Network


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

Hotspot


Dive into the research topics where Miki Hirata is active.

Publication


Featured researches published by Miki Hirata.


Journal of Gastroenterology | 1994

Detection of HCV RNA in subjects with antibody to hepatitis C virus among the general population of Fukuoka, Japan.

Jun Hayashi; Koya Nakashima; Eriko Yoshimura; Miki Hirata; Yoshiaki Maeda; Seizaburo Kashiwagi

Volunteer blood donors and aged people who came to hospitals for a thorough physical checkup were surveyed to evaluated the exact prevalence of hepatitis C virus (HCV) infection in the general population of Fukuoka, Japan. We tested for antibody to HCV (anti-HCV) by second-generation assay and, to distinguish active HCV infection from past resolved infection, we tested for HCV RNA in reactive serum samples by polymerase chain reaction. The prevalence of anti-HCV was 286 (2.0%) of 14341 subjects, increasing with advancing age, from 0.4% in the under-29 age group to 12.0% in the over-70 age group. There were no differences between sexes. HCV RNA was detected in 170 of 286 (59.4%) anti-HCV-positive subjects. The ratio of HCV RNA-positive to anti-HCV-positive subjects was higher in males than in females (P<0.05) and decreased with advancing age, from 72.2% to 46.5%. The prevalence of elevated alanine aminotransferase (ALT) was only 15.9% in subjects with HCV RNA, higher in males (21.4%) than in females (8.3%) (P<0.05). This study revealed that the prevalence of anti-HCV was high in the aged population, but that the ratio of HCV RNA-positive to anti-HCV-positive subjects was low, and most of the HCV RNA-positive subjects had normal ALT levels.


Journal of Infection | 1994

Prevalence and role of hepatitis C viraemia in haemodialysis patients in Japan

Jun Hayashi; Koya Nakashima; Eriko Yoshimura; Yasuhiro Kishihara; Misako Ohmiya; Miki Hirata; Seizaburo Kashiwagi

A second generation assay for antibody to hepatitis C virus (anti-HCV) was used in order to establish the exact prevalence of HCV infection in haemodialysis patients. HCV RNA was sought by the polymerase chain reaction in order to determine whether haemodialysis patients with anti-HCV had been infected with HCV in the past or were presently infected. Of 357 patients, 198 (55.5%) were positive for anti-HCV, compared to 113 (31.7%) positive for original antibody to c100-3 protein (P < 0.001). HCV RNA was detected in 171 (86.4%) of the 198 patients with anti-HCV. Liver dysfunction was found in 63 (17.6%) of all haemodialysis patients. Of these, 55 (87.3%) had HCV infection, one (1.6%) hepatitis B virus infection while, in the remaining seven, the origin was unknown. Thus, in almost all anti-HCV-positive patients, HCV viraemia was present. We conclude that HCV is an important cause of liver disease in haemodialysis patients.


Journal of Gastroenterology | 1994

Seroepidemiology of hepatitis C virus infection in hemodialysis patients and the general population in Fukuoka and Okinawa, Japan

Jun Hayashi; Eriko Yoshimura; Atsuko Nabeshima; Yasuhiro Kishihara; Hideyuki Ikematsu; Miki Hirata; Yoshiaki Maedia; Seizaburo Kashiwagi

In 1992, a seroepidemiologic study was carried out among hemodialysis patients and the general population in Fukuoka and Okinawa, Japan to determine the presence of hepatitis C virus (HCV) infection and HCV viremia. The markers used were antibody to HCV, determined by second-generation assay (anti-HCV), and HCV RNA, determined by the polymerase chain reaction. The prevalence of anti-HCV in Fukuoka was 3.3%, 73 per 2237 persons, significantly (P<0.001) higher than the 0.4%, 5 per 1295, in Okinawa. The prevalence of anti-HCV in hemodialysis patients in Fukuoka was 51.9% (161 of 310 patients), significantly (P<0.001) higher than the 9.1% (13 of 143 patients) in Okinawa. The ratio of HCV RNA-positive to anti-HCV-positive persons was significantly higher in hemodialysis patients (147/174, 84.5%) than in the general population (49/78, 62.8%) (P<0.001). Elimination of HCV among hemodialysis patients appears to be difficult, as such patients have lower immune responses than the general population. In Fukuoka, but not in Okinawa, blood used for transfusion was supplied by paid donors at commercial blood banks from 1953 to 1969. This may explain why HCV infection is endemic in Fukuoka and not in Okinawa. Differences between the prevalence of anti-HCV in the hemodialysis patients in Fukuoka and Okinawa reflect differences in the prevalence in the general population in these two areas of Japan.


Journal of Infection | 1993

Improved detection of antibodies to hepatitis C virus by the second-generation assay in patients with chronic non-A, non-B liver disease

Jun Hayashi; Koya Nakashima; Yasuhiro Kishihara; Misako Ohmiya; Eriko Yoshimura; Miki Hirata; Seizaburo Kashiwagi

Serum samples from 337 Japanese patients with chronic non-A, non-B liver disease were tested for antibodies to hepatitis C virus (HCV) by means of first-generation (c100-3; anti-c100) and second-generation (pHCV-34, pHCV-31, c100-3; anti-HCV II) enzyme linked immunosorbent assays (ELISA) and for antibody to the GOR epitope (anti-GOR) also by ELISA. Anti-HCV II was detected in 314 (93.2%), anti-c100 in 247 (81.3%) and anti-GOR in 211 (62.6%) samples. Thus, anti-HCV II was more sensitive in detecting HCV infection than either anti-c100 or anti-GOR (P < 0.001). All serum samples reactive with anti-c100 or anti-GOR reacted with anti-HCV II. Among 314 anti-HCV II-positive patients, we found that 185 (58.9%) were positive for both anti-c100 and anti-GOR while 14 (4.5%) were positive for anti-HCV II alone. Nine (64.3%) of the 14 are presently infected with HCV, as revealed by detection of HCV RNA in their serum; the remaining five may have been infected in the past with HCV. These findings indicate that HCV is a major causative agent of chronic non-A, non-B liver disease in Japan and that detection of anti-HCV II is a specific and more sensitive diagnostic test for HCV infection.


Journal of Infection | 1994

HBsAg subtypes among HBsAg carriers in Okinawa, Japan. Evidence of an important relationship in seroconversion from HBeAg to anti-HBe

Akinori Noguchi; Jun Hayashi; Koya Nakashima; Miki Hirata; Hideyuki Ikematsu; Seizaburo Kashiwagi

In Okinawa, Japan 1261 hepatitis B surface antigen (HBsAg) carriers were investigated for clinical differences among HBsAg subtypes. Among the 854 for whom they could be determined, subtype adw was found in 604 (70.7%), adr in 232 (27.2%) and others in 18 (2.1%). The overall prevalence of hepatitis B e antigen (HBeAg) was significantly lower in subtype adw (11.9%) than in adr (17.7%) (P < 0.01). The mean age of HBeAg-positive carriers was significantly lower in adw (20.4 years) than in adr (26.9 years) (P < 0.05). Seroconversion from HBeAg to antibody to HBeAg (anti-HBe) occurred in 43 carriers. The seroconversion rate was higher in adw (43.1%) than in adr (29.3%) and the seroconversion age was younger in adw (22.7 years) than in adr (27.9 years). These results suggest that carriers with subtype adw tend to seroconvert from HBeAg to anti-HBe at a higher rate and a younger age than do those with adr. HBsAg subtypes may be closely associated with the HBeAg/anti-HBe status.


Journal of Infection | 1993

Low prevalence of hepatitis C virus infection among hospital staff and acupuncturists in Kyushu, Japan.

Koya Nakashima; Seizaburo Kashiwagi; Jun Hayashi; Akinori Noguchi; Miki Hirata; Saburo Ikeda; Iwane Sakota; Toshimitsu Shingu

During 1987 and 1988, samples of serum were collected from 1097 members of the staff of four prefectural hospitals in Miyazaki prefecture and from 183 acupuncturists in Fukuoka City, Japan. The staff included both surgical and non-surgical doctors, radiographers, physiotherapists, nurses, laboratory technicians and others. The samples were tested for the following hepatitis C virus (HCV) markers; antibodies to c100 (anti-c100) by means of enzyme-linked immunosorbent assay (ELISA) with supplementary recombinant immunoblot assay as well as antibodies to the GOR epitope (anti-GOR), also by means of ELISA. Anti-c100 was present in 1.7% of the doctors, radiographers and physiotherapists, in 1.3% of the nurses and in 2.2% of the acupuncturists. These prevalences were slightly higher than those in the controls but the differences were not statistically significant. Anti-c100 was not detected in any laboratory technician or other member of the hospital staff. For an accurate determination of the prevalence of HCV infection, the combined rate of anti-c100 and/or anti-GOR was also calculated. The combined prevalence of HCV infection was 4.3% in medical staff, 2.2% in nurses and 5.5% in acupuncturists. The prevalence of HCV infection among those with direct contact with patients was higher than that of the controls but without statistical significance. In the cohort we examined, the occupational risk of HCV infection was low.


Antiviral Chemistry & Chemotherapy | 1992

Antiviral Effect of Interferon Therapy for Patients with Chronic Hepatitis C

Jun Hayashi; Koya Nakashima; Akinori Noguchi; Miki Hirata; Kouhei Akazawa; Kashiwagi S

Thirty-two patients with chronic hepatitis who were positive for hepatitis C virus (HCV) RNA by polymerase chain reaction and had antibody to HCV (anti-HCV), were enrolled in this study. Twenty of them were also positive for antibody to the GOR epitope (anti-GOR). Sixteen of the enrolled patients were treated with human lymphoblastoid interferon for six months. Treatment was initiated with 3 million units of interferon daily for 2 weeks, followed by 3 million units three times a week for 6 weeks and 1.5 million units three times a week for 16 weeks. The efficacy of therapy was assessed by comparison with the results in 16 untreated patients. Aminotransferase values, titre of anti-HCV and anti-GOR antibodies showed significant decreases throughout the therapy compared with baseline levels and the untreated patients. After a 3 month follow-up, nine treated patients (56.3%) had normal aminotransferase activities and six of them eliminated HCV RNA from their sera (37.5%). Three of these six patients became negative for both anti-HCV and anti-GOR antibodies (18.8%). None of the untreated control patients had normal aminotransferase activities or became negative for HCV markers. The present study suggests that human lymphoblastoid interferon can control the disease activity and eliminate hepatitis C virus from patients with chronic hepatitis C.


Journal of Infection | 1991

Decrease of hepatitis A and B virus infections in the population of Okinawa, Japan.

Akinori Noguchi; Jun Hayashi; Koya Nakashima; Hideyuki Ikematsu; Miki Hirata; Seizaburo Kashiwagi

In 1988 1282 serum samples were collected from healthy Japanese persons living on Hateruma Island (574 samples) and Iriomote Island (708 samples) in Okinawa, Japan. Serological markers of hepatitis B virus (HBV) infection [hepatitis B surface antigen (HBsAg), antibody to hepatitis B core antigen (anti-HBc) were investigated and the findings compared with samples taken in 1980 on Hateruma Island and in 1970 and 1980 on Iriomote Island. The samples collected in 1988 on Iriomote Island were also tested for antibody to hepatitis A virus (anti-HAV) and the findings compared with the results of the 1970 and 1980 surveys. The overall prevalence of HBsAg and anti-HBc was 3.7 and 64.8% for Hateruma Island and 3.8 and 44.9% for Iriomote Island. In both areas the overall prevalence of anti-HBc was lower than in 1980, the decrease being significant for the 10-19 year age group on Hateruma Island and the age groups under 39 years on Iriomote Island. The overall prevalence of anti-HAV had fallen to 50.9%. This remarkable decrease had occurred in children and young adults. These data suggest that Virus A (HAV) and HBV infections have dramatically decreased among children in Okinawa within the past 2 decades.


Gastroenterologia Japonica | 1991

Glycyrrhizin withdrawal followed by human lymphoblastoid interferon in the treatment of chronic hepatitis B

Jun Hayashi; Wataru Kajiyama; Akinori Noguchi; Koya Nakashima; Miki Hirata; Shin Hayashi; Seizaburo Kashiwagi

SummarySeventeen patients with chronic hepatitis B were treated with a 4-week administration of glycyrrhizin followed by a 4-week treatment with human lymphoblastoid interferon, then followed for 6 months after the end of treatment. All were positive for hepatitis B surface antigen (HBsAg), hepatitis B e antigen (HBeAg), and hepatitis B virus-associated DNA polymerase (DNA-p) for at least 6 months before entry. All patients were Japanese and none of them were homosexuals. Eleven patients lost DNA-p activity and 10 of them lost HBeAg. Three of these 10 patients had antibody to HBeAg. In 10 patients who became HBeAg-negative, alanine aminotransferase levels after glycyrrhizin administration were higher and initial DNA-p activities relatively lower than the levels found in seven patients who remained HBeAg-positive. The immunomodulater provided by a short course of glycyrrhizin before administration of human lymphoblastoid interferon may be an effective treatment for patients with chronic hepatitis B.


Influenza and Other Respiratory Viruses | 2012

The post-infection outcomes of influenza and acute respiratory infection in patients above 50 years of age in Japan: an observational study

Hideyuki Ikematsu; Yuriko Takeuchi; Mats Rosenlund; Naoki Kawai; Ryuji Shimamura; Miki Hirata; Norio Iwaki

Please cite this paper as: Ikematsu et al. (2011) The post‐infection outcomes of influenza and acute respiratory infection in patients above 50 years of age in Japan: an observational study. Influenza and Other Respiratory Viruses 6(3), 211–217.

Collaboration


Dive into the Miki Hirata's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Seizaburo Kashiwagi

Gulf Coast Regional Blood Center

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Yoshiaki Maeda

Gulf Coast Regional Blood Center

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge