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Biomedical subjects

D C Mason

Publications and source records attributed to D C Mason.

6 recordsLinked to original sources
PubMed1978

Automated measurements on human C-bands in family studies.

An automated system providing quantitative measurements of C-band size has been used, in conjunction with statistical methodology developed for the purpose, in a family study to demonstrate its potential in determining the mode of transmission of C-bands from parent to offspring, and to test the assumption of Mendelian inheritance. The most serious obstacle encountered was the high within-person variance of the normalized band sizes, the large within-slide variance being increased by technical variation between different preparations. Attempts to reduce variance by developing more effective normalization techniques did not prove fruitful. Nevertheless, the ability of the present system to perform a trace using a reasonable number of cells has been demonstrated in an example. In the two families studied we saw no evidence that band size was not transmitted and changes in band size, if any, were less than about 5 micrometer2 X 10(-2) (compared to a typical medium-category band size of about 65 mcirometer2 X 10(-2)).

Automation↗
PubMed1977

The vectorcardiogram in subjects with sex chromosome aneuploidy.

Vectorcardiographic variables have been studied in patients with sex chromosome abnormalities and compared with normal controls. Several of these variables were found to be correlated with the number of sex chromosomes in the karyotype, some being related to the number of X chromosomes, some to the number of Y chromosomes, and others to both. The variables concerned included time intervals and vector magnitudes in both the QRS and ST-T wave complexes. The heart rate itself proved dependent on both the X and the Y chromosome complements. The correlations could not be explained by age, height, or weight differences between the seven different karyotype groups studied. The dependences of variables other than the heart rate remained after correction for between-group heart rate differences. The findings are discussed.

Adult↗
PubMed1976

A computerised microscope focusing technique.

An automatic focusing technique for a computer-controlled optical microscope is described, which is based on an algorithm originally proposed by Mendelsohn and Mayall. The procedure is capable of attaining a focusing accuracy of less than 1/20 micron in the slide-objective distance. The dependence of focusing accuracy and time to focus on the scanner signal-to-noise ratio, and the change in the focus position with time, are discussed.

Chromosomes↗