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Biomedical subjects

G Vicari

Publications and source records attributed to G Vicari.

At least 19 recordsLinked to original sources
PubMed1996

Health services: an Italian market.

One of the glories of Italy is its capacity to surprise. In out-of-the-way places extraordinary things are suddenly encountered; and this is hardly less true of science than of architecture or music or painting. Italian medicine can boast excellence in many quiet spots. Yet Italy's record in medical science and practice is perceived to be below par, and one reason may be a lack of central coordination--forgivable in a country that had fifty governments in half a century. The latest administration offers a rare chance of political stability and the prospect of reforms. In this profile of Italian medicine The Lancet's guide was Dr Giuseppe Remuzzi, whose central coordination was exemplary.

Acquired Immunodeficiency Syndrome↗
PubMed1993

Simple and rapid two-step polymerase chain reaction for diagnosis of Pneumocystis carinii infection.

Two amplification steps were made to detect Pneumocystis carinii DNA by polymerase chain reaction (PCR). pAZ102-E and pAZ102-H (standard PCR), pAZ102-L2 (sense), and pAZ102-E (antisense) (two-step PCR) were used as primers. The amplification products were analyzed by ethidium bromide. After the two-step PCR, ethidium bromide detected all samples positive by oligohybridization after one amplification step. Our two-step PCR is a rapid, cost-effective, and clinically suitable method for the detection of P. carinii infection.

Bronchoalveolar Lavage Fluid↗
PubMed1991

Detection of anti-HIV antibodies in immunoglobulin preparations: the significance of antibodies to the HIV-envelope.

Four hundred and sixty-eight immunoglobulin preparations, produced between 1969 and 1989, were examined for anti-HIV antibodies by means of two competitive immunoenzymatic assays and the Western blot test. This study refers the results obtained by the three different methods. Such results show that the detection of anti-HIV antibodies in immunoglobulins may be performed on a routine basis using commercial kits intended for human sera. The meaning of the test and the role of antibodies against the HIV envelope proteins are emphasized.

Blotting, Western↗
PubMed1991

Validation of purification procedures for removing and/or inactivating viruses in biologicals: points to consider.

Viruses represent a main concern as a potential risk associated with the use of both classical biologicals and new biotechnological products. The objective of validation is to estimate quantitatively the overall level of virus clearance obtained during the various stages of purification and viral inactivation procedures. The design of a validation procedure should take into account the amount of contaminating virus in the source material, the minimum clearance factor to be attained for at least one of the stages and the minimum overall clearance factor. A major issue in performing a validation assay is in determining what viruses should be used. In addition to the inclusion of relevant viruses in the assessment, the validation should include a collection of model viruses possessing a range of biophysical and structural features and displaying a significant resistance to physical and/or chemical agents. Despite the apparent freedom from any infectious agents of source materials, such as plasma or cell lines, validation of the purification and/or inactivation procedures plays an essential and important role in establishing the safety of biologicals.

Animals↗
PubMed1991

External quality assessment programs in Italy.

Regulatory control of diagnostic clinical laboratories activities has been defined in Italy since 1984, by an act (DPCM 10/2/84) that regulates such activities and establishes all over the country Quality Control (QC) programs. Before the 1984 act, External Quality Assessment (EQA) programs were exclusively conducted on a voluntary basis by Consiglio Nazionale delle Ricerche (CNR), by scientific societies, or by diagnostic manufacturers. The Subproject "Quality Control" of the Finalized CNR Project "Biomedical and Health Technologies", activated in 1982, is articulated in three fields: (1) EQA of the immunoassays, (2) EQA in the hematology laboratory and (3) EQA in radiodiagnosis. The problems of EQA have been also faced at the European level: initiatives, on both national and regional scale, have been promoted in the majority of the European States in the last ten years (Austria, Belgium, Denmark, Finland, France, Germany, Netherlands, United Kingdom, etc.) and include the main fields of the clinical laboratory analysis: hematology, clinical chemistry, immunochemistry, microbiology, cytogenetics, parasitology. The European Community plans the harmonization of the EQA programs starting from 1993, when reference preparations and commercial diagnostic kits will be subjected to free exchange and trade in the twelve Member States.

Chemistry, Clinical↗
PubMed1988

Cellular immune responses of hydatid patients to Echinococcus granulosus antigens.

The reactivity of peripheral blood mononuclear cells (PBMC) from 40 hydatid patients to hydatid fluid (HF) and to two hydatid fractions (pH5PPT and pH5SUP) was evaluated by the incorporation of 3H-methylthymidine into DNA. Maximal responses were detected using 200 micrograms/ml protein after 7-9 days incubation. The three antigen preparations were inducers of PBMC proliferation, with a good correlation (r2 = 0.87) of the responses induced by HF and by the fraction pH5PPT, which contains the two major hydatid antigens (5 and B). Lymphocytes from healthy donors and non-hydatid patients showed no response to these antigens. Neither direct nor inverse correlation was found between the results of the serological tests and of the PBMC proliferation assays. The majority of the patients (75%) responded in serological and in cellular tests. Of the remaining patients, six showed high antibody response associated with a negative PBMC proliferation assay and conversely four seronegative patients were found to respond positively in the PBMC proliferation assay. No relationship of the pattern of immune responsiveness to the patient's clinical forms could be established. Use of the PBMC proliferation assay with hydatid antigens appears rational in those patients which are low antibody producers, but the test is still not to be considered applicable for routine diagnosis.

Animals↗
PubMed1988

Identification and description of low-molecular weight chemicals inducing hypersensitivity in man.

The purpose of this study is to compose a list of allergenic chemicals. Each chemical is described in a monograph. The objective of such a monograph program is to collect from the international scientific literature available relevant experimental, chemical, and epidemiological data on chemicals to which humans are known to be exposed and sensitized. A list of 721 chemicals, with related synonyms and trade names, that induce allergic responses and hypersensitivities was prepared. The chemicals were selected on the basis of evidence of human exposure and sensitization. Each monograph contains several data considered relevant to the evaluation of the sensitizing hazards of chemical substances. The data are divided in three sections: chemical identity, sensitizing power, and occurrence. All the data contained in the monographs along with the references and the synonyms are stored in a database application computer program. Preliminary results of 308 of 721 monographs analyzed are reported.

Allergens↗
PubMed1987

Isolation and purification of a major allergen from Parietaria officinalis pollen.

A major allergen of Parietaria officinalis, a species responsible for a large number of respiratory allergies in Mediterranean areas, has been identified and characterized. This allergen (Pol) was found in the fraction which precipitates between 70 and 100% ammonium sulphate saturation. Pol showed a molecular weight of 15,000 daltons as determined by SDS-PAGE and HPLC. The pI of Pol was in the pH region 4-6, IEF showing four major bands. Two major bands were shown by CIE, CRIE and immunoblotting; major contaminants or aggregates were also revealed by the latter technique and by HPLC. Pol showed an allergic specific activity 2 times higher than the crude extract; moreover it was shown to be a major allergen since it inhibited 29 out of 30 sera from allergic patients sensitive to P. officinalis.

Allergens↗
PubMed1986

Purification and partial characterization of the major antigen of Echinococcus granulosus (antigen 5) with monoclonal antibodies.

A monoclonal antibody specific for antigen 5 of Echinococcus granulosus was isolated and partially characterized. Purification of antigen 5 was accomplished by affinity chromatography using an immunoabsorbent prepared with this monoclonal antibody. Pure antigen 5 was identified by immunoelectrophoresis, double diffusion in agar gel, sodium dodecyl sulphate-polyacrylamide gel electrophoresis and immunoblotting. The pure antigen displayed the electrophoretic mobility typical of antigen 5 and gave a single precipitin band in double diffusion with both monoclonal antibody and rabbit anti-pH5PPT hydatid fraction serum. Two bands of 66 and 56 kDa could be detected in the pure antigen 5 after sodium dodecyl sulphate-polyacrylamide gel electrophoresis when performed in non-reducing conditions: both bands were reactive with the monoclonal antibody in immunoblotting. After reduction with 2-mercaptoethanol, antigen 5 displayed one band only, of 39 kDa. Antigen 5 purified by this procedure was found to retain reactivity with human sera from hydatid patients in a DD5 test.

Animals↗
PubMed1984

Detection of specific IgE antibodies in sera from patients with hydatidosis.

A simple and sensitive immunoenzymatic assay for detection of specific IgE in hydatid disease is presented. Sera from 43 patients with hydatidosis, eight with schistosomiasis, two with taeniasis, two with cancer and 16 healthy blood donors were tested by both the immunoenzymatic technique and the classical radioallergosorbent test. Data were analysed in terms of different sensitivity and specificity of the two methods. The results indicate that the enzymatic method performed in microplates is as sensitive as the radioimmunological one (77% of positivity for both the tests), but the latter suffers from an higher rate of false positive reactions with sera from patients with other helminthic diseases (80% vs 20%). When the specific IgE evaluation is compared with other classical serological techniques, such as indirect haemagglutination and double diffusion in terms of different sensitivity in revealing an anti-Echinococcus immunological reactivity, the results suggest that specific IgE evaluation represents a useful addition to the classical serodiagnostic tests.

Echinococcosis↗
PubMed1980

Enzyme-linked immunosorbent assay (ELISA) in the serodiagnosis of hydatid disease.

An enzyme-linked immunosorbent assay (ELISA) was adapted for the indirect serological measurement of anti-Echinococcus antibodies in human hydatid disease. Both the tube method and the microtitration procedure were used successfully. However, the tube test with a purified hydatid fluid fraction appears to be the method of choice. ELISA results are comparable to those found in the indirect hemagglutination test and with the agar gel methods (double diffusion and immunoelectrophoresis), but false positive results were observed with the sera of patients with schistosomiasis or liver cirrhosis. ELISA has proved to be a sensitive quantitative procedure for the serodiagnosis of human echinococcosis, even though it has not been shown in our study to be more sensitive than the classical serological procedures such as indirect hemagglutination. It can be concluded that ELISA should be considered not as an alternative but as a useful addition to the range of immunodiagnostic tests available for serodiagnosis of hydatid disease.

Antibodies↗
PubMed1980

Oscillations of IgM antibody affinity at the level of single immunocytes.

IgM antibody affinity was measured by hemolytic plaque inhibition assays on spleen cells from mice immunized with a single injection of DNP-dextran. Maturation of affinity was found to occur with time after 1 to 1000 microgram of immunogen and to be characterized by rapid oscillations independent from changes inFC number/spleen and in antibody secretion rate. Analysis of affinity heterogeneity showed that such oscillations occur in higher affinity PFC subpopulations. The origin of affinity oscillations was discussed in terms of interactions among antigen and the elements of the immune network.

Animals↗
PubMed1978

Time and antigen dose-dependent variations of IgM antibody affinity.

Affinity of IgM antibodies elicited in mice by a single injection of dinitrophenylated dextran was measured by equilibrium dialysis. Maturation of affinity was found to occur with time, the rate of increase being higher after larger antigen doses. Maturation was followed by a decrease of affinity with time, the fall being more pronounced after lower antigen doses. These findings are more in line with the theory of antigen-induced diversity rather than with the maturation theory.

Animals↗