Determinant role of education in the ethical aspects of resuscitation: a German/Hungarian comparison

Introduction, objectives: Bioethical principles concerning Do Not Attempt Resuscitation (DNAR) orders are connected significantly with education according to our previous investigation. In order to confirm the hypothesis, Hungarian results were compared with the data gained from a highly qualified homogeneous group of German doctors, showing similar cultural traditions. Methods: The questionnaire investigated the factors influencing DNAR orders as functions of intensive medical experience, ideological view and professional education, using a 5-point visual analogue scale. Answers were assigned to categories of autonomy, futility, obtainable quality of life, resource utilization and a category of other factors detailed later. Results: The DNAR decision and termination of resuscitation are to almost the same extent determined by futility (3.29+-0.75; 3.49+-0.71) and obtainable quality of life (3.13+-1.31; 3.47+-1.34). The opinion of head of department was also important (3.24+-1.35; 3.23+-1.36). Patient's autonomy played an important role (3.15+-0.85; 2.36+-1.48) in decision making. In comparison with the Hungarian results, the only significant difference was found in the field of patient's autonomy in both not starting (p<0.0002) and terminating resuscitation (p<0.02) in favour of German doctors respecting it. Discussion: The results support the original hypothesis that consideration of modern bioethical principles, and especially the patient's autonomy are related to the level of the doctor's education. Comparing to Hungarian data there is only a minimal difference in other bioethical points, while the population of German doctors interviewed appreciated the patient's autonomy significantly higher. There should be greater discussion of ethical considerations in cardiopulmonary resuscitation education.     

Hypoxic oxygen fluctuations produce less severe retinopathy than hyperoxic fluctuations in a rat model of retinopathy of prematurity

The aim of this study was to investigate whether the mean around which arterial oxygen fluctuations take place was important in a unique animal model of oxygen-induced retinopathy. Retinopathy of prematurity (ROP) is associated with fluctuating arterial oxygen. A recent retrospective study suggested that management of high-risk preterm infants at lower oxygen saturations was associated with less severe ROP. Rat pups were raised in a variable oxygen environment around a high (24%), normal (21%) or low (17%) mean inspired oxygen for 14 d. Rat pups raised in the high (24%) mean variable oxygen environment had more retarded retinal vascular development than did rats raised in an environment that fluctuated around 21% mean oxygen. In contrast, rats raised in a lower mean (17%) but still variable oxygen environment had no discernible retinal differences from controls raised in constant room air. Rats raised in a relatively hypoxic but variable oxygen environment develop less severe retinal vascular abnormalities than those raised in variable oxygen around higher oxygen means.     

Alpha1-acid-glycoprotein protects against trauma-hemorrhagic shock

BACKGROUND: Recent studies have shown that the acute phase protein alpha(1)-acid-glycoprotein (AAG) directly modifies endothelial cell responsiveness and is a crucial factor for maintaining endothelial barrier function. We hypothesized that the addition of AAG to the resuscitation fluid will prevent edema formation, increases circulating blood volume, and reduces tissue inflammation following soft tissue trauma and hemorrhagic shock. MATERIALS AND METHODS: Male Sprague-Dawley rats (338 +/- 28 g) underwent a 5-cm midline laparotomy (i.e., induction of soft tissue trauma) and were bled to and maintained at a mean arterial pressure of 35 mm Hg for 90 min. The rats were then resuscitated with four times the shed blood volume with Ringer's lactate containing 200 mg/kg AAG or the same amount of albumin. At 6 h after resuscitation, organ wet-to-dry weight ratios and circulating blood volume (Evans blue dilution) were determined. Neutrophil accumulation (myeloperoxidase activity, MPO) and tissue lipid peroxidation (thiobarbituric acid reactive substances) were also measured in the lungs, liver, and intestine. RESULTS: Administration of AAG during the resuscitation significantly increased circulating blood volume and reduced edema formation, neutrophil accumulation, and lipid peroxidation. Interestingly, concomitant plasma IL-6 levels increased while TNF-alpha levels were not significantly affected. CONCLUSIONS: Since addition of AAG to the resuscitation fluid increased circulating blood volume, reduced edema formation, and neutrophil accumulation following trauma and hemorrhagic shock, supplementation of this acute phase protein appears to be a potential adjunct to prevent capillary leakage in patients undergoing major traumatic injury.     

The Ozobranchus leech is a candidate mechanical vector for the fibropapilloma-associated turtle herpesvirus found latently infecting skin tumors on Hawaiian green turtles (Chelonia mydas)

Fibropapillomatosis (FP) of marine turtles is a neoplastic disease of ecological concern. A fibropapilloma-associated turtle herpesvirus (FPTHV) is consistently present, usually at loads exceeding one virus copy per tumor cell. DNA from an array of parasites of green turtles (Chelonia mydas) was examined with quantitative PCR (qPCR) to determine whether any carried viral loads are sufficient to implicate them as vectors for FPTHV. Marine leeches (Ozobranchus spp.) were found to carry high viral DNA loads; some samples approached 10 million copies per leech. Isopycnic sucrose density gradient/qPCR analysis confirmed that some of these copies were associated with particles of the density of enveloped viruses. The data implicate the marine leech Ozobranchus as a mechanical vector for FPTHV. Quantitative RT-PCR analysis of FPTHV gene expression indicated that most of the FPTHV copies in a fibropapilloma have restricted DNA polymerase expression, suggestive of latent infection.     

Transport of ethinylestradiol glucuronide and ethinylestradiol sulfate by the multidrug resistance proteins MRP1, MRP2, and MRP3

Ethinylestradiol (EE) is one of the key constituents of oral contraceptives. Major metabolites of EE in humans are the glucuronide and sulfate conjugates, EE-3-O-glucuronide (EE-G) and EE-3-O-sulfate (EE-S). In the present study, transport of EE-G and EE-S by the human multidrug resistance proteins MRP1, MRP2, and MRP3 was investigated using inside-out membrane vesicles, isolated from Sf9 cells expressing human MRP1, MRP2, or MRP3. Vesicular uptake studies showed that EE-G was not a substrate for MRP1, whereas an ATP-dependent and saturable transport of [(3)H]EE-G was observed in MRP2 (K(m) of 35.1 +/- 3.5 microM) and MRP3 (K(m) of 9.2 +/- 2.3 microM) containing vesicles. EE-S was not transported by either MRP1, MRP2, or MRP3. However, low concentrations of EE-S stimulated MRP2-mediated uptake of ethacrynic acid glutathione. EE-S also stimulated MRP2 and MRP3-mediated uptake of 17beta-estradiol-17beta-D-glucuronide. Interestingly, EE-S stimulated strongly MRP2- and MRP3-mediated uptake of EE-G by increasing its apparent transport affinity, whereas no reciprocal stimulation of EE-S uptake by EE-G was observed. These data indicate that EE-S allosterically stimulates MRP2- and MRP3-mediated transport of EE-G and is not cotransported with EE-G. Our studies demonstrate specific active transport of a pharmacologically relevant drug conjugate by human MRP2 and MRP3, involving complex interactions with other organic anions. We also suggest that caution needs to be taken when using only competition studies as screening tools to identify substrates or inhibitors of MRP-mediated transport.     

Gender dimorphism in neutrophil priming and activation following trauma-hemorrhagic shock

Although gender influences T-cell, macrophage and organ functions following trauma-hemorrhage and resuscitation (T-H), it remains unknown whether it also influences polymorphonuclear cell (PMN) activity under such conditions. To study this, proestrus female and male Sprague-Dawley rats underwent trauma-hemorrhage followed by fluid resuscitation. Circulating PMNs were assessed for superoxide (O2-) and elastase production and tissues were analyzed for myeloperoxidase (MPO) activity and TBARS (thiobarbituric acid reactive substances) as a marker of oxidative injury, at 2 and 24 h after resuscitation. PMA stimulated O2- production was not influenced by T-H or gender. In contrast, fMLP-stimulated O2- and LPS-stimulated elastase release by PMNs from male T-H rats was greater than that of females. A significant MPO activity and TBARS in tissues of both male and female rats was induced; however, MPO activity and TBARS levels were higher in males following T-H. Levels of the chemokine CINC-1 were elevated in the lungs of male, but not of proestrus females after T-H. Thus, decreased PMN priming and activation in proestrus females, compared to males, occurs following T-H resulting in decreased cellular injury and organ damage that is likely to contribute to improved outcome under those conditions.     

Concentration dependent mitochondrial effect of amiodarone

Although, the antiarrhythmic effect of amiodarone is well characterized, its effect on post-ischemic heart and cardiomyocytes, as well as the mechanism of its toxicity on extracardiac tissues is still poorly understood. In this study, we analyzed energy metabolism in situ during ischemia-reperfusion in Langendorff-perfused heart model by measuring the high-energy phosphate metabolites using 31P NMR spectroscopy. The toxicity of amiodarone on cardiomyocytes and cell lines of extracardiac origin, as well as direct effect of the drug on mitochondrial functions in isolated mitochondria was also analyzed. Amiodarone, when was present at low concentrations and predominantly in membrane bound form, protected heart and mitochondrial energy metabolism from ischemia-reperfusion-induced damages in Langendorff-perfused heart model. Toxicity of the drug was significantly higher on hepatocytes and pancreatic cells than on cardiomyocytes. In isolated mitochondria, amiodarone did not induce reactive oxygen species formation, while it affected mitochondrial permeability transition in a concentration dependent way. Up to the concentration of 10 microM, the drug considerably inhibited Ca(2+)-induced permeability transition, while at higher concentrations it induced a cyclosporin A independent permeability transition of its own. At concentrations where it inhibited the Ca(2+)-induced permeability transition (IC(50)=3.9+/-0.8 microM), it did not affect, between 6 and 30 microM it uncoupled, while, at higher concentrations it inhibited the respiratory chain. Thus, the concentration dependent nature of amiodarone's effect on permeability transition together with the different sensitivities of the tissues toward amiodarone can be involved in the beneficial cardiac and the simultaneous toxic extracardiac effects of the drug.