Biomedical subjects

G Filice

Publications and source records attributed to G Filice.

At least 55 records · Page 3Linked to original sources

PubMed1989

Prevalence of HIV in normal and at risk population (seroepidemiological investigation during two years).

In this work we reported the results obtained using two ELISA-tests (the seropositivity was confirmed by Western-Blot) for detection of HIV-Ab in normal and at risk population (according by the classification from C.D.C. 1982) exposed to screening for various, sanitary measures. Our results concerning the percentage of seropositivity to HIV-Ab in drug-addicts (49%) are in agreement with the results obtained in the most qualified Italian Centres. The incidence of congenital infection is high, pointed 50%; the 100% of seropositive children were infected by drug-addicts seropositive parents. Casuistry among haemophilic patients we have demonstrated a greater seropositivity in B haemophilic subjects than A haemophilic ones. The seropositivity (24%) verified among prisoners is totally related to drug-addiction. Prevalence of seropositivity among heterosexual partners of HIV positive subjects was 22% among female partners of infected men, and 9% among male partners of infected women. Checking performed upon nursing staff who casually were contaminated by seropositive patient's blood confirmed 100% of seronegativity after eight months. No seropositive subjects were performed in every not a risk group.

Adult↗

PubMed1989

Ultrastructure of Plasmodium falciparum "in vitro". I. Base-line for drug effects evaluation.

A chloroquine-sensitive and a chloroquine-resistant strain of Plasmodium falciparum were examined in drug-free culture. Apart from the presence of knobs on the erythrocytes infected with sensitive parasites, no major differences between the two strains were observed. Nevertheless, the parasites of each strain show a variety of morphological features, some of which are quite similar to drug-induced alterations concerning cytoplasmic organelles, feeding process, and host-parasite interactions.

Animals↗

PubMed1989

Detection of IgG anti-HIV antibodies in mice experimentally infected with HIV-1.

In the present work we report our preliminary data demonstrating the susceptibility of mouse to HIV infection. IgG antibodies were found in mice intraperitoneally inoculated with H9/HTLV-IIIB infected cells. Infected mice showed a humoral response and the antibodies detection includes specific immunoglobulin directed against the major gene product of HIV. Two weeks after infection with HIV infected cells we detected in mice IgG antibodies to p24, and the reactivity to gp41 was observed as early as reactivity to p24 and persisted throughout observation period. The persistence of specific antibody response to HIV after one year seems to demonstrate the possibility of the use of the mouse as animal model for HIV in vivo experiments. Studies concerning the degree and kinetic of HIV infection in mouse are in progress in our laboratory.

Acquired Immunodeficiency Syndrome↗

PubMed1988

Infection of rabbits with human immunodeficiency virus.

An important requirement for the development of a vaccine against the human immunodeficiency virus (HIV-1), the causative agent of AIDS, is a readily available animal model that would allow possible immunogens to be evaluated. The only species to have been infected with HIV-1 so far is the chimpanzee. However, the scarcity of this animal and its designation as an endangered species place severe restrictions on its use as an animal model. Attempts to infect mice, rats, hamsters, guinea-pigs, musk shrews, and rabbits with HIV-1 or infected cells have all been unsuccessful. We now report that the intraperitoneal inoculation of rabbits with HIV-1 or chronically infected H9 cells consistently induces a persistent infection.

Acquired Immunodeficiency Syndrome↗

PubMed1988

The morphogenesis of BLV (bovine leukemia virus) cultivated on FLK (fetal lamb kidney): an ultrastructural study.

A new cell line, obtained by co-cultivation of fetal lamb kidney cells and lymphocytes collected from an adult calf affected by enzootic bovine leukemia, was studied for bovine leukemia virus (BLV) morphogenesis. In this new cell line, called FLK-BLV, persistently infected with BLV, we identified extracellular and intracellular BLV particles. We never observed "budding" particles along the cell surface, and therefore assumed it was a new BLV maturation process in the cell vacuoles. In fact we found mature and non-mature particles connected with the cell-membrane system or cellular debris within vacuoles. We suggest that the viral envelope could be supplied by vacuole membrane. In our samples we also observed a cytopathic effect with syncytia formations similar to those observed on other BLV-producing cell lines.

Animals↗

PubMed1987

Human immunodeficiency virus (HIV): an ultrastructural study.

H-9 cells producing HIV were examined by electron microscopy to value the virus-host cell relationships. HIV fine structure was also studied. HIV induces little cellular damages and it can penetrate into the cytoplasm by phagocytosis. Phagocytosis of the virus could play an important role in the mechanism of cellular infection.

Cell Line↗

PubMed1986

Detection of fungal antigen in body fluids for diagnosis of invasive aspergillosis.

In clinical trials, the diagnostic utility of a radioimmunoassay (RIA) to detect Aspergillus antigen was demonstrated in sera obtained from patients with invasive pulmonary, endothelial, and disseminated aspergillosis, in cerebrospinal fluids from patients with Aspergillus meningoencephalitis, and in bronchoalveolar lavage fluids from patients with invasive pulmonary aspergillosis. The RIA was further evaluated in three blinded, controlled clinical trials. In one, sera were collected prospectively from patients with acute leukemia. Antigenemia was detected in four patients with invasive pulmonary aspergillosis (IPA) due to A. flavus, appeared early in the course of infection of three patients concurrent with the onset and evolution of lung infiltrates, and remitted with antifungal chemotherapy. Antigenemia was not detected in three patients before the onset of IPA, in eight leukemic controls, or in the 24 normals. In contrast, seven bronchoscopies were performed in five patients with IPA; fungi were not isolated in three. In a second study, antigenemia was found in coded sera from two patients with invasive aspergillosis but not in eight controls. In the third controlled study, 616 sera from 79 hematology patients admitted on 152 occasions were analyzed for circulating fungal antigen. The diagnostic utility of the RIA was confirmed and levels of antigenemia correlated with the patients' clinical course. These studies demonstrate the utility of the Aspergillus antigen RIA for diagnosis of invasive aspergillosis in hospitalized high risk patients.

Animals↗

PubMed1986

IgM-IFA, IgM-ELISA, DS-IgM-ELISA, IgM-ISAGA, performed on whole serum and IgM fractions, for detection of IgM anti-toxoplasma antibodies during pregnancy.

The traditional IgM-ELISA has a better sensibility and specificity than IgM-IFA when these two tests are performed on whole sera, but in many cases (sera titer values of greater than 200 I.U./ml) the presence of IgM antitoxoplasma antibodies can be detected only after purification of IgM fractions. The separations of IgM fractions avoids either false positive results due to the rheumatoid factors or antinuclear antibodies, and false negative results due to the competition between IgG and IgM antibodies. The present investigation has shown that antibody titers obtained by IgM-IFA and traditional IgM-ELISA correlate well with DS-IgM-ELISA and IgM-ISAGA performed on whole serum. The false negative results that frequently occur with IgM-IFA and traditional IgM-ELISA performed on whole sera having sera titer values of greater than 200 I.U./ml in IgG IFA are avoided when the same sera were tested by DS-IgM-ELISA and IgM-ISAGA. All the sera which gave positive results by DS-IgM-ELISA were also positive when tested with IgM-ISAGA. Our researches demonstrate the high specificity and sensitivity of IgM-ISAGA and DS-IgM-ELISA performed on whole serum.

Antibodies↗

PubMed1986

Intracellular killing of Brucella melitensis within mouse peritoneal macrophages: influence of treatment with rifampicin. An ultrastructural study.

The aggregation and condensation of ribosomes and the disjunction of the cell-wall membranous system are the ultrastructural alterations caused by rifampicin on B. melitensis cultured in Brucella-Broth medium. Our ultrastructural researches carried out on mouse peritoneal macrophages infected with B. melitensis and treated with rifampicin (1 microgram/ml) have demonstrated that vacuoles containing B. melitensis which had been damaged by the drug fuse with lysosomes. On the contrary vacuoles containing undamaged and viable Brucellae showed markedly impaired lysosomal fusion.

Animals↗

PubMed1986

[IgM ISAGA test in the diagnosis of acute acquired Toxoplasma infections].

An immunoglobulin M immunosorbent agglutination assay (IgM ISAGA) was tested in 1804 outpatients' samples. The test was negative in all 1091 sera from individual negative in the total indirect immunofluorescence antibody (IFA tot) test and in the passive hemagglutination (HA) test and in 15 sera with inconclusive results in these two tests. The 698 sera positive in the IFA tot and HA tests were also tested with direct IgM enzyme-linked immunosorbent assay (IgM ELISA). The 74 sera positive in the IgM ISAGA and/or IgM ELISA were also tested in the IgM immunofluorescent (IgM IFA) test. These sera belong to 42 individuals, 26 of whom were followed for previous positive results in the IgM ELISA test. 51 samples (68.9%) were found positive in both IgM ISAGA and IgM ELISA tests. Only 13 (25.5%) of these 51 samples were found positive in the IgM IFA. 9 samples (12.2%) were positive only in the IgM ISAGA test. Conversely another 9 samples (12.2%) were positive only in the IgM ELISA test, performed on serum as well as on chromatographic IgM fraction. Finally five samples (6.7%) yielded false positive results in the IgM ELISA test, and three of them were found false positive also in the IgM IFA test. All these five samples in fact were found negative on IgM chromatographic fraction in both tests. In conclusion, IgM ISAGA appears to be more specific than direct IgM ELISA or IgM IFA test for the detection of Toxoplasma gondii IgM. Sensitivity of IgM ISAGA test seems to be as good as in the direct IgM ELISA and better than in the IgM IFA test for the diagnosis of acute acquired toxoplasma infection.

Acute Disease↗

PubMed1986

Alterations due to ampicillin and rifampicin in S. sanguis and S. aureus isolated from dental plaque. An electron microscopic study.

In this work we analysed the ultrastructural changes in S. aureus and S. sanguis after exposure to rifampicin and ampicillin respectively. S. aureus grown in the presence of rifampicin showed ultrastructural changes that can be summarized as follows: the peripheral cell-wall increased to three to five times the normal thickness; the cross-walls were considerably (two to ten times) thicker than normal; after 8 h of exposure a complete lysis occurred. S. sanguis grown in the presence of ampicillin showed ultrastructural changes that can be summarized as follows: aggregation and condensation of ribosomes; alterations of division with the presence of asynchronous septa; in some bacterial cells a prominent bulge was observed at one pole of the cell; after 8 h of exposure a complete lysis occurred.

Ampicillin↗

PubMed1985

Life cycle of P. carinii in the lung of immuno-compromised hosts: an ultrastructural study.

We describe the ultrastructural features of interstitial pneumonia and life cycle of P. carinii in the lung of immuno-compromised hosts. The hyperplasia and edema of alveolar lining cells appear to be largely responsible for the extensive desquamative alveolitis which characterizes the histopathologic features of P. carinii in the lung of immuno-compromised hosts. The ultrastructural data concerning the ameboid trophozoite, particularly the presence of lobopodies and the reduplication by binary fission, associated with cyst forming capacity, suggest that P. carinii can be reasonably placed within the Protozoa.

Animals↗

PubMed1985

Toxoplasma gondii: in vivo and in vitro immunological and ultrastructural patterns of a human low virulent strain.

The AA. analyze the ultrastructural and immunological patterns of a low virulent strain of T. gondii cultured in vitro on A-9 cells line (PV-H1C-83). The tissue culture method described here is highly recommended to study the immunological aspects of experimental toxoplasmosis. Biological tests' results and the time courses of serological tests are also similar to those obtained from mice infected with cerebral tissue containing cysts. The low virulent strain (PV-H1C-83), when cultured in vitro, is able to induce the formation of large parasitophorous vacuoles, in which the EM investigation shows a typical cyst wall enveloping numerous bradyzoites.

Animals↗

PubMed1985

Comparison between IgM-IFA and DS-IgM-ELISA performed on IgM fractions and whole sera in acute acquired toxoplasmosis.

The present investigation has shown that antibodies titers obtained by IgM-IFA performed on pure IgM-fractions, obtained by gel-filtration method, correlate well with DS-IgM-ELISA. False negative IgM-IFA results that frequently occurs with sera having greater than or equal to 200 I.U./ml by IgG-IFA, were not observed with DS-IgM-ELISA: and the 98% of sera positive only after separation of IgM fraction with IgM-IFA, are also positive with DS-IgM-ELISA performed on whole serum.

Chromatography, Gel↗

PubMed1984

A comparison of IHA and ELISA tests in the detection of antibodies to entamoeba histolytica.

In this report we have evaluated the sensitivity and specificity of IHA and ELISA for the detection of anti-amebic antibodies in the serum samples of 147 patients with poor mental and hygienic status hospitalized in mental institutions. Our data have demonstrated a positive agreement between ELISA and IHA on positive sera. The major drawback of IHA is the occurrence of false negative results, 13/82 sera negative in IHA (less than 1/128) are positive in the ELISA. Furthermore, the ELISA is useful for serological diagnosis of amebiasis in the laboratories of low endemic areas.

Antibodies↗

PubMed1984

Detection of IgM-anti-toxoplasma antibodies in acute acquired and congenital toxoplasmosis.

The specificity and sensibility of IgM-IFAT for diagnosis of acute acquired and congenital toxoplasmosis may increase after separation of IgM fractions by simple gel filtration method. In the presence of IFA-IgG titers greater than 250 IU/ml with Remington test less than 1/50, specific IgM antibodies to Toxoplasma gondii should be detected by separation. The separation of IgM seems a necessary step for detecting IgM antibodies by IgM-IFA in the newborn sera.

Acute Disease↗

PubMed1984

An improved method for increasing the sensitivity of direct agglutination test (D.A.T.) to the detection of IgM and IgG anti-toxoplasma antibodies.

The present investigation has shown that the antibody titers obtained by IgG-IFA correlate well with 2-ME-DA (correlation coefficient 0.927, p less than 0.001). These results are obtained when the antibody titers are expressed as IU/ml. Buffer without 2-ME and purification of IgM fractions by simple gel-filtration method seem to be necessary conditions for detecting IgM antibodies by DA test in adult patients. Therefore the DA with these micromodifications has a specificity and sensitivity similar to those of IgG and IgM-IFA tests and would be convenient for laboratories that perform large scale surveys during pregnancy.

Adult↗

PubMed1983

Comparison of ELISA and indirect immunofluorescence in the detection of IgG and IgM antitoxoplasma antibodies.

We have compared ELISA and IFA for the quantitation of IgG and IgM antitoxoplasma antibodies on whole sera and purified IgM fractions. In all the sera examined from adult patients the good correspondence of the two tests is expressed by a correlation coefficient of 0.77 (p = 0.001). However, we have observed that both IgM-ELISA and IgM-IFA performed on whole serum may lead either to false positive results due to presence of rheumatoid factors or to false negative results due to the competition with high level of IgG antibodies. The use of the simplified gel filtration method for separation of IgM fraction allowed the detection of IgM in 40 out of 75 adults patients by IgM IFA and in 39 by the same tests resulted negative if performed on whole serum. The separation of IgM fractions seems a necessary step for detecting IgM antibodies by IgM IFA in 12 of 14 newborns sera with clinical and serological evidence of congenital toxoplasmosis. The conventional IgM ELISA was constantly negative when performed on both whole sera or pure IgM IFA positive fractions of the same newborns.

Animals↗