Preparation of membrane pellet Tumour specimens removed from -70'C were allowed to thaw on ice, while those from sucrose/glycerol were re-hydrated in homogenising buffer (see below). The tumour specimen was dried with tissue paper to remove any excess water or buffer. Specimens were washed in ice cold saline. The tumour was bisected and two separate samples of tumour were cut (2-3 mm minimum) from either half, one piece placed in formal saline for pathological analysis and the other in sucrose/glycerol buffer for later immunohistochemical analysis (to be reported later). The remainder of the tumour was used for the biochemical assay. Fresh homogenising buffer was prepared (20 mM Hepes, 2 mM EDTA, 0.5 mM PMSF to pH 7.4). Tumour sections were then cut into small 1 mm blocks and weighed (usually 1 gram), then placed in a centrifuge tube to which was added 5 ml g-' (wet weight) of ice cold homogenising buffer. Tumour was homogenised on ice with an ultra turrax (Janke and Kunkel) with 2 x 15 s bursts at maximum speed but allowing the homogenate to cool between bursts. The homogenate was centrifuged at 1,000 g for 10 min. The resulting supernatant was centrifuged at 12,000 g for 1 h. The nuclear pellet was resuspended in homogenising buffer and stored at -20C until required for DNA analysis (Modified Burton). The pellet from the high speed spin was resuspended in 1-2 ml of radioimmunoassay buffer (RIA buffer: 0.2 M Na2HPO4, 0.2 M NaH2PO4, 0.1% sodium azide, 0.15 M sodium chloride, 0.1 M EDTA and 0.5% bovine serum albumin to pH 7.4) depending on the initial wet weight (1 ml 500 mg-') and stored at -20C in 1.5 ml polystyrene tubes (Eppendorfs). Prior to storage each suspension was submitted to glass teflon homogenisation to ensure an even suspension.

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Summary Epidermal growth factor and transforming growth factor alpha are two peptides which bind to the epidermal growth factor receptor. One hundred and seventy-four samples from 133 patients with ovarian cancer were examined for EGF and TGFa. EGF was detected in only 27.6% of samples while TGFa was present in 88.5%. The median values for TGFa presence were at least 10-fold greater than those of EGF. There was no statistical difference between either TGFa or EGF levels and degree of differentiation of the tumours. There was no statistical difference between stage three and four in relation to concentration of either peptide. Median concentration did not differ significantly among the histological sub-groups.Epidermal growth factor (EGF) interacts with its receptor, epidermal growth factor receptor (EGFR), initiating the responses which can lead to growth modulation. Additionally such ligand-receptor interaction induces pleiotropic effects in the cell including enhanced glycolysis, increased amino acid transport, calcium, sodium and hydrogen ion exchange and protein synthesis (Owen et al., 1982). Another growth factor, transforming growth factor alpha (TGFa) binds to the EGFR. Sporn and Roberts (1985) for pathological analysis and the other stored in sucrose/ glycerol buffer for later immunohistochemical analysis. Fresh homogenising buffer was prepared (20 mM HEPES, 2 mM EDTA and 0.5 mM PMSF adjusted to pH 7.4 with sodium hydroxide) and stored on ice. The two tumour sections, from which the samples for pathology had been removed (usually 1 g) were then cut into small 1 mm blocks, weighed and placed in a centrifuge tube on ice. Homogenising buffer (5 ml g-'wet weight) was added.The tumour was homogenised on ice with an ultra turrax (Janke & Kunkel) with 2 x 15 s bursts at maximum speed but allowing the homogenate to cool between bursts. The resulting homogenate was an even suspension devoid of clumps of tumour tissue. The homogenate was centrifuged at 1,000 g for 10 min. The resulting supematant was subjected to a higher speed spin (12,000 g for 1 h). The nuclear pellet from the first spin was resuspended in 3 ml of homogenising buffer and stored at -20°C until required for DNA analysis (Modified Burton). The supernatant from the high speed spin was added to two volumes of ice cold alcohol and this was centrifuged at 1,000 g for 30 min. The supernatant from the alcohol extraction was added to four volumes of ice cold ethyl acetate and placed in a fridge overnight (4°C). After 16 h a crude extract precipitated to the bottom of the vessel. The supernatant was discarded and the crude extract was suspended in 2 ml of 1 N acetic acid.

Summary Interleukin-2 receptor (IL-2R) can be detected in serum. We estimated the IL-2R in the serum of 78 women, of whom 30 were diagnosed as having malignant ovarian tumours, five had non ovarian tumours, one had a negative second look laparotomy, 11 had benign ovarian tumours, three had uterine fibroids and 28 were age-matched controls. The results indicated that the serum IL-2R of these patients was significantly elevated in ovarian cancer patients compared to both controls (P<0.0001) and benign ovarian tumours (P< 0.0002). There were no significant differences in IL-2R levels between stage of disease and degree of differentiation within the ovarian tumour group.

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