Intracellular pattern of cytosolic Ca2+ changes during adhesion and multiple phagocytosis in human neutrophils. Dynamics of intracellular Ca2+ stores

The subcellular pattern of cytosolic free Ca2+ ([Ca2+]i) changes in human polymorphonuclear neutrophils (PMNs) was studied using imaging of fura-2 fluorescence (time resolution 12.5 ratios/s) to determine whether PMNs could obtain directional information from the [Ca2+]i signal. [Ca2+]i changes were observed during initial adherence, the subsequent chemotactic movement, and the phagocytosis of opsonized yeast particles. Initial adherence was followed by a rapid increase in [Ca2+]i (from 90 +/- 10 to 290 +/- 40 nmol/L in 6.5 +/- 2.5 seconds; +/- SEM, n = 10), apparently homogeneously distributed over the entire cytoplasm, which preceded the spreading of the PMNs. [Ca2+]i increases after the contact of the PMNs with yeast particles were of lower mean amplitude; [Ca2+]i increased simultaneously throughout the cytosol. In the absence of extracellular Ca2+, multiple phagocytotic events could proceed normally without a mandatory [Ca2+]i transient. In PMNs polarized on phagocytosis, gradients in [Ca2+]i could be observed. [Ca2+]i was more elevated in the periphagosomal area than in the remaining parts. Taken together, these data show that [Ca2+]i waves do not provide the neutrophil with directional information during chemotaxis and phagocytosis. Sustained small inhomogeneity of [Ca2+]i levels are consistent with a proposed redistribution of releasable Ca2+ stores on phagocytosis.     

Interleukin-6 and granulocyte-macrophage colony-stimulating factor are candidate growth factors for chronic myelomonocytic leukemia cells

Previous studies suggest that malignant cells from some patients with myeloid leukemias produce colony-stimulating factors (CSFs) that can function as autocrine growth factors in vitro. We have examined the roles of interleukin-6 (IL-6) and granulocyte-macrophage CSF (GM-CSF) in the proliferation of myeloid leukemia cells. IL-6 activity was assessed in conditioned medium (CM) from myeloid leukemia cell cultures or cell lysates using IL-6-dependent KD83 and 7TD1 murine cell lines. Media conditioned by cells from patients with chronic myelomonocytic leukemia (CMMoL), but not by normal monocytes, chronic myelogenous leukemia (CML), or acute myelogenous leukemia (AML) cells, contained substantial levels (50 to 1,000 U/10(6) cells) of IL-6. The IL-6 content of CM correlated directly with donor peripheral blood WBC count. CM from two of five CMMoL samples also contained greater than 350 pg/mL GM-CSF. Moreover, CMMoL cells spontaneously formed colonies in semisolid medium. CMMoL colony formation could be partially inhibited by antibodies to IL-6 or GM-CSF, whereas combination of these antibodies gave additive, and nearly complete (greater than 93%), inhibition of spontaneous colony formation. Cell lysates from uncultured CMMoL cells from one patient contained abundant GM-CSF protein but no detectable IL-6. These data suggest that IL-6 and GM-CSF act in vitro as autocrine growth factors for CMMoL cells, and that CMMoL cells in vivo may represent a GM-CSF-dependent autocrine growth system.     

P20 Red tattoo reactions

Tattoos are becoming increasingly popular, although reactions to tattoos remain relatively uncommon. We describe 4 patients with a variety of red tattoo reactions, one responding well to intralesional steroid therapy. Case 1: A 50‐year‐old man presented with a florid, inflammatory reaction confined to the red area of his forearm tattoo. Biopsy showed a dense lymphocytic and focal macrophage response to tattoo pigment. Mass spectrometry of biopsy tissue revealed high concentrations of titanium and iron. Patch testing was negative. Intralesional steroid injection has produced a marked improvement. Case 2: A 42‐year‐old man presented with an inflammatory reaction affecting the red area of his leg tattoo. Biopsy revealed a florid lymphoid reaction. Case 3: A 30‐year‐old man presented with an eczematous reaction within the red/brown pigmented areas of his tattoos, which was exacerbated by sun exposure. Patch testing showed a (+) positive reaction to cadmium after 96 hours. Photo patch testing was negative. The reaction settled spontaneously within 12 months. Case 4: A 37‐year‐old woman presented with a florid, indurated inflammatory reaction involving the red area of a shoulder tattoo. Patch testing revealed a (++) and (+) positive reaction to nickel and cobalt respectively with a doubtful (?+) reaction to mercury 0.5% in petrolatum after 96 hours. Tattoo reactions, especially red tattoo reactions can present with a spectrum of histological changes, including lichenoid, granulomatous, hypersensitivity, nodular, pseudolymphomatous or sarcoidal reactions. One of our cases responded well to intralesional steroid injection and one case resolved spontaneously.     

Specific gonadotrophin-releasing hormone analogue binding predominantly in human luteinized follicular aspirates and not in human pre-ovulatory follicles

In an attempt to resolve the apparent controversy in the observed effects of gonadotrophin-releasing hormone (GnRH) analogues on the ovary, conventional binding studies were conducted with a GnRH agonist and an antagonist in various ovarian tissues to demonstrate possible GnRH receptor binding. In human luteinized granulosa cells derived from unstimulated in-vitro fertilization cycles, high affinity receptor binding was present in 17 out of 24 patients, while binding was not observed in any of the six pre-ovulatory follicles removed during abdominal surgery. Apparently contradictory observations on the direct ovarian effects of GnRH analogues may be the result of the intermittent presence of high affinity GnRH receptors. Our observations indicate that in the human, high affinity ovarian GnRH receptors are present predominantly in ovarian tissue after the luteinizing hormone surge. We also propose the possibility of regulation and activation of a human follicular GnRH receptor in the ovary as a physiological process which may be influenced pharmacologically.