Publications by authors named "Yasser E Shahein"

Article Synopsis
  • - The study focuses on Hyalomma dromedarii ticks, which are significant for transmitting pathogens to large animals in Egypt, especially as camels and cattle are imported from neighboring countries.
  • - Researchers analyzed the transcriptome of these ticks by examining mixed mRNAs from various life stages (eggs, larvae, nymphs, and both fed and unfed adults) to understand the biochemical interactions that take place during tick feeding.
  • - The results included a comparison of identified sequences with databases to identify potential protein functions and properties, setting the stage for further understanding of tick physiology and its implications for disease transmission in livestock.
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Article Synopsis
  • Piroplasmosis and anaplasmosis are diseases caused by protozoa and bacteria transmitted by ticks, specifically the Hyalomma dromedarii species found on camels in Egypt.
  • A study investigated the presence of these pathogens in H. dromedarii ticks over four seasons, collecting samples from a slaughterhouse between June 2021 and April 2022.
  • Results showed that 13.8% of the ticks had piroplasms (mostly Babesia bigemina) and 20.7% had Anaplasmataceae (Anaplasma marginale), with a higher detection rate for piroplasms in spring and Anaplasmataceae in summer.
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Article Synopsis
  • Monoclonal IgY antibodies are gaining popularity due to their high specificity and scalability, making them a strong alternative to traditional polyclonal IgY antibodies.
  • The text outlines the production and purification methods of monoclonal IgY antibodies, emphasizing their advantages, such as superior reliability and cost-effectiveness, especially in low- and middle-income countries.
  • It concludes by noting the significant benefits of monoclonal IgY antibodies for diagnostics, therapeutics, and research, while also addressing future challenges in the field.
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Ticks have harmful impacts on both human and animal health and cause considerable economic losses. Leucine aminopeptidase enzymes (LAP) play important roles during tick infestation to liberate vital amino acids necessary for growth. The aim of the current study is to identify, express and characterize the LAP from the hard tick Hyalomma dromedarii and elucidate its biochemical characteristics.

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Hepatocellular carcinoma and bacterial resistance are major health burdens nowadays. Thus, providing new therapies that overcome that resistance is of great interest, particularly those derived from nature rather than chemotherapeutics to avoid cytotoxicity on normal cells. Venomous animals are among the natural sources that assisted in the discovery of novel therapeutic regimens.

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Escherichia coli cell envelope is crucial for stress sensing and signal transduction, mediated by numerous protein-protein interactions to enable adaptation and survival. Interfering with these interactions might affect envelope integrity leading to bacterial death. The outer membrane lipoprotein (RcsF) is the stress sensor of the regulator of capsule synthesis (Rcs) phosphorelay that senses envelope threats.

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The incidence of hepatocellular carcinoma (HCC) and HCC-related deaths has increased over the last few decades. There are several risk factors of HCC such as viral hepatitis (B, C), cirrhosis, tobacco and alcohol use, aflatoxin-contaminated food, pesticides, diabetes, obesity, nonalcoholic fatty liver disease (NAFLD), and metabolic and genetic diseases. Diagnosis of HCC is based on different methods such as imaging ultrasonography (US), multiphasic enhanced computed tomography (CT), magnetic resonance imaging (MRI), and several diagnostic biomarkers.

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The new coronavirus (SARS-CoV-2) is a respiratory virus causing coronavirus disease (COVID-19). Individuals with COVID-19 can shed the viral genome in their feces, even if they do not have symptoms, and the virus can be detected in wastewater. The current study provides the first surveillance of SARS-CoV-2 RNA genome in the wastewater in Egypt.

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Viral infections are linked to a variety of human diseases. Despite the achievements made in drug and vaccine development, several viruses still lack preventive vaccines and efficient antiviral compounds. Thus, developing novel antiviral agents is of great concern, particularly the natural products that are promising candidates for such discoveries.

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Background: The recently emerged SARS-CoV-2 caused a global pandemic since the last two years. The urgent need to control the spread of the virus and rapid application of the suitable health measures raised the importance of available, rapid, and accurate diagnostic approaches.

Objective: The purpose of this study is to describe a rapid in-house optimized ELISA based on the expression of the receptor binding domain (RBD) of the SARS-CoV-2 spike protein in a prokaryotic system.

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A new matrix formulation was devised for catalase immobilization. Carrageenan-alginate beads different ratios were developed and soaked into different ratios of CaCl-KCl as a hardening solution. The best formulation for loading capacity was selected, treated with polyethylene imine followed by glutaraldehyde and further studied.

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The harmful COVID-19 pandemic caused by the SARS-CoV-2 coronavirus imposes the scientific community to develop or find conventional curative drugs, protective vaccines, or passive immune strategies rapidly and efficiently. Passive immunity is based on recovering hyper-immune plasma from convalescent patients, or monoclonal antibodies with elevated titer of neutralizing antibodies with high antiviral activity, that have potential for both treatment and prevention. In this review, we focused on researching the potentiality of monoclonal antibodies for the prevention and treatment of COVID-19 infection.

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Protein misfolding and aggregation lead to amyloid generation that in turn may induce cell membrane disruption and leads to cell apoptosis. In an effort to prevent or treat amyloidogenesis, large number of studies has been paying attention on breakthrough of amyloid inhibitors. In the present work, we aim to access the effect of two drugs, that is, acetylsalicylic acid and 5-amino salicylic acid on insulin amyloids by using various biophysical, imaging, cell viability assay, and computational approaches.

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The aggregation phenomenon (amyloid and amorphous) is associated with several pathological complications in human, such as Alzheimer's, Parkinson's, Huntington, Cataract diseases, and Diabetes mellitus type 2. In the present study we are offering evidence and breaking the general belief with regard to the polyphenols action as protein aggregate inhibitors. Herein we confirm that tannic acid (TA) is not only an amyloid inducer, but also it switches one type of conformation, ultimately morphology, into another.

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The binding interaction between clofarabine, an important anticancer drug and two important carrier proteins found abundantly in human plasma, Human Serum Albumin (HSA) and α-1 acid glycoprotein (AAG) was investigated by spectroscopic and molecular modeling methods. The results obtained from fluorescence quenching experiments demonstrated that the fluorescence intensity of HSA and AAG is quenched by clofarabine and the static mode of fluorescence quenching is operative. UV-vis spectroscopy deciphered the formation of ground state complex between anticancer drug and the two studied proteins.

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Protein misfolding and aggregation are associated with more than twenty diseases, such as neurodegenerative diseases. The amyloid oligomers and fibrils may induce cell membrane disruption and lead to cell apoptosis. A great number of studies have focused on discovery of amyloid inhibitors which may prevent or treat amyloidosis.

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Isoprenaline hydrochloride is a potential cardiovascular drug helps in the smooth functioning of the heart muscles. So, we have performed the binding study of ISO with BSA. This study was investigated by UV absorption, fluorescence, synchronous fluorescence, circular dichroism, etc.

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Protein and peptide aggregation raises keen interest due to their involvement in number of pathological conditions ranging from neurodegenerative disorders to systemic amyloidosis. Here, we have reviewed recent advances in mechanisms of aggregation, emerging technologies towards exploration, characterization of aggregate structures, detection at molecular level and the strategies to combat the phenomenon of aggregation both in cellular and in vitro conditions. In consistence, we have illustrated almost all factors that influence the protein aggregation both in vitro and in vivo environments.

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Studying amyloid associated neurodegenerative diseases is an active area of research. Cure for these diseases are still to be discovered. In the present study we have performed comprehensive biophysical and computational experiments showing levodopa not only significantly inhibits heat induced fibrillization of human serum albumin but also disaggregates preformed fibrils.

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A serine metallokeratinase enzyme (30 kDa) produced by a newly isolated Bacillus strain (Bacillus pumilus NRC21) cultivated under optimized conditions in medium containing chicken feather meal was purified and characterized in a set of biochemical assays. The purification was carried out using two successive chromatographic steps; cation exchange chromatography on CM-cellulose and gel filtration on sephadex G-100 columns. The purified enzyme showed a specific activity of 2000 units/mg protein against 170 units/mg protein for crude extract with 12 fold purification.

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Rhipicephalus (Boophilus) annulatus is a bloodsucking ectoparasite that causes severe production losses in the cattle industry. This study aims to evaluate the in vitro effects of tannic acid, hematin (GST inhibitors) and different plant extracts (rich in tannic acid) on the activity of the recombinant glutathione S-transferase enzyme of the Egyptian cattle tick R. annulatus (rRaGST), in order to confirm their ability to inhibit the parasitic essential detoxification enzyme glutathione S-transferase.

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Infestation of cattle by ticks of Rhipicephalus spp. results in severe veterinary and economical losses. Identification of novel proteins from tick salivary glands will enhance our understanding of several aspects of tick physiology and will aid in the development of anti-tick vaccines.

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Background: Curcumin is a yellow-pigment phenolic compound used as a food spice and has a broad spectrum of antioxidant, anti-carcinogenic, anti-mutagenic and anti-inflammatory properties.

Methods: Radio-protective efficacy of curcumin; diferuloylmethane (C21H20O6) was evaluated using molecular and biochemical assays in male mice after exposure to 3 Gy γ-rays. Curcumin was given at a dose of 400 μmol/ kg body weight via gastric tubes for 5 following days either pre-, post- or both pre- and post-exposure.

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The control of Rhipicephalus annulatus ticks in Egypt and other countries relies principally on the application of acaricides which have many drawbacks. Recently, cattle vaccination against ticks showed a potential unconventional approach to control ticks. As a target, salivary glands contain various proteins that may play specific roles during attachment, feeding and may modulate the immune system of the host.

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The middle capsid protein of rotavirus, VP6, constitutes approximately 51% of the virion by weight. The high degree of identity (>87-99%) in the primary amino acid sequences of VP6 proteins from mammalian rotaviruses suggests VP6-based vaccines could potentially provide heterotypic protection. For this reason, significant effort has been directed toward producing recombinant rotavirus VP6 vaccines.

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