Tumeur maligne des gaines nerveuses périphériques révélant une neurofibromatose type 1

La Neurofibromatose type 1 (NF1) ou maladie de Von Recklinghausen est une affection à expression clinique variable. La transformation maligne est rare et redoutable. Le but de ce travail est d’étudier les critères diagnostiques ainsi que la prise en charge thérapeutique de cette transformation maligne. Observation : A.B, âgé de 16 ans, a consulté pour une tuméfaction basicervicale antérieure d’apparition récente, ayant augmenté progressivement de taille sans signes de compression ni de dysthyroïdie. L’examen clinique a trouvé une masse dure, bien limitée, indolore, de 4 cm de grand axe siégeant en regard du manubrium sternal, adhérente au plan profond et débordant sur le creux sus sternal. A cette masse s’associaient des taches cutanées café au lait disséminées sur tout le corps, des nodules de Lish iriens et des neurofibromes occipitaux et parotidiens. Après une exérèse de la masse par voie cervicale, l’examen histologique a conclu à une tumeur maligne de la gaine nerveuse. Le malade a eu dans un 2ème temps, une exérèse plus large emportant le manubrium sternal et les tissus adjacents  avec une reconstruction par des fragments de côtes mais avec des limites chirurgicales envahies. L’évolution a été marquée par une poursuite évolutive précoce imposant une exérèse chirurgicale plus large suivie d’une chimiothérapie et d’une radiothérapie externe (RT). Le malade était cependant toujours en poursuite évolutive et le décès est survenu dans un contexte d'envahissement médiastinal.Mots-clés : Neurofibromatose type 1, Sarcome, tissus mous, gaines nerveuses périphériques, Chirurgie

Détection moléculaire du Coronavirus du Syndrome Respiratoire du Moyen-Orient (MERS-CoV) chez les dromadaires tunisiens (Camelus dromedarius)

Middle East Respiratory Syndrome Coronavirus (MERS-CoV) was identified in humans in 2012. Dromedary camels were considered as the major reservoir of the virus throw several studies. Tunisian dromedary camels were implicated in a serological survey and a seropositivity reaching 100% was observed among some of them. Therefore, more investigations are necessary to look for the current infection situation. In this study, we aimed to detect the MERS-CoV virus in our camels by molecular technics. Blood and nasal swabs samples from 64 dromedary camels from 4 Tunisian provinces were collected during June 2014 and April 2015. All the animals tested negative by real time reverse transcriptase–polymerase chain reaction assay (RT-PCR). These findings could not confirm the absence of MERS-CoV active shading among the Tunisian camel population and more researches should be carried on to survey dromedary camels in Tunisia and its neighboring countries. Keywords: Middle East respiratory syndrome (MERS), Camels, Tunisia, RT-PCR, animal surveillance, Coronavirus (CoVs), molecular detection.Le Coronavirus du syndrome respiratoire du Moyen-Orient (MERS-CoV) a été identifié chez l’Homme pour la première fois en 2012. A travers plusieurs études, les dromadaires ont été alors considérés comme étant le réservoir majeur du virus. Une enquête sérologique chez les dromadaires en Tunisie a permis de démontrer une séropositivité allant jusqu’à 100% chez certains sujets étudiés. Ainsi, des recherches supplémentaires semblent être nécessaires pour évaluer l’état d’infection actuel du pays. A travers cette étude, nous visons, par le biais de techniques moléculaires, la détection du virus (MERS-CoV) chez nos dromadaires tunisiens. Durant la période s’étalant entre juin 2014 et avril 2015, des échantillons de sang et des écouvillonnages nasaux ont été prélevés à partir de 64 individus prévenant de 4 gouvernorats. L’essai de la détection moléculaire, en utilisant la technique d’amplification génomique en chaîne de polymérase avec transcriptase inverse (RT-PCR), a démontré que tous les sujets étudiés ont donné un réponse négative. Cependant, ces résultats ne peuvent pas confirmer l’absence d’une excrétion active du virus chez la population cameline tunisienne, raison pour laquelle d’autres investigations doivent être enchaînées pour surveiller l’état d’infection cameline par le MERS-CoV non seulement en Tunisie mais également dans les pays voisins. Mots-clés: Le Syndrome Respiratoire du Moyen-Orient (SRMO), dromadaires, Tunisie, RT-PCR, surveillance animale, Coronavirus (CoVs), détection moléculair

Molecular detection of Middle East Respiratory Syndrome Coronavirus (MERS-CoV) in Tunisian dromedary camels (Camelus dromedarius)

Middle East Respiratory Syndrome Coronavirus (MERS-CoV) was identified in humans in 2012. Dromedary camels were considered as the major reservoir of the virus throw several studies. Tunisian dromedary camels were implicated in a serological survey and a seropositivity reaching 100% was observed among some of them. Therefore, more investigations are necessary to look for the current infection situation. In this study, we aimed to detect the MERS-CoV virus in our camels by molecular technics. Blood and nasal swabs samples from 64 dromedary camels from 4 Tunisian provinces were collected during June 2014 and April 2015. All the animals tested negative by real time reverse transcriptase–polymerase chain reaction assay (RT-PCR). These findings could not confirm the absence of MERS-CoV active shading among the Tunisian camel population and more researches should be carried on to survey dromedary camels in Tunisia and its neighboring countries

Prevalence of Mood Disorders and Associated Factors at the Time of the COVID-19 Pandemic: Potocol for a Community Survey in La Manouba Governorate, Tunisia

Aims: The present survey aims to assess the overall mood disorder prevalence and identify associated socio-demographic and clinical factors in a Tunisian community sample, with special attention to the COVID-19 pandemic. Background: Mood disorders are one of the leading causes of all non-fatal burdens of disease, with depression being at the top of the list. The COVID-19 pandemic may have increased the prevalence of mood disorders, especially in Low and Middle-income countries (LMICs) and in vulnerable populations. Objective: 1/ Assess point and lifetime prevalence of depressive and bipolar disorders as well as subthreshold bipolarity in a representative population sample of La Manouba governorate and assess treatment patterns for these disorders; 2/Study socio-demographic and clinical correlates of mood disorders 3/ Assess the association between mood disorders and quality of life 4/ Study the impact of the COVID-pandemic on the prevalence of mood disorders 5/ Assess coping mechanisms to the COVID-pandemic and whether these mechanisms moderate the appearance of mood disorders or symptoms since the beginning of the pandemic Methods: This is a household cross-sectional observational survey to be conducted in La Manouba Governorate in a sample of 4540 randomly selected individuals aged ≥ 15 years. Data collection will be carried out by trained interviewers with clinical experience, through face-to-face interviews and the use of the computer assisted personal interviewing approach (CAPI). The following assessment tools are administered: Results: Structured clinical Interview for DSM IV-TR (Mood disorder section and Screening questions on Anxiety), Mood Disorder Questionnaire (MDQ), Suicide Behaviors Questionnaire-Revised (SBQ), 12-item Short Form Survey (SF-12), the Brief-COPE, and a questionnaire about a headache. In addition, socio-demographic and clinical data will be collected. Conclusion: This will be one of the very few household surveys in a general population sample to assess mental health problems and COVID-19-related variables since the beginning of the pandemic. Through this research, we aim to obtain an epidemiological profile of mood disorders in Tunisia and an estimation of the impact of the COVID-19 pandemic on their prevalence. Results should contribute to improving mental health care in Tunisia

Conductance statistics from a large array of sub-10 nm molecular junctions

Devices made of few molecules constitute the miniaturization limit that both inorganic and organic-based electronics aspire to reach. However, integration of millions of molecular junctions with less than 100 molecules each has been a long technological challenge requiring well controlled nanometric electrodes. Here we report molecular junctions fabricated on a large array of sub-10 nm single crystal Au nanodots electrodes, a new approach that allows us to measure the conductance of up to a million of junctions in a single conducting Atomic Force Microscope (C-AFM) image. We observe two peaks of conductance for alkylthiol molecules. Tunneling decay constant (beta) for alkanethiols, is in the same range as previous studies. Energy position of molecular orbitals, obtained by transient voltage spectroscopy, varies from peak to peak, in correlation with conductance values.Comment: ACS Nano (in press

Universal Sequencing on a Single Machine

We consider scheduling on an unreliable machine that may experience unexpected changes in processing speed or even full breakdowns. We aim for a universal solution that performs well without adaptation for any possible machine behavior. For the objective of minimizing the total weighted completion time, we design a polynomial time deterministic algorithm that finds a universal scheduling sequence with a solution value within 4 times the value of an optimal clairvoyant algorithm that knows the disruptions in advance. A randomized version of this algorithm attains in expectation a ratio of e. We also show that both results are best possible among all universal solutions. As a direct consequence of our results, we answer affirmatively the question of whether a constant approximation algorithm exists for the offline version of the problem when machine unavailability periods are known in advance. When jobs have individual release dates, the situation changes drastically. Even if all weights are equal, there are instances for which any universal solution is a factor of Ω(log n/ log log n) worse than an optimal sequence. Motivated by this hardness, we study the special case when the processing time of each job is proportional to its weight. We present a non-trivial algorithm with a small constant performance guarantee. © 2010 Springer-Verlag

A Mathematical Model and a Firefly Algorithm for an Extended Flexible Job Shop Problem with Availability Constraints

Manufacturing scheduling strategies have historically ignored the availability of the machines. The more realistic the schedule, more accurate the calculations and predictions. Availability of machines will play a crucial role in the Industry 4.0 smart factories. In this paper, a mixed integer linear programming model (MILP) and a discrete firefly algorithm (DFA) are proposed for an extended multi-objective FJSP with availability constraints (FJSP-FCR). Several standard instances of FJSP have been used to evaluate the performance of the model and the algorithm. New FJSP-FCR instances are provided. Comparisons among the proposed methods and other state-of-the-art reported algorithms are also presented. Alongside the proposed MILP model, a Genetic Algorithm is implemented for the experiments with the DFA. Extensive investigations are conducted to test the performance of the proposed model and the DFA. The comparisons between DFA and other recently published algorithms shows that it is a feasible approach for the stated problem

An elitist quantum-inspired evolutionary algorithm for the flexible job-shop scheduling problem

The flexible job shop scheduling problem (FJSP) is vital to manufacturers especially in today’s constantly changing environment. It is a strongly NP-hard problem and therefore metaheuristics or heuristics are usually pursued to solve it. Most of the existing metaheuristics and heuristics, however, have low efficiency in convergence speed. To overcome this drawback, this paper develops an elitist quantum-inspired evolutionary algorithm. The algorithm aims to minimise the maximum completion time (makespan). It performs a global search with the quantum-inspired evolutionary algorithm and a local search with a method that is inspired by the motion mechanism of the electrons around an atomic nucleus. Three novel algorithms are proposed and their effect on the whole search is discussed. The elitist strategy is adopted to prevent the optimal solution from being destroyed during the evolutionary process. The results show that the proposed algorithm outperforms the best-known algorithms for FJSPs on most of the FJSP benchmarks

Contribution of type 2 diabetes associated loci in the Arabic population from Tunisia: a case-control study

<p>Abstract</p> <p>Background</p> <p>Candidate gene and genome-wide association studies have both reproducibly identified several common Single Nucleotide Polymorphisms (SNPs) that confer type 2 diabetes (T2D) risk in European populations. Our aim was to evaluate the contribution to T2D of five of these established T2D-associated loci in the Arabic population from Tunisia.</p> <p>Methods</p> <p>A case-control design comprising 884 type 2 diabetic patients and 513 control subjects living in the East-Center of Tunisia was used to analyze the contribution to T2D of the following SNPs: E23K in <it>KCNJ11/Kir6.2</it>, K121Q in <it>ENPP1</it>, the -30G/A variant in the pancreatic β-cell specific promoter of Glucokinase, rs7903146 in <it>TCF7L2 </it>encoding transcription factor 7-like2, and rs7923837 in <it>HHEX </it>encoding the homeobox, hematopoietically expressed transcription factor.</p> <p>Results</p> <p><it>TCF7L2</it>-rs7903146 T allele increased susceptibility to T2D (OR = 1.25 [1.06–1.47], <it>P </it>= 0.006) in our study population. This risk was 56% higher among subjects carrying the TT genotype in comparison to those carrying the CC genotype (OR = 1.56 [1.13–2.16], <it>P </it>= 0.002). No allelic or genotypic association with T2D was detected for the other studied polymorphisms.</p> <p>Conclusion</p> <p>In the Tunisian population, <it>TCF7L2</it>-rs7903146 T allele confers an increased risk of developing T2D as previously reported in the European population and many other ethnic groups. In contrast, none of the other tested SNPs that influence T2D risk in the European population was associated with T2D in the Tunisian Arabic population. An insufficient power to detect minor allelic contributions or genetic heterogeneity of T2D between different ethnic groups can explain these findings.</p

Antibacterial activity of Thymoquinone, an active principle of Nigella sativa and its potency to prevent bacterial biofilm formation

<p>Abstract</p> <p>Background</p> <p>Thymoquinone is an active principle of <it>Nigella sativa </it>seed known as "Habbah Al-Sauda" in Arabic countries and "Sinouj" in Tunisia. Bacterial biofilms tend to exhibit significant tolerance to antimicrobials drugs during infections.</p> <p>Methods</p> <p>The antibacterial activity of Thymoquinone (TQ) and its biofilm inhibition potencies were investigated on 11 human pathogenic bacteria. The growth and development of the biofilm were assessed using the crystal violet (CV) and the 2, 3-bis [2-methyloxy-4-nitro-5-sulfophenyl]-2H-tetrazolium-5-carboxanilide (XTT) reduction assay.</p> <p>Results</p> <p>TQ exhibited a significant bactericidal activity against the majority of the tested bacteria (MICs values ranged from 8 to 32 μg/ml) especially Gram positive cocci (<it>Staphylococcus aureus </it>ATCC 25923 and <it>Staphylococcus epidermidis </it>CIP 106510). Crystal violet assay demonstrated that the minimum biofilm inhibition concentration (BIC50) was reached with 22 and 60 μg/ml for <it>Staphylococcus aureus </it>ATCC 25923 and <it>Staphylococcus epidermidis </it>CIP 106510 respectively. In addition our data revealed that cells oxidative activity was influenced by TQ supplementation. In the same way, TQ prevented cell adhesion to glass slides surface.</p> <p>Conclusion</p> <p>The ability of TQ to prevent biofilm formation warrants further investigation to explore its use as bioactive substances with antibiofilm potential.</p