Hormonal profiles and estrogen receptors in Egyptian female breast cancer patients.

AIMS AND BACKGROUND: Hormones are considered to be an important factor in the etiology of breast cancer. Serum hormonal profiles of premenopausal and postmenopausal breast cancer patients as well as estrogen receptor (ER) concentrations in breast cancer tissues were examined in an attempt to establish a possible association between hormones and breast cancer risk and to elucidate the biological features of the disease among Egyptian female patients. METHODS: Levels of estradiol (E2), testosterone (T), progesterone (P), LH, FSH, prolactin, T3, T4 and TSH were measured by highly specific radioimmunoassays in the sera of women with breast cancer and compared to those of control subjects. ER concentrations in breast tumor tissues were measured using 125I-radioreceptor assay. RESULTS: Levels of T and prolactin showed a significant increase in both premenopausal and postmenopausal patients. E2 and P levels were significantly increased in follicular premenopausal and postmenopausal patients. Luteal E2 showed non-significant changes, whereas the luteal P level was significantly decreased. No significant alterations were found in the levels of serum LH, FSH, T3, T4 and TSH either in premenopausal or postmenopausal patients. Higher levels of ER were found in the tumors of postmenopausal than in those of premenopausal patients. A positive correlation was found between levels of ER and age of the patients (r = 0.35), whereas a negative correlation was observed between ER and serum E2 (r = -0.26). CONCLUSIONS: This study provides evidence of an association between high levels of serum E2 and T and increased risk of breast cancer in postmenopausal women. Abnormalities in serum P and prolactin are probably associated with a breast cancer risk and ER may be considered as a biochemical marker for breast cancer development.

Effect of platelet encapsulated Iloprost on platelet aggregation and adhesion to collagen and injured blood vessels in vitro.

A novel approach to site-directed delivery of drugs in vivo using blood platelets as carrier vehicles is being investigated. In this context some initial studies are reported on the effect of platelet encapsulated anti-platelet drugs on platelet aggregation and adhesion to fibrillar collagen and injured arteries in vitro. The stable prostacyclin analogue Iloprost has been encapsulated within human and pig platelets by high voltage electroporation (Hughes and Crawford 1989 and 1990). After resealing the platelets, the packaged drug has a negligible effect upon platelet adhesion to a surface of fibrillar collagen or to damaged aorta (stripped to the tunica media to simulate deep injury). The rate of platelet recruitment to the collagen shows no dose dependency with respect to intracellular Iloprost concentrations. After high Iloprost loading, as few as 2% drug loaded platelets in a mixture with control (sham encapsulated) platelets, inhibit agonist-induced platelet aggregation > 50%. The prior deposition of a "lawn" of Iloprost-loaded platelets onto fibrillar collagen or damaged aorta has a substantial inhibitory effect (50-70%) upon the secondary recruitment of normal platelets compared with recruitment to a "lawn" of normal platelets. This inhibition of secondary recruitment occurs even in the presence of a platelet activator. If reduction of platelet recruitment to a vessel wall lesion results in a decrease in the local concentration of platelet granule-derived smooth muscle cell chemotactic and proliferative factors, this site-directed drug delivery may well have application for the prevention of restenosis following balloon angioplasty procedures.

Development of a direct [125I]radioimmunoassay for serum levels of 17-hydroxyprogesterone.

We describe a direct, rapid, sensitive and highly specific radioimmunoassay for determining serum levels of 17-hydroxyprogesterone. It is based on the use of highly specific sheep antiserum, 125I-labelled tracer, dextran-coated charcoal to separate the antibody bound and free fractions, and sodium salicylate to eliminate interference from endogenous binding proteins in serum. Intra- and interassay coefficients of variation are less than 8% and recovery is satisfactory. Sensitivity is 3.5 fmol per assay tube (0.14 nmol/l). Results correlate closely with those of an established technique using 3H-labelled steroid after initial solvent extraction and column chromatography of samples (y = 1.02x - 0.16; r = 0.998). The values found for serum from normal adult subjects ranged from 1.0 to 12.1 nmol/l while those from treated and untreated patients with congenital adrenal hyperplasia due to 21-hydroxylase deficiency were 1.4-18.4 and 27.3-650 nmol/l, respectively.

Comparison of separation techniques in radioimmunoassays for 17-hydroxyprogesterone.

Separation techniques have been studied in the development of a direct radioimmunoassay to determine levels of 17-hydroxyprogesterone in serum. The same highly specific sheep antiserum was used throughout, together with the same amount of 125I-labelled 17-hydroxyprogesterone to which was added sodium salicylate to eliminate interference by endogenous binding proteins in serum samples. In one approach, dextran-coated charcoal was employed to adsorb the free fraction and, in another, the antibodies were covalently coupled to magnetisable particles. The antiserum was also adsorbed to assay tubes either directly or indirectly through second (double) antibodies. Analytical recovery and specificity were similar irrespective of the separation technique as was the correlation with results obtained by a reference assay. Levels of 17-hydroxyprogesterone in sera from normal adults and from treated and untreated patients with congenital adrenal hyperplasia due to 21-hydroxylase deficiency were also similar. However, the assay employing dextran-coated charcoal for separation showed the best precision and resulted in the greatest sensitivity, while the use of antibodies adsorbed indirectly to assay tubes was superior in terms of practicability.

Development of a direct fluoroimmunoassay for serum levels of 17-hydroxyprogesterone.

A direct, rapid and highly specific fluoroimmunoassay for determining serum levels of 17-hydroxyprogesterone has been developed. It is based on the use of a sheep antiserum covalently coupled to magnetisable particles and fluorescein-labelled steroid. Sodium salicylate is employed to eliminate interference from endogenous binding proteins in serum. The sensitivity of 0.5 nmol/L is adequate for clinical purposes. Analytical recovery, linearity and precision are satisfactory and the results obtained correlate closely with those of an established radioimmuno-assay using 3H-labelled steroid and the same antiserum after initial sample extraction and chromatography. The values found for serum from normal adult subjects ranged from 1.0 to 12.6 nmol/L while those from treated and untreated patients with congenital adrenal hyperplasia due to 21-hydroxylase deficiency were 1.5 to 19.0 and 28.0 to 655 nmol/L, respectively.

The production and characterisation of antisera to 17-hydroxyprogesterone.

Sheep were immunised with 11-deoxycortisol-21-hemisuccinate-bovine serum albumin (11-deoxycortisol-21-HS-BSA) or with 17-hydroxyprogesterone-7 alpha-carboxyethyl thioether-keyhole limpet haemocyanin (17-OHP-7 alpha-CETE-KLH) or with 17-OHP-3-(O-carboxymethyl)oxime-KLH (17-OHP-3-CMO-KLH). The resultant antisera were assessed using [3H]17-OHP and dextran-coated charcoal to separate the antibody bound and free fractions. All sheep produced antisera with an apparent affinity constant of from 1.4 to 6.6 X 10(9) 1/mol. Those raised against 11-deoxycortisol-21-HS-BSA had titres ranging from 1:12,000 to 1:78,000 but showed significant cross-reactivity with many of the steroids tested. Sheep immunised with 17-OHP-7 alpha-CETE-KLH had antisera titres of from 1:102,000 to 1:180,000 and only 17-hydroxypregnenolone cross-reacted significantly (10-20%). The best antisera were raised in sheep immunised with 17-OHP-3-CMO-KLH. Titres ranged from 1:168,000 to 1:390,000 and there were about 8 g/l of specific antibodies which cross-reacted 5.7% or less with 17-hydroxypregnenolone, and less than 0.5% with progesterone, 11-deoxycortisol and the other steroids studied. The antisera to 17-OHP-3-CMO-KLH were further assessed using [125I]17-OHP; titres ranged from 1:5,700,000 to 1:18,000,000 with affinity constants of from 1.67 to 2.5 X 10(10) 1/mol. They showed minimal or no cross-reactivity with the steroids studied. Reimmunisation after an 8-month interval produced antisera with a higher affinity constant and even lower cross-reactivity with other steroids.