Search PubMed⌕ Search

Biomedical subjects

F Sakai

Publications and source records attributed to F Sakai.

At least 199 records · Page 11Linked to original sources
PubMed1979

Glucose dehydrogenase (hexose 6-phosphate dehydrogenase) and the microsomal electron transport system. Evidence supporting their possible functional relationship.

The ability of a microsomal enzyme, glucose dehydrogenase (hexose 6-phosphate dehydrogenease) to supply NADPH to the microsomal electron transport system, was investigated. Microsomes could perform oxidative demethylation of aminopyrine using microsomal glucose dehydrogenase in situ as an NADPH generator. This demethylation reaction had apparent Km values of 2.61 X 10(-5) M for NADP+, 4.93 X 10(-5) m for glucose 6-phosphate, and 2.14 X 10(-4) m for 2-deoxyglucose 6-phosphate, a synthetic substrate for glucose dehydrogenase. Phenobarbital treatment enhanced this demethylation activity more markedly than glucose dehydrogenase activity itself. Latent activity of glucose dehydrogenase in intact microsomes could be detected by using inhibitors of microsomal electron transport, i.e. carbon monoxide and p-chloromercuribenzoate (PCMB), and under anaerobic conditions. These observations indicate that in microsomes the NADPH generated by glucose dehydrogenase is immediately oxidized by NADPH-cytochrome c reductase, and that glucose dehydrogenase may be functioning to supply NADPH.

Aminopyrine N-Demethylase↗
PubMed1979

Narcolepsy: regional cerebral blood flow during sleep and wakefulness.

Serial measurements of regional cerebral blood flow were made by the 135Xe inhalation method during the early stages of sleep and wakefulness in eight normal volunteers and 12 patients with narcolepsy. Electroencephalogram, electro-oculogram, and submental electromyogram were recorded simultaneously. In normals, mean hemispheric gray matter blood flow (Fg) during stages I and II sleep was significantly less (-9.2 percent) than waking values (84.3 +/- 13 ml per 100 gm brain per minute). Maximum regional blood flow decreases during sleep occurred in the brainstem-cerebellar (-25.1 percent), right inferior temporal (-23.1 percent) and bilateral frontal (-18.9 percent) regions (p less than 0.05). In patients with narcolepsy, mean hemispheric Fg while awake was 80.5 +/- 13 ml per 100 gm brain per minute. During REM sleep (n = 2), mean hemispheric Fg increased by 9.8 percent concurrently with large increases (+34.6 percent) in brainstem-cerebellar region flow. During stages I and II sleep without REM (n = 6), there were significant increases in mean hemispheric Fg of +/-20.2 percent (p less than 0.01) and brainstem-cerebellar Fg of 38.0 percent (p less than 0.01), just the opposite of changes in normals. In narcolepsy, there appears to be a reversal of normal cerebral deactivation patterns, particularly involving the brainstem, during stages I and II sleep.

Adult↗
PubMed1979

Suppressive effect of dipyridamole on the proteinuria of aminonucleoside nephrosis in rat.

The suppressive effect of dipyridamole on the proteinuria of aminonucleoside nephrosis and protamine-induced proteinuria, was investigated. Male Wistar rats were given puromycin aminonucleoside (80 mg/kg s.c.) or protamine sulfate (20 mg/kg i.v.), and the urine was collected in metabolic cages. The content of proteins in the urine was determined by using a continuous gradient microgel electrophoresis procedure. Dipyridamole (20 mg/kg p.o.) suppressed the excretion of albumin and proteins larger than albumin (HMP) in aminonucleoside nephrosis. But the excertion of proteins smaller than albumin (LMP) was not affected by dipyridamole. Dipyridamole also suppressed the excertion of HMP in protamine-induced proteinuria, though the excretion of albumin and LMP was not affected. Puromycin aminonucleoside and protamine sulfate were known to cause renal glomerular epithelial changes referred to as "fusion" of foot processes. Since dipyridamole was effective in suppressing the both types of proteinuria, this drug was considered to improve the damaged renal glomerular barrier for plasma proteins.

Albuminuria↗
PubMed1978

[Inclusion of Gross virus cell surface associated antigen in liposomes].

The Gross virus associated cell surface antigen GCSAa was extracted from (C58NT)D cells by solubilization of membranes with detergent and partially purified. This antigen was entraped in liposomes. Absorption experiments of the cytotoxic activity towards EmaleG2 cells of a W/Fu anti (C58NT)D serum showed the presence of the antigen at the surface of sensibilized liposomes.

AKR murine leukemia virus↗
PubMed1978

Normal and abnormal patterns of cerebrovascular reserve tested by 133 Xe inhalation.

Cerebrovascular functional reserve was tested by noninvasive measurement of regional cerebral blood flow (nrCBF) at rest in quiet darkness and when repeated during standard multiple psychophysiologic activation. The test was applied to normal volunteers and patients with different neurologic disorders. The test included counting, conversation, music, and observing movements, while rCBF was measured over both cerebral hemispheres, brain stem, and cerebellum. In normal persons at rest, mean gray matter flow (Fg) values were the same for each hemisphere. Highest Fg values were observed in brain stem and both frontal regions. During activation in normal persons, there was a significant increase in Fg values over both hemispheres and in brain stem. During activation, three types of abnormal rCBF responses were seen: Demented patients showed no change, patients with vascular occlusion showed little or no increase over the ischemic hemisphere, and some patients with epilepsy showed excessive increases.

Adolescent↗
PubMed1978

Increases in steroid binding globulins induced by tamoxifen in patients with carcinoma of the breast.

The effects of tamoxifen on cortisol binding globulin (CBG) and sex hormone binding globulin (SHBG) were studied in 25 women and one man with breast cancer. These patients were in various endocrine states according to age (15 post-menopausal women) or previous endocrine surgery (ovariectomy, two patients; ovariectomy plus adrenal surgery, five patients; hypophysectomy, three patients; ovariectomy plus hypophysectomy, two patients). The administration of tamoxifen (20-40 mg/day) resulted in increases in the level of CBG in all patients (mean rise in binding capacity 10.8 microgram cortisol/100 ml plasma) and in the level of SHBG in 21 patients (mean rise in binding capacity 0.79 microgram dihydrotestosterone/100 ml plasma for all patients). These increases were positively correlated. They were not associated with any alteration in the association constants of the steroid binding globulins. The effect of tamoxifen on CBG diminished with increasing age. The changes in the levels of CBG and SHBG were independent of the endocrinological state of the patient. It is inferred that tamoxifen has a direct oestrogen-like action on the liver which results in increased production of CBG and SHBG. Tamoxifen therapy for carcinoma of the breast appeared to be least effective in those patients in whom the drug caused the highest increase in the concentration of CBG.

Adult↗
PubMed1978

Quantitative analysis of electrophoretically separated proteins using Coomassie blue.

Electrophoresis of 125I-labelled rat albumin from 0.5 to 700 ng was performed with a 5 microliter capillary tube in which 4-40% continuous gradient polyacrylamide gel was prepared. The linear relationship was obtained by using double logarithm plots between protein amounts and densitometric areas of the protein bands stained with Coomassie blue. The radioactivities of the same gels and the protein amounts were also shown to be linear. In the case of rat gamma-globulin, the linear relationship was also obtained. As an applied example of this method, the urinary gamma-globulin excretion showed marked changes caused by the circadian rhythm in rats.

Albuminuria↗
PubMed1976

Serum dopamine-beta-hydroxylase activity in migraine.

Serum dopamine-beta-hydroxylase (DBH) activity was measured during headache-free intervals in 17 patients with migraine and during the headache interval in 16 patients with muscle contraction headache, as well as in 40 normal subjects. The DBH activity was significantly higher in the migraine patients (46.5+/4.5 units) than in the controls (24.9+/2.4 units), whereas no significant difference was observed between the patients with muscle contraction headache (29.4+/4.5 units) and the controls.

Adult↗