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Biomedical subjects

A Norgren

Publications and source records attributed to A Norgren.

At least 19 recordsLinked to original sources
PubMed1998

Sex steroid receptors in human myometrium and fibroids: changes during the menstrual cycle and gonadotropin-releasing hormone treatment.

The content of estrogen and progesterone receptors (ER, PR) is higher in fibroid tissue than in homologous myometrium, and both receptors seem to be regulated by the levels of circulating sex steroids. Myometrial and fibroid tissues were recovered from women undergoing gynecological operations during different phases of the menstrual cycle and during treatment with an analogue of GnRH (GnRHa). Contents of ER and PR in the tissue cytosol were determined by enzyme immunoassay. The ER levels were significantly higher in fibroid tissue than in homologous myometrium in all the endocrine conditions. During the secretory phase, when luteal progesterone production is prominent, the ER levels in the myometrium and fibroids were lower than during the proliferative phase. During GnRHa treatment, the ER levels in both tissues were similar to those in the proliferative phase but significantly higher than in the secretory phase. The PR levels were also significantly higher in fibroids than in myometrium in all the different endocrine conditions. In both tissues, the PR levels were lower in the secretory phase and during GnRHa treatment, compared with the proliferative phase. Our data suggest that, in these categories of women, both ER and PR are overexpressed in fibroid tissue. Apparently, high progesterone levels down-regulate the ER in both fibroids and myometrium, whereas estrogen mediates the up-regulation of the PR during the proliferative phase. Increased knowledge about the mechanisms by which sex steroids regulate their own receptors in uterine tissues might provide a basis for development of new treatment strategies for women with fibroid disease.

Adult↗
PubMed1997

Mammographic screening for breast cancer. What cancers do we find?

The aim of this study was to compare lymph node involvement of breast cancer cases detected at mammography screening with clinically-detected cases. During a 3-year period, 273 primary breast cancers were detected in a population-based screening programme, and 149 primary breast cancers were diagnosed clinically. Lymph node involvement was evaluated in univariate and multivariate logistic regression models correcting for tumour size, histological grade, steroid receptor status and DNA-ploidy. Patients with screen-detected cancers had a low relative risk of having lymph node metastases (univariate, OR = 0.31; 95% confidence interval = 0.19-0.52). In the multivariate logistic regression model, the relative risk was halved (OR = 0.47; 0.28-0.78). The reduced risk was more pronounced for women younger than 50 years of age compared to older women. The risk for screen-detected cases of having lymph node metastases at diagnosis was statistically significantly lower than for clinically-detected cases. The marked reduction, even when correcting for tumour size, makes it less likely that factors such as detection of clinically innocent tumours, length bias sampling or clinical symptoms related to axillary metastases can explain the whole difference. The results indicate at least part of the effect may be explained by tumour progression in the late preclinical detectable phase.

Adult↗
PubMed1993

Localization of steroid hormone receptors in the pelvic muscles.

After the menopause the pelvic floor becomes progressively weaker, one consequence of which is the increasing incidence of prolapse and urinary incontinence. It is plausible that the reduction in estrogen levels postmenopausally is an etiological factor in these problems. For the pelvic floor muscles to be considered as target organs for estrogen, demonstration of the presence of estrogen receptors is required. The present study aims to confirm previous findings of estrogen and progesterone receptors in the levator ani muscle, and to further localize them histologically. In seven women biopsies from the levator ani muscle were taken and analyzed immunohistologically with monoclonal antibodies for estrogen and progesterone receptors. The receptors were detected in the nuclei of connective tissue cells and striated muscle cells. These findings provide a scientific basis for a possible beneficial effect of estrogen therapy, as a complement to other therapies, in prolapse and urinary incontinence.

Adult↗
PubMed1993

The round ligament: a target organ for steroid hormones.

Samples of the round ligament from pre- and post-menopausal women were analyzed immunohistochemically for estrogen and progesterone receptors. The steroid hormone receptors were localized in the smooth muscle cell nuclei, with stronger staining for progesterone receptors and somewhat weaker for estrogen receptors. Our findings support the view that the round ligament is a target organ influenced by hormones, which has implications for the changes in the ligament during pregnancy and pre- and postmenopausally.

Adult↗
PubMed1990

Steroid hormone receptors in pelvic muscles and ligaments in women.

Using monoclonal antibody assay techniques estrogen receptors (ER) and progesterone receptors (PgR) were quantitated in female pelvic floor muscles, urogenital ligaments and uterus (myometrium). Receptors were detected in all these structures. In addition qualitative assessment showed distinct nuclear staining in the same structures. ER and PgR were not found in the musculus rectus abdominis with either method. The findings provide a rationale for estrogen treatment in women with urogenital disorders.

Adult↗
PubMed1990

Estrogen and progesterone receptor analyses in more than 4,000 human breast cancer samples. A study with special reference to age at diagnosis and stability of analyses. Southern Swedish Breast Cancer Study Group.

Estrogen (ER) and progesterone receptors (PgR) were measured in the same laboratory in more than 4,000 breast cancer biopsy samples obtained from 15 different hospitals during ten years. ER was measured with isoelectric focusing and PgR with the dextran-coated charcoal method and Scatchard analysis. The distribution pattern for both ER and PgR was during this time period and for the different hospitals rather similar indicating a good stability of the analytical methods. ER concentration was positively correlated with patient age, with a higher percentage of positive samples and higher concentrations in patients greater than or equal to 50 years of age compared with patients less than 50 years. PgR concentration increased with age for patients under 50 years, but a considerable reduction of PgR concentration and of the proportion of positive samples was seen in patients between 50 and 59 years of age. Above this age the PgR concentration again increased with increasing age. The PgR/ER ratio and the proportion of ER- PgR+ samples were higher in patients under 50 years compared to older patients. ER and PgR values decreased during tamoxifen treatment, during pregnancy and after preoperative radiotherapy. Wet weight, DNA and protein were compared as reference parameters for the expression of ER and PgR concentrations. Strong correlations were obtained suggesting that similar information can be obtained with either of these reference parameters.

Adult↗
PubMed1989

Prognostic value of steroid receptor concentration and flow cytometrical DNA measurements in stage I-II endometrial carcinoma.

In order to make a more individualized therapy possible in endometrial cancer we investigated the prognostic ability of steroid receptor concentration and the DNA content in individual cells as measured by flow cytometry. We found that although the steroid receptor concentration was a prognostic parameter, the DNA content proved to be a better parameter than all other known prognostic parameters in endometrial carcinomas stage I-II. Thus it was possible to divide the tumors into three groups; 1) diploid tumors with a relapse rate of 6%, 2) aneuploid tumors with a high estradiol receptor concentration and without myometrial invasion of more than the inner third, and with a relapse rate of 18%, 3) aneuploid tumors, poorly differentiated with a low estradiol receptor concentration or myometrial invasion and with a relapse rate of 44%.

Adult↗
PubMed1988

Prognostic significance of estrogen and progesterone receptors in stage II breast cancer.

Estrogen (ER) and progesterone receptors (PgR) were evaluated in samples from primary tumors in 539 patients with stage II breast cancer participating in a randomized multicenter controlled clinical trial on adjuvant therapy. At the cut-off points of 10 fmol ER/mg protein and 30 fmol PgR/mg protein, no significant difference in recurrence-free survival (RFS) existed between premenopausal patients with receptor-positive and negative tumors, respectively. After recurrence, premenopausal patients with receptor-positive tumors had a significant longer survival than patients with receptor-negative tumors. In postmenopausal patients not treated with adjuvant tamoxifen, no correlations between RFS and receptor status were found. Patients with ER+ tumors survived longer than patients with ER-tumors. In postmenopausal patients treated with adjuvant tamoxifen, highly significant differences in RFS and in survival were observed when receptor-positive patients were compared with receptor-negative patients. No differences in survival after recurrence were registered among these patients.

Breast Neoplasms↗
PubMed1984

Plasma steroid hormones, cytosol receptors, and thymidine incorporation rate in endometrial carcinoma.

Histopathologically evaluated endometrial carcinomas were analyzed for the presence of estradiol and progesterone receptors and for tumor thymidine incorporation rate. Plasma estradiol and progesterone concentrations were also measured. With the use of an improved assay, all endometrial carcinomas were found to contain estradiol receptors; 81 of 92 (88%) contained measurable concentrations of progesterone receptors. The concentrations of both receptors were positively correlated to the degree of differentiation. The moderately and poorly differentiated tumours could be further divided into subgroups with low and high concentrations of receptors, which might be a reflection of an independent biologic characteristic of a tumor. These subgroups did not differ in any of the other variables studied, including the age of the patients. The plasma concentrations of estradiol showed a positive correlation to the degree of differentiation and to the concentration of both receptors. It is suggested that improved analyses of estradiol and progesterone receptors in endometrial carcinomas may add information to the conventional histopathologic and clinical classification which will be of significant value in the proper treatment of the disease.

Aged↗
PubMed1978

A sequential extraction method for RNA from rabbit liver.

When naphthalene-1,5-disulfonate (NDS) and phenol-cresol were used for extraction of rRNA from rabbit liver approximately 80% of the extractable RNA was recovered. By subsequent treatment of the resulting insoluble interface with 4-aminosalicylate and triisopropylnaphthalenesulfonate (PAS-TIPNS) the remaining RNA was extracted. Subcellular fractionation and polyacrylamide gel electrophoresis or sucrose density gradient analysis showed that this last fraction contrained 28s RNA from membrane-bound polysomes. Applying the sequential extraction method for isolation of poly(A)-containing mRNA showed that only a minor part of that RNA was extracted with NDS while the rest was recovered by PAS-TIPNS treatment of the interface. Thus, a purification of poly(A)-containing mRNA was possible when the sequential extraction method was used.

Aminosalicylic Acids↗
PubMed1975

Hybridization of polyuridylic acid to human DNA immobilized onto nitrocellulose filters.

The level of deoxyadenylate (da) regions in human DNA was estimated from formation of poly(U)-poly(da) triplexes on nitrocellulose filters that were RNAase resistant. The (dA) rich sequences were determined following mild ribonuclease treatment of the poly(U)-DNA hybrids (5 mug/ml at 25 degreesC for 30 min), where as exhaustive ribonuclease treatment (5 mug/ml at 25 degrees C for 6 hr) estimated the more (dA) pure sequences. The level of (dA) rich regions was 0.39% of the DNA and for the more (dA) pure regions it was 0.07%. The (dA) regions were widely distributed throughout human DNA regardless of base composition or sequence repetition. However, a concentration of (dA) regions into main band CsC1 gradient fractions of DNA and into repeated DNA was observed.

Adenine Nucleotides↗