Dimethyl-Benz(a)anthracene: A mammary carcinogen and a neuroendocrine disruptor.

Polycyclic Aromatic Hydrocarbons (PAHs) are potent carcinogens. Among these, dimethylbenz(a)anthracene (DMBA) is well known for its capacity to induce mammary carcinomas in female Sprague-Dawley (SD) rats. Ovariectomy suppresses the susceptibility of this model to DMBA, thus suggesting that the inducible action of the carcinogen depends on ovarian hormones.

Short term changes in melatonin and cortisol serum levels after a single administration of estrogen to menopausal women.

Objectives: It has been well-documented that serum melatonin levels are insensitive to estrous or menstrual ovarian steroid variations in the female rat or the human. However, a negative coupling has been already demonstrated between the nocturnal serum melatonin peak and serum E2 concentration during the late premenopausal period in the woman. The objection of the present study was designed to determine if diurnal serum melatonin values can be also lowered by a single administration of estrogen.

Substance P plasma concentration during the LH preovulatory surge of the menstrual cycle in the human.

Objectives: In order to determine the exact pattern of plasma Substance P (SP) concentration during the LH preovulatory surge and the functional correlates which could exist between plasma SP, LH, 17 beta-estradiol (E2) and Progesterone, we performed a detailed analysis of changes in plasma SP concentration, during the critical phases of the LH preovulatory surge in the Human.

Methods: The experimental study was performed in 21 women between the ages of 26 and 35 years. For each subject, blood samples were taken every 15 min, between 07:00 a.

ACTH-cortisol activity during the 17beta-estradiol and LH preovulatory surges of the menstrual cycle.

Objectives: A strong positive coupling has been already documented between the adrenocortical axis and the gonadal axis at the time of the initiation of the preovulatory LH surge of the menstrual cycle in the human. The LH preovulatory surge starts in the morning at the time of the acrophase (maximal plasma cortisol values) of the cortisol circadian rhythm. Also, it was shown that morning maximal plasma cortisol values were higher during the follicular phase than during the luteal phase.

Trisomy 21: from chromosomes to mental retardation.

The first descriptions of the trisomy 21 phenotype were by Jean-Etienne-Dominique Esquirol (1838), Edouard Séguin (1846) and later by John L. H. Down in 1862.