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Biomedical subjects

F Lanza

Publications and source records attributed to F Lanza.

At least 127 records · Page 7Linked to original sources
PubMed1994

Total loss of p53 DNA sequences in acute myeloid leukemia.

Mutations of the p53 tumour suppressor gene on chromosome 17p are a common genetic change in the malignant progression of many cancers. Here we report a case of a 71-year-old man with haematological, cytofluorimetric and cytochemical findings consistent with a 'de novo' M2 acute myeloid leukaemia (AML). A complex karyotype including a whole chromosome 17 and a t(17;?) (p11;?) was present in 8 of 10 metaphases of bone marrow cells. Southern blot analysis of the bone marrow DNA showed a specific loss of p53 gene in the AML cells. As far as we know, this is the first report of a deletion of both p53 alleles in leukaemia. The effect of the loss of p53 on the course of AML is discussed.

Aged↗
PubMed1994

Neutrophils from patients with myelodysplastic syndromes: relationship between impairment of granular contents, complement receptors, functional activities and disease status.

Myelodysplastic syndromes (MDS) are stem cell disorders of clonal origin in which infections and leukemic transformation are quite frequent. Neutrophils from 28 patients with MDS were analysed by flow cytometry for the expression of the two complement receptors CR1 and CR3, the antigenic reactivity of some granule constituents--myeloperoxidase, lysozyme, elastase, lactoferrin--and functional activities, such as locomotion, respiratory burst and cytotoxicity. The results were correlated with the FAB disease subtypes, grouped as low risk (RA) and high risk patients (RAEB, RAEB-t, CMML) and with 30 healthy subjects. A significant reduction in the percentage of neutrophil CR1, CR3 positivity and chemotaxis induced by endotoxin-activated serum was detected in the high risk group when compared with the low risk group and healthy controls. Furthermore, the high risk group also showed a low amount of myeloperoxidase, elastase, lysozyme and superoxide anion, but both low and high risk groups displayed reduced cellular cytotoxicity in comparison with the control. This work indicates that MDS patients belonging to the more advanced FAB categories frequently show multiple abnormalities in the expression of neutrophil complement receptors, and granular components (> 3), as well as in cell functions, suggesting the possibility of using these phenotypic abnormalities in the monitoring of disease progression.

Chemotaxis, Leukocyte↗
PubMed1994

Prognostic value of immunophenotypic characteristics of blast cells in acute myeloid leukemia.

In order to elucidate the prognostic role of cytofluorimetry analysis of leukemic cells in AML, the immunophenotypic characteristics of blast cells obtained from 66 AML patients belonging to M0-M2 and M4-M5 FAB subtypes have been investigated by flow cytometry using a large panel of monoclonal antibodies (McAbs) utilized in single, double, and triple fluorescence experiments. On a univariate analysis, four different immunophenotypic blast cell characteristics were found to be associated with a poor prognosis: expression of CD34 "bright" (ratio > 10 between fluorescence emission of positive cells and that of negative (isotypic) control-P/N ratio: mean MESF value: 265,000) in > 15% blast cells, co-expression of CD34 and CD33 in > 60% blast cells, expression of CD14 in > 30% leukemic cells, the MDR+ ("multiple drug resistant") phenotype. In contrast, the duration of remission, and overall survival of AML patients showing a "dim" CD34 expression (P/N ratio: 3-10: mean MESF value: 49,000) was similar to that of CD34- AML patients, irrespective of the percentage of positivity for CD34, which was, however, a predictive factor of survival in patients with higher CD34 fluorescence intensities in their blastic population. No correlation between FAB subtypes, prognosis and immunophenotype was found. The multivariate regression analysis showed that, besides age, only the combined expression of CD34 and CD33 had independent prognostic meaning. Indeed, in each FAB subtypes the CD34+/CD33+ phenotype was associated with a shorter survival and a lower mitotic rate. These data may contribute to the understanding of the discrepancies so far observed in the literature regarding the prognostic role played by the CD34 expression on leukemic AML blasts.

Antigens, CD↗
PubMed1994

Double-blind comparison of lansoprazole, ranitidine, and placebo in the treatment of acute duodenal ulcer. Lansoprazole Study Group.

OBJECTIVES: To study in a double-blind controlled manner the effects of lansoprazole 15 mg or 30 mg daily compared with ranitidine 300 mg once daily and placebo in the relieving of symptoms and healing of acute duodenal ulceration. METHODS: Two hundred eighty patients with duodenal ulcer entered in to the study from 30 centers. They were randomized in a double-blind manner into four groups with 80 patients entered into each active treatment group and 40 patients into the placebo group. Endoscopy was performed at 2- and 4-wk intervals to assess healing. Symptom relief was recorded, serum gastrin levels were measured, and gastric mucosal biopsies were obtained to evaluate for the presence of acute and chronic inflammation, the presence of neoplasia, and the extent of gastric endocrine growth at the time of endoscopy. RESULTS: After 4 wk of treatment using per protocol analysis, 19 of 40 (47.5%) patients receiving placebo had healed compared with 55 of 78 (70.5%) receiving ranitidine (p < 0.05 vs. placebo), 61 of 76 (80.3%) receiving lansoprazole 30 mg (p < 0.05 vs. placebo), and 72 of 78 (92.3%) receiving lansoprazole 15 mg (p < 0.05 vs. placebo and ranitidine). In patients with evaluable data, lansoprazole 30 mg and ranitidine produced greater relief of night-time symptoms and lansoprazole 15 mg produced greater relief of both day- and night-time symptoms than did placebo after 4 wk of treatment. Ranitidine increased fasting serum gastrin levels (22%; p < 0.05 vs. placebo), whereas both lansoprazole regimens produced more marked rises in serum gastrin (54% and 60%; p < 0.05 vs. placebo and ranitidine). Lansoprazole 15 mg and 30 mg also increased the density of antral G-cells (105.8% and 128.80%; p < 0.05 vs. baseline) and greater curvature Grimelius-positive cells (20.33% and 28.8%; p < 0.05 vs. baseline); there were no increases in the density of antral EC- or D-cells, and there was no alteration of gastric endocrine growth as judged by the Solcia classification. Both ranitidine and lansoprazole were associated with decreased antral Helicobacter pylori density accompanied, in the lansoprazole groups, by decreased antral inflammation scores. All antisecretory regimens were associated with increased inflammatory scores in the greater curvature. CONCLUSIONS: In acute duodenal ulceration, treatment with lansoprazole 15 and 30 mg produced 4-wk healing rates and symptom relief superior to those produced by placebo and the 15-mg dose similar to those produced by placebo. The 15-mg dose of lansoprazole was also superior to ranitidine in healing duodenal ulcer after 4 wk of therapy.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed1993

Cloning and characterization of the gene encoding the human platelet glycoprotein V. A member of the leucine-rich glycoprotein family cleaved during thrombin-induced platelet activation.

Glycoprotein V (GPV) is a major platelet membrane 82-kDa glycoprotein, missing in the Bernard-Soulier syndrome, that is cleaved when platelets are treated with thrombin. We report the cloning and sequencing of the GPV cDNA and gene obtained by a combination of polymerase chain reaction amplification of platelet mRNA and genomic library screening. The single-copy gene for GPV is contained within 6.5 kilobase pairs (kb) of genomic sequence and has a simple structure with a single intron of 958 base pairs in the 5'-untranslated sequence; the coding sequence is contained within a single exon. The promoter region contains a canonical TATA box, and putative GATA, Ets-1, and Sp1 cis-acting elements. Reverse transcription-polymerase chain reaction analysis on RNAs from cells of different hematopoietic origins revealed that GPV was specifically transcribed from platelets and from cells of the megakaryocytic lineage (megakaryocytes, HEL cells). A single transcript of 4.5 kb for GPV was detected in human platelets by Northern blot analysis. The entire amino acid sequence of GPV was deduced from the cDNA and genomic sequences. Mature GPV was composed of 544 amino acids which contained a single transmembrane domain, a short cytoplasmic domain (16 residues), and a large extracellular domain with 8 potential N-glycosylation sites. Analysis of the extracellular domain revealed the presence of 15 tandem Leu-rich repeats of 24 amino acids with homology to GPIb alpha and identified a cleavage site for thrombin near the COOH terminus with similarity to the A alpha chain of fibrinogen, but no hirudin-like sequence was found.

Amino Acid Sequence↗
PubMed1993

Thrombin regulates tissue factor and thrombomodulin mRNA levels and activities in human saphenous vein endothelial cells by distinct mechanisms.

The effects of thrombin, D-phenylalanyl-L-propyl-L-arginine chloromethyl ketone (PPACK)-inhibited thrombin, and thrombin receptor agonist peptide, SFLLRNPNDKYEPF (SFLL, a portion of the receptor unmasked after thrombin cleavage), on the expression of tissue factor (TF) and thrombomodulin by human saphenous vein endothelial cells (HSVECs) in culture were studied. Unstimulated cells contained very low amounts of TF mRNA as measured by the reverse transcriptase-PCR method. Thrombin treatment increased TF mRNA to 8.0 +/- 1.9 (n = 3) times the control level. The increase was detectable within 2 h and declined to near basal level by 6 h. Induction of TF mRNA was not blocked by cycloheximide, treatment with cycloheximide alone also increased TF mRNA levels, and thrombin in combination with cycloheximide further enhanced the accumulation of TF mRNA. Thrombin caused a 14.5 +/- 1.5-fold (n = 5) increase in TF activity on the surface of HSVECs and a 20.5 +/- 1.4-fold (mean +/- S.D., n = 2) increase in the extracellular matrix. The thrombin-induced effects on TF synthesis could be fully reproduced by the thrombin receptor agonist peptide, SFLL, whereas PPACK-inhibited thrombin did not influence TF expression. Thrombin increased thrombomodulin mRNA to 190 +/- 39% (n = 5) of control levels, whereas PPACK-inhibited thrombin or SFLL did not influence thrombomodulin mRNA levels. In contrast, surface-bound thrombomodulin cofactor activity and thrombomodulin antigen in the cell lysates did not change over 24 h of incubation with thrombin. However, thrombin caused a 2-fold increase in thrombomodulin antigen released into the conditioned medium, and immunoelectron microscopy of HSVECs also demonstrated the presence of thrombomodulin vesicles close to the luminal cell surface in thrombin-treated cultures. The Western blot pattern thrombomodulin in the conditioned medium of untreated and thrombin-treated cells was found to be similar, and soluble thrombomodulin occurred mainly as fragments of the cell-associated form. We conclude that the transcriptional control by thrombin causes an increase in both TF and thrombomodulin mRNA. The increase in TF mRNA levels is also paralleled by an increase in surface expression, is dependent on the proteolytic activity of thrombin, and is mediated by the same receptor as the recently cloned thrombin receptor in platelets. Up-regulation of thrombomodulin mRNA levels by thrombin is distinct from this pathway and is associated with unchanged expression on the cell surface.

Amino Acid Chloromethyl Ketones↗
PubMed1993

Fibroblasts increase adhesion to neutrophils after stimulation with phorbol ester and cytokines.

In our research there was spontaneous adhesion between resting fibroblasts and neutrophils in vitro which could be increased by stimulating either the coculture of cells or each cell type separately with various stimulants. Interferon-gamma, interleukin-1, and interleukin-6 significantly increased adhesion; however, the highest adhesive response was obtained when cocultures were treated with phorbol myristate acetate (PMA). As PMA-stimulated fibroblasts show the highest adhesion to resting neutrophils, it was suggested that adhesion was primarily due to an effect on fibroblasts. Without Mg2+ PMA did not stimulate fibroblast adhesion, whereas in the absence of Ca2+ the response was only partially reduced. Spontaneous adhesion was independent of both neutrophil integrins and fibroblast ICAM-1, whereas cytokine-stimulated adhesion was blocked by mAbs against ICAM-1; PMA-stimulated adhesion was not affected by mAbs anti-ICAM-1, but was partially inhibited by mAbs anti-beta 2 integrins. These results suggested the presence of mechanisms able to modulate the adhesive fibroblast-neutrophil interaction in inflammatory and wound healing processes.

Calcium↗
PubMed1993

Reduced expression of macrophage-associated antigens on alveolar mononuclear phagocytes from acquired immunodeficiency syndrome.

In this study we evaluated the phenotype of alveolar mononuclear phagocytes recovered from the bronchoalveolar lavage fluid of 24 patients with human immunodeficiency virus infection (AIDS-related complex 8 patients. AIDS 16 patients) and 8 healthy individuals by using a panel of monoclonal antibodies known to react with tissue macrophages, in combination with a flow cytometer. The results showed that 90% of patients with AIDS present a marked reduction in the expression of several antigenic determinants (in decreasing order: CD68, CD36, CR1, CD11c, HLA-DR). The levels of antigen expression by flow cytometry seem to decline with disease progression, showing the most dramatic perturbations in patients with full-blown AIDS associated with pulmonary infections (especially Pneumocystis carinii pneumonia) and lower peripheral CD4 lymphocyte counts. In contrast, patients with AIDS-related complex or AIDS without histological or cultural evidence of pulmonary involvement showed, respectively, only minimal or medium antigenic decreases. However, only a minor proportion (16%, 20%, 20%, 25%, and 25% respectively) of human immunodeficiency virus infected patients (mostly with AIDS) had a significant reduction of the levels of CD4, CD14, CD45R, CD11b, and CD16 antigens in the alveolar macrophages. Since macrophages play a central role in the pathogenesis of AIDS, it may be postulated that the loss of various phenotypic markers on alveolar mononuclear phagocytes (some of them known for their important immunoregulatory actions) could have an important part in the pathogenesis of human immunodeficiency virus induced immunosuppression, and thereby condition the abnormal susceptibility to pulmonary diseases typical of human immunodeficiency virus-infected patients.

Acquired Immunodeficiency Syndrome↗
PubMed1993

Abnormal expression of N-CAM (CD56) adhesion molecule on myeloid and progenitor cells from chronic myeloid leukemia.

Bone marrow and peripheral blood samples from 36 patients with Philadelphia chromosome positive chronic myelogenous leukemia (Ph+ CML) (30 in chronic phase, four in accelerated phase, and two in blastic crisis) were tested with two CD56 monoclonal antibodies (My31 and Eric 1) using the Facscan flow cytometer. Two- and three-color fluorescence experiments indicated that CD13+/CD33+ myeloid cells from 19 out of the 36 patients were positive for CD56 in 12-77% of the cells. In contrast, no CD56 positivity was documented in myeloid cells from bone marrow (BM) of healthy donors. Immunocytochemical staining (APAAP technique) of CML peripheral blood (PB) and BM slides showed that CD56 expression was detectable from the myelocyte stage with the strongest staining in the metamyelocyte stage. Neutrophils were negative both by flow cytometry and APAAP analysis. In individual CML patients, an increasing number of CD56+ cells were recovered with progressively higher density cuts (1.065-1.077 g/ml), supporting the concept that the antigen level tends to increase during myeloid differentiation. Furthermore, 19% of CML patients coexpressed CD56 and CD34 antigens in 10-45% of the CD34+ cells. The myeloid nature of CD56+/CD34+ CML cells has been ascertained by granulocyte-macrophage colony-forming unit (CFU-GM) assays on CD56+ cells sorted on FACS. Furthermore, in six out of eight CML patients in whom we performed a comparative BM and PB analysis, we found that the CD56 expression was brighter and the number of positive cells significantly higher in the peripheral blood myeloid cells as compared to their BM counterpart. In short-term liquid cultures, low doses (50 U/ml) of alpha interferon down-regulated the CD56 expression in CML cells, accompanied by a significant reduction of the Ph positivity. In conclusion, the expression of CD56 on CML myeloid elements seems to represent an aberrant phenomenon which could affect the cell homing mechanisms and, probably, the pattern of tumor cell dissemination. In patients with CD56+ CML, its detection could be further used as a means of monitoring patients undergoing bone marrow transplantation, since its reappearance is associated with early relapse of the disease.

Antibodies, Monoclonal↗
PubMed1993

[Immunophenotypic study of acute myeloid leukemia (AML): biological significance and prognostic implications].

The immunophenotype of 61 de novo AML referring to the Institute of Hematology of Ferrara between January 1988 and September 1992 was studied in order to evaluate the prognostic impact and the biological implications of this approach. In this study we confirm the possible aberrant expression of some antigens and the lack of a strict correlation between FAB classification and immunophenotype. The expression of the CD14 and CD34 was correlated with a worse prognosis, while the CD34+ patients further showed a lower probability to achieve a complete remission.

Aged↗
PubMed1993

The abnormal p53 proteins expressed in CML cell lines are non-functional.

Inactivation of the tumor suppressor function of the p53 gene is found in association with 20-40% cases of chronic myeloid leukemia (CML) in blast crisis. A common mechanism of p53 inactivation in CML is by complete deletion of one p53 allele in association with a point mutation which produces a mutant p53 protein on the remaining allele. Whether the mutant p53 protein, which is generally expressed at an elevated level, plays any role in the pathogenesis of blastic transformation or in maintaining the neoplastic proliferation, as it does in some solid tumors, is unknown. By using an antisense oligonucleotide approach, we investigated the cellular function of known abnormal forms of p53 protein, both mutant and truncated, expressed in CML cell lines. We found that the introduction of p53 antisense oligonucleotides can specifically inhibit the translation of the p53 mRNA. However, inhibiting p53 expression had no effect on cell proliferation, cell viability, and colony formation. There was no change in cell doubling time when the cells were maintained in serum-free medium (SFM) in the presence of antisense oligonucleotides compared with cells maintained in SFM alone. We conclude that the mutant or truncated p53 proteins expressed in the blast cells of CML have no growth-promoting effect and are not required for cell survival and proliferation. We further speculate that the loss of the tumor suppressor function of p53 might be the only mechanism by which p53 is involved in the transition from chronic phase to blast crisis.

Base Sequence↗
PubMed1992

CD38: a multi-lineage cell activation molecule with a split personality.

This review reports the characteristics of the human surface molecule CD38, a structure not linked to a definite line and predominantly expressed in early and activated phenotypes. The CD38 molecule consists of a single chain of 46 kDa, spanning the membrane and with the carboxyl terminus located in the extracellular compartment. The CD38 molecule is also involved in the transduction of activation and proliferation signals, which are line unrestricted. The gene coding for the CD38 antigen has been cloned and used for the construction of simian and mouse transfectants expressing the human molecule. These cell models are used for the analysis of several unanswered issues, mainly concerning the in vivo function of CD38, the existence of a natural ligand and of polymorphism in the population.

ADP-ribosyl Cyclase↗
PubMed1992

Calcium supplementation decreases rectal epithelial cell proliferation in subjects with sporadic adenoma.

The results of three small clinical trials examining the effect of calcium carbonate supplementation on the proliferation cytokinetics of the rectal epithelium in subjects with a current history of sporadic adenoma are reported. In six subjects, a daily administration of 1500 mg of calcium carbonate for 90 days failed to significantly suppress thymidine labeling in normal-appearing mucosa of the rectum. However, a daily dose of 2000 mg of calcium significantly (P = 0.008) altered mucosal proliferation in a second set of six subjects after a 30-day trial. Finally, a placebo-controlled trial of calcium (2000 mg) was conducted in which 20 subjects were randomized to groups receiving a 4-week intervention with calcium (or placebo), followed by the alternative treatment (placebo or calcium). The results of the study show a marked suppression of rectal proliferation during the calcium phase of the study but not during the placebo phase. This study adds to accumulating evidence showing that calcium supplementation regulates the proliferative behavior of colonic epithelium in the individual at high risk for colon cancer. Longer term trials of calcium supplementation will ascertain whether a continuing benefit from increasing dietary calcium translates into inhibition of adenoma recurrence.

Adenoma↗
PubMed1992

A new variant of Glanzmann's thrombasthenia (Strasbourg I). Platelets with functionally defective glycoprotein IIb-IIIa complexes and a glycoprotein IIIa 214Arg----214Trp mutation.

We describe a new variant of Glanzmann's thrombasthenia (variant Strasbourg I). The patient (M.S.) showed an absence of platelet aggregation to ADP, thrombin, and collagen, and a decreased clot retraction. Platelet fibrinogen was approximately 20% of normal levels. ADP-stimulated platelets bound markedly reduced amounts of soluble fibrinogen and platelet adhesion to surface-bound fibrinogen was defective. Normal to subnormal amounts of glycoprotein (GP) IIb-IIIa (alpha IIb beta 3) complexes, the platelet fibrinogen receptor, were revealed by SDS-PAGE, crossed immunoelectrophoresis, and antibody binding. However, the complexes were unusually sensitive to dissociation with EDTA at room temperature. Furthermore, flow cytometry showed that the platelets failed to bind the activation-dependent monoclonal antibody, PAC-1, after stimulation. In contrast, an RGDS-containing peptide induced significant binding of the anti-ligand-induced binding site antibody, D3GP3, suggesting the presence of a functional RGD binding domain on the patient's GPIIb-IIIa complex. Sequence analysis was performed after polymerase chain reaction amplification of selected patient's GPIIIa exons, and of the patient's platelet GPIIb and GPIIIa mRNAs. A point mutation (C to T) was localized in exon D (iv) of GPIIIa that resulted in an 214Arg to 214Trp amino acid substitution. The defect has been inherited from the parents who are heterozygous for the same mutation. This substitution points to an essential amino acid in a region of GPIIIa involved in the binding of fibrinogen and influencing the Ca(2+)-dependent stability of the GPIIb-IIIa complex.

Adult↗
PubMed1992

Complement receptor 1 (CR1) expression in chronic myeloid leukemia.

The complement receptor 1 (CR1), also called CD35, is a polymorphic glycoprotein which mediates a variety of neutrophil functions, including phagocytosis and, probably, tumor cell cytotoxicity. The role played by this molecule in chronic myeloid leukemia (CML) is not yet well understood. CML frequently shows a marked decrease of CR1 antigens on both the neutrophil population and myeloid precursors. This reduced expression appears to be related to disease activity, since patients at more advanced clinical stages, as well as those who develop blastic crisis, have been found to express the lowest levels of CR1 antigens. At the onset of the disease low CR1 expression on CML neutrophils seems to be associated with a higher risk of blastic transformation. Furthermore, CML neutrophils deficient in CR1 lack the ability to respond to PMA stimulation, suggesting a failure in CR1 granular storage. In patients lacking CR1, the number of receptors increased to normal levels following exposure of CML cells to therapeutic concentrations of recombinant alpha interferon. The role played by the CR1 molecule in sustaining neutrophil-mediated tumor cell cytotoxicity has yet to be definitively proved; studies performed by our group are relevant here, since complete suppression of tumor lysis following receptor neutralization by anti CR1 monoclonal antibodies was demonstrated in a large number of normal and CML individuals. In CML patients, the evidence of a direct relationship between lytic activity and antigen receptor levels seems to further support the involvement of CR1 molecules in tumor cell lysis, function.(ABSTRACT TRUNCATED AT 250 WORDS)

Blast Crisis↗
PubMed1992

[Fluorocytometric study of proliferation antigens, nuclear proteins and ploidy in acute leukosis].

P53 protein, Ki67 proliferative associated antigen and DNA content have been studied by flow cytometry in the blood blastic cells from 41 patients with acute leukemia. The results were compared with the F.A.B. classification. Cells were permeabilised and fixed by PLP solution before using the FITC conjugated Ki67 MoAb and the p53 MoAb (clone 1801). Propidium iodide and RNAase has been used in order to determine ploidy. Ki67 and p53 protein were found to be expressed at higher level in leukemia cells than in normal bone marrow cells; however there was no correlation between Ki67 and p53 expression and F.A.B. subtype. In acute leukemia patients the range of positivity of Ki67 was 1.1-52.1% while it ranged from 1.8% to 80.1% for the p53 protein. On the basis of these findings we conclude that the flow cytometry evaluation of Ki67 and p53 represents a useful tool for the study of the biologic characteristics of the leukemic cells in patients with acute leukemia.

Acute Disease↗
PubMed1992

Expression of p53 gene in B-CLL peripheral lymphocytes.

The p53 tumor suppressor gene expression has been studied in 23 B-CLL cases at different clinical stages. The analysis failed to show a direct correlation with each stage, but the significantly lower frequency of a BglII RFLP in the pathologic population suggests a role of this gene in B-CLL. Northern Blot analysis showed the expression of p53 mRNA in all the B-CLL cases. A protocol for the RT-PCR methods was set up to study a very small amount of materials which should be better used for sequence analysis.

DNA, Neoplasm↗