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Biomedical subjects

S Cowan

Publications and source records attributed to S Cowan.

48 records · Page 3Linked to original sources

Oestrogen receptor status of breast cancers from related patients.

Breast tumours from nine pairs of related women have been studied with respect to their oestrogen receptor (ER) concentrations and histological appearance and grade. 72% of these tumours were oestrogen receptor positive in both soluble and nuclear fractions. in eight of the nine pairs, the tumours were of the same ER status. Apart from a suggestion of a similar host response to the tumours in two related pairs, the histological appearance of the tumours showed no striking similarities. This small study suggests that familial breast cancers are more likely to be hormone dependent.

Breast Neoplasms↗

Pre-operative determination of oestrogen receptor status in breast cancer by immunocytochemical staining of fine needle aspirates.

The results of pre-operative staining of fine needle aspirate (FNA) samples from 48 breast cancers, with a polyclonal antibody raised against highly purified oestrogen receptor (ER) protein, have been compared with our standard biochemical method for measurement of cytosol and nuclear ER. FNA antibody staining correctly predicted the presence of ER in 20 of 21 ERC +/N+ tumours. There were 2 false positive results in 24 ER C-/N-tumours though both these tumours showed marked heterogeneity of staining. Three ER C+/N- tumours were negative by antibody staining, in keeping with the tendency for such tumours to be hormone independent in behaviour. This pre-operative method for ER determination appears to be a reliable alternative to other micro-assays for oestrogen receptors.

Biopsy, Needle↗

New storage procedure for human tumor biopsies prior to estrogen receptor measurement.

Breast tumor biopsies required for steroid receptor determination are normally frozen in liquid nitrogen and stored until assay. However, some limitations of this type of storage exist. To try to both eliminate the need for liquid nitrogen and as part of a study of serial assays on a single tumor biopsy, alternative storage media were investigated. This study shows that storage of breast tumor biopsies at -20 degrees in sucrose buffer made 50% in glycerol prevented the tissues from freezing, yet retained the specific estrogen receptor content both quantitatively and in terms of molecular form (8S:4S ratio). Receptor was stable for up to 100 days, and individual samples could be successfully reassayed throughout this period. Forty-four biopsies from 40 patients were halved, and one section from each was stored in liquid nitrogen, while the other was stored in sucrose:glycerol. Overall, the correlation of receptor content between the two storage methods was good. Using a clinical cutoff value of 20 fmol/mg cytosol protein, only one sample of the 44 would have been classified differently after storage in the two media. Progesterone receptor in biopsies stored in sucrose:glycerol also appears to be stable for at least a limited period.

Biopsy↗

Intra-tumoural variation of oestrogen receptor status in endometrial cancer.

Soluble and nuclear oestrogen receptor status was determined in both the central and peripheral portions of tumour for 37 cases of adenocarcinoma of the endometrium. Of these, 29 had functional receptor in the peripheral biopsy, but only 19 retained functional receptor in the centre. Six of the 10 patients whose tumours showed this difference came from the group of 12 patients who were immediately post-menopausal (4.50 +/- 1.45 y post-menopausal age). Receptor status was not related to tumour classification into histological grades I and II. However, receptor-negative central biopsies were significantly more likely (P less than 0.05) to be Grade III. Early relapse was also related to a receptor-negative central biopsy.

Adenocarcinoma↗

A study of endometrial RNA polymerase activity in infertile women.

Endometrial RNA polymerase activity, which is sensitive to oestrogens and progesterone, has been measured in normal and infertile patients. One-third of the infertile patients studied had abnormal values. An analysis of the relationship of abnormal RNA polymerase activity to clinical abnormalities and to pregnancies occurring without treatment suggests that this assay may detect a biochemical fault in the endometrium which is related to the failure to conceive.

DNA-Directed RNA Polymerases↗