62 research outputs found
A multicenter, prospective cohort study
Organ transplant recipients (OTRs) have a 100‐fold increased risk of cutaneous
squamous cell carcinoma (cSCC). We prospectively evaluated the association
between β genus human papillomaviruses (βPV) and keratinocyte carcinoma in
OTRs. Two OTR cohorts without cSCC were assembled: cohort 1 was transplanted
in 2003‐2006 (n = 274) and cohort 2 was transplanted in 1986‐2002 (n = 352).
Participants were followed until death or cessation of follow‐up in 2016. βPV
infection was assessed in eyebrow hair by using polymerase chain
reaction–based methods. βPV IgG seroresponses were determined with multiplex
serology. A competing risk model with delayed entry was used to estimate
cumulative incidence of histologically proven cSCC and the effect of βPV by
using a multivariable Cox regression model. Results are reported as adjusted
hazard ratios (HRs). OTRs with 5 or more different βPV types in eyebrow hair
had 1.7 times the risk of cSCC vs OTRs with 0 to 4 different types (HR 1.7,
95% confidence interval 1.1‐2.6). A similar risk was seen with high βPV loads
(HR 1.8, 95% confidence interval 1.2‐2.8). No significant associations were
seen between serum antibodies and cSCC or between βPV and basal cell
carcinoma. The diversity and load of βPV types in eyebrow hair are associated
with cSCC risk in OTRs, providing evidence that βPV is associated with cSCC
carcinogenesis and may present a target for future preventive strategies
\u3cem\u3eTrichodysplasia Spinulosa\u3c/em\u3e-Associated Polyomavirus Uses a Displaced Binding Site on VP1 to Engage Sialylated Glycolipids
Trichodysplasia spinulosa-associated Polyomavirus (TSPyV) was isolated from a patient suffering from trichodysplasia spinulosa, a skin disease that can appear in severely immunocompromised patients. While TSPyV is one of the five members of the polyomavirus family that are directly linked to a human disease, details about molecular recognition events, the viral entry pathway, and intracellular trafficking events during TSPyV infection remain unknown. Here we have used a structure-function approach to shed light on the first steps of TSPyV infection. We established by cell binding and pseudovirus infection studies that TSPyV interacts with sialic acids during attachment and/or entry. Subsequently, we solved high-resolution X-ray structures of the major capsid protein VP1 of TSPyV in complex with three different glycans, the branched GM1 glycan, and the linear trisaccharides α2,3- and α2,6-sialyllactose. The terminal sialic acid of all three glycans is engaged in a unique binding site on TSPyV VP1, which is positioned about 18 Å from established sialic acid binding sites of other polyomaviruses. Structure-based mutagenesis of sialic acid-binding residues leads to reduction in cell attachment and pseudovirus infection, demonstrating the physiological relevance of the TSPyV VP1-glycan interaction. Furthermore, treatments of cells with inhibitors of N-, O-linked glycosylation, and glycosphingolipid synthesis suggest that glycolipids play an important role during TSPyV infection. Our findings elucidate the first molecular recognition events of cellular infection with TSPyV and demonstrate that receptor recognition by polyomaviruses is highly variable not only in interactions with sialic acid itself, but also in the location of the binding site
Trabalho infantil : uma análise das tentativas de sua erradicação no Brasil
Orientadora: Profª Drª Silvia Maria P. AraújoDissertaçao (mestrado) - Universidade Federal do Paraná, Setor de Ciencias Humanas, Letras e Artes, Programa de Pós-Graduaçao em Sociologia. Defesa: Curitiba, 22/12/2003Inclui bibliografiaResumo: Esta dissertação pretende analisar a problemática da erradicação do trabalho infantil a partir dos discursos que se produziram ao longo da história moderna, relativos às descrições de infância e dos contextos que separam o mundo adulto do mundo infantil, ou, ao retrato da construção social do que representa a infância: o mundo do trabalho como retrato do universo adulto e a educação formal (escola) como síntese da vida em formação. Os pressupostos da educação formal e do trabalho norteiam as discussões que embasam os discursos a partir dos quais, a reprodução de valores inerentes ao sistema capitalista e suas contradições, evidenciam a necessidade de se elaborar um problema social, o qual necessita de descrição, avaliação e intervenção. Ao trazer a problemática da construção do trabalho infantil como problema social, esta pesquisa pretende analisar o processo histórico da construção da problemática do trabalho infantil retratado como um problema que deve ser exterminado, segundo os discursos, tendo como base categorias trabalho e infância. Pretende ainda, compreender o contexto histórico e socioeconômico no qual o trabalho infantil passou a ser combatido como um problema social, mais precisamente no Brasil, por meio de políticas públicas, bem como, identificar no processo do que se denomina de erradicação, a garantia do controle da formação de mão-de-obra, através dos programas voltados aos jovens e às crianças pobres e vulneráveis. Por fim, esta pesquisa lança uma reflexão sobre a necessidade de participação das crianças na elaboração de documentos ou iniciativas, que garantam os direitos da infância e da adolescência e que as mesmas possam escolher dentro de suas respectivas realidades, como traçar seus destinos. A pesquisa tem como base a coleta de dados documentais que evidenciam o pressuposto de trabalho infantil como um problema social, bem como, as contradições no discurso da erradicação, contemplando documentos do PETI (Programa de Erradicação do Trabalho Infantil), do Fórum Nacional de Prevenção e Erradicação do Trabalho Infantil e do ECA (Estatuto da Criança e do Adolescente), além de participações nas reuniões do Fórum, em Curitiba, na Procuradoria Regional do Trabalho, durante o ano de 2002
Communion by extension : discrepancies between policy and practice
The growing practice of Communion by Extension was given formal authorisation by the Church of England General Synod in 2000 with the expectation that it would be used in particular circumstances, including explicitly the rural multi-church benefice. This paper reviews the historical origins of the practice of Communion by Extension and clarifies the intentions of the authorisation given in 2000. Then the intentions of the 2000 authorisation are compared and contrasted with current parochial practice within one English diocese. Considerable divergence is found. Five main themes are identified and discussed: the relationship between worship and mission; the pressures on clerical time; sacramental self-sufficiency; the value given to familiarity; and the choice between reservation and congregationalism
Primary Polyomavirus Infection, Not Reactivation, as the Cause of Trichodysplasia Spinulosa in Immunocompromised Patients
Classic human polyomaviruses (JC and BK viruses) become pathogenic when reactivating from latency. For the rare skin disease trichodysplasia spinulosa, we show that manifestations of the causative polyomavirus (TSPyV) occur during primary infection of the immunosuppressed host. High TSPyV loads in blood and cerebrospinal fluid, sometimes coinciding with cerebral lesions and neuroendocrine symptoms, marked the acute phase of trichodysplasia spinulosa, whereas initiation and maturation of TSPyV seroresponses occurred in the convalescent phase. TSPyV genomes lacked the rearrangements typical for reactivating polyomaviruses. These findings demonstrate the clinical importance of primary infection with this rapidly expanding group of human viruses and explain the rarity of some novel polyomavirus-associated diseases.Peer reviewe
Recommendations for the introduction of metagenomic high-throughput sequencing in clinical virology, part I:Wet lab procedure
Metagenomic high-throughput sequencing (mHTS) is a hypothesis-free, universal pathogen detection technique for determination of the DNA/RNA sequences in a variety of sample types and infectious syndromes. mHTS is still in its early stages of translating into clinical application. To support the development, implementation and standardization of mHTS procedures for virus diagnostics, the European Society for Clinical Virology (ESCV) Network on Next-Generation Sequencing (ENNGS) has been established. The aim of ENNGS is to bring together professionals involved in mHTS for viral diagnostics to share methodologies and experiences, and to develop application recommendations. This manuscript aims to provide practical recommendations for the wet lab procedures necessary for implementation of mHTS for virus diagnostics and to give recommendations for development and validation of laboratory methods, including mHTS quality assurance, control and quality assessment protocols
Discovery of a New Human Polyomavirus Associated with Trichodysplasia Spinulosa in an Immunocompromized Patient
The Polyomaviridae constitute a family of small DNA viruses infecting a variety of hosts. In humans, polyomaviruses can cause infections of the central nervous system, urinary tract, skin, and possibly the respiratory tract. Here we report the identification of a new human polyomavirus in plucked facial spines of a heart transplant patient with trichodysplasia spinulosa, a rare skin disease exclusively seen in immunocompromized patients. The trichodysplasia spinulosa-associated polyomavirus (TSV) genome was amplified through rolling-circle amplification and consists of a 5232-nucleotide circular DNA organized similarly to known polyomaviruses. Two putative “early” (small and large T antigen) and three putative “late” (VP1, VP2, VP3) genes were identified. The TSV large T antigen contains several domains (e.g. J-domain) and motifs (e.g. HPDKGG, pRb family-binding, zinc finger) described for other polyomaviruses and potentially involved in cellular transformation. Phylogenetic analysis revealed a close relationship of TSV with the Bornean orangutan polyomavirus and, more distantly, the Merkel cell polyomavirus that is found integrated in Merkel cell carcinomas of the skin. The presence of TSV in the affected patient's skin was confirmed by newly designed quantitative TSV-specific PCR, indicative of a viral load of 105 copies per cell. After topical cidofovir treatment, the lesions largely resolved coinciding with a reduction in TSV load. PCR screening demonstrated a 4% prevalence of TSV in an unrelated group of immunosuppressed transplant recipients without apparent disease. In conclusion, a new human polyomavirus was discovered and identified as the possible cause of trichodysplasia spinulosa in immunocompromized patients. The presence of TSV also in clinically unaffected individuals suggests frequent virus transmission causing subclinical, probably latent infections. Further studies have to reveal the impact of TSV infection in relation to other populations and diseases
Seroprevalence of fourteen human polyomaviruses determined in blood donors.
The polyomavirus family currently includes thirteen human polyomavirus (HPyV) species. In immunocompromised and elderly persons HPyVs are known to cause disease, such as progressive multifocal leukoencephalopathy (JCPyV), haemorrhagic cystitis and nephropathy (BKPyV), Merkel cell carcinoma (MCPyV), and trichodysplasia spinulosa (TSPyV). Some recently discovered polyomaviruses are of still unknown prevalence and pathogenic potential. Because HPyVs infections persist and might be transferred by blood components to immunocompromised patients, we studied the seroprevalence of fourteen polyomaviruses in adult Dutch blood donors. For most polyomaviruses the observed seroprevalence was high (60-100%), sometimes slightly increasing or decreasing with age. Seroreactivity increased with age for JCPyV, HPyV6 and HPyV7 and decreased for BKPyV and TSPyV. The most recently identified polyomaviruses HPyV12, NJPyV and LIPyV showed low overall seroprevalence (~5%) and low seroreactivity, questioning their human tropism. Altogether, HPyV infections are common in Dutch blood donors, with an average of nine polyomaviruses per subject
From Stockholm to Malawi: recent developments in studying human polyomaviruses
Until a few years ago the polyomavirus family (Polyomaviridae) included a dozen viruses identified in avian and mammalian hosts. Two of these, the JC and BK-polyomaviruses isolated a long time ago, are known to infect humans and cause severe illness in immunocompromised hosts. Since 2007 an unprecedented number of eight novel polyomaviruses were discovered in humans. Among them are the KI- and WU-polyomaviruses identified in respiratory samples, the Merkel cell polyomavirus found in skin carcinomas and the polyomavirus associated with trichodysplasia spinulosa, a skin disease of transplant patients. Another four novel human polyomaviruses were identified, HPyV6, HPyV7, HPyV9 and the Malawi polyomavirus, so far not associated with any disease. In the same period several novel mammalian polyomaviruses were described. This review summarizes the recent developments in studying the novel human polyomaviruses, and touches upon several aspects of polyomavirus virology, pathogenicity, epidemiology and phylogeny
Human papillomavirus 8 E6 disrupts terminal skin differentiation and prevents pro-Caspase-14 cleavage
Expression of the betapapillomavirus (betaPV) E6/E7 genes has been shown to impair both keratinocyte differentiation and apoptosis. Especially late-terminal keratinocyte differentiation shares certain aspects with apoptosis, such as fragmentation of DNA and activation of caspases. Here we investigated the disruption of keratinocyte differentiation in organotypic skin (raft) cultures of primary (PHK) and immortalized (N/TERT) human keratinocytes, in particular by human papillomavirus (HPV)8.Immunohistochemical analysis of HPV5 and HPV8 E6/E7-expressing PHK revealed thickening of the rafts and complete absence of stratum corneum formation, even after 18 days of culture. This phenotype was confirmed in N/TERT raft cultures. When expressed separately, the aberrant morphology was observed only in rafts expressing E6, not E7. Immunofluorescence analysis of HPV8 E6 PHK rafts showed an increase in number and size of Filaggrin- and Caspase-14-positive cells in the granular layer. In raft lysates analyzed by western-blot, the presence of pro-Caspase-14 in the differentiated keratinocytes was confirmed, but in the HPV8 E6 rafts none of the Caspase-14 subunits were detected.In conclusion, in the raft system, HPV8 E6 prevented late-terminal keratinocyte differentiation resulting in an accumulation of Filaggrin and pro-Caspase-14-positive cells in the absence of stratification. This differentiation arrest was accompanied by the failure to express Caspase-14 subunits, suggesting absence of Caspase-14 activation and probable abrogation of Filaggrin maturation in HPV8 E6-expressing keratinocytes
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