Articles: cations.
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The authors undertook a review of the literature and analysis of the local surgical experience for lumbar stenosis to define the role of simultaneous arthrodesis in the treatment of patients undergoing decompression for spinal stenosis. The restrained use of spinal fusion is recommended in spinal stenosis surgery because of the coexisting medical problems in the elderly patient population and the higher associated complication rate with spinal fusion and instrumentation. ⋯ Spinal fusion is not recommended for a routine decompressive laminectomy for lumbar stenosis or in the case of stable degenerative deformities. New fusion techniques may improve the outcome and decrease the morbidity associated with contemporary methods of spinal fusion and instrumentation.
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This paper introduces an Associative List Memory (ALM) that has high recall fidelity with low memory and low processing requirements. This permits a simple implementation in software on a personal computer or space instrument microprocessor. Associative List Memory has a performance comparable with Sparse Distributed Memory (SDM) but differs from SDM in that convergence occurs during learning, rather than on recall, and in that the memory is in the form of a dynamic list rather than static randomly distributed locations. ⋯ Its processing times on a personal computer are found to be practical for database applications. Implemented within a space instrument processor, ALM would greatly reduce downlink data transmission rates. Copyright 1997 Elsevier Science Ltd.
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To contribute to a better understanding of the prognostic differences between atypical and malignant meningiomas as defined by the World Health Organization (WHO) and the influence of the grade of initial surgical excision on postoperative course, 42 cases of atypical and 29 of malignant meningioma were studied, along with long-term follow up. The two groups were compared with respect to long-term survival, recurrence-free survival, and median time to recurrence. The prognostic significance of the Simpson grade of surgical resection and tumor location was also considered. ⋯ In conclusion, the current study shows that for most patients with atypical meningioma the prognosis was less severe than for those with malignant meningioma, but the risk of a downhill course resulting from malignancy after incomplete resection and recurrence was not negligible (26%). In addition, the WHO classification was found to be inadequate for a minority of the atypical meningioma cases, which currently have the same unfavorable course as cases of malignant meningioma. The results also indicate that objective Simpson Grade I extirpation of convexity meningiomas can be successful despite histological findings of malignancy.
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A 6-day-old female presented with vomiting and an abdominal mass. At laparotomy, a pyloroduodenal duplication cyst was enucleated from the pyloric region. Of the diagnostic studies performed, IV cholangiography with spiral computed tomography and an upper gastrointestinal barium study were useful in the preoperative differential diagnosis.
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Perioperative complications in obstructive sleep apnea (OSA) patients are described in a small series of case reports. No study to date systematically evaluates perioperative complications in a large number of OSA patients receiving surgeries other than those involving the pharynx. ⋯ The incidence of respiratory complications related to difficulties in airway management in OSA patients was higher than that reported in a recent study for all patients receiving general anesthesia (4%). The perioperative complications observed in these OSA patients are consistent with the underlying pathogenesis of OSA, pharyngeal obstruction. The absence of observed perioperative arrhythmias and myocardial ischemia is consistent with previous findings that sleep-related cardiac ischemia is uncommon in OSA patients. Our results suggest it is prudent to cautiously manage all OSA patients receiving surgeries involving general anesthesia.