What's new for 'Trypanosomatids' in PubMed

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Sent on Friday, 2010 Jul 02
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 11

1.	J Biol Chem. 2010 Jun 30. [Epub ahead of print] Analysis of spliceosomal proteins in trypanosomatids reveals novel functions in mRNA processing. Takcz ID, Gupta SK, Volkov V, Romano M, Haham T, Tulinski P, Lebenthal I, Michaeli S. Bar-Ilan University, Israel. Abstract In trypanosomatids, all mRNAs are processed via trans-splicing, though cis-splicing also occurs. In trans-splicing, a common small exon, the spliced leader (SL), which is derived from a small SL RNA species, is added to all mRNAs. Sm and Lsm proteins are core proteins that bind to U snRNAs and are essential for both these splicing processes. In this study, SmD3 and Lsm3 associated complexes were purified to homogeneity from Leishmania tarentolae. The purified complexes were analyzed by mass-spectrometry and 54 and 39 proteins were purified from SmD3 and Lsm complexes, respectively. Interestingly, among the proteins purified from Lsm3, no mRNA degradation factors were detected, as in Lsm complexes from other eukaryotes. The U1A complex was purified and mass-spectrometry analysis identified, in addition to U1 snRNP proteins, additional co-purified proteins including the polyadenylation factor, CPSF73. Defects observed in cells silenced for U1 snRNP proteins suggest that the U1 snRNP functions exclusively in cis-splicing, though U1A also participates in polyadenylation and affects trans-splicing. The study characterized several trypanosome-specific nuclear factors involved in snRNP biogenesis, whose function was elucidated in Trypanosoma brucei. Conserved factors, such as PRP19, which functions at the heart of every cis-spliceosome, also affects SL RNA modification; GEMIN2, a protein associated with SMN (survival of motor neurons) and implicated in selective association of U snRNA with core Sm proteins in trypanosomes, is a master regulator of snRNP assembly. This study demonstrates the existence of trypanosomatid-specific splicing factors, but also that conserved snRNP proteins possess trypanosome-specific functions.
	PMID: 20592024 [PubMed - as supplied by publisher]
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2.	J Leukoc Biol. 2010 Jul;88(1):1-3. Editorial: Leishmania survival mechanisms: the role of host phosphatases. Shio MT, Olivier M. 1. Department of Microbiology and Immunology, Duff Medical Building, Room 610, 3775 University St., Montreal, Quebec, Canada H3A2B4. martin.olivier@mcgill.ca.
	PMID: 20591873 [PubMed - in process]
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3.	Curr Opin Microbiol. 2010 Jun 28. [Epub ahead of print] Parasites in motion: flagellum-driven cell motility in African trypanosomes. Hill KL. Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, 609 Charles E. Young Drive, Los Angeles, CA 90095, United States. Abstract Motility of the sleeping sickness parasite, Trypanosoma brucei, impacts disease transmission and pathogenesis. Trypanosome motility is driven by a flagellum that harbors a canonical 9+2 axoneme, together with trypanosome-specific elaborations. Trypanosome flagellum biology and motility have been the object of intense research over the last two years. These studies have led to the discovery of a novel form of motility, termed social motility, and provided revision of long-standing models for cell propulsion. Recent work has also uncovered novel structural features and motor proteins associated with the flagellar apparatus and has identified candidate signaling molecules that are predicted to regulate flagellar motility. Together with earlier inventories of flagellar proteins from proteomic and genomic studies, the stage is now set to move forward with functional studies to elucidate molecular mechanisms and investigate parasite motility in the context of host-parasite interactions. Copyright © 2010. Published by Elsevier Ltd.
	PMID: 20591724 [PubMed - as supplied by publisher]
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4.	Vet Parasitol. 2010 May 25. [Epub ahead of print] Prevention of endemic canine vector-borne diseases using i midacloprid 10% and permethrin 50% in young dogs: A longitudinal field study. Otranto D, de Caprariis D, Lia RP, Tarallo V, Lorusso V, Testini G, Dantas-Torres F, Latrofa S, Diniz PP, Mencke N, Maggi RG, Breitschwerdt E, Capelli G, Stanneck D. Dipartimento di Sanità Pubblica e Zootecnia, Università degli Studi di Bari, Valenzano, BA, Italy. Abstract Canine vector-borne diseases (CVBDs) are highly prevalent and increasing in distribution worldwide. A longitudinal study was conducted in southern Italy to determine the incidence of and protection against CVBD-causing pathogens in dogs treated with a combination of imidacloprid 10% and permethrin 50% (ImPer). One hundred eleven autochthonous young dogs were divided into group A (n=63) and group B (n=48), both groups containing dogs positive and negative for one or more CVBD-causing pathogens. Additionally, 10 naïve male beagles were introduced in each group in May 2008. Group A was treated with ImPer on day 0 and every 21+/-2 days whereas group B was left untreated. Blood and skin samples were collected at baseline (March-April 2008) and at the first, second and third follow-up times (July and October 2008 and April 2009). Bone marrow was sampled at baseline and at the third follow-up. Serological, cytological and molecular tests were performed to detect Anaplasma platys, Babesia spp., Bartonella spp., Dirofilaria immitis, Ehrlichia canis, Hepatozoon canis and Leishmania infantum. Ectoparasites (fleas, ticks, and sand flies) were monitored throughout the study. The baseline prevalence of CVBDs was 39.6% with 44 dogs positive for at least one pathogen. A. platys (27.5%) and Babesia spp. (15.6%) were the most prevalent species and co-infections with up to two pathogens were detected in 16 (14.7%) individuals. At the end of the evaluation period, there was a 90.7% reduction in overall CVBD incidence density rate (IDR) in group A, as following: 100% reduction in L. infantum; 94.6% in E. canis; 94.4% in Babesia spp.; and 81.8% in A. platys. Initially positive treated dogs showed significantly lower pathogen prevalence at the third follow-up than untreated ones. At the end of the evaluation period, 8 of the 10 untreated beagles were infected with at least one pathogen whereas one of the treated beagles was A. platys positive at a single time point (second follow-up). Overall efficacy against ticks was 97.9%. In October 2009, samples were collected from the remaining 83 dogs (44 from group A and 39 from group B) to investigate the annual incidence of CVBDs in the same, at this time untreated, dog population. A high year incidence for tick-borne diseases (78.1%) and for L. infantum (13.6%) was detected in dogs from group A, seven months after the treatment had been withdrawn. The results demonstrate that ImPer preventive treatment against arthropods protects autochthonous and naïve beagle dogs against CVBD-causing pathogens. Copyright © 2010 Elsevier B.V. All rights reserved.
	PMID: 20591573 [PubMed - as supplied by publisher]
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5.	Parasite Immunol. 2010 Jul;32(7):479-83. Human visceral leishmaniasis is not associated with expansion or accumulation of Foxp3(+) CD4 cells in blood or spleen. Maurya R, Kumar R, Prajapati VK, Manandhar KD, Sacks D, Sundar S, Nylén S. Department of Medicine, Institute of Medical Sciences, Banaras Hindu University, Varanasi, India. Abstract Summary Natural regulatory T cells (CD4(+) CD25(+) Foxp3(+)), natural regulatory T cells (nTreg), play an important role in the regulation of inflammatory immune responses. However, the immunosuppressive properties of nTreg may unfavourably affect the host's ability to clear certain infections. In human visceral leishmaniasis (VL), reports on the frequency and function of nTreg are not conclusive. A limitation of our own previous studies that did not indicate a major role for Foxp3(+) nTreg in VL pathogenesis was that Foxp3 was measured by mRNA expression alone, as other tools were not available at the time. We have in this study assessed CD4(+)CD25(+)Foxp3(+) cells in splenic aspirates and peripheral blood mononuclear cells (PBMC) from an extensive series of patients with VL and endemic controls (EC) by flow cytometry (FACS). The results do not show increased frequencies of Foxp3(+) cells in patient with VL pre- and post-treatment, neither were they elevated when compared to PBMC of EC. We conclude that active VL is not associated with increased frequencies of peripheral Foxp3 Treg or accumulation at the site of infection.
	PMID: 20591118 [PubMed - in process]
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6.	Trop Med Int Health. 2010 Jul;15(s2):55-62. Management of visceral leishmaniasis in rural primary health care services in Bihar, India. Hasker E, Singh SP, Malaviya P, Singh RP, Shankar R, Boelaert M, Sundar S. Epidemiology and Disease Control Unit, Department of Public Health, Institute of Tropical Medicine, Antwerp, Belgium. Abstract Objective In 2005 a visceral leishmaniasis (VL) elimination initiative was launched on the Indian subcontinent, with early diagnosis based on a rapid diagnostic test and treatment with the oral drug miltefosine as its main strategy. Several recent studies have signaled underreporting of VL cases in the region. Information on treatment outcomes is scanty. Our aim was to document VL case management by the primary health care services in India. Methods We took a random sample of all VL patients registered in rural primary health care (PHC) facilities of Muzaffarpur district, Bihar, India during 2008. Patients were traced at home for an interview and their records were reviewed. We recorded patient and doctor delay, treatment regimens, treatment outcomes and costs incurred by patients. Results We could review records of all 150 patients sampled and interview 139 patients or their guardian. Most patients (81%) had first presented to unqualified practitioners; median delay before reaching the appropriate primary healthcare facility was 40 days (IQR 31-59 days). Existing networks of village health workers were under-used. 48% of VL patients were treated with antimonials; 40% of those needed a second treatment course. Median direct expenditure by patients was 4000 rupees per episode (IQR 2695-5563 rupees), equivalent to almost 2 months of household income. Conclusion In 2008 still critical flaws remained in VL case management in the primary health care services in Bihar: obsolete use of antimonials with high failure rates and long patient delay. To meet the target of the VL elimination, more active case detection strategies are needed, and village health worker networks could be more involved. Costs to patients remain an obstacle to early case finding.
	PMID: 20591081 [PubMed - as supplied by publisher]
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7.	Trop Med Int Health. 2010 Jul;15(s2):1-3. The burden of visceral leishmaniasis in South Asia. Meheus F, Boelaert M. Department of Public Health, Institute of Tropical Medicine, Antwerp, Belgium.
	PMID: 20591079 [PubMed - as supplied by publisher]
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8.	Exp Dermatol. 2010 Jun 29. [Epub ahead of print] Leishmaniasis, contact hypersensitivity and graft-versus-host disease: understanding the role of dendritic cell subsets in balancing skin immunity and tolerance. Kautz-Neu K, Meyer RG, Clausen BE, von Stebut E. Department of Dermatology, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany. Abstract Please cite this paper as: Leishmaniasis, contact hypersensitivity and graft-versus-host disease: understanding the role of dendritic cell subsets in balancing skin immunity and tolerance. Experimental Dermatology 2010. Abstract: Dendritic cells (DC) are key elements of the immune system. In peripheral tissues, they function as sentinels taking up and processing antigens. After migration to the draining lymph nodes, the DC either present antigenic peptides by themselves or transfer them to lymph node-resident DC. The skin is the primary interface between the body and the environment and host's various DC subsets, including dermal DC (dDC) and Langerhans cells (LC). Because of their anatomical position in the epidermis, LC are believed to be responsible for induction of adaptive cutaneous immune responses. The functions of LC and dDC in the skin immune system in vivo are manifold, and it is still discussed controversially whether the differentiation of T-cell subtypes (e.g. effector T cells and regulatory T cells) may be initiated by distinct DC subtypes. As skin DC are able to promote or downmodulate immune responses, we chose different skin diseases (cutaneous leishmaniasis, contact hypersensitivity, UV radiation-induced suppression, and graft-versus-host disease) to describe the biological interactions between different DC subtypes and T cells that lead to the development of efficient or unwanted immune responses. A detailed knowledge about the immune modulatory capacity of different cutaneous DC subsets might be helpful to specifically target these cells through the skin during therapeutic interventions.
	PMID: 20590820 [PubMed - as supplied by publisher]
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9.	Arch Physiol Biochem. 2010 Jun 30. [Epub ahead of print] Probing the dynamic nature of signalling pathways by IMAC and SELDI-tof MS. Foucher AL, Späth GF, Pemberton IK. Photeomix, 34 rue Carnot, 93160 Noisy le Grand, France. Abstract One major obstacle to the analysis of signalling pathways is the dynamic nature of signalling response to environmental stimuli. To overcome this limitation we applied immobilized metal affinity chromatography (IMAC) in combination with SELDI-tof MS to investigate the temporal variation of protein phosphorylation. We analysed the phospho-proteome variations in our model organism, Leishmania donovani, in response to changes in pH and temperature, which induce differentiation from promastigotes to amastigotes. Investigation of total cell extracts did not allow promastigote and amastigote life cycle stages to be distinguished. However, using IMAC enriched samples, the pattern and intensity of phospho-proteins analysed distinguished both stages reproducibly. Approximately 61% of the phospho-proteins analysed were significantly different in abundance (p<0.02). Of these 61%, 73% showed an increased phosphorylation in promastigotes while 27% showed an increase phosphorylation in amastigotes. The workflow developed is currently being applied to the temporal analysis of environmental stimuli.
	PMID: 20590411 [PubMed - as supplied by publisher]
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10.	J Parasitol. 2010 Jun;96(3):547-51. Factors associated with Trypanosoma cruzi exposure among domestic canines in Tennessee. Rowland ME, Maloney J, Cohen S, Yabsley MJ, Huang J, Kranz M, Green A, Dunn JR, Carpenter LR, Jones TF, Moncayo AC. Department of Ecology, Marine Science Institute, University of California, Santa Barbara, California 93106-9610, USA. shaw@lifesci.ucsb.edu Abstract Trypanosoma cruzi , the etiologic agent of Chagas' disease, is enzootic in animal populations of the southeastern United States. In the United States, T. cruzi prevalence has been reported for over 20 different wildlife species, and 7 autochthonous human cases have been documented since 1955. Previous canine (Canis familiaris) serosurveys have been limited either by small sample size or confined geographic reporting areas. In this study, we report a seroprevalence of 6.4% among 860 canines from 31 counties and 5 ecoregions throughout Tennessee, using an indirect immunofluorescent assay (IFA). Statistically significant associations between seropositivity and age, weight, and outdoor living were noted. Differences in seropositivity were not seen based on American Kennel Club (AKC) group, sex, habitat, land cover, and ecoregion. Greater attention should be given to possible T. cruzi transmission in Tennessee and veterinarians should consider Chagas' disease as a differential diagnosis with compatible signs.
	PMID: 20557201 [PubMed - indexed for MEDLINE]
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