Granulocyte colony-stimulating factor administration to healthy volunteers: analysis of the immediate activating effects on circulating neutrophils

In four healthy volunteers, we analyzed in detail the immediate in vivo effects on circulating neutrophils of subcutaneous administration of 300 micrograms of granulocyte colony-stimulating factor (G-CSF). Neutrophil activation was assessed by measurement of degranulation. Mobilization of secretory vesicles was shown by a decrease in leukocyte alkaline phosphatase content of the circulating neutrophils. Furthermore, shortly postinjection, Fc gamma RIII was found to be upregulated from an intracellular pool that we identified by immunoelectron microscopy as secretory vesicles. Intravascular release of specific granules was shown by increased plasma levels of lactoferrin and by upregulation of the expression of CD66b and CD11b on circulating neutrophils. Moreover, measurement of fourfold elevated plasma levels of elastase, bound to its physiologic inhibitor alpha 1- antitrypsin, indicated mobilization of azurophil granules. However, no expression of CD63, a marker of azurophil granules, was observed on circulating neutrophils. G-CSF--induced mobilization of secretory vesicles and specific granules could be mimicked in whole blood cultures in vitro, in contrast to release of azurophil granules. Therefore, we postulate that the most activated neutrophils leave the circulation, as observed shortly postinjection, and undergo subsequent stimulation in the endothelial microenvironment, resulting in mobilization of azurophil granules. Our data demonstrate that G-CSF should be regarded as a potent immediate activator of neutrophils in vivo.     

Evaluation of erythropoiesis in long-term hamster bone marrow suspension cultures: absence of a requirement for adherent monolayer cells

In long-term hamster bone marrow cultures, proliferation and differentiation of hemopoietic stem cells occurs for several months without need for hydrocortisone or adherent stromal elements, which are requirements for bone marrow growth in all other species studied. Only the most primitive erythroid progenitors (BFU-E) are produced in the cultures. Following treatment of the cells with erythropoietin, these progenitor cells undergo differentiation into mature hemoglobinized red blood cells. Concomitant addition of erythropoietin (Epo) and prostaglandin-E1 (PGE1) results in the production of large numbers of maturing red blood cells. In cultures stimulated with Epo and PGE1, as many as 70% of the cells are benzidine-positive, while Epo alone stimulated as many as 45% of the cells to become erythroid. Epo and PGE1 do not have any apparent deleterious effect on the continuous hemopoiesis occurring in these cultures. Under identical conditions, syngeneic adherent cell cultures do not produce any erythroid elements. The development of mature red blood cells from primitive erythroid precursors occurs in the presence of Epo alone and without any apparent need for adherent stromal elements. These cultures provide a useful in vitro model for dissecting the positive and negative signals that regulate erythropoiesis.     

Diffuse large cell lymphoma in a patient with hairy cell leukemia: immunoglobulin gene analysis reveals separate clonal origins

A 75-year-old man with hairy cell leukemia (HCL) was found to have an immunoblastic lymphoma of the small bowel. Immunologic and genotypic characterization of these neoplasms revealed both the HCL and the immunoblastic lymphoma to be of the B cell lineage. The HCL expressed the HCL-associated antigens detected by the monoclonal antibodies HC-1 and HC-2, whereas the immunoblastic lymphoma failed to react with these antibodies. In addition, surface immunoglobulin light chains could not be accurately determined for the hairy cells, whereas the immunoblastic lymphoma was shown to express only kappa immunoglobulin light chains. These immunophenotype differences were compatible with either the clonal evolution of the HCL into the immunoblastic lymphoma or a separate clonal origin for these two neoplasms. An analysis of tumor DNA by Southern blot hybridization revealed different heavy-chain and kappa light-chain gene rearrangements in these two malignancies. Thus the occurrence of the large cell lymphoma most likely represents the emergence of a second clonally unrelated B cell malignancy.     

Maintenance of murine long-term repopulating stem cells in ex vivo culture is affected by modulation of transforming growth factor-beta but not macrophage inflammatory protein-1 alpha activities

Transforming growth factor-beta (TGF-beta) and macrophage inflammatory protein-l alpha (MIP-1 alpha) are both well-described inhibitors of committed and multipotential hematopoietic progenitors. The effect of these cytokines; on true stem cell activity in ex vivo culture systems as assayed by murine long-term repopulating activity (LTRA) has not been examined. We studied the stem cell effects of the addition of these cytokines to ex vivo cultures containing interleukin-3 (IL-3), IL- 6, and stem cell factor (SCF), using the murine competitive repopulation assay. We also tested the impact of adding an anti-TGF- beta neutralizing antibody, to ask whether abrogation of autocrine/paracrine TGF-beta may protect or enhance the survival of LTRA during ex vivo culture. TGF-beta 1 had significant suppressive effects on both short- and long-term repopulating activities, and anti- TGF-beta antibody had enhancing effects compared with control cultures containing IL-3, IL-6, and SCF alone. MIP-1 alpha had no significant effects on either short- or long-term repopulating ability. These data suggest that abrogation of TGF-beta during suspension culture may allow enhanced survival or even expansion of primitive cells ex vivo, with implications for many applications, including gene therapy.     

Inhibition of factor XII in septic baboons attenuates the activation of complement and fibrinolytic systems and reduces the release of interleukin-6 and neutrophil elastase

In previous studies, we have shown that administration of monoclonal antibody (MoAb) C6B7 against human factor XII to baboons challenged with a lethal dose of Escherichia coli abrogates activation of the contact system and modulates secondary hypotension. To evaluate the contribution of activated contact proteases to the appearance of other inflammatory mediators in this experimental model of sepsis, we studied the effect of administration of MoAb C6B7 on activation of complement and fibrinolytic cascades, stimulation of neutrophil degranulation, and release of the proinflammatory cytokines, tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6). Activation of the complement system, as reflected by circulating C3b/c and C4b/c levels, was significantly reduced in five animals that had received MoAb C6B7 before a lethal dose of E coli as compared with five control animals that had been given a lethal challenge only. Inhibition of contact activation also modulated the fibrinolytic response, since the release of tissue-type plasminogen activator (t-PA) and the appearance of plasmin-alpha2-antiplasmin (PAP) complexes into the circulation was significantly attenuated upon pretreatment with anti-factor XII MoAb. In contrast, plasma levels of plasminogen activator inhibitor (PAI) were modestly enhanced in the treatment group. Degranulation of neutrophils, as assessed by circulating elastase-alpha1-protease inhibitor complexes, and release of IL-6 but not of TNF-alpha was decreased in anti-factor XII-treated animals. Observed differences in the inflammatory response between treatment and control groups were not likely due to different challenges, since the number of E coli that had been infused, as well as circulating levels of endotoxin after the challenge, were similar for both groups. These data suggest that activation of the contact system modulates directly or indirectly various mediator systems involved in the inflammatory response during severe sepsis in nonhuman primates.     

Oral lichenoid drug eruptions

OBJECTIVES: To identify, from amongst drugs reported as causing lichenoid drug eruptions, those affecting the oral mucous membranes and to review the clinical, histo-logical and immunological features of such oral lichenoid drug eruptions in comparison to oral lichen planus, amalgam contact lesions and lichen planus-like eruption in graft-versus-host disease (GVHD).
DATA SOURCES: Ovid® Medline data searches on CD-Rom were carried out for the years 1966–1996 to identify reports of oral lichenoid drug eruptions and their clinical, histological and immunological featureS. Articles retrieved were examined for further appropriate references in the period 1940–1996.
DATA EXTRACTION AND SYNTHESIS: Each paper was critically examined for evidence of a clinically verifiable lichenoid drug eruption affecting the oral mucous membranes and the effects of subsequent drug withdrawal. Available clinical, histological and immunological features were recorded. The papers examined were too diverse in nature to permit a structured criticism. The extracted data have been tabulated where appropriate.
CONCLUSIONS: The reports of oral lichenoid drug eruptions are considerably fewer than those of cutaneous eruptions and fewer drugs have been reported as causing oral rather than cutaneous lichenoid eruptionS. Histology and immunology cannot be used reliably to differentiate lichenoid drug eruptions from idiopathic lichen planus, amalgam contact lesions and lichen planus-like eruption in GVHD. Lichenoid drug eruptions may also show some histological characteristics of oral discoid lupus erythematosuS. An accepted protocol agreed by a number of international centres would permit the gathering of substantial information on LDE and could lead to a greater understanding of the mechanisms involved.     

Donor screening for antibody to hepatitis B core antigen and hepatitis B virus infection in transfusion recipients

BACKGROUND: Testing for antibody to hepatitis B core antigen (anti-HBc) as a surrogate for hepatitis C viremia is no longer needed for blood donor screening. Currently, the important question is how much its use supplements hepatitis B surface antigen (HBsAg) donor screening in preventing transfusion-transmitted hepatitis B virus (HBV) infection. STUDY DESIGN AND METHODS: In a study conducted in the 1970s, 64 blood donors were associated with 15 cases of HBV (1.0%) in 1533 transfusion recipients. Sera from 61 donors at donation and 29 follow-up visits were available for present-day assays for HBsAg, HBV DNA, anti-HBc, and antibody to HBsAg (anti-HBs). RESULTS: HBsAg was found in four previously negative blood donors; HBV DNA was limited to three of these four. Anti-HBc was detected in six HBsAg-negative donors. Two other donors were negative in all assays at donation, but positive for anti- HBc and anti-HBs 2 to 4 months later. The remaining donors were negative for all HBV markers, which left five recipient cases unexplained. No HBV transmission was observed when anti-HBs sample-to- negative control values were > or = 10. CONCLUSION: Some 33 to 50 percent of cases of hepatitis B that could be transmitted by transfusion of blood from HBsAg-negative donors are prevented by anti- HBc screening. Anti-HBc-positive donors unequivocally positive for anti- HBs should be considered noninfectious for HBV and should be allowed to donate. Anti-HBc screening of paid plasmapheresis donors, supplemented by anti-HBs testing, would reduce the amount of HBV to be processed by virus inactivation and increase the content of anti-HBs in plasma pools.     

Are there three types of Helicobacter pylori gastritis?

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