Prevalence of alcohol problems in general practice: an experience from southern Italy

The Michigan Alcoholism Screening Test (MAST) and the response to a question about heavy alcohol consumption were used to assess the prevalence of alcohol problems in consecutive patients (77 males and 46 females) consulting a general practitioner in an urban area in the South of Italy (Castellammare di Stabia). Alcohol problems, which were defined by a cut-off score of 5 on the MAST and/or by heavy alcohol consumption (corresponding to at least 60 g of ethanol daily for males and 36 g of ethanol daily for females for at least 2 years), were identified in 54 patients [43.9%; 95% confidence interval (CI) 35.0-53.1%], 45 males (58.4%; 95% CI 46.6-69.6%) and nine females (19.6%; 95% CI 9.4-33.9%). The prevalence of MAST positive patients was 32.5% (95% CI 24.4-41.6%) in the total patient sample, 45.5% (95% CI 34.1-57.2%) among males and 10.9% (95% CI 3.6-23.6%) among females. The question about heavy alcohol consumption had a predictive negative value of 97.2% (95% CI 90.2-99.7%) and a predictive positive value of 73.1% (95% CI 59.0-84.4%) in relation to MAST positive patients. It is suggested that general practitioners should incorporate this question about heavy alcohol consumption as a screening question in order to detect alcohol problems and give advice regarding reduction of alcohol consumption.

The natural history of monoclonal villous lymphocytosis: a chronic lymphoproliferative disorder of CD11c+ B cells

The long-term outcome of three asymptomatic subjects with isolated persistent lymphocytosis of monoclonal villous B-cells (MVL) is reviewed. After 7.5 years, evolution to a splenic lymphoma variant (SLVL) was documented in only one patient, accompanied by a loss of interleukin-1beta autocrine production, confirming that MVL can be an early form of a malignant disorder. The clinical course was uneventful in the other two cases; a progressive lowering of lymphocyte count being noted in one. While the strict relationship of MVL to SLVL is confirmed, time to progression is unpredictable and the mechanisms by which it occurs still remain to be elucidated.

Expression of A-myb, but not c-myb and B-myb, is restricted to Burkitt's lymphoma, sIg+ B-acute lymphoblastic leukemia, and a subset of chronic lymphocytic leukemias

The A-myb gene encodes a transcription factor that is related both functionally and structurally to the v-myb oncogene. Following our observations that A-myb is expressed in a restricted subset of normal mature human B lymphocytes, with the phenotype CD38+, CD39-, slgM-, we have now investigated the pattern of A-myb expression in neoplastic B cells representating the whole spectrum of B-cell differentiation and compared it to that of c-myb and B-myb. In a panel of 32 B-cell lines, A-myb was very strongly expressed in most Burkitt's lymphoma (BL) cell lines, but weak or negative in 2 pre-B acute lymphoblastic leukemia (ALL), 4 non-Hodgkin's lymphoma (NHL), 6 Epstein-Barr virus-immortalized lymphoblastoid cell lines, and 6 myeloma lines. Protein expression paralleled that of the RNA. We have also investigated A-myb expression in 49 fresh cases of B leukemias. Among 24 ALL, 6 were of the null and 11 of the common type and all these were negative for A-myb expression; on the other hand, all 7 B-ALL cases (slg+), as well as one fresh BL case with bone marrow infiltration, expressed A-myb. A-myb was undetectable in 4 prolymphocytic leukemias (PLL) but was strongly expressed in 5/20 (25%) of chronic lymphocytic leukemia (CLL) samples. In the latter A-myb did not correlate with phenotype or clinical stage. Finally, we have studied the progression of one case of CLL into Richter's syndrome and have found that the Richter's cells expressed about 25-fold less A-myb RNA than the CLL cells from the same patient. The pattern of c-myb and B-myb was clearly distinct from that of A-myb. C-myb and B-myb were expressed in all neoplastic groups, except in CLL cells. Thus, A-myb expression, unlike that of c-myb and B-myb, is restricted to a subset of B-cell neoplasias (in particular BL and slg+B-ALL) representative of a specific stage of B-cell differentiation. This expression may in part reflect expression of A-myb by the normal germinal center B cells that are the normal counterpart of these transformed B cells. The data presented strongly support a role for this transcription factor in B-cell differentiation and perhaps in B-cell transformation in some neoplasias.

AM580, a stable benzoic derivative of retinoic acid, has powerful and selective cyto-differentiating effects on acute promyelocytic leukemia cells

All-trans retinoic acid (ATRA) is successfully used in the cyto-differentiating treatment of acute promyelocytic leukemia (APL). Paradoxically, APL cells express PML-RAR, an aberrant form of the retinoic acid receptor type alpha (RAR alpha) derived from the leukemia-specific t(15;17) chromosomal translocation. We show here that AM580, a stable retinobenzoic derivative originally synthesized as a RAR alpha agonist, is a powerful inducer of granulocytic maturation in NB4, an APL-derived cell line, and in freshly isolated APL blasts. After treatment of APL cells with AM580 either alone or in combination with granulocyte colony-stimulating factor (G-CSF), the compound induces granulocytic maturation, as assessed by determination of the levels of leukocyte alkaline phosphatase, CD11b, CD33, and G-CSF receptor mRNA, at concentrations that are 10- to 100-fold lower than those of ATRA necessary to produce similar effects. By contrast, AM580 is not effective as ATRA in modulating the expression of these differentiation markers in the HL-60 cell line and in freshly isolated granulocytes obtained from the peripheral blood of chronic myelogenous leukemia patients during the stable phase of the disease. In NB4 cells, two other synthetic nonselective RAR ligands are capable of inducing LAP as much as AM580, whereas RAR beta- or RAR gamma-specific ligands are totally ineffective. These results show that AM580 is more powerful than ATRA in modulating the expression of differentiation antigens only in cells in which PML-RAR is present. Binding experiments, using COS-7 cells transiently transfected with PML-RAR and the normal RAR alpha, show that AM580 has a lower affinity than ATRA for both receptors. However, in the presence of PML-RAR, the synthetic retinoid is a much better transactivator of retinoic acid-responsive element-containing promoters than the natural retinoid, whereas, in the presence of RAR alpha, AM580 and ATRA have similar activity. This may explain the strong cyto-differentiating potential of AM580 in PML-RAR-containing leukemic cells.

Role of anthracyclines in the treatment of adult acute lymphoblastic leukemia

In acute myelogenous leukemia, early treatment is usually attempted with the so-called 3+7 regimen, employing daunorubicin (DNR) or idarubicin (IDR) for 3 consecutive days. In acute lymphoblastic leukemia (ALL), the role of agreement regarding ANT dosage and schedule, preferable compound, and indications for remission induction and consolidation treatment phases. Here we review the role of these drugs in adult ALL. The results indicate that ANTs may offer the best survival chance when used at full dosage during induction and early consolidation treatment. IDR may be a better choice that DNR or doxorubicin, and CD10+ t(9;22)/bcr- ALL may have an excellent prognosis following an early dose-intensive ANT consolidation program.

Resistance to aminoglycosides and other antibiotics among clinical isolates of Enterococcus spp

We conducted a study on 81 clinical isolates of enterococci (65 Enterococcus faecalis and 16 Enterococcus faecium) collected consecutively over a one year period at our University Hospital. Of them, 10 (15%) Enterococcus faecalis and 6 (38%) Enterococcus faecium showed high level resistance to aminoglycosides, were all acquired in surgical units and in five cases they were responsible for invasive infections. Ampicillin and imipenem were active only against Enterococcus faecalis. Vancomycin and teicoplanin were bacteriostatic; however, teicoplanin MICs were lower and in 45% of cases its MBC values were within clinically achievable serum concentrations. Ciprofloxacin and cotrimoxazole were active in vitro.

Identification of chromosomal rearrangements in the human myeloid leukemia cell line GF-D8 by dual-colour fluorescence in situ hybridization

Fluorescence In Situ Hybridization (FISH) studies with chromosome-specific libraries and repetitive probes were performed on the human acute myeloid leukemia cell line GF-D8 in order to define the complex chromosomal rearrangements observed by conventional cytogenetic analysis. Two-colour FISH with whole chromosome painting probes 8 and 11 showed that the add(8) chromosome had an 11-derived region inserted at q24, whereas the add(11) chromosome had an 8-derived region translocated onto q23. It also demonstrated that no normal chromosome 11 is present in GF-D8 cells, since a translocation involving chromosomes 11 and 17q was detected in addition to the add(11). The der(7) chromosome with extra material in its long arm, identified by QFQ and GTG banding, turned out to have a chromosome 15-derived segment translocated to q22. The deletion of 7q was proved to be interstitial, as the 7q-specific telomere as well as a tiny 7-specific band were observed on an unknown chromosome. Fine mapping of the breakpoints involved in the multiple chromosomal rearrangements of the GF-D8 cell line might provide insights into the mechanisms of myeloid leukaemogenesis.

Constitutive expression of GATA-1, EPOR, alpha-globin, and gamma-globin genes in myeloid clonogenic cells from juvenile chronic myelocytic leukemia

Juvenile chronic myelocytic leukemia (JCML) is a rare disorder of early childhood. Characteristic of JCML are the progressive appearance of high levels of fetal hemoglobin (HbF), reflecting a true reversion to a fetal type of erythropoiesis, and the presence of colony-forming cells able to grow in vitro spontaneously in the absence of growth factors. To better understand the relationship between the erythroid abnormalities and the leukemic process, we analyzed the expression pattern of specific genes related to erythroid differentiation--GATA-1, EPOR, alpha-globin, beta-globin, and gamma-globin genes--in JCML peripheral blood (PB) cells and in vitro-derived colonies. Northern blot analysis of PB cells from five JCML patients indicated levels of GATA-1 transcripts much higher than those usually found in other types of leukemic cells, and S1 nuclease protection assay detected significantly increased expression of gamma-globin mRNA. Reverse transcription-polymerase chain reaction (RT-PCR) analysis of single granulocyte-macrophage colony-forming unit (CFU-GM) colonies, obtained in vitro in the absence of added growth factors from four JCML patients, detected GATA-1, EPOR, and globin (alpha and gamma) transcripts in most of the colonies tested, in contrast with control CFU-GM from normal bone marrow, which were positive only for GATA-1. Single JCML colonies were tested for the presence of two different transcripts; whereas alpha- and gamma-globin genes appeared mostly coexpressed, beta-globin mRNA was detected only in a minority of the gamma-globin-positive colonies, indicating that the leukemic pattern of hemoglobin synthesis is mainly fetal. In addition, the leukemic cells occurring during blast crisis of one of our patients displayed the typical features of a stem cell leukemia (CD34+, CD19-, CD2-, myeloperoxidase-). In this sorted CD34+ population, we detected the presence of a marker chromosome, der(12)t(3;12), previously identified in bone marrow cells at diagnosis and an expression pattern superimposable to that of the JCML colonies, consistently displaying a high gamma-globin:beta-globin mRNA ratio. The expression of erythroid markers within populations of leukemic cells, both in vivo and in vitro, supports the hypothesis that abnormal JCML erythroid cells may originate from the same mutated progenitor that sustains the growth of the leukemic cells.

Prevalence of alcohol problems among adult somatic in-patients in Naples

The aim of this cross-sectional study was to determine the prevalence of alcohol problems among adult somatic in-patients in urban hospitals of Naples. The patients were screened with a structured questionnaire regarding life style. After discharge, the patient records were examined and the hospital discharge diagnoses were registered. A patient was considered having an alcohol problem if one or more of the following criteria were fulfilled: (1) a Michigan Alcoholism Screening Test score at or above five; (2) a self-reported daily consumption for at least 2 years of at least 60 g of ethanol for males and 36 g for females; (3) an alcohol-related discharge diagnosis. The prevalence of patients with alcohol problems was significantly (P < 0.01) higher among male (43.8%, 95% confidence limits, 37.6-50.2%) than among female patients (14.8%, 95% confidence limits, 9.6-21.4%). There were no significant differences among the different types of somatic departments regarding the prevalence of alcohol problems when gender was considered. Patients with alcohol problems differed significantly from those without alcohol problems regarding a number of variables: the former drank significantly more alcohol, smoked for more years, and had a higher prevalence of alcohol problems in the family. It is concluded that alcohol problems among in-patients are as prevalent in Naples as in other industrialized countries, that it is often not registered among discharge diagnoses, and that the problems are more prevalent in males than in females, irrespective of the type of department.

All-trans retinoic acid and cyclic adenosine monophosphate cooperate in the expression of leukocyte alkaline phosphatase in acute promyelocytic leukemia cells

Treatment of acute promyelocytic leukemia (APL) blasts with cyclic adenosine monophosphate (cAMP) analogs, in combination with all-trans retinoic acid (ATRA), results in the upregulation of the expression of leukocyte alkaline phosphatase (LAP), a marker for the differentiation of the granulocyte. The synergistic interaction between the cyclic nucleotide analogs and the retinoid is not unique to APL cells, as it is observed also in the peripheral granulocytes of chronic myelogenous leukemia (CML) patients. The molecular mechanisms underlying LAP induction were studied in NB4, an immortalized APL cell line. Induction of LAP enzymatic activity is dependent on the time of exposure and on the concentrations of dibutyryl-cAMP or 8-bromo-cAMP and ATRA, two factors that influence the kinetics of appearance of detectable levels of the enzyme. Augmentation of LAP levels by ATRA and cAMP is the result of both transcriptional and early posttranscriptional events and requires de novo protein synthesis. LAP induction correlates with augmentation in the levels of the type I catalytic subunit of cAMP-dependent protein kinase transcript and with granulocytic differentiation. The transcriptional component of the process leading to increased LAP gene expression was reproduced in its main features by transient transfection experiments performed in COS-7 cells using the normal retinoic acid receptor type alpha (RAR-alpha) or the APL-specific aberrant form (PML-RAR) and the upstream promoter of the liver/bone/kidney (L/B/K)-type alkaline phosphatase gene. The promoter is upregulated by treatment with ATRA, and this upregulation is further increased by cAMP analogs.

Autologous PBSC transplant for late onset AML after mafosfamide-purged and TBI-containing autologous BMT

The prognosis of AML patients who fail autologous BMT and lack a donor for a salvage allogeneic BMT is very poor. We administered an alternative drug treatment including autologous PBSC transplant to a child who relapsed with AML 4 years after a mafosfamide-purged and TBI-containing BMT for second remission AML. Treatment comprised induction-consolidation with 'short' ICE courses (idarubicin-Ara C-etoposide for 2 days), high-dose CY plus G-CSF with collection of CD34+ PBSC and myeloablative treatment with high-dose mitoxantrone/BEAM supported by autologous PBSC reinfusion. The outcome was complete response, lasting 24 months. The patient died in remission of drug-related cardiotoxicity. This report emphasizes the possibility of a secondary AML after mafosfamide-purge autologous BMT, and documents the feasibility of an autologous PBSC transplant in such a high risk setting.

The use of anthracyclines in adult acute lymphoblastic leukemia

A critical review of the role of anthracyclines in the management of adult patients with acute lymphoblastic leukemia was performed to define current indications for their use. Major pertinent clinical series were reviewed with reference to anthracycline type, cumulative dosage and dose intensity, and administration schedule during both induction therapy and postremission consolidation, comparing results, whenever possible, with non-anthracycline treatment groups. A subgroup analysis was performed to evidentiate disease subtypes likely associated with a favorable outcome to anthracycline treatment. The results indicated that anthracyclines may still play a primary role in this setting. In particular, anthracyclines should be used at full therapeutic doses, especially during induction and early consolidation; idarubicin could be a better choice than daunorubicin or adriamycin; finally, an early brief intensive treatment with anthracyclines may provide an excellent probability of long-term disease-free survival in CD10+ t(9;22)-negative B-precursor adult ALL, obviating the need for prolonged maintenance or late reinduction therapy.

Visceral leishmaniasis during pregnancy treated with meglumine antimoniate

Data on the efficacy and safety of pentavalent antimony in the treatment of visceral leishmaniasis during pregnancy are scanty. A case of visceral leishmaniasis in a 39-year-old woman in the second trimester of pregnancy is reported here. The patient was hospitalized in poor condition with high fever and pancytopenia which had lasted for 6 weeks. A bone marrow aspirate revealed numerous amastigotes and serodiagnosis for Leishmania was positive at a high titer. The patient was successfully treated with meglumine antimoniate at a daily dose of 850 mg of antimony for 20 days. She delivered at term a healthy female baby who remains in good condition at 18 months of age. Thus a dose of 850 mg of antimony, which is lower than that presently recommended, seems to be effective and non toxic to the fetus when administered at the second trimester of pregnancy.

Effects of dexamethasone on pro-inflammatory cytokine expression, cell growth and maturation during granulocytic differentiation of acute promyelocytic leukemia cells

In basal conditions, NB4 and HL-60, two acute promyelocytic leukemia cell lines, express high levels of tumor necrosis factor (TNF-alpha) mRNA, whereas they do not synthesize appreciable amounts of the transcripts coding for interleukin-1 beta (IL-1 beta) or interleukin-8 (IL-8). Upon granulocytic differentiation with all-trans retinoic acid (ATRA) or the combination of ATRA and granulocyte-colony-stimulating factor (G-CSF), significant amounts of IL-1 beta and IL-8 mRNAs accumulated in both cell types. These changes in mRNA levels were parallelled by the increased secretion of the two cytokines. Dexamethasone (DEX) had no effect on the induction of IL-1 beta mRNA, while it enhanced the G-CSF-, ATRA- and (ATRA+G-CSF) dependent secretion of the cytokine. In combination with ATRA and G-CSF, the corticosteroid increased the expression of leukocyte alkaline phosphatase, a late marker of granulocytic differentiation.

Granulocyte colony-stimulating factor following peripheral-blood progenitor-cell transplant in non-Hodgkin's lymphoma

PURPOSE

To compare the hematologic recovery after high-dose chemotherapy and circulating peripheral-blood progenitor-cell (PBPC) transplant between patients who received recombinant human granulocyte colony-stimulating factor (G-CSF) (treated group) and those who did not (control group).

PATIENTS AND METHODS

From December 1992 through June 1994, two sequential and consecutive cohorts of 20 patients each with histologically proven non-Hodgkin's lymphoma (NHL) received high-dose chemotherapy (carmustine [BCNU], cytarabine [Ara-C], etoposide and melphalan [BEAM]) followed by PBPC transplant. The first 20 patients were treated with G-CSF (5 micrograms/kg/d) after PBPC administration. Since the time of platelet and leukocyte recovery in this group was short (< 15 days), with a narrow standard deviation from the mean value, the last 20 patients were not given G-CSF. Hematologic recovery, number of febrile days, rate of documented infections, number of hospital days, duration of gastrointestinal complications, platelet and RBC transfusions, and antibiotic requirements were compared in the two groups.

RESULTS

The two groups of patients were comparable according to disease status, histology, stage, bulky disease bone marrow involvement, elevated lactate dehydrogenase (LDH) level, and median number of infused CD34+ cells and colony-forming units granulocyte-macrophage (CFU-GM). The median time to reach 0.5 x 10(9)/L and 1.0 x 10(9)/L neutrophils was 2 days shorter in G-CSF group, but this difference was not statistically significant. The median times to reach 20 x 10(9)/L and 50 x 10(9)/L platelets were, respectively, 10 and 14 days in the G-CSF group and 11 and 16 days in the control group, but again this was not statistically significant. Moreover, when considering clinically relevant end points including the number of documented infections and antibiotic requirements, platelet transfusions, gastrointestinal toxicity, and days of hospitalization, no differences were demonstrated between the two groups.

CONCLUSIONS

Provided an optimal dose of circulating progenitors is infused, NHL patients transplanted with PBPC do not benefit by the administration of hematopoietic growth factors.

Tyrosine kinases but not cAMP-dependent protein kinase mediate the induction of leukocyte alkaline phosphatase by granulocyte-colony-stimulating factor and retinoic acid in acute promyelocytic leukemia cells

Leukocyte alkaline phosphatase (LAP) is synergistically induced by the combination of all-trans retinoic acid (ATRA) and granulocyte-colony-stimulating factor (G-CSF) in acute promyelocytic leukemia (APL) cells (Gianni' M. et al., Blood 83: 1909-1921, 1994). The role of cAMP and tyrosine kinases in the induction of LAP was investigated. In the APL cell line NB4, adenosine-3': 5'-monophosphothioate, cyclic, Rp isomer, a reversible inhibitor of cAMP-dependent protein kinase (PKA), has no effect on the induction of LAP enzymatic activity and mRNA triggered by ATRA+G-CSF, in conditions where this compound completely blocks the upregulation of LAP transcript caused by the combination of the PKA agonist, dibutyryl-cAMP (db-cAMP), and ATRA. Challenge of NB4 cells with G-CSF, dbcAMP and ATRA causes a much higher induction of LAP relative to that observed in the presence of ATRA+G-CSF or ATRA+dbcAMP. Treatment of NB4 with ATRA and G-CSF results in increases in the tyrosine phosphorylation of several proteins. In the presence of the cytokine and the retinoid, tyrosine kinase inhibitors decrease LAP enzymatic activity and mRNA.

Adult polyomyositis/dermatomyositis associated with acute myeloid leukemia. A case report

Reports of PM/DM associated with haematologic disorders are rare. We describe a 62-year-old man suffering from PM/DM who developed acute myeloid leukemia. The possible paraneoplastic nature of PM/DM in this patient is discussed.

Short-term treatment for adult hypergranular and microgranular acute promyelocytic leukemia

A high hemorrhagic risk and a complete response to the differentiative agent all-trans-retinoic acid (ATRA) are the main clinical features of acute promyelocytic leukemia (APL), two distinct subtypes of which have been recognized, the common hypergranular leukopenic form (M3) and a microgranular hyperleukocytic variant (M3v). We analyzed, with emphasis on both disease- and therapy-related prognostic factors, the results from a 9-year trial in 65 adults with M3 and M3v APL, treated homogenously with a short-term therapy (STT) program excluding maintenance. STT comprised a maximum of six courses with doxorubicin, cytosine arabinoside (ara-C), and 6-thioguanine. Sixty-five APL patients formed the study group, M3v accounting for 25% of cases. In M3v, the absolute blast cell count was significantly higher (p < 0.0001) and early hemorrhagic deaths were more frequent (p = 0.05). The blast count correlated inversely with the probability of remission (p = 0.005), poor-risk patients being those with > 10 x 10(9)/l blast cells. During the study, the median survival improved from 0.1 to 2.7 years (p = < 0.005). In first place, response to chemotherapy increased from 42 to 84% (p = 0.006), by giving daily prophylactic platelet transfusions (to > 30 x 10(9)/l) and no heparin (course I), and by avoiding too toxic high-dose ara-C and deferring treatment in infected/neutropenic patients showing the atypical differentiative bone marrow pattern (course II). Secondly, the probability of first unmaintained remission differed significantly between patients given intentionally more than four total chemotherapy courses or intermediate/high-dose ara-C consolidation (0.59 at 5 years) and those treated less intensively (0.21) (p < 0.005). Intensive STT was very effective for the management of adult APL patients at standard hemorrhagic risk and receiving optimal supportive care. In high-risk patients with hyperleukocytosis and M3v, induction results could be improved by the concomitant use of ATRA. M3v in adults must be recognized promptly because of the very high early hemorrhagic risk.

Unexpected remission of acute myeloid leukaemia after GM-CSF

The administration of granulocyte-monocyte colony-stimulating factor (GM-CSF) was associated with complete clinical and haematological response in an adult patient with minimally differentiated acute myeloid leukaemia who presented with pneumonia and moderate neutropenia, but no blast cells in the peripheral blood. The response lasted 9 months. At relapse, a second GM-CSF course resulted in a very good partial remission lasting 5 months, although differences in the kinetics of haemoglobin, neutrophil and platelet recovery were noted. Subsequent recurrences were managed with chemotherapy, a complete remission being obtained twice more and lastly consolidated with myeloablative chemo-radiotherapy supported by a peripheral blood stem cell autograft. This report suggests that GM-CSF should be further investigated as a therapeutic agent in selected cases of AML.

Polymerase chain reaction (PCR) approach for the evaluation of minimal residual disease in acute leukemia

Evaluation of minimal residual disease (MRD) in different forms of acute leukemias is an expanding field of experimental hematology. Several strategies and techniques, including cytomorphology, immunophenotype and karyotype, have been applied to evaluate MRD, but molecular biology has provided more sensitive and accurate tools to detect the neoplastic clones. This concise review summarizes some of the technical aspects and pitfalls associated with different molecular approaches such as the analysis of clonospecific DNA sequences in lymphoid malignancies and the demonstration of chimeric genomic products generated by chromosomal translocations. The feasibility, specificity and clinical relevance of all these studies will be briefly discussed.

Determination of orally administered all-trans-retinoic acid in human plasma by high-performance liquid chromatography

All-trans-retinoic acid (RA) is used successfully in the treatment of acute promyelocytic leukaemia (APL), although unexplained relapses occur in many of the patients. Pharmacokinetic studies may help in understanding the mechanism of resistance to RA and a simple and rapid procedure for its determination in biological samples may be advantageous. A high-performance liquid chromatographic procedure is described, involving one-step extraction of RA from plasma, isocratic elution from a reversed-phase column (LiChrosorb RP-18, 5-microns particle size) and UV detection at 340 nm. The calibration graph is linear over a wide range and the limit of detection is approximately 10 ng/ml, using 0.5 ml of human plasma. The method is selective for RA, accurate and robust and thus suitable for the routine analysis of plasma samples from patients undergoing RA therapy. Analysis of plasma in a patient on RA therapy (45 mg/m2 per day) confirmed that during continuous treatment with RA the drug plasma concentrations are markedly lower at the time of relapse than on the first day of treatment.

Expression of GATA-1 mRNA in human myeloid leukemic cells

Expression of the transcription factor GATA-1, which regulates several erythroid specific genes and possibly also some megakaryocytic genes, has been previously detected in normal erythroblasts, megakaryocytes, and basophils, and in some myeloid cell lines. It has been suggested that GATA-1 may be first expressed in a common progenitor and then further activated during erythroid-megakaryocytic and basophilic differentiation and repressed during myeloid maturation. We investigated GATA-1 mRNA expression in highly purified leukemic blasts representing different lineages and stages of myeloid differentiation and in a recently established leukemic cell line, GF-D8, which exhibits morphological, cytochemical and immunophenotypic characteristics of early myeloid progenitor cells. We found GATA-1 expression in five of five myeloid and in one megakaryocytic blast crisis of CML, in four of six cases of myelomonocytic leukemias (M4 according to FAB classification), in one case of erythroleukemia (M6), whereas lymphoid blast crisis of CML and all other FAB groups were completely negative. In addition, a low level of GATA-1 mRNA was also expressed by the GF-D8 cell line. These data further support the hypothesis that GATA-1 expression may occur not only in erythroid and megakaryocytic progenitors, but also in early myeloid progenitors, and then be further regulated during lineage-specific maturation.

Retinoic acid and granulocyte colony-stimulating factor synergistically induce leukocyte alkaline phosphatase in acute promyelocytic leukemia cells

In this report we show a strong synergistic interaction between granulocyte colony-stimulating factor (G-CSF) and all-trans retinoic acid (ATRA) on the expression of leukocyte alkaline phosphatase (LAP) in freshly isolated acute promyelocytic leukemia (APL) blasts as well as in NB40 and HL-60 cell lines. The strong synergism observed in these cell types was not evident in two acute leukemia cell lines (K562 and GF-D8), in normal granulocytes, and in monocytes. In freshly isolated leukocytes derived from chronic myelogenous leukemia (CML), in the stable phase of the disease, a weaker interaction between ATRA and G-CSF was documented. The cross-talk between the cytokine and the retinoid was studied in detail in NB4, an immortalized APL leukemia cell line, retaining the 15-17 chromosomal translocation involving the retinoic acid receptor type alpha. The treatment of NB4 cells with G-CSF alone or ATRA alone leads to no increase and to minor induction in LAP activity, respectively. If the cells are treated with the two compounds simultaneously, a dramatic elevation of LAP is observed after 4 days. The synergism between G-CSF and ATRA is evident at concentrations of the retinoid between 10(-7) and 10(-5) mol/L and at concentrations of the cytokine between 1 and 10 ng/mL. The simultaneous presence of the two compounds is necessary to obtain maximal increase of LAP activity and the effect is cell density-dependent. Synergism is specific for G-CSF, and it is not observed with other cytokines and functional inducers of the granulocyte. The augmentation of LAP activity is the consequence of an increased transcriptional rate of the liver/bone/kidney-type (L/B/K-type) alkaline phosphatase gene, as determined by Northern blotting and nuclear run-on analysis using specific cDNA probes. Only one of the two possible alternatively spliced forms of L/B/K-type alkaline phosphatase transcript is detected in NB4 cells after stimulation with G-CSF and ATRA. This mRNA form, which is the one observed in normal polymorphonuclear leukocytes, contains the most upstream leader exon. In NB4 cells, ATRA induces G-CSF, alpha, and beta retinoic acid receptor transcripts, whereas G-CSF has minor effects on the expression of these mRNAs.

Dissociation between p93B-myb and p75c-myb expression during the proliferation and differentiation of human myeloid cell lines

Direct and indirect evidence strongly indicates that the proto-oncogene c-myb plays an important role in the regulation of both the proliferation and differentiation of hematopoietic cells. In addition, recent data suggest that the structurally related B-myb gene is also necessary for the proliferation of these cells. To help understand the relationship between these two related gene products during proliferation and differentiation of myeloid cells, we have studied in parallel the regulated expression of c-myb and B-myb RNAs and proteins in human myeloid cells that were either growth-arrested or induced to differentiate along different pathways. For this purpose, we have produced a polyclonal antibody directed against a fragment of the recombinant B-myb protein. We have thus been able to detect the B-myb protein in human cell lines and have found it to be a 93-kD protein localized in the nucleus. We have chosen two models to study the expression of both c-myb and B-myb mRNAs and proteins during myeloid proliferation and differentiation. One of the models was the HL-60 cell line, which can be induced to differentiate towards the monocytic pathway with either phorbol ester (phorbol myristate acetate) or vitamin D3 and towards the granulocytic pathway with either dimethyl sulfoxide or retinoic acid. In addition, we have studied another recently established human leukemic cell line, called GF-D8, which is strictly dependent on granulocyte-macrophage colony-stimulating factor (GM-CSF) for proliferation. The results show that the expression of B-myb RNA and protein closely correlates with proliferation in all experimental setups studied, whereas the c-myb protein levels do not always do so. We observed that the c-myb protein levels decreased well before the decrease of B-myb protein and of proliferation itself during differentiation toward monocytes. Such a difference was not present during granulocytic differentiation, in which c-myb levels decreased, if anything, later than those of B-myb and proliferation. Most striking was the finding that high levels of c-myb RNA and protein, but not of B-myb, were present in the GF-D8 cell line, even after growth arrest by GM-CSF deprivation. These data suggest that B-myb may function solely in the regulation of cellular proliferation, whereas c-myb has additional functions, for example, in the maintenance of an undifferentiated state.