The American journal of medicine
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The action of smooth muscle in the intestinal wall produces tonic contractions that maintain organ dimension against an imposed load such as a bolus of food, as well as forceful contractions that produce muscle shortening to propel the bolus along the gastrointestinal tract. These functions are regulated by intrinsic electrical and mechanical properties of smooth muscle. The complex signaling process that underlies these functions is discussed in this article. We propose a model that describes the facilitation of sustained contraction of smooth muscle cells in the gut.
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Dyspnea in a patient with cancer may have several causes, including infection, thromboembolism, metastases, and therapeutically induced cardiopulmonary disease. Pulmonary tumor embolism is an uncommon cause. ⋯ Unfortunately, microscopic tumor embolism is recognized rarely before death because of difficulty in establishing the diagnosis. We provide a review of the literature about the evaluation and diagnosis of this rare clinical entity.
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Essential tremor is a common movement disorder that affects between 5 and 10 million persons in the United States. It is characterized primarily by an action and postural tremor most often affecting the arms, but it can also affect other body parts. Essential tremor is a progressive neurologic disorder and can cause substantial disability in some patients. ⋯ Other medications with potential efficacy include benzodiazepines, gabapentin, topiramate, and botulinum toxin. Patients with medication-resistant tremor may benefit from thalamotomy or deep brain stimulation of the thalamus. The use of medical and surgical therapies can provide benefit in up to 80% of patients with essential tremor.