Puberty humans

Den Hond E Schoeters G (2006) Endocrine disrupters and human puberty. Int J Androl, 29(1) 264-271. 

R, J. L, and Preece, M. A. Melatonin, the Pineal Gland and Human Puberty... 

Among the endocrine organs, the testes are unique because they are suspended in a tissue pouch outside of the body cavity. The testes can be felt and these organs are vulnerable to physical insults, either deliberate or accidental. The effects of castration were described by Aristotle over three hundred years B.C. Removal of the testes or castration as a form of punishment or tribute dates to antiquity. Domestic animals and some cases humans were castrated to make them more docile. Castrata were valued as harem keepers. In addition, seasonal changes in behavior and the dramatic anatomical and behavioral events associated with puberty were components of the natural world (Bronson and Heideman, 1994). Thus, an awareness of a relationship between the testes and human behavior predates written history. 

If 3,3 -dichlorobenzidine is aetivated to a mutagenie intermediate by CYP1A2, this would have relevanee to exposure in utero and in neonates. Human fetal liver does not contain appreciable amounts of CYP1A2 (Leeder and Kearns 1997). Adult levels of CYP1A2 are reached at about 4 months of age and may be exceeded in 1-2-year-old ehildren. CYP1A2 levels subsequently decline and reach adult levels at the end of puberty. 

Not present in appreciable levels in human fetal liver. Adult levels reached by approximately 4 months and exceeded in children at 1-2 years of age. Adult activity reached after puberty. Fetal form of CYP3A which is functionally active (and inducible) during gestation. Virtually disappears by 1-4 weeks of postnatal when CYP3A4 activity predominates, but remains present in approximately 5% of individuals. 

An examination by the dentist should eliminate many of the potential systemic issues that can affect the periodontium of this patient. For example, the age of the patient, her appearance, and questions about her diet should be enough to rule in or out issues concerning puberty and malnutrition. However, if systemic conditions cannot be ruled out, an additional physical examination by a physician may be necessary. Additional tests to be requested could include oral glucose tolerance test for diabetes mellitus, human chorionic gonadotropin levels for pregnancy, and/or qualitative and quantitative evaluation of bone marrow cells and blood cells for leukemia. 

Childhood abuse Adult humans Before puberty 24-hour urinary cortisol a... 

Patients with 11/1-hydroxylase deficiency present with features of androgen excess, including masculinization of female newborns and precocious puberty in male children. There are two human isozymes that are responsible for cortisol and aldosterone synthesis, respectively. The CYP11B1 enzyme (p45011B) converts DOC to corticosterone (B) and 11-deoxycortisol (S or 11-dihydrocortisol) to cortisol (F). It is also capable of 18-hydroxylating DOC but cannot convert to aldosterone. The latter transformation is carried out by CYP11B2 (also known as aldosterone synthase), which encompasses activity for 18-hydroxylation and subsequent 18-oxidation. When CAH is associated with hypertension, deficient lljS-hydroxylase (CYP11B1) is suspected at this time more than ten mutations have been defined in affected individuals [103]. 

In the humans, the primordial germ cells are differentiated from about the sixth week of gestation and are consequently susceptible from then onward. In the female, production of the primary oocytes, which involves the first meiotic division, occurs in fetal life. These primary oocytes do not mature into ova until puberty, with the second meiotic division yielding one ovum from each primary oocyte (Fig. 6.48). 

Androgen synthesis in the human male fetus begins at the age of about 70 days when the testes enlarge and go through an important period of activity that begins the conversion of the infant body to a male type. Other bursts of testosterone synthesis occur during infancy, but there is little further synthesis until the onset of puberty.268 272... 

The androgens stimulate the development of the male secondary structures, such as the penis, scrotum, seminal vesicles, prostate gland, vas deferens and epididymis. The deepening of the voice, the growth of pubic, axillary, body, and facial hair, as well as the development of the characteristic musculature of the human male, are also under the influence of testosterone. If the testes fail to develop or are removed prior to puberty, these changes do not occur. Thus, testosterone is essential for reproductive function of the male. 

Melatonin affects reproduction in seasonally breeding animals. In humans, findings of increased endogenous melatonin in hypogonadism and low concentrations in precocious puberty imply an interaction between melatonin and gonadotropins however, data on the effects of exogenous melatonin are limited (1). In a randomized study in 16 women, melatonin enhanced LH and FSH responses to submaximal GnRH stimuli in the follicular but not the luteal phase of the menstrual cycle (24). 

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