The morphology of the tight junction of rat thyroid epithelium was examined in freeze-fractured material fixed in glutaraldehyde and briefly glycerinated. In normal thyroids the overall appearance of this junctional specialization resembled that of other cell types in many respects. Short-term changes in thyroid activity and hypophysectomy for 3 wk did not obviously affect the appearance of t...

The antiviral activity of oxidized spermine was compared with that of other aldehydes. Suspensions of vaccinia virus were incubated at 37 C with various concentrations of the aldehydes, and the infectivity of the viruses was determined by the plaque assay. Oxidized spermine at a concentration of 0.82 mM completely inactivated a suspension of vaccinia virus (1.4 x 10(8) plaque-forming units) aft...

The cell-to-cell binding induced by concanavalin A (Con A) and the lectins from wheatgerm, soybean, and waxbean has been analyzed by measuring the ability of single cells to bind to lectin-coated cells immobilized on nylon fibers. The cells used were lymphoma, myeloid leukemia, and normal fibroblast cells. With all lectins, cell-to-cell binding was inhibited if both cells were prefixed with glu...

Triclinic crystals of hen egg-white lysozyme cross-linked with glutaraldehyde have been treated with various denaturants and found to be susceptible to x-ray structure analysis even after major conformational changes in the protein. Cross-linked crystals were isomorphous with the native form, and electron density difference maps indicated the locations of intermolecular corss-links, but showed ...

The 24-hour delay between seeding coverslips with cells and inoculating samples for culture of chlamydiae was reduced to less than 1 hour by using coverslips which had been pre-treated with glutaraldehyde-activated gamma-aminopropyl-triethoxysilane. Treated coverslips were not toxic for McCoy cells and even one year after treatment monolayers formed rapidly on them. Furthermore, all of 13 Chlam...

This study demonstrates, by freeze fracture, clustering of intramembranous particles caused by cryoprotectant treatment of intact unfixed mouse lymphoid cells. Both T and B cells react in a similar fashion, while similar clustering of particles is not observed in some other cell types. The intramembranous particles can be aggregated by incubating unfixed cells in glycerol or dimethylsulfoxide (...

A method to measure DNA and chlorophyll fluorescence simultaneously in single phytoplankton cells was developed and tested on cultured and natural populations. Samples were stored at -80°C following fixation with 1 % glutaraldehyde and freezing in Ilquid nitrogen, stained with DAPI (4',6-&amino-2-phenylindole), and analyzed by flow cytonletry. In cultures, cell DAPI-DNA fluorescence measured by...

The purpose of this study was to evaluate the effectiveness of various chemical disinfectants in decontamination of gutta-percha (GP) cones contaminated with Bacillus subtilis spores. Sodium hypochlorite solution (4%), glutaraldehyde solution (2%), povidone-iodine solution (5%), and savlon solutions were compared for effectiveness in sterilizing gutta-percha cones contaminated with Bacillus sub...

To correlate viability with attachment capacity, Mycoplasma gallisepticum cell harvested at different growth phases and treated by various agents were tested for their capacity to attach to human erythrocytes. The results show that viability per se is not essential for M. gallisepticum attachment to erythrocytes, as cells killed by ultraviolet irradiation anmd membranes isolated by lysing M. ga...

Direct electron microscopic examination confirms that short actin filaments rapidly anneal end-to-end in vitro, leading over time to an increase in filament length at steady state. During annealing of mixtures of native unlabeled filaments and glutaraldehyde-fixed filaments labeled with myosin subfragment-1, the structural polarity within heteropolymers is conserved absolutely. Annealing does n...