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Hypothermic Conditions (hypothermic + condition)
Selected AbstractsCorrelation and agreement between the bispectral index vs. state entropy during hypothermic cardio-pulmonary bypassACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 2 2010P. MEYBOHM Background: The bispectral index (BIS) and spectral entropy enable monitoring the depth of anaesthesia. Mild hypothermia has been shown to affect the ability of electroencephalography monitors to reflect the anaesthetic drug effect. The purpose of this study was to investigate the effect of hypothermia during a cardio-pulmonary bypass on the correlation and agreement between the BIS and entropy variables compared with normothermic conditions. Methods: This prospective clinical study included coronary artery bypass grafting patients (n=25) evaluating correlation and agreement (Bland,Altman analysis) between the BIS and both spectral and response entropy during a hypothermic cardio-pulmonary bypass (31,34 °C) compared with nomothermic conditions (34,37.5 °C). Anaesthesia was maintained with propofol and sufentanil and adjusted clinically, while the anaesthetist was blinded to the monitors. Results: The BIS and entropy values decreased during cooling (P<0.05), but the decrease was more pronounced for entropy variables compared with BIS (P<0.05). The correlation coefficients (bias±SD; percentage error) between the BIS vs. spectral state entropy and response entropy were r2=0.56 (1±11; 42%) and r2=0.58 (,2±11; 43%) under normothermic conditions, and r2=0.17 (10±12; 77%) and r2=0.18 (9±11; 68%) under hypothermic conditions, respectively. Bias was significantly increased under hypothermic conditions (P<0.001 vs. normothermia). Conclusion: Acceptable agreement was observed between the BIS and entropy variables under normothermic but not under hypothermic conditions. The BIS and entropy variables may therefore not be interchangeable during a hypothermic cardio-pulmonary bypass. [source] Influence of Temperature on the Liver Circadian Clock in the Ruin Lizard Podarcis siculaMICROSCOPY RESEARCH AND TECHNIQUE, Issue 7 2007Manuela Malatesta Abstract Reptiles represent an interesting animal model to investigate the influence of temperature on molecular circadian clocks. The ruin lizard Podarcis sicula lives in a continental climate and it is subjected to wide range of environmental temperatures during the course of the year. As consequence, ruin lizard daily activity pattern includes either the hibernation or periods of inactivity determined by hypothermia. Here we showed the rhythmic expression of two clock genes, lPer2 and lClock, in the liver of active lizards exposed to summer photo-thermoperiodic conditions. Interestingly, the exposition of lizards to hypothermic conditions, typical of winter season, induced a strong dampening of clock genes mRNA rhythmicity with a coincident decrease of levels. We also examined the qualitative and quantitative distribution of lPER2 and lCLOCK protein in different cellular compartments during the 24-h cycle. In the liver of active lizards both proteins showed a rhythmic expression profile in all cellular compartments. After 3 days at 6°C, some temporal fluctuations of the lCLOCK and lPER2 are still detectable, although, with some marked modifications in respect to the values detected in the liver of active lizards. Besides demonstrating the influence of low temperature on the lizard liver circadian oscillators, present results could provide new essential information for comparative studies on the influence of temperature on the circadian system across vertebrate classes. Microsc. Res. Tech., 2007. © 2007 Wiley-Liss, Inc. [source] Mild hypothermia inhibits IL-10 production in peripheral blood mononuclear cellsACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 2 2004T. Matsui Background:, Hypothermia is often associated with compromised host defenses and infections. Deterioration of immune functions related to hypothermia have been investigated, but the involvement of cytokines in host defense mechanisms and in infection remains unclear. Therefore, we determined whether mild hypothermia affects the production of several types of cytokines in peripheral blood mononuclear cells (PBMCs), and the balance between pro-inflammatory and anti-inflammatory states. Methods:, PBMCs obtained from 12 healthy humans were cultured with phytohemagglutinin (PHA) in normothermic (37°C: control) or hypothermic (33°C) conditions for 24 h. The production levels of tumor necrosis factor (TNF)-,, the interleukins (ILs) IL-6, IL-8 and IL-10, and interferon (IFN)-, in the culture supernatants were measured by means of enzyme-linked immunosorbent assay (ELISA). Results:, Under hypothermic conditions (33°C), PHA-induced production of IL-10 and IFN-, in PBMCs was significantly lower, by 34% and 84%, respectively, when compared with controls, while production of TNF-,, IL-6 and IL-8 did not change. The magnitude of reduction of IL-10 in hypothermic conditions resulted in IL-10/pro-inflammatory cytokine ratios decreasing to approximately 30,45% of those of controls. Conclusions:, The present study clearly demonstrates that mild hypothermia (33°C) inhibits IL-10 and IFN-, production in cultured PBMCs. The profound inhibition of IL-10 and the pro-inflammatory reaction-dominated state induced suggests that the host defense mechanism against secondary infection may be maintained rather than inhibited in hypothermia. Thus, the reduction of IL-10 could be an important characteristic of immune responses in mild hypothermia. [source] Organ culture, but not hypothermic storage, facilitates the repair of the corneal endothelium following mechanical damageACTA OPHTHALMOLOGICA, Issue 4 2010Jana Nejepinska Abstract. Purpose:, To evaluate the reparative capacity of the mechanically injured endothelium of corneas stored under organ culture (OC) or hypothermic conditions. Methods:, The central endothelium of 12 pairs of human corneas with similar endothelial parameters was damaged to create a 1 mm2 lesion. One cornea from each pair was stored under OC and one under hypothermic conditions. The endothelial cell density (ECD), coefficient of variation, hexagonality and percentage of dead cells were assessed before and after damage and on days 7, 14, 21 and 28 of storage. Results:, The mean ECD of corneas subsequently stored under OC or hypothermic conditions was 2764/mm2. Immediately after damage, a denuded Descemet's membrane with a few remaining dead cells was observed at the injured area. After 7 days of storage under OC conditions, almost no dead cells were observed at the place of injury. A non-significant worsening of the qualitative parameters (polymegatism and pleomorphism) was found. After 14 days, ECD was 1933/mm2 and 2478/mm2 centrally and pericentrally, respectively. Similar values were found after 21 and 28 days of storage. The lesions with remnant dead cells persisted throughout hypothermic preservation. From day 14 the corneas became cloudy and in poor condition, while the pericentral ECD was 2523/mm2. Conclusion:, The reparative capacity of the cornea is maintained under OC but not under hypothermic conditions. For corneas containing dead endothelial cells, OC is therefore the method of choice because it may improve the quality of the stored tissue. [source] | ||||||||||