Tuesday, June 16, 2009

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 -10 of 19

1: Saudi Med J. 2009 Jun;30(6):857.

Leishmaniasis resembling hematological malignancies. The concern of differential diagnosis.

Al-Mendalawi MD, Niscola P.

Department of Pediatrics, Al-Kindy College of Medicine, Baghdad University, Baghdad, Iraq.

PMID: 19526178 [PubMed - in process]

2: Mol Cell Proteomics. 2009 Jun 13. [Epub ahead of print]Click here to read

Evidence for a shared nuclear pore complex architecture that is conserved from the last common eukaryotic ancestor.

Degrasse JA, Dubois KN, Devos D, Siegel TN, Sali A, Field MC, Rout MP, Chait BT.

Laboratory for Mass Spectrometry and Gaseous Ion Chemistry, The Rockefeller University, New York, NY 10065.

The nuclear pore complex (NPC) is a macromolecular assembly embedded within the nuclear envelope that mediates bidirectional exchange of material between the nucleus and cytoplasm. Our recent work on the yeast NPC has revealed a simple modularity in its architecture and suggested a common evolutionary origin of the NPC and vesicle coating complexes in a progenitor protocoatomer. However, detailed compositional and structural information is currently only available for vertebrate and yeast NPCs, which are evolutionarily closely related. Hence, our understanding of NPC composition in a full evolutionary context is sparse. Moreover, despite the ubiquitous nature of the NPC, sequence searches in distant taxa have identified surprisingly few NPC components, suggesting that much of the NPC may not be conserved. Thus, in order to gain a broad perspective on the origins and evolution of the NPC, we performed proteomic analyses of NPC-containing fractions from a divergent eukaryote (Trypanosoma brucei) and obtained a comprehensive inventory of its nucleoporins. Strikingly, trypanosome nucleoporins clearly share with metazoa and yeast their fold type, domain organization, composition and modularity. Overall these data provide conclusive evidence that the majority of NPC architecture is indeed conserved throughout the eukaryota, and was already established in the last common eukaryotic ancestor. These findings strongly support the hypothesis that NPCs share a common ancestry with vesicle coating complexes, and that both were established very early in eukaryotic evolution.

PMID: 19525551 [PubMed - as supplied by publisher]

3: J Antimicrob Chemother. 2009 Jun 12. [Epub ahead of print]Click here to read

Transgenic Leishmania donovani clinical isolates expressing green fluorescent protein constitutively for rapid and reliable ex vivo drug screening.

Singh N, Gupta R, Jaiswal AK, Sundar S, Dube A.

Division of Parasitology, Central Drug Research Institute, Lucknow, India.

Objectives Several Leishmania strains with episomal expression of green fluorescent protein (GFP) require constant drug pressure for its continuous expression and hence limit its use in ex vivo or in vivo systems. The aim of this study was to alleviate this problem by stably integrating the GFP gene into the parasite genome, so as to use these transfectants for ex vivo and in vivo drug screening. Methods The GFP gene was integrated downstream of the 18S ribosomal promoter region of Leishmania donovani. After initial selection, GFP-expressing parasites-both sodium stibogluconate (SAG)-susceptible (2001) and -resistant (2039) isolates-were grown without adding G418. The infectivity of these transfectants to macrophages (J774.1) as well as to hamsters was checked. The ex vivo screening assay was standardized using standard antileishmanial drugs. Results A constitutive and enhanced expression of GFP in promastigote and amastigote stages was achieved for approximately 12 months without any need for drug pressure. These transfectants were highly infective to macrophage cell lines as well as to hamsters, as observed by fluorescence microscopy and flow cytometry (FACS). GFP-tagged promastigotes as well as intracellular amastigotes were found to be highly susceptible to miltefosine, amphotericin B and pentamidine, in a concentration-dependent manner. SAG was inactive against the GFP-promastigotes, as well as SAG-resistant intracellular amastigotes, correlating well with earlier reports. Conclusions The GFP-transfectants were found to be suitable for FACS-based ex vivo screening assays. They were also infective to hamsters up to day 60 post-infection.

PMID: 19525291 [PubMed - as supplied by publisher]

4: Mol Biochem Parasitol. 2009 Jun 9. [Epub ahead of print]Click here to read

Cross-species activation of trypanosome S-adenosylmethionine decarboxylase by the regulatory subunit prozyme.

Willert EK, Phillips MA.

Department of Pharmacology, University of Texas Southwestern Medical Center at Dallas, 6001 Forest Park Rd, Dallas, Texas 75390-9041.

The protozoan parasite Trypanosoma cruzi is the causative agent of Chagas disease (American trypanosomiasis), a neglected disease of Central and South America. Polyamines are small organic cations that are required for cell growth and their biosynthesis has been the target of drug discovery efforts in both T. cruzi and the related T. brucei parasites. Here we show that, as previously demonstrated for T. brucei, S-adenosylmethionine decarboxylase (AdoMetDC) from T. cruzi forms a heterodimer with prozyme, an inactive homolog that arose by gene duplication of the canonical enzyme uniquely in the trypanosomatids. The T. cruzi AdoMetDC/prozyme heterodimer is 110-fold more active than homodimeric AdoMetDC. Unlike for T. brucei AdoMetDC, the activity of the T. cruzi heterodimer is further stimulated by putrescine to generate an enzyme with similar catalytic efficiency to the fully activated T. brucei enzyme. The effects of prozyme on T. cruzi AdoMetDC are mediated by an increase in k(cat), while the predominant effect of putrescine is to lower the K(m). Finally we demonstrate that the cross-species heterodimers of T. cruzi and T. brucei AdoMetDC and prozyme pairs are functional, and that putrescine is required for prozyme to fully activate the mixed species heterodimers. These data demonstrate that prozyme mediated activation of AdoMetDC is a common mechanism required to regulate AdoMetDC activity in the trypanosomatids.

PMID: 19523496 [PubMed - as supplied by publisher]

5: Emerg Infect Dis. 2009 Jun;15(6):956-9.

Leishmaniasis, autoimmune rheumatic disease, and anti-tumor necrosis factor therapy, Europe.

Xynos ID, Tektonidou MG, Pikazis D, Sipsas NV.

National and Kapodistrian University of Athens, Athens, Greece.

We report 2 cases of leishmaniasis in patients with autoimmune rheumatic diseases in Greece. To assess trends in leishmaniasis reporting in this patient population, we searched the literature for similar reports from Europe. Reports increased during 2004-2008, especially for patients treated with anti-tumor necrosis factor agents.

PMID: 19523302 [PubMed - in process]

6: Emerg Infect Dis. 2009 Jun;15(6):932-4.

Increasing incidence of zoonotic visceral leishmaniasis on Crete, Greece.

Antoniou M, Messaritakis I, Christodoulou V, Ascoksilaki I, Kanavakis N, Sutton AJ, Carson C, Courtenay O.

University of Crete, Heraklion, Greece.

To determine whether the incidence of canine leishmaniasis has increased on Crete, Greece, we fitted infection models to serodiagnostic records of 8,848 dog samples for 1990-2006. Models predicted that seroprevalence has increased 2.4% (95% confidence interval 1.61%-3.51%) per year and that incidence has increased 2.2- to 3.8-fold over this 17-year period.

PMID: 19523295 [PubMed - in process]

7: Emerg Infect Dis. 2009 Jun;15(6):916-21.

Drought, smallpox, and emergence of Leishmania braziliensis in northeastern Brazil.

Sousa AQ, Pearson R.

Federal University of Ceará, Fortaleza, Brazil. aqsousa@gmail.com

Cutaneous leishmaniasis caused by Leishmania (Vianna) braziliensis is a major health problem in the state of Ceará in northeastern Brazil. We propose that the disease emerged as a consequence of the displacement of persons from Ceará to the Amazon region following the Great Drought and smallpox epidemic of 1877-1879. As the economic and social situation in Ceará deteriorated, approximately 55,000 residents migrated to the Amazon region to find work, many on rubber plantations. Those that returned likely introduced L. (V.) brazilensis into Ceará, where the first cases of cutaneous leishmaniasis were reported early in the 20th century. The absence of an animal reservoir in Ceará, apart from dogs, supports the hypothesis. The spread of HIV/AIDS into the region and the possibility of concurrent cutaneous leishmaniasis raise the possibility of future problems.

PMID: 19523291 [PubMed - in process]

8: Emerg Infect Dis. 2009 Jun;15(6):871-6.

Geographic clustering of leishmaniasis in northeastern Brazil.

Schriefer A, Guimarães LH, Machado PR, Lessa M, Lessa HA, Lago E, Ritt G, Góes-Neto A, Schriefer AL, Riley LW, Carvalho EM.

Universidade Federal da Bahia, Salvador, Brazil. aschriefer@globo.com

To determine whether disease outcomes and clades of Leishmania braziliensis genotypes are associated, we studied geographic clustering of clades and most severe disease outcomes for leishmaniasis during 1999-2003 in Corte de Pedra in northeastern Brazil. Highly significant differences were observed in distribution of mucosal leishmaniasis versus disseminated leishmaniasis (DL) (p<0.0001). Concordance was observed between distribution of these disease forms and clades of L. braziliensis genotypes shown to be associated with these disease forms. We also detected spread of DL over this region and an inverse correlation between frequency of recent DL diagnoses and distance to a previous DL case. These findings indicate that leishmaniasis outcomes are distributed differently within transmission foci and show that DL is rapidly spreading in northeastern Brazil.

PMID: 19523284 [PubMed - in process]

9: Acta Trop. 2009 Jul;111(1):90-3. Epub 2009 Mar 9.Click here to read LinkOut

Predominance of Trypanosoma cruzi genotypes in two reservoirs infected by sylvatic Triatoma infestans of an endemic area of Chile.

Galuppo S, Bacigalupo A, García A, Ortiz S, Coronado X, Cattan PE, Solari A.

Department of Biological Sciences, Faculty of Veterinary Sciences, University of Chile, Santiago, Chile.

We report results of Trypanosoma cruzi infection and parasite genotypes in the wild Octodon degus and synantropic reservoir Rattus rattus from an endemic area with sylvatic Triatoma infestans as the only detected vector. The infection status was determined by hemi-nested PCR directed to minicircles DNA and genotyping by hybridization tests with a panel of five specific probes, including two probes for TcI subgroups (clones 19 and 20). O. degus was found infected with 13.3% and mainly with sublineage TcIId, and less with TcIIb and TcI. Meantime the synantropic R. rattus was found infected with 27.7% and mainly with TcI and much less with TcIId, TcIIb and TcIIe. The results are discussed to explain the distribution of T. cruzi genotypes between these two reservoirs and the importance of sylvatic foci of T. infestans allowing the permanence of the wild and peridomestic cycle of Chagas disease.

PMID: 19426670 [PubMed - indexed for MEDLINE]

10: Acta Trop. 2009 Jul;111(1):51-5. Epub 2009 Mar 5.Click here to read LinkOut

Clinical profile of Trypanosoma cruzi infection in a non-endemic setting: immigration and Chagas disease in Barcelona (Spain).

Muñoz J, Gómez i Prat J, Gállego M, Gimeno F, Treviño B, López-Chejade P, Ribera O, Molina L, Sanz S, Pinazo MJ, Riera C, Posada EJ, Sanz G, Portús M, Gascon J.

Barcelona Centre for International Health Research (CRESIB), IDIBAPS, Hospital Clínic Barcelona, Barcelona, Spain. jose.munoz@manhica.net

BACKGROUND: Chagas disease is no longer limited to Latin America and is becoming frequent in industrialised countries in Europe and United States. METHODS: A descriptive study of Latin American immigrants in Barcelona attending two centres for imported diseases during a period of 3 years. The main outcome was the identification of Trypanosoma cruzi-infected individuals in a non-endemic country and the characterization of their clinical and epidemiological features. RESULTS: A total of 489 Latin American patients participated in the study. Forty-one percent were infected by T. cruzi, and the most frequent country of origin was Bolivia. All T. cruzi infected patients were in chronic stages of infection. 19% of cases had cardiac disorders and 9% had digestive disorders. CONCLUSIONS: A high percentage of participants in this study were infected by T. cruzi and various factors were found to be associated to the infection. It is important to improve clinical and epidemiological knowledge of T. cruzi infection in non-endemic countries and to develop appropriate screening and treatment protocols in these settings.

PMID: 19426663 [PubMed - indexed for MEDLINE]

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