38 research outputs found

    Peripheral blood lymphocyte proliferative responses in cattle infected with or vaccinated against Anaplasma marginale

    Get PDF
    An assay was developed for measurement of the peripheral blood lymphocyte proliferative response (PBLPR) in cattle infected with or immunised against Anaplasma marginale. PBLPR was not evident in all cattle that had recovered from A. marginale infection. However, A. marginale-sensitised lymphocytes were detected in the spleens of all immune cattle tested in the absence of detectable PBLPR. During the course of initial infection, cattle exhibited detectable PBLPR for a period corresponding with and up to 2 weeks after patent parasitaemia, followed by a second, usually larger peak in PBLPR corresponding to the time of sub-clinical relapse of cattle. Analysis of the PBLPR of A. marginale chronically infected cattle demonstrated highly variable PBLPR between individuals and over time. A positive PBLPR was induced in cattle by vaccination using a crude A. marginale antigen preparation. The PBLPR of vaccinated cattle subsequently infected with A. marginale was markedly different from that of naive cattle, with reduced PBLPR being associated with the onset of parasitaemia. The antigen used in the PBLPR assay was inactivated by proteolysis. Proteolysis also abolished immunity that had been induced in cattle vaccinated using the antigen preparation. A. marginale-sensitised PBL did not proliferate in response to antigen from the heterologous species A. centrale. A. centrale-sensitised PBL, however, responded to A. marginale antigen. Interferon-γ (IFN-γ) was detected in PBLPR-assay supernatants and was associated with a strong PBLPR

    Complex structural rearrangements are present in high-grade dysplastic Barrett\u27s oesophagus samples

    Get PDF
    Background: Oesophageal adenocarcinoma (EAC) incidence is increasing and has a poor survival rate. Barrett’s oesophagus (BE) is a precursor condition that is associated with EAC and often occurs in conjunction with chronic gastro-oesophageal reflux, however many individuals diagnosed with BE never progress to cancer. An understanding of the genomic features of BE and EAC may help with the early identification of at-risk individuals. Methods: In this study, we assessed the genomic features of 16 BE samples using whole-genome sequencing. These included non-dysplastic samples collected at two time-points from two BE patients who had not progressed to EAC over several years. Seven other non-dysplastic samples and five dysplastic BE samples with high-grade dysplasia were also examined. We compared the genome profiles of these 16 BE samples with 22 EAC samples. Results: We observed that samples from the two non-progressor individuals had low numbers of somatic single nucleotide variants, indels and structural variation events compared to dysplastic and the remaining non-dysplastic BE. EAC had the highest level of somatic genomic variations. Mutational signature 17, which is common in EAC, was also present in non-dysplastic and dysplastic BE, but was not present in the non-progressors. Many dysplastic samples had mutations in genes previously reported in EAC, whereas only mutations in CDKN2A or in the fragile site genes appeared common in non-dysplastic samples. Rearrangement signatures were used to identify a signature associated with localised complex events such as chromothripsis and breakage fusion-bridge that are characteristic of EACs. Two dysplastic BE samples had a high contribution of this signature and contained evidence of localised rearrangements. Two other dysplastic samples also had regions of localised structural rearrangements. There was no evidence for complex events in non-dysplastic samples. Conclusions: The presence of complex localised rearrangements in dysplastic samples indicates a need for further investigations into the role such events play in the progression from BE to EAC

    Il sito web dell'Osservatorio Vesuviano

    Get PDF
    L'Osservatorio Vesuviano ha di recente realizzato una radicale ristrutturazione del proprio sito Web, attivo dalla seconda metà del 1997, al fine di adeguarlo alla sua nuova configurazione giuridica. Infatti, dal 10 gennaio 2001 è entrato a far parte dell'Istituto Nazionale di Geofisica e Vulcanologia (INGV), un ente nazionale di nuova formazione in cui sono confluiti i maggiori enti ed istituzioni di ricerca operanti nel campo della geofisica e della vulcanologia in Italia. Con la nascita dell'INGV si è posta un'esigenza di coordinamento tra i siti web di dette istituzioni, che si configurano attualmente come sezioni del nuovo ente nazionale. Inoltre, è sorta la necessità di creare delle pagine comuni, relative all'ente nella sua totalità, che introducessero i visitatori alle pagine delle singole sezioni ed eventualmente a specifici tematismi riguardanti le attività dell'ente. A tal fine, è stato istituito un gruppo di Coordinamento Nazionale per il Web che comprende personale afferente alle diverse sezioni. Parallelamente sono stati istituiti gruppi di lavoro locali per la ristrutturazione dei siti delle sezioni. Nell'ambito di questa riorganizzazione, presso l'Osservatorio Vesuviano, con Decreto Direttoriale N. 6, del 30 gennaio 2002, è stato istituito un gruppo di lavoro con il compito di curare la progettazione e lo sviluppo del nuovo sito web della sezione. Nello svolgimento di questa attività il gruppo di lavoro si è posto come obbiettivi prioritari l'usabilità e l'accessibilità del sito, in ottemperanza alle indicazioni espresse dalla più recente normativa apparsa in materia. Per perseguire a pieno questi obbiettivi e garantire la massima fruibilità delle informazioni è stata prevista, fin dalla fase progettuale, la realizzazione del sito anche in versione inglese, che attualmente è in allestimento. Il nuovo sito web dell'Osservatorio Vesuviano è stato messo in linea il 22 maggio 2002 ed è visitabile all'indirizzo http://www.ov.ingv.it. Nel seguito del presente rapporto sono introdotte sinteticamente le finalità istituzionali e le principali attività dell'Osservatorio Vesuviano e sono descritte le fasi di progettazione e sviluppo del sito, con particolare dettaglio sulla strutturazione dei contenuti, definita nell'ambito delle linee dettate dal decreto di istituzione del gruppo di lavoro, e sulle scelte tecnologiche adottate

    Complex structural rearrangements are present in high-grade dysplastic Barrett’s oesophagus samples

    Get PDF
    This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.Abstract Background Oesophageal adenocarcinoma (EAC) incidence is increasing and has a poor survival rate. Barrett’s oesophagus (BE) is a precursor condition that is associated with EAC and often occurs in conjunction with chronic gastro-oesophageal reflux, however many individuals diagnosed with BE never progress to cancer. An understanding of the genomic features of BE and EAC may help with the early identification of at-risk individuals. Methods In this study, we assessed the genomic features of 16 BE samples using whole-genome sequencing. These included non-dysplastic samples collected at two time-points from two BE patients who had not progressed to EAC over several years. Seven other non-dysplastic samples and five dysplastic BE samples with high-grade dysplasia were also examined. We compared the genome profiles of these 16 BE samples with 22 EAC samples. Results We observed that samples from the two non-progressor individuals had low numbers of somatic single nucleotide variants, indels and structural variation events compared to dysplastic and the remaining non-dysplastic BE. EAC had the highest level of somatic genomic variations. Mutational signature 17, which is common in EAC, was also present in non-dysplastic and dysplastic BE, but was not present in the non-progressors. Many dysplastic samples had mutations in genes previously reported in EAC, whereas only mutations in CDKN2A or in the fragile site genes appeared common in non-dysplastic samples. Rearrangement signatures were used to identify a signature associated with localised complex events such as chromothripsis and breakage fusion-bridge that are characteristic of EACs. Two dysplastic BE samples had a high contribution of this signature and contained evidence of localised rearrangements. Two other dysplastic samples also had regions of localised structural rearrangements. There was no evidence for complex events in non-dysplastic samples. Conclusions The presence of complex localised rearrangements in dysplastic samples indicates a need for further investigations into the role such events play in the progression from BE to EAC

    3,4-Methylenedioxymethamphetamine (MDMA) neurotoxicity in rats: a reappraisal of past and present findings

    Get PDF
    RATIONALE: 3,4-Methylenedioxymethamphetamine (MDMA) is a widely abused illicit drug. In animals, high-dose administration of MDMA produces deficits in serotonin (5-HT) neurons (e.g., depletion of forebrain 5-HT) that have been interpreted as neurotoxicity. Whether such 5-HT deficits reflect neuronal damage is a matter of ongoing debate. OBJECTIVE: The present paper reviews four specific issues related to the hypothesis of MDMA neurotoxicity in rats: (1) the effects of MDMA on monoamine neurons, (2) the use of “interspecies scaling” to adjust MDMA doses across species, (3) the effects of MDMA on established markers of neuronal damage, and (4) functional impairments associated with MDMA-induced 5-HT depletions. RESULTS: MDMA is a substrate for monoamine transporters, and stimulated release of 5-HT, NE, and DA mediates effects of the drug. MDMA produces neurochemical, endocrine, and behavioral actions in rats and humans at equivalent doses (e.g., 1–2 mg/kg), suggesting that there is no reason to adjust doses between these species. Typical doses of MDMA causing long-term 5-HT depletions in rats (e.g., 10–20 mg/kg) do not reliably increase markers of neurotoxic damage such as cell death, silver staining, or reactive gliosis. MDMA-induced 5-HT depletions are accompanied by a number of functional consequences including reductions in evoked 5-HT release and changes in hormone secretion. Perhaps more importantly, administration of MDMA to rats induces persistent anxiety-like behaviors in the absence of measurable 5-HT deficits. CONCLUSIONS: MDMA-induced 5-HT depletions are not necessarily synonymous with neurotoxic damage. However, doses of MDMA which do not cause long-term 5-HT depletions can have protracted effects on behavior, suggesting even moderate doses of the drug may pose risks

    Loss-of-function fibroblast growth factor receptor-2 mutations in melanoma

    Get PDF
    We report that 10% of melanoma tumors and cell lines harbor mutations in the fibroblast growth factor receptor 2 (FGFR2) gene. These novel mutations include three truncating mutations and 20 missense mutations occurring at evolutionary conserved residues in FGFR2 as well as among all four FGFRs. The mutation spectrum is characteristic of those induced by UV radiation. Mapping of these mutations onto the known crystal structures of FGFR2 followed by in vitro and in vivo studies show that these mutations result in receptor loss of function through several distinct mechanisms, including loss of ligand binding affinity, impaired receptor dimerization, destabilization of the extracellular domains, and reduced kinase activity. To our knowledge, this is the first demonstration of loss-of-function mutations in a class IV receptor tyrosine kinase in cancer. Taken into account with our recent discovery of activating FGFR2 mutations in endometrial cancer, we suggest that FGFR2 may join the list of genes that play context-dependent opposing roles in cancer

    Prevalence of germline BAP1, CDKN2A, and CDK4 mutations in an australian population-based sample of cutaneous melanoma cases

    No full text
    Mutations in Cyclin-Dependent Kinase Inhibitor 2A (CDKN2A) and Cyclin-Dependent Kinase 4 (CDK4) contribute to susceptibility in approximately 40% of high-density cutaneous melanoma (CMM) families and about 2% of unselected CMM cases. BRCA-1 associated protein-1 (BAP1) has been more recently shown to predispose to CMM and uveal melanoma (UMM) in some families; however, its contribution to CMM development in the general population is unreported. We sought to determine the contribution of these genes to CMM susceptibility in a population-based sample of cases from Australia. We genotyped 1,109 probands from Queensland families and found that approximately 1.31% harbored mutations in CDKN2A, including some with novel missense mutations (p.R22W, p.G35R and p.I49F). BAP1 missense variants occurred in 0.63% of cases but no CDK4 variants were observed in the sample. This is the first estimate of the contribution of BAP1 and CDK4 to a population-based sample of CMM and supports the previously reported estimate of CDKN2A germline mutation prevalence
    corecore