228 resultados para Occupant protection devices.
Resumo:
In vitro, Toll-like receptors (TLR)2, 4 and 9 as well as NOD-like receptor 2 critically determine macrophage responses to Mycobacterium tuberculosis (Mtb) infection. However, in low-dose experimental murine tuberculosis, single or multiple deficiencies in TLRs 2, 4, 9 or NOD2 have little, if any, impact on early mycobacterial growth containment, granuloma formation and survival. Here, we analyzed the relevance of NALP3, one component of the danger-signaling inflammasome, for (i) Mtb-induced cytokine secretion in vitro and in vivo, (ii) restriction of Mtb replication in infected organs and (iii) granuloma formation. In the absence of functional NALP3, there was no IL-1beta and IL-18 production in Mtb-infected dendritic cells and macrophages in vitro, whereas secretion of IL-1alpha, IL-12p40 and TNF remained unaffected. After three weeks of infection, NALP3-deficient as well as IL-18-deficient mice were as capable as wildtype mice of restricting Mtb loads at a plateau level within well-differentiated granulomas. In conclusion, despite its involvement in cytokine processing, NALP3 is not essential for induction of protective immunity to Mtb.
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Background: Temporary percutaneous left ventricular assist devices (TPLVAD) can be inserted and removed in awake patients. They substitute left ventricular function for a period of up to a few weeks and provide an excellent backup and bridge to recovery or decision. Methods: Retrospective analysis of 75 patients who received TPLVAD to treat cardiogenic shock (n = 49) or to facilitate high-risk percutaneous coronary intervention (PCI) (n = 26). Forty-two patients with cardiogenic shock and 16 patients with high-risk PCI received a TandemHeart and 7 patients and 10 patients, respectively, received an Impella Recover LP 2.5. Outcome and related complications up to 1 month are reported with reference to device depending function. Results: One-month survival was 53% in patients with shock and 96% in patients with PCI. Conclusion: TPLVADs can support the failing heart with acceptable risk. Outcome is better in prophylactic use than in patients with cardiogenic shock. (C) 2011 Wiley-Liss, Inc.
Resumo:
L-Type Ca(2+) and K(ATP) Channels in Pacing-Induced Cardioprotection. AIMS: The L-type Ca(2+) channel, the sarcolemmal (sarcK(ATP)), and mitochondrial K(ATP) (mitoK(ATP)) channels are involved in myocardial preconditioning. We aimed at determining to what extent these channels can also participate in pacing-induced cardioprotection. METHODS: Hearts of 4-day-old chick embryos were paced in ovo during 12 hour using asynchronous intermittent ventricular stimulation at 110% of the intrinsic rate. Sham operated and paced hearts were then submitted in vitro to anoxia (30 minutes) and reoxygenation (60 minutes). These hearts were exposed to L-type Ca(2+) channel agonist Bay-K-8644 (BAY-K) or blocker verapamil, nonselective K(ATP) channel antagonist glibenclamide (GLIB), mitoK(ATP) channel agonist diazoxide (DIAZO), or antagonist 5-hydroxydecanoate. Electrocardiogram, electromechanical delay (EMD) reflecting excitation-contraction (E-C) coupling, and contractility were determined. RESULTS: Under normoxia, heart rate, QT duration, conduction, EMD, and ventricular shortening were similar in sham and paced hearts. During reoxygenation, arrhythmias ceased earlier and ventricular EMD recovered faster in paced hearts than in sham hearts. In sham hearts, BAY-K (but not verapamil), DIAZO (but not 5-hydroxydecanoate) or GLIB accelerated recovery of ventricular EMD, reproducing the pacing-induced protection. By contrast, none of these agents further ameliorated recovery of the paced hearts. CONCLUSION: The protective effect of chronic asynchronous pacing at near physiological rate on ventricular E-C coupling appears to be associated with subtle activation of L-type Ca(2+) channel, inhibition of sarcK(ATP) channel, and/or opening of mitoK(ATP) channel.
Resumo:
Hypoglycemia, if recurrent, may have severe consequences on cognitive and psychomotor development of neonates. Therefore, screening for hypoglycemia is a daily routine in every facility taking care of newborn infants. Point-of-care-testing (POCT) devices are interesting for neonatal use, as their handling is easy, measurements can be performed at bedside, demanded blood volume is small and results are readily available. However, such whole blood measurements are challenged by a wide variation of hematocrit in neonates and a spectrum of normal glucose concentration at the lower end of the test range. We conducted a prospective trial to check precision and accuracy of the best suitable POCT device for neonatal use from three leading companies in Europe. Of the three devices tested (Precision Xceed, Abbott; Elite XL, Bayer; Aviva Nano, Roche), Aviva Nano exhibited the best precision. None completely fulfilled the ISO-accuracy-criteria 15197: 2003 or 2011. Aviva Nano fulfilled these criteria in 92% of cases while the others were <87%. Precision Xceed reached the 95% limit of the 2003 ISO-criteria for values ≤4.2 mmol/L, but not for the higher range (71%). Although validated for adults, new POCT devices need to be specifically evaluated on newborn infants before adopting their routine use in neonatology.
Resumo:
Peroxisome proliferator-activated receptor gamma (PPAR-gamma) is a member of the nuclear hormone superfamily originally characterized as a regulator of adipocyte differentiation and lipid metabolism. In addition, PPAR-gamma has important immunomodulatory functions. If the effect of PPAR-gamma's activation in T-cell-mediated demyelination has been recently demonstrated, nothing is known about the role of PPAR-gamma in antibody-induced demyelination in the absence of T-cell interactions and monocyte/macrophage activation. Therefore, we investigated PPAR-gamma's involvement by using an in vitro model of inflammatory demyelination in three-dimensional aggregating rat brain cell cultures. We found that PPAR-gamma was not constitutively expressed in these cultures but was strongly up-regulated following demyelination mediated by antibodies directed against myelin oligodendrocyte glycoprotein (MOG) in the presence of complement. Pioglitazone, a selective PPAR-gamma agonist, partially protected aggregates from anti-MOG demyelination. Heat shock responses and the expression of the proinflammatory cytokine tumor necrosis factor-alpha were diminished by pioglitazone treatment. Therefore, pioglitazone protection seems to be linked to an inhibition of glial cell proinflammatory activities following anti-MOG induced demyelination. We show that PPAR-gamma agonists act not only on T cells but also on antibody-mediated demyelination. This may represent a significant benefit in treating multiple sclerosis patients.
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Abstract Background: Clinical research in the field of hypertension is now increasingly focusing on the potential effects of antihypertensive treatments that may go beyond the reduction of blood pressure (BP). In particular, renal protection appears as a desirable goal, especially considering that hypertension is associated with an increased risk of developing kidney damage, which may eventually lead to end-stage renal disease and a higher mortality. Dihydropyridine calcium channel blockers (CCBs) are widely used in the field of hypertension therapy but the different renal effects of the various CCBs have been poorly explored to date. Scope: This review will discuss available evidence on the renal effects of two calcium channel blockers: amlodipine and lercanidipine, on the basis of clinical data. Methods: MEDLINE and EMBASE were searched for inclusion of relevant studies. No limitations in time were considered. Results: Results from preclinical and clinical studies suggest that amlodipine is overall less effective in terms of renal protection when compared with other antihypertensive tested agents. Its beneficial effect in retarding the progression of renal disease is achievable only when combined with a blocker of the renin-angiotensin system. Conversely lercanidipine seems to provide renal protection in a similar way to ACE inhibitors, probably thanks to its mechanism of action which acts directly on the afferent and efferent renal arterioles. Conclusions: Treatment of hypertension with CCBs should take into consideration the special effects of each single agent at different levels; lercanidipine for example may play a useful role in the management not only of hypertension but also in renal protection of hypertensive patients.
Resumo:
Hypoglycaemia is a major cause of neonatal morbidity and may induce long-term developmental sequelae. Clinical signs of hypoglycaemia in neonatal infants are unspecific or even absent, and therefore, precise and accurate methods for the assessment of glycaemia are needed. Glycaemia measurement in newborns has some particularities like a very low limit of normal glucose concentration compared to adults and a large range of normal haematocrit values. Many bedside point-of-care testing (POCT) systems are available, but literature about their accuracy in newborn infants is scarce and not very convincing. In this retrospective study, we identified over a 1-year study period 1,324 paired glycaemia results, one obtained at bedside with one of three different POCT systems (Elite? XL, Ascensia? Contour? and ABL 735) and the other in the central laboratory of the hospital with the hexokinase reference method. All three POCT systems tended to overestimate glycaemia values, and none of them fulfilled the ISO 15197 accuracy criteria. The Elite XL appeared to be more appropriate than Contour to detect hypoglycaemia, however with a low specificity. Contour additionally showed an important inaccuracy with increasing haematocrit. The bench analyzer ABL 735 was the most accurate of the three tested POCT systems. Both of the tested handheld glucometers have important drawbacks in their use as screening tools for hypoglycaemia in newborn infants. ABL 735 could be a valuable alternative, but the blood volume needed is more than 15 times higher than for handheld glucometers. Before daily use in the newborn population, careful clinical evaluation of each new POCT system for glucose measurement is of utmost importance.
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This prospective study applies an extended Information-Motivation-Behavioural Skills (IMB) model to establish predictors of HIV-protection behaviour among HIV-positive men who have sex with men (MSM) during sex with casual partners. Data have been collected from anonymous, self-administered questionnaires and analysed by using descriptive and backward elimination regression analyses. In a sample of 165 HIV-positive MSM, 82 participants between the ages of 23 and 78 (M=46.4, SD=9.0) had sex with casual partners during the three-month period under investigation. About 62% (n=51) have always used a condom when having sex with casual partners. From the original IMB model, only subjective norm predicted condom use. More important predictors that increased condom use were low consumption of psychotropics, high satisfaction with sexuality, numerous changes in sexual behaviour after diagnosis, low social support from friends, alcohol use before sex and habitualised condom use with casual partner(s). The explanatory power of the calculated regression model was 49% (p<0.001). The study reveals the importance of personal and social resources and of routines for condom use, and provides information for the research-based conceptualisation of prevention offers addressing especially people living with HIV ("positive prevention").