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If the young of a dominant species are subjected to disproportionately heavy predation, this, together with a limitation on food, can promote a high species diversity. This is seen among tropical birds, which are simultaneously exposed to both conditions to a far greater degree than are Temperate Zone species. Migration to the Temperate Zones during the spring provides a release from these restraints, while also precluding breeding in the Tropics.  相似文献   
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Digestive Diseases and Sciences - Little is known about patient choice in treatment of eosinophilic esophagitis (EoE). Determine motivators and barriers to using common EoE therapies and describe...  相似文献   
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BACKGROUND: Cardiopulmonary bypass (CPB) is known to induce platelet activation, thrombosis, thrombocytopenia, and a systemic inflammatory response. It is known that CD40 ligand (CD40L) exists in platelets, that a soluble form of this protein (sCD40L) is released on platelet activation, that platelets are the primary source of sCD40L in blood, and that sCD40L is involved in thrombosis and inflammation. The present study was designed to determine whether sCD40L is released during CPB. Methods and Results- Blood was obtained from patients undergoing CPB-requiring surgery and analyzed for sCD40L, interleukin-6, and platelet factor 4 and beta-thromboglobulin (markers of platelet activation). Platelets were also isolated and analyzed for their levels of CD40L. Plasma levels of sCD40L increased >1.7-fold (from 0.29 to 0.51 ng/mL, P=0.001) within 1 hour on CPB and increased further to 3.7-fold (to 1.08 ng/mL, P=0.03) 2 hours after the procedure. Half of the released sCD40L was cleared in 2 hours, which allowed the sCD40L to return to approximately baseline levels 8 hours after the procedure. The platelet content of CD40L was decreased by 40% (2.675 to 1.64 ng/10(8) platelets, P=0.001) 1 hour after initiation of CPB and was similar to that observed for platelet factor 4 and beta-thromboglobulin. Interleukin-6, a marker of inflammation, also increased during CPB. CONCLUSIONS: The present study demonstrates that CPB causes an increase in the concentration of plasma sCD40L. The corresponding decrease in platelet CD40L suggests that this prothrombotic and proinflammatory protein was derived primarily from platelets and may contribute to the thrombotic and inflammatory complications associated with CPB.  相似文献   
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A syndrome of peripheral polyneuropathy associated with islet cell tumors and hypoglycemia has been reported in 28 patients. Despite varying features in these patients, the clinical characteristics of this syndrome are remarkably similar. These consist of the development of a sensorimotor neuropathy during a protracted course of recurrent severe hypoglycemia, related to underlying insulinoma. Cerebral symptoms dominate the clinical picture and a predominantly or entirely motor, distal and symmetric, peripheral neuropathy ensures. Upper limb involvement is more frequent, accompanied by severe weakness and distal wasting, usually without fasciculations. Painful distal paresthesias without objective sensory loss are characteristic. Direct relationship to a single hypoglycemic insult is often absent. This report describes the clinical features and laboratory investigation of a new case with this condition, reviews the literature and discusses the syndrome with special regard to the etiology.  相似文献   
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This ad hoc committee report from the American Geriatrics Society proposes the prompt initiation of Medicare reimbursement for geriatric assessment (GA) services (also termed comprehensive geriatric assessment or geriatric evaluation and management services). Despite an extensive body of literature documenting the effectiveness of GA for improving health care outcomes in many settings for identifiable groups of frail elderly patients, no explicit Medicare reimbursement mechanisms currently exist to cover GA services provided by either hospital or physician. We believe that new physician reimbursement codes specific for geriatric assessment should be established in the Current Procedural Technology (CPT-4) manual and that reimbursement for GA should be specifically provided under Part B of Medicare. Further, we believe that hospital reimbursement within the Medicare prospective payment system should be modified to encourage GA during inpatient stays for appropriate patients. This paper summarizes the background for these recommendations. It defines the major content of GA at three levels of intensity--screening, intermediate, and comprehensive. It describes the major sites for conducting GA--hospital, office, home, nursing home. Finally, it proposes criteria for targeting patients most likely to benefit from GA.  相似文献   
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