Cultured cell lines and xenografts derived from 7 human medulloblastomas were evaluated for amplification of the c-myc, N-m>'c, epidermal growth factor receptor, and gli genes by Southern blot analysis. Karyotypes of the original biopsies and early passaged cells demonstrated double minute chromosomes in 4 of the 7 cases. All 7 samples (3 cell lines and 4 xenografts) from the 4 tumors with doub...

A gametocidal chromosome, chromosome 2C derived from Aegilops cylindrica, was introduced into six wheat-barley addition lines to establish chromosome-mutationinducing lines. These lines, except the one for chromosome 4H, had a pair of respective barley chromosomes and one 2C chromosome (22”+1’); the line for 4H was doubly monosomic for chromosome 4H and chromosome 2C (21”+2’). In these lines, c...

The term retinal dysplasia has been em­ ployed with two connotations in the ophthal­ mic literature. Its early usewas the more general, referring to abnormalities in the histogenesis of the developing retina. The term was used more restrictively by Reese and Blodi and Reese and Straatsma to desig­ nate a specific syndrome consisting of multi­ ple congenital anomalies, including bilateral ocular...

Foreign or native proteins which have passed through the glomerulus are reabsorbed by the cells in the middle portion of the convoluted tubule where they are concentrated as visible droplets. Oliver, MacDowell, and Lee (1) were the first to make extensive studies on the nature of these absorption droplets. Using supravital staining with dilute Janus green these authors showed that the protein d...

The DNA-stain content of human metaphase chromo.. somes is measured by use of quantitative cytochemistry, scanning cytophotometry, and image-processing techniques. This approach is applied to chromosomes from a female with chronic myelogenous leukemia. Measurements are normalized for each cell and expressed on a scale by which the sum of the measurements for the 44 autosomal chromosomes is 100 ...

The endocytosis and intracellular distribution of carcinogenic crystalline nickel sulfide (NiS) particles in Chinese hamster ovary cells were studied using time-lapse video recording with phase-contrast and bright-field optics. Crystalline NiS particles were phagocytosed by Chinese hamster ovary cells in regions of membrane ruffling. While these particles may remain bound to the cell surface fo...