A photoreactive fluorescent marker for identifying eosinophils and their cytoplasmic granules in tissues.

Here we describe a simple histochemical technique that provides an improved approach to identifying eosinophil components in tissues through the formation of photoreactive complexes that produce stable fluorescent emissions. This method worked readily with histological tissue sections 6-60 microm thick, which were fixed in neutral buffered formalin (NBF), and with cell suspensions similarly fixed and unfixed. Deep red (>605 nm) fluorescent emissions were produced by eosinophil-specific granules when exposed to broadband excitation spectra from a 100-W mercury lamp source (510-590 nm), as well as single-wavelength excitations from both an argon laser (488 nm) and a UV-visible laser (514 nm).

Changes in the morphology and the distribution of rat intestinal eosinophils during infection with the nematode Nippostrongylus brasiliensis.

Increases in the numbers of eosinophil leukocytes present in the lamina propria of intestines infected with nematodes is a well described phenomenon, yet the role of these leukocytes and their actions in this situation are not yet fully understood. Morphologic changes in these cells occur with the course of the infection, as do alterations in their location within the gut; these findings may give important clues to the function of this prominent cell. We observed changes in intestinal eosinophils in the August rat during infection with the nematode Nippostrongylus brasiliensis and found, together with the well known increases in number infiltrating the lamina propria at Day 20 (three times the levels in normal animals), a distinct change in the morphology of individual cells which included increase of the cell's overall size and changes in shape, as well as a dissemination of cytoplasmic granules in relationship to the cell's nucleus.

An ultrastructural evaluation of acute 1-nitronaphthalene induced hepatic and pulmonary toxicity in the rat.

1-Nitronaphthalene is a mutagenic particulate of diesel exhaust which causes acute liver and lung toxicity in rodents. The studies presented here describe morphological changes in the lung and liver at several time intervals following a single injection of 1-nitronaphthalene (100 mg/kg, i.p.

Leukotriene C(4) biosynthesis in isolated August rat peritoneal leukocytes.

The mixed leukocyte population obtained from the peritoneum of the August rat is a potentially important experimental model of inherent eosinophilia that has not been well characterized. In the present study, isolated cell preparations generated a concentration-dependent release of leukotriene (LT) C(4) when exposed to the Ca(2+) ionophore A23187, reaching maximal stimulation at 5.0 muM.

Multiple anti-cytokine activities secreted from tanapox virus-infected cells.

Tanapox virus (TPV) produces a mild disease in humans characterized by transient fever, one or more nodular skin lesions and regional lymphadenopathy. We demonstrate that TPV-infected cells, but not mock-infected cells, secrete an early 38 kDa glycopeptide that, unlike any other known protein, binds to human (h) interferon-gamma, hIL-2 and hIL-5. In concomitant experiments this polypeptide failed to bind to hIL-1 alpha, hIL-3, hIL-4, hIL-6, hIL-7, hIL-8 or hIL-10.