Biomedical subjects

E F Winton

Publications and source records attributed to E F Winton.

At least 37 records · Page 2Linked to original sources

PubMed1993

CD34+ and CFU-GM progenitors are significantly decreased in SIVsmm9 infected rhesus macaques with minimal evidence of direct viral infection by polymerase chain reaction.

Hematologic abnormalities in the peripheral blood and bone marrow are associated with human immunodeficiency and simian immunodeficiency virus (HIV, SIV) infection. The reasons for these abnormalities remain unclear. Bone marrow specimens collected from uninfected animals (Group A, Controls) and from rhesus macaques experimentally infected with SIVsmm9 during the asymptomatic stage (Group B, SIV+ "well") and during the clinically ill stage (Group C, SIV+ "sick"), underwent a variety of in vitro assays of hematopoiesis. Colony forming unit-granulocyte/macrophage (CFU-GM) per plate growth was 46.7 +/- 7.7, 31.9 +/- 8.4 and 6.5 +/- 5.0 (mean +/- sd, P < .02 each mean compared to the others) in the 3 groups respectively. Burst forming unit-erythroid (BFU-E) growth was similarly decreased in bone marrow samples from the SIV+ animals. There was no change in the number of CFU-GM per plate with the removal of plastic adherent or T-cell mononuclear cell fractions. There was no increase in CFU-GM per plate growth with the addition of low dose GM-CSF (1 or 5 ng/mL) though there was a near 67% increase (48 to 80 CFU-GM per plate) with the addition of 100 ng/mL recombinant rhesus IL-3 and 100 ng/mL GM-CSF in SIV+ "sick" animals. Variation in frequency of CD34+ progenitor cells in SIV+ animals was seen, with 3.0% CD34+ cells in SIV- controls, 4.9% CD34+ cells in SIV+ "well" animals and 0.5% CD34+ progenitor cells in SIV+ "sick" monkeys (P < .01, each mean compared to the others). Finally, there was minimal evidence of SIV sequences by polymerase chain reaction in pooled cultured CFU-GM, and no evidence in flowcytometrically sorted CD34+ progenitor cells from selected animals. Thus, the SIV seropositive rhesus monkey appears to have similar hematopoietic aberrations as are found in HIV infected human subjects and may be an excellent model for studying the interaction of lentiviruses on the kinetics of blood formation.

Animals↗

PubMed1993

Peripheral blood stem cell acquisition by large-volume leukapheresis in growth factor-stimulated and unstimulated rhesus monkeys: development of an animal model.

Twelve (eight unstimulated [UNS], four growth factor-stimulated [ST]) anesthetized adult male rhesus monkeys underwent a single large-volume leukapheresis (> 3 blood volumes processed) in an attempt to define an animal model for use in future peripheral blood stem cell (PBSC) transplantation studies. The cell separator was primed with autologous blood and saline and set according to the manufacturer's mononuclear cell (MNC) protocol using the granulocyte separation and small volume collection chambers with additional modifications. Stimulated animals received 5 micrograms/kg recombinant human interleukin-3 (rhIL-3) on days -12 to -5, 5 micrograms/kg granulocyte-macrophage colony-stimulating factor (GM-CSF) on days -4 to -1, and large-volume leukapheresis on day 0. UNS animals did not receive growth factors. Vascular access was via a triple lumen intra-aortic catheter; blood pressure was monitored via the third lumen. Pre- and post-apheresis blood counts were determined and product hematocrit (Hct), MNC, colony-forming units-granulocyte/macrophage (CFU-GM), CD34+, and lymphocyte subsets were studied. During the 100-minute large-volume leukapheresis with mean flow rate 26.4 +/- 3.9 mL/min, the pre- and post-Hct were 36.6 +/- 2.6 and 32.3 +/- 7.0%, platelets 447 +/- 305 and 154 +/- 77 x 10(9)/L, and MNC 2.7 +/- 0.9 and 1.9 +/- 1.4 x 10(9)/L (all p < .05) in UNS animals. In ST animals, the pre- and post-Hct were 39.0 +/- 5.6 and 34.9 +/- 3.7%, platelets 507 +/- 100 and 150 +/- 9 x 10(9)/L (p < .05), and MNC 4.9 +/- 1.6 and 2.8 +/- 0.7 x 10(9)/L (p < .05). The product contained 98.5 +/- 1.4% MNC, 4.1 +/- 4.1% Hct, 1.9 +/- 0.6 x 10(9) MNC, 9.2 +/- 7.3 x 10(4) CFU-GM, and 3.5 +/- 2.1 x 10(6) CD34+ cells in UNS animals. In ST monkeys, the product contained 49.5 +/- 32% MNC, 6.4 +/- 4.4% Hct, 3.6 +/- 1.8 x 10(9) MNC, 49.3 +/- 39 x 10(4) CFU-GM, and 9.1 +/- 5.5 x 10(6) CD34+ cells. Greater than 75% of the product MNC were CD2+ T cells in ST and UNS animals. Large-volume leukapheresis in rhesus monkeys was tolerated well. Herein we characterize an animal model for large-volume leukapheresis in UNS monkeys that is similar to that of human PBSC leukapheresis. In ST animals there is more than a five-fold increase in CFU-GM collected and an increase in circulating CFU-GM/MNC.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗

PubMed1993

Effects of recombinant human granulocyte-macrophage colony-stimulating factor on platelet survival and activation using a nonhuman primate model.

In humans and nonhuman primates, the in vivo administration of recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) consistently results in marked increase of megakaryocyte ploidy and size similar to that observed with interleukin-6 (IL-6). However, whereas the administration of IL-6 also results in an increase in circulating platelets, there is no predictable corresponding increase in peripheral blood platelets following treatment with rhGM-CSF. To determine whether the failure of rhGM-CSF to produce thrombocytosis is secondary to cytokine-related increased platelet activation and consumption in vivo, we quantified autologous platelet survival time and in vivo platelet activation before and during 5 days of administration of rhGM-CSF to two rhesus monkeys. Platelet survival was measured using autologous platelets labeled with 111Indium-oxine. Platelet activation was assessed by flow cytometric determination of the expression of the major platelet membrane glycoprotein (GP) IIb/IIIa complex, and an activation-dependent epitope on GPIIb/IIIa (recognized by monoclonal antibodies [MABs] LJ-P4 and PAC1, respectively). Platelet activation was also assessed by dose-response aggregometry using adenosine diphosphate (ADP). While megakaryocyte ploidy increased during rhGM-CSF administration, peripheral platelet counts were 418 x 10(9)/L and 525 x 10(9)/L before and 402 x 10(9)/L and 508 x 10(9)/L during cytokine treatment in animals 1 and 2, respectively. No changes were observed in the mean platelet volume. 111Indium-labeled platelet recovery in circulation was similar before (94.7%, 91.8%) and during (92.9%, 92.8%) rhGM-CSF administration, which indicates that cytokine-related in vivo sequestration of platelets does not occur. Autologous platelet survival was 5.6 and 6.2 days before and 5.0 and 5.4 days during the rhGM-CSF treatment (p = 0.07), without significant change in the corresponding platelet turnover rate (derived from the platelet count and survival time). The flow cytometric analysis showed no increase in the binding of either LJ-P4 or PAC1 MABs to the platelet membrane during rhGM-CSF administration. The aggregometry studies demonstrated similar concentrations of ADP inducing half-maximal aggregation (ED50). Overall, the above data indicate that treatment with rhGM-CSF is not associated with in vivo activation, sequestration, or increased consumption of platelets. The data suggest that the failure of rhGM-CSF-stimulated megakaryocytes to increase peripheral platelet count is a manifestation of ineffective megakaryocytopoiesis resulting from inability to increase platelet delivery to the circulation.

Animals↗

PubMed1992

Differential effects of sequential, simultaneous, and single agent interleukin-3 and granulocyte-macrophage colony-stimulating factor on megakaryocyte maturation and platelet response in primates.

Recombinant granulocyte-macrophage colony-stimulating factor (GM-CSF) following interleukin-3 (IL-3) priming has been shown to increase thrombopoiesis. To elucidate the comparative abilities of IL-3 and GM-CSF in influencing megakaryocyte development in vivo, serial bone marrow analyses were performed on rhesus monkeys treated with 5 micrograms/kg/d of IL-3 and 5 micrograms/kg/d of GM-CSF sequentially for 4 days each, simultaneously for 8 days, and as single agents for 8 days. Platelet counts maximally increased to a mean of 7.5 x 10(5)/microL (n = 3) on days 11 through 12 in monkeys treated with sequential IL-3/GM-CSF. In contrast, neither IL-3 alone nor simultaneously administered IL-3/GM-CSF elicited increases in thrombopoiesis between days 3 and 15. GM-CSF elicited a variable platelet response. Megakaryocyte ploidy distributions were significantly (P < .001) shifted between days 7 and 10 in monkeys treated sequentially and between days 3 and 15 in monkeys treated with combined IL-3/GM-CSF and with GM-CSF alone but not in monkeys treated with IL-3 alone. The changes in mean DNA content and megakaryocyte size, as determined by digital image analysis, were larger in monkeys treated with sequential IL-3/GM-CSF and with GM-CSF alone than in simultaneously treated monkeys. In addition, sequentially but not simultaneously treated monkeys showed increased numbers of megakaryocytes on bone marrow biopsy. We conclude that administration of IL-3 followed by GM-CSF treatment increases thrombopoiesis by sequentially increasing megakaryocyte numbers and maturation and that these effects are diminished by simultaneous administration of the two cytokines.

Animals↗

PubMed1992

Autologous bone marrow transplantation in acute leukemia with marrow purged with alkyl-lysophospholipid.

Alkyl-lysophospholipids are anticancer agents that are selectively toxic to leukemic cells and relatively sparing of normal bone marrow cells. Thus, they would be likely candidates for purging remission marrows before autologous bone marrow transplant. One of the more promising agents is edelfosine, which could be safely used for purging without prolonging marrow recovery. Assays for marrow progenitor cells were performed before and after purging and cryopreservation in 64 patients. There was no significant reduction in colony formation after purging when compared with unpurged cryopreserved marrow, but there was a significant reduction after cryopreservation. Twenty-four patients with acute leukemia in second (16 patients) or third remission (3 patients), early relapse (3 patients), or in first remission with successfully treated extramedullary relapse (2 patients) received marrow-ablative chemotherapy and total body irradiation followed by infusion of marrow purged for 4 hours with 50 to 100 micrograms/mL of edelfosine. There were 9 lymphoblastic and 15 myelogenous leukemia patients. The median time to granulocyte recovery to 500/microL was 26 and 33 days for the 50 and 75 microgram/mL doses, respectively. The patient whose marrow was purged at the dose of 100 micrograms/mL failed to engraft. The median time to platelet recovery to 25,000/microL was 45 and 37 days for the 50 and 75 micrograms/mL doses, respectively. Twenty-nine percent of the patients remain disease free from 131 to 1,291 days, with a median of 356 days. These results have established that purging with 75 micrograms/mL of edelfosine is a safe dose and is recommended for a phase II trial.

Adolescent↗

PubMed1992

Improved staining method for the simultaneous flow cytofluorometric analysis of DNA content, S-phase fraction, and surface phenotype using single laser instrumentation.

We have developed an improved technique for triple staining that permits the simultaneous flow cytofluorometric analysis of cell surface antigens, bromodeoxyuridine incorporation into DNA, and DNA quantification using 7-amino-actinomycin D. PHA-activated human peripheral blood lymphocytes were incubated with bromodeoxyuridine and stained for cell surface phenotype with phycoerythrin-labeled monoclonal antibodies. Stained cells were fixed serially with 1% paraformaldehyde and 45% ethanol. Fixed cells were sequentially stained with an anti-BrdUrd monoclonal antibody followed by a FITC-conjugated goat anti-mouse antibody and incubated with 7-amino-actinomycin D. Hypotonic buffer was employed for all procedures after fixation. Stained-fixed cells were analyzed by flow cytofluorometry for simultaneous green (525 nm), orange (570 nm), and red (greater than 650 nm) fluorescence. Utilizing this staining technique, we were able to analyze simultaneously cell phenotype, DNA synthesis, and total cellular DNA content with single laser excitation.

Antibodies, Monoclonal↗

PubMed1992

Phase II clinical trial of carboplatin in relapsed and refractory leukemia.

Carboplatin is a second-generation platinum complex drug which has demonstrated activity against a variety of neoplasms including acute leukemia, particularly when given by continuous intravenous (i.v.) infusion. Adults with acute myelogenous leukemia (AML) or acute lymphoblastic leukemia (ALL), either refractory or in first or second relapse, were given a continuous i.v. infusion of carboplatin at a dose of 315 mg/m2 daily for 5 days. A second course was given if the bone marrow at day 14 showed persistent leukemia. If the marrow was hypoplastic, treatment was delayed until marrow recovery was documented. Those with residual leukemia were given a second course. Those achieving complete remission (CR) were given an additional course as consolidation. Of the 46 eligible patients entered (36 AML and 10 ALL) eight achieved CR (17%) of which 6 were AML and 2 ALL. Of nine primary refractory patients, two achieved CR, one AML and one ALL. Excluding the inevaluable patients (protocol violations, patient refused further therapy, early deaths prior to day 14, the CR rate was eight of 28 (29%). All except two CRs required two courses of induction. The non-hematologic toxicity was minimal except for renal and auditory toxicity. Renal toxicity greater than grade 2 was seen in 17 patients and was associated with concomitant use of nephrotoxic antibiotics. In two patients, renal failure was a major factor in the cause of death. Ototoxicity was observed in 11 patients, but was grade 3 in only three. There were 18 deaths during the study. Fourteen died of infection, two died of infection and hemorrhage, one died of hemorrhage while aplastic, and one died of other causes. This trial indicates that carboplatin is an active agent in acute leukemia and warrants further investigation.

Bone Marrow↗

PubMed1992

Studies of an improved rhesus hematopoietic progenitor cell assay.

We have improved Rhesus monkey marrow cell growth in semisolid media by means of substituting supplemented calf serum for fetal bovine serum. The cloning efficiency of light-density marrow cells separated on 60% Percoll was 126 (+/- 54)/10(5) (n = 12, +/- SD), and for light-density peripheral blood cells 60 (+/- 46)/10(6) (n = 11). Thirty-five percent of the colonies were multilineage, whereas the remainder were unilineage colonies composed of erythrocytes, megakaryocytes, and neutrophilic or monocytic granulocytes. Unilineage megakaryocyte colonies comprised 12% of the total marrow progenitor cells. The [3H]TdR suicide index of marrow progenitor cells was 47% +/- 9% (n = 12). This progenitor cell assay should prove useful in preclinical studies of the effect of recombinant hematopoietic growth factors on the number and cycling status of Rhesus hematopoietic progenitor cells.

Animals↗

PubMed1991

Effects of human interleukin-6 on megakaryocyte development and thrombocytopoiesis in primates.

Recombinant human interleukin-6 (IL-6) has previously been shown to increase platelet counts in mice and primates. To elucidate the mechanisms underlying this phenomenon, serial analyses were performed on megakaryocytes obtained from rhesus monkeys treated for 8 days with 30 micrograms/kg/d of recombinant human IL-6. Platelet counts increased to a maximum of 7.8 x 10(5)/microL with biphasic peaks on days 7 and 12 without significant changes in platelet volumes. Large increases in DNA content were seen by two-color flow cytometry and digital image analysis. Ploidy distribution underwent a significant shift between study days 3 and 11 (P less than .0001) with large increases in the frequency of 64N and 128N megakaryocytes. The modal ploidy increased from the normal 16N to 64N. Megakaryocyte size, as measured by area, was increased 2- to 2.7-fold. On day 3, multiple megakaryocytes were seen in endomitosis, along with an abundance of young cells with wide, organelle-free peripheral zones. The giant megakaryocytes seen on days 5 to 7 exhibited marked membrane hyperplasia that occupied much of the cell. Emperipolesis occurred frequently, as did megakaryocyte cell death. No giant platelets were seen. We conclude that IL-6 significantly alters the process of megakaryocyte maturation and thrombocytopoiesis, and that these effects, at least in the doses of IL-6 administered, should not be equated with the physiologic mechanisms operative during accelerated platelet production.

Animals↗

PubMed1991

Recombinant human granulocyte-macrophage colony-stimulating factor promotes megakaryocyte maturation in nonhuman primates.

Megakaryocytes are responsive to several nonlineage-specific cytokines in vitro. In this study, we examined the in vivo effects of recombinant human granulocyte-macrophage colony-stimulating factor (rh GM-CSF) on late stages of megakaryocytopoiesis in the rhesus monkey. Four rhesus monkeys were given 10 micrograms/kg body weight/day of rh GM-CSF s.c. in two divided doses daily for 8 days. Megakaryocyte maturation was evaluated serially by measuring nuclear ploidy and cytoplasmic size. GM-CSF-treated monkeys developed significant shifts in ploidy distribution from days 3 through 15 (p less than or equal to 0.001), with increased frequencies of 64N and 128N megakaryocytes. Mean megakaryocyte size increased 92.5% on day 9, paralleling the increase in DNA content, although megakaryocyte size within ploidy groups did not increase. Megakaryocyte number remained unchanged following rh GM-CSF treatment. The platelet count responses were variable, and mean platelet volume did not change. The present study demonstrates that therapeutic doses of rh GM-CSF stimulate megakaryocyte endomitosis and increase mean size. The data indicate that GM-CSF is effective in promoting the maturation stage of megakaryocyte development but does not result in a consistent thrombopoietic response.

Animals↗

PubMed1990

The ontogeny of a 57-Kd cationic antimicrobial protein of human polymorphonuclear leukocytes: localization to a novel granule population.

The ontogeny of a 57-Kd cationic antimicrobial protein (CAP57) that has substantial similarities to bactericidal permeability increasing protein (BPI) has been determined immunocytochemically. CAP57 was detected in the granules of mature peripheral blood neutrophils. However, it was absent from other cells of the peripheral blood: eosinophils, red blood cells (RBCs), and mononuclear cells. In human bone marrow, CAP57 was confined to the neutrophilic series. The earliest stage of development of the myeloid cells at which CAP57 was demonstrated was the promyelocyte. Double immunofluorescent labeling showed that CAP57 was detected in cells positive for myeloperoxidase. The absence of lactoferrin in certain cells (promyelocytes) containing CAP57 indicated that CAP57 was synthesized and packaged in a population of granules prior to the development of granules that contain lactoferrin. CAP57 could not be demonstrated in HL60 cells either by enzyme-linked immunosorbent assay (ELISA) or by immunocytochemistry. However, the presence of another granule-associated cationic antimicrobial protein of molecular weight 37 Kd (CAP37) was readily detected in undifferentiated HL60 cells. Amino acid sequence analysis showed that CAP57 and BPI were identical. Further indication of the identity between CAP57 and BPI was that monoclonal anti-CAP57 antibodies cross reacted with BPI. Sucrose density-gradient centrifugations showed CAP57 was confined to a granule population that exhibited a buoyant density intermediate of the previously described light and heavy azurophil granules. Further resolution of the individual azurophil granule populations by Percoll density-gradient centrifugation revealed that CAP57 was most concentrated in the density range of 1.093 to 1.100 g/cc. These results strongly suggest the unique finding that CAP57 may be associated with a heretofore unreported granule type.

Amino Acid Sequence↗

PubMed1990

Modulation of retinoic acid-induced differentiation of human leukemia (HL-60) cells by serum factors and sphinganine.

The human cell line HL-60 was used to investigate the role of protein kinase C in the regulation of retinoic acid-induced maturation of promyelocytic leukemia cells by growth and differentiation factors found in serum. Cells grown in serum-containing medium differentiated less than cells in serum-free medium due to several factors, including albumin binding of retinoic acid. Addition of an inhibitor (sphinganine) of protein kinase C, an enzyme that participates in cellular responses to many serum factors, facilitated the retinoic acid-induced differentiation. Cells treated with both retinoic acid and sphinganine produced more superoxide when stimulated by formylmethionylleucylphenylalanine; hence, this combination generated a more functional population of cells. The ability of sphinganine to promote retinoic acid-induced differentiation suggests that retinoic acid therapy might be improved by the concurrent use of a modulator of protein kinase C activity.

Blood Physiological Phenomena↗

PubMed1990

Therapy of acute myelogenous leukemia in patients over the age of 50: a randomized Southeastern Cancer Study Group trial.

In a randomized trial, 299 evaluable patients with acute myelogenous leukemia, age greater than or equal to 51, were initially randomized to cytosine arabinoside, 100 mg/m2/day, by continuous intravenous infusion for seven days, plus either daunorubicin 45 mg/m2/day x 3 (DA), or m-AMSA 200 mg/m2/day x 3 days (MA). Complete remission (CR) rates were not significantly different, 47% for DA and 42% for MA. Toxicities were similar except that severe hepatic toxicity, serum bilirubin greater than or equal to 7 mg/dl, was more frequent in patients receiving MA (10%) than in patients receiving DA (4%), p less than 0.05. Deaths during induction were significantly more frequent in patients receiving MA (38%) than in patients receiving DA (25%), p = 0.018. Patients achieving a CR received thioguanine, cytosine arabinoside, and daunorubicin (TAD) for three cycles as consolidation. Among evaluable patients, 82/102 (80%) stayed in CR during these three cycles. Patients were then randomized to either no maintenance or to DA every 13 weeks x 4 cycles, at a dose slightly lower than used for induction. Remission duration was similar for the two maintenance programs, 10.7 months for no maintenance and 8.5 months for DA. The percentage of patients evaluable for maintenance achieving three year relapse-free survival was similar for the two maintenance programs, 28% for no maintenance and 21% for DA. However, overall survival was significantly greater (40 vs 12 months, p = 0.007) for patients receiving no maintenance therapy, due to greater survival after recurrence in these patients. At each phase of the study there were substantial numbers of non-evaluable cases, often due to incomplete evaluation of remission status. Of the 379 patients initially entered into the trial, 35% obtained a complete remission. Of all the patients who achieved a complete remission, 61% were both evaluable and in remission upon completion of the maintenance phase. Of these patients who completed the maintenance phase in remission, 15% were relapse free survivors three years following initiation of maintenance therapy. Overall, only 3.2% of patients who entered the trial (35% x 61% x 15%) were continuous relapse-free survivors three years into the maintenance phase.

Aged↗

PubMed1990

Ophthalmological and other toxicities related to cytosine arabinoside and total body irradiation as preparative regimen for bone marrow transplantation.

Cytosine arabinoside, 3 g/m2, every 12 h for 6 days, followed by fractionated total body irradiation, 200 cGy twice daily for 3 days, was administered to 39 adult patients undergoing bone marrow transplantation. Allogeneic transplant patients received cyclosporin and methotrexate for prophylaxis of graft-versus-host disease. There were 21 autologous transplants (16 with acute leukemia, four with an advanced stage of chronic myelocytic leukemia, and one with lymphoma) and 18 allogeneic transplants (14 with acute leukemia, two with an advanced stage of chronic myelocytic leukemia and two with myelodysplastic syndrome). Toxicities were compared between the two groups. There was a significantly greater degree and duration of mucositis and a greater frequency of radiation-type retinopathy developing in the allogeneic group, predominantly in those having had radiation for prophylaxis or treatment of central nervous system leukemia. Seven of 11 acute leukemic patients who received autologous transplants in remission survive. Two of seven acute leukemias who received allogeneic transplants while in remission survive. Although the increased morbidity, retinitis and mucositis, observed in the allogeneic group indicates that this regimen when combined with methotrexate and cyclosporin is too toxic, the results in autologous transplantation in acute leukemia in remission are encouraging.

Bone Marrow Transplantation↗

PubMed1989

Granulocyte/macrophage colony-stimulating factor primes human neutrophils for increased diacylglycerol generation in response to chemoattractant.

Pretreatment of human neutrophils with granulocyte macrophage-colony stimulating factor (GM-CSF) augments several biological responses to chemoattractants (e.g. the respiratory burst, degranulation, and chemotaxis). However, little is known regarding the intracellular effects of priming with GM-CSF. In the present study, we have investigated the effects of GM-CSF on the generation of diacylglycerol (DAG), a proposed mediator of neutrophil responses. GM-CSF alone produced only a small increase in cellular DAG mass, which was most apparent after 30 min. GM-CSF pretreatment (60 min), however, caused a striking augmentation in DAG generation in response to the chemoattractant formyl-methionyl-leucyl-phenylalanine (fMLP), compared with neutrophils preincubated without GM-CSF. The augmentation in DAG generation correlated with an enhancement by GM-CSF of superoxide generation in response to fMLP. The data suggest that GM-CSF may exert some of its biological effects by enhancing DAG generation in response to a second agonist.

Chemotaxis, Leukocyte↗

PubMed1989

Differential effects of long-chain (sphingoid) bases on the monocytic differentiation of human leukemia (HL-60) cells induced by phorbol esters, 1 alpha, 25-dihydroxyvitamin D3, or ganglioside GM3.

Conditions were developed to prolong the ability of sphinganine, a potent inhibitor of protein kinase C, to block the phorbol ester-induced adherence of HL-60 cells beyond 24 h. The loss of inhibition after this time seen previously (A.H. Merrill, Jr., A.M. Sereni, V.L. Stevens, Y.A. Hannun, R.M. Bell, and J.M. Kinkade, Jr., J. Biol. Chem., 261: 12610-12615, 1986), which appeared to be due to metabolism of this long-chain base, was overcome by supplying sphinganine daily. After 4 days, phorbol myristate acetate-induced adherence was inhibited approximately 50% by sphinganine. Sphinganine significantly decreased the expression of nonspecific esterase induced by phorbol myristate acetate in the nonadherent cells, indicating that other aspects of maturation besides adherence were blocked. The effects of daily sphinganine treatments on the monocytic differentiation induced by 1 alpha-25-dihydroxyvitamin D3 or ganglioside GM3 were also investigated. The increases in nonspecific esterase expression, nitroblue tetrazolium reduction, and morphological maturation caused by either agent were unaffected by the long-chain base. In addition, the changes in several cell surface antigens caused by 1 alpha,25-dihydroxyvitamin D3 were unaltered by sphinganine. Although phorbol esters, 1 alpha,25-dihydroxyvitamin D3, and ganglioside GM3 all induce the maturation of HL-60 cells along the monocytic lineage, the finding that sphinganine only affected the differentiation initiated by phorbol esters, in which protein kinase C clearly is a major regulator, suggests that this enzyme does not play a major role in these other pathways of differentiation.

Antigens, Neoplasm↗

PubMed1989

High-dose cytosine arabinoside and daunorubicin as primary therapy in elderly patients with acute myelogenous leukemia. A phase I-II study of the Southeastern Cancer Study Group.

We undertook a phase I-II trial in elderly (age greater than or equal to 60 years) untreated acute myelogenous leukemia (AML) patients using brief, intensive therapy to improve induction rates and overall survival in older AML patients. Twenty-one patients ranging in age from 60 to 81 years (median, 66 years) were treated using either a 4- or 5-day course of high-dose cytosine arabinoside, 3 g/m2 intravenously (IV) every 12 hours; followed by daunorubicin, 45 mg/m2/d IV bolus for 3 consecutive days. Thirteen patients were entered at the first dose level (a 4-day course or eight doses of cytosine arabinoside), whereas eight patients underwent therapy at the second dose level (a 5-day course or ten doses). Patients who achieved a complete remission received a repeat course of high-dose cytosine arabinoside and daunorubicin within 4 weeks of attaining remission. Seven patients had an antecedant history of a myelodysplastic syndrome. Infection was the major complication experienced by this elderly patient group, and included ten episodes of bacteremia or fungemia (four of which were fatal) and five cases of pneumonia (one fatality). Nine of the 21 patients (three of 13 at the first dose level and six of eight at the second dose level) achieved a complete remission. Median remission duration was 9 months (range, 4-19+ months). Although high-dose cytosine arabinoside plus daunorubicin was an effective antileukemic therapy, it is too toxic to recommend for most elderly leukemic patients.

Aged↗

PubMed1989

Factors affecting survival in allogeneic bone marrow transplantation.

From 1979 to 1988, 82 allogeneic and 2 syngeneic bone marrow transplants (BMT) were performed in 78 patients (age range 13-49 years) with the following diagnoses: acute myelogenous leukemia (AML) (21 patients); acute lymphoblastic leukemia (ALL) (15 patients); chronic myelocytic leukemia in chronic, accelerated, or blastic phase (CML-CP, AP or BC) (25 patients); myelodysplastic syndrome (MDS) (1 patient); multiple myeloma (MM) (1 patient); Hodgkin's disease (HD) (1 patient); diffuse poorly differentiated lymphoma (DPDL) (1 patient); aplastic anemia (AA) (13 patients). Univariant analyses were carried out to determine factors of importance in predicting outcome. AML patients receiving transplants in remission had 12/19 (63%) survivors. Only one of seven ALL patients receiving transplants in remission survives free of disease, and none of eight patients receiving transplants in relapse survived. Six ALL patients relapsed. In CML, 6 of 16 (40%) patients receiving transplants in CP survive; two of nine patients (22%) in AP or BC survive. Of the 13 aplastic anemias, 8 (62%) survive. Graft-vs.-host disease (GVHD) was evaluated in 75 patients, 24 of 33 (73%) who developed GVHD died, compared to 24 of 44 (55%) who did not develop GVHD. Of the 30 patients given the combination of methotrexate (MTX) plus cyclosporine (CSP), only 23% developed GVHD, compared to 58% of those not given the combination. Interstitial pneumonia (IP) occurred in 16 patients and was fatal in 15. The introduction of daily acyclovir and weekly intravenous gamma globulin in 1985 was associated with little reduction in the frequency of IP (from 20% to 18%). However, survival increased from 21% to 47%.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗