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Peloso Ede F Vitor SC Ribeiro LH Piñeyro MD Robello C Gadelha FR 《Journal of bioenergetics and biomembranes》2011,43(4):419-424
Trypanosoma cruzi cytosolic (TcCPx) and mitochondrial tryparedoxin peroxidase (TcMPx) play a fundamental role in H2O2 detoxification. Herein, mitochondrial bioenergetics was evaluated in cells that overexpressed TcCPx (CPx) and TcMPx (MPx)
and in pTEX. In MPx, a higher expression was observed for TcCPx, and the same correlation was true for CPx. Differences in
H2O2 release among the overexpressing cells were detected when the mitochondrial respiratory chain was inhibited using antimycin
A or thenoyltrifluoroacetone. MPx had higher O2 consumption rates than pTEX and CPx, especially in the presence of oligomycin. In all of the cells, the mitochondrial membrane
potential and the ATP levels were similar. Because of the mild uncoupling that was observed in MPx, the presence or induction
of a proton transporter in the mitochondrial membrane is suggested when TcMPx is expressed at higher levels. Our results show
a possible interplay between the cytosolic and mitochondrial antioxidant systems in a trypanosomatid. 相似文献
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Discovery-based science education: functional genomic dissection in Drosophila by undergraduate researchers 下载免费PDF全文
Chen J Call GB Beyer E Bui C Cespedes A Chan A Chan J Chan S Chhabra A Dang P Deravanesian A Hermogeno B Jen J Kim E Lee E Lewis G Marshall J Regalia K Shadpour F Shemmassian A Spivey K Wells M Wu J Yamauchi Y Yavari A Abrams A Abramson A Amado L Anderson J Bashour K Bibikova E Bookatz A Brewer S Buu N Calvillo S Cao J Chang A Chang D Chang Y Chen Y Choi J Chou J Datta S Davarifar A Desai P Fabrikant J Farnad S Fu K Garcia E Garrone N Gasparyan S Gayda P Goffstein C Gonzalez C Guirguis M 《PLoS biology》2005,3(2):e59
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Christian A. Ganoza Michael A. Matthias Mayuko Saito Manuel Cespedes Eduardo Gotuzzo Joseph M. Vinetz 《PLoS neglected tropical diseases》2010,4(2)
Background
Renal carriage and shedding of leptospires is characteristic of carrier or maintenance animal hosts. Sporadic reports indicate that after infection, humans may excrete leptospires for extended periods. We hypothesized that, like mammalian reservoir hosts, humans develop asymptomatic leptospiruria in settings of high disease transmission such as the Peruvian Amazon.Methodology/Principal Findings
Using a cross-sectional study design, we used a combination of epidemiological data, serology and molecular detection of the leptospiral 16S rRNA gene to identify asymptomatic urinary shedders of Leptospira. Approximately one-third of the 314 asymptomatic participants had circulating anti-leptospiral antibodies. Among enrolled participants, 189/314 (59%) had evidence of recent infection (microscopic agglutination test (MAT0 ≥1∶800 or ELISA IgM-positive or both). The proportion of MAT-positive and high MAT-titer (≥1∶800) persons was higher in men than women (p = 0.006). Among these people, 13/314 (4.1%) had Leptospira DNA-positive urine samples. Of these, the 16S rRNA gene from 10 samples was able to be sequenced. The urine-derived species clustered within both pathogenic (n = 6) and intermediate clades of Leptospira (n = 4). All of the thirteen participants with leptospiral DNA in urine were women. The median age of the DNA-positive group was older compared to the negative group (p≤0.05). A group of asymptomatic participants (“long-term asymptomatic individuals,” 102/341 (32.5%) of enrolled individuals) without serological evidence of recent infection was identified; within this group, 6/102 (5.9%) excreted pathogenic and intermediate-pathogenic Leptospira (75–229 bacteria/mL of urine).Conclusions/Significance
Asymptomatic renal colonization of leptospires in a region of high disease transmission is common, including among people without serological or clinical evidence of recent infection. Both pathogenic and intermediate Leptospira can persist as renal colonization in humans. The pathogenic significance of this finding remains to be explored but is of fundamental biological significance. 相似文献25.
Paulo C Carvalho Juliana SG Fischer Emily I Chen Gilberto B Domont Maria GC Carvalho Wim M Degrave John R Yates III Valmir C Barbosa 《Proteome science》2009,7(1):6-11
Background
Spectral counting is a shotgun proteomics approach comprising the identification and relative quantitation of thousands of proteins in complex mixtures. However, this strategy generates bewildering amounts of data whose biological interpretation is a challenge. 相似文献26.
Genomewide clonal analysis of lethal mutations in the Drosophila melanogaster eye: comparison of the X chromosome and autosomes 总被引:1,自引:0,他引:1 下载免费PDF全文
Call GB Olson JM Chen J Villarasa N Ngo KT Yabroff AM Cokus S Pellegrini M Bibikova E Bui C Cespedes A Chan C Chan S Cheema AK Chhabra A Chitsazzadeh V Do MT Fang QA Folick A Goodstein GL Huang CR Hung T Kim E Kim W Kim Y Kohan E Kuoy E Kwak R Lee E Lee J Lin H Liu HC Moroz T Prasad T Prashad SL Patananan AN Rangel A Rosselli D Sidhu S Sitz D Taber CE Tan J Topp K Tran P Tran QM Unkovic M Wells M Wickland J Yackle K Yavari A Zaretsky JM Allen CM Alli L An J Anwar A Arevalo S Ayoub D Badal SS 《Genetics》2007,177(2):689-697
Using a large consortium of undergraduate students in an organized program at the University of California, Los Angeles (UCLA), we have undertaken a functional genomic screen in the Drosophila eye. In addition to the educational value of discovery-based learning, this article presents the first comprehensive genomewide analysis of essential genes involved in eye development. The data reveal the surprising result that the X chromosome has almost twice the frequency of essential genes involved in eye development as that found on the autosomes. 相似文献
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Joy S. Tea Albert Cespedes Daniel Dawson Utpal Banerjee Gerald B. Call 《Journal of visualized experiments : JoVE》2014,(93)
The Drosophila melanogaster eye disc is a powerful system that can be used to study many different biological processes. It contains approximately 800 separate eye units, termed ommatidia1. Each ommatidium contains eight neuronal photoreceptors that develop from undifferentiated cells following the passage of the morphogenetic furrow in the third larval instar2. Following the sequential differentiation of the photoreceptors, non-neuronal cells develop, including cone and pigment cells, along with mechanosensory bristle cells3. Final differentiation processes, including the structured arrangement of all the ommatidial cell types, programmed cell death of undifferentiated cell types and rhodopsin expression, occurs through the pupal phase4-7. This technique focuses on manipulating the pupal eye disc, providing insight and instruction on how to dissect the eye disc during the pupal phase, which is inherently more difficult to perform than the commonly dissected third instar eye disc. This technique also provides details on immunostaining to allow the visualization of various proteins and other cell components. 相似文献
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Molecular localization of a redox-modulated process regulating plant mitochondrial electron transport 总被引:8,自引:0,他引:8 下载免费PDF全文
Using in organellar assays, we found that significant tobacco alternative oxidase (AOX) activity is dependent on both reduction of a putative regulatory disulfide bond and the presence of pyruvate, which may interact with a Cys sulfhydryl. This redox modulation and pyruvate activation thus may be important in determining the partitioning of electrons to AOX in vivo. To investigate these regulatory mechanisms, we generated tobacco plants expressing mutated AOX proteins. Mutation of the most N-terminal Cys residue (Cys-126) to an Ala residue produced an AOX that could not be converted to the disulfide-linked form, thus identifying this Cys residue as being responsible for redox modulation. Although this mutation might be expected to produce an AOX with constitutive high activity in the presence of pyruvate, we found it to have minimal in organellar activity in the presence of pyruvate. Nonetheless, the Cys-126 mutation did not appear to have compromised the catalytic function of AOX, given that cells expressing the protein displayed high rates of cyanide-resistant respiration in vivo. The striking difference between in vivo and in organellar results suggests that an additional mechanism(s), as yet unidentified by in organellar assays, may promote activity in vivo. Mutation of the Cys residue nearest the presumptive active site (Cys-176) to an Ala residue did not prevent disulfide bond formation or affect the ability of AOX to be stimulated by pyruvate, indicating that this Cys residue is involved in neither redox modulation nor pyruvate activation. 相似文献
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