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Slouha E, Biput SJ, Kuteyi A, Kalloo AE, Gorantla VR. Non-alcoholic Fatty Liver Disease and Gallstones: A Systematic Review. Cureus 2023; 15:e45027. [PMID: 37829934 PMCID: PMC10566311 DOI: 10.7759/cureus.45027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/10/2023] [Indexed: 10/14/2023] Open
Abstract
Non-alcoholic fatty liver disease (NAFLD) is steatosis of the liver that resembles alcohol-induced liver injury but is a metabolic disorder. Most patients are obese with increased triglyceride levels due to increased intake of fatty food, which can cause excess fat to build up in the liver. At the same time, continuous ingestion of fatty foods can lead to gallstones (GS) due to the overproduction of cholesterol. NAFLD and GS have been seen to coincide, and there might be a relationship between them. This systematic review analyzes the incidence of NAFLD and GS to determine a bidirectional relationship. A comprehensive literature review was done using ProQuest, PubMed, and ScienceDirect, and included only experimental studies and meta-analyses. The search included the keywords 'gallstones and non-alcoholic fatty liver disease' and 'cholelithiasis and non-alcoholic fatty liver disease'. Our initial search included 10,665 articles and was narrowed down to 19 through extensive inclusion and exclusion criteria. There is a bidirectional relationship between the incidence of NAFLD and GS, where an increase in either can lead to an increase in the other. Both NAFLD and GS share similar risk factors leading to the development of each disease. On average, there's an increase in the prevalence of gallstones in NAFLD patients, and patients with GS were also more likely to have NAFLD. There was a prevalence of NAFLD in those with asymptomatic gallstones as well, indicating that the risk factors are crucial in the development of both. As a result, some research is determining whether an evaluation of the liver should be routine during cholecystectomy due to the increased risk of developing NAFLD.
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Affiliation(s)
- Ethan Slouha
- Medical School, St. George's University School of Medicine, True Blue, GRD
| | - Stefan J Biput
- Medical School, St. George's University School of Medicine, True Blue, GRD
| | - Azeez Kuteyi
- Medical School, St. George's University School of Medicine, True Blue, GRD
| | - Amy E Kalloo
- Clinical Sciences, St. George's University, True Blue, GRD
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Kenny B, Bowe SJ, Taylor CB, Moodie M, Brown V, Hoban E, Williams J. Longitudinal relationships between sub-clinical depression, sub-clinical eating disorders and health-related quality of life in early adolescence. Int J Eat Disord 2023; 56:1114-1124. [PMID: 36896467 PMCID: PMC10946984 DOI: 10.1002/eat.23928] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Revised: 02/22/2023] [Accepted: 02/22/2023] [Indexed: 03/11/2023]
Abstract
OBJECTIVE A comprehensive understanding of the relationship between depressive symptoms and eating disorder (ED) symptoms requires consideration of additional variables that may influence this relationship. Health-related quality of life (HRQOL) has been associated with both depression and EDs; however, there is limited evidence to demonstrate how all three variables interact over time. This study sought to explore the bi-directional relationships between depressive symptoms, ED symptoms and HRQOL in a large community sample of young adolescents METHOD: Adolescents (N = 1393) aged between 11 and 14 years (M = 12.50, SD = 0.38) completed an online survey measuring depressive symptoms, ED symptoms and HRQOL. Two-level autoregressive cross-lagged models with three variables (i.e., depressive symptoms, HRQOL and ED) assessed across two time points (T1 and T2) were created to address the study aims. RESULTS HRQOL was found to predict depressive symptoms and depressive symptoms were found to predict ED symptoms. Components of HRQOL (i.e., social relationships and ability to cope) were found to share a differential relationship with depressive symptoms. Inability to cope predicted depressive symptoms and depressive symptoms predicted negative social relationships. EDs were found to predict reduced HRQOL and negative social relationships. DISCUSSION Findings suggest prevention and early intervention programs designed to address adolescent depression should focus on improving HRQOL. Future research should assess the relationship between HRQOL and individual ED symptoms (e.g., body-related ED symptoms, restrictive symptoms) as a means of exploring relationships that may have been masked by assessing ED symptoms using a total score. PUBLIC SIGNIFICANCE This study sought to explore how eating disorders, depressive symptoms, and health-related quality of life (HRQOL) relate over time in a sample of young adolescents. Findings indicate adolescents who self-reported lower levels of HRQOL, including a reduced ability to cope, are at risk of experiencing depressive symptoms. Adolescents should be provided with the tools to develop problem-focused coping strategies as a means of reducing depressive symptoms.
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Affiliation(s)
- Bridget Kenny
- School of Health and Social Development, Faculty of HealthDeakin UniversityGeelongVictoriaAustralia
| | - Steven J. Bowe
- Biostatistics Unit, Faculty of HealthDeakin UniversityGeelongVictoriaAustralia
| | - C. Barr Taylor
- School of Medicine, Department of Psychiatry and Behavioral SciencesStanford UniversityStanfordCaliforniaUSA
- Center for m2HealthPalo Alto UniversityPalo AltoCaliforniaUSA
| | - Marj Moodie
- Deakin Health Economics, School of Health and Social Development, Faculty of HealthDeakin UniversityGeelongVictoriaAustralia
| | - Vicki Brown
- Deakin Health Economics, School of Health and Social Development, Faculty of HealthDeakin UniversityGeelongVictoriaAustralia
| | - Elizabeth Hoban
- School of Health and Social Development, Faculty of HealthDeakin UniversityGeelongVictoriaAustralia
| | - Joanne Williams
- School of Health and Social Development, Faculty of HealthDeakin UniversityGeelongVictoriaAustralia
- School of Health SciencesSwinburne University of TechnologyHawthornVictoriaAustralia
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Su WJ, Wang ZS. Development of a Non-Linear Bi-Directional Vortex-Induced Piezoelectric Energy Harvester with Magnetic Interaction. Sensors (Basel) 2021; 21:2299. [PMID: 33806133 DOI: 10.3390/s21072299] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 03/19/2021] [Accepted: 03/22/2021] [Indexed: 11/29/2022]
Abstract
In this study, magnetic force is introduced to the design of a bi-directional U-shaped piezoelectric energy harvester for vortex-induced vibrations. The theoretical model of the beam structure is derived based on the Euler–Bernoulli beam theory. The vortex-induced vibration and the non-linear magnetic force are modeled according to the Rayleigh oscillator and the charge model, respectively. A prototype is fabricated and tested in two orthogonal directions under vortex-induced vibrations in a wind tunnel. Up and down wind-speed sweeps are carried out to investigate the non-linear responses of the harvester. The distance between the magnets and the length of the side beams are adjusted to examine the influence of the magnetic force on the lock-in region and voltage output of the harvester. Overall, the harvester shows strong non-linearity in the horizontal excitations. After adding magnets to the system, significant improvement of the lock-in region and the peak voltage is noticed in the horizontal mode under both up and down sweeps.
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Bobo WV, Ryu E, Petterson TM, Lackore K, Cheng Y, Liu H, Suarez L, Preisig M, Cooper LT, Roger VL, Pathak J, Chamberlain AM. Bi-directional association between depression and HF: An electronic health records-based cohort study. J Comorb 2021; 10:2235042X20984059. [PMID: 33489926 PMCID: PMC7768856 DOI: 10.1177/2235042x20984059] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 11/21/2020] [Accepted: 12/05/2020] [Indexed: 11/16/2022]
Abstract
Objective: To determine whether a bi-directional relationship exists between depression and HF within a single population of individuals receiving primary care services, using longitudinal electronic health records (EHRs). Methods: This retrospective cohort study utilized EHRs for adults who received primary care services within a large healthcare system in 2006. Validated EHR-based algorithms identified 10,649 people with depression (depression cohort) and 5,911 people with HF (HF cohort) between January 1, 2006 and December 31, 2018. Each person with depression or HF was matched 1:1 with an unaffected referent on age, sex, and outpatient service use. Each cohort (with their matched referents) was followed up electronically to identify newly diagnosed HF (in the depression cohort) and depression (in the HF cohort) that occurred after the index diagnosis of depression or HF, respectively. The risks of these outcomes were compared (vs. referents) using marginal Cox proportional hazard models adjusted for 16 comorbid chronic conditions. Results: 2,024 occurrences of newly diagnosed HF were observed in the depression cohort and 944 occurrences of newly diagnosed depression were observed in the HF cohort over approximately 4–6 years of follow-up. People with depression had significantly increased risk for developing newly diagnosed HF (HR 2.08, 95% CI 1.89–2.28) and people with HF had a significantly increased risk of newly diagnosed depression (HR 1.34, 95% CI 1.17–1.54) after adjusting for all 16 comorbid chronic conditions. Conclusion: These results provide evidence of a bi-directional relationship between depression and HF independently of age, sex, and multimorbidity from chronic illnesses.
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Affiliation(s)
- William V Bobo
- Department of Psychiatry and Psychology, Mayo Clinic, Jacksonville, FL, USA
| | - Euijung Ryu
- Department of Health Sciences Research, Mayo Clinic, Rochester, MN, USA
| | - Tanya M Petterson
- Department of Health Sciences Research, Mayo Clinic, Rochester, MN, USA
| | - Kandace Lackore
- Department of Health Sciences Research, Mayo Clinic, Rochester, MN, USA
| | - Yijing Cheng
- Department of Health Sciences Research, Mayo Clinic, Rochester, MN, USA
| | - Hongfang Liu
- Division of Digital Health Science, Mayo Clinic, Rochester, MN, USA
| | - Laura Suarez
- Department of Psychiatry and Psychology, Mayo Clinic, Rochester, MN, USA
| | - Martin Preisig
- Department of Psychiatry, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Leslie T Cooper
- Department of Cardiovascular Medicine, Mayo Clinic, Jacksonville, FL, USA
| | - Veronique L Roger
- Department of Health Sciences Research, Mayo Clinic, Rochester, MN, USA.,Department of Cardiovascular Diseases, Mayo Clinic, Rochester, MN, USA
| | - Jyotishman Pathak
- Department of Psychiatry, Weill Cornell Medicine, New York, NY, USA.,Department of Population Health Sciences, Weill Cornell Medicine, NY, NY, USA
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Saeed M, Isnani AC, Khan SA, Khamis N. Students' Feedback about Feedback; Have our PBL tutors started the shift towards a dialogic ask-tell-ask approach? Pak J Med Sci 2020; 36:1698-1702. [PMID: 33235600 PMCID: PMC7674888 DOI: 10.12669/pjms.36.7.1778] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Objective: A paradigm shift towards a PBL bidirectional dialogic feedback can enhance learners’ performance. This study aimed to investigate undergraduate medical students’ perceptions of their PBL feedback. Methods: We sent e-mail invitations to a web-based survey to year one and two students at College of Medicine, King Saud University. Items included the process, content, and benefits of PBL feedback. Results: Of 209 respondents, 110 (53%) were first and 99 (47%) were second-year students. About 50% agreed that the feedback was regularly provided at scheduled timing and 72% perceived feedback environment as non-threatening. Agreement rates that the tutors asked students first to assess their performance, tell them what went well, what the areas for improvement are and develop with them an improvement plan were 59%, 61%, 61% and 52%, respectively. 61% agreed that tutors judged performance not personality. More year one students significantly agreed that the PBL feedback helped them to improve their knowledge acquisition and non-technical skills. Conclusion: Many of our PBL tutors have started the shift to a dialogic bi-directional feedback. We recommend continuing the faculty development efforts, peer-reviewing, and seeking student’s feedback within the academic quality satisfaction surveys.
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Affiliation(s)
- Majda Saeed
- Majda Saeed, Medical Education Department, College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Arthur C Isnani
- Arthur C. Isnani, Obesity Research Center, College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Samina A Khan
- Samina A. Khan, Medical Education Department, College of Medicine, King Saud University, Riyadh, Saudi Arabia. National Advanced IPv6 Centre (NAv6), Universiti Sains Malaysia, Pulau Penang, Malaysia
| | - Nehal Khamis
- Nehal Khamis, Saudi Commission for Health Specialties, Riyadh, Saudi Arabia. Pathology and Medical Education Departments, College of Medicine, Suez Canal University, Ismailia, Egypt
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Gabl R, Stummer F. Development of a Sensor to Measure Physician Consultation Times. Sensors (Basel) 2019; 19:s19245359. [PMID: 31817359 PMCID: PMC6960857 DOI: 10.3390/s19245359] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Revised: 11/21/2019] [Accepted: 11/30/2019] [Indexed: 11/21/2022]
Abstract
The duration of patient–physician contact is an important factor for the optimisation of treatment processes in healthcare systems. Available methods can be labour-intensive and the quality is, in many cases, poor. A part of this research project is to develop a sensor system, which allows the detection of people passing through a door, including the direction. For this purpose, two time of flight sensors are combined with a door sensor and a motion detection sensor (for redundancy) on one single side of the door frame. The period between two single measurements could be reduced to 50 ms, which allows the measurement of walking speed up to 2 ms−1. The accuracy of the time stamp for each event is less than one second and ensures a precise documentation of the consultation time. This paper presents the development of the sensor system, the miniaturisation of the installation and first measurement results, as well as the measurement’s concept of quality analysis, including multiple door applications. In future steps, the sensor system will be deployed at different medical practices to determine the exact duration of the patient–physician interaction over a longer time period.
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Affiliation(s)
- Roman Gabl
- School of Engineering, Institute for Energy Systems, FloWave Ocean Energy Research Facility, The University of Edinburgh, Max Born Crescent, Edinburgh EH9 3BF, UK
- Correspondence: (R.G.); (F.S.)
| | - Florian Stummer
- Deanery of Molecular, Genetic and Population Health Sciences, Usher Institute, The University of Edinburgh, Old Medical School, Teviot Place, Edinburgh EH8 9AG, UK
- Correspondence: (R.G.); (F.S.)
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Aleyan S, Gohari MR, Cole AG, Leatherdale ST. Exploring the Bi-Directional Association between Tobacco and E-Cigarette Use among Youth in Canada. Int J Environ Res Public Health 2019; 16:E4256. [PMID: 31683972 DOI: 10.3390/ijerph16214256] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Revised: 10/22/2019] [Accepted: 10/30/2019] [Indexed: 12/21/2022]
Abstract
Research has demonstrated associations between e-cigarette use and tobacco use among youth. However, few studies have examined whether reciprocal relationships exist between e-cigarette and tobacco use. The objective of this study was to examine whether bi-directional associations exist between e-cigarette and tobacco use in a large longitudinal sample of Canadian youth. A longitudinal sample of secondary students (n = 6729) attending 87 schools in Ontario and Alberta, Canada, who completed the COMPASS student questionnaire across three waves (from 2014–2015 to 2016–2017) was identified. Using cross-lagged models, we explored bi-directional associations between current tobacco and e-cigarette use, adjusting for relevant covariates. Our findings showed that current e-cigarette use predicted subsequent tobacco use between Wave 1 (W1) and Wave 2 (W2) of the study (W1–2: OR = 1.54, 95% CI = 1.37–1.74). Similarly, current tobacco use predicted e-cigarette use during earlier waves of the study (W1–2: OR = 1.43, 95% CI = 1.30–1.58). However, these relationships dissipated in later waves, when tobacco use no longer predicted e-cigarette use (W2–3: OR = 1.07, 95% CI = 0.99–1.16). This study extends prior work that focused mainly on the association between e-cigarette and subsequent tobacco use. Specifically, our findings portray a more complex relationship, where e-cigarette use may influence and be influenced by tobacco use.
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Middleton BR, Talaugon S, Young TM, Wong L, Fluharty S, Reed K, Cosby C, Myers R. Bi-Directional Learning: Identifying Contaminants on the Yurok Indian Reservation. Int J Environ Res Public Health 2019; 16:ijerph16193513. [PMID: 31547171 PMCID: PMC6801823 DOI: 10.3390/ijerph16193513] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/11/2019] [Revised: 09/01/2019] [Accepted: 09/11/2019] [Indexed: 12/27/2022]
Abstract
The Yurok Tribe partnered with the University of California Davis (UC Davis) Superfund Research Program to identify and address contaminants in the Klamath watershed that may be impairing human and ecosystem health. We draw on a community-based participatory research approach that begins with community concerns, includes shared duties across the research process, and collaborative interpretation of results. A primary challenge facing University and Tribal researchers on this project is the complexity of the relationship(s) between the identity and concentrations of contaminants and the diversity of illnesses plaguing community members. The framework of bi-directional learning includes Yurok-led river sampling, Yurok traditional ecological knowledge, University lab analysis, and collaborative interpretation of results. Yurok staff and community members share their unique exposure pathways, their knowledge of the landscape, their past scientific studies, and the history of landscape management, and University researchers use both specific and broad scope chemical screening techniques to attempt to identify contaminants and their sources. Both university and tribal knowledge are crucial to understanding the relationship between human and environmental health. This paper examines University and Tribal researchers' shared learning, progress, and challenges at the end of the second year of a five-year Superfund Research Program (SRP) grant to identify and remediate toxins in the lower Klamath River watershed. Our water quality research is framed within a larger question of how to best build university-Tribal collaboration to address contamination and associated human health impacts.
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Affiliation(s)
- Beth Rose Middleton
- Department of Native American Studies, University of California, Davis, CA 95616, USA.
| | - Sabine Talaugon
- Department of Native American Studies, University of California, Davis, CA 95616, USA.
| | - Thomas M Young
- Department of Civil and Environmental Engineering, University of California, Davis, CA 95616, USA.
| | - Luann Wong
- Department of Civil and Environmental Engineering, University of California, Davis, CA 95616, USA.
| | | | - Kaitlin Reed
- Native American Studies, Humboldt State University, CA 95521, USA.
| | | | - Richard Myers
- Yurok Tribe Environmental Program, Klamath, CA 95548, USA
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Eichler J, Schmidt R, Poulain T, Hiemisch A, Kiess W, Hilbert A. Stability, Continuity, and Bi-Directional Associations of Parental Feeding Practices and Standardized Child Body Mass Index in Children from 2 to 12 Years of Age. Nutrients 2019; 11:nu11081751. [PMID: 31366059 PMCID: PMC6723946 DOI: 10.3390/nu11081751] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 07/19/2019] [Accepted: 07/23/2019] [Indexed: 02/06/2023] Open
Abstract
(1) Background: Parental feeding practices are related to child body mass index (BMI, kg/m2) and seem to be a consequence rather than cause of child BMI, but research so far is limited. Stability and continuity of feeding practices, probably explaining changes in food intake and child BMI, remain to be poorly examined. (2) Methods: Feeding practices (i.e., restriction, food as reward, pressure to eat, monitoring) assessed via the Child Feeding Questionnaire, child age, standardized BMI (zBMI), and socio-economic status were measured annually at multiple visits (range 2–8) in a population-based longitudinal cohort study of 1512 parents with their children aged 2 to 12 years. Stability, continuity, and bi-directionality of feeding practices and child zBMI were calculated using correlation coefficients, paired t tests, and cross-lagged panels, respectively. (3) Results: Feeding practices and child zBMI showed moderate to high stability. While continuity was high for restriction, minor temporal changes were observed for other feeding practices and child zBMI. Cross-lags indicated that child zBMI predicted restriction, pressure to eat, and monitoring, while food-rewarding predicted child zBMI only minorly. (4) Conclusions: Parents seem to adapt feeding practices to child zBMI with the exception of food-rewarding.
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Affiliation(s)
- Janina Eichler
- Leipzig University Medical Center, Integrated Research and Treatment Center AdiposityDiseases, Medical Psychology and Medical Sociology, Psychosomatic Medicine and Psychotherapy, Philipp-Rosenthal-Strasse 27, 04103 Leipzig, Germany.
| | - Ricarda Schmidt
- Leipzig University Medical Center, Integrated Research and Treatment Center AdiposityDiseases, Medical Psychology and Medical Sociology, Psychosomatic Medicine and Psychotherapy, Philipp-Rosenthal-Strasse 27, 04103 Leipzig, Germany
| | - Tanja Poulain
- LIFE Child Leipzig Research Center for Civilization Diseases, Leipzig University, Philipp-Rosenthal-Strasse 27, 04103 Leipzig, Germany
- Department of Women and Child Health, Hospital for Children and Adolescents and Centre for Paediatric Research (CPL), Leipzig University, Liebigstrasse 20a, 04103 Leipzig, Germany
| | - Andreas Hiemisch
- LIFE Child Leipzig Research Center for Civilization Diseases, Leipzig University, Philipp-Rosenthal-Strasse 27, 04103 Leipzig, Germany
- Department of Women and Child Health, Hospital for Children and Adolescents and Centre for Paediatric Research (CPL), Leipzig University, Liebigstrasse 20a, 04103 Leipzig, Germany
| | - Wieland Kiess
- LIFE Child Leipzig Research Center for Civilization Diseases, Leipzig University, Philipp-Rosenthal-Strasse 27, 04103 Leipzig, Germany
- Department of Women and Child Health, Hospital for Children and Adolescents and Centre for Paediatric Research (CPL), Leipzig University, Liebigstrasse 20a, 04103 Leipzig, Germany
| | - Anja Hilbert
- Leipzig University Medical Center, Integrated Research and Treatment Center AdiposityDiseases, Medical Psychology and Medical Sociology, Psychosomatic Medicine and Psychotherapy, Philipp-Rosenthal-Strasse 27, 04103 Leipzig, Germany
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Qiu Y, Levendosky RF, Chakravarthy S, Patel A, Bowman GD, Myong S. The Chd1 Chromatin Remodeler Shifts Nucleosomal DNA Bidirectionally as a Monomer. Mol Cell 2017; 68:76-88.e6. [PMID: 28943314 PMCID: PMC5745159 DOI: 10.1016/j.molcel.2017.08.018] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Revised: 06/30/2017] [Accepted: 08/18/2017] [Indexed: 11/18/2022]
Abstract
Chromatin remodelers catalyze dynamic packaging of the genome by carrying out nucleosome assembly/disassembly, histone exchange, and nucleosome repositioning. Remodeling results in evenly spaced nucleosomes, which requires probing both sides of the nucleosome, yet the way remodelers organize sliding activity to achieve this task is not understood. Here, we show that the monomeric Chd1 remodeler shifts DNA back and forth by dynamically alternating between different segments of the nucleosome. During sliding, Chd1 generates unstable remodeling intermediates that spontaneously relax to a pre-remodeled position. We demonstrate that nucleosome sliding is tightly controlled by two regulatory domains: the DNA-binding domain, which interferes with sliding when its range is limited by a truncated linking segment, and the chromodomains, which play a key role in substrate discrimination. We propose that active interplay of the ATPase motor with the regulatory domains may promote dynamic nucleosome structures uniquely suited for histone exchange and chromatin reorganization during transcription.
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Affiliation(s)
- Yupeng Qiu
- Department of Biophysics, Johns Hopkins University, Baltimore, MD 21218, USA; Department of Bioengineering, University of Illinois, Urbana, IL 61801, USA
| | - Robert F Levendosky
- Department of Biophysics, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Srinivas Chakravarthy
- Biophysics Collaborative Access Team, Argonne National Laboratory, Argonne, IL 60439, USA
| | - Ashok Patel
- Kusuma School of Biological Sciences, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India
| | - Gregory D Bowman
- Department of Biophysics, Johns Hopkins University, Baltimore, MD 21218, USA.
| | - Sua Myong
- Department of Biophysics, Johns Hopkins University, Baltimore, MD 21218, USA; Department of Bioengineering, University of Illinois, Urbana, IL 61801, USA; Physics Frontier Center (Center for Physics of Living Cells), University of Illinois, Urbana, IL 61801, USA.
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Chinneck A, Mackinnon SP, Stewart SH. Investigating Possible Reciprocal Relations Between Depressive and Problem Gambling Symptoms in Emerging Adults. Can J Psychiatry 2016; 61:93-101. [PMID: 27253700 PMCID: PMC4784238 DOI: 10.1177/0706743715625934] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE Previous cross-sectional research has shown that depression and problem gambling co-occur. Longitudinal research, however, allows for a better determination of directionality, as behavioural changes in gambling involvement can be more reliably studied over time. Our study assesses symptoms of depression and problem gambling across 4 waves and addresses whether their relation is directional (with one reliably preceding the other), bidirectional, or pathoplastic. METHOD As part of the Manitoba Longitudinal Study of Young Adults, prospective data were collected on Canadian young adults' (Wave 1: n = 679, 51.8% female, aged 18 to 20 years) depressive symptoms, involvement in gambling, and risky gambling behaviour. Recruitment and the first cycle of data collection (Wave 1) took place in fall 2007. Three additional waves of data collection then occurred in 12- to 18-month intervals: fall 2008, spring 2010, and spring 2011. The Problem Gambling Severity Index and the Composite International Diagnostic Interview-Short Form were administered through telephone interview at each wave. RESULTS Bivariate growth curves showed that depressive and problem gambling symptoms were positively correlated at Wave 1, Wave 2, and Wave 4. Neither disorder was found to be a risk factor for the other, and depression and problem gambling were not pathoplastically related (that is, increases in one did not result in increases in the other over time, and vice versa). CONCLUSIONS While depression and problem gambling are related, their co-occurrence may be better explained not by depressive- or gambling-related risk, but by the presence of a common underlying factor (such as substance abuse).
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Affiliation(s)
- Annie Chinneck
- Department of Psychology and Neuroscience, Dalhousie University, Halifax, Nova Scotia
| | - Sean P Mackinnon
- Department of Psychology and Neuroscience, Dalhousie University, Halifax, Nova Scotia
| | - Sherry H Stewart
- Department of Psychology and Neuroscience, Dalhousie University, Halifax, Nova Scotia
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Tessadori J, Bisio M, Martinoia S, Chiappalone M. Modular neuronal assemblies embodied in a closed-loop environment: toward future integration of brains and machines. Front Neural Circuits 2012; 6:99. [PMID: 23248586 PMCID: PMC3520178 DOI: 10.3389/fncir.2012.00099] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2012] [Accepted: 11/18/2012] [Indexed: 11/13/2022] Open
Abstract
Behaviors, from simple to most complex, require a two-way interaction with the environment and the contribution of different brain areas depending on the orchestrated activation of neuronal assemblies. In this work we present a new hybrid neuro-robotic architecture based on a neural controller bi-directionally connected to a virtual robot implementing a Braitenberg vehicle aimed at avoiding obstacles. The robot is characterized by proximity sensors and wheels, allowing it to navigate into a circular arena with obstacles of different sizes. As neural controller, we used hippocampal cultures dissociated from embryonic rats and kept alive over Micro Electrode Arrays (MEAs) for 3-8 weeks. The developed software architecture guarantees a bi-directional exchange of information between the natural and the artificial part by means of simple linear coding/decoding schemes. We used two different kinds of experimental preparation: "random" and "modular" populations. In the second case, the confinement was assured by a polydimethylsiloxane (PDMS) mask placed over the surface of the MEA device, thus defining two populations interconnected via specific microchannels. The main results of our study are: (i) neuronal cultures can be successfully interfaced to an artificial agent; (ii) modular networks show a different dynamics with respect to random culture, both in terms of spontaneous and evoked electrophysiological patterns; (iii) the robot performs better if a reinforcement learning paradigm (i.e., a tetanic stimulation delivered to the network following each collision) is activated, regardless of the modularity of the culture; (iv) the robot controlled by the modular network further enhances its capabilities in avoiding obstacles during the short-term plasticity trial. The developed paradigm offers a new framework for studying, in simplified model systems, neuro-artificial bi-directional interfaces for the development of new strategies for brain-machine interaction.
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Affiliation(s)
- Jacopo Tessadori
- Department of Neuroscience and Brain Technologies, Istituto Italiano di Tecnologia Genova, Italy
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