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Toxic Responses of the Liver
Published in Stephen K. Hall, Joana Chakraborty, Randall J. Ruch, Chemical Exposure and Toxic Responses, 2020
Cholestasis is defined as a reduction of bile formation or impaired secretion of specific bile components. It is not necessarily associated with hepatocyte death, but may be the result of hepatocellular injury or death. Cholestasis can also occur following injury to bile duct cells or blockage of bile ducts. Several toxic agents can induce cholestasis through these mechanisms. Methylene dianiline is one agent that injures bile duct cells and causes cholestasis. Associated with cholestasis is a phenomenon known as jaundice in which the skin and eyes of the affected individual appear yellowish due to the accumulation of bilirubin. Normally the liver degrades hemoglobin, the oxygen-carrying pigment of red blood cells, to a yellowish compound called bilirubin which is excreted with the bile. When bile secretion or flow is reduced, bilirubin accumulates in blood and tissues such as the skin.
Nitrate Levels in Drinking Water and Methemoglobin in Infants
Published in John R. Goldsmith, Environmental Epidemiology: Epidemiological Investigation of Community Environmental Health Problems, 2019
Hemoglobin is the red-colored pigment of the blood which binds molecules of oxygen and allows the blood to perform its vital function of transporting oxygen to the tissues of the body. In each hemoglobin molecule there is an iron atom in the ferrous or divalent state. The oxygen molecules carried by the hemoglobin are adsorbed and do not react with this iron atom directly. If the iron atom is oxidized to the ferric (trivalent) state, the hemoglobin changes color to brown and loses its capability to carry oxygen. This brown-colored derivative of hemoglobin is called met-hemoglobin, and to a very slight extent this occurs naturally and spontaneously. In normal persons there exists an enzyme, called methemoglobin reductase, because it reduces the iron to its ferrous state and returns the hemoglobin molecule to normal, transforming brown-colored inactive methemoglobin to red-colored active hemoglobin again. In infants during the early months of life this enzyme has not yet become active and efficient, so any methemoglobin formed tends to remain in the blood cells.
Toxicology
Published in Martin B., S.Z., of Industrial Hygiene, 2018
Cholestasis is a reduction of bile formation or impaired secretion of specific bile components. It is not necessarily associated with hepatocyte death, but may be the result of hepatocellular injury or death. Cholestasis can also occur following injury to bile duct cells or blockage of bile ducts. A number of toxic agents can induce cholestasis through these mechanisms. Methylene dianiline is one agent that injures bile duct cells and causes cholestasis. Associated with cholestasis is a phenomenon known as jaundice in which the skin and eyes of the affected individual appear yellowish due to the accumulation of bilirubin. Normally, the liver degrades hemoglobin, the oxygen-carrying pigment of red blood cells, to a yellowish compound called bilirubin which is excreted with the bile. When the secretion or flow is reduced, bilirubin accumulates in blood and tissues, resulting in jaundice.
Non-invasive and non-contact automatic jaundice detection of infants based on random forest
Published in Computer Methods in Biomechanics and Biomedical Engineering: Imaging & Visualization, 2023
Fatema-Tuz-Zohra Khanam, Ali Al-Naji, Asanka G. Perera, Danyi Wang, Javaan Chahl
Jaundice or hyperbilirubinemia is defined as the yellow discoloration of the skin and sclera of the eyes due to an excess level of bilirubin (Dzulkifli et al. 2018). Generally, jaundice is noticeable when serum bilirubin level exceeds 2.0 mg/dl in the blood (Puppalwar 2012). Bilirubin is a water-soluble tetrapyrrolic yellowish pigment that is present in the blood and whose excess accumulation in the skin results in neonatal jaundice symptoms (Ansong-Assoku and Ankola 2018). Bilirubin is created due to the breakdown of old red blood cells. In the human body, new red blood cells are produced, and old ones are broken down continuously. In an adult, the red blood cells survive for about 120 days; however, in a newborn infant, they survive for a significantly shorter time. Hence, newborns have higher than average quantities of red blood cells, which leads to excess bilirubin level due to the breakdown of more red blood cells (Ansong-Assoku and Ankola 2018). Normally, the damaged blood cells that produce bilirubin are metabolised by the liver for excretion. Later, bilirubin is secreted through urine and bile (Chee et al. 2018). Short-term excess of bilirubin is mostly harmless and self-limiting. But a high level of bilirubin in newborn infants is neurotoxic and can permanently damage the brain, which is called kernicterus. It may cause cerebral palsy, deafness or hearing loss, language difficulties, and developmental delay or can be fatal in the worst cases (Ullah et al. 2016; Chee et al. 2018).
Study on the wall-breaking method of carotenoids producing yeast Sporidiobolus pararoseus and the antioxidant effect of four carotenoids on SK-HEP-1 cells
Published in Preparative Biochemistry and Biotechnology, 2019
Chang Liu, Yuliang Cheng, Chao Du, Tianqi Lv, Yahui Guo, Mei Han, Fuwei Pi, Weiguo Zhang, He Qian
Carotenoids are a class of natural pigments, which range from their original evolutionary role as light-quenching pigments to antioxidants, precursors of vitamin A, colorants and possible tumor-inhibitors for the food, pharmaceutical, and chemical industries.[1] Animals are unable to synthesize carotenoids directly by themselves and must obtain them from the diets.[2] Compared with extracting carotenoid pigments from plants and vegetables, the microbial production of carotenoids can offset problems of seasonal and geographic variability, and is a more suitable choice for industrial applications because of the economic advantages of microbial processes using natural low-cost substrates as carbohydrate sources.[3] The strains currently used for producing carotenoids mainly include yeasts of the genera Sporidiobolus, Rhodotorula, Rhodosporidium, Sporobolomyces, and Phaffia.[3,4]
Iron balance and iron supplementation for the female athlete: A practical approach
Published in European Journal of Sport Science, 2018
Charles R Pedlar, Carlo Brugnara, Georgie Bruinvels, Richard Burden
Haemoglobin, carried in the red blood cell, is a globular protein pigment molecule containing a non-protein haem group in its centre, carrying the iron ion at the site of oxygen binding. Haemoglobin is carried in red blood cells which are produced and cleared at a rate of approximately 2 million per second (Higgins, 2015), thus total haemoglobin mass (tHb-mass), a primary determinant of maximal oxygen uptake (O2max) (Schmidt & Prommer, 2010), is fundamentally reliant upon adequate iron stores. Iron is also a requisite component of cytochromes and enzymes involved in electron transport within the mitochondria. A reduction in iron stores may therefore impact upon the capacity for both oxygen transport and utilisation, lead to fatigue, or cause under-performance. Further, since iron is essential for brain development and cognitive performance (Murray-Kolb & Beard, 2007), iron deficiency could affect motivation, concentration and decision-making, also impacting upon exercise performance.