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Maurizo A, Jang S, Watchman C, Hamilton R. SU-FF-T-127: Perhipheral Dose of Tungsten Powder Compensator (WPC) Based IMRT. Med Phys 2009. [DOI: 10.1118/1.3181601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Krafft S, Jang S, Hamilton R, Watchman C. SU-FF-T-139: Dosimetric Accuracy of Low Dose Region (V5-V10) in TomoTherapy Planning of Lung IMRT. Med Phys 2009. [DOI: 10.1118/1.3181613] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Miedema B, Hamilton R, Fortin P, Easley J, Tatemichi S. The challenges and rewards of rural family practice in New Brunswick, Canada: lessons for retention. Rural Remote Health 2009. [DOI: 10.22605/rrh1141] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
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Miedema B, Hamilton R, Fortin P, Easley J, Tatemichi S. The challenges and rewards of rural family practice in New Brunswick, Canada: lessons for retention. Rural Remote Health 2009; 9:1141. [PMID: 19496642] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023] Open
Abstract
INTRODUCTION This study examined the work environment of rural family physicians in New Brunswick, a province in eastern Canada. The purpose of the research was to explore the job satisfaction of rural family physicians based on gender, age, years in practice, and language and location of practice. METHODS We used a qualitative, collective case study approach (24 cases of two individuals each: 48 interviews). Cases were selected based on gender, location (urban/rural), language (French/English) and number of years since medical school graduation (<10 years, 10-20 years, >20 years). The data reported is based on 21 interviews with rural physicians. Participants were recruited using the College of Physicians and Surgeons of New Brunswick website information. The research team traveled to physicians' offices throughout the province of New Brunswick to conduct interviews in the language of preference of the physician (French or English). Male researchers interviewed male participants and female researchers interviewed female participants. Interviews were transcribed verbatim and analyzed for themes related to the benefits and challenges of rural practice. Consensus on themes was reached among the entire research team. RESULTS Many rural practitioners face a host of challenges ranging from professional isolation, complex patient profiles and maintaining professional boundaries. In this study, the most important challenge rural family physicians faced was the non-clinical issue of boundary maintenance. When rural family physicians had difficulties maintaining boundaries they were more likely to consider leaving their rural practice. Overall, few differences, based on gender, age, years in practice and language of practice were found. A few rural family physicians felt that the benefits of rural practice outweighed the challenges. CONCLUSIONS This study demonstrates that rural family physicians in the province of New Brunswick, Canada face numerous challenges while practicing in rural areas. The most important challenges are not medical or technical in nature, but the 'soft' issue of maintaining professional and private boundaries. Rural physicians, when off duty, want privacy. Rural family physicians have to become more assertive about their needs, while at the same time, patients have to realize that off-duty physicians are private citizens.
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Miedema B, Easley J, Fortin P, Hamilton R, Tatemichi S. Disrespect, harassment, and abuse: all in a day's work for family physicians. CANADIAN FAMILY PHYSICIAN MEDECIN DE FAMILLE CANADIEN 2009; 55:279-85. [PMID: 19282539 PMCID: PMC2654822] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
OBJECTIVE To examine harassment and abusive encounters between family physicians and their patients or colleagues in the workplace. DESIGN Qualitative case study using semistructured interviews. SETTING Province of New Brunswick. PARTICIPANTS Forty-eight family physicians from across the province. METHODS A collective case-study approach was developed, with 24 cases of 2 individuals per case. Cases were selected based on sex, location (urban or rural), language (French or English), and number of years since medical school graduation (< 10 years, 10 to 20 years, or > 20 years). Physicians were interviewed in either French or English. Participants were recruited using the College of Physicians and Surgeons of New Brunswick's physician directory. Based on the rates of response and participation, some cases were overrepresented, while others were not completed. All interviews were audiotaped, transcribed verbatim, and analyzed thematically using a categorical aggregation approach. A coding scheme for the thematic analysis was developed by the research team before the interviews were transcribed. MAIN FINDINGS Although the original intent of this study was to examine the work environment of family physicians in light of the increasing number of women entering the profession, harassment and abusive encounters in the workplace emerged as a main theme. These encounters ranged from minor to severe. Minor abusive encounters included disrespectful behaviour and verbal threats by patients, their families, and occasionally colleagues. More severe forms of harassment involved physical threats, physical encounters, and stalking. Demanding patients, such as heavy drug users, were often seen as threatening. Location of practice, years in practice, and sex of the physician seemed to affect abusive encounters--young, female, rural physicians appeared to experience such encounters most often. CONCLUSION Abusive encounters in the workplace are concerning. It is essential to address these issues of workplace harassment and abuse in order to protect physician safety and avoid workplace dissatisfaction. Abusive encounters might push family physicians to leave clinical practice prematurely or refuse to work in higher-risk environments, such as emergency departments or rural areas.
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Logan BK, Goldfogel G, Hamilton R, Kuhlman J. Five Deaths Resulting from Abuse of Dextromethorphan Sold Over the Internet. J Anal Toxicol 2009; 33:99-103. [DOI: 10.1093/jat/33.2.99] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Miedema B, Easley J, Fortin P, Hamilton R, Tatemichi S. Crossing boundaries: family physicians' struggles to protect their private lives. CANADIAN FAMILY PHYSICIAN MEDECIN DE FAMILLE CANADIEN 2009; 55:286-287.e5. [PMID: 19282540 PMCID: PMC2654825] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
OBJECTIVE To explore the tensions between professional and personal boundaries and how they affect the work and private lives of family physicians. DESIGN Qualitative case study using semistructured interviews. SETTING Province of New Brunswick. PARTICIPANTS Forty-eight family physicians from across the province. METHODS A collective case-study approach was developed, with 24 cases of 2 individuals per case. Cases were selected based on sex, location (urban or rural), language (French or English), and number of years since medical school graduation (< 10 years, 10 to 20 years, or > 20 years). Physicians were interviewed in either French or English. Participants were recruited using the College of Physicians and Surgeons of New Brunswick's physician directory. Based on the rates of response and participation, some cases were overrepresented, while others were not completed. All interviews were audiotaped, transcribed verbatim, and analyzed thematically using a categorical aggregation approach. A coding scheme for the thematic analysis was developed by the research team before the interviews were transcribed. MAIN FINDINGS Almost all of the family physicians interviewed discussed how their profession negatively affected their personal lives. Many struggled with issues such as heavy workloads, the adverse effects of their profession on their family lives, and the trespassing of patients onto their personal lives in small towns and rural communities. Some physicians had developed strategies to balance their personal lives with their professional demands; however, this often meant reducing work hours or terminating certain shifts, such as those in the emergency department or after-hours clinics. CONCLUSION Family physicians struggle to keep their profession from intruding too much into their private lives. These struggles are important to acknowledge and address in order to avoid physician burnout and premature retirement from clinical practice.
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Kara-Zaitri C, Hamilton R, Gelletlie D, Schweiger M, Barnes H. Real-time Decision Support and Intelligence for Prevention and Control of Infectious Disease in the United Kingdom. Int J Infect Dis 2008. [DOI: 10.1016/j.ijid.2008.05.472] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Creutzenberg O, Hansen T, Ernst H, Muhle H, Oberdörster G, Hamilton R. Toxicity of a Quartz with Occluded Surfaces in a 90-Day Intratracheal Instillation Study in Rats. Inhal Toxicol 2008; 20:995-1008. [DOI: 10.1080/08958370802123903] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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McGlone L, Mactier H, Hamilton R, Bradnam MS, Boulton R, Borland W, Hepburn M, McCulloch DL. Visual evoked potentials in infants exposed to methadone in utero. Arch Dis Child 2008; 93:784-6. [PMID: 18305073 DOI: 10.1136/adc.2007.132985] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
We investigated the effects of maternal drug misuse on neonatal visual evoked potentials (VEPs). Flash VEPs were recorded within 4 days of birth from 21 term infants of mothers misusing drugs and prescribed substitute methadone and 20 controls. Waveforms were classified as typical, atypical, immature or non-detectable, and amplitude and latencies were measured. VEPs from drug-exposed infants were less likely to be of typical waveform and more likely to be immature or non-detectable (p<0.01) than those of control infants. They were also smaller in amplitude (median 10.8 vs 24.4 microV, p<0.001). VEPs of drug-exposed infants had matured after 1 week but remained of lower amplitude than VEPs of newborn controls (p<0.01) and were non-detectable in 15%. Flash VEPs differ between maternal drug-exposed and non-drug-exposed newborns. Future research should address the specific effects of maternal methadone and/or other illicit drug misuse on infant VEPs, and associations between neonatal VEPs and subsequent visual development.
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Abstract
An 11 year old girl presented with an 8 month history of left temporal headaches with new onset of nausea and vomiting with increased severity of headaches. An MRI scan showed a frontal lobe mass. The tumor was resected and histologic studies demonstrated a central neurocytoma. The clinical, radiologic and pathologic aspects (including immunohistochemistry and electron microscopy) of central neurocytomas are reviewed and the atypical features of this case described.
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Balaban B, Urman B, Ata B, Isiklar A, Larman MG, Hamilton R, Gardner DK. A randomized controlled study of human Day 3 embryo cryopreservation by slow freezing or vitrification: vitrification is associated with higher survival, metabolism and blastocyst formation. Hum Reprod 2008; 23:1976-82. [PMID: 18544577 DOI: 10.1093/humrep/den222] [Citation(s) in RCA: 187] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND The aim of this study was to compare two methods of cryopreservation for the cleavage-stage human embryo: slow freezing and vitrification. METHODS A total of 466 Day 3 embryos, donated with consent, underwent cryopreservation by either slow freezing in straws or vitrification using the cryoloop. The vitrification procedure did not include dimethyl sulfoxide, but rather employed ethylene glycol and 1,2-propanediol as the cryoprotectants. Survival, embryonic metabolism and subsequent development to the blastocyst were used to determine the efficacy of the two procedures. RESULTS Significantly, more embryos survived the vitrification procedure (222/234, 94.8%) than slow freezing (206/232, 88.7%; P < 0.05). Consistent with this observation, pyruvate uptake was significantly greater in the vitrification group, reflecting a higher metabolic rate. Development to the blastocyst was also higher following vitrification (134/222, 60.3%) than following freezing (106/206, 49.5%; P < 0.05). In a separate cohort of 73 patients who had their supernumerary embryos cyropreserved with vitrification, the resulting implantation rate and clinical pregnancy rate were 30 and 49%, respectively. CONCLUSIONS Analysis of metabolism revealed that vitrification had less impact on the metabolic rate of the embryo than freezing, which was reflected in higher survival rate and subsequent development in vitro. Excellent pregnancy outcomes followed the warming and transfer of vitrified cleavage-stage embryos. These data provide further evidence that vitrification imparts less trauma to cells and is, therefore, a more effective means of cryopreserving the human embryo than conventional slow freezing. Clinicaltrials.gov identifier: NCT00608010.
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Raman R, Hamilton R, Das S, Gallagher G, Sharma H. Hemiarthroplasty for intracapsular fractures of the proximal femur using HAC coated endoprosthesis—A study of outcomes and health economics in 515 patients. ACTA ACUST UNITED AC 2008. [DOI: 10.1016/j.injury.2007.11.400] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Hamilton R, Braun B, Koopman B, Svoronos SA. Estimation of nitrate reductase enzyme parameters in activated sludge using an extended Kalman filter algorithm. WATER RESEARCH 2008; 42:1889-1896. [PMID: 18067944 DOI: 10.1016/j.watres.2007.11.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2007] [Revised: 11/11/2007] [Accepted: 11/14/2007] [Indexed: 05/25/2023]
Abstract
This paper demonstrates an application of the extended Kalman filter to a wastewater plant using real process data to estimate parameters in a semi-mechanistic model. This technique for parameter identification allows a semi-mechanistic model developed for pure cultures to be applied to a mixed culture population where isolation of enzyme kinetic parameters is not practical. This paper demonstrates an application in which a wastewater treatment facility with three physical unit operations and an unusual operating profile is modeled as 11 reactor units with recirculation streams. On-line nutrient probe data from two locations in the aerobic reactor are combined with operational data for flows and feed composition. This paper demonstrates the successful application of a biochemical model developed at the bench scale to this facility through the use of an extended Kalman filter. The estimated biological model parameters and the covariance matrix diagonal converge to stable values, indicating a successful implementation.
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Miedema B, Hamilton R, Easley J. Climbing the walls: Structural barriers to accessing primary care for refugee newcomers in Canada. CANADIAN FAMILY PHYSICIAN MEDECIN DE FAMILLE CANADIEN 2008; 54:335-339. [PMID: 18337519 PMCID: PMC2278339] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
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Cobine CA, Fong M, Hamilton R, Keef KD. Species dependent differences in the actions of sympathetic nerves and noradrenaline in the internal anal sphincter. Neurogastroenterol Motil 2007; 19:937-45. [PMID: 17973631 DOI: 10.1111/j.1365-2982.2007.00982.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Excitatory motor innervation to the internal anal sphincter (IAS) of the monkey, the rabbit and mouse were compared. Contractile responses to electrical field stimulation of nerves (EFS, atropine 1 micromol L(-1) and N(omega)-nitro-L-arginine 100 micromol L(-1) present throughout) were examined in isolated strips of IAS. In the monkey IAS, EFS caused frequency dependent (1-30 Hz) contractions which were abolished by guanethidine (10 micromol L(-1)) or phentolamine (3 micromol L(-1)). The sympathetic neurotransmitter noradrenaline (NA) also caused concentration-dependent (10 nmol L(-1)-100 micromol L(-1)) contractions which were abolished by phentolamine revealing a small relaxation that was abolished by propranolol (3 micromol L(-1)). In contrast, EFS caused only relaxation of the mouse and rabbit IAS which was not affected by guanethidine. Furthermore, NA relaxed these muscles and relaxation was nearly abolished by combined addition of phentolamine and propranolol. In conclusion, the monkey IAS is functionally innervated by sympathetic nerves that contract the muscle via excitatory alpha-adrenergic receptors. In contrast, no significant motor function could be identified for sympathetic nerves in the rabbit or mouse IAS although adrenergic receptors linked to muscle inhibition are present. These data reveal species dependent differences in sympathetic motor innervation and suggest that some species are more appropriate than others as models for motor innervation to the human IAS.
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Hamilton R, Bees MA, Chaplin CA, McCulloch DL. The luminance-response function of the human photopic electroretinogram: a mathematical model. Vision Res 2007; 47:2968-72. [PMID: 17889925 DOI: 10.1016/j.visres.2007.04.020] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2006] [Revised: 04/20/2007] [Accepted: 04/28/2007] [Indexed: 11/17/2022]
Abstract
The luminance-response function of the brief flash full-field photopic electroretinogram (ERG) rises to a peak before falling to a sub-maximal plateau -- the 'photopic hill'. The combination of on- and off-responses inherent in the brief flash photopic ERG suggests that this luminance-response function could be modelled by the sum of a Gaussian function and a logistic growth function. Photopic ERGs to a luminance series of brief flashes against three different background luminances recorded from seven healthy adults showed the characteristic 'photopic hill' function for b-wave amplitudes which were satisfactorily fitted with the sum of a Gaussian curve and a logistic growth curve. As background luminance increased, both components shifted to the right on the luminance axis. The Gaussian component increased in amplitude while the logistic growth function component decreased in amplitude. The luminance-response function of a complete congenital stationary night blindness patient had almost no logistic growth component.
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Xu Q, Hamilton R, Schowengerdt R, Jiang S. TH-C-M100F-04: A Deformable Lung Tumor Tracking Method in Fluoroscopic Video Using Active Shape Models. Med Phys 2007. [DOI: 10.1118/1.2761682] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Miedema B, Hamilton R, Easley J. From "invincibility" to "normalcy": coping strategies of young adults during the cancer journey. Palliat Support Care 2007; 5:41-9. [PMID: 17461370 DOI: 10.1017/s147895150707006x] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
OBJECTIVE Little research has been undertaken regarding the psychological impact of cancer on those stricken during the young adult years. Specifically, research on the coping strategies of young adults with cancer is limited. METHOD In this qualitative, Grounded Theory study, we did not set out to examine coping; rather, it emerged as a major phenomenon in the analysis of interview data from 15 young adults with cancer. RESULTS These young adults used various coping strategies to come to terms with the cancer diagnosis, management of the illness, its treatment, and treatment sequelae. The coping strategies varied considerably from person to person, depended on the stage(s) of the illness, and were rooted in their precancer lives. We were able to discern a pattern of coping strategies used by most participants. The prevailing goal for all participants was to achieve what they called "normalcy." For some, this meant major changes in their lives; for others it meant to "pick up" where they had left off before the cancer diagnosis. SIGNIFICANCE OF RESULTS To aid the understanding of the issues that influence coping, we have developed a model to illustrate the bidirectional nature and the complexities of the coping strategies as they relate to the phases of the disease and the disease treatment. The model also affirms Folkman and Lazarus' coping theory.
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Wiler J, Hamilton R, Mead P. Effect of Peer to Peer Education on Emergency Physician Critical Care Documentation Practices. Acad Emerg Med 2007. [DOI: 10.1197/j.aem.2007.03.1301] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Tzetzi D, Hamilton R, Robinson PH, Dutton GN. Negative ERGs in mucopolysaccharidoses (MPS) Hurler–Scheie (I-H/S) and Hurler (I-H)-syndromes. Doc Ophthalmol 2007; 114:153-8. [PMID: 17464575 DOI: 10.1007/s10633-007-9047-z] [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: 09/13/2005] [Indexed: 11/24/2022]
Abstract
The configuration and progression of the ERG in two children with mucopolysaccharidosis (MPS) I H/S (Hurler-Scheie syndrome) and MPS I H (Hurler syndrome) is described. Physical examination, biochemical analysis, ophthalmic examination and electroretinography were performed. The Hurler-Scheie patient (case 1) showed negative scotopic but normal photopic ERGs, which remained unchanged over 2 years. The Hurler patient (case 2) showed negative scotopic and photopic ERGs which did not alter after bone marrow transplantation (BMT). One year after BMT, further b-wave amplitude reduction had caused the ERGs to become more negative. The electronegative configuration of the ERGs suggests that, in these cases of MPS, the primary retinal abnormality in MPS I may be faulty synaptic transmission from photoreceptors to more proximal elements, deficient bipolar responsivity, or Muller cell disease. Further degradation with time suggests the defect to be progressive with BMT causing little or no improvement. In the Hurler-Scheie syndrome case, the defect appears to spare the cone system and to show little or no progression.
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Hsiai TK, Hwang J, Barr ML, Correa A, Hamilton R, Alavi M, Rouhanizadeh M, Cadenas E, Hazen SL. Hemodynamics influences vascular peroxynitrite formation: Implication for low-density lipoprotein apo-B-100 nitration. Free Radic Biol Med 2007; 42:519-29. [PMID: 17275684 PMCID: PMC2561143 DOI: 10.1016/j.freeradbiomed.2006.11.017] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/07/2006] [Revised: 11/10/2006] [Accepted: 11/15/2006] [Indexed: 12/27/2022]
Abstract
Hemodynamics, specifically, fluid shear stress, modulates the focal nature of atherogenesis. Superoxide anion (O2(-.)) reacts with nitric oxide (.NO) at a rapid diffusion-limited rate to form peroxynitrite (O2(-.) + .NO-->ONOO(-)). Immunohistostaining of human coronary arterial bifurcations or curvatures, where OSS develops, revealed the presence of nitrotyrosine staining, a fingerprint of peroxynitrite; whereas in straight segments, where PSS occurs, nitrotyrosine was absent. We examined vascular nitrative stress in models of oscillatory (OSS) and pulsatile shear stress (PSS). Bovine aortic endothelial cells (BAEC) were exposed to fluid shear stress that simulates arterial blood flow: (1) PSS at a mean shear stress (tau(ave)) of 23 dyn cm(-2) and a temporal gradient (partial differential(tau)/partial differential(t)) at 71 dyn cm(-2) s(-1), and (2) OSS at tau(ave) = 0.02 dyn cm(- 2) and partial differential(tau)/partial differential(t) = +/- 3.0 dyn cm(-2) s(-1) at a frequency of 1 Hz. OSS significantly up-regulated one of the NADPH oxidase subunits (NOx4) expression accompanied with an increase in O2(-.) production. In contrast, PSS up-regulated eNOS expression accompanied with .NO production (total NO(2)(-) and NO(3)(-)). To demonstrate that O2(-.) and .NO are implicated in ONOO(-) formation, we added low-density lipoprotein cholesterol (LDL) to the medium in which BAEC were exposed to the above flow conditions. The medium was analyzed for LDL apo-B-100 nitrotyrosine by liquid chromatography electrospray ionization tandem mass spectrometry (LC/ESI/MS/MS). OSS induced higher levels of 3-nitrotyrosine, dityrosine, and o-hydroxyphenylalanine compared with PSS. In the presence of ONOO(-), specific apo-B-100 tyrosine residues underwent nitration in the alpha and beta helices: alpha-1 (Tyr(144)), alpha-2 (Tyr(2524)), beta-2 (Tyr(3295)), alpha-3 (Tyr(4116)), and beta-2 (Tyr(4211)). Hence, the characteristics of shear stress in the arterial bifurcations influenced the relative production of O2(-.) and .NO with an implication for ONOO(-) formation as evidenced by LDL protein nitration.
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Boada FE, Tanase C, Davis D, Walter K, Torres-Trejo A, Couce M, Hamilton R, Kondziolka D, Bartynski W, Lieberman F. Non-invasive assessment of tumor proliferation using triple quantum filtered 23/Na MRI: technical challenges and solutions. CONFERENCE PROCEEDINGS : ... ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL CONFERENCE 2007; 2004:5238-41. [PMID: 17271521 DOI: 10.1109/iembs.2004.1404464] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
We address the development of triple-quantum-filtered sodium MRI as a non-invasive surrogate measure for cell proliferation in brain tumors. We demonstrate that through careful consideration of the theoretical description of the signal, triple-quantum-filtered sodium images of adequate signal-to-noise ratio (SNR) can be acquired in clinically acceptable imaging times.
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Hamilton R, Fontanesi J. Concurrent chemotherapy and radiation therapy in locally-advanced head and neck cancer patientsa single institution experience. Radiother Oncol 2007. [DOI: 10.1016/s0167-8140(07)80150-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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