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H Uchimura

Publications and source records attributed to H Uchimura.

At least 73 records · Page 4Linked to original sources
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↗
PubMed1987

n-Butyrate increases the level of thyroid hormone nuclear receptor in non-pituitary cultured cells.

The thyroid hormone nuclear receptor is a chromatin-associated protein regulating expression of specific genes. Acetylation of nucleosomal core histones is thought to be one of the factors regulating transcriptional activity of chromatin, and it is suggested that this reaction negatively regulates thyroid hormone receptor levels in GH1 cells (Samuels, H.H., Stanley, F., Casanova, J., and Shao, T. C. J. Biol. Chem. 255, 2499-2508). In the present study, we found that n-butyrate, a potent inhibitor of histone deacetylase, increases thyroid hormone receptor levels in three distinct non-pituitary cells without changing binding affinity. This effect appeared within 30 min and reached a plateau (240% of control) after a 6-h treatment, before important cellular functions were affected. This effect was time-dependent, dose-dependent, reversible, and paralleled the changes in the electrophoretic mobilities of histones H3 and H4. n-Butyrate prolonged the receptor half-life, and this prolongation corresponded to the increase of receptor levels. Thyroid hormone did not reduce its own receptor levels or influence the effect of n-butyrate. Considering the difference between GH1 cells and non-pituitary cells in the regulation of thyroid hormone receptor levels, our observations, together with those of Samuels et al., suggest the possibility that the acetylation of chromatin-associated proteins has a physiological significance in the regulation of thyroid hormone nuclear receptor levels.

Acetylation↗
PubMed1987

Mass fragmentographic determination of gamma-aminobutyric acid and glutamic acid in discrete amygdaloid nuclei of rat brain.

A mass fragmentographic method for the simultaneous quantification of gamma-aminobutyric acid (GABA) and glutamic acid is described. In a convenient one-step reaction, the two amino acids were derivatized with pentafluoropropionic anhydride and pentafluoropropanol. The derivatization products were stable for several days. The technique has been applied to the assay of GABA and Glu in five amygdaloid nuclei of the rat brain. The GABA level was high in the central and medial nuclei, whereas the Glu level was high in the lateral and basal nuclei. The regional distribution of GABA was different from that of Glu within the amygdaloid nuclei.

Amygdala↗
PubMed1987

Thyroglobulin release-stimulating activity in immunoglobulin G from patients with Graves' disease studied by human thyroid cells in vitro.

The ability of TSH or immunoglobulin G (G-IgG) from untreated patients with hyperthyroidism due to Graves' disease to stimulate thyroglobulin (Tg) release from human thyroid cells was studied. Thyroid tissue obtained from antithyroid drug-treated Graves' hyperthyroid patients was dispersed enzymatically and cultured in monolayers; medium was changed every 3 days. The cultured cells initially released large but declining amounts of Tg, independent of the presence of TSH (approximately 5 micrograms/dish on day 3 and approximately 1.5 micrograms/dish on day 6). After 6 days, TSH had a dose-dependent stimulatory effect on Tg release, and the peak response occurred on day 15. G-IgG-induced Tg release was found on the 12th day of culture and was maximal on day 18. Thyroid cells cultured for 12 days in the absence of TSH responded to TSH and G-IgG in a time- and dose-dependent fashion. Using 12-day cultures, Tg release-stimulating activity (Tg-RSA) was tested using 5 mg/ml (7.5 mg/dish) G-IgGs from 20 patients and 72-h incubation. The Tg-RSA of individual patients varied. However, significant correlations were found between Tg-RSA values and serum Tg concentrations or Tg-RSA and thyroid-stimulating immunoglobulin activities. No correlation was found between Tg-RSA and TSH binding inhibitor immunoglobulin activities. These results suggest that Tg-RSA can be an indicator of abnormal IgG of hyperthyroid Graves' patients. Whether the activity is identical with thyroid-stimulating activity remains to be clarified.

Adolescent↗
PubMed1986

Changes in thyrotropin binding inhibiting immunoglobulins (TBII) in sera of patients with Graves' disease at the time of relapse or exacerbation.

Thyrotropin Binding Inhibiting Immunoglobulins (TBII) were measured in sera of 240 patients with Graves' disease who were followed 0-25 yr as a cross-sectioned study (21 untreated, 189 under therapy and 30 T3-suppressible and drug-discontinued patients) by using solubilized porcine thyroid TSH receptor. Assays were performed by using 50 microliter of serum. All untreated 21 patients showed positive TBII. Frequency of positive patients decreased yearly with treatment although 36% of patients remained positive after 6 yr of therapy. After that time TBII were positive in 61% of follow-up patients and in 16 positive patients who have been treated for more than 10 yr, drug therapy could not be stopped because of recurrence. TBII were positive in 6 of 30 T3-suppressible patients. As a longitudinal study changes in TBII were studied in 10 patients at the time of relapse or exacerbation. TBII increased in parallel with increases in thyroid hormone concentrations in 3 of 10 patients. Six of the others showed earlier or later TBII increases than those in thyroid hormones. One patient did not show any change in TBII, albeit thyroid hormone concentrations were found to be increased. Our observations suggest that abnormal IgGs detected as TBII in sera of patients with Graves' disease by the present method do not explain the occurrence of hyperthyroidism.

Adult↗
PubMed1986

Preparation of tyrosine-O-[35S]sulfated cholecystokinin octapeptide from a nonsulfated precursor peptide.

A rapid and simple one-pot method for O-sulfation of nonsulfated cholecystokinin octapeptide (CCK-8) was developed using sulfuric acid and dicyclohexylcarbodiimide (DCC) without protection of the amino acid side chains. The extent of sulfation was increased with increasing the amount of reactants, sulfuric acid, and DCC, and reached maximum (40%) with fourfold molar excess of sulfuric acid and 40-fold molar excess of DCC. The excess of nonsulfated peptide inhibited the sulfation. The sulfation product was purified by HPLC or TLC to give a pure sulfated substance which showed exactly the same behavior as that of an authentic O-sulfated CCK-8 on HPLC or TLC. The purified sulfated peptide was active in stimulating amylase secretion from rat pancreatic fragments, and amino acid analysis showed that the tyrosine residue in the peptide existed in O-sulfated form. Sulfation with [35S]sulfuric acid-DCC produced a radioactive substance, from which O-[35S]sulfated CCK-8 could be easily purified by two-dimensional TLC.

Cholecystokinin↗
PubMed1986

A bioassay for thyroid stimulating immunoglobulins of patients with Graves' disease using porcine thyroid monolayer cells.

A bioassay for thyroid stimulating immunoglobulins (TSI) of patients with Graves' disease was developed by porcine thyroid monolayer cells. Thyroid cells were prepared by dispersion using collagenase and trypsin. Aliquots of the cell suspension (2 X 10(6) cells/1.5 ml/dish) in Ham's F-12 medium (pH 7.2) containing 10% calf serum and 1.5 mM Hepes were seeded and cultured in air at 36 C. On day 6 of culture, cells were incubated with test samples (IgG or bTSH) in 1 ml of serum-free, 0.5 mM IMX-included fresh medium for an additional time, and cAMP in the cells was measured by radioimmunoassay. Intracellular cAMP was increased within 5 minutes after the addition of bTSH and the maximal increase was observed after 30 min. Responses of cAMP were in a dose-related manner up to 10 mU/ml of bTSH. With the addition of IgG from untreated Graves' patients, dose-related increases in cAMP were also observed up to 10 mg/ml IgG and the maximal response was seen at 2 hours incubation. Thyroid stimulating activity in IgG's from normal subjects and patients with Graves' disease was tested with a dose of 10 mg/ml and 2 hours incubation and the activity was expressed as a percent of the control (incubated in the same experiment without IgG). One hundred forty one of 145 untreated patients showed higher activity (228 +/- 51.8%, mean +/- SD; 127-393%, range) than normal subjects (103 +/- 13.3%, mean +/- SD, n = 24; 80-129%, range). Sequential changes in TSI activity in 27 patients after initiating thionamide drugs were studied for 24 months. Initially all 27 patients showed positive TSI and 6 months later 15 remained positive. At 6 months after that, 10 of 23, 4 of 16, and 2 of 6 followed patients showed positive TSI. These results indicate that this bioassay is clinically useful for detecting TSI.

Animals↗