Osteocalcin and osteonectin immunoreactivity in the diagnosis of osteosarcoma

Osteosarcomas (OSAs) can be difficult to distinguish histologically from tumors with significantly different biologic potentials and treatment protocols. The correct diagnosis of OSA relies on identification of malignant osteoblasts that are capable of producing neoplastic bone. To determine the use of immunohistochemistry for the diagnosis of OSA, 106 tumors from the Massachusetts General Hospital and the University of Vermont were immunostained with monoclonal antiosteocalcin (OC) and antiosteonectin (ON) antibodies. They included 42 OSAs, 25 non-bone-forming sarcomas, 24 other malignant tumors including lymphomas, carcinomas, and melanomas, and 15 benign bone tumors. Cytoplasmic staining with OC showed 70% sensitivity and 100% specificity, while staining with ON showed 90% sensitivity and 54% specificity for bone-forming tumors, consistently staining cell types other than osteoblasts. Of the OSAs, 83% demonstrated matrix staining with one or both antibodies, whereas dense collagen was negative for both antibodies in all tumors. We conclude that tumor cell cytoplasmic staining with monoclonal OC may be helpful in distinguishing OSAs from other malignancies, and staining of extracellular matrix for OC and ON antibodies concurrently may help distinguish bone matrix from dense collagen.     

Enhancing students' comprehension of the conceptual structure of algebra word problems.

Three experiments investigated Ss' ability to classify and solve similar algebra word problems. Four groups of problems were used, varying along 2 dimensions: problem equation type (2 types) and problem structure type (2 types). Ss were presented problem pairs and asked to rate the potential usefulness of Problem 1 in solving Problem 2. With no instruction, Ss rated problems sharing conceptual structure as being more helpful, regardless of equation type. Pairs with similar equations did not show this effect (Exp 1). This effect was enhanced by brief instruction, which illustrated structural similarities (Exp 2). Finally, a brief tutorial improved problem-solving performance (Exp 3). The improvement was particularly evident when target problems shared structural components but had different equations. The results are interpreted within S. K. Reed's (1987) structure-mapping model. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Prenatal and neonatal testosterone exposure interact to affect differentiation of sexual behavior and partner preference in female ferrets.

Implanting testosterone (T) subcutaneously over Postnatal Days 5–20 masculinized sexual behavior, reduced proceptive responsiveness, and shifted sexual preference more readily in male than in female ferrets gonadectomized on Day 5. This enhanced sensitivity of males to neonatal T was best duplicated in females exposed transplacentally to T over Embryonic Days (E) 27–39 (41-day gestation) and injected at birth with T (2.5 μg sc in oil:10% ethanol). Extended exposure of male ferrets to high levels of T, beginning shortly after the onset of testicular steroidogenesis (E25) and continuing for several hours after birth (E41) normally sensitizes their brains to the subsequent organizational effects on coital performance and sexual motivation of the relatively low levels of T that circulate in male ferrets during the first 3 postnatal weeks. (PsycINFO Database Record (c) 2010 APA, all rights reserved)