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Biomedical subjects

J Law

Publications and source records attributed to J Law.

At least 109 records · Page 6Linked to original sources
PubMed1989

Films, screens and cassettes for mammography.

Various film-screen combinations intended for mammography have been compared for image quality and for dose. Image quality was assessed as in an earlier paper, using a test object having details which are both realistic and quantitative. Relative doses required to give film densities of 1.0 were measured. The Kodak MinR-MinR combination was taken as a standard against which others were compared, and in general a lower dose was accompanied by poorer image quality. The Fuji NH film with Fuji Hi-Mammo screen was the sole exception, giving slightly better image quality at about half the dose required by the MinR combination. A number of cassettes were also compared with each other and with evacuated envelopes. The Dupont Cronex cassette and three carbon-fibre fronted cassettes all performed well in image quality.

Equipment Design↗
PubMed1989

Surveillance--shifting priorities.

Development surveillance and particularly the identification of children with impaired speech and language development is an area which has recently attracted considerable attention. Given that language delay is the single most common pre-school problem this is not surprising. This short paper looks at two offerings on the subject and asks whose interest the proposed changes serve. The first of these is Walter Barker's paper 'The value of developments tests' and the second is the findings of the national working party on child health surveillance.

Community Health Nursing↗
PubMed1988

The cloning of the rorB gene of Escherichia coli.

A segment of the Escherichia coli genome which complements the ionising radiation sensitivity of the rorB mutation was cloned into pBR322. This DNA segment also complements the mitomycin C sensitivity of the rorB mutation. The gene was subcloned until defined in a fragment of 1.05 kb. Only one gene product, a protein of approximately 16.5 kDa, was found on maxicell analysis of the various subclones. Iso-electric focusing of this gene product suggests it may function in a complex.

Cloning, Molecular↗
PubMed1988

Reactivity of tumor cells in malignant effusions with a panel of monoclonal and polyclonal antibodies.

A panel of 13 mouse monoclonal antibodies (mAb) and 1 rabbit polyclonal antibody was tested for reactivity with tumor cells in 26 effusions obtained from patients with carcinoma of ovary, breast, or mesothelioma, using an immunoperoxidase staining reaction. Specific staining of tumor cells but not reactive mesothelial cells was demonstrated with some of the mAb in the panel. In 4 of 26 effusions no evidence of malignancy was obtained after routine cytological staining, but this was reversed on the basis of immunoperoxidase staining of tumor cells with the mAb in the panel. Serial effusions were evaluated in 4 patients during the course of chemotherapy, allowing an assessment of effect of therapy on the antigenic characteristics of the tumor cells. In another 4 patients, the results of immunoperoxidase staining of effusions were compared with those obtained by applying the same antibody panel to solid tumor nodules. There was a tendency to develop changes in the pattern of reactivity during therapy, and the pattern of reactivity was more restricted in tumor nodules than in effusions. One of the mAb in our panel (2G3) was consistently shown to produce strong staining of a high proportion of tumor cells in effusions and tumor nodules from patients with ovarian or breast cancer and may be of value in immunocytochemical diagnosis and therapy of epithelial malignancies.

Animals↗
PubMed1988

Film processing for mammography.

The effect of processing time and temperature on image quality in mammograms was investigated over the ranges 2.5-4 min and 30-36 degrees C. Image quality results from seven processors of different manufacture and different processing methods, operated at a range of times and temperatures, showed the same image quality except for one which received little use. Effects of these parameters on the patient dose required were also considered, longer times up to 4 min and higher temperatures up to 36 degrees C being advantageous. No variation was found with processor design or mechanism of action. Implications for screening programmes are briefly discussed and an optimum regime of 3.5 min and 36 degrees C is suggested.

Mammography↗
PubMed1987

A comparative study of films and screens for mammography.

Ten films and six screens suitable for mammography have been compared for image quality using a realistic quantitative phantom under controlled conditions. The best screen was Min R (Kodak), but three black and white films, Min R (Kodak), Fuji II NC (Fuji) and MR3 (Agfa-Gevaert), scored highly. Patient dose was also considered and, with these three films, small gains in image quality were balanced by small increases in dose. Medichrome Blue film, however, gave the highest score of all, and did so for a dose that was less than the highest. These results were confirmed on a second phantom of entirely different design.

Female↗
PubMed1987

Cancers induced and cancers detected in a mammography screening programme.

The numbers of cancers which might be induced in a breast screening programme are compared with the numbers detected. The induction rate is estimated from reports of breast cancer in various groups exposed to high radiation doses, and also from International Commission on Radiological Protection risk estimates. An apparent discrepancy between these two approaches is discussed and removed. Detection rates are based on preliminary results in Edinburgh, and greatly exceed the induction rate. Whether such an excess is maintained if an X-ray grid requiring a higher dose is used on younger age groups is discussed.

Adolescent↗