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Biomedical subjects

G Piacentini

Publications and source records attributed to G Piacentini.

At least 19 recordsLinked to original sources
PubMed2005

Effect of budesonide and montelukast in asthmatic children exposed to relevant allergens.

BACKGROUND: Montelukast has been shown to be effective in controlling the increase in exhaled NO in asthmatic children re-exposed to house dust mite (HDM). This study compared the effect of low dose inhaled budesonide and oral montelukast in preventing the expected relapse of airway inflammation and reactivity in a group of 24 mild asthmatic children allergic to HDM after a brief period of exposure to relevant allergens. METHODS: Lung function, bronchial hyperresponsiveness (BHR) to methacholine (PC(20)), fractional exhaled nitric oxide (FeNO) levels and sputum eosinophilia were evaluated. RESULTS: Pulmonary function remained stable. The BHR was unchanged after exposure in the group treated with budesonide, whereas a significant increase (P = 0.028) was observed in the patients receiving montelukast. No significant difference was observed in FeNO levels after exposure to mite antigen in the two groups. In both the groups of asthmatic children we observed a significant increase in sputum eosinophil % after the exposure to mite antigen. CONCLUSIONS: The significant increase in BHR level observed in the group of children receiving montelukast suggests a more comprehensive effect as disease controller by inhaled steroids than by leukotriene antagonist in allergic asthmatic children re-exposed to relevant allergens.

Acetates↗
PubMed2003

Cysteinyl leukotrienes and 8-isoprostane in exhaled breath condensate of children with asthma exacerbations.

BACKGROUND: Cysteinyl leukotrienes (Cys-LTs) and isoprostanes are inflammatory metabolites derived from arachidonic acid whose levels are increased in the airways of asthmatic patients. Isoprostanes are relatively stable and specific for lipid peroxidation, which makes them potentially reliable biomarkers for oxidative stress. A study was undertaken to evaluate the effect of a course of oral steroids on Cys-LT and 8-isoprostane levels in exhaled breath condensate of children with an asthma exacerbation. METHODS: Exhaled breath condensate was collected and fractional exhaled nitric oxide (FE(NO)) and spirometric parameters were measured before and after a 5 day course of oral prednisone (1 mg/kg/day) in 15 asthmatic children with an asthma exacerbation. Cys-LT and 8-isoprostane concentrations were measured using an enzyme immunoassay. FE(NO) was measured using a chemiluminescence analyser. Exhaled breath condensate was also collected from 10 healthy children. RESULTS: Before prednisone treatment both Cys-LT and 8-isoprostane concentrations were higher in asthmatic subjects (Cys-LTs, 12.7 pg/ml (IQR 5.4-15.6); 8-isoprostane, 12.0 pg/ml (9.4-29.5)) than in healthy children (Cys-LTs, 4.3 pg/ml (2.0-5.7), p=0.002; 8-isoprostane, 2.6 pg/ml (2.1-3.0), p<0.001). After prednisone treatment there was a significant decrease in both Cys-LT (5.2 pg/ml (3.9-8.8), p=0.005) and 8-isoprostane (8.4 pg/ml (5.4-11.6), p=0.04) concentrations, but 8-isoprostane levels remained higher than in controls (p<0.001). FE(NO) levels, which fell significantly after prednisone treatment (p<0.001), did not correlate significantly with either Cys-LT or 8-isoprostane concentrations. CONCLUSION: After a 5 day course of oral prednisone there is a reduction in Cys-LT and 8-isoprostane levels in EBC of children with an asthma exacerbation, although 8-isoprostane levels remain higher than in controls. This finding suggests that corticosteroids may not be fully effective in reducing oxidative stress in children with an exacerbation of asthma.

Adolescent↗
PubMed2003

Radical surgery does not recover immunodeficiency associated with gastric cancer.

Cell-mediated immunodeficiency is known to occur in advanced cancer patients, but it is less characterized in earlier stages. Pre-existing immunodeficiency may impair the recovery of postoperative lymphocytopenia, occurring generally within 8-14 days after surgical stress. This study was aimed to verify whether immunodeficiency exists in patients with operable gastric adenocarcinoma and whether radical surgery may restore a count of peripheral blood T helper cells (CD4) and CD4/CD8 ratio within physiological normal values in the late postoperative period. Thirty-five consecutive patients (M/F 18/17; mean age 67 years, range 42-82) with histologically proven gastric adenocarcinoma, undergoing surgery with radical intent, were studied. Assessment of total lymphocyte count and lymphocyte subsets was performed by FAC scan at baseline, then postoperatively 14 and 50 days after surgery. Normal reference values were according to CDC criteria for HIV immunodeficiency (total lymphocyte > 1500/mmc; CD4 cells > 500/mmc; CD4/CD8 > 1.2). Surgical interventions, including D2 locoregional lymphadenectomy, were as follows: 19 Roux Y total gastrectomies; 3 Roux Y subtotal gastrectomies and 13 Billroth II subtotal gastrectomies. Pathological nodal staging was pN0 in 18 and pN+ in 17 cases. Hystotype was intestinal in 14 patients, diffuse in 14 and unclassifiable in 7. Grading was G1 n = 7; G2 n = 7; G3 n = 21. Lymphocyte immunodeficiency was found at baseline in 41% of patients and at 14 days after surgery in 67% of patients. Recovery of postoperative surgery-induced lymphocytopenia occurred on the 50th day only in those patients with normal values at baseline (59%). CD4 deficiency was significantly more frequent in pN+ vs. pN0 patients, either at baseline (p < 0.001 ), on the 14th day (p < 0.02) and on the 50th day (p < 0.007) postoperatively. Cancer-related CD4 deficiency was a frequent finding in our consecutive series of gastric cancer patients; this systemic immune impairment was not restored after complete tumor removal, even in late postoperative period (50th day ). Further studies on a larger number of cases may confirm the prognostic value of lymphocyte count in early gastric cancer stages, and to verify whether early and late postoperative immunodeficiency may be prevented by IL-2 administration.

Adenocarcinoma↗
PubMed2003

Alteration of hypothalamus-pituitary-adrenal gland axis in colorectal cancer patients. Preliminary report.

AIM: In advanced cancer patients a cell-mediated immunological impairment, both at baseline and during postoperative period, is often found and is associated with poor prognosis. Cortisol is strictly involved in the response to major surgical stress, is an immunosuppressor and causes a redistribution of immunological population cells in different tissues. The aim of the study was to verify serum levels and circadian rhythm of cortisol in patients with colorectal cancer at baseline before surgery and in the postoperative period, and relate it to the immune status. METHODS: In 21 patients with colorectal cancer undergoing surgery we evaluated the assessment of total lymphocytes, CD4+, cortisolemia, circadian rhythm of cortisol (11 p.m. and 8 a.m.) at baseline and in 3(rd) and 7(th) postoperative days. RESULTS: Increase of cortisolemia, as decrease of total and CD4+ lymphocytes in the postoperative period versus baseline was statistically significant. Patients with an altered circadian rhythm were 47% and 36% at 3rd and 7th postoperative days, respectively. At baseline 19% of patients had an altered cortisol circadian rhythm and it was more frequent in patients with nodal involvement (p<0.05) and with metastasis (p<0.01). No relations between lymphocytopenia and alteration of cortisolemia and cortisol circadian rhythm were found, either at baseline or postoperatively (p<0.05). CONCLUSION: Lymphocytopenia in cancer patients seems not to be associated with cortisol level and circadian rhythm alteration, either at baseline or after surgical stress. An impairment of circadian rhythm of cortisol was found at baseline in 19% of patients. It was significantly associated with the presence of metastatic disease.

Adenocarcinoma↗
PubMed2001

Meal-induced thermogenesis and obesity: is a fat meal a risk factor for fat gain in children?

Diet composition, in particular fat intake, has been suggested to be a risk factor for obesity in humans. Several mechanisms may contribute to explain the impact of fat intake on fat gain. One factor may be the low thermogenesis induced by a mixed meal rich in fat. In a group of 11 girls (10.1 +/- 0.3 yr), 6 obese (body mass index, 25.6 +/- 0.6 kg/m(2)), and 5 nonobese (body mass index, 19 +/- 1.6 kg/m(2)), we tested the hypothesis that a mixed meal rich in fat can elicit energy saving compared with an isocaloric and isoproteic meal rich in carbohydrate. The postabsorptive resting energy expenditure and the thermic effect of a meal (TEM) after a low fat (LF; 20% fat, 68% carbohydrate, and 12% protein) or an isocaloric (2500 kJ or 600 Cal) and isoproteic high fat (HF; 48% fat, 40% carbohydrate, and 12% protein) meal were measured by indirect calorimetry. Each girl repeated the test with a different, randomly assigned menu (HF or LF) 1 week after the first test. TEM, expressed as a percentage of energy intake was significantly higher after a LF meal than after a HF meal (6.5 +/- 0.7% vs. 4.3 +/- 0.4%; P < 0.01). The postprandial respiratory quotient (RQ) was significantly higher after a LF meal than after a HF meal (0.86 +/- 0.013 vs. 0.83 +/- 0.014; P < 0.001). The HF low carbohydrate meal induced a significantly lower increase in carbohydrate oxidation than the LF meal (20.3 +/- 6.2 vs. 61.3 +/- 7.8 mg/min; P < 0.001). On the contrary, fat oxidation was significantly higher after a HF meal than after a LF meal (-1.3 +/- 2.4 vs. -15.1 +/- 3.6 mg/min; P < 0.01). However, the postprandial fat storage was 8-fold higher after a HF meal than after a LF meal (17.2 +/- 1.7 vs. 1.9 +/- 1.8 g; P < 0.001). These results suggest that a high fat meal is able to induce lower thermogenesis and a higher positive fat balance than an isocaloric and isoproteic low fat meal. Therefore, diet composition per se must be taken into account among the various risk factors that induce obesity in children.

Adipose Tissue↗
PubMed1999

Cell-specific differences in the regulation of IL-6 expression by PMA.

We have studied the regulation of IL-6 expression in human blood monocytes and lymphocytes. LPS and IFN-gamma induced IL-6 gene expression with a similar qualitative profile in both cell types. Treatment of monocytes and lymphocytes with PMA resulted, instead, in different effects: monocytes accumulated IL-6 and its message, while lymphocytes were inhibited either in the absence or the presence of LPS and IFN-gamma. These results suggest that the signal transduction pathways triggered by LPS and IFN-gamma are similar in both cell types, while PMA may activate a tissue-specific pathway which leads to opposite responses.

Cells, Cultured↗
PubMed1996

Increased nasal eosinophils in children with otitis media with effusion.

The pathogenesis of otitis media with effusion is still under debate, but allergic sensitization has been suggested in some cases. We investigated whether nasal cytology may indicate an allergic pathogenesis for otitis media with effusion. Atopic symptoms, results of skin prick tests to common aeroallergens, and nasal cytology by nasal scraping were evaluated in 40 children with current otitis media with effusion and compared with findings in a group of 40 healthy children. The presence of nasal eosinophils was significantly more frequent in children with otitis media with effusion than in the control group (p < 0.05). Nasal eosinophils were significantly associated with both allergic rhinitis (p < 0.001) and positive skin prick test results (p < 0.001). Allergic rhinitis with nasal eosinophilia was found in six children of the study group and in one child of the control group (p < 0.05). Our data suggest that nasal allergic inflammation may play a role in a subset of patients with otitis media with effusion. Therefore the possibility of allergic sensitization must always be considered in patients with serous otitis media.

Child↗
PubMed1993

Ligation of members of the beta 1 or the beta 2 subfamilies of integrins by antibodies triggers eosinophil respiratory burst and spreading.

Eosinophils interact with extracellular matrix proteins and endothelial cells through adhesion proteins belonging to the beta 1 and beta 2 subfamilies of integrins. Extending previous observations, we found that tumour necrosis factor (TNF) and granulocyte-macrophage colony-stimulating factor stimulated generation of superoxide anion by eosinophils plated on fibronectin-coated surfaces. As studies with adherent neutrophils indicated that TNF might act as activating leucocyte integrins to deliver signals involved in activation of cell functions, we investigated the effects of monoclonal antibodies (mAb) directed against VLA-4 (CD49d/CD29), LFA-1 (CD11a/CD18), CR3 (CD11b/CD18) or the common beta 2 subunit (CD18) on generation of eosinophil toxic oxygen molecules and spreading. We show that cross-linking of members of both the beta 1 and the beta 2 integrin subfamilies triggers eosinophil respiratory burst and spreading. Evidence for the selectivity of anti-integrin mAb effects is derived from the findings that isotype-matched mAb of other specificities (anti-class I MHC Ag, anti-beta 2-microglobulin, anti-CD4) did not trigger eosinophil functions. The findings presented in this paper suggest that integrin-dependent, eosinophil adhesion in sites of allergic reaction may be accompanied by release of toxic oxygen molecules involved in tissue damage.

Antibodies, Monoclonal↗
PubMed1991

Glucose-6-phosphate dehydrogenase activity and protein turnover in erythroblasts separated by velocity sedimentation at unit gravity and Percoll gradient centrifugation.

This work was undertaken to improve a separation method for preparation of large amounts of erythroid cells of different age with homogeneous and minimal contamination of myeloid cells. Our method was suitably employed in the study of the decay mechanism of glucose-6-phosphate dehydrogenase (G6PDH) during the erythroid cell maturation. Twenty fractions of erythroid cells at different advancing stages of maturation were prepared by fractionating, at unit gravity, bone marrow cells from anaemic rabbit. The specific activity of the G6PDH was assayed and plotted vs the fraction number and the typical sigmoid curve of the activity decay was drawn. The separated cells were then grouped in three sets of fractions following the three phases of the sigmoid curve and the fractions of each set were combined. From the cytochemical analysis of the three main fractions so obtained, we found a 25-30% myeloid cell contamination in the first fraction, while in the other two fractions the myeloid contamination was 10% or less. For this reason we performed a rapid separation of the first fraction on a discontinuous percoll gradient. By this method, the myeloid cell contamination of the first fraction was levelled down to the other two. The fractions, so obtained, (I, II and III in order of increasing cell maturation) showed a four fold decrease of glucose-6-phosphate dehydrogenase activity expressed both per cell number and on protein base. On the contrary the concentration of the total soluble proteins did not change significantly in the three fractions. The three purified cellular populations were used to provide information on the protein turnover of the erythroid cells during their development. We measured, in intact cells, the rate of synthesis and degradation of total proteins and then, in cell lysates, we determined the rate of degradation of G6PDH, purified from rabbit RBC and radiolabeled by reductive methylation with C14-formaldehyde. The rates of proteolysis obtained with total proteins and methyl-G6PDH clearly indicate that the proteolytic machinery of the erythroblasts reduces its activity during the cell maturation.

Anemia↗
PubMed1990

Efficacy and duration of action of oral procaterol in asthmatic children after single administration of different dosages.

A double-blind crossover study was performed to evaluate the bronchodilating effect of different single doses of procaterol (less than 0.5 micrograms/kg, 1.5 micrograms/kg, and placebo) orally administered. Sixteen asthmatic children, age 6-12 years, participated in the trial. Pulmonary function, heart rate, blood pressure, and tremor were evaluated at 30, 60, 90, and 120 min and then hourly for 8 hours after administration. All three doses were therapeutically effective. The 1.5 micrograms/kg dose produced a more sustained bronchodilatation effect, but was also associated with an increase in the incidence of tremors. The 0.5 micrograms/kg dosage may, however, be a good starting dose because it assures a reasonable risk/benefit ratio.

Administration, Oral↗
PubMed1990

Exercise-induced biphasic responses and methacholine reactivity in asthma.

Biphasic (early and late) asthmatic responses to exercise occurred in seven of 43 children with reproducible exercise-induced asthma. As biphasic allergen-induced asthma is associated with a prolonged increase in nonspecific bronchial hyperreactivity, this effect was not sought in the 43 asthmatic children. There was no significant change in methacholine PD20 FEV1 before and after exercise challenge, either in children who had early, or early and late, exercise responses. Late reactions after allergen exposure are likely to be of considerable clinical significance in relation to the enhancement of bronchial responsiveness. It is reassuring that this is not the case for exercise challenge, as it would have major implications in relation to the recommendations that asthmatics should participate in normal activities and even in training programs. Furthermore, it suggests that there are differences between the pathophysiology of asthma induced by exercise and that produced by allergens.

Adolescent↗
PubMed1990

[Hepatic hematopoiesis in phenylhydrazine-induced hemolytic anemia].

Ten adult rabbits were divided into two groups: the control rabbits, which received subcutaneous injections of 0.9% NaCl in three days; the experimental animals which received 3 mg/Kg body weight of phenylhydrazine (PHZ) subcutaneously also in three days. On the 8th day from the initial treatment the control and experimental animals were sacrificed, blood was collected to determine hematological parameters and livers were cut into small pieces. Sections were prepared by pressing the pieces onto slides which were stained with the Giemsa stain. The hematocrit and the reticulocytosis of experimental animals were 25 + 3%, and 70 + 5% respectively. In the liver sections of the PHZ treated animals we found a very rich population of immature erythroblasts. In fact proerythroblasts and basophilic erythroblasts were 19%, polychromatic and orthochromatic erythroblasts were 22% and 13% respectively. On the contrary, these cells were absent in the control livers. The lymphocyte and lymphoblast population, on the other hand, was very rich in control animals with a value of 38.8% compared to 1.62% in the anemic animals. The results clearly indicate the hematopoietic function of the liver in the anemic animals although the low percentage of orthochromatic erythroblasts with respect to their precursors suggests the ineffectiveness of the process.

Anemia, Hemolytic↗
PubMed1990

[Progression of the peripheral blood profile in phenylhydrazine-induced hemolytic anemia].

Male rabbits were made anemic by subcutaneous injections of 3 mg/Kg body weight of phenylhydrazine (PHZ) for the duration of three days. Blood samples were collected prior to the experiment, on the 2nd and 5th day from the end of the treatment. Hematocrit, reticulocyte count, MCV, osmotic resistance, RBC volume distribution curve and morphological analysis were performed on each sample in order to obtain a picture of the progressive changes of the parameters following the PHZ administration. Hematocrit values changed from 49 to 27%, whereas the reticulocytosis increased from 0.6 to 73%. A significant elevation of MCV was detected and the cell volume distribution curve, which presented the typical bell-shape profile in the normal animals became bimodal on the 5th day. The osmotic resistance of RBC of anemic animals, showed a marked deviation from the normal pattern. In fact initial haemolysis started at 0.75-0.70% NaCl concentration in the 5th day samples, while it was between 0.55-0.50% before the PHZ treatment. Finally, morphological analysis revealed a progressive increase of RBC with Heinz bodies, of macro-megalocytes and of immature erythroblasts thus indicating that the cell population, produced during recovery from PHZ induced anemia, is widely heterogeneous.

Anemia, Hemolytic↗
PubMed1990

[Effect of ATP on glucose-6-phosphate dehydrogenase during erythroblast maturation in the rabbit].

The glucose-6-phosphate dehydrogenase (G6PD) activity of erythroblasts, separated at different advancing stages of development, shows a marked decline of activity. A proteolytic mechanism, strictly controlled, is likely responsible of this decay, since a sufficient level of enzyme activity still remains in the circulating erythrocyte. In this report we suggest a model that could explain what triggers the mechanism of proteolytic degradation. HPLC analysis of the nucleotide content of erythroblasts and reticulocytes, showed a marked decline of adenine and pyridine nucleotides and of their catabolic products during the cell development. From thermostability tests, at fixed temperature, we have seen that ATP and NADP only, significantly protected the enzyme activity. In this light, we incubated 10 min at increasing temperatures, with and without ATP or NADP lysates of erythroblasts, separated at different stage of development and of reticulocytes. In the absence of nucleotides, we determined for all fractions a T degree break at 42 degrees C. In the presence of NADP all fractions were stabilized with no break point in the range 37-50 degrees C. On the contrary, the presence of ATP caused a progressive shift of the T degrees C break from the most immature erythroblasts (T degree break at 46 degrees C) to the reticulocytes (T degree break at 42 degrees C). Since ATP did not show any protective effect on the reticulocyte enzyme, we hypothesize the presence in these cells of a structurally modified G6PD. Furthermore, these data support our belief that the marked decline of ATP during cellular development, may represent the element responsible for the enzyme modification.

Adenosine Triphosphate↗
PubMed1990

[Splenic hematopoiesis in an experimental model of hemolytic anemia].

The splenic hemopoiesis of rabbits, made anemic with acetylphenylhydrazine, and of control animals was investigated. Pieces of spleen of both groups were fixed in formalin and embedded in paraffin. Paraffin sections, cut 5-7 microns in thickness, were stained with hematoxylin-eosin, Giemsa, Perls' method for tissue iron (hemosiderin), and Perls-Chayen's method for iron stored in the hemoglobin. The erythroid line in the anemic rabbits, showed a marked increase of proerythroblasts and basophilic erythroblasts, while the poli and orthochromatic erythroblasts were less than their precursors. In contrast these cells were more than their precursors in control animals. There was no notable quantitative difference in the mature elements of this line in the anemic animals and in the controls. Megaloblasts and macroblasts were frequently observed in anemic spleens but they were practically absent in the controls. Regarding to other cell lineages, we noted in the anemic spleens many macrophages containing Perls and Perls-Chayen positive material and some megakaryocytes. Our results indicate that the APH-induced anemia stimulate the erythropoietic activity of the spleen in the rabbit, but the reversion of the amplification phase of the differentiation steps reveals that the erythropoietic process is ineffective. The presence of megalo- and macroblasts provide morphological evidence of dyserythropoiesis and the megakaryocytes suggest that under the anemia condition also the platelet regenerating process is stimulated.

Anemia, Hemolytic↗
PubMed1990

[Glucose-6-phosphate dehydrogenase activity as a marker of resolution in the separation of rabbit erythroblasts according to their stage of maturation].

The glucose 6 phosphate dehydrogenase (G6PD) activity of erythroblasts, separated at different advancing stages of development by the velocity sedimentation technique at unit gravity, shows a characteristic sigmoidal curve. The G6PD activity is high and constant in the dividing compartment, steeply declines between the polychromatic and the orthochromatic stage, and returns almost constant during the development from the orthochromatic to the reticulocyte stage. This report focuses on the possibility to use the G6PD activity curve to indicate a loss of resolution in the fractionation process. For this purpose two parameters of the graph were used: (h) which represents the distance between the two constant phases of the curve and (s) the slope of the decreasing part of the graph. In this view we have fractionated on a 400 ml linear gradient of sucrose (1%-2% in PBS), increasing amounts of bone marrow cells from anaemic rabbit. Suspensions of 100, 200, 350 and 700 millions of cells (25 ml in PBS) were separated in different experiments and the obtained G6PD activity curves were compared. We have seen that the two parameters h and s remained constant up to 200 millions of cells, while they declined markedly when the number of cells loaded on the gradient increased to 350 and 700 millions. The separated cells were grouped into three sets of fractions: fraction I with cells belonging to the high and constant phase of the graph, fraction II to the decreasing phase and fraction III to the low and constant activity phase.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗