| a novel dna virus (ttv) associated with elevated transaminase levels in posttransfusion hepatitis of unknown etiology. | by means of representational difference analysis, a viral clone (n22) of 500 nucleotides was isolated from serum of a patient (tt) with posttransfusion hepatitis of unknown etiology. the n22 clone showed a poor homology to any reported sequences. oligonucleotide primers were deduced from the n22 sequence for detecting it by polymerase chain reaction. n22 sequence in serum banded at a sucrose density of 1.26 g/cm3, indicating its association with a viral particle which was designated tt virus (tt ... | 1997 | 9405239 |
| hepatitis tt virus is present in new zealand. | | 1998 | 9640327 |
| ttv a common virus, but pathogenic? | | 1998 | 9683201 |
| detection of a novel dna virus (ttv) in blood donors and blood products. | a newly discovered dna virus, transfusion-transmitted virus (ttv), has been implicated as a cause of post-transfusion hepatitis. we investigated the frequency of ttv viraemia in uk blood donors, and the extent to which ttv contaminates blood products such as factor viii and ix clotting factors. we also investigated the possible aetiological role of ttv in cryptogenic fulminant hepatic failure (fhf). | 1998 | 9683208 |
| presence of a newly described human dna virus (ttv) in patients with liver disease. | a newly described dna virus, named transfusion-transmitted virus (ttv), was recently detected with high prevalence in japanese patients with fulminant hepatitis and chronic liver disease of unknown aetiology. we investigated the presence of this virus in patients with liver disease in the uk to find out whether ttv infection is associated with liver damage. | 1998 | 9683209 |
| tt-virus infection in north american blood donors, patients with fulminant hepatic failure, and cryptogenic cirrhosis. | a novel dna virus, tt-virus (ttv), has been reported in patients with non-a-g posttransfusion hepatitis in japan. we sought to determine whether ttv infection occurs in north american blood donors and to further determine the prevalence of ttv infection in several groups of patients with liver disease, including patients with cryptogenic cirrhosis and idiopathic fulminant hepatic failure. ttv infection was sought by detection of ttv dna in serum by polymerase chain reaction (pcr) using primers g ... | 1998 | 9731581 |
| fecal excretion of a nonenveloped dna virus (ttv) associated with posttransfusion non-a-g hepatitis. | five patients with type b or c hepatocellular carcinoma were found to be infected with a nonenveloped dna virus (ttv) associated with posttransfusion hepatitis of non-a-g etiology. paired feces and serum samples from these patients were tested for ttv dna by polymerase chain reaction with seminested primers and their sequences were compared. ttv dna was detected in sera from all of the patients, while it was detected in feces from three patients, including two with high viral titers in serum. wh ... | 1998 | 9746068 |
| infection with an unenveloped dna virus (ttv) associated with posttransfusion non-a to g hepatitis in hepatitis patients and healthy blood donors in thailand. | an unenveloped single-stranded dna virus (ttv) has been reported in association with posttransfusion and acute and chronic hepatitis of unknown etiology. dna of ttv was tested for by polymerase chain reaction with heminested primers in 127 patients with chronic liver disease and 105 healthy blood donors in thailand. ttv dna was detected in 23 (59%) of the 39 patients without hepatitis b surface antigen or rna of hepatitis c virus, at a frequency significantly higher than the detection in 21 (36% ... | 1998 | 9783691 |
| hepatocellular carcinomas infected with the novel tt dna virus lack viral integration. | a novel dna virus designated tt virus (ttv) was cloned from a patient with posttransfusion hepatitis and is thought to be a new hepatitis virus. at present, hepatitis b virus (hbv) and hepatitis c virus (hcv) are known to induce hepatocellular carcinoma (hcc). but, actually, in japan approximately 5 to 10% of hccs are in hbv-negative and hcv-negative (nbnc) patients. in order to study the possible role of ttv in hepatocarcinogenesis, we investigated the frequency of the ttv genome in liver tissu ... | 1998 | 9790957 |
| detection of sequences of tt virus, a novel dna virus, in german patients. | recently a novel dna virus, designated tt virus (ttv), that possibly accounts for some of the cases of liver disease of unknown aetiology, was identified in japanese patients. using specific primer pairs for conserved regions, we detected ttv dna by pcr in 16/84 (19%) german patients awaiting orthotopic liver transplantation because of decompensated liver cirrhosis (of diverse causes); in 4/25 (16%) patients with non-a-g hepatitis; in 1/7 patients with autoimmune hepatitis; and in one intravenou ... | 1998 | 9820152 |
| presence of tt virus in french blood donors and intravenous drug users. | | 1998 | 9824281 |
| new genotypes of tt virus (ttv) and a genotyping assay based on restriction fragment length polymorphism. | a phylogenetic analysis, using the open reading frame i sequence of 93 tt viruses (ttv) obtained from various geographical areas, indicated that the virus could be classified into six different genotypes including three hitherto unreported genotypes. the high reliability of the six clusters was confirmed by bootstrap analysis. on the basis of these sequence data, a new simple genotyping assay based on a restriction fragment length polymorphism of ttv was developed. using the enzymes ndei and pst ... | 1998 | 9824290 |
| hepatitis tt virus infection in high-risk groups. | the novel hepatitis tt virus first described by a japanese group has been reported to be parenterally transmitted and furthermore, to have been detected in patients with hepatitis of unknown etiology. hence, in the present study its prevalence was investigated within groups at high risk for contracting blood-borne viruses, such as individuals with chronic liver disease, intravenous drug users and recipients of blood and blood products, as compared to voluntary blood donors and pregnant women. to ... | 1998 | 9861559 |
| sequence variability in the putative coding region of tt virus: evidence for two rather than several major types. | recently a new human virus, tt virus (ttv) was identified in the serum of a patient with post-transfusion hepatitis of unknown aetiology. comparative sequence analysis of a 222 nt fragment of orf 1 of ttv was performed to assess the genomic variability of this virus. phylogenetic analysis of the nucleotide sequences of 76 ttv isolates collected in 17 countries segregated them into two major groups: ttv 1 and ttv 2. the ttv 1 group comprised two distinct subgroups, which corresponded to previousl ... | 1998 | 9880026 |
| lack of evidence for an association between ttv infection and severe liver disease. | in 1997 a new human virus, ttv, was identified. the clinical significance of the ttv infection, however, remains unknown. | 1998 | 9949954 |
| infrequent detection of tt virus infection in intravenous drug users, prostitutes, and homosexual men. | tt virus (ttv), a recently discovered dna virus, has been implicated as a cause of non-a to non-c posttransfusion hepatitis. the frequency of ttv in persons considered at high risk for sexual and parenteral infection was investigated (52 prostitutes, 81 homosexual men, 65 intravenous drug users) to assess its mode of transmission. ttv dna was assayed by polymerase chain reaction using primers from conserved regions in the n22 clone. viremia frequency was 4.5%-13.0% in study subjects, not signifi ... | 1999 | 9952377 |
| infection with an unenveloped dna virus (ttv) associated with non-a to g hepatitis in patients with rheumatoid arthritis. | | 1998 | 9973171 |
| tt virus viremia and liver transplantation: no significant increase of the prevalence. | | 1998 | 9988547 |
| distinct genotypes of a nonenveloped dna virus associated with posttransfusion non-a to g hepatitis (tt virus) in plasma and peripheral blood mononuclear cells. | tt virus (ttv) is a nonenveloped, single-stranded dna virus with little sequence homology to known viruses, and associated with elevated transaminase levels in the patients with posttransfusion hepatitis of unknown etiology. the dna of ttv was detected, by semi-nested polymerase chain reaction, in peripheral blood mononuclear cells (pbmc) from the 30 healthy individuals with circulating virus in plasma. a sequence of 222 bases was determined on 6-10 ttv dna clones each from plasma and 6 clones - ... | 1999 | 10022796 |
| high prevalence of tt virus infection in brazilian blood donors. | a recent report has described the molecular cloning and characterization of a novel, single-stranded dna virus, named tt virus (ttv), which was present in the sera of japanese patients with posttransfusion hepatitis of unknown etiology [okamoto et al. (1998) hepatology research 10:1-16]. using a nested polymerase chain reaction assay, sera from brazilian patients with acute non a-c hepatitis and blood donors were examined for the presence of ttv dna sequences. thirty-seven of 52 (71%) patients w ... | 1999 | 10022797 |
| a new genotype of tt virus (ttv) infection among colombian native indians. | serum ttv dna was assayed in 140 native indians and 40 members of the general population in colombia to determine the prevalence of tt virus (ttv) infection among colombian native indians. of the 140 native indians, 23 (16.4%) were positive for ttv dna, compared to 4 (10.0%) of 40 from the general population (p = not significant). the prevalence of ttv dna among native indians was much higher than that of hbsag and anti-hcv. comparison of subjects with and without ttv dna revealed no significant ... | 1999 | 10022798 |
| a prospective study on tt virus infection in transfusion-dependent patients with beta-thalassemia. | a novel dna virus designated tt virus (ttv) has been reported to be involved in the development of posttransfusion non-a-c hepatitis. we evaluated the frequency and natural course of ttv infection in a cohort of transfusion-dependent thalassemic patients in a 3-year follow-up study. ninety-three serum hepatitis c virus (hcv) antibody-negative patients (median age of 8 years; range, 0 to 25) from eight centers were studied. of them, 34 (37%) had an abnormal alanine-aminotransferase (alt) baseline ... | 1999 | 10029577 |
| transfusion-transmitted virus (ttv) in brazil. preliminary report. | ttv is a recently discovered dna virus, isolated from a patient with post-transfusion hepatitis of unknown etiology by japanese researchers. in the present study, we evaluated the presence of ttv among chronic liver diseases patients in são paulo and pará states, representing two geographically distinct brazilian regions. ttv dna was found in 21/105 (20%) and 9/20 (45%) cases from são paulo and pará states, respectively. dna sequence data confirmed the presence of ttv genotypes 1a and 2a, as wel ... | 1998 | 10030083 |
| multiple infection of tt virus (ttv) with different genotypes in japanese hemophiliacs. | to clarify the persistent tt virus (ttv) infection, we studied a possibility of multiple ttv infection by genotype analysis of isolated ttv obtained from seven japanese hemophiliacs. the nucleotide sequences including 222 bp in the open reading frame 1 (orf1) region of 10 ttv isolates from each patient were analyzed and classified into various ttv genotypes such as g1 to g6 by phylogenetic analysis using a n-j method. multiple ttv genotypes were observed in all the hemophiliacs: three different ... | 1999 | 10066448 |
| infection with an unenveloped dna virus (ttv) in patients with acute or chronic liver disease of unknown etiology and in those positive for hepatitis c virus rna. | an unenveloped single-stranded dna virus (ttv) has been reported in association with elevated transaminase levels in patients with posttransfusion hepatitis and in those with acute or chronic liver disease of unknown etiology. to further evaluate the association of ttv with liver disease, ttv dna was searched for in patients with acute or chronic liver disease of various etiologies. | 1999 | 10068097 |
| determination and phylogenetic analysis of partial sequences from tt virus isolates. | sera from french in-patients were tested for the presence of the tt virus (ttv) genome using pcr and degenerate primers located in orf1. thirty-six sequences were determined and compared with those deposited in databases, revealing a high degree of genetic variability between ttv isolates (up to 47% for amino acid sequences). phylogenetic analysis demonstrated the existence of three main groups corresponding to the previously described genotypes 1 and 2 and to a new genotype 3. isolates could be ... | 1999 | 10073702 |
| molecular and biophysical characterization of tt virus: evidence for a new virus family infecting humans. | the recent isolation of a novel dna virus from the serum of a japanese patient (t.t.) has provided the latest possible candidate virus associated with cryptogenic hepatitis. in the present study, we report the complete nucleotide sequence of this virus (ttv) isolated from the serum of a west african. based on pcr studies designed to amplify overlapping regions of the viral genome and sensitivity to digestion with mung bean nuclease, the viral genome is circular and negative stranded, and compris ... | 1999 | 10077657 |
| prevalence and persistence of a novel dna tt virus (ttv) infection in japanese haemophiliacs. | to clarify the clinical implication of a newly discovered 'tt virus (ttv)', we assayed ttv dna in sera from 50 haemophiliacs by a seminested-pcr. ttv dna was detected in 75% (35/50), which was a much higher prevalence than for hbv (hbc-ab), hcv rna, or hgv rna. in particular, ttv dna was found in 44.4% (4/8) of patients who had been treated only with virally inactivated factor viii concentrates. elevated alt levels were observed in patients with hcv rna and ttv dna; however, the elevation in ttv ... | 1999 | 10086806 |
| detection rates of tt virus among children who visited a general hospital in japan. | recently, genomic dna of the novel tt virus (ttv) was isolated from patients suffering from posttransfusion hepatitis of unknown etiology. we examined sera from 197 children who visited the department of pediatrics at toyohashi national hospital. sera were tested for ttv dna by seminested polymerase chain reaction (pcr) using a set of primers synthesized according to the published ttv sequence. ten children were found to be positive for ttv (5.1%). all positive pcr products were directly sequenc ... | 1999 | 10089054 |
| susceptibility of tt virus to interferon therapy. | tt virus (ttv) is a newly identified single-stranded dna virus. we retrospectively analysed serum samples from sixteen patients, infected with both hepatitis c virus (hcv) and ttv, and who had been treated with interferon. an elevated serum alanine aminotransferase level after interferon was associated with persistence of hcv (abnormal in five of seven patients with persistence of hcv compared with normal in all nine patients who showed eradication of hcv) irrespective of persistence of ttv. com ... | 1999 | 10092002 |
| determination of antibodies to tt virus (ttv) and application to blood donors and patients with post-transfusion non-a to g hepatitis in japan. | recently, a nonenveloped single-stranded dna virus named tt virus (ttv) has been reported in association with non-a to g post-transfusion as well as sporadic acute and chronic liver disease. a method was developed for the detection of antibody to ttv (anti-ttv) by means of immune precipitation and detection of ttv dna by the polymerase chain reaction. the test serum was incubated with ttv, recovered from feces of a carrier, and after incubation, the formed immune complexes were precipitated with ... | 1999 | 10092143 |
| the acronym ttv. transfusion transmitted virus. | | 1999 | 10094021 |
| tt virus infection among blood donors and patients with non-b, non-c liver diseases in korea. | a novel virus, designated the tt virus (ttv), was isolated from the serum of a patient with posttransfusion hepatitis of unknown etiology, in japan. subsequently, ttv was suggested to be a causative agent in a proportion of cases with cryptogenic hepatitis in japan. this study aimed to elucidate the significance of ttv infection in cases with cryptogenic liver disease in korea, a neighbor of japan. | 1999 | 10190719 |
| prevalence of transmitted transfusion virus (ttv) in populations at different risk for hepatitis virus: hemodialysis, chronic hepatitis c and cryptogenetic hepatitis patients. | | 1999 | 10190744 |
| early acquisition of tt virus (ttv) in an area endemic for ttv infection. | tt virus (ttv) is widely distributed, with high frequencies of viremia in south america, central africa, and papua new guinea. the incidence and timing of infection in children born in a rural area of the democratic republic of congo was investigated. ttv viremia was detected in 61 (58%) of 105 women attending an antenatal clinic and in 36 (54%) of 68 infants. most infants acquired the infection at >/=3 months postpartum. surprisingly, ttv infection was detected in a large proportion of children ... | 1999 | 10191206 |
| prevalence of tt virus infection in us blood donors and populations at risk for acquiring parenterally transmitted viruses. | two overlapping sets of tt virus (ttv)-specific polymerase chain reaction primers were used to test for presence of ttv, which was found in approximately 10% of us volunteer blood donors, 13% of commercial blood donors, and 17% of intravenous drug abusers. the rate of ttv infection among us non-a, non-b, non-c, non-d, non-e hepatitis patients was only 2%. among commercial blood donors and intravenous drug abusers, only 1%-3% of the ttv-positive individuals were coinfected with gb virus c (gbv-c) ... | 1999 | 10191229 |
| excretion into bile of a novel unenveloped dna virus (tt virus) associated with acute and chronic non-a-g hepatitis. | recently, an unenveloped, single-stranded dna virus named tt virus (ttv) has been reported in association with hepatitis of non-a-g etiology. five patients with ttv viremia, who received bile drainage or cholecystectomy, were tested for ttv dna in bile by polymerase chain reaction with heminested primers. ttv dna was detected in bile from all patients; titers were 10-100 times higher than in serum in 4 and at a comparable level in the remaining 1 patient. ttv dna was detected in feces, also, in ... | 1999 | 10191230 |
| tt virus in bone marrow transplant recipients. | tt virus (ttv) is a newly discovered transfusion-transmissible dna virus, which may cause posttransfusion hepatitis. the virus was detected in 12% of japanese blood donors. the aim of the study is to investigate the prevalence and clinical influence of ttv in bone marrow transplant (bmt) recipients. sera from 25 bmt recipients obtained 6 to 12 weeks after the transplant were examined for ttv-dna by the seminested polymerase chain reaction. serial samples were additionally analyzed in patients wi ... | 1999 | 10194426 |
| identification of a novel gc-rich 113-nucleotide region to complete the circular, single-stranded dna genome of tt virus, the first human circovirus. | the sequence data (h. okamoto et al., hepatol. res. 10:1-16, 1998) of a newly discovered single-stranded dna virus, tt virus (ttv), showed that it did not have the terminal structure typical of a parvovirus. elucidation of the complete genome structure was necessary to understand the nature of ttv. we obtained a 1.0-kb amplified product from serum samples of four ttv carriers by an inverted, nested long pcr targeted for nucleotides (nt) 3025 to 3739 and 1 to 216 of ttv. the sequence of a clone o ... | 1999 | 10196248 |
| tt virus: an agent of transfusion-associated hepatitis or yellow herring? | | 1999 | 10207775 |
| prevalence of tt virus before and after blood transfusion in patients with chronic liver disease treated surgically for hepatocellular carcinoma. | to examine the prevalence of tt virus (ttv) before and after blood transfusion, we retrospectively examined serum samples obtained from 55 patients who received blood transfusions before, during and after resection of hepatocellular carcinoma. | 1999 | 10207786 |
| association of hepatitis viruses with hepatocellular carcinoma in thailand. | hepatocellular carcinoma (hcc) represents the most common form of malignant tumor among males in thailand, an area endemic for hepatitis b virus (hbv) infection. various risk factors have been associated with the development of hcc, among them exposure to certain toxins, and infection with hepatitis viruses, in particular hbv, as well as hcv in areas non-endemic for hbv infection. to examine the association of hepatitis viruses with hcc, our group investigated 101 patients who had been clinicall ... | 1999 | 10213123 |
| transmission of and liver injury by tt virus in patients on maintenance hemodialysis. | to study the prevalence and clinical significance of tt virus (ttv) infection in hemodialysis patients, we tested for ttv dna in serum, using the nested polymerase chain reaction. the prevalence of ttv dna in 352 hemodialysis patients was 32%, significantly higher than that in 50 healthy blood donors (12%). the prevalence increased with age (p = 0.0098): it was 20% (22/110) in patients aged less than 49 years, 37% (69/188) in those aged 50-69 years, and 41% (22/ 54) in those aged over 70 years. ... | 1999 | 10213124 |
| tt virus (ttv) is unlikely to cause chronic liver damage. | | 1999 | 10213136 |
| tt virus (ttv) is not associated with acute sporadic hepatitis. | a novel virus, tt virus (ttv), recently discovered by okamoto et al. in the serum of a patient with posttransfusion hepatitis, is thought to be one of the causative agents of blood-borne acute hepatitis. the association of this virus with acute sporadic hepatitis was evaluated. ttv dna was detected in 4 (4.9%) of 81 cases of acute hepatitis a, in 5 (16.7%) of 30 cases of acute hepatitis b, in 1 (25.0%) of 4 cases of acute hepatitis c, in 1 (9.1%) of 9 cases of cytomegalovirus and eppstein-barr i ... | 1999 | 10219644 |
| [the tt virus: another accidental tourist?]. | | 1999 | 10228327 |
| tt virus in frequently transfused patients. | | 1999 | 10320126 |
| high prevalence of tt virus infection in healthy children and adults and in patients with liver disease in taiwan. | a newly identified dna virus, named tt virus (ttv), was found to be related to transfusion-associated hepatitis. we conducted the following experiments to evaluate its pathogenic role in liver disease and potential modes of transmission. we used pcr to detect ttv dna in serum. the rates of ttv viremia in 13 patients with idiopathic acute hepatitis, 14 patients with idiopathic fulminant hepatitis, 22 patients with chronic hepatitis, and 19 patients with cirrhosis of the liver were 46, 64, 55, and ... | 1999 | 10325332 |
| detection of a novel dna virus (ttv) sequence in peripheral blood mononuclear cells. | dna sequences of a novel dna virus (ttv) were examined in 81 peripheral blood mononuclear cell (pbmc) dna samples from 48 children and 33 adults, 22 cord blood mononuclear cells (cbmc) dna samples, and 7 autopsy liver tissue dna samples by a hemi-nested polymerase chain reaction (pcr). the pcr was carried out using the published primers (ng059, ng061, ng063) to amplify ttv dna sequences. the sequences were detected in 4 of 81 (5%) pbmc dna samples, in none of 22 (0%) cbmc dna samples, and in 2 o ... | 1999 | 10335866 |
| infection by an unenveloped dna virus associated with non-a to -g hepatitis in japanese blood donors with or without elevated alt levels. | an unenveloped, single-stranded dna virus named tt virus has been found in association with elevated alanine aminotransferase (alt) levels in recipients of transfusions and has been detected frequently in patients with acute or chronic hepatitis of non-a to -g etiology in japan. dna of the tt virus was searched for in blood donors with or without elevated alt levels. | 1999 | 10336003 |
| the role of tt virus infection in acute viral hepatitis. | recently, transfusion-transmitted virus (ttv) was discovered to be a potential causative agent for non-a-e hepatitis. little is known about the relation between ttv and the clinical courses of various types of acute viral hepatitis. one hundred twenty-five patients with acute viral hepatitis who were admitted to the chiba university hospital between 1984 and 1998 and 100 persons with normal liver function tests were tested for the presence of ttv in their sera. serum samples were tested for ttv ... | 1999 | 10347137 |
| tt virus infection in patients with hepatitis c: frequency, persistence, and sequence heterogeneity. | tt virus (ttv) was recently identified in the serum of a patient with hepatitis. the role of ttv in liver disease has not been established. three polymerase chain reaction (pcr) protocols were used to detect ttv dna in sera of persons infected with hepatitis c virus (hcv) and in blood donors. sera from 11.5% of hcv-infected patients and 7.7% of blood donors were positive by protocols 1 or 2. in contrast, 48.7% and 57.7% of sera, respectively, were positive when tested by protocol 3. there was no ... | 1999 | 10353857 |
| prevalence and clinical significance of tt virus coinfection in patients with chronic hepatitis c treated with interferon. | | 1999 | 10364064 |
| tt virus: a mother-to-child transmitted rather than bloodborne virus. | | 1999 | 10366257 |
| tt virus infection in chronic liver disease. | the exact role of the novel hepatotropic tt virus regarding the etiology of viral hepatitis, as well as the progression towards chronic liver disease has as yet not been defined. moreover, the contribution of ttv infection to the course of chronic hepatitis b or c virus infections also still awaits clarification. hence, the aim of our study was to investigate the impact of ttv infection on clinical severity and histology of chronic liver disease originating from hbv and/or hcv infections in thai ... | 1999 | 10370666 |
| [molecular epidemiology of tt virus infection in some parts of china]. | to study the molecular epidemiology of new hepatitis tt virus (ttv) infection, its distribution in population and its role in pathogenesis of hepatitis in some parts of our country. | 1998 | 10374585 |
| tt virus infection among ivdus in south western china. | to elucidate the prevalence and clinical implications of infection with the newly described tt virus (ttv) among intravenous drug users (ivdus) in yunnan, southwest china, serum samples from 158 ivdus (129 m, 29 f; mean age 26.1 +/- 5.5 years) were examined for ttv dna by semi-nested polymerase chain reaction (pcr) using primers derived from the open reading frame (orfi) of ttv dna. the seroprevalence of viral markers of hiv, hbv, hcv and gb virus c/hepatitis g virus (gbv-c) infection was also e ... | 1999 | 10381213 |
| transfusion-associated tt virus infection and its relationship to liver disease. | tt virus (ttv) has been proposed as the causative agent of non-a to e hepatitis. we studied the association between ttv viremia and biochemical evidence of hepatitis in blood donors and prospectively-followed patients. ttv was found in 7.5% of 402 donors and in 11.0% of 347 patients before transfusion. the rate of new ttv infections was 4.7% in 127 nontransfused, and 26.4% in 182 transfused patients (p <.0001). the risk of infection increased with the number of units transfused (p <.0001). the r ... | 1999 | 10385668 |
| a case-control study on a novel dna virus (tt virus) infection and hepatocellular carcinoma. the brescia hcc study. | we performed a case-control study to evaluate the association of a new human dna virus named tt virus (ttv) with hepatocellular carcinoma (hcc). we recruited 174 subjects hospitalized for hcc (84% males; mean age: 64 years) and 118 patients hospitalized for non-liver diseases in brescia, northern italy, as controls (94% males; mean age: 66 years). ttv dna was found in serum by polymerase chain reaction (pcr) in 26 cases (15%) and 11 controls (9.3%) (p >. 1). ttv group 2 infection was identified ... | 1999 | 10385670 |
| marked genomic heterogeneity and frequent mixed infection of tt virus demonstrated by pcr with primers from coding and noncoding regions. | a nonenveloped, single-stranded, and circular dna virus designated tt virus (ttv) has been reported in association with hepatitis of unknown etiology. ttv has a wide sequence divergence (approximately 52%), by which it is classified into at least 16 genotypes separated by an evolutionary distance of >0.30. therefore, the detection of ttv dna by polymerase chain reaction would be influenced by primers deduced from conserved or divergent regions of the genome. of the 30 sera from healthy individua ... | 1999 | 10388666 |
| the entire nucleotide sequence of a tt virus isolate from the united states (tus01): comparison with reported isolates and phylogenetic analysis. | a nonenveloped and single-stranded dna virus designated tt virus (ttv) has been reported from japan in association with hepatitis of unknown etiology. very recently, the prototype ttv isolate (ta278) of genotype 1 is proven to have a circular genome with 3852 nucleotides. a ttv isolate (tus01) was recovered from a blood donor in the united states, and its entire circular nucleotide sequence of 3818 nucleotides was determined. it possessed two open reading frames coding for 761 and 156 amino acid ... | 1999 | 10388667 |
| [molecular virology of tt virus]. | in 1997, a novel dna virus was isolated from the serum of a patient with posttransfusion hepatitis of unknown etiology in japan, and it was named tt virus (ttv) after the initials of the index patient. ttv is a nonenveloped, single-stranded and circular dna virus, and its entire nucleotide sequence of 3.9 kb has been determined. for being a dna virus, ttv has a wide range of sequence divergence, allowing the classification into at least 16 genotypes separated by an evolutionary distance of > 0.3 ... | 1999 | 10390976 |
| [molecular evolution and genotype classification of tt virus]. | based on sequences data, ttv have a partial rep protein motifs found among circoviridae and the conserved region of parvoviral nonstructural polypeptides (ns)-1 genes, however we could not perform phylogenetic analyses among ttv and other viruses because of few similar sequences. putative orf2 among g2 and g4 encoded 49 aa because of in-frame stop codon, although that of g1 encoded 202 aa. just down-stream of the stop codon, another putative new orf(orf3) were found around 150 aa. a phylogenetic ... | 1999 | 10390977 |
| [the association of ttv genetic variant with liver disease]. | tt virus (ttv), a novel dna virus, has been reported in non-a to non-g posttransfusion hepatitis patients. among 61 japanese patients with liver diseases of non-b and non-c etiology, ttv dna was detected in 15(25%) patients. the n22 region of ttv was sequenced and compared with the published sequence. four genetic groups corresponding to g1a, g1b, g2 and g4 were formed. ttv was detected persistently regardless of its genotype/subtype. however, g2 and g4 contained 10 to 100 folds lower in titer t ... | 1999 | 10390978 |
| [development of the quantification method of ttv-dna and clinical application]. | we developed a method to measure the quantity of ttv-dna. this measurement is based on the principle of the real time pcr method using the taqman probe. by measuring the change of the fluorescent intensity caused by fret, we could detect the amount of ttv-dna. this method has the characteristics that the possibility of the contamination is very rare when it is compared with the usual pcr method, because the reaction system contains ung and dutp. this quantification method is useful for the futur ... | 1999 | 10390979 |
| [incidence of tt virus infection in patients with non-a to g liver disease]. | the sera of patients with liver disease associated with non-a to g hepatitis were examined for the presence of ttv dna. these patients included 18 cases with ah, 8 cases with ch, 6 cases with lc, 4 cases with hcc, and 36 cases with blood donors. the detection of ttv dna was performed as described by nishizawa et al. ttv dna was detected in 60.0%, 62.5%, 66%, 50%, 28% of the patients with ah, ch, lc and hcc, respectively. among the patients with ah, the aminotransferases and total bilirubin value ... | 1999 | 10390985 |
| [detection of tt virus dna in patients with non-a to g liver diseases]. | a novel single-stranded dna virus, tt virus(ttv), has been reported recently. we detected ttv viral sequences by polymerase chain reaction using primers derived from nucleotide sequences of orf1 and the 5' noncoding region of orf2. using primers of the 5' noncoding region, ttv dna was detected in 21 of 25(84%) healthy individuals, suggesting that most ttv strains detected by these primers are almost harmless. in contrast, using primers of orf1, which detect genotype 1a ttv that was reported to b ... | 1999 | 10390986 |
| [detection of tt virus in healthy volunteer]. | a novel dna virus, tt virus(ttv), has been reported in japanese patient with non a to g posttransfusion hepatitis. we sought to determine whether ttv infection occurs in healthy volunteer, and to compared with dna extraction methods and polymerase chain reaction(pcr) primer for ttv in diagnostic system. using a nested pcr assay, serum sample of healthy volunteer serve our laboratory in japan were examined for the presence of ttv dna. twenty of 90(22%) healthy volunteer were detected to have ttv ... | 1999 | 10390987 |
| [ttv infection in healthy subjects]. | recently, a novel hepatitis related virus was described and named as ttv. the positive rates of ttv dna in healthy subjects to far reported ranged from 1% to 62%, therefore, there must be large differences in the prevalence of ttv in healthy subjects from country to country. however, detailed data are lacking in many reports, care should be taken in analyzing them. generally, elderly subjects tend to have increased positivity in the same area. sanitary environment may influence the positive rate ... | 1999 | 10390988 |
| [tt virus(ttv) infection in patients with acute hepatitis]. | a novel dna virus, tt virus(ttv), has been reported in patients with posttransfusion hepatitis of unknown etiology. however association between ttv and acute hepatitis has not been shown. we investigated the prevalence of ttv in acute hepatitis. ttv-positive rates in acute hepatitis a, b, c, cytomegalovirus infection, epstein-barr virus infection, and acute hepatitis of unknown etiology were 15.3%, 21.8%, 60.0%, 0%, 10.0%, 22.6%, respectively. there were no significant differences in ttv prevale ... | 1999 | 10390991 |
| [ttv superinfection on acute hepatitis b]. | tt virus(ttv) was recently reported as candidate for a new hepatitis virus from post transfusion hepatitis of unknown etiology. in the present study, influence of ttv superinfection on acute hepatitis b was analyzed. ttv dna was detected in sera from 10 of 44(23%) patients with acute hepatitis b, but prevalence was comparable with normal blood donor. it was unlikely that ttv superinfection affected clinical course of acute hepatitis b. in cases of ttv superinfection on hepatitis b, t. bil and al ... | 1999 | 10390992 |
| [clinical feature of ttv-related hepatitis]. | it has been clarified that hepatitis g/gb virus-c is the minor cause of acute and chronic non-a-e hepatitis. but there exist non-a-e viral hepatitis patients. recently, one of non-a-e hepatitis associated virus was identified and the new virus was named tt virus. we highly detected tt virus in the serum of hepatitis patients. tt virus were reported to be detected 1-37% of the general population in the world. tt virus may account for only a minor part of acute non-a-e hepatitis in japan. however, ... | 1999 | 10390993 |
| [prevalence of tt virus in patients with fulminant hepatic failure in japan]. | a novel virus(ttv) was isolated from patients with post-transfusion hepatitis of unknown etiology. we studied the prevalence of ttv in 26 patients with fulminant hepatic failure. serum samples at admission from seven(27%) of the 26 patients were positive for ttv. ttv was also detected in 29(27%) of the 106 healthy blood donors. there were no differences in the positive rate between patients with fulminant hepatic failure and healthy blood donors. there were no differences in clinical findings, o ... | 1999 | 10390994 |
| [high prevalence of tt virus(ttv) in patients with non a to non g fulminant hepatitis: differences of clinical features and prognosis between ttv positive and negative patients]. | we detected ttv-dna in sera from 36 patients with fulminant hepatitis(fh) and evaluated differences in clinical features and prognosis between ttv-dna positive and negative patients with nona-nong fh. ttv-dna in sera was measured by nested pcr. twenty of 36 patients with fh were diagnosed nona-nong fh. the ttv-dna in sera was detected in 14 patients(38.9%) with fh, 9(64%) showed nona-nong fh and 3 were hbv fh and 2 were drug-induced fh. although we compared clinical features(gender, age, distrib ... | 1999 | 10390995 |
| [clinical manifestations and histopathologic features of chronic liver disease with serum tt virus (ttv) dna positive alone as measured by first generation primer sets]. | to determine the clinical manifestations and histopathologic features of serum ttv dna-positive chronic liver disease, we investigated eleven patients who showed serum ttv dna alone, as detected by the polymerase chain reaction using first generation primer sets (rd primer series). clinical manifestations were as follows: (1) biochemical abnormalities of the alt-dominant and gamma-gtp-dominant types; (2) persistently elevated gamma-gtp despite normalization of alt in gamma-gtp-dominant type pati ... | 1999 | 10390996 |
| [histological findings of ttv-positive non-b non-c chronic hepatitis patients]. | tt virus has been reported in association with patients with acute and chronic liver disease of unknown etiology. in order to estimate the pathogenesis of ttv, we investigated the liver histology in the patients of ttv-positive chronic hepatitis. the findings frequently observed in ttv-dna positive cases were changes in liver parenchyma such as focal necrosis, hepatocyte degeneration or fatty change of various degree. on the other hand, degree of chronic inflammation in portal areas such as lymp ... | 1999 | 10390997 |
| [the prevalence of ttv infection in non-a to g chronic liver disease, especially non-a to g hepatocellular carcinoma, and the clinical significance of ttv infection]. | we examined the prevalence of tt virus (ttv) infection in non-b, non-c, non-g chronic liver disease, in particular, in hepatocellular carcinoma (hcc), and the clinical significance of ttv infection. among 829 cases with chronic liver disease, 30 cases (4%) had non-b, non-c, non-g chronic liver disease. the percentage of ttv-dna positive cases among these 30 cases with non-b, non-c, non-g chronic liver disease was 57% (17/30), significantly higher than the percentage ttv-dna positivity (14%; 5/10 ... | 1999 | 10390998 |
| [detection of tt virus (ttv) in non-b, non-c hepatitis patients with hepatocellular carcinoma, and clinical features of these patients]. | a novel human dna virus, ttvirus (ttv), was identified from a patient with posttransfusion hepatitis of unknown etiology. it is thought to be a new hepatitis virus, but the clinical significance of this virus is uncertain. we investigated the frequency of ttv viremia by pcr in 39 non-b, non-c hepatitis (nbnc) patients with hepatocellular carcinoma (hcc), and clinical features of these patients. ttv viremia was detected in 20 (51.3%) of 39 nbnc hepatitis patients with hcc. liver cirrhosis (lc) we ... | 1999 | 10391000 |
| [prevalence of tt virus infection and viral integration in human hepatocellular carcinoma]. | in 1997, nishizawa et al cloned a novel dna virus designated as tt virus (ttv) from a patient with post-transfusion hepatitis and this virus is being thought to be a new hepatitis virus. approximately 5 to 10% of hepatocellular carcinomas (hccs) in japan occurs in hepatitis b virus-negative and hepatitis c virus-negative (nbnc) patients. in order to study the possible role of ttv in hepatocarcinogenesis, we studied the prevalence of the ttv dna in liver tissue of hcc patients. as a result, ttv w ... | 1999 | 10391001 |
| [detection of ttv dna in hepatocellular carcinoma]. | a new hepatitis agent, ttv has been cloned from post-transfusion hepatitis patient sera. this virus has a single stranded dna as genome, surrounded by viral capsid antigen without envelope. it might be a member of parvoviridae. but genome organization is far from the known parvoviridae such as b19 and adeno-associated virus. although this virus could be a new causative agent for nona-nong hepatitis, high healthy carrier rate, no relation with hepatocellular carcinoma and no evidence of amplifica ... | 1999 | 10391002 |
| [tt virus infection in patients with hepatocellular carcinoma associated with non-a to g hepatitis: histopathological study]. | to study if ttv infection is involved in the development of hepatocellular carcinoma (hcc), we tested the sera of 19 patients with hcc associated with non-a to g hepatitis for the presence of serum ttv dna, and compared the blood chemistry values and liver histology of the patients in the ttv dna-positive and -negative groups. detection of ttv dna was performed described as nishizawa, et al method. ttv dna was detected in the sera of 47.4%. there were no significant differences in the blood chem ... | 1999 | 10391003 |
| [virological response to interferon therapy in patients dually infected with tt virus and hepatitis c virus]. | in 30 chronic hepatitis c patients co-infected with ttv, ttv dna in the sera immediately after cessation of ifn and 6 months after the end of ifn was examined. sustained loss of ttv dna was observed in 12 of 30 (40.0%) patients. in 7 of 30 (23.3%) patients, ttv dna re-appeared 6 months after becoming undetectable at the end of ifn therapy. in the remaining 11 patients (36.7%), ttv dna remained detectable during the entire follow-up period. the alt values correlated only with the presence of hcv ... | 1999 | 10391004 |
| [susceptibility of tt virus to interferon therapy]. | a novel single stranded dna virus, tt virus, associated with posttransfusion hepatitis was identified. the impact of the virus on development of chronic liver diseases and the susceptibility of the virus to interferon therapy has not been investigated. we retrospectively analyzed blood samples from 16 patients infected with both hepatitis c virus and tt virus who were treated by interferon. tt virus dna was detected by nested polymerase chain reaction before, during and after interferon. eight o ... | 1999 | 10391005 |
| [tt virus infection in an area of high-endemicity for hepatitis c]. | tt virus (ttv) was recently identified as a candidate for a new hepatitis virus. in the present study, the clinical features and transmission routes of ttv infection were analyzed in an area highly endemic for hepatitis c virus (hcv) infection, and compared to those in an area not endemic. in conclusion, the prevalence of ttv infection was as high as 58% in the high-endemicity area for hcv infection. the main transmission route for ttv appeared to be different from that of hcv and hgv. ttv infec ... | 1999 | 10391006 |
| [seroepidemiological survey of tt virus (ttv) infection in an endemic area for hepatitis c virus]. | seroepidemiological survey of tt virus (ttv) infection was performed in the inhabitants living in an endemic area for hepatitis c virus (hcv) in gifu prefecture, japan. in this area, 482 of 1062 inhabitants (45.4%) were seropositive for hcv relative antibodies. ttv-dna was detected in the sera from 12 of 88 inhabitants (13.6%). the positive rate of ttv-dna had no relation to sex or age. the ttv dna-positive rate of the inhabitants with hcv infection was 21.4% higher than that of the inhabitants ... | 1999 | 10391007 |
| [detection of tt virus (ttv) in japanese hemodialysis (hd) patients]. | the clinical and epidemiological studies on tt virus (ttv) were achieved in 44 japanese hd patients. ttv-dna was detected in 29.5% of hd patients, and the percentage was higher than that reported in normal populations. hbsag, anti-hbc, anti-hcv and hgv-rna were positive in 6.8%, 36.4%, 22.7% and 2.3%, respectively. one of three hd patients with ttv had liver disorders. in comparison between ttv positive and negative groups, there were significant differences of anti-hbc and total cholesterol val ... | 1999 | 10391009 |
| [detection of tt virus in hemodialysis patients]. | recently a newly discovered dna virus, transfusion transmitted virus (ttv), was introduced as a cause of post-transfusion hepatitis. we studied the frequency of ttv viremia in 60 hemodialysis patients in yamaguchi, japan. ttv dna was detected by heminested pcr, using primers described by okamoto et al. ttv dna was detected in 18 patients (30%). there was no differences in clinical characteristics, including age, gender, history of blood transfusion, and double infection of other hepatitis viruse ... | 1999 | 10391010 |
| [the prevalence of ttv infection and the route of ttv transmission in hemodialysis patients--compared with hcv infection]. | recently a novel virus named tt virus (ttv), associated with posttransfusion hepatitis, was isolated. the prevalence of ttv infection and the route of ttv transmission in hd units was investigated. ttv was detected in 51.3% of patients on hd (59/115), as compared with 16.5% of healthy blood donors (15/91). the prevalence rate of ttv in the patients without history of blood transfusion was similarly high (51.6%), compared with that of those with history of blood transfusion (51.2%). the prevalenc ... | 1999 | 10391011 |
| [detection rate of ttv-dna in healthy medical workers]. | we examined the positive rate in healthy medical workers about tt virus (ttv) which was a new hepatitis virus reported in 1997. the healthy medical workers showed a positive rate of 24%. because there was no significant difference of the positive rate between the medical workers and general healthy persons we could not conclude that the positive rate was influenced by their profession. generally it is known that a positive rate changes according to pcr primers used for the measurement. as for tt ... | 1999 | 10391012 |
| [genoepidemiology and pathogenicity of tt virus in japanese men with history of intravenous drug abuse and tattoo]. | blood contamination has been proposed as ttv transmission. we studied the genoprevalence of ttv in japanese men with history of intravenous drug abuse and/or tattoo. ttv was identified in serum by a polymerase chain reaction. ttv was detected in 89.7 percent of the men with history of intravenous drug abuse and/or tattoo, 74.4 percent of chronic hepatitis c patients, 78.0 percent of the chronic hepatitis b, and 65.8 percent of chronic hepatitis nonb nonc patients. serum alt levels of those infec ... | 1999 | 10391013 |
| [tt virus (ttv) in japanese haemophiliacs]. | this study aimed to evaluate the prevalence and characteristics of infection with a novel virus designated tt virus (ttv) in japanese haemophiliacs. ttv dna was measured in 60 haemophiliacs by semi-nested pcr. hcv rna, hgv rna and hiv antibody were also tested. ttv dna was detected in 35 haemophiliacs (58.3%). there were no differences in the backgrounds or characteristics between ttv dna-positive and-negative haemophiliacs, except that levels of igg and igm in ttv dna-positive patients were hig ... | 1999 | 10391014 |
| high prevalence and phylogenetic analysis of tt-virus infection in mongolia. | a novel dna virus, tt-virus (ttv), was isolated from a post-transfusion hepatitis patient in japan. the prevalence of ttv infection was investigated among patients with chronic liver disease and normal alanine aminotransferase (alt) volunteers as controls in mongolia. polymerase chain reaction (pcr) was employed to detect ttv dna using specific primers derived from open reading frame 1 (orf1) of the ttv genome. nucleotide sequences of samples positive for ttv dna were determined. the sequences w ... | 1999 | 10392725 |
| complete circular dna genome of a tt virus variant (isolate name sanban) and 44 partial orf2 sequences implicating a great degree of diversity beyond genotypes. | information on the entire genome of tt virus (ttv) has been scarce. the circular ssdna genome of a variant (isolate name sanban) that we sequenced was only 56.7% homologous to the prototype isolate (ta278), with even lower homology at the amino acid level: 34.2% for orf1 and 39.7% for orf2. regarding the orf1, sanban was only very distantly related to the six major ttv genotypes reported to date. in partial orf2 sequences determined on 44 isolates taken together, ttv has a broad range of genetic ... | 1999 | 10405352 |
| tt virus infection in french hemodialysis patients: study of prevalence and risk factors. | the tt virus (ttv) is a recently discovered dna virus which was first identified in patients with non-a to -g hepatitis following blood transfusion. in this study, we tested 150 attendees of two hemodialysis (hd) units of the public hospitals of marseilles, france, for the presence of ttv genome by using a pcr-based methodology. the overall prevalence of ttv viremia was 28% (compared to 5.3% in blood donors from the same region). we demonstrated the existence of chronic infections and superinfec ... | 1999 | 10405397 |
| tt virus infection is widespread in the general populations from different geographic regions. | by pcr screening, we found an extremely high prevalence of tt virus (ttv) in the general populations from different geographic regions. this suggests that ttv may be a common dna virus with no clear disease association in humans. ttv genotyping by phylogenetic analysis was also performed. | 1999 | 10405426 |
| infection with a novel human dna virus (ttv) has no pathogenic significance in patients with liver diseases. | a recently identified dna virus, termed tt virus (ttv), has been associated with post-transfusional hepatitis, and a high prevalence of ttv infection in patients with acute or chronic liver disease of unknown etiology has been reported from japan, but few data are available about ttv infection in other countries. | 1999 | 10406180 |
| the hepatitis alphabet--hepatitis a-g and ttv. | during the past three decades the number of viruses known to be capable to inducing liver inflammation has been considerably expanded. this short review gives a quick overview of the virologic characteristics, clinical manifestations, diagnosis, and treatment options. newer hepatitis viruses such as hepatitis e virus (hev), hepatitis gb-virus c/hepatitis g virus (gbv-c/hgv), and transfusion-transmitted virus (ttv) are discussed and data concerning their disease-inducing capacity reviewed. | 1999 | 10420504 |
| analyses of tt virus full-length genomic sequences. | since the identification of tt virus, only one full-length and two near full-length sequences representing a single subtype of the virus have been reported. in order to understand further the nature of the tt virus genome, nine of the most divergent tt virus sequences have been extended to full-length or near full-length. phylogenetic analysis demonstrated that these sequences represent three distinct tt virus genotypes and two subtypes. a high degree of nucleotide sequence variability (approxim ... | 1999 | 10423143 |
| sequence diversity of tt virus in geographically dispersed human populations. | tt virus (ttv) is a newly discovered dna virus originally classified as a member of the parvoviridae. ttv is transmitted by blood transfusion where it has been reported to be associated with mild post-transfusion hepatitis. ttv can cause persistent infection, and is widely distributed geographically; we recently reported extremely high prevalences of viraemia in individuals living in tropical countries (e.g. 74% in papua new guinea, 83% in gambia; prescott & simmonds, new england journal of medi ... | 1999 | 10423144 |
| tt virus sequence heterogeneity in vivo: evidence for co-infection with multiple genetic types. | tt virus (ttv) is a newly described dna virus of humans that exhibits an unusually high degree of genetic heterogeneity. we have performed extensive analysis of the ttv populations present in samples, taken over a period of 2 to 6 years, from three individuals with persistent ttv infection. ttv dna titres estimated for sequential samples were found to be quite stable over the entire study period in two patients, but fluctuated considerably in the third. dna sequence analysis revealed different g ... | 1999 | 10423145 |