Search results for "Sexual Maturation"
showing 10 items of 17 documents
Energy intake functions and energy budgets of ectotherms and endotherms derived from their ontogenetic growth in body mass and timing of sexual matur…
2017
Abstract Ectothermic and endothermic vertebrates differ not only in their source of body temperature (environment vs. metabolism), but also in growth patterns, in timing of sexual maturation within life, and energy intake functions. Here, we present a mathematical model applicable to ectothermic and endothermic vertebrates. It is designed to test whether differences in the timing of sexual maturation within an animal's life (age at which sexual maturity is reached vs. longevity) together with its ontogenetic gain in body mass (growth curve) can predict the energy intake throughout the animal's life (food intake curve) and can explain differences in energy partitioning (between growth, repro…
Subcutaneous gonadotropin therapy in male patients with hypogonadotropic hypogonadism
1991
Objective The response to subcutaneous (SC) gonadotropin replacement therapy, using human chorionic gonadotropin (hCG) and human menopausal gonadotropin (hMG) or hCG alone, was evaluated in male hypothalamic hypogonadism. Design Sixteen patients with hypothalamic hypogonadism were treated with gonadotropins for induction of puberty and normalization of spermatogenesis. The results were analyzed retrospectively. Setting The study was carried out in a clinical endocrinology department providing tertiary care and in private practices of endocrinology. Patients Eight patients with idiopathic hypogonadotropic hypogonadism and eight patients with Kallmann's syndrome in prepubertal or early pubert…
The amelioration of olfactory acuity upon sexual maturation might affect food preferences.
2009
Upon sexual maturation, olfactory acuity in women ameliorates and starts oscillating across the cycle. During ovulation, mean olfactory threshold is 30 times lower than during bleeding. Interestingly, menstruated women undergo maleodorant trimethylaminuria. We argued that olfactory amelioration during ovulation might concur to a mating strategy, whereas olfactory impairment during bleeding might protect women against self-refusal. Testosterone and its 17β-estradiol derivative might be responsible for the synchronization of these menstrual events. Furthermore, we posed the question whether olfactory detection amelioration upon sexual maturation might provoke a change in food preferences, for…
Effect of oestrogen/gestagen replacement therapy on liver enzymes in patients with Ullrich-Turner syndrome.
1995
The absence of breast development and the prevention of osteoporosis in Ullrich-Turner syndrome (UTS) require oestrogen/gestagen substitution therapy. In 8 out of 35 (23%) patients with UTS treated with conjugated equine oestrogens and cyclically with norethisterone acetate, the serum liver enzymes increased to conspicuous levels (AST 35; 20-73 U/l, ALT 92; 37-141 U/l, GGT 77; 25-227 U/l, [median; min-max]). These findings were compared with those in 41 tall girls who received a six-fold larger dose of conjugated equine oestrogens for the reduction of final height. None of these 41 girls showed abnormal serum liver enzyme levels. The conspicuous rise in serum liver enzyme levels occurred in…
Identifying poor cardiorespiratory fitness in overweight and obese children and adolescents by using heart rate variability analysis under resting co…
2020
Background: Childhood obesity, including overweight, continues increasing worldwide affecting health expectancy, quality of life and healthcare expenditure. These subjects have higher probability of suffering or developing cardio metabolic risk factors. Recent studies have revealed cardiorespiratory fitness (CRF) as a valuable clinical parameter to identify these subjects and have even suggested cut-off values. However, evaluating CRF in overweight and obese youth can be difficult to implement, unfriendly and expensive. Objective: Develop a screening tool to identify high-risk subjects in a representative population of those attending overweight/obesity assessment programmes without prior i…
Increased Parasite Abundance Associated with Reproductive Maturity of the Clam Anodonta piscinalis
1999
Several studies on vertebrates have demonstrated that reproductive activities may increase the parasite load, but this has not been shown in invertebrate hosts. We studied abundance of a potentially harmful gill parasite, the ergasilid copepod Paraergasilus rylovi, from the freshwater bivalve host Anodonta piscinalis in relation to reproductive maturity of the host in the field. Prevalence of this previously unstudied parasite varied from 90 to 100%, and the mean parasite abundance from 16.3 to 28.8 among 3 study populations. Abundance of P. rylovi increased with host size. In the maturating age groups (3-5 yr) the length-adjusted mean parasite abundance among mature, reproducing female cla…
Serum leptin and interleukin-6 levels in pediatric patients with HIV.
2003
Recent therapeutic approaches have improved the prognosis of children with HIV. Many new efforts could be involved in their quality of life and therefore could need additional diagnostic strategies. Leptin regulates pubertal development; furthermore a continuous immune stimulus, as in chronic infectious diseases, can enhance leptin's secretion by the action of cytokines such as interleukin (IL)-6. To clarify this role in patients infected with HIV, we assayed leptin and IL-6 and evaluated the influence of HIV severity on its secretion. IL-6 (380.5 +/- 257.6 pg/ml; range: 22-900 pg/ml) showed a significant correlation with leptinemia, HIV-1 RNA, and viremia related to the stage of HIV diseas…
GENETIC BASIS OF THE TRADE-OFF BETWEEN OFFSPRING NUMBER AND QUALITY IN THE BANK VOLE
2004
One of the main tenets of modern life-history theory is the negative relationship (trade-off) between the number and quality of offspring produced. Theory predicts a negative genetic correlation between these traits since both are closely related to fitness of individuals. However, the genetic basis of the trade-off has only been tested to a limited extent in natural populations. We examined whether size and quality of offspring are negatively related to litter size in the bank vole Clethrionomys glareolus. First, we found a significant negative phenotypic correlation between the number and size of offspring at birth in both laboratory and field populations of the bank vole. Second, a large…
Neuroligin-2 Expression in the Prefrontal Cortex is Involved in Attention Deficits Induced by Peripubertal Stress
2016
Emerging evidence indicates that attention deficits, which are frequently observed as core symptoms of neuropsychiatric disorders, may be elicited by early life stress. However, the mechanisms mediating these stress effects remain unknown. The prefrontal cortex (PFC) has been implicated in the regulation of attention, including dysfunctions in GABAergic transmission, and it is highly sensitive to stress. Here, we investigated the involvement of neuroligin-2 (NLGN-2), a synaptic cell adhesion molecule involved in the stabilization and maturation of GABAergic synapses, in the PFC in the link between stress and attention deficits. First, we established that exposure of rats to stress during th…
Water temperature influences growth and gonad differentiation in European sea bass (Dicentrarchus labrax, L. 1758)
2016
The effect of rearing temperature on gonad differentiation and growth was evaluated in sea bass (Dicentrarchus labrax). One control group (CG, n = 60) and two experimental groups (EG1, n = 30; EG2, n = 30) were selected. CG was reared at 15.0 °C during 10 days post-hatch (dph) and at 19.0 °C throughout the remaining larval and post-larval development. EG1 was exposed to 14.5 °C from 1 to 50 dph, followed by an increase to 20 °C until sampling (176 dph). EG2 was exposed to 14.5 °C from 1 to 37 dph, followed by an increase to 20 °C until sampling (226 dph); 30 fish from CG were randomly sampled at 176 dph (CG1, control for EG1) and 30 fish were sampled at 226 dph (CG2, control for EG2). Weigh…