The News Focus story “Second thoughts about CT imaging” (L. Schenkman, 25 February, p. [1002][1]) describes the theoretical risk of low-dose radiation from computed tomography (CT), the growing use of CT in medical practice, and its use (and presumed overuse) in the diagnosis of appendicitis,
PURPOSE: Reports of fatality related toClostridium difficilecolitis and a sharp increase in prevalence of this infection prompted a study of patients who develop a more aggressive form of this disease. METHODS: Over 38 months, 710 patients at our institution developedC. difficilecolitis. Twenty-one (3 percent) of these patients either required intensive care unit admission or died as a result of their infection. A retrospective, case-controlled study was undertaken to compare these patients, who were considered to have severeC. difficilecolitis, with the remaining patients with milder disease. RESULTS: Factors that predisposed to the development of severeC. difficilecolitis included intercurrent malignancy, chronic obstructive pulmonary disease, immunosuppressive and antiperistaltic medications, renal failure, and administration of clindamycin (P< 0.05 for all). Patients with severeC. difficilecolitis were more likely to have abdominal pain, tenderness and distention, peritonitis, hemoconcentration (>5 points), hypoalbuminemia (<3 mg/dl), and elevated or suppressed white blood cell count (>25,000; <1,500; P< 0.05 for all). These factors were used to create a scoring system that could distinguish between patients with severeC. difficilecolitis and those with mild disease. Thirteen patients in the late stages of terminal illness with metastatic malignancy or age >90 were considered poor or inappropriate surgical candidates. Only the remaining eight patients could have potentially recovered from operation with hope for long-term survival. Of these, seven were treated without colonic resection, and six of the seven survived, whereas one patient underwent colectomy and did not survive. CONCLUSIONS: Patients with severeC. difficilecolitis can be readily identified. Often they have coexisting illness that precludes operation. In this series, only 1 of 21 patients with severeC. difficilemight have benefited from an aggressive surgical approach.
SYNOPSIS. The genie control of the development of neural morphology and specific neural connections is little known, primarily because of a paucity of neurological mutants in animal models suitable for experimental manipulation. However, by using cell markers—such as tetraploidy, a large cell marker whose development is described here—the development of single retinal cells in tetraploid embryos, the growth of marked polyclones in chimeric eyes, and the central connections of various chimeric eyes have been analyzed to identify the strategies used in molding eye morphology and establishing precise central connections. Theoretical models and computer simulations were used to draw inferences about the information used to accomplish the identified strategies. This analysis resulted in predictions about the sorts of mutant genes which might be found to affect neural ontogeny.
Background: Pectus excavatum is an anomaly of chest wall development in which anterior ribs curve inward and the sternum is displaced toward the vertebral column. The Nuss procedure is a minimally invasive technique in which one or more metal bars are implanted to brace the sternum in a corrected position. Over time, the chest wall remodels into an anatomically corrected shape and the bar(s) are removed at a later date. During the procedure, passage of an introducer instrument and then the repair bar(s) may shear the intercostal muscles from the adjacent ribs. This creates larger than necessary defects in the chest wall, improper or unstable bar placement, and inadequate repair. Instrument Design: We report a new surgical instrument for guiding the introducer through the contralateral chest wall. This capture-guidance instrument (CGI) redirects and channels forces to keep the introducer true while preventing muscle stripping during passage of the introducer and repair bar(s). Instrument Use: The CGI has been piloted at two pectus centers with a notable decrease in intercostal muscle stripping. Conclusion: The CGI addresses the problem of shear and intercostal muscle stripping during traversal of the chest as part of Nuss repair of pectus excavatum.
Thymoma is an uncommon tumor of childhood. Stage of the tumor is an independent prognostic factor for survival. Surgery is the treatment of choice for stage I and stage II tumors. Chemotherapy is reserved for patients with refractory or metastatic disease. Thymomas are moderately radiosensitive. However, radiation therapy is not an attractive option for children due to its side-effects on developing organs. The authors describe 2 children with completely encapsulated thymoma who were successfully treated with surgery alone. Both patients remain free of disease 3 years after surgery. One of the patients also has nevus sebaceous. The authors also discuss the possible association between the two disease entities.
Pectus excavatum (PE) and pectus carinatum (PC) are the most common congenital chest wall anomalies. Current research suggests that PE and PC may result from overgrowth of the sternocostal cartilages. This can produce a deformation that displaces the sternum inward as in PE or outward as in PC. The etiology, clinical presentation, evaluation, and management of PE and PC are reviewed. Varied clinical presentations, cardiopulmonary effects, and psychosocial aspects are described.
