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Biomedical subjects

H Ishihara

Publications and source records attributed to H Ishihara.

At least 577 records · Page 32Linked to original sources
PubMed1983

[The significance of dural sinus pressure in neurological surgery-- correlation with surgical position].

A study was made of the significance of confluens sinus pressure in various surgical positions and of various factors influencing confluens sinus pressure. The following findings were obtained: Confluens sinus pressure in various positions was follows: Reverse jackknife position (supine position with upper and lower halves of the body elevated ca 20 degrees) 1.3 +/- 0.8 (Mean +/- SD) cmH2O Sea lion position (prone position with upper and lower halves of the body elevated ca 10 degrees with neck hyperextended) 2.7 +/- 0.6 cmH2O Prone position 5.8 +/- 0.9 cmH2O Supine position 5.9 +/- 1.7 cmH2O Right lateral position 6.9 +/- 0.7 cmH2O Left lateral position 9.6 +/- 1.2 cmH2O Since confluens sinus pressure is strongly affected by gravity, the determination point, the height of the right atrium, and the central venous pressure were referred to when measuring the surgical position. When the upper half of the body was raised (at angle ranging from--10 degrees to +90 degrees) confluens sinus pressure became zero in adults when the angle was +25 degrees or thereabouts. When the angle was +90 degrees, a marked negative pressure of -12.7 +/- 3.0 cmH2O, was observed, suggesting the danger of air embolism. In 4 children under 6 years of ago, however, negative pressure was not observed even at an angle of +90 degrees, although some changes due to different angles were noted. This suggests some specificity of dural sinus pressure. Intrathoracic negative pressure at inspiration, the contraction of skeletal muscles, and profuse hemorrhage, and sympathetic nervous strain were surmised as other factors influencing dural sinus pressure.

Adult↗
PubMed1982

A study of fetal growth retardation in teratological tests: relationship between body weight and ossification of the skeleton in rat fetuses.

The normal development of preterm rat fetuses (day 19.0 to day 21.0) was investigated with respect to body weight and ossification of the sacrococcygeal vertebrae, supraoccipital bone, sternebrae, and proximal phalanges in the forepaw. Normal standard growth curves were established for these indexes in rat fetuses. A method was devised for the analysis of the relationship between low body weight and retarded ossification induced by teratogenic agents. In normal fetuses, mean body weight and number of ossified sacrococcygeal vertebrae and the ossification stage of the supraoccipital bone increased approximately linearly with advancing fetal age. The number of ossified sternebrae and proximal phalanges in the forepaw increased curvilinearly with advancing fetal age. By use of the standard curves, fetal growth retardation observed in teratological experiments may be expressed as retardation in relation to the standard in hours. The characteristic pattern of growth retardation induced by an agent may be evaluated by comparison of the degree of retardation expressed in a common "hour" scale among various growth indexes. This method was applied to experimental data of fetal growth retardation induced by maternal fasting. The degree of retardation was found to differ among growth indexes; body weight and ossification of the sacrococcygeal vertebrae were the most severely retarded; ossification of the supraoccipital bone and the sternebrae was moderately retarded; ossification of the proximal phalanges in the forepaw was least retarded.

Animals↗
PubMed1982

Changes in the density of circulating erythrocytes of the bullfrog tadpole, Rana catesbeiana, in relation to the transition of hemoglobin during metamorphosis.

1. The circulating erythrocytes of Rana catesbeiana tadpoles at varying metamorphic stages were studied by the phthalate-microcapillary technique of Danon & Marikovsky (1964 J. Lab. Clin. Med. 64, 668-674) and by the method of Murphy (1973 J. Lab. Clin. Med. 82, 334-341), which are used for the separation of erythrocytes according to the density. 2. The erythrocytes of tadpoles were different in the mean density from those of adult frogs. 3. At the metamorphic climax, aged erythrocytes having the tadpole hemoglobin coexisted with young erythrocytes having the frog hemoglobin in the circulating blood. 4. The frog hemoglobin was preferentially synthesized during metamorphosis. 5. All the results suggested that the transition of hemoglobin during metamorphosis was associated with the replacement of erythrocyte population.

Animals↗
PubMed1982

Restriction enzyme mapping of the DNA of Streptomyces bacteriophage B alpha and its deletion derivatives.

Cleavage analysis of actinophage B alpha DNA was done with several restriction enzymes, and a restriction map of the DNA was determined. The DNA appeared to carry cohesive ends. Deletion mutants of actinophage B alpha were isolated by five cycles of treatment with 15 mM PPi. Both mutants had deletions of 2.5 of 1.8 megadaltons near one end of the genome, and one of them lost the single EcoRI cleavage site.

Bacteriophages↗
PubMed1982

Fusion of protoplasts of Streptomyces lavendulae.

Protoplasts of two different auxotrophic mutants of Streptomyces lavendulae were fused with polyethylene glycol (PEG) 1,000, and allowed to regenerate on selective media. Prototrophic colonies overwhelmed other types of recombinants on any selective media. These prototrophic strains were stable after successive isolation. These results suggest that stable diploid cells were formed by cell fusion, which differed from the case of S. coelicolor.

Clone Cells↗