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N Basara

Publications and source records attributed to N Basara.

At least 55 records · Page 3Linked to original sources
PubMed1998

Mycophenolate mofetil for the treatment of acute and chronic GVHD in bone marrow transplant patients.

The efficacy and safety of mycophenolate mofetil (MMF) in combination with CsA and prednisolone for the treatment of acute and chronic GVHD (aGVHD and cGVHD, respectively) after BMT and PBSCT from HLA-mismatched and -matched donors was evaluated in an open single center trial. Twenty-four patients, 17-48 years of age, with acute (n = 17) and chronic GVHD (n = 7) were treated with 2 g MMF daily in addition to CsA and prednisolone. Overall grade improvement of aGVHD was found in 11 of 17 (65%) patients treated with MMF. MMF therapy in the treatment of cGVHD led to moderate improvement in three of six patients with limited cGVHD. The most common adverse hematologic events of MMF were leukopenia (n = 6), anemia (n = 4) and thrombocytopenia (n = 3). Hematological adverse events were not severe and did not require the discontinuation of MMF. In this preliminary study, we have shown that MMF can be used safely for the treatment of aGVHD. In addition, the MMF therapy resulted in significant dose reduction of prednisolone for the treatment of GVHD.

Acute Disease↗
PubMed1998

Total body irradiation and cyclophosphamide is a conditioning regimen for unrelated bone marrow transplantation in a patient with chronic myelogenous leukemia and renal failure on hemodialysis.

Five years after the diagnosis of Ph chromosome-positive chronic myeloid leukemia (CML) a 31-year-old patient developed malignant nephrosclerosis with renal failure. He then underwent an allogeneic unrelated BMT in first chronic phase CML. The preparative regimen consisted of fractionated total body irradiation (TBI) and cyclophosphamide (CY). We studied the pharmacokinetics of cyclophosphamide on hemodialysis and compared clinical parameters including time to engraftment and toxicity with parameters of a patient with normal renal function who also received an unrelated marrow as treatment for CML in first chronic phase. Our results suggest that TBI/CY is a suitable conditioning regimen for allogeneic transplantation in patients with hematological malignancy and renal failure on hemodialysis.

Adult↗
PubMed1998

Chronic eosinophilic leukemia: successful treatment with an unrelated bone marrow transplantation.

The optimal treatment of eosinophilic leukemia is still uncertain. We report the successful treatment of a 21-year-old patient with eosinophilic leukemia, without cytogenetic abnormalities, by bone marrow transplantation from an unrelated donor. The conditioning regimen for the transplantation consisted of fractionated total body irradiation and cyclophosphamide. Acute GVHD, grade I, post-transplantation was successfully treated. No other severe complications occured. The patient is alive in complete remission 21 months after unrelated bone marrow transplantation.

Adult↗
PubMed1996

The inhibitory effect of human macrophage inflammatory protein-1 alpha (LD78) on acute myeloid leukemia cells in vitro.

Macrophage inflammatory protein-1 alpha (MIP-1 alpha) has recently been shown to inhibit proliferation of immature hemopoietic progenitors. In addition, significant inhibition of early and mature leukemic progenitors in acute myeloid leukemia (AML) has been obtained with MIP-1 alpha. We performed a study of 25 AML patients at diagnosis to evaluate the effect of a human homolog of MIP-1 alpha (LD78) on bone marrow (BM) and peripheral blood (PB) leukemic progenitors (colony-forming unit-AML [CFU-AML]) and AML cell proliferation. A methylcellulose culture system was used for CFU-AML and incorporation of 3H-TdR for AML cell proliferation. We found that LD78 inhibits CFU-AML colony formation up to 100% for the BM in 14/16 samples studied with the average maximal inhibition of 62.7 +/- 9.1% and up to 100% for the PB in 12/13 samples studied with the average maximal inhibition of 71.4 +/- 9.9%. In addition to this, LD78 inhibited AML cell proliferation up to 60% for the BM in 10/18 samples studied with the average maximal inhibition of 17.8 +/- 3.5%, and up to 87.1% for the PB cell proliferation in 10/16 samples studied with the average maximal inhibition of 27.5 +/- 6.8%. Our results have shown that LD78 is more active on AML progenitors than on AML cell proliferation. Inhibition of the AML cells, although less than that of the progenitors, indicates that more limited activity of LD78 on more mature leukemic cells is present in AML.

Adolescent↗
PubMed1996

Carboxy-terminal peptides (C1-24 and C13-24 but not C1-13) of platelet factor 4 inhibit murine megakaryocytopoiesis, an activity which is neutralized by heparin.

Negative regulation of megakaryocytopoiesis is a complex process involving various cytokines. One of these cytokines is platelet factor 4 (PF4), a megakaryocyte/platelet specific protein. PF4 and a carboxy-terminal peptide related to PF4 have been reported to inhibit human and murine megakaryocytopoiesis. The growth of several megakaryoblastic cell lines: human erythroleukaemia cell line (HEL). Meg-01 and Dami, was also inhibited by PF4 and a 13-24 carboxy-terminal peptide related to PF4. We report that peptides corresponding to the 1-24 and 13-24 but not 1-13 carboxy-terminal region of PF4 inhibit murine megakaryocytopoiesis both in vivo (5 micrograms/inj) and in vitro (2.5 and 5 micrograms/ml). Moreover, such an inhibitory activity of PF4-related peptides is abrogated by heparin (5 IU/dish). These overall data indicate that carboxy-terminal PF4-related peptides retain the inhibitory effect of PF4 on both murine single MK and CFU-MK in vivo and in vitro by acting on an early stage of megakaryocytopoiesis and strongly suggest that the inhibitory activity of the multi-functional PF4 might be localized in a short carboxy-terminal region which might include, in part, the PF4 heparin binding domain.

Amino Acid Sequence↗
PubMed1996

Megakaryocyte progenitors in paroxysmal nocturnal haemoglobinuria are sensitive to complement.

We have investigated growth in vitro of bone marrow megakaryocytic progenitors (CFU-Mk) in 7 patients with paroxysmal nocturnal haemoglobinuria (PNH) to determine the sensitivity of CFU-Mk to complement. Bone marrow light density mononuclear cells were exposed to fresh or heat-inactivated AB human serum in the presence of medium or isotonic sucrose solution. We found that the proliferative activity of bone marrow CFU-Mk in PNH patients was significantly lower than in controls. In addition, the number of CFU-Mk in PNH bone marrow cells exposed to isotonic sucrose and complement was reduced to 25% of that in PNH cells exposed to isotonic sucrose without complement. In conclusion, our finding showed an increased sensitivity of CFU-Mk in PNH bone marrow cells to complement, supporting the hypothesis that the PNH defect is present at the level of CFU-Mk.

Complement System Proteins↗
PubMed1995

The determination of spontaneous megakaryocyte colony formation is an unequivocal test for discrimination between essential thrombocythaemia and reactive thrombocytosis.

Spontaneous colony formation from bone marrow megakaryocyte progenitors (BMsCFU-Mk) was studied in 24 patients with essential thrombocythaemia (ET), 20 patients with reactive thrombocytosis (RT), 20 patients with polycthaemia rubra vera with thrombocytosis (PRVtr), 16 patients with chronic myeloid leukaemia with thrombocytosis (CMLtr) and 18 normal control subjects (C). The culture medium which was used in the methylcellulose assay in vitro contained 30% of plasma from a single patient with hereditary haemochromatosis. Remarkable BMsCFU-Mk growth was recorded in all patients with ET but in none with RT or in C. BMs-CFU-Mk were present in 11/20 patients with PRVtr and 7/16 patients with CMLtr. Spontaneous bone marrow erythroid progenitors (BMsBFU-E) were also determined in these patients. BMsBFU-E were found in 21/24 patients with ET and none in the patients with RT and C. All patients with PRVtr and one patient with CMLtr showed BMsBFU-E. We conclude that our implementation of the in vitro methylcellulose assay allows the BMsCFU-Mk to be used as an unequivocal test for discrimination between ET and RT which has not been shown in previously published studies. In addition, we present evidence that in 10 patients BMsCFU-Mk and/or BMsBFU-E growth in the test persisted after long-lasting haematological remission.

Adult↗
PubMed1995

In vitro drug sensitivity of leukemic progenitors and P-glycoprotein expression in adult acute myeloid leukemia: correlation with induction treatment outcome.

We have investigated the self-renewal capacity (PE2) and in vitro sensitivity to cytosine-arabinoside (ara-C) and daunorubicine (DNR) of leukemic progenitors (CFU-AML) to determine the significance of these tests for predicting induction treatment outcome in 75 adult acute myeloid leukemia (AML) patients. In addition, in a part of this group of patients (n = 46) we determined the expression of P-glycoprotein (P-gp) immunocytochemically and correlated those results with the therapeutic response. We have evaluated 66 patients who showed the following responses: 28/66 complete remissions (CR), 16/66 resistant leukemias (RL) and 22/66 early deaths (ED). The PE2 value was significantly higher in patients with RL than in patients with CR (p < 0.00375). CFU-AML sensitivity to ara-C and DNR alone was not different between response groups, but the difference in CFU-AML sensitivity to the combination of drugs between patients with CR and RL was not significant, although a trend was noted (p < 0.06). P-gp expression was found in only 1/18 patients who achieved CR but in 9/11 patients with RL and 7/11 patients with ED, which is a highly significant difference (p < 0.0006). We concluded that both PE2 and P-gp expression in AML cells are valuable predictors of therapeutic response in adult AML and should be included in creating the best therapeutic approach to AML patients.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1995

Modulation of acute myeloblastic leukemia (AML) cell proliferation and blast colony formation by antisense oligomer for IL-1 beta converting enzyme (ICE) and IL-1 receptor antagonist (IL-1ra).

In the present study we investigated the effects of IL-1 antagonism on the autonomous growth of cells in acute myeloblastic leukemia (AML). To examine the role of pro-IL-1 processing, antisense technology was employed with 16-mer phosphorothioate oligodeoxynucleotide directed against human IL-1 beta converting enzyme (ICR) in 7 randomly selected AML cases. The addition of 10-75 microM of antisense oligonucleotide (but not of control oligonucleotide) significantly inhibited spontaneous proliferation of bone marrow- (BM) and peripheral blood- (PB) derived low density leukemic cells in a dose-dependent way. Similarly, spontaneous as well as induced CFU-AML colony formation was inhibited by human ICE antisense oligonucleotide with sample-to-sample variability. In separate experiments, in order to examine the effects of blockade of endogenously produced IL-1 to IL-1 receptors, the functional activity of human recombinant IL-1 receptor antagonist (IL-1ra) was tested. Continuous exposure to high concentrations of IL-1ra (up to 100 micrograms/ml) produced dose-dependent inhibition of spontaneous proliferation of the BM-derived blast cells from 9 of the 14 patients and of the PB-derived cells from 10 of the 14 patients. However, in some of these patients, the lower IL-1ra doses (down to 100 ng/ml) induced potentiation of spontaneous proliferation, suggesting a novel regulatory pathway for IL-1 receptor engagement. Similar results were obtained on CFU-AML colony formation, showing inhibition at higher IL-1ra doses, but in a few AML cases stimulatory effect at lower IL-1ra doses.(ABSTRACT TRUNCATED AT 250 WORDS)

Antineoplastic Agents↗
PubMed1994

Fraxiparin, a low-molecular-weight heparin, stimulates megakaryocytopoiesis in vitro and in vivo in mice.

The effect of a low-molecular-weight heparin, faxiparin (Nadroparin), on murine megakaryocytopoiesis in vitro and in vivo was studied in comparison with unfractionated heparin. The addition of fraxiparin at 1-20 IU/ml into plasma clot cultures but not serum-free agar culture significantly enhanced MK colony growth. Furthermore, fraxiparin was found to potentiate the stimulating activity of aplastic anaemia serum (AAS) but not stem cell factor (SCF), interleukin-3 (IL-3), granulocyte-macrophage colony-stimulating factor (GM-CSF) and erythropoietin (Epo), on MK colony growth in vitro, and to neutralize the inhibitory effect of platelet factor 4 (PF4) in vitro and in vivo. Fraxiparin also acted synergistically with heparin cofactor II and antithrombin III to promote megakaryocyte colony formation. Intraperitoneal administration of fraxiparin twice daily for 4 d at 0.1-25 IU/injection increased in mice the level of blood platelet counts and the number of single MKs and CFU-MK in bone marrow. These data demonstrate that fraxiparin is able to positively regulate megakaryocytopoiesis.

Animals↗
PubMed1994

Successful treatment of refractory pure red cell aplasia secondary to chronic lymphocytic leukaemia with cyclosporine A: correlation between clinical and in vitro effects.

This report presents the case of a patient with PRCA in CLL where in vitro culture studies correlated well with successful CS-A treatment. Before initiating CS-A therapy, coculture studies showed that T-cells from peripheral blood of the patient suppressed the formation of CFU-E and BFU-E colonies by normal bone marrow cells. Normal erythropoiesis reappeared in the bone marrow of the patient 3 weeks after the start of CS-A therapy. At this time, cocultures demonstrated that peripheral blood T-cells no longer inhibited the growth of normal BFU-E, although there was persistent suppression of CFU-E. Six months later the patient was in stable remission from PRCA on maintenance therapy with CS-A. Moreover, cocultures showed no T-cell inhibition of normal BFU-E or CFU-E colony formation. The strong correlation between in vitro culture studies and a beneficial clinical outcome observed in this case suggests that in vitro cultures could be used to monitor CS-A treatment in patients with PRCA in CLL.

Cyclosporine↗
PubMed1993

Decreased plasma proteins, increased total plasma-free amino acids, and disturbed amino acid metabolism in the hereditary severe anemia of the Belgrade laboratory (b/b) rat.

The plasma amino acid pattern has been investigated in severely anemic Belgrade laboratory (b/b) rats. Nonanemic heterozygous (b/+) or normal homozygous (+/+) rats of the same age (six weeks) were used as controls. Decreased plasma proteins, increased total free amino acid, and urea concentrations in plasma associated with increased urea and 3-methylhistidine urinary excretion were found, indicating protein and amino acid metabolic alterations in anemic b/b rats. Plasma alanine, glutamine, tyrosine, and phenylalanine concentrations were increased. The significantly reduced molar ratio between valine+leucine+isoleucine and phenylalanine+tyrosine suggested severe disturbance in the hepatic energy-producing system and derangement of hepatic energy status. Partial or complete reversal of the anemia within 3 days by red blood cell transfusion or within 3 weeks by iron treatment resulted in normalization of tyrosine, alanine, glutamine, and total amino acid concentrations in plasma, as well as of molar ratio between valine+leucine+isoleucine and phenylalanine+tyrosine. This indicated a better oxygen supply to the liver and normalization of the hepatic energy status. These findings suggest that the metabolic disturbances in the b/b rat are the consequence of hypoxia due to the severe anemia.

Alanine↗
PubMed1992

Hematopoietic growth factors in anemia of Belgrade laboratory (b/b) rats.

In this study, the extent to which growth factor production and microenvironment might be responsible for defective erythropoiesis and granulopoiesis in anemic b/b rats is investigated. Radioimmunoassay-determined serum erythropoietin (Epo) levels are high in b/b rats and closely related to degree of anemia. The low number of erythroid progenitors in b/b rats despite a high Epo level suggested that the defective erythropoiesis could be due to a low level of burst-promoting activity (BPA). A pokeweed mitogen-stimulated medium (PWM-SCM) was prepared with b/b rat spleen cells and used in normal and anemic rat bone marrow and spleen cultures to determine BPA and other growth factor levels. No erythroid burst-forming unit-derived colonies were found but granulocyte-macrophage colony-forming units were counted in significant number, suggesting that the production of growth factors that supports the growth of granulopoietic progenitors is not significantly disturbed. Because BPA is produced mainly by T-lymphocytes, the low BPA level in b/b rat PWM-SCM raised the question of the functional capacity of T-lymphocytes. Investigations showed a decrease in the proliferative activity of b/b rat spleen mitogen-activated T-lymphocytes to about 20% of controls as well as a decrease in interleukin-2 activity in b/b rat spleen cell supernatants. These results point to defective T-lymphocytes. A study of bone marrow fibroblastoid cell colonies (CFU-F) revealed significantly lower CFU-F counts in the b/b rats. This finding is indicative of a disturbed microenvironment, which could also to some extent be responsible for decreased growth factor production and depressed hematopoiesis in the b/b rat.

Anemia↗
PubMed1991

Abnormal megakaryocytopoiesis in the Belgrade laboratory rat.

The Belgrade laboratory (b/b) rat has a hereditary hypochromic microcytic anemia because of defective transmembrane iron transport into erythroblasts. The present study was prompted by our previous work in which we showed that the b/b rat has hypomegakaryocytic thrombocytopenia associated with increased megakaryocyte size. To define the basic mechanism underlying this abnormality in the b/b rat we have studied both megakaryocytopoiesis and granulopoiesis in anemic b/b rats, chronically transfused b/b rats, iron-treated b/b rats, and controls. We have found decreased concentrations of megakaryocyte and granulocyte progenitors in the marrow of b/b rats. Full correction of the severe anemia by chronic transfusion resulted in normalization of megakaryocyte progenitors, small acetylcholinesterase positive cells, megakaryocyte size, and platelet counts, along with granulocyte progenitors. In contrast, the partial correction of anemia obtained by iron treatment resulted in improvement, but not normalization, of these parameters. These findings indicate that abnormal megakaryocytopoiesis in the b/b rat can be best interpreted as a consequence of hypoxia because of the severe anemia. Because we have recently shown that the number of erythroid progenitors in b/b rats is also low, we propose that abnormal megakaryocytopoiesis in this animal is a reflection of an acquired stem cell disorder induced by the prolonged hypoxia resulting from the severe anemia.

Anemia, Hypochromic↗
PubMed1991

Dysmegakaryocytopoiesis and thrombocytosis in a patient with acute myelomonocytic leukemia and long evolution.

A patient with acute myelomonocytic leukemia (M4), dysmegakaryocytopoiesis and thrombocytosis is presented. Immunophenotyping and blast colony assay showed the presence of blasts with IaDr, CD 33 and CD 14 antigens. Cytogenetic analysis and level of thrombopoietin were normal. This atypical case represents yet another example of the transitional zone between atypical myeloproliferative disease and acute leukemia, and the apparent absence of any cytogenetic abnormality is noteworthy.

Humans↗