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Biomedical subjects

H Hirano

Publications and source records attributed to H Hirano.

At least 91 records · Page 5Linked to original sources

[Modularization by the open standard. (I)].

We are proceeding with the project called "Open LA21 Project" in the course of the clinical laboratory automation toward the 21st century. With the modular system that realizes integration, downsizing, a reasonable price, and is the future course in the clinical testing automation system as well, we aim to establish common standards among manufacturers as the only way to create user friendly market environments where the proper competition exists among the manufacturers. The common standards which are in preparation by the participating companies as "Open module system standards" are the standards which are going to be made public. They are intended to guarantee connection, compatibility of the products in conformity with the standards. In this project, we intend to realize the modular system that integrates each field, such as chemistry, hematology, coagulation/fibrinolysis, immunology, urinalysis in an early stage, and contribute positively to restructuring and upgrading the "raison d'etre" of the 21st century clinical testing.

Automation↗

H-Ras signals to cytoskeletal machinery in induction of integrin-mediated adhesion of T cells.

The adhesive function of integrins is regulated through cytoplasmic signaling. The present study was performed to investigate the relevance of cytoplasmic signaling and cytoskeletal assembly to integrin-mediated adhesion induced by chemokines. Adhesion of T cells induced by chemokines macrophage inflammatory protein (MIP)-1alpha and MIP-1beta was inhibited by pertussis toxin, wortmannin, and cytochalasin B, suggesting that both G protein-sensitive phosphatidylinositol (PI) 3-kinase activation and cytoskeletal assemblies are involved. The chemokine-induced T cell adhesion could be mimicked by expression of small G proteins, fully activated H-RasV12, or H-RasV12Y40C mutant, which selectively binds to PI 3-kinase, in T cells, inducing activated form of LFA-1alpha and LFA-1-dependent adhesion to ICAM-1. H-Ras expression also induced F-actin polymerization which colocalized with profilin in T cells. Adult T cell leukemia (ATL) cells spontaneously adhered to ICAM-1, which depended on endogenous MIP-1alpha and MIP-1beta through activation of G protein-sensitive PI 3-kinase. H-Ras signal pathway, leading to PI 3-kinase activation, also induced active configuration of LFA-1 and LFA-1-mediated adhesion of ATL cells, whereas expression of a dominant-negative H-Ras mutant failed to do. Profilin-dependent spontaneous polymerization of F-actin in ATL cells was reduced by PI 3-kinase inhibitors. In this paper we propose that H-Ras-mediated activation of PI 3-kinase can be involved in induction of LFA-1-dependent adhesion of T cells, which is relevant to chemokine-mediated signaling, and that profilin may form an important link between chemokine- and/or H-Ras-mediated signals and F-actin polymerization, which results in triggering of LFA-1 on T cells or leukemic T cells.

Actins↗

Role of MaxiK channels in vasoactive intestinal peptide-induced relaxation of rat mesenteric artery.

We investigated the functional relevance of large conductance voltage-dependent and Ca(2+)-sensitive K(+)(MaxiK) channels in vasoactive intestinal peptide (VIP)-induced relaxation of rat mesenteric artery. VIP, which is known to increase cAMP levels, produced a concentration-dependent relaxation in endothelium-denuded arteries. Iberiotoxin, a MaxiK channel blocker, greatly diminished the VIP-induced relaxation. In a similar manner, a significant portion of the relaxant response to dibutyryl-cAMP (DBcAMP), a membrane-permeable analog of cAMP, was inhibited by iberiotoxin. These results suggest that activation of MaxiK channels significantly contributes to the relaxant response of rat mesenteric artery to VIP, possibly via cAMP-mediated pathways.

Animals↗

The occurrence of polymorphism of mannose 6-phosphate/insulin-like growth factor 2 receptor gene in laboratory and wild rats.

Carcinogen-resistant inbred DRH rat strain was established from closed colony Donryu rats in the presence of 3'-methyl-4-dimethylaminoazobenzene (3'-Me-DAB). Despite using 3'-Me-DAB during the stage of selection, the DRH rats developed normally and did not show any spontaneous tumor at over 1 year of age. In the present study, we examined the polymorphism in mannose 6-phosphate/insulin-like growth factor 2 receptor (M6p/Igf2r) gene and found that the DRH rat showed CCC (Proline)-type polymorphism in exon 48 and the Donryu rat had GCC (Alanine) sequence. Since the DRH rat was developed from the Donryu rat, we examined whether this polymorphism in exon 48 of M6p/Igf2r gene was due to mutation that occurred at the stage of selection in the presence of 3'-Me-DAB, using several other laboratory and wild rats. We detected the presence of polymorphism at the same site of the M6p/Igf2r gene among these rats. It is likely that the polymorphism in exon 48 of the M6p/Igf2r gene is present broadly in rats since ancient times and not due to the mutation during the course of selection unless this site is a hot spot for chemical carcinogens.

Alanine↗

Injection of antisense oligos to nNOS into nucleus tractus solitarii increases blood pressure.

We investigated the cardiovascular effects of bilateral microinjection of antisense oligodeoxynucleotides (oligos) into the nucleus tractus solitarii (NTS) to neuronal nitric oxide synthase (nNOS) to suppress the expression of nNOS molecular biologically. In urethane-anesthetized, paralyzed Wistar-Kyoto rats, bilateral microinjection of nNOS antisense oligos (20 pmol in a 50nl volume) into the NTS produced a significant increase in mean arterial blood pressure at 30-60min after injection, compared with rats injected with nNOS sense or scrambled oligos. Immunohistochemical study demonstrated that nNOS immunoreactivity in the rat NTS was suppressed by nNOS antisense oligos. These results indicate that suppression of the nNOS gene using antisense in the NTS increases blood pressure.

Animals↗

Endothelium is involved in the vasorelaxation by an ATP-sensitive K+ channel opener, NIP-121.

Possible involvement of endothelium was examined in the vasorelaxation of rat aorta in response to NIP-121 ((+)-7,8-dihydro-6,6-dimethyl-7-hyroxy-8-(2-oxo-1-piperidinyl)-6H- pyrano[2,3-f]benz-2,1,3-oxadiazole), an ATP-sensitive K+ (K(ATP)) channel opener. The NIP-121-induced vasorelaxation was greater in endothelium-intact preparations than in endothelium-denuded ones. In the presence of glibenclamide, which inhibits K(ATP) channels, NIP-121-induced vasorelaxations were of a similar extent in both endothelium-intact and -denuded preparations. These findings suggest that the presence of endothelium plays a role in the vasorelaxation in response to K(ATP) channel openers.

Adenosine Triphosphate↗

Cloning of human telomerase catalytic subunit (hTERT) gene promoter and identification of proximal core promoter sequences essential for transcriptional activation in immortalized and cancer cells.

Telomerase activation is thought to be a critical step in cellular immortalization and carcinogenesis. Of the three major subunits comprising human telomerase, human telomerase catalytic subunit (hTERT) has been shown to be a rate-limiting determinant of the enzymatic activity of human telomerase. However, little is known concerning how expression of hTERT is regulated in human cells. To identify the regulatory elements controlling hTERT gene expression, approximately 3.5 kb of the 5'-flanking sequence of hTERT was cloned and characterized. The promoter of hTERT was GC rich and lacked both TATA and CAAT boxes. The CapSite Hunting method identified transcription start site 19 bp upstream of the first nucleotide of the published cDNA sequence. Transient expression assays revealed that transcription of hTERT was significantly activated in cancer cell lines but repressed in normal primary cells. Using the fibroblast lineage at various stages of transformation, we found that transcription occurred in strains that had overcome replicative senescence and expressed telomerase activity. Deletion analysis of hTERT promoter identified the 181-bp core promoter region upstream of the transcription start site. Gel shift analysis revealed two major factors binding to core promoter, an E box (CACGTG) binding factor and Sp1. Overexpression of c-Myc resulted in a significant increase in transcriptional activity of the core promoter. These findings suggest that hTERT expression is strictly regulated at the transcription machinery, and that the proximal core promoter containing an E box and Sp1 sites is required for transactivation of hTERT.

Base Sequence↗

Evidence for a contribution of store-operated Ca2+ channels to NO-mediated endothelium-dependent relaxation of guinea-pig aorta in response to a Ca2+ ionophore, A23187.

A23187 (6S-[6alpha,8beta,9beta,11alpha]-5-(methylamino) -2-[[3,9,11-trimethyl-8-[1-methyl-2-oxo-2-(1H-pyrrol-2-yl)ethyl]-1,7- dioxaspiro[5.5]undec-2-yl]methyl]-4-benzoxazolecarboxylic acid, calcimycin), an antibiotic Ca2+ ionophore, produces an endothelium-dependent vascular relaxation. In the present study, pharmacological features were functionally characterized of endothelium-dependent relaxant response of guinea-pig aorta to A23187, especially focusing on the possible Ca2+ source and Ca2+ mobilization mechanisms in endothelial cells responsible for the vasorelaxant response to the Ca2+ ionophore. A23187-induced endothelium-dependent relaxation was suppressed profoundly by N(G)-nitro-L-arginine (L-NNA; 3 x 10(-4) M) or calmidazolium (3 x 10(-5) M), suggesting that nitric oxide (NO) produced by the enhanced activation of Ca2+/calmodulin-dependent endothelial NO synthase (eNOS) is largely responsible for the relaxant response of this artery to A23187. In the Ca2+-free solution without EGTA, NO-mediated endothelium-dependent relaxation induced by A23187 was almost abolished, which suggests that Ca2+ entry from extracellular space into endothelial cells plays the key role in the A23187-induced functional vasorelaxation. On the other hand, SK&F96365 (1-[beta-[3-(4-methoxyphenyl)propoxy]-4-methoxyphenethyl]-1H-imidazole; 5 x 10(-5) M) and Ni2+ (3 x 10(-4) M), both of which inhibit capacitative Ca2+ influx through store-operated Ca2+ channels (SOCCs), attenuated significantly NO-mediated endothelium-dependent relaxation by A23187. Furthermore, A23187-induced endothelium-dependent relaxation was suppressed more strongly than endothelium-independent relaxation induced by SIN-1 (3-morpholino-sydnonimine), an NO donor, when aortic preparation was preconstricted with high KCl instead of agonistic stimulation (prostaglandin F2alpha). These findings suggest that NO-mediated endothelium-dependent relaxant response of guinea-pig aorta to A23187 is preceded by the increase in endothelial cytosolic free Ca2+ concentration ([Ca2+]cyt) due to the enhanced Ca2+ influx from extracellular space. In the enhanced Ca2+ entry leading to the stimulation of eNOS and NO-mediated functional relaxant response of guinea-pig aorta to A23187, activation of SOCCs but not the Ca2+ entry through plasma membrane Ca2+-specific routes made by A23187 seems to play the predominant role. It is most likely that A23187 acts primarily at the Ca2+ store sites in endothelial cells, which subsequently depletes stored Ca2+ to activate SOCCs via unidentified mechanisms.

Animals↗

Medial plantar nerve conduction velocities among patients with vibration syndrome due to chain-saw work.

OBJECTIVE: The present study examined the effect of the vibration syndrome (VS) on the peripheral nervous system in the lower extremities. METHODS: Thirty-eight patients with VS due to previous exposure to vibration from chain-saw work and 55 age-matched controls were examined for sensory nerve conduction velocities in the medial plantar nerve (SCV-P). The patient group was divided into two subgroups, one with (n=19) and the other without vibration-induced white finger (VWF; n=19). RESULTS: Analysis of variance of SCV-P for the three groups showed significant difference (F(2,89)=10.65, P < 0.0001). A significant difference was found between the controls and the VWF(+) group (P < 0.0001) but not between the controls and the VWF(-) group (P=0.0508) by multiple comparison using Scheffe's method. CONCLUSION: These findings suggest that VS affects the peripheral nervous system function in the lower extremities via mediation of circulatory disturbance manifested as VWF.

Action Potentials↗

Shifted cytosolic NADP+-dependent isocitrate dehydrogenase on 2-D gel in the brain of genetically epileptic E1 mice.

We observed a spot on two-dimensional (2-D) gel in the epileptic mutant strain E1 mice with a similar molecular weight but with a different isoelectric point of approximately 0.2, compared with its mother strain ddY mice. The collected protein from the E1 mice was identified as cytosolic NADP+-dependent isocitrate dehydrogenase by internal amino acid sequencing. The enzyme is known to be maximally active during the development of the brain and to play an important role in NADPH production for fatty acids and cholesterol synthesis. In addition, alterations in cholesterol synthesis early in the development of the mammalian brain have been reported to lead to chronic epilepsy. The results in the present study therefore suggest that cytosolic NADP+-dependent isocitrate dehydrogenase might be involved in the epileptogenesis of the E1 mouse.

Amino Acid Sequence↗

Primary structure and possible functions of a trypsin inhibitor of Bombyx mori.

A protein with a low molecular mass of 6027 was purified from cocoon shell of silkworm, Bombyx mori. Two-dimensional polyacrylamide gel electrophoresis (2D/PAGE) resolved this protein into a single spot with pI 4.3 and Mr 6000. Amino acid sequence analysis revealed that this protein consists of 55 amino acids, six of these being cysteine residues and is highly homologous to bovine pancreatic trypsin inhibitor-type inhibitors. The 6-kDa protein is heat stable and acid stable and inhibits bovine trypsin by forming a low-dissociation complex with trypsin in a 1 : 1 molar ratio (Ki = 2.8 x 10-10), but does not alpha-chymotrypsin. This cocoon shell-associated trypsin inhibitor (CSTI) was thus concluded to belong to the bovine pancreatic trypsin inhibitor class. CSTI was developmentally regulated in the silk gland at the final stage of larval growth, and its specific distribution in the middle silk gland, an organ in which silk proteins are stored during the final larval instar, occurred before the onset of spinning. This inhibitor protects the tryptic degradation of fibroin light (L) chain in vitro. These results suggest that this trypsin inhibitor may play an important part on regulating proteolytic activity in the silk gland or protecting silk proteins from degradation during histolysis.

Amino Acid Sequence↗

Renal adenomatosis associated with carcinoma of the lower urinary tract: a case report with immunohistochemical study.

A case of renal adenomatosis of the left kidney associated with a carcinoma of the ipsilateral ureter in a 49-year-old man is examined. One hundred and eight adenomas, which were smaller than 15 mm in diameter, and a single microcarcinoma, which measured 1 mm in diameter, were found in the kidney. Further, there were more than 800 hyperplastic lesions which could be classified into three groups: (i) 792 of distal origin; (ii) 24 of proximal origin; and 10 of collecting duct origin. The serial sections obtained from 19 paraffin blocks were stained using Leu M1 as the proximal marker and epithelial membrane antigen (EMA) as the distal/collecting marker to assist in determining the origins. Ten of the small adenomas (15 lesions), which did not exceed 3 mm in diameter, were predominantly positive for EMA and five were predominantly positive for Leu M1. Further, hyperplastic lesions of distal and collecting duct origins were diffusely positive for EMA and sporadically positive for Leu M1. The lesions of proximal origin were predominantly positive for Leu M1 and sporadically positive for EMA. These findings suggest that a progression from hyperplasia and a direct transition from a single tubule to adenoma occurred multifocally in different segments of the nephrons throughout the left kidney.

Adenoma↗

Subcellular localization of glucocorticoid receptor protein in the human kidney glomerulus.

BACKGROUND: The detailed mechanisms of glucocorticoid action in idiopathic nephrotic syndrome and progressive glomerulonephritides have not been clearly elucidated. The pharmacological actions of glucocorticoids are mediated by their binding to an intracellular protein, the glucocorticoid receptor (GR). The determination of GR localization in normal glomerular cells is essential to elucidate the mechanisms of glucocorticoid action in various glomerular diseases. METHODS: We carried out an immunoblot examination using antihuman GR-specific antibody and homogenates of isolated normal human glomeruli and mesangial cells in culture. Immunohistochemical examinations were also performed on normal human kidney specimens at light and electron microscopic levels. The nuclear translocation of GRs elicited by ligand binding was further investigated by confocal laser-scanning microscopic inspection of freshly isolated glomeruli and mesangial cells cultured with dexamethasone. RESULTS: An immunoblot examination demonstrated the presence of a 94 kDa protein, a molecular weight consistent with that of GRs, in the homogenates of glomeruli and cultured mesangial cells. By light microscopic examination, GRs were strongly detected in the nucleus and moderately in the cytoplasm of all glomerular cells, parietal and visceral epithelial cells, endothelial cells, and mesangial cells. By electron microscopic examination, the nuclear GRs of all glomerular cells were found to be diffusely distributed in the euchromatin. Additionally, the immunofluorescence intensities of nuclear GRs in isolated glomeruli and mesangial cells in culture became more intense by the addition of dexamethasone. CONCLUSIONS: Our findings suggest that all subsets of human glomerular cells definitely express the GR protein, which potentially undergoes translocation by glucocorticoids.

Cell Nucleus↗

Evaluation of serum lipid abnormalities in chronic nephritis.

BACKGROUND: In glomerular disease, disorders of lipid metabolism are suspected as factors exacerbating glomerular dysfunction. Although many reports have been published regarding metabolic disorders of lipids in renal disease, including nephrotic syndrome and chronic renal failure, there have been few published reports describing metabolic disorders of lipids in chronic nephritis. Therefore, in patients with IgA nephritis, we evaluated correlations between serum lipid levels and renal function and proteinuria. METHODS: In 191 patients with IgA nephritis, we evaluated the correlations between serum lipid levels and renal function [creatinine clearance (CCr)] and proteinuria (UP). Serum lipids examined included total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), apolipoproteins, phospholipids (PL), lipoprotein(a) [Lp(a)], and malondialdehyde (MDA). RESULTS: Significant correlations were observed between serum lipid levels and CCr, UP, and age. There were no abnormalities in the mean values of respective serum lipids examined. Although TC levels increased with age, HDL-C levels were not correlated with age. Hyperlipidemia was observed in 39.8% of subjects. Significant correlations were observed between levels of TC, TG, PL, LDL-C, apoB, apoC-II, and apoC-III and Ccr, UP, and age. Significant correlations were also observed between levels of MDA, apoB/apoA-I, apoE/apoC-III, and Ccr and age, as well as between apoE levels and UP and age. The levels of apoA-I and apoA-I/apoA-II ratio were significantly correlated with UP alone, whereas the apoC-II/apoC-III ratio was significantly correlated with Ccr alone. There were no significant correlations between levels of HDL-C, apoA-II, and Lp(a) and Ccr, UP, and age. CONCLUSIONS: Age, proteinuria, and renal function were related with changes in serum lipid levels in IgA nephritis. There were correlations between proteinuria and levels of apoA, as well as between renal function and apoC levels.

Adult↗

Comparison of MR imaging with CT in depiction of tumour extension into the pterygopalatine fossa.

The computed tomography (CT) and magnetic resonance imaging (MRI) results of 30 consecutive patients with tumours in the skull base, and who had abnormalities of the pterygopalatine fossa (PPF) on CT or MRI, were retrospectively compared with respect to visualization of tumour infiltration into the PPF. CT did not depict the abnormalities in the PPF in five patients (17%), while unenhanced T1-weighted MR images depicted tumour infiltration in all patients. Obliteration of PPF fat was better visualized on CT than T2-weighted and proton density weighted MR images, as were bony abnormalities. On MRI, intracranial extension was seen in eight of 25 patients with extracranial tumour. MRI is a sensitive method of demonstrating both tumour infiltration of the PPF and perineural tumour spread.

Adolescent↗

Effect of an aluminum hydroxide-magnesium hydroxide combination drug on adhesion, IL-8 inducibility, and expression of HSP60 by Helicobacter pylori.

BACKGROUND: Co-magaldrox (Maalox) is used world-wide as an antacid and as a cytoprotective agent for gastritis and peptic ulcer diseases. We examined the effects of co-magaldrox on Helicobacter pylori. METHODS: Adhesion of H. pylori to human gastric epithelial cells (MKN45) was evaluated by flow cytometry. Morphologic changes in H. pylori caused by co-magaldrox were determined by scanning electron microscopy. Induction of interleukin-8 (IL-8) from MKN45 cells was examined with enzyme-linked immunosorbent assay, and the intracellular and extracellular expression of heat-shock protein 60 (HSP60) was analyzed with sodium dodecyl sulphate-polyacrylamide gel electrophoresis and flow cytometry. RESULTS: Adhesion of H. pylori to MKN 45 cells was significantly inhibited by 1.25%-5% comagaldrox. H. pylori aggregated with co-magaldrox according to an electron microscopic examination. IL-8 secretion from MKN45 cells after H. pylori infection was also inhibited by co-magaldrox. Extracellular expression of HSP60 on the surface of H. pylori was decreased after treatment with comagaldrox, whereas the intracellular synthesis of HSP60 was not. HSP60-induced IL-8 secretion was significantly inhibited by co-magaldrox in a dose-dependent manner. CONCLUSIONS: These results show that co-magaldrox suppressed the expression of the following virulence factors: adhesion, IL-8 inducibility, and expression of extracellular HSP60. Therefore, co-magaldrox is a potent anti-H. pylori and cytoprotective drug.

Aluminum Hydroxide↗