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Biomedical subjects

C L Tyler

Publications and source records attributed to C L Tyler.

4 recordsLinked to original sources
PubMed2001

The effect of arbitration program characteristics on applicants' intentions toward potential employers.

The authors examined intentions toward prospective employers with different alternative dispute resolution (ADR) policies and no ADR policy. In Study 1, students (N = 124) were randomly assigned to 1 of 4 conditions in which 2 variables, arbitration policy presence or absence and firm desirability, were manipulated. The presence of a voluntary, nonbinding arbitration policy had no impact on intentions and did not interact with firm desirability. In Study 2, students (N = 273) were randomly assigned to 1 of 8 conditions (mandatory vs. voluntary arbitration, binding vs. nonbinding arbitration, and highly desirable vs. less desirable employer). Both mandatory and binding arbitration policies were related to less favorable intentions toward firms. Predictions regarding the interaction of ADR policy and firm desirability were partially supported. Some support was found for the interaction between ADR policy and ethnicity.

Adult↗
PubMed1995

Tryptase, the dominant secretory granular protein in human mast cells, is a potent mitogen for cultured dog tracheal smooth muscle cells.

Hyperplasia of airway smooth muscle cells is present in the airways of asthmatic patients and may contribute to the development of the bronchial hyperresponsiveness that occurs in these patients. Because tryptase is an abundant component of mast cell granules and has demonstrated growth-stimulatory effects in other mesenchymal cells (J. Clin. Invest. 1991; 88:493-499), the goal of our study was to determine whether tryptase is a mitogen for airway smooth muscle cells. The mitogenic effects of tryptase were tested in passages 1 through 5 of dog tracheal smooth muscle cells, either by counting smooth muscle cells or by monitoring uptake of bromodeoxyuridine (BrdU) into cellular DNA during S-phase. With respect to its efficacy, at a near maximal concentration (4 nM), tryptase increased cell numbers 2.1 +/- 0.2- or 2.8 +/- 0.6-fold above controls after 2 or 4 days, respectively, and these increases were approximately the same as those induced by platelet-derived growth factor (50 ng/ml) or 10% calf serum. With respect to potency, tryptase caused concentration-dependent increases in BrdU uptake, as detected in an enzyme-linked immunosorbent assay or by counting BrdU-labeled nuclei, with an EC50 of 2 nM. Pretreatment of tryptase with diisopropylfluorophosphate, to reduce markedly its catalytic as a activity as a proteinase, attenuated its growth-stimulated effects by 58 +/- 16%. Tryptase-induced mitogenesis was not a nonspecific effect of all serine proteinases, because thrombin, another proteinase with mitogenicity for fibroblasts, stimulated neither increases in cell counts nor BrdU uptake in our cells. We conclude that tryptase is a potent mitogen for airway smooth muscle cells in culture.

Animals↗
PubMed1991

Interferon-gamma activates rat alveolar macrophages for anticryptococcal activity.

Cryptococcus neoformans is a pathogenic yeast causing disease predominantly in immunosuppressed patients. C. neoformans is acquired by the pulmonary route, where the alveolar macrophage (AM) is a resident mechanism of host defense. The ability of rat AM to be activated by products of the immune response for enhanced anticryptococcal effect has not previously been demonstrated. Rat AM could be activated in vitro for anticryptococcal activity by medium conditioned by concanavalin A-stimulated splenic lymphocytes. A monoclonal antibody that neutralizes interferon-gamma (IFN-gamma) inhibited the macrophage-activating activity of lymphokine-containing medium (LCM). Further, recombinant IFN-gamma activated AM for anticryptococcal activity. The concentration of IFN-gamma in LCM, determined by enzyme-linked immunosorbent assay, was equivalent to the range of concentrations of recombinant IFN-gamma which activated AM. Thus, IFN-gamma was necessary and sufficient for optimal macrophage activation by medium conditioned by proliferating lymphocytes. Lipopolysaccharide could not enhance the anticryptococcal activity produced by optimal concentrations of LCM or IFN-gamma but did augment the effects of submaximal stimulation. Both LCM and recombinant IFN-gamma increased the percentage of macrophages with cell-associated cryptococcus, suggesting that activation of AM enhanced the adhesion or uptake of cryptococcus. We speculate that inadequate availability of lymphokines such as IFN-gamma may result in the immunodeficient state in hosts unable to generate an appropriate response to cryptococcal antigens. Administration of lymphokines such as IFN-gamma to immunosuppressed hosts might circumvent the defect in cell-mediated immunity.

Adjuvants, Immunologic↗