408 research outputs found
Prevalence of surgical procedures at symptomatic onset of prion disease
This case-control study examines the frequency of invasive procedures at the onset of prion disease symptoms to determine the scope of the risk of contamination to future patients
Racial and Ethnic Differences in Individuals with Sporadic Creutzfeldt-Jakob Disease in the United States of America
BACKGROUND: Little is known about racial and ethnic differences in individuals with sporadic Creutzfeldt-Jakob disease (sCJD). The authors sought to examine potential clinical, diagnostic, genetic, and neuropathological differences in sCJD patients of different races/ethnicities. METHODOLOGY/PRINCIPAL FINDINGS: A retrospective study of 116 definite and probable sCJD cases from Johns Hopkins and the Department of Veterans Affairs Healthcare Systems was conducted that examined differences in demographic, clinical, diagnostic, genetic, and neuropathological characteristics among racial/ethnic groups. Age at disease onset differed among racial/ethnic groups. Non-Hispanic Whites had a significantly older age at disease onset compared to the other groups (65 vs. 60, p = 0.036). Non-Whites were accurately diagnosed more rapidly than Whites (p = 0.008) and non-Hispanic Whites were more likely to have normal appearing basal ganglia on brain magnetic resonance imaging (MRI) compared to minorities (p = 0.02). Whites were also more likely to undergo post-mortem evaluation compared to non-Whites (p = 0.02). CONCLUSIONS/SIGNIFICANCE: Racial/ethnic groups affected by sCJD demonstrated differences in age at disease onset, time to correct diagnosis, clinical presentation, and diagnostic test results. Whites were more likely to undergo autopsy compared to non-Whites. These results have implications in regards to case ascertainment, diagnosis, and surveillance of sCJD and possibly other human prion diseases
Gerstmann-StrƤussler-Scheinker disease subtypes efficiently transmit in bank voles as genuine prion diseases.
Gerstmann-StrƤussler-Scheinker disease (GSS) is an inherited neurodegenerative disorder associated with mutations in the prion protein gene and accumulation of misfolded PrP with protease-resistant fragments (PrPres) of 6ā8ākDa
A point mutation in the murine Hem1 gene reveals an essential role for Hematopoietic Protein 1 in lymphopoiesis and innate immunity
Hem1 (Hematopoietic protein 1) is a hematopoietic cell-specific member of the Hem family of cytoplasmic adaptor proteins. Orthologues of Hem1 in Dictyostelium discoideum, Drosophila melanogaster, and Caenorhabditis elegans are essential for cytoskeletal reorganization, embryonic cell migration, and morphogenesis. However, the in vivo functions of mammalian Hem1 are not known. Using a chemical mutagenesis strategy in mice to identify novel genes involved in immune cell functions, we positionally cloned a nonsense mutation in the Hem1 gene. Hem1 deficiency results in defective F-actin polymerization and actin capping in lymphocytes and neutrophils caused by loss of the Rac-controlled actin-regulatory WAVE protein complex. T cell development is disrupted in Hem1-deficient mice at the CD4āCD8ā (double negative) to CD4+CD8+ (double positive) cell stages, whereas T cell activation and adhesion are impaired. Hem1-deficient neutrophils fail to migrate in response to chemotactic agents and are deficient in their ability to phagocytose bacteria. Remarkably, some Rac-dependent functions, such as Th1 differentiation and nuclear factor ĪŗB (NF-ĪŗB)ādependent transcription of proinflammatory cytokines proceed normally in Hem1-deficient mice, whereas the production of Th17 cells are enhanced. These results demonstrate that Hem1 is essential for hematopoietic cell development, function, and homeostasis by controlling a distinct pathway leading to cytoskeletal reorganization, whereas NF-ĪŗBādependent transcription proceeds independently of Hem1 and F-actin polymerization
A novel mechanism of phenotypic heterogeneity in Creutzfeldt-Jakob disease
One of remarkable features of sporadic Creutzfeldt-Jakob disease (sCJD) is the great phenotypic variability. Understanding the molecular basis of this variability has important implications for the development of therapeutic approaches. It is well established that, in many cases, phenotypic heterogeneity of sCJD is under control of two determinants: the genotype at the methionine (M)/valine (V) polymorphic codon 129 of the human prion protein gene and the type, 1 or 2, of the pathogenic and disease-related form of the prion protein, PrPD. However, this scenario fails to explain the existence of distinct heterozygous sCJDMV2 subtypes, where heterogeneity occurs without any variation of the 129 allotype and PrPD type. One of these subtypes, denoted sCJDMV2C, associated with PrPD type 2, is characterized by widespread spongiform degeneration of the cerebral cortex (C). The second variant, denoted sCJDMV2K, features prominent deposition of PrPD amyloid forming kuru type (K) plaques. Here we used a mass spectrometry based approach to test the hypothesis that phenotypic variability within the sCJDMV2 subtype is at least partly determined by the abundance of 129āM and 129āV polymorphic forms of proteinase K-resistant PrPD (resPrPD). Consistent with this hypothesis, our data demonstrated a strong correlation of the MV2C and MV2K phenotypes with the relative populations of protease-resistant forms of the pathogenic prion proteins, resPrPD-129āM and resPrPD-129āV, where resPrPD-129āM dominated in the sCJDMV2C variant and resPrPD-129āV in the sCJDMV2K variant. This finding suggests an important, previously unrecognized mechanism for phenotypic determination in human prion diseases
Phenotypic diversity of genetic CreutzfeldtāJakob disease: a histo-molecular-based classification
The Genomics of Disulfide Bonding and Protein Stabilization in Thermophiles
Thermophilic organisms flourish in varied high-temperature environmental niches that are deadly to other organisms. Recently, genomic evidence has implicated a critical role for disulfide bonds in the structural stabilization of intracellular proteins from certain of these organisms, contrary to the conventional view that structural disulfide bonds are exclusively extracellular. Here both computational and structural data are presented to explore the occurrence of disulfide bonds as a protein-stabilization method across many thermophilic prokaryotes. Based on computational studies, disulfide-bond richness is found to be widespread, with thermophiles containing the highest levels. Interestingly, only a distinct subset of thermophiles exhibit this property. A computational search for proteins matching this target phylogenetic profile singles out a specific protein, known as protein disulfide oxidoreductase, as a potential key player in thermophilic intracellular disulfide-bond formation. Finally, biochemical support in the form of a new crystal structure of a thermophilic protein with three disulfide bonds is presented together with a survey of known structures from the literature. Together, the results provide insight into biochemical specialization and the diversity of methods employed by organisms to stabilize their proteins in exotic environments. The findings also motivate continued efforts to sequence genomes from divergent organisms
Geography and the Paris Academy of Sciences: politics and patronage in early 18th-century France
This essay considers the politics and patronage of geography in early-modern France. It examines how the Paris Academy of Sciences, widely acknowledged as the 18th centuryās pre-eminent scientific society, came to recognise geography as an independent science in 1730, a century before the establishment of the first geographical societies. Although the Academy was centrally concerned with cartography from its inception in 1666, it initially afforded no official status to geography, which was viewed either as a specialised form of historical inquiry or as a minor component within the hegemonic science of astronomy. The rise of Newtonian mathematics and the associated controversy about the shape of the earth challenged the Academyās epistemological foundations and prompted a debate about the educational and political significance of geography as a scientific practice. The death in 1726 of Guillaume Delisle, a prominent Academy astronomer-cartographer and a popular geography tutor to the young Louis XV, led to a spirited campaign to elect Philippe Buache, Delisleās protļæ½egļæ½e, to a new Academy position as a geographer rather than an astronomer. The campaign emphasised the social and political utility of geography, though the Academyās decision to recognise this new and distinctively modern science was ultimately facilitated by traditional networks of patronage within the French Royal Court
The Golden Rule:Interfaith Peacemaking and the Charter for Compassion
The Charter for Compassion has been signed by over two million people from around the world and partnered with hundreds of interfaith organizations and cities seeking to put into practice the Golden Rule, common to the main faith traditions, of doing unto others as you would be done by. This article sets the Charter within the context of a post secular international society and faith-based diplomacy, in which religious interreligious initiatives emerge as serious, rather than peripheral, actors in developing sustainable peace making through bottom-up approaches. The article critically engages with the Charter's claim that āany interpretation of scripture that breeds violence, hatred or disdain is illegitimateā while accepting that peaceful interpretations of scriptures are helpful to peace processes where religious actors are involved. The article explores the claims of the Charter for Compassion International as they seek to make peace through compassion, before concluding that the Charter for Compassion is a long-term project aimed at changing hearts and minds but has had limited substantive impact to date
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