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 - 9 of 9

1.	ChemMedChem. 2010 Dec 15. [Epub ahead of print] Synthesis and Evaluation of Indatraline-Based Inhibitors for Trypanothione Reductase. Walton JG, Jones DC, Kiuru P, Durie AJ, Westwood NJ, Fairlamb AH. School of Chemistry and Biomedical Sciences Research Complex, University of St Andrews, North Haugh, St Andrews, Fife, KY16 9ST (UK), Fax: (+44) 1334-462595. Abstract The search for novel compounds of relevance to the treatment of diseases caused by trypanosomatid protozoan parasites continues. Screening of a large library of known bioactive compounds has led to several drug-like starting points for further optimisation. In this study, novel analogues of the monoamine uptake inhibitor indatraline were prepared and assessed both as inhibitors of trypanothione reductase (TryR) and against the parasite Trypanosoma brucei. Although it proved difficult to significantly increase the potency of the original compound as an inhibitor of TryR, some insight into the preferred substituent on the amine group and in the two aromatic rings of the parent indatraline was deduced. In addition, detailed mode of action studies indicated that two of the inhibitors exhibit a mixed mode of inhibition.
	PMID: 21162087 [PubMed - as supplied by publisher]

2.	Int J Environ Health Res. 2010 Dec;20(6):415-30. Impact of socio-economic conditions on the incidence of visceral leishmaniasis in Bihar, India. Sheets D, Mubayi A, Kojouharov HV. Department of Economics, University of Texas at Arlington, Arlington, Texas, USA. Abstract Visceral leishmaniasis (VL) is one of the world's worst parasitic killers, second only to Malaria, claiming thousands of lives every year. More than three fifths of the world's VL cases occur in the Indian state of Bihar alone. While some research has been conducted with emphasis on the effects of climatic variables on the VL incidence rate, rigorous analysis of the effects of socio-economic variables is still lacking. In this paper a regression model is developed that describes the relationship between VL incidence rate and a variety of socio-economic factors. It uses data from 2005 and explains 92% of the observed variance. In addition, a stepwise regression model is also used to identify the most important factors that facilitate the prevalence of the VL disease. A discussion on how to most effectively distribute Bihar's limited resources on various control measures to decrease the incidence of VL is also presented.
	PMID: 21161803 [PubMed - in process]

3.	Parasitol Res. 2010 Dec 15. [Epub ahead of print] Leishmania sp. identification by PCR associated with sequencing of target SSU rDNA in paraffin-embedded skin samples stored for more than 30 years. de Lima AC, Zampieri RA, Tomokane TY, Laurenti MD, Silveira FT, Corbett CE, Floeter-Winter LM, Gomes CM. Pathology Department, Medical School of São Paulo University, São Paulo, Brazil, carolstocco@gmail.com. Abstract Paraffin-embedded samples commonly stored at educational and research institutions constitute tissues banks for follow-up or epidemiological studies; however, the paraffin inclusion process involves the use of substances that can cause DNA degradation. In this study, a PCR protocol was applied to identify Leishmania strains in 33 paraffin-embedded skin samples of patients with American cutaneous leishmaniasis. DNA was obtained by the phenol-chloroform protocol following paraffin removal and then used in PCR or nested PCR based on the nucleotide sequence of the small subunit ribosomal RNA (SSU rDNA). The amplicons obtained were cloned and sequenced to determine the single nucleotide polymorphism that distinguishes between different Leishmania species or groups. This assay allowed to distinguish organisms belonging to the subgenus Viannia and identify L. (Leishmania) amazonensis and L. (L.) chagasi of the Leishmania subgenus. Of the 33 samples, PCR and nested PCR identified 91% of samples. After sequencing the PCR product of 26 samples, 16 were identified as L. (L.) amazonensis, the other 10 contain organisms belonging to the L. (Viannia) sub-genus. These results open a huge opportunity to study stored samples and promote relevant contributions to epidemiological studies.
	PMID: 21161272 [PubMed - as supplied by publisher]

4.	J Mol Microbiol Biotechnol. 2010 Dec 14;19(4):213-223. [Epub ahead of print] The 6-Phosphogluconate Dehydrogenase of Leishmania (Leishmania) mexicana: Gene Characterization and Protein Structure Prediction. González D, Pérez JL, Serrano ML, Igoillo-Esteve M, Cazzulo JJ, Barrett MP, Bubis J, Mendoza-León A. Laboratorio de Bioquímica y Biología Molecular de Parásitos, Instituto de Biología Experimental (IBE), Facultad de Ciencias, Universidad Central de Venezuela, Caracas, Venezuela. Abstract 6-Phosphogluconate dehydrogenase (6PGDH) is a key enzyme of the oxidative branch involved in the generation of NADPH and ribulose 5-phosphate. In the present work, we describe the cloning, sequencing and characterization of a 6PGDH gene from Leishmania (Leishmania) mexicana. The gene encodes a polypeptide chain of 479 amino acid residues with a predicted molecular mass of 52 kDa and a pI of 5.77. The recombinant protein possesses a dimeric quaternary structure and displays kinetic parameter values intermediate between those reported for Trypanosoma brucei and T. cruzi with apparent K(m) values of 6.93 and 5.2 μM for 6PG and NADP(+), respectively. The three-dimensional structure of the enzymes of Leishmania and T. cruzi were modelled from their amino acid sequence using the crystal structure of the enzyme of T. brucei as template. The amino acid residues located in the 6PGDH C-terminal region, which are known to participate in the salt bridges maintaining the protein dimeric structure, differed significantly among the enzymes of Leishmania, T. cruzi, and T. brucei. Our results strongly suggest that 6PGDH can be selected as a potential target for the development of new therapeutic drugs in order to improve existing chemotherapeutic treatments against these parasites. Copyright © 2010 S. Karger AG, Basel.
	PMID: 21160204 [PubMed - as supplied by publisher]

5.	Clin Vaccine Immunol. 2010 Dec 15. [Epub ahead of print] Note: Persistence of Leishmania donovani antibodies in past Visceral Leishmaniasis cases in India. Gidwani K, Picado A, Ostyn B, Singh SP, Kumar R, Khanal B, Lejon V, Chappuis F, Boelaert M, Sundar S. Banaras Hindu University, Varanasi, India; Institute of Tropical Medicine, Antwerp, Belgium; B. P. Koirala Institute of Health Sciences, Dharan, Nepal; Geneva University Hospitals, Geneva, Switzerland. Abstract Anti-Leishmania donovani antibodies persistence in past Visceral Leishmaniasis (VL) cases was retrospectively assessed by means of Direct Agglutination Test (DAT) and rK39 ELISA. Antibody titres remained high for an extended period of time in past VL. These results highlight the need to carefully elicit the history of patients with VL symptoms.
	PMID: 21159922 [PubMed - as supplied by publisher]

6.	Cell Microbiol. 2010 Dec 16. doi: 10.1111/j.1462-5822.2010.01566.x. [Epub ahead of print] Molecular bases of cyto skeleton plasticity during the Trypanosoma brucei parasite cycle. Rotureau B, Subota I, Bastin P. Institut Pasteur, Trypanosome Cell Biology Unit, Paris, France CNRS, URA 2581, Paris, France. Abstract African trypanosomes are flagellated protozoan parasites responsible for sleeping sickness and transmitted by tsetse flies. The accomplishment of their parasite cycle requires adaptation to highly diverse environments. These transitions take place in a strictly defined order and are accompanied by spectacular morphological modifications in cell size, shape and positioning of organelles. To understand the molecular bases of these processes, parasites isolated from different tissues of the tsetse fly were analysed by immunofluorescence with markers for specific cytoskeleton components and by a new immunofluorescence-based assay for evaluation of the cell volume. The data revealed striking differences between proliferative stages found in the midgut or in the salivary glands and the differentiating stage occurring in the proventriculus. Cell proliferation was characterised by a significant increase in cell volume, by a pronounced cell elongation marked by microtubule extension at the posterior end, and by the production of a new flagellum similar to the existing one. In contrast, the differentiating stage found in the proventriculus does not display any increase in cell volume neither in cell length, but is marked by a profound remodelling of the posterior part of the cytoskeleton and by changes in molecular composition and / or organisation of the flagellum attachment zone. © 2010 Blackwell Publishing Ltd.
	PMID: 21159115 [PubMed - as supplied by publisher]

7.	J Parasitol. 2010 Dec;96(6):1230-1. Epub 2010 Aug 13. Survey of Antibodies to Trypanosoma cruzi and Leishmania spp. in Gray and Red Fox Populations From North Carolina and Virginia. Rosypal AC, Tripp S, Lewis S, Francis J, Stoskopf MK, Larsen RS, Lindsay DS. Department of Natural Sciences and Mathematics, College of Science, Technology, Engineering and Mathematics, Johnson C. Smith University, Charlotte, North Carolina, 28216. Abstract Abstract American trypanosomiasis and leishmaniasis are caused by related hemoflagellate parasites, Trypanosoma cruzi and Leishmania spp., which share several common host species. Both zoonotic protozoans are endemic in the United States. Canines, including domestic and wild canids, are reservoir hosts for human infections with T. cruzi and Leishmania spp. The present study examined the seroprevalence of T. cruzi and Leishmania spp. in wild canids from North Carolina and Virginia. Wild canine species tested in this work included 49 gray foxes ( Urocyon cinereoargenteus ) and 5 red foxes ( Vulpes vulpes ). Overall, sera samples from 54 foxes (North Carolina  =  43; Virginia  =  11) were tested by immunochromatographic strip assays (ICT). Antibodies to T. cruzi were found in 4 (9%) gray foxes from North Carolina and 2 (18%) gray foxes from Virginia. Antibodies to Leishmania spp. were detected in 1 (2%) gray fox from North Carolina. Our results indicate that wild canids are exposed more frequently to T. cruzi in North Carolina than Leishmania spp. and only T. cruzi in Virginia.
	PMID: 21158642 [PubMed - in process]

8.	J Parasitol. 2010 Dec;96(6):1134-8. Epub 2010 Aug 13. Population Changes in Leish mania chagasi Promastigote Developmental Stages Due to Serial Passage. Lei SM, Romine NM, Beetham JK. Departments of Veterinary Pathology and Entomology, Iowa State University, Ames, Iowa 50011 jbeetham@iastate.edu. Abstract Abstract Leishmania chagasi causes visceral leishmaniasis, a potentially fatal disease of humans. Within the sand fly vector, L. chagasi replicates as promastigotes which undergo complex changes in morphology as they progress from early stage procyclic promastigotes, to intermediate stage leptomonad and nectomonad promastigotes, and ultimately to terminal stage metacyclic promastigotes that are highly infective to vertebrates. This developmental progression is largely recapitulated in vitro using axenic promastigote cultures that have been passaged only a few times. Within a single passage (which takes about a week), axenic cultures progress from logarithmic to stationary growth phases; parasites within those growth phases progress from stages that do not have metacyclic cell properties to ones that do. Interestingly, repeated serial passage of promastigote cultures will result in cell populations that exhibit perturbations in developmental progression, in expression levels of surface macromolecules (major surface protease, MSP, and promastigote surface antigen, PSA), and in virulence properties, including resistance to serum lysis. Experiments were performed to determine whether there exists a direct relationship between promastigote developmental form and perturbations associated with repeated serial passage. Passage 2 to passage 4 L. chagasi cultures at stationary growth phase were predominately (>85%) comprised of metacyclic promastigotes and exhibited high resistance to serum lysis and high levels of MSP and PSA. Serial passaging 8, or more, times resulted in a stationary phase population that was largely (>85%) comprised of nectomonad promastigotes, almost completely devoid (<2%) of metacyclic promastigotes, and that exhibited low resistance to serum lysis and low levels of MSP and PSA. The study suggests that the loss of particular cell properties seen in cells from serially passaged cultures is principally due to a dramatic reduction in the proportion of metacyclic promastigotes. Additionally, the study suggests that serially passaged cultures may be a highly enriched source of nectomonad-stage promastigotes, a stage that has largely been characterized only in mixtures containing other promastigote forms.
	PMID: 21158623 [PubMed - in process]

9.	Indian J Exp Biol. 2010 Mar;48(3):314-7. Antileishmanial phenylpropanoids from Alpinia galanga (Linn.) Willd. Kaur A, Singh R, Dey CS, Sharma SS, Bhutani KK, Singh IP. Department of Natural Products, National Institute of Pharmaceutical Education and Research, Sector-67, S.A.S. Nagar, 160 062, India. Abstract Hexane, chloroform and ethyl acetate extracts (100 microg/ml) of Alpinia galanga rhizomes exhibited significant activity in vitro against promastigotes of L. donovani. Twelve compounds namely, methyleugenol (1), p-coumaryl diacetate (2), 1'-acetoxychavicol acetate (3), 1'-acetoxyeugenol acetate (4), trans-p-acetoxycinnamyl alcohol (5), trans-3,4-dimethoxycinnamyl alcohol (6), p-hydroxybenzaldehyde (7), p-hydroxycinnamaldehyde (8), trans-p-coumaryl alcohol (9), galangin (10), trans-p-coumaric acid (11) and galanganol B (12) were isolated from these extracts. Of these, compounds 2, 3, 4 and 5 were found most active in vitro against promastigotes of L. donovani with IC50 values of 39.3, 32.9, 18.9 and 79.9 microM respectively. This is the first report of antileishmanial activity of the extracts and isolated constituents of A. galanga.
	PMID: 21046987 [PubMed - indexed for MEDLINE]
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