Biomedical subjects

J Isola

Publications and source records attributed to J Isola.

116 records · Page 7Linked to original sources

PubMed1988

Monoclonal-antibody-based noncompetitive avidin-biotin assay for lutropin in urine.

This noncompetitive avidin-biotin assay for lutropin (LH) in urine is based on the use of solid-phase, monoclonal antibodies, avidin-biotin binding, and enzyme label. The detection limit for LH is 0.5 int. unit/L. Performance time is 2 h. Intra- and interassay CVs were 4.2% and 6.2%, respectively. The assay is more specific for intact LH than are RIAs, and the results are unambiguous as compared with those by RIAs. LH is stable for a week in refrigerated urine; thus urine is a convenient sample material in follow-up studies for clinical ovulation timing. This rapid and sensitive nonisotopic LH assay avoids the disadvantages of blood samples. The assay provides clinically relevant predictions of ovulation timing from the amount of hormone measured in a 3-h urine specimen.

Adult↗

PubMed1987

Immunoelectron microscopic localization of progesterone receptor in the chick oviduct.

A peroxidase-anti-peroxidase (PAP) method using polyclonal anti-PR antibodies was used to localize progesterone receptor (PR) electron microscopically in the chick oviduct. The immunoreaction precipitate indicating PR was localized inside the nuclei of epithelial, glandular and stromal cells. In the estrogen withdrawn oviduct cytoplasmic immunoreaction precipitate was not seen. Inside the nucleus unoccupied PR was localized mainly like the heterochromatin. As visualized by the PAP technique, the localization of PR was not systematically changed after progesterone administration. In conclusion, we suggest that progesterone receptor in the chick oviduct is an intranuclear protein.

Animals↗

PubMed1987

Immunocytochemical localization of progesterone receptor in the chick ovary.

The distribution of progesterone receptor (PR) in the chick ovary was studied using light- and electron-microscopic immunocytochemical methods. With the light microscopic technique, PR was observed in the germinal epithelium cells of estrogen-treated and estrogen-untreated immature chicks. With the preembedding immunocytochemical technique, which proved to be more sensitive than immunohistochemistry using paraffin sections, the germinal epithelium and also part of the thecal and stromal cells were stained when immature chicks were not treated with estrogen. After estrogen treatment, the number of PR-positive stromal and thecal cells increased, as did the immunostaining intensity in their nuclei. The granulosa cells were PR-positive only after estrogen treatment. In the ovary of laying hens, the most intense staining for PR was localized in the germinal epithelium. PR was also present in the thecal, stromal, and granulosa cells. At the subcellular level, PR was detected only in the cell nuclei, indicating that ovarian PR is intranuclear independent of the presence of progesterone. In conclusion, immunocytochemical methods proved to be suitable for studying steroid hormone receptors in steroid-producing tissues (e.g. the ovary), because excess endogenous hormones do not affect detection of the receptor with the antibody as they do detection with labeled ligands. Immunocytochemically, the germinal epithelium, stromal, thecal, and granulosa cells of the laying hen ovary were shown to be target cells for progesterone. The inducibility of PR by estrogen in the thecal, stromal, and granulosa cells suggests that these cell types are also sensitive to estrogen.

Animals↗

PubMed1986

Nuclear origin of progesterone receptor of the chick oviduct cytosol. An immunoelectron microscopic study.

Progesterone receptor (PR) was studied immunoelectron microscopically from fixed vibratome sections of the chick oviduct and biochemically from the fractionated oviduct homogenate. Immunoelectron microscopically both unoccupied and occupied PR were localized inside the nuclei. Only a few cells showed PR immunoreactivity in the endoplasmic reticulum which probably represents newly synthetized PR. Biochemically unoccupied PR was in the cytosol fraction. The cytosol and nuclear PR as well as the non-transformed 8S-form and the transformed 4S-forms of cytosol PR were recognized by the anti-PR antibody (IgG-RB). The lack of PR immunostaining in the cytoplasm is therefore not due to lack of recognition by IgG-RB. We propose that in the chick oviduct progesterone receptor is a nuclear protein but synthetized in the endoplasmic reticulum.

Animals↗

PubMed1985

Progesterone receptor in the chick bursa of fabricius: characterization and immunohistochemical localization.

A high affinity progesterone-binding site was studied in the chick bursa of Fabricius. The dissociation constant for progesterone was 1.4 nM, and the concentration of progesterone-binding sites increased with estradiol treatment. In estradiol-treated bursas, the receptor concentration was about 240 fmol/mg protein. The binding site was specific for progestins, with the following order of affinities: ORG 2058 greater than progesterone greater than promegestone. Androgens, dexamethasone, and estradiol were weak competitors for progesterone binding in the bursa cytosols from estradiol-treated chicks. Immunoglobulin G fraction of antiserum (immunoglobulin G-RB) raised in rabbit against the B-subunit of chick oviduct progesterone receptor (PR) was used for an immunohistochemical study. The PR was found only in the interfollicular cells, which were most probably nonlymphoid cells. Staining was localized exclusively in the elongated nuclei of these cells. No staining was seen in the bursal epithelium or inside the lymphoid follicles. The results indicate that the interfollicular cells of the bursa contain specific PRs which are under estrogen regulation as in the oviduct. Thus, these cells might be under direct progesterone regulation.

Animals↗

PubMed1984

Augmentation of progesterone receptor concentration by progesterone and estrogen treatments in the chick oviduct.

Cytosol receptors for progesterone in the chick oviduct were measured by charcoal-adsorption assay by using ORG 2058 as a ligand after long-term administration of progesterone and diethylstilbestrol (DES). Steroid administration was carried out by using daily injections or silastic capsules. DES treatment increased the progesterone receptor concentration (from 11500 to 21500 sites per cell, day 14). Progesterone also augmented the concentration of its own receptors (from 11500 to 29000 sites per cell, day 14). In the experiments with capsule administration the same trend was seen. This indicates that both diethylstilbestrol and progesterone are able to increase the concentration of progesterone specific cytosol receptors in the non-differentiated chick oviduct.

Animals↗

PubMedDate not supplied

Accumulation of p53 protein correlates with tumour proliferative activity in EBV positive Burkitt's lymphoma.

p53 tumour suppressor gene is often found mutated in Burkitt's lymphoma (BL) cell lines and tumours. We analysed 35 BL tumours for the accumulation of p53 protein, and correlated the results with DNA flow cytometric data on the proliferative activity (SPF), and data on the presence or absence of Epstein-Barr virus (EBV) DNA. More than one-third (37 per cent) of the tumours showed accumulation of p53, which was considered to be consistent with mutation of the p53 gene. Tumours that were positive both for EBV DNA and p53 had significantly higher mean SPF than corresponding EBV DNA negative and/or p53 negative tumours. The proportions of tumour cells with accumulation of p53 appeared to correlate with tumour SPF only in EBV DNA positive BLs. However, there was no apparent association between accumulation of p53 and the presence or absence of EBV DNA. These findings are suggestive of multiple pathways in BL tumour progression.

Adolescent↗

PubMedDate not supplied

Expression of C-KIT and HER-2 tyrosine kinase receptors in poor-prognosis breast cancer.

BACKGROUND: This study investigated the expression of C-KIT and HER-2 receptors and their correlation with histopathological markers of cell proliferation, differentiation and apoptosis in poor-prognosis breast cancer. PATIENTS AND METHODS: Formalin-embedded histopathological samples from forty patients with progressive metastatic breast cancer were reanalyzed to determine HER-2 expression by immunohistochemistry (ICH) and chromogenic in situ hybridization (CISH). C-KIT receptor expression, p53, Bcl-2 and Ki-67 were determined by immunohistochemistry. RESULTS: The mean p53 score was 18.03 (SD 30.69), that of Bcl-2 was 38.13 (39.25) and Ki-67 was 5.8 (SD 9.23), respectively. HER-2 expression was positive in 35% of patients by ICH and in 25% by CISH. C-KIT receptor staining was positive in 82% of the patients. A significant association was observed between HER-2-positive score in ICH and poorly-differentiated histology (p=0.03), negative Er/Pr status (p=0.04) and Bcl-2 expression (p=0.003). With CISH-determined HER-2, the corresponding p values were 0.07, 0.053, and 0.002, respectively. No correlation was found between HER-2 or C-KIT expression (p=0.456). CONCLUSION: CISH and ICH determination of HER-2 correlate similarly to hormone receptor status and Bcl-2 expression in breast cancer. C-KIT expression was commonly present and did not correlate to other prognosticators in poor-prognosis breast cancer.

Adult↗