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Cellular and Immunobiology
Published in Karl H. Pang, Nadir I. Osman, James W.F. Catto, Christopher R. Chapple, Basic Urological Sciences, 2021
Masood Moghul, Sarah McClelland, Prabhakar Rajan
Both are nucleic acids made from organic molecules called nucleotides, consisting of:A nitrogenous base (thymine or uracil in RNA, cytosine, adenine, guanine).A 5-carbon sugar (ribose or deoxyribose).One or more phosphate groups (acid).
Genetics
Published in Cathy Laver-Bradbury, Margaret J.J. Thompson, Christopher Gale, Christine M. Hooper, Child and Adolescent Mental Health, 2021
Deoxyribonucleic acid (DNA) is located in the nucleus and mitochondria of the cell. It consists of a sugar-phosphate backbone and four different types of nitrogenous base: adenine, cytosine, thymine and guanine. Each base partner with a complementary base to form base pairs. The DNA molecule itself forms a double helix structure, which is tightly coiled. Nuclear DNA contains approximately 21,000 genes in humans and has been more extensively studied than mitochondrial DNA.
Antiviral Agents and Rational Drug Design
Published in Nathan Keighley, Miraculous Medicines and the Chemistry of Drug Design, 2020
Nucleic acids are polymers composed of nucleotide monomers; these building blocks of DNA and RNA are composed of a nitrogenous base (purines or pyrimidines) attached to a sugar molecule and a phosphate group, which make up the backbone of the nucleic acid. The sugar molecule bonded to a base can be referred to separately as a nucleoside.
The Role of Inflammatory Cytokines in Neovascularization of Chemical Ocular Injury
Published in Ocular Immunology and Inflammation, 2022
Alireza Shahriary, Milad Sabzevari, Khosrow Jadidi, Farshad Yazdani, Hossein Aghamollaei
Sulfur mustard is a vesicant agent that severely affects living tissues such as eyes, skin, and lung. The eyes due to humid surface environment are susceptible tissue to mustard gas damages a few hours after exposure.23 More than 100,000 Iranians were wounded by the use of SM during the Iran-Iraq war (1980–1988). Sadly, there are currently around 35,000 victims suffering from chronic symptoms of SM. 75% to 90% of exposed people are suffering from acute ocular injury, and some cases will burden the chronic phase.24 The early ocular complications of mustard gas include photophobia, burning pain, swelling of the eyelids and excessive lacrimation; however, limbal ischemia, visual impairments, and corneal neovascularization are the most characteristics of patients in chronic phase.25 Mustard gas, which is in the form of a small oily aerosol, has a toxicity ability to disrupt cell functions. Mustard is able to alkylate nitrogenous bases in the DNA and protein molecules. In consistent with abruption in DNA and protein synthesis, the cell cycle in the G2-M phase is arrested leading to a reduction in repairing and healing systems.26 Furthermore, the mustard dramatically depletes the compound of intracellular glutathione (GSH) using ROS production and H2O2 in particular. The accumulation of ROS in cells causes a massive oxidative stress in the anterior segment of the eyes. It increases inflammation of the corneal surface as the pathophysiologic basis of dry eye as well as the presence of CNV.27,28
Chromosome aberration in typical biological systems under exposure to low- and high-intensity magnetic fields
Published in Electromagnetic Biology and Medicine, 2020
Emanuele Calabrò, Hit Kishore Goswami, Salvatore Magazù
Chromosomes are molecules composed of the deoxyribonucleic acid (DNA) that represents the genetic material of a living being. In human beings, there are 22 pairs of chromosomes and 2 sex chromosomes for a total of 46. DNA is an organic polymer composed of monomers that are called nucleotides. They consist of a phosphate group and a nitrogenous base linked to deoxyribose by the so-called N-glycoside bond. The nitrogenous bases that can be used in nucleotide formation are adenine, cytosine, guanine and thymine disposed in base pairs of adenine-thymine (A-T) and guanine-cytosine (G-C) that in aqueous solutions are linked one each other by hydrogen bonds forming a double helix structure because of the repulsions between the negative charge of phosphate groups. This double helix structure is bound to proteins (the histones) that have positively charged amino acids in order to bind the DNA which is negatively charged and is wrapped around the core of histone of eight protein subunits forming the nucleosome. About 200 base pairs of DNA are coiled around each histone. This coil is untwisted generating a negative superturn per nucleosome that is the active chromatin.
Molecular structure investigation towards pharmacodynamic activity and QSAR analysis on hypoxanthine using experimental and computational tools
Published in Egyptian Journal of Basic and Applied Sciences, 2018
G. Susithra, S. Ramalingam, S. Periandy, R. Aarthi
The Hypoxanthine is normally belongs to heterocycles family which peculiarly contains pyrimidine and imidazole rings. Hypoxanthine is a purine derivative with nitrogenous base rarely found as a constituent nucleic acid [1]. Heterocycles showing in their strange structures where the pyrimidine ring is fused to azolic moieties, are interesting systems being with important biochemical, pharmacological and physicochemical property [2,3] . During the recent decades numerous pyrimidine derivatives have found to have wide clinical and pharmacological applications [4]. Particularly, fused pyrimidine with Imidazole ring persists to attract considerable attention since their great practical usefulness, primarily due to very wide spectrum of biological activities [5,6] . The hypoxanthine naturally has different Tautomerism which resolves the specific prototype of hydrogen bond donors and acceptors present in a specific molecule. Similarly, the fused imidazole and its derivatives are generally having bioactivity against inflammatory mediators [7].