40 results on '"Thabet Y"'
Search Results
2. Endothelial dysfunction is the key of long COVID-19 symptoms: The results of TUN-EndCOV study
- Author
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Charfeddine, S., primary, Ibnhadjamor, H., additional, Torjmen, S., additional, Kraiem, S., additional, Hammami, R., additional, Bahloul, A., additional, Kallel, N., additional, Moussa, N., additional, Touil, I., additional, Milouchi, S., additional, Elghoul, J., additional, Meddeb, Z., additional, Thabet, Y., additional, Jdidi, J., additional, Bouslema, K., additional, Abdesselem, S., additional, and Abid, L., additional
- Published
- 2022
- Full Text
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3. Tracheal Injuries After Blunt Chest Trauma: Rare Cases
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Aqeel Chaudhry, Ahsan Iqbal Cheema, Thabet Y Alghazal, Sama M Al Sulaiman, Yousif A Al Qahtani, Safa Al Zayed, Suha Albader, and Ikram Chaudhry
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medicine.medical_specialty ,Respiratory distress ,medicine.diagnostic_test ,business.industry ,Stridor ,Computed tomography ,respiratory system ,Surgery ,Road traffic accident ,Blunt ,medicine ,Femur ,medicine.symptom ,Airway ,business ,Subcutaneous emphysema - Abstract
Airway injuries due to blunt chest trauma are rare but life threatening. We herein report two cases of tracheal injuries due to road traffic accident. Both patients were intubated and mechanically ventilated and transferred to our tertiary care hospital for surgical repair. A 20-year-old male was ejected out of car and sustained fracture of femur which was fixed under spinal anaesthesia and later after two months he presented with shortness of breath and stridor he was endotracheally intubated and mechanically ventilated. His computed tomographic scan of chest (CT) showed stricture of intrathoracic trachea. Second case was 35- year-old female front seat passenger sustained neck injury in road traffic accident. She presented with cervical subcutaneous emphysema and respiratory distress. She was intubated and mechanically ventilated. Her CT scan of chest showed fracture of first tracheal ring. Both patients were operated with uneventful postoperative course.
- Published
- 2020
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4. Superior Vena Cava Obstruction Secondary to Prolonged Calcium Therapy: A Benign Etiology, Managed by Vein Graft Bypass Surgery
- Author
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Ahsan Iqbal Cheema, Chaudhry Aqeel, Gari Khan, Yousif Alqahtani, Thabet Y Gazal, and Ikram Chaudhry
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medicine.medical_specialty ,Superior vena cava syndrome ,business.industry ,Saphenous vein graft ,SVC SYNDROME ,Central venous line ,Surgery ,Refractory ,Superior vena cava ,cardiovascular system ,Etiology ,medicine ,cardiovascular diseases ,medicine.symptom ,business ,Vein graft bypass - Abstract
We like to report this case of a 28-year-old lady, who had celiac disease and developed complete Superior Vena Cava Obstruction secondary to prolonged corrective calcium therapy for refractory Hypocalcemia through the central venous line. Usually Superior Vena Cava Syndrome (SVCS) due to Superior Vena Cava obstruction (SVCO) has infective and malignant etiologies. Our case is a rare and benign cause, managed surgically after failed endovascular recanalization by the interventional radiologist.
- Published
- 2020
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5. Assessment Of Choroidal And Retinal Changes In Cases Of Central Serous Chorioretinopathy Treated With Oral Eplerenone
- Author
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Abdelaziz, N A, primary, Abdalla, T M, primary, Thabet, Y A, primary, and Fawzy, S M, primary
- Published
- 2020
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6. The contribution of epigenetics in Sjögren's syndrome
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Konsta, O.D. Thabet, Y. Le Dantec, C. Brooks, W.H. Tzioufas, A.G. Pers, J.-O. Renaudineau, Y.
- Abstract
Sjögren's syndrome (SS) is a chronic autoimmune epithelitis that combines exocrine gland dysfunctions and lymphocytic infiltrations. While the pathogenesis of SS remains unclear, its etiology is multifunctional and includes a combination of genetic predispositions, environmental factors, and epigenetic factors. Recently, interest has grown in the involvement of epigenetics in autoimmune diseases. Epigenetics is defined as changes in gene expression, that are inheritable and that do not entail changes in the DNA sequence. In SS, several epigenetic mechanisms are defective including DNA demethylation that predominates in epithelial cells, an abnormal expression of microRNAs, and abnormal chromatin positioning-associated with autoantibody production. Last but not least, epigenetic modifications are reversible as observed in minor salivary glands from SS patients after B cell depletion using rituximab. Thus epigenetic findings in SS open new perspectives for therapeutic approaches as well as the possible identification of new biomarkers. © 2014 Konsta, Thabet, Le Dantec, Brooks, Tzioufas, Pers and Renaudineau.
- Published
- 2014
7. FRI0268 Dna demethylation characterizes salivary gland epithelial cells from patients with primary sjögren’s syndrome
- Author
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Cornec, D., primary, Thabet, Y., additional, Le Dantec, C., additional, Ghedira, I., additional, Devauchelle-Pensec, V., additional, Renaudineau, Y., additional, and Pers, J.-O., additional
- Published
- 2013
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8. Anti-cardiolipin and anti-beta 2-glycoprotein I antibodies in celiac disease
- Author
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Mankaï, A., primary, Achour, A., additional, Thabet, Y., additional, Manoubia, W., additional, Sakly, W., additional, and Ghedira, I., additional
- Published
- 2012
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9. IgA anti-actin antibodies in celiac disease
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Achour, A., primary, Thabet, Y., additional, Sakly, W., additional, Mankai, A., additional, Sakly, N., additional, Ayadi, A., additional, Sfar, M.T., additional, Amri, F., additional, Harbi, A., additional, Essoussi, A.S., additional, Krifa, A., additional, Ajmi, S., additional, and Ghedira, I., additional
- Published
- 2010
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10. Sulodexide Significantly Improves Endothelial Dysfunction and Alleviates Chest Pain and Palpitations in Patients With Long-COVID-19: Insights From TUN-EndCOV Study.
- Author
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Charfeddine S, Ibnhadjamor H, Jdidi J, Torjmen S, Kraiem S, Bahloul A, Makni A, Kallel N, Moussa N, Boudaya M, Touil I, Ghrab A, Elghoul J, Meddeb Z, Thabet Y, Ben Salem K, Addad F, Bouslama K, Milouchi S, Hammami R, Abdessalem S, and Abid L
- Abstract
Objective: Non-respiratory long-coronavirus disease 2019 (COVID-19) symptoms are mainly related to a long-lasting endothelial dysfunction and microcirculation impairment. We hypothesized that Sulodexide, a purified glycosaminoglycan mixture with a beneficial endothelial effect in arterial and venous peripheral diseases, may be effective in a subset of patients with long COVID-19., Approach and Results: We conducted a multicenter prospective quasi-experimental study. A total of 290 patients from the TUN-EndCOV study with long-COVID-19 symptoms and endothelial dysfunction were included. The endothelial function was clinically assessed using a post-occlusive reactive hyperemia protocol with finger thermal monitoring device. Endothelial quality index (EQI) was assessed at inclusion and at 21 days later. The study population was assigned to a sulodexide group (144 patients) or a no-medical treatment group (146 patients). Clinical characteristics were similar at inclusion in the two groups. Fatigue, shortness of breath, and chest pain were the most common symptoms, respectively, 54.5, 53.8, and 28.3%. At 21 days, the sulodexide group improved significantly better than the no-medical treatment group in chest pain (83.7 vs. 43.6%, p < 10
-3 ), palpitations (85.2 vs. 52.9%, p = 0.009), and endothelial function [median delta-EQI 0.66 (0.6) vs. 0.18 (0.3); p < 10-3 ]. Endothelial function improvement was significantly correlated with chest pain and palpitations recovery (AUC, i.e., area under the curve = 0.66, CI [0.57- 0.75], p = 0.001 and AUC = 0.60, CI [0.51- 0.69], p = 0.03, respectively)., Conclusion: Sulodexide significantly improves long-lasting post-COVID-19 endothelial dysfunction and alleviates chest pain and palpitations., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Charfeddine, Ibnhadjamor, Jdidi, Torjmen, Kraiem, Bahloul, Makni, Kallel, Moussa, Boudaya, Touil, Ghrab, Elghoul, Meddeb, Thabet, Ben Salem, Addad, Bouslama, Milouchi, Hammami, Abdessalem and Abid.)- Published
- 2022
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11. Piezoionic mechanoreceptors: Force-induced current generation in hydrogels.
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Dobashi Y, Yao D, Petel Y, Nguyen TN, Sarwar MS, Thabet Y, Ng CLW, Scabeni Glitz E, Nguyen GTM, Plesse C, Vidal F, Michal CA, and Madden JDW
- Subjects
- Humans, Mechanical Phenomena, Skin, Touch physiology, Hydrogels, Mechanoreceptors
- Abstract
The human somatosensory network relies on ionic currents to sense, transmit, and process tactile information. We investigate hydrogels that similarly transduce pressure into ionic currents, forming a piezoionic skin. As in rapid- and slow-adapting mechanoreceptors, piezoionic currents can vary widely in duration, from milliseconds to hundreds of seconds. These currents are shown to elicit direct neuromodulation and muscle excitation, suggesting a path toward bionic sensory interfaces. The signal magnitude and duration depend on cationic and anionic mobility differences. Patterned hydrogel films with gradients of fixed charge provide voltage offsets akin to cell potentials. The combined effects enable the creation of self-powered and ultrasoft piezoionic mechanoreceptors that generate a charge density four to six orders of magnitude higher than those of triboelectric and piezoelectric devices.
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- 2022
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12. Methods for preparation of niosomes: A focus on thin-film hydration method.
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Thabet Y, Elsabahy M, and Eissa NG
- Subjects
- Particle Size, Surface-Active Agents chemistry, Drug Delivery Systems methods, Liposomes chemistry
- Abstract
Development of nanocarriers has opened new avenues for the delivery of therapeutics of various pharmacological activities with improved targeting properties and reduced side effects. Niosomes, non-ionic-based vesicles, have drawn much interest in various biomedical applications, owing to their unique characteristics and their ability to encapsulate both hydrophilic and lipophilic cargoes. Niosomes share structural similarity with liposomes while overcoming limitations associated with stability, sterilization, and large-scale production of liposomes. Different methods for preparation of niosomes have been described in the literature, each having its own merits and a great impact on the sizes and characteristics of the formed niosomes. In this article, procedures involved in the thin-film hydration method, a commonly used method for the preparation of niosomes, are described in detail, while highlighting precautions that should be considered for consistent and reproducible construction of niosomes., (Copyright © 2021 Elsevier Inc. All rights reserved.)
- Published
- 2022
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13. Long COVID 19 Syndrome: Is It Related to Microcirculation and Endothelial Dysfunction? Insights From TUN-EndCOV Study.
- Author
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Charfeddine S, Ibn Hadj Amor H, Jdidi J, Torjmen S, Kraiem S, Hammami R, Bahloul A, Kallel N, Moussa N, Touil I, Ghrab A, Elghoul J, Meddeb Z, Thabet Y, Kammoun S, Bouslama K, Milouchi S, Abdessalem S, and Abid L
- Abstract
The COVID-19 disease is a multisystem disease due in part to the vascular endothelium injury. Lasting effects and long-term sequelae could persist after the infection and may be due to persistent endothelial dysfunction. Our study focused on the evaluation of endothelial quality index (EQI) by finger thermal monitoring with E4 diagnosis Polymath in a large cohort of long COVID-19 patients to determine whether long-covid 19 symptoms are associated with endothelial dysfunction. This is a cross-sectional multicenter observational study with prospective recruitment of patients. A total of 798 patients were included in this study. A total of 618 patients (77.4%) had long COVID-19 symptoms. The mean EQI was 2.02 ± 0.99 IC
95% [1.95 - 2.08]. A total of 397 (49.7%) patients had impaired EQI. Fatigue, chest pain, and neuro-cognitive difficulties were significantly associated with endothelium dysfunction with an EQI <2 after adjustment for age, sex, diabetes, hypertension, dyslipidemia, coronary heart disease, and the severity of acute COVID-19 infection. In multivariate analysis, endothelial dysfunction (EQI <2), female gender, and severe clinical status at acute COVID-19 infection with a need for oxygen supplementation were independent risk factors of long COVID-19 syndrome. Long COVID-19 symptoms, specifically non-respiratory symptoms, are due to persistent endothelial dysfunction. These findings allow for better care of patients with long COVID-19 symptoms., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Charfeddine, Ibn Hadj Amor, Jdidi, Torjmen, Kraiem, Hammami, Bahloul, Kallel, Moussa, Touil, Ghrab, Elghoul, Meddeb, Thabet, Kammoun, Bouslama, Milouchi, Abdessalem and Abid.)- Published
- 2021
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14. Intratracheal Administration of Chloroquine-Loaded Niosomes Minimize Systemic Drug Exposure.
- Author
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Saafan HA, Ibrahim KM, Thabet Y, Elbeltagy SM, Eissa RA, Ghaleb AH, Ibrahim F, Elsabahy M, and Eissa NG
- Abstract
Pulmonary administration provides a useful alternative to oral and invasive routes of administration while enhancing and prolonging the accumulation of drugs into the lungs and reducing systemic drug exposure. In this study, chloroquine, as a model drug, was loaded into niosomes for potential pulmonary administration either via dry powder inhalation or intratracheally. Chloroquine-loaded niosomes have been prepared and extensively characterized. Furthermore, drug-loaded niosomes were lyophilized and their flowing properties were evaluated by measuring the angle of repose, Carr's index, and Hausner ratio. The developed niosomes demonstrated a nanosized (100-150 nm) spherical morphology and chloroquine entrapment efficiency of ca. 24.5%. The FT-IR results indicated the incorporation of chloroquine into the niosomes, whereas in vitro release studies demonstrated an extended-release profile of the drug-loaded niosomes compared to the free drug. Lyophilized niosomes exhibited poor flowability that was not sufficiently improved after the addition of lactose or when cryoprotectants were exploited throughout the lyophilization process. In vivo, intratracheal administration of chloroquine-loaded niosomes in rats resulted in a drug concentration in the blood that was 10-fold lower than the oral administration of the free drug. Biomarkers of kidney and liver functions (i.e., creatinine, urea, AST, and ALT) following pulmonary administration of the drug-loaded nanoparticles were of similar levels to those of the control untreated animals. Hence, the use of a dry powder inhaler for administration of lyophilized niosomes is not recommended, whereas intratracheal administration might provide a promising strategy for pulmonary administration of niosomal dispersions while minimizing systemic drug exposure and adverse reactions.
- Published
- 2021
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15. Retention of a telescopic overdenture on customized abutments after the simulation of 1 year in function.
- Author
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Ramadan R, Elsherbeeny Y, Thabet Y, Kandil B, and Ghali R
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- Dental Care, Dental Prosthesis, Implant-Supported, Dental Stress Analysis, Humans, Denture Retention, Denture, Overlay
- Abstract
Background: Telescopic implant-retained overdentures are considered one of the most common treatment modalities for edentulous patients., Objectives: The aim of the study was to evaluate the retention of a BioHPP (biocompatible highperformance polymer) telescopic overdenture supported by customized abutments made from 2 different materials after the simulation of 1 year in function., Material and Methods: Twelve models of a completely edentulous mandible were three-dimensionally (3D)-printed. Two implants and 2 groups of customized abutments - group Bio: BioHPP (n = 6) and group Ti: titanium (n = 6) - were used to support BioHPP telescopic overdentures. A vertically dislodging force was applied to each denture until its separation before and after 240,000 cycles of chewing simulation and 1,440 iterations of cyclic dislodgement for the simulation of 1 year in function in order to measure maximum tensile loads needed to dislodge the overdenture. Student's t test and the paired t test were used for the statistical analysis (α = 0.05)., Results: The initial and final retentive forces of the Ti group were significantly higher than in the case of the Bio group. A significant decrease in the retentive forces within the 2 groups after chewing simulation was observed and it was higher in group Ti; however, there was no statistically significant difference between the 2 groups., Conclusions: The retentive force values for implant-retained telescopic overdentures significantly decreased after the simulation of 1 year of overdenture use. Both BioHPP and titanium are considered suitable abutment materials to retain telescopic overdentures.
- Published
- 2021
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16. Publisher Correction: Tumor-necrosis factor impairs CD4 + T cell-mediated immunological control in chronic viral infection.
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Beyer M, Abdullah Z, Chemnitz JM, Maisel D, Sander J, Lehmann C, Thabet Y, Shinde PV, Schmidleithner L, Köhne M, Trebicka J, Schierwagen R, Hofmann A, Popov A, Lang KS, Oxenius A, Buch T, Kurts C, Heikenwalder M, Fätkenheuer G, Lang PA, Hartmann P, Knolle PA, and Schultze JL
- Abstract
An amendment to this paper has been published and can be accessed via a link at the top of the paper.
- Published
- 2020
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17. iRhom2 inhibits bile duct obstruction-induced liver fibrosis.
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Sundaram B, Behnke K, Belancic A, Al-Salihi MA, Thabet Y, Polz R, Pellegrino R, Zhuang Y, Shinde PV, Xu HC, Vasilevska J, Longerich T, Herebian D, Mayatepek E, Bock HH, May P, Kordes C, Aghaeepour N, Mak TW, Keitel V, Häussinger D, Scheller J, Pandyra AA, Lang KS, and Lang PA
- Subjects
- ADAM17 Protein genetics, ADAM17 Protein metabolism, Animals, Anti-Inflammatory Agents, Non-Steroidal pharmacology, Bile Ducts surgery, Carrier Proteins metabolism, Cells, Cultured, Cholestasis metabolism, Etanercept pharmacology, Gene Expression Regulation, Hepatic Stellate Cells drug effects, Hepatic Stellate Cells metabolism, Humans, Ligation, Liver Cirrhosis metabolism, Liver Cirrhosis prevention & control, Male, Mice, Inbred C57BL, Mice, Knockout, Receptors, Tumor Necrosis Factor, Type I genetics, Receptors, Tumor Necrosis Factor, Type I metabolism, Receptors, Tumor Necrosis Factor, Type II genetics, Receptors, Tumor Necrosis Factor, Type II metabolism, Signal Transduction drug effects, Carrier Proteins genetics, Cholestasis genetics, Liver Cirrhosis genetics, Signal Transduction genetics
- Abstract
Chronic liver disease can induce prolonged activation of hepatic stellate cells, which may result in liver fibrosis. Inactive rhomboid protein 2 (iRhom2) is required for the maturation of A disintegrin and metalloprotease 17 (ADAM17, also called TACE), which is responsible for the cleavage of membrane-bound tumor necrosis factor-α (TNF-α) and its receptors (TNFRs). Here, using the murine bile duct ligation (BDL) model, we showed that the abundance of iRhom2 and activation of ADAM17 increased during liver fibrosis. Consistent with this, concentrations of ADAM17 substrates were increased in plasma samples from mice after BDL and in patients suffering from liver cirrhosis. We observed increased liver fibrosis, accelerated disease progression, and an increase in activated stellate cells after BDL in mice lacking iRhom2 ( Rhbdf2
-/- ) compared to that in controls. In vitro primary mouse hepatic stellate cells exhibited iRhom2-dependent shedding of the ADAM17 substrates TNFR1 and TNFR2. In vivo TNFR shedding after BDL also depended on iRhom2. Treatment of Rhbdf2-/- mice with the TNF-α inhibitor etanercept reduced the presence of activated stellate cells and alleviated liver fibrosis after BDL. Together, these data suggest that iRhom2-mediated inhibition of TNFR signaling protects against liver fibrosis., (Copyright © 2019 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.)- Published
- 2019
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18. Enzymatic Activity of HPGD in Treg Cells Suppresses Tconv Cells to Maintain Adipose Tissue Homeostasis and Prevent Metabolic Dysfunction.
- Author
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Schmidleithner L, Thabet Y, Schönfeld E, Köhne M, Sommer D, Abdullah Z, Sadlon T, Osei-Sarpong C, Subbaramaiah K, Copperi F, Haendler K, Varga T, Schanz O, Bourry S, Bassler K, Krebs W, Peters AE, Baumgart AK, Schneeweiss M, Klee K, Schmidt SV, Nüssing S, Sander J, Ohkura N, Waha A, Sparwasser T, Wunderlich FT, Förster I, Ulas T, Weighardt H, Sakaguchi S, Pfeifer A, Blüher M, Dannenberg AJ, Ferreirós N, Muglia LJ, Wickenhauser C, Barry SC, Schultze JL, and Beyer M
- Subjects
- 3T3 Cells, Animals, Cell Line, Diabetes Mellitus, Type 2 metabolism, HEK293 Cells, Homeostasis immunology, Humans, Hydroxyprostaglandin Dehydrogenases genetics, Insulin Resistance genetics, Intra-Abdominal Fat cytology, Jurkat Cells, Lymphocyte Activation immunology, Male, Mice, Mice, Knockout, STAT5 Transcription Factor metabolism, Dinoprostone analogs & derivatives, Dinoprostone metabolism, Hydroxyprostaglandin Dehydrogenases metabolism, Intra-Abdominal Fat immunology, T-Lymphocytes, Regulatory enzymology, T-Lymphocytes, Regulatory immunology
- Abstract
Regulatory T cells (Treg cells) are important for preventing autoimmunity and maintaining tissue homeostasis, but whether Treg cells can adopt tissue- or immune-context-specific suppressive mechanisms is unclear. Here, we found that the enzyme hydroxyprostaglandin dehydrogenase (HPGD), which catabolizes prostaglandin E
2 (PGE2 ) into the metabolite 15-keto PGE2 , was highly expressed in Treg cells, particularly those in visceral adipose tissue (VAT). Nuclear receptor peroxisome proliferator-activated receptor-γ (PPARγ)-induced HPGD expression in VAT Treg cells, and consequential Treg-cell-mediated generation of 15-keto PGE2 suppressed conventional T cell activation and proliferation. Conditional deletion of Hpgd in mouse Treg cells resulted in the accumulation of functionally impaired Treg cells specifically in VAT, causing local inflammation and systemic insulin resistance. Consistent with this mechanism, humans with type 2 diabetes showed decreased HPGD expression in Treg cells. These data indicate that HPGD-mediated suppression is a tissue- and context-dependent suppressive mechanism used by Treg cells to maintain adipose tissue homeostasis., (Copyright © 2019 Elsevier Inc. All rights reserved.)- Published
- 2019
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19. Comparative study on disintegration methods for oral film preparations.
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Speer I, Steiner D, Thabet Y, Breitkreutz J, and Kwade A
- Subjects
- Administration, Oral, Chemistry, Pharmaceutical methods, Drug Compounding methods, Hypromellose Derivatives chemistry, Quality Control, Solubility, Cellulose chemistry, Drug Delivery Systems, Polymers chemistry, Solvents chemistry
- Abstract
Orodispersible films (ODFs) provide high application comfort due to rapid disintegration in the oral cavity. They increasingly found the approval of pharmaceutical research and development and were added to the European Pharmacopeia in 2012. The European Pharmacopeia explicitly demands disintegration testing for ODFs, but does not refer to a suitable method. The aim of this study was to collect and evaluate existing disintegration methods regarding their suitability to investigate different ODF formulations. Therefore, 21 ODF formulations produced at different gap heights and/or different amounts of suspended microcrystalline cellulose (MCC) particles were manufactured by solvent casting technique, using hypromellose (HPMC) as film-forming polymer. Four disintegration methods described in literature were applied to characterize the disintegration behavior of these formulations. They were the petri dish, the slide frame, slide frame and ball (SFaB) method as well as the PharmaTest
® disintegration tester equipped with a film sample holder. All methods show similar tendencies, at which the disintegration time proportionally increases with increasing dry film thicknesses. Reduced disintegration times were observed for ODFs containing insoluble MCC particles compared to their corresponding particle-free formulations. However, the suitability to investigate varying types of ODFs applying the four different test methods highly depends on the intended purpose. Therefore, the slide frame and SFaB method seems to be particularly applicable for research and development purposes, whereas the PharmaTest® disintegration tester and the SFaB method fulfil the demands required for testing methods within the quality control., (Copyright © 2018 Elsevier B.V. All rights reserved.)- Published
- 2018
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20. Drug Formulations: Standards and Novel Strategies for Drug Administration in Pediatrics.
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Thabet Y, Klingmann V, and Breitkreutz J
- Subjects
- Animals, Child, Dosage Forms, Drug Administration Routes, Excipients administration & dosage, Humans, Pharmaceutical Preparations administration & dosage, Taste, Chemistry, Pharmaceutical, Pediatrics
- Abstract
Child-appropriate drug formulations are a prerequisite of successful drug therapy in children. Efficacy and safety must be given for the active pharmaceutical ingredient, but safety also for the used excipients, components of primary packaging materials, and devices. We are presently experiencing exciting times for pediatric drug development, stimulated by previous governmental incentives in both the European Union and the United States. The most important advances in pediatric drug formulation development are reviewed and evaluated in this article. Scientific publications and recent industry strategies indicate a clear shift from liquid dosage forms to novel solid dosage forms. Solid formulations are usually composed from excipients generally regarded as safe, whereas many liquid formulations contain excipients such as preservatives, antioxidants, or taste-masking agents that raise concerns. Further, some recent clinical studies on swallowability, acceptability, and preference indicate superiority for small-sized tablets, so-called mini-tablets, over conventional liquids. In general, multiparticulate solid dosage forms could partly replace the liquids and provide more stable and cheaper alternatives to existing drug products or new developments. Dispersible solid drug dosage forms like orodispersible tablets, mini-tablets and films are even better opportunities for efficient and safe use in pediatrics. Novel measuring and administration devices may facilitate the handling and drug administration of these modern drug dosage forms. Combination products (drug-device combinations) can easily be linked with new e-health technologies in near future to further improve pediatric drug therapy., (© 2018, The American College of Clinical Pharmacology.)
- Published
- 2018
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21. Continuous inkjet printing of enalapril maleate onto orodispersible film formulations.
- Author
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Thabet Y, Lunter D, and Breitkreutz J
- Subjects
- Administration, Oral, Drug Combinations, Ethanol chemistry, Ink, Methanol chemistry, Polyethylene Glycols chemistry, Solvents chemistry, Water chemistry, Antihypertensive Agents chemistry, Dosage Forms, Drug Compounding methods, Enalapril chemistry, Hydrochlorothiazide chemistry, Printing
- Abstract
Piezoelectric inkjet printing onto orodispersible films (ODFs) was proven to be a successful technique applying flexible doses of active pharmaceutical ingredients (APIs) onto edible substrates. The reported API printing and ODF production was conducted in a non-continuous production approach. Within this study, drug-free and hydrochlorothiazide (HCT) containing ODFs should be imprinted in-line with enalapril maleate (EM) ink during continuous ODF production. Macrogol inks based on various solvents and solvent-water mixtures were developed providing dynamic viscosities from 7 to 17 mPa*s. Water based inks contained 1.25%, methanol based inks up to 10% EM. Both inks could be printed (500-1000 Hz) during continuous ODF production. No EM recrystallization was observed for water-based inks. Mechanical properties were not affected by drug printing using various firing frequencies. ODF imprinted with water-based EM inks contained 0.04 mg EM/6 cm
2 . EM amount can be increased to a paediatric therapeutic dose of 0.5 mg EM utilizing methanol-based inks. These inks were successfully printed onto HCT ODFs resulting in a therapeutically relevant fixed-dose combination. No EM migration into the HCT layer could be observed. In conclusion, it was feasible to print EM doses onto drug-free and HCT ODFs during an in-line continuous manufacturing process., (Copyright © 2018 Elsevier B.V. All rights reserved.)- Published
- 2018
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22. Continuous manufacturing and analytical characterization of fixed-dose, multilayer orodispersible films.
- Author
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Thabet Y, Lunter D, and Breitkreutz J
- Subjects
- Administration, Oral, Angiotensin-Converting Enzyme Inhibitors administration & dosage, Antihypertensive Agents administration & dosage, Cellulose analogs & derivatives, Cellulose chemistry, Drug Combinations, Drug Compounding, Drug Liberation, Enalapril administration & dosage, Hydrochlorothiazide administration & dosage, Polyvinyl Alcohol chemistry, Sodium Chloride Symporter Inhibitors administration & dosage, Solubility, Solvents chemistry, Spectrum Analysis, Raman, Angiotensin-Converting Enzyme Inhibitors chemistry, Antihypertensive Agents chemistry, Enalapril chemistry, Hydrochlorothiazide chemistry, Sodium Chloride Symporter Inhibitors chemistry, Technology, Pharmaceutical methods
- Abstract
Various drug therapies require more than one active pharmaceutical ingredient (API) for an effective treatment. There are many advantages, e.g. to improve the compliance or pharmacodynamic response in comparison to a monotherapy or to increase the therapy safety. Until now, there are only a few products available for the paediatric population due to the lack of age appropriate dosage forms or studies proving the efficacy and safety of these products. This study aims to develop orodispersible films (ODFs) in a continuous solvent casting process as child appropriate dosage form containing both enalapril maleate (EM) and hydrochlorothiazide (HCT) separated in different film layers. Furthermore, they should be characterised and the API migration analysed by confocal Raman microscopy (CRM). ODFs were successfully produced in a continuous manufacturing process in form of double- and triple-layer formulations based on hydroxypropylcellulose (HPC) or a combination of HPC and polyvinyl alcohol (PVA). CRM revealed that both APIs migrate within the film layers shortly after manufacturing. PVA inhibits the migration inside the double-layer film, but is not able to prevent the API migration as an interlayer inside a triple-layer ODF. With increasing film layers, the content of residual solvents and the disintegration time increases (mono-layer films: <10 s, triple-layer films: 37 s). In conclusion, it was feasible to produce fixed-dose combinations in therapeutic doses up to 9 mg HCT and 3.5 mg EM for the double-layer film with adequate mechanical properties, which enable coiling up onto jumbo rolls directly after production. The best separation of the two APIs was achieved by casting a double-layer ODF consisting of different film forming polymers, which can be beneficial when processing two incompatible APIs., (Copyright © 2018 Elsevier B.V. All rights reserved.)
- Published
- 2018
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23. Flexible and precise dosing of enalapril maleate for all paediatric age groups utilizing orodispersible minitablets.
- Author
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Thabet Y, Walsh J, and Breitkreutz J
- Subjects
- Administration, Oral, Child, Drug Stability, Enteral Nutrition, Feasibility Studies, Heart Failure drug therapy, Humans, Syringes, Tablets, Angiotensin-Converting Enzyme Inhibitors administration & dosage, Beverages, Drug Compounding methods, Enalapril administration & dosage, Food-Drug Interactions
- Abstract
Enalapril is an off-patent angiotensin-converting enzyme inhibitor for which no paediatric age-appropriate formulation is commercially available in Europe, and enalapril maleate (EM) orodispersible minitablets (ODMTs) have previously been formulated within the LENA (labelling enalapril from neonates to adolescents) project. In this study, a dilution method has been developed by dispersing the lowest dose strength ODMTs to enable flexible and precise EM dosing during the dose titration phase of the therapy. Furthermore, the physicochemical stability of the ODMTs has been investigated in child-friendly beverages and the administration of ODMTs via nasogastric tubes (NGT) of different sizes and materials has been evaluated. The results for the ODMT dilution procedure reveal that dispersion within an oral syringe is preferred over dispersion in a separate container, leading to flexible and precise dosing down to 0.025 mg EM. Although ODMTs were stable in the beverages over the investigated time period, dispersion in tap water only is recommended due to prolonged disintegration times within the other beverages. Dispersed ODMTs can be administered through NGTs of CH5. Almost no adsoprtion of EM on silicone, polyurethane or polyvinyl chloride could be observed. The ODMT concept together with the investigated dispersion method enables the safe administration of EM for all paediatric subpopulations from new-borns to adolescents., (Copyright © 2018 Elsevier B.V. All rights reserved.)
- Published
- 2018
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24. 10 years EU regulation of pediatric medicines - impact on cardiovascular drug formulations.
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Thabet Y, Slavkova M, and Breitkreutz J
- Subjects
- Administration, Oral, Cardiovascular Diseases drug therapy, Chemistry, Pharmaceutical trends, Child, Drug Development, Humans, Cardiovascular Agents chemistry, Chemistry, Pharmaceutical legislation & jurisprudence, Drug and Narcotic Control legislation & jurisprudence, European Union
- Abstract
Introduction: Child-appropriate drug formulations are mandatory for an efficient and safe drug therapy in children. Since the implementation of supportive legislations development of novel drug formulations has significantly been enforced despite the fact that children are a heterogeneous group of patients with varying needs according to age, maturation and disease., Areas Covered: In this review, recent advances and current strategies are evaluated how to overcome the specific hurdles in pediatric drug development. For cardiovascular diseases as an example, EMA's decisions on pediatric investigation plans (PIPs) have been evaluated. New developments with innovative platform technologies such as mini-tablets and orodispersible preparations have been identified indicating a clear shift from liquid preparations to small-sized solid (multiparticulate) or orodispersible dosage forms. Reasons for this shift of paradigm are discussed., Expert Opinion: Innovative platform technologies for solid drug dosage forms such as mini-tablets, orodispersible tablets or film preparations will continue to conquer the pharmaceutical market. Still, there are some major issues to be resolved, e.g. how to ensure quality of the new dosage forms and dose accuracy in flexible dosing, but the governmental incentives will continue to accelerate development of pediatric medicines and will bridge the still existing gaps in the near future.
- Published
- 2018
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25. Orodispersible films: Product transfer from lab-scale to continuous manufacturing.
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Thabet Y and Breitkreutz J
- Subjects
- Administration, Oral, Cellulose analogs & derivatives, Cellulose chemistry, Desiccation, Drug Compounding, Hydrochlorothiazide chemistry, Hypromellose Derivatives chemistry, Viscosity, Drug Delivery Systems
- Abstract
Orodispersible films have been described as new beneficial dosage forms for special patient populations. Due to various production settings, different requirements on film formulations are required for non- continuous and continuous manufacturing. In this study, a continuous coating machine was qualified in regards of the process conditions for film compositions and their effects on the formed films. To investigate differences between both manufacturing processes, various film formulations of hydrochlorothiazide and hydroxypropylcellulose (HPC) or hydroxypropylmethycellulose (HPMC) as film formers were produced and the resulting films were characterized. The qualification of the continuously operating coating machine reveals no uniform heat distribution during drying. Coating solutions for continuous manufacturing should provide at least a dynamic viscosity of 1 Pa*s (wet film thickness of 500 μm, velocity of 15.9 cm/min). HPC films contain higher residuals of ethanol or acetone in bench-scale than in continuous production mode. Continuous production lead to lower drug content of the films. All continuously produced films disintegrate within less than 30 s. There are observed significant effects of the production process on the film characteristics. When transferring film manufacturing from lab-scale to continuous mode, film compositions, processing conditions and suitable characterization methods have to be carefully selected and adopted., (Copyright © 2017 Elsevier B.V. All rights reserved.)
- Published
- 2018
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26. Tumor-necrosis factor impairs CD4(+) T cell-mediated immunological control in chronic viral infection.
- Author
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Beyer M, Abdullah Z, Chemnitz JM, Maisel D, Sander J, Lehmann C, Thabet Y, Shinde PV, Schmidleithner L, Köhne M, Trebicka J, Schierwagen R, Hofmann A, Popov A, Lang KS, Oxenius A, Buch T, Kurts C, Heikenwalder M, Fätkenheuer G, Lang PA, Hartmann P, Knolle PA, and Schultze JL
- Subjects
- Adolescent, Adult, Aged, Animals, CD4-Positive T-Lymphocytes metabolism, CD4-Positive T-Lymphocytes virology, Flow Cytometry, HEK293 Cells, HIV physiology, HIV Infections genetics, HIV Infections virology, Host-Pathogen Interactions immunology, Humans, Immunoblotting, Lymphocytic Choriomeningitis genetics, Lymphocytic Choriomeningitis virology, Lymphocytic choriomeningitis virus physiology, Mice, Inbred C57BL, Mice, Knockout, Mice, Transgenic, Middle Aged, Oligonucleotide Array Sequence Analysis, Programmed Cell Death 1 Receptor genetics, Programmed Cell Death 1 Receptor immunology, Programmed Cell Death 1 Receptor metabolism, Receptors, Tumor Necrosis Factor genetics, Receptors, Tumor Necrosis Factor immunology, Receptors, Tumor Necrosis Factor metabolism, Reverse Transcriptase Polymerase Chain Reaction, Transcriptome drug effects, Transcriptome genetics, Transcriptome immunology, Tumor Necrosis Factor-alpha metabolism, Tumor Necrosis Factor-alpha pharmacology, Young Adult, CD4-Positive T-Lymphocytes immunology, HIV immunology, HIV Infections immunology, Lymphocytic Choriomeningitis immunology, Lymphocytic choriomeningitis virus immunology, Tumor Necrosis Factor-alpha immunology
- Abstract
Persistent viral infections are characterized by the simultaneous presence of chronic inflammation and T cell dysfunction. In prototypic models of chronicity--infection with human immunodeficiency virus (HIV) or lymphocytic choriomeningitis virus (LCMV)--we used transcriptome-based modeling to reveal that CD4(+) T cells were co-exposed not only to multiple inhibitory signals but also to tumor-necrosis factor (TNF). Blockade of TNF during chronic infection with LCMV abrogated the inhibitory gene-expression signature in CD4(+) T cells, including reduced expression of the inhibitory receptor PD-1, and reconstituted virus-specific immunity, which led to control of infection. Preventing signaling via the TNF receptor selectively in T cells sufficed to induce these effects. Targeted immunological interventions to disrupt the TNF-mediated link between chronic inflammation and T cell dysfunction might therefore lead to therapies to overcome persistent viral infection.
- Published
- 2016
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27. Corrigendum: Efficient genome engineering by targeted homologous recombination in mouse embryos using transcription activator-like effector nucleases.
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Sommer D, Peters AE, Wirtz T, Mai M, Ackermann J, Thabet Y, Schmidt J, Weighardt H, Wunderlich FT, Degen J, Schultze JL, and Beyer M
- Published
- 2015
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28. DNA methylation modulates HRES1/p28 expression in B cells from patients with Lupus.
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Fali T, Le Dantec C, Thabet Y, Jousse S, Hanrotel C, Youinou P, Brooks WH, Perl A, and Renaudineau Y
- Subjects
- Adult, Antigens, Nuclear metabolism, Autoantigens metabolism, B-Lymphocytes metabolism, DNA Methylation, Gene Expression Regulation, Humans, Interleukin-6 immunology, Interleukin-6 metabolism, Lupus Erythematosus, Systemic blood, Lupus Erythematosus, Systemic immunology, Middle Aged, Receptors, Interleukin-6 immunology, Receptors, Interleukin-6 metabolism, Retroviridae Proteins metabolism, Antigens, Nuclear immunology, Autoantigens immunology, B-Lymphocytes immunology, Lupus Erythematosus, Systemic genetics, Retroviridae Proteins immunology
- Abstract
Systemic lupus erythematosus (SLE) disease is an autoimmune disease of unknown aetiology that affects predominantly women of child bearing age. Since previous studies, including ours, have demonstrated that CD4+ T cells and B cells from SLE patients are defective in their ability to methylate their DNA upon antigen stimulation, the aim of this study was to investigate whether DNA demethylation affects the transcription of HRES-1 in B cells. HRES-1 is the prototype of Human Endogenous Retrovirus (HERV) overexpressed in SLE. We have observed that SLE B cells were characterized by their incapacity to methylate the HRES-1 promoter, both in unstimulated and in anti-IgM stimulated B cells. In turn, HRES-1/p28 expression was increased in SLE B cells after B cell receptor engagement, but not in controls. In SLE B cells the Erk/DNMT1 pathway was defective. In addition, blocking the autocrine-loop of IL-6 in SLE B cells with an anti-IL-6 receptor monoclonal antibody restores DNA methylation and control of HRES-1/p28 expression became effective. As a consequence, a better understanding of HERV dysregulation in SLE reinforces our comprehension of the disease and opens new therapeutic perspectives.
- Published
- 2014
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29. The IDO1-induced kynurenines play a major role in the antimicrobial effect of human myeloid cells against Listeria monocytogenes.
- Author
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Niño-Castro A, Abdullah Z, Popov A, Thabet Y, Beyer M, Knolle P, Domann E, Chakraborty T, Schmidt SV, and Schultze JL
- Subjects
- Animals, Cells, Cultured, Host-Pathogen Interactions, Humans, Immunity, Innate genetics, Indoleamine-Pyrrole 2,3,-Dioxygenase genetics, Mice, RNA, Small Interfering genetics, Species Specificity, Tryptophan metabolism, Up-Regulation, Indoleamine-Pyrrole 2,3,-Dioxygenase metabolism, Kynurenine immunology, Listeria monocytogenes immunology, Listeriosis immunology, Myeloid Cells physiology
- Abstract
Induction of indoleamine 2,3-dioxygenase (IDO1) is an established cellular response to infection with numerous pathogens. Several mechanisms, such as IDO1-mediated tryptophan (Trp) depletion, but also accumulation of Trp catabolites, have been associated with the antimicrobial effects of IDO(+) cells. Recent findings of IDO1 as an immunoinhibitory and signaling molecule extended these previous observations. Using infection of professional phagocytes with Listeria monocytogenes (L.m.) as a model, we illustrate that IDO1 induction is a species-specific event observed in human, but not murine myeloid, cells. Knockdown and inhibition experiments indicate that IDO1 enzymatic activity is required for the anti-L.m. effect. Surprisingly, the IDO1-mediated antimicrobial effect is less prominent when Trp is depleted, but can be significantly amplified by tryptophan excess, leading to increased accumulation of catabolites that promote enhanced bactericidal activity. We observed a pathogen-specific pattern with kynurenine and 3-hydroxy-kynurenine being most potent against L.m., but not against other bacteria. Hence, apparent discrepant findings concerning IDO1-mediated antimicrobial mechanisms can be reconciled by a model of species and pathogen-specificity of IDO1 function. Our findings highlight the necessity to consider species- and pathogen-specific aspects of host-pathogen interactions when elucidating the individual role of antimicrobial proteins such as IDO1.
- Published
- 2014
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30. The contribution of epigenetics in Sjögren's Syndrome.
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Konsta OD, Thabet Y, Le Dantec C, Brooks WH, Tzioufas AG, Pers JO, and Renaudineau Y
- Abstract
Sjögren's syndrome (SS) is a chronic autoimmune epithelitis that combines exocrine gland dysfunctions and lymphocytic infiltrations. While the pathogenesis of SS remains unclear, its etiology is multifunctional and includes a combination of genetic predispositions, environmental factors, and epigenetic factors. Recently, interest has grown in the involvement of epigenetics in autoimmune diseases. Epigenetics is defined as changes in gene expression, that are inheritable and that do not entail changes in the DNA sequence. In SS, several epigenetic mechanisms are defective including DNA demethylation that predominates in epithelial cells, an abnormal expression of microRNAs, and abnormal chromatin positioning-associated with autoantibody production. Last but not least, epigenetic modifications are reversible as observed in minor salivary glands from SS patients after B cell depletion using rituximab. Thus epigenetic findings in SS open new perspectives for therapeutic approaches as well as the possible identification of new biomarkers.
- Published
- 2014
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31. Efficient genome engineering by targeted homologous recombination in mouse embryos using transcription activator-like effector nucleases.
- Author
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Sommer D, Peters A, Wirtz T, Mai M, Ackermann J, Thabet Y, Schmidt J, Weighardt H, Wunderlich FT, Degen J, Schultze JL, and Beyer M
- Subjects
- Amino Acid Sequence, Animals, Base Sequence, Cells, Cultured, DNA genetics, Embryo, Mammalian physiology, Embryonic Stem Cells cytology, Embryonic Stem Cells physiology, Genetic Vectors genetics, Genetic Vectors physiology, Integrases physiology, Matrix Attachment Region Binding Proteins genetics, Matrix Attachment Region Binding Proteins physiology, Mice, Models, Animal, Molecular Sequence Data, NIH 3T3 Cells, Oocytes cytology, Oocytes physiology, Deoxyribonucleases genetics, Deoxyribonucleases physiology, Embryo, Mammalian cytology, Gene Targeting methods, Genetic Engineering methods, Recombination, Genetic genetics, Transcriptional Activation genetics, Transcriptional Activation physiology
- Abstract
Generation of mouse models by introducing transgenes using homologous recombination is critical for understanding fundamental biology and pathology of human diseases. Here we investigate whether artificial transcription activator-like effector nucleases (TALENs)-powerful tools that induce DNA double-strand breaks at specific genomic locations-can be combined with a targeting vector to induce homologous recombination for the introduction of a transgene in embryonic stem cells and fertilized murine oocytes. We describe the generation of a conditional mouse model using TALENs, which introduce double-strand breaks at the genomic locus of the special AT-rich sequence-binding protein-1 in combination with a large 14.4 kb targeting template vector. We report successful germline transmission of this allele and demonstrate its recombination in primary cells in the presence of Cre-recombinase. These results suggest that TALEN-assisted induction of DNA double-strand breaks can facilitate homologous recombination of complex targeting constructs directly in oocytes.
- Published
- 2014
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32. Anti-Saccharomyces cerevisiae antibodies in patients with systemic lupus erythematosus.
- Author
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Mankaï A, Sakly W, Thabet Y, Achour A, Manoubi W, and Ghedira I
- Subjects
- Adolescent, Adult, Aged, Female, Humans, Immunoglobulin A blood, Immunoglobulin G blood, Lupus Erythematosus, Systemic etiology, Male, Middle Aged, beta 2-Glycoprotein I immunology, Antibodies, Fungal blood, Lupus Erythematosus, Systemic microbiology, Saccharomyces cerevisiae immunology
- Abstract
Anti-Saccharomyces cerevisiae antibodies (ASCA) had been known to be specific for Crohn's disease but it has been found in many other autoimmune diseases like systemic lupus erythematosus (SLE). Furthermore, cross-reactive epitopes on β2-glycoprotein I (β2GPI) and Saccharomyces cerevisiae were found in SLE patients. The aims of this study were to evaluate the frequency of ASCA in patients with SLE and to compare it with that of anti-β2GPI antibodies (aβ2GPI). Sera of 116 patients with SLE were analyzed in this retrospective study. All patients fulfilled at least 4 criteria of the 1997 American College of Rheumatology updated criteria for the classification of SLE. Sera of 160 blood donors were included as normal controls. ASCA IgA and IgG and aβ2GPI antibodies were determined by enzyme-linked immunosorbent assays. The frequency of ASCA (IgG and/or IgA) was significantly higher in SLE patients than in control group (31.9 vs. 3.7 %, p < 10(-6)). ASCA IgG and ASCA IgA were more frequent in SLE patients than in control group (29.3 vs. 3.1 %, p < 10(-6) and 12.1 vs. 0.6 %, p = 10(-4), respectively). The mean level of ASCA IgG was higher than that of ASCA IgA (9.5 vs. 6.4 U/ml) but the difference was not statistically significant. The frequencies of aβ2GPI (IgG and/or IgA) and aβ2GPI IgA were significantly higher than those of ASCA (IgG and/or IgA) and ASCA IgA (54.3 vs. 31.9 %, p = 5 × 10(-4) and 50.9 vs. 12.1 %, p < 10(-6), respectively). Increased ASCA IgG was observed in patients with SLE, suggesting a role of environmental stimuli in its pathogenesis.
- Published
- 2013
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33. Epigenetic dysregulation in salivary glands from patients with primary Sjögren's syndrome may be ascribed to infiltrating B cells.
- Author
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Thabet Y, Le Dantec C, Ghedira I, Devauchelle V, Cornec D, Pers JO, and Renaudineau Y
- Subjects
- Antibodies, Monoclonal immunology, Antibodies, Monoclonal pharmacology, Antigens, CD20 immunology, B-Lymphocytes drug effects, B-Lymphocytes metabolism, Cell Cycle Proteins genetics, Cell Cycle Proteins immunology, Cell Line, Cells, Cultured, Coculture Techniques, DNA (Cytosine-5-)-Methyltransferase 1, DNA (Cytosine-5-)-Methyltransferases genetics, DNA (Cytosine-5-)-Methyltransferases immunology, DNA Methylation immunology, Epithelial Cells immunology, Epithelial Cells metabolism, Extracellular Signal-Regulated MAP Kinases immunology, Extracellular Signal-Regulated MAP Kinases metabolism, Gene Expression immunology, Humans, Intercellular Adhesion Molecule-1 immunology, Intercellular Adhesion Molecule-1 metabolism, Microscopy, Fluorescence, Nuclear Proteins genetics, Nuclear Proteins immunology, Protein Kinase C-delta immunology, Protein Kinase C-delta metabolism, Reverse Transcriptase Polymerase Chain Reaction, Salivary Glands metabolism, Salivary Glands pathology, Signal Transduction immunology, Sjogren's Syndrome genetics, Sjogren's Syndrome pathology, B-Lymphocytes immunology, Epigenesis, Genetic immunology, Salivary Glands immunology, Sjogren's Syndrome immunology
- Abstract
Sjögren's syndrome (SS) is an autoimmune exocrinopathy characterized by an epithelium injury with dense lymphocytic infiltrates, mainly composed of activated T and B cells. Present at the interface of genetic and environmental risk factors, DNA methylation is suspected to play a key role in SS. To clarify this point, global DNA methylation was tested within salivary gland epithelial cells (SGEC), peripheral T cells and B cells from SS patients. Global DNA methylation was reduced in SGEC from SS patients, while no difference was observed in T and B cells. SGEC demethylation in SS patients was associated with a 7-fold decrease in DNA methyl transferase (DNMT) 1 and a 2-fold increase in Gadd45-alpha expression. The other DNA methylation/demethylation partners, tested by real time PCR (DNMT3a/b, PCNA, UHRF1, MBD2, and MBD4), were not different. Interestingly, SGEC demethylation may be attributed in part to the infiltrating B cells as suspected in patients treated with anti-CD20 antibodies to deplete B cells. Such hypothesis was confirmed using co-culture experiments with human salivary gland cells and B cells. Furthermore, B cell-mediated DNA demethylation could be ascribed to an alteration of the PKC delta/ERK/DNMT1 pathway. As a consequence, part of the SGEC dysfunction in SS may be linked to epigenetic modifications, thus opening new therapeutic perspectives in SS., (Copyright © 2013 Elsevier Ltd. All rights reserved.)
- Published
- 2013
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34. Anti-Saccharomyces cerevisiae antibodies are elevated in Graves' disease but not in Hashimoto's thyroiditis.
- Author
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Mankaï A, Thabet Y, Manoubi W, Achour A, Sakly W, and Ghedira I
- Subjects
- Adolescent, Adult, Aged, Antibodies, Fungal blood, Child, Female, Graves Disease epidemiology, Hashimoto Disease epidemiology, Humans, Immunoglobulin A biosynthesis, Immunoglobulin A blood, Immunoglobulin G biosynthesis, Immunoglobulin G blood, Male, Middle Aged, Tunisia epidemiology, Young Adult, Antibodies, Fungal biosynthesis, Graves Disease immunology, Hashimoto Disease immunology, Saccharomyces cerevisiae immunology
- Abstract
Background: Anti-Saccharomyces cerevisiae antibodies (ASCA) had been known to be specific for Crohn's disease, but they had also been found in many other autoimmune diseases., Aim: The aim of this study was to evaluate the prevalence of ASCA in patients with autoimmune thyroid disease (AITD)., Patients and Methods: One hundred and ninety-seven patients with AITD and 160 healthy controls were included in the study. One hundred and nineteen patients had Graves' disease (GD) and 78 patients had Hashimoto's thyroiditis (HT). ASCA IgG and IgA were determined by ELISA., Results: ASCA IgG were significantly more frequent in patients with GD than in control group (11.8% vs. 3.1%, p = 0.002). In HT, the frequency of ASCA IgG was similar to that of the control group (3.8% and 3.1% respectively). The frequency of ASCA IgA was similar in GD (0.8%), HT (2.6%), and the control group (3.1%). In all GD patients, the frequency of ASCA IgG was significantly higher than that of ASCA IgA (11.8% vs. 0.8%, p = 0.001). These results were also true even in male and female groups (10.4% vs. 1.3%, p = 0.01 and 14.3% vs. 0%, p = 0.01, respectively). ASCA IgG levels were significantly higher in GD patients (6.7 ± 11.1 vs. 2.2 ± 2.8, p = 3 × 10(-6)) and in HT patients (4.2 ± 4.7 vs. 2.2 ± 2.8, p = 0.0002) than those in the control group. ASCA IgA levels were comparable among patients with GD, HT, and the control group. In GD patients, the mean titer of ASCA IgG was significantly higher than that of ASCA IgA (6.7 ± 11.1 vs. 3.6 ± 4.2, p = 0.005)., Conclusion: Patients with GD had a higher frequency of ASCA IgG than controls.
- Published
- 2013
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35. Performance of anti-deamidated gliadin peptides antibodies in celiac disease diagnosis.
- Author
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Sakly W, Mankaï A, Ghdess A, Achour A, Thabet Y, and Ghedira I
- Subjects
- Adolescent, Adult, Aged, Aged, 80 and over, Celiac Disease immunology, Child, Child, Preschool, Deamination, Female, Humans, Infant, Male, Middle Aged, Retrospective Studies, Young Adult, Autoantibodies blood, Celiac Disease blood, Celiac Disease diagnosis, Gliadin immunology, Peptide Fragments immunology
- Abstract
Objectives: To assess the usefulness of anti-deamidated gliadin peptides antibodies (a-DGP), in the diagnostic of celiac disease (CD)., Patients and Methods: One hundred and three untreated CD patients (67 children and 36 adults) and 36 celiac patients under gluten-free diet were studied. Two hundred and seventy-four subjects served as controls (114 healthy blood donors, 80 healthy children and 80 patients with primary biliary cirrhosis). a-DGP (IgG and IgA) and anti-tissue transglutaminase antibodies (AtTG) were detected by enzyme-linked immunosorbent assay (Elisa). Anti-endomysium antibodies (AEA) were detected by indirect immunofluorescence on human umbilical cord., Results: The sensitivitiy of IgG and IgA a-DGP were 94% and 97% respectively, compared to 96% for AEA and AtTG. The specificity of a-DGP was 93.6% for IgG and 92% for IgA. The specificity of AEA and AtTG were 100%. The frequency of IgG and IgA a-DGP was significantly higher in patients with CD than in control group (94% vs. 4.4%, P<10(-7); 97% vs. 8%, P<10(-7)). The frequency of IgG a-DGP was the same in children and adult (94%). The frequency of IgA a-DGP were similar in children and adults (95.5% vs. 100%)., Conclusion: Our study shows that a-DGP increases neither the sensitivity nor the specificity of AEA and AtTG., (Copyright © 2012 Elsevier Masson SAS. All rights reserved.)
- Published
- 2012
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36. Altered patterns of epigenetic changes in systemic lupus erythematosus and auto-antibody production: is there a link?
- Author
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Thabet Y, Cañas F, Ghedira I, Youinou P, Mageed RA, and Renaudineau Y
- Subjects
- Animals, Autoantibodies biosynthesis, B-Lymphocytes immunology, B-Lymphocytes metabolism, B-Lymphocytes pathology, Biomarkers metabolism, DNA immunology, DNA Methylation, Histones immunology, Humans, Lupus Erythematosus, Systemic pathology, Mice, Ribonucleoproteins immunology, T-Lymphocytes immunology, T-Lymphocytes metabolism, T-Lymphocytes pathology, Autoantibodies genetics, Autoantibodies immunology, Epigenesis, Genetic immunology, Lupus Erythematosus, Systemic genetics, Lupus Erythematosus, Systemic immunology, Protein Processing, Post-Translational immunology
- Abstract
The prominent feature of immunological defects in systemic lupus erythematosus (SLE) is the production of autoantibodies (auto-Abs) to nuclear antigens including DNA, histones and RNP. In addition, there is growing evidence that epigenetic changes play a key role in the pathogenesis of SLE. Autoreactive CD4(+) T cells and B cells in patients with SLE have evidence of altered patterns of DNA methylation as well as post-translational modifications of histones and ribonucleoproteins (RNP). A key question that has emerged from these two characteristic features of SLE is whether the two processes are linked. New data provide support for such a link. For example, there is evidence that hypomethylated DNA is immunogenic, that anti-histone auto-Abs in patients with SLE bind epigenetic-sensitive hot spots and that epigenetically-modified RNP-derived peptides can modulate lupus disease. All in all, the available evidence indicates that a better understanding of dysregulation in epigenetics in SLE may offer opportunities to develop new biomarkers and novel therapeutic strategies., (Copyright © 2012 Elsevier Ltd. All rights reserved.)
- Published
- 2012
- Full Text
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37. Systemic lupus erythematosus in the elderly.
- Author
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Achour A, Mankaï A, Thabet Y, Sakly W, Braham F, Kechrid C, Bahri F, Bouajina E, Chouchène S, Haddad O, and Ghedira I
- Subjects
- Age of Onset, Aged, Antibodies, Antinuclear blood, Biomarkers blood, Chi-Square Distribution, Female, Humans, Lupus Erythematosus, Systemic complications, Lupus Erythematosus, Systemic diagnosis, Male, Predictive Value of Tests, Prognosis, Retrospective Studies, Severity of Illness Index, Time Factors, Tunisia epidemiology, Lupus Erythematosus, Systemic epidemiology
- Abstract
Onset of the disease above the age of 65 years is unusual. This study was undertaken to determine retrospectively the clinical and laboratory features in SLE patients aged over 65 years. It is a retrospective study about 18 elderly patients with SLE out of 342 diagnosed between 1994 and 2009 in the center of Tunisia. All patients had at least 4 of 11 revised ACR criteria of SLE. The frequency of SLE in the elderly was 5.3%. The median age was 70 years (range 66 and 78 years). The sex ratio F/M was 5. The most frequent clinical signs were anemia (83.3%), arthralgia (55.5%), arthritis (38.9%), and malar rash (33.3%). The proteinuria and the neuropsychiatric troubles were present in 27.8% of cases. The pericarditis was present in 16.7% of cases. Antibodies to double stranded DNA (anti-dsDNA) were detected in 66.7%, anti-nucleosome in 50%, anti-SSA and anti-RNP in 27.8%, anti-Sm in 22%, and anti-SSB in 11%. Elderly patients with SLE exhibit distinct clinical and biological manifestations from the classic form. Thus, greater attention should be given for this particular subgroup of SLE patients to avoid delays in diagnosis or misdiagnosis.
- Published
- 2012
- Full Text
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38. Thyroid-related autoantibodies in Tunisian patients with type 1 diabetes.
- Author
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Sakly W, Mankaï A, Achour A, Thabet Y, Ouertani M, Boughammoura L, Harbi A, Chaieb L, Sfar MT, and Ghedira I
- Subjects
- Adolescent, Adult, Aged, Autoantibodies immunology, Child, Child, Preschool, Diabetes Mellitus, Type 1 blood, Female, Humans, Infant, Iodide Peroxidase immunology, Male, Middle Aged, Receptors, Thyrotropin immunology, Retrospective Studies, Thyroglobulin immunology, Tunisia, Autoantibodies blood, Diabetes Mellitus, Type 1 immunology, Thyroid Gland immunology
- Abstract
Aim: To evaluate, retrospectively, the frequency of antithyroid antibodies (ATA) in patients with type 1 diabetes (T1D)., Materials and Methods: Antithyroperoxidase antibodies (TPO-Ab), antithyroglobulin antibodies (TG-Ab), and antithyroid-stimulating hormone receptor antibodies (TSHR-Ab) were determined by enzyme-linked immunosorbent assay. Sera of 312 patients (166 children and 146 adults) with T1D were analyzed. Sera of 276 healthy subjects (87 children and 189 blood donors) served as controls., Results: Out of 312 patients with T1D, 44 (14%) had ATA (TPO-Ab or TG-Ab or TSHR-Ab). The frequency of ATA in patients with T1D was significantly higher than in the control group (14% vs. 2.8%; p<10(-5)). ATA were significantly more frequent in adult patients with T1D than in the blood donor group (20% vs. 1.6%; p<10(-8)). The frequency of ATA in adult patients was significantly higher than in pediatric patients (20% vs. 9%; p=0.006). The frequency of TPO-Ab and TG-Ab was significantly higher in patients with T1D than in the control group (13.5% vs. 2%; p<10(-8) and 7% vs. 2.2%, p=0.008), respectively. Out of 312 patients with T1D, only one had TSHR-Ab. The simultaneous presence of three autoantibodies was found in one patient with T1D., Conclusion: ATA were frequent in patients with T1D. Serological screening of autoimmune thyroid disease is suggested in patients with T1D.
- Published
- 2012
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39. Repression of the genome organizer SATB1 in regulatory T cells is required for suppressive function and inhibition of effector differentiation.
- Author
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Beyer M, Thabet Y, Müller RU, Sadlon T, Classen S, Lahl K, Basu S, Zhou X, Bailey-Bucktrout SL, Krebs W, Schönfeld EA, Böttcher J, Golovina T, Mayer CT, Hofmann A, Sommer D, Debey-Pascher S, Endl E, Limmer A, Hippen KL, Blazar BR, Balderas R, Quast T, Waha A, Mayer G, Famulok M, Knolle PA, Wickenhauser C, Kolanus W, Schermer B, Bluestone JA, Barry SC, Sparwasser T, Riley JL, and Schultze JL
- Subjects
- 3' Untranslated Regions genetics, 3' Untranslated Regions immunology, Animals, Cell Differentiation drug effects, Chromatin Assembly and Disassembly drug effects, Flow Cytometry, Forkhead Transcription Factors genetics, Forkhead Transcription Factors metabolism, Gene Expression Profiling, Genome, Human, Genome-Wide Association Study, Humans, Lentivirus, Lymphocyte Activation drug effects, Matrix Attachment Region Binding Proteins genetics, Matrix Attachment Region Binding Proteins metabolism, Mice, Mice, Inbred C57BL, Mice, Knockout, MicroRNAs immunology, MicroRNAs metabolism, MicroRNAs pharmacology, RNA Interference, RNA, Small Interfering immunology, RNA, Small Interfering metabolism, RNA, Small Interfering pharmacology, Reverse Transcriptase Polymerase Chain Reaction, T-Lymphocytes, Regulatory cytology, T-Lymphocytes, Regulatory metabolism, Transduction, Genetic, Chromatin Assembly and Disassembly immunology, Forkhead Transcription Factors immunology, Gene Expression Regulation, Matrix Attachment Region Binding Proteins immunology, Self Tolerance drug effects, Self Tolerance genetics, Self Tolerance immunology, T-Lymphocytes, Regulatory immunology
- Abstract
Regulatory T cells (T(reg) cells) are essential for self-tolerance and immune homeostasis. Lack of effector T cell (T(eff) cell) function and gain of suppressive activity by T(reg) cells are dependent on the transcriptional program induced by Foxp3. Here we report that repression of SATB1, a genome organizer that regulates chromatin structure and gene expression, was crucial for the phenotype and function of T(reg) cells. Foxp3, acting as a transcriptional repressor, directly suppressed the SATB1 locus and indirectly suppressed it through the induction of microRNAs that bound the SATB1 3' untranslated region. Release of SATB1 from the control of Foxp3 in T(reg) cells caused loss of suppressive function, establishment of transcriptional T(eff) cell programs and induction of T(eff) cell cytokines. Our data support the proposal that inhibition of SATB1-mediated modulation of global chromatin remodeling is pivotal for maintaining T(reg) cell functionality.
- Published
- 2011
- Full Text
- View/download PDF
40. Anti-Saccharomyces cerevisiae antibodies are frequent in type 1 diabetes.
- Author
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Sakly W, Mankaï A, Sakly N, Thabet Y, Achour A, Ghedira-Besbes L, Jeddi M, and Ghedira I
- Subjects
- Adolescent, Adult, Age Factors, Child, Child, Preschool, Diabetes Mellitus, Type 1 immunology, Diabetes Mellitus, Type 1 microbiology, Enzyme-Linked Immunosorbent Assay, Female, Humans, Immunoglobulin A blood, Immunoglobulin G blood, Infant, Male, Middle Aged, Sex Factors, Antibodies, Fungal blood, Diabetes Mellitus, Type 1 blood, Saccharomyces cerevisiae immunology
- Abstract
Anti-Saccharomyces cerevisiae antibodies (ASCA) have been described in many autoimmune diseases in which there is an increased intestinal permeability. Also in type 1 diabetes (T1D), there is an increased intestinal permeability. Since no data are available about ASCA in T1D, we evaluated, retrospectively, the frequency of ASCA in this disease. ASCA, IgG, and IgA, were determined by ELISA in sera of 224 T1D patients in which coeliac disease has been excluded and 157 healthy control group. The frequency of ASCA (IgG or IgA) was significantly higher in T1D patients than in the control group (24.5% vs. 2.5%, p < 10(-7)). The same observation was found in children and in adult patients when we compare them to healthy children and blood donors group respectively. Compared to children, adult patients with T1D showed significantly higher frequencies of ASCA of any isotype (38% vs. 13.7%, p < 10(-4)), both ASCA IgG and IgA (12% vs. 1.6%, p = 0.002), ASCA IgG (35% vs. 9.8%, p < 10(-5)) and ASCA IgA (15% vs. 5.6%, p = 0.001). The frequency of ASCA was statistically higher in females of all T1D than in males (30.8% vs.17.7%, p = 0.03), in girls than in boys (22% vs.6.2%, p = 0.017), and significantly higher in men than in boys (35.7% vs. 6.2%, p < 10(-4)). The frequency of ASCA IgG was significantly higher than that of ASCA IgA in all T1D patients (21% vs. 9.8%, p < 0.002), in all females (26.5% vs. 10.2%, p < 0.002), in women (37.9% vs. 12%, p < 0.001). The frequency of ASCA was significantly higher in all long-term T1D than in an inaugural T1D (29% vs. 14.5%, p = 0.019). The same observation was found in adults (45.8% vs. 17.8%, p = 0.01). In long-term T1D patients, ASCA were significantly more frequent in adults than children (45.8% vs. 14.5%, p < 10(-4)). The frequency of ASCA IgG was significantly higher in long-term T1D than in an inaugural T1D (25.2% vs. 11.6%, p = 0.03). Patients with T1D had a high frequency of ASCA.
- Published
- 2010
- Full Text
- View/download PDF
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