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Biomedical subjects

M Cazzola

Publications and source records attributed to M Cazzola.

At least 181 records · Page 10Linked to original sources
PubMed1992

Clinical pharmacokinetics of teicoplanin and aminophylline during cotreatment with both medicaments.

The influence of teicoplanin and aminophylline (theophylline ethylenediamine) on their mutual steady-state pharmacokinetics was studied in two parts, namely experimental and clinical studies. The concentrations of teicoplanin and aminophylline (theophylline) were evaluated at several times after intravenous administration of teicoplanin (3 and 15 mg/kg) and aminophylline (5 mg/kg) in 12 rabbits. Ten COPD patients were treated for 5 consecutive days with a short-term intravenous infusion of 240 mg aminophylline twice daily; ten more patients received for 5 days a short-term intravenous infusion of 200 mg teicoplanin twice daily. On the last day, blood samples were taken for teicoplanin and theophylline determination by means of the HPLC method. Subsequently, while aminophylline and teicoplanin were continued at the same dosage, the first ten patients received in addition a short-term intravenous infusion of 200 mg teicoplanin twice daily, and the second ten patients a short-term intravenous infusion of 240 mg aminophylline twice daily. After 5 days the serial assays of serum teicoplanin and theophylline were repeated. Our results demonstrated, in both experimental and clinical studies, no influence of theophylline on the steady-state pharmacokinetics of teicoplanin. Likewise teicoplanin had no significant effect on the steady-state pharmacokinetics of intravenous administration of theophylline in the form of aminophylline.

Aged↗
PubMed1992

c-abl function in normal and chronic myelogenous leukemia hematopoiesis: in vitro studies with antisense oligomers.

By using antisense oligomers the functional role of the c-abl proto-oncogene in the in vitro growth of bone marrow hematopoietic progenitors from normal subjects and patients with chronic myelogenous leukemia (CML) has been evaluated. Light density bone marrow cells (LDBMs) were depleted of adherent cells, pre-incubated for 15 h with the appropriate oligomer at a concentration of 14 microns, and then plated in methylcellulose for the evaluation of colony formation. Both anti-exon Ia and anti-exon Ib antisense oligomers produced a significant inhibition of normal day 14 CFU-GM growth in vitro (n = 5, 41 +/- 11%, and 36 +/- 7%, respectively; p less than 0.01). In contrast, normal BFU-E growth was not significantly influenced by antisense oligomers (n = 5, 14 +/- 21% and 7 +/- 19%, respectively; p less than 0.05). These findings were confirmed by plating CD34 positive progenitors. When interleukin 3 (IL-3) (100 ng/ml) was added to the culture medium during the preincubation of LDBMCs, the inhibitory effects of antisense oligomers on normal CFU-GM growth were abolished. Seven patients with CML were also studied, all of whom had cytogenetic evidence of 100% clonal hematopoiesis. In five patients in the chronic phase, antisense oligomers were inhibitory on in vitro growth of both day 14 CFU-GM (37 +/- 20% and 37 +/- 15%, p less than 0.05) and BFU-E (45 +/- 15% and 41 +/- 11%, p less than 0.05), and this inhibition was not removed by pre-incubation with IL-3. No significant effect was observed on cluster or colony formation in two patients with CML in accelerated or blastic phase, and on in vitro growth of clonogenic cells from the Ph1-positive K-562 cell line. These findings (i) confirm previous observations showing a lineage specific requirement of c-abl function in normal hematopoiesis, and (ii) suggest that the residual c-abl expression has a role in chronic phase CML hematopoiesis, as its inhibition impairs both myeloid and erythroid colony formation in vitro.

Base Sequence↗
PubMed1991

An atypical myeloproliferative disorder with high thrombotic risk and slow disease progression.

Among 761 consecutive patients with chronic myeloproliferative disorders (CMD), it was found that 18 (nine men and nine women) did not fulfill at presentation the established diagnostic criteria for the typical forms. In seven patients, the diagnosis of CMD was made on the basis of an intense and persistent thrombocytosis that complicated splenectomy. The other 11 patients had various combinations of the following signs suggesting CMD: splenomegaly, bone marrow myeloid hyperplasia and/or slight myelofibrosis, mild thrombocytosis and/or leukocytosis, and rare immature myeloid cells in the peripheral blood. All patients were younger than 46 years of age (median age, 31.5 years; range, 20 to 45 years). A major thrombotic event was the most frequent presenting feature (eight of 18 cases), and thrombotic complications supervened in seven of the eight splenectomized patients (six in the portal system), raising the overall rate of patients with thrombotic events in their history to 11 of 18. At a median follow-up of 50 months (range, 24 to 241 months), three patients had died of thrombotic complications (two after splenectomy). The 15 surviving patients had stable disease, and 12 of them were not receiving cytoreductive therapy. Spontaneous growth of circulating burst-forming units erythroid was demonstrated in one patient, and erythroid responsiveness to erythropoietin appeared higher than in the normal controls in four. Spontaneous in vitro platelet aggregation in whole blood and/or platelet-rich plasma was seen in five of seven patients. It was concluded that a difficult to identify, slowly progressive form of CMD occurs in young people, that it carries a high risk of thrombosis, and that splenectomy is a high risk procedure in these cases.

Adult↗
PubMed1991

Cytotoxic activity of an anti-transferrin receptor immunotoxin on normal and leukemic human hematopoietic progenitors.

The process of cellular iron uptake involves a specific receptor for the plasma carrier transferrin and a pathway of receptor-mediated endocytosis. Transferrin receptor expression is closely related to the rate of cell proliferation, and conjugates between anti-transferrin receptor monoclonal antibodies and toxins have been shown to have potent cytotoxic activity. We have constructed an anti-transferrin receptor immunotoxin by conjugating the anti-transferrin receptor monoclonal antibody B3/25 to a ribosome-inactivating protein, the saporin-6 (SO6), which is derived from the seeds of the plant Saponaria officinalis. The immunotoxin B3/25-SO6 was tested for in vitro cytotoxic activity against the human cell lines K-562 and HL-60 and against normal human bone marrow hematopoietic progenitors and acute myeloid leukemia clonogenic cells. The immunotoxin proved to be an effective inhibitor of K-562 and HL-60 clonogenic cell growth, in vitro colony formation being completely inhibited at immunotoxin concentrations ranging from 10(-7) to 10(-10) M. B3/25-SO6 markedly reduced the recloning efficiency of HL-60 clonogenic cells at 10(-12) M. Exposure of HL-60 cells in suspension culture to 10(-9) M B3/25-SO6 for 48-72 h completely abolished their clonogenic potential. The immunotoxin was also found to be cytotoxic against normal human bone marrow progenitor cells (burst-forming unit-erythroid and colony-forming unit-granulocyte, macrophage) in a dose-dependent manner. However, exposure of normal colony-forming unit-granulocyte, macrophage in suspension culture to 10(-9) M B3/25-SO6 for 72 h resulted in only 50% suppression of their clonogenic potential. Finally, B3/25-SO6 was found to be a potent inhibitor of in vitro growth of acute myeloid leukemia clonogenic cells. The cytotoxic effects of B3/25-SO6 were shown to be specific, since both saporin alone and irrelevant immunotoxins did not have any effect in the cellular systems examined. We conclude that the immunotoxin B3/25-SO6 has dose-related cytotoxic effects on both normal and leukemic human hematopoietic progenitors. Since there are substantial differences between normal and leukemic progenitors with respect to the proportion of cycling cells and the expression of transferrin receptors, B3/25-SO6 or similar immunotoxins may have clinical application in bone marrow-purging procedures.

Antibodies, Monoclonal↗
PubMed1991

Impact of rokitamycin, a new 16-membered macrolide, on serum theophylline.

Side effects have been observed when 14-membered macrolides, erythromycin and troleandromycin, have been prescribed concurrently in patients receiving therapeutic doses of theophylline. Rokitamycin is a new 16-membered macrolide antibiotic. We have evaluated its effect on theophylline serum concentrations in 12 adult patients suffering from chronic obstructive pulmonary disease. Initially, six patients were treated for four consecutive days with theophylline as sustained-release formulation in the amount of 600 mg daily; six other patients received for four consecutive days a short term intravenous infusion of 240 mg aminophylline, given over a period of 30 min twice daily. On the last day, blood samples were taken for theophylline determination. Theophylline concentrations were measured serially for 12 hours after oral formulation and 4 hours after aminophylline by enzyme immunoassay technique. Subsequently, while theophylline and aminophylline treatments were continued at the same dosage, each patient received in addition rokitamycin tablets, 400 mg every 12 hours. After seven days of this combined medication, the serial assays of serum theophylline were repeated at the same time intervals as before. Concomitant administration of therapeutic doses of rokitamycin did not affect significantly the steady-state pharmacokinetics of oral theophylline and did not alter the (pseudo-) steady-state pharmacokinetics of intravenous aminophylline, showing that the two drugs may be coadministered without any theophylline dose adjustment.

Aged↗
PubMed1991

Cefaclor in the treatment of infective exacerbations of chronic bronchitis in cigarette smokers.

There is a direct correlation between number of cigarettes smoked and the incidence of lower respiratory tract infection in humans. In studies with smokers suffering from exacerbations of chronic bronchitis, the most common bacterial pathogens found were Haemophilus influenzae, Streptococcus pneumoniae, Staphylococcus aureus and Branhamella catarrhalis. Antibiotics should be effective against such possible pathogens. Cefaclor has demonstrated in vitro activity against all these pathogens. We designed the present study to evaluate the efficacy and safety of cefaclor in the treatment of acute exacerbations of chronic bronchitis in cigarette smokers. A total of 106 patients were enrolled in the study. H. influenzae was the most common bacterial species isolated in the sputum (in 23.6% of the total sample), followed by S. pneumoniae (18.9%), S. aureus (17.0%), K. pneumoniae (7.5%) and B. catarrhalis (5.7%), while mixed forms were present in 22.6% of cases and other pathogens in 4.7%. Cefaclor (500 mg) was given orally every 8h for 7 to 16 days (mean 10.73 +/- 2.11). Analysis of clinical response data indicates that 75.5% of patients were cured and 17.0% improved. This finding is important because it demonstrates that cefaclor's spectrum of activity encompasses all the most likely pathogens encountered in smokers. Because of its excellent response rate, cefaclor is of particular value in the treatment of lower respiratory tract infections in cigarette smokers.

Adult↗
PubMed1991

Effects of cefonicid on platelet aggregation.

Beta-lactam antibiotics may interfere with platelet aggregation by inhibiting the binding of agonists of platelet aggregation, such as ADP and collagen, to specific receptor sites. The aim of this study was to evaluate in vitro the effects of cefonicid, a semi-synthetic cephalosporin, on platelet aggregation. Spontaneous platelet aggregation and platelet aggregation induced by ADP and collagen were assessed. Platelets from healthy subjects were incubated with cefonicid at final concentrations of 0.1 mg/ml, 1 mg/ml and 10 mg/ml (0.1 mg/ml is the concentration of cefonicid achieved in humans at therapeutic doses). When compared with saline, cefonicid at a concentration of 0.1 mg/ml had no effect on platelet aggregation, but at 1 mg/ml it inhibited ADP-induced aggregation and at 10 mg/ml it also inhibited aggregation induced by collagen. These findings suggest that therapeutic doses of cefonicid do not affect platelet aggregation.

Adenosine Diphosphate↗
PubMed1991

Influence of sulbactam plus ampicillin on theophylline clearance.

The effect of sulbactam/ampicillin (500 mg/1000 mg) every 12 hours taken for seven days on the steady-state pharmacokinetics of theophylline was studied among 12 patients suffering from chronic obstructive pulmonary disease. Theophylline concentrations were measured serially for 12 h by the method of polarized immunofluorescence (Abbott TDx system). No influence of sulbactam/ampicillin was detectable on the theophylline half-life, clearance or volume of distribution. It was concluded that both drugs could be administered concomitantly without any dosage adjustment of theophylline.

Adult↗
PubMed1991

An in vitro study of the possible interaction between human platelets and cephalosporins.

The effects in vitro of four cephalosporins (ceftazidime, cefuroxime, cefotaxime and ceftriaxone) on adenosine diphosphate-induced human platelet aggregation were investigated. Ceftazidime-induced inhibition of platelet aggregation was significant only at a final concentration of 1 mg/ml, whereas ceftriaxone-induced inhibition of platelet aggregation was also significant at a final concentration of 0.01 mg/ml. Cefotaxime and cefuroxime were less active than ceftriaxone.

Adenosine Diphosphate↗
PubMed1991

Tumor necrosis factor alpha modulates the messenger RNA expression of hematopoietic growth factor genes in fresh blast cells from patients with acute myeloblastic leukemia.

Tumor necrosis factor alpha (TNF-alpha) has been previously shown to modulate the expression of hematopoietic growth factor genes in monocytes and other mesenchymal cells. As acute myeloblastic leukemia (AML) blasts can express and produce hematopoietic growth factors, the influence of TNF-alpha on the accumulation of mRNAs for c-myc, interleukin-3 (IL-3), granulocyte-macrophage colony-stimulating factor (GM-CSF), G-CSF, IL-6 and IL-1 beta was evaluated in fresh blasts from 13 patients with AML. Total cellular RNA was extracted from blast cells cultured for 24 hours with or without TNF-alpha (500 U/ml). The c-myc transcript level was decreased by TNF-alpha treatment in 9/13 cases, and increased in only one case. Among the growth factor genes, the GM-CSF gene was more often and consistently influenced by TNF-alpha, increased levels of its transcript being observed in 6/13 cases following treatment with the cytokine; in no case was there a reduction of GM-CSF mRNA. G-CSF and IL-6 transcripts were more heterogeneously influenced, whereas the IL-3 transcript was never detected in our AML samples. The IL-1 beta message was present in 8/13 untreated and in 13/13 TNF-alpha treated samples. Moreover, in untreated cells, GM-CSF, G-CSF and IL-6 expression was always associated with IL-beta expression. These findings indicate that TNF-alpha can modulate the levels of growth factor transcripts in AML blasts, and raise questions about the effects of TNF-alpha on leukemic hematopoiesis, considering that TNF-alpha, IL-1 and GM-CSF can synergistically stimulate the growth of AML clonogenic cells.

Gene Expression Regulation, Leukemic↗
PubMed1990

An M1-selective muscarinic receptor antagonist telenzepine improves lung function in patients with chronic obstructive bronchitis.

The effect of an M1-selective muscarinic receptor antagonist telenzepine on lung function was investigated in 18 patients with chronic obstructive bronchitis in a double blind, placebo-controlled, randomized crossover study. FEV1, FEF50, PEF and FVC were measured every 0.5 h up to 2 h, then every 1 h up to 6 h after administration of a single, oral dose of 5 mg in the morning. Compared with placebo, telenzepine increased (time average over 6 hours; median and 68%-range): 1) FEV1 from 1.46 (0.81, 2.06) to 1.67 (1.06, 2.40) l, p less than 0.01; 2) PEF from 3.58 (2.33, 4.55) to 3.88 (3.10, 5.07) l/s, p less than 0.01; 3) FEF50 from 0.93 (0.45, 1.58) to 1.17 (0.67, 1.90) l/s, p less than 0.001. Whereas the median increase in FEV1 15 min after 2 puffs of salbutamol was 20% (range 15 to 74%), FEV1 improved by 32% (range -15 to 130%) at the time of maximum difference between placebo and telenzepine. The heart rate did not change. We conclude that in patients with chronic obstructive bronchitis substantial improvement of lung function parameters can be achieved by an M1-receptor antagonist. It is possible that with the dose administered direct actions on muscarinic receptors on the smooth muscle (M3) contribute to the observed bronchodilatation. The unchanged heart rate indicates little effect on cardiac M2-receptors.

Administration, Oral↗
PubMed1990

Immunocytochemical detection of ferritin in human bone marrow and peripheral blood cells using monoclonal antibodies specific for the H and L subunit.

We have used the monoclonal antibodies 2A4 (specific for the H subunit of human ferritin) and LO3 (specific for the L subunit) for immunocytochemical detection of ferritin in bone marrow and peripheral blood cells from normal subjects and patients with various haematological disorders. Formalin-fixed slides were stained by the immunoalkaline phosphatase procedure (APAAP). In normal subjects, ferritin could be found only in bone marrow smears and appeared to be largely confined to erythroid precursors and reticuloendothelial cells. The more immature erythroid precursors contained higher concentrations of cellular ferritin. Although evaluation could be only semiquantitative, erythroblast ferritin appeared to be more reactive with the monoclonal 2A4 (15 +/- 7% positive erythroblasts) than with the monoclonal LO3 (6 +/- 5% positive erythroblasts), indicating that H-type ferritin was predominant, particularly in proerythroblasts and basophilic erythroblasts. By contrast, the ferritin present in reticuloendothelial cells appeared to be predominantly of L-type. Patients with iron deficiency showed low levels of positive erythroblast, whereas the reverse was true in patients with transfusional iron overload. Intense positivity for reticuloendothelial cell ferritin was found in patients with anaemia of chronic disease. In myelodysplastic syndromes and acute myeloid leukaemia (AML), ferritin positivity was generally very strong at any stage of erythroblast development, particularly with the monoclonal antibody 2A4. Perls-positive perinuclear granules of ring sideroblasts were not stained, confirming that mitochondrial iron deposition is not in the form of ferritin. In AML and myelodysplastic syndromes with excess of blasts, ferritin could be detected also in immature myeloid cells. These data indicate that: (a) in normal conditions ferritin is mainly expressed in red cell precursors and reticuloendothelial cells, and this is in keeping with the peculiar role of these cells in iron metabolism; (b) abnormal cell ferritin contents can be observed in both iron overload and malignancy.

Antibodies, Monoclonal↗
PubMed1990

Effect of ketanserin, a new blocking agent of the 5-HT2 receptor, on airway responsiveness in asthma.

Most of the antihypertensive drugs have a liability for adverse effects in asthma. Since there are few available data on the effect of ketanserin, a new antihypertensive drug which is a type-2 serotonin receptor antagonist, on human respiratory function, we have tested whether this drug can modify bronchial hyperresponsiveness to methacholine in asthmatic patients. The protective effect of intravenous ketanserin (0.14 mg/kg) was small, but significant.

Adult↗