338 research outputs found
A Cova de sa Guitarreta barlangból származó denevérguanó δ13C-izotópos vizsgálata és paleoéghajlattani alkalmazása: The δ13C isotope study and paleoclimatic application on bat guano from Cova de sa Guitarreta cave
The main topic of this study, the δ13C isotopic data interpretation of bat guano, from Cova de sa Guitarreta cave, Mallorca, Spain. The aim of the research was the paleoclimatic reconstruction of the area. For the analytical part of this study, was used the Combustion Module Cavity Ring Down Spectrocopy of the Geochemistry Laboratory of UBB, Cluj-Napoca. The results correlate well with other measurments and show climate cooling between 870-1978 in the island.  
Central Regulation of Pituitary-Thyroid Axis Under Physiological and Pathophysiological Conditions.
TRH is a tripeptide amide that functions as a neurotransmitter but also serves as a neurohormone that has a critical role in the central regulation of the hypothalamic-pituitary-thyroid axis. Hypophysiotropic TRH neurons involved in this neuroendocrine process are located in the hypothalamic paraventricular nucleus and secrete TRH into the pericapillary space of the external zone of the median eminence for conveyance to anterior pituitary thyrotrophs. Under basal conditions, the activity of hypophysiotropic TRH neurons is regulated by the negative feedback effects of thyroid hormone to ensure stable, circulating, thyroid hormone concentrations, a mechanism that involves complex interactions between hypophysiotropic TRH neurons and the vascular system, cerebrospinal fluid, and specialized glial cells called tanycytes. Hypophysiotropic TRH neurons also integrate other humoral and neuronal inputs that can alter the setpoint for negative feedback regulation by thyroid hormone. This mechanism facilitates adaptation of the organism to changing environmental conditions, including the shortage of food and a cold environment. The thyroid axis is also affected by other adverse conditions such as infection, but the central mechanisms mediating suppression of hypophysiotropic TRH may be pathophysiological. In this review, we discuss current knowledge about the mechanisms that contribute to the regulation of hypophysiotropic TRH neurons under physiological and pathophysiological conditions
Bidirectional and unidirectional comitative constructions in Hungarian: A psycholinguistic investigation at the interface of argument structure and semantics
This paper explores how bidirectional and unidirectional comitative constructions are processed at the level of argument structure. Bidirectional comitative constructions describe events where the two actors undergo the same effect described by the predicate (e.g., John was kissing with Mary), whereas unidirectional comitative constructions describe events in which one of the actors is the agent, and the other one is the patient (e.g., John was messing with Mary). In particular, we used the self-paced reading paradigm to determine if the two constructions access distinct mental representations. The findings suggest that distinct mental representations are activated automatically by bidirectional and unidirectional verbs during online language comprehension
Az ""alacsony T3 szindróma"" kialakulásáért felelős központi idegrendszeri szabályozó mechanizmusok tanulmányozása patkányban = Central regulatory mechanisms involved in the development of the 'low T3 syndrome'
A pályázat fĹ‘ cĂ©lja az Ă©hezĂ©s Ă©s fertĹ‘zĂ©s hatására kialakulĂł centrális hipotiroidizmus kialakulásáért felelĹ‘s központi idegrendszeri szabályozĂł mechanizmusok tanulmányozása volt. Kimutattuk, hogy a leptin, inzulin Ă©s glĂĽkĂłz eltĂ©rĹ‘ hatást fejt ki az arcuatus idegmag sejtjeire Ă©s csak a leptin kĂ©pes kivĂ©deni az Ă©hezĂ©s hatására kialakulĂł centrális hipotiroidizmust. LeĂrtuk, hogy az AGRP TRH idegsejtekre kifejtett gátlĂł hatását elsĹ‘sorban a 4-es tĂpusĂş melanokortin receptor (MC4-R) közvetĂti. Igazoltuk, hogy a PVN MC4-R tartalmĂş idegsejtjein a legtöbb AGRP tartalmĂş terminális közelĂ©ben nem figyelhetĹ‘k meg ?-MSH-tartalmĂş vĂ©gzĹ‘dĂ©sek, valĂłszĂnűsĂtve, hogy az AGRP a PVN-ben inverz agonistakĂ©nt hathat. LeĂrtuk, hogy LPS kezelĂ©s a pajzsmirigyhormonok szintjĂ©nek változásátĂłl fĂĽggetlenĂĽl D2 aktivitás fokozĂłdást eredmĂ©nyez a mediobazális hipotalamuszban a tanycytákban. Továbbá azonosĂtottuk a D2 promoter NF-kB kötĹ‘helyĂ©t. Ezek alapján feltĂ©telezzĂĽk, hogy LPS hatására a megemelkedett D2 aktivitás az eredmĂ©nyezett lokális hipertiroidizmus rĂ©vĂ©n hozzájárul a TRH idegsejtek gátlásához. | The long term goal of the proposed studies was the examination of the hypothalamic regulatory systems involved in the development of the central hypothyroidism induced by fasting or infection. We have described that leptin, insulin and glucose have different effects on the neurons of the arcuate nucleus. In addition, only leptin is able to reverse the fasting induced changes of the hypothalamic-pituitary-thyroid axis. We have demonstrated that the effect of AGRP on the hypophysiotropic TRH neurons is primarily mediated by the melanocortin 4 receptor (MC4-R). In addition, we have provided evidence that ?-MSH-containing varicosities are not present in the proximity of the AGRP terminals on the surface of the MC4-R-producing cells in the PVN, suggesting that AGRP acts as an inverse agonist in the PVN. We have demonstrated that LPS induces an increase of D2 activity in the tanycytes of the mediobasal hypothalamus. These changes are independent from the changes of the peripheral thyroid hormone level. Furthermore, we have identified the NF-kB binding cite of the D2 promoter. Based on these data, we hypothesize that the LPS induced increase of D2 activity results in a local hyperthyroidism in the PVN that contribute to the LPS induced inhibition of the hypophysiotropic TRH neurons
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