Medical hypotheses
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Myositis-myalgia is the most common cause of statin intolerance, leading to cessation of statin use, with consequent failure to lower LDL cholesterol to target levels for primary and secondary prevention of cardiovascular disease (CVD). We hypothesize that symptomatic myositis-myalgia in hypercholesterolemic statin-treated patients with concurrent 25 (OH) vitamin D deficiency and statin intolerance may reflect a reversible interaction between vitamin D deficiency and statins on skeletal muscle. In hypercholesterolemic, vitamin D deficient patients, intolerant to statins because of myositis-myalgia, three non-blinded clinical case series have uniformly demonstrated that after supplementation with oral vitamin D2 which normalizes serum 25 (OH) vitamin D levels, statins can be successfully re-instituted in >90% of patients, without recurrent myositis-myalgia, with reduction of LDL cholesterol to target levels. ⋯ A placebo-controlled, double-blind study is needed to document that normalization of serum 25 (OH) vitamin D levels in vitamin D deficient, statin intolerant patients would facilitate re-introduction of statins with concurrent freedom from myositis-myalgia. The ability to reverse myositis-myalgia in vitamin D deficient, statin intolerant, hypercholesterolemic patients by vitamin D supplementation would be extraordinarily valuable, facilitating reinstitution of statins to lower LDL cholesterol to reduce risk of CVD events. We hypothesize that symptomatic myositis-myalgia in hypercholesterolemic statin-treated patients with concurrent vitamin D deficiency producing statin intolerance may reflect a reversible interaction between vitamin D deficiency and statins on skeletal muscle.
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This paper discusses a current misinterpretation between different parameters of hemoglobin concentration measurement and its amplification under conditions of blood loss. The paper details the distinction between microcirculatory hematocrit and the hematocrit of the macrocirculation to analyze clinical use of real-time patient hemoglobin concentration measurement by noninvasive point-of-care devices such as the Rainbow Pulse CO-Oximetry™ (Masimo Corp., Irvine, CA). The hemoglobin concentration or hematocrit values have clinical significance such as for diagnosing anemia or as indicators to when a blood transfusion is needed. ⋯ The claim of this paper is that under conditions of blood loss the portion of the SpHb total hemoglobin measure that is contributed from microcirculation increases, due to the decrease of macro hematocrit while microcirculatory hematocrit remains constant when above a critical value. The device is calibrated from phlembotomy drawn blood (from a vein in the arm), which is the gold standard in blood collection, and hence this changing contribution of microcirculatory hemoglobin to the SpHb value would distort the gap between macro hemoglobin and total hemoglobin, SpHb. The hypothesis is that if clinicians indeed interpret the SpHb values as macro hemoglobin values then there is an unreported discrepancy between SpHb to macro hemoglobin concentrations during blood loss due to the increasing effect of microcirculatory hemoglobin measurement on the mixed parameter, SpHb.
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Less than 20 years after Herrick described the first case, the cold was proposed as having a role in precipitating pain in sickle cell disease. Numerous publications focus on weather changes, in particular exposure to the cold, and their association with vaso-occlusive (painful) episodes. Whereas several theories have been proposed to explain the association, a plausible hypothesis based on our current understanding of the pathophysiology of pain has not been offered. ⋯ This hypothesis represents a paradigm shift in understanding, as well as explaining at least some of the pain experience in sickle cell disease, and should be the impetus to further determine the characteristics of those patients who develop allodynia and hyperalgesia to cold weather. Whereas some researchers have suggested that those with sickle cell disease may have neuropathic pain, including a report from our own ongoing study [1], it has not been well accepted nor has it been applied in understanding pain associated with sickle cell disease. The conceptual shift and new understanding is important to develop preventive strategies, apply pain therapies new to the sickle cell population, and view pain in sickle cell disease in the context of a chronic disease.
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Glaucoma is one of the leading causes of irreversible blindness. Primary open-angle glaucoma (POAG), the most common type, is a progressive optic neuropathy with characteristic structural changes in the optic nerve head and functional changes in the visual field. Mechanical and vascular theories for the pathogenesis of glaucomatous optic neuropathy have been proposed. ⋯ A decreased ICP could result in an increased trans-lamina cribrosa pressure difference (IOP minus ICP) and lead to glaucomatous damage. In the present paper, we raise the question of whether ICP fluctuations also may be important in glaucoma. The effect of ICP fluctuation might be comparable to that of IOP fluctuation, which has been recognized as an independent risk factor for glaucoma progression.
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We hypothesize that supplemental inhaled nitric oxide (iNO) will improve outcomes in children with severe malaria receiving standard antimalarial therapy. The rationale for the hypothesized efficacy of iNO rests on: (1) biological plausibility, based on known actions of NO in modulating endothelial activation; (2) pre-clinical efficacy data from animal models of experimental cerebral malaria; and (3) a human trial of the NO precursor l-arginine, which improved endothelial function in adults with severe malaria. iNO is an attractive new candidate for the adjunctive treatment of severe malaria, given its proven therapeutic efficacy in animal studies, track record of safety in clinical practice and numerous clinical trials, inexpensive manufacturing costs, and ease of administration in settings with limited healthcare infrastructure. We plan to test this hypothesis in a randomized controlled trial (ClinicalTrials.gov Identifier: NCT01255215).