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Biomedical subjects

A Ganser

Publications and source records attributed to A Ganser.

At least 199 records · Page 11Linked to original sources
PubMed1992

Influence of human recombinant interferon-alpha and interferon-gamma on bone marrow progenitor cells of HIV-positive individuals.

As a result of a pathophysiologically unexplainable bone marrow failure, most patients with progressive stages of human immunodeficiency virus (HIV) infection develop anemia, leukopenia, and thrombocytopenia. Besides the possibility of immune-mediated cytolysis or of direct viral infection of hemopoietic progenitor cells, the inhibitory influence of cytokines, for example interferon-alpha (IFN-alpha) and IFN-gamma, on hemopoiesis of HIV-infected patients might be considered as one parameter that contributes to myelosuppression. Therefore, progenitor cells from the bone marrow of HIV+ and HIV- persons were exposed to increasing concentrations of recombinant human IFN-alpha and IFN-gamma in methylcellulose assays. The colony formation of pluripotent (CFU-GEMM), erythroid (BFU-E), and granulocyte-macrophage (CFU-GM) progenitor cells was inhibited by both interferons. The 50% inhibitory doses (ID50) of IFN-alpha were 125.6 U/mL and 131.5 U/mL for BFU-E from HIV-infected persons and normal controls, respectively; the corresponding ID50 of IFN-alpha for CFU-GM growth was 1095.8 U/ml and above 3000 U/ml. When IFN-gamma was studied the ID50 was 341.7 and 2794.6 U/ml for BFU-E from HIV-infected and healthy individuals, respectively, while the ID50 for CFU-GM was above the highest dose levels in both groups (greater than 3000 U/ml). The ID50 for CFU-GEMM was below the lowest dose levels of IFN alpha and IFN gamma tested in both groups (less than 10 U/ml). The inhibitory effects could be specifically neutralized by monoclonal antibodies against IFN-alpha and IFN-gamma, thus confirming that the suppressive effects were due to the cytokines used.

Adult↗
PubMed1992

[Enhanced lymphocyte proliferation in the presence of epidermal cells of HIV-infected patients in vitro].

Clinical observations show that the HIV infection is often associated with affections of the skin. In order to examine the involvement of the epidermal immune system in the HIV infection, we determined accessory cell function of epidermal cells from HIV-1-infected patients. For this we measured the proliferative response of enriched CD(4+)-T-lymphocytes from HIV-infected patients and noninfected controls to stimulation with anti-CD3 and IL-2 in the presence of epidermal cells; the enhancement of the response is dependent on the presence of functionally intact accessory cells. The capacity of epidermal cells to increase the anti-CD3-stimulated T-cell proliferative response was significantly enhanced in HIV patients (CDC III/IVA) as compared with noninfected donors. It is discussed, whether the increased activity of epidermal cells from HIV-infected patients may be responsible for several of the dermal lesions in the course of an HIV infection as due to an enhanced production and release of epidermal cell-derived cytokines.

Adult↗
PubMed1992

Treatment of myelodysplastic syndromes with cytokines and cytotoxic drugs.

Clinical trials with hematopoietic growth factors (granulocyte-macrophage colony-stimulating factor [GM-CSF], granulocyte colony-stimulating factor [G-CSF], interleukin-3, erythropoietin] have been done in patients with myelodysplastic syndromes. Treatment with GM-CSF or G-CSF has resulted in an increase of neutrophil counts into the normal range in the vast majority of patients. Progression to acute leukemia does not appear to occur more frequently in the patients receiving GM-CSF or G-CSF. Increases in platelet counts and hemoglobin levels have been reported after treatment with interleukin-3 and erythropoietin, respectively, although the response is only seen in a minority of treated patients. Combination therapy with GM-CSF and low-dose cytosine arabinoside has been studied, but present data do not indicate an advantage over other treatment strategies. Cytogenetic and molecular genetic analyses demonstrate that both normal and malignant precursor cells are stimulated by cytokine therapy.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1992

Acute lymphoblastic leukemia with the (4;11) translocation: combined cytogenetic, immunological and molecular genetic analyses.

Five cases of acute leukemia (AL) with the t(4;11) translocation were investigated for the immunoglobulin heavy chain, kappa, lambda, TCR beta and TCR gamma gene rearrangements. All patients presented with high-risk features and had survival times of less than two years. Two cases were classified by immunological phenotyping as acute null-AL(L), one case as pre B-cell ALL (CD10+) and two cases expressed both immature B-cell markers CD19 and CD24 and myelomonocytic markers CD15 and CD14, suggesting mixed lineage leukemia. In two cases more than two rearranged fragments for the immunoglobulin heavy chain gene could be detected by Southern blot analysis. In the other cases at least one allele of the immunoglobulin heavy chain gene was rearranged. Germline configuration of the T-cell receptor genes and lack of light chain gene rearrangement suggest that an early B-precursor cell is involved in the transformational events in these cases of ALL. Our own and published data indicate that acute leukemia with t(4;11) translocation might be more frequently associated with more than two rearranged fragments for the immunoglobulin heavy chain genes and run a very aggressive course.

Adult↗
PubMed1992

Treatment of myelodysplastic syndromes with hematopoietic growth factors.

Clinical trials with hematopoietic growth factors (granulocyte-macrophage colony-stimulating factor [GM-CSF], granulocyte colony-stimulating factor [G-CSF], interleukin-3, or erythropoietin) have been performed on patients with myelodysplastic syndromes. Absolute neutrophil counts can be readily raised to within the normal range by treatment with GM-CSF or G-CSF. Increases in platelets and hemoglobin have been reported after treatment with interleukin-3 and erythropoietin, respectively. Cytogenetic and molecular genetic analyses have demonstrated that both normal and malignant precursor cells are stimulated by cytokine therapy.

Cytarabine↗
PubMed1992

Clinical course of myelodysplastic syndromes.

The myelodysplastic syndromes are a heterogeneous group of disease states ranging from relatively benign to aggressive forms. It is now possible to specify factors with prognostic value. Poor-prognosis factors that can easily be assessed are (1) bone marrow blasts exceeding 5% of the nucleated cells, (2) the presence of blast cells in the peripheral blood, (3) pancytopenia, and (4) a high Bournemouth, FAB, Düsseldorf, or Spanish score. Further important poor-prognosis features are (5) the presence of karyotypic abnormalities, (6) the finding of ALIP, and (7) a leukemic pattern of in vitro progenitor cell growth. The assessment of the value of therapeutic intervention either by treatment with hematopoietic growth factors or by chemotherapy will require the knowledge of the distribution of these features.

Diagnosis, Differential↗
PubMed1991

Ultrastructural demonstration of peroxidase expression in acute unclassified leukemias: correlation to immunophenotype and treatment outcome.

The lineage affinity of 57 cases of acute unclassified leukemias (AUL) was reevaluated by ultrastructural analysis of peroxidase expression (POEM) in combination with immunophenotyping and analysis of immunoglobulin gene configuration. Twenty-three cases of myeloid and three cases of megakaryocytic differentiation were identified by detection of ultrastructural myeloperoxidase (UMPO) and platelet peroxidase (UPPO). No significant correlation was noted between myeloid marker expression and POEM positivity, whereas presence of CD 19 or CD 24 antigen significantly correlated with POEM negativity (P = .001 and .023, respectively). Ig gene rearrangements including oligoclonal patterns were also recorded in 8 of 14 UMPO+ patients tested. Fourteen UMPO+ patients responded poorly to an ALL/AUL chemotherapy regimen with a low complete remission (CR) rate of 29% and a short median remission duration (MRD) of 5 months. The POEM- patients proved very heterogenous with respect to immunophenotype and Ig gene rearrangement. Seventeen of 21 patients tested had Ig gene rearrangements, including oligoclonal patterns. Combined data suggest that a proportion of these cases probably derive from a very immature lymphoid progenitor cell, particularly because 15 POEM- AUL patients showed a response to ALL/AUL chemotherapy comparable to that observed in patients with definitive acute lymphoblastic leukemia (ALL) (CR rate 80%, MRD 20 months). Thus, ultrastructural analysis of peroxidase expression can provide decisive prognostic information in AUL patients.

Acute Disease↗
PubMed1991

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↗
PubMed1991

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↗
PubMed1991

Effect of recombinant human transforming growth factor beta and tumor necrosis factor alpha on bone marrow progenitor cells of HIV-infected persons.

With progressive disease, the majority of patients with human immunodeficiency virus (HIV) infection develop bone marrow failure with anemia, leukopenia, and thrombocytopenia, the cause of which has not yet been clarified. Besides direct infection of bone marrow progenitor cells and immune-mediated cytolysis, the action of inhibitory cytokines, like transforming growth factor beta (TGF-beta) and tumor necrosis factor alpha (TNF-alpha), has to be discussed with regard to their pathophysiological role in HIV-induced bone marrow failure. Therefore, the influence of recombinant human TGF-beta and TNF-alpha on colony growth of pluripotent (CFU-GEMM), erythroid (BFU-E), and granulocyte-macrophage (CFU-GM) progenitor cells from the bone marrow of HIV-1-infected persons and normal controls was assessed in methylcellulose cultures. Both cytokines inhibited the colony formation of hematopoietic progenitor cells from HIV-positive persons. When added to unseparated bone marrow cells from HIV-infected persons and normal controls, the 50% inhibition (ID50) of BFU-E by TGF-beta occurred at 1.3 ng/ml and 3.7 ng/ml, respectively, while the ID50 of CFU-GM occurred at 15.5 ng/ml and 142.7 ng/ml. Concentrations of TNF-alpha, causing 50% inhibition of colony formation by bone marrow cells from HIV-infected or noninfected individuals were 6.3 U/ml and 17.0 U/ml for BFU-E, and 24.4 U/ml and greater than 3,000 U/ml for CFU-GM, respectively. The ID50 of the CFU-GEMM growth was below the lowest concentration of both cytokines tested. The suppressive effects were specifically abolished by antibodies against TGF-beta and TNF-alpha, thus confirming that the inhibitory activities were due to the cytokine preparation used.

Adult↗
PubMed1991

TIBO R82913, a new HIV-1 inhibiting agent, does not inhibit hematopoietic progenitor cells.

In progressive stages of infection with human immunodeficiency virus type 1 (HIV-1), the majority of patients develop a pathophysiologically not yet completely explainable bone marrow failure with anemia, leukopenia, and thrombocytopenia. The clinically most widely used HIV-inhibiting antiviral drugs azidothymidine (AZT) and dideoxyinosine (ddI) frequently are hematotoxic to the host, resulting in dose reduction or discontinuation of antiviral therapy. In recent studies, a novel series of benzodiazepine derivatives highly active against HIV-1 was synthesized. These antiviral compounds have a much more favorable therapeutical index than the well-known 2'3'-dideoxyribosides, like AZT. In the experiments presented here, the authors investigated the most promising derivative R82913 [(+)-S-4,5,6,7-tetrahydro-9-chloro-5-methyl- 6-(3-methyl-2-butenyl)-imidazo[4,5,1-jk] [1,4]-benzodiazepin-2(1H)-thione] (TIBO) with regard to its toxicity on bone marrow-derived hematopoietic progenitor cells from six HIV-1+ and HIV- persons, respectively. In methylcellulose assays for hematopoietic colony growth any hematotoxic effects of R82913 in vitro were excluded, as both groups showed no difference of progenitor cell growth with or without the TIBO derivative, even at concentrations 6.7 x 10(4) times higher than the 50% inhibitory concentration for cytopathicity by HIV-1.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Bone marrow findings after treatment with recombinant human interleukin-3.

In a phase I/II study, bone marrow biopsy specimens and aspirates of 20 patients with malignant tumors but normal bone marrow (n = 6), bone marrow failure resulting from chemotherapy (n = 4), myelodysplastic syndrome (n = 5), and aplastic anemia (n = 5) were evaluated before and after patients were treated with recombinant human interleukin-3 (rhIL-3). This cytokine proved to be an effective hematopoietic growth factor with only mild side effects. The rhIL-3 treatment led to increased overall bone marrow cellularity with trilinear stimulation of hematopoietic cells, except in most patients with aplastic anemia. In all patients, significant eosinophilia and, in some instances, bone marrow fibrosis developed. In addition to the increase in the number of circulating neutrophilic granulocytes, platelets, and reticulocytes, an increase of peripheral blood monocytes and lymphocytes was observed. The histologic and cytologic findings support the concept that rhIL-3 stimulates the proliferation and differentiation of pluripotent hematopoietic progenitor cells. It appears to be a safe and efficient therapeutic modality in patients with bone marrow failure. Additional clinical studies are needed to determine which patients will profit most from rhIL-3 treatment.

Adult↗
PubMed1991

The role of GM-CSF, G-CSF, interleukin-3, and erythropoietin in myelodysplastic syndromes.

Hematopoietic growth factors are being used in patients with myelodysplastic syndromes with increasing frequency to reverse pancytopenia. Treatment with granulocyte-macrophage colony stimulating factor (GM-CSF) and granulocyte colony stimulating factor (G-CSF) has resulted in an increase in segmented neutrophil counts and a reduction in the infection rate, whereas a stimulatory effect on platelet count and hematocrit was uncommon. Progression to acute leukemia has been observed, but could have been due to the natural course of the disease. Combination therapy with GM-CSF and low-dose cytosine-arabinoside is being studied in clinical trials. Early results with interleukin-3 have demonstrated a stimulatory effect on neutrophil counts as well as on platelet counts. High doses of erythropoietin have only been successful in 10% of treated patients to improve erythropoiesis.

Clone Cells↗
PubMed1991

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↗
PubMed1991

Biologic effects of recombinant human interleukin-3 in vivo.

The biologic in vivo effects of recombinant human interleukin-3 (rhIL-3) were assessed in a phase I clinical study of 30 patients with advanced malignancy. On day 1 rhIL-3 was administered by a single intravenous (IV) bolus injection, followed by subcutaneous (SC) injections once daily from day 2 to 15; at least three patients were treated at each dose level (60, 125, 250, and 500 micrograms/m2). A transient decrease of eosinophil and monocyte counts was observed immediately after IV injection of rhIL-3, whereas the neutrophil count remained unaffected. Total WBC counts and neutrophil counts increased dose dependently up to threefold, whereas a 10-fold to 50-fold rise was observed in levels of circulating eosinophils and basophils. Platelet counts increased up to twofold. Patients developed moderate increases of serum levels of soluble interleukin-2 receptors, beta 2-microglobin, and immunoglobulin M (IgM), and of the acute phase reactants, C-reactive protein (CRP), fibrinogen, and haptoglobin. An increase in interleukin-6 (IL-6) serum levels was detected in patients treated by IV bolus rhIL-3. The serum half-life of IV injected rhIL-3 was 20 +/- 3 minutes; after SC administration, 210 +/- 15 minutes. Administration of rhIL-3 was generally well tolerated, with mild fever, headache, and local reactions at the injection site being the most frequent side effects. The primary course of the underlying malignant diseases was not significantly altered by administration of rhIL-3. The results indicate that rhIL-3 acts in vivo as a multilineage hematopoietic growth factor and a weak inflammatory mediator that may be used successfully to improve states of hematopoietic failure.

Adult↗