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Hormonal Conditions (hormonal + condition)
Selected AbstractsDeterminants of within- and among-clutch variation in levels of maternal hormones in Black-Headed Gull eggsFUNCTIONAL ECOLOGY, Issue 3 2002Groothuis T. G. Summary 1.,Females of egg-laying vertebrates may adjust the development of their offspring to prevailing environmental conditions by regulating the deposition of hormones into their eggs. Within- and amng-clutch variation in levels of steroid hormones were studied in the egg yolks of the Black-Headed Gull (Larus ridibundus, Linnaeus) in relation to environmental conditions at the nest site. This species breeds in colonies of different densities and in different habitats, and the chicks hatch asynchronously. 2.,Egg yolks contained very high levels of androstenedione, substantial levels of testosterone and moderate levels of 5,-dihydrotestosterone. Oestrogen (17,-oestradiol) was not detected. 3.,Androgen levels increased strongly with laying order, irrespective of egg or yolk mass. This may compensate for the disadvantages of the later hatching chicks. These results have implications for adaptive hypotheses that were proposed for asynchronous incubation. 4.,Eggs of lighter clutches contained more androgens, perhaps to compensate for a lower nutritional quality of these eggs. 5.,Birds breeding in the periphery of a colony, being relatively more aggressive and having relatively large territories, laid eggs that contained more androgens than those of birds breeding in the centre. These high yolk androgen levels may facilitate growth and motor development of the chicks, which may be especially important for chicks developing at the periphery of a colony. Reduced levels may be adaptive for birds breeding in the centre, where risk of infectious diseases is high, since steroids may be immunosuppressive. 6.,Corrected for nest distance, clutches of birds in high vegetation, where predation risk is less severe and therefore competition for nest sites perhaps high, contained relatively high levels of androgens. It is suggested that the level of yolk androgens reflects the hormonal condition of the female, that in turn is influenced by her characteristics such as her age and aggressiveness, and the level of social stimulation. [source] Paradoxical Hypertrichosis After Laser Therapy: A ReviewDERMATOLOGIC SURGERY, Issue 3 2010SHRADDHA DESAI MD BACKGROUND Laser hair removal is a safe and effective procedure for the treatment of unwanted body hair but is not exempt from side effects. A rare but significant adverse effect with this treatment modality is paradoxical hypertrichosis. OBJECTIVE To evaluate the potential etiologies, risk factors, related laser types, and treatment options for the development of excess hair after laser therapy. MATERIALS AND METHODS An analysis of previously published case studies and review articles along with our own experience was used to gather information regarding this phenomenon. RESULTS Paradoxical hypertrichosis has a low incidence, ranging from 0.6% to 10%, and most commonly occurs on the face and neck. All laser and light sources have the potential to cause hair induction, especially in individuals with darker skin types (III,VI); with dark, thick hair; and with underlying hormonal conditions. Possible causes include the effect of inflammatory mediators and subtherapeutic thermal injury causing induction of the hair cycle. Treatment for paradoxical hypertrichosis is laser therapy of the affected area. CONCLUSIONS Paradoxical hypertrichosis is a rare side effect of laser hair removal; the pathogenesis of this event remains widely unknown. We recommend further large-scale studies to investigate this effect. The authors have indicated no significant interest with commercial supporters. [source] Effect of estradiol on striatal dopamine activity of female hemiparkinsonian monkeysJOURNAL OF NEUROSCIENCE RESEARCH, Issue 7 2009Marc Morissette Abstract A higher prevalence and incidence of Parkinson's disease is observed in men, and beneficial motor effects of estrogens are observed in parkinsonian women. In rodents, an effect of estradiol on dopamine systems is documented, whereas much less is known in monkeys. Enkephalin was shown to exert a compensatory modulatory effect on the denervated dopamine nigrostriatal pathway in monkeys and in humans. Moreover in rodents, striatal preproenkephalin mRNA is increased by estrogen treatment. Hence, we investigated the responsiveness of striatal dopamine to estradiol in long-term ovariectomized monkeys bearing a unilateral lesion with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) to mimic parkinsonian postmenopausal women. Seven ovariectomized female monkeys received a unilateral MPTP lesion; 4 years after ovariectomy, three received 1-month treatment with 17,-estradiol and the others received vehicle. The lesioned striata showed extensive denervation in all monkeys as measured with dopamine and metabolite concentrations assayed by high-performance liquid chromatography and by autoradiography of the dopamine transporter. The lesioned and intact striata of estradiol-treated monkeys had increased 3-methoxytyramine, and lesioned putamen increased dopamine concentrations compared with vehicle-treated monkeys. Estradiol treatment increased the dopamine transporter in subregions of the intact caudate and putamen compared with the intact striata of vehicle-treated monkeys, but not in the lesioned striata. Preproenkephalin mRNA levels measured by in situ hybridization were increased in the lesioned striata of vehicle treated monkeys and were not further enhanced in estradiol-treated monkeys. These results show that long after ovariectomy, modeling postmenopausal hormonal conditions, brain dopamine metabolism, and transporter are still responsive to estradiol. © 2008 Wiley-Liss, Inc. [source] ACUTE PRESSURE,NATRIURESIS RELATIONSHIP FOLLOWING WITHDRAWAL OF CHRONIC NORADRENALINE INFUSIONCLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY, Issue 9 2007EI Boesen SUMMARY 1Pathological changes to the kidney, such as vascular remodelling, have been found in several models of hypertension and may contribute to the maintenance of hypertension or confer susceptibility to redeveloping hypertension after the original prohypertensive stimulus is withdrawn. 2To investigate whether noradrenaline-induced hypertension induces persistent, functionally important changes to the kidney, the acute pressure,natriuresis relationship was characterized in anaesthetized rats under controlled neural and hormonal conditions following chronic (14 days) intravenous infusion of noradrenaline (48 µg/kg per h) or vehicle (0.04 mg/mL ascorbic acid and 0.156 mg/mL NaH2PO4·2H2O in 10 IU/mL heparinized saline). 3Conscious mean arterial pressure was significantly elevated by infusion of noradrenaline at 48 µg/kg per h (+10 ± 2 mmHg at Day 14; P < 0.01 vs vehicle group). The acute relationships between arterial pressure and renal blood flow, glomerular filtration rate, Na+ excretion and urine flow were not significantly different between the noradrenaline- and vehicle-infused rats immediately after termination of noradrenaline infusion. 4In summary, chronic intravenous noradrenaline infusion did not cause persistent changes in renal function, indicating that, in contrast with many models of hypertension, this model does not induce underlying prohypertensive changes to the kidney. [source] | |||||||||||||