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Fourteen patients and five healthy individuals underwent magnetic resonance (MR) imaging to determine an effective multiple spin echo pulse sequence for estimating T2. Lesions examined included infarction, glioma, multiple sclerosis, and acute hematoma. A pulse repetition time (TR) of 1,500 msec and echo delays (TEs) of 25, 50, 75, and 100 msec were used. Computed T2 images were derived from all four echoes, the first two echoes, and the first and fourth echoes. T2 values were obtained from specific brain locales using region-of-interest analysis. Use of either the first two echoes or the first and fourth in the T2 fit provided T2 estimates which closely correlated with that of the four-echo analysis. The noise level in T2 maps constructed from the 25- and 100-msec echoes was modestly (typically 10%) higher than that from four echoes; noise level from the 25- and 50-msec echoes was markedly higher, typically 60%. This behavior is remarkably consistent with that predicted from theory. All 19 subjects displayed consistent relative T2 values for specific brain structures; in 13, the absolute T2 values fell within a limited range. Despite the high sensitivity of T2 images, their specificity in the detection of most brain disease appears limited except in acute intracerebral hematoma, which exhibited a decreased T2 relaxation time using high-field-strength MR imaging.  相似文献   
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OBJECTIVES: To identify community characteristics associated with children having elevated blood lead levels (> or = 10 micrograms/dL) and examine whether these characteristics can be used to identify children with elevated blood lead levels. PARTICIPANTS AND SETTING: A total of 20,296 children in Monroe County, New York (< 6 years old) who had blood lead testing in the first 12 months after statewide mandated reporting of blood lead tests began. DESIGN: A logistic regression analysis was conducted to examine the association of children's blood lead levels and community characteristics by using community characteristics of 653 census block groups. RESULTS: The following community level variables were associated with increased risk of elevated blood lead levels in children: residence within the city [odds ratio (OR), 2.0; 95% confidence interval (CI), 1.6, 2.7]; block groups with a higher proportion of individuals of Black race (OR, 1.6; CI, 1.4, 2.0); higher screening rate (OR, 1.9; CI, 1.6, 2.4); lower housing value (OR, 1.6; CI, 1.2, 2.0); housing built before 1950 (OR, 1.5; CI, 1.3, 1.8); higher population density (OR, 1.5; CI, 1.3, 1.8); higher rates of poverty (OR, 1.4; CI, 1.2, 1.8); lower percent of high school graduates (OR, 1.3; CI, 1.1, 1.6), and lower rates of owner-occupied housing (OR, 1.2; CI, 1.0, 1.4). Community characteristics were comparable with clinic-based individual risk assessment to identify children with elevated blood lead levels. CONCLUSIONS: These data demonstrate that community characteristics can be used to develop screening strategies to identify children who have elevated blood lead levels and shift our efforts toward identifying houses containing lead hazards before occupancy and before children are unduly exposed.  相似文献   
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Background  

Low and intermediate grade chondrosarcomas are relative rare bone tumours. About 5-12% of all chondrosarcomas are localized in base of skull region. Low grade chondrosarcoma has a low incidence of distant metastasis but is potentially lethal disease. Therefore, local therapy is of crucial importance in the treatment of skull base chondrosarcomas. Surgical resection is the primary treatment standard. Unfortunately the late diagnosis and diagnosis at the extensive stage are common due to the slow and asymptomatic growth of the lesions. Consequently, complete resection is hindered due to close proximity to critical and hence dose limiting organs such as optic nerves, chiasm and brainstem. Adjuvant or additional radiation therapy is very important for the improvement of local control rates in the primary treatment. Proton therapy is the gold standard in the treatment of skull base chondrosarcomas. However, high-LET (linear energy transfer) beams such as carbon ions theoretically offer advantages by enhanced biologic effectiveness in slow-growing tumours.  相似文献   
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The proinflammatory cytokine IL-18 mediates IFN-gamma production as well as the induction of Th1 polarized immune responses in synergy with IL-12. In this study, we describe the production of isogeneic monoclonal antibodies (Mabs) directed against murine IL-18 (mIL-18). Immunization of IL-18-deficient mice with recombinant mIL-18 in the presence of CpG-oligodeoxynucleotides (CpG-ODN) and alum as adjuvant resulted in high anti-IL-18 serum titers. We could identify two Mabs, SK721-2 and SK113AE-4, which were able to bind to IL-18 and neutralize its IFN-gamma inducing effect in vitro with an IC(50) of 40-100 ng/ml. In vivo, LPS-induced IFN-gamma production was reduced by 60-85% following a single administration of Mabs SK113AE-4 or SK721-2. Since IL-18 is likely to be involved in the pathogenesis of inflammatory diseases such as rheumatoid arthritis or Crohn's disease, neutralizing mouse anti-mouse IL-18 Mabs have the potential to become valuable tools for the therapeutic exploration of long-term IL-18 blockade in vivo.  相似文献   
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Nonunion of the distal femur is a rare injury that is difficult to manage. A variety of surgical implants and techniques are available. We present an alternative mode of treatment for supracondylar femoral nonunion using a custom retrograde titanium femoral nail (Biomet; Warsaw, IN) to successfully achieve union in two cases. We believe the added length, custom modifications, and enhanced stability allowed better fixation in an osteopenic distal femur.  相似文献   
100.
The widespread use of inhaled corticosteroids (ICS) since the early 1970's has meant that asthma is generally better controlled in comparison with previous decades. Nevertheless, recent patient interview surveys indicate that there is still a lot to gain in terms of abolishing daytime and nocturnal symptoms, and asthma exacerbations. It is important to use the terms asthma 'control' and asthma 'severity' in a correct way. Whereas asthma control reflects fluctuation in symptoms and lung function (or lack of them) over time, asthma severity reflects both asthma control and the need for medication. Thus, 'severity' is a property of the disease which reflects the degree of pathophysiological abnormality, whereas 'control' refers to the reduction of the clinical manifestations of disease achieved by treatment - thereby reflecting the adequacy of treatment. This introductory review, the first of a series of review papers to be published in this journal by the ADMIT team (see Appendix), discusses briefly our present knowledge of asthma control, its components, factors that may limit patients' ability to achieve optimal asthma control, and instruments to measure asthma control.  相似文献   
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