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Biomedical subjects

F Sakai

Publications and source records attributed to F Sakai.

At least 145 records · Page 8Linked to original sources
PubMed1988

Schwannoma of the lesser omentum.

A case of solitary benign schwannoma of the omentum is detected by CT, ultrasonography and angiography, as a solid mass containing cystic regions.

Angiography↗
PubMed1987

Three-dimensional mapping of local cerebral perfusion in alcoholic encephalopathy with and without Wernicke-Korsakoff syndrome.

Seventeen severe chronic alcoholic patients with and without Wernicke-Korsakoff syndrome (WKS) were examined prospectively after being treated by withdrawal from alcohol. The WKS patients also received thiamine supplements. Three-dimensional measurements of local cerebral blood flow (LCBF) and local partition coefficients (L lambda) were made utilizing xenon contrast computed tomography (Xe CT-CBF). Results were displayed as color-coded brain maps before and after treatment and these were correlated with neurological and cognitive examinations. Before treatment chronic alcoholics without WKS (n = 10) showed diffuse reductions of LCBF values throughout all gray matter including hypothalamus, vicinity of nucleus basalis of Meynert, thalamus, and basal ganglia. Similar, but more severe, reductions were seen in patients with WKS (n = 7), however, white matter perfusion was also reduced. In WKS, most prominent reductions of LCBF were also seen in hypothalamus and basal forebrain nuclei but thalamus, basal ganglia, and limbic systems were severely reduced. After treatment, both groups with alcoholic encephalopathy showed marked clinical improvement and cerebral perfusion was restored toward normal. Chronic alcohol abuse, in the absence of thiamine deficiency, reduces CBF by direct neurotoxic effects. If thiamine deficiency is also present, more severe and localized hemodynamic reductions are superimposed.

Adult↗
PubMed1987

Experimental autoimmune dacryoadenitis. II. Harderian gland disease in the rat.

Experimental autoimmune dacryoadenitis was induced in 100% of Lewis rats by immunization with a KCl extract of Harderian gland in complete Freund's adjuvant (CFA), providing that the animals had received simultaneously i.v. injection of killed Bordetella pertussis. No significant pathological changes in the Harderian gland were observed in control animals immunized with KCl extracts of lacrimal or salivary glands. Gel filtration of the KCl extract on Sephacryl S-300 column yielded three protein fractions. Fraction II (MW = 50-100K) induced severe Harderian gland disease following a single injection of 2.0 mg protein in CFA plus pertussis. The initial lesions consisted of multiple focal infiltrates of mononuclear cells. Later, the inflammatory process assumed a more granulomatous form, with significant contribution by epithelioid and giant cells. In contrast, Lewis rats immunized with Harderian gland fractions I or III proteins, or with extracts of lacrimal or salivary gland, showed little or no inflammatory lesions. These data suggest that Harderian gland contains unique tissue-specific autoantigen(s) capable of inducing autoimmune granulomatous dacryoadenitis in the rat.

Animals↗
PubMed1985

Regional cerebral blood volume and hematocrit measured in normal human volunteers by single-photon emission computed tomography.

Single-photon emission computed tomography (SPECT) was used for the measurement of regional cerebral blood volume (CBV) and hematocrit (Hct) in normal healthy human volunteers (mean age 30 +/- 8 years). Regional cerebral red blood cell (RBC) volume and plasma volume were determined separately and their responses to carbon dioxide were investigated. Ten right-handed healthy volunteers were the subjects studied. SPECT scans were performed following intravenous injection of the RBC tracer (99mTc-labeled RBC) and plasma tracer (99mTc-labeled human serum albumin) with an interval of 48 h. Regional cerebral Hct was calculated as the regional ratio between RBC and plasma volumes and then was used for calculating CBV. Mean regional CBV in the resting state was 4.81 +/- 0.37 ml/100 g brain, significantly greater in the left hemisphere compared with the right by 3.8% (p less than 0.01). Mean regional RBC volumes (1.50 +/- 0.09 ml/100 g brain) were less than mean regional plasma volumes (3.34 +/- 0.28 ml/100 g brain), and mean regional cerebral Hcts were 31.3 +/- 1.8%, which was 75.9 +/- 2.1% of the large-vessel Hct. During 5% CO2 inhalation, increases in plasma volume (2.48 +/- 0.82%/mmHg PaCO2) were significantly greater than for RBC volume (1.46 +/- 0.48%/mmHg PaCO2). Consequently, the cerebral-to-large-vessel Hct ratio was reduced to 72.4 +/- 2.2%. Results emphasize the importance of cerebral Hct for the measurement of CBV and indicate that regional cerebral Hcts are not constant when shifted from one physiological state to another.

Adult↗
PubMed1983

Narcotic physical dependence and urinary sex-dependent low molecular weight proteins in male rats.

The relationship between urinary excretion of sex-dependent low molecular weight proteins (LMWP) in male rats and narcotic dependence is described in this study. Rats were intermittently infused with narcotics at one hour intervals through an implanted intravenous cannula. Development of physical dependence on morphine, pethidine, and pentazocine was detected by withdrawal signs including body weight loss and abnormal behaviors after naloxone challenge. In these animals, a significant decrease in urinary LMWP excretion was found following the second day of each drug treatment without significant changes in albumin excretion, and this decrease was observed continuously throughout the experiment. The markedly decreased level of LMWP recovered to the control level within 7 d after withdrawal of the drugs. These results suggest that the decrease in urinary excretion of sex-dependent LMWP in male rats is a phenomenon closely related to narcotic dependence.

Animals↗
PubMed1983

A new approach for assessment of narcotic physical dependence using urinary sex-dependent low molecular weight proteins in male rats.

Attempts have been made to examine the relationship between urinary excretion of sex-dependent low molecular weight proteins found only in male rats (LMWP) and morphine physical dependence. Chronic administration of morphine produced a dose-related decrease in urinary LMWP excretion, which was correlated to the intensity of withdrawal signs including body weight loss and abnormal behaviors recognized after naloxone challenge. Furthermore, a statistically high correlation was obtained between the decrease in urinary LMWP excretion and the loss of body weight precipitated by naloxone challenge. LMWP was identified immunologically in the livers, kidneys, and sera using an antibody against purified LMWP. The serum level of LMWP was increased rapidly following bilateral nephrectomy. After chronic treatment with morphine, the LMWP content in the livers, kidneys, and sera were decreased. These findings indicate that the decrease in urinary LMWP excretion induced by chronic administration of morphine can be a useful parameter to assess the development of physical dependence on narcotics on the peripheral level without requiring drug withdrawal and naloxone challenge. This decrease in urinary LMWP may be caused by the inhibition of LMWP synthesis in the liver.

Animals↗
PubMed1983

Effects of starvation on microsomal cytochrome P-450 and laurate-omega-hydroxylation of rat kidney and liver.

Cytochrome P-450 (P-450) content and laurate-omega-oxidation activity in rat kidney and liver microsomes were investigated following starvation. Multiple forms of P-450 were analyzed by one dimensional separation using peroxidase stained SDS-continuous gradient polyacrylamide gel electrophoresis. Gels of the hepatic microsomes treated with phenobarbital showed three P-450 bands, and the renal microsomes showed one sharp band, which was induced remarkably by starvation and coincided with the middle molecular form of P-450 from the hepatic microsomes. Since laurate-omega-oxidation activity was induced specifically by starvation but not by drug treatment, in both the kidney and the liver microsomes, the middle molecular form of P-450 might catalyze laurate-omega-oxidation. It seemed, therefore, that a special P-450 subunit catalyzing laurate-omega-oxidation has a greater function in the renal rather than hepatic microsomes because the specific laurate-omega-oxidation activity per starvation induced P-450 content was relatively similar in both the kidney and the liver.

Animals↗
PubMed1983

[Relationship between the decrease in urinary sex-dependent low molecular weight proteins by morphine and hormonal parameters in male rats].

The relationship between the decrease in urinary sex-dependent low molecular weight proteins (LMWP), which exist only in the male rat, and the serum levels of some hormones were examined in this study. Castration of male rats reduced the urinary excretion of LMWP by about 50%. Replacement therapy with testosterone increased the urinary LMWP excretion. Adrenalectomy did not affect the urinary excretion of LMWP. In the adrenalectomized rat, however, corticosterone increased LMWP excretion. Therefore, it is considered that testosterone and corticosterone play a part in the urinary excretion of LMWP under physiological conditions and that the effect of testosterone is more specific than that of corticosterone. Serum concentration of testosterone and corticosterone tended to increase in comparison with the control on the 7th day after chronic treatment with morphine (0.5 mg/g food), when the urinary excretion of LMWP was significantly decreased. Furthermore, after rats were chronically administered morphine following castration or adrenalectomy, the urinary LMWP excretion was markedly decreased in the same way as found in intact animals. On the other hand, the serum thyroxine level of rats treated with morphine for 7 days was significantly lower than that of the control. Thyroxine increased dose-dependently the decreased urinary excretion of LMWP induced by morphine administration. These findings suggest that the decrease in urinary excretion of LMWP after chronic treatment with morphine may be caused by the change of serum thyroxine level via the action of morphine on the endocrine functions.

Adrenalectomy↗