共查询到20条相似文献,搜索用时 15 毫秒
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Tuppy G 《Arquivos brasileiros de cardiologia》2002,78(6):598-599
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Opinion statement Gastroparesis, or delayed gastric emptying, is a common cause of chronic nausea and vomiting as seen in a gastroenterology
practice. Diabetic, postsurgical, and idiopathic causes remain the three most common forms of gastroparesis. In addition to
nausea and vomiting, symptoms of gastroparesis may include early satiety, postprandial fullness, and abdominal pain. Physiologic
changes that may explain symptoms in patients with gastroparesis, in addition to delayed gastric emptying, include impaired
fundic accommodation, antral hypomotility, gastric dysrhythmias, pylorospasm, and perhaps visceral hypersensitivity. Diagnosis
of gastroparesis is best determined using a radioisotope-labeled solid meal with scintigraphic imaging for at least 2 hours,
and preferably 4 hours, postprandially. Most commonly, a 99mTc sulfur colloid-labeled egg sandwich with imaging at 0, 1, 2,
and 4 hours is used. Extension of the gastric emptying test to 4 hours improves the accuracy of the test, but unfortunately,
this is not commonly performed at many centers. Emptying of liquids remains normal until the late stages of gastroparesis
and is less useful. The aims of treatment should be to control symptoms and maintain adequate nutrition and hydration. Patients
should be advised to eat small meals and to limit their intake of fat and fiber. Additional dietary recommendations may include
increasing caloric intake in the form of liquids. For diabetic patients, control of blood glucose levels is important, as
symptom exacerbation is frequently associated with poor glycemic control. Specific treatment often begins with metoclopramide,
10 mg, up to four times daily, after a discussion of possible side effects with the patient. An antiemetic agent, such as
prochlorperazine, 5 to 10 mg orally or 25 mg by suppository, can be added on an as-needed basis every 4 to 6 hours to control
nausea. If these antiemetic medications are not effective, or if side effects develop, orally dissolving ondansetron, 8 mg
every 8 to 12 hours, can be tried on an as-needed basis. If this regimen is unsuccessful, then alternative prokinetic agents—erythromycin,
125 mg, or tegaserod, 6 mg, prior to meals—can be tried. For cases refractory to these treatments, referral to a center with
US Food and Drug Administration permission to use domperidone should be considered. Alternatively, symptom modulators such
as low-dose tricyclic antidepressants can be tried to reduce symptoms, but these do not improve gastric emptying. In patients
for whom all medical therapy fails, other options that are tried at experienced centers include the injection of botulinum
toxin into the pylorus, placement of a feeding jejunostomy, and/or placement of a gastric electrical stimulator. 相似文献
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Energetic clues to pathways to biomineralization: precursors, clusters, and nanoparticles 总被引:1,自引:0,他引:1
Navrotsky A 《Proceedings of the National Academy of Sciences of the United States of America》2004,101(33):12096-12101
Nanoparticle and nanocluster precursors may play a major role in biomineralization. The small differences in enthalpy and free energy among metastable nanoscale phases offer controlled thermodynamic and mechanistic pathways. Clusters and nanoparticles offer concentration and controlled transport of reactants. Control of polymorphism, surface energy, and surface charge on nanoparticles can lead to morphological control and appropriate growth rates of biominerals. Rather than conventional nucleation and growth, assembly of nanoparticles may provide alternative mechanisms for crystal growth. The Ostwald step rule, based on a thermodynamic view of nucleation and growth, is supported by the observation that more metastable phases tend to have lower surface energies. Examples from nonbiological systems, stressing the interplay of thermodynamic and kinetic factors, illustrate features potentially important to biomineralization. 相似文献
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Pancreatic cystic lesions are being increasingly identified with the widespread use of state-of-the-art imaging. These lesions
are categorized into a broad range of neoplastic cysts and inflammatory pseudocysts. Identification of a pancreatic cyst requires
the clinician to focus on the main clinical challenge of the benign or malignant nature of the cyst. Neoplastic cysts range
the spectrum from benign, to premalignant, to frank malignancy. The management of these lesions is difficult, and the decision
to resect or observe a lesion is hampered by limitations in current imaging and tissue sampling techniques that prevent the
accurate characterization of all lesions. This article reviews current guidelines for the evaluation of pancreatic cystic
lesions, underscores the challenges posed by these lesions, and discusses current and future studies that will aid in patient
management. 相似文献
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Bindu Kanapuru 《The American journal of medicine》2009,122(7):605-613
There are inevitable physiologic changes associated with advancing age, yet for some people these changes are exaggerated, and as a result a phenotype emerges recognized as “frailty.” Why some people become frail and others do not remains incompletely understood. Although chronic illnesses are common among frail elderly persons, some will develop all of the phenotypic features without a diagnosed underlying disease. It has been recognized that certain proinflammatory cytokines and coagulation factors are elevated to a greater extent in those who are frail than in age-matched nonfrail individuals. In this review, we provide an overview of current research in the biology of frailty with particular emphasis on the role of inflammatory pathways and disordered coagulation in its pathogenesis. 相似文献
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Fafchamps M 《Proceedings of the National Academy of Sciences of the United States of America》2011,108(Z4):21308-21315
Economic development involves a structural transformation in the way people are allocated to tasks. There is a shift from self-provision to market exchange, facilitating specialization. There is also a shift from self-employment to wage employment in large firms and organizations, driven by innovation and increasing returns to scale. Changes in allocation mechanisms require changes in norms and attitudes. Because different labor assignment domains coexist, conflicts arise among norms that apply to different domains, possibly resulting in dysfunctional outcomes. I argue that religion, humanism, and schools have all played an important historical role in fostering the changes in social norms and attitudes that are needed to accompany structural changes in the way economies allocate workers to tasks. 相似文献
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《Focus (San Francisco, Calif.)》1999,14(6):5-6
The issue of the right to die in cases involving patients with HIV/AIDS is examined. Physician-assisted suicide is addressed along with issues pertaining to control and choice in the assisted dying debate. In particular, it is noted that there is an increasing awareness of an overriding desire for self-determination in most patients requesting an assisted death. The author argues that because death concentrates the mind and strips away superfluous concerns, the person dying probably knows which choices are best for him or her, and therefore, should be granted the final say. 相似文献
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