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Y Hoshi

Publications and source records attributed to Y Hoshi.

214 records · Page 12Linked to original sources
PubMed1976

Color functional images of the cerebral blood flow.

Functional gamma imaging, in color, was established for regional cerebral blood flow (rCBF) using 133Xe. During 10 min after intracarotid injection of 133Xe in saline, 60 picture frames of the 133Xe clearance curve for the entire hemisphere were obtained. After nine-point smoothing, the rCBF for each of the 4,096 picture elements was calculated by two methods: the half-time method and the height-over-area method. Both the 133Xe clearance half-times and the calculated CBF values were displayed, using 13 steps of color, as functional CBF images of the brain. Images of peak count and total count were also displayed on the same frame of the color television. Forty-six studies, performed on 37 patients with various cerebral disorders, were divided into two types: diffuse and focal. In the diffuse type, a decrease in CBF was noted in cases of normal-pressure hydrocephalus; successful ventriculoperitoneal shunt operations were followed by recovery of CBF. Occlusion of the middle cerebral artery showed up as a wedge-shaped area of decreased CBF, even when the conventional brain scan looked normal. Increased perfusion to a tumor was frequently associated with decreased CBF in the rest of the lateral hemisphere; such a decrease could be improved by surgical removal of the tumor.

Adult↗
PubMed1975

[Regional cerebral blood flow in senile patients with meningiomas (author's transl)].

We investigated the regional cerebral blood flow of 4 meningioma patients who were all of ages over 60 years old. The average age of the patients was 68 years. Cerebral blood flow was determined by the 133Xe clearance method of Lassen and Ingvar. By extra-cranial recording of the radioactivity from the freely diffusible inert gas 133Xe, which dissolved in saline, was injected into the internal carotid artery, a clearance curve was obtained from the cerebral hemisphere. This curve could be resolved into two monoexponential clearance functions that corresponed to the flow in the grey and white matter. Graphical analysis of the original curve allowed the estimation of the relative weight of these two tissue components as well as of the mean cerebral blood flow. In three patients, regional cerebral blood flow was measured both pre- and post-operatively and these values were compared. Focal rCBF disturbances could be detected in agreement with the tumor location as verified directly or by other diagnostic procedures. That is, a relative hyperemia was detected at the areas corresponding to the tumor site. Mean fg (the flow in the grey matter) of four patients was 77.3 +/- 14.0 ml/100 g/min on the tumor areas, 48.1 +/- 6.6 ml/100 g/min on the peritumoral regions, 63.1+/- 4.1 ml/100 g/min on the non-tumoral regions. CBFr (average cerebral blood flow) of non-tumoral areas in the four patient was 36.6 +/- 2.4 ml/100 g/min and that of the peri-tumoral area, 33.1 +/- 7.9 ml/100g/min. These figures are moderately smaller than that of the normal one. A comparison between the neurological features and regional flow values noted in patients who had a removal of menigiomas indicated that the flow values of non-tumoral area increased markedly a month after operation, instead of only slight or no improvement in neurological features. Although our cases with rCBF studies are still too few to warrant conclusions, it seems that post-operative follow-up of mean cerebral blood flow changes might be rather greater help in the assessment of prognosis after operation of meningiomas than fg (the flow in the grey matter).

Aged↗
PubMed1975

Inhibition of adenosine 3',5'-monophosphate phosphodiesterase by nicotinamide and its homologues in vitro.

Inhibition of cAMP phosphodiesterase from rat liver by nicotinamide and its homologues was studied. Among the several compounds tested, such agents as nicotinamide, N2-ethylnicotinamide, N2-methylnicotinamide, N,N-diethylnicotinamide, 3-acetylpyridine, methylnicotinate, and ethylnicotinate showed potent inhibition of cAMP phosphodiesterase, with an over 90% inhibition by 5 mM ethylnicotinate when cAMP was used as substrate at a 0.48 x 10(-7) M concentration. A comparison of the inhibitory curves of theophylline, papaverine, and ethylnicotinate on enzyme activity showed them to be approximately coincident. Furthermore, the plots with abscissa of equal increments per concentration of ethylnicotinate in the presence of theophylline or papaverine coincided with that in the absence of these agents.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMedDate not supplied

Successful peripheral blood stem cell autotransplantation in a child with advanced B-cell lymphoma.

A 2-year-old boy with B-cell lymphoma (stage IV) in the first complete remission received myeloablative treatment followed by peripheral blood stem cell autotransplantation and is surviving event-free for 18 months. Reconstitution of all cell lines occurred very rapidly, ie, a level of 1000 leukocytes per microliter was reached after 9 days, that of 500 granulocytes per microliter after 10 days, and platelets were substituted only once. This result suggests that PBSCT can be safely employed during consolidation therapy for malignant disorders because of its short duration of bone marrow suppression.

Abdominal Neoplasms↗
PubMedDate not supplied

The effects of antifungal chemoprophylaxis and empiric therapy on invasive fungal infection in neutropenic children with malignant neoplasms.

Since January 1987, chemoprophylaxis and empiric therapy with antifungal drugs have been used routinely in neutropenic children with neoplasms. The incidence of terminal invasive fungal infection (IFI) diagnosed by autopsy findings is compared in two groups: group A, consisting of 25 patients autopsied between January 1982 and December 1986, and group B, consisting of 14 patients autopsied between January 1987 and December 1991. There was no difference in the incidence of IFI between the two groups, but the characteristics of IFI appeared to differ. With the recent intensification of chemotherapy, the patients in group B had more risk factors for IFI. It might therefore have been anticipated that group B patients may have shown an increase in IFI. No such increase was observed, suggesting that the prophylaxis was effective. Autopsy findings also showed that the target organs of IFI were localized and that systemic candidiasis was decreased in group B. It is thus concluded that the present antifungal countermeasures are effective, although some problems still remain.

Amphotericin B↗