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Biomedical subjects

T Komatsu

Publications and source records attributed to T Komatsu.

At least 325 records · Page 18Linked to original sources
PubMed1986

[Morphological studies of the upper end of the femur. I. Measurements of the diameter of the femoral head and neck].

The mediolateral diameters (MLD) and the anteroposterior diameters (APD) of the head and neck of the upper end of 170 femurs excised from autopsy cases were measured in the moist state and analyzed by computer. The mean actual measurements (mm) were: 47.3 (MLD) and 47.2 (APD) for femoral head diameters; 44.6 (MLD) and 40.9 (APD) for subcapital diameters; 33.5 (MLD) and 27.5 (APD) for midcervical diameters; and 44.0 (MLD) and 27.9 (APD) for basilar diameters. Multiple regression analysis of the relation between the stature and the diameters of the femoral head and neck showed that femoral head diameters were related most closely to the stature. The mean values of the diameters of the femoral head and neck exhibited significant sexual differences (p less than 0.01). When the right and left measurements were compared, the femoral head diameter tended to show a significant difference (p less than 0.1); there was also a significant difference in the subcapital diameter (p less than 0.05).

Adult↗
PubMed1985

Antigenic variation and resistance to neutralization in poliovirus type 1.

Mutations have been identified in variants of poliovirus, type 1 (Mahoney) on the basis of their resistance to neutralization by individual monoclonal antibodies. The phenotypes of these variants were defined in terms of antibody binding; the pattern of epitopes expressed or able to be exploited for neutralization were complex. Single amino acid changes can have distant (in terms of linear sequence) and generalized effects on the antigenic structure of poliovirus and similarly constituted virions.

Amino Acid Sequence↗
PubMed1985

The obligatory intermediacy of 16,17 alpha- and 16,17 beta-epoxides in the biotransformation of androsta-5,16-dien-3 beta-ol to androst-5-ene-3 beta, 16 alpha, 17 beta- and -3 beta, 16 beta, 17 alpha-triols by male rat liver microsomes.

The C16-double bond of the biolefinic steroid, androsta-5,16-dien-3 beta-ol (delta 16-ANDO), was regioselectively oxidized by male rat liver microsomes in the presence of NADPH and EDTA to 16 alpha, 17 alpha-epoxyandrost-5-en-3 beta-ol (delta 16-ANDO 16,17 alpha-epoxide), 16 beta,-17 beta-epoxyandrost-5-en-3 beta-ol (delta 16-ANDO 16,17 beta-epoxide), androst-5-ene-3 beta, 16 alpha, 17 beta-triol (delta 16-ANDO 16 alpha, 17 beta-glycol), and androst-5-ene-3 beta, 16 beta, 17 alpha-triol (delta 16-ANDO 16 beta, 17 alpha-glycol). The microsomes hydrolyzed delta 16-ANDO 16,17 alpha-epoxide specifically to the 16 beta, 17 alpha-glycol and delta 16-ANDO 16,17 beta-epoxide to the 16 beta, 17 alpha-glycol and the 16 alpha, 17 beta-glycol in an equal ratio. delta 16-ANDO 16,17 alpha-epoxide was much more susceptible to microsomal hydrolysis than the 16,17 beta-epoxide. The xenobiotic epoxide hydrolase inhibitor, 3,3,3-trichloropropene 1,2-oxide, potently inhibited microsomal hydrolysis of delta 16-ANDO 16,17-epoxides as well as of benzo[a]pyrene 4,5-epoxide and styrene 7,8-epoxide. Addition of 3,3,3-trichloropropene 1,2-oxide accumulated the 16,17-epoxides formed from delta 16-ANDO in the reaction medium with concomitant decrease in the amounts of the 16,17-glycols formed, leading to a conclusion that the 16,17-epoxides played a role as obligatory intermediates in the microsomal delta 16-oxidation of delta 16-ANDO to the 16,17-glycols. Epoxidation of delta 16-ANDO was stereoselectively mediated by a cytochrome P-450 with quite unique properties to form the 16,17 alpha-epoxide as the major oxidation product and the 16,17 beta-epoxide as the minor. The epoxidation was strongly inhibited with CO, activated with 2-diethylaminoethyl 2,2-diphenylvalerate hydrochloride more than twice as much, and little affected with metyrapone and 7,8-benzoflavone. A pretreatment of the animals with 3-methylcholanthrene induced the delta 16-ANDO-epoxidizing activity of their microsomes 1.5 times higher than those from the control animals. However, a pretreatment with phenobarbital reduced the enzyme activity to one-half of the control microsomes. Under the same conditions, microsomal activities of hydroxylation of benzo[a]pyrene and N-demethylation of benzphetamine were significantly induced by the pretreatments with 3-methylcholanthrene and phenobarbital, respectively.

Androstenols↗
PubMed1985

Diving pattern of Tsushima male breath-hold divers (Katsugi).

The present study was undertaken to investigate the diving pattern, buoyancy-mass relationship, and some respiratory functions in professional male breath-hold divers in Tsushima Island, Japan. These divers always wear neoprene wet suits and use fins and 4-kg counterweights. They usually dive to 3-10 m depths. The rate of descent was 1.12 m/s for deeper dives (greater than 10 m), which is nearly twofold greater than that of Korean female divers also wearing wet suits and fins. However, the rate of ascent (0.8 m/s) was comparable to that of Korean women divers. On a typical summer day, they spend nearly 4 h in the water and perform 175 dives. The average dive and surface time were 39 and 42 s, respectively. The total bottom time was estimated to be 67 min/d, nearly twice that of Korean women divers. These divers do not adjust the counterweight and all are using a 4-kg weight. Nevertheless, the buoyancy-mass relationship revealed that they maintain the same degree of positive buoyancy (approximately 10% above the neutral level) at surface as do Korean women divers who adjust counterweights. The vital capacity was significantly greater in the diver than in the control (P less than 0.05), which was largely due to the greater expiratory reserve volume in the diver. The end-tidal O2 and CO2 pressures of the diver resting in air were not different from those of the control. These results indicate that, while the basic diving pattern is similar in both male and female breath-hold divers, the overall efficiency of diving (in terms of the rate of descent and the bottom time) appears to be superior in male divers.

Adult↗
PubMed1984

Ultrastructural studies on the pathogenesis of poliomyelitis in monkeys infected with poliovirus.

Poliovirus was inoculated intraspinally into cynomolgus monkeys to determine whether nerve cell damage in the central nervous system (CNS) is due primarily to virus multiplication in the neuron or to secondary effects of virus multiplication in the supporting cells. Electron-microscopically, the development of cytopathogenesis and of membrane-bound vesicles and virus particles in the neurons of the CNS in monkeys infected with poliovirus was compared with that of infected cultured cynomolgus monkey kidney (CMK) cells. The structure of membrane-bound vesicles in cytoplasm of damaged motoneuron was examined and found to be similar to the vesicles in infected cultured CMK cells. Virus-like particles were detected occasionally around or within membrane-bound vesicles in the cytoplasm of degenerating motoneurons as well as cultured CMK cells, although intracytoplasmic crystals were not detected in the neuron. No virus particles or membrane-bound vesicles were found in astrocyte foot plates, microglia, oligodendrocytes, axons, vascular endothelial, and inflammatory cells. In addition, poliovirus antigen was detected only in the nerve cells of the CNS by the immunoperoxidase technique, although specific staining was never found in the supporting tissues. From the present results we suggest that membrane-bound vesicles in the cytoplasm of the motoneuron are closely correlated with virus multiplication and that damage of the nerve cell is due to the direct action of the poliovirus.

Animals↗
PubMed1984

An immune adherence assay for discrimination between etiologic agents of hemorrhagic fever with renal syndrome.

Antigens of the viruses that cause hemorrhagic fever with renal syndrome (HFRS) and antibodies to these antigens were titrated in an immune adherence hemagglutination (IAHA) test and a CF test. Vero-E6 cells infected with the SR-11 strain of HFRS virus, an isolate from rats associated with a laboratory outbreak in Japan, and the 76-118 strain of Hantaan virus, the etiologic agent of Korean hemorrhagic fever, were used as antigens in the IAHA, CF, and indirect immunofluorescent antibody (IFA) tests. Sera from patients with different types of HFRS were tested against both strains of virus. Titers of antibody detected by the IFA test were similar for the two strains, but the IAHA test discriminated between antibodies to the two types of HFRS virus. Antigenic differences between HFRS viruses were suggested by the results of the IAHA test.

Animals↗
PubMed1984

Infectivity titration of hemorrhagic fever with renal syndrome virus: use of immune adherence hemagglutination for detection of virus growth.

Serial dilutions of hemorrhagic fever with renal syndrome viruses were inoculated into Vero-E6 cells in microplates. After 2 weeks of incubation, infected cells were disrupted by freezing and thawing, and virus antigens were detected by immune adherence hemagglutination. The infectivity titers of the virus as determined by this method were in close agreement with those obtained by the immunofluorescent antigen endpoint method. Then, a neutralization method was established. Japanese hemorrhagic fever with renal syndrome isolates, strains SR-11 and TR-352, were found to be distinct from Hantaan virus, strain 76-118, by the neutralization test.

Animals↗