Tuesday, July 7, 2009

What's new for 'Trypanosomatids' in PubMed

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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: Mol Divers. 2009 Jul 4. [Epub ahead of print]

QSAR for RNases and theoretic-experimental study of molecular diversity on peptide mass fingerprints of a new Leishmania infantum protein.

González-Díaz H, Dea-Ayuela MA, Pérez-Montoto LG, Prado-Prado FJ, Agüero-Chapín G, Bolas-Fernández F, Vazquez-Padrón RI, Ubeira FM.

Department of Microbiology and Parasitology, and Department of Organic Chemistry, Faculty of Pharmacy, USC, 15782, Santiago de Compostela, Spain, gonzalezdiazh@yahoo.es.

The toxicity and low success of current treatments for Leishmaniosis determines the search of new peptide drugs and/or molecular targets in Leishmania pathogen species (L. infantum and L. major). For example, Ribonucleases (RNases) are enzymes relevant to several biologic processes; then, theoretical and experimental study of the molecular diversity of Peptide Mass Fingerprints (PMFs) of RNases is useful for drug design. This study introduces a methodology that combines QSAR models, 2D-Electrophoresis (2D-E), MALDI-TOF Mass Spectroscopy (MS), BLAST alignment, and Molecular Dynamics (MD) to explore PMFs of RNases. We illustrate this approach by investigating for the first time the PMFs of a new protein of L. infantum. Here we report and compare new versus old predictive models for RNases based on Topological Indices (TIs) of Markov Pseudo-Folding Lattices. These group of indices called Pseudo-folding Lattice 2D-TIs include: Spectral moments pi ( k )(x,y), Mean Electrostatic potentials xi ( k )(x,y), and Entropy measures theta ( k )(x,y). The accuracy of the models (training/cross-validation) was as follows: xi ( k )(x,y)-model (96.0%/91.7%)>pi ( k )(x,y)-model (84.7/83.3) > theta ( k )(x,y)-model (66.0/66.7). We also carried out a 2D-E analysis of biological samples of L. infantum promastigotes focusing on a 2D-E gel spot of one unknown protein with M<20, 100 and pI <7. MASCOT search identified 20 proteins with Mowse score >30, but not one >52 (threshold value), the higher value of 42 was for a probable DNA-directed RNA polymerase. However, we determined experimentally the sequence of more than 140 peptides. We used QSAR models to predict RNase scores for these peptides and BLAST alignment to confirm some results. We also calculated 3D-folding TIs based on MD experiments and compared 2D versus 3D-TIs on molecular phylogenetic analysis of the molecular diversity of these peptides. This combined strategy may be of interest in drug development or target identification.

PMID: 19578942 [PubMed - as supplied by publisher]

2: Braz J Infect Dis. 2009 Feb;13(1):47-52.

Comparison of serological and parasitological methods for cutaneous leishmaniasis diagnosis in the state of Paraná, Brazil.

Szargiki R, Castro EA, Luz E, Kowalthuk W, Machado AM, Thomaz-Soccol V.

Centro de Produção e Pesquisa de Imunobiológicos, SESA, Paraná

We evaluated the effectiveness of serological and parasitological methods for cutaneous leishmaniasis (CL) diagnosis in patients from the central region of Paraná state, southern Brazil. Five groups were compared: clinical diagnosis, parasitological diagnosis, communicants, inhabitants of a non-endemic area and carriers of other etiologies. Two antigens were prepared from promastigotes of Leishmania (Viannia) braziliensis and Leishmania (Leishmania) amazonensis for indirect immunofluorescence assay, ELISA and immunoblotting. The parasitological approaches detected 79.3% of the patients with a clinical diagnosis; the parasites were identified by PCR as L. (V.) braziliensis. Serological methods showed 95% sensitivity for homologous antigens. Immunoblotting revealed specific proteins for diagnosis of CL and detected 96.6% of the patients when L. (V.) braziliensis was used as an antigen, and 83.3% with L. (L.) amazonensis. This study demonstrated the importance of differential diagnosis for leishmaniasis; the association of two or more indirect methods increased diagnosis sensitivity.

PMID: 19578630 [PubMed - in process]

3: Braz J Infect Dis. 2009 Feb;13(1):44-6.

Increased levels of IL-10, IL-12, and IFN- in patients with visceral leishmaniasis.

Khoshdel A, Alborzi A, Rosouli M, Taheri E, Kiany S, Javadian MH.

Shahrekord University of Medical Sciences, Shahrekord.

Visceral leishmaniasis remains a serious public health problem in developing countries. Cytokines have a crucial role in the pathogenesis of this disease. We evaluated plasma levels of IL-10, IL-12 and IFN- in 32 patients with active visceral lieshmaniasis, in 29 siblings of the patients and in 23 normal individuals in an endemic area to look for correlations between the clinical outcome of infection and the plasma cytokine levels. An analysis was made with a skin test and a quantitative sandwich enzyme immunoassay. Data were analyzed with the Mann Whitney test and the Kruskal Wallis test. The cytokine levels were significantly higher in the patients than in the control groups. We concluded that normalization of the plasma level of IFN- can serve as a reliable parameter for considering the patient as cured.

PMID: 19578629 [PubMed - in process]

4: Cad Saude Publica. 2009 Jul;25(7):1642-6.

Dissemination of information on visceral leishmaniasis from schoolchildren to their families: a sustainable model for controlling the disease.

de Magalhães DF, da Silva JA, Haddad JP, Moreira EC, Fonseca MI, de Ornelas ML, Borges BK, da Luz ZM.

Escola de Veterinária, Universidade Federal de Minas Gerais, Belo Horizonte, Brasil.

A model for the dissemination of information on visceral leishmaniasis from schoolchildren to their families was evaluated in two schools in Caeté, Minas Gerais State, Brazil. Age ranged from 9 to 17 years in the two schools, one receiving the intervention (with 92 students) and the other serving as the control (96 students). All the students attended a class and received a pamphlet on visceral leishmaniasis. The intervention consisted of a homework assignment in which the student discussed the class content and pamphlet with a family member. Knowledge by family members (n = 100) on visceral leishmaniasis was evaluated with a pre and post-intervention questionnaire applied by a health agent, who also completed a form on hygiene around the household as observed during the home visit. A significant improvement was observed in knowledge and hygiene (e.g., sweeping of leaves, fruit, and branches from the yards) among the families that were exposed to the intervention (p < 0.05). The spread of information on visceral leishmaniasis by schoolchildren can contribute to measures for preventing the disease.

PMID: 19578588 [PubMed - in process]

5: Cad Saude Publica. 2009 Jul;25(7):1543-51.

Factors associated with the incidence of urban visceral leishmaniasis: an ecological study in Teresina, Piauí State, Brazil.

Cerbino Neto J, Werneck GL, Costa CH.

Instituto de Pesquisa Clínica Evandro Chagas, Fundação Oswaldo Cruz, Rio de Janeiro, Brasil.

The objective of this study was to identify socioeconomic and environmental factors associated with the incidence of visceral leishmaniasis in the city of Teresina, Piauí State, Brazil. This was an ecological study based on 1,744 cases reported from 1991 to 2000, and the city's neighborhoods served as the unit of analysis. Mean annual incidence rates were related to socioeconomic and demographic indicators and a vegetation index derived from remote sensing images by means of spatial multiple linear regression models. The neighborhoods with the highest incidence rates were mostly located in the city's peripheral areas. Multivariate analysis identified an interaction between population growth and the vegetation index, so that areas with high population growth and abundant vegetation showed the highest incidence rates. The percentage of households with piped water was inversely associated with visceral leishmaniasis incidence. Spatial distribution of visceral leishmaniasis in Teresina during the 1990s was heterogeneous, and incidence of the disease was associated with the peripheral neighborhoods with the heaviest vegetation cover, subject to rapid occupation and lack of adequate sanitation infrastructure.

PMID: 19578575 [PubMed - in process]

6: Phytomedicine. 2009 Jul 2. [Epub ahead of print]

Activity of (-)alpha-bisabolol against Leishmania infantum promastigotes.

Morales-Yuste M, Morillas-Márquez F, Martín-Sánchez J, Valero-López A, Navarro-Moll MC.

Facultad de Farmacia, Departamento de Parasitología, Universidad de Granada, Granada, Spain.

Many of the drugs used to treat leishmaniasis are associated with numerous adverse effects. Agents of natural origin have shown activity against different parasites. With this background, an in vitro study was conducted on the activity of (-)alpha-bisabolol, the principal component of Chamomilla recutita essential oil, against Leishmania infantum promastigotes, the main species responsible for human leishmaniasis in Spain. At the two highest concentrations tested (1000 and 500mug/ml), (-)alpha-bisabolol and pentamidine (control agent) achieved 100% inhibition of L. infantum promastigote. These in vitro data can be considered promising in support of the therapeutic use of (-)alpha-bisabolol preparations to treat leishmaniasis caused by L. infantum species.

PMID: 19577452 [PubMed - as supplied by publisher]

7: Immunobiology. 2009 Jul 2. [Epub ahead of print]

Understanding the role of monocytic cells in liver inflammation using parasite infection as a model.

Bosschaerts T, Guilliams M, Stijlemans B, De Baetselier P, Beschin A.

Department of Molecular and Cellular Interactions, VIB, 1050 Brussel, Belgium; Laboratory of Cellular and Molecular Immunology, Vrije Universiteit Brussel, 1050 Brussels, Belgium.

Uncontrolled inflammation is a major cause of pathogenicity during chronic parasite infections. Novel therapies should therefore aim at re-establishing the balance between pro- and anti-inflammatory signals during disease to avoid tissue damage and ensure survival of the host. In this context, we are intending to identify strategies capable of inducing counter-inflammatory activity in injured liver and thereby increasing the resistance of the host to African trypanosomiasis as a model for parasite infection. Here, recent evidence is summarized revealing how monocytic cells recruited to the liver of African trypanosome-infected mice develop an M1 or M2 activation status, thereby maintaining the capacity of the host to control parasite growth while avoiding the development of liver damage, which otherwise culminates in early death of the host.

PMID: 19577324 [PubMed - as supplied by publisher]

8: Annu Rev Microbiol. 2009 Jun 10. [Epub ahead of print]

The Trypanosoma brucei Flagellum: Moving Parasites in New Directions.

Ralston KS, Kabututu ZP, Melehani JH, Oberholzer M, Hill KL.

Department of Microbiology, Immunology, and Molecular Genetics, and Molecular Biology Institute, University of California, Los Angeles, California 90095.

African trypanosomes are devastating human and animal pathogens. Trypanosoma brucei rhodesiense and T. b. gambiense subspecies cause the fatal human disease known as African sleeping sickness. Approximately 500,000 new infections occur annually and the disease is fatal if untreated. T. brucei is transmitted by the tsetse fly and alternates between bloodstream-form and insect-form life cycle stages that are adapted to survive in the mammalian host and the insect vector, respectively. The importance of the flagellum for parasite motility and attachment to the tsetse fly salivary gland epithelium has been appreciated for many years. Recent studies have revealed both conserved and novel features of T. brucei flagellum structure and composition, as well as surprising new functions that are outlined here. These discoveries are important from the standpoint of understanding trypanosome biology and identifying novel drug targets, as well as for advancing our understanding of fundamental aspects of eukaryotic flagellum structure and function. Expected final online publication date for the Annual Review of Microbiology Volume 63 is September 08, 2009. Please see http://www.annualreviews.org/catalog/pubdates.aspx for revised estimates.

PMID: 19575562 [PubMed - as supplied by publisher]

9: Indian J Med Res. 2009 Mar;129(3):327-228.Click here to read LinkOut

Sample survey for indigenous cases of kala-azar in Assam by rk39 dipstick test.

Khan AM, Pandey K, Kumar V, Dutta P, Das P, Mahanta J.

PMID: 19491428 [PubMed - indexed for MEDLINE]

10: Exp Parasitol. 2009 Aug;122(4):328-37. Epub 2009 Apr 21.Click here to read Nucleotide, Taxonomy via GenBank, Protein, PopSet, LinkOut

Trypanosoma cruzi: new insights on ecophylogeny and hybridization by multigene sequencing of three nuclear and one maxicircle genes.

Subileau M, Barnabé C, Douzery EJ, Diosque P, Tibayrenc M.

UMR 1083 Sciences pour l'Oenologie, équipe Microbiologie et Technologie des Fermentations, ENSAM/INRA, 2 place Viala, 34060 Montpellier Cedex 01, France.

Natural populations of Trypanosoma cruzi are structured into five genetic lineages, T. cruzi I and T. cruzi II a to e, as the result of clonal evolution with rare genetic recombination events. To explore more in depth these phenomenons, a multigene sequencing approach was used, for the first time in the case of T. cruzi. Three nuclear loci and a maxicircle locus were sequenced on 18 T. cruzi stocks. Sequences were used to build phylogenetic trees from each locus and from concatenated sequences of all loci. The data confirmed the hybrid origin of DTUs IId and IIe, as the result of an ancient genetic recombination between strains pertaining to IIb and IIc. The data confirmed also a hybrid origin of DTUs IIa and IIc. Contrary to previous reports, we failed to detect mosaic genes. The phylogenetic relationship between DTUs and the respective roles of recombination and selection were tested.

PMID: 19389398 [PubMed - indexed for MEDLINE]

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