Search PubMed⌕ Search

Biomedical subjects

K Hayashida

Publications and source records attributed to K Hayashida.

At least 325 records · Page 18Linked to original sources
PubMed1984

[Diagnosis of myocardial infarction using single photon emission computed tomography: comparison between visual and quantitative diagnosis].

For diagnosing myocardial infarction by myocardial scintigraphy using 201TlCl, the following two items were compared: 1) The diagnostic accuracy of visual evaluation of myocardial planar images versus that of single photon emission computed tomography (SPECT) images. 2) The diagnostic accuracy of qualitative and quantitative evaluations of SPECT images. The planar and SPECT methods were performed for 81 subjects consisting of 41 patients having myocardial infarction and 40 normal persons. Receiver operator characteristic (ROC) analysis, which is most objective in evaluation of visual diagnosis, was also used. To analyze quantitative diagnosis by ROC analysis, the normal range of circumferential profile analysis of myocardial short-axial tomography was determined by assessing five step divisions (less than 1 SD, 1-1.7 SD, 1.7-2.3 SD, 2.3-3 SD, and more than 3 SD) from 10 normal cases. Four physicians and three laboratory technicians familiar with myocardial images diagnosed the myocardial planar images and SPECT images individually. The results were analyzed and the ROC curves were constructed. The results indicated that image diagnosis by SPECT was superior to that by the visual planar method for all persons. The physicians who had more experience in diagnosing myocardial images made more accurate diagnosis. However, quantitative SPECT image diagnosis was superior to visual SPECT image diagnosis. Thus, with the input of data of the normal range of quantitative SPECT image diagnosis into the computer, the prospects of accurate computer assessments of myocardial infarctions were posed.(ABSTRACT TRUNCATED AT 250 WORDS)

Humans↗
PubMed1983

Prevalence of antibody to hepatitis A virus in Okinawa and Kyushu, Japan.

Between 1968 and 1981, a total of 1955 serum samples from healthy subjects chosen at random in seven districts of Okinawa and two districts of Kyushu were surveyed for antibody to hepatitis A virus (anti-HAV) by radioimmunoassay. Overall prevalence of anti-HAV was 55.1% in Okinawa and 35.9% in Kyushu. Prevalence of less than 10% was observed in subjects less than or equal to 14 years of age in Okinawa and less than or equal to 24 years of age in Kyushu. In three of the districts of Okinawa, second serum samples were collected after intervals of eight, 10, and 12 years, respectively. Overall prevalence of anti-HAV decreased significantly over these time periods. When the age-specific prevalence of anti-HAV on the first occasion is compared with that on the second occasion, it can be seen that there have been few new cases of hepatitis A infection. These data suggest that hepatitis A infection among children has declined dramatically in recent years, and that young people may be highly susceptible to hepatitis A virus.

Adolescent↗
PubMed1983

An epidemiologic study of hepatitis B virus in Okinawa and Kyushu, Japan.

In 1968-1981, a total of 3222 serum samples were collected from healthy subjects in Okinawa--in Ishigaki City, on Hateruma Island, and on Iriomote Island--and in Kyushu, in Fukuoka City and Nichinan City. These serum samples were tested for the presence of hepatitis B surface antigen (HBsAg) by reverse passive hemagglutination (RPHA), for antibody to hepatitis B surface antigen (anti-HBs) by passive hemagglutination (PHA) and radioimmunoassay (RIA), and for antibody to hepatitis B core antigen (anti-HBc) by RIA. Overall prevalence of HBsAg (7.5%), anti-HBs by PHA (41.0%) and RIA (56.4%), and anti-HBc (65.5%) in Okinawa was significantly higher than prevalence of HBsAg (2.4%), anti-HBs by PHA (24.7%) and by RIA (28.1%), and anti-HBc (30.9%) in Kyushu. In both areas, anti-HBc was more frequently detected than anti-HBs by both methods. In Okinawa, HBsAg was significantly more prevalent in males than in females. No significant differences by sex in other hepatitis B virus markers were found. On Iriomote Island and Ishigaki City, second samples were collected after intervals of 10 and 12 years, respectively. Over these periods, the prevalence of all hepatitis B virus markers decreased significantly for the 0-9 and 10-19 year age groups. These data suggest that hepatitis B infection among children has declined in recent years and that high prevalence of hepatitis B infection in adults may reflect high rates of infection in their childhood.

Adolescent↗
PubMed1983

Subtypes of hepatitis B surface antigen in familial clusters of hepatitis B virus carriers.

A total of 919 hepatitis B surface antigen (HBsAg) positive serum samples from Kyushu and Okinawa, Japan, were subtyped for the d, y, w, and r specificities. There was a great difference in distribution of subtypes between Kyushu, where over 70% of the samples were adr, and Okinawa, where over 70% were adw. Among 306 members of 109 families with two or more hepatitis B virus carriers, HBsAg subtype was always identical within each family, even when there had been close contact between members of families with different subtypes. These results suggest that transmission of hepatitis B virus occurred within families rather than between members of different families, even when there was close contact between members of different families.

Carrier State↗