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Abstract
PURPOSE To test the non-inferiority of a novel game platform for the treatment of pediatric amblyopia compared to standard eye patching. METHODS Forty participants (ages 4 to 18 years) across seven optometric clinics in the United States diagnosed as having amblyopia associated with anisometropia were randomly assigned to either 12 weeks of eye patching therapy (n = 19) or Barron Vision (Barron Associates, Inc) video game treatment (n = 21). Participants in the eye patching group with best corrected visual acuity (BCVA) worse than 20/200 in their amblyopic eye were prescribed 6 hours of patching daily, whereas those whose BCVA was 20/200 (1.00 logarithm of the minimum angle of resolution [logMAR]) or better were instructed to patch for 2 hours daily. Participants in the video game group, irrespective of the severity of their amblyopia, were instructed to play four different 5-minute mini-games five times a week for a total of 20 minutes a day. RESULTS A mixed linear modeling analysis of before and after BCVA differences after 12 weeks showed the non-inferiority of video game treatment to eye patching using a 0.10 logMAR threshold while adjusting for the participant's age, sex, and baseline BCVA. CONCLUSIONS The results of the study suggest that a 12-week home-based video game vision therapy intervention can provide equivalent treatment outcomes to eye patching for amblyopia in children ages 5 to 18 years. Video game-based vision therapy may be a more acceptable and time-efficient alternative to existing approaches. By incorporating elements of perceptual learning, approaches such as Barron Vision video game treatment may have additional long-term therapeutic benefits and may improve treatment compliance. [J Pediatr Ophthalmol Strabismus. 2024;61(1):20-29.].
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Adams RJ, Ellington AL, Kuccera KA, Leaman H, Smithson C, Patrie JT. Telehealth-Guided Virtual Reality for Recovery of Upper Extremity Function Following Stroke. OTJR (Thorofare N J) 2023; 43:446-456. [PMID: 36960762 PMCID: PMC10499117 DOI: 10.1177/15394492231158375] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/25/2023]
Abstract
This rater-blinded, randomized control trial (RCT) investigated the effectiveness of a Glove Rehabilitation Application for Stroke Patients (GRASP) virtual reality home exercise program (HEP) for upper extremity (UE) motor recovery following stroke. The GRASP system facilitates the use of the affected UE in simulated instrumental activities of daily living (IADLs). Participants were asked to use the system at home in asynchronous telehealth sessions 4 times per week over 8 weeks. A non-blinded occupational therapist (OT) provided synchronous telehealth visits biweekly. Analysis comparing pre- and post-assessment results for the Fugl-Meyer UE assessment (FMUE) shows a clinically important and statistically significant between-group difference for participants completing the GRASP HEP protocol compared with usual and customary care controls. Statistically significant and clinically important differences were also found in Motor Activity Log (MAL) scores. This evidence provides support for the effectiveness of home-based, IADL-focused, virtual reality therapy with telehealth support.
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Affiliation(s)
| | | | - Kate A Kuccera
- University of Virginia Health System, Charlottesville, USA
| | - Hannah Leaman
- University of Virginia Health System, Charlottesville, USA
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Adams RJ, Lunsford CD, Stevenson RD, Ellington AL, Lichter MD, Patrie JT. Concurrent Validity of Measures of Upper Extremity Function Derived from Videogame-Based Motion Capture for Children with Hemiplegia. Games Health J 2023. [PMID: 36944143 DOI: 10.1089/g4h.2022.0160] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/23/2023] Open
Abstract
Objective: Pediatric hemiplegia is associated with wide-ranging deficits in arm and hand motor function, neg-atively impacting participation in daily occupations and quality of life. This study investigated whether performance measures generated during therapy videogame play by children with hemiplegia can be valid indicators of upper extremity motor function. Materials and Methods: Ten children with hemiplegia used a custom therapy game system alternatively using their affected and non-affected hand to provide motion capture data that spans a wide range of motor function status. The children also completed a series of standardized outcome measure assessments with each hand, including the Quality of Upper Extremity Skills Test, the Jebsen Taylor Hand Function Test, and the Wolf Motor Function Test. Results: Statistical analysis using the nonparametric Spearman rank correlation revealed high and significant correlation between videogame-derived motion capture measures, characterizing the speed and smoothness of movements, and the standardized outcome measure assessments. Conclusion: The results suggest that a low-cost motion capture system can be used to monitor a child's motor function status and progress during a therapy program.
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Affiliation(s)
| | | | - Richard D Stevenson
- Department of Pediatrics, University of Virginia, Charlottesville, Virginia, USA
| | - Allison L Ellington
- Department of Occupational Therapy, Mary Baldwin University, Staunton, Virginia, USA
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Parker JL, Adams RJ, Appleton SL, Melaku YA, Vakulin A. 0722 The Association Between Obstructive Sleep Apnea and Neurobehavioural Function in Men: A Large, Population-Based Cohort Study. Sleep 2020. [DOI: 10.1093/sleep/zsaa056.718] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
Introduction
Obstructive sleep apnea (OSA) is linked with impaired vigilance, attention, memory and executive function. However, this evidence largely comes from small experimental studies or larger studies in clinical samples and therefore the scope and magnitude of OSA driven neurobehavioural dysfunction in the general population remains unclear. This study aimed to examine the cross-sectional association between OSA and neurobehavioural function in a large community sample of men.
Methods
A total of 837 participants from the Men Androgen Inflammation Lifestyle Environment and Stress (MAILES) study, a longitudinal cohort of men 40+ years, underwent full overnight polysomnography. Participants completed the inspection time (IT) test, mini-mental state examination (MMSE), Fuld object memory evaluation (FOME), and trail-making test (TMT) part A (TMT-A) and part B (TMT-B). Using regression models adjusted for multiple important covariates, we examined the association between neurobehavioural function scores, clinical metrics of OSA severity (Apnea-Hypopnea Index (AHI); percentage total sleep time with oxygen saturation <90% (TST90), and measures of sleep disruption (duration of rapid eye movement (REM) and non-REM (NREM) sleep; and total sleep time (TST).
Results
In multivariable linear regressions, greater TST was associated with worse IT scores (B=13.688, 95% CI [0.134, 27.241], P=0.048) and TMT-B scores (B=19.255, 95% CI [0.931, 37.578], P=0.040). In logistic regressions, greater TST was associated with better MMSE scores (Odds ratio [OR]=0.440, 95% CI [0.194, 0.997], P=0.049); and higher AHI was strongly associated with worse FOME scores in fully adjusted models (OR=1.358, 95% CI [1.252, 1.472], P<0.001).
Conclusion
The AHI and TST were positively, significantly associated with neurobehavioural function across different domains. This cross-sectional data shows that neurobehavioural function deficits in OSA are directly related to sleep and breathing disruptions. Future large prospective studies are needed to determine if OSA and sleep disruption predict future onset of neurobehavioural dysfunction and cognitive decline.
Support
National Health and Medical Research Council and the Adelaide Institute for Sleep Health.
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Affiliation(s)
- J L Parker
- Adelaide Institute for Sleep Health, College of Medicine and Public Health, Flinders University, Australia, Adelaide, AUSTRALIA
| | - R J Adams
- Adelaide Institute for Sleep Health, College of Medicine and Public Health, Flinders University, Australia, Adelaide, AUSTRALIA
- Respiratory and Sleep Service, Southern Adelaide Local Health Network, Bedford Park, South Australia, Australia., Adelaide, AUSTRALIA
- School of Medicine, the University of Adelaide, Adelaide, South Australia, Adelaide, AUSTRALIA
| | - S L Appleton
- Adelaide Institute for Sleep Health, College of Medicine and Public Health, Flinders University, Australia, Adelaide, AUSTRALIA
- Respiratory and Sleep Service, Southern Adelaide Local Health Network, Bedford Park, South Australia, Australia., Adelaide, AUSTRALIA
- School of Medicine, the University of Adelaide, Adelaide, South Australia, Adelaide, AUSTRALIA
| | - Y A Melaku
- Adelaide Institute for Sleep Health, College of Medicine and Public Health, Flinders University, Australia, Adelaide, AUSTRALIA
| | - A Vakulin
- Adelaide Institute for Sleep Health, College of Medicine and Public Health, Flinders University, Australia, Adelaide, AUSTRALIA
- Sleep and Circadian Research Group, Woolcock Institute of Medical Research, University of Sydney, New South Wales, Australia, Sydney, AUSTRALIA
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Adams RJ, Ellington AL, Armstead K, Sheffield K, Patrie JT, Diamond PT. Upper Extremity Function Assessment Using a Glove Orthosis and Virtual Reality System. OTJR (Thorofare N J) 2019; 39:81-89. [PMID: 30885076 PMCID: PMC6429623 DOI: 10.1177/1539449219829862] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [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] [Indexed: 11/16/2022]
Abstract
Hand motor control deficits following stroke can diminish the ability of patients to participate in daily activities. This study investigated the criterion validity of upper extremity (UE) performance measures automatically derived from sensor data during manual practice of simulated instrumental activities of daily living (IADLs) within a virtual environment. A commercial glove orthosis was specially instrumented with motion tracking sensors to enable patients to interact, through functional UE movements, with a computer-generated virtual world using the SaeboVR software system. Fifteen stroke patients completed four virtual IADL practice sessions, as well as a battery of gold-standard assessments of UE motor and hand function. Statistical analysis using the nonparametric Spearman rank correlation reveals high and significant correlation between virtual world-derived measures and the gold-standard assessments. The results provide evidence that performance measures generated during manual interactions with a virtual environment can provide a valid indicator of UE motor status.
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Clark DG, Boan AD, Sims-Robinson C, Adams RJ, Amella EJ, Benitez A, Lackland DT, Ovbiagele B. Differential Impact of Index Stroke on Dementia Risk in African-Americans Compared to Whites. J Stroke Cerebrovasc Dis 2018; 27:2725-2730. [PMID: 30076114 DOI: 10.1016/j.jstrokecerebrovasdis.2018.05.048] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [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: 03/15/2018] [Revised: 05/17/2018] [Accepted: 05/28/2018] [Indexed: 12/14/2022] Open
Abstract
OBJECTIVE To compare whites and African-Americans in terms of dementia risk following index stroke. METHODS The data consisted of billing and International Classification of Diseases, Ninth Revision diagnosis codes from the South Carolina Revenue and Fiscal Affairs office on all hospital discharges within the state between 2000 and 2012. The sample consisted of 68,758 individuals with a diagnosis of ischemic stroke prior to 2010 (49,262 white [71.65%] and 19,496 African-Americans [28.35%]). We identified individuals in the dataset who were subsequently diagnosed with any of 5 categories of dementia and evaluated time to dementia diagnosis in Cox Proportional Hazards models. We plotted cumulative hazard curves to illustrate the effect of race on dementia risk after controlling for age, sex, and occurrence of intervening stroke. RESULTS Age at index stroke was significantly different between the 2 groups, with African-Americans being younger on average (70.0 [SD 12.5] in whites versus 64.5 [SD 14.1] in African-Americans, P < .0001). Adjusted hazard ratios revealed that African-American race increased risk for all 5 categories of dementia following incident stroke, ranging from 1.37 for AD to 1.95 for vascular dementia. Age, female sex, and intervening stroke likewise increased risk for dementia. CONCLUSIONS African-Americans are at higher risk for dementia than whites within 5 years of ischemic stroke, regardless of dementia subtype. Incident strokes may have a greater likelihood of precipitating dementia in African-Americans due to higher prevalence of nonstroke cerebrovascular disease or other metabolic or vascular factors that contribute to cognitive impairment.
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Affiliation(s)
- D G Clark
- Department of Neurology, Medical University of South Carolina, Charleston, South Carolina; Department of Neurology, Ralph H. Johnson VA Medical Center, Charleston, South Carolina.
| | - A D Boan
- Department of Neurology, Medical University of South Carolina, Charleston, South Carolina; Department of Pediatrics, Medical University of South Carolina, Charleston, South Carolina
| | - C Sims-Robinson
- Department of Neurology, Medical University of South Carolina, Charleston, South Carolina
| | - R J Adams
- Department of Neurology, Medical University of South Carolina, Charleston, South Carolina
| | - E J Amella
- College of Nursing, Medical University of South Carolina, Charleston, South Carolina
| | - A Benitez
- Department of Neurology, Medical University of South Carolina, Charleston, South Carolina
| | - D T Lackland
- Department of Neurology, Medical University of South Carolina, Charleston, South Carolina
| | - B Ovbiagele
- Department of Neurology, Medical University of South Carolina, Charleston, South Carolina
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Wright DJ, Adams RJ, Blacklock J, Corlett SA, Harmston R, McWilliams M, Whyte SA, Fleming G. Longitudinal qualitative evaluation of pharmacist integration into the urgent care setting. Integr Pharm Res Pract 2018; 7:93-104. [PMID: 30101123 PMCID: PMC6067628 DOI: 10.2147/iprp.s168471] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [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: 12/04/2022] Open
Abstract
Purpose To describe the most effective model for managing, educating, and training pharmacist advanced clinical practitioners (ACPs) in the urgent care center (UCC) setting, role evolution and how to measure their effectiveness. Participants and methods Ethical approval was obtained to perform a qualitative longitudinal cohort study in three sites, with three pharmacists in each trained as ACPs from 2016 to 2017. ACP role, location, management, mentorship, and supervision were locally determined. ACPs attended focus groups (FGs) at 1 and 3 months (sites 1–3), 6 and 12 months (site 1 only), and the UCC staff were interviewed once with a topic guide regarding training, integration, role, and impact. Verbatim transcriptions were analyzed thematically. Results Eight ACP FGs and 24 stakeholder interviews produced major themes of communication, management, education and training, role, and outcomes. Effective education, training, and integration required communication of role to address concerns regarding salary differentials, supportive management structure, and multi-professional learning. ACPs reported that the model of workplace training, experiential learning, and university-based education was appropriate. Training was better located in the minor injuries and general practitioner areas. Recommended measures of effectiveness included patient satisfaction and workload transfer. Conclusion The education and training model was appropriate. Communication and management require careful consideration to ensure effective integration and role development. Pharmacists were better located initially in the minor illness rather than major trauma areas. Quality of patient experience resulting from the new role was important in addition to reassurance that the role represented a positive contribution to workload.
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Affiliation(s)
- David J Wright
- School of Pharmacy, University of East Anglia, Norwich, UK,
| | | | | | - Sarah A Corlett
- Medway School of Pharmacy, Universities of Greenwich and Kent at Medway, Chatham, UK
| | - Rebecca Harmston
- Patient and public involvement member of the research team, University of East Anglia, Norwich, UK
| | - Margaret McWilliams
- Patient and public involvement member of the research team, University of East Anglia, Norwich, UK
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Appleton S, Eckert D, Vakulin A, Catcheside P, McEvoy D, Martin S, Wittert G, Adams RJ. 0451 Association Of The Arousal Threshold With Inflammation And Sleepiness In Men With Obstructive Sleep Apnea. Sleep 2018. [DOI: 10.1093/sleep/zsy061.450] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- S Appleton
- The University of Adelaide, Woodville, AUSTRALIA
| | - D Eckert
- University of New South Wales, Sydney, AUSTRALIA
| | - A Vakulin
- Flinders University, Bedford Park, AUSTRALIA
| | | | - D McEvoy
- Flinders University, Bedford Park, AUSTRALIA
| | - S Martin
- The University of Adelaide, Adelaide, AUSTRALIA
| | - G Wittert
- The University of Adelaide, Adelaide, AUSTRALIA
| | - R J Adams
- The University of Adelaide, Woodville, AUSTRALIA
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Adams RJ, Kim SS, Mollenkopf DF, Mathys DA, Schuenemann GM, Daniels JB, Wittum TE. Antimicrobial-resistant Enterobacteriaceae recovered from companion animal and livestock environments. Zoonoses Public Health 2018; 65:519-527. [PMID: 29575700 DOI: 10.1111/zph.12462] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Indexed: 11/30/2022]
Abstract
Antimicrobial-resistant bacteria represent an important concern impacting both veterinary medicine and public health. The rising prevalence of extended-spectrum beta-lactamase (ESBL), AmpC beta-lactamase, carbapenemase (CRE) and fluoroquinolone-resistant Enterobacteriaceae continually decreases the efficiency of clinically important antibiotics. Moreover, the potential for zoonotic transmission of antibiotic-resistant enteric bacteria increases the risk to public health. Our objective was to estimate the prevalence of specific antibiotic-resistant bacteria on human contact surfaces in various animal environments. Environmental surface samples were collected from companion animal shelters, private equine facilities, dairy farms, livestock auction markets and livestock areas of county fairs using electrostatic cloths. Samples were screened for Enterobacteriaceae expressing AmpC, ESBL, CRE or fluoroquinolone resistance using selective media. Livestock auction markets and county fairs had higher levels of bacteria expressing both cephalosporin and fluoroquinolone resistance than did equine, dairy, and companion animal environments. Equine facilities harboured more bacteria expressing cephalosporin resistance than companion animal shelters, but less fluoroquinolone resistance. The regular use of extended-spectrum cephalosporins in livestock populations could account for the increased levels of cephalosporin resistance in livestock environments compared to companion animal and equine facilities. Human surfaces, as well as shared human and animal surfaces, were contaminated with resistant bacteria regardless of species environment. Detecting these bacteria on common human contact surfaces suggests that the environment can serve as a reservoir for the zoonotic transmission of antibiotic-resistant bacteria and resistance genes. Identifying interventions to lower the prevalence of antibiotic-resistant bacteria in animal environments will protect both animal and public health.
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Affiliation(s)
- R J Adams
- Department of Veterinary Preventive Medicine, College of Veterinary Medicine, The Ohio State University, Columbus, OH, USA
| | - S S Kim
- Department of Veterinary Preventive Medicine, College of Veterinary Medicine, The Ohio State University, Columbus, OH, USA
| | - D F Mollenkopf
- Department of Veterinary Preventive Medicine, College of Veterinary Medicine, The Ohio State University, Columbus, OH, USA
| | - D A Mathys
- Department of Veterinary Preventive Medicine, College of Veterinary Medicine, The Ohio State University, Columbus, OH, USA
| | - G M Schuenemann
- Department of Veterinary Preventive Medicine, College of Veterinary Medicine, The Ohio State University, Columbus, OH, USA
| | - J B Daniels
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, The Ohio State University, Columbus, OH, USA
| | - T E Wittum
- Department of Veterinary Preventive Medicine, College of Veterinary Medicine, The Ohio State University, Columbus, OH, USA
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Adams RJ, Lichter MD, Ellington A, White M, Armstead K, Patrie JT, Diamond PT. Virtual Activities of Daily Living for Recovery of Upper Extremity Motor Function. IEEE Trans Neural Syst Rehabil Eng 2018; 26:252-260. [DOI: 10.1109/tnsre.2017.2771272] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Tetley RJ, Blanchard GB, Fletcher AG, Adams RJ, Sanson B. Unipolar distributions of junctional Myosin II identify cell stripe boundaries that drive cell intercalation throughout Drosophila axis extension. eLife 2016; 5:e12094. [PMID: 27183005 PMCID: PMC4915814 DOI: 10.7554/elife.12094] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Accepted: 05/10/2016] [Indexed: 12/21/2022] Open
Abstract
Convergence and extension movements elongate tissues during development. Drosophila germ-band extension (GBE) is one example, which requires active cell rearrangements driven by Myosin II planar polarisation. Here, we develop novel computational methods to analyse the spatiotemporal dynamics of Myosin II during GBE, at the scale of the tissue. We show that initial Myosin II bipolar cell polarization gives way to unipolar enrichment at parasegmental boundaries and two further boundaries within each parasegment, concomitant with a doubling of cell number as the tissue elongates. These boundaries are the primary sites of cell intercalation, behaving as mechanical barriers and providing a mechanism for how cells remain ordered during GBE. Enrichment at parasegment boundaries during GBE is independent of Wingless signaling, suggesting pair-rule gene control. Our results are consistent with recent work showing that a combinatorial code of Toll-like receptors downstream of pair-rule genes contributes to Myosin II polarization via local cell-cell interactions. We propose an updated cell-cell interaction model for Myosin II polarization that we tested in a vertex-based simulation.
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Affiliation(s)
- Robert J Tetley
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom
| | - Guy B Blanchard
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom
| | - Alexander G Fletcher
- School of Mathematics and Statistics, University of Sheffield, Sheffield, United Kingdom
- Bateson Centre, University of Sheffield, Sheffield, United Kingdom
| | - Richard J Adams
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom
| | - Bénédicte Sanson
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom
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Pawluk DTV, Adams RJ, Kitada R. Designing Haptic Assistive Technology for Individuals Who Are Blind or Visually Impaired. IEEE Trans Haptics 2015; 8:258-278. [PMID: 26336151 DOI: 10.1109/toh.2015.2471300] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
This paper considers issues relevant for the design and use of haptic technology for assistive devices for individuals who are blind or visually impaired in some of the major areas of importance: Braille reading, tactile graphics, orientation and mobility. We show that there is a wealth of behavioral research that is highly applicable to assistive technology design. In a few cases, conclusions from behavioral experiments have been directly applied to design with positive results. Differences in brain organization and performance capabilities between individuals who are "early blind" and "late blind" from using the same tactile/haptic accommodations, such as the use of Braille, suggest the importance of training and assessing these groups individually. Practical restrictions on device design, such as performance limitations of the technology and cost, raise questions as to which aspects of these restrictions are truly important to overcome to achieve high performance. In general, this raises the question of what it means to provide functional equivalence as opposed to sensory equivalence.
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Freeman ZT, Rice KA, Soto PL, Pate KAM, Weed MR, Ator NA, DeLeon IG, Wong DF, Zhou Y, Mankowski JL, Zink MC, Adams RJ, Hutchinson EK. Neurocognitive dysfunction and pharmacological intervention using guanfacine in a rhesus macaque model of self-injurious behavior. Transl Psychiatry 2015; 5:e567. [PMID: 25989141 PMCID: PMC4471292 DOI: 10.1038/tp.2015.61] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2014] [Revised: 03/11/2015] [Accepted: 03/24/2015] [Indexed: 11/18/2022] Open
Abstract
Self-injurious behavior (SIB) is a common comorbidity of psychiatric disorders but there is a dearth of information about neurological mechanisms underlying the behavior, and few animal models exist. SIB in humans is characterized by any intentional self-directed behavior that leads to wounds, whereas in macaques it is not always accompanied by wounds. We describe a cohort of rhesus macaques displaying SIB as adults, in which changes within the central nervous system were associated with the SIB. In these macaques, increases in central nervous system striatal dopamine (DA) receptor binding (BPND) measured by positron emission tomography (PET) [11C]raclopride imaging correlated with severity of wounding (rs=0.662, P=0.014). Furthermore, utilizing standardized cognitive function tests, we showed that impulsivity (stop signal reaction time, SSRT) and deficits in attentional set shifting (intra-/extradimensional shift) were correlated with increased severity of SIB (rs=0.563, P=0.045 and rs=0.692, P=0.009, respectively). We also tested the efficacy of guanfacine, an α2A adrenergic agonist that acts to improve postsynaptic transmission of neuronal impulses, in reducing SIB. A subset of these animals were enrolled in a randomized experimenter-blinded study that demonstrated guanfacine decreased the severity of wounding in treated animals compared with vehicle-only-treated controls (P=0.043), with residual beneficial effects seen for several weeks after cessation of therapy. Animals with the highest severity of SIB that received guanfacine also showed the most significant improvement (rs=-0.761, P=0.009). The elevated PET BPND was likely due to low intrasynaptic DA, which in turn may have been improved by guanfacine. With underlying physiology potentially representative of the human condition and the ability to affect outcome measures of disease using pharmacotherapy, this model represents a unique opportunity to further our understanding of the biology and treatment of SIB in both animals and humans.
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Affiliation(s)
- Z T Freeman
- Department of Molecular and Comparative Pathobiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - K A Rice
- Department of Molecular and Comparative Pathobiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA,Division of Veterinary Resources, National Institutes of Health, Bethesda, MD, USA
| | - P L Soto
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - K A M Pate
- Department of Molecular and Comparative Pathobiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - M R Weed
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - N A Ator
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - I G DeLeon
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA,Department of Behavioral Psychology, Kennedy Krieger Institute, Baltimore, MD, USA
| | - D F Wong
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA,Department of Radiology and Radiological Science, Johns Hopkins School of Medicine, Baltimore, MD, USA,Department of Neuroscience, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - Y Zhou
- Department of Radiology and Radiological Science, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - J L Mankowski
- Department of Molecular and Comparative Pathobiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - M C Zink
- Department of Molecular and Comparative Pathobiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - R J Adams
- Department of Molecular and Comparative Pathobiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - E K Hutchinson
- Division of Veterinary Resources, National Institutes of Health, Bethesda, MD, USA,Division of Veterinary Resources, National Institutes of Health, 9000 Rockville Pike, Building 14A, Bethesda, MD 21205, USA. E-mail:
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Adams RJ, Lichter MD, Krepkovich ET, Ellington A, White M, Diamond PT. Assessing upper extremity motor function in practice of virtual activities of daily living. IEEE Trans Neural Syst Rehabil Eng 2014; 23:287-96. [PMID: 25265612 DOI: 10.1109/tnsre.2014.2360149] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
A study was conducted to investigate the criterion validity of measures of upper extremity (UE) motor function derived during practice of virtual activities of daily living (ADLs). Fourteen hemiparetic stroke patients employed a Virtual Occupational Therapy Assistant (VOTA), consisting of a high-fidelity virtual world and a Kinect™ sensor, in four sessions of approximately one hour in duration. An unscented Kalman Filter-based human motion tracking algorithm estimated UE joint kinematics in real-time during performance of virtual ADL activities, enabling both animation of the user's avatar and automated generation of metrics related to speed and smoothness of motion. These metrics, aggregated over discrete sub-task elements during performance of virtual ADLs, were compared to scores from an established assessment of UE motor performance, the Wolf Motor Function Test (WMFT). Spearman's rank correlation analysis indicates a moderate correlation between VOTA-derived metrics and the time-based WMFT assessments, supporting the criterion validity of VOTA measures as a means of tracking patient progress during an UE rehabilitation program that includes practice of virtual ADLs.
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Booth AJR, Blanchard GB, Adams RJ, Röper K. A dynamic microtubule cytoskeleton directs medial actomyosin function during tube formation. Dev Cell 2014; 29:562-576. [PMID: 24914560 PMCID: PMC4064686 DOI: 10.1016/j.devcel.2014.03.023] [Citation(s) in RCA: 75] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2013] [Revised: 02/28/2014] [Accepted: 03/27/2014] [Indexed: 12/13/2022]
Abstract
The cytoskeleton is a major determinant of cell-shape changes that drive the formation of complex tissues during development. Important roles for actomyosin during tissue morphogenesis have been identified, but the role of the microtubule cytoskeleton is less clear. Here, we show that during tubulogenesis of the salivary glands in the fly embryo, the microtubule cytoskeleton undergoes major rearrangements, including a 90° change in alignment relative to the apicobasal axis, loss of centrosomal attachment, and apical stabilization. Disruption of the microtubule cytoskeleton leads to failure of apical constriction in placodal cells fated to invaginate. We show that this failure is due to loss of an apical medial actomyosin network whose pulsatile behavior in wild-type embryos drives the apical constriction of the cells. The medial actomyosin network interacts with the minus ends of acentrosomal microtubule bundles through the cytolinker protein Shot, and disruption of Shot also impairs apical constriction. Large-scale rearrangement of microtubules accompanies early tube formation Loss of microtubules leads to loss of apical constriction during tube formation During tubulogenesis, apical constriction is driven by pulsatile medial actomyosin Microtubules and the cytolinker Shot stabilize the medial actomyosin
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Affiliation(s)
- Alexander J R Booth
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Guy B Blanchard
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge CB2 3DY, UK
| | - Richard J Adams
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge CB2 3DY, UK
| | - Katja Röper
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Francis Crick Avenue, Cambridge CB2 0QH, UK.
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Fischer SC, Blanchard GB, Duque J, Adams RJ, Arias AM, Guest SD, Gorfinkiel N. Contractile and mechanical properties of epithelia with perturbed actomyosin dynamics. PLoS One 2014; 9:e95695. [PMID: 24759936 PMCID: PMC3997421 DOI: 10.1371/journal.pone.0095695] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2013] [Accepted: 03/31/2014] [Indexed: 11/18/2022] Open
Abstract
Mechanics has an important role during morphogenesis, both in the generation of forces driving cell shape changes and in determining the effective material properties of cells and tissues. Drosophila dorsal closure has emerged as a reference model system for investigating the interplay between tissue mechanics and cellular activity. During dorsal closure, the amnioserosa generates one of the major forces that drive closure through the apical contraction of its constituent cells. We combined quantitation of live data, genetic and mechanical perturbation and cell biology, to investigate how mechanical properties and contraction rate emerge from cytoskeletal activity. We found that a decrease in Myosin phosphorylation induces a fluidization of amnioserosa cells which become more compliant. Conversely, an increase in Myosin phosphorylation and an increase in actin linear polymerization induce a solidification of cells. Contrary to expectation, these two perturbations have an opposite effect on the strain rate of cells during DC. While an increase in actin polymerization increases the contraction rate of amnioserosa cells, an increase in Myosin phosphorylation gives rise to cells that contract very slowly. The quantification of how the perturbation induced by laser ablation decays throughout the tissue revealed that the tissue in these two mutant backgrounds reacts very differently. We suggest that the differences in the strain rate of cells in situations where Myosin activity or actin polymerization is increased arise from changes in how the contractile forces are transmitted and coordinated across the tissue through ECadherin-mediated adhesion. Altogether, our results show that there is an optimal level of Myosin activity to generate efficient contraction and suggest that the architecture of the actin cytoskeleton and the dynamics of adhesion complexes are important parameters for the emergence of coordinated activity throughout the tissue.
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Affiliation(s)
- Sabine C. Fischer
- Buchmann Institute for Molecular Life Sciences, Department of Biological Sciences, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Guy B. Blanchard
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom
| | - Julia Duque
- Centro de Biología Molecular “Severo Ochoa”, CSIC-UAM, Cantoblanco, Madrid, Spain
| | - Richard J. Adams
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom
| | - Alfonso Martinez Arias
- Buchmann Institute for Molecular Life Sciences, Department of Biological Sciences, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Simon D. Guest
- Department of Engineering, University of Cambridge, Cambridge, United Kingdom
| | - Nicole Gorfinkiel
- Centro de Biología Molecular “Severo Ochoa”, CSIC-UAM, Cantoblanco, Madrid, Spain
- * E-mail:
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17
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Wu M, Adams RJ. Properties of Rasch residual fit statistics. J Appl Meas 2013; 14:339-355. [PMID: 24064576] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
This paper examines the residual-based fit statistics commonly used in Rasch measurement. In particular, the paper analytically examines some of the theoretical properties of the residual-based fit statistics with a view to establishing the inferences that can be made using these fit statistics. More specifically, the relationships between the distributional properties of the fit statistics and sample size are discussed; some research that erroneously concludes that residual-based fit statistics are unstable is reviewed; and finally, it is analytically illustrated that, for dichotomous items, residual-based fit statistics provide a measure of the relative slope of empirical item characteristic curves. With a clear understanding of the theoretical properties of the fit statistics, the use and limitations of these statistics can be placed in the right light.
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Affiliation(s)
- Margaret Wu
- P. O. Box 3011, Strathmore, VIC 3041, Australia,
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18
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Harrison LG, Adams RJ, Holloway DM. Dynamic regulation of growing domains for elongating and branching morphogenesis in plants. Biosystems 2012; 109:488-97. [PMID: 22483851 DOI: 10.1016/j.biosystems.2012.03.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2011] [Revised: 03/06/2012] [Accepted: 03/21/2012] [Indexed: 11/19/2022]
Abstract
With their continuous growth, understanding how plant shapes form is fundamentally linked to understanding how growth rates are controlled across different regions of the plant. Much of a plant's architecture is generated in shoots and roots, where fast growth in tips contrasts with slow growth in supporting stalks. Shapes can be determined by where the boundaries between fast- and slow-growing regions are positioned, determining whether tips elongate, branch, or cease to grow. Across plants, there is a diversity in the cell wall chemistry through which growth operates. However, prototypical morphologies, such as tip growth and branching, suggest there are common dynamic constraints in localizing chemical growth catalysts. We have used Turing-type reaction-diffusion mechanisms to model this spatial localization and the resulting growth trajectories, characterizing the chemistry-growth feedback necessary for maintaining tip growth and for inducing branching. The mechanism defining the boundaries between fast- and slow-growing regions not only affects tip shape, it must be able to form new boundaries when the pattern-forming dynamics break symmetry, for instance in the branching of a tip. In previous work, we used an arbitrary concentration threshold to switch between two dynamic regimes of the growth catalyst in order to define growth boundaries. Here, we present a chemical dynamic basis for this threshold, in which feedback between two pattern-forming mechanisms controls the extent of the regions in which fast growth occurs. This provides a general self-contained mechanism for growth control in plant morphogenesis (not relying on external cues) which can account for both simple tip extension and symmetry-breaking branching phenomena.
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Affiliation(s)
- Lionel G Harrison
- Chemistry Department, University of British Columbia, Vancouver, B.C., Canada
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Blanchard GB, Murugesu S, Adams RJ, Martinez-Arias A, Gorfinkiel N. Cytoskeletal dynamics and supracellular organisation of cell shape fluctuations during dorsal closure. Development 2010; 137:2743-52. [PMID: 20663818 DOI: 10.1242/dev.045872] [Citation(s) in RCA: 175] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Fluctuations in the shape of amnioserosa (AS) cells during Drosophila dorsal closure (DC) provide an ideal system with which to understand contractile epithelia, both in terms of the cellular mechanisms and how tissue behaviour emerges from the activity of individual cells. Using quantitative image analysis we show that apical shape fluctuations are driven by the medial cytoskeleton, with periodic foci of contractile myosin and actin travelling across cell apices. Shape changes were mostly anisotropic and neighbouring cells were often, but transiently, organised into strings with parallel deformations. During the early stages of DC, shape fluctuations with long cycle lengths produced no net tissue contraction. Cycle lengths shortened with the onset of net tissue contraction, followed by a damping of fluctuation amplitude. Eventually, fluctuations became undetectable as AS cells contracted rapidly. These transitions were accompanied by an increase in apical myosin, both at cell-cell junctions and medially, the latter ultimately forming a coherent, but still dynamic, sheet across cells. Mutants with increased myosin activity or actin polymerisation exhibited precocious cell contraction through changes in the subcellular localisation of myosin. thick veins mutant embryos, which exhibited defects in the actin cable at the leading edge, showed similar timings of fluctuation damping to the wild type, suggesting that damping is an autonomous property of the AS. Our results suggest that cell shape fluctuations are a property of cells with low and increasing levels of apical myosin, and that medial and junctional myosin populations combine to contract AS cell apices and drive DC.
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Affiliation(s)
- Guy B Blanchard
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, UK.
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Blanchard GB, Murugesu S, Adams RJ, Martinez-Arias A, Gorfinkiel N. Cytoskeletal dynamics and supracellular organisation of cell shape fluctuations during dorsal closure. J Cell Sci 2010. [DOI: 10.1242/jcs.078279] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Butler LC, Blanchard GB, Kabla AJ, Lawrence NJ, Welchman DP, Mahadevan L, Adams RJ, Sanson B. Cell shape changes indicate a role for extrinsic tensile forces in Drosophila germ-band extension. Nat Cell Biol 2009; 11:859-64. [DOI: 10.1038/ncb1894] [Citation(s) in RCA: 203] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2009] [Accepted: 04/28/2009] [Indexed: 02/04/2023]
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Gorfinkiel N, Blanchard GB, Adams RJ, Martinez Arias A. Mechanical control of global cell behaviour during dorsal closure in Drosophila. Development 2009; 136:1889-98. [PMID: 19403661 PMCID: PMC2680111 DOI: 10.1242/dev.030866] [Citation(s) in RCA: 114] [Impact Index Per Article: 7.6] [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] [Accepted: 03/31/2009] [Indexed: 12/29/2022]
Abstract
Halfway through embryonic development, the epidermis of Drosophila exhibits a gap at the dorsal side covered by an extraembryonic epithelium, the amnioserosa (AS). Dorsal closure (DC) is the process whereby interactions between the two epithelia establish epidermal continuity. Although genetic and biomechanical analysis have identified the AS as a force-generating tissue, we do not know how individual cell behaviours are transformed into tissue movements. To approach this question we have applied a novel image-analysis method to measure strain rates in local domains of cells and performed a kinematic analysis of DC. Our study reveals spatial and temporal differences in the rate of apical constriction of AS cells. We find a slow phase of DC, during which apical contraction of cells at the posterior end predominates, and a subsequent fast phase, during which all the cells engage in the contraction, which correlates with the zippering process. There is a radial gradient of AS apical contraction, with marginal cells contracting earlier than more centrally located cells. We have applied this analysis to the study of mutant situations and associated a particular genotype with quantitative and reproducible changes in the rate of cell contraction and hence in the overall rate of the process. Our mutant analysis reveals the contribution of mechanical elements to the rate and pattern of DC.
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Affiliation(s)
- Nicole Gorfinkiel
- Department of Genetics, University of Cambridge, Cambridge CB2 3EH, UK.
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Meilhac SM, Adams RJ, Morris SA, Danckaert A, Le Garrec JF, Zernicka-Goetz M. Active cell movements coupled to positional induction are involved in lineage segregation in the mouse blastocyst. Dev Biol 2009; 331:210-21. [PMID: 19422818 DOI: 10.1016/j.ydbio.2009.04.036] [Citation(s) in RCA: 136] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2009] [Revised: 04/29/2009] [Accepted: 04/29/2009] [Indexed: 11/19/2022]
Abstract
In the mouse blastocyst, some cells of the inner cell mass (ICM) develop into primitive endoderm (PE) at the surface, while deeper cells form the epiblast. It remained unclear whether the position of cells determines their fate, such that gene expression is adjusted to cell position, or if cells are pre-specified at random positions and then sort. We have tracked and characterised dynamics of all ICM cells from the early to late blastocyst stage. Time-lapse microscopy in H2B-EGFP embryos shows that a large proportion of ICM cells change position between the surface and deeper compartments. Most of this cell movement depends on actin and is associated with cell protrusions. We also find that while most cells are precursors for only one lineage, some give rise to both, indicating that lineage segregation is not complete in the early ICM. Finally, changing the expression levels of the PE marker Gata6 reveals that it is required in surface cells but not sufficient for the re-positioning of deeper cells. We provide evidence that Wnt9A, known to be expressed in the surface ICM, facilitates re-positioning of Gata6-expressing cells. Combining these experimental results with computer modelling suggests that PE formation involves both cell sorting movements and position-dependent induction.
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Armstrong-Wells J, Grimes B, Sidney S, Kronish D, Shiboski SC, Adams RJ, Fullerton HJ. Utilization of TCD screening for primary stroke prevention in children with sickle cell disease. Neurology 2009; 72:1316-21. [PMID: 19365052 DOI: 10.1212/wnl.0b013e3181a110da] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND In 1998, the Stroke Prevention Trial in Sickle Cell Anemia showed a >90% reduction in stroke rates after blood transfusion therapy in children with sickle cell disease (SCD) identified as high risk with transcranial Doppler ultrasonography (TCD) screening. METHODS We studied the utilization of TCD screening in a retrospective cohort of all children with SCD within a large managed care plan from January 1993 to December 2005. Rates of first TCD screening were estimated using life table methods; predictors of TCD were evaluated using Cox proportional hazards regression. Stroke incidence rates were estimated in person-time before (pre-TCD) and after (post-TCD) first TCD. RESULTS The average annual rate of TCD screening in 157 children with SCD was 1.8 per 100 person-years pre-1998, 5.0 from January 1, 1998, to December 31, 1999, and 11.4 after 1999. The only independent predictor of TCD screening was proximity to the vascular laboratory. The annualized stroke rate pre-TCD was 0.44 per 100 person-years, compared to 0.19 post-TCD. CONCLUSIONS Since the Stroke Prevention Trial in Sickle Cell Anemia, the rate of transcranial Doppler ultrasonography (TCD) screening in sickle cell disease (SCD) has increased sixfold within a large health care plan. Children living farther from a vascular laboratory are less likely to be screened. Increased availability of TCD screening could improve the utilization of this effective primary stroke prevention strategy.
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Affiliation(s)
- J Armstrong-Wells
- University of California, San Francisco, Department of Neurology, Box 0114, 505 Parnassus Avenue, San Francisco, CA 94143-0114, USA
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Abstract
How the single-celled egg is transformed through the multicellular embryo into the structurally complex adult remains a significant challenge to developmental biologists today. Historically, fate maps have been used to follow the reorganization of tissue domains through pertinent stages of growth to predict the mechanisms by which the development of form takes place. However, to understand the details of morphogenesis and the causes of errors in its execution, it is essential that we record and reconstruct the precise journeys of all cells and their progeny throughout the course of development. This article presents an overview of the key technologies used in the construction of such dynamic, high-resolution fate maps and highlights their real potential for quantitatively analyzing the physical basis of development.
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Affiliation(s)
- Samantha J. England
- Department of Physiology, Development, and Neuroscience, University of Cambridge, Cambridge, UK
| | - Richard J. Adams
- Department of Physiology, Development, and Neuroscience, University of Cambridge, Cambridge, UK
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Gross H, Hall C, Switzer JA, Adams RJ, Wang S, Hess DC, Nichols FT, Pardue C. USING TPA FOR ACUTE STROKE IN A RURAL SETTING. Neurology 2007; 68:1957-8; author reply 1958. [PMID: 17536059 DOI: 10.1212/01.wnl.0000265360.21157.61] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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27
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Svetic V, Hollway GE, Elworthy S, Chipperfield TR, Davison C, Adams RJ, Eisen JS, Ingham PW, Currie PD, Kelsh RN. Sdf1a patterns zebrafish melanophores and links the somite and melanophore pattern defects in choker mutants. Development 2007; 134:1011-22. [PMID: 17267445 DOI: 10.1242/dev.02789] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Pigment pattern formation in zebrafish presents a tractable model system for studying the morphogenesis of neural crest derivatives. Embryos mutant for choker manifest a unique pigment pattern phenotype that combines a loss of lateral stripe melanophores with an ectopic melanophore ;collar' at the head-trunk border. We find that defects in neural crest migration are largely restricted to the lateral migration pathway, affecting both xanthophores (lost) and melanophores (gained) in choker mutants. Double mutant and timelapse analyses demonstrate that these defects are likely to be driven independently, the collar being formed by invasion of melanophores from the dorsal and ventral stripes. Using tissue transplantation, we show that melanophore patterning depends upon the underlying somitic cells, the myotomal derivatives of which--both slow--and fast-twitch muscle fibres--are themselves significantly disorganised in the region of the ectopic collar. In addition, we uncover an aberrant pattern of expression of the gene encoding the chemokine Sdf1a in choker mutant homozygotes that correlates with each aspect of the melanophore pattern defect. Using morpholino knock-down and ectopic expression experiments, we provide evidence to suggest that Sdf1a drives melanophore invasion in the choker mutant collar and normally plays an essential role in patterning the lateral stripe. We thus identify Sdf1 as a key molecule in pigment pattern formation, adding to the growing inventory of its roles in embryonic development.
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Affiliation(s)
- Valentina Svetic
- Centre for Regenerative Medicine and Developmental Biology Programme, Department of Biology and Biochemistry, University of Bath, Bath BA2 7AY, UK
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England SJ, Blanchard GB, Mahadevan L, Adams RJ. A dynamic fate map of the forebrain shows how vertebrate eyes form and explains two causes of cyclopia. Development 2006; 133:4613-7. [PMID: 17079266 DOI: 10.1242/dev.02678] [Citation(s) in RCA: 98] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Mechanisms for shaping and folding sheets of cells during development are poorly understood. An example is the complex reorganisation of the forebrain neural plate during neurulation, which must fold a sheet into a tube while evaginating two eyes from a single contiguous domain within the neural plate. We, for the first time, track these cell rearrangements to show that forebrain morphogenesis differs significantly from prior hypotheses. We postulate a new model for forebrain neurulation and demonstrate how mutations affecting two signalling pathways can generate cyclopic phenotypes by disrupting normal cell movements or introducing new erroneous behaviours.
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Affiliation(s)
- Samantha J England
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge CB2 3DY, UK
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Affiliation(s)
- H J Fullerton
- University of California, San Francisco, Department of Neurology, Box 0137, San Francisco, CA 94143-0137, USA.
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Abstract
The cellular mechanisms underlying organ formation are largely unknown. We visualized early vertebrate eye morphogenesis at single-cell resolution by in vivo imaging in medaka (Oryzias latipes). Before optic vesicle evagination, retinal progenitor cells (RPCs) modulate their convergence in a fate-specific manner. Presumptive forebrain cells converge toward the midline, whereas medial RPCs remain stationary, predetermining the site of evagination. Subsequent optic vesicle evagination is driven by the active migration of individual RPCs. The analysis of mutants demonstrated that the retina-specific transcription factor rx3 determines the convergence and migration behaviors of RPCs. Hence, the migration of individual cells mediates essential steps of organ morphogenesis.
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Affiliation(s)
- Martina Rembold
- Developmental Biology Unit, European Molecular Biology Laboratory, Meyerhofstrasse 1, 69117 Heidelberg, Germany
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Strauss B, Adams RJ, Papalopulu N. A default mechanism of spindle orientation based on cell shape is sufficient to generate cell fate diversity in polarised Xenopus blastomeres. Development 2006; 133:3883-93. [PMID: 16943269 DOI: 10.1242/dev.02578] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The process of oriented divisions of polarised cells is a recurrent mechanism of cell fate diversification in development. It is commonly assumed that a specialised mechanism of spindle alignment into the axis of polarity is a prerequisite for such systems to generate cell fate diversity. Oriented divisions also take place in the frog blastula, where orientation of the spindle into the apicobasal axis of polarised blastomeres generates inner and outer cells with different fates. Here, we show that, in this system, the spindle orients according to the shape of the cells, a mechanism often thought to be a default. We show that in the embryo, fatedifferentiative, perpendicular divisions correlate with a perpendicular long axis and a small apical surface, but the long axis rather then the size of the apical domain defines the division orientation. Mitotic spindles in rounded, yet polarised, isolated Xenopus blastula cells orient randomly, but align into an experimentally introduced long axis when cells are deformed early in the cell cycle. Unlike other systems of oriented divisions, the spindle aligns at prophase, rotation behaviour is rare and restricted to small angle adjustments. Disruption of astral microtubules leads to misalignment of the spindle. These results show that a mechanism of spindle orientation that depends on cell shape rather than cortical polarity can nevertheless generate cell fate diversity from a population of polarised cells.
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Affiliation(s)
- Bernhard Strauss
- The Wellcome Trust/Cancer Research UK Gurdon Institute, Cambridge, UK
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Valadi N, Silva GS, Bowman LS, Ramsingh D, Vicari P, Filho AC, Massaro AR, Kutlar A, Nichols FT, Adams RJ. Transcranial Doppler ultrasonography in adults with sickle cell disease. Neurology 2006; 67:572-4. [PMID: 16924006 DOI: 10.1212/01.wnl.0000230150.39429.8e] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND Transcranial Doppler (TCD) is used to select children with sickle cell disease (SCD) for primary stroke prevention using regular blood transfusion. Whether it can also identify high stroke risk in adults with SCD is not known. METHODS The authors examined 112 adult patients from two convenience population samples with SCD and 53 healthy control subjects to compare velocities in adults to those reported in children with SCD and to evaluate the influence of age and hematocrit on TCD. RESULTS Adults with SCD had a higher mean time-averaged maximum mean velocity (110.9 +/- 25.7 cm/s) compared with healthy controls (71.1 +/- 12.0 cm/s), and the difference is approximately proportional to their anemia. No cases with velocities >/=200 cm/s (the threshold used in children for prophylactic treatment) were found in this sample. CONCLUSIONS Transcranial Doppler velocities in adults with sickle cell disease (SCD) are lower than those in children with SCD. Velocity criteria used in children cannot be used to stratify risk of stroke in adults.
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Affiliation(s)
- N Valadi
- Department of Neurology, Medical College of Georgia, 1429 Harper St., HF 1154, Augusta, GA 30912, USA
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Gross H, Hall CE, Wang S, Pardue C, Hess DC, Nichols FT, Adams RJ. Prospective reliability of the STRokE DOC Wireless/Site Independent Telemedicine System. Neurology 2006; 66:460. [PMID: 16476968 DOI: 10.1212/01.wnl.0000209203.87339.21] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Adams RJ, Price RD, Clayton DH. Taxonomic revision of Old World members of the feather louse genusColumbicola(Phthiraptera: Ischnocera), including descriptions of eight new species. J NAT HIST 2005. [DOI: 10.1080/00222930500393368] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Adams RJ, Wilson DH, Taylor AW, Daly A, Tursan d'Espaignet E, Dal Grande E, Ruffin RE. Psychological factors and asthma quality of life: a population based study. Thorax 2004; 59:930-5. [PMID: 15516466 PMCID: PMC1746862 DOI: 10.1136/thx.2003.010256] [Citation(s) in RCA: 102] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BACKGROUND Reports of psychological conditions in asthmatic subjects have been limited to certain population groups or convenience samples. A study was undertaken of the prevalence of psychological distress in asthma in the general population and its associations with quality of life. METHODS The WANTS Health and Well-being Survey is a population household interview survey of adults (age > or =18) in Western Australia, the Northern Territory, and South Australia. Data obtained were weighted to the closest census data to provide population representative estimates. Positive answers to two questions: "Have you ever been told by a doctor that you have asthma?" and "Do you still have asthma?" determined current doctor-diagnosed asthma. Other items included the SF-12, the Kessler-10 index of psychological distress, questions on feelings of lack of control in different areas of life, and on mental health conditions. RESULTS From the available sample of 10 080, 7619 interviews were completed (participation rate 74.8%), with 834 people reporting current doctor-diagnosed asthma (11.2%). Psychological distress was more frequent in those with asthma (17.9% v 12.2%, p<0.01) and a higher proportion with asthma were at higher risk for anxiety or depression (40.5% v 31.2%, p<0.01). Mental health conditions were also more common (16.2% v 10.8%, p<0.01), as was the frequency of those who sometimes or always felt a lack of control over their health (33.5% v 24.3%, p<0.01). People with both asthma and psychological distress had significantly lower scores on the SF-12 physical component summary (PCS) than those with either asthma or distress alone. Among those with psychological distress, mental component summary (MCS) scores did not differ between asthmatic and non-asthmatic respondents. In a multiple regression model the frequency of a feeling of lack of control over health-together with age, family's financial situation, education level, and number of days partially unable to work or perform usual duties-was significantly associated with scores on the PCS (r = 0.73, adjusted r2 = 0.54). CONCLUSION These results, from a representative population sample, show that psychological distress and decreased feelings of control are common in asthma and are significantly associated with physical health status.
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Affiliation(s)
- R J Adams
- The Health Observatory, University of Adelaide, South Australia, Australia.
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Ulrich F, Concha ML, Heid PJ, Voss E, Witzel S, Roehl H, Tada M, Wilson SW, Adams RJ, Soll DR, Heisenberg CP. Slb/Wnt11 controls hypoblast cell migration and morphogenesis at the onset of zebrafish gastrulation. Development 2003; 130:5375-84. [PMID: 13129848 PMCID: PMC1414802 DOI: 10.1242/dev.00758] [Citation(s) in RCA: 127] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
During vertebrate gastrulation, highly coordinated cellular rearrangements lead to the formation of the three germ layers, ectoderm, mesoderm and endoderm. In zebrafish, silberblick (slb)/wnt11 regulates normal gastrulation movements by activating a signalling pathway similar to the Frizzled-signalling pathway, which establishes epithelial planar cell polarity (PCP) in Drosophila. However, the cellular mechanisms by which slb/wnt11 functions during zebrafish gastrulation are still unclear. Using high-resolution two-photon confocal imaging followed by computer-assisted reconstruction and motion analysis, we have analysed the movement and morphology of individual cells in three dimensions during the course of gastrulation. We show that in slb-mutant embryos, hypoblast cells within the forming germ ring have slower, less directed migratory movements at the onset of gastrulation. These aberrant cell movements are accompanied by defects in the orientation of cellular processes along the individual movement directions of these cells. We conclude that slb/wnt11-mediated orientation of cellular processes plays a role in facilitating and stabilising movements of hypoblast cells in the germ ring, thereby pointing at a novel function of the slb/wnt11 signalling pathway for the regulation of migratory cell movements at early stages of gastrulation.
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Affiliation(s)
- Florian Ulrich
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01307 Dresden, Germany
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Abstract
BACKGROUND The prevalence of undiagnosed asthma in the general population and the clinical and demographic characteristics of these patients compared with those with diagnosed asthma are unclear. METHODS The North West Adelaide Health Survey (NWAHS) is a population household interview survey of adults (age>18 years) in the north western suburbs of Adelaide, South Australia (regional population 0.6 million). Data obtained were weighted to the closest census data to provide population representative estimates. Positive answers to: "Have you ever had asthma?"; "Has it been confirmed by a doctor?"; "Do you still have asthma?" determined current physician diagnosed asthma. A positive bronchodilator response on spirometric testing according to ATS criteria without a physician's diagnosis determined undiagnosed asthma. Other measures included the SF-12 health survey questionnaire, the Selim index of severity of chronic lung disease, skin allergy tests, and demographic data. RESULTS Of the 3422 individuals interviewed, 2523 (74%) agreed to participate in the clinical assessment. Of these, 292 (11.6%) had asthma, 236 (9.3%) with a doctor's diagnosis of asthma and 56 (2.3%) with undiagnosed asthma defined on spirometric criteria; thus, 19.2% of the total asthma group were undiagnosed. Those undiagnosed were more likely (p<0.05) to be >40 years old, on government benefits, with an income <AUD$40,000. Symptom frequency was similar in the two asthma groups, but mean spirometric values were lower in the undiagnosed group (p<0.05) while positive skin allergy tests were more common in the diagnosed group (p<0.05). SF-12 component summary scores were significantly lower in both asthma groups than in the non-asthma population. Undiagnosed asthma was frequent in men and in those aged >65 years. Health service use over the previous year was similar for both asthma groups. CONCLUSION Undiagnosed asthma is common among the Australian population, with a similar clinical spectrum to those with diagnosed asthma.
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Affiliation(s)
- R J Adams
- The Health Observatory, The Queen Elizabeth Hospital, University of Adelaide, Woodville, South Australia.
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Abstract
Promptly after the notochord domain is specified in the vertebrate dorsal mesoderm, it undergoes dramatic morphogenesis. Beginning during gastrulation, convergence and extension movements change a squat cellular array into a narrow, elongated one that defines the primary axis of the embryo. Convergence and extension might be coupled by a highly organized cellular intermixing known as mediolateral intercalation behavior (MIB). To learn whether MIB drives early morphogenesis of the zebrafish notochord, we made 4D recordings and quantitatively analyzed both local cellular interactions and global changes in the shape of the dorsal mesodermal field. We show that MIB appears to mediate convergence and can account for extension throughout the dorsal mesoderm. Comparing the notochord and adjacent somitic mesoderm reveals that extension can be regulated separately from convergence. Moreover, mutational analysis shows that extension does not require convergence. Hence, a cellular machine separate from MIB that can drive dorsal mesodermal extension exists in the zebrafish gastrula. The likely redundant control of morphogenesis may provide for plasticity at this critical stage of early development.
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Abstract
Cospeciation generally increases the similarity between host and parasite phylogenies. Incongruence between host and parasite phylogenies has previously been explained in terms of host switching, sorting, and duplication events. Here, we describe an additional process, failure of the parasite to speciate in response to host speciation, that may be important in some host-parasite systems. Failure to speciate is likely to occur when gene flow among parasite populations is much higher than that of their hosts. We reconstructed trees from mitochondrial and nuclear DNA sequences for pigeons and doves (Aves: Columbiformes) and their feather lice in the genus Columbicola (Insecta: Phthiraptera). Although comparisons of the trees from each group revealed a significant amount of cospeciation, there was also a significant degree of incongruence. Cophylogenetic analyses generally indicated that host switching may be an important process in the history of this host-parasite association. Using terminal sister taxon comparisons, we also identified three apparent cases where the host has speciated but the associated parasite has not. In two of these cases of failure to speciate, these comparisons involve allopatric sister taxa of hosts whose lice also occur on hosts sympatric with both of the allopatric sisters. These additional hosts for generalist lice may promote gene flow with lice on the allopatric sister species. Relative rate comparisons for the mitochondrial cytochrome oxidase I gene indicate that molecular substitution occurs about 11 times faster in lice than in their avian hosts.
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Affiliation(s)
- Kevin P Johnson
- Illinois Natural History Survey, 607 East Peabody Drive, Champaign, Illinois 61820, USA
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Johnson KP, Cruickshank RH, Adams RJ, Smith VS, Page RDM, Clayton DH. Dramatically elevated rate of mitochondrial substitution in lice (Insecta: Phthiraptera). Mol Phylogenet Evol 2003; 26:231-42. [PMID: 12565034 DOI: 10.1016/s1055-7903(02)00342-1] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Few estimates of relative substitution rates, and the underlying mutation rates, exist between mitochondrial and nuclear genes in insects. Previous estimates for insects indicate a 2-9 times faster substitution rate in mitochondrial genes relative to nuclear genes. Here we use novel methods for estimating relative rates of substitution, which incorporate multiple substitutions, and apply these methods to a group of insects (lice, Order: Phthiraptera). First, we use a modification of copath analysis (branch length regression) to construct independent comparisons of rates, consisting of each branch in a phylogenetic tree. The branch length comparisons use maximum likelihood models to correct for multiple substitution. In addition, we estimate codon-specific rates under maximum likelihood for the different genes and compare these values. Estimates of the relative synonymous substitution rates between a mitochondrial (COI) and nuclear (EF-1alpha) gene in lice indicate a relative rate of several 100 to 1. This rapid relative mitochondrial rate (>100 times) is at least an order of magnitude faster than previous estimates for any group of organisms. Comparisons using the same methods for another group of insects (aphids) reveals that this extreme relative rate estimate is not simply attributable to the methods we used, because estimates from aphids are substantially lower. Taxon sampling affects the relative rate estimate, with comparisons involving more closely related taxa resulting in a higher estimate. Relative rate estimates also increase with model complexity, indicating that methods accounting for more multiple substitution estimate higher relative rates.
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Affiliation(s)
- Kevin P Johnson
- Illinois Natural History Survey, 607 East Peabody Drive, Champaign 61820, USA.
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Abstract
Activities of a variety of signaling proteins that regulate embryogenesis are limited by endogenous antagonists. The zebrafish Nodal-related ligands, Squint and Cyclops, and their antagonists, Lefty1 and Lefty2, belong to the TGFbeta-related protein superfamily, whose members have widespread biological activities. Among other activities, Nodals direct the formation of most mesendoderm. By inducing their own transcription and that of the Lefties, Nodal signals establish positive and negative autoregulatory loops. To investigate how these autoregulatory pathways regulate development, we depleted zebrafish embryos of Lefty1 and/or Lefty2 by using antisense morpholino oligonucleotides. Loss of Lefty1 causes aberrations during somitogenesis stages, including left-right patterning defects, whereas Lefty2 depletion has no obvious consequences. Depletion of both Lefty1 and Lefty2, by contrast, causes unchecked Nodal signaling, expansion of mesendoderm, and loss of ectoderm. The expansion of mesendoderm correlates with an extended period of rapid cellular internalization and a failure of deep-cell epiboly. The gastrulation defects of embryos depleted of Lefty1 and Lefty2 result from the deregulation of Squint signaling. In contrast, deregulation of Cyclops does not affect morphology or the transcription of Nodal target genes during gastrulation. Furthermore, we find that Cyclops is specifically required for the maintenance of lefty1 and lefty2 transcription.
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Affiliation(s)
- Benjamin Feldman
- Division of Developmental Biology, National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, United Kingdom
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Abstract
Sickle cell disease affects many organ systems, but one of the major morbidities is brain disease, especially stroke. In this paper, the etiology, diagnosis, treatment, and prevention of clinical stroke, as well as so-called "silent stroke," are examined. Risk factors, diagnostic tools, and data from prevention and treatment studies as well as issues pertaining to neuropsychological function, especially in younger patients, are discussed and current best options for treatment considered.
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Affiliation(s)
- R J Adams
- Department of Neurology, HB-2060, Medical College of Georgia, 1467 Harper Street, Augusta GA 30912-3200, USA
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Reger DL, Huff MF, Knox SJ, Adams RJ, Apperley DC, Harris RK. Solid-state tin-119 NMR studies of poly(pyrazolyl)borate complexes of tin(II). Correlation of solution- and solid-state structures. Inorg Chem 2002. [DOI: 10.1021/ic00072a049] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Abstract
Some species of parasites occur on a wide range of hosts while others are restricted to one or a few host species. The host specificity of a parasite species is determined, in part, by its ability to disperse between host species. Dispersal limitations can be studied by exploring the genetic structure of parasite populations both within a single species of host and across multiple host species. In this study we examined the genetic structure in the mitochondrial cytochrome oxidase I (COI) gene of two genera of lice (Insecta: Phthiraptera) occurring on multiple sympatric species of doves in southern North and Central America. One genus, Columbicola, is generally less host-specific than the other, Physconelloides. For both genera we identified substantial genetic differentiation between populations of conspecific lice on different host species, generally 10-20% sequence divergence. This level of divergence is in the range of that often observed between species of these two genera. We used nested clade analysis to explore fine scale genetic structure within species of these feather lice. We found that species of Physconelloides exhibited more genetic structure, both among hosts and among geographical localities, than did species of Columbicola. In many cases, single haplotypes within species of Columbicola are distributed on multiple host species. Thus, the population genetic structure of species of Physconelloides reveals evidence of geographical differentiation on top of high host species specificity. Underlying differences in dispersal biology probably explain the differences in population genetic structure that we observed between Columbicola and Physconelloides.
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Pegelow CH, Wang W, Granger S, Hsu LL, Vichinsky E, Moser FG, Bello J, Zimmerman RA, Adams RJ, Brambilla D. Silent infarcts in children with sickle cell anemia and abnormal cerebral artery velocity. Arch Neurol 2001; 58:2017-21. [PMID: 11735775 DOI: 10.1001/archneur.58.12.2017] [Citation(s) in RCA: 96] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
BACKGROUND A substantial minority of neurologically normal children with sickle cell disease have lesions consistent with cerebral infarction as seen on magnetic resonance imaging (MRI). OBJECTIVES To determine if transfusion therapy affects the rate at which silent infarcts develop and to evaluate the contribution of MRI of the brain to stroke prediction by transcranial Doppler (TCD) ultrasonography. STUDY DESIGN Children with elevated TCD ultrasonographic velocity were randomized to receive long-term transfusion therapy or standard care. Magnetic resonance imaging of the brain was obtained at randomization, annually, and with clinical neurologic events. The risk for new silent lesions and/or stroke was compared for each treatment arm. RESULTS Among the 37% of subjects with silent infarcts, those receiving standard care were significantly more likely to develop new silent lesions or stroke than were those who received transfusion therapy. For subjects receiving standard care, those with lesions at baseline were significantly more likely to develop stroke or new silent lesions than those whose MRI studies showed no abnormality. CONCLUSIONS Transfusion therapy lowers the risk for new silent infarct or stroke for children having both abnormal TCD ultrasonographic velocity and silent infarct. However, those with both abnormalities who are not provided transfusion therapy are at higher risk for developing a new silent infarct or stroke than are those whose initial MRI showed no abnormality. The finding of a silent infarct reinforces the need for TCD ultrasonographic screening and consideration of transfusion therapy if the abnormalities are seen. Similarly, elevated TCD ultrasonographic velocity warrants MRI of the brain because children with both abnormalities seem to be at increased risk for developing new silent infarct or stroke.
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Affiliation(s)
- C H Pegelow
- Department of Pediatrics (R-131), University of Miami School of Medicine, PO Box 016960, Miami, FL 33101, USA.
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Miller ST, Wright E, Abboud M, Berman B, Files B, Scher CD, Styles L, Adams RJ. Impact of chronic transfusion on incidence of pain and acute chest syndrome during the Stroke Prevention Trial (STOP) in sickle-cell anemia. J Pediatr 2001; 139:785-9. [PMID: 11743502 DOI: 10.1067/mpd.2001.119593] [Citation(s) in RCA: 153] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
OBJECTIVE The Stroke Prevention Trial (STOP) demonstrated that chronic transfusion is highly effective in reducing the risk of stroke in children with sickle-cell disease and an abnormal transcranial Doppler ultrasonography examination result. Our objective was to determine whether chronic transfusion therapy reduces the incidence of pain and acute chest syndrome. METHODS During STOP, 130 children with sickle-cell anemia or sickle beta(0)-thalassemia and abnormal transcranial Doppler ultrasonography examination result were randomly assigned to chronic transfusion (n = 63) or observation (n = 67). In addition to monitoring for stroke, nonneurologic sickle-cell complications were identified and recorded. RESULTS Mean age at STOP study entry was 8.3 +/- 3.3 years, and mean follow-up was 19.6 +/- 6.5 months. Hospitalization rates (based on intent-to-treat analysis) for acute chest syndrome were 4.8 and 15.3 per 100 patient-years (P =.0027) and for pain were 16.2 and 27.6 per 100 patient-years (P =.13) in the chronic transfusion and observed groups, respectively. If analyzed according to treatment actually received, the difference in pain rate becomes significant (9.7 vs 27.1 events per 100 patient-years, P =.014), and transfusion remains protective from acute chest syndrome (2.2 vs 15.7 events per 100 patient-years, P =.0001). CONCLUSIONS Compliance with aggressive chronic transfusion reduces the frequency of acute chest syndrome and pain episodes.
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Affiliation(s)
- S T Miller
- State University of New York-Downstate Medical Center/Kings County Hospital Center, Brooklyn, NY 11203, USA
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Abstract
OBJECTIVE Peak flow meters (PFM) continue to be recommended as an important part of asthma self-management plans. It remains unclear if there is an advantage in using PFM in people with moderate-to severe asthma who are not poor perceivers of bronchoconstriction. METHODOLOGY Prospective, randomized controlled trial of 134 adults with moderate-to-severe asthma who did not have evidence of poor perception of bronchoconstriction on histamine challenge testing, who were recruited from inpatients and outpatients of a university teaching hospital. Comparison was made over 12 months of the effectiveness of written action plans using either peak flow monitoring or symptoms to guide management. Subjects were contacted at monthly intervals by telephone for reinforcement and evaluation of use of the action plans, and to provide ongoing education. Spirometry and PD20 histamine were measured at 3-monthly intervals. Measures of health care utilization and morbidity (asthma exacerbations; hospitalizations; emergency department (ED) visits; days absent from work or school due to asthma; medication use and a self-rating of asthma severity) were made monthly. A psychosocial questionnaire (attitudes and beliefs, state-trait anxiety, denial) was given at entry and at 12-months or at withdrawal from the study. RESULTS There were significant improvements for both groups for hospitalizations, ED visits, days off from school or work, and PD20 histamine, but no between-group differences. Appropriate use of action plans was 85% in the symptoms group and 86% in the PFM group. For all subjects, those who subsequently had an ED visit had significantly higher levels of denial (P=0.04) and lower scores for self-confidence (P=0.04), compared to those who did not have an ED visit. CONCLUSIONS Use of written action plans, combined with regular contact to reinforce self-management, improved airway reactivity and reduced health care utilization. However, use of PFM was not superior to symptom-based plans.
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Affiliation(s)
- R J Adams
- Department of Medicine, The University of Adelaide, Queen Elizabeth Hospital Campus, Woodville Road, Woodville, SA, Australia.
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Zink MC, Coleman GD, Mankowski JL, Adams RJ, Tarwater PM, Fox K, Clements JE. Increased macrophage chemoattractant protein-1 in cerebrospinal fluid precedes and predicts simian immunodeficiency virus encephalitis. J Infect Dis 2001; 184:1015-21. [PMID: 11574916 DOI: 10.1086/323478] [Citation(s) in RCA: 129] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2001] [Revised: 06/19/2001] [Indexed: 11/04/2022] Open
Abstract
Macrophage chemoattractant protein-1 (MCP-1) may be a key trigger for the influx of macrophages into the brain in human immunodeficiency virus (HIV) encephalitis. In this study, simian immunodeficiency virus-infected macaques that developed moderate-to-severe encephalitis had significantly higher MCP-1 levels in cerebrospinal fluid (CSF) than in plasma as early as 28 days after inoculation, which was before the development of brain lesions. In contrast, CSF:plasma MCP-1 ratios remained constant at preinoculation levels in macaques that developed minimal or no encephalitis. Abundant MCP-1 protein and mRNA were detected in both macrophages and astrocytes in the brain. Macaques with increased MCP-1 in CSF had significantly greater expression of markers of macrophage and microglia activation and infiltration (CD68; P= .003) and astrocyte activation (glial fibrillary acidic protein; P= .019 and P= .031 in white and gray matter, respectively). The results suggest that the CSF:plasma MCP-1 ratio may be a valuable prognostic marker for the development of HIV-induced central nervous system disease.
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Affiliation(s)
- M C Zink
- Division of Comparative Medicine, Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287, USA.
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Abstract
The Stroke Prevention in Sickle Cell Disease (STOP) trial used transcranial Doppler (TCD) to screen children with sickle cell disease with no history of stroke. Children (who consented) who had time-averaged mean of the maximum (TAMM) velocities in the middle cerebral artery and/or distal internal carotid artery were randomized to transfusion or standard. Over a slightly more than 20-month average follow-up, there were 11 strokes in the standard care arm and 1 stroke in the transfusion arm. This study has caused a great deal of interest in using TCD to screen children with sickle cell disease. For the STOP TCD data to be applied appropriately, it is necessary for users of TCD to understand how the STOP TCD examinations were performed, how the TCD velocities were measured, and which velocities were used. This article will review the STOP TCD scanning protocol and the reading protocol and review the TAMM velocity and how it differs from other velocity measurements.
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Affiliation(s)
- F T Nichols
- Department of Neurology/BP 3147, Medical College of Georgia, Augusta, GA 30912, USA.
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