Biomedical subjects

S Inoue

Publications and source records attributed to S Inoue.

At least 973 records · Page 54Linked to original sources

PubMed1992

[Recurrent ischemia after acute myocardial infarction: clinical profile and significance of electrocardiographic ST changes during the attacks].

This study investigated the clinical characteristics of acute myocardial infarction (AMI) complicated by recurrent ischemia, especially relating to the electrocardiographic ST changes during the attacks. Fifty-six patients with AMI were complicated by recurrent ischemia (ischemia group), and 238 were not (non-ischemia group). The ischemia group was preceded by prior episodes of angina or myocardial infarction in 88%, as compared with 65% in the non-ischemia group (p less than 0.05). There were non Q wave infarction in 45% of the ischemia group, and 24% of the non-ischemia group (p less than 0.05). The overall in-hospital mortality rate was similar in the ischemia group (13%) and in the non-ischemia group (17%), although the causes were predominantly pump failure in the former and cardiac rupture in the latter. ST segment elevation occurred in 29 patients and ST depression occurred in 26 patients of the ischemia group during the attacks. Multivessel coronary arterial lesions were more frequently present in the latter subgroup than the former (38% vs 79%, p less than 0.05). The in-hospital cardiac deaths were also more frequently noted in the latter subgroup. Recurrent ischemia after AMI with concomitant electrocardiographic ST depression is a high risk subgroup, and, therefore, aggressive revascularization procedures may be indicated in such cases if suitable.

Coronary Vessels↗

PubMed1992

[Control of house dust mites and mite allergens by special mite-preventive futon].

We studied the effect of a recently-developed special mite-preventive futon (bedding) on mite population and mite allergen contents (Der I and Der II) in asthmatic children and their families (23 sets) for 2 years. 1. The number of mites (vacuumed samples) in the 124 sets of futon for 2 years was 6.4 (SD +/- 8.8) in average in the mite-preventive futon which was significantly smaller than the number (about 1/10) in the control futon: 70.0 (SD +/- 99) (p less than 0.001). 2. Follow-up studies were made on the mite population about 2 years (3, 6, 9 12 and 27 months afterwards). The numbers of mites in all the mite-preventive futon was always 1/10 or less than that of in the control futon (p less than 0.01). 3. The mite allergens (Der I and Der II) were measured in the cotton stuffing of the futon used for 2 years. The mite allergen counts in the mite-preventive futon averaged about 1/24 of those in the control futon. 4. Airborne mite allergens (Der I and Der II) obtained by beating the futon were measured. The ratio of the mite allergen count in the mite-preventive futon to the control futon was found to be 1:22-264. These results indicate that the special mite-preventive futon always inhibit mite infestation at least 1/10 of that in the ordinary (control) futon and that the count of mite allergens in the cotton stuffing and in the airborne particles was even lower in the mite-preventive futon.

Adult↗

PubMed1992

[Quantitative evaluation of human placental aromatase during pregnancy by ELISA].

To examine the relationship between the modulation of estrogen synthesis and placental maturation during pregnancy, we measured enzyme quantities and catalytic activities of aromatase in 78 normal human placentas (7-41 weeks gestation). The quantity was determined by ELISA with monoclonal antibodies specific to aromatase cytochrome P-450 (P-450arom). The activity was assessed by radioassay with [1 beta-3H] androstenedione. Intracellularly, the P-450arom concentration was twice as great in the microsomal fraction of term placentas (0.18 +/- 0.07%) as in the homogenate and mitochondrial fractions. Aromatase activity was also twice as great in the microsomal fraction as in the other fractions. The P-450arom concentration in microsomes increased linearly as pregnancy progressed (r = 0.759, p less than 0.001). The total P-450arom quantity in the placenta increased quadratically as pregnancy progressed (r = 0.891). Similar results were observed for aromatase activity. These results indicated that the increase in P-450arom was responsible for the increase in aromatase activity in normal human placenta. Therefore, in addition to the increase in placental weight and substrate derived from fetal adrenal during pregnancy, a further increase in P-450arom contributes to the marked increase in maternal estrogen production.

Adrenal Glands↗

PubMed1991

Peptide:N-glycosidase activity found in the early embryos of Oryzias latipes (Medaka fish). The first demonstration of the occurrence of peptide:N-glycosidase in animal cells and its implication for the presence of a de-N-glycosylation system in living organisms.

The recent discovery of free oligosaccharides typical for the complex type of glycan chains terminating with a free di-N-acetylchitobiosyl structure in certain fish eggs and early embryos (Ishii, K., Iwasaki, M., Inoue, S., Kenny, P. T. M., Komura, H., and Inoue, Y. (1989) J. Biol. Chem. 264, 1623-1630; Seko, A., Kitajima, K., Iwasaki, M., Inoue, S., and Inoue, Y. (1989) J. Biol. Chem. 264, 15922-15929; Inoue, S., Iwasaki, M., Ishii, K., Kitajima, K., and Inoue, Y. (1989) J. Biol. Chem. 264, 18520-18526) led us to find an enzyme responsible for detachment of N-linked glycan chains from glycoproteins by hydrolyzing the beta-aspartyl-glucosylamine linkage in Oryzias latipes embryos. The enzyme, peptide-N4-(N-acetyl-beta-glucosaminyl) asparagine amidase or peptide:N-glycosidase (PNGase), was partially (2090-fold) purified, and the reaction site at which this enzyme acts was specified by analysis and identification of the reaction products. This is the first demonstration showing PNGase in animal sources, although the presence of PNGases was reported in a variety of plant extracts and bacteria. Thus, the commonality of this type of enzyme is now demonstrated, and the possible physiological role of PNGase in de-N-glycosylation as a basic biologic process is proposed.

Amidohydrolases↗

PubMed1991

Isolation and structural elucidation of a novel type of ganglioside, deaminated neuraminic acid (KDN)-containing glycosphingolipid, from rainbow trout sperm. The first example of the natural occurrence of KDN-ganglioside, (KDN)GM3.

Rainbow trout sperm contained almost exclusively monoanionic ganglioside fraction as a major acidic glycosphingolipid. Two monoacidic gangliosides were isolated and purified in this study and designated as sperm ganglioside 1 and 2 (sg-1 and sg-2). The two gangliosides, sg-1 and sg-2, contained the same neutral sugars, galactose and glucose in molar ratio of 1:1 and no GalNAc except for the presence of N-acetyl-neuraminic acid (NeuAc) in sg-1 and deaminated neuraminic acid (KDN; 2-keto-3-deoxy-D-glycero-D-galacto-nononic acid) in sg-2. The complete structures of these gangliosides were determined by a combination of methylation analysis, fast atom bombardment mass spectrometry, 400-MHz one- and two-dimensional 1H nuclear magnetic resonance spectroscopy, fatty acid analysis, and endoglycoceramidase digestion NeuAc alpha 2----3Gal beta 1----4Glc beta 1----Cer sg-1 [(NeuAc)GM3] KDN alpha 2----3Gal beta 1----4Glc beta 1----Cer sg-2 [(KDN)GM3] where, for both sg-1 and sg-2, the ceramide moieties (Cer) were found to be made up of 4-sphingenine and mainly C16:0 fatty acid (palmitate; 95%) with a minor amount of C24:1 fatty acyl chain (nervonate, 5%). The structure of sg-2 is novel and represents the first example of a new class of gangliosides, i.e. KDN-gangliosides.

Animals↗

PubMed1991

Identification of free glycan chain liberated by de-N-glycosylation of the cortical alveolar glycopolyprotein (hyosophorin) during early embryogenesis of the Medaka fish, Oryzias latipes.

In Medaka embryos (at the stages of blastulation to organogenesis), we found the presence of free glycan of which structure is identical with the multiantennary N-linked sugar chain of L-hyosophorin molecules which were originally present in the cortical alveoli of the unfertilized eggs in their precursor high molecular form. The free glycan-enriched fraction was separated from L-hyosophorin by chromatography on DEAE-Sephadex A-25 and Sephadex G-50 after removal of the sialic acid residues with exo-sialidase. Composition analysis, 400-MHz 1H NMR spectroscopy, and pyridylamination-hydrazinolysis-nitrous acid deamination of the free glycan showed the presence of di-N-acetylchitobiosyl structure at the reducing end, suggesting that the free glycan chain was derived from L-hyosophorin by the action of a specific peptide:N-glycosidase (PNGase). When we combine the previous finding of the hyosophorin-derived unique pentaantennary free glycan chain in the flounder embryos [A. Seko et al. (1989) J. Biol. Chem. 264, 15922-15929], it is anticipated that PNGase-catalyzed de-N-glycosylation of L-hyosophorin would be required at a certain stage of embryogenesis for L-hyosophorin to play a yet undefined functional role during early development.

Amino Acid Sequence↗

PubMed1991

Effect of hypothalamic administration of growth hormone-releasing factor (GRF) on feeding behavior in rats.

To examine the role and working site of growth hormone-releasing factor (GRF) in feeding behavior, we first tested the effect of the intracerebroventricular (i.c.v.) injection of GRF on food intake after 24 h of food deprivation. Cumulative food intake was measured 1, 3 and 6 h after injection. A lower dose of GRF stimulated food intake in a dose dependent manner (3 h; GRF 100 pmol 8.64 +/- 1.06 g vs saline 5.50 +/- 0.60 g, P less than 0.05), while a higher dose (1 nmol, 500 pmol) suppressed food intake (3 h; GRF 1 nmol 2.65 +/- 0.70 g vs saline 5.50 +/- 0.60 g, P less than 0.01). Second, the effect of i.c.v. injection of 100 pmol of GRF on peripheral metabolites was examined. The subsequent levels of plasma insulin, glucagon, glucose and non-esterified fatty acid showed no significant difference from those of saline administration. Third, the effect of microinjection of GRF (5 pmol) into several hypothalamic areas on food intake was examined. Injection into the ventromedial hypothalamic nucleus (VMN) stimulated food intake (3 h; GRF 5 pmol 10.32 +/- 1.04 g vs saline 6.92 +/- 0.32 g, P less than 0.05), but no significant effect was observed following injection either into the lateral hypothalamic area (LHA), paraventricular nucleus (PVN) or medial preoptic area (MPOA). Finally, we tested the stimulatory effect of GRF on food intake in bilateral VMN lesioned rats. I.c.v. injection in these animals had no more significant effect on food intake than did saline injection in VMN lesioned rats (3 h; GRF 100 pmol 6.27 +/- 0.87 g vs saline 5.34 +/- 0.44 g).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1991

Involvement of calcium in the mevalonate-accelerated degradation of 3-hydroxy-3-methylglutaryl-CoA reductase.

3-Hydroxy-3-methylglutaryl-coenzyme A reductase (HMG-CoA reductase), the rate-limiting enzyme in the biosynthesis of cholesterol and isoprenoids, is subject to rapid degradation which is regulated by mevalonate (MVA)-derived metabolic products. HMG-CoA reductase is an integral membrane protein of the endoplasmic reticulum, the largest nonmitochondrial pool of cellular Ca2+. To assess the possible role of Ca2+ in the regulated degradation of HMG-CoA reductase, we perturbed cellular Ca2+ concentration and followed the fate of HMG-CoA reductase and of HMGal, a fusion protein consisting of the membrane domain of HMG-CoA reductase and the soluble bacterial enzyme beta-galactosidase. The degradation of HMGal mirrors that of HMG-CoA reductase, demonstrating that the membrane domain of HMG-CoA reductase is sufficient to confer regulated degradation (Skalnik, D.G., Narita, H., Kent, C., and Simoni, R.D. (1988) J. Biol. Chem. 263, 6836-6841; Chun, K.T., Bar-Nun, S., and Simoni, R.D. (1990) J. Biol. Chem. 265, 22004-22010). In this study we show that the MVA-dependent accelerated rates of degradation of HMG-CoA reductase and HMGal in cells maintained in Ca(2+)-free medium are 2-3-fold slower than the rate of degradation in cells grown in high (1.8-2 mM) Ca2+ concentration. This effect is reversed upon addition of Ca2+ to the medium. Furthermore, when cells maintained in high Ca2+ are treated with 1 microM ionomycin, the MVA-dependent accelerated degradation of HMG-CoA reductase and HMGal is also reduced about 2-3-fold. This inhibition is not due to a Ca(2+)-dependent uptake or incorporation of MVA into sterols, since these processes are not affected in the absence of external Ca2+. In addition, cobalt, a known antagonist of Ca(2+)-dependent cellular functions, totally abolishes (IC50 = 520 microM in the presence of 1.8 mM extracellular Ca2+) the MVA-accelerated degradation of HMGal. These results suggest that Ca2+ plays a major role in the regulated degradation of HMG-CoA reductase.

Animals↗

PubMed1991

Isolation of estrogen receptor-binding sites in human genomic DNA.

Total genomic DNA digested by restriction enzymes was mixed with the DNA-binding domain of the estrogen receptor (ER-DBD) that was expressed in Escherichia coli and the fragments that bound to it were selected by nitrocellulose filter. These fragments were cloned into a plasmid vector and amplified. This selection process was repeated six times and five fragments ranging from 0.2 to 2 kb were isolated. Interestingly, each of these fragments had a perfect palindromic estrogen responsive element (ERE) (GGT-CANNNTGACC). More surprisingly, one of the fragments was found to be derived from the same locus as a fragment obtained by another similar but independent experiment. The results indicate that the ER-DBD region can bind by itself specifically to the perfect palindromic ERE with a 3 base pair spacing but it does not bind strongly enough to the half palindromic EREs or to the imperfect palindromic EREs. Chloramphenicol acetyltransferase assay has shown that some of these fragments have estrogen-dependent enhancer activity, suggesting the existence of a target gene near these fragments. The method described here may be generally applicable for screening and isolation of other transcription factor-binding sites in genomic DNA.

Amino Acid Sequence↗

PubMed1991

Inhibition of degradation of 3-hydroxy-3-methylglutaryl-coenzyme A reductase in vivo by cysteine protease inhibitors.

3-Hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase is a key regulatory enzyme of cholesterol biosynthesis and is located in the endoplasmic reticulum (ER). A fusion protein, HMGal, consisting of the membrane domain of HMG-CoA reductase fused to Escherichia coli beta-galactosidase and expressed in Chinese hamster ovary (CHO) cells from the SV40 promoter, was previously constructed and was found to respond to regulatory signals for degradation in a similar fashion to the intact HMG-CoA reductase. Degradation of both HMG-CoA reductase and HMGal in CHO cells was enhanced by addition of mevalonate or low density lipoprotein (LDL). In this report we show that 2 cysteine protease inhibitors, N-acetyl-leucyl-leucyl-norleucinal (ALLN) and N-acetyl-leucyl-leucyl-methioninal (ALLM), completely inhibit the mevalonate- or LDL-accelerated degradation of HMG-CoA reductase and HMGal and also block the basal degradation of these enzymes. It has been shown that in vitro these protease inhibitors inhibit the activities of Ca(2+)-dependent neutral proteases as well as lysosomal proteases, including cathepsin L, cathepsin b, and cathepsin D. However, the mevalonate-accelerated degradation of HMG-CoA reductase and HMGal is not affected by lysosomotropic agents, suggesting that the site of action of these inhibitor peptides in preventing the degradation is not the cathepsins. In brefeldin A-treated cells, where protein export from the ER is blocked, ALLN is still effective in inhibiting the degradation of HMG-CoA reductase and HMGal. These results indicate the involvement of non-lysosomal Ca(2+)-dependent proteases in the basal and the accelerated degradation of HMG-CoA reductase and HMGal. Enzymatic assays in vitro and immunoblot analyses have revealed calpain- and calpastatin-like proteins in CHO cells. The activities and the amount of these proteins do not change under conditions of enhanced degradation, indicating that the levels of these proteins are not subject to mevalonate regulation.

Animals↗

PubMed1991

Comparison of DNA contents of visceral organs in rats with ventromedial hypothalamic lesions and fed a high fat diet.

Bilateral lesions of ventromedial hypothalamus are followed by a number of changes including vagal hyperactivity and hyperinsulinemia. To investigate if cell proliferation occurs in visceral organs in rats with ventromedial hypothalamic (VMH) lesions and fed a high fat diet, we determined DNA contents of visceral organs (liver, pancreas, small and large intestines, spleen, kidney and heart) 1 and 4 week after VMH lesions or start of high fat diet. In rats with VMH lesions, DNA contents increased significantly in liver, pancreas, and small and large intestines at 1 week, and maintained the same levels until the 4th week. DNA contents increased most in the pancreas, followed by small and large intestines, and liver. DNA content did not change in spleen, kidney, or heart. In rats fed a high fat diet, there was no increase in the DNA content of these organs, except in the small intestine at 4 weeks. The results suggest that VMH lesions produce excessive DNA synthesis in visceral organs, whereas a high fat diet does not. VMH lesions may induce cell proliferation in visceral organs through vagal hyperactivity and/or changes of humoral growth factors.

Animals↗

PubMed1991

Suppression of penicillin-induced lysis of Staphylococcus aureus by cibacron blue 3G-A.

The effect of cibacron blue 3G-A (CB) on bacteriolysis induced by penicillin G was investigated using Staphylococcus aureus FDA 209P. Penicillin-induced lysis was completely inhibited by 30 microM CB. However, the bactericidal effect of penicillin G was not influenced by CB. These results indicate that a bacteriolytic process is not essential for penicillin to kill S. aureus.

Bacteriolysis↗

PubMed1991

Amino acid sequences of nerve growth factors derived from cobra venoms.

Amino acid sequences of nerve growth factors (NGFs), purified from the venoms of Indian cobra (Naja naja) and Thailand cobra (Naja naja siamensis) were determined. The sequence of N. naja NGF differed from that reported previously by Hogue-Angeletti et al. [(1976) Biochemistry 15, 26-34]. The sequence of N. naja siamensis NGF was identical to that of Formosan cobra Naja naja atra NGF, determined previously by Oda et al. [(1989) Biochem. Int. 19, 909-917] and to that deduced from the nucleotide sequence of an NGF cDNA from the venom gland of N. naja siamensis, as reported by Selby et al. [(1987) J. Neurosci. Res., 18, 293-298].

Amino Acid Sequence↗

PubMed1991

Molecular cloning and sequencing of the epidermal cell differentiation inhibitor gene from Staphylococcus aureus.

We recently purified to homogeneity a protein inhibiting differentiation of cultured keratinocytes from extracellular products of Staphylococcus aureus, and named it epidermal cell differentiation inhibitor (EDIN). In the present study, we isolated and sequenced the structural gene coding for EDIN from Staphylococcus aureus E-1 using oligonucleotide probes on the basis of the partial amino acid sequence of the purified EDIN. DNA sequencing of the cloned DNA revealed an open reading frame encoding 247 amino acids as a precursor of EDIN, which included an NH2-terminal signal sequence of 35 amino acid residues. Processing of this precursor produces a mature EDIN protein composed of 212 amino acids with a calculated Mr of 23,782. The EDIN shared 35% amino acid homology with the ADP-ribosyltransferase C3 of Clostridium botulinum. These results with biological properties of EDIN described previously indicate that EDIN is a novel protein.

Amino Acid Sequence↗

PubMed1991

Amino acid sequences of the two subunits of a phospholipase A2 inhibitor from the blood plasma of Trimeresurus flavoviridis. Sequence homologies with pulmonary surfactant apoprotein and animal lectins.

Phospholipase A2 inhibitor (PLI), purified from the blood plasma of the Habu snake (Trimeresurus flavoviridis), was separated into two distinct subunits, PLI-A and PLI-B. These subunits were shown to be glycoproteins with molecular weights of around 21,000-22,000. When they were deglycosylated chemically with trifluoromethanesulfonic acid, the molecular weights were found to be 17,000. Their amino acid sequences were determined by alignment of peptides obtained by lysyl endopeptidase digestion and Staphylococcus aureus V8 protease digestion. PLI-A and PLI-B were each composed of 147 amino acid residues with one residue, Asn103, being for N-linked glycosylation, and the molecular weights of their protein portions were calculated to be 16,368 and 16,408, respectively. Each subunit contained four cysteine residues, all of which exist in disulfide linkages (Cys64-Cys141 and Cys119-Cys133). The sequences of PLI-A and PLI-B showed 89.9% homology to each other. When the sequences were compared with those of lipocortins, no significant homologies were detected. But the sequences were significantly homologous to those of COOH-terminal carbohydrate recognition portions of pulmonary surfactant apoprotein and animal lectins.

Amino Acid Sequence↗

PubMed1991

Time-resolved fluorometric sandwich immunoassay for human growth hormone in serum and urine.

A specific and sensitive time-resolved fluorometric sandwich immunoassay for human growth hormone (hGH) in serum and urine is described. A monoclonal anti-hGH IgG1 (5802)-coated polystyrene ball was incubated with serum or dialyzed urine and subsequently with europium ion-labeled monoclonal anti-hGH IgG1 (5801). Europium ion bound to the polystyrene ball was measured by time-resolved fluorometry. The detection limit of hGH was 0.3 pg/tube, which was 15-fold higher than that by sandwich enzyme immunoassay using horseradish peroxidase as label. The assay range of serum hGH was 15-15,000 ng/liter using 20 microliters of serum. The assay range of urinary hGH was 2-2,000 ng/liter using 150 microliters of dialyzed urine. The detection limits of hGH in serum and urine by this immunoassay were satisfactory for measuring hGH levels in serum and urine of healthy children and in serum of healthy adults and higher levels but not in urine of healthy adults and in serum and urine of patients with hGH deficiency.

Adolescent↗

PubMed1991

Effect of ecdysterone on histamine release from rat peritoneal mast cells.

Ecdysterone dose-dependently inhibited anti-IgE-induced histamine release from mast cells. Moreover, the rate and extent of histamine release from mast cells induced by Concanavalin A (Con A) are significantly diminished in samples incubated with ecdysterone. Ecdysterone inhibited both the initial and gradual rise in fluorescent response by anti-IgE and Con A. The effects of ecdysterone on the fluorescence response was correlated with the inhibition of histamine release. These results suggest the possibility that the inhibition of histamine release from rat mast cells by ecdysterone might be due to inhibition of Ca2+ mobilization from intracellular Ca2+ storage.

Animals↗

PubMed1991

Pentosome--a new connective tissue component--is a subunit of amyloid P.

A new minute connective tissue structure, referred to as "pentosome", has been investigated by electron microscopy and its nature has been examined by immunoperoxidase tests. Pentosomes are 3.5-nm wide, particulate structures that have been observed in the posterior chamber of the eye, the connective tissue spaces of the mouse foot-pad and the matrix of the mouse EHS tumor. They are usually found in the vicinity of microfibrils whether they are free or associated with elastic fibers. They tend to be organized into groups forming a three-dimensional semi-crystalline lattice at 10-nm intervals, but are connected by fine filaments. At high magnification, pentosomes appear as hollow structures composed of two parallel pentagons, which respectively measure 2.7 and 3.5 nm, and are held together by a cross-bar. A series of immunoperoxidase tests has only shown antigenicity against a serum protein, the amyloid P component. However, pentosomes are only about one-third the size of the 8.5-nm wide, disk-like segments of the amyloid P molecule. Since they could be subunits of these molecules, such subunits were prepared and compared with pentosomes; they appeared to be identical. It is concluded that the pentosomes found in connective tissue are AP subunits.

Animals↗