Biomedical subjects

M Silvestri

Publications and source records attributed to M Silvestri.

At least 37 records · Page 2Linked to original sources

PubMed2001

e-NO peak versus e-NO plateau values in evaluating e-NO production in steroid-naive and in steroid-treated asthmatic children and in detecting response to inhaled steroid treatment.

SUMMARY. Airway nitric oxide (NO) production can be measured by chemiluminescence analyzer in children able to perform a single low exhalation. The aim of the present study was to evaluate whether exhaled NO (e-NO) peaks (first part of the exhalation) were as useful as e-NO plateaus (last part of the exhalation) in evaluating e-NO production in asthmatic children and in detecting responses to inhaled steroid treatment. E-NO peak, plateau, and rate of production values were measured in 100 atopic asthmatic children using a chemiluminescence analyser. Thirty-seven patients (mean age, 11.1 +/- 0.7 years) were receiving inhaled steroids (flunisolide, 0.8-1 mg daily) or beclomethasone (0.2-0.4 mg daily), while the remaining 63 (mean age, 12.0 +/- 0.4 yrs) were-steroid naive and treated only with inhaled beta(2)-agonists on an as-needed basis. Fifteen out of the 63 steroid-naive patients were reevaluated after a short course (3 weeks) of inhaled corticosteroid treatment (flunisolide, 0.8-1 mg daily, or beclomethasone, 0.2-0.4 mg daily). Regardless of the type of data analysis (peak, plateau, or rate of production), the e-NO values of the steroid-naive patients were significantly higher than those of inhaled steroid-treated patients (P < 0.01, each comparison). Similarly, in the subgroup of steroid-naive patients, the three methods were able to detect a decrease in e-NO levels by inhaled steroid therapy (P < 0.001, each comparison). Plotting the difference between e-NO peak and e-NO plateau values against their average, the peak e-NO concentrations were higher than e-NO plateau values. This difference was independent of the absolute e-NO concentration. The results of the two types of data analysis seems to agree more closely in steroid-naive patients than in steroid treated patients, or in the subgroup of steroid-naive patients who received a short course treatment with inhaled steroids. In steroid-treated subjects, the differences were up to five times higher for peak than plateau e-NO values. These data suggest that both e-NO plateau and e-NO peak values are useful in detecting airway NO production in atopic asthmatic children, but they cannot be used interchangeably. Because of possible nasal contamination in e-NO peak measurement, we prefer e-NO plateau levels for evaluating lower airway e-NO production.

Administration, Inhalation↗

PubMed2001

Differential role of CD80 and CD86 on alveolar macrophages in the presentation of allergen to T lymphocytes in asthma.

In the asthmatic lung the altered expression of costimulatory molecules (CD80, CD86) by alveolar macrophages contributes to T lymphocyte activation and expansion. We hypothesized that CD80 and CD86 on alveolar macrophages could differentially support allergic inflammation in adult asthma. Here we studied 11 subjects with mild allergic asthma and 11 atopic non-asthmatics as controls. Dermatophagoides-specific T cell lines were derived from peripheral blood from each subject. Bronchoalveolar lavage with evaluation of lung inflammatory cells was performed in all individuals at baseline and 24 h after allergen challenge. The expression of CD80 and CD86 costimulatory molecules by alveolar macrophages was studied and, in parallel, the efficiency of antigen presentation was measured in terms of IL-4 and IL-5 production by allergen-stimulated autologous T cells. We found that in asthmatic subjects (i) the percent of CD80+, but not CD86+ alveolar macrophages was increased at baseline and did not change following allergen challenge; (ii) CD86, but not CD80, membrane expression was up-regulated following allergen challenge; (iii) both CD80 and CD86 were required to support Th2 cytokine production by allergen-specific T cells, with a prevalent role of CD86 after allergen challenge. Our data indicate that alveolar macrophages deliver costimulatory signals via CD80 and CD86, which support the production of Th2 cytokines by allergen-specific T cells. They also indicate that CD86 in vivo is up-regulated in the 24 h following allergen exposure and that this modulation is functionally relevant.

Adult↗

PubMed2001

Time-dependent changes in orally exhaled nitric oxide and pulmonary functions induced by inhaled corticosteroids in childhood asthma.

Exhaled nitric oxide levels are elevated in asthmatic children and decrease after inhaled steroid treatment. We evaluated the time-dependent changes in fractional exhaled nitric oxide concentration (FENO) and pulmonary function parameters following inhaled steroid therapy. Thirty-nine steroid-naive atopic patients (age 11.92+/-0.48 years) with mild intermittent asthma and 22 age-matched healthy controls were enrolled in the study; pulmonary functions and FE(NO) levels were measured. Low doses of inhaled steroids were prescribed to all asthmatic patients who were reevaluated in a second visit (between 10 and 40 days after the beginning of the treatment). At the enrolment, asthmatic patients had similar forced expiratory volume in 1 sec (FEV1) and forced vital capacity (FVC) values (p > 0.05) but reduced forced expiratory flows at 25-75% of the vital capacity (FEF(25-75%)) values, as compared to controls (p < 0.05). In addition, FE(NO) levels were significantly higher in asthmatics with respect to control subjects (30.8+/-3.0 and 4.0+/-0.5 ppb, respectively; p < 0.01). All asthmatics had FE(NO) levels higher than 8.8 ppb (i.e., > 2 standard deviations of the mean in controls). After steroid treatment, patients showed significant improvement of FEV1, FVC, and FEF(25-75%) (p = 0.0001; each comparison) and a reduction of FE(NO) levels (p = 0.0001). A weak significant correlation was found between percent decrease in FE(NO) levels and percent increase in FEV1 (r = 0.33, p = 0.04) or in FEF(25-75%) (r = 0.4, p = 0.01) after treatment. When changes in FE(NO) levels and in pulmonary function parameters were corrected for days of treatment, significant correlations were still present between percent decrease in FE(NO) levels and percent increase in FEV1 (r = 0.57, p = 0.0004) or percent increase in FEF(25-75%) (r = 0.45, p = 0.006). Sixteen of the 39 asthmatic patients were evaluated on two occasions after the beginning of treatment, at days 10 and 40. The significant reduction in FE(NO) levels (p < 0.01) and the significant increase in FEV1 and FEF(25-75%) values observed (p < 0.05) after 10 days did not further improve at day 40. These data show that it is possible to demonstrate early effects of low-dose inhaled steroids in asthmatic children using objective measurements of airway caliber and inflammation.

Administration, Inhalation↗

PubMed2001

Identification and typing of Malassezia yeasts using amplified fragment length polymorphism (AFLP), random amplified polymorphic DNA (RAPD) and denaturing gradient gel electrophoresis (DGGE).

Three molecular tools, amplified fragment length polymorphism (AFLP), denaturing gradient gel electrophoresis (DGGE) and random amplified polymorphic DNA (RAPD) analysis, were explored for their usefulness to identify isolates of Malassezia yeasts. All seven species could be separated by AFLP and DGGE. Using AFLP, four genotypes could be distinguished within M. furfur. AFLP genotype 4 contained only isolates from deep human sources, and ca. 80% of these isolates were from patients with systemic disease. Most of the systemic isolates belonged to a single RAPD genotype. This suggests that systemic conditions strongly select for a particular genotype. Although the clinical use of DGGE may be limited due to technical demands, it remains a powerful tool for the analysis of complex clinical samples.

Animals↗

PubMed2001

Exhaled nitric oxide levels in non-allergic and allergic mono- or polysensitised children with asthma.

BACKGROUND: Increased fractional exhaled NO concentrations (FENO) and blood/tissue eosinophilia are frequently reported in allergic children with mild asthma and are thought to reflect the intensity of the inflammation characterising the disease. The aim of this study was to investigate possible differences in FENO levels or in the intensity of the blood eosinophilia in allergic and non-allergic asthmatic children. METHODS: 112 children with stable, mild, intermittent asthma with a positive bronchial challenge to methacholine were consecutively enrolled in the study; 56 were skin prick test and RAST negative (non-sensitised) while 56 were sensitised to house dust mites (23 only to house dust mites (monosensitised) and 33 were sensitised to mites and at least another class of allergens (pollens, pet danders, or moulds)). Nineteen sex and age matched healthy children formed a control group. RESULTS: Compared with non-allergic patients, allergic children had a significantly higher rate of blood eosinophilia (p=0.0001) with no differences between mono- and polysensitised individuals. Forced expiratory volume in 1 second (FEV(1)), forced vital capacity (FVC), forced expiratory flow at 25-75% of vital capacity (FEF(25-75%)), and the degree of bronchial reactivity to methacholine were similar in non-atopic and atopic children, with no differences between mono- and polysensitised individuals. FENO levels measured by chemiluminescence analyser were higher in asthmatic children (15.9 (14.3) ppb) than in the control group (7.6 (1.6) ppb, p=0.04) and higher in allergic patients (23.9 (2.1) ppb) than in non-allergic patients (7.9 (0.8) ppb, p=0.0001), but there were no differences between mono- and polysensitised individuals (p>0.1). Significant correlations between blood eosinophilia and FENO levels were seen only in allergic (r=0.35, p<0.01) and in polysensitised individuals (r=0.45, p<0.05). CONCLUSIONS: In children with mild asthma, a similar degree of functional disease severity may be associated with a higher inflammatory component in allergic than in non-allergic subjects.

Adolescent↗

PubMed2001

Fluticasone and salmeterol downregulate in vitro, fibroblast proliferation and ICAM-1 or H-CAM expression.

Beta2-adrenoreceptor agonists have pharmacological properties that may suggest an inhibitory effect on various aspects of the inflammatory and repair processes that characterize asthma. Since fibroblasts express beta2-adrenoreceptors, the effects of different concentrations (0.1-100 nM) of fluticasone propionate (FP), salmeterol (S) and their combination (FP+S) on lung fibroblast proliferation and adhesion molecule expression were evaluated. Stimulation of human foetal lung fibroblasts with a fibrogenic cytokine, basic fibroblast growth factor (bFGF), resulted in a [methyl-3H] thymidine ([3H]TdR) uptake, four-fold higher than that of control cultures (p=0.0001) and was significantly inhibited by S, at all the concentrations tested (0.1-100 nM; p<0.05). No changes in bFGF-induced cell proliferation were observed in the presence of FP (0.1-100 nM; p>0.05, all comparisons). In addition, the association FP+S did not improve the inhibitory activity of S alone (p>0.05, each comparison). An upregulation of intercellular adhesion molecule-1 (ICAM-1) expression was induced by tumour necrosis factor-alpha (TNF-alpha) (p=0.0004), but not by interleukin-4 (IL-4) (p>0.05), while none of the two cytokines were able to increase hyaluronic-cellular adhesion molecule (H-CAM) expression by lung fibroblasts (p>0.05). A significant downregulation of ICAM-1 or H-CAM expression was demonstrated in the presence of FP or S, at all concentrations tested (0.1-100 nM; p<0.01, each comparison). Interestingly, S (10 nM and 100 nM) was able to enhance the inhibitory activity of FP on ICAM-1 expression (p<0.01), but not on H-CAM expression (p>0.1). These results show that in human foetal lung fibroblasts, fluticasone propionate and salmeterol are effective in modulating in vitro, different lung fibroblast biological functions that are likely to be involved in airway remodelling.

Albuterol↗

PubMed2001

The simplified papilla preservation flap in the regenerative treatment of deep intrabony defects: clinical outcomes and postoperative morbidity.

BACKGROUND: The aims of the present multi-center, randomized, controlled clinical trial were: 1) to compare the efficacy of the simplified papilla preservation flap with and without a barrier membrane in deep intrabony defects; 2) to evaluate the postoperative morbidity and surgical complications; and 3) to preliminarily test the impact of baseline tooth mobility on clinical outcomes. METHODS: This parallel group, randomized, multi-center, controlled clinical trial involved 112 patients in 8 periodontal practices in 4 countries. A deep intrabony defect in each patient was accessed with the simplified papilla preservation flap. In the test defects, a bioabsorbable membrane was positioned. Patients' experiences with the surgical procedure and postoperative period were evaluated with a questionnaire. Clinical outcomes included clinical attachment level (CAL) and probing depth (PD) changes. RESULTS: Complete observations were available for 55 test and 54 control defects. CAL gains at 1 year were 3.5 +/- 2.1 mm in the guided tissue regeneration (GTR) group and 2.6 +/- 1.8 mm in the control group (P = 0.0117). CAL gains > or = 4 mm were observed in 50.9% of GTR sites and 33.3% of control sites. A significant center effect of 2.1 mm was observed (P= 0.01). Initial PD (P= 0.01) and baseline tooth mobility (P= 0.036) were significant covariates. During the procedure, 30.4% of test and 28.6% of controls reported feeling moderate pain, and subjects estimated the hardship of the procedure at 24 +/- 25 visual analog scale (VAS) units in the test group, and at 22 +/- 23 VAS in controls. In terms of the investigated outcomes, differences between test and control groups were not statistically significant. Among the postoperative complications, edema was most prevalent at week 1, and more frequently associated with the test treatment (P= 0.01). In the test group, 53.6% of membranes were exposed at week 3. CONCLUSIONS: The present study further supports the added benefits of guided tissue regeneration with respect to access flap alone in the treatment of deep intrabony defects, as well as the general efficacy of GTR in different clinical settings. Furthermore, our study indicates a possible influence of baseline tooth mobility on clinical outcomes.

Absorbable Implants↗

PubMed2001

How can we best read exhaled nitric oxide flow curves in asthmatic children?

Orally exhaled nitric oxide (NO) levels are increased in children with asthma and thought to reflect the local inflammatory events in the airways. NO production in the lower respiratory airway is reflected in the plateau values of the NO curve, recorded while the patient is performing a slow vital capacity manoeuvre. In young patients, however, plateau values may be difficult to obtain, because the slow vital capacity manoeuvre is often terminated prematurely. In the present study, 60 steroid-naive atopic asthmatic children and 17 normal age-matched controls were asked to perform a slow vital capacity manoeuvre, during which fractional exhaled NO (FEno) levels were measured and evaluated as: a) FEno plateau levels of last part of exhalation (NO plateau); b) FEno peak values, c) area under the FEno curve (AUC). Thirteen out of the 60 steroidnaive patients were reevaluated after a short course of inhaled corticosteroid treatment. Independently of the type of data analysis, FEno values of asthmatics were significantly higher than those observed in normal controls (P < 0.001, each comparison). In addition, possibly because of upper airway NO contamination, FEno peak values were significantly higher than FEno plateau levels in asthmatic patients and in control subjects (P < 0.001, each comparison). Both in asthmatics and controls, highly positive correlations were observed between: a) FEno plateau and peak values (r > 0.7, P < 0.01, each correlation), b) FEno plateau and AUC values (r > 0.7, P < 0.01, each correlation) and c) FEno peak and AUC values (r > 0.9, P < 0.001, each correlation). In asthmatic patients, the three types of data analysis were equally sensitive in detecting the decrease in FEno levels induced by inhaled steroid therapy (P < 0.05, each comparison), with a good correlation between the three data analyses (r > 0.5, P < 0.05, each correlation). Thus, although quantitatively different, comparable data reflecting airway inflammation can be obtained evaluating FEno plateau, FEno peak, and area under the curve, on account of possible upper airway contamination in FEno peak, FEno plateau should be preferred to measure lower airway NO production.

Adolescent↗

PubMed2001

Severe and near-fatal asthma in children and adolescents.

Near-fatal asthma attacks occur rather frequently in asthmatic patients during childhood and adolescence. Major risk factors appear to be the severity and/or treatment difficulties, which may be related to the characteristics of the disease but also to mistaken or delayed diagnosis, poor compliance to treatment, and psychosocial problems. Indeed, difficult-to-control asthma symptoms can be caused by other disorders mimicking asthma, by unidentified exacerbating factors, by low compliance with the prescribed therapy, by inability to use the devices correctly (metered-dose inhalers, dry powder inhalers, nebulizers) and by low perceptiveness of airway obstruction. Children and adolescents with severe, difficult-to-treat asthma should receive specialist assessment and follow-up. Pharmacologic intervention should be combined with a detailed education and action plan, designed to get the disease under control but also to meet patient' and parents desires.

Adolescent↗

PubMed2000

Elastic recoil of coronary stents: a comparative analysis.

Minimum elastic recoil (ER) has became an essential feature of new coronary stents when deployed in artheromatous lesions of various morphologies. The ER of coronary stent might be an important component of 6-month restenosis rate by minimizing the luminal loss. We evaluated the intrinsic ER of 23 coronary stents with a mechanical test bench. The amount of ER for one size of stent (3.0 mm) was quantified using a 3D optical contactless machine (Smartscope MVP, Rochester, NY). The stents were expanded on their own balloon for the precrimped stents; the uncrimped stents were expended using identical 3.0-mm balloons. Two types of measurements were done without exterior stress and with a 0.2-bar exterior stress, directly on the stent at the end of balloon expansion, immediately after balloon deflation, and then 30 min, 60 min, and 120 min after. ER ranged from 1.54%+/-0.81% (Bestent BES 15) to 16.51%+/-2.89% (Paragon stent) without stress (P<0.01) and from 2.35%+/-1.14% (Bestent BES 15) to 18.34%+/-2.41% (Cook GR2) under 0.2-bar pressure (P<0.0001). Furthermore, there was a significant reduction between the mean result of tubular stents (TS) and coil stents (CS). The results of in vitro mechanical tests may confirm strongly the interest of a minimum ER in the prevention of the 6-month restenosis.

Angioplasty, Balloon, Coronary↗

PubMed2000

Bronchoalveolar lavage and esophageal pH monitoring data in children with "difficult to treat" respiratory symptoms.

Gastroesophageal reflux (GER) may be associated with chronic or recurrent asthma-like symptoms secondary to bronchoconstrictor reflexes and/or inhalation of gastric content. The presence of lipid-laden alveolar macrophages has been proposed as an index to establish the degree of gastric aspiration. We evaluated 20 children with "difficult to treat" respiratory symptoms and a clinical history suggestive of GER. All children underwent 24-hr esophageal pH monitoring (pHm) and fiberoptic bronchoscopy with bronchoalveolar lavage (BAL). The amount of lipid per single macrophage was determined by a semiquantitative method, using fluorescence microscopy to detect Nile-Red-stained BAL cells and calculating a lipid-laden macrophage index (LLMI). Eleven children had positive pHm recordings, suggesting the presence of GER (pH-positive patients), and 9 had negative pHm records (pH-negative patients). The pH-positive patients had higher percentages of neutrophils and higher LLMI than the pH-negative children (P < 0.05). There were no correlations between the pHm records and either % BAL neutrophils or LLMI in pH-positive or pH-negative patients (P > 0.05; each correlation). In contrast, a single correlation was found between % BAL neuytrophils and LLMI, both in the pH-positive and in the pH-negative patients (r = 0.72, P = 0.02 and r = 0.71, P = 0.04, respectively). These data demonstrate that a significant proportion of pH-positive patients with respiratory symptoms have BAL abnormalities that suggest airway inflammation and gastric content aspiration. However, the intensity of GER as indicated by pH monitoring does not correspond with BAL data in all patients.

Bronchoalveolar Lavage↗

PubMed2000

Inhibition of eosinophil transepithelial migration and downregulation of adhesion molecule expression on eosinophils and airway epithelial cells induced by budesonide.

In asthma, eosinophil migration through the bronchial mucosa is mediated by the expression of surface molecules on eosinophils and airway epithelial cells. To characterize the activity of budesonide on eosinophil transepithelial migration, blood eosinophils were isolated from atopic asthmatic subjects and human bronchial epithelial cells (HBECs) from surgically resected bronchi. In the presence of different concentrations of budesonide (0.1-100 nM), we tested: a) eosinophil migration induced by C5a through HBEC monolayers; b) ICAM-1 expression on HBECs, stimulated with C5a and c) LFA-1 and Mac-1 expression on eosinophils, stimulated with C5a or with ah-CD23 mabs plus GM-CSF. Eosinophils showed a remarkable chemotactic response to C5a (P<0.001), that was effectively down-regulated by the presence in the chemotactic chambers of budesonide at all the concentrations tested (P<0.05). A weaker, but still present, inhibitory activity on cell locomotion was observed when HBECs or eosinophils were preincubated with budesonide before the chemotaxis assay, which was performed in absence of the drug. Preincubation of the cells with different concentrations of budesonide was also effective in down-regulating the C5a-induced ICAM-1 expression on HBECs and the ah-CD23 and GM-CSF-induced LFA-1 and Mac-1 expression on eosinophils. Thus, budesonide-induced down-regulation of eosinophil migration through airway epithelial cells is associated with, and possibly partially dependent on inhibition of adhesion molecule expression on both cell types.

Adolescent↗

PubMed2000

Multiple radiculopathy of the lower limbs in a cancer patient with meningeal carcinomatosis.

Meningeal carcinomatosis occurs in 1%-5% of patients with breast cancer. Early diagnosis and aggressive treatment of neurologic involvement are important factors of prognosis. We report a case of a 52-year-old woman who was affected by bilateral breast carcinoma treated with surgery and chemotherapy. Six years after she had become asymptomatic, X-rays showed lumbar spine metastases which were treated with radiotherapy. After 1 year she began to suffer from lower limb paresthesias, unsteadiness and unstable gait. Clinical examination showed lower limb sensory ataxia with lack of knee and ankle reflexes, and hypopallesthesia from the iliac spine to the foot. Spinal magnetic resonance imaging (MRI) with contrast agent revealed no medullar compression. Electromyography disclosed bilateral involvement of L4-L5-S1 roots and corresponding paraspinal muscles. Sensory and motor conductions were normal. Cerebrospinal fluid (CSF) examination showed the presence of neoplastic cells, confirming the diagnosis of meningeal carcinomatosis. Our patient underwent 9 cycles of intrathecal methotrexate therapy (25 mg/cycle) with improvement of ataxia and relief of paresthesias. One year later, CSF examination is still negative. We point out the importance of electrodiagnostic studies and CSF examination in the early documentation of root involvement in cancer patients, when computed tomography, MRI and myelography are normal. Early diagnosis may lead to effective therapy which prolongs survival.

Antimetabolites, Antineoplastic↗

PubMed2000

Unprotected left main coronary artery stenting: immediate and medium-term outcomes of 140 elective procedures.

OBJECTIVES: We sought to evaluate immediate and late outcomes after stenting for left main coronary artery (LMCA) stenosis. BACKGROUND: Conventional percutaneous transluminal coronary angioplasty (PTCA), for which coronary artery bypass grafting (CABG) has been the gold standard therapy for years, has yielded poor results in unprotected LMCA lesions. The development of coronary stents, together with their dramatic patency improvement provided by new antiplatelet regimens and their validation against restenosis, warrants a reappraisal of angioplasty in LMCA stenosis. METHODS: From January 1993 to September 1998, 140 consecutive unselected patients with unprotected LMCA stenosis underwent elective stenting. Group I included 47 high-CABG-risk patients, and group II included 93 low-CABG-risk patients. Ticlopidine without aspirin was routinely started at least 72 h before the procedure and continued for one month. Patients were reevaluated monthly. A follow-up angiography was requested after six months. RESULTS: The procedure success rate was 100%. One-month mortality was 9% (4/47) in group I and 0% in group II. A follow-up angiography was obtained in 82% of cases, and target lesion revascularization was required in 17.4%. One-year actuarial survival was 89% in the first 29 group I patients and 97.5% in the first 63 group II patients. CONCLUSIONS: Stenting of unprotected LMCA stenosis provided excellent immediate results, particularly in good CABG candidates. Medium-term results were good, with a restenosis rate of 23%, similar to that seen after stenting at other coronary sites. Stenting deserves to be considered a safe and effective alternative to CABG in institutions performing large numbers of PTCAs.

Adult↗

PubMed2000

In childhood asthma the degree of allergen-induced T-lymphocyte proliferation is related to serum IgE levels and to blood eosinophilia.

OBJECTIVE: To investigate whether the state of activation of circulating T-cells in childhood asthma could be related to serum IgE levels and/or to blood eosinophilia. METHODS: Seventeen atopic asthmatic children, sensitized to Dermatophagoides pteronyssinus (Der p), in stable condition at the time of the study and 15 sex-matched and age-matched controls were studied. The expression of activation surface markers (HLA-DR and CD25) on peripheral blood mononuclear cells (PBMCs) was tested by monoclonal antibodies and FACS analysis, while the PBMC proliferative response to Der p antigens was measured by tritiated thymidine (3HTdR) incorporation. RESULTS: As compared to controls, atopic children showed higher eosinophil counts (P < .01), similar lymphocyte counts (P > .1, each comparison) but higher proportion of HLA-DR+ and CD25+ T-lymphocytes (P < .05, each comparison). A significant Der p allergen-induced PBMC proliferation was observed in atopic children (P < .01) but not in controls (P > .1). Both in controls and in atopic children, no correlations were found between lymphocyte counts and eosinophil counts or total or allergen-specific IgE levels (P > .1, each comparison). In contrast, weak correlations were detected between the degree of allergen-induced PBMC proliferation and: a) allergen-specific IgE levels in serum (P < .05) and b) eosinophil counts (P < .05). CONCLUSION: These data support the concept that the degree of activation of allergen-specific T-lymphocytes in blood may reflect the intensity of allergic sensitization in childhood asthma.

Allergens↗

PubMed2000

Comparison of treatments of infrabony defects with enamel matrix derivative, guided tissue regeneration with a nonresorbable membrane and Widman modified flap. A pilot study.

BACKGROUND, AIMS: The purpose of the present study was to compare the efficacy of 3 different surgical procedures in the treatment of infrabony defects: guided tissue regeneration (GTR) with non-resorbable membranes, Widman modified flap (WMF) and enamel matrix derivative (EMD). METHOD: 30 patients with an infrabony component > or = 4 mm were selected. 10 were treated with expanded polytetrafluorethylene (ePTFE (Gore - Tex W. L. Gore and Associates, Flagstaff, AZ, USA)) membranes, 10 with WMF and 10 with enamel matrix derivatives (Emdogain (U Biora AB Malm, Sweden)). The efficacy of each treatment modality was investigated through regression analysis. Probing attachment level (PAL) gain, probing depth (PD) reduction and gingival recession (REC) variation were analyzed. RESULTS: Both Emdogain (enamel matrix derivative) and ePTFE treatment show significant better results as compared to the WMF procedure in which there were no significant changes in PAL gain and PD reduction at baseline and 1 year after surgery. CONCLUSIONS: Results from our analysis suggest that there is no statistically significant difference in PAL gain between GTR and EMD. The clinical outcomes of this pilot study may be of little significance, considering the small number of patients, but it has provided an important base for a controlled clinical trial (with a larger number of patients) which is currently in progress.

Alveolar Bone Loss↗

PubMed2000

Dissociation between exhaled nitric oxide and hyperresponsiveness in children with mild intermittent asthma.

BACKGROUND: Bronchial hyperresponsiveness and airway inflammation are distinctive features of asthma. Evaluation of nitric oxide (NO) levels in expired air have been proposed as a reliable method for assessing the airway inflammatory events in asthmatic subjects. A study was undertaken to evaluate whether airway hyperresponsiveness is related to levels of exhaled NO. METHODS: Thirty two steroid-naive atopic children with mild intermittent asthma of mean (SD) age 11.8 (2.3) years and 28 age matched healthy controls were studied to investigate whether baseline lung function or airway hyperresponsiveness is related to levels of exhaled NO. Airway responsiveness was assessed as the dose of methacholine causing a 20% decrease in forced expiratory volume in one second (FEV(1)) from control (PD(20) methacholine) and exhaled NO levels were measured by chemiluminescence analysis of exhaled air. RESULTS: At baseline asthmatic children had significantly higher NO levels than controls (mean difference 25.87 ppb (95% CI 18.91 to 32.83); p<0.0001) but there were no significant differences in lung function parameters (forced vital capacity (FVC), FEV(1) (% pred), and forced expiratory flows at 25-75% of vital capacity (FEF(25-75%))). In the asthmatic group exhaled NO levels were not significantly correlated with baseline lung function values or PD(20) methacholine. CONCLUSIONS: These results suggest that levels of exhaled NO are not accurate predictors of the degree of airway responsiveness to inhaled methacholine in children with mild intermittent asthma.

Adolescent↗

PubMed2000

Inhibitory activity of fenoterol on Dermatophagoides-, Parietaria-, tetanus-toxoid-, and Candida albicans-stimulated blood mononuclear cells: differences in beta2-adrenoreceptor stimulation but not in cell apoptosis.

beta2-adrenoreceptor agonists have the ability to downregulate in vitro the proliferative response of peripheral blood mononuclear cells (BMCs). This activity could be related to a variety of beta2-adrenoreceptor-mediated functions, including induction of cell apoptosis in activated T-cells. To test this hypothesis, BMCs from atopic subjects, sensitized to house dust mites (Dermatophagoides [Der p]) and/or to Parietaria were incubated with fenoterol (10(-8)-10(-5) M) in the presence of (a) purified allergen extracts (Der p [5 microg/mL] or Parietaria [5 microg/mL]) or (b) antigens (tetanus toxoid [1 microg/mL] or Candida albicans [5 x 10(5) bodies/mL]). The BMC proliferation was assessed by [3H] thymidine incorporation and cell apoptosis was assessed by evaluating DNA fragmentation by a fluorescence technique, using propidium iodide. In cultures stimulated with Der p or with Parietaria, fenoterol induced a dose-dependent inhibition of BMC proliferation, significant also at the lowest concentration tested (10(-8) M) (p < 0.05, each comparison). In contrast, the inhibitory activity of the drug on tetanus-toxoid-stimulated BMCs was significant only at the highest dose tested (10(-5)M) (p < 0.05), whereas no effect was seen when BMCs were stimulated with C. albicans extract (p > 0.05). The different inhibitory efficacy of fenoterol appeared to be related to the degree of activation of beta2-adrenoreceptors on the different BMC populations that responded to the different stimuli. Indeed, in the presence of fenoterol (10(-6) and 10(-5)M), a significant increase in cyclic adenosine monophosphate (cAMP) levels was seen in Der p- or Parietaria-stimulated cells (p < 0.05; each comparison), but not in cell cultures stimulated with tetanus toxoid or with C. albicans extracts (p > 0.05; each comparison). Finally, the percentage of cells with fragmented DNA was lower in cultures stimulated with Der p or Parietaria than in those stimulated with tetanus toxoid or C. albicans, and the presence of fenoterol did not modify cell apoptosis (p > 0.05; each comparison). Thus, the different inhibitory activity of fenoterol on BMCs activated by allergens (Der p or Parietaria) or by antigens (tetanus toxoid or C. albicans) seems to be related to differences in beta2-adrenoreceptor expression and/or function in the different antigen-specific T-cell subsets, but it is not influenced by changes in cell apoptosis.

Adrenergic beta-Agonists↗