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Blockchain Technology-Enabled Healthcare IoT to Increase Security and Privacy Using Fog Computing
Published in Sarvesh Tanwar, Sumit Badotra, Ajay Rana, Machine Learning, Blockchain, and Cyber Security in Smart Environments, 2023
S. Gunasekaran, S. Shanmugam, D. Palanivel Rajan, P. Rontala
Genetics [11] is the branch of science that is concerned with the structure and function of the genetic code. One percent of DNA is composed of genes that code for proteins; the remainder is non-coding DNA, sometimes known as junk DNA. In the non-coding DNA sequences, DNA sequences provide information for synthesizing particular types of RNA molecules (RNA is the chemical cousin of DNA). In the making of protein, specialized RNA molecules called transfer RNAs (tRNAs) and ribosomal RNAs (rRNAs) are created from non-coding DNA. These molecules help in the construction of amino-acid chains, which constitute a protein. Telomeres protect chromosomal ends from destruction during genetic material replication.
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Published in Michael Hehenberger, Zhi Xia, Huanming Yang, Our Animal Connection, 2020
Michael Hehenberger, Zhi Xia, Huanming Yang
In 2009, the Nobel Prize in physiology or medicine was awarded jointly to Elizabeth H. Blackburn, Carol W. Greider, and Jack W. Szostak, for the discovery of “how chromosomes are protected by telomeres and the enzyme telomerase.”116 They discovered how the chromosomes can be copied in a complete way during cell divisions and how they are protected against degradation by means of telomeres (the ends of the chromosomes) and by the enzyme that forms them: telomerase. If the telomeres are shortened, cells age. Conversely, if telomerase activity is high, telomere length is maintained, and cellular death is delayed. This is the case in cancer cells, which can be considered to have “eternal life.” Although involving chromosomes, the model organisms used were mostly yeast and C. elegans, rather than the fruit fly.
Cell Biology for Bioprocessing
Published in Wei-Shou Hu, Cell Culture Bioprocess Engineering, 2020
Cells that are subject to senescence thus appear to “count” their number of doublings. Senescence is regulated by cellular events and is often thought to be related to aging. It is essentially a growth arrest, but one that differs from the quiescent state. Cells in a quiescent state can revert to their growth phase, but cells entering senescence undergo an irreversible growth arrest. Senescence may also occur in response to stress or overexpression of oncogene, or be induced by telomere shortening. Telomeres are special repetitive sequences at the end of chromosomes. They are not replicated by DNA polymerase during DNA replication but are synthesized by telomerase. The DNA polymerase reaction does not accurately reproduce the number of tandem repeats of the telomeres. There is thus much variation in telomere length among cells. As the number of passages increases, telomeres become shorter unless they are repaired by telomerase. For instance, in embryonic stem cells, telomerase activity is high in order to maintain the telomere length. Unlike cell strains, embryonic stem cells do not exhibit senescence.
Association of Genetic Polymorphisms of TERT with Telomere Length in Coke Oven Emissions-Exposed Workers
Published in International Journal of Environmental Health Research, 2022
Mengqing Yan, Shuai Cheng, Sihua Wang, Xiaoran Duan, Acquaye Reuben Mensah, Lei Li, Yuhong Zhang, Guoyu Li, Junfeng Zhao, Feifei Feng, Xiaoshan Zhou, Yongjun Wu, Yongli Yang, Wei Wang
Coke oven emissions (COE) contain volatile organic solvents and various particles, particularly polycyclic aromatic hydrocarbons (PAHs), which are highly toxic (Xin et al. 2014). Long-term exposure to PAHs induces oxidative stress, DNA damage, and chromosomal aberrations (Orjuela et al. 2010; Moorthy et al. 2015). Telomeres are non-coding DNA sequences composed of 5'-TTAGGG-3’ tandem repeats at the end of eukaryotic chromosomes. They are commonly associated with chromosome stability. Telomere shortening is associated with aging, and current studies suggest an important role of telomere structure, telomeric DNA damage, and telomere end-capping proteins during aging and in various age-associated disorders. A study involving 1628 coke-oven workers revealed that exposure to high PAHs levels accelerates shortening of the telomere length(Fu et al. 2018). Previous studies have also reported that shorter telomere lengths are associated with occupational exposure to COEs. In the same line, there exists an exposure-response relationship between COEs exposure and telomere damage(Wang et al. 2019). Nonetheless, changes in telomere length are primarily caused by a combined genetic and environmental effect.
Telomere length and urinary 8-hydroxy-2’-deoxyguanosine and essential trace element concentrations in female Japanese university students
Published in Journal of Environmental Science and Health, Part A, 2021
Yuki Mizuno, Shoko Konishi, Hideki Imai, Eiji Fujimori, Nobuhiko Kojima, Chiaki Kajiwara, Jun Yoshinaga
The telomere length of chromosomes in a cell is considered a biomarker of cellular aging.[1] Telomere sequences comprise highly repetitive nucleotides [5′-(TTAGGG)n-3′ in humans] and are located at the ends of chromosomes. Telomeres act as caps for chromosomes to prevent end-to-end fusion and preserve their integrity. Hence, they are thought to contribute to genomic stability.[2] Telomere length progressively shortens after each cell division because the ends of DNA sequences cannot be replicated entirely by DNA polymerase, and telomerase (the specific enzyme that extends telomeres) is inactivated in most somatic cells (the end-replication problem).[3,4] When the telomere length is critically shortened to a certain point, the cell enters senescence.[3]
Walking and biologic ageing: Evidence based on NHANES telomere data
Published in Journal of Sports Sciences, 2020
Since the length of telomeres is a marker of biological ageing, the association between telomere length and chronological age is considerable. Beyond chronological age, other factors account for shorter telomeres and increased cell ageing in adults, including low socioeconomic levels (Needham et al., 2013), smoking (Huzen et al., 2014), obesity (Mundstock, Sarria et al., 2015), caffeine consumption (Tucker, 2017b), type 2 diabetes (Tamura et al., 2016; Zhao et al., 2013), and diet (Cassidy et al., 2010; Crous-Bou et al., 2014; Rafie et al., 2017). Research also indicates that total physical activity is directly related to telomere length (Mundstock, Zatti et al., 2015). As physical activity levels increase, biologic ageing is curtailed. However, there is not a consensus. Some studies have found there is no relationship between physical activity and telomere length (Mundstock, Zatti et al., 2015).