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Biomedical subjects

K Takamura

Publications and source records attributed to K Takamura.

At least 73 records · Page 4Linked to original sources
PubMed1984

Differential pulse polarographic determination of plasma menadione.

A differential pulse polarographic assay for plasma vitamin K3 (menadione) has been developed. Details of the assay are (i) lipid-soluble material is extracted from plasma into ether by the method of Bjornsson et al. [(1978) Thromb. Haemostas. 2, 466-473]; (ii) ether is evaporated under nitrogen and the residue is dissolved in the supporting electrolyte, methanol: 0.2 M borate buffer (9:1), pH 6.8; (iii) current height is measured at -0.32 V vs SCE on the differential pulse polarogram. The lower sensitivity limit of this technique after addition of standard vitamin K3 to plasma is 0.3 microM; the calibration curve is linear from 0.6 through 10 microM. Two patients treated with a single dose of menadiol sodium diphosphate, 20 mg/M2 i.m., achieved measurable plasma vitamin K3 levels at 0.5 to 1.0 h ranging between 0.5 (0.08 micrograms/ml) and 2 microM (0.3 micrograms/ml).

Humans↗
PubMed1983

A spectrophotometric method for the determination of free fatty acid in serum using acyl-coenzyme A synthetase and acyl-coenzyme A oxidase.

A mixture of Ti(IV) and 4-(2-pyridylazo)resorcinol was found to be useful in the spectrophotometric determination of trace amounts of hydrogen peroxide. The absorbance at 508 nm was proportional to the concentration of hydrogen peroxide added. The reagent was successfully applied to the assay of free fatty acid in serum through the combined use of acyl-CoA synthetase and acyl-CoA oxidase. The latter enzyme produces H2O2. As a result, hydrogen peroxide was produced through the enzymatic oxidation of free fatty acid. It was possible to determine free fatty acid in 50 microliters of serum at concentrations ranging from 0.02 to 1.5 mM. The coefficient of variation was less than 3% at concentrations ranging from 0.1 to 1.5 mM. In the present method, there is the advantage of minimal influence from reducible substances as well as greater simplicity and accuracy.

Acyl-CoA Oxidase↗