Wilms tumor: ultrasonic features, pathologic correlation, and diagnostic pitfalls

The gray-scale ultrasonic features of Wilms tumor are reported with pathologic comparison. The most consistent ultrasonic features are large size, sharp margination, and echogenic heterogeneity. The frequently observed anechoic areas correlated with hemorrhage and necrosis. A rare case of mesoblastic nephroma is included for comparison. Pitfalls in diagnosis are discussed.     

Neutrophil labeling with indium-111: tropolone vs. oxine

This study was undertaken to compare tropolone with oxine (8-hydroxy-quinoline) for labeling human neutrophils with In-111. Exposure of neutrophils to tropolone at concentrations required for efficient labeling resulted in a marked impairment of chemotaxis. In contrast, no impairment of neutrophil chemotaxis was observed using In-111 oxine. Labeling efficiencies obtained with In-111 tropolone under optimal conditions were consistently less than those obtained with In-111 oxine. We evaluated cells labeled by the two methods using chemotaxis radioassay to assess the chemotatic potential of labeled cells. The results led to the conclusion that the oxine technique is preferable to tropolone for labeling human neutrophils with In-111.     

Dystroglycan is essential for early embryonic development: disruption of Reichert's membrane in Dag1-null mice

Dystroglycan is a central component of the dystrophin-glycoprotein complex (DGC), a protein assembly that plays a critical role in a variety of muscular dystrophies. In order to better understand the function of dystroglycan in development and disease, we have generated a null allele of dystroglycan (Dag1neo2) in mice. Heterozygous Dag1neo2 mice are viable and fertile. In contrast, homozygous Dag1neo2 embryos exhibit gross developmental abnormalities beginning around 6.5 days of gestation. Analysis of the mutant phenotype indicates that an early defect in the development of homozygous Dag1neo2 embryos is a disruption of Reichert's membrane, an extra-embryonic basement membrane. Consistent with the functional defects observed in Reichert's membrane, dystroglycan protein is localized in apposition to this structure in normal egg cylinder stage embryos. We also show that the localization of two critical structural elements of Reichert's membrane- -laminin and collagen IV--are specifically disrupted in the homozygous Dag1neo2 embryos. Taken together, the data indicate that dystroglycan is required for the development of Reichert's membrane. Furthermore, these results suggest that disruption of basement membrane organization might be a common feature of muscular dystrophies linked to the DGC.      

In vivo proton magnetic resonance spectroscopy of breast cancer: a review of the literature

An emerging clinical modality called proton magnetic resonance spectroscopy (1H-MRS) enables the non-invasive in vivo assessment of tissue metabolism and is demonstrating applications in improving the specificity of MR breast lesion diagnosis and monitoring tumour responsiveness to neoadjuvant chemotherapies. Variations in the concentration of choline-based cellular metabolites, detectable with 1H-MRS, have shown an association with malignant transformation of tissue in in vivo and in vitro studies. 1H-MRS exists as an adjunct to the current routine clinical breast MR examination. This review serves as an introduction to the field of breast 1H-MRS, discusses modern high-field strength and quantitative approaches and technical considerations, and reviews the literature with respect to the application of 1H-MRS for breast cancer.     

Relative oral efficacy and acute toxicity of hydroxypyridin-4-one iron chelators in mice [see comments]

The relationship between the oral efficacy and the acute toxicity of hydroxypyridin-4-one iron chelators has been investigated to clarify structure-function relationships of these compounds in vivo and to identify compounds with the maximum therapeutic safety margin. By comparing 59Fe excretion following oral or intraperitoneal administration of increasing doses of each chelator to iron-overloaded mice, the most effective compounds have been identified. These have partition coefficients (Kpart) above 0.3 in the iron-free form with a trend of increasing oral efficacy with increasing Kpart values (r = .6). However, this is achieved at a cost of increasing acute toxicity, as shown by a linear correlation between 59Fe excretion increase per unit dose and 1/LD50 (r = .83). A sharp increase in the LD50 values is observed for compounds with Kpart values above 1.0, suggesting that such compounds are unlikely to possess a sufficient therapeutic safety margin. Below a Kpart of 1.0, acute toxicity is relatively independent of lipid solubility. All the compounds are less toxic by the oral route than by the intraperitoneal route, although iron excretion is not significantly different by these two routes. At least five compounds (CP51, CP94, CP93, CP96, and CP21) are more effective orally than the same dose of intraperitoneal desferrioxamine (DFO) (P less than or equal to .02) or orally administered L1(CP20) (P less than or equal to .02).