Summary A murine monoclonal antibody PASE/4LJ to prostatic acid phosphatase (PAP) was used to immunostain a wide variety of sections of benign and malignant tissues (654 blocks). Non-neoplastic adult and fetal prostatic glands, primary and metastatic prostatic carcinomas, and scattered cells in prostatic and penile urethra were positive. Rat, dog and rabbit prostates were negative. Nine of 400 tumours of non-prostatic origin showed some positivity: 6/36 carcinoids, 1/9 islet cell tumours, 1/55 ovarian adenocarcinomas (serous) and one carcinosarcoma of the lung (epithelial portion). Positive staining was seen in islet cells in 4/5 specimens of normal pancreas, and in 4/9 blocks of normal pancreas surrounding a pancreatic tumour. Loops of Henle, maculae densae, and distal tubules in 10/10 fetal and 2/9 adult kidneys were also positive, with proximal tubules and collecting ducts negative. All other 159 blocks of non-neoplastic adult and fetal tissues were negative. The antibody was also affinity purified from ascitic fluid, and shown not to inhibit the enzyme activity of prostatic acid phosphatase.

Six different immunisation regimes have been used to generate spleen cells with reactivity against human pancreatic exocrine cancer. Immunised spleen cells were fused with an NSO/1 myeloma line and supernatants from these hybridomas selectively screened for monoclonal antibodies which bound predominantly to a pancreatic cancer cell line (GER). The spleen cells from hairy litter mates immunised with pancreatic cancer xenograft homogenates and viable GER cells generated 13% of hybridoma supernatants which showed some selectivity for GER pancreatic cancer cells in a fixed cell ELISA assay. The other methods produced only 4% of hybrids with selectivity for GER cells. The antigen distribution on gluteraldehyde fixed cells was similar to that found for viable cell monolayers but many antigens were unstable on formalin fixation. Immunohistochemical staining of GER cells grown on glass slides showed a heterogeneity of antigen distribution with up to 70% of the cells exhibiting a vesicular pattern of staining. Fifty percent of the antibodies which bound to GER cells were also reactive against antigens in formalin-fixed paraffin-embedded tissue sections of the original GER tumour. Monoclonal antibody DD9E7 identified an antigen expressed on 12/14 pancreatic adenocarcinomas. The antibody showed strong staining of malignant luminal membranes and cytoplasm. The antigen was also present in normal salivary and sweat glands, and colon and breast carcinomas, but its tissue distribution was unlike that of CEA or EMA. The expression of this antigen in 12/14 of pancreatic carcinomas suggests that DD9E7 may be a useful reagent for pancreatic tumour detection. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6

In England and Wales there has been a substantial increase in adenocarcinomas of the exocrine pancreas over the past 75 years. The mortality trebled from an age standardised rate for both sexes of 2-9 per 100 000 in the quinquennium [1911][1912][1913][1914][1915]

Summary Fine needle aspirates from 82 patients with breast carcinoma were fixed in methacarn, double embedded in agar or gelatin, and then in paraffin wax. Sequential sections were stained with monoclonal antibodies to the oestrogen receptor-related protein P29 (antibody D5), carcinoembryonic antigen (CEA), epithelial membrane antigen (EMA) and cytokeratin (CAM 5.2). Sixty-one of 82 (74%) aspirates provided sections suitable for immunostaining. Twenty-six (43%) were D5 positive, 23 (38%) CEA positive, 59 (97%) EMA positive, and 54 (89%) CAM 5.2 positive. Twenty-six of these patients were treated with some form of endocrine therapy. Twelve (46%) showed positive staining for D5. Eleven (92%) of the 12 D5-positive patients responded or had static disease, and 8% progressed. Of the 14 D5-negative tumours 43% responded or remained static, and 57% progressed. The difference in response between the D5-positive and the D5-negative tumours was significant (P<0.05, Fisher's exact test). There was no correlation between staining for CEA, EMA or cytokeratin and response to endocrine therapy.Biochemical estimation of the oestrogen receptor (ER) content of breast tumours is a well established predictor both of response to endocrine therapy and of survival (Seibert & Lippman, 1982;Witliff, 1984 Greene, 1984) and related proteins (King et al., 1985) are now available. The mouse monoclonal antibody D5 directed against the oestrogen receptor-related protein, P29, can be used to immunostain paraffin embedded material fixed in alcohol or in methacarn, without enzyme predigestion (King et al., 1985;Cano et al., 1986). The rat monoclonal antibody directed against the nuclear oestrogen receptor protein (ERICA antibody, Abbott Laboratories, Chicago, USA) requires either fresh unfixed tissue or DNAse pretreatment of paraffin embedded sections (Shintaku & Said, 1987).There have been reports of the predictive value of staining with other antibodies. It has been stated that the presence of carcinoembryonic antigen (CEA) (Shousha et al., 1979;Walker, 1980), and the intensity of staining for a material similar to the large glycoprotein, termed epithelial membrane antigen (EMA) (Heyderman et al., 1985), using monoclonal antibodies HMFG1 (Wilkinson et al., 1984) Although smears prepared from fine needle aspirates have been used for the immunocytochemical localisation of oestrogen receptor and related proteins (Flowers et al., 1986;Cavailles et al., 1987;Coombes et al., 1987), these preparations are unsuitable for the comparative demonstration of multiple markers due to the variation in number of cells per slide, and limitations in the number of slides that can be prepared from a single aspirate. An alternative approach has been to expel the aspirates into tissue culture medium, and make cytospin preparations on polylysine coated slides (Hawkins et al., 1988 The aim of this study was to evaluate a quick and easy method suitable for a busy outpatient clinic, which would allow samples to be sent through the post for further processing, with no ...

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