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M Vitale

Publications and source records attributed to M Vitale.

At least 19 recordsLinked to original sources
PubMed2006

Measuring, modelling and testing ozone exposure, flux and effects on vegetation in southern European conditions--what does not work? A review from Italy.

Ozone (O3) exposure at Italian background sites exceeds UN/ECE concentration-based critical levels (CLe(c)), if expressed in terms of AOT40. Yet the occurrence of adverse effects of O3 on forests and crops is controversial. Possible reasons include (i) ability of response indicators to provide an unbiased estimate of O3 effects, (ii) setting of current CLe(c) in terms of cut-off value and accumulation level, (iii) response functions adopted to infer a critical level, (iv) environmental limitation to O3 uptake and (v) inherent characteristics of Mediterranean vegetation. In particular, the two latter points suggest that critical levels based on accumulated stomatal flux (CLe(f)) can be a better predictor of O3 risk than CLe(c). While this concept is largely acknowledged, a number of factors may limit its applicability for routine monitoring. This paper reviews levels, uptake and vegetation response to O3 in Italy over recent years to discuss value, uncertainty and feasibility of different approaches to risk assessment.

Crops, Agricultural↗
PubMed2006

Diagnosis and outcome of renal function in patients with renal artery stenosis: which role have color Doppler sonography and magnetic resonance angiography?

AIM: Minimally invasive diagnostic techniques would be useful in the preoperative diagnosis of patients with hypertension and ischemic renal disease. The aim of our study was to compare color Doppler sonography (CDS), and magnetic resonance angiography (MRA) with the reference standard, digital subtraction angiography (DSA), in the diagnosis of renal artery stenosis. METHODS: Thirty-nine patients with arterial hypertension and monolateral or bilateral renal artery stenosis documented by CDS underwent renal artery MRA and then DSA during corrective percutaneous transluminal angioplasty. CDS and MRA scans were evaluated by 3 independent observers who studied 78 main renal arteries. Stenosis of 70% or more were regarded as significant. Sensitivity, specificity, positive and negative predictive values and two-sided 95% confidence intervals of CDS and MRA for the detection of significant renal artery stenosis were calculated. The statistical significance of the differences in sensitivities between CDS and MRA was assessed by means of the kappa test (< or =1). RESULTS: CDS and MRA, therefore, both achieved 97.6% sensitivity and 100% specificity for diagnosing stenoses at the origin of the renal artery; CDS yielded 100% sensitivity and 97.1% specificity and MRA 87.5% sensitivity and 98.6% specificity for diagnosing stenosis in the intermediate distal segments. CONCLUSIONS: Statistically significant differences between CDS and MRA in the diagnosis of renal artery stenosis have not been observed. However, according to our experience, CDS is the preferred technique because it also provides useful information about the development of kidney disease before correction.

Aged↗
PubMed2004

TaqMan-based detection of Leishmania infantum DNA using canine samples.

Leishmaniasis is a typical example of a worldwide diffused zoonosis. Geographic distribution depends on the presence of sand fly vectors and animal reservoirs. In Southern Europe, canines are considered the main reservoir of infection, and the phlebotomines are the vectors. In Sicily, as in all Mediterranean areas, sand flies are present almost all year around because the climate permits an uninterrupted lifecycle for the vectors. Visceral leishmaniasis is becoming a real public health concern especially in endemic areas; in fact, it is an opportunistic infection in immunocompromised patients and in HIV-positive subjects. In Italy, the visceral form of the disease is due exclusively to Leishmania infantum ZMON1, and its prevalence is growing. We have developed a highly accurate, reproducible, and sensible real-time polymerase chain reaction (PCR) assay. In a procedure that used a specific couple of primers, a 117-bp fragment was amplified from minicircle kinetoplast DNA (kDNA). The assay was able to detect even a single parasite (200 fg of DNA). In fact, a single parasite contains hundreds of kinetoplast minicircles for each class. We applied a rapid extraction method coupled with the real-time PCR assay. It was not only as sensitive as a conventional PCR assay for detection of Leishmania kDNA, but also more rapid. The assay is useful for the diagnosis of leishmaniasis in dogs and humans, and it facilitates the monitoring of parasite levels during pharmacological treatment.

Animals↗
PubMed2004

The response of human natural killer cells to interleukin-2.

Natural killer cells play a key role in the defence of organisms against virus infections and in the control of tumor onset. Interleukin-2 is a multifunctional inflammatory cytokine able to activate natural killer cells, essentially inducing cell proliferation, lymphokine-activated-killer cell generation and cytokine production. Here we discuss some signaling events generated by interleukin-2 in the cell nucleus of primary human natural killer cells, specifically focusing on the lipid signal transduction and the induction of the cyclic adenosine-5'-monophosphate response element binding protein transcription factor. The implications of these nuclear events in the response of natural killer cells to interleukin-2 are also discussed.

Animals↗
PubMed2004

In memoriam.

Explore the source record for details and available documents.

Anatomy↗
PubMed2003

Identification of a novel bluetongue virus vector species of Culicoides in Sicily.

The vectors of bluetongue virus are certain species of Culicoides biting midges, and in the Mediterranean area Culicoides imicola has long been considered to be the only field vector. In Sicily an entomological and serological surveillance programme has been in operation since the autumn of 2000, which has shown that the prevalence and abundance of C. imicola is lower than in many other Italian regions. Moreover, in 2002, there were outbreaks of bluetongue in the absence of C. imicola, and in these regions bluetongue viral RNA was detected by means of a nested reverse-transcriptase PCR in wild-caught, non-blood-engorged, parous Culicoides pulicaris. Furthermore, bluetongue virus serotype 2 was isolated on five occasions from extracts of non-blood-engorged parous C. pulicaris by using embryonated hens eggs and BHK-21 cells as assay systems. These findings suggest that in parts of Italy and possibly in other areas of Europe, where C. imicola is absent or rare, C. pulicaris may act as a fully competent vector of bluetongue virus.

Animals↗
PubMed2003

Behavior of SaOS-2 cells cultured on different titanium surfaces.

Surface properties may affect the clinical outcome of titanium dental implants. The aim of the present study was to investigate the effects of 3 different titanium surfaces-smooth (S), sandblasted (SB), and titanium plasma-sprayed (TPS)-on proliferation, differentiation, and apoptosis of human osteoblast-like cells, SaOS-2. Cell proliferation was significantly (p < 0.05) higher on the S surface, and synthesis of extracellular matrix proteins was more abundant on TPS and SB than on S surfaces. Analysis of integrin receptors showed a higher expression of alpha2, alpha5, alphaVbeta3, and ss1 on TPS as compared with SB and S surfaces. An increase in alkaline phosphatase activity was detected only on SB and TPS surfaces. Analysis of cell apoptosis did not demonstrate any significant difference among the 3 different surfaces. The results indicate that titanium surface topography affects proliferation and differentiation of osteoblast-like SaOS-2 cells, suggesting that surface properties might be important for bone response around dental implants in vivo.

Alkaline Phosphatase↗
PubMed2002

Heparin-induced thrombocytopenia: detection of antiheparin/PF4 antibodies by means of heparin/PF4-coated beads and flow cytometry.

A total of 70 serum samples from heparin-induced thrombocytopenia (HIT II) patients, non-HIT patients and healthy subjects, respectively, were studied for the presence of antiheparin/PF4 antibodies. Two enzyme-linked immunosorbent assay (ELISA) assays were compared with the particle gel immunoassay (PaGIA). Beads of the PaGIA kit were also used to evaluate the feasibility of flow cytometric detection of antiheparin/PF4 antibodies in patient samples. Experiments have shown that all samples found positive by ELISA and PaGIA, were also positive when analysed by flow cytometry by an indirect test using the high-density particles coated with heparin/PF4 complexes and a second step fluorescein isothiocyanate (FITC) antihuman immunoglobulin (Ig)G reagent. The procedure was easy to perform, repetitive and beads were promptly visualized by physical parameters, with a very low background. In conclusion, the results of this study suggest that flow cytometry is a reliable method for the detection of antiheparin/PF4 antibodies.

Adult↗
PubMed2002

Could an echo contrast agent be helpful in identifying renal artery stenosis?

BACKGROUND: Diagnosis of renal artery stenosis using echo color-Doppler is subjected to several limitations. The aim of this study was to examine if the routine use of a contrast agent could be helpful in identifying renal artery stenosis (RAS). METHODS: We analysed 35 patients affected by RAS using an echo color-Doppler coupled with a contrast agent. All patients presented arterial hypertension, with a good drugs control, and mean serum creatinine of 1.8 mg/dL. All patients previously underwent angiography. RAS was at the origin of the artery in 27 patients, at the intermediate tract in 8. All patients had already been submitted to a basal echo color-Doppler. RESULTS: The contrast agent determined a significant increase in the average colour signal in all the subjects, and a better evaluation of the spectral waveforms, if compared to the basal examination. CONCLUSIONS: The results obtained showed that the contrast agent doesn't improve the diagnosis of RAS, especially in vascular origin stenosis, while it shows a real advantage in the intermediate or distal stenosis which are better visualized.

Adolescent↗
PubMed2001

Control by the endogenous cannabinoid system of ras oncogene-dependent tumor growth.

We investigated the effect of 2-methyl-arachidonyl-2'-fluoro-ethylamide (Met-F-AEA), a stable analog of the endocannabinoid anandamide, on a rat thyroid epithelial cell line (FRTL-5) transformed by the K-ras oncogene, and on epithelial tumors derived from these cells. Met-F-AEA effect in vivo was evaluated in a nude mouse xenograft model, where K-ras-transformed (KiMol) cells were implanted subcutaneously. Met-F-AEA (0.5 mg/kg/dose) induced a drastic reduction in tumor volume. This effect was inhibited by the CB1 receptor antagonist SR141716A (0.7 mg/kg/dose) and was accompanied by a strong reduction of K-ras activity. Accordingly, KiMol cells and tumors express CB1 receptors. Met-F-AEA inhibited (IC50 ~5 mM) the proliferation in vitro and the transition to the S phase of KiMol cells and it reduced K-ras activity; these effects were antagonized by SR141716A. Met-F-AEA cytostatic action was significantly smaller in nontransformed FRTL-5 cells than in KiMol cells. Met-F-AEA treatment exerted opposite effects on the expression of CB1 receptors in KiMol and FRTL-5 cells, with a strong up-regulation in the former case and a suppression in nontransformed cells. The data suggest that: 1) Met-F-AEA inhibits ras oncogene-dependent tumor growth in vivo through CB1 cannabinoid receptors; and 2) responsiveness of FRTL-5 cells to endocannabinoids depends on whether or not they are transformed by K-ras.

Animals↗
PubMed2001

Comparison between different laboratory tests for the detection and prevention of heparin-induced thrombocytopenia.

BACKGROUND: Heparin-induced thrombocytopenia (HIT) is a possible complication of heparin therapy that can evolve with life-threatening thromboembolism, for which early diagnosis is essential. However, the specific laboratory approach to the diagnosis of HIT is still controversial. METHODS: Sera from 13 patients with HIT, from 15 patients with non-HIT thrombocytopenia, and from 10 normal subjects were used to compare nonfunctional and functional methods to detect anti-heparin:PF-4 antibodies and platelet activation. We used three enzyme-linked immunosorbent assays (ELISAs) and the particle gel immunoassay as nonfunctional tests, and platelet aggregometry, CD62p (p-selectin) phenotypical expression, and Annexin V binding as functional assays. RESULTS: CD62p expression was positive in 85% of the cases and Annexin V was positive in 40% of the HIT cases examined. Aggregometry gave variable results that depend strongly on the donor. CONCLUSION: Functional tests for platelet activation are more reliable for HIT diagnosis than the nonfunctional tests. We conclude that the phenotypical expression of p-selectin detected by flow cytometry on activated platelets appears to be a good functional marker for the diagnosis of HIT and its possible thromboembolic complications.

Adult↗
PubMed2001

Human herpesvirus 7 induces the functional up-regulation of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) coupled to TRAIL-R1 down-modulation in CD4(+) T cells.

Human herpesvirus 7 (HHV-7) is endemic in the adult human population. Although HHV-7 preferentially infects activated CD4(+) T lymphocytes, the consequence of T-cell infection for viral pathogenesis and immunity are still largely unknown. HHV-7 infection induces apoptosis mostly in uninfected bystander cells but not in productively infected CD4(+) T cells. To dissect the underlying molecular events, the role of death-inducing ligands belonging to the tumor necrosis factor (TNF) cytokine superfamily was investigated. HHV-7 selectively up-regulated the expression of TNF-related apoptosis-inducing ligand (TRAIL), but not that of CD95 ligand or TNF-alpha in lymphoblastoid (SupT1) or primary activated CD4(+) T cells. Moreover, in a cell-to-cell-contact assay, HHV-7-infected CD4(+) T lymphocytes were cytotoxic for bystander uninfected CD4(+) T cells through the TRAIL pathway. By contrast, HHV-7 infection caused a marked decrease of surface TRAIL-R1, but not of TRAIL-R2, CD95, TNF-R1, or TNF-R2. Of note, the down-regulation of TRAIL-R1 selectively occurred in cells coexpressing HHV-7 antigens that became resistant to TRAIL-mediated cytotoxicity. These findings suggest that the TRAIL-mediated induction of T-cell death may represent an important immune evasion mechanism of HHV-7, helping the virus to persist in the host organism throughout its lifetime.

Apoptosis↗
PubMed2001

Supravital exposure to propidium iodide identifies apoptosis on adherent cells.

BACKGROUND: Several studies indicate that plasma membrane changes during apoptosis are a general phenomenon. Among the flow cytometric methods to measure apoptosis, the Annexin V assay that detects the membrane exposure of phosphatidylserine (PS) is one of the most commonly used. However, the various treatments used for the detachment of adherent cells generally interfere with the binding of Annexin V to membrane PS, making apoptosis measurement a technical problem. Materials and Methods Apoptosis of different cell lines was investigated by fluorescence microscopy and multiple flow assays designed to assess loss of membrane integrity, translocation of PS, DNA fragmentation, and light scatter changes. Results and Conclusions We show that supravital propidium iodide (PI) assay stains adherent apoptotic cells, allowing flow cytometric quantification. Moreover, supravital exposure to PI without prior permeabilization identifies apoptotic cells as well as Annexin V and permits the simultaneous surface staining by FITC- and PE-conjugated monoclonal antibodies. As in the case of necrotic or permeabilized cells, fluorescence microscopy has revealed that PI staining of apoptotic cells is localized in the nucleus. This suggests that the binding of PI to the DNA/RNA structures is stable enough to withstand the trypsinization and/or washing procedures necessary to detach adherent cells.

Annexin A5↗
PubMed2001

Identification of NKp80, a novel triggering molecule expressed by human NK cells.

The ability of NK cells to kill a wide range of tumor or virally infected target cells as well as normal allogeneic T cell blasts appears to depend upon the concerted action of multiple triggering NK receptors. In this study, using two specific monoclonal antibodies [(mAb) MA152 and LAP171], we identified a triggering NK receptor expressed at the cell surface as a dimer of approximately 80 kDa (NKp80). NKp80 is expressed by virtually all fresh or activated NK cells and by a minor subset of T cells characterized by the CD56 surface antigen. NKp80 surface expression was also detected in all CD3- and in 6 / 10 CD3+ large granular lymphocyte expansions derived from patients with lymphoproliferative disease of granular lymphocytes. In polyclonal NK cells, mAb-mediated cross-linking of NKp80 resulted in induction of cytolytic activity and Ca2+ mobilization. A marked heterogeneity existed in the magnitude of the cytolytic responses of different NK cell clones to anti-NKp80 mAb. This heterogeneity correlated with the surface density of NKp46 molecules expressed by different NK clones. The mAb-mediated masking of NKp80 led to a partial inhibition of the NK-mediated lysis of appropriate allogeneic phytohemagglutinin-induced T cell blasts, while it had no effect on the lysis of different tumor target cells, including T cell leukemia cells. These data suggest that NKp80 recognizes a ligand on normal T cells that may be down-regulated during tumor transformation. Molecular cloning of the cDNA coding for NKp80 revealed a type II transmembrane molecule of 231 amino acids identical to the putative protein encoded by a recently identified cDNA termed KLRF1.

Adult↗
PubMed2001

Role of NKG2D in tumor cell lysis mediated by human NK cells: cooperation with natural cytotoxicity receptors and capability of recognizing tumors of nonepithelial origin.

NKG2D is a recently described activating receptor expressed by both NK cells and CTL. In this study we investigated the role of NKG2D in the natural cytolysis mediated by NK cell clones. The role of NKG2D varied depending on the type of target cells analyzed. Lysis of various tumors appeared to be exclusively natural cytotoxicity receptors (NCR) dependent. In contrast, killing of another group of target cells, including not only the epithelial cell lines HELA and IGROV-1, but also the FO-1 melanoma, the JA3 leukemia, the Daudi Burkitt lymphoma and even normal PHA-induced lymphoblasts, involved both NCR and NKG2D. Notably, NK cell clones expressing low surface densities of NCR (NCR(dull)) could lyse these tumors in an exclusively NKG2D-dependent fashion. Remarkably, not all of these targets expressed MICA/B, thus implying the existence of additional ligands recognized by NKG2D, possibly represented by GPI-linked molecules. Finally, we show that the engagement of different HLA class I-specific inhibitory receptors by either specific antibodies or the appropriate HLA class I ligand led to inhibition of NKG2D-mediated NK cell triggering.

Animals↗
PubMed2001

The analysis of the natural killer-like activity of human cytolytic T lymphocytes revealed HLA-E as a novel target for TCR alpha/beta-mediated recognition.

Cytolytic T lymphocytes (CTL) are known to recognize antigen peptides in association with major histocompatibility complex (MHC) class I molecules expressed on target cells. However, a fraction of human CD8(+) CTL has been shown to lyse certain natural killer (NK)-susceptible target cells via still undefined mechanism(s). These CD8(+) T cells, hereafter referred to as NK-CTL, are frequently composed of cells expressing one single TCR Vbeta expansion (different in different individuals), display a memory phenotype and express HLA class I-specific inhibitory NK receptors. Here we show that cell populations or clones of NK-CTL isolated from three healthy donors homogeneously expressed Vbeta16, Vbeta9 and Vbeta3 TCR, respectively. Various clones isolated under limiting dilution conditions from Vbeta16(+) cells of donor 1 displayed identical TCR Vbeta and Valpha rearrangements, thus suggesting a substantial monoclonality of the NK-CTL subset analyzed. NK-CTL lysed a number of NK-susceptible tumor target cells with the exception of those characterized by beta2-microglobulin (beta2m) deficiency. However, the latter targets became susceptible to lysis upon beta2m transfection. Using monoclonal antibodies specific for the relevant TCR Vbeta or beta2m we provide evidence suggesting that target cell lysis by NK-CTL is mediated by the TCR itself upon recognition of beta2m-associated proteins. The cellular distribution of the potential beta2m-associated proteins in susceptible target cells suggested, as a likely candidate for TCR-mediated recognition, the non-classical HLA-E molecule. The use, as target cells, of the murine TAP2-deficient RMA-S cells, either untransfected or transfected with HLA-E, and loaded with an appropriate HLA-E-binding peptide, provided the direct demonstration that HLA-E represents a ligand recognized by the TCR expressed by NK-CTL. This is the first evidence that human TCR alpha/beta can recognize HLA-E molecules, thus revealing a novel type of TCR-mediated recognition, which may offer new insight in immune responses in both normal and disease conditions.

Cells, Cultured↗
PubMed2001

High-dose intravenous corticosteroid therapy for Graves' ophthalmopathy.

In order to compare oral and high-dose iv corticosteroid therapy for Graves' disease, 25 patients with Graves' ophthalmopathy were treated with two weekly iv injections of 1 g of methylprednisolone diluted in 250-500 ml of physiological solution for 6 weeks, and were compared to a group of 26 patients treated with oral prednisone at a dose of 60-80 mg/day progressively reduced every 2 weeks for a total duration of 4-6 months. The efficacy of treatment was evaluated using the ophthalmopathy index score. Patients were followed at 3, 6, 12 months, and afterwards yearly. All patients showed a significant improvement in signs and symptoms of orbital inflammation and a slight improvement in proptosis and diplopia. Relevant side-effects were reported from patients receiving oral therapy, but no significant side-effects were observed in patients treated with high iv doses; a few cases presented with gastric pain (highly sensitive to aluminium oxide or ranitidine), while most of the patients referred to cutaneous rashes and a metal taste that disappeared some hours after the infusion. Improvements observed after treatment have been stable in both groups. In conclusion, in addition to a lower incidence of side-effects compared to the classic oral therapy, the high-dose iv steroid therapy provides efficient and stable improvement in Graves' ophthalmopathy.

Abdominal Pain↗