341 research outputs found

    Ī±<sub>1L</sub>-adrenoceptors mediate contraction of human erectile tissue

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    Ī±1-adrenoceptor antagonists can impact upon sexual function and have potential in the treatment of erectile dysfunction. Human erectile tissue contains predominantly Ī±1A-adrenoceptors, and here we examined whether contractions of this tissue are mediated by the functional phenotype, the Ī±1L-adrenoceptor. Functional experiments using subtype selective agonists and antagonists, along with radioligand ([3H]tamsulosin) binding assays, were used to determine the Ī±1-adrenoceptor population. A61603, a Ī±1A-adrenoceptor agonist, was a full agonist with a potency 21-fold greater than that of noradrenaline. The Ī±1A- and Ī±1D-adrenoceptor antagonist tamsulosin antagonized noradrenaline responses with high affinity (pKDĀ =Ā 9.7Ā Ā±Ā 0.3), whilst BMY7378 (100Ā nM) (Ī±1D-adrenoceptor antagonist) failed to antagonize responses. In contrast, relatively low affinity estimates were obtained for both prazosin (pKDĀ =Ā 8.2Ā Ā±Ā 0.1) and RS17053 (pKDĀ =Ā 6.9Ā Ā±Ā 0.2), antagonists which discriminate between the Ī±1A- and Ī±1L-adrenoceptors. [3H]Tamsulosin bound with high affinity to the receptors of human erectile tissue (pKDĀ =Ā 10.3Ā Ā±Ā 0.1) with a receptor density of 28.1Ā Ā±Ā 1.4Ā fmolĀ mgāˆ’1 protein. Prazosin displacement of [3H]tamsulosin binding revealed a single homogenous population of binding sites with a relatively low affinity for prazosin (pKiĀ =Ā 8.9). Taken together these data confirm that the receptor mediating contraction in human erectile tissue has the pharmacological properties of the Ī±1L-adrenoceptor. Keywords: Erectile tissue, Ī±1-adrenoceptor subtypes, Ī±1L-adrenoceptor, Tamsulosin, Prazosi

    Critical appraisal of the role of davunetide in the treatment of progressive supranuclear palsy

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    Progressive supranuclear palsy (PSP) is a rare neurodegenerative disease characterized by the accumulation of tau protein aggregates in the basal ganglia, brainstem and cerebral cortex leading to rapid disease progression and death. The neurofibrillary tangles that define the neuropathology of PSP are comprised of aggregated 4R tau and show a well-defined distribution. Classically, PSP is diagnosed by symptoms that include progressive gait disturbance, early falls, vertical ophthalmoparesis, akinetic-rigid features, prominent bulbar dysfunction and fronto-subcortical dementia. There are currently no effective therapies for the treatment of this rapidly degenerating and debilitating disease. Davunetide is a novel neuroprotective peptide that is thought to impact neuronal integrity and cell survival through the stabilization of microtubules. Preclinical activity in models of tauopathy has been translated to clinical studies, demonstrating pharmacologic activity that has supported further development. Davunetideā€™s efficacy and tolerability are being tested in a placebo-controlled study in PSP patients, making it the most advanced drug candidate in this indication. This review examines the disease characteristics of PSP, the rationale for treating PSP with davunetide and assesses some of the challenges of clinical trials in this patient population

    Hepatic effects of tartrazine (E 102) after systemic exposure are independent of oestrogen receptor interactions in the mouse

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    Tartrazine is a food colour that activates the transcriptional function of the human oestrogen receptor alpha in an in vitro cell model. Since oestrogens are cholestatic, we hypothesised tartrazine will cause periportal injury to the liver in vivo. To test this hypothesis, tartrazine was initially administered systemically to mice resulting in a periportal recruitment of inflammatory cells, increased serum alkaline phosphatase activity and mild periportal fibrosis. To determine whether an oestrogenic effect may be a key event in this response, tartrazine, sulphonated metabolites and a food additive contaminant were screened for their ability to interact with murine oestrogen receptors. In all cases, there were no interactions as agonists or antagonists and further, no oestrogenicity was observed with tartrazine in an in vivo uterine growth assay. To examine the relevance of the hepatic effects of tartrazine to its use as a food additive, tartrazine was orally administered to transgenic NF-ĪŗB-Luc mice. Pre- and concurrent oral treatment with alcohol was incorporated given its potential to promote gut permeability and hepatic inflammation. Tartrazine alone induced NF- ĪŗB activities in the colon and liver but there was no periportal recruitment of inflammatory cells or fibrosis. Tartrazine, its sulphonated metabolites and the contaminant inhibited sulphotransferase activities in murine hepatic S9 extracts. Given the role of sulfotransferases in bile acid excretion, the initiating event giving rise to periportal inflammation and subsequent hepatic pathology through systemic tartrazine exposure is therefore potentially associated an inhibition of bile acid sulphation and excretion and not on oestrogen receptor-mediated transcriptional function. However, these effects were restricted to systemic exposures to tartrazine and did not occur to any significant effect after oral exposure

    Precision Antifungal Treatment Significantly Extends Voice Prosthesis Lifespan in Patients Following Total Laryngectomy

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    Indwelling silicone valves called voice prostheses (VPs) are the gold standard for speech rehabilitation in patients with laryngeal cancer following total laryngectomy. Reported VP lifespans amongst these patients are highly variable but when devices fail patients experience loss of voice and an increase risk of chest infection. Early failure of VP is a current clinical concern that is associated with regular hospital visits, reduced quality of life and associated medical cost. Poly-microbial biofilms comprised of both bacterial and fungal microorganisms readily colonize VPs and are linked to loss of device performance and its early failure in addition to providing a reservoir for potential infection. Our detailed analysis of poly-microbial biofilm composition on 159 early failing VPs from 48 total laryngectomy patients confirmed Candida albicans as the predominant fungal species and Staphylococcus aureus as the most common bacterial colonizer within our patient cohort. Using a combination of microbiological analysis, patient data and a high-throughput antifungal test assay mimicking in vivo conditions we established an evidence based precision antifungal treatment approach to VP management. Our approach has allowed us to implement a personalized VP management pathway, which increases device in situ lifespan by an average of 270%. Our study represents a significant step forward in both our understanding of the cause of VP failure and a new effective treatment pathway that offers tangible benefit to patients

    Two Distinctly HLA-Associated Contiguous Linear Epitopes Uniquely Expressed Within the Islet Antigen 2 Molecule Are Major Autoantibody Epitopes of the Diabetes-Specific Tyrosine Phosphatase-Like Protein Autoantigens

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    AbstractThe related tyrosine phosphatase-like proteins islet Ag (IA)-2 and IA-2Ī² are autoantigens of type 1 diabetes in humans. Autoantibodies are predominantly against IA-2, and IA-2-specific epitopes are major autoantibody targets. We used the close homology of IA-2 and IA-2Ī² to design chimeras and mutants to identify humoral IA-2-specific epitopes. Two major IA-2 epitopes that are absent from the related autoantigens IA-2Ī² and IA-2Ī” 13 splice variant ICA512.bdc were found contiguous to each other within IA-2 juxtamembrane amino acids 611ā€“620 (epitope JM1) and 621ā€“630 (epitope JM2). JM1 and JM2 are recognized by sera from 67% of patients with IA-2 Abs, and relatives of patients with type 1 diabetes having Abs to either JM epitope had a &gt;50% risk for developing type 1 diabetes within 6 years, even in the absence of diabetes-associated HLA genotypes. Remarkably, the presence of Abs to one of these two epitopes was mutually exclusive of the other; JM2 Abs and not JM1 Abs were found in relatives with HLA DR3/4, DR4/13, or DR1/4 genotypes; and the binding of autoantibodies to the JM2 epitope, but not the JM1 epitope, markedly affected proteolysis of IA-2. This is a unique demonstration of HLA-associated B cell responses to epitopes within a single autoantigen in humans and is consistent with modification of Ag processing by specific Ab-influencing peptide presentation by HLA molecules

    Development of an in-house ELISA to detect anti-HPV16-L1 antibodies in serum and dried blood spots

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    Measuring anti-HPV antibody levels is important for surveillance of the immunological response to both natural infection and vaccination. Here, an ELISA test for measurement of HPV-16L1 antibodies was developed and validated in sera and dried blood spots. An in-house ELISA was developed for measuring anti-HPV-16L1 IgA and IgG levels. The assay was standardized against WHO international standard serum and validated on serum, dried blood spots and cervical liquid based cytology samples from women attending colposcopy clinics in Scotland. Antibody avidity index was also measured in serum samples. The average HPV 16-L1 specific IgG and IgA levels measured in sera, in women attending a routine colposcopy service were 7.3 units/ml and 8.1 units/ml respectively. Significant correlations between serum and dried blood spot eluates for both IgG and IgA were observed indicating that the latter serve as a credible proxy for antibody levels. Average IgG Avidity Index was 35% (95% CI 25%-45%) suggesting previous, historical challenge with natural infection. This ELISA has potential for use in epidemiological and field studies of antibody prevalence and if coupled with avidity measurement may be of use in individual case monitoring of vaccine responses and failures

    Adenoma development in familial adenomatous polyposis andMUTYH-associated polyposis: somatic landscape and driver genes

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    Familial adenomatous polyposis (FAP) and MUTYHā€associated polyposis (MAP) are inherited disorders associated with multiple colorectal adenomas that lead to a very high risk of colorectal cancer. The somatic mutations that drive adenoma development in these conditions have not been investigated comprehensively. In this study we performed analysis of paired colorectal adenoma and normal tissue DNA from individuals with FAP or MAP, sequencing 14 adenoma whole exomes (eight MAP, six FAP), 55 adenoma targeted exomes (33 MAP, 22 FAP) and germline DNA from each patient, and a further 63 adenomas by capillary sequencing (41 FAP, 22 MAP). With these data we examined the profile of mutated genes, the mutational signatures and the somatic mutation rates, observing significant diversity in the constellations of mutated driver genes in different adenomas, and lossā€ofā€function mutations in WTX (9%; p < 9.99eā€06), a gene implicated in regulation of the WNT pathway and p53 acetylation. These data extend our understanding of the early events in colorectal tumourigenesis in the polyposis syndromes. Ā© 2015 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland

    Microstructural characterisation and mechanical properties of Ti-5Al-5V-5Mo-3Cr built by wire and arc additive manufacture

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    The as-deposited microstructure and mechanical properties of the near-Ī² titanium alloy Ti-5Al-5V-5Mo-3Cr (Ti-5553) produced by wire-arc additive manufacture (WAAM) were investigated, to understand its microstructural evolution under WAAM deposition conditions and to establish correlations between the microstructure features formed and the thermal cycles experienced during deposition. The ā€˜as-depositedā€™ Ti-5553 WAAM material exhibited higher tensile strengths than other as-deposited additively manufactured Ti-5553 deposits previously reported in the literature, but had significant anisotropy in elongation, as a consequence of the coarse and columnar Ī²-grain structure that formed on solidification, which exhibited a strong {001}Ī²āŸØ001āŸ©Ī² cube texture. The multiple reheating cycles, inherent to the WAAM process, were recorded using a novel ā€˜harpoonā€™ thermocouple technique, and the Ī± precipitation evolution was related to the thermal history. Electron probe microanalysis chemical maps revealed significant solute microsegregation during solidification, which influenced the subsequent precipitation due to its effect on the local Ī²-phase stability. As each layer experienced more reheating cycles, the microstructure evolution could be ā€˜time resolvedā€™ and the Ī± laths were found to precipitate in a specific sequence of nucleation sites, starting at the Ī²-grain boundaries and then inter-dendritically, where there was lower matrix Ī² stability. However, after the reheating peak temperature was insufficiently high to have any further effect, the microstructure consisted of a relatively uniform distribution of Ī± laths

    Exploring childrenā€™s perspectives on the welfare needs of pet animals

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    This work was supported by the Department for Environment, Food and Rural Affairs (grant number AW1404).Children are increasingly viewed as important recipients of eduational interventions to improve animal welfare, yet research examining their perspectives is lacking, particularly within the UK. Helping children to care appropriately for animals depends, not least, on an ability to understand the needs of different species and correctly identify cues given by the animal that indicate its welfare state. This study began to explore: (a) childrenā€™s perceptions of welfare needs, focusing on four common pet animals; (b) influences on the development of knowledge; (c) beliefs about whether or not (all) animals are sentient, and (d) their confidence in identifying when their own pets are in need. Fourteen focus groups were carried out with 53 children aged 7 to 13 years. Findings highlighted an affirmative response that animals have feelings (dogs especially), albeit with doubts about this applying universally. There was wide variation in childrenā€™s knowledge of welfare needs, even among owners of the animal in question. Conversely, some children lacked confidence in spite of the extensive knowledge they had developed through direct experience. An important finding was a perceived difficulty in identifying the needs of particular species or specific types of need in their own pets. Fitting well with a recent emphasis on ā€œpositive welfare,ā€ children felt that many animals need demonstrative love and attention, especially cats and dogs. While there is clearly scope for educating children about common needs and cues that indicate animalsā€™ welfare state, other areas pose a greater challenge. Emotional connection seems important in the development of extensive knowledge and concern for welfare. Accordingly, animals that do not possess the kind of behavioral repertoire that is easy to interpret or allows for a perceived sense of reciprocity are possibly at risk of negative welfare experiences.PostprintPeer reviewe
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