28 research outputs found

    Upregulation of the cell-cycle regulator RGC-32 in Epstein-Barr virus-immortalized cells

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    Epstein-Barr virus (EBV) is implicated in the pathogenesis of multiple human tumours of lymphoid and epithelial origin. The virus infects and immortalizes B cells establishing a persistent latent infection characterized by varying patterns of EBV latent gene expression (latency 0, I, II and III). The CDK1 activator, Response Gene to Complement-32 (RGC-32, C13ORF15), is overexpressed in colon, breast and ovarian cancer tissues and we have detected selective high-level RGC-32 protein expression in EBV-immortalized latency III cells. Significantly, we show that overexpression of RGC-32 in B cells is sufficient to disrupt G2 cell-cycle arrest consistent with activation of CDK1, implicating RGC-32 in the EBV transformation process. Surprisingly, RGC-32 mRNA is expressed at high levels in latency I Burkitt's lymphoma (BL) cells and in some EBV-negative BL cell-lines, although RGC-32 protein expression is not detectable. We show that RGC-32 mRNA expression is elevated in latency I cells due to transcriptional activation by high levels of the differentially expressed RUNX1c transcription factor. We found that proteosomal degradation or blocked cytoplasmic export of the RGC-32 message were not responsible for the lack of RGC-32 protein expression in latency I cells. Significantly, analysis of the ribosomal association of the RGC-32 mRNA in latency I and latency III cells revealed that RGC-32 transcripts were associated with multiple ribosomes in both cell-types implicating post-initiation translational repression mechanisms in the block to RGC-32 protein production in latency I cells. In summary, our results are the first to demonstrate RGC-32 protein upregulation in cells transformed by a human tumour virus and to identify post-initiation translational mechanisms as an expression control point for this key cell-cycle regulator

    Latent Epstein-Barr Virus Can Inhibit Apoptosis in B Cells by Blocking the Induction of NOXA Expression

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    Latent Epstein-Barr virus (EBV) has been shown to protect Burkitt's lymphoma-derived B cells from apoptosis induced by agents that cause damage to DNA, in the context of mutant p53. This protection requires expression of the latency-associated nuclear proteins EBNA3A and EBNA3C and correlates with their ability to cooperate in the repression of the gene encoding the pro-apoptotic, BH3-only protein BIM. Here we confirm that latent EBV in B cells also inhibits apoptosis induced by two other agents – ionomycin and staurosporine – and show that these act by a distinct pathway that involves a p53-independent increase in expression of another pro-apoptotic, BH3-only protein, NOXA. Analyses employing a variety of B cells infected with naturally occurring EBV or B95.8 EBV-BAC recombinant mutants indicated that the block to NOXA induction does not depend on the well-characterized viral latency-associated genes (EBNAs 1, 2, 3A, 3B, 3C, the LMPs or the EBERs) or expression of BIM. Regulation of NOXA was shown to be at least partly at the level of mRNA and the requirement for NOXA to induce cell death in this context was demonstrated by NOXA-specific shRNA-mediated depletion experiments. Although recombinant EBV with a deletion removing the BHRF1 locus – that encodes the BCL2-homologue BHRF1 and three microRNAs – partially abrogates protection against ionomycin and staurosporine, the deletion has no effect on the EBV-mediated block to NOXA accumulation

    Metabolic cutis laxa syndromes

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    Cutis laxa is a rare skin disorder characterized by wrinkled, redundant, inelastic and sagging skin due to defective synthesis of elastic fibers and other proteins of the extracellular matrix. Wrinkled, inelastic skin occurs in many cases as an acquired condition. Syndromic forms of cutis laxa, however, are caused by diverse genetic defects, mostly coding for structural extracellular matrix proteins. Surprisingly a number of metabolic disorders have been also found to be associated with inherited cutis laxa. Menkes disease was the first metabolic disease reported with old-looking, wrinkled skin. Cutis laxa has recently been found in patients with abnormal glycosylation. The discovery of the COG7 defect in patients with wrinkled, inelastic skin was the first genetic link with the Congenital Disorders of Glycosylation (CDG). Since then several inborn errors of metabolism with cutis laxa have been described with variable severity. These include P5CS, ATP6V0A2-CDG and PYCR1 defects. In spite of the evolving number of cutis laxa-related diseases a large part of the cases remain genetically unsolved. In metabolic cutis laxa syndromes the clinical and laboratory features might partially overlap, however there are some distinct, discriminative features. In this review on metabolic diseases causing cutis laxa we offer a practical approach for the differential diagnosis of metabolic cutis laxa syndromes

    Oral health-related quality of life of children with oral clefts and their families

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    Abstract Oral health problems can influence people's Quality of Life (QoL) because of pain, discomfort, limitations, and other esthetics problems, affecting their social life, feeding, daily activities, and the individual's well-being. Objective: To compare oral health-related quality of life (OHRQoL) of children with and without oral clefts and their families. Materials and Methods: 121 children aged from 2 to 6 years, from both sexes, enrolled in the treatment routine of the Pediatric Dentistry Clinics of a Dental School and a Hospital for Cleft Treatment were divided into two groups: Group 1 - children with cleft lip and palate; Group 2 - children without cleft lip and palate. The OHRQoL was assessed using the validated Portuguese version of the Early Childhood Oral Health Impact Scale (B-ECOHIS). The questionnaire was answered individually, only once, at a private place. Mann-Whitney U test was used to verify differences between groups. Spearman's Rho test was used to associate sex and age with quality of life. The level of significance was set at 5% (p<0.05). Results: According to the parents’ perception on the OHRQoL of children with and without cleft lip and palate, oral health of children with oral clefts (Group 1) had a statistically significant impact on OHRQoL. The correlation of sex with impact on OHRQoL did not show statistically significant differences. On the other hand, the higher the age the higher the impact on QoL. Conclusions: The group comparison revealed that the cleft lip and palate negatively impacted on OHRQoL of 2 to 6-year-old children and their parents

    Oral manifestations of systemic disease

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    While the majority of disorders of the mouth are centred upon the direct action of plaque, the oral tissues can be subject to change or damage as a consequence of disease that predominantly affects other body systems. Such oral manifestations of systemic disease can be highly variable in both frequency and presentation. As lifespan increases and medical care becomes ever more complex and effective it is likely that the numbers of individuals with oral manifestations of systemic disease will continue to rise. The present article provides a succinct review of oral manifestations of systemic disease. In view of this article being part of a wider BDJ themed issue on the subject of oral medicine, this review focuses upon oral mucosal and salivary gland disorders that may arise as a consequence of systemic disease

    O impacto odontológico no desempenho diário dos trabalhadores do departamento municipal de limpeza urbana de Porto Alegre, Rio Grande do Sul, Brasil The impact of oral health on daily performance of municipal waste disposal workers in Porto Alegre, Rio Grande do Sul State, Brazil

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    O objetivo deste estudo foi investigar a prevalência do impacto bucal no desempenho diário em adultos brasileiros. Uma amostra representativa, composta por 276 funcionários do Departamento Municipal de Limpeza Urbana de Porto Alegre, Rio Grande do Sul, Brasil, entre 35 e 44 anos, responderam a entrevista e permitiram a realização do exame clínico. O Oral Impacts on Daily Performances (OIDP) foi utilizado para avaliar o impacto bucal no desempenho diário. Do total de participantes, 73,6% tiveram pelo menos um desempenho diário afetado por problemas odontológicos nos últimos seis meses. O mais afetado foi comer e apreciar a comida (48,6%). O desconforto (40,6%) e a insatisfação com a aparência (31,5%) foram os sintomas mais prevalentes. A falta de dentes (21,7%) e a dor de dente (20,7%) foram as principais causas percebidas de impacto no desempenho diário. O OIDP mostrou-se útil para avaliar os impactos odontológicos nas dimensões físicas, psicológicas e sociais do desempenho diário.<br>This study aimed to investigate the prevalence of oral health impact on daily performance in Brazilian adults. 276 civil servants 35 to 44 years of age from the Public Works and Waste Disposal Department of Porto Alegre, in southern Brazil, were interviewed and clinically examined. Oral Impacts on Daily Performance (OIDP) was used to evaluate the impact of oral health status on daily performance. 73.6% of all subjects had at least one daily performance affected by an oral impact in the previous six months. The most commonly affected performance was eating (48.6%), while the most common symptoms were discomfort (40.6%) and dissatisfaction with one's appearance (31.5%). Missing teeth (21.7%) and toothache (20.7%) were recognized as the main causes of oral impacts on daily performance. OIDP was useful for measuring (physically, psychologically, and socially) the oral impacts on daily performance
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