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Biomedical subjects

M Cazzola

Publications and source records attributed to M Cazzola.

At least 127 records · Page 7Linked to original sources

Recombinant human erythropoietin in the anemia associated with multiple myeloma or non-Hodgkin's lymphoma: dose finding and identification of predictors of response.

Previous phase I-II clinical trials have shown that recombinant human erythropoietin (rHuEpo) can ameliorate anemia in a portion of patients with multiple myeloma (MM) and non-Hodgkin's lymphoma (NHL). Therefore, we performed a randomized controlled multicenter study to define the optimal initial dosage and to identify predictors of response to rHuEpo. A total of 146 patients who had hemoglobin (Hb) levels < or = 11 g/dL and who had no need for transfusion at the time of enrollment entered this trial. Patients were randomized to receive 1,000 U (n = 31), 2,000 U (n = 29), 5,000 U (n = 31), or 10,000 U (n = 26) of rHuEpo daily subcutaneously for 8 weeks or to receive no therapy (n = 29). Of the patients, 84 suffered from MM and 62 from low- to intermediate-grade NHL, including chronic lymphocytic leukemia; 116 of 146 (79%) received chemotherapy during the study. The mean baseline Hb level was 9.4 +/- 1.0 g/dL. The median serum Epo level was 32 mU/mL, and endogenous Epo production was found to be defective in 77% of the patients, as judged by a value for the ratio of observed-to-predicted serum Epo levels (O/P ratio) of < or = 0.9. An intention-to-treat analysis was performed to evaluate treatment efficacy. The median average increase in Hb levels per week was 0.04 g/dL in the control group and -0.04 (P = .57), 0.22 (P = .05), 0.43 (P = .01), and 0.58 (P = .0001) g/dL in the 1,000 U, 2,000 U, 5,000 U, and 10,000 U groups, respectively (P values versus control). The probability of response (delta Hb > or = 2 g/dL) increased steadily and, after 8 weeks, reached 31% (2,000 U), 61% (5,000 U), and 62% (10,000 U), respectively. Regression analysis using Cox's proportional hazard model and classification and regression tree analysis showed that serum Epo levels and the O/P ratio were the most important factors predicting response in patients receiving 5,000 or 10,000 U. Approximately three quarters of patients presenting with Epo levels inappropriately low for the degree of anemia responded to rHuEpo, whereas only one quarter of those with adequate Epo levels did so. Classification and regression tree analysis also showed that doses of 2,000 U daily were effective in patients with an average platelet count greater than 150 x 10(9)/L. About 50% of these patients are expected to respond to rHuEpo. Thus, rHuEpo was safe and effective in ameliorating the anemia of MM and NHL patients who showed defective endogenous Epo production. From a practical point of view, we conclude that the decision to use rHuEpo in an individual anemic patient with MM or NHL should be based on serum Epo levels, whereas the choice of the initial dosage should be based on residual marrow function.

Adult↗

Cell kinetics of CD34-positive hematopoietic cells following chemotherapy plus colony-stimulating factors in advanced breast cancer.

Bone-marrow (BM) hematopoietic precursors are recruited into proliferative activity when colony-stimulating factors (CSF) are sequenced with chemotherapy (CT). Previous studies suggested that further CT can be safely administered only when the increased proliferative activity of these cells has subsided, because most cytostatic drugs selectively damage cycling cells. The safest interval between CSF discontinuation and the start of the next CT course needs to be ascertained in vivo. Thirty patients with advanced breast cancer were treated with an intensified FEC regimen, planned at 21-day intervals, sequenced with granulocyte-macrophage (GM)-CSF (15 patients) or granulocyte (G)-CSF (15 patients). Using flow cytometry (FCM) we evaluated the proliferation kinetics of CD34+ BM hematopoietic progenitors before CT+CSF and at different times after CSF administration was stopped. FEC+GM- and FEC+G-CSF sequences both induced a rapid and sustained increase in the percentage of BM myeloid precursors (BMMP%) and in the cycling status of CD34+BM cells. However, while the BMMP% remained elevated in both cases after CSF were stopped, the enhanced proliferative activity of CD34+ cells decreased more rapidly after GM- than after G-CSF. Using FCM, CD34+ BM-derived hematopoietic presursor cell kinetics is readily evaluated in the clinical setting. The administration of CSF following CT increases both the proliferative activity of CD34+ BM cells and the BMMP%. After CSF were discontinued a kinetic refractoriness of hematopoietic progenitors was more evident after GM-CSF than after G-CSF. These data may be of value in designing clinical trials to avoid cytostatic damage to the BM hematopoietic stem-cell compartment.

Aged↗

Oligodeoxynucleotides antisense to c-abl specifically inhibit entry into S-phase of CD34+ hematopoietic cells and their differentiation to granulocyte-macrophage progenitors.

A number of experimental observations suggest that the proto-oncogene c-abl participates in the regulation of hematopoietic cell growth. We used an antisense strategy to study the relationship between c-abl expression and hematopoietic cell proliferation and differentiation. Purified normal human bone marrow-derived CD34+ cells were obtained by immunomagnetic selection and incubated with 18-base-unmodified antisense oligodeoxynucleotides complementary to the first six codons of the two alternative first exons of c-abl, la and lb. At the end of incubation, an aliquot of cells was assayed for clonogenic growth and the remainder was used for flow cytometric analyses. Cell kinetics were evaluated by means of both single parameter DNA and bivariate DNA/bromodeoxyuridine (BrdU) flow cytometry. Apoptosis was routinely studied by DNA flow cytometric analysis and, in some cases, also through DNA agarose gel electrophoresis for detection of oligonucleosomal DNA fragments. Expression of differentiation markers was studied by flow cytometry. Exposure to antisense oligonucleotides specifically inhibited the accumulation of c-abl mRNA in CD34+ cells. Preincubation with the c-abl antisense oligomers reduced the proportion of cells in S-phase from 19% +/- 5% (mean +/- SD) to 7% +/- 4% (P < .05), and BrdU labeling from 13% +/- 6% to 6% +/- 3% (P < .05). Flow cytometry and DNA agarose gel electrophoresis showed that treated CD34+ cells accumulated in the G0/G1 region of the DNA histogram with no evidence of either differentiation or apoptosis. By contrast, both growth factor deprivation and exposure of CD34+ cells to the tyrosine kinase inhibitor tyrphostin AG82 clearly induced apoptosis. When cells were preincubated with antisense oligonucleotides and then plated for evaluation of colony formation, this resulted in a significant inhibition of colony forming unit granulocyte-macrophage growth (from 44 +/- 15 to 22 +/- 9; P < .01) but had no effect on burst-forming unit erythroid growth (24 +/- 11 v 21 +/- 11; P < .05). These results suggest that c-abl expression is critical for entry of human CD34+ hematopoietic cells into S-phase and for their differentiation to granulocyte-macrophage progenitors. They also indicate that other tyrosine kinases besides p145c-alb are active in the prevention of apoptosis, so that inhibition of c-abl RNA accumulation arrests CD34+ cells in G0/G1 without activating programmed death.

Antigens, CD34↗

Juvenile chronic myelogenous leukemia: in vitro characterization before and after allogeneic bone marrow transplantation.

In previously published studies on patients with juvenile chronic myelogenous leukemia (JCML), excessive proliferation of malignant monocyte-macrophage elements and impaired growth of normal hematopoietic progenitors were demonstrated. A selective hypersentivity of granulocyte-macrophage progenitors (CFU-GM) to granulocyte-macrophage colony stimulating factor (GM-CSF) seems to represent the main pathogenetic mechanism. Allogeneic bone marrow transplantation (BMT) has been demonstrated to be the only curative strategy for patients with JCML. In this study, we evaluated the growth of peripheral blood hematopoietic progenitors in semisolid cultures in two children with JCML before and after allogeneic BMT. Serum levels of GM-CSF, interleukin-1 (IL-1) and tumor necrosis factor-alpha (TNF-alpha) were also assessed. IL-1-beta, GM-CSF and TNF-alpha serum levels of the patients before and after BMT did not differ significantly from those obtained in 45 healthy controls. After marrow transplant, the engraftment of donor hematopoietic stem cell was associated with the disappearance of both pretransplant GM-CSF hypersensitivity and CFU-GM spontaneous growth. The inhibitory effect on the growth of normal hematopoietic progenitors also resolved. This confirms that the substitution of the pathological hematopoietic progenitors represents the basis for the curvative effect of allogeneic BMT in the treatment of JCML, abolishing both the excessive responsiveness of JCML progenitor cells even to very low concentrations of GM-CSF and the growth-inhibitory effect on normal hematopoiesis.

Bone Marrow Transplantation↗

A comparison of the bronchodilating effects of salmeterol, salbutamol and ipratropium bromide in patients with chronic obstructive pulmonary disease.

Bronchodilator efficacy of salbutamol (200 micrograms), salmeterol (50 micrograms) and ipratropium bromide (40 micrograms) aerosols has been compared in 16 patients with stable chronic obstructive pulmonary disease (COPD) using a double-blind placebo controlled cross-over design. When absolute changes in FEV1 were used as the response criterion, efficacy of the three drugs was significantly better than placebo (P < 0.05). The onset of bronchodilatation after ipratropium bromide was slower than after salbutamol, but ipratropium induced more and longer-lasting bronchodilatation than the adrenergic drug. Salmeterol was slower but its duration was longer than salbutamol. The onset of the effect of salmeterol was slower than ipratropium bromide, but salmeterol showed, on average, superior bronchodilator efficacy compared with the anticholinergic agent, sustaining bronchodilation longer than ipratropium bromide (responses to salmeterol were significantly (P < 0.05) greater than those to ipratropium bromide from 4-12 h time period, but from 15 min to 1 h time periods response to ipratropium bromide exceeded salmeterol). The mean FEV1 area under the curve was significantly (P < 0.05) larger after salmeterol when compared to ipratropium bromide and salbutamol. Moreover, the mean FEV1 area under the curve after ipratropium bromide was significantly (P < 0.05) higher than that after salbutamol. In any case, our data showed individual differences in patient response. We conclude that salmeterol compares favourably with ipratropium bromide in terms of effects on lung function at clinically recommended doses because it has a longer duration of action than ipratropium bromide. The longer dosing intervals, which may enhance compliance, encourage its administration in patients with COPD.

Administration, Inhalation↗

A screen for RAS mutations in individuals at risk of secondary leukaemia due to occupational exposure to petrochemicals.

Occupational exposure to petrochemicals, in particular benzene, has been identified as a risk factor in the development of acute leukaemia. A cohort of exposed (n = 44) and non-exposed individuals (n = 19) from the same petrochemical installation were screened by polymerase chain reaction (PCR) followed by oligonucleotide hybridization (ONH) for the presence of mutations in the H, K, and NRAS cellular proto-oncogenes. A KRAS mutation was detected in one individual from the exposed group who was haematologically normal at the time of sampling. The presence of this mutation was confirmed by nude mouse tumorigenicity assay and positively identified as a K13 Gly-Asp substitution by cloning and sequencing.

Adult↗

Role of 5-hydroxytryptamine in mediating adenosine-induced airway contraction.

We have investigated the role of 5-hydroxytryptamine (5-HT) on adenosine-induced guinea-pig trachea contraction. R-N6-phenylisopropyladenosine (R-PIA), an A1 receptor subtype agonist, induced a concentration-dependent contraction of tracheal rings. The pD2 values were 7.43 +/- 0.26. A 30-min pretreatment with 1,3-dipropyl-8-amino-4-clorophenylxantine (PACPX), a selective A1 receptor antagonist, shifted to the right the R-PIA concentration effect curves. Ketanserin (1 microM), a 5-HT2 receptor antagonist, also caused a rightward shift of the R-PIA concentration-effect curves. The changes for the pD2 values comparing the controls and the tissues incubated with ketanserin were statistically significant (P < 0.05). In the same experimental conditions, neither atropine (1 microM), nor diphenydramine (1 microM), nor indomethacin (5 microM) showed any effects. The challenge of R-PIA (1 microM) with said substances induced a release of 5-HT (4.8 +/- 0.20 fmol/ml) from guinea-pig trachea in presence or in absence of epithelium; in the same experimental conditions, this effect did not occur in the controls. Our data support the hypothesis that 5-HT plays a role in adenosine-induced airway contraction.

Analysis of Variance↗

Salmeterol and formoterol in partially reversible severe chronic obstructive pulmonary disease: a dose-response study.

When testing the response to beta 2-agonist drugs in severe chronic obstructive pulmonary disease (COPD), a dose-response assessment should be undertaken. This study compares the time course of inhaled salmeterol (25, 50 and 75 micrograms) and formoterol (12, 24 and 36 micrograms) at different doses in a group of 12 patients with partially reversible, but severe COPD (FEV1 of 12-32% of predicted values after beta 2-agonist drugs had been withheld for 24 h). All doses of salmeterol and formoterol induced a significant (P < 0.01) spirometric improvement over the 12-h monitoring period, when compared to the spirometric improvement after placebo, but while formoterol induced a dose-dependent increase of the FVC, FEV1 and FEF50, this was not the case for salmeterol. In fact, 75 micrograms salmeterol did not produce a further improvement of these parameters. Mean peak bronchodilation, expressed as the increase in FEV1 over baseline values, occurred 2 h after inhalation of the three doses of salmeterol, and 1 h after inhalation of the three doses of formoterol. A comparison of 50 micrograms salmeterol with 12 micrograms or 24 micrograms formoterol (clinically recommended doses), showed that improvement of FEV1 after salmeterol was statistically (P < 0.05) higher than that after the two doses of formoterol, although the mean peak bronchodilations were similar. This was because salmeterol has a longer duration of action than formoterol. These data demonstrate that salmeterol is equally effective as, but longer-acting than, formoterol at clinically recommended doses in patients suffering from COPD, with severe airway obstruction.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenergic beta-Agonists↗

A linkage between hereditary hyperferritinaemia not related to iron overload and autosomal dominant congenital cataract.

The only genetic disorder with elevated serum ferritin levels so far described is hereditary HLA-related haemochromatosis. On the other hand, hereditary cataract is both genotypically as well as phenotypically heterogenous, and no specific locus or any useful marker has been yet identified. We studied two Italian families in whom a combination of elevated serum ferritin not related to iron overload and congenital nuclear cataract is transmitted as an autosomal dominant trait. Affected individuals have normal serum iron and transferrin saturation, but high serum ferritin. Red cell counts are normal and venesection therapy rapidly produces iron-deficiency anaemia. This genetic disorder, which is characterized by hyperferritinaemia, differs from hereditary HLA-related haemochromatosis mostly for the absence of iron overload. A gene responsible for the congenital nuclear cataract likely maps on chromosome 19q close to the ferritin L-subunit gene. Within families with autosomal dominant congenital cataract, serum ferritin might be an early marker of disease.

Adult↗

Evidence for a polyclonal nature of the cell infiltrate in sinus histiocytosis with massive lymphadenopathy (Rosai-Dorfman disease).

Sinus histiocytosis with massive lymphadenopathy (SHML), or Rosai-Dorfman disease, is rare histiocytic disorder of known origin which shares several cell markers with Langerhans' cell histiocytosis (LCH). Although Rosai-Dorfman cells exhibit an aberrant immunophenotype, the indolent clinical course of SHML suggests a reactive disorder rather than a neoplastic process. Until recently this was prevailing opinion concerning LCH also, but recent studies have detected clonal histiocytes in all forms of this latter condition, which is therefore considered a clonal neoplastic disorder with highly variable biological behaviour. To determine whether the histiocytic proliferation in SHML is polyclonal or clonal we used X-linked polymorphic loci to assess clonality in lesional tissues in two women. Polymorphic regions of the human androgen receptor (HUMARA) locus were amplified by polymerase chain reaction (PCR) analysis. The HUMARA locus was informative in both cases and, following digestion with methylation-sensitive enzymes, typical polyclonal X-inactivation patterns were observed. Since abnormal cells accounted for > 90% lesional tissue cells, we conclude that Rosai-Dorfman histiocytic proliferation was polyclonal in the women studied.

Base Sequence↗

Relationship between transfusion regimen and suppression of erythropoiesis in beta-thalassaemia major.

In the management of beta-thalassaemia major, different transfusion schemes are employed with baseline haemoglobin levels ranging from 8 to over 12 g/dl. We studied the relationship between transfusion regimen and suppression of erythropoiesis in 52 patients with beta-thalassaemia major whose mean pretransfusion haemoglobin levels ranged from 8.6 to 10.9 g/dl. Multiple, regression analysis showed that serum transferrin receptor was the parameter more closely related to mean pretransfusion haemoglobin (r = -0.77, P < 0.001). As measured through serum transferrin receptor, erythroid activity was 1-2 times normal for pretransfusion haemoglobin levels between 10 and 11 g/dl. 1-4 times normal for levels from 9 to 10 g/dl, and 2-6 times normal for levels from 8.6 to 9 g/dl. Mean pretransfusion haemoglobin was also inversely related to serum erythropoietin (r = -0.72, P < 0.001), whereas it showed no or a weak relationship with Hb F, reticulocyte count, or circulating nucleated red cell count. This study suggests that serum transferrin receptor is a reliable indicator of suppression of erythropoiesis in beta-thalassaemia major. On the basis of our findings, pretransfusion haemoglobin values of < or = 9 g/dl should be adopted with caution, because these levels can be associated with an insufficient inhibition of erythroid marrow expansion. However, a transfusion programme, with a baseline haemoglobin of 9-10 g/dl, may provide enough suppression of erythropoiesis and allow a reduction in blood consumption as compared with the classic hyper- or supertransfusion schemes. Since fixed haemoglobin levels may not be the best target for transfusion treatment in all thalassaemic patients, assay of serum transferrin receptor may be helpful for individualizing the transfusion regimens.

Adolescent↗

A double-blind, placebo-controlled trial of local nasal immunotherapy in allergic rhinitis to Parietaria pollen.

We assessed the efficacy and safety of local nasal immunotherapy (LNIT) using an extract in macronized powder form of Parietaria pollen, a very important allergenic plant in the Mediterranean and other parts of the world. Twenty-six patients aged 13-37 years, with seasonal allergic rhinitis to this pollen, were enrolled in a double-blind placebo-controlled trial, carried out from autumn 1991 to the end of June 1992. They were selected on the basis of a positive skin-prick test, radioallergosorbent test (RAST) and intranasal challenge to Parietaria antigen. Patients were randomly divided into two groups of 13; the first group was given Parietaria antigen, and the second placebo. We recorded mean weekly symptom scores and drug consumption for 17 weeks during the pollen season in the year 1992, and specific serum-IgE and IgG levels. Three patients in the active group withdrew from the study because of bronchial symptoms. A significant difference was observed in mean weekly nasal symptom scores, in drug consumption and in specific nasal threshold to Parietaria allergenic extract in the treated and control groups. No difference was observed in serum IgE and IgG levels. Serum IgE levels rose significantly only in the control group after the pollen season. This study indicates that LNIT may be a useful alternative to traditional subcutaneous immunotherapy in patients with allergic rhinitis.

Administration, Intranasal↗

Immunotherapy with Alpare in patients with respiratory allergy to Parietaria pollen: a two year double-blind placebo-controlled study.

Allergy to Parietaria judaica pollen causes significant morbidity in many areas of the world. In addition to rhinitis, patients who are allergic to this pollen have a high incidence of asthma. The pollinating season is long, making this particular allergy challenging for clinicians to treat. This study was designed to determine if immunotherapy with an alum adsorbed partially purified Parietaria extract (Alpare Parietaria) containing a targeted maintenance dose of 12,500 BUs was effective in decreasing rhinitis symptoms in patients allergic to Parietaria. Using a double-blind placebo-controlled technique 36 patients received placebo or active extract for 2 years. Twenty (11 placebo and nine active) completed the 2 year study. Efficacy of treatment was evaluated by determining changes in skin reactivity, visual analog scores, diary symptom scores and end of study assessments. Reactions were monitored as well. Skin-test suppression was marginally significant in the actively treated group after 1 year and showed even more significant suppression after the second year. Nasal block, rhinorrhoea and sneezing all were significantly decreased in the active group. The nasal provocation test did not show a significant change after 1 year, in either group, but after 2 years of treatment the active group did show significant improvement. Although almost all patients in the actively treated group experienced local reactions, the incidence of systemic reactions was not different between the two groups. In conclusion, immunotherapy with this extract at this dose was effective in ameliorated rhinitis symptoms in patients allergic to Parietaria judaica.

Adolescent↗

Evaluation of the effects of pefloxacin on platelet aggregation in vitro and ex vivo in patients suffering from chronic bronchitis.

The effects of pefloxacin on adenosine-diphosphate (ADP) and collagen-induced human platelet aggregation in vitro and ex vivo in patients suffering from chronic bronchitis were investigated. In the in vitro study carried out on platelets from 12 healthy volunteers, pefloxacin had no effect on platelet function even at a concentration of 10 mg/ml, which is 1,500 times higher than that reached in vivo. In the ex vivo study carried out in 10 patients, who received pefloxacin twice daily for 7-10 days as 400 mg oral dose, the drug did not influence platelet aggregation up to 24 hours after administration of the last oral dose.

Adenosine Diphosphate↗

Pulmonary penetration of ceftazidime.

For an antibiotic to be effective in lower respiratory tract infections, it should be available in adequate concentrations in respiratory tissues and fluids. Cephalosporins usually achieve modest concentrations in the respiratory tract. In this study we have determined the pulmonary penetration of intramuscularly administered ceftazidime (a single dose of 1 g). Levels of ceftazidime in bronchial secretions (BS), bronchial mucosa (BM), epithelial lining fluid (ELF), and serum (S) were measured by microbiological assay in 25 patients suffering from acute exacerbation of chronic bronchitis who were divided into 5 groups of 5 subjects according to sampling time (1, 2, 4, 8 and 12 hours after the administration of the antibiotic). The peak S level was high (39.89 +/- 10.42 micrograms/ml at 1 hour) and mean S concentrations decreased slowly and were still detectable at 12 hours (1.07 +/- 0.45 microgram/ml). In all other samples, mean concentrations were in excess of the ceftazidime minimum inhibitory concentrations (MICs) for many relevant respiratory pathogens (Haemophilus influenzae 0.15 microgram/ml; Moraxella catarrhalis 0.06 micrograms/ml; Streptococcus pneumoniae 0.15 micrograms/ml; Klebsiella pneumoniae 0.4 microgram/ml). Concentrations in BM (7.05 +/- 2.38, 8.14 +/- 2.23, 6.40 +/- 1.63, 4.06 +/- 0.99 and 0.45 +/- 0.27 microgram/g) were higher than that in BS (6.87 +/- 1.96, 6.54 +/- 1.84, 3.52 +/- 1.23, 1.56 +/- 0.92 and 0.23 +/- 0.19 microgram/ml).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Effects of lomefloxacin and sparfloxacin on human platelet aggregation.

Platelet aggregation is inhibited by high concentrations of most antibiotics. For this reason it is important to evaluate the effects of new antimicrobial agents on platelet aggregation. Lomefloxacin and sparfloxacin are new difluorinated quinolone antimicrobial agents. The aim of this work was to evaluate in vitro the effects of lomefloxacin and sparfloxacin on adenosinediphosphate (ADP) and collagen-induced human platelet aggregation. Our data showed that both antibiotics (lomefloxacin and sparfloxacin) at therapeutic doses did not inhibit in vitro human platelet aggregation. Lomefloxacin, only at the highest tested concentration (1 mg/ml), which is far higher than the clinically achievable one, significantly (P < 0.05) inhibited collagen-induced platelet aggregation. Sparfloxacin also caused inhibition of collagen and ADP-induced human platelet aggregation only at the highest tested concentration (0.01 mg/ml), which is higher than that reached in vivo. These findings suggest that therapeutic doses of lomefloxacin and sparfloxacin do not affect human platelet aggregation.

Adenosine Diphosphate↗