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Makoto Mayumi - One of the best experts on this subject based on the ideXlab platform.
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effect of interferon on a nonenveloped DNA Virus tt Virus associated with acute and chronic hepatitis of unknown etiology
Journal of Medical Virology, 1999Co-Authors: Yoshihiro Akahane, Hiroaki Okamoto, Yuzo Miyakawa, Masato Ukita, Minoru Sakamoto, Yoshiki Miyazaki, Shunichi Okada, Taisuke Inoue, Makoto MayumiAbstract:An unenveloped DNA Virus named TT Virus (TTV) has been reported in association with acute and chronic hepatitis of unknown etiology. The effect of interferon on TTV was evaluated in the patients with chronic hepatitis C who were coinfected with TTV. TTV DNA was determined by a polymerase chain reaction with heminested primers in the 96 patients with chronic hepatitis C who received interferon-α (516 million units in 26 weeks) and followed for 24 months thereafter. TTV DNA was detected in 31 (32%) patients before therapy. TTV DNA became undetectable during interferon therapy and remained absent in 14 (45% of the 31 patients) through 24 months thereafter. The four patients with pretreatment TTV DNA titer ≥103/ml did not respond. These results indicate that TTV is sensitive to interferon, and the response would be inversely correlated with pretreatment viral titers. J. Med. Virol. 58:196–200, 1999. © 1999 Wiley-Liss, Inc.
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excretion into bile of a novel unenveloped DNA Virus tt Virus associated with acute and chronic non a g hepatitis
The Journal of Infectious Diseases, 1999Co-Authors: Masato Ukita, Hiroaki Okamoto, Naomi Kato, Y Miyakawa, Makoto MayumiAbstract: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 1 of the 2 patients tested. The buoyant density of TTV in bile from 1 tested patient (1.33‐1.35 g/cm 3 ) was the same as that in feces (1.32‐1.35 g/cm 3 ). TTV may be secreted via bile into feces in a transmissible form and would spread by a fecal-oral route for deep and wide penetration into the general population. Recently, an unenveloped, single-stranded DNA Virus was recovered by representational difference analysis from a patient with posttransfusion non-A‐G hepatitis and was named TT Virus (TTV) after the initials of the index case [1, 2]. TTV DNA was detected by polymerase chain reaction (PCR) with heminested primers in 3 of 5 tested patients with posttransfusion hepatitis, including the index case, in titers in parallel with elevated alanine aminotransferase (ALT) levels [1]. Posttransfusion hepatitis of non-A‐G etiology was contracted significantly more frequently by the recipients who developed TTV viremia than by those who did not (4/18 [22%] vs. 0/19 [0%], ) [3]. TTV DNA was detected frequently in patients with P ! .05 fulminant hepatitis (9/19 [47%]) and in those with chronic liver disease (41/90 [46%]) of non-A‐G etiology more frequently than in healthy blood donors (34/290 [12%]) in Japan [2]. The exact hepatitis-inducing capacity of TTV, however, needs to be evaluated in additional studies. TTV is transmitted parenterally by contaminated blood, since it occurs frequently in the population at risk for bloodborne Viruses, such as hemophiliacs (19/28 [68%]), hemodialysis patients (26/57 [46%]), and intravenous drug users (14/35 [40%]) [2]. If TTV replicates in the liver, as suggested by Virus titers 10‐100 times higher than in corresponding serum in some patients with chronic non-A‐G hepatitis [2], it would be secreted into bile and then shed into feces. Fecal excretion of TTV DNA supports this view [4]. Being nonenveloped, excreted TTV
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distinct genotypes of a nonenveloped DNA Virus associated with posttransfusion non a to g hepatitis tt Virus in plasma and peripheral blood mononuclear cells
Journal of Medical Virology, 1999Co-Authors: Hiroaki Okamoto, Yuzo Miyakawa, Naomi Kato, Hisao Iizuka, Fumio Tsuda, Makoto MayumiAbstract: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 -each from PBMC from eight individuals selected at random from this group. TTV can be classified into genotypes separated by an evolutionary distance > 0.30, which can be divided further into subtypes separated by that of 0.15. Three individuals possessed two different TTV variants of distinct genotypes, with predominant genotypes different between plasma and PBMC. Another possessed TTV of the same genotype in both the plasma and PBMC, but clones with a subtype not seen in plasma were observed in PBMC. A third individual had TTV variants with or without a deletion mutation, and those with the deletion mutation abounded only in PBMC. The remaining three individuals were infected with TTV with the same sequence both in plasma and PBMC. These results indicate that TTV variants with phylogenetic differences could infect the same individual, and that some variants would have a predilection for PBMC. It remains to be seen, however, if TTV replicates in PBMC or whether it has been sequestered before its evolution in the host.
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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
Journal of Hepatology, 1999Co-Authors: Hiroki Ikeda, Hiroaki Okamoto, Yuzo Miyakawa, Masashi Takasu, Kyoichi Inoue, Makoto MayumiAbstract:Abstract Background/Aims: 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. Methods: TTV DNA was determined by polymerase chain reaction with hemi-nested primers in 64 patients with acute or chronic liver disease of unknown etiology and in 100 with acute or chronic liver disease positive for antibody to hepatitis C Virus (HCV) as well as HCV RNA. Results: TTV DNA was detected in two of the seven (29%) patients with acute hepatitis of unknown etiology, but in none of the four patients with acute HCV-associated hepatitis. It was detected in 27 of the 57 (47%) patients with chronic liver disease of unknown etiology at a frequency significantly higher ( p Conclusions: Based on the obtained results, TTV has a role in the development of acute and chronic liver disease of unknown etiology.
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infection with an unenveloped DNA Virus ttv associated with posttransfusion non a to g hepatitis in hepatitis patients and healthy blood donors in thailand
Journal of Medical Virology, 1998Co-Authors: Hiroto Tanaka, Hiroaki Okamoto, Yuzo Miyakawa, Fumio Tsuda, Pairoj Luengrojanakul, Termchai Chainuvati, Takeshi Tanaka, Makoto MayumiAbstract: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%) of the 59 patients with HBsAg (P < 0.05) or in 38 (36%) of the 105 blood donors (P< 0.05). Among patients with chronic liver disease, TTV DNA occurred in those with liver cirrhosis and hepatocellular carcinoma more frequently than in those with chronic hepatitis (35 of 65 or 54% vs. 20 of 62 or 32%, P< 0.05). There were no differences in age, sex, or markers of infection with hepatitis B, C and GBV-C/HGV Viruses, indicating a mode of transmission of TTV different from those of the other hepatitis Viruses. Phylogenetic analysis indicated three different genotypes of TTV with six distinct subtypes in Thailand. Based on these results, TTV would have a role in the development of chronic liver disease of unknown etiology in Thailand.
Hiroaki Okamoto - One of the best experts on this subject based on the ideXlab platform.
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effect of interferon on a nonenveloped DNA Virus tt Virus associated with acute and chronic hepatitis of unknown etiology
Journal of Medical Virology, 1999Co-Authors: Yoshihiro Akahane, Hiroaki Okamoto, Yuzo Miyakawa, Masato Ukita, Minoru Sakamoto, Yoshiki Miyazaki, Shunichi Okada, Taisuke Inoue, Makoto MayumiAbstract:An unenveloped DNA Virus named TT Virus (TTV) has been reported in association with acute and chronic hepatitis of unknown etiology. The effect of interferon on TTV was evaluated in the patients with chronic hepatitis C who were coinfected with TTV. TTV DNA was determined by a polymerase chain reaction with heminested primers in the 96 patients with chronic hepatitis C who received interferon-α (516 million units in 26 weeks) and followed for 24 months thereafter. TTV DNA was detected in 31 (32%) patients before therapy. TTV DNA became undetectable during interferon therapy and remained absent in 14 (45% of the 31 patients) through 24 months thereafter. The four patients with pretreatment TTV DNA titer ≥103/ml did not respond. These results indicate that TTV is sensitive to interferon, and the response would be inversely correlated with pretreatment viral titers. J. Med. Virol. 58:196–200, 1999. © 1999 Wiley-Liss, Inc.
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molecular virology of tt Virus
Nihon rinsho. Japanese journal of clinical medicine, 1999Co-Authors: Hiroaki OkamotoAbstract: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 > 0.30. Nucleotide sequence of the noncoding region is conserved, whereas the coding region sequence is highly variable. TTV strains with extremely high sequence divergence prevail in infected individuals. An association of TTV genotypes, detectable by PCR with N22 primers or genotype 1-specific primers, with hepatitis of unknown etiology suggest that TTV of restricted genotypes would be clinically important.
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excretion into bile of a novel unenveloped DNA Virus tt Virus associated with acute and chronic non a g hepatitis
The Journal of Infectious Diseases, 1999Co-Authors: Masato Ukita, Hiroaki Okamoto, Naomi Kato, Y Miyakawa, Makoto MayumiAbstract: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 1 of the 2 patients tested. The buoyant density of TTV in bile from 1 tested patient (1.33‐1.35 g/cm 3 ) was the same as that in feces (1.32‐1.35 g/cm 3 ). TTV may be secreted via bile into feces in a transmissible form and would spread by a fecal-oral route for deep and wide penetration into the general population. Recently, an unenveloped, single-stranded DNA Virus was recovered by representational difference analysis from a patient with posttransfusion non-A‐G hepatitis and was named TT Virus (TTV) after the initials of the index case [1, 2]. TTV DNA was detected by polymerase chain reaction (PCR) with heminested primers in 3 of 5 tested patients with posttransfusion hepatitis, including the index case, in titers in parallel with elevated alanine aminotransferase (ALT) levels [1]. Posttransfusion hepatitis of non-A‐G etiology was contracted significantly more frequently by the recipients who developed TTV viremia than by those who did not (4/18 [22%] vs. 0/19 [0%], ) [3]. TTV DNA was detected frequently in patients with P ! .05 fulminant hepatitis (9/19 [47%]) and in those with chronic liver disease (41/90 [46%]) of non-A‐G etiology more frequently than in healthy blood donors (34/290 [12%]) in Japan [2]. The exact hepatitis-inducing capacity of TTV, however, needs to be evaluated in additional studies. TTV is transmitted parenterally by contaminated blood, since it occurs frequently in the population at risk for bloodborne Viruses, such as hemophiliacs (19/28 [68%]), hemodialysis patients (26/57 [46%]), and intravenous drug users (14/35 [40%]) [2]. If TTV replicates in the liver, as suggested by Virus titers 10‐100 times higher than in corresponding serum in some patients with chronic non-A‐G hepatitis [2], it would be secreted into bile and then shed into feces. Fecal excretion of TTV DNA supports this view [4]. Being nonenveloped, excreted TTV
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distinct genotypes of a nonenveloped DNA Virus associated with posttransfusion non a to g hepatitis tt Virus in plasma and peripheral blood mononuclear cells
Journal of Medical Virology, 1999Co-Authors: Hiroaki Okamoto, Yuzo Miyakawa, Naomi Kato, Hisao Iizuka, Fumio Tsuda, Makoto MayumiAbstract: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 -each from PBMC from eight individuals selected at random from this group. TTV can be classified into genotypes separated by an evolutionary distance > 0.30, which can be divided further into subtypes separated by that of 0.15. Three individuals possessed two different TTV variants of distinct genotypes, with predominant genotypes different between plasma and PBMC. Another possessed TTV of the same genotype in both the plasma and PBMC, but clones with a subtype not seen in plasma were observed in PBMC. A third individual had TTV variants with or without a deletion mutation, and those with the deletion mutation abounded only in PBMC. The remaining three individuals were infected with TTV with the same sequence both in plasma and PBMC. These results indicate that TTV variants with phylogenetic differences could infect the same individual, and that some variants would have a predilection for PBMC. It remains to be seen, however, if TTV replicates in PBMC or whether it has been sequestered before its evolution in the host.
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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
Journal of Hepatology, 1999Co-Authors: Hiroki Ikeda, Hiroaki Okamoto, Yuzo Miyakawa, Masashi Takasu, Kyoichi Inoue, Makoto MayumiAbstract:Abstract Background/Aims: 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. Methods: TTV DNA was determined by polymerase chain reaction with hemi-nested primers in 64 patients with acute or chronic liver disease of unknown etiology and in 100 with acute or chronic liver disease positive for antibody to hepatitis C Virus (HCV) as well as HCV RNA. Results: TTV DNA was detected in two of the seven (29%) patients with acute hepatitis of unknown etiology, but in none of the four patients with acute HCV-associated hepatitis. It was detected in 27 of the 57 (47%) patients with chronic liver disease of unknown etiology at a frequency significantly higher ( p Conclusions: Based on the obtained results, TTV has a role in the development of acute and chronic liver disease of unknown etiology.
Arvind Varsani - One of the best experts on this subject based on the ideXlab platform.
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Discovery of a novel circular DNA Virus in the Forbes sea star, Asterias forbesi
Archives of Virology, 2015Co-Authors: Elizabeth Fahsbender, Arvind Varsani, Karyna Rosario, Ian Hewson, Allison D. Tuttle, Mya BreitbartAbstract:A single-stranded DNA (ssDNA) Virus, Asterias forbesi-associated circular Virus (AfaCV), was discovered in a Forbes sea star displaying symptoms of sea star wasting disease (SSWD). The AfaCV genome organization is typical of circular Rep-encoding ssDNA (CRESS-DNA) Viruses and is similar to that of members of the family Circoviridae. PCR-based surveys indicate that AfaCV is not clearly associated with SSWD, whereas the sea star-associated densoVirus (SSaDV), recently implicated in SSWD in the Pacific, was prevalent in symptomatic specimens. AfaCV represents the first CRESS-DNA Virus detected in echinoderms, adding to the growing diversity of these Viruses recently recovered from invertebrates.
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Characterisation of a diverse range of circular replication-associated protein encoding DNA Viruses recovered from a sewage treatment oxidation pond
Infection Genetics and Evolution, 2015Co-Authors: Simona Kraberger, Gerardo R. Argüello-astorga, Laurence G. Greenfield, Craig Galilee, Darren P. Martin, Arvind VarsaniAbstract:Our knowledge of circular replication-associated protein encoding single-stranded (CRESS) DNA Virus diversity has increased dramatically in recent years, largely due to advances in high-throughput sequencing technologies. These Viruses are apparently major virome components in most terrestrial and aquatic environments and it is therefore of interest to determine their diversity at the interfaces between these environments. Treated sewage water is a particularly interesting interface between terrestrial and aquatic viromes in that it is directly pumped into waterways and is likely to contain Virus populations that have been strongly impacted by humans. We used a combination of high-throughput sequencing, full genome PCR amplification, cloning and Sanger sequencing to investigate the diversity of CRESS DNA Viruses present in a sewage oxidation pond. Using this approach, we recovered 50 putatively complete novel CRESS viral genomes (it remains possible that some are components of multipartite viral genomes) and 11 putatively sub-genome-length circular DNA molecules which may be either defective genomes or components of multipartite genomes. Thirteen of the genomes have bidirectional genome organisations and share similar conserved replication-associated protein (Rep) motifs to those of the gemycircularViruses: a group that in turn is most closely related to the geminiViruses. The remaining 37 viral genomes share very low degrees of Rep similarity to those of all other known CRESS DNA Viruses. This number of highly divergent CRESS DNA Virus genomes within a single sewage treatment pond further reinforces the notion that there likely exist hundreds of completely unknown genus/family level CRESS DNA Virus groupings.
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Identification and molecular characterization of a single-stranded circular DNA Virus with similarities to Sclerotinia sclerotiorum hypovirulence-associated DNA Virus 1
Archives of Virology, 2013Co-Authors: Tang Yafei, Arvind Varsani, Songbai Zhang, She Xiaoman, Lan Guobing, He ZifuAbstract:A putative circular single-stranded DNA (ssDNA) Virus was recovered from Hypericum japonicum collected in Vietnam. The viral isolate was tentatively named Hypericum japonicum-associated circular DNA Virus (HJasCV). HJasCV shares 58.7-65.4% nucleotide sequence identity with Sclerotinia sclerotiorum hypovirulence-associated DNA Virus 1 (SsHADV-1) and SsHADV-1-like Viruses. Like this group of Viruses, the genome of HJasCV (2 200 nt) has two large ORFs, one in the virion-sense and the other in the complementary-sense DNA. The proteins encoded in the virion-sense and complementary-sense ORFs share 39-46 % and 45-67 % amino acid sequence identity with the putative capsid and replication-associated proteins (Reps), respectively, of SsHADV-1 and SsHADV-1-like Viruses. The putative Rep of HJasCV contains all of the motifs related to rolling-circle replication. Its 111-bp intergenic region (IR) contains a hairpin structure with a geminiVirus-like nonanucleotide sequence, TAATGTTAT, at the apex of the loop. Phylogenetic analysis revealed that HJasCV forms a monophyletic clade with SsHADV-1 and SsHADV-1-like Viruses.
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identification of a novel circular DNA Virus in new zealand fur seal arctocephalus forsteri fecal matter
Genome Announcements, 2013Co-Authors: Alyssa Sikorski, Anisha Dayaram, Arvind VarsaniAbstract:ABSTRACT Fur seal feces-associated circular DNA Virus (FSfaCV) is a novel Virus isolated from the fecal matter of New Zealand fur seals. FSfaCV has two main open reading frames in its 2,925-nucleotide (nt) genome. The replication-associated protein (Rep) of FSfaCV has similarity to Rep-like sequences in the Giardia intestinalis genome.
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Discovery of Sclerotinia sclerotiorum Hypovirulence-Associated Virus-1 in Urban River Sediments of Heathcote and Styx Rivers in Christchurch City, New Zealand
Genome Announcements, 2013Co-Authors: Simona Kraberger, Anisha Dayaram, Peyman Zawar-reza, Christopher Gomez, Jon S Harding, Daisy Stainton, Arvind VarsaniAbstract:ABSTRACT In samples of benthic and bank river sediments of two urban rivers in Christchurch city (New Zealand), we identified and recovered isolates of Sclerotinia sclerotiorum hypovirulence-associated Virus-1 (SsHADV-1), a fungus-infecting circular single-stranded DNA Virus. This is the first report of SsHADV-1 outside of China and in environmental samples.
Yuzo Miyakawa - One of the best experts on this subject based on the ideXlab platform.
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effect of interferon on a nonenveloped DNA Virus tt Virus associated with acute and chronic hepatitis of unknown etiology
Journal of Medical Virology, 1999Co-Authors: Yoshihiro Akahane, Hiroaki Okamoto, Yuzo Miyakawa, Masato Ukita, Minoru Sakamoto, Yoshiki Miyazaki, Shunichi Okada, Taisuke Inoue, Makoto MayumiAbstract:An unenveloped DNA Virus named TT Virus (TTV) has been reported in association with acute and chronic hepatitis of unknown etiology. The effect of interferon on TTV was evaluated in the patients with chronic hepatitis C who were coinfected with TTV. TTV DNA was determined by a polymerase chain reaction with heminested primers in the 96 patients with chronic hepatitis C who received interferon-α (516 million units in 26 weeks) and followed for 24 months thereafter. TTV DNA was detected in 31 (32%) patients before therapy. TTV DNA became undetectable during interferon therapy and remained absent in 14 (45% of the 31 patients) through 24 months thereafter. The four patients with pretreatment TTV DNA titer ≥103/ml did not respond. These results indicate that TTV is sensitive to interferon, and the response would be inversely correlated with pretreatment viral titers. J. Med. Virol. 58:196–200, 1999. © 1999 Wiley-Liss, Inc.
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distinct genotypes of a nonenveloped DNA Virus associated with posttransfusion non a to g hepatitis tt Virus in plasma and peripheral blood mononuclear cells
Journal of Medical Virology, 1999Co-Authors: Hiroaki Okamoto, Yuzo Miyakawa, Naomi Kato, Hisao Iizuka, Fumio Tsuda, Makoto MayumiAbstract: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 -each from PBMC from eight individuals selected at random from this group. TTV can be classified into genotypes separated by an evolutionary distance > 0.30, which can be divided further into subtypes separated by that of 0.15. Three individuals possessed two different TTV variants of distinct genotypes, with predominant genotypes different between plasma and PBMC. Another possessed TTV of the same genotype in both the plasma and PBMC, but clones with a subtype not seen in plasma were observed in PBMC. A third individual had TTV variants with or without a deletion mutation, and those with the deletion mutation abounded only in PBMC. The remaining three individuals were infected with TTV with the same sequence both in plasma and PBMC. These results indicate that TTV variants with phylogenetic differences could infect the same individual, and that some variants would have a predilection for PBMC. It remains to be seen, however, if TTV replicates in PBMC or whether it has been sequestered before its evolution in the host.
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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
Journal of Hepatology, 1999Co-Authors: Hiroki Ikeda, Hiroaki Okamoto, Yuzo Miyakawa, Masashi Takasu, Kyoichi Inoue, Makoto MayumiAbstract:Abstract Background/Aims: 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. Methods: TTV DNA was determined by polymerase chain reaction with hemi-nested primers in 64 patients with acute or chronic liver disease of unknown etiology and in 100 with acute or chronic liver disease positive for antibody to hepatitis C Virus (HCV) as well as HCV RNA. Results: TTV DNA was detected in two of the seven (29%) patients with acute hepatitis of unknown etiology, but in none of the four patients with acute HCV-associated hepatitis. It was detected in 27 of the 57 (47%) patients with chronic liver disease of unknown etiology at a frequency significantly higher ( p Conclusions: Based on the obtained results, TTV has a role in the development of acute and chronic liver disease of unknown etiology.
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infection with an unenveloped DNA Virus ttv associated with posttransfusion non a to g hepatitis in hepatitis patients and healthy blood donors in thailand
Journal of Medical Virology, 1998Co-Authors: Hiroto Tanaka, Hiroaki Okamoto, Yuzo Miyakawa, Fumio Tsuda, Pairoj Luengrojanakul, Termchai Chainuvati, Takeshi Tanaka, Makoto MayumiAbstract: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%) of the 59 patients with HBsAg (P < 0.05) or in 38 (36%) of the 105 blood donors (P< 0.05). Among patients with chronic liver disease, TTV DNA occurred in those with liver cirrhosis and hepatocellular carcinoma more frequently than in those with chronic hepatitis (35 of 65 or 54% vs. 20 of 62 or 32%, P< 0.05). There were no differences in age, sex, or markers of infection with hepatitis B, C and GBV-C/HGV Viruses, indicating a mode of transmission of TTV different from those of the other hepatitis Viruses. Phylogenetic analysis indicated three different genotypes of TTV with six distinct subtypes in Thailand. Based on these results, TTV would have a role in the development of chronic liver disease of unknown etiology in Thailand.
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fecal excretion of a nonenveloped DNA Virus ttv associated with posttransfusion non a g hepatitis
Journal of Medical Virology, 1998Co-Authors: Hiroaki Okamoto, Yuzo Miyakawa, Masato Ukita, Yoshihiro Akahane, Masako Fukuda, Fumio Tsuda, Makoto MayumiAbstract: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. When feces and serum from one patient were subjected to floatation ultracentrifugation in CsCl, TTV in feces banded at a peak density of 1.35 g/cm3 and that in serum at 1.31-1.32 g/cm3. TTV isolates in three pairs of feces and serum had the identical sequence of 222 base pairs. The excretion of TTV into feces indicates that TTV would be transmitted not only parenterally but also nonparenterally by a fecal-oral route.
R. W. Mwangi - One of the best experts on this subject based on the ideXlab platform.
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The Effects of a Tsetse DNA Virus Infection on the Functions of the Male Accessory Reproductive Gland in the Host Fly Glossina morsitans centralis (Diptera; Glossinidae)
Current microbiology, 1999Co-Authors: Rosemary Sang, Walter G. Z. O. Jura, R. W. Mwangi, Peter OgajaAbstract:Freshly deposited third instar Glossina morsitans centralis larvae were infected with the tsetse DNA Virus by microinjection, and at emergence adult males were separated from the females and fed on rabbit blood every second day for 8 days. A control group treated with sterile saline were handled similarly. They were dissected, and comparative observations made on the appearance and size of the accessory reproductive glands (ARG) in infected and control males. Regularly fed 8-day-old males from infected and control groups were mated to 2-day-old normal females obtained from the insectay. After separation from copula, the females were dissected and the uteri examined for the presence and quality of the spermatophore. The spermathecae were also examined for insemination. ARG tissues from the control and Virus infected regularly fed 8-day-old male flies were fixed and processed for electron microscopic studies.
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The Effects of a DNA Virus Infection on the Reproductive Potential of Female Tsetse Flies, Glossina morsitans centralis and Glossina morsitans morsitans (Diptera: Glossinidae)
Memorias do Instituto Oswaldo Cruz, 1998Co-Authors: Rosemary Sang, L. H. Otieno, Walter G. Z. O. Jura, R. W. MwangiAbstract:Reproductive anomalies associated with the tsetse DNA Virus infection in the female tsetse hosts, Glossina morsitans centralis Machado and Glossina morsitans morsitans Westwood, inoculated with the Virus during the 3rd instar larval stage were studied and the data compared to those obtained from the control females injected with sterile physiological saline. Virus infected flies had significantly longer first and second pregnancy cycles (P < 0.0001) and produced pupae that were of significantly less weight in milligrams (P < 0.0001) compared to controls. Transmission of the Virus to progeny was not absolute and only 21% of G. m. centralis and 48% of G. m. morsitans first progeny flies from infected females developed salivary gland hypertrophy as a result of transmission from mother to progeny. The Virus infected females produced significantly fewere pupae compared to the controls during the experimental period (P < 0.00001).
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Effects of Tsetse DNA Virus Infection on the Survival of a Host Fly,Glossina morsitans centralis(Diptera; Glossinidae)
Journal of Invertebrate Pathology, 1997Co-Authors: Rosemary Sang, Walter G. Z. O. Jura, Peter M. Tukei, R. W. MwangiAbstract:Freshly deposited third instarGlossina morsitans centralislarvae were infected with the tsetse DNA Virus by microinjection. At emergence comparative observations were made on longevity and feeding behavior of infected and control flies. Gut tissues from the control and Virus-infected flies were fixed and processed for light and electron microscopy. The longevity of infected flies was significantly reduced compared to that of the controls (P < 0.05). The main mortality factors in the Virus-infected flies with severe lesions in the salivary glands were starvation due to failure to feed and clotting of blood in and/or rupture of the crop. Rupture of the midgut also caused some mortalities. Infected flies probed significantly more times during feeding to repletion (P < 0.05) and took significantly longer to feed compared to the control flies (P < 0.05). Infected flies which fed took significantly less blood compared to the controls (P < 0.05). Histological studies revealed pathological changes in the epithelial cells of the anterior midgut secretory midgut and the posterior midgut. There was severe disintegration of the membranous organelles, especially the mitochondria and rough endoplasmic reticulum, leading to extensive vacuolation in such epithelial cells. No viral particles were observed in the secretory and posterior midgut. Virions were observed in the anterior midgut lumen and occasional particles were seen invading the epithelial cells in this area of the midgut, especially in heavily infected flies.