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Charan RA, Hanson R, Clemens PR. Deubiquitinating enzyme A20 negatively regulates NF-κB signaling in skeletal muscle in mdx mice. FASEB J 2011; 26:587-95. [PMID: 22012122 DOI: 10.1096/fj.11-189829] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Duchenne muscular dystrophy (DMD) is caused by the lack of a functional dystrophin protein that results in muscle fiber membrane disruption and, ultimately, degeneration. Regeneration of muscle fibers fails progressively, and muscle tissue is replaced with connective tissue. As a result, DMD causes progressive limb muscle weakness and cardiac and respiratory failure. The absence of dystrophin from muscle fibers triggers the chronic activation of the nuclear factor of kappa B (NF-κB). Chronic activation of NF-κB in muscle leads to infiltration of macrophages, up-regulation of the ubiquitin-proteosome system, and down-regulation of the helix-loop-helix muscle regulatory factor, MyoD. These processes, triggered by NF-κB activation, promote muscle degeneration and failure of muscle regeneration. A20 (TNFAIP3) is a critical negative regulator of NF-κB. In this study, we characterize the role of A20 in regulating NF-κB activation in skeletal muscle, identifying a novel role in muscle regeneration. A20 is highly expressed in regenerating muscle fibers, and knockdown of A20 impairs muscle differentiation in vitro, which suggests that A20 expression is critically important for regeneration of dystrophic muscle tissue. Furthermore, down-regulation of the classic pathway of NF-κB activation is associated with up-regulation of the alternate pathway in regenerating muscle fibers, suggesting a mechanism by which A20 promotes muscle regeneration. These results demonstrate the important role of A20 in muscle fiber repair and suggest the potential of A20 as a therapeutic target to ameliorate the pathology and clinical symptoms of DMD.
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de Lange G, Ristè D, Dobrovitski VV, Hanson R. Single-spin magnetometry with multipulse sensing sequences. PHYSICAL REVIEW LETTERS 2011; 106:080802. [PMID: 21405560 DOI: 10.1103/physrevlett.106.080802] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2010] [Indexed: 05/30/2023]
Abstract
We experimentally demonstrate single-spin magnetometry with multipulse sensing sequences. The use of multipulse sequences can greatly increase the sensing time per measurement shot, resulting in enhanced ac magnetic field sensitivity. We theoretically derive and experimentally verify the optimal number of sensing cycles, for which the effects of decoherence and increased sensing time are balanced. We perform these experiments for oscillating magnetic fields with fixed phase as well as for fields with random phase. Finally, by varying the phase and frequency of the ac magnetic field, we measure the full frequency-filtering characteristics of different multipulse schemes and discuss their use in magnetometry applications.
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Abi-Samra K, Hanson R, Madou M, Gorkin RA. Infrared controlled waxes for liquid handling and storage on a CD-microfluidic platform. LAB ON A CHIP 2011; 11:723-6. [PMID: 21103528 DOI: 10.1039/c0lc00160k] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
A novel active valving technique, whereby paraffin wax plugs in microchannels on a centrifugal microfluidic platform are actuated using focused infrared (IR) radiation is demonstrated in this report. Microchannels were simultaneously or sequentially opened using a stationary IR source by forming wax plugs with similar or differing melting points. The presented wax plugs offer key advantages over current active valving techniques, including a less involved fabrication procedure, a simpler actuation process, and the ability to multiplex experiment with active valves. In addition, a new technique for automated liquid reagent storage and release on the microfluidic disc platform, based on the formation and removal of a wax layer, is demonstrated. Overall, the techniques presented in this report offer novel methods for liquid handling, separation, and storage on the centrifugal microfluidic disc platform.
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de Lange G, Wang ZH, Riste D, Dobrovitski VV, Hanson R. Universal Dynamical Decoupling of a Single Solid-State Spin from a Spin Bath. Science 2010; 330:60-3. [DOI: 10.1126/science.1192739] [Citation(s) in RCA: 529] [Impact Index Per Article: 37.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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Dobrovitski VV, de Lange G, Ristè D, Hanson R. Bootstrap tomography of the pulses for quantum control. PHYSICAL REVIEW LETTERS 2010; 105:077601. [PMID: 20868076 DOI: 10.1103/physrevlett.105.077601] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2010] [Revised: 07/16/2010] [Indexed: 05/29/2023]
Abstract
Long-time dynamical decoupling and quantum control of qubits require high-precision control pulses. Full characterization (quantum tomography) of imperfect pulses presents a bootstrap problem: tomography requires initial states of a qubit which cannot be prepared without perfect pulses. We present a protocol for pulse error analysis, specifically tailored for a wide range of the single solid-state electron spins. Using a single electron spin of a nitrogen-vacancy center in diamond, we experimentally verify the correctness of the protocol, and demonstrate its usefulness for quantum control tasks.
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Feng W, Wu W, Hua J, Jiang Q, Xuan Y, Hanson R, Hu J. SU-FF-I-131: High Spatial Resolution 1H Magnetic Resonance Spectroscopic Imaging Of Human Breast Cancer At 3T. Med Phys 2009. [DOI: 10.1118/1.3181252] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Dobrovitski VV, Feiguin AE, Hanson R, Awschalom DD. Decay of Rabi oscillations by dipolar-coupled dynamical spin environments. PHYSICAL REVIEW LETTERS 2009; 102:237601. [PMID: 19658973 DOI: 10.1103/physrevlett.102.237601] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2009] [Indexed: 05/28/2023]
Abstract
We study the Rabi oscillations decay of a spin decohered by a spin bath whose internal dynamics is caused by dipolar coupling between the bath spins. The form and rate of decay as a function of the intrabath coupling is obtained analytically, and confirmed numerically. The complex form of decay smoothly varies from power law to exponential, and the rate changes nonmonotonically with the intrabath coupling, decreasing for both slow and fast baths. The form and rate of Rabi oscillations decay can be used to experimentally determine the intrabath coupling strength for a broad class of solid-state systems.
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Serra M, Lim G, Hanson R, Manni MI, Estes J, Kelpec K, Gratton J, Frattini G. Sequence Dependence of Stability for Group II Single Nucleotide Bulge Loops. FASEB J 2009. [DOI: 10.1096/fasebj.23.1_supplement.843.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Fuchs GD, Dobrovitski VV, Hanson R, Batra A, Weis CD, Schenkel T, Awschalom DD. Excited-state spectroscopy using single spin manipulation in diamond. PHYSICAL REVIEW LETTERS 2008; 101:117601. [PMID: 18851332 DOI: 10.1103/physrevlett.101.117601] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2008] [Indexed: 05/26/2023]
Abstract
We use single-spin resonant spectroscopy to study the spin structure in the orbital excited state of a diamond nitrogen-vacancy (N-V) center at room temperature. The data show that the excited-state spin levels have a zero-field splitting that is approximately half of the value of the ground state levels, a g factor similar to the ground state value, and a hyperfine splitting approximately 20x larger than in the ground state. In addition, the width of the resonances reflects the electronic lifetime in the excited state. We also show that the spin level splitting can significantly differ between N-V centers, likely due to the effects of local strain, which provides a pathway to control over the spin Hamiltonian and may be useful for quantum-information processing.
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Hanson R, Dobrovitski VV, Feiguin AE, Gywat O, Awschalom DD. Coherent Dynamics of a Single Spin Interacting with an Adjustable Spin Bath. Science 2008; 320:352-5. [PMID: 18339902 DOI: 10.1126/science.1155400] [Citation(s) in RCA: 326] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Gnuschke JE, Hyland S, Wallace J, Hanson R, Smith S. Still a long way to go for the Lower Mississippi Delta. JOURNAL OF HEALTH AND HUMAN SERVICES ADMINISTRATION 2008; 31:72-104. [PMID: 18575149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
It is difficult to separate the demographic, social, and economic changes that have occurred in the Delta. The complex fabric that forms the Delta cannot be broken into parts for simple analysis. Healthcare issues cannot be separated from economic issues, and neither of these issues can be separated from social, political, and other factors of race and power that form the fabric of the Delta. While this analysis disaggregates the data into separate and distinct sections, the reader should be aware of the complex interactions of the performance measures. The clear interaction of health and economic data cannot be overstated and neither can the relationships between education, productivity, employment, income, and social progress. Health is one aspect of investing in human capital and, like education, has its support in the basic mix of public and private goods. Social goods require social investments, and public safety, education, and health are frequent exceptions to the rules of the marketplace. In many areas of the Delta, the allocation of scarce federal and state financial resources to address the problems of the Delta has served to relieve some of the region's distress. The commitment to long-term intervention has, however, varied widely over time.
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Hanson R, Dodoo DK, Essumang DK, Blay J, Yankson K. The effect of some selected pesticides on the growth and reproduction of fresh water Oreochromis niloticus, Chrysicthys nigrodigitatus and Clarias gariepinus. BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2007; 79:544-547. [PMID: 17943223 DOI: 10.1007/s00128-007-9279-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2007] [Accepted: 09/05/2007] [Indexed: 05/25/2023]
Abstract
Studies were carried out to determine the toxicity of some selected pesticides on fresh water fish in a tropical environment. The uptake of the pesticides lindane, pentachlorophenol (PCP), and propoxur, which are frequently used on farms, and in industries as well as by loggers and timber men on wood were studied in concrete ponds at the University of Cape Coast, in Ghana. The fish used for the study were Oreochromis niloticus, Clarias gariepinus, and Chrysicthys nigrodigitatus. They were obtained from cultured ponds in the Cape Coast and Mankessim districts in the Central Region and Weija Dam, in the Greater Accra region of Ghana. Single high lethal concentration (SD) or acute treatment and cumulative/chronic (or multiple minor) lethal concentration (CD) treatment were employed in administering the pesticides to the fish via water. Gas chromatograph electron capture detector analysis was done on the dead fish to see the extent of ingestion. The LC(50 )values obtained for lindane on the three fish samples were as follows: Chrysicthys - 0.38 mg L(-1); Oreochromis - 0.42 mg L(-1), and Clarias - 1.2 mg L(-1). Mortalities occurred in fish within 3-5 days of application. For the PCP on Chrysicthys, Oreochromis, and Clarias species the LC(50) values were 0.42, 0.32 and 0.64 mg L(-1), respectively, for over a 2- to 3-day period. For a three-time influx period of propoxur the LC(50) for Chrysicthys, Oreochromis, and Clarias, were 22.0, 30.40, and 45.04 (all in mg L(-1)), respectively. The results obtained indicated that the pesticides had adverse effects on the general growth and reproduction of fish as shown by gonadosomatic indices.
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Laing T, Hanson R, Chan F, Bouchier-Hayes D. The role of endothelial dysfunction in the pathogenesis of impaired diabetic wound healing: a novel therapeutic target? Med Hypotheses 2007; 69:1029-31. [PMID: 17502127 DOI: 10.1016/j.mehy.2007.02.040] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2007] [Accepted: 02/22/2007] [Indexed: 11/29/2022]
Abstract
The global burden of diabetes is attributed to its multiple associated complications including impaired wound healing which can ultimately result in amputation. Peripheral vascular disease, infection, neuropathy and abnormal local cellular and cytokine activity are some of the traditionally cited pathological instigators of defective diabetic wound repair. Despite intensive research and subsequent advances in diabetic wound care technology a single treatment with measurable clinical impact has yet to be determined. The phenomenon of endothelial dysfunction as seen in atherosclerosis and recently identified as a characteristic of diabetic vasculature may contribute to impaired cutaneous healing in this group. Indicators of endothelial dysfunction have been demonstrated in diabetic wounds by a number of investigators. Successful results are being obtained with modifiers of endothelial function in the management of cardiovascular disease. We hypothesise that endothelial dysfunction plays a substantial contributory role in the pathogenesis of wound healing impairment of diabetes and holds potential as a target for therapeutic intervention.
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Meunier T, Vink IT, van Beveren LHW, Tielrooij KJ, Hanson R, Koppens FHL, Tranitz HP, Wegscheider W, Kouwenhoven LP, Vandersypen LMK. Experimental signature of phonon-mediated spin relaxation in a two-electron quantum dot. PHYSICAL REVIEW LETTERS 2007; 98:126601. [PMID: 17501146 DOI: 10.1103/physrevlett.98.126601] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2006] [Indexed: 05/15/2023]
Abstract
We observe an experimental signature of the role of phonons in spin relaxation between triplet and singlet states in a two-electron quantum dot. Using both the external magnetic field and the electrostatic confinement potential, we change the singlet-triplet energy splitting from 1.3 meV to zero and observe that the spin relaxation time depends nonmonotonously on the energy splitting. A simple theoretical model is derived to capture the underlying physical mechanism. The present experiment confirms that spin-flip energy is dissipated in the phonon bath.
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Hanson R, Mendoza FM, Epstein RJ, Awschalom DD. Polarization and readout of coupled single spins in diamond. PHYSICAL REVIEW LETTERS 2006; 97:087601. [PMID: 17026336 DOI: 10.1103/physrevlett.97.087601] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2006] [Indexed: 05/12/2023]
Abstract
We study the coupling of a single nitrogen-vacancy center in diamond to a nearby single nitrogen defect at room temperature. The magnetic dipolar coupling leads to a splitting in the electron spin resonance frequency of the nitrogen-vacancy center, allowing readout of the state of a single nitrogen electron spin. At magnetic fields where the spin splitting of the two centers is the same, we observe a strong polarization of the nitrogen electron spin. The amount of polarization can be controlled by the optical excitation power. We combine the polarization and the readout in time-resolved pump-probe measurements to determine the spin relaxation time of a single nitrogen electron spin. Finally, we discuss indications for hyperfine-induced polarization of the nitrogen nuclear spin.
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Koppens FHL, Folk JA, Elzerman JM, Hanson R, van Beveren LHW, Vink IT, Tranitz HP, Wegscheider W, Kouwenhoven LP, Vandersypen LMK. Control and Detection of Singlet-Triplet Mixing in a Random Nuclear Field. Science 2005; 309:1346-50. [PMID: 16037418 DOI: 10.1126/science.1113719] [Citation(s) in RCA: 477] [Impact Index Per Article: 25.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
We observed mixing between two-electron singlet and triplet states in a double quantum dot, caused by interactions with nuclear spins in the host semiconductor. This mixing was suppressed when we applied a small magnetic field or increased the interdot tunnel coupling and thereby the singlet-triplet splitting. Electron transport involving transitions between triplets and singlets in turn polarized the nuclei, resulting in marked bistabilities. We extract from the fluctuating nuclear field a limitation on the time-averaged spin coherence time T2* of 25 nanoseconds. Control of the electron-nuclear interaction will therefore be crucial for the coherent manipulation of individual electron spins.
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Hanson R, van Beveren LHW, Vink IT, Elzerman JM, Naber WJM, Koppens FHL, Kouwenhoven LP, Vandersypen LMK. Single-shot readout of electron spin states in a quantum dot using spin-dependent tunnel rates. PHYSICAL REVIEW LETTERS 2005; 94:196802. [PMID: 16090196 DOI: 10.1103/physrevlett.94.196802] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2004] [Indexed: 05/03/2023]
Abstract
We present a method for reading out the spin state of electrons in a quantum dot that is robust against charge noise and can be used even when the electron temperature exceeds the energy splitting between the states. The spin states are first correlated to different charge states using a spin dependence of the tunnel rates. A subsequent fast measurement of the charge on the dot then reveals the original spin state. We experimentally demonstrate the method by performing readout of the two-electron spin states, achieving a single-shot visibility of more than 80%. We find very long triplet-to-singlet relaxation times (up to several milliseconds), with a strong dependence on the in-plane magnetic field.
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Engel HA, Golovach VN, Loss D, Vandersypen LMK, Elzerman JM, Hanson R, Kouwenhoven LP. Measurement efficiency and n-shot readout of spin qubits. PHYSICAL REVIEW LETTERS 2004; 93:106804. [PMID: 15447437 DOI: 10.1103/physrevlett.93.106804] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2003] [Indexed: 05/24/2023]
Abstract
We consider electron spin qubits in quantum dots and define a measurement efficiency e to characterize reliable measurements via n-shot readouts. We propose various implementations based on a double dot and a quantum point contact (QPC) and show that the associated efficiencies e vary between 50% and 100%, allowing single-shot readout in the latter case. We model the readout microscopically and derive its time dynamics in terms of a generalized master equation, calculate the QPC current, and show that it allows spin readout under realistic conditions.
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Elzerman JM, Hanson R, Willems Van Beveren LH, Witkamp B, Vandersypen LMK, Kouwenhoven LP. Single-shot read-out of an individual electron spin in a quantum dot. Nature 2004; 430:431-5. [PMID: 15269762 DOI: 10.1038/nature02693] [Citation(s) in RCA: 353] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2004] [Accepted: 05/25/2004] [Indexed: 11/09/2022]
Abstract
Spin is a fundamental property of all elementary particles. Classically it can be viewed as a tiny magnetic moment, but a measurement of an electron spin along the direction of an external magnetic field can have only two outcomes: parallel or anti-parallel to the field. This discreteness reflects the quantum mechanical nature of spin. Ensembles of many spins have found diverse applications ranging from magnetic resonance imaging to magneto-electronic devices, while individual spins are considered as carriers for quantum information. Read-out of single spin states has been achieved using optical techniques, and is within reach of magnetic resonance force microscopy. However, electrical read-out of single spins has so far remained elusive. Here we demonstrate electrical single-shot measurement of the state of an individual electron spin in a semiconductor quantum dot. We use spin-to-charge conversion of a single electron confined in the dot, and detect the single-electron charge using a quantum point contact; the spin measurement visibility is approximately 65%. Furthermore, we observe very long single-spin energy relaxation times (up to approximately 0.85 ms at a magnetic field of 8 T), which are encouraging for the use of electron spins as carriers of quantum information.
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Hanson R, Witkamp B, Vandersypen LMK, van Beveren LHW, Elzerman JM, Kouwenhoven LP. Zeeman energy and spin relaxation in a one-electron quantum dot. PHYSICAL REVIEW LETTERS 2003; 91:196802. [PMID: 14611599 DOI: 10.1103/physrevlett.91.196802] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2003] [Indexed: 05/24/2023]
Abstract
We have measured the relaxation time, T1, of the spin of a single electron confined in a semiconductor quantum dot (a proposed quantum bit). In a magnetic field, applied parallel to the two-dimensional electron gas in which the quantum dot is defined, Zeeman splitting of the orbital states is directly observed by measurements of electron transport through the dot. By applying short voltage pulses, we can populate the excited spin state with one electron and monitor relaxation of the spin. We find a lower bound on T1 of 50 micros at 7.5 T, only limited by our signal-to-noise ratio. A continuous measurement of the charge on the dot has no observable effect on the spin relaxation.
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Vozarova B, Stefan N, Hanson R, Lindsay RS, Bogardus C, Tataranni PA, Metz C, Bucala R. Plasma concentrations of macrophage migration inhibitory factor are elevated in Pima Indians compared to Caucasians and are associated with insulin resistance. Diabetologia 2002; 45:1739-41. [PMID: 12552367 DOI: 10.1007/s00125-002-0896-4] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2002] [Accepted: 05/20/2002] [Indexed: 11/24/2022]
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72
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De Franceschi S, Hanson R, Van Der Wiel WG, Elzerman JM, Wijpkema JJ, Fujisawa T, Tarucha S, Kouwenhoven LP. Out-of-equilibrium Kondo effect in a mesoscopic device. PHYSICAL REVIEW LETTERS 2002; 89:156801. [PMID: 12366010 DOI: 10.1103/physrevlett.89.156801] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2002] [Indexed: 05/23/2023]
Abstract
We study the nonequilibrium regime of the Kondo effect in a quantum dot laterally coupled to a narrow wire. We observe a split Kondo resonance when a finite bias voltage is imposed across the wire. The splitting is attributed to the creation of a double-step Fermi distribution function in the wire. Kondo correlations are strongly suppressed when the voltage across the wire exceeds the Kondo temperature. A perpendicular magnetic field enables us to selectively control the coupling between the dot and the two Fermi seas in the wire. Already at fields of order 0.1 T only the Kondo resonance associated with the strongly coupled reservoir survives.
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Graham S, Das GK, Hidvegi RJ, Hanson R, Kosiuk J, Al ZK, Menzies D. Chest radiograph abnormalities associated with tuberculosis: reproducibility and yield of active cases. Int J Tuberc Lung Dis 2002; 6:137-42. [PMID: 11931412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/24/2023] Open
Abstract
SETTING Tertiary care referral centre specialising in respiratory diseases. OBJECTIVES Chest radiography is a major screening and diagnostic tool for tuberculosis (TB). We evaluated the reproducibility of a radiographic classification system for screening for active TB of immigration applicants to Canada. We also evaluated the validity of this classification system for detection of prevalent active TB among the screened applicants, as well as tuberculin-positive close contacts and symptomatic patients. METHODS Reproducibility was assessed by re-reading a randomly selected 10% sample of screening chest films. Validity was estimated from the final clinical and microbiologic diagnosis of patients undergoing detailed clinical evaluation. RESULTS Inter-reader agreement using five broad categories was moderate (kappas of 0.44-0.56), while intra-reader agreement was substantial (kappas of 0.59-0.72). After adjustment for age and patient group, the adjusted odds of active tuberculosis, relative to normal or minor findings or granulomas, for fibronodular changes was 10.2 (95% confidence interval [CI] 3.2-33), for mass or pleural effusion it was 11.6 (95%CI 3.6-37), and for parenchymal infiltrate it was 46.1 (95%CI 18-117). Among tuberculin-positive close contacts, the probability of active tuberculosis was more than 50% if the radiographs showed any mass, pleural disease, or parenchymal infiltrates. CONCLUSION A simple classification of TB-related chest radiographic abnormalities into five broad categories had moderate to substantial reproducibility of readings, with reasonable validity.
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Bridges J, Hanson R, Little M, Flannigan AC, Fairley M, Haywood L. Ethical relationships in paediatric emergency medicine: moving beyond the dyad. EMERGENCY MEDICINE (FREMANTLE, W.A.) 2001; 13:344-50. [PMID: 11554867 DOI: 10.1046/j.1035-6851.2001.00238.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Most areas of health-services research concentrate on a dyadic relationship between doctor and patient. In paediatric emergency medicine it may be necessary to focus on a more complicated relationship because the parents of the child play an important role in the delivery of medical services. This paper discusses the ethical principles in paediatric emergency medicine from the perspective of five disciplines: health economics, paediatrics, medical ethics, law and mental health. The general consensus is that the traditional dyadic model is inadequate and that a more complicated relationship is needed for the paediatric emergency setting, such as triadic, multiple-dyadic or polyadic. Such models allow the inclusion of the parents and possibly other family members, medical providers and community members. If the paediatric setting is considered in such a framework, it may be possible to deliver a more socially beneficial medical service.
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Briere J, Johnson K, Bissada A, Damon L, Crouch J, Gil E, Hanson R, Ernst V. The Trauma Symptom Checklist for Young Children (TSCYC): reliability and association with abuse exposure in a multi-site study. CHILD ABUSE & NEGLECT 2001; 25:1001-1014. [PMID: 11601594 DOI: 10.1016/s0145-2134(01)00253-8] [Citation(s) in RCA: 118] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
OBJECTIVE The Trauma Symptom Checklist for Young Children (TSCYC) is a 90-item caretaker-report measure of children's trauma- and abuse-related symptomatology. It contains two reporter validity scales and eight clinical scales [Post-traumatic Stress-Intrusion (PTS-I), Post-traumatic Stress-Avoidance (PTS-AV), Post-traumatic Stress-Arousal (PTS-AR), Post-traumatic Stress-Total (PTS-TOT), Sexual Concerns (SC), Dissociation (DIS), Anxiety (ANX), Depression (DEP), and Anger/Aggression (ANG)], as well as an item assessing hours per week of caretaker contact with the child. This paper introduces the TSCYC and describes its psychometric properties in a multisite validity study. METHOD A total of 219 TSCYCs administered by six clinician/researchers across the United States were analyzed for scale reliability and association with several types of childhood maltreatment. RESULTS The TSCYC clinical scales have good reliability and are associated with exposure to childhood sexual abuse, physical abuse, and witnessing domestic violence. The PTS-I, PTS-AV, PTS-AR, and PTS-TOT scales were most predictive, followed by SC in the case of sexual abuse and DIS in the case of physical abuse. There were a small number of age, sex, and race effects on TSCYC scores. CONCLUSIONS The TSCYC appears to have reasonable psychometric characteristics, and correlates as expected with various types of trauma exposure. Subject to continued validation and the development of general population norms, its use as a clinical measure is supported.
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76
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Wilkinson R, Hanson R. Ear tip necrosis in standard poodles. Vet Rec 2001; 149:32. [PMID: 11486780] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
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77
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Caplan R, Guthrie D, Komo S, Shields WD, Chayasirisobhon S, Kornblum HI, Mitchell W, Hanson R. Conversational repair in pediatric epilepsy. BRAIN AND LANGUAGE 2001; 78:82-93. [PMID: 11412017 DOI: 10.1006/brln.2000.2447] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
This study examined if children with complex partial seizures disorder (CPS) and primary generalized epilepsy with absence (PGE) were impaired in the use of self-initiated repair during a conversation compared to normal children. Transcriptions of speech samples of 92 CPS, 51 PGE, and 65 normal children, ages 5-16 years, were coded for self-initiated repair according to Evans (1985). The WISC-R, a structured psychiatric interview, and seizure-related information were obtained for each child. We found impaired use of repair in both the CPS and PGE groups compared to the normal subjects. The CPS patients, particularly those with a temporal lobe focus, overused self-initiated corrections of referents and syntax compared to the PGE and normal subjects. The CPS and PGE patients with frontal lobe involvement underused fillers compared to the normal children. These findings provide additional evidence that both CPS and PGE impact the ongoing development of children's communication skills.
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Anderson R, Archer D, Bathmann U, Boyd P, Buesseler K, Burkill P, Bychkov A, Carlson C, Chen CT, Doney S, Ducklow H, Emerson S, Feely R, Feldman G, Garçon V, Hansell D, Hanson R, Harrison P, Honjo S, Jeandel C, Karl D, Le Borgne R, Liu K, Lochte K, Louanchi F, Lowry R, Michaels A, Monfray P, Murray J, Oschlies A, Platt T, Priddle J, Quiñones R, Ruiz-Pino D, Saino T, Sakshaug E, Shimmield G, Smith S, Smith W, Takahashi T, Tréguer P, Wallace D, Wanninkhof R, Watson A, Willebrand J, Wong CS. A new vision of ocean biogeochemistry after a decade of the Joint Global Ocean Flux Study (JGOFS). AMBIO 2001:4-30. [PMID: 11842646] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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79
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Patel CK, Hanson R, McDonald B, Cox N. Case reports and small case series: late dislocation of a LASIK flap caused by a fingernail. ARCHIVES OF OPHTHALMOLOGY (CHICAGO, ILL. : 1960) 2001; 119:447-9. [PMID: 11231782] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
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80
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Jenkinson CP, Hanson R, Cray K, Wiedrich C, Knowler WC, Bogardus C, Baier L. Association of dopamine D2 receptor polymorphisms Ser311Cys and TaqIA with obesity or type 2 diabetes mellitus in Pima Indians. Int J Obes (Lond) 2000; 24:1233-8. [PMID: 11093282 DOI: 10.1038/sj.ijo.0801381] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
OBJECTIVES To investigate whether (a) variants within the dopamine D2 receptor gene (DRD2) are associated with obesity and type 2 diabetes in Pima Indians, and (b) whether variation in this gene could be responsible for previously observed linkage to these phenotypes, at chromosome location 11q23-24, in this population. DESIGN Two single nucleotide polymorphisms (SNPs), Ser311Cys and TaqIA, within the DRD2 gene were genotyped by allelic discrimination PCR in subjects who had provided evidence of linkage to diabetes and obesity in an autosome-wide scan. SUBJECTS A total of 1,187 subjects were genotyped, including 947 full heritage Pima Indians (80%). Descriptive statistics for all subjects analyzed, for whom clinical data were available, were (mean+/-s.d.): age at time of last exam = 41 +/- 15 y; birth year=1950 +/- 14; age-sex-adjusted body mass index (BMI; adjusted to a mean age of 35y)=36 +/- 8kg/m2; male = 44%; diabetic = 57%. For full heritage Pimas only: age = 43 +/- 15 y; birth year = 1948 +/- 14; sex- age-adjusted BMI = 36 +/- 8 kg/m2; male = 43%; diabetic = 59%. RESULTS Neither polymorphism was significantly associated with diabetes in full heritage Pimas. Individuals with a 'CG' genotype at the Ser311Cys SNP had a higher BMI than those with a 'CC' genotype (36.7 vs 35.5 kg/m2, P= 0.04). Linkage analysis of BMI, adjusted for either polymorphism, resulted in LOD scores that were similar to those obtained without adjustment. CONCLUSION Heterozygotes at the Ser311Cys DRD2 polymorphism had a slightly higher BMI than homozygotes, however neither the Ser311Cys nor the TaqIA polymorphism accounted for the linkage with BMI on chromosome 11 in Pima Indians.
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81
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Woolfenden S, Ritchie J, Hanson R, Nossar V. Parental use of a paediatric emergency department as an ambulatory care service. Aust N Z J Public Health 2000; 24:204-6. [PMID: 10790943 DOI: 10.1111/j.1467-842x.2000.tb00144.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
OBJECTIVE This qualitative study explored the parental attitudes, perceptions and beliefs that play a role in the use of a tertiary paediatric emergency department (PED) when a child has a non-urgent illness. METHOD Semi-structured, in-depth interviews of 25 parents of children with non-urgent illnesses were conducted in the waiting room of a tertiary PED in Western Sydney in 1998. Inductive analysis was used to identify dominant themes. RESULTS Parents used their own system of triage to choose the appropriate service for their sick child. The perceived expertise of the tertiary PED, access and parental expectations all appeared to be major factors in parental use of a PED. CONCLUSIONS The parental choice to attend a PED is a dynamic, complex and unique process and the parental views that underpin this process often diverge from those of health professionals about the most 'appropriate' use of a PED. IMPLICATIONS A clearer understanding by health professionals of the factors influencing parental choice will promote more effective collaboration with parents and ultimately assist in the decision on the best management option for sick children.
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82
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Nessim GT, Ofori-Kumba FK, Hanson R, Velusamy S. Early diagnosis of traumatic rupture of the right hemidiaphragm. Ann R Coll Surg Engl 2000; 82:101-2. [PMID: 10743426 PMCID: PMC2503523] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023] Open
Abstract
A case of traumatic rupture of the right hemidiaphragm, which was diagnosed early on the basis of clinical and radiographic suspicions, is discussed.
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83
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Chey T, Jalaludin B, Hanson R, Leeder S. Validation of a predictive model for asthma admission in children: how accurate is it for predicting admissions? J Clin Epidemiol 1999; 52:1157-63. [PMID: 10580778 DOI: 10.1016/s0895-4356(99)00111-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
We studied 364 index presentations to the Emergency Department of a children's hospital with a diagnosis of asthma. The admission rate for this group of children was about 31%. We developed a parsimonious multiple logistic regression model to predict asthma hospital admission based on asthma severity indicators. We then evaluated the model's predictive ability using two methods of cross-validation, using the same sample that was used for the predictive model, and using data from a split sample. The logistic regression model had a predictive accuracy of 90% (95% confidence interval 85-95%). The sensitivity and specificity were 86% and 88%, respectively. Cross-validation models confirmed that the predictive ability of the model was stable. In studies with limited sample sizes, it is possible to validate a model without setting aside a split sample for cross-validation.
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84
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Malyankar UM, Hanson R, Schwartz SM, Ridall AL, Giachelli CM. Upstream stimulatory factor 1 regulates osteopontin expression in smooth muscle cells. Exp Cell Res 1999; 250:535-47. [PMID: 10413606 DOI: 10.1006/excr.1999.4537] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Vascular smooth muscle cells (SMCs) undergo a dramatic phenotypic transition in response to injury and ex vivo culture that includes enhanced proliferation, migration, matrix deposition, and alterations in gene expression. Osteopontin is a good marker for the injury-induced SMC phenotypic state in vivo and in vitro. To identify transcription factors that might control the regulation of osteopontin expression, we investigated cultured vascular SMCs that express high and low levels of osteopontin. Using nuclear run-on assays, mRNA stability studies, and deletion analysis, we demonstrate that regulation of osteopontin steady-state mRNA levels in SMCs occurs at the transcriptional level. Transient transfection and gel-shift analyses of osteopontin promoter indicated that a region between -123 and +66 was involved in the expression of osteopontin. Supershift EMSAs identified the bHLH-leucine zipper transcription factor upstream stimulatory factor-1 (USF1) as the protein binding to this sequence. Finally, we show that USF1 protein is induced in vivo within 24 h of balloon angioplasty of rat carotids coordinately with osteopontin induction. These data suggest that USF1 governs expression of osteopontin in cultured vascular SMCs and might contribute to initial osteopontin expression observed post carotid injury and in vascular pathologies in vivo.
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MESH Headings
- Aging
- Angioplasty, Balloon
- Animals
- Animals, Newborn
- Base Sequence
- Carotid Arteries/metabolism
- Carotid Artery Injuries
- Cells, Cultured
- Consensus Sequence/genetics
- DNA-Binding Proteins/metabolism
- Gene Expression Regulation
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/metabolism
- Mutation
- Oligonucleotides/genetics
- Oligonucleotides/metabolism
- Osteopontin
- Promoter Regions, Genetic/genetics
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Rats
- Response Elements/genetics
- Sialoglycoproteins/genetics
- Transcription Factors/metabolism
- Transcription, Genetic/genetics
- Transfection
- Upstream Stimulatory Factors
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85
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Hanson R, Zhao XP, Islam-Faridi MN, Paterson A, Zwick M, Crane C, McKnight T, Stelly D, Price HJ. Evolution of interspersed repetitive elements inGossypium (Malvaceae). AMERICAN JOURNAL OF BOTANY 1998; 85:1364-1368. [PMID: 21684890] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Very little is known regarding how repetitive elements evolve inpolyploid organisms. Here we address this subject by fluorescent insitu hybridization (FISH) of 20 interspersed repetitive elements tometaphase chromosomes of the cotton AD-genome tetraploid Gossypiumhirsutum and its putative A- and D-genome diploid ancestors. Theseelements collectively represent an estimated 18% of the G.hirsutum genome, and constitute the majority of high-copyinterspersed repetitive elements in G. hirsutum. Seventeen ofthe elements yielded FISH signals on chromosomes of both G.hirsutum subgenomes, while three were A-subgenome specific. Hybridization of eight selected elements, two of which were A-subgenomespecific, to the A(2) genome of G. arboreum yielded asignal distribution that was similar to that of the G. hirsutumA-subgenome. However, when hybridized to the D(5) genome ofG. raimondii, the putative diploid ancestor of the G.hirsutum D-subgenome, none of the probes, including elements thatstrongly hybridized to both G. hirsutum subgenomes, yieldeddetectable signal. The results suggest that the majority, although notall, G. hirsutum interspersed repetitive elements haveundergone intergenomic concerted evolution following polyploidizationand that this has involved colonization of the D-subgenome byA-subgenome elements and/or replacement of D-subgenome elements byelements of the A-subgenometype.
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86
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Kabir A, Hanson R, Mellis CM, van Asperen PP. Is asthma documentation improved by computer-facilitated data entry? JOURNAL OF QUALITY IN CLINICAL PRACTICE 1998; 18:187-93. [PMID: 9744657] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The documentation of acute asthma in written medical records was compared with data entered into a Computer-Assisted Triage System (CATS) in 104 children who presented to the emergency department and subsequently admitted to the Royal Alexandra Hospital for Children, Sydney. A total of 65 items in 5 categories were analysed and satisfactory documentation was defined as the recording of a specific item in more than 80% of records (written or electronic). Satisfactory documentation was observed for all 6 items in visit details and 9 out of 10 items in triage details for both recording systems. Nursing observations were better documented in the medical record than in CATS (87 vs 25%; kappa = 0.63). Documentation of medical details was also worse in CATS (75 vs 25%; kappa = 0.24) and the documentation of asthma severity was poor in both systems (31 vs 0%; kappa = 0.31). Attempts to improve asthma documentation through the development of a computerized medical record have highlighted further barriers to documentation.
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87
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Prasad A, Hanson R. 10 questions about Lyme neuroborreliosis. COMPREHENSIVE THERAPY 1998; 24:415-20. [PMID: 9784947] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
The diagnosis of Lyme neuroborreliosis requires a high index of suspicion and chronological correlation of the clinical findings and laboratory data. The limitations of serologic tests must be understood. Cerebrospinal fluid anti-Borrelia burgdorferi antibody index is currently the best indicator of Lyme neuroborreliosis.
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88
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Hirsch R, Lethbridge-Cejku M, Hanson R, Scott WW, Reichle R, Plato CC, Tobin JD, Hochberg MC. Familial aggregation of osteoarthritis: data from the Baltimore Longitudinal Study on Aging. ARTHRITIS AND RHEUMATISM 1998; 41:1227-32. [PMID: 9663480 DOI: 10.1002/1529-0131(199807)41:7<1227::aid-art13>3.0.co;2-n] [Citation(s) in RCA: 93] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
OBJECTIVE To evaluate the familial aggregation of osteoarthritis (OA) in a cohort of healthy volunteers drawn from a community setting. METHODS Hand radiographs obtained between 1978 and 1991 and bilateral standing knee radiographs obtained between 1984 and 1991 were read for changes of OA, using Kellgren-Lawrence (K-L) scales. The hand sites were distal interphalangeal (DIP) joints, proximal interphalangeal (PIP) joints, and first carpometacarpal (CMC1) joints. For each joint group, the presence of OA in at least 1 joint in a joint group, the number of affected digits in each joint group, and the sum of the K-L grade across all joints were analyzed. Polyarticular OA was recorded if there were OA findings in 2 of 3 hand joint groups plus 1 or both knees. Data from 167 families with hand radiographs, 157 families with knee radiographs, and 148 families with both hand and knee radiographs were analyzed for sib-sib correlations. RESULTS After adjustment for age, sex, and body mass index, clinically relevant sib-sib common correlations were found for OA of the DIP, PIP, and CMC1 joints, for OA at 2 or 3 hand sites, and for polyarticular OA (r = 0.33-0.81) when OA was defined according to the number of affected joints or as the sum of the K-L grade across all joints. CONCLUSION These results from a cohort of volunteers drawn from a community setting and ascertained without regard to OA status demonstrate familial aggregation of OA and contribute to the evidence for heritability of OA.
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Abstract
Casemix funding for hospitals with the use of diagnosis-related groups (DRGs), which organise patients' conditions into similar clinical categories with similar costs, was introduced in Australia five years ago. It has been applied in different ways and to a greater or lesser extent in different Australian States. Only Victoria and South Australia have implemented casemix funding across all healthcare services. Attempts have been made to formally evaluate its impact, but they have not met the required scientific standards in controlling for confounding factors. Casemix funding remains a much-discussed issue. In this Debate, Braithwaite and Hindle take a contrary position, largely to stimulate policy debate; Phelan defends the casemix concept and advocates retaining its best features; and Hanson adds a plea for consumer input.
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90
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Quattrocki E, Baird A, Hanson R, Renshaw P, Cohen B, Yurgelun-Todd D. Effects of Smoking on Frontal Activation: An fMRI Study. Neuroimage 1998. [DOI: 10.1016/s1053-8119(18)30944-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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91
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Jalaludin B, Chey T, Holmwood M, Chipps J, Hanson R, Corbett S, Leeder S. Admission rates as an indicator of the prevalence of severe asthma in the community. Aust N Z J Public Health 1998; 22:214-9. [PMID: 9744179 DOI: 10.1111/j.1467-842x.1998.tb01175.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND A reliable indicator of the prevalence of severe asthma in the community is needed to monitor population-based asthma control strategies. We examined the potential use of asthma admissions to hospital as such an indicator. METHODS We recruited subjects from the Emergency Department (ED) of a children's hospital. The attending doctor completed the 'physician questionnaire' which included questions on the patient's asthma severity and interval severity/chronicity of asthma. The parent/guardian completed the 'parent questionnaire'. It included questions on demography, asthma knowledge and attitudes, asthma history and social support. We performed univariate and multiple logistic regression to determine predictors for hospital admission. RESULTS Interval severity of asthma, pre-treatment severity of wheeze and low post-treatment pulse oximetry best predicted whether children presenting with asthma were admitted. Demographic variables, factors associated with access to health services and factors related to the asthma history and management were not significant predictors of admission. DISCUSSION At the population level, it may be possible to utilise routine hospital admission rates as an indicator of the prevalence of severe asthma in the community, especially within the context of monitoring trends in asthma prevalence. Our study was conducted in a metropolitan tertiary paediatric hospital. The reliability of hospital admission rates as indicators of the prevalence of severe asthma in other hospital settings, in different population groups and over time remains to be established.
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92
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Cornforth DP, Rabovitser JK, Ahuja S, Wagner JC, Hanson R, Cummings B, Chudnovsky Y. Carbon Monoxide, Nitric Oxide, and Nitrogen Dioxide Levels in Gas Ovens Related to Surface Pinking of Cooked Beef and Turkey. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 1998; 46:255-261. [PMID: 10554228 DOI: 10.1021/jf970475i] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Carbon monoxide (CO) and total nitrogen oxide (NO(x)()) levels were monitored during meat cookery with a standard Ovenpak and a new ultralow-NO(x)() (ULN) cyclonic gas burner. With the standard burner, CO varied from 103 to 152 ppm, NO(x)() was 1.3-10.7 ppm, and surface pinking was observed on both beef and turkey. The ULN burner at optimal efficiency produced only 6.7 ppm of CO and 1 ppm of NO(x)(), insufficient to cause surface pinking. To determine the relative contribution of CO and NO(x)() to pinking, trials were also conducted in an electric oven with various pure gases. Pinking was not observed with up to 149 ppm of CO or 5 ppm of NO. However, as little as 0.4 ppm of nitrogen dioxide (NO(2)) caused pinking of turkey rolls. Beef roasts were pink at >2.5 ppm of NO(2). Thus, pinking previously attributed to CO and NO in gas ovens is instead due to NO(2), which has much greater reactivity than NO with moisture at meat surfaces.
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93
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94
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Hess JL, Yu BD, Li B, Hanson R, Korsmeyer SJ. Defects in yolk sac hematopoiesis in Mll-null embryos. Blood 1997; 90:1799-806. [PMID: 9292512] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Translocations involving the mixed lineage leukemia gene (MLL), the human homolog of the Drosophila gene trithorax, are one of the most common genetic alterations in human acute leukemias. Each translocation involving MLL results in loss of one functional copy of MLL and the generation of a chimeric fusion protein with potential dominant negative or neomorphic activity. Mll is a positive regulator of Hox genes, which have been implicated in both axial skeleton patterning and hematopoietic development. Previous studies indicated that Hox gene expression is altered in Mll heterozygous (+/-) and homozygous (-/-) deficient mice. To study the role of Mll in hematopoiesis and to obtain insights into leukemogenesis, we have examined the effects of haplo-insufficiency or absence of Mll by in vitro differentiation of Mll +/+, +/-, and -/- yolk sac progenitor cells. Mll -/- colonies were fewer in number, took longer to develop, and contained fewer cells than their wild-type and heterozygous counterparts. Formation of colony-forming unit-granulocyte, erythroid, macrophage, megakaryocyte (CFU-GEMM), colony-forming unit-macrophage (CFU-M), and burst-forming unit-erythroid (BFU-E) was markedly decreased in Mll -/- cultures, while numbers of colony-forming unit-erythroid (CFU-E), colony-forming unit-granulocyte (CFU-G), and colony-forming unit-granulocyte macrophage (CFU-GM) were essentially unaffected. Despite the decreased numbers of colonies present, Mll -/- cultures showed all cell types without morphologic evidence of maturation arrest. These studies indicate that Mll is required for normal numbers of hematopoietic progenitors and their proper differentiation, especially along the myeloid and macrophage pathways.
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Hanson R. Sore points sorted. NURSING TIMES 1997; 93:66-72. [PMID: 9095955] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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96
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Hanson R, Browne G, Fasher B, Mcaskill M, Moroney P, Hawker R. Cisapride-induced prolonged QT interval: too much of a good thing! J Pediatr 1997; 130:164-6. [PMID: 9003873 DOI: 10.1016/s0022-3476(97)70337-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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97
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Veille JC, Hanson R, Steele L, Tatum K. M-mode echocardiographic evaluation of fetal and infant hearts: longitudinal follow-up study from intrauterine life to year one. Am J Obstet Gynecol 1996; 175:922-8. [PMID: 8885749 DOI: 10.1016/s0002-9378(96)80026-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
OBJECTIVE Our purpose was to evaluate cardiac variables, including right and left end-diastolic and end-systolic dimensions by use of M-mode echocardiography during fetal, neonatal (transitional), and infancy periods to understand hemodynamic adaptation during these periods. STUDY DESIGN Fifty-three fetuses were enrolled in this study. Echocardiography evaluations were started as early as the sixteenth week of gestation and were repeated every 4 to 6 weeks until term, on postnatal days 1 and 2, and at 6 weeks, 6 months, and 12 months of age. End-diastolic and end-systolic measurements were made according to published standards. Mean and SEM for each of the end-diastolic and end-systolic measurements were calculated for each of 11 study periods. Data were analyzed by one-way analysis of variance, corrected for repeated measures, and in the case of right and left ventricular differences paired t tests were used for significance. RESULTS Left ventricular end-diastolic and end-systolic correlated positively with advancing age (R2 = 0.93, p < 0.0001), right ventricular end-diastolic also correlated with advancing age (R2 = = 0.361, p < 0.05), and right ventricular end-diastolic was significantly larger than left ventricular end-diastolic in utero (p < 0.01), whereas the opposite was true after birth (p < 0.0001). Heart rate significantly decreased with advancing age (p < 0.001), whereas ejection fraction for either the right or the left ventricle did not change significantly with advancing age. CONCLUSION This suggests that under basal conditions the ventricles can meet the increased demands in cardiac output by increasing ventricular dimensions without having to increase contractility reserve.
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Bakshi N, Lawson J, Hanson R, Ames C, Vinters HV. Fatal mumps meningoencephalitis in a child with severe combined immunodeficiency after bone marrow transplantation. J Child Neurol 1996; 11:159-62. [PMID: 8881994 DOI: 10.1177/088307389601100218] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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99
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Burgess MA, Levy M, Alperstein G, Mira M, Bek M, Isaacs D, Kakakios A, Fasher B, Hanson R, Kilham H, Malcolm M. "On the spot' vaccination: does it work? J Paediatr Child Health 1996; 32:63-7. [PMID: 8652218 DOI: 10.1111/j.1440-1754.1996.tb01545.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
OBJECTIVE To trial and evaluate a system of "on the spot' vaccination for children up to the age of 15 years in the Early Childhood Centres of the Central Sydney Area Health Service, at the Royal Alexandra Hospital for Children and in a number of general practices in the area. METHODOLOGY A brief questionnaire was used to collect data from parents and health care professionals about the child's vaccination status and vaccines given "on the spot'. RESULTS Over an 8 week period in August-September 1993, 5162 questionnaires were completed; 71% of children were up to date with their vaccination. If Haemophilus influenzae type b vaccine, which had been introduced only 2 months before commencement of the study, was excluded, 84% of the children were up to date. A total of 441 children were given 663 vaccinations "on the spot'. Very few children were too ill to be vaccinated (6%). However, only 30% of those who needed vaccination "on the spot' actually received it (441 of 1480), and only 41% (24 of 58) of a subset of those who were not vaccinated were known to have complied 1 month later. Children attending Early Childhood Centres were younger than children attending general practices or the hospital. CONCLUSIONS A high proportion of children who attended for routine or acute health care had vaccinations overdue (30%). If this scheme could be continued and expanded it would have an important impact on vaccination coverage, and hence on the incidence of vaccine-preventable diseases.
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100
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DeSombre ER, Hughes A, Landel CC, Greene G, Hanson R, Schwartz JL. Cellular and subcellular studies of the radiation effects of Auger electron-emitting estrogens. Acta Oncol 1996; 35:833-40. [PMID: 9004760 DOI: 10.3109/02841869609104034] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
We studied the effect of 123I-labeled estrogen (123I-E) in estrogen receptor (ER)-rich cells in culture and in cell free model systems in vitro to elucidate the nature of the radiotoxicity for ER + cells of estrogens containing nuclides which emit Auger electrons. In cells the 123I-E caused a dose-dependent, unlabeled estrogen-inhibitable induction of chromosome aberrations. A dose of about 1000 decays per cell, which is approximately the mean lethal dose for these cells, resulted in an average of 1 chromosome break per cell. This supports the hypothesis that the lethal lesion induced by 123I-E is a chromosome break. Incubation of 123I-E/ER complex, but not 123I-E alone, with 27-mer duplex estrogen response element (ERE) DNA produced a dose-dependent cleavage of the ERE. However, we were unable to detect any fragmentation of either the 66 kDa full length ER in cell extracts or a purified 31 kDa hormone binding domain when incubated with excess 123I-E. Thus it appears that 123I-E effects its radiotoxicity by binding to ER, associating with ERE DNA and, by directing high LET radiation to DNA, inducing lethal chromosome breaks.
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