Biomedical subjects

M E Doyle

Publications and source records attributed to M E Doyle.

27 records · Page 2Linked to original sources

PubMed1991

Risks of consumption of contaminated seafood: the Quincy Bay case study.

A recent EPA-sponsored study of sediment and seafood contamination in Quincy Bay revealed elevated levels of several complex organic pollutants frequently of concern in human health assessments. A seafood consumption risk assessment was conducted using data from samples collected in Quincy Bay in the methodology developed for EPA's Office of Marine and Estuarine Protection for such assessments. Results showed estimated plausible, upperbound excess cancer risks in the 10(-5) to 10(-2) range. These results are comparable to those found in other seafood contamination risk assessments for areas where consumption advisories and fishing restrictions were implemented. Regulatory response included consumption advisories for lobster tomalley (hepatopancreas) and other types of locally caught seafood. Uncertainties inherent in seafood risk assessment in general and for the Quincy Bay case are discussed, along with implications for further action.

Animals↗

PubMed1987

A randomized controlled evaluation of an educational program in adults with high psychosocial risk of morbidity.

This clinical trial tested the efficacy of a psychosocial intervention in a panel of white adults with a high level of recent stressful life changes and weak social supports. One hundred seventy users of three family practices were randomly assigned to receive a six-month educational program provided by a nurse practitioner or to a control group. Outcome variables were assessed over a 12-month follow-up period by mailed questionnaires and validated when possible by review of medical records. During the six months immediately following the intervention, recipients had a lower rate of restricted-activity days than controls. During the follow-up period, symptom experience, physical function, social function, and emotional function were similar in the two groups. While the overall improvement in social supports was not significantly better at the completion of the intervention for recipients than for controls, those recipients who developed strong supports had fewer restricted-activity days than those who continued to have weak supports. This educational program may provide temporary benefit to adults with high psychosocial risk for health impairment.

Adult↗

PubMed1980

Relationships between cytokinin production, presence of plasmids, and fasciation caused by strains of Corynebacterium fascians.

Cytokinin activity in the culture medium of four pathogenic strains of Corynebacterium fascians varied from 168 to 0.4 mug of kinetin (6-furfurylaminopurine) equivalents per liter, as compared to 0.2 in an avirulent control. N(6)-Isopentenyladenine was the predominant cytokinin in the medium of all five strains, and its increased production was correlated with the degree of pathogenicity; however, the virulent strains also produced 8-13 times more cis-zeatin [6-(4-hydroxy-3-methyl-cis-2-butenylamino)purine] than the avirulent strain. The three most virulent strains (with the higher cytokinin contents in the medium) contained a large (M(r) approximately 10(8)) plasmid. The barely virulent strain contained a smaller plasmid. No plasmid was detected in the avirulent control. The total cytokinin content (mole%) and biological activity (mug of kinetin equivalent per mg of tRNA) in tRNA were about the same in all three virulent strains and in the avirulent control. Five cytokinins were isolated from each strain. Four were rigorously characterized as 6-(4-hydroxy-3-methyl-cis-2-butenylamino)-9-beta-D-ribofuranosylpurin e, 6-(3-methyl-2-butenylamino)-9-beta-D-ribofuranosylpurine, and their 2-methylthio derivatives. The fifth cytokinin was tentatively identified as 6-(4-hydroxy-3-methyl-trans-2-butenylamino)-9-beta-D-ribofuranosylpur ine. Ribosyl-cis-zeatin was 3-fold higher and N(6)-isopentenyladenosine was correspondingly lower in the plasmid-containing strains than in the plasmidless control. Because the entire syndrome of fasciation caused by infection can be induced with synthetic cytokinins, the disease would appear to be caused by plasmid-induced high rates of cytokinin production by the bacteria.

Journal Article↗

PubMed1972

Induction of the ara operon of Escherichia coli B-r.

The inducer specificity and kinetics of induction of the ara operon were examined in Escherichia coli B/r. A difference in the kinetics of induction was found between our B/r strains and the K-12 strain previously described by Schleif. The roles of active transport and metabolism of inducer, and of cell density, in induction were studied. d-Fucose and beta-methyl-l-arabinoside were competitive inhibitors of induction. No inducer of the wild-type strain other than l-arabinose was found. However, a procedure for selecting mutants with altered inducer affinity or specificity was developed. The properties of one such mutant (inducible by d-fucose) are described.

Arabinose↗

PubMed1968