (3.49, 1.93–6.28) and abdominal obesity (4.56, 2.40–8.64) and had a weaker association with insulin resistance (1.99, 1.12–3.54). Dyslipidaemia and impaired glucose tolerance were neither independently associated with microalbuminuria or macroalbuminuria, nor was insulin resistance or abdominal obesity independently associated with microalbuminuria.¶Conclusion/interpretation. There was a strong clustering of albuminuria with components of the metabolic syndrome. Diabetes, hypertension and abdominal obesity are major contributors to high rates of albuminuria among Australian Aboriginal people. [Diabetologia (2000) 43: 1397–1403]     

Lamivudine resistance in patients with chronic hepatitis B: role of clinical and virological factors

BACKGROUND: Lamivudine resistance is associated with long-term monotherapy for chronic hepatitis B and can lead to potentially serious clinical consequences. Scant information exists regarding the influence of hepatitis B virus variants in the development of resistance. The present study was designed to identify factors predictive of lamivudine resistance, with a particular focus on the role of precore and basal core promoter variants in the setting of hepatitis B e antigen-negative disease. METHODS: Eighty-five patients, representing four major genotypes, were followed prospectively on lamivudine therapy. Resistance was defined as an increase in viral load, with polymerase gene sequencing confirming a lamivudine resistance mutation. Median follow up was 19 months (6-54 months). The Cox proportional hazards model was used to determine variables independently predicting for the early onset of lamivudine resistance. RESULTS: The rate of lamivudine resistance was 6%, 31% and 51% at 12, 24 and 48 months, respectively. Multivariate analysis identified the precore variant, high baseline alanine aminotransferase (ALT), and persistent viremia (at 6 months) as independent predictors of the early development of lamivudine resistance, with rate ratios of 4.93 (95% confidence interval [CI]: 1.32-18.5), 1.22 (95%CI: 1.08-1.49), and 4.73 (95%CI: 1.49-15.0), respectively (P < 0.05). Female sex predicted early resistance (rate ratio 5.27 [95%CI: 1.23-22.5, P < 0.05]) although numbers were small (n = 12). Genotype did not influence treatment response nor time to onset of resistance. CONCLUSION: Patients with precore variant hepatitis B virus are likely to develop lamivudine resistance early and should be considered for alternate first-line monotherapy. In the future, combination antiviral therapy may limit the development of resistance.     

Human immunodeficiency virus infection and the liver

Liver disease in human immunodeficiency virus(HIV)-infected individuals encompasses the spectrum from abnormal liver function tests,liver decompensation,with and without evidence of cirrhosis on biopsy,to non-alcoholic liver disease and its more severe form,non-alcoholic steatohepatitis and hepatocellular cancer.HIV can infect multiple cells in the liver,leading to enhanced intrahepatic apoptosis,activation and fibrosis.HIV can also alter gastro-intestinal tract permeability,leading to increased levels of circulating lipopolysaccharide that may have an impact on liver function.This review focuses on recent changes in the epidemiology,pathogenesis and clinical presentation of liver disease in HIV-infected patients,in the absence of co-infection with hepatitis B virus or hepatitis C virus,with a specific focus on issues relevant to low and middle income countries.