Medical hypotheses
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Oxidative stress underlies postoperative atrial fibrillation and electrophysiological remodelling associated with rapid atrial pacing. An increasing body of evidence indicates that the formation of reactive oxygen species (ROS) released following extracorporeal circulation are involved in the structural and functional myocardial impairment derived from the ischemia-reperfusion cycle. ROS behave as intracellular messengers mediating pathological processes, such as inflammation, apoptosis and necrosis, thereby participating in the pathophysiology of atrial fibrillation. ⋯ In turn, experimental studies have revealed that non-enzymatic antioxidants produce a significant functional amelioration in cardiomyocytes subjected to an oxidative challenge. Moreover, clinical studies with patients scheduled for primary coronary artery bypass graft surgery had a reduced incidence of postoperative atrial fibrillation. We present the hypothesis of non-hypoxic preconditioning based on the association of pretreatment with n-3 polyunsaturated fatty acids followed by ascorbate plus alpha-tocoferol supplementation diminishes the incidence of postoperative atrial fibrillation in patients subjected to cardiac surgery with extracorporeal circulation.
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The pathological role of the non-enzymatic modification of proteins by reducing sugars has become increasingly evident in various disorders. It is now well established that early glycation products undergo progressive modification over time in vivo to the formation of irreversible cross-links, after which these molecules are termed "AGEs (advanced glycation end products)". AGEs have been implicated in the development of many of the pathological sequelae of diabetes and aging, such as diabetic microangiopathy, ischemic heart disease and neurodegenerative diseases. ⋯ If our speculation is correct, AST-120 may have therapeutic potentials for the treatment of patients with various AGE-related disorders as well. In this paper, we would like to propose the possible ways of testing our hypotheses. Does the long-term treatment of AST-120 decrease serum and tissue levels of AGEs in diabetic patients? Does this treatment also reduce the risk for the development and progression of diabetic vascular complications such as diabetic retinopathy or ischemic heart disease? If the answers are yes, do the serum and/or tissue levels of AGEs after AST-120 treatment predict its beneficial effects on diabetic vascular complications? How about the effects of AST-120 on Alzheimer's disease, another AGE-related neurodegenerative disorder? Does the treatment of AST-120 reduce the risk for Alzheimer's disease and/or improve the cognitive impairment of patients with this disorder? These prospective studies will provide further valuable information whether the inhibition of absorption of dietary AGEs by AST-120 could be clinically relevant.
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Amniotic fluid embolism, a rare, sudden and often fatal illness of pregnancy may not be a true embolic event resulting from the physical obstruction of the pulmonary vasculature. The high degree of variability in symptoms, the lack of characteristic findings on radiological exam, the absence of a dose-response effect on symptoms, and the occasional occurrence of coagulopathies are not entirely consistent with a physical block to the circulation as the main mechanism of disease. Alternatively, it might be the result of complement activation initiated by fetal antigen leaking into the maternal circulation. ⋯ Direct measurement of serum complement as well as serum tryptase and urinary histamine are readily obtained tests in community hospitals as well as tertiary care hospitals. If the hypothesis proves true, this investigation may be of profound importance to understanding immune tolerance. Rather, than asking why one pregnant woman in 20,000 develops a violent immune reaction to the fetus, a better question is why do not all pregnant women reject the fetus which is a large collection of foreign antigens?
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The four science Nobel prizes (physics, chemistry, medicine/physiology and economics) have performed extremely well as a method of recognizing the highest level of achievement. The prizes exist primarily to honour individuals but also have a very important function in science generally. In particular, the institutions and nations which have educated, nurtured or supported many Nobel laureates can be identified as elite in world science. ⋯ I therefore suggest that the maximum of three laureates per year should always be awarded in the categories of physics, chemistry and economics, even when these prizes are for diverse and un-related achievements; that the number of laureates in the 'biology' category of physiology or medicine should be increased to six or preferably nine per year; and that two new Prize categories should be introduced to recognize achievements in mathematics and computing science. Together, these measures could increase the science laureates from a maximum of 12 to a minimum of 24, and increase the range of scientific coverage. In future, the Nobel committee should also officially allocate proportionate credit to institutions for each laureate, and a historical task force could also award institutional credit for past prizes.
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In a recent Medical Hypotheses editorial, I suggested the name psychological neoteny (PN) to refer to the widely-observed phenomenon that adults in modernizing liberal democracies increasingly retain many of the attitudes and behaviors traditionally associated with youth. I further suggested that PN is a useful trait for both individuals and the culture in modernizing societies; because people need to be somewhat child-like in their psychology order to keep learning, developing and adapting to the rapid and accelerating pace of change. Thirdly, I put forward the hypothesis that the major cause of PN in modernizing societies is the prolonged duration of formal education. ⋯ However, the economic effect is different in men and women: after parenthood men are more likely to have a job and work more hours while women change in the opposite direction. The conclusion is that psychological neoteny is indeed increasing, and mainly as a consequence of the increasing percentage of school leavers going into higher education. But at present it is unclear whether this trend is overall beneficial or harmful; and the answer may be different for men and women.