What's new for 'Trypanosomatids' in PubMed

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Sent on Tuesday, 2012 June 05
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 14

1.	PLoS One. 2012;7(5):e37341. Epub 2012 May 18. Lutzomyia umbratilis, the Main Vector of Leishmania guyanensis, Represents a Novel Species Complex? Scarpassa VM, Alencar RB. Source Coordenação de Biodiversidade, Instituto Nacional de Pesquisas da Amazônia, Manaus, Amazonas, Brazil. Abstract BACKGROUND: Lutzomyia umbratilis is an important Leishmania guyanensis vector in South America. Previous studies have suggested differences in the vector competence between L. umbratilis populations situated on opposite banks of the Amazonas and Negro Rivers in the central Amazonian Brazil region, likely indicating a species complex. However, few studies have been performed on these populations and the taxonomic status of L. umbratilis remains unclear. METHODOLOGY/PRINCIPAL FINDINGS: Phylogeographic structure was estimated for six L. umbratilis samples from the central Amazonian region in Brazil by analyzing mtDNA using 1181 bp of the COI gene to assess whether the populations on opposite banks of these rivers consist of incipient or distinct species. The genetic diversity was fairly high and the results revealed two distinct clades ( = lineages) with 1% sequence divergence. Clade I consisted of four samples from the left bank of the Amazonas and Negro Rivers, whereas clade II comprised two samples from the right bank of Negro River. No haplotypes were shared between samples of two clades. Samples within clades exhibited low to moderate genetic differentiation (F(ST) = -0.0390-0.1841), whereas samples between clades exhibited very high differentiation (F(ST) = 0.7100-0.8497) and fixed differences. These lineages have diverged approximately 0.22 Mya in the middle Pleistocene. Demographic expansion was detected for the lineages I and II approximately 30,448 and 15,859 years ago, respectively, in the late Pleistocene. CONCLUSIONS/SIGNIFICANCE: The two genetic lineages may represent an advanced speciation stage suggestive of incipient or distinct species within L. umbratilis. These findings suggest that the Amazonas and Negro Rivers may be acting as effective barriers, thus preventing gene flow between populations on opposite sides. Such findings have important implications for epidemiological studies, especially those related to vector competence and anthropophily, and for vector control strategies. In addition, L. umbratilis represents an interesting example in speciation studies.
	PMID: 22662146 [PubMed - in process]

2.	Front Immunol. 2012;3:128. Epub 2012 May 29. Protective immunity and vaccination against cutaneous leishmaniasis. Okwor I, Mou Z, Liu D, Uzonna J. Source Department of Medical Microbiology, University of Manitoba Winnipeg, MB, Canada. Abstract Although a great deal of knowledge has been gained from studies on the immunobiology of leishmaniasis, there is still no universally acceptable, safe, and effective vaccine against the disease. This strongly suggests that we still do not completely understand the factors that control and/or regulate the development and sustenance of anti-Leishmania immunity, particularly those associated with secondary (memory) immunity. Such an understanding is critically important for designing safe, effective, and universally acceptable vaccine against the disease. Here we review the literature on the correlate of protective anti-Leishmania immunity and vaccination strategies against leishmaniasis with a bias emphasis on experimental cutaneous leishmaniasis.
	PMID: 22661975 [PubMed - in process]

3.	Front Immunol. 2012;3:121. Epub 2012 May 21. Biomarkers for exposure to sand flies bites as tools to aid control of leishmaniasis. Andrade BB, Teixeira CR. Source Immunobiology Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health Bethesda, MD, USA. Abstract Intense research efforts so far have not been sufficient to reduce leishmaniasis burden worldwide. This disease is transmitted by bites of infected sand flies, which inject saliva in the host skin in an attempt to obtain a blood meal. Sand fly saliva has an array of proteins with diverse pharmacological properties that modulates the host homeostatic and immune responses. Some of these proteins are also immunogenic and can induce both cellular and humoral immune responses. Recently, the use of sand fly salivary proteins to estimate exposure to sand fly bites and consequently the risk of infection has emerged. Here, we review evidence that supports the use of the host immune responses against sand fly salivary proteins to estimate risk of infection. We also discuss how the use of recombinant salivary proteins can optimize serological surveys and provide guidance for the implementation of specific measures for disease control in endemic areas.
	PMID: 22661974 [PubMed - in process]

4.	J Biol Chem. 2012 Jun 1. [Epub ahead of print] Trypanosoma brucei 20S editosomes have one RNA substrate-binding site and execute RNA unwinding activity. Bohm C, Katari VS, Brecht M, Goringer HU. Source Darmstadt University of Technology, Germany. Abstract Editing of mitochondrial pre-mRNAs in African trypanosomes generates full-length transcripts by the site-specific insertion and deletion of U nucleotides. The reaction is catalyzed by a 0.8MDa multienzyme complex, the editosome. Although the binding of substrate pre-edited mRNAs and cognate gRNAs represents the first step in the reaction cycle, the biochemical and biophysical details of the editosome/RNA interaction are not understood. Here we show that editosomes bind full-length substrate mRNAs with nanomolar affinity in a nonselective fashion. The complexes do not discriminate - neither kinetically nor thermodynamically - between different mitochondrial pre-mRNAs or between edited and unedited versions of the same transcript. They also bind gRNAs and gRNA/pre-mRNA hybrid RNAs with similar affinities and association rate constants. Gold-labeling of editosome-bound RNA in combination with transmission electron microscopy (TEM) identified a single RNA binding site per editosome. However, atomic force microscopy (AFM) of individual pre-mRNA/editosome complexes revealed that multiple editosomes can interact with one pre-mRNA. Lastly, we demonstrate a so far unknown activity of the editing machinery: editosome-bound RNA becomes unfolded by a chaperone-type RNA unwinding activity.
	PMID: 22661715 [PubMed - as supplied by publisher]

5.	Med Microbiol Immunol. 2012 Jun 3. [Epub ahead of print] Infection of neutrophil granulocytes with Leishmania major activates ERK 1/2 and modulates multiple apoptotic pathways to inhibit apoptosis. Sarkar A, Aga E, Bussmeyer U, Bhattacharyya A, Möller S, Hellberg L, Behnen M, Solbach W, Laskay T. Source Institute for Medical Microbiology and Hygiene, University of Lübeck, Ratzeburger Allee 160, 23538, Lübeck, Germany. Abstract Neutrophil granulocytes provide the first line of defense against bacterial, fungal, and parasitic infections. They phagocytose and kill many invading pathogens. Certain pathogenic microorganisms such as the intracellular protozoan parasite Leishmania major (L. major) can survive inside neutrophils. Mature neutrophils have a very short life span due to spontaneous apoptosis. Previously, we have reported that infections with L. major are able to delay spontaneous apoptosis. In the present study, we addressed the underlying mechanisms of regulation of both extrinsic and intrinsic apoptosis. We show that interaction with L. major transiently activates ERK1/2 phosphorylation. Pharmacological inhibition of ERK1/2 phosphorylation reversed the apoptosis delay. Moreover, infection leads to the enhanced and sustainable expression of the anti-apoptotic proteins Bcl-2 and Bfl-1, respectively. As downstream events, the release of cytochrome c from mitochondria and processing of caspase-6 were inhibited. We also confirm that infection with L. major results in reduced FAS expression on the surface of neutrophils. The presented data indicate that infection with L. major affects both intrinsic as well as extrinsic pathways of neutrophil apoptosis. Enhanced life span of host neutrophils enables the parasite to survive within neutrophils.
	PMID: 22661217 [PubMed - as supplied by publisher]

6.	Glycoconj J. 2012 Jun 3. [Epub ahead of print] AuBr(3) mediated glycosidations: synthesis of tetrasaccharide motif of the Leishmania donovani lipophosphoglycan. Sureshkumar G, Hotha S. Source Department of Chemistry, Indian Insititute of Science Education & Research, Pune, 411 008, India. Abstract Tetrasaccharide cap present in lipophosphoglycan of the Leishmania donovani responsible for visceral Leishmaniaisis is synthesized as a fully protected propargyl glycoside. AuBr(3) mediated selective glycosylation of propargyl 1,2-orthoester in the presence of propargyl glycoside is employed as a key step to obtain propargyl containing oligomers. Further, propargyl tetrasaccharide is connected with a long chain hydrocarbon containing azidothiol functionality situated at two terminal ends via 'click' reaction.
	PMID: 22660966 [PubMed - as supplied by publisher]

7.	Exp Parasitol. 2012 May 29. [Epub ahead of print] Evaluation of the performance of selected in-house and commercially available PCR and real-time PCR assays for the detection of Leishmania DNA in canine clinical samples. Andreadou M, Liandris E, Kasampalidis IN, Taka S, Antoniou M, Ntais P, Vaiopoulou A, Theodoropoulos G, Gazouli M, Ikonomopoulos J. Source Agricultural University of Athens, Faculty of Animal Science and Aquaculture, Laboratory of Anatomy- Physiology, 75 Iera Odos st., 11855, Athens, Greece. Abstract Protozoa of the genus Leishmania are the causative agents of leishmaniosis. Although the polymerase chain reaction (PCR) has proved very effective in the detection of Leishmania DNA, a standardized method does not exist. In this study we attempt a comparative evaluation between one real time PCR (Method D), two in-house (Methods A and C), and a commercially available PCR assay (Method B) for the detection of Leishmania DNA, in order to support reliable diagnostic investigation of leishmaniosis. This evaluation was performed in regard to relative specificity and sensitivity, minimum detection limit (MDL), repeatability and reproducibility using cultured isolates and clinical samples. All the methods under study produced the expected result with the positive and negative controls. However with regard to clinical samples, Method C showed a statistically significant higher level of positivity. Relative sensitivity and specificity of Methods A, B and D in comparison to C was calculated respectively at 50.7%, 43%, 40%, and 90.8%, 93.4% and 89.5%. The MDL for Methods A-D was defined respectively at 30.7, 5, 3.7, and 5 promastigotes /ml. Repeatability and reproducibility were excellent in all cases with only the exception of Method A regarding reproducibility with a different brand of PCR reagents. The results that were recorded indicate that evaluation of PCR assays before their application for research and clinical diagnosis can provide useful evidence for their reliable application. Within this context the use of internal amplification controls and the confirmation of the specificity of the amplification product is recommended. Copyright © 2012. Published by Elsevier Inc.
	PMID: 22659229 [PubMed - as supplied by publisher]

8.	Trans R Soc Trop Med Hyg. 2012 May 30. [Epub ahead of print] Western blot analysis as an aid for the diagnosis of cutaneous leishmaniasis due to Leishmania major. Pomares C, Despierres L, Del Giudice P, Delaunay P, Michel G, Ferrua B, Marty P. Source Faculté de Médecine, Université de Nice-Sophia Antipolis, Service de Parasitologie-Mycologie, Centre Hospitalier Universitaire de Nice, Nice, France; Bâtiment Universitaire Archimed, INSERM U895, C3M, Equipe 6, 151 Route St Antoine de Ginestière, BP 23194, 06204 Nice Cedex 3, France. Abstract Cutaneous leishmaniasis (CL) due to Leishmania major is endemic in the Old World. To evaluate the diagnostic value of Western blot (WB) compared with IFAT, we tested serum samples from 45 patients with proven CL. Twenty-one (47%) patients were positive by IFAT and all patients were positive by WB with specific bands against 14kDa and/or 18kDa Leishmania antigens. Our results suggest that WB could be a useful non-invasive tool for the diagnosis of CL caused by L. major. Copyright © 2012 Royal Society of Tropical Medicine and Hygiene. Published by Elsevier Ltd. All rights reserved.
	PMID: 22657532 [PubMed - as supplied by publisher]

9.	Tidsskr Nor Laegeforen. 2012 Apr 17;132(7):804-5. [Exotic imported disease and scourge of the poor]. [Article in Norwegian] Bøhler E. Source Okhaldhunga Community Hospital, Nepal. bohler@wlink.com.np Free Article
	PMID: 22511091 [PubMed - indexed for MEDLINE]

10.	Med Chem. 2011 Nov;7(6):704-10. Synthesis and in vitro leishmanicidal activity of disulfide derivatives. Khan KM, Taha M, Naz F, Khan M, Rahim F, Samreen, Perveen S, Choudhary MI. Source H. E. J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Karachi-75270, Pakistan. khalid.khan@iccs.edu Abstract Disulfides 1-30 have been synthesized and their in vitro leishmanicidal activity has been evaluated. Compounds 18 (IC50 = 2.70 ± 0.044 μM), 19 (IC50 = 2.85 ± 0.02 μM), 20 (IC50 = 2.92 ± 0.01 μM), 26 (IC50 = 3.69 ± 0.01 μM), 21 (IC50 = 4.45 ± 0.029 μM), and 29 (IC50 = 4.46 ± 0.025 μM) showed a remarkable leishmanicidal activity if compared with standard pentamidine (IC50 = 5.09 ± 0.04 μM). This study has discovered a series of possible molecules as antileishmanial agents. A structure-activity relationship study has also been carried out. The structures of all the synthesized compounds were identified by using spectroscopic techniques, including 1H-NMR and EI MS.
	PMID: 22313310 [PubMed - indexed for MEDLINE]
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