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La maladie à virus corona (COVID-19) peut provoquer de nombreuses manifestations oculaires. Nous rapportons un cas rare de choriorétinopathie séreuse centrale bilatérale, post-infection au COVID-19, chez une femme âgée de 38 ans qui s’est présentée pour un flou visuel bilatéral, 1 mois après l’infection au COVID-19. Elle avait de la fièvre, des frissons, une toux et un essoufflement avec fatigue et elle était positive au COVID-PCR. Pendant son séjour de 10 jours à l’hôpital, elle a reçu une oxygénothérapie, des antibiotiques, de l’héparine et des corticoïdes par voie intraveineuse puis relais par voie orale en ambulatoire. Après sa guérison du COVID-19, la patiente a développé une baisse progressive de l’acuité visuelle des 2 yeux : son acuité visuelle de loin corrigée était de 3/10 dans les 2 yeux, le segment antérieur était normal et le vitré était clair. L’examen du fond d’œil, complété par la tomographie en cohérence optique et l’angiographie à la fluorescéine a montré des décollements séreux rétiniens bilatéraux. L’évolution a été marquée par une amélioration de l’acuité visuelle et une régression des décollements séreux rétiniens. La choriorétinopathie séreuse centrale peut survenir après une infection au COVID-19 en raison de l’administration des corticoïdes et un contrôle ophtalmologique précoce est indispensable pour dépister au plus tôt une atteinte oculaire.

Resume Introduction Le syndrome de blepharophimosis ptosis epicanthus inversus (SBPE) est une anomalie congenitale et hereditaire rare. Il associe des malformations orbito- palpebrales complexes, generant une gene esthetique et fonctionnelle. La prise en charge du SBPE passe par deux etapes : diagnostique et therapeutique. Patients et methodes Nous avons realise une etude descriptive retrospective sur 44 patients (88 paupieres) presentant un syndrome de blepharophimosis-ptosis-epicanthus (SBPE). Dans notre serie, nous avons opte pour une chirurgie en deux temps operatoires dans 28 cas : chirurgie de l’epicanthus- telecanthus suivie de la chirurgie de la ptose palpebrale. Une chirurgie simultanee a ete realisee dans 5 cas. Resultats L’âge moyen lors de la premiere consultation etait de 6 ans (6,1 ± 6,4). L’âge moyen de nos patients au moment de la premiere chirurgie etait de 6,6 ans. La chirurgie de l’epicanthus a ete realisee dans 35 cas. Les deux techniques utilisees pour corriger l’epicanthus etaient une plastie YV dans 30 cas (85,7 %, n = 35) et une plastie YV + double Z dans 5 cas (14,3 %, n = 35). La correction du telecanthus a ete realisee dans le meme temps operatoire par une plicature du TCM dans 31 cas (88,6 %, n = 35) ou une canthopexie transnasale dans 4 cas (11,4 %, n = 35). L’âge moyen de la chirurgie du ptosis etait de 7,23 ans (±6,25) avec des extremes de 8 mois a 27 ans. La chirurgie du ptosis a ete realisee dans 41 cas, dont 3 ont ete operes d’un seul œil (ptosis asymetrique), soit 79 paupieres. La technique utilisee etait une resection du RPS pour 64 paupieres et une suspension au frontal pour 15 paupieres. Conclusion Le SBPE est souvent de diagnostic clinique. La difficulte de prise en charge reside dans sa chirurgie complexe. Il n’y a pas de consensus etabli concernant les techniques chirurgicales ni la sequence operatoire.

Purpose Ocular toxoplasmosis is the most common cause of infectious uveitis worldwide. The diagnosis of ocular toxoplasmosis is primarily clinical when it is a typical presentation.With an atypical presentation in the fundus, parasitological diagnosis is a decisive contribution, as well as multimodal imaging. The aim of this study was to investigate vitreal, retinal, and choroidal morphologic changes in active and scarred toxoplasmosis lesions using swept source optical coherence tomography. To our knowledge, it is the first study in Tunisia which describes with precision the retinochoroidal lesions caused by Toxoplasma Gondi by means of the optical coherence tomography (OCT). Methods A retrospective analysis of fifteen patients diagnosed with ocular toxoplasmosis was conducted. The patients were examined at ophthalmology service of Farhat Hached Hospital in Sousse Tunisia between January 2002 and December 2019. Complete ophthalmologic examination including best-corrected visual acuity, slit lamp biomicroscopy, dilated biomicroscopic and fundus examinations, colour fundus photography as well as fluorescein angiography and OCT were done at the initial visit and during follow-up. Result In the acute phase, thickening, hyper-reflectivity of the neurosensory retina, posterior shading, bumping of the RPE, hyporeflectivity and thickening of choroid were found in 86,6% of patients. During follow-up, neurosensory retinal layers thinning and disorganization, interrupting ofthe ellipsoid zone (EZ), and RPE hyper reflective were noticed in 73% of patients. The choroid became thin and more hyperreflective in 73% of patients. Multiple hyperreflective dots in the vitreous cavity and posterior hyaloid thickening were demonstrated in the acute phase in 60% of patients, with complete resolution and detachment of the posterior hyaloid in the scarred lesions. Conclusion The SS-OCT is an important adjunctive imaging modality in the diagnosis and follow-up of patients with ocular toxoplasmosis., Highlights • Ocular toxoplasmosis is the most common cause of infectious uveitis worldwide. • The introduction of SD-OCT has enabled imaging with greater resolution, wider sampling area, and improved image registration. • The active retinochoroiditis lesion shows thickening with hyper reflectivity of the internal layers of the retina. • The retinochoroidal scar shows retinal atrophy, interruption of the IS/OS line, sometimes subretinal fibrosis.

Introduction Diabetic retinopathy (DR) increases the risk of blindness by 25 times. Advanced researchs are justified for better management, leading to the role of Optical Coherence Tomography-Angiography (OCT-A), a new non-invasive imaging technique exploring retinal vascularization. Our purpose is to identify microvascular macular anomalies of DR on OCT-A with qualitative and quantitative evaluation of their impact on retinal vascularization. Patients and methods This is a descriptive cross-sectional study where 120 eyes of 66 diabetic patients were enrolled. All patients were diabetic and went through OCT-A imaging. Results Microanevrysms were identified in both superficial capillary plexus (SCP) and deep capillary plexus (DCP) where they were more frequently visualized. Macular edema was present in 16,7% of cases in the SCP, and in 30% in DCP. Edema spaces were more frequently present in DCP (p, Highlights • Retinal microvascular abnormalities on OCT-A are observed in diabetic retinopathy and are proportional to its severity. • Deep capillary plexus was more severely affected than superficial capillary plexus. • The assessment of macular ischemia could be based on the identification of areas of vascular rarefaction. • Quantitative assessment of vascular density and the study of the foveal avascular zone can assess the macular ischemia

Introduction Cat scratch disease (CSD) is a ubiquitous infectious disease caused by a Gram-negative intracellular bacillus, Bartonella henselae. Neuroretinitis is a classical but rare manifestation of CSD. Case presentation A 20-year-old woman presented with a 5-day-history of reduced vision in the left eye (LE). Two weeks before eye symptoms, she complained from fever, fatigue and arthromyalgia which resolved spontaneously. In the LE, visual acuity (VA) was 7/10, fundus photography showed optic disc edema with macular exudates arranged in incomplete macular star. Serologic test for Bartonella henselae using indirect immunofluorescent assay (IFA) was highly positive (1:2560 UI/L) for immunoglobulin G (Ig G). The diagnosis of CSD associated neuroretinitis has been made and the patient was treated with doxycycline, rifampicin and oral prednisolone. Twelve months after the end of therapy, VA was 10/10, fundus photography and Macular OCT were normal. Discussion In CSD, neuroretinitis occurs 2–3 weeks after systemic symptoms. The clinical features of CSD are not specific hence the need for bacteriological diagnosis which is based mainly on serologic testing by the detection of Ig G and Ig M by IFA or ELISA. The treatment of CSD-associated neuroretinitis is not standardized. Antibiotics active against intracellular bacteria, with or without systemic corticosteroids, should be prescribed especially in severe cases. The outcome of Bartonella henslae neuroretinitis is usually favourable. Conclusion Despite rarely reported in Tunisia, CSD should be considered in patients with presence of typical neuroretinitis with macular star and of a history of contact with cats., Highlights • Cat scratch disease is usually a self-limited lymphadenitis. • Neuroretinitis is a rare but classic manifestation of cat scratch disease. • Neuroretinitis occurs in 1–2% of patients with cat scratch disease. • Diagnosis confirmation is based on serologic testing. • The prognosis is usually good.

Background Many studies suggest the existence of an alteration of the retinal hemoperfusion in primary open-angle glaucoma. The OCT-A is a novel technique that allows to provide information on retinal microcirculation in a non-invasive way, thus it represents a possible imaging target for the early diagnosis and follow-up of glaucoma. The aim of our work is to evaluate the contribution of vascular parameters provided by OCT-A and their diagnostic abilities in the different stages of primary open-angle glaucoma. Method This is a prospective cross-sectional study involving 200 eyes of control subjects and 250 eyes of glaucomatous subjects divided into early glaucoma, moderate glaucoma and advanced glaucoma subgroups. They were assessed for MD, LV by visual field, RNFL and GCC thickness by SS-OCT papillary and macular vascular densities by SS-OCT A. Results OCT-A vessel densities determined in the optic nerve head, in the peripapillary and in the macular regions were significantly lower in glaucomatous eyes. Among the vascular parameters studied the whole image vascular density showed the best diagnostic ability in the discrimination between glaucomatous eyes and healthy eyes with an AUC of 0.949. Nevertheless, the diagnostic ability of vascular parameters remains lower than of the structural parameters RNFL (AUC: 0.981). A significant correlation was found between structural, functional and vascular parameters with r, Highlights • OCT-A vascular density parameters exploring the macular and papillary regions are decreased in primary open-angle glaucoma. • Disc and macular vessel density parameters have excellent diagnostic abilities in diagnosing glaucomatous eyes. • A correlation is shown between functional, structural, and vascular parameters. • The non-linear quadratic model better describes the relationship between structural, functional, and vascular parameters.

Introduction Optic nerve avulsion is a traumatic disinsertion of optic nerve fibres from the globe at the level of the lamina cribrosa. It is an uncommon and severe complication of blunt ocular trauma. Case presentation We report the case of a 15 years old male presented to the emergency department after being kicked by a horse. Initial ophthalmologic examination of the left eye (LE), exhibited eyelid hematoma, subconjunctival hemorrhage, VA was limited to light perception and there was a left relative afferent pupillary defect. Dilated fundus examination of the LE revealed an extensive vitreous and preretinal hemorrhage overlaying the optic disc and retina edema.The diagnosis of LE optic nerve head avulsion (ONA) was made. Five years after the accident, VA of LE detecting hand motion, fundus examination revealed a superior dragging of the optic disc, fibroglial scarring, retinal vessel narrowing and retinal epithelium hyperplasia. Clinical discussion In case of ONA, the avulsion can be missed initially due to vitreous and retinal hemorrhage overlaying the optic nerve, in such cases multimodal imaging can be a useful tool to the diagnosis and to evaluate associated ocular damage. Healing process of the avulsed optic nerve is characterized by the development of fibroglial proliferation. Visual outcome is poor and the final visual acuity range from light perception or no light perception in total ONA. Conclusion Optic head nerve avulsion is a rare and severe disease and initial diagnosis is challenging due to associated media opacities. The prognosis is poor and the injury leads to permanent visual impairment., Highlights • Optic nerve avulsion is rare and serious complication of blunt ocular trauma. • Domestic, work related and sport related accidents are incriminated. • Diagnosis is challenging because of media opacities associated. • The prognosis is poor. • To date, there is no efficient treatment.

Introduction Retinal vasoproliférative tumors (VPTs) have been reported as uncommon complications of intermediate Uveitis. Case description A patient consulted for a gradually decreased vision in the right eye (RE). The examination of the RE found a corrected visual acuity at 20/100 with normal eye pressure measured. The anterior segment was deep and quiet and 2+ vitreous haze was found. Funduscopy showed a VPT. Retinal fluorescein angiography of the RE revealed macular cystoid edema also objectified by the Optical Coherence Tomography (OCT). Intermediate Uveitis was considered idiopathic. The patient received a cryoapplication and was put on oral corticosteroid therapy with improvement of visual acuity and a regress of both vitreous inflammation and cystoid macular edema. Conclusion The association of a VPT with intermediate uveitis represents a real diagnostic and therapeutic challenge and imposes rigorous care and monitoring strategy combining internist and ophthalmologist., Highlights • Retinal vasoproliferative tumors (VPTs) have been reported as uncommon complications of intermediate Uveitis. • The presence of active intermediate uveitis accompanied by VPTs suggests the need for an aggressive uveitis treatment. • The causative process underlying the development of VPT in eyes with intermediate Uveitis remains unknown. • We speculate in this case report a pathogenic relationship of this long-standing inflammation to the vascular tumor.

Resume Objectifs Evaluer l’impact du traitement antiglaucomateux et de la pathologie de surface oculaire (PSO) sur la qualite de vie (QdV) chez les patients glaucomateux suivis au CHU Farhat Hached de Sousse (Tunisie). Materiel et methodes Etude transversale incluant 120 patients suivis pour Glaucome primitif a angle ouvert (GPAO). Tous les patients ont repondu a la version arabe du National Eye Institut-Visual Field Questionnaire 25 (NEI-VFQ 25). La qualite de vie etait quantifiee en termes de scores et correlee aux caracteristiques du traitement antiglaucomateux et a l’etat de la surface oculaire. Resultats Nous avons etudie 120 patients. Le nombre moyen de molecules et de gouttes instillees etait respectivement de 1,95 (1–4) et de 2,69 (1–7). Au total, 66,7 % des patients rapportaient des effets indesirables du traitement. A l’examen, un syndrome sec modere ou severe etait releve chez 90 % des patients. Au total, 16,7 % des patients avaient une keratite ponctuee superficielle. Le nombre de gouttes instillees par jour, l’utilisation de la brimonidine ou des inhibiteurs de l’anhydrase carbonique (IAC) per os et la presence d’une PSO avaient un impact negatif sur les scores du NEI-VFQ 25. Conclusions Le traitement antiglaucomateux et l’atteinte de la surface oculaire sont deux facteurs influencant la QDV des patients glaucomateux et sur lesquels l’ophtalmologiste peut agir en optimisant le traitement et en examinant regulierement la surface oculaire des patients glaucomateux.

The aim of the present paper is to derive the exact distribution and the corresponding moment function of the product $$P:=X_{1}X_{2}$$ when $$X_{1}$$ and $$X_{2}$$ are distributed according to a bivariate beta distribution. We also give approximation for this distribution and show its robustness.

Resume Objectifs Evaluer la qualite de vie chez les patients glaucomateux suivis au CHU Farhat Hached de Sousse et identifier les facteurs sociodemographiques et cliniques affectant potentiellement la qualite de vie. Materiel et methodes Etude transversale incluant 120 patients suivis pour glaucome primitif a angle ouvert (GPAO). Tous les patients ont repondu a la version arabe du National Eye Institute-Visual Field Questionnaire 25 (NEI-VFQ 25). La qualite de vie etait quantifiee en termes de scores et correlee aux facteurs sociodemographiques et cliniques. Resultats Nous avons etudie 120 patients. L’âge moyen etait de 62,38 ± 10,68 ans. Le score moyen global (SMG) de la qualite de vie de nos patients allait de 23,71 a 98 %, avec une moyenne de 70,11 ± 18,45 %. La residence urbaine etait associee a un meilleur SMG de la qualite de vie ( p = 0,01). Le niveau d’education etait correle aux dimensions de la vision de loin ( p = 0,01), du fonctionnement social ( p = 0,03), de la limitation des activites physiques ( p = 0,01) et de la vision peripherique ( p = 0,01). Le score de qualite de vie global etait inversement correle, et de facon tres significative, a l’anciennete du glaucome ( p = 0,002), aux excavations papillaires du meilleur et du mauvais œil ( p −4 ), a la meilleure acuite visuelle corrigee du meilleur et du mauvais œil ( p −4 ), mais pas a la pression intraoculaire. Une association inverse entre le nombre de traitements et la qualite de vie a ete objectivee, et ce, pour le SMG ( p = 0,03) et les SMD de la limitation des activites physiques ( p = 0,04) et de la conduite ( p = 0,002). Conclusions La qualite de vie des patients glaucomateux, mesuree par le NEI-VFQ questionnaire, est correlee a plusieurs elements sociodemographiques et cliniques. L’evaluation de la qualite de vie est un facteur essentiel a considerer pour la prise en charge des glaucomateux. Dans notre contexte, les recherches doivent s’orienter d’abord vers la validation d’un questionnaire en dialecte local.

Blepharophimosis ptosis epicanthus inversus syndrome (BPES) is a rare congenital hereditary abnormality. It includes complex orbital-palpebral malformations, causing aesthetic and functional ramifications. Management of BPES requires two steps : diagnosis and treatment.We performed a retrospective descriptive study of 44 patients (88 eyelids) with blepharophimosis-ptosis-epicanthus inversus syndrome (BPES). In our series, we opted for two-stage surgery in 28 cases : epicanthus-telecanthus surgery followed by ptosis surgery. Simultaneous surgery was performed in 5 cases.The mean age at the first visit was 6 years (6.1±6.4). The mean age of our patients at the time of the first surgery was 6.6 years. Epicanthus surgery was performed in 35 cases. The two techniques used to correct epicanthus were Y-V plasty in 30 cases (85.7%, n=35) and Y-V+double Z plasty in 5 cases (14.3%, n=35). Correction of the telecanthus was performed at the same time by a medial canthal tendon plication in 31 cases (88.6%, n=35) or transnasal canthopexy in 4 cases (11.4%, n=35). The mean age at the time of ptosis surgery was 7.23 years (±6.25), ranging from 8 months to 27 years. Ptosis surgery was performed in 41 cases (79 eyelids), of which 3 patients underwent unilateral ptosis surgery due to asymmetrical ptosis. The techniques used were levator resection in 64 eyelids and frontal suspension in 15 eyelids.BPES is often clinically diagnosed. The difficulty in management lies in the complex surgery required. There is no established consensus regarding surgical techniques or the timing of the surgeries.

The banded murex Hexaplex trunculus and purple dye murex Bolinus brandaris are frequently caught as bycatch by bottom trawlers operating in the Gulf of Gabes, southern Tunisia. Although these muricid gastropods might importantly constitute an additional source of income for fishermen as well as help to diversify local shellfish production, information on their catches is relatively scarce. Hence, the present study aimed to assess the status of local populations of H. trunculus and B. brandaris, including data on their spatial and depth distributions, abundance, biomass, population structure and mortality. Fishing surveys using bottom trawls were performed between May 2006 and June 2007 in offshore areas of the Gulf of Gabes. In total, 198 fishing hauls were analysed, corresponding to a total fishing duration of 333.3 hours and a total prospecting area of 1 534 ha at depths of 20–86 m. Altogether, 3 026 H. trunculus and 3 599 B. brandaris of a broad size range (22.9−91.1 and 22.4−97.0 mm shell length, resp...

In this work, we study the Dirichlet partition on symmetric matrices. For this, we give some main properties of the Dirichlet distribution. Next, the result of Huillet and Martinez (2003) which gives a remarkable representation of the mean expected value of many functionals of Dirichlet distributions in terms of the mean of independent gamma random variables will be extended on positive definite symmetric matrices.

To assess the impact of glaucoma treatment and ocular surface disease (OSD) on the vision-specific quality-of-life (VS-QoL) of glaucoma patients attending Farhat Hached university hospital Sousse-Tunisia.This was a cross-sectional study enrolling one-hundred-twenty patients followed for primary open angle glaucoma. All patients successfully responded to the Arabic version of the National Eye Institute Visual Function Questionnaire 25 (NEI-VFQ 25). QoL was quantified in terms of scores (0-100) and correlated with the characteristics of glaucoma treatment and status of the ocular surface.One hundred and twenty patients were studied. The mean number of medications and instilled drops was 1.95 (1-4) and 2.69 (1-7) respectively. A total of 66.7% patients reported side effects of treatment. On examination, moderate or severe dry eye syndrome was identified in 90% of cases. A total of 16.7% of patients had superficial punctate keratopathy. The number of instilled drops per day, the use of brimonidine or oral carbonic anhydrase inhibitors, and the presence of OSD had a negative impact on the NEI-VFQ 25 scores.Glaucoma treatment and OSD are 2 factors potentially reducing the QoL of glaucoma patients, on which the ophthalmologist can act by optimizing treatment and regularly examining the ocular surface of glaucoma patients.

To assess the vision-specific quality-of-life (VS-QoL) of glaucoma patients followed at Farhat Hached university hospital, Sousse-Tunisia, and identify clinical and sociodemographic factors potentially affecting it.This was a cross-sectional study enrolling one-hundred twenty patients followed for primary open angle glaucoma (POAG). All the patients successfully responded to the Arabic version of the National Eye Institute Visual Function Questionnaire 25 (NEI-VFQ 25). Quality of life was quantified in terms of scores (0-100) and correlated with sociodemographic and clinical factors.One hundred and twenty patients were studied. The mean age was 62.38±10.68years. The global mean score (GMS) score was 70.11±18.45% ranging from 23.71 to 98%. Urban residence was associated with a better total score (P=0.01). Educational background was correlated with the subscale scores of distant activities (P=0.01), social functioning (P=0.03), physical activity limitations (P=0.01) and peripheral vision (P=0.01). The total NEI-VFQ 25 had a statistically significantly negative correlation with the duration of the glaucoma (P=0.002), the cup to disc ratio of the better and the worse eye (P10Vision-specific quality of life of glaucoma patients, as measured by the NEI-VFQ 25, is correlated to many sociodemographic and clinical elements. QoL evaluation is an essential factor to be considered in the management of glaucoma patients. In our context, research should be directed first to the validation of a questionnaire in the local dialect.

Summary From June 2004 to May 2006, the reproductive biology of the blue runner Caranx crysos was studied in the Gulf of Gabes (Southern Tunisia). Of 1668 individuals examined, 777 were females (46.6%) and 891 were males (53.4%). The sex ratio significantly deviated in favour of males (♀:♂ = 0.87 : 1). The difference in the numbers of females and males was significant among size-classes. However, there was no significant difference between sexes over months and seasons. Monthly changes in the Gonado-Somatic Index (GSI) showed a rapid increase during summer to very high levels in July (3.51% for males and 2.55% for females) and August (3.47% for males and 2.59% for females) before declining sharply in September (0.58% for females and 0.38% for males). The gametogenesis activity began with a pre-maturation phase, from 20 May to the first 10 days of July, followed by a pre-spawning phase, from 20 July to 20 August. From the last 10 days of August to 20 September the gonads were in the ripe and spawning stages. From the end of September to early May, gonads were in the post-spawning and resting stages. The size at which 50% of the population reached sexual maturity was significantly different in males and females: males attained sexual maturity at fork length FL50 = 210.20, whereas females attained maturity at FL50 = 222.3 mm. Age at maturity was 2.4 years for males and 2.8 years for females.

Resume Quatre patients, deux femmes âgees de 50 et de 67 ans, un homme de 36 ans et un enfant de cinq ans, ont presente une necrose cutanee suite a une anesthesie locale par la xylocaine adrenalinee a 2 %. Dans trois cas, l’anesthesie etait pratiquee avant la suture d’une plaie palpebrale et la necrose interessait la paupiere superieure. Dans un cas, l’anesthesie etait pratiquee avant une biopsie de l’artere temporale. Une necrose cutanee de toute la peau temporale etait observee. Dans tous les cas, une excision chirurgicale de la necrose etait realisee. Deux patients ont presente une surinfection bacterienne, traitee par des antibiotiques par voie generale avec une bonne evolution. La necrose des extremites secondaire a une injection d’une solution adrenalinee est une complication rare. Longuement decrite au niveau des doigts et bien connue des dermatologues, elle est due a un spasme vasculaire prolonge. Elle se voit surtout apres injection d’une trop grande quantite chez des sujets a risque (arterite, syndrome de Raynaud). Au niveau des paupieres, peu de cas ont ete rapportes.

In this work, we investigate the following inhomogeneous model of fragmentation with an exponential splitting probability: suppose that an initial particle having a mass x 0 > 0 (large enough) is broken, with a size-dependent probability p ( x 0 ) ≔ 1 − e − x 0 , into b > 1 pieces. With probability 1 − p ( x 0 ) , this fragment is left unchanged for ever. The process of fragmentation is repeated recursively for all pieces. Some statistical features are studied, chiefly the fragment size distribution, number of fragments and partition function of the random fragmentation tree. Also, we give details of the numerical analysis of these features.

This work is a continuation of the paper [9], where a particular fragmentation process of a unit interval II, according to a β-size-biased picking procedure (β ∈ ℝ) is investigated. It results from the splitting process, the production of a random countable partition of unity together with another random partitioning of some random quantity Z > 0.

Resume Le cancer du nasopharynx (CNP) represente une des tumeurs epitheliales les plus frequentes de l’enfant et de l’adolescent dans les regions a risque intermediaire. Dans les pays du Maghreb, il represente le premier cancer des adolescents âges de 15 a 20 ans. L’Epstein-Barr virus (EBV) est le facteur etiologique le plus important. Son role dans la pathogenese du CNP a ete confirme par plusieurs etudes. Chez les jeunes patients, le taux des anticorps anti-EBV est souvent peu eleve par rapport a celui observe chez les adultes. Deeme, le taux de cellules exprimant la LMP1 est beaucoup plus eleve. Le carcinome indifferencie de type nasopharynge (UCNT) represente le type histologique le plus frequent. L’etude immunohistochimique (IHC) des CNP juveniles nord-africains est caracterisee par une faible expression de Bcl-2 et de p53 et une forte expression de LMP1 et de c-kit, ce qui les fait distinguer des formes de l’adulte. Sur le plan clinique, l’atteinte ganglionnaire cervicale est quasi constante avec une extension locoregionale tres importante ainsi qu’a distance. Plus de 15 % des patients sont metastatiques au diagnostic notamment au niveau osseux. Le traitement repose essentiellement sur la radiotherapie. Seules des etudes retrospectives ont ete publiees pour determiner l’interet, le type et le timing de la chimiotherapie dans la prise en charge des CNP juveniles. La dose de radiotherapie reste un sujet de controverse surtout que les doses elevees se sont accompagnees d’une toxicite tardive invalidante. Les rechutes metastatiques constituent la cause principale de deces chez ces jeunes patients. Une amelioration du pronostic peut etre attendue en associant de facon concomitante la chimiotherapie a la radiotherapie avec modulation d’intensite. Cependant, desetudes randomisees multi-institutionnelles sont necessaires pour standardiser le traitement des CNP juveniles.

In this work, we give a representation of the mean expected value of many functionals of inverted Dirichlet distributions in terms of the mean of independent gamma random variables. Some remarkable properties are developed and illustrated. The Gibbs version of the inverted Dirichlet distribution with a selection parameter is considered. With the above-mentioned representation, the moment function of the geometrical average of the random variables according to the new distribution is obtained.

Extradural arachnoid cysts are uncommon expanding lesions in the spinal canal, which may communicate with the subarachnoid space. Usually located in the lower thoracic spine, they may cause symptoms by compressing the spinal cord or nerve roots. We report a case of an extradural thoracic arachnoid cyst revealed by progressive spinal cord compression. CT myelography and MRI enabled diagnosis. Rapid neurological improvement was observed after surgical resection.