316 research outputs found

    PRIMA-1MET induces nucleolar translocation of Epstein-Barr virus-encoded EBNA-5 protein

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    The low molecular weight compound, PRIMA-1MET restores the transcriptional transactivation function of certain p53 mutants in tumor cells. We have previously shown that PRIMA-1MET induces nucleolar translocation of p53, PML, CBP and Hsp70. The Epstein-Barr virus encoded, latency associated antigen EBNA-5 (also known as EBNA-LP) is required for the efficient transformation of human B lymphocytes by EBV. EBNA-5 associates with p53-hMDM2-p14ARF complexes. EBNA-5 is a nuclear protein that translocates to the nucleolus upon heat shock or inhibition of proteasomes along with p53, hMDM2, Hsp70, PML and proteasome subunits. Here we show that PRIMA-1MET induces the nucleolar translocation of EBNA-5 in EBV transformed B lymphoblasts and in transfected tumor cells. The PRIMA-1MET induced translocation of EBNA-5 is not dependent on the presence of mutant p53. It also occurs in p53 null cells or in cells that express wild type p53. Both the native and the EGFP or DSRed conjugated EBNA-5 respond to PRIMA-1MET treatment in the same way. Image analysis of DSRed-EBNA-5 expressing cells, using confocal fluorescence time-lapse microscopy showed that the nucleolar translocation requires several hours to complete. FRAP (fluorescence recovery after photobleaching) and FLIP (fluorescence loss in photobleaching) measurements on live cells showed that the nucleolar translocation was accompanied by the formation of EBNA-5 aggregates. The process is reversible since the aggregates are dissolved upon removal of PRIMA-1MET. Our results suggest that mutant p53 is not the sole target of PRIMA-1MET. We propose that PRIMA-1MET may reversibly inhibit cellular chaperons that prevent the aggregation of misfolded proteins, and that EBNA-5 may serve as a surrogate drug target for elucidating the precise molecular action of PRIMA-1MET

    Precision glycan supplementation: A strategy to improve performance and intestinal health of laying hens in high‐stress commercial environments

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    In the dynamic world of animal production, many challenges arise in disease control, animal welfare and the need to meet antibiotic‐free demands. Emerging diseases have a significant impact on the poultry industry. Managing gut microbiota is an important determinant of poultry health and performance. Introducing precision glycans as feed additives adds another dimension to this complex environment. The glycans play pivotal roles in supporting gut health and immunological processes and are likely to limit antibiotic usage while enhancing intestinal well‐being and overall poultry performance. This study explores precision glycan product as a feed additive supplemented at a continuous dose of 900 g per tonne of feed, in a free‐range production system on a large commercial farm. Forty thousand 17‐week‐old pullets were randomly allocated to one of two separated sections of the production shed, with individual silos and egg‐collecting belts. The flock performance, gut microbiota and its functionality were analysed throughout the laying cycle until 72 weeks of age. The results demonstrated that introducing precision glycans improved a range of performance indicators, including reduced cumulative mortality, especially during a major smothering event, where the birds pile up until they suffocate. There was also significantly increased hen‐housed egg production, reduced gut dysbiosis score and undigested feed, increased number of goblet cells and improved feed conversion ratio. Additionally, microbiota analysis revealed significant changes in the composition of the gizzard, ileum content, ileum mucosa, and caecal and cloacal regions. Overall, the findings suggest that precision glycans have the potential to enhance poultry egg production in challenging farming environments

    Associations between SNPs in candidate immune-relevant genes and rubella antibody levels: a multigenic assessment

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    <p>Abstract</p> <p>Background</p> <p>The mechanisms of immune response are structured within a highly complex regulatory system. Genetic associations with variation in the immune response to rubella vaccine have typically been assessed one locus at a time. We simultaneously assessed the associations between 726 SNPs tagging 84 candidate immune response genes and rubella-specific antibody levels. Blood samples were obtained from 714 school-aged children who had received two doses of MMR vaccine. Associations between rubella-specific antibody levels and 726 candidate tagSNPs were assessed both one SNP at a time and in a variety of multigenic analyses.</p> <p>Results</p> <p>Single-SNP assessments identified 4 SNPs that appeared to be univariately associated with rubella antibody levels: rs2844482 (p = 0.0002) and rs2857708 (p = 0.001) in the 5'UTR of the LTA gene, rs7801617 in the 5'UTR of the IL6 gene (p = 0.0005), and rs4787947 in the 5'UTR of the IL4R gene (p = 0.002). While there was not significant evidence in favor of epistatic genetic associations among the candidate SNPs, multigenic analyses identified 29 SNPs significantly associated with rubella antibody levels when selected as a group (p = 0.017). This collection of SNPs included not only those that were significant univariately, but others that would not have been identified if only considered in isolation from the other SNPs.</p> <p>Conclusions</p> <p>For the first time, multigenic assessment of associations between candidate SNPs and rubella antibody levels identified a broad number of genetic associations that would not have been deemed important univariately. It is important to consider approaches like those applied here in order to better understand the full genetic complexity of response to vaccination.</p

    Terbinafine is a novel and selective activator of the two-pore domain potassium channel TASK3

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    Two-pore domain potassium channels (K2Ps) are characterized by their four transmembrane domain and two-pore topology. They carry background (or leak) potassium current in a variety of cell types. Despite a number of important roles there is currently a lack of pharmacological tools with which to further probe K2P function. We have developed a cell-based thallium flux assay, using baculovirus delivered TASK3 (TWIK-related acid-sensitive K+ channel 3, KCNK9, K2P9.1) with the aim of identifying novel, selective TASK3 activators. After screening a library of 1000 compounds, including drug-like and FDA approved molecules, we identified Terbinafine as an activator of TASK3. In a thallium flux assay a pEC50 of 6.2 ( ±0.12) was observed. When Terbinafine was screened against TASK2, TREK2, THIK1, TWIK1 and TRESK no activation was observed in thallium flux assays. Several analogues of Terbinafine were also purchased and structure activity relationships examined. To confirm Terbinafine's activation of TASK3 whole cell patch clamp electrophysiology was carried out and clear potentiation observed in both the wild type channel and the pathophysiological, Birk-Barel syndrome associated, G236R TASK3 mutant. No activity at TASK1 was observed in electrophysiology studies. In conclusion, we have identified the first selective activator of the two-pore domain potassium channel TASK3

    Expression of Mo3e antigen by cultured human umbilical vein endothelial cells (HUVEC) stimulated by phorbol myristate acetate (PMA) and related pharmacological inducers of protein kinase C

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    Mo3e is a protease-sensitive membrane antigen (p75,50) selectively expressed by human monocytic cells (monocytes and U-937 cells) stimulated in vitro by exposure to a variety of activating factors, including phorbol diester compounds, bacterial lipopolysaccharide (LPS), and muramyl dipeptide (MDP) (R. F. Todd et al., J. Immunol. 135, 3869, 1985). Here we report that primary and multiply-passaged cultures of HUVEC also express the Mo3e determinant after stimulation by phorbol myristate acetate (PMA) and related inducers of protein kinase C. As measured in a radioimmunoassay of anti-Mo3e antibody binding to monolayer cultures of HUVEC, unstimulated cells bore little if any Mo3e. After culture for 4-120 hr in medium containing PMA, 4[beta]-phorbol dibutyrate, 4[beta]-phorbol didecanoate, or mezerein (each at a conentration of 81 nM), or 1-oleoyl-2-acetoyl-sn-3-glycerol (1 mM), HUVEC were found to selectively express the Mo3e determinant. The magnitude of expression was dependent upon the concentration of the stimulus, maximal by 24 hr, and inhibited by cycloheximide. The combination of PMA and the calcium ionophore, ionomycin, had an additive or synergistic effect on HUVEC Mo3e expression. The biologically inactive phorbol compounds 4[beta]-phorbol and 4[alpha]-phorbol didecanoate failed to stimulate Mo3e expression. Also inactive as inducers of HUVEC Mo3e expression were crude lymphokine and monokine supernatants, recombinant human lymphokines (interferon-[gamma] and interleukin-2), recombinant human monokines (interleukin-1 and tumor necrosis factor), bacterial cell wall products including LPS and MDP, pharmacologic agents that increase intracellular cyclic adenosine monophosphate (prostaglandin E2, cholera toxin, theophylline, isoproterenol and isobutylmethylxanthine), lectins (Con A and PHA), and heparin. These results indicate that Mo3e is an inducible plasma membrane antigen of not only mononuclear phagocytes but also cultured HUVEC.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/27376/1/0000404.pd

    TERBINAFINE: EFFICACY AND SAFETY IN THE TREATMENT OF DERMATOPHYTOSIS

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    A double-blind study with terbinafine was performed in 39 patients with dermatophyte infection, between 1987 and 1989, to compare the safety and efficacy of two dosage schedules of 125 mg twice daily versus 250 mg once daily. Mycologic assessments were negative by microscopic examination and Sabouraud's culture in 59% and 100% of patients in the first and the fourth weeks of treatment, respectively. There was no statistically significant difference between the two groups of patients receiving 125 mg b.i.d. and 250 mg q.d. with respect to the safety and efficacy of the treatment; however, the differences between the sums of clinical scores before and after the treatment were statistically significant. There were no adverse effects, and the drug was well tolerated
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