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Francis HW, Papel I, Lina I, Koch W, Tunkel D, Fuchs P, Lin S, Kennedy D, Ruben R, Linthicum F, Marsh B, Best S, Carey J, Lane A, Byrne P, Flint P, Eisele DW. Otolaryngology-head and neck surgery at Johns Hopkins: The first 100 years (1914-2014). Laryngoscope 2015; 125 Suppl 9:S1-35. [PMID: 26297867 PMCID: PMC4696071 DOI: 10.1002/lary.25490] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/15/2015] [Indexed: 12/19/2022]
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Bradley A, Mason KA, Rodrigues MA, Tang CM, Wood M, Lattey K, Byrne P, Ross M, Maxwell S, Qureshi ZU. Tips for Junior Doctors and Medical Students: Writing and Publishing Undergraduate Textbooks. INTERNATIONAL JOURNAL OF MEDICAL STUDENTS 2015. [DOI: 10.5195/ijms.2015.193] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Ahmed K, Bennett DM, Halder N, Byrne P. Medfest: the effect of a national medical film festival on attendees' attitudes to psychiatry and psychiatrists and medical students' attitudes to a career in psychiatry. ACADEMIC PSYCHIATRY : THE JOURNAL OF THE AMERICAN ASSOCIATION OF DIRECTORS OF PSYCHIATRIC RESIDENCY TRAINING AND THE ASSOCIATION FOR ACADEMIC PSYCHIATRY 2015; 39:335-338. [PMID: 25034954 DOI: 10.1007/s40596-014-0184-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2014] [Accepted: 06/11/2014] [Indexed: 06/03/2023]
Abstract
OBJECTIVE The authors proposed that a national film festival organized by psychiatrists could change attendees' views toward psychiatry and psychiatrists positively and increase the numbers of medical students considering psychiatry as a career. METHODS Medfest held events at nine UK universities in 2011. The program consisted of short films (The Family Doctor, Shadowscan, Beards & Bow Ties) and panelist discussions. Data were gathered using an anonymous "before and after" questionnaire. RESULTS A total of 450 attendees across all sites returned 377 feedback forms (84 % response rate). Views of psychiatry and psychiatrists changed for the better for 42 % (98 % of those who answered the question) and 40 % (96 % of those who answered the question) of all respondents, respectively. Respondents' views were significantly more likely to change for the better than for the worse toward both psychiatry (p < 0.001) and psychiatrists (p < 0.001). Post-event, 46 % of the 232 medical students that attended were more likely to consider a career in psychiatry (48 % of those who answered the question). CONCLUSIONS A multicenter film festival organized by psychiatrists was associated with more positive attitudes to psychiatry and psychiatrists and an increase in students considering psychiatry as a career. The festival is now an annual event, continuing to expand.
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Simpson GW, Byrne P, Gabbay MB, Rannard A. Understanding illness experiences of employees with common mental health disorders. Occup Med (Lond) 2015; 65:367-72. [DOI: 10.1093/occmed/kqv047] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Dey JK, Ishii M, Boahene KDO, Byrne P, Ishii LE. Impact of facial defect reconstruction on attractiveness and negative facial perception. Laryngoscope 2015; 125:1316-21. [DOI: 10.1002/lary.25130] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/10/2014] [Indexed: 11/05/2022]
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Gabbay MB, Goodall M, Capewell S, Bowers P, Kennedy LA, Byrne P, Barton GR, Martindale AM. Authors' reply to comments made about our article 'Food for thought'. J Public Health (Oxf) 2014; 37:749-50. [PMID: 25538146 DOI: 10.1093/pubmed/fdu111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Goodall M, Barton GR, Bower P, Byrne P, Cade JE, Capewell S, Cleghorn CL, Kennedy LA, Martindale AM, Roberts C, Woolf S, Gabbay MB. Food for thought: pilot randomized controlled trial of lay health trainers supporting dietary change to reduce cardiovascular disease in deprived communities. J Public Health (Oxf) 2014; 36:635-43. [PMID: 24277778 DOI: 10.1093/pubmed/fdt112] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Cardiovascular disease (CVD) accounts for 30% of UK deaths. It is associated with modifiable lifestyle factors, including insufficient consumption of fruit and vegetables (F&V). Lay health trainers (LHTs) offer practical support to help people develop healthier behaviour and lifestyles. Our two-group pilot randomized controlled trial (RCT) investigated the effectiveness of LHTs at promoting a heart-healthy lifestyle among adults with at least one risk factor for CVD to inform a full-scale RCT. METHODS Eligible adults (aged 21-78 years), recruited from five practices serving deprived populations, were randomized to health information leaflets plus LHTs' support for 3 months (n = 76) versus health information leaflets alone (n = 38). RESULTS We recruited 114 participants, with 60% completing 6 month follow-up. Both groups increased their self-reported F&V consumption and we found no evidence for LHTs' support having significant added impact. Most participants were relatively less deprived, as were the LHTs we were able to recruit and train. CONCLUSIONS Our pilot demonstrated that an LHT's RCT whilst feasible faces considerable challenges. However, to justify growing investment in LHTs, any behaviour changes and sustained impact on those at greatest need should be demonstrated in an independently evaluated, robust, fully powered RCT.
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King C, Sarabipour S, Byrne P, Leahy DJ, Hristova K. The FRET signatures of noninteracting proteins in membranes: simulations and experiments. Biophys J 2014; 106:1309-17. [PMID: 24655506 DOI: 10.1016/j.bpj.2014.01.039] [Citation(s) in RCA: 75] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2013] [Revised: 01/08/2014] [Accepted: 01/27/2014] [Indexed: 11/30/2022] Open
Abstract
Förster resonance energy transfer (FRET) experiments are often used to study interactions between integral membrane proteins in cellular membranes. However, in addition to the FRET of sequence-specific interactions, these experiments invariably record a contribution due to proximity FRET, which occurs when a donor and an acceptor approach each other by chance within distances of ∼100 Å. This effect does not reflect specific interactions in the membrane and is frequently unappreciated, despite the fact that its magnitude can be significant. Here we develop a computational description of proximity FRET, simulating the cases of proximity FRET when fluorescent proteins are used to tag monomeric, dimeric, trimeric, and tetrameric membrane proteins, as well as membrane proteins existing in monomer-dimer equilibria. We also perform rigorous experimental measurements of this effect, by identifying membrane receptors that do not associate in mammalian membranes. We measure the FRET efficiencies between yellow fluorescent protein and mCherry-tagged versions of these receptors in plasma-membrane-derived vesicles as a function of receptor concentration. Finally, we demonstrate that the experimental measurements are well described by our predictions. The work presented here brings additional rigor to FRET-based studies of membrane protein interactions, and should have broad utility in membrane biophysics research.
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Zuber T, Holm D, Byrne P, Ducreux L, Taylor M, Kaiser M, Stushnoff C. Optimization of in vitro inhibition of HT-29 colon cancer cell cultures by Solanum tuberosum L. extracts. Food Funct 2014; 6:72-83. [PMID: 25338312 DOI: 10.1039/c4fo00649f] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Secondary metabolites in potato have been reported to possess bioactive properties, including growth inhibition of cancer cells. Because potatoes are widely consumed globally, potential health benefits may have broad application. Thus we investigated growth inhibition of HT-29 colon cancer cell cultures by extracts from 13 diverse genetic breeding clones. Extracts from three pigmented selections (CO97226-2R/R, CO97216-1P/P, CO04058-3RW/RW) inhibited growth of in vitro HT-29 cell cultures more effectively than other clones tested. While inhibition was highest from pigmented selections and pigmented tuber tissue sectors, not all pigmented breeding lines tested had appreciable inhibitory properties. Thus, inhibition was not uniquely linked to pigmentation. Immature tubers had the highest inhibitory properties, and in most cases mature tubers retained very low inhibition properties. Flowers and skins inhibited strongly at lower extract concentrations. An extract consisting of 7.2 mg mL⁻¹ cell culture medium was the lowest effective concentration. While raw tuber extracts inhibited most effectively, a few clones at higher concentrations retained inhibition after cooking. Heated whole tubers retained higher inhibition than heated aqueous extracts. While all aqueous extracts from the two tuber selections (CO97216-1P/P and CO97226-2R/R) inhibited HT-29 cell cultures, inhibition was significantly enhanced in purple pigmented tubers of CO97216-1P/P prepared cryogenically as liquid nitrogen powders compared to extracts from freeze dried samples. Upregulation of caspase-3 protease activity, indicative of apoptosis, was highest among the most inhibitory clone samples. The unique sectorial red pigment expressing selection (CO04058-3RW/RW) provided a model system that isolated expression in pigmented sectors, and thus eliminated developmental, environmental and genetic confounding.
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Liu Y, Byrne P, Wang H, Koltick D, Zheng W, Nie LH. A compact DD neutron generator-based NAA system to quantify manganese (Mn) in bone in vivo. Physiol Meas 2014; 35:1899-911. [PMID: 25154883 DOI: 10.1088/0967-3334/35/9/1899] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
A deuterium-deuterium (DD) neutron generator-based neutron activation analysis (NAA) system has been developed to quantify metals, including manganese (Mn), in bone in vivo. A DD neutron generator with a flux of up to 3*10(9) neutrons s(-1) was set up in our lab for this purpose. Optimized settings, including moderator, reflector, and shielding material and thickness, were selected based on Monte Carlo (MC) simulations conducted in our previous work. Hand phantoms doped with different Mn concentrations were irradiated using the optimized DD neutron generator irradiation system. The Mn characteristic γ-rays were collected by an HPGe detector system with 100% relative efficiency. The calibration line of the Mn/calcium (Ca) count ratio versus bone Mn concentration was obtained (R(2) = 0.99) using the hand phantoms. The detection limit (DL) was calculated to be about 1.05 μg g(-1) dry bone (ppm) with an equivalent dose of 85.4 mSv to the hand. The DL can be reduced to 0.74 ppm by using two 100% HPGe detectors. The whole body effective dose delivered to the irradiated subject was calculated to be about 17 μSv. Given the average normal bone Mn concentration of 1 ppm in the general population, this system is promising for in vivo bone Mn quantification in humans.
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Dunn L, Byrne P, Lloyd-Williams M. ‘RING US IF YOU NEED US’: THE IMPORTANCE OF REASSURANCE TO FAMILY CAREGIVERS PROVIDING HOME-BASED END-OF-LIFE CARE. BMJ Support Palliat Care 2014. [DOI: 10.1136/bmjspcare-2014-000653.43] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Liu Y, Koltick D, Byrne P, Wang H, Zheng W, Nie LH. Development of a transportable neutron activation analysis system to quantify manganese in bone in vivo: feasibility and methodology. Physiol Meas 2013; 34:1593-609. [PMID: 24165395 PMCID: PMC4154064 DOI: 10.1088/0967-3334/34/12/1593] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
This study was conducted to investigate the methodology and feasibility of developing a transportable neutron activation analysis (NAA) system to quantify manganese (Mn) in bone using a portable deuterium-deuterium (DD) neutron generator as the neutron source. Since a DD neutron generator was not available in our laboratory, a deuterium-tritium (DT) neutron generator was used to obtain experimental data and validate the results from Monte Carlo (MC) simulations. After validation, MC simulations using a DD generator as the neutron source were then conducted. Different types of moderators and reflectors were simulated, and the optimal thicknesses for the moderator and reflector were determined. To estimate the detection limit (DL) of the system, and to observe the interference of the magnesium (Mg) γ line at 844 keV to the Mn γ line at 847 keV, three hand phantoms with Mn concentrations of 30 parts per million (ppm), 150 ppm, and 500 ppm were made and irradiated by the DT generator system. The Mn signals in these phantoms were then measured using a 50% high-efficiency high-purity germanium (HPGe) detector. The DL was calculated to be about 4.4 ppm for the chosen irradiation, decay, and measurement time. This was calculated to be equivalent to a DL of about 3.3 ppm for the DD generator system. To achieve this DL with one 50% high-efficiency HPGe detector, the dose to the hand was simulated to be about 37 mSv, with the total body equivalent dose being about 23µSv. In conclusion, it is feasible to develop a transportable NAA system to quantify Mn in bone in vivo with an acceptable radiation exposure to the subject.
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Boyer J, Byrne P, Cassman K, Cooper M, Delmer D, Greene T, Gruis F, Habben J, Hausmann N, Kenny N, Lafitte R, Paszkiewicz S, Porter D, Schlegel A, Schussler J, Setter T, Shanahan J, Sharp R, Vyn T, Warner D, Gaffney J. The U.S. drought of 2012 in perspective: A call to action. GLOBAL FOOD SECURITY-AGRICULTURE POLICY ECONOMICS AND ENVIRONMENT 2013. [DOI: 10.1016/j.gfs.2013.08.002] [Citation(s) in RCA: 83] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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Yoo DH, Racewicz A, Brzezicki J, Yatsyshyn R, Tobias Arteaga E, Baranauskaite A, Abud-Mendoza C, Navarra S, Eullaran R, Kadinov V, Goecke Sariego I, Byrne P, Park W, Lee SJ, Kim HU, Müller-Ladner U. OP0068 A Phase 3 Randomised Controlled Trial to Compare CT-P13 with Infliximab in Patients with Active Rheumatoid Arthritis: 54 Week Results from the Planetra Study. Ann Rheum Dis 2013. [DOI: 10.1136/annrheumdis-2013-eular.273] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Dyavanapalli J, Byrne P, Mendelowitz D. Activation of D2-like dopamine receptors inhibits GABA and glycinergic neurotransmission to pre-motor cardiac vagal neurons in the nucleus ambiguus. Neuroscience 2013; 247:213-26. [PMID: 23727508 DOI: 10.1016/j.neuroscience.2013.05.039] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2013] [Revised: 05/17/2013] [Accepted: 05/21/2013] [Indexed: 12/16/2022]
Abstract
The parasympathetic control of heart rate arises from premotor cardiac vagal neurons (CVNs) located in the nucleus ambiguus (NA). Previous microinjection studies in NA show that dopamine evokes a decrease in heart rate, but the underlying mechanisms responsible for these responses were not identified. This study tested whether dopamine modulates inhibitory GABAergic and glycinergic and/or excitatory glutamatergic neurotransmission to CVNs. Retrogradely labeled CVNs were identified in an in vitro rat brainstem slice preparation and synaptic events were recorded using whole cell voltage clamp techniques. Bath application of dopamine (100 μM) had no effect on excitatory synaptic events, but reversibly inhibited the frequency (but not amplitude) of GABAergic inhibitory postsynaptic currents (IPSCs) in CVNs. Similarly, dopamine (10 μM and 100 μM) inhibited glycinergic IPSC frequency by ~50% and 70% respectively. The reduction in inhibitory neurotransmission to CVNs by dopamine was prevented by the sodium channel blocker TTX (1μM) indicating that the dopamine mediated effects were action potential dependent. Dopamine evoked responses were mimicked by the D2-like receptor agonist, Quinpirole but not D1-like receptor agonist, SKF 38393. In addition, the dopamine mediated depression of inhibitory synaptic responses were prevented by the D2-like receptor antagonist sulpiride, but not by D1-like or adrenergic or serotonergic receptor antagonists, suggesting that these responses were D2-like receptor mediated and not D1-like or adrenergic or 5-HT receptor mediated. These data suggest that dopamine acts via dis-inhibition, and diminishes inhibitory GABAergic and glycinergic neurotransmission to CVNs, which would be predicted to increase parasympathetic activity to the heart and evoke a bradycardia.
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Byrne P, Reid I, Wood PJ. Stormflow hydrochemistry of a river draining an abandoned metal mine: the Afon Twymyn, central Wales. ENVIRONMENTAL MONITORING AND ASSESSMENT 2013; 185:2817-2832. [PMID: 22752965 DOI: 10.1007/s10661-012-2751-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2012] [Accepted: 06/14/2012] [Indexed: 06/01/2023]
Abstract
Contaminated drainage from metal mines is a serious water-quality problem facing nations that exploit metal mineral resources. Measurements of river hydrochemistry during baseflow are common at mine sites, whilst detailed hydrochemical information regarding stormflow is limited and often confined to a single event. This study investigates the seasonal evolution of stormflow hydrochemistry at an abandoned metal mine in central Wales, UK, and the possible sources and mechanisms of metal release. Significant flushing of metals was observed during stormflow events, resulting in concentrations that severely exceeded water-quality guidelines. The relationship between metal concentrations and river discharge suggests dissolution of efflorescent metal sulphates on the surface of the mine spoil as the principal source of the contamination. High fluxes of Pb during stormflows are linked to extended periods of dry weather prior to storm events that produced water table drawdown and encouraged oxidation of Pb sulphide in the mine spoil. However, some Pb flushing also occurred following wet antecedent conditions. It is suggested that Fe oxide reduction in mine spoil and translatory flows involving metal-rich pore waters results in flushing during wetter periods. Detailed measurements of stormflow hydrochemistry at mine sites are essential for accurate forecasting of long-term trends in metals flux to understand metal sources and mechanisms of release, to assess potential risks to water quality and instream ecology, and to gauge the potential effectiveness of remediation. In order to protect riverine and riparian ecosystems, it is suggested that routine monitoring of stormflows becomes part of catchment management in mining-impacted regions.
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Collar R, Lyford-Pike S, Byrne P. Algorithmic Approach to Lower Lid Blepharoplasty. Facial Plast Surg 2013; 29:32-9. [DOI: 10.1055/s-0033-1333836] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
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Byrne P, Reid I, Wood PJ. Changes in macroinvertebrate community structure provide evidence of neutral mine drainage impacts. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2013; 15:393-404. [PMID: 25208704 DOI: 10.1039/c2em30447c] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Contamination of aquatic environments as a consequence of metal mining is an international issue. Most historic studies have considered the impact of acid mine drainage (pH < 6) on instream communities and comparatively little attention has been given to sites where drainage is typically circum-neutral (6 > pH < 8). Here, the impacts of historic mining activities on the benthic macroinvertebrate community of a circum-neutral river in Central Wales are assessed. Biotic and diversity indices, widely used for biomonitoring purposes, indicate aquatic macroinvertebrate assemblages within the Afon Twymyn to be in a good condition, despite severe metal contamination of bed sediments and river water. However, Canonical Correspondence Analysis identifies differences in community structure between mining impacted and unimpacted reaches of the river associated with chalcophile (Zn, Pb, Cu, Cd) and common (Fe and Mn) metals. Stream pH was not a significant factor structuring the macroinvertebrate community. Widely utilised macroinvertebrate indices failed to identify impacts at the community level because they either seek to identify impacts of a specific contaminant or are dependent on a model community response to a given stress. The nature of metal mine discharges is temporally complex, having highly variable chemical signatures and as a result, care is advised when interpreting and modelling community impacts. The use of standard macroinvertebrate biotic and diversity indices in the context of the EU Water Framework Directive could lead to erroneous classifications of aquatic ecosystem health when used for bio-monitoring rivers affected by neutral mine drainage where other indicators are unavailable.
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Boahene K, Byrne P, Schaitkin BM. Facial reanimation: discussion and debate. Facial Plast Surg Clin North Am 2013; 20:383-402. [PMID: 22910026 DOI: 10.1016/j.fsc.2012.05.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Farshadmanesh F, Byrne P, Wang H, Corneil BD, Crawford JD. Relationships between neck muscle electromyography and three-dimensional head kinematics during centrally induced torsional head perturbations. J Neurophysiol 2012; 108:2867-83. [PMID: 22956790 DOI: 10.1152/jn.00312.2012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The relationship between neck muscle electromyography (EMG) and torsional head rotation (about the nasooccipital axis) is difficult to assess during normal gaze behaviors with the head upright. Here, we induced acute head tilts similar to cervical dystonia (torticollis) in two monkeys by electrically stimulating 20 interstitial nucleus of Cajal (INC) sites or inactivating 19 INC sites by injection of muscimol. Animals engaged in a simple gaze fixation task while we recorded three-dimensional head kinematics and intramuscular EMG from six bilateral neck muscle pairs. We used a cross-validation-based stepwise regression to quantitatively examine the relationships between neck EMG and torsional head kinematics under three conditions: 1) unilateral INC stimulation (where the head rotated torsionally toward the side of stimulation); 2) corrective poststimulation movements (where the head returned toward upright); and 3) unilateral INC inactivation (where the head tilted toward the opposite side of inactivation). Our cross-validated results of corrective movements were slightly better than those obtained during unperturbed gaze movements and showed many more torsional terms, mostly related to velocity, although some orientation and acceleration terms were retained. In addition, several simplifying principles were identified. First, bilateral muscle pairs showed similar, but opposite EMG-torsional coupling terms, i.e., a change in torsional kinematics was associated with increased muscle activity on one side and decreased activity on the other side. s, whenever torsional terms were retained in a given muscle, they were independent of the inputs we tested, i.e., INC stimulation vs. corrective motion vs. INC inactivation, and left vs. right INC data. These findings suggest that, despite the complexity of the head-neck system, the brain can use a single, bilaterally coupled inverse model for torsional head control that is valid across different behaviors and movement directions. Combined with our previous data, these new data provide the terms for a more complete three-dimensional model of EMG: head rotation coupling for the muscles and gaze behaviors that we recorded.
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Han X, Byrne P, Kahana M, Becker S. When do objects become landmarks? A VR study of the effect of task relevance on spatial memory. PLoS One 2012; 7:e35940. [PMID: 22586455 PMCID: PMC3346813 DOI: 10.1371/journal.pone.0035940] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2012] [Accepted: 03/26/2012] [Indexed: 11/18/2022] Open
Abstract
We investigated how objects come to serve as landmarks in spatial memory, and more specifically how they form part of an allocentric cognitive map. Participants performing a virtual driving task incidentally learned the layout of a virtual town and locations of objects in that town. They were subsequently tested on their spatial and recognition memory for the objects. To assess whether the objects were encoded allocentrically we examined pointing consistency across tested viewpoints. In three experiments, we found that spatial memory for objects at navigationally relevant locations was more consistent across tested viewpoints, particularly when participants had more limited experience of the environment. When participants' attention was focused on the appearance of objects, the navigational relevance effect was eliminated, whereas when their attention was focused on objects' locations, this effect was enhanced, supporting the hypothesis that when objects are processed in the service of navigation, rather than merely being viewed as objects, they engage qualitatively distinct attentional systems and are incorporated into an allocentric spatial representation. The results are consistent with evidence from the neuroimaging literature that when objects are relevant to navigation, they not only engage the ventral "object processing stream", but also the dorsal stream and medial temporal lobe memory system classically associated with allocentric spatial memory.
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Boahene KD, Owusu JA, Collar R, Byrne P, Ishii L. Vascularized Scapular Tip Flap in the Reconstruction of the Mandibular Joint Following Ablative Surgery. ACTA ACUST UNITED AC 2012; 14:211-4. [DOI: 10.1001/archfacial.2012.100] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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Vaughan D, Byrne P. An evaluation of the simultaneous use of the levonorgestrel-releasing intrauterine device (LNG-IUS, Mirena®) combined with endometrial ablation in the management of menorrhagia. J OBSTET GYNAECOL 2012; 32:372-4. [DOI: 10.3109/01443615.2012.666581] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Boahene K, Richmon J, Byrne P, Ishii L. Hinged forearm split-thickness skin graft for radial artery fasciocutaneous flap donor site repair. ACTA ACUST UNITED AC 2012; 13:392-4. [PMID: 22106183 DOI: 10.1001/archfacial.2011.65] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
OBJECTIVE To present a modified technique in the harvest and application of split-thickness skin graft (STSG) from the primary flap donor site in forearm fasciocutaneous free flaps. METHODS A prospective review was performed on 16 consecutive patients who had undergone a radial forearm free flap procedure for reconstruction of head and neck defects with a hinged forearm STSG used to reconstruct the flap donor site defect. RESULTS Sixteen patients with a mean (SD) defect size of 53.7 (29.9) cm(2) underwent the hinged STSG procedure. A hinged STSG was successfully harvested from all patients without disruption. Graft take was greater than 90% in all patients by postoperative day 7. A secondary skin graft donor site was avoided in all but 2 patients. Good color match of the deepithelialized flap with surrounding oral and pharyngeal mucosa was observed. Visible scarring along the graft hinge margin was absent. No bridging scars resulted from the deepithelialized flaps. CONCLUSIONS The hinged STSG from the forearm is a reliable method of repairing radial forearm free flap donor site defects and offers the advantages of reduced suture line scarring, minimal STSG disruption, low or no secondary donor site morbidity, and good color match at the donor and recipient flap sites.
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Dergacheva O, Bateman R, Byrne P, Mendelowitz D. Orexinergic modulation of GABAergic neurotransmission to cardiac vagal neurons in the brain stem nucleus ambiguus changes during development. Neuroscience 2012; 209:12-20. [PMID: 22390944 DOI: 10.1016/j.neuroscience.2012.02.020] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2011] [Revised: 01/26/2012] [Accepted: 02/13/2012] [Indexed: 11/17/2022]
Abstract
Cardiac vagal neurons (CVNs) in the nucleus ambiguus (NA) are the major determinant of parasympathetic activity to the heart. Spontaneous GABAergic neurotransmission to CVNs is modulated by hypothalamic neuropeptide orexin-A in postnatal days 2-5 (P5) rats; however, during early postnatal development, orexin expression changes, and the role of orexin-A in modulating CVN activity at other stages of development is unknown. In this study, we compared changes in GABAergic inhibitory postsynaptic currents (IPSCs) in CVNs evoked by orexin-A in P5, P16-20 (P20), and P27-30 (P30) rats using an in vitro brain stem slice preparation. Bath-applied orexin-A enhanced GABAergic IPSCs in all CVNs tested in P5 and P30 animals and in the majority of neurons tested in P20 pups. Focal application of orexin-A ejected from a pipette positioned within 30 μm of the patched CVN did not alter GABAergic signaling in P5 pups. In contrast, in both P20 and P30 rats, focal application of orexin-A inhibited GABAergic IPSCs, and this inhibition persisted in the presence of tetrodotoxin. These results indicate orexin-A facilitates GABAergic IPSCs likely by activating preceding GABAergic neurons that project to CVNs. Orexin-A also likely acts at GABAergic presynaptic terminals surrounding CVNs within the NA to inhibit GABA release. The latter mechanism is absent in P5 pups but occurs in P20 and P30 rats. In conclusion, this study elucidates an important maturation of the parasympathetic cardiac control system. Alterations in these developmental mechanisms may play a role in pathogenesis of disorders related to a specific stage of development maturation.
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