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J W Meakin

Publications and source records attributed to J W Meakin.

30 records · Page 2Linked to original sources

Androgen receptors: relationship to growth response and to intracellular androgen transport in nine variant lines of the Shionogi mouse mammary carcinoma.

Aspects of the biological significance of androgen receptors have been studied in nine variant lines of the Shionogi carcinoma, two of which are androgen dependent and seven of which are autonomous. The dependent lines, and two of the seven autonomous lines, contain androgen receptors; this finding demonstrates that the presence of receptors is not an accurate marker of hormonal dependence in vivo. Since the ability to transport androgens into the nucleus, as judged from the relative maximal rates of transport, is virtually restricted to dependent and autonomous lines which possess cytoplasmic receptors, it is clear that such receptors may play a role in regulating the intranuclear concentration of androgens. The absence of cytoplasmic receptors and the comparative lack of perceptible transfer of androgens across the nuclear membrane are features peculiar to the autonomous condition.

Animals↗

External irradiation of the hypophysis for Cushing's disease.

During the past 12 years 17 patients with Cushing's disease (bilateral adrenal hyperplasia secondary to excessive pituitary adrenocorticotrophic hormone) have been treated initially with external pituitary irradiation. Of the 15 patients who have had adequate follow-up, nine showed complete biochemical remission, and one showed biochemical improvement. There were no complications. It is therefore recommended that the first mode of therapy for all patients with Cushing's disease should be pituitary irradiation if the patient's clinical condition permits.

17-Hydroxycorticosteroids↗

Tamoxifen therapy in premenopausal patients with metastatic breast cancer.

Tamoxifen was evaluated in a phase II trial as initial hormonal therapy in premenopausal patients with metastatic breast cancer. The study design was such that responders remained on tamoxifen therapy; those who initially or subsequently progressed went on to ovarian ablation either by surgery or irradiation. Of 42 evaluable patients treated with tamoxifen, three had complete responses (CR), ten had partial responses (PR), and four remained stable (ST), giving total response rates of 32% (CR + PR) or 41% (CR + PR + ST). Among the 18 patients with positive estrogen (ER) or progesterone (PgR) receptors, there were eight responders, but only one responder (ST) in the nine patients with negative ER or PgR. Of the 25 patients who failed to respond to tamoxifen, 13 underwent ovarian ablation; all failed to respond. These 13 included four patients who were ER positive or equivocal and PgR positive or unknown. Nine tamoxifen responders (CR + PR + ST) have subsequently progressed; of these, eight have gone on to ovarian ablation. Six of these eight have responded (five PR and one ST) to ovarian ablation, and one has failed to respond. Thus, steroid receptors generally predicted a patient's response to tamoxifen therapy, but response to tamoxifen also strongly predicted a patient's subsequent response to ovarian ablation.

Adult↗