No abstract

Background: The human T-cell leukemia virus type 1 (HTLV-1) Tax protein indirectly influences transcriptional activation, signal transduction, cell cycle control, and apoptosis. The function of Tax primarily relies on protein-protein interactions. We have previously shown that Tax upregulates the cell cycle checkpoint proteins p21/waf1 and cyclin D2. Here we describe the consequences of upregulating these G 1 /S checkpoint regulators in HTLV-1 infected cells.

Adherence of salmonellae to the mucosa of the cecum was demonstrated using scanning electron microscopy. In the absence of other microflora, adherence was also shown at all other levels of the alimentary tract tested. Comparative development of native gut microflora in the ceca was also investigated in chicks treated with selected fecal microflora and in untreated chicks using scanning electron microscopy. In the treated chicks, there was early colonization by adherent bacteria interconnected with fibers, forming a mat of microflora. This mat of microflora may be responsible for preventing colonization of salmonellae in the ceca.

Powdered sugars are known to be fairIy cohesive mater-I Fine silicon oxide, sodium aluminum silcate, tricalcium phosphate and calcium stearate powders were admixed with dry ground sugar at four concentration levels between 0.1 to 2%. Appreciable increase in loose -bulk density and decrease in compressibility were notice able at 0.1% concentration in alI four agents. Theeffect reached an apparent peak'or a flat maximum at an agent concentration of about OS-l%. With the exception of silicon oxide treated powders, increase in density was-accompanied by a corresponding decrease in compressibility. Bulk parameters (i.e., density and compressibility) were more sensitive indices to changes occurring in powders as compared to parameters determined in compacted specimens (i.e., yield in shear, internal friction and relaxation pattern). Results are explained in terms of possible bed arrays and their scatter by differences in particle size and shape distributions. Support for these explanations is' presented in scanning electron micrographs of sugar treated and untreated particles.