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T Barbui

Publications and source records attributed to T Barbui.

At least 73 records · Page 4Linked to original sources
PubMed1998

Rapid retroviral infection of human haemopoietic cells of different lineages: efficient transfer in fresh T cells.

In order to develop a clinically feasible gene marking approach, we have used the recently described PINCO retroviral expression system, composed of the enhanced green fluorescence protein (EGFP) cDNA driven by Moloney MLV LTR and packaged in the Phoenix amphotropic cell line. Two T, five B, one erythromyeloid and three myeloid cell lines were successfully infected with % GFP+ cells ranging from 4% to 79%, showing a lineage-dependent difference in infection susceptibility, with the myeloid cells being the least efficiently infected. We also infected normal mononuclear peripheral cells cultured in PHA and rhIL-2 for 2 d, and obtained an average of 30% GFP+ cells, all present within the CD3+ population, with CD4+ and CD8+ cells being equally infected. Finally, the tonsillar purified B population showed lower levels of infectivity (6%) whereas high susceptibility was shown by normal human umbilical vein endothelial cells (57%). Highly purified CD34+ cells were also susceptible, varying from 6% to 10% GFP+ cells. Immature myeloid/erythroid progenitors have been infected which stably expressed the GFP protein during further differentiation in culture. The GFP+ T cells were FACS-sorted rapidly upon infection, subsequently cultured and the fluorescence intensity monitored. In all cases the difference in percentage of GFP+ cells did not correlate with the percentage of S/G2/M cycling cells as determined at the moment of infection or with the expression levels of Ram-1 amphotrophic receptor. The improved safety of this retroviral system, the rapidity of the technique, the high efficiency of infection with respect to normal T lymphocytes (in this last case higher than previously reported) and the lack of need for in vitro selection make this system favourable for clinical development.

Antigens, CD34↗
PubMed1998

No treatment for low-risk thrombocythaemia: results from a prospective study.

Essential thrombocythaemia (ET) is a chronic myeloproliferative disorder characterized by the occurrence of thromboembolic episodes, particularly in patients aged > 60 years or with a previous history of thrombosis, and/or by haemorrhages in patients with an exceedingly high platelet count. In these subgroups of patients the use of cytoreductive therapy is beneficial in terms of risk/benefit ratio. Only limited anecdotal data are available on the thrombotic or haemorrhagic risk and survival in young asymptomatic ET patients with a platelet count < 1500 x 10(9)/l. Therefore the optimal management of these patients is unknown. To assess the incidence of thrombosis and haemorrhages in this group of patients we carried out a prospective observational study in a cohort of 65 patients with ET, aged < 60 years, with no history of thrombosis or haemorrhage and platelet count < 1500 x 10(9)/l, and in 65 age- and sex-matched controls. Patients were not treated with cytoreductive therapy until the occurrence of thrombosis or haemorrhage. Arterial or venous thrombotic events were objectively documented both in cases and in controls. The median follow-up was 4.1 years, with an incidence of thrombosis in patients and controls of 1.91 and 1.50 cases/100 patient-years, respectively. The age- and sex-adjusted risk rate ratio was 1.43 (95% CI 0.37-5.4). Only three minor haemorrhagic episodes occurred in patients, with an incidence of 1.12 cases/100 patient-years. Pregnancy and surgery were not associated with thrombosis in these patients. We conclude that the thrombotic risk in young ET patients, with no thrombotic history and a platelet count < 1500 x 10(9)/l, is not increased compared to the normal population and that a conservative therapeutic approach should therefore be considered in these patients.

Adolescent↗
PubMed1998

Prothrombin as cofactor for antiphospholipids.

Prothrombin is a common antigenic target of antiphospholipid antibodies, since anti-prothrombin antibodies are detected in about 50-90% of the patients. To allow proper immune recognition, prothrombin must be adsorbed on suitable anionic surfaces. The epitope(s) have not yet been identified: the majority of anti-prothrombin antibodies appear to be of poly- or oligoclonal nature. Anti-prothrombin antibodies, either alone or in combination with anti-beta2-glycoprotein I antibodies, are responsible for the lupus anticoagulant activity of about 75% of the cases of phospholipid-dependent inhibitors of coagulation. The two antibodies may be discriminated by means of specific coagulation profiles generated by the comparison of the ratio of the Kaolin Clotting Time (KCT) and the dilute Russell's Viper Venom Time (dRVVT): the KCT profile, which mainly reflects the presence of anti-prothrombin antibodies and the dRVVT profile, which is mostly associated with anti-beta2-glycoprotein I antibodies. This distinction, although somewhat artificial, may be clinically useful, since the KCT profile identifies patients at low risk to develop thrombosis. Similarly, most of the studies that measured anti-prothrombin antibodies by ELISA failed to find a significant association with thrombosis. In conclusion, the clinical relevance of these antibodies has not yet been established.

Adsorption↗
PubMed1998

The effect of very-low-dose warfarin on markers of hypercoagulation in metastatic breast cancer: results from a randomized trial.

Malignancy is a risk factor for thromboembolism and anti-cancer chemotherapy can increase this risk. Prophylaxis of thrombosis with very-low-dose warfarin given concurrently with chemotherapy has a significantly reduced rate of thromboembolism in a randomized trial in women with stage IV breast cancer. In a group of 32 patients randomized in one center (16 subjects on warfarin and 16 on placebo), we have prospectively studied the plasma levels of: 1. Markers of 'in vivo' clotting activation (thrombin-antithrombin complex [TAT], prothrombin fragment 1+2 [F1+2] and D-dimer), 2. Factor VII (FVII), and 3. Natural anticoagulants (protein C [PC] and antithrombin [AT]). The aims of this study were: 1. to examine whether laboratory tests predicted those patients who developed thrombosis, and 2. to evaluate the effect of very-low-dose warfarin on hemostatic variables. The patients' hemostatic parameters were evaluated before entry into the study and after starting chemotherapy +/- prophylaxis, before each course for nine courses. Before-treatment results were compared to those of a sex and age-matched non-cancer control group. There was a significant elevation of plasma levels of TAT (p <0.001), F1+2 (p <0.001), D-dimer (p <0.0001) and FVIIa (p <0.05), as well as an increase of FVII proteolysis (p <0.05), whereas plasma PC and AT concentrations were not different from controls. After starting chemotherapy, markers of clotting activation were progressively lower in the group receiving warfarin prophylaxis compared to the group on placebo. Differences between the groups became statistically significant (p <0.01) after the 4th course of chemotherapy. Deep vein thrombosis occurred in two patients in the placebo arm. The results of this study indicate that before therapy, an hypercoagulable state is present in stage IV breast cancer, and after starting chemotherapy, abnormalities of hypercoagulation markers persist, however they are reduced by very-low-dose-warfarin. None of the laboratory variables could predict thrombosis in the single patient.

Adult↗
PubMed1998

Short course infusional idarubicin plus intermittent cytarabine and etoposide for refractory hematologic malignancies: clinical and preliminary pharmacological results.

BACKGROUND AND OBJECTIVE: Idarubicin (IDA) is relatively immune to the multidrug resistance P-gp mechanism that is frequently expressed in recurrent and refractory hematologic malignancies. Owing to rapid metabolism in vivo, a continuous infusion (CI) of IDA might prolong exposure time to the parent drug rather than its more P-gp susceptible alcohol metabolite. For this reason we developed a brief retreatment schedule incorporating CI IDA in order to obtain clinical as well as preliminary pharmacological data in patients with refractory leukemias and lymphomas. DESIGN AND METHODS: Eligible patients had either advanced-stage acute myeloid or lymphoid leukemias (AML, ALL) or high-grade non-Hodgkin's lymphomas (NHL) which failed curative-intent frontline or salvage regimens in use at our institution during the study period (July-October 1992). CI IDA 5 mg/m2/d was employed together with intermittent (every 8 hours) intermediate-dose cytarabine (500 mg/m2) and etoposide (200 mg/m2); all drugs were given for 2-4 days. A preliminary pharmacokinetic evaluation of CI IDA was carried out in three patients, including a comparison with bolus delivery in one. The in vitro effects of CI-type vs bolus-type IDA delivery in terms of intracellular IDA accumulation and related pro-apoptotic activity were assessed in P-gp- and P-gp+ human leukemic CEM cells by means of cytofluorimetry (IDA fluorescence intensity = FI, annexin V expression), with and without the addition of P-gp inhibitor cyclosporin A (CsA). RESULTS: Complete (2) or partial (4) responses were achieved in a total of 12 patients (17% and 33%, respectively), despite prior treatments with anthracyclines (100% of cases) and cytarabine-etoposide (33% of cases). Hematological toxicity caused the duration of treatment to be reduced from 4 days to 2 days after the first 4 patients. The procedural death rate was 42% (5/12), which was probably related in part to the sum of adverse prognostic characteristics: median patient age 55 years, two-thirds of cases having previously failed second/third-line regimens. The pharmacokinetic study showed an increased plasma AUC value with CI IDA in one patient (2.9-fold increase vs bolus delivery) due to the prolonged presence of low IDA plasma levels (10-20 ng/mL vs 50 ng/mL), as seen in two other cases as well. On the other hand, the in vitro study did not prove to be in favor of CI IDA because the FI threshold (> 1500 units) associated with increased apoptosis of P-gp+ cells (> 10%) was achieved only with bolus-type IDA exposure (50 ng/mL for 30') plus CsA. INTERPRETATION AND CONCLUSIONS: This short regimen demonstrated activity against end-stage leukemias and lymphomas and might prove to be more effective and less toxic in younger patients and in those with less advanced disease. In view of the results from plasma pharmacokinetics and in vitro intracellular IDA accumulation and apoptosis assays in lymphoblastic CEM cells, CI IDA 5 mg/m2/day may not represent a better therapeutic option than a rapid bolus injection, particularly in P-gp+ neoplasms. If obtaining an adequate intracellular drug concentration is the primary treatment goal, a higher CI IDA dosage, the addition of a P-gp down-regulator such as CsA and others, and in vivo study focusing on tumor samples from patients could all be helpful.

Aged↗
PubMed1998

Treatment of polycythemia vera.

BACKGROUND AND OBJECTIVE: Current guidelines for the management of patients with polycythemia vera (PV) derive from a few clinical trials and several uncontrolled clinical studies. The purpose of this paper is to critically review the available evidence in literature for selecting the best treatment in the single patient. METHODS: The authors have been working in this field contributing original papers whose data have been used for this study. In addition, the material analyzed in this article includes papers published in the journals covered by the Science Citation index and Medline. RESULTS: Therapeutic strategies for patients with PV include both cytoreductive and antithrombotic drugs. Among cytoreductive treatments, phlebotomy is associated with poor compliance and an increased incidence of thrombosis in the first three-five years, whereas chemotherapy may induce an higher risk of secondary malignancies after seven-ten years of follow-up. New cytoreductive drugs virtually devoid of mutagenic risk include alpha-interferon and anagrelide, but their role in reducing thrombotic complications or mortality remains to be demonstrated. Antithrombotic drugs, such as aspirin, are frequently used in PV, despite doubts regarding safety and efficacy. CONCLUSIONS: The management of patients with PV is a difficult balance between the prevention of thrombotic complications and the risk of drug side effects and toxicity. Appropriate studies are needed and an European collaboration has been set up for launching a randomized, placebo-controlled clinical trial (European Collaboration on Low-Dose Aspirin-ECLAP study) aimed at testing the efficacy of low-dose aspirin in preventing thrombosis and prolonging survival in PV patients.

Humans↗
PubMed1998

A new combination of carboplatin, high-dose cytarabine and cross-over mitoxantrone or idarubicin for refractory and relapsed acute myeloid leukemia.

BACKGROUND AND OBJECTIVE: High-dose cytarabine (HIDAC) and new anthracycline-type drugs (mitoxantrone, idarubicin) are the mainstay of several active regimens against relapsed and refractory acute myeloid leukemia (AML). The present study was undertaken to assess the feasibility, toxicity, and antileukemic activity of carboplatin (CBDCA) added to a combination of the two former agents. DESIGN AND METHODS: Two regimens (R) of CBDCA plus HIDAC and either mitoxantrone or idarubicin (crossover) were sequentially evaluated. R-1 consisted of CBDCA 300 mg/m2/d (24-hour infusion) on days 1-4, HIDAC 1 g/m2/bd on days 1-5, and mitoxantrone/idarubicin 12/6 mg/m2/d on days 1-3, followed by granulocyte colony-stimulating factor (G-CSF). R-2, an attenuated-toxicity regimen, consisted of CBDCA and G-CSF as above, HIDAC on alternate days (1, 3, 5), and mitoxantrone/idarubicin 8/5 mg/m2/dose. Intended post-remission therapy included a similar, lower intensity course and a myeloablative phase supported by an allogeneic or autologous blood cell transplant. RESULTS: Twenty-nine patients (median age 53 years, one child) formed the study group: 10 (34%) had a primary refractory disease (8 to idarubicin-cytarabine-etoposide, ICE), 6 (21%) were at second or subsequent relapse, and 5 (17%) had a first remission lasting < 12 months. In addition, 4 patients (14%) had received prior HIDAC and 10 (34%) were relapsing after a bone marrow/blood cell transplant. Twelve patients were treated with R-1 and 17 with R-2. The complete response rate was 25% with R-1 and 53% with R-2, due to a significantly lower death rate by pancytopenic complications (p = 0.023). The probability of response by risk class was: primary refractory 30% (43% with R-2), > 2nd relapse 33% (50% with R-2), 1st relapse < 12 months 40% (50% with R-2), 1st relapse > 12 months 50% (75% with R-2), prior HIDAC 75%, and prior transplant 30% (33% with R-2). Seven patients could undergo an autologous (n = 5) or allogeneic (n = 2) bone marrow/peripheral blood cell transplant after one consolidation cycle. Overall survival was 4.2 months, significantly longer in responders (complete and partial: median 11 months) than non-responders (p < 0.001). Median duration of complete remission was 10 months and 2-year probability 0.31, but no patient remained disease-free at 3 years. INTERPRETATION AND CONCLUSIONS: R-2 was well tolerated, exerted a significant activity in high-risk AML, and is amenable to further improvements. However, the lack of long-term disease-free survivors indicates the need for innovative post-remission strategies.

Acute Disease↗
PubMed1998

Outcome assessment of age group-specific (+/- 50 years) post-remission consolidation with high-dose cytarabine or bone marrow autograft for adult acute myelogenous leukemia.

BACKGROUND AND OBJECTIVE: To assess outcome of an age-adapted post-remission strategy for adult patients with acute myelogenous leukemia (AML, FAB-M3 excluded), including autologous bone marrow transplantation (ABMT) or high-dose cytarabine (HIDAC) consolidation. DESIGN AND METHODS: AML patients in first complete remission (CR) after doxorubicin-cytarabine-thioguanine (DoxAT) chemotherapy were scheduled to receive two identical early consolidation courses followed by HIDAC (1 g/m2/bd for 6 days), if aged > 50 years, or HiDAC plus total body irradiation (TBI) plus ABMT if aged < 50 years, the bone marrow being harvested prior to the HiDAC/TBI regimen and unpurged. Results were examined by treatment intention and in actual treatment groups, by selected pretreatment and therapy-related variables, and compared with age and disease matched historical patients treated with DoxAT consolidation without additional HIDAC or ABMT. RESULTS: One-hundred and eight (70%) of 153 patients achieved a response and were evaluable after a follow-up of 3.3-8.8 years. According to treatment intention, long-term relapse-free survival (RFS) was significantly improved in both age groups compared with controls (< 50 years: 41% vs 15%, p < 0.05; > 50 years: 33% vs 22%, p < 0.005). Actually, 41 patients proceeded to ABMT and 24 to the HIDAC cycle (including 5 aged < 50 years), 23 had early consolidation only (1: refusal; 1: inadequate marrow harvest; 21: complications), 10 relapsed and 2 died very early into remission, 7 were submitted to an allogeneic BMT, and one denied any post-remission therapy. The long-term RFS rates for ABMT and HIDAC groups were 53% and 54% (47% for 19 patients aged > 50), respectively, significantly better than for historical patients or those unable to go beyond early consolidation (p < 0.005, adjusted for early adverse events). Overall 5-year survival rate was 40% (p < 0.0001), 54% for CR patients, 60% after ABMT, and 65% after HIDAC. Relative to the ABMT and HIDAC intensive treatment groups, only the presence of hepatosplenomegaly at diagnosis was associated with a significantly worse outcome like that of the control study. INTERPRETATION AND CONCLUSIONS: This age-adapted double post-remission consolidation strategy with ABMT (allo-BMT) or HIDAC was applicable to only about two thirds of responders and was effective in about half these cases, regardless of patient age or specific treatment modality. While the loss of CR patients from treatment realization was unrelated to the study design and depended mainly on recurrence of AML and toxic complication, the exact place of ABMT vs HIDAC consolidation remains unsettled, calling for a new study in comparable patient and risk groups.

Bone Marrow Transplantation↗
PubMed1997

The threshold for prophylactic platelet transfusions in adults with acute myeloid leukemia. Gruppo Italiano Malattie Ematologiche Maligne dell'Adulto.

BACKGROUND: Prophylactic platelet transfusions are usually administered to patients receiving myelotoxic chemotherapy when their platelet count falls below 20,000 per cubic millimeter. Some observations suggest that lower platelet counts can be appropriate in patients in stable condition, but the safety of lower thresholds is uncertain. METHODS: We evaluated 255 adolescents and adults (age, 16 to 70 years) with newly diagnosed acute myeloid leukemia (but not acute promyelocytic leukemia), who were treated in 21 centers. One hundred thirty-five patients were randomly assigned to receive a transfusion when their platelet count fell below 10,000 per cubic millimeter (or 10,000 to 20,000 per cubic millimeter in those with a temperature above 38 degrees C, with active bleeding, or a need for invasive procedures), and 120 patients were assigned to receive a transfusion when their platelet count was less than 20,000 per cubic millimeter. RESULTS: Patients in the group with a threshold of 10,000 platelets per cubic millimeter received 21.5 percent fewer platelet transfusions than the patients in the group with a threshold of 20,000 platelets per cubic millimeter (P=0.001). The numbers of red-cell units transfused were not significantly different between groups. Major bleeding (defined as any bleeding more than petechiae or mucosal or retinal bleeding) occurred in 21.5 and 20 percent of patients, respectively (P=0.41), and on 3.1 and 2.0 percent of the days of hospitalization. One episode of fatal cerebral hemorrhage occurred in the group with a threshold of 10,000 platelets per cubic millimeter; none occurred in the other group (P= 0.95). Actuarial estimates of survival during induction chemotherapy, actuarial estimates of the absence of major bleeding, and the length of hospital stay were not significantly different in the two groups. CONCLUSIONS: The risk of major bleeding during induction chemotherapy in adolescents and adults with acute myeloid leukemia (except acute promyelocytic leukemia, which we did not study) was similar with platelet-transfusion thresholds of 20,000 per cubic millimeter and 10,000 per cubic millimeter (or 10,000 to 20,000 per cubic millimeter when body temperature exceeded 38 degrees C, there was active bleeding, or invasive procedures were needed). Use of the lower threshold reduced platelet use by 21.5 percent.

Adolescent↗
PubMed1997

Molecular remission in PML/RAR alpha-positive acute promyelocytic leukemia by combined all-trans retinoic acid and idarubicin (AIDA) therapy. Gruppo Italiano-Malattie Ematologiche Maligne dell'Adulto and Associazione Italiana di Ematologia ed Oncologia Pediatrica Cooperative Groups.

Two hundred fifty-three patients with newly diagnosed acute promyelocytic leukemia (APL) were eligible to enter the multicentric GIMEMA-AIEOP "AIDA" trial during the period July 1993 to February 1996. As a mandatory prerequisite for eligibility, all patients had genetic evidence of the specific t(15;17) lesion in their leukemic cells confirmed by karyotyping or by reverse transcription-polymerase chain reaction (RT-PCR) of the PML/RAR alpha fusion gene (the latter available in 247 cases). Median age was 37.8 years (range, 2.2 to 73.9). Induction treatment consisted of oral all-trans retinoic acid (ATRA), 45 mg/m2/d until complete remission (CR), given with intravenous Idarubicin, 12 mg/m2/d on days 2, 4, 6, and 8. Three polychemotherapy cycles were given as consolidation. Hematologic and molecular response by RT-PCR was assessed after induction and after consolidation. At the time of analysis, 240 of the 253 eligible patients were evaluable for induction. Of these, 11 (5%) died of early complications and 229 (95%) achieved hematologic remission. No cases of resistant leukemia were observed. Of 139 cases studied by RT-PCR after induction, 84 (60.5%) were PCR-negative and 55 (39.5%) PCR-positive. One hundred sixty-two patients were evaluable by RT-PCR at the end of consolidation. Of these, 159 (98%) tested PCR-negative and 3 (2%), PCR-positive. After a median follow up of 12 months (range, 0 to 33), the estimated actuarial event-free survival for the whole series of 253 eligible patients was 83% +/- 2.6% and 79% +/- 3.2% at 1 and 2 years, respectively. This study indicates that the AIDA protocol is a well-tolerated regimen that induces molecular remission in almost all patients with PML/RAR alpha-positive APL. Preliminary survival data suggest that a remarkable cure rate can be obtained with this treatment.

Adolescent↗
PubMed1997

Identification of two novel isoforms of the ZNF162 gene: a growing family of signal transduction and activator of RNA proteins.

By differential screening of a cDNA library obtained from a GM-CSF-dependent human myeloid leukemia cell line (GF-D8), we identified two novel isoforms of the recently described ZNF162 gene, which is apparently linked to multiple endocrine neoplasia type 1. The shorter of these new isoforms, called B3, presents an open reading frame (ORF) of 1713 bp coding for 571 amino acids. Its nucleotide sequence is homologous to the cDNA coding for the ABCDF isoform of ZNF162, except for a 4-nucleotide insertion that results in a frame shift of the ORF starting from nucleotide 1725 of the ZNF162 sequence. As a consequence, the predicted translation product of B3 contains the consensus sequence of the A motif (G-X-X-X-X-G-K-S) of the "ATP/ GTP binding site," which is characteristic of several protein families including protein kinases. Moreover, B3 shows the use of a different stop codon and contains a different tyrosine-rich COOH terminus. The longer isoform, called B4, differs from the ABCDEF isoform of ZNF162 by the insertion, at position 2137, of 383 nucleotides leading to a different, proline-rich COOH terminus. The complex transcription pattern of the ZNF162 gene is characterized by four transcripts, of approximately 3.9, 3.7, 3.2, and 2.9 kb, in GF-D8 cells. The 3.7- and 2.9-kb transcripts are expressed in resting GF-D8 cells. Upon stimulation with GM-CSF the expression of these mRNAs is up-regulated in parallel with the induction of two additional transcripts of 3.9 and 3.2 kb. The same pattern of expression has also been observed in freshly isolated myeloid leukemia cells and normal CD34+ stem cells. In light of these data, and since GM-CSF is known to stimulate signal transduction pathways, it becomes relevant that all the different isoforms of ZNF162 contain the KH module, which is a sequence motif present in proteins playing a major role in regulating cellular RNA metabolism. A search for functional domains demonstrates that ZNF162 belongs to a new and growing family of genes dubbed STAR (signal transduction and activator of RNA) proteins that are thought to play a downstream role in cell signaling and also in RNA binding. The mammalian members include Sam68, which is a target of Src, Fyn, and Grb2, and the newly cloned mouse quaking proteins (qkI) necessary in early embryogenesis and myelination. Moreover, since ZNF162 is highly conserved from yeast to humans, it implies that this new pathway has a significant function.

Amino Acid Sequence↗
PubMed1997

Stat1 is induced and activated by all-trans retinoic acid in acute promyelocytic leukemia cells.

Treatment of freshly isolated acute promyelocytic leukemia (APL) cells and the myelogenous leukemia cell lines, NB4, HL-60, and U937, with all-trans retinoic acid (ATRA) results in a remarkable elevation in the amounts of Stat1 alpha and Stat2 proteins. Stat1 alpha protein levels are augmented by ATRA as a consequence of elevated amounts of the corresponding transcripts. The retinoid increases the levels of nuclear complexes that are capable of binding to interferon (IFN)-regulated consensus sequences and contain Stat1 and/or Stat2 proteins, and causes a rapid and long-lasting elevation in Stat1 alpha tyrosine phosphorylation. Transient transfection experiments show that ATRA enhances the transactivating properties of Stat1 alpha observed on an appropriate reporter gene, in the presence of the RAR alpha retinoic acid receptor, but not in the presence of the PML-RAR protein. Treatment of NB4 cells with ATRA is associated with a remarkable upregulation of the two IFN-responsive genes IFN-responsive factor 1 and 2'-5' oligoadenylate synthetase, as well as with an augmentation in the levels of IFN alpha secretion. Our data show that ATRA is capable of modulating the amounts and the state of activation of some of the components of the IFN intracellular signaling pathways. They also suggest that the retinoid can bypass IFN/IFN-receptor interactions and induce the expression of IFN-regulated genes.

2',5'-Oligoadenylate Synthetase↗
PubMed1997

Effect of all trans-retinoic acid (ATRA) on the adhesive and motility properties of acute promyelocytic leukemia cells.

All trans-retinoic acid (ATRA) induces complete remission in acute-promyelocytic-leukemia (APL) patients. This study investigated the adhesive properties of APL cells for the endothelium and the extracellular matrix, their motility and the effect of ATRA on these functions. Blasts from 7 APL patients adhered to resting and IL-1-activated endothelium, to the same degree as normal PMN. Adhesion was partially mediated by ICAM-1 and, for IL-1-activated endothelium, by VCAM-1 and E-selectin. These cells showed less adhesiveness for the matrix than PMN, although they maintained the same substrate preference: they adhered to fibronectin and thrombospondin, but not to laminin and type-IV collagen. Exposure to ATRA in vitro (1 microM for 48 to 96 hr) increased the adhesiveness of APL cells; this effect was particularly evident in the case of sub-endothelial matrix and fibronectin. A similar increment in adhesiveness was observed when comparing cells from 2 patients before and after treatment with ATRA. APL cells migrated in response to fMLP and motility was increased by ATRA. In conclusion, APL cells were less adhesive to the matrix than PMN, but treatment with ATRA considerably enhanced their adhesive properties. This could be important in determining the efflux of leukemic cells from the bone marrow and their tissue infiltration during ATRA therapy.

Adolescent↗
PubMed1997

BEAM chemotherapy and autologous haemopoietic progenitor cell transplantation as front-line therapy for high-risk patients with diffuse large cell lymphoma.

In two consecutive and unselected cohorts of diffuse large cell lymphoma (DLCL) patients with advanced stage disease (IIB or bulk or more) and aged < 60 years, we compared a standard (MACOP-B for 12 weeks, 60 patients) versus a high-dose chemotherapy programme (8 weeks of MACOP-B plus one or two cycles of intensification with mitoxanthrone, dexamethasone, high-dose Ara-C, and finally BEAM chemotherapy with autologous haemopoietic progenitor cell transplantation, 61 patients). 41 patients (68%) in the standard group and 51 (84%) in the high-dose chemotherapy group, achieved a complete remission (CR) or an uncertain complete remission (CRu) (P = 0.0491). With a median follow-up time of 28 months for the high-dose group and 63.5 months for the standard group, the actuarial estimate of event-free survival (EFS) at 2 years demonstrates a significant benefit (70% v 50%, P = 0.03) for patients treated with the intensive regimen. The analysis of subgroups of patients showed that only high-risk patients (two or three risk factors) benefitted from the high-dose chemotherapy programme. Nevertheless, the overall survival does not show a significant difference between the two treatment modalities. The treatment-related morbidity was similar and the mortality rate was 8% in the standard (MACOP-B) group and 3% in the high-dose chemotherapy programme. In conclusion, our results show that high-dose chemotherapy and autologous stem cell transplantation is a safe procedure which should be considered for the front-line treatment of non-Hodgkin lymphoma patients with poor prognostic features.

Adult↗
PubMed1997

Long-term haematological reconstitution following BEAM and autologous transplantation of circulating progenitor cells in non-Hodgkin's lymphoma.

We report on long-term haematological recovery and clinical outcome after high-dose chemotherapy supported by circulating progenitor cells (CPC) transplantation in non-Hodgkin's lymphoma (NHL) patients, and analyse the role of variables which might influence engraftment. 63 consecutive NHL patients were enrolled in this study. Two groups of patients were considered for analysis: the first 34 patients had untreated diffuse large cell lymphoma with unfavourable prognostic factors. A second group of 29 patients underwent transplantation for resistant or relapsing NHL with low, intermediate and high grade histology. All patients received the BEAM conditioning regimen. As already reported in many studies, all patients showed a rapid haematological reconstitution. 43 patients (68%) achieved long-term complete trilineage engraftment within a median of 107 d from CPC transplantation. The neutrophil count was the first parameter reaching complete normalization, and haemoglobin was the last. Failure to meet the trilineage levels was due to lack of platelet recovery and was more frequent in patients transplanted in the setting of salvage protocols. By Kaplan-Meier analysis, the probability of a full reconstitution was 80% in patients to whom transplant was offered as part of a front-line therapy and 50% when transplant was given in the salvage programmes. Multivariate analysis showed that sustained long-term haematological reconstitution was significantly related to younger age, the time taken to achieve short-term reconstitution, and bone marrow involvement.

Adolescent↗
PubMed1997

Flow cytometry of leucocyte alkaline phosphatase in normal and pathologic leucocytes.

Leucocyte alkaline phosphatase (LAP) is an enzyme expressed on the external aspect of the neutrophilic granulocyte plasma membrane, and represents a specific marker for the fully differentiated granulocyte. In this report we characterize 1B12.1, a monoclonal antibody raised against human bone alkaline phosphatase, by its ability to recognize the LAP protein. As assessed by Western blot analysis, following electrophoresis under non-reducing conditions, the antibody specifically reacts with LAP upon forced expression of the protein in simian COS-7 fibroblasts. In addition, the 1B12.1 antibody recognizes partially purified LAP isolated from peripheral blood granulocytes. With this antibody we developed a quantitative flow-cytometry-based method for the determination of LAP. Double fluorescence flow cytometry demonstrated that the LAP protein was present in relatively high amounts in neutrophilic granulocytes, but not in monocytes, natural killer cells, or B and T lymphocytes of normal individuals. The protein was completely absent in granulocytes obtained from chronic myeloid leukaemia and paroxysmal nocturnal haemoglobinuria patients. Higher than normal levels of LAP protein were evident in neutrophilic granulocytes of patients suffering from polycythaemia vera, essential thrombocythaemia and severe aplastic anaemia. However, the highest amounts of LAP protein were present in the granulocytes of normal individuals treated with G-CSF for the isolation of peripheral blood stem cells.

Alkaline Phosphatase↗
PubMed1997

Risk factors and prevention of vascular complications in polycythemia vera.

Risk factors for vascular complications in polycythemia vera (PV) include laboratory and clinical findings. Among laboratory values, the hematocrit has been clearly associated with thrombosis, particularly in the cerebral circulation. Platelet count is a possible but not yet clearly established predictor of vascular complications. Platelet function tests are of little help in prognostic evaluation because most attempts to correlate these abnormalities with clinical events have been disappointing. Clinical predictors of thrombosis include increasing age and a previous history of vascular events. Identifying risk factors for thrombosis is important to initiate therapy. Phlebotomy is associated with an increased incidence of thrombosis in the first 3 to 5 years, whereas chemotherapy may induce a higher risk of secondary malignancies after 7 to 10 years of follow-up. New cytoreductive drugs virtually devoid of mutagenic risk include interferon-alpha and anagrelide, but their role in reducing thrombotic complications remains to be demonstrated. Antithrombotic drugs, such as aspirin, are frequently used in PV, despite doubts regarding safety and efficacy. Two recent studies from the Gruppo Italiano Studio Policitemia Vera (GISP) assessed the rate of major thrombosis as well as the tolerability of low-dose aspirin in PV patients. These investigations created a favorable scenario for launching a European collaborative clinical trial (ECLAP study) aimed at testing the efficacy of low-dose aspirin in preventing thrombosis and prolonging survival in patients with PV.

Age Distribution↗