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Biomedical subjects

H Sugihara

Publications and source records attributed to H Sugihara.

At least 73 records · Page 4Linked to original sources
PubMed2000

Can serum carnitine levels distinguish hypertrophic cardiomyopathy from hypertensive hearts?

Although echocardiography is a useful diagnostic tool in hypertrophic cardiomyopathy (HCM), it is sometimes difficult to differentiate it from hypertensive heart disease (HHD): some patients with HCM show symmetrical hypertrophy, whereas patients with HHD sometimes show asymmetrical septal hypertrophy. We used a radioiodinated long-chain fatty acid tracer to visualize the altered myocardial fatty acid metabolism of HCM and HHD. Carnitine is the essential substance for the beta-oxidation of long-chain fatty acids. We recently reported that serum free carnitine levels in HCM were elevated and that they were significantly correlated with the severity of myocardial fatty acid metabolic disorder. Therefore, we investigated serum carnitine levels in patients with HCM and HHD, which can contribute to the differentiation of each other. We studied 56 patients with HCM and 20 patients with essential hypertension. Serum free carnitine levels were significantly higher in patients with HCM than those with HHD (HCM 52.5+/-9.5 nmol/mL, HHD 46.6+/-6.4 nmol/mL, P<0.01), but they showed no statistical difference between patients with HHD and normal subjects. Serum acylcarnitine levels were significantly lower in patients with HCM than those with HHD (HCM 10.1+/-4.0 nmol/mL, HHD 14.5+/-4.9 nmol/mL, P<0.0005), although they did not differ between patients with HHD and normal subjects. Scintigraphic analyses with a long-chain fatty acid analog revealed that myocardial tracer uptake was much reduced in patients with HCM compared with that in patients with HHD (quantitative analysis: HCM 2.11+/-0.12, HHD 2.22+/-0.17, P<0.05; semiquantitative analysis: HCM 13.6+/-6.3, HHD 2.0+/-1.5, P<0.0001). In conclusion, the differences in serum carnitine levels between HCM and HHD reflect altered myocardial fatty acid metabolic impairment, and the levels can help to distinguish these 2 diseases.

Adult↗
PubMed2000

Central effect of ghrelin, an endogenous growth hormone secretagogue, on hypothalamic peptide gene expression.

Ghrelin, an endogenous ligand for the growth hormone secretagogue receptor (GHS-R), was originally purified from the rat stomach. Like the synthetic GHSs, ghrelin specifically releases GH following intravenous administration. Also consistent with the central actions of GHSs, ghrelin-immunoreactive cells were shown to be located in the hypothalamic arcuate nucleus as well as the stomach. However, the central actions of ghrelin have not been elucidated. Here, we used radioactive in situ hybridization histochemistry to examine the effects of central administration of rat ghrelin on neuropeptide genes that are expressed in hypothalamic neurons that were previously shown to express GHS-R. We found that central administration of ghrelin increased both agouti-related protein (AGRP) mRNA levels (245.8 +/- 28.3% of the saline-treated controls; p < 0.01) in the hypothalamus and food intake (5.7 +/- 0.9 g ghrelin vs. 1.9 +/- 0.5 g saline; p < 0.05). On the other hand, 1 microg of rat ghrelin central administration did not alter the episodic GH release of freely moving adult male rats. Thus, ghrelin has an alternative role in stimulating food intake via an increase of AGRP rather than the release of GH from the pituitary.

Agouti-Related Protein↗
PubMed2000

[Studies on hemorrhagic toxins from the venoms of Trimeresurus mucrosquamatus, Crotalus ruber ruber, Vipera aspis aspis and Agkistrodon acutus and arginine ester hydrolases from Trimeresurus mucrosquamatus venom].

Venom samples were corrected from several poisonous snakes, such as Bungarus multicinctus, Trimeresurus mucrosquamatus, T. gramineus, T. flavoviridis, and Agkistrodon acutus, and stored in a desiccator at room temperature for 25 to 31 years. Then they were compared with fresh venoms as to their biological activities. The characteristic local symptoms produced by the bite of venomous snakes of Crotalidae and Viperidae are hemorrhage, necrosis and muscular degeneration. Hemorrhagic toxins were purified from Trimeresurus mucrosquamatus, Crotalus ruber ruber, Vipera aspis aspis, and Agkistrodon acutus venoms and their biological, biochemical, and pathological properties were investigated. Arginine ester hydrolases are present in the venoms of Crotalidae and Viperidae, but are not found in the venoms of Elapidae and Hydrophiidae. In this paper we describe the enzymatic and biological activities of arginine ester hydrolases from a Trimeresurus mucrosquamatus venom.

Amino Acid Sequence↗
PubMed2000

[Two cases of microvascular vasospastic angina usefulness of 99mTc-tetrofosmin myocardial SPECT in clinical diagnosis].

Case 1 involved a 52-year-old man with angina chest pain at rest and case 2 involved a 63-year-old woman with chest oppression at rest. An electrocardiogram (ECG) showed negative T wave in III and aVF leads in case 1, and complete atrioventricular block and ST segment depression in II, III, aVF, and V5-6 leads in case 2. In both cases, 99mTc-tetrofosmin myocardial SPECT showed reduced uptake in the inferior and posterior wall. Although bath patients' left coronary arteriographies were normal, right coronary arteriographies revealed severely delayed filling of contrast medium without significant narrowing of epicardial coronary arteries, suggesting microembolism or microvascular vasospasm. An intracoronary infusion of isosorbide dinitrate did not improve the delayed filling of contrast medium or ST segment depression on ECG. Soon after intracoronary infusion of diltiazem in case 1 and nicorandil in case 2, coronary arterial flows were normalized, chest symptoms disappeared, and ECG findings were normalized. The next day, both patients' 99mTc-tetrofosmin myocardial SPECT showed normal uptake. These findings suggest that myocardial ischemia in these cases might be explained as having been caused by microvascular spasm.

Calcium Channel Blockers↗
PubMed2000

[Impairment of septal uptake and washout on 123I-BMIPP myocardial SPECT after pacemaker implantation: report of two cases].

Case 1 involved a 62-year-old woman with complete atrioventricular block and case 2 involved a 70-year-old woman with sick sinus syndrome. In both cases, echocardiography, 123I-15-(p-iodophenyl)-3-R,S-methyl pentadecanoic acid (BMIPP) and 99mTc-tetrofosmin myocardial single photon emission computed tomographic (SPECT) findings were normal. Coronary arteriography and left ventriculography also revealed normal in both cases. After pacemaker implantation (DDD-type in case 1 and VVI-type in case 2), both patient's electrocardiograms revealed left bundle branch block-type conduction disturbance, and echocardiography showed asynchronous hypokinesia in the septal region. One year later, although both patient's ATP loading tetrofosmin SPECT were normal, BMIPP SPECT showed reduced uptake and increased washout in the septal region. These findings suggest that these changes of BMIPP SPECT might be caused by left bundle branch block-type conduction disturbance after pacemaker implantation.

Aged↗
PubMed2000

[Clinical usefulness of delayed exercise images on 99mTc-Tetrofosmin myocardial SPECT in the diagnosis of vasospastic angina pectoris].

This study was designed to evaluate the clinical usefulness of delayed exercise images in 99mTc-tetrofosmin (TF) myocardial SPECT in the diagnosis of vasospastic angina pectoris. We studied 30 patients with vasospastic angina, 10 of 30 patients (group A) had both effort and rest angina, 20 of 30 patients (group B) had rest angina. A 370 MBq of TF was intravenously injected at peak exercise, and initial (EX-I) and delayed exercise (EX-D) images were obtained at 30 min and 180 min after the injection. An additional 740 MBq of TF was intravenously reinjected after EX-D image acquisition, and rest images were obtained 30 min after the reinjection. The left ventricular wall was divided into 9 segments. Regional myocardial uptakes of TF were scored by 4-point defect score (0 = normal, 1 = mildly reduced, 2 = moderately reduced, and 3 = severely reduced). Total defect score (TDS) was calculated from the sum of defect scores in 9 segments. Reverse redistribution (RR) was defined as increase of more than 2 in TDS on EX-D images. In group A, 4 of 10 cases (40%) showed decreased uptake on EX-I images, 6 of 10 cases (60%) revealed RR on EX-D images, and none of the patients showed decreased uptake on rest images. In group B, no one showed decreased uptake on EX-I and rest images, 11 of 20 cases (55%) revealed RR on EX-D images. The mean +/- SD of TDS were 2.9 +/- 3.4, 5.1 +/- 4.5, 0.5 +/- 0.5 on EX-I, EX-D, rest images in group A, and serially 0.4 +/- 0.5, 3.3 +/- 3.6, 0.4 +/- 0.5 in group B. Regional wall motion abnormality was reduced in regions with RR. RR on EX-D images may reflect ischemic damaged but viable myocardium in vasospastic angina. The clinical usefulness of exercise-rest TF imaging in detection of organic coronary artery disease has been well established. Therefore, exercise-rest TF imaging with additional delayed exercise image could evaluate not only organic coronary artery disease but also coronary artery vasospasm.

Aged↗
PubMed2000

Edema factor from the venom of Trimeresurus elegans (Sakishimahabu).

An edema factor was isolated from the venom of Trimeresurus elegans using HW-55, CM-Cellulose, and Mono S column chromatographies. Homogeneity was demonstrated by the formation of a single band in polyacrylamide gel electrophoresis (pH 8.3). The edema factor has a molecular weight of 25,500, an isoelectric point of 7.5, and express edema, proteolytic and capillary permeability-increasing activities. Edema, proteolytic and capillary permeability-increasing activities are inhibited by ethylenediaminetetraacetic acid (EDTA), o-phenanthroline, and N-bromosuccinimide. Additionally, this factor exhibits kinin-releasing activity. The edema factor possesses proteolytic activity as shown by hydrolyzing the Val(3)-Asn(4), His(5)-Leu(6), Ser(9)-His(10), Ala(14)-Leu(15), Leu(15)-Tyr(16), Tyr(16)-Leu(17), and Glu(21)-Arg(22) bonds of oxidized insulin B chain. The A alpha, B beta, and gamma chains of human fibrinogen were also hydrolyzed. The edema factor was found to contain 1 mol of zinc and 2 mols of calcium per mol of protein and the amino-terminal sequence was determined.

Amino Acid Sequence↗
PubMed2000

[Clinical usefulness of 123I-BMIPP myocardial SPECT in collagen disease].

This study was designed to evaluate the clinical usefulness of 123I-BMIPP myocardial SPECT for detecting cardiac involvement in patients with collagen disease. We studied 12 patients with systemic lupus erythematosus (SLE), 8 with progressive systemic sclerosis (PSS), 6 with polymyositis/dermatomyositis (PM/DM) and 3 with allergic granulomatosis and angiitis (AGA). A 111 MBq of 123I-BMIPP was intravenously injected at rest, and SPECT images were obtained at 15 min after the injection. Seven of 12 SLE, 6 of 8 PSS, 3 of 6 PM/DM and all 3 AGA patients showed an abnormal tracer uptake. The left ventricular ejection fraction was inversely correlated with a BMIPP abnormality. The regional wall motion abnormality was reduced in regions with reduced tracer uptake. These findings suggest that 123I-BMIPP imaging could be useful for assessment of cardiac involvement in patients with collagen disease.

Aged↗
PubMed2000

[Is myocardial impairment in idiopathic dilated hypertrophic cardiomyopathy reversible by carvedilol?: a case report].

A 64-year-old woman with dilated hypertrophic cardiomyopathy was treated by beta-blocker, because of recurrent episodes of congestive heart failure. Carvedilol administration was started with a dose of 2.5 mg/day, and gradually increased to the dose of 20 mg/day 3 months later. Her functional class recovered from New York Heart Association stage IV to stage II. Thallium-201 scintigraphy demonstrated advanced myocardial damage: defect/low perfusion in the anteroseptal, infero-posterior and apical regions. Iodine-123 beta-methyl-p-iodophenyl-pentadecanoic acid scintigraphy confirmed these findings. However, the scintigraphic abnormalities had reversed to near normal perfusion and metabolism similar to those of stunned myocardium after an ischemic episode. This case demonstrates the recovery of myocardial impairment during beta-blocker therapy in a patient with dilated hypertrophic cardiomyopathy.

Adrenergic beta-Antagonists↗
PubMed1999

Effect of insulin-like growth factor-I on growth hormone-releasing factor receptor expression in primary rat anterior pituitary cell culture.

We examined the effect of insulin-like growth factor-I (IGF-I) on GH-releasing factor (GRF) receptor expression in the primary rat anterior pituitary cell culture. The levels of GRF receptor mRNA were dose-dependently reduced by IGF-I treatment for 24 h. To clarify whether altered levels of GRF receptor mRNA contribute to GRF receptor concentrations, we examined the GH response to GRF in vitro. There was no difference in basal GH secretion between control and IGF-I pretreated cells, while GRF-stimulated GH secretion in cells pretreated with IGF-I for 24 h was significantly lower than that in control cells. Moreover, specific [125I] Tyr10-human GRF binding to pituitary cells was reduced significantly by IGF-I treatment. These results suggest that IGF-I acts directly on the pituitary and participates in the regulation of GRF receptor expression.

Animals↗
PubMed1999

A new planar multielectrode array for extracellular recording: application to hippocampal acute slice.

The present paper describes a new planar multielectrode array (the MED probe) and its electronics (the MED system) which perform electrophysiological studies on acute hippocampal slices. The MED probe has 64 planar microelectrodes, is covered with a non-toxic, uniform insulation layer, and is further coated with polyethylenimine and serum. The MED probe is shown to be appropriate for both stimulation and recording. In particular, multi-channel recordings of field EPSPs obtained by stimulating with a pair of planar microelectrodes were established for rat hippocampal acute slices. The recordings were stable for 6 h. Finally a spatial distribution of long-term potentiation was studied using the MED system.

Animals↗
PubMed1999

Vascular endothelial growth factor VEGF-like heparin-binding protein from the venom of Vipera aspis aspis (Aspic viper).

The heparin-binding dimeric hypotensive factor (HF) was purified from Vipera aspis aspis (Aspic viper) venom [Komori, Y. and Sugihara, H. (1990) Toxicon 28, 359-369]. In this study, the amino acid sequence, and structure and function of HF, were elucidated. By electrospray ionization mass spectrometry (ESI-MS), the molecular weight of HF was determined to be 25 072.1. The complete amino acid sequence of HF was determined by Edman sequencing of the S-pyridylethylated HF and its peptides derived from enzymatic digestion. The theoretical molecular mass calculated from the primary structure agrees well with the molecular weight determined by ESI-MS. HF consists of two homogeneous monomers bound covalently. The monomer with an N-terminal blocked by pyroglutamic acid contains 110 amino acid residues, including eight cysteine residues, two of which are considered to be involved in intermolecular disulfide bonds. Sequential homology search revealed that the primary structure of HF is similar to that of vascular endothelial growth factor (VEGF) and platelet-derived growth factor (PDGF) with a sequential homology of 45 and 22%, respectively. When injected intradermally into a rat, an increase in capillary permeability was observed with HF or VEGF. On the other hand, only HF exerted a strong hypotensive effect after intravenous injection of samples into a rat. Purified HF has a mitogenic effect on endothelial cells. Through the use of bovine aortic endothelial cells (BAEC), the half-maximal mitogenic concentration of HF was determined to be 5-5. 5 nM (125-138 ng/mL). Similarly, VEGF had a mitogenic concentration at 0.5-1 nM. When incubated with HF and cycloheximide or HF and heparin, the cell growth was inhibited, suggesting that the mechanism of action of HF is similar to that of VEGF.

Amino Acid Sequence↗
PubMed1999

Effects of stromal fibroblasts and fat cells and an environmental factor air exposure on invasion of laryngeal carcinoma (HEp-2) cells in a collagen gel invasion assay system.

OBJECTIVE: To clarify the invasion mechanism of laryngeal carcinoma (HEp-2) cells. DESIGN: Human HEp-2 cells were cultured on a collagen gel containing fibroblasts and/or fat cells. The HEp-2 cells were also treated with air exposure as the local environment of the laryngeal epithelial mucosa. A collagen gel invasion assay was conducted under these culture conditions. RESULTS: No invasion of HEp-2 cells was found in the stromal cell-free collagen gel, but a slight invasion was observed in the fibroblast-embedded gel. A deeper invasion of HEp-2 cells occurred in the fibroblast- and fat cell-coembedded gel and in the fibroblast-embedded gel with air exposure. The most extensive invasion of HEp-2 cells was observed under the fibroblast- and fat cell-coembedded gel in combination with air exposure. CONCLUSIONS: Fat cells and air exposure clearly increase the invasive effect of fibroblasts in squamous cell carcinoma of the larynx. The combined effect of these 3 factors (ie, fat cells, fibroblasts, and air exposure) plays a very important role in the invasive growth of the carcinoma cells. This observation suggests that both tumor cell-stromal cell interaction and tumor cell-local environmental factor interaction should be taken into account in an investigation of the invasive and proliferative mechanisms of laryngeal carcinoma.

Adipose Tissue↗
PubMed1999

Immunohistochemical expression of growth factors in subacute thyroiditis and their effects on thyroid folliculogenesis and angiogenesis in collagen gel matrix culture.

The inflammatory-mechanistic basis of subacute thyroiditis remains unclear. To elucidate the roles of vascular endothelial cell growth factor (VEGF), basic fibroblast growth factor (bFGF), platelet-derived growth factor-BB (PDGF), transforming growth factor-beta1 (TGF-beta1) and epidermal growth factor (EGF) in the inflammatory process, their immunoexpression was examined in biopsy specimens of ten cases. At the granulomatous stage, all cases expressed VEGF, bFGF, PDGF, and TGF-beta1 in monocytes/macrophages infiltrating into follicle lumina, and in both epithelioid histiocytes and multinucleated giant cells of the granulomas. In fibroblasts and endothelial cells around the granulomas, all cases displayed VEGF, bFGF, and PDGF, but TGF-beta1 was detected only in fibroblasts in two cases. No cases expressed EGF in any of the above cell types. At the regenerative stage, all cases expressed VEGF, bFGF, and EGF in regenerating thyrocytes, whereas three and no cases displayed PDGF and TGF-beta1, respectively. Ten, seven and six cases expressed PDGF in fibroblasts, endothelial cells, and monocytes, respectively. In these cell types, all cases expressed VEGF and bFGF, whereas no cases displayed TGF-beta1 and EGF. To estimate the roles of these growth factors in thyroid tissue regeneration, their effects on thyroid folliculogenesis and angiogenesis were examined using collagen gel culture of thyrocytes and endothelial cells, respectively. Cell proliferation was also studied by bromodeoxyuridine (BrdU) uptake. EGF decreased follicle formation and TGF-beta1 drastically inhibited it, but the others had no effect. VEGF showed the greatest effect on vessel formation, although all of the others promoted it. EGF and VEGF or bFGF caused the highest BrdU uptake in thyrocytes and endothelial cells, respectively. The data suggest firstly, that at the granulomatous stage of subacute thyroiditis, growth factor-rich monocytes/macrophages infiltrating into follicle lumina trigger the granulomatous reaction, and VEGF, bFGF, PDGF, and TGF-beta1 produced by the stromal cell types tested mediate the reaction; secondly, that at the regenerative stage, EGF serves follicle regeneration through its mitogenic effect on thyrocytes, although some cofactors with EGF are involved in folliculogenesis and the decreased expression of TGF-beta1, a fibrogenic factor, contributes to thyroid tissue repair; and thirdly, that VEGF and bFGF are more responsible for the angiogenesis at both stages than the other factors studied.

Cell Culture Techniques↗