62 research outputs found
Breeding status and social environment differentially affect the expression of sex steroid receptor and aromatase mRNA in the brain of female Damaraland mole-rats
INTRODUCTION: The Damaraland mole-rat (Fukomys damarensis) is a eusocial, subterranean mammal, which
exhibits an extreme reproductive skew with a single female (queen) monopolizing reproduction in each colony.
Non-reproductive females in the presence of the queen are physiologically suppressed to the extent that they
are anovulatory. This blockade is thought to be caused by a disruption in the normal gonadotropin-releasing
hormone (GnRH) secretion from the hypothalamus. In order to understand the underlying physiological mechanisms
of reproductive suppression in subordinate females we studied the expression of steroid hormone receptors and the
androgen-converting enzyme aromatase in forebrain regions involved in the control of reproductive behaviour in
female breeders and non-breeders from intact colonies. Additionally, we included in our analysis females that
experienced the release from social suppression by being removed from the presence of the queen.
RESULTS: We found expression of androgen receptor, estrogen receptor α and aromatase in several forebrain
regions of female Damaraland mole-rats. Their distribution matches previous findings in other mammals. Quantification
of the hybridisation signal revealed that queens had increased expression of androgen receptors compared to
non-breeders and removed non-breeders in most brain regions examined, which include the medial preoptic
area (MPOA), the principal nucleus of the bed nucleus of the stria terminalis (BSTp), the ventromedial nucleus of
the hypothalamus (VMH), the arcuate nucleus (ARC) and the medial amygdala (MeA). Furthermore, breeders had
increased estrogen receptor α expression in the anteroventral periventricular nucleus (AVPV) and in the MeA,
while aromatase expression in the AVPV was significantly reduced compared to non-breeders. Absence of social
suppression was associated with increased androgen receptor expression in the ARC, increased estrogen receptor
α expression in the MeA and BSTp and reduced aromatase expression in the AVPV.
CONCLUSION: This study shows that social suppression and breeding differentially affect the neuroendocrine
phenotype of female Damaraland mole-rats. The differential expression pattern of estrogen receptor α and aromatase
in the AVPV between breeders and non-breeders supports the view that this region plays an important role in
mediating the physiological suppression in subordinate females.Fellowships from the University of Pretoria to
CV and HL as well as the DST-NRF for funding to NB.http://www.frontiersinzoology.com/am201
Разработка плана тактических действий по тушению пожаров в зданиях повышенной этажности (на примере жилого дома с административными помещениями, этажность 25)
Анализ пожаров в городе Новокузнецке показывает, что около 70% пожаров происходит в жилом секторе. При этом в жилье гибнет при пожарах около 80% людей по последним статистическим данным. Объектом исследования является жилой дом, расположенный в городе Новокузнецке, центральный район. Цель дипломного проекта – разработать тактические действия по тушению пожаров в зданиях повышенной этажности на примере вышеупомянутого объекта исследования. В процессе исследования был проведен аналитический обзор научных трудов и информационных статей по вопросам обеспечения пожарной безопасности в зданиях промышленной этажности, представлена характеристика исследуемого объекта и факторы, влияющие на развитие пожара в высотных зданиях.Analysis of fires in the city of Novokuznetsk shows that about 70% of fires occur in the residential sector. While the housing dies in fires, about 80% of people according to recent statistics. The object of study is a residential building located in the city of Novokuznetsk Central district. The aim of the project is to develop tactical actions on a touch-NIJ fires in high-rise buildings on the example of the above-mentioned object of study. In the process of the study was an analytical review of scientific papers and news articles on issues of fire safety in buildings, industrial heights, are the characteristic of the object studied and the factors affecting the development of fire in high-rise buildings
Preventing and Reducing Coercive Measures—An Evaluation of the Implementation of the Safewards Model in Two Locked Wards in Germany
IntroductionAggression and violence are highly complex problems in acute psychiatry that often lead to the coercive interventions. The Safewards Model is an evidence-informed conflict-reduction strategy to prevent and reduce such incidents. The aim of this study was to evaluate the implementation of this model with regard to coercive interventions in inpatient care.Materials and MethodsWe evaluated outcomes of the implementation of the Safewards Model in two locked psychiatric wards in Germany. Frequency and duration of coercive interventions applied during a period of 11 weeks before and 11 weeks after the implementation period were assessed through routine data. Fidelity to the Safewards Model was assessed by the Organization Fidelity Checklist.ResultsFidelity to the Safewards Model was high in both wards. The overall use of coercive measures differed significantly between wards [case-wise: χ2 (1, n = 250) = 35.34, p ≤ 0.001; patient-wise: χ2 (1, n = 103) = 21.45, p ≤ 0.001] and decreased post-implementation. In one ward, the number of patients exposed to coercive interventions in relation to the overall number of Patients decreased significantly [χ2 (1, 281) = 6.40, p = 0.01]. Furthermore, the mean duration of coercive interventions overall declined significantly [U(55,21) = −2.142, p = 0.032] with an effect size of Cohen’s d = −0.282 (95% CI: −0.787, 0.222) in that ward. Both aspects declined as well in the other ward, but not significantly.DiscussionResults indicate that the implementation of the Safewards interventions according to the model in acute psychiatric care can reduce coercive measures. They also show the role of enabling factors as well as of obstacles for the implementation process
Mycobacteria Attenuate Nociceptive Responses by Formyl Peptide Receptor Triggered Opioid Peptide Release from Neutrophils
In inflammation, pain is regulated by a balance of pro- and analgesic mediators. Analgesic mediators include opioid peptides which are secreted by neutrophils at the site of inflammation, leading to activation of opioid receptors on peripheral sensory neurons. In humans, local opioids and opioid peptides significantly downregulate postoperative as well as arthritic pain. In rats, inflammatory pain is induced by intraplantar injection of heat inactivated Mycobacterium butyricum, a component of complete Freund's adjuvant. We hypothesized that mycobacterially derived formyl peptide receptor (FPR) and/or toll like receptor (TLR) agonists could activate neutrophils, leading to opioid peptide release and inhibition of inflammatory pain. In complete Freund's adjuvant-induced inflammation, thermal and mechanical nociceptive thresholds of the paw were quantified (Hargreaves and Randall-Selitto methods, respectively). Withdrawal time to heat was decreased following systemic neutrophil depletion as well as local injection of opioid receptor antagonists or anti-opioid peptide (i.e. Met-enkephalin, β-endorphin) antibodies indicating an increase in pain. In vitro, opioid peptide release from human and rat neutrophils was measured by radioimmunoassay. Met-enkephalin release was triggered by Mycobacterium butyricum and formyl peptides but not by TLR-2 or TLR-4 agonists. Mycobacterium butyricum induced a rise in intracellular calcium as determined by FURA loading and calcium imaging. Opioid peptide release was blocked by intracellular calcium chelation as well as phosphoinositol-3-kinase inhibition. The FPR antagonists Boc-FLFLF and cyclosporine H reduced opioid peptide release in vitro and increased inflammatory pain in vivo while TLR 2/4 did not appear to be involved. In summary, mycobacteria activate FPR on neutrophils, resulting in tonic secretion of opioid peptides from neutrophils and in a decrease in inflammatory pain. Future therapeutic strategies may aim at selective FPR agonists to boost endogenous analgesia
Expression of Tas1 Taste Receptors in Mammalian Spermatozoa: Functional Role of Tas1r1 in Regulating Basal Ca2+ and cAMP Concentrations in Spermatozoa
Background: During their transit through the female genital tract, sperm have to recognize and discriminate numerous chemical compounds. However, our current knowledge of the molecular identity of appropriate chemosensory receptor proteins in sperm is still rudimentary. Considering that members of the Tas1r family of taste receptors are able to discriminate between a broad diversity of hydrophilic chemosensory substances, the expression of taste receptors in mammalian spermatozoa was examined.
Methodology/Principal Findings:
The present manuscript documents that Tas1r1 and Tas1r3, which form the functional receptor for monosodium glutamate (umami) in taste buds on the tongue, are expressed in murine and human spermatozoa, where their localization is restricted to distinct segments of the flagellum and the acrosomal cap of the sperm head. Employing a Tas1r1-deficient mCherry reporter mouse strain, we found that Tas1r1 gene deletion resulted in spermatogenic abnormalities. In addition, a significant increase in spontaneous acrosomal reaction was observed in Tas1r1 null mutant sperm whereas acrosomal secretion triggered by isolated zona pellucida or the Ca2+ ionophore A23187 was not different from wild-type spermatozoa. Remarkably, cytosolic Ca2+ levels in freshly isolated Tas1r1-deficient sperm were significantly higher compared to wild-type cells. Moreover, a significantly higher basal cAMP concentration was detected in freshly isolated Tas1r1-deficient epididymal spermatozoa, whereas upon inhibition of phosphodiesterase or sperm capacitation, the amount of cAMP was not different between both genotypes.
Conclusions/Significance:
Since Ca2+ and cAMP control fundamental processes during the sequential process of fertilization, we propose that the identified taste receptors and coupled signaling cascades keep sperm in a chronically quiescent state until they arrive in the vicinity of the egg - either by constitutive receptor activity and/or by tonic receptor activation by gradients of diverse chemical compounds in different compartments of the female reproductive tract
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