The American journal of medicine
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In nephrogenic diabetes insipidus, the kidney is unable to concentrate urine despite normal or elevated concentrations of the antidiuretic hormone arginine vasopressin (AVP). In congenital nephrogenic diabetes insipidus (NDI), the obvious clinical manifestations of the disease, that is polyuria and polydipsia, are present at birth and need to be immediately recognized to avoid severe episodes of dehydration. Most (>90%) congenital NDI patients have mutations in the AVPR2 gene, the Xq28 gene coding for the vasopressin V2 (antidiuretic) receptor. ⋯ Similarly AQP2 mutant proteins are trapped intracellularly and cannot be expressed at the luminal membrane. The acquired form of NDI is much more common than the congenital form, is almost always less severe, and is associated with downregulation of AQP2. The advances described here are examples of "bedside physiology" and provide diagnostic tools for physicians caring for these patients.
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Chronic pain affects 75 million US citizens. A number of pharmacologic treatments are available for chronic pain that does not respond adequately to nonpharmacologic methods. Long the mainstay of chronic pain management, nonsteroidal anti-inflammatory drugs (NSAIDs) are known to be associated with gastrointestinal (GI) and renal toxicities, a particular problem for the elderly population, which commonly experiences chronic pain, such as that associated with osteoarthritis (OA). ⋯ Propoxyphene, widely believed to be safe and effective, may, in fact, be no more effective-and perhaps less effective-than acetaminophen or ibuprofen. A relatively new analgesic, tramadol, appears to be a useful therapy for patients who do not receive adequate pain relief with acetaminophen and are at risk for NSAID-related side effects. For localized chronic pain associated with OA, topical capsaicin is also an effective analgesic.
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The US Supreme Court recently upheld state laws in New York and Washington that prohibit assisted suicide. In both cases, the judgment of the Court was unanimous. Closer scrutiny of the opinions in the cases, however, suggests that we may not have seen the last of a federal constitutional right to assisted suicide.
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Within the past 2 decades, organ transplantation has become established as effective therapy for endstage renal, hepatic, cardiac, and pulmonary disease. Regimens to prevent rejection after transplantation commonly include high-dose glucocorticoids and calcineurin-calmodulin phosphatase inhibitors (the cyclosporines and tacrolimus), which are detrimental to bone and mineral homeostasis, and are associated with rapid bone loss that is often superimposed upon an already compromised skeleton. The incidence of fracture ranges from 8% to 65% during the first year after transplantation. ⋯ In patients with normal pretransplant bone density, therapy to prevent early posttransplant bone loss should be instituted immediately following transplantation. Most pharmacologic agents available for therapy of osteoporosis have not been subject to prospective controlled studies in organ transplant recipients. However, antiresorptive drugs, such as biphosphonates, appear to hold therapeutic promise.