Biomedical subjects

A Borg

Publications and source records attributed to A Borg.

172 records · Page 10Linked to original sources

PubMedDate not supplied

Enzyme immunoassay of progesterone receptor in cancerous and normal endometrial tissue. A comparison with dextran coated charcoal method.

Enzyme immunoassay (EIA) was compared with the dextran-coated charcoal method and Scatchard analysis for the measurement of progesterone receptor (PgR) in cancerous and normal endometrial samples. A highly significant correlation was obtained between the two assays in both types of tissue (rs = 0.77 and 0.91, respectively; p less than 0.001). The measurable amount of PgR was usually higher with EIA (mean increase 90 and 100 per cent, respectively). EIA is suggested to be a suitable method for PgR measurement in endometrial tissue (normal and cancerous) and can also be used for analysis of PgR in the nuclear fraction.

Biomarkers, Tumor↗

PubMedDate not supplied

Estrogen receptor and binding site for estramustine in metastatic malignant melanoma.

Enzyme immuno assay (EIA) of estrogen receptor (ER) has confirmed the results of earlier investigations using steroid binding techniques, namely that ER is present at very low concentrations in samples from metastatic melanoma. Thirty-four of 61 samples (56%) were ER positive with EIA. The corresponding figures using isoelectric focusing (IF) for the steroid binding assay were 16 of these 61 samples (26%). The difference between the methods may be due to difficulties in the interpretation of analytical results for IF at low ER concentration levels or to interference from other 3H-estradiol binding components. Estramustine binding site (EMBS) has been found in samples from 15 of 77 patients (20%) with IF in polyacrylamide gels. Estramustine is, together with estramustine, the cytotoxic metabolite of estramustine phosphate (Estracyt). In analogy to the previously suggested therapeutic significance of estramustine binding protein in the treatment of prostatic cancer, the clinical importance of estramustine phosphate should also be studied in metastatic malignant melanoma in correlation with EMBS status.

Adolescent↗

PubMedDate not supplied

Early oral contraceptive use as a prognostic factor in breast cancer.

The survival of 193 premenopausal breast cancer patients was investigated in relation to their history of early use of oral contraceptives. The women were born in 1939 or later and diagnosed in the southern health care region of Sweden. Women, who had started their oral contraceptive use (OC-use) before 20 years of age had a significantly lower survival rate as compared with those who had never used OC and late users (p = 0.02 and = 0.04 respectively, generalized Wilcoxon test). For women who started OC-use between 20 to 25 years of age, a tendency for a shorter survival was seen in comparison with women who had never used OC (p = 0.18). For all patients simultaneously, the relative risk adjusted for age at diagnosis increased for earlier OC-start. When only stages II and III were considered in a stratified multivariate model, a significantly elevated risk was seen for early users of OC irrespective of age or of adjuvant treatment given. The estrogen and progesterone receptor concentrations of the primary tumor were significantly lower among early users (p = 0.001 and p = 0.05 respectively).

Age Factors↗

PubMedDate not supplied

Permanent alterations induced in plasma prolactin and estrogen receptor concentration in benign and malignant tissue of women who started oral contraceptive use at an early age.

In 65 young women undergoing curettage for benign uterine disorders a significant relationship was found between early oral contraceptive use (starting age less than 25 years) and a high ratio of ln plasma prolactin versus ln estrogen receptor concentration of the uterine mucosae (p less than 0.047, Mann-Whitneys U-test). Year of birth, age at menarche, age at first full term pregnancy, parity, menstrual cycle phase and duration of oral contraceptive use could not explain the results. Because similar results have previously been found for breast cancer patients using plasma prolactin and breast tumour estrogen receptor concentration, the findings indicate that early oral contraceptive use permanently alters plasma prolactin levels and estrogen receptor concentration, both in benign uterine tissue and in malignant breast tumours.

Adult↗

PubMedDate not supplied

Observations on wet weight, protein and DNA as reference for steroid receptors in malignant mammary tumours.

Estradiol and progesterone receptors were recorded together with DNA and soluble protein per unit wet weight for 235 breast cancer samples. Receptor concentration values per wet weight showed the greatest range of variation. Receptor expressed per unit wet weight, DNA or protein showed good correlation (rs greater than 0.90). In selected cases different information on receptor concentration levels may be obtained depending on the reference parameter used. An overrepresentation was found of tumours with low receptor concentrations or receptors below the level of detection in a subgroup with a low DNA content, indicating the possibility of false low receptor values in this group. High ER and PgR contents were significantly related to high level of tissue DNA. Low or high content of protein was not associated directly with low or high receptor levels. In this respect DNA is superior to wet weight and protein as reference standards for receptor concentration. Further, DNA offers the additional possibility of a rough correction for non-epithelial components of the tumours. A critical dilution of receptors, as shown by low DNA content in some homogenates, was not apparent but cannot be excluded.

Biopsy↗

PubMedDate not supplied

Antiestrogen binding sites in human breast cancer biopsies. Measurement ligand-specificity and affinity, and correlation to estrogen and progesterone receptors.

Specific binding sites for the antiestrogen tamoxifen (AEBStot), as measured with the dextran-coated charcoal technique and Scatchard analysis, were quantitated in 43 of 44 breast cancer samples (41-2,100 fmol/mg protein). In this work, AEBStot has been defined as the sum of AEBSspec and estrogen receptor (ER), AEBSspec shows a very weak positive correlation with ER, and no correlation with progesterone receptor. Tamoxifen (TAM) has a lower affinity to ER compared with one of its main metabolites, 4-OH-TAM. This may be one reason why inhibition by excess estradiol on 3H-4-OH-TAM binding was better correlated with ER content in the same sample than if 3H-TAM was the radioactive ligand. It is therefore suggested that 3H-4-OH-TAM is a better choice than 3H-TAM for measuring AEBSspec alone. A possible role of AEBSspec for the clinical effects of TAM is discussed.

Breast Neoplasms↗

PubMedDate not supplied

Improved method for assay of estradiol and progesterone receptors with special reference to breast cancer.

Isoelectric focusing of estradiol receptor (ER) and multiple point dextran-coated charcoal (DCC) technique for progesterone receptor (PgR) were adapted for assay of both receptors in the same cytosol sample. Technical improvements and increased recovery of receptors were achieved. 1.0 fmol/ml cytosol of ER may be detected; sensitivity of PgR was 5-10 fmol/ml cytosol. Quantitation of ER was made in 414 (95%) out of 434 consecutive breast cancers. Inclusion of isoelectric focusing records showing only qualitative indication for presence of ER resulted in 98% ER containing tumours, supporting the aspect that strictly ER negative tumours are a rarity. Implications for therapy in disseminated disease are discussed.

Animals↗

PubMedDate not supplied

A comparison of two steroid receptor assays in breast cancer: dextran coated charcoal and isoelectric focusing.

The multiple point dextran coated charcoal technique with Scatchard analysis (DCC) and isoelectric focusing on polyacrylamide gels (IF) were compared with regard to steroid receptor recovery, amount of tissue necessary, and expenses of assay. Quantitative correlations showed that when using DCC as compared to IF, estradiol receptor (ER) recovery increased two and progesterone receptor (PgR) recovery increased four times. In spite of lower recovery, IF may be a good alternative to DCC for routine ER assay since a small amount of tissue is required and the IF assay is easy to evaluate. The two assays were approximately equal in expense.

Animals↗

PubMedDate not supplied

Estrogen and progesterone receptors in melanoma metastases with special reference to analytical methods and prognosis.

Fifty-one tumor biopsies from 33 patients with metastatic melanoma were assessed for estrogen receptor (ER) content, and 46 of these for progesterone receptor (PgR) content in the cytoplasm. ER posivity (above 0.2 fmol/mg protein), as measured with isoelectric focusing on polyacrylamide gels, was found in 23 (70%) of the patients (range 0.2 - 14 fmol/mg protein). With a reference limit of 2 fmol ER/mg protein, 12 patients were positive (36%). PgR was analysed with the dextran coated charcoal technique and no sample demonstrated any positivity with certainty. The ER content was related to clinical prognostic factors without any significant correlation independent of reference limit used. A correlation to survival can not be excluded with ER values above 2 fmol/mg. Pertinent data are given regarding the technique used in comparison with others.

Charcoal↗

PubMedDate not supplied

Correlation between estradiol-17 beta and progesterone cytosol receptor concentration, histologic differentiation and 3H-thymidine incorporation in endometrial carcinoma.

Women treated with estrogen exhibit a higher risk of developing endometrial cancer. steroid hormones exert their effects on target tissue through specific cytosol receptor protein. Knowledge of this steroid receptor concentration in endometrial carcinoma might facilitate the treatment of recurrences. We have compared the concentrations of endometrial estrogen and progesterone cytosol receptors with the histologic grade of endometrial carcinoma as well as the rate of 3H-thymidine incorporation. We found a significant difference in receptor concentration between well-moderately differentiated tumours and poorly differentiated ones. No correlation was found between 3H-thymidine incorporation rate and differentiation. A positive correlation between thymidine incorporation rate and progesterone receptor concentration was noticed. The concentration of receptors varies within a wide range of each group of differentiation; thus 23% and 4% of the poorly differentiated tumours had higher concentration of estradiol and progesterone receptors respectively than the median values for well differentiated tumours.

Cytosol↗