Biomedical subjects

K Brewster

Publications and source records attributed to K Brewster.

14 recordsLinked to original sources

PubMed2005

Psychological functioning in African American women at an increased risk of hereditary breast and ovarian cancer.

Despite attention to psychological issues during genetic counselling and testing for hereditary breast and ovarian cancer risk, limited information is available on cancer-specific distress among African American women being targeted for participation in counselling and testing. Therefore, the purpose of this study is to examine cancer-specific distress in African American women at an increased risk of hereditary breast and ovarian cancer and to identify factors having significant associations with distress in this population. Respondents were 141 African American women identified for participation in genetic counselling and testing for BRCA1/2 mutations. Overall, respondents reported moderate levels of cancer-specific distress. Younger age (coefficient=6.0, p=0.001), being unemployed (coefficient=-5.0, p=0.01), and having a personal history of cancer (coefficient=5.0, p=0.02) had significant associations with intrusion. Younger age was also associated significantly with greater avoidance (r=6.0, p=0.02). These results suggest that African American women aged 50 and younger, those who are unemployed and women with a personal history of breast or ovarian cancer may be the most vulnerable to experiencing elevated levels of distress during genetic counselling and testing. Greater attention to psychological issues, including concerns about cancer and cancer risks, may be needed during genetic counselling and testing for BRCA1/2 mutations with these women.

Adult↗

PubMed1993

Metabolism of thiodiglycol (2,2'-thiobis-ethanol): isolation and identification of urinary metabolites following intraperitoneal administration to rat.

1. The metabolism of thiodiglycol, 2,2'-thiobis-ethanol, was investigated following i.p. administration to rat. 2. Approximately 90% of the administered dose was excreted in the 0-24-h urine. Four metabolites were isolated by h.p.l.c. and identified by mass spectrometry. Structural assignments were confirmed by comparison with authentic synthetic standards. 3. Thiodiglycol sulphoxide was the major metabolite accounting for approximately > or = 90% of the excreted radioactivity following i.p. injection of 13C4, 35S-thiodiglycol. Thiodiglycol sulphone, S-(2-hydroxyethylthio)acetic acid and S-(2-hydroxy-ethylsulphinyl)acetic acid were identified as minor metabolites. 4. Analysis for thiodiglycol by GC-MS indicated approximately 0.5-1% of the applied dose was excreted unmetabolized.

Animals↗

PubMed1992

Biological fate of sulphur mustard, 1,1'-thiobis(2-chloroethane): isolation and identification of urinary metabolites following intraperitoneal administration to rat.

1. The metabolism of sulphur mustard, 1,1'-thiobis(2-chloroethane), in vivo was investigated following i.p. administration to rat. 2. Approx. 60% of dose was excreted in the 24 h urine. Many metabolites were present; nine have been isolated by h.p.l.c. and characterized by mass spectrometry. Structural assignments were confirmed by comparison with authentic synthetic standards. 3. Some metabolites result from initial hydrolysis of the sulphur mustard, but the majority are formed by conjugation with glutathione. These are further metabolized to N-acetylcysteine conjugates, or to methylthio/methylysulphinyl derivatives by a pathway probably involving beta-lyase, accompanied by oxidation of the mustard sulphur atom to sulphoxide or sulphone. 4. Thiodiglycol sulphoxide, 1,1'-sulphonylbis[2-S(N-acetylcysteinyl)ethane] and 1,1'-sulphonylbis[2-methylsulphinyl)ethane] or 1-methylsulphinyl-2-[2-(methylthio ethylsulphonyl]ethane were the most prevalent metabolites resulting from the three major pathways. Metabolic pathways for the formation of the excretion products are proposed.

Animals↗

PubMed1987

The fate of 2-chlorobenzylidene malononitrile (CS) in rats.

1. The fate of 3H-ring labelled, 14C-cyanide labelled and (14C = C) side chain labelled 2-chlorobenzylidene malononitrile (CS), 2-chlorobenzyl alcohol and 2-chlorobenzyl malononitrile (dihydro CS) in rats and isolated rat liver cells has been examined. 2. CS was administered both i.v. and i.g. to rats at doses from 0.08 to 159 mumol/kg and in most cases the greatest proportion of the dose was eliminated in the urine (44-100%). The principal urinary metabolites were 2-chlorohippuric acid, 1-O-(2-chlorobenzyl) glucuronic acid, 2-chlorobenzyl cysteine and 2-chlorobenzoic acid. Lesser amounts of 2-chlorophenyl acetyl glycine, 2-chlorobenzyl alcohol and 2-chlorophenyl 2-cyano propionate were identified. 3. The major urinary metabolite from 2-chlorobenzyl alcohol was 2-chlorohippuric acid (43%), 2-chlorobenzyl cysteine, 2-chlorobenzoic acid and 2-chlorobenzyl glucuronic acid were identified. 4. The products of dihydro-CS metabolism were 2-chlorophenyl acetyl glycine, 2-chlorophenyl 2-cyanopropionate and 2-chlorophenyl proprionamide. 5. Urinary thiocyanate levels increased with the dose of CS up to 159 mumol/kg. At 212 mumol/kg there was a large increase in the amount of thiocyanate produced (molar conversion: 21.5-29.9%). Similarly malononitrile, the hydrolysis product of CS, gave a dose related increase in urinary thiocyanate levels. However at a higher dose (212 mumol/kg) the molar conversion was greater than 60%. 6. The metabolism of CS by isolated rat liver cells confirmed the results in vivo but demonstrated a marked limitation of this preparation to form conjugates. 7. It is concluded that CS in vivo is hydrolysed mainly to 2-chlorobenzaldehyde which is then either oxidized to 2-chlorobenzoic acid for subsequent glycine conjugation, or reduced to 2-chlorobenzyl alcohol for ultimate excretion as 2-chlorobenzyl acetyl cysteine or 1-O-(2-chlorobenzyl) glucuronic acid. Malononitrile is converted to thiocyanate via the formation of cyanide.

Animals↗

PubMed1980

Is the dream of a voluntary society still possible? The 1980 Harvey Cushing oration.

The United States Ambassador to the Court of St. James reviews the historic search for a society which is as voluntary as possible for the greatest number of citizens. Under the rule of law, there must continue to exist freedom of choice, freshness of start and opportunity, and the promise of mobility. The citizenry should not become dependent upon public administrators or political masters. Growth and expansion should not be constrained beyond reasonable limits, and openness of opportunity must be given high priority. The variety of State and private educational resources should be tapped for the design of educational communication programs.

Democracy↗

PubMed1980