Background And Aims: There is ongoing debate about whether offspring perform best next to phylogenetically distantly related adult neighbours (due to the scarcity of enemies and competitors) or next to closely related adults (due to the abundance of mutualists). Here we hypothesise that relatedness of adult neighbours affects which traits confer performance rather than performance itself.
Methods: We studied seed removal, seed germination and sapling growth in Sessile Oaks (Quercus petraea and hybrids), and how they depend on size, shape and other traits, under both closely and distantly related canopies, manipulating offspring-density, presence of insects, and fungi, and spatial proximity to oaks.
Background And Aims: Mammals and molluscs (MaM) are abundant herbivores of tree seeds and seedlings, but how the trees and their environment affect MaM herbivory has been little studied. MaM tend to move much larger distances during the feeding stage than the more frequently studied insect herbivores. We hypothesize that MaM (1) select and stay within the patches that promise to be relatively the richest in seeds and seedlings, i.
View Article and Find Full Text PDFOuagadougou, the capital city of Burkina Faso, was recognized as a focus of zoonotic cutaneous leishmaniosis in April 2000. Leishmania major was the only strain isolated in this focus. We conducted a prospective study to detect L.
View Article and Find Full Text PDFExperimental studies about Leishmania resistance to metal and antifolates have pointed out that gene amplification is one of the main mechanisms of drug detoxification. Amplified genes code for adenosine triphosphate-dependent transporters (multidrug resistance and P-glycoproteins P), enzymes involved in trypanothione pathway, particularly gamma glutamyl cysteine synthase, and others involved in folates metabolism, such as dihydrofolate reductase and pterine reductase. The aim of this study was to detect and quantify the amplification of these genes in clinical strains of visceral leishmaniasis agents: Leishmania infantum, L.
View Article and Find Full Text PDFSince 1996, the number of cases of cutaneous leishmaniasis has increased dramatically in Ouagadougou. Leishmania major, zymodeme MON74 was the only strain isolated in this focus. An epidemiological study of the phlebotomine sandflies fauna has been undertaken.
View Article and Find Full Text PDFVisceral and cutaneous leishmaniases are heterogenous entities. The Leishmania species that a given patient harbors usually cannot be determined clinically, and this identification is essential to prescribe the best species-specific therapeutic regimen. Our diagnosis procedure includes a real-time PCR assay targeted at the 18S rRNA gene, which detects all Leishmania species but which is not specific for a given Leishmania species.
View Article and Find Full Text PDFTravel Med Infect Dis
March 2006
Background: Procalcitonin (PCT) has been found elevated in complicated forms of Plasmodium falciparum malaria. Its usefulness has almost never been assessed in uncomplicated falciparum malaria.
Method: We assessed diagnostic and prognostic value of PCT in a prospective series of 25 adults with uncomplicated P.
Ann Trop Med Parasitol
October 2003
This review emphasises the particular difficulties encountered in confirming a suspected case of cutaneous or visceral leishmaniasis when that case is co-infected with HIV. HIV infection appears to have a more profound impact on the development of visceral leishmaniasis than on the evolution of the purely cutaneous disease. The various techniques available for immunological, parasitological and molecular diagnosis are presented and evaluated.
View Article and Find Full Text PDFBetween 1986 and 2000, 381 Leishmania strains isolated from 288 HIV-positive patients were studied at the international cryobank in Montpellier, France. Most (95.1%) of the strains came from cases of visceral leishmaniasis but 4.
View Article and Find Full Text PDFThe incidence of cutaneous leishmaniasis (CL) has increased in Ouagadougou, Burkina Faso since 1996. A study was carried out from September to November 2000 to determine the impact of HIV on this outbreak. Of 74 CL patients, 10 were co-infected with HIV.
View Article and Find Full Text PDFThe activities of free atovaquone (ATV) and of poly(D,L-lactide) nanocapsules loaded with the drug, in the treatment of mice with visceral leishmaniasis caused by Leishmania infantum, were compared. Each mouse was infected intravenously with 2x10(7) promastigotes, on day 0. On days 15, 17 and 19, most of the infected mice were treated either with free ATV, in a dimethylsulphoxide/cremophor/water mixture, or with the ATV-loaded nanocapsules (at, respectively, 0.
View Article and Find Full Text PDFAnn Trop Med Parasitol
December 2002
Four human cases of localized cutaneous leishmaniasis caused by Leishmania naiffi are reported. Two of the cases were infected in French Guiana, one in French Guiana or Martinique, and the other in Ecuador or Peru. The geographical distribution of L.
View Article and Find Full Text PDFNanocapsules with atovaquone concentration of 1,000 micrograms/ml were prepared according to the interfacial deposition technique using different polymers: poly- epsilon -caprolactone (PECL), poly(lactic acid) (PLA) and poly(lactic-co-glycolic acid) (PLAGA). The following characteristics of nanoparticles were determined: percentage of encapsulation of atovaquone, percentage of encapsulation of benzyl benzoate (BB), nanoparticle size, nanoparticle wall thickness, suspension pH, and in vitro stability. The different formulations showed similar characteristics: maximal percentage of encapsulation (100%), particle size of approximately 230 nm, neutral pH and wall thickness of approximately 20 nm.
View Article and Find Full Text PDFAtovaquone, an antiparasitic agent, could possibly represent an alternative therapy after relapse following classical treatment for visceral leishmaniasis. Atovaquone-resistant strains were selected in vitro by stepwise drug pressure to study the mechanism of resistance in Leishmania. Characteristics of a promastigote strain resistant to 250 microg/ml of atovaquone were compared with those of the wild type (WT) strain.
View Article and Find Full Text PDFThe authors report the results of a survey on the efficacy against mosquito bites of a repellent, Mousticologne Spécial Zones Infestées (DEET 20%, EHD 15%). Two forms of the product, spray and gel, were tested in Senegal. Repellent efficacy was evaluated by exposing volunteers, both repellent-treated and untreated, to mosquito bites.
View Article and Find Full Text PDFClin Diagn Lab Immunol
July 2001
The parasitic loads of mouse livers experimentally infected with Leishmania infantum were determined using a double real-time quantitative PCR test targeted to the parasite DNA polymerase gene and to the mouse brain-derived neutrophic factor gene. The Leishmania DNA copy number was normalized to the number of mouse gene copies in order to quantify the former independently of liver weight. The correlation coefficient with the microtitration method was 0.
View Article and Find Full Text PDFAntimicrob Agents Chemother
September 2000
Sodium stibogluconate (Sbb), a leishmanicidal drug, was studied for its in vivo effect on the formation of reactive oxygen species (ROS), assessed by chemiluminescence (CL) in the whole blood of mice infected with Leishmania infantum. Stimulation of ROS formation induced ex vivo by zymosan particles or the protein kinase C activator phorbol myristate acetate (PMA) was reduced by approximately 25% (P < 0.05) after infection of mice.
View Article and Find Full Text PDFThe use of drug delivery systems may reduce the toxicity and improve the activity of anti-leishmanial compounds. The activity of atovaquone (ATV)-loaded liposomes was compared by determination of median effective doses (ED(25) and ED(50)), with that of free ATV in a murine model of visceral leishmaniasis induced by Leishmania infantum. On day 0, mice were infected intravenously with 4.
View Article and Find Full Text PDFLiver and spleen volumes and serum concentrations of nitrate (the end-product of NO in vivo), albumin, gamma-globulin, protein, creatine and urea were measured during the course of progressive infections with Leishmania infantum MON-1 (MHOM/PR/93/CRE29) in 10 Syrian golden hamsters. Each hamster was infected by intraperitoneal injection with 4 x 10(7) promastigotes. Five of the infected animals were treated, with 6 mg liposomal amphotericin B (L-AmB)/kg given by intracardiac injection, on day 107 post-infection (p.
View Article and Find Full Text PDFThis work describes the preparation, the physicochemical properties, the tolerance and the intracellular trafficking of pentamidine loaded nanoparticles. Pentamidine was bound to the polymer by ionic interaction. This interaction involved the carboxylic acid functions of methacrylic acid (10% of the polymer) and the amine groups of the drug.
View Article and Find Full Text PDFAntimicrob Agents Chemother
August 1998
Amphotericin B (AmB) has been used as a second-line treatment of visceral leishmaniasis, particularly in human immunodeficiency virus-positive patients. AmB median effective doses (ED50s) were determined on an isolate obtained before any treatment and on a second isolate obtained 4 years later from the same AmB-treated patient. ED50s were similar (0.
View Article and Find Full Text PDFThe activity of pentamidine-loaded poly(D,L-lactide) nanoparticles was compared, by determination of median effective doses (ED50), to that of free pentamidine in a murine model of visceral leishmaniasis induced by Leishmania infantum. BALB/c mice were infected intravenously on day O with promastigotes and then treated on days 14, 16, and 18. Groups of 5 mice received either 0.
View Article and Find Full Text PDFThe use of drug delivery systems may reduce the toxicity and improve the activity of antileishmanial compounds. In view of such a strategy, we loaded the antileishmanial agent pentamidine on polymethacrylate nanoparticles. The activity of pentamidine-loaded nanoparticles was compared with that of free pentamidine in a BALB/c mice model of visceral leishmaniasis induced by Leishmania infantum.
View Article and Find Full Text PDFAntimicrob Agents Chemother
August 1997
The efficacy of a new liposomal formulation of amphotericin B was compared to that of amphotericin B deoxycholate (Fungizone) in a murine model of visceral leishmaniasis induced by Leishmania infantum. Median effective doses (ED50) were determined with two different strains: strain 1 was obtained from an untreated patient, and strain 2 was obtained from a patient who had received 12.5 g of amphotericin B over 3 years.
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