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Biomedical subjects

F Herrmann

Publications and source records attributed to F Herrmann.

At least 55 records · Page 3Linked to original sources

Expression of functional receptors for interleukin-6 by human polymorphonuclear leukocytes. Downregulation by granulocyte-macrophage colony-stimulating factor.

Surface interleukin-6 receptors were identified on human polymorphonuclear leukocytes (PMNL) by monoclonal anti p80-chain antibody MT 18 Cytoplasmic RNA harvested from PMNL also contained IL-6-R transcripts. Binding of recombinant human (rh) interleukin-6 (IL-6) to IL-6-R bearing PMNL was identified by flow cytometry using phycoerythrin (PE)-conjugated ligand. Treatment of PMNL with rh granulocyte-macrophage colony-stimulating factor (GM-CSF) led to the inability of PMNL to bind MT 18 monoclonal antibody (moAb) and to display binding sites for PE-conjugated rh IL-6. Levels of IL-6-R transcripts in PMNL exposed to GM-CSF were about 5-fold below those of PMNL cultured in medium only. Though a definitive role for IL-6 to modulate the function of PMNL was not found, treatment of PMNL with rh IL-6 clearly resulted in an enhancement of transcript levels of the early response genes c-fos and c-jun in these cells, thus indicating that IL-6 binding is followed by signal transduction.

Antibodies, Monoclonal

Treatment of aplastic anemia with antilymphocyte globulin and methylprednisolone with or without cyclosporine. The German Aplastic Anemia Study Group.

BACKGROUND AND METHODS: Immunosuppression is the most effective treatment for patients with aplastic anemia, except for bone marrow transplantation. The best results are achieved with antilymphocyte globulin or cyclosporine. Patients have been treated successfully with a combination of both agents, but there has been no controlled evaluation of its efficacy. We conducted a randomized, multicenter trial in 84 patients not eligible for bone marrow transplantation, comparing treatment with antilymphocyte globulin and methylprednisolone (41 patients--the control group) with antilymphocyte globulin, methylprednisolone, and cyclosporine (43 patients--the cyclosporine group). RESULTS: At three months significantly more patients in the cyclosporine group had a complete or partial remission in response to treatment than did patients in the control group (65 percent vs. 39 percent, P less than 0.03); this difference was confirmed at six months (70 percent vs. 46 percent, P less than 0.05). The superior results of the regimen including cyclosporine were most evident in the patients with severe or very severe aplastic anemia, whose response rate at six months was 65 percent, as compared with 31 percent of such patients in the control group (P less than 0.02). Granulocyte and hemoglobin levels became normal in most patients who responded, but platelet counts continued to be subnormal in 61 percent of the patients. Ten of 52 patients with responses (3 in the cyclosporine group and 7 in the control group) relapsed 4 to 37 months after treatment. The actuarial survival of all patients at 41 months is 64 percent in the cyclosporine group and 58 percent in the control group (P = 0.16); among the patients with severe or very severe disease, survival is 80 percent and 44 percent, respectively (P = 0.077). Cyclosporine had substantial but reversible side effects. CONCLUSIONS: Immunosuppressive treatment of aplastic anemia with antilymphocyte globulin, methylprednisolone, and cyclosporine appears to be more effective than a regimen of antilymphocyte globulin and methylprednisolone without cyclosporine and may thus represent a treatment of choice for patients who are not eligible for bone marrow transplantation.

Adult

Regulation of gene expression of macrophage-colony stimulating factor in human fibroblasts by the acute phase response mediators interleukin (IL)-1 beta, tumor necrosis factor-alpha and IL-6.

Fibroblasts constitute a major element of the bone marrow stroma. They play a pivotal role in blood cell development by providing the scaffolding required for cellular organization and tissue cohesion and by producing soluble molecules including colony stimulating factors (CSFs) and various interleukins regulating hematopoiesis. Our data demonstrate that the acute phase response mediators interleukin (IL)-1 beta, tumor necrosis factor (TNF)-alpha and IL-6 which are abundantly produced by activated monocytes, enhance levels of macrophage-colony stimulating factor (M-CSF) in fibroblasts by both transcriptional and post-transcriptional mechanisms. The action of these proteins to induce M-CSF transcript levels was dependent on synthesis of new proteins and was not mediated by protein kinase C (PKC) stimulation as depletion of cellular PKC pools by prolonged exposure of fibroblasts to phorbolester TPA did not prevent factor induced synthesis of M-CSF transcripts. However, blockade of PKC by the isoquinoline sulfonamide derivative H7 and thus inhibition of phosphorylation was associated with augmentation of the fibroblasts response to TNF-alpha and IL-6.

Fibroblasts

Expression of the c-fes proto-oncogene in granulocyte-macrophage colony-stimulating factor-dependent acute myelogenous leukemia cells grown autonomously.

In the present article, we show that 6 of 69 acute myelogenous leukemia (AML) samples exhibited autonomous in vitro growth that was dependent on endogenous granulocyte-macrophage colony-stimulating factor (GM-CSF). Cytoplasmic RNA harvested from all 6 leukemia specimens contained GM-CSF transcripts easily detectable by mRNA hybridization. All 6 GM-CSF-expressing leukemia samples simultaneously displayed high levels of transcripts for the c-fes proto-oncogene previously shown to be expressed in GM-CSF sensitive myeloid cells, whereas only 2 of the 48 AML samples not expressing GM-CSF accumulated c-fes mRNA. Seven of additional 14 GM-CSF-expressing specimens showed specific signals upon RNA hybridization with the c-fes probe, but failed to grow autonomously. These results suggest that c-fes and GM-CSF genes may be coordinately regulated in AML blasts and that GM-CSF-mediated growth autonomy may be linked to c-fes expression.

Cell Division

Recombinant human interleukin-3 in patients with hematopoietic failure.

Nine patients with bone marrow failure and prolonged severe cytopenias were treated with recombinant human interleukin-3 (rhIL-3) at doses ranging from 30 micrograms/m2 to 500 micrograms/m2. rhIL-3 was administered in a subcutaneous bolus injection daily for 15 days. Platelet counts increased by a mean of 6-fold (range: 1.3- to 14.3-fold) in five out of eight evaluable patients. Reticulocyte counts increased 2.9-fold in three patients, and neutrophil counts increased by a mean of 3.1-fold in all eight patients. Platelet transfusions could be discontinued after treatment with rhIL-3 in two out of three evaluable transfusion-dependent patients. Only mild side effects, mainly fever and headache, were observed. These results indicate that rhIL-3 functions as a multilineage hematopoietic growth factor in vivo in patients with secondary bone marrow failure.

Adult

Medullary histiocytosis following treatment of severe aplastic anemia with recombinant human interleukin-3 in combination with antilymphocyte globulin, cyclosporin A, and methylprednisolone.

This case report describes the clinical use of recombinant human interleukin-3 as adjunct to immunosuppressive therapy with antilymphocyte globulin, cyclosporin A, and methylprednisolone for refractory severe aplastic anemia. Hematopoietic response to treatment was moderate and peripheral blood counts (neutrophils, eosinophils, monocytes, reticulocytes) increased only slightly. Unexpectedly, during the time of interleukin-3 administration a substantial bone marrow infiltration by macrophages became detectable, consistent with the diagnosis of medullary histiocytosis, that may have prevented recovery of normal hematopoiesis in this patient. This observation may indicate the need for careful use of interleukin-3 in patients with drug-induced immunodeficiency.

Adult

Interleukin-6 in clinical medicine.

This article covers the basic biological functions of interleukin-6 (IL-6) in man. Three major topics are addressed more closely: the involvement of IL-6 in various disease states, particularly those of hematopoietic origin; the diagnostic usefulness of IL-6 measurements in biological fluids; the possible use of IL-6, IL-6 antagonists or IL-6 derivatives as therapeutic means.

Antineoplastic Agents

Phase I trial of recombinant human tumour necrosis factor alpha in patients with advanced malignancy.

A phase I clinical trial was conducted with recombinant human tumour necrosis factor alpha (rhTNF-alpha) in 62 patients with advanced malignancy refractory to previous standard therapy. rhTNF-alpha was given as a 30 min infusion twice a day at 6 h intervals. A total of 10 different dose levels was escalated in cohorts of 6 patients ranging from 2.5 to 200 micrograms/m2 twice a day for 5 days every second week for a total of 8 weeks followed by a 4-week observation period. Major side-effects of TNF-alpha therapy, seen in almost all patients studied, were fever and chills. As dose-limiting side-effects hypotension and liver toxicity were recorded in 4 of 5 patients treated with 200 micrograms/m2 twice a day. Pharmacokinetic studies revealed a TNF-alpha serum half-life of 13 to 25 min, a dose-dependent decrease in TNF clearance, and a dose-dependent increase in the area under the time/concentration curve. No anti-TNF-alpha antibodies could be detected, except in 1 patient. Tumour response to TNF treatment was poor. Only in 3 of 57 evaluable patients was partial tumour regression observed.

Adolescent

Hemopoietins in clinical oncology.

Despite major advances in supportive care, neutropenic infections and thrombopenic bleedings remain major lethal treatment- and disease-related complications in patients with malignancy. Moreover, complications of platelet (Plt) and erythrocyte transfusion therapy have become a cause of great concern and shortages of homologous blood products are a constant problem. Suggestions that the application of recombinant human hemopoietins may provide an alternative treatment modality in this patient population is currently being evaluated in clinical trials. Erythropoietin (EPO) has been shown to be effective in the treatment of anemia in patients with bone marrow, infiltrating low-grade non-Hodgkin's lymphoma, multiple myeloma, and in some patients with myelodysplastic syndrome. Preliminary data suggest that subcutaneous administration of EPO results in a higher slope of increasing erythropoietic parameters compared to intravenous administration. Protective effects on normal erythropoiesis have been attributed to EPO in patients receiving chemotherapy. The finding of EPO receptors on megakaryocytes supports the clinical observation of increased Plt production associated with decreased bleeding and transfusion frequencies in a substantial number of patients receiving EPO. Clinical trials with granulocyte-macrophage (GM-CSF) and granulocyte colony stimulating factor (G-CSF) have reached phase III trials. Both factors show high efficacy to shorten or improve neutropenia related to chemotherapy, bone marrow transplant, or underlying disease. Mechanisms responsible for mucosa protection and improved healing of mucositis observed with both factors remain undetermined yet phase I/II evaluation of IL-3 shows multilineage hemopoietic responses including myeloid, erythroid, and megakaryocyte lineages. Possible anti-cancer effects of hemopoietins achieved by direct action or by increased chemotherapy intensity are currently under investigation.

Animals

Clinical effects of recombinant human interleukin-3.

Interleukin-3 (IL-3) is a glycoprotein belonging to the hematopoietic growth factor family that in preclinical in vitro and in vivo studies has exhibited a multilineage activity. Phase I/II trials with recombinant human IL-3 (rhIL-3) expressed in yeast are being done in patients with advanced malignancies as well as in patients with bone marrow failure states. Subcutaneous administration of rhIL-3 at dosages between 30 and 500 micrograms/m2 for 15 consecutive days has resulted in a dose-dependent increase in platelet counts as well as in a substantial increase in the number of circulating neutrophils, eosinophils, monocytes, and lymphocytes in patients with advanced malignancies but normal hematopoiesis. Erythropoiesis is less stimulated with an increase in hemoglobin concentration only in a minority of patients. In patients with secondary hematopoietic failure due to prolonged chemo-/radiotherapy or bone marrow infiltration by tumor cells, treatment with rhIL-3 leads to a clinically significant restoration of hematopoiesis, especially of thrombopoiesis and granulopoiesis. rhIL-3 has also been shown to improve neutrophil and platelet counts in patients with myelodysplastic syndromes, while improvement of hematopoiesis is rarely observed in patients with severe aplastic anemia with the presently used treatment schedules. Adverse effects of rhIL-3 are minor at the clinically used dosages and include fever, bone pain, headache, and stiffness of the neck. Transient thrombocytopenia has been observed in a few patients with myelodysplastic syndrome or aplastic anemia treated at dosages of 250-500 micrograms/m2. rhIL-3 is a multilineage hematopoietic cytokine with promising effects on platelet and neutrophil counts and special usefulness in patients with secondary hematopoietic failure.

Anemia, Aplastic

Adding more fluid to wheat bran has no significant effects on intestinal functions of healthy subjects.

To regulate intestinal transit, increased fluid intake, along with fiber is recommended. Considering the usually large volumes of intestinal secretion, this advice is questionable. To demonstrate the effects of adding fluid to fiber, 11 volunteers ingested 15 g of wheat bran twice a day, randomly given without or with 600 mL of additional fluid. Stool weight and frequency were similarly increased in the two settings. Gastric emptying was delayed by bran only when bran was given without additional fluid. Orocecal transit showed no significant changes. Whole gut transit was slightly more accelerated with added fluid (20.6 vs. 13.5%). No test showed significant differences in direct comparison of bran and bran with additional fluid. We conclude that in healthy persons, such effects of wheat bran as acceleration of transit and increase in stool weight and frequency do not depend on an additional intake of fluid.

Adult

Regulation of M-CSF expression by M-CSF: role of protein kinase C and transcription factor NF kappa B.

Macrophage-colony-stimulating factor (M-CSF), also referred to as CSF-1, regulates the survival, growth, differentiation and functional activity of monocytes by binding to a single class of high-affinity cell surface receptors, known to be the product of the c-fms protooncogene. The detection of both M-CSF and c-fms expression by cells of the monocyte lineage has suggested that M-CSF may act by an autocrine mechanism. Interestingly, it has been shown that M-CSF can induce the expression of its own gene. Although sensitivity to M-CSF can be modulated by regulation of receptor expression and function, M-CSF responsiveness is largely determined at a postreceptor level. To date, little is known about the intracellular pathway of M-CSF signal transduction. We have therefore investigated the changes in protein kinase C (PKC) activity upon exposure of monocytes to M-CSF. We show that M-CSF activates and translocates PKC. Inhibition of PKC by the isoquinoline derivative H7 abolishes induction of M-CSF by M-CSF. Furthermore, activation of PKC was pertussis-toxin-sensitive and was associated with the detection of an NF kappa B protein in nuclear extracts of M-CSF-induced blood monocytes but not in monocytes exposed to medium treatment only. The results suggest that M-CSF induction of M-CSF involves G proteins, PKC and NF kappa B.

Base Sequence

Hematopoietic growth factors: interactions and regulation of production.

Hematopoietic growth factors are the major regulatory molecules supporting constitutive and inducible hematopoiesis. Molecular biology techniques have led to the identification and cloning of a series of hematopoietic growth factor genes, and the synthesis of large amounts of these molecules has facilitated investigations or their physiological functions and the network of their interactions. The present article focuses on the role of hematopoietic growth factors, growth-factor-synergizing factors, and growth-factor-releasing factors in the regulation of proliferation, differentiation, and functional activation of hematopoietic stem cells and lineage-committed progenitor cells. Cellular sources of growth factors, signal transduction pathways involved in their gene activation and transcriptional and posttranscriptional mechanisms that govern regulation of expression of these genes are also detailed.

Animals

Clonal analysis of CD4+/CD8+ T cells in a patient with aplastic anemia.

T cell clones were established from peripheral blood of a patient with severe aplastic anemia. 8 of 18 individual clonal T cell populations stably coexpressed CD4 and CD8 molecules, a phenotype characteristic for thymocytes and a minor subpopulation of circulating T lymphocytes. Analysis of T cell receptor genes revealed identical rearrangements of T cell receptor beta chain genes, suggesting clonality of these T cells. CD4+/CD8+ T cells clones were found to be efficiently cytotoxic towards autologous lymphoblasts. Autocytotoxicity could be blocked by a CD3 MAb, a MAb specific for monomorphic MHC class II determinants, and particularly, by an MHC-DP-specific MAb, suggesting specificity for autologous DP molecules. Perhaps more important, CD4+/CD8+ T cell clones inhibited differentiation of autologous progenitor enriched bone marrow cells in vitro by a direct cell-mediated mechanism. These data suggest that circulating cytotoxic CD4+/CD8+ T cell clones specific for autologous MHC-DP determinants may be involved in hematopoietic failure in some cases of aplastic anemia.

Adult