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E Ronchi

Publications and source records attributed to E Ronchi.

At least 19 recordsLinked to original sources
PubMed1992

Immunocytochemical study of GnRH and GnRH-associated peptide in male Syrian hamsters as a function of photoperiod and gonadal alterations.

Hypothalamic luteinizing-hormone-releasing hormone (GnRH) and gonadotropin-releasing-hormone-associated peptide (GAP) biosynthesis and storage were estimated by immunocytochemistry in male golden hamsters maintained in different photoperiods. Intact or castrated male hamsters with subcutaneously inserted testosterone implants were exposed to long-day (14:10) or short-day photoperiods (10:14) for 4-8 weeks. Exposure to short photoperiod for 4 weeks, an interval characterized by a suppression of gonadotropin secretion but not gonadal regression, was associated with an increase in the number of GnRH- and GAP-immunoreactive cells in the diagonal band of Broca/medial septum. Furthermore, morphometric analysis revealed that these animals displayed significantly more GnRH but not GAP immunoreactivity in the median eminence as opposed to hamsters exposed to long-day photoperiods. In additional studies, gonadally regressed hamsters exposed to short day lengths for 8 weeks had equal numbers of GnRH cells as did the long-day controls. These patterns suggest that reproductive quiescence in golden hamsters is not the result of depletions of neuronal GnRH stores available for secretion.

Animals↗
PubMed1992

Steady state analysis of hypothalamic GnRH mRNA levels in male Syrian hamsters: influences of photoperiod and androgen.

An in situ hybridization assay, utilizing a free floating technique was used to estimate the steady state levels of hypothalamic luteinizing hormone-releasing hormone (GnRH) mRNA levels in the brains of male golden hamsters maintained in different photoperiods. In situ histochemistry was performed using a 32P-labelled 66-nucleotide long oligomer complementary to the sequence of the human GnRH mRNA coding region. The oligonucleotide hybridized specifically to mRNA encoding the GnRH precursor as suggested by the distribution of labelled neurons and as shown by an RNAse protection assay on septal and preoptic-hypothalamic mRNA from gonadally regressed hamsters. To test the hypothesis that short-day photoperiods reduce GnRH synthesis, intact male hamsters or castrated males bearing subcutaneously inserted testosterone implants were exposed to long-day (14 h light:10 h dark) or short-day (10 h light 14 h dark) photoperiods for 4 weeks. Exposure to short day lengths never caused a decrease in GnRH expressing neurons and actually was associated with an increase in the number of radiolabelled cells specifically in the diagonal band of Broca/medial septum in the gonadally intact group. The mean number of grains per labelled cell for the short day animals similarly was not reduced from that seen in long day animals. The results are consistent with previous studies on photoperiod and GnRH content in the same brain regions and support the notion that the suppression of the synthesis of GnRH does not accompany the low levels of LH secretion observed during the early stages of reproductive quiescence in this species.

Animals↗
PubMed1991

[Absorption of short-acting insulin mixed with different slow-release formulations].

Several authors point to a different action of soluble insulin when mixed with a lente formulation containing either protamine or zinc. We evaluated glucose and insulin profiles in 17 type I diabetics, every one of whom was given what was considered the optimal amount of insulin twenty minutes before a standard evening meal. The patients were studied on two occasions, one week apart. According to a randomized sequence, those who received first the protamine-soluble mixture, took the Zn-soluble combination after one week and vice-versa. At the same time, we determined anti-insulin antibodies in order to rule out any different immunological interference, in the two moments of the study. Our results confirm that protamine-insulin given together with regular shows a serum insulin peak which is earlier and higher than that obtained with the corresponding mixture of Zn-insulin and regular (ANOVA: F = 5, 96; p = 0.02); blood glucose levels were lower with the former regimen, even though the difference did not reach statistical significance. Our conclusion is that Zn-containing insulin partly inactivates regular insulin when administered in the same syringe, and this may have an impact on the long-term treatment of the diabetic patient.

Adult↗
PubMed1991

Expression of P-glycoprotein in breast cancer tissue and in vitro resistance to doxorubicin and vincristine.

Expression of P-glycoprotein was evaluated by C219 monoclonal antibody immunoblots in 34 previously untreated and 14 pretreated breast cancers and in benign breast lesions or histologically normal breast glands. P-glycoprotein was not detectable in the few cases of normal or benign tissue. P-glycoprotein was expressed in the 170 kD areas of 29% (10/34) of untreated and 64% (9/14) of previously treated tumours (P = 0.02). In treated tumours, high intensity expression was observed more frequently than in untreated breast cancer (40% vs. 9%). Moreover, there was a significant association between P-glycoprotein expression and in vitro resistance to doxorubicin and vincristine. Simultaneous resistance was observed in all of the P-glycoprotein positive and in only 56% of the P-glycoprotein negative tissues (P less than 0.01). Some aspects of the typical multidrug resistant phenotype, such as P-glycoprotein expression and simultaneous resistance to doxorubicin and vincristine, could be detected in small subsets of breast cancer patients. No relation between P-glycoprotein expression and the type of previous clinical treatment was observed.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1990

[Compliance and long-term prognosis in hypertensive patients. Case series in a specialized hospital outpatient service].

In this study of ambulatory patients who had their first visit at the hypertension Unit of the Ospedale San Carlo Borromeo in Milan during the years 1979-1983, we report some data regarding compliance and long-term prognosis of mild hypertension. In these 5 years, 445 mild hypertensives (mean DBP: 103.3 +/- 13.2 mmHg) came to our facilities at least once: of these, 57 (12.9%) have been in constant touch with the outpatient clinic until today; 310 (69.6%) have been lost to follow-up after less than 1 year; 78 (17.5%) had an irregular pattern of attendance with a mean length of follow-up of 3.49 +/- 1.8 years. These data indicate a less than ideal compliance especially for patients who were older, smokers, not married and with no previous pharmacological treatment at the first visit. Index of morbidity and mortality for all causes and for cardiovascular disease and blood pressure control were better, although without reaching statistical significance, in the 57 patients with the best compliance. Altogether our data point to a reevaluation of the approach to the problem of mild hypertension through specialised hospital facilities.

Adult↗
PubMed1989

Detection of the 170 kDa P-glycoprotein in neoplastic and normal tissues.

A membrane purification procedure and an immunoblotting assay have been designed to allow screening of human solid tumors for overexpression of the GP170 glycoprotein without employing a disaggregation method to obtain cell suspensions. The electrophoresed membrane proteins were probed, after Western Blotting, with the C219 monoclonal antibody and iodinated Protein A. The labeling intensity of the bands on the autoradioimmunoblots were quantified by densitometry. To test for the presence of GP170, we used membranes from the UV 2237 fibrosarcoma line and its adriamycin-resistant variant ADMR, grown in vitro or as solid tumor in mice. Membranes of human normal and tumor tissues obtained from previously untreated patients were also tested. An immunoreaction was observed in the adriamycin-resistant UV 2237 lines grown in vitro or in vivo. Quantitatively, the binding of the resistant cell line grown in vitro was higher than that observed in cells grown in mice. Bands in the GP 170 region were observed in 4/7 normal and in 7/7 tumor colon tissues and in the normal medulla from 2 patients with cancer of the renal cortex. No reaction could be found in samples from normal tissue, primary tumor or nodal metastasis from 7 patients with breast cancer.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1989

Effects of daylength on androgen metabolism and pulsatile luteinizing hormone secretion in male golden hamsters.

In an effort to understand the potential neuroendocrine mechanisms underlying photoperiodic control of fertility in seasonally breeding species, we monitored the intracellular processing and nuclear uptake of [1 alpha, 2 alpha-3H]testosterone (3H-T) within the brain-pituitary complex as well as the patterns of episodic luteinizing hormone (LH) secretion in male golden hamsters exposed to long day (14 h light:10 h dark) and short day (10 h light:14 h dark) photoperiods. Target tissue specific patterns of nuclear 3H-androgens and estrogens were observed in castrated, T-replaced hamsters exposed to long and short days for 7 weeks or longer. Significantly, 3H-T metabolism or receptor-mediated nuclear uptake in the hamsters in short days was not influenced in any manner that would explain their increased responsiveness to androgen feedback suppression of LH release. Comparable patterns of episodic LH secretion were observed in acutely catheterized hamsters castrated for 7 weeks prior to exposure to 8 weeks of long or short days. Similar patterns were also observed in animals maintained in long days and castrated 1 or 2 weeks prior to blood collection. However, such a pattern was not seen in acutely castrated hamsters maintained in the short-day photoperiod. The data suggest that steroid-independent mechanisms play an important role in suppressing gonadotropin release in short days in this species. However, such mechanisms appear to be most effective when the animals are or have recently been exposed to circulating androgens.

Androgens↗
PubMed1986

A double-labeling assay for simultaneous estimation and characterization of estrogen and progesterone receptors using radioiodinated estradiol and tritiated Org 2058.

Estrogen (ER) and progesterone receptors (PgR) appear to be a prerequisite to elicit a biologic response by a hormone-target organ. Current methodologies for analysis of these proteins (e.g., dextran-coated charcoal, DCC) in single-label assay (SLA) require relatively large amounts of tissue material, time and laboriousness. Therefore, we have developed for breast cancer tissue an improved dual-label assay (DLA) for simultaneous titration (by DCC) and/or characterization (by sedimentation properties) of ER and PgR on the same sample, using 125I-E2 and 3H-Org 2058 as tracers. The interaction of 125I-E2 with ER and plasma proteins in comparison to 3H-E2 was studied in terms of specificity, time course, affinity binding and sedimentation pattern. 125I-E2 bound the same molecular forms displayed by 3H-E2 (9 and 3S) but with lower titers (about 1.3-fold), irrespective of the technique used, and did not bind to sex hormone-binding globulin. Simultaneous detection of 125I and 3H was achieved by use of a gamma counter plus a beta counter sequentially. ER and PgR titrations with DCC in DLA were in good agreement with those obtained with SLA, in terms of titers and Ka values. An analogous result was obtained with sucrose density gradient (SDG) analysis. Both the DLA methods were highly reproducible (CV less than 8.0%). Between the rotors available for SDG, the vertical one was preferable because of the larger number of samples processed and of less perturbation of sedimenting receptor molecules. Furthermore, a biochemical application of the method is described. In conclusion, the DLA procedure, by simplifying ER and PgR estimation, makes it possible to study, even on small tumor biopsies, the molecular properties of these proteins in relation to the clinical response of the disease.

Breast Neoplasms↗
PubMed1986

Relationship between ER-ICA and conventional steroid receptor assays in human breast cancer.

We applied a new immunocytochemical assay for estrogen receptors (ER-ICA) to 82 human breast tumors. Results were correlated with cytosolic estrogen receptors (ERc) and nuclear ER (ERn) determined on the same sample respectively by the radioligand binding assay and by an ER enzyme immunoassay (ER-EIA). All ER-ICA-positive tumors contained more than 10 fmol/mg of protein of ERc and were therefore considered as ERc positive. In contrast, 15.4% of ERc-positive cases were ER-ICA negative. Comparison of ER-ICA results with ERn showed extensive agreement of negativity (92%), whereas 38% of ER-ICA-positive tumors were ER-EIA negative. However, the latter had ERc levels above the positivity threshold. Quantitative features of the immunocytochemical staining such as intensity and percentage of labelled cells, considered separately, did not reflect the amount of ERc or ERn. Cellularity was not significantly correlated with ER-ICA and biochemical results.

Breast Neoplasms↗
PubMed1986

Adjuvant medroxyprogesterone acetate and steroid hormone receptors in category M0 renal cell carcinoma. An interim report of a prospective randomized study.

From July 1, 1979 to June 30, 1983, 136 consecutive patients with category M0 renal cell cancer who had undergone transperitoneal radical nephrectomy at 5 centers entered a prospective randomized trial to compare 500 mg. adjuvant medroxyprogesterone 3 times a week for 1 year to no treatment. Sex steroid hormone receptors also were studied in the renal tumor and in the surrounding healthy parenchyma with the dextran-coated charcoal technique. After a median followup period of 3 years (range 13 to 60 months) 30 of 121 evaluable patients (24.8 per cent) experienced relapse, usually in the lung or bones. Relapses occurred in 15 of 58 evaluable patients in the adjuvant treatment group (25.8 per cent) and 15 of 63 evaluable controls (23.8 per cent). The disease recurred more frequently (35.1 per cent) in the 57 patients with no receptors in the tumor than in the 45 with at least 1 receptor (17.8 per cent). These results were independent of adjuvant therapy. After a median 3-year followup, adjuvant medroxyprogesterone acetate was of no therapeutic benefit in patients who had undergone radical nephrectomy and the side effects of the therapy were evident in more than 50 per cent of the patients.

Antineoplastic Agents↗
PubMed1986

Comparison of immunochemical and radioligand binding assays for estrogen receptors in human breast tumors.

We have compared a new enzyme immunoassay (EIA) for estrogen receptors (ER) with our conventional radioligand binding assays (multipoint dextran-coated charcoal assay for cytoplasmic ER and hydroxylapatite exchange assay for nuclear ER). Cytoplasmic ERs were measured in 76 human breast cancer specimens by EIA and by five-point Scatchard analysis. The correlation between the two assays yielded a straight line with a slope of 0.92 (r = 0.95; P less than 0.001); conversely, in 31 nuclear salt extracts, linear regression analysis of hydroxylapatite exchange assay data with EIA showed a clear correlation (r = 0.93; P less than 0.001) but a slope of 1.7, demonstrating that EIA detects more ER sites. The binding of the antibody to the cytoplasmic ER molecules was investigated by sucrose density gradient analysis, which showed that EIA recognizes both cytoplasmic forms (9 and 3S), but does not distinguish between them. Advantages and drawbacks of this method are discussed with respect to its application for routine receptor determination for clinical management of breast cancer patients.

Breast Neoplasms↗
PubMed1986

Hormone steroid receptor variation after tamoxifen administration in endometrial adenocarcinoma from postmenopausal patients.

Cytoplasmic and nuclear variations of estrogen (ER) and progesterone receptors (PgR) induced by tamoxifen (TAM) treatment were investigated in 38 postmenopausal women with endometrial carcinoma. The treatment consisted of a daily oral administration of 40 mg for 7 days. Tumor samples from each patient were withdrawn before TAM administration under hysteroscopy and at the time of hysterectomy. Cytoplasmic and nuclear receptors were respectively determined by the dextran-coated charcoal assay and the hydroxylapatite technique. In the cytoplasmic fraction no significant change in mean ER value was observed, but a statistically significant increase in PgR was found (P less than 0.001). Conversely, in the nuclear fraction PgR did not vary, but a significant increase in ER content (P less than 0.001) was observed. PgR, analyzed by sucrose density gradient after TAM, showed the same sedimentation property (9 S) as the preexisting receptor, but with a single peak profile, indicating a lower heterogeneity. Our data support the hypothesis that the mechanism of PgR synthesis is induced by the ER-TAM complex and suggest the possibility of increasing the PgR content in these patients for sequential endocrine therapy.

Adenocarcinoma↗
PubMed1985

[Hormone receptors and endocrine therapy of renal carcinoma].

One hundred sixty-five consecutive patients with resectable renal cancer entered a cooperative study to evaluate hormone treatment and steroid receptors. Twenty-nine patients with concomitant distant metastases (category M1) received intramuscular medroxyprogesterone acetate (MPA) 500 mg/day for at least two months after the operation. No measurable remission was observed, but 8 of 24 evaluable patients (33%) had disease stabilization for a median duration of 6 months. One hundred thirty-six cases with category M0 cancer were randomly allocated to a control group or to a treatment group with MPA 500 mg/3 times a week for one year. After a median follow-up period of over 3 years, 30 of 121 evaluable patients (24.8%) had a relapse, usually in distant sites. Relapses and survival were independent from postoperative treatment and sex. Only the extent of the disease and the presence of steroid receptors in the tumor were related with prognosis, but no relation could be found between receptors and response to hormone treatment. The presence of low concentrations of hormone receptors in a proportion of renal cancers remains unclear. However, MPA is confirmed to be only marginally active in metastatic renal cancer and the drug cannot be recommended as adjuvant to radically resected patients because of significant toxicity and lack of therapeutic activity.

Adolescent↗