Duplication of the cervical esophagus in children

True duplication of the cervical esophagus is rare. An 18-month-old girl presented with a large asymptomatic neck mass, which was found to be an intramural duplication of the esophagus. The evaluation and treatment of this patient is presented as well as a review of the six previously reported cases.     

The microstructure of ultra-high molecular weight polyethylene used in total joint replacements

The microstructure of ultra-high molecular weight polyethylene (UHMWPE) has been studied using a range of techniques. Both the unprocessed base powder and ram-extruded polymer have been examined using optical microscopy, scanning and transmission electron microscopy and small-angle light scattering. By examining the microstructure of samples compression moulded at a range of temperatures, techniques have been developed to assess the degree of consolidation of the processed polymer. The raw polymer is a powder with a particle size in the range 50-250 microm. These particles are themselves agglomerates of much finer particles typically 0.5-1 microm in size. It has been suggested that these sub-micron particles may be the origin of the sub-micron wear debris found in tissues around total joint replacements. However, examination of the ram-extruded polymer, from which implants are machined, shows a different structure from the powder, with no evidence of retention of the 0.5-1 microm structure seen in the powder in the processed material. It thus appears that the similarity in size between the sub-micron wear debris particles and the fine structure seen in the unprocessed UHMWPE resin is coincidental. Processed UHMWPE does show a 'memory' of the grain boundaries between powder particles and the degree of consolidation can be assessed by observing the distinctiveness of these boundaries.     

The relation between rhinitis and allergic asthma. The action of antihistaminics on bronchial hyperreactivity

The intermediate filament nestin is highly expressed in multipotential stem cells of the developing central nervous system (CNS). During neuro- and gliogenesis, nestin is replaced by cell type-specific intermediate filaments, e.g. neurofilaments and glial fibrillary acidic protein (GFAP). In this study, we demonstrate that nestin expression is re-induced in reactive astrocytes in the lesioned adult brain. Following ischaemic and mechanical lesioning, a strong and sustained expression of nestin was noted in GFAP-positive cells surrounding the lesion site. Lesion experiments in transgenic mice carrying the lacZ gene under control of regulatory sequences from the nestin gene suggested that the upregulation of nestin in reactive astrocytes is mediated via the same sequences that control nestin expression during CNS development. These observations and recent data on the co-expression of glial and neuronal marker antigens in reactive astrocytes point to a close relationship between proliferating astrocytes and neuroepithelial precursor cells.     

A longitudinal study of markers of bone turnover in Graves'' disease and their value in predicting bone mineral density

Alterations of chromosome 8, including deletions of 8p, occur frequently in many tumors. In this study, fluorescence in situ hybridization was used to study the relationship between 8p deletions, 8q gains, and phenotype in bladder cancer. Cells from 87 tumors were examined by dual-labeling fluorescence in situ hybridization with a centromere 8 probe (pJM12) and P1 probes for 8p22, 8p12, 8q12, and 8q24. Both 8p22 deletions and 8q24 gains were strongly associated with tumor phenotype. There was a marked difference in 8p22 deletions between noninvasive (pTa) tumors (3/33) and minimally invasive (pT1) tumors (8/19; P = 0.005) whereas there was no significant difference between pT1 and muscle-invasive (pT2-4) tumors (19/35; P = 0.3926). Six tumors with 8p22 deletion were examined at 8p12. Three of these tumors showed no 8p12 deletion, narrowing down the site of a putative tumor suppressor gene distal to 8p12. In one other case, there was a marked increase in 8p12 copy number (> 40 per cell; amplification), suggesting the presence of an oncogene involved in bladder cancer at 8p12. The marked difference in 8p22 deletions between noninvasive (pTa) and minimally invasive (pT1) tumors is consistent with a role of a putative tumor suppressor gene on 8p for development of invasive tumor phenotype.     

Pulmonary embolism: prospective comparison of spiral CT with ventilation-perfusion scintigraphy

PURPOSE: To compare prospectively the accuracy of spiral computed tomography (CT) with that of ventilation-perfusion scintigraphy for diagnosing pulmonary embolism. MATERIALS AND METHODS: Within 48 hours of presentation, 142 patients suspected of having pulmonary embolism underwent spiral CT, scintigraphy, and (when indicated) pulmonary angiography. Pulmonary angiography was attempted if interpretations of spiral CT scans and of scintigrams were discordant or indeterminate and intermediate-probability, respectively. RESULTS: In the 139 patients who completed the study, interpretations of spiral CT scans and of scintigrams were concordant in 103 patients (29 with embolism, 74 without). In 20 patients, intermediate-probability scintigrams were interpreted (six with embolism at angiography, 14 without); diagnosis with spiral CT was correct in 16. Interpretations of spiral CT scans and those of scintigrams were discordant in 12 cases; diagnosis with spiral CT was correct in 11 cases and that with scintigraphy was correct in one. Spiral CT and scintigraphic scans of four patients with embolism did not show embolism. Sensitivities, specificities, and kappa values with spiral CT and scintigraphy were 87%, 95%, and 0.85 and 65%, 94%, and 0.61, respectively. CONCLUSION: In cases of pulmonary embolism, sensitivity of spiral CT is greater than that of scintigraphy. Interobserver agreement is better with spiral CT.     

Clinical determinants of mortality in patients with angiographically diagnosed ischemic or nonischemic cardiomyopathy

OBJECTIVES: We sought to characterize the clinical determinants of mortality in patients with angiographically diagnosed ischemic or nonischemic cardiomyopathy. BACKGROUND: Patients with ischemic cardiomyopathy may have a worse prognosis than patients with nonischemic cardiomyopathy. Few studies have assessed the effect of ischemic versus nonischemic etiology on outcomes. METHODS: We analyzed prospectively collected data on 3,787 patients with a left ventricular ejection fraction < or = 40% who underwent coronary angiography. Patients were considered to have ischemic cardiomyopathy (n = 3,112) if they had a history of myocardial infarction, percutaneous transluminal coronary angioplasty, coronary artery bypass graft surgery or at least one major epicardial coronary artery with > or = 75% stenosis; all others were considered to have nonischemic cardiomyopathy (n = 675). RESULTS: The median age, ejection fraction and proportion of patients with New York Heart Association functional class III or IV symptoms for the nonischemic and ischemic groups were 55 years versus 63 years, 27% versus 32% and 57% versus 25%, respectively. After adjustment for baseline clinical risk factors and presenting characteristics, ischemic etiology remained an important independent predictor of 5-year mortality (p < 0.0001). The extent of coronary artery disease was a better predictor of survival than ischemic or nonischemic etiology (log likelihood chi-square 700 vs. 675, respectively). CONCLUSIONS: Ischemic etiology is a significant independent predictor of mortality in patients with cardiomyopathy. However, the extent of coronary artery disease contributes more prognostic information than the clinical diagnosis of ischemic or nonischemic cardiomyopathy. Further research is needed to refine the clinical definition of ischemic cardiomyopathy so that physicians can appropriately prescribe treatment and accurately predict outcome.     

Partial splenic embolization for treatment of disseminated intravascular coagulation in lymphangiomatosis

A 1-year-old boy presented with pericardial effusion, pulmonary infiltrates, and disseminated intravascular coagulation; lung biopsy indicated pulmonary lymphangiomatosis. He did not respond to medical therapy and was a poor surgical candidate; therefore, he underwent partial splenic embolization. The procedure resulted in a complete disappearance of the DIC and marked improvement in his cardiorespiratory status. He continues to thrive and is transfusion-independent 2 years after the procedure.