Medical hypotheses
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Delirium is a common pathologic event in both medical and surgical patients. It is essential to note that patients who develop delirium have worse long term outcomes. The etiology and pathogenesis of delirium are extremely complex and not entirely understood. ⋯ These studies should adjust for such common confounders as patients' demographics and age, comorbid conditions, use of other medications, type of surgery, baseline cognitive status, etc. Another important task would be to research the susceptibility for propofol-related delirium. By studying these critical questions, we will gain additional insights into the complex etiology and pathobiology of delirium in addition to a better understanding of the pharmacology of propofol.
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The worldwide incidence of traumatic spinal cord injury (SCI) is approximated at 180,000 new cases per year. Experiments using nonhuman primates (NHP) are often used to replicate the human condition in order to advance the understanding of SCI and to assist in the development of new treatments. ⋯ However, spinal cord lesions that are created with a sharp instrument in NHP experiments may not replicate the clinical and pathological features of human spinal cord injury. Researchers should recognize the challenges associated with making clinical inferences in human SCIs based on NHP experiments that created experimental lesions with a sharp surgical instrument.
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Consensus in the most recent literature indicates that psychoactive "bath salts" is a relatively new drug-combination that was added to Schedule I classification in October 2011. Common ingredients include the cathinone analogs: mephedrone and methylenedioxypyrovalerone (MDPV). The mechanism of action of these synthetic cathinone analogs has not yet been well studied. ⋯ The null hypothesis, that cathinones do not cause neurotoxicity to dopamine nerve endings of the striatum, seems parsimonious and requires intensive investigation. Our hypothesis is that when consumed by humans, cathinones may induce neurotoxic pathways involving the neuro-glial-microglia and/or specific inflammation, that may help explain the clinically observed delayed response. We intend to explore this hypothesis utilizing a novel proteomic and biomarker technique developed by scientists at the McKnight Brain Institute, University of Florida as well as magnetic-resonance imaging across pre-frontal orbital cortex-cingulate gyrus and mesolimbic pathways of the brain of rodents.
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Several lines of evidence have indicated that rapamycin acts as an inhibitor of mammalian target of rapamycin (mTOR) and this produces therapeutic benefits as a treatment for Alzheimer's disease (AD) by activating an autophagic pathway. Similarly, postoperative cognitive dysfunction (POCD) is a decline in cognitive function for weeks or months after surgery. ⋯ We therefore hypothesized that rapamycin may have a therapeutic effect to relieve POCD. Inhibition of mTOR induces autophagic effect, thereby leading to a slower aging process, so this would be a novel target for the prevention and treatment of POCD.
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The oxygen saturation of the systemic arterial blood is associated with the adequacy of respiration, and can be measured non-invasively by pulse oximetry in the systemic tissue. The oxygen saturation of the blood in the pulmonary artery, the mixed venous blood, reflects the balance between oxygen supply to the systemic tissues and their oxygen demand. The mixed venous oxygen saturation has also clinical significance because it is used in Fick equation for the quantitative measurement of cardiac output. ⋯ The pulmonary photoplethysmographic curves reflect blood volume increase during systole in the pulmonary arteries in the lung tissue, which contain mixed venous blood. The ratio R of the amplitude-to-baseline ratio for the two wavelengths is related to the mixed venous oxygen saturation through equations derived for the systemic pulse oximetry. The method requires the use of extinction coefficients values for oxygenated and deoxygenated hemoglobin, which can be found in the literature.