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Biomedical subjects

H Ohmoto

Publications and source records attributed to H Ohmoto.

25 records · Page 2Linked to original sources
PubMed1993

3.4-Billion-year-old biogenic pyrites from Barberton, South Africa: sulfur isotope evidence.

Laser ablation mass spectroscopy analyses of sulfur isotopic compositions of microscopic-sized grains of pyrite that formed about 3.4 billion years ago in the Barberton Greenstone Belt, South Africa, show that the pyrite formed by bacterial reduction of seawater sulfate. These data imply that by about 3.4 billion years ago sulfate-reducing bacteria had become active, the oceans were rich in sulfate, and the atmosphere contained appreciable amounts (>>10(-13) of the present atmospheric level) of free oxygen.

Geologic Sediments↗
PubMed1992

Detection of capsid antigen of human papillomavirus (HPV) in benign lesions of female genital tract using anti-HPV monoclonal antibody.

We established a murine monoclonal antibody (K1H8) to human papillomavirus (HPV) using alkaline-disrupted virions of HPV type 1 (HPV-1) as the immunogen. K1H8 recognized a 57 kD capsid protein of HPV-1 and detected the antigen in paraffin sections of formalin-fixed tissue. With K1H8, we examined immunohistochemically 68 biopsy specimens obtained from the female genital tract. The specimens were histologically condyloma acuminatum or koilocytotic lesions with or without dysplasia and each specimen was found to harbour a single type of genital HPV, such as types 6, 11, 16, 18, 31, 33, 42, 51, 52, 56, and 58, by Southern blot hybridization analysis. The antigen was localized in the nuclei and occasionally in the cytoplasm of squamous cells showing koilocytotic changes. Eighty-four per cent of the specimens (57 cases) showed positivity for the antigen, indicating that K1H8 is a broadly-reactive antibody to various genital HPVs. The results suggest that benign mucosal lesions of the female genital tract are more frequently associated with viral production and are a potential source of transmission.

Animals↗
PubMed1992

Development changes of polyamine biosynthesis in rat liver.

To investigate the role of polyamine metabolism in fetal development, we determined the hepatic polyamine content and the activity of enzymes related to polyamine metabolism in fetal, newborn and adult rats. In the fetuses, spermidine was detected at the highest level, followed by spermine and then putrescine. Putrescine and spermidine levels were higher in the fetuses than in adult rats, while the spermine level was significantly lower in the fetuses. The activities of the enzymes investigated were also higher in the fetuses than in adult rats. These findings indicate that polyamine synthesis was enhanced in the fetal liver, and that degradation of spermidine via spermidine N1-acetyltransferase contributes to the increase in putrescine levels. Thus, our study suggests that an increase in putrescine is important for fetal growth and that putrescine per se has a significant role in fetal cellular proliferation.

Acetyltransferases↗
PubMed1987

[Changes in enzyme activity associated with polyamine metabolism in the liver of experimental IUGR rats].

Changes in ODC, SAMDC and SAT activities, the rate limiting enzymes in the polyamine metabolism were measured in the liver of the rat fetuses with experimental intrauterine growth retardation (IUGR). The following results were obtained: In IUGR, which was induced by ligation of uterine vessels in one of the two uterine horns at the 17th day of gestation, the weight of the carcass and the liver was significantly reduced. During normal development of the rat fetus, ODC activity in liver of the control group decreased. ODC activity of IUGR liver decreased significantly from the 18th day of gestation compared with that of the control group. SAMDC activity of IUGR liver increased and was significantly greater than that of the control group. Thereafter the activity decreased at a similar rate to that of the control group. SAT activity of IUGR liver decreased significantly from the 18th day of gestation compared with that of the control group. These results suggest that it is suppressed to raise the putrescine level caused by ODC (ornithine----putrescine) and SAT (spermidine----putrescine) in IUGR liver from the viewpoint of polyamine metabolism.

Acetyltransferases↗
PubMed1986

[Changes in enzyme activity associated with polyamine metabolism in the rat fetal liver during the perinatal period].

Changes in ODC, SAMDC and SAT activity, the rate limiting enzymes in the polyamine metabolism, were measured in the liver of developing rats during the perinatal period. The following results were obtained: ODC activity in fetal rat liver at the 15th day of gestation was 120-fold greater than in mature rat liver, but decreased dramatically as pregnancy advanced. ODC activity during the neonatal period fluctuated at a low level compared with that of the fetus, except for a slight increase at day 5 after birth. SAMDC activity in fetal and mature rat liver was high, but was relatively unchanged throughout the period of development compared with ODC activity. It decreased gradually and increased again toward the mature level from day 5 after birth. SAT activity in fetal rat liver at the 15th day of gestation was significantly high (3-fold that in mature liver) and decreased rapidly with continued fetal development until the 21st day of gestation, when the activity attained that found in mature liver. Thereafter its level was almost constant. There was a positive correlation between ODC activity and growth rate (daily percentage increase) in the weight of liver (r = 0.92, p less than 0.001). There was a similar correlation between SAT activity and growth rate (r = 0.95, p less than 0.001). These results suggest that it is important to raise the putrescine level caused by ODC ornithine----putrescine) and SAT (spermidine----putrescine) with continued fetal development from the viewpoint of polyamine metabolism, which are thought to be involved in cellular proliferation and tissue growth.

Acetyltransferases↗
PubMedDate not supplied

Masseter reflex potentials in olivo-ponto-cerebellar atrophy.

We recorded masseter reflex potentials to examine the correlation between the masseter reflex and the muscle stretch reflexes of limbs in 19 patients with olivo-ponto-cerebellar atrophy (OPCA). The patients were subdivided into hyper- (n = 5), normo- (n = 7) and hypo- (n = 7) reflexia groups according to the degrees of the conventional deep tendon jerks in the upper limbs. The masseter reflex potentials, elicited by tapping the chin with a reflex hammer, were recorded from the bilateral masseters using a pair of surface electrodes. The latency of the potentials in the hyporeflexia was significantly longer than in the other groups, while the amplitude of those in the hyperreflexia group was significantly higher than in the other groups. These results indicate that in patients with OPCA the magnitude and latency of the masseter reflex correlates with the status of the muscle stretch reflexes of the limbs in contrast with Friedreich's ataxia where the masseter reflex has been reported to be normal or hyperactive despite hyporeflexia in the limbs.

Adult↗