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Biomedical subjects

D Burnett

Publications and source records attributed to D Burnett.

At least 181 records · Page 10Linked to original sources
PubMed1979

The metabolism of methaqualone in patients with biliary cirrhosis or secondary carcinoma of the liver.

The metabolism of methaqualone has been studied in three patients with secondary carcinoma of the liver and two with biliary cirrhosis. The urinary excretion of five C-monohydroxy metabolites and the N-oxide was studies in the 24 h period immediately after oral dosing with 250 mg methaqualone (Melsed). In both patients with biliary cirrhosis and one with primary carcinoma of the bile duct or pancreas with secondaries in the liver the pattern of metabolites was normal. In a patient with oat cell carcinoma with secondaries in the liver some metabolite patterns were disturbed and increased metabolite excretion occurred. A patient with primary carcinoma of the breast with secondaries in the liver gave a completely abnormal metabolite pattern.

Adult↗
PubMed1979

Tumour markers in breast cancer.

The clinical usefulness of 8 potential tumour markers has been evaluated in 69 patients with Stage I and II breast cancer and 57 patients with Stage III and IV. Serum CEA concentrations were raised in 13% of patients with local and 65% of those with advanced breast cancer. In patients with clinical evidence of progression or regression of tumour, serum CEA levels changed appropriately in 83% of cases. Taking 4 of the markers (carcinoembryonic antigen (CEA), lactalbumin, alpha subunit and haptoglobin) serum concentrations of one or more were raised in 33% of patients with local disease and 81% of those with advanced breast cancer. However, marker concentrations were often only marginally raised, and are unlikely to provide sensitive guide to tumour burden. CEA, lactalbumin and alpha subunit were detectable in 68%, 43% and 40% respectively of extracts of primary breast cancers.

Breast Neoplasms↗
PubMed1979

A study of plasma proteins in the sol phase of sputum from patients with chronic bronchitis.

We have studied the sputum/serum protein concentration ratios from 23 patients with bronchitis both in the stable clinical state and during acute chest infections. During the stable state there was a significant negative correlation (2 P less than 0.005) between the ratio and protein size. The ratios of IgG, IgA, C3, and alpha 1-antichymotrypsin were significantly displaced from this relation suggesting local production in the lung. IgM was found in all samples and alpha 2-macroglobulin in 55% of non-infected samples which may be the result of local production rather than transudation from serum, because of their larger size. During acute chest infections the albumin content of sputum rose from a mean sputum/serum ratio of 0.83 (SE +/- 0.08) X 10(-2) to 13.77 (SE +/- 3.21 X 10(-2) suggesting increased transudation from the blood. In the presence of increased transudation, local production of protein appears to be less significant.

Aged↗
PubMed1979

Alpha,-antitrypsin and leukocyte elastase in infected and noninfected sputum.

Leukocyte elastase and alpha 1-antitrypsin have been implicated in the pathogenesis of pulmonary emphysema. The relationship between these proteins has been studied in sputum both qualitatively and quantitatively in bronchitic patients with and without chest infections. Leukocyte elastase was found in 75% of the noninfected samples but was enzymatically inactive, suggesting complete inhibition. During infection, leukocyte elastase and alpha 1-antitrypsin concentrations increased, although the enzyme was only partially inactivated. The proportion of alpha 1-antitrypsin present as "complex" was smaller in the presence of infection, suggesting damage of the protein by excess enzyme.

Bronchitis↗
PubMed1978

The effect of the protein content of diluents on peak height in rocket immunoelectrophoresis.

We have investigated the effect of different diluents in the quantitation of proteins by rocket immunoelectrophoresis. alpha2-Macroglobulin produced taller peaks as the protein content of the diluent fell to zero, and the dilution was increased. A maximum increase in height of 25-30% was recorded when saline was used as the diluent compared to a sample diluted in sheep serum. Albumin and transferrin showed similar, but less significant effects. Samples and standards should therefore contain approximately equal concentrations of protein for maximum accuracy.

Humans↗
PubMed1978

An arterio-venous study of serum alpha1-antitrypsin in patients with chronic bronchitis.

The effect of passage through the lung on alpha1-antitrypsin was studied in sixteen patients with chronic obstructive airways disease. The average mixed venous value of alpha1-antitrypsin (106.2% standard serum value) was not different from the the mean arterial value (105.6%). Where individual differences were found there was a similar difference in serum albumin. However, there was a small but significant rise (p less than 0.005) in serum alpha1-antitrypsin "complex" as blood traversed the lung (mixed value = 6.3%; mixed arterial value = 6.8%). The reason is not yet clear.

Arteries↗
PubMed1978

Metabolism of methaqualone in geriatric patients.

The urinary excretion of five C-monohydroxy metabolites and the N-oxide of methaqualone has been measured in a group of eleven geriatric patients aged 71--90 years. The total excretion of the six metabolites in 24 h after the oral administration of a single dose was approximately one-half of that in a group of young healthy adults. The relative importance of the six metabolites was 4'-hydroxy greater than N-oxide greater than 2'-hydroxymethyl = 3'-hydroxy greater than 6-hydroxy = 2-hydroxymethyl which was the same order as that in young adults. The ratio of C-to N-oxidation was also the same in the two groups. There was no impairment of conjugation of the C-hydroxy metabolites with glucuronic acid in the geriatric group but there was greater interindividual variation in metabolite excretion. There was also evidence for delayed metabolism in the geriatric patients.

Aged↗
PubMed1978

Inter- and intra-individual variation in the metabolism of methaqualone in man after a single oral dose.

The urinary excretion of five C-monohydroxy metabolites and the N-oxide metabolite of methaqualone in the 24 h period immediately after oral dosing with 250 mg methaqualone (Melsed) has been measured in ninteen healthy adults (13 male, 6 female) to assess interindividual variations and in five adults (3 male, 2 female) on five separate occasions to assess intraindividual variation. The overall importance of the six metabolites was 4'-hydroxy greater than N-oxide greater than 2'-hydroxymethyl greater than 3'-hydroxy greater than 6-hydroxy = 2-hydroxymethyl. Variations in this order both within the 24 h period and within each of the three eight-hour periods constituting the 24 hours were minor and variations in the absolute amount of each metabolie excreted ranged from two to three-fold. Intraindividual variations were generally smaller than interindividual variations and for each individual the pattern of metabolism was similar on the five occasions. There is evidence that the C-oxidation of methaqualone may be more sensitive to cyclical variations in hormone levels than is N-oxidation.

Adult↗
PubMed1977

Quality control in the simultaneous assay of anticonvulsants using an automated gas chromatographic system with a nitrogen detector.

An automated gas-liquid chromatographic technique for the routine determination of phenobarbitone, primidone and phenytoin using a nitrogen-detector is described. The high selectivity of the detector for nitrogen-containing compounds allows a direct extraction procedure and the use of a phenytoin analogue as an internal standard obviates the need for accurate aliquot measurement after extraction. The anticonvulsants are chromatographed as methyl derivatives produced by on-column methylation with trimethylphenyl ammonium hydroxide following automatic liquid injection. Quality control data from an internal quality control scheme is presented and the performance of the laboratory in an inter-laboratory control scheme is reported and discussed.

Anticonvulsants↗
PubMed1977

Cancer-associated proteins in effusion fluids.

Two cancer-associated proteins, carcinoembryonic antigen (CEA) and pregnancy-associated alpha2 glycoprotein (PAG), together with 13 normal serum proteins were measured in the serum and effusion fluid of patients with ascites and pleural effusions. The results indicate that CEA measurement in effusion fluid is more effective than serum measurement in distinguishing cancerous from congestive or inflammatory effusions. Comparisons with the results of cytological examination suggest that fluid CEA estimation may prove a useful clinical tool. Serum PAG levels were higher in patients with cancer, but fluid determination offers no advantage in separating the disease groups. Similarly, the estimation of individual normal serum proteins in effusion fluids is unlikely to be of diagnostic value.

Ascitic Fluid↗
PubMed1977

Filtration leukapheresis: effects of donor stimulation with dexamethasone.

Dexamethasone was administered to 51 donors prior to filtration leukapheresis. The results of this maneuver, including the consequences of transfusion, were contrasted with results in 52 donors who did not receive the steroid. Yields of polymorphonuclear leukocytes, the posttransfusion increments in recipients, themorphologic polymorphonuclear leukocytes obtained, and the incidence of donor and recipient reactions were all beneficially influenced by this manipulation. Possible mechanisms responsible for these observations are discussed. It is recommended that dexamethasone stimulation be used in filtration leukapheresis when circumstances do not otherwise contraindicate such a maneuver.

Blood Donors↗
PubMed1976

Pregnancy associated alpha2-glycoprotein in post-menopausal women receiving hormone replacement therapy.

Serum pregnancy associated alpha2-glycoprotein (P.A.G.) concentrations were measured in a group of post-menopausal women receiving hormone replacement therapy. The P.A.G. concentrations increased from a mean basal level of 48.1 mug/ml (range 20.6--104.4 mug/ml) to a maximum after six months therapy of 359 mug/ml (range 82--1290 mug/ml). This represents a mean increase of 647%. Two months after cessation of therapy the P.A.G. concentrations decreased but the mean level (60.3 mug/ml) was still significantly higher than the pre-treatment level. There was a significant correlation between the pre-treatment P.A.G. concentrations and the levels after six months of therapy. These findings may be of relevance to the use of P.A.G. determinations in the monitoring of malignant disease.

Adult↗