乙型肝炎病毒对载脂蛋白A1表达的影响及其机制探讨

目的 探讨乙型肝炎病毒(HBV)对载脂蛋白A1( ApoA1)表达的影响及其调节机制.方法 RT-PCR和Western blot检测HepG2和HepG2.2.15中ApoA1 mRNA和蛋白的表达,全自动生化分析仪检测HBV患者和健康对照者ApoA1和高密度脂蛋白胆固醇(HDL-C)血清学水平,SPSS13.0分析其统计学差异;将HBV感染性克隆pHBV1.3与ApoA1基因启动子共转染HepG2细胞,并测定荧光素酶的活性;RT-PCR和Western blot检测HepG2细胞转染pHBV1.3后ApoA1 mRNA和蛋白表达的变化.结果 HepG2.2.15细胞中ApoA1 mRNA和蛋白的表达水平较HepG2低;ApoA1和HDL-C在乙型肝炎感染者血清学水平明显低于健康对照组(P＜0.05);pHBV1.3在HepG2细胞中抑制ApoA1启动子活性、mRNA和蛋白表达.结论 HBV能够在体内外抑制ApoA1的表达.     

AhR途径,CYP1A1、CYP1B1,雌激素代谢及作用过程中的调节

多环芳烃和多卤化烃是环境中广泛分布的有害物质,可通过与细胞芳烃受体结合,从而影响外来化合物代谢酶系如细胞色素氧化酶P450 1A1、1B1的表达,并通过这些酶的催化作用调控雌激素的代谢及作用,进而部分决定了雌激素对机体的作用效应。上述复杂的过程可受到多种因素的影响。     

Ah receptor, CYP1A1, CYP1A2 and CYP1B1 gene polymorphisms are not involved in the risk of recurrent pregnancy loss

The etiology of recurrent pregnancy loss (RPL) remains unclear, but it may be related to a possible genetic predisposition together with involvement of environmental factors. We examined the relation between RPL and polymorphisms in four genes, human aryl hydrocarbon (Ah) receptor, cytochrome P450 (CYP) 1A1, CYP1A2 and CYP1B1, which are involved in the metabolism of a wide range of environmental toxins and carcinogens. All cases and controls were women resident in Sapporo, Japan and the surrounding area. The Ah receptor, CYP1A1, CYP1A2 and CYP1B1 genotypes were assessed in 113 Japanese women with recurrent pregnancy loss (RPL) and 203 ethnically matched women experiencing at least one live birth and no spontaneous abortion (control). No significant differences in Ah receptor, CYP1A1, CYP1A2 and CYP1B1 genotype frequencies were found between the women with RPL and the controls [Ah receptor: Arg/Arg (reference); Arg/Lys and Lys/Lys, odds ratio (OR)=0.67; 95% confidence interval (CI)=0.40-1.11, CYP1A1: m1m1 (reference); m1m2 and m2m2, OR = 0.86; 95% CI = 0.53-1.40, CYP1A2: C/C and C/A (reference); A/A, OR = 1.16; 95% CI = 0.71-1.88, CYP1B1: Leu/Leu (reference); Leu/Val and Val/Val, OR = 1.18; 95% CI = 0.68-2.02]. The present study suggests that the Ah receptor, CYP1A1, CYP1A2 and CYP1B1 gene polymorphisms are not major genetic regulators in RPL.     

Recombinant human P450 forms 1A1, 1A2, and 1B1 catalyze the bioactivation of heterocyclic amine mutagens in Escherichia coli lacZ strains

Three recombinant human P450 enzymes, forms 1A1, 1A2, and 1B1, were coexpressed with NADPH-cytochrome P450 reductase in an E. coli lacZ strain suitable for detection of the mutagenicity of heterocyclic and aromatic amines. The resulting strains expressed the recombinant P450 holoenzymes at high levels. MeIQ (2-amino-3,4-dimethylimidazo[4,5-f]quinoline) was activated effectively by P450 1A2, weakly by P450 1A1, and not detectably by P450 1B1. MeIQx (2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline) and Trp-P-2 (3-amino-1-methyl-5H-pyrido[4,3-b]indole) were activated by all three enzymes, with form 1A2 the most effective. These strains facilitate analysis of the substrate specificity of human P450 forms that participate in the metabolic activation of carcinogens.     

ApoE基因多态性对毛南族人群血清apoA1、apoB水平的影响

目的 探讨载脂蛋白（apo）E基因多态性对毛南族人群血清apoA1、apoB水平的影响。 方法 收集221名贵州省黔南州毛南族人群血样品,采用免疫透射比浊法测定血清apoA1、apoB浓度;应用聚合酶链反应-限制性片段长度多态性方法（PCR-RFLP）检测apoE2、E3、E4基因多态性。 结果 与apoE2/2+E2/3+E2/4基因型亚组（ n =37）比较,apoE3/4+E4/4基因型亚组（ n =41）和apoE3/3基因型亚组（ n =143）血清apoB水平升高（ P ＜0.05）,apoA1/B比值降低（P ＜0.05）;apoE3/4+E4/4基因型亚组apoB水平高于apoE3/3亚组（ P ＜0.05）。未发现不同apoE基因型亚组间血清apoA1水平差异存在统计学意义（ P ＞0.05）。结论 毛南族人群apoE基因多态性明显影响血清apoB水平和apoA1/B比值,但未见该基因多态性与血清apoA1水平相关联。     

Apolipoprotein A1 levels in oophorectomized women treated with Org OD 14, oestradiol valerate and a placebo

Org OD 14 is a synthetic steroid which in animal bioassays displays oestrogenic as well as very weak androgenic-anabolic properties. Earlier studies have shown that it alleviates oestrogen-deficiency symptoms and retards osteoporosis. OD 14 can be administered continuously with little effect on the endometrium.

The aim of this study was to evaluate the effect of OD 14 on apolipoprotein A1 (Apo-A1), the major protein constituent of the high-density lipoprotein (HDL) fraction, as compared with that of oestradiol valerate (E₂V) and a placebo.

Twenty-two women, who had been oophorectomized when undergoing surgical treatment for stage IB or IIA cervical carcinoma, were given OD 14 2.5 mg/day, a placebo, and E₂V 2 mg/day for a period of 6 wk in each case using a double-blind, cross-over method. Serum Apo-A1 was determined by electro-immunoassay after each treatment period.

There was a marked decrease in Apo-A1 after OD 14 as compared with the levels seen after the placebo and E₂V. This decrease is interpreted as evidence of a strong androgenic influence by OD 14. In epidemiological studies low levels of Apo-A1 have been associated with a higher incidence of atherosclerosis and cardiovascular disease.

Long-term treatment with OD 14 might therefore be hazardous in this respect.     

Distribution patterns of apolipoproteins A1, A2, and B in the wall of atherosclerotic vessels

Summary Atherosclerotic vessels were analysed histochemically for distribution, quantity, and composition of apolipoprotein (Apo) types in the vascular wall. The specimens comprised all stages of atherosclerosis, from very discrete intimal changes to complicated lesions. The vessel specimens were marked with antibodies against human Apo A₁, A₂, and B. Apo A₁ can be demonstrated in even the earliest stage of atherosclerosis, and increases with the progression of the disease. In the initial stage, Apo A₁ is found first in lumen-adjacent layers of the intima, and is evident in deeper layers of the wall as the disease progresses. Arteries of muscular type show accumulation of Apo in an earlier stage (or in greater quantity at the same stage) than arteries of elastic type. At all stages, the amount of Apo A₁ always exceeds that of A₂ and B. In the intima, Apo B is higher than Apo A₂, the media contains hardly any Apo B, and the adventitia has less B than A₂. Within the intimal layer, Apo A₁ and A₂ are found in an intracellular (mainly in foam cells) or in an extracellular location, according to the stage of atherosclerosis. Apo B is almost exclusively extracellular; only cases of advanced atherosclerosis show some intracellular localization (mostly in foam cells), visualized as electron dense lamellar organelles, probably of lysosomal origin. In the media, Apo A₁ and A₂ are accumulated in intracellular deposits, whereas the extracellular storage of Apo A₁ A₂ and B is observed only in cases with the most severe damage. Our investigations suggest that the accumulation of apolipoproteins in the vascular wall is effected not only by insudation from the plasma, but also by neosynthesis and/or metabolism by locally derived cells or cells immigrating in the process of atherosclerosis. The presence of Apo A₁ and A₂ in the vessel wall is now documented, and their role at this site apparently differs from that in the plasma.Dedicated to Professor E. Grundmann on the occasion of his 70th birthday.     

EB病毒转化淋巴母细胞LMP-1,LMP-2A及LMP-2B的表达

目的了解EB病毒转化淋巴母细胞LMP-1,LMP-2A,LMP-2B基因的表达改变。方法采用实时定量PCR方法分别检测并比较同一献血员来源的正常人淋巴细胞与EBV转化淋巴母细胞前后LMP基因(LMP-1、LMP-2A、LMP-2B)的表达改变。采用Western bolt检测LMP-1蛋白表达。结果 LMP-1、LMP-2A、LMP-2B基因在转化淋巴母细胞比在正常人淋巴细胞的表达分别上调863倍、1 763倍、90 078倍。Western bolt检测LMP-1蛋白在转化淋巴母细胞中的表达比正常人淋巴细胞明显增强。结论在EBV转化淋巴母细胞过程中LMP-1、LMP-2A和LMP-2B表达均上调。     

CYP3A5 3, CYP3A4 1B and MDR1 C3435T genotype distributions in Ecuadorians

Polymorphisms in CYP3A genes, such as CYP3A5} and CYP3A4, as well as in the MDR1 gene, which encodes for P-glycoprotein, have been implicated as genetic markers in several disorders. Differences in the frequency distribution of the allelic variants CYP3A5 3, CYP3A4 1B, and MDR1 3435T have been demonstrated between distinct ethnic groups. In this study we examined the frequency of these allelic variants in 317 healthy Mestizo individuals from Ecuador and made comparisons with results reported in the literature. The genotypes were determined by PCR-RFLP. Allele and genotype differences were studied by chi-square test. The MDR1 T allele frequency was similar to that of Spaniard or Asian populations, which is consistent with the ethnic origin of Ecuadorian Mestizo individuals (Amerindian and Spaniard Caucasians). By contrast, the CYP3A5 3 allele frequency was significantly lower in Ecuadorians than in Spaniards and other white populations and higher than in Central Americans, Asians and blacks. CYP3A4 1B was more common in Ecuadorians than in Caucasian or Asian populations but less present than in blacks. The differences in the polymorphism found in this work should be considered in allele-disease association studies.     

Screening for mutations in the exon 26 of the apolipoprotein B gene in hypercholesterolemic finnish families by the single-strand conformation polymorphism method

To date, the only known apolipoprotein B (apo B) mutation causing hypercholesteroletnia is the apo B 3500 Arg → Gln or the familial defective apo B (FDB) mutation. This mutation has not been detected in the Finnish population. We have set up a systematic single-strand conformation polymorphism (SSCP) analysis-based screening method to search for other mutations in the exon 26 of the apo B gene in 21 Finnish hypercholesterolemic probands. The 7572-bp exon 26 covers half of the coding region of the gene including the DNA sequence coding for the putative low-density lipoprotein (LDL) receptor binding site on the apo B protein. Exon 26 was amplified as six 1190- to 1435-bp fragments, each of which was further split into three smaller 213- to 579-bp segments by restriction enzymes. These digestion products were run on nondenaturing polyacrylamide gels using at least three different electrophoretic ccnditions and autoradiographed. All previously known genetic variants in the exon 26 were detected by the SSCP method. A C→T change at nucleotide 7064, in complete association with the XbaI site, was characterized by direct sequencing. This variant did not affect the amino acid sequence of the apo B protein. The SSCP-based procedure appears suitable for systematic screening for DNA sequence changes in large coding regions. © 1994 Wiley-Liss, Inc.     

Map refinement of the Usher syndrome type 1B gene, MYO7A, relative to 11q13.5 microsatellite markers

Usher syndrome (US) is clinically and genetically a heterogeneous group of disorders characterized by the association of deafness with retinitis pigmentosa. So far, eight genes responsible for US have been mapped, of which only the gene responsible for the most common form, USH1B, has been identified. The USH1B is a large gene containing 49 exons and encoding for an unconventional myosin-VIIA (MYO7A). Mutation analysis within the MYO7A gene showed a wide variety of mutations dispersed all over the gene. The present report refines the location of the MYO7A gene relative to microsatellite markers mapped to this region, thereby allowing a reliable and efficient carrier detection by linkage analysis.     

Recurrent Plastic Bronchitis in a Child with 2009 Influenza A (H1N1) and Influenza B Virus Infection

Plastic bronchitis is an uncommon disorder characterized by the formation of bronchial casts. It is associated with congenital heart disease or pulmonary disease. In children with underlying conditions such as allergy or asthma, influenza can cause severe plastic bronchitis resulting in respiratory failure. A review of the literature showed nine cases of plastic bronchitis with H1N1 including this case. We report a case of a child with recurrent plastic bronchitis with eosinophilic cast associated with influenza B infection, who had recovered from plastic bronchitis associated with an influenza A (H1N1) virus infection 5 months previously. To the best of our knowledge, this is the first case of recurrent plastic bronchitis related to influenza viral infection. If patients with influenza virus infection manifest acute respiratory distress with total lung atelectasis, clinicians should consider plastic bronchitis and early bronchoscopy should be intervened. In addition, management for underlying disease may prevent from recurrence of plastic bronchitis.     

Expression of G2-M modulators in thyroid neoplasms: correlation of cyclin A,B1 and cdc2 with differentiation

Previous studies have demonstrated that cell proliferating activity accurately reflects the biological aggressiveness of thyroid neoplasms. In this study, we focused on the G2-M boundary regulators of the cell cycle and investigated the expression of three proteins, cyclin A, cyclin B1 and cdc2. The incidence of cyclin A overexpression was significantly linked to carcinoma differentiation (p < 0.0001) and, in particular, all 21 cases of undifferentiated carcinoma overexpressed this protein. On the other hand, cyclin B1 was overexpressed in four undifferentiated carcinomas (19.0%), but not in carcinomas of other types. Cdc2 overexpression was also related to carcinoma differentiation (p < 0.0001), and was directly linked to cyclin A overexpression (p < 0.0001), but not to cyclin B1 overexpression. No significant relationship could be established between the overexpression of these proteins and the histological type of follicular tumor. These results suggest that cyclin A, rather than cyclin B1, contributes significantly to the aggressive character of thyroid carcinoma, together with cdc2.     

Localization of dopamine D1A and D1B receptor mRNAs in the forebrain and midbrain of the domestic chick

The distribution and cellular localization of dopamine D1A and D1B receptor mRNAs in the forebrain and midbrain of the domestic chick were examined using in situ hybridization histochemistry with ³⁵[S]-dATP labeled oligonucleotide probes, visualized with film and emulsion autoradiography. Labeling for D1A receptor mRNA was intense in the medial and lateral striatum, and moderately abundant in the pallial regions termed the archistriatum and the neostriatum, in the hypothalamic paraventricular nucleus region, and in the superficial gray layer of optic tectum of the midbrain. D1B receptor mRNA was abundant in the medial and lateral striatum, and in the pallial region termed the hyperstriatum ventrale, and moderately abundant in the intralaminar dorsal and posterior thalamus and in the superficial gray of the optic tectum. At the cellular level, about 75% of neurons in the medial striatum and 59% of neurons in the lateral striatum were labeled for D1A receptor mRNA, whereas about 39% of the neurons in the medial striatum and 21% in the lateral striatum were labeled for D1B receptor mRNA. Large striatal neurons were not labeled for D1A or D1B receptor mRNA. The data suggest that while both D1A and D1B receptors mediate dopaminergic responses in many neurons of the avian striatum, primarily D1A receptors mediate dopaminergic responses in the archistriatum and the neostriatum, while primarily D1B receptors mediate dopaminergic responses in the hyperstriatum ventrale and the thalamus.     

Expressions of cyclin E, A, and B1 in Hodgkin and Reed–Sternberg cells: Not suppressed by cyclin-dependent kinase inhibitor p21 expression

p21 Is involved in the control of the mammalian cell cycle through the binding and inhibition of cyclin-dependent kinases. The cyclins are dependent on the phases of the cell cycle, and divided into two classes: mitotic cyclins (A, B1, B2) and G1 cyclins (C, D1, D2, D3, E). The product of the p21 gene is a potent downstream effector of the p53 tumor-suppressor gene function. The Hodgkin and Reed- Sternberg (H & RS) cells in Hodgkin's disease are reported to frequently express p53, p21, and nuclear proliferative activity (Ki-67). To clarify the relationship of p21, p53 and cyclins, we performed the immunohistochemistry of p53, p21, Ki-67, cyclin D1, cyclin E, cyclin A and cyclin B1, using 11 cases with Hodgkin's disease. In addition, we performed p53 gene sequencing of exon 5-8, and in situ hybridization of Epstein-Barr virus (EBV) EBER-1 region, whose products have reported to induce the expression of cyclin D. In this study, in all cases, Ki-67 was expressed in almost all H & RS cells, and p53 and p21 were expressed in H & RS cells. No p53 gene mutations were detected in any case, and p53 protein overexpression did not correlate with p53 gene mutations. The number of p21-positive H & RS cells was significantly related with that of the p53-positive cells. The cyclins E, A, B1 and D1 were also expressed in H & RS cells. Unexpectedly, the expression of the cyclins was not suppressed by p21 and p53 expression. In addition, the existence of EBV was not related to the expression of cyclins. It is considered that H & RS cells are, indeed, in cell cycle and commonly express the cell cyclins, and that the cell cycle of H & RS cells may not be specifically fixed in the G1, S, G2 or M phases.