Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Tomofumi Nakayoshi is active.

Publication


Featured researches published by Tomofumi Nakayoshi.


Journal of Medical Virology | 1999

Hepatitis delta virus genotype IIb predominates in an endemic area, Okinawa, Japan.

Hiroshi Sakugawa; Hiroki Nakasone; Tomofumi Nakayoshi; Yuko Kawakami; Shiro Miyazato; Fukunori Kinjo; Atsushi Saito; Shao-Ping Ma; Hak Hotta; Moritoshi Kinoshita

Hepatitis delta virus (HDV) infection is relatively common in the Miyako Islands, Okinawa, Japan, where the infection has been reported to be associated with low pathogenicity. HDV RNA extracted from each of 6 patients with HDV‐related chronic liver disease living in the islands was amplified by reverse transcription‐polymerase chain reaction and examined genetically to determine the HDV genotype. All isolates from the 6 patients were classified as genotype II by the neighbor‐joining method. However, these isolates had relatively low homology (75–81%) to the HDV genotype II isolate reported from Japan, and showed relatively high identity (83–95%) to the novel genotype II isolate (HDV genotype IIb) recently reported from Taiwan. Phylogenetic analysis showed that the 6 isolates form a novel group within HDV genotype II. Furthermore, there was notable variation in sequence among the 6 isolates compared with the relatively close clustering of HDV isolates within limited areas (e.g., United States, Archangelos, Turkey, Albania, Peru). HDV genotype II in the Miyako Islands is therefore unique, and HDV infection may have been introduced at a relatively early time in this area. J. Med. Virol. 58:366–372, 1999.


Hepatology Research | 2001

Correlation between serum transaminase activity and virus load among patients with chronic liver disease type B

Hiroshi Sakugawa; Hiroki Nakasone; Tomofumi Nakayoshi; Yuko Kawakami; Tsuyoshi Yamashiro; Tatsuji Maeshiro; Fukunori Kinjo; Atsushi Saito

Newly developed hepatitis B virus (HBV)-DNA quantitative assays, transcription-mediated amplification and hybridization protection assay (TMA-HPA) and branched-DNA assay were clinically evaluated. The subjects consisted of 160 chronic HBV carriers; 48 were hepatitis Be antigen (HBeAg)-positive, whereas 109 were anti-HBe-positive (three were both negative). All subjects with HBeAg, except one, showed high HBV-DNA replication levels (>/=10(5.8) copies/ml). In HBeAg negative subjects, there was a strong correlation between the serum HBV-DNA and alanine aminotransferase (ALT) levels; ALT level was usually normal if the samples tested showed an HBV-DNA level less than 10(5)/ml, whereas, the majority of the sera with an HBV-DNA concentration greater than 10(7)copies/ml showed elevation in serum ALT level. An intermediate range of HBV-DNA level (10(5)-10(7) copies/ml) was associated with variable ALT activity. In conclusion, a serum HBV-DNA level associated with ALT elevation was lower in patients with type B chronic liver disease negative for HBeAg compared with their HBeAg-positive counterparts. There was usually no or mild liver disease activity when patients with chronic HBV infection have serum HBV-DNA levels less than 10(5)copies/ml.


Journal of Gastroenterology and Hepatology | 1997

Seroepidemiological study on hepatitis delta virus infection in the Irabu Islands, Okinawa, Japan

Hiroshi Sakugawa; Hiroki Nakasone; Hayashi Shokita; Yuko Kawakami; Noriya Nakachi; Hiroshi Adaniya; Takuji Mizushima; Tomofumi Nakayoshi; Fukunori Kinjo; Atsushi Saito; Masaaki Taira; Hitoshi Takaesu; Naokiyo Onga

A seroepidemiological study was performed to clarify the prevalence of hepatitis delta virus (HDV) infection among the general population in the Irabu islands, Okinawa, Japan. Of 2028 healthy people examined who had received their annual health check‐up in 1994–95, 195 (9.6%) were positive for hepatitis B surface antigen (HBsAg). Of these 195 HBsAg‐positive individuals, 46 (23.6%) showed a positive reaction for antibody to HDV (anti‐HDV). The positivity rate of anti‐HDV among HBsAg‐positive subjects tended to increase with age up to 50–59 years of age. The prevalence of anti‐HDV also varied among the seven districts in the islands (0–63.3%). None of the anti‐HDV‐positive subjects was included in the high risk group for parenterally transmitted diseases. The unusually high prevalence of anti‐HDV among HBsAg‐positive individuals, particularly in the older age groups, seemed to reflect the natural prevalence or previous HDV infection, rather than a current or imported infection of HDV. Although the great majority of HBsAg‐positive subjects with anti‐HDV were asymptomatic, abnormally high values of serum transaminases were more frequently seen in these subjects compared with HBsAg‐positive subjects without anti‐HDV.


Journal of Gastroenterology | 2000

A patient with primary biliary cirrhosis associated with autoimmune hemolytic anemia.

Hiroki Nakasone; Hiroshi Sakugawa; Jun Fukuchi; Tsuyoshi Miyagi; Richiko Sugama; Akira Hokama; Tomofumi Nakayoshi; Yuko Kawakami; Tsuyoshi Yamashiro; Fukunori Kinjo; Atsushi Saito; Naoya Taira; Takayoshi Toda; Ichiro Kan

Abstract: Primary biliary cirrhosis is often associated with autoimmune conditions, such as thyroid disease, sicca complex, and rheumatoid arthritis. However, an association with autoimmune hemolytic anemia has rarely been reported. We present a case of primary biliary cirrhosis associated with warm type autoimmune hemolytic anemia, and we review prior reports.


Journal of Gastroenterology | 1998

Prevalence and clinical features of hepatitis delta virus infection in the Miyako Islands, Okinawa, Japan.

Hiroki Nakasone; Hiroshi Sakugawa; Hayashi Shokita; Tomofumi Nakayoshi; Yuko Kawakami; Fukunori Kinjo; Atsushi Saito; Masaki Shinjo; Hiroshi Adaniya; Takuji Mizushima; Masaaki Taira

Abstract: The aims of this study were twofold: (1) to determine the prevalence and clinical features of hepatitis delta virus (HDV) infection among subjects positive for hepatitis B surface antigen (HBsAg) living in the Miyako Islands, Okinawa Prefecture, Japan, and (2) to clarify the relationship between HDV-RNA level and severity of HDV-related liver disease. One hundred and ninety-nine HBsAg-positive subjects (123 asymptomatic carriers [ASCs], 3 patients with acute hepatitis [AH], 50 patients with chronic hepatitis [CH], 15 patients with liver cirrhosis [LC], and 8 patients with hepatocellular carcinoma [HCC], were tested for antrbody to HDV (anti-HDV) by radioimmunoassay. Anti-HDV-positive individuals were examined to determine semi-quantified HDV-RNA level by polymerase chain reaction (PCR). The overall prevalence of anti-HDV among the 199 subjects was 21.1%. The positivity rate tended to increase with age or the severity of the underlying liver disease: anti-HDV-positive rates were 10.6% (13/123) in ASCs, 32.0% (16/50) in patients with CH, 40.0% (6/15) in patients with LC, and 87.5% (7/8) in patients with HCC. None of the patients with AH were positive for anti-HDV. There was no correlation between semi-quantified serum HDV-RNA levels and the severity of chronic liver disease in patients positive for anti-HDV. The present study showed the local spread of HDV infection in the Miyako Islands, Okinawa, Japan. Although the anti-HDV positivity rate tended to increase with the severity of the underlying liver disease, the severity of HDV-related liver disease did not correlate with the semi-quantified serum HDV-RNA level.


Journal of Gastroenterology | 2002

A rare association of primary biliary cirrhosis and pernicious anemia

Hajime Aoyama; Hiroshi Sakugawa; Hiroki Nakasone; Tomofumi Nakayoshi; Akiko Kinjo; Maki Tamayose; Hajime Higa; Eriko Uema; Takayuki Chinen; Ryosaku Tomiyama; Nobufumi Uchima; Yukino Kugai; Fukunori Kinjo; Atsushi Saito; Mitsuru Kinjo

12 and the presence of anti-parietal cell antibody and anti-intrinsic factor antibody. Pernicious anemia should be regarded as a possible complication of primary biliary cirrhosis.


Hepatology Research | 2003

Monitoring low level hepatitis B virus by a newly developed sensitive test

Hiroshi Sakugawa; Kasen Kobashigawa; Tomofumi Nakayoshi; Tsuyoshi Yamashiro; Tatsuji Maeshiro; Ko Tomimori; Fukunori Kinjo; Atsushi Saito; Motokazu Mukaide

We have recently developed a sensitive quantitative test for hepatitis B virus (HBV) DNA using a real-time polymerase chain reaction (HBV RTD DIRECT), which can detect HBV DNA levels as low as 10(0.7) copies/ml. The aim of this study was to explore the significance of viremia changes below the detection limit of the other currently developed sensitive assays, transcription-mediated amplification and hybridization protection assay (TMA-HPA) and Amplicor HBV Monitor. The subjects consisted of 11 patients with chronic liver disease type B who showed undetectable test results of HBV DNA by TMA-HPA or Amplicor HBV Monitor during the observation period. A total of 150 serial serum samples were examined for viremia level by HBV RTD DIRECT: 139 were positive and 11 were negative. HBV RTD DIRECT could detect viremia in 72 of 78 serum samples negative for HBV DNA by TMA-HPA, or in 38 of 43 serum samples negative for HBV DNA by Amplicor HBV Monitor. The HBV DNA level was gradually increased from its lowest level before the spontaneous reactivation of hepatitis or the emergence of YMDD mutant during lamivudine treatment. However, such a phenomenon was not revealed by either TMA-HPA or the Amplicor HBV Monitor test.


Hepatology Research | 2003

Epidemiology of primary biliary cirrhosis among women with elevated γ-glutamyl transpeptidase levels in Okinawa, Japan

Hiroshi Sakugawa; Hiroki Nakasone; Tomofumi Nakayoshi; Tsuyoshi Yamashiro; Tatsuji Maeshiro; Kasen Kobashigawa; Fukunori Kinjo; Atsushi Saito; Hiroki Zukeran; Yasuni Nakanuma; Kazuo Ohba

We investigated the conditions among women who had an asymptomatic increase in serum gamma-glutamyl transpeptidase (gamma-GTP) levels, and the prevalence of primary biliary cirrhosis (PBC), in the general population. Among 4048 women who received their annual health check-up, 241 showed an elevated gamma-GTP level and were invited to participate in this study. Of the 241 women, 122 participated and were examined thoroughly, including for antimitochondrial antibody (AMA) and by using liver biopsy to make a clinical diagnosis. Six (4.9%) of the 122 women were AMA positive: five were diagnosed and one was suspected of having PBC. Another two women had the criteria of PBC despite being AMA negative. PBC was detected in 5.7% (95% confidence interval (CI), 1.6-9.9%) of asymptomatic women with raised gamma-GTP levels who were 6.0% of all 4048 women examined. The estimated prevalence of PBC in our area was 3400 per million women mainly over 40 years and 840 per million in the whole population. In 44% of women, the cause of chronic gamma-GTP elevation was unknown; they usually showed mild and non-specific histological change differing from their liver biochemical test results.


Microbiology and Immunology | 1998

Relation between Reactivity to the NS-4 Region Peptides of Hepatitis C Virus (HCV) and Clinical Features among Patients Infected with HCV Genotype 1b

Hiroshi Sakugawa; Hiroki Nakasone; Tomofumi Nakayoshi; Yuko Kawakami; Fukunori Kinjo; Atsushi Saito; Tomokuni Nakayoshi; Akihiro Yamashiro

Nearly all patients infected with hepatitis C virus (HCV) genotype 1b have reactivity to the core (c22‐3) or non‐structural (NS)‐3 region (c33c) protein in a second‐generation recombinant immunoblot assay (RIBA‐2). However, reactivities to the NS‐4 region antigens (5‐1‐1, c100‐3) vary among patients. To clarify whether differences in serological reactivities to the NS‐4 antigens are associated with the clinical features or response to interferon (IFN) therapy of patients infected with hepatitis C virus (HCV) genotype 1b, we clinically investigated 115 such patients. Positive reactions to 5‐1‐1 and c100‐3 were seen in 75.7 and 79.1%, respectively, of the patients. There were no differences between the patients with and those without antibodies to NS‐4 region antigens (5‐1‐1, c100‐3) with regard to age, duration of HCV infection, severity of liver disease and virus load. Fifty‐one of the patients were treated with recombinant IFN‐α, and 17 of the 51 patients showed sustained response to the therapy. The sustained response was more frequently seen in the patients positive for antibodies to both 5‐1‐1 and c100‐3 as compared with those negative for either or both antibodies (41.0% vs. 8.3%, P < 0.05).


Hepatology Research | 1999

Performance of serological typing of hepatitis C virus (HCV) in patients who have cleared HCV-RNA from their serum

Hiroshi Sakugawa; Hiroki Nakasone; Tomofumi Nakayoshi; Yuko Kawakami; Tsuyoshi Yamashiro; Yukino Kugai; Ryoji Matayoshi; Fukunori Kinjo; Atsushi Saito

To evaluate the performance of serological typing of hepatitis C virus (HCV) in persons who have resolved an HCV infection, sera from 43 patients with HCV-related liver disease who had cleared HCV-RNA from their serum during the observation period were assayed for serotype using an enzyme-linked immunosorbent assay (ELISA). The assay uses type-specific recombinant peptides (C14-1 and C14-2) derived from the putative NS-4 region of the HCV. Before clearing HCV-RNA, 39 of the 43 patients assayed for serotype were typable; 21 had group 1 (G1) and 18 had group 2 (G2) serotype. After clearing HCV-RNA, only one (4.8%) of the 21 patients infected with G1 became untypable, showing negativity for the antibody to C14-1. In contrast, eight (44.4%) of the 18 patients infected with G2 became negative for antibody to C14-2, resulting in untypable test results in the serotyping ELISA. There was a significant difference in the disappearance rate of type-specific antibody between the patients infected with G1 and those infected with G2 (P<0.01, log-rank test). In conclusion, with the serological typing ELISA, the retrospective typing of HCV was possible in the majority of the 43 patients who had cleared an HCV infection, particularly in patients who had had type 1 isolates.

Collaboration


Dive into the Tomofumi Nakayoshi's collaboration.

Top Co-Authors

Avatar

Fukunori Kinjo

University of the Ryukyus

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Hiroki Nakasone

University of the Ryukyus

View shared research outputs
Top Co-Authors

Avatar

Yuko Kawakami

University of the Ryukyus

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Hayashi Shokita

University of the Ryukyus

View shared research outputs
Researchain Logo
Decentralizing Knowledge