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M Liance

Publications and source records attributed to M Liance.

At least 37 records · Page 2Linked to original sources
PubMed1994

Progress toward the development of vaccines against parasitic diseases: a review based on studies performed by participants of the Laveran seminar.

Although significant advances have been mode during the past 20 years, a better understanding of the orchestration of the immune response against a parasite candidate vaccine is still required for preparing vaccines which can induce the acquisition and the persistence of sterile immunity, without producing side effects in humans. This was, among others, one conclusion of the discussions between Thesis students and scientists. Only some aspects of the different steps of immune responses (recognition, protective effector mechanisms, cell regulation, cytokine activities, immunopathology, parasite escape mechanisms) are here reviewed. They are mainly related to malano and schistosomiasis, but also to other parasitic diseases, for which several experimental models have been developed.

Animals↗
PubMed1993

Experience with doxorubicin-bound polyisohexylcyanoacrylate nanoparticles on murine alveolar echinococcosis of the liver.

The parasiticidal properties of doxorubicin against the metacestode of Echinococcus multilocularis were investigated after binding of that drug to polyisohexylcyanoacrylate nanoparticles, a colloidal biodegradable drug carrier. A reduction of the hepatic parasite development and a reduced viability of the metacestode were observed in mice injected with 5 mg kg-1 body weight-1, but 7.5 mg kg-1 body weight-1 did not appear more efficient. Free doxorubicin or unbound nanoparticles had no antiparasitic activity.

Animals↗
PubMed1992

Effects of cyclosporin A on the course of murine alveolar echinococcosis and on specific cellular and humoral immune responses against Echinococcus multilocularis.

The effects of cyclosporin A (CsA) on Echinococcus multilocularis (E. multilocularis) metacestode growth, and on the specific immune responses of the hosts, were examined in AKR mice. Mice were intra-peritoneally infected with a metacestode homogenate. CsA (40 mg kg(-1) day(-1)) was injected subcutaneously from the 45th day after infection (Group 1), and from the day before infection (Group 2) until the day of autopsy (days 125 and 80, respectively). Results showed that unlike ths situation with some other helminthiases, CsA had no antiparasitic effect, although it lengthened the maturation time of protoscoleces in Group 1. The parasitic burden, unmodified in Group 1, was significantly enhanced in Group 2. This enhancement was associated with a decrease in antibody levels, whereas the delayed-type hypersensitivity was decreased in the two groups. These results confirm the role of cellular immunity in controlling the first stages of the larval development of E. multilocularis and indicate the necessity for a careful follow-up of any recurrence of alveolar echinococcosis in patients treated with CsA after liver transplantation.

Animals↗
PubMed1992

[Alveolar echinococcosis in China: current data].

Very few information about alveolar echinococcosis in China is available outside the country. The aim of the authors is to give some precisions about the human cases and the infection in the natural animal hosts. It occurs in 3 distinct foci which comprise poor and remote rural areas. Approximately, 420 cases of human disease have been detected, and the most intense focus is Ningxia province in central China. In all areas, the adult tapeworm is frequently found in V. vulpes, V. corsac, and in the domestic dog. The intermediate hosts differ from an area to the others. Their infection rate is high in the central and the northern foci. More researches are needed for improving our knowledge about the epidemiology of the disease. But the actual major requirement is to apply control measures as health education and medical information.

Animals↗
PubMed1990

Rapid technique for cryopreservation of Echinococcus multilocularis metacestodes.

Cysts of E. multilocularis were minced to prepare a crude homogenate and after addition of glycerol at a final concentration of 10%, cryopreservation was performed at a rate of 1 degree C min-1 in a controlled-rate freezer. The aliquots were subsequently stored in liquid nitrogen. All 22 isolates tested were successfully cryopreserved and their viability maintained.

Animals↗
PubMed1990

Comparison of the viability and developmental characteristics of Echinococcus multilocularis isolates from human patients in France.

Alveolar echinococcosis, due to E. multilocularis, is usually a fatal disease in patients whether treated by benzimidazolecarbamates or not. However, aborted infections have been described, suggesting the existence of strains of parasites of varying pathogenicity. These observations led us to analyse the viability of larvae in 20 patients. After observation of human lesions, the viability of metacestodes was tested by intraperitoneal infection in two intermediate host species, Meriones unguiculatus and AKR inbred mice. Parasitic development was more frequent in mice than in M. unguiculatus, but in the latter, growth was more rapid and the larval mass produced was greater. Isolates which originated from patients undergoing treatment had an abortive growth; two others were characterized by a steady, though slow, development, producing a poorly budding larva; lastly there were some which were morphologically similar with a multivesicular appearance but differing development times. These results may serve as a guide for more basic studies leading to an understanding of the problem of intraspecific variations in E. multilocularis.

Adolescent↗
PubMed1990

Cellular immunity in experimental Echinococcus multilocularis infection. I. Sequential and comparative study of specific in vivo delayed-type hypersensitivity against E. multilocularis antigens in resistant and sensitive mice.

Species- or strain-related differences in receptivity of intermediate hosts to E. multilocularis larvae could be related to differences in specific cellular immune response of the host. In order to test this hypothesis, we assessed the delayed-type hypersensitivity (DTH) to E. multilocularis antigens (EmAg) in mice of three strains differing by their sensitivity (AKR and C57BL.6) or resistance (C57BL.10) to E. multilocularis infection. DTH was determined by measuring in vivo the foot-pad response 24 h after an EmAg antigenic challenge. The level of positive response was evaluated in immunized mice; however, a typical DTH response was only observed by immunizing mice with a strong adjuvant schedule. Course of DTH in the immunized mice was shown to be somewhat different in sensitive and resistant mice. The differences were much more marked in mice infected with proliferative E. multilocularis larvae. The levels of the footpad response was significantly higher in resistant mice, although the peak of the reaction was obtained later than in sensitive mice. DTH, expressed by the foot-pad response against EmAg, remained significant for the entire period of observation in sensitive as well as in resistant mice. There was no correlation between receptivity of the murine hosts and levels of specific antibodies against EmAg. These results suggest a relationship between resistance to E. multilocularis infection and intensity and/or course of DTH in mice. The resistance could be mediated by some particularities of the in situ cellular immune response in the periparasitic granuloma.

Animals↗
PubMed1990

Cellular immunity in experimental Echinococcus multilocularis infection. II. Sequential and comparative phenotypic study of the periparasitic mononuclear cells in resistant and sensitive mice.

Cellular immune responses have been shown to be associated with differential evolutions of E. multilocularis infection in intermediate hosts. A relationship between course of delayed-type hypersensitivity (DTH) against parasitic antigens and receptivity of murine strains has been demonstrated recently. The aim of this study was to correlate resistance and sensitivity to E. multilocularis infection with the phenotypic patterns of cells within the periparasitic granuloma. Evolution of the ratios, macrophages/T lymphocyte and Ly1/Ly2 T lymphocytes, was associated with the receptivity of the strains. Persistence of numerous L3T4 + T lymphocytes and low numbers of macrophages and Ly2 + T lymphocytes were observed in the 'resistant' C57BL.10 mice. Comparison of the results with course of the DTH against E. multilocularis antigens showed that the particular phenotypic pattern observed in resistant mice was associated with a particular profile of DTH after infection. These results and similar observations in human alveolar echinococcosis suggest that cell composition of the periparasitic granuloma might be of crucial importance in controlling the spontaneous development of E. multilocularis larvae in the intermediate host.

Animals↗
PubMed1990

[Cryptosporidiosis in children: epidemics and sporadic cases].

From April 16 1987 through May 16 1987, during an outbreak of gastroenteritis, stool specimens were obtained from 53 children aged 18 to 36 months among the 90 children attending an on-site day-care center for the staff of a large teaching hospital in the Paris urban area (59%). Oocysts of Cryptosporidium were found in 11 specimens (21%) using an auramine staining technique. Children with diarrhea were more likely to have stools containing Cryptosporidium (p less than 0.01). Subsequently, a prospective study was carried out in the same day care center from July 1987 through January 1988. Among the 103 episodes of diarrhea observed during the study period, there were five cases of cryptosporidiosis (5%). In all these cases, diarrhea was moderate and resolved within ten days. Furthermore, among 148 hospitalized children aged 2 months to 10 years, 2 (1.4%) had positive stool specimens for Cryptosporidium and significant failure to thrive. Thus, Cryptosporidium is a common cause of diarrhea in immunocompetent children, especially in child group settings. Further studies are needed to determine the prevalence and spectrum of the clinical patterns of this parasitic disease.

Child Day Care Centers↗
PubMed1989

Cellular immune response in Echinococcus multilocularis infection in humans. I. Lymphocyte reactivity to Echinococcus antigens in patients with alveolar echinococcosis.

The involvement of cellular immunity in alveolar echinococcosis (AE) due to E. multilocularis is strongly suggested by the intense granulomatous infiltration observed around the hepatic parasitic lesions, and a progressive decrease of specific cellular immunity has been described in murine AE. However, specific cellular immunity against E. multilocularis has never been documented in human AE. The reactivity to phytohaemagglutinin (PHA) and E. multilocularis antigens of peripheral blood mononuclear cells (PBMC) from 48 patients with AE and 35 control subjects was evaluated by incorporation of 3H-methylthymidine into DNA. A sequential measurement of the proliferative response of PBMC was performed in 20 patients 2 years later, and again in five of them 4 years after the first determination. After stimulation by PHA, the mean proliferation index (PI) of the patients with AE was somewhat higher than that observed in the uninfected controls, but the difference was not significant. The PI obtained with E. multilocularis antigens was higher than the threshold value in all the patients but one, and in five control subjects. The difference between the PI values in the patients with AE and those obtained in the control subjects was highly significant. There was no correlation between the lymphocyte proliferation indices and the specific antibodies assessed using the Em 2-ELISA, or the volume of the parasitic lesions. All the five 'positive' control subjects were living in areas endemic for AE. A previous contract of these subjects with E. multilocularis in the past, followed by a spontaneous elimination of the parasite is possible. The long-term persistence of lymphocyte reactivity to parasite antigens was emphasized by the results of the follow-up of 20 patients with AE: reactivity of PBMC decreased progressively but persisted more than 4 years after complete resection of the parasitic lesions in the patients who underwent a radical surgical procedure. Conversely, an increase in the PI was shown to be usually associated with a progression of the liver lesions.

Adult↗
PubMed1988

Randomized trial of albendazole versus tiabendazole plus flubendazole during an outbreak of human trichinellosis.

To determine the therapeutic usefulness of benzimidazoles in trichinellosis, 117 patients from a single outbreak were treated either with albendazole alone (N = 59) or with a regimen including tiabendazole followed by flubendazole (N = 58). The criteria of disease activity were evaluated at days 1, 7, 15, and 45. No difference was found between the two groups with regard to the evolution of myalgia, fever, fatigue, new clinical manifestations, or laboratory and serologic data. Both treatment regimens were well tolerated. In all, 30 patients of the albendazole group and 29 of the tiabendazole-flubendazole group were reevaluated 16 months later. Serology was negative in 70% of the albendazole-treated patients vs 34.5% of the tiabendazole-flubendazole-treated patients (P less than 0.01). The muscle biopsy examination of nine patients suggested less parasitic infection in the albendazole group. In conclusion, no difference was noted during the early therapeutic responses to the drugs used, but albendazole might be more effective than the other regimen in treating residual larval infestation estimated 16 months after the onset of the disease.

Adult↗
PubMed1988

IgE-dependent humoral immune response in Echinococcus multilocularis infection: circulating and basophil-bound specific IgE against Echinococcus antigens in patients with alveolar echinococcosis.

Clinical symptoms of immediate-type hypersensitivity (ITH) and specific IgE against Echinococcus granulosus antigens are frequently present in patients with hydatid cysts. In alveolar echinococcosis (AE) due to E. multilocularis, clinical manifestations related to ITH have never been reported. The IgE-dependent humoral immune response was evaluated in 30 patients with AE. Circulating specific IgE (sIgE) were determined with two different methods of radio-allergo-sorbent test. Serum sIgE were determined sequentially in 18 patients over 15 months. Specific IgE bound to circulating basophils were assessed with two tests in vitro, measuring specific degranulation and histamine release. The respective abilities of E. granulosus and E. multilocularis antigens to reveal bound and circulating IgE antibodies were also assayed. Despite the absence of clinical symptoms of ITH and the frequent lack of circulating sIgE, an immunological response involving IgE was always present in human AE: basophil-bound sIgE were revealed in every patient by histamine release and degranulation tests; these tests were constantly negative in control subjects. Echinococcus granulosus extracts were more effective for detecting circulating sIgE; however E. multilocularis antigenic preparation induced a histamine release significantly higher than E. granulosus extracts. These results suggest that IgE-dependent humoral immune response could play a role in the host-parasite relationship in AE. Moreover, the sensitivity of the tests used to detect basophil-bound sIgE was higher than that of the usual serological tests, and the basophil degranulation test could be used to confirm diagnosis of AE in endemic countries.

Adult↗
PubMed1988

[Cross-reactivity between parasitic antigens and T lymphocyte surface antigens: a possible host-escape mechanism for Echinococcus multilocularis].

We report an immunocytochemical analysis of E. m. protoscolices obtained in 2 strains of mice (AKR, Balb c) which were experimentally infected. Sections of hepatic and peritoneal lesions and spreading of protoscolices from peritoneal vesicles were analyzed. Five monoclonal antibodies, specific of murine T lymphocyte populations, produced an intense and regular staining of the anterior area of the protoscolices. This immunostaining has not yet been explained; it could bear witness to particular mode of parasite protection against host immunological responses.

Animals↗
PubMed1985

[Circulating and basophil-fixed specific IgE in human alveolar echinococcosis].

Biological parameters of immediate type hypersensitivity were assessed in 19 patients with alveolar echinococcosis. Serum total IgE concentrations were higher than normal values in 12 patients, and parasite-specific IgE were present in 9 patients. A significant relationship was observed between these two parameters. Evolution of specific IgE during a 1-year period appeared to correlate with surgical removal of parasitic material; it did not correlate with the clinical evolution in patients treated with mebendazole. Specific basophil fixed-IgE were demonstrated using both a basophil degranulation test and a histamine release test in the 19 patients under study, including serologically negative and circulating specific IgE-negative patients.

Basophils↗