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Biomedical subjects

S Inoue

Publications and source records attributed to S Inoue.

At least 343 records · Page 19Linked to original sources
PubMed1999

NMDA receptor type 2D gene as target for estrogen receptor in the brain.

Although it is well known that estrogen exerts its effect in the brain, the direct target genes transcriptionally regulated by estrogen or rather estrogen receptor (ER) are almost unknown. During the search for estrogen receptor-binding sites from human CpG island library, we found one genomic DNA fragment corresponding to the putative 3'-untranslated region of human NMDA receptor subunit 2D (NR2D) gene. It contained at least four half palindromic estrogen responsive elements (hEREs) within two hundred nucleotides, which was conserved also in the rat. Interestingly, the NR2D mRNA is co-localized with ERalpha and/or ERbeta mRNA in a number of regions of rat brain. We have also demonstrated that NR2D mRNA is up-regulated in rat hypothalamus by estrogen possibly via hEREs identified here. Thus, we suggest that NR2D is one of the direct targets of estrogen receptors which are involved in reproductive as well as non-reproductive actions in the brain.

Animals↗
PubMed1999

Fluorescent-assisted detection of oligosialyl units in glycoconjugates.

A highly sensitive chemical method to detect various types of oligo/polysialic acid (oligo/polySia) units in glycoconjugates, i.e., alpha2 --> 8-linked homo-oligo/polySia [N-acetylneuraminic acid (Neu5Ac), N-glcolylneuraminic acid (Neu5Gc), or 2-keto-3-deoxy-d-glycero-d-galacto-nononic acid], alpha2 --> 8-linked heterodimers of Neu5Ac and Neu5Gc, alpha2 --> 9-linked homooligo/polyNeu5Ac, and alpha2 --> 5-Oglycolyl-linked homooligo/polyNeu5Gc, was developed with an alpha-keto acid-reactive fluorescent labeling reagent, 1,2-diamino-4,5-methylenedioxybenzene (DMB). Fluorescent labeled di- or oligoSia was separated and quantitated by fluorometric anion-exchange high-performance liquid chromatography (HPLC). As little as 13 fmol of Neu5Acalpha2 --> 8Neu5Ac was detectable by this method. When alpha2 --> 8-linked oligo/polyNeu5Ac with on average eight Neu5Ac residues was labeled with DMB, DMB derivatives of oligomers with only lower degrees of polymerization of 2 to 7, were detected, due to concomitant partial depolymerization of oligo/polySia chain with the derivatization. For glycoproteins and glycolipids, mild acid hydrolysis was performed to release oligoSia prior to DMB derivatization. The mild acid hydrolysis/fluorometric HPLC method was also applicable to glycoprotein samples blotted on the membrane.

Animals↗
PubMed1999

Effect of coenzyme Q10 in patients with mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS): evaluation by noninvasive tissue oximetry.

We evaluated the effect of coenzyme Q10 supplementation to two patients with mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) by using noninvasive tissue oximetry with near-infrared spectra of hemoglobin from the quadriceps muscle during bicycle ergometer exercise. Patients showed distinct oxygen consumption patterns reflecting the defect in oxidative phosphorylation and the impairment in oxygen utilization during exercise. Based on the oxygen consumption pattern, we considered one patient as having severe mitochondrial disorder and another patient as having mild one. After coenzyme Q10 supplementation, the oxygen consumption pattern of the patient with the severe form shifted to the mild one, while that of the patient with mild form remained unchanged. The shift of the pattern to the mild form correlated well with reduction of the sum of the serum lactate and pyruvate content during exercise. Noninvasive tissue oximetry may be useful to evaluate the effect of coenzyme Q10 supplementation to patients with mitochondrial encephalomyopathy including MELAS.

Adolescent↗
PubMed1999

The contributory role of interstitial water in Gd-DTPA-enhanced MRI in myocardial infarction.

We studied the mechanism underlying regional enhancement of myocardial infarction using T1-weighted MRI with gadolinium (Gd)-DTPA. Anterior myocardial infarction (MI) was produced by left anterior descending coronary artery ligation in three groups of rats as follows: 60 minutes occlusion (occlusion group, N = 6), 60 minutes occlusion plus 120 minutes reperfusion (reperfusion group, N = 8), and sham-operated (control, N = 6). In Gd-DTPA-enhanced MRI, MI was demarcated as a hypoenhanced region in the occlusion group and as a homogeneous hyperenhanced region in the reperfusion group. Both Gd-DTPA tissue concentration and tissue water content in the anterior wall were highest in the reperfusion group (P<0.05), a finding suggestive of microscopically observed interstitial edema. The data suggest that regional accumulation of Gd-DTPA in the reperfused group can be explained by increased interstitial water content, contributing to the delayed washout of the water-soluble contrast medium.

Animals↗
PubMed1999

Yersinia pseudotuberculosis blocks the phagosomal acidification of B10.A mouse macrophages through the inhibition of vacuolar H(+)-ATPase activity.

Yersinia pseudotuberculosis survived and multiplied in the phagosomes of B10.A mouse peritoneal macrophages. As one of the possible mechanisms for the bacteria's survival in the phagosomes, we demonstrated that live Y. pseudotuberculosis inhibited the phagosomal acidification; pH within phagosomes containing the live Y. pseudotuberculosis remained at about 6.0, whereas pH within phagosomes containing the dead Y. pseudotuberculosis fell to about 4. 5. This ability to inhibit intraphagosomal acidification was also shared by mutants lacking the 42 Md virulence plasmid, indicating that it is chromosomally encoded. The phagosomes containing dead bacteria raised the pH to 6.2 after the treatment of their macrophages with an inhibitor (bafilomycin A1) specific for V-ATPase. Although the amount of V-ATPase in the A and B subunits on the phagosomes was not significantly different between the live and dead bacteria infection, the phagosomes containing live bacteria had a 10-fold smaller V-ATPase activity than those containing the dead bacteria. These results indicated that the inhibition of phagosomal acidification by Y. pseudotuberculosis infection was due to the attenuation of V-ATPase activity, and not due to the exclusion of V-ATPase subunits from the phagosome membrane as found in Mycobacterium avium.

Animals↗
PubMed1999

Propofol does not affect the canine cardiac conduction system under autonomic blockade.

PURPOSE: To determine the effects of propofol on the cardiac conduction system in dogs with pharmacological autonomic blockade. METHODS: In eight mongrel dogs receiving 6 mg.kg-1.hr-1 propofol and vecuronium under pharmacological autonomic blockade with atropine and propranolol the infusion rates of propofol were increased from 6, (baseline), to 12, 18 and 24 mg.kg-1.hr-1 at 60-min intervals. An electrophysiological study assessed sinus rate, sinus node recovery time, corrected sinus node recovery time, intraatrial conduction time, AV nodal effective refractory period, Wenckebach cycle length and AV conduction times. Electrocardiographical variables and arterial pressures were also measured. All measurements were repeated at 30 min after the beginning of each infusion of propofol. RESULTS: Propofol did not produce direct effects on the electrophysiological or electrocardiographical variables at any infusion rates. Heart rates did not change at higher infusion rates in the presence of decreases in arterial pressures. CONCLUSION: Propofol did not affect the cardiac conduction system in the presence of autonomic blockade. Thus, the direct cardiac effects of propofol do not play a causative role in the genesis of propofol-associated bradyarrhythmias.

Anesthetics, Intravenous↗
PubMed1999

Augmented growth response to IGF-1 via increased IRS-1 in Chinese hamster ovary cells expressing kinase-negative insulin receptors.

AIMS/HYPOTHESIS: Although both increased cell growth and impaired insulin signalling have been associated with diabetes, this association has not been investigated. Insulin-like growth factor-1 (IGF-1), a structural and functional analog of insulin, may play a part in the aberrant insulin receptor-mediated signalling observed in diabetes. METHODS: To investigate the consequence of this impaired signalling on cell proliferation and transformation, we transfected Chinese hamster ovary cells with cDNA encoding a kinase-defective insulin receptor. RESULTS: In these mutant cells, the mitogenic and metabolic effects of insulin were reduced compared with control cells (p < 0.05) and this was due to a dominant negative effect. In contrast, these mutant cells showed a higher mitogenic response to IGF-1 than control cells, although IGF-1 receptor expression was similar in both cell lines. There was no statistically significant difference in mitogenic response, however, to platelet-derived growth factor, basic fibroblast growth factor and heparin-binding epidermal growth factor-like growth factor. Variables of the IGF-1 signalling pathway, including tyrosine phosphorylation of insulin receptor substrate-1 and activation of mitogen-activated protein kinase and phosphatidyl inositol 3 kinase, were also augmented in mutant cells. Insulin receptor substrate-1 message and protein abundance were higher in mutant than in control cells. Moreover, mutant cells had a higher mitogenic potential in low-serum-containing medium, suggesting that these cells have a transformed phenotype. CONCLUSION/INTERPRETATION: These findings suggest that an impaired insulin signalling may upregulate insulin receptor substrate-1 and that this, in turn, leads to increased IGF-1 signalling, a phenomenon that is possibly associated with increased cell growth in diabetes.

Adaptor Proteins, Signal Transducing↗
PubMed1999

Association study of parathyroid hormone gene polymorphism and bone mineral density in Japanese postmenopausal women.

Association of BST B1 restriction fragment length polymorphism (RFLP) of the parathyroid hormone (PTH) gene with bone mineral density (BMD) was examined in 383 healthy postmenopausal women in Japan who were unrelated. The RFLP was represented as B or b, the capital letter signifying the presence of and the small letter the absence of restriction site for BST B1. The frequency of each genotype-BB, Bb, and bb-was 82.5%, 16.7%, and 0.8%, respectively. When we statistically compared age, years after menopause, body height, and body weight between the BB genotype and the Bb genotype groups, there was no significant difference between the groups. However, the lumbar BMD and the score of BMD adjusted for age and body weight (Z score) were significantly lower in the group of genotype Bb than in the BB: 0.859 +/- 0.019 g/cm2 versus 0.925 +/- 0. 011 (mean +/- SE, P = 0.01) and -0.412 +/- 0.138 versus 0.067 +/- 0. 082 (mean +/- SE, P = 0.01). In addition, the Z score of total body BMD in the Bb genotype group was lower than that in the BB group. Comparison of serum and urinary biochemical bone metabolic markers suggested that the subjects with Bb genotype might be in a relatively higher state of bone turnover than those with BB genotype. These results suggest that the polymorphism in the PTH gene would be a useful genetic marker for lower BMD and the susceptibility for osteoporosis.

Absorptiometry, Photon↗
PubMed1999

The Palliative Prognostic Index: a scoring system for survival prediction of terminally ill cancer patients.

Although accurate prediction of survival is essential for palliative care, few clinical methods of determining how long a patient is likely to live have been established. To develop a validated scoring system for survival prediction, a retrospective cohort study was performed with a training-testing procedure on two independent series of terminally ill cancer patients. Performance status (PS) and clinical symptoms were assessed prospectively. In the training set (355 assessments on 150 patients) the Palliative Prognostic Index (PPI) was defined by PS, oral intake, edema, dyspnea at rest, and delirium. In the testing sample (233 assessments on 95 patients) the predictive values of this scoring system were examined. In the testing set, patients were classified into three groups: group A (PPI< or =2.0), group B (2.0 4.0). Group B survived significantly longer than group C, and group A survived significantly longer than either of the others. Also, when a PPI of more than 6 was adopted as a cut-off point, 3 weeks' survival was predicted with a sensitivity of 80% and a specificity of 85%. When a PPI of more than 4 was used as a cutoff point, 6 weeks' survival was predicted with a sensitivity of 80% and a specificity of 77%. In conclusion, whether patients live longer than 3 or 6 weeks can be acceptably predicted by PPI.

Aged↗
PubMed1999

Long-distance effects of site-directed mutations on backbone conformation in bacteriorhodopsin from solid state NMR of [1-13C]Val-labeled proteins.

We have recorded 13C cross-polarization-magic angle spinning and dipolar decoupled-magic angle spinning NMR spectra of [1-13C]Val-labeled wild-type bacteriorhodopsin (bR), and the V49A, V199A, T46V, T46V/V49A, D96N, and D85N mutants, in order to study conformational changes of the backbone caused by site-directed mutations along the extracellular surface and the cytoplasmic half channel. On the basis of spectral changes in the V49A and V199A mutants, and upon specific cleavage by chymotrypsin, we assigned the three well-resolved 13C signals observed at 172.93, 172.00, and 171. 11 ppm to [1-13C]Val 69, Val 49, and Val 199, respectively. The local conformations of the backbone at these residues are revealed by the conformation-dependent 13C chemical shifts. We find that at the ambient temperature of these measurements Val 69 is not in a beta-sheet, in spite of previous observations by electron microscopy and x-ray diffraction at cryogenic temperatures, but in a flexible turn structure that undergoes conformational fluctuation. Results with the T46V mutant suggest that there is a long-distance effect on backbone conformation between Thr 46 and Val 49. From the spectra of the D85N and E204Q mutants there also appears to be coupling between Val 49 and Asp 85 and between Asp 85 and Glu 204, respectively. In addition, the T2 measurement indicates conformational interaction between Asp 96 and extracellular surface. The protonation of Asp 85 in the photocycle therefore might induce changes in conformation or dynamics, or both, throughout the protein, from the extracellular surface to the side chain of Asp 96.

Bacteriorhodopsins↗
PubMed1999

Location of a cation-binding site in the loop between helices F and G of bacteriorhodopsin as studied by 13C NMR.

The high-affinity cation-binding sites of bacteriorhodopsin (bR) were examined by solid-state 13C NMR of samples labeled with [3-13C]Ala and [1-13C]Val. We found that the 13C NMR spectra of two kinds of blue membranes, deionized (pH 4) and acid blue at pH 1.2, were very similar and different from that of the native purple membrane. This suggested that when the surface pH is lowered, either by removal of cations or by lowering the bulk pH, substantial change is induced in the secondary structure of the protein. Partial replacement of the bound cations with Na+, Ca2+, or Mn2+ produced additional spectral changes in the 13C NMR spectra. The following conclusions were made. First, there are high-affinity cation-binding sites in both the extracellular and the cytoplasmic regions, presumably near the surface, and one of the preferred cation-binding sites is located at the loop between the helix F and G (F-G loop) near Ala196, consistent with the 3D structure of bR from x-ray diffraction and cryoelectron microscopy. Second, the bound cations undergo rather rapid exchange (with a lifetime shorter than 3 ms) among various types of cation-binding sites. As expected from the location of one of the binding sites, cation binding induced conformational alteration of the F-G interhelical loop.

Bacteriorhodopsins↗
PubMed1999

Running exercise increases tumor necrosis factor-alpha secreting from mesenteric fat in insulin-resistant rats.

Tumor necrosis factor-alpha (TNF-alpha) is an important mediator of insulin resistance in obese subjects, through its overexpression in fat tissue. However, how exercise can modify the expression of TNF-alpha is controversial. We examined TNF-alpha in adipose tissue using an animal model of insulin resistance that was produced by feeding rats a diet high in sucrose. The rats were allocated to one of three groups: those receiving a starch-based diet (control group): those fed a high-sucrose diet (sucrose-fed group): and those fed a high-sucrose diet and given wheel exercise (exercised group). The animals were allowed to eat and drink ad lib for 4 or 12 weeks (4 wk: control n=7, sucrose-fed n=7, exercised n=10; 12 wk: control n=5, sucrose-fed n=5, exercised n=9). The voluntary wheel exercise was initiated with the feeding of the high-sucrose diet. The rats in the exercise groups ran 15 +/- 3 km/week. We showed that 12-week voluntary running exercise significantly (P<0.05) increased both TNF-alpha protein (5-fold) and mRNA (1.4 fold) in the mesenteric fat of insulin-resistant rats compared to non-exercised sucrose-fed mice. Accordingly, in exercised group, plasma glucose (124 +/- 9 mEq/L vs 141 +/- 11 mEq/L). and free fatty acid (0.98 +/- 0.07 mEq/L vs 1.4 +/- 0.05 mEq/L) concentrating in portal vein blood were reduced compared to sucrose-fed group. The amounts of fatty tissue both in mesenteric and subcutaneous tissues were significantly (P<0.05) decreased through running exercise. We consider that up-regulation of TNF-alpha in mesenteric fat may be a compensatory mechanism for the reduction of fatty acid in adipose tissues and this change could control metabolic homeostasis during exercise to modulate a hyperinsulinemic state.

Adipose Tissue↗
PubMed1999

Reduced nitric oxide production by L-arginine deficiency in lysinuric protein intolerance exacerbates intravascular coagulation.

Lysinuric protein intolerance (LPI) results in low serum L-arginine, hyperammonemia, mental retardation, thrombocytopenia, and an increased frequency of bowel movements. Our objective was to evaluate the effects of low serum L-arginine, the essential substrate for reactions catalyzed by nitric oxide synthetase (NOS), on the serum nitric oxide (NO) level and coagulation activity in a patient with LPI. A 37-year-old Japanese man who presented with abdominal pain and subnormal fasting levels of serum L-arginine and L-lysine was found to have LPI. The result of oral administration of diamino acids was an increased in urine and a decrease in serum, thus confirming the diagnosis. A decrease in the platelet count and an increase in the plasma levels of thrombin-antithrombin III complex (TAT) and fibrin degradation products (FDPs) indicated the presence of subclinical intravascular coagulation. Serum levels of NO derivatives and L-arginine were determined after intravenous administration of L-arginine. The effects of intravenous L-arginine or transdermal nitroglycerin on the plasma level of TAT were also investigated. Serum levels of NO derivatives were significantly reduced in the LPI patient versus the healthy control group (n = 5). Intravenous administration of L-arginine increased the serum level of NO derivatives and the platelet count and reduced plasma TAT and FDP levels. The plasma level of TAT was also reduced by transdermal nitroglycerin. A decrease in the serum level of L-arginine in patients with LPI appears to result in a decrease in NO production. The improvement in plasma TAT levels produced by administration of intravenous L-arginine or transdermal nitroglycerin suggests that intravascular coagulation is exacerbated by the decrease of NO production in patients with LPI.

Adult↗
PubMed1999

Blomhotin: a novel peptide with smooth muscle contractile activity identified in the venom of Agkistrodon halys blomhoffii.

A novel peptide has been isolated from the venom of Agkistrodon halys blomhoffii using a bioassay that monitors the stimulant effect on rat stomach fundus. The 11-amino acid peptide, named blomhotin, was purified to homogeneity by gel-filtration column chromatography and reverse-phase HPLC. The amino acid sequence of blomhotin was determined to be pGlu-Gly-Arg-Pro-Pro-Gly-Pro-Pro-Ile-Pro-Arg, which is similar to that of bradykinin-potentiating peptides which themselves cause no contraction of smooth muscle. The contraction induced by blomhotin showed homologous desensitization, implicating the involvement of a blomhotin-specific site in the response.

Amino Acid Sequence↗
PubMed1999

Antimony in municipal waste.

Antimony content in municipal waste was studied. Sampled municipal waste was dried, crushed and analyzed. Antimony determinations were performed by Kjeldahl decomposition--batch hydride generation spectrometry and neutron activation analysis. Overall content of antimony in waste was 40-50 g/t raw waste. It was estimated than 20% of the annual production of antimony was discarded as municipal waste in Japan. Leaching of antimony from antimony-added materials may occur, because "small tips" involved considerable amounts of antimony.

Antimony↗