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Biomedical subjects

Y Ohno

Publications and source records attributed to Y Ohno.

At least 667 records · Page 37Linked to original sources
PubMed1981

High-performance aqueous gel permeation chromatography of serum lipoproteins: selective detection of cholesterol by enzymatic reaction.

A rapid method for the quantitation of cholesterol in each lipoprotein fraction has been developed which utilizes high-performance aqueous gel permeation chromatography followed by enzymatic reaction using reaction-type high-performance chromatography. Cholesterol in serum lipoproteins eluted from the column could be sensitively and selectively detected by the absorbance at 550 nm following the enzymatic reaction. The sensitivity of the detection for cholesterol measured by A550 was compared with that for protein measured by A280 using the standard lipoprotein fractions: low-density lipoprotein (LDL) and high-density lipoproteins (HDL2 and HDL3). The effects of changing the flow-rate and lengthening the column on the resolution of LDL and HDL were examined. Analyses of serum protein and cholesterol were performed with this method for human and animal subjects.

Animals↗
PubMed1981

Rapid method for the quantitation of cholesterol in human serum lipoproteins by high performance liquid chromatography.

A simple and rapid method for the quantitation of cholesterol in human serum lipoproteins (VLDL, LDL, HDL2, and HDL3) was developed (1). The content of cholesterol in each lipoprotein fraction was determined by means of a commercial enzymatic reaction kit after separation by high performance liquid chromatography with gel permeation columns. The quantitation of cholesterol could be performed with only 10-20 mu l of serum in less than 50 min by measuring A550 after passing the mixed eluate and enzyme solution through an on-line reactor system of a high-speed chemical derivatization liquid chromatograph. The precision, reproducibility and sensitivity of the quantitation of cholesterol with this method were acceptable, and the values of HDL-cholesterol determined by this method correlated well with those found by the heparin-manganese chloride precipitation method (r=0.958, n=93).

Cholesterol↗
PubMed1981

Fractionation of human serum lipoproteins by high performance liquid chromatography. I.

Immunologically pure lipoprotein fractions of human serum were subjected to high performance liquid chromatography (HPLC) on a combination system of aqueous gel permeation columns. Each lipoprotein fraction appeared at a distinct elution volume as a single homogeneous peak. Elution was carried out with 0.1 M Tris-HCl buffer solution, pH 7.4, or 0.15 M NaCl solution and no significant differences in elution volume and elution pattern were found. The lipoprotein mixtures (total lipoprotein fraction d less than 1.210) of healthy and pathological subjects were subjected to HPLC and showed characteristic elution patterns which could be of diagnostic significance.

Cholesterol↗
PubMed1981

A new fluorogenic peptide substrate for vitamin K-dependent blood coagulation factor, bovine protein C.

Protein C is a precursor of plasma serine proteinases, and its active form inactivates specifically blood coagulation Factor V and Factor VIII. Since a specific and sensitive synthetic substrate for the activated protein C was not known, we studied its amidolytic activity toward 25 fluorogenic peptides of the type peptidyl-4-methylcoumaryl-7-amide (peptidyl MCA). The activated protein C, namely, bovine protein C activated by bovine alpha-thrombin, showed the highest activity toward Boc-Leu-Ser-Thr-Arg-MCA. The enzyme's Km and Kcat values for this substrate were calculated to be 3.3 x 10(-4) M and 8.4 s-1, respectively. Optimum conditions for measurement of activated protein C activity were studied with this substrate. Optimum pH was 8.5. For the maximum activity at pH 8.5, concentrations of 0.1 M NaCl and 1 mM CaCl2 had to be maintained in the reaction mixture. The fluorogenic peptide Boc-Leu-Ser-Thr-Arg-MCA was successfully applied to a simple and accurate assay of protein C during its purification.

Animals↗
PubMed1981

Giant cell carcinoma of the pancreas.

A case of giant cell carcinoma of the pancreas is reported herein. The patient is a 67-year-old Japanese woman complaining of ascites, general fatigue, loss of weight, abdominal distention, nausea, and vomiting. Cytological diagnosis of ascites revealed adenocarcinoma. At autopsy, a whitish tumor measuring around 5 cm in diameter was found at the head of the pancreas. Metastasis was seen only in the liver. Histological examination displayed bizarre multinucleated giant cells occasionally phagocytosing the tumor cells and neutrophils.

Aged↗
PubMed1981

An organ culture method for glandular stomach of new born rat.

An organ culture system has been developed for he long-term maintenance of the glandular stomach of new born Wistar rats. The explants from glandular stomach were cultured on Millipore filter in an organ culture dish with various media consisting of sera, buffers and additives under different gas phases of oxygen, carbon dioxide and nitrogen at 37 or 24 degrees C. The culture condition was evaluated by histological examination of explants and was divided into Grade (+++), (++), (+) and (-) depending upon the morphology and growth of the mucosal epithelium. D-MEM plus fetal calf serum (20%) supplemented with hydrocortisone (10 microgram/ml) or dexamethasone (5 microgram/ml) buffered with sodium bicarbonate and Hepes under a gas phase of O2 (95%)+CO2(5%) or (2(45%)+CO2(5%)+N2(50%) at 37 degrees C showed the best result. Other supplements tested, such as insulin, ascorbic acid and ferrous sulfate were ineffective. Addition of hydrocortisone or dexamethasone was similarly effective in serum-free media. Isologous rat serum had no advantage over fetal calf serum. Transplantation and autoradiography revealed the viability of the explants up to 35 days in vitro.

Animals↗
PubMed1981

Studies on nitrosamine formation by the interaction between drugs and nitrite. I. Measurement of the amount of nitrosamine formed in rat and guinea pig stomachs.

The amounts of nitrosamine formed by the interaction of several drugs and nitrite in rat and guinea pig stomachs were estimated. The nitrosamine formation from aminopyrine and nitrite was much more in guinea pig stomachs than in rat stomachs. It seemed that this result was due to the difference in gastric contents of these animals. As the nitrosamine formation was also indicated in the interaction of a clinically prescribed dose of aminopyrine and very low doses of nitrite in rat and guinea pig stomachs, there is a possibility that the nitrosation of aminopyrine takes place in human stomachs, too. Minocycline also interacted with nitrite and formed N-nitrosodimethylamine. However, the amount of nitrosamine formed was less in minocycline than in aminopyrine. Oxytetracycline was not found to form nitrosamine in the stomachs of these animals. The effects of several compounds on the nitrosamine formation by the interaction of aminopyrine and nitrite were also investigated. Ascorbic acid, sodium erythorbate, propyl gallate and butylated hydroxyanisole reduced the nitrosamine formation but the effect of alpha tocopherol, sorbic acid and butylated hydroxytoluene was not observed in the stomach.

Aminopyrine↗
PubMed1981

Studies on nitrosamine formation by the interaction between drugs and nitrite. II. Hepatotoxicity by the simultaneous administration of several drugs and nitrite.

The alterations of biochemical parameters, namely, glutamic oxaloacetic transaminase and glutamic pyruvic transaminase in serum, hepatic microsomal drug oxidation systems, glucose-6-phosphate dehydrogenase and lysozomal enzymes in hepatic soluble fraction were investigated for the purpose of semiquantitatively estimating the hepatotoxicity caused by the interaction of several drugs and sodium nitrite in rats. The simultaneous administration of aminopyrine and sodium nitrite induced the alterations of these parameters. However, these alterations were not induced by the administration of antipyrine and sodium nitrite. Therefore the alterations were thought to be mainly due to N-nitrosodimethylamine formed. The administration of 0.4 mmole/kg of aminopyrine and 1.0 mmole/kg of sodium nitrite was thought to induce the alterations to almost the same extent as induced by 0.15 mmole/kg of N-nitrosodimethylamine. The simultaneous administrations of sodium nitrite and several other drugs with tertiary amino groups, namely oxytetracycline, diphenhydramine, oleandomycin, erythromycin and minocycline induced small alterations of these parameters. However, these alterations were not thought to relate to the hepatic injury induced by N-nitrosodimethylamine. Therefore the amount of N-nitrosodimethylamine formed from these drugs in rats was thought to be rather small. We also investigated the effect of several antioxidants on the alterations of biochemical parameters induced by aminopyrine and sodium nitrite. Ascorbic acid, sodium erythorbate and propyl gallate inhibited these alterations. On the other hand, sorbic acid did not.

Aminopyrine↗
PubMed1981

Manifestation of latent alpha-excitatory response in the canine tracheal smooth muscle preparation--relation to basal tone.

Alpha-adrenergic contractile response of the tracheal smooth muscle preparation isolated from young adult dogs was investigated. When the basal tone of the preparation was elevated by spasmogens, methacholine, K+, etc., in the presence of 1 microM propranolol, norepinephrine and phenylephrine caused contraction of the preparation. Isoproterenol did not. The contraction was specifically antagonized by phentolamine. The height of contraction caused by alpha-stimulants depended on the height of basal tone. The relationship of them was essentially the same whether methacholine on K+ was used as spasmogen, and if the Ca ion concentration in Krebs' solution was reduced to 0.1 mM. It was concluded that the tracheal smooth muscle of young adult dogs which is usually insensitive to alpha-stimulants responds to them when the basal tone is elevated by spasmogens, and it was suggested that an elevated intracellular free-Ca ion level contributed to this phenomenon.

Animals↗
PubMed1981

Transplantation of untreated glandular stomach of fetal and newborn rats and their malignant conversion.

Untreated fetal and newborn glandular stomachs of Wistar rats were transplanted into the subcutis, testis, peritoneal cavity and subcapsular spaces of the kidney or spleen of syngeneic adult rats. The recipients were sacrificed one year after transplantation. Transplantability was very high and the grafted tissues were recovered from more than 80% of the animals at almost all transplantation sites. The transplanted gastric mucosa was well-differentiated morphologically and biochemically. Malignant conversion occurred in 6 of 118 transplants (5%); the tumors were a fibrosarcoma (1), a ganglioneuroblastoma (1), leiomyosarcomas (2) and squamous cell carcinomas (2). No malignant transformation of glandular stomach epithelium was observed.

Animals↗
PubMed1980

High-performance aqueous gel permeation chromatography of human serum lipoproteins.

A new application of high-performance aqueous gel permeation chromatography was developed for the analysis of human serum lipoproteins. A good combination of columns (TSK GEL, type PW and type SW) was found for the separation of serum lipoproteins: very low-density lipoprotein, low-density lipoprotein and high-density lipoproteins. Analyses of serum lipoproteins from individual normal subjects and pathological subjects were performed by this combination of columns. The effects of pH and salt concentration fo the eluent on the separation of lipoproteins were also investigated.

Chromatography, High Pressure Liquid↗