SEARCH · Search PubMed

Results for “blast phase”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 955 records · Page 53Linked to original sources

PubMed1996

Progression from myelodysplastic syndrome to acute lymphoblastic leukaemia with Philadelphia chromosome and p190 BCR-ABL transcript.

We describe a patient with Philadelphia chromosome (Ph1)-positive acute lymphoblastic leukaemia (ALL) who developed it 2.5 years after being diagnosed with myelodysplastic syndrome (MDS). The patient initially had refractory anaemia (RA), but progressed to refractory anaemia with excess blasts (RAEB) 2 years later, that terminated in ALL. An immunophenotypic analysis of the lymphoblasts revealed CD10 and CD19 positive cells. The karyotype was normal 46,XY in RA phase, 46,XY,20q-during the RAEB phase, and 46,XY,t(9;22)(q34;q11),20q-during the ALL phase. Furthermore, p190 BCR-ABL mRNA was detected in the ALL blasts. These findings indicate that this ALL arose from the MDS clone through multiple cytogenetic evolutions, the final event of which was the acquisition of p190 BCR-ABL type Ph1.

Base Sequence↗

PubMed2003

Pharmacokinetics and pharmacodynamics of plasma clofarabine and cellular clofarabine triphosphate in patients with acute leukemias.

PURPOSE: The purpose of our study was to investigate the pharmacology of clofarabine and its triphosphate and the pharmacodynamic actions in circulating blasts obtained from acute leukemia patients who entered a Phase I clinical trial of clofarabine. EXPERIMENTAL DESIGN: Adults with refractory acute leukemias including lymphoblastic (ALL), myelogenous (AML) and chronic myelogenous leukemia in blastic phase (CML-BP) received clofarabine from 4 mg/m(2) to 55 mg/m2/day for 5 days as a 1-h i.v. infusion. A total of 26 of the 32 patients were studied for pharmacological investigations. RESULTS: The maximum tolerated dose was 40 mg/m2/day for 5 days. Plasma pharmacology studies done in 25 patients indicate a linear increase in the plasma clofarabine concentration with increasing doses. At 40 mg/m2 the median plasma clofarabine level was 1.5 micro M (range, 0.42-3.2 micro M; n = 7). Cellular pharmacokinetic studies done at the end of the first clofarabine infusion in 26 patients appeared dose proportional but showed a wide variation in the concentrations of clofarabine triphosphate. At the maximum tolerated dose, the concentration was a median 19 micro M (range, 3-52 micro M). In the majority of cases, more than 50% of the analog triphosphate was present at 24 h after infusion. Compared with clofarabine triphosphate concentration, the endogenous level of dATP was low, resulting in a favorable ratio of analog triphosphate:normal deoxynucleoside triphosphate (dNTP) for incorporation into DNA. In association with the accumulation of triphosphate, there was a decrease in DNA synthesis. At 40- and 55-mg/m2 doses, the inhibition of DNA synthesis was maintained to 24 h. CONCLUSIONS: Clofarabine at the maximum tolerated dose was effective with regard to inhibition of DNA synthesis and decline in circulating leukemia blasts. Given the clinical activity of clofarabine in adult acute leukemias, it is of interest to conduct a detailed characterization of the cellular pharmacology of clofarabine triphosphate and its relationship to clinical responses.

Adenine Nucleotides↗

PubMed1990

Trisomy 4: a specific karyotype anomaly in primary and secondary acute myeloid leukemia.

Trisomy 4 as single karyotype anomaly has recently been proposed as an acute myeloid leukemia (AML) specific aberration. Up to now, 20 cases have been reported in which the single abnormality occurred without additional chromosomal aberrations. Trisomy 4 has been found in both primary and secondary AML, the majority of cases being diagnosed as FAB M4 or M2 subtypes. In the cytogenetic analysis of 305 patients with AML, we found 209 cases with aberrant karyotypes, among them two patients (22a, male, M2; and 69a, male, M4) with trisomy 4 as single aberration. The younger patient achieved complete remission lasting 13 months and survived 22 months whereas the older patient died in aplastic phase due to septicaemia 5 weeks after admission. Trisomy 4 is proposed to be the primary aberration in both these cases of de novo AML. Although in one case, as in two cases reported earlier, cytogenetic results were only available in first relapse, we have no indication that trisomy 4 appeared in a secondary induced leukemia, because the leukemic blasts of the relapse were morphologically identical to first acute phase. In contrast to other specific chromosomal aberrations, results indicate that trisomy 4 has as yet no prognostic relevance concerning the clinical outcome.

Adult↗

PubMed1984

Analysis of myelomonocytic leukemic differentiation by a cell surface marker panel including a fucose-binding lectin from Lotus tetragonolobus.

The fucose-binding lectin from Lotus tetragonolobus ( FBL -L) has been previously shown to bind specifically to normal cells of the myeloid and monocytic lineages. The purpose of this study was to explore the utility of fluoresceinated FBL -L as a leukemia differentiation marker in conjunction with a panel of other frequently used surface markers (Fc receptor, HLA-DR, OKM1, and antimonocyte antibody). FBL -L reacted with leukemic cells in 8/9 cases of clinically recognized acute myeloid leukemia, including myeloid blast crisis of chronic granulocytic leukemia, 3/3 cases of chronic phase chronic myelogenous leukemia, and in 2/7 cases of clinically undifferentiated acute leukemia. Correlations were noted between reactivity with FBL -L, and DR and Fc receptor expression. Among continuous cell lines, FBL -L bound with high intensity to a majority of HL-60 and U937 cells. The less well differentiated myeloblast cell lines, KG-1, KG1a , and HL-60 blast II, exhibited less FBL -L binding than HL-60 and U937. A moderate proportion of K562 cells exhibited low level binding of FBL -L. Several lymphoblastic cell lines exhibited a pattern of low intensity binding that was distinguishable from the high intensity binding pattern of the myeloblastic lines. FBL -L reactivity of U937 was enhanced by induction of differentiation with leukocyte conditioned medium, but not dimethylsulfoxide. Such treatments induced contrasting patterns of change of HL-60 and U937 when labeled with OKM1, alpha-Mono, and HLA-DR. These studies demonstrate the application of FBL -L to analysis and quantitation of myelomonocytic leukemic differentiation.

Acute Disease↗

PubMed1996

Chest wall velocity as a predictor of nonauditory blast injury in a complex wave environment.

Previous blast injury prediction criteria have been based on exposure to classic Friedlander or ideal blast waves. An ideal waveform is characterized by an instantaneous rise to a peak overpressure that decays exponentially to ambient pressure followed by a negative phase. The prediction criteria did not address injuries resulting from exposure to complex blast waves. It was difficult to establish a simple relationship between the two because complex blast waves typically consist of multiple shocks with variable frequency content and intensity that may be superimposed on a slow rising quasistatic pressure pulse. This paper deals with the application of a single degree of freedom mathematical model, originally developed to measure the response of the thorax to Friedlander waves, to calculate chest wall velocities resulting from various complex blast loads. Experimental results with sheep, exposed to complex blast waves in enclosures, demonstrated that there was a good relationship between the Adjusted Severity of Injury Index (which includes injury to the lungs, upper respiratory tract, gastrointestinal tract and solid intraabdominal organs) and the calculated peak inward chest wall velocity. In addition, there was a good correlation between these results and previously established Friedlander injury prediction curves. The velocity of complex blast waves was nearly the same as that of Friedlander waves for a given degree of injury: 3-4.5 meters/second for threshold injury, 8-12 meters/second for an LD1, and 12-17 meters/second for an LD50.

Animals↗

PubMed1980

Chronic myeloid leukaemia: evidence for basophil differentiation and histamine synthesis from cultured peripheral blood cells.

We have attempted to assess basophil differentiation in vitro in 15 patients with chronic myeloid leukaemia (CML). Using a sensitive radioassay, whole blood histamine values were found to be elevated in 10 of 14 patients tested, and correlated well with peripheral blood basophil counts (r=¿70). In seven of nine CML patients, but not in controls, total histamine content of separated peripheral blood cells suspended in a modified Marbrook system was shown to rise after 7 d in vitro. Further study showed that both histamine (mean, five-fold increase) and basophils (mean, three-fold increase) were significantly elevated over control values at 1, 2 and 3 weeks in vitro. Total cell-associated histamine content (in pg per 100 viable cells) was greater in CML cultures than in controls at 3 weeks (P less than 0.01). Serial cultures of cells from one patient revealed substantial in vitro rises in basophils and histamine at an accelerated, but not at a chronic, phase of disease. Cells from this patient and two others studied at the time of blast crisis demonstrated higher indices of basophil and histamine increases when compared to the group of CML patients in chronic phases of the disease (P less than 0.05). We conclude that basophil precursors exist in increased numbers in the peripheral blood of CML patients. Assays for basophil differentiation may prove useful in following disease activity in this and other myeloproliferative disorders.

Adult↗

PubMed1999

Phase I trial of sequential topotecan followed by etoposide in adults with myeloid leukemia: a National Cancer Institute of Canada Clinical Trials Group Study.

Prolonged exposure to a topoisomerase I inhibitor may increase expression of topoisomerase II, making cells more susceptible inhibitors of that enzyme. This study was undertaken to establish the maximum tolerated dose (MTD) of a topotecan/topoisomerase II inhibitor sequential combination that may be active in acute leukemia, and to evaluate the effects of in vivo exposure to topotecan on topoisomerase II levels in leukemic blast cells as measured by image cytometry. Patients who were eligible for this phase I study had relapsed or refractory acute myeloid leukemia (< or = 2 prior regimens) or CML blast crisis (0 or 1 prior regimen). Topotecan was given as a 5 day continuous i.v. infusion and was to be escalated through three levels (1.5, 1.75 and 2.0 mg/m2 day), followed by etoposide at two dose levels (100 and 150 mg/m2) i.v. bolus days 6, 7 and 8. Topoisomerase IIalpha levels in leukemic blasts from bone marrow were measured by image cytometry prior to starting treatment, on day 5 of topotecan infusion and on day 28; and daily during topotecan in peripheral blood blasts. Dose-limiting toxicity was seen in two of six patients at the first dose level (topotecan 1.5 mg/m2/day, etoposide 100 mg/m2/day; > or = grade 3 mucositis in both cases). This cohort was expanded to 10 patients; no further non-hematologic dose-limiting toxicity was observed, but given the extent of toxicity seen, further dose escalation was judged not to be feasible. Topo IIalpha levels increased in peripheral blood blasts during the first 72 h of topotecan infusion and returned to near baseline by day 5, whereas levels appeared to decrease in bone marrow blasts by day 5 compared to pretreatment. One complete hematologic and cytogenetic remission in a patient with CML blast crisis was observed in the 10 patients evaluable for response. The sequential administration of topotecan 1.5 mg/m2/day continuous infusion for 5 days followed by etoposide 100 mg/m2/day x 3 is the recommended phase II dose for this schedule. Topotecan increases topo IIalpha expression in vivo in leukemia cells, but levels of the enzyme are cell cycle dependent. Pharmacodynamic evaluation of the sequential or combination administration of novel antileukemic agents may help improve treatment strategies in acute leukemia.

Acute Disease↗

PubMed1998

'Lymphoid' blast crisis of chronic myeloid leukaemia is associated with distinct clinicohaematological features.

It has been suggested that in blast crisis (BC) of chronic myeloid leukaemia (CML) the clinical and laboratory features of patients with 'lymphoid' phenotype differ from those of patients with non-lymphoid BC. In order to assess any differences, 97 patients consecutively diagnosed with BC that followed a known chronic phase of CML were analysed. 19 patients had 'lymphoid' BC: in 17 the blasts expressed a B-lineage phenotype: in the remaining two they corresponded to T lymphoblasts. Four cases of B-lineage phenotype BC were considered as biphenotypic, due to the co-expression of myeloperoxidase and one or two other myeloid markers (CD33, CD13 and CD68) on the blast cells; in the other six cases of B-lineage BC the blasts expressed one or both of the myeloid markers CD33 (n = 4) and CD13 (n = 3). Patients with 'lymphoid' BC seldom had an accelerated phase prior to BC (1/19 v 36/78 with non-lymphoid BC, P = 0.002), had less frequent splenomegaly (9/19 v 59/78, P = 0.03) and hepatomegaly (5/19 v 45/78, P = 0.02) and showed a higher degree of marrow blast infiltration (mean value 74 +/- 24% v 38 +/- 23%, P < 0.0001), lesser blood basophilia (2.2 +/- 2.5% v 8.2 +/- 7.8%, P < 0.0001), and higher serum albumin levels (P = 0.001) than those with non-lymphoid BC. 13 patients with 'lymphoid' BC (68.4%) showed a favourable response to chemotherapy regimens including vincristine and prednisone and, overall, 'lymphoid' BC patients survived significantly longer than the remainder (median survival 12 months v 4.7 months, P = 0.006). These results indicate that 'lymphoid' BC of CML has a distinct clinicohaematological profile and confirm the better prognosis of such patients.

Adolescent↗

PubMed2004

Blast injury research: modeling injury effects of landmines, bullets, and bombs.

Terrorist blasts and landmine injuries have become more common in the past several decades generating thousands of casualties. Preventive and prognostic measures are limited by the lack of knowledge of these complex events. Previous blast research has focused on primary blast injuries that involve the lung, despite musculoskeletal injuries being the most common. Through the use of instrumented cadavers, Hybrid III test dummies, and other surrogates, unique models of these events have been created. The investigations studied the effectiveness of antimine footwear, forces and injury mechanisms in temporary shelters subjected to blast, modeling of blast-induced glass fragmentation, and helmet deformation and injury potential under ballistic load. Despite blasts being much higher rate events than those seen in automotive blunt trauma, we were able to measure forces and create injury models. We found that antimine footwear will require additional development to be effective. Guidelines for shelter placement have been altered, and tempered glass seems to offer no protection when compared with annealed glass. Although these models are in their nascent phase, the thorough understanding of the biomechanical nature of these blast injuries will assist in developing strategies to reduce injuries and in the creation of forecasting models.

Biomechanical Phenomena↗

PubMed1989

Biochemically directed therapy of leukemia with tiazofurin, a selective blocker of inosine 5'-phosphate dehydrogenase activity.

Tiazofurin (2-beta-D-ribofuranosylthiazole-4-carboxamide, NSC 286193), a selective inhibitor of the activity of IMP dehydrogenase (EC 1.1.1.205), the rate-limiting enzyme of de novo GTP biosynthesis, provided in end stage leukemic patients a rapid decrease of IMP dehydrogenase activity and GTP concentration in the blast cells and a subsequent decline in blast cell count. Sixteen consecutive patients with end stage acute nonlymphocytic leukemia or myeloid blast crisis of chronic granulocytic leukemia were treated with tiazofurin. Allopurinol was also given to inhibit xanthine oxidase activity to decrease uric acid excretion and to elevate the serum concentration of hypoxanthine, which should competitively inhibit the activity of hypoxanthine-guanine phosphoribosyltransferase (EC 2.4.2.8), the salvage enzyme of guanylate synthesis. Assays of IMP dehydrogenase activity and GTP concentration in leukemic cells provided a method to monitor the impact of tiazofurin and allopurinol and to adjust the drug doses. In this group of patients with poor prognosis, five attained a complete hematological remission and one showed a hematological improvement. A marked antileukemic effect was seen in two other patients. All five evaluable patients with myeloid blast crisis of chronic granulocytic leukemia reentered the chronic phase of their disease. Five patients with acute nonlymphocytic leukemia were refractory to tiazofurin and three were unevaluable for hematological effect because of early severe complications. Responses with intermittent 5- to 15-day courses of tiazofurin lasted 3-10 months. Tiazofurin had a clear antiproliferative effect, but the pattern of hematological response indicated that it appeared to induce differentiation of leukemic cells. In spite of toxicity with severe or life-threatening complications in 11 of 16 patients, tiazofurin was better tolerated in most patients than other antileukemic treatment modalities and provided a rational, biochemically targeted, and biochemically monitored chemotherapy which should be of interest in the treatment of leukemias and as a paradigm in enzyme pattern-targeted chemotherapy.

Antimetabolites, Antineoplastic↗

PubMed1983

Near-haploid cell line in the blastic crisis of chronic myelogenous leukemia: a possible marker for lymphoid malignancy.

The blast cells of a 14-year-old patient in the blastic phase of chronic myelogenous leukemia (CML) were studied. Cellular morphology, presence of the enzyme terminal deoxynucleotidyl transferase (TdT), and reactivity to the common acute lymphoblastic leukemia antiserum (CALLA) substantiated a lymphoid blast cell line. Immunologic surface markers were nonreactive for E-rosette (T) cells and immunoglobulin-bearing (B) cells. Cytogenetic, studies revealed persistance of the Philadelphia chromosome and a near-haploid cell line, i.e., 28,XY,t(9;22), +14, +15, +21, +22(GTG). The patient responded to chemotherapy with vincristine, prednisone, and L-asparaginase, first line drugs used for remission-induction of acute lymphoblastic leukemia in childhood. We suggest that severe hypodiploidy or near-haploidy, along with TdT and CALLA, may provide more accurate prognostic information in patients with CML and the lymphoid blastic crisis.

Adolescent↗

PubMed1987

Ph-positive chronic myeloid leukemia with near-haploid conversion in vivo and establishment of a continuously growing cell line with similar cytogenetic pattern.

Blast cells from a 39-year-old man in the blastic phase of chronic myeloid leukemia, with a benign phase of 15 years duration, as well as a cell line arising from this cell population, were studied. Cellular morphology, cytochemical staining pattern, and absence of terminal deoxynucleotidyl transferase showed the blast cells to be of myeloid character. Cytogenetic studies revealed the presence of two near-haploid cell populations with +8 and +8, +15, respectively, both of them containing the translocation t(9;22) in the original tumor cell sample. The cell line derived from this patient's leukemic cell sample contained both near-haploid and hyperdiploid clones, the hyperdiploid clones being multiples of the near-haploid clone(s). All of the clones carried the t(9;22) in the form of a Philadelphia chromosome.

Adult↗

PubMed1994

Combination of hematopoietic growth factors containing IL-3 induce acute myeloid leukemia cell sensitization to cycle specific and cycle non-specific drugs.

Laboratory studies have suggested that hematopoietic growth factors (GF), combined with cytosine-arabinoside (Ara-C) can enhance cytotoxic effects of this agent against acute myeloid leukemia (AML) cells. While clinical trials based on this growth factor/chemotherapy combination (GF/CT) are progressing with discordant results, further information regarding the underlying mechanisms have been reported supporting this rationale and requiring additional investigation. To assess the role of cytokinetic changes in the GF/CT strategy and to evaluate if chemotherapeutic agents regimens other than Ara-C, when combined with GF, can enhance their cytotoxic effects, we have primed AML blasts with two cytokine combinations and then exposed these cells to the S-phase specific agent Ara-C as well as to the phase non-specific drug daunorubicin (DNR) and to the alkylating agent 4-hydroperoxycyclophosphamide (4-HC). The two cytokine combinations used for priming AML blasts were: (i) interleukin-3 (IL-3) + granulocyte-macrophage colony-stimulating factor (GM-CSF) + granulocyte colony-stimulating factor (G-CSF); and (ii) GM + G-CSF. Cytokinetic analysis in ten AML samples and clonogenic growth of leukemic colonies (CFU-L) in methylcellulose were used to detect proliferative and cytotoxic effects on AML samples. We report that in AML clonogenic cell growth can be stimulated by cytokines in 50% of the samples (4/8), and that Ara-C sensitization clearly occurs in two out of these four samples. Among the different cytokine combinations tested, the one containing IL-3 was the most effective through a cytokinetic mechanism consistent with recruitment (averaged G0 decrease p = 0.04; S-phase increase p = 0.005). Furthermore we observed increased cytotoxicity also to the phase non-specific drugs DNR and 4-HC, which may be mediated by other mechanisms recently described. We conclude that GF/CT combinations may also be beneficial in regimens containing drugs other than Ara-C, used for AML treatment, including bone marrow transplantation conditioning regimens.

Antineoplastic Agents↗

PubMed1989

[Multivariate analysis of prognostic factors influencing survival in chronic myelogenous leukemia].

Prognostic significance of disease features obtained at the time of initial diagnosis was analyzed in 90 patients with chronic myelogenous leukemia (CML) in chronic phase. Median survival of this population was 45.9 months. Univariate analysis revealed that splenomegaly, bone marrow basophils, bone marrow blasts, peripheral blood blasts, and bone marrow eosinophils were significant prognostic factors for survival, and that peripheral blood leukocytes counts, hemoglobin concentration, performance status, age and lymphadenopathy were factors with border line significance. There were multiple interrelationship among these disease features. Multivariate regression analysis identified that age, hemoglobin concentration, and bone marrow blasts were independent primarily significant prognostic factors for survival. The Cox model generated with three variables of age, hemoglobin concentration, and percent blasts in bone marrow provided a useful representation of risk status in the population. A hazard function derived from the patients population segregated patients into three groups with significantly different survival patterns: A lower risk group, an intermediate group and a high risk group of patients with median survival of 57.8, 49.8 and 38.4 months respectively. Survival after CML blast crisis was short and overall median survival of 54 patients with CML blast crisis was 6.4 months. A sole prognostic factor for survival in blast crisis identified by multivariate analysis was blast cell type at CML blast crisis and patients with lymphoid phenotype had a good prognosis with median survival of 9.8 months. Median survival of myeloid crisis was 4.2 months. No other disease features were identified as significant prognostic factors in the present patient population.

Adult↗

PubMed2004

Case of chronic-phase chronic myelogenous leukemia with an abdominal hematopoietic tumor of leukemic clone origin.

We report a 59-year-old man with chronic myelogenous leukemia (CML) in chronic phase who presented with a large abdominal tumor. Biopsy revealed proliferation of granulocytic-, erythroid-, and megakaryocytic-lineage cells in a retroperitoneal lymph node. The BCR/ABL fusion gene was detected on a paraffin-embedded tissue section of the lymph node by double-color fluorescence in situ hybridization, indicating an extramedullary hematopoietic tumor of CML origin. This patient has achieved a complete cytogenetic response for 19 months with imatinib mesylate (STI571; Gleevec), in association with the regression of the tumor. However, the development of an extramedullary tumor in chronic-phase CML generally indicates a poor prognosis, because it commonly consists of blast proliferation and is followed by blast crisis in the marrow within a few months. This case, therefore, points to the importance of histological examination of extramedullary tumors in CML for evaluation of disease status and for therapeutic decisions.

Benzamides↗

PubMed1994

Modulation of intracellular metabolism of cytosine arabinoside in acute myeloid leukemia by granulocyte-macrophage colony-stimulating factor.

The current study investigated the effect of granulocyte-macrophage colony-stimulating factor (GM-CSF) on the intracellular metabolism and cytotoxicity of 1-beta-D-arabinofuranosylcytosine (araC) in leukemic cells of 45 patients with acute myeloid leukemia (AML). AML blasts from bone marrow (BM) (n = 39) and peripheral blood (PB) (n = 17) were incubated for 48 h with or without GM-CSF (100 U/ml) followed by a concurrent treatment with increasing concentrations of araC (0.06-100 microM) for an additional 24 h. After GM-CSF a 1.5-8.4-fold (median 2.3) increase in 3H-araC incorporation into the DNA was observed in ten of 14 peripheral blast specimens and in 23 of 28 bone marrow samples, 18 of whom also showed an enhanced 3H-TdR incorporation (1.5-8.5-fold, median 2.0-fold). Four different types of response were identified when analyzing 3H-araC incorporation into the DNA of bone marrow samples in relation to the applied araC dose: (i) 8/28 cases had increases of the araC incorporation at all araC dose levels applied (0.06-100 microM), (ii) 12/28 at low araC concentrations only (0.06-1.0 microM), (iii) 3/28 at high araC concentrations only (10-100 microM), and (iv) 5/28 showed no increase at any dose level given. Hence, 20 of the 23 responding patients revealed a GM-CSF induced enhancement of araC incorporation at low or conventional doses of araC (0.06-1.0 microM). Fourteen of the 18 cases with concomitant rises of 3H-TdR and 3H-araC incorporation into the DNA after GM-CSF had elevated DNA polymerase alpha activity (16-531%, median 72%) and in ten cases overall DNA polymerase activity was enhanced (10-70%, median 22.5%). In contrast, thymidine kinase (TK) and deoxycytidine kinase (dCK) activity were elevated after GM-CSF in only ten and five patients, respectively. An increase in the fraction of cells in S phase was found in 11/21 bone marrow specimens and in 5/9 peripheral blast samples. However, no correlation was observed between increases in the proportion of cells in S phase and enhancements in enzyme activities. In 13 cases the cytotoxicity of araC with and without GM-CSF was assessed by means of a blast cell colony assay. Preincubation with GM-CSF increased the araC mediated cytotoxicity in ten of 13 patients by a median of 3.2-fold (range 2.2-229-fold). The respective LD50 values for araC were reduced from 0.45 to 0.19 microM on average.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗

PubMed2001

Burkitt's acute lymphoblastic leukaemia transformation after myelodysplastic syndrome.

We describe a patient with myelodysplastic syndrome (MDS) that transformed to Burkitt's acute lymphoblastic leukaemia (ALL). The leukaemic blasts were negative for peroxidase staining, and expressed CD10, CD19, CD22, CD38, human leucocyte antigen (HLA)-DR and surface immunoglobulin (sIg) M, but neither sIgD nor sIgG were expressed. Chromosomal study during the ALL phase showed t(8;22)(q24;q11) in addition to the karyotypes determined during the MDS phase. Furthermore, overexpression of c-myc mRNA was confirmed in ALL blasts. These findings indicate that MDS transformed to Burkitt's ALL through multiple cytogenetic evolutions, the final event of which seems to be overexpression of the c-myc gene.

Acute Disease↗

PubMed2001

Characterization of fugitive material within a primary lead smelter.

The primary production of Pb via the sinter plant-blast furnace method resulted in a large number of Pb and other phases, reflecting the complex reactions occurring within each of the processes. Optical microscopy and X-ray diffraction (XRD) techniques have been used to characterize fugitive emissions and dusts generated during sintering, smelting, Cu drossing, refining, and slag fuming at a primary Pb-Zn smelter. The results displayed a complex array of phases, with the mineralogy of the dusts and fume reflecting conditions of the particular metallurgical operation. The principal Pb species followed a transformation from PbS through PbSO4 and PbO to Pb(o) (metal) from raw materials to the refinery. The fugitive emissions generated by the blast furnace were of a finer size with more complex chemistry than fugitive material from other source areas. XRD identified a mixture of PbS, ZnO, and ZnS, associated with one or more of the Cl-bearing phases Pb(OH)Cl, PbCl2, Pb4O3Cl2, Na3Pb2(SO4)3Cl, Pb10(SO4)Cl2O8, Pb4SCl6, and Pb7S2Cl10. The presence of Cl-bearing phases in the fume has possible health implications.

Air Pollution↗