125 research outputs found
Carbonic anhydrase III (Car3) is not required for fatty acid synthesis and does not protect against high-fat diet induced obesity in mice
Carbonic anhydrases are a family of enzymes that catalyze the reversible condensation of water and carbon dioxide to carbonic acid, which spontaneously dissociates to bicarbonate. Carbonic anhydrase III (Car3) is nutritionally regulated at both the mRNA and protein level. It is highly enriched in tissues that synthesize and/or store fat: liver, white adipose tissue, brown adipose tissue, and skeletal muscle. Previous characterization of Car3 knockout mice focused on mice fed standard diets, not high-fat diets that significantly alter the tissues that highly express Car3. We observed lower protein levels of Car3 in high-fat diet fed mice treated with niclosamide, a drug published to improve fatty liver symptoms in mice. However, it is unknown if Car3 is simply a biomarker reflecting lipid accumulation or whether it has a functional role in regulating lipid metabolism. We focused our in vitro studies toward metabolic pathways that require bicarbonate. To further determine the role of Car3 in metabolism, we measured de novo fatty acid synthesis with in vitro radiolabeled experiments and examined metabolic biomarkers in Car3 knockout and wild type mice fed high-fat diet. Specifically, we analyzed body weight, body composition, metabolic rate, insulin resistance, serum and tissue triglycerides. Our results indicate that Car3 is not required for de novo lipogenesis, and Car3 knockout mice fed high-fat diet do not have significant differences in responses to various diets to wild type mice
A test of the DSM-5 severity specifier for bulimia nervosa in adolescents: Can we anticipate clinical treatment outcomes?
OBJECTIVE:This study tested clinical utility of the DSM-5 severity specifier for bulimia nervosa (BN) in predicting treatment response among adolescents (Nā=ā110) within a randomized clinical trial of two psychosocial treatments. METHOD:Analyses grouped individuals meeting criteria for BN diagnosis by baseline severity, per DSM-5. Associations among baseline severity classification and BN behavior (i.e., binge eating and compensatory behavior) and eating disorder examination (EDE) Global scores at end-of-treatment (EOT), 6- and 12-month follow-up were examined. RESULTS:Associations between severity categories with BN symptoms were not significant at EOT, or follow-up. Test for linear trend in BN behavior was significant at EOT, Fā=ā5.23, pā=ā0.02, without demonstrating a linear pattern. Relation between severity categories with EDE Global scores was significant at 6-month follow-up, Fā=ā3.76, pā=ā0.01. Tests for linear trend in EDE Global scores were significant at EOT, Fā=ā5.40, pā=ā0.02, and at 6 months, Fā=ā10.73, pā=ā0.002, with the expected linear pattern. DISCUSSION:Findings suggest the DSM-5 BN severity specifier holds questionable utility in anticipating outpatient treatment response in adolescents with BN. The specifier may have improved ability to predict attitudinal rather than behavioral treatment outcomes
Nociceptin Signals Through Calcium in \u3ci\u3eTetrahymena thermophila\u3c/i\u3e
Tetrahymena thermophila are free-living, ciliated, eukaryotic organisms that respond to stimuli by moving toward chemoattractants and avoiding chemorepellents. Chemoattractant responses involve faster ciliary beating, which propels the organisms forward more rapidly. Chemorepellents signaling involves ciliary reversal, which disrupts forward swimming, and causes the organisms to jerk back and forth, swim in small circles, or spin in an attempt to get away from the repellent. Many food sources, such as proteins, are chemoattractants for these organisms, while a variety of compounds are repellents. Repellents in nature are thought to come from the secretions of predators, or from ruptured organisms, which may serve as danger signals. Interestingly, several hormones involved in human pain signaling have been shown to be chemorepellents in Tetrahymena, including substance P, ACTH, PACAP, VIP, and nociceptin.
Recently, we have been studying Tetrahymena response to nociceptin, using pharmacological inhibitors in order to elucidate components of the nociceptin signaling pathway. We have found that G-protein inhibitors and a number of mammalian tyrosine kinase inhibitors have no effect on nociceptin avoidance. However, the tyrosine kinase inhibitor, genistein, inhibits avoidance to nociceptin. Nociceptin avoidance is also inhibited by the calcium chelator, EGTA, which implicates calcium in the avoidance response. Electrophysiology studies done in a calcium-containing buffer show that 50 Ī¼M nociceptin causes a sustained depolarization of approximately 30 mV, further supporting the hypothesis that calcium is involved in nociceptin signaling.
J-113397, an inhibitor of the human nociceptin receptor, also inhibits nociceptin avoidance in Tetrahymena. We are currently working to determine whether other inhibitors of the human nociceptin receptor have any effect on Tetrahymena, in order to get a more complete picture of the signaling pathway
Comparison of Oxidative Properties, Light Absorbance, and Total and Elemental Mass Concentration of Ambient PM(2.5) Collected at 20 European Sites
OBJECTIVE: It has been proposed that the redox activity of particles may represent a major determinant of their toxicity. We measured the in vitro ability of ambient fine particles [particulate matter with aerodynamic diameters ā¤2.5 Ī¼m (PM(2.5))] to form hydroxyl radicals ((ā¢)OH) in an oxidant environment, as well as to deplete physiologic antioxidants (ascorbic acid, glutathione) in the naturally reducing environment of the respiratory tract lining fluid (RTLF). The objective was to examine how these toxicologically relevant measures were related to other PM characteristics, such as total and elemental mass concentration and light absorbance. DESIGN: Gravimetric PM(2.5) samples (n = 716) collected over 1 year from 20 centers participating in the European Community Respiratory Health Survey were available. Light absorbance of these filters was measured with reflectometry. PM suspensions were recovered from filters by vortexing and sonication before dilution to a standard concentration. The oxidative activity of these particle suspensions was then assessed by measuring their ability to generate (ā¢)OH in the presence of hydrogen peroxide, using electron spin resonance and 5,5-dimethyl-1-pyrroline-N-oxide as spin trap, or by establishing their capacity to deplete antioxidants from a synthetic model of the RTLF. RESULTS AND CONCLUSION: PM oxidative activity varied significantly among European sampling sites. Correlations between oxidative activity and all other characteristics of PM were low, both within centers (temporal correlation) and across communities (annual mean). Thus, no single surrogate measure of PM redox activity could be identified. Because these novel measures are suggested to reflect crucial biologic mechanisms of PM, their use may be pertinent in epidemiologic studies. Therefore, it is important to define the appropriate methods to determine oxidative activity of PM
Integrating Machine Learning for Planetary Science: Perspectives for the Next Decade
Machine learning (ML) methods can expand our ability to construct, and draw
insight from large datasets. Despite the increasing volume of planetary
observations, our field has seen few applications of ML in comparison to other
sciences. To support these methods, we propose ten recommendations for
bolstering a data-rich future in planetary science.Comment: 10 pages (expanded citations compared to 8 page submitted version for
decadal survey), 3 figures, white paper submitted to the Planetary Science
and Astrobiology Decadal Survey 2023-203
School bullying from a sociocultural perspective
School bullying is an important concern. Whilst there is growing knowledge about the nature, extent and effects of school bullying, areas of complexity in research findings remain. In this paper we develop our thinking on school bullying using a sociocultural theoretical framework. We review existing literature around three main themes: 1) The conceptualisation and interpretation of bullying; 2) The relational aspects of bullying 3) Bullying as part of someoneās life trajectory. For each theme, empirical findings are discussed to highlight key issues, and arguments presented from relevant sociocultural theories to provide insight in each case. During the paper, we show how varying strands of research into bullying can be integrated, and how areas of complexity can be explained. Adopting a sociocultural view of school bullying presents implications for both research and practice. Bullying is contextual, and attention should be given to the situated relationships and multiple settings surrounding the behaviour
Development of West-European PM2.5 and NO2 land use regression models incorporating satellite-derived and chemical transport modelling data
Satellite-derived (SAT) and chemical transport model (CTM) estimates of PM2.5 and NO2 are increasingly used in combination with Land Use Regression (LUR) models. We aimed to compare the contribution of SAT and CTM data to the performance of LUR PM2.5 and NO2 models for Europe. Four sets of models, all including local traffic and land use variables, were compared (LUR without SAT or CTM, with SAT only, with CTM only, and with both SAT and CTM). LUR models were developed using two monitoring data sets: PM2.5 and NO2 ground level measurements from the European Study of Cohorts for Air Pollution Effects (ESCAPE) and from the European AIRBASE network. LUR PM2.5 models including SAT and SAT+CTM explained ~60% of spatial variation in measured PM2.5 concentrations, substantially more than the LUR model without SAT and CTM (adjR(2): 0.33-0.38). For NO2 CTM improved prediction modestly (adjR(2): 0.58) compared to models without SAT and CTM (adjR(2): 0.47-0.51). Both monitoring networks are capable of producing models explaining the spatial variance over a large study area. SAT and CTM estimates of PM2.5 and NO2 significantly improved the performance of high spatial resolution LUR models at the European scale for use in large epidemiological studies
From research to practice: Lay adherence counsellors' fidelity to an evidence-based intervention for promoting adherence to antiretroviral treatment in the Western Cape, South Africa
In the Western Cape, lay counsellors are tasked
with supporting antiretroviral (ARV) adherence in public
healthcare clinics. Thirty-nine counsellors in 21 Cape
Town clinics were trained in Options for Health (Options),
an evidence-based intervention based on motivational
interviewing (MI). We evaluated counsellorsā ability to
deliver Options for addressing poor adherence following
5 days training. Audio-recordings of counselling sessions
collected following training were transcribed and translated
into English. Thirty-five transcripts of sessions conducted
by 35 counsellors were analysed for fidelity to the Options
protocol, and using the Motivational Interviewing
Treatment and Integrity (MITI) code. Counsellors struggled
with some of the strategies associated with MI, such as
assessing readiness-to-change and facilitating change talk.
Overall, counsellors failed to achieve proficiency in the
approach of MI according to the MITI. Counsellors were
able to negotiate realistic plans for addressing patientsā
barriers to adherence. Further efforts aimed at strengthening
the ARV adherence counselling programme are
needed.Department of HE and Training approved lis
Transcriptional regulation of Elf-1: locus-wide analysis reveals four distinct promoters, a tissue-specific enhancer, control by PU.1 and the importance of Elf-1 downregulation for erythroid maturation
Ets transcription factors play important roles during the development and maintenance of the haematopoietic system. One such factor, Elf-1 (E74-like factor 1) controls the expression of multiple essential haematopoietic regulators including Scl/Tal1, Lmo2 and PU.1. However, to integrate Elf-1 into the wider regulatory hierarchies controlling haematopoietic development and differentiation, regulatory elements as well as upstream regulators of Elf-1 need to be identified. Here, we have used locus-wide comparative genomic analysis coupled with chromatin immunoprecipitation (ChIP-chip) assays which resulted in the identification of five distinct regulatory regions directing expression of Elf-1. Further, ChIP-chip assays followed by functional validation demonstrated that the key haematopoietic transcription factor PU.1 is a major upstream regulator of Elf-1. Finally, overexpression studies in a well-characterized erythroid differentiation assay from primary murine fetal liver cells demonstrated that Elf-1 downregulation is necessary for terminal erythroid differentiation. Given the known activation of PU.1 by Elf-1 and our newly identified reciprocal activation of Elf-1 by PU.1, identification of an inhibitory role for Elf-1 has significant implications for our understanding of how PU.1 controls myeloidāerythroid differentiation. Our findings therefore not only represent the first report of Elf-1 regulation but also enhance our understanding of the wider regulatory networks that control haematopoiesis
Working with Research IntegrityāGuidance for Research Performing Organisations: The Bonn PRINTEGER Statement
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