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PubMed1979

Possible aspects of normal unphysiological commercial conditions on the estrus and early pregnancy in pigs.

Gilts and sows kept under unphysiological commercial conditions may show delayed puberty, delayed estrus postweaning and delayed returns after insemination. It is postulated that in all three manifestations gonadotropic insufficiency is the causative factor, produced by inadequate exteroceptive stimulation, mainly of olfactory origin, or by a configuration of stimuli which is experienced as in-appropriate by the individual organism. Pituitary L.H. is necessary to induce teritary follicles to secrete estrogens, which play a prominent part in estrus expression and in turn evoke the pre-ovulatory L.H. peak flow. Pituitary L.H. also appears to be necessary for persistence of of the corpora lutea during early pregnancy and this L.H. release may also be inhibited under inadequate physiological conditions. Therefore anaphrodisia in big commercial piggeries can be a normal physiologic reaction of the animal and more or less an adaptation to these unfavourable circumstances. For the greater part delayed puberty and delayed estrus postweaning seem to be coupled with anestrus and can easily be overcome by gonadotropin treatment in this case. Resulting fertility can be normal, even under severe stressful conditions. The delayed returns after insemination are partly caused by embryonal mortality. This mortality is at least for a part caused by gonadotropin insufficiency which in future may be prevented by application of a proper treatment as well.

Animal Husbandry↗

PubMed1985

Sexual maturation of the hypothalamus: pathophysiological aspects and clinical implications.

Sexual maturation in humans begins early in fetal life and culminates in adulthood when the gonads have acquired a full capacity for reproduction. It is remarkable that during this long process, the pituitary gonadal function, hence its hypothalamic control presents an alternative of activation and inhibition periods, during which the interrelations of the 3 components of the hypothalamic-pituitary-gonadal axis change gradually and inversely. The ontogeny of the hypothalamic-pituitary system, the varying activity of the reproductive endocrine system throughout sexual maturation and the developmental changes in the interrelations of the hypothalamic-pituitary-gonadal axis are reviewed: the most striking feature of human sexual development is the long inhibition of hypothalamo-pituitary function during childhood. Much indirect evidence points to the determining role of the CNS in the maturation of hypothalamic function: the occurrence of rhythms of secretion, the amplitude of secretions and peripubertal specific sleep-related nycthemeral rhythm of secretion at the onset of puberty. Despite the reality of a negative feedback control, these changes do occur independently of gonadal secretions since they are observed (qualitatively if not strictly quantitatively) in agonadal children. It is likely that neurotransmitters (dopamine, serotonine) and opiates have an inhibitory effect on Gn-RH release. But we still don't know their evolution during sexual maturation. It does not appear that melatonine plays any determinant role in the onset of human puberty. The clinical implications of our present understanding of the physiological events occurring during sexual maturation are several. Considering the major problems related to abnormal sexual maturation we will discuss successively: (1) diagnosis of hypogonadotrophic hypogonadism in early infancy; (2) differential diagnosis between premature thelarche and true sexual precocity; (3) the usefulness of endocrine investigations in the evaluation of hypothalamic-pituitary function; and (4) the new developments in the treatment of precocious puberty, delayed puberty or hypogonadism.

Adolescent↗

PubMedDate not supplied

[Pelvic echographic data during normal and pathological development in girls].

From a population of 60 normal females divided in 4 groups of 15 according to age and puberty, standards of uterine length and ovarian volume as measured by ultrasonography were established. The length of the uterus increases moderately with age (mean: 26.4 mm under 2 years of age; 29.5 mm from 2 to 8 years; 36.5 mm from 8 to 12 years) and significantly with puberty (mean: 60 mm), as does the volume of the ovaries (mean: 0.98 cm3 from 8 to 12 years; 3.4 cm3 after puberty). These standards, confirming former data, allow a better understanding of ultrasonographic findings during pathologic growth in young females, such as precocious puberty, delayed puberty, hypopituitarism, or hyperandrogenism. Thus, this investigation may assume an important part in the diagnosis of disorders of puberty, as it is innocuous and may be repeated as often as necessary during the growth of young patients. As it is non invasive and inexpensive, it could be the first investigation in some of these indications.

Adolescent↗

PubMed2005

Sonographic imaging of the paediatric female pelvis.

Several conditions necessitate a pelvic ultrasound in their management. In this paper, we will first review the embryology of the female genital system and the normal morphology of the uterus and ovaries from birth to puberty. Thereafter, this paper aims to categorise pelvic pathologies based on their clinical presentations. We will consider successively ambiguous genitalia, precocious puberty, delayed puberty and amenorrhea, gynaecological masses and, finally, pelvic pain of gynaecological origin. Ultrasound is the key screening tool and often the only examination indicated. The appropriateness of other modalities, such as computed tomography and magnetic resonance imaging, will be discussed. The aim of this article is to help radiologists form a sensible imaging plan when presented with a diagnostic dilemma involving the pelvis in female children.

Adolescent↗

PubMed1997

Relevance of molecular medicine to clinical obstetrics and gynecology.

Understanding molecular biology can improve the clinical acumen of the practicing obstetrician/gynecologist. An area of basic research now becoming clinically relevant involves the G proteins and G protein-coupled receptors. Clinicians already manipulate G protein-coupled receptors in their daily practice. Examples include the administration of oxytocin (oxytocin receptors), beta-2 tocolytic agents (beta 2-adrenergic receptors), GnRH agonists (GnRH receptors), exogenous gonadotropins (FSH and LH receptors), and bromocriptine (dopamine receptor). Clinically important disorders presenting to the obstetrician/gynecologist include some forms of precocious puberty, delayed puberty, premature ovarian failure, and pituitary adenomas which are due to mutations of G proteins and G protein-coupled receptors. The importance of these proteins is demonstrated by the fact that G protein-related genes comprise about 1 percent of the human genome. Additionally, the knowledge that some G protein gene mutations are present in the germ line, and others are somatic cell in origin (and not heritable), aids in more accurate genetic counseling to patients.

Cell Communication↗

PubMed2006

Body composition and concentrations of leptin, neuropeptide Y, beta-endorphin, growth hormone, insulin-like growth factor-I and insulin at menarche in girls with constitutional delay of puberty.

AIM: Constitutional delay of puberty (CDP), a rare condition among girls, manifests as retarded sexual maturity past the 13th year of life. The clinical and endocrinological aspects of this interesting problem appear to have escaped attention in the literature. The purpose of the present study was to compare body composition and concentrations of leptin, neuropeptide Y (NPY), beta-endorphin, growth hormone (GH), insulin growth factor-I (IGF-I) and insulin at menarche in CDP girls and girls with normal pubertal development (NP). MATERIALS AND METHODS: We enrolled 11 girls with CDP and 40 girls with NP. All participants were studied at or within 3 months of menarche. Age, height and weight were recorded. Body composition was established with a body composition analyzer. Radioimmunoassays were performed to measure concentrations of NPY, beta-endorphin, leptin, GH, IGF-I and insulin. RESULTS: The mean age at menarche in the CDP and NP groups was 16.1 and 12.5 years, respectively (p = 0.0001). CDP girls at menarche were taller (1.64 vs. 1.57 m; p = 0.012). The difference between groups in body weight (57.5 vs. 50.4 kg; p = 0.1), body mass index (BMI), fat mass, fat percentage (BF%) and lean mass was not significant, and nor was the difference in leptin, GH and insulin levels. However, CDP girls demonstrated significantly higher NPY concentrations (199.4+/-105.1 vs. 56.9+/-26.3 pg/ml; p = 0.001). NPY correlated with BF% (r = 0.60) in this group. IGF-I concentrations were significantly lower in CDP girls (524.8+/-50.6 ng/ml) than in NP girls (744.5+/-56.1 ng/ml; p = 0.024). CONCLUSION: Girls with CDP differed from NP girls only in age at menarche and height; they did not differ significantly with respect to BMI and body composition parameters. Higher concentrations of NPY in CDP girls may be responsible for CDP and reduced levels of IGF-I. Correlation of NPY with BF% suggests an involvement of this neuropeptide in the process of fat accumulation associated with CDP.

Adipose Tissue↗

PubMed2005

Sex features at menarche in relation to gonadotropin, estradiol and sex hormone-binding globulin concentrations in girls with constitutional delay of puberty. Preliminary report.

OBJECTIVE: Constitutional delay of puberty (CDP) is the absence of secondary sexual features in otherwise healthy girls past the 13th year of life. The aim of the present work was to follow the development of estrogen-dependent sexual features, determine the concentrations of gonadotropins, estradiol and sex hormone-binding globulin (SHBG) in girls with CDP at menarche and compare the findings with normal controls. METHODS: We enrolled 11 girls with CDP and 40 controls. Primary, secondary and tertiary sexual features were studied at menarche +/- 3 months. The size of the ovaries and uterus was measured using transabdominal ultrasound. Maturation of breasts and pubic hair was staged according to Tanner. Concentrations of gonadotropins (follicle-stimulating hormone (FSH), luteinizing hormone) and estradiol were measured with immunoenzymatic methods. For measurement of SHBG, a radioimmunoassay was applied. RESULTS: Menarche in CDP girls usually appeared with Stage IV or V of breast development and Stage IV of pubic hair development according to Tanner. CDP girls demonstrated a significantly smaller volume of the uterine body at menarche compared with controls (p = 0.0004). Significantly lower levels of FSH (p = 0.0363) and estradiol (p = 0.0332), as well as a tendency towards lower levels of SHBG, were revealed in CDP girls at menarche. CONCLUSION: In CDP girls, menarche is accompanied by more mature tertiary sexual features, apparently resulting from longer exposure of estrogen-dependent tissues to the action of bioactive endogenous estrogens. The smaller volume of the uterine body in CDP girls at menarche may be attributed to decreased concentrations of FSH and estradiol, as well as to the possibility of decreased insulin-like growth factor-1 and increased neuropeptide Y levels.

Adolescent↗

PubMed2005

Bone mineral density and markers of bone turnover in boys with constitutional delay of growth and puberty.

It has been suggested that poor growth in childhood or puberty might be a correctable determinant of osteoporosis. To assess the effect of the growth and puberty delay on bone metabolism, we measured bone mineral density (BMD) and markers of bone turnover in 41 boys with constitutional delay of growth and puberty. Total body (TB) and lumbar spine (LS) BMD were measured by dual-energy x-ray absorptiometry. Serum osteocalcin, total alkaline phosphatase, and urinary deoxypyridinoline cross-links as markers of bone turnover were evaluated. BMD was decreased by at least 1 sd in TB in 23 boys (56%) and in LS in 27 boys (66%). After adjustment of BMD for bone age, TB was decreased in 11 boys (27%) and LS in 13 boys (32%). Bone age and chronological age significantly correlated with areal and volumetric BMD. The significant increments of height, weight, TB, and LS BMD between the consecutive pubertal stages were reported. Mean alkaline phosphatase, osteocalcin, and deoxypyridinoline were within reference ranges and showed no differences between pubertal stages. In conclusion, in boys with constitutional delay of growth and puberty, bone turnover is normal, and BMD increases in a manner similar to healthy children.

Adolescent↗

PubMed2001

Management of puberty in constitutional delay of growth and puberty.

Constitutional delay of growth and puberty (CDGP) is the most common presenting form of short stature, but no single test can infallibly discriminate CDGP and isolated hypogonadotrophic hypogonadism. Management of puberty in CDGP aims to optimise not only growth maintaining body proportions and improving peak bone mass without impairing growth potential--but also well-being; for example, the distress boys often suffer because of their lack of growth and pubertal progression can affect their school performance and social relationships. Typical sex steroid treatments to induce puberty in boys with CDGP include testosterone (T) enanthate, T undecanoate, mixed T esters, T transdermal patches, and oxandrolone p.o. Compared with other regimens, short-course low-dose depot T i.m. is an effective, practical, safe, well tolerated, and inexpensive regimen. Some unresolved problems in management include optimal timing and dose of sex steroid treatment, the role of GH in CDGP, and the management of CDGP in girls.

Adolescent↗

PubMed1997

A dose-response analysis of the reproductive effects of a single gestational dose of 2,3,7,8-tetrachlorodibenzo-p-dioxin in male Long Evans Hooded rat offspring.

Male rats exposed in utero to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) display reduced fertility as a consequence of the direct action of TCDD on the epididymides, as well as delayed puberty and altered reproductive organ weights. The current study provides dose-response data for the reproductive effects of TCDD, administered during pregnancy, with an emphasis on the effects of TCDD on testicular, epididymal, and ejaculated sperm numbers. Long Evans Hooded rats were dosed by gavage with 0, 0.05, 0.20, or 0.80 microg TCDD/kg on Day 15 of gestation. After birth, growth, viability, and developmental landmarks were monitored in both male and female offspring. Shortly after puberty (49 and 63 days of age) and at 15 months of age, male offspring were necropsied. Growth and viability of the pups were reduced only at 0.80 microg TCDD/kg, eye opening was accelerated (all dosage groups), and puberty was delayed (at 0.20 and 0.80 microg TCDD/kg). Treated progeny displayed transient reductions in ventral prostate and seminal vesicle weights, while epididymal sperm reserves and glans penis size were permanently reduced. Ejaculated sperm numbers were reduced (45% in the 0.8 and by 25% in the 0.05 and 0.2 microg TCDD/kg dosage groups) to a greater degree than were cauda or caput/corpus epididymal or testicular (unaffected) sperm numbers. In conclusion, administration of TCDD on Day 15 of pregnancy at 0.05 microg/kg altered eye opening and reduced ejaculated sperm counts, while higher dosage levels also delayed puberty and permanently reduced cauda epididymal sperm reserves.

Animals↗

PubMed1989