Search PubMed⌕ Search

Biomedical subjects

S Kurioka

Publications and source records attributed to S Kurioka.

At least 19 recordsLinked to original sources

Characteristics of health counselling in the workplace via e-mail.

This study was conducted to examine how health counselling via electronic mail (e-mail health counselling) was used in the workplace. The definition of health counselling employed in this study was 'any assistance to an individual seeking to solve any health problem'. A total of 2119 health counsellings conducted at a Japanese company's head office (700 employees) in 1997 and 1998 was used for the analysis, which compared four health counselling methods: e-mail, face-to-face, telephone and ordinary mail. This study distinguished four main characteristics of e-mail health counselling. First, the most and second most frequently used counselling methods were face-to-face and telephone counselling, at 70 and 15%, respectively, with e-mail health counselling ranked third at 13%. e-mail counselling was the second most frequently used method for employees in their 20s and 30s, while it ranked third among those over 40. Only 6% of employees in their 50s used e-mail counselling. Secondly, the proportion of mental health issues treated via e-mail counselling was significantly higher, at 26%, than for other counselling methods, which was at or below 10% for each of the other methods. Thirty-two per cent of all mental health counselling was conducted via e-mail. Thirdly, compared with face-to-face counselling, e-mail counselling dealt with more health issues related to primary prevention than with those related to secondary or tertiary prevention. Fourthly, compared with face-to-face counselling, e-mail counselling dealt more with health issues of third parties. These results suggest that e-mail health counselling may be useful in reaching people other than those targeted by the remaining counselling methods.

Adult↗

Reverse correlation between urine nitric oxide metabolites and insulin resistance in patients with type 2 diabetes mellitus.

We studied the possible relationship between nitric oxide (NO) production and insulin resistance in patients with type 2 diabetes mellitus. Urine NO metabolites (NOx) were measured as an index for NO production by HPLC combined with a Cd column, Griess reaction and a spectrophotometer in 403 healthy control subjects and 102 hospitalized patients with type 2 diabetes. Glucose infusion rate (GIR) was measured as a reverse index for insulin resistance by euglycemic glucose clamp study using an artificial pancreas in 20 of 102 diabetic patients. Urine NOx was lower in the patients with type 2 diabetes than in healthy control subjects (mean+/-SE: 3.18 +/-0.02 versus 3.25 +/-0.01 log[-micromol/gCr], p<0.01). Urine NOx was correlated with body mass index (BMI) in 102 diabetic patients (r= -0.372, p<0.001), but not related to either age, sex, fasting plasma glucose, HbA1c or blood pressure. Urine NOx was correlated with GIR independent of BMI in 20 diabetic patients (r=0.774, P<0.0001). These findings suggest that NO production is closely related with insulin resistance in patients with type 2 diabetes.

Adult↗

Analysis of urinary nitric oxide metabolites in healthy subjects.

Nitric oxide (NO) has divergent actions under physiological and pathological conditions. NO is rapidly decomposed to nitrite (NO2-) and nitrate (NO3-). Since these metabolites are stable, they are good indices of NO production under various conditions. In the present study, we measured NO2- and NO3- concentrations in the urine collected from 62 hospital controls and 504 healthy subjects by means of a new HPLC system combined with Griess reaction. NOx was the sum of NO2- and NO3-. There was no considerable inter-day variation in urinary NO metabolite levels, and there was close correlation between NO2-, NO3- and NOx values in spot urine obtained in the early morning and those in 24-h stored urine in hospital controls. Urinary NO metabolite levels, which were corrected by creatinine (Cr) excretion and expressed on a logarithmic scale, showed normal distribution and were independent of sex and age in healthy subjects. The normal ranges of urinary NO2-, NO3- and NOx levels were estimated as 17-72 micromol/g Cr, 1,023-2,818 pmol/g Cr, and 1,071-2,951 micromol/g Cr, respectively. We also found that urinary NO metabolite levels were lower than normal range in patients with various diseases.

Adolescent↗

Isolation of intramitochondrial helical filaments appearing in outer compartment of mitochondria.

BACKGROUND: Packets of helical filaments have been observed in the outer compartment of occasional mitochondria in many cell types in a variety of animals. The composition and function of these intramitochondrial helical filaments (IMHF) are unknown. METHODS: IMHF were induced in a hepatic mitochondria by administration of ethanol in the drinking water of rats. Hepatic mitochondria were isolated and ruptured by osmotic shock, releasing the IMHF. To purify these structures, the IMHF-containing supernatant was further fractionated by ammonium sulfate precipitation, a 50-60% solution of this reagent being the most effective in this regard. Isolated IMHF were examined by electron microscopy and were analyzed by SDS-PAGE. RESULTS: Isolated IMHF closely resembled their in situ counterparts: they had a right-handed helical structure with a 16 nm pitch. SDS-PAGE analysis revealed that they contained three polypeptides with molecular weight of 135, 98, and 53 kD, respectively. CONCLUSIONS: These observations will stand as a baseline for comparisons with IMHF that occur naturally or that are induced in other cell types by other kinds of experimental manipulation.

Animals↗

In vivo modification of GABAA receptor with a high dose of pyridoxal phosphate induces tonic-clonic convulsion in immature mice.

The biologic cofactor, pyridoxal-5'-phosphate (PLP), is responsible for tonic-clonic convulsion in immature mice. The mechanisms underlying such convulsive fits induced by administration of a single high dose of PLP were studied. The administration of PLP resulted in a 13% increase of PLP in the P2 fraction compared to control P2, and the calculated data suggested that membrane bound PLP increased over 31% (approximately 1 microM). The P2 fraction of administered mice was treated with [3H]NaBH4 and analyzed by SDS-polyacrylamide gel electrophoresis. The radioactivity was mainly incorporated into a 52 kDa protein which corresponded to a GABAA receptor subunit. The addition of PLP in vitro competitively inhibited [3H]GABA binding as well as [3H]flunitrazepam binding to synaptic membranes in a concentration-dependent manner, and 50% inhibition was achieved with 1 mM PLP. The results obtained in the present study demonstrate that PLP was rapidly permeable into the brain through the immature blood-brain barrier and then bound directly to GABAA receptor. It is probable that specific amino groups of lysine residues on the GABAA receptor react in vivo with PLP to form Schiff bases, and that the in vivo modification of the receptor produces a degeneration of GABAergic neurotransmission leading to the onset of a convulsive fit.

Animals↗

A soluble neurite outgrowth molecule in bovine brain.

A neurite outgrowth molecule was purified from soluble fraction of bovine brain by reversed-phase column HPLC following concanavalin A (Con A)-affinity chromatography. This molecule was a 74kDa (named sGP74) and clearly reacted with the monoclonal antibody HNK-1. The amino acid sequences of N-terminal portion and peptides derived from trypsin digests of sGP74 were nearly identical to those of rat brain ankyrin-binding protein (ABGP186) that is a member of immunoglobulin superfamily with adhesive function. Our results suggest that sGP74 preserves multiple immunoglobulin-like domains and is released from an extracellular site of ABGP186.

Amino Acid Sequence↗

Analysis of Con A-binding glycoproteins in synaptosomal membranes.

Concanavalin A (Con A)-binding proteins obtained from solubilized synaptosomal membranes of bovine brain were analyzed by two-dimensional electrophoresis (2DE), and were identified by peroxidase conjugated Con A (Con A-peroxidase staining), after transfer from 2DE gel to nitrocellulose paper. The Con A-binding proteins were resolved up to 40 spots, ranging in isoelectric points (pI) from 4.5 to 8.0 and molecular weight (MW) from 10 kDa to 120 kDa. Most of the Con A-binding proteins were streaked across a pH gradient and/or exhibited as multiple spots, indicating broad charge and molecular weight heterogeneity. The presence of protein groups that showed high affinities for Con A were revealed. Most interesting group (named GP51), which consisted of seven spots separated horizontally in charge heterogeneity (pI5.85-7.5) with MW 51 kDa, was characterized by its binding to an immobilized protein A gel. This implies that GP51 is related to immunoglobulins and/or GP51 may be a new member of the immunoglobulin supergene family.

Animals↗

Analysis and separation of synaptosomal membrane proteins.

Synaptosomal membrane proteins solubilized with 8% CHAPS-8 M urea were analyzed with two-dimensional electrophoresis (2DE). The membrane proteins were resolved up to 250 spots on a 2DE map, ranging in isoelectric points (pI) from 3.5 to 10.0 and molecular weights (MW) from 10 kDa to 200 kDa. Comparison of the mapped proteins of synaptosomal membranes with those of myelin and mitochondrial membranes revealed that synaptosomal membrane proteins were characteristic in the area of pI from 4.0 to 7.5 and MW from 20 kDa to 130 kDa, and that at least 30 spots were synaptosomal membrane-specific proteins. Most of these 30 proteins have not been previously described, named, and characterized. Serial numbers (from SY1 to SY30) were assigned to the proteins on the map in order to investigate them systematically. A preliminary attempt to separate synaptosomal membrane proteins was carried out using a reversed-phase HPLC system. Several proteins could either be isolated or enriched. SY10 (pI 4.6; MW 56 kDa) was one of these proteins, and was of particular interest for its unusual behavior on the reversed-phase column, and for its binding to an immobilized protein A-gel.

Animals↗

Inhibitory effect of cephalosporins on gamma-aminobutyric acid receptor binding in rat synaptic membranes.

Cephalosporins inhibited gamma-aminobutyric acid receptor binding in a concentration-dependent manner in vitro. Scatchard analysis revealed that cefazolin decreased the binding capacity but did not change the affinity of the receptor. It is suggested that this inhibition of gamma-aminobutyric acid receptor binding may be involved in the induction of convulsions by cephalosporins.

Animals↗

4-Aminobutyraldehyde as a substance convertible in vivo to GABA.

[2,3-3H]4-Aminobutyraldehyde ([3H]ABAL) was injected subcutaneously into mice, which were sacrificed at various intervals following injection. [3H] gamma-Aminobutyric acid ([3H]GABA) synthesized in vivo from [3H]ABAL was extracted from the brains, separated, and quantitated. The results showed that in the brain, injected [3HABAL was rapidly transformed into [3H]GABA. [3H]ABAL may penetrate the blood--brain barrier into the central nervous system and then be oxidized to [3H]GABA.

Aldehydes↗

4-Aminobutyraldehyde dehydrogenase activity in rat brain.

An enzyme with NAD+-dependent 4-aminobutyraldehyde dehydrogenase activity was purified about 360-fold from rat brain extract. AMP-Sepharose chromatography was effective in separating the enzyme from other NAD+-dependent aldehyde dehydrogenases included in the extract. The KmS for the substrates NAD+ and 4-aminobutyraldehyde were 4.8 x 10(-4) and 8.3 x 10(-5) M, respectively. The pH optimum for the enzyme was about 8.0. The ratio of activities toward 4-aminobutyraldehyde, propionaldehyde, succinate semialdehyde, and benzaldehyde was 1.00:0.17:0.24:0.09:0.03 when the activity toward 4-aminobutyraldehyde was set equal to 1.00. The enzyme activity in subcellular fractions of rat brain was localized in cytosol.

Aldehyde Oxidoreductases↗

Characterization of gamma-aminobutyric acid binding sites on crude synaptic membranes.

[3H]GABA binding to crude synaptic membranes of rat brain was studied in an attempt to identify GABA binding to its synaptic receptor in the presence of Na+. Membrane vesicles prepared from crude synaptic membrane fractions were useful as a tool to differentiate synaptic GABA receptors from GABA uptake sites. The crude synaptic membranes treated with Triton X-100 [membranes (TX)] involved two classes of GABA binding sites (KD = 38.7 and 78.0 nM) in the absence of Na+, but the high-affinity sites disappeared in the presence of Na+ and a single class of GABA binding sites (KD = 75.0 nM) was detected. The failure to detect an active uptake of [3H]GABA into the vesicles prepared from membranes (TX) suggests that the [3H]GABA binding in the presence of Na+ was related to synaptic GABA receptors. It is probable that Na+ could mask the presence of the high-affinity class of GABA receptor.

Animals↗

Effects of sodium and bicarbonate ions on gamma-aminobutyric acid receptor binding in synaptic membranes of rat brain.

Crude synaptic membranes treated with Triton X-100 (TX) bound gamma-aminobutyric acid (GABA) to two classes of receptor site in Na+-free 10 mM-Tris-sulfate buffer (pH 7.4), but to only a single class of receptor site in 10 mM Tris-sulfate buffer (pH 7.4), containing 150 mM-NaCl. The high-affinity receptor site in TX membranes was specifically masked in the presence of Na+. However, TX membranes incubated in Krebs-Ringer bicarbonate solution (pH 7.4) bound GABA to two classes of receptor site despite the presence of Na+. It was found that addition of bicarbonate ions to the Na+-containing 10 mM-Tris-sulfate buffer (pH 7.4) could restore that high-affinity class of GABA receptors, rendering both classes detectable. This finding suggests that both Na+ and HCO-3 may have a regulatory function on GABA binding to the receptor.

Animals↗

Influence of sodium-independent gamma-aminobutyric acid binding on the assay of sodium-dependent gamma-aminobutyric acid binding in a membrane preparation of rat brain.

A large amount of [3H]GABA was bound to crude synaptic membrane fractions of rat, by sodium-independent process in a medium that contained 100 microM [3H]GABA used for assaying GABA uptake site. This [3H]-GABA binding was different from receptor binding of GABA. It was confirmed that this sodium-independent [3H]GABA binding scarcely occurred in the presence of a physiological concentration of sodium chloride, and that sodium-independent GABA binding had a negligible influence on sodium-dependent GABA binding.

Animals↗

Dispersion of fibrin using cationic detergent.

By treating fibrin with cationic detergent in a medium containing 5M urea, a fibrincationic detergent complex was formed. The complex was soluble in distilled water, and was observed to be in a dispersed state by electron microscopy. The complex was precipitated and resolubilized in the presence of salt. This behavior of the complex was due to adsorption of the salt anions onto the complex. When an aqueous solution of the complex was incubated with fresh serum, the complex soon aggregated and then was converted into a firm clot which was not soluble in distilled water.

Blood↗

Interaction of fibrinogen with detergent.

Both cationic and anionic detergents were found to precipitate fibrinogen by forming fibrinogen-detergent complexes. These complexes were soluble in distilled water, but the aqueous solutions were very unstable and the complexes precipitated in the presence of salt. In the interaction of fibrinogen with the cationic detergent, stearyltrimethyl-ammonium chloride, approximately 160 molecules of detergent were found to bind to one molecule of fibrinogen. In distilled water, the fibrinogen-stearyltrimethylammonium complex (FG-STA(Cl)) remained soluble in the presence of thrombin [ED 3.4.21.5] although the same peptides were released as those released from fibrinogen. Precipitation of FG-STA(Cl) by salt was found to be closely related to adsorption of the anion of the salt by the complex. Futher addition of salt resulted in solubilization of the precipitate, and the solubilization was also due to further adsorption of the anion onto the precipitate.

Animals↗