39 research outputs found
Modulation of the UV-B-induced Oxidative Stress and Apoptosis in HaCaT Cell Line with Calluna vulgaris Extract
The reactive oxygen species (ROS) production due to ultraviolet B (UV-B) exposure is extremely harmful to the skin. It causes lesions of DNA, proteins and lipids and leads to cellular death. In the present study the UV-B-induced ROS and subsequent apoptosis in the human keratinocyte cell line (HaCaT) were counterbalanced by a plant extract with antioxidant capacity. Some molecules modulated by common heather (Calluna vulgaris) (CV) extract through which this may exert its photoprotective effects were also identified. The ROS were evaluated with CM-H2DCFDA assay, while apoptosis and Bax-α/Bcl-xL molecules with ELISA. The extract was standardized according to its polyphenolic content and the most important biologically active compounds, such as hyperozid, quercetin, isoquercetin, kampferol were evidenced by high-performance liquid chromatography. The UV-B induced ROS production occurred at its highest level at 2 h after the exposure of the HaCaT cells, while apoptosis later, at 4 h. The most significant changes in Bax-α and Bcl-XL proteins induced by UV-B, as well as the highest effect of the extract on apoptosis, were both registered at 4 h. The CV extract decreased concentration- and time-dependently the UV-B-induced ROS production and prevented apoptosis. These effects of CV occurred, at least to a certain extent, due to the modulation of Bax-α/Bcl-XL proteins. These findings suggest that skin cells could be protected from some of the UV-B-induced harmful effects by the administration of the CV extract, which may be further exploited as a potential photoprotective agent
Ubiquitous robust communications for emergency response using multi-operator heterogeneous networks
A number of disasters in various places of the planet have caused an extensive loss of lives, severe damages to properties and the environment, as well as a tremendous shock to the survivors. For relief and mitigation operations, emergency responders are immediately dispatched to the disaster areas. Ubiquitous and robust communications during the emergency response operations are of paramount importance. Nevertheless, various reports have highlighted that after many devastating events, the current technologies used, failed to support the mission critical communications, resulting in further loss of lives. Inefficiencies of the current communications used for emergency response include lack of technology inter-operability between different jurisdictions, and high vulnerability due to their centralized infrastructure. In this article, we propose a flexible network architecture that provides a common networking platform for heterogeneous multi-operator networks, for interoperation in case of emergencies. A wireless mesh network is the main part of the proposed architecture and this provides a back-up network in case of emergencies. We first describe the shortcomings and limitations of the current technologies, and then we address issues related to the applications and functionalities a future emergency response network should support. Furthermore, we describe the necessary requirements for a flexible, secure, robust, and QoS-aware emergency response multi-operator architecture, and then we suggest several schemes that can be adopted by our proposed architecture to meet those requirements. In addition, we suggest several methods for the re-tasking of communication means owned by independent individuals to provide support during emergencies. In order to investigate the feasibility of multimedia transmission over a wireless mesh network, we measured the performance of a video streaming application in a real wireless metropolitan multi-radio mesh network, showing that the mesh network can meet the requirements for high quality video transmissions
Serum osteoprotegerin level, carotid-femoral pulse wave velocity and cardiovascular survival in haemodialysis patients
BACKGROUND: Osteoprotegerin (OPG) is a marker and regulator of
arterial calcification, and it is related to cardiovascular
survival in haemodialysis patients. The link between OPG and
aortic stiffening--a consequence of arterial calcification--has
not been previously evaluated in this population, and it is not
known whether OPG-related mortality risk is mediated by arterial
stiffening. METHODS: At baseline, OPG and aortic pulse wave
velocity (PWV) were measured in 98 chronic haemodialysis
patients who were followed for a median of 24 months. The
relationship between OPG and PWV was assessed by multivariate
linear regression. The role of PWV in mediating OPG related
cardiovascular mortality was evaluated by including both OPG and
PWV in the same survival model. RESULTS: At baseline mean
(standard deviation) PWV was 11.2 (3.3) m/s and median OPG
(interquartile range) was 11.1 (7.5-15.9) pmol/L. There was a
strong, positive, linear relationship between PWV and lnOPG (P =
0.009, model R(2) = 0.540) independent of covariates. During
follow-up 23 patients died of cardiovascular causes. In separate
univariate survival models both PWV and lnOPG were related to
cardiovascular mortality [hazard ratios 1.31 (1.14-1.50) and
8.96 (3.07-26.16), respectively]. When both PWV and lnOPG were
entered into the same model, only lnOPG remained significantly
associated with cardiovascular mortality [hazard ratio 1.11
(0.93-1.33) and 7.18 (1.89-27.25), respectively). CONCLUSION: In
haemodialysis patients OPG is strongly related to PWV and OPG
related cardiovascular mortality risk is, in part, mediated by
increased PWV
Comparison of markers of oxidative stress, inflammation and arterial stiffness between incident hemodialysis and peritoneal dialysis patients – an observational study
Background: Patients on peritoneal and hemodialysis have accelerated atherosclerosis associated with an increase in cardiovascular morbidity and mortality. The atherosclerosis is associated with increased arterial stiffness, endothelial dysfunction and elevated oxidative stress and inflammation. The aims of this study are to investigate the effects of peritoneal and hemodialysis on arterial stiffness, vascular function, myocardial structure and function, oxidative stress and inflammation in incident patients with end stage kidney disease
Nocturnal Hypoxia and Loss of Kidney Function
Background: Although obstructive sleep apnea (OSA) is more common in patients with kidney disease, whether nocturnal hypoxia affects kidney function is unknown. Methods: We studied all adult subjects referred for diagnostic testing of sleep apnea between July 2005 and December 31 2007 who had serial measurement of their kidney function. Nocturnal hypoxia was defined as oxygen saturation (SaO2) below 90 % for 4 ml/min/1.73 m2 per year. Results: 858 participants were included and followed for a mean study period of 2.1 years. Overall 374 (44%) had nocturnal hypoxia, and 49 (5.7%) had accelerated loss of kidney function. Compared to controls without hypoxia, patients with nocturnal hypoxia had a significant increase in the adjusted risk of accelerated kidney function loss (odds ratio (OR) 2.89, 95 % confidence interval [CI] 1.25, 6.67). Conclusion: Nocturnal hypoxia was independently associated with an increased risk of accelerated kidney function loss. Further studies are required to determine whether treatment and correction of nocturnal hypoxia reduces loss of kidney function
Work orientations, well-being and job content of self-employed and employed professionals
Drawing on psychology-derived theories and methods, a questionnaire survey compared principal kinds of work orientation, job content and mental well-being between self-employed and organisationally employed professional workers. Self-employment was found to be particularly associated with energised well-being in the form of job engagement. The presence in self-employment of greater challenge, such as an enhanced requirement for personal innovation, accounted statistically for self-employed professionals’ greater job engagement, and self-employed professionals more strongly valued personal challenge than did professionals employed in an organisation. However, no between-role differences occurred in respect of supportive job features such as having a comfortable workplace. Differences in well-being, job content and work orientations were found primarily in comparison between self-employees and organisational non-managers. The study emphasises the need to distinguish conceptually and empirically between different forms of work orientation, job content and well-being, and points to the value of incorporating psychological thinking in some sociological research
