Unnecessary overuse. Study of "inadvisable practices" for patients with atrial fibrillation. / Sobreutilización innecesaria. Estudio de los «no hacer¼ en pacientes con fibrilación auricular.

OBJECTIVE: To identify overuse (diagnostic, therapeutic and self-care practices that represent risks that outweigh the potential benefits) in patients with atrial fibrillation. METHOD: The study was based on qualitative research techniques. Using the "Metaplan" technique, we identified and ordered potentially inappropriate, ineffective and inefficient practices. By means of a consensus conference, we then established a number of "inadvisable practice" measures (relatively common practices that should be eliminated based on the scientific evidence or clinical experience). Professionals from the specialties of cardiology, haematology, neurology, internal medicine, family medicine and nursing participated in the consensus. RESULTS: We developed a catalogue of 19 "inadvisable practices" related to the diagnosis, treatment and care of anticoagulated patients that were inappropriate, had questionable effectiveness or were ineffective, as well as 13 beliefs or behaviours for anticoagulated patients that could result in injury or were useless or inefficient. CONCLUSION: The "inadvisable practices" approach helps identify practices that represent greater risks than benefits for patients. It seems appropriate to include algorithms in the clinical decision-making support systems that consider this information for the diagnosis, treatment and for home care. For this last case, recommendations have also been prepared that define specific contents for the healthcare education of these patients.

Effects of seasonal and latitudinal cold on oxidative stress parameters and activation of hypoxia inducible factor (HIF-1) in zoarcid fish.

Acute, short term cooling of North Sea eelpout Zoarces viviparus is associated with a reduction of tissue redox state and activation of hypoxia inducible factor (HIF-1) in the liver. The present study explores the response of HIF-1 to seasonal cold in Zoarces viviparus, and to latitudinal cold by comparing the eurythermal North Sea fish to stenothermal Antarctic eelpout (Pachycara brachycephalum). Hypoxic signalling (HIF-1 DNA binding activity) was studied in liver of summer and winter North Sea eelpout as well as of Antarctic eelpout at habitat temperature of 0 degrees C and after long-term warming to 5 degrees C. Biochemical parameters like tissue iron content, glutathione redox ratio, and oxidative stress indicators were analyzed to see whether the cellular redox state or reactive oxygen species formation and HIF activation in the fish correlate. HIF-1 DNA binding activity was significantly higher at cold temperature, both in the interspecific comparison, polar vs. temperate species, and when comparing winter and summer North Sea eelpout. Compared at the low acclimation temperatures (0 degrees C for the polar and 6 degrees C for the temperate eelpout) the polar fish showed lower levels of lipid peroxidation although the liver microsomal fraction turned out to be more susceptible to lipid radical formation. The level of radical scavenger, glutathione, was twofold higher in polar than in North Sea eelpout and also oxidised to over 50%. Under both conditions of cold exposure, latitudinal cold in the Antarctic and seasonal cold in the North Sea eelpout, the glutathione redox ratio was more oxidised when compared to the warmer condition. However, oxidative damage parameters (protein carbonyls and thiobarbituric acid reactive substances (TBARS) were elevated only during seasonal cold exposure in Z. viviparus. Obviously, Antarctic eelpout are keeping oxidative defence mechanisms high enough to avoid accumulation of oxidative damage products at low habitat temperature. The paper discusses how HIF could be instrumental in cold adaptation in fish.

UV-B effects on Antarctic Chlorella sp cells.

Growth of Antarctic Chlorella sp cells was measured in cultures irradiated with 30 kJ m(-2) UV-B (280-320 nm). The specific growth rate immediately after the lag phase was 0.36+/-0.06 and 0.26+/-0.03 day(-1) for unirradiated cultures and cultures irradiated with UV-B, respectively, UV-B irradiation significantly decreased ascorbate content by 54.5%, and increased the ascorbyl radical content/ascorbate content ratio by 2.25-fold in algae cultures in log phase. UV-B exposure significantly decreased by 95, 62 and 71% the content of alpha-tocopherol, beta-carotene and total thiols, respectively, in cells in log phase of development. The cellular content of alpha-tocopherol, beta-carotene and total thiols was reduced by 78, 43 and 44%, respectively in stationary phase, as compared to the antioxidant content in the cells during log phase of development. UV-B exposure reduced the content of alpha-tocopherol and total thiols in stationary phase of development by 64 and 91%, respectively, as compared to unirradiated cells. The content of beta-carotene in stationary phase was not affected by UV-B exposure. The results presented here suggest that increased UV-B radiation was responsible for the development of oxidative stress conditions, assessed as the ascorbyl radical content/ascorbate content ratio, in Antarctic Chlorella sp cells. Moreover, a significant decrease in the content of both lipid and water soluble antioxidants might contribute to establish oxidative stress in the cells.