149 research outputs found

    Non-specific binding of antibodies in immunohistochemistry: fallacies and facts

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    The current protocols for blocking background staining in immunohistochemistry are based on conflicting reports. Background staining is thought to occur as a result of either non-specific antibody (Ab) binding to endogenous Fc receptors (FcRs) or a combination of ionic and hydrophobic interactions. In this study, cell and tissue samples were processed according to routine protocols either with or without a blocking step (goat serum or BSA). Surprisingly, no Abs in samples processed without a blocking step showed any propensity for non-specific binding leading to background staining, implying that endogenous FcRs do not retain their ability to bind the Fc portion of Abs after standard fixation. Likewise, we did not find any non-specific Ab binding ascribable to either ionic or hydrophobic interactions. We determined that traditionally used protein blocking steps are unnecessary in the immunostaining of routinely fixed cell and tissue samples

    Developing a self-management intervention to manage hypermobility spectrum disorders (HSD) and hypermobile Ehlers-Danlos syndrome (hEDS): An analysis informed by behaviour change theory

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    Purpose: Hypermobility Spectrum Disorders (HSD) and Hypermobile Ehlers-Danlos Syndrome (hEDS) are heritable connective tissue disorders associated with joint instability and pain, but with scant guidance for supporting patients. The aim was to determine recommendations for an HSD/hEDS self-management intervention. Materials and methods: Barriers to self-management were mapped onto the Theoretical Domains Framework (TDF) and Capability, Opportunity, Motivation-Behaviour (COM-B) model in a behavioural analysis. A modified Nominal Group Technique was used to prioritise behaviour change technique (BCT) interventions (n = 9 women). Results: Possible BCTs incorporated: Education: Incorporating self-help strategies, education to improve their knowledge of HSD/hEDS, and how to judge information about HSD/hEDS. Training: In activity pacing, assertiveness and communication skills, plus what to expect during pregnancy, when symptoms can worsen. Environmental restructuring and enablement: Support from occupational therapists to maintain independence at work and home. Modelled behaviour: That illustrates how other people with HSD/hEDS have coped with the psychosocial impact. Conclusions: This study is the first to apply theoretically-informed approaches to the management of HSD/hEDS. Participants indicated poor access to psychological support, occupational therapy and a lack of knowledge about HSD/hEDS. Future research should evaluate which intervention options would be most acceptable and feasible.Implications for rehabilitation Patients with Hypermobility Spectrum Disorders or Hypermobile Ehlers-Danlos Syndrome can be active partners in the co-design of behaviour change interventions. Behaviour change interventions should target psychological support and patient education, particularly patient information. Additional behaviour change interventions included environmental restructuring and enablement; adaptations to participants’ environment with input from occupational therapy. Participants were keen to suggest opportunities for behavioural modelling; positive fist-person modelling narratives, written by those with HSD/hEDS, which addressed how they coped with the psychosocial impact of their condition

    Lemierre's syndrome due to Klebsiella pneumoniae in a 63-year-old man with diabetes: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>Lemierre's syndrome was originally documented to be caused by <it>Fusobacterium necrophorum</it>. It is a very rare condition with a prevalence of one to 14.4 instances per million. Its presentation is varied, not only in composition but also in the infecting organism. Treatment with anticoagulants has been controversial and applied only on a case-by-case basis.</p> <p>Case presentation</p> <p>A 63-year-old Saudi man who had had uncontrolled diabetes mellitus for 47 years presented to our facility with a five-day history of swelling on the right side of his neck and fever. The swelling progressively increased in size and was associated with pain, dysphagia, odynophagia, change of voice ('hot potato voice'), and reduced appetite. Abscess content culture and sensitivity testing revealed <it>Klebsiella pneumoniae</it>. However, blood culture results were repeatedly negative. The abscess was incised and drained without any complication. Our patient was treated with clindamycin and cefuroxime. Warfarin was also administered concurrently for six weeks, for an isolated internal jugular vein thrombosis (IJV), with complete resolution of the thrombus. Normoglycemia was achieved and our patient was discharged after complete wound healing and the return of his biochemical parameters to normal.</p> <p>Conclusions</p> <p>Only two cases of Lemierre's syndrome in patients with diabetes due to <it>K. pneumoniae </it>have been reported previously. A review of the literature suggested that an association exists between deep neck infections due to <it>K. pneumoniae </it>and diabetes mellitus. The reasons for this association are still not clear. This poses a question as to whether diabetes mellitus specifically predisposes these patients to infection with this organism. It is suggested that clinicians should consider infectious agents other than <it>F. necrophorum </it>in the causation of Lemierre's syndrome, especially in patients with diabetes.</p

    Extragalactic Radio Continuum Surveys and the Transformation of Radio Astronomy

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    Next-generation radio surveys are about to transform radio astronomy by discovering and studying tens of millions of previously unknown radio sources. These surveys will provide new insights to understand the evolution of galaxies, measuring the evolution of the cosmic star formation rate, and rivalling traditional techniques in the measurement of fundamental cosmological parameters. By observing a new volume of observational parameter space, they are also likely to discover unexpected new phenomena. This review traces the evolution of extragalactic radio continuum surveys from the earliest days of radio astronomy to the present, and identifies the challenges that must be overcome to achieve this transformational change.Comment: To be published in Nature Astronomy 18 Sept 201

    Altered Neurocircuitry in the Dopamine Transporter Knockout Mouse Brain

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    The plasma membrane transporters for the monoamine neurotransmitters dopamine, serotonin, and norepinephrine modulate the dynamics of these monoamine neurotransmitters. Thus, activity of these transporters has significant consequences for monoamine activity throughout the brain and for a number of neurological and psychiatric disorders. Gene knockout (KO) mice that reduce or eliminate expression of each of these monoamine transporters have provided a wealth of new information about the function of these proteins at molecular, physiological and behavioral levels. In the present work we use the unique properties of magnetic resonance imaging (MRI) to probe the effects of altered dopaminergic dynamics on meso-scale neuronal circuitry and overall brain morphology, since changes at these levels of organization might help to account for some of the extensive pharmacological and behavioral differences observed in dopamine transporter (DAT) KO mice. Despite the smaller size of these animals, voxel-wise statistical comparison of high resolution structural MR images indicated little morphological change as a consequence of DAT KO. Likewise, proton magnetic resonance spectra recorded in the striatum indicated no significant changes in detectable metabolite concentrations between DAT KO and wild-type (WT) mice. In contrast, alterations in the circuitry from the prefrontal cortex to the mesocortical limbic system, an important brain component intimately tied to function of mesolimbic/mesocortical dopamine reward pathways, were revealed by manganese-enhanced MRI (MEMRI). Analysis of co-registered MEMRI images taken over the 26 hours after introduction of Mn^(2+) into the prefrontal cortex indicated that DAT KO mice have a truncated Mn^(2+) distribution within this circuitry with little accumulation beyond the thalamus or contralateral to the injection site. By contrast, WT littermates exhibit Mn^(2+) transport into more posterior midbrain nuclei and contralateral mesolimbic structures at 26 hr post-injection. Thus, DAT KO mice appear, at this level of anatomic resolution, to have preserved cortico-striatal-thalamic connectivity but diminished robustness of reward-modulating circuitry distal to the thalamus. This is in contradistinction to the state of this circuitry in serotonin transporter KO mice where we observed more robust connectivity in more posterior brain regions using methods identical to those employed here

    Ser/Thr/Tyr Protein Phosphorylation in the Archaeon Halobacterium salinarumβ€”A Representative of the Third Domain of Life

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    In the quest for the origin and evolution of protein phosphorylation, the major regulatory post-translational modification in eukaryotes, the members of archaea, the β€œthird domain of life”, play a protagonistic role. A plethora of studies have demonstrated that archaeal proteins are subject to post-translational modification by covalent phosphorylation, but little is known concerning the identities of the proteins affected, the impact on their functionality, the physiological roles of archaeal protein phosphorylation/dephosphorylation, and the protein kinases/phosphatases involved. These limited studies led to the initial hypothesis that archaea, similarly to other prokaryotes, use mainly histidine/aspartate phosphorylation, in their two-component systems representing a paradigm of prokaryotic signal transduction, while eukaryotes mostly use Ser/Thr/Tyr phosphorylation for creating highly sophisticated regulatory networks. In antithesis to the above hypothesis, several studies showed that Ser/Thr/Tyr phosphorylation is also common in the bacterial cell, and here we present the first genome-wide phosphoproteomic analysis of the model organism of archaea, Halobacterium salinarum, proving the existence/conservation of Ser/Thr/Tyr phosphorylation in the β€œthird domain” of life, allowing a better understanding of the origin and evolution of the so-called β€œNature's premier” mechanism for regulating the functional properties of proteins

    Transcriptome Analysis of Epithelial and Stromal Contributions to Mammogenesis in Three Week Prepartum Cows

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    Transcriptome analysis of bovine mammary development has provided insight into regulation of mammogenesis. However, previous studies primarily examined expression of epithelial and stromal tissues combined, and consequently did not account for tissue specific contribution to mammary development. Our objective was to identify differences in gene expression in epithelial and intralobular stromal compartments. Tissue was biopsied from non-lactating dairy cows 3 weeks prepartum, cut into explants and incubated for 2 hr with insulin and hydrocortisone. Epithelial and intralobular stromal tissues were isolated with laser capture microdissection. Global gene expression was measured with Bovine Affymetrix GeneChips, and data were preprocessed using RMA method. Moderated t-tests from gene-specific linear model analysis with cell type as a fixed effect showed more than 3,000 genes were differentially expressed between tissues (P<0.05; FDR<0.17). Analysis of epithelial and stromal transcriptomes using Database for Annotation, Visualization and Integrated Discovery (DAVID) and Ingenuity Pathways Analysis (IPA) showed that epithelial and stromal cells contributed distinct molecular signatures. Epithelial signatures were enriched with gene sets for protein synthesis, metabolism and secretion. Stromal signatures were enriched with genes that encoded molecules important to signaling, extracellular matrix composition and remodeling. Transcriptome differences also showed evidence for paracrine interactions between tissues in stimulation of IGF1 signaling pathway, stromal reaction, angiogenesis, neurogenesis, and immune response. Molecular signatures point to the dynamic role the stroma plays in prepartum mammogenesis and highlight the importance of examining the roles of cell types within the mammary gland when targeting therapies and studying mechanisms that affect milk production

    Just regionalisation: rehabilitating care for people with disabilities and chronic illnesses

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    BACKGROUND: Regionalised models of health care delivery have important implications for people with disabilities and chronic illnesses yet the ethical issues surrounding disability and regionalisation have not yet been explored. Although there is ethics-related research into disability and chronic illness, studies of regionalisation experiences, and research directed at improving health systems for these patient populations, to our knowledge these streams of research have not been brought together. Using the Canadian province of Ontario as a case study, we address this gap by examining the ethics of regionalisation and the implications for people with disabilities and chronic illnesses. The critical success factors we provide have broad applicability for guiding and/or evaluating new and existing regionalised health care strategies. DISCUSSION: Ontario is in the process of implementing fourteen Local Health Integration Networks (LHINs). The implementation of the LHINs provides a rare opportunity to address systematically the unmet diverse care needs of people with disabilities and chronic illnesses. The core of this paper provides a series of composite case vignettes illustrating integration opportunities relevant to these populations, namely: (i) rehabilitation and services for people with disabilities; (ii) chronic illness and cancer care; (iii) senior's health; (iv) community support services; (v) children's health; (vi) health promotion; and (vii) mental health and addiction services. For each vignette, we interpret the governing principles developed by the LHINs – equitable access based on patient need, preserving patient choice, responsiveness to local population health needs, shared accountability and patient-centred care – and describe how they apply. We then offer critical success factors to guide the LHINs in upholding these principles in response to the needs of people with disabilities and chronic illnesses. SUMMARY: This paper aims to bridge an important gap in the literature by examining the ethics of a new regionalisation strategy with a focus on the implications for people with disabilities and chronic illnesses across multiple sites of care. While Ontario is used as a case study to contextualize our discussion, the issues we identify, the ethical principles we apply, and the critical success factors we provide have broader applicability for guiding and evaluating the development of – or revisions to – a regionalised health care strategy
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