Biomedical subjects

S Hirose

Publications and source records attributed to S Hirose.

At least 487 records · Page 27Linked to original sources

PubMed1990

[Postgastrectomy megaloblastic anemia--possible participation of anti-intrinsic factor antibody in its pathogenesis--report of a case].

A case of 78-year old man with megaloblastic anemia occurring 20 years after partial gastrectomy is reported. Since about 2 years earlier he had an episode of convulsion, and he had been on anti-convulsants (diphenylhydantion, phenobarbital) until admission. Physical examination revealed a pale lean man with polyneuropathy and mental impairment. Laboratory findings revealed WBC 3100/microliters, RBC 187 X 10(4)/microliters, HB 7.9 g/dl, MCV 124.4 microns3, MCH 42.7 micrograms, platelet counts 15.7 X 10(4)/microliters, serum vitamin B12 (VB12) 380 pg/ml, and serum folic acid 5.1 ng/ml. Serum autoantibodies to intrinsic factor (IF) and parietal cells were positive. Bone marrow examination revealed erythroid hyperplasia and megaloblastic changes. Schilling test revealed impaired absorption of VB12 with or without IF, but X-ray study of the small bowels was unremarkable. Treatment with intramuscular cyanocobalamin resulted in a rapid clinical improvement. A repeat Schilling test after 4 months of therapy showed a normal VB12 absorption in the presence of IF. These findings suggest that VB12 malabsorption of the 1st Schilling test was due to intestinal dysfunction caused by the VB12 deficiency state itself, and the improvement of VB12 absorption with IF after therapy suggests a pathogenesis similar to pernicious anemia in this patient.

Aged↗

PubMed1990

[Immunological analysis of Streptococcus sanguis antigens].

The exact cause of Behçet's disease is still unknown. Recently, advanced bacterial studies revealed that Behçet's disease was related to Streptococcus (S.) sanguis. However, the antigenicity of S. sanguis has not been fully studied. In this study, we clarified the antigenicity of S. sanguis. We made S. sanguis antigens: Mechanical Braun Extract (MBE) and Crude Cell Wall (CCW) from the whole cells, Membrane Fraction (MF) and Cytoplasmic Fraction (CF) from MBE, Cell Wall Fragment (CWF) and Lipoteichoic acid (LTA) from MBE. We found that the major antigenicity of S. sanguis was present in CF by use of the Ouchterlony method and the ELISA method. However, apart from S. pyogenes, we could not recognize a common antigenicity among S. sanguis and several other antigens, such as S-Ag, IRBP, retinal soluble fraction, retinal insoluble fraction and Enterococcus faecalis, by the Ouchterlony method. Since we have clarified the antigenicity of S. sanguis in this study, we can now perform detailed examinations with samples from patients with Behçet's disease for S. sanguis antigens.

Animals↗

PubMed1989

Evidence that C4b-binding protein is an acute phase protein.

C4b-binding protein is a regulatory factor for both complement and coagulation systems. We found that a human hepatoma cell line, Hep G2, was capable of synthesizing C4b-binding protein and that the secretion of C4b-binding protein was enhanced by interleukin-6 and tumor necrosis factor, which are known to be modulators of acute phase proteins. In addition, the plasma content of C4b-binding protein was found to increase in patients of acute pneumonia. These results suggest that C4b-binding protein is an acute phase protein.

Acute-Phase Proteins↗

PubMed1989

Retinol-induced morphological changes of cultured bovine endothelial cells are accompanied by a marked increase in transglutaminase.

Retinol, a morphogen, has been shown to induce morphological changes in vascular endothelial cells, accompanied by an acute and specific accumulation of an 80-kDa protein; purification and characterization of this retinol-induced protein (RIP) have revealed that it is a transglutaminase. Endothelial cells from bovine carotid artery were cultured, treated with retinol, and examined for changes in morphology and protein profiles. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of extracts prepared from retinol-treated cells which had undergone a remarkable change in shape (from a cobblestone-like to a spindle-like shape) indicated that the retinol-induced morphological change is accompanied by a marked increase of an 80-kDa protein. Similar changes were also induced by retinoic acid. The 80-kDa RIP was purified by anion exchange and hydroxyapatite column chromatography. Amino acid sequencing of tryptic fragments of the purified RIP revealed a high degree of homology between the sequence of bovine RIP and that of guinea pig liver transglutaminase, suggesting that RIP is a transglutaminase. This was confirmed by activity measurements; RIP exhibited transglutaminase activity, and an antiserum against RIP immunoprecipitated the activity. These results suggest that transglutaminase plays important roles in the maintenance of morphology and the control of endothelial cell functions.

Amino Acid Sequence↗

PubMed1989

Purification and characterization of angiotensin-binding protein from porcine liver cytosolic fraction.

A protein that binds angiotensins with high affinity was found in porcine liver cytosol, purified to apparent homogeneity and characterized. The protein was named soluble angiotensin-binding protein (sABP) to distinguish it from angiotensin II receptors present on plasma membranes. Purification of the protein was achieved by a combination of ammonium sulfate fractionation, hydrophobic chromatography, ion-exchange chromatography, hydroxylapatite column chromatography and Mono Q ion-exchange chromatography. Specific angiotensin-binding activity, as measured using 125I-angiotensin II, was enriched more than 3400-fold. SDS/polyacrylamide gel electrophoresis of the purified sABP yielded a single 75-kDa protein band, in good agreement with the molecular mass estimated by affinity labeling. sABP was very similar to the angiotensin II receptor in its sensitivity to reducing agents and in its affinities for angiotensin analogues ([Sar1, Ala8]angiotensin II greater than angiotensin III greater than angiotensin II greater than angiotensin I), suggesting a possible similarity between the ligand-binding sites of sABP and the angiotensin II receptor. To obtain a clue to its physiological role(s), we examined the tissue distribution of sABP and found that this protein is widely distributed not only in the peripheral organs but also in the brain.

Affinity Labels↗

PubMed1989

Purification and properties of active atrial-natriuretic-peptide receptor (type C) from bovine lung.

Atrial-natriuretic-peptide (ANP) receptor, previously identified as a 140 kDa protein with a disulphide-linked homodimeric structure, was purified from bovine lung by (NH4)2SO4 fractionation and affinity chromatography on ANP-Affi-Gel 10. The purified receptor had a binding capacity of 4.2 nmol of ANP/mg of protein and an affinity constant of 6.5 pM. The isoelectric point of the receptor was 5.8, consistent with the acidic nature of the protein (amino acid analysis revealed a predominance of glutamic acid and aspartic acid residues). Treatment with endoglycosidase H and glycopeptidase F revealed that the receptor has three complex types of oligosaccharide chains per 70 kDa subunit. Deglycosylation of the receptor did not affect its binding activity. Reduction with dithiothreitol and reoxidation by dialysis revealed a strong tendency of the receptor subunits to dimerize via disulphide cross-linking; however, carboxymethylation of the reduced receptor indicated that the intersubunit disulphide bond is not necessary for the ligand-binding activity.

Amino Acid Sequence↗

PubMed1989

Bioluminescent assay for serum adenosine deaminase with immobilized bacterial luciferase.

We describe a bioluminescence method for measuring adenosine deaminase activity in serum. The method involves use of batchwise enzyme reaction containing adenosine, alpha-ketoglutarate, glutamic dehydrogenase and NADH. The resulting solution is injected to the continuous-flow bioluminescence system. In the system, a bacterial luciferase and NAD(P)H:FMN oxidoreductase are covalently co-immobilized on Sepharose 4B. Carrier solution (pH 6.8) for bioluminescence reaction contains FMN and decanal. The continuous-flow light-emitting system, in which the reactor (flow cell packed with immobilized enzyme) is placed in front of a photomultiplier tube inside a photon counter, is versatile and simple. Concentration and response are linearly related from 1.2 to 92.5 pmol per injection of ammonia. The precision of the method is satisfactory (coefficient of variation 3.9-6.8%). We validated the technique by comparing results with conventional assay method (UV method). Normal values for adenosine deaminase activity of serum ranged from 7.0 to 22.0 U/l in agreement with those obtained by other method. The Sepharose 4B-immobilized enzymes are stable for more than one year. This assay system could be used as a routine clinical laboratory test in the diagnosis of liver damage.

Adenosine↗

PubMed1989

An Epstein-Barr virus-transformed B cell line produces autoregulatory interleukin-1 that regulates bone remodeling.

In this study, we demonstrate that an Epstein-Barr virus-transformed B cell line, A-11, produced interleukin-1 (IL-1), a cytokine that regulates bone remodeling. A-11 cells produce IL-1 in a cell dose- and culture time-related manner. The IL-1 activity was neutralized by recombinant human IL-1 (rhIL-1) alpha antiserum, but not by rhIL-1 beta antiserum. The IL-1 was semi-purified by (NH4)2SO4 precipitation, Superose prep 12 gel filtration, and anion-exchange chromatography strongly stimulated in vitro bone resorption. The stimulatory effect of the purified IL-1 on bone resorption was prostaglandin independent. Purified IL-1 inhibited DNA and collagen synthesis in the osteoblastic cell line MC3T3-E1. However, it enhanced significantly the cellular activity of alkaline phosphatase (EC 3.1.3.1), a marker enzyme for differentiation of osteoblasts. On the other hand, A-11 cell proliferation was inhibited by addition of rhIL-1 alpha antiserum, but not by rhIL-1 beta antiserum. And cell proliferation was stimulated by exogenous rhIL-1 alpha and -beta.

Alkaline Phosphatase↗

PubMed1989

Effect of DNA supercoiling on in vitro transcription from the adenovirus early region 4.

The effect of DNA supercoiling on in vitro transcription from the early region 4 (E4) promoter of adenovirus type 5 (Ad5) has been investigated by using a cell-free transcription system that maintains supercoiled DNA templates. The supercoiled DNAs yield several-fold higher levels of E4 transcripts and more faithfully reflect the regulation of in vivo transcription than the linear DNAs.

Adenoviridae↗

PubMed1989

Determination of the aminoglycoside antibiotics sisomicin and netilmicin in dried blood spots on filter discs, by high-performance liquid chromatography with pre-column derivatization and fluorimetric detection.

A simple method for the determination of the aminoglycoside antibiotic sisomicin or its 1-N-ethyl derivative, netilmicin in whole blood, using dried blood spots (DBSs) on filter-paper punched discs has been developed. Sisomicin or netilmicin in the DBSs were recovered most effectively in 0.5 M Na2HPO4 using ultrasonication. The eluates from the DBSs were treated by ultrafiltration for deproteinization and subjected to pre-column fluorescent derivatization using o-phthalaldehyde and beta-mercaptopropionic acid in 0.05 M KH2PO4-borate buffer (pH 9.0), followed by determination by reversed-phase high-performance liquid chromatography. The detection limits of sisomicin and netilmicin in the DBSs on punched discs (10.1 microliters of whole blood) were 0.053 and 0.50 micrograms per ml of whole blood, respectively (signal-to-noise ratio greater than or equal to 2). The method permits a simple collection of blood at the microlitre level and should prove particularly useful for monitoring sisomicin and netilmicin in blood at therapeutic levels in geriatric and paediatric patients.

Chemical Phenomena↗

PubMed1989

An improved method for the detection of IgE antibody of defined specificity by ELISA using rat monoclonal anti-IgE antibody.

An improved method for the detection of IgE antibody of defined specificity by ELISA using rat monoclonal anti-IgE antibodies is described. The innovation consists of coating the plates first by a monoclonal rat anti-murine IgE antibody, adding the sera to this antibody-coated plates and then adding the biotin-conjugated antigen after the sera. The plates are then reacted with streptavidin-peroxidase and developed. This procedure eliminates possible competitions with other isotypes of the same specificity. The method is useful especially to quantitate IgE with defined specificity in the presence of high amounts of isotypes of the same specificity.

Animals↗

PubMed1989

Stimulation of Na-K-Cl cotransport in cultured vascular endothelial cells by atrial natriuretic peptide.

Vascular endothelial cells have been shown to contain atrial natriuretic peptide (ANP)-sensitive Na-K-Cl cotransport system whose activity is regulated by intracellular cGMP levels. Addition of ANP to culture medium stimulated 86Rb+ uptake in bovine endothelial cells with a concomitant increase in cGMP contents. This action of ANP was mimicked by 8-bromo-cGMP and completely diminished by furosemide. These results indicate that ANP selectively activates the Na-K-Cl cotransporter in vascular endothelial cells via cGMP and offer new insight into the physiological significance of endothelial ANP receptors.

Animals↗

PubMed1989

Endothelin induces two types of contractions of rat uterus: phasic contractions by way of voltage-dependent calcium channels and developing contractions through a second type of calcium channels.

Effects of endothelin on nonvascular smooth muscle have been examined using rat uterine horns and two modes of endothelin action have been revealed. Endothelin (0.3 nM) caused rhythmic contractions of isolated uterus in the presence of extracellular calcium. The rhythmic contractions were completely inhibited by calcium channel antagonists. These characteristics of endothelin-induced contractions were very similar to those induced by oxytocin. Binding assays using 125I-endothelin showed that endothelin and the calcium channel blockers did not compete for the binding sites. However, endothelin was unique in that it caused, in addition to rhythmic contractions, a slowly developing monophasic contraction that was insensitive to calcium channel blockers. This developing contraction became dominant at higher concentrations of endothelin and was also calcium dependent.

Animals↗

PubMed1989

Mechanism of activation of particulate guanylate cyclase by atrial natriuretic peptide as deduced from radiation inactivation analysis.

The interaction between the receptor (Rc) for atrial natriuretic peptide (ANP) and the effector enzyme particulate guanylate cyclase (GC) has been studied by radiation inactivation. Irradiation of bovine lung membranes produced an increase in GC activity at low radiation doses followed by a dose-dependent reduction at higher doses. This deviation from linearity in the inactivation curve disappeared when lung membranes were pretreated with ANP. Essentially identical results were also obtained with adrenal membranes. Based on these radiation inactivation data, the following dissociative mechanism of activation of particulate guanylate cyclase by ANP has been proposed: Rc.GC(inactive) + ANP----Rc.ANP + GC(active).

Adrenal Glands↗

PubMed1989

Inhibition of atrial natriuretic peptide-induced cyclic GMP accumulation in the bovine endothelial cells with anti-atrial natriuretic peptide receptor antiserum.

Using an antiserum raised against the purified atrial natriuretic peptide (ANP) receptor that has a disulfide-linked homodimeric structure and represents one subtype of the multiple ANP receptors, we showed that the receptor is coupled to the guanylate cyclase activation; formerly, this type of ANP receptor is not considered to be coupled to the cyclase. The specificity of the antiserum was determined by immunoblot analysis and immunoprecipitation. The anti-receptor antiserum did not compete with 125I-ANP for binding to the receptor but it lowered the affinity of the receptor. When added to bovine endothelial cell cultures, the antiserum blocked the cyclic GMP response of the cells triggered by ANP. These results indicate that the subtype of the ANP receptor recognized by the antiserum is responsible for the activation of particulate guanylate cyclase as well as the double function type receptor that has been assumed to contain both the receptor domain and the catalytic domain for cGMP synthesis on the same molecule. The presence of dissociative complexes of ANP receptor and particulate guanylate cyclase was also demonstrated by radiation inactivation analysis.

Animals↗

PubMed1989

Purification and characterization of Ki antigen and detection of anti-Ki antibody by enzyme-linked immunosorbent assay in patients with systemic lupus erythematosus.

Ki antigen from rabbit thymus extract was purified by ammonium sulfate precipitation, anti-Ki affinity chromatography, and high pressure liquid chromatography gel filtration. The purified Ki antigen gave a single polypeptide with an MW of 32,000 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and it specifically reacted with anti-Ki antibody by immunoblotting. The isoelectric point of the Ki antigen was found by isoelectric focusing to be 4.3. An enzyme-linked immunosorbent assay using the purified Ki antigen was established, and the clinical significance of the anti-Ki antibody in systemic lupus erythematosus (SLE) was studied. Thirty of 140 patients with SLE (21.4%) had anti-Ki antibody by enzyme-linked immunosorbent assay, whereas 11 (7.9%) were positive by double immunodiffusion. Analysis of clinical and serologic data on patients with SLE suggested a higher prevalence of central nervous system involvement in patients with anti-Ki antibody.

Antibodies↗

PubMed1989

Scirrhous carcinoma of the stomach: a clinical and pathological study of 106 surgical cases.

Clinical and pathological characteristics of scirrhous carcinoma of the stomach were studied in 106 cases treated by gastrectomy between 1973 and 1983. The male to female ratio was 0.58. The percentage of scirrhous carcinomas to all gastric carcinomas resected in the same period was three times higher in females than males. The age distribution of the patients suggested that there were two peaks in the forties and sixties in the male, and in the thirties and fifties in the female. The incidence of scirrhous carcinoma in all types of gastric carcinoma was significantly higher in the twenties, thirties and forties compared to the lowest incidence in the seventies. In the female group the primary lesion had a tendency to be adjacent to the fundic gland area and to avoid intestinal metaplasia. In the male the opposite was recognized. Cancer nests with single cells or only several cells were common in this type of carcinoma. These findings suggest that there might be two biologically different scirrhous carcinomas both in the male and the female, the appearance of single carcinoma cells might be favored by female sex hormones and young ages, and not only the original gastric mucosa but also mucosa with intestinal metaplasia could be precursors of single carcinoma cells.

Adenocarcinoma, Scirrhous↗

PubMed1989

Two distinct monoclonal natural thymocytotoxic autoantibodies from New Zealand black mouse.

Autoimmune-prone NZB and NZB x NZW F1 mice have a large amount of autoantibodies cytotoxic for thymocytes (natural thymocytotoxic autoantibodies, NTA). We established two distinct monoclonal NTAs (NTA260 and NTA204) from a NZB mouse that react with the majority, but not all of these thymocytes. Flow cytometry analysis showed that NTA260 is positive on subpopulations of peripheral T cells from young mice, in which approximately 65% of CD4+ and 85% of CD8+ T cells were NTA260+. NTA260 also reacted with brain tissues of mice and rats, including Purkinje cells in the cerebellum. Western blot analysis showed that the molecular weight of NTA260 antigen was 55 kDa. In contrast to NTA260, NTA204 reacted with peripheral B cells but not with peripheral T cells in mice. NTA204 also reacted with peripheral blood granulocytes and bone marrow myeloid cells from both mice and rats. An immunofluorescence inhibition assay revealed the presence of autoantibodies with specificities of each NTA260 and NTA204 in the sera from NZB mice. As a selective decline in the subset of NTA260+ T cells but not NTA204+ B cells was observed with aging of NZB and NZB x NZW F1 hybrid mice, NTA260 is at least partly related to the observed immunological abnormalities of T cells in these autoimmune-prone New Zealand mice.

Age Factors↗