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Author(s): P. Horváth [sup.1] , Z. Lázár [sup.1] , G. Gálffy [sup.1] , R. Puskás [sup.1] , L. Kunos [sup.1] , Gy. Losonczy [sup.1] , M. Mészáros [sup.1] , Á. [...], Purpose Obstructive sleep apnea (OSA) is characterized by chronic intermittent hypoxia which induces inflammation in blood vessels leading to the development of cardiovascular comorbidities. Several studies implicated the role of P-selectin in vascular inflammation of OSA. P-selectin glycoprotein ligand 1 (PSGL-1) is the main activator for P-selectin and is involved in immune cell trafficking. However, PSGL-1 has not been analyzed in OSA. The aim of the study was to investigate plasma PSGL-1 and P-selectin levels to have a deeper understanding on their interaction in obstructive sleep apnea. Methods Fifty-one untreated patients with OSA and 42 non-OSA controls were recruited. Plasma PSGL-1 levels were determined in evening and morning samples, P-selectin levels were analyzed in morning samples using commercially available ELISA kits. Polysomnography was performed in all participants. OSA was defined by an apnea-hypopnea index [greater than or equal to] 5/h. Results PSGL-1 levels did not differ between controls and OSA patients either in the evening or in the morning. Although, there was no difference between controls (16.9/6.8-40.8 ng/ml) and patients with OSA (19.6/8.4-56.8, p = 0.24), patients with severe OSA had increased plasma P-selectin levels (25.6/8.4-56.8 ng/ml) compared to mild OSA patients (14.1/8.5-35.3 ng/ml, p = 0.006) and controls (p = 0.03). Conclusions P-selectin expression relates to disease severity suggesting a pathophysiological role in endothelial cell activation. PSGL-1 levels are unaltered in OSA, suggesting an alternative activation pathway for P-selectin in OSA.

Sigma-1 receptor (S1R) is detected in different cell types and can regulate intracellular signaling pathways. S1R plays a role in the pathomechanism of diseases and the regulation of neurotransmitters. Fluvoxamine can bind to S1R and reduce the serotonin uptake of neurons and platelets. We therefore hypothesized that platelets express S1R, which can modify platelet function. The expression of the SIGMAR1 gene in rat platelets was examined with a reverse transcription polymerase chain reaction and a quantitative polymerase chain reaction. The receptor was also visualized by immunostaining and confocal laser scanning microscopy. The effect of S1R agonist PRE-084 on the eicosanoid synthesis of isolated rat platelets and ADP- and AA-induced platelet aggregation was examined. S1R was detected in rat platelets both at gene and protein levels. Pretreatment with PRE-084 of resting platelets induced elevation of eicosanoid synthesis. The rate of elevation in thromboxane B2 and prostaglandin D2 synthesis was similar, but the production of prostaglandin E2 was higher. The concentration-response curve showed a sigmoidal form. The most effective concentration of the agonist was 2 µM. PRE-084 increased the quantity of cyclooxygenase-1 as detected by ELISA. PRE-084 also elevated the ADP- and AA-induced platelet aggregation. S1R of platelets might regulate physiological or pathological functions. [ABSTRACT FROM AUTHOR]

Excess vegetative growth and irregular fruit‐bearing are often undesirable in horticultural practice. However, the biological mechanisms underlying these traits in fruit trees are not fully understood. Here, we tested if growth vigour and susceptibility of apple and pear trees to alternate fruit‐bearing are associated with vascular anatomy.We examined anatomical traits related to water transport and nutrient storage in young woody shoots and roots of 15 different scion/rootstock cultivars of apple and pear trees. In addition, soil and leaf water potentials were measured across a drought period.We found a positive correlation between the mean vessel diameter of roots and the annual shoot length. Vigorously growing trees also maintained less negative midday leaf water potential during drought. Furthermore, we observed a close negative correlation between the proportions of total parenchyma in the shoots and the alternate bearing index.Based on anatomical proxies, our results suggest that xylem transport efficiency of rootstocks is linked to growth vigour of both apple and pear trees, while limited carbohydrate storage capacity of scions may be associated with increased susceptibility to alternate bearing. These findings can be useful for the breeding of new cultivars of commercially important fruit trees. [ABSTRACT FROM AUTHOR]

The archetypical and phaseless vacuum magnetic flux density of O(3) electrodynamics, the B(3) field, is derived from the irreducible representation of the Einstein group and is shown to be accompanied by a vacuum energy density which depends directly on the square of the scalar curvature R of curved spacetime. The B(3) field and the vacuum energy density are obtained respectively from the non-Abelian part of the field tensor F μν and the non-Abelian part of the metrical field equation. Both of these terms are given by Sachs [5]. [ABSTRACT FROM AUTHOR]