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Taniguchi A, Nakai Y, Fukushima M, Kawamura H, Imura H, Nagata I, Tokuyama K. Pathogenic factors responsible for glucose intolerance in patients with NIDDM. Diabetes 1992; 41:1540-6. [PMID: 1446794 DOI: 10.2337/diab.41.12.1540] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
To define the pathogenic factors responsible for glucose intolerance in NIDDM, we estimated insulin secretory capacity, SI, and SG in 11 healthy, nondiabetic subjects and 9 NIDDM patients who had no SI impairment. All subjects studied were nonobese and normotensive. Each underwent a 75-g OGTT and a modified FSIGT: glucose was administered (300 mg/kg body weight), and insulin was infused (20 mU/kg over 5 min) from 20 to 25 min after the administration of glucose. SI and SG were estimated by Bergman's minimal-model method. The insulin response to oral glucose was significantly lower in NIDDM patients than in normal control subjects. First-phase insulin secretion expressed as the integrated area of plasma insulin above the basal level during the first 20 min was much smaller in NIDDM subjects (214 +/- 112 pM.min) than in control subjects (4643 +/- 885 pM.min, P < 0.01). SI was not statistically different in normal control subjects (1.27 +/- 0.18 x 10(-4) min-1.pM-1) versus diabetic patients (1.62 +/- 0.33 x 10(-4) min-1.pM-1). However, SG was significantly lower in diabetic subjects (1.11 +/- 0.17 x 10(-2) min-1) than in control subjects (2.35 +/- 0.26 x 10(-2) min-1, P < 0.01). These results suggest that impaired insulin secretion and decreased SG are the factors responsible for glucose intolerance of Japanese NIDDM patients with normal insulin sensitivity. Because SI and SG are the factors responsible for glucose intolerance of NIDDM patients with insulin resistance, it is conceivable that decreased SG is common in NIDDM patients regardless of their SI index.
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Ogawa Y, Nakao K, Itoh H, Suga S, Imura H. [Molecular biology of the natriuretic peptide system]. NIHON RINSHO. JAPANESE JOURNAL OF CLINICAL MEDICINE 1992; 50:2885-92. [PMID: 1491445] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The natriuretic peptide system is composed of at least three distinct endogenous peptides: atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP) and C-type natriuretic peptide (CNP), and three receptors: ANP-A receptor/GC-A, ANP-B receptor/GC-B and the clearance receptor. This system influences the control of body fluid and blood pressure as cardiac hormones and local regulators. Recent advances in molecular biology have unravel the molecular mechanism of the natriuretic peptide system and have facilitated our understanding of it. The present review gives the current knowledge of the molecular biology of the natriuretic peptide system.
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128
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Shizuta Y, Kawamoto T, Mitsuuchi Y, Toda K, Miyahara K, Ichikawa Y, Imura H, Ulick S. Molecular genetic studies on the biosynthesis of aldosterone in humans. J Steroid Biochem Mol Biol 1992; 43:981-7. [PMID: 22217843 DOI: 10.1016/0960-0760(92)90326-e] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Corticosterone methyl oxidase Type I (CMO I) and II (CMO II) have been postulated to be the enzymes involved in the final two steps of aldosterone biosynthesis in humans. We have isolated human cDNAs for P450c11 and P450c18 as well as the corresponding genes, CYP11B1 and CYP11B2. Both protein products of these two genes as expressed in COS-7 cells exhibit steroid 11β-hydroxylase activity, but only P450c18, a product of CYP11B2, carried steroid 18-hydroxylase activity to form aldosterone. These results indicate that CYP11B2 encodes CMO, the actual catalytic function of which is retained by P450c18, a multifunctional enzyme. This conclusion is further supported by the finding that the P450c18 gene, CYP11B2, is mutated at several different loci in patients deficient in CMO I or II.
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129
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Okamoto Y, Ishida H, Taminato T, Tsuji K, Kurose T, Tsuura Y, Kato S, Imura H, Seino Y. Role of cytosolic Ca2+ in impaired sensitivity to glucose of rat pancreatic islets exposed to high glucose in vitro. Diabetes 1992; 41:1555-61. [PMID: 1446796 DOI: 10.2337/diab.41.12.1555] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Sustained exposure to high concentrations of glucose selectively impairs the ability of pancreatic islets to secrete insulin in acute glucose stimulation. In order to evaluate the interrelationship between impaired insulin secretion and the dynamics of the cytosolic free Ca2+ level ([Ca2+]i), we have investigated the effect of high glucose exposure on both [Ca2+]i dynamics in single rat beta-cells and insulin release from rat pancreatic islets. Islets cultured at a high glucose concentration (16.7 mM) for 24 h showed significant reductions of the 16.7 mM GSIR compared with islets cultured at a normal glucose concentration (5.5 mM) (3.38 +/- 0.24 vs. 4.26 +/- 0.34%, respectively, P < 0.05). The capacity of glucose to raise the [Ca2+]i level also was significantly reduced in the beta-cells maintained for 24 h at 16.7 mM glucose (P < 0.001). An additional culture in the medium with 5.5 mM glucose for 16 h restored both the GSIR and the [Ca2+]i response of islets cultured at high glucose. On the other hand, insulin release and [Ca2+]i rise in response to 20 mM L-Arg were well preserved. These observations confirm that exposure of pancreatic beta-cells to high glucose concentrations induces a selective reduction of the GSIR and, further, shows that this impaired response is reversibly restored by an additional culture with normal glucose. We also suggest that the inability of glucose to provoke a [Ca2+]i rise, which is observed in the beta-cells exposed to high glucose, may be responsible for the selective impairment of the GSIR.
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130
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Mano M, Sugawara A, Nara Y, Nakao K, Horie R, Endo J, Imura H, Yamori Y. Potassium accelerates urinary sodium excretion during salt loading without stimulating atrial natriuretic polypeptide secretion. Clin Exp Pharmacol Physiol 1992; 19:795-801. [PMID: 1473294 DOI: 10.1111/j.1440-1681.1992.tb00417.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
1. Effects of potassium (K) supplementation (100 mEq/day) on urinary sodium (Na) excretion and on the secretion of atrial natriuretic polypeptide (ANP) during salt loading (350 mEq/day) were studied in 12 healthy salt-resistant normotensives under strictly controlled metabolic ward conditions. 2. Urinary volume and Na excretion on the first day of the high salt period (HSP) were significantly greater in the K-supplemented group (KG) than in the control group (CG). 3. There was a significant gain in bodyweight after salt loading in both groups, with a significantly greater gain in CG on the second day of HSP. Haematocrit decreased significantly during salt loading in both groups, the degree of which was significantly greater in CG. 4. Plasma norepinephrine decreased significantly during salt loading in both groups, the degree of which was significantly less in KG than in CG. A significant increase in plasma ANP was observed in CG on and after the second day of HSP, while a significant increase in plasma ANP was observed on the fifth day of HSP in KG. 5. These findings indicate that K supplementation accelerates diuresis and natriuresis, resulting in moderate suppression of volume expansion induced by salt loading and that this accelerated diuresis and natriuresis is not a result of the action of ANP.
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Higashi J, Kumagai S, Hatanaka M, Imura H. The presence of antibodies to purified p24gag protein of HTLV-I in sera of patients with systemic lupus erythematosus (SLE). Virus Genes 1992; 6:357-64. [PMID: 1475908 DOI: 10.1007/bf01703084] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Sera of patients with systemic lupus erythematosus (SLE) were tested for their reactivity to HTLV-I by western blotting (WB). Seven (18%) of 40 SLE serum samples reacted to the p24gag protein of HTLV-I by WB using purified gag antigens. The specificity of anti-p24gag antibodies in the SLE sera was confirmed by competitive inhibition on WB. Two of the seven patients were shown to be HTLV-I carriers, because HTLV-I infected T cell lines were easily established from their peripheral blood mononuclear cells (PBMC). Except for these two carrier patients, the gag proteins were not detected in the lysates of PBMC by WB using anti-p24gag and anti-p19gag monoclonal antibodies. The gag and pX genes of HTLV-I were not detected by PCR in PBMC of the SLE patients, with the exception of the 2 HTLV-I carrier patients. These results show no direct involvement of HTLV-I in the etiology of SLE. However, the existence of a specific antibody to p24gag in the sera of some of the noncarrier SLE patients suggests a crossreactivity to either unknown viruses or some autoantigens.
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Murakami M, Kumagai S, Sugita M, Iwai K, Imura H. In vitro induction of IgG anti-DNA antibody from high density B cells of systemic lupus erythematosus patients by an HLA DR-restricted T cell clone. Clin Exp Immunol 1992; 90:245-50. [PMID: 1424281 PMCID: PMC1554619 DOI: 10.1111/j.1365-2249.1992.tb07936.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
An HLA-DR restricted T cell clone (26G11) which recognized a lymphoid cell-derived autoantigen associated with DR4 molecule was shown to induce not only autologous but also allogenic DR4+ B cells to produce large amounts of antibodies of the IgG and IgM classes. Using the helper activity of this clone, we investigated the mechanism of anti-DNA antibody production in DR-matched patients with systemic lupus erythematosus (SLE). When cultured with 26G11 cells, B cells from DR-matched normal control subjects produced large amounts of IgM anti-DNA antibody, but did not produce IgG anti-DNA antibody which is thought to have a pathological role in SLE. In contrast, B cells from DR-matched patients with active SLE spontaneously produced a fairly large amount of IgG anti-DNA antibody, and the production was augmented by the T cell clone. Little IgG anti-DNA antibody was produced by the B cells of patients with inactive SLE in either the presence or absence of T cell clone. We next fractionated B cells into low density B (LD-B) and high density B (HD-B) cells by centrifugation on discontinuous Percoll density gradients. IgG anti-DNA antibody was spontaneously produced by LD-B cells of active SLE patients but not by those either of inactive SLE patients or normal controls. On the other hand, although IgG anti-DNA antibody was not spontaneously produced by the HD-B cells of both active and inactive SLE patients, it could easily be induced by their culture with the T cell clone. Our results clearly show the existence of IgG anti-DNA antibody-producing B cells in the peripheral blood of SLE patients irrespective of their disease activity and suggest that autoreactive T cells may play a pathogenic role in SLE through the induction of autoantibody production.
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133
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Kurose T, Tsuda K, Ishida H, Tsuji K, Okamoto Y, Tsuura Y, Kato S, Usami M, Imura H, Seino Y. Glucagon, insulin and somatostatin secretion in response to sympathetic neural activation in streptozotocin-induced diabetic rats. A study with the isolated perfused rat pancreas in vitro. Diabetologia 1992; 35:1035-41. [PMID: 1361917 DOI: 10.1007/bf02221678] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Changes in glucagon, insulin and somatostatin secretion induced by electrical splanchnic nerve stimulation were examined in rats treated with streptozotocin as neonates and as adults. In order to study the direct neural effects we used the isolated perfused rat pancreas with intact left splanchnic nerve in vitro. In normal rats splanchnic nerve stimulation causes significant decreases in insulin (30-40%) and somatostatin (30-50%) secretion at both 16.7 mmol/l and 1 mmol/l glucose concentrations. In the neonatal streptozotocin-diabetic rat splanchnic nerve stimulation at 16.7 mmol/l glucose decreased insulin secretion (14%) further than in the control rats (30%), however, somatostatin secretion did not decrease to the same extent. Similar results were also observed at the low (1 mmol/l) glucose concentration. On the other hand, percent decreases of insulin and somatostatin secretion induced by splanchnic nerve stimulation in the streptozocin-diabetic rats were similar to the values observed in the normal control rats. The glucagon secretion in response to splanchnic nerve stimulation at 16.7 mmol/l glucose from pancreatic Alpha cells in both types of induced diabetes is exaggerated, and the degree of exaggeration seems to parallel the severity of the hyperglycaemia. However, the splanchnic nerve stimulation-induced glucagon secretion at 1 mmol/l glucose was impaired in the streptozotocin-diabetic rats, but not in the neonatal streptozotocin-diabetic rats. These data suggest that the sensitivity of diabetic Alpha and Delta cells to sympathetic neural activation are blunted, whereas the sensitivity of Beta cells is enhanced in the diabetic animal model.
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MESH Headings
- Animals
- Animals, Newborn/growth & development
- Animals, Newborn/metabolism
- Animals, Newborn/physiology
- Blood Glucose/drug effects
- Blood Glucose/metabolism
- Body Weight/drug effects
- Diabetes Mellitus, Experimental/metabolism
- Diabetes Mellitus, Experimental/physiopathology
- Diabetes Mellitus, Type 1/metabolism
- Diabetes Mellitus, Type 1/physiopathology
- Diabetes Mellitus, Type 2/metabolism
- Diabetes Mellitus, Type 2/physiopathology
- Disease Models, Animal
- Electric Stimulation
- Glucagon/metabolism
- In Vitro Techniques
- Insulin/metabolism
- Insulin Secretion
- Islets of Langerhans/innervation
- Islets of Langerhans/metabolism
- Islets of Langerhans/physiopathology
- Male
- Neurons/physiology
- Perfusion
- Rats
- Rats, Wistar
- Somatostatin/metabolism
- Splanchnic Nerves
- Streptozocin
- Sympathetic Nervous System/metabolism
- Sympathetic Nervous System/physiopathology
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134
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Yoshimasa T, Nakao K, Suga S, Kishimoto I, Kiso Y, Imura H. Identification and endothelin-induced activation of multiple extracellular signal-regulated kinases in aortic smooth muscle cells. FEBS Lett 1992; 311:195-8. [PMID: 1383037 DOI: 10.1016/0014-5793(92)81100-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
In order to explore intracellular signaling pathways of the mitogenic action of endothelin (ET), we examined the effect of ET on activities of extracellular signal-regulated kinases (ERKs) in rat aortic smooth muscle cells (SMCs). Treatment of rat aortic SMCs with ET-1 increased kinase activities toward myelin basic protein (MBP). Both 43- and 41-kDa proteins were activated when kinase assays were done in MBP-containing polyacrylamide gels after SDS-PAGE. These proteins were identified as ERK1 and ERK2 with immunoprecipitation and immunoblotting using antipeptide antibodies, respectively. These results indicate that ERKs mediate signal transduction by ET.
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135
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Tanaka K, Shimatsu A, Imura H. Iodothyronine 5-deiodinase in rat posterior pituitary. Biochem Biophys Res Commun 1992; 188:272-7. [PMID: 1417847 DOI: 10.1016/0006-291x(92)92380-g] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
We first describe the presence of iodothyronine 5-deiodinase (5D) in the neural lobe of rat pituitary. 6-n-Propyl-2-thiouracil (PTU), a specific inhibitor of type-I deiodinase, had no effect, showing that 5D in neurohypophysis is of type-III isozyme, which is specific for 5-deiodination and has been found only in the brain, placenta and skin. The presence of 5D (type-III) together with our previous report of 5'-deiodinase (type-I in euthyroidism and type-II in hypothyroidism) shows that the isozymes of deiodinases in the neurohypophysis are quite similar to those in the brain. These data suggest a previously unrecognized role of thyroid hormone in posterior pituitary physiology.
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136
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Suzuki A, Takahashi T, Nakamura K, Tsuyuoka R, Okuno Y, Enomoto T, Fukumoto M, Imura H. Thrombocytosis in patients with tumors producing colony-stimulating factor. Blood 1992; 80:2052-9. [PMID: 1382717] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
We investigated the cause of thrombocytosis in 14 patients with tumors producing colony-stimulating factor (CSF). Of the 14 patients, 10 had tumors producing granulocyte-CSF (G-CSF) and 4 had tumors producing granulocyte-macrophage--CSF (GM-CSF). Thrombocytosis of greater than 400 x 10(9)/L was noted in 8 of 10 patients with G-CSF-producing tumors and all 4 patients with GM-CSF-producing tumors. Median peak platelet counts were, respectively, 511 x 10(9)/L (range, 384 to 694 x 10(9)/L) and 579 x 10(9)/L (range, 526 to 910 x 10(9)/L) in patients with tumors producing G-CSF and GM-CSF. In most patients, thrombocytosis declined towards the terminal stage. High interleukin-1 (IL-1) and IL-6 levels were found in addition to CSFs in the plasma or culture supernatants of tumor cells obtained from most patients. In patients with GM-CSF-producing tumors, these specimens had megakaryocyte-CSF (Meg-CSF) activity, which was abolished by anti-GM-CSF antibody. These specimens also had megakaryocyte potentiating (Meg-Pot) activity attributable to both GM-CSF and IL-6. In patients with G-CSF-producing tumors, only Meg-Pot activity due to IL-6 was detected. These results indicate that the thrombocytosis in GM-CSF-producing tumors was caused by both the Meg-CSF activity of GM-CSF and the Meg-Pot activity of IL-6 plus GM-CSF, while that in G-CSF-producing tumors was due to the Meg-Pot activity of IL-6.
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137
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Than S, Ishida H, Inaba M, Fukuba Y, Seino Y, Adachi M, Imura H, Ikehara S. Bone marrow transplantation as a strategy for treatment of non-insulin-dependent diabetes mellitus in KK-Ay mice. J Exp Med 1992; 176:1233-8. [PMID: 1402665 PMCID: PMC2119408 DOI: 10.1084/jem.176.4.1233] [Citation(s) in RCA: 55] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The effects of allogeneic bone marrow transplantation (BMT) on non-insulin-dependent diabetes mellitus (NIDDM) were examined using KK-Ay mice. KK-Ay mice reconstituted with KK-Ay bone marrow cells showed glycosuria, hyperinsulinemia, and hyperlipidemia. However, KK-Ay mice (H-2b) that had been lethally irradiated (9.0 Gy) and then reconstituted with T cell-depleted bone marrow cells from normal BALB/c mice (H-2d) showed negative urine sugar with decreases in serum insulin and lipid levels 4 mo after BMT. Morphological recovery of islets and glomeruli was also noted after allogeneic BMT. These findings suggest that BMT can be used to treat not only a certain type of NIDDM but also its complications such as hyperlipidemia and diabetic nephropathy.
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138
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Nakao K, Ogawa Y, Suga S, Imura H. Molecular biology and biochemistry of the natriuretic peptide system. II: Natriuretic peptide receptors. J Hypertens 1992; 10:1111-4. [PMID: 1334991 DOI: 10.1097/00004872-199210000-00002] [Citation(s) in RCA: 143] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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139
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Hosoda K, Nakao K, Tamura N, Arai H, Ogawa Y, Suga S, Nakanishi S, Imura H. Organization, structure, chromosomal assignment, and expression of the gene encoding the human endothelin-A receptor. J Biol Chem 1992; 267:18797-804. [PMID: 1326535] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
We have isolated and characterized the gene for the human endothelin-A receptor. Southern blot analyses demonstrated a single copy gene for the receptor. The gene spans more than 40 kilobases and contains eight exons and seven introns. Intron 1 exists in the 5'-noncoding region, and introns 2-7 occur in the coding region. The locations of introns 2-7 exist before or after the regions encoding the membrane-spanning domains. The transcription start site, determined by primer extension experiments, is 502 base pairs upstream of the methionine initiation codon. The 5'-flanking region lacks a typical TATA box but contains a potential SP-1-binding site 27 base pairs upstream of the transcription start site. Using human-rodent somatic hybrid cell DNA, the gene was assigned to human chromosome 4. Northern blot analyses revealed a 4.3-kilobase mRNA in a wide variety of human tissues, at the highest level in the aorta and at a substantial level in the cultured human mesangial cells. This is the first report of cloning of a gene for a member of the endothelin receptor family. The present study should give a clue to the discovery of possible disorders of the endothelin-A receptor, as well as facilitate the elucidation of the mechanisms by which the gene expression is regulated.
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140
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141
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Suga S, Nakao K, Itoh H, Komatsu Y, Ogawa Y, Hama N, Imura H. Endothelial production of C-type natriuretic peptide and its marked augmentation by transforming growth factor-beta. Possible existence of "vascular natriuretic peptide system". J Clin Invest 1992; 90:1145-9. [PMID: 1522222 PMCID: PMC329977 DOI: 10.1172/jci115933] [Citation(s) in RCA: 419] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
C-type natriuretic peptide (CNP), the third member of the natriuretic peptide family, is thus far known to be distributed mainly in the central nervous system and is considered to act as a neuropeptide, in contrast to atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP), which act as cardiac hormones. Recently, we and others have demonstrated that the ANP-B receptor, which is selectively activated by CNP, is localized not only in the central nervous system but in peripheral tissues, including blood vessels. This finding has made us speculate regarding the peripheral production of CNP. In the present study, cultured endothelial cells were examined for CNP production by RIA and Northern blot analysis. CNP-like immunoreactivity was detected in the conditioned media of endothelial cells. Northern blot analysis detected CNPmRNA with a size of 1.2 kb. In addition, transforming growth factor (TGF)-beta, one of the key growth factors for vascular remodeling, markedly stimulated the expression of CNPmRNA and induced a tremendous increase in CNP secretion. We could also detect CNP transcript in the bovine thoracic aorta using the reverse transcription-polymerase chain reaction method. The present study demonstrates the endothelial production of CNP and suggests that a member of the natriuretic peptide family may act as a local regulator in vascular walls. Since evidence for the pathophysiological importance of the vascular renin-angiotensin system has been accumulating and the natriuretic peptide system is known to be antagonistic to the renin-angiotensin system, the possible existence of "vascular natriuretic peptide system" may prove to be of physiological and clinical relevance.
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142
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Jougasaki M, Kugiyama K, Saito Y, Nakao K, Imura H, Yasue H. Suppression of endothelin-1 secretion by lysophosphatidylcholine in oxidized low density lipoprotein in cultured vascular endothelial cells. Circ Res 1992; 71:614-9. [PMID: 1499109 DOI: 10.1161/01.res.71.3.614] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Oxidatively modified low density lipoprotein (oxidized LDL), an atherogenic lipoprotein that exists in the atherosclerotic arteries, has been shown to alter endothelial cell functions. In the present study, we examined the effects of oxidized LDL on the production of endothelin-1-like immunoreactivity (ET-1-LI) by the cultured vascular endothelial cells from porcine aorta and human umbilical vein. Incubation with oxidized LDL resulted in a dose-dependent suppression of ET-1-LI release by both endothelial cells. Oxidized LDL also inhibited thrombin-mediated stimulation of ET-1-LI secretion. However, native LDL had no effects on ET-1-LI secretion. A lipid extract from oxidized LDL, but not from native LDL, inhibited ET-1-LI secretion, indicating that the lipid component of oxidized LDL was required for the inhibition of ET-1-LI secretion. Oxidative modification of LDL was associated with degradation of a substantial amount of phosphatidylcholine to lysophosphatidylcholine (LPC). Pretreatment with defatted albumin, which is an acceptor for hydrophilic lipids including LPC, reduced LPC concentration in oxidized LDL to that in native LDL and simultaneously prevented the inhibitory effects of oxidized LDL on ET-1-LI secretion. Incubation with synthetic LPC (palmitoyl), but not with synthetic phosphatidylcholine (dipalmitoyl), suppressed ET-1-LI secretion by the endothelial cells. No cell death was observed during the incubations as judged by the trypan blue exclusion test, and protein synthesis of the endothelial cells was not affected by lipids or lipoproteins at a concentration at which suppression of ET-1-LI was observed. We concluded that LPC in oxidized LDL causes suppression of ET-1-LI release, which may counteract the vasoconstrictive properties of atherosclerotic arteries.
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143
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Hosoda K, Nakao K, Tamura N, Arai H, Ogawa Y, Suga S, Nakanishi S, Imura H. Organization, structure, chromosomal assignment, and expression of the gene encoding the human endothelin-A receptor. J Biol Chem 1992. [DOI: 10.1016/s0021-9258(19)37031-0] [Citation(s) in RCA: 125] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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144
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Sasaki K, Tanaka S, Ikeshita M, Sugimoto T, Imura H, Shoji T, Takano T, Tanaka K, Kumazaki T, Oya T. [Management of type A acute aortic dissection--results of the cases with thrombosed false lumen]. [ZASSHI] [JOURNAL]. NIHON KYOBU GEKA GAKKAI 1992; 40:1668-74. [PMID: 1402183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
By reviewing the outcome, we studied the propriety of our principles for the treatment of type A acute aortic dissection in 45 patients, encountered during the 10-year period between 1981 and 1990. We conducted a comparative study of patients with a thrombosed false lumen (type T) and a patent false lumen (type P) to examine the effect of an acutely thrombosed false lumen on the prognosis of this disease. For the 25 patients treated in the first 6 years (1981-1986), operation was performed as soon as exact diagnosis was made, regardless of the presence of complications and the type or severity of the disease. Early death occurred in 9/20 operated cases and in 4/5 unoperated cases, so 13/25 patients died for a 52.0% mortality rate. For the 20 patients who received treatment in the latter period (1987-1990), we gave priority to conservative treatment for type T cases that were free from complications, and adopted a treatment method attaching greater importance to the resection of intimal tears. As a results, early deaths were observed in only 4 type P patients (20.0%) who underwent operation, a significant better result (p < 0.05). For patients in whom we were able to excise the intimal tear (30.0%, early mortality rate), the results were better than in those in whom the intimal tear were left alone (53.8%). The results were particularly good in type T patients (25.0% of them underwent intimal tear resection and 71.4% underwent no operation for the intimal tear).(ABSTRACT TRUNCATED AT 250 WORDS)
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145
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Nakao K, Ogawa Y, Suga S, Imura H. Molecular biology and biochemistry of the natriuretic peptide system. I: Natriuretic peptides. J Hypertens 1992; 10:907-12. [PMID: 1328371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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146
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Sugawa H, Miyamoto M, Higuchi K, Smith E, Mori T, Imura H. Production and properties of novel human thyroid cancer specific monoclonal antibodies. Biochem Biophys Res Commun 1992; 187:404-12. [PMID: 1520327 DOI: 10.1016/s0006-291x(05)81507-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Monoclonal antibodies (TCM-7, -9 and -12) against human thyroid differentiated cancers were established by screening with human thyroid cancers, normal and benign thyroid tissue, and normal human serum protein. A monoclonal antibody (TCM-9) with strong specificity for human thyroid cancer but not for Graves' disease, adenoma or normal thyroid, was shown to recognize a 300 K protein but not to bind to native or mature human thyroglobulin. When TCM-9 was used in immunohistochemical staining tests on more than 30 types of non-thyroid lesions, no reactivity of TCM-9 was observed except with skin immature teratoma, lip squamous carcinoma and stomach adenocarcinoma, which revealed weak reactivities. TCM-9 also showed strong reactivity with two undifferentiated thyroid cancer cell lines and one tissue specimen. Thus TCM-9 is a novel monoclonal antibody against the thyroid cancer.
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147
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Nitta T, Tanaka S, Imura H, Terada K, Ikeshita M, Shoji T. [A case of idiopathic ventricular tachycardia with ventricular fibrillation successfully treated with cryoablations and implantable cardioverter defibrillator]. [ZASSHI] [JOURNAL]. NIHON KYOBU GEKA GAKKAI 1992; 40:1279-84. [PMID: 1402174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
A 16-year-old girl with medically refractory idiopathic ventricular tachycardia (VT) with ventricular fibrillation (VF) underwent cryoablations of the VT origin and received implantable cardioverter defibrillator (ICD). Intraoperative epicardial and endocardial mapping demonstrated the earliest activation site of VT in the infundibular septum of right ventricle. Cryoablations were applied through a pulmonary arteriotomy under mild hypothermic cardiopulmonary bypass with the heart beating. Because of the episodes of VF. ICD implantation was followed. Her postoperative course was uneventful and she remains free from VT and VF.
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148
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Sorachi K, Sugie K, Maekawa N, Takami M, Kawabe T, Kumagai S, Imura H, Yodoi J. Induction and function of Fc epsilon RII on YT cells; possible role of ADF/thioredoxin in Fc epsilon RII expression. Immunobiology 1992; 185:193-206. [PMID: 1452201 DOI: 10.1016/s0171-2985(11)80641-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The regulation of low-affinity Fc receptor for IgE (Fc epsilon RII) and the characteristics of both membrane and soluble forms of Fc epsilon RII were studied using YT cell line. We found that YT cells, a human NK like cell line, expressed Fc epsilon RII after IL-1 stimulation. Cross-linking of Fc epsilon RII on IL-1-stimulated YT cells as well as the transfectant of Fc epsilon RII-cDNA (YTSER) resulted in the up-regulation of IL-2R alpha (p55/Tac). A 59 kDa protein phosphorylated at tyrosine residues was co-immunoprecipitated with Fc epsilon RII from YTSER lysate using H107 anti-Fc epsilon RII mAb. YTSER not only expressed Fc epsilon RII on their surface but also secreted soluble form of Fc epsilon RII (sFc epsilon RII/sCD23; IgE binding factor). Affinity purification revealed that sFc epsilon RII released from YTSER is heterogeneous and consisted of several proteins differing in molecular weight. Both EBV+ B cells and HTLV-1+ T cells are high producers of ATL derived factor (ADF)/thioredoxin (TRX) and express Fc epsilon RII and IL-2R alpha respectively. To clarify the mechanism of Fc epsilon RII and IL-2R alpha induction by ADF/TRX, we examined the effect of ADF/TRX on the bindability of nuclear factor kappa B (NF-kappa B), which is known to regulate IL-2R alpha gene expression. In the gel shift assay, ADF/TRX was shown to enhance the bindability of NF-kappa B to its responsive element.
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149
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Takahashi T, Nakamura K, Nishikawa S, Tsuyuoka R, Suzuki A, Murakami M, Amenomori M, Okuno Y, Imura H. Interleukin-5 in eosinophilic gastroenteritis. Am J Hematol 1992; 40:295-8. [PMID: 1380204 DOI: 10.1002/ajh.2830400410] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
During a 4-year period a 28-year-old female had 4 episodes of eosinophilia of over 10,000/mu 1; these episodes were associated with nausea, vomiting, diarrhea, and abdominal pain. On one occasion, she had ascites and pleural effusion which contained numerous mature eosinophils. On each occasion, these attacks disappeared within several weeks without any specific treatment. A diagnosis of eosinophilic gastroenteritis was made. A plasma sample obtained during the eosinophilia generated in vitro eosinophilic colonies when added to granulocyte/macrophage-progenitor (CFU-GM) cultures without exogenous growth factors. Colony formation was inhibited by anti-interleukin-5 (IL-5) antibody but not by antibodies toward IL-3, granulocyte colony-stimulating factor (G-CSF) or GM-CSF. A high plasma interleukin-5 (IL-5) level was noted when measured by enzyme-linked immunosorbent assay, while IL-3, G-CSF, and GM-CSF were undetectable. During remission the plasma gave negative results both for colony formation and IL-5 level. These results indicate that the eosinophilia of this disease is mediated by IL-5.
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150
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Nishida N, Fukuda Y, Kokuryu H, Sadamoto T, Isowa G, Honda K, Yamaoka Y, Ikenaga M, Imura H, Ishizaki K. Accumulation of allelic loss on arms of chromosomes 13q, 16q and 17p in the advanced stages of human hepatocellular carcinoma. Int J Cancer 1992; 51:862-8. [PMID: 1322376 DOI: 10.1002/ijc.2910510605] [Citation(s) in RCA: 79] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
We examined loss of heterozygosity at 13 loci on 5 chromosomes in hepatocellular carcinomas (HCCs) from 56 patients. In 42 of these cases, regenerative nodules of liver cirrhosis were also analyzed. High frequencies of allelic losses were detected on chromosomes 13q (47%), 16q (40%) and 17p (64%), whereas losses on chromosome 4p and 11p were observed in less than 22% of cases in HCCs. In contrast, LOH was not detected on any loci in cirrhotic nodules. On chromosome 13q, the common region of allelic loss was mapped to the region including the retinoblastoma (RB) locus, by using 8 polymorphic probes. Furthermore, one case with 13q loss had an interstitial deletion of the RB gene, indicating the involvement of inactivation of the RB gene in hepatotumorigenesis. Losses were associated with portal-vein thrombosis or intrahepatic metastasis, increased tumor size, a poorly differentiated phenotype and clinical stage. Losses occurring together on 13q, 16q and 17p were significantly higher in patients in clinical stage IV or histologically poorly differentiated tumors, suggesting that the accumulation of allelic loss occurs in advanced tumors and that patients with multiple allelic losses may have a worse prognosis than those with a single loss.
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MESH Headings
- Alleles
- Carcinoma, Hepatocellular/complications
- Carcinoma, Hepatocellular/genetics
- Carcinoma, Hepatocellular/pathology
- Chromosome Banding
- Chromosome Deletion
- Chromosomes, Human, Pair 13
- Chromosomes, Human, Pair 16
- Chromosomes, Human, Pair 17
- DNA/genetics
- DNA/isolation & purification
- DNA, Neoplasm/genetics
- DNA, Neoplasm/isolation & purification
- Female
- Humans
- Liver Cirrhosis/complications
- Liver Cirrhosis/genetics
- Liver Cirrhosis/pathology
- Liver Neoplasms/complications
- Liver Neoplasms/genetics
- Liver Neoplasms/pathology
- Male
- Neoplasm Staging
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