Abstract: ABSTRACT: BACKGROUND: Malaria parasites (Plasmodium sp.), including new species, have recently been discovered as low grade mixed infections in three wild chimpanzees (Pan troglodytes schweinfurthii) sampled randomly in Kibale National Park, Uganda. This suggested a high prevalence of malaria infection in this community. The clinical course of malaria in chimpanzees and the species of the vectors that transmit their parasites are not known. The fact that these apes display a specific behaviour in which they consume plant parts of low nutritional value but that contain compounds with anti-malarial properties suggests that the apes' health might be affected by the parasite. The avoidance of the night-biting anopheline mosquitoes is another potential behavioural adaptation that would lead to a decrease in the number of infectious bites and consequently malaria. METHODS: Mosquitoes were collected over two years using suction-light traps and yeast-generated CO2 traps at the nesting and the feeding sites of two chimpanzee communities in Kibale National Park. The species of the female Anopheles caught were then determined and the presence of Plasmodium was sought in these insects by PCR amplification. RESULTS: The mosquito catches yielded a total of 309 female Anopheles specimens, the only known vectors of malaria parasites of mammalians. These specimens belonged to 10 species, of which Anopheles implexus, Anopheles vinckei and Anopheles demeilloni dominated. Sensitive DNA amplification techniques failed to detect any Plasmodium-positive Anopheles specimens. Humidity and trap height influenced the Anopheles capture success, and there was a negative correlation between nest numbers and mosquito abundance. The anopheline mosquitoes were also less diverse and numerous in sites where chimpanzees were nesting as compared to those where they were feeding. CONCLUSIONS: These observations suggest that the sites where chimpanzees build their nests every night might be selected, at least in part, in order to minimize contact with anopheline mosquitoes, which might lead to a reduced risk in acquiring malaria infections.
Abstract: A three-year retrospective analysis of fungi isolated from specimens of patients with superficial fungal infections in French Guiana is presented. Clinical samples from 726 patients with presumptive diagnoses of onychomycosis (28.2% of the patients), tinea capitis (27.8%), superficial cutaneous mycoses of the feet (22.0%), and of other areas of the body (21.9%), were assessed by microscopic examination and culture. Dermatophytes accounted for 59.2% of the isolates, followed by yeasts (27.5%) and non-dermatophytic molds (13.1%). Trichophyton rubrum was the most common dermatophyte recovered from cases of onychomycosis (67.4%), tinea pedis (70.6%) and tinea corporis (52.4%). In contrast, Trichophyton tonsurans was the predominant species associated with tinea capitis (73.9%). Yeasts were identified as the principal etiologic agents of onychomycosis of the fingernails (74.2%), whereas molds were found mainly in cases of onychomycosis of the toenails. In such instances, Neoscytalidium dimidiatum (70.8%) was the most common mold recovered in culture. In conclusion, the prevalence of T. rubrum and the occurrence of onychomycosis and fungal infections of the feet in French Guiana are similar to results reported from Europe, whereas the frequency of tinea capitis and the importance of T. tonsurans in such infections are similar to the situation in the Americas.
Abstract: Cerebral malaria (CM) is the most severe complication of Plasmodium falciparum malaria. The aim of this study was to investigate the influence of CM on the cerebral uptake of mefloquine (MQ), in an experimental model of mice infected with Plasmodium berghei ANKA (PbA). Drug diffusion in brain is closely related to efflux pumps such as P-glycoprotein (P-gp/ABCB1/MDR1) and Breast Cancer Resistant Protein (BCRP/ABCG2), two major components of the blood-brain barrier (BBB) which can be modified by inflammation and/or infection. After a single IP dose, MQ concentrations were measured by liquid chromatography in blood and brains of mice infected with Plasmodium berghei ANKA and compared with that of non-infected mice. Our results show that MQ brain concentrations were decreased in CM mice versus healthy mice (0.77 versus 1.31 for brain/plasma concentrations). Although MQ is transported out of endothelial cells by P-glycoprotein, this result cannot be related to this transporter as we have previously shown that CM does not alter P-gp function (personal data). CM induces a reduction of MQ brain transport and, therefore, an increase of central toxicity due to MQ should not be expected during CM.
Abstract: Since 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. Collections of sandflies have been carried out in six areas of the town during one year with two intensive collections at the end of the dry (May-June) and wet seasons (September-October). The only species of genus Phlebotomus captured was P. duboscqi. This represented 11.2% from the 4,676 collected sandflies. P. duboscqi is a well known vector of L. major, nevertheless, none of the collected sandflies were infected with L. major. 16 species of Sergentomyia were present in the south area of Ouagadougou and S. schwetzi was the most abundant sandfly.
Abstract: Thirty-eight isolates (including 28 isolates from patients) morphologically identified as Lichtheimia corymbifera (formerly Absidia corymbifera) were studied by sequence analysis (analysis of the internal transcribed spacer [ITS] region of the ribosomal DNA, the D1-D2 region of 28S, and a portion of the elongation factor 1alpha [EF-1alpha] gene). Phenotypic characteristics, including morphology, antifungal susceptibility, and carbohydrate assimilation, were also determined. Analysis of the three loci uncovered two well-delimited clades. The maximum sequence similarity values between isolates from both clades were 66, 95, and 93% for the ITS, 28S, and EF-1alpha loci, respectively, with differences in the lengths of the ITS sequences being detected (763 to 770 bp for isolates of clade 1 versus 841 to 865 bp for isolates of clade 2). Morphologically, the shapes and the sizes of the sporangiospores were significantly different among the isolates from both clades. On the basis of the molecular and morphological data, we considered isolates of clade 2 to belong to a different species named Lichtheimia ramosa because reference strains CBS 269.65 and CBS 270.65 (which initially belonged to Absidia ramosa) clustered within this clade. As neotype A. corymbifera strain CBS 429.75 belongs to clade 1, the name L. corymbifera was conserved for clade 1 isolates. Of note, the amphotericin B MICs were significantly lower for L. ramosa than for L. corymbifera (P < 0.005) but were always <or=0.5 microg/ml for both species. Among the isolates tested, the assimilation of melezitose was positive for 67% of the L. ramosa isolates and negative for all L. corymbifera isolates. In conclusion, this study reveals that two Lichtheimia species are commonly associated with mucormycosis in humans.
Abstract: An intraspecific study on Phlebotomus papatasi, the main proven vector of Leishmania major among the members of the subgenus Phlebotomus, was performed. The internal transcribed spacer 2 (ITS 2) of rDNA and the ND4 gene of mt DNA were sequenced from 26 populations from 18 countries (Albania, Algeria, Cyprus, Egypt, Greece, India, Iran, Israel, Italy, Lebanon, Morocco, Saudi Arabia, Spain, Syria, Tunisia, Turkey, Yugoslavia and Yemen), and compared. Samples also included three other species belonging to the subgenus Phlebotomus: P. duboscqi, a proven vector of L. major in the south of Sahara (three populations from Burkina Faso, Kenya and Senegal), P. bergeroti, a suspected vector of L. major (three populations from Oman Sultanate, Iran and Egypt), and one population of P. salehi from Iran. A phylogenetic study was carried out on the subgenus Phlebotomus. Our results confirm the validity of the morphologically characterized taxa. The position of P. salehi is doubtful. Variability in P. papatasi contrasts with that observed within other species having a wide distribution like P. (Paraphlebotomus) sergenti in the Old World or Lutzomyia (Lutzomyia) longipalpis in the New World. Consequently, it could be hypothesized that all populations of P. papatasi over its distribution area have similar vectorial capacities. The limits of the distribution area of L. major are correlated with the distribution of common rodents acting as hosts of the parasites.
Abstract: We report an uncommon clinical presentation of a unique case of fatal invasive fungal cerebral vasculitis due to Arthrographis kalrae in a nonimmunocompromised host. The identity of the fungus was determined by morphological characteristics and by analysis of internal transcribed spacer 1 sequences and was confirmed by postmortem examination of the brain tissues. Establishing rapidly the link between the clinical syndromes and the fungal infection of the central nervous system is essential to improve the outcome. As our case has shown, it is more challenging to make a diagnosis of fungal infection when there are no risk factors of immunodeficiency and when the clinical presentation seems uncommon.
Abstract: Aspergillus species are filamentous fungi of Ascomycete class. They are opportunistic pathogens frequently responsible for many severe infections. Among these species Aspergillus fumigatus is the most important human pathogen because of his thermophilic feature. Concerning microscopic morphology Aspergillus fumigatus is characterized by an asexual multiplication with a conidiophore formed by a conical-shaped vesicle. The phialides are directly attached to this clavated vesicle (uniseriate) and produce conidia chains. We report the case of mycological examination identifying a non uniseriate Aspergillus strain which belongs to Fumigati section.
Abstract: Under experimental conditions, Plasmodium berghei infection causes cerebral malaria (CM) in susceptible strains of mice such as C57BL/6 and CBA/Ca, whereas BALB/c or DBA/2J strains serve as a model for CM-resistant mice. The aim of the present study was to investigate the susceptibility of the CF1 mouse strain, carrying a spontaneous mutation of the mdr1a gene, to infection with Plasmodium berghei ANKA (PbA). The mdr1a gene codes for P-glycoprotein (P-gp/ABCB1), an efflux pump that is one of the major components of the blood-brain barrier. P-gp effluxes a broad range of xenobiotics from the brain to blood, preventing accumulation and toxicity in the central nervous system. CFI mdr1a (-/-) mice are used to investigate drug transport by efflux pumps. Because many antimalarial agents are effluxed by P-gp (mefloquine, quinine), it was important to determine whether CF1 mice can develop cerebral malaria to predict drug toxicity during cerebral malaria. Our work showed that CF1 mdr1a (-/-) mice are susceptible to PbA. CF1 and C57BL/6N mice (the reference strain) infected with PbA have similar profiles with regard to clinical signs, brain histological lesions, and brain macrophagic activation observed by immunohistological methods.
Abstract: Debaryomyces hansenii is a hemiascomycetous yeast commonly found in natural substrates and in various types of cheese. Pichia guilliermondii is widely distributed in nature and is a common constituent of the normal human microflora. Both species have been described in human infections but are extremely difficult to differentiate phenotypically. Thus, frequent errors in identification occur. The 62 clinical and environmental isolates sent between 2000 and 2007 to the French National Reference Center for Mycoses and Antifungals as D. hansenii or P. guilliermondii were analyzed by using the carbon assimilation pattern, the presence of pseudohyphae, and sequencing of the ITS and D1/D2 regions of the rRNA gene. The objective of this study was to assess using nucleotide sequences whether phenotypic identification was accurate and whether phenotypic characteristics could be used to differentiate the two species when sequencing was not available. We found that 58% of the isolates were misidentified and belong to seven different species: P. guilliermondii, P. caribbica, P. jadinii, D. hansenii, Candida palmioleophila, C. haemulonii type II, and Clavispora lusitaniae. In conclusion, D. hansenii may not be as common a human pathogen as previously thought. Sequencing of either ITS or D1/D2 regions is a good tool for differentiating the species more frequently confused with D. hansenii, keeping in mind that reliable databases should be used.
Abstract: An alkaloidal extract of the leaves of Melochia odorata exhibited antifungal activity against Candida albicans, Cryptococcus neoformans and Saccharomyces cerevisiae using a TLC bioautographic method. Bioassay-guided fractionation of this extract using separation by normal and reverse high-performance liquid chromatography (HPLC) resulted in the isolation of two active compounds identified as frangulanine, a cyclic peptide alkaloid, and waltherione-A, a quinolinone alkaloid.
Abstract: Between March 2000 and December 2001 a survey of the sand flies (Diptera: Phlebotominae) of French Guiana was carried out during 14 nights of captures with CDC light-traps and Malaise traps, and resulted in the collection of 2245 individuals of 38 species. The most abundant species were Lutzomyia (Trichophoromyia) ininii Floch & Abonnenc, Lu.(Psychodopygus) squamiventris maripaensis Floch & Abonnenc, and Lu .(Nyssomyia) flaviscutellata Mangabeira. Half of the collected sand flies females were dissected under field conditions and five species were found harboring Leishmania-like parasites. The Leishmania (Kinetoplastidae: Trypanosomatidae) species were identified by molecular typing, and for the first time Lu. (Nys.) flaviscutellata was found harboring Leishmania (Viannia) guyanensis and Lu. (Tri) ininii harboring unknown Leishmania. The first record for French Guiana of Lu. (Psy.) squamiventris maripaensis harboring L. (V.) naiffi, was also reported. The patterns of diversification of the human cutaneous leishmaniasis transmission in French Guiana are discussed.
Abstract: Mucormycosis is an emerging infection associated with a high mortality rate. Identification of the causative agents remains difficult and time-consuming by standard mycological procedures. In this study, internal transcribed spacer (ITS) sequencing was validated as a reliable technique for identification of Zygomycetes to the species level. Furthermore, species identification directly from infected tissues was evaluated in experimentally infected mice. Fifty-four Zygomycetes strains belonging to 16 species, including the most common pathogenic species of Rhizopus spp., Absidia spp., Mucor spp., and Rhizomucor spp., were used to assess intra- and interspecies variability. Ribosomal DNA including the complete ITS1-5.8S-ITS2 region was amplified with fungal universal primers, sequenced, and compared. Overall, for a given species, sequence similarities between isolates were >98%. In contrast, ITS sequences were very different between species, allowing an accurate identification of Zygomycetes to the species level in most cases. Six species (Rhizopus oryzae, Rhizopus microsporus, Rhizomucor pusillus, Mucor circinelloides, and Mucor indicus) were also used to induce disseminated mucormycosis in mice and to demonstrate that DNA extraction, amplification of fungal DNA, sequencing, and molecular identification were possible directly from frozen tissues.
Abstract: Description of a new tropical species of French Guiana: Lutzomyia (Trichopygomyia) depaquiti. The principal character is the aedeagus morphology that presents lateral expansions like a marine anchor. An other particularity is centered on the complex paramere with a lateral lobe. Holotype is deposited at the National Museum of Natural History of Paris.
Abstract: Our aim in this study was to observe the movements of filarial infective larvae following inoculation into the mammalian host and to assess the effect of vaccination on larval migration, in situ. Here we present recordings of larvae progressing through the subcutaneous tissues and inguinal lymph node of primary infected or vaccinated mice. We used the filaria Litomosoides sigmodontis in BALB/c mice that were necropsied 6 hours after the challenge inoculation of 200 larvae. Subcutaneous tissue sections were taken from the inoculation site and larvae were filmed in order to quantify their movements. Our analyses showed that the subcutaneous larvae were less motile in the vaccinated mice than in primary-infected mice and had more leucocytes attached to the cuticle. We propose that this reduced motility may result in the failure of a majority of larvae to evade the inflammatory reaction, thereby being a possible mechanism involved in the early vaccine-induced protection.
Abstract: During a brief entomological survey carried out in Ouagadougou, Burkina Faso, in March 2002, 178 phlebotomine sand flies (Diptera, Psychodidae) were caught using CDC miniature light traps. They were identified as Phlebotomus duboscqi Neveu-Lemaire, P. longicuspis Nitzulescu, Sergentomyia adleri (Theodor), S. affinis vorax (Parrot), S. antennata (Newstead), S. bedfordi (Newstead), S. christophersi (Sinton), S. fallax (Parrot), S. magna (Sinton) and S. schwetzi (Adler, Theodor & Parrot). This is the first record south of the Sahara of P. longicuspis sensu lato. This proven vector of Leishmania infantum Nicolle is a species closely related to P. perniciosus. It was identified by morphology and by the sequencing of a fragment of mitochondrial cytochrome b. There was 100% sequence homology with typical Tunisian specimens, and all characters identified the specimen as P. longicuspis sensu stricto. Epidemiological and biogeographical consequences are discussed.
Abstract: Zanthoxylum chiloperone var. angustifolium was investigated. Alkaloids 1-3 from the canthin-6-one series were characterized. Derivatives 7-28 were prepared by hemisynthesis or total synthesis. All compounds were tested for in vitro antifungal activities against five pathogenic fungal strains. Analogues of canthin-6-one did not show better antifungal activities.
Abstract: Candida glabrata is one of the most important causes of nosocomial fungal infection. We investigated, using a multiplex PCR, three polymorphic microsatellite markers, RPM2, MTI, and ERG3, in order to obtain a rapid genotyping method for C. glabrata. One set of primers was designed for each locus, and one primer of each set was dye labeled to read PCR signals using an automatic sequencer. Eight reference strains including other Candida species and 138 independent C. glabrata clinical isolates were tested. The clinical isolates were collected from different anatomical sites of adult patients either hospitalized in different wards of two different hospitals or not hospitalized. Since C. glabrata is haploid, one single PCR product for each PCR set was obtained and assigned to an allele. The numbers of different alleles were 5, 7, and 15 for the RPM2, MTI, and ERG3 loci, respectively. The number of allelic associations was 21, leading to a discriminatory power of 0.84. The markers were stable after 25 subcultures, and the amplifications were specific for C. glabrata. A factorial correspondence analysis did not indicate any correlation between the 21 multilocus genotypes and the clinical data (source, sex, ward, anatomical sites). Microsatellite marker analysis is a rapid and reliable technique to investigate clinical issues concerning C. glabrata. However, its discriminatory power should be improved by testing other polymorphic microsatellite loci.
Abstract: Over the past decade, an increasing number of opportunistic mycelial fungal infections have been reported in immunocompromised patients. Presented here is the first reported case of Microascus trigonosporus pneumonia, which occurred in a 24-year-old-man with a history of allogenic bone marrow transplantation with graft-versus-host disease. Despite the administration of effective antifungal treatment, the patient died after uncontrollable respiratory failure and multiorgan failure developed. This report confirms the results of previous studies that suggested a very poor outcome for bone marrow transplant recipients with non-Aspergillus mould infections.
Abstract: Adrenalin was used to investigate in vivo the circulation of the different stages of rodent Plasmodium present in the blood. A single dose of adrenalin injected to mice infected with P. yoelii resulted immediately in i) a diminution of the parasitaemia of approximately 50% in the peripheral large vessels (estimated in tail blood films), as well as in the capillaries (estimated in smears of blood collected from a fed Anopheles), and ii) an increased parasitaemia in blood collected by cardiac puncture from the right heart. The numbers of young stages of P. yoelii in the peripheral blood were initially somewhat reduced but, unexpectedly, midterm trophozoites were preferentially expelled from the peripheral blood into major organs like the heart. With P. vinckei, parasitaemia decreased only when midterm trophozoites predominated, and with P. chabaudi no effect was observed at any time. We propose that midterm trophozoites, by their increased surface area, as compared to rings, and their flexibility which contrasts with the rigid schizonts, are particularly susceptible to haemodynamic perturbations.
Abstract: Itraconazole is a fungistatic agent that, although highly lipophilic, shows poor transport through the blood brain barrier that may be due to efflux proteins. The combined administration of an efflux inhibitor with itraconazole should increase cerebral itraconazole concentrations and therefore, improve the treatment of Cryptococcus neoformans meningitis with this antifungal agent. To test this hypothesis, we have studied the influence of murine cerebral infection with C. neoformans and the inhibition of efflux by intraperitoneal injection of a P-glycoprotein inhibitor, GF120918 [N-(4-[2-(1,2,3,4-tetrahydro-6,7-dimethoxy-2-isoquinolinyl)-ethyl]-phenyl)9,10-dihydro-5-methoxy-9-oxo-4-acridine carboxamide], on the pharmacokinetics of itraconazole in plasma and brain after a single intraperitoneal itraconazole injection. We also investigated the influence of efflux inhibition on the efficacy of repeated doses of itraconazole in this murine model. The results showed that in healthy and infected mice pretreated or not with GF120918, plasma itraconazole values of area under the curve (AUC) were similar. In contrast, cerebral values of AUC were higher in infected mice compared with healthy mice. Moreover, the pretreatment of infected mice with GF120918 significantly increased cerebral itraconazole values of area under the curve and decreased weight loss in the treatment with itraconazole of a cerebral infection with C. neoformans.
Abstract: An alkaloidal extract of the stem barks of Zanthoxylum chiloperone var. angustifolium exhibited antifungal activity against Candida albicans, Aspergillus fumigatus and Trichophyton mentagrophytes var. interdigitale using a TLC bioautographic method. Bioassay-guided fractionation of this extract resulted in the isolation of two active compounds identi fi ed as canthin-6-one and 5-methoxycanthin-6-one. Canthin-6-one exhibited a broad spectrum of activities against Aspergillus fumigatus, A. niger, A. terreus, Candida albicans, C. tropicalis, C. glabrata, Cryptococcus neoformans, Geotrichum candidum, Saccharomyces cerevisiae, Trichosporon beigelii, Trichosporon cutaneum and Trichophyton mentagrophytes var. interdigitale with MICs values between 5.3 and 46 micro mol/L. 5-methoxy-canthin-6-one was active against only Trichophyton mentagrophytes var. interdigitale with a MIC value of 12.3 micro mol/L.
Abstract: Changes in the parasitaemia and the characteristics of parasitic infection for three species of rodent Plasmodium (P. chabaudi chabaudi, P. vinckei petteri and P. yoelii yoelii) were investigated under conditions of stress and after treatment with pentoxifylline (POF), a drug that increases red blood cell deformability and causes peripheral vasodilatation. The results indicated that under stress, late parasite stages became less abundant in the tail blood of mice. These changes might be the consequence of parasite sequestration. Attempts to assess sequestration intensity were made by measuring the release rate (RR) of late stages for 10,000 red blood cells. The RR is given by the product of the parasitaemia (P) by the percentage of old trophozoites (OT) and schizonts (S) in the peripheral blood: RR = P(%OT + %S) . With all three species, RR decreased considerably within 5 min following the manipulation of the mice. Injections of POF had the opposite effect. POF had a protective effect against infection by P.v. petteri, causing a delay of 48 h in the development of infection and a higher survival rate in treated mice.
Abstract: Three surveys on canine leishmaniasis were carried out in Cyprus (1993, 1998 and 1999) emphasise the presence of eleven species of phlebotomine sandflies: Phlebotomus (Phlebotomus) papatasi, P. (Paraphlebotomus) alexandri, P. (Pa.) jacusieli (first mention in Cyprus), P. (Pa.) sergenti, P. (Larroussius) galilaeus, P. (L.) tobbi, P. (Transphlebotomus) economidesi, P. (T.) mascittii, Sergentomyia (Sergentomyia) azizi (its specific statute is validated by the authors), S. (S.) fallax et S. (S.) minuta. P. (Adlerius) kyreniae was not caught during the surveys. The authors propose hypothesis of settlement of the island by phlebotomine sandflies according this species inventory. A first migration period took probably place during the Miocene time and a second one during the Pleistocene time.
Abstract: The aim of the studv was to evaluate the capacity of poly(isohexylcyanoacrylate) nanospheres to concentrate 3'-azido 3'-deoxythymidine (AZT) in the intestinal epithelium and associated immunocompetent cells, which are known to be one of the major reservoirs of the human immunodeficiency virus (HIV).
Abstract: During two surveys conducted in Cyprus (August 1998 and September 1999), 2,910 phlebotomine sandflies females were caught by CDC miniature light traps then dissected under binocular and examined on microscope. Eleven species were identified: Phlebotomus papatasi, P. sergenti, P. jacusieli, P. alexandri, P. tobbi, P. galilaeus, P. mascittii, P. economidesi, Sergentomyia fallax, S. minuta et S. azizi. The Larroussius species (P. galilaeus and P. tobbi) are the most abundant (more than 60% of our captures). Promastigotes were isolated from one specimen identified as P. tobbi. A Leishmania stock was successfully cultured and identified by isoenzyme characterisation as belonging to L. infantum zymodeme MON 1. The same zymodeme was isolated and identified from four dogs too. Because of the absence of usual vectors of L. infantum in the eastern part of the Mediterranean basin (P. neglectus and P. syriacus), and according to its distribution in Cyprus, P. tobbi constitute certainly a good local vector. It seems to be not very anthropophilic, that could explain the very few human cases.
Abstract: Semisynthetic derivatives were prepared from two natural annonaceous acetogenins, rolliniastatin-1 and squamocin, and their cytotoxicity was evaluated. Amino derivatives show decreased bioactivity. Isorolliniastatin-1 was found to be much less toxic than rolliniastatin-1 after intraperitoneal administration to mice, although the in vitro cytotoxicity of both compounds was comparable.
Abstract: Fluoroalkyl ethers (4) of dihydroartemisinin (2) have been prepared by reaction of fluoroalkyl alcohols with dihydroartemisinin by different methods (BF3,Et2O or TMSCl catalysis or Mitsunobu reaction). Ethers 4a-d derived from primary fluoroalkyl alcohols were obtained in moderate to good yields by these methods. Ethers 4e-j have been prepared from fluoroalkyl secondary and tertiary alcohols and phenol using the Mitsunobu reaction. Although in vitro antimalarial activities of ethers toward Plasmodium falciparum W-2 asiatic strain are moderate, in vivo activities against Plasmodium berghei (NT 173) are excellent.
Abstract: A high-performance liquid chromatographic method was developed for the specific determination of 2-n-propylquinoline, a new anti-leishmaniasis drug, in plasma and liver homogenates of mice. 2-n-Propylquinoline was extracted with methyl-tert.-butyl ether with quinoline as internal standard. Separation was carried out using a Nucleosil C18 column. The mobile phase consisted of methanol-0.005 M ammonium acetate buffer (60:40) at pH 5.5 and 8 for plasma and liver homogenates, respectively. Detection was monitored at 233 nm. The method was validated and shown to be accurate and precise for plasma and liver homogenates. Extraction yield was 96% in plasma and 81% in liver homogenates. This method was used to determine the pharmacokinetic profile of 2-n-propylquinoline following oral administration to mice.
Abstract: We have evaluated the in vivo antiplasmodial activity of six 2-substituted quinolines and a total alkaloidal extract of Galipea longiflora. BALB/c mice infected with Plasmodium vinckei petteri were treated orally at single dose of 50 mg/kg with quinolines or extract. Contrary to the previous results obtained with the Leishmania murine infection, 2-n-pentylquinoline showed activity against P. vinckei petteri. This result seems to confirm the antimalarial efficacy of infused stem bark of G. longiflora.
Abstract: The objective of this study was to investigate the chronobiology and infectivity of the gametocytes of Plasmodium chabaudi chabaudi. In order to increase the production of gametocytes, mice were treated with phenylhydrazine to induce a hyper-reticulocytosis. The authors observed an important stimulation of gametocytogenesis. Gametocytes were seen as soon as the second day postinoculation and were produced periodically at each schizogony, every 24 hr. The gametocytic developmental cycle lasted 60 hr and consisted of 4 successive stages: stage 0 at 36 hr, from merozoite invasion, stage I at 42 hr, stage II at 48 hr, and stage III at 54 hr. An important fraction of stage II was sequestered in small peripheral capillaries. The numbers of oocysts in the mosquitoes fed on phenylhydrazine-treated mice were larger than in controls. When mosquitoes were fed at different times of the day, circadian differences in the oocyst counts were not statistically significant. However, stage II was considered to be probably the most infective stage because, like the infective gametocyte stage of other species of murine malaria, it is sequestered in the peripheral capillaries. In contrast with Plasmodium vinckei, there is no peak of infectivity at the time of sequestration of the infective stage; this is probably due to the inhibitory effect of the schizogony occurring at this time.
Abstract: Gametocyte production by P. vinckei petteri was cyclic, occurring at each schizogony every 24 h. They matured in 27 h from merozoite to type 0 microgametocyte, in 3 h from type 0 to type I, 6 h from type I to type II and 3 h from type II to type III. Transmission experiments showed that the time of maximum infectivity was midday when mice were inoculated at midnight, and midnight when mice were inoculated at midday. In all instances, maximum infectivity coincided with a peak in intensity by type II microgametocytes, a relationship confirmed by multiple correspondence analysis. The proportion of type II microgametocytes was higher in the mosquitoes blood meal than in smears of tail blood of mice, suggesting a sequestration phenomenon with this stage.
Abstract: Both sexes of Lutzomyia legerae n. sp., a new species of phlebotomine sand fly belonging to the subgenus Lutzomyia, cruciata complex, are described from specimens collected in peridomestic environment, by light-trap, in central Nicaragua. Females of the new species are very close to L. cruciata. Therefore, in the leishmaniasis foci where the two species occur sympatrically implication of each species as a vector has to be carefully investigated.
Abstract: Potent antileishmanial activity has recently been described in vivo when certain 2-substituted quinoline alkaloids are administered to mice with cutaneous leishmaniasis. We now report the antileishmanial activity of four 2-substituted quinoline alkaloids, namely chimanine D or 2-(1',2'-trans-epoxypropyl) quinoline (I), 2-n-propylquinoline (II), 2-styrylquinoline (III) and 2-(2'-hydroxypropyl) quinoline (IV), for experimental treatment of visceral leishmaniasis in infected BALB/c mice. Subcutaneous treatment with chimanine D for 10 days at 0.54 mmol/kg per day resulted in 86.6% parasite suppression in the liver. Oral administration of 0.54 mmol/kg of 2-n-propylquinoline once daily for 5 or 10 days to L. donovani-infected mice suppressed parasite burdens in liver by 87.8 and 99.9%, respectively. Cutaneous administration of meglumine antimonate for 10 days resulted in 97.4% parasite suppression in the liver. This study is, to our knowledge, the first to demonstrate the activity of 2-substituted quinoline alkaloids in experimental treatment of visceral leishmaniasis. Further biological and chemical studies of these products might yet prove helpful for the development of new antileishmanial drugs.
Abstract: Lutzomyia trapidoi, the more abundant anthropophilic species, is a presumed leishmaniasis vector in the Pacific foothills of Ecuador. Three biotopes have been sampled (dwelling, and nearby coffee crop and primary forest) in the focus of Paraiso Escondido, by human bait catches, from August 1991 to October 1992. A large number of sandflies, 6,965 specimens, have been dissected to estimate peri and hypopyloric infections. All the peripyloric infections, characterized by isoenzyme electrophoresis, were Leishmania panamensis. The percentage of these infections was low, around 3%, but they were massive. They occurred only in dry season. Hypopyloric infections were observed in Lu. trapidoi all the year round in the three biotopes. Their percentage was high, reaching 40%. Despite of many trials to cultivate the parasite on NNN medium, no stain could be isolated. It is suggested that the parasite could be L. equatorensis.
Abstract: The efficacy of albendazole-ivermectin combination was tested an adult and developing stages of Molinema dessetae in the rodent Proechimys oris. Albendazole and ivermectin, both given alone, suramin and diethylcarbamazine were used as reference compounds. The drug combination (albendazole at 10 mg/kg/ day x 5 days and Ivermectin at 0.04 mg/kg/day x 5 days) was effective against infective larvae and preadult worms, and substantially reduced the number of live adult worms. The known filaricidal agents, diethylcarbamazine (400 mg/kg twice daily x 5 days), ivermectin (0.2 mg/kg/day x 5 days), and suramin (40 mg/kg/day x 5 days), as well as albendazole (50 mg/kg/day x 5 days) were active on infective larvae, preadult worms, microfilariae and adult worms. All drugs had the same level of efficacity on infective larvae. Albendazole had the highest efficacy against adult and preadult worms and diethylcarbamazine was the most active on microfilariae. Although the drug combination was not as effective against preadult and adult worms as albendazole alone, the results indicate that albendazole-ivermectin combination at a low dose had prophylactic effect and suggest a possible macrofilaricidal activity.
Abstract: The macrofilaricidal effect of albendazole in association with ivermectin was assessed in the rodent Proechimys oris, infected with Molinema dessetae. The drug combination was given to five rodents 190 days after infection. A similar group was used as control. The doses administered were 10 mg per kg for albendazole and 0.04 mg per kg for ivermectin over five days. The histological examination of intra-peritoneal nodules done six weeks after therapy revealed a clear-cut macrofilaricidal effect. The number of dead worms was significantly higher in the treated group. The histological examination revealed a lesion pattern that was related to the drug exposure. This consisted of nodules, each containing a necrotic worm that had its morphology preserved and was surrounded by a foreign body granuloma. This lesion was only seen in the treated group. A pattern related with the spontaneous death of worms was also observed. The results obtained here show the importance that albendazole-ivermectin combination could have in human filariasis therapy. Further studies in man should be done to confirm the macrofilaricidal effect of this drug combination in human filariasis.
Abstract: The microfiladermia of Monanema martini was studied in two natural murid hosts, Lemniscomys striatus and Arvicanthis niloticus, with 137 and 39 rodents respectively inoculated once, twice or several times. Microfilarial densities (mf/mm2) were measured at the ear pinna every three months. Almost all the rodents developed a microfiladermia. When L. striatus rodents were inoculated once with 30, 80, or 400 infective larvae, microfiladermia increased (peaks of 108, 148, 174 mf/mm2 respectively, at six to nine months p.i.); this fits with the fact that, in this filaria-host pair, the number of adult filariae is proportional to the number of inoculated larvae, and remains at a constant level for more than eight months. Nevertheless microfiladermia was limited, especially during the peak, showing the complexity of its regulatory mechanisms. Several low doses over one year, resulting in 145 L3, increased the microfiladermia at the same level than one dose of 400 larvae; the recovery rate of the larvae was reduced but the total number of filariae recovered was increased. A. niloticus, from which the filarial strain originates, showed a much lower microfiladermia than L. striatus (7 mf/mm2 with 80 larvae, at six months p.i.). This was due to a smaller recovery rate of the infective larvae in this host and, overall, to a reduced fertility of the female worms and a shorter lifetime of adult filariae. However, repeated inoculations increased the microfiladermia (32 mf/mm2), due to the constant presence of small numbers of young filariae producing microfilariae. It is to be noted that the two biological systems presented by M. martini in L. striatus and A. niloticus correspond to the two types of ocular pathology described in a recent opthalmological study, chorioretinal atrophy and keratitis respectively.
Abstract: Over 100 million persons suffer from diseases caused by filariae infestation, and one billion are at risk. A simple isolation method for both analytical and preparative separation is presented. Based on the simplest field-flow fractionation technique, the gravitational one, effective isolation of microfilariae is achieved. Microfilariae are eluted in the void volume of the channel without pollution by red blood cells. The red blood cell elution peak shows a total absence of microfilariae, as demonstrated after fraction collection and microscopic investigation. The elution mode of microfilariae and red blood cells appears to be a steric one, as confirmed by a reinjection experiment. The simplicity, low cost and the relatively short time required for this separation (10 min) indicate that gravitational field-flow fractionation could become a new separation tool for screening of microfilariae. With both live and dead microfilariae, the high recovery (66-80%) allows preparative fractionation for diagnostic purposes or fundamental research.
Abstract: In Meriones unguiculatus, the recovery rate of 80 inoculated larvae was low (about 20%) and irregular. In the natural host Lemniscomys striatus, the recovery rate was about 50% with inoculated doses of 30, 80 or 400 L3, but slightly higher for 400 L3. This rate was constant from day 2 to month 8 post infection (p.i.). When 7-9 reinoculations were performed in one year, the recovery rate of the late inoculation was of only 14%. After subcutaneous inoculations, larvae penetrated into the peripheric lymphatic vessels from hour 6 p.i. and migrated to the lumbar and mesenteric lymph nodes; this first migratory phase was achieved 5 days p.i. Later, the larvae migrated into the digestive tract lymphatic system. Filarial localization did not depend upon the L3 dose: half were found in the caecum and anterior colon (3 cm) wall, and half were distributed in the posterior colon, mesentery and small intestine. A small number (3-5%) of the filariae were found in the pulmonary blood vessels, as a result of accidental migration by the thoracic canal. A similar phenomenon is known in the lymphatic filariae Brugia spp. in rodents and Conispiculum flavescens in a lizard. Several arguments suggest that the genus Monanema is fundamentally lymphatic. Migrations and life of filariae in the lymphatic system seems to be more usual than it is generally admitted. In onchocerciasis, this may at least partially explain the lymphopathology of the inguinal region.
Abstract: The filarial rodent model Molinema dessetae/Proechimys oris, recently adapted in the laboratory allows studies on the host/parasite relationships. Development of filarial worm was described elsewhere, and the model standardized. Biological, parasitological data and antifilarial drug response were determined. Natural models can seldom be used in laboratory; in non natural models many informations on the host-parasite relationships are lost and pathological studies can only be fragmentary and punctual. With inbred Proechimys oris we have the possibility to investigate with a natural filarial model. Three rodent groups have been studied for over a period of one year. The first group comprises eleven parasite free animals; the second one, eight rodents infected once by L3, and the last with eight rodents regularly re-infected during the period of experiment. Several biological parameters were considered: weight, total red and white blood cell counts, haemoglobinemia, mean cell volume, differential leucocyte count, blood urea nitrogen, total serum proteins and electrophoretic pattern, endogenous creatinine clearance, circulating immune complexes. On the whole, more than 19,700 biological data were obtained and several multivariate statistical analysis were necessary for a valid interpretation. The Principal Component Analysis (ACP) shows in each infected rodent distinct trajectories related either with the age of the host or with the filarial infection itself. Three graphic methods were used: individual graphics of each rodent, graphics of each rodent group and, individual and group statistical center of gravity. At the end of the experiments, the rodents were autopsied and a detailed histological study of the whole body was made. Different lesions and stages of inflammatory processes found were analysed and classified as follows: granulomatous nodule with eosinophilic and neutrophilic polymorphs; foreign-body granulomatous nodule; sclerocicatricial nodule; mononucleate cell infiltrate. Secondary pathological alterations, such as irritative lesions and blocage of lymph and blood vessels, were found. A comprehensive study of all our qualitative histological results was performed by a second multivariate analysis: the Correspondence Analysis (AFC). This analysis confirmed the heterogeneity of each Proechimys infected and multi-infected groups. The cross checking between the ACP and AFC allows the separation of two physiopathological filarial groups; the first group (A) is characterized by moderate biological variations and the absence of hepatosplenic lesions.(ABSTRACT TRUNCATED AT 400 WORDS)
Abstract: Dipetalonema dessetae in Proechimys oris is a new model of rodent feafilariasis with several interesting features with respect to its utilisation in antifilarial pharmacology. 1. In the first part of these studies, it has been shown that the final host of the filaria, a rodent, was easy to breed. A prolific mosquito Aedes aegypti was an effective vector, and with the selected mode of infection i.e. 200 infesting larvae subcutaneously injected, 80% of the rodents were infected. 2. From 90 to 150 days p.i., the microfilaria count increased and reach a plateau which was maintained during 60 days. This plateau has enabled the evaluation of microfilaricidal activity. A drug exhibited a significative (0,10) microfilaricidal activity in two animals if the microfilaremia were reduced to 87% and 83,6% of pretreatment values, two or six weeks after treatment. 3. Identically, a compound would present a significative (0,12) macrofilaricidal effect if not a single male and not more than 1,6 female filaria were found at the autopsy of both animals six weeks after treatment. Activity on immature worms (3rd and 4th instar larvae, young adults) was qualitatively evaluated by the presence or absence of filaria at the autopsy of rodents which have been treated at various dates depending of the stages. 4. The sensitivity of this model was evaluated with several known antifilarial drugs, some of them unused by human patients. Diethylcarbamazine, levamisole, suramin, mebendazole and flubendazole killed adults, microfilariae and infesting larvae. Mel W was mainly macrofilaricidal and trichlorfon active on mf. Among all laboratory filariae, D. dessetae in P. oris is one of the most sensitive rodent models and, as such, would serve for the primary screening of new chemical compounds and for the pharmacological studies of antifilarial drugs.
Abstract: The host-parasite relationship between Schistosoma mansoni and the snail Biomphalaria glabrata is so complex that its experimental study needs some particularly working methods: for instance molluscan organs and tissue's cultures. In the experiment described we report that digestive gland's cells cultures were grown on synthetic cultural medium. This one contained a physiological salt solution and a basal nutrient medium consisting of foetal calf serum, chicken embryo extract and amino-acids. In this case we observed good growth and multiplication of the digestive gland cells. This preliminary experiment has to be used in immunological studies regarding the origin and the mode of acquisition of the snail antigen by the cercariae membrane.
