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Biomedical subjects

G Carnevale

Publications and source records attributed to G Carnevale.

67 records · Page 4Linked to original sources

Reliability of IgM-IFA and IgM-IHA tests on pure IgM fractions obtained by a simple gel filtration method in acquired and congenital toxoplasmosis.

We have devised a rapid and inexpensive gel filtration method to separate IgM fractions from small amounts of serum. These fractions have been titrated with IgM-IFAT and IgM-IHAT, and their titers have been compared with those obtained on whole serum. The results show that the separation of IgM from IgG allows detection of IgM antibodies in many cases of acquired toxoplasmosis, especially in cases of congenital toxoplasmosis. False positive results due to the presence of rheumatoid factors are also avoided. The IHA test performed on IgM fractions is constantly negative.

Adult↗

A comparative ultrastructural study of the low virulent strain PV-C1/81 and RH strain cultured in A9, Vero, SIRC cell lines.

A human Toxoplasma strain, isolated in mice from bioptic lymphoglandular tissue, has been cultured in vitro in continuous cell lines. Its presence in some parastized cells, with parasitophorous vacuoles surrounded by a cyst-like wall and filled with a cystozoite-like clone, was observed by electron microscopy. These characteristic and constant features were confined in different cell line cultures and are suggested as possible markers of low virulent strains.

Animals↗

Immuno-electron microscopic localization of antigenic sites for specific immunoglobulins G and M on Toxoplasma gondii surface.

The results of immuno-electron microscopic reaction obtained with anti-IgG and/or anti-IgM ferritin conjugated sera after the inter-reaction of RH strain with specific IgG and/or IgM immunosera, confirm: 1) antigenic sites for specific immunoglobulins both IgG and IgM localization on superficial membrane of pellicular complex; 2) the saturation of common antigenic surface sites due to the competition between IgG and IgM; 3) the competitive prevalence of IgG even if IgM concentration is relatively high in unfractioned immunosera. The practical application of such results is discussed in relation to the specific tests for IgM evidentiation during primary response.

Animals↗

Kinetics of IgM and IgG antibodies in mice experimentally infected with cystogenic strain of Toxoplasma gondii.

Mice were infected with a "cystogenic" strain of T. gondii and sera obtained at different times were tested using DT and IFAT (cell wall antibodies tests) and IHAT (performed with extractive cytoplasmic antigen). We found different kinetics of DT- and IFAT- versus IHAT-titers: IHAT is negative during the early phase of the experimental infection when DT and IgM-IFAT are already positive. Furthermore IgM antibodies were never found against cytoplasmic antigens by the IHAT method. At weekly intervals after the experimental infection a biological test was also performed using samples of different organs. We found that one week after the infection only the brain was constantly positive in the biological test. The antibody pattern was similar in every positive test irrespective of the source and size of the material used for the inoculum. These data suggest that the result of a biological test may be available earlier (already after 7 days) if a test for antibodies against cell wall antigens is performed on the IgM fraction of the mouse serum.

Animals↗

Isoenzyme analysis of Entamoeba histolytica for evaluation of pathogenicity: detection of zymodeme XIX in South America.

Authors report the results of the isoenzyme analysis of strains of Entamoeba histolytica isolated from international travellers. This recently developed method allows the detection of pathogenic strains by evaluating the electrophoretic mobility of cytoplasmic enzymes and was proved to be more reliable and quickly feasible than previous ones. The experience reported refers to three strains isolated from travellers coming from Ecuador, Brazil and Indonesia, respectively; the zymodeme XIX (in accordance with the Sargeaunt's classification) was identified in all the three cases. This zymodeme has been first detected in 1981 and should currently be considered rare; moreover, it has never been previously reported from the Americas.

Amebiasis↗

Primary HIV-1 resistance in recently and chronically infected individuals of the Italian Cohort Naive for Antiretrovirals.

The risk of acquiring HIV-1 drug resistance at time of infection has become a public health problem following the widespread use of antiretroviral drugs in developed countries. Although a number of studies have reported data regarding the prevalence of HIV-1 primary resistance in developed countries over the past years, limited knowledge is available regarding the proportion of mutations related to drug resistance in antiretroviral naive subjects with chronic HIV-1 disease. In this study, we evaluated the prevalence of mutations in the reverse-transcriptase (RT) and protease region both in a representative group of recently HIV-1 infected subjects (n=68) and a cohort of chronically-infected HIV-positive patients (n=347) enrolled in the Italian Cohort of Antiretroviral Naive patients (I.CO.NA.). In recently infected individuals, the overall prevalence of mutations for nucleoside RTI (NRTIs) was 10/68 (14.7%). The distribution of mutations by calendar year were 0, 1 in 1996, 9, 3 in 1997 and 1, 0 in 1998 for NRTIs and protease inhibitors (PIs) respectively. Thymidine associated mutations were identified in six subjects (8.8%), five of whom had one mutation [41L, 70K (n=2), 215Y] and one had two mutations (67N+219Q). Four subjects (5.9%) showed the changes associated with resistance to lamivudine (184V or 118I). No non nucleoside-RTI (NNRTI) mutations were present in the study period. Primary PIs mutations (two 46L and two 82I) were present in four subjects (5.9%). Of note, mutations related to resistance to more than one class of antiretrovirals were present in one (1.5%). Among patients with chronic infection a large proportion (88.5%) carried no mutations in RT region, 11.5% individuals carried one or more mutations associated with resistance to NRTI (7.8%), or NNRTI (4.9%), with 4 patients carrying mutations to both classes. Among mutations associated with high-level resistance to RTI, T215Y was found in only 2 patients, M184V in 2 cases, T69D in another case, and K103N in only 1 patient, for a total of 6 patients (one carrying both T215Y and M184V) (1.7%). Primary mutations associated with substantial resistance to PIs were found in only 5/347 patients (1.4%); all the other patients carried only secondary mutations. Prevalence of mutations associated with high-level resistance to antiretroviral drugs is stable in recently infected individuals and low in patients with established HIV infection. The potential impact of transmitted mutations on the response to first regimen in individuals carrying transmitted mutations needs to be assessed by prospective studies.

Acute Disease↗