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E Candolfi

Publications and source records attributed to E Candolfi.

At least 37 records · Page 2Linked to original sources
PubMed1995

[Current diagnostic aspects of toxoplasmosis].

Biological diagnosis of toxoplasmosis is now based more widely on combined use of serology and techniques for detection of the parasite or its constituents. Serologic methods endeavour to describe more reliably the antibodies involved in the humoral response and define their specific antigenic properties. Use of purified parasite proteins and characterization of isotypes having short-lived kinetics now make it possible to be more precise about the date of contamination in the case of first infections; however, serology remains of limited interest for diagnosis of toxoplasmosis in immunodepressed patients. Techniques for detection of the parasite by cell culture, or of parasite DNA by polymerase chain reaction, now represent the alternatives of choice to direct search or animal inoculation. These techniques are more specifically indicated where the immune response is abnormal or absent, particularly in immunodepressed patients and in the fetus. The results, obtained in a few days, provide a reliable diagnosis and enable specific treatment to be instituted.

Animals↗
PubMed1995

[Prevalence of toxoplasmosis in a population of pregnant women in Antananarivo (Madagascar)].

The prevalence of Toxoplasma antibodies by ELISA was studied in Antananarivo area, in the Republic of Madagascar, among a population of 599 pregnant women. The overall prevalence is 83.5%. From the age of 19 years old, 75% of the pregnant women have already antitoxoplasma antibodies. The ethnic factor, the foods habits or the presence of a domestic cat do not seem to have an influence on prevalence of toxoplasmosis among the studied population.

Adolescent↗
PubMed1995

Studies on the role of interleukin-12 in acute murine toxoplasmosis.

Interleukin-12 (IL-12) is important in the regulation of resistance to Toxoplasma gondii in mice with severe combined immunodeficiency (SCID). The protective ability of IL-12 in SCID mice appears to be through its activity on natural killer (NK) cells to induce production of interferon-gamma (IFN-gamma). In this study we assessed the role of IL-12 in the acute stage of toxoplasmosis in immunocompetent mice. Administration of IL-12 to BALB/c mice infected with the virulent C56 strain of T. gondii remarkably delayed time to death. The protective activity of IL-12 was abrogated by administration of monoclonal antibodies to IFN-gamma or tumour necrosis factor-alpha (TNF-alpha), and by depletion of NK cells using an antisera against asialoGM1. Whereas BALB/c mice infected with the ME49 strain of T. gondii survived infection, administration of anti-IL-12 to infected mice resulted in 100% mortality accompanied by decreased serum levels of IFN-gamma. Furthermore, this treatment significantly reversed the suppression of spleen cell proliferation to concanavalin A (Con A), which is associated with the acute stage of infection, and resulted in decreased ex vivo production of IFN-gamma, IL-2, IL-4 and IL-10 in response to Con A. Our results indicate an important role for IL-12 in mediating resistance to T. gondii during acute infection in immunocompetent mice, that NK cells are required for this protective activity, and that IL-12 is involved in the immunosuppression which accompanies this infection.

Acute Disease↗
PubMed1994

The Vitek immunodiagnostic assay for detection of immunoglobulin M toxoplasma antibodies.

We compared the Vitek immunodiagnostic assay for detection of immunoglobulin M (IgM) toxoplasma antibodies (VIDAS TXM) with an IgM enzyme-linked immunosorbent assay (ELISA) which we developed. A total of 407 serum samples from 391 adults were used for this study. We also examined 17 serial serum samples from four women who had seroconverted during gestation. We observed a sensitivity of 99.5%, a specificity of 93%, a positive predictive value of 93.6%, a negative predictive value of 99.5%, and a global agreement of 96.3%. In each case of seroconversion the VIDAS TXM became positive at the same time as did the IgM ELISA.

Adult↗
PubMed1994

Mitogen- and antigen-specific proliferation of T cells in murine toxoplasmosis is inhibited by reactive nitrogen intermediates.

Acute and chronic infections with Toxoplasma gondii result in a nonspecific suppression of immunologic function in mice and humans. Proliferation of spleen cells in response to concanavalin A (ConA) and toxoplasma lysate antigen (TLA) was studied during the course of infection in mice susceptible (CBA/Ca) and resistant (BALB/c) to development of toxoplasmic encephalitis to determine if reactive nitrogen intermediates (RNI) are involved in the suppression of the proliferative responses. Maximal suppression of proliferation of spleen cells in response to ConA and TLA was observed on days 7 and 14 after infection and correlated with elevated levels of nitrite in spleen cell culture supernatants. By day 68 postinfection in BALB/c mice, proliferative responses returned to normal levels, whereas in CBA/Ca mice, they remained suppressed. The addition of an inhibitor of production of RNI (NG-monomethyl-L-arginine) increased proliferation of spleen cells in response to both ConA and TLA at days 7, 14, and 21 after infection. Depletion of adherent cells from spleen cell preparations obtained from acutely infected mice followed by their repletion with adherent spleen cells from uninfected mice resulted in increased proliferation of spleen cells from infected mice and a significant decrease in nitrite in the cultures. These results indicate that production of RNI by macrophages contributes significantly to the suppression of the spleen cell proliferation observed in the acute stage of toxoplasmosis.

Animals↗
PubMed1993

[Prevalence of toxoplasmosis in Pointe-Noire in Congo. Study of the sampling of 310 subjects].

The prevalence of toxoplasma antibodies was studied in 310 individuals in the city of Pointe-Noire in Congo. The age ranged from 1 to 50 years. The seroprevalence in this study population was 41.9%. Seroprevalence increase with age until 20 years of age, indicating that infection is acquired early in life. Because the seroprevalence did not significantly increase after 20 years of age, we postulate that acquisition of infection is acquired via contact/ingestion of soil contaminated with oocysts rather than via ingestion of undercooked meat containing toxoplasma cysts. No differences were observed in seroprevalence between the sexes and between the different ethnic groups analysed. However, significant differences in the seroprevalence were observed in individuals originated from different regions of the Congo. These high prevalence rates noted in this study also alerts physicians on the risk of reactivation of chronic toxoplasma infection in the immunocompromised patients in particular those coinfected with HIV.

AIDS-Related Opportunistic Infections↗
PubMed1990

Malaria in refugee camps in eastern Sudan: a sero-epidemiological approach.

A study of the endemicity of malaria was carried out in two refugee camps in Sudan, and the advantages and disadvantages of treating either all febrile cases or only confirmed cases of malaria were considered. Based on the information obtained during the survey, guidelines for the treatment of malaria in such refugee camps are proposed.

Adolescent↗
PubMed1988

Early prenatal diagnosis of congenital toxoplasmosis using amniotic fluid samples and tissue culture.

The presence of Toxoplasma gondii in amniotic fluid was demonstrated using tissue culture in four of nine cases of congenital toxoplasmosis, whereas Toxoplasma gondii antigen was undetectable using a sensitive enzyme immunoassay technique. Parasites were identified in monolayers four days after inoculation using an indirect immunofluorescence assay. Since tissue culture may provide evidence of infection within a few days, this method is proposed for early prenatal diagnosis of congenital toxoplasmosis.

Amniotic Fluid↗
PubMed1988

[Toxoplasmosis in Niger. A serological analysis of 400 subjects].

A toxoplasmosis serological study using an indirect immunofluorescence method was made in 400 subjects in the Republic of Niger because the epidemiologic findings of this disease were very poor. Serum antitoxoplasmic antibodies were present in 18.2%. In sahelian areas prevalence of such toxoplasmic antibodies is low in the majority of studies. Analysis of seropositivity and age pointed out a late seroconversion.

Adolescent↗
PubMed1988

[Diagnosis of ocular toxoplasmosis by the ELISA method applied to the determination of immunoglobulins of the aqueous humor].

The toxoplasmosic origin of focal chorioretinitis can be detected on the basis of certain clinical signs in the fundus. However, this must be biologically confirmed by studying the local production of specific antibodies. For that purpose, the rate of intraocular specific Immunoglobulins is compared to the serum rate. The ELISA method is well adapted to quantitative determination of microamounts in aqueous humors. The authors report a study of 103 patients of whom, 28 were suffering from uveitis, and have studied the correlation between clinical lesions and results of the ELISA test. There was no false positive in the first group reference series, and in the positive cases there was a very high correlation with the clinical indicators.

Adolescent↗
PubMed1987

Detection of circulating antigens in immunocompromised patients during reactivation of chronic toxoplasmosis.

One hundred and fifteen sera from nineteen patients undergoing bone marrow transplant and four recipients of kidney transplant who showed serological or clinical reactivation of chronic toxoplasmosis were tested for Toxoplasma gondii circulating antigen (TCA) by enzyme-linked immunosorbent assay using antitoxoplasma IgG antibody coupled to alkaline phosphatase. Seven bone marrow transplant patients and one kidney transplant recipient were TCA positive either before or at the time of antitoxoplasma IgG antibody increase. TCA continued to be detected in one patient with neurological toxoplasmosis until his death. In the other patients, TCA disappeared when IgG antibodies rose, probably due to the formation of immunocomplexes consisting of TCA and immunoglobulins. In the TCA seronegative patients, the presence of circulating immunocomplexes or TCA kinetics of short duration may explain these results. Patients receiving immunosuppressive therapy should be tested for TCA.

Antigens, Protozoan↗
PubMed1985

[Significance of antigenemia and IgG, IgM, IgA and IgE antibodies in the immunology of hydatid cyst. Results of immuno-enzymology. Apropos of 87 cases].

Circulation antigen and sera antibodies were measured in 122 sera obtained from 87 patients with proved hydatic echinococcosis: the sera were obtained before and after surgical treatment. Circulating antigen was detected by E. L. I. S. A., and was present in 21% of the sera. Antibodies were present by conterimmunoelectrophoresis in 56%, by haemagglutination in 72%, E. L. I. S. A. IgG in 87%, E. L. I. S. A. IgM in 54%, E. L. I. S. A. IgA in 53%, E. L. I. S. A. IgE in 25% of the sera. No evident correlations between these results and the localisation could be found, nor with anatomical integrity of the cyst, or the surgical treatment date. Only the presence of IgE or circulating antigen could suggest the high level passage of hydatic proteins, bringing to mind a fissuration of the cyst wall.

Adolescent↗
PubMed1983

[Gel fractionation of immunoglobulins in the detection of specific antitoxoplasma IgM. Evaluation of a 1-year study].

Toxoplasmosis seroconversion is diagnosed on the presence of fluorescent antibodies. IgG level kinetics and presence of IgM at the Remington test are usually the points taken in consideration. But the Remington test can be false positive, or inadequate. The authors report their experience of gel filtration of sera in toxoplasmosis, and discuss the help that this method can be establishing diagnosis in the case of a positive Remington test.

Chemical Fractionation↗
PubMedDate not supplied

Role of gamma interferon and T cells in congenital Toxoplasma transmission.

In the BALB/c mouse model, primary infection with Toxoplasma gondii during the second third of gestation leads to a high percentage of infected foetuses. However, immunity induced by infection contracted before pregnancy prevents parasites from crossing the placenta and completely protects the foetuses, as well as the pregnant women. In order to clarify the roles of CD4+, CD8+ T lymphocytes and IFN-gamma in this protection, pregnant BALB/c mice were treated with depleting monoclonal antibodies against CD4, CD8, IFN-gamma, or control antibody. Only the foetuses of the groups treated with anti-CD8 and anti-IFN-gamma antibodies developed congenital toxoplasmosis. The maternal production of IFN-gamma was depressed in the mice depleted of CD4 and CD8 cells (P < 0.001). Determination of the blood parasite load demonstrated that materno-foetal transmission of T. gondii correlates with maternal parasitaemia. Together, these results show that CD8+ T lymphocytes and IFN-gamma play an important role in protection against congenital toxoplasmosis during reinfection.

Animals↗