3,224 research outputs found
Testing the DoseāResponse Specification in Epidemiology: Public Health and Policy Consequences for Lead
Statistical evaluation of the doseāresponse function in lead epidemiology is rarely attempted. Economic evaluation of health benefits of lead reduction usually assumes a linear doseāresponse function, regardless of the outcome measure used. We reanalyzed a previously published study, an international pooled data set combining data from seven prospective lead studies examining contemporaneous blood lead effect on IQ (intelligence quotient) of 7-year-old children (n = 1,333). We constructed alternative linear multiple regression models with linear blood lead terms (linearālinear dose response) and natural-logātransformed blood lead terms (log-linear dose response). We tested the two lead specifications for nonlinearity in the models, compared the two lead specifications for significantly better fit to the data, and examined the effects of possible residual confounding on the functional form of the doseāresponse relationship. We found that a log-linear leadāIQ relationship was a significantly better fit than was a linearālinear relationship for IQ (p = 0.009), with little evidence of residual confounding of included model variables. We substituted the log-linear leadāIQ effect in a previously published health benefits model and found that the economic savings due to U.S. population lead decrease between 1976 and 1999 (from 17.1 Ī¼g/dL to 2.0 Ī¼g/dL) was 2.2 times (149 billion). The Centers for Disease Control and Prevention action limit of 10 Ī¼g/dL for children fails to protect against most damage and economic cost attributable to lead exposure
Pseudomyogenic Hemangioendothelioma of Bone Initially Managed as Slipped Capital Femoral Epiphysis: A Case Report
Pseudomyogenic hemangioendothelioma is a rare, recently described neoplasm that usually presents as multifocal lesions in a single extremity. The disease has demonstrated a high propensity for infiltrative growth and local recurrence but limited metastatic potential. Variations of histological appearance and immunohistochemical signatures have been described, but typically involve spindle or polygonal cells with nuclear atypia and neutrophilic infiltration. Here we present\ud
a case report of an 8-year-old female who presented with hip pain that was initially diagnosed and managed as a slipped capital femoral epiphysis (SCFE). Subsequent evaluation led to the diagnosis of pseudomyogenic hemangioendothelioma of bone. Due to the degree of osseous destruction, described patterns of local recurrence, and metastatic potential of this neoplasm, a wide resection with endoprosthetic reconstruction of the proximal femur was performed. This case highlights the\ud
importance of due diligence in the diagnoses of SCFE and bone tumors in young patients with abnormalities of the proximal femur, including consideration of the need for biopsy
Covalent structured catalytic materials containing single-atom metal sites with controllable spatial and chemical properties: concept and application
Metastatic Rectal Adenocarcinoma of the Hip and Knee Joints: A Case Series
Two cases are presented of patients with a history of metastatic rectal adenocarcinoma presenting with a painful joint effusion. Both cases are potential examples of metastasis to periarticular bone with local infiltration to the synovium, which is one proposed mechanism of intrasynovial metastasis. While skeletal metastases are a relatively common occurrence in metastatic adenocarcinoma, intraarticular metastasis is extremely rare. These cases highlight the need to consider metastasis in the differential of joint swelling in the setting of a history of adenocarcinoma
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