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Biomedical subjects

M Egan

Publications and source records attributed to M Egan.

85 records · Page 5Linked to original sources
PubMed1979

Comparison of metabolism-mediated binding to DNA of 7-hydroxymethyl-12-methylbenz(a)anthracene and 7, 12-dimethylbenz(a)anthracene.

Comparison of the binding to DNA of 7-hydroxymethyl-12-methylbenza(a)anthracene and 7, 12-dimethylbenz(a)anthracene (DMBA) catalyzed by mouse embryo cells in culture or by rat liver microsomes indicates that the products formed are different for the two hydrocarbons. Thus, the hydroxy compound is not an intermediate in the binding of DMBA to DNA in these systems. Binding of the hydroxy compound to DNA in mouse embryo cells is less efficient than for DMBA and is inhibited by 1,1,1-trichloropropylene 2,3-oxide, an inhibitor of epoxide hydrase. This and the fluorescence spectra of the hydroxy compound-DNA adducts indicate that the hydroxy compound is activated for DNA binding through the formation of a diol-epoxide in the 1,2,3,4-ring. As previously found for DMBA, this is consistent with the activation of this compound through a bay-region diol-epoxide.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1978

Reduction of azo dyes by intestinal anaerobes.

Reduction of seven azo dyes (amaranth, Ponceau SX, Allura Red, Sunset Yellow, tartrazine, Orange II, and methyl orange) was carried out by cell suspensions of predominant intestinal anaerobes. It was optimal at pH 7.4 in 0.4 M phosphate buffer and inhibited by glucose. Flavin mononucleotide caused a marked enhancement of azo reduction by Bacteroides thetaiotaomicron. Other electron carriers, e.g., methyl viologen, benzyl viologen, phenosafranin, neutral red, crystal violet, flavin adenine dinucleotide, menadione, and Janus Green B can replace flavin mononucleotide. These data suggest that an extracellular shuttle is required for azo reduction.

Anaerobiosis↗
PubMedDate not supplied

Pneumoperitoneum following tension pneumothorax. Report of two cases.

Two cases of pneumoperitoneum following tension pneumothorax are described. Lungs in both patients had identifiable pathology and were ventilated with high inflation pressure and moderate positive end-expired pressure (PEEP). Laparotomy was performed in both patients with no evidence of intra-abdominal viscus perforations. A possible mechanism for the production of pneumoperitoneum is discussed.

Adult↗
PubMedDate not supplied

Occupational therapists' perceptions of evidence-based practice.

Occupational therapists are increasingly urged to carry out evidenced-based practice; however, little is known regarding their present practice and perceptions of evidence-based practice. To explore this phenomenon, a qualitative study was completed using a grounded theory approach. Semi-structured interviews were carried out with eight occupational therapists who worked in diverse practice settings. Participants were asked to reflect on their own views of evidence-based practice and their use of evidence in therapy. Data were analyzed inductively using constant comparison analysis. Participants' perceptions of evidence-based practice were described in three broad categories. To these occupational therapists, evidence-based practice is: (a) a process of looking for understanding; (b) associated with research, and; (c) a potential threat to the occupational therapist. These findings produce a basis from which recommendations are made to increase the use of evidence-based practice by occupational therapists.

Adult↗
PubMedDate not supplied

Induction of IL-4 and IL-6 synthesis in vitro: variation in signaling requirements and kinetics are dependent on the anatomic source of the responding mononuclear cells.

We have shown differences in regulation of cytokine mRNA expression in human tonsil, spleen, and peripheral blood. After PHA stimulation of peripheral blood, IL-2, IL-4, and IL-6 mRNA were expressed with similar kinetics: peak expression occurred after four hours and subsequently declined over 48 hr. In PHA-stimulated splenic and tonsillar MNC, IL-2 and IL-6 mRNA were expressed later, with peak expression occurring after eight hours of stimulation and no mRNA detectable after 40 hr of stimulation. The intensity of the IL-6 mRNA signal and the amount of IL-6 secreted was much greater in MNC from peripheral blood than in spleen and tonsil and correlated with the percentage of monocytes in MNC from each tissue. IL-4 mRNA expression differed in all three tissues: PHA-stimulated tonsillar MNC expressed IL-4 mRNA with a major peak at eight hours and a minor peak at 24 hr after stimulation. The kinetics of mRNA were not due to effects of mixed cell populations. The same bimodal peak was observed in purified tonsillar T lymphocytes, and the minor 24-hr peak was dependent on IL-4 mRNA synthesis by cells expressing high amounts of VLA-beta 1 antigen (CDw29) on their surface and which lacked the CD45 epitope recognized by the mAb 2H4. Splenic MNC did not express IL-4 mRNA when stimulated with a number of mitogens and only exhibited IL-4 mRNA expression when stimulated with the combination of PHA and PMA or anti-CD3. Thus, IL-4 mRNA has markedly different kinetics and intensity of expression in spleen, peripheral blood, and tonsil.(ABSTRACT TRUNCATED AT 250 WORDS)

Humans↗