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Sent on Wednesday, 2010 May 26Search kinetoplastids OR kinetoplastid OR Kinetoplastida OR "trypanosoma brucei" OR leishmania OR brucei OR leishmaniasis OR "African trypanosomiasis"
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| PubMed Results |
| 1. | Parasitol Res. 2010 May 25. [Epub ahead of print]Immune response pattern of the popliteal lymph nodes of dogs with visceral leishmaniasis.Moreira PR, Vieira LM, de Andrade MM, de Barros Bandarra M, Machado GF, Munari DP, de Oliveira Vasconcelos R.Departamento de Patologia Animal, FCAV/UNESP, Jaboticabal, São Paulo, 14884-900, Brazil. AbstractThe present study aimed to estimate the cell response and parasite load in the popliteal lymph nodes of dogs with visceral leishmaniasis (VL), comparing these findings with the clinical staging of the disease. From the necropsy, 33 dogs were classified as symptomatic (S), asymptomatic (A), or oligosymptomatic (O). Cytology and histopathology were used to determine any presence of microscopic lesions and immunohistochemistry, for parasite load. Dog hyperimmune serum was used as the primary antibody. The inflammatory infiltrate in lymph nodes consisted of macrophages and plasmocytes. The granulomas invaded the trabecular and sinusoid regions and sometimes compressed the lymphocytes of the cortical region (atrophy) and medullary cord cells. Parasite load intensity was unrelated to the density of the macrophages infiltrating the lymph node. Significant differences in parasite load (P < 0.05) were observed between the three groups of infected dogs. Follicular hyperplasia of the cortical region occurred among A and O, while follicular atrophy predominated among S. The parasite load was the greatest among S, followed by O. It can be concluded that, regardless of clinical condition, the most evident cell response consisted of macrophages and plasmocytes. Lymphoid atrophy was observed among animals with intense granulomatous reaction and high parasite load, such as among the symptomatic dogs (P < 0.05). Likewise, the oligosymptomatic dogs also presented high density of parasites in the lymph nodes. Thus, we can confirm that dogs with clinical manifestations of VL have an immune system that is less effective for controlling infection by Leishmania chagasi, thereby favoring parasite multiplication. |
| PMID: 20499098 [PubMed - as supplied by publisher] | |
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| 2. | Parasitol Res. 2010 May 25. [Epub ahead of print]Molecular biological identification of monoxenous trypanosomatids and Leishmania from antropophilic sand flies (Diptera: Psychodidae) in Southeast Brazil.de Souza Rocha L, Dos Santos CB, Falqueto A, Grimaldi G Jr, Cupolillo E.Laboratório de Pesquisa em Leishmaniose, Instituto Oswaldo Cruz-FIOCRUZ, Pavilhão Leônidas Deane - sala 509, Av. Brasil 4365, Manguinhos, Rio de Janeiro, Rio de Janeiro, Brazil, 21045-900. |
| PMID: 20499097 [PubMed - as supplied by publisher] | |
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| 3. | Parasitol Res. 2010 May 25. [Epub ahead of print]Diagnosis of visceral leishmaniasis by polymerase chain reaction of DNA extracted from Giemsa's solution-stained slides.Pa ndey K, Pandey BD, Mallik AK, Kaneko O, Uemura H, Kanbara H, Yanagi T, Hirayama K.Department of Immunogenetics, Institute of Tropical Medicine (NEKKEN) and the Global COE Program, Nagasaki University, 1-12-4 Sakamoto, Nagasaki, 852-8523, Japan, pandey_kishor@hotmail.com. AbstractVisceral leishmaniasis (VL) is caused by the protozoan parasite Leishmania donovani and is a potentially fatal disease in endemic areas of the world. Nepal is an endemic area in which VL causes major public health problems in the lowland areas of the southeast regions. The aim of the present study was to evaluate the sensitivity of polymerase chain reaction (PCR) amplification for the detection of Leishmania DNA from Giemsa's solution-stained bone marrow slides. Bone marrow samples were aspirated from a total of 115 VL suspected patients and used to prepare smears on glass slides and for the initiation of in vitro culture. Bone marrow slides were used for microscopic observation, DNA extraction, and subsequent PCR amplification. PCR analysis showed that all the positive samples were of Leishmania parasites. The PCR assay also showed a higher sensitivity (69%) than microscopic examination (57%) and culture (21%). In addition, PCR was able to detect VL in 12% of samples which were negative by microscopy. PCR of DNA extracted from Giemsa's solution-stained bone marrow slides is a suitable tool for confirming diagnosis in patients with VL and may also be useful in the diagnosis of difficult cases. Bone marrow smears are easily stored and can be easily sent to research centers where PCR is available. This makes PCR a good option for diagnosis in the field. |
| PMID: 20499093 [PubMed - as supplied by publisher] | |
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| 4. | Neotrop Entomol. 2010 Mar-Apr;39(2):303-5.Phlebotomine sand flies (Diptera: Psychodidae) of the province of Chaco, Argentina.Rosa JR, Salomon OD, Andrade Filho JD, Carvalho GM, Szelag EA, Stein M, Tapia ES, Brazil RP.Instituto de Medicina Regional, Univ Nacional del Nordeste, Resistencia, Chaco, Argentina. AbstractThe phlebotomine sandflies of the province of Chaco, Argentina, are poorly known, with reports from more than 40 years or captures related with outbreaks of leishmaniasis. In here, Mycropygomyia peresi (Mangabeira) is reported for the first time in Argentina, extending the known dstribution of Migonemyia migonei (França), Evandromyia sallesi (Galvão & Coutinho), Mycropygomyia quinquefer (Dyar), Brumptomyia brumpti (Larousse) y Nemapalpus spp to the province of Chaco. Mg. migonei, together with Nyssomyia neivai (Pinto), Evandromyia cortelezzii (Brèthes), and Psathyromyia shannoni (Dyar) also captured in Chaco, were incriminated as vectors of Leishmania in Argentina. |
| PMID: 20498971 [PubMed - in process] | |
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| 5. | Mol Microbiol. 2010 May 24. [Epub ahead of print]Characterization of a Leishmania Stage Specific Mitochondrial Membrane Protein that Enhances the Activity of Cytochrome C Oxidase and Its Role in Virulence.Dey R, Meneses C, Salotra P, Kamhawi S, Nakhasi HL, Duncan R.Division of Emerging and Transfusion Transmitted Diseases, Center for Biologics Evaluation and Research, FDA, Bethesda, MD, USA. AbstractSummary Leishmaniasis is caused by the dimorphic protozoan parasite Leishmania. Differentiation of the insect form, promastigotes, to the vertebrate form, amastigotes, and survival inside the vertebrate host accompanies a drastic metabolic shift. We describe a gene first identified in amastigotes that is essential for survival inside the host. Gene expression analysis identified a 27kDa protein encoding gene (Ldp27) that was more abundantly expressed in amastigotes and metacyclic promastigotes than in procyclic promastigotes. Immunofluorescence and biochemical analysis revealed that Ldp27 is a mitochondrial membrane protein. Co-imunoprecipitation using antibodies to the cytochrome c oxidase (COX) complex, present in the inner mitochondrial membrane, placed the p27 protein in the COX complex. Ldp27 gene deleted parasites (Ldp27(-/-)) showed significantly less COX activity and ATP synthesis than wild type in intracellular amastigotes. Moreover, the Ldp27(-/-) parasites were less virulent both in human macrophages and in BALB/c mice. These results demonstrate that Ldp27 is an important component of an active COX complex enhancing oxidative phosphorylation specifically in infectious metacyclics and amastigotes and promoting parasite survival in the host. Thus, Ldp27 can be explored as a potential drug target and parasites devoid of the p27 gene could be considered as a live attenuated vaccine candidate against visceral leishmaniasis. |
| PMID: 20497506 [PubMed - as supplied by publisher] | |
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| 6. | Mol Microbiol. 2010 May 24. [Epub ahead of print]Selective inactivation of SIDER2 retro poson-mediated mRNA decay contributes to stage- and species-specific gene expression in Leishmania.Müller M, Padmanabhan PK, Papadopoulou B.Infectious Disease Research Center, CHUL Research Center and Department of Microbiology and Immunology, Faculty of Medicine, Laval University, Quebec, Canada. AbstractSummary Despite their high genomic synteny, the Leishmania major and L. infantum species exhibit extensive differences in mRNA expression patterns throughout the parasite's development. Yet, the underlying mechanisms for this species-specific differential gene expression are largely unknown. Here we report that Short Interspersed DEgenerated Retroposons of the SIDER2 subfamily, shown previously to promote rapid mRNA turnover, confer differential regulation of orthologous transcripts resulting in a stage- and species-specific gene expression. We demonstrate that SIDER2-mediated decay of two L. major transcripts encoding a hypothetical protein and an aminomethyltransferase to a similar extent in promastigote and amastigote developmental forms results in a constitutive low expression of the corresponding proteins. In contrast, their L. infantum orthologs are differentially expressed due to the selective inactivation of SIDER2 in intracellular amastigotes. Inactivation of the SIDER2 function blocks the SIDER2-mediated deadenylation-independent decay pathway, and stabilized transcripts are degraded by a slower, deadenylation-dependent pathway. Sequence variations in SIDER2 retroposons between orthologous transcripts do not contribute to SIDER2 inactivation. Our data suggest that SIDER2 inactivation is 3'-untranslated region (3'UTR) context-dependent and that involves possibly species- and stage-specific trans-acting factor(s). These findings further emphasize the important contribution of SIDER retroposons in the control of gene expression across the Leishmania genus. |
| PMID: 20497500 [PubMed - as supplied by publisher] | |
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| 7. | Mol Microbiol. 2010 May 24. [Epub ahead of print]Localization and induction of the A2 virulence factor in Leishmania: Evidence that A2 is a stress response protein.McCall LI, Matlashewski G.McGill University, Department of Microbiology and Immunology, 3775 University Street, Montreal, Quebec H3A 2B4. AbstractAbstract Leishmaniasis is a vector-borne infectious disease with a wide range of pathologies depending on the species of Leishmania. Leishmania parasites are transmitted by the sand fly vector as promastigotes; within the mammalian host, Leishmania parasites differentiate into amastigotes and replicate in macrophages. The A2 protein from L. donovani is expressed predominantly in amastigotes and therefore likely plays a role in survival in the mammalian host. In the present study, we have determined that the A2 protein colocalized with the Leishmania endoplasmic reticulum (ER) Binding Protein, BiP, was induced by stress and complexed with BiP following heat shock. The A2 gene in L. major is a non-expressed pseudogene and we present evidence that ectopic expression of a transfected A2 gene in L. major enhanced its viability following heat shock. A2 may therefore play a role in protecting L. donovani from stress associated with infection in visceral organs, including the fever typically associated with visceral leishmaniasis. Interestingly, when comparing A2 protein localization, we also observed that the Leishmania Secreted Acid Phosphatase SAcP protein was transported out of the parasite-containing phagolysosome and was located throughout the macrophage cytoplasm in vesicles, providing the first example of a secreted Leishmania-derived protein exiting the parasite-containing phagolysosome. |
| PMID: 20497497 [PubMed - as supplied by publisher] | |
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| 8. | Trop Med Int Health. 2010 May 21. [Epub ahead of print]Sleeping sickness diagnosis: use of buffy coats improves the sensitivity of the mini anion ex change centrifugation test.Camara M, Camara O, Ilboudo H, Sakande H, Kaboré J, N'dri L, Jamonneau V, Bucheton B.Programme National de Lutte contre la Trypanosomose Humaine Africaine, Conakry, Guinée. AbstractSummary Objectives To evaluate a modification of the mini anion exchange centrifugation test (mAECT) for the diagnosis of Trypanosoma brucei (T.b.) gambiense human African trypanosomiasis (HAT). To increase its sensitivity, this test uses 350 mul of buffy coat withdrawn from 5 ml of blood instead of blood. Methods The new protocol was first tested experimentally on serial dilution of trypanosomes and was then further evaluated under field conditions on 57 patients with HAT diagnosed during a medical survey in Guinea. Results Experimentally, the use of buffy coats improved mAECT sensitivity at least five fold and enabled to consistently detect parasites in blood at a concentration of 10 trypanosomes/ml. During the field evaluation, more patients tested positive by mAECT-bc (96.5%) than by mAECT-blood (78.9%, chi(2) = 6.93, P = 0.008) and lymph juice examination (77.2%, chi(2) = 7.67, P = 0.005). Furthermore, the number of parasites per collectors was significantly higher (7.2 vs. 2.6, P = 0.001) when buffy coats were used instead of blood. Conclusion The use of the mAECT-bc protocol enabled a significant improvement of HAT parasitological diagnosis in Guinea, without any additional costs. It would deserve to be tested in other T.b. gambiense endemic areas. |
| PMID: 20497407 [PubMed - as supplied by publisher] | |
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| 9. | Cell Microbiol. 2010 May 20. [Epub ahead of print]Leishmania parasitophorous vacuoles interact continuously with the host cell's endoplasmic reticulum; parasitophoro us vacuoles are hybrid compartments.Ndjamen B, Kang BH, Hatsuzawa K, Kima PE.Department of Microbiology and Cell Science, University of Florida, Building 981, Box 110700, Gainesville, FL 32669, USA. AbstractSummary Macrophages that express representative endoplasmic reticulum (ER) molecules tagged with green fluorescence protein were generated to assess the recruitment of ER molecules to Leishmania parasitophorous vacuoles (PVs). More than 90% of PVs harbouring Leishmania pifanoi or Leishmania donovani parasites recruited calnexin, to their PV membrane. An equivalent proportion of PVs also recruited the membrane-associated soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs), Sec22b. Both ER molecules appeared to be recruited very early in the formation of nascent PVs. Electron microscopy analysis of infected Sec22b/YFP expressing cells confirmed that Sec22b was recruited to Leishmania PVs. In contrast to PVs, it was found that no more than 20% of phagosomes that harboured Zymosan particles recruited calnexin or Sec22b to their limiting phagosomal membrane. The retrograde pathway that ricin employs to access the cell cytosol was exploited to gain further insight into ER-PV interactions. Ricin was delivered to PVs in infected cells incubated with ricin. Incubation of cells with brefeldin A blocked the transfer of ricin to PVs. This implied that molecules that traffic to the ER are transferred to PVs. Moreover the results show that PVs are hybrid compartments that are composed of both host ER and endocytic pathway components. |
| PMID: 20497181 [PubMed - as supplied by publisher] | |
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| 10. | J Med Entomol. 2010 May;47(3):319-28.Distribution and seasonality of Phlebotomus sand flies in cutaneous leishmaniasis foci, Judean Desert, Israel.Orshan L, Szekely D, Khalfa Z, Bitton S.Laboratory of Entomology, Ministry of Health, P.O. Box 34410, Jerusalem 91342, Israel. Laor.Orshan@eliav.health.gov.il AbstractThe ecology of Phlebotomus sand flies in cutaneous leishmaniasis foci as a result of Leishmania tropica in the Judean Desert was studied. Between 2005 and 2007, >265,000 specimens were trapped outdoors and 1,233 specimens were collected indoors. The catches included Phlebotomus sergenti Parrot, Phlebotomus papatasi (Scopoli), Phlebotomus syriacus Adler & Theodor, and Phlebotomus tobbi Adler & Theodor. P. sergenti, the local vector of Leishmania tropica, comprised 90% of outdoor catches, and relatively few were caught indoors. Conversely, P. papatasi were > 90% of the indoor collections, and only a few were caught outdoors. The efficiency of trapping methods varied, but species composition and sex ratio remained constant irrespective of method. Sand flies were abundant on slopes facing east where wind velocity was low, and scarce on slopes facing west and residential areas. Large numbers and high proportion of males that occur near breeding sites were found in man-made rock walls and in rock crevices on slopes of uncultivated hills. Population increase began in April, was more intensive between May and November, peaked in August-September, and significantly decreased in December. Indoors, most of the P. sergenti (< 80%) were collected from September to November. A few sand flies were found between January and March. The effects of climatic factors and human activities on sand fly populations and the risk of Leishmania infections are discussed. |
| PMID: 20496578 [PubMed - in process] | |
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