464 research outputs found
Possible Involvement of Endothelin Peptides and L-Arginine-Nitric Oxide Pathway on the Effect of Endotoxin in the Rabbit Isolated Perfused Kidney
Escherichia coli endotoxin (LPS) when infused through the renal
artery of the rabbit isolated perfused kidney prepared as constant
pressure mode, caused a decrease in flow rate and kidney weight
indicating its primary vasoconstrictor effect. This effect was
predominant in kidneys from rabbits pretreated with LPS. Endothelin-1
at a concentration of 10−10 M and big endothelin-1 at a concentration
of 10−8 M produced equal vasoconstrictor effects in kidney. Addition
of endotheHn converting enzyme inhibitor, phosphoramidon, to the
perfusion medium at a concentration of 10−6 M caused a reduction in
the effects of both LPS and big ET-1 without altering the
vasoconstrictor effect of ETol. However, addition of methylene blue
(10−5 M), a soluble guanylate cyclase inhibitor and
NG-nitro-L-arginine-methyl ester (10−6 M) to the perfusion medium
caused a potentiation in the vasoconstrictor effect of LPS.
Indomethacin at a concentration of 10−6 M did not alter the effect of
LPS. These results were taken as evidence for the participation of
endothelin peptides and the L-arginine-nitric oxide pathway in the
effect ofLPS in rabbit isolated perfused kidney
Higher P-Wave Dispersion in Migraine Patients with Higher Number of Attacks
Objective and Aim. An imbalance of the sympathetic system may explain many of the clinical manifestations of the migraine. We aimed to evaluate P-waves as a reveal of sympathetic system function in migraine patients and healthy controls. Materials and Methods. Thirty-five episodic type of migraine patients (complained of migraine during 5 years or more, BMI < 30 kg/m2) and 30 controls were included in our study. We measured P-wave durations (minimum, maximum, and dispersion) from 12-lead ECG recording during pain-free periods. ECGs were transferred to a personal computer via a scanner and then used for magnification of x400 by Adobe Photoshop software. Results. P-wave durations were found to be similar between migraine patients and controls. Although P WD (P-wave dispersion) was similar, the mean value was higher in migraine subjects. P WD was positively correlated with P max (P < 0.01). Attacks number per month and male gender were the factors related to the P WD (P < 0.01). Conclusions. Many previous studies suggested that increased sympathetic activity may cause an increase in P WD. We found that P WD of migraine patients was higher than controls, and P WD was related to attacks number per month and male gender. Further studies are needed to explain the chronic effects of migraine
Influence of Fathers on Children Development
The literature indicated two controversial perspectives about the father’s importance on adolescent development (Amato, 1994). First one suggested a minimal role of fathers in child development and lives, and second one suggested that father involvement contribute positively to children’s well-being and development. A growing body of research suggests that adolescents’ relationship with their fathers was related to healthier psychosocial outcomes
Support through Social Media and Online Class Participation to Enhance Psychological Resilience
Social support was an important factor in minimizing the effect of social isolation during the COVID-19 pandemic lockdown. This research aimed to study the role of online class participation and social media usage to link the social support available from family and friends to psychological resilience among pre-service special education teachers against the negative psychological effects of the COVID-19 pandemic lockdown. A survey was conducted with 377 pre-service special needs education (SNE) teachers enrolled at universities in Pakistan. Partial least square structural equation modeling (PLS-SEM) was applied using Smart-PLS 3.2.8. Results revealed that social media and online class participation played a mediating role between social support and psychological resilience in the pre-service special needs education (SNE) teachers studied. Teacher education institutions can devise strategies to develop social media platforms for student socialization during an emergency to help build resilience against the negative psychological effects of social isolation. Future studies could be conducted to adapt instructions and curricula to social media environments for education in an emergency.Peer reviewe
Protective effects of green tea on blood and liver of rats fed with high fructose diet
Abstract This study was designed to investigate the effects of green tea on lipid profile, liver tissue damage, and oxidative stress in rats fed a diet including high fructose. Sprague-Dawley rats were randomly divided into four groups: Control (C), Fructose (F), Green Tea (GT), and F+GT. F and F+GT groups were given 20 fructose in the drinking water for eight weeks. Green tea (2 mg kg−1) was administrated to GT and F+GT groups by oral gavage for eight weeks. Biochemical parameters in serum and oxidative stress markers in the liver were analysed. The liver sections were stained with haematoxylin-eosin. As of the 3rd week of the experiment, the body weight of rats in the F group showed a statistically significant increase in comparison with the F+GT group. The serum glucose and triglyceride levels of the F+GT group significantly decreased when compared with the F group. The fructose-induced degenerative changes in the liver were reduced with green tea. Green tea may serve a protective role against hyperlipidaemia and liver injury in rats fed a high fructose diet
Sulfur Poisoning and Regeneration Behavior of Perovskite-Based NO Oxidation Catalysts
SOxuptake and release properties of LaMnO3, Pd/LaMnO3, LaCoO3and Pd/LaCoO3perovskites were investigated via in situ Fourier transform infrared (FTIR) spectroscopy, temperature programmed desorption and X-ray photoelectron spectroscopy. Sulfation of the perovskite leads to the formation of surface sulfite/sulfate and bulk-like sulfate species. Pd addition to LaMnO3and LaCoO3significantly increases the sulfur adsorption capacity. Pd/LaMnO3sample accumulates significantly more sulfur than LaMnO3; however it can also release a larger fraction of the accumulated SOxspecies in a reversible fashion at elevated temperatures in vacuum. This is not the case for Co-based materials, where thermal regeneration of bulk sulfates on poisoned LaCoO3and Pd/LaCoO3is extremely ineffective under similar conditions. However, in the presence of an external reducing agent such as H2(g), Pd/LaMnO3requires much lower temperature (873�K) for complete sulfur regeneration as compared to that of Pd/LaCoO3(973�K). Sequential CO and SOxadsorption experiments performed via in situ FTIR indicate that in the presence of carbonyls and/or carbonates, Pd adsorption sites may have a stronger affinity for SOxas compared to that of the perovskite surface, particularly in the early stages of sulfur poisoning. � 2016, Springer Science+Business Media New York
Sulfur-tolerant BaO/ZrO2/TiO2/Al2O3 quaternary mixed oxides for deNOX catalysis
Advanced quaternary mixed oxide materials in the form of BaO/Al2O3/ZrO2/TiO2 functionalized with Pt active sites (i.e. Pt/BaO/AZT) were synthesized and structurally characterized via XRD and BET in comparison to a conventional Pt/20BaO/Al benchmark NSR/LNT catalyst. The interactions of these catalysts' surfaces with SOx and NOx gases were monitored via in situ FTIR and TPD. There exists a delicate trade-off between NOx storage capacity (NSC) and sulfur uptake/poisoning which is strongly governed by the BaO loading/dispersion as well as the surface structure and acidity of the support material. Flow reactor measurements performed under realistic catalytic conditions show the high NOx activity for the Pt/20BaO/AZT catalyst at 573 K. After sulfur poisoning and subsequent regeneration at 773 and 973 K, Pt/20BaO/AZT surpassed the NOx catalytic performance at 573 K of all other investigated materials including the conventional Pt/20BaO/Al benchmark catalyst. � The Royal Society of Chemistry 2017
Aurora kinase A drives the evolution of resistance to third-generation EGFR inhibitors in lung cancer.
Although targeted therapies often elicit profound initial patient responses, these effects are transient due to residual disease leading to acquired resistance. How tumors transition between drug responsiveness, tolerance and resistance, especially in the absence of preexisting subclones, remains unclear. In epidermal growth factor receptor (EGFR)-mutant lung adenocarcinoma cells, we demonstrate that residual disease and acquired resistance in response to EGFR inhibitors requires Aurora kinase A (AURKA) activity. Nongenetic resistance through the activation of AURKA by its coactivator TPX2 emerges in response to chronic EGFR inhibition where it mitigates drug-induced apoptosis. Aurora kinase inhibitors suppress this adaptive survival program, increasing the magnitude and duration of EGFR inhibitor response in preclinical models. Treatment-induced activation of AURKA is associated with resistance to EGFR inhibitors in vitro, in vivo and in most individuals with EGFR-mutant lung adenocarcinoma. These findings delineate a molecular path whereby drug resistance emerges from drug-tolerant cells and unveils a synthetic lethal strategy for enhancing responses to EGFR inhibitors by suppressing AURKA-driven residual disease and acquired resistance
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