Two new monoclonal antibodies to human monocytes and granulocytes: isolation of membrane antigens and lack of effects of antibodies on leukocyte functions in vitro

Mice were immunized with purified human monocytes or granulocytes obtained by leukapheresis and isolated on dextran gradients or by countercurrent centrifugation-elutriation. A monoclonal antibody, Mo95, was generated in response to monocytes and was found to react strongly with monocytes, large granular lymphocytes (LGL), granulocytes, eosinophils, and some myelomonocytic leukemia cells, but not with normal T or B lymphocytes, platelets, red cells, or leukemic cell lines. Mo95 is an IgG1 antibody, which precipitated a 95 kD molecular weight antigen. Addition of the Mo95 antibody to monocytes in the absence of complement did not inhibit lysozyme secretion nor did it affect superoxide production, C3b-rosetting, nitrotetrazolium blue reduction, phagocytosis, or chemotactic responses. A second antibody, PMN70, was found to react exclusively with granulocytes and not with monocytes, lymphocytes, LGL, platelets, red cells, or any of the myelomonocytic, T-cell-derived or B-cell-derived leukemic cell lines tested. The PMN70 antibody immunoprecipitated a 70 kD molecular weight antigen found only on mature granulocytes. Mo95 and PMN70 appear to be distinct from five other tested monoclonal antibodies reactive to monocytes and/or granulocytes on the basis of the fluorescent cell sorter and immunoprecipitation studies performed.     

Burn support for Operation Iraqi Freedom and related operations, 2003 to 2004

Thermal injury historically constitutes approximately 5% to 20% of conventional warfare casualties. This article reviews medical planning for burn care during war in Iraq and experience with burns during the war at the US Army Burn Center; aboard the USNS Comfort hospital ship; and at Combat Support Hospitals in Iraq and in Afghanistan. Two burn surgeons were deployed to the military hospital in Landstuhl, Germany, and to the Gulf Region to assist with triage and patient care. During March 2003 to May 2004, 109 burn casualties from the war have been hospitalized at the US Army Burn Center in San Antonio, Texas, and US Army Burn Flight Teams have moved 51 critically ill burn casualties to the Burn Center. Ten Iraqi burn patients underwent surgery and were hospitalized for up to 1 month aboard the Comfort, including six with massive wounds. Eighty-six burn casualties were hospitalized at the 28th Combat Support Hospital for up to 53 days. This experience highlights the importance of anticipating the burn care needs of both combatants and the local civilian population during war.     

Piecemeal degranulation of mast cells in the inflammatory eyelid lesions of interleukin-4 transgenic mice. Evidence of mast cell histamine release in vivo by diamine oxidase-gold enzyme-affinity ultrastructural cytochemistry

We used light and electron microscopy to analyze the eyelid inflammation that develops in transgenic mice that overexpress interleukin-4 (IL-4; Tepper et al, Cell 62:457, 1990). Analysis of alkaline Giemsa-stained plastic sections examined by light microscopy (Dvorak et al, J Exp Med 132:558, 1970), as well as by routine transmission electron microscopy, indicated that the mast cells in the inflammatory eyelid lesions were undergoing piecemeal degranulation, a form of secretion in which the cells' cytoplasmic granules exhibit characteristic morphologic changes that are thought to be associated with the prolonged, vesicle-mediated release of the granules' constituents. Moreover, by using a newly reported enzyme affinity-gold method, which stains histamine based on binding to diamine oxidase-gold (Dvorak et al, J Histochem Cytochem 41:787, 1993), we show that these activated mast cells had released much of their histamine content. The eyelid lesions also exhibited increased numbers of mast cells; interstitial fibrosis, particularly around cutaneous nerves and blood vessels; activated fibroblasts; focal axonal damage; venules with endothelial cells containing numerous vesiculo-vacuolar organelles; and infiltrates of neutrophils and eosinophils. Our findings illustrate that overexpression of the IL-4 gene in vivo can result in eyelid lesions associated with piecemeal degranulation of mast cells, as well as tissue fibrosis and a variety of other pathologic changes. These results also represent the first direct morphologic evidence for histamine secretion by mast cells in vivo.     

Opiate antagonistic properties of an octapeptide somatostatin analog.

The somatostatin analog D-Phe-Cys-Phe-D-Trp-Lys-Thr-Cys-NH-CH(CH2OH)CHOHCH3 (SMS 201-995) displaces [3h[naloxone from its binding sites (IC50, 38 +/- 60 nM), being more than 200 times more potent than somatostatin. As measured by the difference between [3H]dihydromorphine, [3H][D-Ala2,D-Leu5]enkephalin, and (-)-[3H]bremazocine binding, SMS 201-995 appears to be highly specific for the opiate mu binding site. Electrophysiological data from hippocampal cultures and results from animal studies (tail flick, mydriasis) demonstrate the opiate antagonistic properties of SMS 201-995. SMS 201-995 is an opiate mu antagonist with a peptide structure. That this property is displayed by a somatostatin analog is somewhat unexpected.     

Activation of the CPP32 protease in apoptosis induced by 1-beta-D- arabinofuranosylcytosine and other DNA-damaging agents

The response of human myeloid leukemia cells to treatment with 1-beta- arabinofuranosylcytosine (ara-C) includes the induction of apoptosis. Ara-C induced apoptosis is associated with proteolytic cleavage of poly(ADP-ribose) polymerase (PARP) and protein kinase C (PKC) delta. However, the signals involved in this response are unknown. The present studies show that ara-C treatment of U-937 cells is associated with induction of a protease activity that cleaves the tetrapeptides Ac-DEVD- pNA and Ac-DMOD-pNA found at the cleavage sites of PARP and PKC delta, respectively. The ara-C-induced protease activity was sensitive to overexpression of the anti-apoptotic protein Bcl-xL and the baculovirus protein p35. By contrast, overexpression of the cowpox virus protein CrmA blocked apoptosis induced by engagement of the Fas receptor but not that induced by ara-C. CrmA overexpression also had no detectable effect on ara-C-induced cleavage of PKC delta. The results further show that ara-C induces activation of the CPP32 protease by a CrmA- insensitive and p35-sensitive mechanism. Similar results were obtained with cisplatinum, etoposide, and camptothecin. These findings indicate that ara-C and other DNA-damaging agents activate a CrmA-insensitive apoptotic pathway involving CPP32 and that these signals differ from those associated with apoptosis induced by the Fas receptor.