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Biomedical subjects

T Fukunaga

Publications and source records attributed to T Fukunaga.

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

Variation of glutathione level and synthesis activity in chick liver due to selenium and vitamin E deficiencies.

Chicks were fed an amino acid mixture-based diet (basal diet) or one supplemented with selenium (Se, 0.2 micrograms/g as Na2SeO3) and/or vitamin E (100 micrograms/g as alpha-tocopherol). The group receiving the basal diet devoid of Se and vitamin E showed a tendency to grow slowly, but not significantly so, compared to the non-deficient control and manifested a symptom of exudative diathesis after the feeding period of 4 weeks. Supplementation of the basal diet with Se or vitamin E prevented the deficiency symptoms in the chicks. The hepatic GSH level and GSH synthesis activity were about three times as much in the Se- and vitamin E-deficient group as in the control. This was also the case for in vivo sulfur incorporation into hepatic GSH for 10 h post-injection with [35S]methionine. The increased level of GSH may partly compensate the hepatocytes for peroxidative damage.

Animals↗
PubMed1984

Electron microscopic observation of a newly isolated flavivirus-like virus from field-caught mosquitoes.

Of many unidentified virus strains which were isolated from field-caught mosquitoes by using C6/36 cells (a virus-sensitive clone of Aedes albopictus cells), three strains which formed small size plaques (SP virus) in C6/36 cells were investigated by electron microscopy. Although the SP virus strains did not react with antisera against known arboviruses in serological tests, they closely resembled flaviviruses in morphology. However, when they were compared to Japanese encephalitis (JE) virus, several differences in morphogenesis were observed. Proliferating membranous structures and electron-dense amorphous areas involving precursors of the virus were observed only in cells infected with the SP virus strains. Enlarged areas of endoplasmic reticulum containing mature virions were often observed adjacent to these structures. Since the SP virus strains were isolated from wild mosquitoes and multiplied only in mosquito cells, it seems appropriate to classify them as insect viruses which resemble togaviruses morphologically.

Aedes↗
PubMed1984

A seroepidemiological study of Japanese encephalitis and dengue virus infections in the Chiang Mai area, Thailand.

As part of a virological and epidemiological survey of encephalitis in the Chiang Mai area, the neutralizing (N) antibody levels of healthy persons to Japanese encephalitis (JE) and dengue (DEN) type 1-4 viruses were examined. A total of 985 blood samples was collected by the filter paper method from subjects of nine age groups in five districts, four (Pasang, Sarapee, Doi Saket and Mae Taeng) in the Chiang Mai Valley and one (Fang) in another valley separated by several ranges of mountains from the Chiang Mai Valley. From analyses of the results of N tests on the specimens, the following conclusions were drawn about the prevalences of JE and DEN viruses in the Chiang Mai area: (1) In the Chiang Mai Valley, the percentage incidences of N antibodies to JE and DEN viruses increased with age and by the age of 15, two thirds or more of the residents had been infected with JE and all DEN viruses except DEN type 2 virus, which showed the lowest prevalence. (2) In the Fang district, the percentage incidence of N antibody to JE virus increased with age, but those to DEN viruses did not, indicating much lower prevalences in the past of all four serotypes of DEN viruses in this district than in the Chiang Mai Valley. (3) At present, most infants in the Chiang Mai area, including the Fang district, seem to be exposed to DEN viruses first and later to JE virus.

Adolescent↗
PubMed1983

Alcohol sensitivity related to polymorphism of alcohol-metabolizing enzymes in Japanese.

Normal Japanese subjects were divided into two groups, i.e., one with both low and high Km isozymes of aldehyde dehydrogenase for acetaldehyde, and the other deficient in the low Km isozyme. After intake of 0.4 g/kg alcohol, the deficient subjects showed high level of blood acetaldehyde, facial flushing and the other dysphoric symptoms, including increase of pulse rate, decrease of diastolic blood pressure, changes of pulse wave in the fingertip, and elevation of the arterial pressure and blood flow rate in common carotid arteries as well as increase of plasma catecholamines level. In contrast, subjects with normal ALDH did not show these changes. From the observation of liver specimens obtained at autopsy, the frequency of deficient phenotype of ALDH in Japanese was presumed to be about 36%.

Acetaldehyde↗
PubMed1983

Enzyme assays to detect preovulatory human luteinizing hormone surge.

Nonradioisotopic enzyme assays have been developed to detect the preovulatory luteinizing hormone (LH) surge in the unextracted urine of normally menstruating women. The amino groups on 6-mm glass beads were activated and coupled to the anti-LH-gamma-globulin for enzyme immunoassay or to the LH receptor prepared from bovine corpora lutea for enzyme receptorassay. The LH was conjugated with alkaline phosphatase. The enzyme assays detected preovulatory LH surge in the morning urine samples of 12 normally menstruating women. The LH surge was coincidental with preovulatory serum estradiol rise, shift in basal body temperature, and 4+ spinnbarkeit of the cervical mucus. The serum estradiol and progesterone levels in the luteal phase were indicative of corpus luteum formation.

Adult↗
PubMed1983

Flavivirus infections in Chiang Mai area, Thailand, in 1982.

Infection by JE virus still constitutes major cause of encephalitis in Chiang Mai Area, although some cases of possible dengue encephalopathy were observed. In spite of many apparent encephalitis cases, infection of vector mosquitoes by JE virus was not demonstrated. Virus isolation from hospitalized patients showed that the principal type of dengue virus circulating in Chiang Mai in 1982 was type 1 virus. Seroepidemiological survey on healthy humans indicated that the northern part of Chiang Mai Province in the region of the Maekong Valley has not yet been invaded so much by dengue viruses, compared with the Chiang Mai Valley, where dengue infection apparently became more prevalent than 12 years ago. The survey also indicated that the spread of JE virus in the study area was not uniform. Survey on vertebrates showed that anti-JE antibodies were highly prevalent among swine, horses, mules, sheep, and dogs. On the other hand, antibody prevalence was low in monkeys, ducks, and sparrows, and was negative among chickens and lizards. IgM-ELISA appeared to help differential diagnosis on JE from dengue even when the HI test did not give positive results.

Adolescent↗
PubMed1983

Retrospective serological studies on dengue epidemics in Osaka and Okinawa.

In Japan, dengue epidemics were recorded once before the end of World War II (1942-1945) on the Main Islands and several times (1893-1955) on the Okinawa Islands. Blood samples were obtained from residents in Osaka and Okinawa, and their antibodies were examined by neutralization tests against dengue and Japanese encephalitis viruses. Of 60 serum samples each from Osaka and Okinawa, 11 and 15 sera, respectively, showed positive titers against one or more dengue serotypes. These results confirm that the epidemics had been very large. Moreover, the results showed that the epidemics had been due to dengue type 1 virus in Osaka and to dengue type 1 and 2 viruses in Okinawa.

Aged↗
PubMed1983

Neutralizing antibody responses to Japanese encephalitis vaccine in children.

Two shots of the current Japanese encephalitis (JE) vaccine were given to children and their immune responses to the Nakayama strain (the vaccine strain) and two wild strains (JaGAr-01 and E-50) of JE virus were examined by neutralizing (N) antibody titrations. Seventy vaccinees had no N antibody to JE virus before the first vaccination and were bled one month after the second vaccination. The N antibody responses to the JaGAr-01 and E-50 strains were found to be similar and to be less than that to the Nakayama strain after the second vaccination: the geometric mean titers (GMT) of N antibodies to the JaGAr-01 and E-50 strains (as logarithms) were 1.87 and 1.75, respectively, while the GMT to the Nakayama strain was 2.89. The seroconversion rates to the Nakayama, JaGAr-01 and E-50 strains were 70/70 (100%), 69/70 (99%) and 68/70 (97%), respectively, after the second vaccination. Twenty-seven of the 70 vacciness were also bled before the second vaccination. Most of them showed a considerably high N antibody response against the Nakayama strain and only one vaccinee failed to show seroconversion after the first vaccination. However, the antibody response to the E-50 strain appeared to be rather low and 9 of 25 vaccinees did not show any seroconversion. Similarly 3 of 25 failed to show any seroconversion against the JaGAr-01 strain. These results indicate that at the initial immunization two shots, at least, of the current JE vaccine are necessary to stimulate effective immune responses to wild strains of JE virus.

Aging↗
PubMed1983

A retrospective serological study of Japanese who contracted dengue fever in Thailand.

Between September and November 1981, some members of a survey team from Japan suffered from a febrile illness diagnosed clinically as dengue fever during their stay in a village in Khon-Kaen Province, in the north-eastern part of Thailand. The morbidity rate in the team was as high as 69% (11/16). Blood samples were taken from 12 of the 16 members of the team in February, 1982 in Japan and the serum specimens were examined for antibodies to dengue (DEN), Japanese encephalitis (JE) and yellow fever (YF) viruses respectively. The results of the tests indicated that all 8 members who had had symptoms had been infected with DEN type 1 virus. No case of inapparent infection with dengue viruses was found. Of these 8 persons, seven had had neutralizing (N) antibody to JE virus before infection, but their clinical manifestations had been similar to those of an individual without N antibody to JE virus and were typical symptoms of dengue fever, such as leukopenia and "saddle-back" fever, without hemorrhagic manifestations, as seen from platelet counts and hematocrit values.

Adult↗
PubMed1983

Serological studies on volunteers inoculated experimentally with a dengue virus strain in 1943.

In 1943, a large dengue epidemic occurred in the Osaka district and several samples of dengue virus were isolated from patients with dengue fever by workers in this Institute. These were inoculated into human volunteers to confirm that they were dengue virus. In the present study, serum samples were collected from the volunteers who had been inoculated with dengue virus and were examined serologically. In the neutralization test, all the sera showed a higher titer against dengue type 1 virus (DEN-1) than against the other three types of dengue virus, indicating that the virus strain isolated in 1943 was DEN-1.

Antibodies, Viral↗
PubMed1982

Phospholipase C activity in egg yolk sac of Japanese quail during embryonic development.

1. The amount of lipid decreased markedly at the later stage of embryonic development, coinciding with the remarkable decrease in yolk weight. 2. Phospholipase C activity in the yolk sac appeared on the 6th day of incubation and increased markedly as incubation proceeded. 3. The enzyme showed its optimum activity at pH 9.5 and at 40 degrees C. 4. The activity was enhanced 2-fold by 20 mM CaCl2 and by 40% by 4 mM deoxycholate but inhibited by 2 mM ZnCl2 and CuSO4.

Animals↗
PubMed1982

Familial Bartter's syndrome and the effect of indomethacin in one family member.

A Japanese family in which a father, daughter and son had hypokalemia and hyperreninemia was investigated. Both father and daughter had reduced vascular sensitivity to angiotensin II; in addition, the daughter had juxtaglomerular cell hyperplasia and dwarf glomeruli. These features are consistent with Bartter's syndrome occurring in 2 successive generations in 1 family. The 12-year-old girl had growth retardation in spite of normal growth hormone secretion. No chromosomal abnormalities were found. Indomethacin administration to this patient in doses sufficient to reduce urinary prostaglandin excretion resulted in a marked improvement of polydipsia and polyuria, and an increase in serum sodium, potassium and chloride concentrations. Even though plasma aldosterone concentrations were reduced to within the normal range, serum potassium concentrations remained low, and plasma renin activity (PRA) remained elevated. Thus it is not likely that hypokalemia is induced only by aldosteronism. These results suggest that prostaglandins are the major determinant of polydipsia, polyuria and high plasma aldosterone levels and contribute to the hypokalemia observed in this patient. However, the failure of complete correction of the hypokalemia and the persistence of the raised PRA with a significant reduction of the prostaglandins suggest the possibility that additional factors are involved in the pathogenesis of Bartter's syndrome.

Adult↗
PubMed1982

Serological studies on a case of laboratory dengue infection.

One of the authors (Y.O.), who had previously been immunized with Japanese encephalitis (JE) vaccine, showed symptoms of typical dengue fever 6 days after accidental infection with a newly isolated dengue type 4 virus strain from a patient with dengue hemorrhagic fever (DHF) in Thailand. His sera were examined by hemagglutination inhibition (HI), complement fixation (CF) and neutralization (N) tests. The JE N antibody titers of his sera were high even on the first day of the illness and remained almost constant during the next year. Antibodies that reacted with dengue viruses were detected from a very early stage of the illness by all three serological tests. In addition, his convalescent phase sera showed high titers against all 4 types of dengue virus. These data suggest that the dengue infection caused secondary stimulation of antigens of flavivirus. Sedimentation analysis of antibodies in Y.O.'s serum (day 9) was carried out and IgM antibody that reacted only with dengue type 4 virus and homologous infecting virus was separated. These findings clearly demonstrated that the laboratory infection of Y.O. was primary dengue infection with dengue type 4 virus.

Antibodies, Viral↗