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Biomedical subjects

J E Buttery

Publications and source records attributed to J E Buttery.

At least 73 records · Page 4Linked to original sources
PubMed1977

Determination of ethanol in serum by an enzymatic PMS-INT colorimetric method.

A simple, rapid and accurate colorimetric method for the determination of ethanol in serum was studied. Ethanol is converted to acetaldehyde by alcohol dehydrogenase, and the NADH formed transfers its hydrogen through the phenazine methosulphate-p-iodonitrotetrazolium violet (PMS-INT) system to produce the red formazan which is stable and absorbs at 505 nm. The method correlates very well with an enzymatic-UV method, r=0.98 (p less than 0.001). The precision (95% limits) of the method for samples ranging from 11 to 145 mg/dl was +/-6.6%, and the recovery averaged 99%.

Colorimetry↗
PubMed1976

The use of NADH as a standard in a modified PMS-INT colorimetric assay of lactate dehydrogenase.

A new and more reliable way of quantitating lactate dehydrogenase activity, using NADH as a standard in a colorimetric assay, is proposed. Adopting the scheme, we obtained a CV of 2.6% and precision (95% limits) of +/-5.4% for enzyme activities ranging from 110 to 600 U/l. Comparative study against the modified kinetic method of Amador et al. showed excellent correlation, r = 0.99, p less than 0.001. A normal range of 75 to 203 U/l was determined for the proposed scheme.

Colorimetry↗
PubMed1975

Catecholamines in urine; an evaluation of alumina-trihydroxyindole methods and a description of an improved method.

A critical assessment of the accuracy and practicability of five alumina-trihydroxyindole methods for the estimation of urinary catecholamines, including our proposed method, was undertaken. The recovery of noradrenaline added to urine obtained by these methods was quantitated against different types of standards, and varied from 22.9 per cent to 104.8 per cent. The major analytical problems (fluorescence suppression and loss of catecholamines during column chromatography) were evaluated and related to the recovery of the respective procedures. The improved method we developed is simple, rapid and reliable. The low fluorescence suppression and column losses of noradrenaline of this method, averaging 2.9 per cent and 5.3 per cent, respectively, resulted in a mean recovery of 92.0 per cent against an external standard. Both the chromatography step and fluorescence development are simple and short, and a batch of ten cases can be completed within 3 hours.

Aluminum↗