What's new for 'Trypanosomatids' in PubMed

This message contains My NCBI what's new results from the National Center for Biotechnology Information (NCBI) at the U.S. National Library of Medicine (NLM).
Do not reply directly to this message.

Sender's message:

Sent on Tuesday, 2010 Aug 10
Search kinetoplastids OR kinetoplastid OR Kinetoplastida OR "trypanosoma brucei" OR leishmania OR brucei OR leishmaniasis OR "African trypanosomiasis"
Click here to view complete results in PubMed. (Results may change over time.)
To unsubscribe from these e-mail updates click here.

PubMed Results

Items 1 - 7 of 7

1.	Acta Crystallogr Sect F Struct Biol Cryst Commun. 2010 Aug 1;66(Pt 8):871-7. Epub 2010 Jul 27. Purification and crystallization of human Cu/Zn superoxide dismutase recombinantly produced in the protozoan Leishmania tarentolae. Gazdag EM, Cirstea IC, Breitling R, Lukes J, Blankenfeldt W, Alexandrov K. Department of Physical Biochemistry, Max-Planck-Institute for Molecular Physiology, Otto-Hahn-Strasse 11, 44227 Dortmund, Germany. Abstract The rapid and inexpensive production of high-quality eukaryotic proteins in recombinant form still remains a challenge in structural biology. Here, a protein-expression system based on the protozoan Leishmania tarentolae was used to produce human Cu/Zn superoxide dismutase (SOD1) in recombinant form. Sequential integration of the SOD1 expression cassettes was demonstrated to lead to a linear increase in expression levels to up to 30 mg per litre. Chromatographic purification resulted in 90% pure recombinant protein, with a final yield of 6.5 mg per litre of culture. The protein was crystallized and the structures of two new crystal forms were determined. These results demonstrate the suitability of the L. tarentolae expression system for structural research.
	PMID: 20693657 [PubMed - in process]

2.	Eukaryot Cell. 2010 Aug 6. [Epub ahead of print] The N-terminus of phosphodiesterase TbPDEB1 of Trypanosoma brucei contains the signal for integration into the flagellar skeleton. Luginbuehl E, Ryter D, Schranz-Zumkehr J, Oberholzer M, Kunz S, Seebeck T. Institute of Cell Biology, University of Bern, CH-3012 Bern, Switzerland; Department of Microbiology, Immunology and Molecular Genetics, UCLA, Los Angeles, CA 90095, USA. Abstract The precise subcellular localization of the components of the cAMP-signaling pathways is a crucial aspect of eukaryotic intracellular signaling. In the human pathogen Trypanosoma brucei, the strict control of cAMP levels by cAMP-specific phosphodiesterases is essential for parasite survival, both in cell culture and in the infected host. Among the five cyclic nucleotide phosphodiesterases identified in this organism, two closely related isoenzymes, TbPDEB1 (PDEB1) and TbPDEB2 (PDEB2) are predominantly responsible for the maintenance of cAMP levels. Despite their close sequence similarity, they are distinctly localized in the cell. PDEB1 is mostly located to the flagellum where it forms an integral part of the flagellar skeleton. PDEB2 is mainly located in the cell body, and only a minor part of the protein localizes to the flagellum. The current study using transfection of procyclic trypanosomes with green fluorescent reporters demonstrates that the N-termini of the two enzymes are essential for determining their final subcellular localization. The first 70 amino acids of PDEB1 are sufficient to specifically direct a GFP reporter to the flagellum and to lead to its detergent-resistant integration into the flagellar skeleton. In contrast, the analogous region of PDEB2 causes the GFP reporter to reside predominantly in the cell body. Mutagenesis of selected residues in the N-terminal region of PDEB2 demonstrated that single amino acid changes are sufficient to redirect the reporter from a cell body location to a stable integration into the flagellar skeleton.
	PMID: 20693305 [PubMed - as supplied by publisher]

3.	Bioorg Med Chem Lett. 2010 Aug 6. [Epub ahead of print] Allicin and derivates are cysteine protease inhibitors with antiparasitic activity. Waag T, Gelhaus C, Rath J, Stich A, Leippe M, Schirmeister T. Institute of Pharmacy and Food Chemistry, University of Würzburg, Am Hubland, 97074 Würzburg, Germany. Abstract Allicin and derivatives thereof inhibit the CAC1 cysteine proteases falcipain 2, rhodesain, cathepsin B and L in the low micromolar range. The structure-activity relationship revealed that only derivatives with primary carbon atom in vicinity to the thiosulfinate sulfur atom attacked by the active-site Cys residue are active against the target enzymes. Some compounds also show potent antiparasitic activity against Plasmodium falciparum and Trypanosoma brucei brucei. Copyright © 2010 Elsevier Ltd. All rights reserved.
	PMID: 20692829 [PubMed - as supplied by publisher]

4.	Exp Parasitol. 2010 Aug 5. [Epub ahead of print] Leishmaniaamazonensis: partial purification and study of the bioc hemical properties of the telomerase reverse transcriptase activity from promastigote-stage. Giardini MA, Fernández MF, Lira CB, Cano MI. Center for Neglected Diseases Drug Discovery, Institut Pasteur Korea, Seongnam-si, Gyeonggi-do, South Korea. Abstract Telomeres are protein-DNA complexes that protect chromosome ends from degradation and fusion. In Leishmania spp., telomeric DNA comprises a conserved TTAGGG repeat and is maintained by telomerase. Telomerase is a multisubunit enzymatic complex that ensures the complete DNA replication by adding new telomeric repeats to the G-rich strand. In this report we aimed to purify and study the biochemical properties of L. amazonensis telomerase. In a first trial we used affinity chromatography with antisense 2'-O-methyl oligonucleotide without success since the Leishmania telomerase, similarly to Trypanosoma cruzi enzyme, was not eluted by competition, but instead, it remained bound to the column. Partially purified L. amazonensis telomerase activity was achieved by fractionation of extracts on complementary ion exchange and heparin columns. Further purification of these fractions on a G-rich telomeric DNA affinity chromatography enriched for telomerase activity. The knowledge of telomerase characteristics in Leishmania could help to develop new strategies to overcome leishmaniasis. Copyright © 2010. Published by Elsevier Inc.
	PMID: 20692257 [PubMed - as supplied by publisher]

5.	Res Vet Sci. 2010 Aug 5. [Epub ahead of print] Validation of an ELISA meth od for the serological diagnosis of canine brucellosis due to Brucella canis. de Oliveira MZ, Vale V, Keid L, Freire SM, Meyer R, Portela RW, Barrouin-Melo SM. Laboratório de Infectologia Veterinária, Escola de Medicina Veterinária, Universidade Federal da Bahia, Av. Ademar de Barros 500, 40170-000 Salvador, Brazil. Abstract In the present study, the validation of an enzyme-linked immunosorbent assay (ELISA) for serodiagnosis of canine brucellosis is described. Two different antigenic extracts, obtained by heat or ultrasonic homogenization of microbial antigens from a wild isolate of Brucella canis bacteria, were compared by ELISA and Western blot (WB). A total of 145 canine sera were used to define sensitivity, specificity and accuracy of the ELISA as follows: (1) sera from 34 animals with natural B. canis infection, confirmed by blood culture and PCR, as well as 51 sera samples from healthy dogs with negative results by the agar-gel immunodiffusion (AGID) test for canine brucellosis, were used as the control panel for B. canis infection; and (2) to scrutinize the possibility of cross reactions with other common dog infections in the same geographical area in Brazil, 60 sera samples from dogs harboring known infections by Leptospira sp., Ehrlichia canis, canine distemper virus (CDV), Neospora caninum, Babesia canis and Leishmania chagasi (10 in each group) were included in the study. The ELISA using heat soluble bacterial extract (HE-antigen) as antigen showed the best values of sensitivity (91.18%), specificity (100%) and accuracy (96.47%). In the WB analyses, the HE-antigen showed no cross-reactivity with sera from dogs with different infections, while the B. canis sonicate had various protein bands identified by those sera. The performance of the ELISA standardized with the heat soluble B. canis antigen indicates that this assay can be used as a reliable and practical method to confirm infection by this microorganism, as well as a tool for seroepidemiological studies. Copyright © 2010 Elsevier Ltd. All rights reserved.
	PMID: 20692004 [PubMed - as supplied by publisher]

6.	Exp Parasitol. 2010 Aug 4. [Epub ahead of print] Morphological and physiological changes in Leishmania promastigotes induced by yangambin, a lignan obtained from Ocotea duckei. Monte Neto RL, Sousa LM, Dias CS, Barbosa Filho JM, Oliveira MR, Figueiredo RC. Laboratório de Tecnologia Farmacêutica, Universidade Federal da Paraíba, 58051-970, João Pessoa, Paraíba, Brazil. Abstract We have previously demonstrated that yangambin, a lignan obtained from Ocotea duckei Vattimo (Lauraceae), shows antileishmanial activity against promastigote forms of Leishmania chagasi and Leishmania amazonensis. The aim of this study was to determine the in vitro effects of yangambin against these parasites using electron and confocal microscopy. L. chagasi and L. amazonensis promastigotes were incubated respectively with 50 mug/mL and 65 mug/mL of pure yangambin and stained with acridine orange. Treated-parasites showed significant alterations in fluorescence emission pattern and cell morphology when compared with control cells, including the appearance of abnormal round-shaped cells, loss of cell motility, nuclear pyknosis, cytoplasm acidification and increased number of acidic vesicular organelles (AVOs), suggesting important physiological changes. Ultrastructural analysis of treated-promatigotes showed characteristics of cell death by apoptosis as well as by autophagy. The presence of parasites exhibiting multiples nuclei suggests that yangambin may also affect the microtubule dynamic in both Leishmania species. Taken together our results show that yangambin is a promissing agent against Leishmania. Copyright © 2010. Published by Elsevier Inc.
	PMID: 20691682 [PubMed - as supplied by publisher]

7.	Trop Med Int Health. 2010 Aug;15(8):881-9. Epub 2010 Jun 9. A geographical approach to identify sleeping sickness risk factors in a mangrove ecosystem. Courtin F, Jamonneau V, Camara M, Camara O, Coulibaly B, Diarra A, Solano P, Bucheton B. Institut de Recherche pour le Développement, UMR 177 IRD-CIRAD, Centre International de Recherche Développement sur l'Elevage en zone Subhumide, Bobo-Dioulasso, Burkina Faso. courtinfabrice@yahoo.fr Abstract OBJECTIVES: To provide a better understanding of sleeping sickness transmission and spread in mangrove areas to optimize its control. METHODS: In the Forecariah mangrove area, Guinea, 19 sleeping sickness cases and 19 matched controls were followed up in their living areas (at home, in fields and at water points). All occupational sites and pathways were mapped and then placed in their environmental context. RESULTS: The sleeping sickness cases displayed a significantly broader and more diverse spatial occupation than the controls. They covered double the daily walking distances of controls and had on average two more occupational sites, most of which were located in mangrove forests. Activities with a higher transmission risk (rice culture, attendance of pirogue jetties) were identified as well as high-risk areas and pathways. CONCLUSIONS: An entomological control strategy targeting transmission risk areas is proposed. Its implementation in a control programme would reduce by 86% the efforts needed for a classical vector control programme throughout the area. Medical surveys set up at specific locations, such as pirogue jetties and high-risk paths, should also enable better targeting of the population at highest risk.
	PMID: 20545924 [PubMed - indexed for MEDLINE]
	Related citations