Search results for "cell damage"
showing 10 items of 38 documents
Impact of therapeutically induced reactive oxygen species and radical scavenging by α-tocopherol on tumor cell adhesion
2007
Many tumor treatment modalities such as ionizing radiation or some chemotherapy induce reactive oxygen species (ROS) resulting in therapeutic cell damage. The aim of this study was to analyze whether such ROS induction may affect the mechanical stability of solid tumor tissue by degradation of the extracellular matrix proteins or by a loss of cell adhesion molecules. Additionally, the protective impact of alpha-tocopherol treatment on these processes was studied. Experimental DS-sarcomas in rats were treated with a combination of localized 44 degrees C hyperthermia, inspiratory hyperoxia and xanthine oxidase in order to induce pronounced oxidative stress. A second group of animals were pret…
Konfokale Laser-Scanning-Mikroskopie (CLSM): Histotomographie veränderter Zahnhartgewebe bei pathologischer Mundhöhlenökologie
1997
There is no consensus regarding the aetiology of radiation-induced caries. Lesion formation is assumed to originate either from direct radiogenic damage of the hard tissue or from the indirect effects correlated with radioxerostomia. A comparative study is presented of sound teeth (group 1), teeth with documented radiation caries (group 2), teeth after in situ radiation (group 3): 60 Gy, fractionated) and teeth after in vitro radiation (group 4: 500-2500 Gy). Radiations were carried out with a 60Co source. The dentoenamel junction was studied with confocal laser scanning microscopy (CLSM). Axial sections of the teeth were used either fresh or embedded in Technovit (sawing-grinding technique…
Host–pathogen interactions in Vibrio vulnificus: responses of monocytes and vascular endothelial cells to live bacteria
2015
ABSTRACT Aim: To demonstrate that Vibrio vulnificus, a sepsis-related aquatic pathogen, can provoke a strong pro-inflammatory reaction in blood-associated target cells. Materials & methods: We selected two strains of the two main phylogenetic lineages, two human cell lines, monocytes and vascular endothelial cells and designed an in vitro infection model simulating early septicemia. Results: Both strains caused a strong cell-specific pro-inflammatory response and produced a high degree of cell damage that ended with death by lysis (endothelial cells) or apoptosis/lysis (monocytes). The interaction with endothelial cells was stronger than expected and significantly different for both l…
Moderate controlled cortical contusion in pigs: effects on multi-parametric neuromonitoring and clinical relevance.
2004
Over the last decade, routine neuromonitoring of ICP and CPP has been extended with new on-line techniques such as microdialysis, tissue oxygen (ptiO(2)), acid-base balance (ptiCO(2), pH) and CBF measurements, which so far have not lead to clear-cut therapy approaches in the neurointensive care unit. This is partially due to the complex pathophysiology following a wide-range of brain injuries, and the lack of suitable animal models allowing simultaneous, clinically relevant neuromonitoring under controlled conditions. Therefore, a controlled cortical impact (CCI) model in large animals (pig) has been developed. After placement of microdialysis, ptiO(2), temperature and ICP catheters, an uni…
Hydrogen peroxide induces programmed cell death features in cultured tobacco BY-2 cells, in a dose-dependent manner
2001
Active oxygen species (AOS), especially hydrogen peroxide, play a critical role in the defence of plants against invading pathogens and in the hypersensitive response (HR). This is characterized by the induction of a massive production of AOS and the rapid appearance of necrotic lesions is considered as a programmed cell death (PCD) process during which a limited number of cells die at the site of infection. This work was aimed at investigating the mode of cell death observed in cultures of BY-2 tobacco cells exposed to H(2)O(2). It was shown that H(2)O(2) is able to induce various morphological cell death features in cultured tobacco BY-2 cells. The hallmarks of cell death observed with fl…
The impact of dehydration rate on the production and cellular location of reactive oxygen species in an aquatic moss.
2012
† Background and Aims The aquatic moss Fontinalis antipyretica requires a slow rate of dehydration to survive a desiccation event. The present work examined whether differences in the dehydration rate resulted in corresponding differences in the production of reactive oxygen species (ROS) and therefore in the amount of cell damage. † Methods Intracellular ROS production by the aquatic moss was assessed with confocal laser microscopy and the ROS-specific chemical probe 2,7-dichlorodihydrofluorescein diacetate. The production of hydrogen peroxide was also quantified and its cellular location was assessed. † Key Results The rehydration of slowly dried cells was associated with lower ROS produc…
Zinc chelation during non-lesioning overexcitation results in neuronal death in the mouse hippocampus
2003
In the hippocampus, chelatable zinc is accumulated in vesicles of glutamatergic presynaptic terminals, abounding specially in the mossy fibers, from where it is released with activity and can exert a powerful inhibitory action upon N-methyl-D-aspartate receptors. Zinc is therefore in a strategic situation to control overexcitation at the zinc-rich excitatory synapses, and consequently zinc removal during high activity might result in excitotoxic neuronal damage. We analyzed the effect of zinc chelation with sodium dietyldithiocarbamate under overexcitation conditions induced by non-lesioning doses of kainic acid in the mouse hippocampus, to get insight into the role of zinc under overexcita…
The Ferroxidase Hephaestin in Lung Cancer: Pathological Significance and Prognostic Value
2021
AbstractIron is a fundamental nutrient utilized by living cells to support several key cellular processes. Despite its paramount role to sustain cell survival, excess of labile iron availability can inflict severe cell damage via reactive oxygen species generation which, in turn, can promote neoplastic transformation. The lung is particularly sensitive to iron-induced oxidative stress, given the high oxygen tensions herein present. Moreover, cigarette smoke as well as air pollution particulate can function as vehicles of iron supply, leading to an iron dysregulation condition shown to be crucial in the pathogenesis of several respiratory diseases including lung cancer. Hephaestin (HEPH) bel…
Development of a nanostructured sensor for monitoring oxidative stress in living cells
2018
Oxidative burden is elevated in the lung of COPD patients and is associated with aging and chronic inflammation. When overcoming physiological levels, reactive oxygen species (ROS) cause cell damage and sustain inflammation. Both lung epithelium and alveolar macrophages contribute to ROS generation. Currently, ROS generation is measured using fluorescent probes and colorimetric/fluorimetric assays. We present an amperometric nanostructured sensor for real-time detection of hydrogen peroxide (H2O2) released by living cells. The H2O2 sensing performance was evaluated through the current vs time response of platinum rod at a working potential of −0.45 V vs saturated calomel electrode acting as…
Apoptosis in liver disease.
2006
The description of the morphological hallmarks of programmed cell death, apoptosis, in 1972 by Kerr, Wyllie and Currie started a field of research that revolutionized our understanding of cellular proliferation, tissue homeostasis and pathophysiology of many diseases. In the following years, a series of proteins involved in signaling and intracellular death pathways were identified and 30 years later the Noble Prize for physiology and medicine was awarded to S. Brenner, H. R. Horvitz and J. E. Sulston for their discoveries related to describing the mechanisms of cell death (apoptosis). The delineation of the signaling pathways that mediate apoptosis changed the paradigms of understanding in…