Nadia Soudani

Cigarette Smoking-Induced Cardiac Hypertrophy, Vascular Inflammation and Injury Are Attenuated by Antioxidant Supplementation in an Animal Model

Background: Cardiovascular diseases are the leading causes of morbidity and mortality worldwide. Cigarette smoking remains a global health epidemic with associated detrimental effects on the cardiovascular system. In this work, we investigated the effects of cigarette smoke exposure on cardiovascular system in an animal model. The study then evaluated the effects of antioxidants (AO), represented by pomegranate juice, on cigarette smoke induced cardiovascular injury. This study aims at evaluating the effect of pomegranate juice supplementation on the cardiovascular system of an experimental rat model of smoke exposure. Methods: Adult rats were divided into four different groups: Control, Cigarette smoking (CS), AO, and CS + AO. Cigarette smoke exposure was for 4 weeks (5 days of exposure/week) and AO group received pomegranate juice while other groups received placebo. Assessment of cardiovascular injury was documented by assessing different parameters of cardiovascular injury mediators including: (1) cardiac hypertrophy, (2) oxidative stress, (3) expression of inflammatory markers, (4) expression of Bradykinin receptor 1 (Bdkrb1), Bradykinin receptor 2 (Bdkrb2), and (5) altered expression of fibrotic/atherogenic markers [(Fibronectin (Fn1) and leptin receptor (ObR))]. Results: Data from this work demonstrated that cigarette smoke exposure induced cardiac hypertrophy, which was reduced upon administration of pomegranate in CS + AO group. Cigarette smoke exposure was associated with elevation in oxidative stress, significant increase in the expression of IL-1β, TNFα, Fn1, and ObR in rats aorta. In addition, an increase in aortic calcification was observed after 1 month of cigarette smoke exposure. Furthermore, cigarette smoke induced a significant up regulation in Bdkrb1 expression level. Finally, pomegranate supplementation exhibited cardiovascular protection assessed by the above findings and partly contributed to ameliorating cardiac hypertrophy in cigarette smoke exposed animals. Conclusion: Findings from this work showed that cigarette smoking exposure is associated with significant cardiovascular pathology such as cardiac hypertrophy, inflammation, pro-fibrotic, and atherogenic markers and aortic calcification in an animal model as assessed 1 month post exposure. Antioxidant supplementation prevented cardiac hypertrophy and attenuated indicators of atherosclerosis markers associated with cigarette smoke exposure.

Toward an Arabic Ontology for Arabic Word Sense Disambiguation Based on Normalized Dictionaries

In this paper, we propose an approach for constructing Arabic Ontology based on normalized dictionaries. This approach mainly consists in transforming non structured Arabic dictionaries into LMF Lexical Markup Framework based-normalized ones. We are basically exploiting Arabic dictionaries of Hadith for experimentation. Then, from an Arabic normalized dictionary of Hadith, an ontology will be constructed. It represents hidden knowledge in Hadith texts. It will be next integrated into an information retrieval and navigation system. We will take advantage of it to semantically disambiguate Arabic terms of both the formulated user query and/or the Arabic texts with application on texts of Hadith.

Mechanical stretch-induced vascular hypertrophy occurs through modulation of leptin synthesis-mediated ROS formation and GATA-4 nuclear translocation.

Background: Obesity and hypertension are associated with increased leptin production contributing to cardiovascular remodeling. Mechanisms involving mechanical stretch-induced leptin production and the cross talk between signaling pathways leading to vascular remodeling have not been fully elucidated. Methods and Results: Rat portal vein (RPV) organ culture was used to investigate the effect of mechanical stretch on leptin protein expression in vascular smooth muscle cells (VSMCs). Moreover, the involvement of reactive oxygen species (ROS), the RhoA/ROCK pathway, actin cytoskeleton dynamics and the transcriptional factor GATA-4 activation in mechanical stretch-induced vascular remodeling were investigated. Stretching the RPV for 1 or 24 h significantly increased leptin protein level and ROS formation in VSMCs, which was prevented by 1 h pretreatment with the ROCK inhibitor Y-27632 and the actin cytoskeleton depolymerization agent cytochalasin D. Moreover, Western blotting and immunohistochemistry revealed that mechanical stretch or treatment with 3.1 nmol/L leptin for 24 h significantly increased actin polymerization, as reflected by an increase in the F-actin to G-actin ratio. Increases in blood vessels’ wet weight and [3H]-leucine incorporation following a 24 h treatment with conditioned media from cultured stretched RPVs indicated RPV hypertrophy. This effect was prevented by 1 h pretreatment with anti-leptin antibody, indicating leptin’s crucial role in promoting VSMC hypertrophy. As an index of GATA-4 activation, GATA-4 nuclear translocation was assessed by immunohistochemistry method. Pretreating VSMC with leptin for 1 h significantly activated GATA-4 nuclear translocation, which was potently attenuated by the NADPH oxidase inhibitor apocynin, Y-27632, and cytochalasin D. Conclusion: Our results demonstrate that ROS formation, RhoA/ROCK pathway, and GATA-4 activation play a pivotal role in mechanical stretch-induced leptin synthesis leading to VSMC remodeling.

Characterization of astrovirus-associated gastroenteritis in hospitalized children under five years of age

PURPOSE The aim of this study was to determine the incidence and genetic diversity of astrovirus (AstV) detected in children hospitalized for gastroenteritis (GE). METHODS A multi-center, hospital-based surveillance study was conducted across Lebanon to investigate the incidence of AstV among diarrheal hospitalizations. Viral RNA was extracted from stool samples collected between 2011 and 2013 from children, below the age of 5years, hospitalized for GE at six medical centers across Lebanon. Demographic and clinical data were collected and analyzed. RNA of eligible samples (n=739) was screened by two AstV-specific PCR assays followed by genotype-specific PCR. Sanger sequencing and phylogenetic analysis were performed for genotypic characterization. RESULTS Overall, 5.5% (41/739) of rotavirus-negative stool samples collected from hospitalized children <5years old tested positive for AstV infection. AstV infections were detected all year long. Diarrhea, dehydration, vomiting and fever were the most common symptoms associated with AstV infections. Children aged 48-59months had the highest incidence of AstV. Using the Vesikari Scoring System to assess clinical severity, 85.4% of children with AstV had a score>11, indicating severe GE. Genotype-specific PCR identified 22 classical and 4 MLB-like AstV specimens. Further sequencing and phylogenetic analysis of orf1b and orf2 genes revealed that AstV classical 1-3, 5, 6, and 8, MLB-1, VA-1 and -2 genotypes circulated in Lebanon. Recombination between classical AstV strains was detected in several cases as evident by the lack of congruency in the tree topologies of the orf1b and orf2. Two cases of mixed infections between classical and non-classical genotypic strains were recorded. CONCLUSION High genetic diversity was detected among AstVs in Lebanon. AstVs are associated with 5.5% of non-rotavirus GE-associated hospitalizations in children under five years in Lebanon.

Semantic Information Retrieval: A Comparative Experimental Study of NLP Tools and Language Resources for Arabic

In this paper, we try to exploit the semantic richness of Arabic language for Information Retrieval (IR). The semantics of Arabic words may be extracted from dictionaries or corpora, which are analyzed and minded using Natural Language Processing (NLP) and text mining tools. This allows modeling the contextual dependencies between words, which help identify the meaning of queries in the search process. Thus, the queries are enriched by semantic knowledge, which enhances search performance. In this context, this paper describes a text mining-based approach for Arabic semantic IR, which considers senses of query terms. Experiments and results based on a standard Arabic Test collection are discussed through this communication. In the one hand, we compare dictionary versus corpus-based approaches for modeling semantics. On the other hand, we compare some Arabic NLP tools in the preprocessing step. Thus, we study the effect of Arabic morphology on the semantic interpretation of queries.

Calcineurin/NFAT Activation-Dependence of Leptin Synthesis and Vascular Growth in Response to Mechanical Stretch

Background and Aims: Hypertension and obesity are important risk factors of cardiovascular disease. They are both associated with high leptin levels and have been shown to promote vascular hypertrophy, through the RhoA/ROCK and ERK1/2 phosphorylation. Calcineurin/NFAT activation also induces vascular hypertrophy by upregulating various genes. This study aimed to decipher whether a crosstalk exists between the RhoA/ROCK pathway, Ca2+/calcineurin/NFAT pathway, and ERK1/2 phosphorylation in the process of mechanical stretch-induced vascular smooth muscle cell (VSMC) hypertrophy and leptin synthesis. Methods and Results: Rat portal vein (RPV) organ culture was used to investigate the effect of mechanical stretch and exogenous leptin (3.1 nM) on VSMC hypertrophy and leptin synthesis. Results showed that stretching the RPV significantly upregulated leptin secretion, mRNA, and protein expression, which were inhibited by the calcium channel blocker nifedipine (10 μM), the selective calcineurin inhibitor FK506 (1 nM), and the ERK1/2 inhibitor PD98059 (1 μM). The transcription inhibitor actinomycin D (0.1 μM) and the translation inhibitor cycloheximide (1 mM) significantly decreased stretch-induced leptin protein expression. Mechanical stretch or leptin caused an increase in wet weight changes and protein synthesis, considered as hypertrophic markers, while they were inhibited by FK506 (0.1 nM; 1 nM). In addition, stretch or exogenous leptin significantly increased calcineurin activity and MCIP1 expression whereas leptin induced NFAT nuclear translocation in VSMCs. Moreover, in response to stretch or exogenous leptin, the Rho inhibitor C3 exoenzyme (30 ng/mL), the ROCK inhibitor Y-27632 (10 μM), and the actin depolymerization agents Latrunculin B (50 nM) and cytochalasin D (1 μM) reduced calcineurin activation and NFAT nuclear translocation. ERK1/2 phosphorylation was inhibited by FK506 and C3. Conclusions: Mechanical stretch-induced VSMC hypertrophy and leptin synthesis and secretion are mediated by Ca2+/calcineurin/NFAT activation. RhoA/ROCK and ERK1/2 activation are critical for mechanical stretch-induced calcineurin activation.

Characterization of influenza outbreaks in Lebanon during the 2013/14 and 2014/15 seasons.

Despite the significant burden of influenza outbreaks, active disease monitoring has been largely absent in the Middle East, including Lebanon. In this study we characterized influenza virus in 440 nasopharyngeal swabs collected from patients with acute respiratory infections during two influenza seasons in Lebanon. Influenza A(H3N2) was dominant in the 2013/14 season while the A(H1N1)pdm09 and B/Yamagata strains were most prevalent in the 2014/15 season. All tested isolates were susceptible to 4 neuraminidase inhibitors (oseltamivir, zanamivir, peramivir and laninamivir). Genetic analysis of the haemagglutinin gene revealed multiple introductions of influenza viruses into Lebanon from different geographic sources during each season. Additionally, large data gaps were identified in the Middle East region, as indicated by the lack of current influenza sequences in the database from many countries in the region.