Intensive care medicine experimental
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Intensive Care Med Exp · Dec 2014
'Chronomics' in ICU: circadian aspects of immune response and therapeutic perspectives in the critically ill.
Complex interrelations exist between the master central clock, located in the suprachiasmatic nuclei of the hypothalamus, and several peripheral clocks, such as those found in different immune cells of the body. Moreover, external factors that are called 'timekeepers', such as light/dark and sleep/wake cycles, interact with internal clocks by synchronizing their different oscillation phases. Chronobiology is the science that studies biologic rhythms exhibiting recurrent cyclic behavior. ⋯ The aims of this article are to describe circadian physiology during acute stress and to discuss the effects of ICU milieu upon circadian rhythms, in order to emphasize the value of considering circadian-immune disturbance as a potential tool for personalized treatment. Thus, besides neoplastic processes, critical illness could be linked to what has been referred as 'chronomics': timing and rhythm. In addition, different therapeutic perspectives will be presented in association with environmental approaches that could restore circadian connection and hasten physical recovery.
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Intensive Care Med Exp · Dec 2014
Effect of PEEP on breath sound power spectra in experimental lung injury.
Acute lung injury (ALI) is known to be associated with the emergence of inspiratory crackles and enhanced transmission of artificial sounds from the airway opening to the chest wall. Recently, we described the effect of ALI on the basic flow-induced breath sounds, separated from the crackles. In this study, we investigated the effects of positive end-expiratory pressure (PEEP) on these noncrackling basic lung sounds augmented during ALI. ⋯ We confirm a gravity-related spectral amplitude increase of basic flow-induced breath sounds recorded over lung regions affected by permeability-type pulmonary edema and show that such changes are reversible by alveolar recruitment with PEEP.
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Intensive Care Med Exp · Dec 2013
Activated protein C ameliorates impaired renal microvascular oxygenation and sodium reabsorption in endotoxemic rats.
We aimed to test whether continuous recombinant human activated protein C (APC) administration would be able to protect renal oxygenation and function during endotoxemia in order to provide more insight into the role of coagulation and inflammation in the development of septic acute kidney injury. ⋯ Renal sodium reabsorption is closely correlated to renal microvascular oxygenation during endotoxemia. In this study, fluid resuscitation and APC supplementation were not significantly effective in protecting renal microvascular oxygenation and renal function. The specific mechanisms responsible for these effects of APC warrant further study.
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Intensive Care Med Exp · Dec 2013
Effects of the PPAR-β/δ agonist GW0742 during resuscitated porcine septic shock.
In un-resuscitated rodent models of septic shock, the peroxisome proliferator-activated receptor-β/δ (PPAR-β/δ) agonist GW0742 improved visceral organ function. Therefore, we tested the hypothesis whether GW0742 would attenuate kidney injury during long-term, resuscitated, porcine polymicrobial septic shock. ⋯ In swine with pre-existing atherosclerosis, the PPAR-β/δ agonist GW0742 failed to attenuate septic shock-induced circulatory failure and kidney dysfunction, most likely due to reduced receptor expression coinciding with cardiovascular and metabolic co-morbidity.
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Intensive Care Med Exp · Dec 2013
Adrenomedullin binding improves catecholamine responsiveness and kidney function in resuscitated murine septic shock.
Adrenomedullin (ADM) has been referred to as a double-edged sword during septic shock: On one hand, ADM supplementation improved organ perfusion and function, attenuated systemic inflammation, and ultimately reduced tissue apoptosis and mortality. On the other hand, ADM overproduction can cause circulatory collapse and organ failure due to impaired vasoconstrictor response and reduced myocardial contractility. Since most of these data originate from un-resuscitated shock models, we tested the hypothesis whether the newly developed anti-ADM antibody HAM1101 may improve catecholamine responsiveness and thus attenuate organ dysfunction during resuscitated murine, cecal ligation and puncture (CLP)-induced septic shock. ⋯ During resuscitated murine septic shock, early ADM binding with HAM1101 improved catecholamine responsiveness, blunted the shock-related impairment of energy metabolism, reduced nitrosative stress, and attenuated systemic inflammatory response, which was ultimately associated with reduced kidney dysfunction and organ injury.