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Sent on Tuesday, 2011 Aug 02Search kinetoplastids OR kinetoplastid OR Kinetoplastida OR "trypanosoma brucei" OR leishmania OR brucei OR leishmaniasis OR "African trypanosomiasis"
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| PubMed Results |
| 1. | J Pept Sci. 2011 Aug 1. doi: 10.1002/psc.1398. [Epub ahead of print]Studies on the antileishmanial properties of the antimicrobial peptides temporin A, B and 1Sa.Chadbourne FL, Raleigh C, Ali HZ, Denny PW, Cobb SL.SourceBiophysical Sciences Institute, Department of Chemistry and School of Biological and Biomedical Sciences, Durham University, South Road, Durham DH1 3LE, UK. AbstractGiven the paucity and toxicity of available drugs for leishmaniasis, coupled with the advent of drug resistance, the discovery of new therapies for this neglected tropical disease is recognised as being of the utmost urgency. As such antimicrobial peptides (AMPs) have been proposed as promising compounds against the causative Leishmania species, insect vector-borne protozoan parasites. Here the AMP temporins A, B and 1Sa have been synthesised and screened for activity against Leishmania mexicana insect stage promastigotes and mammalian stage amastigotes, a significant cause of human cutaneous disease. In contrast to previous studies with other species the activity of these AMPs against L. mexicana amastigotes was low. This suggests that amastigotes from different Leishmania species display varying susceptibility to peptides from the temporin family, perhaps indicating differences in their surface structure, the proposed target of these AMPs. In contrast, insect stage L. mexicana promastigotes were sensitive to two of the screened temporins which clearly demonstrates the importance of screening AMPs against both forms of the parasite.Copyright © 2011 European Peptide Society and John Wiley & Sons, Ltd. Copyright © 2011 European Peptide Society and John Wiley & Sons, Ltd. |
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| 2. | J Pept Sci. 2011 Aug 1. doi: 10.1002/psc.1392. [Epub ahead of print]Dermaseptin 01 as antimicrobial peptide with rich biotechnological potential: study of peptide interaction with membranes containing Leishmania amazonensis lipid-rich extract and membrane models.Salay LC, Nobre TM, Colhone MC, Zaniquelli ME, Ciancaglini P, Stabeli RG, Leite JR, Zucolotto V.SourceInstituto de FÃsica de São Carlos, IFSC, Universidade de São Paulo, USP, 13560-970 São Carlos, São Paulo, Brazil. lcsalay@yahoo.com.br. AbstractThis article addresses the interactions of the synthetic antimicrobial peptide dermaseptin 01 (GLWSTIKQKGKEAAIAAA- KAAGQAALGAL-NH(2) , DS 01) with phospholipid (PL) monolayers comprising (i) a lipid-rich extract of Leishmania amazonensis (LRE-La), (ii) zwitterionic PL (dipalmitoylphosphatidylcholine, DPPC), and (iii) negatively charged PL (dipalmitoylphosphatidylglycerol, DPPG). The degree of interaction of DS 01 with the different biomembrane models was quantified from equilibrium and dynamic liquid-air interface parameters. At low peptide concentrations, interactions between DS 01 and zwitterionic PL, as well as with the LRE-La monolayers were very weak, whereas with negatively charged PLs the interactions were stronger. For peptide concentrations above 1 µg/ml, a considerable expansion of negatively charged monolayers occurred. In the case of DPPC, it was possible to return to the original lipid area in the condensed phase, suggesting that the peptide was expelled from the monolayer. However, in the case of DPPG, the average area per lipid molecule in the presence of DS 01 was higher than pure PLs even at high surface pressures, suggesting that at least part of DS 01 remained incorporated in the monolayer. For the LRE-La monolayers, DS 01 also remained in the monolayer. This is the first report on the antiparasitic activity of AMPs using Langmuir monolayers of a natural lipid extract from L. amazonensis. Copyright © 2011 European Peptide Society and John Wiley & Sons, Ltd. Copyright © 2011 European Peptide Society and John Wiley & Sons, Ltd. |
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| 3. | Eur J Immunol. 2011 Aug 1. doi: 10.1002/eji.201041307. [Epub ahead of print]IL-10 limits production of pathogenic TNF by M1 myeloid cells through induction of nuclear NF-kB p50 member in Trypanosoma congolense infection resistant C57BL/6 mice.Bosschaerts T, Morias Y, Stijlemans B, Hérin M, Porta C, Sica A, Mantovani A, De Baetselier P, Beschin A.SourceDepartment of Molecular and Cellular Interactions, VIB, 1050 Brussels, Belgium; Laboratory of Cellular and Molecular Immunology, Vrije Universiteit Brussel, 1050, Brussels, Belgium. AbstractA balance between parasite elimination and control of infection-associated pathogenicity is crucial for resistance to African trypanosomiasis. By producing TNF and NO, CD11b(+) myeloid cells with a classical activation status (M1) contribute to parasitemia control in experimental Trypanosoma congolense infection in resistant C57BL/6 mice. However, in these mice, IL-10 is required to regulate M1-associated inflammation, avoiding tissue/liver damage and ensuring prolonged survival. In an effort to dissect the mechanisms behind the anti-inflammatory activity of IL-10 in T. congolense infected C57BL/6 mice, we show using antibody blocking IL-10 receptor that IL-10 impairs the accumulation and M1 activation in the liver of TNF/iNOS producing CD11b(+) Ly6C(+) cells. Using infected IL-10(flox/flox) LysM-Cre(+/+) mice, we show that myeloid cell-derived IL-10 limits M1 activation of CD11b(+) Ly6C(+) cells specifically at the level of TNF production. Moreover, higher production of TNF in infected IL-10(flox/flox) LysM-Cre(+/+) mice associated with reduced nuclear accumulation of the NF-kB p50 subunit in CD11b(+) M1 cells. Furthermore, in infected p50 mice, TNF production by CD11b(+) Ly6C(+) cells and liver injury increased. These data suggest that preferential nuclear accumulation of p50 represents an IL-10-dependent anti-inflammatory mechanism in M1-type CD11b(+) myeloid cells that regulates the production of pathogenic TNF during T. congolense infection in resistant C57BL/6 mice. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. |
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| 4. | Mol Cell Biochem. 2011 Jul 31. [Epub ahead of print]Knockdown of LdMC1 and Hsp70 by antisense oligonucleotides causes cell-cycle defects and programmed cell death in Leishmania donovani.Raina P, Kaur S.SourceParasitology Laboratory, Department of Zoology, Panjab University, Chandigarh, 160014, India. AbstractProgrammed cell death (PCD) has important implications in the biology of unicellular parasites, especially in devising control strategies against them. In this study, we examined the role of metacaspase LdMC1 and heat shock protein Hsp70 in Leishmania donovani through transient gene knockdown using antisense oligonucleotides (ASOs), during MG132-induced PCD. Proteasome inhibitor MG132 was used for inducing PCD in the in vitro culture of Leishmania donovani, which was confirmed by morphological and molecular markers. To assess the role of LdMC1 and Hsp70, ASOs with partially modified phosphorothioate backbone were designed against the protein-coding regions of these genes. Promastigotes and axenic ALFs were exposed to ASOs, and gene knockdown was confirmed using RT-PCR. Exposure to MG132 and ASOs led to morphological defects, DNA fragmentation, delay in progressing through the S-phase of cell-cycle and a decrease in the mitochondrial membrane potential. Antisense knockdown of both these genes, individually as well as together, caused phenotypic and molecular characteristics of PCD. Simultaneous knockdown of both LdMC1 and Hsp70 led to a severity in these defects. Parasites co-exposed to MG132 along with ASOs suffered the maximum damage. Together, these data suggest that LdMC1 and Hsp70 have an indispensable role in Leishmania cell-cycle and are, therefore, important for its survival. |
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| 5. | Fitoterapia. 2011 Jul 23. [Epub ahead of print]Formylated phloroglucinols from Eucalyptus loxophleba foliage.Sidana J, Singh S, Arora SK, Foley WJ, Singh IP.SourceDepartment of Natural Products, National Institute of Pharmaceutical Education and Research (NIPER), Sector-67, S.A.S. Nagar, Punjab-160062, India. AbstractTwo new naturally occurring formylated phloroglucinol compounds (FPCs), a dimer, loxophlebal B (10) and a cyclized FPC, loxophlebene (8) together with eight other formylated phloroglucinols (1-7 and 9) were isolated from the chloroform-methanol (8:2) extract of the leaves of Eucalyptus loxophleba ssp. lissophloia. The structures of new compounds were established by comprehensive spectral analysis and by comparison of their NMR data with those of related compounds in the literature. All the isolated compounds were evaluated for anti-leishmanial activity against promastigotes of Leishmania donovani. Copyright © 2011. Published by Elsevier B.V. |
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| 6. | Ann Trop Med Parasitol. 2011 Apr;105(3):267-71.Human visceral leishmaniasis: decrease in serum cholesterol as a function of splenic parasite load.Ghosh J, Lal CS, Pandey K, Das VN, Das P, Roychoudhury K, Roy S.SourceCouncil of Scientific and Industrial Research, 4 Raja S. C. Mullick Road, Kolkata - 700 032, India. |
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| 7. | Ann Trop Med Parasitol. 2011 Apr;105(3):261-5.Epidemiological aspects of the transmission of the parasites causing human African trypanosomiasis in Angola.Truc P, Grébaut P, Lando A, Makiadi Donzoau F, Penchenier L, Herder S, Geiger A, Vatunga G, Josenando T.SourceCampus International de Baillarguet, 34398 Montpellier Cedex 5, France. |
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| 8. | Ann Trop Med Parasitol. 2011 Apr;105(3):217-24.Post-earthquake outbreak of cutaneous leishmaniasis in a rural region of southern Iran.Fakoorziba MR, Baseri A, Eghbal F, Rezaee S, Azizi K, Moemenbellah-Fard MD.SourceShiraz University of Medical Sciences, P.O. Box 71645-111, Shiraz, Iran. AbstractHuman cutaneous leishmaniasis (CL) is of increasing public-health importance in Iran. On 10 July 2003, two mild earthquakes struck the rural town of Zarindasht in the southern Iranian province of Fars. The results of passive detection of CL cases in this town (in which patients with any skin lesions were evaluated) from April 2002 to April 2004 indicated that the earthquakes may have led to an outbreak of the disease; annual incidence increased from 58·6 detected cases/100,000 in the 12 months before the earthquakes to (an outbreak peak of) 864 detected cases/100,000 in the following 12 months. In addition, the incidence of detected CL in the town that was struck by the earthquakes in 2003 was significantly higher in the 12 months after the earthquakes than that recorded, over the same 12 months, for Fars province as a whole (P<0·05). Most (70%) of the cases detected in the town were aged ≤10 years, about half (50·4%) of the detected skin lesions were on the face, and most (89·7%) of the skin lesions were caused by Leishmania major. Incidence over the study period showed marked seasonality, with most (79·5%) of the detected cases occurring between November and February. In areas where the disease is endemic, CL may need to be considered among the health threats posed by natural disasters such as earthquakes, and increased surveillance for CL after future earthquakes may be justified. |
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| 9. | Ann Trop Med Parasitol. 2011 Apr;105(3):209-15.The PCR-based detection and identification of the parasites causing human cutaneous leishmaniasis in the Iranian city of Ahvaz.Ghasemian M, Maraghi S, Samarbafzadeh AR, Jelowdar A, Kalantari M.SourceJundi-Shapour University of Medical Sciences, Ahvaz, Iran. AbstractIn Iran, Leishmania major or L. tropica cause almost all of the human cutaneous leishmaniasis (CL). Unfortunately, the detection methods frequently used for CL (the microscopical examination of direct smears or the culture of biopsies) are not very sensitive and the Leishmania species causing each case of CL in Iran is usually only tentatively identified from extrinsic factors, such as the case's clinical manifestations and region of residence. Recently, however, a nested PCR that targets the parasites' kinetoplast DNA has been used in the city of Ahvaz (the capital of the province of Khouzestan, in south-western Iran) to confirm the microscopical diagnosis of CL and to identify the causative parasites, to species level. Smears from the lesions on 100 suspected cases of CL were fixed, stained with Wright's eosin-methylene blue, and checked for amastigotes under a light microscope. Scrapings from the same smears were then tested for leishmanial DNA, using a nested PCR that allows the DNA from L. tropica to be identified and distinguished from that of L. major. The 100 smears investigated were all found amastigote-positive by microscopy and PCR-positive for either L. major DNA (97 smears) or L. tropica DNA (three smears). The predominant species causing CL in Ahvaz is therefore L. major. |
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| 10. | BMC Biochem. 2011 Jul 30;12(1):39. [Epub ahead of print]Biochemical characterization of trans-sialidase TS1 variants from Trypanosoma congolense.Koliwer-Brandl H, Gbem TT, Waespy M, Reichert O, Mandel P, Drebitz E, Dietz F, Kelm S.AbstractABSTRACT: BACKGROUND:Animal African trypanosomiasis, sleeping sickness in humans and Nagana in cattle, is a resurgent disease in Africa caused by Trypanosoma parasites. Trans-sialidases expressed by trypanosomes play an important role in the infection cycle of insects and mammals. Whereas trans-sialidases of other trypanosomes like the American T. cruzi are well investigated, relatively little research has been done on these enzymes of T. congolense. RESULTS:Based on a partial sequence and an open reading frame in the WTSI database, DNA sequences encoding for eleven T. congolense trans-sialidase 1 variants with 96.3 % overall amino acid identity were amplified. Trans-sialidase 1 variants were expressed as recombinant proteins, isolated and assayed for trans-sialylation activity. The purified proteins produced alpha2,3-sialyllactose from lactose by desialylating fetuin, clearly demonstrating their trans-sialidase activity. Using an HPLC-based assay, substrate specificities and kinetic parameters of two variants were characterized in detail indicating differences in substrate specificities for lactose, fetuin and synthetic substrates. Both enzymes were able to sialylate asialofetuin to an extent, which was sufficient to reconstitute binding sites for Siglec-4. A mass spectrometric analysis of the sialylation pattern of glycopeptides from fetuin revealed clear but generally similar changes in the sialylation pattern of the N-glycans on fetuin catalyzed by the trans-sialidases investigated. CONCLUSIONS:The identification and characterization of a trans-sialidase gene family of the African parasite T. congolense has opened new perspectives for investigating the biological role of these enzymes in Nagana and sleeping sickness. Based on this study it will be interesting to address the expression pattern of these genes and their activities in the different stages of the parasite in its infection cycle. Furthermore, these trans-sialidases have the biotechnological potential to be used for enzymatic modification of sialylated glycoconjugates. |
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