Biomedical subjects

R Testi

Publications and source records attributed to R Testi.

At least 37 records · Page 2Linked to original sources

PubMed1999

A double-blind, placebo-controlled comparison of treatment with fluticasone propionate and levocabastine in patients with seasonal allergic rhinitis. FLNCO2 Italian Study Group.

Fluticasone propionate aqueous nasal spray (FPANS) is a topically active glucocorticoid which has been successfully used for the treatment of seasonal allergic rhinitis (SAR). Topical levocabastine is a highly selective H1 antagonist which has been proposed as an alternative treatment of SAR. The purpose of this study was to compare the clinical efficacy of two topical nasal treatments, FPANS and levocabastine, in the treatment of SAR. Additionally, the effect of treatments on nasal inflammation was examined during natural pollen exposure. A group of 288 adolescent and adult patients with at least a 2-year history of SAR to seasonal pollens participated in a multicenter, doubleblind, double-dummy, and placebo-controlled study. Patients were treated with either FPANS 200 microg, once daily (n = 97), or topical levocabastine, 200 microg, given twice daily (n = 96), or matched placebo (n = 95) for a period of 6 weeks, starting from the expected beginning of the pollen season. Clinically relevant pollens included Parietaria, olive, and grass. Assessment of efficacy was based on scores of daily nasal symptoms and on nasal cytology of nasal lavage. Nasal lavage was performed immediately before, during, and at the end of treatment in 39 patients. FPANS significantly increased the percentage of symptom-free days for nasal obstruction on waking and during the day, rhinorrhea, sneezing, and itching. FPANS provided a better control for night and day nasal obstruction (P<0.02 and P<0.01) and rhinorrhea (P<0.01) than levocabas tine. In addition, fewer patients treated with FPANS used rescue medication (P<0.025). The percentage of eosinophils in nasal lavage was reduced only during treatment with FPANS. The results of this study indicate that FPANS 200 microg, once daily, provides a better clinical effect than levocabastine 200 microg, twice daily, in patients with SAR. Unlike levocabastine, FPANS significantly attenuates nasal eosinophilia during pollen exposure, a feature which may explain its therapeutic efficacy.

Adult↗

PubMed1999

Arsenic and all-trans retinoic acid as induction therapy before autograft in a case of relapsed resistant secondary acute promyelocytic leukemia.

Arsenic trioxide has recently been reported to be successful in the treatment of promyelocytic leukemia. Several concerns about the use of this toxic agent are currently reducing its potential clinical use even in severely ill patients. In this report we describe the results achieved by As2O3 with all-trans retinoic acid in a patient suffering from secondary, relapsed, resistant promyelocytic leukemia. Several complications, including sepsis and an extensive area of skin necrosis, did not allow us to treat the patient further with chemotherapy. With As2O3 and ATRA therapy, the patient obtained a complete molecular remission without any significant toxicity and, subsequently, it was possible to perform a bone marrow autograft in a state of complete remission.

Adult↗

PubMed1999

Effect of a single dose of salmeterol on the increase in airway eosinophils induced by allergen challenge in asthmatic subjects.

BACKGROUND: The long acting beta2 agonist salmeterol is very effective in preventing asthmatic responses to specific stimuli, and this effect could theoretically be due to some anti-inflammatory property in addition to bronchodilator property. METHODS: The protective effect of a single dose of salmeterol (50 microg) on allergen induced early and late responses and on the associated airway inflammation was investigated in a double blind, placebo controlled, crossover study in 11 atopic asthmatic subjects. Eosinophil percentages and concentrations of eosinophil cationic protein (ECP) in peripheral blood and in hypertonic saline induced sputum were measured 24 hours after allergen inhalation. RESULTS: Salmeterol effectively inhibited both early and late asthmatic responses in comparison with placebo. Salmeterol also inhibited the increase in the percentage of eosinophils in the sputum 24 hours after allergen inhalation (median (range) baseline 6% (1-36), after placebo 31% (5-75), after salmeterol 12% (1-63)). However, the increase in both sputum and serum ECP concentrations 24 hours after allergen challenge was not affected by pretreatment with salmeterol. CONCLUSIONS: A single dose of salmeterol inhibits the allergen induced airway responses and the increase in sputum eosinophils after allergen challenge.

Adolescent↗

PubMed1999

Inhaled beclomethasone dipropionate reverts tolerance to the protective effect of salmeterol on allergen challenge.

STUDY OBJECTIVE: One week of regular treatment with salmeterol can induce tolerance to the protective effect of a beta2-agonist on early airway response to allergen (EAR). The objective was to assess whether inhaled corticosteroids revert tolerance to salmeterol. STUDY DESIGN: The study had a randomized, double-blind, placebo-controlled design. PATIENTS AND METHODS: Twelve subjects with mild allergic asthma and positive result of specific bronchial provocation test (sBPT) to allergen underwent three sBPTs, separated by 1 week. sBPT was done in all subjects after a single dose (T1) and after 1 week of regular treatment with inhaled salmeterol (50 microg bid) (T2) in order to induce tolerance. Subjects were then randomized to receive either the same dose of salmeterol + beclomethasone dipropionate (BDP, 500 microg bid) (group 1, n = 6) or placebo + BDP (group 2, n = 6) for 1 week before sBPT (T3). RESULTS: After a single dose of salmeterol (T1), all subjects were protected against EAR, whereas after 1 week of regular treatment, the protective effect of salmeterol was totally or partially lost (T2). Maximum FEV1 percent fall (MaxdeltaFEV1%) after allergen inhalation was significantly higher at T2 than at T1. All subjects except one of group 1 were protected against EAR after salmeterol + BDP (T3), and MaxdeltaFEV1% at T3 (median, 12%; range, 4 to 6%) was significantly lower than T2 (median, 22%; range, 12 to 43%; p < 0.05 by Wilcoxon test). Subjects of group 2 did not show any significant protection against EAR after placebo + BDP treatment (T3) MaxdeltaFEV1% at T2 (median, 31%; range, 9 to 40%) and T3 (median, 31%; range, 3 to 42%; not significant). CONCLUSIONS: In conclusion, the addition of inhaled BDP partially restored the bronchoprotective effect of salmeterol on allergen challenge that was lost after 1 week of regular treatment with salmeterol alone. This ability of BDP in reverting tolerance cannot be ascribed to a direct effect of corticosteroids per se on allergen challenge in this group of asthmatics.

Administration, Inhalation↗

PubMed1998

Caspases mediate retinoic acid-induced degradation of the acute promyelocytic leukemia PML/RARalpha fusion protein.

All-trans-retinoic acid (RA) treatment induces morphological remission in acute promyelocytic leukemia (APL) patients carrying the t(15;17) and expressing the PML/RARalpha product by inducing terminal differentiation of the leukemic clone. RA treatment induces downregulation of PML/RARalpha and reorganization of the PML-nuclear bodies. These events have been proposed to be essential for the induction of APL cell differentiation by RA. Here, we show that in the APL-derived NB4 cell line as well as in myeloid precursor U937 cells expressing the PML/RARalpha (U937/PR9) and in blasts from APL patients, the PML/RARalpha fusion protein is cleaved by a caspase 3-like activity induced by RA treatment. In fact, a caspase 3-like activity is detectable in PML/RARalpha expressing cells after RA treatment, and selective caspase inhibitor peptides are able to prevent the RA-induced degradation of the fusion protein in vivo and in vitro. Using recombinant caspases and PML/RARalpha deletion mutants we mapped a caspase 3 cleavage site (Asp 522) within the alpha-helix region of the PML component of the fusion protein. The extent of PML/RARalpha cleavage directly correlates with the ability of RA to restore the normal PML nuclear bodies (NBs) pattern. However, RA-induced differentiation is not prevented by the persistence of the fusion product and occurs in the absence of normally structured PML NBs. These results indicate that PML/RARalpha is directly involved in conferring RA sensitivity of APL cells and that the RA-induced reassembly of PML NBs is the consequence of the disappearance of PML/RARalpha.

Antineoplastic Agents↗

PubMed1998

Acidic sphingomyelinase (ASM) is necessary for fas-induced GD3 ganglioside accumulation and efficient apoptosis of lymphoid cells.

Ceramides deriving from sphingomyelin hydrolysis are important mediators of apoptotic signals originating from Fas (APO-1/CD95). However, definitive evidence for the role played by individual sphingomyelinases is still lacking. We have analyzed lymphoblastoid cell lines derived from patients affected by Niemann Pick disease (NPD), an autosomal recessive disorder caused by loss-of-function mutations within the acidic sphingomyelinase (ASM) gene. NPD lymphoblasts, which display normal neutral sphingomyelinase activity, fail to activate ASM in response to Fas cross-linking, unlike normal lymphoblasts. NPD lymphoblasts also fail to accumulate GD3 ganglioside, a downstream mediator of ceramide-induced cell death (De Maria, R., L. Lenti, F. Malisan, F. D'Agostino, B. Tomassini, A. Zeuner, M.R. Rippo, R. Testi. 1997. Science. 277:1652-1655), and display a substantially inefficient apoptosis after Fas cross-linking. Inefficient apoptosis is due to lack of ASM activity, because proximal signaling from Fas in NPD lymphoblasts is not impaired and apoptosis can be efficiently triggered by passing the ASM defect with exogenous ceramides. Moreover, mannose receptor-mediated transfer of ASM into NPD lymphoblasts rescues their ability to transiently activate ASM, accumulate GD3, and rapidly undergo apoptosis after Fas cross-linking. These results provide definitive genetic evidence for the role of ASM in the progression of apoptotic signals originating from Fas.

Animals↗

PubMed1998

Fas-FasL interactions: a common pathogenetic mechanism in organ-specific autoimmunity.

Organ-specific autoimmunity is characterized by the accelerated loss of selected cell types, resulting in specific tissue destruction and disease. The role of different genetic or environmental factors in initiating the autoimmune reactivity is still unclear. However, novel mechanisms responsible for tissue destruction have recently been revealed. Here, Ruggero De Maria and Roberto Testi propose that Fas ligand may represent a common weapon during the destructive phase of organ-specific autoimmunity.

Animals↗

PubMed1998

Heat shock protein 70 upregulation is related to HLA-DR expression in bronchial asthma. Effects of inhaled glucocorticoids.

BACKGROUND AND OBJECTIVE: Antigen processing determines the production of peptides from antigens - including allergens - and their binding to class II major histocompatibility complex molecules, that stimulate T-cell responses. Heat shock protein (hsp) 70 are recognized to have a role in chaperoning antigenic peptides and in facilitating class II peptide assembly. We studied the HLA-DR and hsp70 expression on BAL cells and bronchial biopsies from asthmatics, as well as the effect of low dose fluticasone propionate treatment. METHODS: Twenty-three asthmatics and eight normal subjects were selected. In each subject BAL and bronchial biopsies were performed. Eighteen out of 23 asthmatics, underwent the second bronchoscopy after 6 weeks of low dose inhaled fluticasone propionate treatment (250 microg b.d.) in a placebo-controlled double-blind study. BAL fluid and biopsies were processed to evaluate HLA-DR and hsp70 expression by immunochemistry methods. RESULTS: Hsp70 and HLA-DR upregulation was present on professional and non-professional antigen presenting cells (APCs). In asthmatics, the hsp70 and HLA-DR expression was higher in BAL (hsp70 P<0.001, HLA-DR P<0.001) and bronchial epithelium (hsp70 P<0.001, HLA-DR P<0.001) when compared with controls. We also observed a significant correlation between hsp70 and HLA-DR expression in BAL (P<0.005) and epithelium (P<0.001). Fluticasone propionate treatment down-regulated the hsp70 and HLA-DR expression in BAL (hsp70 P < 0.001, HLA-DR P < 0.05) and bronchial epithelium (hsp70 P < 0.05, HLA-DR P < 0.05). A serial section comparison study showed that CD1a+ cells and macrophages were positive for both hsp70 and HLA-DR in the submucosa. CONCLUSIONS: Our results support the hypothesis that hsp70 over-expression implies a potential role for these proteins in antigen processing and/or presentation resulting in an increased activity of APCs, which is essential for the initiation and modulation of the asthmatic immune response in chronic asthma. Fluticasone propionate induces downregulation of HLA-DR and hsp70 molecules thus regulating inflammation by affecting key mechanisms of the allergic response.

Administration, Inhalation↗

PubMed1998

Salmeterol enhances the inhibitory activity of dexamethasone on allergen-induced blood mononuclear cell activation.

The possibility that salmeterol could interfere with the inhibitory effect of glucocorticosteroids on allergen-induced activation of leukocytes was assessed in cultures of human blood mononuclear cells (BMCs). BMCs, recovered from 27 patients (21 +/- 4 years of age) sensitized to Dermatophagoides pteronyssinus (Der p), were incubated with a purified Der p extract (10 micrograms/ml) for 7 days in the presence of salmeterol (10(-8) and 10(-7) M) and/or dexamethasone (10(-10) and 10(-9) M). BMC proliferation and cytokine release were respectively tested by [3H]thymidine incorporation and EASIA. Stimulation with Der p extract induced a significant BMC proliferation (Der p 18.7 +/- 1.9 cpm x 10(3), control 1.8 +/- 0.3 cpm x 10(3), p < 0.01) which was significantly inhibited both by salmeterol and dexamethasone (p < 0.05, each comparison). The inhibition of BMC proliferation induced by dexamethasone (10(-9) M) was significantly enhanced by salmeterol 10(-7) M (p < 0.05). Evaluation of cytokine levels in BMC supernatants showed that Der p extract significantly increased the release of granulocyte-macrophage colony-stimulating factor (GM-CSF), interferon-gamma (IFN-gamma), tumor necrosis factor-alpha (TNF-alpha), interleukin (IL)-1 beta and IL-2 (p < 0.001, each comparison). Salmeterol (10(-7) M) or dexamethasone (10(-9) M) induced a similar, statistically significant, downregulation of GM-CSF release (p < 0.05, each comparison) and induced a slight, not significant, decrease in the production of IFN-gamma, TNF-alpha, IL-1 beta and IL-2 (p > 0.05 each comparison). Interestingly, salmeterol (10(-7) M) significantly enhanced the inhibitory activity of dexamethasone (10(-9) M) on the release of GM-CSF, TNF-alpha, IL-1 beta and IL-2 (p < 0.05, each comparison) but not of IFN-gamma (p > 0.05). Thus beta 2-adrenoceptors may enhance the inhibitory activity of low doses of corticosteroids on allergen-induced BMC activation.

Adrenergic beta-Agonists↗

PubMed1997

Nitric oxide primes pancreatic beta cells for Fas-mediated destruction in insulin-dependent diabetes mellitus.

Fas is an apoptosis-inducing surface receptor involved in controlling tissue homeostasis and function at multiple sites. Here we show that beta cells from the pancreata of newly diagnosed insulin-dependent diabetes mellitus (IDDM) patients express Fas and show extensive apoptosis among those cells located in proximity to Fas ligand-expressing T lymphocytes infiltrating the IDDM islets. Normal human pancreatic beta cells that do not constitutively express Fas, become strongly Fas positive after interleuken (IL)-1beta exposure, and are then susceptible to Fas-mediated apoptosis. NG-monomethyl-L-arginine, an inhibitor of nitric oxide (NO) synthase, prevents IL-1beta-induced Fas expression, whereas the NO donors sodium nitroprusside and nitric oxide releasing compound (NOC)-18, induce functional Fas expression in normal pancreatic beta cells. These findings suggest that NO-mediated upregulation of Fas contributes to pancreatic beta cell damage in IDDM.

Adult↗

PubMed1997

Requirement for GD3 ganglioside in CD95- and ceramide-induced apoptosis.

Gangliosides participate in development and tissue differentiation. Cross-linking of the apoptosis-inducing CD95 protein (also called Fas or APO-1) in lymphoid and myeloid tumor cells triggered GD3 ganglioside synthesis and transient accumulation. CD95-induced GD3 accumulation depended on integral receptor "death domains" and on activation of a family of cysteine proteases called caspases. Cell-permeating ceramides, which are potent inducers of apoptosis, also triggered GD3 synthesis. GD3 disrupted mitochondrial transmembrane potential (DeltaPsim), and induced apoptosis, in a caspase-independent fashion. Transient overexpression of the GD3 synthase gene directly triggered apoptosis. Pharmacological inhibition of GD3 synthesis and exposure to GD3 synthase antisense oligodeoxynucleotides prevented CD95-induced apoptosis. Thus, GD3 ganglioside mediates the propagation of CD95-generated apoptotic signals in hematopoietic cells.

Apoptosis↗

PubMed1997

The interaction of sperm cells with exogenous DNA: a role of CD4 and major histocompatibility complex class II molecules.

Mouse epidydimal sperm cells have the spontaneous ability to take up exogenous DNA, a part of which is further internalized into nuclei. We report here that sperm cells from MHC class II knockout mice have a reduced ability to bind DNA compared to sperm cells from wild-type animals. Spermatozoa from CD4 knockout mice are instead fully capable of binding exogenous DNA, yet lose the ability to further internalize it. MHC class II expression was not detected on sperm heads using monoclonal antibodies. In contrast, CD4 molecules were found on sperm heads by both immunofluorescence and Western blot analysis. Moreover, we show that nuclear internalization of exogenous DNA was prevented in wild-type sperm cells preincubated with anti-CD4 mAbs. These results support the conclusion that CD4 and MHC class II molecules play distinct roles in the process of sperm/DNA interaction: though not present in mature sperm cells, MHC class II expression appears to be required during spermatogenesis to produce sperm cells capable of taking up foreign DNA, while CD4 molecules present on sperm cells mediate the nuclear internalization of sperm-bound DNA.

Animals↗

PubMed1997

Fas-induced changes in cdc2 and cdk2 kinase activity are not sufficient for triggering apoptosis in HUT-78 cells.

Recent evidence suggested a role for the cell cycle dependent kinases cdc2 and cdk2 in apoptosis. An important mechanism by which many cell types could undergo apoptosis is through the activation of the Fas molecule on the cell membrane. To investigate whether Fas-induced cell death activated cdc2 and cdk2 kinases inappropriately, the human T lymphoma cells HUT-78, which express a high copy number of Fas, and two other previously characterized subclones of the same cell line which express mutant, cell death-deficient dominant-negative forms of Fas, were Fas-challenged and the changes in cdc2 and cdk2 kinase activity monitored. In both wild-type and Fas-mutated HUT-78 cells, apoptosis was associated simultaneously with decreased cdc2 and increased cdk2 activity. This association suggested that changes in cdc2 and cdk2 kinase activity are secondary events in cell death mediated by Fas.

Apoptosis↗

PubMed1997

Potential involvement of Fas and its ligand in the pathogenesis of Hashimoto's thyroiditis.

The mechanisms responsible for thyrocyte destruction in Hashimoto's thyroiditis (HT) are poorly understood. Thyrocytes from HT glands, but not from nonautoimmune thyroids, expressed Fas. Interleukin-1beta (IL-1beta), abundantly produced in HT glands, induced Fas expression in normal thyrocytes, and cross-linking of Fas resulted in massive thyrocyte apoptosis. The ligand for Fas (FasL) was shown to be constitutively expressed both in normal and HT thyrocytes and was able to kill Fas-sensitive targets. Exposure to IL-1beta induced thyrocyte apoptosis, which was prevented by antibodies that block Fas, suggesting that IL-1beta-induced Fas expression serves as a limiting factor for thyrocyte destruction. Thus, Fas-FasL interactions among HT thyrocytes may contribute to clinical hypothyroidism.

Antibodies, Monoclonal↗

PubMed1997

Salmeterol inhibits the allergen-induced mononuclear cell proliferation and downregulates GM-CSF release and HLA-DR expression by monocytes.

beta 2-adrenoceptor agonists are known to attenuate several functions of human mononuclear cells in response to activation. Since monocytes and lymphocytes play a major pathogenetic role in allergic asthma, this study was designed to evaluate the hypothesis that salmeterol, a beta 2-adrenoceptor agonist with a long duration of action, could inhibit in vitro the allergen-induced activation of blood mononuclear cells (BMCs). BMCs were collected from subjects sensitized to Dermatophagoides pteronyssinus (Der p) and incubated with a purified Der p allergen extract to evaluate the ability of salmeterol to downregulate; (a) BMC proliferation; (b) IL-2 receptors (r) and HLA-DR surface antigen (ag) expression; (c) cytokine release. Der p induced a significant BMC proliferation (P < 0.01), associated with increased expression of HLA-DRag and IL-2r (P < 0.05) and with enhanced release of IL-2, GM-CSF, IL-1 beta, TNF-alpha and IFN-gamma (P < 0.01, each comparison). Salmeterol (10(-8)-10(-6) M) significantly inhibited, in a dose dependent manner, the Der p-induced BMC proliferation, reducing (at 10(-7) M) HLA-DRag expression on monocytes and GM-CSF release (P < 0.05, each comparison). These data demonstrate that beta 2-adrenoceptor-mediated suppression of allergen-induced BMC activation is associated with inhibition of cytokine release and of surface molecule expression, which are involved in the interaction between T-lymphocytes and antigen-presenting cells.

Adrenergic beta-Agonists↗

PubMed1997

CD95 and CD95-ligand expression in endocrine pancreas of NOD, NOR and BALB/c mice.

The non-obese diabetic (NOD) mouse is widely used to study the pathogenesis of insulin-dependent diabetes mellitus. However, the mechanisms responsible for beta-cell destruction, in this model, are still poorly defined. The CD95/CD95L system among other effector systems has been implicated in beta-cell death. In this study we investigated in NOD, non-obese resistant (NOR) and Balb/c mice the expression of CD95 and CD95L in alpha and beta pancreatic cells by immunohistochemistry and immunofluorescence. We demonstrate that alpha cells in the islets of Langherans constitutively express CD95L forming a natural shield around beta cells.

Animals↗

PubMed1997

Effect of short-term treatment with low-dose inhaled fluticasone propionate on airway inflammation and remodeling in mild asthma: a placebo-controlled study.

In a double-blind, parallel-group study, we examined the effect of short-term treatment with inhaled fluticasone propionate (FP) in a group of 20 nonsmoking asthmatic patients who required only beta2-agonists to control their symptoms. We administered FP (250 microg twice daily) or matched placebo for 6 wk. Methacholine challenge was performed before treatment, after 3 wk, and at the end of treatment. Each patient underwent bronchoscopy with bronchoalveolar lavage (BAL) and bronchial biopsy before and after treatment. Eight patients in the placebo group and nine patients in the FP group completed the study. Bronchial responsiveness to methacholine decreased significantly only after 6 wk of treatment with FP (p < 0.05). When we compared the FP group with the placebo group, we observed a significant decrease only in the number of cells expressing intracellular adhesion molecule-1 (ICAM-1) and MAC-1 (p < 0.04 and p < 0.03, respectively). Moreover, we saw that the tryptase level in BAL decreased (p < 0.001), whereas the eosinophil cationic protein (ECP) level did not change significantly. Additionally, the number of eosinophils and mast cells in the lamina propria in bronchial biopsies specimens was significantly smaller in the FP group than in the placebo group (p < 0.02 and p < 0.01, respectively). Additionally, in the FP group, we found that basement-membrane thickness was significantly decreased when compared with that of the placebo group (p < 0.05). In conclusion, our results show that short-term treatment with low-dose FP reduces inflammatory cell infiltration into the lamina propria in bronchial biopsy specimens. Moreover, short-term low-dose FP treatment might control the intensity of airway remodeling in mild asthma.

Administration, Inhalation↗

PubMed1996

Ceramide inhibits antigen uptake and presentation by dendritic cells.

Ceramides are intramembrane diffusible mediators involved in transducing signals originated from a variety of cell surface receptors. Different adaptive and differentiative cellular responses, including apoptotic cell death, use ceramide-mediated pathways as an essential part of the program. Here, we show that human dendritic cells respond to CD40 ligand, as well as to tumor necrosis factor-alpha and IL-1 beta, with intracellular ceramide accumulation, as they are induced to differentiate. Dendritic cells down-modulate their capacity to take up soluble antigens in response to exogenously added or endogenously produced ceramides. This is followed by an impairment in presenting soluble antigens to specific T cell clones, while cell viability and the capacity to stimulate allogeneic responses or to present immunogenic peptides is fully preserved. Thus, ceramide-mediated pathways initiated by different cytokines can actively modulate professional antigen-presenting cell function and antigen-specific immune responses.

Antigen-Presenting Cells↗