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Biomedical subjects

D Burnett

Publications and source records attributed to D Burnett.

At least 199 records · Page 11Linked to original sources
PubMed1976

Estimation of the Stokes radii of serum proteins for a study of protein movement from blood to amniotic fluid.

The effective hydrodynamic (Stokes) radii of fifteen serum proteins were estimated by Sephadex G 200 gel filtration and immunochemical methods. The Waldmann-Meyer and Birch equation (Protides Biol. Fluids, Proc. 21st Colloq. (1974) (Peeters, H., ed.), Vol. 21, pp. 653-656, Pergamon Press, Oxford) was used for maximum accuracy. Three replicate column runs were made to assess the precision for the size determinations (coefficients of variation 0.6-2.7(). Quantive two-dimensional immunoelectrophoresis was used to measure eleven proteins in specimens of serum and amniotic fluid collected from twelve normal pregnancies. There was a close inverse linear relationship between the amniotic fluid/serum ratios of the proteins and their Stokes radii. This indicates that the movement of a protein from the blood to amniotic fluid is determined by the size of the protein. The linear correlation of protein amniotic fluid/serum ratio with Stokes radius was better than that with molecular weight. This demonstrates that, as an expression of protein size, Stokes radius should be used in preference to molecular weight when protein filtration systems are being investigated.

Amniotic Fluid↗
PubMed1976

Urinary excretion of methaqualone-N-oxide in man.

1. Oral administration of therapeutic doses (250 mg) of methaqualone (Melsed) to adult human subjects gives rise to the urinary excretion of methaqualone-N-oxide. This metabolite has been identified by chromatography and mass spectrometry and quantitatively determined by reduction with titanium trichloride to methaqualone which was then determined by g.l.c. 2. The N-oxide accounts for 5-9% of the dose in 24 h. 3. 2-Nitrobenzo-o-toluidide, a possible oxidation product of methaqualone-N-oxide, has not been detected. 4. The urinary excretion of unchanged methaqualone is less than 0-3% of the dose. The ease with which methaqualone-N-oxide is thermally converted to methaqualone casts doubts on the previously published figures for the urinary excretion of methaqualone.

Administration, Oral↗
PubMed1976

Urinary excretion of c-hydroxy derivatives of methaqualone in man.

1. Six monohydroxy metabolites of methaqualone have been identified by g.l.c.-mass spectrometry in the urine of healthy human subjects who received therapeutic doses (250 mg) of the drug (Melsed) daily for ten day. 2. The three major metabolites were 2-methyl-3-(2'-hydroxymethylphenyl)-4(3H)-quinazolinone, 2-methyl-3-(2'-methyl-3'-hydroxyphenyl)-4(3H)-quinazolinone and 2-methyl-3-(2'-methyl-4'-hydroxyphenyl)-4(3H)-quinazolinone. Three minor metabolites in descending order of importance were 2-hydroxymethyl-3-o-tolyl-4(3H)-quinazolinone, 2-methyl-6-hydroxy-3-o-tolyl-4(3H)-quinazolinone and 2-methyl-8-hydroxy-3-o-tolyl-4(3H)-quinazolinone. 3. The 8-hydroxy metabolite is identified as a urinary metabolite or methaqualone in humans for the first time.

Administration, Oral↗
PubMed1976

Selectivity of proteinuria during pregnancy assessed by different methods.

Relative protein clearance measurements have gone a long way toward characterizing the nature of pregnancy proteinuria but have failed to distinguish between preeclampsia and primary renal disease. The prognostic significance of different degrees of selectivity has been a source of disagreement in past studies. The polymer clearance studies reported here, using tracer doses of labeled PVP, have demonstrated two forms of proteinuria: a benign form due to a vasoconstrictor effect where fetal outlook is good ("vasoactive"), and a form associated with intravascular coagulation which indicates worse fetal prognosis ("membranous"). Underlying chronic renal damage of minor degree is identifiable with PVP clearance. Concurrent measurements of protein clearance, using smaller-sized proteins than is customary, gave hope for future development of meaningful clinical tests.

Female↗
PubMed1974

Assessment of coagulation and fibrinolysis in pre-eclampsia.

A method is described for distinguishing coagulation from fibrinolysis by three estimates of fibrinogen. This "fibrinogen series" together with plasma antithrombin and urinary urokinase have been compared in pregnant patients with venous thrombosis and pre-eclampsia. Evidence is presented for active coagulation during deterioration of the pre-eclampsia state and for enhanced fibrinolysis during improvement.

Adult↗