2,907 research outputs found
Hypoglossal schwannoma masquerading as a carotid body tumor.
Study Objective. To describe the clinical presentation, evaluation, and treatment of a hypoglossal schwannoma. Methods. We report an unusual case of a hypoglossal schwannoma presenting as a pulsatile level II neck mass at the bifurcation of the external and internal carotid arteries, mimicking a carotid body tumor. Radiologic findings are reviewed in detail. Results. A 59-year-old female presented to a tertiary care medical center with complaints of a pulsatile right-sided neck mass. An MRA of the neck was obtained demonstrating a 5 cm mass located at the carotid artery bifurcation and causing splaying of the internal and external carotids. Based on clinical presentation and imaging, a diagnosis of a carotid body tumor was conferred and the patient scheduled for excision. Intraoperatively, the mass was noted to arise from the hypoglossal nerve, remaining independent of the carotid artery. On histopathologic analysis, the mass was determined to be consistent with hypoglossal schwannoma. Conclusion. Though rare, the hypoglossal schwannoma should remain a consideration in the evaluation of a parapharyngeal space mass. As this report demonstrates, the clinical and radiologic presentation of a hypoglossal schwannoma may closely mimic that of the more common carotid body tumor
OncoLog Volume 44, Number 12, December 1999
Collaboration Between Scientists, Clinicians Moves Apoptosis Studies Forward
Answering the Who, What, and How of Medical Physics
USHERING IN NEW TECHNOLOGIES: Medical Physicists Focus on IMRT, Ultrasound-Guided Brachytherapy
DiaLog: Building Better Patient Care on the Foundation of Scientific Research, by John Mendelsohn, MD, President, Professor of Clinical Investigation
House Call: Make Cancer Prevention Part of Your New Year\u27s Resolutionshttps://openworks.mdanderson.org/oncolog/1080/thumbnail.jp
Validity of values for metabolic equivalents of task during submaximal all-extremity exercise and reliability of exercise responses in frail older adults
Background and Purpose. Physical therapists and rehabilitation professionals in hospital and long-term care centers are using all-extremity semirecumbent exercise machines in their treatment programs. This study was undertaken to investigate the concurrent validity of values for software-generated metabolic equivalents of task (MET) from an all-extremity semirecumbent exercise machine and directly measured values for MET from a portable metabolic unit across a range of submaximal exercise intensities. A second purpose of this study was to determine the test-retest reliability of oxygen consumption and heart rate responses in older adults between standardized sessions of submaximal all-extremity aerobic exercise. Subjects and Methods. The study participants were 18 older adults (mean age=82 years, SD=5; 3 women, 15 men) who were living in long-term care centers and who completed 2 test sessions of a standardized exercise protocol 1 week apart. The exercise protocol included a warm-up period, three 4-minute stages of exercise at incremental workload levels, and a cool-down period. The breath-by-breath metabolic data from the portable metabolic unit, heart rate, MET values from the exercise machine, Borg Rating of Perceived Exertion, and watts were recorded continuously throughout the exercise protocol. Results. The concurrent validity of the MET values from the exercise machine and the portable metabolic unit ranged from very good to excellent on both day 1 and day 2 (r=.85-.97). The test-retest reliability of subjects\u27 heart rate responses and MET values from the portable metabolic unit was moderate to high across submaximal exercise intensities (intraclass correlation coefficients [2,1]=.85-.91). Discussion and Conclusion. The exercise machine software-generated MET values were representative of directly measured oxygen consumption values across a range of submaximal intensities during all-extremity semirecumbent exercise in older adults with multisystem impairments. © 2008 American Physical Therapy Association
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Praxis Origins
The co-founders of the writing center studies journal Praxis look back on the origins of the journal, the role it played in their early careers as writing center administrators, and the way they wanted it to shape theory/practice in the field. Today, Praxis continues to evolve in response to the vision its editors bring and the changes they see in our disciplinary landscape
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Agents of Change: African American Contributions to Writing Centers
African Americans and their contributions to our field’s first pedagogical models and operational structures are absent from writing center histories. This archival research invokes their presence by recounting the stories of five African American innovators—Bess Bolden “B. B.” Walcott, Coragreene Johnstone, Anne Cooke, Hugh Gloster, and Percival Bertrand “Bert” Phillips—spanning four decades at three historically Black colleges and universities (HBCUs). Their stories invite an expansive understanding of writing center work, moving beyond a focus on traditional tutoring and strictly alphabetic literacies and into “strategic literacies”—the survival skills needed to stand up for oneself and one’s community in the face of dangerous times and violently racist places. The writing center leaders described here saw writing as a tool to be used in concert with embodied performances for expression and survival to advance struggles for labor equity, legal justice, and civil rights. This conception of writing center work springs from sites of research such as HBCU archives and popular Black press archives that are less often examined by dominant disciplinary histories. From those sites, a timeline of African American writing center administrators emerges that spurs further research of these under-studied figures, who together constitute a remarkable legacy.
Keywords: writing center studies, historically Black colleges and universities, composition studies history, higher educatio
Developmental expression of retinoic acid receptors (RARs)
Here, I review the developmental expression features of genes encoding the retinoic acid receptors (RARs) and the 'retinoid X' or rexinoid receptors (RXRs). The first detailed expression studies were performed in the mouse over two decades ago, following the cloning of the murine Rar genes. These studies revealed complex expression features at all stages of post-implantation development, one receptor gene (Rara) showing widespread expression, the two others (Rarb and Rarg) with highly regionalized and/or cell type-specific expression in both neural and non-neural tissues. Rxr genes also have either widespread (Rxra, Rxrb), or highly-restricted (Rxrg) expression patterns. Studies performed in zebrafish and Xenopus demonstrated expression of Rar and Rxr genes (both maternal and zygotic), at early pre-gastrulation stages. The eventual characterization of specific enzymes involved in the synthesis of retinoic acid (retinol/retinaldehyde dehydrogenases), or the triggering of its catabolism (CYP26 cytochrome P450s), all of them showing differential expression patterns, led to a clearer understanding of the phenomenons regulated by retinoic acid signaling during development. Functional studies involving targeted gene disruptions in the mouse, and additional approaches such as dominant negative receptor expression in other models, have pinpointed the specific, versus partly redundant, roles of the RARs and RXRs in many developing organ systems. These pleiotropic roles are summarized hereafter in relationship to the receptors’ expression patterns
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