2,318 research outputs found

    Test of a Novel Streptococcus pneumoniae Serotype 6C Type Specific Polyclonal Antiserum (Factor Antiserum 6d) and Characterisation of Serotype 6C Isolates in Denmark

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    <p>Abstract</p> <p>Background</p> <p>In 2007, Park <it>et al. </it>identified a novel serotype among <it>Streptococcus pneumoniae </it>serogroup 6 which they named serotype 6C. The aim of this study was to evaluate with the Neufeld test a novel <it>S. pneumoniae </it>serotype 6C type specific polyclonal antiserum. In addition, serotype 6C isolates found in Denmark in 2007 and 2008 as well as eight old original serotype 6A isolates were characterised.</p> <p>Methods</p> <p>In this study, 181 clinical <it>Streptococcus pneumoniae </it>isolates from Denmark 2007 and 2008 were examined; 96 isolates had previously been typed as serotype 6A and 85 as serotype 6B. In addition, eight older isolates from 1952 to 1987, earlier serotyped as 6A, were examined. Serotype 6C isolates were identified by PCR and serotyping with the Neufeld test using the novel type specific polyclonal antiserum, factor antiserum 6 d, in addition to factor antisera 6b, 6b* (absorbed free for cross-reactions to serotype 6C) and 6c. All antisera are commercially available and antiserum 6b obtained from the supplier after 1 January 2009 is antiserum 6b*. All serotype 6C isolates were further characterised using multi-locus sequence typing.</p> <p>Results</p> <p>When retesting all 96 original serotype 6A isolates by PCR and the Neufeld test, 29.6% (24 of 81) of the invasive isolates in Denmark from 2007 and 2008 were recognised as serotype 6C. In addition, three of eight old isolates originally serotyped as 6A were identified to be serotype 6C. The oldest serotype 6C isolate was from 1962. The serotype 6C isolates belonged to eleven different sequence types (ST) and nine clonal complexes (CC), ST1692 (CC395), ST386 (CC386) and ST481 (CC460) were the predominant types.</p> <p>Conclusions</p> <p>We tested a novel polyclonal antiserum 6 d, as well as modified antiserum 6b*, provided a scheme for the serotyping of <it>S. pneumoniae </it>serogroup 6 using the Neufeld test and compared the serotyping method with PCR based methods. The two types of methods provided the same results. In future, it will, therefore, be possible to test also serotype 6C in accordance to the standard method for serotyping of <it>S. pneumoniae </it>recommended by WHO.</p> <p>Among all invasive isolates from Denmark 2007 and 2008, serotype 6C constituted 29.6% of the original serotype 6A isolates. The serotype 6C isolates were found to be diverse belonging to a number of different STs and CCs of which most have been observed in other countries previously. Serotype 6C is regarded as an "old" serotype being present among <it>S. pneumoniae </it>isolates in Denmark for at least 48 years. The genetic diversity of serotype 6C isolates and their genetic relationship to other serotypes suggested that serotype 6C strains may have arisen from several different independent recombination events involving different parental strains such as serotypes 6A, 6B, 23F and 4.</p

    Pontin functions as an essential coactivator for Oct4-dependent lincRNA expression in mouse embryonic stem cells

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    The actions of transcription factors, chromatin modifiers and noncoding RNAs are crucial for the programming of cell states. Although the importance of various epigenetic machineries for controlling pluripotency of embryonic stem (ES) cells has been previously studied, how chromatin modifiers cooperate with specific transcription factors still remains largely elusive. Here, we find that Pontin chromatin remodelling factor plays an essential role as a coactivator for Oct4 for maintenance of pluripotency in mouse ES cells. Genome-wide analyses reveal that Pontin and Oct4 share a substantial set of target genes involved in ES cell maintenance. Intriguingly, we find that the Oct4-dependent coactivator function of Pontin extends to the transcription of large intergenic noncoding RNAs (lincRNAs) and in particular linc1253, a lineage programme repressing lincRNA, is a Pontin-dependent Oct4 target lincRNA. Together, our findings demonstrate that the Oct4-Pontin module plays critical roles in the regulation of genes involved in ES cell fate determination.111311Ysciescopu

    Anesthesia of Epinephelus marginatus with essential oil of Aloysia polystachya: an approach on blood parameters

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    This study investigated the anesthetic potential of the essential oil (EO) of Aloysia polystachya in juveniles of dusky grouper (Epinephelus marginatus). Fish were exposed to different concentrations of EO of A. polystachya to evaluate time of induction and recovery from anesthesia. In the second experiment, fish were divided into four groups: control, ethanol and 50 or 300 mu L L-1 EO of A. polystachya, and each group was submitted to induction for 3.5 min and recovery for 5 or 10 min. The blood gases and glucose levels showed alterations as a function of the recovery times, but Na+ and K+ levels did not show any alteration. In conclusion, the EO from leaves of A. polystachya is an effective anesthetic for dusky grouper, because anesthesia was reached within the recommended time at EO concentrations of 300 and 400 mu L L-1. However, most evaluated blood parameters showed compensatory responses due to EO exposure.Fundacao de Amparo a Pesquisa do Estado do Rio Grande do Sul/Programa de Apoio a Nucleos de Excelencia (FAPERGS/PRONEX) [10/0016-8]; Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq) [470964/2009-0]; Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior, Brazil (CAPES)info:eu-repo/semantics/publishedVersio

    Epidemiology of Streptococcus pneumoniae and Staphylococcus aureus colonization in healthy Venezuelan children

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    Streptococcus pneumoniae and Staphylococcus aureus cause significant morbidity and mortality worldwide. We investigated both the colonization and co-colonization characteristics for these pathogens among 250 healthy children from 2 to 5Β years of age in Merida, Venezuela, in 2007. The prevalence of S. pneumoniae colonization, S. aureus colonization, and S. pneumoniae–S. aureus co-colonization was 28%, 56%, and 16%, respectively. Pneumococcal serotypes 6B (14%), 19F (12%), 23F (12%), 15 (9%), 6A (8%), 11 (8%), 23A (6%), and 34 (6%) were the most prevalent. Non-respiratory atopy was a risk factor for S. aureus colonization (p = 0.017). Vaccine serotypes were negatively associated with preceding respiratory infection (p = 0.02) and with S. aureus colonization (p = 0.03). We observed a high prevalence of pneumococcal resistance against trimethoprim–sulfamethoxazole (40%), erythromycin (38%), and penicillin (14%). Semi-quantitative measurement of pneumococcal colonization density showed that children with young siblings and low socioeconomic status were more densely colonized (p = 0.02 and p = 0.02, respectively). In contrast, trimethoprim–sulfamethoxazole- and multidrug-resistant-pneumococci colonized children sparsely (p = 0.03 and p = 0.01, respectively). Our data form an important basis to monitor the future impact of pneumococcal vaccination on bacterial colonization, as well as to recommend a rationalized and restrictive antimicrobial use in our community

    The effect of age on the response to the pneumococcal polysaccharide vaccine

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    <p>Abstract</p> <p>Background</p> <p><it>Streptococcus pneumoniae </it>is a leading cause of morbidity and mortality in the elderly. To prevent invasive pneumococcal diseases, the 23-valent pneumococcal polysaccharide vaccine (PPV) is recommended in subjects over 65 years of age. Although it has been reported to provide approximately 50-80% protection against invasive disease in the general elderly population, there is still controversy as to the effectiveness of the PPV in the elderly.</p> <p>Methods</p> <p>To evaluate the immune response to the pneumococcal polysaccharide vaccine in the elderly, samples from young adults and elderly were obtained before and one month after vaccination. The quantitative and qualitative response to the vaccine were measured by the ELISA and opsonophagocytic killing assay for eight vaccine type serotypes (4, 6B, 9V, 14, 18C, 19A, 19F, 23F) and one vaccine-related serotype (6A).</p> <p>Results</p> <p>The response to the pneumococcal polysaccharide vaccine showed a similar response between adults and elderly when evaluated by the ELISA, however the functional activity of the antibodies elicited after vaccination were lower in the elderly group for more than half of the serotypes evaluated. In comparison of the antibody needed for 1:8 opsonic titer, more antibodies were needed in the elderly for serotypes Pn 4, 19F, 23F and 6A, suggesting the functional activity of antibody detected by the ELISA was lower in the elderly compared with the adult group for these serotypes. As for subjects with an opsonic titer <8 after vaccination, only one subject each for serotypes Pn 4, 9V and 6A were found in the adult group. However, up to 10 (30.3%) of the subjects did not show opsonic activity after vaccination in the elderly group for serotypes Pn 4, 9V, 14, 19A and 6A.</p> <p>Conclusions</p> <p>Although the amount of antibodies elicited were similar between the two age groups, distinct differences in function were noted. This report highlights the importance of a quantitative and qualitative evaluation of the immunogenic response to the PPV in the elderly age group.</p> <p>Trial registration</p> <p>This trial is registered with Clinical trials.gov. Registration number NCT00964769</p

    A Robust Approach to Identifying Tissue-Specific Gene Expression Regulatory Variants Using Personalized Human Induced Pluripotent Stem Cells

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    Normal variation in gene expression due to regulatory polymorphisms is often masked by biological and experimental noise. In addition, some regulatory polymorphisms may become apparent only in specific tissues. We derived human induced pluripotent stem (iPS) cells from adult skin primary fibroblasts and attempted to detect tissue-specific cis-regulatory variants using in vitro cell differentiation. We used padlock probes and high-throughput sequencing for digital RNA allelotyping and measured allele-specific gene expression in primary fibroblasts, lymphoblastoid cells, iPS cells, and their differentiated derivatives. We show that allele-specific expression is both cell type and genotype-dependent, but the majority of detectable allele-specific expression loci remains consistent despite large changes in the cell type or the experimental condition following iPS reprogramming, except on the X-chromosome. We show that our approach to mapping cis-regulatory variants reduces in vitro experimental noise and reveals additional tissue-specific variants using skin-derived human iPS cells

    Large intergenic non-coding RNA-RoR modulates reprogramming of human induced pluripotent stem cells

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    February 17, 2011The conversion of lineage-committed cells to induced pluripotent stem cells (iPSCs) by reprogramming is accompanied by a global remodeling of the epigenome[superscript 1, 2, 3, 4, 5], resulting in altered patterns of gene expression[superscript 2, 6, 7, 8, 9]. Here we characterize the transcriptional reorganization of large intergenic non-coding RNAs (lincRNAs)[superscript 10, 11] that occurs upon derivation of human iPSCs and identify numerous lincRNAs whose expression is linked to pluripotency. Among these, we defined ten lincRNAs whose expression was elevated in iPSCs compared with embryonic stem cells, suggesting that their activation may promote the emergence of iPSCs. Supporting this, our results indicate that these lincRNAs are direct targets of key pluripotency transcription factors. Using loss-of-function and gain-of-function approaches, we found that one such lincRNA (lincRNA-RoR) modulates reprogramming, thus providing a first demonstration for critical functions of lincRNAs in the derivation of pluripotent stem cells
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