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排序方式: 共有378条查询结果,搜索用时 15 毫秒
91.
Soraya Gaze Patrick Driguez Mark S. Pearson Tiago Mendes Denise L. Doolan Angela Trieu Donald P. McManus Geoffrey N. Gobert Maria Victoria Periago Rodrigo Correa Oliveira Fernanda C. Cardoso Guilherme Oliveira Rie Nakajima Al Jasinskas Chris Hung Li Liang Jozelyn Pablo Jeffrey M. Bethony Philip L. Felgner Alex Loukas 《PLoS pathogens》2014,10(3)
Schistosomiasis is a neglected tropical disease that is responsible for almost 300,000 deaths annually. Mass drug administration (MDA) is used worldwide for the control of schistosomiasis, but chemotherapy fails to prevent reinfection with schistosomes, so MDA alone is not sufficient to eliminate the disease, and a prophylactic vaccine is required. Herein, we take advantage of recent advances in systems biology and longitudinal studies in schistosomiasis endemic areas in Brazil to pilot an immunomics approach to the discovery of schistosomiasis vaccine antigens. We selected mostly surface-derived proteins, produced them using an in vitro rapid translation system and then printed them to generate the first protein microarray for a multi-cellular pathogen. Using well-established Brazilian cohorts of putatively resistant (PR) and chronically infected (CI) individuals stratified by the intensity of their S. mansoni infection, we probed arrays for IgG subclass and IgE responses to these antigens to detect antibody signatures that were reflective of protective vs. non-protective immune responses. Moreover, probing for IgE responses allowed us to identify antigens that might induce potentially deleterious hypersensitivity responses if used as subunit vaccines in endemic populations. Using multi-dimensional cluster analysis we showed that PR individuals mounted a distinct and robust IgG1 response to a small set of newly discovered and well-characterized surface (tegument) antigens in contrast to CI individuals who mounted strong IgE and IgG4 responses to many antigens. Herein, we show the utility of a vaccinomics approach that profiles antibody responses of resistant individuals in a high-throughput multiplex approach for the identification of several potentially protective and safe schistosomiasis vaccine antigens. 相似文献
92.
Jiang C Ataai M Ozuer A Krisky D Wechuck J Pornsuwan S Pourarian F Glorioso JC 《Biotechnology and bioengineering》2006,95(1):48-57
Metal catalyzed oxidation (MCO), which typically involves oxygen free radical generation, is an important pathway that leads to the deterioration of many biological molecules in solution. The occurrence of MCO in immobilized metal affinity chromatography (IMAC) systems and its potential for inactivating biological products has not been well recognized. In this study, we report the inactivation of herpes simplex virus type 1 (HSV-1) gene therapy vector on immobilized cobalt affinity chromatography. We observed that purification of KgBHAT, an HSV-1 mutant bearing cobalt affinity tags (HAT) on the surface, on an IDA-Co2+ column using crude supernatant as starting material resulted in signification loss in virus infectivity (<5% recovery). Electron spin resonance (ESR) revealed that the virus inactivation was caused by hydroxyl free radicals generated from the interactions between cellular impurities and the metal ions on the column. Inclusion of 20 mM ascorbate, a free radical scavenger, in the chromatography mobile phase effectively scavenged the hydroxyl radicals and dramatically augmented the infectivity recovery to 70%. This finding is the first demonstration of oxygen free radical-mediated biological inactivation in an actual IMAC purification and the way on how to effectively prevent it. 相似文献
93.
Nadia Naour Soraya Fellahi Jean‐François Renucci Christine Poitou Christine Rouault Arnaud Basdevant Anne Dutour Marie‐Christine Alessi Jean‐Philippe Bastard Karine Clément Michèle Guerre‐Millo 《Obesity (Silver Spring, Md.)》2009,17(12):2121-2126
Cystatin C, an endogenous inhibitor of cathepsin proteases has emerged as a biomarker of cardiovascular risk and reduced renal function. Epidemiological studies indicate that serum cystatin C increased in human obesity. Here, we evaluated the contribution of adipose tissue to this elevation, based on our previous observation that cystatin C is produced by in vitro differentiated human adipocytes. We measured serum cystatin C in 237 nonobese (age: 51 ± 0.8 years; BMI: 22.8 ± 0.11 kg/m2) and 248 obese subjects (age: 50 ± 0.8 years; BMI: 34.7 ± 0.29 kg/m2). Creatinine‐based estimated glomerular filtration rate (eGFR) was calculated to account for renal status. Cystatin C gene expression and secretion were determined on surgical adipose tissue biopsies in a distinct group of subjects. Serum cystatin C is elevated in obese subjects of both genders, independently of reduced eGFR. Cystatin C mRNA is expressed in subcutaneous and omental adipose tissue, at twice higher levels in nonadipose than in adipose cells. Gene expression and cystatin C release by adipose tissue explants increase two‐ to threefold in obesity. These data confirm elevation of serum cystatin C in human obesity and strongly argue for a contribution of increased production of cystatin C by enlarged adipose tissue. Because cystatin C has the potential to affect adipose tissue and vascular homeostasis through local and/or systemic inhibition of cathepsins, this study adds a new factor to the list of adipose tissue secreted bioactive molecules implicated in obesity and obesity‐linked complications. 相似文献
94.
Emanuela Di Campli Soraya Di Bartolomeo Rossella Grande Mara Di Giulio Luigina Cellini 《Current microbiology》2010,60(6):412-418
The aim of this work was to investigate the effects of exposure to extremely low-frequency electromagnetic fields (ELF-EMF)
both on biofilm formation and on mature biofilm of Helicobacter pylori. Bacterial cultures and 2-day-old biofilm of H. pylori ATCC 43629 were exposed to ELF-EMF (50 Hz frequency–1 mT intensity) for 2 days to assess their effect on the cell adhesion
and on the mature biofilm detachment, respectively. All the exposed cultures and the respective sham exposed controls were
studied for: the cell viability status, the cell morphological analysis, the biofilm mass measurement, the genotypic profile,
and the luxS and amiA gene expression. The ELF-EMF acted on the bacterial population during the biofilm formation displaying significant differences
in cell viability, as well as, in morphotypes measured by the prevalence of spiral forms (58.41%) in respect to the controls
(33.14%), whereas, on mature biofilm, no significant differences were found when compared to the controls. The measurement
of biofilm cell mass was significantly reduced in exposed cultures in both examined experimental conditions. No changes in
DNA patterns were recorded, whereas a modulation in amiA gene expression was detected. An exposure to ELF-EMF of H. pylori biofilm induces phenotypic changes on adhering bacteria and decreases the cell adhesion unbalancing the bacterial population
therefore reducing the H. pylori capability to protect itself. 相似文献
95.
Natállia A. Parreira Lizandra G. Magalhães Denis R. Morais Soraya C. Caixeta João P. B. de Sousa Jairo K. Bastos Wilson R. Cunha Márcio L. A. Silva N. P. D. Nanayakkara Vanderlei Rodrigues Ademar A. da Silva Filho 《化学与生物多样性》2010,7(4):993-1001
Baccharis dracunculifolia DC. (Asteraceae), popularly known as ‘alecrim do campo’, is a native plant from Brazil used in folk medicine as febrifuge, anti‐inflammatory, antiseptic, and to treat skin sores. Also, B. dracunculifolia is the most important plant source of the Brazilian green propolis, which is recognized for its antiseptic and antiprotozoal activities. This study aimed at investigating the in vitro antiprotozoal, schistosomicidal, and antimicrobial activities of the essential oil from the leaves of B. dracunculifolia. The essential oil was obtained by hydrodistillation and analyzed by GC and GC/MS, which allowed the identification of 14 compounds, mainly oxygenated sesquiterpenes, such as (E)‐nerolidol (33.51%) and spathulenol (16.24%). The essential oil showed activity against promastigote forms of Leishmania donovani, with IC50 values of 42 μg/ml. The essential oil displayed high activity in the schistosomicidal assay, since all pairs of Schistosoma mansoni adult worms were dead after incubation with the essential oil (10, 50, and 100 μg/ml). B. dracunculifolia essential oil was neither cytotoxic against Vero cells, nor active in the antimicrobial and antiplasmodial assays. 相似文献
96.
Delphine Depoix Sara Rute Marques David JP Ferguson Soraya Chaouch Thomas Duguet Robert E Sinden Philippe Grellier Linda Kohl 《Cellular microbiology》2020,22(3)
Sexual development is an essential phase in the Plasmodium life cycle, where male gametogenesis is an unusual and extraordinarily rapid process. It produces 8 haploid motile microgametes, from a microgametocyte within 15 minutes. Its unique achievement lies in linking the assembly of 8 axonemes in the cytoplasm to the three rounds of intranuclear genome replication, forming motile microgametes, which are expelled in a process called exflagellation. Surprisingly little is known about the actors involved in these processes. We are interested in kinesins, molecular motors that could play potential roles in male gametogenesis. We have undertaken a functional characterization in Plasmodium berghei of kinesin‐8B (PbKIN8B) expressed specifically in male gametocytes and gametes. By generating Pbkin8B‐gfp parasites, we show that PbKIN8B is specifically expressed during male gametogenesis and is associated with the axoneme. We created a ΔPbkin8B knockout cell line and analysed the consequences of the absence of PbKIN8B on male gametogenesis. We show that the ability to produce sexually differentiated gametocytes is not affected in ΔPbkin8B parasites and that the 3 rounds of genome replication occur normally. Nevertheless, the development to free motile microgametes is halted and the life cycle is interrupted in vivo. Ultrastructural analysis revealed that intranuclear mitoses are unaffected whereas cytoplasmic microtubules, although assembled in doublets and elongated, fail to assemble in the normal axonemal ‘9+2' structure and become motile. Absence of a functional axoneme prevented microgamete assembly and release from the microgametocyte, severely reducing infection of the mosquito vector. This is the first functional study of a kinesin involved in male gametogenesis. These results reveal a previously unknown role for PbKIN8B in male gametogenesis, providing new insights into Plasmodium flagellar formation. 相似文献
97.
Oliver MI Rodríguez C Bustos P Morín V Gutierrez S Montecino M Genevière AM Puchi M Imschenetzky M 《Journal of cellular biochemistry》2003,88(4):643-649
Three sets of histone variants are coexisting in the embryo at larval stages of sea urchin's development: the maternally inherited cleavage stage variants (CS) expressed during the two initial cleavage divisions, the early histone variants, which are recruited into embryonic chromatin from middle cleavage stages until hatching and the late variants, that are fundamentally expressed from blastula stage onward. Since the expression of the CS histones is confined to the initial cleavage stages, these variants represent a very minor proportion of the histones present in the plutei larvae, whereas the late histone variants are predominant. To determine the position of these CS in the embryonic territories, we have immunolocalized the CS histone variants in plutei larvas harvested 72 h post-fertilization. In parallel, we have pulse labeled the DNA replicated during the initial cleavage cycle with bromodeoxyuridine (BrdU) and its position was further determined in the plutei larvas by immunofluorescence. We have found that the CS histone variants were segregated to specific territories in the plutei. The position in which the CS histone variants were found to be segregated was consistent with the position in which the DNA molecules that were replicated during the initial cleavage divisions were localized. These results strongly suggest that a specification of embryonic nuclei occurs at the initial cleavage divisions which is determined by a chromatin organized by CS histone variants. 相似文献
98.
Abdel-Fattah YR Soliman NA Gaballa AA Sabry SA El-Diwany AI 《Acta microbiologica Polonica》2002,51(4):353-366
A novel thermophilic Bacillus sp. capable of producing lipase was locally isolated. Phylogenetic analysis based on 16SrDNA sequence revealed its close relationship to Bacillus thermoleovorans. Plackett-Burman experimental design was used to evaluate cultural conditions affecting lipase production process. Fifteen variables and four dummy variables were examined in the experimental design. Tween 80, temperature, olive oil, aeration, beef extract and inoculum age were found to be the highest positive significant variables affecting lipase activity, whereas pH and calcium chloride were the highest negative significant variables. Moreover, Tween 80, temperature and olive oil positively affected lipase specific activity. On the other hand, gum arabic, inoculum size and calcium chloride had the highest negative effect on lipase specific activity. This study would improve the further optimization steps on the bioprocess development track. 相似文献
99.
Ethanol-Induced Oxygen Radical Formation and Lipid Peroxidation in Rat Brain: Effect of Chronic Alcohol Consumption 总被引:9,自引:1,他引:8
Carmina Montoliu Soraya Vallés Jaime Renau-Piqueras Consuelo Guerri 《Journal of neurochemistry》1994,63(5):1855-1862
Abstract: The effect of chronic and in vitro ethanol exposure on brain oxygen radical formation and lipid peroxidation was analyzed. Ethanol induces a dose-dependent increase in lipid peroxidation in brain homogenates. The peroxidative effects of alcohol seem to be related to both cytochrome P450 and the ethanol-inducible form of cytochrome P450 (CYP2E1), because preincubation with metyrapone (an inhibitor of cytochrome P450) or with an antibody against CYP2E1 abolished the ethanol-increased lipid peroxidation. Using the formation of dichlorofluorescein, we also demonstrated that both in vitro and chronic alcohol exposure significantly enhanced the formation of oxygen radical species in synaptosomes. Chronic alcohol treatment also leads to an induction of cytochrome P450 (230%), NADPH cytochrome c reductase (180%), NADPH oxidation (184%), and CYP2E1 in brain microsomes. In addition, this treatment produced a decrease in the GSH/GSSG ratio in brain and significantly enhanced the levels of superoxide dismutase and catalase activities. This mechanism could be involved in the toxic effects of ethanol on brain and membrane alterations occurring after chronic ethanol intake. 相似文献
100.
Carolina V Morgante Patricia M Guimarães Andressa CQ Martins Ana CG Araújo Soraya CM Leal-Bertioli David J Bertioli Ana CM Brasileiro 《BMC research notes》2011,4(1):1-11