50 results on '"Darwich R"'
Search Results
2. Characterization of defects in hydrogenated amorphous silicon deposited on different substrates by capacitance techniques
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Darwich, R. and Cabarrocas, P. Roca i
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- 2011
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3. High deposition rate hydrogenated polymorphous silicon characterized by different capacitance techniques
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Darwich, R. and Cabarrocas, P. Roca i
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- 2011
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4. DLTS properties of iron defects in crystalline silicon used in solar cells
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Hamadeh, H. and Darwich, R.
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- 2004
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5. LB1590 Trends in the epidemiology and distribution of ocular melanoma in Canada
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Al Ghazawi, F.M., primary, Darwich, R., additional, Rahme, E., additional, Sasseville, D., additional, Burnier, M.N., additional, and Litvinov, I., additional
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- 2018
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6. Material de fusão de artrodese cervical anterior solto é de tratamento cirúrgico?
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Barroso, P. M. C., additional, Dantas, F. L. R., additional, Dantas, F., additional, Filho, G. A. F., additional, Darwich, R. Z., additional, and Hon, Y., additional
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- 2018
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7. Revealing substructures of H4 and H5 hole traps in p-type InP using Laplace deep-level transient spectroscopy.
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Darwich, R. and Mani, A. A.
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SPECTRUM analysis , *LAPLACE transformation , *HOLES (Electron deficiencies) , *MICROSCOPY , *MOLECULAR structure - Abstract
New substructures of H4 and H5 hole traps have been revealed using Laplace deep-level transient spectroscopy. Our measurements show that the hole traps H4 and H5 can have at least three components for each. Moreover, the activation energies are deduced and the microscopic nature of these substructures is discussed. [ABSTRACT FROM AUTHOR]
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- 2010
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8. Electric field effect on the carrier capture of deep traps in p-type InP.
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Darwich, R. and Sabra, M. K.
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ELECTRON capture , *HOLES (Electron deficiencies) , *MULTIPHOTON processes , *EFFECTIVE mass (Physics) , *HAMILTONIAN systems , *COMPLEX compounds , *INDIUM , *PHOSPHORUS - Abstract
The electric field effect on the carrier capture cross section of deep traps has been studied. The experimental results on the H4F and H5 hole traps in p-type InP show an enhancement of the capture cross section with the increase in the applied electric field. This enhancement depends on the nature of the deep traps and its peak temperature. Increasing the electric field from 4.1×106 to 2.4×107 V/m leads to an increase in the H4F capture cross section by a factor of 3 to 20. While in the case of H5 it increases by a factor of 2 to 5 by increasing the applied electric field from 8.0×106 to 2.4×107 V/m. A theoretical model has been suggested to explain the electric field effect on the capture cross section. This model deals with the cascade and multiphonon processes semiclassically. Applying this model to the above deep traps, we have found that H4F is negatively charged complex and H5 is positively charged complex. [ABSTRACT FROM AUTHOR]
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- 2010
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9. Electric field effect on the emission rate of H4F and H4S hole traps in InP.
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Darwich, R. and Alek, B.
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ELECTRIC fields , *HOLES (Electron deficiencies) , *INDIUM phosphide , *DEEP level transient spectroscopy , *ZINC , *PHONONS , *QUANTUM tunneling - Abstract
The electric field effect on the emission rate enhancement of the H4F and H4S hole trap in highly Zn-doped InP has been examined using the deep level transient spectroscopy (DLTS) and double correlation DLTS (DDLTS). The DLTS and DDLTS results have been found to be in good agreement for low and intermediate electric fields, but they disagree for large field effect. Comparing our emission data with the theory, we have found that H4F obeys the quantum model of phonon-assisted tunneling, while H4S follows the Poole¿Frenkel model employing a three-dimensional screening Coulombic potential. Our results show that the H4S defect can be attributed to a charged (Vp¿Zn) complex. [ABSTRACT FROM AUTHOR]
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- 2009
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10. Experimental determination of the hole capture kinetics of H4 F deep trap in electron-irradiated highly doped p-type InP.
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Darwich, R. and Massarani, B.
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INDIUM phosphide , *DEEP level transient spectroscopy , *SPACE charge , *ELECTRIC fields , *ELECTROMAGNETIC fields , *PHYSICS - Abstract
The hole capture kinetics of the main trap H4F, in electron-irradiated p-type InP has been investigated by experimentally determining the exponential and nonexponential parts. The contribution of the slow part of the total kinetics is about 30% in our samples. An indication to a possible capture rate enhancement due to the electric field in the space-charge region is pointed out. [ABSTRACT FROM AUTHOR]
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- 2004
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11. Effect of fill-pulse parameters on deep-level transient spectroscopy peaks in highly doped p-type...
- Author
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Darwich, R. and Massarani, B.
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THIN films , *SEMICONDUCTOR doping - Abstract
Studies the effect of different fill-pulse parameters on the characterizations of deep-level transient spectroscopy peaks in highly doped thin films. Applied reverse bias; Pulse amplitude; Pulse frequency; Pulse duration.
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- 2000
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12. Electric field effect on the emission rate of [H4.sub.F] and [H4.sub.S] hole traps in InP
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Darwich, R. and Alek, B.
- Subjects
Electric fields -- Evaluation ,Holes (Electron deficiencies) -- Analysis ,Indium -- Electric properties ,Semiconductor doping -- Analysis ,Zinc -- Electric properties ,Physics - Abstract
The deep level transient spectroscopy (DLTS) and double correlation DLTS (DDLTS) were used to examine the electric field effect on the emission rate enhancement of the [H4.sub.F] and [H4.sub.S] hole trap in highly Zn-doped InP. The results for [H4.sub.S] which follows the Poole-Frenkel model revealed that the defect observed in [H4.sub.S] could be attributed to a charged ([V.sub.p]-Zn) complex.
- Published
- 2009
13. Nuclear receptor–like structure and interaction of congenital heart disease–associated factors GATA4 and NKX2–5
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Kinnunen, S. (Sini), Välimäki, M. (Mika), Tölli, M. (Marja), Wohlfahrt, G. (Gerd), Darwich, R. (Rami), Komati, H. (Hiba), Nemer, M. (Mona), and Ruskoaho, H. (Heikki)
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embryonic structures ,cardiovascular system ,respiratory system - Abstract
Aims: Transcription factor GATA4 is a dosage sensitive regulator of heart development and alterations in its level or activity lead to congenital heart disease (CHD). GATA4 has also been implicated in cardiac regeneration and repair. GATA4 action involves combinatorial interaction with other cofactors such as NKX2‐5, another critical cardiac regulator whose mutations also cause CHD. Despite its critical importance to the heart and its evolutionary conservation across species, the structural basis of the GATA4‐NKX2‐5 interaction remains incompletely understood. Methods and results: A homology model was constructed and used to identify surface amino acids important for the interaction of GATA4 and NKX2‐5. These residues were subjected to site-directed mutagenesis, and the mutant proteins were characterized for their ability to bind DNA and to physically and functionally interact with NKX2‐5. The studies identify 5 highly conserved amino acids in the second zinc finger (N272, R283, Q274, K299) and its C–terminal extension (R319) that are critical for physical and functional interaction with the third alpha helix of NKX2‐5 homeodomain. Integration of the experimental data with computational modeling suggests that the structural arrangement of the zinc finger–homeodomain resembles the architecture of the conserved DNA binding domain of nuclear receptors. Conclusions: The results provide novel insight into the structural basis for protein-protein interactions between two important classes of transcription factors. The model proposed will help to elucidate the molecular basis for disease causing mutations in GATA4 and NKX2‐5 and may be relevant to other members of the GATA and NK classes of transcription factors.
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- 2015
14. Photo-induced changes of hydrogen bonding in semi-insulating iron-doped indium phosphide
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Gendron F, B. Pajot, Darwich R, Christopher P. Ewels, and Song Cy
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business.industry ,Hydrogen bond ,Inorganic chemistry ,Analytical chemistry ,General Chemistry ,Trapping ,Condensed Matter Physics ,Gallium arsenide ,law.invention ,chemistry.chemical_compound ,Semiconductor ,chemistry ,Impurity ,law ,Metastability ,Materials Chemistry ,Indium phosphide ,business ,Electron paramagnetic resonance - Abstract
After illumination with 1–1.3 eV photons during cooling-down, metastable PH modes are observed by IR absorption at 5 K in semi-insulating InP:Fe. They correlate with the photo-injection of holes, but not with a change of the charge state of the H-related centres present at equilibrium. They are explained by a change of the bonding of H, induced by hole trapping, from IR-inactive centres to PH-containing centres, stable only below 80 K. One metastable centre has well-defined geometrical parameters and the other one could be located in a region near from the interface with (Fe,P) precipitates.
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- 1995
15. ZnO Nanopowders as Chemical Sensor to Malathion Vapor
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Al-Mohammad, A., primary, Darwich, R., additional, Rukiah, M., additional, Abo Shaker, S., additional, and Kakhia, M., additional
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- 2014
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16. Carrier emission from defects in intrinsic hydrogenated amorphous silicon studied by junction-capacitance methods
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Darwich, R., primary
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- 2013
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17. Experimental determination of the hole capture kinetics of H4F deep trap in electron-irradiated highly doped p-type InP
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Darwich, R., primary and Massarani, B., additional
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- 2004
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18. Hydrogen passivated defects in InP
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Patrick R. Briddon, Darwich R, R. Jones, Jonathan P. Goss, Christopher P. Ewels, B. Pajot, Sven Öberg, and S J Breuer
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Materials science ,Hydrogen ,chemistry ,Materials Chemistry ,chemistry.chemical_element ,General Chemistry ,Condensed Matter Physics ,Photochemistry - Published
- 1995
19. ZnO Nano-powders as Chemical Sensor to Malathion Vapor.
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AL-MOHAMMAD, A., DARWICH, R., RUKIAH, M., SHAKER, S. ABO, and KAKHIA, M.
- Subjects
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THICK films , *MALATHION , *ORGANOPHOSPHORUS compounds , *CHOLINESTERASE-inhibiting insecticides , *ZINC oxide - Abstract
Thick films of zinc oxide (ZnO) nanopowders have been prepared by high energy ball-milling for various spans of mill time (3-18 h). The morphology and crystal structure of the prepared ZnO powder were characterized by scanning electron microscope and X-ray diffraction. The ZnO thick films were then used to construct a gas sensor for O,O-dimethyl dithiophosphate of diethyl mercaptosuccinate (malathion) at different operating temperatures. The sensor response at 100 ppm of malathion was found to reach a maximum as large as 80 at 6 h of high energy ball-milling, four times larger than that found for ethanol. Scanning electron microscope observation of the granular state and pore size distribution analyses indicated that increasing high energy ball-milling time gave rise especially to an increase in the volume of pores in the pore size range of 6-35 nm. It is suggested that such a change in nanostructure is responsible for the marked promotion of the response to malathion. [ABSTRACT FROM AUTHOR]
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- 2014
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20. Evidence for two distinct defects contributing to theH4deep-level transient spectroscopy peak in electron-irradiated InP
- Author
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Massarani, B., primary, Awad, F. G., additional, Kaaka, M., additional, and Darwich, R., additional
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- 1998
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21. Spontaneous Resolution of a Ruptured Dissecting PICA Aneurysm
- Author
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Piske, R.L., primary, Darwich, R., additional, Campos, C.M.S., additional, Fonseca, N.C., additional, Oliveira, E., additional, and Souza, A., additional
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- 1998
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22. Photo-induced changes of hydrogen bonding in semi-insulating iron-doped indium phosphide
- Author
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Pajot, B., primary, Song, C-Y, additional, Darwich, R., additional, Gendron, F., additional, and Ewels, C., additional
- Published
- 1995
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23. Observation by infrared transmission spectroscopy and infrared ellipsometry of a new hydrogen bond during light-soaking of a-Si:H
- Author
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Darwich, R., primary, Cabarrocas, P. Roca I, additional, Vallon, S., additional, Ossikovski, R., additional, Morin, P., additional, and Zellama, K., additional
- Published
- 1995
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24. Hydrogen passivated defects in InP
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Ewels, C.P, primary, Öberg, S, additional, Briddon, P.R, additional, Goss, J, additional, Jones, R, additional, Breuer, S.J, additional, Darwich, R, additional, and Pajot, B, additional
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- 1995
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25. Experimental study of the hydrogen complexes in indium phosphide
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Darwich, R., primary, Pajot, B., additional, Rose, B., additional, Robein, D., additional, Theys, B., additional, Rahbi, R., additional, Porte, C., additional, and Gendron, F., additional
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- 1993
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26. Interaction between X-H Bonds and the Lattice in III-V Compounds Determined from Temperature-Dependent Spectroscopic Studies
- Author
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Darwich, R., primary, Song, C., additional, Rahbi, R., additional, and Pajot, B., additional
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- 1993
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27. Directive for interpretation of rest ECG,Diretriz de interpretação de eletrocardiograma de repouso
- Author
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Guimarães, J. I., jose nicolau, Polanczyk, C. A., Pastore, C. A., Pinho, J. A., Carvalho Bacellar, M. S., Ribeiro, D. G. L., Darwich, R. N., Ribeiro, A. L. P., Dunda, M. M. E., Germiniani, H., França, F. F., Saraiva, L., Ribeiro, C. M. R., Ginefra, P., Gus, I., Fernandes, E., Riera, A., Pedrosa, A., Friedman, A. A., Firmiani, A. C., Grupi, C., Pinho, C., Lima, E. V., Kaiser, E., Brito, F. S., Vinhas, G. L. C., Schwartz, H., Grindler, J., Aziz, J. L., Figueiredo, M., Molina, M. S., Martinelli, M., Tobias, N., Sanches, P. C. R., Moffa, P. J., Neto, S. A., and Nishioka, S.
28. Medications for attention deficit hyperactivity disorder associated with increased risk of developing glaucoma.
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Darwich R, Etminan M, He B, and Eadie BD
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- Humans, Female, Male, Retrospective Studies, Middle Aged, Adult, Case-Control Studies, Risk Factors, Adrenergic Uptake Inhibitors adverse effects, Adrenergic Uptake Inhibitors therapeutic use, Incidence, Aged, Intraocular Pressure drug effects, Intraocular Pressure physiology, Young Adult, Attention Deficit Disorder with Hyperactivity drug therapy, Attention Deficit Disorder with Hyperactivity epidemiology, Methylphenidate adverse effects, Methylphenidate therapeutic use, Atomoxetine Hydrochloride therapeutic use, Atomoxetine Hydrochloride adverse effects, Central Nervous System Stimulants adverse effects, Central Nervous System Stimulants therapeutic use, Amphetamines adverse effects, Glaucoma, Angle-Closure chemically induced, Glaucoma, Angle-Closure epidemiology, Glaucoma, Open-Angle drug therapy, Glaucoma, Open-Angle epidemiology, Glaucoma, Open-Angle chemically induced
- Abstract
Background: Attention deficit hyperactivity disorder (ADHD) therapies including atomoxetine, methylphenidate, and amphetamines are some of the most prescribed medications in North America. Due to their sympathomimetic action, these drugs are contraindicated in patients with a history of angle closure glaucoma (ACG). This study aims to determine the risk of ACG and open angle glaucoma (OAG) among users of these treatments., Methods: This is a retrospective cohort study with a case control analysis using the PharMetrics Plus Database (IQVIA, USA). We created a cohort of new users of atomoxetine, methylphenidate, and amphetamines and they were followed to the first diagnosis of (1) ACG or OAG; or (2) end of follow up. For each case, four age-matched controls were selected. A conditional logistic regression model was used to adjust for confounders and to calculate adjusted incidence-rate-ratios (aIRRs)., Results: A total of 240,257 new users of the ADHD medications were identified. The mean age was 45.0 ± 19.4 years and 55% of the cohort was female. Regular users of atomoxetine and amphetamines had a higher aIRR for developing ACG compared with non-users (aIRR = 2.55 95% CI [1.20-5.43] and 2.27 95% CI [1.42-3.63], respectively); while users of methylphenidate had a higher aIRR for developing OAG (aIRR = 1.23 95% CI [1.05-1.59])., Conclusions: Use of amphetamines and atomoxetine had a higher risk for ACG, while use of methylphenidate was associated with a higher risk for OAG. Given the prevalence of ADHD medication use (medically and recreationally), our current data on their associated risk of glaucoma have profound public health implications., (© 2024. The Author(s), under exclusive licence to The Royal College of Ophthalmologists.)
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- 2024
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29. Facial Swelling After External Dacryocystorhinostomy.
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Herod T, Darwich R, and Hussain A
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- Humans, Middle Aged, Edema etiology, Edema diagnosis, Face, Lacrimal Duct Obstruction diagnosis, Lacrimal Duct Obstruction etiology, Postoperative Complications diagnosis, Tomography, X-Ray Computed, Dacryocystorhinostomy adverse effects
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- 2024
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30. Analysis of deep optic nerve head structures with spectral domain and swept-source optical coherence tomography.
- Author
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Darwich R, Jarrar F, Syed M, Sharpe GP, and Chauhan BC
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- Humans, Female, Male, Aged, Middle Aged, Intraocular Pressure physiology, Sclera diagnostic imaging, Sclera pathology, Bruch Membrane pathology, Bruch Membrane diagnostic imaging, Nerve Fibers pathology, Optic Nerve Diseases diagnosis, Optic Nerve Diseases diagnostic imaging, Retinal Ganglion Cells pathology, Tomography, Optical Coherence methods, Optic Disk diagnostic imaging, Optic Disk pathology, Glaucoma, Open-Angle diagnostic imaging, Glaucoma, Open-Angle diagnosis
- Abstract
Purpose: Histological evidence indicates that the earliest structural changes to the optic nerve head (ONH) in glaucoma occur in the lamina cribrosa (LC) and its interface with the sclera. However, clinical imaging of these structures remains challenging. We compared the visibility of deep ONH structures with newer iterations of spectral-domain (SD) and swept-source (SS) optical coherence tomography (OCT)., Methods: Twelve patients with open-angle glaucoma were imaged with SD-OCT with 24 radial B-scans centred on Bruch's membrane opening (BMO) and SS-OCT with a horizontal and vertical raster scan pattern containing five lines each, centred on the ONH. Single best-matched horizontal and vertical scans from the two modalities were selected and exported. Three independent observers masked to modality determined if BMO, posterior choroid surface, anterior scleral canal opening and anterior and posterior LC insertions into the sclera were detectable in the matched B-scan images. We determined the interobserver agreement and concordance in detecting each structure with the two OCT imaging modalities., Results: There was a high interobserver agreement with both SS-OCT and SD-OCT (inter-item correlations: 0.81-0.93 and 0.77-0.82, respectively). There was a consistent tendency for higher overall detection rates with SS-OCT, however, the differences failed to reach statistical significance. With respect to individual structures, only the posterior LC insertion in the nasal quadrant was statistically different, with a detection rate of 13 and 6 (pooled out of a total of 36 across the three observers) with SS-OCT and SD-OCT, respectively (p=0.04)., Conclusion: Overall, both SS-OCT and SD-OCT showed statistically equivalent visualisation of ONH structures, however, SS-OCT tended to have higher visualisation rates., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)
- Published
- 2024
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31. PreserFlo Microshunt for the management of intraocular pressure elevation in iridocorneal endothelial syndrome.
- Author
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Ruparelia S, Darwich R, and Eadie BD
- Abstract
Purpose: To report on a case of angle-closure glaucoma secondary to iridocorneal endothelial (ICE) syndrome effectively managed with the PreserFlo Microshunt., Observations: We report successful implantation of a PreserFlo Microshunt in a 57-year-old patient with secondary angle-closure glaucoma in the context of ICE syndrome. Following failure of medical therapy to adequately control intraocular pressure (IOP), the patient was consented for surgical intervention and underwent combined cataract surgery and PreserFlo Microshunt implantation. IOP at the last post-operative follow-up (5 months) was 12 mmHg with the patient on brinzolamide/timolol maleate (Azarga®). We report no complications in the post-operative period., Conclusions and Importance: The PreserFlo Microshunt may be a promising option for patients with ICE syndrome who fail medical therapy. Implantation of this device was well tolerated in the presented case., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2023 The Authors.)
- Published
- 2023
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32. Endovascular treatment of intracranial aneurysms using the Derivo Embolization Device: a multicenter experience.
- Author
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Chagas Lourenço G, Dantas F, Silva E Carvalho T, Firmino RUR, Quesado Filgueiras Filho M, Tosello RT, José Leão C, Leo Piske R, and Zenóbio Darwich R
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- Humans, Retrospective Studies, Cerebral Angiography methods, Treatment Outcome, Stents, Follow-Up Studies, Intracranial Aneurysm diagnostic imaging, Intracranial Aneurysm therapy, Intracranial Aneurysm complications, Embolization, Therapeutic methods, Endovascular Procedures
- Abstract
Background: Flow diversion is the first-line treatment for several types of intracranial aneurysms. We report on a large series of patients treated with the Derivo Embolization Device who underwent a 1-year angiographic control follow-up., Methods: We performed a multicenter retrospective analysis of prospectively collected data, designed to evaluate the clinical and angiographic results of treatment of intracranial aneurysms with the Derivo Flow Diverter. The primary endpoint was complete occlusion of the aneurysm within 12 months, which was evaluated using DSA. The secondary endpoint was the absence of any serious adverse events. Univariate and multivariate logistic regression analyses were performed to analyze the data., Results: The study was conducted from December 2016 to September 2019 and enrolled 127 patients with 177 intracranial aneurysms, treated at three different centers. Efficacy at 6 months was 70.1% (122/174) for total occlusion and 87.3% (152/174) for favorable occlusion and, at 12 months, it was 83.3% (145/174) for total occlusion and 97.7% (170/174) for favorable occlusion. Regarding safety concerns, 97.6% (124/127) of patients did not experience severe adverse effects during the follow-up period of 12 months, and there was no procedure-related mortality., Conclusions: The Derivo Embolization Device, achieving a total occlusion rate of 83.3% and a favorable occlusion rate of 97.7% in a 1-year angiographic control study of 174 aneurysms with minor morbidity and no intervention-related mortality, is a safe and effective treatment for intracranial aneurysms., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2023. No commercial re-use. See rights and permissions. Published by BMJ.)
- Published
- 2023
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33. Annular pigment ring on the posterior lens capsule: a novel examination finding in blunt ocular trauma.
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Mustafa S, Mohammad S, Darwich R, and Lewis D
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- Humans, Eye, Posterior Capsule of the Lens, Eye Injuries complications, Eye Injuries diagnosis, Wounds, Nonpenetrating diagnosis, Lens, Crystalline
- Published
- 2023
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34. Short- and medium-term outcomes for patent ductus arteriosus stenting in neonates ≤2.5 kg with duct-dependent pulmonary circulation.
- Author
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Nasef MA, Shahbah DA, Batlivala SP, Darwich R, Qureshi AM, Breatnach CR, Linnane N, Walsh KP, Oslizlok P, McCrossan B, Momenah T, Alshahri A, Abdulhamed J, Arafat A, Tamimi OA, Diraneyya OM, Goldstein BH, and Kenny D
- Subjects
- Cardiac Catheterization adverse effects, Female, Humans, Infant, Infant, Newborn, Pulmonary Circulation, Retrospective Studies, Stents, Treatment Outcome, Ductus Arteriosus, Ductus Arteriosus, Patent complications, Ductus Arteriosus, Patent diagnostic imaging, Ductus Arteriosus, Patent therapy
- Abstract
Background: Morbidity with surgical systemic-to-pulmonary artery shunting (SPS) in infants ≤2.5 kg has remained high. Patent ductus arteriosus (PDA) stenting may be a valid alternative. The objective of this study is to evaluate outcomes following PDA stenting in patients ≤2.5 kg from four large tertiary centers., Methods: Retrospective review of all neonates ≤2.5 kg with duct-dependent pulmonary circulation who underwent PDA stenting. Procedural details, pulmonary arterial growth, reinterventions, surgery type, and outcomes were assessed., Results: PDA stents were implanted in 37 of 38 patients attempted (18 female) at a median procedural weight of 2.2 kg (interquartile range [IQR], 2-2.4 kg). Seven patients (18%) had a genetic abnormality and 16 (42%) had associated comorbidities. The median intensive care unit stay was 4 days (IQR, 2-6.75 days), and the median hospital stay was 20 days (IQR, 16-57.25). One patient required a rescue shunt procedure, with three others requiring early SPS (<30 days postprocedure). Twenty patients (54%) required reintervention with either balloon angioplasty, restenting, or both. At 6-month follow-up, right pulmonary artery growth (median z-score -1.16 to 0.01, p = 0.05) was greater than the left pulmonary artery (median z-score -0.9 to -0.64, p = 0.35). Serious adverse effects (SAEs) were seen in 18% (N = 7) of our cohort. One patient developed an SAE during planned reintervention There were no intraprocedural deaths, with one early procedure-related mortality, and three interstage mortalities not directly related to PDA stenting., Conclusions: PDA stenting in infants ≤2.5 kg is feasible and effective, promoting pulmonary artery growth. Reintervention rates are relatively high, though many are planned to allow for optimal growth before a definitive operation., (© 2022 Wiley Periodicals LLC.)
- Published
- 2022
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35. Isolated bilateral congenital lacrimal gland agenesis-a case series.
- Author
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Alghazawi N, Modabber M, Darwich R, Saskin A, Russell L, Saint-Martin C, and Khan A
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- Child, Humans, Magnetic Resonance Imaging, Eye Abnormalities diagnostic imaging, Lacrimal Apparatus diagnostic imaging, Lacrimal Apparatus Diseases diagnostic imaging
- Abstract
We report 2 pediatric cases of isolated bilateral congenital lacrimal gland agenesis (CLGA). Patient 1 (1 year of age) and patient 2 (2 years of age) presented with symptoms of alacrimia and were diagnosed with bilateral isolated CLGA based on magnetic resonance imaging. Both patients were otherwise healthy, with no systemic associations. Molecular analysis for genetic causes of CLGA were negative. Both have been successfully medically managed., (Copyright © 2021 American Association for Pediatric Ophthalmology and Strabismus. Published by Elsevier Inc. All rights reserved.)
- Published
- 2021
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36. Epidemiology of invasive ocular surface squamous neoplasia in Canada during 1992-2010.
- Author
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Darwich R, Ghazawi FM, Le M, Rahme E, Alghazawi N, Zubarev A, Moreau L, Sasseville D, Burnier MN Jr, and Litvinov IV
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- Adolescent, Adult, Aged, Aged, 80 and over, Canada epidemiology, Carcinoma, Squamous Cell pathology, Child, Child, Preschool, Conjunctival Neoplasms epidemiology, Conjunctival Neoplasms pathology, Corneal Diseases epidemiology, Corneal Diseases pathology, Eye Neoplasms pathology, Female, Geography, Humans, Incidence, Infant, Infant, Newborn, Lacrimal Apparatus Diseases epidemiology, Lacrimal Apparatus Diseases pathology, Male, Middle Aged, Registries, Carcinoma, Squamous Cell epidemiology, Eye Neoplasms epidemiology
- Abstract
Background: Ocular surface squamous neoplasia (OSSN) is the most common non-pigmented ocular surface malignancy. It is classified as invasive OSNN (IOSSN) when the underlying stroma are infiltrated by dysplastic squamous epithelial cells through the basement membrane. Here, we present the descriptive epidemiology and geographical distribution of IOSSN in Canada., Methods: We determined the incidence and geographical distribution of IOSSN cases diagnosed between 1992 and 2010 using two independent population-based cancer registries: the Canadian Cancer Registry and Le Registre Québécois du Cancer., Results: The mean annual age-standardised incidence rate (WHO 2000-2025) of IOSSN for 1992-2010 was 0.45 cases per million individuals per year with an average annual percent increase in incidence of 4.5%. IOSSN localisation to the conjunctiva was documented in at least 57% of the reported cases. IOSSN exhibited a male predilection ratio of 3.3:1.0 with a mean age at diagnosis of 69 years. Incidence rates of IOSSN across Canadian provinces and cities showed no significant differences from the crude national average., Conclusions: Our results, particularly concerning IOSSN patient age and male predilection, corroborate with data reported from the USA. Additional studies are needed to determine whether the observed increase in incidence rate over the study period (1992-2010) is significant., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2020. No commercial re-use. See rights and permissions. Published by BMJ.)
- Published
- 2020
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37. Epidemiology of ophthalmic lymphoma in Canada during 1992-2010.
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Darwich R, Ghazawi FM, Rahme E, Alghazawi N, Zubarev A, Moreau L, Sasseville D, Burnier MN Jr, and Litvinov IV
- Subjects
- Adolescent, Adult, Age Distribution, Aged, Aged, 80 and over, Canada epidemiology, Child, Child, Preschool, Eye Neoplasms pathology, Female, Geography, Humans, Incidence, Infant, Infant, Newborn, Lymphoma, B-Cell, Marginal Zone pathology, Lymphoma, Follicular pathology, Lymphoma, Large B-Cell, Diffuse pathology, Male, Middle Aged, Registries, Sex Distribution, Eye Neoplasms epidemiology, Lymphoma, B-Cell, Marginal Zone epidemiology, Lymphoma, Follicular epidemiology, Lymphoma, Large B-Cell, Diffuse epidemiology
- Abstract
Background: Ophthalmic lymphoma (OL) is the most common orbital tumour, particularly in older individuals. Little is known about the epidemiology and geographic distribution of OL in Canada. Descriptive demographic statistics are an important first step in understanding OL burden and are necessary to inform comprehensive national cancer prevention programmes., Methods: We determined patterns of incidence and geographical distribution of the three major subtypes of OL: extranodal marginal zone B cell lymphoma, follicular lymphoma (FL) and diffuse large B cell lymphoma. Here, we used cases that were diagnosed during 1992-2010 using two independent population-based cancer registries, the Canadian Cancer Registry and Le Registre Québécois du Cancer (LRQC)., Results: The OL mean annual age-standardised incidence rate for 1992-2010 was 0.65 cases per million people per year with an average annual increase in the incidence rate of 4.5% per year. The mean age of diagnosis was 65 years. OL incidence rate was the highest in the cities located along the heavily industrialised Strait of Georgia in British Columbia., Conclusions: Our data on patient age, sex and temporal trends showed similarities with data reported in the USA and Denmark. Additional studies are needed to determine whether the observed increase in OL incidence is genuine or spurious., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2019. No commercial re-use. See rights and permissions. Published by BMJ.)
- Published
- 2020
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38. Incidence trends of conjunctival malignant melanoma in Canada.
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Ghazawi FM, Darwich R, Le M, Jfri A, Rahme E, Burnier JV, Sasseville D, Burnier MN Jr, and Litvinov IV
- Subjects
- Adult, Age Distribution, Aged, Canada epidemiology, Female, Humans, Incidence, Male, Middle Aged, Registries, Sex Distribution, Conjunctival Neoplasms epidemiology, Melanoma epidemiology
- Abstract
Background: Melanoma is the most common primary malignancy of the eye in adults. While the epidemiology of uveal melanoma has recently been described in Canada, little is known about the epidemiology and geographic distribution of patients with conjunctival melanoma (CM) in Canada., Methods: We conducted a population-based study of CM incidence across all Canadian provinces and territories during 1992-2010 using two independent population-based registries., Results: 190 patients were diagnosed with CM in Canada from 1992 to 2010. 55.3 % of these patients were men. The mean annual incidence rate of CM in Canada was 0.32 cases per million individuals (0.35 and 0.29 cases per million individuals for men and women, respectively). The incidence rates for Canadian provinces demonstrated that the eastern provinces of Nova Scotia and New Brunswick had higher age-adjusted incidence rates than the national average, with rates of 0.52 and 0.47 cases per million individuals per year, respectively., Conclusions: This analysis demonstrates novel variations in CM incidence rates between different Canadian provinces. These results taken together with the data reported from the USA confirm the North-to-South geographic gradient of increasing CM incidence. This research highlights that the epidemiology of CM in North America is comparable to that of cutaneous malignant melanoma in contrast to the trends for uveal melanoma distribution., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2020. No commercial re-use. See rights and permissions. Published by BMJ.)
- Published
- 2020
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39. Uveal melanoma incidence trends in Canada: a national comprehensive population-based study.
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Ghazawi FM, Darwich R, Le M, Rahme E, Zubarev A, Moreau L, Burnier JV, Sasseville D, Burnier MN, and Litvinov IV
- Subjects
- Adolescent, Adult, Age Distribution, Aged, Aged, 80 and over, Canada epidemiology, Child, Child, Preschool, Female, Geography, Humans, Incidence, Infant, Infant, Newborn, Male, Melanoma pathology, Middle Aged, Population Surveillance, Registries, Sex Distribution, Uveal Neoplasms pathology, Melanoma epidemiology, Uveal Neoplasms epidemiology
- Abstract
Background: In the developed countries, uveal melanoma is the most common primary intraocular malignancy in adults. Little is known about the epidemiological and geographical distribution of uveal melanoma in Canada., Methods: To determine the incidence patterns and geographical distribution of uveal melanoma cases in Canada, we conducted the first comprehensive, population-based national study of this malignancy across all Canadian provinces and territories during 1992-2010 years. We examined two independent population-based registries: the Canadian Cancer Registry and Le Registre Québécois du Cancer using corresponding International Classification of Diseases for Oncology-3rd edition codes for all histological subtypes of uveal melanoma., Results: We report that 2215 patients were diagnosed with uveal melanoma, of which 52.1% were males. The average -annual incidence rate of uveal melanoma in Canada was 3.75 cases per million individuals per year (95% CI 3.60 to 3.91). Overall, we report a steady increase in uveal melanoma incidence with an annual increase of 0.074 cases per million individuals per year. Significant differences in the incidence rates of uveal melanoma between Canadian provinces and territories were noted, where the highest crude incidence was in British Columbia and Saskatchewan with rates of 6.38 and 5.47 cases per million individuals per year, respectively., Conclusions: This work, for the first time, defines the disease burden of uveal melanoma in Canada and highlights important longitudinal, geographical and spatial differences in the distribution of uveal melanoma in Canada., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2019. No commercial re-use. See rights and permissions. Published by BMJ.)
- Published
- 2019
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40. Impact of surgical case order on epiretinal membrane peeling surgery.
- Author
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Alshareef RA, Dan A, Chaudhry Z, Darwich R, and Kapusta MA
- Subjects
- Aged, Case-Control Studies, Epiretinal Membrane diagnosis, Female, Follow-Up Studies, Humans, Incidence, Male, Quebec epidemiology, Retrospective Studies, Tomography, Optical Coherence, Basement Membrane surgery, Epiretinal Membrane surgery, Postoperative Complications epidemiology, Visual Acuity, Vitrectomy methods
- Abstract
Objective: To determine whether surgical warm-up affects epiretinal membrane (ERM) peeling complication rates and surgical case times., Setting: Jewish General Hospital, Montreal, QC, Canada., Design: Retrospective case-control study., Methods: We assessed consecutive patients who underwent pars plana vitrectomy for ERM peel (macular pucker) by one surgeon at the Jewish General Hospital from January 2006 until March 2016. Cases evaluated were sequential ERM peels performed as the first 2 surgeries of the day. The first case of the day was considered the "warm-up" and the second case was the "post-warm-up." Baseline demographics, pre-operative characteristics, perioperative and postoperative best-corrected visual acuity (BCVA) at 2 months and 6 months, as well as postoperative complications are described. Results were analyzed using the χ
2 test, t test, and Fischer's exact test. Regression models were used to identify any predictors of postoperative BCVA., Results: The study reviewed 108 patients. The warm-up group was compared with the post-warm-up group, and there was no significant difference between the mean pre-operative BCVA and the post-operative BCVA at 2 and 6 months. ERM peeling surgery complication rates were not statistically different between the warm-up cases and the post-warm-up cases. There was a tendency for performing complex surgeries that needed phaco procedures in post-warm-up cases (13% vs 2%, p = 0.03). Analysis of simple ERM peeling procedures (with no concomitant phaco procedures) showed no statistically significant tendencies for any of the groups to go beyond the 60 minutes allocated for the surgery (25.4% vs 20.0%, p = 0.27)., Conclusion: Warming-up does not influence the rate of postoperative complications or the postoperative BCVA in patients undergoing ERM peels. The strongest predictor of post-operative BCVA was pre-operative BCVA., (Copyright © 2018. Published by Elsevier Inc.)- Published
- 2019
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41. Retinoblastoma Incidence Trends in Canada: A National Comprehensive Population-Based Study.
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Darwich R, Ghazawi FM, Rahme E, Alghazawi N, Burnier JV, Sasseville D, Burnier MN, and Litvinov IV
- Subjects
- Age Factors, Canada epidemiology, Child, Child, Preschool, Female, Follow-Up Studies, Humans, Incidence, Male, Retrospective Studies, Sex Factors, Population Surveillance, Registries, Retinal Neoplasms epidemiology, Retinoblastoma epidemiology
- Abstract
Purpose: To determine the incidence rates and geographic distribution of retinoblastoma in Canada to aid cancer control programs., Methods: Patients with retinoblastoma whose data were available from the Canadian Cancer Registry (CCR) and Le Registre Québécois du Cancer (LRQC) were studied. Using third edition International Classification of Diseases for Oncology (ICD-O) codes, the authors examined the incidence rates and geographic distribution of patients with retinoblastoma between 1992 and 2010. Patient data including sex, age, and laterality of the retinoblastoma were analyzed., Results: Between 1992 and 2010 in Canada, the average annual incidence rate of retinoblastoma was 11.58 cases per 1 million children younger than 5 years (95% CI [confidence interval]: 10.48 to 12.76). The incidence rate was stable over time, with an average age at diagnosis of 2.30 ± 6.85 years and no gender predilection. The laterality of the reported cases was 81.48% for uni-lateral cases and 18.52% for bilateral cases. Provincially, Nova Scotia had twice the national average and the highest incidence rates of retinoblastoma across the Canadian provinces., Conclusions: This is the first study to define the disease burden of retinoblastoma and to highlight important longitudinal, geographic, and spatial differences in the distribution of retinoblastoma in Canada between 1992 and 2010. The results of this study indicate continuity of clinical trends between Canada, the United States, and other developed countries. [J Pediatr Ophthalmol Strabismus. 2019;56(2):124-130.]., (Copyright 2019, SLACK Incorporated.)
- Published
- 2019
- Full Text
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42. Cutaneous malignant melanoma incidence and mortality trends in Canada: A comprehensive population-based study.
- Author
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Ghazawi FM, Cyr J, Darwich R, Le M, Rahme E, Moreau L, Netchiporouk E, Zubarev A, Roshdy O, Glassman SJ, Sasseville D, and Litvinov IV
- Subjects
- Adult, Age Distribution, Aged, Canada epidemiology, Disease-Free Survival, Female, Health Surveys, Humans, Incidence, Male, Melanoma diagnosis, Melanoma therapy, Middle Aged, Neoplasm Invasiveness pathology, Neoplasm Staging, Prognosis, Sex Distribution, Skin Neoplasms diagnosis, Skin Neoplasms therapy, Survival Analysis, Melanoma, Cutaneous Malignant, Melanoma epidemiology, Registries, Skin Neoplasms epidemiology
- Abstract
Background: The incidence of cutaneous malignant melanoma (CMM) is on the rise in many parts of the world. However, there is limited knowledge on the epidemiology of CMM in Canada., Objective: To conduct a comprehensive population-based study of CMM in Canada., Methods: We examined patient clinical and pathologic characteristics as well as the incidence and mortality trends of CMM in Canada using 3 independent population-based registries., Results: In total, 72,565 Canadian patients were given CMM diagnoses during 1992-2010; 47.5% were women. Average age at the time of diagnosis was 56.5 years for women and 60.4 years for men. We report a steady increase in CMM incidence and mortality rates in both sexes. The overall incidence rate of CMM in Canada was 12.29 cases/100,000 person-years. We also report important differences in the incidence and mortality rates between Canadian provinces and territories; the highest incidence of this cancer was documented in Nova Scotia and Prince Edward Island., Limitations: Data on race, clinical disease stage, and Breslow depth of CMM was not available., Conclusion: This study, for the first time, defines the disease burden of CMM in Canada and highlights important longitudinal, geographic, and spatial differences in the distribution of CMM in this country., (Copyright © 2018 American Academy of Dermatology, Inc. Published by Elsevier Inc. All rights reserved.)
- Published
- 2019
- Full Text
- View/download PDF
43. KLF13 is a genetic modifier of the Holt-Oram syndrome gene TBX5.
- Author
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Darwich R, Li W, Yamak A, Komati H, Andelfinger G, Sun K, and Nemer M
- Subjects
- Abnormalities, Multiple metabolism, Abnormalities, Multiple pathology, Animals, Cell Cycle Proteins metabolism, Disease Models, Animal, Gene Expression Regulation, Heart Atria pathology, Heart Defects, Congenital metabolism, Heart Defects, Congenital pathology, Heart Septal Defects, Atrial metabolism, Heart Septal Defects, Atrial pathology, Heart Ventricles metabolism, Heart Ventricles pathology, Heterozygote, Humans, Kruppel-Like Transcription Factors metabolism, Lower Extremity Deformities, Congenital metabolism, Lower Extremity Deformities, Congenital pathology, Mice, Mutation, Protein Binding, Protein Domains genetics, Protein Interaction Maps genetics, Repressor Proteins metabolism, T-Box Domain Proteins metabolism, Transcriptional Activation genetics, Upper Extremity Deformities, Congenital metabolism, Upper Extremity Deformities, Congenital pathology, Abnormalities, Multiple genetics, Cell Cycle Proteins genetics, Heart Atria metabolism, Heart Defects, Congenital genetics, Heart Septal Defects, Atrial genetics, Kruppel-Like Transcription Factors genetics, Lower Extremity Deformities, Congenital genetics, Repressor Proteins genetics, T-Box Domain Proteins genetics, Upper Extremity Deformities, Congenital genetics
- Abstract
TBX5, a member of the T-box family of transcription factors, is a dosage sensitive regulator of heart development. Mutations in TBX5 are responsible for Holt-Oram Syndrome, an autosomal dominant disease with variable and partially penetrant cardiac defects suggestive of the existence of genetic and environmental modifiers. KLF13, a member of the Krüppel-like family of zinc finger proteins is co-expressed with TBX5 in several cardiac cells including atrial cardiomyocytes and cells of the interatrial septum. We report that KLF13 interacts physically and functionally with TBX5 to synergistically activate transcription of cardiac genes. We show that TBX5 contacts KLF13 via its T-domain and find that several disease-causing mutations therein have decreased KLF13 interaction. Whereas Klf13 heterozygote mice have no detectable cardiac defects, loss of a Klf13 allele in Tbx5 heterozygote mice significantly increases the penetrance of TBX5-dependent cardiac abnormalities including atrial, atrial-ventricular and ventricular septal defects. The results reveal for the first time combinatorial interaction between a T-box protein and a KLF family member and its importance for heart and possibly other organ development. The data also suggest that, in human, KLF13 may be a genetic modifier of the Holt-Oram Syndrome gene TBX5., (© The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)
- Published
- 2017
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44. Nuclear Receptor-Like Structure and Interaction of Congenital Heart Disease-Associated Factors GATA4 and NKX2-5.
- Author
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Kinnunen S, Välimäki M, Tölli M, Wohlfahrt G, Darwich R, Komati H, Nemer M, and Ruskoaho H
- Subjects
- Animals, COS Cells, Chlorocebus aethiops, DNA genetics, GATA4 Transcription Factor genetics, Heart Defects, Congenital genetics, Homeobox Protein Nkx-2.5, Homeodomain Proteins genetics, Mice, Protein Binding, Protein Structure, Tertiary, Receptors, Cytoplasmic and Nuclear genetics, Transcription Factors genetics, Zinc Fingers, DNA metabolism, GATA4 Transcription Factor metabolism, Heart Defects, Congenital metabolism, Homeodomain Proteins metabolism, Models, Biological, Mutation, Receptors, Cytoplasmic and Nuclear metabolism, Transcription Factors metabolism
- Abstract
Aims: Transcription factor GATA4 is a dosage sensitive regulator of heart development and alterations in its level or activity lead to congenital heart disease (CHD). GATA4 has also been implicated in cardiac regeneration and repair. GATA4 action involves combinatorial interaction with other cofactors such as NKX2-5, another critical cardiac regulator whose mutations also cause CHD. Despite its critical importance to the heart and its evolutionary conservation across species, the structural basis of the GATA4-NKX2-5 interaction remains incompletely understood., Methods and Results: A homology model was constructed and used to identify surface amino acids important for the interaction of GATA4 and NKX2-5. These residues were subjected to site-directed mutagenesis, and the mutant proteins were characterized for their ability to bind DNA and to physically and functionally interact with NKX2-5. The studies identify 5 highly conserved amino acids in the second zinc finger (N272, R283, Q274, K299) and its C-terminal extension (R319) that are critical for physical and functional interaction with the third alpha helix of NKX2-5 homeodomain. Integration of the experimental data with computational modeling suggests that the structural arrangement of the zinc finger-homeodomain resembles the architecture of the conserved DNA binding domain of nuclear receptors., Conclusions: The results provide novel insight into the structural basis for protein-protein interactions between two important classes of transcription factors. The model proposed will help to elucidate the molecular basis for disease causing mutations in GATA4 and NKX2-5 and may be relevant to other members of the GATA and NK classes of transcription factors.
- Published
- 2015
- Full Text
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45. The disruption of L-carnitine metabolism by aluminum toxicity and oxidative stress promotes dyslipidemia in human astrocytic and hepatic cells.
- Author
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Lemire J, Mailloux R, Darwich R, Auger C, and Appanna VD
- Subjects
- Cell Line, Tumor, Hep G2 Cells, Humans, Hydrogen Peroxide toxicity, Ketoglutaric Acids metabolism, Lipid Metabolism drug effects, Reactive Oxygen Species metabolism, gamma-Butyrobetaine Dioxygenase metabolism, Aluminum toxicity, Astrocytes metabolism, Carnitine metabolism, Dyslipidemias chemically induced, Hepatocytes metabolism, Oxidative Stress drug effects
- Abstract
L-Carnitine is a critical metabolite indispensable for the metabolism of lipids as it facilitates fatty acid transport into the mitochondrion where β-oxidation occurs. Human astrocytes (CCF-STTG1 cells) and hepatocytes (HepG2 cells) exposed to aluminum (Al) and hydrogen peroxide (H₂O₂), were characterized with lower levels of L-carnitine, diminished β-oxidation, and increased lipid accumulation compared to the controls. γ-Butyrobetainealdehyde dehydrogenase (BADH) and butyrobetaine dioxygenase (BBDOX), two key enzymes mediating the biogenesis of L-carnitine, were sharply reduced during Al and H₂O₂ challenge. Exposure of the Al and H₂O₂-treated cells to α-ketoglutarate (KG), led to the recovery of L-carnitine production with the concomitant reduction in ROS levels. It appears that the channeling of KG to combat oxidative stress results in decreased L-carnitine synthesis, an event that contributes to the dyslipidemia observed during Al and H₂O₂ insults in these mammalian cells. Hence, KG may help alleviate pathological conditions induced by oxidative stress., (Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.)
- Published
- 2011
- Full Text
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46. Cervical carotid pseudoaneurysm: A carotid artery stenting complication.
- Author
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Raso J, Darwich R, Ornellas C, and Cariri G
- Abstract
Background: As carotid artery stenting becomes increasingly used, more complications are likely to occur. We present a case of Staphylococcus septicemia and pseudoaneurysm arising in the neck portion of the carotid artery after stenting., Case Description: A 51-year-old man was admitted with mild left hemiparesis. CT and MRI showed right hemisphere ischemia. Duplex Scan and MRA showed bilateral severe stenosis of the carotid arteries in the neck. A percutaneous angioplasty with stenting of the left carotid artery was performed. Two weeks after the procedure, he developed fever and swelling in the right leg and shoulder. An abscess, near where the groin had been punctured for the angioplasty was surgically drained. Blood samples were positive for S. aureus. After treatment the patient complained of a painful bulky pulsatile left cervical mass. Duplex scan and MRA showed a pseudoaneurysm of the left carotid artery. We excised the pseudoaneurysm and rebuilt the carotid artery with a saphenous vein graft. The postoperative period was uneventful, and the MRA revealed a patent saphenous graft., Conclusion: Mycotic pseudoaneurysm of the carotid artery is a rare complication of percutaneous angioplasty and stenting. Surgical treatment with saphenous vein graft is the treatment of choice.
- Published
- 2011
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47. The monitoring of nucleotide diphosphate kinase activity by blue native polyacrylamide gel electrophoresis.
- Author
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Mailloux RJ, Darwich R, Lemire J, and Appanna V
- Subjects
- Pseudomonas fluorescens enzymology, Electrophoresis, Polyacrylamide Gel methods, Phosphotransferases metabolism
- Abstract
Nucleoside diphosphate kinase (NDPK) has been shown to play a pivotal role in modulating a plethora of cellular processes. In this study, we report on a blue native (BN) PAGE technique which allows the facile assessment of NDPK activity and expression. The in-gel detection of NDPK relies on the precipitation of formazan at the site of immobilized enzyme activity. This is achieved by coupling the formation of ATP, as a consequence of gamma-phosphate transfer from NTP to ADP, to hexokinase (HK), glucose-6-phosphate dehydrogenase (G6PDH), oxidized nicotinamide adenine dinucleotide phosphate (NADP), phenazine methosulfate (PMS), and iodonitrotetrazolium chloride (INT). 2-D denaturing gel analysis confirmed that the activity bands corresponded to NDPK as indicated by subunit composition. Furthermore, the sensitivity and specificity of this readily accessible procedure was assessed by monitoring the in-gel activity of NDPK using different concentrations of GTP and CTP as well as deoxynucleoside triphosphates. This electrophoretic technique allows the quick and easy detection of NDPK, a housekeeping enzyme crucial to cell survival.
- Published
- 2008
- Full Text
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48. [Clinical and interventional revascularization in the acute ischemic stroke: national opinion].
- Author
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Raffin CN, Fernandes JG, Evaristo EF, Siqueira Neto JI, Friedrich M, Puglia P, and Darwich R
- Subjects
- Acute Disease, Brazil, Clinical Protocols, Humans, Magnetic Resonance Angiography, Societies, Medical, Tomography, X-Ray Computed, Brain Ischemia diagnosis, Brain Ischemia drug therapy, Brain Ischemia surgery, Cerebral Revascularization, Stroke diagnosis, Stroke drug therapy, Stroke surgery, Thrombolytic Therapy, Tissue Plasminogen Activator administration & dosage
- Abstract
The Brazilian Stroke Society constituted a committee composed by specialists from different areas of Brazil that emitted a viewpoint called "National Opinion," considering the interventional procedures and thrombolysis in the treatment of the acute ischemic stroke. This study presents the conclusions of this committee.
- Published
- 2006
- Full Text
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49. [Cerebral Aspergillus abscess in immunocompetent patient].
- Author
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Pianetti Filho G, Pedroso ER, Giannetti AV, and Darwich R
- Subjects
- Adult, Amphotericin B therapeutic use, Antifungal Agents therapeutic use, Aspergillus isolation & purification, Brain Abscess diagnosis, Brain Abscess therapy, Female, Fluconazole therapeutic use, Follow-Up Studies, Humans, Intracranial Aneurysm surgery, Neuroaspergillosis therapy, Tomography, X-Ray Computed, Treatment Outcome, Brain Abscess microbiology, Immunocompetence, Neuroaspergillosis diagnosis, Postoperative Complications microbiology
- Abstract
We report an unusual case of brain aspergillosis with multiple recurrent abscess in a 40 year-old immunocompetent woman, with good therapeutical outcome. The patient presented a subarachnoid hemorrhage caused by a ruptured pericallosal artery aneurysm and was submitted to a craniotomy for aneurysm surgery. Five months later, she developed multiple Aspergillus cerebral abscess. Two craniotomies and amphotericin B became necessary during treatment. Fourteen years later, she is asymptomatic. Treatment of brain aspergillosis abscess implied the combination of both surgical and drug therapy with amphotericin B.
- Published
- 2005
- Full Text
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50. [Brazilian multicenter study of sotalol effectiveness in ventricular arrhythmias].
- Author
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Maia IG, Lorga AM, de Paola AA, Rassi A, Perez AK, Sobral D, Atie J, Gizzi JC, and Darwich R
- Subjects
- Administration, Oral, Adult, Aged, Analysis of Variance, Double-Blind Method, Electrocardiography, Female, Humans, Male, Middle Aged, Prospective Studies, Sotalol administration & dosage, Sotalol pharmacology, Anti-Arrhythmia Agents pharmacology, Anti-Arrhythmia Agents therapeutic use, Arrhythmias, Cardiac drug therapy, Sotalol therapeutic use, Tachycardia, Ventricular drug therapy
- Abstract
Purpose: To evaluate the effects of sotalol in patients with nonsustained ventricular tachyarrhythmia (NSVT)., Methods: Ninety patients were enrolled. Patients were submitted to a double-blind crossover randomized study (placebo x 320 ms/po/d/sotalol; 4 weeks, after a wash-out control period. Holter recordings were performed in control (Ct), placebo (Pb) and drug (Dg) periods. Eligible patients had > 50/h isolated ventricular premature beats (VPB), in control, with or without pairs (P) or nonsustained VT (NSVT; > 3 beats, > 100bpm). Drug efficacy criteria were; > or = 75% reduction in isolated VPB, reduction > or = 90% of P and NSVT. The effects of the Dg were evaluated in the global population, in patients with Chagas' disease, idiopathic arrhythmias and ischemic/hypertensive patients., Results: Differences between control and placebo were NS. Isolated VPB; Dg was effective in 42% (38/90 patients) with a mean of Pb and Dg respectively of 11,770 +/- 13,818 and 1,043 +/- 1,554 (p < 0.001). Pairs: drug was effective in 48% (32/67 patients) with a mean of Pb and Dg respectively of 439 +/- 586 and 27 +/- 52 (p < 0.001). NSVT: drug effectiveness was 53% (19/36 patients) with a mean of Pb and Dg respectively of 445 +/- 1,148 and 2.5 +/- 5.8 (p < 0.102). In patients with Chagas' disease, the reduction in VPB was 33% (13/39 patients), in pairs was 42+ (14/34) and in NSVT was 64% (12/22). In idiopathic patients the reduction of VPB was 53% (17/32 patients), in pairs was 50% (10/20) and in NSVT was 36% (4/11). In ischemic and hypertensive patients the reduction of VPB was 47% (7/15 patients) and 73% in pairs (8/11)., Conclusion: In the present study, sotalol was effective in the control of nonsustained ventricular tachyarrhythmia, with minimal side-effects.
- Published
- 1996
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