861 research outputs found
Targeting the Ataxia Telangiectasia Mutated-null Phenotype in Chronic Lymphocytic Leukemia with Pro-oxidants
Inactivation of the Ataxia Telangiectasia Mutated gene in chronic lymphocytic leukemia results in resistance to p53-dependent apoptosis and inferior responses to treatment with DNA damaging agents. Hence, p53-independent strategies are required to target Ataxia
Telangiectasia Mutated-deficient chronic lymphocytic leukemia. As Ataxia Telangiectasia Mutated has been implicated in redox homeostasis, we investigated the effect of the Ataxia Telangiectasia Mutated-null chronic lymphocytic leukemia genotype on cellular responses to
oxidative stress with a view to therapeutic targeting. We found that in comparison to Ataxia Telangiectasia Mutated-wild type chronic lymphocytic leukemia, pro-oxidant treatment of Ataxia Telangiectasia Mutated-null cells led to reduced binding of NF-E2 p45-related factor-2 to antioxidant response elements and thus decreased expression of target genes. Furthermore, Ataxia Telangiectasia Mutated-null chronic lymphocytic leukemia cells contained lower levels of antioxidants and elevated mitochondrial reactive oxygen species. Consequently, Ataxia Telangiectasia Mutated-null chronic lymphocytic leukemia, but not tumours with 11q deletion or TP53 mutations, exhibited differentially increased sensitivity to pro-oxidants both in vitro and in vivo. We found that cell death was mediated by a p53- and caspase-independent mechanism associated with apoptosis inducing factor activity. Together, these data suggest that defective redox-homeostasis represents an attractive therapeutic target for Ataxia Telangiectasia Mutated-null chronic lymphocytic leukemia
Mental states as macrostates emerging from brain electrical dynamics
Psychophysiological correlations form the basis for different medical and scientific disciplines, but the nature of this relation has not yet been fully understood. One conceptual option is to understand the mental as “emerging” from neural processes in the specific sense that psychology and physiology provide two different descriptions of the same system. Stating these descriptions in terms of coarser- and finer-grained system states (macro- and microstates), the two descriptions may be equally adequate if the coarse-graining preserves the possibility to obtain a dynamical rule for the system. To test the empirical viability of our approach, we describe an algorithm to obtain a specific form of such a coarse-graining from data, and illustrate its operation using a simulated dynamical system. We then apply the method to an electroencephalographic recording, where we are able to identify macrostates from the physiological data that correspond to mental states of the subject
A mitochondria-targeted mass spectrometry probe to detect glyoxals: implications for diabetes
The glycation of protein and nucleic acids that occurs as a consequence of hyperglycaemia disrupts cell function and contributes to many pathologies, including those associated with diabetes and aging. Intracellular glycation occurs following the generation of the reactive 1,2-dicarbonyls methylglyoxal and glyoxal and disruption to mitochondrial function is associated with hyperglycemia. However, the contribution of these reactive dicarbonyls to mitochondrial damage in pathology is unclear due to uncertainties about their levels within mitochondria in cells and in vivo. To address this we have developed a mitochondria-targeted reagent (MitoG) designed to assess the levels of mitochondrial dicarbonyls within cells. MitoG comprises a lipophilic triphenylphosphonium cationic function, which directs the molecules to mitochondria within cells and an o-phenylenediamine moiety that reacts with dicarbonyls to give distinctive and stable products. The extent of accumulation of these diagnostic heterocyclic products can be readily and sensitively quantified by liquid chromatography-tandem mass spectrometry (LC-MS/MS), enabling changes to be determined. Using the MitoG-based analysis we assessed the formation of methylglyoxal and glyoxal in response to hyperglycaemia in cells in culture and in the Akita mouse model of diabetes in vivo. These findings indicated that the levels of methylglyoxal and glyoxal within mitochondria increase during hyperglycaemia in both cells and in vivo, suggesting that they can contribute to the pathological mitochondrial dysfunction that occurs in diabetes and aging
Sherman, Shakers, and Shenanigans
The first 122 pages of this book relate to Bulloch County and form Book 10: Readings in Bulloch County History. The remainder comprise the Southern Folkways Journal Review No. 3, and relate to Southeast Georgia and to the Southeastern region of the United States. The first collection begins with a poem by Dr. John Ransom Lewis, followed by three articles on Dan Bland and the biographies of prominent African American citizens. Also included are two articles on the Hardy Moore family, student papers on vanishing Bulloch County communities, information on Joseph Jackson, articles on three local churches, and the Muster Roll of Toombs Guards. The second section of this book begins with an article on Western Shakers by Dr. Dale Covington, followed by “Hostau Reminisces,” and several articles on the Cherokee and the Lumbee Indians.https://digitalcommons.georgiasouthern.edu/bchs-pubs/1033/thumbnail.jp
Mitochondrial Genetic Background Modulates Bioenergetics and Susceptibility to Acute Cardiac Volume Overload
Dysfunctional bioenergetics has emerged as a key feature in many chronic pathologies such as diabetes and cardiovascular disease. This has led to the mitochondrial paradigm in which it has been proposed that mtDNA sequence variation contributes to disease susceptibility. In the present study we show a novel animal model of mtDNA polymorphisms, the MNX (mitochondrial–nuclear exchange) mouse, in which the mtDNA from the C3H/HeN mouse has been inserted on to the C57/BL6 nuclear background and vice versa to test this concept. Our data show a major contribution of the C57/BL6 mtDNA to the susceptibility to the pathological stress of cardiac volume overload which is independent of the nuclear background. Mitochondria harbouring the C57/BL6J mtDNA generate more ROS (reactive oxygen species) and have a higher mitochondrial membrane potential relative to those with C3H/HeN mtDNA, independent of nuclear background. We propose this is the primary mechanism associated with increased bioenergetic dysfunction in response to volume overload. In summary, these studies support the ‘mitochondrial paradigm’ for the development of disease susceptibility, and show that the mtDNA modulates cellular bioenergetics, mitochondrial ROS generation and susceptibility to cardiac stress
Facial-muscle weakness, speech disorders and dysphagia are common in patients with classic infantile Pompe disease treated with enzyme therapy
Classic infantile Pompe disease is an inherited generalized glycogen storage disorder caused by deficiency of lysosomal acid α-glucosidase. If left untreated, patients die before one year of age. Although enzyme-replacement therapy (ERT) has significantly prolonged lifespan, it has also revealed new aspects of the disease. For up to 11 years, we investigated the frequency and consequences of facial-muscle weakness, speech disorders and dysphagia in long-term survivors. Sequential photographs were used to determine the timing and severity of facial-muscle weakness. Using standardized articulation tests and fibreoptic endoscopic evaluation of swallowing, we investigated speech and swallowing function in a subset of patients. This study included 11 patients with classic infantile Pompe disease. Median age at the start of ERT was 2.4 months (range 0.1-8.3 months), and median age at the end of the study was 4.3 years (range 7.7 months −12.2 years). All patients developed facial-muscle weakness before the age of 15 months. Speech was studied in four patients. Articulation was disordered, with hypernasal resonance and reduced speech intelligibility in all four. Swallowing function was studied in six patients, the most important findings being ineffective swallowing with residues of food (5/6), penetration or aspiration (3/6), and reduced pharyngeal and/or laryngeal sensibility (2/6). We conclude that facial-muscle weakness, speech disorders and dysphagia are common in long-term survivors receiving ERT for classic infantile Pompe disease. To improve speech and reduce the risk for aspiration, early treatment by a speech therapist and regular swallowing assessments are recommended
The function of fear in institutional maintenance: Feeling frightened as an essential ingredient in haute cuisine
Fear is a common and powerful emotion that can regulate behaviour. Yet institutional scholars have paid limited attention to the function of fear in processes of institutional reproduction and stability. Drawing on an empirical study of elite chefs within the institution of haute cuisine, this article finds that the multifaceted emotion of fear characterised their experiences and served to sustain their institution. Chefs’ individual feelings of fear prompted conformity and a cognitive constriction, which narrowed their focus on to the precise reproduction of traditional practices whilst also limiting challenges to the norms underpinning the institution. Through fear work, chefs used threats and violence to connect individual experiences of fear to the violation of institutionalized rules, sustaining the conditions in which fear-driven maintenance work thrived. The study also suggests that fear is a normative element of haute cuisine in its own right, where the very experience and eliciting of fear preserved an essential institutional ingredient. In this way, emotions such as fear do not just accompany processes of institutionalization but can be intimately involved in the maintenance of institutions
Cultural theory and the dynamics of organizational change: the response of housing associations in London to the Housing Act 1988
The aim of this article is to consider the most effective way of conceptualizing a sector that has undergone radical change: the UK voluntary housing sector. The article considers existing accounts of housing associations and classifies these into five analytically distinct groups: practitioners, historical accounts, managerialist approaches, network theorists and institutionalist accounts. The main contention is that each of these is limited in explanatory potential, primarily due to their neglect of culture. This article proposes a more detailed framework for developing an understanding of the substantial changes affecting housing associations since the 1980s; that offered by "grid-group cultural theory". The article provides longitudinal qualitative data obtained from London housing associations to support the contention that organizational change can most usefully be understood by reference to the cultural themes of hierarchy and individualism. The article contends that cultural theory offers the opportunity to develop a systematic analysis that accounts for institutional history and organizational differentiation
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