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Biomedical subjects

H Yokoo

Publications and source records attributed to H Yokoo.

At least 145 records · Page 8Linked to original sources
PubMed1984

Serotonin and 5-hydroxyindoleacetic acid concentrations in individual hypothalamic nuclei and other brain areas of rat.

Serotonin and 5-hydroxyindoleacetic acid (5-HIAA) were measured in individual nuclei of rat hypothalamus and other brain areas using HPLC with electrochemical detection. 5-HIAA levels were first demonstrated in hypothalamic and some discrete brain areas. The 5-HIAA/5-HT ratio was highest in the n. caudatus putamen, high in the n. ventromedialis and lowest in the n. suprachiasmaticus.

Animals↗
PubMed1984

Ultrastructural survey and tissue analysis of human livers after a 6-month course of etretinate.

A prospective study of the histology and ultrastructure of liver biopsies and analysis of liver tissue for retinoid was performed in twenty psoriasis patients treated with etretinate for 6 months. Nonspecific ultrastructural changes were noted in several liver specimens. Etretinate was detected in all samples. We find no significant hepatotoxicity after a 6 month course of etretinate. Body fat is probably a more important site than the liver for storage of etretinate.

Adult↗
PubMed1983

Differential effects of acute and chronic administration of haloperidol on homovanillic acid levels in discrete dopaminergic areas of rat brain.

After acute administration of haloperidol, homovanillic acid (HVA) levels were increased in the prefrontal cortex, anterior cingulate cortex, discrete limbic areas and A14 dopamine (DA) neurons. The maximal effect of haloperidol was attained more slowly in the prefrontal cortex and amygdala than in the other regions. The ED50 of haloperidol was 0.03 mg/kg in the prefrontal cortex, but was 0.06-0.07 mg/kg in other areas examined. After repeated administration of haloperidol, tolerance to the HVA increase was observed in the striatum and all limbic areas examined, the amygdala being the most susceptible to this tolerance. In contrast, no tolerance was found in the anteromedial and suprarhinal DA neurons of the prefrontal cortex and A14 DA neurons. These results suggest that the prefrontal cortex may be a possible site for the antipsychotic action of haloperidol. On the other hand, no change of HVA levels in the A12 and A13 DA neurons of the hypothalamus was observed after haloperidol treatments, suggesting a lack of neuronal feedback mechanism in the A12 and A13 DA neurons.

Animals↗
PubMed1983

Dopamine, serotonin and alpha-adrenergic receptor blocking activities in serum and their relationships to prolactin level in schizophrenic patients receiving long-term chlorpromazine treatment.

The clinical application of a dopamine radioreceptor assay for neuroleptics has been proposed. Simultaneous monitoring of serum antidopaminergic (anti-DA), antiserotonergic (anti-5HT) antiadrenergic (anti-NA) activities may provide a better understanding of clinical effects of neuroleptics. Serum anti-DA and anti-5HT activities were estimated by competition for 3H-spiperone binding to dopamine and serotonin receptors in rat brain, respectively, and anti-NA activity by competition for 3H-WB-4101 binding to alpha-receptors. Thirty-one patients receiving maintenance doses of chlorpromazine (CPZ) chronically were studied. Serum activities varied among patients receiving the same dose, but correlated significantly with dose. Anti-DA activity also correlated with both anti-5HT anti-NA activities, and the average ratio of anti-5HT or anti-NA to anti-DA activity was slightly reduced by metabolism of CPZ. However, some patients had a different spectrum of serum activities from that of in vitro activities. Serum prolactin (PRL) correlated weakly with all the serum activities. The serum PRL anti-DA activity ratio appeared to be independent of anti-5HT or anti-NA activity, suggesting the predominant involvement of anti-DA activity in the stimulation of PRL release.

Adrenergic alpha-Antagonists↗
PubMed1983

Heterotopic pancreas mimicking carcinoma of the head of the pancreas: a rare cause of obstructive jaundice.

A 61-year-old man developed obstructive jaundice and had ultrasonographic and cholangiopancreatographic findings consistent with carcinoma of the pancreas. However, pathologically the obstruction proved to be from heterotopic pancreatic tissue compressing the common bile duct. This patient and eight previously reported patients with a similar problem are the subjects of this report.

Adult↗
PubMed1983

Bile pulmonary embolism: report of a case and a review of the literature.

Bile emboli were found at autopsy in the small pulmonary arteries of a 68-year-old man with a past history of polyposis coli who had required percutaneous transhepatic drainage of his biliary tree because of an obstructing ampullary carcinoma. A communication between the biliary tract and a hepatic vein was shown to be due to the catheter. Eight previously reported cases of bile pulmonary emboli have been found. All but one had a clear history of hepatic trauma or intrahepatic abscess. Bile pulmonary embolism is a rare, occasionally fatal, complication of fistulous communication between the biliary tree and the hepatic venous system.

Aged↗
PubMed1982

A study of potential hepatotoxicity of etretinate used in the treatment of psoriasis.

Etretinate was used to treat twenty patients who had severe, disabling psoriasis and an increased risk of liver damage. Potential hepatotoxicity was evaluated by obtaining liver biopsies prior to starting therapy and after a 6-month course on a dosage of 0.75 mg/kg/day. In comparing pretreatment biopsies to posttreatment biopsies, five of twenty patients demonstrated a morphologic change in their liver. Three showed progressive fatty metamorphosis, and two showed liver cell necrosis and progressive fibrosis. One of these was due to heavy alcohol intake. Based on our 6-month evaluation, etretinate does not produce a consistent toxic effect on the liver.

Adult↗
PubMed1982

Experimental production of Mallory bodies in mice by diet containing 3,5-diethoxycarbonyl-1,4-dihydrocollidine.

The first experimental production of Mallory bodies was reported by Denk et al. in 1975 in mice fed griseofulvin. We discovered a second chemical capable of producing Mallory bodies in the mouse liver in a manner similar to griseofulvin. Male Swiss albino mice were fed a powdered standard diet containing 2.5% of 3,5-diethoxycarbonyl-1,4-dihydrocollidine up to 95 days. The animals were killed at intervals and their livers were examined by light and electron microscopy. In general, the morphologic changes in the liver were similar to, but more marked than, those seen in griseofulvin-fed mice. Mallory bodies were first observed in the livers of mice killed at 40 days. In our previous experiment using griseofulvin, we first observed Mallory bodies in mice killed at 61 days. These observations suggest that 3,5-diethoxycarbonyl-1,4-dihydrocollidine may be more effective than griseofulvin in the production of Mallory bodies in mice.

Animals↗
PubMed1980

Severe hepatocellular reaction resembling alcoholic hepatitis with cirrhosis after massive small bowel resection and prolonged total parenteral nutrition.

A middle-aged man is described who developed a severe liver disease resembling alcoholic hepatitis which occurred after prolonged total parenteral nutrition for a severe short bowel syndrome. His nutrition was well maintained in terms of biochemical parameters, suggesting that the liver disease was not mediated by a nutritional deficit.

Fatty Acids, Essential↗
PubMed1979

Cytomegalovirus granulomatous hepatitis.

Three patients with granulomatous hepatitis due to cytomegalovirus are described. They are compared to the three previously described patients with this disease, and their clinical and serologic characteristics are discussed. Similarities and differences between infectious mononucleosis (Epstein-Barr virus) and cytomegalovirus infections are adduced. That cytomegalovirus may be a cause of granulomatous hepatitis in the adult is stressed.

Adult↗
PubMed1979

Griseofulvin-induced cholestasis in Swiss albino mice.

Griseofulvin was fed to male Swiss albino mice, which were sacrificed at varying times after the initiation of the feeding. The following were compared with mice fed a control diet: hepatic histology, hepatic weight, plasma glycocholate, glycolithocholate, cholesterol, bilirubin, and alkaline phosphatase. Concurrent with the development of hepatic protoporphyria, a progressive cholestatic lesion was produced with marked bile canalicular dilatation and elevation of the plasma bile salts, alkaline phosphatase, and cholesterol without a rise in bilirubin. Adaptation to the cholestatic injury occurred in about 60 days despite continued griseofulvin feeding. This was evidenced by decreased values in the biochemical profile with concomitant improvement in the bile canalicular morphology. Following this event of adaptation, Mallory bodies began to appear in the livers, often in the periphery of the hepatic lobule. This model may be useful in studying mechanisms of cholestasis, Mallory body formation, and their relationship to altered microtubular systems in the hepatocyte.

Alkaline Phosphatase↗
PubMed1979

Effect of diuretics on ADP incorporation in kidney mitochondria.

The effect of diuretics on incorporation of ADP in mitochondria isolated from rabbit renal cortex and medulla was examined. Inhibition of incorporation of [14 C]ADP into both types of mitochondria was observed following pretreatment with furosemide, ethacrynic acid and meralluride at high drug concentrations (7.5 x 10-4 M furosemide and ethacrynic acid, 6.4 x 10-3 M meralluride). At lower concentrations (7.5 x 10-5 M furosemide and ethacrynic acid, 6.4 x 10-4 M meralluride), only entry of ADP in medullary mitochondria was inhibited. Chlorothiazide, 1.7 x 10-3 M, did not inhibit incorporation of ADP into either mitochondrial preparation. Atractyloside, a classic inhibitor of ADP-ATP exchange, showed inhibition in both preparations. Furosemide, injected in vivo inhibited incorporation of ADP into medullary but not cortical mitochondria. These results are consistent with the possibility that loop diuretics may reduce tubular sodium reabsorption by inhibiting ADP-ATP exchange across the mitochondrial membrane, thereby depriving active transport processes of ATP. The differential action on cortical and medullary mitochondria by loop diuretics is consistent with their predominant site of action in the tubule and with the different morphologic characteristics of both types of mitochondria.

Adenosine Diphosphate↗
PubMed1979

Pseudosarcoma of the esophagus. Three new cases and review of the literature.

Three newly found patients with an esophageal pseudosarcoma are described. The features of this unusual polypoid tumor are reviewed based on these three patients and 21 additional reported patients. The origin of the sarcomatous element as a metaplastic reaction to the underlying carcinoma is discussed. The exuberant growth may present with obstructive symptoms earlier than the usual carcinoma of the esophagus, permitting curative surgical resection in some patients.

Aged↗