Mutations in Hepatitis D Virus Allow It to Escape Detection by CD8+ T Cells and Evolve at the Population Level

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The Y2K problem and management strategies for the individual practitioner

This article will detail concisely the nature of the Y2K problem, how it could affect your computer systems and your business, and what measures you can institute to minimize and/or eliminate computer failure as you enter the year 2000.     

Long-term effects of Le Fort I osteotomy for resection of juvenile nasopharyngeal angiofibroma on maxillary growth and dental sensation

OBJECTIVE: To analyze the long-term effects of the Le Fort I osteotomy approach for the resection of juvenile nasopharyngeal angiofibroma (JNA) on maxillary growth and dental sensation. DESIGN: Prospective collection of structured data. SETTING: Tertiary care academic teaching hospital. PATIENTS: Between 1993 and 1998, 5 adolescents (aged 10-14 years) constituted the evaluable cohort among 14 patients who underwent Le Fort I osteotomy for JNA resection. Mean follow-up was 47.2 months. INTERVENTIONS: The Le Fort I osteotomy approach was used to resect JNA. Cephalometric x-ray films were taken at various postoperative intervals to assess maxillary growth. The results were matched against age-correlated predictions from Dentofacial Planner software. MAIN OUTCOME MEASURES: Horizontal and vertical maxillary growth were each measured anteriorly and posteriorly by comparing interval postoperative cephalometric x-ray films. Dental sensation was longitudinally evaluated by performing interval pulp testing postoperatively. RESULTS: (1) Average vertical growth of the maxilla achieved 30% of predicted growth anteriorly (P =.02). (2) Average horizontal growth matched predicted growth in all patients. (3) All patients demonstrated long-term maxillary dental denervation. CONCLUSIONS: Le Fort I osteotomy provides excellent surgical exposure for resection of JNA in the growing facial skeleton. Although it significantly affects vertical but not horizontal growth, its cosmetic effect is negligible. It also causes long-term dental denervation, which in most cases is undetected by patients.     

Management and knowledge of enteral nutrition in intensive care units in a city in Belgium.

The administration of enteral nutrition in intensive care unit (ICU) patients is largely managed by nurses. However, the degree of knowledge, interest, and training in this field can differ considerably among nurses and among ICUs. Such differences may lead to variations in the way in which enteral nutrition is used. To investigate these issues, a questionnaire survey was sent to the nursing staffs of 5 ICUs in Belgium. The response rate was 68%. Although theoretical knowledge of enteral nutrition was globally poor, its advantages over parenteral nutrition were usually known. Responses to questions related to practical issues associated with enteral feeding showed more institution-specific answers than interindividual differences.     

Central facilitation of the glottic closure reflex in humans

The sphincteric function of the larynx, essential to lower airway protection, is most efficiently achieved through strong reflex adduction by both vocal cords. We hypothesize that central facilitation is an essential component of a bilateral adductor reflex and that its disturbance could result in weakened sphincteric closure. Five patients during supraglottic laryngectomy underwent evoked response laryngeal electromyography under 0.5 and 1.0 minimal alveolar concentration (MAC) isoflurane anesthesia. The internal branch of the superior laryngeal nerve was stimulated through bipolar platinum-iridium electrodes, and recording electrodes were positioned in the ipsilateral and contralateral thyroarytenoid muscles. Consistent threshold responses were obtained ipsilaterally from 0.5 to 1.0 MAC anesthesia. However, the contralateral reflex responses approached 0% in successive trials as anesthetic levels approached 1.0 MAC. In human subjects, alteration of central facilitation by deepening anesthesia abolishes the crossed adductor reflex, predisposing to a weakened glottic closure response. A precise understanding of this effect may improve the prevention of aspiration in patients emerging from prolonged sedation or under heavy psychotropic control.