43 results on '"M. Chaouch"'
Search Results
2. Wood thermodegradation: experimental analysis and modeling of mass loss kinetics
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A. Pétrissans, R. Younsi, M. Chaouch, P. Gérardin, and M. Pétrissans
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heat treatment ,modeling ,reaction kinetics ,thermodegradation ,wood ,Forestry ,SD1-669.5 ,Manufactures ,TS1-2301 - Abstract
In this study, heat treatment was carried out in a relatively low temperature (230˚C). Mass loss kinetics was studied using equipment, specially conceived to measure sample’s mass during the thermal treatment. Laboratory experiments were performed for heating rates of 1˚C min-1. Mathematical model for kinetics of pyrolysis process was used and validated. During the pyrolysis of dry wood samples under inert atmosphere, measurements of temperature distribution and dynamic weight loss were performed. Five different wood species Fagus sylvatica (Beech), Populus nigra (Poplar), Fraxinus excelsior (Ash), Pinus sylvestris (Pine) and Abies pectinata (Silver Fir) were investigated. The unsteady-state mathematical model equations were solved numerically using the commercial package Femlab 2.0. A detailed discussion of the computational model and the solution algorithm is given. The validity of different model assumptions was analyzed. Experimental results were compared with those calculated by the model. Acceptable agreement was achieved.
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- 2014
3. Preparation and Characterisation A Catalytic System Cu-Clay for Catalytic Oxidation of Methyl Orange with H2O2
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M. Idrissi, Y. Miyah, M. Chaouch, F. Zerrouq, and A. Lahrichi
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inorganic chemicals ,chemistry.chemical_element ,Orange (colour) ,Fluorescence ,Copper ,Catalysis ,Metal ,chemistry.chemical_compound ,chemistry ,Catalytic oxidation ,visual_art ,Methyl orange ,visual_art.visual_art_medium ,Hydrogen peroxide ,Nuclear chemistry - Abstract
3 ABSTRACT: In this work, the decolorization of Methyl Orange was conducted using catalysts prepared by impregnation of copper on natural clay in the presence of H2O2. The catalysts Cu-clay, prepared from the concentrated metal precursor of (impregnation ratio, W(Cu(NO3)2)/W(clay) = 1,5%-7,5%) were characterized by several methods such as X-ray diffraction (XRD), electronic scan microscopy (SEM), x-ray fluorescence (FX), and Brunauer-Emmett- Teller (BET). Important factors affecting catalyst activity and methyl orange removal efficiencies were studied: the effects of temperature, oxidant concentration, and catalyst dosage. The results showed, a very significant activation of hydrogen peroxide by the catalyst, the Methyl Orange depletion percentage reaching 94 % after 2 h, and very stability of the catalyst. It was also observed that the best catalyst, at a reaction temperature of 25°C. 2,5ml of H2O2 and 4.0 g/L of 5% Cu-clay, 94% decolorization was achieved within 120 min treatment. Although the Cu show high activity, their stability and reusability still need improvement.
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- 2014
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4. New Varieties of Zinc–Chromium–Sulfate Lamellar Double Hydroxides
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M. Khaldi, A. De Roy, Jean-Pierre Besse, and M. Chaouch
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Ammonium sulfate ,Chemistry ,Coprecipitation ,Inorganic chemistry ,chemistry.chemical_element ,Zinc ,Condensed Matter Physics ,Electronic, Optical and Magnetic Materials ,Inorganic Chemistry ,Chromium ,chemistry.chemical_compound ,Sodium sulfate ,Materials Chemistry ,Ceramics and Composites ,Lamellar structure ,Lithium ,Physical and Theoretical Chemistry ,Sulfate - Abstract
The synthesis of zinc–chromium lamellar double hydroxides (LDHs) intercalated by sulfate anions is carried out with a one-step method that combines coprecipitation and anionic exchange. The materials obtained in a reactor containing a sodium sulfate solution are compared with those prepared from lithium, potassium, and ammonium sulfate solutions. The compounds are characterized by chemical analysis, powder X-ray diffraction, and infra-red spectroscopy. Depending on pH conditions, the washing process, and the nature of the monovalent cation, the sulfate intercalated compounds exhibit two 2H hexagonal varieties with different layer spacings d ≈8.9 A and d ≈11 A at room temperature; this last phase is related to the insertion of alkaline interlamellar cations. Under dry air, the loss of intercalated water leads to a 3R rhombohedral variety with d ≈8.2 A. A second rhombohedral variety with d ≈10.9 A is reversibly obtained from the “8.9 A” phase under high relative humidity. These four [Zn–Cr–SO 4 ] LDHs differ by their stacking sequences and interlamellar distances and can be selectively obtained.
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- 1997
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5. Phenotypic variability in autosomal recessive axonal Charcot-Marie-Tooth disease due to the R298C mutation in lamin A/C
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Meriem Tazir, Jean-Michel Vallat, D. Grid, Tarik Hamadouche, Josué Feingold, Hamid Azzedine, S. Assami, Sonia Nouioua, Eric LeGuern, R Zemmouri, M Chaouch, P Sindou, Service de Neurologie, Centre Hospitalier UniversitaireMustapha, INSERM U 289 and Federation of Neurology, Salpt- trikre Hospital, Paris, France., Service de Neurologie [CHU Limoges], CHU Limoges, Laboratoire de Biologie Moleculaire, InstitutPasteur, Service de Neurologie, Centre HospitalierUniversitaire de Ben-Aknoun, Alger, Algeria, De¬partement de Ge¬ne¬tique,Cytoge¬ne¬tique et Embryologie, Ho√pital de laPitie¬-Salpe√trie¡re, Paris, and Généthon
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Adult ,Male ,Pathology ,medicine.medical_specialty ,Adolescent ,Neural Conduction ,Motor nerve ,Genes, Recessive ,[SDV.BC]Life Sciences [q-bio]/Cellular Biology ,Biology ,Nerve Fibers, Myelinated ,Nerve conduction velocity ,Central nervous system disease ,LMNA ,03 medical and health sciences ,0302 clinical medicine ,Degenerative disease ,Charcot-Marie-Tooth Disease ,medicine ,Humans ,Age of Onset ,Child ,ComputingMilieux_MISCELLANEOUS ,030304 developmental biology ,0303 health sciences ,Nerve Fibers, Unmyelinated ,Nerve biopsy ,medicine.diagnostic_test ,Anatomy ,medicine.disease ,Lamin Type A ,3. Good health ,Compound muscle action potential ,Median Nerve ,Phenotype ,Chromosomes, Human, Pair 1 ,Mutation ,Disease Progression ,Female ,Neurology (clinical) ,Age of onset ,030217 neurology & neurosurgery - Abstract
Summary Autosomal recessive forms of axonal Charcot‐Marie‐ Tooth (ARCMT2) disease are frequent in some areas, such as North Africa and the Middle East, since consanguineous marriages are still common there. Recently, a unique homozygous mutation in LMNA, which encodes lamin A/C, a component of the nuclear envelope, was identified in members of three Algerian families with ARCMT2 linked to chromosome 1q21.2-q21.3. In the present study we describe a group of 21 ARCMT2 patients from seven unrelated Algerian families with the same R298C mutation in the lamin A/C gene and marked variability of the clinical phenotype. There is a wide range of age of onset, from 6 to 27 years, with a mean of 14.4 6 4.6 years. The course of the disease varies considerably from one patient to another. Twelve patients with a disease duration of 10‐15 years had a severe CMT phenotype with distal wasting and weakness of all four limbs and areflexia associated with involvement of the proximal lower limb muscles. In contrast, nine patients had the classical CMT phenotype with mild functional disability without proximal lower limb involvement after a disease duration of 5‐18 years. Electrophysiological studies showed a median motor nerve conduction velocity (MNCV) in the normal range in almost all the patients. MNCV and compound muscle action potential (CMAP) values were inversely correlated with the disease duration and the MNCV was strictly related to the CMAP, strongly supporting a pure axonal process without a demyelinating component. Six patients had a nerve biopsy, which revealed severe rarefaction of myelinated fibres in all cases and an increased density of unmyelinated fibres in the majority of cases. In conclusion, the ARCMT2 associated with the R298C mutation differs from other types of ARCMT2. The variability among patients in the age of onset and the course of the disease strongly suggests the action of modifying genes, which remain to be identified.
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- 2004
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6. Deficiency of the 50K dystrophin-associated glycoprotein in severe childhood autosomal recessive muscular dystrophy
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Jean-Claude Kaplan, K. Azibi, Fernando M.S. Tomé, Michel Fardeau, M. Chaouch, H. Collin, Kevin P. Campbell, and K. Matsumura
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musculoskeletal diseases ,congenital, hereditary, and neonatal diseases and abnormalities ,medicine.medical_specialty ,Biopsy ,Duchenne muscular dystrophy ,Genes, Recessive ,Muscular Dystrophies ,Sarcospan ,Dystrophin ,Necrosis ,Sarcolemma ,Internal medicine ,medicine ,Humans ,Muscular dystrophy ,Child ,Dystroglycans ,Membrane Glycoproteins ,Multidisciplinary ,biology ,business.industry ,Muscles ,Dystrophy ,musculoskeletal system ,medicine.disease ,Dystrophin-associated protein ,Dystroglycan complex ,Molecular Weight ,Cytoskeletal Proteins ,Endocrinology ,Sarcoglycanopathy ,biology.protein ,Electrophoresis, Polyacrylamide Gel ,business - Abstract
X-LINKED recessive Duchenne muscular dystrophy (DMD) is caused by the absence of dystrophin, a membrane cytoskeletal protein1,2. Dystrophin is associated with a large oligomeric com-plex of sarcolemmal glycoproteins3–10. The dystrophin–glycoprotein complex has been proposed to span the sarcolemma to provide a link fyetween the subsarcolemmal cytoskeleton and the extracellular matrix component, laminin7,9. In DMD, the absence of dystrophin leads to a large reduction in all of the dystrophin-associated proteins4,9,10. We have investigated the possibility that a deficiency of a dystrophin-associated protein could be the cause of severe childhood autosomal recessive mus-cular dystrophy (SCARMD) with a DMD-like phenotype11–14. Here we report the specific deficiency of the 50K dystrophin-associated glycoprotein (Mr 50,000) in sarcolemma of SCARMD patients. Therefore, the loss of this glycoprotein is a common denominator of the pathological process leading to muscle cell necrosis in two forms of muscular dystrophy, DMD and SCARMD.
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- 1992
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7. Phenotypic variability in autosomal recessive axonal Charcot-Marie-Tooth disease due to the R298C mutation in lamin A/C.
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M. Tazir, H. Azzedine, S. Assami, P. Sindou, S. Nouioua, R. Zemmouri, T. Hamadouche, M. Chaouch, J. Feingold, J. M. Vallat, E. Leguern, and D. Grid
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- 2004
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8. Genome Tunisia Project: paving the way for precision medicine in North Africa.
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Hamdi Y, Trabelsi M, Ghedira K, Boujemaa M, Ben Ayed I, Charfeddine C, Souissi A, Rejeb I, Kammoun Rebai W, Hkimi C, Neifar F, Jandoubi N, Mkaouar R, Chaouch M, Bennour A, Kamoun S, Chaker Masmoudi H, Abid N, Mezghani Khemakhem M, Masmoudi S, Saad A, BenJemaa L, BenKahla A, Boubaker S, Mrad R, Kamoun H, Abdelhak S, Gribaa M, Belguith N, Kharrat N, Hmida D, and Rebai A
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- Humans, Tunisia, Genomics methods, Africa, Northern, Precision Medicine methods, Genome, Human
- Abstract
Background: Key discoveries and innovations in the field of human genetics have led to the foundation of molecular and personalized medicine. Here, we present the Genome Tunisia Project, a two-phased initiative (2022-2035) which aims to deliver the reference sequence of the Tunisian Genome and to support the implementation of personalized medicine in Tunisia, a North African country that represents a central hub of population admixture and human migration between African, European, and Asian populations. The main goal of this initiative is to develop a healthcare system capable of incorporating omics data for use in routine medical practice, enabling medical doctors to better prevent, diagnose, and treat patients., Methods: A multidisciplinary partnership involving Tunisian experts from different institutions has come to discern all requirements that would be of high priority to fulfill the project's goals. One of the most urgent priorities is to determine the reference sequence of the Tunisian Genome. In addition, extensive situation analysis and revision of the education programs, community awareness, appropriate infrastructure including sequencing platforms and biobanking, as well as ethical and regulatory frameworks, have been undertaken towards building sufficient capacity to integrate personalized medicine into the Tunisian healthcare system., Results: In the framework of this project, an ecosystem with all engaged stakeholders has been implemented including healthcare providers, clinicians, researchers, pharmacists, bioinformaticians, industry, policymakers, and advocacy groups. This initiative will also help to reinforce research and innovation capacities in the field of genomics and to strengthen discoverability in the health sector., Conclusions: Genome Tunisia is the first initiative in North Africa that seeks to demonstrate the major impact that can be achieved by Human Genome Projects in low- and middle-income countries to strengthen research and to improve disease management and treatment outcomes, thereby reducing the social and economic burden on healthcare systems. Sharing this experience within the African scientific community is a chance to turn a major challenge into an opportunity for dissemination and outreach. Additional efforts are now being made to advance personalized medicine in patient care by educating consumers and providers, accelerating research and innovation, and supporting necessary changes in policy and regulation., (© 2024. The Author(s).)
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- 2024
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9. Emergence of Plasmid-Mediated Quinolone Resistance (PMQR) Genes in Campylobacter coli in Tunisia and Detection of New Sequence Type ST13450.
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Gharbi M, Tiss R, Chaouch M, Hamrouni S, and Maaroufi A
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The aim of this study is to investigate the occurrence of plasmid mediated quinolone resistance (PMQR) determinants in Campylobacter coli isolates collected from broilers, laying hens and poultry farm environments. One hundred and thirty-nine C. coli isolates were isolated from broilers (n = 41), laying hens (n = 53), eggs (n = 4) and the environment (n = 41) of 23 poultry farms located in northeastern of Tunisia. Antimicrobial susceptibility testing was performed on all isolates according to the recommendation of the European Committee on Antimicrobial Susceptibility Testing guidelines. The detection of PMQR genes: qnrA , qnrB , qnrC , qnrD , qnrS , qepA , and aac (6) -Ib gene was performed using polymerase chain reaction (PCR) and specific primers. aac (6')-Ib amplicons were further analyzed by digestion with BtsCI to identify the aac (6')- Ib-cr variant. Mutations in GyrA and the occurrence of RE-CmeABC efflux pump were determined by mismatch amplification mutation assay (MAMA) PCR and PCR, respectively. In addition, eleven isolates were selected to determine their clonal lineage by MLST. The 139 C. coli isolates were resistant to ciprofloxacin, and 86 (61.8%) were resistant to nalidixic acid. High rates of resistance were also observed toward erythromycin (100%), azithromycin (96.4%), tetracycline (100%), chloramphenicol (98.56%), ampicillin (66.1%), amoxicillin-clavulanic acid (55.39%), and kanamycin (57.55%). However, moderate resistance rates were observed for gentamicin (9.35%) and streptomycin (22.3%). All quinolone-resistant isolates harbored the Thr-86-Ile amino acid substitution in GyrA, and the RE-CmeABC efflux pump was detected in 40.28% of isolates. Interestingly, the qnrB , qnrS , qepA , and aac (6')- Ib - cr were detected in 57.7%, 61.15%, 21.58%, and 10% of isolates, respectively. The eleven isolates studied by MLST belonged to a new sequence type ST13450. This study described for the first time the occurrence of PMQR genes in C. coli isolates in Tunisia and globally.
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- 2024
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10. Thermo-Hydric Study of Wood-Based Materials under Thermal Comfort Conditions.
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Haddouche M, Martini F, Chaouch M, and Ilinca A
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This paper tackles the issue of moisture variation in wood-based materials, explicitly focusing on melamine-coated particleboard (hereafter referred to as melamine) and medium-density fiberboard (MDF) used in the third phase of wood industry transformation. The approach involves a comprehensive strategy for predicting moisture content variation, incorporating numerical simulation, experimental testing, and the application of artificial neural network (ANN) technology to enhance accuracy in furniture manufacturing. The developed ANN models are tailored to predict moisture content changes under specific thermal comfort conditions. Remarkably, these models demonstrate high precision, with an average error margin of only 1.40% for 8% moisture content (MC) and 2.85% for 12% MC in melamine, as well as 1.42% for 8% MC and 2.25% for 12% MC in MDF. These levels of precision surpass traditional models, emphasizing this study's novelty and practical relevance to the industrial context. The findings indicate that ANN models adapt to diverse environmental conditions, presenting a robust tool for optimizing moisture management in wood-based materials. This research contributes valuable insights for improving the reliability and efficiency of moisture content predictions in the wood industry.
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- 2024
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11. Retrospective Phylodynamic and Phylogeographic Analysis of the Bluetongue Virus in Tunisia.
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Souiai O, Arbi M, Hanachi M, Sallami A, Larbi I, Chaouch M, Harigua-Souiai E, and Benkahla A
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Bluetongue virus (BTV) is an arbovirus considered as a major threat for the global livestock economy. Since 1999, Tunisia has experienced several incursions of BTV, during which numerous cases of infection and mortality have been reported. However, the geographical origin and epidemiological characteristics of these incursions remained unclear. To understand the evolutionary history of BTV emergence in Tunisia, we extracted from Genbank the segment 6 sequences of 7 BTV strains isolated in Tunisia during the period 2000 to 2017 and blasted them to obtain a final dataset of 67 sequences. We subjected the dataset to a Bayesian phylogeography framework inferring geographical origin and serotype as phylodynamic models. Our results suggest that BTV-2 was first introduced in Tunisia in the 1960s and that since 1990s, the country has witnessed the emergence of other typical and atypical BTV serotypes notably BTV-1, BTV-3 and BTV-Y. The reported serotypes have a diverse geographical origin and have been transmitted to Tunisia from countries in the Mediterranean Basin. Interserotype reassortments have been identified among BTV-1, BTV-2 and BTV-Y. This study has provided new insights on the temporal and geographical origin of BTV in Tunisia, suggesting the contribution of animal trade and environment conditions in virus spread., Competing Interests: The author declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article., (© The Author(s) 2023.)
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- 2023
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12. PHINDaccess Hackathons for COVID-19 and Host-Pathogen Interaction: Lessons Learned and Recommendations for Low- and Middle-Income Countries.
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Ghedira K, Dallali H, Ardhaoui M, Bouslema Z, Hamdi Y, Feki Ben-Salah S, Chelbi H, Atri C, Chaouch M, Dekhil N, Rais A, Azouz S, Gharbi M, Guerfali F, Hkimi C, Kamoun S, Ksouri A, Moumni I, Ouragini H, Bsibes R, Afifi Z, Youssfi K, Ben Hassine H, Hadhri N, Mardassi H, Othman H, and Khamessi O
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- Humans, SARS-CoV-2 genetics, Developing Countries, Pandemics, Host-Pathogen Interactions genetics, COVID-19 epidemiology
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Hackathons are collaborative events that bring together diverse groups to solve predefined challenges. The COVID-19 pandemic caused by SARS-CoV-2 has emphasized the need for portable and reproducible genomics analysis pipelines to study the genetic susceptibility of the human host and investigate human-SARS-CoV-2 protein interactions. To build and strengthen institutional capacities in OMICS data analysis applied to host-pathogen interaction (HPI), the PHINDaccess project organized two hackathons in 2020 and 2021. These hackathons are aimed at developing bioinformatics pipelines related to the SARS-CoV-2 viral genome, its phylodynamic transmission, and the identification of human genome host variants, with a focus on addressing global health challenges, particularly in low- and middle-income countries (LMIC). This paper outlines the preparation, proceedings, and lessons learned from these hackathons, including the challenges faced by participants and our recommendations based on our experience for organizing hackathons in LMIC and beyond., Competing Interests: The authors declare no conflict of interest., (Copyright © 2023 Kais Ghedira et al.)
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- 2023
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13. Developing Clinical Phenotype Data Collection Standards for Research in Africa.
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Zass L, Johnston K, Benkahla A, Chaouch M, Kumuthini J, Radouani F, Mwita LA, Alsayed N, Allie T, Sathan D, Masamu U, Seuneu Tchamga MS, Tamuhla T, Samtal C, Nembaware V, Gill Z, Ahmed S, Hamdi Y, Fadlelmola F, Tiffin N, and Mulder N
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- Humans, Retrospective Studies, Africa, Data Collection, Phenotype, Prospective Studies
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Modern biomedical research is characterised by its high-throughput and interdisciplinary nature. Multiproject and consortium-based collaborations requiring meaningful analysis of multiple heterogeneous phenotypic datasets have become the norm; however, such analysis remains a challenge in many regions across the world. An increasing number of data harmonisation efforts are being undertaken by multistudy collaborations through either prospective standardised phenotype data collection or retrospective phenotype harmonisation. In this regard, the Phenotype Harmonisation Working Group (PHWG) of the Human Heredity and Health in Africa (H3Africa) consortium aimed to facilitate phenotype standardisation by both promoting the use of existing data collection standards (hosted by PhenX), adapting existing data collection standards for appropriate use in low- and middle-income regions such as Africa, and developing novel data collection standards where relevant gaps were identified. Ultimately, the PHWG produced 11 data collection kits, consisting of 82 protocols, 38 of which were existing protocols, 17 were adapted, and 27 were novel protocols. The data collection kits will facilitate phenotype standardisation and harmonisation not only in Africa but also across the larger research community. In addition, the PHWG aims to feed back adapted and novel protocols to existing reference platforms such as PhenX., Competing Interests: The authors declare that they have no conflicts of interest., (Copyright © 2023 Lyndon Zass et al.)
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- 2023
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14. The unrestricted global effort to complete the COOL trial.
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Kirkpatrick AW, Coccolini F, Tolonen M, Minor S, Catena F, Gois E Jr, Doig CJ, Hill MD, Ansaloni L, Chiarugi M, Tartaglia D, Ioannidis O, Sugrue M, Colak E, Hameed SM, Lampela H, Agnoletti V, McKee JL, Garraway N, Sartelli M, Ball CG, Parry NG, Voght K, Julien L, Kroeker J, Roberts DJ, Faris P, Tiruta C, Moore EE, Ammons LA, Anestiadou E, Bendinelli C, Bouliaris K, Carroll R, Ceresoli M, Favi F, Gurrado A, Rezende-Neto J, Isik A, Cremonini C, Strambi S, Koukoulis G, Testini M, Trpcic S, Pasculli A, Picariello E, Abu-Zidan F, Adeyeye A, Augustin G, Alconchel F, Altinel Y, Hernandez Amin LA, Aranda-Narváez JM, Baraket O, Biffl WL, Baiocchi GL, Bonavina L, Brisinda G, Cardinali L, Celotti A, Chaouch M, Chiarello M, Costa G, de'Angelis N, De Manzini N, Delibegovic S, Di Saverio S, De Simone B, Dubuisson V, Fransvea P, Garulli G, Giordano A, Gomes C, Hayati F, Huang J, Ibrahim AF, Huei TJ, Jailani RF, Khan M, Luna AP, Malbrain MLNG, Marwah S, McBeth P, Mihailescu A, Morello A, Mulita F, Murzi V, Mohammad AT, Parmar S, Pak A, Wong MP, Pantalone D, Podda M, Puccioni C, Rasa K, Ren J, Roscio F, Gonzalez-Sanchez A, Sganga G, Scheiterle M, Slavchev M, Smirnov D, Tosi L, Trivedi A, Vega JAG, Waledziak M, Xenaki S, Winter D, Wu X, Zakaria AD, and Zakaria Z
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- Humans, Inflammation, Multiple Organ Failure etiology, Prospective Studies, United States, Abdomen, Laparotomy adverse effects
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Background: Severe complicated intra-abdominal sepsis (SCIAS) has an increasing incidence with mortality rates over 80% in some settings. Mortality typically results from disruption of the gastrointestinal tract, progressive and self-perpetuating bio-mediator generation, systemic inflammation, and multiple organ failure. A further therapeutic option may be open abdomen (OA) management with negative peritoneal pressure therapy (NPPT) to remove inflammatory ascites and attenuate the systemic damage from SCIAS, although there are definite risks of leaving the abdomen open whenever it might possibly be closed. This potential therapeutic paradigm is the rationale being assessed in the Closed Or Open after Laparotomy (COOL trial) ( https://clinicaltrials.gov/ct2/show/NCT03163095 ). Initially, the COOL trial received Industry sponsorship; however, this funding mandated the use of a specific trademarked and expensive NPPT device in half of the patients allocated to the intervention (open) arm. In August 2022, the 3 M/Acelity Corporation without consultation but within the terms of the contract canceled the financial support of the trial. Although creating financial difficulty, there is now no restriction on specific NPPT devices and removing a cost-prohibitive intervention creates an opportunity to expand the COOL trial to a truly global basis. This document describes the evolution of the COOL trial, with a focus on future opportunities for global growth of the study., Methods: The COOL trial is the largest prospective randomized controlled trial examining the random allocation of SCIAS patients intra-operatively to either formal closure of the fascia or the use of the OA with an application of an NPPT dressing. Patients are eligible if they have free uncontained intraperitoneal contamination and physiologic derangements exemplified by septic shock OR severely adverse predicted clinical outcomes. The primary outcome is intended to definitively inform global practice by conclusively evaluating 90-day survival. Initial recruitment has been lower than hoped but satisfactory, and the COOL steering committee and trial investigators intend with increased global support to continue enrollment until recruitment ensures a definitive answer., Discussion: OA is mandated in many cases of SCIAS such as the risk of abdominal compartment syndrome associated with closure, or a planned second look as for example part of "damage control"; however, improved source control (locally and systemically) is the most uncertain indication for an OA. The COOL trial seeks to expand potential sites and proceed with the evaluation of NPPT agnostic to device, to properly examine the hypothesis that this treatment attenuates systemic damage and improves survival. This approach will not affect internal validity and should improve the external validity of any observed results of the intervention., Trial Registration: National Institutes of Health ( https://clinicaltrials.gov/ct2/show/NCT03163095 )., (© 2023. The Author(s).)
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- 2023
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15. Historical Westward Migration Phases of Ovis aries Inferred from the Population Structure and the Phylogeography of Occidental Mediterranean Native Sheep Breeds.
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Ben Sassi-Zaidy Y, Mohamed-Brahmi A, Chaouch M, Maretto F, Cendron F, Charfi-Cheikhrouha F, Ben Abderrazak S, Djemali M, and Cassandro M
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- Animals, Genotype, Humans, Microsatellite Repeats, Phylogeography, Sheep genetics, Genetic Variation genetics, Sheep, Domestic genetics
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In this study, the genetic relationship and the population structure of western Mediterranean basin native sheep breeds are investigated, analyzing Maghrebian, Central Italian, and Venetian sheep with a highly informative microsatellite markers panel. The phylogeographical analysis, between breeds' differentiation level (Wright's fixation index), gene flow, ancestral relatedness measured by molecular coancestry, genetic distances, divergence times estimates and structure analyses, were revealed based on the assessment of 975 genotyped animals. The results unveiled the past introduction and migration history of sheep in the occidental Mediterranean basin since the early Neolithic. Our findings provided a scenario of three westward sheep migration phases fitting properly to the westward Neolithic expansion argued by zooarcheological, historical and human genetic studies.
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- 2022
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16. First Report of Two Jaculus Rodents as Potential Reservoir Hosts of Leishmania Parasites in Tunisia.
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Ghawar W, Chaouch M, Ben Salah A, Snoussi MA, Salem S, Kharroubi G, Chouchen S, Bouaoun A, Laouini D, Bettaieb J, and Ben Abderrazak S
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This study shows, for the first time, natural Leishmania infection among Jaculus spp. in an endemic region of Tataouine, South Tunisia. To better characterize the transmission cycles in this complex focus of mixed transmission, Leishmania detection and species identification were performed by direct examination, internal transcribed spacer-1 (ITS1)-PCR-restriction fragment length polymorphism (RFLP), and sequencing of Jaculus ( J .) jaculus (Linnaeus, 1758) and J . hirtipes (Lichtenstein, 1823) rodent species, which are frequently encountered in this area. Leishmania parasites were observed in 19 (41.3%) smears, while DNA parasites were detected in 28 (60.9%) Jaculus spp. spleens; among them, 12 (54.5%) were from 22 J . jaculus individuals and 16 (66.7%) were from 24 J . hirtipes individuals. Leishmania parasites were confirmed as Leishmania ( L .) killicki (syn. L . tropica ) in two J . hirtipes individuals (4.3%) and L . major (n = 24; 52.2%) in 10 J. jaculus and 14 J. hirtipes individuals. This finding represents the first evidence of natural infection with Leishmania parasites in rodents belonging to the Jaculus genus, providing the rationale to consider them as potential reservoir hosts of Old World Leishmania parasites in Tunisia and North Africa.
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- 2022
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17. Evaluation of the Taxonomic Status of Lesser Egyptian Jerboa, Jaculus jaculus : First Description of New Phylogroups in Tunisia.
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Ghawar W, Chaouch M, Ben Abderrazak S, Snoussi MA, Salem S, Chouchen S, Bouaoun A, Ben Salah A, and Bettaieb J
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The taxonomy of the Lesser Egyptian jerboa, Jaculus ( J .) jaculus (Dipodinae subfamily), was recently reevaluated, and the taxonomic status was defined by the presence of two cryptic species, J . jaculus (Linnaeus 1758) and J . hirtipes (Lichtenstein, 1823), with a higher genetic divergence in the sympatric North African populations than in other studied parapatric populations. Using phylogenetic analysis of the cytochrome b ( Cytb ) gene from 46 specimens, we confirmed the new status in Tunisia; rodents were collected from two different biotopes belonging to the same locality at the ecological level (mountainous vs. Saharan) in the south of the country. The study of the eye lens weight of these specimens allowed the definition of a cutoff value (58.5 g), categorizing juveniles from adults. Moreover, this study confirmed the phylotaxonomic status of J . jaculus in Tunisia, as recently illustrated, into two distinct species, J . jaculus and J . hirtipes , and recorded for the first time the presence of two phylogroups among each of these rodent species. The lack of clear micro-geographical structure and biotope specificity between the two rodent species and their phylogroups was also highlighted.
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- 2022
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18. African Genomic Medicine Portal: A Web Portal for Biomedical Applications.
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Othman H, Zass L, da Rocha JEB, Radouani F, Samtal C, Benamri I, Kumuthini J, Fakim YJ, Hamdi Y, Mezzi N, Boujemaa M, Okeke CJ, Tendwa MB, Sanak K, Chaouch M, Panji S, Kefi R, Sallam RM, Ghoorah AW, Romdhane L, Kiran A, Meintjes AP, Maturure P, Jmel H, Ksouri A, Azzouzi M, Farahat MA, Ahmed S, Sibira R, Turkson MEE, Ssekagiri A, Parker Z, Fadlelmola FM, Ghedira K, Mulder N, and Kamal Kassim S
- Abstract
Genomics data are currently being produced at unprecedented rates, resulting in increased knowledge discovery and submission to public data repositories. Despite these advances, genomic information on African-ancestry populations remains significantly low compared with European- and Asian-ancestry populations. This information is typically segmented across several different biomedical data repositories, which often lack sufficient fine-grained structure and annotation to account for the diversity of African populations, leading to many challenges related to the retrieval, representation and findability of such information. To overcome these challenges, we developed the African Genomic Medicine Portal (AGMP), a database that contains metadata on genomic medicine studies conducted on African-ancestry populations. The metadata is curated from two public databases related to genomic medicine, PharmGKB and DisGeNET. The metadata retrieved from these source databases were limited to genomic variants that were associated with disease aetiology or treatment in the context of African-ancestry populations. Over 2000 variants relevant to populations of African ancestry were retrieved. Subsequently, domain experts curated and annotated additional information associated with the studies that reported the variants, including geographical origin, ethnolinguistic group, level of association significance and other relevant study information, such as study design and sample size, where available. The AGMP functions as a dedicated resource through which to access African-specific information on genomics as applied to health research, through querying variants, genes, diseases and drugs. The portal and its corresponding technical documentation, implementation code and content are publicly available.
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- 2022
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19. Ten simple rules for developing bioinformatics capacity at an academic institution.
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Aron S, Jongeneel CV, Chauke PA, Chaouch M, Kumuthini J, Zass L, Radouani F, Kassim SK, Fadlelmola FM, and Mulder N
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- Africa, Computational Biology methods, Data Interpretation, Statistical, Diffusion of Innovation, Genomics, Humans, International Cooperation, National Institutes of Health (U.S.), Schools, Software, United States, Computational Biology education, Computational Biology organization & administration, Universities
- Abstract
Competing Interests: The authors have declared that no competing interests exist.
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- 2021
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20. Data Management Plans in the genomics research revolution of Africa: Challenges and recommendations.
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Fadlelmola FM, Zass L, Chaouch M, Samtal C, Ras V, Kumuthini J, Panji S, and Mulder N
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- Africa, Genomics, Humans, Research Design, Biomedical Research, Data Management
- Abstract
Drafting and writing a data management plan (DMP) is increasingly seen as a key part of the academic research process. A DMP is a document that describes how a researcher will collect, document, describe, share, and preserve the data that will be generated as part of a research project. The DMP illustrates the importance of utilizing best practices through all stages of working with data while ensuring accessibility, quality, and longevity of the data. The benefits of writing a DMP include compliance with funder and institutional mandates; making research more transparent (for reproduction and validation purposes); and FAIR (findable, accessible, interoperable, reusable); protecting data subjects and compliance with the General Data Protection Regulation (GDPR) and/or local data protection policies. In this review, we highlight the importance of a DMP in modern biomedical research, explaining both the rationale and current best practices associated with DMPs. In addition, we outline various funders' requirements concerning DMPs and discuss open-source tools that facilitate the development and implementation of a DMP. Finally, we discuss DMPs in the context of African research, and the considerations that need to be made in this regard., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)
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- 2021
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21. H3ABioNet genomic medicine and microbiome data portals hackathon proceedings.
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Fadlelmola FM, Ghedira K, Hamdi Y, Hanachi M, Radouani F, Allali I, Kiran A, Zass L, Alsayed N, Fassatoui M, Samtal C, Ahmed S, Da Rocha J, Chaqsare S, Sallam RM, Chaouch M, Farahat M, Ssekagiri A, Parker Z, Adil M, Turkson M, Benchaalia A, Benkahla A, Panji S, Kassim S, Souiai O, and Mulder N
- Subjects
- Databases, Factual, Genome, Genomics, Humans, Computational Biology, Microbiota genetics
- Abstract
African genomic medicine and microbiome datasets are usually not well characterized in terms of their origin, making it difficult to find and extract data for specific African ethnic groups or even countries. The Pan-African H3Africa Bioinformatics Network (H3ABioNet) recognized the need for developing data portals for African genomic medicine and African microbiomes to address this and ran a hackathon to initiate their development. The two portals were designed and significant progress was made in their development during the hackathon. All the participants worked in a very synergistic and collaborative atmosphere in order to achieve the hackathon's goals. The participants were divided into content and technical teams and worked over a period of 6 days. In response to one of the survey questions of what the participants liked the most during the hackathon, 55% of the hackathon participants highlighted the familial and friendly atmosphere, the team work and the diversity of team members and their expertise. This paper describes the preparations for the portals hackathon and the interaction between the participants and reflects upon the lessons learned about its impact on successfully developing the two data portals as well as building scientific expertise of younger African researchers. Database URL: The code for developing the two portals was made publicly available in GitHub repositories: [https://github.com/codemeleon/Database; https://github.com/codemeleon/AfricanMicrobiomePortal]., (© The Author(s) 2021. Published by Oxford University Press.)
- Published
- 2021
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22. Investigation of natural infection of Phlebotomine (Diptera: Psychodidae) by Leishmania in Tunisian endemic regions.
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Chaouch M, Chaabane A, Ayari C, Ben Othman S, Sereno D, Chemkhi J, and BenAbderrazak S
- Abstract
Leishmaniases are caused by protozoan parasites of the genus Leishmania transmitted by females blood-feeding phlebotomine insects (Diptera: Psychodidae). In Tunisia, cutaneous and visceral leishmaniases are of public health concern. In Tunisia, 17 species of phlebotomine sand flies are described. Here we investigate natural infection in Tunisian mixed foci regions of leishmaniases. We trap female sandflies during the Leishmania transmission season in the country's central-eastern and northern parts. We investigate Leishmania infection using PCR-RFLP targeting the ITS1 ribosomal DNA, followed by enzymatic digestion with Hae III; then, we identify sand flies using molecular methodologies. We confirm the presence of Phlebotomus papatasi and Phlebotomus perniciosus infected by L. major and L. infantum parasites in Tunisia., Competing Interests: The authors have declared that no competing interests exist., (© 2021 The Authors. Published by Elsevier Ltd on behalf of World Federation of Parasitologists.)
- Published
- 2021
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23. Human OMICs and Computational Biology Research in Africa: Current Challenges and Prospects.
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Hamdi Y, Zass L, Othman H, Radouani F, Allali I, Hanachi M, Okeke CJ, Chaouch M, Tendwa MB, Samtal C, Mohamed Sallam R, Alsayed N, Turkson M, Ahmed S, Benkahla A, Romdhane L, Souiai O, Tastan Bishop Ö, Ghedira K, Mohamed Fadlelmola F, Mulder N, and Kamal Kassim S
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- Africa, Ecosystem, Genomics, Humans, Biomedical Research, Computational Biology
- Abstract
Following the publication of the first human genome, OMICs research, including genomics, transcriptomics, proteomics, and metagenomics, has been on the rise. OMICs studies revealed the complex genetic diversity among human populations and challenged our understandings of genotype-phenotype correlations. Africa, being the cradle of the first modern humans, is distinguished by a large genetic diversity within its populations and rich ethnolinguistic history. However, the available human OMICs tools and databases are not representative of this diversity, therefore creating significant gaps in biomedical research. African scientists, students, and publics are among the key contributors to OMICs systems science. This expert review examines the pressing issues in human OMICs research, education, and development in Africa, as seen through a lens of computational biology, public health relevant technology innovation, critically-informed science governance, and how best to harness OMICs data to benefit health and societies in Africa and beyond. We underscore the disparities between North and Sub-Saharan Africa at different levels. A harmonized African ethnolinguistic classification would help address annotation challenges associated with population diversity. Finally, building on the existing strategic research initiatives, such as the H3Africa and H3ABioNet Consortia, we highly recommend addressing large-scale multidisciplinary research challenges, strengthening research collaborations and knowledge transfer, and enhancing the ability of African researchers to influence and shape national and international research, policy, and funding agendas. This article and analysis contribute to a deeper understanding of past and current challenges in the African OMICs innovation ecosystem, while also offering foresight on future innovation trajectories.
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- 2021
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24. A review of clinical pharmacogenetics Studies in African populations.
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Radouani F, Zass L, Hamdi Y, Rocha JD, Sallam R, Abdelhak S, Ahmed S, Azzouzi M, Benamri I, Benkahla A, Bouhaouala-Zahar B, Chaouch M, Jmel H, Kefi R, Ksouri A, Kumuthini J, Masilela P, Masimirembwa C, Othman H, Panji S, Romdhane L, Samtal C, Sibira R, Ghedira K, Fadlelmola F, Kassim SK, and Mulder N
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- Clinical Trials as Topic, Genetic Association Studies, Humans, Black People genetics, Pharmacogenomic Variants
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Effective interventions and treatments for complex diseases have been implemented globally, however, coverage in Africa has been comparatively lower due to lack of capacity, clinical applicability and knowledge on the genetic contribution to disease and treatment. Currently, there is a scarcity of genetic data on African populations, which have enormous genetic diversity. Pharmacogenomics studies have the potential to revolutionise treatment of diseases, therefore, African populations are likely to benefit from these approaches to identify likely responders, reduce adverse side effects and optimise drug dosing. This review discusses clinical pharmacogenetics studies conducted in African populations, focusing on studies that examined drug response in complex diseases relevant to healthcare. Several pharmacogenetics associations have emerged from African studies, as have gaps in knowledge.
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- 2020
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25. Proposed minimum information guideline for kidney disease-research and clinical data reporting: a cross-sectional study.
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Kumuthini J, van Woerden C, Mallett A, Zass L, Chaouch M, Thompson M, Johnston K, Mbiyavanga M, Baichoo S, Mungloo-Dilmohamud Z, Patel C, and Mulder N
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- Biomedical Research standards, Humans, Reproducibility of Results, Research Design, Guidelines as Topic standards, Kidney Diseases therapy, Nephrology standards, Translational Research, Biomedical standards
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Objective: This project aimed to develop and propose a standardised reporting guideline for kidney disease research and clinical data reporting, in order to improve kidney disease data quality and integrity, and combat challenges associated with the management and challenges of 'Big Data'., Methods: A list of recommendations was proposed for the reporting guideline based on the systematic review and consolidation of previously published data collection and reporting standards, including PhenX measures and Minimal Information about a Proteomics Experiment (MIAPE). Thereafter, these recommendations were reviewed by domain-specialists using an online survey, developed in Research Electronic Data Capture (REDCap). Following interpretation and consolidation of the survey results, the recommendations were mapped to existing ontologies using Zooma, Ontology Lookup Service and the Bioportal search engine. Additionally, an associated eXtensible Markup Language schema was created for the REDCap implementation to increase user friendliness and adoption., Results: The online survey was completed by 53 respondents; the majority of respondents were dual clinician-researchers (57%), based in Australia (35%), Africa (33%) and North America (22%). Data elements within the reporting standard were identified as participant-level, study-level and experiment-level information, further subdivided into essential or optional information., Conclusion: The reporting guideline is readily employable for kidney disease research projects, and also adaptable for clinical utility. The adoption of the reporting guideline in kidney disease research can increase data quality and the value for long-term preservation, ensuring researchers gain the maximum benefit from their collected and generated data., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2019. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)
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- 2019
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26. Development and Assessment of Leishmania major and Leishmania tropica Specific Loop-Mediated Isothermal Amplification Assays for the Diagnosis of Cutaneous Leishmaniasis in Tunisia.
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Chaouch M, Aoun K, Ben Othman S, Ben Abid M, Ben Sghaier I, Bouratbine A, and Ben Abderrazak S
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- Humans, Leishmaniasis, Cutaneous parasitology, Neglected Diseases diagnosis, Neglected Diseases epidemiology, Neglected Diseases parasitology, Nucleic Acid Amplification Techniques, Species Specificity, Tunisia epidemiology, Leishmania major genetics, Leishmania tropica genetics, Leishmaniasis, Cutaneous diagnosis, Leishmaniasis, Cutaneous epidemiology
- Abstract
Cutaneous leishmaniasis (CL) remains one of the world's most prevalent neglected diseases, particularly in developing countries. Identification of the involved Leishmania species is an important step in the diagnosis and case management process. In this study, we tested simple, rapid, and highly sensitive loop-mediated isothermal amplification (LAMP) assays for Leishmania DNA species-specific detection from cutaneous lesions. Two LAMP assays, targeting cysteine protease B (cpb) gene, were developed to detect and identify Leishmania major and Leishmania tropica species. Loop-mediated isothermal amplification specificity was examined using DNA samples from other Leishmania species and Trypanosoma species. No cross-reactions were detected. The developed LAMP assays exhibited sensitivity with a detection limit of 20 fg and 200 fg for L. major and L. tropica , respectively. Both tests were applied on clinical samples of CL suspected patients living in endemic Tunisian regions and compared with kinetoplast DNA quantitative PCR (qPCR), microscopic, and conventional cpb-based polymerase chain reaction (PCR) assays. Our LAMP tests were able to discriminate between L. major and L. tropica species and showed a sensitivity of 84% and a specificity of 100%. However, when compared with the performance of the diagnostic tests with latent class analysis (LCA), our LAMP assays show a sensitivity of 100%. These assays can be used as a first-line molecular test for early diagnosis and prompt management of CL cases in public health programs.
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- 2019
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27. Extraction of Essential Oils of Rosmarinus officinalis L. by Two Different Methods: Hydrodistillation and Microwave Assisted Hydrodistillation.
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Elyemni M, Louaste B, Nechad I, Elkamli T, Bouia A, Taleb M, Chaouch M, and Eloutassi N
- Abstract
The extraction of essential oils is generally carried out by two main techniques: azeotropic distillation (hydrodistillation, hydrodiffusion, and steam distillation) and extraction with solvents. However, these traditional methods are a bit expensive, especially since they are extremely energy and solvent consuming. This work consists in studying two methods of extraction of the essential oils of Rosmarinus officinalis L.: microwave assisted hydrodistillation (MAH) and Clevenger hydrodistillation (CH). Several parameters have been studied: the extraction time, the yield, and the chemical composition of the essential oils as well as the efficiency and cost of each procedure. The results obtained revealed that microwave-assisted hydrodistillation makes it possible to minimize the extraction time of the essential oils in comparison with conventional hydrodistillation. Thus, the same yield of essential oils is obtained for 20 minutes only with MAH while it takes 180 minutes with CH. In addition, the quality of the essential oil is improved thanks to a 1.14% increase in oxygenates. In conclusion, the MAH method offers significant advantages over conventional hydrodistillation and can therefore replace it on a pilot and industrial scale.
- Published
- 2019
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28. Development and Evaluation of a Loop-mediated Isothermal Amplification Assay for Rapid Detection of Theileria annulata Targeting the Cytochrome B Gene.
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Chaouch M, Mhadhbi M, Limam S, Darghouth MA, and Benabderrazak S
- Abstract
Background: Theileria annulata is an economically important cattle disease in North Africa that occurs in subtropical and tropical areas. Accurate and rapid, molecular diagnosis of tropical theileriosis is an important issue that allows early treatment and, prevents transmission. We developed and validated a Theileria annulata specific LAMP assay targeting the cytochrome b multicopy gene, in order to increase the DNA detection sensitivity., Methods: The methodology was used to evaluate the occurrences of T. annulata in 88 field samples collected in Northern Tunisia during 2013-2014. The specificity and sensitivity of the LAMP assays were compared to conventional cytochrome b PCR and routine microscopy commonly used on naturally infected cattle blood samples., Results: The PCR assay showed a sensitivity of 70% and specificity around 75%. Our LAMP assay showed a suitable sensitivity 78.7% and specificity 87.5%, with, however, positive (98.4%) and negative (29.1%) predictive values., Conclusion: The LAMP assay is a simple and convenient diagnostic tool for tropical theileriosis. Moreover, LAMP does not require experienced staff and specialized equipment for sampling procedures and it is practical outside laboratories and can be used for field diagnosis., Competing Interests: Conflicts of interest The authors declare that there is no conflict of interest.
- Published
- 2018
29. Greater improvement in LRRK2 G2019S patients undergoing Subthalamic Nucleus Deep Brain Stimulation compared to non-mutation carriers.
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Sayad M, Zouambia M, Chaouch M, Ferrat F, Nebbal M, Bendini M, Lesage S, Brice A, Brahim Errahmani M, and Asselah B
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- Female, Humans, Leucine-Rich Repeat Serine-Threonine Protein Kinase-2, Male, Middle Aged, Parkinson Disease surgery, Treatment Outcome, Deep Brain Stimulation, Mutation, Parkinson Disease genetics, Parkinson Disease therapy, Protein Serine-Threonine Kinases genetics, Subthalamic Nucleus physiopathology
- Abstract
Background: Bilateral subthalamic nucleus deep brain stimulation (STN-DBS) of parkinson's disease (PD) patients has demonstrated to improve motor performance and to reduce dopa-induced dyskinesia. An association between the occurrence of dyskinesias and LRRK2 (leucine-rich repeat kinase 2) G2019S gene mutations has recently been suggested. The aim of this study is to discover the impact of the G2019S mutation (with high incidence in the authors' native Algeria) on the symptom response of PD in patients who underwent STN-DBS., Methods: We carried out a comparative statistical study for the clinical evaluation and neuropsychological assessment of 27 Algerian PD STN-DBS patients, both G2019S mutation carriers (MC) and non-carriers (NC). A multiple correspondence analysis (MCA) was then conducted to compare the results with those from groups of individuals with similar modalities., Results: The MCA revealed that MC and NC PD patients showed two different patterns of clinical evaluations. The group of idiopathic patients showed some differences compared to the clinical evaluations, depending on gender. No association was found between the G2019S mutation and the Mini Mental State Examination scores (MMSE), and MC patients appeared more susceptible to dyskinesia than NC patients. In NC patients, we found two cases with Parkin mutations who had a different "honeymoon" period and different initial symptoms. The results showed considerable improvement of motor unified parkinson's disease rating scale III (UPDRS-III) in a situation of stimulation without medication in the MC patients with a percentage of improvement (51.1 %) over the required 30 % compared to the NC patients (25.5 %). The same result was observed for the Schwab and England's activities of daily living scale (S and E scale), which thus demonstrated a greater effectiveness of DBS for MC patients than for NC patients. However, the Hoehn and Yahr scale (H and Y Scale) showed the same significance in a situation of stimulation for MC and NC patients. In this later group, the best scores of UPDRS-III were observed for patients with the Parkin mutation before they underwent surgery., Conclusions: This study shows that surgical treatment probably has a more significant impact on LRRK2 G2019S MC than on idiopathic patients.
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- 2016
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30. Familial epilepsy in Algeria: Clinical features and inheritance profiles.
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Chentouf A, Dahdouh A, Guipponi M, Oubaiche ML, Chaouch M, Hamamy H, and Antonarakis SE
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- Adolescent, Adult, Age of Onset, Algeria epidemiology, Child, Child, Preschool, Epilepsy genetics, Epilepsy physiopathology, Epilepsy therapy, Family, Female, Humans, Male, Middle Aged, Pedigree, Prospective Studies, Seizures epidemiology, Seizures genetics, Seizures physiopathology, Seizures therapy, Treatment Outcome, Young Adult, Epilepsy epidemiology
- Abstract
Purpose: To document the clinical characteristics and inheritance pattern of epilepsy in multigeneration Algerian families., Methods: Affected members from extended families with familial epilepsy were assessed at the University Hospital of Oran in Algeria. Available medical records, neurological examination, electroencephalography and imaging data were reviewed. The epilepsy type was classified according to the criteria of the International League Against Epilepsy and modes of inheritance were deduced from pedigree analysis., Results: The study population included 40 probands; 23 male (57.5%) and 17 female subjects (42.5%). The mean age of seizure onset was 9.5 ± 6.1 years. According to seizure onset, 16 patients (40%) had focal seizures and 20 (50%) had generalized seizures. Seizure control was achieved for two patients (5%) for 10 years, while 28 (70%) were seizure-free for 3 months. Eleven patients (27.5%) had prior febrile seizures, 12 were diagnosed with psychiatric disorders and four families had syndromic epilepsy. The consanguinity rate among parents of affected was 50% with phenotypic concordance observed in 25 families (62.5%). Pedigree analysis suggested autosomal dominant (AD) inheritance with or without reduced penetrance in 18 families (45%), probable autosomal recessive (AR) inheritance in 14 families (35%), and an X-linked recessive inheritance in one family., Conclusion: This study reveals large Algerian families with multigenerational inheritance of epilepsy. Molecular testing such as exome sequencing would clarify the genetic basis of epilepsy in some of our families., (Copyright © 2015 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.)
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- 2015
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31. Molecular and clinical study of a cohort of 110 Algerian patients with autosomal recessive ataxia.
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Hamza W, Ali Pacha L, Hamadouche T, Muller J, Drouot N, Ferrat F, Makri S, Chaouch M, Tazir M, Koenig M, and Benhassine T
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- Adolescent, Adult, Algeria epidemiology, Cerebellar Ataxia epidemiology, Child, Child, Preschool, Cohort Studies, Female, Genomics, Humans, Infant, Infant, Newborn, Inheritance Patterns, Male, Mutation, Phenotype, Young Adult, Cerebellar Ataxia genetics
- Abstract
Background: Autosomal recessive cerebellar ataxias (ARCA) are a complex group of neurodegenerative disorders with great genetic and phenotypic heterogeneity, over 30 genes/loci have been associated with more than 20 different clinical forms of ARCA. Genetic heterogeneity combined with highly variable clinical expression of the cerebellar symptoms and overlapping features complicate furthermore the etiological diagnosis of ARCA. The determination of the most frequent mutations and corresponding ataxias, as well as particular features specific to a population, are mandatory to facilitate and speed up the diagnosis process, especially when an appropriate treatment is available., Methods: We explored 166 patients (115 families) refered to the neurology units of Algiers central hospitals (Algeria) with a cerebellar ataxia phenotype segregating as an autosomal recessive pattern of inheritance. Genomic DNA was extracted from peripheral blood samples and mutational screening was performed by PCR and direct sequencing or by targeted genomic capture and massive parallel sequencing of 57 genes associated with inherited cerebellar ataxia phenotypes., Results: In this work we report the clinical and molecular results obtained on a large cohort of Algerian patients (110 patients/76 families) with genetically determined autosomal recessive ataxia, representing 9 different types of ARCA and 23 different mutations, including 6 novel ones. The five most common ARCA in this cohort were Friedreich ataxia, ataxia with isolated vitamin E deficiency, ataxia with oculomotor apraxia type 2, autosomal recessive spastic ataxia of Charlevoix-Saguenay and ataxia with oculomotor apraxia type 1., Conclusion: We report here a large cohort of patients with genetically determined autosomal recessive ataxia and the first study of the genetic context of ARCA in Algeria. This study showed that in Algerian patients, the two most common types of ataxia (Friedreich ataxia and ataxia with isolated vitamin E deficiency) coexist with forms that may be less common or underdiagnosed. To refine the genotype/phenotype correlation in rare and heteregeneous diseases as autosomal recessive ataxias, more extensive epidemiological investigations and reports are necessary as well as more accurate and detailed clinical characterizations. The use of standardized clinical and molecular protocols would thus enable a better knowledge of the different forms of ARCA.
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- 2015
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32. Sequence Polymorphism of Cytochrome b Gene in Theileria annulata Tunisian Isolates and Its Association with Buparvaquone Treatment Failure.
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Mhadhbi M, Chaouch M, Ajroud K, Darghouth MA, and BenAbderrazak S
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- Animals, Antiprotozoal Agents pharmacology, Cattle, Naphthoquinones pharmacology, Point Mutation, Theileria annulata drug effects, Theileria annulata isolation & purification, Theileriasis drug therapy, Theileriasis parasitology, Treatment Failure, Antiprotozoal Agents therapeutic use, Cytochromes b genetics, Drug Resistance, Naphthoquinones therapeutic use, Polymorphism, Single Nucleotide, Protozoan Proteins genetics, Theileria annulata genetics
- Abstract
Background: Buparvaquone (BW 720C) is the major hydroxynaphtoquinone active against tropical theileriosis (Theileria annulata infection). Previous studies showed that buparvaquone, similarly to others hydroxynaphtoquinone, probably acts by binding to cytochrome b (cyt b) inhibiting the electron transport chain in the parasite. Several observations suggested that T. annulata is becoming resistant to buparvaquone in many endemic regions (Tunisia, Turkey and Iran), which may hinder the development of bovine livestock in these areas., Methodology/principal Findings: In the present study we sought to determine whether point mutations in T. annulata cytochrome b gene could be associated to buparvaquone resistance. A total of 28 clones were studied in this work, 19 of which were obtained from 3 resistant isolates (ST2/12, ST2/13 and ST2/19) collected at different time after treatment, from a field treatment failure and nine clones isolated from 4 sensitive stocks of T. annulata (Beja, Battan, Jed4 and Sousse). The cytochrome b gene was amplified and sequenced. We identified five point mutations at the protein sequences (114, 129, 253, 262 and 347) specific for the clones isolated from resistant stocks. Two of them affecting 68% (13/19) of resistant clones, are present in the drug-binding site Q02 region at the position 253 in three resistant clones and at the position 262 in 11 out of 19 resistant clones. These two mutations substitute a neutral and hydrophobic amino acids by polar and hydrophilic ones which could interfere with the drug binding capabilities. When we compared our sequences to the Iranian ones, the phylogenetic tree analyses show the presence of a geographical sub-structuring in the population of T. annulata., Conclusions/significance: Taken together, our results suggest that the cytochrome b gene may be used as a tool to discriminate between different T. annulata genotypes and also as a genetic marker to characterize resistant isolates of T. annulata.
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- 2015
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33. Galanin pathogenic mutations in temporal lobe epilepsy.
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Guipponi M, Chentouf A, Webling KE, Freimann K, Crespel A, Nobile C, Lemke JR, Hansen J, Dorn T, Lesca G, Ryvlin P, Hirsch E, Rudolf G, Rosenberg DS, Weber Y, Becker F, Helbig I, Muhle H, Salzmann A, Chaouch M, Oubaiche ML, Ziglio S, Gehrig C, Santoni F, Pizzato M, Langel Ü, and Antonarakis SE
- Subjects
- Adult, Animals, Base Sequence, CHO Cells, Cricetinae, Cricetulus, DNA Mutational Analysis, Genetic Association Studies, Humans, Mutation, Missense, Pedigree, Protein Binding, Signal Transduction, Epilepsy, Temporal Lobe genetics, Galanin genetics
- Abstract
Temporal lobe epilepsy (TLE) is a common epilepsy syndrome with a complex etiology. Despite evidence for the participation of genetic factors, the genetic basis of TLE remains largely unknown. A role for the galanin neuropeptide in the regulation of epileptic seizures has been established in animal models more than two decades ago. However, until now there was no report of pathogenic mutations in GAL, the galanin-encoding gene, and therefore its role in human epilepsy was not established. Here, we studied a family with a pair of monozygotic twins affected by TLE and two unaffected siblings born to healthy parents. Exome sequencing revealed that both twins carried a novel de novo mutation (p.A39E) in the GAL gene. Functional analysis revealed that the p.A39E mutant showed antagonistic activity against galanin receptor 1 (GalR1)-mediated response, and decreased binding affinity and reduced agonist properties for GalR2. These findings suggest that the p.A39E mutant could impair galanin signaling in the hippocampus, leading to increased glutamatergic excitation and ultimately to TLE. In a cohort of 582 cases, we did not observe any pathogenic mutations indicating that mutations in GAL are a rare cause of TLE. The identification of a novel de novo mutation in a biologically-relevant candidate gene, coupled with functional evidence that the mutant protein disrupts galanin signaling, strongly supports GAL as the causal gene for the TLE in this family. Given the availability of galanin agonists which inhibit seizures, our findings could potentially have direct implications for the development of anti-epileptic treatment., (© The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)
- Published
- 2015
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34. Phenotypic spectrum and prevalence of INPP5E mutations in Joubert syndrome and related disorders.
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Travaglini L, Brancati F, Silhavy J, Iannicelli M, Nickerson E, Elkhartoufi N, Scott E, Spencer E, Gabriel S, Thomas S, Ben-Zeev B, Bertini E, Boltshauser E, Chaouch M, Cilio MR, de Jong MM, Kayserili H, Ogur G, Poretti A, Signorini S, Uziel G, Zaki MS, Johnson C, Attié-Bitach T, Gleeson JG, and Valente EM
- Subjects
- Abnormalities, Multiple, Adolescent, Amino Acid Sequence, Cerebellar Diseases diagnosis, Cerebellum abnormalities, Child, Child, Preschool, Ciliary Motility Disorders diagnosis, Ciliary Motility Disorders genetics, Encephalocele diagnosis, Encephalocele genetics, Eye Abnormalities diagnosis, Female, Heterozygote, Humans, Infant, Kidney Diseases, Cystic diagnosis, Male, Molecular Sequence Data, Pedigree, Polycystic Kidney Diseases diagnosis, Polycystic Kidney Diseases genetics, Prenatal Diagnosis, Prevalence, Retinitis Pigmentosa, Cerebellar Diseases genetics, Eye Abnormalities genetics, Gene Frequency, Kidney Diseases, Cystic genetics, Mutation, Phenotype, Phosphoric Monoester Hydrolases genetics, Retina abnormalities
- Abstract
Joubert syndrome and related disorders (JSRD) are clinically and genetically heterogeneous ciliopathies sharing a peculiar midbrain-hindbrain malformation known as the 'molar tooth sign'. To date, 19 causative genes have been identified, all coding for proteins of the primary cilium. There is clinical and genetic overlap with other ciliopathies, in particular with Meckel syndrome (MKS), that is allelic to JSRD at nine distinct loci. We previously identified the INPP5E gene as causative of JSRD in seven families linked to the JBTS1 locus, yet the phenotypic spectrum and prevalence of INPP5E mutations in JSRD and MKS remain largely unknown. To address this issue, we performed INPP5E mutation analysis in 483 probands, including 408 JSRD patients representative of all clinical subgroups and 75 MKS fetuses. We identified 12 different mutations in 17 probands from 11 JSRD families, with an overall 2.7% mutation frequency among JSRD. The most common clinical presentation among mutated families (7/11, 64%) was Joubert syndrome with ocular involvement (either progressive retinopathy and/or colobomas), while the remaining cases had pure JS. Kidney, liver and skeletal involvement were not observed. None of the MKS fetuses carried INPP5E mutations, indicating that the two ciliopathies are not allelic at this locus.
- Published
- 2013
- Full Text
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35. Compound heterozygous ASPM mutations associated with microcephaly and simplified cortical gyration in a consanguineous Algerian family.
- Author
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Saadi A, Borck G, Boddaert N, Chekkour MC, Imessaoudene B, Munnich A, Colleaux L, and Chaouch M
- Subjects
- Algeria, Birth Weight, Child, Family, Female, Haplotypes, Heterozygote, Humans, Intellectual Disability genetics, Male, Microcephaly diagnostic imaging, Pedigree, Radiography, Siblings, Cerebral Cortex abnormalities, Consanguinity, Microcephaly genetics, Mutation, Nerve Tissue Proteins genetics
- Abstract
Homozygous mutations in the ASPM gene are a major cause of autosomal recessive primary microcephaly (MCPH). Here we report on a consanguineous Algerian family in which three out of five children presented with severe microcephaly, simplified cortical gyration, mild to severe mental retardation and low to low-normal birth weight. Given the parental consanguinity with the unaffected parents being third cousins once removed, the most probable pattern of inheritance was autosomal recessive. Linkage and mutational analyses identified compound heterozygous truncating mutations within the ASPM gene segregating with MCPH (c.2389C>T [p.Arg797X] and c.7781_7782delAG [p.Gln2594fsX6]). These results highlight some of the pitfalls of genetic analysis in consanguineous families. They also suggest that low birth weight may be a feature of MCPH, a finding that needs confirmation, and confirm that ASPM mutations are associated with simplified cortical gyration.
- Published
- 2009
- Full Text
- View/download PDF
36. Founder effect and estimation of the age of the c.892C>T (p.Arg298Cys) mutation in LMNA associated to Charcot-Marie-Tooth subtype CMT2B1 in families from North Western Africa.
- Author
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Hamadouche T, Poitelon Y, Genin E, Chaouch M, Tazir M, Kassouri N, Nouioua S, Chaouch A, Boccaccio I, Benhassine T, De Sandre-Giovannoli A, Grid D, Lévy N, and Delague V
- Subjects
- Algeria, Amino Acid Substitution, Female, Homozygote, Humans, Male, Polymorphism, Single Nucleotide, Tandem Repeat Sequences, Time Factors, Charcot-Marie-Tooth Disease genetics, Founder Effect, Lamin Type A genetics, Mutation, Missense
- Abstract
CMT2B1, an axonal subtype (MIM 605588) of the Charcot-Marie-Tooth disease, is an autosomal recessive motor and sensory neuropathy characterized by progressive muscular and sensory loss in the distal extremities with chronic distal weakness. The genetic defect associated with the disease is, to date, a unique homozygous missense mutation, p.Arg298Cys (c.892C>T), in the LMNA gene. So far, this mutation has only been found in affected individuals originating from a restricted region of North Western Africa (northwest of Algeria and east of Morocco), strongly suggesting a founder effect. In order to address this hypothesis, genotyping of both STRs and intragenic SNPs was performed at the LMNA locus, at chromosome 1q21.2-q21.3, in 42 individuals affected with CMT2B1 from 25 Algerian families. Our results indicate that the affected individuals share a common ancestral haplotype in a region of about 1.0 Mb (1 cM) and that the most recent common ancestor would have lived about 800-900 years ago (95% confidence interval: 550 to 1300 years).
- Published
- 2008
- Full Text
- View/download PDF
37. Mutations in FGD4 encoding the Rho GDP/GTP exchange factor FRABIN cause autosomal recessive Charcot-Marie-Tooth type 4H.
- Author
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Delague V, Jacquier A, Hamadouche T, Poitelon Y, Baudot C, Boccaccio I, Chouery E, Chaouch M, Kassouri N, Jabbour R, Grid D, Mégarbané A, Haase G, and Lévy N
- Subjects
- Amino Acid Sequence, Animals, Chromosomes, Human, Pair 12 genetics, Gene Expression, Green Fluorescent Proteins analysis, Green Fluorescent Proteins genetics, Humans, Microfilament Proteins analysis, Molecular Sequence Data, Mutation, Pedigree, Physical Chromosome Mapping, Rats, Schwann Cells enzymology, rho GTP-Binding Proteins genetics, Charcot-Marie-Tooth Disease genetics, Genes, Recessive, Guanine Nucleotide Exchange Factors genetics, Microfilament Proteins genetics
- Abstract
Charcot-Marie-Tooth (CMT) disorders are a clinically and genetically heterogeneous group of hereditary motor and sensory neuropathies characterized by muscle weakness and wasting, foot and hand deformities, and electrophysiological changes. The CMT4H subtype is an autosomal recessive demyelinating form of CMT that was recently mapped to a 15.8-Mb region at chromosome 12p11.21-q13.11, in two consanguineous families of Mediterranean origin, by homozygosity mapping. We report here the identification of mutations in FGD4, encoding FGD4 or FRABIN (FGD1-related F-actin binding protein), in both families. FRABIN is a GDP/GTP nucleotide exchange factor (GEF), specific to Cdc42, a member of the Rho family of small guanosine triphosphate (GTP)-binding proteins (Rho GTPases). Rho GTPases play a key role in regulating signal-transduction pathways in eukaryotes. In particular, they have a pivotal role in mediating actin cytoskeleton changes during cell migration, morphogenesis, polarization, and division. Consistent with these reported functions, expression of truncated FRABIN mutants in rat primary motoneurons and rat Schwann cells induced significantly fewer microspikes than expression of wild-type FRABIN. To our knowledge, this is the first report of mutations in a Rho GEF protein being involved in CMT.
- Published
- 2007
- Full Text
- View/download PDF
38. Homozygosity mapping of autosomal recessive demyelinating Charcot-Marie-Tooth neuropathy (CMT4H) to a novel locus on chromosome 12p11.21-q13.11.
- Author
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De Sandre-Giovannoli A, Delague V, Hamadouche T, Chaouch M, Krahn M, Boccaccio I, Maisonobe T, Chouery E, Jabbour R, Atweh S, Grid D, Mégarbané A, and Lévy N
- Subjects
- Adult, Algeria ethnology, Charcot-Marie-Tooth Disease ethnology, Charcot-Marie-Tooth Disease pathology, Chromosome Mapping, Demyelinating Diseases ethnology, Demyelinating Diseases pathology, Female, Genes, Recessive, Genetic Testing, Humans, Lebanon ethnology, Male, Pedigree, Sural Nerve pathology, Charcot-Marie-Tooth Disease genetics, Chromosomes, Human, Pair 12 genetics, Chromosomes, Human, Pair 13 genetics, Demyelinating Diseases genetics, Homozygote
- Published
- 2005
- Full Text
- View/download PDF
39. Phenotypic variability in autosomal recessive axonal Charcot-Marie-Tooth disease due to the R298C mutation in lamin A/C.
- Author
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Tazir M, Azzedine H, Assami S, Sindou P, Nouioua S, Zemmouri R, Hamadouche T, Chaouch M, Feingold J, Vallat JM, Leguern E, and Grid D
- Subjects
- Adolescent, Adult, Age of Onset, Charcot-Marie-Tooth Disease pathology, Charcot-Marie-Tooth Disease physiopathology, Child, Chromosomes, Human, Pair 1 genetics, Disease Progression, Female, Genes, Recessive, Humans, Male, Median Nerve physiopathology, Nerve Fibers, Myelinated pathology, Nerve Fibers, Unmyelinated pathology, Neural Conduction, Phenotype, Charcot-Marie-Tooth Disease genetics, Lamin Type A genetics, Mutation
- Abstract
Autosomal recessive forms of axonal Charcot-Marie-Tooth (ARCMT2) disease are frequent in some areas, such as North Africa and the Middle East, since consanguineous marriages are still common there. Recently, a unique homozygous mutation in LMNA, which encodes lamin A/C, a component of the nuclear envelope, was identified in members of three Algerian families with ARCMT2 linked to chromosome 1q21.2-q21.3. In the present study we describe a group of 21 ARCMT2 patients from seven unrelated Algerian families with the same R298C mutation in the lamin A/C gene and marked variability of the clinical phenotype. There is a wide range of age of onset, from 6 to 27 years, with a mean of 14.4 +/- 4.6 years. The course of the disease varies considerably from one patient to another. Twelve patients with a disease duration of 10-15 years had a severe CMT phenotype with distal wasting and weakness of all four limbs and areflexia associated with involvement of the proximal lower limb muscles. In contrast, nine patients had the classical CMT phenotype with mild functional disability without proximal lower limb involvement after a disease duration of 5-18 years. Electrophysiological studies showed a median motor nerve conduction velocity (MNCV) in the normal range in almost all the patients. MNCV and compound muscle action potential (CMAP) values were inversely correlated with the disease duration and the MNCV was strictly related to the CMAP, strongly supporting a pure axonal process without a demyelinating component. Six patients had a nerve biopsy, which revealed severe rarefaction of myelinated fibres in all cases and an increased density of unmyelinated fibres in the majority of cases. In conclusion, the ARCMT2 associated with the R298C mutation differs from other types of ARCMT2. The variability among patients in the age of onset and the course of the disease strongly suggests the action of modifying genes, which remain to be identified.
- Published
- 2004
- Full Text
- View/download PDF
40. Phenotypic and genetic exploration of severe demyelinating and secondary axonal neuropathies resulting from GDAP1 nonsense and splicing mutations.
- Author
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De Sandre-Giovannoli A, Chaouch M, Boccaccio I, Bernard R, Delague V, Grid D, Vallat JM, Lévy N, and Mégarbané A
- Subjects
- Alternative Splicing genetics, Axons physiology, Base Sequence, Child, Codon, Nonsense, Consanguinity, DNA chemistry, DNA genetics, DNA Mutational Analysis, DNA, Complementary chemistry, DNA, Complementary genetics, Demyelinating Diseases pathology, Demyelinating Diseases physiopathology, Electrophysiology, Family Health, Female, Genotype, Humans, Male, Microscopy, Electron, Pedigree, Peripheral Nervous System Diseases pathology, Peripheral Nervous System Diseases physiopathology, Peroneal Nerve pathology, Peroneal Nerve ultrastructure, Phenotype, Demyelinating Diseases genetics, Mutation genetics, Nerve Tissue Proteins genetics, Peripheral Nervous System Diseases genetics
- Published
- 2003
- Full Text
- View/download PDF
41. Homozygous defects in LMNA, encoding lamin A/C nuclear-envelope proteins, cause autosomal recessive axonal neuropathy in human (Charcot-Marie-Tooth disorder type 2) and mouse.
- Author
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De Sandre-Giovannoli A, Chaouch M, Kozlov S, Vallat JM, Tazir M, Kassouri N, Szepetowski P, Hammadouche T, Vandenberghe A, Stewart CL, Grid D, and Lévy N
- Subjects
- Algeria, Amino Acid Sequence, Animals, Arginine genetics, Axons ultrastructure, Base Sequence, Charcot-Marie-Tooth Disease classification, Consanguinity, Conserved Sequence, Electrophysiology, Exons genetics, Female, Humans, Lamin Type A, Lamins, Linkage Disequilibrium genetics, Male, Mice, Mice, Knockout, Molecular Sequence Data, Mutation genetics, Nuclear Proteins analysis, Pedigree, Sciatic Nerve pathology, Sciatic Nerve ultrastructure, Axons pathology, Charcot-Marie-Tooth Disease genetics, Charcot-Marie-Tooth Disease pathology, Genes, Recessive genetics, Homozygote, Nuclear Envelope chemistry, Nuclear Proteins genetics
- Abstract
The Charcot-Marie-Tooth (CMT) disorders comprise a group of clinically and genetically heterogeneous hereditary motor and sensory neuropathies, which are mainly characterized by muscle weakness and wasting, foot deformities, and electrophysiological, as well as histological, changes. A subtype, CMT2, is defined by a slight or absent reduction of nerve-conduction velocities together with the loss of large myelinated fibers and axonal degeneration. CMT2 phenotypes are also characterized by a large genetic heterogeneity, although only two genes---NF-L and KIF1Bbeta---have been identified to date. Homozygosity mapping in inbred Algerian families with autosomal recessive CMT2 (AR-CMT2) provided evidence of linkage to chromosome 1q21.2-q21.3 in two families (Zmax=4.14). All patients shared a common homozygous ancestral haplotype that was suggestive of a founder mutation as the cause of the phenotype. A unique homozygous mutation in LMNA (which encodes lamin A/C, a component of the nuclear envelope) was identified in all affected members and in additional patients with CMT2 from a third, unrelated family. Ultrastructural exploration of sciatic nerves of LMNA null (i.e., -/-) mice was performed and revealed a strong reduction of axon density, axonal enlargement, and the presence of nonmyelinated axons, all of which were highly similar to the phenotypes of human peripheral axonopathies. The finding of site-specific amino acid substitutions in limb-girdle muscular dystrophy type 1B, autosomal dominant Emery-Dreifuss muscular dystrophy, dilated cardiomyopathy type 1A, autosomal dominant partial lipodystrophy, and, now, AR-CMT2 suggests the existence of distinct functional domains in lamin A/C that are essential for the maintenance and integrity of different cell lineages. To our knowledge, this report constitutes the first evidence of the recessive inheritance of a mutation that causes CMT2; additionally, we suggest that mutations in LMNA may also be the cause of the genetically overlapping disorder CMT2B1.
- Published
- 2002
- Full Text
- View/download PDF
42. Absence of gamma-sarcoglycan (35 DAG) in autosomal recessive muscular dystrophy linked to chromosome 13q12.
- Author
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Jung D, Leturcq F, Sunada Y, Duclos F, Tomé FM, Moomaw C, Merlini L, Azibi K, Chaouch M, Slaughter C, Fardeau M, Kaplan JC, and Campbell KP
- Subjects
- Animals, Child, Chromosome Mapping, Chromosomes, Human, Pair 13, Dystrophin genetics, Genetic Linkage, Humans, Membrane Glycoproteins analysis, Organ Specificity, Rabbits, Reference Values, Sarcoglycans, Sarcolemma chemistry, Sarcolemma metabolism, Cytoskeletal Proteins, Membrane Glycoproteins deficiency, Membrane Glycoproteins genetics, Muscle, Skeletal metabolism, Muscular Dystrophies genetics
- Abstract
We have partially sequenced rabbit skeletal muscle gamma-sarcoglycan, an integral component of the dystrophin-glycoprotein complex. Specific antibodies were produced against a gamma-sarcoglycan peptide and used to examine the expression of gamma-sarcoglycan in skeletal muscle of patients with severe childhood autosomal muscular dystrophy linked to chromosome 13q12 (SCARMD). We show by immunofluorescence and Western blotting that in skeletal muscle from these patients gamma-sarcoglycan is completely absent and alpha- and beta-sarcoglycan are greatly reduced in abundance, whereas other components of the DGC are preserved. In addition, we show that in normal muscle alpha-, beta-, and gamma-sarcoglycan constitute a tightly associated sarcolemma complex which cannot be disrupted by SDS treatment.
- Published
- 1996
- Full Text
- View/download PDF
43. Deficiency of the 50K dystrophin-associated glycoprotein in severe childhood autosomal recessive muscular dystrophy.
- Author
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Matsumura K, Tomé FM, Collin H, Azibi K, Chaouch M, Kaplan JC, Fardeau M, and Campbell KP
- Subjects
- Biopsy, Child, Cytoskeletal Proteins isolation & purification, Dystroglycans, Electrophoresis, Polyacrylamide Gel, Humans, Molecular Weight, Muscles chemistry, Muscles pathology, Muscular Dystrophies pathology, Muscular Dystrophies physiopathology, Necrosis, Sarcolemma chemistry, Cytoskeletal Proteins deficiency, Dystrophin isolation & purification, Genes, Recessive, Membrane Glycoproteins, Muscular Dystrophies genetics
- Abstract
X-linked recessive Duchenne muscular dystrophy (DMD) is caused by the absence of dystrophin, a membrane cytoskeletal protein. Dystrophin is associated with a large oligomeric complex of sarcolemmal glycoprotein. The dystrophin-glycoprotein complex has been proposed to span the sarcolemma to provide a link between the subsarcolemmal cytoskeleton and the extracellular matrix component, laminin. In DMD, the absence of dystrophin leads to a large reduction in all of the dystrophin-associated protein. We have investigated the possibility that a deficiency of a dystrophin-associated protein could be the cause of severe childhood autosomal recessive muscular dystrophy (SCARMD) with a DMD-like phenotype. Here we report the specific deficiency of the 50K dystrophin-associated glycoprotein (M(r) 50,000) in sarcolemma of SCARMD patients. Therefore, the loss of this glycoprotein is a common denominator of the pathological process leading to muscle cell necrosis in two forms of muscular dystrophy, DMD and SCARMD.
- Published
- 1992
- Full Text
- View/download PDF
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