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Sent on Tuesday, 2010 Oct 19Search kinetoplastids OR kinetoplastid OR Kinetoplastida OR "trypanosoma brucei" OR leishmania OR brucei OR leishmaniasis OR "African trypanosomiasis"
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| PubMed Results |
| 1. | FASEB J. 2010 Oct 15. [Epub ahead of print]Multiple levels of gene regulation mediate differentiation of the intracellular pathogen Leishmania.Lahav T, Sivam D, Volpin H, Ronen M, Tsigankov P, Green A, Holland N, Kuzyk M, Borchers C, Zilberstein D, Myler PJ.*Faculty of Biology, Technion-Israel Institute of Technology, Haifa, Israel; AbstractFor many years, mRNA abundance has been used as the surrogate measure of gene expression in biological systems. However, recent genome-scale analyses in both bacteria and eukaryotes have revealed that mRNA levels correlate with steady-state protein abundance for only 50\N70\% of genes, indicating that translation and post-translation processes also play important roles in determining gene expression. What is not yet clear is whether dynamic processes such as cell cycle progression, differentiation, or response to environmental changes change the relationship between mRNA and protein abundance. Here, we describe a systems approach to interrogate promastigote-to-amastigote differentiation in the obligatory intracellular parasitic protozoan Leishmania donovani. Our results indicate that regulation of mRNA levels plays a major role early in the differentiation process, while translation and post-translational regulation are more important in the latter part. In addition, it appears that the differentiation signal causes a transent global increase in the rate of protein synthesis, which is subsequently down-regulated by phosphorylation of |ga-subunit of translation initiation factor 2. Thus, Leishmania dynamically changes the relationship between mRNA and protein abundance as it adapts to new environmental circumstances. It is likely that similar mechanisms play a more important role than previously recognized in regulation of gene expression in other organisms. Lahav, T., Sivam, D., Volpin, H., Ronen, M., Tsigankov, P., Green, A., Holland, N., Kuzyk, M., Borchers, C., Zilberstein, D., Myler, P. J. Multiple levels of gene regulation mediate differentiation of the intracellular pathogen Leishmania. |
| PMID: 20952481 [PubMed - as supplied by publisher] | |
| 2. | Int J Infect Dis. 2010 Oct 15. [Epub ahead of print]Leishmaniasis, an emerging infection in travelers.Pavli A, Maltezou HC.Travel Medicine Office, Hellenic Center for Disease Control and Prevention, Athens, Greece. AbstractLeishmaniasis is a vector-borne protozoan infection with a wide clinical spectrum, which ranges from asymptomatic infection to fatal visceral leishmaniasis. A review of the recent literature indicates a sharp increase in imported leishmaniasis cases in developed, non-endemic countries over the last decade, in association with increasing international tourism, military operations, and the influx of immigrants from endemic countries. South America is the main area for the acquisition of cutaneous leishmaniasis, and adventure travelers on long-term trips in highly-endemic forested areas are at particular risk. Popular Mediterranean destinations are emerging as the main areas of acquisition of visceral leishmaniasis for European travelers. Leishmaniasis should be considered in patients presenting with a compatible clinical syndrome and a history of travel to an endemic area, even if this occurred several months or years ago. Appropriate counseling should be provided to adventure travelers, military personnel, researchers, and other groups of travelers likely to be exposed to sandflies in endemic areas. Copyright © 2010 International Society for Infectious Diseases. Published by Elsevier Ltd. All rights reserved. |
| PMID: 20952234 [PubMed - as supplied by publisher] | |
| 3. | J Ethnopharmacol. 2010 Oct 14. [Epub ahead of print]ANTIMICROBIAL AND CYTOTOXIC ACTIVITIES OF MEDICINAL PLANTS OF THE BRAZILIAN CERRADO; USING BRAZILIAN CACHAÇA AS EXTRACTOR LIQUID.de Toledo CE, Britta EA, Ceole LF, Silva ER, Mello JC, Filho BP, Nakamura CV, Ueda-Nakamura T.Programa de Pós-graduação em Ciências Farmacêuticas, Universidade Estadual de Maringá, Av. Colombo, 5790, Maringá, Brazil. AbstractEthnopharmacological Importance: Many species of plants in the Brazilian cerrado (savanna) are widely used in ethnomedicine. However, the safety and effectiveness of medicinal plants used in communities with little or no access to manufactured drugs should be evaluated. AIM OF THE STUDY: : Evaluate the antimicrobial and cytotoxic activities of extracts from eight plant species, obtained using Brazilian cachaça as the extractor liquid. MATERIALS AND METHODS: The extracts were tested against Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Candida albicans, Candida parapsilosis, promastigote forms of Leishmania amazonensis, and poliovirus. In addition, cytotoxic activity was assayed in Vero cells and in human erythrocytes. RESULTS: The plant species Curatella americana, Sclerolobium aureum, and Plathymenia reticulata showed the best activity against yeasts, especially the crude extract of C. americana and its ethyl-acetate fraction. Kielmeyera lathrophyton showed a minimum inhibitory concentration of 250μg/ml against S. aureus, and was inactive against Gram-negative bacteria. The extract obtained from Annona coriacea showed the best activity against the promastigote forms of Leishmania amazonensis (IC(50)= 175μg/ml). Only C. americana showed potential for antipoliovirus activity. The concentrations of the crude extracts that showed toxicity to VERO cells had CC(50) between 31 and 470μg/ml, and the lyophilized Brazilian cachaça showed a CC(50) of 307μg/ml. None of the extracts showed toxicity against human erythrocytes. CONCLUSIONS: Among the plant species studied, C. americana proved to be effective against microorganisms, especially as an antifungal. The results will help in the search for alternative drugs to be used in pharmacotherapy, and will contribute to establish safe and effective use of phytomedicines in the treatment of infectious diseases. Copyright © 2010. Published by Elsevier Ireland Ltd. |
| PMID: 20951786 [PubMed - as supplied by publisher] | |
| 4. | J Parasitol. 2010 Oct;96(5):929-36. Epub 2010 Apr 17.Vaccination with Recombinant Leishmania donovani Gamma-Glutamylcysteine Synthetase Fusion Protein Protects Against L. donovani Infection.Henriquez FL, Campbell SA, Roberts CW, Mullen AB, Burchmore R, Carter KC.School of Science, University of the West of Scotland, Paisley, U.K k.carter@strath.ac.uk. AbstractAbstract Visceral leishmaniasis presents a serious health threat in many parts of the world. There is, therefore, an urgent need for an approved vaccine for clinical use to protect against infection. In this study, the ability of recombinant Leishmania donovani gamma-glutamyl cysteine synthetase protein (LdγGCS) alone or incorporated into a non-ionic surfactant vesicle (NIV) delivery system to protect against L. donovani infection was evaluated in a BALB/c mouse model. Immunization with LdγGCS alone or LdγGCS-NIV induced specific IgG1 and IgG2a antibodies compared to controls, with LdγGCS-NIV inducing significantly higher titers of both antibody classes (P < 0.05). Both formulations induced similar increases in splenocyte IFN-γ production following ex vivo antigen stimulation with LdγGCS compared with cells from control mice (P < 0.05). Similar levels of protection against infection were induced by LdγGCS alone and LdγGCS-NIV, based on their ability to suppress liver parasite burdens compared to control values (P < 0.01), indicating that using a carrier system did not enhance the protective responses induced by the recombinant protein. The results of this study indicate that LdγGCS may be a useful component in a vaccine against L. donovani . |
| PMID: 20950100 [PubMed - in process] | |
| 5. | Nat Prod Commun. 2010 Aug;5(8):1161-6.Phytochemical investigation of Verbesina turbacensis Kunth: trypanosome cysteine protease inhibition by (-)-bornyl esters.Ogungbe IV, Crouch RA, Haber WA, Setzer WN.Department of Chemistry, University of Alabama in Huntsville, Huntsville, Alabama 35899, USA. AbstractThe bark and leaf essential oils of Verbesina turbacensis were obtained by hydrodistillation and analyzed by GC-MS. The bark oil of the plant was composed mainly of monoterpene hydrocarbons (83.5-90.4%), predominately alpha-pinene, while the leaf oil was composed mainly of sesquiterpene hydrocarbons, dominated by germacrene-D (29.1-36.9%), and delta-elemene (21.7-22.1%). Three bornyl hydroxycinnamic esters isolated from the acetone bark extract were found to inhibit the cysteine protease, rhodesain. Molecular docking analysis to probe the inhibitory interactions of the esters was also carried out. |
| PMID: 20839609 [PubMed - indexed for MEDLINE] | |
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| 6. | Biochim Biophys Acta. 2010 Sep;1804(9):1917-24. Epub 2010 Jun 9.Heterologous expression and purification of a biologically active legume lectin from Cratylia mollis seeds (CRAMOLL 1).Varejão N, Almeida Mda S, De Cicco NN, Atella GC, Coelho LC, Correia MA, Foguel D.Instituto de Bioquímica Médica, Programa de Biologia Estrutural, Centro Nacional de Ressonância Magnética Nuclear de Macromoléculas, Universidade Federal do Rio de Janeiro, Av. Bauhínia, 400, 21941-590, Rio de Janeiro, RJ, Brazil. AbstractCRAMOLL 1 is a mannose/glucose isolectin isolated from Cratylia mollis seeds. This lectin has 82% sequence identity with Con A and essentially the same quaternary structure. As with Con A, CRAMOLL 1 seems to undergo complex post-translational processing which makes it difficult to the use of traditional molecular cloning for heterologous expression. Here we report the expression and purification of functional recombinant CRAMOLL 1 (rCRAMOLL 1) in Escherichia coli. This was accomplished by introducing a chemically synthesized DNA encoding the mature CRAMOLL 1 amino acid sequence into a bacterial expression vector under T7 promoter control. Most of the recombinant lectin was found in insoluble aggregates (inclusion bodies), but we were able to recover reasonable amounts of soluble lectin in the active form by decreasing the protein induction temperature. The recombinant lectin was purified to homogeneity with one-step affinity chromatography. The plant CRAMOLL 1 (pCRAMOLL 1) and rCRAMOLL 1 share several physicochemical properties such as molecular mass, charge density and secondary and tertiary structures. However, pCRAMOLL 1 has a lower thermodynamic stability than rCRAMOLL 1 when probed by acidification, high temperature or high hydrostatic pressure, and this is probably caused by the presence of tetramers composed of fragmented monomers, which are formed in the plant cotyledon but absent from the recombinant protein. rCRAMOLL 1 behaves identically to its plant counterpart with respect to its specificity for monosaccharides, and to its agglutinating activities against rabbit erythrocytes and Trypanosoma cruzi epimastigote cells. Copyright © 2010 Elsevier B.V. All rights reserved. |
| PMID: 20538076 [PubMed - indexed for MEDLINE] | |
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