16 results on '"H. Bekkari"'
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2. Stress adaptation and low-frequency impedance of rat lungs
- Author
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H. Bekkari, C. Gallina, R. Peslin, C. Duvivier, and E. Reichart
- Subjects
Male ,medicine.medical_specialty ,Physiology ,Analytical chemistry ,Low frequency ,Plasticity ,Models, Biological ,Viscoelasticity ,Stress (mechanics) ,Airway resistance ,Stress, Physiological ,Physiology (medical) ,Pi ,medicine ,Stress relaxation ,Animals ,Lung ,Air Pressure ,Viscosity ,Chemistry ,Rats, Inbred Strains ,Adaptation, Physiological ,Elasticity ,Rats ,Surgery ,Delta-v (physics) - Abstract
At transpulmonary pressures (Ptp) of 7-12 cmH2O, pressure-volume hysteresis of isolated cat lungs has been found to be 20-50% larger than predicted from their amount of stress adaptation (J. Hildebrandt, J. Appl. Physiol. 28: 365-372, 1970). This behavior is inconsistent with linear viscoelasticity and has been interpreted in terms of plastoelasticity. We have reinvestigated this phenomenon in isolated lungs from 12 Wistar rats by measuring 1) the changes in Ptp after 0.5-ml step volume changes (initial Ptp of 5 cmH2O) and 2) their response to sinusoidal pressure forcing from 0.01 to 0.67 Hz (2 cmH2O peak to peak, mean Ptp of 6 cmH2O). Stress adaptation curves were found to fit approximately Hildebrandt's logarithmic model [delta Ptp/delta V = A - B.log(t)] from 0.2 to 100 s, where delta V is the step volume change, A and B are coefficients, and t is time. A and B averaged 1.06 +/- 0.11 and 0.173 +/- 0.019 cmH2O/ml, respectively, with minor differences between stress relaxation and stress recovery curves. The response to sinusoidal forcing was characterized by the effective resistance (Re) and elastance (EL). Re decreased from 2.48 +/- 0.41 cmH2O.ml-1.s at 0.01 Hz to 0.18 +/- 0.03 cmH2O.ml-1.s at 0.5 Hz, and EL increased from 0.99 +/- 0.10 to 1.26 +/- 0.20 cmH2O/ml on the same frequency range. These data were analyzed with the frequency-domain version of the same model, complemented by a Newtonian resistance (R) to account for airway resistance: Re = R + B/ (9.2f) and EL = A + 0.25B + B . log 2 pi f, where f is the frequency.(ABSTRACT TRUNCATED AT 250 WORDS)
- Published
- 1990
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3. In-depth exploration of differences of sex development: 5-year experience in a tertiary center.
- Author
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Hssaini M, Abourazzak S, El Otmani I, Ahakoud M, Ameli A, Bouguenouch L, and Bekkari H
- Abstract
Background: Differences/disorders of sex development (DSD) encompass a wide range of conditions. Their clinical spectrum and etiological diagnosis have not been reported in Moroccan patients., Aims: The study aims to highlight the clinical spectrum, etiological diagnosis, and management of patients with DSD., Subjects and Methods: This is a retrospective study of all patients diagnosed with DSD under the age of 18 years, who were referred to the Pediatric Endocrinology Department and the Medical Genetics Laboratory at HASSAN II University Hospital of Fez between June 2018 and June 2023., Results: Out of 57 patients, 54.4% (n = 31) were diagnosed with 46,XX DSD, the most common type, while 45.6% (n = 26) had 46,XY DSD. Patients with 46,XX DSD presented earlier than those with 46,XY DSD, at a median age of 0.08 years and 0.96 years, respectively. The most commonly reported complaint was atypical genitalia. At the first presentation, the sex of rearing was already assigned to 26 males and 27 females. All patients with 46,XX DSD were diagnosed with congenital adrenal hyperplasia (CAH) at a median age of diagnosis of 0.92 years. Of these, 11 patients were raised as males. Disorders of androgen action or synthesis were more common in XY patients (69.2%). The consanguinity rate was 46.5%, and there were 19 cases with a positive family history, with 10 siblings having died., Conclusion: DSD are not rare in Morocco. Overall, CAH remains the most frequent DSD etiology. Molecular genetic analyses are needed to determine the accurate etiological distribution of DSD, especially in XY patients.
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- 2024
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4. Study of Clinical Characteristics of Intellectual Disability in Morocco.
- Author
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Bekkari H, Benmakhlouf Y, Nourouti NG, Barakat A, and Mechita MB
- Abstract
Objective: Intellectual disability (ID) is considered one of the most common human disorders characterized by significant deficits in cognition and functional and adaptive skills. The aims of this study were to describe the demographic and clinical features of a group of Moroccan individuals with ID living in the Tangier-Tetouan region., Design: This was a retro-prospective and descriptive exploratory monocentric study realized between November 2020 and August 2023. A total of 109 patients with ID were included. They were selected at four mental health centers in the Tangier-Tetouan region. Our data were treated and analyzed using the IBM SPSS version 26., Results: A male predominance of patients with ID was observed in our series (54.4% male vs. 42.6% female). The male-to-female ratio was 1.34. The mean±standard deviation (SD) age of our patients was 11.75±4.87 years, ranging from 1 to 35 years. The mean ages of mothers and fathers at the births of their children with ID were 28.36 and 35.6 years, respectively. Many co-occurring medical conditions were noted in our data (speech delay: 20.5%, concentration problems: 15.1%, hyperactivity: 11.1%, ambulation difficulties: 8.8%, aggressiveness: 8%, vision problems: 6.3%, epileptic seizures: 4%). The consanguinity rate was 26.9 percent., Conclusion: ID associated with genetic causes was significantly correlated with the consanguinity rate in the Moroccan population., Competing Interests: DISCLOSURES: The authors have no conflicts of interest relevant to the content of this article., (Copyright © 2024. Matrix Medical Communications. All rights reserved.)
- Published
- 2024
5. A Case Report of a Rare 46,XX/47,XXY Mosaicism With Ovotesticular Disorder of Sex Development and a Literature Review.
- Author
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Hssaini M, Bourkadi G, Ahakoud M, Bouguenouch L, Abourazzak S, Bekkari H, and Ameli A
- Abstract
Klinefelter syndrome (KS) is a common chromosomal abnormality in males, usually presenting as a 47,XXY karyotype and often underdiagnosed. Rarely, KS occurs as mosaic 46,XX/47,XXY. At the same time, ovotesticular disorder of sex development (OT-DSD) is also a rare condition in which both ovarian and testicular structures are present in the same individual, often associated with a 46,XX karyotype. The combination of mosaic 46,XX/47,XXY with OT-DSD is scarce. Herein, we report a new case of a six-month-old infant with unilateral OT-DSD and a 46,XX/47,XXY mosaic karyotype who presented with atypical genitalia at birth. On examination, the external genitalia showed asymmetry of the labioscrotal folds, an empty right fold, a 2.5 cm phallic structure, and a perineal urethral meatus. Imaging studies revealed a uterus and a vaginal cavity, as well as an ovotestis on the left side and an ovarian remnant on the right side. An unexpected increase in testosterone level was observed. Cytogenetics analysis confirmed a mosaic karyotype with 54% of 46,XX and 46% 47,XXY cells. Molecular genetic analysis revealed no mutations in the genes involved in gonadal development. These findings are discussed and the clinical characteristics of the reported cases of 46,XX/47,XXY with OT-DSD are summarized. In conclusion, atypical genitalia leads to the early diagnosis of the rare 46,XX/47,XXY mosaicism with OT-DSD. Mosaicism should be considered in all cryptorchidism cases. Persistent Müllerian structures were common, and the nearly male phenotype of the external genitalia led parents to prefer the male sex of rearing., Competing Interests: Human subjects: Consent was obtained or waived by all participants in this study. Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work., (Copyright © 2024, Hssaini et al.)
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- 2024
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6. Extracellular Vesicles Derived from Opuntia ficus-indica Fruit (OFI-EVs) Speed Up the Normal Wound Healing Processes by Modulating Cellular Responses.
- Author
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Valentino A, Conte R, Bousta D, Bekkari H, Di Salle A, Calarco A, and Peluso G
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- Humans, Cytokines metabolism, Cell Movement drug effects, Oxidative Stress drug effects, THP-1 Cells, Opuntia chemistry, Extracellular Vesicles metabolism, Extracellular Vesicles chemistry, Wound Healing drug effects, Fruit chemistry, Fibroblasts metabolism, Fibroblasts drug effects
- Abstract
Plant-derived extracellular vesicles (EVs) have been recognized as important mediators of intercellular communication able to transfer active biomolecules across the plant and animal kingdoms. EVs have demonstrated an impressive array of biological activities, displaying preventive and therapeutic potential in mitigating various pathological processes. Indeed, the simplicity of delivering exogenous and endogenous bioactive molecules to mammalian cells with their low cytotoxicity makes EVs suitable agents for new therapeutic strategies for a variety of pathologies. In this study, EVs were isolated from Opuntia ficus-indica fruit (OFI-EVs) and characterized by particle size distribution, concentration, and bioactive molecule composition. OFI-EVs had no obvious toxicity and demonstrated a protective role in the inflammatory process and oxidative stress in vitro model of chronic skin wounds. The results demonstrated that pretreatment with OFI-EVs decreased the activity and gene expression of pro-inflammatory cytokines (IL-6, IL-8, and TNF-α) in the LPS-stimulated human leukemia monocytic cell line (THP-1). Furthermore, OFI-EVs promote the migration of human dermal fibroblasts (HDFs), speeding up the normal wound healing processes. This study sheds light, for the first time, on the role of OFI-EVs in modulating important biological processes such as inflammation and oxidation, thereby identifying EVs as potential candidates for healing chronic cutaneous wounds.
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- 2024
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7. Influence of CYP450 Enzymes and ABCB1 Polymorphisms on Clopidogrel Response in Moroccan Patients with Acute Coronary Syndromes.
- Author
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Mouhrach I, Bouguenouch L, Kamal A, Meriame A, El Khorb N, El Azami El Idrissi M, Akoudad H, and Bekkari H
- Abstract
Introduction: Clopidogrel is an antiplatelet prodrug primarily prescribed to prevent or treat acute coronary syndrome (ACS) or acute ischemic stroke (IS), polymorphisms of genes encoding cytochrome P-450 (CYP) and P-glycoprotein transporter, could affect the efficiency of clopidogrel absorption and biotransformation, especially during the first critical hours following its administration., Methods: The present study was designed to investigate the potential association of clopidogrel responsiveness and 14 polymorphisms in the genes encoding the CYPs (CYP2C9, 2C19, 3A4, 3A5, 1A2, and 2B6), the ATP binding cassette subfamily B member 1 (ABCB1). Platelet aggregation activity was measured after 8h of 300mg clopidogrel administration for fifty-five ACS patients., Results: There was no significant association between polymorphism of the studied CYPs and clopidogrel responsiveness (P>0.05). The frequency of the ABCB1 3435 T allele in clopidogrel non-responders was higher (78.9%) compared to responders (52.8%), but this difference was not significant (P=0.057). Demographic characteristics, comorbidities, concomitant treatments were not associated with clopidogrel response., Discussion: There was no effect of the studied genetic variations and demographic factors on the platelet activity of clopidogrel in Moroccan ACS patients., Competing Interests: The authors report no conflicts of interest in this work., (© 2023 Mouhrach et al.)
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- 2023
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8. FLT3 Mutations in Acute Myeloid Leukemia: Unraveling the Molecular Mechanisms and Implications for Targeted Therapies.
- Author
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Jalte M, Abbassi M, El Mouhi H, Daha Belghiti H, Ahakoud M, and Bekkari H
- Abstract
Acute myeloid leukemia (AML) is a heterogeneous and aggressive form of blood cancer characterized by the uncontrolled proliferation of myeloid precursor cells in the bone marrow. It affects individuals of all ages, with incidence increasing notably in those over 65 years old. Despite advancements in treatment, overall survival rates remain unsatisfactory, underscoring the need for a deeper understanding of the disease. Among the various genetic alterations implicated in AML pathogenesis, mutations in the FLT3 (Fms-like tyrosine kinase 3) gene have emerged as significant contributors to leukemogenesis. The FLT3 gene encodes a type III receptor tyrosine kinase crucial in regulating normal hematopoiesis. Approximately one-third of AML patients carry FLT3 mutations, making it one of the most frequently mutated genes in the disease. FLT3 mutations can be classified into internal tandem duplications (ITDs) and point mutations in the tyrosine kinase domain (TKD). FLT3 mutations are associated with adverse clinical features and are independent prognostic factors for poor overall survival and decreased remission rates in AML patients. Understanding the molecular mechanisms underlying FLT3 mutations in AML is critical for improving risk stratification, prognosis assessment, and the development of targeted therapies. By reviewing the current literature, this study aims to elucidate the functional consequences of FLT3 mutations in AML pathogenesis, explore the interaction of FLT3 signaling with other oncogenic pathways, and assess the prognostic significance of FLT3 mutations in clinical practice, providing information that can guide future research directions and facilitate the development of more effective therapeutic strategies., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2023, Jalte et al.)
- Published
- 2023
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9. Review of prostate cancer genomic studies in Africa.
- Author
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Samtal C, El Jaddaoui I, Hamdi S, Bouguenouch L, Ouldim K, Nejjari C, Ghazal H, and Bekkari H
- Abstract
Prostate cancer (PCa) is the second most commonly diagnosed in men worldwide and one of the most frequent cancers in men in Africa. The heterogeneity of this cancer fosters the need to identify potential genetic risk factors/biomarkers. Omics variations may significantly contribute to early diagnosis and personalized treatment. However, there are few genomic studies of this disease in African populations. This review sheds light on the status of genomics research on PCa in Africa and outlines the common variants identified thus far. The allele frequencies of the most significant SNPs in Afro-native, Afro-descendants, and European populations were compared. We advocate how these few but promising data will aid in understanding, better diagnosing, and precisely treating this cancer and the need for further collaborative research on the genomics of PCa in the African continent., 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 Samtal, El Jaddaoui, Hamdi, Bouguenouch, Ouldim, Nejjari, Ghazal and Bekkari.)
- Published
- 2022
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10. Combination of Catechin, Epicatechin, and Rutin: Optimization of a novel complete antidiabetic formulation using a mixture design approach.
- Author
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Mechchate H, Es-Safi I, Haddad H, Bekkari H, Grafov A, and Bousta D
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- Administration, Oral, Animals, Anti-Inflammatory Agents pharmacology, Antioxidants pharmacology, Blood Glucose analysis, Catechin administration & dosage, Diabetes Mellitus, Experimental metabolism, Drug Combinations, Female, Flavonoids pharmacology, Glucose Tolerance Test methods, Hyperglycemia prevention & control, Hypoglycemic Agents administration & dosage, Male, Mice, Rutin administration & dosage, Catechin pharmacology, Diabetes Mellitus, Experimental drug therapy, Hypoglycemic Agents pharmacology, Rutin pharmacology
- Abstract
Nowadays, synthetic chemical antidiabetic drugs, besides their therapeutic effects, present adverse effects that could be hard to handle over time. In the last decade, studies reported new alternative molecules with more health benefits and less adverse effects. The goal of this study is to optimize a new antidiabetic formulation using plant flavonoids: Catechin, Epicatechin, and Rutin. They are also a powerful antioxidant and anti-inflammatory molecules. A mixture design experiment will optimize their combination to obtain a new, safe multi-targets antidiabetic formulation making it a powerful combination for the management of diabetes and its complications. To study the variation of blood glucose level in response to the treatment over the time we performed an Oral Glucose Tolerance Test. The blood glucose level variations recorded as responses for the mixture design experiment. We used the molecules at a dose of 10 mg/kg. According to the software analysis, the prediction profiler showed us the optimum combination, and the result was a binary combination between Rutin and Epicatechin (25% and 75%, respectively). This combination prevented hyperglycemia and hypoglycemia, along with the best area under the curve, and after that, we validated it through a repeated oral administration on alloxan-induced diabetic mice for 28 d. Rutin, Catechin, and Epicatechin exhibit a potent antihyperglycemic activity, their synergistic combination validates a new formulation that could be a real candidate to conventional drugs., Competing Interests: Declaration of competing interest The authors declare that they have no conflict of interest., (Copyright © 2020. Published by Elsevier Inc.)
- Published
- 2021
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11. Antioxidant, Anti-Inflammatory and Antidiabetic Proprieties of LC-MS/MS Identified Polyphenols from Coriander Seeds.
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Mechchate H, Es-Safi I, Amaghnouje A, Boukhira S, A Alotaibi A, Al-Zharani M, A Nasr F, M Noman O, Conte R, Amal EHEY, Bekkari H, and Bousta D
- Subjects
- Animals, Chromatography, Liquid, Diabetes Mellitus, Experimental pathology, Hyperglycemia prevention & control, Mice, Rats, Rats, Wistar, Seeds chemistry, Tandem Mass Spectrometry, Antioxidants pharmacology, Coriandrum chemistry, Diabetes Mellitus, Experimental drug therapy, Hypoglycemic Agents pharmacology, Hypolipidemic Agents pharmacology, Plant Extracts pharmacology, Polyphenols pharmacology
- Abstract
Coriandrum sativum L. seeds are traditionally used to treat diabetes and its complications (inflammation and formation of reactive oxygen species) around the world. The present study investigates the antidiabetic, anti-inflammatory, and antioxidant effects of the polyphenol fraction of Coriandrum sativum seeds (PCS). Diabetic mice were orally administered with PCS (25 and 50 mg/kg b.w.) for 28 days. Oral glucose tolerance (OGTT) was also evaluated along with the anti-inflammatory effect, assessed by measuring paw edema development induced with carrageenan in Wistar rat and the antioxidant activity assessed using two tests (β-carotene discoloration and DPPH). Treatment of diabetic mice with PCS for four weeks managed their high fasting blood glucose levels, improved their overall health, also revealed an excellent antihyperlipidemic activity. The OGTT result showed a potent antihyperglycemic activity, and following the anti-inflammatory and antioxidant effects, the PCS exhibited a perfect activity. LC-MS/MS result revealed the presence of 9 polyphenols. This modest work indicates that the PCS have an important antidiabetic, antihyperglycemic, antihyperlipidemic, anti-inflammatory, and antioxidant effect that can be well established treatment of diabetes and its complications.
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- 2021
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12. In Vitro Alpha-Amylase and Alpha-Glucosidase Inhibitory Activity and In Vivo Antidiabetic Activity of Withania frutescens L. Foliar Extract.
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Mechchate H, Es-Safi I, Louba A, Alqahtani AS, Nasr FA, Noman OM, Farooq M, Alharbi MS, Alqahtani A, Bari A, Bekkari H, and Bousta D
- Subjects
- Animals, Diabetes Mellitus, Experimental enzymology, Mice, Diabetes Mellitus, Experimental drug therapy, Glycoside Hydrolase Inhibitors chemistry, Glycoside Hydrolase Inhibitors pharmacology, Hypoglycemic Agents chemistry, Hypoglycemic Agents pharmacology, Plant Extracts chemistry, Plant Extracts pharmacology, Plant Leaves chemistry, Withania chemistry, alpha-Amylases antagonists & inhibitors
- Abstract
Withania frutescens L. is a wild perennial woody plant used by the local population for diverse therapeutic purposes. This work aims to study for the first time the potential inhibitory effect of this plant hydroethanolic extract on α-amylase and α-glucosidase activities using in vitro methods and its antidiabetic and antihyperglycemic activities using alloxan-induced diabetic mice as a model for experimental diabetes. Two doses were selected for the in vivo study (200 and 400 mg/kg) and glibenclamide, a well-known antidiabetic drug (positive control) in a subacute study (28 days) where the antihyperglycemic activity was also assessed over a period of 12 h on diabetic mice. The continuous treatment of diabetic mice with the extract of Withania frutescens for 4 weeks succeeded to slowly manage their high fasting blood glucose levels (after two weeks), while the antihyperglycemic test result revealed that the extract of this plant did not control hyperglycemia in the short term. No toxicity signs or death were noted for the groups treated with the plant extract, and it shows a protective effect on the liver and kidney. The in vitro assays demonstrated that the inhibition of alpha-amylase and alpha-glucosidase might be one of the mechanisms of action exhibited by the extract of this plant to control and prevent postprandial hyperglycemia. This work indicates that W. frutescens have an important long term antidiabetic effect that can be well established to treat diabetes.
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- 2021
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13. In-Vivo Antidiabetic Activity and In-Silico Mode of Action of LC/MS-MS Identified Flavonoids in Oleaster Leaves.
- Author
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Mechchate H, Es-Safi I, Bourhia M, Kyrylchuk A, El Moussaoui A, Conte R, Ullah R, Ezzeldin E, Mostafa GA, Grafov A, Bekkari H, and Bousta D
- Subjects
- Animals, Computer Simulation, Mice, Diabetes Mellitus, Experimental drug therapy, Diabetes Mellitus, Experimental metabolism, Diabetes Mellitus, Experimental pathology, Flavonoids chemistry, Flavonoids pharmacology, Hypoglycemic Agents chemistry, Hypoglycemic Agents pharmacology, Models, Biological, Olea chemistry, Plant Leaves chemistry
- Abstract
Background: Olea europea L. subsp. europaea var. sylvestris (Mill) Lehr (Oleaster) is a wild endemic olive tree indigenous to the Mediterranean region. Olea europea leaves represent a natural reservoir of bioactive molecules that can be used for therapeutic purposes., Aim of the Study: This work was conducted to study antidiabetic and antihyperglycemic activities of flavonoids from oleaster leaves using alloxan-induced diabetic mice. The mode of action of flavonoids against eight receptors that have a high impact on diabetes management and complication was also investigated using molecular docking., Results: During 28 days of mice treatment with doses 25 and 50 mg/kg b.w, the studied flavonoids managed a severe diabetic state (<450 mg/dL), exhibiting a spectacular antidiabetic and antihyperglycemic activity, and improved mice health status compared to diabetic control. The in-silico mode of action of oleaster flavonoids revealed the inhibition of protein tyrosine phosphatase 1B (PTP1B), Dipeptidyl-peptidase 4 (DPP4), α-Amylase (AAM), α-Glucosidase inhibition, Aldose reductase (AldR), Glycogen phosphorylase (GP), and the activation of free fatty acid receptor 1 (FFAR1)., Conclusion: The findings obtained in the present work indicate that the flavonoids from the oleaster may constitute a safe multi-target remedy to treat diabetes.
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- 2020
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14. Thermostable Cellulases from the Yeast Trichosporon sp.
- Author
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Touijer H, Benchemsi N, Ettayebi M, Janati Idrissi A, Chaouni B, and Bekkari H
- Abstract
Objectives: Identification of cellulolytic microorganisms is of great interest to the hydrolysis of cellulosic biomass. This study focuses on the identification of cellulolytic yeasts and the optimization of cellulase activities produced by the best performing isolate., Results: 30 cellulolytic yeast isolates were selected. Enzymes produced by an isolate from the Trichosporon genus showed the property to hydrolyze different substrates: carboxymethyl cellulose (CMC), cellulose fiber, and filter paper (FP). The optimum measured temperature was 55°C for CMCase and 60°C for FPase. The optimal pH was 5 for CMCase and 4 to 6 for FPase. The effect of the substrates concentration showed that the best activities were obtained at 100 mg/mL CMC or FP. The highest activities were 0.52 for the CMCase and 0.56 for the cellulase fiber at 10 min incubation, 0.44 IU/mL at 15 min incubation, and 24 h FPase preincubation., Conclusion: Cellulases produced by the studied yeast are capable of hydrolyzing soluble and insoluble substrates at elevated temperatures and at a wide pH range. They are considerable interest in the production of fermentable sugars from lignocellulosic substrates.
- Published
- 2019
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15. Expression of secreted recombinant human insulin-like growth factor-II (IGF-II) in Chinese hamster ovary cells.
- Author
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Bekkari H, Sekkat D, Straczek J, Hess K, Belleville-Nabet F, and Nabet P
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- Animals, Base Sequence, CHO Cells metabolism, Cricetinae, DNA, Complementary analysis, DNA, Complementary genetics, Humans, Insulin-Like Growth Factor II genetics, Insulin-Like Growth Factor II isolation & purification, Molecular Sequence Data, Recombinant Proteins isolation & purification, Insulin-Like Growth Factor II biosynthesis, Recombinant Proteins biosynthesis
- Abstract
Chinese hamster ovary (CHO-KI) cells were cotransfected with a plasmid pcDNAI containing the human preproinsulin-like growth factor II cDNA linked downstream to the human cytomegalovirus promoter and with a plasmid containing the neomycin resistance gene (pMAM-neo). CHO neo+ were selected by growth in medium supplemented with G418 geneticin. After amplification, the neomycin-resistant clones were screened for IGF-II production. IGF-II produced was identified by dot blot and quantified by ELISA. The clones C24, C40 and C94 secreted IGF-II at about 350-400 ng per 10(6) cells per day. DNA analysis of C24 and C40 CHO cells by PCR demonstrated the presence of the IGF-II construct in the transfected cells, presumably integrated into the chromosomal DNA. IGF-II produced by CHO cells and purified by RP-HPLC was a mitogen for MCF-7 stimulating mitosis 2-fold.
- Published
- 1994
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16. Stress adaptation and low-frequency impedance of rat lungs.
- Author
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Peslin R, Duvivier C, Bekkari H, Reichart E, and Gallina C
- Subjects
- Adaptation, Physiological physiology, Air Pressure, Animals, Elasticity, Male, Models, Biological, Rats, Rats, Inbred Strains, Viscosity, Lung physiopathology, Stress, Physiological physiopathology
- Abstract
At transpulmonary pressures (Ptp) of 7-12 cmH2O, pressure-volume hysteresis of isolated cat lungs has been found to be 20-50% larger than predicted from their amount of stress adaptation (J. Hildebrandt, J. Appl. Physiol. 28: 365-372, 1970). This behavior is inconsistent with linear viscoelasticity and has been interpreted in terms of plastoelasticity. We have reinvestigated this phenomenon in isolated lungs from 12 Wistar rats by measuring 1) the changes in Ptp after 0.5-ml step volume changes (initial Ptp of 5 cmH2O) and 2) their response to sinusoidal pressure forcing from 0.01 to 0.67 Hz (2 cmH2O peak to peak, mean Ptp of 6 cmH2O). Stress adaptation curves were found to fit approximately Hildebrandt's logarithmic model [delta Ptp/delta V = A - B.log(t)] from 0.2 to 100 s, where delta V is the step volume change, A and B are coefficients, and t is time. A and B averaged 1.06 +/- 0.11 and 0.173 +/- 0.019 cmH2O/ml, respectively, with minor differences between stress relaxation and stress recovery curves. The response to sinusoidal forcing was characterized by the effective resistance (Re) and elastance (EL). Re decreased from 2.48 +/- 0.41 cmH2O.ml-1.s at 0.01 Hz to 0.18 +/- 0.03 cmH2O.ml-1.s at 0.5 Hz, and EL increased from 0.99 +/- 0.10 to 1.26 +/- 0.20 cmH2O/ml on the same frequency range. These data were analyzed with the frequency-domain version of the same model, complemented by a Newtonian resistance (R) to account for airway resistance: Re = R + B/ (9.2f) and EL = A + 0.25B + B . log 2 pi f, where f is the frequency.(ABSTRACT TRUNCATED AT 250 WORDS)
- Published
- 1990
- Full Text
- View/download PDF
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