Thursday, July 9, 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 -9 of 9

1: PLoS One. 2009 Jul 8;4(7):e6184.Click here to read

Immunophenotypic lymphocyte profiles in human african trypanosomiasis.

Boda C, Courtioux B, Roques P, Pervieux L, Vatunga G, Josenando T, Ayenengoye CR, Bouteille B, Jauberteau MO, Bisser S.

Université de Limoges, IFR 145 GEIST, Institut de Neurologie Tropicale, EA 3174 NeuroEpidémiologie Tropicale et Comparée, Faculté de Médecine, Limoges, France.

Human African trypanosomiasis (HAT) is a deadly vector-born disease caused by an extracellular parasite, the trypanosome. Little is known about the cellular immune responses elicited by this parasite in humans. We used multiparameter flow cytometry to characterize leukocyte immunophenotypes in the blood and cerebrospinal fluid (CSF) of 33 HAT patients and 27 healthy controls identified during a screening campaign in Angola and Gabon. We evaluated the subsets and activation markers of B and T lymphocytes. Patients had a higher percentage of CD19(+) B lymphocytes and activated B lymphocytes in the blood than did controls, but lacked activated CD4+ T lymphocytes (CD25(+)). Patients displayed no increase in the percentage of activated CD8+ T cells (HLA-DR(+), CD69(+) or CD25(+)), but memory CD8 T-cell levels (CD8(+)CD45RA(-)) were significantly lower in patients than in controls, as were effector CD8 T-cell levels (CD8(+)CD45RA(+)CD62L(-)). No relationship was found between these blood immunophenotypes and disease severity (stage 1 vs 2). However, CD19(+) B-cell levels in the CSF increased with disease severity. The patterns of T and B cell activation in HAT patients suggest that immunomodulatory mechanisms may operate during infection. Determinations of CD19(+) B-cell levels in the CSF could improve disease staging.

PMID: 19584913 [PubMed - in process]

2: Biosci Biotechnol Biochem. 2009 Jul 7. [Epub ahead of print]

Characteristics of Novel Insect Defensin-Based Membrane-Disrupting Trypanocidal Peptides.

Yamage M, Yoshiyama M, Grab DJ, Kubo M, Iwasaki T, Kitani H, Ishibashi J, Yamakawa M.

Innate Immunity Research Unit, National Institute of the Agrobiological Institute.

Synthetic D- and L-amino acid type cationic 9-mer peptides (all sequences were synthesized as D- or L-amino acids) derived from the active sites of insect defensins were tested for their ability to modify the growth of blood-stream form African trypanosomes in vitro. One of them, the D-type peptide A (RLYLRIGRR-NH(2)), irreversibly suppressed proliferation of the Trypanosoma brucei brucei GUTat3.1 parasite. The presence of negatively charged phosphatidylserine on the surface of the parasites was demonstrated, suggesting electrostatic interaction between the peptide and the phospholipids. Furthermore, this peptide was found to alter trypanosome membrane-potentials significantly, an effect apparently due to the removal of the parasite's plasma membrane. The potential toxic effects of D-peptide A on mammalian cells was assessed using human brain microvascular endothelial cells. Only minor effects were found when the endothelial cells were exposed for 16 h to peptide concentrations of less than 200 muM. These findings suggest that insect defensin-based peptides represent a potentially new class of membrane-disrupting trypanocidal drugs.

PMID: 19584534 [PubMed - as supplied by publisher]

3: Ann Trop Med Parasitol. 2009 Jul;103(5):461-6.

Use of multilocus microsatellite typing (MLMT) for the genetic analysis of Indian isolates of Leishmania donovani.

Thakur S, Singh S, Pasha ST, Rawat DS, Lal S, Mittal V.

Division of Biochemistry and Biotechnology, National Institute of Communicable Diseases, 22 Sham Nath Marg, Delhi - 110 054, India.

PMID: 19583916 [PubMed - in process]

4: Ann Trop Med Parasitol. 2009 Jul;103(5):455-9.

Successful use of miltefosine and sodium stibogluconate, in combination, for the treatment of an HIV-positive patient with visceral leishmaniasis: a case report and brief review of the literature.

Collini P, Premchand N, Lockwood D, Greig J.

University of Sheffield School of Medicine and Biomedical Sciences, Royal Hallamshire Hospital, E-Floor, Glossop Road, Sheffield S10 2JF, U.K. p.collini@sheffield.ac.uk.

PMID: 19583915 [PubMed - in process]

5: Ann Trop Med Parasitol. 2009 Jul;103(5):393-400.

Two recent but temporally distinct outbreaks of cutaneous leishmaniasis among foreign workers in the Dead-Sea area of Jordan.

Mosleh IM, Geith E, Schönian G, Kanani KA.

Department of Biological Sciences, Faculty of Science, University of Jordan, Amman, Jordan. i.mosleh@ju.edu.jo.

Two temporally distinct outbreaks of human cutaneous leishmaniasis (CL), as well as scattered cases of the disease, have recently been observed close to the Dead Sea, in Jordan. Each of the two outbreaks, which occurred in 2004/2005 and 2007/2008, involved a group of foreign workers who were deployed within otherwise uninhabited locations. During each outbreak, about 20% of the workers were found infected with the causative parasite. In the earlier outbreak, 61 workers were found to have skin lesions like those of CL and all but three were confirmed by culture and/or the examination of smears (40 cases) or, in the case of 18 (86%) of the 21 suspected cases found smear- and culture-negative, by PCR. In the second outbreak, the cases were only identified from their clinical manifestations and their response to antileishmanial treatment (cryotherapy). Leishmania major was identified as the cause of the 2004/2005 outbreak and some sporadic cases that occurred, in 2004, along the shores of the Dead Sea. The burrows of potential reservoir hosts were found close to the outbreak locations, frequently under the chenopod Seidlitzia rosmarinus. The two outbreaks emphasise the continuing problem posed by the CL focus in the Mid Jordan Valley and its impact on humans who move into the area. Curiously, an investigation on the socio-economic conditions of the workers during the outbreaks identified a group of 48 workers who were living in air-conditioned rooms during the 2007/2008 outbreak, among whom no CL cases were found. In contrast, 26 of a neighbouring group of 124 workers, who were all living in non-air-conditioned rooms, developed CL lesions. The role of air conditioning, and of other factors and measures, in the prevention of the transmission of the causative parasites of CL merits further investigation and the attention of the local health authorities.

PMID: 19583910 [PubMed - in process]

6: Parasit Vectors. 2009 Jul 7;2(1):29. [Epub ahead of print]Click here to read

Trypanocidal activity of the proteasome inhibitor and anti-cancer drug bortezomib.

Steverding D, Wang X.

ABSTRACT: The proteasome inhibitor and anti-cancer drug bortezomib was tested for in vitro activity against bloodstream forms of Trypanosoma brucei. The concentrations of bortezomib required to reduce the growth rate by 50% and to kill all trypanosomes were 3.3 nM and 10 nM, respectively. In addition, bortezomib was 10 times more toxic to trypanosomes than to human HL-60 cells. Moreover, exposure of trypanosomes to 10 nM bortezomib for 16 h was enough to kill 90% of the parasites following incubation in fresh medium. However, proteasomal peptidase activities of trypanosomes exposed to bortezomib were only inhibited by 10% and 30% indicating that the proteasome is not the main target of the drug. The results suggest that bortezomib may be useful as drug for the treatment of human African trypanosomiasis.

PMID: 19583840 [PubMed - as supplied by publisher]

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7: Bull Soc Pathol Exot. 2009 May;102(2):101-5.

[Distribution and ecology of the Savannah human African trypanosomiasis vectors in disturbed forest zone in south Cameroon: about case in the Doumé focus]

[Article in French]

Mbida Mbida JA, Mimpfoundi R, Njiokou F, Manga L, Laveissiere C.

Laboratoire de biologie générale, Faculté des sciences BP 812, Yaoundé, Cameroun. mbidajean@yahoo.fr

Vector control through trapping in the foci of humid forest areas is rather difficult because of the wide spreading of tsetse flies and transmission sites of human African trypanosomiasis. In fact, traps should be a priori set up everywhere to stop the transmission. The identification of the disease transmission sites enables efficient trapping through localisation of dangerous tsetse flies habitats needing vector control measures. The study of adult tsetse flies and teneral tsetse flies spatial distribution and human vector contacts was conducted in Doumb to determine the transmission of human African trypanosomiasis for efficient vector control. Glossina fuscipes fuscipes was the only tsetse fly captured with a very low apparent density of 0.13 tsetse flies per trap and per day. Furthermore, the disease transmission in the focus was not found uniform. In fact, human vector contacts are high in two villages (Paki and Mendin) located in the highly disturbed forest zones. These contacts occur in humid shallows where teneral tsetse flies were only captured around streams and forest galleries. The Doumé focus presents therefore characteristics of savannah focus where river banks and nearby biotopes are the main target sites for vector control campaigns.

PMID: 19583032 [PubMed - in process]

8: Infect Genet Evol. 2009 Mar;9(2):278-82. Epub 2008 Dec 31.Click here to read LinkOut

Congenital Chagas disease involves Trypanosoma cruzi sub-lineage IId in the northwestern province of Salta, Argentina.

Corrales RM, Mora MC, Negrette OS, Diosque P, Lacunza D, Virreira M, Brenière SF, Basombrio MA.

Département Sociétés et Santé, UR016 Caractérisation et Contrôle des Populations de Vecteurs, Institut de Recherche pour le Développement, 911 Av. Agropolis, 34394 Montpellier, France. corrales@mpl.ird.fr

Trypanosoma cruzi is genetically classified into six discrete phylogenetic lineages on the basis of different genetic markers. Identifying lineages circulating among humans in different areas is essential to understand the molecular epidemiology of Chagas disease. In the present study, 18 T. cruzi isolates from congenitally infected newborns in the northwestern province of Salta-Argentina were studied by multilocus enzyme electrophoresis (MLEE) and random amplified polymorphic DNA (RAPD). All isolates were typed by MLEE and RAPD as belonging to T. cruzi IId. Analysis of minor variants of TcIId using probes hybridizing with hypervariable domains of kDNA minicircles, detected three variants with a similar distribution among the isolates. Our findings confirm the presence of T. cruzi IId among congenitally infected newborns in northwestern Argentina and support the assumption that human infection by T. cruzi in the Southern Cone countries of Latin America is due principally to T. cruzi II.

PMID: 19162237 [PubMed - indexed for MEDLINE]

9: Infect Genet Evol. 2009 Mar;9(2):235-40. Epub 2008 Dec 7.Click here to read GSS, LinkOut

Large differences in the genome organization of different plant Trypanosomatid parasites (Phytomonas spp.) reveal wide evolutionary divergences between taxa.

Marín C, Dollet M, Pagès M, Bastien P.

CIRAD, Department of Biological Systems, Research Unit 29 "Etiology wilts" TA A-29/F, 34398 Montpellier Cedex 5, France.

All currently known plant trypanosomes have been grouped in the genus Phytomonas spp., although they can differ greatly in terms of both their biological properties and effects upon the host. Those parasitizing the phloem sap are specifically associated with lethal syndromes in Latin America, such as, phloem necrosis of coffee, 'Hartrot' of coconut and 'Marchitez sorpresiva' of oil palm, that inflict considerable economic losses in endemic countries. The genomic organization of one group of Phytomonas (D) considered as representative of the genus has been published previously. The present work presents the genomic structure of two representative isolates from the pathogenic phloem-restricted group (H) of Phytomonas, analyzed by pulsed field gel electrophoresis followed by hybridization with chromosome-specific DNA markers. It came as a surprise to observe an extremely different genomic organization in this group as compared with that of group D. Most notably, the chromosome number is 7 in this group (with a genome size of 10 Mb) versus 21 in the group D (totalling 25 Mb). These data unravel an unsuspected genomic diversity within plant trypanosomatids, that may justify a further debate about their division into different genera.

PMID: 19111630 [PubMed - indexed for MEDLINE]

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