Search results for "PROTECTION"
showing 10 items of 1623 documents
Cultural approach to the perception of risk: analysing concern about the siting of a high-level nuclear waste facility in Finland
1999
A study of local residents' attitudes toward the siting of a high-level nuclear waste facility in Finland was undertaken in three municipalities (Eurajoki, Kuhmo and Aänekoski) that are being considered possible host communities for the facility. The results of the survey show that opposition to the facility is quite strong in two of the three municipalities, while in the third a polarization of opinions into two opposing camps is evident. The size, social structure and substance of the local opposition and support are analysed. The thesis of the paper is that in order to understand different opinions about the facility, one must understand the cultural logic of risk perception. People eva…
Oestrogen receptor subtype-specific repression of calpain expression and calpain enzymatic activity in neuronal cells - implications for neuroprotect…
2006
Calpains represent a superfamily of Ca2+-activated cysteine-proteases, which are important mediators of apoptosis and necrosis. In the brain, m-calpain and micro-calpain, the two ubiquitous calpain-isoforms, are strongly activated in neurones after an excitotoxic Ca2+ influx occurring, for example, during cerebral ischemia. Because oestrogen and its receptors (ERalpha/ERbeta) can exert neuroprotective activity, we investigated their influence on expression of calpains and their endogenous inhibitor, calpastatin. We found that ectopic expression of ERalpha in human neuroblastoma SK-N-MC cells led to a ligand-independent constitutive down-regulation of m-calpain accompanied by an up-regulatio…
Inhibition of intracellular Ca2+ release by a Rho-kinase inhibitor for the treatment of ischemic damage in primary cultured rat hippocampal neurons.
2008
The effects of hydroxy fasudil, a specific Rho-kinase inhibitor, on behavior and brain neuronal activity in animal studies have been described previously. However, whether a Rho-kinase inhibitor can directly protect neurons against ischemic damage and the molecular mechanisms underlying these effects are poorly understood. The present work was designed to investigate the effect of hydroxy fasudil against oxygen-glucose deprivation (OGD) induced acute neuronal injury and the underlying mechanisms in vitro. Pretreatment with hydroxy fasudil at 5 and 10 microM could concentration-dependently improve cell viability and decrease Lactate dehydrogenase (LDH) level in extracellular solution of neur…
Radiation exposure to the hands and the thyroid of the surgeon during intramedullary nailing.
1998
Abstract During 41 procedures of intramedullary nailing of femoral and tibial fractures, the primary surgeon and the first assistant wore ring dosimeters on their dominant index fingers. While the average fluoroscopy time per procedure was 4.6 min, the average dose of radiation to the dominant hand of the primary surgeon was 1.27 mSv and 1.19 mSv to the first assistant. The dose limit for the extremities is 500 mSv per year, as recommended by the International Commission on Radiological Protection. Extrapolation of the mean dose of the primary surgeon and first assistent per procedure of 1.23 mSv leads to the result that the recommended dose limit of 500 mSv would only be exceeded if more t…
Neuroprotective Actions of Estradiol and Novel Estrogen Analogs in Ischemia: Translational Implications
2010
This review highlights our investigations into the neuroprotective efficacy of estradiol and other estrogenic agents in a clinically relevant animal model of transient global ischemia, which causes selective, delayed death of hippocampal CA1 neurons and associated cognitive deficits. We find that estradiol rescues a significant number of CA1 pyramidal neurons that would otherwise die in response to global ischemia, and this is true when hormone is provided as a long-term pretreatment at physiological doses or as an acute treatment at the time of reperfusion. In addition to enhancing neuronal survival, both forms of estradiol treatment induce measurable cognitive benefit in young animals. Mo…
Myocardial Protection by Retrograde Cardioplegic Perfusion in the Presence of Acute Coronary Artery Obstruction: An Experimental Study
1992
To investigate retrograde delivery of cardioplegic solutions as a means of enhancing myocardial protection in the presence of coronary artery occlusion, a two-part experimental model was devised. In part 1 (in vitro) the possibility of retroperfusing the entire myocardium during acute occlusion of the left anterior descending artery (LAD) was assessed. In part 2 (in vivo) acute LAD occlusion was performed in dogs, and during 2 hours of aortic cross-clamping crystalline cardioplegic solution was infused at 20-minute intervals. In group I the infusion was antegrade, via the aortic root, and in group II it was retrograde, via the coronary sinus. Thereafter the LAD snare was released and the do…
Impaired border zone formation and adverse remodeling after reperfused myocardial infarction in cannabinoid CB2 receptor deficient mice.
2014
Abstract Aims Reperfusion of myocardial infarction is associated with inflammatory reaction and subsequent myocardial remodeling with a rapid scar formation in mice. The cannabinoid receptor CB2 has been associated with cardioprotection and regulation of macrophage function. We investigated its role in remodeling of reperfused infarction. Main methods One hour LAD-occlusion was followed by reperfusion over 6 h and 1, 3 and 7 days in wild-type C57/BL6J (WT) and CB2 receptor-deficient (Cnr2 −/− ) mice (n = 8/group). Hearts were processed for functional, morphological and mRNA/protein analysis, and tissue concentration of endocannabinoids was determined using liquid chromatography-multiple rea…
The CB1 cannabinoid receptor mediates excitotoxicity-induced neural progenitor proliferation and neurogenesis.
2007
Endocannabinoids are lipid signaling mediators that exert an important neuromodulatory role and confer neuroprotection in several types of brain injury. Excitotoxicity and stroke can induce neural progenitor (NP) proliferation and differentiation as an attempt of neuroregeneration after damage. Here we investigated the mechanism of hippocampal progenitor cell engagement upon excitotoxicity induced by kainic acid administration and the putative involvement of the CB1 cannabinoid receptor in this process. Adult NPs express kainate receptors that mediate proliferation and neurosphere generation in vitro via CB1 cannabinoid receptors. Similarly, in vivo studies showed that excitotoxicity-induce…
How acute physical and psychological stress differentially influence the kynurenine pathway: A randomized cross-over trial.
2021
Abstract Psychological stress is associated with the pathogenesis of several neuropsychiatric disorders. In contrast, physical stress, as provoked by exercise, counteracts symptoms and potentially also disease progression. The kynurenine pathway, which is imbalanced in neuropsychiatric disorders, responds to both psychological and physical stress. Here, we compared the acute effects of psychological versus physical stress on the kynurenine pathway and inflammatory mediators. Thirty-five healthy males (mean age: 24.09±3.39 years) underwent both the Trier Social Stress Test (psychological stressor) and the Wingate-Test (physical stressor). The kinetics of tryptophan and its metabolites as wel…
Radiation transmission data for radionuclides and materials relevant to brachytherapy facility shielding
2008
To address the limited availability of radiation shielding data for brachytherapy as well as some disparity in existing data, Monte Carlo simulation was used to generate radiation transmission data for 60Co, 137CS, 198Au, 192Ir 169Yb, 170Tm, 131Cs, 125I, and 103pd photons through concrete, stainless steel, lead, as well as lead glass and baryte concrete. Results accounting for the oblique incidence of radiation to the barrier, spectral variation with barrier thickness, and broad beam conditions in a realistic geometry are compared to corresponding data in the literature in terms of the half value layer (HVL) and tenth value layer (TVL) indices. It is also shown that radiation shielding calc…