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Biomedical subjects

D M Evans

Publications and source records attributed to D M Evans.

At least 145 records · Page 8Linked to original sources
PubMed1974

Quality control in cervical cytology.

From surveys conducted by the authors it is concluded that the best and most acceptable quality control methods in cytology are those from within the laboratory. Most of these have results which can be reported centrally. Where the overall control and codes of practice are high, there the results are the most reliable, as sources of error from whatever cause are quickly brought to light. These conclusions are illustrated by data from the five centres and correlated in the tables.

Adult↗
PubMed1974

Observer variation and quality control of cytodiagnosis.

The aim of quality control of a laboratory investigation is to ensure that similar results are obtained on the same material at different centres. To investigate its practicability in cytodiagnosis, the same cytological material was examined independently at six centres. Each centre supplied material from 20 cases, providing a total of 120 cases, ie, 100 cases excluding the donor centre's own material. The degree of agreement between the centres was studied using (a) the standard National Health Service cytology report terminology, (b) the centre's own terminology, and (c) the recommended recall time. The results revealed close agreement between five out of six centres in the reports obtained in relation to dysplasia and malignancy, namely, less than 3% false negative results and not more than 1.7% false positive results. The recommended recall time provided a similar order of agreement after discrepancies due to the management of inflammatory conditions had been eliminated. There was marked disagreement in the diagnosis of both presence and type of infection. The results indicate that improvement in the quality of cytological material would increase the consistency of cytodiagnosis. Cytodiagnosis itself, being an expression of opinion, does not appear to be an appropriate field for quality control.

Candida albicans↗
PubMed1971

Spleen weight in rats during tumour growth and in homograft rejection.

The spleens of rats bearing methylcholanthrene induced sarcomas are enlarged. This applies both to primary and to isotransplanted tumours. The spleen enlarges with increasing tumour size.Splenomegaly is induced by skin homograft rejection, but spleen sizes do not reach those seen during tumour growth, even when the animals are chronically exposed to homologous skin. Sensitization of animals with small tumour homografts gives spleen sizes even greater than those of primary tumour growth.Spleen histology in tumour bearing animals is comparable with that of homograft rejection.The relation of splenomegaly to the presence of tumour specific antigen is discussed. The suggestion is advanced that the spleen size during tumour growth is determined by the product of reaction to foreign antigen, and of reticuloendothelial (phagocytic) activity.

Animals↗
PubMed1971

The primary implantation of human tumours to the hamster cheek pouch.

The hamster cheek pouch is an immunologically privileged site. The present study is of simple implantation of human tumours direct from operative specimen to cheek pouch, in particular to determine whether tumour type influences the rate of successful implant. All implants were studied 10 or 20 days later. The use of cortisone significantly improved the number of implants growing.Carcinomas of the cervix were found to show growth in 55% of implants, in animals conditioned with cortisone. Growth from tumours of the uterine body, or from colorectal carcinomas, occurred in 25-30% of implants. Breast cancer gave poor results.

Animals↗