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Biomedical subjects

S Sakurai

Publications and source records attributed to S Sakurai.

At least 253 records · Page 14Linked to original sources
PubMed1987

Genetic control of immune response to staphylococcal exfoliative toxin A in mice.

Different inbred and congenic resistant strains of mice were immunized with staphylococcal exfoliative toxin A (ETA). In antibody responses measured in sera of mice by a passive hemagglutination technique, A/J, DBA/2, BALB/c, B10A, B10D2, B10S, and A.SW were high responders. C57BL/10 (B10), A.BY, and DBA/1 were low responders. The congenic C3H/HeJ and C3H.SW mice were, respectively, high and low responders. The observation that the immune responses of the mice to ETA were closely linked with the haplotypes of their H-2 complexes suggests the existence of an H-2-linked immune response (Ir) gene coding for the production of humoral antibodies to ETA. Four B10A recombinants were used to map this gene within the H-2 complex. The finding that B10A(2R) and B10A(4R) were high responders, whereas B10A(3R) and B10A(5R) were low responders, indicates that the gene controlling antibody response to ETA is located in the I-A subregion or the H-2K end within the H-2 complex. We wish to propose the name Ir-ETA for this gene. The function of Ir-ETA seems to be at least related to antigen recognition at the T-lymphocyte level. Neonatal mice are generally susceptible to ETA regardless of their H-2 haplotypes. However, the neonatal mice born to a high-responder mother immunized with ETA were resistant to the subcutaneous challenge of ETA, but those born to an immunized low-responder mother were susceptible to the challenge. This result suggests that if the mother is a high responder to ETA and is effectively immunized with ETA, the maternal immunity makes it possible to neutralize this toxin in neonatal mice.

Animals↗
PubMed1986

[On the compression rate for inhibiting high pressure nervous syndrome under high pressure helium atmosphere].

Bennett (1975) reported that signs and symptoms of the High Pressure Nervous Syndrome (HPNS) appeared including nausea, dizziness, tremors of the hands and arms, increased slow wave activity in electroencephalogram, especially in the theta band (4-7 Hz) with depression of alpha (8-13 Hz) and beta (20 Hz and higher) on compression with oxygen-helium to depths greater than 500 ft (16 ATA). Earlier studies have indicated that the HPNS may be controlled by use of an increased nitrogen partial pressure, slowing compression rate or excluding subject who has higher susceptibility to HPNS. For determining the effect of slowing compression rate, it was changed to new compression profile of linear compression to 31 ATA with intermediate stops in SEADRAGON-VI carried out at JAMSTEC in 1983. All divers to compressed to 31 ATA using the new rate complained few and slight signs and symptoms involved HPNS than ever experienced.

Adult↗
PubMed1986

Temporal relationship between early systolic closure of the aortic valve and aortic flow: experimental study with and without systolic anterior motion of the mitral valve.

To investigate the causative factors of typical early systolic closure (ESC) of the aortic valve (AoV), the temporal relationships of ESC with changes in blood pressures and aortic flow (AoF) were examined in dogs with experimentally induced ESC with and without systolic anterior motion (SAM) of the mitral valve. SAM was induced by dobutamine administration. Typical ESC was observed, but no SAM or left ventricular outflow obstruction, in five of the eight dogs treated with isoproterenol. Regardless of the presence or absence of SAM, the onset of ESC occurred before and the end of ESC immediately after the peak of AoF. A similar time relationship was noted between partial closure of the AoV, and pressure and flow changes before administration of isoproterenol, as well as after its termination. These results exclude a rapid decrease in flow velocity as the cause of ESC in our experimental preparation. The nearly uniform temporal relationship between ESC and changes in AoF observed under various conditions is considered to have important implications in the cause of ESC.

Animals↗
PubMed1986

The effect of hemodialysis on lymphocyte subsets during dialysis.

To clarify the effect of hemodialysis on immune response of dialysis patients, peripheral lymphocyte subsets were measured using monoclonal antibodies, OKT3, OKT4, OKT8, OKIal and Leu7. The absolute numbers of OKT3+, OKT4+, OKT8+ and OKIal+ cells were significantly lower in dialysis patients than controls. During dialysis, the relative proportions of OKT3+ and OKT4+ cells increased, and the absolute numbers of OKIal+ and OKT8+ cells decreased, 30 minutes after initiation of dialysis. At the end of the dialysis, the absolute numbers of OKT3+ and OKT4+ cells increased. The absolute number of Leu7+ cells showed low values during dialysis. These changes of lymphocyte subsets during dialysis may have influence on the immune response of dialysis patients.

Adult↗
PubMed1985

Giant cell tumor of the bladder associated with transitional cell carcinoma.

We report in detail the first giant cell tumor associated with transitional cell carcinoma of the bladder. The giant cell tumor was composed of multinucleated giant and mononuclear stromal cells, and was morphologically indistinguishable from giant cell tumor of the bone. The giant and transitional cell carcinomas showed no evidence of recurrence or metastasis 8 months after transurethral resection. No histogenetic correlation between the cancers was found.

Aged↗
PubMed1985

Production of systolic anterior motion of the mitral valve in dogs.

Production of an experimental preparation of systolic anterior motion (SAM) of the mitral valve was attempted for the purpose of clarifying its causal factors. Fourteen thoracotomized dogs under pentobarbital anesthesia were administered dobutamine, and the echocardiogram, left ventricular pressure, and aortic pressure of each were simultaneously recorded. In two of the dogs in which SAM was produced, two-dimensional echocardiograms were also obtained. Although SAM was absent in all 14 dogs before the administration of dobutamine, it appeared in nine of them after the drug was given. In seven of these dogs, the magnitude of SAM and outflow pressure gradient varied in a dose-dependent manner. No signs of asymmetric septal hypertrophy were observed in any of these dogs. SAM tended to occur even when there was no reduction in preejection period when narrowing of the left ventricular outflow tract was observed. On the two-dimensional echocardiograms, the position of coaptation of the mitral valve was shifted closer to the base of the anterior leaflet in the presence of dobutamine-induced SAM than before the drug was administered. Although the left ventricular cavity became narrow, it was not completely obliterated. This study demonstrates that experimental preparations of SAM can be produced by the administration of dobutamine with a relatively high success rate in normal dogs, and that experimental SAM is accompanied by an outflow tract pressure gradient.

Animals↗