PubMed Health⌕ Search

Biomedical subjects

L Monjour

Publications and source records attributed to L Monjour.

At least 37 records · Page 2Linked to original sources
PubMed1992

A simple method for detection of monoclonal isotypes.

A simple rapid method of enzyme labeled anti-isotype assay (ELIA) for detection of monoclonal isotype on hybridoma cells is proposed. This alternative method was first carried out on hybridoma cell lines 147C11 and 257C11 produced against Trypanosoma cruzi and male accessory secretion of Panstrongylus megistus, respectively. The monoclonal antibodies produced by these hybridoma were characterized by this method as IgM (147C11) and IgG1 (257C23) isotypes, allowing evaluation of isotype without having to wait until the concentration of antibody present in the supernatant itself rises. Results were confirmed by Ouchterlony immunodiffusion. The proposed method offers the advantages of a permanent rapid procedure for light microscopy.

Animals↗
PubMed1992

Study of humoral immune response in mammals immunized with Plasmodium falciparum antigenic preparations.

Six Plasmodium falciparum protein fractions, isolated under reducing conditions, were used to immunize mice, rabbits and the squirrel monkey Saimiri sciureus. Five or seven subcutaneous injections of each antigenic preparation, in conjunction with Freund's complete or incomplete adjuvants, were administered. This led to the development of specific antibodies detected by IFAT, ELISA or immunoblotting which inhibited merozoite reinvasion in in vitro P. falciparum cultures. This activity seems to be associated with rhoptry proteins contained in fractions Pf F2 and Pf F4.

Animals↗
PubMed1992

Serodiagnosis and screening of canine visceral leishmaniasis in an endemic area of Corsica: applicability of a direct agglutination test and immunoblot analysis.

For effective control of visceral leishmaniasis caused by Leishmania infantum in the Mediterranean area, the detection of infected dogs is of utmost importance. To assess the suitability of a direct agglutination test (DAT) and immunoblot analysis in serodiagnosis and screening of infected dogs under field conditions, a study was performed on 113 dogs in an endemic area of Corsica. Twenty one of 22 parasitologically confirmed cases were correctly diagnosed by both tests, and 100% specificity was found when 11 dogs with other diseases were examined. Interestingly, eight of 80 apparently healthy dogs from the same area were found to be parasite-positive by the DAT test as well as by the immunoblot. Although both tests were equally sensitive and specific, based on both the feasibility of its application in field conditions and ease of performance, we consider the DAT to be more suitable for serodiagnosis and large-scale screening of infected dogs.

Agglutination Tests↗
PubMed1992

[Application of a new transport and storage material for improving the quality of drinking water in rural African areas].

Although boreholes in rural african areas deliver safe drinking water, there is a daily consumption of water polluted by fecal bacteria. Contamination occurs during transport, storage and domestic allocation of water. This is directly attributable to ignorance of the rules of hygiene, and the use of traditional jars ineffective in maintaining water quality. Their replacement with more modern recipients and the initiation of sanitary education markedly decrease bacterial water contamination, however, WHO standards which define portable water are rarely attained. In fact, it seems that established WHO conditions can only be achieved with piped water or after chemical disinfection.

Africa↗
PubMed1991

Immunoblot analysis of the humoral immune response to Leishmania donovani infantum polypeptides in human visceral leishmaniasis.

Using the immunoblot technique, we have compared the reactions of Leishmania donovani infantum polypeptides with the immunoglobulin G of human sera from patients with parasitologically proven L. d. infantum infection, with suspected visceral leishmaniasis, and with other leishmaniases, protozoiases, helminthiases, and fungal or bacterial diseases. A 94-kDa component reacted with all L. d. infantum-infected sera and with 75% of sera from patients with clinical and serological but no parasitological diagnoses. No reaction was observed with sera from patients in the other disease groups or with control sera. Studies of eight different isolates, subspecies, and species of the genus Leishmania demonstrated that the 94-kDa component was expressed in all strains examined.

Animals↗
PubMed1990

Interactions between the human monocytic leukaemia THP-1 cell line and Old and New World species of Leishmania.

The human promyelocytic THP-1 cell line has been found to support the growth of Leishmania parasites. THP-1 cells, differentiated with retinoic acid, cease replication while remaining in suspension. 72 +/- 8% of THP-1 cells became infected after inoculation with promastigotes of several Old and New World Leishmania species. The resulting amastigotes (19 +/- 5 per infected cell) were easy to harvest, capable of reinfecting cultures of normal human cells and, in the case of L. major and L. infantum, caused specific lesions in BALB/c mice. This culture system should facilitate biochemical and immunological studies on amastigotes and be of use in screening anti-parasite drugs.

Animals↗
PubMed1990

Enzyme immunoassays for detection of malarial antigens in human plasmas by Plasmodium falciparum monoclonal antibodies.

The screening of blood donors for the detection of dangerous disease carriers is a mandatory requirement for blood transfusion centers. Enzyme immunoassay (EIA) is a suitable method for the examination of large populations. We describe a sandwich EIA allowing the detection of soluble malarial antigens in plasma using 11 mouse monoclonal antibodies. Among the 121 combinations tested, 2 were selected for their sensitivity and specificity. Both were applied to plasmas of (a) acute patients, (b) people living in malarious areas, (c) blood donors at risk (travelers), and (d) sedentary blood donors without risk. With 1 of the 2 combinations, the percentage of positive answers was 68.4% (n = 38) for a, 62.6% (n = 206) for b, 4.5% (n = 398) for c, and 0.8% (n = 485) for d; with the other combination, the percentage of positive answers was 68.4% for a, 46.1% for b, 1.5% for c, and 0% for d. Using 2 combinations simultaneously, the positive results were 94.7% for a, 70.4% for b, 5% for c, and 0.8% for d. The 2 assays are complementary and the pair can be used for maximum Plasmodium falciparum antigen recognition in prospective donors.

Animals↗
PubMed1990

Evaluation of traditional filters for water purification in Burkina Faso.

Most tropical water springs are polluted with microbial agents such as faecal coliforms and streptococci, so for the present and the forseeable future, boreholes are considered to be the most appropriate system for reducing the bacterial contamination of water. However, from source to consumer, safe drinking water usually becomes polluted with faecal bacteria. This observation which calls into question the success of the International Drinking Water Supply and Sanitation Decade should stimulate efforts to provide a reliable means of water purification. The use of traditional filters prepared with sand, gravel and charcoal has been proposed but our results reveal that they give no guarantee for the purification of bacteria-polluted water.

Burkina Faso↗
PubMed1989

Vaccination trial against canine visceral leishmaniasis. Phocean Veterinary Study Group on Visceral Leishmaniasis.

In a double-blind study 393 seronegative dogs, residing in a holoendemic area for Leishmania donovani infantum infection, were randomly assigned to an immunization with a partly purified L.d. infantum-derived preparation, or received adjuvant only. During the first year of the study period the rate of infection was significantly higher in the vaccinated group than in the control one (P less than 0.05), but this difference disappeared during the second year (P = 0.44). Since a similar immunization protocol conferred resistance against experimental murine leishmaniasis, these results stress the differences that may exist between the natural hosts of Leishmania parasites and experimental animal substitutes.

Animals↗
PubMed1989

[An immunologic method of producing antigens for the treatment and prevention of leishmaniasis].

Antigens isolated from lysates of L. infantum promastigotes by electroelution from polyacrylamide gels and by gel filtration, have already been proven to induce anti-Leishmania protective immunity in BALB/c mice when injected subcutaneously. At the present time, five preparations including either Leishmania antigens or anti-idiotypic reagents as vaccines can be considered as candidates for immunoprophylaxis in natural hosts of Leishmania parasites. We present a new method for producing Leishmania antigenic preparations which is of considerable interest, since it can be proposed for immunotherapy and prevention of other parasitic, bacterial, viral and perhaps, retroviral diseases.

Animals↗
PubMed1989

[Application of solar disinfection to drinking water in tropical regions].

Since unsafe water elicits a broad spectrum of bacteriological, parasitological and virological diseases, purification of polluted drinking water has to be developed in tropical rural regions. Around 70% of rural wells and 7% of bore-holes contain water unsafe for human consumption. Water is also contaminated during transport and storage. Several techniques of purification have been recommended to protect drinking water. Recently, sterilisation in the U. V. or simply in the sun rays has been systematically tested. In tropical rural areas, solar disinfection has given questionable results. It affords no guarantee for the health of the consumer in contrast with other techniques as chlorination.

Communicable Disease Control↗
PubMed1989

[Large-scale production of amastigotes by a human monoblastoid cell line].

In this study, a human monoblastoid cell line (TPH-1) was tested in vitro for the production of Leishmania amastigotes. The number of TPH1 cells increased with time and 6 days after promastigote infection the percentage of infected cells was around 45%. Pre-treatment of TPH1 cells with retinoic acid induced the cells to differentiate into unreplicating macrophage-like cells. Ninety per cent was parasitized 6 days after promastigote infection; the number of amastigotes quintuplied during this period of time; this result was irrespective of the Leishmania species used for experiments. Viable and infective parasites were obtained from treated and nontreated cells. TPH1 cells merit further consideration for research concerning new molecules active against Leishmania.

Animals↗
PubMed1988

Inoculation of BALB/c mice against Leishmania major infection with Leishmania-derived antigens isolated by gel filtration.

Gel filtration can be used as a substitute for preparative polyacrylamide gel electrophoresis in the preparation of an immunogenic, partly purified, fraction isolated from lysates of Leishmania promastigotes. This fraction, the molecular weight of which ranged from 70,000 to 53,000, when administered to BALB/c mice in associated with muramyl dipeptide induced resistance against cutaneous leishmaniasis.

Animals↗
PubMed1988

In vitro assessment of anti-Leishmania immunity of man acquired with a vaccine.

Monocytes, obtained from a human volunteer immunized with a Leishmania infantum-derived vaccine, when cultured in vitro displayed a strong parasiticidal activity against L. major promastigotes. In addition, immune serum conferred leishmanicidal activities to monocytes of normal, unexposed donors, and to murine macrophages.

Animals↗
PubMed1988

Vaccination and treatment trials against murine leishmaniasis with semi-purified Leishmania antigens.

Antigens with molecular weight ranges of 94-67 kDa (LiF2), 30-20 kDa (LiF5), or below 20 kDa (LiF6), isolated from lysates of Leishmania infantum promastigotes by electroelution from polyacrylamide gels were injected into mice which were genetically either partially resistant (C57BL/6) or susceptible (BALB/c) to Leishmania infection. One month after the completion of the intravenous (C57BL/6) or subcutaneous (BALB/c) schedules, the mice were challenged with 1 x 10(3) L. major promastigotes. All mice immunized with LiF2, LiF5 and LiF6 were completely resistant. Furthermore, the C57BL/6 mice immunized with LiF2 resisted a second challenge with 1 x 10(4) L. major amastigotes. 5 months later, LiF2 antigen was used for immunotherapy of L. major leishmaniasis; parasites disappeared from the treated skin lesions, although ensuing systemic infection could not be averted.

Animals↗