What's new for 'Trypanosomatids' in PubMed

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Sent on Monday, 2011 Jan 24
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 11

1.	J Clin Lab Anal. 2011;25(1):20-4. doi: 10.1002/jcla.20377. Direct diagnosis of Leishmania species on serosity materials punctured from cutaneous leishmaniasis patients using PCR-RFLP. Hajjaran H, Vasigheh F, Mohebali M, Rezaei S, Mamishi S, Charedar S. Department of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran. Abstract This study was aimed at identifying the Leishmania species using serosity materials punctured from skin lesions of cutaneous leishmaniasis (CL) patients by using internal transcribed spacer1 (ITS1) polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP). We used the PCR-RFLP on 60 parasitological confirmed CL patients who referred to leishmaniasis laboratory from the School of Public Health, Tehran University of Medical Sciences. The PCR-RFLP could correctly detect 51 Leishmania species of the 60confirmed positive specimens, where all the other 10 parasitological (microscopy and culture) negative samples that were prepared from other bacterial- and fungal-infected lesions had negative results. The results also revealed that Leishmania major was the dominant species (53.3%). This study suggests that the PCR-RFLP assay with serosity materials punctured from CL patients using Hae III enzyme is useful for the rapid identification of Leishmania species. J. Clin. Lab. Anal. 25:20-24, 2011. © 2011 Wiley-Liss, Inc. © 2011 Wiley-Liss, Inc.
	PMID: 21254238 [PubMed - in process]
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2.	J Bioenerg Biomembr. 2011 Jan 21. [Epub ahead of print] Ecto-phosphatases in protozoan parasites: possib le roles in nutrition, growth and ROS sensing. Cosentino-Gomes D, Meyer-Fernandes JR. Instituto de Bioquímica Médica, Universidade Federal do Rio de Janeiro, CCS, Bloco H, Cidade Universitária, Ilha do Fundão, 21941-590, Rio de Janeiro, RJ, Brazil. Abstract The cellular plasma membrane contains enzymes whose active sites face the external medium rather than the cytoplasm. The activities of these enzymes, referred to as ecto-enzymes, can be measured using living cells. Ecto-phosphatases are ecto-enzymes that presumably hydrolyze extracellular phosphorylated substrates, releasing free inorganic phosphate. Although, several alternative functions have been suggested for these enzymes, such as participation in proliferation, differentiation, adhesion, virulence, and infection, little is known about the physiological roles of these enzymes in protozoa parasites. In this review, we discuss the principal features of ecto-phosphatases in protozoan parasites that are causative agents of important diseases such as Chagas' disease, leishmaniasis, amoebiasis, giardiasis, trichomoniasis and, sleeping sickness.
	PMID: 21253843 [PubMed - as supplied by publisher]
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3.	PLoS Pathog. 2011 Jan 6;7(1):e1001246. Critical Role of IRF-5 in the Development of T helper 1 responses to Leishmania donovani infection. Paun A, Bankoti R, Joshi T, Pitha PM, Stäger S. Sidney Kimmel Comprehensive Center, The Johns Hopkins University, Baltimore, Maryland, United States of America. Abstract The transcription factor Interferon Regulatory Factor 5 (IRF-5) has been shown to be involved in the induction of proinflammatory cytokines in response to viral infections and TLR activation and to play an essential role in the innate inflammatory response. In this study, we used the experimental model of visceral leishmaniasis to investigate the role of IRF-5 in the generation of Th1 responses and in the formation of Th1-type liver granulomas in Leishmania donovani infected mice. We show that TLR7-mediated activation of IRF-5 is essential for the development of Th1 responses to L. donovani in the spleen during chronic infection. We also demonstrate that IRF-5 deficiency leads to the incapacity to control L. donovani infection in the liver and to the formation of smaller granulomas. Granulomas in Irf5(-/-) mice are characterized by an increased IL-4 and IL-10 response and concomitant low iNOS expression. Collectively, these results identify IRF-5 as a critical molecular switch for the development of Th1 immune responses following L. donovani infections and reveal an indirect role of IRF-5 in the regulation of iNOS expression. Free Article
	PMID: 21253574 [PubMed - in process]
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4.	J Biol Chem. 2011 Jan 20. [Epub ahead of print] A novel member of the RNase D exoribonuclease family functions in mitochondrial guide RNA metabolism in Try panosoma brucei. Zimmer SL, McEvoy SM, Li J, Qu J, Read LK. SUNY Buffalo School of Medicine, United States; Abstract RNA turnover and RNA editing are essential for regulation of mitochondrial gene expression in Trypanosoma brucei. RNA turnover is controlled in part by RNA 3' adenylation and uridylation status, with trans-acting factors also impacting RNA homeostasis. However, little is known about the mitochondrial degradation machinery or its regulation in T. brucei. We have identified a mitochondrial exoribonuclease, TbRND, whose expression is highly upregulated in the insect proliferative stage of the parasite. TbRND shares sequence similarity with RNase D family enzymes, but differs from all reported members of this family in possessing a CCHC zinc finger domain. In vitro, TbRND exhibits 3' to 5' exoribonuclease activity, with specificity towards uridine homopolymers, including the 3' oligo(U) tails of guide RNAs (gRNAs) that provide the sequence information for RNA editing. Several lines of evidence indicate that TbRND functions in gRNA metabolism in vivo. First, TbRND depletion results in gRNA tails extended by 2-3 nucleotides on average. Second, overexpression of wild-type but not catalytically inactive TbRND results in a substantial decrease in the total gRNA population, and a consequent inhibition of RNA editing. The observed effects on the gRNA population are specific since rRNAs, which are also 3' uridylated, are unaffected by TbRND depletion or overexpression. Finally, we show that gRNA binding proteins co-purify with TbRND. In summary, TbRND is a 3' to 5' exoribonuclease that appears to have evolved a function highly specific to the mitochondrion of trypanosomes. Free Article
	PMID: 21252235 [PubMed - as supplied by publisher]
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5.	Infect Genet Evol. 2011 Jan 17. [Epub ahead of print] Genetic exchange and emergence of novel strains in dir ectly transmitted trypanosomatids. Schmid-Hempel R, Salathé R, Tognazzo M, Schmid-Hempel P, Zürich E. Institute of Integrative Biology (IBZ), ETH-Zentrum CHN, Universitätsstrasse 16, CH-8092 Zürich, Switzerland. Abstract The breeding structure of protozoan infections, i.e. whether and how frequently parasites exchange genes ("sexual reproduction"), is a crucially important parameter for many important questions; it also matters for how new virulent strains might emerge. Whether protozoan parasites are clonal or sexual is therefore a hotly debated issue. For trypanosomatids, few experimental tests of breeding structure exist to date and are limited to the vector-borne human diseases Trypanosoma brucei, T. cruzi, and Leishmania major. We infected the natural host (Bombus terrestris) of the monoxenous parasite Crithidia bombi (Trypanosomatida) either with a single strain of the parasite or in mixed infections and tested for genetic exchange among co-infecting strains using microsatellite markers. We show that strains regularly exchange genetic material, with occasional self-crossing during mixed infections. Most offspring clones fit the expected allelic pattern from a standard Mendelian segregation. In some cases, alleles are lost or gained, leading to an entirely new genotype different from either parent. Genetic exchange in C. bombi therefore does occur and the process also leads to allelic loss or gain that could result from slippage during recombination. The majority of novel offspring types correspond to a recombination of parental alleles. The case of C. bombi demonstrates that directly transmitted, monoxenic trypanosomatids can also exchange genes. Sex therefore seems to be found in very different lineages of the trypanosomatids. Furthermore, the data allowed estimating a frequency at which C. bombi shows genetic exchange in populations. Copyright © 2011. Published by Elsevier B.V.
	PMID: 21252000 [PubMed - as supplied by publisher]
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6.	Int J Parasitol. 2011 Jan 17. [Epub ahead of print] Evidence incriminating midges (Diptera: Ceratopogonidae) as potential vectors of L eishmania in Australia. Dougall AM, Alexander B, Holt D, Harris T, Sultan AH, Bates PA, Rose K, Walton SF. Menzies School of Health Research, Charles Darwin University, Darwin, NT, 0810, Australia. Abstract The first autochthonous Leishmania infection in Australia was reported by Rose et al. (2004) and the parasite was characterized as a unique species. The host was the red kangaroo (Macropus rufus) but the transmitting vector was unknown. To incriminate the biological vector, insect trapping by a variety of methods was undertaken at two field sites of known Leishmania transmission. Collected sand flies were identified to species level and were screened for Leishmania DNA using a semi-quantitative real-time PCR. Collections revealed four species of sand fly, with a predominance of the reptile biter Sergentomyia queenslandi (Hill). However, no Leishmania-positive flies were detected. Therefore, alternative vectors were investigated for infection, giving startling results. Screening revealed that an undescribed species of day-feeding midge, subgenus Forcipomyia (Lasiohelea) Kieffer, had a prevalence of up to 15% for Leishmania DNA, with high parasitemia in some individuals. Manual gut dissections confirmed the presence of promastigotes and in some midges material similar to promastigote secretory gel, including parasites with metacyclic-like morphology. Parasites were cultured from infected midges and sequence analysis of the Leishmania RNA polymerase subunit II gene confirmed infections were identical to the original isolated Leishmania sp. Phylogenetic analysis revealed the closest known species to be Leishmania enriettii, with this and the Australian species confirmed as members of Leishmania sensu stricto. Collectively the results strongly suggest that the day-feeding midge (F. (Lasiohelea) sp. 1) is a potential biological vector of Leishmania in northern Australia, which is to our knowledge the first evidence of a vector other than a phlebotomine sand fly anywhere in the world. These findings have considerable implications in the understanding of the Leishmania life cycle worldwide. Copyright © 2011. Published by Elsevier Ltd.
	PMID: 21251914 [PubMed - as supplied by publisher]
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7.	Eur Ann Otorhinolaryngol Head Neck Dis. 2011 Jan 18. [Epub ahead of print] Unusual form of cutaneous leishmaniasis: Erysipeloid form. Mnejja M, Hammami B, Chakroun A, Achour I, Charfeddine I, Chakroun A, Turki H, Ghorbel A. Service ORL et chirurgie cervico-faciale, CHU Habib Bourguiba, 3029 Sfax, Tunisia. Abstract We report the epidemiological and clinical characteristics of the erysipeloid form of cutaneous leishmaniasis as well as its diagnostic and therapeutic challenges. CASE REPORT: A 63-year-old woman, with no medical history, presented with a one-month history of erythematous nasal swelling. The lesion appeared after an accidental trauma. Erythematous infiltrative plaque was noted on the center of the face. There were also crust formations on the traumatic region. Despite local treatment and oral antibiotherapy, there was no improvement. The diagnosis of cutaneous leishmaniasis was confirmed by positive skin smears. Histopathological examinations of a skin biopsy showed no malignancy. The patient was treated intramuscularly with 10mg/kg per day systemic meglumine antimoniate with partial regression of symptoms. CONCLUSION: The erysipeloid type is a rare and unusual presentation of cutaneous leishmaniasis that often causes late diagnosis. Diagnosis is confirmed by the demonstration of the parasite by skin smear, histopathological examination and polymerase chain reaction. There are various therapeutic options. The evolution is generally favourable. Copyright © 2011 Elsevier Masson SAS. All rights reserved.
	PMID: 21251895 [PubMed - as supplied by publisher]
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8.	Diagn Microbiol Infect Dis. 2011 Feb;69(2):205-9. Rapid and sensitive detection of human African trypanosomiasis by loop-mediated isot hermal amplification combined with a lateral-flow dipstick. Njiru ZK. Abstract A combined loop-mediated isothermal amplification lateral flow dipstick (LAMP-LFD) format was evaluated in the detection of human infective trypanosome DNA from clinical samples. The LAMP-LFD showed analytical sensitivity equivalent to 0.01 tryps/mL, levels that were identical to using gel electrophoresis and SYBR® Green I dye. The LAMP-LFD showed superior specificity to SYBR® Green I when supernatant prepared from boiled human biological samples was used as template. These results indicate that the use of nonspecific DNA intercalators may produce false positives when partially processed templates are used. The LAMP-LFD format presented here is simple, rapid, and has future potential use in diagnosis of sleeping sickness. Copyright © 2011 Elsevier Inc. All rights reserved.
	PMID: 21251567 [PubMed - in process]
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9.	Rev Biol Trop. 2010 Dec;58(4):1549-60. [Repellent activity of plant essential oils against bites of Lutzomyia migonei (Diptera: Psychodidae)]. [Article in Spanish] Nieves E, Fernández Méndez J, Lias J, Rondón M, Briceño B. LAPEX, Departamento de Biología, Facultad de Ciencias, Universidad de Los Andes, Mérida-Venezuela. nevelsa@ula.ve Abstract Natural repellents from plant extracts have demonstrated good efficacy against bites of some insect species. The present study evaluated the repellent effect of essential oils extracted from 8 plants species against bites of Lutzomyia migonei, the Leishmania vector. The essential oils were extracted by steam destillation in Clevenger chamber, from the following plants: Hyptis suaveolens, Pimenta racemosa, Piper marginatum, Monticalia imbricatifolia, Pseudognaphalium caeruleocanum, Espeletia shultzii, Plecthranthus amboinicus and Cinnamomun zeylanicum. Repellency tests were performed under laboratory conditions by the human hand method in cage assays, using female colonies of L. migonei. The more effective oils were tested at variable concentrations on different volunteers. The protection percentage and time were calculated. The results showed what oils of P. caeruleocanum and C. zeylanicum were the most effective. Although P. amboinicus oil also had repellent effect showed an irritant effect. The oils P. marginatum, H. suaveolens and P. racemosa showed no repellent effect, while the rest of oil extracts showed significant repellency in variable degrees. P. caeruleocanum and C. zeylanicum oils provided the 95% protection against bites of L. migonei for 3 h. The P. caeruleocanum oil showed the greatest protection time, with a mean over 4h and 3h at concentrations of 50% and 10% respectively. The results suggest that the P. caeruleocanum oil could represent a potential natural repellent against Leishmania vectors.
	PMID: 21250485 [PubMed - in process]
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10.	Vaccine. 2010 Oct 28;28(46):7414-9. Epub 2010 Sep 16. Effect of a combination DNA vaccine for the prevention and therapy of Trypanosoma cruzi i nfection in mice: role of CD4+ and CD8+ T cells. Limon-Flores AY, Cervera-Cetina R, Tzec-Arjona JL, Ek-Macias L, Sánchez-Burgos G, Ramirez-Sierra MJ, Cruz-Chan JV, VanWynsberghe NR, Dumonteil E. Laboratorio de Parasitología, Centro de Investigaciones Regionales Dr. Hideyo Noguchi, Universidad Autónoma de Yucatán, Mérida, Yucatán, Mexico. Abstract Chagas disease is a major public health problem, with about 10 million infected people, and DNA vaccines are a promising alternative for the control of Trypanosoma cruzi, the causing agent of the disease. We tested here a new DNA vaccine encoding a combination of two leading parasite antigens, TSA-1 and Tc24, for the prevention and therapy of T. cruzi infection. Immunized Balb/c mice challenged by T. cruzi presented a significantly lower parasitemia and inflammatory cell density in the heart compared to control mice. Similarly, the therapeutic administration of the DNA vaccine was able to significantly reduce the parasitemia and inflammatory reaction in acutely infected Balb/c and C57BL/6 mice, and reduced cardiac tissue inflammation in chronically infected ICR mice. Therapeutic vaccination induced a marked increase in parasite-specific IFNγ producing CD4(+) and CD8(+) T cells in the spleen as well as an increase in CD4(+) and CD8(+) T cells in the infected cardiac tissue. In addition, some effect of the DNA vaccine could still be observed in CD4-knockout C57BL/6 mice, which presented a lower parasitemia and inflammatory cell density, but not in CD8-deficient mice, in which the vaccine had no effect. These results indicate that the activation of CD8(+) T cells plays a major role in the control of the infection by the therapeutic DNA vaccine, and to a somewhat lesser extent CD4(+) T cells. This observation opens interesting perspectives for the potentiation of this DNA vaccine candidate by including additional CD8(+) T cell antigens/epitopes in future vaccine formulations. Copyright © 2010 Elsevier Ltd. All rights reserved.
	PMID: 20850536 [PubMed - indexed for MEDLINE]
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