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Biomedical subjects

A Ganser

Publications and source records attributed to A Ganser.

At least 253 records · Page 14Linked to original sources
PubMed1988

Recombinant human granulocyte-macrophage colony-stimulating factor in patients with myelodysplastic syndromes--a phase-I/II trial.

A phase-I/II trial was initiated to study the effect of rhGM-CSF in patients with myelodysplastic syndromes who were not eligible for other kinds of therapy, rhGM-CSF was given to 9 patients in doses of 15 micrograms/m2-150 micrograms/m2 as an intravenous 8-h infusion for a cycle of 7 days followed by an interval of 14 days and a second 7-day treatment course. A dose-dependent increase in the leukocyte count was observed in 7 out of 9 patients. No change in reticulocyte numbers was seen and only 1 patient experienced an increase in platelet count. Toxicity mainly consisted of mild local phlebitis at the site of infusion and sternal pain after bolus injection.

Aged↗
PubMed1988

Establishment of two Epstein-Barr virus negative Burkitt cell lines from a patient with AIDS and B-cell lymphoma.

To analyze the pathogenesis of B-cell lymphomas in patients with acquired immunodeficiency syndrome (AIDS), we studied two cell lines, Es I and Es III, established from one such lymphoma for the presence of sequences of the Epstein-Barr virus (EBV) and the human immunodeficiency virus [HIV; lymphadenopathy-associated virus (LAV/HTLV-III)] as well as for the presence of cytogenetic abnormalities and monoclonal rearrangements of immunoglobulin and T-cell receptor genes. Both cell lines expressed the same IgM, kappa phenotype as the original lymphoma. The karyotype of Es I was 46, XY, t(8;14), 2 p+, inv (6p), 17p-, and the cells of Es III had an additional i(7q). Immunoglobulin gene studies demonstrated the identical monoclonal rearrangements in both cell lines. Neither EBV nor HIV sequences were detectable in the malignant B cells at the genomic level, leading to the conclusion that mechanisms other than transformation by EBV or HIV may have contributed to the B-cell lymphoma in this patient and possibly also to the generally increased frequency in patients with AIDS.

Acquired Immunodeficiency Syndrome↗
PubMed1988

In vitro and in vivo action of recombinant human GM-CSF (rhGM-CSF) in patients with myelodysplastic syndromes.

The availability of rhGM-CSF has allowed the in vivo treatment of patients with cytopenia. Therefore, a phase I-II trial was initiated to study the effect of rhGM-CSF in patients with myelodysplastic syndromes who were not eligible for other kinds of therapy. rhGM-CSF has been tested in 10 patients in doses from 15 micrograms/m2 to 150 micrograms/m2 given intravenously over 8 hours for a cycle of 7 days followed by an interval of 14 days and a second 7-day treatment course. A dose-dependent increase in leukocyte count was observed in 9 of 10 patients. No change in reticulocyte numbers was seen and only one patient experienced an increase in platelet count. Toxicity mainly consisted of mild phlebitis at the site of infusion and sternal pain after bolus injection. An increase in blast cell counts in some patients necessitated the start of low-dose Ara-C therapy.

Colony-Stimulating Factors↗
PubMed1988

Phase I/II study with GM-CSF in patients with myelodysplastic syndromes.

The availability of rh GM-CSF has allowed the in vivo treatment of patients with cytopenia. Therefore a phase I/II trial was initiated to study the effect of rh GM-CSF in patients with myelodysplastic syndromes who were not eligible for other kinds of therapy. rh GM-CSF has been tested in 10 patients in doses from 15 micrograms/m2 to 150 micrograms/m2 given intravenously over 8 hours for a cycle of 7 days followed by an interval of 14 days and a second 7-day treatment course. A dose dependent increase in leukocyte count was observed in 9 out of 10 patients. No change in reticulocyte numbers was seen and only one patient experienced an increase in platelet count. Toxicity mainly consisted of mild local phlebitis at the site of infusion and sternal pain after bolus injection. An increase in blast cell counts in some patients necessitated the start of low dose Ara-C therapy.

Colony-Stimulating Factors↗
PubMed1988

Effect of recombinant human granulocyte-macrophage colony-stimulating factor on the hemopoietic progenitor cells from patients with AIDS.

Derangement of the hemopoietic progenitor cells has been observed in the majority of patients with the acquired immunodeficiency syndrome (AIDS). In this study the effect of recombinant human GM-CSF was evaluated for the in vitro growth of hemopoietic progenitor cells from the bone marrow of patients with AIDS. A significant reduction of growth (mean +/- SEM) of CFU-GEMM (2.5 +/- 1.2), BFU-E (23 +/- 9), and CFU-GM (55 +/- 21) was found in AIDS patients in comparison to normal controls. There was a linear correlation between the number of CFU-GM growing in vitro after stimulation with rh GM-CSF as compared to medium conditioned by phytohemagglutinin-stimulated leukocytes (PHA-LCM). However, CFU-GM from patients with AIDS appear to need higher concentrations of rh GM-CSF for maximal growth.

Acquired Immunodeficiency Syndrome↗
PubMed1988

Recombinant gamma-interferon induces in vitro monocytic differentiation of blast cells from patients with acute nonlymphocytic leukemia and myelodysplastic syndromes.

gamma-Interferon (IFN-gamma) has previously been found to induce monocytic differentiation in established leukemic cell lines, such as HL-60 and U937. The aim of the present study was to evaluate the differentiative effect of highly purified recombinant (r)IFN-gamma on fresh bone marrow cells from patients with acute nonlymphocytic leukemia (n = 11) or myelodysplastic syndromes (n = 3). Blast cells were cultured in suspension in the presence or absence of rIFN-gamma (10-10(3) U/ml). While 6 out of 14 cases were unresponsive to rIFN-gamma in vitro, the remaining 8 patients showed a significant increase (0.05 greater than p greater than 0.001) in the percentage of cells expressing C3bi receptors, detected by OKM1 (median value in control cell, 9.5; median value in rIFN-gamma-treated cells, 31) and Mo1 (8.5 vs. 36), and in the percentage of cells expressing the monocytic antigens detected by Mo2 (8 vs. 28) and MY4 (6.5 vs. 32.5). In the responsive patients morphologic changes consistent with monocytic maturation, as well as a strong increase of alpha-naphthyl acetate esterase activity and of nitroblue tetrazolium reducing capability were observed upon culture with rIFN-gamma. We conclude that (a) rIFN-gamma may induce in vitro monocytic differentiation of blasts from acute nonlymphocytic leukemia and myelodysplastic syndrome patients, and that (b) this agent should be investigated for its capacity to be active in vivo.

Acute Disease↗
PubMed1988

Synergistic antiproliferative effect of recombinant interferon-gamma with recombinant interferon-alpha on chronic myelogenous leukemia hematopoietic progenitor cells (CFU-GEMM, CFU-Mk, BFU-E, and CFU-GM).

Recombinant interferons, alpha (rIFN-alpha) and gamma (rIFN-gamma), have been demonstrated to have significant antitumor activity as single agents in the treatment of chronic myelogenous leukemia (CML). Due to their possible synergistic efficacy, a combination rIFN therapy in CML has been proposed. To establish a biologic basis for this, we have studied the suppressive effects of rIFN-alpha and rIFN-gamma on the in vitro growth of CML-derived progenitor cells (CFU-GEMM, CFU-Mk, BFU-E, CFU-GM), the optimal conditions for rIFN synergism, and the possible role of hematopoietic accessory cells (T-lymphocytes and monocytes-macrophages) in mediating rIFN-induced growth inhibition. When added to unseparated bone marrow cells, rIFN-alpha and rIFN-gamma significantly reduced colony formation, with 50% inhibition occurring at 71 and 186 U/mL for CFU-GEMM, 40 and 152 U/mL for CFU-Mk, 222 and 1,458 U/mL for BFU-E, and 119 and 442 U/mL for CFU-GM, respectively. A small amount of rIFN-gamma (5 U/mL) acted synergistically with increasing doses of rIFN-alpha, and the values of 50% inhibitory concentrations fell outside the lower limit (10 U/mL) used in our experiments. This synergy was evident even when rIFN-gamma was added 72 hours after the initiation of cultures; however, it was completely lost when the target cells were depleted of accessory cells. When a low dose of rIFN-alpha (5 U/mL) was added to rIFN-gamma, the 50% inhibitory concentration values were decreased up to tenfold. These studies (1) confirm that CML-derived hematopoietic progenitors are responsive to the suppressive activity of both rIFN-alpha and rIFN-gamma in vitro, (2) demonstrate that different mechanisms are responsible for the suppressive activity of the two rIFNs, and (3) characterize their synergistic interaction, providing a basis for future clinical trials aimed at investigating combination rIFN therapy in CML.

Bone Marrow↗
PubMed1988

Constitutive expression of hematopoietic growth factor genes by acute myeloblastic leukemia cells.

Blast cell populations of forty nine individuals with acute myeloblastic leukemia (AML) were investigated for constitutive expression of genes for various hematopoietic growth factors. Fifteen samples constitutively exhibited messenger (m) RNA for colony stimulating factor for granulocytes (G-CSF). Eleven AML specimens produced mRNA specific for CSF for granulocyte and macrophages (GM-CSF). When probed for CSF for macrophages (M-CSF or CSF-1) specific hybridization signals became detectable in six samples. Five out of six blast cell populations transcribing M-CSF, synthesized G-, and GM-CSF mRNA's simultaneously, whereas another five leukemias transcribed G-, and GM-CSF genes exclusively. Furthermore, when specific bioassays were performed to detect secretion of biologically active CSF proteins by these leukemic blast samples, twelve out of fifteen G-CSF mRNA producing cell populations, eight out of eleven GM-CSF mRNA producing cell populations and one out of six M-CSF mRNA synthesizing samples, demonstrated release of the respective, functionally active CSF's into their culture supernatants. Our results show that gene transcription and protein secretion of hematopoietic growth factors are features that are frequently detected in leukemic myeloid blast cells and involve G-, GM-, and M-CSF. With respect to recent findings of receptiveness of leukemic colony forming cells (L-CFC) for proliferative stimuli provided by various hematopoietic growth factors, our findings point out a potential role of autocrineously produced CSF's in the pathophysiology of autonomous proliferation in AML.

Blotting, Northern↗
PubMed1988

Prognostic factors in a multicenter study for treatment of acute lymphoblastic leukemia in adults.

In a prospective multicenter study, 368 acute lymphoblastic leukemia (ALL) patients aged 15 to 65 years were treated with an intensified induction and reinduction regimen; 272 (73.9%) achieved complete remission (CR). The median remission duration (MRD) is 24.3 months, and the probability of being in continuous CR (CCR) at greater than 5 years is .37. The median survival for all 368 patients is 27.5 months, and the probability of being alive at 5 years is .39. For the 272 patients in remission the median survival is 58.4 months, and the probability of being alive at 5 years is .49. A lower CR rate was seen for patients with bleeding at diagnosis or with splenomegaly/hepatosplenomegaly. The prognostic factors unfavorable for remission duration were time to CR greater than 4 weeks v less than 4 weeks (P = .0002), age greater than 35 years v less than 35 years (P = .0008), leukocyte count greater than 30,000/microL v less than 30,000/microL (P = .0112), and null ALL v common ALL (c-ALL)/T cell ALL (T-ALL) (P = .05). The remission duration correlated strongly (P = .0001) with the number of these independent prognostic factors. In patients with none of these adverse factors the MRD has not yet been reached, with one adverse factor the MRD is 21.9 months, and with two or three adverse factors the MRD is only 9.6 months. For the immunologic subtype T-ALL, the probability of being in CCR at greater than 5 years is .55; for c-ALL, .34; and for null ALL, .24. According to these results, patients were stratified into a low-risk group with a CCR rate of .62 and a high-risk group with a CCR rate of .28, with the latter now allocated to either further chemotherapy or bone marrow transplantation in first remission.

Adolescent↗
PubMed1987

T cell receptor gamma chain variable gene rearrangements in acute lymphoblastic leukemias of T and B lineage.

The status of immunoglobulin and T cell receptor genes in acute lymphoblastic leukemia (ALL) of T and B lineage has been studied. Our data indicate that illegitimate gene rearrangements at immunoglobulin heavy chain (in T cell ALL), and T cell receptor beta chain (in pre-B ALL) genes are only rarely found (2 out of 30 patients). In contrast, T cell receptor gamma chain gene rearrangements, characteristically found in T-ALL, are also present in 7 of 18 patients with pre-B ALL. Several features distinguish these illegitimate T cell receptor gamma chain gene rearrangements from those in normal and leukemic T cells. V gamma genes located far upstream of the J gamma/C gamma complexes (V gamma 2, V gamma 3, V gamma 4, V gamma 5) appear to be preferentially used in normal adult peripheral blood T cells. In contrast, V gamma genes located immediately 5' to the J gamma/C gamma complexes (V gamma 8, V gamma 9, V gamma 10, V gamma 11) predominate in V gamma -J gamma recombinations observed in T-ALL and pre-B ALL. Whereas the J gamma 2 region is primarily used in T cell receptor gamma gene rearrangements observed in T-ALL, those in pre-B ALL are confined mostly to the J gamma 1 region. These data suggest a limited accessibility of the T cell receptor gamma chain gene locus for recombination processes in early stages of B cell differentiation.

B-Lymphocytes↗
PubMed1987

In vitro differentiation of a null-acute leukemia: T-lymphoid surface antigen expression associated with rearrangement in T-cell receptor beta chain variable genes.

We describe a human acute unclassified leukemia with a unique t(4;17) translocation that coexpresses T-lymphoid and myeloid surface antigens after in vitro culture in the presence of the tumor promoter, TPA. Under these conditions, the joining regions of the immunoglobulin heavy chain and T-cell receptor gamma and beta chain complexes remained in germ line configuration. A T-cell receptor beta chain variable gene probe, however, revealed the presence of rearrangements in the V beta M3-2 gene region after bilineage differentiation. These results may be pertinent to the interrelationship of T-cell receptor gene rearrangements and the control of T-cell antigen surface expression.

Acute Disease↗
PubMed1987

Defective in vitro growth of the hemopoietic progenitor cells in the acquired immunodeficiency syndrome.

In addition to immunologic derangement, hematological abnormalities have been reported in the majority of patients with acquired immunodeficiency syndrome (AIDS). In this study 15 patients with AIDS or AIDS-related complex (ARC) were evaluated for the in vitro growth of hemopoietic progenitor cells. In all patients a significant reduction of growth (mean +/- SEM) of colony-forming unit-granulocyte, erythrocyte, macrophage, (megakaryocyte) (CFU-GEM) (1.2 +/- 0.3), burst-forming unit-erythroid (BFU-E) (17 +/- 10), CFU-megakaryocyte (CFU-Mk) (1.7 +/- 0.6), and CFU-granulocyte-macrophage (CFU-GM) (35 +/- 10) was observed in comparison with normal controls. Depletion of T cells from the bone marrow before culture led to a significant increase in colony growth, which indicated an imbalance of the normally modulating T cell subsets. This increase was reversed by readdition of autologous T cells causing a decrease in colony growth to a degree, dependent on the T4 to T8 ratio. A decreased number of hemopoietic progenitor cells and/or a defective modulation of progenitor cell growth, normally carried out by T lymphocyte subsets, might be the cause of the hematological abnormalities in AIDS patients.

AIDS-Related Complex↗
PubMed1987

Human acute unclassified leukemia with a unique t(4;17) chromosomal translocation expresses T lymphoid and myeloid surface antigens after in vitro culture.

Bilineage differentiation along both the T lymphoid and the myeloid lineage while in in vivo diffusion chamber (DC) and in vitro suspension culture was observed in a case of acute unclassified leukemia (null-AL) and t(4;17). Prior to culture, the blast cells were TdT and la positive but did not express any lineage-specific antigenic markers. Furthermore, the immunoglobulin heavy chain and T cell receptor beta-chain genes were in germline configuration. Cytogenetically, all metaphases had the unique translocation t(4;17) (q25;q23) prior to and after culture, supporting the leukemic origin of the cells. During both DC culture and suspension culture with and without tetradecanoyl-phorbol-acetate (TPA), a substantial increase in the absolute and relative number of cells expressing both myeloid and T lymphoid antigenic markers occurred. Double-fluorescence analysis demonstrated the expression of antigenic markers of both lineages on the same population of cells, and electron microscopy revealed the induction of myeloperoxidase after both DC and suspension culture. Immunoglobulin heavy chain and T cell receptor beta-chain genes remained in germline configuration after treatment with TPA, when analyzed with JH and CT beta probes, respectively. These findings indicate that this case represents a null-AL with dual-lineage capabilities, which has probably arisen from the malignant transformation of a bipotential stem cell of lymphoid and myeloid progeny.

Antigens, Neoplasm↗