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Additional Protection (additional + protection)
Selected AbstractsCommercial aviation in-flight emergencies and the physicianEMERGENCY MEDICINE AUSTRALASIA, Issue 1 2007Robert Cocks Abstract Commercial aviation in-flight emergencies are relatively common, so it is likely that a doctor travelling frequently by air will receive a call for help at some stage in their career. These events are stressful, even for experienced physicians. The present paper reviews what is known about the incidence and types of in-flight emergencies that are likely to be encountered, the international regulations governing medical kits and drugs, and the liability, fitness and indemnity issues facing ,Good Samaritan' medical volunteers. The medical and aviation literature was searched, and information was collated from airlines and other sources regarding medical equipment available on board commercial aircraft. Figures for the incidence of significant in-flight emergencies are approximately 1 per 10,40 000 passengers, with one death occurring per 3,5 million passengers. Medically related diversion of an aircraft following an in-flight emergency may occur in up to 7,13% of cases, but passenger prescreening, online medical advice and on-board medical assistance from volunteers reduce this rate. Medical volunteers may find assisting with an in-flight emergency stressful, but should acknowledge that they play a vital role in successful outcomes. The medico-legal liability risk is extremely small, and various laws and industry indemnity practices offer additional protection to the volunteer. In addition, cabin crew receive training in a number of emergency skills, including automated defibrillation, and are one of several sources of help available to the medical volunteer, who is not expected to work alone. [source] Induction of cellular resistance against Kupffer cell,derived oxidant stress: A novel concept of hepatoprotection by ischemic preconditioningHEPATOLOGY, Issue 2 2003Rolf J. Schauer Ischemic preconditioning (IP) triggers protection of the liver from prolonged subsequent ischemia. However, the underlying protective mechanisms are largely unknown. We investigated whether and how IP protects the liver against reperfusion injury caused by Kupffer cell (KC)-derived oxidants. IP before 90 minutes of warm ischemia of rat livers in vivo significantly reduced serum alanine aminotransferase (AST) levels and leukocyte adherence to sinusoids and postsinusoidal venules during reperfusion. This protective effect was mimicked by postischemic intravenous infusion of glutathione (GSH), an antioxidative strategy against KC-derived H2O2. Interestingly, no additional protection was achieved by infusion of GSH to preconditioned animals. These findings and several additional experiments strongly suggest IP mediated antioxidative effects: IP prevented oxidant cell injury in isolated perfused rat livers after selective KC activation by zymosan. Moreover, IP prevented cell injury and pertubations of the intracellular GSH/GSSG redox system caused by direct infusion of H2O2 (0.5 mmol/L). IP-mediated resistance against H2O2 could neither be blocked by the adenosine A2a antagonist DMPX nor mimicked by A2a agonist CGS21680. In contrast, H2O2 resistance was abolished by the p38 mitogen-activated protein kinase (p38 MAPK) inhibitor SB203580, but induced when p38 MAPK was directly activated by anisomycin. In conclusion, we propose a novel concept of hepatoprotection by IP: protection of liver cells by enhancing their resistance against KC-derived H2O2. Activation of p38 MAPK and preservation of the intracellular GSH/oxidized glutathione (GSSG) redox system, but not adenosine A2a receptor stimulation, seems to be pivotal for the development of H2O2 resistance in preconditioned livers. [source] The Role of Myocardial KATP -Channel Blockade in the Protective Effects of Glibenclamide against Ischaemia in the Rat HeartBASIC AND CLINICAL PHARMACOLOGY & TOXICOLOGY, Issue 2 2002Roger J. Legtenberg This study addresses the possible involvement of KATP channels in this beneficial action of glibenclamide. We hypothesized that if glibenclamide improved postischaemic cardiac function by blocking of KATP channels, opening of these KATP channels should result in the opposite, namely detrimental effects on postischaemic heart function. Postischaemic functional loss and coronary blood flow were recorded during treatment with glibenclamide (4 ,mol.l,1; n=5), the KATP channel openers pinacidil (1 ,mol.l,1; n=5) and diazoxide (30 ,mol.l,1; n=5), the combination of glibenclamide with pinacidil (n=5) and glibenclamide with diazoxide (n=5), and vehicle (n=8). Both pinacidil and diazoxide significantly increased coronary blood flow 2,3 times, which was abolished by glibenclamide pre- and postischaemically. This confirms that under both flow conditions glibenclamide significantly blocks KATP channels in the coronary vasculature. The 12 min. global ischaemic incident resulted in a cardiac functional loss of 22.2±2.9% during vehicle. Glibenclamide reduced the cardiac functional loss to 4.3±1.2% (P<0.01). Interestingly, both pinacidil and diazoxide reduced the cardiac functional loss to 4.0±1.5% (P<0.01) and 2.9±1.4% (P<0.001), respectively. The combination pinacidil+glibenclamide resulted in additional protection compared with the individual components (0.6±0.1 versus 4.0±1.5%, P<0.05). Thus, in contrast to its effect on coronary vascular tone, the glibenclamide-induced improvement of postischaemic cardiac function may not be mediated through blockade of the KATP channel. Alternative mechanisms may be operative, such as uncoupling of the mitochondrial respiratory chain, thereby preconditioning the hearts against stunning. [source] Anti-apoptotic effect of benidipine, a long-lasting vasodilating calcium antagonist, in ischaemic/reperfused myocardial cellsBRITISH JOURNAL OF PHARMACOLOGY, Issue 4 2001Feng Gao Ischaemia/reperfusion causes intracellular calcium overloading in cardiac cells. Administration of calcium antagonists reduces myocardial infarct size. Recent in vitro studies have demonstrated that calcium plays a critical role in the signal transduction pathway leading to apoptosis. However, whether or not calcium antagonists may reduce myocardial apoptosis induced by ischaemia-reperfusion, and thus decrease myocardial infarction, has not been directly investigated. The present study investigated the effects of benidipine, an L-type calcium channel blocker, on myocardial infarct size, apoptosis, necrosis and cardiac functional recovery in rabbits subjected to myocardial ischaemia/reperfusion (MI/R, 45 min/240 min). Ten minutes prior to coronary occlusion, rabbits were treated with vehicle or benidipine (10 ,g kg,1 or 3 ,g kg,1, i.v.). In the vehicle-treated group, MI/R caused cardiomyocyte apoptosis as evidenced by DNA ladder formation and TUNEL positive nuclear staining (12.2±1.1%). Treatment with 10 ,g kg,1 benidipine lowered blood pressure, decreased myocardial apoptosis (6.2±0.8%, P<0.01 vs vehicle) and necrosis, reduced infarct size (20±2.3% vs 49±2.6%, P<0.01), and improved cardiac functional recovery after reperfusion. Administering benidipine at 3 ,g kg,1, a dose at which no haemodynamic effect was observed, also exerted significant anti-apoptosis effects, which were not significantly different from those observed with higher dose benidipine treatment. However, treatment with this low dose benidipine failed to reduce myocardial necrosis. These results demonstrate that benidipine, a calcium antagonist, exerts significant anti-apoptosis effects, which are independent of haemodynamic changes. Administration of benidipine at a higher dose produced favourable haemodynamic effects and provided additional protection against myocardial necrotic injury and further improved cardiac functional recovery. British Journal of Pharmacology (2001) 132, 869,878; doi:10.1038/sj.bjp.0703881 [source] | ||||||||||