Giovanni Delrio

Reproduction in the Mexican leaf frog, Pachymedusa dacnicolor: III. The female

The female of the Mexican leaf frog, Pachymedusa dacnicolor, displays a marked annual ovarian cycle. This consists of a long period of vitellogenic stasis, starting in early fall, soon after the breeding season, and ending in early spring. Oogonial proliferation continues throughout the year and new previtellogenic follicles are formed continuously. During the period of vitellogenesis, from spring to early summer, early, advanced, and postvitellogenic follicles are all found together, a situation that continues through the breeding season. This is correlated with the fact that a breeding female can lay three or more clutches per season. Breeding can begin as early as June and end as late as early September, with peak spawning activity taking place during July and August. An examination of the ovarian hormone secretion pattern in P. dacnicolor during the year revealed that plasma levels of testosterone and estradiol correlated with ovarian growth and attained highest levels in amplectant and ovulating females. Both hormones showed quite similar plasma levels and patterns of change during the annual reproductive cycle. Lowest plasma levels of testosterone and estradiol were found during fall and winter, in females possessing exclusively previtellogenic ovarian follicles. Plasma progesterone levels were maintained at a very low level throughout the year, except for the ovulatory surge, when amplectant and ovulating females may show a three- to sixfold increase. Plasma androstenedione showed a low peak during this phase of the reproductive cycle. Plasma levels of 5 alpha-dihydrotestosterone were 13 to 30 times lower than plasma testosterone levels. The potential roles of these gonadal steroids in controlling ovarian activity and reproduction are discussed briefly.

ADJUVANT THERAPY WITH TAMOXIFEN IN OPERABLE BREAST CANCER: 10 year results of the Naples (GUN) study

Treatment with tamoxifen (TM), alone or in combination with cyclophosphamide, methotrexate, and fluorouracil (CMF), was used as an adjuvant to surgery in 433 patients with stage I, II, or III(T3a) breast cancer. Oestrogen receptors (ER) and progesterone (PgR) receptors were assayed in most cases. 308 premenopausal node-negative and postmenopausal node-negative or node-positive patients were randomised to receive TM, 30 mg daily for 2 years, or no further therapy. 125 premenopausal node-positive patients were randomised to receive either CMF for nine courses plus TM or CMF alone. After a median follow-up of 63 months TM significantly reduced the incidence of relapses and deaths compared with no therapy. A significant interaction between treatment effect and ER/PgR status was seen. Disease-free and overall survival were similar after treatment with CMF+ TM or CMF.

Prolactin receptor does not correlate with oestrogen and progesterone receptors in primary breast cancer and lacks prognostic significance. Ten year results of the Naples adjuvant (GUN) study

The correlation between prolactin (PRLR) and oestrogen (ER) or progesterone receptors (PgR) in breast cancer and a possible prognostic significance of PRLR at 10 year follow-up have been investigated in the Naples (GUN) adjuvant trial. A total of 308 pre- and post-menopausal patients with early breast cancer, who entered the trial from 1 February 1978 to 31 December 1983, received randomly Tamoxifen (TM), 30 mg per die for 2 years, or no therapy. PRLR status was known in 229 (74.3%) patients. Values of specific binding less than 1% were considered negative. PRLR was positive in 75/229 (32.8%). ER was assayed in 210/229 (91.7%) patients and PgR in 188/229 (82.1%). No significant correlation, by the Spearman test, was found between PRLR and ER or PgR, while ER status was highly interrelated with PgR status. By the Cox model no evidence of an independent prognostic role of PRLR on disease-free survival (DFS) was observed, nor an interaction between PRLR and adjuvant treatment with TM was found.

Receptors for sex hormones in the skin of the amphibia

Abstract The retention of [ 3 H]-testosterone and the occurrence of specific receptors for sex hormones in the skin of males of Rana esculenta and Triturus cristatus were studied. In R. esculenta a selective uptake of testosterone and a receptor for androgens were observed, whereas in T. cristatus only a receptor for estrogens was found. These findings suggest that the body skin may be a secondary sex character in R. esculenta .

Morphological and biochemical variations in the skin of Rana esculenta during the annual cycle

Abstract The skin of both the male and female green frog ( Rana esculenta ) is an androgen-dependent secondary sex character. In this tissue an androgen receptor was identified biochemically; its presence was closely related to seasonal changes in the plasma levels of testosterone and in the epithelial height, glandular cell height, and total protein concentration of the skin.

The possible significance of testosterone in the female green frog Rana esculenta

Abstract The high level of testosterone in the plasma of the female Rana esculenta has raised a number of questions about the possible role of this hormone in reproductive physiology. To provide an explanation of this problem, in vivo and in vitro metabolism studies were carried out and the effect of testosterone on central and peripheral target organs was studied. Testosterone (T), 5α-dihydrotestosterone (DHT), estrone (E1), 17β-estradiol (E2) and 17α-OH-pregnenolone were found in ovarian tissue. The in vitro experiments showed that the ovary could metabolize testosterone into 5α-dihydrotestosterone, 11-ketotestosterone (11K-T) and 17β-estradiol, while the oviduct transformed it into 5α-dihydrotestosterone and 11-ketotestosterone. Testosterone administration to intact females provoked a slight increase in the plasma estrogen levels and to castrates it effected a partial restoration of the pituitary gonadotropic cells. On the oviduct only 5α-dihydrotestosterone seemed to have some effect but slight. The d...

Prolactin receptors in the male Rana esculenta

The binding of 125I-labeled ovine prolactin (oPRL) to membrane preparations of several tissues from the male green frog, Rana esculenta, collected during the year is reported. PRL binding to kidney fractions was generally high (range 5-45%). A maximum was observed in the month of October, whereas the lowest value was found during the summer season. The binding to skin fractions was equally high (range 5-25%) and the annual profile parallels that of renal fractions. In the liver, a lower specific binding (range 3-4%) occurred consistently during the year, whereas no detectable binding was found in the muscle. The 125I-oPRL binding was inhibited by oPRL and oGH but not by oFSH or oLH. Scatchard analysis gave dissociation constants of 0.4-1 x 10(-10) M and binding capacity of about 20 fmol/mg of membrane proteins was observed in both the skin and kidney fractions. No receptor sites were detectable in 30-day hypophysectomized animals. The administration of oPRL or a crude homogenate of the frog hypophysis induced the appearance of specific PRL binding. Testosterone is able to restore prolactin binding in hypophysectomized animals, as PRL treatment does.

Steroid hormone receptor levels and adjuvant tamoxifen in early breast cancer - Ten year results of the Naples (GUN) study

SummaryTen year disease-free survival (DFS) results of the Naples randomized trial of adjuvant tamoxifen (TM), 30 mg per day for 2 years versus no therapy according to receptor levels, are reported. From Feb. 1, 1978, through Dec. 31, 1983, 308 pre- and postmenopausal patients with early breast cancer entered the trial. Estrogen receptor (ER) data were available on 239 (77.6%) patients, progesterone receptor (PgR) data on 194 (63.0%), and both receptor data on 181 (58.8%).ER and PgR were assayed by dextran-coated charcoal technique in a single laboratory. The effect of adjuvant TM was significantly related to ER and PgR concentration of the primary tumor. The greatest TM benefit on DFS was evident in patients with the highest levels of receptors. The interaction between the treatment effect and receptor concentration was found whether ER and PgR were considered separately or together.

The effects of thyroidectomy on androgen and prolactin receptors in the dorsal skin and caudal fin of Triturus Cristatus carnifex

The interactions between thyroid hormones and receptors for steroid hormones and prolactin in dorsal skin and caudal fin of Triturus cristatus carnifex were studied during the annual cycle. Thyroidectomy induces an increase of prolactin binding in the dorsal skin and caudal fin in the animals captured in March. In these thyrodectomized animals the androgen receptors became undetectable. Results indicate that in Triturus cristatus carnifex the thyroid induces an increase of androgen receptors and a decrease, that is removed by thyroidectomy, of prolactin receptors.

Failure to Demonstrate Plasma Hormone Abnormalities in Women with Operable Breast Cancer

The endocrine profile of patients with breast cancer has been the object of extensive studies during the past several years. Abnormal secretion of a variety of hormones has been described on different occasions in patients with breast cancer (Gambrell, 1982; Henderson et al., 1982; Kirschner et al., 1982; Kwa and Wang, 1977; Ohgo et al., 1976), and has been considered a possible risk factor. However, conclusive evidence has not yet been presented to show that the cancer patients are significantly different in endogenous hormone profiles from their healthy counterparts. The main purpose of the present study was to critically reevaluate this controversial issue and possibly identify hormonal changes in a large population of patients with operable breast cancer not present in a comparable population of normal healthy women.