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Biomedical subjects

T Oikawa

Publications and source records attributed to T Oikawa.

At least 343 records · Page 19Linked to original sources
PubMed1977

A simple colorimetric method for determination of serum triglycerides with lipoprotein lipase and glycerol dehydrogenase.

A simplified enzymic procedure to determine accurately serum triglycerides is described. Serum triglycerides are hydrolyzed completely to free fatty acids and glycerol by lipoprotein lipase from Pseudomonas fluorescens. The released glycerol is oxidized with glycerol dehydrogenase from Erwinia aroideae in the presence of NAD+, were the reduction of the enzyme-linked NAD+ is coupled to the reduction of nitro blue tetrazolium as a chromogenic indicator with phenazine methosulfate serving as an intermediate electron carrier of NADH. The absorbance at 570 nm is measured. The method requies only 20 microliter of serum and a 10-min incubation and is rapid and simple. The present method offers the measurement of a high concentration of triglyceride up to 1000 mg/dl serum. The results obtained by the present method show good correlation with those obtained by the glycerol kinase method (correlation coefficient, 0.989) or the acetylacetone method (correlation coefficient, 0.979). These results suggest that the proposed method will be utilized as a method or routine clinical test.

Colorimetry↗
PubMed1977

Physicochemical properties of a lipase from Pseudomonas fluorescens.

The molecular weight of traicylglycerol lipase (EC 3.1.1.3) from Pseudomonas fluorescens is estimated to be approx. 33 000 by sodium dodecyl sulfate electrophoresis and Sephadex G-75 gel filtration. The lipase appears to be a single-chain protein and contains neither sugar nor lipid. The enzyme has a sedimentation coefficient (S20,w) of 3.06, an intrinsic viscosity of 3.0 g/ml and a partial specific volume of 0.730 g/ml, with an isoelectric point of pH 4.46. Amino acid analysis showed that the enzyme contained few sulfur-containing amino acid residues with no disulfide links. The N-terminal residue of the enzyme was found to be alanine and optical rotation dispersion analysis showed that about 20% of the enzyme structure was in a helicla configuration.

Amino Acids↗
PubMed1977

Purification, crystallization and properties of triacylglycerol lipase from Pseudomonas fluorescens.

Triacylglycerol lipase of Pseudomonas fluorescens was purified from the crude enzyme by ammonium sulfate precipitation and chromatographies on Sephadex G-75 and DEAE-cellulose. The crystallization of the lipase was successfully carried out. The purified lipase was demonstrated to be homogenous on disc electrophoresis and its molecular weight was calculated to be 32 000 by gel filtration. The optimum pH for hydrolysis of sesame oil was 7.0. The enzyme was stable up to 40 degrees C under the condition of pH 7.0 for 30 min and had more than 80% of the remaining activity between pH 5.0--11.0 at 37 degrees C for 60 min. The lipase was strongly inhibited by iodine and partially inhibited by FeCl3 and N-bromosuccinimide, and showed the most activity on tricaproyglycerol, among the triacylglycerols used.

Crystallization↗
PubMed1977

Anti-tumour immunity by normal allogeneic blood transfusion in rat.

Growth of transplantable KMT-17 tumour in syngeneic WKA/MK rats was inhibited by i.v. preimmunization with whole blood from normal rats of allogeneic strains. The inhibitory effect was also observed in rats immunized with allogeneic white blood cells alone. The strength of the inhibitory effect mainly depended on the the strain of donor rat used; blood from Donryu and Kyoto strain rats produced the strongest inhibition, blood from Tokyo and Fischer strain rats produced moderate inhibition to the syngeneic tumour growth. Blood from ACI/N strain rats did not produce the inhibition. The mechanism of blood transfusion in inhibiting tumour growth is not yet clear. However, it seems that GVH reaction does not play an important role in the mechanism of the inhibition effect, because the effect was obtained by immunization with mitomycin C-treated allogeneic white blood cells and also by the immunization effect may be due to nonspecific active immunization. Significance of blood transfusion with special reference to clinical immunogtherapy of cancer is discussed.

Animals↗
PubMed1976

Inhibition of syngeneic tumor growth in rats immunized with allogeneic skin grafts.

The growth of a transplantable tumor (KMT-17) in syngeneic Wistar King Aptekman/Mk (WKA) rats was inhibited by preimmunization with allogeneic normal cells from Donryu strain rats. The phenomenon is referred to as allogeneic cell immunity. A slight inhibition was observed in rats immunized with normal liver, spleen, kidney, embryonal cells, whole blood and white blood cells from allogeneic Donryu rats. A strong inhibition was observed in animals which had rejected allogeneic skin grafts, particularly from the Donryu and Kyoto rats. The inhibition was comparatively weak after immunization with skin grafts from the Long Evans, ACI, Buffalo, Ficsher, Sprague Dawley or Tokyo allogeneic rat strains. This immunizing effect was dependent on the viability of the grafts and was easily abrogated by low-dose irradiation. The mechanism of allogeneic cell immunity is considered to be a non-specific stimulation of the immunity against antigenic tumors in the syngeneic host

Animals↗
PubMed1976

Regional cerebral blood flow in focal cortical epilepsy.

Regional cerebral blood flow (rCBF) was studied in ten patients with focal cortical epilepsy. The blood flow was measured by the intra-arterial injection of xenon 133 (133Xe), and the isotope clearance was recorded by a multidetector scintillation camera with 254 detectors. Three patients were studied both during a seizure and (in the same setting) in the interictal period; six patients were studied only in the interictal period, and one patient was studied only during a seizure. Studies during seizures all showed marked flow increases in areas presumed to participate in the seizure activity. This finding accords with earlier studies. All nine patients studied in the interictal phase showed, either spontaneously or during activation by intermittent light, focal flow increases in areas presumed to comprise the epileptic focus. These interictal hyperemic foci probably reflect subictal neuronal hyperactivity in epileptogenic nervous tissue. Only two of the patients had distinct epileptic electroencephalographic foci. It appears that rCBF studies can be a valuable diagnostic tool in the investigation of cortical epileptogenic lesions.

Adult↗