Taxonomy Icon Data: Trypanosoma brucei [Taxonomy Icon

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Full Text Available Trypanosoma brucei Trypanosoma brucei Trypanosoma_brucei_L.png Trypanosoma_brucei_NL.png Trypanoso...ma_brucei_S.png Trypanosoma_brucei_NS.png http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Trypanoso...ma+brucei&t=L http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Trypanosoma+brucei&t=NL http://bioscie...ncedbc.jp/taxonomy_icon/icon.cgi?i=Trypanosoma+brucei&t=S http://biosciencedbc.jp.../taxonomy_icon/icon.cgi?i=Trypanosoma+brucei&t=NS http://togodb.biosciencedbc.jp/togodb/view/taxonomy_icon_comment_en?species_id=121 ...

Comparative Genomics of Glossina palpalis gambiensis and G. morsitans morsitans to Reveal Gene Orthologs Involved in Infection by Trypanosoma brucei gambiense.

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Hamidou Soumana, Illiassou; Tchicaya, Bernadette; Rialle, Stéphanie; Parrinello, Hugues; Geiger, Anne

2017-01-01

Blood-feeding Glossina palpalis gambiense (Gpg) fly transmits the single-celled eukaryotic parasite Trypanosoma brucei gambiense (Tbg), the second Glossina fly African trypanosome pair being Glossina morsitans / T .brucei rhodesiense. Whatever the T. brucei subspecies, whereas the onset of their developmental program in the zoo-anthropophilic blood feeding flies does unfold in the fly midgut, its completion is taking place in the fly salivary gland where does emerge a low size metacyclic trypomastigote population displaying features that account for its establishment in mammals-human individuals included. Considering that the two Glossina - T. brucei pairs introduced above share similarity with respect to the developmental program of this African parasite, we were curious to map on the Glossina morsitans morsitans (Gmm), the Differentially Expressed Genes (DEGs) we listed in a previous study. Briefly, using the gut samples collected at days 3, 10, and 20 from Gpg that were fed or not at day 0 on Tbg-hosting mice, these DGE lists were obtained from RNA seq-based approaches. Here, post the mapping on the quality controlled DEGs on the Gmm genome, the identified ortholog genes were further annotated, the resulting datasets being compared. Around 50% of the Gpg DEGs were shown to have orthologs in the Gmm genome. Under one of the three Glossina midgut sampling conditions, the number of DEGs was even higher when mapping on the Gmm genome than initially recorded. Many Gmm genes annotated as "Hypothetical" were mapped and annotated on many distinct databases allowing some of them to be properly identified. We identify Glossina fly candidate genes encoding (a) a broad panel of proteases as well as (b) chitin-binding proteins, (c) antimicrobial peptide production-Pro3 protein, transferrin, mucin, atttacin, cecropin, etc-to further select in functional studies, the objectives being to probe and validated fly genome manipulation that prevents the onset of the developmental

Trypanosoma brucei gambiense group 1 is distinguished by a unique amino acid substitution in the HpHb receptor implicated in human serum resistance.

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Rebecca E Symula

Full Text Available Trypanosoma brucei rhodesiense (Tbr and T. b. gambiense (Tbg, causative agents of Human African Trypanosomiasis (sleeping sickness in Africa, have evolved alternative mechanisms of resisting the activity of trypanosome lytic factors (TLFs, components of innate immunity in human serum that protect against infection by other African trypanosomes. In Tbr, lytic activity is suppressed by the Tbr-specific serum-resistance associated (SRA protein. The mechanism in Tbg is less well understood but has been hypothesized to involve altered activity and expression of haptoglobin haemoglobin receptor (HpHbR. HpHbR has been shown to facilitate internalization of TLF-1 in T.b. brucei (Tbb, a member of the T. brucei species complex that is susceptible to human serum. By evaluating the genetic variability of HpHbR in a comprehensive geographical and taxonomic context, we show that a single substitution that replaces leucine with serine at position 210 is conserved in the most widespread form of Tbg (Tbg group 1 and not found in related taxa, which are either human serum susceptible (Tbb or known to resist lysis via an alternative mechanism (Tbr and Tbg group 2. We hypothesize that this single substitution contributes to reduced uptake of TLF and thus may play a key role in conferring serum resistance to Tbg group 1. In contrast, similarity in HpHbR sequence among isolates of Tbg group 2 and Tbb/Tbr provides further evidence that human serum resistance in Tbg group 2 is likely independent of HpHbR function.

The role of domestic animals in the epidemiology of human African trypanosomiasis in Ngorongoro conservation area, Tanzania.

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Ruiz, Juan P; Nyingilili, Hamisi S; Mbata, Geofrey H; Malele, Imna I

2015-10-06

Trypanosomiasis is a neglected tropical disease caused by the trypanosome parasite and transmitted by the tsetse fly vector. In Sub-saharan Africa, both the human and animal variants of the disease are a great obstacle towards agriculture, development, and health. In order to better understand and therefore combat Trypanosomiasis, characterizing disease hotspots across species is critical. In this study, 193 samples from cattle, sheep, and goats were collected from eight sites. Samples were taken from animals belonging mostly to Maasai herdsmen in the Ngorongoro Crater Conservation Area (NCA) and analysed for the presence of trypanosomiasis infection using PCR techniques. Those that tested positive for T. brucei parasite were further tested using SRA LAMP technique to check for T. brucei rhodesiense, the human infective subspecies of parasite. Our study found a high incidence of Trypanosoma brucei infections across species. Of animals tested, 47 % of cattle, 91.7 % of sheep, and 60.8 % of goats were infected. Most of the infections were of the T. brucei species. We also identified sheep and goats as carriers of the T. brucei rhodesiense subspecies, which causes acute human trypanosomiasis. Together, these results point toward the need for stricter control strategies in the area to prevent disease outbreak.

Non-cytochrome mediated mitochondrial ATP production in bloodstream form Trypanosoma brucei brucei

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Bienen, E. J.; Maturi, R. K.; Pollakis, G.; Clarkson, A. B.

1993-01-01

The life cycle of Trypanosoma brucei brucei involves a series of differentiation steps characterized by marked changes in mitochondrial development and function. The bloodstream forms of this parasite completely lack cytochromes and have not been considered to have any Krebs cycle function. It has

PLS-Prediction and Confirmation of Hydrojuglone Glucoside as the Antitrypanosomal Constituent of Juglans Spp.

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Therese Ellendorff

2015-05-01

Full Text Available Naphthoquinones (NQs occur naturally in a large variety of plants. Several NQs are highly active against protozoans, amongst them the causative pathogens of neglected tropical diseases such as human African trypanosomiasis (sleeping sickness, Chagas disease and leishmaniasis. Prominent NQ-producing plants can be found among Juglans spp. (Juglandaceae with juglone derivatives as known constituents. In this study, 36 highly variable extracts were prepared from different plant parts of J. regia, J. cinerea and J. nigra. For all extracts, antiprotozoal activity was determined against the protozoans Trypanosoma cruzi, T. brucei rhodesiense and Leishmania donovani. In addition, an LC-MS fingerprint was recorded for each extract. With each extract’s fingerprint and the data on in vitro growth inhibitory activity against T. brucei rhodesiense a Partial Least Squares (PLS regression model was calculated in order to obtain an indication of compounds responsible for the differences in bioactivity between the 36 extracts. By means of PLS, hydrojuglone glucoside was predicted as an active compound against T. brucei and consequently isolated and tested in vitro. In fact, the pure compound showed activity against T. brucei at a significantly lower cytotoxicity towards mammalian cells than established antiprotozoal NQs such as lapachol.

Genetic control of resistance to Trypanosoma brucei brucei infection in mice

Czech Academy of Sciences Publication Activity Database

Šíma, Matyáš; Havelková, Helena; Quan, L.; Svobodová, M.; Jarošíková, T.; Vojtíšková, Jarmila; Stassen, A. P. M.; Demant, P.; Lipoldová, Marie

2011-01-01

Roč. 5, č. 6 (2011), e1173 ISSN 1935-2735 R&D Projects: GA AV ČR IAA500520606; GA MŠk(CZ) LC06009 Grant - others:NIH-NCI(US) 1R01CA127162-01 Institutional research plan: CEZ:AV0Z50520514 Keywords : Trypanosoma brucei brucei * mouse recombinant congenic strains * Tbbr Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.716, year: 2011

Analytical purification of a 60-kDa target protein of artemisinin detected in Trypanosoma brucei brucei

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Benetode Konziase

2015-12-01

Full Text Available Here we describe the isolation and purity determination of Trypanosoma brucei (T. b. brucei candidate target proteins of artemisinin. The candidate target proteins were detected and purified from their biological source (T. b. brucei lysate using the diazirine-free biotinylated probe 5 for an affinity binding to a streptavidin-tagged resin and, subsequently, the labeled target proteins were purified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE. We herein showed the electrophoresis gel and the immunoblotting film containing the 60-kDa trypanosomal candidate target protein of artemisinin as a single band, which was visualized on-gel by the reverse-staining method and on a Western blotting film by enhanced chemiluminescence. The data provided in this article are related to the original research article “Biotinylated probes of artemisinin with labeling affinity toward Trypanosoma brucei brucei target proteins”, by Konziase (Anal. Biochem., vol. 482, 2015, pp. 25–31. http://dx.doi.org/10.1016/j.ab.2015.04.020.

Detection of human-infective trypanosomes in acutely-infected Jack ...

African Journals Online (AJOL)

A diagnosis of acute canine African trypanosomosis was made by microscopic examination of blood smear. Loop-mediated isothermal amplification (LAMP) analysis, using primers specifically targeting the human serum resistanceassociated (SRA) gene, revealed a monolytic infection with Trypanosoma brucei rhodesiense ...

CHARACTERIZATION AND ANTIPARASITIC ACTIVITY OF BENZOPHENONE THIOSEMICARBAZONES ON Trypanosoma brucei brucei

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Georges C. Accrombessi

2011-02-01

Full Text Available The structure of four synthesized thiosemicarbazones, substituted or not, of benzophenone has been confirmed by spectrometrical analysis IR, NMR 1H and 13C. Their anti-trypanosomal activities were evaluated on Trypanosoma brucei brucei. Among these compounds, benzophenone 4 phenyl-3-thiosemicarbazone 4 has the highest activity with the half-inhibitory concentration (IC50 = 8.48 micromolar (µM. Benzophenone 4-methyl-3-thiosemicarbazone 3 and benzophenone thiosemicarbazone 1 showed moderate anti-trypanosomal activity with IC50 values equal to 23.27 µM and 67.17 µM respectively. Benzophenone 2 methyl-3-thiosemicarbazone 2 showed no activity up to IC50 = 371.74 µM.

Isothermal microcalorimetry, a new tool to monitor drug action against Trypanosoma brucei and Plasmodium falciparum.

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Tanja Wenzler

Full Text Available Isothermal microcalorimetry is an established tool to measure heat flow of physical, chemical or biological processes. The metabolism of viable cells produces heat, and if sufficient cells are present, their heat production can be assessed by this method. In this study, we investigated the heat flow of two medically important protozoans, Trypanosoma brucei rhodesiense and Plasmodium falciparum. Heat flow signals obtained for these pathogens allowed us to monitor parasite growth on a real-time basis as the signals correlated with the number of viable cells. To showcase the potential of microcalorimetry for measuring drug action on pathogenic organisms, we tested the method with three antitrypanosomal drugs, melarsoprol, suramin and pentamidine and three antiplasmodial drugs, chloroquine, artemether and dihydroartemisinin, each at two concentrations on the respective parasite. With the real time measurement, inhibition was observed immediately by a reduced heat flow compared to that in untreated control samples. The onset of drug action, the degree of inhibition and the time to death of the parasite culture could conveniently be monitored over several days. Microcalorimetry is a valuable element to be added to the toolbox for drug discovery for protozoal diseases such as human African trypanosomiasis and malaria. The method could probably be adapted to other protozoan parasites, especially those growing extracellularly.

Challenges in the diagnosis and management of sleeping sickness ...

African Journals Online (AJOL)

Blood and cerebrospinal fluid (CSF) samples were examined for the presence of trypanosomes using wet film, Field\\'s stain and concentration techniques. Typanosoma brucei rhodesiense were detected in both the blood and CSF samples. The patient was treated successfully with melarsoprol. The results of this case study ...

Quantitative Structure ‒ Antiprotozoal Activity Relationships of Sesquiterpene Lactones

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Reto Brun

2009-06-01

Full Text Available Prompted by results of our previous studies where we found high activity of some sesquiterpene lactones (STLs against Trypanosoma brucei rhodesiense (which causes East African sleeping sickness, we have now conducted a structure-(in-vitro-activity study on a set of 40 STLs against T. brucei rhodesiense, T. cruzi, Leishmania donovani and Plasmodium falciparum. Furthermore, cytotoxic activity against L6 rat skeletal myoblast cells was assessed. Some of the compounds possess high activity, especially against T. brucei (e.g. helenalin and some of its esters with IC50-values of 0.05-0.1 µM, which is about 10 times lower than their cytotoxic activity. It was found that all investigated antiprotozoal activities are significantly correlated with cytotoxicity and the major determinants for activity are a,b-unsaturated structural elements, also known to be essential for other biological activities of STLs. It was observed, however, that certain compounds are considerably more toxic against protozoa than against mammalian cells while others are more cytotoxic than active against the protozoa. A comparative QSAR analysis was therefore undertaken, in order to discern the antiparasitic activity of STLs against T. brucei and cytotoxicity. Both activities were found to depend to a large extent on the same structural elements and molecular properties. The observed variance in the biological data can be explained in terms of subtle variations in the relative influences of various molecular descriptors.

Cynaropicrin targets the trypanothione redox system in Trypanosoma brucei.

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Zimmermann, Stefanie; Oufir, Mouhssin; Leroux, Alejandro; Krauth-Siegel, R Luise; Becker, Katja; Kaiser, Marcel; Brun, Reto; Hamburger, Matthias; Adams, Michael

2013-11-15

In mice cynaropicrin (CYN) potently inhibits the proliferation of Trypanosoma brucei-the causative agent of Human African Trypanosomiasis-by a so far unknown mechanism. We hypothesized that CYNs α,β-unsaturated methylene moieties act as Michael acceptors for glutathione (GSH) and trypanothione (T(SH)2), the main low molecular mass thiols essential for unique redox metabolism of these parasites. The analysis of this putative mechanism and the effects of CYN on enzymes of the T(SH)2 redox metabolism including trypanothione reductase, trypanothione synthetase, glutathione-S-transferase, and ornithine decarboxylase are shown. A two step extraction protocol with subsequent UPLC-MS/MS analysis was established to quantify intra-cellular CYN, T(SH)2, GSH, as well as GS-CYN and T(S-CYN)2 adducts in intact T. b. rhodesiense cells. Within minutes of exposure to CYN, the cellular GSH and T(SH)2 pools were entirely depleted, and the parasites entered an apoptotic stage and died. CYN also showed inhibition of the ornithine decarboxylase similar to the positive control eflornithine. Significant interactions with the other enzymes involved in the T(SH)2 redox metabolism were not observed. Alongside many other biological activities sesquiterpene lactones including CYN have shown antitrypanosomal effects, which have been postulated to be linked to formation of Michael adducts with cellular nucleophiles. Here the interaction of CYN with biological thiols in a cellular system in general, and with trypanosomal T(SH)2 redox metabolism in particular, thus offering a molecular explanation for the antitrypanosomal activity is demonstrated. At the same time, the study provides a novel extraction and analysis protocol for components of the trypanosomal thiol metabolism. Copyright © 2013 Elsevier Ltd. All rights reserved.

Evaluation of an ethnopharmacologically selected Bhutanese medicinal plants for their major classes of phytochemicals and biological activities.

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Wangchuk, Phurpa; Keller, Paul A; Pyne, Stephen G; Taweechotipatr, Malai; Tonsomboon, Aunchalee; Rattanajak, Roonglawan; Kamchonwongpaisan, Sumalee

2011-09-01

As many as 229 medicinal plants have been currently used in the Bhutanese Traditional Medicine (BTM) as a chief ingredient of polyherbal formulations and these plants have been individually indicated for treating various types of infections including malaria, tumor, and microbial. We have focused our study only on seven species of these plants. We aim to evaluate the antiplasmodial, antimicrobial, anti-Trypanosoma brucei rhodesiense and cytotoxicity activities of the seven medicinal plants of Bhutan selected using an ethno-directed bio-rational approach. This study creates a scientific basis for their use in the BTM and gives foundation for further phytochemical and biological evaluations which can result in the discovery of new drug lead compounds. A three stage process was conducted which consisted of: (1) an assessment of a pharmacopoeia and a formulary book of the BTM for their mode of plant uses; (2) selecting 25 anti-infective medicinal plants based on the five established criteria, collecting them, and screening for their major classes of phytochemicals using appropriate test protocols; and (3) finally analyzing the crude extracts of the seven medicinal plants, using the standard test protocols, for their antiplasmodial, antimicrobial, anti-Trypanosoma brucei rhodesiense and cytotoxicity activities as directed by the ethnopharmacological uses of each plant. Out of 25 medicinal plants screened for their major classes of phytochemicals, the majority contained tannins, alkaloids and flavonoids. Out of the seven plant species investigated for their biological activities, all seven of them exhibited mild antimicrobial properties, five plants gave significant in vitro antiplasmodial activities, two plants gave moderate anti-Trypanosoma brucei rhodesiense activity, and one plant showed mild cytotoxicity. Meconopsis simplicifolia showed the highest antiplasmodial activity with IC(50) values of 0.40 μg/ml against TM4/8.2 strain (a wild type chloroquine and

Epidemiology of human African trypanosomiasis

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Franco JR

2014-08-01

Full Text Available Jose R Franco,1 Pere P Simarro,1 Abdoulaye Diarra,2 Jean G Jannin1 1World Health Organization, Control of Neglected Tropical Diseases, Innovative and Intensified Disease Management, Geneva, Switzerland; 2World Health Organization, Inter Country Support Team for Central Africa, Regional Office for Africa, Libreville, Gabon Abstract: Human African trypanosomiasis (HAT, or sleeping sickness, is caused by Trypanosoma brucei gambiense, which is a chronic form of the disease present in western and central Africa, and by Trypanosoma brucei rhodesiense, which is an acute disease located in eastern and southern Africa. The rhodesiense form is a zoonosis, with the occasional infection of humans, but in the gambiense form, the human being is regarded as the main reservoir that plays a key role in the transmission cycle of the disease. The gambiense form currently assumes that 98% of the cases are declared; the Democratic Republic of the Congo is the most affected country, with more than 75% of the gambiense cases declared. The epidemiology of the disease is mediated by the interaction of the parasite (trypanosome with the vectors (tsetse flies, as well as with the human and animal hosts within a particular environment. Related to these interactions, the disease is confined in spatially limited areas called “foci”, which are located in Sub-Saharan Africa, mainly in remote rural areas. The risk of contracting HAT is, therefore, determined by the possibility of contact of a human being with an infected tsetse fly. Epidemics of HAT were described at the beginning of the 20th century; intensive activities have been set up to confront the disease, and it was under control in the 1960s, with fewer than 5,000 cases reported in the whole continent. The disease resurged at the end of the 1990s, but renewed efforts from endemic countries, cooperation agencies, and nongovernmental organizations led by the World Health Organization succeeded to raise awareness and

Characterization of Trypanosoma brucei brucei S-adenosyl-L-methionine decarboxylase and its inhibition by Berenil, pentamidine and methylglyoxal bis(guanylhydrazone).

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Bitonti, A J; Dumont, J A; McCann, P P

1986-01-01

Trypanosoma brucei brucei S-adenosyl-L-methionine (AdoMet) decarboxylase was found to be relatively insensitive to activation by putrescine as compared with the mammalian enzyme, being stimulated by only 50% over a 10,000-fold range of putrescine concentrations. The enzyme was not stimulated by up to 10 mM-Mg2+. The Km for AdoMet was 30 microM, similar to that of other eukaryotic AdoMet decarboxylases. T.b. brucei AdoMet decarboxylase activity was apparently irreversibly inhibited in vitro by Berenil and reversibly by pentamidine and methylglyoxal bis(guanylhydrazone). Berenil also inhibited trypanosomal AdoMet decarboxylase by 70% within 4 h after administration to infected rats and markedly increased the concentration of putrescine in trypanosomes that were exposed to the drug in vivo. Spermidine and spermine blocked the curative effect of Berenil on model mouse T.b. brucei infections. This effect of the polyamines was probably not due to reversal of Berenil's inhibitory effects on the AdoMet decarboxylase. PMID:3800910

The flagellum of Trypanosoma brucei: new tricks from an old dog

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Ralston, Katherine S.; Hill, Kent L.

2010-01-01

African trypanosomes, i.e. Trypanosoma brucei and related sub-species, are devastating human and animal pathogens that cause significant human mortality and limit sustained economic development in sub-Saharan Africa. Trypanosoma brucei is a highly motile protozoan parasite and coordinated motility is central to both disease pathogenesis in the mammalian host and parasite development in the tsetse fly vector. Since motility is critical for parasite development and pathogenesis, understanding unique aspects of the T. brucei flagellum may uncover novel targets for therapeutic intervention in African sleeping sickness. Moreover, studies of conserved features of the T. brucei flagellum are directly relevant to understanding fundamental aspects of flagellum and cilium function in other eukaryotes, making T. brucei an important model system. The T. brucei flagellum contains a canonical 9 + 2 axoneme, together with additional features that are unique to kinetoplastids and a few closely-related organisms. Until recently, much of our knowledge of the structure and function of the trypanosome flagellum was based on analogy and inference from other organisms. There has been an explosion in functional studies in T. brucei in recent years, revealing conserved as well as novel and unexpected structural and functional features of the flagellum. Most notably, the flagellum has been found to be an essential organelle, with critical roles in parasite motility, morphogenesis, cell division and immune evasion. This review highlights recent discoveries on the T. brucei flagellum. PMID:18472102

Regulation and spatial organization of PCNA in Trypanosoma brucei

International Nuclear Information System (INIS)

Kaufmann, Doris; Gassen, Alwine; Maiser, Andreas; Leonhardt, Heinrich; Janzen, Christian J.

2012-01-01

Highlights: ► Characterization of the proliferating cell nuclear antigen in Trypanosoma brucei (TbPCNA). ► TbPCNA is a suitable marker to detect replication in T. brucei. ► TbPCNA distribution and regulation is different compared to closely related parasites T. cruzi and Leishmania donovani. -- Abstract: As in most eukaryotic cells, replication is regulated by a conserved group of proteins in the early-diverged parasite Trypanosoma brucei. Only a few components of the replication machinery have been described in this parasite and regulation, sub-nuclear localization and timing of replication are not well understood. We characterized the proliferating cell nuclear antigen in T. brucei (TbPCNA) to establish a spatial and temporal marker for replication. Interestingly, PCNA distribution and regulation is different compared to the closely related parasites Trypanosoma cruzi and Leishmania donovani. TbPCNA foci are clearly detectable during S phase of the cell cycle but in contrast to T. cruzi they are not preferentially located at the nuclear periphery. Furthermore, PCNA seems to be degraded when cells enter G2 phase in T. brucei suggesting different modes of replication regulation or functions of PCNA in these closely related eukaryotes.

Regulation and spatial organization of PCNA in Trypanosoma brucei

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Kaufmann, Doris; Gassen, Alwine [University of Munich (LMU), Department Biology I, Genetics, Grosshaderner Str. 2-4, 82152 Martinsried (Germany); Maiser, Andreas; Leonhardt, Heinrich [University of Munich (LMU), Department Biology II, Grosshaderner Str. 2-4, 82152 Martinsried (Germany); Janzen, Christian J., E-mail: christian.janzen@uni-wuerzburg.de [University of Munich (LMU), Department Biology I, Genetics, Grosshaderner Str. 2-4, 82152 Martinsried (Germany)

2012-03-23

Highlights: Black-Right-Pointing-Pointer Characterization of the proliferating cell nuclear antigen in Trypanosoma brucei (TbPCNA). Black-Right-Pointing-Pointer TbPCNA is a suitable marker to detect replication in T. brucei. Black-Right-Pointing-Pointer TbPCNA distribution and regulation is different compared to closely related parasites T. cruzi and Leishmania donovani. -- Abstract: As in most eukaryotic cells, replication is regulated by a conserved group of proteins in the early-diverged parasite Trypanosoma brucei. Only a few components of the replication machinery have been described in this parasite and regulation, sub-nuclear localization and timing of replication are not well understood. We characterized the proliferating cell nuclear antigen in T. brucei (TbPCNA) to establish a spatial and temporal marker for replication. Interestingly, PCNA distribution and regulation is different compared to the closely related parasites Trypanosoma cruzi and Leishmania donovani. TbPCNA foci are clearly detectable during S phase of the cell cycle but in contrast to T. cruzi they are not preferentially located at the nuclear periphery. Furthermore, PCNA seems to be degraded when cells enter G2 phase in T. brucei suggesting different modes of replication regulation or functions of PCNA in these closely related eukaryotes.

Antiparasitic activities of acridone alkaloids from Swinglea glutinosa (Bl.) Merr

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Santos, Djalma A.P. dos; Vieira, Paulo C; Silva, M. Fatima das G.F. da; Fernandes, Joao B [Universidade Federal de Sao Carlos, SP (Brazil). Dept. de Quimica; Rattray, Lauren; Croft, Simon L [London School of Hygiene and Tropical Medicine, London (United Kingdom). Dept. of Infectious and Tropical Diseases

2009-07-01

Eleven acridone alkaloids isolated from Swinglea glutinosa (Bl.) Merr. were examined for in vitro activity against chloroquine-sensitive Plasmodium falciparum 3D7, Trypanosoma brucei rhodesiense STIB900 and Leishmania donovani L82. An assay with KB cells was developed in order to compare in vitro toxicity of alkaloids with the selective action on the parasites. Nine of the compounds had IC{sub 50} values ranging from 0.3 to 11.6 {mu}M against P. falciparum. In contrast, a small number of compounds showed significant activity against T. brucei rhodesiense and none had activity against L. donovani. Among the alkaloids three had IC{sub 50} < 1.0 {mu}M against P. falciparum, whereas against T. b. rhodesiense five had IC{sub 50} < 10 {mu}M. The characterization of the acridone alkaloids, 1,3,5-trihydroxy-4-methoxy-10-methyl-2,8-bis(3-methylbut-2-enyl)acridin-9 (10H)-one (1), 2,3-dihydro-4,9-dihydroxy-2-(2-hydroxypropan-2-yl)-11-methoxy-10-methylfuro [3,2-b] acridin-5(10H)-one (2) and 3,4-dihydro-3,5,8-trihydroxy-6-methoxy-2,2,7-trimethyl-2Hpyrano[ 2,3-a]acridin-12(7H)-one (3), is discussed, as well as the structure-activity relationship of all compounds assayed. Isolation and spectral data of alkaloids 1-3 are described for the first time although their cytotoxicities to cancer cells have been described before. (author)

Characterization of recombinant Trypanosoma brucei gambiense Translationally Controlled Tumor Protein (rTbgTCTP) and its interaction with Glossina midgut bacteria.

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Bossard, Géraldine; Bartoli, Manon; Fardeau, Marie-Laure; Holzmuller, Philippe; Ollivier, Bernard; Geiger, Anne

2017-09-03

In humans, sleeping sickness (i.e. Human African Trypanosomiasis) is caused by the protozoan parasites Trypanosoma brucei gambiense (Tbg) in West and Central Africa, and T. b. rhodesiense in East Africa. We previously showed in vitro that Tbg is able to excrete/secrete a large number of proteins, including Translationally Controlled Tumor Protein (TCTP). Moreover, the tctp gene was described previously to be expressed in Tbg-infected flies. Aside from its involvement in diverse cellular processes, we have investigated a possible alternative role within the interactions occurring between the trypanosome parasite, its tsetse fly vector, and the associated midgut bacteria. In this context, the Tbg tctp gene was synthesized and cloned into the baculovirus vector pAcGHLT-A, and the corresponding protein was produced using the baculovirus Spodoptera frugicola (strain 9) / insect cell system. The purified recombinant protein rTbgTCTP was incubated together with bacteria isolated from the gut of tsetse flies, and was shown to bind to 24 out of the 39 tested bacteria strains belonging to several genera. Furthermore, it was shown to affect the growth of the majority of these bacteria, especially when cultivated under microaerobiosis and anaerobiosis. Finally, we discuss the potential for TCTP to modulate the fly microbiome composition toward favoring trypanosome survival.

Occurrence, clinical manifestation and the epidemiological implications of naturally occurring canine trypanosomosis in western Kenya

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G.O. Matete

2003-11-01

Full Text Available Domestic dogs were screened for Trypanosoma brucei infection using the haematocrit centrifugation technique as part of routine active surveillance exercises in the Busia and Teso districts of Kenya. The purpose was to assess the role of dogs as sentinels for the occurrence of human sleeping sickness. Out of 200 dogs screened, five were found to be infected at the various test sites. These five succumbed to the disease within four weeks, and exhibited a distinct and pronounced corneal opacity before death. Blood from two naturally infected dogs were tested for the presence of the serum resistance associated (SRA gene and one tested positive, confirming it as human infective (T. brucei rhodesiense prevalence (0.5 %. It is considered that the occurrence of this clinical sign could be used as an early warning prediction of future outbreaks. This type of prediction could form an integral part of an indigenous technical knowledge set in areas lying at the edges of the tsetse (Glossina belts where T. brucei is the main trypanosome species that affects dogs. The occurrence of corneal opacity in dogs could indicate a rise in the levels of T. brucei a proportion of which could be human infective T. b. rhodesiense circulating in the population early enough before disease outbreak occurs. It is thought that during sleeping sickness epidemics the domestic dog will be the first casualty rapidly succumbing to disease long before it is noticed in man. Prompt prediction of disease outbreaks would thus enable early interventions that would reduce the morbidity, mortality and the general economic losses associated with sleeping sickness to be instituted.

Triacylglycerol Storage in Lipid Droplets in Procyclic Trypanosoma brucei.

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Stefan Allmann

Full Text Available Carbon storage is likely to enable adaptation of trypanosomes to nutritional challenges or bottlenecks during their stage development and migration in the tsetse. Lipid droplets are candidates for this function. This report shows that feeding of T. brucei with oleate results in a 4-5 fold increase in the number of lipid droplets, as quantified by confocal fluorescence microscopy and by flow cytometry of BODIPY 493/503-stained cells. The triacylglycerol (TAG content also increased 4-5 fold, and labeled oleate is incorporated into TAG. Fatty acid carbon can thus be stored as TAG in lipid droplets under physiological growth conditions in procyclic T. brucei. β-oxidation has been suggested as a possible catabolic pathway for lipids in T. brucei. A single candidate gene, TFEα1 with coding capacity for a subunit of the trifunctional enzyme complex was identified. TFEα1 is expressed in procyclic T. brucei and present in glycosomal proteomes, Unexpectedly, a TFEα1 gene knock-out mutant still expressed wild-type levels of previously reported NADP-dependent 3-hydroxyacyl-CoA dehydrogenase activity, and therefore, another gene encodes this enzymatic activity. Homozygous Δtfeα1/Δtfeα1 null mutant cells show a normal growth rate and an unchanged glycosomal proteome in procyclic T. brucei. The decay kinetics of accumulated lipid droplets upon oleate withdrawal can be fully accounted for by the dilution effect of cell division in wild-type and Δtfeα1/Δtfeα1 cells. The absence of net catabolism of stored TAG in procyclic T. brucei, even under strictly glucose-free conditions, does not formally exclude a flux through TAG, in which biosynthesis equals catabolism. Also, the possibility remains that TAG catabolism is completely repressed by other carbon sources in culture media or developmentally activated in post-procyclic stages in the tsetse.

Minimum Information Loss Based Multi-kernel Learning for Flagellar Protein Recognition in Trypanosoma Brucei

KAUST Repository

Wang, Jim Jing-Yan

2014-12-01

Trypanosma brucei (T. Brucei) is an important pathogen agent of African trypanosomiasis. The flagellum is an essential and multifunctional organelle of T. Brucei, thus it is very important to recognize the flagellar proteins from T. Brucei proteins for the purposes of both biological research and drug design. In this paper, we investigate computationally recognizing flagellar proteins in T. Brucei by pattern recognition methods. It is argued that an optimal decision function can be obtained as the difference of probability functions of flagella protein and the non-flagellar protein for the purpose of flagella protein recognition. We propose to learn a multi-kernel classification function to approximate this optimal decision function, by minimizing the information loss of such approximation which is measured by the Kull back-Leibler (KL) divergence. An iterative multi-kernel classifier learning algorithm is developed to minimize the KL divergence for the problem of T. Brucei flagella protein recognition, experiments show its advantage over other T. Brucei flagellar protein recognition and multi-kernel learning methods. © 2014 IEEE.

In vivo trypanocidal activity of Nymphaea lotus Linn. methanol extract against Trypanosoma brucei brucei

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Muhammad Haruna Garba

2015-10-01

Full Text Available Objective: To evaluate the antitrypanosomal potentials of methanol extract of Nymphaea lotus Linn. (N. lotus with the aim of obtaining a new lead for formulating safe, inexpensive, nontoxic and readily available trypanocidal drugs. Methods: Seventy percent (v/v (methanol/water crude extract of N. lotus was evaluated for antitrypanosomal activity in experimental trypanosomiasis using Trypanosoma brucei bruceiinfected mice. Infected mice in different groups were administered intraperitoneally 100, 200, 300 and 400 mg/kg body weight/day of the crude for two weeks, while a positive control group was treated with standard drug, berenil. Results: The crude extract at a dose of 100 mg/kg body weight/day was more effective than the higher doses in completely clearing parasites from the blood of mice infected with Trypanosoma brucei brucei. Pre-treatment of healthy mice with the crude extract for 5 days before infection did not prevent the establishment of the infection, indicating that the extract had no prophylactic activity. Subinoculation of the blood and cerebrospinal fluid drawn from the cured mice into healthy mice failed to produce any infection within 50 days post inoculation. Administration of 1 000 mg/kg body weight of the crude extract led to the death of 50% of the experimental animals indicating a high level of toxicity of the extract at higher doses. Conclusions: This study has demonstrated the potency of the crude extract of N. lotus in treating experimental trypanosomiasis at lower doses.

Characterisation of the wildlife reservoir community for human and animal trypanosomiasis in the Luangwa Valley, Zambia.

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Neil E Anderson

2011-06-01

Full Text Available Animal and human trypanosomiasis are constraints to both animal and human health in Sub-Saharan Africa, but there is little recent evidence as to how these parasites circulate in wild hosts in natural ecosystems. The Luangwa Valley in Zambia supports high densities of tsetse flies (Glossina species and is recognised as an historical sleeping sickness focus. The objective of this study was to characterise the nature of the reservoir community for trypanosomiasis in the absence of influence from domesticated hosts.A cross-sectional survey of trypanosome prevalence in wildlife hosts was conducted in the Luangwa Valley from 2005 to 2007. Samples were collected from 418 animals and were examined for the presence of Trypanosoma brucei s.l., T. b. rhodesiense, Trypanosoma congolense and Trypanosoma vivax using molecular diagnostic techniques. The overall prevalence of infection in all species was 13.9% (95% confidence interval [CI]: 10.71-17.57%. Infection was significantly more likely to be detected in waterbuck (Kobus ellipsiprymnus (Odds ratio [OR]=10.5, 95% CI: 2.36-46.71, lion (Panthera leo (OR=5.3, 95% CI: 1.40-19.69, greater kudu (Tragelaphus strepsiceros (OR=4.7, 95% CI: 1.41-15.41 and bushbuck (Tragelaphus scriptus (OR=4.5, 95% CI: 1.51-13.56. Bushbucks are important hosts for T. brucei s.l. while the Bovidae appear the most important for T. congolense. The epidemiology of T. vivax was less clear, but parasites were detected most frequently in waterbuck. Human infective T. b. rhodesiense were identified for the first time in African buffalo (Syncerus caffer and T. brucei s.l. in leopard (Panthera pardus. Variation in infection rates was demonstrated at species level rather than at family or sub-family level. A number of significant risk factors interact to influence infection rates in wildlife including taxonomy, habitat and blood meal preference.Trypanosoma parasites circulate within a wide and diverse host community in this bio

Phenolic Constituents of Medicinal Plants with Activity against Trypanosoma brucei

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Ya Nan Sun

2016-04-01

Full Text Available Neglected tropical diseases (NTDs affect over one billion people all over the world. These diseases are classified as neglected because they impact populations in areas with poor financial conditions and hence do not attract sufficient research investment. Human African Trypanosomiasis (HAT or sleeping sickness, caused by the parasite Trypanosoma brucei, is one of the NTDs. The current therapeutic interventions for T. brucei infections often have toxic side effects or require hospitalization so that they are not available in the rural environments where HAT occurs. Furthermore, parasite resistance is increasing, so that there is an urgent need to identify novel lead compounds against this infection. Recognizing the wide structural diversity of natural products, we desired to explore and identify novel antitrypanosomal chemotypes from a collection of natural products obtained from plants. In this study, 440 pure compounds from various medicinal plants were tested against T. brucei by in a screening using whole cell in vitro assays. As the result, twenty-two phenolic compounds exhibited potent activity against cultures of T. brucei. Among them, eight compounds—4, 7, 11, 14, 15, 18, 20, and 21—showed inhibitory activity against T. brucei, with IC50 values below 5 µM, ranging from 0.52 to 4.70 μM. Based on these results, we attempt to establish some general trends with respect to structure-activity relationships, which indicate that further investigation and optimization of these derivatives might enable the preparation of potentially useful compounds for treating HAT.

Studies on the glycosome of Trypanosoma brucei

International Nuclear Information System (INIS)

Aman, R.A.

1985-01-01

Glycosomes (microbodies) have been purified from bloodstream form Trypanosoma brucei by an improved procedure involving freezing and thawing live organisms in 15% glycerol prior to cell disruption. Highly purified organelles of bloodstream form T. brucei contain 11 major proteins of which 8 tentatively identified glycolytic enzymes make up about 90% of the total glycosomal protein. Treatment of these intact isolated organelles with the bisimidoester dimethylsuberimidate (DMSI) resulted in crosslinking of all glycosomal proteins into a large complex suggestive of juxtapositioning of the glycosomal proteins. The crosslinked complex was capable of catalyzing the multienzyme conversion of glucose to glycerol-3-phosphate but did not possess any special kinetic features different from those of the unaggregated enzymes represented by solubilized glycosomes. The multienzyme reaction had a lab phase associated with it and [ 14 C]-glucose label incorporation into sugar phosphate intermediates was effectively competed by unlabeled intermediates. Glycosomes were also purified from culture form T. brucei by several different procedures. Comparison of highly purified organelles from the two different life stages of the organism showed reduced specific activities and contents of the early glycolytic enzymes in organelles from the culture form with a decrease from 87% to 35% of the contribution of glycolytic enzymes to the total glycosomal protein

Neural Damage in Experimental Trypanosoma brucei gambiense Infection: The Suprachiasmatic Nucleus

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Chiara Tesoriero

2018-02-01

Full Text Available Trypanosoma brucei (T. b. gambiense is the parasite subspecies responsible for most reported cases of human African trypanosomiasis (HAT or sleeping sickness. This severe infection leads to characteristic disruption of the sleep-wake cycle, recalling attention on the circadian timing system. Most animal models of the disease have been hitherto based on infection of laboratory rodents with the T. b. brucei subspecies, which is not infectious to humans. In these animal models, functional, rather than structural, alterations of the master circadian pacemaker, the hypothalamic suprachiasmatic nucleus (SCN, have been reported. Information on the SCN after infection with the human pathogenic T. b. gambiense is instead lacking. The present study was aimed at the examination of the SCN after T. b. gambiense infection of a susceptible rodent, the multimammate mouse, Mastomys natalensis, compared with T. b. brucei infection of the same host species. The animals were examined at 4 and 8 weeks post-infection, when parasites (T. b. gambiense or T. b. brucei were detected in the brain parenchyma, indicating that the disease was in the encephalitic stage. Neuron and astrocyte changes were examined with Nissl staining, immunophenotyping and quantitative analyses. Interestingly, significant neuronal loss (about 30% reduction was documented in the SCN during the progression of T. b. gambiense infection. No significant neuronal density changes were found in the SCN of T. b. brucei-infected animals. Neuronal cell counts in the hippocampal dentate gyrus of T. b. gambiense-infected M. natalensis did not point out significant changes, indicating that no widespread neuron loss had occurred in the brain. Marked activation of astrocytes was detected in the SCN after both T. b. gambiense and T. b. brucei infections. Altogether the findings reveal that neurons of the biological clock are highly susceptible to the infection caused by human pathogenic African trypanosomes

Evaluation of In Vitro Activity of Essential Oils against Trypanosoma brucei brucei and Trypanosoma evansi

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Nathan Habila

2010-01-01

Full Text Available Essential oils (EOs from Cymbopogon citratus (CC, Eucalyptus citriodora (EC, Eucalyptus camaldulensis (ED, and Citrus sinensis (CS were obtained by hydrodistillation process. The EOs were evaluated in vitro for activity against Trypanosoma brucei brucei (Tbb and Trypanosoma evansi (T. evansi. The EOs were found to possess antitrypanosomal activity in vitro in a dose-dependent pattern in a short period of time. The drop in number of parasite over time was achieved doses of 0.4 g/ml, 0.2 g/mL, and 0.1 g/mL for all the EOs. The concentration of 0.4 g/mL CC was more potent at 3 minutes and 2 minutes for Tbb and T. evansi, respectively. The GC-MS analysis of the EOs revealed presence of Cyclobutane (96.09% in CS, 6-octenal (77.11% in EC, Eucalyptol (75% in ED, and Citral (38.32% in CC among several other organic compounds. The results are discussed in relation to trypanosome chemotherapy.

Human and animal Trypanosomes in Côte d'Ivoire form a single breeding population.

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Paul Capewell

Full Text Available Trypanosoma brucei is the causative agent of African Sleeping Sickness in humans and contributes to the related veterinary disease, Nagana. T. brucei is segregated into three subspecies based on host specificity, geography and pathology. T. b. brucei is limited to animals (excluding some primates throughout sub-Saharan Africa and is non-infective to humans due to trypanolytic factors found in human serum. T. b. gambiense and T. b. rhodesiense are human infective sub-species. T. b. gambiense is the more prevalent human, causing over 97% of human cases. Study of T. b. gambiense is complicated in that there are two distinct groups delineated by genetics and phenotype. The relationships between the two groups and local T. b. brucei are unclear and may have a bearing on the evolution of the human infectivity traits.A collection of sympatric T. brucei isolates from Côte d'Ivoire, consisting of T. b. brucei and both groups of T. b. gambiense have previously been categorized by isoenzymes, RFLPs and Blood Incubation Infectivity Tests. These samples were further characterized using the group 1 specific marker, TgSGP, and seven microsatellites. The relationships between the T. b. brucei and T. b. gambiense isolates were determined using principal components analysis, neighbor-joining phylogenetics, STRUCTURE, FST, Hardy-Weinberg equilibrium and linkage disequilibrium.Group 1 T. b. gambiense form a clonal genetic group, distinct from group 2 and T. b. brucei, whereas group 2 T. b. gambiense are genetically indistinguishable from local T. b. brucei. There is strong evidence for mating within and between group 2 T. b. gambiense and T. b. brucei. We found no evidence to support the hypothesis that group 2 T. b. gambiense are hybrids of group 1 and T. b. brucei, suggesting that human infectivity has evolved independently in groups 1 and 2 T. b. gambiense.

Discovery and Evaluation of Thiazinoquinones as Anti-Protozoal Agents

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Marcel Kaiser

2013-09-01

Full Text Available Pure compound screening has identified the dioxothiazino-quinoline-quinone ascidian metabolite ascidiathiazone A (2 to be a moderate growth inhibitor of Trypanosoma brucei rhodesiense (IC50 3.1 μM and Plasmodium falciparum (K1 dual drug resistant strain (IC50 3.3 μM while exhibiting low levels of cytotoxicity (L6, IC50 167 μM. A series of C-7 amide and Δ2(3 analogues were prepared that explored the influence of lipophilicity and oxidation state on observed anti-protozoal activity and selectivity. Little variation in anti-malarial potency was observed (IC50 0.62–6.5 μM, and no correlation was apparent between anti-malarial and anti-T. brucei activity. Phenethylamide 7e and Δ2(3-glycine analogue 8k exhibited similar anti-Pf activity to 2 but with slightly enhanced selectivity (SI 72 and 93, respectively, while Δ2(3-phenethylamide 8e (IC50 0.67 μM, SI 78 exhibited improved potency and selectivity towards T. brucei rhodesiense compared to the natural product hit. A second series of analogues were prepared that replaced the quinoline ring of 2 with benzofuran or benzothiophene moieties. While esters 10a/10b and 15 were once again found to exhibit cytotoxicity, carboxylic acid analogues exhibited potent anti-Pf activity (IC50 0.34–0.035 μM combined with excellent selectivity (SI 560–4000. In vivo evaluation of a furan carboxylic acid analogue against P. berghei was undertaken, demonstrating 85.7% and 47% reductions in parasitaemia with ip or oral dosing respectively.

The Oral Antimalarial Drug Tafenoquine Shows Activity against Trypanosoma brucei.

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Carvalho, Luis; Martínez-García, Marta; Pérez-Victoria, Ignacio; Manzano, José Ignacio; Yardley, Vanessa; Gamarro, Francisco; Pérez-Victoria, José M

2015-10-01

The protozoan parasite Trypanosoma brucei causes human African trypanosomiasis, or sleeping sickness, a neglected tropical disease that requires new, safer, and more effective treatments. Repurposing oral drugs could reduce both the time and cost involved in sleeping sickness drug discovery. Tafenoquine (TFQ) is an oral antimalarial drug belonging to the 8-aminoquinoline family which is currently in clinical phase III. We show here that TFQ efficiently kills different T. brucei spp. in the submicromolar concentration range. Our results suggest that TFQ accumulates into acidic compartments and induces a necrotic process involving cell membrane disintegration and loss of cytoplasmic content, leading to parasite death. Cell lysis is preceded by a wide and multitarget drug action, affecting the lysosome, mitochondria, and acidocalcisomes and inducing a depolarization of the mitochondrial membrane potential, elevation of intracellular Ca(2+), and production of reactive oxygen species. This is the first report of an 8-aminoquinoline demonstrating significant in vitro activity against T. brucei. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Estimating the economic and social consequences for patients diagnosed with human African trypanosomiasis in Muchinga, Lusaka and Eastern Provinces of Zambia (2004–2014)

OpenAIRE

Mwiinde, Allan Mayaba; Simuunza, Martin; Namangala, Boniface; Chama-Chiliba, Chitalu Miriam; Machila, Noreen; Anderson, Neil; Shaw, Alexandra; Welburn, Susan C.

2017-01-01

Background Acute human African trypanosomiasis (rHAT) caused by Trypanosoma brucei rhodesiense is associated with high mortality and is fatal if left untreated. Only a few studies have examined the psychological, social and economic impacts of rHAT. In this study, mixed qualitative and quantitative research methods were used to evaluate the socio-economic impacts of rHAT in Mambwe, Rufunsa, Mpika and Chama Districts of Zambia. Methods Individuals diagnosed with rHAT from 2004 to 2014 were tra...

Structure-activity relationship study of sesquiterpene lactones and their semi-synthetic amino derivatives as potential antitrypanosomal products

CSIR Research Space (South Africa)

Zimmermann, S

2014-03-01

Full Text Available Stefanie Zimmermann 1,2, Gerda Fouché 3, Maria De Mieri 1, Yukiko Yoshimoto 4, Toyonobu Usuki 4, Rudzani Nthambeleni 3, Christopher J. Parkinson 5, Christiaan van der Westhuyzen 3, Marcel Kaiser 2,6, Matthias Hamburger 1 and Michael Adams 1,* 1... 1. Introduction Sleeping sickness, or human African trypanosomiasis (HAT), is a deadly protozoal disease caused by Trypanosoma brucei species spread by tsetse flies (Glossina spp.). The two human pathogenic subspecies, T. b. rhodesiense (95...

Antitrypanosomal effect of methanolic extract of Zingiber officinale (ginger on Trypanosoma brucei brucei-infected Wistar mice

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P. I. Kobo

2014-10-01

Full Text Available Aim: The study was carried out to determine the in vivo antitrypanosomal effect of methanolic extract of Zingiber officinale (ginger in Trypanosoma brucei brucei-infected mice. Materials and Methods: Twenty-five mice were randomly allocated into five groups of five animals each. Group I and II were given Tween 80 (1 ml/kg and diminazene aceturate (3.5 mg/kg to serve as untreated and treated controls, respectively. Groups III-V received the extract at 200, 400 and 800 mg/kg body weight, respectively. All treatments were given for 6 consecutive days and through the oral route. The mean body weight, mean survival period and daily level of parasitaemia were evaluated. Results: Acute toxicity showed the extract to be relatively safe. There was an insignificant increase in body weight and survival rate of mice treated with the extract. The level of parasitaemia in the extract treated groups was decreased. Conclusion: This study shows the in vivo potential of methanolic extract of Z. officinale in the treatment of trypanosomiasis.

Intraclonal mating occurs during tsetse transmission of Trypanosoma brucei

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Ferris Vanessa

2009-09-01

Full Text Available Abstract Background Mating in Trypanosoma brucei is a non-obligatory event, triggered by the co-occurrence of different strains in the salivary glands of the vector. Recombinants that result from intra- rather than interclonal mating have been detected, but only in crosses of two different trypanosome strains. This has led to the hypothesis that when trypanosomes recognize a different strain, they release a diffusible factor or pheromone that triggers mating in any cell in the vicinity whether it is of the same or a different strain. This idea assumes that the trypanosome can recognize self and non-self, although there is as yet no evidence for the existence of mating types in T. brucei. Results We investigated intraclonal mating in T. b. brucei by crossing red and green fluorescent lines of a single strain, so that recombinant progeny can be detected in the fly by yellow fluorescence. For strain 1738, seven flies had both red and green trypanosomes in the salivary glands and, in three, yellow trypanosomes were also observed, although they could not be recovered for subsequent analysis. Nonetheless, both red and non-fluorescent clones from these flies had recombinant genotypes as judged by microsatellite and karyotype analyses, and some also had raised DNA contents, suggesting recombination or genome duplication. Strain J10 produced similar results indicative of intraclonal mating. In contrast, trypanosome clones recovered from other flies showed that genotypes can be transmitted with fidelity. When a yellow hybrid clone expressing both red and green fluorescent protein genes was transmitted, the salivary glands contained a mixture of fluorescent-coloured trypanosomes, but only yellow and red clones were recovered. While loss of the GFP gene in the red clones could have resulted from gene conversion, some of these clones showed loss of heterozygosity and raised DNA contents as in the other single strain transmissions. Our observations suggest

Antitrypanosomal isothiocyanate and thiocarbamate glycosides from Moringa peregrina.

Science.gov (United States)

Ayyari, Mahdi; Salehi, Peyman; Ebrahimi, Samad Nejad; Zimmermann, Stefanie; Portmann, Lena; Krauth-Siegel, R Luise; Kaiser, Marcel; Brun, Reto; Rezadoost, Hassan; Rezazadeh, Shamsali; Hamburger, Matthias

2014-01-01

O-Methyl (1), O-ethyl (2), and O-butyl (3) 4-[(α-L-rhamnosyloxy) benzyl] thiocarbamate (E), along with 4-(α-L-rhamnosyloxy) benzyl isothiocyanate (4) have been isolated from the aerial parts of Moringa peregrina. The compounds were tested for in vitro activity against Trypanosoma brucei rhodesiense and cytotoxicity in rat skeletal myoblasts (L6 cells). The most potent compound was 4 with an IC50 of 0.10 µM against T.b. rhodesiense and a selectivity index of 73, while the thiocarbamate glycosides 1, 2, and 3 showed only moderate activity. Intraperitoneal administration of 50 mg/kg body weight/day of 4 in the T.b. rhodesiense STIB 900 acute mouse model revealed significant in vivo toxicity. Administration of 10 mg/kg body weight/day resulted in a 95% reduction of parasitemia on day 7 postinfection, but did not cure the animals. Because of its high in vitro activity and its ability to irreversibly inhibit trypanothione reductase, an attractive parasite-specific target enzyme, 4-[(α-L-rhamnosyloxy) benzyl] isothiocyanate (4), can be considered as a lead structure for the development and characterization of novel antitrypanosomal drugs. Georg Thieme Verlag KG Stuttgart · New York.

Interaction between Trypanosoma brucei and Haemonchus ...

African Journals Online (AJOL)

In order to investigate the immunomodulatory influence of concurrent T. brucei and H. contortus infection in West African Dwarf (WAD) goats, 28 infected and 7 uninfected (control) of 8-9 months old male WAD goats were studied. The infected goats were separated into resistant (Class 1) and susceptible (Class 2) Faecal ...

Characterization of Trypanosoma brucei gambiense stocks isolated ...

African Journals Online (AJOL)

Trypanosoma brucei gambiense was isolated twice from each of 23 patients in Côte d'Ivoire. Genetic characterization using RAPD (Random Primed Amplified Polymorphic DNA) showed additional variability within a given isoenzyme profile (zymodeme), confirming that this fingerprinting method has a higher discriminative ...

Stearoyl-CoA desaturase is an essential enzyme for the parasitic protist Trypanosoma brucei

Energy Technology Data Exchange (ETDEWEB)

Alloatti, Andres [Instituto de Biologia Molecular y Celular de Rosario (IBR), CONICET, Facultad de Ciencias Bioquimicas y Farmaceuticas, Universidad Nacional de Rosario, Santa Fe (Argentina); Gupta, Shreedhara; Gualdron-Lopez, Melisa; Nguewa, Paul A. [Research Unit for Tropical Diseases, de Duve Institute and Laboratory of Biochemistry, Universite Catholique de Louvain, Brussels (Belgium); Altabe, Silvia G. [Instituto de Biologia Molecular y Celular de Rosario (IBR), CONICET, Facultad de Ciencias Bioquimicas y Farmaceuticas, Universidad Nacional de Rosario, Santa Fe (Argentina); Deumer, Gladys; Wallemacq, Pierre [Department of Clinical Chemistry, Cliniques Universitaires Saint-Luc, LTAP, Universite Catholique de Louvain, Brussels (Belgium); Michels, Paul A.M. [Research Unit for Tropical Diseases, de Duve Institute and Laboratory of Biochemistry, Universite Catholique de Louvain, Brussels (Belgium); Uttaro, Antonio D., E-mail: toniuttaro@yahoo.com.ar [Instituto de Biologia Molecular y Celular de Rosario (IBR), CONICET, Facultad de Ciencias Bioquimicas y Farmaceuticas, Universidad Nacional de Rosario, Santa Fe (Argentina)

2011-08-26

Highlights: {yields} Inhibiting {Delta}9 desaturase drastically changes T. brucei's fatty-acid composition. {yields} Isoxyl specifically inhibits the {Delta}9 desaturase causing a growth arrest. {yields} RNA interference of desaturase expression causes a similar effect. {yields} Feeding T. brucei-infected mice with Isoxyl decreases the parasitemia. {yields} 70% of Isoxyl-treated mice survived the trypanosome infection. -- Abstract: Trypanosoma brucei, the etiologic agent of sleeping sickness, is exposed to important changes in nutrients and temperature during its life cycle. To adapt to these changes, the fluidity of its membranes plays a crucial role. This fluidity, mediated by the fatty-acid composition, is regulated by enzymes named desaturases. We have previously shown that the oleoyl desaturase is essential for Trypanosoma cruzi and T. brucei. In this work, we present experimental support for the relevance of stearoyl-CoA desaturase (SCD) for T. brucei's survival, in both its insect or procyclic-form (PCF) and bloodstream-form (BSF) stages. We evaluated this essentiality in two different ways: by generating a SCD knocked-down parasite line using RNA interference, and by chemical inhibition of the enzyme with two compounds, Isoxyl and a thiastearate with the sulfur atom at position 10 (10-TS). The effective concentration for 50% growth inhibition (EC{sub 50}) of PCF was 1.0 {+-} 0.2 {mu}M for Isoxyl and 5 {+-} 2 {mu}M for 10-TS, whereas BSF appeared more susceptible with EC{sub 50} values 0.10 {+-} 0.03 {mu}M (Isoxyl) and 1.0 {+-} 0.6 {mu}M (10-TS). RNA interference showed to be deleterious for both stages of the parasite. In addition, T. brucei-infected mice were fed with Isoxyl, causing a reduction of the parasitemia and an increase of the rodents' survival.

Stearoyl-CoA desaturase is an essential enzyme for the parasitic protist Trypanosoma brucei

International Nuclear Information System (INIS)

Alloatti, Andres; Gupta, Shreedhara; Gualdron-Lopez, Melisa; Nguewa, Paul A.; Altabe, Silvia G.; Deumer, Gladys; Wallemacq, Pierre; Michels, Paul A.M.; Uttaro, Antonio D.

2011-01-01

Highlights: → Inhibiting Δ9 desaturase drastically changes T. brucei's fatty-acid composition. → Isoxyl specifically inhibits the Δ9 desaturase causing a growth arrest. → RNA interference of desaturase expression causes a similar effect. → Feeding T. brucei-infected mice with Isoxyl decreases the parasitemia. → 70% of Isoxyl-treated mice survived the trypanosome infection. -- Abstract: Trypanosoma brucei, the etiologic agent of sleeping sickness, is exposed to important changes in nutrients and temperature during its life cycle. To adapt to these changes, the fluidity of its membranes plays a crucial role. This fluidity, mediated by the fatty-acid composition, is regulated by enzymes named desaturases. We have previously shown that the oleoyl desaturase is essential for Trypanosoma cruzi and T. brucei. In this work, we present experimental support for the relevance of stearoyl-CoA desaturase (SCD) for T. brucei's survival, in both its insect or procyclic-form (PCF) and bloodstream-form (BSF) stages. We evaluated this essentiality in two different ways: by generating a SCD knocked-down parasite line using RNA interference, and by chemical inhibition of the enzyme with two compounds, Isoxyl and a thiastearate with the sulfur atom at position 10 (10-TS). The effective concentration for 50% growth inhibition (EC 50 ) of PCF was 1.0 ± 0.2 μM for Isoxyl and 5 ± 2 μM for 10-TS, whereas BSF appeared more susceptible with EC 50 values 0.10 ± 0.03 μM (Isoxyl) and 1.0 ± 0.6 μM (10-TS). RNA interference showed to be deleterious for both stages of the parasite. In addition, T. brucei-infected mice were fed with Isoxyl, causing a reduction of the parasitemia and an increase of the rodents' survival.

Deciphering RNA Regulatory Elements Involved in the Developmental and Environmental Gene Regulation of Trypanosoma brucei.

Science.gov (United States)

Gazestani, Vahid H; Salavati, Reza

2015-01-01

Trypanosoma brucei is a vector-borne parasite with intricate life cycle that can cause serious diseases in humans and animals. This pathogen relies on fine regulation of gene expression to respond and adapt to variable environments, with implications in transmission and infectivity. However, the involved regulatory elements and their mechanisms of actions are largely unknown. Here, benefiting from a new graph-based approach for finding functional regulatory elements in RNA (GRAFFER), we have predicted 88 new RNA regulatory elements that are potentially involved in the gene regulatory network of T. brucei. We show that many of these newly predicted elements are responsive to both transcriptomic and proteomic changes during the life cycle of the parasite. Moreover, we found that 11 of predicted elements strikingly resemble previously identified regulatory elements for the parasite. Additionally, comparison with previously predicted motifs on T. brucei suggested the superior performance of our approach based on the current limited knowledge of regulatory elements in T. brucei.

Trypanosoma brucei mitochondrial respiratome: Composition and organization in procyclic form

KAUST Repository

Acestor, Nathalie

2011-05-24

The mitochondrial respiratory chain is comprised of four different protein complexes (I-IV), which are responsible for electron transport and generation of proton gradient in the mitochondrial intermembrane space. This proton gradient is then used by F oF 1-ATP synthase (complex V) to produce ATP by oxidative phosphorylation. In this study, the respiratory complexes I, II, and III were affinity purified from Trypanosoma brucei procyclic form cells and their composition was determined by mass spectrometry. The results along with those that we previously reported for complexes IV and V showed that the respiratome of Trypanosoma is divergent because many of its proteins are unique to this group of organisms. The studies also identified two mitochondrial subunit proteins of respiratory complex IV that are encoded by edited RNAs. Proteomics data from analyses of complexes purified using numerous tagged component proteins in each of the five complexes were used to generate the first predicted protein-protein interaction network of the Trypanosoma brucei respiratory chain. These results provide the first comprehensive insight into the unique composition of the respiratory complexes in Trypanosoma brucei, an early diverged eukaryotic pathogen. © 2011 by The American Society for Biochemistry and Molecular Biology, Inc.

Haematological indices in Trypanosoma brucei brucei (Federe isolate infected Nigerian donkeys (Equus asinus treated with homidium and isometamidium chloride of ciprofloxacin in broiler chickens after single intravenous and intraingluvial administration

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Queen Nneka Oparah

2017-03-01

Full Text Available The efficacy of intramuscular administration of Homidium chloride (Novidium® and Isometamidium chloride (Sécuridium® in Nigerian donkeys (Equus asinus experimentally infected with T. b. brucei (Federe isolate was investigated. Changes in haematological and serum biochemical indices were evaluated using clinical haematology and biochemistry methods. Red blood cell (RBC count for the negative control group was significantly higher than for the positive control, Novidium® and Sécuridium®-treatment groups. Haemoglobin (Hb concentration significantly reduced in the infected untreated group compared with other groups. Packed cell volume (PCV was significantly different between negative and positive controls, and also between the infected untreated and treatment groups. There was significant reduction in platelet counts post-infection and post-treatment. Mean corpuscular volume (MCV increased significantly in the treatment groups while mean corpuscular haemoglobin concentration (MCHC significantly reduced only in the Sécuridium®-treatment group. Lymphocyte count for infected untreated was non-significantly higher than for the uninfected controls, but treatment with both trypanocides recorded further increases, which were higher compared with that of the uninfected group. Post infection and treatment, aspartate aminotransferase (AST levels increased significantly. There were non-significant differences in electrolyte ion concentrations across the groups except for chloride ion which recorded a significant reduction in the Novidium®-treatment group. This experiment revealed that Nigerian donkeys infected with T. brucei brucei (Federe isolate developed symptoms of trypanosomosis; anaemia, lymphocytosis and thrombocytopenia. Treatment with the trypanocides ameliorated effects of the infection, and results suggest that immunosuppression may not be a substantial clinical manifestation of T. brucei brucei (Federe isolate trypanosomosis in Nigerian

Crystal structure of arginine methyltransferase 6 from Trypanosoma brucei.

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Chongyuan Wang

Full Text Available Arginine methylation plays vital roles in the cellular functions of the protozoan Trypanosoma brucei. The T. brucei arginine methyltransferase 6 (TbPRMT6 is a type I arginine methyltransferase homologous to human PRMT6. In this study, we report the crystal structures of apo-TbPRMT6 and its complex with the reaction product S-adenosyl-homocysteine (SAH. The structure of apo-TbPRMT6 displays several features that are different from those of type I PRMTs that were structurally characterized previously, including four stretches of insertion, the absence of strand β15, and a distinct dimerization arm. The comparison of the apo-TbPRMT6 and SAH-TbPRMT6 structures revealed the fine rearrangements in the active site upon SAH binding. The isothermal titration calorimetry results demonstrated that SAH binding greatly increases the affinity of TbPRMT6 to a substrate peptide derived from bovine histone H4. The western blotting and mass spectrometry results revealed that TbPRMT6 methylates bovine histone H4 tail at arginine 3 but cannot methylate several T. brucei histone tails. In summary, our results highlight the structural differences between TbPRMT6 and other type I PRMTs and reveal that the active site rearrangement upon SAH binding is important for the substrate binding of TbPRMT6.

Role of cytokines in Trypanosoma brucei-induced anaemia: A ...

African Journals Online (AJOL)

species Trypanosoma brucei that are transmitted by a tsetse fly (Glossina spp.) ... of autologous immunoglobulin antibodies on the red cell surfaces and also to ... development for the detection and management of anaemia in trypanosomiasis.

Malleable Mitochondrion of Trypanosoma brucei

Czech Academy of Sciences Publication Activity Database

Verner, Zdeněk; Basu, Somsuvro; Benz, C.; Dixit, S.; Dobáková, Eva; Faktorová, Drahomíra; Hashimi, Hassan; Horáková, Eva; Huang, Zhenqiu; Paris, Zdeněk; Peña-Diaz, Priscila; Ridlon, L.; Týč, Jiří; Wildridge, David; Zíková, Alena; Lukeš, Julius

2015-01-01

Roč. 315, 2015 Feb 07 (2015), s. 73-151 ISSN 1937-6448 R&D Projects: GA ČR GAP302/12/2513; GA MŠk LL1205; GA MŠk(CZ) EE2.3.30.0032; GA MŠk LH12104; GA ČR GAP305/12/2261 EU Projects: European Commission(XE) 316304 Institutional support: RVO:60077344 Keywords : Kinetoplast * Metabolism * Mitochondrial transport * Mitochondrion * RNA import * T. brucei * Trypanosome * kDNA Subject RIV: EE - Microbiology, Virology Impact factor: 3.752, year: 2015

What controls glycolysis in bloodstream form Trypanosoma brucei?

NARCIS (Netherlands)

Bakker, B.M.; Michels, P.A.M.; Opperdoes, F.R.; Westerhoff, H.V.

1999-01-01

On the basis of the experimentally determined kinetic properties of the trypanosomal enzymes, the question is addressed of which step limits the glycolytic flux in bloodstream form Trypanosoma brucei. There appeared to be no single answer; in the physiological range, control shifted between the

Interactions among Trypanosoma brucei RAD51 paralogues in DNA repair and antigenic variation

Science.gov (United States)

Dobson, Rachel; Stockdale, Christopher; Lapsley, Craig; Wilkes, Jonathan; McCulloch, Richard

2011-01-01

Homologous recombination in Trypanosoma brucei is used for moving variant surface glycoprotein (VSG) genes into expression sites during immune evasion by antigenic variation. A major route for such VSG switching is gene conversion reactions in which RAD51, a universally conserved recombinase, catalyses homology-directed strand exchange. In any eukaryote, RAD51-directed strand exchange in vivo is mediated by further factors, including RAD51-related proteins termed Rad51 paralogues. These appear to be ubiquitously conserved, although their detailed roles in recombination remain unclear. In T. brucei, four putative RAD51 paralogue genes have been identified by sequence homology. Here we show that all four RAD51 paralogues act in DNA repair, recombination and RAD51 subnuclear dynamics, though not equivalently, while mutation of only one RAD51 paralogue gene significantly impedes VSG switching. We also show that the T. brucei RAD51 paralogues interact, and that the complexes they form may explain the distinct phenotypes of the mutants as well as observed expression interdependency. Finally, we document the Rad51 paralogues that are encoded by a wide range of protists, demonstrating that the Rad51 paralogue repertoire in T. brucei is unusually large among microbial eukaryotes and that one member of the protein family corresponds with a key, conserved eukaryotic Rad51 paralogue. PMID:21615552

Targeting the HSP60/10 chaperonin systems of Trypanosoma brucei as a strategy for treating African sleeping sickness.

Science.gov (United States)

Abdeen, Sanofar; Salim, Nilshad; Mammadova, Najiba; Summers, Corey M; Goldsmith-Pestana, Karen; McMahon-Pratt, Diane; Schultz, Peter G; Horwich, Arthur L; Chapman, Eli; Johnson, Steven M

2016-11-01

Trypanosoma brucei are protozoan parasites that cause African sleeping sickness in humans (also known as Human African Trypanosomiasis-HAT). Without treatment, T. brucei infections are fatal. There is an urgent need for new therapeutic strategies as current drugs are toxic, have complex treatment regimens, and are becoming less effective owing to rising antibiotic resistance in parasites. We hypothesize that targeting the HSP60/10 chaperonin systems in T. brucei is a viable anti-trypanosomal strategy as parasites rely on these stress response elements for their development and survival. We recently discovered several hundred inhibitors of the prototypical HSP60/10 chaperonin system from Escherichia coli, termed GroEL/ES. One of the most potent GroEL/ES inhibitors we discovered was compound 1. While examining the PubChem database, we found that a related analog, 2e-p, exhibited cytotoxicity to Leishmania major promastigotes, which are trypanosomatids highly related to Trypanosoma brucei. Through initial counter-screening, we found that compounds 1 and 2e-p were also cytotoxic to Trypanosoma brucei parasites (EC 50 =7.9 and 3.1μM, respectively). These encouraging initial results prompted us to develop a library of inhibitor analogs and examine their anti-parasitic potential in vitro. Of the 49 new chaperonin inhibitors developed, 39% exhibit greater cytotoxicity to T. brucei parasites than parent compound 1. While many analogs exhibit moderate cytotoxicity to human liver and kidney cells, we identified molecular substructures to pursue for further medicinal chemistry optimization to increase the therapeutic windows of this novel class of chaperonin-targeting anti-parasitic candidates. An intriguing finding from this study is that suramin, the first-line drug for treating early stage T. brucei infections, is also a potent inhibitor of GroEL/ES and HSP60/10 chaperonin systems. Copyright © 2016 Elsevier Ltd. All rights reserved.

Changes in blood sugar levels of rats experimentally infected with Trypanosoma brucei and treated with imidocarb dipropionate and diminazene aceturate

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Nwoha Rosemary Ijeoma Ogechi

2016-01-01

Full Text Available Objective: To determine the effect of Trypanosoma brucei (T. brucei on blood sugar level of infected rats. Methods: The experiment was done with 42 albino rats grouped into 3 groups of 14 members each. Group A was uninfected (control group, Group B was infected with T. brucei and treated with diminazene aceturate, and Group C was infected with T. brucei and treated with imidocarb dipropionate. Blood samples were collected from the media canthus of the experimental rats on Days 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 for the assessment of change in blood sugar levels. The blood sugar levels were determined with a glucometer (Accu-chek active serial No. GN: 10023338. Results: By 4 to 5 days post infection, there was a significant increase (P 0.05 was observed in the groups when compared with the control group till Day 12 of the experiment. Conclusions: T. brucei caused a significant increase in blood sugar of infected rats.

In vitro susceptibility of Trypanosoma brucei brucei to selected essential oils and their major components.

Science.gov (United States)

Costa, Sonya; Cavadas, Cláudia; Cavaleiro, Carlos; Salgueiro, Lígia; do Céu Sousa, Maria

2018-07-01

Aiming for discovering effective and harmless antitrypanosomal agents, 17 essential oils and nine major components were screened for their effects on T. b. brucei. The essential oils were obtained by hydrodistillation from fresh plant material and analyzed by GC and GC-MS. The trypanocidal activity was assessed using blood stream trypomastigotes cultures of T. b. brucei and the colorimetric resazurin method. The MTT test was used to assess the cytotoxicity of essential oils on macrophage cells and Selectivity Indexes were calculated. Of the 17 essential oils screened three showed high trypanocidal activity (IC 50  oils had no cytotoxic effects on macrophage cells showing the highest values of Selectivity Index (63.4, 9.0 and 11.8, respectively). The oils of Distichoselinum tenuifolium, Lavandula viridis, Origanum virens, Seseli tortuosom, Syzygium aromaticum, and Thymbra capitata also exhibited activity (IC 50 of 10-25 μg/mL) but showed cytotoxicity on macrophages. Of the nine compounds tested, α-pinene (IC 50 of 2.9 μg/mL) and citral (IC 50 of 18.9 μg/mL) exhibited the highest anti-trypanosomal activities. Citral is likely the active component of C. citratus and α-pinene is responsible for the antitrypanosomal effects of J. oxycedrus. The present work leads us to propose the J. oxycedrus, C. citratus and L. luisieri oils as valuable sources of new molecules for African Sleeping Sickness treatment. Copyright © 2018 Elsevier Inc. All rights reserved.

An Atypical Mitochondrial Carrier That Mediates Drug Action in Trypanosoma brucei.

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Juan P de Macêdo

2015-05-01

Full Text Available Elucidating the mechanism of action of trypanocidal compounds is an important step in the development of more efficient drugs against Trypanosoma brucei. In a screening approach using an RNAi library in T. brucei bloodstream forms, we identified a member of the mitochondrial carrier family, TbMCP14, as a prime candidate mediating the action of a group of anti-parasitic choline analogs. Depletion of TbMCP14 by inducible RNAi in both bloodstream and procyclic forms increased resistance of parasites towards the compounds by 7-fold and 3-fold, respectively, compared to uninduced cells. In addition, down-regulation of TbMCP14 protected bloodstream form mitochondria from a drug-induced decrease in mitochondrial membrane potential. Conversely, over-expression of the carrier in procyclic forms increased parasite susceptibility more than 13-fold. Metabolomic analyses of parasites over-expressing TbMCP14 showed increased levels of the proline metabolite, pyrroline-5-carboxylate, suggesting a possible involvement of TbMCP14 in energy production. The generation of TbMCP14 knock-out parasites showed that the carrier is not essential for survival of T. brucei bloodstream forms, but reduced parasite proliferation under standard culture conditions. In contrast, depletion of TbMCP14 in procyclic forms resulted in growth arrest, followed by parasite death. The time point at which parasite proliferation stopped was dependent on the major energy source, i.e. glucose versus proline, in the culture medium. Together with our findings that proline-dependent ATP production in crude mitochondria from TbMCP14-depleted trypanosomes was reduced compared to control mitochondria, the study demonstrates that TbMCP14 is involved in energy production in T. brucei. Since TbMCP14 belongs to a trypanosomatid-specific clade of mitochondrial carrier family proteins showing very poor similarity to mitochondrial carriers of mammals, it may represent an interesting target for drug

Novel sterol metabolic network of Trypanosoma brucei procyclic and bloodstream forms

Science.gov (United States)

Nes, Craigen R.; Singha, Ujjal K.; Liu, Jialin; Ganapathy, Kulothungan; Villalta, Fernando; Waterman, Michael R.; Lepesheva, Galina I.; Chaudhuri, Minu; Nes, W. David

2012-01-01

Trypanosoma brucei is the protozoan parasite that causes African trypanosomiasis, a neglected disease of people and animals. Co-metabolite analysis, labelling studies using [methyl-2H3]-methionine and substrate/product specificities of the cloned 24-SMT (sterol C24-methyltransferase) and 14-SDM (sterol C14-demethylase) from T. brucei afforded an uncommon sterol metabolic network that proceeds from lanosterol and 31-norlanosterol to ETO [ergosta-5,7,25(27)-trien-3β-ol], 24-DTO [dimethyl ergosta-5,7,25(27)-trienol] and ergosterol [ergosta-5,7,22(23)-trienol]. To assess the possible carbon sources of ergosterol biosynthesis, specifically 13C-labelled specimens of lanosterol, acetate, leucine and glucose were administered to T. brucei and the 13C distributions found were in accord with the operation of the acetate–mevalonate pathway, with leucine as an alternative precursor, to ergostenols in either the insect or bloodstream form. In searching for metabolic signatures of procyclic cells, we observed that the 13C-labelling treatments induce fluctuations between the acetyl-CoA (mitochondrial) and sterol (cytosolic) synthetic pathways detected by the progressive increase in 13C-ergosterol production (control sterol synthesis that is further fluctuated in the cytosol, yielding distinct sterol profiles in relation to cell demands on growth. PMID:22176028

In vitro trypanocidal activities of new S-adenosylmethionine decarboxylase inhibitors.

Science.gov (United States)

Brun, R; Bühler, Y; Sandmeier, U; Kaminsky, R; Bacchi, C J; Rattendi, D; Lane, S; Croft, S L; Snowdon, D; Yardley, V; Caravatti, G; Frei, J; Stanek, J; Mett, H

1996-01-01

A series of novel aromatic derivatives based on the structure of methylglyoxal bis(guanylhydrazone) (MGBG) was examined for in vitro antitrypanosomal activities and cytotoxicities for human cells. One-third of the compounds tested showed trypanocidal activity at concentrations below 0.5 microM after an incubation period of 72 h. Structure-activity analysis revealed that bicyclic compounds with homocyclic rings and unmodified termini were the most active compounds. Results obtained in three laboratories employing different methods and trypanosome populations consistently ranked compound CGP 40215A highest. This compound had a 50% inhibitory concentration of 0.0045 microM for Trypanosoma brucei rhodesiense, was also active against other trypanosome species, including a multidrug-resistant Trypanosoma brucei brucei, and was significantly less toxic than other compounds tested for a human adenocarcinoma cell line, with a 50% inhibitory concentration of 1.14 mM. The effect of CGP 40215A was time and dose dependent, and low concentrations of the compound required exposure times of > 2 days to exert trypanocidal activity. Compounds were inactive against Leishmania donovani and Trypanosoma cruzi amastigotes in murine macrophages in vitro. PMID:8726017

Alkanediamide-Linked Bisbenzamidines Are Promising Antiparasitic Agents

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Jean J. Vanden Eynde

2016-04-01

Full Text Available A series of 15 alkanediamide-linked bisbenzamidines and related analogs was synthesized and tested in vitro against two Trypanosoma brucei (T.b. subspecies: T.b. brucei and T.b. rhodesiense, Trypanosoma cruzi, Leishmania donovani and two Plasmodium falciparum subspecies: a chloroquine-sensitive strain (NF54 and a chloroquine-resistant strain (K1. The in vitro cytotoxicity was determined against rat myoblast cells (L6. Seven compounds (5, 6, 10, 11, 12, 14, 15 showed high potency against both strains of T. brucei and P. falciparum with the inhibitory concentrations for 50% (IC50 in the nanomolar range (IC50 = 1–96 nM. None of the tested derivatives was significantly active against T. cruzi or L. donovani. Three of the more potent compounds (5, 6, 11 were evaluated in vivo in mice infected with the drug-sensitive (Lab 110 EATRO and KETRI 2002 or drug-resistant (KETRI 2538 and KETRI 1992 clinical isolates of T. brucei. Compounds 5 and 6 were highly effective in curing mice infected with the drug-sensitive strains, including a drug-resistant strain KETRI 2538, but were ineffective against KETRI 1992. Thermal melting of DNA and molecular modeling studies indicate AT-rich DNA sequences as possible binding sites for these compounds. Several of the tested compounds are suitable leads for the development of improved antiparasitic agents.

Some liver function indices and blood parameters in T. brucei ...

African Journals Online (AJOL)

JTEkanem

symptoms of African sleeping sickness9. Despite the prolific research ... is a disease for which both man and other animals whether ... on some symptoms caused by T. brucei infection. .... immune response is insufficient to clear infection21-23.

Essential Assembly Factor Rpf2 Forms Novel Interactions within the 5S RNP in Trypanosoma brucei.

Science.gov (United States)

Kamina, Anyango D; Jaremko, Daniel; Christen, Linda; Williams, Noreen

2017-01-01

Ribosome biogenesis is a highly complex and conserved cellular process that is responsible for making ribosomes. During this process, there are several assembly steps that function as regulators to ensure proper ribosome formation. One of these steps is the assembly of the 5S ribonucleoprotein particle (5S RNP) in the central protuberance of the 60S ribosomal subunit. In eukaryotes, the 5S RNP is composed of 5S rRNA, ribosomal proteins L5 and L11, and assembly factors Rpf2 and Rrs1. Our laboratory previously showed that in Trypanosoma brucei , the 5S RNP is composed of 5S rRNA, L5, and trypanosome-specific RNA binding proteins P34 and P37. In this study, we characterize an additional component of the 5S RNP, the T. brucei homolog of Rpf2. This is the first study to functionally characterize interactions mediated by Rpf2 in an organism other than fungi. T . brucei Rpf2 (TbRpf2) was identified from tandem affinity purification using extracts prepared from protein A-tobacco etch virus (TEV)-protein C (PTP)-tagged L5, P34, and P37 cell lines, followed by mass spectrometry analysis. We characterized the binding interactions between TbRpf2 and the previously characterized members of the T. brucei 5S RNP. Our studies show that TbRpf2 mediates conserved binding interactions with 5S rRNA and L5 and that TbRpf2 also interacts with trypanosome-specific proteins P34 and P37. We performed RNA interference (RNAi) knockdown of TbRpf2 and showed that this protein is essential for the survival of the parasites and is critical for proper ribosome formation. These studies provide new insights into a critical checkpoint in the ribosome biogenesis pathway in T. brucei . IMPORTANCE Trypanosoma brucei is the parasitic protozoan that causes African sleeping sickness. Ribosome assembly is essential for the survival of this parasite through the different host environments it encounters during its life cycle. The assembly of the 5S ribonucleoprotein particle (5S RNP) functions as one of

Trypanosoma brucei Invasion and T-Cell Infiltration of the Brain Parenchyma in Experimental Sleeping Sickness: Timing and Correlation with Functional Changes.

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Claudia Laperchia

2016-12-01

Full Text Available The timing of Trypanosoma brucei entry into the brain parenchyma to initiate the second, meningoencephalitic stage of human African trypanosomiasis or sleeping sickness is currently debated and even parasite invasion of the neuropil has been recently questioned. Furthermore, the relationship between neurological features and disease stage are unclear, despite the important diagnostic and therapeutic implications.Using a rat model of chronic Trypanosoma brucei brucei infection we determined the timing of parasite and T-cell neuropil infiltration and its correlation with functional changes. Parasite DNA was detected using trypanosome-specific PCR. Body weight and sleep structure alterations represented by sleep-onset rapid eye movement (SOREM periods, reported in human and experimental African trypanosomiasis, were monitored. The presence of parasites, as well as CD4+ and CD8+ T-cells in the neuropil was assessed over time in the brain of the same animals by immunocytochemistry and quantitative analyses.Trypanosome DNA was present in the brain at day 6 post-infection and increased more than 15-fold by day 21. Parasites and T-cells were observed in the parenchyma from day 9 onwards. Parasites traversing blood vessel walls were observed in the hypothalamus and other brain regions. Body weight gain was reduced from day 7 onwards. SOREM episodes started in most cases early after infection, with an increase in number and duration after parasite neuroinvasion.These findings demonstrate invasion of the neuropil over time, after an initial interval, by parasites and lymphocytes crossing the blood-brain barrier, and show that neurological features can precede this event. The data thus challenge the current clinical and cerebrospinal fluid criteria of disease staging.

Trypanosoma brucei Invasion and T-Cell Infiltration of the Brain Parenchyma in Experimental Sleeping Sickness: Timing and Correlation with Functional Changes.

Science.gov (United States)

Laperchia, Claudia; Palomba, Maria; Seke Etet, Paul F; Rodgers, Jean; Bradley, Barbara; Montague, Paul; Grassi-Zucconi, Gigliola; Kennedy, Peter G E; Bentivoglio, Marina

2016-12-01

The timing of Trypanosoma brucei entry into the brain parenchyma to initiate the second, meningoencephalitic stage of human African trypanosomiasis or sleeping sickness is currently debated and even parasite invasion of the neuropil has been recently questioned. Furthermore, the relationship between neurological features and disease stage are unclear, despite the important diagnostic and therapeutic implications. Using a rat model of chronic Trypanosoma brucei brucei infection we determined the timing of parasite and T-cell neuropil infiltration and its correlation with functional changes. Parasite DNA was detected using trypanosome-specific PCR. Body weight and sleep structure alterations represented by sleep-onset rapid eye movement (SOREM) periods, reported in human and experimental African trypanosomiasis, were monitored. The presence of parasites, as well as CD4+ and CD8+ T-cells in the neuropil was assessed over time in the brain of the same animals by immunocytochemistry and quantitative analyses. Trypanosome DNA was present in the brain at day 6 post-infection and increased more than 15-fold by day 21. Parasites and T-cells were observed in the parenchyma from day 9 onwards. Parasites traversing blood vessel walls were observed in the hypothalamus and other brain regions. Body weight gain was reduced from day 7 onwards. SOREM episodes started in most cases early after infection, with an increase in number and duration after parasite neuroinvasion. These findings demonstrate invasion of the neuropil over time, after an initial interval, by parasites and lymphocytes crossing the blood-brain barrier, and show that neurological features can precede this event. The data thus challenge the current clinical and cerebrospinal fluid criteria of disease staging.

Rab23 is a flagellar protein in Trypanosoma brucei

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Field Mark C

2011-06-01

Full Text Available Abstract Background Rab small GTPases are important mediators of membrane transport, and orthologues frequently retain similar locations and functions, even between highly divergent taxa. In metazoan organisms Rab23 is an important negative regulator of Sonic hedgehog signaling and is crucial for correct development and differentiation of cellular lineages by virtue of an involvement in ciliary recycling. Previously, we reported that Trypanosoma brucei Rab23 localized to the nuclear envelope 1, which is clearly inconsistent with the mammalian location and function. As T. brucei is unicellular the potential that Rab23 has no role in cell signaling was possible. Here we sought to further investigate the role(s of Rab23 in T. brucei to determine if Rab23 was an example of a Rab protein with divergent function in distinct taxa. Methods/major findings The taxonomic distribution of Rab23 was examined and compared with the presence of flagella/cilia in representative taxa. Despite evidence for considerable secondary loss, we found a clear correlation between a conventional flagellar structure and the presence of a Rab23 orthologue in the genome. By epitope-tagging, Rab23 was localized and found to be present at the flagellum throughout the cell cycle. However, RNAi knockdown did not result in a flagellar defect, suggesting that Rab23 is not required for construction or maintenance of the flagellum. Conclusions The location of Rab23 at the flagellum is conserved between mammals and trypanosomes and the Rab23 gene is restricted to flagellated organisms. These data may suggest the presence of a Rab23-mediated signaling mechanism in trypanosomes.

Effect of rearing diet on the infection rate in flies released for the control of tsetse populations by sterile males

International Nuclear Information System (INIS)

Maudlin, I.

1990-01-01

In areas where sleeping sickness is endemic, it is the practice of sterile insect technique (SIT) programmes to give sterilized males a bloodmeal before release into the wild in order to reduce the risk of these released flies acting as disease vectors. This strategy has been adopted because of experimental evidence which showed that it was essential to infect flies at their first feed to establish a Tripanosoma brucei gambiense or T. b rhodesiense infection in tsetse flies. The aim of the work was to test artificial tsetse diets produced in the IAEA Laboratory at Seibersdorf in order to determine whether they were as effective as whole blood in inhibiting T. brucei sensu lato (sl) infections in flies. Seven artificial diets were tested with T.b. rhodesiense; Glossina morsitans morsitans males were fed one meal of the diet and then starved for 3 days before the infective feed. None of these diets significantly altered the infection rate of the treated flies and the seven groups produced statistically homogeneous results, with a mean midgut rate of 16% (control flies fed pig blood: 17%). Flies infected as tenerals with the same trypanosome stock produced midgut rates of 61%. Three of the diets were also tested with a T. congolense stock. There were no significant differences between flies fed artificial (mean midgut infection rate: 15%) and whole blood diets (19%). G. m. morsitans infected as tenerals with this trypanosome stock produced midgut rates of 66%. As with T. brucei sl infections, teneral flies were far more likely to develop a T. congolense infection than fed flies; this result suggests that all the tsetse flies used in SIT programmes should be fed before release in order to reduce the risk both to man and his livestock. Artificial diets are as effective as whole blood in inhibiting trypanosome infections. The effect of bloodmeal on the fly infection rates is discussed in relation to lectin production in fed flies. (author). 13 refs, 2 tabs

A tropical tale: how Naja nigricollis venom beats Trypanosoma brucei

DEFF Research Database (Denmark)

Martos Esteban, Andrea; Laustsen, Andreas Hougaard; Carrington, Mark

Trypanosoma brucei is a parasitic protozoan species capable to infecting insect vectors whose bite further produces African sleeping sickness inhuman beings [1]. During the parasite’s extracellular life in the mammalian host,its outer coat, mainly composed of Variable Surface Glycoproteins (VSGs)...

An outbreak of bovine trypanosomiasis in the Blue Nile State, Sudan

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Nakamura Ichiro

2011-05-01

Full Text Available Abstract Background In this paper, we report an outbreak of bovine trypanosomiasis in Kurmuk District, Blue Nile State, Sudan that involved an infection with four Trypanosoma species in cattle. The outbreak occurred in June 2010 when indigenous cattle, mainly Kenana and Fulani breed types, crossed the national Sudanese border to Ethiopia and returned. A veterinarian was notified of massive deaths in the cattle populations that recently came from Ethiopia. All animals involved in the outbreak were from the nomadic Fulani group and resident local cattle were not infected and no death has been reported among them. A total of 210 blood samples were collected from the ear vein of cattle. A few samples were also collected from other domestic animals species. Parasitological examinations including hematocrit centrifugation techniques (HCT and Giemsa-stained thin blood films were carried out. ITS1-PCR, which provides a multi-species-specific diagnosis in a single PCR, was performed. Findings Parasitological examinations revealed that 43% (91/210 of the affected cattle population was infected with two morphologically distinct trypanosomes. Seventy animals (33.3% were infected with T. vivax and twenty one (10% with T. congolense. In contrast, ITS1-PCR was able to identify four Trypanosoma species namely T. vivax, T. congolense, T. simiae and T. brucei in 56.7% (80/141. T. brucei showed the highest prevalence of 36.9% (52/141 and the lowest 19% (27/141 was displayed by T. congolense. Furthermore, and because ITS1-PCR could not differentiate between T. brucei subspecies, serum resistance-associated (SRA gene based PCR was used to detect the human T. brucei rhodesiense in T. brucei positive samples. None of the samples was shown positive for T. b. rhodesiense. The identity of the 400 bp PCR product originating from T. simiae, was further confirmed by sequencing and subsequent phylogenetic analysis. Conclusions The outbreak of bovine trypanosomiasis occurred

Sensitivity and Specificity of a Prototype Rapid Diagnostic Test for the Detection of Trypanosoma brucei gambiense Infection: A Multi-centric Prospective Study.

Science.gov (United States)

Bisser, Sylvie; Lumbala, Crispin; Nguertoum, Etienne; Kande, Victor; Flevaud, Laurence; Vatunga, Gedeao; Boelaert, Marleen; Büscher, Philippe; Josenando, Theophile; Bessell, Paul R; Biéler, Sylvain; Ndung'u, Joseph M

2016-04-01

A major challenge in the control of human African trypanosomiasis (HAT) is lack of reliable diagnostic tests that are rapid and easy to use in remote areas where the disease occurs. In Trypanosoma brucei gambiense HAT, the Card Agglutination Test for Trypanosomiasis (CATT) has been the reference screening test since 1978, usually on whole blood, but also in a 1/8 dilution (CATT 1/8) to enhance specificity. However, the CATT is not available in a single format, requires a cold chain for storage, and uses equipment that requires electricity. A solution to these challenges has been provided by rapid diagnostic tests (RDT), which have recently become available. A prototype immunochromatographic test, the SD BIOLINE HAT, based on two native trypanosomal antigens (VSG LiTat 1.3 and VSG LiTat 1.5) has been developed. We carried out a non-inferiority study comparing this prototype to the CATT 1/8 in field settings. The prototype SD BIOLINE HAT, the CATT Whole Blood and CATT 1/8 were systematically applied on fresh blood samples obtained from 14,818 subjects, who were prospectively enrolled through active and passive screening in clinical studies in three endemic countries of central Africa: Angola, the Democratic Republic of the Congo and the Central African Republic. One hundred and forty nine HAT cases were confirmed by parasitology. The sensitivity and specificity of the prototype SD BIOLINE HAT was 89.26% (95% confidence interval (CI) = 83.27-93.28) and 94.58% (95% CI = 94.20-94.94) respectively. The sensitivity and specificity of the CATT on whole blood were 93.96% (95% CI = 88.92-96.79) and 95.91% (95% CI = 95.58-96.22), and of the CATT 1/8 were 89.26% (95% CI = 83.27-93.28) and 98.88% (95% CI = 98.70-99.04) respectively. After further optimization, the prototype SD BIOLINE HAT could become an alternative to current screening methods in primary healthcare settings in remote, resource-limited regions where HAT typically occurs.

Serum Iron and Nitric Oxide Production in Trypanosoma brucei ...

African Journals Online (AJOL)

JTEkanem

reduction in the serum iron status and a modulation of nitric oxide synthase activity of T. brucei infected rats. ... inflammation and tissue damage15. ... The serum iron level was determined ... concentration or of total nitrate and nitrite ... 15. 16. 17. 18. Days. S e ru m iro n lev e l mg. /ml. Infected treated. Infected untreated. 0.

A Trypanosoma brucei kinesin heavy chain promotes parasite growth by triggering host arginase activity.

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Géraldine De Muylder

2013-10-01

Full Text Available In order to promote infection, the blood-borne parasite Trypanosoma brucei releases factors that upregulate arginase expression and activity in myeloid cells.By screening a cDNA library of T. brucei with an antibody neutralizing the arginase-inducing activity of parasite released factors, we identified a Kinesin Heavy Chain isoform, termed TbKHC1, as responsible for this effect. Following interaction with mouse myeloid cells, natural or recombinant TbKHC1 triggered SIGN-R1 receptor-dependent induction of IL-10 production, resulting in arginase-1 activation concomitant with reduction of nitric oxide (NO synthase activity. This TbKHC1 activity was IL-4Rα-independent and did not mirror M2 activation of myeloid cells. As compared to wild-type T. brucei, infection by TbKHC1 KO parasites was characterized by strongly reduced parasitaemia and prolonged host survival time. By treating infected mice with ornithine or with NO synthase inhibitor, we observed that during the first wave of parasitaemia the parasite growth-promoting effect of TbKHC1-mediated arginase activation resulted more from increased polyamine production than from reduction of NO synthesis. In late stage infection, TbKHC1-mediated reduction of NO synthesis appeared to contribute to liver damage linked to shortening of host survival time.A kinesin heavy chain released by T. brucei induces IL-10 and arginase-1 through SIGN-R1 signaling in myeloid cells, which promotes early trypanosome growth and favors parasite settlement in the host. Moreover, in the late stage of infection, the inhibition of NO synthesis by TbKHC1 contributes to liver pathogenicity.

Trypanosoma brucei solanesyl-diphosphate synthase localizes to the mitochondrion

Czech Academy of Sciences Publication Activity Database

Lai, D.-H.; Bontempi, E. J.; Lukeš, Julius

2012-01-01

Roč. 183, č. 2 (2012), s. 189-192 ISSN 0166-6851 R&D Projects: GA ČR(CZ) GAP305/11/2179 Institutional support: RVO:60077344 Keywords : Trypanosoma brucei * Sleeping sickness * Ubiquinone * Solanesyl-diphosphate synthase * Digitonin permeabilization * In situ tagging Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.734, year: 2012 http://www.sciencedirect.com/science/article/pii/S0166685112000539

Telomeric expression sites are highly conserved in Trypanosoma brucei.

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Christiane Hertz-Fowler

Full Text Available Subtelomeric regions are often under-represented in genome sequences of eukaryotes. One of the best known examples of the use of telomere proximity for adaptive purposes are the bloodstream expression sites (BESs of the African trypanosome Trypanosoma brucei. To enhance our understanding of BES structure and function in host adaptation and immune evasion, the BES repertoire from the Lister 427 strain of T. brucei were independently tagged and sequenced. BESs are polymorphic in size and structure but reveal a surprisingly conserved architecture in the context of extensive recombination. Very small BESs do exist and many functioning BESs do not contain the full complement of expression site associated genes (ESAGs. The consequences of duplicated or missing ESAGs, including ESAG9, a newly named ESAG12, and additional variant surface glycoprotein genes (VSGs were evaluated by functional assays after BESs were tagged with a drug-resistance gene. Phylogenetic analysis of constituent ESAG families suggests that BESs are sequence mosaics and that extensive recombination has shaped the evolution of the BES repertoire. This work opens important perspectives in understanding the molecular mechanisms of antigenic variation, a widely used strategy for immune evasion in pathogens, and telomere biology.

Chimerization at the AQP2–AQP3 locus is the genetic basis of melarsoprol–pentamidine cross-resistance in clinical Trypanosoma brucei gambiense isolates

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Fabrice E. Graf

2015-08-01

Full Text Available Aquaglyceroporin-2 is a known determinant of melarsoprol–pentamidine cross-resistance in Trypanosoma brucei brucei laboratory strains. Recently, chimerization at the AQP2–AQP3 tandem locus was described from melarsoprol–pentamidine cross-resistant Trypanosoma brucei gambiense isolates from sleeping sickness patients in the Democratic Republic of the Congo. Here, we demonstrate that reintroduction of wild-type AQP2 into one of these isolates fully restores drug susceptibility while expression of the chimeric AQP2/3 gene in aqp2–aqp3 null T. b. brucei does not. This proves that AQP2–AQP3 chimerization is the cause of melarsoprol–pentamidine cross-resistance in the T. b. gambiense isolates.

ATG24 Represses Autophagy and Differentiation and Is Essential for Homeostasy of the Flagellar Pocket in Trypanosoma brucei.

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Ana Brennand

Full Text Available We have previously identified homologs for nearly half of the approximately 30 known yeast Atg's in the genome database of the human sleeping sickness parasite Trypanosoma brucei. So far, only a few of these homologs have their role in autophagy experimentally confirmed. Among the candidates was the ortholog of Atg24 that is involved in pexophagy in yeast. In T. brucei, the peroxisome-like organelles named glycosomes harbor core metabolic processes, especially glycolysis. In the autotrophic yeast, autophagy is essential for adaptation to different nutritional environments by participating in the renewal of the peroxisome population. We hypothesized that autophagic turnover of the parasite's glycosomes plays a role in differentiation during its life cycle, which demands adaptation to different host environments and associated dramatic changes in nutritional conditions. We therefore characterized T. brucei ATG24, the T. brucei ortholog of yeast Atg24 and mammalian SNX4, and found it to have a regulatory role in autophagy and differentiation as well as endocytic trafficking. ATG24 partially localized on endocytic membranes where it was recruited via PI3-kinase III/VPS34. ATG24 silencing severely impaired receptor-mediated endocytosis of transferrin, but not adsorptive uptake of a lectin, and caused a major enlargement of the flagellar pocket. ATG24 silencing approximately doubled the number of autophagosomes, suggesting a role in repressing autophagy, and strongly accelerated differentiation, in accordance with a role of autophagy in parasite differentiation. Overexpression of the two isoforms of T. brucei ATG8 fused to GFP slowed down differentiation, possibly by a dominant-negative effect. This was overcome by ATG24 depletion, further supporting its regulatory role.

Identification of TOEFAZ1-interacting proteins reveals key regulators of Trypanosoma brucei cytokinesis.

Science.gov (United States)

Hilton, Nicholas A; Sladewski, Thomas E; Perry, Jenna A; Pataki, Zemplen; Sinclair-Davis, Amy N; Muniz, Richard S; Tran, Holly L; Wurster, Jenna I; Seo, Jiwon; de Graffenried, Christopher L

2018-05-21

The protist parasite Trypanosoma brucei is an obligate extracellular pathogen that retains its highly-polarized morphology during cell division and has evolved a novel cytokinetic process independent of non-muscle myosin II. The polo-like kinase homolog TbPLK is essential for transmission of cell polarity during division and for cytokinesis. We previously identified a putative TbPLK substrate named Tip of the Extending FAZ 1 (TOEFAZ1) as an essential kinetoplastid-specific component of the T. brucei cytokinetic machinery. We performed a proximity-dependent biotinylation (BioID) screen using TOEFAZ1 as a means to identify additional proteins that are involved in cytokinesis. Using quantitative proteomic methods, we identified nearly 500 TOEFAZ1-proximal proteins and characterized 59 in further detail. Among the candidates, we identified an essential putative phosphatase that regulates the expression level and localization of both TOEFAZ1 and TbPLK, a previously uncharacterized protein that is necessary for the assembly of a new cell posterior, and a microtubule plus-end directed orphan kinesin that is required for completing cleavage furrow ingression. The identification of these proteins provides new insight into T. brucei cytokinesis and establishes TOEFAZ1 as a key component of this essential and uniquely-configured process in kinetoplastids. This article is protected by copyright. All rights reserved. © 2018 John Wiley & Sons Ltd.

Structure of a Trypanosoma brucei α/β-hydrolase fold protein with unknown function

International Nuclear Information System (INIS)

Merritt, Ethan A.; Holmes, Margaret; Buckner, Frederick S.; Van Voorhis, Wesley C.; Quartly, Erin; Phizicky, Eric M.; Lauricella, Angela; Luft, Joseph; DeTitta, George; Neely, Helen; Zucker, Frank; Hol, Wim G. J.

2008-01-01

T. brucei gene Tb10.6k15.0140 codes for an α/β-hydrolase fold protein of unknown function. The 2.2 Å crystal structure shows that members of this sequence family retain a conserved Ser residue at the expected site of a catalytic nucleophile, but that trypanosomatid sequences lack structural homologs for the other expected residues of the catalytic triad. The structure of a structural genomics target protein, Tbru020260AAA from Trypanosoma brucei, has been determined to a resolution of 2.2 Å using multiple-wavelength anomalous diffraction at the Se K edge. This protein belongs to Pfam sequence family PF08538 and is only distantly related to previously studied members of the α/β-hydrolase fold family. Structural superposition onto representative α/β-hydrolase fold proteins of known function indicates that a possible catalytic nucleophile, Ser116 in the T. brucei protein, lies at the expected location. However, the present structure and by extension the other trypanosomatid members of this sequence family have neither sequence nor structural similarity at the location of other active-site residues typical for proteins with this fold. Together with the presence of an additional domain between strands β6 and β7 that is conserved in trypanosomatid genomes, this suggests that the function of these homologs has diverged from other members of the fold family

Overview of the Diagnostic Methods Used in the Field for Human African Trypanosomiasis: What Could Change in the Next Years?

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Julien Bonnet

2015-01-01

Full Text Available Sleeping sickness is a parasitic infection caused by two species of trypanosomes (Trypanosoma brucei gambiense and rhodesiense, transmitted by the tsetse fly. The disease eventually affects the central nervous system, resulting in severe neurological symptoms. Without treatment, death is inevitable. During the first stage of the disease, infected patients are mildly symptomatic and early detection of infection allows safer treatment (administered on an outpatient basis which can avoid death; routine screening of the exposed population is necessary, especially in areas of high endemicity. The current therapeutic treatment of this disease, especially in stage 2, can cause complications and requires a clinical surveillance for several days. A good stage diagnosis of the disease is the cornerstone for delivering the adequate treatment. The task faced by the medical personnel is further complicated by the lack of support from local health infrastructure, which is at best weak, but often nonexistent. Therefore it is crucial to look for new more efficient technics for the diagnosis of stage which are also best suited to use in the field, in areas not possessing high-level health facilities. This review, after an overview of the disease, summarizes the current diagnosis procedures and presents the advances in the field.

A target-based high throughput screen yields Trypanosoma brucei hexokinase small molecule inhibitors with antiparasitic activity.

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Elizabeth R Sharlow

2010-04-01

Full Text Available The parasitic protozoan Trypanosoma brucei utilizes glycolysis exclusively for ATP production during infection of the mammalian host. The first step in this metabolic pathway is mediated by hexokinase (TbHK, an enzyme essential to the parasite that transfers the gamma-phospho of ATP to a hexose. Here we describe the identification and confirmation of novel small molecule inhibitors of bacterially expressed TbHK1, one of two TbHKs expressed by T. brucei, using a high throughput screening assay.Exploiting optimized high throughput screening assay procedures, we interrogated 220,233 unique compounds and identified 239 active compounds from which ten small molecules were further characterized. Computation chemical cluster analyses indicated that six compounds were structurally related while the remaining four compounds were classified as unrelated or singletons. All ten compounds were approximately 20-17,000-fold more potent than lonidamine, a previously identified TbHK1 inhibitor. Seven compounds inhibited T. brucei blood stage form parasite growth (0.03brucei parasites, Leishmania promastigotes, and mammalian cell lines. Analysis of two structurally related compounds, ebselen and SID 17387000, revealed that both were mixed inhibitors of TbHK1 with respect to ATP. Additionally, both compounds inhibited parasite lysate-derived HK activity. None of the compounds displayed structural similarity to known hexokinase inhibitors or human African trypanosomiasis therapeutics.The novel chemotypes identified here could represent leads for future therapeutic development against the African trypanosome.

Procyclic Trypanosoma brucei do not use Krebs cycle activity for energy generation

NARCIS (Netherlands)

Weelden, van S.W.H.; Fast, B.; Vogt, A.; Meer, van der P.; Saas, J.; Hellemond, van J.J.; Tielens, A.G.M.; Boshart, M.

2003-01-01

The importance of a functional Krebs cycle for energy generation in the procyclic stage of Trypanosoma brucei was investigated under physiological conditions during logarithmic phase growth of a pleomorphic parasite strain. Wild type procyclic cells and mutants with targeted deletion of the gene

Studies on the localization of Trypanosoma brucei in the female reproductive tract of bka mice and hooded lister rats

International Nuclear Information System (INIS)

Chipepa, J.A.S.; Brown, H.; Holmes, P.

1991-01-01

A study was conducted to establish whether Trypanosoma brucei migrated preferentially to the reproductive tracts of female BKA mice, or Hooded Lister rats and lodged there as the site of choice compared to other organs. Blood flow to the reproductive tracts, the liver and spleen was measured using red blood cells labelled with chromium- 51. The distribution of trypanosomes labelled with 75 Se-methionine. The average percentage of the blood flow to the reproductive tract was 0.21Plus or minus0.08 in mice, while the mean concentration of trypanosomes there was 0.30% in both mice and rats. Blood flow to the liver was lower than the percentage distribution of Se-labelled T.Brucei(5.17Plus or minus1.34 versus 8.1Plus or Minus1.2). There were, on the contrary, less labelled trypanosomes as compared to the mean blood flow to the spleen (0.54% plus or minus0.18 versus 2.10%pPlus or minus0.88). After 24 hours there were adequate numbers of T. brucei in the reproductive tract to cause parasitaemia in recipient mice. From these preliminary data it was concluded that T. brucei did not lodge in the reproductive organ system a site of choice. (author). 9 refs., 3 tabs

Antiparasitic activity of diallyl trisulfide (Dasuansu) on human and animal pathogenic protozoa (Trypanosoma sp., Entamoeba histolytica and Giardia lamblia) in vitro.

Science.gov (United States)

Lun, Z R; Burri, C; Menzinger, M; Kaminsky, R

1994-03-01

Garlic (Allium sativum L.) and one of its major components, allicin, have been known to have antibacterial and antifungal activity for a long time. Diallyl trisulfide is a chemically stable final transformation product of allicin which was synthesized in 1981 in China and used for treatment of bacterial, fungal and parasitic infections in man. The activity of diallyl trisulfide was investigated in several important protozoan parasites in vitro. The IC50 (concentration which inhibits metabolism or growth of parasites by 50%) for Trypanosoma brucei brucei, T.b. rhodesiense, T.b. gambiense, T. evansi, T. congolense and T. equiperdum was in the range of 0.8-5.5 micrograms/ml. IC50 values were 59 micrograms/ml for Entamoeba histolytica and 14 micrograms/ml for Giardia lamblia. The cytotoxicity of the compound was evaluated on two fibroblast cell lines (MASEF, Mastomys natalensis embryo fibroblast and HEFL-12, human embryo fibroblast) in vitro. The maximum tolerated concentration for both cell lines was 25 micrograms/ml. The results indicate that the compound has potential to be used for treatment of several human and animal parasitic diseases.

Novel 1,2-dihydroquinazolin-2-ones: Design, synthesis, and biological evaluation against Trypanosoma brucei.

Science.gov (United States)

Pham, ThanhTruc; Walden, Madeline; Butler, Christopher; Diaz-Gonzalez, Rosario; Pérez-Moreno, Guiomar; Ceballos-Pérez, Gloria; Gomez-Pérez, Veronica; García-Hernández, Raquel; Zecca, Henry; Krakoff, Emma; Kopec, Brian; Ichire, Ogar; Mackenzie, Caden; Pitot, Marika; Ruiz, Luis Miguel; Gamarro, Francisco; González-Pacanowska, Dolores; Navarro, Miguel; Dounay, Amy B

2017-08-15

In 2014, a published report of the high-throughput screen of>42,000 kinase inhibitors from GlaxoSmithKline against T. brucei identified 797 potent and selective hits. From this rich data set, we selected NEU-0001101 (1) for hit-to-lead optimization. Through our preliminary compound synthesis and SAR studies, we have confirmed the previously reported activity of 1 in a T. brucei cell proliferation assay and have identified alternative groups to replace the pyridyl ring in 1. Pyrazole 24 achieves improvements in both potency and lipophilicity relative to 1, while also showing good in vitro metabolic stability. The SAR developed on 24 provides new directions for further optimization of this novel scaffold for anti-trypanosomal drug discovery. Copyright © 2017 Elsevier Ltd. All rights reserved.

Divergent Small Tim Homologues Are Associated with TbTim17 and Critical for the Biogenesis of TbTim17 Protein Complexes in Trypanosoma brucei

Science.gov (United States)

Smith, Joseph T.; Singha, Ujjal K.; Misra, Smita

2018-01-01

ABSTRACT The small Tim proteins belong to a group of mitochondrial intermembrane space chaperones that aid in the import of mitochondrial inner membrane proteins with internal targeting signals. Trypanosoma brucei, the protozoan parasite that causes African trypanosomiasis, possesses multiple small Tim proteins that include homologues of T. brucei Tim9 (TbTim9) and Tim10 (TbTim10) and a unique small Tim that shares homology with both Tim8 and Tim13 (TbTim8/13). Here, we found that these three small TbTims are expressed as soluble mitochondrial intermembrane space proteins. Coimmunoprecipitation and mass spectrometry analysis showed that the small TbTims stably associated with each other and with TbTim17, the major component of the mitochondrial inner membrane translocase in T. brucei. Yeast two-hybrid analysis indicated direct interactions among the small TbTims; however, their interaction patterns appeared to be different from those of their counterparts in yeast and humans. Knockdown of the small TbTims reduced cell growth and decreased the steady-state level of TbTim17 and T. brucei ADP/ATP carrier (TbAAC), two polytopic mitochondrial inner membrane proteins. Knockdown of small TbTims also reduced the matured complexes of TbTim17 in mitochondria. Depletion of any of the small TbTims reduced TbTim17 import moderately but greatly hampered the stability of the TbTim17 complexes in T. brucei. Altogether, our results revealed that TbTim9, TbTim10, and TbTim8/13 interact with each other, associate with TbTim17, and play a crucial role in the integrity and maintenance of the levels of TbTim17 complexes. IMPORTANCE Trypanosoma brucei is the causative agent of African sleeping sickness. The parasite’s mitochondrion represents a useful source for potential chemotherapeutic targets. Similarly to yeast and humans, mitochondrial functions depend on the import of proteins that are encoded in the nucleus and made in the cytosol. Even though the machinery involved in this

Neural Damage in Experimental Trypanosoma brucei gambiense Infection: Hypothalamic Peptidergic Sleep and Wake-Regulatory Neurons

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Claudia Laperchia

2018-02-01

Full Text Available Neuron populations of the lateral hypothalamus which synthesize the orexin (OX/hypocretin or melanin-concentrating hormone (MCH peptides play crucial, reciprocal roles in regulating wake stability and sleep. The disease human African trypanosomiasis (HAT, also called sleeping sickness, caused by extracellular Trypanosoma brucei (T. b. parasites, leads to characteristic sleep-wake cycle disruption and narcoleptic-like alterations of the sleep structure. Previous studies have revealed damage of OX and MCH neurons during systemic infection of laboratory rodents with the non-human pathogenic T. b. brucei subspecies. No information is available, however, on these peptidergic neurons after systemic infection with T. b. gambiense, the etiological agent of 97% of HAT cases. The present study was aimed at the investigation of immunohistochemically characterized OX and MCH neurons after T. b. gambiense or T. b. brucei infection of a susceptible rodent, the multimammate mouse, Mastomysnatalensis. Cell counts and evaluation of OX fiber density were performed at 4 and 8 weeks post-infection, when parasites had entered the brain parenchyma from the periphery. A significant decrease of OX neurons (about 44% reduction and MCH neurons (about 54% reduction was found in the lateral hypothalamus and perifornical area at 8 weeks in T. b. gambiense-infected M. natalensis. A moderate decrease (21% and 24% reduction, respectively, which did not reach statistical significance, was found after T. b. brucei infection. In two key targets of diencephalic orexinergic innervation, the peri-suprachiasmatic nucleus (SCN region and the thalamic paraventricular nucleus (PVT, densitometric analyses showed a significant progressive decrease in the density of orexinergic fibers in both infection paradigms, and especially during T. b. gambiense infection. Altogether the findings provide novel information showing that OX and MCH neurons are highly vulnerable to chronic

The detection and treatment of human African trypanosomiasis

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Bouteille B

2012-06-01

Full Text Available Bernard Bouteille,1 Alain Buguet21Laboratory of Parasitology, Dupuytren University Hospital of Limoges, France; 2Polyclinic Marie-Louise Poto-Djembo, Pointe-Noire, CongoAbstract: Human African trypanosomiasis (HAT is caused by the injection of Trypanosoma brucei (T. b. gambiense or T. b. rhodesiense by Glossina, the tsetse fly. Three historical eras followed the exclusive clinical approach of the 19th century. At the turn of the century, the “initial research” era was initiated because of the dramatic spread of HAT throughout intertropical Africa, and scientists discovered the agent and its vector. Two entities, recurrent fever and sleeping sickness, were then considered a continuum between hemolymphatic stage 1 and meningoencephalitic stage 2. Treatments were developed. Soon after World War I, specific services and mobile teams were created, initiating the “epidemiological” era, during which populations were visited, screened, and treated. As a result, by 1960, annual new cases were rare. New mass screening and staging tools were then developed in a third, “modern” era, especially to counter a new epidemic wave. Currently, diagnosis still relies on microscopic detection of trypanosomes without (wet and thick blood films or with concentration techniques (capillary tube centrifugation, miniature anion-exchange centrifugation technique. Staging is a vital step.Stage 1 patients are treated on site with pentamidine or suramin. However, stage 2 patients are treated in specialized facilities, using drugs that are highly toxic and/or that require complex administration procedures (melarsoprol, eflornithine, or nifurtimox-eflornithine combination therapy. Suramin and melarsoprol are the only medications active against Rhodesian HAT. Staging still relies on cerebrospinal fluid examination for trypanosome detection and white blood cell counts: stage 1, absence of trypanosomes, white blood cell counts ≤ 5/µL; stage 2, presence of

Novel molecular mechanism for targeting the parasite Trypanosoma brucei with snake venom toxins

DEFF Research Database (Denmark)

Martos Esteban, Andrea; Laustsen, Andreas Hougaard; Carrington, Mark

Trypanosoma brucei is a parasitic protozoan species capable to infecting insect vectors whose bite further produces African sleeping sickness inhuman beings. During parasites’extracellular lives in the mammalian host, its outer coat, mainly composedof Variable surface glycoproteins (VSGs)[2...

Trypanosoma brucei Mitochondrial Respiratome: Composition and Organization in Procyclic Form

Czech Academy of Sciences Publication Activity Database

Acestor, N.; Zíková, Alena; Dalley, R. A.; Anupama, A.; Panigrahi, A. K.; Stuart, K. D.

2011-01-01

Roč. 10, č. 9 (2011), s. 1-14 ISSN 1535-9476 R&D Projects: GA ČR GP204/09/P563 Institutional research plan: CEZ:AV0Z60220518 Keywords : SUCCINATE DEHYDROGENASE * EDITED MESSENGER-RNA * COMPLEX-I * TRYPANOSOMA-BRUCEI * UBIQUINONE OXIDOREDUCTASE * TAP-TAG * PROTEIN INTERACTION * ALTERNATIVE OXIDASE * STATISTICAL-MODEL * MASS-SPECTROMETRY Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 7.398, year: 2011

Inhibitory Activity of Marine Sponge-Derived Natural Products against Parasitic Protozoa

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Deniz Tasdemir

2010-01-01

Full Text Available In this study, thirteen sponge-derived terpenoids, including five linear furanoterpenes: furospinulosin-1 (1, furospinulosin-2 (2, furospongin-1 (3, furospongin-4 (4, and demethylfurospongin-4 (5; four linear meroterpenes: 2-(hexaprenylmethyl-2-methylchromenol (6, 4-hydroxy-3-octaprenylbenzoic acid (7, 4-hydroxy-3-tetraprenyl-phenylacetic acid (8, and heptaprenyl-p-quinol (9; a linear triterpene, squalene (10; two spongian-type diterpenes dorisenone D (11 and 11β-acetoxyspongi-12-en-16-one (12; a scalarane-type sesterterpene; 12-epi-deoxoscalarin (13, as well as an indole alkaloid, tryptophol (14 were screened for their in vitro activity against four parasitic protozoa; Trypanosoma brucei rhodesiense, Trypanosoma cruzi, Leishmania donovani and Plasmodium falciparum. Cytotoxic potential of the compounds on mammalian cells was also assessed. All compounds were active against T. brucei rhodesiense, with compound 8 being the most potent (IC50 0.60 μg/mL, whereas 9 and 12 were the most active compounds against T. cruzi, with IC50 values around 4 μg/mL. Compound 12 showed the strongest leishmanicidal activity (IC50 0.75 µg/mL, which was comparable to that of miltefosine (IC50 0.20 µg/mL. The best antiplasmodial effect was exerted by compound 11 (IC50 0.43 µg/mL, followed by compounds 7, 10, and 12 with IC50 values around 1 µg/mL. Compounds 9, 11 and 12 exhibited, besides their antiprotozoal activity, also some cytotoxicity, whereas all other compounds had low or no cytotoxicity towards the mammalian cell line. This is the first report of antiprotozoal activity of marine metabolites 1–14, and points out the potential of marine sponges in discovery of new antiprotozoal lead compounds.

Arterial blood pressure changes in acute T. brucei infection of dogs ...

African Journals Online (AJOL)

The aim of this study is to find out the usefulness of serial arterial blood pressure measurements in predicting severity and outcome of acute Trypanosoma brucei infection in dogs. Twenty adult dogs of mixed sexes and aged between 2 and 5 years were used for this study. The dogs were of good cardiac health and were ...

Meiosis and Haploid Gametes in the Pathogen Trypanosoma brucei

OpenAIRE

Peacock, Lori; Bailey, Mick; Carrington, Mark; Gibson, Wendy

2014-01-01

Summary In eukaryote pathogens, sex is an important driving force in spreading genes for drug resistance, pathogenicity, and virulence [1]. For the parasitic trypanosomes that cause African sleeping sickness, mating occurs during transmission by the tsetse vector [2, 3] and involves meiosis [4], but haploid gametes have not yet been identified. Here, we show that meiosis is a normal part of development in the insect salivary glands for all subspecies of Trypanosoma brucei, including the human...

Trypanosoma brucei Co-opts NK Cells to Kill Splenic B2 B Cells.

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Deborah Frenkel

2016-07-01

Full Text Available After infection with T. brucei AnTat 1.1, C57BL/6 mice lost splenic B2 B cells and lymphoid follicles, developed poor parasite-specific antibody responses, lost weight, became anemic and died with fulminating parasitemia within 35 days. In contrast, infected C57BL/6 mice lacking the cytotoxic granule pore-forming protein perforin (Prf1-/- retained splenic B2 B cells and lymphoid follicles, developed high-titer antibody responses against many trypanosome polypeptides, rapidly suppressed parasitemia and did not develop anemia or lose weight for at least 60 days. Several lines of evidence show that T. brucei infection-induced splenic B cell depletion results from natural killer (NK cell-mediated cytotoxicity: i B2 B cells were depleted from the spleens of infected intact, T cell deficient (TCR-/- and FcγRIIIa deficient (CD16-/- C57BL/6 mice excluding a requirement for T cells, NKT cell, or antibody-dependent cell-mediated cytotoxicity; ii administration of NK1.1 specific IgG2a (mAb PK136 but not irrelevant IgG2a (myeloma M9144 prevented infection-induced B cell depletion consistent with a requirement for NK cells; iii splenic NK cells but not T cells or NKT cells degranulated in infected C57BL/6 mice co-incident with B cell depletion evidenced by increased surface expression of CD107a; iv purified NK cells from naïve C57BL/6 mice killed purified splenic B cells from T. brucei infected but not uninfected mice in vitro indicating acquisition of an NK cell activating phenotype by the post-infection B cells; v adoptively transferred C57BL/6 NK cells prevented infection-induced B cell population growth in infected Prf1-/- mice consistent with in vivo B cell killing; vi degranulated NK cells in infected mice had altered gene and differentiation antigen expression and lost cytotoxic activity consistent with functional exhaustion, but increased in number as infection progressed indicating continued generation. We conclude that NK cells in T. brucei

Chemical characterisation of Nigerian red propolis and its biological activity against Trypanosoma Brucei.

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Omar, Ruwida M K; Igoli, John; Gray, Alexander I; Ebiloma, Godwin Unekwuojo; Clements, Carol; Fearnley, James; Ebel, Ru Angeli Edrada; Zhang, Tong; De Koning, Harry P; Watson, David G

2016-01-01

A previous study showed the unique character of Nigerian red propolis from Rivers State, Nigeria (RSN), with regards to chemical composition and activity against Trypanosoma brucei in comparison with other African propolis. To carry out fractionation and biological testing of Nigerian propolis in order to isolate compounds with anti-trypanosomal activity. To compare the composition of the RSN propolis with the composition of Brazilian red propolis. Profiling was carried out using HPLC-UV-ELSD and HPLC-Orbitrap-FTMS on extracts of two samples collected from RSN with data extraction using MZmine software. Isolation was carried out by normal phase and reversed phase MPLC. Elucidation of the compounds with a purity > 95% was performed by 1D/2D NMR HRMS and HRLC-MS(n) . Ten phenolic compounds were isolated or in the case of liquiritigenin partially purified. Data for nine of these correlated with literature reports of known compounds i.e. one isoflavanone, calycosin (1); two flavanones, liquiritigenin (2) and pinocembrin (5); an isoflavan, vestitol (3); a pterocarpan, medicarpin (4); two prenylflavanones, 8-prenylnaringenin (7) and 6-prenylnaringenin (8); and two geranyl flavonoids, propolin D (9) and macarangin (10). The tenth was elucidated as a previously undescribed dihydrobenzofuran (6). The isolated compounds were tested against Trypanosoma brucei and displayed moderate to high activity. Some of the compounds tested had similar activity against wild type T. brucei and two strains displaying pentamidine resistance. Nigerian propolis from RSN has some similarities with Brazilian red propolis. The propolis displayed anti-trypanosomal activity at a potentially useful level. Copyright © 2015 John Wiley & Sons, Ltd.

Adenylate Cyclases of Trypanosoma brucei, Environmental Sensors and Controllers of Host Innate Immune Response.

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Salmon, Didier

2018-04-25

Trypanosoma brucei , etiological agent of Sleeping Sickness in Africa, is the prototype of African trypanosomes, protozoan extracellular flagellate parasites transmitted by saliva ( Salivaria ). In these parasites the molecular controls of the cell cycle and environmental sensing are elaborate and concentrated at the flagellum. Genomic analyses suggest that these parasites appear to differ considerably from the host in signaling mechanisms, with the exception of receptor-type adenylate cyclases (AC) that are topologically similar to receptor-type guanylate cyclase (GC) of higher eukaryotes but control a new class of cAMP targets of unknown function, the cAMP response proteins (CARPs), rather than the classical protein kinase A cAMP effector (PKA). T. brucei possesses a large polymorphic family of ACs, mainly associated with the flagellar membrane, and these are involved in inhibition of the innate immune response of the host prior to the massive release of immunomodulatory factors at the first peak of parasitemia. Recent evidence suggests that in T. brucei several insect-specific AC isoforms are involved in social motility, whereas only a few AC isoforms are involved in cytokinesis control of bloodstream forms, attesting that a complex signaling pathway is required for environmental sensing. In this review, after a general update on cAMP signaling pathway and the multiple roles of cAMP, I summarize the existing knowledge of the mechanisms by which pathogenic microorganisms modulate cAMP levels to escape immune defense.

Adenylate Cyclases of Trypanosoma brucei, Environmental Sensors and Controllers of Host Innate Immune Response

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Didier Salmon

2018-04-01

Full Text Available Trypanosoma brucei, etiological agent of Sleeping Sickness in Africa, is the prototype of African trypanosomes, protozoan extracellular flagellate parasites transmitted by saliva (Salivaria. In these parasites the molecular controls of the cell cycle and environmental sensing are elaborate and concentrated at the flagellum. Genomic analyses suggest that these parasites appear to differ considerably from the host in signaling mechanisms, with the exception of receptor-type adenylate cyclases (AC that are topologically similar to receptor-type guanylate cyclase (GC of higher eukaryotes but control a new class of cAMP targets of unknown function, the cAMP response proteins (CARPs, rather than the classical protein kinase A cAMP effector (PKA. T. brucei possesses a large polymorphic family of ACs, mainly associated with the flagellar membrane, and these are involved in inhibition of the innate immune response of the host prior to the massive release of immunomodulatory factors at the first peak of parasitemia. Recent evidence suggests that in T. brucei several insect-specific AC isoforms are involved in social motility, whereas only a few AC isoforms are involved in cytokinesis control of bloodstream forms, attesting that a complex signaling pathway is required for environmental sensing. In this review, after a general update on cAMP signaling pathway and the multiple roles of cAMP, I summarize the existing knowledge of the mechanisms by which pathogenic microorganisms modulate cAMP levels to escape immune defense.

Central Nervous System Parasitosis and Neuroinflammation Ameliorated by Systemic IL-10 Administration in Trypanosoma brucei-Infected Mice.

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Jean Rodgers

Full Text Available Invasion of the central nervous system (CNS by African trypanosomes represents a critical step in the development of human African trypanosomiasis. In both clinical cases and experimental mouse infections it has been demonstrated that predisposition to CNS invasion is associated with a type 1 systemic inflammatory response. Using the Trypanosoma brucei brucei GVR35 experimental infection model, we demonstrate that systemic delivery of the counter-inflammatory cytokine IL-10 lowers plasma IFN-γ and TNF-α concentrations, CNS parasitosis and ameliorates neuro-inflammatory pathology and clinical symptoms of disease. The results provide evidence that CNS invasion may be susceptible to immunological attenuation.

The promoter for a variant surface glycoprotein gene expression site in Trypanosoma brucei

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Zomerdijk, J. C.; Ouellette, M.; ten Asbroek, A. L.; Kieft, R.; Bommer, A. M.; Clayton, C. E.; Borst, P.

1990-01-01

The variant-specific surface glycoprotein (VSG) gene 221 of Trypanosoma brucei is transcribed as part of a 60 kb expression site (ES). We have identified the promoter controlling this multigene transcription unit by the use of 221 chromosome-enriched DNA libraries and VSG gene 221 expression site

Handling uncertainty in dynamic models: the pentose phosphate pathway in Trypanosoma brucei.

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Eduard J Kerkhoven

Full Text Available Dynamic models of metabolism can be useful in identifying potential drug targets, especially in unicellular organisms. A model of glycolysis in the causative agent of human African trypanosomiasis, Trypanosoma brucei, has already shown the utility of this approach. Here we add the pentose phosphate pathway (PPP of T. brucei to the glycolytic model. The PPP is localized to both the cytosol and the glycosome and adding it to the glycolytic model without further adjustments leads to a draining of the essential bound-phosphate moiety within the glycosome. This phosphate "leak" must be resolved for the model to be a reasonable representation of parasite physiology. Two main types of theoretical solution to the problem could be identified: (i including additional enzymatic reactions in the glycosome, or (ii adding a mechanism to transfer bound phosphates between cytosol and glycosome. One example of the first type of solution would be the presence of a glycosomal ribokinase to regenerate ATP from ribose 5-phosphate and ADP. Experimental characterization of ribokinase in T. brucei showed that very low enzyme levels are sufficient for parasite survival, indicating that other mechanisms are required in controlling the phosphate leak. Examples of the second type would involve the presence of an ATP:ADP exchanger or recently described permeability pores in the glycosomal membrane, although the current absence of identified genes encoding such molecules impedes experimental testing by genetic manipulation. Confronted with this uncertainty, we present a modeling strategy that identifies robust predictions in the context of incomplete system characterization. We illustrate this strategy by exploring the mechanism underlying the essential function of one of the PPP enzymes, and validate it by confirming the model predictions experimentally.

Minimum Information Loss Based Multi-kernel Learning for Flagellar Protein Recognition in Trypanosoma Brucei

KAUST Repository

Wang, Jim Jing-Yan; Gao, Xin

2014-01-01

for the purposes of both biological research and drug design. In this paper, we investigate computationally recognizing flagellar proteins in T. Brucei by pattern recognition methods. It is argued that an optimal decision function can be obtained as the difference

The F1 -ATPase from Trypanosoma brucei is elaborated by three copies of an additional p18-subunit.

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Gahura, Ondřej; Šubrtová, Karolína; Váchová, Hana; Panicucci, Brian; Fearnley, Ian M; Harbour, Michael E; Walker, John E; Zíková, Alena

2018-02-01

The F-ATPases (also called the F 1 F o -ATPases or ATP synthases) are multi-subunit membrane-bound molecular machines that produce ATP in bacteria and in eukaryotic mitochondria and chloroplasts. The structures and enzymic mechanisms of their F 1 -catalytic domains are highly conserved in all species investigated hitherto. However, there is evidence that the F-ATPases from the group of protozoa known as Euglenozoa have novel features. Therefore, we have isolated pure and active F 1 -ATPase from the euglenozoan parasite, Trypanosoma brucei, and characterized it. All of the usual eukaryotic subunits (α, β, γ, δ, and ε) were present in the enzyme, and, in addition, two unique features were detected. First, each of the three α-subunits in the F 1 -domain has been cleaved by proteolysis in vivo at two sites eight residues apart, producing two assembled fragments. Second, the T. brucei F 1 -ATPase has an additional subunit, called p18, present in three copies per complex. Suppression of expression of p18 affected in vitro growth of both the insect and infectious mammalian forms of T. brucei. It also reduced the levels of monomeric and multimeric F-ATPase complexes and diminished the in vivo hydrolytic activity of the enzyme significantly. These observations imply that p18 plays a role in the assembly of the F 1 domain. These unique features of the F 1 -ATPase extend the list of special characteristics of the F-ATPase from T. brucei, and also, demonstrate that the architecture of the F 1 -ATPase complex is not strictly conserved in eukaryotes. © 2017 Federation of European Biochemical Societies.

Major surface glycoproteins of insect forms of Trypanosoma brucei are not essential for cyclical transmission by tsetse.

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Erik Vassella

Full Text Available Procyclic forms of Trypanosoma brucei reside in the midgut of tsetse flies where they are covered by several million copies of glycosylphosphatidylinositol-anchored proteins known as procyclins. It has been proposed that procyclins protect parasites against proteases and/or participate in tropism, directing them from the midgut to the salivary glands. There are four different procyclin genes, each subject to elaborate levels of regulation. To determine if procyclins are essential for survival and transmission of T. brucei, all four genes were deleted and parasite fitness was compared in vitro and in vivo. When co-cultured in vitro, the null mutant and wild type trypanosomes (tagged with cyan fluorescent protein maintained a near-constant equilibrium. In contrast, when flies were infected with the same mixture, the null mutant was rapidly overgrown in the midgut, reflecting a reduction in fitness in vivo. Although the null mutant is patently defective in competition with procyclin-positive parasites, on its own it can complete the life cycle and generate infectious metacyclic forms. The procyclic form of T. brucei thus differs strikingly from the bloodstream form, which does not tolerate any perturbation of its variant surface glycoprotein coat, and from other parasites such as Plasmodium berghei, which requires the circumsporozoite protein for successful transmission to a new host.

Exploring the Trypanosoma brucei Hsp83 potential as a target for structure guided drug design.

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Juan Carlos Pizarro

Full Text Available Human African trypanosomiasis is a neglected parasitic disease that is fatal if untreated. The current drugs available to eliminate the causative agent Trypanosoma brucei have multiple liabilities, including toxicity, increasing problems due to treatment failure and limited efficacy. There are two approaches to discover novel antimicrobial drugs--whole-cell screening and target-based discovery. In the latter case, there is a need to identify and validate novel drug targets in Trypanosoma parasites. The heat shock proteins (Hsp, while best known as cancer targets with a number of drug candidates in clinical development, are a family of emerging targets for infectious diseases. In this paper, we report the exploration of T. brucei Hsp83--a homolog of human Hsp90--as a drug target using multiple biophysical and biochemical techniques. Our approach included the characterization of the chemical sensitivity of the parasitic chaperone against a library of known Hsp90 inhibitors by means of differential scanning fluorimetry (DSF. Several compounds identified by this screening procedure were further studied using isothermal titration calorimetry (ITC and X-ray crystallography, as well as tested in parasite growth inhibitions assays. These experiments led us to the identification of a benzamide derivative compound capable of interacting with TbHsp83 more strongly than with its human homologs and structural rationalization of this selectivity. The results highlight the opportunities created by subtle structural differences to develop new series of compounds to selectively target the Trypanosoma brucei chaperone and effectively kill the sleeping sickness parasite.

Trypanocidal action of bisphosphonium salts through a mitochondrial target in bloodstream form Trypanosoma brucei

Czech Academy of Sciences Publication Activity Database

Alkhaldi, A.A.M.; Martínek, Jan; Panicucci, Brian; Dardonville, C.; Zíková, Alena; de Koning, H.P.

2016-01-01

Roč. 6, č. 1 (2016), s. 23-34 ISSN 2211-3207 R&D Projects: GA MŠk LL1205 Institutional support: RVO:60077344 Keywords : Trypanosoma brucei * mitochondrion * FoF1 ATPase * succinate dehydrogenase * phosphonium salt * SDH complex Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.809, year: 2016

Anti-Parasitic Activities of Allium sativum and Allium cepa against Trypanosoma b. brucei and Leishmania tarentolae.

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Krstin, Sonja; Sobeh, Mansour; Braun, Markus Santhosh; Wink, Michael

2018-04-21

Background: Garlics and onions have been used for the treatment of diseases caused by parasites and microbes since ancient times. Trypanosomiasis and leishmaniasis are a concern in many areas of the world, especially in poor countries. Methods: Trypanosoma brucei brucei and Leishmania tarentolae were used to investigate the anti-parasitic effects of dichloromethane extracts of Allium sativum (garlic) and Allium cepa (onion) bulbs. As a confirmation of known antimicrobial activities, they were studied against a selection of G-negative, G-positive bacteria and two fungi. Chemical analyses were performed using high-performance liquid chromatography (HPLC) and electrospray ionization-mass spectrometry (LC-ESI-MS/MS). Results: Chemical analyses confirmed the abundance of several sulfur secondary metabolites in garlic and one (zwiebelane) in the onion extract. Both extracts killed both types of parasites efficiently and inhibited the Trypanosoma brucei trypanothione reductase irreversibly. In addition, garlic extract decreased the mitochondrial membrane potential in trypanosomes. Garlic killed the fungi C. albicans and C. parapsilosis more effectively than the positive control. The combinations of garlic and onion with common trypanocidal and leishmanicidal drugs resulted in a synergistic or additive effect in 50% of cases. Conclusion: The mechanism for biological activity of garlic and onion appears to be related to the amount and the profile of sulfur-containing compounds. It is most likely that vital substances inside the parasitic cell, like trypanothione reductase, are inhibited through disulfide bond formation between SH groups of vital redox compounds and sulfur-containing secondary metabolites.

Proteome remodelling during development from blood to insect-form Trypanosoma brucei quantified by SILAC and mass spectrometry

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Gunasekera Kapila

2012-10-01

Full Text Available Abstract Background Trypanosoma brucei is the causative agent of human African sleeping sickness and Nagana in cattle. In addition to being an important pathogen T. brucei has developed into a model system in cell biology. Results Using Stable Isotope Labelling of Amino acids in Cell culture (SILAC in combination with mass spectrometry we determined the abundance of >1600 proteins in the long slender (LS, short stumpy (SS mammalian bloodstream form stages relative to the procyclic (PC insect-form stage. In total we identified 2645 proteins, corresponding to ~30% of the total proteome and for the first time present a comprehensive overview of relative protein levels in three life stages of the parasite. Conclusions We can show the extent of pre-adaptation in the SS cells, especially at the level of the mitochondrial proteome. The comparison to a previously published report on monomorphic in vitro grown bloodstream and procyclic T. brucei indicates a loss of stringent regulation particularly of mitochondrial proteins in these cells when compared to the pleomorphic in vivo situation. In order to better understand the different levels of gene expression regulation in this organism we compared mRNA steady state abundance with the relative protein abundance-changes and detected moderate but significant correlation indicating that trypanosomes possess a significant repertoire of translational and posttranslational mechanisms to regulate protein abundance.

Functional characterisation and drug target validation of a mitotic kinesin-13 in Trypanosoma brucei.

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Kuan Yoow Chan

2010-08-01

Full Text Available Mitotic kinesins are essential for faithful chromosome segregation and cell proliferation. Therefore, in humans, kinesin motor proteins have been identified as anti-cancer drug targets and small molecule inhibitors are now tested in clinical studies. Phylogenetic analyses have assigned five of the approximately fifty kinesin motor proteins coded by Trypanosoma brucei genome to the Kinesin-13 family. Kinesins of this family have unusual biochemical properties because they do not transport cargo along microtubules but are able to depolymerise microtubules at their ends, therefore contributing to the regulation of microtubule length. In other eukaryotic genomes sequenced to date, only between one and three Kinesin-13s are present. We have used immunolocalisation, RNAi-mediated protein depletion, biochemical in vitro assays and a mouse model of infection to study the single mitotic Kinesin-13 in T. brucei. Subcellular localisation of all five T. brucei Kinesin-13s revealed distinct distributions, indicating that the expansion of this kinesin family in kinetoplastids is accompanied by functional diversification. Only a single kinesin (TbKif13-1 has a nuclear localisation. Using active, recombinant TbKif13-1 in in vitro assays we experimentally confirm the depolymerising properties of this kinesin. We analyse the biological function of TbKif13-1 by RNAi-mediated protein depletion and show its central role in regulating spindle assembly during mitosis. Absence of the protein leads to abnormally long and bent mitotic spindles, causing chromosome mis-segregation and cell death. RNAi-depletion in a mouse model of infection completely prevents infection with the parasite. Given its essential role in mitosis, proliferation and survival of the parasite and the availability of a simple in vitro activity assay, TbKif13-1 has been identified as an excellent potential drug target.

Constraints to estimating the prevalence of trypanosome infections in East African zebu cattle.

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Cox, Andrew P; Tosas, Olga; Tilley, Aimee; Picozzi, Kim; Coleman, Paul; Hide, Geoff; Welburn, Susan C

2010-09-06

In East Africa, animal trypanosomiasis is caused by many tsetse transmitted protozoan parasites including Trypanosoma vivax, T. congolense and subspecies of T. brucei s.l. (T. b. brucei and zoonotic human infective T. b. rhodesiense) that may co-circulate in domestic and wild animals. Accurate species-specific prevalence measurements of these parasites in animal populations are complicated by mixed infections of trypanosomes within individual hosts, low parasite densities and difficulties in conducting field studies. Many Polymerase Chain Reaction (PCR) based diagnostic tools are available to characterise and quantify infection in animals. These are important for assessing the contribution of infections in animal reservoirs and the risk posed to humans from zoonotic trypanosome species. New matrices for DNA capture have simplified large scale field PCR analyses but few studies have examined the impact of these techniques on prevalence estimations. The Whatman FTA matrix has been evaluated using a random sample of 35 village zebu cattle from a population naturally exposed to trypanosome infection. Using a generic trypanosome-specific PCR, prevalence was systematically evaluated. Multiple PCR samples taken from single FTA cards demonstrated that a single punch from an FTA card is not sufficient to confirm the infectivity status of an individual animal as parasite DNA is unevenly distributed across the card. At low parasite densities in the host, this stochastic sampling effect results in underestimation of prevalence based on single punch PCR testing. Repeated testing increased the estimated prevalence of all Trypanosoma spp. from 9.7% to 86%. Using repeat testing, a very high prevalence of pathogenic trypanosomes was detected in these local village cattle: T. brucei (34.3%), T. congolense (42.9%) and T. vivax (22.9%). These results show that, despite the convenience of Whatman FTA cards and specific PCR based detection tools, the chronically low parasitaemias in

Inhibitors of the mitochondrial cytochrome b-c1 complex inhibit the cyanide-insensitive respiration of Trypanosoma brucei.

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Turrens, J F; Bickar, D; Lehninger, A L

1986-06-01

The cyanide-insensitive respiration of bloodstream trypomastigote forms of Trypanosoma brucei (75 +/- 8 nmol O2 min-1(mg protein)-1) is completely inhibited by the mitochondrial ubiquinone-like inhibitors 2-hydroxy-3-undecyl-1,4-naphthoquinone (UHNQ) and 5-n-undecyl-6-hydroxy-4,7-dioxobenzothiazole (UHDBT). The Ki values for UHDBT (30 nM) and UHNQ (2 microM) are much lower than the reported Ki for salicylhydroxamic acid (SHAM) (5 microM), a widely used inhibitor of the cyanide-insensitive oxidase. UHNQ also stimulated the glycerol-3-phosphate-dependent reduction of phenazine methosulfate, demonstrating that the site of UHNQ inhibition is on the terminal oxidase of the cyanide-insensitive respiration of T. brucei. These results suggest that a ubiquinone-like compound may act as an electron carrier between the two enzymatic components of the cyanide-insensitive glycerol-3-phosphate oxidase.

Structure Elucidation and Activity of Kolossin A, the D-/L-Pentadecapeptide Product of a Giant Nonribosomal Peptide Synthetase.

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Bode, Helge B; Brachmann, Alexander O; Jadhav, Kirtikumar B; Seyfarth, Lydia; Dauth, Christina; Fuchs, Sebastian W; Kaiser, Marcel; Waterfield, Nick R; Sack, Holger; Heinemann, Stefan H; Arndt, Hans-Dieter

2015-08-24

The largest continuous bacterial nonribosomal peptide synthetase discovered so far is described. It consists of 15 consecutive modules arising from an uninterrupted, fully functional gene in the entomopathogenic bacterium Photorhabdus luminescens. The identification of its cryptic biosynthesis product was achieved by using a combination of genome analysis, promoter exchange, isotopic labeling experiments, and total synthesis of a focused collection of peptide candidates. Although it belongs to the growing class of D-/ L-peptide natural products, the encoded metabolite kolossin A was found to be largely devoid of antibiotic activity and is likely involved in interspecies communication. A stereoisomer of this peculiar natural product displayed high activity against Trypanosoma brucei rhodesiense, a recalcitrant parasite that causes the deadly disease African sleeping sickness. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Two Trypanocidal Dipeptides from the Roots of Zapoteca portoricensis (Fabaceae

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Ngozi Justina Nwodo

2014-04-01

Full Text Available Zapoteca portoricensis (Jacq HM Hernández is used with remarkable efficacy in ethnomedicinal management of tonsillitis in the Eastern part of Nigeria. Previous pharmacological studies have validated the antiinflammatory and antimicrobial activities of the crude extract. In this study, two dipeptides, saropeptate (aurantiamide acetate and anabellamide, were isolated from the methanol root extract of Zapoteca portoricensis and their chemical structures deduced by one dimensional and two dimensional NMR and mass spectrometry. These compounds were isolated for the first time from this plant, and no report has been found on their previous isolation from the genus Zapoteca. Evaluation of their trypanocidal activity showed that compound 1 exhibited potent activity against Trypanosoma brucei rhodesiense with an IC50 value of 3.63 μM and selectivity index of 25.3.

Trypanosoma brucei metabolite indolepyruvate decreases HIF-1α and glycolysis in macrophages as a mechanism of innate immune evasion.

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McGettrick, Anne F; Corcoran, Sarah E; Barry, Paul J G; McFarland, Jennifer; Crès, Cécile; Curtis, Anne M; Franklin, Edward; Corr, Sinéad C; Mok, K Hun; Cummins, Eoin P; Taylor, Cormac T; O'Neill, Luke A J; Nolan, Derek P

2016-11-29

The parasite Trypanasoma brucei causes African trypanosomiasis, known as sleeping sickness in humans and nagana in domestic animals. These diseases are a major burden in the 36 sub-Saharan African countries where the tsetse fly vector is endemic. Untreated trypanosomiasis is fatal and the current treatments are stage-dependent and can be problematic during the meningoencephalitic stage, where no new therapies have been developed in recent years and the current drugs have a low therapeutic index. There is a need for more effective treatments and a better understanding of how these parasites evade the host immune response will help in this regard. The bloodstream form of T. brucei excretes significant amounts of aromatic ketoacids, including indolepyruvate, a transamination product of tryptophan. This study demonstrates that this process is essential in bloodstream forms, is mediated by a specialized isoform of cytoplasmic aminotransferase and, importantly, reveals an immunomodulatory role for indolepyruvate. Indolepyruvate prevents the LPS-induced glycolytic shift in macrophages. This effect is the result of an increase in the hydroxylation and degradation of the transcription factor hypoxia-inducible factor-1α (HIF-1α). The reduction in HIF-1α levels by indolepyruvate, following LPS or trypanosome activation, results in a decrease in production of the proinflammatory cytokine IL-1β. These data demonstrate an important role for indolepyruvate in immune evasion by T. brucei.

γ-Tubulin complex in Trypanosoma brucei: molecular composition, subunit interdependence and requirement for axonemal central pair protein assembly.

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Zhou, Qing; Li, Ziyin

2015-11-01

γ-Tubulin complex constitutes a key component of the microtubule-organizing center and nucleates microtubule assembly. This complex differs in complexity in different organisms: the budding yeast contains the γ-tubulin small complex (γTuSC) composed of γ-tubulin, gamma-tubulin complex protein (GCP)2 and GCP3, whereas animals contain the γ-tubulin ring complex (γTuRC) composed of γTuSC and three additional proteins, GCP4, GCP5 and GCP6. In Trypanosoma brucei, the composition of the γ-tubulin complex remains elusive, and it is not known whether it also regulates assembly of the subpellicular microtubules and the spindle microtubules. Here we report that the γ-tubulin complex in T. brucei is composed of γ-tubulin and three GCP proteins, GCP2-GCP4, and is primarily localized in the basal body throughout the cell cycle. Depletion of GCP2 and GCP3, but not GCP4, disrupted the axonemal central pair microtubules, but not the subpellicular microtubules and the spindle microtubules. Furthermore, we showed that the γTuSC is required for assembly of two central pair proteins and that γTuSC subunits are mutually required for stability. Together, these results identified an unusual γ-tubulin complex in T. brucei, uncovered an essential role of γTuSC in central pair protein assembly, and demonstrated the interdependence of individual γTuSC components for maintaining a stable complex. © 2015 John Wiley & Sons Ltd.

Troglitazone induces differentiation in Trypanosoma brucei

International Nuclear Information System (INIS)

Denninger, Viola; Figarella, Katherine; Schoenfeld, Caroline; Brems, Stefanie; Busold, Christian; Lang, Florian; Hoheisel, Joerg; Duszenko, Michael

2007-01-01

Trypanosoma brucei, a protozoan parasite causing sleeping sickness, is transmitted by the tsetse fly and undergoes a complex lifecycle including several defined stages within the insect vector and its mammalian host. In the latter, differentiation from the long slender to the short stumpy form is induced by a yet unknown factor of trypanosomal origin. Here we describe that some thiazolidinediones are also able to induce differentiation. In higher eukaryotes, thiazolidinediones are involved in metabolism and differentiation processes mainly by binding to the intracellular receptor peroxisome proliferator activated receptor γ. Our studies focus on the effects of troglitazone on bloodstream form trypanosomes. Differentiation was monitored using mitochondrial markers (membrane potential, succinate dehydrogenase activity, inhibition of oxygen uptake by KCN, amount of cytochrome transcripts), morphological changes (Transmission EM and light microscopy), and transformation experiments (loss of the Variant Surface Glycoprotein coat and increase of dihydroliponamide dehydrogenase activity). To further investigate the mechanisms responsible for these changes, microarray analyses were performed, showing an upregulation of expression site associated gene 8 (ESAG8), a potential differentiation regulator

Antitrypanosomal compounds from the essential oil and extracts of Keetia leucantha leaves with inhibitor activity on Trypanosoma brucei glyceraldehyde-3-phosphate dehydrogenase.

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Bero, J; Beaufay, C; Hannaert, V; Hérent, M-F; Michels, P A; Quetin-Leclercq, J

2013-02-15

Keetia leucantha is a West African tree used in traditional medicine to treat several diseases among which parasitic infections. The dichloromethane extract of leaves was previously shown to possess growth-inhibitory activities on Plasmodium falciparum, Trypanosoma brucei brucei and Leishmania mexicana mexicana with low or no cytotoxicity (>100 μg/ml on human normal fibroblasts) (Bero et al. 2009, 2011). In continuation of our investigations on the antitrypanosomal compounds from this dichloromethane extract, we analyzed by GC-FID and GC-MS the essential oil of its leaves obtained by hydrodistillation and the major triterpenic acids in this extract by LC-MS. Twenty-seven compounds were identified in the oil whose percentages were calculated using the normalization method. The essential oil, seven of its constituents and the three triterpenic acids were evaluated for their antitrypanosomal activity on Trypanosoma brucei brucei bloodstream forms (Tbb BSF) and procyclic forms (Tbb PF) to identify an activity on the glycolytic process of trypanosomes. The oil showed an IC(50) of 20.9 μg/ml on Tbb BSF and no activity was observed on Tbb PF. The best antitrypanosomal activity was observed for ursolic acid with IC(50) of 2.5 and 6.5 μg/ml respectively on Tbb BSF and Tbb PF. The inhibitory activity on a glycolytic enzyme of T. brucei, glyceraldehyde-3-phosphate dehydrogenase (GAPDH), was also evaluated for betulinic acid, olenaolic acid, ursolic acid, phytol, α-ionone and β-ionone. The three triterpenic acids and β-ionone showed inhibitory activities on GAPDH with oleanolic acid being the most active with an inhibition of 72.63% at 20 μg/ml. This paper reports for the first time the composition and antitrypanosomal activity of the essential oil of Keetia leucantha. Several of its constituents and three triterpenic acids present in the dichloromethane leaves extract showed a higher antitrypanosomal activity on bloodstream forms of Tbb as compared to procyclic forms

The γ-tubulin complex in Trypanosoma brucei: molecular composition, subunit interdependence and requirement for axonemal central pair protein assembly

Science.gov (United States)

Zhou, Qing; Li, Ziyin

2015-01-01

The γ-tubulin complex constitutes a key component of the microtubule-organizing center and nucleates microtubule assembly. This complex differs in complexity in different organisms: the budding yeast contains the γ-tubulin small complex (γTuSC) composed of γ-tubulin, GCP2 and GCP3, whereas animals contain the γ-tubulin ring complex (γTuRC) composed of γTuSC and three additional proteins, GCP4, GCP5 and GCP6. In Trypanosoma brucei, the composition of the γ-tubulin complex remains elusive, and it is not known whether it also regulates assembly of the subpellicular microtubules and the spindle microtubules. Here we report that the γ-tubulin complex in T. brucei is composed of γ-tubulin and three GCP proteins, GCP2-GCP4, and is primarily localized in the basal body throughout the cell cycle. Depletion of GCP2 and GCP3, but not GCP4, disrupted the axonemal central pair microtubules, but not the subpellicular microtubules and the spindle microtubules. Furthermore, we showed that the γTuSC is required for assembly of two central pair proteins and that γTuSC subunits are mutually required for stability. Together, these results identified an unusual γ-tubulin complex in T. brucei, uncovered an essential role of γTuSC in central pair protein assembly, and demonstrated the interdependence of individual γTuSC components for maintaining a stable complex. PMID:26224545

Peptide-targeted delivery of a pH sensor for quantitative measurements of intraglycosomal pH in live Trypanosoma brucei.

Science.gov (United States)

Lin, Sheng; Morris, Meredith T; Ackroyd, P Christine; Morris, James C; Christensen, Kenneth A

2013-05-28

Studies of dynamic changes in organelles of protozoan parasite Trypanosoma brucei have been limited, in part because of the difficulty of targeting analytical probes to specific subcellular compartments. Here we demonstrate application of a ratiometric probe for pH quantification in T. brucei glycosomes. The probe consists of a peptide encoding the peroxisomal targeting sequence (F-PTS1, acetyl-CKGGAKL) coupled to fluorescein, which responds to pH. When incubated with living parasites, the probe is internalized within vesicular structures that colocalize with a glycosomal marker. Inhibition of uptake of F-PTS1 at 4 °C and pulse-chase colocalization with fluorescent dextran suggested that the probe is initially taken up by non-receptor-mediated endocytosis but is subsequently transported separately from dextran and localized within glycosomes, prior to the final fusion of labeled glycosomes and lysosomes as part of glycosomal turnover. Intraorganellar measurements and pH calibration with F-PTS1 in T. brucei glycosomes indicate that the resting glycosomal pH under physiological conditions is 7.4 ± 0.2. However, incubation in glucose-depleted buffer triggered mild acidification of the glycosome over a period of 20 min, with a final observed pH of 6.8 ± 0.3. This glycosomal acidification was reversed by reintroduction of glucose. Coupling of ratiometric fluorescent sensors and reporters to PTS peptides offers an invaluable tool for monitoring in situ glycosomal response(s) to changing environmental conditions and could be applied to additional kinetoplastid parasites.

THE CYTOSOLIC AND GLYCOSOMAL GLYCERALDEHYDE-3-PHOSPHATE DEHYDROGENASE FROM TRYPANOSOMA-BRUCEI - KINETIC-PROPERTIES AND COMPARISON WITH HOMOLOGOUS ENZYMES

NARCIS (Netherlands)

LAMBEIR, AM; LOISEAU, AM; KUNTZ, DA; VELLIEUX, FM; MICHELS, PAM; OPPERDOES, FR

1991-01-01

The protozoan haemoflagellate Trypanosoma brucei has two NAD-dependent glyceraldehyde-3-phosphate dehydrogenase isoenzymes, each with a different localization within the cell. One isoenzyme is found in the cytosol, as in other eukaryotes, while the other is found in the glycosome, a microbody-like

The Chemical Characterization of Nigerian Propolis samples and Their Activity Against Trypanosoma brucei.

Science.gov (United States)

Omar, Ruwida; Igoli, John O; Zhang, Tong; Gray, Alexander I; Ebiloma, Godwin U; Clements, Carol J; Fearnley, James; Edrada Ebel, RuAngeli; Paget, Tim; de Koning, Harry P; Watson, David G

2017-04-19

Profiling of extracts from twelve propolis samples collected from eight regions in Nigeria was carried out using high performance liquid chromatography (LC) coupled with evaporative light scattering (ELSD), ultraviolet detection (UV) and mass spectrometry (MS), gas chromatography mass spectrometry (GC-MS) and nuclear magnetic resonance spectroscopy (NMR). Principal component analysis (PCA) of the processed LC-MS data demonstrated the varying chemical composition of the samples. Most of the samples were active against Trypanosoma b. brucei with the highest activity being in the samples from Southern Nigeria. The more active samples were fractionated in order to isolate the component(s) responsible for their activity using medium pressure liquid chromatography (MPLC). Three xanthones, 1,3,7-trihydroxy-2,8-di-(3-methylbut-2-enyl)xanthone, 1,3,7-trihydroxy-4,8-di-(3-methylbut-2-enyl)xanthone a previously undescribed xanthone and three triterpenes: ambonic acid, mangiferonic acid and a mixture of α-amyrin with mangiferonic acid (1:3) were isolated and characterised by NMR and LC-MS. These compounds all displayed strong inhibitory activity against T.b. brucei but none of them had higher activity than the crude extracts. Partial least squares (PLS) modelling of the anti-trypanosomal activity of the sample extracts using the LC-MS data indicated that high activity in the extracts, as judged from LCMS 2 data, could be correlated to denticulatain isomers in the extracts.

A haptoglobin-hemoglobin receptor conveys innate immunity to Trypanosoma brucei in humans

DEFF Research Database (Denmark)

Vanhollebeke, Benoit; De Muylder, Géraldine; Nielsen, Marianne J

2008-01-01

The protozoan parasite Trypanosoma brucei is lysed by apolipoprotein L-I, a component of human high-density lipoprotein (HDL) particles that are also characterized by the presence of haptoglobin-related protein. We report that this process is mediated by a parasite glycoprotein receptor, which...... binds the haptoglobin-hemoglobin complex with high affinity for the uptake and incorporation of heme into intracellular hemoproteins. In mice, this receptor was required for optimal parasite growth and the resistance of parasites to the oxidative burst by host macrophages. In humans, the trypanosome...... immunity against the parasite....

Role of interferon in resistance and immunity to protozoa

Science.gov (United States)

Sonnenfeld, G.; Degee, A. L. W.; Mansfield, J. M.; Newsome, A. L.; Arnold, R. R.

1985-01-01

Production of interferon (I) in response to protozoan infection, and the interferon-mediated inhibition of parasite replication were studied in order to determine if these effects may be related to immunologic-mediated resistance of the hosts. Two extracellular parasites-Trypanosoma brucei rhodesiense and Naegleria fowlei were used. Upon infection with the trypanosome, only resistant strains of mice produced I. An early peak of alpha/beta I is followed by appearance of gamma I, which coincided with antibody production and a drop in parasitemia. In case of the amoeba, pretreatment of its suspension with alpha/beta I inhibits its replication in vitro, and appears to protect mice from the infection and the disease. It is proposed that production of interferon, with its regulatory effect on the immune responses, may play a major role in regulating the processes of protozoan-caused diseases.

Mitochondrial tRNA import in Trypanosoma brucei is independent of thiolation and the Rieske protein

Czech Academy of Sciences Publication Activity Database

Paris, Zdeněk; RUBIO, M. A. T.; Lukeš, Julius; Alfonzo, J. D.

2009-01-01

Roč. 15, č. 7 (2009), s. 1398-1406 ISSN 1355-8382 R&D Projects: GA ČR GA204/06/1558; GA MŠk LC07032; GA MŠk 2B06129 Institutional research plan: CEZ:AV0Z60220518 Keywords : T. brucei * tRNA import * 2-thiolation * RIC * Rieske * Fe-S cluster Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 5.198, year: 2009

Mating compatibility in the parasitic protist Trypanosoma brucei.

Science.gov (United States)

Peacock, Lori; Ferris, Vanessa; Bailey, Mick; Gibson, Wendy

2014-02-21

Genetic exchange has been described in several kinetoplastid parasites, but the most well-studied mating system is that of Trypanosoma brucei, the causative organism of African sleeping sickness. Sexual reproduction takes place in the salivary glands (SG) of the tsetse vector and involves meiosis and production of haploid gametes. Few genetic crosses have been carried out to date and consequently there is little information about the mating compatibility of different trypanosomes. In other single-celled eukaryotes, mating compatibility is typically determined by a system of two or more mating types (MT). Here we investigated the MT system in T. brucei. We analysed a large series of F1, F2 and back crosses by pairwise co-transmission of red and green fluorescent cloned cell lines through experimental tsetse flies. To analyse each cross, trypanosomes were cloned from fly SG containing a mixture of both parents, and genotyped by microsatellites and molecular karyotype. To investigate mating compatibility at the level of individual cells, we directly observed the behaviour of SG-derived gametes in intra- or interclonal mixtures of red and green fluorescent trypanosomes ex vivo. Hybrid progeny were found in all F1 and F2 crosses and most of the back crosses. The success of individual crosses was highly variable as judged by the number of hybrid clones produced, suggesting a range of mating compatibilities among F1 progeny. As well as hybrids, large numbers of recombinant genotypes resulting from intraclonal mating (selfers) were found in some crosses. In ex vivo mixtures, red and green fluorescent trypanosome gametes were observed to pair up and interact via their flagella in both inter- and intraclonal combinations. While yellow hybrid trypanosomes were frequently observed in interclonal mixtures, such evidence of cytoplasmic exchange was rare in the intraclonal mixtures. The outcomes of individual crosses, particularly back crosses, were variable in numbers of both

Adaptations in the glucose metabolism of procyclic Trypanosoma brucei isolates from Tsetse flies and during differentiation of bloodstream forms.

NARCIS (Netherlands)

van Grinsven, K.W.A.; van den Abbeele, J.; van den Bossche, P.; van Hellemond, J.J.; Tielens, A.G.M.

2009-01-01

Procyclic forms of Trypanosoma brucei isolated from the midguts of infected tsetse flies, or freshly transformed from a strain that is close to field isolates, do not use a complete Krebs cycle. Furthermore, short stumpy bloodstream forms produce acetate and are apparently metabolically preadapted

Factors influencing passive surveillance for T. b. rhodesiense human african trypanosomiasis in Uganda.

Science.gov (United States)

Acup, Christine; Bardosh, Kevin Louis; Picozzi, Kim; Waiswa, Charles; Welburn, Susan Christina

2017-01-01

Sleeping sickness or Human African Trypanosomiasis (HAT) is a neglected tropical disease of public health importance across much of Sub-Saharan Africa. In Uganda, chronic T. b. gambiense HAT (gHAT) and acute T. b. rhodesiense HAT (rHAT) occur in two large but discrete geographical foci. Both forms are difficult to diagnose, expensive to treat and ultimately fatal in the absence of treatment. The area affected by zoonotic rHAT has been steadily expanding, placing a high burden on local health systems. HAT is a disease of neglected populations and is notorious for being under-reported. Here we examine the factors that influence passive rHAT surveillance within the district health system in four Ugandan districts into which the disease had recently been introduced, focusing on staff knowledge, infrastructure and data management. A mixed methods study was undertaken between 2011 and 2013 in Dokolo, Kaberamaido, Soroti and Serere districts to explore health facility capacity and clinical service provision, diagnostic capacity, HAT knowledge and case reporting. Structured interviews were undertaken with 86 medical personnel, including clinicians, nurses, midwives and technicians across 65 HC-II and HC-III medical facilities, where the health infrastructure was also directly observed. Eleven semi-structured interviews were undertaken with medical staff in each of the three designated HAT treatment facilities (Dokolo, Lwala and Serere HC-IV) in the area. HAT treatment centre case records, collected between 2009 and 2012, were analyzed. Most medical staff in HC-II and HC-III facilities had been made aware of HAT from radio broadcasts, newspapers and by word of mouth, suggestive of a lack of formal training. Key knowledge as regards the causative agent, clinical signs and that HAT drugs are provided free of charge was lower amongst HC-II than HC-III staff. Many respondents did not know whether HAT was endemic in their district. In rHAT specialist treatment centres, staff

KREX2 is not essential for either procyclic or bloodstream form Trypanosoma brucei.

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Jason Carnes

Full Text Available Most mitochondrial mRNAs in Trypanosoma brucei require RNA editing for maturation and translation. The edited RNAs primarily encode proteins of the oxidative phosphorylation system. These parasites undergo extensive changes in energy metabolism between the insect and bloodstream stages which are mirrored by alterations in RNA editing. Two U-specific exonucleases, KREX1 and KREX2, are both present in protein complexes (editosomes that catalyze RNA editing but the relative roles of each protein are not known.The requirement for KREX2 for RNA editing in vivo was assessed in both procyclic (insect and bloodstream form parasites by methods that use homologous recombination for gene elimination. These studies resulted in null mutant cells in which both alleles were eliminated. The viability of these cells demonstrates that KREX2 is not essential in either life cycle stage, despite certain defects in RNA editing in vivo. Furthermore, editosomes isolated from KREX2 null cells require KREX1 for in vitro U-specific exonuclease activity.KREX2 is a U-specific exonuclease that is dispensable for RNA editing in vivo in T. brucei BFs and PFs. This result suggests that the U deletion activity, which is required for RNA editing, is primarily mediated in vivo by KREX1 which is normally found associated with only one type of editosome. The retention of the KREX2 gene implies a non-essential role or a role that is essential in other life cycle stages or conditions.

Mitochondrial translation factors of Trypanosoma brucei: elongation factor-Tu has a unique subdomain that is essential for its function

Czech Academy of Sciences Publication Activity Database

Cristodero, M.; Mani, J.; Oeljeklaus, S.; Aeberhard, L.; Hashimi, Hassan; Ramrath, D.J.F.; Lukeš, Julius; Warscheid, B.; Schneider, A.

2013-01-01

Roč. 90, č. 4 (2013), s. 744-755 ISSN 0950-382X R&D Projects: GA ČR GAP305/12/2261 Institutional support: RVO:60077344 Keywords : mitochondrial translation * Trypanosoma brucei * EF-Tu Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 5.026, year: 2013

Constraints to estimating the prevalence of trypanosome infections in East African zebu cattle

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Cox Andrew P

2010-09-01

Full Text Available Abstract Background In East Africa, animal trypanosomiasis is caused by many tsetse transmitted protozoan parasites including Trypanosoma vivax, T. congolense and subspecies of T. brucei s.l. (T. b. brucei and zoonotic human infective T. b. rhodesiense that may co-circulate in domestic and wild animals. Accurate species-specific prevalence measurements of these parasites in animal populations are complicated by mixed infections of trypanosomes within individual hosts, low parasite densities and difficulties in conducting field studies. Many Polymerase Chain Reaction (PCR based diagnostic tools are available to characterise and quantify infection in animals. These are important for assessing the contribution of infections in animal reservoirs and the risk posed to humans from zoonotic trypanosome species. New matrices for DNA capture have simplified large scale field PCR analyses but few studies have examined the impact of these techniques on prevalence estimations. Results The Whatman FTA matrix has been evaluated using a random sample of 35 village zebu cattle from a population naturally exposed to trypanosome infection. Using a generic trypanosome-specific PCR, prevalence was systematically evaluated. Multiple PCR samples taken from single FTA cards demonstrated that a single punch from an FTA card is not sufficient to confirm the infectivity status of an individual animal as parasite DNA is unevenly distributed across the card. At low parasite densities in the host, this stochastic sampling effect results in underestimation of prevalence based on single punch PCR testing. Repeated testing increased the estimated prevalence of all Trypanosoma spp. from 9.7% to 86%. Using repeat testing, a very high prevalence of pathogenic trypanosomes was detected in these local village cattle: T. brucei (34.3%, T. congolense (42.9% and T. vivax (22.9%. Conclusions These results show that, despite the convenience of Whatman FTA cards and specific PCR based

Molecular Confirmation of Trypanosoma evansi and Babesia bigemina in Cattle from Lower Egypt

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Mahmoud M. Elhaig, Abdelfattah Selim, Mohamed M. Mahmoud and Eman K El-Gayar

2016-11-01

Full Text Available Trypanosomosis and babesiosis are economically important vector-borne diseases for animal health and productivity in developing countries. In Egypt, molecular epidemiological surveys on such diseases are scarce. In the present study, we examined 475 healthy and 25 clinically diagnosed cattle from three provinces in Lower Egypt, for Trypanosoma (T. and Babesia (B. infections using an ITS1 PCR assay that confirmed Trypanosoma species presence and an 18S rRNA assay that detected B. bigemina. Results confirmed Trypanosoma spp. and B. bigemina presence in 30.4% and 11% individuals, respectively, with eight animals (1.6% being co-infected with both hemoparasites. Subsequent type-specific PCRs revealed that all Trypanosoma PCR positive samples corresponded to T. evansi and that none of the animals harboured T. brucei gambiense or T. brucei rhodesiense. Nucleotide sequencing of the variable surface glycoprotein revealed the T. evansi cattle strain to be most closely related (99% nucleotide sequence identity to strains previously detected in dromedary camels in Egypt, while the 18S rRNA gene phylogeny confirmed the presence of a unique B. bigemina haplotype closely related to strains from Turkey and Brazil. Statistically significant differences in PCR prevalence were noted with respect to gender, clinical status and locality. These results confirm the presence of high numbers of carrier animals and signal the need for expanded surveillance and control efforts.

Protein functional links in Trypanosoma brucei, identified by gene fusion analysis

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Trimpalis Philip

2011-07-01

Full Text Available Abstract Background Domain or gene fusion analysis is a bioinformatics method for detecting gene fusions in one organism by comparing its genome to that of other organisms. The occurrence of gene fusions suggests that the two original genes that participated in the fusion are functionally linked, i.e. their gene products interact either as part of a multi-subunit protein complex, or in a metabolic pathway. Gene fusion analysis has been used to identify protein functional links in prokaryotes as well as in eukaryotic model organisms, such as yeast and Drosophila. Results In this study we have extended this approach to include a number of recently sequenced protists, four of which are pathogenic, to identify fusion linked proteins in Trypanosoma brucei, the causative agent of African sleeping sickness. We have also examined the evolution of the gene fusion events identified, to determine whether they can be attributed to fusion or fission, by looking at the conservation of the fused genes and of the individual component genes across the major eukaryotic and prokaryotic lineages. We find relatively limited occurrence of gene fusions/fissions within the protist lineages examined. Our results point to two trypanosome-specific gene fissions, which have recently been experimentally confirmed, one fusion involving proteins involved in the same metabolic pathway, as well as two novel putative functional links between fusion-linked protein pairs. Conclusions This is the first study of protein functional links in T. brucei identified by gene fusion analysis. We have used strict thresholds and only discuss results which are highly likely to be genuine and which either have already been or can be experimentally verified. We discuss the possible impact of the identification of these novel putative protein-protein interactions, to the development of new trypanosome therapeutic drugs.

Trypanosoma brucei TbIF1 inhibits the essential F1-ATPase in the infectious form of the parasite.

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Brian Panicucci

2017-04-01

Full Text Available The mitochondrial (mt FoF1-ATP synthase of the digenetic parasite, Trypanosoma brucei, generates ATP during the insect procyclic form (PF, but becomes a perpetual consumer of ATP in the mammalian bloodstream form (BF, which lacks a canonical respiratory chain. This unconventional dependence on FoF1-ATPase is required to maintain the essential mt membrane potential (Δψm. Normally, ATP hydrolysis by this rotary molecular motor is restricted to when eukaryotic cells experience sporadic hypoxic conditions, during which this compulsory function quickly depletes the cellular ATP pool. To protect against this cellular treason, the highly conserved inhibitory factor 1 (IF1 binds the enzyme in a manner that solely inhibits the hydrolytic activity. Intriguingly, we were able to identify the IF1 homolog in T. brucei (TbIF1, but determined that its expression in the mitochondrion is tightly regulated throughout the life cycle as it is only detected in PF cells. TbIF1 appears to primarily function as an emergency brake in PF cells, where it prevented the restoration of the Δψm by FoF1-ATPase when respiration was chemically inhibited. In vitro, TbIF1 overexpression specifically inhibits the hydrolytic activity but not the synthetic capability of the FoF1-ATP synthase in PF mitochondria. Furthermore, low μM amounts of recombinant TbIF1 achieve the same inhibition of total mt ATPase activity as the FoF1-ATPase specific inhibitors, azide and oligomycin. Therefore, even minimal ectopic expression of TbIF1 in BF cells proved lethal as the indispensable Δψm collapsed due to inhibited FoF1-ATPase. In summary, we provide evidence that T. brucei harbors a natural and potent unidirectional inhibitor of the vital FoF1-ATPase activity that can be exploited for future structure-based drug design.

Proximity Interactions among Basal Body Components in Trypanosoma brucei Identify Novel Regulators of Basal Body Biogenesis and Inheritance

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Hung Quang Dang

2017-01-01

Full Text Available The basal body shares similar architecture with centrioles in animals and is involved in nucleating flagellar axonemal microtubules in flagellated eukaryotes. The early-branching Trypanosoma brucei possesses a motile flagellum nucleated from the basal body that consists of a mature basal body and an adjacent pro-basal body. Little is known about the basal body proteome and its roles in basal body biogenesis and flagellar axoneme assembly in T. brucei. Here, we report the identification of 14 conserved centriole/basal body protein homologs and 25 trypanosome-specific basal body proteins. These proteins localize to distinct subdomains of the basal body, and several of them form a ring-like structure surrounding the basal body barrel. Functional characterization of representative basal body proteins revealed distinct roles in basal body duplication/separation and flagellar axoneme assembly. Overall, this work identified novel proteins required for basal body duplication and separation and uncovered new functions of conserved basal body proteins in basal body duplication and separation, highlighting an unusual mechanism of basal body biogenesis and inheritance in this early divergent eukaryote.

Diversity and spation distribution of vectors and hosts of T. brucei gambiense in forest zones of Southern Cameroon: Epidemiological implications

NARCIS (Netherlands)

Massussi, J.A.; Mbida Mbida, J.A.; Djieto-Lordon, C.; Njiokou, F.; Laveissière, C.; Ploeg, van der J.D.

2010-01-01

Host and vector distribution of Trypanosoma brucei gambiense was studied in relation to habitat types and seasons. Six (19.35%) of the 31 mammal species recorded in Bipindi were reservoir hosts. Cercopithecus nictitans was confined to the undisturbed forest and the low intensive shifting cultivation

Agrochemicals against malaria, sleeping sickness, leishmaniasis and Chagas disease.

Science.gov (United States)

Witschel, Matthias; Rottmann, Matthias; Kaiser, Marcel; Brun, Reto

2012-01-01

In tropical regions, protozoan parasites can cause severe diseases with malaria, leishmaniasis, sleeping sickness, and Chagas disease standing in the forefront. Many of the drugs currently being used to treat these diseases have been developed more than 50 years ago and can cause severe adverse effects. Above all, resistance to existing drugs is widespread and has become a serious problem threatening the success of control measures. In order to identify new antiprotozoal agents, more than 600 commercial agrochemicals have been tested on the pathogens causing the above mentioned diseases. For all of the pathogens, compounds were identified with similar or even higher activities than the currently used drugs in applied in vitro assays. Furthermore, in vivo activity was observed for the fungicide/oomyceticide azoxystrobin, and the insecticide hydramethylnon in the Plasmodium berghei mouse model, and for the oomyceticide zoxamide in the Trypanosoma brucei rhodesiense STIB900 mouse model, respectively.

Transcriptome Profiling of Trypanosoma brucei Development in the Tsetse Fly Vector Glossina morsitans.

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Amy F Savage

Full Text Available African trypanosomes, the causative agents of sleeping sickness in humans and nagana in animals, have a complex digenetic life cycle between a mammalian host and an insect vector, the blood-feeding tsetse fly. Although the importance of the insect vector to transmit the disease was first realized over a century ago, many aspects of trypanosome development in tsetse have not progressed beyond a morphological analysis, mainly due to considerable challenges to obtain sufficient material for molecular studies. Here, we used high-throughput RNA-Sequencing (RNA-Seq to profile Trypanosoma brucei transcript levels in three distinct tissues of the tsetse fly, namely the midgut, proventriculus and salivary glands. Consistent with current knowledge and providing a proof of principle, transcripts coding for procyclin isoforms and several components of the cytochrome oxidase complex were highly up-regulated in the midgut transcriptome, whereas transcripts encoding metacyclic VSGs (mVSGs and the surface coat protein brucei alanine rich protein or BARP were extremely up-regulated in the salivary gland transcriptome. Gene ontology analysis also supported the up-regulation of biological processes such as DNA metabolism and DNA replication in the proventriculus transcriptome and major changes in signal transduction and cyclic nucleotide metabolism in the salivary gland transcriptome. Our data highlight a small repertoire of expressed mVSGs and potential signaling pathways involving receptor-type adenylate cyclases and members of a surface carboxylate transporter family, called PADs (Proteins Associated with Differentiation, to cope with the changing environment, as well as RNA-binding proteins as a possible global regulators of gene expression.

Processing of the glycosomal matrix-protein import receptor PEX5 of Trypanosoma brucei

International Nuclear Information System (INIS)

Gualdrón-López, Melisa; Michels, Paul A.M.

2013-01-01

Highlights: ► Most eukaryotic cells have a single gene for the peroxin PEX5. ► PEX5 is sensitive to in vitro proteolysis in distantly related organisms. ► TbPEX5 undergoes N-terminal truncation in vitro and possibly in vivo. ► Truncated TbPEX5 is still capable of binding PTS1-containing proteins. ► PEX5 truncation is physiologically relevant or an evolutionary conserved artifact. -- Abstract: Glycolysis in kinetoplastid protists such as Trypanosoma brucei is compartmentalized in peroxisome-like organelles called glycosomes. Glycosomal matrix-protein import involves a cytosolic receptor, PEX5, which recognizes the peroxisomal-targeting signal type 1 (PTS1) present at the C-terminus of the majority of matrix proteins. PEX5 appears generally susceptible to in vitro proteolytic processing. On western blots of T. brucei, two PEX5 forms are detected with apparent M r of 100 kDa and 72 kDa. 5′-RACE-PCR showed that TbPEX5 is encoded by a unique transcript that can be translated into a protein of maximally 72 kDa. However, recombinant PEX5 migrates aberrantly in SDS–PAGE with an apparent M r of 100 kDa, similarly as observed for the native peroxin. In vitro protease susceptibility analysis of native and 35 S-labelled PEX5 showed truncation of the 100 kDa form at the N-terminal side by unknown parasite proteases, giving rise to the 72 kDa form which remains functional for PTS1 binding. The relevance of these observations is discussed

Processing of the glycosomal matrix-protein import receptor PEX5 of Trypanosoma brucei

Energy Technology Data Exchange (ETDEWEB)

Gualdrón-López, Melisa [Research Unit for Tropical Diseases, de Duve Institute, Université catholique de Louvain, Brussels (Belgium); Michels, Paul A.M., E-mail: paul.michels@uclouvain.be [Research Unit for Tropical Diseases, de Duve Institute, Université catholique de Louvain, Brussels (Belgium)

2013-02-01

Highlights: ► Most eukaryotic cells have a single gene for the peroxin PEX5. ► PEX5 is sensitive to in vitro proteolysis in distantly related organisms. ► TbPEX5 undergoes N-terminal truncation in vitro and possibly in vivo. ► Truncated TbPEX5 is still capable of binding PTS1-containing proteins. ► PEX5 truncation is physiologically relevant or an evolutionary conserved artifact. -- Abstract: Glycolysis in kinetoplastid protists such as Trypanosoma brucei is compartmentalized in peroxisome-like organelles called glycosomes. Glycosomal matrix-protein import involves a cytosolic receptor, PEX5, which recognizes the peroxisomal-targeting signal type 1 (PTS1) present at the C-terminus of the majority of matrix proteins. PEX5 appears generally susceptible to in vitro proteolytic processing. On western blots of T. brucei, two PEX5 forms are detected with apparent M{sub r} of 100 kDa and 72 kDa. 5′-RACE-PCR showed that TbPEX5 is encoded by a unique transcript that can be translated into a protein of maximally 72 kDa. However, recombinant PEX5 migrates aberrantly in SDS–PAGE with an apparent M{sub r} of 100 kDa, similarly as observed for the native peroxin. In vitro protease susceptibility analysis of native and {sup 35}S-labelled PEX5 showed truncation of the 100 kDa form at the N-terminal side by unknown parasite proteases, giving rise to the 72 kDa form which remains functional for PTS1 binding. The relevance of these observations is discussed.

Blocking variant surface glycoprotein synthesis alters endoplasmic reticulum exit sites/Golgi homeostasis in Trypanosoma brucei.

Science.gov (United States)

Ooi, Cher-Pheng; Smith, Terry K; Gluenz, Eva; Wand, Nadina Vasileva; Vaughan, Sue; Rudenko, Gloria

2018-06-01

The predominant secretory cargo of bloodstream form Trypanosoma brucei is variant surface glycoprotein (VSG), comprising ~10% total protein and forming a dense protective layer. Blocking VSG translation using Morpholino oligonucleotides triggered a precise pre-cytokinesis arrest. We investigated the effect of blocking VSG synthesis on the secretory pathway. The number of Golgi decreased, particularly in post-mitotic cells, from 3.5 ± 0.6 to 2.0 ± 0.04 per cell. Similarly, the number of endoplasmic reticulum exit sites (ERES) in post-mitotic cells dropped from 3.9 ± 0.6 to 2.7 ± 0.1 eight hours after blocking VSG synthesis. The secretory pathway was still functional in these stalled cells, as monitored using Cathepsin L. Rates of phospholipid and glycosylphosphatidylinositol-anchor biosynthesis remained relatively unaffected, except for the level of sphingomyelin which increased. However, both endoplasmic reticulum and Golgi morphology became distorted, with the Golgi cisternae becoming significantly dilated, particularly at the trans-face. Membrane accumulation in these structures is possibly caused by reduced budding of nascent vesicles due to the drastic reduction in the total amount of secretory cargo, that is, VSG. These data argue that the total flux of secretory cargo impacts upon the biogenesis and maintenance of secretory structures and organelles in T. brucei, including the ERES and Golgi. © 2018 The Authors. Traffic published by John Wiley & Sons Ltd.

Dynamics of Mitochondrial RNA-Binding Protein Complex in Trypanosoma brucei and Its Petite Mutant under Optimized Immobilization Conditions

Czech Academy of Sciences Publication Activity Database

Huang, Zhenqiu; Kaltenbrunner, S.; Šimková, Eva; Staněk, David; Lukeš, Julius; Hashimi, Hassan

2014-01-01

Roč. 13, č. 9 (2014), s. 1232-1240 ISSN 1535-9778 R&D Projects: GA ČR GAP305/12/2261; GA MŠk(CZ) EE2.3.30.0032 Institutional support: RVO:60077344 ; RVO:68378050 Keywords : mitochondrion * Trypanosoma brucei * YFP Subject RIV: EB - Genetics ; Molecular Biology; EB - Genetics ; Molecular Biology (UMG-J) Impact factor: 2.820, year: 2014

Exosome secretion affects social motility in Trypanosoma brucei.

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Dror Eliaz

2017-03-01

Full Text Available Extracellular vesicles (EV secreted by pathogens function in a variety of biological processes. Here, we demonstrate that in the protozoan parasite Trypanosoma brucei, exosome secretion is induced by stress that affects trans-splicing. Following perturbations in biogenesis of spliced leader RNA, which donates its spliced leader (SL exon to all mRNAs, or after heat-shock, the SL RNA is exported to the cytoplasm and forms distinct granules, which are then secreted by exosomes. The exosomes are formed in multivesicular bodies (MVB utilizing the endosomal sorting complexes required for transport (ESCRT, through a mechanism similar to microRNA secretion in mammalian cells. Silencing of the ESCRT factor, Vps36, compromised exosome secretion but not the secretion of vesicles derived from nanotubes. The exosomes enter recipient trypanosome cells. Time-lapse microscopy demonstrated that cells secreting exosomes or purified intact exosomes affect social motility (SoMo. This study demonstrates that exosomes are delivered to trypanosome cells and can change their migration. Exosomes are used to transmit stress signals for communication between parasites.

The Aurora Kinase in Trypanosoma brucei plays distinctive roles in metaphase-anaphase transition and cytokinetic initiation.

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Ziyin Li

2009-09-01

Full Text Available Aurora B kinase is an essential regulator of chromosome segregation with the action well characterized in eukaryotes. It is also implicated in cytokinesis, but the detailed mechanism remains less clear, partly due to the difficulty in separating the latter from the former function in a growing cell. A chemical genetic approach with an inhibitor of the enzyme added to a synchronized cell population at different stages of the cell cycle would probably solve this problem. In the deeply branched parasitic protozoan Trypanosoma brucei, an Aurora B homolog, TbAUK1, was found to control both chromosome segregation and cytokinetic initiation by evidence from RNAi and dominant negative mutation. To clearly separate these two functions, VX-680, an inhibitor of TbAUK1, was added to a synchronized T. brucei procyclic cell population at different cell cycle stages. The unique trans-localization pattern of the chromosomal passenger complex (CPC, consisting of TbAUK1 and two novel proteins TbCPC1 and TbCPC2, was monitored during mitosis and cytokinesis by following the migration of the proteins tagged with enhanced yellow fluorescence protein in live cells with time-lapse video microscopy. Inhibition of TbAUK1 function in S-phase, prophase or metaphase invariably arrests the cells in the metaphase, suggesting an action of TbAUK1 in promoting metaphase-anaphase transition. TbAUK1 inhibition in anaphase does not affect mitotic exit, but prevents trans-localization of the CPC from the spindle midzone to the anterior tip of the new flagellum attachment zone for cytokinetic initiation. The CPC in the midzone is dispersed back to the two segregated nuclei, while cytokinesis is inhibited. In and beyond telophase, TbAUK1 inhibition has no effect on the progression of cytokinesis or the subsequent G1, S and G2 phases until a new metaphase is attained. There are thus two clearly distinct points of TbAUK1 action in T. brucei: the metaphase-anaphase transition and

Challenges in the diagnosis and management of sleeping sickness in Tanzania: a case report.

Science.gov (United States)

Sindato, C; Kibona, S N; Nkya, G M; Mbilu, T J N K; Manga, C; Kaboya, J S; Rawille, F

2008-07-01

In Tanzania sleeping sickness presents a serious threat to human health with a country-wide average of 400 cases reported annually. Both wild and domestic animals have been found to play a significant role in the epidemiology of sleeping sickness. Serengeti National Park in northern Tanzania, has experienced a number of sleeping sickness epidemics since 1922. The epidemics were associated with abundant game animals in the areas and Glossina swynnertoni was incriminated as the main vector. However since 2001 there has been no case of sleeping sickness reported from the park. This case report highlights on the possibility of resurgence and challenges in the diagnosis and management of sleeping sickness in Serengeti. A 38 years old Tanzanian man working in the Serengeti National Park who had experienced various tsetse bites was presented with a febrile condition and history of unsuccessful case management at different health facilities. Blood and cerebrospinal fluid (CSF) samples were examined for the presence oftrypanosomes using wet film, Field's stain and concentration techniques. Typanosoma brucei rhodesiense were detected in both the blood and CSF samples. The patient was treated successfully with melarsoprol. The results of this case study highlight the possibility of resurgence of sleeping sickness in the park hence calls for the need to create more awareness among the community and clinicians. There is need for early reporting to health facility and strengthening the diagnostic capacity of healthcare facilities in and around national parks endemic for sleeping sickness.

Trypanosoma brucei TBRGG1, a mitochondrial oligo(U)-binding protein that co-localizes with an in vitro RNA editing activity

NARCIS (Netherlands)

Vanhamme, L.; Perez-Morga, D.; Marchal, C.; Speijer, D.; Lambert, L.; Geuskens, M.; Alexandre, S.; Ismaïli, N.; Göringer, U.; Benne, R.; Pays, E.

1998-01-01

We report the characterization of a Trypanosoma brucei 75-kDa protein of the RGG (Arg-Gly-Gly) type, termed TBRGG1. Dicistronic and monocistronic transcripts of the TBRGG1 gene were produced by both alternative splicing and polyadenylation. TBRGG1 was found in two or three forms that differ in their

Secondary Metabolites from Vietnamese Marine Invertebrates with Activity against Trypanosoma brucei and T. cruzi

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Nguyen Phuong Thao

2014-06-01

Full Text Available Marine-derived natural products from invertebrates comprise an extremely diverse and promising source of the compounds from a wide variety of structural classes. This study describes the discovery of five marine natural products with activity against Trypanosoma species by natural product library screening using whole cell in vitro assays. We investigated the anti-trypanosomal activity of the extracts from the soft corals and echinoderms living in Vietnamese seas. Of the samples screened, the methanolic extracts of several marine organisms exhibited potent activities against cultures of Trypanosoma brucei and T. cruzi (EC50 < 5.0 μg/mL. Among the compounds isolated from these extracts, laevigatol B (1 from Lobophytum crassum and L. laevigatum, (24S-ergost-4-ene-3-one (2 from Sinularia dissecta, astropectenol A (3 from Astropecten polyacanthus, and cholest-8-ene-3β,5α,6β,7α-tetraol (4 from Diadema savignyi showed inhibitory activity against T. brucei with EC50 values ranging from 1.57 ± 0.14 to 14.6 ± 1.36 μM, relative to the positive control, pentamidine (EC50 = 0.015 ± 0.003 μM. Laevigatol B (1 and 5α-cholest-8(14-ene-3β,7α-diol (5 exhibited also significant inhibitory effects on T. cruzi. The cytotoxic activity of the pure compounds on mammalian cells was also assessed and found to be insignificant in all cases. This is the first report on the inhibitory effects of marine organisms collected in Vietnamese seas against Trypanosoma species responsible for neglected tropical diseases.

Metabolic reprogramming during the Trypanosoma brucei life cycle [version 2; referees: 4 approved

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Terry K. Smith

2017-05-01

Full Text Available Cellular metabolic activity is a highly complex, dynamic, regulated process that is influenced by numerous factors, including extracellular environmental signals, nutrient availability and the physiological and developmental status of the cell. The causative agent of sleeping sickness, Trypanosoma brucei, is an exclusively extracellular protozoan parasite that encounters very different extracellular environments during its life cycle within the mammalian host and tsetse fly insect vector. In order to meet these challenges, there are significant alterations in the major energetic and metabolic pathways of these highly adaptable parasites. This review highlights some of these metabolic changes in this early divergent eukaryotic model organism.

Metabolic reprogramming during the Trypanosoma brucei life cycle [version 1; referees: 4 approved

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Terry K. Smith

2017-05-01

Full Text Available Cellular metabolic activity is a highly complex, dynamic, regulated process that is influenced by numerous factors, including extracellular environmental signals, nutrient availability and the physiological and developmental status of the cell. The causative agent of sleeping sickness, Trypanosoma brucei, is an exclusively extracellular protozoan parasite that encounters very different extracellular environments during its life cycle within the mammalian host and tsetse fly insect vector. In order to meet these challenges, there are significant alterations in the major energetic and metabolic pathways of these highly adaptable parasites. This review highlights some of these metabolic changes in this early divergent eukaryotic model organism.

Activity of D-carnitine and its derivatives on Trypanosoma infections in rats and mice

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Manganaro M.

2003-06-01

Full Text Available Little progress has been made in the treatment of African trypanosomiasis over the past decades. L-carnitine has a major role in glycolysis-based energy supply of blood trypanosomes for it stimulates constant ATP production. To investigate whether administration of the isomer D-carnitine could exert a competitive inhibition on the metabolic pathway of the L-form, possibily resulting in parasite replication inhibition, several formulations of this compound were tested on Trypanosoma lewisi and T. brucei rhodesiense in rodent models. High oral dosages of D-carnitine inner salt and proprionyl-D-carnitine were not toxic to animals and induced about 50 % parasite growth inhibition in reversible, i.e. competitive, fashion. A putative mechanism could be an interference in pyruvate kinase activity and hence ATP production. Considering both, lack of toxicity and inhibitory activity, D-carnitine may have a role in the treatment of African trypanosomiasis, in association with available trypanocidal drugs.

Trypanosoma brucei TbIF1 inhibits the essential Finf1/inf-ATPase in the infectious form of the parasite

Czech Academy of Sciences Publication Activity Database

Panicucci, Brian; Gahura, Ondřej; Zíková, Alena

2017-01-01

Roč. 11, č. 4 (2017), č. článku e0005552. ISSN 1935-2735 R&D Projects: GA MŠk(CZ) EE2.3.30.0032; GA ČR GA17-22248S; GA MŠk LL1205 Institutional support: RVO:60077344 Keywords : mt * TblF1 * Trypanosoma brucei Subject RIV: EE - Microbiology, Virology OBOR OECD: Infectious Diseases Impact factor: 3.834, year: 2016

Mosaic VSGs and the scale of Trypanosoma brucei antigenic variation.

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James P J Hall

Full Text Available A main determinant of prolonged Trypanosoma brucei infection and transmission and success of the parasite is the interplay between host acquired immunity and antigenic variation of the parasite variant surface glycoprotein (VSG coat. About 0.1% of trypanosome divisions produce a switch to a different VSG through differential expression of an archive of hundreds of silent VSG genes and pseudogenes, but the patterns and extent of the trypanosome diversity phenotype, particularly in chronic infection, are unclear. We applied longitudinal VSG cDNA sequencing to estimate variant richness and test whether pseudogenes contribute to antigenic variation. We show that individual growth peaks can contain at least 15 distinct variants, are estimated computationally to comprise many more, and that antigenically distinct 'mosaic' VSGs arise from segmental gene conversion between donor VSG genes or pseudogenes. The potential for trypanosome antigenic variation is probably much greater than VSG archive size; mosaic VSGs are core to antigenic variation and chronic infection.

Investigating the Chaperone Properties of a Novel Heat Shock Protein, Hsp70.c, from Trypanosoma brucei

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Adélle Burger

2014-01-01

Full Text Available The neglected tropical disease, African Trypanosomiasis, is fatal and has a crippling impact on economic development. Heat shock protein 70 (Hsp70 is an important molecular chaperone that is expressed in response to stress and Hsp40 acts as its co-chaperone. These proteins play a wide range of roles in the cell and they are required to assist the parasite as it moves from a cold blooded insect vector to a warm blooded mammalian host. A novel cytosolic Hsp70, from Trypanosoma brucei, TbHsp70.c, contains an acidic substrate binding domain and lacks the C-terminal EEVD motif. The ability of a cytosolic Hsp40 from Trypanosoma brucei J protein 2, Tbj2, to function as a co-chaperone of TbHsp70.c was investigated. The main objective was to functionally characterize TbHsp70.c to further expand our knowledge of parasite biology. TbHsp70.c and Tbj2 were heterologously expressed and purified and both proteins displayed the ability to suppress aggregation of thermolabile MDH and chemically denatured rhodanese. ATPase assays revealed a 2.8-fold stimulation of the ATPase activity of TbHsp70.c by Tbj2. TbHsp70.c and Tbj2 both demonstrated chaperone activity and Tbj2 functions as a co-chaperone of TbHsp70.c. In vivo heat stress experiments indicated upregulation of the expression levels of TbHsp70.c.

Characterization of a Novel Class I Transcription Factor A (CITFA) Subunit That Is Indispensable for Transcription by the Multifunctional RNA Polymerase I of Trypanosoma brucei

KAUST Repository

Nguyen, T. N.; Nguyen, B. N.; Lee, J. H.; Panigrahi, A. K.; Gunzl, A.

2012-01-01

Trypanosoma brucei is the only organism known to have evolved a multifunctional RNA polymerase I (pol I) system that is used to express the parasite's ribosomal RNAs, as well as its major cell surface antigens, namely, the variant surface

The 2’-O-ribose methyltransferase for cap 1 of spliced leader RNA and U1 small nuclear RNA in Trypanosoma brucei

Czech Academy of Sciences Publication Activity Database

Zamudio, J. R.; Mittra, B.; Foldynová-Trantírková, Silvie; Zeiner, G. M.; Lukeš, Julius; Bujnicki, J. M.; Sturm, N. R.; Campbell, D. A.

2007-01-01

Roč. 27, č. 17 (2007), s. 6084-6092 ISSN 0270-7306 R&D Projects: GA MŠk 2B06129; GA MŠk LC07032 Institutional research plan: CEZ:AV0Z60220518 Keywords : methylation * Trypanosoma brucei * methyltransferase * RNA interference Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 6.420, year: 2007

Dihydroquinazolines as a novel class of Trypanosoma brucei trypanothione reductase inhibitors: discovery, synthesis, and characterization of their binding mode by protein crystallography.

Science.gov (United States)

Patterson, Stephen; Alphey, Magnus S; Jones, Deuan C; Shanks, Emma J; Street, Ian P; Frearson, Julie A; Wyatt, Paul G; Gilbert, Ian H; Fairlamb, Alan H

2011-10-13

Trypanothione reductase (TryR) is a genetically validated drug target in the parasite Trypanosoma brucei , the causative agent of human African trypanosomiasis. Here we report the discovery, synthesis, and development of a novel series of TryR inhibitors based on a 3,4-dihydroquinazoline scaffold. In addition, a high resolution crystal structure of TryR, alone and in complex with substrates and inhibitors from this series, is presented. This represents the first report of a high resolution complex between a noncovalent ligand and this enzyme. Structural studies revealed that upon ligand binding the enzyme undergoes a conformational change to create a new subpocket which is occupied by an aryl group on the ligand. Therefore, the inhibitor, in effect, creates its own small binding pocket within the otherwise large, solvent exposed active site. The TryR-ligand structure was subsequently used to guide the synthesis of inhibitors, including analogues that challenged the induced subpocket. This resulted in the development of inhibitors with improved potency against both TryR and T. brucei parasites in a whole cell assay.

Independent Analysis of the Flagellum Surface and Matrix Proteomes Provides Insight into Flagellum Signaling in Mammalian-infectious Trypanosoma brucei*

Science.gov (United States)

Oberholzer, Michael; Langousis, Gerasimos; Nguyen, HoangKim T.; Saada, Edwin A.; Shimogawa, Michelle M.; Jonsson, Zophonias O.; Nguyen, Steven M.; Wohlschlegel, James A.; Hill, Kent L.

2011-01-01

The flagellum of African trypanosomes is an essential and multifunctional organelle that functions in motility, cell morphogenesis, and host-parasite interaction. Previous studies of the trypanosome flagellum have been limited by the inability to purify flagella without first removing the flagellar membrane. This limitation is particularly relevant in the context of studying flagellum signaling, as signaling requires surface-exposed proteins in the flagellar membrane and soluble signaling proteins in the flagellar matrix. Here we employ a combination of genetic and mechanical approaches to purify intact flagella from the African trypanosome, Trypanosoma brucei, in its mammalian-infectious stage. We combined flagellum purification with affinity-purification of surface-exposed proteins to conduct independent proteomic analyses of the flagellum surface and matrix fractions. The proteins identified encompass a broad range of molecular functionalities, including many predicted to function in signaling. Immunofluorescence and RNA interference studies demonstrate flagellum localization and function for proteins identified and provide insight into mechanisms of flagellum attachment and motility. The flagellum surface proteome includes many T. brucei-specific proteins and is enriched for proteins up-regulated in the mammalian-infectious stage of the parasite life-cycle. The combined results indicate that the flagellum surface presents a diverse and dynamic host-parasite interface that is well-suited for host-parasite signaling. PMID:21685506

Endogenous sterol biosynthesis is important for mitochondrial function and cell morphology in procyclic forms of Trypanosoma brucei.

Science.gov (United States)

Pérez-Moreno, Guiomar; Sealey-Cardona, Marco; Rodrigues-Poveda, Carlos; Gelb, Michael H; Ruiz-Pérez, Luis Miguel; Castillo-Acosta, Víctor; Urbina, Julio A; González-Pacanowska, Dolores

2012-10-01

Sterol biosynthesis inhibitors are promising entities for the treatment of trypanosomal diseases. Insect forms of Trypanosoma brucei, the causative agent of sleeping sickness, synthesize ergosterol and other 24-alkylated sterols, yet also incorporate cholesterol from the medium. While sterol function has been investigated by pharmacological manipulation of sterol biosynthesis, molecular mechanisms by which endogenous sterols influence cellular processes remain largely unknown in trypanosomes. Here we analyse by RNA interference, the effects of a perturbation of three specific steps of endogenous sterol biosynthesis in order to dissect the role of specific intermediates in proliferation, mitochondrial function and cellular morphology in procyclic cells. A decrease in the levels of squalene synthase and squalene epoxidase resulted in a depletion of cellular sterol intermediates and end products, impaired cell growth and led to aberrant morphologies, DNA fragmentation and a profound modification of mitochondrial structure and function. In contrast, cells deficient in sterol methyl transferase, the enzyme involved in 24-alkylation, exhibited a normal growth phenotype in spite of a complete abolition of the synthesis and content of 24-alkyl sterols. Thus, the data provided indicates that while the depletion of squalene and post-squalene endogenous sterol metabolites results in profound cellular defects, bulk 24-alkyl sterols are not strictly required to support growth in insect forms of T. brucei in vitro. Copyright © 2012 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.

TbPIF5 is a Trypanosoma brucei mitochondrial DNA helicase involved in processing of minicircle Okazaki fragments.

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Beiyu Liu

2009-09-01

Full Text Available Trypanosoma brucei's mitochondrial genome, kinetoplast DNA (kDNA, is a giant network of catenated DNA rings. The network consists of a few thousand 1 kb minicircles and several dozen 23 kb maxicircles. Here we report that TbPIF5, one of T. brucei's six mitochondrial proteins related to Saccharomyces cerevisiae mitochondrial DNA helicase ScPIF1, is involved in minicircle lagging strand synthesis. Like its yeast homolog, TbPIF5 is a 5' to 3' DNA helicase. Together with other enzymes thought to be involved in Okazaki fragment processing, TbPIF5 localizes in vivo to the antipodal sites flanking the kDNA. Minicircles in wild type cells replicate unidirectionally as theta-structures and are unusual in that Okazaki fragments are not joined until after the progeny minicircles have segregated. We now report that overexpression of TbPIF5 causes premature removal of RNA primers and joining of Okazaki fragments on theta structures. Further elongation of the lagging strand is blocked, but the leading strand is completed and the minicircle progeny, one with a truncated H strand (ranging from 0.1 to 1 kb, are segregated. The minicircles with a truncated H strand electrophorese on an agarose gel as a smear. This replication defect is associated with kinetoplast shrinkage and eventual slowing of cell growth. We propose that TbPIF5 unwinds RNA primers after lagging strand synthesis, thus facilitating processing of Okazaki fragments.

ent-Pimarane and ent-Kaurane Diterpenes from Aldama discolor (Asteraceae and Their Antiprotozoal Activity

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Mauro S. Nogueira

2016-09-01

Full Text Available Aldama discolor (syn.Viguiera discolor is an endemic Asteraceae from the Brazilian “Cerrado”, which has not previously been investigated for its chemical constituents and biological activity. Diterpenes are common secondary metabolites found in Aldama species, some of which have been reported to present potential antiprotozoal and antimicrobial activities. In this study, the known ent-3-α-hydroxy-kaur-16-en-18-ol (1, as well as three new diterpenes, namely, ent-7-oxo-pimara-8,15-diene-18-ol (2, ent-2S,4S-2-19-epoxy-pimara-8(3,15-diene-7β-ol (3 and ent-7-oxo-pimara-8,15-diene-3β-ol (4, were isolated from the dichloromethane extract of A. discolor leaves and identified by means of MS and NMR. The compounds were assayed in vitro against Trypanosoma brucei rhodesiense, T. cruzi and Leishmania donovani, Plasmodium falciparum and also tested for cytotoxicity against mammalian cells (L6 cell line. The ent-kaurane 1 showed significant in vitro activity against both P. falciparum (IC 50 = 3.5 μ M and L. donovani (IC 50 = 2.5 μ M and ent-pimarane 2 against P. falciparum (IC 50 = 3.8 μ M. Both compounds returned high selectivity indices (SI >10 in comparison with L6 cells, which makes them interesting candidates for in vivo tests. In addition to the diterpenes, the sesquiterpene lactone budlein A (5, which has been reported to possess a strong anti-T. b. rhodesiense activity, was identified as major compound in the A. discolor extract and explains its high activity against this parasite (100% growth inhibition at 2 μ g/mL.

Melarsoprol cyclodextrin inclusion complexes as promising oral candidates for the treatment of human African trypanosomiasis.

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Jean Rodgers

2011-09-01

Full Text Available Human African trypanosomiasis (HAT, or sleeping sickness, results from infection with the protozoan parasites Trypanosoma brucei (T. b. gambiense or T. b. rhodesiense and is invariably fatal if untreated. There are 60 million people at risk from the disease throughout sub-Saharan Africa. The infection progresses from the haemolymphatic stage where parasites invade the blood, lymphatics and peripheral organs, to the late encephalitic stage where they enter the central nervous system (CNS to cause serious neurological disease. The trivalent arsenical drug melarsoprol (Arsobal is the only currently available treatment for CNS-stage T. b. rhodesiense infection. However, it must be administered intravenously due to the presence of propylene glycol solvent and is associated with numerous adverse reactions. A severe post-treatment reactive encephalopathy occurs in about 10% of treated patients, half of whom die. Thus melarsoprol kills 5% of all patients receiving it. Cyclodextrins have been used to improve the solubility and reduce the toxicity of a wide variety of drugs. We therefore investigated two melarsoprol cyclodextrin inclusion complexes; melarsoprol hydroxypropyl-β-cyclodextrin and melarsoprol randomly-methylated-β-cyclodextrin. We found that these compounds retain trypanocidal properties in vitro and cure CNS-stage murine infections when delivered orally, once per day for 7-days, at a dosage of 0.05 mmol/kg. No overt signs of toxicity were detected. Parasite load within the brain was rapidly reduced following treatment onset and magnetic resonance imaging showed restoration of normal blood-brain barrier integrity on completion of chemotherapy. These findings strongly suggest that complexed melarsoprol could be employed as an oral treatment for CNS-stage HAT, delivering considerable improvements over current parenteral chemotherapy.

ent-Pimarane and ent-Kaurane Diterpenes from Aldama discolor (Asteraceae) and Their Antiprotozoal Activity.

Science.gov (United States)

Nogueira, Mauro S; Da Costa, Fernando B; Brun, Reto; Kaiser, Marcel; Schmidt, Thomas J

2016-09-15

Aldama discolor (syn.Viguiera discolor) is an endemic Asteraceae from the Brazilian "Cerrado", which has not previously been investigated for its chemical constituents and biological activity. Diterpenes are common secondary metabolites found in Aldama species, some of which have been reported to present potential antiprotozoal and antimicrobial activities. In this study, the known ent-3-α-hydroxy-kaur-16-en-18-ol (1), as well as three new diterpenes, namely, ent-7-oxo-pimara-8,15-diene-18-ol (2), ent-2S,4S-2-19-epoxy-pimara-8(3),15-diene-7β-ol (3) and ent-7-oxo-pimara-8,15-diene-3β-ol (4), were isolated from the dichloromethane extract of A. discolor leaves and identified by means of MS and NMR. The compounds were assayed in vitro against Trypanosoma brucei rhodesiense, T. cruzi and Leishmania donovani, Plasmodium falciparum and also tested for cytotoxicity against mammalian cells (L6 cell line). The ent-kaurane 1 showed significant in vitro activity against both P. falciparum (IC 50 = 3.5 μ M) and L. donovani (IC 50 = 2.5 μ M) and ent-pimarane 2 against P. falciparum (IC 50 = 3.8 μ M). Both compounds returned high selectivity indices (SI >10) in comparison with L6 cells, which makes them interesting candidates for in vivo tests. In addition to the diterpenes, the sesquiterpene lactone budlein A (5), which has been reported to possess a strong anti-T. b. rhodesiense activity, was identified as major compound in the A. discolor extract and explains its high activity against this parasite (100% growth inhibition at 2 μ g/mL).

Spatial distribution and trypanosome infection of tsetse flies in the sleeping sickness focus of Zimbabwe in Hurungwe District

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William Shereni

2016-11-01

Full Text Available Abstract Background In Zimbabwe, cases of human African trypanosomiasis (HAT are caused by the unicellular protozoan Trypanosoma brucei, sub-species T. b. rhodesiense. They are reported from the tsetse-infested area in the northern part of the country, broadly corresponding to the valley of the Zambezi River. Tsetse-transmitted trypanosomes, in particular T. congolense and T. vivax, also cause morbidity and mortality in livestock, thus generating poverty and food insecurity. Two species of tsetse fly, Glossina morsistans morsitans and G. pallidipes, are known to be present in the Zambezi Valley, although their distributional patterns and densities have not been investigated in detail. The present study tries to address this gap by providing some insight into the dynamics of trypanosomiasis in humans and livestock. Methods Tsetse distribution and trypanosome infections were studied using traps and fixed fly rounds located at 10 km intervals along a 110 km long transect straddling the southern escarpment of the Zambezi Valley. Three km long fly rounds were conducted on 12 sites, and were repeated 11 times over a 7-month period. Additional traps were deployed and monitored in selected sites. Microscopic examination of 2092 flies for trypanosome infections was conducted. Results Surveys confirmed the presence of G. morsitans morsitans and G. pallidipes in the Zambezi Valley floor. Moving south, the apparent density of tsetse flies appears to peak in the vicinity of the escarpment, then drops on the highlands. Only one fly was caught south of the old game fence separating protected and settled areas. A trypanosome infection rate of 6.31% was recorded in tsetse flies dissected. Only one infection of the T. brucei-type was detected. Conclusions Tsetse fly distribution in the study area appears to be driven by ecological factors such as variation in land use and altitude-mediated climatic patterns. Although targeted control of tsetse flies have played

The miRNA and mRNA Signatures of Peripheral Blood Cells in Humans Infected with Trypanosoma brucei gambiense.

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Smiths Lueong

Full Text Available Simple, reliable tools for diagnosis of human African Trypanosomiases could ease field surveillance and enhance patient care. In particular, current methods to distinguish patients with (stage II and without (stage I brain involvement require samples of cerebrospinal fluid. We describe here an exploratory study to find out whether miRNAs from peripheral blood leukocytes might be useful in diagnosis of human trypanosomiasis, or for determining the stage of the disease. Using microarrays, we measured miRNAs in samples from Trypanosoma brucei gambiense-infected patients (9 stage I, 10 stage II, 8 seronegative parasite-negative controls and 12 seropositive, but parasite-negative subjects. 8 miRNAs (out of 1205 tested showed significantly lower expression in patients than in seronegative, parasite-negative controls, and 1 showed increased expression. There were no clear differences in miRNAs between patients in different disease stages. The miRNA profiles could not distinguish seropositive, but parasitologically negative samples from controls and results within this group did not correlate with those from the trypanolysis test. Some of the regulated miRNAs, or their predicted mRNA targets, were previously reported changed during other infectious diseases or cancer. We conclude that the changes in miRNA profiles of peripheral blood lymphocytes in human African trypanosomiasis are related to immune activation or inflammation, are probably disease-non-specific, and cannot be used to determine the disease stage. The approach has little promise for diagnostics but might yield information about disease pathology.

Effect of experimental single Ancylostoma caninum and mixed infections of Trypanosoma brucei and Trypanosoma congolense on the humoural immune response to anti-rabies vaccination in dogs

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Nwoha Rosemary Ijeoma Ogechi

2015-06-01

Full Text Available Objective: To determine the effect of Ancylostoma caninum (A. caninum and trypanosome parasites on the immune response to vaccination in dogs in endemic environments. Methods: Sixteen dogs for the experiment were grouped into 4 of 4 members each. Group I was the uninfected control one, and GPII was infected with A. caninum; GPIII was infected with A. caninum/Trypanosoma congolense (T. congolense, and GPIV was infected with Trypanosoma brucei (T. brucei/A. caninum. The dogs were first vaccinated with antirabies vaccine before infecting GPII, GPIII and GPIV with A. caninum which were done 4 weeks after vaccination. By 2-week post-vaccination, trypanosome parasites were superimposed on both GPIII and GPIV. A secondary vaccination was given to GPI, GPII, GPIII, and GPIV by Week 12 of the experiment (4 weeks post treatment. Results: The prepatent period was (3.00 ± 1.40 days, in the conjunct infection of T. brucei/ A. caninum. It was (9.00 ± 1.10 days, in conjunct T. congolense/A. caninum. The prepatent period of A. caninum was (14.0 ± 2.0 days in the single A. caninum group and (13.0 ± 1.0 days in the conjunct trypanosome/A. caninum. At the 1st week after vaccination, the antibody titer in all the vaccinated groups (GPI, GPII, GPIII, and GPIV significantly increased (P < 0.05 and peaked at the 3rd week after vaccination. Following infections, there were marked significant decreases (P < 0.05 in the antibody production against rabies in GPII, GPIII and GPIV. The significant decrease (P < 0.05 in antibody titer was highest in the conjunct groups (GPIII and GPIV compared to the single infection (GPII. Treatment with diminazene aceturate and mebendazole did not significantly improve antibody response in the dogs. A secondary vaccination administered at the 12th week after the primary vaccination significantly increased (P < 0.05 the antibody titer with a peak at the 3rd week after the secondary vaccination. Conclusions: It was therefore concluded

Cancer in the parasitic protozoans Trypanosoma brucei and Toxoplasma gondii.

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Lun, Zhao-Rong; Lai, De-Hua; Wen, Yan-Zi; Zheng, Ling-Ling; Shen, Ji-Long; Yang, Ting-Bo; Zhou, Wen-Liang; Qu, Liang-Hu; Hide, Geoff; Ayala, Francisco J

2015-07-21

Cancer is a general name for more than 100 malignant diseases. It is postulated that all cancers start from a single abnormal cell that grows out of control. Untreated cancers can cause serious consequences and deaths. Great progress has been made in cancer research that has significantly improved our knowledge and understanding of the nature and mechanisms of the disease, but the origins of cancer are far from being well understood due to the limitations of suitable model systems and to the complexities of the disease. In view of the fact that cancers are found in various species of vertebrates and other metazoa, here, we suggest that cancer also occurs in parasitic protozoans such as Trypanosoma brucei, a blood parasite, and Toxoplasma gondii, an obligate intracellular pathogen. Without treatment, these protozoan cancers may cause severe disease and death in mammals, including humans. The simpler genomes of these single-cell organisms, in combination with their complex life cycles and fascinating life cycle differentiation processes, may help us to better understand the origins of cancers and, in particular, leukemias.

Megazol and its bioisostere 4H-1,2,4-triazole: comparing the trypanocidal, cytotoxic and genotoxic activities and their in vitro and in silico interactions with the Trypanosoma brucei nitroreductase enzyme

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Alcione Silva de Carvalho

2014-06-01

Full Text Available Megazol (7 is a 5-nitroimidazole that is highly active against Trypanosoma cruzi and Trypanosoma brucei, as well as drug-resistant forms of trypanosomiasis. Compound 7 is not used clinically due to its mutagenic and genotoxic properties, but has been largely used as a lead compound. Here, we compared the activity of 7 with its 4H-1,2,4-triazole bioisostere (8 in bloodstream forms of T. brucei and T. cruzi and evaluated their activation by T. brucei type I nitroreductase (TbNTR enzyme. We also analysed the cytotoxic and genotoxic effects of these compounds in whole human blood using Comet and fluorescein diacetate/ethidium bromide assays. Although the only difference between 7 and 8 is the substitution of sulphur (in the thiadiazole in 7 for nitrogen (in the triazole in 8, the results indicated that 8 had poorer antiparasitic activity than 7 and was not genotoxic, whereas 7 presented this effect. The determination of Vmax indicated that although 8 was metabolised more rapidly than 7, it bounds to the TbNTR with better affinity, resulting in equivalent kcat/KM values. Docking assays of 7 and 8 performed within the active site of a homology model of the TbNTR indicating that 8 had greater affinity than 7.

Sleep and rhythm changes at the time of Trypanosoma brucei invasion of the brain parenchyma in the rat.

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Seke Etet, Paul F; Palomba, Maria; Colavito, Valeria; Grassi-Zucconi, Gigliola; Bentivoglio, Marina; Bertini, Giuseppe

2012-05-01

Human African trypanosomiasis (HAT), or sleeping sickness, is a severe disease caused by Trypanosoma brucei (T.b.). The disease hallmark is sleep alterations. Brain involvement in HAT is a crucial pathogenetic step for disease diagnosis and therapy. In this study, a rat model of African trypanosomiasis was used to assess changes of sleep-wake, rest-activity, and body temperature rhythms in the time window previously shown as crucial for brain parenchyma invasion by T.b. to determine potential biomarkers of this event. Chronic radiotelemetric monitoring in Sprague-Dawley rats was used to continuously record electroencephalogram, electromyogram, rest-activity, and body temperature in the same animals before (baseline recording) and after infection. Rats were infected with T.b. brucei. Data were acquired from 1 to 20 d after infection (parasite neuroinvasion initiates at 11-13 d post-infection in this model), and were compared to baseline values. Sleep parameters were manually scored from electroencephalographic-electromyographic tracings. Circadian rhythms of sleep time, slow-wave activity, rest-activity, and body temperature were studied using cosinor rhythmometry. Results revealed alterations of most of the analyzed parameters. In particular, sleep pattern and sleep-wake organization plus rest-activity and body temperature rhythms exhibited early quantitative and qualitative alterations, which became marked around the time interval crucial for parasite neuroinvasion or shortly after. Data derived from actigrams showed close correspondence with those from hypnograms, suggesting that rest-activity could be useful to monitor sleep-wake alterations in African trypanosomiasis.

RNA-Seq analysis validates the use of culture-derived Trypanosoma brucei and provides new markers for mammalian and insect life-cycle stages.

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Naguleswaran, Arunasalam; Doiron, Nicholas; Roditi, Isabel

2018-04-02

Trypanosoma brucei brucei, the parasite causing Nagana in domestic animals, is closely related to the parasites causing sleeping sickness, but does not infect humans. In addition to its importance as a pathogen, the relative ease of genetic manipulation and an innate capacity for RNAi extend its use as a model organism in cell and infection biology. During its development in its mammalian and insect (tsetse fly) hosts, T. b. brucei passes through several different life-cycle stages. There are currently four life-cycle stages that can be cultured: slender forms and stumpy forms, which are equivalent to forms found in the mammal, and early and late procyclic forms, which are equivalent to forms in the tsetse midgut. Early procyclic forms show coordinated group movement (social motility) on semi-solid surfaces, whereas late procyclic forms do not. RNA-Seq was performed on biological replicates of each life-cycle stage. These constitute the first datasets for culture-derived slender and stumpy bloodstream forms and early and late procyclic forms. Expression profiles confirmed that genes known to be stage-regulated in the animal and insect hosts were also regulated in culture. Sequence reads of 100-125 bases provided sufficient precision to uncover differential expression of closely related genes. More than 100 transcripts showed peak expression in stumpy forms, including adenylate cyclases and several components of inositol metabolism. Early and late procyclic forms showed differential expression of 73 transcripts, a number of which encoded proteins that were previously shown to be stage-regulated. Moreover, two adenylate cyclases previously shown to reduce social motility are up-regulated in late procyclic forms. This study validates the use of cultured bloodstream forms as alternatives to animal-derived parasites and yields new markers for all four stages. In addition to underpinning recent findings that early and late procyclic forms are distinct life-cycle stages

Solid phase synthesis and antiprotozoal evaluation of di- and trisubstituted 5'-carboxamidoadenosine analogues.

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Rodenko, Boris; Detz, Remko J; Pinas, Victorine A; Lambertucci, Catia; Brun, Reto; Wanner, Martin J; Koomen, Gerrit-Jan

2006-03-01

The rapid increase of resistance to drugs commonly used in the treatment of tropical diseases such as malaria and African sleeping sickness calls for the prompt development of new safe and efficacious drugs. The pathogenic protozoan parasites lack the capability of synthesising purines de novo and they take up preformed purines from their host through various transmembrane transporters. Adenosine derivatives constitute a class of potential therapeutics due to their selective internalisation by these transporters. Automated solid-phase synthesis can speed up the process of lead finding and we pursued the solid-phase synthesis of di- and trisubstituted 5'-carboxamidoadenosine derivatives by using a safety-catch approach. While efforts with Kenner's sulfonamide linker remained fruitless, successful application of the hydrazide safety-catch linker allowed the construction of two representative combinatorial libraries. Their antiprotozoal evaluation identified two compounds with promising activity: N(6)-benzyl-5'-N-phenylcarboxamidoadenosine with an IC(50) value of 0.91 microM against Trypanosoma brucei rhodesiense and N(6)-diphenylethyl-5'-phenylcarboxamidoadenosine with an IC(50) value of 1.8 microM against chloroquine resistant Plasmodium falciparum.

Meiosis and haploid gametes in the pathogen Trypanosoma brucei.

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Peacock, Lori; Bailey, Mick; Carrington, Mark; Gibson, Wendy

2014-01-20

In eukaryote pathogens, sex is an important driving force in spreading genes for drug resistance, pathogenicity, and virulence. For the parasitic trypanosomes that cause African sleeping sickness, mating occurs during transmission by the tsetse vector and involves meiosis, but haploid gametes have not yet been identified. Here, we show that meiosis is a normal part of development in the insect salivary glands for all subspecies of Trypanosoma brucei, including the human pathogens. By observing insect-derived trypanosomes during the window of peak expression of meiosis-specific genes, we identified promastigote-like (PL) cells that interacted with each other via their flagella and underwent fusion, as visualized by the mixing of cytoplasmic red and green fluorescent proteins. PL cells had a short, wide body, a very long anterior flagellum, and either one or two kinetoplasts, but only the anterior kinetoplast was associated with the flagellum. Measurement of nuclear DNA contents showed that PL cells were haploid relative to diploid metacyclics. Trypanosomes are among the earliest diverging eukaryotes, and our results support the hypothesis that meiosis and sexual reproduction are ubiquitous in eukaryotes and likely to have been early innovations. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

Channel-forming activities in the glycosomal fraction from the bloodstream form of Trypanosoma brucei.

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Melisa Gualdron-López

Full Text Available BACKGROUND: Glycosomes are a specialized form of peroxisomes (microbodies present in unicellular eukaryotes that belong to the Kinetoplastea order, such as Trypanosoma and Leishmania species, parasitic protists causing severe diseases of livestock and humans in subtropical and tropical countries. The organelles harbour most enzymes of the glycolytic pathway that is responsible for substrate-level ATP production in the cell. Glycolysis is essential for bloodstream-form Trypanosoma brucei and enzymes comprising this pathway have been validated as drug targets. Glycosomes are surrounded by a single membrane. How glycolytic metabolites are transported across the glycosomal membrane is unclear. METHODS/PRINCIPAL FINDINGS: We hypothesized that glycosomal membrane, similarly to membranes of yeast and mammalian peroxisomes, contains channel-forming proteins involved in the selective transfer of metabolites. To verify this prediction, we isolated a glycosomal fraction from bloodstream-form T. brucei and reconstituted solubilized membrane proteins into planar lipid bilayers. The electrophysiological characteristics of the channels were studied using multiple channel recording and single channel analysis. Three main channel-forming activities were detected with current amplitudes 70-80 pA, 20-25 pA, and 8-11 pA, respectively (holding potential +10 mV and 3.0 M KCl as an electrolyte. All channels were in fully open state in a range of voltages ±150 mV and showed no sub-conductance transitions. The channel with current amplitude 20-25 pA is anion-selective (P(K+/P(Cl-∼0.31, while the other two types of channels are slightly selective for cations (P(K+/P(Cl- ratios ∼1.15 and ∼1.27 for the high- and low-conductance channels, respectively. The anion-selective channel showed an intrinsic current rectification that may suggest a functional asymmetry of the channel's pore. CONCLUSIONS/SIGNIFICANCE: These results indicate that the membrane of glycosomes

Early invasion of brain parenchyma by African trypanosomes.

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Ute Frevert

Full Text Available Human African trypanosomiasis or sleeping sickness is a vector-borne parasitic disease that has a major impact on human health and welfare in sub-Saharan countries. Based mostly on data from animal models, it is currently thought that trypanosome entry into the brain occurs by initial infection of the choroid plexus and the circumventricular organs followed days to weeks later by entry into the brain parenchyma. However, Trypanosoma brucei bloodstream forms rapidly cross human brain microvascular endothelial cells in vitro and appear to be able to enter the murine brain without inflicting cerebral injury. Using a murine model and intravital brain imaging, we show that bloodstream forms of T. b. brucei and T. b. rhodesiense enter the brain parenchyma within hours, before a significant level of microvascular inflammation is detectable. Extravascular bloodstream forms were viable as indicated by motility and cell division, and remained detectable for at least 3 days post infection suggesting the potential for parasite survival in the brain parenchyma. Vascular inflammation, as reflected by leukocyte recruitment and emigration from cortical microvessels, became apparent only with increasing parasitemia at later stages of the infection, but was not associated with neurological signs. Extravascular trypanosomes were predominantly associated with postcapillary venules suggesting that early brain infection occurs by parasite passage across the neuroimmunological blood brain barrier. Thus, trypanosomes can invade the murine brain parenchyma during the early stages of the disease before meningoencephalitis is fully established. Whether individual trypanosomes can act alone or require the interaction from a quorum of parasites remains to be shown. The significance of these findings for disease development is now testable.

The orthologue of Sjögren's syndrome nuclear autoantigen 1 (SSNA1 in Trypanosoma brucei is an immunogenic self-assembling molecule.

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Helen P Price

Full Text Available Primary Sjögren's Syndrome (PSS is a highly prevalent autoimmune disease, typically manifesting as lymphocytic infiltration of the exocrine glands leading to chronically impaired lacrimal and salivary secretion. Sjögren's Syndrome nuclear autoantigen 1 (SSNA1 or NA14 is a major specific target for autoantibodies in PSS but the precise function and clinical relevance of this protein are largely unknown. Orthologues of the gene are absent from many of the commonly used model organisms but are present in Chlamyodomonas reinhardtii (in which it has been termed DIP13 and most protozoa. We report the functional characterisation of the orthologue of SSNA1 in the kinetoplastid parasite, Trypanosoma brucei. Both TbDIP13 and human SSNA1 are small coiled-coil proteins which are predicted to be remote homologues of the actin-binding protein tropomyosin. We use comparative proteomic methods to identify potential interacting partners of TbDIP13. We also show evidence that TbDIP13 is able to self-assemble into fibril-like structures both in vitro and in vivo, a property which may contribute to its immunogenicity. Endogenous TbDIP13 partially co-localises with acetylated α-tubulin in the insect procyclic stage of the parasite. However, deletion of the DIP13 gene in cultured bloodstream and procyclic stages of T. brucei has little effect on parasite growth or morphology, indicating either a degree of functional redundancy or a function in an alternative stage of the parasite life cycle.

Enhanced succinic acid production in Aspergillus saccharolyticus by heterologous expression of fumarate reductase from Trypanosoma brucei

DEFF Research Database (Denmark)

Yang, Lei; Lübeck, Mette; Ahring, Birgitte K.

2015-01-01

production medium as well as the complete medium, but the measured enzyme activities were different depending on the media. Furthermore, a soluble NADH-dependent fumarate reductase gene (frd) from Trypanosoma brucei was inserted and expressed in A. saccharolyticus. The expression of the frd gene led......Aspergillus saccharolyticus exhibits great potential as a cell factory for industrial production of dicarboxylic acids. In the analysis of the organic acid profile, A. saccharolyticus was cultivated in an acid production medium using two different pH conditions. The specific activities...... of the enzymes, pyruvate carboxylase (PYC), malate dehydrogenase (MDH), and fumarase (FUM), involved in the reductive tricarboxylic acid (rTCA) branch, were examined and compared in cells harvested from the acid production medium and a complete medium. The results showed that ambient pH had a significant impact...

Bifurcatriol, a New Antiprotozoal Acyclic Diterpene from the Brown Alga Bifurcaria bifurcata

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Vangelis Smyrniotopoulos

2017-08-01

Full Text Available Linear diterpenes that are commonly found in brown algae are of high chemotaxonomic and ecological importance. This study reports bifurcatriol (1, a new linear diterpene featuring two stereogenic centers isolated from the Irish brown alga Bifurcaria bifurcata. The gross structure of this new natural product was elucidated based on its spectroscopic data (IR, 1D and 2D-NMR, HRMS. Its absolute configuration was identified by experimental and computational vibrational circular dichroism (VCD spectroscopy, combined with the calculation of 13C-NMR chemical shielding constants. Bifurcatriol (1 was tested for in vitro antiprotozoal activity towards a small panel of parasites (Plasmodium falciparum, Trypanosoma brucei rhodesiense, T. cruzi, and Leishmania donovani and cytotoxicity against mammalian primary cells. The highest activity was exerted against the malaria parasite P. falciparum (IC50 value 0.65 μg/mL with low cytotoxicity (IC50 value 56.6 μg/mL. To our knowledge, this is the first successful application of VCD and DP4 probability analysis of the calculated 13C-NMR chemical shifts for the simultaneous assignment of the absolute configuration of multiple stereogenic centers in a long-chain acyclic natural product.

RNA interference analyses suggest a transcript-specific regulatory role for mitochondrial RNA-binding proteins MRP1 and MRP2 in RNA editing and other RNA processing in Trypanosoma brucei

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Vondrusková, Eva; van den Burg, Janny; Zíková, Alena; Ernst, Nancy Lewis; Stuart, Kenneth; Benne, Rob; Lukes, Julius

2005-01-01

Mitochondrial RNA-binding proteins MRP1 and MRP2 occur in a heteromeric complex that appears to play a role in U-insertion/deletion editing in trypanosomes. Reduction in the levels of MRP1 (gBP21) and/or MRP2 (gBP25) mRNA by RNA interference in procyclic Trypanosoma brucei resulted in severe growth

Alba-domain proteins of Trypanosoma brucei are cytoplasmic RNA-binding proteins that interact with the translation machinery.

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Jan Mani

Full Text Available Trypanosoma brucei and related pathogens transcribe most genes as polycistronic arrays that are subsequently processed into monocistronic mRNAs. Expression is frequently regulated post-transcriptionally by cis-acting elements in the untranslated regions (UTRs. GPEET and EP procyclins are the major surface proteins of procyclic (insect midgut forms of T. brucei. Three regulatory elements common to the 3' UTRs of both mRNAs regulate mRNA turnover and translation. The glycerol-responsive element (GRE is unique to the GPEET 3' UTR and regulates its expression independently from EP. A synthetic RNA encompassing the GRE showed robust sequence-specific interactions with cytoplasmic proteins in electromobility shift assays. This, combined with column chromatography, led to the identification of 3 Alba-domain proteins. RNAi against Alba3 caused a growth phenotype and reduced the levels of Alba1 and Alba2 proteins, indicative of interactions between family members. Tandem-affinity purification and co-immunoprecipitation verified these interactions and also identified Alba4 in sub-stoichiometric amounts. Alba proteins are cytoplasmic and are recruited to starvation granules together with poly(A RNA. Concomitant depletion of all four Alba proteins by RNAi specifically reduced translation of a reporter transcript flanked by the GPEET 3' UTR. Pulldown of tagged Alba proteins confirmed interactions with poly(A binding proteins, ribosomal protein P0 and, in the case of Alba3, the cap-binding protein eIF4E4. In addition, Alba2 and Alba3 partially cosediment with polyribosomes in sucrose gradients. Alba-domain proteins seem to have exhibited great functional plasticity in the course of evolution. First identified as DNA-binding proteins in Archaea, then in association with nuclear RNase MRP/P in yeast and mammalian cells, they were recently described as components of a translationally silent complex containing stage-regulated mRNAs in Plasmodium. Our results are

Spliced leader RNA silencing (SLS - a programmed cell death pathway in Trypanosoma brucei that is induced upon ER stress

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Michaeli Shulamit

2012-05-01

Full Text Available Abstract Trypanosoma brucei is the causative agent of African sleeping sickness. The parasite cycles between its insect (procyclic form and mammalian hosts (bloodstream form. Trypanosomes lack conventional transcription regulation, and their genes are transcribed in polycistronic units that are processed by trans-splicing and polyadenylation. In trans-splicing, which is essential for processing of each mRNA, an exon, the spliced leader (SL is added to all mRNAs from a small RNA, the SL RNA. Trypanosomes lack the machinery for the unfolded protein response (UPR, which in other eukaryotes is induced under endoplasmic reticulum (ER stress. Trypanosomes respond to such stress by changing the stability of mRNAs, which are essential for coping with the stress. However, under severe ER stress that is induced by blocking translocation of proteins to the ER, treatment of cells with chemicals that induce misfolding in the ER, or extreme pH, trypanosomes elicit the spliced leader silencing (SLS pathway. In SLS, the transcription of the SL RNA gene is extinguished, and tSNAP42, a specific SL RNA transcription factor, fails to bind to its cognate promoter. SLS leads to complete shut-off of trans-splicing. In this review, I discuss the UPR in mammals and compare it to the ER stress response in T. brucei leading to SLS. I summarize the evidence supporting the notion that SLS is a programmed cell death (PCD pathway that is utilized by the parasites to substitute for the apoptosis observed in higher eukaryotes under prolonged ER stress. I present the hypothesis that SLS evolved to expedite the death process, and rapidly remove from the population unfit parasites that, by elimination via SLS, cause minimal damage to the parasite population.

Sleeping sickness in travelers - do they really sleep?

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Karin Urech

2011-11-01

Full Text Available The number of imported Human African Trypanosomiasis (HAT cases in non-endemic countries has increased over the last years. The objective of this analysis is to describe the clinical presentation of HAT in Caucasian travelers. Literature was screened (MEDLINE, Pubmed using the terms "Human African Trypanosomiasis", "travelers" and "expatriates"; all European languages except Slavic ones were included. Publications without clinical description of patients were only included in the epidemiological analysis. Forty-five reports on Caucasians with T.b. rhodesiense and 15 with T.b. gambiense infections were included in the analysis of the clinical parameters. Both species have presented with fever (T.b. rhodesiense 97.8% and T.b. gambiense 93.3%, headache (50% each and a trypanosomal chancre (T.b. rhodesiense 84.4%, T.b. gambiense 46.7%. While sleeping disorders dominate the clinical presentation of HAT in endemic regions, there have been only rare reports in travelers: insomnia (T.b. rhodesiense 7.1%, T.b. gambiense 21.4%, diurnal somnolence (T.b. rhodesiense 4.8%, T.b. gambiense none. Surprisingly, jaundice has been seen in 24.2% of the Caucasian T.b. rhodesiense patients, but has never been described in HAT patients in endemic regions. These results contrast to the clinical presentation of T.b. gambiense and T.b. rhodesiense HAT in Africans in endemic regions, where the presentation of chronic T.b. gambiense and acute T.b. rhodesiense HAT is different. The analysis of 14 reports on T.b. gambiense HAT in Africans living in a non-endemic country shows that neurological symptoms such as somnolence (46.2%, motor deficit (64.3% and reflex anomalies (14.3% as well as psychiatric symptoms such as hallucinations (21.4% or depression (21.4% may dominate the clinical picture. Often, the diagnosis has been missed initially: some patients have even been hospitalized in psychiatric clinics. In travelers T.b. rhodesiense and gambiense present as acute illnesses

Overproduction, purification, crystallization and preliminary X-ray diffraction analysis of Trypanosoma brucei gambiense glycerol kinase

International Nuclear Information System (INIS)

Balogun, Emmanuel Oluwadare; Inaoka, Daniel Ken; Kido, Yasutoshi; Shiba, Tomoo; Nara, Takeshi; Aoki, Takashi; Honma, Teruki; Tanaka, Akiko; Inoue, Masayuki; Matsuoka, Shigeru; Michels, Paul A. M.; Harada, Shigeharu; Kita, Kiyoshi

2010-01-01

Glycerol kinase from human African trypanosomes has been purified and crystallized for X-ray structure analysis. In the bloodstream forms of human trypanosomes, glycerol kinase (GK; EC 2.7.1.30) is one of the nine glycosomally compartmentalized enzymes that are essential for energy metabolism. In this study, a recombinant Trypanosoma brucei gambiense GK (rTbgGK) with an N-terminal cleavable His 6 tag was overexpressed, purified to homogeneity and crystallized by the sitting-drop vapour-diffusion method using PEG 400 as a precipitant. A complete X-ray diffraction data set to 2.75 Å resolution indicated that the crystals belonged to the orthorhombic space group P2 1 2 1 2 1 , with unit-cell parameters a = 63.84, b = 121.50, c = 154.59 Å. The presence of two rTbgGK molecules in the asymmetric unit gives a Matthews coefficient (V M ) of 2.5 Å 3 Da −1 , corresponding to 50% solvent content

Comparative analysis of the kinomes of three pathogenic trypanosomatids: Leishmania major, Trypanosoma brucei and Trypanosoma cruzi

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Ward Pauline N

2005-09-01

Full Text Available Abstract Background The trypanosomatids Leishmania major, Trypanosoma brucei and Trypanosoma cruzi cause some of the most debilitating diseases of humankind: cutaneous leishmaniasis, African sleeping sickness, and Chagas disease. These protozoa possess complex life cycles that involve development in mammalian and insect hosts, and a tightly coordinated cell cycle ensures propagation of the highly polarized cells. However, the ways in which the parasites respond to their environment and coordinate intracellular processes are poorly understood. As a part of an effort to understand parasite signaling functions, we report the results of a genome-wide analysis of protein kinases (PKs of these three trypanosomatids. Results Bioinformatic searches of the trypanosomatid genomes for eukaryotic PKs (ePKs and atypical PKs (aPKs revealed a total of 176 PKs in T. brucei, 190 in T. cruzi and 199 in L. major, most of which are orthologous across the three species. This is approximately 30% of the number in the human host and double that of the malaria parasite, Plasmodium falciparum. The representation of various groups of ePKs differs significantly as compared to humans: trypanosomatids lack receptor-linked tyrosine and tyrosine kinase-like kinases, although they do possess dual-specificity kinases. A relative expansion of the CMGC, STE and NEK groups has occurred. A large number of unique ePKs show no strong affinity to any known group. The trypanosomatids possess few ePKs with predicted transmembrane domains, suggesting that receptor ePKs are rare. Accessory Pfam domains, which are frequently present in human ePKs, are uncommon in trypanosomatid ePKs. Conclusion Trypanosomatids possess a large set of PKs, comprising approximately 2% of each genome, suggesting a key role for phosphorylation in parasite biology. Whilst it was possible to place most of the trypanosomatid ePKs into the seven established groups using bioinformatic analyses, it has not been

Differential Editosome Protein Function between Life Cycle Stages of Trypanosoma brucei.

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McDermott, Suzanne M; Guo, Xuemin; Carnes, Jason; Stuart, Kenneth

2015-10-09

Uridine insertion and deletion RNA editing generates functional mitochondrial mRNAs in Trypanosoma brucei. The mRNAs are differentially edited in bloodstream form (BF) and procyclic form (PF) life cycle stages, and this correlates with the differential utilization of glycolysis and oxidative phosphorylation between the stages. The mechanism that controls this differential editing is unknown. Editing is catalyzed by multiprotein ∼20S editosomes that contain endonuclease, 3'-terminal uridylyltransferase, exonuclease, and ligase activities. These editosomes also contain KREPB5 and KREPA3 proteins, which have no functional catalytic motifs, but they are essential for parasite viability, editing, and editosome integrity in BF cells. We show here that repression of KREPB5 or KREPA3 is also lethal in PF, but the effects on editosome structure differ from those in BF. In addition, we found that point mutations in KREPB5 or KREPA3 differentially affect cell growth, editosome integrity, and RNA editing between BF and PF stages. These results indicate that the functions of KREPB5 and KREPA3 editosome proteins are adjusted between the life cycle stages. This implies that these proteins are involved in the processes that control differential editing and that the 20S editosomes differ between the life cycle stages. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

Trypanosoma brucei gambiense trypanosomiasis in Terego county, northern Uganda, 1996: a lot quality assurance sampling survey.

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Hutin, Yvan J F; Legros, Dominique; Owini, Vincent; Brown, Vincent; Lee, Evan; Mbulamberi, Dawson; Paquet, Christophe

2004-04-01

We estimated the pre-intervention prevalence of Trypanosoma brucei gambiense (Tbg) trypanosomiasis using the lot quality assurance sampling (LQAS) methods in 14 parishes of Terego County in northern Uganda. A total of 826 participants were included in the survey sample in 1996. The prevalence of laboratory confirmed Tbg trypanosomiasis adjusted for parish population sizes was 2.2% (95% confidence interval =1.1-3.2). This estimate was consistent with the 1.1% period prevalence calculated on the basis of cases identified through passive and active screening in 1996-1999. Ranking of parishes in four categories according to LQAS analysis of the 1996 survey predicted the prevalences observed during the first round of active screening in the population in 1997-1998 (P LQAS were validated by the results of the population screening, suggesting that these survey methods may be useful in the pre-intervention phase of sleeping sickness control programs.

Structures of Trypanosoma brucei methionyl-tRNA synthetase with urea-based inhibitors provide guidance for drug design against sleeping sickness.

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Cho Yeow Koh

2014-04-01

Full Text Available Methionyl-tRNA synthetase of Trypanosoma brucei (TbMetRS is an important target in the development of new antitrypanosomal drugs. The enzyme is essential, highly flexible and displaying a large degree of changes in protein domains and binding pockets in the presence of substrate, product and inhibitors. Targeting this protein will benefit from a profound understanding of how its structure adapts to ligand binding. A series of urea-based inhibitors (UBIs has been developed with IC50 values as low as 19 nM against the enzyme. The UBIs were shown to be orally available and permeable through the blood-brain barrier, and are therefore candidates for development of drugs for the treatment of late stage human African trypanosomiasis. Here, we expand the structural diversity of inhibitors from the previously reported collection and tested for their inhibitory effect on TbMetRS and on the growth of T. brucei cells. The binding modes and binding pockets of 14 UBIs are revealed by determination of their crystal structures in complex with TbMetRS at resolutions between 2.2 Å to 2.9 Å. The structures show binding of the UBIs through conformational selection, including occupancy of the enlarged methionine pocket and the auxiliary pocket. General principles underlying the affinity of UBIs for TbMetRS are derived from these structures, in particular the optimum way to fill the two binding pockets. The conserved auxiliary pocket might play a role in binding tRNA. In addition, a crystal structure of a ternary TbMetRS•inhibitor•AMPPCP complex indicates that the UBIs are not competing with ATP for binding, instead are interacting with ATP through hydrogen bond. This suggests a possibility that a general 'ATP-engaging' binding mode can be utilized for the design and development of inhibitors targeting tRNA synthetases of other disease-causing pathogen.

Glycolipid precursors for the membrane anchor of Trypanosoma brucei variant surface glycoproteins. II. Lipid structures of phosphatidylinositol-specific phospholipase C sensitive and resistant glycolipids

International Nuclear Information System (INIS)

Mayor, S.; Menon, A.K.; Cross, G.A.

1990-01-01

A common diagnostic feature of glycosylinositol phospholipid (GPI)-anchored proteins is their release from the membrane by a phosphatidylinositol-specific phospholipase C (PI-PLC). However, some GPI-anchored proteins are resistant to this enzyme. The best characterized example of this subclass is the human erythrocyte acetylcholinesterase, where the structural basis of PI-PLC resistance has been shown to be the acylation of an inositol hydroxyl group(s). Both PI-PLC-sensitive and resistant GPI-anchor precursors (P2 and P3, respectively) have been found in Trypanosoma brucei, where the major surface glycoprotein is anchored by a PI-PLC-sensitive glycolipid anchor. The accompanying paper shows that P2 and P3 have identical glycans, indistinguishable from the common core glycan found on all the characterized GPI protein anchors. This paper shows that the single difference between P2 and P3, and the basis for the PI-PLC insusceptibility of P3, is a fatty acid, ester-linked to the inositol residue in P3. The inositol-linked fatty acid can be removed by treatment with mild base to restore PI-PLC sensitivity. Biosynthetic labeling experiments with [3H]palmitic acid and [3H]myristic acid show that [3H]palmitic acid specifically labels the inositol residue in P3 while [3H]myristic acid labels the diacylglycerol portion. Possible models to account for the simultaneous presence of PI-PLC-resistant and sensitive glycolipids are discussed in the context of available information on the biosynthesis of GPI-anchors

Flux Analysis of the Trypanosoma brucei Glycolysis Based on a Multiobjective-Criteria Bioinformatic Approach

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Amine Ghozlane

2012-01-01

Full Text Available Trypanosoma brucei is a protozoan parasite of major of interest in discovering new genes for drug targets. This parasite alternates its life cycle between the mammal host(s (bloodstream form and the insect vector (procyclic form, with two divergent glucose metabolism amenable to in vitro culture. While the metabolic network of the bloodstream forms has been well characterized, the flux distribution between the different branches of the glucose metabolic network in the procyclic form has not been addressed so far. We present a computational analysis (called Metaboflux that exploits the metabolic topology of the procyclic form, and allows the incorporation of multipurpose experimental data to increase the biological relevance of the model. The alternatives resulting from the structural complexity of networks are formulated as an optimization problem solved by a metaheuristic where experimental data are modeled in a multiobjective function. Our results show that the current metabolic model is in agreement with experimental data and confirms the observed high metabolic flexibility of glucose metabolism. In addition, Metaboflux offers a rational explanation for the high flexibility in the ratio between final products from glucose metabolism, thsat is, flux redistribution through the malic enzyme steps.

2-Alkynoic fatty acids inhibit topoisomerase IB from Leishmania donovani.

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Carballeira, Néstor M; Cartagena, Michelle; Sanabria, David; Tasdemir, Deniz; Prada, Christopher F; Reguera, Rosa M; Balaña-Fouce, Rafael

2012-10-01

2-Alkynoic fatty acids display antimycobacterial, antifungal, and pesticidal activities but their antiprotozoal activity has received little attention. In this work we synthesized the 2-octadecynoic acid (2-ODA), 2-hexadecynoic acid (2-HDA), and 2-tetradecynoic acid (2-TDA) and show that 2-ODA is the best inhibitor of the Leishmania donovani DNA topoisomerase IB enzyme (LdTopIB) with an EC(50)=5.3±0.7μM. The potency of LdTopIB inhibition follows the trend 2-ODA>2-HDA>2-TDA, indicating that the effectiveness of inhibition depends on the fatty acid carbon chain length. All of the studied 2-alkynoic fatty acids were less potent inhibitors of the human topoisomerase IB enzyme (hTopIB) as compared to LdTopIB. 2-ODA also displayed in vitro activity against Leishmania donovani (IC(50)=11.0μM), but it was less effective against other protozoa, Trypanosoma cruzi (IC(50)=48.1μM) and Trypanosoma brucei rhodesiense (IC(50)=64.5μM). The antiprotozoal activity of the 2-alkynoic fatty acids, in general, followed the trend 2-ODA>2-HDA>2-TDA. The experimental information gathered so far indicates that 2-ODA is a promising antileishmanial compound. Copyright © 2012 Elsevier Ltd. All rights reserved.

Trypanosoma brucei Inhibition by Essential Oils from Medicinal and Aromatic Plants Traditionally Used in Cameroon (Azadirachta indica, Aframomum melegueta, Aframomum daniellii, Clausena anisata, Dichrostachys cinerea and Echinops giganteus).

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Kamte, Stephane L Ngahang; Ranjbarian, Farahnaz; Campagnaro, Gustavo Daniel; Nya, Prosper C Biapa; Mbuntcha, Hélène; Woguem, Verlaine; Womeni, Hilaire Macaire; Ta, Léon Azefack; Giordani, Cristiano; Barboni, Luciano; Benelli, Giovanni; Cappellacci, Loredana; Hofer, Anders; Petrelli, Riccardo; Maggi, Filippo

2017-07-06

Essential oils are complex mixtures of volatile components produced by the plant secondary metabolism and consist mainly of monoterpenes and sesquiterpenes and, to a minor extent, of aromatic and aliphatic compounds. They are exploited in several fields such as perfumery, food, pharmaceutics, and cosmetics. Essential oils have long-standing uses in the treatment of infectious diseases and parasitosis in humans and animals. In this regard, their therapeutic potential against human African trypanosomiasis (HAT) has not been fully explored. In the present work, we have selected six medicinal and aromatic plants ( Azadirachta indica , Aframomum melegueta , Aframomum daniellii , Clausena anisata , Dichrostachys cinerea , and Echinops giganteus ) traditionally used in Cameroon to treat several disorders, including infections and parasitic diseases, and evaluated the activity of their essential oils against Trypanosma brucei TC221. Their selectivity was also determined with Balb/3T3 (mouse embryonic fibroblast cell line) cells as a reference. The results showed that the essential oils from A. indica , A . daniellii , and E. giganteus were the most active ones, with half maximal inhibitory concentration (IC 50 ) values of 15.21, 7.65, and 10.50 µg/mL, respectively. These essential oils were characterized by different chemical compounds such as sesquiterpene hydrocarbons, monoterpene hydrocarbons, and oxygenated sesquiterpenes. Some of their main components were assayed as well on T. brucei TC221, and their effects were linked to those of essential oils.

Methanolic leaf extract of Moringa oleifera improves the survivability rate, weight gain and histopathological changes of Wister rats infected with Trypanosoma brucei

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A. Aremu

2018-04-01

Full Text Available Trypanosomosis is a major disease of Man and animals. This study investigated the effect of Moringa oleifera leaf extract on the survivability rate, weight gain and histopathological changes of Wister rats experimentally infected with Trypanosoma brucei. A total of thirty (30 rats randomly divided into six groups (A-F. Rats in group A remain untreated and uninfected while rates in group F were infected and untreated. Rats in groups B and C were treated with Moringa oleifera leave extract orally at 200 mg/kg for 14 days pre-infection and the treatment continued in B but not in C. Rats in groups D and E were treated with the extract orally for ninety days at 200 mg/kg (pre-infection and the treatment continued in D but not in E. The weight changes in all rats were monitored weekly. Rats in B-F groups were infected with 3 × 106 of Trypanosoma brucei per mL of blood. The results showed that all the infected rats died but the treated group survived extra two days when compared with the untreated group. The percentage weight gain of rats in groups B and C was high (23.9% and 21.1% respectively as against negative control (17.2%. The groups with chronic administration of the extract (D and E had a lower percentage weight gains (64.3% and 60.3% respectively when compared with negative control (71.8%. The histopathology results showed that the extract was a potent ameliorative agent that reduced neuronal degeneration and congestion in the brain and the spleen of the infected rats respectively. In conclusion, Moringa Oleifera leave extract has mitigative effects on the pathogenesis of trypanosomosis. Keywords: Histopathology, Moringa, Survivability, Trypanosoma, Weight, Wister rats

Development of Trypanosomosis Agglutination Card Test (TACT ...

African Journals Online (AJOL)

In a bid to improve field diagnosis of animal trypanosomosis in tsetse-infested African countries, TACT utilizing fixed and stabilized procyclic antigen from culture-derived Trypanosoma brucei gambiense isolate IL2343 was developed and evaluated in Uganda. Its diagnostic sensitivity was evaluated using blood samples ...

Characterization of a Novel Class I Transcription Factor A (CITFA) Subunit That Is Indispensable for Transcription by the Multifunctional RNA Polymerase I of Trypanosoma brucei

KAUST Repository

Nguyen, T. N.

2012-10-26

Trypanosoma brucei is the only organism known to have evolved a multifunctional RNA polymerase I (pol I) system that is used to express the parasite\\'s ribosomal RNAs, as well as its major cell surface antigens, namely, the variant surface glycoprotein (VSG) and procyclin, which are vital for establishing successful infections in the mammalian host and the tsetse vector, respectively. Thus far, biochemical analyses of the T. brucei RNA pol I transcription machinery have elucidated the subunit structure of the enzyme and identified the class I transcription factor A (CITFA). CITFA binds to RNA pol I promoters, and its CITFA-2 subunit was shown to be absolutely essential for RNA pol I transcription in the parasite. Tandem affinity purification (TAP) of CITFA revealed the subunits CITFA-1 to -6, which are conserved only among kinetoplastid organisms, plus the dynein light chain DYNLL1. Here, by tagging CITFA-6 instead of CITFA-2, a complex was purified that contained all known CITFA subunits, as well as a novel proline-rich protein. Functional studies carried out in vivo and in vitro, as well as a colocalization study, unequivocally demonstrated that this protein is a bona fide CITFA subunit, essential for parasite viability and indispensable for RNA pol I transcription of ribosomal gene units and the active VSG expression site in the mammalian-infective life cycle stage of the parasite. Interestingly, CITFA-7 function appears to be species specific, because expression of an RNA interference (RNAi)-resistant CITFA-7 transgene from Trypanosoma cruzi could not rescue the lethal phenotype of silencing endogenous CITFA-7.

A role for Sar1 and ARF1 GTPases during Golgi biogenesis in the protozoan parasite Trypanosoma brucei

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Yavuz, Sevil; Warren, Graham

2017-01-01

A single Golgi stack is duplicated and partitioned into two daughter cells during the cell cycle of the protozoan parasite Trypanosoma brucei. The source of components required to generate the new Golgi and the mechanism by which it forms are poorly understood. Using photoactivatable GFP, we show that the existing Golgi supplies components directly to the newly forming Golgi in both intact and semipermeabilized cells. The movement of a putative glycosyltransferase, GntB, requires the Sar1 and ARF1 GTPases in intact cells. In addition, we show that transfer of GntB from the existing Golgi to the new Golgi can be recapitulated in semipermeabilized cells and is sensitive to the GTP analogue GTPγS. We suggest that the existing Golgi is a key source of components required to form the new Golgi and that this process is regulated by small GTPases. PMID:28495798

Cell-cycle synchronisation of bloodstream forms of Trypanosoma brucei using Vybrant DyeCycle Violet-based sorting.

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Kabani, Sarah; Waterfall, Martin; Matthews, Keith R

2010-01-01

Studies on the cell-cycle of Trypanosoma brucei have revealed several unusual characteristics that differ from the model eukaryotic organisms. However, the inability to isolate homogenous populations of parasites in distinct cell-cycle stages has limited the analysis of trypanosome cell division and complicated the understanding of mutant phenotypes with possible impact on cell-cycle related events. Although hydroxyurea-induced cell-cycle arrest in procyclic and bloodstream forms has been applied recently with success, such block-release protocols can complicate the analysis of cell-cycle regulated events and have the potential to disrupt important cell-cycle checkpoints. An alternative approach based on flow cytometry of parasites stained with Vybrant DyeCycle Orange circumvents this problem, but is restricted to procyclic form parasites. Here, we apply Vybrant Dyecycle Violet staining coupled with flow cytometry to effectively select different cell-cycle stages of bloodstream form trypanosomes. Moreover, the sorted parasites remain viable, although synchrony is rapidly lost. This method enables cell-cycle enrichment of populations of trypanosomes in their mammal infective stage, particularly at the G1 phase.

Wild chimpanzees are infected by Trypanosoma brucei

Czech Academy of Sciences Publication Activity Database

Jirků, M.; Votýpka, J.; Petrželková, Klára Judita; Jirků-Pomajbíková, K.; Kriegová, E.; Vodička, R.; Lankester, F.; Leendertz, S. A. J.; Wittig, R. M.; Boesch, C.; Modrý, D.; Ayala, F. J.; Leendertz, F. H.; Lukeš, J.

2015-01-01

Roč. 4, č. 3 (2015), s. 277-282 ISSN 0020-7519 Institutional support: RVO:68081766 Keywords : Trypanosomes * Chimpanzee * Non-human primates * Transmission * Diagnostics Subject RIV: EG - Zoology Impact factor: 4.242, year: 2015

Quinolone Amides as Antitrypanosomal Lead Compounds with In Vivo Activity.

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Hiltensperger, Georg; Hecht, Nina; Kaiser, Marcel; Rybak, Jens-Christoph; Hoerst, Alexander; Dannenbauer, Nicole; Müller-Buschbaum, Klaus; Bruhn, Heike; Esch, Harald; Lehmann, Leane; Meinel, Lorenz; Holzgrabe, Ulrike

2016-08-01

Human African trypanosomiasis (HAT) is a major tropical disease for which few drugs for treatment are available, driving the need for novel active compounds. Recently, morpholino-substituted benzyl amides of the fluoroquinolone-type antibiotics were identified to be compounds highly active against Trypanosoma brucei brucei Since the lead compound GHQ168 was challenged by poor water solubility in previous trials, the aim of this study was to introduce structural variations to GHQ168 as well as to formulate GHQ168 with the ultimate goal to increase its aqueous solubility while maintaining its in vitro antitrypanosomal activity. The pharmacokinetic parameters of spray-dried GHQ168 and the newly synthesized compounds GHQ242 and GHQ243 in mice were characterized by elimination half-lives ranging from 1.5 to 3.5 h after intraperitoneal administration (4 mice/compound), moderate to strong human serum albumin binding for GHQ168 (80%) and GHQ243 (45%), and very high human serum albumin binding (>99%) for GHQ242. For the lead compound, GHQ168, the apparent clearance was 112 ml/h and the apparent volume of distribution was 14 liters/kg of body weight (BW). Mice infected with T. b. rhodesiense (STIB900) were treated in a stringent study scheme (2 daily applications between days 3 and 6 postinfection). Exposure to spray-dried GHQ168 in contrast to the control treatment resulted in mean survival durations of 17 versus 9 days, respectively, a difference that was statistically significant. Results that were statistically insignificantly different were obtained between the control and the GHQ242 and GHQ243 treatments. Therefore, GHQ168 was further profiled in an early-treatment scheme (2 daily applications at days 1 to 4 postinfection), and the results were compared with those obtained with a control treatment. The result was statistically significant mean survival times exceeding 32 days (end of the observation period) versus 7 days for the GHQ168 and control treatments

Pathogenicity of bloodstream and cerebrospinal fluid forms of ...

African Journals Online (AJOL)

kemrilib

brain barrier and invade the central nervous system (CNS). However, it is not clear whether bloodstream forms (BSF) of T.b.rhodesiense differ in biological characteristics from ... carried out to compare the pathogenicity of CSF and BSF of T.b. rhodesiense parasites in ..... Swiss white of the same sex, the difference in survival ...

Molecular characterization of bovine trypanosomes from the Kachia ...

African Journals Online (AJOL)

The PCR assay allowed detection and characterization of three Trypanosoma livestock species namely T. vivax, 13 of 33 was positive; T. congolense forest, 1 of 2 and 1 T. b. brucei. The sizes of base ... For diagnostic purposes, improvement in primer designs for enhancing T. vivax detection in field samples is suggested.

Genetic and structural study of DNA-directed RNA polymerase II of Trypanosoma brucei, towards the designing of novel antiparasitic agents

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Louis Papageorgiou

2017-03-01

Full Text Available Trypanosoma brucei brucei (TBB belongs to the unicellular parasitic protozoa organisms, specifically to the Trypanosoma genus of the Trypanosomatidae class. A variety of different vertebrate species can be infected by TBB, including humans and animals. Under particular conditions, the TBB can be hosted by wild and domestic animals; therefore, an important reservoir of infection always remains available to transmit through tsetse flies. Although the TBB parasite is one of the leading causes of death in the most underdeveloped countries, to date there is neither vaccination available nor any drug against TBB infection. The subunit RPB1 of the TBB DNA-directed RNA polymerase II (DdRpII constitutes an ideal target for the design of novel inhibitors, since it is instrumental role is vital for the parasite’s survival, proliferation, and transmission. A major goal of the described study is to provide insights for novel anti-TBB agents via a state-of-the-art drug discovery approach of the TBB DdRpII RPB1. In an attempt to understand the function and action mechanisms of this parasite enzyme related to its molecular structure, an in-depth evolutionary study has been conducted in parallel to the in silico molecular designing of the 3D enzyme model, based on state-of-the-art comparative modelling and molecular dynamics techniques. Based on the evolutionary studies results nine new invariant, first-time reported, highly conserved regions have been identified within the DdRpII family enzymes. Consequently, those patches have been examined both at the sequence and structural level and have been evaluated in regard to their pharmacological targeting appropriateness. Finally, the pharmacophore elucidation study enabled us to virtually in silico screen hundreds of compounds and evaluate their interaction capabilities with the enzyme. It was found that a series of chlorine-rich set of compounds were the optimal inhibitors for the TBB DdRpII RPB1 enzyme. All

Three Redox States of Trypanosoma brucei Alternative Oxidase Identified by Infrared Spectroscopy and Electrochemistry

Science.gov (United States)

Maréchal, Amandine; Kido, Yasutoshi; Kita, Kiyoshi; Moore, Anthony L.; Rich, Peter R.

2009-01-01

Electrochemistry coupled with Fourier transform infrared (IR) spectroscopy was used to investigate the redox properties of recombinant alternative ubiquinol oxidase from Trypanosoma brucei, the organism responsible for African sleeping sickness. Stepwise reduction of the fully oxidized resting state of recombinant alternative ubiquinol oxidase revealed two distinct IR redox difference spectra. The first of these, signal 1, titrates in the reductive direction as an n = 2 Nernstian component with an apparent midpoint potential of 80 mV at pH 7.0. However, reoxidation of signal 1 in the same potential range under anaerobic conditions did not occur and only began with potentials in excess of 500 mV. Reoxidation by introduction of oxygen was also unsuccessful. Signal 1 contained clear features that can be assigned to protonation of at least one carboxylate group, further perturbations of carboxylic and histidine residues, bound ubiquinone, and a negative band at 1554 cm−1 that might arise from a radical in the fully oxidized protein. A second distinct IR redox difference spectrum, signal 2, appeared more slowly once signal 1 had been reduced. This component could be reoxidized with potentials above 100 mV. In addition, when both signals 1 and 2 were reduced, introduction of oxygen caused rapid oxidation of both components. These data are interpreted in terms of the possible active site structure and mechanism of oxygen reduction to water. PMID:19767647

Wild chimpanzees are infected by Trypanosoma brucei

Czech Academy of Sciences Publication Activity Database

Jirků, Milan; Votýpka, Jan; Petrželková, Klára Judita; Jirků-Pomajbíková, K.; Kriegová, Eva; Vodička, R.; Lankester, F.; Leendertz, S. A. J.; Wittig, R. M.; Boesch, C.; Modrý, David; Ayala, F. J.; Leendertz, F. H.; Lukeš, Julius

2015-01-01

Roč. 4, č. 3 (2015), s. 277-282 ISSN 2213-2244 R&D Projects: GA MŠk(CZ) EE2.3.30.0032 EU Projects: European Commission(XE) 316304 Institutional support: RVO:60077344 Keywords : Trypanosomes * Chimpanzee * Non-human primates * Transmission * Diagnostics Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine

A New Alkamide with an Endoperoxide Structure from Acmella ciliata (Asteraceae) and Its in Vitro Antiplasmodial Activity.

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Silveira, Narjara; Saar, Julia; Santos, Alan Diego C; Barison, Andersson; Sandjo, Louis P; Kaiser, Marcel; Schmidt, Thomas J; Biavatti, Maique W

2016-06-11

From the aerial parts of Acmella ciliata (H.B.K.) Cassini (basionym Spilanthes ciliata Kunth; Asteraceae), three alkamides were isolated and identified by mass- and NMR spectroscopic methods as (2E,6E,8E)-N-isobutyl-2,6,8-decatrienamide (spilanthol, (1)), N-(2-phenethyl)-2E-en-6,8-nonadiynamide (2) and (2E,7Z)-6,9-endoperoxy-N-isobutyl-2,7-decadienamide (3). While 1 and 2 are known alkamides, compound 3 has not been described until now. It was found that the unusual cyclic peroxide 3 exists as a racemate of both enantiomers of each alkamide; the 6,9-cis- as well as the 6,9-trans-configured diastereomers, the former represents the major, the latter the minor constituent of the mixture. In vitro tests for activity against the human pathogenic parasites Trypanosoma brucei rhodesiense and Plasmodium falciparum revealed that 1 and 3 possess activity against the NF54 strain of the latter (IC50 values of 4.5 and 5.1 µM, respectively) while 2 was almost inactive. Compound 3 was also tested against multiresistant P. falciparum K1 and was found to be even more active against this parasite strain (IC50 = 2.1 µM) with considerable selectivity (IC50 against L6 rat skeletal myoblasts = 168 µM).

Genotypic status of the TbAT1/P2 adenosine transporter of Trypanosoma brucei gambiense isolates from Northwestern Uganda following melarsoprol withdrawal.

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Anne J N Kazibwe

Full Text Available BACKGROUND: The development of arsenical and diamidine resistance in Trypanosoma brucei is associated with loss of drug uptake by the P2 purine transporter as a result of alterations in the corresponding T. brucei adenosine transporter 1 gene (TbAT1. Previously, specific TbAT1 mutant type alleles linked to melarsoprol treatment failure were significantly more prevalent in T. b. gambiense from relapse patients at Omugo health centre in Arua district. Relapse rates of up to 30% prompted a shift from melarsoprol to eflornithine (alpha-difluoromethylornithine, DFMO as first-line treatment at this centre. The aim of this study was to determine the status of TbAT1 in recent isolates collected from T. b. gambiense sleeping sickness patients from Arua and Moyo districts in Northwestern Uganda after this shift in first-line drug choice. METHODOLOGY AND RESULTS: Blood and cerebrospinal fluids of consenting patients were collected for DNA preparation and subsequent amplification. All of the 105 isolates from Omugo that we successfully analysed by PCR-RFLP possessed the TbAT1 wild type allele. In addition, PCR/RFLP analysis was performed for 74 samples from Moyo, where melarsoprol is still the first line drug; 61 samples displayed the wild genotype while six were mutant and seven had a mixed pattern of both mutant and wild-type TbAT1. The melarsoprol treatment failure rate at Moyo over the same period was nine out of 101 stage II cases that were followed up at least once. Five of the relapse cases harboured mutant TbAT1, one had the wild type, while no amplification was achieved from the remaining three samples. CONCLUSIONS/SIGNIFICANCE: The apparent disappearance of mutant alleles at Omugo may correlate with melarsoprol withdrawal as first-line treatment. Our results suggest that melarsoprol could successfully be reintroduced following a time lag subsequent to its replacement. A field-applicable test to predict melarsoprol treatment outcome and identify

Molecular Evidence of a Trypanosoma brucei gambiense Sylvatic Cycle in the Human African Trypanosomiasis Foci of Equatorial Guinea

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Carlos eCordon-Obras

2015-07-01

Full Text Available Gambiense trypanosomiasis is considered an anthroponotic disease. Consequently, control programs are generally aimed at stopping transmission of Trypanosoma brucei gambiense (T. b. gambiense by detecting and treating human cases. However, the persistence of numerous foci despite efforts to eliminate this disease questions this strategy as unique tool to pursue the eradication. The role of animals as a reservoir of T. b. gambiense is still controversial, but could partly explain maintenance of the infection at hypo-endemic levels. In the present study, we evaluated the presence of T. b. gambiense in wild animals in Equatorial Guinea. The infection rate ranged from 0.8% in the insular focus of Luba to more than 12% in Mbini, a focus with a constant trickle of human cases. The parasite was detected in a wide range of animal species including four species never described previously as putative reservoirs. Our study comes to reinforce the hypothesis that animals may play a role in the persistence of T. b. gambiense transmission, being particularly relevant in low transmission settings. Under these conditions the integration of sustained vector control and medical interventions should be considered to achieve the elimination of Gambiense trypanosomiasis.

A global comparison of the human and T. brucei degradomes gives insights about possible parasite drug targets.

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Susan T Mashiyama

Full Text Available We performed a genome-level computational study of sequence and structure similarity, the latter using crystal structures and models, of the proteases of Homo sapiens and the human parasite Trypanosoma brucei. Using sequence and structure similarity networks to summarize the results, we constructed global views that show visually the relative abundance and variety of proteases in the degradome landscapes of these two species, and provide insights into evolutionary relationships between proteases. The results also indicate how broadly these sequence sets are covered by three-dimensional structures. These views facilitate cross-species comparisons and offer clues for drug design from knowledge about the sequences and structures of potential drug targets and their homologs. Two protease groups ("M32" and "C51" that are very different in sequence from human proteases are examined in structural detail, illustrating the application of this global approach in mining new pathogen genomes for potential drug targets. Based on our analyses, a human ACE2 inhibitor was selected for experimental testing on one of these parasite proteases, TbM32, and was shown to inhibit it. These sequence and structure data, along with interactive versions of the protein similarity networks generated in this study, are available at http://babbittlab.ucsf.edu/resources.html.

A global comparison of the human and T. brucei degradomes gives insights about possible parasite drug targets.

Science.gov (United States)

Mashiyama, Susan T; Koupparis, Kyriacos; Caffrey, Conor R; McKerrow, James H; Babbitt, Patricia C

2012-01-01

We performed a genome-level computational study of sequence and structure similarity, the latter using crystal structures and models, of the proteases of Homo sapiens and the human parasite Trypanosoma brucei. Using sequence and structure similarity networks to summarize the results, we constructed global views that show visually the relative abundance and variety of proteases in the degradome landscapes of these two species, and provide insights into evolutionary relationships between proteases. The results also indicate how broadly these sequence sets are covered by three-dimensional structures. These views facilitate cross-species comparisons and offer clues for drug design from knowledge about the sequences and structures of potential drug targets and their homologs. Two protease groups ("M32" and "C51") that are very different in sequence from human proteases are examined in structural detail, illustrating the application of this global approach in mining new pathogen genomes for potential drug targets. Based on our analyses, a human ACE2 inhibitor was selected for experimental testing on one of these parasite proteases, TbM32, and was shown to inhibit it. These sequence and structure data, along with interactive versions of the protein similarity networks generated in this study, are available at http://babbittlab.ucsf.edu/resources.html.

Processing of metacaspase 2 from Trypanosoma brucei (TbMCA2) broadens its substrate specificity.

Science.gov (United States)

Gilio, Joyce M; Marcondes, Marcelo F; Ferrari, Débora; Juliano, Maria A; Juliano, Luiz; Oliveira, Vitor; Machado, Maurício F M

2017-04-01

Metacaspases are members of the cysteine peptidase family and may be implicated in programmed cell death in plants and lower eukaryotes. These proteases exhibit calcium-dependent activity and specificity for arginine residues at P 1 . In contrast to caspases, they do not require processing or dimerization for activity. Indeed, unprocessed metacaspase-2 of Trypanosoma brucei (TbMCA2) is active; however, it has been shown that cleavages at Lys 55 and Lys 268 increase TbMCA2 hydrolytic activity on synthetic substrates. The processed TbMCA2 comprises 3 polypeptide chains that remain attached by non-covalent bonds. Replacement of Lys 55 and Lys 268 with Gly via site-directed mutagenesis results in non-processed but enzymatically active mutant, TbMCA2 K55/268G. To investigate the importance of this processing for the activity and specificity of TbMCA2, we performed activity assays comparing the non-processed mutant (TbMCA2 K55/268G) with the processed TbMCA2 form. Significant differences between TbMCA2 WT (processed form) and TbMCA2 K55/268G (non-processed form) were observed. Specifically, we verified that although non-processed TbMCA2 is active when assayed with small synthetic substrates, the TbMCA2 form does not exhibit hydrolytic activity on large substrates such as azocasein, while processed TbMCA2 is able to readily digest this protein. Such differences can be relevant for understanding the physiological regulation and function of TbMCA2. Copyright © 2017 Elsevier B.V. All rights reserved.

Comparative Antitrypanosomal Screening Of Methanolic Extracts

African Journals Online (AJOL)

activities with per cent drop in parasite population of. 43.76 and 29.46 ... Intraperitoneal treatment of T. brucei brucei-infected mice using these stem extracts at ... brucei brucei, Traditional medicine. ..... Journal of Biological Chemistry. 214:839-.

Identification and characterization of a stage specific membrane protein involved in flagellar attachment in Trypanosoma brucei.

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Katherine Woods

Full Text Available Flagellar attachment is a visibly striking morphological feature of African trypanosomes but little is known about the requirements for attachment at a molecular level. This study characterizes a previously undescribed membrane protein, FLA3, which plays an essential role in flagellar attachment in Trypanosoma brucei. FLA3 is heavily N-glycosylated, locates to the flagellar attachment zone and appears to be a bloodstream stage specific protein. Ablation of the FLA3 mRNA rapidly led to flagellar detachment and a concomitant failure of cytokinesis in the long slender bloodstream form but had no effect on the procyclic form. Flagellar detachment was obvious shortly after induction of the dsRNA and the newly synthesized flagellum was often completely detached after it emerged from the flagellar pocket. Within 12 h most cells possessed detached flagella alongside the existing attached flagellum. These results suggest that proteins involved in attachment are not shared between the new and old attachment zones. In other respects the detached flagella appear normal, they beat rapidly although directional motion was lost, and they possess an apparently normal axoneme and paraflagellar rod structure. The flagellar attachment zone appeared to be disrupted when FLA3 was depleted. Thus, while flagellar attachment is a constitutive feature of the life cycle of trypanosomes, attachment requires stage specific elements at the protein level.

Assessment of anti-protozoal activity of plants traditionally used in Ecuador in the treatment of leishmaniasis.

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Gachet, María Salomé; Lecaro, Javier Salazar; Kaiser, Marcel; Brun, Reto; Navarrete, Hugo; Muñoz, Ricardo A; Bauer, Rudolf; Schühly, Wolfgang

2010-03-02

For the assessment of the in vitro anti-protozoal potential of plants traditionally used in Ecuador in the treatment of leishmaniasis, a combined approach based on interviews with healers as well as a literature search was carried out. From three regions of Ecuador, 256 local healers called "Agents of Traditional Medicine" (ATMs) were interviewed about their knowledge of the use of plants to treat and heal the illness recognized by the ATMs as leishmaniasis. From literature sources, 14 plants were identified as being used in the treatment of leishmaniasis. Subsequently, plant material was collected from a representative selection of 39 species. A total of 140 extracts were screened in vitro against Leishmania donovani, Plasmodium falciparum, Trypanosoma brucei rhodesiense and Trypanosoma cruzi. Additionally, these extracts were evaluated for their anti-microbial activities using five gram-positive and -negative bacteria as well as Candida albicans. The survey resulted in 431 use-records for 145 plant-taxa used for the treatment of leishmaniasis. The 10 most frequently reported taxa accounted for 37.7% of all records. In the case of leishmaniasis, activity was observed for Elephantopus mollis, Minquartia guianensis, Bocconia integrifolia, Gouania lupuloides, Scoparia dulcis, an as-yet-unidentified species of Piper and Brugmansia. For the leaves of M. guianensis and the twigs and bark of G. lupuloides a good selectivity index (SI) was found. IC(50) values and the SI of active plant extracts are presented. Copyright (c) 2010 Elsevier Ireland Ltd. All rights reserved.

Cyclical appearance of African trypanosomes in the cerebrospinal fluid: new insights in how trypanosomes enter the CNS.

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Stefan Mogk

Full Text Available It is textbook knowledge that human infective forms of Trypanosoma brucei, the causative agent of sleeping sickness, enter the brain across the blood-brain barrier after an initial phase of weeks (rhodesiense or months (gambiense in blood. Based on our results using an animal model, both statements seem questionable. As we and others have shown, the first infection relevant crossing of the blood brain border occurs via the choroid plexus, i.e. via the blood-CSF barrier. In addition, counting trypanosomes in blood-free CSF obtained by an atlanto-occipital access revealed a cyclical infection in CSF that was directly correlated to the trypanosome density in blood infection. We also obtained conclusive evidence of organ infiltration, since parasites were detected in tissues outside the blood vessels in heart, spleen, liver, eye, testis, epididymis, and especially between the cell layers of the pia mater including the Virchow-Robin space. Interestingly, in all organs except pia mater, heart and testis, trypanosomes showed either a more or less degraded appearance of cell integrity by loss of the surface coat (VSG, loss of the microtubular cytoskeleton and loss of the intracellular content, or where taken up by phagocytes and degraded intracellularly within lysosomes. This is also true for trypanosomes placed intrathecally into the brain parenchyma using a stereotactic device. We propose a different model of brain infection that is in accordance with our observations and with well-established facts about the development of sleeping sickness.

Excreted/Secreted Proteins from Trypanosome Procyclic Strains

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Celestine Michelle Atyame Nten

2010-01-01

Full Text Available Trypanosoma secretome was shown to be involved in parasite virulence and is suspected of interfering in parasite life-cycle steps such as establishment in the Glossina midgut, metacyclogenesis. Therefore, we attempted to identify the proteins secreted by procyclic strains of T. brucei gambiense and T. brucei brucei, responsible for human and animal trypanosomiasis, respectively. Using mass spectrometry, 427 and 483 nonredundant proteins were characterized in T. brucei brucei and T. brucei gambiense secretomes, respectively; 35% and 42% of the corresponding secretome proteins were specifically secreted by T. brucei brucei and T. brucei gambiense, respectively, while 279 proteins were common to both subspecies. The proteins were assigned to 12 functional classes. Special attention was paid to the most abundant proteases (14 families because of their potential implication in the infection process and nutrient supply. The presence of proteins usually secreted via an exosome pathway suggests that this type of process is involved in trypanosome ESP secretion. The overall results provide leads for further research to develop novel tools for blocking trypanosome transmission.

Probing the metabolic network in bloodstream-form Trypanosoma brucei using untargeted metabolomics with stable isotope labelled glucose.

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Darren J Creek

2015-03-01

Full Text Available Metabolomics coupled with heavy-atom isotope-labelled glucose has been used to probe the metabolic pathways active in cultured bloodstream form trypomastigotes of Trypanosoma brucei, a parasite responsible for human African trypanosomiasis. Glucose enters many branches of metabolism beyond glycolysis, which has been widely held to be the sole route of glucose metabolism. Whilst pyruvate is the major end-product of glucose catabolism, its transamination product, alanine, is also produced in significant quantities. The oxidative branch of the pentose phosphate pathway is operative, although the non-oxidative branch is not. Ribose 5-phosphate generated through this pathway distributes widely into nucleotide synthesis and other branches of metabolism. Acetate, derived from glucose, is found associated with a range of acetylated amino acids and, to a lesser extent, fatty acids; while labelled glycerol is found in many glycerophospholipids. Glucose also enters inositol and several sugar nucleotides that serve as precursors to macromolecule biosynthesis. Although a Krebs cycle is not operative, malate, fumarate and succinate, primarily labelled in three carbons, were present, indicating an origin from phosphoenolpyruvate via oxaloacetate. Interestingly, the enzyme responsible for conversion of phosphoenolpyruvate to oxaloacetate, phosphoenolpyruvate carboxykinase, was shown to be essential to the bloodstream form trypanosomes, as demonstrated by the lethal phenotype induced by RNAi-mediated downregulation of its expression. In addition, glucose derivatives enter pyrimidine biosynthesis via oxaloacetate as a precursor to aspartate and orotate.

Diagnostic reasoning strategies and diagnostic success.

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Coderre, S; Mandin, H; Harasym, P H; Fick, G H

2003-08-01

Cognitive psychology research supports the notion that experts use mental frameworks or "schemes", both to organize knowledge in memory and to solve clinical problems. The central purpose of this study was to determine the relationship between problem-solving strategies and the likelihood of diagnostic success. Think-aloud protocols were collected to determine the diagnostic reasoning used by experts and non-experts when attempting to diagnose clinical presentations in gastroenterology. Using logistic regression analysis, the study found that there is a relationship between diagnostic reasoning strategy and the likelihood of diagnostic success. Compared to hypothetico-deductive reasoning, the odds of diagnostic success were significantly greater when subjects used the diagnostic strategies of pattern recognition and scheme-inductive reasoning. Two other factors emerged as independent determinants of diagnostic success: expertise and clinical presentation. Not surprisingly, experts outperformed novices, while the content area of the clinical cases in each of the four clinical presentations demonstrated varying degrees of difficulty and thus diagnostic success. These findings have significant implications for medical educators. It supports the introduction of "schemes" as a means of enhancing memory organization and improving diagnostic success.

Clinical Presentation and Treatment Outcome of Sleeping Sickness in Sudanese Pre-School Children.

OpenAIRE

Eperon, G; Schmid, C; Loutan, L; Chappuis, F

2007-01-01

BACKGROUND: Existing data on human African trypanosomiasis (HAT) due to Trypanosoma brucei gambiense among children are limited. Here, we described the demographic, clinical, diagnostic, treatment and outcome characteristics of HAT in pre-school children from Kajo-Keji County, South Sudan in comparison with older patients. METHODS: We did a retrospective analysis of HAT patients treated at the Kiri Sleeping Sickness Treatment Centre (SSTC), Kajo-Keji County, from June 2000 to December 2002. R...

3D Architecture of the Trypanosoma brucei Flagella Connector, a Mobile Transmembrane Junction.

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Johanna L Höög

2016-01-01

Full Text Available Cellular junctions are crucial for the formation of multicellular organisms, where they anchor cells to each other and/or supportive tissue and enable cell-to-cell communication. Some unicellular organisms, such as the parasitic protist Trypanosoma brucei, also have complex cellular junctions. The flagella connector (FC is a three-layered transmembrane junction that moves with the growing tip of a new flagellum and attaches it to the side of the old flagellum. The FC moves via an unknown molecular mechanism, independent of new flagellum growth. Here we describe the detailed 3D architecture of the FC suggesting explanations for how it functions and its mechanism of motility.We have used a combination of electron tomography and cryo-electron tomography to reveal the 3D architecture of the FC. Cryo-electron tomography revealed layers of repetitive filamentous electron densities between the two flagella in the interstitial zone. Though the FC does not change in length and width during the growth of the new flagellum, the interstitial zone thickness decreases as the FC matures. This investigation also shows interactions between the FC layers and the axonemes of the new and old flagellum, sufficiently strong to displace the axoneme in the old flagellum. We describe a novel filament, the flagella connector fibre, found between the FC and the axoneme in the old flagellum.The FC is similar to other cellular junctions in that filamentous proteins bridge the extracellular space and are anchored to underlying cytoskeletal structures; however, it is built between different portions of the same cell and is unique because of its intrinsic motility. The detailed description of its structure will be an important tool to use in attributing structure / function relationships as its molecular components are discovered in the future. The FC is involved in the inheritance of cell shape, which is important for the life cycle of this human parasite.

Single-subunit oligosaccharyltransferases of Trypanosoma brucei display different and predictable peptide acceptor specificities.

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Jinnelov, Anders; Ali, Liaqat; Tinti, Michele; Güther, Maria Lucia S; Ferguson, Michael A J

2017-12-08

Trypanosoma brucei causes African trypanosomiasis and contains three full-length oligosaccharyltransferase (OST) genes; two of which, Tb STT3A and Tb STT3B, are expressed in the bloodstream form of the parasite. These OSTs have different peptide acceptor and lipid-linked oligosaccharide donor specificities, and trypanosomes do not follow many of the canonical rules developed for other eukaryotic N -glycosylation pathways, raising questions as to the basic architecture and detailed function of trypanosome OSTs. Here, we show by blue-native gel electrophoresis and stable isotope labeling in cell culture proteomics that the Tb STT3A and Tb STT3B proteins associate with each other in large complexes that contain no other detectable protein subunits. We probed the peptide acceptor specificities of the OSTs in vivo using a transgenic glycoprotein reporter system and performed glycoproteomics on endogenous parasite glycoproteins using sequential endoglycosidase H and peptide: N -glycosidase-F digestions. This allowed us to assess the relative occupancies of numerous N -glycosylation sites by endoglycosidase H-resistant N -glycans originating from Man 5 GlcNAc 2 -PP-dolichol transferred by Tb STT3A, and endoglycosidase H-sensitive N -glycans originating from Man 9 GlcNAc 2 -PP-dolichol transferred by Tb STT3B. Using machine learning, we assessed the features that best define Tb STT3A and Tb STT3B substrates in vivo and built an algorithm to predict the types of N -glycan most likely to predominate at all the putative N -glycosylation sites in the parasite proteome. Finally, molecular modeling was used to suggest why Tb STT3A has a distinct preference for sequons containing and/or flanked by acidic amino acid residues. Together, these studies provide insights into how a highly divergent eukaryote has re-wired protein N -glycosylation to provide protein sequence-specific N -glycan modifications. Data are available via ProteomeXchange with identifiers PXD007236, PXD007267

Diagnostic accuracy of organ electrodermal diagnostics | Szopinski ...

African Journals Online (AJOL)

Objective. To estimate the diagnostic accuracy as well as the scope of utilisation of a new bio-electronic method of organ diagnostics. Design. Double-blind comparative study of the diagnostic results obtained by means of organ electrodermal diagnostics (OED) and clinical diagnoses, as a criterion standard. Setting.

Dynamics of gamete production and mating in the parasitic protist Trypanosoma brucei.

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Peacock, Lori; Bailey, Mick; Gibson, Wendy

2016-07-20

Sexual reproduction in Plasmodium falciparum and Trypanosoma brucei occurs in the insect vector and is important in generating hybrid strains with different combinations of parental characteristics. Production of hybrid parasite genotypes depends on the likelihood of co-infection of the vector with multiple strains. In mosquitoes, existing infection with Plasmodium facilitates the establishment of a second infection, although the asynchronicity of gamete production subsequently prevents mating. In the trypanosome/tsetse system, flies become increasingly refractory to infection as they age, so the likelihood of a fly acquiring a second infection also decreases. This effectively restricts opportunities for trypanosome mating to co-infections picked up by the fly on its first feed, unless an existing infection increases the chance of successful second infection as in the Plasmodium/mosquito system. Using green and red fluorescent trypanosomes, we compared the rates of trypanosome infection and hybrid production in flies co-infected on the first feed, co-infected on a subsequent feed 18 days after emergence, or fed sequentially with each trypanosome clone 18 days apart. Infection rates were highest in the midguts and salivary glands (SG) of flies that received both trypanosome clones in their first feed, and were halved when the infected feed was delayed to day 18. In flies fed the two trypanosome clones sequentially, the second clone often failed to establish a midgut infection and consequently was not present in the SG. Nevertheless, hybrids were recovered from all three groups of infected flies. Meiotic stages and gametes were produced continuously from day 11 to 42 after the infective feed, and in sequentially infected flies, the co-occurrence of gametes led to hybrid formation. We found that a second trypanosome strain can establish infection in the tsetse SG 18 days after the first infected feed, with co-mingling of gametes and production of trypanosome hybrids

Hsp70/J-protein machinery from Glossina morsitans morsitans, vector of African trypanosomiasis.

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Stephen J Bentley

Full Text Available Tsetse flies (Glossina spp. are the sole vectors of the protozoan parasites of the genus Trypanosoma, the causative agents of African Trypanosomiasis. Species of Glossina differ in vector competence and Glossina morsitans morsitans is associated with transmission of Trypanosoma brucei rhodesiense, which causes an acute and often fatal form of African Trypanosomiasis. Heat shock proteins are evolutionarily conserved proteins that play critical roles in proteostasis. The activity of heat shock protein 70 (Hsp70 is regulated by interactions with its J-protein (Hsp40 co-chaperones. Inhibition of these interactions are emerging as potential therapeutic targets. The assembly and annotation of the G. m. morsitans genome provided a platform to identify and characterize the Hsp70s and J-proteins, and carry out an evolutionary comparison to its well-studied eukaryotic counterparts, Drosophila melanogaster and Homo sapiens, as well as Stomoxys calcitrans, a comparator species. In our study, we identified 9 putative Hsp70 proteins and 37 putative J-proteins in G. m. morsitans. Phylogenetic analyses revealed three evolutionarily distinct groups of Hsp70s, with a closer relationship to orthologues from its blood-feeding dipteran relative Stomoxys calcitrans. G. m. morsitans also lacked the high number of heat inducible Hsp70s found in D. melanogaster. The potential localisations, functions, domain organisations and Hsp70/J-protein partnerships were also identified. A greater understanding of the heat shock 70 (Hsp70 and J-protein (Hsp40 families in G. m. morsitans could enhance our understanding of the cell biology of the tsetse fly.

Estimating and mapping the population at risk of sleeping sickness.

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Pere P Simarro

Full Text Available Human African trypanosomiasis (HAT, also known as sleeping sickness, persists as a public health problem in several sub-Saharan countries. Evidence-based, spatially explicit estimates of population at risk are needed to inform planning and implementation of field interventions, monitor disease trends, raise awareness and support advocacy. Comprehensive, geo-referenced epidemiological records from HAT-affected countries were combined with human population layers to map five categories of risk, ranging from "very high" to "very low," and to estimate the corresponding at-risk population.Approximately 70 million people distributed over a surface of 1.55 million km(2 are estimated to be at different levels of risk of contracting HAT. Trypanosoma brucei gambiense accounts for 82.2% of the population at risk, the remaining 17.8% being at risk of infection from T. b. rhodesiense. Twenty-one million people live in areas classified as moderate to very high risk, where more than 1 HAT case per 10,000 inhabitants per annum is reported.Updated estimates of the population at risk of sleeping sickness were made, based on quantitative information on the reported cases and the geographic distribution of human population. Due to substantial methodological differences, it is not possible to make direct comparisons with previous figures for at-risk population. By contrast, it will be possible to explore trends in the future. The presented maps of different HAT risk levels will help to develop site-specific strategies for control and surveillance, and to monitor progress achieved by ongoing efforts aimed at the elimination of sleeping sickness.

Trypanosoma brucei gambiense adaptation to different mammalian sera is associated with VSG expression site plasticity.

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Cordon-Obras, Carlos; Cano, Jorge; González-Pacanowska, Dolores; Benito, Agustin; Navarro, Miguel; Bart, Jean-Mathieu

2013-01-01

Trypanosoma brucei gambiense infection is widely considered an anthroponosis, although it has also been found in wild and domestic animals. Thus, fauna could act as reservoir, constraining the elimination of the parasite in hypo-endemic foci. To better understand the possible maintenance of T. b. gambiense in local fauna and investigate the molecular mechanisms underlying adaptation, we generated adapted cells lines (ACLs) by in vitro culture of the parasites in different mammalian sera. Using specific antibodies against the Variant Surface Glycoproteins (VSGs) we found that serum ACLs exhibited different VSG variants when maintained in pig, goat or human sera. Although newly detected VSGs were independent of the sera used, the consistent appearance of different VSGs suggested remodelling of the co-transcribed genes at the telomeric Expression Site (VSG-ES). Thus, Expression Site Associated Genes (ESAGs) sequences were analysed to investigate possible polymorphism selection. ESAGs 6 and 7 genotypes, encoding the transferrin receptor (TfR), expressed in different ACLs were characterised. In addition, we quantified the ESAG6/7 mRNA levels and analysed transferrin (Tf) uptake. Interestingly, the best growth occurred in pig and human serum ACLs, which consistently exhibited a predominant ESAG7 genotype and higher Tf uptake than those obtained in calf and goat sera. We also detected an apparent selection of specific ESAG3 genotypes in the pig and human serum ACLs, suggesting that other ESAGs could be involved in the host adaptation processes. Altogether, these results suggest a model whereby VSG-ES remodelling allows the parasite to express a specific set of ESAGs to provide selective advantages in different hosts. Finally, pig serum ACLs display phenotypic adaptation parameters closely related to human serum ACLs but distinct to parasites grown in calf and goat sera. These results suggest a better suitability of swine to maintain T. b. gambiense infection supporting

Diagnostics

DEFF Research Database (Denmark)

Donné, A.J.H.; Costley, A.E.; Barnsley, R.

2007-01-01

of the measurements—time and spatial resolutions, etc—will in some cases be more stringent. Many of the measurements will be used in the real time control of the plasma driving a requirement for very high reliability in the systems (diagnostics) that provide the measurements. The implementation of diagnostic systems...... on ITER is a substantial challenge. Because of the harsh environment (high levels of neutron and gamma fluxes, neutron heating, particle bombardment) diagnostic system selection and design has to cope with a range of phenomena not previously encountered in diagnostic design. Extensive design and R......&D is needed to prepare the systems. In some cases the environmental difficulties are so severe that new diagnostic techniques are required. The starting point in the development of diagnostics for ITER is to define the measurement requirements and develop their justification. It is necessary to include all...

Design and Synthesis of Brain Penetrant Trypanocidal N-Myristoyltransferase Inhibitors.

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Bayliss, Tracy; Robinson, David A; Smith, Victoria C; Brand, Stephen; McElroy, Stuart P; Torrie, Leah S; Mpamhanga, Chido; Norval, Suzanne; Stojanovski, Laste; Brenk, Ruth; Frearson, Julie A; Read, Kevin D; Gilbert, Ian H; Wyatt, Paul G

2017-12-14

N-Myristoyltransferase (NMT) represents a promising drug target within the parasitic protozoa Trypanosoma brucei (T. brucei), the causative agent for human African trypanosomiasis (HAT) or sleeping sickness. We have previously validated T. brucei NMT as a promising druggable target for the treatment of HAT in both stages 1 and 2 of the disease. We report on the use of the previously reported DDD85646 (1) as a starting point for the design of a class of potent, brain penetrant inhibitors of T. brucei NMT.

2012 HIV Diagnostics Conference: the molecular diagnostics perspective.

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Branson, Bernard M; Pandori, Mark

2013-04-01

2012 HIV Diagnostic Conference Atlanta, GA, USA, 12-14 December 2012. This report highlights the presentations and discussions from the 2012 National HIV Diagnostic Conference held in Atlanta (GA, USA), on 12-14 December 2012. Reflecting changes in the evolving field of HIV diagnostics, the conference provided a forum for evaluating developments in molecular diagnostics and their role in HIV diagnosis. In 2010, the HIV Diagnostics Conference concluded with the proposal of a new diagnostic algorithm which included nucleic acid testing to resolve discordant screening and supplemental antibody test results. The 2012 meeting, picking up where the 2010 meeting left off, focused on scientific presentations that assessed this new algorithm and the role played by RNA testing and new developments in molecular diagnostics, including detection of total and integrated HIV-1 DNA, detection and quantification of HIV-2 RNA, and rapid formats for detection of HIV-1 RNA.

The use of yellow fluorescent hybrids to indicate mating in Trypanosoma brucei

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Ferris Vanessa

2008-02-01

Full Text Available Abstract Background Trypanosoma brucei undergoes genetic exchange in its insect vector, the tsetse fly, by an unknown mechanism. The difficulties of working with this experimental system of genetic exchange have hampered investigation, particularly because the trypanosome life cycle stages involved cannot be cultured in vitro and therefore must be examined in the insect. Searching for small numbers of hybrid trypanosomes directly in the fly has become possible through the incorporation of fluorescent reporter genes, and we have previously carried out a successful cross using a reporter-repressor strategy. However, we could not be certain that all fluorescent trypanosomes observed in that cross were hybrids, due to mutations of the repressor leading to spontaneous fluorescence, and we have therefore developed an alternative strategy. Results To visualize the production of hybrids in the fly, parental trypanosome clones were transfected with a gene encoding Green Fluorescent Protein (GFP or Red Fluorescent Protein (RFP. Co-infection of flies with red and green fluorescent parental trypanosomes produced yellow fluorescent hybrids, which were easily visualized in the fly salivary glands. Yellow trypanosomes were not seen in midgut or proventricular samples and first appeared in the glands as epimastigotes as early as 13 days after fly infection. Cloned progeny originating from individual salivary glands had yellow, red, green or no fluorescence and were confirmed as hybrids by microsatellite, molecular karyotype and kinetoplast (mitochondrial DNA analyses. Hybrid clones showed biparental inheritance of both nuclear and kinetoplast genomes. While segregation and reassortment of the reporter genes and microsatellite alleles were consistent with Mendelian inheritance, flow cytometry measurement of DNA content revealed both diploid and polyploid trypanosomes among the hybrid progeny clones. Conclusion The strategy of using production of yellow hybrids

A proline racemase based PCR for identification of Trypanosoma vivax in cattle blood.

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Regassa Fikru

Full Text Available A study was conducted to develop a Trypanosoma vivax (T. vivax specific PCR based on the T. vivax proline racemase (TvPRAC gene. Forward and reverse primers were designed that bind at 764-783 bp and 983-1002 bp of the gene. To assess its specificity, TvPRAC PCR was conducted on DNA extracted from different haemotropic pathogens: T. vivax from Nigeria, Ethiopia and Venezuela, T. congolense Savannah type, T. brucei brucei, T. evansi, T. equiperdum, T. theileri, Theileria parva, Anaplasma marginale, Babesia bovis and Babesia bigemina and from bovine, goat, mouse, camel and human blood. The analytical sensitivity of the TvPRAC PCR was compared with that of the ITS-1 PCR and the 18S PCR-RFLP on a dilution series of T. vivax DNA in water. The diagnostic performance of the three PCRs was compared on 411 Ethiopian bovine blood specimens collected in a former study. TvPRAC PCR proved to be fully specific for T. vivax, irrespective of its geographical origin. Its analytical sensitivity was lower than that of ITS-1 PCR. On these bovine specimens, TvPRAC PCR detected 8.3% T. vivax infections while ITS-1 PCR and 18S PCR-RFLP detected respectively 22.6 and 6.1% T. vivax infections. The study demonstrates that a proline racemase based PCR could be used, preferably in combination with ITS-1 PCR, as a species-specific diagnostic test for T. vivax infections worldwide.

Crovirin, a snake venom cysteine-rich secretory protein (CRISP with promising activity against Trypanosomes and Leishmania.

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Camila M Adade

2014-10-01

Full Text Available The neglected human diseases caused by trypanosomatids are currently treated with toxic therapy with limited efficacy. In search for novel anti-trypanosomatid agents, we showed previously that the Crotalus viridis viridis (Cvv snake venom was active against infective forms of Trypanosoma cruzi. Here, we describe the purification of crovirin, a cysteine-rich secretory protein (CRISP from Cvv venom with promising activity against trypanosomes and Leishmania.Crude venom extract was loaded onto a reverse phase analytical (C8 column using a high performance liquid chromatographer. A linear gradient of water/acetonitrile with 0.1% trifluoroacetic acid was used. The peak containing the isolated protein (confirmed by SDS-PAGE and mass spectrometry was collected and its protein content was measured. T. cruzi trypomastigotes and amastigotes, L. amazonensis promastigotes and amastigotes and T. brucei rhodesiense procyclic and bloodstream trypomastigotes were challenged with crovirin, whose toxicity was tested against LLC-MK2 cells, peritoneal macrophages and isolated murine extensor digitorum longus muscle. We purified a single protein from Cvv venom corresponding, according to Nano-LC MS/MS sequencing, to a CRISP of 24,893.64 Da, henceforth referred to as crovirin. Human infective trypanosomatid forms, including intracellular amastigotes, were sensitive to crovirin, with low IC50 or LD50 values (1.10-2.38 µg/ml. A considerably higher concentration (20 µg/ml of crovirin was required to elicit only limited toxicity on mammalian cells.This is the first report of CRISP anti-protozoal activity, and suggests that other members of this family might have potential as drugs or drug leads for the development of novel agents against trypanosomatid-borne neglected diseases.

Isolation of Trypanosoma brucei gambiense from cured and relapsed sleeping sickness patients and adaptation to laboratory mice.

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Patient Pati Pyana

Full Text Available BACKGROUND: Sleeping sickness due to Trypanosoma brucei (T.b. gambiense is still a major public health problem in some central African countries. Historically, relapse rates around 5% have been observed for treatment with melarsoprol, widely used to treat second stage patients. Later, relapse rates of up to 50% have been recorded in some isolated foci in Angola, Sudan, Uganda and Democratic Republic of the Congo (DRC. Previous investigations are not conclusive on whether decreased sensitivity to melarsoprol is responsible for these high relapse rates. Therefore we aimed to establish a parasite collection isolated from cured as well as from relapsed patients for downstream comparative drug sensitivity profiling. A major constraint for this type of investigation is that T.b. gambiense is particularly difficult to isolate and adapt to classical laboratory rodents. METHODOLOGY/PRINCIPAL FINDINGS: From 360 patients treated in Dipumba hospital, Mbuji-Mayi, D.R. Congo, blood and cerebrospinal fluid (CSF was collected before treatment. From patients relapsing during the 24 months follow-up, the same specimens were collected. Specimens with confirmed parasite presence were frozen in liquid nitrogen in a mixture of Triladyl, egg yolk and phosphate buffered glucose solution. Isolation was achieved by inoculation of the cryopreserved specimens in Grammomys surdaster, Mastomys natalensis and SCID mice. Thus, 85 strains were isolated from blood and CSF of 55 patients. Isolation success was highest in Grammomys surdaster. Forty strains were adapted to mice. From 12 patients, matched strains were isolated before treatment and after relapse. All strains belong to T.b. gambiense type I. CONCLUSIONS AND SIGNIFICANCE: We established a unique collection of T.b. gambiense from cured and relapsed patients, isolated in the same disease focus and within a limited period. This collection is available for genotypic and phenotypic characterisation to investigate the

Functional and structural insights revealed by molecular dynamics simulations of an essential RNA editing ligase in Trypanosoma brucei.

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Rommie E Amaro

2007-11-01

Full Text Available RNA editing ligase 1 (TbREL1 is required for the survival of both the insect and bloodstream forms of Trypanosoma brucei, the parasite responsible for the devastating tropical disease African sleeping sickness. The type of RNA editing that TbREL1 is involved in is unique to the trypanosomes, and no close human homolog is known to exist. In addition, the high-resolution crystal structure revealed several unique features of the active site, making this enzyme a promising target for structure-based drug design. In this work, two 20 ns atomistic molecular dynamics (MD simulations are employed to investigate the dynamics of TbREL1, both with and without the ATP substrate present. The flexibility of the active site, dynamics of conserved residues and crystallized water molecules, and the interactions between TbREL1 and the ATP substrate are investigated and discussed in the context of TbREL1's function. Differences in local and global motion upon ATP binding suggest that two peripheral loops, unique to the trypanosomes, may be involved in interdomain signaling events. Notably, a significant structural rearrangement of the enzyme's active site occurs during the apo simulations, opening an additional cavity adjacent to the ATP binding site that could be exploited in the development of effective inhibitors directed against this protozoan parasite. Finally, ensemble averaged electrostatics calculations over the MD simulations reveal a novel putative RNA binding site, a discovery that has previously eluded scientists. Ultimately, we use the insights gained through the MD simulations to make several predictions and recommendations, which we anticipate will help direct future experimental studies and structure-based drug discovery efforts against this vital enzyme.

Transcriptome and proteome analyses and the role of atypical calpain protein and autophagy in the spliced leader silencing pathway in Trypanosoma brucei.

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Hope, Ronen; Egarmina, Katarina; Voloshin, Konstantin; Waldman Ben-Asher, Hiba; Carmi, Shai; Eliaz, Dror; Drori, Yaron; Michaeli, Shulamit

2016-10-01

Under persistent ER stress, Trypanosoma brucei parasites induce the spliced leader silencing (SLS) pathway. In SLS, transcription of the SL RNA gene, the SL donor to all mRNAs, is extinguished, arresting trans-splicing and leading to programmed cell death (PCD). In this study, we investigated the transcriptome following silencing of SEC63, a factor essential for protein translocation across the ER membrane, and whose silencing induces SLS. The proteome of SEC63-silenced cells was analyzed with an emphasis on SLS-specific alterations in protein expression, and modifications that do not directly result from perturbations in trans-splicing. One such protein identified is an atypical calpain SKCRP7.1/7.2. Co-silencing of SKCRP7.1/7.2 and SEC63 eliminated SLS induction due its role in translocating the PK3 kinase. This kinase initiates SLS by migrating to the nucleus and phosphorylating TRF4 leading to shut-off of SL RNA transcription. Thus, SKCRP7.1 is involved in SLS signaling and the accompanying PCD. The role of autophagy in SLS was also investigated; eliminating autophagy through VPS34 or ATG7 silencing demonstrated that autophagy is not essential for SLS induction, but is associated with PCD. Thus, this study identified factors that are used by the parasite to cope with ER stress and to induce SLS and PCD. © 2016 John Wiley & Sons Ltd.

Relating faults in diagnostic reasoning with diagnostic errors and patient harm.

NARCIS (Netherlands)

Zwaan, L.; Thijs, A.; Wagner, C.; Wal, G. van der; Timmermans, D.R.M.

2012-01-01

Purpose: The relationship between faults in diagnostic reasoning, diagnostic errors, and patient harm has hardly been studied. This study examined suboptimal cognitive acts (SCAs; i.e., faults in diagnostic reasoning), related them to the occurrence of diagnostic errors and patient harm, and studied

Serological survey of African animal trypanosomosis in Ghana: The role of the antigen ELISA as a diagnostic tool

International Nuclear Information System (INIS)

Doku, C.K.; Seidu, I.B.M.

1997-01-01

Preliminary results are presented of the analysis of 3000 serum samples collected from Zebu cattle in the Nabogu valley. Of the 3000 serum samples collected so far, 182 have been tested using the buffy coat technique (BCT) and the antigen ELISA test. A total of 56 samples have been found positive by both techniques. Using the parasitological technique (=BCT) 44 samples were diagnosed to be positive, while the Ag-ELISA detected 19 positive samples. The majority (75%) of cases detected positive by either technique was due to a single infection by Trypanosoma brucei. (author). 4 refs, 1 fig., 3 tabs

Serological survey of African animal trypanosomosis in Ghana: The role of the antigen ELISA as a diagnostic tool

Energy Technology Data Exchange (ETDEWEB)

Doku, C K; Seidu, I B.M. [Central Veterinary Lab., Pong-Tamale (Ghana). Tsetse and Trypanosmosis Unit

1997-02-01

Preliminary results are presented of the analysis of 3000 serum samples collected from Zebu cattle in the Nabogu valley. Of the 3000 serum samples collected so far, 182 have been tested using the buffy coat technique (BCT) and the antigen ELISA test. A total of 56 samples have been found positive by both techniques. Using the parasitological technique (=BCT) 44 samples were diagnosed to be positive, while the Ag-ELISA detected 19 positive samples. The majority (75%) of cases detected positive by either technique was due to a single infection by Trypanosoma brucei. (author). 4 refs, 1 fig., 3 tabs.

Trypanosoma Infection Favors Brucella Elimination via IL-12/IFNγ-Dependent Pathways

Directory of Open Access Journals (Sweden)

Arnaud Machelart

2017-07-01

Full Text Available This study develops an original co-infection model in mice using Brucella melitensis, the most frequent cause of human brucellosis, and Trypanosoma brucei, the agent of African trypanosomiasis. Although the immunosuppressive effects of T. brucei in natural hosts and mice models are well established, we observed that the injection of T. brucei in mice chronically infected with B. melitensis induces a drastic reduction in the number of B. melitensis in the spleen, the main reservoir of the infection. Similar results are obtained with Brucella abortus- and Brucella suis-infected mice and B. melitensis-infected mice co-infected with Trypanosoma cruzi, demonstrating that this phenomenon is not due to antigenic cross-reactivity. Comparison of co-infected wild-type and genetically deficient mice showed that Brucella elimination required functional IL-12p35/IFNγ signaling pathways and the presence of CD4+ T cells. However, the impact of wild type and an attenuated mutant of T. brucei on B. melitensis were similar, suggesting that a chronic intense inflammatory reaction is not required to eliminate B. melitensis. Finally, we also tested the impact of T. brucei infection on the course of Mycobacterium tuberculosis infection. Although T. brucei strongly increases the frequency of IFNγ+CD4+ T cells, it does not ameliorate the control of M. tuberculosis infection, suggesting that it is not controlled by the same effector mechanisms as Brucella. Thus, whereas T. brucei infections are commonly viewed as immunosuppressive and pathogenic, our data suggest that these parasites can specifically affect the immune control of Brucella infection, with benefits for the host.

Diagnostic nerve ultrasonography

International Nuclear Information System (INIS)

Baeumer, T.; Grimm, A.; Schelle, T.

2017-01-01

For the diagnostics of nerve lesions an imaging method is necessary to visualize peripheral nerves and their surrounding structures for an etiological classification. Clinical neurological and electrophysiological investigations provide functional information about nerve lesions. The information provided by a standard magnetic resonance imaging (MRI) examination is inadequate for peripheral nerve diagnostics; however, MRI neurography is suitable but on the other hand a resource and time-consuming method. Using ultrasonography for peripheral nerve diagnostics. With ultrasonography reliable diagnostics of entrapment neuropathies and traumatic nerve lesions are possible. The use of ultrasonography for neuropathies shows that a differentiation between different forms is possible. Nerve ultrasonography is an established diagnostic tool. In addition to the clinical examination and clinical electrophysiology, structural information can be obtained, which results in a clear improvement in the diagnostics. Ultrasonography has become an integral part of the diagnostic work-up of peripheral nerve lesions in neurophysiological departments. Nerve ultrasonography is recommended for the diagnostic work-up of peripheral nerve lesions in addition to clinical and electrophysiological investigations. It should be used in the clinical work-up of entrapment neuropathies, traumatic nerve lesions and spacy-occupying lesions of nerves. (orig.) [de

Tune-Based Halo Diagnostics

International Nuclear Information System (INIS)

Cameron, Peter

2003-01-01

Tune-based halo diagnostics can be divided into two categories -- diagnostics for halo prevention, and diagnostics for halo measurement. Diagnostics for halo prevention are standard fare in accumulators, synchrotrons, and storage rings, and again can be divided into two categories -- diagnostics to measure the tune distribution (primarily to avoid resonances), and diagnostics to identify instabilities (which will not be discussed here). These diagnostic systems include kicked (coherent) tune measurement, phase-locked loop (PLL) tune measurement, Schottky tune measurement, beam transfer function (BTF) measurements, and measurement of transverse quadrupole mode envelope oscillations. We refer briefly to tune diagnostics used at RHIC and intended for the SNS, and then present experimental results. Tune-based diagnostics for halo measurement (as opposed to prevention) are considerably more difficult. We present one brief example of tune-based halo measurement

Intellectual property considerations for molecular diagnostic development with emphasis on companion diagnostics.

Science.gov (United States)

Glorikian, Harry; Warburg, Richard Jeremy; Moore, Kelly; Malinowski, Jennifer

2018-02-01

The development of molecular diagnostics is a complex endeavor, with multiple regulatory pathways to consider and numerous approaches to development and commercialization. Companion diagnostics, devices which are "essential for the safe and effective use of a corresponding drug or diagnostic product" (see U.S. Food & Drug Administration, In Vitro Diagnostics - Companion Diagnostics, U.S. Dept. of Health & Human Services(2016), available at https://www.fda.gov/medicaldevices/productsandmedicalprocedures/invitrodiagnostics/ucm407297.htm ) and complementary diagnostics, which are more broadly associated with a class of drug, are becoming increasingly important as integral components of the implementation of precision medicine. Areas covered: The following article will highlight the intellectual property ('IP') considerations pertinent to molecular diagnostics development with special emphasis on companion diagnostics. Expert opinion/commentary Summary: For all molecular diagnostics, intellectual property (IP) concerns are of paramount concern, whether the device will be marketed only in the United States or abroad. Taking steps to protect IP at each stage of product development is critical to optimize profitability of a diagnostic product. Also the legal framework around IP protection of diagnostic technologies has been changing over the previous few years and can be expected to continue to change in the foreseeable near future, thus, a comprehensive IP strategy should take into account the fact that changes in the law can be expected.

Veterinary Molecular Diagnostics

NARCIS (Netherlands)

Roest, H.I.J.; Engelsma, M.Y.; Weesendorp, E.; Bossers, A.; Elbers, A.R.W.

2017-01-01

In veterinary molecular diagnostics, samples originating from animals are tested. Developments in the farm animals sector and in our societal attitude towards pet animals have resulted in an increased demand for fast and reliable diagnostic techniques. Molecular diagnostics perfectly matches this

Aqueous extract of Hibiscus sabdarrifa calyx alleviates anemia and ...

African Journals Online (AJOL)

Aqueous extract of Hibiscus sabdarrifa calyx alleviates anemia and organ damage in Trypanosoma brucei brucei infected rats. IA Umar, E Daikwo, NG Maryoms, A Gidado, LB Buratai, FS Saka, MA Ibrahim ...

Plasma Diagnostics

Energy Technology Data Exchange (ETDEWEB)

Zaveryaev, V [Kurchatov Institute, Moscow (Russian Federation); others, and

2012-09-15

The success in achieving peaceful fusion power depends on the ability to control a high temperature plasma, which is an object with unique properties, possibly the most complicated object created by humans. Over years of fusion research a new branch of science has been created, namely plasma diagnostics, which involves knowledge of almost all fields of physics, from electromagnetism to nuclear physics, and up-to-date progress in engineering and technology (materials, electronics, mathematical methods of data treatment). Historically, work on controlled fusion started with pulsed systems and accordingly the methods of plasma parameter measurement were first developed for short lived and dense plasmas. Magnetically confined hot plasmas require the creation of special experimental techniques for diagnostics. The diagnostic set is the most scientifically intensive part of a plasma device. During many years of research operation some scientific tasks have been solved while new ones arose. New tasks often require significant changes in the diagnostic system, which is thus a very flexible part of plasma machines. Diagnostic systems are designed to solve several tasks. As an example here are the diagnostic tasks for the International Thermonuclear Experimental Reactor - ITER: (1) Measurements for machine protection and basic control; (2) Measurements for advanced control; (3) Additional measurements for performance evaluation and physics. Every new plasma machine is a further step along the path to the main goal - controlled fusion - and nobody knows in advance what new phenomena will be met on the way. So in the planning of diagnostic construction we should keep in mind further system upgrading to meet possible new scientific and technical challenges. (author)

Structure determination of glycogen synthase kinase-3 from Leishmania major and comparative inhibitor structure-activity relationships with Trypanosoma brucei GSK-3

Energy Technology Data Exchange (ETDEWEB)

Ojo, Kayode K; Arakaki, Tracy L; Napuli, Alberto J; Inampudi, Krishna K; Keyloun, Katelyn R; Zhang, Li; Hol, Wim G.J.; Verlind, Christophe L.M.J.; Merritt, Ethan A; Van Voorhis, Wesley C [UWASH

2012-04-24

Glycogen synthase kinase-3 (GSK-3) is a drug target under intense investigation in pharmaceutical companies and constitutes an attractive piggyback target for eukaryotic pathogens. Two different GSKs are found in trypanosomatids, one about 150 residues shorter than the other. GSK-3 short (GeneDB: Tb927.10.13780) has previously been validated genetically as a drug target in Trypanosoma brucei by RNAi induced growth retardation; and chemically by correlation between enzyme and in vitro growth inhibition. Here, we report investigation of the equivalent GSK-3 short enzymes of L. major (LmjF18.0270) and L. infantum (LinJ18_V3.0270, identical in amino acid sequences to LdonGSK-3 short) and a crystal structure of LmajGSK-3 short at 2 Å resolution. The inhibitor structure-activity relationships (SARs) of L. major and L. infantum are virtually identical, suggesting that inhibitors could be useful for both cutaneous and visceral leishmaniasis. Leishmania spp. GSK-3 short has different inhibitor SARs than TbruGSK-3 short, which can be explained mostly by two variant residues in the ATP-binding pocket. Indeed, mutating these residues in the ATP-binding site of LmajGSK-3 short to the TbruGSK-3 short equivalents results in a mutant LmajGSK-3 short enzyme with SAR more similar to that of TbruGSK-3 short. The differences between human GSK-3β (HsGSK-3β) and LmajGSK-3 short SAR suggest that compounds which selectively inhibit LmajGSK-3 short may be found.

Genetic recombination between human and animal parasites creates novel strains of human pathogen.

Science.gov (United States)

Gibson, Wendy; Peacock, Lori; Ferris, Vanessa; Fischer, Katrin; Livingstone, Jennifer; Thomas, James; Bailey, Mick

2015-03-01

Genetic recombination between pathogens derived from humans and livestock has the potential to create novel pathogen strains, highlighted by the influenza pandemic H1N1/09, which was derived from a re-assortment of swine, avian and human influenza A viruses. Here we investigated whether genetic recombination between subspecies of the protozoan parasite, Trypanosoma brucei, from humans and animals can generate new strains of human pathogen, T. b. rhodesiense (Tbr) responsible for sleeping sickness (Human African Trypanosomiasis, HAT) in East Africa. The trait of human infectivity in Tbr is conferred by a single gene, SRA, which is potentially transferable to the animal pathogen Tbb by sexual reproduction. We tracked the inheritance of SRA in crosses of Tbr and Tbb set up by co-transmitting genetically-engineered fluorescent parental trypanosome lines through tsetse flies. SRA was readily transferred into new genetic backgrounds by sexual reproduction between Tbr and Tbb, thus creating new strains of the human pathogen, Tbr. There was no evidence of diminished growth or transmissibility of hybrid trypanosomes carrying SRA. Although expression of SRA is critical to survival of Tbr in the human host, we show that the gene exists as a single copy in a representative collection of Tbr strains. SRA was found on one homologue of chromosome IV in the majority of Tbr isolates examined, but some Ugandan Tbr had SRA on both homologues. The mobility of SRA by genetic recombination readily explains the observed genetic variability of Tbr in East Africa. We conclude that new strains of the human pathogen Tbr are being generated continuously by recombination with the much larger pool of animal-infective trypanosomes. Such novel recombinants present a risk for future outbreaks of HAT.

Pharmacology of DB844, an orally active aza analogue of pafuramidine, in a monkey model of second stage human African trypanosomiasis.

Directory of Open Access Journals (Sweden)

John K Thuita

Full Text Available Novel drugs to treat human African trypanosomiasis (HAT are still urgently needed despite the recent addition of nifurtimox-eflornithine combination therapy (NECT to WHO Model Lists of Essential Medicines against second stage HAT, where parasites have invaded the central nervous system (CNS. The pharmacology of a potential orally available lead compound, N-methoxy-6-{5-[4-(N-methoxyamidino phenyl]-furan-2-yl}-nicotinamidine (DB844, was evaluated in a vervet monkey model of second stage HAT, following promising results in mice. DB844 was administered orally to vervet monkeys, beginning 28 days post infection (DPI with Trypanosoma brucei rhodesiense KETRI 2537. DB844 was absorbed and converted to the active metabolite 6-[5-(4-phenylamidinophenyl-furanyl-2-yl]-nicotinamide (DB820, exhibiting plasma C(max values of 430 and 190 nM for DB844 and DB820, respectively, after the 14th dose at 6 mg/kg qd. A 100-fold reduction in blood trypanosome counts was observed within 24 h of the third dose and, at the end of treatment evaluation performed four days post the last drug dose, trypanosomes were not detected in the blood or cerebrospinal fluid of any monkey. However, some animals relapsed during the 300 days of post treatment monitoring, resulting in a cure rate of 3/8 (37.5% and 3/7 (42.9% for the 5 mg/kg×10 days and the 6 mg/kg×14 days dose regimens respectively. These DB844 efficacy data were an improvement compared with pentamidine and pafuramidine both of which were previously shown to be non-curative in this model of CNS stage HAT. These data show that synthesis of novel diamidines with improved activity against CNS-stage HAT was possible.

Genetic recombination between human and animal parasites creates novel strains of human pathogen.

Directory of Open Access Journals (Sweden)

Wendy Gibson

2015-03-01

Full Text Available Genetic recombination between pathogens derived from humans and livestock has the potential to create novel pathogen strains, highlighted by the influenza pandemic H1N1/09, which was derived from a re-assortment of swine, avian and human influenza A viruses. Here we investigated whether genetic recombination between subspecies of the protozoan parasite, Trypanosoma brucei, from humans and animals can generate new strains of human pathogen, T. b. rhodesiense (Tbr responsible for sleeping sickness (Human African Trypanosomiasis, HAT in East Africa. The trait of human infectivity in Tbr is conferred by a single gene, SRA, which is potentially transferable to the animal pathogen Tbb by sexual reproduction. We tracked the inheritance of SRA in crosses of Tbr and Tbb set up by co-transmitting genetically-engineered fluorescent parental trypanosome lines through tsetse flies. SRA was readily transferred into new genetic backgrounds by sexual reproduction between Tbr and Tbb, thus creating new strains of the human pathogen, Tbr. There was no evidence of diminished growth or transmissibility of hybrid trypanosomes carrying SRA. Although expression of SRA is critical to survival of Tbr in the human host, we show that the gene exists as a single copy in a representative collection of Tbr strains. SRA was found on one homologue of chromosome IV in the majority of Tbr isolates examined, but some Ugandan Tbr had SRA on both homologues. The mobility of SRA by genetic recombination readily explains the observed genetic variability of Tbr in East Africa. We conclude that new strains of the human pathogen Tbr are being generated continuously by recombination with the much larger pool of animal-infective trypanosomes. Such novel recombinants present a risk for future outbreaks of HAT.

Increased burden of cardiovascular disease in carriers of APOL1 genetic variants.

Science.gov (United States)

Ito, Kaoru; Bick, Alexander G; Flannick, Jason; Friedman, David J; Genovese, Giulio; Parfenov, Michael G; Depalma, Steven R; Gupta, Namrata; Gabriel, Stacey B; Taylor, Herman A; Fox, Ervin R; Newton-Cheh, Christopher; Kathiresan, Sekar; Hirschhorn, Joel N; Altshuler, David M; Pollak, Martin R; Wilson, James G; Seidman, J G; Seidman, Christine

2014-02-28

Two distinct alleles in the gene encoding apolipoprotein L1 (APOL1), a major component of high-density lipoprotein, confer protection against Trypanosoma brucei rhodesiense infection and also increase risk for chronic kidney disease. Approximately 14% of Americans with African ancestry carry 2 APOL1 risk alleles, accounting for the high chronic kidney disease burden in this population. We tested whether APOL1 risk alleles significantly increase risk for atherosclerotic cardiovascular disease (CVD) in African Americans. We sequenced APOL1 in 1959 randomly selected African American participants in the Jackson Heart Study (JHS) and evaluated associations between APOL1 genotypes and renal and cardiovascular phenotypes. Previously identified association between APOL1 genotypes and chronic kidney disease was confirmed (P=2.4×10(-6)). Among JHS participants with 2 APOL1 risk alleles, we observed increased risk for CVD (50/763 events among participants without versus 37/280 events among participants with 2 risk alleles; odds ratio, 2.17; P=9.4×10(-4)). We replicated this novel association of APOL1 genotype with CVD in Women's Health Initiative (WHI) participants (66/292 events among participants without versus 37/101 events among participants with 2 risk alleles; odds ratio, 1.98; P=8.37×10(-3); JHS and WHI combined, P=8.5×10(-5); odds ratio, 2.12). The increased risk for CVD conferred by APOL1 alleles was robust to correction for both traditional CVD risk factors and chronic kidney disease. APOL1 variants contribute to atherosclerotic CVD risk, indicating a genetic component to cardiovascular health disparities in individuals of African ancestry. The considerable population of African Americans with 2 APOL1 risk alleles may benefit from intensive interventions to reduce CVD.

25 original article hematological derangement patterns in nigerian

African Journals Online (AJOL)

boaz

backdrop of emerging new trypanosome strains, is not well known. ..... (1, 26) had been associated with events leading to anemia in .... Trypanosoma brucei brucei infected mice. International .... Procedures, Mosby , New York, 1995 pp 23-. 68.

Companion diagnostics

DEFF Research Database (Denmark)

Jørgensen, Jan Trøst; Hersom, Maria

2016-01-01

of disease mechanisms, things are slowly changing. Within the last few years, we have seen an increasing number of predictive biomarker assays being developed to guide the use of targeted cancer drugs. This type of assay is called companion diagnostics and is developed in parallel to the drug using the drug-diagnostic...... co-development model. The development of companion diagnostics is a relatively new discipline and in this review, different aspects will be discussed including clinical and regulatory issues. Furthermore, examples of drugs, such as the ALK and PD-1/PD-L1 inhibitors, that have been approved recently....... Despite having discussed personalized medicine for more than a decade, we still see that most drug prescriptions for severe chronic diseases are largely based on 'trial and error' and not on solid biomarker data. However, with the advance of molecular diagnostics and a subsequent increased understanding...

Beyond Diagnostic Accuracy: The Clinical Utility of Diagnostic Tests

NARCIS (Netherlands)

Bossuyt, Patrick M. M.; Reitsma, Johannes B.; Linnet, Kristian; Moons, Karel G. M.

2012-01-01

Like any other medical technology or intervention, diagnostic tests should be thoroughly evaluated before their introduction into daily practice. Increasingly, decision makers, physicians, and other users of diagnostic tests request more than simple measures of a test's analytical or technical

Transferrin coupled azanthraquinone enhances the killing effect on trypanosomes. The role of lysosomal mannosidase

Directory of Open Access Journals (Sweden)

Nok A.J.

2002-12-01

Full Text Available Partially purified azanthraquinone (AQ extract from Mitracarpus scaber was coupled to bovine transferrin (Tf using azidophenyl glyoxal (APG. The AQ-APG-Tf conjugate was found to possess an enhanced in vitro trypanocidal activity against Trypanosoma congolense and T. brucei brucei. At low concentrations of 0.39-90 mg/ml, the conjugate diminished the growth of T. congolense and T. b. brucei dose dependently at the logarithmic phase. Both parasites were more sensitive to AQ-APG-Tf than to the free (AQ extract. Growth inhibition on the parasites by the free extract was observed at 20-200 mg/ml. The total activity of the lysosomal enzyme a-mannosidase was reduced in the T. congolense cells treated with AQ-APG-Tf in a dose related pattern. However, the activity of the mannosidase in the T. b. brucei treated cells is less affected. The AQ-APG-Tf is more effective on a mannosidase than free AQ, eight and four fold for T. congolense and T. b. brucei respectively. The results are discussed as regards the potency of using transferrin as suitable drug carrier in the chemotherapy of Human sleeping sickness.

42 CFR 410.32 - Diagnostic x-ray tests, diagnostic laboratory tests, and other diagnostic tests: Conditions.

Science.gov (United States)

2010-10-01

... Procedural Terminology published by the American Medical Association. (3) Levels of supervision. Except where... & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES MEDICARE PROGRAM SUPPLEMENTARY MEDICAL INSURANCE (SMI) BENEFITS Medical and Other Health Services § 410.32 Diagnostic x-ray tests, diagnostic laboratory...

Browse Title Index

African Journals Online (AJOL)

Items 1 - 50 of 272 ... Vol 12, No 2 (2014), Cryptosporidium infection in cattle in Ogun state, ... Vol 7, No 1 (2008), An overview of mastitis in Sokoto red goat, Nigeria ... trypanosoma brucei brucei infection, treatment and re-infection, Abstract PDF.

42 CFR 415.180 - Teaching setting requirements for the interpretation of diagnostic radiology and other diagnostic...

Science.gov (United States)

2010-10-01

... interpretation of diagnostic radiology and other diagnostic tests. 415.180 Section 415.180 Public Health CENTERS... for the interpretation of diagnostic radiology and other diagnostic tests. (a) General rule. Physician fee schedule payment is made for the interpretation of diagnostic radiology and other diagnostic tests...

RNA-seq de novo Assembly Reveals Differential Gene Expression in Glossina palpalis gambiensis Infected with Trypanosoma brucei gambiense vs. Non-Infected and Self-Cured Flies.

Science.gov (United States)

Hamidou Soumana, Illiassou; Klopp, Christophe; Ravel, Sophie; Nabihoudine, Ibouniyamine; Tchicaya, Bernadette; Parrinello, Hugues; Abate, Luc; Rialle, Stéphanie; Geiger, Anne

2015-01-01

Trypanosoma brucei gambiense (Tbg), causing the sleeping sickness chronic form, completes its developmental cycle within the tsetse fly vector Glossina palpalis gambiensis (Gpg) before its transmission to humans. Within the framework of an anti-vector disease control strategy, a global gene expression profiling of trypanosome infected (susceptible), non-infected, and self-cured (refractory) tsetse flies was performed, on their midguts, to determine differential genes expression resulting from in vivo trypanosomes, tsetse flies (and their microbiome) interactions. An RNAseq de novo assembly was achieved. The assembled transcripts were mapped to reference sequences for functional annotation. Twenty-four percent of the 16,936 contigs could not be annotated, possibly representing untranslated mRNA regions, or Gpg- or Tbg-specific ORFs. The remaining contigs were classified into 65 functional groups. Only a few transposable elements were present in the Gpg midgut transcriptome, which may represent active transpositions and play regulatory roles. One thousand three hundred and seventy three genes differentially expressed (DEGs) between stimulated and non-stimulated flies were identified at day-3 post-feeding; 52 and 1025 between infected and self-cured flies at 10 and 20 days post-feeding, respectively. The possible roles of several DEGs regarding fly susceptibility and refractoriness are discussed. The results provide new means to decipher fly infection mechanisms, crucial to develop anti-vector control strategies.

Ethyl Pyruvate Emerges as a Safe and Fast Acting Agent against Trypanosoma brucei by Targeting Pyruvate Kinase Activity.

Directory of Open Access Journals (Sweden)

Netsanet Worku

Full Text Available Human African Trypanosomiasis (HAT also called sleeping sickness is an infectious disease in humans caused by an extracellular protozoan parasite. The disease, if left untreated, results in 100% mortality. Currently available drugs are full of severe drawbacks and fail to escape the fast development of trypanosoma resistance. Due to similarities in cell metabolism between cancerous tumors and trypanosoma cells, some of the current registered drugs against HAT have also been tested in cancer chemotherapy. Here we demonstrate for the first time that the simple ester, ethyl pyruvate, comprises such properties.The current study covers the efficacy and corresponding target evaluation of ethyl pyruvate on T. brucei cell lines using a combination of biochemical techniques including cell proliferation assays, enzyme kinetics, phasecontrast microscopic video imaging and ex vivo toxicity tests. We have shown that ethyl pyruvate effectively kills trypanosomes most probably by net ATP depletion through inhibition of pyruvate kinase (Ki = 3.0±0.29 mM. The potential of ethyl pyruvate as a trypanocidal compound is also strengthened by its fast acting property, killing cells within three hours post exposure. This has been demonstrated using video imaging of live cells as well as concentration and time dependency experiments. Most importantly, ethyl pyruvate produces minimal side effects in human red cells and is known to easily cross the blood-brain-barrier. This makes it a promising candidate for effective treatment of the two clinical stages of sleeping sickness. Trypanosome drug-resistance tests indicate irreversible cell death and a low incidence of resistance development under experimental conditions.Our results present ethyl pyruvate as a safe and fast acting trypanocidal compound and show that it inhibits the enzyme pyruvate kinase. Competitive inhibition of this enzyme was found to cause ATP depletion and cell death. Due to its ability to easily cross

Applying Diagnostics to Enhance Cable System Reliability (Cable Diagnostic Focused Initiative, Phase II)

Energy Technology Data Exchange (ETDEWEB)

Hartlein, Rick [Georgia Tech Research Corporation (GTRC), Atlanta, GA (United States). National Electric Energy Testing, Research and Applications Center (NEETRAC); Hampton, Nigel [Georgia Tech Research Corporation (GTRC), Atlanta, GA (United States). National Electric Energy Testing, Research and Applications Center (NEETRAC); Perkel, Josh [Georgia Tech Research Corporation (GTRC), Atlanta, GA (United States). National Electric Energy Testing, Research and Applications Center (NEETRAC); Hernandez, JC [Univ. de Los Andes, Merida (Venezuela); Elledge, Stacy [Georgia Tech Research Corporation (GTRC), Atlanta, GA (United States). National Electric Energy Testing, Research and Applications Center (NEETRAC); del Valle, Yamille [Georgia Tech Research Corporation (GTRC), Atlanta, GA (United States). National Electric Energy Testing, Research and Applications Center (NEETRAC); Grimaldo, Jose [Georgia Inst. of Technology, Atlanta, GA (United States). School of Electrical and Computer Engineering; Deku, Kodzo [Georgia Inst. of Technology, Atlanta, GA (United States). George W. Woodruff School of Mechanical Engineering

2016-02-01

The Cable Diagnostic Focused Initiative (CDFI) played a significant and powerful role in clarifying the concerns and understanding the benefits of performing diagnostic tests on underground power cable systems. This project focused on the medium and high voltage cable systems used in utility transmission and distribution (T&D) systems. While many of the analysis techniques and interpretations are applicable to diagnostics and cable systems outside of T&D, areas such as generating stations (nuclear, coal, wind, etc.) and other industrial environments were not the focus. Many large utilities in North America now deploy diagnostics or have changed their diagnostic testing approach as a result of this project. Previous to the CDFI, different diagnostic technology providers individually promoted their approach as the “the best” or “the only” means of detecting cable system defects.

Hemoglobin is a co-factor of human trypanosome lytic factor

DEFF Research Database (Denmark)

Widener, Justin; Nielsen, Marianne Jensby; Shiflett, April

2007-01-01

Trypanosome lytic factor (TLF) is a high-density lipoprotein (HDL) subclass providing innate protection to humans against infection by the protozoan parasite Trypanosoma brucei brucei. Two primate-specific plasma proteins, haptoglobin-related protein (Hpr) and apolipoprotein L-1 (ApoL-1), have be...

Diagnostic dilemma

DEFF Research Database (Denmark)

Feldt-Rasmussen, Ulla; Dobrovolny, Robert; Nazarenko, Irina

2011-01-01

Fabry disease, an X-linked lysosomal storage disorder, results from the deficient activity of a-galactosidase A (a-Gal A). In affected males, the clinical diagnosis is confirmed by the markedly decreased a-Gal A activity. However, in female heterozygotes, the a-Gal A activity can range from low t...... on enzyme replacement therapy. Thus, gene dosage analyses can detect large deletions (>50bp) in suspect heterozygotes for X-linked and autosomal dominant diseases that are "sequencing cryptic," resolving molecular diagnostic dilemmas....... to normal due to random X-chromosomal inactivation, and diagnostic confirmation requires identification of the family's a-Gal A gene mutation. In a young female who had occasional acroparesthesias, corneal opacities, and 15 to 50% of the lower limit of normal leukocyte a-Gal A activity, a-Gal A sequencing...... in two expert laboratories did not identify a confirmatory mutation, presenting a diagnostic dilemma. A renal biopsy proved diagnostic and renewed efforts to detect an a-Gal A mutation. Subsequent gene dosage analyses identified a large a-Gal A deletion confirming her heterozygosity, and she was started...

Proteomic Analysis of Intact Flagella of Procyclic Trypanosoma brucei Cells Identifies Novel Flagellar Proteins with Unique Sub-localization and Dynamics*

Science.gov (United States)

Subota, Ines; Julkowska, Daria; Vincensini, Laetitia; Reeg, Nele; Buisson, Johanna; Blisnick, Thierry; Huet, Diego; Perrot, Sylvie; Santi-Rocca, Julien; Duchateau, Magalie; Hourdel, Véronique; Rousselle, Jean-Claude; Cayet, Nadège; Namane, Abdelkader; Chamot-Rooke, Julia; Bastin, Philippe

2014-01-01

Cilia and flagella are complex organelles made of hundreds of proteins of highly variable structures and functions. Here we report the purification of intact flagella from the procyclic stage of Trypanosoma brucei using mechanical shearing. Structural preservation was confirmed by transmission electron microscopy that showed that flagella still contained typical elements such as the membrane, the axoneme, the paraflagellar rod, and the intraflagellar transport particles. It also revealed that flagella severed below the basal body, and were not contaminated by other cytoskeletal structures such as the flagellar pocket collar or the adhesion zone filament. Mass spectrometry analysis identified a total of 751 proteins with high confidence, including 88% of known flagellar components. Comparison with the cell debris fraction revealed that more than half of the flagellum markers were enriched in flagella and this enrichment criterion was taken into account to identify 212 proteins not previously reported to be associated to flagella. Nine of these were experimentally validated including a 14-3-3 protein not yet reported to be associated to flagella and eight novel proteins termed FLAM (FLAgellar Member). Remarkably, they localized to five different subdomains of the flagellum. For example, FLAM6 is restricted to the proximal half of the axoneme, no matter its length. In contrast, FLAM8 is progressively accumulating at the distal tip of growing flagella and half of it still needs to be added after cell division. A combination of RNA interference and Fluorescence Recovery After Photobleaching approaches demonstrated very different dynamics from one protein to the other, but also according to the stage of construction and the age of the flagellum. Structural proteins are added to the distal tip of the elongating flagellum and exhibit slow turnover whereas membrane proteins such as the arginine kinase show rapid turnover without a detectible polarity. PMID:24741115

Proteomic analysis of intact flagella of procyclic Trypanosoma brucei cells identifies novel flagellar proteins with unique sub-localization and dynamics.

Science.gov (United States)

Subota, Ines; Julkowska, Daria; Vincensini, Laetitia; Reeg, Nele; Buisson, Johanna; Blisnick, Thierry; Huet, Diego; Perrot, Sylvie; Santi-Rocca, Julien; Duchateau, Magalie; Hourdel, Véronique; Rousselle, Jean-Claude; Cayet, Nadège; Namane, Abdelkader; Chamot-Rooke, Julia; Bastin, Philippe

2014-07-01

Cilia and flagella are complex organelles made of hundreds of proteins of highly variable structures and functions. Here we report the purification of intact flagella from the procyclic stage of Trypanosoma brucei using mechanical shearing. Structural preservation was confirmed by transmission electron microscopy that showed that flagella still contained typical elements such as the membrane, the axoneme, the paraflagellar rod, and the intraflagellar transport particles. It also revealed that flagella severed below the basal body, and were not contaminated by other cytoskeletal structures such as the flagellar pocket collar or the adhesion zone filament. Mass spectrometry analysis identified a total of 751 proteins with high confidence, including 88% of known flagellar components. Comparison with the cell debris fraction revealed that more than half of the flagellum markers were enriched in flagella and this enrichment criterion was taken into account to identify 212 proteins not previously reported to be associated to flagella. Nine of these were experimentally validated including a 14-3-3 protein not yet reported to be associated to flagella and eight novel proteins termed FLAM (FLAgellar Member). Remarkably, they localized to five different subdomains of the flagellum. For example, FLAM6 is restricted to the proximal half of the axoneme, no matter its length. In contrast, FLAM8 is progressively accumulating at the distal tip of growing flagella and half of it still needs to be added after cell division. A combination of RNA interference and Fluorescence Recovery After Photobleaching approaches demonstrated very different dynamics from one protein to the other, but also according to the stage of construction and the age of the flagellum. Structural proteins are added to the distal tip of the elongating flagellum and exhibit slow turnover whereas membrane proteins such as the arginine kinase show rapid turnover without a detectible polarity. © 2014 by The

Implementation of Rapid Molecular Infectious Disease Diagnostics: the Role of Diagnostic and Antimicrobial Stewardship.

Science.gov (United States)

Messacar, Kevin; Parker, Sarah K; Todd, James K; Dominguez, Samuel R

2017-03-01

New rapid molecular diagnostic technologies for infectious diseases enable expedited accurate microbiological diagnoses. However, diagnostic stewardship and antimicrobial stewardship are necessary to ensure that these technologies conserve, rather than consume, additional health care resources and optimally affect patient care. Diagnostic stewardship is needed to implement appropriate tests for the clinical setting and to direct testing toward appropriate patients. Antimicrobial stewardship is needed to ensure prompt appropriate clinical action to translate faster diagnostic test results in the laboratory into improved outcomes at the bedside. This minireview outlines the roles of diagnostic stewardship and antimicrobial stewardship in the implementation of rapid molecular infectious disease diagnostics. Copyright © 2017 American Society for Microbiology.

836 IJBCS-Article-Anthony Dawet

African Journals Online (AJOL)

KODJIO NORBERT

et al. (2001) reported that Cassia occidentalis,. Morinda morindoides and Phyllanthus niruri significantly reduced parasitaemia in. Plasmodium berghei infected mice. A study conducted by Bala et al. (2006) showed that Aloe vera and Coriandrum sativum were not generally effective in eliminating Trypanosoma brucei brucei.

Effects on haematological parameters and pathology of internal ...

African Journals Online (AJOL)

Effects on haematological parameters and pathology of internal organs of Trypanosoma brucei brucei infected albino rats. ... Group A served as the control (uninfected). ... The gross pathological effects on the internal organs showed significant enlargement of the spleen (splenomegaly) and slight enlargement of the liver ...

Diagnostic Algorithm Benchmarking

Science.gov (United States)

Poll, Scott

2011-01-01

A poster for the NASA Aviation Safety Program Annual Technical Meeting. It describes empirical benchmarking on diagnostic algorithms using data from the ADAPT Electrical Power System testbed and a diagnostic software framework.

Cognitive diagnostic assessment via Bayesian evaluation of informative diagnostic hypotheses.

NARCIS (Netherlands)

Hoijtink, Herbert; Béland, Sébastien; Vermeulen, Jorine A.

2014-01-01

There exist diverse approaches that can be used for cognitive diagnostic assessment, such as mastery testing, constrained latent class analysis, rule space methodology, diagnostic cognitive modeling, and person-fit analysis. Each of these approaches can be used within 1 of the 4 psychometric

Cognitive Diagnostic Assessment via Bayesian Evaluation of Informative Diagnostic Hypotheses

NARCIS (Netherlands)

Hoitink, Herbert; Beland, Sebastien; Vermeulen, Jorine

2014-01-01

There exist diverse approaches that can be used for cognitive diagnostic assessment, such as mastery testing, constrained latent class analysis, rule space methodology, diagnostic cognitive modeling, and person-fit analysis. Each of these approaches can be used within 1 of the 4 psychometric

Molecular Diagnostics

OpenAIRE

Choe, Hyonmin; Deirmengian, Carl A.; Hickok, Noreen J.; Morrison, Tiffany N.; Tuan, Rocky S.

2015-01-01

Orthopaedic infections are complex conditions that require immediate diagnosis and accurate identification of the causative organisms to facilitate appropriate management. Conventional methodologies for diagnosis of these infections sometimes lack accuracy or sufficient rapidity. Current molecular diagnostics are an emerging area of bench-to-bedside research in orthopaedic infections. Examples of promising molecular diagnostics include measurement of a specific biomarker in the synovial fluid...

In-vitro diagnostic devices introduction to current point-of-care diagnostic devices

CERN Document Server

Cheng, Chao-Min; Chen, Chien-Fu

2016-01-01

Addressing the origin, current status, and future development of point-of-care diagnostics, and serving to integrate knowledge and tools from Analytical Chemistry, Bioengineering, Biomaterials, and Nanotechnology, this book focusses on addressing the collective and combined needs of industry and academia (including medical schools) to effectively conduct interdisciplinary research. In addition to summarizing and detailing developed diagnostic devices, this book will attempt to point out the possible future trends of development for point-of-care diagnostics using both scientifically based research and practical engineering needs with the aim to help novices comprehensively understand the development of point-of-care diagnostics. This includes demonstrating several common but critical principles and mechanisms used in point-of-care diagnostics that address practical needs (e.g., disease or healthcare monitoring) using two well-developed examples so far: 1) blood glucose meters (via electrochemistry); and, 2) p...

International Conference on Plasma Diagnostics. Slides, papers and posters of Plasma Diagnostics 2010

International Nuclear Information System (INIS)

Hartfuss, H.J.; Bonhomme, G.; Grisolia, C.; Hirsch, M.; Klos, Z.; Mazouffre, S.; Musielok, J.; Ratynskaya, S.; Sadowski, M.; Van de Sanden, R.; Sentis, M.; Stroth, U.; Tereshin, V.; Tichy, M.; Unterberg, B.; Weisen, H.; Zoletnik, S.

2011-01-01

Plasma diagnostics 2010 is an International Conference on Diagnostic Methods involved in Research and Applications of Plasmas, originating on combining the 5. German-Polish Conference on Plasma Diagnostics for Fusion and Applications and the 7. French-Polish Seminar on Thermal Plasma in Space and Laboratory. The Scientific Committee of 'Plasma 2007' decided to concentrate the attention of future conferences more on the diagnostic development and diagnostic interpretation in the fields of high and low temperature plasmas and plasma applications. It is aimed at involving all European activities in the fields. The Scientific Program will cover the fields from low temperature laboratory to fusion plasmas of various configurations as well as dusty and astrophysical plasmas and industrial plasma applications

Proteomics of Trypanosoma evansi infection in rodents.

Science.gov (United States)

Roy, Nainita; Nageshan, Rishi Kumar; Pallavi, Rani; Chakravarthy, Harshini; Chandran, Syama; Kumar, Rajender; Gupta, Ashok Kumar; Singh, Raj Kumar; Yadav, Suresh Chandra; Tatu, Utpal

2010-03-22

Trypanosoma evansi infections, commonly called 'surra', cause significant economic losses to livestock industry. While this infection is mainly restricted to large animals such as camels, donkeys and equines, recent reports indicate their ability to infect humans. There are no World Animal Health Organization (WAHO) prescribed diagnostic tests or vaccines available against this disease and the available drugs show significant toxicity. There is an urgent need to develop improved methods of diagnosis and control measures for this disease. Unlike its related human parasites T. brucei and T. cruzi whose genomes have been fully sequenced T. evansi genome sequence remains unavailable and very little efforts are being made to develop improved methods of prevention, diagnosis and treatment. With a view to identify potential diagnostic markers and drug targets we have studied the clinical proteome of T. evansi infection using mass spectrometry (MS). Using shot-gun proteomic approach involving nano-lc Quadrupole Time Of Flight (QTOF) mass spectrometry we have identified over 160 proteins expressed by T. evansi in mice infected with camel isolate. Homology driven searches for protein identification from MS/MS data led to most of the matches arising from related Trypanosoma species. Proteins identified belonged to various functional categories including metabolic enzymes; DNA metabolism; transcription; translation as well as cell-cell communication and signal transduction. TCA cycle enzymes were strikingly missing, possibly suggesting their low abundances. The clinical proteome revealed the presence of known and potential drug targets such as oligopeptidases, kinases, cysteine proteases and more. Previous proteomic studies on Trypanosomal infections, including human parasites T. brucei and T. cruzi, have been carried out from lab grown cultures. For T. evansi infection this is indeed the first ever proteomic study reported thus far. In addition to providing a glimpse into the

Proteomics of Trypanosoma evansi infection in rodents.

Directory of Open Access Journals (Sweden)

Nainita Roy

2010-03-01

Full Text Available Trypanosoma evansi infections, commonly called 'surra', cause significant economic losses to livestock industry. While this infection is mainly restricted to large animals such as camels, donkeys and equines, recent reports indicate their ability to infect humans. There are no World Animal Health Organization (WAHO prescribed diagnostic tests or vaccines available against this disease and the available drugs show significant toxicity. There is an urgent need to develop improved methods of diagnosis and control measures for this disease. Unlike its related human parasites T. brucei and T. cruzi whose genomes have been fully sequenced T. evansi genome sequence remains unavailable and very little efforts are being made to develop improved methods of prevention, diagnosis and treatment. With a view to identify potential diagnostic markers and drug targets we have studied the clinical proteome of T. evansi infection using mass spectrometry (MS.Using shot-gun proteomic approach involving nano-lc Quadrupole Time Of Flight (QTOF mass spectrometry we have identified over 160 proteins expressed by T. evansi in mice infected with camel isolate. Homology driven searches for protein identification from MS/MS data led to most of the matches arising from related Trypanosoma species. Proteins identified belonged to various functional categories including metabolic enzymes; DNA metabolism; transcription; translation as well as cell-cell communication and signal transduction. TCA cycle enzymes were strikingly missing, possibly suggesting their low abundances. The clinical proteome revealed the presence of known and potential drug targets such as oligopeptidases, kinases, cysteine proteases and more.Previous proteomic studies on Trypanosomal infections, including human parasites T. brucei and T. cruzi, have been carried out from lab grown cultures. For T. evansi infection this is indeed the first ever proteomic study reported thus far. In addition to providing a

Regression models of reactor diagnostic signals

International Nuclear Information System (INIS)

Vavrin, J.

1989-01-01

The application is described of an autoregression model as the simplest regression model of diagnostic signals in experimental analysis of diagnostic systems, in in-service monitoring of normal and anomalous conditions and their diagnostics. The method of diagnostics is described using a regression type diagnostic data base and regression spectral diagnostics. The diagnostics is described of neutron noise signals from anomalous modes in the experimental fuel assembly of a reactor. (author)

Trypanocidal activity of the aqueous leave extract of Holarrhena ...

African Journals Online (AJOL)

This study evaluated the trypanocidal activity of aqueous extracts of leaves of young Holarrhena africana. The trypanocidal activity was evaluated by treatment of mice infected with Trypanosoma brucei brucei at the peak of infection. The aqueous extract was administered intraperitoneally for 5 consecutive days with varied ...

Anti-Trypanosomal Potential Of Momordica Balsamina Linn Fruit ...

African Journals Online (AJOL)

The search for new trypanocides has not been keenly pursued due to high cost of design and development with no promise of financial returns. Momordica balsamina fruit pulp extract was screened for antitrypanosomal activity in experimental Trypanosoma brucei brucei infection in rabbits. The extract was administered ...

Anti-trypanosomal effect of Malva sylvestris (Malvaceae) extract on a ...

African Journals Online (AJOL)

Methods: Sleeping sickness was induced by the intraperitoneal injection of ... count in the blood and CSF of mice with Trypanosoma brucei brucei-induced sleeping sickness compared ... The whole plant of Malva sylvestris was collected ... The animals were anesthetized by ... significantly (p < 0.01) improved the weight of.

G-Quadruplex Identification in the Genome of Protozoan Parasites Points to Naphthalene Diimide Ligands as New Antiparasitic Agents.

Science.gov (United States)

Belmonte-Reche, Efres; Martínez-García, Marta; Guédin, Aurore; Zuffo, Michela; Arévalo-Ruiz, Matilde; Doria, Filippo; Campos-Salinas, Jenny; Maynadier, Marjorie; López-Rubio, José Juan; Freccero, Mauro; Mergny, Jean-Louis; Pérez-Victoria, José María; Morales, Juan Carlos

2018-02-08

G-quadruplexes (G4) are DNA secondary structures that take part in the regulation of gene expression. Putative G4 forming sequences (PQS) have been reported in mammals, yeast, bacteria, and viruses. Here, we present PQS searches on the genomes of T. brucei, L. major, and P. falciparum. We found telomeric sequences and new PQS motifs. Biophysical experiments showed that EBR1, a 29 nucleotide long highly repeated PQS in T. brucei, forms a stable G4 structure. G4 ligands based on carbohydrate conjugated naphthalene diimides (carb-NDIs) that bind G4's including hTel could bind EBR1 with selectivity versus dsDNA. These ligands showed important antiparasitic activity. IC 50 values were in the nanomolar range against T. brucei with high selectivity against MRC-5 human cells. Confocal microscopy confirmed these ligands localize in the nucleus and kinetoplast of T. brucei suggesting they can reach their potential G4 targets. Cytotoxicity and zebrafish toxicity studies revealed sugar conjugation reduces intrinsic toxicity of NDIs.

Bovine trypanosomosis in north province of cameroon

International Nuclear Information System (INIS)

Ndamkou, C.N.; Nchare, A.

1997-01-01

The results of the examination of 2959 bovine blood samples collected from four divisions of North Province of Cameroon showed a prevalence of 1.72 for T. brucei, 0.98 for T. congolense and 4.03 for T. vivax using parasitological techniques, such as the buffy coat technique (BCT) and the microhaematrocrit centrifugation technique (MHCT). Prevalence rates in tsetse infested areas were higher than in tsetse free areas for T. brucei and T. congolense, but not for T. vivax. The Antigen ELISA was used to detect trypanosomal antigens in serum samples of a subset of the same animals. By using the Ag-ELISA many more animals were detected positive for T. brucei and T. vivax, but not for T. congolense, than when just the two parasitological techniques were used. As a matter of fact 90% of the T. brucei infections were detected by the Ag-ELISA and 10% by using either the BCT or the MHCT. (author).6 refs, 5 figs, 6 tabs

Bovine trypanosomosis in north province of cameroon

Energy Technology Data Exchange (ETDEWEB)

Ndamkou, C N; Nchare, A [Laboratoire National Veterinaire de Bokle (LANAVET), Garoua (Cameroon)

1997-02-01

The results of the examination of 2959 bovine blood samples collected from four divisions of North Province of Cameroon showed a prevalence of 1.72 for T. brucei, 0.98 for T. congolense and 4.03 for T. vivax using parasitological techniques, such as the buffy coat technique (BCT) and the microhaematrocrit centrifugation technique (MHCT). Prevalence rates in tsetse infested areas were higher than in tsetse free areas for T. brucei and T. congolense, but not for T. vivax. The Antigen ELISA was used to detect trypanosomal antigens in serum samples of a subset of the same animals. By using the Ag-ELISA many more animals were detected positive for T. brucei and T. vivax, but not for T. congolense, than when just the two parasitological techniques were used. As a matter of fact 90% of the T. brucei infections were detected by the Ag-ELISA and 10% by using either the BCT or the MHCT. (author).6 refs, 5 figs, 6 tabs.

Diagnostics on Z (invited)

International Nuclear Information System (INIS)

Nash, T. J.; Derzon, M. S.; Chandler, G. A.; Fehl, D. L.; Leeper, R. J.; Porter, J. L.; Spielman, R. B.; Ruiz, C.; Cooper, G.; McGurn, J.

2001-01-01

The 100 ns, 20 MA pinch-driver Z is surrounded by an extensive set of diagnostics. There are nine radial lines of sight set at 12 o above horizontal and each of these may be equipped with up to five diagnostic ports. Instruments routinely fielded viewing the pinch from the side with these ports include x-ray diode arrays, photoconducting detector arrays, bolometers, transmission grating spectrometers, time-resolved x-ray pinhole cameras, x-ray crystal spectrometers, calorimeters, silicon photodiodes, and neutron detectors. A diagnostic package fielded on axis for viewing internal pinch radiation consists of nine lines of sight. This package accommodates virtually the same diagnostics as the radial ports. Other diagnostics not fielded on the axial or radial ports include current B-dot monitors, filtered x-ray scintillators coupled by fiber optics to streak cameras, streaked visible spectroscopy, velocity interferometric system for any reflector, bremsstrahlung cameras, and active shock breakout measurement of hohlraum temperature. The data acquisition system is capable of recording up to 500 channels and the data from each shot is available on the Internet. A major new diagnostic presently under construction is the BEAMLET backlighter. We will briefly describe each of these diagnostics and present some of the highest-quality data from them

Plasma diagnostics discharge parameters and chemistry

CERN Document Server

Auciello, Orlando

1989-01-01

Plasma Diagnostics, Volume 1: Discharge Parameters and Chemistry covers seven chapters on the important diagnostic techniques for plasmas and details their use in particular applications. The book discusses optical diagnostic techniques for low pressure plasmas and plasma processing; plasma diagnostics for electrical discharge light sources; as well as Langmuir probes. The text also describes the mass spectroscopy of plasmas, microwave diagnostics, paramagnetic resonance diagnostics, and diagnostics in thermal plasma processing. Electrical engineers, nuclear engineers, microwave engineers, che

Diagnostic planning in JT-60 project

International Nuclear Information System (INIS)

Matoba, Tohru; Suzuki, Yasuo; Funahashi, Akimasa; Itagaki, Tokiyoshi

1977-08-01

The diagnostic plans of JT-60 were made along with design of the main machine. Basic requirements of the diagnostic program are (1) multiple measurement of respective plasma parameters, (2) efficient usage of the discharge, (3) capable data acquisition system, (4) high reliability of the diagnostic equipments, and (5) systematic development of new diagnostic techniques. Dimensions of the diagnostic ports were determined in detailed design of the vacuum vessel, anticipating the possible diagnostic methods. The proposed diagnostic systems and the plans are shown in table and figures respectively. Problems in the diagnostics are also described. (auth.)

Cable Diagnostic Focused Initiative

Energy Technology Data Exchange (ETDEWEB)

Hartlein, R.A.; Hampton, R.N.

2010-12-30

This report summarizes an extensive effort made to understand how to effectively use the various diagnostic technologies to establish the condition of medium voltage underground cable circuits. These circuits make up an extensive portion of the electric delivery infrastructure in the United States. Much of this infrastructure is old and experiencing unacceptable failure rates. By deploying efficient diagnostic testing programs, electric utilities can replace or repair circuits that are about to fail, providing an optimal approach to improving electric system reliability. This is an intrinsically complex topic. Underground cable systems are not homogeneous. Cable circuits often contain multiple branches with different cable designs and a range of insulation materials. In addition, each insulation material ages differently as a function of time, temperature and operating environment. To complicate matters further, there are a wide variety of diagnostic technologies available for assessing the condition of cable circuits with a diversity of claims about the effectiveness of each approach. As a result, the benefits of deploying cable diagnostic testing programs have been difficult to establish, leading many utilities to avoid the their use altogether. This project was designed to help address these issues. The information provided is the result of a collaborative effort between Georgia Tech NEETRAC staff, Georgia Tech academic faculty, electric utility industry participants, as well as cable system diagnostic testing service providers and test equipment providers. Report topics include: •How cable systems age and fail, •The various technologies available for detecting potential failure sites, •The advantages and disadvantages of different diagnostic technologies, •Different approaches for utilities to employ cable system diagnostics. The primary deliverables of this project are this report, a Cable Diagnostic Handbook (a subset of this report) and an online

Comparative antitrypanosomal screening of methanolic extracts of ...

African Journals Online (AJOL)

The in vitro and in vivo activities of methanolic extracts of defatted leaves and stems of Khaya senegalensis and Moringa oleifera on Trypanosoma brucei brucei were investigated and compared. The in vitro assessment involved incubating the parasite (in triplicate) in the presence of various extract concentrations in a ...

In vitro trypanocidal effect of methanolic extract of some Nigerian ...

African Journals Online (AJOL)

Methanol extracts from twenty three plants harvested from the Savannah vegetation belt of Nigeria were analyzed in vitro for trypanocidal activity against Trypanosoma brucei brucei and Trypanosoma congolense at concentrations of 4 mg/ml, 0.4 mg/ml and 0.04 mg/ml. Extracts of Khaya senegalensis, Piliostigma ...

ITER diagnostics ex-vessel engineering services

Energy Technology Data Exchange (ETDEWEB)

Arumugam, A.P., E-mail: arun.prakash@iter.org; Walker, C.I.; Andrew, P.; Barnsley, R.; Beltran, D.; Bertalot, L.; Dammann, A.; Direz, M.F.; Drevon, J.M.; Encheva, A.; Giacomin, T.; Hourtoule, J.; Kuehn, I.; Lanza, R.; Levesy, B.; Maquet, P.; Patel, K.M.; Patisson, L.; Pitcher, C.S.; Portales, M.; and others

2013-10-15

Highlights: • This paper describes about the ITER diagnostics ex-vessel engineering services. • It describes various diagnostics systems, its location and its environment. • Diagnostics interfaces with other services such as the buildings, HVAC, electrical services, cooling water, vacuum, liquid and gas distribution. • All the interfaces with these services are identified and defined. • Buildings services for diagnostics, such as penetrations, local shielding, embedment and temperature control are discussed. -- Abstract: Extensive diagnostics systems will be installed on the ITER machine to provide the measurements necessary to control, evaluate and optimize plasma performance in ITER and to further the understanding of plasma physics. These include measurements of temperature, density, impurity concentration, and particle and energy confinement times. ITER diagnostic systems extend from the center of the Tokamak to the various diagnostic areas, where they are controlled and acquired data is processed. This mainly includes the areas such as ports, port cells, gallery, diagnostics enclosures and cubicle areas. The diagnostics port plugs encloses the front end of the diagnostic systems and the diagnostics building houses the diagnostics equipment, instrumentation and control cubicles. There are several systems providing services to diagnostics. These mainly include ITER buildings, electrical power services, cooling water services, Heating Ventilation and Air Conditioning (HVAC), vacuum services, liquid and gas distribution services, cable engineering, de-tritiation systems, control cubicles, etc. Requirements of these service systems have to be defined, even though many of the diagnostics are at an early stage of development. It is a real challenge to define and to design diagnostics systems considering the constraints imposed by these service systems. This paper summarizes the provision of these services to the individual diagnostics and diagnostics areas

ITER diagnostics ex-vessel engineering services

International Nuclear Information System (INIS)

Arumugam, A.P.; Walker, C.I.; Andrew, P.; Barnsley, R.; Beltran, D.; Bertalot, L.; Dammann, A.; Direz, M.F.; Drevon, J.M.; Encheva, A.; Giacomin, T.; Hourtoule, J.; Kuehn, I.; Lanza, R.; Levesy, B.; Maquet, P.; Patel, K.M.; Patisson, L.; Pitcher, C.S.; Portales, M.

2013-01-01

Highlights: • This paper describes about the ITER diagnostics ex-vessel engineering services. • It describes various diagnostics systems, its location and its environment. • Diagnostics interfaces with other services such as the buildings, HVAC, electrical services, cooling water, vacuum, liquid and gas distribution. • All the interfaces with these services are identified and defined. • Buildings services for diagnostics, such as penetrations, local shielding, embedment and temperature control are discussed. -- Abstract: Extensive diagnostics systems will be installed on the ITER machine to provide the measurements necessary to control, evaluate and optimize plasma performance in ITER and to further the understanding of plasma physics. These include measurements of temperature, density, impurity concentration, and particle and energy confinement times. ITER diagnostic systems extend from the center of the Tokamak to the various diagnostic areas, where they are controlled and acquired data is processed. This mainly includes the areas such as ports, port cells, gallery, diagnostics enclosures and cubicle areas. The diagnostics port plugs encloses the front end of the diagnostic systems and the diagnostics building houses the diagnostics equipment, instrumentation and control cubicles. There are several systems providing services to diagnostics. These mainly include ITER buildings, electrical power services, cooling water services, Heating Ventilation and Air Conditioning (HVAC), vacuum services, liquid and gas distribution services, cable engineering, de-tritiation systems, control cubicles, etc. Requirements of these service systems have to be defined, even though many of the diagnostics are at an early stage of development. It is a real challenge to define and to design diagnostics systems considering the constraints imposed by these service systems. This paper summarizes the provision of these services to the individual diagnostics and diagnostics areas

Mobile diagnostics: next-generation technologies for in vitro diagnostics.

Science.gov (United States)

Shin, Joonchul; Chakravarty, Sudesna; Choi, Wooseok; Lee, Kyungyeon; Han, Dongsik; Hwang, Hyundoo; Choi, Jaekyu; Jung, Hyo-Il

2018-03-26

The emergence of a wide range of applications of smartphones along with advances in 'liquid biopsy' has significantly propelled medical research particularly in the field of in vitro diagnostics (IVD). Herein, we have presented a detailed analysis of IVD, its associated critical concerns and probable solutions. It also demonstrates the transition in terms of analytes from minimally invasive (blood) to non-invasive (urine, saliva and sweat) and depicts how the different features of a smartphone can be integrated for specific diagnostic purposes. This review basically highlights recent advances in the applications of smartphone-based biosensors in IVD taking into account the following factors: accuracy and portability; quantitative and qualitative analysis; and centralization and decentralization tests. Furthermore, the critical concerns and future direction of diagnostics based on smartphones are also discussed.

Interaction between the flagellar pocket collar and the hook complex via a novel microtubule-binding protein in Trypanosoma brucei.

Directory of Open Access Journals (Sweden)

Anna Albisetti

2017-11-01

Full Text Available Trypanosoma brucei belongs to a group of unicellular, flagellated parasites that are responsible for human African trypanosomiasis. An essential aspect of parasite pathogenicity is cytoskeleton remodelling, which occurs during the life cycle of the parasite and is accompanied by major changes in morphology and organelle positioning. The flagellum originates from the basal bodies and exits the cell body through the flagellar pocket (FP but remains attached to the cell body via the flagellum attachment zone (FAZ. The FP is an invagination of the pellicular membrane and is the sole site for endo- and exocytosis. The FAZ is a large complex of cytoskeletal proteins, plus an intracellular set of four specialised microtubules (MtQ that elongate from the basal bodies to the anterior end of the cell. At the distal end of the FP, an essential, intracellular, cytoskeletal structure called the flagellar pocket collar (FPC circumvents the flagellum. Overlapping the FPC is the hook complex (HC (a sub-structure of the previously named bilobe that is also essential and is thought to be involved in protein FP entry. BILBO1 is the only functionally characterised FPC protein and is necessary for FPC and FP biogenesis. Here, we used a combination of in vitro and in vivo approaches to identify and characterize a new BILBO1 partner protein-FPC4. We demonstrate that FPC4 localises to the FPC, the HC, and possibly to a proximal portion of the MtQ. We found that the C-terminal domain of FPC4 interacts with the BILBO1 N-terminal domain, and we identified the key amino acids required for this interaction. Interestingly, the FPC4 N-terminal domain was found to bind microtubules. Over-expression studies highlight the role of FPC4 in its association with the FPC, HC and FPC segregation. Our data suggest a tripartite association between the FPC, the HC and the MtQ.

Development of resazurin-based assay in 384-well format for high throughput whole cell screening of Trypanosoma brucei rhodesiense strain STIB 900 for the identification of potential anti-trypanosomal agents.

Science.gov (United States)

Lim, Kah Tee; Zahari, Zuriati; Amanah, Azimah; Zainuddin, Zafarina; Adenan, Mohd Ilham

2016-03-01

To accelerate the discovery of novel leads for the treatment of Human African Trypanosomiasis (HAT), it is necessary to have a simple, robust and cost-effective assay to identify positive hits by high throughput whole cell screening. Most of the fluorescence assay was made in black plate however in this study the HTS assay developed in 384-well format using clear plate and black plate, for comparison. The HTS assay developed is simple, sensitive, reliable and reproducible in both types of plates. Assay robustness and reproducibility were determined under the optimized conditions in 384-well plate was well tolerated in the HTS assay, including percentage of coefficient of variation (% CV) of 4.68% and 4.74% in clear and black 384-well plate, signal-to-background ratio (S/B) of 12.75 in clear 384-well plate and 12.07 in black 384-well plate, Z' factor of 0.79 and 0.82 in clear 384-well plate and black 384-well plate, respectively and final concentration of 0.30% dimethylsulfoxide (DMSO) in both types of plate. Drug sensitivity was found to be comparable to the reported anti-trypanosomal assay in 96-well format. The reproducibility and sensitivity of this assay make it compliant to automated liquid handler use in HTS applications. Copyright © 2016 Elsevier Inc. All rights reserved.

Diagnostic Development on NSTX

International Nuclear Information System (INIS)

A.L. Roquemore; D. Johnson; R. Kaita; et al

1999-01-01

Diagnostics are described which are currently installed or under active development for the newly commissioned NSTX device. The low aspect ratio (R/a less than or equal to 1.3) and low toroidal field (0.1-0.3T) used in this device dictate adaptations in many standard diagnostic techniques. Technical summaries of each diagnostic are given, and adaptations, where significant, are highlighted

Picosecond image-converter diagnostics

International Nuclear Information System (INIS)

Schelev, M.Ya.

1975-01-01

A brief review is presented of the improvements in picosecond image-converter diagnostics carried out since the previous Congress in 1972. The account is given under the following headings: picosecond image converter cameras for visible and x-ray radiation diagnostics; Nd:glass and ruby mode-locked laser measurements; x-ray plasma emission diagnostics; computer treatment of pictures produced by picosecond cameras. (U.K.)

LHD neutron diagnostics

International Nuclear Information System (INIS)

Isobe, M.; Ogawa, K.; Kobuchi, T.

2015-01-01

The Large Helical Device (LHD) project will step into a next stage, i.e. experiment by using deuterium gases after two years of preparation. A comprehensive set of neutron and γ-ray diagnostics is going to be installed on the LHD towards extension of energetic-particle (EP) physics research in heliotron plasmas. Conceptual design of fusion products diagnostics for the LHD was made in late 1990s. After conclusion of agreements for the LHD deuterium experiment with local government bodies, development of FPs diagnostics has begun lately. Because there are a lot of tasks to do, all Japan fusion neutron and γ-ray diagnostics team has been organized in the collaboration framework of National Institute for Fusion Science. FPs diagnostics system on the LHD will consist of 1) wide dynamic range neutron flux monitor (NFM), 2) neutron activation system (NAS), 3) vertical neutron camera (VNC). In addition to these, we are developing a directional scintillating fiber detector, an artificial diamond detector and a γ-ray scintillation detector for confinement study of MeV ions. A neutron energy spectrometer prototype is also being developed and tested in KSTAR. In this paper, roles of NFM, NAS and VNC and current status of implementation onto the LHD are briefly described. (author)

AcSDKP is down-regulated in anaemia induced by Trypanosoma ...

African Journals Online (AJOL)

We studied the responses of a tetrapeptide, AcSDKP, and IL-10, and their association with bone marrow nucleated cells in a Trypanosoma brucei brucei GVR35 experimental infection model. Methods Mouse infection was done intraperitoneally with 1 × 103 trypanosomes/mL. Mice were either infected or left uninfected (N ...

Bio-Research - Vol 3, No 1 (2005)

African Journals Online (AJOL)

Preliminary studies on the efficacy of aloe vera (Aloe barbadensis) extracts on experimental Trypanosoma brucei brucei infection of mice · EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. N Ivoke, 21-25. http://dx.doi.org/10.4314/br.v3i1.28565 ...

Plasma diagnostics for tokamaks and stellarators

International Nuclear Information System (INIS)

Stott, P.E.; Sanchez, J.

1994-01-01

A collection of papers on plasma diagnostics is presented. The papers show the state of the art developments in a series of techniques: magnetic diagnostics, Edge diagnostics, Langmuir probes, Spectroscopy, Microwave and FIR diagnostics as well as Thomson Sattering. Special interest was focused on those diagnostics oriented to fluctuations measurements in the plasma

Clinical diagnostic ultrasound

International Nuclear Information System (INIS)

Barnett, E.; Morley, P.

1986-01-01

This textbook on diagnostic ultrasound covers the main systems, with emphasis being placed on the clinical application of diagnostic ultrasound in everyday practice. It provides not only a textbook for postgraduates (particularly FRCR candidates), but also a reference work for practitioners of clinical ultrasound and clinicians generally

Plasma diagnostics on large tokamaks

International Nuclear Information System (INIS)

Orlinskij, D.V.; Magyar, G.

1988-01-01

The main tasks of the large tokamaks which are under construction (T-15 and Tore Supra) and of those which have already been built (TFTR, JET, JT-60 and DIII-D) together with their design features which are relevant to plasma diagnostics are briefly discussed. The structural features and principal characteristics of the diagnostic systems being developed or already being used on these devices are also examined. The different diagnostic methods are described according to the physical quantities to be measured: electric and magnetic diagnostics, measurements of electron density, electron temperature, the ion components of the plasma, radiation loss measurements, spectroscopy of impurities, edge diagnostics and study of plasma stability. The main parameters of the various diagnostic systems used on the six large tokamaks are summarized in tables. (author). 351 refs, 44 figs, 22 tabs

Plasma diagnostics for tokamaks and stellarators

Energy Technology Data Exchange (ETDEWEB)

Stott, P E; Sanchez, J

1994-07-01

A collection of papers on plasma diagnostics is presented. The papers show the state of the art developments in a series of techniques: Magnetic diagnostics, Edge diagnostics, Langmuir probes, Spectroscopy, Microwave and FIR diagnostics as well as Thomson Scattering. Special interest was focused on those diagnostics oriented to fluctuations measurements in the plasma. (Author) 451 refs.

Diagnostic development

International Nuclear Information System (INIS)

Barnett, C.F.; Brisson, D.A.; Greco, S.E.

1978-01-01

During the past year the far-infrared or submillimeter diagnostic research program resulted in three major developments: (1) an optically pumped 0.385-μm D 2 O-laser oscillator-amplifier system was operated at a power level of 1 MW with a line width of less than 50 MHz; (2) a conical Pyrex submillimeter laser beam dump with a retention efficiency greater than 10 4 was developed for the ion temperature Thompson scattering experiment; and (3) a new diagnostic technique was developed that makes use of the Faraday rotation of a modulated submillimeter laser beam to determine plasma current profile. Measurements of the asymmetric distortion of the H/sub α/ (6563 A) spectral line profile show that the effective toroidal drift velocity, dv/sub two vertical bars i/dT/sub i/, may be used as an indicator of plasma quality and as a complement to other ion temperature diagnostics

Optics/Optical Diagnostics Laboratory

Data.gov (United States)

Federal Laboratory Consortium — The Optics/Optical Diagnostics Laboratory supports graduate instruction in optics, optical and laser diagnostics and electro-optics. The optics laboratory provides...

Nordic working group for medical x-ray diagnostics: Diagnostic reference levels within xray diagnostics - experiences in the Nordic countries

International Nuclear Information System (INIS)

Leitz, W.; Groen, P.; Servomaa, A.; Einarsson, G.; Olerud, H.

2003-01-01

Medical x-ray diagnostics is one of the few applications of ionising radiation where people are irradiated on purpose. The strategy for radiation protection is also different compared to that in other areas that have the zero-alternative as its ultimate goal, meaning that no human beings at all are exposed in these practices. The focus in x-ray diagnostics concerning radiation protection is justification and optimisation. Optimisation implies that the examination is performed in such a way that the radiation dose is as small as possible without jeopardising the diagnostic security. X- ray diagnostics is a complex method where many technical parameters and methodology factors together are interacting in the determination of radiation dose and image quality. The optimisation process is not a simple and uncomplicated procedure, this difficulty is reflected in many international and national surveys showing a large spread of patient doses for one and the same type of examination. The concept diagnostic reference levels (DRL) has been introduced as a tool for reducing this wide distribution that is obviously indicating a lack of optimisation, and for cutting the highest radiation doses. In this presentation the concept for DRL and the experience gained in the Nordic countries with DRL are described. (orig.)

Companion diagnostics: a regulatory perspective from the last 5 years of molecular companion diagnostic approvals.

Science.gov (United States)

Roscoe, Donna M; Hu, Yun-Fu; Philip, Reena

2015-01-01

Companion diagnostics are essential for the safe and effective use of the corresponding therapeutic products. The US FDA has approved a number of companion diagnostics used to select cancer patients for treatment with contemporaneously approved novel therapeutics. The processes of co-development and co-approval of a therapeutic product and its companion diagnostic have been a learning experience that continues to evolve. Using several companion diagnostics as examples, this article describes the challenges associated with the scientific, clinical and regulatory hurdles faced by FDA and industry alike. Taken together, this discussion is intended to assist manufacturers toward a successful companion diagnostics development plan.

Diminazene aceturate-sodium oleate complex for the treatment of ...

African Journals Online (AJOL)

The aim of this study is to improve the efficacy of diminazene aceturate via complex formation with sodium oleate. The complex was subjected to various in vitro and in vivo tests to assess its properties, toxicity and efficacy against Trypanosoma brucei brucei infections in comparison to pure drug. Results revealed that the ...

Effect of Tetracycline on Late-stage African trypanosomiasis in Rats ...

African Journals Online (AJOL)

Effect of Tetracycline on Late-stage African trypanosomiasis in Rats. T.O. Johnson, J.T. Ekanem. Abstract. The effect of tetracycline on late stage African trypanosomiasis was examined in an in vivo experiment using rats infected with Trypanosoma brucei brucei. Infected rats were treated on the 5th day of infection with ...

Therapeutic Efficacy Of Cotecxin (R) alone and Its Combination with ...

African Journals Online (AJOL)

The therapeutic efficacy of Cotecxin(R) (Dihydroartemisinin) alone and its combination with diminazene aceturate (Berenil(R)) was studied in rats infected with Federe strain of Trypanosoma brucei brucei. Fifty healthy adult albino rats of both sexes weighing between 100-180g used were divided into five groups (A-E) of 10 ...

Plasma diagnostic reflectometry

International Nuclear Information System (INIS)

Cohen, B.I.; Afeyan, B.B.; Garrison, J.C.; Kaiser, T.B.; Luhmann, N.C. Jr.; Domier, C.W.; Chou, A.E.; Baang, S.

1996-01-01

Theoretical and experimental studies of plasma diagnostic reflectometry have been undertaken as a collaborative research project between the Lawrence Livermore National Laboratory (LLNL) and the University of California Department of Applied Science Plasma Diagnostics Group under the auspices of the Laboratory Directed Research and Development Program at LLNL. Theoretical analyses have explored the basic principles of reflectometry to understand its limitations, to address specific gaps in the understanding of reflectometry measurements in laboratory experiments, and to explore extensions of reflectometry such as ultra-short-pulse reflectometry. The theory has supported basic laboratory reflectometry experiments where reflectometry measurements can be corroborated by independent diagnostic measurements

Lectures in plasma diagnostics

International Nuclear Information System (INIS)

Hutchinson, I.H.

1990-06-01

This paper discusses the following topics on plasma diagnostics: Electric probes in flowing and magnetized plasmas; Electron cyclotron emission absorption; Magnetic diagnostics; Spectroscopy; and Thomson Scattering

Development of JT-60 diagnostics system

International Nuclear Information System (INIS)

Suzuki, Yasuo

1988-01-01

The various kinds of plasma diagnostics have been developed and utilized in the JT-60 experiments. The features of JT-60 diagnostics system and the historical proceeding of the development are described in this paper. Taking account of the design consideration, JT-60 diagnostics system is sorted out into eight groups, which include six diagnostics systems, the data processing system and diagnostics supporting system. The all devices in the JT-60 diagnostics system were instrumented on schedule in the end of the fiscal year of 1985 and have contributed to JT-60 experiments. (author)

Structure-Activity Relationship Study of Sesquiterpene Lactones and Their Semi-Synthetic Amino Derivatives as Potential Antitrypanosomal Products

Directory of Open Access Journals (Sweden)

Stefanie Zimmermann

2014-03-01

Full Text Available Sesquiterpene lactones (STLs are natural products that have potent antitrypanosomal activity in vitro and, in the case of cynaropicrin, also reduce parasitemia in the murine model of trypanosomiasis. To explore their structure-antitrypanosomal activity relationships, a set of 34 natural and semi-synthetic STLs and amino-STLs was tested in vitro against T. b. rhodesiense (which causes East African sleeping sickness and mammalian cancer cells (rat bone myoblast L6 cells. It was found that the α-methylene-γ-lactone moiety is necessary for both antitrypanosomal effects and cytotoxicity. Antitrypanosomal selectivity is facilitated by 2-(hydroxymethylacrylate or 3,4-dihydroxy-2-methylenebutylate side chains, and by the presence of cyclopentenone rings. Semi-synthetic STL amines with morpholino and dimethylamino groups showed improved in vitro activity over the native STLs. The dimethylamino derivative of cynaropicrin was prepared and tested orally in the T. b. rhodesiense acute mouse model, where it showed reduced toxicity over cynaropicrin, but also lost antitrypanosomal activity.

Molecular characterization and classification of Trypanosoma spp. Venezuelan isolates based on microsatellite markers and kinetoplast maxicircle genes.

Science.gov (United States)

Sánchez, E; Perrone, T; Recchimuzzi, G; Cardozo, I; Biteau, N; Aso, P M; Mijares, A; Baltz, T; Berthier, D; Balzano-Nogueira, L; Gonzatti, M I

2015-10-15

Livestock trypanosomoses, caused by three species of the Trypanozoon subgenus, Trypanosoma brucei brucei, T. evansi and T. equiperdum is widely distributed throughout the world and constitutes an important limitation for the production of animal protein. T. evansi and T. equiperdum are morphologically indistinguishable parasites that evolved from a common ancestor but acquired important biological differences, including host range, mode of transmission, distribution, clinical symptoms and pathogenicity. At a molecular level, T. evansi is characterized by the complete loss of the maxicircles of the kinetoplastic DNA, while T. equiperdum has retained maxicircle fragments similar to those present in T. brucei. T. evansi causes the disease known as Surra, Derrengadera or "mal de cadeiras", while T. equiperdum is the etiological agent of dourine or "mal du coit", characterized by venereal transmission and white patches in the genitalia. Nine Venezuelan Trypanosoma spp. isolates, from horse, donkey or capybara were genotyped and classified using microsatellite analyses and maxicircle genes. The variables from the microsatellite data and the Procyclin PE repeats matrices were combined using the Hill-Smith method and compared to a group of T. evansi, T. equiperdum and T. brucei reference strains from South America, Asia and Africa using Coinertia analysis. Four maxicircle genes (cytb, cox1, a6 and nd8) were amplified by PCRfrom TeAp-N/D1 and TeGu-N/D1, the two Venezuelan isolates that grouped with the T. equiperdum STIB841/OVI strain. These maxicircle sequences were analyzed by nucleotide BLAST and aligned toorthologous genes from the Trypanozoon subgenus by MUSCLE tools. Phylogenetic trees were constructed using Maximum Parsimony (MP) and Maximum Likelihood (ML) with the MEGA5.1® software. We characterized microsatellite markers and Procyclin PE repeats of nine Venezuelan Trypanosoma spp. isolates with various degrees of virulence in a mouse model, and compared them to a

Radiological diagnostics of skeletal tumors

International Nuclear Information System (INIS)

Uhl, M.; Herget, G.W.

2008-01-01

The book contains contributions concerning the following topics: 1. introduction and fundamentals: WHO classification of bone tumors, imaging diagnostics and their function; localization, typical clinical and radiological criteria, TNM classification and status classification, invasive tumor diagnostics; 2. specific tumor diagnostics: chondrogenic bone tumors, osseous tumors, connective tissue bony tumors, osteoclastoma, osteomyelogenic bone tumors, vascular bone tumors, neurogenic bone tumors, chordoma; adamantinoma of the long tubular bone; tumor-like lesions, bony metastases, bone granulomas, differential diagnostics: tumor-like lesions

Multidisciplinary molecular diagnostics: the 9th European meeting on molecular diagnostics.

Science.gov (United States)

Loonen, Anne J M; Schuurman, Rob; van den Brule, Adriaan J C

2016-01-01

This report presents a summary of the 9th European Meeting on Molecular Diagnostics held in Noordwijk, The Netherlands, 14-16 October 2015. This 3-day conference covered many relevant topics in the field of molecular diagnostics in humans, including infectious disease, oncology, outbreak management, population-based cancer screening, standardization and quality control, chronic diseases and pharmacogenetics. Beyond these different areas, shared values are new technologies and novel technical and clinical applications. Approximately 450 participants, the majority coming from European countries, attended the meeting. Besides high quality scientific presentations, more than 35 diagnostic companies presented their latest innovations, altogether in an informal and inspiring scientific ambience.

Cognitive aspect of diagnostic errors.

Science.gov (United States)

Phua, Dong Haur; Tan, Nigel C K

2013-01-01

Diagnostic errors can result in tangible harm to patients. Despite our advances in medicine, the mental processes required to make a diagnosis exhibits shortcomings, causing diagnostic errors. Cognitive factors are found to be an important cause of diagnostic errors. With new understanding from psychology and social sciences, clinical medicine is now beginning to appreciate that our clinical reasoning can take the form of analytical reasoning or heuristics. Different factors like cognitive biases and affective influences can also impel unwary clinicians to make diagnostic errors. Various strategies have been proposed to reduce the effect of cognitive biases and affective influences when clinicians make diagnoses; however evidence for the efficacy of these methods is still sparse. This paper aims to introduce the reader to the cognitive aspect of diagnostic errors, in the hope that clinicians can use this knowledge to improve diagnostic accuracy and patient outcomes.

Study for the design method of multi-agent diagnostic system to improve diagnostic performance for similar abnormality

International Nuclear Information System (INIS)

Minowa, Hirotsugu; Gofuku, Akio

2014-01-01

Accidents on industrial plants cause large loss on human, economic, social credibility. In recent, studies of diagnostic methods using techniques of machine learning such as support vector machine is expected to detect the occurrence of abnormality in a plant early and correctly. There were reported that these diagnostic machines has high accuracy to diagnose the operating state of industrial plant under mono abnormality occurrence. But the each diagnostic machine on the multi-agent diagnostic system may misdiagnose similar abnormalities as a same abnormality if abnormalities to diagnose increases. That causes that a single diagnostic machine may show higher diagnostic performance than one of multi-agent diagnostic system because decision-making considering with misdiagnosis is difficult. Therefore, we study the design method for multi-agent diagnostic system to diagnose similar abnormality correctly. This method aimed to realize automatic generation of diagnostic system where the generation process and location of diagnostic machines are optimized to diagnose correctly the similar abnormalities which are evaluated from the similarity of process signals by statistical method. This paper explains our design method and reports the result evaluated our method applied to the process data of the fast-breeder reactor Monju

Microbial Diagnostic Array Workstation (MDAW: a web server for diagnostic array data storage, sharing and analysis

Directory of Open Access Journals (Sweden)

Chang Yung-Fu

2008-09-01

Full Text Available Abstract Background Microarrays are becoming a very popular tool for microbial detection and diagnostics. Although these diagnostic arrays are much simpler when compared to the traditional transcriptome arrays, due to the high throughput nature of the arrays, the data analysis requirements still form a bottle neck for the widespread use of these diagnostic arrays. Hence we developed a new online data sharing and analysis environment customised for diagnostic arrays. Methods Microbial Diagnostic Array Workstation (MDAW is a database driven application designed in MS Access and front end designed in ASP.NET. Conclusion MDAW is a new resource that is customised for the data analysis requirements for microbial diagnostic arrays.

Author Details

African Journals Online (AJOL)

Ngobidi, KC. Vol 37, No 1 (2016) - Articles Hepatic response in Trypanosomia brucei brucei infected-rats treated with ethanol leaf extract of Tithonia diversifolia. Abstract. ISSN: 1117-4145. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More about AJOL · AJOL's ...

Evaluation of antitrypanosomal and anti inflammatory activities of selected Nigerian medicinal plants in mice.

Science.gov (United States)

Adelodun, Victoria O; Elusiyan, C A; Olorunmola, F O; Adewoyin, F B; Omisore, N O; Adepiti, A O; Agbedahunsi, J M; Adewunmi, C O

2013-01-01

The extracts of nine selected Nigerian medicinal plants were investigated on Trypanosoma brucei brucei infected mice. The anti-inflammatory properties of hexane fraction of the most promising U. chamae extract was assessed by acute oedema of the mice paw model while the modulatory effect of the extract on Delayed-Type Hypersensitivity (DTH) response on in vivo leucocytes mobilization was evaluated. 'Dose-probing acute toxicity tests' established an oral and intraperitoneal LD50 for T. ivorensis stem bark as >1600 5000 mg/kg. Extracts of Khaya senegalensis, Harungana madagascariensis, Terminalia ivorensis, Curcuma longa, Ocimum gratissimum and Alcornea cordifolia showed weak anti-trypanosomal effect and did not exhibit significant clearance in parasitemia at the test dose administered compared with the positive control (Diminal®). However, the leaf extract of U. chamae and its hexane fraction demonstrated a significant response (P < 0.01). The fraction at 1000 mg/kg inhibited oedema by 107%. Uvaria. chamae demonstrated both antitrypanosomal and anti-inflammatory properties by increasing the survival time of infected mice due to reduction in parasitemia caused by T. brucei brucei.

Anti-trypanosomal activity of cationic N-heterocyclic carbene gold(I) complexes.

Science.gov (United States)

Winter, Isabel; Lockhauserbäumer, Julia; Lallinger-Kube, Gertrud; Schobert, Rainer; Ersfeld, Klaus; Biersack, Bernhard

2017-06-01

Two gold(I) N-heterocyclic carbene complexes 1a and 1b were tested for their anti-trypanosomal activity against Trypanosoma brucei parasites. Both gold compounds exhibited excellent anti-trypanosomal activity (IC 50 =0.9-3.0nM). The effects of the gold complexes 1a and 1b on the T. b. brucei cytoskeleton were evaluated. Rapid detachment of the flagellum from the cell body occurred after treatment with the gold complexes. In addition, a quick and complete degeneration of the parasitic cytoskeleton was induced by the gold complexes, only the microtubules of the detached flagellum remained intact. Both gold compounds 1a and 1b feature selective anti-trypanosomal agents and were distinctly more active against T. b. brucei cells than against human HeLa cells. Thus, the gold complexes 1a and 1b feature promising drug candidates for the treatment of trypanosome infections such as sleeping sickness (human African Trypanosomiasis caused by Trypanosoma brucei parasites). Copyright © 2017 Elsevier B.V. All rights reserved.

Restriction fragment length polymorphism (RFLP) analysis of PCR products amplified from 18S ribosomal RNA gene of Trypanosoma congolense

International Nuclear Information System (INIS)

Osanyo, A.; Majiwa, P.W.

2006-01-01

Oligonucleotide primers were designed from the conserved nucleotide sequences of 18S ribosomal RNA (18S rRNA) gene of protozoans: Trypanosoma brucei, Leishmania donovani, Triponema aequale and Lagenidium gigantum. The primers were used in polymerace chain reaction (PCR) to generate PCR products of approximately 1 Kb using genomic DNA from T. brucei and the four genotypic groups of T. congolense as template. The five PCR products so produced were digested with several restriction enzymes and hybridized to a DNA probe made from T. brucei PCR product of the same 18S rRNA gene region. Most restriction enzyme digests revealed polymorphism with respect to the location of their recognition sites on the five PCR products. The restriction fragment length polymorphism (RFLP) pattern observed indicate that the 18S rRNA gene sequences of trypanosomes: T. brucei and the four genotypes of T.congolence group are heterogeneous. The results further demonstrate that the region that was amplified can be used in specific identification of trypanosomes species and subspecies.(author)

A TeGM6-4r antigen-based immunochromatographic test (ICT) for animal trypanosomosis.

Science.gov (United States)

Nguyen, Thu-Thuy; Ruttayaporn, Ngasaman; Goto, Yasuyuki; Kawazu, Shin-ichiro; Sakurai, Tatsuya; Inoue, Noboru

2015-11-01

Animal trypanosomosis is a disease that is distributed worldwide which results in huge economic losses due to reduced animal productivity. Endemic regions are often located in the countryside where laboratory diagnosis is costly or inaccessible. The establishment of simple, effective, and accurate field tests is therefore of great interest to the farming and veterinary sectors. Our study aimed to develop a simple, rapid, and sensitive immunochromatographic test (ICT) for animal trypanosomosis utilizing the recombinant tandem repeat antigen TeGM6-4r, which is conserved amongst salivarian trypanosome species. In the specificity analysis, TeGM6-4r/ICT detected all of Trypanosoma evansi-positive controls from experimentally infected water buffaloes. As expected, uninfected controls tested negative. All sera samples collected from Tanzanian and Ugandan cattle that were Trypanosoma congolense- and/or Trypanosoma vivax-positive by microscopic examination of the buffy coat were found to be positive by the newly developed TeGM6-4r/ICT, which was comparable to results from TeGM6-4r/ELISA (kappa coefficient [κ] = 0.78). TeGM6/ICT also showed substantial agreement with ELISA using Trypanosoma brucei brucei (κ = 0.64) and T. congolense (κ = 0.72) crude antigen, suggesting the high potential of TeGM6-4r/ICT as a field diagnostic test, both for research purposes and on-site diagnosis of animal trypanosomosis.

A new generation of optical diagnostics for bladder cancer: technology, diagnostic accuracy, and future applications

NARCIS (Netherlands)

Cauberg, Evelyne C. C.; de Bruin, Daniël M.; Faber, Dirk J.; van Leeuwen, Ton G.; de La Rosette, Jean J. M. C. H.; de Reijke, Theo M.

2009-01-01

CONTEXT: New developments in optical diagnostics have a potential for less invasive and improved detection of bladder cancer. OBJECTIVE: To provide an overview of the technology and diagnostic yield of recently developed optical diagnostics for bladder cancer and to outline their potential future

The architecture of diagnostic research

DEFF Research Database (Denmark)

Colli, Agostino; Fraquelli, Mirella; Casazza, Giovanni

2014-01-01

The diagnostic research process can be divided into five phases, designed to establish the clinical utility of a new diagnostic test - the index test. The aim of the present review is to illustrate the study designs that are appropriate for each diagnostic phase, using clinical examples regarding...

Towards diagnostics for a fusion reactor

International Nuclear Information System (INIS)

Costley, A. E.

2009-01-01

The requirements for measurements on modern tokamak fusion plasmas are outlined, and the techniques and systems used to make the measurements, usually referred to as 'diagnostics', are introduced. The basics of three particular diagnostics - magnetics, neutron systems and a laser based optical system - are outlined as examples of modern diagnostic systems, and the implementation of these diagnostics on a current tokamak (JET) are described. The next major step in magnetic confinement fusion is the construction and operation of the International Thermonuclear Experimental Reactor (ITER), which is a joint project of China, Europe, Japan, India, Korea, the Russian Federation, and the United States. Construction has begun in Cadarache, France. It is expected that ITER will operate at the 500 MW level. Because of the harsh environment in the vacuum vessel where many diagnostic components are located, the development of diagnostics for ITER is a major challenge - arguably the most difficult challenge ever undertaken in the field of diagnostics. The main elements in the diagnostic step are outlined using the three chosen techniques as examples. Finally, the step beyond ITER to a demonstration reactor, DEMO, that is expected to produce several GWs of fusion power is considered and the impact on diagnostics outlined. It is shown that the applicability and development steps needed for the individual diagnostics techniques will differ. The challenges for DEMO diagnostics are substantial and a dedicated effort should be made to find and develop new techniques, and especially techniques appropriate to the DEMO environment. It is argued that the limitations and difficulties in diagnostics should be a consideration in the optimization and designs of DEMO. (author)

A core MRB1 complex component is indispensable for RNA editing in insect and human infective stages of Trypanosoma brucei.

Directory of Open Access Journals (Sweden)

Michelle L Ammerman

Full Text Available Uridine insertion/deletion RNA editing is a unique and vital process in kinetoplastids, required for creation of translatable open reading frames in most mitochondrially-encoded RNAs. Emerging as a key player in this process is the mitochondrial RNA binding 1 (MRB1 complex. MRB1 comprises an RNA-independent core complex of at least six proteins, including the GAP1/2 guide RNA (gRNA binding proteins. The core interacts in an RNA-enhanced or -dependent manner with imprecisely defined TbRGG2 subcomplexes, Armadillo protein MRB10130, and additional factors that comprise the dynamic MRB1 complex. Towards understanding MRB1 complex function in RNA editing, we present here functional characterization of the pentein domain-containing MRB1 core protein, MRB11870. Inducible RNAi studies demonstrate that MRB11870 is essential for proliferation of both insect vector and human infective stage T. brucei. MRB11870 ablation causes a massive defect in RNA editing, affecting both pan-edited and minimally edited mRNAs, but does not substantially affect mitochondrial RNA stability or processing of precursor transcripts. The editing defect in MRB1-depleted cells occurs at the initiation stage of editing, as pre-edited mRNAs accumulate. However, the gRNAs that direct editing remain abundant in the knockdown cells. To examine the contribution of MRB11870 to MRB1 macromolecular interactions, we tagged core complexes and analyzed their composition and associated proteins in the presence and absence of MRB11870. These studies demonstrated that MRB11870 is essential for association of GAP1/2 with the core, as well as for interaction of the core with other proteins and subcomplexes. Together, these data support a model in which the MRB1 core mediates functional interaction of gRNAs with the editing machinery, having GAP1/2 as its gRNA binding constituents. MRB11870 is a critical component of the core, essential for its structure and function.

[Cognitive errors in diagnostic decision making].

Science.gov (United States)

Gäbler, Martin

2017-10-01

Approximately 10-15% of our diagnostic decisions are faulty and may lead to unfavorable and dangerous outcomes, which could be avoided. These diagnostic errors are mainly caused by cognitive biases in the diagnostic reasoning process.Our medical diagnostic decision-making is based on intuitive "System 1" and analytical "System 2" diagnostic decision-making and can be deviated by unconscious cognitive biases.These deviations can be positively influenced on a systemic and an individual level. For the individual, metacognition (internal withdrawal from the decision-making process) and debiasing strategies, such as verification, falsification and rule out worst-case scenarios, can lead to improved diagnostic decisions making.

TFTR diagnostic vacuum controller

International Nuclear Information System (INIS)

Olsen, D.; Persons, R.

1981-01-01

The TFTR diagnostic vacuum controller (DVC) provides in conjunction with the Central Instrumentation Control and Data Acquisition System (CICADA), control and monitoring for the pumps, valves and gauges associated with each individual diagnostic vacuum system. There will be approximately 50 systems on TFTR. Two standard versions of the controller (A and B) wil be provided in order to meet the requirements of two diagnostic manifold arrangements. All pump and valve sequencing, as well as protection features, will be implemented by the controller

Procedures in diagnostic radiology

International Nuclear Information System (INIS)

Doyle, T.; Hare, W.S.C.; Thomson, K.; Tess, B.

1989-01-01

This book outlines the various procedures necessary for the successful practice of diagnostic radiology. Topics covered are: general principles, imaging of the urinary and gastrointestinal tracts, vascular radiology, arthrography, and miscellaneous diagnostic radiologic procedures

Plant diagnostics in power stations

International Nuclear Information System (INIS)

Sturm, A.; Doering, D.

1985-01-01

The method of noise diagnostics is dealt with as a part of plant diagnostics in nuclear power stations. The following special applications are presented: (1) The modular noise diagnostics system is used for monitoring primary coolant circuits and detecting abnormal processes due to mechanical vibrations, loose parts or leaks. (2) The diagnostics of machines and plants with antifriction bearings is based on bearing vibration measurements. (3) The measurement of the friction moment by means of acoustic emission analysis is used for evaluating the operational state of slide bearings

Negative symptom domain prevalence across diagnostic boundaries: The relevance of diagnostic shifts.

Science.gov (United States)

Lyne, John; Renwick, Laoise; O'Donoghue, Brian; Kinsella, Anthony; Malone, Kevin; Turner, Niall; O'Callaghan, Eadbhard; Clarke, Mary

2015-08-30

Negative symptoms are included in diagnostic manuals as part of criteria for schizophrenia spectrum psychoses only, however some studies have found their presence in other diagnoses. This study sought to clarify negative symptom domain prevalence across diagnostic categories, while investigating whether negative symptoms predicted diagnostic shift over time. Scale for the Assessment of Negative Symptoms (SANS) data were collected at first presentation in 197 individuals presenting with first episode psychosis and again at one year follow-up assessment. Negative symptoms were highest among individuals with schizophrenia and among those whose diagnosis shifted from non-schizophrenia spectrum at baseline to schizophrenia spectrum at follow-up. In a non-schizophrenia spectrum group negative symptoms at baseline were not a significant predictor of diagnostic shift to schizophrenia spectrum diagnoses. The study suggests negative symptoms can present among individuals with non-schizophrenia spectrum diagnoses, although this is most relevant for individuals following diagnostic shift from non-schizophrenia spectrum to schizophrenia spectrum diagnoses. The findings support introduction of a negative symptom dimension when describing a range of psychotic illnesses, and indicate that further research investigating the evolution of negative symptoms in non-schizophrenia diagnoses is needed. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Diagnostic grand rounds: A new teaching concept to train diagnostic reasoning

International Nuclear Information System (INIS)

Stieger, Stefan; Praschinger, Andrea; Kletter, Kurt; Kainberger, Franz

2011-01-01

Introduction: Diagnostic reasoning is a core skill in teaching and learning in undergraduate curricula. Diagnostic grand rounds (DGRs) as a subform of grand rounds are intended to train the students' skills in the selection of appropriate tests and in the interpretation of test results. The aim of this study was to test DGRs for their ability to improve diagnostic reasoning by using a pre-post-test design. Methods: During one winter term, all 398 fifth-year students (36.1% male, 63.9% female) solved 23 clinical cases presented in 8 DGRs. In an online questionnaire, a Diagnostic Thinking Inventory (DTI) with 41 items was evaluated for flexibility in thinking and structure of knowledge in memory. Results were correlated with those from a summative multiple-choice knowledge test and of the learning objectives in a logbook. Results: The students' DTI scores in the post-test were significantly higher than those reported in the pre-test. DTI scores at either testing time did not correlate with medical knowledge as assessed by a multiple-choice knowledge test. Abilities acquired during clinical clerkships as documented in a logbook could only account for a small proportion of the increase in the flexibility subscale score. This effect still remained significant after accounting for potential confounders. Conclusion: Establishing DGRs proofed to be an effective way of successfully improving both students' diagnostic reasoning and the ability to select the appropriate test method in routine clinical practice.

Diagnostic grand rounds: A new teaching concept to train diagnostic reasoning

Energy Technology Data Exchange (ETDEWEB)

Stieger, Stefan, E-mail: stefan.stieger@univie.ac.at [Department of Basic Psychological Research, School of Psychology, University of Vienna, Liebiggasse 5, A-1010 Vienna (Austria); Praschinger, Andrea, E-mail: andrea.praschinger@meduniwien.ac.at [Core Unit for Medical Education (BEMAW), Medical University of Vienna, Spitalgasse 23, BT87, P.O. 10, A-1097 Vienna (Austria); Kletter, Kurt, E-mail: kurt.kletter@meduniwien.ac.at [Department of Nuclear Medicine, General Hospital of Vienna, Waehringer Guertel 18-20, A-1090 Vienna (Austria); Kainberger, Franz, E-mail: franz.kainberger@meduniwien.ac.at [Department of Radiology, General Hospital of Vienna, Waehringer Guertel 18-20, A-1090 Vienna (Austria)

2011-06-15

Introduction: Diagnostic reasoning is a core skill in teaching and learning in undergraduate curricula. Diagnostic grand rounds (DGRs) as a subform of grand rounds are intended to train the students' skills in the selection of appropriate tests and in the interpretation of test results. The aim of this study was to test DGRs for their ability to improve diagnostic reasoning by using a pre-post-test design. Methods: During one winter term, all 398 fifth-year students (36.1% male, 63.9% female) solved 23 clinical cases presented in 8 DGRs. In an online questionnaire, a Diagnostic Thinking Inventory (DTI) with 41 items was evaluated for flexibility in thinking and structure of knowledge in memory. Results were correlated with those from a summative multiple-choice knowledge test and of the learning objectives in a logbook. Results: The students' DTI scores in the post-test were significantly higher than those reported in the pre-test. DTI scores at either testing time did not correlate with medical knowledge as assessed by a multiple-choice knowledge test. Abilities acquired during clinical clerkships as documented in a logbook could only account for a small proportion of the increase in the flexibility subscale score. This effect still remained significant after accounting for potential confounders. Conclusion: Establishing DGRs proofed to be an effective way of successfully improving both students' diagnostic reasoning and the ability to select the appropriate test method in routine clinical practice.

ITER diagnostic system: Vacuum interface

Energy Technology Data Exchange (ETDEWEB)

Patel, K.M., E-mail: Kaushal.Patel@iter.org [ITER Organization, Route de Vinon sur Verdon, 13115 St Paul-Lez-Durance (France); Udintsev, V.S.; Hughes, S.; Walker, C.I.; Andrew, P.; Barnsley, R.; Bertalot, L. [ITER Organization, Route de Vinon sur Verdon, 13115 St Paul-Lez-Durance (France); Drevon, J.M. [Bertin Technologies, BP 22, 13762 Aix-en Provence cedex 3 (France); Encheva, A. [ITER Organization, Route de Vinon sur Verdon, 13115 St Paul-Lez-Durance (France); Kashchuk, Y. [Institution “PROJECT CENTER ITER”, 1, Akademika Kurchatova pl., Moscow (Russian Federation); Maquet, Ph. [Bertin Technologies, BP 22, 13762 Aix-en Provence cedex 3 (France); Pearce, R.; Taylor, N.; Vayakis, G.; Walsh, M.J. [ITER Organization, Route de Vinon sur Verdon, 13115 St Paul-Lez-Durance (France)

2013-10-15

Diagnostics play an essential role for the successful operation of the ITER tokamak. They provide the means to observe control and to measure plasma during the operation of ITER tokamak. The components of the diagnostic system in the ITER tokamak will be installed in the vacuum vessel, in the cryostat, in the upper, equatorial and divertor ports, in the divertor cassettes and racks, as well as in various buildings. Diagnostic components that are placed in a high radiation environment are expected to operate for the life of ITER. There are approx. 45 diagnostic systems located on ITER. Some diagnostics incorporate direct or independently pumped extensions to maintain their necessary vacuum conditions. They require a base pressure less than 10{sup −7} Pa, irrespective of plasma operation, and a leak rate of less than 10{sup −10} Pa m{sup 3} s{sup −1}. In all the cases it is essential to maintain the ITER closed fuel cycle. These directly coupled diagnostic systems are an integral part of the ITER vacuum containment and are therefore subject to the same design requirements for tritium and active gas confinement, for all normal and accidental conditions. All the diagnostics, whether or not pumped, incorporate penetration of the vacuum boundary (i.e. window assembly, vacuum feedthrough etc.) and demountable joints. Monitored guard volumes are provided for all elements of the vacuum boundary that are judged to be vulnerable by virtue of their construction, material, load specification etc. Standard arrangements are made for their construction and for the monitoring, evacuating and leak testing of these volumes. Diagnostic systems are incorporated at more than 20 ports on ITER. This paper will describe typical and particular arrangements of pumped diagnostic and monitored guard volume. The status of the diagnostic vacuum systems, which are at the start of their detailed design, will be outlined and the specific features of the vacuum systems in ports and extensions

ITER diagnostic system: Vacuum interface

International Nuclear Information System (INIS)

Patel, K.M.; Udintsev, V.S.; Hughes, S.; Walker, C.I.; Andrew, P.; Barnsley, R.; Bertalot, L.; Drevon, J.M.; Encheva, A.; Kashchuk, Y.; Maquet, Ph.; Pearce, R.; Taylor, N.; Vayakis, G.; Walsh, M.J.

2013-01-01

Diagnostics play an essential role for the successful operation of the ITER tokamak. They provide the means to observe control and to measure plasma during the operation of ITER tokamak. The components of the diagnostic system in the ITER tokamak will be installed in the vacuum vessel, in the cryostat, in the upper, equatorial and divertor ports, in the divertor cassettes and racks, as well as in various buildings. Diagnostic components that are placed in a high radiation environment are expected to operate for the life of ITER. There are approx. 45 diagnostic systems located on ITER. Some diagnostics incorporate direct or independently pumped extensions to maintain their necessary vacuum conditions. They require a base pressure less than 10 −7 Pa, irrespective of plasma operation, and a leak rate of less than 10 −10 Pa m 3 s −1 . In all the cases it is essential to maintain the ITER closed fuel cycle. These directly coupled diagnostic systems are an integral part of the ITER vacuum containment and are therefore subject to the same design requirements for tritium and active gas confinement, for all normal and accidental conditions. All the diagnostics, whether or not pumped, incorporate penetration of the vacuum boundary (i.e. window assembly, vacuum feedthrough etc.) and demountable joints. Monitored guard volumes are provided for all elements of the vacuum boundary that are judged to be vulnerable by virtue of their construction, material, load specification etc. Standard arrangements are made for their construction and for the monitoring, evacuating and leak testing of these volumes. Diagnostic systems are incorporated at more than 20 ports on ITER. This paper will describe typical and particular arrangements of pumped diagnostic and monitored guard volume. The status of the diagnostic vacuum systems, which are at the start of their detailed design, will be outlined and the specific features of the vacuum systems in ports and extensions will be described

Three-dimensional structure of the Trypanosome flagellum suggests that the paraflagellar rod functions as a biomechanical spring.

Directory of Open Access Journals (Sweden)

Louise C Hughes

Full Text Available Flagellum motility is critical for normal human development and for transmission of pathogenic protozoa that cause tremendous human suffering worldwide. Biophysical principles underlying motility of eukaryotic flagella are conserved from protists to vertebrates. However, individual cells exhibit diverse waveforms that depend on cell-specific elaborations on basic flagellum architecture. Trypanosoma brucei is a uniflagellated protozoan parasite that causes African sleeping sickness. The T. brucei flagellum is comprised of a 9+2 axoneme and an extra-axonemal paraflagellar rod (PFR, but the three-dimensional (3D arrangement of the underlying structural units is poorly defined. Here, we use dual-axis electron tomography to determine the 3D architecture of the T. brucei flagellum. We define the T. brucei axonemal repeating unit. We observe direct connections between the PFR and axonemal dyneins, suggesting a mechanism by which mechanochemical signals may be transmitted from the PFR to axonemal dyneins. We find that the PFR itself is comprised of overlapping laths organized into distinct zones that are connected through twisting elements at the zonal interfaces. The overall structure has an underlying 57 nm repeating unit. Biomechanical properties inferred from PFR structure lead us to propose that the PFR functions as a biomechanical spring that may store and transmit energy derived from axonemal beating. These findings provide insight into the structural foundations that underlie the distinctive flagellar waveform that is a hallmark of T. brucei cell motility.

Technology Issues of Burning Plasma Diagnostics

International Nuclear Information System (INIS)

Kaye, A. S.

2008-01-01

The ITER Tokamak will require many diagnostics both for safe and reliable operation of the machine and for understanding of the physics underlying the performance. The design of these diagnostics raises many challenging technical issues not faced on smaller machines. These arise partly from the increase demands on established diagnostics arising from the increased size, higher magnetic field, large heating power, and in particular the dramatically longer pulse duration of ITER, which make issue such as power loading on first wall components more challenging. The demands on reliability and availability of the machine in order to achieve the objectives within the agreed time schedule also place severe additional demands on the design, quality assurance and maintainability of diagnostics. ITER will produce many orders of magnitude more neutrons than previous Tokamaks and will be a licensed nuclear facility. This has important implications for the traceability, quality assurance and availability of safety critical diagnostics, and for the control of the design and procurement of all diagnostics. The high neutron flux/fluence also constrains the design of diagnostics, which must offer shielding consistent with the allowable dose rates on critical components of the Tokamak, and themselves be tolerant of the radiation level at the diagnostic. This paper presents an overview of the more critical issues for ITER diagnostics

Diagnostic system and diagnostic experiences at the Paks Nuclear Power Plant

International Nuclear Information System (INIS)

Katona, Tamas

1986-01-01

The major functions of the diagnostic system of the first two units of the Paks Nuclear Power Plant are as follows: monitoring the mechanical integrity of the reactor and the primary coolant circuit by means of vibration diagnostics; leakage detection of the primary coolant circuit by means of high frequency sonic analysis; loose parts monitoring based on the analysis of high frequency signals of acceleration detectors; and monitoring the vibration state of the turbines and rotary machines by the latter method or by a procedure based on the detection of mechanical vibrations. Up-to-date vibration diagnostics is based on the information supplied by either acceleration detectors or pressure fluctuation detectors, or in-core and ex-core neutron detectors. (V.N.)

MFTF-B plasma-diagnostic system

International Nuclear Information System (INIS)

Throop, A.L.; Goerz, D.A.; Thomas, S.R.

1981-01-01

This paper describes the current design status of the plasma diagnostic system for MFTF-B. In this paper we describe the system requirement changes which have occurred as a result of the funded rescoping of the original MFTF facility into MFTF-B. We outline the diagnostic instruments which are currently planned, and present an overview of the diagnostic system

The impact of new trends in POCTs for companion diagnostics, non-invasive testing and molecular diagnostics.

Science.gov (United States)

Huckle, David

2015-06-01

Point-of-care diagnostics have been slowly developing over several decades and have taken on a new importance in current healthcare delivery for both diagnostics and development of new drugs. Molecular diagnostics have become a key driver of technology change and opened up new areas in companion diagnostics for use alongside pharmaceuticals and in new clinical approaches such as non-invasive testing. Future areas involving smartphone and other information technology advances, together with new developments in molecular biology, microfluidics and surface chemistry are adding to advances in the market. The focus for point-of-care tests with molecular diagnostic technologies is focused on advancing effective applications.

Team building and diagnostic training

International Nuclear Information System (INIS)

Bulmer, S.

1987-01-01

While developing a commercial training program to improve teamwork in control room crews, General Electric's Nuclear Training Services made an important discovery. Traditional training methods for developing teamwork and enhancing diagnostics capabilities are incomplete. Traditional methods generally help, but fail to fulfill the long-term needs of most teams. Teamwork has been treated as a short-term performance problem. Traditional diagnostic training suffers from a similar problem. Too often, it covers only the basic principles of decision-making, ignoring the development of expert diagnostic capabilities. In response to this discovery, they have developed comprehensive training in Team Building and Diagnostics

Original Research Polymerase chain reaction identification of ...

African Journals Online (AJOL)

Molecular identification of T. b. rhodesiense in tsetse flies 11 ... Glossina bravepalpis, and Glossina fuscipes fuscipes5-7) are mainly confined ..... that the feeding habits of these flies are similar to one ... well established that Glossina morsitans morsitans are efficient ... some people.26,27 Notably, the high infection rates that.

The engineering of JET diagnostics

International Nuclear Information System (INIS)

Walker, C.I.; Dillon, S.F.; Hammond, N.P.; Hancock, C.J.; Lam, N.; McCarron, E.J.; Prior, P.C.S.; Reid, J.; Sanders, S.; Tellier, X.; Tiscornia, A.J.; Whitfield, G.A.H.; Wilson, C.H.; Wilson, D.J.

1995-01-01

There are some 62 identifiably different diagnostic systems on JET. 22 were installed new at the last, Pumped Divertor, shutdown and a further 22 which were modified, upgraded or repositioned. This paper describes some of the engineering aspects peculiar to the renewed diagnostic systems, reviews their construction and installation and gives an overview of the design of presently installed diagnostic equipment at the Torus. Examples are considered that illustrate the breakdown into a categorisation based on their installation method. This is useful for discussion of many of the associated engineering problems of method and quality control of manufacture, vulnerability, access for installation and maintenance and ultimately system safety and reliability. The function and measured plasma parameter of specific diagnostics is covered in other papers and is not attempted here, neither is a full catalogue of Diagnostics on JET. (orig.)

Corpuscular plasma diagnostics

International Nuclear Information System (INIS)

Afrosimov, V.; Petrov, M.

1984-01-01

An elementary explanation is presented of the physical principles and important methods of corpuscular plasma diagnostics. The invaluable role of corpuscular methods for measuring the hot plasma ion component in thermonuclear facilities, especially hydrogen ions in tokamaks, is emphasized. All corpuscular methods employ analysis of fast neutral atoms and therefore the mechanism of their creation inside a hot plasma is explained first. The ammount of information obtainable from spectra of fast neutrals is discussed. Multichannel analyzers developed at the FTI A.F. Ioffe in Leningrad are described in detail. Classical passive corpuscular diagnostics are examined as are active methods using artifitial beams of hydrogen atoms. The method used for obtaining local values of ion temperature and density is explained. Corpuscular spectroscopic diagnostics and its application for measuring impurities is mentioned. (J.U.)

Nova diagnostics summary

International Nuclear Information System (INIS)

Slivinsky, V.W.; Drake, R.P.

1985-01-01

The authors intend that Nova be the best diagnosed ICF research facility in operation today. The authors experience in providing advanced diagnostics for previous laser systems will be extended at Nova, and will be challenged by the development of new instrumentation to diagnose the more advanced targets made possible by this powerful laser. Previous experience has shown that to understand target performance, the authors must have as complete a set of diagnostics as possible. The Nova diagnostics are divided into two sets: the basic set required for the initial Nova experiments and the more advanced set for later, generally more complex, experiments. The basic set will be operational for the first Nova shots; it was a Nova line item funded with Nova construction money. This basic set is presented in a table

A Framework to Debug Diagnostic Matrices

Science.gov (United States)

Kodal, Anuradha; Robinson, Peter; Patterson-Hine, Ann

2013-01-01

Diagnostics is an important concept in system health and monitoring of space operations. Many of the existing diagnostic algorithms utilize system knowledge in the form of diagnostic matrix (D-matrix, also popularly known as diagnostic dictionary, fault signature matrix or reachability matrix) gleaned from physical models. But, sometimes, this may not be coherent to obtain high diagnostic performance. In such a case, it is important to modify this D-matrix based on knowledge obtained from other sources such as time-series data stream (simulated or maintenance data) within the context of a framework that includes the diagnostic/inference algorithm. A systematic and sequential update procedure, diagnostic modeling evaluator (DME) is proposed to modify D-matrix and wrapper logic considering least expensive solution first. This iterative procedure includes conditions ranging from modifying 0s and 1s in the matrix, or adding/removing the rows (failure sources) columns (tests). We will experiment this framework on datasets from DX challenge 2009.

Corporal diagnostic work and diagnostic spaces: clinicians' use of space and bodies during diagnosis.

Science.gov (United States)

Gardner, John; Williams, Clare

2015-06-01

An emerging body of literature in sociology has demonstrated that diagnosis is a useful focal point for understanding the social dimensions of health and illness. This article contributes to this work by drawing attention to the relationship between diagnostic spaces and the way in which clinicians use their own bodies during the diagnostic process. As a case study, we draw upon fieldwork conducted with a multidisciplinary clinical team providing deep brain stimulation (DBS) to treat children with a movement disorder called dystonia. Interviews were conducted with team members and diagnostic examinations were observed. We illustrate that clinicians use communicative body work and verbal communication to transform a material terrain into diagnostic space, and we illustrate how this diagnostic space configures forms of embodied 'sensing-and-acting' within. We argue that a 'diagnosis' can be conceptualised as emerging from an interaction in which space, the clinician-body, and the patient-body (or body-part) mutually configure one another. By conceptualising diagnosis in this way, this article draws attention to the corporal bases of diagnostic power and counters Cartesian-like accounts of clinical work in which the patient-body is objectified by a disembodied medical discourse. © 2015 The Authors. Sociology of Health & Illness © 2015 Foundation for the Sociology of Health & Illness.

Skeletal diseases. Diagnostic clinical radiology and differential diagnostics. 2. rev. and enl. ed.

International Nuclear Information System (INIS)

Freyschmidt, J.

1997-01-01

The book focuses on the diagnostic evaluation of idiopathic diseases of the skeleton and bone joints, also including the fundamental healing processes of bone fractures, particularly of stress-induced and pathologic fractures. Ample space has been given to the description and imaging of the course of diseases under treatment by up-to-date therapies, as e.g. for ostitis deformans Paget's disease, or skeletal metastases. This second edition of the book incorporates the progress achieved over the last five years in skeletal diagnostics. The advances in this field have been resulting from basic research work, for instance in molecular biology, or from a variety of completed studies relating to clinical medicine, laboratory chemistry, histopathology and radiology of skeletal diseases, and from experience obtained with the diagnostic radiology methods and techniques, with the potentials and constraints of magnetic resonance imaging (MRI) today being more critically assessed than five years ago. MRI is a modality currently meeting with interest in the context of search for additional diagnostic information, new definition of complete pictures of diseases, or false or overinterpretation of diagnostic findings. (orig./MG). 431 figs [de

Deposition Diagnostics for Next-step Devices

International Nuclear Information System (INIS)

Skinner, C.H.; Roquemore, A.L.; Bader, A.; Wampler, W.R.

2004-01-01

The scale-up of deposition in next-step devices such as ITER will pose new diagnostic challenges. Codeposition of hydrogen with carbon needs to be characterized and understood in the initial hydrogen phase in order to mitigate tritium retention and qualify carbon plasma facing components for DT operations. Plasma facing diagnostic mirrors will experience deposition that is expected to rapidly degrade their reflectivity, posing a new challenge to diagnostic design. Some eroded particles will collect as dust on interior surfaces and the quantity of dust will be strictly regulated for safety reasons - however diagnostics of in-vessel dust are lacking. We report results from two diagnostics that relate to these issues. Measurements of deposition on NSTX with 4 Hz time resolution have been made using a quartz microbalance in a configuration that mimics that of a typical diagnostic mirror. Often deposition was observed immediately following the discharge suggesting that diagnostic shutters should be closed as soon as possible after the time period of interest. Material loss was observed following a few discharges. A novel diagnostic to detect surface particles on remote surfaces was commissioned on NSTX

Proposed Diagnostic Criteria for Smartphone Addiction.

Science.gov (United States)

Lin, Yu-Hsuan; Chiang, Chih-Lin; Lin, Po-Hsien; Chang, Li-Ren; Ko, Chih-Hung; Lee, Yang-Han; Lin, Sheng-Hsuan

2016-01-01

Global smartphone penetration has led to unprecedented addictive behaviors. The aims of this study are to develop diagnostic criteria of smartphone addiction and to examine the discriminative ability and the validity of the diagnostic criteria. We developed twelve candidate criteria for characteristic symptoms of smartphone addiction and four criteria for functional impairment caused by excessive smartphone use. The participants consisted of 281 college students. Each participant was systematically assessed for smartphone-using behaviors by psychiatrist's structured diagnostic interview. The sensitivity, specificity, and diagnostic accuracy of the candidate symptom criteria were analyzed with reference to the psychiatrists' clinical global impression. The optimal model selection with its cutoff point of the diagnostic criteria differentiating the smartphone addicted subjects from non-addicted subjects was then determined by the best diagnostic accuracy. Six symptom criteria model with optimal cutoff point were determined based on the maximal diagnostic accuracy. The proposed smartphone addiction diagnostic criteria consisted of (1) six symptom criteria, (2) four functional impairment criteria and (3) exclusion criteria. Setting three symptom criteria as the cutoff point resulted in the highest diagnostic accuracy (84.3%), while the sensitivity and specificity were 79.4% and 87.5%, respectively. We suggested determining the functional impairment by two or more of the four domains considering the high accessibility and penetration of smartphone use. The diagnostic criteria of smartphone addiction demonstrated the core symptoms "impaired control" paralleled with substance related and addictive disorders. The functional impairment involved multiple domains provide a strict standard for clinical assessment.

Proposed Diagnostic Criteria for Smartphone Addiction.

Directory of Open Access Journals (Sweden)

Yu-Hsuan Lin

Full Text Available Global smartphone penetration has led to unprecedented addictive behaviors. The aims of this study are to develop diagnostic criteria of smartphone addiction and to examine the discriminative ability and the validity of the diagnostic criteria.We developed twelve candidate criteria for characteristic symptoms of smartphone addiction and four criteria for functional impairment caused by excessive smartphone use. The participants consisted of 281 college students. Each participant was systematically assessed for smartphone-using behaviors by psychiatrist's structured diagnostic interview. The sensitivity, specificity, and diagnostic accuracy of the candidate symptom criteria were analyzed with reference to the psychiatrists' clinical global impression. The optimal model selection with its cutoff point of the diagnostic criteria differentiating the smartphone addicted subjects from non-addicted subjects was then determined by the best diagnostic accuracy.Six symptom criteria model with optimal cutoff point were determined based on the maximal diagnostic accuracy. The proposed smartphone addiction diagnostic criteria consisted of (1 six symptom criteria, (2 four functional impairment criteria and (3 exclusion criteria. Setting three symptom criteria as the cutoff point resulted in the highest diagnostic accuracy (84.3%, while the sensitivity and specificity were 79.4% and 87.5%, respectively. We suggested determining the functional impairment by two or more of the four domains considering the high accessibility and penetration of smartphone use.The diagnostic criteria of smartphone addiction demonstrated the core symptoms "impaired control" paralleled with substance related and addictive disorders. The functional impairment involved multiple domains provide a strict standard for clinical assessment.

Laser-aided plasma diagnostics

NARCIS (Netherlands)

Donne, A. J. H.; Barth, C. J.

2008-01-01

This paper will focus on two types of laser-aided diagnostics: Thomson scattering and laser-induced fluorescence. Thomson scattering is a very powerful diagnostic, which is applied at nearly every magnetic confinement device. Depending on the experimental conditions different plasma parameters can

Ongoing experiments: diagnostics requirements

International Nuclear Information System (INIS)

Dickerman, C.E.

1976-01-01

The paper reviews the fuel motion diagnostics needs for ongoing LMFBR safety experiments over approximately the next five years, with the discussion centered on TREAT. Brief comments on the direction in which clad motion diagnostics requirements are expected to develop are also presented

Gearbox vibration diagnostic analyzer

Science.gov (United States)

1992-01-01

This report describes the Gearbox Vibration Diagnostic Analyzer installed in the NASA Lewis Research Center's 500 HP Helicopter Transmission Test Stand to monitor gearbox testing. The vibration of the gearbox is analyzed using diagnostic algorithms to calculate a parameter indicating damaged components.

Recent diagnostic developments on LHD

International Nuclear Information System (INIS)

Sudo, S.; Nagayama, Y.; Peterson, B.J.

2003-01-01

Standard diagnostics for fundamental plasma parameters and for plasma physics are routinely utilized for daily operation and physics study in the large helical device (LHD) with high reliability. Diagnostics for steady state plasma are intensively developed, especially for T e , n e (YAG laser Thomson, CO 2 laser polarimeter), data acquisition in steady state, heat resistant probes. To clarify the plasma property of the helical structure, 2-D or 3-D diagnostics are intensively developed: Tangential cameras (Fast SX TV, Photon counting CCD, H α TV); Tomography (Tangential SX CCD, Bolometer); Imaging (Bolometer, ECE, Reflectometer). Divertor and edge physics are one of important key issues for steady state operation. Diagnostics for neutral flux (H α array, Zeeman spectroscopy) and n e (Fast scanning probe, Li beam probe, Pulsed radar reflectometer). In addition to these, advanced diagnostics are being intensively developed with national and international collaborations in LHD. (author)

Partial nucleotide sequence analysis of 18S ribosomal RNA gene of the four genotypes of Trypanosoma congolense

International Nuclear Information System (INIS)

Osanya, A.; Majiwa, P.A.O.; Kinyanjui, P.W.

2006-01-01

Specific oligonucleotide primers based on conserved nucleotide sequences of 18s ribisomal RNA (18s rRNA) gene of Trypanosoma brucei, Leishmania donovani, Triponema aequale and Lagenidium gigantum have been designed and used in the ploymerase chain reaction (PCR) to amplify genomic DNA from four different clones each representing a different genotypic group of T. congolence. PCR products of approximately 1Kb were generated using as template DNA from each of the trypanosomes. The PCR products cross-hybridized with genomic DNA from T.brucei, T. simiae and the four genotypes of T.congolense implying significant sequence homology of 18S rRNA gene among trypanosomes. The nucleotide sequence of a segment of the PCR products were determined by direct sequencing to provide partial nucleotide sequence of the 18s rRNA gene in each T.congolense genotypic group. The sequences obtained together with those that have been published for T.brucei reveals that although most regions show inter and intra species nucleotide identity, there are several sites where deletions, insertions and base changes have occured in nucleotide sequence of of T.brucei and the four genotypes of T.congolense.(author)

A diagnostic methodology for refrigerating systems; Methodologie de diagnostic des installations frigorifiques

Energy Technology Data Exchange (ETDEWEB)

Vrinat, G. [Association Francaise du Froid (AFF), 75 - Paris (France)

1997-12-31

A diagnostic methodology for refrigerating machines, equipment and plants has been defined and evaluated for EDF, the French national power utility and ADEME, the French Agency for Energy Conservation, in the framework of energy conservation objectives: the diagnostic method should enable to identify malfunctions, assess the cost efficiency of the equipment, identify limiting factors, and consider corrective measures

Antiparasitic nitroimidazoles. 8. Derivatives of 2-(4-formylstyryl)-5-nitro-1-vinylimidazole.

Science.gov (United States)

Ross, W J; Jamieson, W B

1975-02-01

A series of 33 thioacetals and hydrazones of 2-(4-formylstyryl)-5-nitro-1-vinylimidazole was prepared and examined for antitrypanosomal properties. The thioacetals were inactive as antitrypanosomal agents but three hydrazones derived from N-aminoguanidine, pyridylacethohydrazide chloride (Girard reagent P), and dimethylaminoacetohydrazide (Girard reagent D) displayed good activity against Trypanosoma rhodesiense.

Microfluidic technology for molecular diagnostics.

Science.gov (United States)

Robinson, Tom; Dittrich, Petra S

2013-01-01

Molecular diagnostics have helped to improve the lives of millions of patients worldwide by allowing clinicians to diagnose patients earlier as well as providing better ongoing therapies. Point-of-care (POC) testing can bring these laboratory-based techniques to the patient in a home setting or to remote settings in the developing world. However, despite substantial progress in the field, there still remain many challenges. Progress in molecular diagnostics has benefitted greatly from microfluidic technology. This chapter aims to summarise the more recent advances in microfluidic-based molecular diagnostics. Sections include an introduction to microfluidic technology, the challenges of molecular diagnostics, how microfluidic advances are working to solve these issues, some alternative design approaches, and detection within these systems.

Diagnostic criteria in MR neurography

International Nuclear Information System (INIS)

Baeumer, P.

2017-01-01

Peripheral neuropathies are frequent and can mostly be correctly diagnosed by clinical examination and electrophysiology; however, diagnostically difficult cases are sometimes encountered especially with respect to precise localization of nerve lesions. Imaging of the peripheral nervous system has been shown to provide additional useful diagnostic information. In addition to the more widely available nerve sonography, magnetic resonance neurography (MRN) is the method of choice in diagnostically complex cases. The most important pulse sequence is a T2-weighted fat-saturated pulse sequence with high in-plane resolution and detects increased T2-weighted signals of nerve fascicles as a highly sensitive sign for nerve lesions. Further established diagnostic criteria are nerve caliber and, less commonly used, contrast agent uptake. The spatial pattern of nerve lesions aids in the diagnostic classification of neuropathies. Functional imaging techniques, such as diffusion tensor imaging (DTI) and nerve perfusion are currently under examination with respect to the clinical potential. If all other diagnostic methods, including clinical examination, electrophysiology and nerve sonography do not arrive at an unambiguous diagnosis of a peripheral neuropathy, MRN should be used. The special value of MRN is demonstrated particularly in complex nerve lesions, such as traumatic plexopathies and in partial fascicular neuropathies and many other indications. (orig.) [de

Development of new diagnostics for WEST

International Nuclear Information System (INIS)

Lotte, P.; Moreau, P.; Gil, C.

2015-01-01

WEST, the upgraded superconducting tokamak Tore Supra, will be an international experimental platform aimed to support ITER Physics program. The main objective of WEST is to provide relevant plasma conditions for validating plasma facing component (PFC) technology, in particular the actively cooled Tungsten divertor monoblocks, and also assessing high heat flux and high fluence plasma wall interactions with Tungsten in order to prepare ITER divertor operation. In parallel, WEST will also open new experimental opportunities for developing integrated H mode operation and exploring steady state scenarios in a metallic environment. In order to fulfil the Scientific Program of WEST, new diagnostics have been developed in addition to the already existing diagnostics of Tore Supra, modified and improved during the shutdown. For the PFC technology validation program, new tools have been implemented, like a full infrared survey of the PFC, a new calorimetry system, local temperature measurements (thermocouple and Bragg grating optical fiber), and several sets of Langmuir probes. For the analysis of long pulse H mode operation, new plasma diagnostics will be implemented, among which the Visible Spectroscopy diagnostic for W sources and transport studies, the Soft-Xray diagnostic based on gas electron multiplier detectors for transport and MHD studies, the X-ray imaging crystal spectroscopy diagnostic with advanced solid state detector properties for ion temperature, ion density and plasma rotation velocity measurements, and the ECE Imaging diagnostic for MHD and turbulence studies. Most of these new diagnostics are developed with the participation of French Universities or through international collaborations. This paper focuses on the description of these four plasma diagnostics. (author)

Nova target diagnostics control system

International Nuclear Information System (INIS)

Severyn, J.R.

1985-01-01

During the past year the Nova target diagnostics control system was finished and put in service. The diagnostics loft constructed to the north of the target room provides the environmental conditions required to collect reliable target diagnostic data. These improvements include equipment cooling and isolation of the power source with strict control of instrumentation grounds to eliminate data corruption due to electromagnetic pulses from the laser power-conditioning system or from target implosion effects

Towards an Early Warning System for Rhodesian Sleeping Sickness in Savannah Areas: Man-Like Traps for Tsetse Flies

Science.gov (United States)

Vale, Glyn A.; Hall, David R.; Chamisa, Andrew; Torr, Stephen J.

2012-01-01

Background In the savannahs of East and Southern Africa, tsetse flies (Glossina spp.) transmit Trypanosoma brucei rhodesiense which causes Rhodesian sleeping sickness, the zoonotic form of human African trypanosomiasis. The flies feed mainly on wild and domestic animals and are usually repelled by humans. However, this innate aversion to humans can be undermined by environmental stresses on tsetse populations, so increasing disease risk. To monitor changes in risk, we need traps designed specifically to quantify the responsiveness of savannah tsetse to humans, but the traps currently available are designed to simulate other hosts. Methodology/Principal Findings In Zimbabwe, two approaches were made towards developing a man-like trap for savannah tsetse: either modifying an ox-like trap or creating new designs. Tsetse catches from a standard ox-like trap used with and without artificial ox odor were reduced by two men standing nearby, by an average of 34% for Glossina morsitans morsitans and 56% for G. pallidipes, thus giving catches more like those made by hand-nets from men. Sampling by electrocuting devices suggested that the men stopped flies arriving near the trap and discouraged trap-entering responses. Most of human repellence was olfactory, as evidenced by the reduction in catches when the trap was used with the odor of hidden men. Geranyl acetone, known to occur in human odor, and dispensed at 0.2 mg/h, was about as repellent as human odor but not as powerfully repellent as wood smoke. New traps looking and smelling like men gave catches like those from men. Conclusion/Significance Catches from the completely new man-like traps seem too small to give reliable indices of human repellence. Better indications would be provided by comparing the catches of an ox-like trap either with or without artificial human odor. The chemistry and practical applications of the repellence of human odor and smoke deserve further study. PMID:23301107

Towards an early warning system for Rhodesian sleeping sickness in savannah areas: man-like traps for tsetse flies.

Directory of Open Access Journals (Sweden)

Glyn A Vale

Full Text Available BACKGROUND: In the savannahs of East and Southern Africa, tsetse flies (Glossina spp. transmit Trypanosoma brucei rhodesiense which causes Rhodesian sleeping sickness, the zoonotic form of human African trypanosomiasis. The flies feed mainly on wild and domestic animals and are usually repelled by humans. However, this innate aversion to humans can be undermined by environmental stresses on tsetse populations, so increasing disease risk. To monitor changes in risk, we need traps designed specifically to quantify the responsiveness of savannah tsetse to humans, but the traps currently available are designed to simulate other hosts. METHODOLOGY/PRINCIPAL FINDINGS: In Zimbabwe, two approaches were made towards developing a man-like trap for savannah tsetse: either modifying an ox-like trap or creating new designs. Tsetse catches from a standard ox-like trap used with and without artificial ox odor were reduced by two men standing nearby, by an average of 34% for Glossina morsitans morsitans and 56% for G. pallidipes, thus giving catches more like those made by hand-nets from men. Sampling by electrocuting devices suggested that the men stopped flies arriving near the trap and discouraged trap-entering responses. Most of human repellence was olfactory, as evidenced by the reduction in catches when the trap was used with the odor of hidden men. Geranyl acetone, known to occur in human odor, and dispensed at 0.2 mg/h, was about as repellent as human odor but not as powerfully repellent as wood smoke. New traps looking and smelling like men gave catches like those from men. CONCLUSION/SIGNIFICANCE: Catches from the completely new man-like traps seem too small to give reliable indices of human repellence. Better indications would be provided by comparing the catches of an ox-like trap either with or without artificial human odor. The chemistry and practical applications of the repellence of human odor and smoke deserve further study.

Socio-economic and cultural determinants of human african trypanosomiasis at the Kenya - Uganda transboundary.

Directory of Open Access Journals (Sweden)

Jane Jemeli Rutto

Full Text Available BACKGROUND: Kenya and Uganda have reported different Human African Trypanosomiasis incidences in the past more than three decades, with the latter recording more cases. This cross-sectional study assessed the demographic characteristics, tsetse and trypanosomiasis control practices, socio-economic and cultural risk factors influencing Trypanosoma brucei rhodesiense (T.b.r. infection in Teso and Busia Districts, Western Kenya and Tororo and Busia Districts, Southeast Uganda. A conceptual framework was postulated to explain interactions of various socio-economic, cultural and tsetse control factors that predispose individuals and populations to HAT. METHODS: A cross-sectional household survey was conducted between April and October 2008. Four administrative districts reporting T.b.r and lying adjacent to each other at the international boundary of Kenya and Uganda were purposely selected. Household data collection was carried out in two villages that had experienced HAT and one other village that had no reported HAT case from 1977 to 2008 in each district. A structured questionnaire was administered to 384 randomly selected household heads or their representatives in each country. The percent of respondents giving a specific answer was reported. Secondary data was also obtained on socio-economic and political issues in both countries. RESULTS: Inadequate knowledge on the disease cycle and intervention measures contributed considerable barriers to HAT, and more so in Uganda than in Kenya. Gender-associated socio-cultural practices greatly predisposed individuals to HAT. Pesticides-based crop husbandry in the 1970's reportedly reduced vector population while vegetation of coffee and banana's and livestock husbandry directly increased occurrence of HAT. Livestock husbandry practices in the villages were strong predictors of HAT incidence. The residents in Kenya (6.7% applied chemoprophylaxis and chemotherapeutic controls against trypanosomiasis to a

Using detergent to enhance detection sensitivity of African trypanosomes in human CSF and blood by loop-mediated isothermal amplification (LAMP.

Directory of Open Access Journals (Sweden)

Dennis J Grab

2011-08-01

Full Text Available The loop-mediated isothermal amplification (LAMP assay, with its advantages of simplicity, rapidity and cost effectiveness, has evolved as one of the most sensitive and specific methods for the detection of a broad range of pathogenic microorganisms including African trypanosomes. While many LAMP-based assays are sufficiently sensitive to detect DNA well below the amount present in a single parasite, the detection limit of the assay is restricted by the number of parasites present in the volume of sample assayed; i.e. 1 per µL or 10(3 per mL. We hypothesized that clinical sensitivities that mimic analytical limits based on parasite DNA could be approached or even obtained by simply adding detergent to the samples prior to LAMP assay.For proof of principle we used two different LAMP assays capable of detecting 0.1 fg genomic DNA (0.001 parasite. The assay was tested on dilution series of intact bloodstream form Trypanosoma brucei rhodesiense in human cerebrospinal fluid (CSF or blood with or without the addition of the detergent Triton X-100 and 60 min incubation at ambient temperature. With human CSF and in the absence of detergent, the LAMP detection limit for live intact parasites using 1 µL of CSF as the source of template was at best 10(3 parasites/mL. Remarkably, detergent enhanced LAMP assay reaches sensitivity about 100 to 1000-fold lower; i.e. 10 to 1 parasite/mL. Similar detergent-mediated increases in LAMP assay analytical sensitivity were also found using DNA extracted from filter paper cards containing blood pretreated with detergent before card spotting or blood samples spotted on detergent pretreated cards.This simple procedure for the enhanced detection of live African trypanosomes in biological fluids by LAMP paves the way for the adaptation of LAMP for the economical and sensitive diagnosis of other protozoan parasites and microorganisms that cause diseases that plague the developing world.

Using detergent to enhance detection sensitivity of African trypanosomes in human CSF and blood by loop-mediated isothermal amplification (LAMP).

Science.gov (United States)

Grab, Dennis J; Nikolskaia, Olga V; Inoue, Noboru; Thekisoe, Oriel M M; Morrison, Liam J; Gibson, Wendy; Dumler, J Stephen

2011-08-01

The loop-mediated isothermal amplification (LAMP) assay, with its advantages of simplicity, rapidity and cost effectiveness, has evolved as one of the most sensitive and specific methods for the detection of a broad range of pathogenic microorganisms including African trypanosomes. While many LAMP-based assays are sufficiently sensitive to detect DNA well below the amount present in a single parasite, the detection limit of the assay is restricted by the number of parasites present in the volume of sample assayed; i.e. 1 per µL or 10(3) per mL. We hypothesized that clinical sensitivities that mimic analytical limits based on parasite DNA could be approached or even obtained by simply adding detergent to the samples prior to LAMP assay. For proof of principle we used two different LAMP assays capable of detecting 0.1 fg genomic DNA (0.001 parasite). The assay was tested on dilution series of intact bloodstream form Trypanosoma brucei rhodesiense in human cerebrospinal fluid (CSF) or blood with or without the addition of the detergent Triton X-100 and 60 min incubation at ambient temperature. With human CSF and in the absence of detergent, the LAMP detection limit for live intact parasites using 1 µL of CSF as the source of template was at best 10(3) parasites/mL. Remarkably, detergent enhanced LAMP assay reaches sensitivity about 100 to 1000-fold lower; i.e. 10 to 1 parasite/mL. Similar detergent-mediated increases in LAMP assay analytical sensitivity were also found using DNA extracted from filter paper cards containing blood pretreated with detergent before card spotting or blood samples spotted on detergent pretreated cards. This simple procedure for the enhanced detection of live African trypanosomes in biological fluids by LAMP paves the way for the adaptation of LAMP for the economical and sensitive diagnosis of other protozoan parasites and microorganisms that cause diseases that plague the developing world.

Psychologists' diagnostic processes during a diagnostic interview

NARCIS (Netherlands)

Groenier, Marleen; Beerthuis, Vos R.J.; Pieters, Julius Marie; Witteman, C.L.M.; Witteman, Cilia L.M.; Swinkels, Jan A.

2011-01-01

In mental health care, psychologists assess clients’ complaints, analyze underlying problems, and identify causes for these problems, to make treatment decisions. We present a study on psychologists’ diagnostic processes, in which a mixed-method approach was employed. We aimed to identify a common

21 CFR 886.1380 - Diagnostic condensing lens.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Diagnostic condensing lens. 886.1380 Section 886...) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1380 Diagnostic condensing lens. (a) Identification. A diagnostic condensing lens is a device used in binocular indirect ophthalmoscopy (a procedure...

Pitfalls in diagnostic radiology

International Nuclear Information System (INIS)

Peh, Wilfred C.G.

2015-01-01

Only textbook to focus primarily on the topic of pitfalls in diagnostic radiology. Highlights the pitfalls in a comprehensive and systematic manner. Written by experts in different imaging modalities and subspecialties from reputable centers across the world. The practice of diagnostic radiology has become increasingly complex, with the use of numerous imaging modalities and division into many subspecialty areas. It is becoming ever more difficult for subspecialist radiologists, general radiologists, and residents to keep up with the advances that are occurring year on year, and this is particularly true for less familiar topics. Failure to appreciate imaging pitfalls often leads to diagnostic error and misinterpretation, and potential medicolegal problems. Diagnostic errors may be due to various factors such as inadequate imaging technique, imaging artifacts, failure to recognize normal structures or variants, lack of correlation with clinical and other imaging findings, and poor training or inexperience. Many, if not most, of these factors are potentially recognizable, preventable, or correctable. This textbook, written by experts from reputable centers across the world, systematically and comprehensively highlights the pitfalls that may occur in diagnostic radiology. Both pitfalls specific to different modalities and techniques and those specific to particular organ systems are described with the help of numerous high-quality illustrations. Recognition of these pitfalls is crucial in helping the practicing radiologist to achieve a more accurate diagnosis.

Pitfalls in diagnostic radiology

Energy Technology Data Exchange (ETDEWEB)

Peh, Wilfred C.G. (ed.) [Khoo Teck Puat Hospital (Singapore). Dept. of Diagnostic Radiology

2015-04-01

Only textbook to focus primarily on the topic of pitfalls in diagnostic radiology. Highlights the pitfalls in a comprehensive and systematic manner. Written by experts in different imaging modalities and subspecialties from reputable centers across the world. The practice of diagnostic radiology has become increasingly complex, with the use of numerous imaging modalities and division into many subspecialty areas. It is becoming ever more difficult for subspecialist radiologists, general radiologists, and residents to keep up with the advances that are occurring year on year, and this is particularly true for less familiar topics. Failure to appreciate imaging pitfalls often leads to diagnostic error and misinterpretation, and potential medicolegal problems. Diagnostic errors may be due to various factors such as inadequate imaging technique, imaging artifacts, failure to recognize normal structures or variants, lack of correlation with clinical and other imaging findings, and poor training or inexperience. Many, if not most, of these factors are potentially recognizable, preventable, or correctable. This textbook, written by experts from reputable centers across the world, systematically and comprehensively highlights the pitfalls that may occur in diagnostic radiology. Both pitfalls specific to different modalities and techniques and those specific to particular organ systems are described with the help of numerous high-quality illustrations. Recognition of these pitfalls is crucial in helping the practicing radiologist to achieve a more accurate diagnosis.

Climate Prediction Center: ENSO Diagnostic Discussion

Science.gov (United States)

Organization Search Go Search the CPC Go Expert Assessments ENSO Diagnostic Discussion Archive About Us Our Assessments > ENSO Diagnostic Discussion El Niño/Southern Oscillation (ENSO) Diagnostic Discussion PDF : English Version Spanish Version Adobe PDF Reader (Click icon for Adobe PDF Reader) Word: English Version

Target Diagnostics Supports NIF's Path to Ignition

International Nuclear Information System (INIS)

Shelton, R.

2011-01-01

The physics requirements derived from the National Ignition Facility (NIF) experimental campaigns are leading to a wide variety of target diagnostics. Software development for the control and analysis of these diagnostics is included in the NIF Integrated Computer Control System, Diagnostic Control System and Data Visualization. These projects implement the configuration, controls, data analysis and visual representation of most of these diagnostics. To date, over 40 target diagnostics have been developed to support NIF experiments. In 2011 diagnostics were developed or enhanced to measure Ignition performance in a high neutron yield environment. Performance is optimized around four key variables: Adiabat (a) which is the strength and timing of four shocks delivered to the target, Velocity (V) of the imploding target, Mix (M) is the uniformity of the burn, and the Shape (S) of the imploding Deuterium Tritium (DT) hot spot. The diagnostics used to measure each of these parameters is shown in figure 1. Adiabat is measured using the Velocity Interferometer System for Any Reflector (VISAR) diagnostic consisting of three streak cameras. To provide for more accurate adiabat measurements the VISAR streak cameras were enhanced in FY11 with a ten comb fiducial signal controller to allow for post shot correction of the streak camera sweep non-linearity. Mix is measured by the Neutron Time of Flight (NTOF) and Radiochemical Analysis of Gaseous Samples (RAGS) diagnostics. To accommodate high neutron yield shots, NTOF diagnostic controls are being modified to use Mach Zehnder interferometer signals to allow the digitizers to be moved from near the target chamber to the neutron shielded diagnostic mezzanine. In December 2011 the first phase of RAGS diagnostic commissioning will be completed. This diagnostic will analyze the tracers that are added to NIF target capsules that undergo nuclear reactions during the shot. These gases are collected and purified for nuclear counting by

Irradiation effects on plasma diagnostic components

International Nuclear Information System (INIS)

Nishitani, Takeo; Iida, Toshiyuki; Ikeda, Yujiro

1998-10-01

One of the most important issues to develop the diagnostics for the experimental thermonuclear reactor such as ITER is the irradiation effects on the diagnostics components. Typical neutron flux and fluence on the first wall are 1 MW/m 2 and 1 MWa/m 2 , respectively for ITER. In such radiation condition, most of the present diagnostics could not survive so that those will be planed to be installed far from the vacuum vessel. However, some diagnostics sensors such as bolometers and magnetic probes still have to be install inside vessel. And many transmission components for lights, wave and electric signals are inevitable even inside vessel. As a part of this R and D program of the ITER Engineering Design Activities (EDA), we carried out the irradiation tests on the basic materials of the transmission components and in-vessel diagnostics sensors in order to identify radiation hardened materials that can be used for diagnostic systems. (J.P.N.)

Irradiation effects on plasma diagnostic components

Energy Technology Data Exchange (ETDEWEB)

Nishitani, Takeo [ed.] [Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan). Naka Fusion Research Establishment; Iida, Toshiyuki; Ikeda, Yujiro [and others

1998-10-01

One of the most important issues to develop the diagnostics for the experimental thermonuclear reactor such as ITER is the irradiation effects on the diagnostics components. Typical neutron flux and fluence on the first wall are 1 MW/m{sup 2} and 1 MWa/m{sup 2}, respectively for ITER. In such radiation condition, most of the present diagnostics could not survive so that those will be planed to be installed far from the vacuum vessel. However, some diagnostics sensors such as bolometers and magnetic probes still have to be install inside vessel. And many transmission components for lights, wave and electric signals are inevitable even inside vessel. As a part of this R and D program of the ITER Engineering Design Activities (EDA), we carried out the irradiation tests on the basic materials of the transmission components and in-vessel diagnostics sensors in order to identify radiation hardened materials that can be used for diagnostic systems. (J.P.N.)

Saliva Preservative for Diagnostic Purposes

Science.gov (United States)

Pierson, Duane L.; Mehta, Satish K.

2012-01-01

Saliva is an important body fluid for diagnostic purposes. Glycoproteins, glucose, steroids, DNA, and other molecules of diagnostic value are found in saliva. It is easier to collect as compared to blood or urine. Unfortunately, saliva also contains large numbers of bacteria that can release enzymes, which can degrade proteins and nucleic acids. These degradative enzymes destroy or reduce saliva s diagnostic value. This innovation describes the formulation of a chemical preservative that prevents microbial growth and inactivates the degradative enzymes. This extends the time that saliva can be stored or transported without losing its diagnostic value. Multiple samples of saliva can be collected if needed without causing discomfort to the subject and it does not require any special facilities to handle after it is collected.

Thioaptamer Diagnostic System, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — AM Biotechnologies (AM) will develop a diagnostic system in response to SBIR Topic X10.01 Reusable Diagnostic Lab Technology that will simultaneously detect and...

Determinants of Human African Trypanosomiasis Elimination via Paratransgenesis.

Directory of Open Access Journals (Sweden)

Jennifer A Gilbert

2016-03-01

Full Text Available Human African trypanosomiasis (HAT, transmitted by tsetse flies, has historically infected hundreds of thousands of individuals annually in sub-Saharan Africa. Over the last decade, concerted control efforts have reduced reported cases to below 10,000 annually, bringing complete elimination within reach. A potential technology to eliminate HAT involves rendering the flies resistant to trypanosome infection. This approach can be achieved through the introduction of transgenic Sodalis symbiotic bacteria that have been modified to produce a trypanocide, and propagated via Wolbachia symbionts, which confer a reproductive advantage to the paratransgenic tsetse. However, the population dynamics of these symbionts within tsetse flies have not yet been evaluated. Specifically, the key factors that determine the effectiveness of paratransgenesis have yet to be quantified. To identify the impact of these determinants on T.b. gambiense and T.b. rhodesiense transmission, we developed a mathematical model of trypanosome transmission that incorporates tsetse and symbiont population dynamics. We found that fecundity and mortality penalties associated with Wolbachia or recombinant Sodalis colonization, probabilities of vertical transmission, and tsetse migration rates are fundamental to the feasibility of HAT elimination. For example, we determined that HAT elimination could be sustained over 25 years when Wolbachia colonization minimally impacted fecundity or mortality, and when the probability of recombinant Sodalis vertical transmission exceeded 99.9%. We also found that for a narrow range of recombinant Sodalis vertical transmission probability (99.9-90.6% for T.b. gambiense and 99.9-85.8% for T.b. rhodesiense, cumulative HAT incidence was reduced between 30% and 1% for T.b. gambiense and between 21% and 3% for T.b. rhodesiense, although elimination was not predicted. Our findings indicate that fitness and mortality penalties associated with paratransgenic

Deciphering RNA regulatory elements in trypanosomatids: one piece at a time or genome-wide?

Science.gov (United States)

Gazestani, Vahid H; Lu, Zhiquan; Salavati, Reza

2014-05-01

Morphological and metabolic changes in the life cycle of Trypanosoma brucei are accomplished by precise regulation of hundreds of genes. In the absence of transcriptional control, RNA-binding proteins (RBPs) shape the structure of gene regulatory maps in this organism, but our knowledge about their target RNAs, binding sites, and mechanisms of action is far from complete. Although recent technological advances have revolutionized the RBP-based approaches, the main framework for the RNA regulatory element (RRE)-based approaches has not changed over the last two decades in T. brucei. In this Opinion, after highlighting the current challenges in RRE inference, we explain some genome-wide solutions that can significantly boost our current understanding about gene regulatory networks in T. brucei. Copyright © 2014 Elsevier Ltd. All rights reserved.

21 CFR 874.1925 - Toynbee diagnostic tube.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Toynbee diagnostic tube. 874.1925 Section 874.1925...) MEDICAL DEVICES EAR, NOSE, AND THROAT DEVICES Diagnostic Devices § 874.1925 Toynbee diagnostic tube. (a) Identification. The toynbee diagnostic tube is a listening device intended to determine the degree of openness of...

Diagnostics for induction accelerators

International Nuclear Information System (INIS)

Fessenden, T.J.

1996-04-01

The induction accelerator was conceived by N. C. Christofilos and first realized as the Astron accelerator that operated at LLNL from the early 1960's to the end of 1975. This accelerator generated electron beams at energies near 6 MeV with typical currents of 600 Amperes in 400 ns pulses. The Advanced Test Accelerator (ATA) built at Livermore's Site 300 produced 10,000 Ampere beams with pulse widths of 70 ns at energies approaching 50 MeV. Several other electron and ion induction accelerators have been fabricated at LLNL and LBNL. This paper reviews the principal diagnostics developed through efforts by scientists at both laboratories for measuring the current, position, energy, and emittance of beams generated by these high current, short pulse accelerators. Many of these diagnostics are closely related to those developed for other accelerators. However, the very fast and intense current pulses often require special diagnostic techniques and considerations. The physics and design of the more unique diagnostics developed for electron induction accelerators are presented and discussed in detail

Polychromatic holographic plasma diagnostics

International Nuclear Information System (INIS)

Zhiglinskij, A.G.; Morozov, A.O.

1992-01-01

Review of holographic interferometry properties is performed and advantages of this method by plasma diagnostics are indicated. Main results obtained by the method of holographic interferometry in studies of various-type plasmas are considered. Special attention is paid to multiwave plasma diagnostics, the necessity of which is related as a rule to multicomponent composition of plasma. The eight laser and gas-discharge sources and holographic schemes, which make it possible to realize plasma polychromatic and holographic interferometry, are considered. The advantages of the method are demonstrated by examples of polychromatic holographic diagnostics of arc discharge and discharge in a hollow cathode. Review of theoretical works determining the applicability area of resonance polychromatic interferometry is carried out

Reversed field pinch diagnostics

International Nuclear Information System (INIS)

Weber, P.G.

1986-01-01

The Reversed Field Pinch (RFP) is a toroidal, axisymmetric magnetic confinement configuration characterized by a magnetic field configuration in which the toroidal magnetic field is of similar strength to the poloidal field, and is reversed at the edge compared to the center. The RFP routinely operates at high beta, and is a strong candidate for a compact fusion device. Relevant attributes of the configuration will be presented, together with an overview of present and planned experiments and their diagnostics. RFP diagnostics are in many ways similar to those of other magnetic confinement devices (such as tokamaks); these lectures will point out pertinent differences, and will present some diagnostics which provide special insights into unique attributes of the RFP

Summary Report on Synchronization, Diagnostics and Instrumentation

International Nuclear Information System (INIS)

Arne Freyberger

2005-01-01

The proceedings of Working Group 4 of the 2005 Energy Recovery Linac (ERL) workshop are summarized. Working Group 4 dealt with the challenging topic of beam diagnostics for ERL machines. Energy Recovery Linacs represent a challenge for beam diagnostics from several perspectives; invasive versus non-invasive diagnostics, longitudinal and transverse beam diagnostics, overall machine timing/synchronization and machine protection. Beam diagnostics for an ERL can benefit strongly from the experience at third generation light sources, recirculating linacs and presently operating ERLs. During the workshop there were presentations from all these communities, representing a large range operation experience in beam diagnostics. A brief summary Working Group 4 discussion is presented in this paper

Status of TMX upgrade diagnostics construction

International Nuclear Information System (INIS)

Hornady, R.S.; Davis, J.C.; Simonen, T.C.

1981-01-01

This report describes the status of the initial TMX Upgrade diagnostics and the state of development of additional diagnostics being prepared for later TMX Upgrade experiments. The initial diagnostic instrument set has been described in the TMX Upgrade Proposal. This set is required to get TMX Upgrade operational and to evaluate its initial performance. Additional diagnostic instruments are needed to then carry out the more detailed experiments outlined by the TMX Upgrade program milestones. The relation of these new measurements to the physics program is described in The TMX Upgrade Program Plan

Radiation shielding for TFTR DT diagnostics

International Nuclear Information System (INIS)

Ku, L.P.; Johnson, D.W.; Liew, S.L.

1994-01-01

The authors illustrate the designs of radiation shielding for the TFTR DT diagnostics using the ACX and TVTS systems as specific examples. The main emphasis here is on the radiation transport analyses carried out in support of the designs. Initial results from the DT operation indicate that the diagnostics have been functioning as anticipated and the shielding designs are satisfactory. The experience accumulated in the shielding design for the TFTR DT diagnostics should be useful and applicable to future devices, such as TPX and ITER, where many similar diagnostic systems are expected to be used

Whole Genome Sequencing Increases Molecular Diagnostic Yield Compared with Current Diagnostic Testing for Inherited Retinal Disease.

Science.gov (United States)

Ellingford, Jamie M; Barton, Stephanie; Bhaskar, Sanjeev; Williams, Simon G; Sergouniotis, Panagiotis I; O'Sullivan, James; Lamb, Janine A; Perveen, Rahat; Hall, Georgina; Newman, William G; Bishop, Paul N; Roberts, Stephen A; Leach, Rick; Tearle, Rick; Bayliss, Stuart; Ramsden, Simon C; Nemeth, Andrea H; Black, Graeme C M

2016-05-01

To compare the efficacy of whole genome sequencing (WGS) with targeted next-generation sequencing (NGS) in the diagnosis of inherited retinal disease (IRD). Case series. A total of 562 patients diagnosed with IRD. We performed a direct comparative analysis of current molecular diagnostics with WGS. We retrospectively reviewed the findings from a diagnostic NGS DNA test for 562 patients with IRD. A subset of 46 of 562 patients (encompassing potential clinical outcomes of diagnostic analysis) also underwent WGS, and we compared mutation detection rates and molecular diagnostic yields. In addition, we compared the sensitivity and specificity of the 2 techniques to identify known single nucleotide variants (SNVs) using 6 control samples with publically available genotype data. Diagnostic yield of genomic testing. Across known disease-causing genes, targeted NGS and WGS achieved similar levels of sensitivity and specificity for SNV detection. However, WGS also identified 14 clinically relevant genetic variants through WGS that had not been identified by NGS diagnostic testing for the 46 individuals with IRD. These variants included large deletions and variants in noncoding regions of the genome. Identification of these variants confirmed a molecular diagnosis of IRD for 11 of the 33 individuals referred for WGS who had not obtained a molecular diagnosis through targeted NGS testing. Weighted estimates, accounting for population structure, suggest that WGS methods could result in an overall 29% (95% confidence interval, 15-45) uplift in diagnostic yield. We show that WGS methods can detect disease-causing genetic variants missed by current NGS diagnostic methodologies for IRD and thereby demonstrate the clinical utility and additional value of WGS. Copyright © 2016 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Diagnostic Imaging Workshop

International Nuclear Information System (INIS)

Sociedad Argentina de Fisica Medica

2012-01-01

The American Association of Physicist in Medicine (AAPM), the International Organization for Medical Physics (IOMP) and the Argentina Society of Medical Physics (SAFIM) was organized the Diagnostic Imaging Workshop 2012, in the city of Buenos Aires, Argentina. This workshop was an oriented training and scientific exchange between professionals and technicians who work in medical physics, especially in the areas of diagnostic imaging, nuclear medicine and radiotherapy, with special emphasis on the use of multimodal imaging for radiation treatment, planning as well of quality assurance associates.

Calibration issues for neutron diagnostics

International Nuclear Information System (INIS)

Sadler, G.J.; Adams, J.M.; Barnes, C.W.

1997-10-01

In order for ITER to meet its operational and programmatic goals, it will be necessary to measure a wide range of plasma parameters. Some of the required parameters e.g., neutron yield, fusion power and power density, ion temperature profile in the core plasma, and characteristics of confined and escaping alpha particle populations are best measured by fusion product diagnostic techniques. To make these measurements, ITER will have dedicated diagnostic systems, including radial and vertical neutron cameras, neutron and gamma ray spectrometers, internal and external fission chambers, a neutron activation system, and diagnostics for confined and escaping alpha particles. Engineering integration of many of these systems is in progress, and other systems are under investigation. This paper summarizes the present state of design of fusion product diagnostic systems for ITER and discusses expected measurement capability

Fuel-motion diagnostics and cineradiography

International Nuclear Information System (INIS)

DeVolpi, A.

1982-09-01

Nuclear and non-nuclear applications of cineradiography are reviewed, with emphasis on diagnostic instrumentation for in-pile transient-reactor safety testing of nuclear fuel motion. The primary instrument for this purpose has been the fast-neutron hodoscope, which has achieved quantitative monitoring of time, location, mass, and velocity of fuel movement under the difficult conditions associated with transient-reactor experiments. Alternative diagnostic devices that have been developed have not matched the capabilities of the hodoscope. Other applications for the fuel-motion diagnostic apparatus are also evolving, including time-integrated radiography and direct time- and space-resolved fuel-pin power monitoring. Although only two reactors are now actively equipped with high-resolution fuel-motion diagnostic systems, studies and tests have been carried out in and for many other reactors

Recent diagnostic developments on LHD

International Nuclear Information System (INIS)

Sudo, S; Ozaki, T; Ashikawa, N; Emoto, M; Goto, M; Hamada, Y; Ida, K; Ido, T; Iguchi, H; Inagaki, S; Isobe, M; Kawahata, K; Khlopenkov, K; Kobuchi, T; Liang, Y; Masuzaki, S; Minami, T; Morita, S; Muto, S; Nagayama, Y; Nakanishi, H; Narihara, K; Nishizawa, A; Ohdachi, S; Osakabe, M; Peterson, B J; Sakakibara, S; Sasao, M; Sato, K; Shoji, M; Tamura, N; Tanaka, K; Toi, K; Tokuzawa, T; Watanabe, K; Watanabe, T; Yamada, I; Goncharov, P; Ejiri, A; Okajima, S; Mase, A; Tsuji-Iio, S; Akiyama, T; Lyon, J F; Vyacheslavov, L N; Sanin, A

2003-01-01

The recent diagnostic developments on the large helical device (LHD) are described briefly. LHD is the largest helical machine with all superconducting coils, and its purpose is to prove the ability of a helical system to confine a fusion-relevant plasma in steady state. According to the missions of LHD research, the diagnostic devices are categorized as follows: diagnostics for (i) high nτ E T plasmas and transport physics; (ii) magnetohydrodynamic stability; (iii) long pulse operation and divertor function; and (iv) energetic particles. These are briefly described focusing on the recent developments of the devices. Since the LHD experiment started in March 1998, five series of experimental campaigns have been carried out. The LHD diagnostics during these periods were operated successfully, and contributed to the analysis of the experimental results

In-service diagnostics of pumping facilities

International Nuclear Information System (INIS)

Jaros, I.

1987-01-01

The potential is discussed of technical diagnostics in increasing operating reliability of pumping facilities of conventional and nuclear power plants, and in rationalizing the system of their maintenance. Attention is focused on the selection of diagnostic parameters in which the so-called subjective expert methodology is applied, and on the diagnostic system design. At this stage, the construction of the respective facility and the analysis of the failure rate of its individual assemblies should be considered. The selection of diagnostic means directly depends on the selection of diagnostic parameters and is conditional on other factors, such as availability, cost, technical service, and operator's training. Briefly characterized are Czechoslovak standards assessing the mechanical condition of rotary machines from the measurement of the effective value of the rate of their oscillations. (Z.M.)

Copper laser diagnostics and kinetics support

International Nuclear Information System (INIS)

1981-12-01

In the effort MSNW participated with the LINL copper-Vapor Laser Program by providing a useful plasma diagnostic for interpretation of Copper-vapor laser kinetics. MSNW developed and delivered a pulsed interferometric diagnostic package to LLNL. Moreover MSNW provided personal services at the request and direction of LLL in the implementation of the diagnostic and interpretation of the data

Complications in diagnostic imaging. 2. ed.

International Nuclear Information System (INIS)

Ansell, G.; Wilkins, R.A.; Medical Research Council, Harrow

1987-01-01

Thirty-seven chapters review various complications which may arise for patients and staff in medical diagnostic imaging. Five of these chapters are indexed separately covering topics on the complications of using radiopharmaceuticals, safety considerations in magnetic resonance imaging, radiation hazards of diagnostic radiology and medico-legal problems involving diagnostic radiology in both the UK and the USA. (UK)

How to appraise a diagnostic test

Directory of Open Access Journals (Sweden)

Ramanitharan Manikandan

2011-01-01

Full Text Available Urologists frequently encounter problems in making a clinical diagnosis whose resolution requires the use of diagnostic tests. With an ever increasing choice of investigations being available, the urologist often has to decide which diagnostic test(s will best resolve the patient′s diagnostic problem. In this article, we aim to help the urologist understand how to critically appraise studies on diagnostic tests and make a rational choice. This article presents the guiding principles in scientifically assessing studies on diagnostic tests by proposing a clinical scenario. The authors describe a standardized protocol to assess the validity of the test and its relevance to the clinical problem that can help the urologist in decision making. The three important issues to be considered when evaluating the validity of the study are to identify how the study population was chosen, how the test was performed and whether there is a comparison to the gold standard test so as to confirm or refute the diagnosis. Then, the urologist would need to know the probability of the test in providing the correct diagnosis in an individual patient in order to decide about its utility in solving the diagnostic dilemma. By performing the steps described in this article, the urologist would be able to critically appraise diagnostic studies and draw meaningful conclusions about the investigations in terms of validity, results and its applicability to the patient′s problem. This would provide a scientific basis for using diagnostic tests for improving patient care.

Angiography - interventional diagnostic applications

International Nuclear Information System (INIS)

Schild, H.

1994-01-01

The angiography system is very different from the other systems used in diagnostic radiology. The invasivity of angiography requires special, high standards in theoretical and practical training and experience both of beginners and experienced personnel. This textbook fully meets the demand for in-depth and exhaustive information, as it presents: - The fundamentals and techniques of angiography, the vascular anatomy, and many hints and tips of great help in practice. - A comprehensive survey of diagnostic problems and examination approaches, including neuro-angiography, with 221 reproductions of original angiographs, and additional schematic representations. - A special chapter devoted to indication and relevant techniques for the major vascular interventional examinations. - A great number of tables explain at a glance standard examination techniques, indications and diagnostic criteria. (orig./CB) [de

Far infrared fusion plasma diagnostics

Energy Technology Data Exchange (ETDEWEB)

Luhmann, N.C. Jr.; Peebles, W.A.

1990-01-01

Over the last several years, reflectometry has grown in importance as a diagnostic for both steady-state density Profiles as well as for the investigation of density fluctuations and turbulence. As a diagnostic for density profile measurement, it is generally believed to be well understood in the tokamak environment. However, its use as a fluctuation diagnostic is hampered by a lack of quantitative experimental understanding of its wavenumber sensitivity and spatial resolution. Several researchers, have theoretically investigated these questions. However, prior to the UCLA laboratory investigation, no group has experimentally investigated these questions. Because of the reflectometer's importance to the world effort in understanding plasma turbulence and transport, UCLA has, over the last year, made its primary Task IIIA effort the resolution of these questions. UCLA has taken the lead in a quantitative experimental understanding of reflectometer data as applied to the measurement of density fluctuations. In addition to this, work has proceeded on the design, construction, and installation of a reflectometer system on UCLA's CCT tokamak. This effort will allow a comparison between the improved confinement regimes (H-mode) observed on both the DIII-D and CCT machines with the goal of achieving a physics understanding of the phenomena. Preliminary investigation of a new diagnostic technique to measure density profiles as a function of time has been initiated at UCLA. The technique promises to be a valuable addition to the range of available plasma diagnostics. Work on advanced holographic reflectometry technique as applied to fluctuation diagnostics has awaited a better understanding of the reflectometer signal itself as discussed above. Efforts to ensure the transfer of the diagnostic developments have continued with particular attention devoted to the preliminary design of a multichannel FIR interferometer for MST.

Novel uses of detonator diagnostics

Energy Technology Data Exchange (ETDEWEB)

Gibson, John R. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Wilde, Zakary Robert [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Tasker, Douglas George [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Francois, Elizabeth Green [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Nakamoto, Teagan Kanakanui Junichi [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Smith, Dalton Kay [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Trujillo, Christopher J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2017-09-15

A novel combination of diagnostics is being used to research the physics of detonator initiation. The explosive PETN (Pentaerythritol tetranitrate) commonly used in detonators, is also a piezo-electric material that, when sufficiently shocked, emits an electromagnetic field in the radio frequency (RF) range, along crystal fracture planes. In an effort to capture this RF signal, a new diagnostic was created. A copper foil, used as an RF antenna, was wrapped around a foam fixture encompassing a PETN pellet. Rogowski coils were used to obtain the change in current with respect to time (di/dt) the detonator circuit, in and polyvinylidene difluoride (PVDF) stress sensors were used to capture shockwave arrival time. The goal of these experiments is to use these diagnostics to study the reaction response of a PETN pellet of known particle size to shock loading with various diagnostics including an antenna to capture RF emissions. Our hypothesis is that RF feedback may signify the rate of deflagration to detonation transition (DDT) or lack thereof. The new diagnostics and methods will be used to determine the timing of start of current, bridge burst, detonator breakout timing and RF generated from detonation. These data will be compared to those of currently used diagnostics in order to validate the accuracy of these new methods. Future experiments will incorporate other methods of validation including dynamic radiography, optical initiation and use of magnetic field sensors.

Parent-Child Diagnostic Agreement on Anxiety Symptoms with a Structured Diagnostic Interview for Mental Disorders in Children.

Science.gov (United States)

Popp, Lukka; Neuschwander, Murielle; Mannstadt, Sandra; In-Albon, Tina; Schneider, Silvia

2017-01-01

Objective: In clinical structured diagnostic interviews, diagnoses based on parent and child reports have low to moderate agreement. The aims of the present study are (1) to examine diagnostic agreement on anxiety disorders between parents and children on the levels of current and lifetime diagnostic category and diagnoses focusing in particular on diagnostic criteria and (2) to identify parent- and child-related predictors for diagnostic agreement. Method: The sample consisted of 166 parent-child dyads interviewed with the Structured Diagnostic Interview for Mental Disorders in Children (Kinder-DIPS, Schneider et al., 2009). The children (51.8% girls) were between the ages of 7 and 18 years ( M = 10.94; SD = 2.22). Results: Overall, parent-child agreement on the diagnostic category of anxiety disorder ( k = 0.21; k = 0.22) and the specific anxiety diagnoses (base rate > 10%) of social phobia, specific phobia and separation anxiety disorder ( k = 0.24-0.52; k = 0.19-0.43) and corresponding diagnostic criteria ( k = 0.22-0.67; k = 0.24-0.41) were low to moderate with the highest agreement on separation anxiety disorder ( k > 0.43). Lower maternal depression, and higher social support reported by mother and father were associated with higher parent-child agreement. Maternal depression was indicated as the strongest predictor. Parental sense of competence, parental anxiety, the amount of parent-child interaction and the child's age and gender had no predictive value. Conclusions: Parent-child agreement can be expected to be higher on the level of anxiety criteria compared to specific anxiety diagnoses and diagnostic anxiety category. Psychological strains in the family-especially maternal depression and low social support-lower the parent-child agreement on anxiety symptoms. Child- and relation-related variables (age, gender, amount of time parent(s) and children interact) play no role in the prediction of low parent-child agreement.

Diagnostic challenges of childhood asthma.

Science.gov (United States)

Bakirtas, Arzu

2017-01-01

Diagnosis of asthma in childhood is challenging. Both underdiagnosis and overdiagnosis of asthma are important issues. The present review gives information about challenging factors for an accurate diagnosis of childhood asthma. Although underdiagnosis of asthma in childhood has always been the most important diagnostic problem, overdiagnosis of asthma has also been increasingly recognized. This is probably due to diagnosis of asthma based on symptoms and signs alone. Demonstration of variable airflow obstruction by lung function tests is the most common asthma diagnostic tests used in practice and is therefore strongly recommended in children who can cooperate. Recently, an asthma guideline combining the clinical and economic evidences with sensitivity and specificity of diagnostic procedures was developed to improve accuracy of diagnosis and to avoid overdiagnosis. This guideline provided an algorithmic clinical and cost-effective approach and included fractional exhaled nitric oxide measurement as one of the diagnostic tests in addition to lung function. Diagnosis of asthma in children should be made by combining relevant history with at least two confirmatory diagnostic tests whenever possible. Diagnosis based on short-period treatment trials should be limited to young children who are unable to cooperate with these tests.

The current and future state of companion diagnostics

Science.gov (United States)

Agarwal, Amit; Ressler, Dan; Snyder, Glenn

2015-01-01

Companion diagnostics are an indispensable part of personalized medicine and will likely continue to rapidly increase in number and application to disease areas. The first companion diagnostics were launched in the 1980s and in the face of significant initial skepticism from drug developers as to whether segmenting a drug’s market through a diagnostic was advisable. The commercial success of drugs such as Herceptin® (trastuzumab) and Gleevec® (imatinib), which both require testing with companion diagnostics before they can be prescribed, has moved the entire companion diagnostic field forward. From an initial start of a handful of oncology drugs with corresponding diagnostics, the field has expanded to include multiple therapeutic areas, and the number of combinations has grown by 12-fold. Based on drugs in clinical trials, the rapid growth will likely continue for the foreseeable future. This expansion of companion diagnostics will also have a global component as markets in Europe will evolve in a similar but not identical pattern as the US. One of the greatest challenges to future growth in companion diagnostics is aligning the incentives of all stakeholders. A major driver of growth will continue to be the economic incentives for drug developers to pair their products with diagnostics. However, diagnostic companies are caught between the conflicting demands of two major stakeholders, pharmaceutical companies on one hand and payers/providers on the other. Regulators are also becoming more demanding in aligning development time lines between drugs and diagnostics. In order to survive and prosper, diagnostic companies will need to think more broadly about companion diagnostics than the historical match between a specific drug and a single diagnostic. They will also have to continue the process of consolidation and global expansion that the industry has already begun. Despite these potential obstacles, companion diagnostics have become one of the hottest areas

Small business development for molecular diagnostics.

Science.gov (United States)

Anagostou, Anthanasia; Liotta, Lance A

2012-01-01

Molecular profiling, which is the application of molecular diagnostics technology to tissue and blood -specimens, is an integral element in the new era of molecular medicine and individualized therapy. Molecular diagnostics is a fertile ground for small business development because it can generate products that meet immediate demands in the health-care sector: (a) Detection of disease risk, or early-stage disease, with a higher specificity and sensitivity compared to previous testing methods, and (b) "Companion diagnostics" for stratifying patients to receive a treatment choice optimized to their individual disease. This chapter reviews the promise and challenges of business development in this field. Guidelines are provided for the creation of a business model and the generation of a marketing plan around a candidate molecular diagnostic product. Steps to commercialization are outlined using existing molecular diagnostics companies as learning examples.

Diagnostics for the National Compact Stellarator Experiment

International Nuclear Information System (INIS)

Stratton, B.C.; Johnson, D.; Feder, R.; Fredrickson, E.; Neilson, H.; Takahashi, H.; Zarnstorf, M.; Cole, M.; Goranson, P.; Lazarus, E.; Nelson, B.

2003-01-01

The status of planning of the National Compact Stellarator Experiment (NCSX) diagnostics is presented, with the emphasis on resolution of diagnostics access issues and on diagnostics required for the early phases of operation

Diagnostics for the ATA beam propagation experiments

International Nuclear Information System (INIS)

Fessenden, T.J.; Atchison, W.L.; Barletta, W.A.

1981-11-01

This report contains a discussion of the diagnostics required for the beam propagation experiment to be done with the ATA accelerator. Included are a list of the diagnostics needed; a description of the ATA experimental environment; the status of beam diagnostics available at Livermore including recent developments, and a prioritized list of accelerator and propagation diagnostics under consideration or in various stages of development

Mammary carcinoma diagnostics and therapy

International Nuclear Information System (INIS)

Fischer, Uwe; Baum, Friedemann

2014-01-01

The book on mammary carcinoma diagnostics and therapy covers the following issues: development, anatomy and physiology of the mammary glands, pathology of benign and malign mammary gland changes, non-imaging diagnostics; mammography; ultrasonic mammography; magnetic resonance tomography of the mammary glands; imaging diagnostics findings; mammary interventions; examination concepts; operative therapy of the mammary carcinoma; chemotherapy of the mammary carcinoma; radio-oncological therapy of the mammary carcinoma; logistics in a medical center for mammary gland diseases; logistics in an interdisciplinary center for mammary diseases; dialogue conduction and psycho-social attendance.

Melarsoprol sensitivity profile of Trypanosoma brucei gambiense isolates from cured and relapsed sleeping sickness patients from the Democratic Republic of the Congo.

Directory of Open Access Journals (Sweden)

Patient Pyana Pati

2014-10-01

Full Text Available Sleeping sickness caused by Trypanosoma brucei (T.b. gambiense constitutes a serious health problem in sub-Sahara Africa. In some foci, alarmingly high relapse rates were observed in patients treated with melarsoprol, which used to be the first line treatment for patients in the neurological disease stage. Particularly problematic was the situation in Mbuji-Mayi, East Kasai Province in the Democratic Republic of the Congo with a 57% relapse rate compared to a 5% relapse rate in Masi-Manimba, Bandundu Province. The present study aimed at investigating the mechanisms underlying the high relapse rate in Mbuji-Mayi using an extended collection of recently isolated T.b. gambiense strains from Mbuji-Mayi and from Masi-Manimba.Forty five T.b. gambiense strains were used. Forty one were isolated from patients that were cured or relapsed after melarsoprol treatment in Mbuji-Mayi. In vivo drug sensitivity tests provide evidence of reduced melarsoprol sensitivity in these strains. This reduced melarsoprol sensitivity was not attributable to mutations in TbAT1. However, in all these strains, irrespective of the patient treatment outcome, the two aquaglyceroporin (AQP 2 and 3 genes are replaced by chimeric AQP2/3 genes that may be associated with resistance to pentamidine and melarsoprol. The 4 T.b. gambiense strains isolated in Masi-Manimba contain both wild-type AQP2 and a different chimeric AQP2/3. These findings suggest that the reduced in vivo melarsoprol sensitivity of the Mbuji-Mayi strains and the high relapse rates in that sleeping sickness focus are caused by mutations in the AQP2/AQP3 locus and not by mutations in TbAT1.We conclude that mutations in the TbAQP2/3 locus of the local T.b. gambiense strains may explain the high melarsoprol relapse rates in the Mbuji-Mayi focus but other factors must also be involved in the treatment outcome of individual patients.

Diagnostics for induction accelerators

International Nuclear Information System (INIS)

Fessenden, T.J.

1997-01-01

The induction accelerator was conceived by N. C. Christofilos and first realized as the Astron accelerator that operated at Lawrence Livermore National Laboratory (LLNL) from the early 1960s to the end of 1975. This accelerator generated electron beams at energies near 6 MeV with typical currents of 600 Amperes in 400-ns pulses. The Advanced Test Accelerator (ATA) built at Livermore close-quote s Site 300 produced 10,000-Ampere beams with pulse widths of 70 ns at energies approaching 50 MeV. Several other electron and ion induction accelerators have been fabricated at LLNL and Lawrence Berkeley National Laboratory (LBNL). This paper reviews the principal diagnostics developed through efforts by scientists at both laboratories for measuring the current, position, energy, and emittance of beams generated by these high-current, short-pulse accelerators. Many of these diagnostics are closely related to those developed for other accelerators. However, the very fast and intense current pulses often require special diagnostic techniques and considerations. The physics and design of the more unique diagnostics developed for electron induction accelerators are presented and discussed in detail. copyright 1997 American Institute of Physics

X-ray diagnostics - benefits and risks

International Nuclear Information System (INIS)

Bartholomaeus, Melanie

2016-01-01

The brochure on benefits and risks of X-ray diagnostics discusses the following issues: X radiation - a pioneering discovery and medical sensation, fundamentals of X radiation, frequency of X-ray examinations in Germany in relation to CT imaging, radiation doses resulting from X-ray diagnostics, benefits of X-ray diagnostics - indication and examples, risks - measures for radiation exposure reductions, avoidance of unnecessary examinations.

Psychometric perspectives on diagnostic systems

NARCIS (Netherlands)

Borsboom, D.

2008-01-01

The author identifies four conceptualizations of the relation between symptoms and disorders as utilized in diagnostic systems such as the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV; American Psychiatric Association, 1994): A constructivist perspective, which holds

Diagnostic methods for insect sting allergy.

Science.gov (United States)

Hamilton, Robert G

2004-08-01

This review overviews advances from mid-2002 to the present in the validation and performance methods used in the diagnosis of Hymenoptera venom-induced immediate-type hypersensitivity. The general diagnostic algorithm for insect sting allergy is initially discussed with an examination of the AAAAI's 2003 revised practice parameter guidelines. Changes as a result of a greater recognition of skin test negative systemic reactors include repeat analysis of all testing and acceptance of serology as a complementary diagnostic test to the skin test. Original data examining concordance of venom-specific IgE results produced by the second-generation Pharmacia CAP System with the Johns Hopkins University radioallergosorbent test are presented. Diagnostic performance of honeybee venom-specific IgE assays used in clinical laboratories in North America is discussed using data from the Diagnostic Allergy Proficiency Survey conducted by the College of American Pathologists. Validity of venom-specific IgE antibody in postmortem blood specimens is demonstrated. The utility of alternative in-vivo (provocation) and in-vitro (basophil-based) diagnostic testing methods is critiqued. This overview supports the following conclusions. Improved practice parameter guidelines include serology and skin test as complementary in supporting a positive clinical history during the diagnostic process. Data are provided which support the analytical performance of commercially available venom-specific IgE antibody serology-based assays. Intentional sting challenge in-vivo provocation, in-vitro basophil flow cytometry (CD63, CD203c) based assays, and in-vitro basophil histamine and sulfidoleukotriene release assays have their utility in the study of difficult diagnostic cases, but their use will remain as supplementary, secondary diagnostic tests.

Diagnostic nerve ultrasonography; Diagnostische Nervensonographie

Energy Technology Data Exchange (ETDEWEB)

Baeumer, T. [Universitaet zu Luebeck CBBM, Haus 66, Institut fuer Neurogenetik, Luebeck (Germany); Grimm, A. [Universitaetsklinikum Tuebingen, Klinik und Poliklinik fuer Neurologie, Tuebingen (Germany); Schelle, T. [Staedtisches Klinikum Dessau, Neurologische Klinik, Dessau (Germany)

2017-03-15

For the diagnostics of nerve lesions an imaging method is necessary to visualize peripheral nerves and their surrounding structures for an etiological classification. Clinical neurological and electrophysiological investigations provide functional information about nerve lesions. The information provided by a standard magnetic resonance imaging (MRI) examination is inadequate for peripheral nerve diagnostics; however, MRI neurography is suitable but on the other hand a resource and time-consuming method. Using ultrasonography for peripheral nerve diagnostics. With ultrasonography reliable diagnostics of entrapment neuropathies and traumatic nerve lesions are possible. The use of ultrasonography for neuropathies shows that a differentiation between different forms is possible. Nerve ultrasonography is an established diagnostic tool. In addition to the clinical examination and clinical electrophysiology, structural information can be obtained, which results in a clear improvement in the diagnostics. Ultrasonography has become an integral part of the diagnostic work-up of peripheral nerve lesions in neurophysiological departments. Nerve ultrasonography is recommended for the diagnostic work-up of peripheral nerve lesions in addition to clinical and electrophysiological investigations. It should be used in the clinical work-up of entrapment neuropathies, traumatic nerve lesions and spacy-occupying lesions of nerves. (orig.) [German] Fuer die Diagnostik von Nervenlaesionen ist ein bildgebendes Verfahren zur Darstellung des peripheren Nervs und seiner ihn umgebenden Strukturen fuer eine aetiologische Einordnung erforderlich. Mit der klinisch-neurologischen Untersuchung und Elektrophysiologie ist eine funktionelle Aussage ueber die Nervenlaesion moeglich. In der Standard-MRT-Untersuchung wird der periphere Nerv nur unzureichend gut dargestellt. Die MRT-Neurographie ist ein sehr gutes, aber auch zeit- und ressourcenintensives Verfahren. Nutzung des Ultraschalls fuer die

Diagnostic radiography: A study in distancing

International Nuclear Information System (INIS)

Reeves, Pauline J.; Decker, Sola

2012-01-01

Aims: This article aims to explore the ways in which diagnostic radiographers use distancing as a tool for emotional management in radiography practice. Methods: This review utilises data from oral history interviews undertaken as part of a larger study documenting the oral history of the diagnostic radiography profession in the United Kingdom as recounted by 24 participants. Results: The results are presented as illustrative of various aspects of the role of the diagnostic radiographer including the initial choice of diagnostic radiography as a profession, the endemic use of particular terminology, the nature of the encounter in diagnostic radiography (including that of sectional imaging) and whether the role is really patient-centred. Conclusions: The article concludes by suggesting that distancing from the patient is mediated by the need for physical touch in order to position the patient for radiography and also makes the suggestion that those opting for diagnostic radiography as a career may do so because they want a profession which is more distanced from the patient and that, even where this is not the case initially, individuals are socialised into adopting the ‘feeling rules’ of the profession. The article concludes by outlining potential areas for further research.

Structure induction in diagnostic causal reasoning.

Science.gov (United States)

Meder, Björn; Mayrhofer, Ralf; Waldmann, Michael R

2014-07-01

Our research examines the normative and descriptive adequacy of alternative computational models of diagnostic reasoning from single effects to single causes. Many theories of diagnostic reasoning are based on the normative assumption that inferences from an effect to its cause should reflect solely the empirically observed conditional probability of cause given effect. We argue against this assumption, as it neglects alternative causal structures that may have generated the sample data. Our structure induction model of diagnostic reasoning takes into account the uncertainty regarding the underlying causal structure. A key prediction of the model is that diagnostic judgments should not only reflect the empirical probability of cause given effect but should also depend on the reasoner's beliefs about the existence and strength of the link between cause and effect. We confirmed this prediction in 2 studies and showed that our theory better accounts for human judgments than alternative theories of diagnostic reasoning. Overall, our findings support the view that in diagnostic reasoning people go "beyond the information given" and use the available data to make inferences on the (unobserved) causal rather than on the (observed) data level. (c) 2014 APA, all rights reserved.

Particle diagnostics for magnetic fusion experiments

International Nuclear Information System (INIS)

Post, D.E.

1983-01-01

This chapter summarizes the subset of diagnostics that relies primarily on the use of particles, and attempts to show how atomic and molecular data play a role in these diagnostics. Discusses passive charge-exchange ion temperature measurements; hydrogen beams for density, ion temperature, q and ZEFF measurements; impurity diagnostics using charge-exchange recombination; plasma electric and magnetic measurements using beams heavier than hydrogen; and alpha particle diagnostics. Points out that as fusion experiments become larger and hotter, most traditional particle diagnostics become difficult because large plasmas are difficult for neutral atoms to penetrate and the gyro-orbits of charged particles need to be larger than typically obtained with present beams to be comparable with the plasma size. Concludes that not only does the current profile affect the plasma stability, but there is a growing opinion that any serious fusion reactor will have to be steady state

Diagnostic criteria for headache attributed to temporomandibular disorders

DEFF Research Database (Denmark)

Schiffman, Eric; Ohrbach, Richard; List, Thomas

2012-01-01

We assessed and compared the diagnostic accuracy of two sets of diagnostic criteria for headache secondary to temporomandibular disorders (TMD).......We assessed and compared the diagnostic accuracy of two sets of diagnostic criteria for headache secondary to temporomandibular disorders (TMD)....

Ambient diagnostics

CERN Document Server

Cai, Yang

2014-01-01

Part I. FundamentalsIntroductionWhat is Ambient Diagnostics?Diagnostic ModelsMultimedia IntelligenceCrowd SourcingSoft SensorsScience of SimplicityPersonal DiagnosesBasic AlgorithmsBasic ToolsSummaryProblemsTransformationEarly Discoveries of Heartbeat PatternsTransforms, Features, and AttributesSequential FeaturesSpatiotemporal FeaturesShape FeaturesImagery FeaturesFrequency Domain FeaturesMulti-Resolution FeaturesSummaryProblemsPattern RecognitionSimilarities and DistancesClustering MethodsClassification MethodsClassifier Accuracy MeasuresSummaryProblemsPart II. Multimedia IntelligenceSound RecognitionMicrophone AppsModern Acoustic Transducers (Microphones)Frequency Response CharacteristicsDigital Audio File FormatsHeart Sound SensingLung Sound SensingSnore MeterSpectrogram (STFT)Ambient Sound AnalysisSound RecognitionRecognizing Asthma SoundPeak ShiftFeature CompressionRegroupingNoise IssuesFuture ApplicationsSummaryProblemsColor SensorsColor SensingHuman Color VisionColor SensorsColor Matching ExperimentsC...

Diagnostic reliability of MMPI-2 computer-based test interpretations.

Science.gov (United States)

Pant, Hina; McCabe, Brian J; Deskovitz, Mark A; Weed, Nathan C; Williams, John E

2014-09-01

Reflecting the common use of the MMPI-2 to provide diagnostic considerations, computer-based test interpretations (CBTIs) also typically offer diagnostic suggestions. However, these diagnostic suggestions can sometimes be shown to vary widely across different CBTI programs even for identical MMPI-2 profiles. The present study evaluated the diagnostic reliability of 6 commercially available CBTIs using a 20-item Q-sort task developed for this study. Four raters each sorted diagnostic classifications based on these 6 CBTI reports for 20 MMPI-2 profiles. Two questions were addressed. First, do users of CBTIs understand the diagnostic information contained within the reports similarly? Overall, diagnostic sorts of the CBTIs showed moderate inter-interpreter diagnostic reliability (mean r = .56), with sorts for the 1/2/3 profile showing the highest inter-interpreter diagnostic reliability (mean r = .67). Second, do different CBTIs programs vary with respect to diagnostic suggestions? It was found that diagnostic sorts of the CBTIs had a mean inter-CBTI diagnostic reliability of r = .56, indicating moderate but not strong agreement across CBTIs in terms of diagnostic suggestions. The strongest inter-CBTI diagnostic agreement was found for sorts of the 1/2/3 profile CBTIs (mean r = .71). Limitations and future directions are discussed. PsycINFO Database Record (c) 2014 APA, all rights reserved.

Summary from working group on noninterceptive diagnostics

International Nuclear Information System (INIS)

Chamberlin, D.D.

1985-01-01

The working group for noninterceptive diagnostics spent much of its time comparing diagnostic techniques from different fields and their possible application to high-power injectors. The group included backgrounds from electron beam diagnostics, fusion power diagnostics, cw ion source and transport design, and ion beam of diagnostics. The probability of success for adapting techniques from these different areas is quite difficult to judge, short of a detailed examination of each application. Unexpected flaws or unforeseen noise sources can eliminate an idea that would otherwise appear promising. The report presents several ideas that were discussed, with an indication of those ideas most likely to succeed if implemented

Calibration issues for neutron diagnostics

International Nuclear Information System (INIS)

Sadler, G.J.; Adams, J.M.; Barnes, C.W.

1997-01-01

The performance of diagnostic systems are limited by their weakest constituents, including their calibration issues. Neutron diagnostics are notorious for problems encountered while determining their absolute calibrations, due mainly to the nature of the neutron transport problem. In order to facilitate the determination of an accurate and precise calibration, the diagnostic design should be such as to minimize the scattered neutron flux. ITER will use a comprehensive set of neutron diagnostics--comprising radial and vertical neutron cameras, neutron spectrometers, a neutron activation system and internal and external fission chambers--to provide accurate measurements of fusion power and power densities as a function of time. The calibration of such an important diagnostic system merits careful consideration. Some thoughts have already been given to this subject during the conceptual design phase in relation to the time-integrated neutron activation and time-dependent neutron yield monitors. However, no overall calibration strategy has been worked out so far. This paper represents a first attempt to address this vital issue. Experience gained from present large tokamaks (JET, TFTR and JT60U) and proposals for ITER are reviewed. The need to use a 14-MeV neutron generator as opposed to radioactive sources for in-situ calibration of D-T diagnostics will be stressed. It is clear that the overall absolute determination of fusion power will have to rely on a combination of nuclear measuring techniques, for which the provision of accurate and independent calibrations will constitute an ongoing process as ITER moves from one phase of operation to the next

Imaging systems for medical diagnostics

International Nuclear Information System (INIS)

Krestel, E.

1990-01-01

This book provides physicians and clinical physicists with detailed information on today's imaging modalities and assists them in selecting the optimal system for each clinical application. Physicists, engineers and computer specialists engaged in research and development and sales departments will also find this book to be of considerable use. It may also be employed at universities, training centers and in technical seminars. The physiological and physical fundamentals are explained in part 1. The technical solutions contained in part 2 illustrate the numerous possibilities available in X-ray diagnostics, computed tomography, nuclear medical diagnostics, magnetic resonance imaging, sonography and biomagnetic diagnostics. (orig.)

[Diagnostic laparoscopy in acute abdomen].

Science.gov (United States)

Keller, R; Kleemann, M; Hildebrand, P; Roblick, U J; Bruch, H-P

2006-11-01

Acute abdomen is not a disease in itself but a description of a complex of symptoms combined with severe abdominal pain developed within a time frame of less than 24 h. All strategies for the management of acute abdomen underline the need for an interdisciplinary approach to diagnosis and therapy. This requires focused and intelligent use of efficient diagnostic procedures. Diagnostic laparoscopy may be a key to solving the diagnostic dilemma of unspecific acute abdomen. Furthermore, it allows not only direct inspection of the abdominal cavity but also surgical intervention, if needed. In particular the rate of negative laparotomies can be reduced.

Molecular diagnostics of periodontitis

OpenAIRE

Izabela Korona-Głowniak; Radosław Siwiec; Marcin Berger; Anna Malm; Jolanta Szymańska

2017-01-01

The microorganisms that form dental plaque are the main cause of periodontitis. Their identification and the understanding of the complex relationships and interactions that involve these microorganisms, environmental factors and the host’s health status enable improvement in diagnostics and targeted therapy in patients with periodontitis. To this end, molecular diagnostics techniques (both techniques based on the polymerase chain reaction and those involving nucleic acid analysis via hybridi...

Diagnostics in Japan's microgravity experiments

Science.gov (United States)

Kadota, Toshikazu

1995-01-01

The achievement of the combustion research under microgravity depends substantially on the availability of diagnostic systems. The non-intrusive diagnostic systems are potentially applicable for providing the accurate, realistic and detailed information on momentum, mass and energy transport, complex gas phase chemistry, and phase change in the combustion field under microgravity. The non-intrusive nature of optical instruments is essential to the measurement of combustion process under microgravity which is very nervous to any perturbation. However, the implementation of the non-intrusive combustion diagnostic systems under microgravity is accompanied by several constraints. Usually, a very limited space is only available for constructing a highly sophisticated system which is so sensitive that it is easily affected by the magnitude of the gravitational force, vibration and heterogeneous field of temperature and density of the environments. The system should be properly adjusted prior to the experiment. Generally, it is quite difficult to tune the instruments during measurements. The programmed sequence of operation should also be provided. Extensive effort has been toward the development of non-intrusive diagnostic systems available for the combustion experiments under microgravity. This paper aims to describe the current art and the future strategy on the non-intrusive diagnostic systems potentially applicable to the combustion experiments under microgravity in Japan.

International Workshop on Diagnostics for ITER

CERN Document Server

Gorini, Giuseppe; Sindoni, Elio

1996-01-01

This book of proceedings collects the papers presented at the Workshop on Diagnostics for ITER, held at Villa Monastero, Varenna (Italy), from August 28 to September 1, 1995. The Workshop was organised by the International School of Plasma Physics "Piero Caldirola. " Established in 1971, the ISPP has organised over fifty advanced courses and workshops on topics mainly related to plasma physics. In particular, courses and workshops on plasma diagnostics (previously held in 1975, 1978, 1982, 1986, and 1991) can be considered milestones in the history of this institution. Looking back at the proceedings of the previous meetings in Varenna, one can appreciate the rapid progress in the field of plasma diagnostics over the past 20 years. The 1995 workshop was co-organised by the Istituto di Fisica del Plasma of the National Research Council (CNR). In contrast to previous Varenna meetings on diagnostics, which have covered diagnostics in present-day tokamaks and which have had a substantial tutorial component, the 1...

Exposure from diagnostic nuclear medicine procedures

International Nuclear Information System (INIS)

Iacob, O.; Diaconescu, C.; Isac, R.

2002-01-01

According to our last national study on population exposures from natural and artificial sources of ionizing radiation, 16% of overall annual collective effective dose represent the contribution of diagnostic medical exposures. Of this value, 92% is due to diagnostic X-ray examinations and only 8% arise from diagnostic nuclear medicine procedures. This small contribution to collective dose is mainly the result of their lower frequency compared to that of the X-ray examinations, doses delivered to patients being, on average, ten times higher. The purpose of this review was to reassess the population exposure from in vivo diagnostic nuclear medicine procedures and to evaluate the temporal trends of diagnostic usage of radiopharmaceuticals in Romania. The current survey is the third one conducted in the last decade. As in the previous ones (1990 and 1995), the contribution of the Radiation Hygiene Laboratories Network of the Ministry of Health and Family in collecting data from nuclear medicine departments in hospitals was very important

Parent-Child Diagnostic Agreement on Anxiety Symptoms with a Structured Diagnostic Interview for Mental Disorders in Children

Science.gov (United States)

Popp, Lukka; Neuschwander, Murielle; Mannstadt, Sandra; In-Albon, Tina; Schneider, Silvia

2017-01-01

Objective: In clinical structured diagnostic interviews, diagnoses based on parent and child reports have low to moderate agreement. The aims of the present study are (1) to examine diagnostic agreement on anxiety disorders between parents and children on the levels of current and lifetime diagnostic category and diagnoses focusing in particular on diagnostic criteria and (2) to identify parent- and child-related predictors for diagnostic agreement. Method: The sample consisted of 166 parent-child dyads interviewed with the Structured Diagnostic Interview for Mental Disorders in Children (Kinder-DIPS, Schneider et al., 2009). The children (51.8% girls) were between the ages of 7 and 18 years (M = 10.94; SD = 2.22). Results: Overall, parent-child agreement on the diagnostic category of anxiety disorder (k = 0.21; k = 0.22) and the specific anxiety diagnoses (base rate > 10%) of social phobia, specific phobia and separation anxiety disorder (k = 0.24–0.52; k = 0.19–0.43) and corresponding diagnostic criteria (k = 0.22–0.67; k = 0.24–0.41) were low to moderate with the highest agreement on separation anxiety disorder (k > 0.43). Lower maternal depression, and higher social support reported by mother and father were associated with higher parent-child agreement. Maternal depression was indicated as the strongest predictor. Parental sense of competence, parental anxiety, the amount of parent-child interaction and the child's age and gender had no predictive value. Conclusions: Parent-child agreement can be expected to be higher on the level of anxiety criteria compared to specific anxiety diagnoses and diagnostic anxiety category. Psychological strains in the family—especially maternal depression and low social support—lower the parent-child agreement on anxiety symptoms. Child- and relation-related variables (age, gender, amount of time parent(s) and children interact) play no role in the prediction of low parent-child agreement. PMID:28396644

Proposed Diagnostic Criteria for the DSM-5 of Nonsuicidal Self-Injury in Female Adolescents: Diagnostic and Clinical Correlates

Directory of Open Access Journals (Sweden)

Tina In-Albon

2013-01-01

Full Text Available Nonsuicidal self-injury (NSSI is included as conditions for further study in the DSM-5. Therefore, it is necessary to investigate the proposed diagnostic criteria and the diagnostic and clinical correlates for the validity of a diagnostic entity. The authors investigated the characteristics of NSSI disorder and the proposed diagnostic criteria. A sample of 73 female inpatient adolescents and 37 nonclinical adolescents (aged 13 to 19 years was recruited. Patients were classified into 4 groups (adolescents with NSSI disorder, adolescents with NSSI without impairment/distress, clinical controls without NSSI, and nonclinical controls. Adolescents were compared on self-reported psychopathology and diagnostic cooccurrences. Results indicate that adolescents with NSSI disorder have a higher level of impairment than adolescents with other mental disorders without NSSI. Most common comorbid diagnoses were major depression, social phobia, and PTSD. There was some overlap of adolescents with NSSI disorder and suicidal behaviour and borderline personality disorder, but there were also important differences. Results further suggest that the proposed DSM-5 diagnostic criteria for NSSI are useful and necessary. In conclusion, NSSI is a highly impairing disorder characterized by high comorbidity with various disorders, providing further evidence that NSSI should be a distinct diagnostic entity.

TECHNICAL DIAGNOSTICS AT RUP “BMZ”

Directory of Open Access Journals (Sweden)

A. A. Kuzembajev

2004-01-01

Full Text Available The review of technical diagnostics and crack detection at RUP “BMZ” is given in the article and there are reflected the functions and tasks of the Laboratory of Technical Diagnostics and Crack detection (LTDandC. The examples of determination of the equipment failure by methods of vibration diagnostics, applied in LTDandC, are given and the efficiency of using of the system of technical servicing of the equipment according to “state” is shown. The idea of transfer from the repairs system “according to schedule” to repairs “according to state” using new information technologies such as vibrating monitoring and vibrating diagnostics is briefly reflected in the article.

Multi-method automated diagnostics of rotating machines

Science.gov (United States)

Kostyukov, A. V.; Boychenko, S. N.; Shchelkanov, A. V.; Burda, E. A.

2017-08-01

The automated machinery diagnostics and monitoring systems utilized within the petrochemical plants are an integral part of the measures taken to ensure safety and, as a consequence, the efficiency of these industrial facilities. Such systems are often limited in their functionality due to the specifics of the diagnostic techniques adopted. As the diagnostic techniques applied in each system are limited, and machinery defects can have different physical nature, it becomes necessary to combine several diagnostics and monitoring systems to control various machinery components. Such an approach is inconvenient, since it requires additional measures to bring the diagnostic results in a single view of the technical condition of production assets. In this case, we mean by a production facility a bonded complex of a process unit, a drive, a power source and lines. A failure of any of these components will cause an outage of the production asset, which is unacceptable. The purpose of the study is to test a combined use of vibration diagnostics and partial discharge techniques within the diagnostic systems of enterprises for automated control of the technical condition of rotating machinery during maintenance and at production facilities. The described solutions allow you to control the condition of mechanical and electrical components of rotating machines. It is shown that the functionality of the diagnostics systems can be expanded with minimal changes in technological chains of repair and operation of rotating machinery. Automation of such systems reduces the influence of the human factor on the quality of repair and diagnostics of the machinery.

42 CFR 493.833 - Condition: Diagnostic immunology.

Science.gov (United States)

2010-10-01

... 42 Public Health 5 2010-10-01 2010-10-01 false Condition: Diagnostic immunology. 493.833 Section..., Or Any Combination of These Tests § 493.833 Condition: Diagnostic immunology. The specialty of diagnostic immunology includes for purposes of proficiency testing the subspecialties of syphilis serology...

Measures to Improve Diagnostic Safety in Clinical Practice.

Science.gov (United States)

Singh, Hardeep; Graber, Mark L; Hofer, Timothy P

2016-10-20

Timely and accurate diagnosis is foundational to good clinical practice and an essential first step to achieving optimal patient outcomes. However, a recent Institute of Medicine report concluded that most of us will experience at least one diagnostic error in our lifetime. The report argues for efforts to improve the reliability of the diagnostic process through better measurement of diagnostic performance. The diagnostic process is a dynamic team-based activity that involves uncertainty, plays out over time, and requires effective communication and collaboration among multiple clinicians, diagnostic services, and the patient. Thus, it poses special challenges for measurement. In this paper, we discuss how the need to develop measures to improve diagnostic performance could move forward at a time when the scientific foundation needed to inform measurement is still evolving. We highlight challenges and opportunities for developing potential measures of "diagnostic safety" related to clinical diagnostic errors and associated preventable diagnostic harm. In doing so, we propose a starter set of measurement concepts for initial consideration that seem reasonably related to diagnostic safety and call for these to be studied and further refined. This would enable safe diagnosis to become an organizational priority and facilitate quality improvement. Health-care systems should consider measurement and evaluation of diagnostic performance as essential to timely and accurate diagnosis and to the reduction of preventable diagnostic harm.This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND), where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially without permission from the journal.

Comparing diagnostic tests on benefit-risk.

Science.gov (United States)

Pennello, Gene; Pantoja-Galicia, Norberto; Evans, Scott

2016-01-01

Comparing diagnostic tests on accuracy alone can be inconclusive. For example, a test may have better sensitivity than another test yet worse specificity. Comparing tests on benefit risk may be more conclusive because clinical consequences of diagnostic error are considered. For benefit-risk evaluation, we propose diagnostic yield, the expected distribution of subjects with true positive, false positive, true negative, and false negative test results in a hypothetical population. We construct a table of diagnostic yield that includes the number of false positive subjects experiencing adverse consequences from unnecessary work-up. We then develop a decision theory for evaluating tests. The theory provides additional interpretation to quantities in the diagnostic yield table. It also indicates that the expected utility of a test relative to a perfect test is a weighted accuracy measure, the average of sensitivity and specificity weighted for prevalence and relative importance of false positive and false negative testing errors, also interpretable as the cost-benefit ratio of treating non-diseased and diseased subjects. We propose plots of diagnostic yield, weighted accuracy, and relative net benefit of tests as functions of prevalence or cost-benefit ratio. Concepts are illustrated with hypothetical screening tests for colorectal cancer with test positive subjects being referred to colonoscopy.

Diagnostic reference levels in medical imaging

International Nuclear Information System (INIS)

Rosenstein, M.

2001-01-01

The paper proposes additional advice to national or local authorities and the clinical community on the application of diagnostic reference levels as a practical tool to manage radiation doses to patients in diagnostic radiology and nuclear medicine. A survey was made of the various approaches that have been taken by authoritative bodies to establish diagnostic reference levels for medical imaging tasks. There are a variety of ways to implement the idea of diagnostic reference levels, depending on the medical imaging task of interest, the national or local state of practice and the national or local preferences for technical implementation. The existing International Commission on Radiological Protection (ICRP) guidance is reviewed, the survey information is summarized, a set of unifying principles is espoused and a statement of additional advice that has been proposed to ICRP Committee 3 is presented. The proposed advice would meet a need for a unifying set of principles to provide a framework for diagnostic reference levels but would allow flexibility in their selection and use. While some illustrative examples are given, the proposed advice does not specify the specific quantities to be used, the numerical values to be set for the quantities or the technical details of how national or local authorities should implement diagnostic reference levels. (author)

Laboratory Information Systems in Molecular Diagnostics: Why Molecular Diagnostics Data are Different.

Science.gov (United States)

Lee, Roy E; Henricks, Walter H; Sirintrapun, Sahussapont J

2016-03-01

Molecular diagnostic testing presents new challenges to information management that are yet to be sufficiently addressed by currently available information systems for the molecular laboratory. These challenges relate to unique aspects of molecular genetic testing: molecular test ordering, informed consent issues, diverse specimen types that encompass the full breadth of specimens handled by traditional anatomic and clinical pathology information systems, data structures and data elements specific to molecular testing, varied testing workflows and protocols, diverse instrument outputs, unique needs and requirements of molecular test reporting, and nuances related to the dissemination of molecular pathology test reports. By satisfactorily addressing these needs in molecular test data management, a laboratory information system designed for the unique needs of molecular diagnostics presents a compelling reason to migrate away from the current paper and spreadsheet information management that many molecular laboratories currently use. This paper reviews the issues and challenges of information management in the molecular diagnostics laboratory.

Student Interpretations of Diagnostic Feedback

Science.gov (United States)

Doe, Christine

2015-01-01

Diagnostic assessment is increasingly being recognized as a potentially beneficial tool for teaching and learning (Jang, 2012). There have been calls in the research literature for students to receive diagnostic feedback and for researchers to investigate how such feedback is used by students. Therefore, this study examined how students…

21 CFR 886.1390 - Flexible diagnostic Fresnel lens.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Flexible diagnostic Fresnel lens. 886.1390 Section... (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1390 Flexible diagnostic Fresnel lens. (a) Identification. A flexible diagnostic Fresnel lens is a device that is a very thin lens which has...

Transformer engineering design, technology, and diagnostics

CERN Document Server

Kulkarni, SV

2012-01-01

Transformer Engineering: Design, Technology, and Diagnostics, Second Edition helps you design better transformers, apply advanced numerical field computations more effectively, and tackle operational and maintenance issues. Building on the bestselling Transformer Engineering: Design and Practice, this greatly expanded second edition also emphasizes diagnostic aspects and transformer-system interactions. What's New in This Edition Three new chapters on electromagnetic fields in transformers, transformer-system interactions and modeling, and monitoring and diagnostics An extensively revised chap

Diagnostic Imaging in Snakes and Lizards

OpenAIRE

Banzato , Tommaso

2013-01-01

The increasing popularity of snakes and lizards as pets has led to an increasing demand of specialised veterinary duties in these animals. Diagnostic imaging is often a fundamental step of the clinical investigation. The interpretation of diagnostic images is complex and requires a broad knowledge of anatomy, physiology and pathology of the species object of the clinical investigation. Moreover, in order to achieve a correct diagnosis, the comparison between normal and abnormal diagnostic im...

Development of the Model of the System of Managerial Diagnostics of the Enterprise on the Basis of Improvement of Diagnostic Purposes

Directory of Open Access Journals (Sweden)

Grzegorz Pawlowski

2017-11-01

Full Text Available The purpose of the article is to develop a model of the system of managerial diagnostics of the enterprise on the basis of the improvement of diagnostic purposes. The developed model of the system of managerial diagnostics of the enterprise is a set of subjects (owners, managers, investors, specialists, etc., objects (management system, resources, technology, methods (a set of methods and means, business indicators and criteria (parameters that, when interacting, provide the achievement (efficient and effective of the diagnostic objectives of the system of the objectives of managerial diagnostics of the enterprise, taking into account the compliance of its competitive strategy of the state of the environment function of direct action (competitors, customers, suppliers, mediators, and other contact audiences in the context of improving the efficiency and developing the management. It is determined that the system of goals of the model of the system of managerial diagnostics of the enterprise (taking into account the ensuring of the compliance of the system of management with strategic goals and tactical tasks form the following key diagnostic objectives that require improvement on the basis of business indicators (parameters, namely: 1 diagnostics of the effectiveness of controlling the internal business processes of the enterprise; 2 diagnostics of the effectiveness of the typical organizational structure of enterprise management; 3 diagnostics of the efficiency of standardization of the work of linear and functional managers and specialists at the enterprise; 4 diagnostics of the enterprise in the areas of vocational education, labor activity and motivation, innovation work and social development; 5 diagnostics of the level of conflict in the team at the enterprise; 6 diagnostics of efficiency of use of information technologies in the management of the enterprise. The prospect of further research in this area is to improve the complex system of

21 CFR 870.1425 - Programmable diagnostic computer.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Programmable diagnostic computer. 870.1425 Section 870.1425 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... diagnostic computer. (a) Identification. A programmable diagnostic computer is a device that can be...

Proposed diagnostic criteria for internet addiction.

Science.gov (United States)

Tao, Ran; Huang, Xiuqin; Wang, Jinan; Zhang, Huimin; Zhang, Ying; Li, Mengchen

2010-03-01

The objective of this study was to develop diagnostic criteria for internet addiction disorder (IAD) and to evaluate the validity of our proposed diagnostic criteria for discriminating non-dependent from dependent internet use in the general population. This study was conducted in three stages: the developmental stage (110 subjects in the survey group; 408 subjects in the training group), where items of the proposed diagnostic criteria were developed and tested; the validation stage (n = 405), where the proposed criteria were evaluated for criterion-related validity; and the clinical stage (n = 150), where the criteria and the global clinical impression of IAD were evaluated by more than one psychiatrist to determine inter-rater reliability. The proposed internet addiction diagnostic criteria consisted of symptom criterion (seven clinical symptoms of IAD), clinically significant impairment criterion (functional and psychosocial impairments), course criterion (duration of addiction lasting at least 3 months, with at least 6 hours of non-essential internet usage per day) and exclusion criterion (exclusion of dependency attributed to psychotic disorders). A diagnostic score of 2 + 1, where the first two symptoms (preoccupation and withdrawal symptoms) and at least one of the five other symptoms (tolerance, lack of control, continued excessive use despite knowledge of negative effects/affects, loss of interests excluding internet, and use of the internet to escape or relieve a dysphoric mood) was established. Inter-rater reliability was 98%. Our findings suggest that the proposed diagnostic criteria may be useful for the standardization of diagnostic criteria for IAD.

Automated diagnostics scoping study. Final report

Energy Technology Data Exchange (ETDEWEB)

Quadrel, R.W.; Lash, T.A.

1994-06-01

The objective of the Automated Diagnostics Scoping Study was to investigate the needs for diagnostics in building operation and to examine some of the current technologies in automated diagnostics that can address these needs. The study was conducted in two parts. In the needs analysis, the authors interviewed facility managers and engineers at five building sites. In the technology survey, they collected published information on automated diagnostic technologies in commercial and military applications as well as on technologies currently under research. The following describe key areas that the authors identify for the research, development, and deployment of automated diagnostic technologies: tools and techniques to aid diagnosis during building commissioning, especially those that address issues arising from integrating building systems and diagnosing multiple simultaneous faults; technologies to aid diagnosis for systems and components that are unmonitored or unalarmed; automated capabilities to assist cause-and-effect exploration during diagnosis; inexpensive, reliable sensors, especially those that expand the current range of sensory input; technologies that aid predictive diagnosis through trend analysis; integration of simulation and optimization tools with building automation systems to optimize control strategies and energy performance; integration of diagnostic, control, and preventive maintenance technologies. By relating existing technologies to perceived and actual needs, the authors reached some conclusions about the opportunities for automated diagnostics in building operation. Some of a building operator`s needs can be satisfied by off-the-shelf hardware and software. Other needs are not so easily satisfied, suggesting directions for future research. Their conclusions and suggestions are offered in the final section of this study.

CRISIS-DIAGNOSTICS IN ANTI-CRISIS MANAGEMENT

Directory of Open Access Journals (Sweden)

Gavrylenko Valentina

2018-01-01

Full Text Available Introduction. In today’s conditions of a changing market environment, uncertainty and risk, one of the main tasks of management is the timely detection of crisis symptoms and the development of measures aimed at preventing their negative impact on the activities of the enterprise. The purpose of this article is to determine the accounting and analytical information for the development of the model KRIZІS-diagnostics and ensure the effectiveness of its functioning in anti-crisis management. Results. The analysis of definition of the concept «KRIZІS-diagnostics» in the scientific literature is carried out. Multi-factor models for assessing the financial status and the diagnostics of enterprises bankruptcy for different countries are presented. The specified classification of management KRIZІS-diagnostics is specified. The stages and tasks of KRIZІS-diagnostics are determined. The sources of information, which are determinants of the early symptoms of the crisis and necessary for KRIZІS-diagnostics are indicated and the characteristic is also given. Qualitative and quantitative indicators that characterize the business processes of the enterprise and can be used to analyze the state of the enterprise in a changing environment for preventing the crisis are determined. Conclusions. This approach of identifying crisis symptoms in business processes is the basis for managing an enterprise to make strategic management decisions in order to prevent a crisis at its early stages. The development of KRIZІS-diagnostics as an information provision for anti-crisis management is the direction of further research.

Image diagnostic of colonic diseases - controversial questions

International Nuclear Information System (INIS)

Pomakov, P.; Rizov, A.; Stancheva, I.

2013-01-01

In the system of colonic diseases' diagnostic algorithm, fibrocolonoscopy (FCS) is defined as 'Golden Standard'. By this reason some X-ray diagnostic methods - irrigography, etc. are currently not being used in a number of health institutions. The aim of this study is a comparative analysis of FCS and irrigography diagnostic efficacy in various colonic diseases. For 10-years period, in cooperation with a gastroenterologist-gastroscopist, 2151 patients with various colonic diseases were evaluated by FCS and irrigography with pharmaco-diagnostics/when necessary. Advantage of FCS was established in diagnosing diseases with patho-morfologic changes on the inner surface of the colon - benign and malignant neoplastic processes, chronic inflammatory diseases, etc. At the same time functional changes - irritated colon syndrome, changes in defecation act, etc., are not an object of diagnosis through FCS. Correction in colonic diseases diagnostic algorithm is necessary. FCS should be mandatory. If result is negative - irrigography with pharmaco-diagnostics should be done. (authors)

Personalized estimates of radiation dose from dedicated breast CT in a diagnostic population and comparison with diagnostic mammography

International Nuclear Information System (INIS)

Vedantham, Srinivasan; Shi, Linxi; Karellas, Andrew; O'Connell, Avice M; Conover, David L

2013-01-01

This study retrospectively analyzed the mean glandular dose (MGD) to 133 breasts from 132 subjects, all women, who participated in a clinical trial evaluating dedicated breast CT in a diagnostic population. The clinical trial was conducted in adherence to a protocol approved by institutional review boards and the study participants provided written informed consent. Individual estimates of MGD to each breast from dedicated breast CT was obtained by combining x-ray beam characteristics with estimates of breast dimensions and fibroglandular fraction from volumetric breast CT images, and using normalized glandular dose coefficients. For each study participant and for the breast corresponding to that imaged with breast CT, an estimate of the MGD from diagnostic mammography (including supplemental views) was obtained from the DICOM image headers for comparison. This estimate uses normalized glandular dose coefficients corresponding to a breast with 50% fibroglandular weight fraction. The median fibroglandular weight fraction for the study cohort determined from volumetric breast CT images was 15%. Hence, the MGD from diagnostic mammography was corrected to be representative of the study cohort. Individualized estimates of MGD from breast CT ranged from 5.7 to 27.8 mGy. Corresponding to the breasts imaged with breast CT, the MGD from diagnostic mammography ranged from 2.6 to 31.6 mGy. The mean (± inter-breast SD) and the median MGD (mGy) from dedicated breast CT exam were 13.9 ± 4.6 and 12.6, respectively. For the corresponding breasts, the mean (± inter-breast SD) and the median MGD (mGy) from diagnostic mammography were 12.4 ± 6.3 and 11.1, respectively. Statistical analysis indicated that at the 0.05 level, the distributions of MGD from dedicated breast CT and diagnostic mammography were significantly different (Wilcoxon signed ranks test, p = 0.007). While the interquartile range and the range (maximum–minimum) of MGD from dedicated breast CT was lower than

Screening diagnostic program breast cancer

International Nuclear Information System (INIS)

Portnoj, L.M.; Zhakova, I.I.; Budnikova, N.V.; Rukhlyadko, E.D.

1995-01-01

The authors propose their screening program for detection of breast cancer. It includes the entire complex of present-day screening diagnostic methods, starting from an original system for the formation of groups at risk of breast cancer and completed by the direct diagnostic model of detection of the condition, oriented at a differentiated approach to the use of mammographic techniques. The proposed organizational and methodologic screening measures are both economic and diagnostically effective, thus meeting the principal requirements to screening programs. Screening of 8541 risk-groups patients helped detect 867 nodular formations, 244 of which were cancer and 623 benign formations. 8 refs., 3 figs.,

Dual Processing and Diagnostic Errors

Science.gov (United States)

Norman, Geoff

2009-01-01

In this paper, I review evidence from two theories in psychology relevant to diagnosis and diagnostic errors. "Dual Process" theories of thinking, frequently mentioned with respect to diagnostic error, propose that categorization decisions can be made with either a fast, unconscious, contextual process called System 1 or a slow, analytical,…

Validation of the ELISA technique for diagnosis of trypanosomiasis in cattle in Uganda

International Nuclear Information System (INIS)

Okuna, N.M.

1992-01-01

ELISA, developed in ILRAD for diagnosis of T. congolense, T. brucei and T. vivax in cattle, has not been validated in Uganda. This study was undertaken to validate the technique. Negative reference sera were collected from 44 cattle in Kapchorwa, a tsetse-free area. The cattle were free of the three trypanosome species T. congolense, T. brucei and T. vivax by the haematocrit buffy coat technique (BCT). But by ELISA, three were positive for T. vivax, one for both T. congolense and T. vivax and one for T. congolense. Sera were collected from the same 44 cattle 10 weeks later. The cattle were again free of T. congolense, T. brucei and T. vivax, both by BCT and by mouse inoculations. Two cattle out of 450 screened at a centre 5 km away had T. vivax by BCT. The ELISA results for the second set of sera were quite similar to the results obtained from the first set of sera. The calculated optical density (D) cut off point was 50 for both T. brucei and T. vivax, but it was 60 for T. congolense. Sera from 5 cattle which had T. theileri and two which had microfilaria were all negative for antigenaemia by ELISA. Positive reference sera were collected form 40 cattle in a high tsetse challenge area. Using the haematocrit buffy coat technique, 5 had T. vivax, two had T. brucei and one had T. congolense. Checked by ELISA for antigenaemia, only 4 cattle were free of all the three trypanosome species, T. congolense, T. vivax and T. brucei. All the 40 cattle were treated with Diminazene aceturate at the rate of 7 mg/kg body weight. Two weeks later, the ELISA test showed that 10 cattle were free of any antigenaemia. Those still positive for antigenaemia had lower OD readings. The ELISA technique is valid. It is much more sensitive compared to parasitological tests. It is specific since none of the 7 cattle with either T. theileri or microfilaria gave positive results by ELISA. The technique would be very useful for epizootiological studies. (author)

User interface graphically improves generator AL diagnostics

International Nuclear Information System (INIS)

Gray, R.F.; King, I.J.

1991-01-01

In April of 1990, the recently developed Diagnostic Graphical User Interface (DGUI) was installed at a large nuclear power plant in the midwestern United States. Since 1988, the power plant has been using the Generator Artificial Intelligence Diagnostics (GenAID) System, which provides online diagnostic capability for the generator and generator auxiliaries through a plant data center (PDC) and communication link to the diagnostic operations center (DOC) in Orlando, Florida. The enhanced system provides the power plant control room operator with a comprehensive tool to understand and better utilize the information provided by the existing knowledge bases. This paper represents a significant improvement over existing technology by providing the power plant control room operator with the capability of interacting directly with the diagnostic system

21 CFR 886.1395 - Diagnostic Hruby fundus lens.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Diagnostic Hruby fundus lens. 886.1395 Section 886...) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1395 Diagnostic Hruby fundus lens. (a) Identification. A diagnostic Hruby fundus lens is a device that is a 55 diopter lens intended for use in the...

MOLECULAR DIAGNOSTICS OF YERSINIA RUCKERI

Directory of Open Access Journals (Sweden)

Yu. Rud

2014-06-01

Full Text Available Purpose. The analysis of nucleotide sequences of the 16S rDNA gene of virulent strains of Yersinia ruckeri and to develop the method of molecular diagnostic of enteric redmouth disease. Methodology. By the method of CLUSTALW algorithm in MEGA software version 6.0 the nucleotide sequences of the 16S rDNA gene of virulent strains of Yersinia ruckeri were analysed. For development of molecular diagnostic of Y. ruckeri the method of polymerase chain reaction (PCR was used. Primer selection was carried out in software VectorNTI11 and on-line-service BLAST. The PCR products were investigated by the methods of sequencing and nucleotide analysis. Findings. Based on PCR assay the method of molecular diagnostic of enteric redmouth disease agent, bacterium Y. ruckeri was developed. It was shown that specific oligonucleotide primers generated PCR products in size of 600 base pairs. PCR products were investigated by the sequencing that showed right targeting of primers in reaction. Originality. Among high-conservative gene of 16S rDNA of Y. ruckeri the fragment of DNA was determined to which the specific primers for rapid diagnostic of virulent strains were selected. Practical Value. Rapid diagnostic of yersiniosis will allow to identify an agent of this infectious disease, bacterium Y. ruckeri, and to provide the prophylactic or medical measures in the fish farming of Ukraine.

IMPLEMENTATION OF TURNOUTS TECHNICAL DIAGNOSTICS SYSTEMS

Directory of Open Access Journals (Sweden)

S. YU. Buryak

2015-06-01

Full Text Available Purpose. In the paper it is necessary to: 1 find out the causes of turnouts faults to determine diagnostic features failures; 2 consider the requirements structure, purpose components of turnouts, work and technology of their maintenance to determine the construction of the economic activities related to system to the turnout’s maintenance; 3 substantiate the possibility, necessity and prospects of automated diagnostics turnout’s implementation; 4 elaborate a prototype of an automated hardware and software system for the turnouts control parameters and perform diagnostics on them. Methodology. In the paper possible turnouts faults were presented and manifestations and influence on its work were shown. According to the current technology works the process analyze of turnouts’ maintenance was conducted, were defined the basic performed operations during the examination of appearance, parameters and check the repair or replacement of parts and assemblies. Based on the analysis of reasons of turnouts malfunctioning and their fixes were systematized types of damages and ways to deal with them, an information scheme of troubleshooting were created, opportunities and limits of automating the process of diagnostics were identified and compared with the existing method of turnouts maintenance. A diagnostics system block diagram was created, an algorithm of its work was developed and established main basic principles of operation. Software and hardware to determine the turnout’s state considering diagnostic performance of points in use were applied. Findings. During the experiment was created a method of automated turnout’s diagnostics with AC electric drives, managed centrally. The results of automated hardware and software system make it possible to control turnout’s parameters and perform diagnostics on them. Originality. Authors created the method of turnout’s state determination by current curve and its spectral composition in the

Allicin and derivates are cysteine protease inhibitors with antiparasitic activity.

Science.gov (United States)

Waag, Thilo; Gelhaus, Christoph; Rath, Jennifer; Stich, August; Leippe, Matthias; Schirmeister, Tanja

2010-09-15

Allicin and derivatives thereof inhibit the CAC1 cysteine proteases falcipain 2, rhodesain, cathepsin B and L in the low micromolar range. The structure-activity relationship revealed that only derivatives with primary carbon atom in vicinity to the thiosulfinate sulfur atom attacked by the active-site Cys residue are active against the target enzymes. Some compounds also show potent antiparasitic activity against Plasmodium falciparum and Trypanosoma brucei brucei. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

[Cytology in uropathological diagnostics].

Science.gov (United States)

Gaisa, N T; Lindemann-Docter, K

2015-11-01

Cytology in uropathological diagnostics is mainly performed for oncological purposes. The assessment of malignancy by urothelial cell morphology is therefore decisive; however, cytology is only sensitive enough to detect high-grade tumor cells and the different low-grade tumors cannot be reliably diagnosed. Thus, the four-tier classification system of cytological findings (i.e. negative, atypical cells but significance uncertain, suspicious and positive) refers to high-grade tumor cells only. Furthermore, for valid cytological diagnostics not only the cytological specimen but also clinical information on cystoscopy findings and, if applicable, a biopsy should be evaluated together. In difficult differential diagnostic settings, e.g. differentiation between reactive versus neoplastic atypia or difficult to access lesions in the upper urinary tract, additional fluorescence in situ hybridization of cytological preparations might be helpful. At the moment there are no indications for further immunocytology or additional biomarker tests.

ORION laser target diagnostics

International Nuclear Information System (INIS)

Bentley, C. D.; Edwards, R. D.; Andrew, J. E.; James, S. F.; Gardner, M. D.; Comley, A. J.; Vaughan, K.; Horsfield, C. J.; Rubery, M. S.; Rothman, S. D.; Daykin, S.; Masoero, S. J.; Palmer, J. B.; Meadowcroft, A. L.; Williams, B. M.; Gumbrell, E. T.; Fyrth, J. D.; Brown, C. R. D.; Hill, M. P.; Oades, K.

2012-01-01

The ORION laser facility is one of the UK's premier laser facilities which became operational at AWE in 2010. Its primary mission is one of stockpile stewardship, ORION will extend the UK's experimental plasma physics capability to the high temperature, high density regime relevant to Atomic Weapons Establishment's (AWE) program. The ORION laser combines ten laser beams operating in the ns regime with two sub ps short pulse chirped pulse amplification beams. This gives the UK a unique combined long pulse/short pulse laser capability which is not only available to AWE personnel but also gives access to our international partners and visiting UK academia. The ORION laser facility is equipped with a comprehensive suite of some 45 diagnostics covering optical, particle, and x-ray diagnostics all able to image the laser target interaction point. This paper focuses on a small selection of these diagnostics.

ORION laser target diagnostics.

Science.gov (United States)

Bentley, C D; Edwards, R D; Andrew, J E; James, S F; Gardner, M D; Comley, A J; Vaughan, K; Horsfield, C J; Rubery, M S; Rothman, S D; Daykin, S; Masoero, S J; Palmer, J B; Meadowcroft, A L; Williams, B M; Gumbrell, E T; Fyrth, J D; Brown, C R D; Hill, M P; Oades, K; Wright, M J; Hood, B A; Kemshall, P

2012-10-01

The ORION laser facility is one of the UK's premier laser facilities which became operational at AWE in 2010. Its primary mission is one of stockpile stewardship, ORION will extend the UK's experimental plasma physics capability to the high temperature, high density regime relevant to Atomic Weapons Establishment's (AWE) program. The ORION laser combines ten laser beams operating in the ns regime with two sub ps short pulse chirped pulse amplification beams. This gives the UK a unique combined long pulse/short pulse laser capability which is not only available to AWE personnel but also gives access to our international partners and visiting UK academia. The ORION laser facility is equipped with a comprehensive suite of some 45 diagnostics covering optical, particle, and x-ray diagnostics all able to image the laser target interaction point. This paper focuses on a small selection of these diagnostics.

Some aspects of diagnostic systems perspective

International Nuclear Information System (INIS)

Korosec, D.

1998-01-01

The integrity and safety of all nuclear power plant systems and components is guaranteed by the high requirements to quality assurance during all phases of design, fabrication, construction and operation. Many of the countries operating nuclear facilities, introduced advanced, sophisticated diagnostic systems for continuous monitoring safety important process parameters. The licensee should perform an assessment of the existing diagnostic systems, often supplied by the original design, their reliability and the need for the introduction of the additional monitoring/diagnostic systems. The operating experience should be taken into account and the assessment of the further needs. On this field has to be made on the results of PSA studies. In addition to the cost benefit analysis the evaluation of the new diagnostic systems in the light of nuclear safety should be also made. Experience, gained from the utilities, which have already installed this kind of the equipment should be very useful. Introducing new diagnostic systems will require often a safety assessment of the necessary modifications. Licensing process should be based on the existing nuclear legislation with certain additional requirements. (author)

Characterization of a Novel Association between Two Trypanosome-Specific Proteins and 5S rRNA

Science.gov (United States)

Ciganda, Martin; Williams, Noreen

2012-01-01

P34 and P37 are two previously identified RNA binding proteins in the flagellate protozoan Trypanosoma brucei. RNA interference studies have determined that the proteins are essential and are involved in ribosome biogenesis. Here, we show that these proteins interact in vitro with the 5S rRNA with nearly identical binding characteristics in the absence of other cellular factors. The T. brucei 5S rRNA has a complex secondary structure and presents four accessible loops (A to D) for interactions with RNA-binding proteins. In other eukaryotes, loop C is bound by the L5 ribosomal protein and loop A mainly by TFIIIA. The binding of P34 and P37 to T. brucei 5S rRNA involves the LoopA region of the RNA, but these proteins also protect the L5 binding site located on LoopC. PMID:22253864

New heterocyclic compounds: Synthesis and antitrypanosomal properties.

Science.gov (United States)

Pomel, S; Dubar, F; Forge, D; Loiseau, P M; Biot, C

2015-08-15

Three new series of quinoline, quinolone, and benzimidazole derivatives were synthesized and evaluated in vitro against Trypanosoma brucei gambiense. In the quinoline series, the metallo antimalarial drug candidate (ferroquine, FQ) and its ruthenium analogue (ruthenoquine, RQ, compound 13) showed the highest in vitro activities with IC50 values around 0.1 μM. Unfortunately, both compounds failed to cure Trypanosoma brucei brucei infected mice in vivo. The other heterocyclic compounds were active in vitro with IC50 values varying from 0.8 to 34 μM. One of the most interesting results was a fluoroquinolone derivative (compound 2) that was able to offer a survival time of 8 days after a treatment at the single dose of 100 μmol/kg by intraperitoneal route. Although no clear-cut structure-activity relationships emerged, further pharmacomodulations are worth to be developed in this series. Copyright © 2015 Elsevier Ltd. All rights reserved.

Diagnostics for FIRE: A Status Report

International Nuclear Information System (INIS)

Kenneth M. Young

2002-01-01

The mission for the proposed FIRE (Fusion Ignition Research Experiment) device is to ''attain, explore, understand and optimize fusion-dominated plasmas.'' Operation at Q * 5, for 20 sec with a fusion power output of *150 MW is the major goal. Attaining this mission sets demands for plasma measurement that are at least as comprehensive as on present tokamaks, with the additional capabilities needed for control of the plasma and for understanding the effects of the alpha-particles. Because of the planned operation in advanced tokamak scenarios, with steep transport barriers, the diagnostic instrumentation must be able to provide fine spatial and temporal resolution. It must also be able to withstand the impact of the intense neutron and gamma irradiation. There are practical engineering issues of minimizing radiation streaming while providing essential diagnostic access to the plasma. Many components will operate close to the first wall, e.g. ceramics and mineral insulated cable for magnetic diagnostics and mirrors for optical diagnostics; these components must be selected and mounted so that they will operate and survive in fluxes which require special material selection. The measurement requirements have been assessed so that the diagnostics for the FIRE device can be defined. Clearly a better set of diagnostics of alpha-particles than that available for TFTR is essential, since the alpha-particles provide the dominant sources of heating and of instability-drive in the plasma

Nanotechnology based diagnostics for neurological disorders

Energy Technology Data Exchange (ETDEWEB)

Kurek, Nicholas S; Chandra, Sathees B., E-mail: schandra@roosevelt.edu [Department of Biological, Chemical and Physical Sciences, Roosevelt University, Chicago, IL (United States)

2012-07-01

Nanotechnology involves probing and manipulating matter at the molecular level. Nanotechnology based molecular diagnostics have the potential to alleviate the suffering caused by many diseases, including neurological disorders, due to the unique properties of nanomaterials. Most neurological illnesses are multifactorial conditions and many of these are also classified as neurobehavioral disorders. Alzheimer's disease, Parkinson's disease, Huntington disease, cerebral ischemia, epilepsy, schizophrenia and autism spectrum disorders like Rett syndrome are some examples of neurological disorders that could be better treated, diagnosed, prevented and possibly cured using nanotechnology. In order to improve the quality of life for disease afflicted people, a wide range of nanomaterials that include gold and silica nanoparticles, quantum dots and DNA along with countless other forms of nanotechnology have been investigated regarding their usefulness in advancing molecular diagnostics. Other small scaled materials like viruses and proteins also have potential for use as molecular diagnostic tools. Information obtained from nanotechnology based diagnostics can be stored and manipulated using bioinformatics software. More advanced nanotechnology based diagnostic procedures for the acquisition of even greater proteomic and genomic knowledge can then be developed along with better ways to fight various diseases. Nanotechnology also has numerous applications besides those related to biotechnology and medicine. In this article, we will discuss and analyze many novel nanotechnology based diagnostic techniques at our disposal today. (author)

Nanotechnology based diagnostics for neurological disorders

Energy Technology Data Exchange (ETDEWEB)

Kurek, Nicholas S.; Chandra, Sathees B., E-mail: schandra@roosevelt.edu [Department of Biological, Chemical and Physical Sciences, Roosevelt University, Chicago, IL (United States)

2012-07-01

Nanotechnology involves probing and manipulating matter at the molecular level. Nanotechnology based molecular diagnostics have the potential to alleviate the suffering caused by many diseases, including neurological disorders, due to the unique properties of nanomaterials. Most neurological illnesses are multifactorial conditions and many of these are also classified as neurobehavioral disorders. Alzheimer's disease, Parkinson's disease, Huntington disease, cerebral ischemia, epilepsy, schizophrenia and autism spectrum disorders like Rett syndrome are some examples of neurological disorders that could be better treated, diagnosed, prevented and possibly cured using nanotechnology. In order to improve the quality of life for disease afflicted people, a wide range of nanomaterials that include gold and silica nanoparticles, quantum dots and DNA along with countless other forms of nanotechnology have been investigated regarding their usefulness in advancing molecular diagnostics. Other small scaled materials like viruses and proteins also have potential for use as molecular diagnostic tools. Information obtained from nanotechnology based diagnostics can be stored and manipulated using bioinformatics software. More advanced nanotechnology based diagnostic procedures for the acquisition of even greater proteomic and genomic knowledge can then be developed along with better ways to fight various diseases. Nanotechnology also has numerous applications besides those related to biotechnology and medicine. In this article, we will discuss and analyze many novel nanotechnology based diagnostic techniques at our disposal today. (author)

Diagnostic imaging in intensive care patients

International Nuclear Information System (INIS)

Afione, Cristina; Binda, Maria del C.

2004-01-01

Purpose: To determine the role of imaging diagnostic methods in the location of infection causes of unknown origin in the critical care patient. Material and methods: A comprehensive medical literature search has been done. Recommendations for the diagnostic imaging of septic focus in intensive care patients are presented for each case, with analysis based on evidence. The degree of evidence utilized has been that of Oxford Center for Evidence-based Medicine. Results: Nosocomial infection is the most frequent complication in the intensive care unit (25 to 33%) with high sepsis incidence rate. In order to locate the infection focus, imaging methods play an important role, as a diagnostic tool and to guide therapeutic procedures. The most frequent causes of infection are: ventilation associated pneumonia, sinusitis, intra-abdominal infections and an acute acalculous cholecystitis. This paper analyses the diagnostic imaging of hospital infection, with the evaluation of choice methods for each one and proposes an algorithm to assess the septic patient. Conclusion: There are evidences, with different degrees of recommendation, for the use of diagnostic imaging methods for infectious focuses in critical care patients. The studies have been selected based on their diagnostic precision, on the capacity of the medical team and on the availability of resources, considering the risk-benefit balance for the best safety of the patient. (author)

Nanotechnology based diagnostics for neurological disorders

International Nuclear Information System (INIS)

Kurek, Nicholas S.; Chandra, Sathees B.

2012-01-01

Nanotechnology involves probing and manipulating matter at the molecular level. Nanotechnology based molecular diagnostics have the potential to alleviate the suffering caused by many diseases, including neurological disorders, due to the unique properties of nanomaterials. Most neurological illnesses are multifactorial conditions and many of these are also classified as neurobehavioral disorders. Alzheimer's disease, Parkinson's disease, Huntington disease, cerebral ischemia, epilepsy, schizophrenia and autism spectrum disorders like Rett syndrome are some examples of neurological disorders that could be better treated, diagnosed, prevented and possibly cured using nanotechnology. In order to improve the quality of life for disease afflicted people, a wide range of nanomaterials that include gold and silica nanoparticles, quantum dots and DNA along with countless other forms of nanotechnology have been investigated regarding their usefulness in advancing molecular diagnostics. Other small scaled materials like viruses and proteins also have potential for use as molecular diagnostic tools. Information obtained from nanotechnology based diagnostics can be stored and manipulated using bioinformatics software. More advanced nanotechnology based diagnostic procedures for the acquisition of even greater proteomic and genomic knowledge can then be developed along with better ways to fight various diseases. Nanotechnology also has numerous applications besides those related to biotechnology and medicine. In this article, we will discuss and analyze many novel nanotechnology based diagnostic techniques at our disposal today. (author)

Diagnostics for pellet experiments

International Nuclear Information System (INIS)

Johnson, R.R.

1978-01-01

The target diagnostics which are being used and planned in current laser driven ICF Experiments are described. Most of these diagnostics can be easily applied to future ion-beam fusion experiments. The status of laser fusion diagnostics has been much improved in the last 5 years and further improvements can be expected and should be available when the first ICF experiments using ion beams are performed. As an example, x-ray temporal and spatial resolutions are now approximately 5 psec and 3 μm, which is approximately a factor of 4 better than the resolution reported in the first implosion experiments. As one plans ahead for ion-beam fusion experiments it should be emphasized that high yield experiments are easier to diagnose provided adequate shielding is employed. However, in the event that the first high yield experiments fail it will be necessary to have diagnostics available to determine where the problems lie. In laser fusion it is interesting to note that higher laser powers are required now for breakeven experiments than first anticipated, mainly because some aspects of the laser-interaction physics were not recognized until the experiments were carefully diagnosed. Thus as has been pointed out, it may be necessary to increase the energy of the ion-beam driver to enable us to do breakeven experiments with high confidence

Diagnostic and interventional radiology

Energy Technology Data Exchange (ETDEWEB)

Vogl, Thomas J. [Klinikum der Johann Wolfgang Goethe-Universitaet, Frankfurt am Main (Germany). Inst. fuer Diagnostische und Interventionelle Radiologie; Reith, Wolfgang [Universitaetsklinikum des Saarlandes, Homburg/Saar (Germany). Klinik fuer Diagnostische und Interventionelle Neuroradiologie; Rummeny, Ernst J. (ed.) [Technische Univ. Muenchen Klinikum rechts der Isar, Muenchen (Germany). Inst. fuer Radiologie

2016-08-01

This exceptional book covers all aspects of diagnostic and interventional radiology within one volume, at a level appropriate for the specialist. From the basics through diagnosis to intervention: the reader will find a complete overview of all areas of radiology. The clear, uniform structure, with chapters organized according to organ system, facilitates the rapid retrieval of information. Features include: Presentation of the normal radiological anatomy Classification of the different imaging procedures according to their diagnostic relevance Imaging diagnosis with many reference images Precise description of the interventional options The inclusion of many instructive aids will be of particular value to novices in decision making: Important take home messages and summaries of key radiological findings smooth the path through the jungle of facts Numerous tables on differential diagnosis and typical findings in the most common diseases offer a rapid overview and orientation Diagnostic flow charts outline the sequence of diagnostic evaluation All standard procedures within the field of interventional radiology are presented in a clinically relevant and readily understandable way, with an abundance of illustrations. This is a textbook, atlas, and reference in one: with more than 2500 images for comparison with the reader's own findings. This comprehensive and totally up-to-date book provides a superb overview of everything that the radiology specialist of today needs to know.

Developmentally sensitive diagnostic criteria for mental health disorders in early childhood: the diagnostic and statistical manual of mental disorders-IV, the research diagnostic criteria-preschool age, and the diagnostic classification of mental health and developmental disorders of infancy and early childhood-revised.

Science.gov (United States)

Egger, Helen L; Emde, Robert N

2011-01-01

As the infant mental health field has turned its focus to the presentation, course, and treatment of clinically significant mental health disorders, the need for reliable and valid criteria for identifying and assessing mental health symptoms and disorders in early childhood has become urgent. In this article we offer a critical perspective on diagnostic classification of mental health disorders in young children. We place the issue of early childhood diagnosis within the context of classification of psychopathology at other ages and describe, in some detail, diagnostic classifications that have been developed specifically for young children, including the Diagnostic Classification of Mental Health and Developmental Disorders of Infancy and Early Childhood (DC:0-3R; ZERO TO THREE, 2005), a diagnostic classification for mental health symptoms and disorders in infants, toddlers, and preschoolers. We briefly outline the role of diagnostic classification in clinical assessment and treatment planning. Last, we review the limitations of current approaches to the diagnostic classification of mental health disorders in young children. PsycINFO Database Record (c) 2010 APA, all rights reserved.

Blood culture-negative endocarditis: Improving the diagnostic yield using new diagnostic tools.

Science.gov (United States)

Fournier, Pierre-Edouard; Gouriet, Frédérique; Casalta, Jean-Paul; Lepidi, Hubert; Chaudet, Hervé; Thuny, Franck; Collart, Frédéric; Habib, Gilbert; Raoult, Didier

2017-11-01

Blood culture-negative endocarditis (BCNE) may represent up to 70% of all endocarditis cases, depending on series. From 2001 to 2009, we implemented in our laboratory a multimodal diagnostic strategy for BCNE that included systematized testing of blood, and when available, valvular biopsy specimens using serological, broad range molecular, and histopathological assays. A causative microorganism was identified in 62.7% of patients.In this study from January 2010 to December 2015, in an effort to increase the number of identified causative microorganisms, we prospectively added to our diagnostic protocol specific real-time (RT) polymerase chain reaction (PCR) assays targeting various endocarditis agents, and applied them to all patients with BCNE admitted to the 4 public hospitals in Marseille, France.A total of 283 patients with BCNE were included in the study. Of these, 177 were classified as having definite endocarditis. Using our new multimodal diagnostic strategy, we identified an etiology in 138 patients (78.0% of cases). Of these, 3 were not infective (2.2%) and 1 was diagnosed as having Mycobacterium bovis BCG endocarditis. By adding specific PCR assays from blood and valvular biopsies, which exhibited a significantly greater sensitivity (P < 10) than other methods, causative agents, mostly enterococci, streptococci, and zoonotic microorganisms, were identified in an additional 27 patients (14 from valves only, 11 from blood only, and 2 from both). Finally, in another 107 patients, a pathogen was detected using serology in 37, valve culture in 8, broad spectrum PCR from valvular biopsies and blood in 19 and 2, respectively, immunohistochemistry from valves in 3, and a combination of several assays in 38.By adding specific RT-PCR assays to our systematic PCR testing of patients with BCNE, we increased the diagnostic efficiency by 24.3%, mostly by detecting enterococci and streptococci that had not been detected by other diagnostic methods, but also agents

Progress on the MSE diagnostic for ITER

International Nuclear Information System (INIS)

Lotte, Ph.; Giannella, R.; Von Hellermann, M.; Kuldkepp, M.; Rachlew, E.; Malaquias, A.; Costley, A.; Walker, C.

2004-01-01

The Motional Stark Effect (MSE) diagnostic is now considered as an essential diagnostic for an accurate determination of current profiles in tokamak discharges. It mainly allows a measurement of the direction of the total magnetic field, a very powerful constraint for the determination of the safety factor profile. The realisation of such a diagnostic on ITER implies to face new challenges, because of the bigger size of the machine and of its hard environment. Now, most of the foreseen difficulties have been examined, solutions envisaged, and we propose to review them in this paper. This article is divided into 3 parts: 1) principle of the MSE diagnostic and its feasibility at higher Lorentz electric fields, 2) spatial and time resolution of the diagnostic, and 3) the light collection system

Diagnostic imaging of shoulder impingement

International Nuclear Information System (INIS)

Merl, T.; Weinhardt, H.; Oettl, G.; Lenz, M.; Riel, K.A.

1996-01-01

Magnetic resonance imaging is a method that has been advancing in the last few years to the modality of choice for diagnostic evaluation of the bone joints, as the method is capable of imaging not only the ossous but also the soft tissue components of the joint. MRI likewise has become an accepted method for diagnostic evaluation of syndromes of the shoulder, with high diagnostic accuracy in detecting rotator cuff lesions, or as an efficient MRI arthrography for evaluation of the instability or lesions of the labrocapsular complex. In the evaluation of early stages of shoulder impingement, the conventional MRI technique as a static technique yields indirect signs which in many cases do not provide the diagnostic certainty required in order to do justice to the functional nature of the syndrome. In these cases, functional MRI for imaging of the arm in abducted position and in rotational movement may offer a chance to early detect impingement and thus identify patients who will profit from treatment at an early stage [de

The next organizational challenge: finding and addressing diagnostic error.

Science.gov (United States)

Graber, Mark L; Trowbridge, Robert; Myers, Jennifer S; Umscheid, Craig A; Strull, William; Kanter, Michael H

2014-03-01

Although health care organizations (HCOs) are intensely focused on improving the safety of health care, efforts to date have almost exclusively targeted treatment-related issues. The literature confirms that the approaches HCOs use to identify adverse medical events are not effective in finding diagnostic errors, so the initial challenge is to identify cases of diagnostic error. WHY HEALTH CARE ORGANIZATIONS NEED TO GET INVOLVED: HCOs are preoccupied with many quality- and safety-related operational and clinical issues, including performance measures. The case for paying attention to diagnostic errors, however, is based on the following four points: (1) diagnostic errors are common and harmful, (2) high-quality health care requires high-quality diagnosis, (3) diagnostic errors are costly, and (4) HCOs are well positioned to lead the way in reducing diagnostic error. FINDING DIAGNOSTIC ERRORS: Current approaches to identifying diagnostic errors, such as occurrence screens, incident reports, autopsy, and peer review, were not designed to detect diagnostic issues (or problems of omission in general) and/or rely on voluntary reporting. The realization that the existing tools are inadequate has spurred efforts to identify novel tools that could be used to discover diagnostic errors or breakdowns in the diagnostic process that are associated with errors. New approaches--Maine Medical Center's case-finding of diagnostic errors by facilitating direct reports from physicians and Kaiser Permanente's electronic health record--based reports that detect process breakdowns in the followup of abnormal findings--are described in case studies. By raising awareness and implementing targeted programs that address diagnostic error, HCOs may begin to play an important role in addressing the problem of diagnostic error.

Myasthenia Gravis: Tests and Diagnostic Methods

Science.gov (United States)

... Focus on MG Newsletter MG Quarterly Test & Diagnostic methods In addition to a complete medical and neurological ... How can I help? About MGFA Test & Diagnostic methods Treatment for MG FAQ's Upcoming Events 2018 MG ...

Diagnostic accuracy in virtual dermatopathology

DEFF Research Database (Denmark)

Mooney, E.; Kempf, W.; Jemec, G.B.E.

2012-01-01

Background Virtual microscopy is used for teaching medical students and residents and for in-training and certification examinations in the United States. However, no existing studies compare diagnostic accuracy using virtual slides and photomicrographs. The objective of this study was to compare...... diagnostic accuracy of dermatopathologists and pathologists using photomicrographs vs. digitized images, through a self-assessment examination, and to elucidate assessment of virtual dermatopathology. Methods Forty-five dermatopathologists and pathologists received a randomized combination of 15 virtual...... slides and photomicrographs with corresponding clinical photographs and information in a self-assessment examination format. Descriptive data analysis and comparison of groups were performed using a chi-square test. Results Diagnostic accuracy in dermatopathology using virtual dermatopathology...

The Added Value of the Combined Use of the Autism Diagnostic Interview-Revised and the Autism Diagnostic Observation Schedule: Diagnostic Validity in a Clinical Swedish Sample of Toddlers and Young Preschoolers

Science.gov (United States)

Zander, Eric; Sturm, Harald; Bölte, Sven

2015-01-01

The diagnostic validity of the new research algorithms of the Autism Diagnostic Interview-Revised and the revised algorithms of the Autism Diagnostic Observation Schedule was examined in a clinical sample of children aged 18-47 months. Validity was determined for each instrument separately and their combination against a clinical consensus…

Scaling-Up the Functional Diagnostic Systems

International Nuclear Information System (INIS)

Mohamed, A.H.

2008-01-01

Functional diagnostic systems received a lot of attention in the last decade. They have proven their powerful for diagnosis the new faults of some complex systems. But, they still have some complexity in both the representation and reasoning about the large-scale systems. This paper introduces a new functional diagnostic system that can divide its small functions into main and auxiliary ones. This process enables the diagnostic system to scale -up the representation of the tested system and simplify the diagnostic mechanism tasks. Thus, it can improve both the representation and reasoning complexity. Also,it can decrease the required analysis, cost, and time. Proposed system can be applied for a wide area of the large-scale systems. It has been proven its acceptance to be applied practically for the Complex real-time systems

Patterns of anaphylaxis after diagnostic workup

DEFF Research Database (Denmark)

Oropeza, Athamaica Ruiz; Bindslev-Jensen, Carsten; Broesby-Olsen, Sigurd

2017-01-01

BACKGROUND: Most published studies on anaphylaxis are retrospective or register based. Data on subsequent diagnostic work-up are sparse. We aimed to characterize patients seen with suspected anaphylaxis at the emergency care setting (ECS), after subsequent diagnostic work-up at our Allergy Center...... (AC). METHODS: Prospective study including patients from the ECS, Odense University Hospital, during May 2013-April 2014. Possible anaphylaxis cases were daily identified based on a broad search profile including history and symptoms in patient records, diagnostic codes and pharmacological treatments....... At the AC, all patients were evaluated according to international guidelines. RESULTS: Among 226 patients with suspected anaphylaxis, the diagnosis was confirmed in 124 (54.9%) after diagnostic work-up; 118 of the 124 fulfilled WAO/EAACI criteria of anaphylaxis at the ECS, while 6 were found among 46...

Target diagnostic system for the National Ignition Facility (NIF)

International Nuclear Information System (INIS)

Leeper, R.J.; Chandler, G.A.; Cooper, G.W.; Derzon, M.S.

1996-01-01

A review of recent progress on the design of a diagnostic system proposed for ignition target experiments on the National Ignition Facility (NIF) will be presented. This diagnostic package contains an extensive suite of optical, x-ray, gamma-ray, and neutron diagnostics that enable measurements of the performance of both direct and indirect driven NIF targets. The philosophy used in designing all of the diagnostics in the set has emphasized redundant and independent measurement of fundamental physical quantities relevant to the operation of the NIF target. A unique feature of these diagnostics is that they are being designed to be capable of operating, in the high radiation, EMP, and debris backgrounds expected on the NIF facility. The diagnostic system proposed can be categorized into three broad areas: laser characterization, hohlraum characterization, and capsule performance diagnostics. The operating principles of a representative instrument from each class of diagnostic employed in this package will be summarized and illustrated with data obtained in recent prototype diagnostic tests

Algorithm of Functional Musculoskeletal Disorders Diagnostics

OpenAIRE

Alexandra P. Eroshenko

2012-01-01

The article scientifically justifies the algorithm of complex diagnostics of functional musculoskeletal disorders during resort treatment, aimed at the optimal application of modern methods of physical rehabilitation (correction programs formation), based on diagnostic methodologies findings

Technical diagnostics of steam turbines

International Nuclear Information System (INIS)

Vlckova, B.; Drahy, J.

1987-01-01

This paper deals with practical experience in application of technical diagnostics methods to steam turbines, in particular using pedestal and shaft vibration measurements as well as estimation of bearing metal temperature and ultrasound emission signals. An estimation of effectiveness of the diagnostics methods used is given on the basis of experimental investigations made on a 30-MW turbine. (author)

Metabolomics for laboratory diagnostics.

Science.gov (United States)

Bujak, Renata; Struck-Lewicka, Wiktoria; Markuszewski, Michał J; Kaliszan, Roman

2015-09-10

Metabolomics is an emerging approach in a systems biology field. Due to continuous development in advanced analytical techniques and in bioinformatics, metabolomics has been extensively applied as a novel, holistic diagnostic tool in clinical and biomedical studies. Metabolome's measurement, as a chemical reflection of a current phenotype of a particular biological system, is nowadays frequently implemented to understand pathophysiological processes involved in disease progression as well as to search for new diagnostic or prognostic biomarkers of various organism's disorders. In this review, we discussed the research strategies and analytical platforms commonly applied in the metabolomics studies. The applications of the metabolomics in laboratory diagnostics in the last 5 years were also reviewed according to the type of biological sample used in the metabolome's analysis. We also discussed some limitations and further improvements which should be considered taking in mind potential applications of metabolomic research and practice. Copyright © 2014 Elsevier B.V. All rights reserved.

Diagnostics for PLX-alpha

Science.gov (United States)

Gilmore, Mark; Hsu, Scott

2015-11-01

The goal of the Plasma Liner eXperiment PLX-alpha at Los Alamos National Laboratory is to establish the viability of creating a spherically imploding plasma liner for MIF and HED applications, using a spherical array of supersonic plasma jets launched by innovative contoured-gap coaxial plasma guns. PLX- α experiments will focus in particular on establishing the ram pressure and uniformity scalings of partial and fully spherical plasma liners. In order to characterize these parameters experimentally, a suite of diagnostics is planned, including multi-camera fast imaging, a 16-channel visible interferometer (upgraded from 8 channels) with reconfigurable, fiber-coupled front end, and visible and VUV high-resolution and survey spectroscopy. Tomographic reconstruction and data fusion techniques will be used in conjunction with interferometry, imaging, and synthetic diagnostics from modeling to characterize liner uniformity in 3D. Diagnostic and data analysis design, implementation, and status will be presented. Supported by the Advanced Research Projects Agency - Energy - U.S. Department of Energy.

Antiprotozoan and Antiviral Activities of Non-Cytotoxic Truncated and Variant Analogues of Mussel Defensin

Directory of Open Access Journals (Sweden)

Philippe Roch

2004-01-01

Full Text Available We previously reported the crucial role displayed by loop 3 of defensin isolated from the Mediterranean mussel, Mytilus galloprovincialis, in antibacterial and antifungal activities. We now investigated antiprotozoan and antiviral activities of some previously reported fragments B, D, E, P and Q. Two fragments (D and P efficiently killed Trypanosoma brucei (ID50 4–12 μM and Leishmania major (ID50 12–45 μM in a time/dose-dependent manner. Killing of T. brucei started as early as 1 h after initiation of contact with fragment D and reached 55% mortality after 6 h. Killing was temperature dependent and a temperature of 4°C efficiently impaired the ability to kill T. brucei. Fragments bound to the entire external epithelium of T. brucei. Prevention of HIV-1 infestation was obtained only with fragments P and Q at 20 μM. Even if fragment P was active on both targets, the specificity of fragments D and Q suggest that antiprotozoan and antiviral activities are mediated by different mechanisms. Truncated sequences of mussel defensin, including amino acid replacement to maintain 3D structure and increased positive net charge, also possess antiprotozoan and antiviral capabilities. New alternative and/or complementary antibiotics can be derived from the vast reservoir of natural antimicrobial peptides (AMPs contained in marine invertebrates.

TUBERCULIN DIAGNOSTICS: TO BE OR NOT TO BE?

Directory of Open Access Journals (Sweden)

N. M. Koretskaya

2013-01-01

Full Text Available Tuberculin diagnostics — is a diagnostic method of detection of specific sensitization to Mycobactrerium tuberculosis (MBT. It is used as a specific test during mass population screening on tuberculosis (mass tuberculin diagnostics and for individual examinations (individual tuberculin diagnostics. The aims of the mass diagnostics are: revealing of the patients contaminated with MBT for the first time; revealing of the patients with hyperergic and increasing reactions to tuberculin; selection of the population for vaccination against tuberculosis with weakened BCG vaccine in infants older than 2 months of life who had not been vaccinated after birth, as well for re-vaccination with BCG vaccine; early diagnostics of tuberculosis in children and adolescents; determination of epidemiological characteristics of tuberculosis (population contamination with MBT, yearly risk of contamination with MBT. On mass tuberculin diagnostics it is used only the united intradermal tuberculin Mantoux test with 2 tuberculin units (TU of purified tuberculin in standard solution (prepared form. In the article the author discusses questions of tuberculosis diagnostics in children and adolescents, lists indications to mass tuberculin diagnostics with Mantoux test with 2 TU PPD and test with recombinant tuberculosis allergen. Advantages of both methods, which should be used in order to increase efficacy of tuberculosis diagnostics among children population, are described. It was concluded that switch to the mass screening of tuberculosis with the means of recombinant tuberculosis allergen is not rational under current conditions. The appropriateness of 2-steps examination (necessity of test with recombinant tuberculosis allergen after receiving a positive result of Mantoux test with 2 TU PPD is explained. 

The ITER bolometer diagnostic: Status and plans

International Nuclear Information System (INIS)

Meister, H.; Giannone, L.; Horton, L. D.; Raupp, G.; Zeidner, W.; Grunda, G.; Kalvin, S.; Fischer, U.; Serikov, A.; Stickel, S.; Reichle, R.

2008-01-01

A consortium consisting of four EURATOM Associations has been set up to develop the project plan for the full development of the ITER bolometer diagnostic and to continue urgent R and D activities. An overview of the current status is given, including detector development, line-of-sight optimization, performance analysis as well as the design of the diagnostic components and their integration in ITER. This is complemented by the presentation of plans for future activities required to successfully implement the bolometer diagnostic, ranging from the detector development over diagnostic design and prototype testing to RH tools for calibration.

The ITER bolometer diagnostic: Status and plansa)

Science.gov (United States)

Meister, H.; Giannone, L.; Horton, L. D.; Raupp, G.; Zeidner, W.; Grunda, G.; Kalvin, S.; Fischer, U.; Serikov, A.; Stickel, S.; Reichle, R.

2008-10-01

A consortium consisting of four EURATOM Associations has been set up to develop the project plan for the full development of the ITER bolometer diagnostic and to continue urgent R&D activities. An overview of the current status is given, including detector development, line-of-sight optimization, performance analysis as well as the design of the diagnostic components and their integration in ITER. This is complemented by the presentation of plans for future activities required to successfully implement the bolometer diagnostic, ranging from the detector development over diagnostic design and prototype testing to RH tools for calibration.

Pediatric radiological diagnostics in suspected child abuse

International Nuclear Information System (INIS)

Erfurt, C.; Schmidt, U.; Hahn, G.; Roesner, D.

2009-01-01

Advanced and specialized radiological diagnostics are essential in the case of clinical suspicion of pediatric injuries to the head, thorax, abdomen, and extremities when there is no case history or when ''battered child syndrome'' is assumed on the basis of inadequate trauma. In particular, the aim of this sophisticated diagnostic procedure is the detection of lesions of the central nervous system (CNS) in order to initiate prompt medical treatment. If diagnostic imaging shows typical findings of child abuse, accurate documented evidence of the diagnostic results is required to prevent further endangerment of the child's welfare. (orig.) [de

The indication area of a diagnostic test. Part I--discounting gain and loss in diagnostic certainty

NARCIS (Netherlands)

Stalpers, Lukas J. A.; Nelemans, Patty J.; Geurts, Sandra M. E.; Jansen, Erik; de Boer, Peter; Verbeek, André L. M.

2015-01-01

Test performance is conventionally expressed by gain in diagnostic certainty. We propose net diagnostic gain and indication area as more appropriate measures of test performance; then, the loss in certainty due to misclassification and the information of "no test" would be performed are taken into

National NIF Diagnostic Program Interim Management Plan

International Nuclear Information System (INIS)

Warner, B

2002-01-01

The National Ignition Facility (NIF) has the mission of supporting Stockpile Stewardship and Basic Science research in high-energy-density plasmas. To execute those missions, the facility must provide diagnostic instrumentation capable of observing and resolving in time events and radiation emissions characteristic of the plasmas of interest. The diagnostic instrumentation must conform to high standards of operability and reliability within the NIF environment. These exacting standards, together with the facility mission of supporting a diverse user base, has led to the need for a central organization charged with delivering diagnostic capability to the NIF. The National NIF Diagnostics Program (NNDP) has been set up under the aegis of the NIF Director to provide that organization authority and accountability to the wide user community for NIF. The funds necessary to perform the work of developing diagnostics for NIF will be allocated from the National NIF Diagnostics Program to the participating laboratories and organizations. The participating laboratories and organizations will design, build, and commission the diagnostics for NIF. Restricted availability of funding has had an adverse impact, unforeseen at the time of the original decision to projectize NIF Core Diagnostics Systems and Cryogenic Target Handing Systems, on the planning and initiation of these efforts. The purpose of this document is to provide an interim project management plan describing the organizational structure and management processes currently in place for NIF Core Diagnostics Systems. Preparation of a Program Execution Plan for NIF Core Diagnostics Systems has been initiated and a current draft is provided as Attachment 1 to this document. The National NIF Diagnostics Program Interim Management Plan provides a summary of primary design criteria and functional requirements, current organizational structure, tracking and reporting procedures, and current planning estimates of project scope