Embryonic chick nerve cells, from dissociated dorsal root ganglia, were cultured on polylysine substrata and examined for tubulin and actin distribution by indirect immunofluorescence. Antibodies generated against chick brain tubulin produced specific fluorescence in growth cones, neurites, and cell bodies without revealing distribution differences or… (More)
Anticipatory postural activity in the trunk and legs precedes rapid shoulder flexion in unit gravity. We tested the hypothesis that anticipatory activity is a component of a single neural command for arm movement by monitoring the surface electromyographic activity of the biceps femoris, paraspinals and deltoid muscles of three subjects during the… (More)
Cultured, bone marrow-derived macrophages, murine spleen and lymph node cells, and human lymphocytes were tested for their ability to secrete cytokines in space. Lipopolysaccharide-activated bone marrow macrophages were found to secrete significantly more interleukin-1 and tumor necrosis factor when stimulated in space than when stimulated on earth. Murine… (More)
Based on the amino acid sequence of bovine rhodopsin, five peptides corresponding to the carboxyl terminus and one loop region have been synthesized. Rabbit antisera to these peptides recognize rhodopsin in whole bovine and dog retinas. Antisera were used to detect differences in specific regions of rhodopsin in dystrophic vs normal dog retinas. As detected… (More)
A radioimmunoassay has been developed for the quantitation of crytoplasmic tubulin. It measures tubulin between 20 and 1500 nanograms and does so independently of decay in colchicine-binding activity. In addition, the state of tubulin as subunit or polymer does not alter the measurement.
Changes in neuromuscular activation patterns associated with movements made in microgravity can contribute to muscular atrophy. Using EMG to monitor "postural" muscles, it was found that free floating arm flexions made in microgravity were not always preceded by neuromuscular activation patterns normally observed during movements made in unit gravity. … (More)
Dorsal root ganglia from 8-day chick embryos can be stimulated to extend nerve processes in culture by inclusion of cytosine arabinoside (Ara-C) in the culture medium, in the absence of exogenous nerve growth factor (NGF). The degree of stimulation is dose dependent, and is not mimicked by either free cytosine or free arabinose. Since Ara-C is known to… (More)