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Biomedical subjects

V WYNN

Publications and source records attributed to V WYNN.

At least 19 recordsLinked to original sources
PubMed1962

Blood pyruvate concentration measured by a specific method in control subjects.

A specific method of estimating pyruvate, depending upon the oxidation of reduced nicotinamide-adenine dinucleotide in the presence of lactic dehydrogenase, has been modified to improve its accuracy. The precision of the modification, measured by duplicate analysis, was represented by a standard deviation of 0.03 mg./100 ml. The mean recovery of added pyruvate was 99%. The mean blood pyruvate concentration in 30 fasted subjects, who had no illness known to affect pyruvate metabolism, was 0.44 mg./100 ml. (S.D. 0.05). Blood pyruvate levels were measured at 30-minute intervals for two hours after oral or intravenous administration of glucose. The highest levels obtained in each case were about 0.4 mg./100 ml. higher than the initial level, and were found 60 to 90 minutes after oral administration and 30 to 60 minutes after intravenous administration.

Fasting↗
PubMed1961

The determination of magnesium in biological materials by flame photometry.

A method is described for the measurement of magnesium in biological materials and has been applied to the Unicam flame spectrophotometer SP 900. Samples were diluted in 10 mM strontium ethylenedinitrolo tetraacetate (EDTASr), 10 mM potassium carbonate, giving final magnesium concentrations of about 0.1 to 0.2 mM. The EDTASr almost eliminated the depression of magnesium emission by interfering anions. The potassium carbonate slightly depressed both magnesium emission and flame background, which were then virtually unaffected by further addition of cations. Spectral interference by sodium was controlled by including 14 mM sodium chloride in the plasma standards and making small corrections (usually under 2%) on the basis of the plasma sodium level. The urine standards contained no sodium, but a small correction (usually about 2%) was made on the basis of the urine sodium level. There was insufficient sodium in faeces to cause spectral interference. Using the diluent described, added magnesium was satisfactorily recovered from plasma deproteinized with perchloric acid, urine, and faeces. When different volumes of identical samples of plasma and urine were analysed, the magnesium found was proportional to the volume of sample diluted. The plasma magnesium levels reported for a small group of healthy people were similar to those found by previous workers.

Carbonates↗