59 research outputs found
The introduction of a NAT method of screening blood donors in Italy : a report of the first two years’ experience and a re-evaluation of residual risk
No full textThe use of NAT technology to screen blood donors in Italy became obligatory in July 2002, but the methodology had been introduced in a trial form the previous year. In the same period an EIA test to detect HCVcoreAg had also been introduced. This EIA narrows the window of immunologically silent HCV infection to a similar extent to that of the NAT methodology. The experimental phase of introducing NAT technology in screening blood in Italy lasted 18 months, but the test became obligatory in July 2002. There was an initial reorganisation of biological validation of units of blood and, despite the tests being concentrated in a smaller number of structures, the feared difficulties in releasing blood components did not occur. Furthermore, the NAT was added to the previously used tests without replacing any of them and a variety of organisational models were set up in the different Regions. The "Italian Group for the Study of Transfusion-Transmissible Diseases" of SIMTI has collected the epidemiological data relating to the two years from 219 Transfusion Services in Italy: overall, data were collected on tests for HCV markers in 2,756,739 units of blood components, of which 1,906,659 were examined with NAT techniques, and on 888,506 units examined for HIV RNA. The incidence of cases that were positive only by NAT, and negative for the respective antibodies, was 3.1/106 for HCV RNA and 1.1/106 for HIV RNA. The introduction of NAT technology allows 10 units potentially infectious for HCV or HIV to be identified in one year and reduces the residual risk of transmitting HCV and HIV via transfusion to 0.5 and 1.1 units per million, respectively
Residual risk of transfusion-transmitted HCV and HIV infection by antibody-screened blood in Italy
No full textBACKGROUND: This study was designed to assess the risk of transmitting HCV and HIV by transfusion of antibody-screened blood and to estimate the additional reduction in risk that may be achieved through the implementation of direct viral detection assays in Italy. STUDY DESIGN AND METHODS: Clinical and laboratory data of 2,411,800 blood donations collected from repeat volunteer donors from 1996 through 2000 were analyzed. The risk of transmitting HCV or HIV from screened blood donated during the window period was estimated using a mathematical model. RESULTS: The residual risk of donating antibody-negative infectious blood was estimated at 1 in 127,000 donations for HCV and 1 in 435,000 for HIV. The use of NAT should further reduce such risk by 83 percent for HCV and 50 percent for HIV. CONCLUSION: The residual risk of HCV or HIV transmission through screened blood is currently very small in Italy. The implementation of direct viral detection assays can further improve the safety of blood supply
HIV-1 gp120 impairs the differentiation and survival of cord blood CD34+ HPCs induced to the erythroid lineage
No full textAnemia is the most common hematological abnormality in human immunodeficiency virus (HIV)-infected patients. Besides chronic disease, opportunistic infections, nutritional deficiencies and antiretroviral drug toxicity, the direct role of HIV in the development of anemia has not yet been fully investigated. To explore the HIV-related mechanisms involved in the genesis of anemia, we used two experimental designs. In the first, HPCs purified from cord blood were challenged with HIV-1IIIb or recombinant gp120 (rgp120) and then committed to erythrocyte differentiation (EPO-post-treated HPCs). In the second, HPCs were first committed to differentiate towards the erythroid lineage and only afterwards challenged with HIV-1IIIb or rgp120 (EPO-pre-treated HPCs). Our results showed that HPCs and EPO-induced HPCs were not susceptible to HIV-1 infection. In addition, the two experimental designs (EPO post or pre-treated HPCs) independently showed that HIV-1IIIb or rgp120 were able to induce the impairment of survival, proliferation, and differentiation albeit differing in kinetics and extent. Interestingly, the gp120 interaction with CD4 and CXCR4 played a pivotal role in the impairment of erythrocyte differentiation by inducing TGF-b1 expression. These observations reveal an important additional mechanism involved in the genesis of anemia suggesting a complex competition between EPO-positive regulation and HIV-negative priming regarding erythrocyte survival, proliferation and maturation
I Cavalieri di Aristofane e la riabilitazione di Temistocle
No full textLa rassegna e l'esame dei riferimenti espliciti e velati all'uomo politico ateniese Temistocle contenuti nella commedia "I cavalieri" di Aristofane consente di rintracciare la complessa trama propagandistica nell'Atene della metà degli anni Venti del V secolo a.C
H_v-Fields, h/v-Fields
No full textLast decades the hyperstructures have a lot of applications in mathematics and in other sciences. These applications range from biomathematics and hadronic physics to linguistic and sociology. For applications the largest class of the hyperstructures, the H v -structures, is used, they satisfy the weak axioms where the non-empty intersection replaces the equality. The main tools in the theory of hyperstructures are the fundamental relations which connect, by quotients, the H v -structures with the corresponding classical ones. These relations are used to define hyperstructures as H v -fields, H_v-vector spaces and so on, as well. The extension of the reproduction axiom, from elements to fundamental classes, introduces the extension of H_v-structures to the class of h/v-structures. We focus our study mainly in the relation of these classes and we present some constructions on them
From Continuous to Discrete via V&V Bar
No full textThe ‘continuous’ and the ‘discrete’ in nature and in science live and fight forever. The questionnaires and the Lickert scales are indispensable and widely used tools in social sciences research. Vougiouklis & Vougiouklis bar is a new tool introduced as an alternative to Lickert scales. We believe that such an alternative might offer some solutions to problems that crop up during the fight between continuous and discrete. Nevertheless, the greatest contribution of the V&V bar is that it offers the researchers freedom in all stages of the research procedure using a questionnaire
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