北京地区TT病毒分离株全基因的克隆及序列测定

目的 克隆和测定北京地区ＴＴ病毒（ＴＴＶ）分离株全基因序列。方法 采用聚合酶链反应（ＰＣＲ）技术从１例临床非甲￣庚型肝炎病人血清中分段扩增ＴＴＶ全基因,获得５个互相重叠的片段,分别长１９９ｂｐ（１－１９９）,１２６７ｂｐ（９０－１３５６,８７８ｂｐ（１３５４－２２３１,１１２９ｂｐ（２１７８－３３０６,４３４ｂｐ（３３０６－３７３９）,用标准的分子生物学方法测定了这５个序列,从而得到全长ＴＴＶ基因     

血清学标志阴性的非甲～戊型炎的病原学研究

目的 对血清学标志阴性的非甲￣戊型肝炎进行病原学研究。方法 用ＨＢＶ ＰＣＲ、ＨＣＶ ＲＴ－ＰＣＲ和ＨＥＶ ＲＴ－ＰＣＲ分别检测血清学标志阴性的非甲￣戊型肝炎患者血清,并对其部分阳性产物进行克隆测序。     

山西地区TT病毒感染的分子流行病学研究

目的 了解山西地区不同人群中ＴＴ病毒（ＴＴＶ）感染状况及ＴＴＶ山西分离株基因型分布情况。方法 用聚合酶链反应（ＰＣＲ）方法对山西地区不同人群血清标本进行检测,分析其基因型。结果 ２４例慢性乙型肝炎患者、３１例非甲￣庚型肝炎患者、５３例职业献血员、１１２例健康产妇中,ＴＴＶ ＤＮＡ阳性率分别为４１．６６％、２９．０３％、５８．４９％、８．９３％;１８例２￣３岁健康儿童血清,１０例ＴＴＶ ＤＮＡ阳性产     

深圳地区不同人群TTV感染情况的调查

目的了解深圳地区不同人群ＴＴＶ的感染情况。方法在ＴＴＶＯＲＦ１保守区设计两对套式引物，建立了检测ＴＴＶＤＮＡ的巢式聚合酶链反应（Ｎｅｓｔｅｄ－ＰＣＲ），用该法对深圳地区９０例一般人群、８８例职业献血员、７９例静脉毒瘾者及２９例非甲庚型肝炎病人进行ＴＴＶＤＮＡ的检测。结果ＴＴＶＤＮＡ在以上４种人群中的阳性率分别为７８％，９０％，４１７％与４４８％，前者与后两者比较差异均有显著性（Ｐ＜００５）。９０例一般人群与８８例职业献血员中，１４例ＴＴＶＤＮＡ阳性者丙氨酸转氨酶（ＡＬＴ）均正常。结论深圳地区一般人群与职业献血员中ＴＴＶ携带者较常见；静脉毒瘾者是ＴＴＶ感染的高危人群；部分非甲～庚型肝炎可能与ＴＴＶ相关     

TTV在肝炎患者中的检测及临床意义探讨

目的研究新近报道与丙氨酸转氨酶异常相关的ＴＴＶ在已知和未知病毒性肝炎中的临床意义。方法设计ＴＴＶ部分基因的特异性引物，用聚合酶链反应（ＰＣＲ）方法检测了１０４例病毒性肝炎的ＴＴＶＤＮＡ，并对１例ＴＴＶ阳性标本克隆测序。结果ＴＴＶＤＮＡ序列与日本ＴＴＶ部分基因序列相对应位置的核苷酸同源性为９８．４％。在１０４例肝炎患者中ＴＴＶＤＮＡ阳性检出率为２４．０％（２５／１０４），其中在非甲～戊和庚型肝炎患者中为４８．０％（１２／４２），在甲型肝炎中为１９．０％（４／２１），乙型肝炎为２５．０％（８／３２），丙型肝炎为１１．１％（１／９），９例ＨＧＶＲＮＡ阳性者中未检出ＴＴＶＤＮＡ。值得注意的是重型肝炎ＴＴＶ检出率极高，其中急性重型肝炎６例中阳性为４例（６６．７％），慢性重型肝炎６例中阳性为３例（５０．０％）。结论ＴＴＶ在我国肝炎病人中存在。在重型肝炎中有较高的发生率，可能是未知病毒致急性和慢性及重型肝炎的病因之一。     

血清学标志阴性的非甲～戊型肝炎的病原学研究

目的对血清学标志阴性的非甲～戊型肝炎进行病原学研究。方法用ＨＢＶＰＣＲ、ＨＣＶＲＴ－ＰＣＲ和ＨＥＶＲＴ－ＰＣＲ分别检测血清学标志阴性的非甲～戊型肝炎患者血清，并对其部分阳性产物进行克隆测序。结果８７例非甲～戊型肝炎血清ＨＢＶＤＮＡ均为阴性，９例（１０．３％）为ＨＣＶＲＮＡ阳性，部分经测序证实为ＨＣＶ１ｂ亚型；余７８例为ＨＢＶＤＮＡ和ＨＣＶＲＮＡ均阴性。该７８例中，１４例因无血清未作ＨＥＶＲＮＡ检测，余６４例中４９例（７６．６％）为ＨＥＶＲＮＡ阴性，１５例（２３．４％）为ＨＥＶＲＮＡ阳性。经序列分析显示，其中９例为典型的中国ＨＥＶ株基因序列，６例变异较大，与典型的中国株基因序列的同源性仅为８０％左右。４９例ＨＢＶＤＮＡ、ＨＣＶＲＮＡ和ＨＥＶＲＮＡ均阴性的血清中１６例（３２．６％）ＨＧＶＲＮＡ阳性。由此可见，该８７例中至少有９例为ＨＣＶ感染，１５例为ＨＥＶ感染，１６例为ＨＧＶ感染。结论对血清学标志阴性的非甲～戊型肝炎的病人应该用ＰＣＲ法进行病原学分型，以明确其诊断     

套式PCR和原位杂交技术检测肝病患者单个核细胞？…

目的 了解慢性乙型肝炎（中度）和原发性肝癌（ＨＢｓＡｇ阳性）患者ＰＢＭＣ内ＴＴＶ ＤＮＡ存在情况。方法 采用套式ＰＣＲ以及原位杂交技术检测外周血单个核细胞（ＰＢＭＣ）内ＴＴＶ ＤＮＡ。结果 套式ＰＣＲＳＷＩＭ２６例慢性乙型肝炎（中度）患者ＰＢＭＣ内ＴＴＶ ＤＮＡ阳性７例。阳性率２６．９％,非常显著高于健康对照（Ｘ＾１２＝１４．３,Ｐ〈０．００１）;２１例原发性肝癌（ＨＢｓＡｇ阳性）虱ＰＢＭＣ内ＴＴ     

肝病患者中庚型肝炎病毒感染的检测

目的探讨临床肝病病人中庚型肝炎病毒（ＧＢＶ－Ｃ／ＨＧＶ）感染情况及临床特点。方法应用庚型肝炎病毒基因组５’ＵＴＲ两对寡核苷酸作为引物，建立逆转录套式聚合酶链反应，检测１６９例不同肝病患者血清标本中ＧＢＶ－Ｃ／ＨＧＶＲＮＡ，并对其中１例ＰＣＲ扩增产物进行克隆及测序。结果１６９例各型肝病病人ＧＢＶ－Ｃ／ＨＧＶＲＮＡ总的检出率为９５％（１６／１６９）。在２９例有手术输血史患者中，３１０％（９／２９）ＧＢＶ－Ｃ／ＨＧＶＲＮＡ呈阳性，明显高于无手术输血史组（５％，Ｐ＜００１）。序列分析显示１株庚肝病毒５’ＵＴＲ部分基因片段与已知庚肝病毒株核苷酸同源性在８９１４％～９８９１％之间。结论ＧＢＶ－Ｃ／ＨＧＶ感染普遍存在于临床肝病患者中，病人感染ＧＢＶ－Ｃ／ＨＧＶ的临床表现未发现有特殊性，ＧＢＶ－Ｃ／ＨＧＶ可能不是非甲～戊型肝炎的主要致病因子。     

应用聚合酶链反应技术检测肝组织中的HBV－DNA

采用聚合酶链反应（ＰＣＲ）技术，对４２例肝活切组织石蜡切片中乙型肝炎病毒（ＨＢＶ）ＤＮＡ进行检测，并与乙肝表面抗原（ＨＢｓＡｇ）的免疫组织化学及血清学检测进行比较，ＨＢＶ－ＰＣＲ阳性率为７３．８％，高于组织及血清ＨＢｓＡｇ阳性率（分别为５９．５％和５０．０％）。３例病理形态呈肝炎改变，而血清ＨＢｓＡｇ（─）的肝组织中有２例检出ＨＢＶ－ＤＮＡ，提示ＰＣＲ的高度敏感性和准确性。８３．３％的门脉性肝硬变和８７．５％的肝细胞癌组织中ＨＢＶ－ＰＣＲ呈阳性，进一步证实了上述两病与ＨＢＶ的关系密切。我们还发现肝细胞淤胆患者ＨＢＶ感染率较高，ＨＢＶ－ＤＮＡ及组织ＨＢｓＡｇ阳性比例各为６／９和４／８。     

应用PCR法检测新生儿肝炎综合征患者HCMV－DNA

应用ＰＣＲ法检测新生儿肝炎综合征患者ＨＣＭＶ－ＤＮＡ长春市儿童医院应用ＰＣＲ检测３０例临床诊断为新生儿肝炎综合征（ＮＨＳ）患者和１４例正常新生儿尿中人巨细胞病毒ＤＮＡ（ＨＣＭＶ－ＤＮＡ）。结果阳性率分别为６６．７％和１４．２９％，两者差异显著。ＨＣＭ...     

TLMV5＇非编码区基因的克隆与序列分析

目的　调查TTV阴性的非甲～庚型肝炎患者中TTV～like mini virus(TLMV)感染情况,对TLMV5＇非编码区(5＇NCR)部分基因进行分子克隆与序列分析。方法　采用巢式PCR技术检测53例T T V阴性的非甲～庚肝炎患者血清TLMV DNA,对PCR产物进行克隆、测序和分析。结果　53例病例中TLMV DNA阳性37例(69.8％),对其中8株TLMV基因克隆测序,并与Takahashi报道的TLMV序列(GenBank Accession No ab 026930、ab026931)比较,其核苷酸序列同源性在64％～83％之间。结论　在T TV阴性的非甲～庚肝炎患者中存在TLMV感染。TLMV5＇NCR基因变异性较大。TLMV的致病性及其与非甲～庚肝炎的关系尚有待进一步研究。     

328例血清TT病毒DNA及其IgG抗体的检测

目的 了解不同人群中TT病毒（TTV）感染情况。方法 根据Okamoto报道的TTV全序列设计引物,建立TTV DNA套式聚合酶链反应,利用该法对81例正常人、92例献血员、123例甲－庚型肝炎,32例非甲－庚型肝炎病人进行TTV DNA检测,同时用ELISA法检测抗TTV IgG。结果 TTV在以上四种人群中阳性率分别为2．5％、2．2％、19．5％、28．1％,抗TTV IgG的阳性率分别为1．2％、3．7％、26．8％、34．4％。前者与后者两者比较差异存在显著性（P＜0．05）;重叠感染中TTV合并HBV的二重感染率最高为75．0％。结论 不同人群匀存在TTV感染;正常人群和职业献血员存在健康携带状态;甲－庚型肝炎和非甲－肝炎病人为高危人群;TTV可与各型肝炎存在重叠感染;TTV除经血传播外,存在其他传播途径,抗TTV IgG可作为TT病毒感染的检测手段。     

中国不同人群的抗TTV血清流行病学及TTV基因不同区段的分子流行病学研究

目的　了解不同人群血清中抗 TTV抗体及ORF1 、ORF2 区段基因的分布状况 ,并分析其间的关系。方法　根据TTV的ORF1 、ORF2 区段的基因序列分别合成巢式PCR引物 ,扩增 2 46例血清标本中的TTV部分基因片段 ;采用TTVORF2 部分基因原核表达抗原 ,应用酶联免疫吸附试验(ELISA) ,检测相同血清标本中TTV抗体。结果　不同人群TTVORF1 、ORF2 基因及抗体检测的阳性率分别为 :有偿献血者 16 0 % (12 75 ) ,10 7% (8 75 )和 2 5 3% (19 75 ) ,甲型肝炎患者 10 0 % (3 30 ) ,16 7% (5 30 )和 16 7% (5 30 ) ;乙型肝炎患者 47 5 % (19 40 ) ,42 5 % (17 40 )和 2 2 5 % (9 40 ) ,丙型肝炎患者 42 9% (15 35 ) ,37 1% (13 35 )和 2 8 6 % (10 35 ) ;丁型肝炎患者 2 0 0 % (3 15 ) ,2 6 7% (4 15 )和13 3% (2 15 ) ;戊型肝炎患者 16 7% (2 12 )、16 7% (2 12 )、33 3% (4 12 ) ;庚型肝炎患者 2 3 8% (5 2 1) ,38 1% (8 2 1)和 2 3 8% (5 2 1) ;非甲～庚型肝炎患者 6 1 1% (11 18) ,5 0 0 % (9 18)和 44 4% (8 18)。统计分析TTVORF1 与ORF2 基因的检出率相关有统计学意义 (P =0 0 0 0 <0 0 1) ;不同人群间基因检出率相差有统计学意义 (P <0 0 1) ;TTV抗体的检出率与TTVDNA的检出率相关无     

TTV infection and its relation to serum transaminases in apparently healthy blood donors and in patients with clotting disorders who have been investigated previously for hepatitis C virus and GBV-C/HGV infection in Belgium

A novel DNA virus, TT virus (TTV), has been proposed as a possible etiologic agent for non A-E hepatitis. The aim of the present study was to determine the prevalence of TTV infection using PCR in healthy blood donors and in patients with clotting disorders who have been investigated previously for GBV-C/HGV and HCV infection in Belgium. In this study, PCR using primers proposed by Takahashi et al. [(1998) Hepatology Research 12:233-239] proved far more sensitive than those used by Okamoto et al. [(1998) Journal of Medical Virology 56:128-132]. The sequence of the PCR products showed 87% identity to the published sequence. TTV was present in 29.7% of healthy blood donors, a figure intermediate between the low rate of infection observed in Scotland and the high rates in the Far East. TTV was detected in 46.5% of 127 patients studied with clotting disorders as compared to 79.5% for HCV and 11.8% for GBV-C/HGV infection. However, there was no impact on the level of serum transaminases. Treatment with interferon for HCV infection co-infected with TTV suppressed temporarily serum TTV DNA. Therefore, it was concluded that TTV DNA is detected frequently in serum of healthy blood donors in Belgium and more often in patients with clotting disorders. TTV does not cause liver disease or contribute to the severity of liver disease.     

High detection rates of TTV-like mini virus sequences in sera from Brazilian blood donors

TT virus (TTV) is an unenveloped virus with a single-stranded, circular DNA genome of 3,818-3,853 nucleotides (nt) that infects humans and non-human primates. Recently, the existence of a novel human virus, TTV-like mini virus (TLMV), that shows a genetic organization similar to that of TTV, but with smaller virion particle and genome, was proposed [Takahashi et al. (2000) Archives of Virology 145:979-993]. To date, no information is available with respect to the prevalence and pathogenicity of TLMV. A sensitive PCR assay was developed by using two oligonucleotide primers (LS2 and LA2) designed from the conserved non-coding region of the TLMV genome. One hundred thirty-seven sera from volunteer Brazilian blood donors were tested and 99 (72%) were TLMV DNA positive. No significant differences were observed between the groups of TLMV positive and negative subjects in relation to sex ratio, seroprevalence of TTV DNA, prevalence of anti-hepatitis A virus antibodies, area of residence, occurrence of daily contact with animals, family income, education level, and level of alanine aminotransferase. The specificity of the PCR assay was demonstrated after cloning of amplification products and determination of the nucleotide sequences (200-228 nt) of clones derived from 23 individuals. When DNAs extracted from TLMV/TTV-coinfected sera were submitted to PCR with LS2 and LA2 primers, the amplification products were derived exclusively from the TLMV genome. A markedly wide range of sequence divergence, even higher than that existent among TTV strains, was noted among TLMV isolates, with a maximum evolutionary distance of 0.80.     

TT病毒在谷丙转氨酶升高的体检者和肝病患者中检 …

目的 通过研究ＴＴ病毒在谷丙转氨酶升高的体检人群和肝病患者中的意义。探讨其致病性。方法 收集１９例谷丙转氨酶升高体验者和４１例转氨酶正常的随机对照的血清,以及１８２例肝病患者的血清,采用ＰＣＲ方法检测ＴＴ病毒的ＤＮＡ。聚合酶链反应（ＰＣＲ）产物经限制性片段长度多态性（ＲＦＬＰ）分析验证。同时检测甲,乙,丙,戊,庚型肝炎病毒（ＨＡＶ,ＨＢＶ,ＨＣＶ和ＨＧＶ）感染标志。结果 １９例转氨酶升高体检者中,     

Distribution of TT virus (TTV), TTV-like minivirus,and related viruses in humans and nonhuman primates

TT virus (TTV) and TTV-like minivirus (TLMV) are small DNA viruses with single-stranded, closed circular, antisense genomes infecting man. Despite their extreme sequence heterogeneity (>50%), a highly conserved region in the untranslated region (UTR) allows both viruses to be amplified by polymerase chain reaction (PCR). TTV/TLMV infection was detected in 88 of 100 human plasma samples; amplified sequences were differentiated into TTV and TLMV by analysis of melting profiles, showing that both viruses were similarly prevalent. PCR with UTR primers also detected frequent infection with TTV/TLMV-related viruses in a wide range of apes (chimpanzees, gorillas, orangutans, gibbons) and African monkey species (mangabeys, drills, mandrills). These findings support the hypothesis for the co-evolution of TTV-like viruses with their hosts over the period of primate speciation, potentially analogous to the evolution of primate herpesviruses.     

Effect of immune modulation on TT virus (TTV) and TTV-like-mini-virus (TLMV) viremia

The present study was designed to investigate how two chronically replicating viruses, TT virus (TTV) and TTV-like mini virus (TLMV), interact with host defence systems. Successive serum samples from three groups of subjects, undergoing modifications of their antiviral defence, were tested by real-time PCR to measure changes in viral titers, and by sequence analyses to indicate whether increases in viremia could be attributed to infection with an unfamiliar strain: 1) in patients receiving immunosuppressants subsequent to kidney transplantation, viral titers tended to increase; 2) in soldiers undergoing extreme training known to cause immunosuppression, insignificant increases in titers were observed; and 3) interferon treatment of patients with hepatitis C virus caused a temporary decrease in TTV and TLMV titers. Increases in viremia were associated only occasionally with the appearance of novel strains. The above results add to knowledge on how these viruses are influenced by the host.