Cellular damage

The production of free radicals (ROS) is an unavoidable consequence of life in an aerobic environment. Free radicals produced from the metabolic activities of oxygen attack biological membranes and lipoproteins via oxidation in a process called lipid perioxidation. This attack damages cells and lipids often in a chain reaction with carbon-based molecules such as polyunsaturated fatty acids (PUFA) in a reaction with molecular oxygen. This creates oxidative stress and damage to tissues. Free radicals also damage chromosomal DNA.

272p mnemosyne75 02-02-2013 31 9   Download

One of the least recognized causes of cellular damage duringex vivopreser-vation of red blood cells is oxidative injury to the hemoglobin. The latter has been associated with hemolysis through the release of toxic substances and oxidation of vital cell components.

11p mobifone23 18-01-2013 10 2   Download

Oxidant-induced cell damage may be initiated by peroxidative injury to lysosomal membranes, catalyzed by intralysosomal low mass iron that appears to comprise a major part of cellular redox-active iron. Resulting relocation of lytic enzymes and low mass iron would result in secondary harm to various cellular constituents.

12p inspiron33 25-03-2013 17 2   Download

Over the last three decades, knowledge on the molecular biology of human cancers has vastly expanded. A host of genes and proteins involved in cancer development and progression have been defined and many mechanisms at the molecular, cellular and even tissue level have been, at least partly, elucidated. Insights have also been gained into the molecular mechanisms underlying carcinogenesis by chemical, physical, and biological agents and into inherited susceptibility to cancer. Accordingly, Part I of the book presents many of the molecules and mechanisms generally important in human cancers.

529p tom_123 15-11-2012 36 16   Download

Fetal alcohol syndrome (FAS) is the most common known preventable cause of mental impairment. Babies with FAS have distinctive changes in their facial features and they may be born small. The brain damage that occurs with FAS can result in lifelong problems with learning, memory, attention, and problem solving. These alcohol-related changes in the brain may be present even in babies whose appearance and growth are not affected.

6p connicquy 20-12-2012 27 6   Download

The cellular damage due to the hypoxi/re-oxigenative stress may trigger the production of free radicals with consequent destabilization of the cell membranes (Calandrella et al., 2010). As a matter of fact literature data show that the ischemic insult at retinal level activates iNOS which leads to the production of nitrogen oxide (Goldstein et al., 1995; Geyer et al., 1995): this compound is cytotoxic at high concentration and causes lipid peroxidation (Crow et al., 1996; Ullrich et al., 2000).

498p can_thai 05-09-2012 26 5   Download

All Americans have a stake in effective response to hate crimes. These crimes demand priority attention because of their special impact. Bias crimes are designed to intimidate the victim and members of the victim’s community, leaving them feeling isolated, vulnerable, and unprotected by the law. Failure to address this unique type of crime could cause an isolated incident to explode into widespread community tension. The damage done by hate crimes, therefore, cannot be measured solely in terms of physical injury or dollars and cents.

20p doiroimavanchuadc 06-02-2013 23 4   Download

Tuyển tập các báo cáo nghiên cứu khoa học ngành y học tạp chí Medical Sciences dành cho các bạn sinh viên ngành y tham khảo đề tài: Parvovirus B19 Nonstructural Protein-Induced Damage of Cellular DNA and Resultant Apoptosis...

9p thulanh9 07-10-2011 16 3   Download

On September 7th , Italy signed a bilateral agreement to promote projects in China ahead of the World Expo Shanghai 2010. The agreement is the latest of seven bilateral environmental accords signed by Italy so far this year, and it continues a three-year history of environmental cooperation between Italy and China. The agreement was signed by Corrado Clini, director general of Italy's Environment Ministry, and Xu Zuxin, the head of the Shanghai Environmental Protection Agency.

49p nhacnenzingme 23-03-2013 18 3   Download

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành y học dành cho các bạn tham khảo đề tài: Cellular and molecular mechanisms of cigarette smoke-induced lung damage and prevention by vitamin C...

22p thulanh27 13-12-2011 20 2   Download

During recent decades, attention and concern has been focused increasingly on the environmental impacts of human activities, especially industrial activities such as mining. The public perception of the mining industry has been tainted by a legacy of envi- ronmental damage from past practices combined with a number of highly publicized failures of metal min- ing tailings dams. As the scale of operations and the area disturbed by the mining industry continue to grow, so too has the public's concern over the indus- try's capacity to manage and mitigate environmental impacts.

105p tieuyeuquai456 05-10-2012 19 2   Download

Thymoquinone, a naturally derived agent, has been shown to possess anti-oxidant, antiproliferative and proapoptotic activities. In the present study, we explored thymoquinone effects on the proteasomal complex, the major system involved in the removal of damaged, oxidized and misfolded pro-teins.

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Transportation involves the combustion of fossil fuels to produce energy translated into motion. Pollution is created from incomplete carbon reactions, unburned hydrocarbons or other elements present in the fuel or air during combustion. These processes produce pollutants of various species, including carbon monoxide, soot, various gaseous and liquid vapour hydro carbons, oxides of sulphur and nitrogen, sulphate and nitrate particulates, ash and lead.

55p saimatkhauroi 01-02-2013 17 2   Download

Plasma concentrations of free fatty acids are increased in metabolic syn-drome, and the increased fatty acids may cause cellular damage via the induction of oxidative stress. The present study was designed to determine whether the increase in fatty acids can modify the free sulfhydryl group in position 34 of albumin (Cys34) and enhance the redox-cycling activity of the copper–albumin complex in high-fat diet-induced obese mice.

9p galaxyss3 21-03-2013 14 2   Download

Homocysteine (Hcy) is anonprotein-forming sulphur amino acid that plays an important role in remethylation and trans-sulphuration processes. In recent years, it has been suggested that increased levels of plasma Hcy may play a role in the pathogenesis of various diseases, particularly at the cardiovascular level. The pathogenic mechanism of hyperhomocysteinemia, however, has not been clarified.

6p dell39 03-04-2013 21 2   Download

Cellular manifestations of aging are most pronounced in postmitotic cells, such as neurons and cardiac myocytes. Alterations of these cells, which are responsible for essential functions of brain and heart, are particularly important contributors to the overall aging process. Mitochondria and lysosomes of postmitotic cells suffer the most remarkable age-related alterations of all cellular organelles.

7p research12 01-06-2013 13 2   Download

he tumor suppressor, breast cancer susceptibility gene 1 (BRCA1), plays an integral role in the maintenance of genome stability and, in particular, the cellular response to DNA damage. Here, the emerging role of BRCA1 in nonhomologous end-joining-mediated DNA repair following DNA dam-age will be reviewed, as well as the activation of apoptotic pathways.

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Pyruvate is located at a crucial crossroad of cellular metabolism between the aerobic and anaerobic pathways. Modulation of the fate of pyruvate, in one direction or another, can be important for adaptative response to hypoxia followed by reoxygenation.

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Aging is accompanied by gradual cellular dysfunction associated with an accumulation of damaged proteins, particularly via oxidative processes. This cellular dysfunction has been attributed, at least in part, to impair-ment of mitochondrial function as this organelle is both a major source of oxidants and a target for their damaging effects, which can result in a reduction of energy production, thereby compromising cell function.

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Following their lipophilicity, it is more plausible that vitamin E and ß-carotene cooperate to protect membranes and lipoproteins from oxidative damages. Of course, as all antioxidants, vitamin E exerts other biological functions that are independent from its antioxidant properties, including modulation of cellular signaling, gene expression, immune response, and many more. However, as opposed to other vitamins, lack of vitamin E results in rather unspecific symptoms, also highlighting that this vitamin is mainly needed for its antioxidant activity in vivo.

386p wqwqwqwqwq 23-07-2012 56 5   Download