Publications by authors named "Yassine H"

Article Synopsis
  • Norovirus (NoV) is a key cause of acute gastroenteritis in children worldwide, and a study in Qatar analyzed the prevalence, types, and clinical effects of NoV infections in young patients.
  • The research involved testing 177 fecal samples from children aged 3 months to 12 years, focusing on genotyping and analyzing demographic and clinical data over a two-year period.
  • Results showed higher infection rates in males and children aged 1-3 years, with most infections related to genogroup II strains, particularly genotype GII.4, peaking in summer months and indicating a significant link between NoV infections and severe clinical symptoms.
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Background: Sex may be an important modifier of brain health in response to risk factors. We compared brain structure and function of older overweight and obese women and men with type 2 diabetes mellitus.

Methods: Cross-sectional cognitive assessments and magnetic resonance images were obtained in 224 women and 95 men (mean age 69 years) with histories of type 2 diabetes mellitus and overweight or obesity.

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In the version of this article initially published, the labels (50 Å) above the scale bars in Fig. 1b were incorrect. The correct size is 50 nm.

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Background: Influenza surveillance is necessary for detection of emerging variants of epidemiologic and clinical significance. This study describes the epidemiology of influenza types A and B, and molecular characteristics of surface glycoproteins (hemagglutinin [HA] and neuraminidase [NA]) of influenza A subtypes: pH1N1 and H3N2 circulated in Arabian Gulf, Levant and North Africa regions during 2009-2017.

Methods: Analysis of phylogenetics and evolution of HA and NA genes was done using full HA and NA sequences (n = 1229) downloaded from Influenza Research Database (IRD).

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MicroRNA (miRNAs), a class of small, endogenous non-coding RNA molecules of about 21-24 nucleotides in length, have unraveled a new modulatory network of RNAs that form an additional level of posttranscriptional gene regulation by targeting messenger RNAs (mRNAs). These miRNAs possess the ability to regulate gene expression by modulating the stability of mRNAs, controlling their translation rates, and consequently regulating protein synthesis. Substantial experimental evidence established the involvement of miRNAs in most biological processes like growth, differentiation, development, and metabolism in mammals including humans.

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Infection with Middle East respiratory syndrome coronavirus (MERS-CoV) could be asymptomatic or cause mild influenza-like illness. Therefore, the prevalence of MERS-CoV infections in the general population could be underestimated, which necessitates active surveillance to determine the epidemiological importance of asymptomatic cases. The aim of this study is to evaluate the performance of various serological assays and to estimate the seroprevalence of anti-MERS-CoV antibodies in high- and low-risk groups in Qatar.

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Cerebral beta-amyloidosis (CA) is a condition in which amyloid-β (Aβ) proteins are deposited in the cerebral cortex and is a predictor of Alzheimer's disease (AD). The Aging Brain Study (ABS) investigated risk factors for CA in persons with diabetes and dyslipidemia. In the ABS, we identified that greater levels of LDL cholesterol and lower levels of HDL cholesterol were associated with increased CA.

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Helicobacter pylori (H. pylori) causes gastric mucosa inflammation and gastric cancer mostly via several virulence factors. Induction of proinflammatory pathways plays a crucial role in chronic inflammation, gastric carcinoma, and H.

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Influenza vaccines targeting the highly conserved stem of the hemagglutinin (HA) surface glycoprotein have the potential to protect against pandemic and drifted seasonal influenza viruses not covered by current vaccines. While HA stem-based immunogens derived from group 1 influenza A viruses have been shown to induce intragroup heterosubtypic protection, HA stem-specific antibody lineages originating from group 2 may be more likely to possess broad cross-group reactivity. We report the structure-guided development of mammalian-cell-expressed candidate vaccine immunogens based on influenza A virus group 2 H3 and H7 HA stem trimers displayed on self-assembling ferritin nanoparticles using an iterative, multipronged approach involving helix stabilization, loop optimization, disulfide bond addition, and side-chain repacking.

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The present vaccine against influenza virus has the inevitable risk of antigenic discordance between the vaccine and the circulating strains, which diminishes vaccine efficacy. This necessitates new approaches that provide broader protection against influenza. Here we designed a vaccine using the hypervariable receptor-binding domain (RBD) of viral hemagglutinin displayed on a nanoparticle (np) able to elicit antibody responses that neutralize H1N1 influenza viruses spanning over 90 years.

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Acute gastroenteritis remains a major cause of morbidity and mortality among young children worldwide. It accounts for approximately 1.34 million deaths annually in children younger than five years.

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The use of chitosan nanoparticles (ChNPs) in various biological and environmental applications is attracting great interest. However, potential side effects related to ChNP toxicity remain the major limitation hampering their wide application. For the first time, we investigate the potential organ-specific (cardiac, hepatic, and neuromuscular) toxicity of ChNPs (size 100⁻150 nm) using the zebrafish embryo model.

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Understanding immune responses to viral infections is crucial to progress in the quest for effective infection prevention and control. The host immunity involves various mechanisms to combat viral infections. Under certain circumstances, a viral infection or vaccination may result in a subverted immune system, which may lead to an exacerbated illness.

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The FOXO (Forkhead box O) transcription factors are implicated in several signaling pathways and play a vital role in various cellular and physiological processes include for instance, ROS (reactive oxygen species) response, cell proliferation, regulation of programmed cell death, longevity, metabolism and cancer and regulation of cell cycle. In humans, the four FOXO family members are responsible for resemblance in their structure, regulation and functions. FOXO1 gene is highly expressed in adipose tissues and it affects the regulation of glycogenolysis and gluconeogenesis through insulin signaling.

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Background: With the emergence of new influenza virus strains that are resistant to current inhibitors such as oseltamivir (anti-neuraminidase (NA)) and amantadine (anti-M2 proton channel), influenza A viruses continue to be a serious threat to the public health worldwide. With this in view, there is a persistent need for the development of broader and more effective vaccines and therapeutics. Identification of broadly neutralizing antibodies (bNAbs) that recognize relatively invariant structures ‎on influenza haemagglutinin (HA) stem has invigorated efforts to develop universal influenza vaccines.

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Background: The β-lactam antibiotics have traditionally been the main treatment of Enterobacteriaceae infections, nonetheless, the emergence of species producing β- Lactamases has rendered this class of antibiotics largely ineffective. There are no published data on etiology of urinary tract infections (UTI) and antimicrobial resistance profile of uropathogens among children in Qatar. The aim of this study is to determine the phenotypic and genotypic profiles of antimicrobial resistant Enterobacteriaceae among children with UTI in Qatar.

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The emergence of swine-origin pandemic H1N1 (pH1N1) in 2009 invigorated extensive surveillance programs worldwide which have resulted in the deposition of large numbers of H1N1 sequences to Genbank. In the present study, we report on global evolution and dynamics of the pandemic H1N1 influenza Hemagglutinin (HA) protein in viruses isolated from three different continents (North America, Europe and Asia) during the period between April 2009 until April 2017. Close to 2000 HA full protein sequences were downloaded from the Influenza Research Database of the NCBI and analyzed using DNAStar to run an alignment, the web-based NetNglyc to predict N-Glycosylation sites and finally, the BEAST software package to calculate evolution and substitution rates.

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Introduction: Although hepatitis E virus (HEV) is mainly transmitted via the faecal-oral route, the rate of HEV transmission via blood donation is on the rise. However, the seroprevalence of HEV among blood donors is not well established and is thought to be affected by the type of diagnostic assay used. We aimed to evaluate performance and correlation among widely used commercial diagnostic assays for the seroprevalence assessment of HEV-IgM/IgG among blood donors.

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Background: It is well documented that food handlers harbor and shed enteric foodborne pathogens causing foodborne disease outbreaks. However, little known on enteric antibiotic resistant (AR) bacteria carriage in food handlers. The objective of this study was to establish a baseline prevalence of fecal AR among food handlers in Qatar.

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Article Synopsis
  • The fusion (F) and attachment (G) proteins on RSV are key targets for neutralizing antibodies, and new research has identified promising antigenic sites that could enhance vaccine effectiveness.
  • Vaccination strategies are focusing on pregnant women in their third trimester to provide maternal antibodies, which can help protect infants who are particularly vulnerable to serious RSV infections.
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A better understanding of the seroprevalence and specificity of influenza HA stem-directed broadly neutralizing antibodies (bNAbs) in the human population could significantly inform influenza vaccine design efforts. Here, we utilized probes comprising headless, HA stabilized stem (SS) to determine the prevalence, binding and neutralization breadth of antibodies directed to HA stem-epitope in a cross-sectional analysis of the general population. Five group-1 HA SS probes, representing five subtypes, were chosen for this analyses.

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Antigen multimerization on a nanoparticle can result in improved neutralizing antibody responses. A platform that has been successfully used for displaying antigens from a number of different viruses is ferritin, a self-assembling protein nanoparticle that allows the attachment of multiple copies (24 monomers or 8 trimers) of a single antigen. Here, we design two-component ferritin variants that allow the attachment of two different antigens on a single particle in a defined ratio and geometric pattern.

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Antibiotic resistance (AR) is a growing public health concern worldwide, and it is a top health challenge in the 21st century. AR among Enterobacteriaceae is rapidly increasing, especially in third-generation cephalosporins and carbapenems. Further, strains carrying mobilized colistin resistance ( mcr) genes 1 and 2 have been isolated from humans, food-producing animals, and the environment.

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Background: The Epstein-Barr virus (EBV) is the causative agent of infectious mononucleosis. EBV is highly prevalent lymphotropic herpesvirus and has been linked to several malignancies. Transmission is generally by oral secretions, but can be through blood transfusions and organ transplantations.

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