Biomedical subjects

J Hirose

Publications and source records attributed to J Hirose.

At least 37 records · Page 2Linked to original sources

PubMed1998

Human neutrophil elastase degrades inter-alpha-trypsin inhibitor to liberate urinary trypsin inhibitor related proteins.

Urinary trypsin inhibitor (UTI) is a physiological protease inhibitor and inter-alpha-trypsin inhibitor (ITI) is regarded as a precursor of UTI. The purpose of this study is to determine the mechanism of the UTI release from ITI. To examine this, ITI was digested by human neutrophil elastase at various concentrations, and UTI-related proteins which were of the same size as UTI were obtained. The amino acid sequence of the 15 amino acid residues at the N-terminal of UTI-related proteins, corresponded to that of UTI. The amino acid sequences of the small amount of peptides detected corresponded to those of peptides from the heavy chain1 (H1) and the heavy chain2 (H2) of ITI, suggesting that most UTI-related proteins do not combine with peptides from the H1 and H2 of ITI. It was also revealed that UTI-related proteins have several physiological activities similar to those of UTI, i.e., human trypsin inhibitory activity, human neutrophil elastase inhibitory activity, inhibition of tumor necrosis factor-alpha (TNF-alpha) production from rat macrophages and of superoxide production from rabbit leukocytes. These results demonstrated that ITI is a precursor of UTI which is digested by human neutrophil elastase to release UTI, and that its elastase inhibitory activity is derived from UTI.

Alpha-Globulins↗

PubMed1998

Vascular and non-vascular ligands for L-selectin.

Ligands for L-selectin are expressed not only on vascular endothelial cells but also in the extravascular tissues. In this article, we summarize the current understanding of the "vascular" ligands for L-selectin. We also describe identification of "non-vascular" ligands for L-selectin and discuss their possible biological significance.

Animals↗

PubMed1997

The pH dependent properties of metallotransferrins: a comparative study.

The dependence on pH of the absorption and circular dichroic spectra of iron(III), cobalt(III) and copper(II) transferrins has been (re)investigated. In the alkaline region, the CD profiles of iron(III) and cobalt(III) transferrin are essentially pH independent up to pH 11; only for very high pH values (pH > 11) is breakdown of the cobalt(III) and iron(III) transferrin derivatives observed, without evidence of conformational rearrangements. By contrast, the CD profiles of copper transferrin show drastic changes in shape around pH 10; these spectral changes, which are fitted to a pKa of approximately 10.4, are interpreted in terms of a substantial rearrangement of the local environment of the copper ions at high pH. Although the CD spectra of copper transferrin at alkaline pH strictly resemble those observed upon addition of modifier anions, the mechanism of site destabilization in the two cases is different; at variance with the case of modifier anions, our results suggest that the high pH form of copper transferrin still contains the synergistic anion. A 13C NMR experiment has confirmed this view. In the acidic region, iron(III) and cobalt(III) transferrins are stable down to pH approximately 6. For lower pH values progressive metal detachment is observed without evidence of conformational changes; around pH 4.5 most bound metals are released. In the case of the less stable copper-transferrin, metal removal from the specific binding sites is already complete around pH 6.0; in concomitance with release from the primary sites, binding of copper ions to secondary sites is observed. Additional information has been gained from CD experiments in the far UV. The pH dependent properties of iron(III), cobalt(III) and copper(II) transferrin are discussed in the frame of the present knowledge of transferrin chemistry, particular emphasis being attributed to the comparison between tripositive and bipositive metal derivatives.

Cations, Divalent↗

PubMed1997

Reduced ischemia-reperfusion injury in muscle. Experiments in rats with EPC-K1, a new radical scavenger.

L-ascorbic acid 2-[3,4-dihydro-2,5,7,8-tetramethyl- 2-(4,8,12-trimethyltridecyl)-2H-1-benzopyran-6-yl hydrogen phosphate] potassium salt (EPC-K1), a phosphate diester of alpha-tocopherol and ascorbic acid, is a potent antioxidant. We examined the effects of EPC-K1 on ischemia-reperfusion injury in the skeletal muscle of rats, using an ischemic revascularized hind limb model. Warm ischemia (25 degrees C), produced by vascular pedicle clamping, was sustained for 4 hours. After 24 hours of reperfusion, skeletal muscle injury was evaluated in 2 groups: one group treated by intravenous injection of EPC-K1 (10 mg/kg) prior to ischemia, and a group of controls. The EPC-K1-treated group showed a statistically significant amelioration in the reduction of the isometric muscle contraction, inhibition of the elevation of the muscle wet- to dry-weight ratio, limitation of the muscle level of thiobarbituric acid reactive substances and the serum levels of creatine phosphokinase, lactate dehydrogenase and mitochondrial glutamic oxaloacetic transaminase, and reduction of the extent of muscle injury according to the histological findings. These observations indicate that EPC-K1 acted effectively on ischemia-reperfusion injury in the rat skeletal muscle and thereby improved muscle function.

Animals↗

PubMed1996

Copper binding selectivity of N- and C-sites in serum (human)- and ovo-transferrin.

Copper binding selectivity of the N- and C-sites in serum (human)- and ovo-transferrin was investigated through copper binding constants, copper dissociation rate constants, and EPR spectra. At pH 7.4, stepwise copper binding constants of serum (human)-transferrin were K1 = 1.8 (+/- 0.6) x 10(12) M-1 and K2 = 1.2 (+/- 0.5) x 10(11) M-1, and those of ovo-transferrin were K1 = 1.9 (+/- 0.5) x 10(11) M-1 and K2 = 2.1 (+/- 0.4) x 10(11) M-1. Absorbance changes resulting from copper binding to the C- or N-site at various ratios of Cu2+/apo-transferrin were separated by a kinetic method. It was clearly indicated that, in serum (human)-transferrin, the copper binding affinity for the C-site was much larger than that for the N-site, whereas in ovo-transferrin, the C- and N-sites have almost the same affinity for copper ions. In the presence of anions (0.1 M KCl or 0.1 M NaClO4), the stepwise copper binding constants of serum (human)-transferrin were almost 10-times smaller than those in the absence of the anions. The selectivity in binding the copper ions to both sites of serum (human)-transferrin in the presence of 0.1 M NaClO4 is much smaller than that in the presence of 0.1 M KCl or in the absence of the anions (0.1 M KCl and 0.1 M NaClO4). EPR spectra of the copper ions of the N-site in dicupric serum-transferrin are dramatically changed respectively by the addition of 0.1 M KCl, 0.1 M NaCl, and 0.1 M NaClO4. This suggests that the change in the coordination geometry of the copper ions occurs at the N-site.

Anions↗

PubMed1996

Cardioscopic spectrum of the left ventricular endocardial surface and its relation to histologic changes in idiopathic myocarditis.

To examine feasibility of percutaneous cardioscopy for diagnosis of idiopathic myocarditis, cardioscopic appearance of the left ventricle and biopsy findings were compared in 21 such patients. The endocardial surface was milky white, red, pink, or reddish brown and edematous at the segments that exhibited histologic changes of acute myocarditis; purplish red in those that exhibited chronic active myocarditis; and yellow in those that exhibited chronic inactive or healed myocarditis. Follow-up study by repeated cardioscopy and biopsy in six patients revealed that the milky white surface disappeared and that the red, pink, and reddish brown surfaces changed to purplish red and then to yellow or white. The results indicate that the endocardial coloration of the left ventricle represents histologic changes and that cardioscopy is feasible for macroscopic pathologic diagnosis and for follow-up of idiopathic myocarditis.

Acute Disease↗

PubMed1996

Improvement of insulin sensitivity and dyslipidemia with a new alpha-glucosidase inhibitor, voglibose, in nondiabetic hyperinsulinemic subjects.

This study was undertaken to investigate the effect of voglibose, a new alpha-glucosidase inhibitor, on glucose and lipid metabolism in nondiabetic hyperinsulinemic subjects. Sixteen nondiabetic subjects with hyperinsulinemia participated in the study. They were divided into two groups of eight subjects with normal (NGT) and impaired (IGT) glucose tolerance. A meal tolerance test and a 75-g oral glucose tolerance test (OGTT) were performed at the beginning (baseline phase) and end (treatment phase) of the 12-week treatment. Serum lipid levels were measured every 4 weeks throughout the treatment phase and follow-up phase (8 weeks). All patients received 1 0.2-mg tablet of voglibose before each test meal (3 tablets per day). We also measured insulin sensitivity using a steady-state plasma glucose (SSPG) method in eight normotensive hyperinsulinemic subjects and in eight age- and body mass index (BMI)-matched control subjects before and after the drug treatment. Voglibose significantly decreased the responses of plasma glucose and insulin on the meal tolerance test. The area under the curve for 2-hour insulin during the 75-g OGTT decreased after treatment, whereas that for 2-hour glucose did not change before and after treatment. SSPG was reduced after treatment, indicating improvement of insulin sensitivity. Moreover, treatment with voglibose resulted in a significant decline of triglyceride level and an elevation of high-density lipoprotein (HDL) cholesterol and apolipoprotein A-1. These values returned to near-baseline levels after the drug was discontinued. Consequently, we conclude that this agent not only has a direct hypoglycemic effect through decreased absorption of carbohydrate, but also a hypoinsulinemic and hypolipidemic effect via improved insulin sensitivity.

Blood Glucose↗

PubMed1996

Characterization of monoclonal antibodies against (1R,2R)-cyclohexanediamine platinum(II)-DNA adduct.

Two monoclonal antibodies raised against Pt(II)(1R,2R-cyclohexanediamine)-DNA were prepared, and the specificity of the monoclonal antibodies against Pt(II)(cyclohexanediamine)-DNA derivatives was determined by competitive enzyme-linked immunosorbent assay. The binding affinity of the monoclonal antibodies is apparently influenced by the cyclohexanediamine moiety of Pt(II)(cyclohexanediamine)-DNA adducts, but the monoclonal antibodies can not bind to the low molecular analogue, Pt(II)(1R,2R-cyclohexanediamine)-d(GpG), which is the intrastrand binding model compound of Pt(II)(1R,2R-cyclohexanediamine)-DNA. Therefore, the monoclonal antibodies recognize the macromolecular parts, including DNA duplex, in addition to the cyclohexane moieties of the platinum complexes on Pt(II)(cyclohexanediamine)-DNA adducts.

Antibodies, Monoclonal↗

PubMed1996

Novel beta-D-galactofuranose-containing high-mannose type oligosaccharides in ascorbate oxidase from Acremonium sp. HI-25.

Ascorbate oxidase from the fungus Acremonium sp. HI-25 is a copper-containing glycoprotein that catalyzes the oxidation of ascorbic acid to dehydroascorbic acid. Monosaccharide composition analysis showed that the enzyme contains exclusively N-linked oligosaccharide chains. Following liberation by hydrazinolysis/re-N-acetylation, and fractionation by HPLC on anion exchange. Amide-80 and/or octadecyl silica columns after derivatization with p-aminobenzoic ethyl ester, the structures of the twelve major neutral oligosaccharides were identified by FAB-MS, 400 MHz 1H-NMR, methylation analysis, mild acid hydrolysis, and/or sequential exoglycosidase digestions. Acremonium sp. ascorbate oxidase was found to consist of high-mannose type oligosaccharides (76.3%) having 4 to 9 mannose residues and a series of novel D-galactofuranose-containing high-mannose type oligosaccharides (18.6%) with the following structure.

Acremonium↗

PubMed1996

Modified method using a somatostatin analogue, octreotide acetate (Sandostatin) to assess in vivo insulin sensitivity.

In order to evaluate the steady state plasma glucose (SSPG) method by using a new somatostatin derivative, octreotide acetate (Sandostatin) instead of somatostatin that we had used for the insulin sensitivity test, we examined whether octreotide was able to suppress C-peptide (CPR), glucagon (IRG), and GH to a similar degree to that achieved with somatostatin. A total of 52 studies were performed in 45 essential hypertensive subjects and 7 healthy subjects. Octreotide was given subcutaneously in a does of 50 micrograms or 100 micrograms 10 min before the test (sc 50, sc 100 groups) or intravenously infused over 2 h (10 micrograms in bolus followed by a constant infusion, 50, 100, or 150 micrograms/2 h: i.v. 50, i.v. 100, i.v. 150 groups). In all of the groups the plasma immunoreactive insulin (IRI) concentration increased gradually after insulin injection and reached the steady state plasma insulin (SSPI) level between 40 and 60 microU/ml at 60 min through 120 min. Plasma CPR at 120 min was the most suppressed (by 67% of the basal level in i.v. 150 group during the study period), but on the other hand in both the sc 100 and i.v. 100 groups the plasma CPR concentration at 120 min was suppressed by nearly 40%, but not significantly suppressed in either the sc 50 or the i.v. 50 group. Plasma IRG and GH were strongly suppressed after 60 min in all groups during the study period. Plasma glucose had increased significantly at 30 min and reached the steady state at 90 min through 120 min in hypertensive and healthy subjects. The results indicated that the modified SSPG method with continuous intravenous infusion of Octreotide at 150 micrograms/2 h was adequate for the measurement of insulin sensitivity.

Blood Glucose↗

PubMed1995

Angioscopic detection of residual pulmonary thrombi in the differential diagnosis of pulmonary embolism.

Definite diagnosis of pulmonary embolism (PE) by conventional methods such as angiography is frequently difficult. If residual thromboemboli incorporated into the pulmonary arterial wall or in the distal small segments are visible, differential diagnosis of PE versus primary pulmonary hypertension (PPH) can be made without open-chest pulmonary biopsy. Six patients suspected of having acute PE, 6 suspected of having chronic PE, and 4 with PPH diagnosed by pulmonary biopsy underwent percutaneous pulmonary angioscopy. In patients suspected of having PE, globular and mural thromboemboli were detected by both angioscopy and angiography in 4 and 1 patients, respectively. By angioscopy, emboli incorporated into the arterial wall were detected in 7 and microemboli obstructing the distal small segments were detected in 6. However, these emboli were detected by angiography in none. In patients with PPH, no embolus was detected by angioscopy and angiography. Angioscopically, however, stenoses were observed in the distal small segments in all patients. The results indicate that residual pulmonary thromboemboli in PE and stenoses of distal pulmonary arteries in PPH are detectable by percutaneous angioscopy, and therefore this method is feasible for differential diagnosis of PE.

Acute Disease↗

PubMed1995

Prediction of acute coronary syndromes by percutaneous coronary angioscopy in patients with stable angina.

To pinpoint the link between plaque characteristics and acute coronary syndromes, we performed a 12-month prospective follow-up study in 157 patients with stable angina pectoris in whom regular coronary plaques were observed by percutaneous coronary angioscopy. Acute coronary syndromes occurred more frequently in patients with yellow plaque than in those with white plaques (11 of 39 vs 4 of 118; p = 0.00021). Moreover, the syndromes occurred more frequently in patients with glistening yellow plaques than in those with nonglistening yellow plaques (9 of 13 vs 2 of 26; p = 0.00026). Thrombus arising from the ruptured identical plaques was confirmed by angioscopy as the culprit lesion of the syndromes. The results indicate that acute coronary syndromes occur frequently and in a short time in patients with glistening yellow plaques and that angioscopy but not angiography is feasible for prediction of the syndromes.

Acute Disease↗

PubMed1995

Improvement of insulin sensitivity for glucose metabolism with the long-acting Ca-channel blocker amlodipine in essential hypertensive subjects.

To clarify whether the long-acting calcium-channel blocker amlodipine restores insulin insensitivity in essential hypertension, insulin sensitivity tests were performed at the physiological steady-state insulin level (45 to 55 microU/mL) before and after amlodipine (2.5 to 7.5 mg/d) administration for 2 to 4 months in borderline and mild essential hypertensive subjects. Instead of somatostatin, Sandostatin (Sandoz, Basel, Switzerland) was used for the determination of steady-state plasma glucose (SSPG) in the same way as previously described. SSPG, which was initially high (212.9 +/- 18.0 mg/dL, mean +/- SE), was significantly reduced to 169.8 +/- 14.7 after amlodipine treatment. Responses of ketone bodies during the test at 30 minutes, which reflect the insulin effect on lipolysis in adipose tissue and hepatic fatty acid oxidation, also improved after amlodipine treatment. Norepinephrine, noted to be mildly elevated after amlodipine treatment, decreased during the sensitivity test at 2 hours probably due to the sedative effect, without any change in the fractional extraction of Na. This indicates that the physiological level of insulin does not activate sympathetic nerve activity or stimulate Na reabsorption. The long-acting calcium-channel blocker amlodipine has significantly improved the initially decreased insulin sensitivity for glucose metabolism at least partially in borderline or mild essential hypertension.

Amlodipine↗

PubMed1994

Functional and structural relationship of various extradiol aromatic ring-cleavage dioxygenases of Pseudomonas origin.

The extradiol ring-cleavage dioxygenases derived from seven different Pseudomonas strains were expressed in Escherichia coli and the substrate specificities were investigated for a variety of catecholic compounds. The substrate range of four 2,3-dihydroxybiphenyl dioxygenases from biphenyl-utilizing bacteria, 3-methylcatechol dioxygenase from toluene utilizing Pseudomonas putida F1, 1,2-dihydroxynaphthalene dioxygenase from a NAH7 plasmid, and catechol 2,3-dioxygenase from a TOL plasmid pWW0 were compared. Among the dioxygenases, that from Pseudomonas pseudoalcaligenes KF707 showed a very narrow substrate range. Contrary to this, the dioxygenase from pWW0 showed a relaxed substrate range. The seven extradiol dioxygenases from the various Pseudomonas strains are highly diversified in terms of substrate specificity.

Biodegradation, Environmental↗

PubMed1994

Novel factor Xa and plasma kallikrein inhibitory-activities of the second Kunitz-type inhibitory domain of urinary trypsin inhibitor.

Urinary trypsin inhibitor is a glycoprotein with a structure in which two Kunitz-type inhibitory domains are linked in a row. We isolated two genes encoding the 70 amino acid sequence from the 78th amino acid (Thr) to the C-terminal and the 68 amino acid sequence from the 80th (Ala) to the C-terminal of human urinary trypsin inhibitor, both which correspond to the second Kunitz-type inhibitory domain, and then constructed expression plasmids by ligating it to the E. coli alkaline phosphatase signal peptide gene. These plasmids under the control of the tryptophan promoter expressed the second domain in E. coli strain JE5505 which lacks the membrane lipoprotein. The recombinant second domain purified from the culture supernatant of the transformant inhibited trypsin, plasmin, leukocyte elastase and chymotrypsin which are known to be inhibited by urinary trypsin inhibitor. In addition it inhibited blood coagulation factor Xa and plasma kallikrein in a concentration dependent and competitive manner, and significantly prolonged the plasma-based activated partial thromboplastin time (APTT). The truncated natural counterpart obtained by a limited degradation of human urinary trypsin inhibitor also revealed the identical inhibitory activities.

Amino Acid Sequence↗

PubMed1994

Construction of hybrid biphenyl (bph) and toluene (tod) genes for functional analysis of aromatic ring dioxygenases.

Multicomponent enzyme complexes of biphenyl (BP) dioxygenase (Dox) encoded by the gene cluster, bphA1A2A3A4 in Pseudomonas pseudoalcaligenes strain KF707 [Taira et al., J. Biol. Chem. 267 (1992) 4844-4858] and toluene Dox encoded by the gene cluster, todC1C2BA in P. putida strain F1 [Zylstra et al., J. Biol. Chem. 264 (1989) 14940-14946], show high homologies (approx. 60%) for the corresponding subunit component in spite of the fact that they have discrete substrate specificities. We constructed hybrid gene clusters by replacing the gene component(s) between the large and small subunits of terminal Dox in the bph and tod gene clusters, and analyzed the function of a novel hybrid aromatic ring Dox. Escherichia coli cells expressing the hybrid gene clusters, todC1::bphA2A3A4, todC1C2::bphA3A4 and bphA1::todC2::bphA3A4, gained the ability to convert benzene-toluene and their derivatives to the dihydrodiols, indicating that the hybrid terminal Dox composed of TodC1::BphA2 and BphA1::TodC2 forms a functionally active multicomponent Dox associated with ferredoxin (Fer) (BphA3) and Fer reductase (BphA4). Moreover, hybrid Dox (composed of TodC1::BphA2A3A4 and TodC1C2::BphA3A4) showed a wide substrate specificity rather similar to that of the wild-type toluene Dox (TodC1C2BA). On the other hand, the hybrid Dox (BphA1::TodC2::BphA3A4) showed oxidative activities for the same compounds, but the rate of oxidation was dependent upon the substrate. These results suggest that (i) the two subunits of terminal Dox are critically involved in the substrate specificity for BP, benzene and their derivatives, and (ii) the electron transport proteins, Fer and Fer reductase, are exchangeable with one another between the BP Dox and toluene Dox complexes.

Base Sequence↗

PubMed1994

Protective effect of recombinant neutrophil elastase inhibitor (R-020) on sepsis-induced organ injury in rat.

Severe inflammatory responses after major surgeries, trauma, and infection develop multiple organ dysfunction. In the mechanisms of the pathogenesis of these responses, activated neutrophils are thought to be important in terms of their ability to produce various kinds of proteinases, which can degrade various proteins constructing human tissues. Among their proteinases, neutrophil elastase is the strongest serine proteinase secreted from activated neutrophils. Thus, we examined in this study the inhibitory effect and therapeutic efficacy of newly produced recombinant human Kunitz-type proteinase inhibitor (R-020), which coded the second domain of human urinary trypsin inhibitor. R-020 was effective in significantly improving the survival rate after induction of the rat lethal peritonitis model (cecal ligation and puncture-induced septic shock model). We suggest that various serine proteinases are implicated in the pathogenesis of neutrophil-related multiple organ failure and that recombinant human Kunitz-type proteinase inhibitor might be effective in the treatment of these kinds of organ dysfunction.

Amino Acid Sequence↗

PubMed1994

Characterization of ascorbate oxidase from Acremonium sp. HI-25.

The ascorbate oxidase obtained from a microorganism, Acremonium sp. HI-25 (molecular weight, 80 kDa; monomeric protein), was studied with respect to atomic absorption, EPR, absorption spectra, circular dichroism (CD) spectra, and steady-state kinetics. The enzyme was found to be a multicopper protein, containing four copper atoms of three kinds, types 1, 2, and 3 copper, in the ratio of 1:1:2. The EPR parameters of the type 1 and 2 copper atoms in the ascorbate oxidase are very similar to those in the case of the ascorbate oxidase obtained from cucumber, which is a dimeric protein. The apparent Km and kcat values for ascorbic acid of the ascorbate oxidase from Acremonium sp. HI-25 are almost the same as those of the monomeric unit of the ascorbate oxidase from cucumber.

Acremonium↗