107 research outputs found

    Gestagens and glucocorticoids in chicken eggs

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    Avian eggs contain a variety of steroid hormones, which have been attributed as a tool for maternal phenotypic engineering. The majority of studies focuses on androgens, but also significant amounts of progesterone as well as other steroid hormones have been measured. The question if corticosterone is also present in eggs of chickens is currently under debate. The only analytical validation performed so far has failed to demonstrate corticosterone in the yolk of chickens, suggesting that antibodies for corticosterone measurement cross-react with other steroids present in the yolk. In order to investigate this assumption and to characterise potential cross-reacting hormones in more detail, we performed high-performance liquid chromatographic (HPLC) analyses of chicken yolk extracts and determined the concentration of immunoreactive corticosterone, progesterone and cortisol. The progesterone antibody revealed several immunoreactive substances, including progesterone, pregnenolone and two substances with lower polarity. The corticosterone enzyme immunoassay detected immunoreactive substances at exactly the same elution positions as the progesterone assay and a very small peak at the elution position of corticosterone. Immunoreactive cortisol was not found. In addition, inner and outer regions of the yolk sphere were analysed separately via HPLC. We found different concentrations of immunoreactive substances between the inner and outer yolk regions, probably reflecting the steroidogenic activity of the follicle cells during oocyte growth. We conclude that in homogenised yolk extracts without previous clean-up, the measured corticosterone concentrations may actually reflect those of progesterone and its precursors, most probably being 5 alpha- and 5 beta-pregnanes and pregnenolone. (C) 2009 Elsevier Inc. All rights reserved

    Sex differences in antipsychotic efficacy and side effects in schizophrenia spectrum disorder:results from the BeSt InTro study

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    Current guidelines for patients with schizophrenia spectrum disease do not take sex differences into account, which may result in inappropriate sex-specific treatment. In the BeSt InTro study, a total of 144 patients (93 men and 51 women) with a schizophrenia spectrum diagnosis and ongoing psychosis were included and randomized to amisulpride, aripiprazole, or olanzapine in flexible dose. This trial is registered with ClinicalTrials.gov (NCT01446328). Primary outcomes were sex differences in dose, dose-corrected serum levels, efficacy, and tolerability. Dosing was higher for men than for women in the aripiprazole group (p = 0.025) and, at trend level, in the olanzapine group (p = 0.056). Dose-corrected serum levels were 71.9% higher in women than in men for amisulpride (p = 0.019) and 55.8% higher in women than in men for aripiprazole (p = 0.049). In the amisulpride group, men had a faster decrease in psychotic symptoms than women (p = 0.003). Moreover, amisulpride was more effective than the other medications in men but not in women. Prolactin levels were higher in women than in men, especially for amisulpride (p < 0.001). Also, women had higher BMI increase on amisulpride compared to the two other antipsychotics (p < 0.001). We conclude that clinicians should be aware of the risks of overdosing in women, especially for amisulpride and aripiprazole. Amisulpride is highly effective in men, but in women, amisulpride showed more severe side effects and may thus not be the drug of first choice. Our study shows that sex differences should be taken into account in future studies on antipsychotics. Future research is warranted to evaluate these preliminary results

    First observations with CONDOR, a 1.5 THz heterodyne receiver

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    The THz atmospheric windows centered at roughly 1.3 and 1.5~THz, contain numerous spectral lines of astronomical importance, including three high-J CO lines, the N+ line at 205 microns, and the ground transition of para-H2D+. The CO lines are tracers of hot (several 100K), dense gas; N+ is a cooling line of diffuse, ionized gas; the H2D+ line is a non-depleting tracer of cold (~20K), dense gas. As the THz lines benefit the study of diverse phenomena (from high-mass star-forming regions to the WIM to cold prestellar cores), we have built the CO N+ Deuterium Observations Receiver (CONDOR) to further explore the THz windows by ground-based observations. CONDOR was designed to be used at the Atacama Pathfinder EXperiment (APEX) and Stratospheric Observatory For Infrared Astronomy (SOFIA). CONDOR was installed at the APEX telescope and test observations were made to characterize the instrument. The combination of CONDOR on APEX successfully detected THz radiation from astronomical sources. CONDOR operated with typical Trec=1600K and spectral Allan variance times of 30s. CONDOR's first light observations of CO 13-12 emission from the hot core Orion FIR4 (= OMC1 South) revealed a narrow line with T(MB) = 210K and delta(V)=5.4km/s. A search for N+ emission from the ionization front of the Orion Bar resulted in a non-detection. The successful deployment of CONDOR at APEX demonstrates the potential for making observations at THz frequencies from ground-based facilities.Comment: 4 pages + list of objects, 3 figures, to be published in A&A special APEX issu

    Elevated Plasma Corticosterone Decreases Yolk Testosterone and Progesterone in Chickens: Linking Maternal Stress and Hormone-Mediated Maternal Effects

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    Despite considerable research on hormone-mediated maternal effects in birds, the underlying physiology remains poorly understood. This study investigated a potential regulation mechanism for differential accumulation of gonadal hormones in bird eggs. Across vertebrates, glucocorticoids can suppress reproduction by downregulating gonadal hormones. Using the chicken as a model species, we therefore tested whether elevated levels of plasma corticosterone in female birds influence the production of gonadal steroids by the ovarian follicles and thus the amount of reproductive hormones in the egg yolk. Adult laying hens of two different strains (ISA brown and white Leghorn) were implanted subcutaneously with corticosterone pellets that elevated plasma corticosterone concentrations over a period of nine days. Steroid hormones were subsequently quantified in plasma and yolk. Corticosterone-implanted hens of both strains had lower plasma progesterone and testosterone levels and their yolks contained less progesterone and testosterone. The treatment also reduced egg and yolk mass. Plasma estrogen concentrations decreased in white Leghorns only whereas in both strains yolk estrogens were unaffected. Our results demonstrate for the first time that maternal plasma corticosterone levels influence reproductive hormone concentrations in the yolk. Maternal corticosterone could therefore mediate environmentally induced changes in yolk gonadal hormone concentrations. In addition, stressful situations experienced by the bird mother might affect the offspring via reduced amounts of reproductive hormones present in the egg as well as available nutrients for the embryo

    Excretion of catecholamines in rats, mice and chicken

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    Stress assessment favours methods, which do not interfere with an animal’s endocrine status. To develop such non-invasive methods, detailed knowledge about the excretion of hormone metabolites in the faeces and urine is necessary. Our study was therefore designed to generate basic information about catecholamine excretion in rats, mice and chickens. After administration of 3H-epinephrine or 3H-norepinephrine to male and female rats, mice and chickens, all voided excreta were collected for 4 weeks, 3 weeks or for 10 days, respectively. Peak concentrations of radioactivity appeared in one of the first urinary samples of mice and rats and in the first droppings in chickens 0.2–7.2 h after injection. In rats, between 77.3 and 95.6% of the recovered catecholamine metabolites were found in the urine, while in mice, a mean of 76.3% were excreted in the urine. Peak concentrations in the faeces were found 7.4 h post injection in mice, and after about 16.4 h in rats (means). Our study provides valuable data about the route and the profile of catecholamine excretion in three frequently used species of laboratory animals. This represents the first step in the development of a reliable, non-invasive quantification of epinephrine and norepinephrine to monitor sympatho-adrenomedullary activity, although promising results for the development of a non-invasive method were found only for the chicken

    Plasma Hormones Facilitated the Hypermotility of the Colon in a Chronic Stress Rat Model

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    Objective: To study the relationship between brain-gut peptides, gastrointestinal hormones and altered motility in a rat model of repetitive water avoidance stress (WAS), which mimics the irritable bowel syndrome (IBS). Methods: Male Wistar rats were submitted daily to 1-h of water avoidance stress (WAS) or sham WAS (SWAS) for 10 consecutive days. Plasma hormones were determined using Enzyme Immunoassay Kits. Proximal colonic smooth muscle (PCSM) contractions were studied in an organ bath system. PCSM cells were isolated by enzymatic digestion and IKv and IBKca were recorded by the patch-clamp technique. Results: The number of fecal pellets during 1 h of acute restraint stress and the plasma hormones levels of substance P (SP), thyrotropin-releasing hormone (TRH), motilin (MTL), and cholecystokinin (CCK) in WAS rats were significantly increased compared with SWAS rats, whereas vasoactive intestinal peptide (VIP), calcitonin gene-related peptide (CGRP) and corticotropin releasing hormone (CRH) in WAS rats were not significantly changed and peptide YY (PYY) in WAS rats was significantly decreased. Likewise, the amplitudes of spontaneous contractions of PCSM in WAS rats were significantly increased comparing with SWAS rats. The plasma of WAS rats (100 ml) decreased the amplitude of spontaneous contractions of controls. The IKv and IBKCa of PCSMs were significantly decreased in WAS rats compared with SWAS rats and the plasma of WAS rats (100 ml) increased the amplitude of IKv and IBKCa in normal rats
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