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Biomedical subjects

H Sugihara

Publications and source records attributed to H Sugihara.

At least 433 records · Page 24Linked to original sources
PubMed1985

Isolation and characterization of hemorrhagic toxin g from the venom of Crotalus atrox (western diamondback rattlesnake).

Hemorrhagic toxin g (HT-g) was isolated from Crotalus atrox (western diamondback rattlesnake) venom using a five-step purification procedure to obtain approximately equal to 5.9 mg of purified HT-g from 2.0 g of crude venom. The purified toxin was homogeneous by disc electrophoresis on polyacrylamide gel at pH 8.3 and 4.3, and by isoelectric focusing. HT-g possessed lethal, hemorrhagic and proteolytic activities. These activities of toxin were inhibited by ethylenediamine-tetraacetic acid (EDTA), 1,10-phenanthroline or ethyleneglycol (beta-amino-ethyl) N,N,N',N'-tetracetic acid (EGTA), but not by cysteine or soybean trypsin inhibitor (SBTI). Its molecular weight was approximately 60,000 and the isoelectric point was 6.8. The toxin contains 516 amino acid residues. HT-g did not coagulate fibrinogen to fibrin; however, the toxin hydrolysed the A alpha-chain or B beta-chain of fibrinogen without cleaving the gamma-chain. HT-g produced only local hemorrhage in internal organs such as the intestine, heart and liver.

Amino Acids↗
PubMed1985

Hormone-dependent changes of blood vessels in DMBA-induced rat mammary carcinoma and its regression studied by 3H-thymidine autoradiography.

Using DMBA-induced rat breast cancer, the changes in the histology and proliferative activity underlying the phenomenon of tumor regression by hormone therapy were studied by 3H-thymidine autoradiography. The control tumor was found to essentially consist of two histologically different areas, medullary (A area) and tubular or cystic (B area). The cancer cells in the A area were homogeneously proliferating with a cell cycle time of 51h, and among those in the B area, 65% were proliferating with a cell cycle time of 81h while 35% were non-proliferating. Among the various-kinds of hormone therapies, ovariectomy plus male sex hormone administration was most effective in inducing tumor regression. In the regressed tumor, the A area was greatly diminished due to central necrosis and replaced by cystic B area. In the remaining A area, the cell cycle time was lengthened to 97h, and that for the proliferating cells in the B area was as long as 118h. The most striking histological change after ovariectomy plus male sex hormone administration was the diffuse necrosis of the capillary endothelial cell within 24h, followed by hemorrhage, central necrosis in the A area (1W), and final stage of fibrosis (2W). The tumor administered with female sex hormone after ovariectomy showed a rebound growth from the regression, due to the initial reactivation of the endothelial cell proliferation and following stimulation of cancer cell mitotic activity. From these observations, it is concluded that the capillary endothelial cells in DMBA-induced rat breast cancer are estrogen dependent, and that the tumor regression induced by decreased estrogen-level is attributable to the massive necrosis from capillary insufficiency and anoxia.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1985

Computer analysis of sub-parameters of depurination and depolymerization rate constants in Feulgen DNA hydrolysis.

Feulgen DNA hydrolysis curves derived from cytofluorometry at various temperatures and HCl concentrations were computer analyzed with least squares fit to Bateman function. By comparing the depurination (k1) and depolymerization (k2) rate constants at different hydrolysis conditions, it was found that the two parameters of temperature and HCl concentration can be expressed as k = AN2 X exp (-B/T), where A and B are constants, N is the HCl concentrations, and T is the absolute temperature. From the analysis of Feulgen hydrolysis curves with 2N HCl at various temperatures, it was calculated that A = 5.3590 X 10(14) and B = 12133.543, for k1, and A = 6.2401 X 10(14) and B = 12181.660, for k2 for mouse 4C hepatocytes fixed with absolute methanol. Computer generated theoretical hydrolysis curves using the above k1 and k2 values were compared with experimental curves at various temperatures and HCl-concentrations. The two types of hydrolysis curves coincided with each other when 1-3 N HCl was used at temperatures between 30-40 degrees C. The peak times of hydrolysis curves at different conditions determined by experimental analysis and theoretical estimations also coincided reasonably well with each other. The physico-chemical phenomena underlying the equation designating k1 and k2 values are discussed.

Animals↗
PubMed1985

[Exercise echocardiography to evaluate left ventricular function in mitral and aortic regurgitation].

To assess differences in left ventricular (LV) performance between mitral regurgitation (MR) and aortic regurgitation (AR), exercise echocardiography was performed for 12 patients with MR and 18 patients with AR, and the results were compared with those of 11 normal subjects. These patients with LV volume overloads were all in the NYHA class I or II. There were no differences in age or sex distributions between the two groups. Symptom-limited submaximal exercise was performed on an ergometer in the supine position. The results obtained were as follows: LV dimensions at end-diastole (EDD) and end-systole (ESD) were greater in the diseased groups than in the normal group. Resting EDD and ESD showed no differences between the MR and the AR groups. There were no differences in exercise-induced increases in heart rates or elevations of systolic blood pressures among the three groups. During exercise, EDD increased and ESD decreased in the normal group, and similar results were obtained for the MR group. However, in the AR group, EDD and ESD remained unchanged. Ten of the 18 patients with AR had decreased ESD, and eight had unchanged or increased ESD during exercise. Resting shortening fractions were equally distributed among the three groups. During exercise, the shortening fractions were significantly increased in the normal and the MR groups. In the AR group, shortening fractions remained at resting values, with variable responses in individual cases. Systolic wall thickening of the interventricular septum and the LV posterior wall showed similar responses of shortening fractions. The relation between the peak systolic wall stress index (PSSI) and ESD, or PSSI and the shortening fraction revealed that exercise induced an afterload mismatch of LV performance in some patients with AR. Thus, though resting LV performances did not differ from each other, an afterload mismatch is more easily induced with exercise in patients with AR than in patients with MR. This may be one of the cause of the different clinical courses in these two groups with LV volume overloads.

Adult↗
PubMed1985

[Coronary reserve of the right ventricle evaluated by double dose T1-201 scintigraphy].

Thallium-201 double dose scintigraphy was applied to exercise to estimate the coronary blood flow reserve of the left and right ventricles and this was compared with the degree of coronary artery stenosis. As an index of coronary reserve we measured the rate of change of blood flow distribution (delta F) calculated from the change in myocardial radioactivity following thallium-201 injections, once at rest and once during exercise. With submaximal exercise the increases in delta F of the left ventricle were less in patients with ischemic heart disease than in the control subjects, and were less as the number of diseased coronary vessels increased. The increases of delta F of the right ventricle were less in patients with stenosis of the proximal portion of the right coronary artery than in patients without stenosis and in the control subjects. The more severe the stenosis of the proximal portion of the right coronary artery, the smaller the delta F of the right ventricle. These results indicate that evaluation of the delta F in the left and right ventricles is useful in estimating coronary artery stenosis.

Coronary Circulation↗
PubMed1984

Analysis of DNA ploidy patterns of gastric carcinomas of Japanese.

Ploidy patterns of gastric carcinomas of 54 Japanese patients, ranging in age from 28 to 82 years, were determined by cytofluorometry. The gastric cancers were divided into four basic ploidy patterns; the first pattern was a diploid mode, the second was a heteroploid mode, the third was a mosaic pattern of a diploid and a heteroploid mode, and the fourth was a mosaic of two or more different heteroploid modes. The incidence was 68.4%, 14.8%, 12.9%, and 3.7% in the first, second, third, and fourth patterns, respectively. All the cancers contained polyploid populations, whereas the early cancers tended to contain a lesser amount of polyploid cells than the advanced ones. Diffuse-type cancers and well-differentiated, intestinal-type adenocarcinomas were mostly unimodal cancers of the diploidy or heteroploidy, whereas poorly differentiated adenocarcinomas were often mosaic cancers of several different ploidies. There was no correlation between ploidy patterns and ages and sexes of patients. For 11 cases, labeling indices with 3H-thymidine were determined. Labeling indices of the intestinal-type and diffuse-type cancers were 12% to 27% and 7% to 19%, respectively.

Adenocarcinoma↗
PubMed1984

Development of chicken epidermis cultured with embryo extract.

The epidermis from 11-day-old chick embryo shank skin was cultured with 11-day-old chick embryo extract. The growth and the differentiation of the epidermis in culture were studied histologically, electron microscopically and with polyacrylamide gel electrophoresis of keratin proteins. The epidermis cultured with the chick embryo extract proliferated and stratum structures developed simultaneously with the increase in epidermal cell layers. Finally, a keratinized layer was observed after 10 days in culture. Electron microscopic observations revealed that tonofilaments were produced after 2 days in culture and increased thereafter with culture time, becoming condensed with desmosomes. Keratohyaline granules were observed in 7-day cultures. These keratinization characteristics occurring during culture showed the general characteristics of the alpha stratum observed in the skin of in ovo embryos during the early stages of development. However, the development of peridermal and subperidermal granules was poor and the stratum granulosum, which develops at the late stages between the stratum intermedium and the stratum corneum, was not observed. Polyacrylamide gel electrophoresis of S-carboxymethylated keratin proteins showed that the keratin protein band patterns of the culture differed from those of in ovo skin epidermis.

Animals↗
PubMed1984

Isolation and biochemical characterization of hemorrhagic toxin f from the venom of Crotalus atrox (western diamondback rattlesnake).

Hemorrhagic toxin f (HT-f) was isolated from Crotalus atrox (Western Diamondback Rattlesnake) venom by a five-step purification procedure. Homogeneity was established by the formation of a single band in acrylamide gel electrophoresis, isoelectric focusing, and sodium dodecyl sulfate (SDS)-electrophoresis. HT-f has a molecular weight of 64,000 and contains 572 amino acid residues. It contains 1 mol of zinc per mol of protein. Zinc is essential for both hemorrhagic and proteolytic activities. HT-f possesses proteolytic activity hydrolyzing the Val-Asn, Gln-His, Leu-Cys, His-Leu, Ala-Leu, and Tyr-Leu bonds of oxidized insulin B chain. HT-f did not coagulate fibrinogen to fibrin, yet it did hydrolyze the gamma chain of fibrinogen without affecting either the A alpha or B beta chains. This is the first time that a hemorrhagic toxin was shown to have fibrinogenase activity. HT-f was shown to differ immunologically from other hemorrhagic toxins such as HT-a and HT-c. HT-f also possesses lethal toxicity. When zinc was removed the apo-HT-f lost its lethal toxicity. HT-f produced not only local hemorrhage in the skin and muscle, but also produced systemic hemorrhage in internal organs such as the intestine, kidney, lung, heart, and liver.

Amino Acids↗
PubMed1984

Purification of a proteinase (Ac5-proteinase) and characterization of hemorrhagic toxins from the venom of the hundred-pace snake (Agkistrodon acutus).

Ac5-Proteinase (15.2 mg) was isolated from Agkistrodon acutus venom (1 g) by column chromatography on Sephadex G-75, CM-Sephadex C-50 and CM-Cellulose. Ac5-Proteinase was homogeneous by disc electrophoresis on polyacrylamide gel at pH 4.3 and also by SDS-disc polyacrylamide gel electrophoresis. Ac1-, Ac2-, Ac3- and Ac5-proteinases possessed lethal and hemorrhagic activities, but Ac4-proteinase had no lethal activity. These activities were inhibited completely by ethylenediaminetetraacetic acid (EDTA), 1,10-phenanthroline or cysteine. The molecular weights of Ac1-, Ac2-, Ac3-, Ac4- and Ac5-proteinases were approximately 24,500, 25,000, 57,000, 33,000 and 24,000, respectively. Ac1-, Ac2-, Ac4- and Ac5-proteinases did not contain any carbohydrates, but Ac3-proteinase contained 0.1% carbohydrate by weight.

Amino Acids↗
PubMed1984

Purification and characterization of arginine ester hydrolases from the venom of the Chinese habu snake (Trimeresurus mucrosquamatus).

An arginine ester hydrolase (ME-5) was isolated from the venom of Trimeresurus mucrosquamatus by column chromatography on Sephadex G-100, CM-Sephadex C-50, DEAE-Sephacel and by isoelectric focusing, obtaining 1.4 mg of purified enzyme from 1 g of crude venom. The enzyme was homogeneous by SDS disc electrophoresis on polyacrylamide gel at pH 8.3. ME-5 is a glycoprotein which possesses both TAME hydrolase and capillary permeability-increasing activity, but it did not show clotting or bradykinin-releasing activities. Its molecular weight is approximately 33,000 and its isoelectric point is 6.48. The enzyme is stable to heat treatment and to pH changes between 5 and 9. Trimeresurus mucrosquamatus venom contains five arginine ester hydrolases, designated as ME-1, 2, 3, 4 and 5. Three of the five (ME-1 , 4 and 5) are inactivated by DFP, suggesting that the serine hydroxyl group is involved in enzymatic activity. All five arginine ester hydrolases showed capillary permeability-increasing activity, but none of the enzymes showed clotting activity. Their amino acid compositions were determined and all appear to be unique and distinct from those of other snake venoms.

Amino Acids↗
PubMed1984

Comparative study of Agkistrodon acutus venoms from China and Taiwan.

Three hemorrhagic toxins (Ac1-, Ac2- and Ac3-proteinases) were isolated from the lyophilized venom of Agkistrodon acutus from China using gel filtration on a Sephadex G-75 column, followed by chromatography on diethylaminoethyl (DEAE)-Sephadex A-50, DEAE-Sephacel and DEAE-cellulose. Homogeneity was established by the formation of a single band in acrylamide gel electrophoresis, isoelectric focusing and sodium dodecyl sulfate (SDS) acrylamide gel electrophoresis. Three hemorrhagic toxins possessed both lethal and proteolytic activities. These activities were inhibited by ethylenediamine tetraacetic acid (EDTA), ethyleneglycol (beta-aminoethyl)N,N,N',N'-tetraacetic acid (EGTA), o-phenanthroline or cysteine, but not by soybean trypsin inhibitor (SBTI), p-chloromercuribenzoate (PCMB) or diisopropyl fluorophosphate (DFP). Molecular weight of hemorrhagic toxins (Ac1-, Ac2- and Ac3-proteinases) were determined to be 24,500, 25,000 and 57,000, respectively. It was found that hemorrhagic toxins have considerable similarity to hemorrhagic toxins isolated by Nikai et al. (1977) and Sugihara et al. (1978, 1979), but Ac2- and Ac3-proteinases from China and Taiwan are electrophoretically unrelated.

Amino Acid Sequence↗
PubMed1984

Effect of prostaglandin E1 on fractional distribution of cardiac output and organ blood flow in man: a simultaneous and non-invasive determination using double dose thallium-201 scintigraphy.

Taking advantage of the fact that the distribution of Thallium-201 in an organ almost parallels the blood flow to the organ, we devised a non-invasive method of simultaneously determining blood flow and its distribution in human organs. With this method, we investigated the effect of exogenous prostaglandin E1 (PGE1) on the central and peripheral circulation. Scintigraphy was performed after two injections of 201Tl chloride, one at rest and one after the administration of PGE1 or saline. In eight subjects given PGE1 (0.2 microgram X kg-1 X min-1, iv), blood pressure fell, whereas both heart rate and cardiac output rose. The fractional distribution was increased in the heart (+13.3 +/- 2.98%, mean +/- SD), but decreased in the liver (-10.2 +/- 1.95%) and gastro-intestinal tract (-7.09 +/- 2.65%). No significant change was observed in the kidneys or leg. The blood flow in all these organs was increased. In the six control subjects given saline, there was no change in these central and peripheral haemodynamics. Thus, the intravenous infusion of PGE1 in man causes uneven blood flow distribution in heart, liver, kidney, gastro-intestinal organs and leg muscles, despite increased blood flow to all these organs. The method used in this study is relatively non-invasive and useful in evaluating organ blood flow in man, and seems to be widely applicable to physiological and pharmacologic research.

Alprostadil↗
PubMed1984

Atypical polysplenia only with absence of the hepatic segment of inferior vena cava in a middle-aged.

An autopsy case of polysplenia with absence of the hepatic segment of the inferior vena cava in a 53-year-old female is reported. The venous blood from the lower parts of the body was drained through the azygos vein and the superior vena cava into the right atrium. Other than acquired pathological change, the heart was found to be normal. Except for the partial absence of the inferior vena cava, isomerism of asymmetric organs, and heterotaxia of abdominal organs, characteristic of typical polysplenia, were not present. This case of atypical polysplenia suggests the presence of a transitional form in the complex.

Azygos Vein↗