Biomedical subjects

L G Poels

Publications and source records attributed to L G Poels.

58 records · Page 4Linked to original sources

PubMedDate not supplied

Biodistribution of iodine-125 and indium-111 labeled OV-TL 3 intact antibodies and F(ab')2 fragments in tumor-bearing athymic mice.

The monoclonal antibody OV-TL 3, directed against an ovarian carcinoma-associated antigenic determinant, was tested as a vehicle for radioimmunolocalization of ovarian carcinomas in athymic mice bearing NIH:OVCAR-3 xenografts. The biodistribution of intact. OV-TL 3 was compared with the distribution of OC 125. Tumor uptake with OV-TL 3 was significantly higher than with OC 125, and almost 7 times higher than with a non-specific control antibody (OV-TL 19). Administration of a mixture of intact OV-TL 3 and OC 125 did not improve tumor uptake in comparison with OV-TL 3 alone. Subsequently, intact OV-TL 3 and its F(ab')2 fragments were labeled with either 111In or 125I. The highest tumor uptake was obtained with 111In-labeled intact OV-TL 3 (14.7% ID/g, 48 hr p.i.). For both antibody forms uptake of 111In in liver, spleen and kidneys was very high. Furthermore, 111In cleared more slowly from most tissues than 125I. As a result, tumor/tissue ratios with 111In-labeled OV-TL 3 were lower than with 125I-labeled OV-TL 3. The highest tumor/tissue ratios (6.9 to 53) were obtained with 125I-labeled OV-TL 3 F(ab')2 fragments, 48 hr post injection. 111In-labeled OV-TL 3 F(ab')2 has already been shown to be a clinically useful label for the detection of ovarian cancer. The results of our comparative animal study suggest that these clinical results may even be improved by using 123I-labeled OV-TL 3 F(ab')2.

Animals↗

PubMedDate not supplied

A direct LHRH-agonist action on cancer cells is unlikely to be the cause of response to LHRH-agonist treatment.

LHRH-Agonist therapy has been shown to have some effect in cancer treatment. Chronic administration of LHRH-agonists may lead to a decreased gonadal steroidogenesis. A direct anti-tumor action of LHRH-agonists has also been reported. We observed only a small direct inhibitory effect of the LHRH-agonist Buserelin at high concentrations on the proliferation of three human ovarian cancer cell lines, and on estrogen-stimulated proliferation of human breast cancer cells in vitro. Proliferation of rat prostate cancer cells was not inhibited by Buserelin. It is unlikely that a direct anti-tumor effect is the major mechanism of action of LHRH-agonists in cancer treatment.

Animals↗

PubMedDate not supplied

Multiple parameter analyses of human ovarian cancer: morphology, immunohistochemistry, steroid hormone receptors and aromatase.

All human ovarian tumors (n = 32) analysed were positive for cytokeratin except for a single case. OV-TL 3 stained 96% (26/27) and 1 out of 4 controls, while OC-125 stained 86% (24/27) and 3 out of 4 non-ovarian carcinomas. Androgen receptors predominated (AR-96%) compared to estrogen (ER-32%) or progestin (PgR-50%) receptors in the ovarian carcinomas. Aromatase activity was detected in 6 ovarian carcinomas and in 3 non-ovarian carcinomas. No definite relationship was observed between the parameters measured. Ovarian carcinomas stained brightly with OV-TL 3 and OC-125 had high AR levels, while focal or absent reaction was related to low AR levels. A role for androgens in ovarian cancer is suggested.

Adult↗

PubMedDate not supplied

Immunocytochemical detection of ovarian carcinoma cells in serous effusions.

Monoclonal antibodies OC 125, OV632, OV-TL 3, MOv18 and OV-TL 23, directed against distinct ovarian carcinoma-associated antigens, were examined for their value in cytopathologic diagnosis. Their sensitivity and specificity in staining ovarian carcinoma cells in serous effusions we determined using the indirect immunoperoxidase technique. Smears prepared from 140 serous effusions (73 benign, 67 malignant) were immunostained with the five antibodies. OC 125 and MOv18 reacted positively with 96% and 81% of the smears of effusions from ovarian carcinoma patients, respectively, while OV-TL 3, OV632 and OV-TL 23 stained a lower percentage of the samples (73%, 65% and 62%, respectively). In discriminating ovarian carcinoma cells from benign (mesothelial or inflammatory) cells in serous effusions, MOv18 demonstrated the highest specificity (100%) since none of the 73 samples from benign effusions were stained upon incubation with this antibody. OC 125 cannot be used for this purpose due to its reactivity with mesothelial cells in benign samples. Staining cytologic preparations of malignant effusions from cancer patients with carcinomas not originating in the ovary revealed that OV632 and OV-TL 23 may be useful adjuncts to determine the origin of the carcinoma cells found in serous effusions. The reactivity of these antibodies was highly selective for ovarian carcinoma cells, staining only 6% and 0% of the samples from the non-ovarian carcinoma samples, respectively. It is concluded that MOv18 is the most suitable antibody for distinguishing ovarian carcinoma cells from mesothelial cells in serous effusions, while OV632 and OV-TL 23 especially may help to assess whether carcinoma cells found in effusions originate in the ovary.

Antibodies, Monoclonal↗