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Biomedical subjects

K Kosaka

Publications and source records attributed to K Kosaka.

At least 271 records · Page 15Linked to original sources
PubMed1987

Differential effect of functional olfactory deprivation on the GABAergic and catecholaminergic traits in the rat main olfactory bulb.

The effects of the unilateral olfactory naris closure were studied immunohistochemically in the main olfactory bulb of adult rats. In the olfactory deprived bulbs, the tyrosine hydroxylase-immunoreactive elements in the glomeruli and the juxtaglomerular region decreased drastically, whereas the glutamate decarboxylase-immunoreactive elements in these regions showed no appreciable changes, indicating the differential effects of olfactory deprivation on catecholaminergic and GABAergic traits in spite of their coexistence in some neurons in these regions.

Animals↗
PubMed1987

An aspect of the organization of the GABAergic system in the rat main olfactory bulb: laminar distribution of immunohistochemically defined subpopulations of GABAergic neurons.

The organization of the GABAergic system in the rat main olfactory bulb was investigated immunohistochemically using antisera against glutamic acid decarboxylase (GAD), tyrosine hydroxylase (TH), parvalbumin (PV) and methionin-enkephalin-Arg6-Gly7-Leu8 (ENK). Some GABAergic neurons were shown to contain TH immunoreactivity in the glomerular layer, PV immunoreactivity in the external plexiform layer and ENK-like immunoreactivity in the granule cell layer, indicating the stratified organization of the GABAergic subsystems.

Animals↗
PubMed1987

Postnatal development of neurons containing both catecholaminergic and GABAergic traits in the rat main olfactory bulb.

Postnatal development of catecholaminergic and gamma-aminobutyric acid (GABA)-ergic neurons in the periglomerular region of the rat main olfactory bulb was studied immunohistochemically using antisera against tyrosine hydroxylase (TH), glutamic acid decarboxylase and GABA. TH-like immunoreactive neurons almost always contained GABA-like immunoreactivity in the first postnatal week, but about 10% of them did not contain GABA-like immunoreactivity in older animals.

Aging↗
PubMed1987

Catecholaminergic neurons containing GABA-like and/or glutamic acid decarboxylase-like immunoreactivities in various brain regions of the rat.

The coexistence of immunoreactivities for tyrosine hydroxylase (TH) and glutamic acid decarboxylase (GAD) and/or gamma-aminobutyric acid (GABA) was revealed in various brain regions in colchicine-injected and untreated rats, using the peroxidase-antiperoxidase method. Consecutive 40 micron thick Vibratome sections were incubated in different antisera and those cells which were bisected by the plane of sectioning so as to be included at the paired surfaces of two adjacent sections were identified. The coexistence of the immunoreactivities for TH and GAD or GABA in the same cell could thus be determined by observing the immunoreactivity of the two halves of the cell incubated in two different antisera. In the olfactory bulb, retina, diencephalon, mesencephalic central grey and cerebral cortex, many TH-like immunoreactive neurons also showed GAD-like or GABA-like immunoreactivity, whereas in the substantia nigra, ventral tegmental area and locus ceruleus none of TH-like immunoreactive neurons showed either GAD-like or GABA-like immunoreactivity. In the olfactory bulb, retina and cerebral cortex, the majority of the TH-like immunoreactive neurons were also GAD-like or GABA-like immunoreactive. In the diencephalon of colchicine-injected rats, at least one-third of the TH-like immunoreactive neurons were GAD-like immunoreactive. Using serial 0.5 micron thick plastic-embedded sections, it was shown that immunoreactivities for three antigens, GAD, GABA and TH could occur in the same neurons in the olfactory bulb. These observations indicate the possible coexistence of two classical transmitters. GABA and catecholamine, in various brain regions of the rat.

Animals↗
PubMed1987

Intraneuronal polyglucosan bodies and peculiar inclusions in the midbrain-tegmentum of the aged.

A small number of intraneuronal polyglucosan bodies, the so-called Lafora bodies, is occasionally found in the tegmental areas of the midbrain in aged cases with no metabolic or degenerative diseases. The occasional appearance of peculiar bodies, which Kato et al. (1982) reported in a case of presenile dementia, is also observed during the examination of the inclusions. The ultrastructure of the bodies reveals an amorphous, electron-dense central core and a peripheral zone of radially oriented 100 A wide filaments.

Aged↗
PubMed1987

Time course of islet cell antibodies and beta-cell function in non-insulin-dependent stage of type I diabetes.

The time course of islet cell antibodies (ICA) and serum C-peptides responses (CPRs) to oral glucose tolerance tests (OGTTs) were studied prospectively up to 60 (mean 35) mo in 32 ICA-positive subjects [28 with non-insulin-dependent diabetes (NIDDM) and 4 subjects with impaired glucose tolerance (IGT); mean age 45 yr], 96 matched subjects [56 with NIDDM, 8 with IGT, and 32 normal first-degree relatives of patients with insulin-dependent diabetes (IDDM); mean age 45 yr] who were negative for ICA at the beginning of the study. In addition, the effects of human leukocyte antigens (HLA) on the time course of ICA and beta-cell function were evaluated. In 10 subjects (8 with NIDDM and 2 with IGT) who were ICA positive, ICA became undetectable, even by sensitive ICA assay, 15 +/- 2 mo (mean +/- SE) after initiation of this study. In these subjects, integrated serum CPR values (sigma CPR) and 2-h blood glucose values in response to OGTTs improved significantly (P less than .05-.01). In contrast, the remaining 22 subjects who were ICA positive were persistently positive for ICA. CPR and blood glucose responses deteriorated progressively in these 22 subjects, and 7 subjects in this group progressed to the insulin-dependent state. Serum CPR and blood glucose responses to OGTTs showed no remarkable changes in 64 patients (56 with NIDDM and 8 with IGT) and 32 normal first-degree relatives of patients with IDDM who remained negative for ICA throughout the study.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1986

Extrahypophyseal distribution of alpha-melanocyte stimulating hormone (alpha-MSH)-like immunoreactivity in postmortem brains from normal subjects and Alzheimer-type dementia patients.

Using a sensitive double-antibody solid-phase enzyme immunoassay method alpha-melanocyte stimulating hormone-like immunoreactivity (alpha-MSH-LI) was measured in 21 regions of postmortem brains from 8 normal subjects and 5 patients with Alzheimer-type dementia (ATD). In the brains from the normal subjects, the highest concentration of alpha-MSH-LI was found in the hypothalamus. Relatively high concentration were also measured in the locus coeruleus, substantia innominata, substantia nigra, amygdala and medial nucleus of thalamus. alpha-MSH-LI in other regions was approximately 1/100 of the hypothalamic content. This data is consistent with the existence of alpha-MSH in extrahypophyseal regions and indicates its regional distribution in the human brain. In the Alzheimer brains, although the temporal cortex and hippocampus had normal concentrations of alpha-MSH-LI, the cingulate cortex, caudate and substantia nigra showed significantly lower concentrations of alpha-MSH-LI than those of the control brains. This data suggests that further studies of alpha-MSH content in a larger number of ATD brains would be useful.

Aged↗
PubMed1986

Regional distribution of amino acid transmitters in postmortem brains of presenile and senile dementia of Alzheimer type.

We measured the concentrations of glutamate, aspartate, and gamma-aminobutyrate (GABA) in cortical and subcortical areas by an enzymatic fluorometric method in 9 patients with histologically verified Alzheimer's disease and senile dementia of the Alzheimer type (AD/SDAT), and in 10 age-matched normal control subjects. When compared with controls, the concentration of glutamate in cortical and subcortical areas of AD/SDAT brains was significantly reduced. The concentrations of aspartate and GABA were also reduced in several areas, but the magnitude of reduction was less than that of glutamate. This apparent reduction of glutamate in postmortem brains might have a bearing on pathophysiological mechanisms in AD/SDAT.

Aged↗
PubMed1986

A computed tomography study of Alzheimer's disease by regional volumetric and parenchymal density measurements.

Seventeen patients with clinically diagnosed Alzheimer's disease and 13 healthy age-matched controls were studied by means of computed tomography (CT). To assess cerebral atrophy, regional volumetric measurements and parenchymal density measurements were performed. The results indicate that: (1) Alzheimer patients show diffuse cerebral atrophy in the early stage; (2) the evaluation of lobar atrophy by means of CT is useful for the clinical diagnosis of Alzheimer's disease; (3) the evaluation of parenchymal density by means of CT is not as sensitive as the evaluation of lobar atrophy.

Aged↗
PubMed1986

Morphological and biochemical changes in the cholinergic and monoaminergic systems in Alzheimer-type dementia.

The integrity of cholinergic and monoaminergic neuronal systems in Alzheimer-type dementia (ATD) was studied using a combination of morphological and biochemical procedures applied to samples from seven ATD brains and ten control brains. On morphological examination, the number of neurons was counted in the nucleus basalis of Meynert (nbM), the locus coeruleus (LC) and the nucleus centralis superior (NCS). Biochemically, the activities of choline acetyltransferase (ChAT) and the concentrations of noradrenaline (NA) and serotonin (5-hydroxytryptamine; 5-HT) were measured in the nbM, LC, NCS, frontal cortex, temporal cortex and occipital cortex. Compared with the controls, the mean number of neurons in the nbM and LC were significantly reduced in the ATD brains. The neuronal loss in the NCS in the ATD brains was not significant. The ChAT activities in all regions from the ATD brains had a tendency to be reduced. Marked reductions in the NA concentrations in the LC and 5-HT concentrations in the temporal and occipital cortices were found in the ATD brains. These findings suggest that various neurotransmitter systems, including cholinergic, noradrenergic and serotonergic systems, are affected in the ATD brains.

Aged↗
PubMed1986

Cadmium-binding proteins of three marine molluscs and characterization of two cadmium-binding glycoproteins from the hepatopancreas of a whelk, Buccinum tenuissimum.

The cadmium-binding proteins were shown to exist in the hepatopancreas of three molluscs, a whelk, Buccinum tenuissimum, a turbo, Batillus cornutus, and a squid, Todarodes pacificus. Cadmium was efficiently accumulated in nature to a mean concentration of 119, 33, and 50 micrograms/g wet tissue in the hepatopancreas of three species of molluscs, and 30%, 11%, and 43% of the element in each tissue of whelk, turbo, and squid was extracted to the soluble fraction, respectively. Separation of the soluble fraction by Sephadex G-75 in the presence of 2-mercaptoethanol revealed that cadmium was mainly bound to the protein fraction FII of molecular weight 10,000. Two cytoplasmic cadmium-binding glycoproteins from the hepatopancreas of Buccinum tenuissimum were purified to homogeneity by Sephadex G-75 gel filtration and double DEAE-Sephadex A-25 chromatographies in the presence of 2-mercaptoethanol. These two cadmium-binding glycoproteins, termed FIIA and FIIB, had molecular weights of 8000 and 13,000 and consisted of 52 and 94 amino acid residues, respectively. Three and two cysteine residues in FIIA and FIIB, respectively, were found and two more half-cystine were also detected in FIIB. The sugar contents of FIIA and FIIB were about 20.5% and 8.7% by weight, respectively, consisting of galactose, mannose, fucose, and amino sugar. Both showed strong metal-binding ability, especially for cadmium, copper, and mercury.

Animals↗
PubMed1986

Effect of proprioceptive neuromuscular facilitation on EEG activation induced by facilitating position in patients with spinocerebellar degeneration.

The shift of mean power in alpha band of EEG due to postural changes was examined in five patients with spinocerebellar degeneration, using EEG topography, before and after proprioceptive neuromuscular facilitation (PNF) maneuver. Normal EEG response to postural changes, i.e., an increase in the mean power at facilitating position compared to neutral position, was observed in only one patient before PNF maneuver, but in four after PNF maneuver. The improvement of motor function by PNF-treatment was clinically noticed in the patients with normal EEG response to postural changes after PNF maneuver.

Electroencephalography↗
PubMed1986

The prevalence of islet cell antibodies in Japanese insulin-dependent and non-insulin-dependent diabetic patients studied by indirect immunofluorescence and by a new method.

Islet cell antibodies (ICA) were measured in Japanese patients with insulin-dependent diabetes mellitus (IDDM) and non-insulin-dependent diabetes mellitus (NIDDM) by a standard, indirect immunofluorescence method (IF method) and by a newly established, three-layer immunofluorescence method applying a biotin-avidin system (BAS method). In addition, the relationship between ICA and HLA was studied in IDDM patients. ICA titers detected by the BAS method correlated well with those determined by the standard IF method (rS = 0.987, P less than 0.01). The BAS method had about an eightfold higher sensitivity for ICA than the IF method. The overall prevalence of ICA detected by the BAS method (ICA-BAS) versus that by the IF method (ICA-IF) was 41% (82/198) versus 28% (56/198) in IDDM patients and 3% (19/593) versus 2% (14/593) in patients with NIDDM. In IDDM patients, ICA-BAS was all positive less than 1 mo after the onset of diabetes, while the prevalence of ICA-IF was 83% (20/24) during the same period. The prevalence of ICA-IF decreased rapidly with the duration of disease, reaching a value of 6% (3/55) in the patients with a disease duration of 10 yr or more. The incidence of ICA-BAS also decreased with the duration of disease, although to a lesser degree than ICA-IF. No association was found between HLA types and persistence of ICA-BAS or -IF.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗