Purification and molecular cloning of a novel group of BMPs and localization of BMP mRNA in developing bone

Using a novel purification scheme, we have characterized BMP as a 30kD fraction. After reduction, which destroys biological activity, this fraction was shown to be comprised of individual polypeptides with molecular weights of 30kD, 18kD and 16kD. Molecular cloning of these polypeptides resulted in the identification of 4 previously undescribed genes (BMP-1, BMP-2A, BMP-2B, and BMP-3) each of which is capable of directing de novo cartilage formation in vivo. While BMP-1 appears to be unrelated to other known growth factors, the derived amino acid sequence of BMP-2A, 2B, and 3 indicate that they are new members of the TGFb gene family. BMP-1, 2A and 2B are expressed in rat embryos during morphogenesis and can be localized by in situ hybridization to developing limb buds. BMP-3 localizes to neural ectoderm and later on in development to newly forming periosteum. Comparisons to other members of the TGFb family suggest that these newly identified BMPs are involved in pattern formation during early skeletal development.     

Benign extraaxial tumors: contrast enhancement with Gd-DTPA

Meningiomas, acoustic neuromas, and other benign extraaxial tumors have little contrast with adjacent brain tissue on conventional magnetic resonance (MR) images. The contrast enhancement produced by intravenous administration of 0.1 mmol/kg of gadolinium-DTPA in these tumors was measured on T1 MR images. Acoustic neuromas showed the greatest enhancement (average, 310%), meningiomas the next greatest (average, 180%), and neurofibromas, glomus tumors, and pituitary microadenomas the least enhancement. The degree of enhancement was almost always greater at 3 minutes than at 25 or 55 minutes. Contrast between the tumor and adjacent tissue resulted from tumor enhancement in neuromas, meningiomas, and neurofibromas and from enhancement of the surrounding tissue in pituitary microadenomas.     

New approaches to receiver operating characteristic methods in functional magnetic resonance imaging with real data using repeated trials.

Receiver operating characteristic (ROC) methods are useful tools for evaluating the sensitivity and specificity of various postprocessing algorithms used in fMRI data analysis. New ROC methods using real fMRI data are proposed that improve a previously introduced method by Le and Hu (Le and Hu, NMR Biomed 1997;10:160-164). The proposed methods provide more accurate means of estimating the true ROC curve from real data and thereby aid in the comparative evaluation of a wide range of postprocessing tools in fMRI. The mathematical relationships between different ROC curves are explored for a comparison of different ROC methods. Examples using real and simulated data are provided to illustrate the ideas involved.     

Cranial duplex sonography of the infant

Duplex sonography was used to evaluate the cranial contents of 75 infants. The first 35 were scanned to establish technique and evaluate basic flow patterns. All cranial vessels scanned in healthy term infants produced diphasic (low-resistance) waveforms, although certain cerebral vessels had characteristic Doppler signatures. The pericallosal, callosomarginal, anterior cerebral, basilar, middle cerebral, and internal carotid arteries and the vein of Galen were isolated and evaluated in almost every subject. In the second part of the study duplex characteristics of healthy term infants, healthy preterm infants, preterm infants with intracranial hemorrhages, and hydrocephalic infants were evaluated. Relative flow velocity at peak systole and end diastole and pulsatility index were investigated. The most significant variable was gestational age. Preterm infants frequently had no forward flow during diastole. Duplex sonography does not appear to add significant diagnostic information to routine real-time cranial studies. It does, however, permit more exact evaluation of cerebral blood flow than does non-pulse-gated, nondirected Doppler scanning.     

Intracranial calcification in the infant and neonate: evaluation by sonography and CT

This study reports the sonographic and computed tomography (CT) findings in seven infants and neonates with intracranial calcifications and a spectrum of underlying disorders, including toxoplasmosis, cytomegalic inclusion disease, transverse/straight sinus thrombosis, and probable anoxia. Neurotropic infectious disease usually produced clumped or subependymal calcifications accompanied by sometimes bizarre ventricular configurations and prominent periventricular cystic encephalomalacia. Sonography failed to identify prospectively intracranial calcifications in two of the three patients without infection, although calcifications were visible in retrospect. Overall, CT provided optimum visualization of intracranial calcifications.