A5047235283- Selenium in Biological Systems
- Trace Elements in Health
- RNA modifications and cancer
- Pesticide Exposure and Toxicity
- Electromagnetic Fields and Biological Effects
- Pluripotent Stem Cells Research
- Redox biology and oxidative stress
- Metalloenzymes and iron-sulfur proteins
- Heavy Metal Exposure and Toxicity
- Environmental Toxicology and Ecotoxicology
- Organ and Tissue Transplantation Research
- Irrigation Practices and Water Management
- Birth, Development, and Health
- Reproductive System and Pregnancy
- Air Quality and Health Impacts
- Prenatal Screening and Diagnostics
- Magnesium in Health and Disease
- RNA and protein synthesis mechanisms
- Enterobacteriaceae and Cronobacter Research
- Water resources management and optimization
- Retinopathy of Prematurity Studies
- Fullerene Chemistry and Applications
- Mercury impact and mitigation studies
- Molecular Communication and Nanonetworks
- Alcoholism and Thiamine Deficiency
Alexandria University
2004-2021
Beirut Arab University
2010-2019
National Institutes of Health
1998-2013
National Cancer Institute
1998-2013
Agricultural Genetic Engineering Research Institute
2013
Center for Cancer Research
2009
University of California, San Diego
2004-2007
University of Newcastle Australia
2006
Moores Cancer Center
2004
Thioredoxin reductases (TRs) are important redox regulatory enzymes, which control the state of thioredoxins. Mammals have cytosolic and mitochondrial TRs, contain an essential selenocysteine residue reduce In addition, thioredoxin/glutathione reductase (TGR) was identified, is a fusion N-terminal glutaredoxin domain TR module. Here we show that TGR expressed at low levels in various tissues but accumulates testes after puberty. The protein particularly abundant elongating spermatids site...
A common posttranscriptional modification of tRNA is the isopentenylation adenosine at position 37, creating isopentenyladenosine (i<sup>6</sup>A). The role this modified nucleoside in protein synthesis higher eukaryotes not well understood. Selenocysteyl (Sec) (tRNA<sup>[Ser]Sec</sup>) decodes specific UGA codons and contains i<sup>6</sup>A. To address tRNA, we constructed a site-specific mutation, which eliminates site isopentenylation, <i>Xenopus</i> tRNA<sup>[Ser]Sec</sup> gene....
Selenium has been implicated in cancer prevention, but the mechanism and possible involvement of selenoproteins this process are not understood. To elucidate whether 15-kDa selenoprotein may play a role etiology, complete sequence human protein gene was determined, various characteristics associated with expression were examined normal malignant cells tissues. The 51-kilobase pair for consisted five exons four introns localized on chromosome 1p31, genetic locus commonly mutated or deleted...
Selenocysteine (Sec) tRNA (tRNA([Ser]Sec)) serves as both the site of Sec biosynthesis and adapter molecule for donation this amino acid to protein. The consequences on selenoprotein overexpressing either wild type or a mutant tRNA([Ser]Sec) lacking modified base, isopentenyladenosine, in its anticodon loop were examined by introducing multiple copies corresponding genes into mouse genome. Overexpression wild-type did not affect synthesis. In contrast, levels numerous selenoproteins...
Methionine residues are susceptible to oxidation, but this damage may be reversed by methionine sulfoxide reductases MsrA and MsrB. Mammals contain one three MsrBs, including a selenoprotein MsrB1. Here, we show that MsrB1 is the major reductase in liver of mice it among proteins most easily regulated dietary selenium. MsrB1, not activities, were reduced with age, selenium regulation was preserved aging liver, suggesting could account for impaired reduction animals. We also examined Msr...
Changes in dietary selenium and selenoprotein status may influence both anti- pro-cancer pathways, making the outcome of interventions different from one study to another. To characterize such outcomes a defined setting, we undertook controlled hepatocarcinogenesis involving varying levels altered using mice carrying mutant (A37G) selenocysteine tRNA transgene (TrsptG37) and/or cancer driver TGFα transgene. The use TrsptG37 expression tissue specific manner and, at sufficient levels,...
This study investigated the non-thermal effects of Wi-Fi radiofrequency radiation 2.4 GHz on global gene expression in Escherichia coli K-12 DH5α. High-throughput RNA-sequencing exposed and non-exposed bacteria revealed that 101 genes were differentially expressed (DEGs) at P ≤ 0.05. The up-regulated 52 while down-regulated ones 49. QRT-PCR analysis pgaD, fliC, cheY, malP, malZ, motB, alsC, alsK, appB appX confirmed RNA-seq results. About 7% DEGs are involved cellular component organization,...
Investigate the effect of dietary exposure to chlorpyrifos on locomotion and contraction soleus andextensor digitorum longus (edl) involved in locomotion. Methods: Rats were fed diets containing 1 or 5 mg kg-1 for six weeks. Locomotion has been assessed weekly using beam walking balance tests. Soleus edl removed study contractile properties, myofibrillar protein content myosin heavy chain isoforms.Animals treated with had a decrease body weight. An increase by 28% 24% latency time test 9%...
The radiation emitted from electromagnetic fields (EMF) can cause biological effects on prokaryotic and eukaryotic cells, including non-thermal effects.The present study evaluated the of wireless fidelity (Wi-Fi) operating at 2.4 GHz part non-ionizing EMF different pathogenic bacterial strains (Escherichia coli 0157H7, Staphylococcus aureus, epidermis). Antibiotic resistance, motility, metabolic activity biofilm formation were examined.In this case-control, a Wi-Fi router was used as source...
The selenocysteine (Sec) tRNA population inDrosophila melanogaster is aminoacylated with serine, forms selenocysteyl-tRNA, and decodes UGA. K m of Sec serine for seryl-tRNA synthetase 6.67 9.45 nm, respectively. Two major bands were resolved by gel electrophoresis. Both tRNAs sequenced, their primary structures indistinguishable colinear that the corresponding single copy gene. They are 90 nucleotides in length contain three modified nucleosides, 5-methylcarboxymethyluridine,N...
Selenocysteine insertion during selenoprotein biosynthesis begins with the aminoacylation of selenocysteine tRNA[Ser]Sec serine, conversion serine moiety to selenocysteine, and recognition specific UGA codons within mRNA. exists as two major forms, differing by methylation ribose portion nucleotide at wobble position anticodon. The levels relative distribution these forms tRNA are influenced selenium in mammalian cells tissues. We have generated Chinese hamster ovary that exhibit increased...
Clinical application of in utero transplantation (IUT) human fetuses with intact immune systems resulted a very low level donor chimerism. In this study, we examined whether the fetal system early second trimester pregnancy (13.5 dpc) can initiate tolerance for major histocompatibility complex (MHC)-mismatched embryonic stem (ES) cells. We also mechanisms respond differently to ontogenetically different cells.MHC-mismatched ES, liver (FL), and bone-marrow (BM) cells (H-2kd) at 1 x 10(9)...
This study investigated the effects of exposure diabetic rats to electromagnetic radiation (EMR) 900 MHz from cell phone base stations antenna for four weeks on plasma triglycerides and cholesterol. We also examined whether selenium administration into these affects levels parameters. Our results showed that this EMR increased triglycerides, total cholesterol VLDL-c. The daily intraperitoneally injection 2.0 µg selenium/kg body weight as sodium selenite decreased VLDL-c compared with...