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D Hayes

Publications and source records attributed to D Hayes.

131 records · Page 8Linked to original sources
PubMedDate not supplied

IUPAC collaborative trial study of a method to detect genetically modified soy beans and maize in dried powder.

This paper presents results of a collaborative trial study (IUPAC project No. 650/93/97) involving 29 laboratories in 13 countries applying a method for detecting genetically modified organisms (GMOs) in food. The method is based on using the polymerase chain reaction to determine the 35S promotor and the NOS terminator for detection of GMOs. reference materials were produced that were derived from genetically modified soy beans and maize. Correct identification of samples containing 2% GMOs is achievable for both soy beans and maize. For samples containing 0.5% genetically modified soy beans, analysis of the 35S promotor resulted also in a 100% correct classification. However, 3 false-negative results (out of 105 samples analyzed) were reported for analysis of the NOS terminator, which is due to the lower sensitivity of this method. Because of the bigger genomic DNA of maize, the probability of encountering false-negative results for samples containing 0.5% GMOs is greater for maize than for soy beans. For blank samples (0% GMO), only 2 false-positive results for soy beans and one for maize were reported. These results appeared as very weak signals and were most probably due to contamination of laboratory equipment.

Agrobacterium tumefaciens↗
PubMedDate not supplied

Comparative physiological disposition of ellipticine in several animal species after intravenous administration.

The physiological dispositon of ellipticine (NSC 71795) has been studied in the mouse, rat, dog and monkey after administration of [1-14C]ellipticine at 6 mg/kg iv (3 mg/kg to monkey). Ellipticine was very rapidly distributed from the blood of all species and was deposited in tissues. The rate of elimination of ellipticine from blood was species-dependent, half-times ranging from 22 min in mouse to 210 min in rat, and probably reflected the rate of metabolism of the drug. The rate of elimination of metabolites from blood was also species-dependent, half-times ranging from 140 min in mouse to 380 min in rat, and probably reflected the rate of biliary secretion of the metabolites. Ellipticine was widely but not uniformly distributed throughout the tissues including brain, and some of the highest concentrations of drug and metabolites were in liver, which is probably the primary site of metabolism. The concentrations of ellipticine and metabolites in tissues were species-dependent, correlating with species differences in rates of metabolism and excretion. All species excreted 80% of the dose via the fecal route and 10% via the urinary route, primarily as metabolites during the first 24 hr after dosing. Metabolites entered the gastrointestinal tract by biliary secretion and ellipticine entered by an ion-trapping mechanism. Evidence is presented that the major pathway for ellipticine metabolism in rat was to 9-hydroxyellipticine, which did not accumulate in liver but was conjugated to its glucuronide and sulfate, which were secreted in bile. Other pathways involved hydroxylation and glucuronide conjugation. The pharmacokinetics of ellipticine are correlated with its toxic side effects, such as acute hypotention and neurological symptoms. They are also correlated with its potential as an antitumor agent, such as its ability to achieve values for the area under the curve of concentration vs. time (CXt) in tumors, which would be adequate for therapy. Based upon these correlations, the drug should be administered in the clinic by iv infusion, or, provided its bioavailability is found to be satisfactory, by the oral route.

Alkaloids↗
PubMedDate not supplied

Race and survival from breast cancer: based on Cancer and Leukemia Group B trial 8541.

PURPOSE: The purpose of this research was to evaluate the prognostic significance of race and survival in stage II breast cancer among women treated with adjuvant chemotherapy in the Cancer and Leukemia Group B (CALGB) trial 8541. MATERIALS AND METHODS: A total of 1572 patients with node-positive breast cancer were entered in CALGB trial 8541. This study opened in January 1985 and randomized patients to receive "high-dose," "standard-dose," or "low-dose" adjuvant CAF (cyclophosphamide, doxorubicin, and fluorouracil) chemotherapy. Patients were stratified according to treatment of the primary lesion (mastectomy or breast conservation), menopausal status, number of positive lymph nodes, and estrogen-receptor status. Twelve percent of the patients entered in this study were African-American, 84% were white, and 4% were of other racial backgrounds. RESULTS: African-Americans and whites were evenly distributed on all three arms. In a univariate analysis, African-Americans were more likely to have a reduced survival and shorter time to relapse than other patients. Race was moderately associated with tumor size, receptor status, and type of surgery. In a multivariate analysis, after adjusting for the dose of chemotherapy, number of lymph nodes, estrogen-receptor status, and age, race was no longer of prognostic significance. DISCUSSION: After adjustment for other well-recognized prognostic factors, race appears to have no independent prognostic significance for survival from stage II breast cancer among women receiving adjuvant CAF chemotherapy.

Black People↗