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Oxidative stress and pre-eclampsia
Published in Pankaj Desai, Pre-eclampsia, 2020
As is so well-known by now, all actions of ROS are not always pathological. There are many vital functions in the body based on the oxidative process. In the same way, all reducing systems are not necessarily health-promoting. Indeed in the vascular endothelium and ROS are disease-causing, and reducing systems are protective. On the other hand, many reductants also act as oxidizing agents at times. A classic example of this is water-soluble vitamin E analogue Trolox-C. It shows both reducing and oxidative properties in vitro.56 Such behaviours of some reductants have made clinicians cautious in recommending universal usage of reducing systems.
Basic Facts about Oxidative Stress, Inflammation, and the Immune System
Published in Kedar N. Prasad, Micronutrients in Health and Disease, 2019
To understand the role of free radicals and antioxidants in the human body, it is important to grasp the relationship between oxidation and reduction processes, which are constantly taking place in the body. Oxidation is a process in which an atom or molecule gains oxygen, loses hydrogen, or loses an electron. For example, carbon gains oxygen during oxidation and becomes carbon dioxide. A superoxide radical loses an electron during oxidation and becomes oxygen. Thus, an oxidizing agent is a molecule or atom that changes another chemical by adding oxygen to it or by removing electron or hydrogen from it. Examples of oxidizing agents are free radicals, ozone, and ionizing radiation.
Oxidation Numbers
Published in Patrick E. McMahon, Rosemary F. McMahon, Bohdan B. Khomtchouk, Survival Guide to General Chemistry, 2019
Patrick E. McMahon, Rosemary F. McMahon, Bohdan B. Khomtchouk
An oxidizing agent is a species that causes another atom to lose electrons; that is, to be oxidized. The oxidizing agent removes the electrons; therefore, the oxidizing agent is the atom (or corresponding molecule), which itself is reduced. In the reactions previously described, Cu was reduced and removed electrons from Zn; therefore, Cu was the oxidizing agent; oxygen was reduced and removed electrons from carbon; oxygen was the oxidizing agent.
New frontier radioiodinated probe based on in silico resveratrol repositioning for microtubules dynamic targeting
Published in International Journal of Radiation Biology, 2023
Ashgan F. Mahmoud, Mohamed H. Aboumanei, Walaa Hamada Abd-Allah, Mohamed M. Swidan, Tamer M. Sakr
In the radioiodination reactions, the adjustment of the reaction pH has great impact on the radioiodination yield as it highly affects the redox potential of the utilized oxidizing agent (Moustapha 2020). In this experimental study, the oxidizing agent (CAT) loosed some of its oxidizing power by raising the pH of the reaction mixture toward the alkaline medium. This may be justified by the CAT can be present in active forms (HOCl and H2OCl+) in acidic medium while the less reactive species (HOCl and ClO) appeared in alkaline one (Rashed et al. 2014). Figure 2(b) revealed that the potential pH which can achieve the maximum radioiodination yield (94.6 ± 1.66) is 5. At this pH, the maximum oxidizing power of CAT is attained which has the capability of oxidizing most of the iodine to iodonium (I+) facilitating the electrophilic substitution of H+ of the resveratrol ring by the iodonium (I+) (Mahmoud et al. 2020; Sanad 2021). By shifting the pH of the reaction mixture toward the highly acidic one, the radioiodination yield significantly reduced to be 77 ± 2.07 at pH 1. Furthermore, shifting the reaction pH toward the neutral and alkaline mediums lead to dwindling the radioiodination yield (87.2 ± 1.38 and 82 ± 1.03 at pH 7 and 9, respectively) that could be explained by the formation of undesirable oxidative forms of iodine (hypoiodite ion (IO−) and iodate (IO−3)) (Abdel-Ghany et al. 2013; Moustapha et al. 2013).
Cyanosis, hemolysis, decreased HbA1c and abnormal co-oximetry in a patient with hemoglobin M Saskatoon [HBB:c.190C > T p.His64Tyr]
Published in Hematology, 2021
Eva-Leonne Göttgens, Kristian Baks, Cornelis L. Harteveld, Kristel Goossens, Adriaan J. van Gammeren
In Hb M disease, treatment with both MB and ascorbic acid is ineffective because the ferric state in Hb M is stabilized. The Hb M structural variants are unstable or characterized by decreased oxygen affinities rather than other causes of methemoglobinemia, such as oxidative stress or enzymatic deficiency (CYB5R3). Treatment with MB would be undesirable, because as an oxidating agent, MB itself poses a risk of hemolytic anemia and could exacerbate methemoglobinemia. Exposure to any oxidizing agent should be avoided since these patients exhibit an increased risk of progression to symptomatic methemoglobinemia. Since there are no effective treatment options for patients with Hb M disease, counseling should focus on reassuring the patient about their benign condition and offering genetic testing to first-degree relatives.
Inactivation of Pseudomonas aeruginosa biofilms formed under high shear stress on various hydrophilic and hydrophobic surfaces by a continuous flow of ozonated water
Published in Biofouling, 2018
Evgenya S. Shelobolina, Diane K. Walker, Albert E. Parker, Dorian V. Lust, Johanna M. Schultz, Grace E. Dickerman
Ozone is a powerful oxidizing agent that has been studied for applications in the food industry (Khadre et al. 2001; Varga and Szigeti 2016) and in dentistry (Hems et al. 2005; Knight et al. 2008; Domb 2014) as a disinfectant. Lower concentrations that are suboptimal for biofilm inactivation (0.1–2 ppm) were examined in these studies. Food industry and dentistry-related research suggests that ozonated water can be used to control biofilms by preventing their formation (Knight et al. 2008), destroying the surrounding matrix, causing lysis of microorganisms within an established biofilm (Dosti et al. 2005; Robbins et al. 2005; Huth et al. 2009), and/or by destroying endotoxins and other compounds released upon microbial lysis (Rezaee et al. 2008).