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34392. Vasopressin in thermoregulation - competitive demands: experimental evidence and theoretical considerations

Creator:
Horowitz, M., Epstein, Y., and Shapiro, Y.
Type:
article, model:article, and TEXT
Subject:
thermoregulation, osmoregulation, vasopressin, and fever
Language:
English
Description:
Previous studies have substantiated the antipyretic role played by extrahypothalamic limbic system (EXHY-LS) AVP during fever. Repeated attempts to elucidate other thermoregulatory functions of this hormone have failed. Circumstantial evidence, however, suggest central role for this hormone in thermoregulation under hypohydration. Hypohydration, hyperosmolarity and hypovolaemia induce upward shifts in temperature thresholds for activation of heat dissipating mechanisms. When hypovolaemia is superimposed on hyperosmolarity these shifts are additive. Analogously, these two stressors when combined, decrease the osmotic threshold for AVP release. In rats, the elevated temperature thresholds for evaporative cooling and peripheral vasodilation occurring with hypohydration are positively correlated with lower Hypothalamic/EXHY-LS AVP ratio. Reciprocal relations between limbic system and blood AVP contents suggest competitive interaction between central and peripheral demands. Hypothesis for the possible mode of action of central AVP in thermoregulation under hypohydration is discussed.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

34393. Vasorelaxation by pinacidil in isolated perfused lungs is enhanced in rats with hypoxic pulmonary hypertension but is dependent on the constrictor

Creator:
Wanstall, J. C.
Type:
article, model:article, and TEXT
Subject:
pinacidil, rat perfused lungs, pulmonary hypertension, hypoxic pulmonary vasoconstriction, and noradrenaline
Language:
English
Description:
The potassium channel opening drug, pinacidil, has been examined in isolated perfused lungs taken from rats with hypoxic pulmonary hypertension (housed in 10 % oxygen for 7 days) and control rats. Inhibition by pinacidil (1 to 30 //M) of noradrenaline (NA)-induced vasoconstriction (NA infusions; /^-adrenoceptors blocked) and of hypoxic pulmonary vasoconstriction (HPV; ventilation for 3.5 -4.5 min with 0-1 % oxygen) were compared. The vasoconstrictor responses in preparations from control and hypoxic rats, respectively, were (mm Hg) NA 6.6±0.68 (6); 8.2±1.45 (9); HPV 7.8±1.03 (12); 8.8±0.93 (13). These responses were reversibly inhibited by pinacidil. In lungs from control rats pinacidil was 10-fold less potent against NA than against HPV, but in lungs from hypoxic rats it was equipotent against NA and HPV. When tested against NA, but not HPV, pinacidil was significantly more potent in lungs from hypoxic rats than control rats. It is postulated that NA-induced vasoconstriction in lungs from hypoxic rats, and HPV in both groups of rats, involve calcium influx through voltage-operated calcium channels. Consequently, these responses are readily inhibited by drugs such as pinacidil which open potassium channels and hyperpolarise the cell membrane. In contrast in lungs from control rats, NA-induced constriction may involve mainly intracellular calcium release and thus be less readily inhibited by the hyperpolarising effect of pinacidil.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

34394. Vasorelaxing action of vasonatrin peptide is associated with activation of large-conductance Ca2+-activated potassium channels in vascular smooth muscle cells

Creator:
Yu, J., Zhu, M., Fu, Z., Zhu, X., Zhao, Y., and Chen, B.
Format:
print
Type:
article, články, model:article, and TEXT
Subject:
Fyziologie člověka a srovnávací fyziologie, natriuretické peptidy, natriuretic peptides, vasonatrin peptide, vascular smooth muscle cells, calcium-activated potassium channels, cyclic guanosine monophosphate, 14, and 612
Language:
English
Description:
The aim of this study was to test the hypothesis that vasorelaxing action of vasonatrin peptide (VNP) is due to activation of the large-conductance Ca2+-activated potassium channel (BKCa) via guanylyl cyclase (GC)-coupled natriuretic peptide receptors (NPRs) in vascular smooth muscle cells (VSMCs). Contraction experiments were performed using human radial artery, whereas BKCa current by patch clamp was recorded in cells from rat mesenteric artery. Contractility of rings cut from human radial artery was detected in vitro. As a result, VNP induced a dose-dependent vasorelaxation of human radial artery, which could be mimicked by 8-Br-cGMP, and suppressed by TEA, a blocker of BKCa, HS-142-1, a blocker of GC-coupled NPRs, or methylene blue (MB), a selective inhibitor of guanylyl cyclase. Sequentially, whole-cell K+ currents were recorded using patch clamp techniques. BKCa current of VSMCs isolated from rat mesentery artery was obtained by subtracting the whole cell currents after applications of 10-7 mol/l iberiotoxin (IBX) from before its applications. In accordance with the results of arterial tension detection, BKCa current was significantly magnified by VNP, which could also be mimicked by 8-Br-cGMP, whereas suppressed by HS-142-1, or MB. Taken together, VNP acts as a potent vasodilator, and NPRA/B-cGMP-BKCa is one possible signaling system involved in VNP induced relaxation., J. Yu ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
Rights:
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34395. Vavraia culicis (Weiser, 1947) Weiser, 1977 revisited: cytological characterisation of a Vavraia culicis-like microsporidium isolated from mosquitoes in Florida and the establishment of Vavraia culicis floridensis subsp. n.

Creator:
Vávra, Jiří and Becnel, James J.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
Microsporidia, mosquitoes, Vavraia, ultrastructure, and light microscopic cytology
Language:
English
Description:
A brief nomenclatural history of Vavraia culicis (Weiser, 1947), the type species for the genus Vavraia Weiser, 1977, is presented together with a detailed description of the cytological and ultrastructural characteristics of a Vavraia culicis-like microsporidian species isolated from Aedes albopictus (Scuse) in Florida. This ''Florida isolate'', is the only known isolate of a species of the genus Vavraia from mosquitoes propagated in laboratory culture. Although the Florida isolate has been used under the name Vavraia culicis in several molecular phylogeny and host-parasite studies, it has not been structurally characterized and its relationship to the type species Vavraia culicis has never been examined. Structural data strongly support placement of the Florida isolate within the genus Vavraia and indicate its close relationship to both the type species of the genus and to other Vavraia-like mosquito microsporidia to which the name V. culicis has been applied. However, the identity of the Florida isolate with V. culicis (Weiser, 1947) Weiser, 1977 cannot be presently confirmed. Morphometric examination of spores of several Vavraia-like microsporidia isolates from mosquitoes, including the type material of Vavraia culicis, indicates that Vavraia culicis-like microsporidia probably represent not a single species, but a group of closely related organisms. Subspecies status is proposed for the Florida isolate.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

34397. Vázaný a nevázaný vzor písma u žáků 3. ročníku základní školy

Creator:
Kučerová, Olga, Kubín, Daniel, and Kuchraská, Anna
Type:
article, model:article, and TEXT
Subject:
písmo, kurzíva, Comenia Script, hodnocení písma, handwritting, italics, and handwritting assessment
Language:
Czech
Description:
Příspěvek1 je věnován popisu a srovnání písemného projevu žáka třetí třídy, který píše v běžném modelu vázaného písma (latinka) a v modelu písma nevázaného (Comenia Script). Odlišuje obtíže v psaní, které jsou pro dané období typické od těch, které by mohly naznačovat závažnější problémy. Žáci, kteří byli zapojeni do výzkumného projektu (N = 180), byli vyučováni metodou psaní Comenia Script a běžnou vázanou latinkou. Na konci třetí třídy (v roce 2013) prošli diagnostickou prověrkou, prostřednictvím které byly sledovány písařské a pisatelské dovednosti v obou modelech psaní. K hodnocení písemných produktů byla upravena hodnotící škála Veverkové a Kucharské (2012), která zahrnovala popis jevů, vážících se na grafomotorické a gramatické aspekty psaní, včetně celkové chybovosti a práce s chybou. Každá sledovaná oblast zahrnovala sérií ukazatelů, jejichž prostřednictvím bylo možno vytvořit ucelenou představu o podobě písemného projevu v daném období. Každý ukazatel byl samostatně bonifikován na tříbodové škále. Díky tomu vznikl celistvý obraz podoby písma současného školáka ve dvou vyučovaných modelech písma ve 3. ročníku. Dosažené výsledky by mohly sloužit v psychologické poradenské praxi. and This study is focused on the comparison of handwriting of pupils in the third grade of elementary school. There were two groups of subjects, the first one used ordinary handwriting and the second used the Comenia Script font. The study describes typical problems related to the learning level of both groups and pinpoints these which could be symptoms of more serious problems. The research sample was a group of 180 pupils divided equally. There was a diagnostic testing at the end of third grade (2013) focused on currently achieved handwriting skills of both groups. The methods and the differences were logged. For evaluation purposes there was used a modified assessing scale of Veverková and Kucharská (2012). It consists of four categories: graphomotoric aspects of handwriting, orthographic aspects of handwriting, the error rate and the ability of correcting errors. Every category contains number of indicators through which we completed overall apprehension of the handwriting level for examined pupils. Every indicator was independently classified at 1–3 scale. Results of this study might be used in the clinical psychological consulting.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

34400. Včasnostredoveké sídlisko v Brne-Medlánkach

Creator:
Benech, Jakub
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
Early Middle Ages, rural settlement, Moravia, material culture, and metallurgy
Language:
Czech
Description:
The presented article examines the early medieval settlement in Brno- -Medlánky. The archaeological finds were evaluated to obtain settlement spatial development and to reveal the practical, social and natural dimension of the settlement after the synthesis of the evidence. The relevance of the site in relation to early medieval Brno was also considered. The large quantity of ceramics, which was essential for this research, was processed using the database of J. Macháček. This enabled me to date the settlement between the 6th/7th to the 9th/10th century and, based on quantification, to characterise the morphological and technological features of the complex. The archaeological material was also compared with the material from other similar sites. The results of this analysis were acquired from data in the graphs, figures and quantification tables. The other findings were processed using descriptive models. Scientific analyses have proven the presence of blacksmithing and iron metallurgy at the site. Agricultural activities and processing of leather and textile were also documented at the site. The typical cumulative structure was evaluated within the framework of spatial analyses, together with the form and spatial development of the settlement. Moreover, the article deals with the complete skeletons of two dogs and one horse, and the human skeleton found in a storage pit. The complete animal skeletons were probably deposited for hygienic reasons; the human skeleton possibly proves an execution.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

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