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Sent on Friday, 2011 Sep 09Search kinetoplastids OR kinetoplastid OR Kinetoplastida OR "trypanosoma brucei" OR leishmania OR brucei OR leishmaniasis OR "African trypanosomiasis"
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| PubMed Results |
| 1. | Eur J Clin Microbiol Infect Dis. 2011 Sep 7. [Epub ahead of print]Human African trypanosomiasis in endemic populations and travellers.Blum JA, Neumayr AL, Hatz CF.SourceMedical Department, Swiss Tropical and Public Health Institute, Socinstrasse 57, 4002, Basel, Switzerland, johannes.blum@unibas.ch. AbstractHuman African trypanosomiasis (HAT) or sleeping sickness is caused by the protozoan parasites Trypanosoma brucei (T.b.) gambiense (West African form) and T.b. rhodesiense (East African form) that are transmitted by the bite of the tsetse fly, Glossina spp.. Whereas most patients in endemic populations are infected with T.b. gambiense, most tourists are infected with T.b. rhodesiense. In endemic populations, T.b. gambiense HAT is characterized by chronic and intermittent fever, headache, pruritus, and lymphadenopathy in the first stage and by sleep disturbances and neuro-psychiatric disorders in the second stage. Recent descriptions of the clinical presentation of T.b. rhodesiense in endemic populations show a high variability in different foci. The symptomatology of travellers is markedly different from the usual textbook descriptions of African HAT patients. The onset of both infections is almost invariably an acute and febrile disease. Diagnosis and treatment are difficult and rely mostly on old methods and drugs. However, new molecular diagnostic technologies are under development. A promising new drug combination is currently evaluated in a phase 3 b study and further new drugs are under evaluation. |
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| 2. | J Biol Chem. 2011 Sep 7. [Epub ahead of print]Chemical structure of Trichomonas vaginalis surface lipoglycan: a role for short galactose ({beta}1-4/3) N-acetylglucosamine repeats in host cell interaction.Ryan CM, Mehlert A, Richardson JM, Ferguson MA, Johnson PJ.SourceUCLA, United States; AbstractThe extracellular parasite Trichomonas vaginalis contains a surface glycoconjugate that appears to mediate parasite:host cell interaction via binding to human galectin1. This glycoconjugate also elicits cytokine production from human vaginal epithelial cells, implicating its role in modulation of host immune responses. We have analyzed the structure of this glycoconjugate, previously described to contain the sugars rhamnose (Rha), N-acetylglucosamine (GlcNAc), galactose (Gal), xylose (Xyl), N-acetylgalactosamine (GalNAc) and glucose (Glc), using gas chromatograph mass spectrometry (GC/MS), matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI/TOF), electrospray MS/MS, nuclear magnetic resonance (NMR), combined with chemical and enzymatic digestions. Our data reveal a complex structure, named T. vaginalis lipoglycan (TvLG), that differs markedly from Leishmania LPG and Entamoeba lipopeptidophosphoglycan (LPPG) and is devoid of phosphosaccharide repeats. TvLG is composed of an α1/3 linked polyrhamnose core, where Rha residues are substituted at the 2 position with either β-Xyl or chains of, on average, five N-acetyllactosamine (3Galβ1/4GlcNAcβ1), LacNAc, units and occasionally lacto/N/biose (3Galβ1/3GlcNAcβ1), LNB. These chains are themselves periodically substituted at the Gal residues with Xyl/Rha. These structural analyses led us to test the role of the poly LacNAc/LNB chains in parasite binding to host cells. We found that reduction of poly LacNAc/LNB chains decreased the ability of TvLG to compete parasite binding to host cells. In summary, our data provide a new model for the structure of TvLG, composed of a polyrhamnose backbone with branches of Xyl and poly-LacNAc/LNB. Furthermore, the poly-LacNAc side chains are shown to be involved in parasite: host cell interaction. |
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| 3. | Vet Parasitol. 2011 Aug 19. [Epub ahead of print]Apoptosis in T lymphocytes from spleen tissue and peripheral blood of L. (L.) chagasi naturally infected dogs.Lima VM, Fattori KR, de Souza F, Eugênio FR, Santos PS, Rozza DB, Machado GF.SourceDepartamento de Clinica, Cirurgia e Reprodução Animal, Faculdade de Medicina Veterinária, Universidade Estadual Paulista, Rua Clóvis Pestana, 793, ZIP 16050-400 Araçatuba, São Paulo, Brazil(1). AbstractDogs are the main domestic reservoirs of L. (L.) chagasi. Once in the vertebrate host, the parasite may cause visceral leishmaniasis, which can also be transmitted to humans. Infected symptomatic dogs show disorganization in the white pulp in spleen tissue and a reduction in T lymphocytes in peripheral blood. To investigate whether apoptosis is involved in white pulp disorganization and diminished T cell counts in peripheral blood, apoptotic T cells from the spleen and peripheral blood of dogs naturally infected with L. (L.) chagasi and presenting clinical manifestations were quantified and compared with healthy dogs. Thirteen symptomatic adult dogs infected by L. (L.) chagasi and six healthy dogs from a nonendemic area (controls) were included in the study. Samples from spleen and peripheral blood were used to quantify apoptosis in CD3 lymphocytes by flow cytometry using Anexin V and Multicaspase kits; the results were compared using the Mann Whitney test. The percentage of total T cells was lower in Leishmania infected dogs compared to healthy controls (P<0.05). Apoptosis levels in T cells from PBMC and spleen were higher in infected dogs than in controls (P<0.05). The least squares method test was used to determine the effect between the degree of structural organization of spleen white pulp and the percentage of apoptosis in the spleen. A significant effect on the level of white pulp morphological disorganization and percentage of apoptosis in spleen T cells was observed (F=20.45; P=0.0014). These data suggest that apoptosis is an important for the immunopathogenesis of canine visceral leishmaniasis. Copyright © 2011 Elsevier B.V. All rights reserved. |
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| 4. | J Pharm Pharmacol. 2011 Oct;63(10):1346-57. doi: 10.1111/j.2042-7158.2011.01336.x. Epub 2011 Aug 19.Flavonoids in Scutellaria i mmaculata and S. ramosissima (Lamiaceae) and their biological activity.Mamadalieva NZ, Herrmann F, El-Readi MZ, Tahrani A, Hamoud R, Egamberdieva DR, Azimova SS, Wink M.SourceInstitute of the Chemistry of Plant Substances AS RUz, Tashkent, Uzbekistan Institute of Pharmacy and Molecular Biotechnology, Heidelberg University, Germany Biochemistry department, Faculty of Pharmacy, Al-Azhar University, Assiut, Egypt Department of Biotechnology and Microbiology, National University, Tashkent, Uzbekistan. AbstractObjectives The aim of this study was to investigate the flavonoid composition of Scutellaria immaculata and S. ramosissima (Lamiaceae) and the in-vitro biological activity of their extracts and flavonoids. Methods The flavonoid composition of S. immaculata (Si) and S. ramosissima (Sr) were analysed using LC-MS. Antimicrobial activity was studied in vitro against a range of bacteria and fungi using diffusion and microdilution methods. Anti-trypanosomal and cell proliferation inhibitory activity of the extracts and flavonoids was assessed using MTT. The antioxidant activity of the flavonoids and extracts were evaluated using DPPH* test. Key findings LC-MS investigation of Si and Sr plants allowed the identification, for the first time, of an additional 9 and 16 flavonoids, respectively. The methanol, chloroform and water extracts from these plants and six flavonoids (scutellarin, chrysin, apigenin, apigenin-7-O-glucoside, cynaroside and pinocembrine) exhibited significant inhibition of cell growth against HeLa, HepG-2 and MCF-7 cells. The chloroform extract of Sr showed potent cytotoxic effects with IC50 (drug concentration which resulted in a 50% reduction in cell viability) values of 9.25 ± 1.07 µg/ml, 12.83 ± 1.49 µg/ml and 17.29 ± 1.27 µg/ml, respectively. The highest anti-trypanosomal effect against T. b. brucei was shown by the chloroform extract of Sr with an IC50 (drug concentration which resulted in a 50% inhibition of the biological activity) of 61 µg/ml. The pure flavonoids showed an IC50 range between 3 and 29 µm, with cynaroside as the most active compound with an IC50 value of 3.961 ± 0.133 µm. The chloroform extract of Sr has potent antimicrobial activity against Streptococcus pyogenes (minimum inhibitory concentration, MIC = 0.03 mg/ml). Pinocembrine exhibited a strong activity against the all bacteria except Escherichia coli and yeasts. Water extracts of Sr and Si exhibited potent antioxidant activity with IC50 values of 5.62 ± 0.51 µg/ml and 3.48 ± 0.02 µg/ml, respectively. Scutellarin exerted stronger antioxidant activity than other flavonoids. Conclusions This is the first study reporting an in-vitro biological investigation for Si and Sr. Especially the chloroform extract of Sr showed potent anticancer and antimicrobial activity. Cynaroside had a highly selective and strong cytotoxicity against T. b. brucei while showing only mild effects against cancer cells. © 2011 The Authors. JPP © 2011 Royal Pharmaceutical Society. |
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| 5. | Biochemistry. 2011 Sep 7. [Epub ahead of print]Amino acid determinants of substrate selectivity in the Trypanasoma brucei sphingolipid synthase family.Goren MA, Fox BG, Bangs JD.AbstractThe substrate selectivity of four Trypanosoma brucei sphingolipid synthases was examined. TbSLS1, an inositol phosphorylceramide (IPC) synthase and TbSLS4, a bi-functional sphingomyelin (SM)/ethanolamine phosphorylceramide (EPC) synthase, were inactivated by Ala substitutions of a conserved triad of residues His210, His253 and Asp257 thought to form part of the active site. TbSLS4 also catalyzed the reverse reaction, production of ceramide from sphingomyelin, but none of the Ala substitutions of the catalytic triad in TbSLS4 were able to do so. Site-directed mutagenesis identified residues proximal to the conserved triad that were responsible for the discrimination between charge and size of the different head groups. For discrimination between anionic (phosphoinositol) and zwitterionic (phosphocholine, phosphoethanolamine) head groups, doubly mutated V172D/S252F TbSLS1 and D172V/F252S TbSLS3 showed reciprocal conversion between IPC and bi-functional SM/EPC synthases. For differentiation of zwitterionic head group size, N170A TbSLS1 and A170N/N187D TbSLS4 showed reciprocal conversion between EPC and bi-functional SM/EPC synthases. These studies provide a mapping of the SLS active site and demonstrate that differences in catalytic specificity of the T. brucei enzyme family are controlled by natural variations in as few as three residue positions. |
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| 6. | Med Parazitol (Mosk). 2011 Apr-Jun;(2):10-5.[The spread and epidemiological value of mosquitoes (Diptera, Psichodidae, Phlebotominae) of the Caucasus]. [Article in Russian] Baranets MS, Darchenkova NN, Ponirovskiĭ EN, Zhirenkina EN.AbstractThe Caucasus mosquito fauna was studied on the basis of the papers published in the 20th century. Due to the new classification developed by M.M. Artemyeva, the presence of 17 mosquito species: P.papatasi, P.sergenti, P.caucasicus, P.alexandri, P.jacusieli, P.kandelakii, P.neglectus, P.per-filiewi, P.tobbi, P.transcaucasicus, P.wenyoni, P.balcanicus, P.brevis, P.halepensis, S.dentate dentate, S.palestinensis, and S.hodsoni pawlowskyi should be considered most significant. The ecology of the mosquito species that are of medical importance is described. Maps of the spread of the mosquitoes that are of epidemiological importance have been complied on the basis of the materials by different authors on the registration of specific mosquito species in the human settlements of the Transcaucasia and North Caucasus. The spread of mosquitoes in the North Caucasus remains inadequately studied today. |
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| 7. | J Immunol Methods. 2011 Jul 29;370(1-2):24-34. Epub 2011 May 17.The use of IgG antibodies in conventional and non-conventional immunodiagnostic tests for early prognosis after treatment of Chagas disease.Wendling AP, Vitelli-Avelar DM, Sathler-Avelar R, Geiger SM, Teixeira-Carvalho A, Gontijo ED, Elói-Santos SM, Martins-Filho OA.SourceLaboratório de Biomarcadores de Diagnóstico e Monitoração, Centro de Pesquisas René Rachou, Fundação Oswaldo Cruz, Belo Horizonte, Minas Gerais, Brazil. AbstractTreatment success of chronically infected Chagas disease patients is laborious and a positive prognosis often is made only after repetitive serological and/or parasitological examinations with continuous negative results. Recently, we have developed a non-conventional flow-cytometric method in order to detect immunoglobulin G antibodies against live trypomastigote forms of Trypanosoma cruzi and showed its usefulness in the prognosis of treatment success. In the present study, we investigated the performance of flow-cytometric anti-live trypomastigote IgG antibodies (FC-ALTA) and flow-cytometric anti-fixed epimastigote IgG antibodies (FC-AFEA), as well as conventional serological methods, for early monitoring of benznidazole treated Chagas disease patients, e.g. 5years after treatment. The analysis of individual FC-ALTA reactivity along the titration curve before and after treatment, we were able to show, that between 4% and 13% of treated patients under evaluation presented with reduced serological reactivity and segregated from the other patient groups. Similar results were obtained with semi-quantitative, conventional indirect hemagglutination or indirect immunofluorescence. Our data therefore suggest that the combined use of conventional and non-conventional serological methods could provide more suitable cure criteria in early post-therapeutic prognosis of Chagas disease. Copyright © 2011 Elsevier B.V. All rights reserved. |
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| 8. | Acta Trop. 2011 Jul;119(1):61-5. Epub 2011 Apr 16.Phylogenetic reconstruction based on Cytochrome b (Cytb) gene sequences reveals dist inct genotypes within Colombian Trypanosoma cruzi I populations.Ramírez JD, Duque MC, Guhl F.SourceCentro de Investigaciones en Microbiología y Parasitología Tropical, Facultad de Ciencias, Universidad de los Andes, Bogotá Cra 1 No. 18A-20, Colombia. AbstractChagas disease caused by Trypanosoma cruzi comprises an important problem of public health in the Americas. This parasite has been recently divided into six Discrete Typing Units (DTUs) due to its high genetic diversity. We sequenced the Cytochorme b (Cytb) gene of 70 T. cruzi I Colombian clones finding four genotypes related to transmission cycles of Chagas disease in Colombia and also to specific hosts of T. cruzi. The genotypes herein described based on Cytb gene sequences are in accordance with those found using the mini-exon gene and reveals once again the enormous genetic diversity at sub-DTU level evidenced in T. cruzi I. Copyright © 2011 Elsevier B.V. All rights reserved. |
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| 9. | Acta Trop. 2011 Jul;119(1):1-4. Epub 2011 Apr 9.Trypanosoma cruzi I diversity: towards the need of genetic subdivision?Guhl F, Ramírez JD.SourceCentro de Investigaciones en Microbiología y Parasitología Tropical, CIMPAT, Universidad de los Andes, Cra 1 No. 18A-10, Bogotá, Colombia. fguhl@uniandes.edu.co AbstractTrypanosoma cruzi the aethiological agent of Chagas disease, a complex zoonoses that affects the American continent is a genetically variable parasite subdivided into six Discrete Typing Units (DTUs). T. cruzi I is the most prevalent DTU affecting the northern countries of America with sporadical cases in the southern countries. T. cruzi I has shown great genetic diversity showing plausible subdivisions needed for this group. Recently, TcI has gained novel importance because of the lately discovered relation with cardiomyopathy manifestations that raises the importance of establishing subdivisions within this DTU. Copyright © 2011 Elsevier B.V. All rights reserved. |
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| 10. | Vet Parasitol. 2011 Jun 10;178(3-4):360-3. Epub 2011 Jan 11.Prevalence of trypanosome infections in dogs from Chagas disease endemic regions in Panama, Central America.Pineda V, Saldaña A, Monfante I, Santamaría A, Gottdenker NL, Yabsley MJ, Rapoport G, Calzada JE.SourceInstituto Conmemorativo Gorgas de Estudios de la Salud, ICGES, Panama. AbstractThe prevalence of canine trypanosomosis was investigated in two Chagas disease endemic rural communities located in the central region of Panama. Serologic tests for Trypanosoma cruzi infection revealed a prevalence of 11.1%. Hemocultures coupled with PCR analysis demonstrated a Trypanosoma rangeli infection rate of 5.1%. An overall trypanosome infection index of 16.2% (16/99) was detected in this canine population. One dog had a mixed infection of T. cruzi and T. rangeli. Six of the trypanosome-infected dogs belong to people who were diagnosed of Chagas disease. We conclude that dogs from this rural area of Panama are frequently infected with trypanosomes transmitted by the sylvatic vector, Rhodnius pallescens, and suggest that dogs are important in the peridomestic transmission cycle of trypanosomes as reservoirs and hosts. The epidemiological implications of these findings are discussed. Copyright © 2011 Elsevier B.V. All rights reserved. |
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