Added value of automated clinical proton MR spectroscopy of the brain.

Objective: A trial was conducted to establish the added diagnostic value of an automated proton MR spectroscopy (MRS) examination (PROBE).

Materials And Methods: The PROBE and MRS were compared for metabolite ratios of normal controls and 21 patients. In addition, PROBE was performed in either the occipital cortex (gray matter) or the parietal cortex (white matter) or, more rarely, within the confines of a focal lesion identified on MRI, using a GE Signa 1.

MR mammographic localization. Work in progress.

The authors present phantom test results for a stereotaxic device that may permit simple, rapid, and accurate needle biopsy and localization of breast lesions detected at contrast material-enhanced magnetic resonance (MR) mammography. The mechanical accuracy of this prototype MR breast localizer is approximately plus or minus 3.5 mm at 5 cm.

Electric field-induced redistribution and postfield relaxation of epidermal growth factor receptors on A431 cells.

The lateral mobility of the epidermal growth factor (EGF) receptor in the plane of the plasma membrane of cultured A431 cells was investigated using direct and indirect fluorescent probes to measure the generation and relaxation of electric field-induced receptor asymmetry. A steady electric field of 15 V/cm for 30 min at 23 degrees C induced a redistribution of the unoccupied EGF receptor such that there was approximately a three-fold higher concentration of receptors at the cathode-facing pole. After termination of the field, the unoccupied receptors back diffused at 37 degrees C with a rate corresponding to a diffusion coefficient of 2.

Synthesis of novel calcium-dependent proteins associated with mammary epithelial cell migration and differentiation.

A class of proteins from mouse mammary epithelial cells has been isolated which, like the calcium-binding protein calmodulin (CaM), binds to phenothiazine in a calcium-dependent manner. These proteins do not bind to phenothiazine through binding to CaM; we infer that they are calcium-binding proteins, and that they may be related to the similarly isolated 'calcimedins' of Moore, P D & Dedman, J, J biol chem 257 (1982) 9663 [8]. In primary cultures of mouse mammary cells on collagen gels, synthesis of certain of these proteins is associated with the spreading of cells to form monolayers; failure of cells to spread and differentiate, through omission of serum from culture medium, results in the inhibition of calcium-binding protein synthesis, with the exception of CaM and a 15 kD species.