Endothelium-Derived Hyperpolarizing Factor as a Reserve Defense Mechanism of the Vascular Control under Ionizing Radiation Impact

Author(s):  
Irina V. Ivanova ◽  
Olga V. Kislova ◽  
Anatoly I. Soloviev
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ankit Chauhan ◽  
Dhananjay Kumar Sah ◽  
Neeraj Kumari ◽  
Namita Kalra ◽  
Ravi Soni ◽  
...  

AbstractExposure to Ionizing radiation (IR) poses a severe threat to human health. Therefore, there is an urgent need to develop potent and safe radioprotective agents for radio-nuclear emergencies. Phosphatidylinositol-3-kinase (PI3K) mediates its cytoprotective signaling against IR by phosphorylating membrane phospholipids to phosphatidylinositol 3,4,5 triphosphate, PIP3, that serve as a docking site for AKT. Phosphatase and Tensin Homolog on chromosome 10 (PTEN) antagonizes PI3K activity by dephosphorylating PIP3, thus suppressing PI3K/AKT signaling that could prevent IR induced cytotoxicity. The current study was undertaken to investigate the radioprotective potential of PTEN inhibitor (PTENi), bpV(HOpic). The cell cytotoxicity, proliferation index, and clonogenic survival assays were performed for assessing the radioprotective potential of bpV(HOpic). A safe dose of bpV(HOpic) was shown to be radioprotective in three radiosensitive tissue origin cells. Further, bpV(HOpic) significantly reduced the IR-induced apoptosis and associated pro-death signaling. A faster and better DNA repair kinetics was also observed in bpV(HOpic) pretreated cells exposed to IR. Additionally, bpV(HOpic) decreased the IR-induced oxidative stress and significantly enhanced the antioxidant defense mechanism in cells. The radioprotective effect of bpV(HOpic) was found to be AKT dependant and primarily regulated by the enhanced glycolysis and associated signaling. Furthermore, this in-vitro observation was verified in-vivo, where administration of bpV(HOpic) in C57BL/6 mice resulted in AKT activation and conferred survival advantage against IR-induced mortality. These results imply that bpV(HOpic) ameliorates IR-induced oxidative stress and cell death by inducing AKT signaling mediated antioxidant defense system and DNA repair pathways, thus strengthening its potential to be used as a radiation countermeasure.


Author(s):  
M. L. Knotek

Modern surface analysis is based largely upon the use of ionizing radiation to probe the electronic and atomic structure of the surfaces physical and chemical makeup. In many of these studies the ionizing radiation used as the primary probe is found to induce changes in the structure and makeup of the surface, especially when electrons are employed. A number of techniques employ the phenomenon of radiation induced desorption as a means of probing the nature of the surface bond. These include Electron- and Photon-Stimulated Desorption (ESD and PSD) which measure desorbed ionic and neutral species as they leave the surface after the surface has been excited by some incident ionizing particle. There has recently been a great deal of activity in determining the relationship between the nature of chemical bonding and its susceptibility to radiation damage.


2004 ◽  
Vol 171 (4S) ◽  
pp. 344-344
Author(s):  
Jonathan E. Bernie ◽  
Chandru P. Sundaram,

VASA ◽  
2001 ◽  
Vol 30 (Supplement 58) ◽  
pp. 6-14 ◽  
Author(s):  
Edmonds ◽  
Foster

The diabetic ischaemic foot has become an increasingly frequent problem over the last decade. However, we report a new approach consisting of a basic classification, a simple staging system of the natural history and a treatment plan for each stage, within a multi-disciplinary framework. This approach of "taking control" consists of two parts: 1. long-term conservative care including debridement of ulcers (to obtain wound control), eradication of sepsis (micribiological control), and provision of therapeutic footwear (mechanical control), and 2. revascularisation by angioplasty and arterial bypass (vascular control). This approach has led to a 50% reduction in the rate of major amputations in patients attending with ischaemic ulceration and absent foot pulses from 1989 to 1999 (from 4.6% to 2.3% per year). Patients who underwent angioplasty increased from 6% to 13%. Arterial bypass similarly increased from 3% to 7% of cases. However, even with an increased rate of revascularisation, 80% of patients responded to conservative care alone. This,we conclude, is an essential part of the management of all patients with ischaemic feet.


Author(s):  
Olya Khaleelee

This paper describes the use of the Defense Mechanism Test as an aid in helping to assess senior executives in four areas: for selection, development, career strategy, and crisis intervention. The origins of this test, developed to measure the defense mechanisms used to protect the individual from stress, are described. The paper shows how it was used to predict the capacity of trainee fighter pilots to withstand stress and its later application to other stressful occupations. Finally, some ideal types of the test are shown followed by four real test profiles, two of them with their associated histories.


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