What's new for 'Trypanosomatids' in PubMed

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Sent on Saturday, 2010 Jul 10
Search kinetoplastids OR kinetoplastid OR Kinetoplastida OR "trypanosoma brucei" OR leishmania OR brucei OR leishmaniasis OR "African trypanosomiasis"
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PubMed Results

Items 1 - 10 of 16

1.	Parasitol Res. 2010 Jul 9. [Epub ahead of print] Species discrimination and phylogenetic inference of 17 Chinese Leishmania isolates based on internal transcribed spacer 1 (ITS1) sequences. Yang BB, Guo XG, Hu XS, Zhang JG, Liao L, Chen DL, Chen JP. Department of Parasitology, West China School of Preclinical and Forensic Medicine, Sichuan University, Chengdu, 610041, Sichuan, China. Abstract Leishmaniasis is a geographically widespread disease, caused by protozoan flagellates of the genus Leishmania. This disease still remains endemic in China, especially in the west and northwest frontier regions. To date, the phylogenetic relationships among Chinese Leishmania isolates are still unclear, and the possible taxonomic diversity remains to be established. In this study, the ITS1-5.8S fragments of ten isolates collected from different foci in China were determined. To infer the phylogenetic relationships among them, seven sequences of Chinese Leishmania isolates retrieved from GenBank were also included. Both parsimony and Bayesian analyses reveal an unexpected but strongly supported clade comprising eight newly determined isolates, which is sister to other members of subgenus Leishmania. In combination with genetic distance analysis, this provides evidence of the occurrence of an undescribed species of Leishmania. Our results also suggest that (1) the isolate IPHL/CN/77/XJ771 from Bachu County, Xinjiang Uygur Autonomous Region is not Leishmania infantum but Leishmania donovani; (2) the status referring to an isolate MRHO/CN/88/KXG-2 from a great gerbil in Karamay as Leishmania turanica, formerly based on multilocus enzyme electrophoresis, is recognized; (3) an earlier finding demonstrating the L. donovani identity of isolate MHOM/CN/80/801 from Kashi city is corroborated; (4) the three isolates from eastern Jiashi County, Xinjiang Uygur Autonomous Region, causing desert type of zoonotic visceral leishmaniasis (see Wang et al., Parasitol Int (in press), 2010), belong to L. donovani instead of L. infantum. In addition, the results of this study make an important contribution to understanding the heterogeneity and relationships of Chinese Leishmania isolates, further indicating that the isolates from China may have had a more complex evolutionary history than expected.
	PMID: 20617444 [PubMed - as supplied by publisher]
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2.	Int J Environ Res Public Health. 2010 Mar;7(3):814-26. Epub 2010 Mar 5. Molecular epidemiology for vector research on leishmaniasis. Kato H, Gomez EA, Cáceres AG, Uezato H, Mimori T, Hashiguchi Y. Department of Veterinary Hygiene, Faculty of Agriculture, Yamaguchi University, Yamaguchi 753-8515, Japan. Abstract Leishmaniasis is a protozoan disease caused by the genus Leishmania transmitted by female phlebotomine sand flies. Surveillance of the prevalence of Leishmania and responsive vector species in endemic and surrounding areas is important for predicting the risk and expansion of the disease. Molecular biological methods are now widely applied to epidemiological studies of infectious diseases including leishmaniasis. These techniques are used to detect natural infections of sand fly vectors with Leishmania protozoa and are becoming powerful tools due to their sensitivity and specificity. Recently, genetic analyses have been performed on sand fly species and genotyping using PCR-RFLP has been applied to the sand fly taxonomy. In addition, a molecular mass screening method has been established that enables both sand fly species and natural leishmanial infections to be identified simultaneously in hundreds of sand flies with limited effort. This paper reviews recent advances in the study of sand flies, vectors of leishmaniasis, using molecular biological approaches.
	PMID: 20617005 [PubMed - in process]
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3.	J Biol Chem. 2010 Jul 8. [Epub ahead of print] The plasma membrane of bloodstream form African trypanosomes confers susceptibility and specificity to killing by hydrophobic peptides. Harrington JM, Widener J, Stephens N, Johnson T, Francia M, Capewell P, Macleod A, Hajduk SL. University of Georgia, United States; Abstract Trypanosoma brucei is the causative agent of both a veterinary wasting disease and human African trypanosomiasis, or sleeping sickness. The cellular membrane of the developmental stage found within the mammalian host, the bloodstream form (BSF), is highly dynamic, exhibiting rapid rates of endocytosis and lateral flow of GPI-anchored proteins. Here we show that the cell membrane of these organisms is a target for killing by small hydrophobic peptides that increase the rigidity of lipid bilayers. Specifically, we have derived trypanocidal peptides that are based upon the hydrophobic N-terminal signal sequences of human apolipoproteins. These peptides selectively partition into the plasma membrane of BSF trypanosomes resulting in an increase in the rigidity of the bilayer, dramatic changes in cell motility and subsequent cell death. No killing of the developmental stage found within the insect midgut, the procyclic form, was observed. Additionally the peptides exhibit no toxicity towards mammalian cell lines nor do they induce hemolysis. Studies with model liposomes indicate that bilayer fluidity dictates the susceptibility of membranes to manipulation by hydrophobic peptides. We suggest that the composition of the BSF trypanosome cell membrane confers a high degree of fluidity and unique susceptibility to killing by hydrophobic peptides and is therefore a target for the development of trypanocidal drugs.
	PMID: 20615879 [PubMed - as supplied by publisher]
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4.	An Pediatr (Barc). 2010 Jul 6. [Epub ahead of print] [Treatment of cutaneous leishmaniasis with liposomal amphotericin B.] [Article in Spanish] Del Rosal Rabes T, Baquero-Artigao F, Gómez Fernández C, García Miguel MJ, de Lucas Laguna R. Unidad de Enfermedades Infecciosas Pediátricas, Hospital Infantil La Paz, Madrid, España.
	PMID: 20615769 [PubMed - as supplied by publisher]
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5.	Bioorg Med Chem Lett. 2010 Jun 17. [Epub ahead of print] Selective delivery of 2-hydroxy APA to Trypanosoma brucei using the melamine motif. Klee N, Wong PE, Baragaña B, Mazouni FE, Phillips MA, Barrett MP, Gilbert IH. Division of Biological Chemistry and Drug Discovery, College of Life Science, University of Dundee, Sir James Black Centre, Dundee DD1 5EH, UK. Abstract Trypanosoma brucei, the parasite that causes human African trypanosomiasis, is auxotrophic for purines and has specialist nucleoside transporters to import these metabolites. In particular, the P2 aminopurine transporter can also selectively accumulate melamine derivatives. In this Letter, we report the coupling of the melamine moiety to 2-hydroxy APA, a potent ornithine decarboxylase inhibitor, with the aim of selectively delivering this compound to the parasite. The best compound described here shows an increased in vitro trypanocidal activity compared with the parent. Copyright © 2010 Elsevier Ltd. All rights reserved.
	PMID: 20615694 [PubMed - as supplied by publisher]
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6.	Vet Immunol Immunopathol. 2010 Jun 16. [Epub ahead of print] Canine leishmaniosis. Immunophenotyp ic profile of leukocytes in different compartments of symptomatic, asymptomatic and treated dogs. Alexandre-Pires G, de Brito MT, Algueró C, Martins C, Rodrigues OR, da Fonseca IP, Santos-Gomes G. CIISA, Faculdade de Medicina Veterinária, Av. Universidade Técnica, 1300-477 Lisboa, Portugal. Abstract Canine visceral leishmaniosis (CanL) is an emerging disease, expanding in various parts of the world. The infection caused by Leishmania, an intracellular protozoan parasite, can show different clinical manifestations, from asymptomatic or subclinical to symptomatic dogs, in which a wide spectrum of clinical signs is evident. The fact that the parasite replicates in different organs raises the hypothesis that each organ may have a specific immune response. The local immune responses should be evaluated and taken into consideration when developing prophylactic tools. Therefore, phenotypic characterization of peripheral blood, lymph node and bone marrow lymphocyte populations and the expression of class II molecules of major histocompatibility complex (MHCII) were performed in asymptomatic and symptomatic dogs and in dogs that had been diagnosed and treated for leishmaniosis. Our findings showed that blood and bone marrow lymphocytes from symptomatic dogs were highly activated. In bone marrow of asymptomatic and treated dogs, a high frequency of MHCII(+) lymphocytes was observed, as well as MHCII(+) monocytes in the treated group. These results show increased expression of MHCII molecules giving evidence for antigenic presentation mainly by lymphocytes. The symptomatic and treated dogs showed an expansion of CD4(+) T cells subpopulations in lymph nodes, revealing an important contribution of these cells in controlling local parasite replication. This study also underlines the eventual importance of CD3(+)CD4(-)CD8(-) (double negative) and CD3(+)CD4(+)CD8(+) (double positive) T cell subsets in sensing and controlling latent infections and their possible function in the immune dynamics during CanL. The specific cellular immune responses raised in different compartments where the parasite replicates seem to have variable effects on local parasite control, highlighting the complexity of the cellular immune response developed by the dog infected by Leishmania infantum. Copyright © 2010 Elsevier B.V. All rights reserved.
	PMID: 20615553 [PubMed - as supplied by publisher]
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7.	Vaccine. 2010 Jul 5. [Epub ahead of print] Fragments of antigen-loaded dendritic cells (DC) and DC-derived exosomes induce protective immunity against Leishmania major. Schnitzer JK, Berzel S, Fajardo-Moser M, Remer KA, Moll H. University of Würzburg, Institute for Molecular Infection Biology, Germany. Abstract Upon loading with parasite antigen and adoptive transfer, dendritic cells (DC) are able to confer protection against the protozoan parasite Leishmania major. In the present study, we investigated whether viable DC are required for inducing protection. We provide evidence that L. major antigen-loaded DC that had been fixed with paraformaldehyde or exposed to UV irradiation, and even disrupted cells, are able to serve as an effective vaccine. Furthermore, we demonstrate the potential of DC-derived exosomes to mediate protective immunity against cutaneous leishmaniasis. The route of antigen presentation to recipient T cells involves uptake of intravenously injected DC fragments into late endosomal compartments of splenic DC in the recipient. In vitro studies showed that DC fragments induce T-cell proliferation and interleukin 12 secretion by splenocytes. Together, these findings suggest that the development of a cell-free vaccine for immunoprophylaxis against leishmaniasis and other infectious diseases is feasible. Copyright © 2010. Published by Elsevier Ltd.
	PMID: 20615489 [PubMed - as supplied by publisher]
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8.	Vaccine. 2010 Jul 5. [Epub ahead of print] Epitope mapping of a common 57kDa antigen of Leishmania species by monoclonal antibodi es. Nejad-Moghaddam A, Abolhassani M. Hybridoma Lab., Dept. of Immunology, Pasteur Institute of Iran, Pasteur Ave., Tehran 13164, Iran. Abstract BALB/c mice were immunized with freeze-thawed promastigote of Leishmania infantum. Five monoclonal antibodies (mAb) were selected, four IgM (designated as P1A9, P2G8, P5E3 and P6B3) and one IgG1 (P3D2). ELISA and Western blot analysis suggested that all monoclonal antibodies are specific to a band of 57kDa antigen of L. infantum as well as other three Leishmania species (L. tropica, L. major and L. donovani). ELISA additivity tests revealed four epitopes on 57kDa antigen as defined by four IgM monoclonal antibodies. Three distinct epitopes were recognized by P1A9, P2G8, and P6B3 antibodies and one epitope recognized by P5E3 antibody that shared with P2G8, and P6B3 epitopes. The 57kDa protein was purified with affinity column and was shown to possess proteolytic activity. It seems that 57kDa protein is the major surface Leishmania antigen (gp63) that has been used as subunit vaccine with appropriate adjuvant and induced protection against L. major infection in BALB/c mice. Copyright © 2010. Published by Elsevier Ltd.
	PMID: 20615488 [PubMed - as supplied by publisher]
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9.	J Nat Prod. 2010 Jul 8. [Epub ahead of print] Antiprotozoal Steroidal Saponins from the Marine Sponge Pandaros acanthifolium. Regalado EL, Tasdemir D, Kaiser M, Cachet N, Amade P, Thomas OP. Department of Chemistry, Center of Marine Bioproducts (CEBIMAR), Loma y 37 Alturas del Vedado, C.P. 10400 Havana, Cuba, Centre for Pharmacognosy and Phytotherapy, Department of Pharmaceutical and Biological Chemistry, School of Pharmacy, University of London, 29-39 Brunswick Square, London WC1N 1AX, United Kingdom, Department of Medical Parasitology and Infection Biology, Swiss Tropical Institute, 4002, Basel, Switzerland, and Laboratoire de Chimie des Molecules Bioactives et des Aromes, UMR 6001 CNRS, Institut de Chimie de Nice, Faculte des Sciences, University of Nice-Sophia Antipolis, Parc Valrose, 06108 Nice Cedex 2, France. Abstract The chemical composition of the Caribbean sponge Pandaros acanthifolium was reinvestigated and led to the isolation of 12 new steroidal glycosides, namely, pandarosides E-J (1-6) and their methyl esters (7-12). Their structures were determined on the basis of extensive spectroscopic analyses, including two-dimensional NMR and HRESIMS data. Like the previously isolated pandarosides A-D (13-16), the new compounds 1-12 share an unusual oxidized D-ring and a cis C/D ring junction. The absolute configurations of the aglycones were assigned by interpretation of CD spectra, whereas the absolute configurations of the monosaccharide units were determined by chiral GC analyses of the acid methanolysates. The majority of the metabolites showed in vitro activity against three or four parasitic protozoa. Particularly active were the compounds 3 (pandaroside G) and its methyl ester (9), which potently inhibited the growth of Trypanosoma brucei rhodesiense (IC(50) values 0.78 and 0.038 muM, respectively) and Leishmania donovani (IC(50)'s 1.3 and 0.051 muM, respectively).
	PMID: 20614907 [PubMed - as supplied by publisher]
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10.	Nat Prod Commun. 2010 Jun;5(6):975-80. Constituents, antileishmanial activity and toxicity profile of volatile oil from berries of Croton macrostachyus. Tariku Y, Hymete A, Hailu A, Rohloff J. Department of Chemistry, College of Natural Science, Jimma University, P.O. Box 378, Jimma, Ethiopia. Abstract The chemical composition of the volatile oil from berries of Croton macrostachyus Hochst. ex Del. was determined by GC and GC/MS. The oil was tested for its in vitro antileishmanial activity on two Leishmania strains, and its toxicity on the human monocytic leukemia (THP-1) cell line and erythrocytes from sheep blood. The main constituents of the oil were benzyl benzoate (51.8%), linalool (10.1%), gamma-muurolene (9.3%), (E,E)-alpha-farnesene (3.2%), delta-cadinene (2.8%) and alpha-curcumene (2.7%). The oil was effective against L. donovani and L. aethiopica promastigotes (MIC = 0.08 microL/mL and 0.16 microL/mL, respectively) and axenic amastigote stages (EC50 = 20.00 nL/mL and 6.66 nL/mL, respectively). The CC50 value for the oil was 10.00 nL/mL on THP-1 cells with selectivity index values of 0.5 for L. donovani and 1.5 for L. aethiopica. The median lethal concentration (LC50) of the oil was 2.45 microL/mL. Thus the observed high efficacy and moderate toxicity of the volatile oil from C. macrostachyus, makes the plant a promising source of new lead compounds in the search for safe and effective antileishmanial drugs.
	PMID: 20614838 [PubMed - in process]
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