What's new for 'Trypanosomatids' in PubMed

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Sent on Wednesday, 2012 May 16
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 - 8 of 8

1.	J Vector Borne Dis. 2012 Mar;49(1):15-8. Molecular diagnosis of Old World leishmaniasis: Real-time PCR based on tryparedoxin peroxidase gene for the detection and identification of Leishmania spp. Khosravi S, Hejazi SH, Hashemzadeh M, Eslami G, Darani HY. Source Department of Parasitology, Cell and Molecular Research Center, Faculty of Medicine, Shahrekord University of Medical Sciences, Shahrekord; Abstract Background & objectives: Rapid and accurate diagnosis and identification of Leishmania sp causing cutaneous leishmaniasis is crucial in control and therapeutic programs. The problem of diagnosis with traditional methods is that they have a low sensitivity or time consuming but molecular techniques would be an alternative method for rapid and accurate diagnosis. In this work, tryparedoxine peroxidase gene-based real-time PCR was used for accurate identification of Leishmania spp causing Old-World cutaneous leishmaniasis. Methods: In this study, biopsies of specimens were taken from the ulcerative sites in 100 patients and used for direct microscopy, culture in NNN or fixed in alcohol for identification of Leishmania spp using tryparedoxin peroxidase gene-based realtime PCR (qPCR). Results: Using direct microscopy and culture method, Leishmania parasites were isolated from 68 out of 100 patient samples. However, 13 patients with negative finding on traditional tests, had positive results on RT-PCR test. After melting curve analysis of PCR product, Leishmania major in 75 and L. tropica in 4 cases were identified. The sensitivity and specificity of RT-PCR for diagnosis of cutaneous leishmaniasis was 98.7 and 59.8%, respectively. Conclusion: Results of this study showed that RT-PCR was the most sensitive diagnostic test for cutaneous leishmaniasis and represents a tool for rapid species identification.
	PMID: 22585237 [PubMed - in process]
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2.	J Vector Borne Dis. 2012 Mar;49(1):8-14. Sandfly saliva of Lutzomyia ovallesi (Diptera: Psychodidae) as a possible marker for the transmission of Leishmania in Venezuela Andes region. Nieves E, Sánchez Y, Sánchez H, Rondón M, González N, Carrero J. Source Laboratorio de Parasitología Experimental, Departamento de Biología, Facultad de Ciencias, Universidad de Los Andes, Mérida. Abstract Background & objectives: The saliva of the Phlebotominae is highly immunogenic to the vertebrate host and is a determining factor in the Leishmania infection. The aim of this work was to study the saliva of Lutzomyia ovallesi as a possible risk marker for the transmission of Leishmania. Methods: Two populations of L. ovallesi from different geographical areas and subjected to different environmental conditions were compared by geometric morphometry of the wings, by protein profile analysis of salivary glands and by assessing the presence of anti-saliva protein in human sera confronted with laboratory L. ovallesi saliva. Results: The results showed differences in the isometric size and structure of the wings but no allometric effects. Protein profiles of salivary glands of both the L. ovallesi populations studied were found to be similar, based on 11 protein bands with molecular weights ranging from 16 to 99 kDa. Anti-saliva antibodies were present in human sera, but human sera infected and uninfected with leishmaniasis could not be differentiated. Interpretation & conclusion: We conclude that the saliva of laboratory-reared L. ovallesi is representative of that of the wild population. It is suggested to study the presence of anti-saliva antibodies in other species of sandflies and mosquitoes.
	PMID: 22585236 [PubMed - in process]
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3.	Antimicrob Agents Chemother. 2012 May 14. [Epub ahead of print] Optimal Dosing of Miltefosine in Children and Adults with Visceral Leishmaniasis. Dorlo TP, Huitema AD, Beijnen JH, de Vries PJ. Source Division of Infectious Diseases, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands. Abstract Only anecdotal data are available on the pharmacokinetics (PK) of miltefosine in children suffering from visceral leishmaniasis (VL). While failure rates were higher in children with VL, steady-state concentrations appeared lower compared to adults. We hypothesized that the current linear mg/kg dosage is too low for children and that a new dosing algorithm based on an appropriate body size model will result in an optimal exposure. A population PK analysis was performed on three historic pooled datasets, including Indian children, Indian adults and European adults. Linear and allometric scaling of PK parameters by either body weight or fat-free mass (FFM) were evaluated as body size models. Based on the developed PK model, a dosing algorithm for miltefosine in children and adults was proposed and evaluated in silico. The population PK model employing allometric scaling fitted best to the pooled miltefosine data. Allometric scaling by FFM reduced between-subject variability: e.g. for drug clearance from 49.6% to 32.1%. A new allometric miltefosine dosing algorithm was proposed. Exposure to miltefosine was lower in children than adults receiving 2.5 mg/kg/day: a C(max) of 18.8 μg/mL was reached by 90% of adults and 66.7% of children. The allometric daily dose resulted in a similar exposure to miltefosine between adults and children. The use of a new allometric dosing algorithm for miltefosine in VL patients results in optimal exposure to miltefosine in both adults and children and might improve clinical outcome in children.
	PMID: 22585212 [PubMed - as supplied by publisher]
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4.	Ann Hematol. 2012 May 15. [Epub ahead of print] Visceral leishmaniasis infection in a refractory multiple myeloma patient treated with bortezomib. Piro E, Kropp M, Cantaffa R, Lamberti AG, Carillio G, Molica S. Source Department of Oncology and Hematology, Azienda Ospedaliera Pugliese-Ciaccio, Viale Pio X, 88100, Catanzaro, Italy.
	PMID: 22584850 [PubMed - as supplied by publisher]
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5.	Int J Parasitol. 2012 May 11. [Epub ahead of print] Recombinant glycoprotein 63 (Gp63) of Trypanosoma carassii suppresses antimicrobial responses of goldfish (Carassius auratus L.) monocytes and macrophages. Oladiran A, Belosevic M. Source Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada. Abstract We previously reported that proteins secreted by Trypanosoma carassii play a role in evasion of fish host immune responses. To further understand how these parasites survive in the host, we cloned and expressed T. carassii glycoprotein 63 (Tcagp63), and generated a rabbit polyclonal antibody to the recombinant protein (rTcagp63). Tcagp63 was similar to gp63 of other trypanosomes and grouped with Trypanosoma cruzi and Trypanosoma brucei gp63 in phylogenetic analysis. We showed that rTcagp63 down-regulated Aeromonas salmonicida and recombinant goldfish TNFα2-induced production of reactive oxygen and nitrogen intermediates. Macrophages treated with rTcagp63 also exhibited significant reduction in the expression of inducible nitric oxide synthase (iNOS)-A, TNFα-1 and TNFα-2. Recombinant Tcagp63 bound to and was internalized by goldfish macrophages. The Tcagp63 may act by altering the signalling events important in downstream monocyte/macrophage antimicrobial and other cytokine-induced functions. We believe that this is the first report on downregulation of antimicrobial responses by trypanosome gp63. Copyright © 2012. Published by Elsevier Ltd.
	PMID: 22584131 [PubMed - as supplied by publisher]
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6.	Parasitol Int. 2012 May 11. [Epub ahead of print] Canine Cutaneous Leishmaniasis caused by neotropical Leishmania infantum despite of systemic disease: A case report. Cavalcanti A, Lobo R, Cupolillo E, Bustamante F, Porrozzi R. Source Laboratório de Pesquisa em Leishmaniose, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil. Abstract Visceral leishmaniasis is an anthropozoonosis caused by a protozoan Leishmania infantum (syn. Leishmania chagasi). Here, we report a typical case of canine cutaneous leishmaniasis due to L. infantum infection without any other systemic symptom in one dog in the city of Rio de Janeiro, Brazil. A mongrel female dog was admitted in a veterinary clinic with reports of chronic wounds in the body. Physical examination revealed erosive lesions in the limbs, nasal ulcers, presence of ectoparasites and seborrheic dermatitis. Blood samples, fragments of healthy and injured skin were collected. The complete hemogram revealed aregenerative normocytic normochromic anemia and erythrocyte rouleaux, biochemical analysis revealed normal renal and hepatic functions. Cytology of the muzzle and skin lesions suggested pyogranulomatous inflammatory process. The histopathology of a skin fragment was performed and revealed suspicion of protozoa accompanied by necrotizing dermatitis. The diagnosis of leishmaniasis was accomplished by positive serology, isolation of Leishmania from the skin lesion, and also by molecular test (PCR targeting the conserved region of Leishmania kDNA). Culture was positive for damaged skin samples. PCR targeting a fragment of Leishmania hsp70 gene was performed employing DNA extracted from damaged skin. RFLP of the amplified hsp70 fragment identified the parasite as L. infantum, instead of L. braziliensis, the main agent of cutaneous leishmaniasis in Rio de Janeiro. Characterization of isolated promastigotes by five different enzymatic systems confirmed the species identification of the etiological agent. Serology was positive by ELISA and rapid test. This case warns to the suspicion of viscerotropic Leishmania in cases of chronic skin lesions and brings the discussion of the mechanisms involved in the parasite tissue tropism. Copyright © 2012. Published by Elsevier Ireland Ltd.
	PMID: 22583758 [PubMed - as supplied by publisher]
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7.	J Am Chem Soc. 2012 May 13. [Epub ahead of print] Mechanism for Activation of Triosephosphate Isomerase by Phosphite Dianion: The Role of a Hydrophobic Clamp. Malabanan MM, Koudelka AP, Amyes TL, Richard JP. Abstract The role of the hydrophobic side chains of I172 and L232 in catalysis of the reversible isomerization of R glyceraldehyde 3-phosphate (GAP) to dihydroxyacetone phosphate (DHAP) by triosephosphate isomerase (TIM) from Trypanosoma brucei brucei (Tbb) has been investigated. The I172A and L232A mutations result in 100- and 6-fold decreases in kin D(cat)O/Kin D(m)O for the isomerization reaction. The effect of the mutations on the product distributions for the catalyzed reactions of GAP and of [1-(13)C]-glycolaldehyde ([1-(13)C]-GA) in D(2)O is reported. The 40% yield of DHAP from wildtype TbbTIM-catalyzed isomerization of GAP with intramolecular transfer of hydrogen is found to decrease to 12% and to 4%, respectively, for the reactions catalyzed by the I172A and L232A mutants. Likewise, the 12% yield of [2-(13)C]-GA from isomerization of [1-(13)C] GA in D(2)O is found to decrease to 2% and to 1%, respectively, for the reactions catalyzed by the I172A and L232A mutants. The decrease in the yield of the product of intramolecular transfer of hydrogen is consistent with a repositioning of groups at the active site that favors transfer of the substrate derived hydrogen to the protein or the oxygen anion of the bound intermediate. The I172A and L232A mutations result in: (a) A > 10-fold decrease (I172A) and a 17 fold increase (L232A) in the second-order rate constant for TIM-catalyzed proton transfer reactions of [1-(13)C]-GA in D(2)O. (b) A 170-fold decrease (I172A) and 25-fold increase (L232A) in the third-order rate constant for phosphite dianion (HPO(3)(2-)) activation of TIM in D(2)O. (c) A 1.5-fold decrease (I172A) and a larger 16-fold decrease (L232A) in K(d) for activation of TIM by HPO(3)(2-) in D(2)O. The effects of the I172A mutation on the kinetic parameters for wildtype TIM-catalyzed reactions of the whole substrate and substrate pieces are consistent with a decrease in the basicity of the carboxylate side chain of E167 for the mutant enzyme. The data provide striking evidence that the L232A mutation leads to a ca. 1.7 kcal/mol stabilization of a catalytically active loop-closed form of TIM (E(c)) relative to an inactive open form (E(o)).
	PMID: 22583393 [PubMed - as supplied by publisher]
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8.	J Biochem. 2011 Nov;150(5):563-8. doi: 10.1093/jb/mvr096. Epub 2011 Aug 12. Structural insight into the stereoselective production of PGF2α by Old Yellow Enzyme from Trypanosoma cruzi. Okamoto N, Yamaguchi K, Mizohata E, Tokuoka K, Uchiyama N, Sugiyama S, Matsumura H, Inaka K, Urade Y, Inoue T. Source Department of Applied Chemistry, Graduate School of Engineering, Osaka University, Yamada-Oka, Suita, Japan. Abstract Old yellow enzyme (OYE) is an NADPH oxidoreductase capable of reducing a variety of compounds. It contains flavin mononucleotide (FMN) as a prosthetic group. A ternary complex structure of OYE from Trypanosoma cruzi (TcOYE) with FMN and one of the substrates, p-hydroxybenzaldehyde, shows a striking movement around the active site upon binding of the substrate. From a structural comparison of other OYE complexed with 12-oxophytodienoate, we have constructed a complex structure with another substrate, prostaglandin H(2) (PGH(2)), to provide a proposed stereoselective reaction mechanism for the reduction of PGH(2) to prostaglandin F(2α) by TcOYE.
	PMID: 21840922 [PubMed - indexed for MEDLINE]
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