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Biomedical subjects

H Kuroda

Publications and source records attributed to H Kuroda.

At least 343 records · Page 19Linked to original sources
PubMed1983

Gamma-aminobutyric acid (GABA) in cerebrospinal fluid.

Levels of gamma-aminobutyric acid (GABA) in cerebrospinal fluid (CSF) were measured by radioreceptor assay (RRA) in 25 normal controls and in 121 patients with various central nervous system disorders. CSF-GABA levels could be measured down to 5 pmoles/ml reliably by this assay. In normal controls, the mean (+/- SEM) GABA level in CSF was 127 +/- 5.2 pmoles/ml. There was no correlation between age, sex and the CSF-GABA level in normal controls. The lowest CSF-GABA level, which was 60 +/- 6.0 pmoles/ml, was observed in alcoholic patients suffering from cerebellar ataxia. The CSF-GABA levels were quite low in patients with Alzheimer's disease, late cortical cerebellar atrophy, neuro-Behçet's syndrome, olivopontocerebellar atrophy, Huntington's chorea, Parkinson's disease and cerebral hemorrhage. On the other hand, the CSF-GABA levels of meningitis patients were significantly increased. These findings suggest that measuring the CSF-GABA level is quite beneficial in the diagnosis and pathophysiological determinations of some diseases.

Adult↗
PubMed1982

Case report of a pancreatic pseudocyst ruptured into the splenic vein causing extrahepatic portal hypertension.

In a 42 year old female, a fistula developed between the splenic vein and the pancreatic duct through the cavity of a pseudocyst in the tail of the pancreas and resulted in an extrahepatic portal hypertension. The fistula was visualized by endoscopic retrograde cholangiopancreatography and percutaneous transhepatic portography, then was successfully resected by surgery. The possible etiology of extended obstruction of both splenic and portal veins in chronic pancreatitis with pseudocyst was discussed.

Adult↗
PubMed1982

Cerebrospinal fluid GABA levels in various neurological and psychiatric diseases.

Cerebrospinal fluid gamma-aminobutyric acid (CSF-GABA) was analysed by radioreceptor assay in 16 normal controls and 84 patients with various neurological and psychiatric diseases. In patients with spinocerebellar degeneration, neuro-Behçet's syndrome and Parkinson's disease, CSF-GABA levels were decreased. On the other hand, increased CSF-GABA levels were detected in patients with meningitis.

Adult↗
PubMed1982

Relation of cytoplasmic calcium to contractility in Physarum polycephalum.

In a dumbbell-shaped plasmodium of Physarum polycephalum showing active shuttle streaming Ca was precipitated with potassium pyroantimonate (K[Sb(OH)6]), and the distribution of Ca between the cytoplasm and cellular organelles, especially vacuoles, was examined by electron microscopy. The contracting half-mass, where many empty vacuoles were present, was rich in the small Ca precipitates located in the cytoplasm. The relaxing half-mass, where many Ca-containing vacuoles were present, was poor in the cytoplasmic Ca precipitates. One half-mass of a dumbbell-shaped plasmodium was treated with Ca ionophore, X-537A, and its effect on the motive force for endoplasmic streaming and the distribution of Ca was investigated. The motive force was increased by X-537A, but the period of shuttle streaming was not changed. X-537A also induced a significant increase in the number of the cytoplasmic Ca precipitates in the X-537A-treated contracting half-mass, so that the asymmetry of the distribution of cytoplasmic Ca precipitates was enhanced. A large portion of the vacuoles were empty in the contracting half-mass, and Ca-containing in the relaxing one as in the case of the untreated plasmodium.

Calcium↗
PubMed1982

Cerebrospinal fluid gamma-aminobutyric acid and homovanillic acid in depressive disorders.

gamma-Aminobutyric acid (GABA) and homovanillic acid (HVA) levels were determined in the lumbar cerebrospinal fluid (CSF) of hospitalized patients suffering from depression and in a control group. Both mean CSF GABA and HVA levels in the patients with depression were significantly lower than those of the control group (p less than 0.05, p less than 0.01, respectively). No positive correlation was found between the changes in CSF GABA and HVA levels in the patients with depression. The Hamilton Rating score in these depressed patients, age, and sex showed no correlation to CSF GABA levels. It is suggested that decreased activity in the central GABAergic and dopaminergic system may be involved in the pathogenesis of depression.

Adult↗
PubMed1981

Differentiation of agonist conformation and antagonist conformation in multiple opioid receptors.

To differentiate the opiate (naloxone) receptor and the enkephalin receptor in rat brain, we solubilized the receptor molecules by detergent and determined the molecular weights by gel filtration. The receptor preparation was bound to [3H] naloxone or [3H] Met5-enkephalin, and was solubilized by Triton X-100. On gel chromatography with a Sepharose 6B column, the agonist and the antagonist conformation of opioid receptors eluted as molecules with the molecular weights of 240,000, and 120,000 and with Stokes' radii of 5.5 nm and 4.3 nm, respectively. Further, it was also disclosed that Na+ was bound to the antagonist conformation of opioid receptors but not to the agonist conformation.

Animals↗
PubMed1981

Effects of bromocriptine on receptor binding of methionine-enkephalin.

Bromocriptine inhibited the binding of methionine-enkephalin (ENK) to rat striatal synaptic membranes in a dose-dependent fashion. The bromocriptine IC50 was 16 micrometers. hill coefficients of bromocriptine were 0.7 and 0.3, suggesting that an allosteric effect was involved in bromocriptine inhibition of ENK binding to its receptor. These data suggest that at least a part of the therapeutic antiparkinsonian effect f bromocriptine is its allosteric effects on the ENK receptor, which influences the function of striatal dopamine neurons and/or of striatal cholinergic neurons.

Animals↗
PubMed1981

Discrete regional distributions of thyrotropin releasing hormone (TRH) receptor binding in monkey central nervous system.

Thyrotropin releasing hormone (TRH) directly influences central nervous system (CNS) function, independent of its pituitary action. Although these CNS effects have been behaviorally characterized, information is not yet available on the precise regional distribution of its receptor. TRH receptor binding was examined in the monkey CNS by the radioreceptor assay for clarifying the site of TRH action. TRH was bound to brain tissue membranes via high-affinity (Kd = 5.9 x 10(-9) M) and low-affinity (Kd = 11.2 x 10(-8) M) components. TRH receptor binding varied dramatically throughout the monkey brain, with more than 40-fold variation. The limbic system contained the greatest amount of binding. The next highest areas were the cerebral cortex, hypothalamus, interpeduncular nucleus and periaqueductal gray matter of the midbrain. Receptor binding was very low or not detectable in the medial thalamus, cerebellum, brain stem, spinal cord and white matter. These data suggest that TRH has an effect on the CNS via limbic system, cerebral cortex and midbrain.

Animals↗
PubMed1981

Microfilaments around the bile canaliculi in patients with intrahepatic cholestasis.

The cytoplasmic microfilaments of hepatocytes, especially in the pericanalicular area, were examined in 25 liver biopsy specimens obtained from 15 patients with intrahepatic cholestasis. About 25 days after the onset of jaundice an increase in bile canaliculi dilation was noted, though an increase in amount of microfilaments was less conspicuous in comparison with the next stage. At about 55 days an increase in number was seen around dilated canaliculi. At about 100 days microfilaments decreased in amount and the dilation of canaliculi became less evident, while swollen microvilli protruded into the canaliculi with their microfilaments irregularly arranged. An increase of microfilaments in hepatocytes, particularly in the pericanalicular area, might be a reflection of the secretion of bile.

Adult↗
PubMed1981

Laparoscopic observation and biopsy of the pancrease.

Laparoscopy has been employed mainly in liver diseases. Although there have been many reports dealing with intraabdominal lesions other than those of the liver, there have been few concerning the pancreas. Because of its anatomical characteristics, the laparoscopic approach to the pancreas has been extremely difficult. For endoscopic diagnosis of pancreatic lesions, we have developed a 2-channel operating laparoscope. Using a supragastric approach through the lesser omentum, the scope is inserted into the lesser peritoneal sac for direct inspection of the pancreas. In this paper, the method of lesser omentotomy and the diagnostic results are described.

Biopsy↗