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H Uchimura

Publications and source records attributed to H Uchimura.

At least 73 records · Page 4Linked to original sources
PubMed1991

Age-related vulnerability to cerebral ischemia in spontaneously hypertensive rats.

BACKGROUND AND PURPOSE: We sought to determine the effects of aging on regional cerebral blood flow and ischemic brain damage in transient cerebral ischemia in rats. METHODS: Five adult (5-6 months) and five aged (18-22 months) female spontaneously hypertensive rats were subjected to 20 minutes of bilateral carotid occlusion and 60 minutes of recirculation under amobarbital anesthesia (100 mg/kg i.p.). Regional cerebral blood flow in the hippocampus and striatum was measured using the hydrogen clearance method. Nine adult and 14 aged rats were subjected to 20 minutes of bilateral carotid occlusion or were sham-operated under ether anesthesia. Seven days after 20 minutes of cerebral ischemia, the rats' brains were perfusion fixed. Ischemic damage in the hippocampus and striatum was graded (0 [normal] to 3 [majority of neurons damaged]). RESULTS: After 20 minutes of bilateral carotid occlusion, striatal cerebral blood flow decreased to 9.1 +/- 1.5 and 3.9 +/- 2.0 ml/100 g/min in aged and adult rats, respectively, and hippocampal cerebral blood flow decreased to 8.6 +/- 2.4 and 5.7 +/- 2.4 in aged and adult rats, respectively. Although these ischemic cerebral blood flow values were not significantly different between the two age groups, scores for ischemic damage in the hippocampus CA-1 subfield and striatum were significantly higher in aged than in adult rats (p less than 0.05, Kruskal-Wallis' h test with Bonferroni correction). CONCLUSIONS: We conclude that aging may be a primary factor in the development of greater ischemic neuronal damage observed in aged hypertensive rats.

Aging↗
PubMed1991

Growth stimulating activity secreted by human anaplastic thyroid carcinoma cells.

In order to clarify the mechanism of rapid growth of anaplastic thyroid carcinoma, growth stimulating activity produced by the cancer cells in culture was studied. A cell line (HTh7) established from a biopsy specimen of anaplastic thyroid carcinoma was used throughout the study. Growth stimulating activity was determined as an activity to increase 3H-thymidine incorporation in rat thyroid cell line (FRTL5). Conditioned medium of HTh7 cells contained significant growth stimulating activity for FRTL5 cells. The activity was separated into two fractions with heparin agarose gel: heparin-binding and heparin-non-binding. In the medium, the heparin-non-binding activity was much greater than the heparin-binding one. The heparin-non-binding activity was acid stable. It was partially purified with gel filtration in an acidic condition followed by reverse phase HPLC. In gel filtration with a Sephacryl S-200 column, the activity was eluted later than the elution volume of cytochrome c (MW 12400) as several separated peaks. In reverse phase HPLC, however, the activity in these peaks was eluted as a single peak. The retention time of the active peak was almost the same as that of recombinant IGF-I. When measured by specific RIAs, the conditioned media concentrated 20 times contained both 0.35 ng/ml of IGF-I and 5.21 ng/ml of IGF-II. As for the heparin-binding mitogenic activity, when applied to heparin affinity HPLC column and eluted with a linear gradient of NaCl, the activity came out as one major peak with approximately 1.0 M NaCl.(ABSTRACT TRUNCATED AT 250 WORDS)

Carcinoma↗
PubMed1991

[Measurement of anti-microsomal and anti-thyroglobulin antibodies by radioimmunoassay].

In this study, we measured anti-microsomal (same as anti-thyroid peroxidase) and anti-thyroglobulin antibodies (anti-TPOAb and anti-TgAb) in sera by new RIA kits and compared with the conventional particle agglutination (PA) kits. Two of 80 normals (2.5%) showed anti-TPOAb positive activity (greater than or equal to 0.3 unit/ml), and 9 of same samples (11.3%) showed anti TgAb positive activity (greater than or equal to 0.3 unit/ml). Sixty of 67 patients with Graves' disease (89.6%), and 14 of 22 with Hashimoto's disease (63.6%) were anti-TPOAb positive, and 42 (62.7%), and 18 (81.8%) were anti-TgAb positive respectively. Samples of 5 non-autoimmune disease were all negative by TPOAb and TgAb assays, suggesting the high specificity of new RIA kits to the autoimmune thyroid diseases. The RIA and PA methods showed a good correlation (anti-TPOAb:rs = 0.9134, anti-TgAb:rs = 0.7016). However, several negative sera in PA assay showed positive values in the RIA, so it was showed that new RIA kits were more sensitive than the PA assays.

Autoantibodies↗
PubMed1990

Behavioral sensitization to beta-phenylethylamine (PEA): enduring modifications of specific dopaminergic neuron systems in the rat.

Repeated daily administration of an endogenous trace amine, beta-phenylethylamine (PEA), produces behavioral sensitization such that the intensity of PEA-induced stereotyped behaviors in rats increases gradually during the treatment, and a challenge injection with PEA reinstates the enhanced stereotypy even long after withdrawal. In the present study, we examined the neurochemical changes in the central dopaminergic neurons systems in the rat for 7 drug-free days after repeated treatment with PEA (50 mg/kg, IP day for 14 or 28 days). During withdrawal, a decrease in steady-state levels of tissue dopamine (DA) and its metabolite, dihydroxyphenylacetic acid (DOPAC), was found in the mesolimbic DA nerve terminal areas of the rat brain receiving repeated PEA treatment. Fifteen minutes after challenge administration of PEA at varying doses from 6.3 to 75 mg/kg, the rats with repeated PEA treatment required smaller doses of PEA challenge than the rats with acute PEA treatment in order to obtain a significant decrease in striatal DOPAC content compared to the saline control in each treatment group. These results imply that the behavioral sensitization to PEA is accompanied by enduring modifications of the specific dopaminergic neuron systems in the rat brain. This suggestion was strongly supported by the results of the study using in vivo intracerebral dialysis, which indicated that 25 mg/kg PEA challenge elicited a remarkable increase in the extracellular DA concentrations in striatal perfusates collected from the PEA-pretreated rats, in accordance with the intensity of stereotyped behaviors. These findings argue that the hyper-responsiveness to PEA of the striatal dopaminergic neuron systems persists long after withdrawal from repeated treatment with PEA.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1990

Changes in GABA content and turnover in discrete regions of rat brain after systemic administration of caerulein.

The effects of systemically injected caerulein, a cholecystokinin octapeptide analogue, on GABA content and turnover have been studied in various regions of rat brain. Caerulein decreased GABA levels in the nucleus accumbens, tuberculum olfactorium and substantia nigra and diminished GABA turnover rates in the striatum, nucleus accumbens and substantia nigra, as estimated from the rate of GABA accumulation after inhibition of GABA transaminase by aminooxyacetic acid (AOAA). These results indicate the effect of caerulein on the utilization of GABA in specific cerebral regions and suggest that the GABAergic system is involved in the mechanism of action of peripherally administered caerulein.

Animals↗
PubMed1990

Changes in thyroglobulin release-stimulating activity (Tg-RSA) in immunoglobulin G from patients with Graves' disease during therapy with thionamide drug.

We have reported previously a new method for detecting thyroglobulin release stimulating activity (Tg-RSA) by human thyroid monolayer cells in IgGs from Graves' patients. We report here changes in Tg-RSA in sera of patients during treatment with thionamide drug. Nineteen untreated patients had their Tg-RSA, TSAb, TBII and serum Tg concentration (STg) followed up. Before treatment, Tg-RSA and TSAb were positive in all 19 patients. Three of them were TBII negative. During treatment with thionamide, of 16 patients who had positive Tg-RSA, TSAb and TBII before treatment, 6 patients continued so during the period of observation. Of the remaining 10 patients, 8 became TBII negative. TSAb only was found negative in one patient and Tg-RSA only declined to negative in another patient. Three patients whose TBII was initially negative, were observed to be negative in all three indicators after treatment. STg was higher than normal in all patients before therapy and changes in Tg-RSA in almost all patients were parallel with those in STg during treatment. From the observation during treatment with thionamide, our results suggest that Tg-RSA in Graves' patients appears to have similar properties to TSAb.

Amides↗
PubMed1990

Striatal glutamic acid and gamma-aminobutyric acid in transient cerebral ischemia in spontaneously hypertensive rats.

A massive striatal dopamine release (241-fold increase) was observed in a previous study during acute cerebral ischemia in rats. In this study, extracellular levels of glutamic acid (GLU), gamma-aminobutyric acid (GABA) and lactic acid were simultaneously determined using in vivo brain dialysis in the striatum of spontaneously hypertensive rats during cerebral ischemia and after recirculation. Extracellular GABA levels increased to 932 +/- 75% (mean +/- SEM) of the resting level and GLU increased to 390 +/- 63% during 20 min ischemia. Although ischemia-induced release of GLU and GABA was demonstrated in this study, the degree of increase was smaller than that of dopamine. These findings may be relevant to the pathophysiology of cerebral ischemia in the striatum.

Animals↗
PubMed1989

Involvement of brain stem noradrenergic neurons in the development of hypertension in spontaneously hypertensive rats.

This study attempted to investigate the possible involvement of the brain stem noradrenergic system in the development of hypertension in spontaneously hypertensive rats. Steady-state norepinephrine, dopamine, serotonin and 5-hydroxyindoleacetic acid concentrations and norepinephrine turnover were determined in the individual brain stem nuclei using high performance liquid chromatography with electrochemical detection. Decreased norepinephrine contents in the nucleus tractus solitarii in spontaneously hypertensive rats compared with Wistar-Kyoto rats at the age of 4, 8, and 16 weeks were demonstrated. In later stages (8 and 16 weeks), increased norepinephrine levels were observed in the nucleus reticularis gigantocellularis, the A1 and A5 areas. Norepinephrine turnover was not different between spontaneously hypertensive rats and Wistar-Kyoto rats in the nucleus tractus solitarii at the age of 4 and 16 weeks and increased in the nucleus reticularis gigantocellularis of spontaneously hypertensive rats at 16 weeks. Our results indicate that altered norepinephrine metabolism in the specific brain stem nuclei, especially the consistently decreased norepinephrine in the nucleus tractus solitarii of spontaneously hypertensive rats, contribute to the development of genetic hypertension.

Adrenergic Fibers↗
PubMed1989

[A family of pseudocholinesterase deficiency (silent type II)].

We report here a case of pseudocholinesterase (E.C. 3.1.1.8) deficiency, silent type II. The proband was a 29-year-old healthy man. His parents were cousins. A family study revealed that 9 out of 17 members of family investigated (paternal side 6, maternal side 3) concentrations. Serum cholinesterase activity were correlated well with serum albumin concentrations in both healthy people and patients with chronic liver diseases. The ratio of cholinesterase activity to albumin concentrations in serum was found more useful to detect heterozygous pseudocholinesterase deficiency than the serum cholinesterase activity alone. Both the dibucaine number and the fluoride number were within normal range in all family who showed low cholinesterase activity in serum. The amount of immunoreactive substance in serum against anticholinesterase antibody was normal in the proband as well as his family, while it was about twice of the value expected from their activity in those who had low ratio of serum cholinesterase activity to albumin concentrations. These results altogether suggested that the proband was a case of homozygous pseudocholinesterase deficiency, silent type II.

Adult↗
PubMed1989

[beta-Phenylethylamine and amphetamine: similar aspects in their behavioropharmacological and neurochemical characteristics].

The authors found there was behavioral sensitization induced by repeated intermittent treatments with beta-phenylethylamine (PEA), an endogenous trace amine, similar to the so-called reverse-tolerance phenomenon which persists long after the withdrawal. A series of behavioropharmacological and neurochemical studies on the PEA-sensitized rats were compared with that on the sensitization induced by amphetamines (AMP). The major portion of this review focused on an involvement of dopaminergic modifications in the reverse tolerance caused by both PEA and AMP. The enhanced stereotype in the PEA-sensitized rats was found to be accompanied by augmentation of presynaptic dopaminergic activity in nigrostriatal and mesocorticolimbic systems by means of regional dissected and in vivo dialysis methods. In particular, a simultaneous measurement of endogenous PEA levels in striatum led us to speculate that the DA terminals in sensitized animals are hyperresponsive to PEA, resulting in enhanced DA release. D2 receptor bindings in nucleus accumbens, not in striatum, also altered in PEA-sensitized rats. In addition, recent literature concerning changes in PEA levels in body fluids in psychiatric disorders are summarized. Lastly, the attractive reports regarding the possibility that central actions of AMP would be mediated by endogenous PEA and that PEA is co-localized with DA in the same neurons were reviewed, suggesting an important role of endogenous PEA in generating the psychostimulant-induced and endogenous psychosis.

Amphetamine↗
PubMed1989

[Roentgenologic evaluation of indrawn parietal pleura].

Among linear densities extending out from the lateral margin of a peripheral mass to the pleural surface, a thin line with a small triangular density at the pleural surface is considered to be contiguous layers of indrawn visceral pleura with a small amount of fluid between layers. We agree that the thin line represents contiguous layers of indrawn visceral pleura, but we believe that the triangular density at the pleural surface is not formed by a small amount of pleural effusion, but by indrawn parietal pleura accompanying extrapleural soft tissue of the chest wall. A trapezoid or a belt shaped soft tissue density between a peripheral mass contiguous to the visceral pleura and the chest wall are also signs of indrawn both visceral and parietal pleurae in the presence of adhesion of the pleura over the mass.

Aged↗
PubMed1988

Facilitatory effects of caerulein on hypothalamic defensive attack in cats.

Effects of intraventricularly microinjected caerulein (0.1, 1.0 and 10.0 micrograms) on the thresholds for hypothalamically elicited defensive attack and influences of haloperidol (0.5 mg/kg, i.p.) on the effects were studied in chronic cats. Directed attack and hissing were selected for threshold determination, and thresholds for these responses were measured under two situations: one with provocations by a human, and the other without such provocation. Results were as follows. (1) Caerulein lowered all thresholds in generally equal decrements and in a dose-related manner, accompanied by a general behavioral arousal. (2) Prior injection of haloperidol prevented the effects of caerulein, suggesting an antagonism-like interaction between haloperidol and caerulein. (3) Observed facilitatory effects of caerulein on the hypothalamic defensive attack were very similar to those observed with dopamine (DA) agonists such as methamphetamine and apomorphine and opposite to those with DA antagonists such as haloperidol and chlorpromazine. These findings suggest that caerulein exerts its facilitatory effects on the excitability of the ventromedial hypothalamic nucleus through its synergistic interaction with DA.

Aggression↗
PubMed1988

Massive striatal dopamine release in acute cerebral ischemia in rats.

Extracellular dopamine, 3,4-dihydroxyphenylacetic acid (DOPAC) and cerebral blood flow were simultaneously determined using in vivo brain dialysis and a hydrogen clearance method in the striatum of spontaneously hypertensive rats during ischemia and after recirculation. Massive striatal dopamine release was demonstrated in acutely induced ischemic brain.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1988

Prevention of horizontal transmission of hepatitis B: efficacy of hepatitis B immunoglobulin and vaccine in an institution for the handicapped.

In a Japanese institution for the handicapped with confirmed continuous outbreaks of hepatitis B virus (HBV) infection by horizontal nosocomial transmission, 29 susceptible subjects (8 institutionalized children and 21 medical staff) were injected intramuscularly with anti-human HBs immunoglobulin (HB Ig) and subcutaneously with HB vaccine. All cases acquired HBs antibody after injection of HB Ig and seropositivity for HB after the third inoculation of HB vaccine was 78.6%. No new case of HB occurred among the study population throughout the period investigated. This suggested the effectiveness of HB Ig and HB vaccine in the prevention of horizontal nosocomial transmission of HBV.

Adolescent↗