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Biomedical subjects

J O Davies

Publications and source records attributed to J O Davies.

8 recordsLinked to original sources

Medical dilatation of the non-pregnant cervix: the effect of ethinyl oestradiol on the visibility of the transformation zone.

The cervical transformation zone (TZ) was not fully visible in 25 women referred to the colposcopy clinic with cytological suspicion of cervical intraepithelial neoplasia (CIN). Each was given a 5-day course of oral ethinyl oestradiol during the follicular phase of the menstrual cycle, and colposcopy was then repeated. The transformation zone was visible at this second examination in 16 of the 25 patients. Of these patients, 11 were treated with a local destructive technique, nine by laser, two by cryocautery; one patient had a cone biopsy, and four patients did not require treatment. Although cone biopsy was necessary in 8 of the remaining 9 patients it is encouraging that the use of a simple medical regimen allowed us to avoid conisation and its morbidity in almost two thirds of these patients.

Adult↗

Radionuclide imaging of ovarian tumours with a radiolabelled (123I) monoclonal antibody (NDOG2).

The biodistribution of a radiolabelled monoclonal antibody (123I-NDOG2) was studied in patients with ovarian tumour. It was found that the uptake patterns in known tumour sites was variable and that the clearance of the agent from the vascular pool was due to renal excretion of the radionuclide and the redistribution of the radioactively labelled compound into other compartments. The mean (+/- SD) plasma clearance time was 20.8 (+/- 2.3) h and the ratios of target (tumour) to background (thigh) ranged between 1.4 and 4.8. The ratio between the plasma radioactivity at either 3.5 or 20 h after administration was calculated relative to the initial plasma radioactivity. These values (0.79 and 0.48, respectively) were incorporated into an image-subtraction technique that allowed for redistribution outside the vascular pool. A whole-body dose equivalent to 16.3 mu Sv MBq-1 (60.4 mrem.mCi-1) was calculated.

Antibodies, Monoclonal↗

Placental alkaline phosphatase in benign and malignant endometrium.

The presence of placental alkaline phosphatase has been demonstrated immunohistochemically using a monoclonal antibody, in frozen sections of human endometrium. The enzyme is present in glandular epithelium, but is found most commonly in the surface epithelial layer throughout the menstrual cycle. It has also been demonstrated in malignant endometrial epithelium in eight out of twelve patients.

Alkaline Phosphatase↗

Radionuclide imaging of ovarian tumours with 123I-labelled monoclonal antibody (NDOG2) directed against placental alkaline phosphatase.

A radiolabelled monoclonal antibody (NDOG2) directed against placental alkaline phosphatase (PLAP) was used in the radio-immunodetection of ovarian carcinoma. Tumour deposits were successfully visualized in 11 of 15 patients and the abnormalities demonstrated were classified as focal or diffuse. Of the 11 patients, eight showed focal abnormalities alone and three had a diffuse abnormality, of which two also showed a focal abnormality. False-positive results may occur not only due to uptake of 123I by gut mucosa and an inadequately blocked thyroid gland but also from activity in an incompletely emptied bladder. A false-negative result occurred due to high background activity in the liver masking a known, discrete tumour deposit.

Alkaline Phosphatase↗

Practical applications of a monoclonal antibody (NDOG2) against placental alkaline phosphatase in ovarian cancer.

A monoclonal antibody (NDOG2) against placental alkaline phosphatase (PLAP) in ovarian cancer has been used in three ways by the Bristol University Department of Obstetrics & Gynaecology. First, in an indirect immunoperoxidase technique, NDOG2 demonstrated positive standing in 64% of 56 ovarian carcinomas as well as in 25% of 44 benign tumours. The majority of these positive tumours were serous cystadenocarcinomas or serous cystadenomas and there was considerable variation in the expression of this antigen from tumour to tumour. NDOG2 was also used as the basis of two serum assays and, when labelled with 123-iodine (123I), in radioimmunoscintigraphy (RIS) to monitor patients' response to therapy. The first serum assay measures the enzymic activity of PLAP and the second recognizes the antigenicity of the molecules. Assay 2 proved more useful in that it predicted the course of the disease in 45% of patients followed up, whereas Assay 1 was only of use in 25% of cases. RIS proved to be a useful imaging technique and was at least as sensitive as conventional imaging techniques. The common causes of false-positive and false-negative results are described.

Alkaline Phosphatase↗

Immunohistology of normal and ovarian cancer tissue with a monoclonal antibody to placental alkaline phosphatase.

A monoclonal antibody, designated NDOG2, has been shown to react with placental alkaline phosphatase. It does not bind to liver, kidney, bone, or intestinal alkaline phosphatase enzymes and has shown a positive reaction with all of over 50 placentae. Immunohistological studies have shown (a) a reaction with respiratory bronchiolar epithelium of lung, endocervical gland epithelium, the epithelium of fallopian tube, and certain reticular cells in the thymic medulla; (b) no detectable staining with ten other normal tissues including testis and tonsil; and (c) a significant reaction with nine of 13 ovarian cystadenocarcinomas and little or no staining with four malignant ovarian tumors of other histopathological types. The NDOG2 antibody may be of value as a marker in patients with ovarian cystadenocarcinoma.

Adult↗