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Biomedical subjects

A Kishimoto

Publications and source records attributed to A Kishimoto.

At least 73 records · Page 4Linked to original sources
PubMed1988

Treatment of depression with clonazepam.

The antidepressive effect of an anticonvulsant clonazepam was studied with maximum daily dose of 1.5 to 6.0 mg (mean 3.4 mg) in 27 patients with major depression (n = 18) or bipolar disorder (n = 9). Two of them dropped out at an early stage of the treatment, and the antidepressive effect of clonazepam was evaluated for the remaining 25 patients. A marked to moderate improvement was obtained for 21 patients (84%), and the onset of the antidepressive effect of clonazepam appeared within 1 week in most of the cases who responded to the therapy. The total scores on the Hamilton Depression Rating Scale and the Beck Self-Rating Scale were significantly reduced after the clonazepam treatment. Side effects occurred in 14 patients, but most of them were not severe. From these results, it is thought that clonazepam might be useful as an antidepressant for patients in whom conventional antidepressant treatment are contraindicated.

Adult↗
PubMed1988

Treatment of periodic depression with carbamazepine.

A case of periodic depression treated prophylactically with carbamazepine for over 10 years is reported. Recurrence of depressive episode was completely inhibited during the carbamazepine treatment and depressive relapses occurred 2 to 4 months after the discontinuation of carbamazepine treatment. No notable side effect was found during the treatment.

Carbamazepine↗
PubMed1988

Oxidative Pathway from Squalene to Geranylacetone in Arthrobacter sp. Strain Y-11.

The reaction pathway from squalene to trans-geranylacetone in Arthrobacter sp. strain Y-11 was studied. The enzyme or enzymes catalyzing squalene degradation were found to be membrane bound. Stoichiometric analysis of a cell-free system revealed that the ratio of squalene to trans-geranylacetone changed from 1:2 to 1:1 as the reaction proceeded, indicating two steps in geranylacetone formation. The initial step was found to be oxygenase catalyzed, from the absolute requirement for molecular oxygen in geranylacetone formation and the incorporation of O into geranylacetone under O(2) atmosphere. By using [H]squalene as the substrate, we detected an intermediate in the pathway and identified it as 5,9,13-trimethyltetradeca-4,8,12-trienoic acid by mass spectrometry, infrared spectrometry, nuclear magnetic resonance spectrometry, and chemical synthesis. We deduced that squalene was first oxidatively cleaved to geranylacetone and the intermediate, and that the intermediate was further metabolized to geranylacetone. We also synthesized some of the presumptive metabolites, such as 4,8,12-trimethyltrideca-4,8,12-trien-2-one, and confirmed that they served as active precursors for geranylacetone formation. Based on these lines of evidence, we present here the pathway from squalene to trans-geranylacetone in Arthrobacter sp. strain Y-11.

Journal Article↗
PubMed1988

Calcium-independent activation of hypothalamic type I protein kinase C by unsaturated fatty acids.

Among multiple subspecies of the protein kinase C (PKC) family, type I PKC from the hypothalamus, having the structure related to the gamma-sequence, responds to low concentrations of arachidonic acid to exhibit marked enzymatic activity. This mode of activation does not require elevated Ca2+ levels, nor does it depend on diacylglycerol and phospholipid. Type I PKC is expressed only in limited regions of central nervous tissues, such as the hypothalamus. This PKC subspecies is not detected in the pituitary gland. The results suggest that the activation of type I PKC may not always be directly associated with inositol phospholipid hydrolysis, and that this subspecies may play a role in the modulation of specialized functions of the hypothalamus.

Animals↗
PubMed1987

Purification of catalytic subunit of low density lipoprotein receptor kinase and identification of heat-stable activator protein.

Bovine adrenal cortex contains a high molecular weight casein kinase II-like enzyme (Mr 500,000) that phosphorylates a specific serine residue in the cytoplasmic domain of the low density lipoprotein (LDL) receptor (Kishimoto, A., Brown, M. S., Slaughter, C. A., and Goldstein, J. L. (1987) J Biol. Chem. 262, 1344-1351). In the current paper, we provide evidence to suggest that this 500-kDa kinase can be dissociated into two subunits, a catalytic subunit and an activator subunit, by treatment with 1 M NaCl. The catalytic subunit was purified to homogeneity (greater than 100,000-fold) using affinity chromatography on GTP-agarose plus several other chromatography steps. It had an Mr of 50,000 by gel filtration and 35,000 by polyacrylamide gel electrophoresis in sodium dodecyl sulfate. The catalytic subunit phosphorylated casein actively, but it phosphorylated the LDL receptor with only low affinity. The affinity for the LDL receptor was increased 10-fold (saturation at 10 nM LDL receptor) by addition of a second protein that was released from a high molecular weight 500-kDa complex by 1 M NaCl. This activator protein (Mr 120,000 by gel filtration) was extremely heat stable but was destroyed by trypsin. It appeared to be required in stoichiometric amounts with relation to the LDL receptor. It did not increase the ability of the 50-kDa subunit to phosphorylate casein nor did it activate phosphorylation of the LDL receptor or casein by classic casein kinase II. The current data raise the possibility that the specificity of the 500-kDa LDL receptor kinase is attributable to a heat-stable activator subunit that binds to the LDL receptor and thereby renders it a better substrate for the catalytic subunit of the kinase.

Adrenal Cortex↗
PubMed1987

Phosphorylation of serine 833 in cytoplasmic domain of low density lipoprotein receptor by a high molecular weight enzyme resembling casein kinase II.

A soluble protein kinase that phosphorylates the last serine residue (Ser-833) in the cytoplasmic domain of the low density lipoprotein (LDL) receptor was purified about 1300-fold from the cytosol of bovine adrenal cortex. The LDL receptor kinase shared several properties with casein kinase II: use of either GTP or ATP; phosphorylation of a typical casein kinase II recognition sequence in the LDL receptor (a serine followed by a cluster of three negatively charged amino acids); and inhibition by heparin. The LDL receptor kinase differed from classic casein kinase II in the following respects: its apparent molecular weight on gel filtration was approximately 500,000 as opposed to the usual molecular weight of 130,000 for casein kinase II; its affinity for the LDL receptor (apparent Km approximately 5 nM) was much greater than its affinity for casein (approximately 10 microM); and its activity was inhibited by polylysine, an agent that stimulates casein kinase II. The physiologic role of this unusual kinase, if any, is unknown.

Adenosine Triphosphate↗
PubMed1987

Simultaneous pleomorphic adenomas of the right parotid and ipsilateral submandibular glands.

A case of simultaneous pleomorphic adenomas of the right parotid and ipsilateral submandibular glands was reported. The patient was a 68-year-old woman who had a ten-year history of an otherwise asymptomatic non-enlarging mass in the parotid gland and a slowly enlarging mass in the submandibular gland. Microscopically, the parotid tumor consisted of predominant spindle-shaped cell proliferations with myxoid stroma in places. The submandibular gland tumor showed tubular and trabecular formations with stroma consisting of hyalinized fibrous connective tissues. Simultaneous pleomorphic adenomas in the salivary glands are so rare that only 23 cases can be found in the literature. Additionally, only five tumors occurring simultaneously in the parotid and submandibular glands are reported in the literature. Our case seems to be the sixth of simultaneous pleomorphic adenomas of the parotid and submandibular glands.

Adenoma↗
PubMed1987

Clinical pharmacology of a new antidepressant, Y-8894 in healthy young and elderly volunteers.

In the first experiment the influences of a single oral administration of a new antidepressant, Y-8894 50 mg, nortriptyline 50 mg, and placebo on physiological and psychological parameters were evaluated by a double-blind, crossover method in 10 healthy male volunteers. As the second experiment eight elderly healthy men were also recruited to examine the clinical pharmacology of Y-8894. Y-8894 50 mg showed no significant anticholinergic, sedative, or cardiovascular effect on any of the measures used in young subjects. In the elderly Y-8894 50 mg increased pulse rate (P less than 0.05-0.01), lowered systolic blood pressure (P less than 0.05-0.005), and decreased salivary flow (P less than 0.05) compared with those of pre-drug baseline. C.f.f. was improved after Y-8894 50 mg, but not significantly. Neither psychomotor performance nor immediate memory was influenced after either treatment in young subjects. Furthermore, in the elderly Y-8894 50 mg did not affect these parameters. In the elderly both k21 and ke were smaller, t1/2,z was longer, and AUC was larger compared with young subjects (P less than 0.01). In conclusion, Y-8894 50 mg seemed to lack the anticholinergic, sedative and cardiovascular effects which were observed after nortriptyline 50 mg in young subjects. In the elderly some affects were recognized, in part, due to pharmacokinetic alteration.

Adult↗
PubMed1987

Comparative study of the effects of 9 antidepressants on several physiological parameters in healthy volunteers.

Effects on physiological parameters were compared among 9 antidepressants (amitriptyline 50 mg, imipramine 50 mg, nortriptyline 50 mg, amoxapine 50 mg, maprotiline 50 mg, mianserin 20 mg, zimelidine 100 mg, nomifensine 50 mg, and Y-8894 50 mg) after a single oral administration in healthy volunteers. Critical fusion frequency of flicker, body sway distance, salivary flow rate, near blurred point, and pulse rate were employed as parameters. The degree of the drug effects on the physiological parameters could be roughly classified into two to four groups according to maximum percent deviation of each parameter.

Adult↗
PubMed1986

A calcium-protease activator associated with brain microsomal-insoluble elements.

A factor which markedly activates Ca2+-dependent thiol protease (calpain) is associated with Triton X-100-insoluble materials, presumably structural elements such as cytoskeletons, of bovine brain microsomal fraction. This factor is extracted with 0.6 M KC1, and purified partially by sucrose density gradient centrifugation and hydroxyapatite column chromatography. The factor appears to be a heat-stable protein with an approximate Mr of 15 000. With casein as substrate this factor activates both calpain I and calpain II several-fold up to more than 10- fold without alteration of their affinity to Ca2+. Calmodulin is unable to substitute for this factor. A similar factor is associated with human platelet insoluble materials.

Animals↗
PubMed1986

Role of protein kinase C in calcium-mediated signal transduction.

Information from certain extracellular signals, including a group of peptide hormones and some neurotransmitters, appears to flow from the cell surface into the cell interior through two pathways, protein kinase C activation and Ca2+ mobilization, both of which become available by a single ligand-receptor interaction. Under normal conditions protein kinase C is activated by association with membrane phospholipids in the presence of 1,2-diacylglycerol. This diacylglycerol may arise in the membrane only transiently from the receptor-mediated hydrolysis of inositol phospholipids. By using a synthetic permeable diacylglycerol or tumour-promoting phorbol ester (as a substitute for active diacylglycerol) it has been shown that signal passage through this protein kinase pathway is an essential prerequisite, often synergistic to that via the Ca2+ pathway, for full physiological responses, such as transmitter release and exocytosis, to be obtained. Presumably, such a role of protein kinase C may be extrapolated to the activation of many other cellular processes, including membrane conductance, gene expression and some metabolic reactions, as well as to the modulation of other receptor-mediated signal pathways. Some morphological findings with monoclonal antibodies raised against protein kinase C are presented.

Animals↗
PubMed1986

Chromosome examination of patients under lithium therapy.

The chromosomal aberrations of 13 patients who had received continuous lithium therapy for affective disorders were examined. Healthy college women were used as controls. There was a high frequency in gaps among the patients compared with the controls, but there was no significant difference between them. Although there was a significant relationship between the age of patients and the incidence of abnormal cells, there was no relationship between the duration of lithium therapy and the incidence of abnormal cells. These results suggest that lithium carbonate has neither the suppression effect of chromosomal repair mechanisms nor mutagenic activity. In order to discuss the teratogenicity of lithium salts on human beings, it seems necessary to conduct chromosome examinations of babies born to lithium-treated women.

Adult↗