RESUMO
Granulomas are the interface between host and mycobacteria, and are crucial for the surivival of both species. While macrophages are the main cellular component of these lesions, different lymphocyte subpopulations within the lesions also play important roles. Lymphocytes are continuously recruited into these inflammatory lesions via local vessels to replace cells that are either dying or leaving; however, their rate of replacement is not known. Using a model of granuloma transplantation and fluorescently labeled cellular compartments we report that, depending on the subpopulation, 10-80%, of cells in the granuloma are replaced within one week after transplantation. CD4(+) T cells specific for Mycobacterium antigen entered transplanted granulomas at a higher frequency than Foxp3(+) CD4(+) T cells by one week. Interestingly, a small number of T lymphocytes migrated out of the granuloma to secondary lymphoid organs. The mechanisms that define the differences in recruitment and efflux behind each subpopulation requires further studies. Ultimately, a better understanding of lymphoid traffic may provide new ways to modulate, regulate, and treat granulomatous diseases.
RESUMO
We describe an evaluation of the in-use stability and short-term precision of a three-level ampuled quality-control system for monitoring pH, pCO2, and pO2 measurements on clinical blood-gas analyzers. In three hospital laboratories, 324 such ampuls were opened and allowed to stand with their contents exposed to atmospheric conditions for accurately timed intervals up to 240 s. Contents were then analyzed for pH, pCO2, and pO2. Student's t-test was used to evaluate the significance of differences observed in recoveries after time exposure. At a signifcance level of P less than or equal to 0.05, the only significant changes observed throughout the first minute of exposure were average pO2 increases of 180 Pa (1.4 mmHg) (+ 1.4%) and 230 Pa (1.7 mmHg) (+ 2.9%) at levels of 13.4 and 7.7 kPa kPa (101 and 58 mmHg), respectively. The ampuled system was found to be stable precise convenient, and suitable for use in the routine laboratory.
