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Sent on Friday, 2012 January 20Search: kinetoplastids OR kinetoplastid OR Kinetoplastida OR "trypanosoma brucei" OR leishmania OR brucei OR leishmaniasis OR "African trypanosomiasis"
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| PubMed Results |
| 1. | Dermatoendocrinol. 2011 Oct;3(4):220-9. Epub 2011 Oct 1.Antimicrobial implications of vitamin D.Youssef DA, Miller CW, El-Abbassi AM, Cutchins DC, Cutchins C, Grant WB, Peiris AN.SourceMountain Home VAMC Medicine Service; Mountain Home; TN USA. AbstractEvidence exists that vitamin D has a potential antimicrobial activity and its deficiency has deleterious effects on general well-being and longevity. Vitamin D may reduce the risk of infection through multiple mechanisms. Vitamin D boosts innate immunity by modulating production of anti-microbial peptides (AMPs) and cytokine response. Vitamin D and its analogues via these mechanisms are playing an increasing role in the management of atopic dermatitis, psoriasis, vitiligo, acne and rosacea. Vitamin D may reduce susceptibility to infection in patients with atopic dermatitis and the ability to regulate local immune and inflammatory responses offers exciting potential for understanding and treating chronic inflammatory dermatitides. Moreover, B and T cell activation as well as boosting the activity of monocytes and macrophages also contribute to a potent systemic anti-microbial effect. The direct invasion by pathogenic organisms may be minimized at sites such as the respiratory tract by enhancing clearance of invading organisms. A vitamin D replete state appears to benefit most infections, with the possible noteworthy exception of Leishmaniasis. Antibiotics remain an expensive option and misuse of these agents results in significant antibiotic resistance and contributes to escalating health care costs. Vitamin D constitutes an inexpensive prophylactic option and possibly therapeutic product either by itself or as a synergistic agent to traditional antimicrobial agents. This review outlines the specific antimicrobial properties of vitamin D in combating a wide range of organisms. We discuss the possible mechanisms by which vitamin D may have a therapeutic role in managing a variety of infections. |
| 2. | J Antimicrob Chemother. 2012 Jan 18. [Epub ahead of print]Asiaticoside induces tumour-necrosis-factor-α-mediated nitric oxide production to cure experimental visceral leishmaniasis caused by antimony-susceptible and -resistant Leishmania donovani strains.Bhaumik SK, Paul J, Naskar K, Karmakar S, De T.SourceDivision of Infectious Disease and Immunology, Indian Institute of Chemical Biology, 4 Raja S. C. Mullick Road, Kolkata 700032, India. AbstractOBJECTIVES:The aim of this study was to investigate and characterize the efficacy of asiaticoside in an experimental model of visceral leishmaniasis caused by antimony-susceptible (AG83) and -resistant (GE1F8R and K39) Leishmania donovani. METHODS:The effect of asiaticoside was evaluated by microscopic counting of intracellular amastigotes in cultured macrophages stained with Giemsa. The antileishmanial effect of the compounds was assessed in infected BALB/c mice by estimation of splenic and liver parasite burdens in Leishman Donovan units. Cytokines were measured by real-time PCR and ELISA. Intracellular tumour necrosis factor-α (TNF-α) was measured by fluorescence-activated cell sorting. Nitric oxide was measured by the Griess reaction. RESULTS:Besides effectively inhibiting in vitro replication of the parasite within macrophages, asiaticoside treatment resulted in almost complete clearance of the liver and splenic parasite burden when administered at a dose of 5 mg/kg × 10 starting on day +30 of challenge with antimony-susceptible (AG83) and -resistant (GE1F8R and K39) L. donovani. Asiaticoside treatment was associated with a switch in the host from a Th2- to a Th1-type immune response accompanied by the induction of TNF-α-mediated nitric oxide production, all of which are important elements for macrophage function in antileishmanial defence mechanisms. CONCLUSIONS:These results suggest that oral therapy with asiaticoside shows promising antileishmanial efficacy in animals infected by antimony-susceptible (AG83) and -resistant (GE1F8R and K39) L. donovani. |
| 3. | RNA Biol. 2012 Jan 1;9(1). [Epub ahead of print]Pseudogenes are not pseudo any more.Wen YZ, Zheng LL, Qu LH, Ayala FJ, Lun ZR.SourceCenter for Parasitic Organisms, State Key Laboratory of Biocontrol, School of Life Sciences and Key Laboratory of Tropical Diseases and Control of the Ministry of Education, Zhongshan Medical School, Sun Yat-Sen University; Guangzhou, China. AbstractRecent significant progress towards understanding the function of pseudogenes in protozoa (Trypanosoma brucei), metazoa (mouse) and plants, make it pertinent to provide a brief overview on what has been learned about this fascinating subject. We discuss the regulatory mechanisms of pseudogenes at the post-transcriptional level and advance new ideas towards understanding the evolution of these, sometimes called "garbage genes" or "junk DNA," seeking to stimulate the interest of scientists and additional research on the subject. We hope this mini review can be helpful to scientists working or seeking to work on these and related issues. |
| 4. | Emerg Infect Dis. 2012 Jan;18(1):184-6. doi: 10.3201/eid1801.102001.Visceral Leishmaniasis during Italian Renaissance, 1522-1562.Nerlich AG, Bianucci R, Trisciuoglio A, Schönian G, Ball M, Giuffra V, Bachmeier B, Pusch CM, Ferroglio E, Fornaciari G.AbstractTO THE EDITOR: Leishmaniasis, an infectious disease caused by parasites of the genus Leishmania, is transmitted to humans through the bite of a female sandfly. The 3 forms of leishmaniasis are visceral (VL) and cutaneous (CL), which are typical of the Old World, and mucocutaneous leishmaniasis, which occurs primarily in Central and South America. VL (also called kala-azar) is caused by species of the L. donovani complex (including L. infantum), and CL is mainly caused by L. major or L. tropica (1). In Italy, VL and CL are caused by L. infantum. The origin and spread of leishmaniasis are a matter of debate. Widespread in antiquity, visceral leishmaniasis has been identified only in mummies from ancient Egypt and upper Nubia (2). Similarly, only 4 cases of mucocutaneous leishmaniasis have been identified in skulls from northern Chile (3). |
| 5. | Emerg Infect Dis. 2012 Jan;18(1):183-4. doi: 10.3201/eid1801.110408.Cutaneous leishmaniasis acquired in jura, france.Faber WR, Hoekzema R, Bart A, Zeegelaar JE, de Vries HJ.AbstractTO THE EDITOR: Cutaneous leishmaniasis is well established in the Mediterranean basin. However, the disease is spreading and new foci have been reported (1-3). Because of climate change, it is feasible that vector-borne diseases such as cutaneous leishmaniasis may spread northward into Europe (4). We report a patient who acquired cutaneous leishmaniasis while on holiday in Jura, France. |
| 6. | BMC Genomics. 2012 Jan 18;13(1):29. [Epub ahead of print]Centromere-associated repeat arrays on Trypanosoma brucei chromosomes are much more extensive than predicted.Echeverry MC, Bot C, Obado SO, Taylor MC, Kelly JM.AbstractABSTRACT: BACKGROUND:African trypanosomes belong to a eukaryotic lineage which displays many unusual genetic features. The mechanisms of chromosome segregation in these diploid protozoan parasites are poorly understood. Centromeres in Trypanosoma brucei have been localised to chromosomal regions that contain an array of ~147 bp AT-rich tandem repeats. Initial estimates from the genome sequencing project suggested that these arrays ranged from 2 - 8 kb. In this paper, we show that the centromeric repeat regions are much more extensive. RESULTS:We used a long-range restriction endonuclease mapping approach to more accurately define the sizes of the centromeric repeat arrays on the 8 T. brucei chromosomes where unambiguous assembly data were available. The results indicate that the sizes of the arrays on different chromosomes vary from 20 to 120 kb. In addition, we found instances of length heterogeneity between chromosome homologues. For example, values of 20 and 65 kb were obtained for the arrays on chromosome 1, and 50 and 75 kb for chromosome 5. CONCLUSIONS:Our results show that centromeric repeat arrays on T. brucei chromosomes are more similar in size to those of higher eukaryotes than previously suspected. This information provides a firmer framework for investigating aspects of chromosome segregation and will allow epigenetic features associated with the process to be more accurately mapped. |
| 7. | Cell Microbiol. 2012 Jan 19. doi: 10.1111/j.1462-5822.2012.01756.x. [Epub ahead of print]Trafficking and release of the metacyclic HASPB protein in the kinetoplastid parasite Leishmania.Maclean LM, O'Toole PJ, Stark M, Marrison J, Seelenmeyer C, Nickel W, Smith DF.SourceCentre for Immunology and Infection, Department of Biology/Hull York Medical School, University of York, York YO10 5YW, UK Technology Facility, Department of Biology, University of York, Heslington, York YO10 5YW, UK Heidelberg University Biochemistry Center, Im Neuenheimer Feld 328, 69120 Heidelberg, Germany. AbstractProteins of the Leishmania HASPB family are only expressed in infective parasites (both extra- and intracellular stages) and, together with the peripheral membrane protein SHERP, are essential for parasite differentiation (metacyclogenesis) in the sand fly vector. HASPB is a "non-classically" secreted protein, requiring N-terminal acylation for trafficking to and exposure on the plasma membrane. Here, we use live cell imaging methods to further explore this pathway to the membrane and flagellum. Unlike HASPB trafficking in transfected mammalian cells, we find no evidence for a phosphorylation-regulated recycling pathway in metacyclic parasites. Once at the plasma membrane, HASPB18-GFP can undergo bidirectional movement within the inner leaflet of the membrane and on the flagellum. Transfer of fluorescent protein between the flagellum and the plasma membrane is compromised, however, suggesting the presence of a diffusion barrier at the base of the Leishmania flagellum. Full-length HASPB is released from the metacyclic parasite surface on to macrophages during phagocytosis but while expression is maintained in intracellular amastigotes, HASPB cannot be detected on the external surface in these cells. Thus HASPB may be a dual function protein that is shed by the infective metacyclic but retained internally once Leishmania are taken up by macrophages. © 2012 Blackwell Publishing Ltd. © 2012 Blackwell Publishing Ltd. |
| 8. | PLoS Negl Trop Dis. 2011 Aug;5(8):e1272. Epub 2011 Aug 2.Analyses of 32 loci clarify phylogenetic relationships among Trypanosoma cruzi lineages and support a single hybridization prior to human contact.Flores-López CA, Machado CA.SourceDepartment of Biology, University of Maryland, College Park, MD, USA. AbstractBACKGROUND:The genetic diversity of Trypanosoma cruzi, the etiological agent of Chagas disease, has been traditionally divided in two major groups, T. cruzi I and II, corresponding to discrete typing units TcI and TcII-VI under a recently proposed nomenclature. The two major groups of T. cruzi seem to differ in important biological characteristics, and are thus thought to represent a natural division relevant for epidemiological studies and development of prophylaxis. To understand the potential connection between the different manifestations of Chagas disease and variability of T. cruzi strains, it is essential to have a correct reconstruction of the evolutionary history of T. cruzi. METHODOLOGY/PRINCIPAL FINDINGS:Nucleotide sequences from 32 unlinked loci (>26 Kilobases of aligned sequence) were used to reconstruct the evolutionary history of strains representing the known genetic variability of T. cruzi. Thorough phylogenetic analyses show that the original classification of T. cruzi in two major lineages does not reflect its evolutionary history and that there is only strong evidence for one major and recent hybridization event in the history of this species. Furthermore, estimates of divergence times using Bayesian methods show that current extant lineages of T. cruzi diverged very recently, within the last 3 million years, and that the major hybridization event leading to hybrid lineages TcV and TcVI occurred less than 1 million years ago, well before the contact of T. cruzi with humans in South America. CONCLUSIONS/SIGNIFICANCE:The described phylogenetic relationships among the six major genetic subdivisions of T. cruzi should serve as guidelines for targeted epidemiological and prophylaxis studies. We suggest that it is important to reconsider conclusions from previous studies that have attempted to uncover important biological differences between the two originally defined major lineages of T. cruzi especially if those conclusions were obtained from single or few strains. |
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| 9. | PLoS Negl Trop Dis. 2011 Aug;5(8):e1226. Epub 2011 Aug 2.How do tsetse recognise their hosts? The role of shape in the responses of tsetse (Glossina fuscipes and G. palpalis) to artificial hosts.Tirados I, Esterhuizen J, Rayaisse JB, Diarrassouba A, Kaba D, Mpiana S, Vale GA, Solano P, Lehane MJ, Torr SJ.SourceNatural Resource Institute, University of Greenwich, Chatham, Kent, United Kingdom. AbstractPalpalis-group tsetse, particularly the subspecies of Glossina palpalis and G. fuscipes, are the most important transmitters of human African trypanomiasis (HAT), transmitting >95% of cases. Traps and insecticide-treated targets are used to control tsetse but more cost-effective baits might be developed through a better understanding of the fly's host-seeking behaviour. Electrocuting grids were used to assess the numbers of G. palpalis palpalis and G. fuscipes quanzensis attracted to and landing on square or oblong targets of black cloth varying in size from 0.01 m(2) to 1.0 m(2). For both species, increasing the size of a square target from 0.01 m(2) (dimensions=0.1 × 0.1 m) to 1.0 m(2) (1.0 × 1.0 m) increased the catch ~4x however the numbers of tsetse killed per unit area of target declined with target size suggesting that the most cost efficient targets are not the largest. For G. f. quanzensis, horizontal oblongs, (1 m wide × 0.5 m high) caught ~1.8x more tsetse than vertical ones (0.5 m wide × 1.0 m high) but the opposite applied for G. p. palpalis. Shape preference was consistent over the range of target sizes. For G. p. palpalis square targets caught as many tsetse as the oblong; while the evidence is less strong the same appears to apply to G. f. quanzensis. The results suggest that targets used to control G. p. palpalis and G. f. quanzensis should be square, and that the most cost-effective designs, as judged by the numbers of tsetse caught per area of target, are likely to be in the region of 0.25 × 0.25 m(2). The preference of G. p. palpalis for vertical oblongs is unique amongst tsetse species, and it is suggested that this response might be related to its anthropophagic behaviour and hence importance as a vector of HAT. |
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| 10. | Protist. 2011 Jul;162(3):503-24. Epub 2011 Mar 21.Phylogenetic validation of the genera Angomonas and Strigomonas of trypanosomatids harboring bacterial endosymbionts with the description of new species of trypanosomatids and of proteobacterial symbionts.Teixeir a MM, Borghesan TC, Ferreira RC, Santos MA, Takata CS, Campaner M, Nunes VL, Milder RV, de Souza W, Camargo EP.SourceDepartment of Parasitology, ICB, University of São Paulo (USP), São Paulo, 05508-000, SP, Brazil. mmgteix@icb.usp.br AbstractWe comparatively examined the nutritional, molecular and optical and electron microscopical characteristics of reference species and new isolates of trypanosomatids harboring bacterial endosymbionts. Sequencing of the V7V8 region of the small subunit of the ribosomal RNA (SSU rRNA) gene distinguished six major genotypes among the 13 isolates examined. The entire sequences of the SSU rRNA and glycosomal glyceraldehyde phosphate dehydrogenase (gGAPDH) genes were obtained for phylogenetic analyses. In the resulting phylogenetic trees, the symbiont-harboring species clustered as a major clade comprising two subclades that corresponded to the proposed genera Angomonas and Strigomonas. The genus Angomonas comprised 10 flagellates including former Crithidia deanei and C. desouzai plus a new species. The genus Strigomonas included former Crithidia oncopelti and Blastocrithidia culicis plus a new species. Sequences from the internal transcribed spacer of ribosomal DNA (ITS rDNA) and size polymorphism of kinetoplast DNA (kDNA) minicircles revealed considerable genetic heterogeneity within the genera Angomonas and Strigomonas. Phylogenetic analyses based on 16S rDNA and ITS rDNA sequences demonstrated that all of the endosymbionts belonged to the Betaproteobacteria and revealed three new species. The congruence of the phylogenetic trees of trypanosomatids and their symbionts support a co-divergent host-symbiont evolutionary history. Copyright © 2011 Elsevier GmbH. All rights reserved. |
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