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951.
Alpheus heterochaelis is able to recognise the dominance status of an opponent (see Part I of this series). A former loser does not fight against a former winner but rather escapes immediately after a contact. However, if a former loser meets an inexperienced opponent, the loser fights against it. Here we investigated the signal used for dominance recognition. Two groups of snapping shrimp that had lost a fight on Day 1, intact animals, and shrimp with cut lateral antennular filaments (i.e. without chemosensory aesthetascs), fought against the same winner on Day 2. Intact losers showed escape behaviour, while losers without aesthetascs showed almost the same aggressive behaviour as on Day 1. The main signal in dominance recognition is therefore a chemical one, possibly the urine or a substance carried by it. The main receptor organs for this signal are the lateral filaments of the antennules carrying the aesthetascs. 相似文献
952.
Maja Pijet Barbara Pijet Anna Litwiniuk Beata Pajak Barbara Gajkowska Arkadiusz Orzechowski 《Cytokine》2013,61(2):445-454
Reduced lean body mass in genetically obese (ob/ob) or anorectic/cachectic subjects prompted us to verify the hypothesis whether leptin, white adipose tissue cytokine, might be a negative organizer of myogenesis. Recombinant leptin (100 ng/mL) stimulated mitogenesis together with the raise in T202/Y204P-ERK1/2 protein expression. Concomitantly, it impaired cell viability and muscle fiber formation from C2C12 mouse myoblasts. Detailed acute and chronic studies with the use of metabolic inhibitors revealed that both JAK/STAT3 and MEK/MAPK but not PI3-K/AKT/GSK-3β signaling pathways were activated by leptin, and that STAT3 (Y705P-STAT3) and MEK (T202/Y204P-ERK1/2) mediate these effects. In contrary, insulin evoked PI3-K-dependent phosphorylation of AKT (S473) and GSK-3β (S9) and insulin surpassed leptin-dependent inhibition of myogenic differentiation in PI3-K-dependent manner. GSK-3β seems to play dual role in muscle development. Insulin-dependent effect on GSK-3β (S9P-GSK-3β) led to accelerated myotube construction. In contrary, leptin through MEK-dependent manner caused GSK-3β phosphorylation (Y216P-GSK-3β) with resultant drop in myoblast fusion. Summing up, partially opposite effects of insulin and leptin on skeletal muscle growth emphasize the importance of interplay between these cytokines. They determine how muscle mass is gained or lost. 相似文献
953.
For all living organisms, genome stability is important, but is also under constant threat because various environmental and endogenous damaging agents can modify the structural properties of DNA bases. As a defense, organisms have developed different DNA repair pathways. Base excision repair (BER) is the predominant pathway for coping with a broad range of small lesions resulting from oxidation, alkylation, and deamination, which modify individual bases without large effect on the double helix structure. As, in mammalian cells, this damage is estimated to account daily for 104 events per cell, the need for BER pathways is unquestionable. The damage-specific removal is carried out by a considerable group of enzymes, designated as DNA glycosylases. Each DNA glycosylase has its unique specificity and many of them are ubiquitous in microorganisms, mammals, and plants. Here, we review the importance of the BER pathway and we focus on the different roles of DNA glycosylases in various organisms. 相似文献
954.
Sergio Neri Santo Signorelli Davide Pulvirenti Barbara Mauceri Danila Cilio Fabio Bordonaro 《Free radical research》2013,47(6):615-618
To assess whether pathogenic endothelial dysfunction is involved in acute idiopathic tinnitus we enrolled 44 patients and 25 healthy volunteers. In blood from the internal jugular vein and brachial vein we determined malonaldehyde, 4-hydroxynonenal, mieloperoxidase, glutathione peroxidase, nitric oxide, l-arginine and l-ornitine, thrombomodulin (TM) and von Willebrand factor (vWF) activity during tinnitus and asymptomatic period.Higher plasma concentrations of oxidative markers and l-arginine, and lower nitric oxide and l-ornitine levels were observed in jugular blood of patients with tinnitus, there being a significant difference between brachial and jugular veins. TM and vWF activity were significantly higher in patients' jugular blood than in brachial blood.Our results suggest oxidant, TM, vWF activity production are increased and nitric oxide production reduced in brain circulation reflux blood of patients with acute tinnitus. These conditions are able to cause a general cerebro-vascular endothelial dysfunction, which in turn induce a dysfunction of microcirculation in the inner ear. 相似文献
955.
Barbara Piotrkowski Osvaldo R. Koch Elena M. V. De Cavanagh César G. Fraga 《Free radical research》2013,47(4):390-399
Renal and cardiac benefits of renin-angiotensin system inhibition exceed blood pressure (BP) reduction and seem to involve mitochondrial function. It has been shown that RAS inhibition prevented mitochondrial dysfunction in spontaneously hypertensive rats (SHR) kidneys. Here, it is investigated whether a non-antihypertensive enalapril dose protects cardiac tissue and mitochondria function. Three-month-old SHR received water containing enalapril (10 mg/kg/day, SHR+Enal) or no additions (SHR-C) for 5 months. Wistar-Kyoto rats (WKY) were normotensive controls. At month 5, BP was similar in SHR+Enal and SHR-C. In SHR+Enal and WKY, heart weight and myocardial fibrosis were lower than in SHR-C. Matrix metalloprotease-2 activity was lower in SHR+Enal with respect to SHR-C and WKY. In SHR+Enal and WKY, NADH/cytochrome c oxidoreductase activity, eNOS protein and activity and mtNOS activity were higher and Mn-SOD activity was lower than in SHR-C. In summary, enalapril at a non-antihypertensive dose prevented cardiac hypertrophy and modifies parameters of cardiac mitochondrial dysfunction in SHR. 相似文献
956.
Angela Maria Amorini Giuseppe Lazzarino Fabio Galvano Giovanna Fazzina Barbara Tavazzi Giacomo Galvano 《Free radical research》2013,47(4):453-460
The cyanidin-3- O - g -glucopyranoside (C-3-G) antioxidant capacity towards reactive oxygen species (ROS)-mediated damages was assessed in tissue and cells submitted to increased oxidative stress. In the isolated ischemic and reperfused rat heart, 10 or 30 w M C-3-G protected from both lipid peroxidation (66.7 and 94% inhibition of malondialdehyde (MDA) generation in 10 and 30 w M C-3-G-reperfused hearts, respectively, in comparison with control reperfused hearts) and energy metabolism impairment (higher ATP concentration in 10 and 30 w M C-3-G-reperfused hearts than in control reperfused hearts). These effects were associated to C-3-G permeation within myocardial cells, as indicated by results obtained in the isolated rat heart perfused for 30 min in the recirculating Langendorff mode under normoxia with 10 and 30 w M C-3-G. Protective effects were exerted, in a dose-dependent manner, by C-3-G also in 2 mM hydrogen peroxide-treated human erythrocytes. With respect to MDA formation, an apparent IC 50 of 5.12 w M was calculated for C-3-G (the polyphenol resveratrol used for comparison showed an apparent IC 50 of 38.43 w M). The general indications are that C-3-G (largely diffused in dietary plants and fruits, such as pigmented oranges very common in the Mediterranean diet) represents a powerful natural antioxidant with beneficial effects in case of increased oxidative stress, and at pharmacological concentrations it is able to decrease tissue damages occurring in myocardial ischemia and reperfusion. 相似文献
957.
Jose P. Vaqué Robert T. Dorsam Xiaodong Feng Ramiro Iglesias-Bartolome David J. Forsthoefel Qianming Chen Anne Debant Mark A. Seeger Bruce R. Ksander Hidemi Teramoto J. Silvio Gutkind 《Molecular cell》2013,49(1):94-108
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958.
Yu-jiang Yuan Tong-wen Zhang Wen-shou Wei Daniel Nievergelt Anne Verstege Shu-long Yu Rui-bo Zhang Jan Esper 《Dendrochronologia》2013,31(3):192-197
Three tree-ring maximum latewood density chronologies were developed from high elevation Picea schrenkiana sites in the western Tien Shan Mountains using different detrending methods. The new chronologies extend back to the early 16th and late 17th centuries, and contain significant late spring and summer temperature signals, respectively. An assessment of varying detrending methods and band-pass filtering the chronologies revealed only slightly differing low frequency trends retained in the maximum latewood densities. The distance between sampling sites and the varying seasonality of limiting climatic factors are identified as key drivers affecting the correlation among the maximum latewood density records in the study region. The new chronologies represent reliable proxies of high elevation late spring and summer temperature variability in an area underrepresented by such data, and are ready-to-use for network analyses addressing longer-term climate variations in eastern central Asia. 相似文献
959.
AbstractAccording to advances in phytogeographic knowledge, a revision of boundaries for the Italian Ecoregions have been made. Main changes relate to the southern and eastern limits between Temperate and Mediterranean Divisions. The revision triggered a comprehensive update of Ecoregions for an improved support to biodiversity and sustainable management initiatives. 相似文献
960.