14 research outputs found

    Secluded Dark Matter Coupled to a Hidden CFT

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    Models of secluded dark matter offer a variant on the standard WIMP picture and can modify our expectations for hidden sector phenomenology and detection. In this work we extend a minimal model of secluded dark matter, comprised of a U(1)'-charged dark matter candidate, to include a confining hidden-sector CFT. This provides a technically natural explanation for the hierarchically small mediator-scale, with hidden-sector confinement generating m_{gamma'}>0. Furthermore, the thermal history of the universe can differ markedly from the WIMP picture due to (i) new annihilation channels, (ii) a (potentially) large number of hidden-sector degrees of freedom, and (iii) a hidden-sector phase transition at temperatures T << M_{dm} after freeze out. The mediator allows both the dark matter and the Standard Model to communicate with the CFT, thus modifying the low-energy phenomenology and cosmic-ray signals from the secluded sector.Comment: ~50p, 8 figs; v2 JHEP versio

    Nr2e3 is a Genetic Modifier That Rescues Retinal Degeneration and Promotes Homeostasis in Multiple Models of Retinitis Pigmentosa

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    Recent advances in viral vector engineering, as well as an increased understanding of the cellular and molecular mechanism of retinal diseases, have led to the development of novel gene therapy approaches. Furthermore, ease of accessibility and ocular immune privilege makes the retina an ideal target for gene therapies. In this study, the nuclear hormone receptor gene Nr2e3 was evaluated for efficacy as broad-spectrum therapy to attenuate early to intermediate stages of retinal degeneration in five unique mouse models of retinitis pigmentosa (RP). RP is a group of heterogenic inherited retinal diseases associated with over 150 gene mutations, affecting over 1.5 million individuals worldwide. RP varies in age of onset, severity, and rate of progression. In addition, ~40% of RP patients cannot be genetically diagnosed, confounding the ability to develop personalized RP therapies. Remarkably, Nr2e3 administered therapy resulted in reduced retinal degeneration as observed by increase in photoreceptor cells, improved electroretinogram, and a dramatic molecular reset of key transcription factors and associated gene networks. These therapeutic effects improved retinal homeostasis in diseased tissue. Results of this study provide evidence that Nr2e3 can serve as a broad-spectrum therapy to treat multiple forms of RP

    The Leber Congenital Amaurosis-Linked Protein AIPL1 and Its Critical Role in Photoreceptors

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    Mutations in the photoreceptor/pineal-expressed gene, aryl hydrocarbon receptor-interacting protein-like 1 (AIPL1), are mainly associated with autosomal recessive Leber congenital amaurosis (LCA), the most severe form of inherited retinopathy that occurs in early childhood. AIPL1 functions as a photoreceptor-specific molecular co-chaperone that interacts specifically with the molecular chaperones HSP90 and HSP70 to facilitate the correct folding and assembly of the retinal cGMP phosphodiesterase (PDE6) holoenzyme. The absence of AIPL1 leads to a dramatic degeneration of rod and cone cells and a complete loss of any light-dependent electrical response. Here we review the important role of AIPL1 in photoreceptor functionality

    Crianças com fissura isolada de palato: desempenho nos testes de processamento auditivo Cleft palate children: performance in auditory processing tests

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    Muitas crianças com transtorno de processamento auditivo têm uma prevalência alta de otite média, alteração na orelha média de grande ocorrência na população com fissura labiopalatina. OBJETIVO: Verificar o desempenho de crianças com fissura isolada de palato (FP) em testes do processamento auditivo. Estudo prospectivo. MATERIAL E MÉTODO: Vinte crianças (7 a 11 anos) com FP foram submetidas aos testes de localização sonora (LS), memória para sons verbais (MSSV) e não-verbais em seqüência (MSSNV), Fusão Auditiva-Revisado (AFT-R), Teste Pediátrico de Inteligibilidade de Fala/Sentenças Sintéticas (PSI/SSI), Dissílabos alternados (SSW) e Dicótico de dígitos (DD). O desempenho das crianças nos testes foi classificado em ruim e bom. RESULTADOS: Não houve diferença estatística entre os gêneros e orelhas. Os valores médios obtidos foram 2,16, 2,42, 4,37, 60,50ms, de 40,71 a 67,33%, 96,25 a 99,38%, 73,55 a 73,88% e 58,38 a 65,47%, respectivamente, para os testes MSSNV, MSSV, LS, AFT-R, PSI/SSI com mensagem competitiva ipsilateral (PSI/SSIMCI) e contralateral (PSI/SSI/MCC), DD e SSW. CONCLUSÃO: Uma alta porcentagem de crianças demonstrou seus piores desempenhos nos testes AFT-R, DD, SSW e no teste PSI/SSIMCI. Os melhores desempenhos ocorreram nos testes de localização sonora, memória seqüencial para sons não verbais e verbais e para PSI/SSIMCC.<br>Many children with auditory processing disorders have a high prevalence of otitis media, a middle ear alterations greatly prevalent in children with palatine and lip clefts. AIM: to check the performance of children with palate cleft alone (PC) in auditory processing tests. Prospective study. MATERIALS AND METHODS: twenty children (7 to 11 years) with CP were submitted to sound location tests (SL), memory for verbal sounds (MSSV) and non verbal sounds in sequence (MSSNV), Revised auditory fusion (AFT-R), Pediatric test of speech intelligibility/synthetic sentences (PSI/SSI), alternate disyllables (SSW) and digit dichotic (DD). The children performances in the tests were classified in bad and good. RESULTS: there was no statistically significant difference between genders and ears. The average values obtained were 2.16, 2.42, 4.37, 60.50ms; 40.71 to 67.33%; 96.25 to 99.38%; 73.55 to 73.88% and 58.38 to 65.47% respectively for the MSSNV, MSSV, LS, AFT-R, PSI/SSI tests with ipsilateral (PSI/SSIMCI) and contralateral (PSI/SSI/MCC) competitive message, DD and SSW tests. CONCLUSION: a high percentage of children showed worse results in the AFT-R, DD, SSW tests and in the PSI/SSIMCI tests. The best performances happened in the sound location tests, verbal and non-verbal sounds for sequential memory and for PSI/SSIMCC tests

    Activation and Regulation of the Nitric Oxide-Cyclic GMP Signal Transduction Pathway by Oxidative Stress

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    FKBP (FK506 Binding Protein)

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    In the 70s, after a decade from the purification of cyclosporine, a selective immunosuppressant agent and potent tool in transplantation medicine, a novel molecule was purified from bacteria Streptomyces tsukubaensis. This molecule, called FK506, showed the same selective immunosuppressant action as cyclosporine but was 10 to 100 fold more potent. In an attempt to clarify the molecular mechanism through which the new drug exerted such a selective effect on T-cells activation, two laboratories identified the cytosolic receptor for FK506. This so-called FK506 binding protein (FKBP) was purified from bovine thymus, human spleen, and Jurkat T-cell line. The isolated FKBP had an approximate molecular mass of 14 kDa and showed an isomerase activity similar to the recently purified cyclosporine-binding protein, cyclophilin, but, it was inhibited by FK506 and rapamycin but not cyclosporine. The subsequent cloning of FKBP gene revealed that FKBP and cyclophilin had dissimilar sequences in spite of their common enzymatic activity. The identified FKBP gene encoded for a protein of 108 aminoacids with a relative molecular mass of 11,819. For this reason, the progenitor of this nascent class of proteins was later known as FKBP12. The subsequent studies showed that FKBP12 was just a member of a ubiquitous and evolutionarily conserved sub-family of proteins which differ from each other in their molecular weight and structure. All FKBPs share a highly conserved domain, termed “FK-12 like domain”, capable of binding to FK506 and exerting isomerase properties, i.e. interconversion from cis-to-trans and trans-to-cis of peptide bonds involving proline, on protein substrates. A schematic historical background of the 17 FKBPs so far identified is shown. A general overview of FKBP structure, function and eventually associated disease is given in this monograph, with the order of proteins following the chronology of discovery

    Signaling by Rod and Cone Photoreceptors: Opsin Properties, G-protein Assembly, and Mechanisms of Activation

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