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1.
Since the recent introduction of diagnostic kits for hepatitis C and E, some cases of nonA, non-B, non-C, non-D, non-E hepatitis (so-called hepatitis F) have been revealed. We attempted to demonstrate that so-called hepatitis F is caused by hepatitis B virus (HBV) variants. Polymerase chain reaction (PCR) was used to amplify serum HBV DNAs from 20 patients with acute hepatitis and 20 patients with chronic hepatitis who had been diagnosed as having so-called hepatitis F on the basis of conventional serological markers. The PCR technique successfully amplified HBV DNAs in 18 (90%) cases of acute hepatitis and 17 (85%) cases of chronic hepatitis. Sequencing of HBV DNAs of six patients (acute 3, chronic 3) revealed equally a T-to-C mutation of DR2 and an 8-nucleotide deletion of the 3′-terminus of the X gene coding region, giving rise to the generation of a C-terminally truncated X protein and probable damage to the enhancer II/core promoter elements. These mutations of the X gene coding region may lead to suppression of replication and expression of HBV DNAs. Thus virtually all cases of so-called hepatitis F appear to be caused by “silent” HBV mutants, at least in Japan.  相似文献   

2.
乙型肝炎病毒X基因及HBx蛋白的研究进展   总被引:6,自引:0,他引:6  
我国是乙型肝炎高发区,乙型肝炎病毒(HBV)X基因及其编码的多功能蛋白HBx是乙型肝炎病毒基因转录所必需的作用因子,在乙肝的致病过程中起到重要作用。HBx可直接或间接改变肝脏结构细胞的结构和功能,引发肝脏细胞的凋亡;具有广泛的非特异性反式激活作用,反式激活细胞内的某些癌基因或病毒基因,与乙型肝炎和肝细胞癌的发生关系十分密切。本文从多方面综述了X基因及HBx蛋白目前的研究进展,展现了X基因功能的多样性。  相似文献   

3.
目的:构建含有天然完整的乙型肝炎病毒(HBV)X基因序列的真核表达载体,观察其在肝癌细胞株中的表达。方法:设计并合成HBV X基因的引物,用PCR方法从含完整HBV全基因的HepG2细胞中扩增X基因序列,并将其连接到真核表达载体pVAX-1上,酶切、PCR鉴定;用Triton X-114去除质粒内毒素后,采用电穿孔法将重组质粒pVAX-HBV X和空质粒pVAX-1分别转染SMMC-7721细胞,RT-PCR法检测HBV X基因mRNA的表达,Western印迹鉴定HBV X蛋白(HBx)的表达。结果:酶切和PCR鉴定证实pVAX-HBV X载体中包含完整的HBVX基因片段,该重组质粒转染的SMMC-7721细胞中HBV X基因mRNA及HBx蛋白的表达稳定。结论:构建了HBV X基因的真核表达载体,为X基因及其编码蛋白的生物学功能的研究提供了可靠的基因材料。  相似文献   

4.
目的:探讨体外针对乙型肝炎病毒(HBV)X基因的小干扰RNA(siRNA)对HBV复制和抗原表达的抵制作用。方法:利用siRNA表达框架法设计针对HBVX基因的siRNA,转染HepG2.2.15细胞,RT-PCR半定量检测转染前后X基因的表达;ELISA法测定各组24、48、72hHBsAg和HBeAg的含量;荧光定量PCR检测48h时HBVDNA的变化。结果:制备了HBVX基因的siRNA,转染后24、48和72h,HBVX基因mRNA的量分别减少了57%、78%和40%;siRNA能抑制HBsAg和HbeAg的分泌,抑制高峰在48h,抑制率分别为42%和43%;荧光定量PCR证实HBVDNA的复制亦受到抑制。结论:针对HBVX基因的siRNA在体外具有抑制HBV复制和抗原表达的作用。  相似文献   

5.
目的:在巴斯德毕赤酵母中表达乙型肝炎病毒(HBV)X蛋白,为探讨HBVX蛋白与慢性乙型肝炎及肝细胞癌发生的关系奠定基础。方法:用PCR方法扩增X基因序列,并分别在上下游引入XhoⅠ和XbaⅠ酶切位点,插入pPICZαA载体,转化大肠杆菌TOP10,筛选阳性克隆,对其进行PCR和双酶切及测序鉴定,构建HBVX蛋白毕赤酵母表达质粒pPICZαA-HBx;电击转化毕赤酵母GS115,对阳性克隆进行诱导表达后经SDS-PAGE和Western blotting鉴定目的蛋白。结果:双酶切pPICZαA-HBx后,琼脂糖电泳可分别见到大小约为3.1kb和465bp的片段,表明目的片段已插入载体中,序列测定表明其含有完整的X基因片段,Western blotting结果显示含有pPICZαA-HBx的毕赤酵母GS115能分泌表达X蛋白。结论:构建了毕赤酵母表达载体pPICZαA-HBx,并能在毕赤酵母GS115中分泌表达X蛋白。  相似文献   

6.
7.
以HBV-NClDNA为材料研究了其中的X基因,首先确定了此X基因的顺序,即用ABI自动萤光测序议测序证明了此X基因的385位核苷酸后缺失19个核苷酸,从而引起移码突变,使此X基因共有519个核苷酸,编码172个氨基酸,比另一种adr型X蛋白多18个氨基酸。在其第五位氨基酸上有一ATG起始密码,也与另一X基因不同。经重组后获得在大肠杆菌中的热诱导表达,用Westernblot方法证明确为X蛋白,并有多态性。  相似文献   

8.

Background and Aims

The virus/host interplay mediates liver pathology in chronic HBV infection. MiRNAs play a pivotal role in virus/host interactions and are detected in both serum and HBsAg-particles, but studies of their dynamics during chronic infection and antiviral therapy are missing. We studied serum miRNAs during different phases of chronic HBV infection and antiviral treatment.

Methods

MiRNAs were profiled by miRCURY-LNA-Universal-RT-miRNA-PCR (Exiqon-A/S) and qPCR-panels-I/II-739-miRNA-assays and single-RT-q-PCRs. Two cohorts of well-characterized HBsAg-carriers were studied (median follow-up 34–52 months): a) training-panel (141 sera) and HBsAg-particles (32 samples) from 61 HBsAg-carriers and b) validation-panel (136 sera) from 84 carriers.

Results

Thirty-one miRNAs were differentially expressed in inactive-carriers (IC) and chronic-hepatitis-B (CHB) with the largest difference for miR-122-5p, miR-99a-5p and miR-192-5p (liver-specific-miRNAs), over-expressed in both sera and HBsAg-particles of CHB (ANOVA/U-test p-values: <0.000001/0.000001; <0.000001/0.000003; <0.000001/0.000005, respectively) and significantly down-regulated during- and after-treatment in sustained-virological-responders (SVR). MiRNA-profiles of IC and SVR clustered in the heatmap. Liver-miRNAs were combined with miR-335, miR-126 and miR-320a (internal controls) to build a MiR-B-Index with 100% sensitivity, 83.3% and 92.5% specificity (−1.7 cut-off) in both training and validation cohorts to identify IC. MiR-B-Index (−5.72, −20.43/14.38) correlated with ALT (49, 10/2056 U/l, ρ = −0.497, p<0.001), HBV-DNA (4.58, undetectable/>8.3 Log10 IU/mL, ρ = −0.732, p<0.001) and HBsAg (3.40, 0.11/5.49 Log10 IU/mL, ρ = −0.883, p<0.001). At multivariate analysis HBV-DNA (p = 0.002), HBsAg (p<0.001) and infection-phase (p<0.001), but not ALT (p = 0.360) correlated with MiR-B-Index. In SVR to Peg-IFN/NUCs MiR-B-Index improved during-therapy and post-treatment reaching IC-like values (5.32, −1.65/10.91 vs 6.68, 0.54/9.53, p = 0.324) beckoning sustained HBV-immune-control earlier than HBsAg-decline.

Conclusions

Serum miRNA profile change dynamically during the different phases of chronic HBV infection. We identified a miRNA signature associated with both natural-occurring and therapy-induced immune control of HBV infection. The MiR-B-Index might be a useful biomarker for the early identification of the sustained switch from CHB to inactive HBV-infection in patients treated with antivirals.  相似文献   

9.
The United Nations (UN) Convention on the Rights of Persons with Disabilities (CRPD) is the most up‐to‐date international legal instrument concerning the rights of persons with disabilities. Such persons are taken to include those with serious mental disorders. According to an authoritative interpretation of a crucial Article (Article 12 ‐ Equal recognition before the law) by the UN CRPD Committee, involuntary detention and treatment of people with mental health disabilities are prohibited under the Convention. Both conventional mental health law and “capacity‐based” law are deemed to violate the Convention. However, some other UN bodies are not in full agreement (for example, the UN Human Rights Committee and the Subcommittee on Prevention of Torture and Other Cruel, Inhuman or Degrading Treatment or Punishment), while others are less explicitly absolutist (for example, the Human Rights Council). Furthermore, strong criticisms of the position of the CRPD Committee have been mounted from a number of academic quarters. These criticisms center on whether the role of a person's ability to make a decision can be ignored, no matter the circumstances. Much of the above debate turns on the concept of “legal capacity” and the now often‐repeated precept that one must always respect the “will and preferences” of the person with a disability. However, “will and preferences” remains undefined. In this paper, I offer an analysis of “will and preferences” that can clarify interventions that may be acceptable or non‐acceptable under the terms of the UN Convention.  相似文献   

10.
A key goal of aging research was to understand mechanisms underlying healthy aging and develop methods to promote the human healthspan. One approach is to identify gene regulations unique to healthy aging compared with aging in the general population (i.e., “common” aging). Here, we leveraged Genotype‐Tissue Expression (GTEx) project data to investigate “healthy” and “common” aging gene expression regulations at a tissue level in humans and their interconnection with diseases. Using GTEx donors' disease annotations, we defined a “healthy” aging cohort for each tissue. We then compared the age‐associated genes derived from this cohort with age‐associated genes from the “common” aging cohort which included all GTEx donors; we also compared the “healthy” and “common” aging gene expressions with various disease‐associated gene expressions to elucidate the relationships among “healthy,” “common” aging and disease. Our analyses showed that 1. GTEx “healthy” and “common” aging shared a large number of gene regulations; 2. Despite the substantial commonality, “healthy” and “common” aging genes also showed distinct function enrichment, and “common” aging genes had a higher enrichment for disease genes; 3. Disease‐associated gene regulations were overall different from aging gene regulations. However, for genes regulated by both, their regulation directions were largely consistent, implying some aging processes could increase the susceptibility to disease development; and 4. Possible protective mechanisms were associated with some “healthy” aging gene regulations. In summary, our work highlights several unique features of GTEx “healthy” aging program. This new knowledge could potentially be used to develop interventions to promote the human healthspan.  相似文献   

11.
Circadian clocks are autonomous time-keeping mechanisms that allow living organisms to predict and adapt to environmental rhythms of light, temperature and food availability. At the molecular level, circadian clocks use clock and clock-controlled genes to generate rhythmicity and distribute temporal signals. In mammals, synchronization of the master circadian clock located in the suprachiasmatic nuclei of the hypothalamus is accomplished mainly by light stimuli. Meal time, that can be experimentally modulated by temporal restricted feeding, is a potent synchronizer for peripheral oscillators with no clear synchronizing influence on the suprachiasmatic clock. Furthermore, food-restricted animals are able to predict meal time, as revealed by anticipatory bouts of locomotor activity, body temperature and plasma corticosterone. These food anticipatory rhythms have long been thought to be under the control of a food-entrainable clock (FEC). Analysis of clock mutant mice has highlighted the relevance of some, but not all of the clock genes for food-entrainable clockwork. Mutations of Clock or Per1 do not impair expression of food anticipatory components, suggesting that these clock genes are not essential for food-entrainable oscillations. By contrast, mice mutant for Npas2 or deficient for Cry1 and Cry2 show more or less altered responses to restricted feeding conditions. Moreover, a lack of food anticipation is specifically associated with a mutation of Per2, demonstrating the critical involvement of this gene in the anticipation of meal time. The actual location of the FEC is not yet clearly defined. Nevertheless, current knowledge of the putative brain regions involved in food-entrainable oscillations is discussed. We also describe several neurochemical pathways, including orexinergic and noradrenergic, likely to participate in conveying inputs to and outputs from the FEC to control anticipatory processes.  相似文献   

12.
13.
The precursor to all tetrapyrroles is 5‐aminolevulinic acid, which is made either via the condensation of glycine and succinyl‐CoA catalyzed by an ALA synthase (the C4 or Shemin pathway) or by a pathway that uses glutamyl‐tRNA as a precursor and involves other enzymes (the C5 pathway). Certain ALA synthases also catalyze the cyclization of ALA‐CoA to form 2‐amino‐3‐hydroxycyclopent‐2‐en‐1‐one. Organisms with synthases that possess this second activity nevertheless rely upon the C5 pathway to supply ALA for tetrapyrrole biosynthesis. The C5N units are components of a variety of secondary metabolites. Here, we show that an ALA synthase used exclusively for tetrapyrrole biosynthesis is also capable of catalyzing the cyclization reaction, albeit at much lower efficiency than the dedicated cyclases. Two absolutely conserved serines present in all known ALA‐CoA cyclases are threonines in all known ALA synthases, suggesting they could be important in distinguishing the functions of these enzymes. We found that purified mutant proteins having single and double substitutions of the conserved residues are not improved in their respective alternate activities; rather, they are worse. Protein structural modeling and amino acid sequence alignments were explored within the context of what is known about the reaction mechanisms of these two different types of enzymes to consider what other features are important for the two activities.  相似文献   

14.
15.
Universal infantile hepatitis B virus (HBV) vaccination may lead to an increase in vaccine escape variants, which may pose a threat to the long-term success of massive vaccination. To determine the prevalence of occult infections in Korean vaccinated individuals, 87 vaccinated subjects were screened for the presence of HBV DNA using both the nested PCR protocol and the VERSANT HBV DNA 3.0 assay. The mutation patterns of variants were analyzed in full-length HBV genome sequences. Their HBsAg secretion and replication capacities were investigated using both in vitro transient transfection and in vivo hydrodynamic injection. The presence of HBV DNA was confirmed in 6 subjects (6.9%). All six variants had a common mutation type (X8Del) composed of an 8-bp deletion in the C-terminal region of the HBV X gene (HBxAg). Our in vitro and in vivo analyses using the full-length HBV genome indicated that the X8Del HBxAg variant reduced the secretion of HBsAg and HBV virions compared to the wild type. In conclusion, our data suggest that a novel mutation (X8Del) may contribute to occult HBV infection in Korean vaccinated individuals via a reduced secretion of HBsAg and virions, possibly by compromising HBxAg’s transacting capacity.  相似文献   

16.
17.
Concentrations of follicle stimulating hormone (FSH) and luteinizing hormone (LH) in central (C) samples obtained by transfemorally catheterizing the inferior petrosal sinus of female bonnet monkeys were compared with those in peripheral (P) samples obtained simultaneously from the saphenous veins of two intact and two oophorectomized bonnet monkeys, before, during, and after luteinizing hormone releasing hormone (LHRH) stimulation. Significant differences between central and peripheral gonadotropin concentrations were detected intermittently in the resting state, and tended to be magnified by LHRH administration. In one animal in which LHRH was fortuitously administered during the course of a spontaneous LH surge, a C/P ratio for LH of 12.71, the maximum observed, was obtained. Spectral analysis exhibited periodicity for LH and, to a lesser extent, for FSH in the oophorectomized, but not in the intact, animals.  相似文献   

18.
Many of the generalizations made about mosquito behavior and physiology are based on the extensive research on the yellow fever mosquito, Aedes aegypti (L.). However, sufficient differences exist among the numerous species of mosquitoes that make many of these generalizations unwarranted. Some of the specific differences between Ae. aegypti and other mosquito species, particularly the important malaria vector Anopheles gambiae, are discussed.  相似文献   

19.
There exists a general consensus that prolonged grief disorder (PGD), or some variant of PGD, represents a distinct mental disorder worthy of diagnosis and treatment. Nevertheless, confusion remains over whether different names and proposed symptom criteria for this disorder identify the same or different diagnostic entities. This study aimed to determine whether PGD, complicated grief (CG), and persistent complex bereavement disorder (PCBD) as described by the DSM‐5 are substantively or merely semantically different diagnostic entities. Data were derived from the Yale Bereavement Study, a longitudinal community‐based study of bereaved individuals funded by the US National Institute of Mental Health, designed explicitly to evaluate diagnostic criteria for disordered grief. The results suggested that the difference between PGD and PCBD is only semantic. The level of agreement between the original PGD test, a new version of the PGD test proposed for ICD‐11 and the PCBD test was high (pairwise kappa coefficients = 0.80‐0.84). Their estimates of rate of disorder in this community sample were similarly low (~10%). Their levels of diagnostic specificity were comparably high (95.0‐98.3%). Their predictive validity was comparable. In contrast, the test for CG had only moderate agreement with those for PGD and PCBD; its estimate of rate of disorder was three‐fold higher (~30%); its diagnostic specificity was poorer, and it had no predictive validity. We conclude that PGD, PCBD and proposed ICD‐11, but not CG, symptom‐diagnostic tests identify a single diagnostic entity. Ultimately, brief symptom‐diagnostic tests, such as the one proposed here for ICD‐11, may have the greatest clinical utility.  相似文献   

20.
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