다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

The recent advances in nanotechnology and the corresponding increase in the use of nanomaterials in products in every sector of society have resulted in uncertainties regarding environmental impacts. The objectives of this review are to introduce the key aspects pertaining to nanomaterials in the environment and to discuss what is known concerning their fate, behavior, disposition, and toxicity, with a particular focus on those that make up manufactured nanomaterials. This review critiques existing nanomaterial research in freshwater, marine, and soil environments. It illustrates the paucity of existing research and demonstrates the need for additional research. Environmental scientists are encouraged to base this research on existing studies on colloidal behavior and toxicology. The need for standard reference and testing materials as well as methodology for suspension preparation and testing is also discussed.

Nanomaterials in the environment: Behavior, fate, bioavailability, and effects

Photodynamic therapy (PDT) employs a non-toxic dye, termed a photosensitizer (PS), and low intensity visible light which, in the presence of oxygen, combine to produce cytotoxic species. PDT has the advantage of dual selectivity, in that the PS can be targeted to its destination cell or tissue and, in addition, the illumination can be spatially directed to the lesion. PDT has previously been used to kill pathogenic microorganisms in vitro, but its use to treat infections in animal models or patients has not, as yet, been much developed. It is known that Gram-(−) bacteria are resistant to PDT with many commonly used PS that will readily lead to phototoxicity in Gram-(+) species, and that PS bearing a cationic charge or the use of agents that increase the permeability of the outer membrane will increase the efficacy of killing Gram-(−) organisms. All the available evidence suggests that multi-antibiotic resistant strains are as easily killed by PDT as naive strains, and that bacteria will not readily develop resistance to PDT. Treatment of localized infections with PDT requires selectivity of the PS for microbes over host cells, delivery of the PS into the infected area and the ability to effectively illuminate the lesion. Recently, there have been reports of PDT used to treat infections in selected animal models and some clinical trials: mainly for viral lesions, but also for acne, gastric infection by Helicobacter pylori and brain abcesses. Possible future clinical applications include infections in wounds and burns, rapidly spreading and intractable soft-tissue infections and abscesses, infections in body cavities such as the mouth, ear, nasal sinus, bladder and stomach, and surface infections of the cornea and skin.

Photodynamic therapy: a new antimicrobial approach to infectious disease?

Phagocyte-derived reactive oxygen and nitrogen species are of crucial importance for host resistance to microbial pathogens. Decades of research have provided a detailed understanding of the regulation, generation and actions of these molecular mediators, as well as their roles in resisting infection. However, differences of opinion remain with regard to their host specificity, cell biology, sources and interactions with one another or with myeloperoxidase and granule proteases. More than a century after Metchnikoff first described phagocytosis, and more than four decades after the discovery of the burst of oxygen consumption that is associated with microbial killing, the seemingly elementary question of how phagocytes inhibit, kill and degrade microorganisms remains controversial. This review updates the reader on these concepts and the topical questions in the field.

Antimicrobial reactive oxygen and nitrogen species: concepts and controversies

The normal biochemical reactions in our body, increased exposure to the environment, and higher levels of dietary xenobiotic's result in the generation of reactive oxygen species (ROS) and reactive nitrogen species (RNS). The ROS and RNS create oxidative stress in different pathophysiological conditions. The reported chemical evidence suggests that dietary antioxidants help in disease prevention. The antioxidant compounds react in one-electron reactions with free radicals in vivo/in vitro and prevent oxidative damage. Therefore, it is very important to understand the reaction mechanism of antioxidants with the free radicals. This review elaborates the mechanism of action of the natural antioxidant compounds and assays for the evaluation of their antioxidant activities. The reaction mechanisms of the antioxidant assays are briefly discussed (165 references). Practical applications: understanding the reaction mechanisms can help in evaluating the antioxidant activity of various antioxidant compounds as well as in the development of novel antioxidants.

https://pubs.rsc.org/en/content/articlepdf/2015/RA/C4RA13315C

Free radicals, natural antioxidants, and their reaction mechanisms

The advent of O2 in the atmosphere was among the first major pollution
events occurred on earth. The reaction between ferrous iron, very abundant in the
reductive early atmosphere, and oxygen results in the formation of harmful superoxide
and hydroxyl radicals, which affect all macromolecules (DNA, lipids and proteins).
Living organisms have to build up mechanisms to protect themselves against oxidative
stress, with enzymes such as catalase and superoxide dismutase, small proteins like
thioredoxin and glutaredoxin, and molecules such as glutathione. Bacterial genetic
responses to oxidative stress are controlled by two major transcriptional regulators
(OxyR and SoxRS). This paper reviews major key points in the generation of reactive
oxygen species in bacteria, defense mechanisms and genetic responses to oxidative
stress. Special attention is paid to the oxidative damage to proteins.

Oxidative stress in bacteria and protein damage by reactive oxygen species.

Yeast cells contain a family of three monothiol glutaredoxins: Grx3, 4, and 5. Absence of Grx5 leads to constitutive oxidative damage, exacerbating that caused by external oxidants. Phenotypic defects associated with the absence of Grx5 are suppressed by overexpression of SSQ1 and ISA2, two genes involved in the synthesis and assembly of iron/sulfur clusters into proteins. Grx5 localizes at the mitochondrial matrix, like other proteins involved in the synthesis of these clusters, and the mature form lacks the first 29 amino acids of the translation product. Absence of Grx5 causes: 1) iron accumulation in the cell, which in turn could promote oxidative damage, and 2) inactivation of enzymes requiring iron/sulfur clusters for their activity. Reduction of iron levels in grx5 null mutants does not restore the activity of iron/sulfur enzymes, and cell growth defects are not suppressed in anaerobiosis or in the presence of disulfide reductants. Hence, Grx5 forms part of the mitochondrial machinery involved in the synthesis and assembly of iron/sulfur centers.

/pdf/grx5-is-a-mitochondrial-glutaredoxin-required-for-the-4q96n2c1cd.pdf

Grx5 Is a Mitochondrial Glutaredoxin Required for the Activity of Iron/Sulfur Enzymes

Identification of the major oxidatively damaged proteins in Escherichia coli cells exposed to oxidative stress.

https://helvia.uco.es/xmlui/bitstream/handle/10396/9734/03.171.pdf?sequence=1

Proteomic and oxidative stress analysis in human brain samples of Huntington disease.

Oxidative damage to specific proteins in replicative and chronological-aged Saccharomyces cerevisiae: common targets and prevention by calorie restriction.

Jordi Tamarit

Papers

Oxidative stress in bacteria and protein damage by reactive oxygen species.

Grx5 Is a Mitochondrial Glutaredoxin Required for the Activity of Iron/Sulfur Enzymes

Identification of the major oxidatively damaged proteins in Escherichia coli cells exposed to oxidative stress.

Proteomic and oxidative stress analysis in human brain samples of Huntington disease.

Oxidative damage to specific proteins in replicative and chronological-aged Saccharomyces cerevisiae: common targets and prevention by calorie restriction.