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Biomedical subjects

T M Callaghan

Publications and source records attributed to T M Callaghan.

4 recordsLinked to original sources
PubMed1995

The effect of an educational brochure on knowledge and early detection of melanoma.

Men over the age of 45 present with thicker, more advanced melanomas than younger people. A randomised trial was conducted in this group to evaluate whether an educational brochure would increase knowledge about melanoma and the ability to recognise and discriminate between pigmented skin lesions. Men in an industrial complex were allocated to an intervention group (n = 110) and two control groups (n = 96 and n = 108). The intervention group was given two educational brochures about melanoma. Their effect on knowledge and ability to detect pigmented lesions was assessed by a questionnaire and a self-examination body chart given before the brochure, and at four weeks and three months after return of the brochure. The control groups did not receive any educational material, but control group 2 received the questionnaire and chart. At the end of the study all participants were examined for pigmented lesions by doctors, whose counts were compared with those of the participants. There was a significant (19.8 per cent) increase in knowledge about melanoma in the intervention group (but not in the control groups), except for discrimination of photos of benign and malignant lesions. The educational material did not improve the ability of those in the intervention group to recognise and count their pigmented lesions nor to discriminate between benign and malignant pigmented lesions. The increased knowledge about melanoma was retained for at least three months.

Aged↗
PubMed1991

Clinical utility of high-resolution portal films.

We have evaluated the film quality and overall clinical utility of a unique high-resolution portal film system which utilizes high contrast graphics art film. A total of 127 unselected patients had their conventional portal films and high-resolution films of the same site, compared and graded subjectively for a variety of parameters by an independent panel of radiotherapists and radiographers. Although consistent improvements in most aspects of image quality were noted, improved overall clinical usefulness of the high-resolution portal film system in comparison to the conventional films, when subjected to multiple regression analysis, was confined to lateral neck views only. High-resolution portal film utility was also found to depend significantly on field size with areas less than 110 cm2 having a markedly worse clinical utility score.

Humans↗
PubMed1990

Modulation of the binding and endocytosis of concanavalin A by guinea pig keratinocytes: reversible antagonistic effects of cholesterol and phospholipid-liposomes.

Alteration of guinea pig keratinocyte membrane microviscosities (eta) by liposomes of varying composition was determined by fluorescence polarization of 1,6-diphenyl-1,3,5-hexatriene. Measurements performed either with whole cell suspensions or Percoll-separated cell subpopulations, indicate a similar membrane microviscosity (eta = 3.37 poise +/- 10%) compared to those microviscosities reported for other cell types. Our findings show that treatment of guinea pig keratinocytes with liposomes composed of phospholipids results in a decreased membrane microviscosity (1.95 poise), whereas treatment of the cells with an emulsion of cholesterol hemisuccinate, or liposomes composed of cerebrosides, causes an increase in membrane microviscosity (3.85 poise and 5.55 poise +/- 10%, respectively). Changes in membrane fluidity had no significant effect on cell viability. A reduced membrane microviscosity resulted in a decrease in the binding of Concanavalin A to keratinocytes, whereas an increased microviscosity resulted in an increased binding of Concanavalin A. Furthermore, endocytosis of Concanavalin A bound to keratinocytes plasma membranes was not significantly affected by a reduced membrane microviscosity, whereas an increased membrane microviscosity completely blocked the endocytosis of Concanavalin A. Another novel observation was that membranes "fluidified" by phospholipid liposomes could be "rigidified" by treatment with cholesterol hemisuccinate and vice versa. Moreover, these alternate changes in membrane microviscosity resulted in simultaneous alternate changes in the binding of Concanavalin A to the keratinocyte surface.

Animals↗