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31.
M Teruel F J Ruíz-Ruano J A Marchal A Sánchez J Cabrero J PM Camacho F Perfectti 《Heredity》2014,112(5):531-542
Wide arrays of repetitive DNA sequences form an important part of eukaryotic genomes. These repeats appear to evolve as coherent families, where repeats within a family are more similar to each other than to other orthologous representatives in related species. The continuous homogenization of repeats, through selective and non-selective processes, is termed concerted evolution. Ascertaining the level of variation between repeats is crucial to determining which evolutionary model best explains the homogenization observed for these sequences. Here, for the grasshopper Eyprepocnemis plorans, we present the analysis of intragenomic diversity for two repetitive DNA sequences (a satellite DNA (satDNA) and the 45S rDNA) resulting from the independent microdissection of several chromosomes. Our results show different homogenization patterns for these two kinds of paralogous DNA sequences, with a high between-chromosome structure for rDNA but no structure at all for the satDNA. This difference is puzzling, considering the adjacent localization of the two repetitive DNAs on paracentromeric regions in most chromosomes. The disparate homogenization patterns detected for these two repetitive DNA sequences suggest that several processes participate in the concerted evolution in E. plorans, and that these mechanisms might not work as genome-wide processes but rather as sequence-specific ones. 相似文献
32.
Jacky Woo Michel PM Vierboom Hakju Kwon Debra Chao Shiming Ye Jianmin Li Karen Lin Irene Tang Nicole A Belmar Taymar Hartman Elia Breedveld Vladimir Vexler Bert A ‘t Hart Debbie A Law Gary C Starling 《Arthritis research & therapy》2013,15(6):R207
Introduction
Targeting the CD20 antigen has been a successful therapeutic intervention in the treatment of rheumatoid arthritis (RA). However, in some patients with an inadequate response to anti-CD20 therapy, a persistence of CD20- plasmablasts is noted. The strong expression of CD319 on CD20- plasmablast and plasma cell populations in RA synovium led to the investigation of the potential of CD319 as a therapeutic target.Methods
PDL241, a novel humanized IgG1 monoclonal antibody (mAb) to CD319, was generated and examined for its ability to inhibit immunoglobulin production from plasmablasts and plasma cells generated from peripheral blood mononuclear cells (PBMC) in the presence and absence of RA synovial fibroblasts (RA-SF). The in vivo activity of PDL241 was determined in a human PBMC transfer into NOD scid IL-2 gamma chain knockout (NSG) mouse model. Finally, the ability of PDL241 to ameliorate experimental arthritis was evaluated in a collagen-induced arthritis (CIA) model in rhesus monkeys.Results
PDL241 bound to plasmablasts and plasma cells but not naïve B cells. Consistent with the binding profile, PDL241 inhibited the production of IgM from in vitro PBMC cultures by the depletion of CD319+ plasmablasts and plasma cells but not B cells. The activity of PDL241 was dependent on an intact Fc portion of the IgG1 and mediated predominantly by natural killer cells. Inhibition of IgM production was also observed in the human PBMC transfer to NSG mouse model. Treatment of rhesus monkeys in a CIA model with PDL241 led to a significant inhibition of anti-collagen IgG and IgM antibodies. A beneficial effect on joint related parameters, including bone remodeling, histopathology, and joint swelling was also observed.Conclusions
The activity of PDL241 in both in vitro and in vivo models highlights the potential of CD319 as a therapeutic target in RA. 相似文献33.
Fabrizio Villa Ryo Fujisawa Johanna Ainsworth Kohei Nishimura Michael LieALing Georges Lacaud Karim PM Labib 《EMBO reports》2021,22(3)
The eukaryotic replisome is disassembled in each cell cycle, dependent upon ubiquitylation of the CMG helicase. Studies of Saccharomyces cerevisiae, Caenorhabditis elegans and Xenopus laevis have revealed surprising evolutionary diversity in the ubiquitin ligases that control CMG ubiquitylation, but regulated disassembly of the mammalian replisome has yet to be explored. Here, we describe a model system for studying the ubiquitylation and chromatin extraction of the mammalian CMG replisome, based on mouse embryonic stem cells. We show that the ubiquitin ligase CUL2LRR1 is required for ubiquitylation of the CMG‐MCM7 subunit during S‐phase, leading to disassembly by the p97 ATPase. Moreover, a second pathway of CMG disassembly is activated during mitosis, dependent upon the TRAIP ubiquitin ligase that is mutated in primordial dwarfism and mis‐regulated in various cancers. These findings indicate that replisome disassembly in diverse metazoa is regulated by a conserved pair of ubiquitin ligases, distinct from those present in other eukaryotes. 相似文献
34.
Food Biophysics - Engineered biocatalyst and its desired products using nanotechnology has intensified the research in food industries. Zinc oxide (ZnO) nanosheet is designed and prepared; the... 相似文献
35.
Jo Moore Stephen AC Hawkins Anthony R Austin Timm Konold Robert B Green Ian W Blamire Ian Dexter Michael J Stack Melanie J Chaplin Jan PM Langeveld Marion M Simmons Yvonne I Spencer Paul R Webb Michael Dawson Gerald AH Wells 《BMC research notes》2011,4(1):1-13
Background
Escherichia coli O157:H7 is the most common serovar of enterohemorrhagic E. coli associated with serious human disease outbreaks. Cattle are the main reservoir with E. coli O157:H7 inducing hemorrhagic enteritis in persistent shedding beef cattle, however little is known about how this pathogen affects cattle health. Jejunal Hemorrhage Syndrome (JHS) has unclear etiology but the pathology is similar to that described for E. coli O157:H7 challenged beef cattle suggestive that E. coli O157:H7 could be involved. There are no effective treatments for JHS however new approaches to managing pathogen issues in livestock using prebiotics and probiotics are gaining support. The first objective of the current study was to characterize pathogen colonization in hemorrhaged jejunum of dairy cattle during natural JHS outbreaks. The second objective was to confirm the association of mycotoxigenic fungi in feeds with the development of JHS and also to identify the presence of potential mycotoxins. The third objective was to determine the impact of a prebiotic, Celmanax?, or probiotic, Dairyman's Choice? paste, on the cytotoxicity associated with feed extracts in vitro. The fourth objective was to determine the impact of a prebiotic or a probiotic on E. coli O157:H7 colonization of mucosal explants and a bovine colonic cell line in vitro. The final objective was to determine if prebiotic and probiotic feed additives could modify the symptoms that preceded JHS losses and the development of new JHS cases.Findings
Dairy cattle developed JHS after consuming feed containing several types of mycotoxigenic fungi including Fusarium culmorum, F. poae, F. verticillioides, F. sporotrichioides, Aspergillus flavus, Penicillium roqueforti, P. crustosum, P. paneum and P. citrinum. Mixtures of Shiga toxin - producing Escherichia coli (STEC) colonized the mucosa in the hemorrhaged tissues of the cattle and no other pathogen was identified. The STECs expressed Stx1 and Stx2, but more significantly, Stxs were also present in the blood clot blocking the jejunum. Mycotoxin analysis of the corn crop confirmed the presence of fumonisin, NIV, ZEAR, DON, 15-ADON, 3-ADON, NEO, DAS, HT-2 and T-2. Feed extracts were toxic to enterocytes and 0.1% Celmanax? removed the cytotoxicity in vitro. There was no effect of Dairyman's Choice? paste on feed-extract activity in vitro. Fumonisin, T-2, ZEAR and DON were toxic to bovine cells and 0.1% Celmanax? removed the cytotoxicity in vitro. Celmanax? also directly decreased E. coli O157:H7 colonization of mucosal explants and a colonic cell line in a dose-dependent manner. There was no effect of Dairyman's Choice? paste on E. coli O157:H7 colonization in vitro. The inclusion of the prebiotic and probiotic in the feed was associated with a decline in disease.Conclusion
The current study confirmed an association between mycotoxigenic fungi in the feed and the development of JHS in cattle. This association was further expanded to include mycotoxins in the feed and mixtures of STECs colonizing the severely hemorrhaged tissues. Future studies should examine the extent of involvement of the different STEC in the infection process. The prebiotic, Celmanax?, acted as an anti-adhesive for STEC colonization and a mycotoxin binder in vitro. Future studies should determine the extent of involvement of the prebiotic in altering disease. 相似文献36.
37.
Ana PM Oliveira Rosana Gentile Arnaldo Maldonado Júnior Eduardo J Lopes Torres Silvana C Thiengo 《Memórias do Instituto Oswaldo Cruz》2015,110(6):739-744
The aim of this study was to analyse the infection dynamics ofAngiostrongylus
cantonensis in its possible intermediate hosts over two years in an urban
area in the state of Rio de Janeiro where the presence ofA.
cantonensis had been previously recorded in molluscs. Four of the seven
mollusc species found in the study were exotic.Bradybaena similaris
was the most abundant, followed byAchatina fulica,
Streptaxis sp., Subulina octona,
Bulimulus tenuissimus, Sarasinula linguaeformis
and Leptinaria unilamellata. Only A. fulica
and B. similaris were parasitised by A.
cantonensis and both presented co-infection with other helminths. The
prevalence of A. cantonensisin A. fulica was more
than 50% throughout the study. There was an inverse correlation between the
population size ofA. fulica and the prevalence of A.
cantonensis and abundance of the latter was negatively related to
rainfall. The overall prevalence of A. cantonensis in B.
similariswas 24.6%. A. fulica was the most important
intermediary host of A. cantonensis in the studied area
andB. similaris was secondary in importance for A.
cantonensis transmission dynamics. 相似文献
38.
Edgard B. Ngoungou Devender Bhalla Amandine Nzoghe Marie-Laure Dardé Pierre-Marie Preux 《PLoS neglected tropical diseases》2015,9(2)
Background
Toxoplasmosis is an important, widespread, parasitic infection caused by Toxoplasma gondii. The chronic infection in immunocompetent patients, usually considered as asymptomatic, is now suspected to be a risk factor for various neurological disorders, including epilepsy. We aimed to conduct a systematic review and meta-analysis of the available literature to estimate the risk of epilepsy due to toxoplasmosis.Methods
A systematic literature search was conducted of several databases and journals to identify studies published in English or French, without date restriction, which looked at toxoplasmosis (as exposure) and epilepsy (as disease) and met certain other inclusion criteria. The search was based on keywords and suitable combinations in English and French. Fixed and random effects models were used to determine odds ratios, and statistical significance was set at 5.0%.Principal findings
Six studies were identified, with an estimated total of 2888 subjects, of whom 1280 had epilepsy (477 positive for toxoplasmosis) and 1608 did not (503 positive for toxoplasmosis). The common odds ratio (calculated) by random effects model was 2.25 (95% CI 1.27–3.9), p = 0.005.Conclusions
Despite the limited number of studies, and a lack of high-quality data, toxoplasmosis should continue to be regarded as an epilepsy risk factor. More and better studies are needed to determine the real impact of this parasite on the occurrence of epilepsy. 相似文献39.
Yessito Corine Nadège Houehanou Philippe Lacroix Gbedecon Carmelle Mizehoun Pierre-Marie Preux Benoit Marin Dismand Stephan Houinato 《PloS one》2015,10(5)
ObjectiveTo describe and compare the prevalences of CVRF in urban and rural populations of Benin.MethodsSubjects were drawn from participants in the Benin Steps survey, a nationwide cross-sectional study conducted in 2008 using the World Health Organisation (WHO) stepwise approach to surveillance of chronic disease risk factors. Subjects aged above 24 and below 65 years were recruited using a five-stage random sampling process within households. Sociodemographic data, behavioral data along with medical history of high blood pressure and diabetes mellitus were collected in Step 1. Anthropometric parameters and blood pressure were measured in Step 2. Blood glucose and cholesterol levels were measured in Step 3. CVRF were defined according to WHO criteria. The prevalences of CVRF were assessed and the relationships between each CVRF and the area of residence (urban or rural), were evaluated using multivariable logistic regression models.ResultsOf the 6762 subjects included in the study, 2271 were from urban areas and 4491 were from rural areas. High blood pressure was more prevalent in urban than in rural areas, 29.9% (95% confidence intervals (95% CI): 27.4, 32.5) and 27.5% (95% CI: 25.6, 29.5) respectively, p = 0.001 (p-value after adjustment for age and gender). Obesity was more prevalent in urban than in rural areas, 16.4% (95% CI: 14.4, 18.4) and 5.9% (95% CI: 5.1, 6.7), p<0.001. Diabetes was more prevalent in urban than in rural areas, 3.3% (95% CI: 2.1, 4.5) and 1.8% (95% CI: 1.2, 2.4), p = 0.004. Conversely, daily tobacco smoking was more prevalent in rural than in urban areas, 9.3% (95% CI: 8.1, 10.4) and 4.3% (95% CI: 3.1, 5.6), p<0.001. No differences in raised blood cholesterol were noted between the two groups.ConclusionAccording to our data, CVRF are prevalent among adults in Benin, and variations between rural and urban populations are significant. It may be useful to take account of the heterogeneity in the prevalence of CVRF when planning and implementing preventive interventions. 相似文献
40.
Mirjafari H Farragher TM Verstappen SM Yates A Bunn D Marshall T Lunt M Symmons DP Bruce IN 《Arthritis research & therapy》2011,13(5):R159