Involvement of translation and transcription in insect steroidogenesis.

The involvement of protein and RNA synthesis in insect steroidogenesis was investigated using the prothoracic glands of the tobacco hornworm Manduca sexta. Ecdysone secretion stimulated by prothoracicotropic hormone (PTTH) and by cAMP analogs such as dibutyryl cAMP (dbcAMP), was suppressed by the translation inhibitors cycloheximide and puromycin, and by the transcription inhibitor actinomycin D. Inhibition of protein synthesis did not prevent the activation of glandular kinases, as indicated by continued protein phosphorylation in the presence of cycloheximide.

Relationship between flow cytometric parameters, steroid receptors, and menopausal status in breast cancers.

Of 163 human breast cancers examined, 68% contained detectable aneuploid populations, whilst 32% had apparently normal DNA distributions. A slightly higher incidence of aneuploidy was observed in pre-menopausal patients (83%) than in post-menopausal patients (66%). Also, pre-menopausal patients had slightly higher proportions of S-phase or cycling (S + G2 + M) cells.

Value of hormone receptors in the management of breast cancer--I. Advanced breast cancer.

A review of 152 women with locally advanced or metastatic breast cancer is presented. Only 32% of unselected women responded to appropriate endocrine therapy; 64% responded if ER was present and 71% if both ER and PR were present. Survival for the endocrine responders was prolonged and of good quality.

The effect of tamoxifen on the growth of human malignant melanoma in vitro.

The effect of tamoxifen on the growth of malignant melanoma was investigated using human cell lines and single-cell suspensions prepared from patients' tumours cultured in soft agar. Tamoxifen stimulated both [3H]-thymidine incorporation and cell numbers in all of the cell lines tested. Cytoplasmic oestrogen receptor (ER) was detected in one of the responding lines and progesterone receptor (PR) in another.

Properties and interpretation of the Woolf and Scatchard plots in analysing data from steroid receptor assays.

The Woolf plot has been shown to have superior statistical properties compared with the Scatchard plot in analysing data from steroid receptor assays. This paper examines the properties of the Woolf plot, with a view to aiding its interpretation and improving familiarity with it so that its use may become more widespread. The Woolf plot contains the same information as the Scatchard plot, and deviations from linearity of the plot due to positive cooperativity, second binding sites, or non-specific binding are readily identifiable, and are described.