Base de dados : MEDLINE
Pesquisa : B01.043.075.189.250.150 [Categoria DeCS]
Referências encontradas : 7 [refinar]
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  1 / 7 MEDLINE  
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PMID:22366436
Autor:Heinz E; Lithgow T
Endereço:Department of Biochemistry & Molecular Biology, Monash University, Clayton Campus, Melbourne 3800, Australia. Eva.Heinz@monash.edu
Título:Back to basics: a revealing secondary reduction of the mitochondrial protein import pathway in diverse intracellular parasites.
Fonte:Biochim Biophys Acta; 1833(2):295-303, 2013 Feb.
ISSN:0006-3002
País de publicação:Netherlands
Idioma:eng
Resumo:Mitochondria are present in all eukaryotes, but remodeling of their metabolic contribution has in some cases left them almost unrecognizable and they are referred to as mitochondria-like organelles, hydrogenosomes or, in the case where evolution has led to a great deal of simplification, as mitosomes. Mitochondria rely on the import of proteins encoded in the nucleus and the protein import machinery has been investigated in detail in yeast: several sophisticated molecular machines act in concert to import substrate proteins across the outer mitochondrial membrane and deliver them to a precise sub-mitochondrial compartment. Because these machines are so sophisticated, it has been a major challenge to conceptualize the first phase of their evolution. Here we review recent studies on the protein import pathway in parasitic species that have mitosomes: in the course of their evolution for highly specialized niches these parasites, particularly Cryptosporidia and Microsporidia, have secondarily lost numerous protein functions, in accordance with the evolution of their genomes towards a minimal size. Microsporidia are related to fungi, Cryptosporidia are apicomplexans and kin to the malaria parasite Plasmodium; and this great phylogenetic distance makes it remarkable that Microsporidia and Cryptosporidia have independently evolved skeletal protein import pathways that are almost identical. We suggest that the skeletal pathway reflects the protein import machinery of the first eukaryotes, and defines the essential roles of the core elements of the mitochondrial protein import machinery. This article is part of a Special Issue entitled: Protein Import and Quality Control in Mitochondria and Plastids.
Tipo de publicação: JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T; REVIEW
Nome de substância:0 (Fungal Proteins); 0 (Mitochondrial Proteins)


  2 / 7 MEDLINE  
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PMID:19889527
Autor:Houssin T; Follet J; Follet A; Dei-Cas E; Senez V
Endereço:University Lille Nord de France, Lille, France. timothee.houssin@isen.iemn.univ-lille1.fr
Título:Label-free analysis of water-polluting parasite by electrochemical impedance spectroscopy.
Fonte:Biosens Bioelectron; 25(5):1122-9, 2010 Jan 15.
ISSN:1873-4235
País de publicação:England
Idioma:eng
Resumo:A new, label-free, real time and non-invasive method is presented to detect the presence of infectious parasites in water and determine accurately their concentration by electrochemical impedance spectroscopy (E.I.S.) using interdigitated microelectrode array. Cryptosporidium parvum was taken as model. Buffer influence on parasite detection was investigated by comparing parasites suspended in purified water versus phosphate buffer saline. It was shown that a low conductive buffer is required for parasite detection. Different suspensions of C. parvum oocysts were measured in purified water. By fitting resulting electrochemical impedance spectrums with an equivalent electrical circuit, solution conductance was extracted. Conductance increased linearly with C. parvum oocyst concentration. The reasons of conductance modification induced by parasite presence are discussed. Cell constant was calculated for circular interdigitated electrode arrays. Thus sample conductivity can be obtained from raw impedance spectrums and it was established that water conductivity was proportional to C. parvum oocyst amount. This relationship can be expressed by: sigma (Sm(-1))=2.88228x10(-6)xC (oocysts/microl)+1.64565x10(-4) with R(2)=0.99. In this way, E.I.S. can be used as a rapid alternative to current parasite counting procedures which consists in fluorescent staining and microscopic observation. The distinction between dead and living parasites by E.I.S. was also approached. Between 10 kHz and 100 kHz, electrochemical impedance showed a difference of 15% between dead and living oocysts.
Tipo de publicação: EVALUATION STUDIES; JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
Nome de substância:0 (Water Pollutants)


  3 / 7 MEDLINE  
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PMID:16880067
Autor:Huang DB; White AC
Endereço:Division of Infectious Diseases, Department of Medicine, Baylor College of Medicine, One Baylor Plaza, 535EE, Houston, TX 77030, USA.
Título:An updated review on Cryptosporidium and Giardia.
Fonte:Gastroenterol Clin North Am; 35(2):291-314, viii, 2006 Jun.
ISSN:0889-8553
País de publicação:United States
Idioma:eng
Resumo:Cryptosporidium and Giardia are two of the most commonly occurring enteric protozoans. They are responsible for diarrheal diseases that may lead to nutritional deficiencies and significant morbidity and mortality, especially among children in developing countries and patients who have immune defects. Both are difficult to diagnose with microscopic techniques. This article provides an updated review of the epidemiology, pathogenesis, clinical manifestations, and treatment of Cryptosporidium and Giardia.
Tipo de publicação: JOURNAL ARTICLE; REVIEW


  4 / 7 MEDLINE  
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PMID:16779145
Autor:Wagner MM; Wallstrom GL; Onisko A
Endereço:RODS Laboratory, Center for Biomedical Informatics, University of Pittsburgh, USA.
Título:Issue a boil-water advisory or wait for definitive information? A decision analysis.
Fonte:AMIA Annu Symp Proc; :774-8, 2005.
ISSN:1942-597X
País de publicação:United States
Idioma:eng
Resumo:OBJECTIVE: Study the decision to issue a boil-water advisory in response to a spike in sales of diarrhea remedies or wait 72 hours for the results of definitive testing of water and people. METHODS: Decision analysis. RESULTS: In the base-case analysis, the optimal decision is test-and-wait. If the cost of issuing a boil-water advisory is less than 13.92 cents per person per day, the optimal decision is to issue the boil-water advisory immediately. CONCLUSIONS: Decisions based on surveillance data that are suggestive but not conclusive about the existence of a disease outbreak can be modeled.
Tipo de publicação: JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T; RESEARCH SUPPORT, U.S. GOV'T, NON-P.H.S.
Nome de substância:0 (Antidiarrheals); 0 (Nonprescription Drugs); 059QF0KO0R (Water)


  5 / 7 MEDLINE  
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PMID:14966126
Autor:Atreya CE; Anderson KS
Endereço:Department of Pharmacology, Yale University School of Medicine, New Haven, Connecticut 06520, USA.
Título:Kinetic characterization of bifunctional thymidylate synthase-dihydrofolate reductase (TS-DHFR) from Cryptosporidium hominis: a paradigm shift for ts activity and channeling behavior.
Fonte:J Biol Chem; 279(18):18314-22, 2004 Apr 30.
ISSN:0021-9258
País de publicação:United States
Idioma:eng
Resumo:This study presents a kinetic characterization of the recently crystallized bifunctional thymidylate synthasedihydrofolate reductase (TS-DHFR) enzyme from the apicomplexa parasite, Cryptosporidium hominis. Our study focuses on determination of the C. hominis TS-DHFR kinetic mechanism, substrate channeling behavior, and domain-domain communication. Unexpectedly, the unique mechanistic features of C. hominis TS-DHFR involve the highly conserved TS domain. At 45 s(-) (1), C. hominis TS activity is 10-40-fold faster than other TS enzymes studied and a new kinetic mechanism was required to simulate C. hominis TS behavior. A large accumulation of dihydrofolate produced at TS and a lag in product formation at DHFR were observed. These observations make C. hominis TS-DHFR the first bifunctional TS-DHFR enzyme studied for which there is clear evidence against dihydrofolate substrate channeling. Furthermore, whereas with Leishmania major TS-DHFR there are multiple lines of evidence for domain-domain communication (ligand binding at one active site affecting activity of the other enzyme), no such effects were observed with C. hominis TS-DHFR.
Tipo de publicação: JOURNAL ARTICLE; RESEARCH SUPPORT, U.S. GOV'T, P.H.S.
Nome de substância:0 (Multienzyme Complexes); 0 (Protozoan Proteins); 0 (thymidylate synthase-dihydrofolate reductase); 4033-27-6 (dihydrofolate); 935E97BOY8 (Folic Acid); EC 1.5.1.3 (Tetrahydrofolate Dehydrogenase); EC 2.1.1.45 (Thymidylate Synthase)


  6 / 7 MEDLINE  
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PMID:15508784
Autor:Hassl A; Benyr G
Endereço:Department of Medical Parasitology, Clinical Institute of Hygiene and Medical Microbiology, University of Vienna, Vienna. andreas.hassl@univie.ac.at
Título:Hygienic evaluation of terraria inhabited by amphibians and reptiles: cryptosporidia, free-living amebas, salmonella.
Fonte:Wien Klin Wochenschr; 115 Suppl 3:68-71, 2003.
ISSN:0043-5325
País de publicação:Austria
Idioma:eng
Resumo:Amphibians and reptiles are popular pet animals in about 90.000 Austrian households despite their frequently debated capacity to transmit diseases associated with animal keeping. We studied the epidemiological significance of the triangle animal keeper, exotic pet animal, and feed mice by investigating the frequency of three intestinal infestations, caused by cryptosporidia, opportunistic free-living amebas and salmonella, in amphibians and reptiles living in a public vivarium. In addition to recording the first known occurrence of Naegleria australiensis in Austria, and of this species and of Acanthamoeba polyphaga in the feces of reptiles worldwide, we also detected a strong association between Salmonella subspecies I and captive reptiles and between S. sub-species III and free-living lizards. Thus, animal keeper, the exotic animals kept, and the feed mice may constitute an epidemiological pool for the interchange of these infectious agents. This new epidemiological situation may cause an increase of some opportunistic and exotic diseases such as reptile-borne salmonellosis. Despite the perceived benefits of keeping exotic animals in a household, the general public and especially those who have an immunodeficiency must be made aware of the danger of infectious diseases possibly being spread by their pets.
Tipo de publicação: COMPARATIVE STUDY; EVALUATION STUDIES; JOURNAL ARTICLE


  7 / 7 MEDLINE  
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PMID:12076630
Autor:Alvarez-Pellitero P; Sitjà-Bobadilla A
Endereço:Instituto de Acuicultura de Torre de la Sal (C.S.I.C.), Torre de la Sal, 12595 Ribera de Cabanes, Castellon, Spain.
Título:Cryptosporidium molnari n. sp. (Apicomplexa: Cryptosporidiidae) infecting two marine fish species, Sparus aurata L. and Dicentrarchus labrax L.
Fonte:Int J Parasitol; 32(8):1007-21, 2002 Jul.
ISSN:0020-7519
País de publicação:England
Idioma:eng
Resumo:Cryptosporidium molnari n. sp. is described from two teleost fish, the gilthead sea bream (Sparus aurata L.) and the European sea bass (Dicentrarchus labrax L.). The parasite was found mainly in the stomach epithelium and seldom in the intestine. Oocysts were almost spherical, with four naked sporozoites and a prominent residuum, and measured 3.23-5.45 x 3.02-5.04 (mean 4.72 x 4.47) microm in the type host, gilthead sea bream (shape index 1-1.17, mean 1.05). Sporulation was endogenous, as fully sporulated oocysts were found within the fish, both in the stomach epithelium and lumen, and in faeces. Oocysts and other stages of C. molnari fit most of the diagnostic features of the genus Cryptosporidium, but differ from hitherto described species, including piscine ones. All stages were located within a host contributed parasitophorous vacuole lined by a double host microvillar membrane. Merogonial and gamogonial stages appeared in the typical extracytoplasmic position, whereas oogonial and sporogonial stages were located deeply within the epithelium. Ultrastructural features, including the characteristic contact zone of the parasite with the host epithelial surface, were mostly coincident with those of other Cryptosporidium spp. Mitochondria were found in dividing meronts, merozoites, microgamonts and sporozoites. Pathological effects were more evident in gilthead sea bream, which also exhibited a clearly higher prevalence (24.4 versus 4.64% in sea bass). External clinical signs, consisting of whitish faeces, abdominal swelling and ascites, were rarely observed, in contrast with important histopathological damage. The wide zones of epithelium invaded by oogonial and sporogonial stages appeared necrotic, with abundant cell debris, and sloughing of epithelial cells, which detached to the lumen. No inflammation reaction was observed and the cellular reaction was limited to the cells involved in the engulfing of intraepithelial stages and debris, probably macrophages.
Tipo de publicação: JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T



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