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Biomedical subjects

K Tanimoto

Publications and source records attributed to K Tanimoto.

At least 235 records · Page 13Linked to original sources
PubMed1987

PCP-induced alterations in cerebral glucose utilization in rat brain: blockade by metaphit, a PCP-receptor-acylating agent.

The effects of phencyclidine (PCP) on regional cerebral glucose utilization was determined by using quantitative autoradiography with [14C]-2-deoxyglucose. PCP increased brain metabolism in selected areas of cortex, particularly limbic, and in the basal ganglia and thalamus, whereas the drug decreased metabolism in areas related to audition. These results are consistent with the known physiology of central PCP neurons and may help to suggest brain areas involved in PCP-mediated actions. Moreover, based on the behavioral similarities between PCP psychosis and an acute schizophrenic episode, these data may be relevant to the understanding of schizophrenia. The PCP-receptor-acylating agent, metaphit, blocked most of these PCP actions. In addition, metaphit by itself was found to diminish glucose utilization rather uniformly throughout brain. These results indicate an antagonist effect of metaphit on the PCP system and suggest a widespread action of metaphit, putatively at a PCP-related site, possibly in connection with the N-methyl-D-aspartate (NMDA) receptor.

Acylation↗
PubMed1987

Destruction of cultured vascular endothelial cells and red blood cells by immune-activated polymorphonuclear leukocytes.

The cytotoxicity of human polymorphonuclear leukocytes (PMNs) against autologous red blood cells (RBC) and cultured vascular endothelial cells (EC) was investigated. PMNs were activated by phorbol myristate acetate (PMA) together with immune stimuli such as immune complexes and aggregated IgG. In the standard 51Cr-release assay, in which PMA concentration was 5 ng/ml and effector versus target ratio was 5, 76.7% and 34.2% specific 51Cr release was observed from RBC and EC, respectively. Significant levels of 51Cr were released, albeit to a lesser degree, when PMNs were stimulated by immune stimuli. Further experiments which employed various scavengers of oxygen radicals suggested that hydrogen peroxide was the most potent mediator of this cytotoxicity; the implications of these in vitro observations with the pathogenesis of immune vasculitis are of clinical interest.

Antigen-Antibody Complex↗
PubMed1987

Digital image processing of dentomaxillofacial radiographs.

The improvement in the image quality of dentomaxillofacial radiographs (panoramic radiographs) with the use of a digital image-processing system was examined. Linear and nonlinear unsharp masking techniques were employed for image processing. The quality of the processed images was found to be markedly improved over that in original radiographs. The detail visibility of linearly enhanced images, especially in low-density areas, was superior to that of nonlinearly enhanced images, although the presence of more artifacts and more noise was noted in linearly enhanced images. Radiographic diagnosis in the dentomaxillofacial region can be improved with this system.

Humans↗
PubMed1987

Plasma amino acid patterns in hepatocellular carcinoma.

Plasma amino acid levels were determined in 23 patients in comparison with 16 normal subjects and 17 patients with liver cirrhosis. Patients with hepatocellular carcinoma had elevated levels of the aromatic amino acids and lowered levels of the branched-chain amino acids, as seen in liver cirrhosis; however, they had lowered levels of alanine and glutamine as compared with normal subjects and with liver cirrhosis patients. Following treatment with intraarterial chemotherapy and/or transcatheter arterial embolization, plasma levels of alanine and glutamine recovered. These results suggest that the consumption of alanine and glutamine increase in hepatocellular carcinoma.

Adult↗
PubMed1987

Abnormal growth hormone release following luteinizing hormone releasing hormone in anorexia nervosa.

We studied the luteinizing hormone (LH), follicle stimulating hormone (FSH) and growth hormone (GH) secretion following an i.v. injection of 0.1 mg of luteinizing hormone releasing hormone (LHRH) in patients with anorexia nervosa, who showed the GH secretion after thyrotropin releasing hormone (TRH). Five out of 11 patients had an elevated plasma GH level in a fasting state. The administration of LHRH resulted in a significant increase in the plasma GH concentrations in 3 of the 11 patients. Three other patients also showed an elevation of the plasma GH concentration to 7.0, 18.4 and 29.6 ng/ml, which were 212, 175 and 191% of the preinjection levels, respectively. There is a positive correlation between the basal and peak plasma GH levels after LHRH. These increases, however, were related to neither the plasma gonadotropin responses to LHRH nor the plasma GH responses to TRH. The basal levels of plasma LH were reduced in 8 patients and normal responses to LHRH were observed in only one patient. Although plasma FSH was undetectable in 5 patients, the FSH response to LHRH appeared normal in 9 patients. These results indicate that an elevation of the plasma GH level after LHRH is not confined to patients with a GH secreting pituitary tumor but observed in subjects with anorexia nervosa and further suggest that the GH responsiveness to non-specific hypothalamic releasing hormones may be due to the impaired hypothalamic control in anorexia nervosa.

Adolescent↗
PubMed1987

Systemic mastocytosis without cutaneous involvement.

An autopsy case of systemic mastocytosis without cutaneous involvement in a 76-year-old woman was described. The patient presented with general malaise, chest and epigastric discomfort, flushing of the face and progressive hepatosplenomegaly, and she terminated in hemorrhagic complications of DIC within 2 months. There was neither rash nor urticaria pigmentosa recognizable in the entire course. The diagnosis was made by the histologic identification of abnormal aggregates of mast cells in a bone marrow aspirate. These mast cell granules were chloroacetate esterase-positive, peroxidase-negative, and electronmicroscopically they were composed of fine granular materials containing variable numbers of lamellar structures. At autopsy, diffuse infiltration of the mast cells was found in the liver, spleen, bone marrow, lymph nodes, lungs, kidneys, stomach, and adrenal glands.

Aged↗
PubMed1987

Intracerebroventricular injection of cholecystokinin octapeptide elevates plasma prolactin levels through stimulation of vasoactive intestinal polypeptide.

We investigated the effect of cholecystokinin octapeptide (CCK-8) on plasma PRL levels in freely moving male rats. Intravenous injection of CCK-8 did not affect basal plasma PRL levels in doses up to 5000 ng/rat; however, plasma PRL increased significantly after intracerebroventricular (icv) injection of the peptide at a dose of 40 ng/rat. Proglumide (0.2 mg/kg, iv) and benzotript (0.2 mg/kg, iv), specific CCK receptor antagonists, blocked the icv CCK-8-induced increase in plasma PRL levels. There was no apparent effect of icv CCK-8 on the enhancement of PRL release by haloperidol (0.2 mg/kg, iv), sulpiride (0.1 mg/kg, iv), domperidone (0.1 mg/kg, iv), or RO22-1319 (0.1 mg/kg, iv). However, the apomorphine-induced inhibition of PRL secretion was significantly antagonized by icv CCK-8. Furthermore, icv CCK-8 increased plasma PRL levels in rats depleted of dopamine by pretreatment with reserpine and alpha-methyl-p-tyrosine. Finally, the elevation in plasma PRL levels produced by icv CCK-8 was substantially antagonized by vasoactive intestinal polypeptide antiserum (1:3; 10 microliter/rat, icv). These results suggest that CCK-8 increases plasma PRL through an interaction with a central CCK receptor, which stimulates the activity of vasoactive intestinal polypeptide, a putative PRL-releasing factor.

Animals↗
PubMed1986

Brain choline acetyltransferase activity and neuropeptide Y concentrations in Alzheimer's disease.

Choline acetyltransferase (ChAT) activity and neuropeptide Y (NPY) levels in post-mortem tissues from patients with histologically proven Alzheimer's disease were compared with age-matched neurologically normal control individuals. Despite the high NPY concentrations in human cerebral cortex, no significant abnormalities were found. However, ChAT activity was reduced throughout the cortex, without a relationship to areas of functional deficit, as previously identified using fluorodeoxyglucose. These results lend further support to the concept of Alzheimer's disease as a highly selective neurodegenerative disorder.

Alzheimer Disease↗
PubMed1986

Early radiographic changes in radiation bone injury.

A chronologic series of periapical radiographs was evaluated for the purpose of detecting damage to bone and tooth-supporting tissues in a patient receiving radiation therapy for a basal cell carcinoma of the mandibular gingiva. Widening of the periodontal space was one of the early radiographic changes observed. It is suggested, from the sequence of radiographic changes, that radiation-induced changed in the circulatory system of the bone might be primarily responsible for the resulting changes.

Alveolar Process↗
PubMed1986

Improved purification of Aspergillus oryzae 1,2-alpha-mannosidase by using mannan gel affinity chromatography.

In order to facilitate the purification of 1,2-alpha-mannosidase from an enzyme product of Aspergillus oryzae, we have devised a rapid and simple procedure. A partially purified enzyme preparation obtained from the A. oryzae enzyme product, by means of ammonium sulfate fractionation followed by CM-Sephadex C-50 chromatography, was subjected to affinity chromatography with baker's yeast mannan gel as an adsorbent. 1,2-alpha-Mannosidase was retarded and well separated from the major protein peak on the affinity column. After a second affinity chromatography under the same conditions, 1,2-alpha-mannosidase was finally purified 7,500-fold with a 22.9% yield. The enzyme preparation thus obtained was quite suitable for the structural analysis of glycoconjugates.

Aspergillus↗
PubMed1986

Chronic lithium treatment decreases [3H]-imipramine binding in rat brain.

The effect of a chronic lithium treatment on the [3H]-imipramine binding in rat brain regions was investigated. In the striatum, an oral administration of lithium for 30 days induced a decrease in the [3H]-imipramine binding at the concentration of [3H]-imipramine, 1.0 nM, compared to the control. Lithium did not affect the [3H]-imipramine binding in the cerebral cortex and hypothalamus. A Scatchard analysis in the striatum revealed a decrease in the number of [3H]-imipramine binding sites with no changes in the binding affinity. These results suggest that the chronic lithium treatment may produce subsensitivity of the [3H]-imipramine binding in man and that this effect of the ion may be closely related to the established effect of lithium in the treatment of affective disorders.

Animals↗
PubMed1985

Clinical, demographic, and genetic aspects of the Werner syndrome in Japan.

A total of 196 typical patients with the Werner syndrome, a caricature of aging, was studied to define the details of the clinical manifestations, demography and genetic aspects in Japan. Most of the previously reported clinical characteristics and the autosomal recessive inheritance of this syndrome were confirmed, but no significant linkage was revealed between specific HLA type and the Werner syndrome. The frequency of the Werner syndrome in Japan was estimated using two methods which indicated approximately 300 cases among 100 million people.

Adult↗