34 results on '"L. Tounsi"'
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2. Analyse de la tête du nerf optique par microscope confocal à balayage laser (CSLO) de larges excavations papillaires comparée aux normales
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L. Tounsi, Amel Ouertani, C. Khammari, I. Mili-Boussen, and J. Bouden
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Ophthalmology - Abstract
But. - Comparer les parametres stereometriques obtenus au microscope confocal a balayage laser (CSLO) de larges excavations physiologiques (LEP) a ceux des excavations normales (EN). Materiel et methode. - Nous avons mene une etude prospective incluant 83 yeux (43 patients), repartis en deux groupes en fonction de l'excavation papillaire: groupe EN (n=83 yeux) et groupe LEP (CD ≥ 6/10 e avec asymetrie > 0,2, n = 44 yeux). Un examen ophtalmologique complet avec releve du champ visuel et examen au CSLO (Heidelberg Retina Tomograph) etait realise chez tous les patients. La comparaison des parametres entre les deux groupes a ete realisee a l'aide du test t de Student. Resultats. - L'âge moyen etait respectivement de 46 et de 44 ans dans le groupe EN et le gorupe LEP, et le sex-ratio de 1,26 et de 0,69 (p=0,381). La surface moyenne de la papille etait de 2,07 ± 0,38 dans le groupe EN versus 2,73 ± 0,45 dans le groupe LEP, la surface de l'excavation a 0,52 ± 0,82 vs 1,26 ± 0,30, le volume de l'excavation a 0,14 ± 0,14 vs 0,44 ± 0,16, le rapport C/D a 0,24 ± 0,11 vs 0,46 ± 0,06 avec un p < 0,001 pour tous. La surface de l'ANR etait a 1,56 ± 0,27 vs 1,45 ± 0,27 (p = 0,345) et l'aire de la couche des fibres optiques a 1,43 ± 0,25 vs 1,37 ± 0,29 (p = 0,849). L'epaisseur moyenne de la couche des fibres optiques etait a 0,28 ± 0,05 vs 0,23 ± 0,05 (p
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- 2009
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3. Hybrid-Mode Analysis of High-Tc Thick Superconducting Microwave Circuits on Multilayered Anisotropic Layers
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Mustapha C. E. Yagoub and M. L. Tounsi
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Permittivity ,Superconductivity ,Materials science ,High-temperature superconductivity ,Condensed matter physics ,General Physics and Astronomy ,Conductivity ,Electronic, Optical and Magnetic Materials ,law.invention ,law ,Condensed Matter::Superconductivity ,Electrical and Electronic Engineering ,Anisotropy ,Finite thickness ,Microwave ,Electronic circuit - Abstract
An efficient full-wave algorithm based on spectral domain approach (SDA) is developed for high temperature superconductors (HTS) microwave circuits on multilayered anisotropic substrates. The substrate may consist of arbitrary number of layers whose permittivity and permeability are tensors. The effects of the superconducting material, of finite complex conductivity and finite thickness, are taken into account. Good agreement is shown with regard to published data particularly for circuits having high film-to-substrate thickness ratio.
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- 2008
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4. Dispersion characteristics of multilayered anisotropie microwave circuits independently of the optical axis polarization
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M. L. Tounsi and M. C. E. Yagoub
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Physics ,business.industry ,chemistry.chemical_element ,Basis function ,Polarization (waves) ,Hafnium ,Optical axis ,Optics ,chemistry ,Anisotropy ,Galerkin method ,business ,Microwave ,Electronic circuit - Abstract
In this paper, the spectral-domain approach has been used as an efficient method to investigate the dispersive properties of anisotropic multilayered microwave circuits with arbitrary polarization of the optical axis. The analysis is based on Galerkin's method via an adequate choice of basis functions while the spectral dyadic Green's functions have been derived via a recursive algorithm. The proposed approach was demonstrated through successful comparison with data available in the literature.
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- 2015
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5. FDTD Analysis of Shielded High-T c Microstrip Resonators on Anisotropic Substrates
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O. Madani, M. L. Tounsi, and Mustapha C. E. Yagoub
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Superconductivity ,Materials science ,Physics::Instrumentation and Detectors ,business.industry ,Bandwidth (signal processing) ,Finite-difference time-domain method ,law.invention ,law ,Condensed Matter::Superconductivity ,Shielded cable ,Electromagnetic shielding ,Optoelectronics ,Shielding effect ,Wideband ,business ,Anisotropy - Abstract
An improved FDTD hybrid-mode technique is proposed to analyze shielded high-temperature T c superconducting (HTS) microstrip resonators of arbitrary thickness. The temperature dependence on resonant frequency and bandwidth are investigated assuming an anisotropic dielectric substrate. Variations of resonant frequency with high-T c superconducting thickness and shielding effect are also presented as well as S parameters over wideband.
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- 2013
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6. Hybrid-mode analysis of anisotropic high-Tc superconducting passive microwave circuits on lossy anisotropic dielectric layers
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A. Belguidoum, M. C. E Yagoub, and M. L. Tounsi
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Electromagnetic field ,Superconductivity ,Materials science ,Optics ,business.industry ,Numerical analysis ,Dielectric ,Propagation constant ,business ,Anisotropy ,Microwave ,Monolithic microwave integrated circuit ,Computational physics - Abstract
A computationally efficient full-wave technique is presented to analyze the anisotropic high-T c superconducting passive microwave circuits on lossy anisotropic layers in multilayer configuration. The numerical analysis was carried out by the spectral domain approach using a dyadic Green's functions. Simulated complex propagation constant and quality factor parameters have been successfully compared to both published measured and theoretical results.
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- 2011
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7. [Optic nerve head analysis using the confocal scanning laser ophthalmoscope (CSLO) of big cups versus normal cups]
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A, Ouertani, L, Tounsi, C, Khammari, J, Bouden, and I, Mili-Boussen
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Male ,Ophthalmoscopy ,Microscopy, Confocal ,Ophthalmoscopes ,Optic Disk ,Humans ,Female ,Prospective Studies ,Middle Aged - Abstract
To comparatively evaluate the optic nerve head (ONH) using the confocal scanning laser ophthalmoscope (CSLO) in normal eye subjects (NE) versus big cup (BC) patients.A total of 83 NEs (43 subjects) and 44 BC eyes (22 patients) were evaluated in this prospective study. The ONH was imaged using the CSLO (HRT-II; Heidelberg Engineering, Heidelberg, Germany). Disc area, cup area, rim area, rim volume (horizontal integrated rim volume), cup/disc ratio, and cup volume were evaluated. Additionally, cup depth and retinal nerve fiber layer thickness (RNFL th) and csa (RNFL csa) of the ONH were also measured. These ONH parameters were compared between normal subjects and eyes with a big cup. We used the t test for statistical analysis.The mean age was 46 and 44 years in the NE and BC groups, with a sex ratio of 1.26 and 0.69 (p=0.381), respectively. There was a significant difference in disc area (2.07+/-0.38, 2.73+/-0.45, p0.01), cup area (0.52+/-0.8, 1.26+/-0.3, p0.01), cup volume (0.14+/-0.14, 0.44+/-0.16, p0.01), cup/disc ratio (0.24+/-0.1, 0.69+/-0.1, 0.46+/-0.06, p0.01), Me cup disc (0.24+/-0.1, 0.37+/-0.1, p0.01), rim volume (0.44+/-0.1, 0.34+/-0.09, p0.01), rim area (1.56+/-0.27, 1.45+/-0.27, p=0.345), RNFL th (0.28+/-0.05, 0.23+/-0.05, p0.001) and CSM-0.19+/-0.14,-0.08+/-0.06, p0.001), RNFL csa (1.43+/-0.25, 1.37+/-0.29, p=0.849) in normal vs big cup eyes, respectively.There is correlation between the cup and disc areas. Parameters evaluating the retinal nerve fiber were comparable in the two groups, except the RNFL thickness, which was lower in the BC group. This may be explained by the larger surface of the optic disc in this group.HRT parameters might be part of the criteria favoring the physiologic character of big cups.
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- 2008
8. Immunohistochemical analysis of cellular adhesion molecules (ICAM-1, VCAM-1) and VEGF in fibrovascular membranes of patients with proliferative diabetic retinopathy: preliminary study
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O. Beltaief, R. Zhioua, W. Zbiba, K. Errais, I. Ammous, R. Anane, J. Ben Hamida, L. Tounsi, Taoufik Khalfaoui, Gérard Lizard, A. Ouertani-Meddeb, and D. Colin
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Adult ,Male ,Vascular Endothelial Growth Factor A ,Proliferative vitreoretinopathy ,Pathology ,medicine.medical_specialty ,Aging ,Biopsy ,Vascular Cell Adhesion Molecule-1 ,Cataract Extraction ,chemistry.chemical_compound ,Young Adult ,Reference Values ,Diabetes mellitus ,medicine ,Humans ,VCAM-1 ,Aged ,Diabetic Retinopathy ,Cell adhesion molecule ,business.industry ,Retinal Vessels ,General Medicine ,Diabetic retinopathy ,Middle Aged ,medicine.disease ,Intercellular Adhesion Molecule-1 ,Immunohistochemistry ,eye diseases ,Vascular endothelial growth factor A ,chemistry ,Immunology ,Disease Progression ,Female ,sense organs ,business ,Cell Adhesion Molecules ,Conjunctiva ,Retinopathy - Abstract
Purpose Diabetic fibrovascular membranes are the main pathological changes of proliferative diabetic retinopathy that can cause serious complications leading to blindness. Since the mechanism of fibrovascular membrane development is still unknown, the aim of our study was to identify potential biomarkers for this pathology. To this end, we analyzed the simultaneous expression of ICAM-1, VCAM-1 and VEGF within tissues of diabetic fibrovascular membranes. Patients and methods Fibrovascular membranes were taken from nine diabetic patients with proliferative diabetic retinopathy. The fibrovascular membrane specimens were analyzed by immunohistochemistry to determine ICAM-1, VCAM-1 and VEGF expression. Controls were collected on nine normal conjunctivas removed during senile cataract surgery. Results Coexpression of ICAM-1, VCAM-1 and VEGF was found in most of the diabetic fibrovascular membranes studied. Thus, ICAM-1 was positive in eight of nine membranes (82%), VCAM-1 in seven of nine membranes (78%) and VEGF in all the membranes. Conclusions The substantial overexpression of adhesion molecules ICAM-1, VCAM-1 and of VEGF suggests that these molecules might contribute to the development of fibrovascular membranes in patients with proliferative diabetic retinopathy, and that they could constitute suitable markers of this pathology.
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- 2008
9. Immunohistochemical study of vascular endothelial growth factor (VEGF), tumor suppressor protein (p53) and intercellular adhesion molecule (ICAM-1) in the conjunctiva of diabetic patients
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Amel Ouertani, L. Tounsi, Raja Anane, K. Errais, O. Beltaief, Raja Zhioua, Ghada Mkannez, Sarra Ben Jilani, Taoufik Khalfaoui, and Lidia Kria
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Adult ,Male ,Vascular Endothelial Growth Factor A ,Pathology ,medicine.medical_specialty ,Histology ,Conjunctiva ,Physiology ,chemistry.chemical_compound ,Diabetes mellitus ,medicine ,Humans ,Aged ,ICAM-1 ,Diabetic Retinopathy ,Immunoperoxidase ,business.industry ,Cell Biology ,General Medicine ,Diabetic retinopathy ,Middle Aged ,medicine.disease ,Intercellular adhesion molecule ,Intercellular Adhesion Molecule-1 ,Immunohistochemistry ,eye diseases ,Vascular endothelial growth factor ,medicine.anatomical_structure ,chemistry ,Diabetes Mellitus, Type 2 ,Female ,sense organs ,Anatomy ,Tumor Suppressor Protein p53 ,business ,Retinopathy - Abstract
The expression pattern of VEGF, p53 and ICAM-1 was studied in conjunctiva of diabetic patients with and without retinopathy. All patients underwent a complete ophthalmic examination, including retinal fluorescein angiography. Indirect immunoperoxidase method was performed on 20 eyes of 20 patients with type II diabetes without DR and on 5 eyes of 5 patients with PDR. A control study was performed on 6 normal conjunctiva undertaken during cataract surgery. Immunoreactivity of VEGF, p53 and ICAM-1 was found in epithelial, fibroblast and vascular endothelial cells. For the same duration of diabetes, a strong to moderate or weak immunoreactivity was observed in the conjunctiva of patients without retinopathy. In patients with PDR, the expression was strong for all these proteins. The immunoreactivity was correlated between VEGF, p53 and ICAM-1. In the normal conjunctiva, a weak to negative immunostaining was observed. The presence of these proteins in the conjunctiva of diabetic patients without retinopathy may add new data in the pathogenesis of diabetic retinopathy. Further studies are needed to confirm this hypothesis.
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- 2005
10. [Ocular-orbital complications from radiotherapy. Two case reports and literature review]
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J, Feki, M, Fourati, L, Tounsi, C, Djavanmardi, F, Abbes, A, Sellami, M, Chaabouni, and J, Daoud
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Male ,Mandibular Neoplasms ,Radiotherapy ,Rhabdomyosarcoma ,Blepharoptosis ,Humans ,Orbital Neoplasms ,Female ,Child ,Enophthalmos ,Cataract ,Aged ,Retrospective Studies - Published
- 1998
11. FUZZY SUPERVISED NONLINEAR PID CONTROL OF A CLASS OF UNKNOWN NONLINEAR SYSTEMS
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REKIK, L. TOUNSI, primary and CHTOUROU, MOHAMED, additional
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- 2010
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12. A New Synthesis Method for the Fuzzy Tuning of Non Linear PID Controllers
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L, Tounsi-rekik, primary, R, Chibani, additional, and M, Chtourou, additional
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- 2009
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13. 727 Syndrome de Schöpf-Schultz-Passarge et hydrocystomes eccrines palpébraux, à propos d’un cas tunisien
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W. Zbiba, R. Anane, H. Frikha, L. Tounsi, S. Basarih, I. Ammous Nouri, and Amel Ouertani
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Ophthalmology - Abstract
Introduction Le syndrome de Schopf-Schultz-Passarge est une dysplasie ectodermique hydrotique rare, hereditaire autosomique recessive, Elle est caracterisee par l’association d’une hypodontie, une hypotrichose, une hyperkeratose palmo-plantaire, une onycho-dystrophie, et des hidrocystomes multiples des paupieres. Nous rapportons l’observation d’une patiente tunisienne âgee de 78 ans qui presente le syndrome de Schopf-Schultz Passarge. Materiels et Methodes Patiente âgee de 78 ans qui consulte en ophtalmologie pour de multiples kystes touchant les 4 paupieres. L’interrogatoire retrouve une notion de consanguinite de 1 er degre, une anodentie complete depuis l’enfance et des troubles de la sudation au niveau des mains et des pieds. L’examen dermatologique objective une onycho-dystrophie et confirme le diagnostic de SSSP. L’examen anatomopathologique de certaines lesions palpebrales a montre qu’il s’agissait d’hidrocystomes eccrines. Discussion Les hidorcystomes eccrines sont rarement decrits avec le syndrome de Shopf-Shultz Passarge. Le syndrome de Schopf-Schultz Passarge est plutot associe a des hidrocystomes apocrines. Conclusion Notre observation represente le premier cas tunisien de syndrome de Schopf-Schultz Passarge, remarquable par sa forme complete. Il faut penser a ce syndrome devant des lesions kystiques multiples des paupieres, et savoir que des tumeurs malignes cutanees de sieges variables peuvent apparaitre au cours de l’evolution, d’ou la necessite d’une surveillance reguliere de ces patients.
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- 2009
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14. 765 Dacryolithe du méat lacrymal inférieur : à propos d’un cas
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I. Letaief, L. Tounsi, S. Bassarih, R. Anane Touzri, N. Laaouini, I. Mili Boussen, A. Meddeb Ouertani, and M. Soukah
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Ophthalmology - Abstract
But Rapporter l’observation d’une patiente qui presente un dacryolithe du meat lacrymal inferieur. Materiels et Methodes Nous rapportons l’observation d’une patiente âgee de 35 ans qui consulte pour un larmoiement chronique droit, l’examen trouve un dacryolithe dans le point lacrymal inferieur droit. Le catheterisme des voies lacrymales par le point lacrymal superieur trouve des voies lacrymales impermeables avec un obstacle au niveau du canal lacrymo-nasal. La patiente a ete operee de dacryocystorhinostomie avec ablation du dacryolithe. Les suites operatoires ont ete bonnes avec des voies lacrymales permeables apres 6 mois de recul. Discussion Les lithiases lacrymales constituent 6 a 18 % des etiologies des obstructions des voies lacrymales. A predominance feminine, leur survenue semble etre plus en rapport avec un environnement anatomique et hormonal particulier qu’avec la stagnation des larmes et des debris dans les vois lacrymales. Elles peuvent affecter n’importe quelle partie du systeme lacrymal. Conclusion Bien que de diagnostic facile, le siege meatique des dacryolithes a ete rarement rapporte. C’est ce qui represente l’originalite de cette observation.
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- 2009
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15. 350 Effets de l’âge, de la taille du disque optique et de l’erreur réfractive sur la topographie de la tête du nerf optique dans une population tunisienne normale : une étude par le HRT I
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L. Tounsi, A. Meddeb Ouertani, C. Khammari, W. Zbiba, and J. Bouden Mehrez
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Ophthalmology - Abstract
Objectif Il s’agit de determiner les effets de la variation de l’âge, de la taille du disque optique et de l’erreur refractive sur les donnees topographiques de la tete du nerf optique dans une population tunisienne indemne de toute pathologie generale ou ophtalmologique. Materiels et Methodes C’est une etude qui porte sur 340 yeux de 170 patients, âges de 6 a 74 ans, consultant pour une correction optique entre juillet 2003 a fevrier 2005. Tous les patients ont eu un examen ophtalmologique complet ainsi qu’une imagerie par le confocal scanning laser ophtalmoscope de type HRT I ; software 2.01 (Heidelberg engineering BmbH, Heidelberg, Germany). Nous avons etudie grâce au logiciel statistique SPSS 11 la variabilite des parametres stereometriques de la tete du nerf optique selon l’âge, l’erreur refractive et la taille du disque optique. Discussion Nos sujets se repartissent en 82 hommes et 88 femmes, d’âge moyen 32 ± 20 ans. La surface du disque optique (disc area = DA), variant de 1,006 mm2 a 4,213 mm2, est correlee a tous les autres parametres stereometriques, hormis le volume de l’anneau neuroretinien (Rim volume = RV). Un declin des parametres explorant la couche des fibres nerveuses retiniennes est note au-dela de 50 ans mais il est non statistiquement significatif. Les anomalies de la refraction ne semblent pas influencer les parametres stereometriques de la tete du nerf optique, a l’exception de la myopie forte qui est associee a une surface du DO (DA), de l’excavation (cup area = CA) et de l’anneau neuroretinien (Rim area = RA) plus larges, et a de plus faibles epaisseurs de la couche des fibres nerveuses retiniennes (RNFL thickness et RNFL csa). Conclusion La surface du disque optique est un facteur determinant dans la topographie de la TNO. Il est correle a tous les autres parametres stereometriques. Les parametres explorant la couche des FNR varient peu avec l’âge et semblent diminuer de facon significative chez les myopes forts. Ces donnees devraient etre prises en compte dans l’interpretation de tout examen de la papille par le HRT.
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- 2008
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16. 218 L’analyse de la tête du nerf optique par le Confocal Scanning Laser Ophtalmoscope (CSLO), dans les grandes excavations physiologiques comparée aux yeux normaux
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J. Bouden, L. Tounsi, C. Khammari, A. Ouertani Meddeb, and I. Mili Boussen
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Ophthalmology - Abstract
But Comparer les parametres stereometriques par CSLO de grandes excavations physiologiques (GEP) a ceux des excavations normales (EN). Materiels et Methodes Etude prospective comparant le groupe (1) d’EN (n = 83 yeux) et le groupe (2) avec GEP (n = 44 yeux). L’âge moyen est respectivement de 46 et de 44 ans, et le sex-ratio de 1.26 et 0.69. La methode inclut un examen ophtalmologique complet avec CV, et un examen au CSLO (Heidelberg Retina Tomograph). L’etude statistique a utilise l’Anova et t test. Resultats En comparant les groupes 1 et 2, la surface de la papille est a 2.07 ± 0,38 vs 2.73 ± 0,45, la surface de l’excavation a 0.52 ± 0,82 vs 1.26 ± 0,30, le volume de l’excavation a 0.14 ± 0,14 vs 0.44 ± 0,16, le rapport C/D a 0.24 ± 0,11vs 0.46 ± 0,06 avec un (p Discussion Dans les GEP, la surface de l’excavation est correlee a celle de la papille. Les parametres des fibres visuelles sont comparables dans les 2 groupes. Conclusion Le CSLO aide a differencier les GEP des glaucomes debutants.
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- 2008
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17. 349 Paramètres stéréométriques de la tête du nerf optique dans le glaucome primitif à angle ouvert avéré en comparaison avec les sujets normaux et le glaucome pré-périmétrique : étude par le Heidelberg Retina Tomograph (HRT)
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J. Bouden, W. Zbiba, C. Khammari Chebbi, L. Tounsi, and A. Ouertani Meddeb
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Ophthalmology - Abstract
Introduction Le but de ce travail est de rapporter et de comparer les valeurs des parametres stereometriques de la TNO et des fibres nerveuses retiniennes mesurees par un Confocal Scanning Laser Ophtalmoscope type Heidelberg Retina Tomograph dans une population tunisienne de sujets normaux, de patients atteints de glaucome pre-perimetrique et de glaucomateux averes. Materiels et Methodes L’etude a porte sur 52 yeux de 28 patients normaux, 56 yeux de patients atteints de glaucome pre-perimetrique et 94 yeux de 64 patients glaucomateux averes. Chaque patient a eu un examen ophtalmologique complet, un examen du champ visuel en perimetrie automatisee standard ainsi qu’une imagerie par un Confocal Scanning Laser Ophtalmoscope type HRT I ; software 2.01. L’atteinte glaucomateuse etait classee en debutante, moderee ou severe selon la classification de Hodapp-Parrish-Anderson. L’etude statistique a utilise le logiciel SPSS 11. Discussion La comparaison entre les parametres stereometriques de la TNO et des fibres nerveuses retiniennes entre les sujets normaux et les sujets glaucomateux montre qu’il existe des differences statistiquement significatives pour tous les parametres etudies. Seule la Height Variation Contour n’est pas statistiquement differente entre les sujets normaux et les glaucomes pre-perimetriques. Il existe des differences significatives des valeurs du Cup Area, Cup Disc Area Ratio, Rim Area, Rim Volume, Mean Retinal Nerve Fiber Layer Thickness et Retinal Nerve Fiber Layer Cross Section Area entre les glaucomes averes et pre-perimetriques. Ce seraient donc les parametres de l’anneau neuroretinien qui s’alterent en premier dans la NOG. Conclusion Le Confocal Scanning Laser Ophtalmoscope type Heidelberg Retina Tomograph est un outil d’exploration tres utile dans le suivi et la prise en charge de la NOG. Toutefois, l’interpretation de cet examen se heurte a la grande variabilite des parametres stereometriques de la TNO et des fibres nerveuses retiniennes. Ainsi, il est essentiel de se baser sur une population de reference et de documenter l’evolution dans le temps de la perte structurale pour tirer le plus grand profit de cet examen.
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- 2008
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18. 367 Apport de l’angiographie en indocyanine dans l’hypertension artérielle maligne
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K. Errais, R. Zhioua, L. Tounsi, Amel Ouertani, I. Mili Boussen, and R. Kamoun
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Ophthalmology ,genetic structures - Abstract
Introduction La presence d’une choroidopathie hypertensive constitue l’un des facteurs de gravite de l’hypertension arterielle systemique (HTA) maligne. Nous nous proposons d’analyser les images d’angiographie au vert d’indocyanine (ICG) liee cette pathologie. Materiels et Methodes Notre etude retrospective concerne les ICG de 7 patients porteurs d’HTA maligne. L’âge moyen des patients etait de 31,3 ans (de 22 a 36 ans) et le sexe ratio etait a 0,3. 5 patients etaient porteurs d’HTA maligne essentielle et 2 patientes avaient un lupus erythemateux dissemine. Resultats On notait a la phase precoce de l’ICG, la presence de multiples territoires d’occlusion vasculaire choroidienne et des lesions hypofluorescentes multiples disseminees a tout le fond de l’œil dans tous les cas ; des defauts de remplissage de veines choroidiennes de grand calibre dans 5 cas et des dilatations des veines choroidiennes dans 3 cas. A la phase tardive, il n’y avait pas de remplissage de colorant des veines occluses, avec aspect « en ombre chinoise ». Discussion Dans notre serie, tous les patients etaient porteurs de modifications circulatoires choroidiennes, temoin d’une choroidopathie hypertensive. Leur presence represente un facteur de gravite dans l’HTA. Ces lesions, observees en ICG, ne sont pas identifiables par d’autres methodes d’exploration. Les occlusions choroidiennes veineuses, qu’elles soient de petit ou de grand calibre, semblent dominer le tableau de cette affection. Conclusion La recherche de choroidopathie hypertensive par ICG systematique est proposee dans la prise en charge des patients avec HTA maligne. Ces resultats restent a confirmer par des etudes a plus large echelle.
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- 2007
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19. 710 Le carcinome basocellulaire des paupières : à propos de 25 cas
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N. Benyounes, R. Zhioua Gmar, R. Anane Touzri, A. Meddeb Ouertani, L. Larghech, C. Khammari, L. Tounsi, L. Kria, and K. Errais
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Ophthalmology - Published
- 2005
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20. Enhanced growth and metabolite production from a novel strain of Porphyridium sp.
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Tounsi L, Ben Hlima H, Derbel H, Duchez D, Gardarin C, Dubessay P, Drira M, Fendri I, Michaud P, and Abdelkafi S
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- Chlorophyll A metabolism, Starch, Photosynthesis, Biomass, Porphyridium genetics, Porphyridium metabolism, Microalgae metabolism
- Abstract
Microalgae are capable of generating numerous metabolites that possess notable biological activities and hold substantial promise for various industrial applications. Nevertheless, the taxonomic diversity of these photosynthetic microorganisms has not received thorough investigation. Using the 18S rRNA encoding gene, a recently discovered strain originating from the Tunisian coast (the governorate of Mahdia) was identified as a member of the Porphyridium genus. The growth response as well as the metabolite accumulation of Porphyridium sp. to different culture media (Pm, F/2, and Hemerick) was investigated over a period of 52 days. The highest biomass production was recorded with Pm medium (2 × 10
7 cell/mL). The apparent growth rates (µ) and the doubling time (Dt ) were about 0.081 day-1 and 12.34 days, respectively. The highest chlorophyll a (0.678 ± 0.005 pg/cell), total carotenoids (0.18 ± 0.003 pg/cell), phycoerythrin (3.88 ± 0.003 pg/cell), and proteins (14.58 ± 0.35 pg/cell) contents were observed with F/2 medium. Cultivating Porphyridium sp. in both F/2 and Hemerick media yielded similar levels of starch accumulation. The Hemerick medium has proven to be the most suitable for the production of lipids (2.23% DW) and exopolysaccharides (5.41 ± 0.56 pg/cell).- Published
- 2024
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21. Microalgae: A Promising Source of Bioactive Phycobiliproteins.
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Tounsi L, Ben Hlima H, Hentati F, Hentati O, Derbel H, Michaud P, and Abdelkafi S
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- Biotechnology, Coloring Agents, Commerce, Phycobiliproteins, Microalgae
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Phycobiliproteins are photosynthetic light-harvesting pigments isolated from microalgae with fluorescent, colorimetric and biological properties, making them a potential commodity in the pharmaceutical, cosmetic and food industries. Hence, improving their metabolic yield is of great interest. In this regard, the present review aimed, first, to provide a detailed and thorough overview of the optimization of culture media elements, as well as various physical parameters, to improve the large-scale manufacturing of such bioactive molecules. The second section of the review offers systematic, deep and detailed data about the current main features of phycobiliproteins. In the ultimate section, the health and nutritional claims related to these bioactive pigments, explaining their noticeable potential for biotechnological uses in various fields, are examined.
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- 2023
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22. Microalgae as feedstock for bioactive polysaccharides.
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Tounsi L, Hentati F, Ben Hlima H, Barkallah M, Smaoui S, Fendri I, Michaud P, and Abdelkafi S
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- Animals, Biofuels, Biotechnology methods, Polysaccharides metabolism, Biomass, Microalgae metabolism
- Abstract
Due to the increase in industrial demand for new biosourced molecules (notably bioactive exopolysaccharides (EPS)), microalgae are gaining popularity because of their nutraceutical potential and benefits health. Such health effects are delivered by specific secondary metabolites, e.g., pigments, exopolysaccharides, polyunsaturated fatty acids, proteins, and glycolipids. These are suitable for the subsequent uses in cosmetic, nutraceutical, pharmaceutical, biofuels, biological waste treatment, animal feed and food fields. In this regard, a special focus has been given in this review to describe the various methods used for extraction and purification of polysaccharides. The second part of the review provides an up-to-date and comprehensive summary of parameters affecting the microalgae growth and insights to maximize the metabolic output by understanding the intricacies of algal development and polysaccharides production. In the ultimate part, the health and nutraceutical claims associated with marine algal bioactive polysaccharides, explaining their noticeable potential for biotechnological applications, are summarized and comprehensively discussed., Competing Interests: Declaration of competing interest 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., (Copyright © 2022. Published by Elsevier B.V.)
- Published
- 2022
- Full Text
- View/download PDF
23. Effect of heavy metals mixture on the growth and physiology of Tetraselmis sp.: Applications to lipid production and bioremediation.
- Author
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Dammak M, Ben Hlima H, Tounsi L, Michaud P, Fendri I, and Abdelkafi S
- Subjects
- Biodegradation, Environmental, Chromium, Cobalt, Lipids, Nickel pharmacology, Chlorophyta, Metals, Heavy
- Abstract
Phycoremediation of heavy metals from contaminated waters by oleaginous microalgae is an eco-friendly and emerging trend. Different concentrations of toxic metals such as nickel (Ni), chromium (Cr) and cobalt (Co) were added in Tetraselmis sp. culture media. Mixture Design was used to model the effect of these metals on cell growth, lipid production and heavy metals removal. Tetraselmis sp. was identified as an outstanding Ni, Cr and Co accumulator with bioconcentration factors of 675.17, 584.9 and 169.81 within binary mixtures (Ni × Cr), (Cr × Co) and (Cr × Co) at 6 mg/L, respectively. Optimization studies showed that the highest cell growth (9.22 × 10
5 cells/mL), lipid content (31% Dry Weight) and metals removal (91%) were obtained with the optimum binary mixture Ni (54.45 %) and Cr (45.45 %). This work presents interesting results revealing the potential of Tetraselmis sp. for nickel removal up to 97 % combined to its potential for biodiesel production., (Copyright © 2022 Elsevier Ltd. All rights reserved.)- Published
- 2022
- Full Text
- View/download PDF
24. Structural Characterization and Rheological and Antioxidant Properties of Novel Polysaccharide from Calcareous Red Seaweed.
- Author
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Hentati F, Tounsi L, Pierre G, Barkallah M, Ursu AV, Ben Hlima H, Desbrières J, Le Cerf D, Fendri I, Michaud P, and Abdelkafi S
- Subjects
- Antioxidants chemistry, Antioxidants pharmacology, Polysaccharides chemistry, Polysaccharides pharmacology, Salts, Sulfates, Rhodophyta chemistry, Seaweed chemistry
- Abstract
A novel sulfated xylogalactan (JASX) was extracted and purified from the rhodophyceae Jania adhaerens . JASX was characterized by chromatography (GC/MS-EI and SEC/MALLS) and spectroscopy (ATR-FTIR and
1 H/13 C NMR) techniques. Results showed that JASX was constituted by repeating units of (→3)-β-d-Gal p -(1,4)-3,6-α-l-AnGal p -(1→)n and (→3)-β-d-Gal p -(1,4)-α-l-Gal p -(1→)n substituted on O -2 and O -3 of the α-(1,4)-l-Gal p units by methoxy and/or sulfate groups but also on O -6 of the β-(1,3)-d-Gal p mainly by β-xylosyl side chains and less by methoxy and/or sulfate groups. The Mw , Mn , Đ, [ η ] and C* of JASX were respectively 600 and 160 kDa, 3.7, 102 mL.g-1 and 7.0 g.L-1 . JASX exhibited pseudoplastic behavior influenced by temperature and monovalent salts and highly correlated to the power-law model and the Arrhenius relationship. JASX presented thixotropic characteristics, a gel-like viscoelastic behavior and a great viscoelasticity character. JASX showed important antioxidant activities, outlining its potential as a natural additive to produce functional foods.- Published
- 2022
- Full Text
- View/download PDF
25. Improvement of Biomass and Phycoerythrin Production by a Strain of Rhodomonas sp. Isolated from the Tunisian Coast of Sidi Mansour.
- Author
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Derbel H, Elleuch J, Tounsi L, Nicolo MS, Rizzo MG, Michaud P, Fendri I, and Abdelkafi S
- Subjects
- Biomass, Calcium Chloride metabolism, Phylogeny, Microalgae metabolism, Phycoerythrin
- Abstract
Microalgae are photoautotrophic microorganisms known as producers of a large variety of metabolites. The taxonomic diversity of these microorganisms has been poorly explored. In this study, a newly isolated strain was identified based on the 18S rRNA encoding gene. The phylogenetic analysis showed that the isolated strain was affiliated with the Rhodomonas genus. This genus has greatly attracted scientific attention according to its capacity to produce a large variety of metabolites, including phycoerythrin. Growth and phycoerythrin production conditions were optimized using a Plackett-Burman design and response surface methodology. An expression profile analysis of the cpeB gene, encoding the beta subunit of phycoerythrin, was performed by qRT-PCR under standard and optimized culture conditions. The optimization process showed that maximum cell abundance was achieved under the following conditions: CaCl
2 = 2.1328 g/L, metal solution = 1 mL/L, pH = 7 and light intensity = 145 μmol photons/m2 /s, whereas maximum phycoerythrin production level occurred when CaCl2 = 1.8467 g/L, metal solution = 1 mL/L, pH = 7 and light intensity = 157 μmol/m2 /s. In agreement, positive transcriptional regulation of the cpeB gene was demonstrated using qRT-PCR. This study showed the successful optimization of abiotic conditions for highest growth and phycoerythrin production, making Rhodomonas sp. suitable for several biotechnological applications.- Published
- 2022
- Full Text
- View/download PDF
26. Structures, Properties and Applications of Alginates.
- Author
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Abka-Khajouei R, Tounsi L, Shahabi N, Patel AK, Abdelkafi S, and Michaud P
- Subjects
- Bacteria, Hexuronic Acids chemistry, Hydrogels, Polymers, Polysaccharides, Alginates chemistry, Phaeophyceae
- Abstract
Alginate is a hydrocolloid from algae, specifically brown algae, which is a group that includes many of the seaweeds, like kelps and an extracellular polymer of some bacteria. Sodium alginate is one of the best-known members of the hydrogel group. The hydrogel is a water-swollen and cross-linked polymeric network produced by the simple reaction of one or more monomers. It has a linear (unbranched) structure based on d-mannuronic and l-guluronic acids. The placement of these monomers depending on the source of its production is alternating, sequential and random. The same arrangement of monomers can affect the physical and chemical properties of this polysaccharide. This polyuronide has a wide range of applications in various industries including the food industry, medicine, tissue engineering, wastewater treatment, the pharmaceutical industry and fuel. It is generally recognized as safe when used in accordance with good manufacturing or feeding practice. This review discusses its application in addition to its structural, physical, and chemical properties.
- Published
- 2022
- Full Text
- View/download PDF
27. Sulfated exopolysaccharides from Porphyridium cruentum: A useful strategy to extend the shelf life of minced beef meat.
- Author
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Ben Hlima H, Smaoui S, Barkallah M, Elhadef K, Tounsi L, Michaud P, Fendri I, and Abdelkafi S
- Subjects
- Animals, Cattle, Food Preservation, Food Preservatives chemistry, Polysaccharides chemistry, Porphyridium chemistry, Red Meat
- Abstract
Sulfated exopolysaccharides (EPS) from Porphyridium cruentum strain were extracted and their antioxidant and anti-bacterial potentials were evaluated based on DPPH free radical, ABTS
•+ radical cation and DNA nicking assays, and against four foodborne pathogenic bacteria, respectively. They showed also interesting functional, foaming and emulsion properties. Moreover, microbiological and chemical effects of EPS at 0.5, 1 and 2% on refrigerated minced beef meat were undertaken. Chemical analyses revealed that the treated meat underwent significant decrease (P < 0.05) of primary and secondary lipid oxidation. By the end of the storage period, exopolysaccharides at 2% reduced the metmyoglobin and carbonyl group accumulation compared to control samples and were more efficient (P < 0.05) against microflora proliferation. Furthermore, two multivariate exploratory techniques namely Principal Component Analysis (PCA) and Hierarchical Cluster Analysis (HCA) were applied successfully to all obtained data describing the main characteristics attributed to refrigerated meat samples. Overall, these findings indicated that EPS from P. cruentum are worthy being developed as functional and bioactive components for the meat industry., (Copyright © 2021 Elsevier B.V. All rights reserved.)- Published
- 2021
- Full Text
- View/download PDF
28. Bioactive Polysaccharides from Seaweeds.
- Author
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Hentati F, Tounsi L, Djomdi D, Pierre G, Delattre C, Ursu AV, Fendri I, Abdelkafi S, and Michaud P
- Subjects
- Carotenoids chemistry, Carotenoids therapeutic use, Humans, Peptides chemistry, Peptides therapeutic use, Xanthophylls chemistry, Xanthophylls therapeutic use, Dietary Supplements, Polysaccharides chemistry, Polysaccharides therapeutic use, Seaweed chemistry
- Abstract
Bioactive compounds with diverse chemical structures play a significant role in disease prevention and maintenance of physiological functions. Due to the increase in industrial demand for new biosourced molecules, several types of biomasses are being exploited for the identification of bioactive metabolites and techno-functional biomolecules that are suitable for the subsequent uses in cosmetic, food and pharmaceutical fields. Among the various biomasses available, macroalgae are gaining popularity because of their potential nutraceutical and health benefits. Such health effects are delivered by specific diterpenes, pigments (fucoxanthin, phycocyanin, and carotenoids), bioactive peptides and polysaccharides. Abundant and recent studies have identified valuable biological activities of native algae polysaccharides, but also of their derivatives, including oligosaccharides and (bio)chemically modified polysaccharides. However, only a few of them can be industrially developed and open up new markets of active molecules, extracts or ingredients. In this respect, the health and nutraceutical claims associated with marine algal bioactive polysaccharides are summarized and comprehensively discussed in this review.
- Published
- 2020
- Full Text
- View/download PDF
29. Effect of adding carob molasses on physical and nutritional quality parameters of sesame paste.
- Author
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Tounsi L, Kchaou H, Chaker F, Bredai S, and Kechaou N
- Abstract
This study focused on the formulation of food products, based on sesame and carob. The possibility of developing blends from sesame paste and carob molasses, using molasses concentrations of 30, 40 and 50%, at 60, 70 and 80°Brix, respectively, has been studied. The blend prepared with 50% carob molasses at 60°Brix was found to be the most acceptable product, according to a sensory acceptability test. Sesame paste, supplemented with carob molasses, was evaluated for physical quality (oil separation, colour and texture) and nutritional composition (moisture, sugar, protein, fat, ash and polyphenols). Physical analysis showed that the addition of carob molasses to sesame paste improved its emulsion stability, changed its colour from beige to brown and modified its texture from fluid to solid. Nutritional analysis proved that mixing sesame paste with carob molasses provided a natural product, characterized by interesting nutritional value (protein: 16.97 g/100 g fry matter, fat: 12.05 g/100 g fry matter and sugar: 9.34 g/100 g fry matter), arising from the constituents of the two ingredients. Thus, the developed blend could offer a promising nutritious and healthy foodstuff to consumers.
- Published
- 2019
- Full Text
- View/download PDF
30. Bilateral macular hemorrhage and retinitis pigmentosa.
- Author
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Ammous I, Mrad I, Boukari M, Zhioua I, Tounsi L, Boussen Mili I, Erraies K, and Zhioua R
- Subjects
- Fluorescein Angiography, Humans, Male, Middle Aged, Retinal Dystrophies diagnostic imaging, Retinal Hemorrhage complications, Retinitis Pigmentosa complications, Vision, Low etiology, Retinal Hemorrhage diagnostic imaging, Retinitis Pigmentosa diagnostic imaging
- Published
- 2016
31. Extracting risk modeling information from medical articles.
- Author
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Deleris LA, Sacaleanu B, and Tounsi L
- Subjects
- Artificial Intelligence, Computer Simulation, Humans, Pattern Recognition, Automated methods, Data Mining methods, Models, Statistical, Natural Language Processing, Periodicals as Topic statistics & numerical data, Proportional Hazards Models, Risk Assessment methods
- Abstract
Risk modeling in healthcare is both ubiquitous and in its infancy. On the one hand, a significant proportion of medical research focuses on determining the factors that influence the incidence, severity and treatment of diseases, which is a form of risk identification. Those studies typically investigate the micro-level of risk modeling, i.e., the existence of dependences between a reduced set of hypothesized (or demonstrated) risk factors and a focus disease or treatment. On the other hand, the macro-level of risk modeling, i.e., articulating how a large number of such risk factors interact to affect diseases and treatments is not widespread, though essential for medical decision support modeling. By exploiting advances in natural language processing, we believe that information contained in unstructured texts such as medical articles could be extracted to facilitate aggregation into macro-level risk models.
- Published
- 2013
32. Immunohistochemical analysis of cellular adhesion molecules (ICAM-1, VCAM-1) and VEGF in fibrovascular membranes of patients with proliferative diabetic retinopathy: preliminary study.
- Author
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Khalfaoui T, Lizard G, Beltaief O, Colin D, Ben Hamida J, Errais K, Ammous I, Zbiba W, Tounsi L, Zhioua R, Anane R, and Ouertani-Meddeb A
- Subjects
- Adult, Aged, Aging, Biopsy, Cataract Extraction, Cell Adhesion Molecules analysis, Conjunctiva pathology, Disease Progression, Female, Humans, Immunohistochemistry methods, Intercellular Adhesion Molecule-1 genetics, Male, Middle Aged, Reference Values, Vascular Cell Adhesion Molecule-1 genetics, Vascular Endothelial Growth Factor A genetics, Young Adult, Diabetic Retinopathy pathology, Intercellular Adhesion Molecule-1 analysis, Retinal Vessels pathology, Vascular Cell Adhesion Molecule-1 analysis, Vascular Endothelial Growth Factor A analysis
- Abstract
Purpose: Diabetic fibrovascular membranes are the main pathological changes of proliferative diabetic retinopathy that can cause serious complications leading to blindness. Since the mechanism of fibrovascular membrane development is still unknown, the aim of our study was to identify potential biomarkers for this pathology. To this end, we analyzed the simultaneous expression of ICAM-1, VCAM-1 and VEGF within tissues of diabetic fibrovascular membranes., Patients and Methods: Fibrovascular membranes were taken from nine diabetic patients with proliferative diabetic retinopathy. The fibrovascular membrane specimens were analyzed by immunohistochemistry to determine ICAM-1, VCAM-1 and VEGF expression. Controls were collected on nine normal conjunctivas removed during senile cataract surgery., Results: Coexpression of ICAM-1, VCAM-1 and VEGF was found in most of the diabetic fibrovascular membranes studied. Thus, ICAM-1 was positive in eight of nine membranes (82%), VCAM-1 in seven of nine membranes (78%) and VEGF in all the membranes., Conclusions: The substantial overexpression of adhesion molecules ICAM-1, VCAM-1 and of VEGF suggests that these molecules might contribute to the development of fibrovascular membranes in patients with proliferative diabetic retinopathy, and that they could constitute suitable markers of this pathology.
- Published
- 2009
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- View/download PDF
33. Immunohistochemical study of vascular endothelial growth factor (VEGF), tumor suppressor protein (p53) and intercellular adhesion molecule (ICAM-1) in the conjunctiva of diabetic patients.
- Author
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Kria L, Khalfaoui T, Mkannez G, Beltaief O, Anane R, Errais K, Tounsi L, Zhioua R, Jilani SB, and Ouertani AM
- Subjects
- Adult, Aged, Diabetic Retinopathy pathology, Female, Humans, Immunohistochemistry, Male, Middle Aged, Conjunctiva pathology, Diabetes Mellitus, Type 2 metabolism, Intercellular Adhesion Molecule-1 metabolism, Tumor Suppressor Protein p53 metabolism, Vascular Endothelial Growth Factor A metabolism
- Abstract
The expression pattern of VEGF, p53 and ICAM-1 was studied in conjunctiva of diabetic patients with and without retinopathy. All patients underwent a complete ophthalmic examination, including retinal fluorescein angiography. Indirect immunoperoxidase method was performed on 20 eyes of 20 patients with type II diabetes without DR and on 5 eyes of 5 patients with PDR. A control study was performed on 6 normal conjunctiva undertaken during cataract surgery. Immunoreactivity of VEGF, p53 and ICAM-1 was found in epithelial, fibroblast and vascular endothelial cells. For the same duration of diabetes, a strong to moderate or weak immunoreactivity was observed in the conjunctiva of patients without retinopathy. In patients with PDR, the expression was strong for all these proteins. The immunoreactivity was correlated between VEGF, p53 and ICAM-1. In the normal conjunctiva, a weak to negative immunostaining was observed. The presence of these proteins in the conjunctiva of diabetic patients without retinopathy may add new data in the pathogenesis of diabetic retinopathy. Further studies are needed to confirm this hypothesis.
- Published
- 2005
- Full Text
- View/download PDF
34. [Ocular-orbital complications from radiotherapy. Two case reports and literature review].
- Author
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Feki J, Fourati M, Tounsi L, Djavanmardi C, Abbes F, Sellami A, Chaabouni M, and Daoud J
- Subjects
- Aged, Child, Female, Humans, Male, Radiotherapy adverse effects, Retrospective Studies, Blepharoptosis etiology, Cataract etiology, Enophthalmos etiology, Mandibular Neoplasms radiotherapy, Orbital Neoplasms radiotherapy, Rhabdomyosarcoma radiotherapy
- Published
- 1998
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