Biomedical subjects

Y Inoue

Publications and source records attributed to Y Inoue.

At least 1,153 records · Page 64Linked to original sources

PubMed1993

The inhibitory effect of tolbutamide on phosphoenolpyruvate carboxykinase activity in rat hepatoma H4IIE cells.

Effects of tolbutamide on the activity of hepatic phosphoenolpyruvate carboxykinase (PEPCK), a rate limiting enzyme in gluconeogenesis, was examined using rat hepatoma (H4IIE) cells. Tolbutamide inhibited PEPCK activity induced by cAMP in a time- and dose-dependent manner. Tolbutamide effect was rapidly exerted and insulin-independent. The inhibitory effect of 5 mM tolbutamide corresponded with that of 10(-7) M insulin. These results suggest the possibility that tolbutamide plays a significant role on amelioration of the deranged glucose metabolism in the liver through repression of gluconeogenesis, primarily due to the inhibition of PEPCK activity.

Animals↗

PubMed1993

[MR imaging of pituitary dwarfism].

Pituitary MR imaging was performed in 32 patients with clinically diagnosed pituitary dwarfism and 12 normal controls. The patients were divided into two groups according to the severity of pituitary dwarfism based on endocrinological data. The two patients with severe dwarfism showed transection of the pituitary stalk, ectopic posterior lobe and atrophy of the anterior lobe on MR imaging, while the 27 patients with mild dwarfism showed no abnormal MR findings of the pituitary gland. The former group corresponds to typical pituitary dwarfism and the latter to partial GH deficiency, which was recently proposed as another type of pituitary dwarfism. In conclusion, pituitary MR imaging may differentiate partial GH deficiency from typical (stalk-transected) pituitary dwarfism.

Adolescent↗

PubMed1993

Binding and functional properties of two new extrinsic components, cytochrome c-550 and a 12-kDa protein, in cyanobacterial photosystem II.

Cytochrome c-550, a low-potential c-type cytochrome, and a 12-kDa protein were recently shown to be associated extrinsically and stoichiometrically with purified photosystem II (PSII) complex of the thermophilic cyanobacterium Synechococcus vulcanus [Shen, J.-R., Ikeuchi, M., & Inoue, Y. (1992) FEBS Lett. 301, 145-149]. The binding and functional properties of these two extrinsic components in PSII were studied by means of release-reconstitution and thermoluminescence techniques. The following results were obtained: (i) cyt c-550 rebound appreciably to cyanobacterial PSII in the absence of the 33- and 12-kDa extrinsic proteins, but the presence of these two proteins facilitated the rebinding, affording a full level of binding equal to that in native PSII. (ii) The 12-kDa protein did not rebind to PSII at all unless the 33-kDa protein or cyt c-550 was present. It rebound only partially in the presence of either of these two proteins, but it rebound maximally when reconstituted together with both of them. (iii) Reconstitution with cyt c-550 or the 12-kDa protein alone in the absence of the 33-kDa protein did not restore the O2-evolving activity of CaCl2-washed PSII. Reconstitution with cyt c-550 in combination with the 33-kDa protein appreciably enhanced the activity, but the activity restoration was much more marked and reached a level close to that of the original activity when all three extrinsic proteins were included.(ABSTRACT TRUNCATED AT 250 WORDS)

Bacterial Proteins↗

PubMed1993

Positive chronotropic and inotropic responses to BRL 37344, a beta 3-adrenoceptor agonist in isolated, blood-perfused dog atria.

We investigated the chronotropic and inotropic responses to BRL 37344 (a beta 3-adrenoceptor agonist) and isoproterenol in isolated, blood-perfused dog atria. BRL 37344 (0.1-30 nmol) or isoproterenol (0.001-0.3 nmol) increased the sinus rate and contractile force dose dependently. BRL 37344 was 290 times less potent than isoproterenol to increase sinus rate and 140 times less potent to increase atrial force. Both propranolol and bisoprolol similarly inhibited the positive chronotropic and inotropic responses to BRL 37344 and isoproterenol dose dependently. ICI 118,551 (0.1 and 1 nmol) did not significantly affect the positive cardiac responses to BRL 37344 or isoproterenol. Neither imipramine nor tetrodotoxin significantly affected the positive cardiac responses to BRL 37344. These results suggest that the positive chronotropic and inotropic responses to BRL 37344 are mediated mainly by beta 1-adrenoceptors in the dog heart. It is unlikely that beta 3-adrenoceptors, as previously reported in adipose tissue or gastrointestinal smooth muscle, mediate chronotropic and inotropic responses in the normal dog heart.

Adrenergic beta-Agonists↗

PubMed1993

Structural studies of a novel type of tetraantennary sialoglycan unit in a carbohydrate-rich glycopeptide isolated from the fertilized eggs of Indian Medaka fish, Oryzias melastigma.

A novel carbohydrate-rich sialoglycopolyprotein of apparent molecular mass approximately 7000 Da was isolated from the fertilized eggs of the Medaka fish species, Oryzias melastigma. The glycoprotein was identified as a member of the L-hyosophorin family because it exhibited the following several distinctive features of L-hyosophorin molecules: (a) it contains a high proportion of carbohydrate (90% by weight), and (b) the amino acid sequence of the apopeptide was identical with that of the Oryzias latipes L-hyosophorin which has previously been demonstrated to be derived from a high molecular weight form of hyosophorin, i.e. H-hyosophorin, present in the cortical vesicles of unfertilized eggs. The apoprotein of H-hyosophorin is composed of tandem repeats of the L-hyosophorin apopeptide, i.e. it is a polyprotein. The structure of the carbohydrate portion of purified L-hyosophorin of O. melastigma was studied by composition and methylation analysis, selective chemical (periodate-Smith degradation; hydrazinolysis-nitrous acid deamination), and enzymatic (endo-beta-galactosidase; peptide:N-glycanase) degradation, together with instrumental methods (fast atom bombardment-mass spectrometry and 1H NMR). O. melastigma L-hyosophorin was found to contain two types of large, branched tetraantennary glycan units capped with sialic acids. The two glycans differ with respect to the branching pattern of the trimannosyl core (x = 4 or 6 in Eq. A). [formula: see text] The possible physiological significance of the hyosophorin family is discussed in the light of their unique structural features.

Animals↗

PubMed1993

Synthesis of CMP-deaminoneuraminic acid (CMP-KDN) using the CTP:CMP-3-deoxynonulosonate cytidylyltransferase from rainbow trout testis. Identification and characterization of a CMP-KDN synthetase.

The sugar nucleotide, cytidine 5'-(3-deoxy-D-glycero-D-galacto-2-nonulosonic phosphate) (CMP-KDN) is expected to serve as a donor of KDN residues in the synthesis of KDN-containing glycoconjugates. We report here the identification and characterization of CMP-KDN synthetase, a novel enzyme responsible for synthesis of CMP-KDN from KDN and CTP. The enzyme was partially purified from the testis of rainbow trout (Oncorhynchus mykiss), where KDN gangliosides were first discovered (Yu, S., Kitajima, K., Inoue, S., and Inoue, Y. (1991) J. Biol. Chem. 266, 21929-21935), and used to synthesize CMP-[14C]KDN, which was characterized by 1H NMR. Vmax/Km studies showed that KDN was a preferred nonulosonic acid substrate compared to N-acetylneuraminic acid (Neu5Ac) or N-glycolylneuraminic acid (Neu5Gc) (4.4 x 10(-3) min-1 for KDN versus 2.3 and 1.8 x 10(-3) min-1 for Neu5Ac and Neu5Gc, respectively). CMP-KDN synthetase activity was maximal at pH 9-10 and at 25 degrees C. The presence of either Mg2+ or Mn2+ was essential for CMP-KDN synthetase activity. 25 mM Mg2+ stimulated formation of CMP-KDN more than 10-fold, yet only stimulated formation of CMP-Neu5Ac and CMP-Neu5Gc 4-fold, relative to 1 mM Mg2+. A kinetic study using mixed substrates showed that both CMP-KDN and CMP-Neu5Ac synthetase activities in the partially purified enzyme were due to the same active site of a single enzyme. In contrast, Neu5Ac and Neu5Gc were the preferred nonulosonic acid substrates for the calf brain CMP-sialic acid synthetase. Thus, mammalian CMP-sialic acid synthetases recognizes similar, yet distinctively different, substrate specificity determinants. Thus, the trout testis enzyme was considered to synthesize activated sugar nucleotides required for synthesis of both (KDN)GM3 and (Neu5Ac)GM3. The expression of CMP-KDN synthetase was shown to be temporally correlated with development and to parallel the developmental expression of (KDN)GM3 in sperm.

Animals↗

PubMed1993

Distribution of guanine nucleotide-binding protein in the brain of the reeler mutant mouse.

The localization of a GTP-binding protein (G(o)) in the cerebellar and cerebral cortex and hippocampus of the normal and reeler mutant mouse was immunohistochemically examined using affinity-purified antibody raised against the alpha subunit of G(o). Although the general distribution pattern of G(o)-immunoreactive products in the brain of the normal mouse, i.e., abundant in the neuropil but absent from neuronal cell bodies, is also seen in the reeler brain, some differences are present, as described below. Strong G(o)-immunoreactive products are found in the molecular layer of the cerebellar cortex of the normal mouse. In the reeler cerebellum, in addition to the strong G(o)-immunoreactivity of the thin molecular layer, moderate G(o)-immunoreactivities are also found in the granular cell layer and the central cerebellar mass. G(o)-immunoreactive products are distributed throughout all layers of the cerebral cortex of the normal and reeler mouse. However, layer I of the normal cerebral cortex is more strongly stained with this antibody than the underlying layers, whereas the upper third of the reeler cerebral cortex is more strongly stained than the lower two-thirds. In the hippocampus of the normal mouse, G(o)-immunoreactive products are localized in the neuropil of the stratum oriens, stratum radiatum and stratum lacunosum-moleculare, but absent from the cell bodies of the pyramidal cells and their apical dendritic shafts. Such a distribution pattern of G(o)-immunoreactive products is also seen in the hippocampus of the reeler mouse, except that G(o)-immunonegative pyramidal cells split into 2 or 3 laminae.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1993

Clinical significance of antibodies to nonstructural and core proteins of hepatitis C virus in posttransfusion hepatitis patients during long-term follow-up.

To clarify the long-term clinical significance, antibody to hepatitis C virus (HCV) was examined using core (p22) and nonstructural (C100-3) protein assays in sera of 18 patients with non-A,non-B posttransfusion hepatitis (PTH-NANB) who were selected retrospectively. Each patient had been followed for more than 5 years after the development of the disease. They were divided into three groups according to clinical outcome: acute hepatitis that resolved within 1 year, group 1 (n = 3); chronic hepatitis that resolved within 1-4 years, group 2 (n = 4); and chronic hepatitis that persisted for 5 years or longer, group 3 (n = 11). Sixteen of the 18 were positive for anti-C100-3 and anti-p22, one was positive for anti-p22 alone, and one was negative for both. In ten of the 16 (62.5%), anti-p22 appeared before anti-C100-3. The anti-C100-3 titer peaked about 12 months after disease onset in all cases and thereafter declined gradually, finally becoming negative in groups 1 and 2, while the titer fluctuated in group 3. The mean titer in group 3 at 12 months (69.2 units) significantly exceeded that of groups 1 (4 units) and 2 (8.2 units). Group 1 was seronegative for HCV antibodies and HCV RNA at the last examination, suggesting the cessation of HCV replication. Group 3 remained positive for those markers, indicating the continued replication of HCV.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1993

Endotoxin increases hepatic glutamine transport activity.

Glutamine uptake by the liver is accelerated during endotoxemia, but little is known regarding the influence of sepsis on the plasma membrane transport systems catalyzing hepatic glutamine uptake. We hypothesized that this augmented uptake was due to an increase in hepatocyte plasma membrane transport activity. We investigated the activities of the Na(+)-dependent transport System N (transports glutamine into the hepatocyte) and the Na(+)-independent System n (transports glutamine out of the cell) in hepatocyte plasma membrane vesicles (HPMVs) prepared from livers of rats treated with Escherichia coli endotoxin (LPS) in vivo. HPMVs were prepared by differential centrifugation and the transport of [3H]glutamine was assayed by a rapid mixing/filtration technique in the presence and absence of sodium. Vesicle integrity and functionality were confirmed by enzyme marker enrichments and classic "overshoots" in the presence of sodium. Carrier-mediated Na(+)-independent glutamine transport activity was not altered by LPS administration. In contrast, endotoxemia resulted in a time- and dose-dependent two- to threefold increase in Na(+)-dependent glutamine transport activity in HPMVs secondary to an increase in the transport Vmax, consistent with the appearance of increased numbers of corresponding transporter proteins in the hepatocyte plasma membrane. The Km (affinity for glutamine) of the System N transporter was not affected by LPS treatment. Maximal increases in transport were observed 4 hr after exposure to endotoxin. System N transport activity returned to basal levels by 12 hr. This increase in transport activity represents an important mechanism regulating the accelerated hepatic glutamine uptake that occurs during severe infection.

Animals↗

PubMed1993

Functional analysis of the gamma-glutamylcysteine synthetase of Escherichia coli B: effect of substitution of His-150 to Ala.

A high expression system of the gamma-glutamylcysteine synthetase gene (gshl) of Escherichia coli B was constructed, and rapid purification of GSH-I was performed. The active site of GSH-I was analysed by chemical modification, and Lys, Arg and His residues seemed to be involved in the active site of the enzyme. Among them, His residues were substituted to Ala by site-directed mutagenesis, and His-150 was found to be essential for the activity of GSH-I.

Alanine↗

PubMed1993

A new enzyme-linked immunosorbent assay (ELISA) for studying immunocytochemical procedures using an antiserum produced against spermidine as a model.

Antiserum was produced in rabbits against the polyamine spermidine (Spd) conjugated to bovine serum albumin (BSA). The reactivity of the serum to Spd and a variety of structurally related compounds was quantified by a new immunocytochemical model system incorporating an enzyme-linked immunosorbent assay (ELISA) binding test. This is based on the principle of coupling these compounds to the wells of microtiter plate activated with poly-L-lysine and glutaraldehyde and incubating the wells by the indirect immunoperoxidase method. The antiserum showed a 25% cross reaction with spermine (Spm), putrescine (Put), and cadaverine (Cad), and a 1% cross reaction with 1,3-diaminopropane (Dap), but no cross reaction with monoacetyl polyamines and amino acids. The antibody binding was inhibited most effectively by absorption of the antiserum with N1-acetylspermidine and Spd in the ELISA inhibition test. Also, immunoblot analysis of the antiserum with nitrocellulose paper gave completely identical results to the ELISA binding tests. Spd-like immunoreactivities in human melanoma BD and neuroblastoma IMR 32 cell lines are presented as examples of the staining pattern obtained with the antiserum. Absorption of the serum with N1-acetylspermidine and Spd was demonstrated to abolish the immunostaining reaction. The immunohistochemical model is simple: amines and amino acids are bound in the same way as in aldehyde-fixed tissues and, in comparison to immunoblot analysis, the immunoreactivity can be more easily and accurately quantified by assay with the antibody. The model should prove useful in assessing the specificity of other antisera.

Enzyme-Linked Immunosorbent Assay↗

PubMed1993

Immunoelectron microscopic localization of the HPC-1 antigen in rat cerebellum.

HPC-1 antigen is a neuron-specific 34 kDa protein, identical to p35A (syntaxin), and is thought to play important roles in docking or fusion of synaptic vesicles to presynaptic active zones. In the present study we analyze the distribution of HPC-1 antigen in rat cerebellum by a cryoimmunogold technique using an antibody against the fusion protein of beta-galactosidase and the HPC-1 antigen. HPC-1 antigen was detected at high density on the plasma membranes and synaptic vesicles of presynaptic boutons which formed synapses with dendrites of Purkinje cells, and on the plasma membranes of parallel fibres in the cerebellar molecular layer. In the granule cell layer, gold particles were also detected on the endoplasmic reticulum, nuclear membranes and the plasma membranes of granule cells. Presynaptic membranes and synaptic vesicles in glomeruli were also labelled by gold particles. To determine the topology of HPC-1 antigen on the membranes, the synaptosome fraction prepared from rat cerebellum was embedded in agarose, and processed for the pre-embedding protein A-gold technique. Intact synaptosomes were not labelled by gold particles. However, when fixed in hypotonic fixative to rupture plasma membranes, or when ruptured after fixation in normotonic fixative, the cytoplasmic surfaces of presynaptic membranes and synaptic vesicles were labelled by gold particles. These results suggest that most of the epitopes of HPC-1 antigen are located on the cytoplasmic surface of plasma membranes and synaptic vesicle membranes.

Animals↗

PubMed1993

The pharmacokinetics of primaquine in calves after subcutaneous and intravenous administration.

The pharmacokinetics of primaquine was studied in calves of 180-300 kg live weight. Primaquine was injected at 0.29 mg/kg (0.51 mg/kg as primaquine diphosphate) intravenously (IV) or subcutaneously (SC) and the plasma concentrations of primaquine and its metabolite carboxyprimaquine were determined by high-performance liquid chromatography. The extrapolated concentration of primaquine at zero time after IV administration was 0.50 +/- 0.48 microgram/ml (mean +/- SD) which decreased with an elimination half-life of 0.16 +/- 0.07 h. Primaquine was rapidly converted to carboxyprimaquine after either route of administration. The peak concentration of carboxyprimaquine was 0.50 +/- 0.08 microgram/ml at 1.67 +/- 0.15 h after IV administration. The corresponding value was 0.47 +/- 0.07 micrograms/ml at 5.05 +/- 1.20 h after SC administration. The elimination half-lives of carboxyprimaquine after IV and SC administration were 15.06 +/- 0.99 and 12.26 +/- 3.06 h, respectively. The areas under the concentration-time curve for carboxyprimaquine were similar following either IV or SC administration of primaquine; the values were 11.85 +/- 2.62 micrograms.h/ml after the former and 10.95 +/- 2.65 micrograms.h/ml after the latter. The mean area under the concentration-time curve for primaquine was less than 0.1 micrograms.h/ml after either route of administration.

Animals↗

PubMed1993

Effect of etodolac on type-II collagen-induced arthritis in mice.

We tested the effect of etodolac on the development of type-II collagen-induced arthritis in DBA/1J mice. It was administered orally once daily for 35 days after the primary immunization with type-II collagen. Etodolac (10 mg/kg) significantly inhibited the development of signs of arthritis on day 28 to day 35. Indomethacin (1 mg/kg) also significantly inhibited it on day 29 to day 34. Radiographic examination showed that etodolac (10 mg/kg) significantly prevented the development of osteopenia, bone erosion and new bone formation of the joints on day 35, while indomethacin (1 mg/kg) significantly prevented only the development of bone erosion. Histopathological examination showed that both etodolac (10 mg/kg) and indomethacin (1 mg/kg) significantly prevented the development of synovitis, erosion of cartilage of the joints and bone destruction of the limbs on day 35. Etodolac and indomethacin did not affect the serum level of anti-type-II collagen antibodies. These results suggest that etodolac and indomethacin suppress type-II collagen-induced arthritis without affecting humoral immune responses.

Animals↗

PubMed1993

Mechanism of acute deterioration of the neurological status following rapid and massive intraluminal thrombosis in case of a giant intracavernous carotid artery aneurysm: demonstration by MR imaging.

A case is reported of a thrombosed giant aneurysm of the intracavernous carotid artery. Transient neurological deterioration was attributable to the acute swelling of the aneurysmal mass after rapid and massive intraluminal thrombosis. Characteristics on the magnetic resonance imaging of this case are reported and discussed.

Acute Disease↗

PubMed1993

Biosynthesis of polyesters from various amino acids by Alcaligenes eutrophus.

The possibilities of the biosynthesis of polyesters from 20 kinds of naturally occurring L-amino acids by Alcaligenes eutrophus were studied. It was found that several amino acids were used efficiently to synthesize copolyesters of 3-hydroxybutyrate (3HB) and 3-hydroxyvalerate (3 HV) by A. eutrophus under the 'loose nitrogen-limiting' condition, but the other amino acids were scarcely utilized as a carbon source for the synthesis of polyesters. When L-threonine or L-isoleucine were used as the sole carbon source, copolyesters with higher 3HV content were produced.

3-Hydroxybutyric Acid↗

PubMed1993

Abnormal synaptic architecture in the cerebellar cortex of a new dystonic mutant mouse, Wriggle Mouse Sagami.

The 'Wriggle Mouse Sagami (WMS)' is a new neurological mutant with severe dystonic movements of the trunk and extremities whose pathological characters are transmitted by an autosomal recessive gene (wri). Manifestations first appear at 10 days to 2 weeks after birth and progress until 12 weeks of age. In spite of the severe dystonic movements, no marked abnormalities had been found in the cyto- or myeloarchitecture of the central nervous system or that of the peripheral nerves, except for the impaired development of the dendritic trees of the Purkinje cells. In this study we quantitatively demonstrated decreased synaptic connections of parallel fibers on the dendritic spines of the Purkinje cells as early as 2 weeks after birth. On the other hand, synaptic boutons on the dendritic shafts and somata of the Purkinje cells and synaptic bouton-like structures which contained synaptic vesicles but without synaptic membrane specialization, were significantly increased in the molecular layer at 9 weeks of age. Glutamic acid decarboxylase immunohistochemistry suggested that some of these increased synaptic boutons and other bouton-like structures may have originated in GABA interneurons, such as stellate cells, basket cells and Golgi cells, and in the cerebellar nuclei. Because of the severity of the manifestations, it appears that synaptic alteration in interneurons also occurs in the other parts of the CNS.

Animals↗

PubMed1993

Isolation of different non-cytopathogenic bovine viral diarrhoea (BVD) viruses from cytopathogenic BVD virus stocks using reverse plaque formation method.

Non-cytopathogenic (NCP) bovine viral diarrhoea (BVD) viruses were isolated from three cytopathogenic (CP) BVD virus stocks using the reverse plaque formation method, which was based on intrinsic interference. By means of an exaltation of Newcastle disease virus (END) test, these NCP BVD viruses were divided into two groups; END phenomenon positive (END+) and END phenomenon negative (END-) viruses. Additionally, the END+ NCP BVD viruses interfered only with CP BVD virus whereas the END- NCP BVD viruses interfered with vesicular stomatitis virus as well as CP BVD virus. Differences in antigenicity existed among the three CP strains, however, each group of parent CP BVD virus and derivative NCP BVD virus was antigenically indistinguishable.

Animals↗