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41 záznamů v Medvik Filtry

Článek

Particles with similar LET values generate DNA breaks of different complexity and reparability: a high-resolution microscopy analysis of gammaH2AX/53BP1 foci

Nanoscale. 2018 ; 10 (3) : 1162-1179.

ISSN 2040-3364
Medvik
Zdroj

Biological effects of high-LET (linear energy transfer) radiation have received increasing attention, particularly in the context of more efficient radiotherapy and space exploration. Efficient cell killing by high-LET radiation depends on the physical ability of accelerated particles to generate complex DNA damage, which is largely mediated by LET. However, the characteristics of DNA damage and repair upon exposure to different particles with similar LET parameters remain unexplored. We employed high-resolution confocal microscopy to examine phosphorylated histone H2AX (gammaH2AX)/p53-binding protein 1 (53BP1) focus streaks at the microscale level, focusing on the complexity, spatiotemporal behaviour and repair of DNA double-strand breaks generated by boron and neon ions accelerated at similar LET values (~135 keV mum-1) and low energies (8 and 47 MeV per n, respectively). Cells were irradiated using sharp-angle geometry and were spatially (3D) fixed to maximize the resolution of these analyses. Both high-LET radiation types generated highly complex gammaH2AX/53BP1 focus clusters with a larger size, increased irregularity and slower elimination than low-LET gamma-rays. Surprisingly, neon ions produced even more complex gammaH2AX/53BP1 focus clusters than boron ions, consistent with DSB repair kinetics. Although the exposure of cells to gamma-rays and boron ions eliminated a vast majority of foci (94% and 74%, respectively) within 24 h, 45% of the foci persisted in cells irradiated with neon. Our calculations suggest that the complexity of DSB damage critically depends on (increases with) the particle track core diameter. Thus, different particles with similar LET and energy may generate different types of DNA damage, which should be considered in future research.

MeSH
53BP1 * chemie MeSH
apoptóza MeSH
dvouřetězcové zlomy DNA * MeSH
fibroblasty účinky záření MeSH
fluorescenční protilátková technika MeSH
fosforylace MeSH
histony * chemie MeSH
ionizující záření MeSH
konfokální mikroskopie * MeSH
kultivované buňky MeSH
lidé MeSH
lineární přenos energie * MeSH
oprava DNA MeSH
Check Tag
lidé MeSH

Článek

Oboustranný spontánní pneumotorax – kazuistika
[Bilateral spontaneous pneumothorax – a case review]

Rozhledy v chirurgii. 2008 ; 87 (12) : 622-623.

ISSN 0035-9351
Medvik
Zdroj

Formou kazuistiky popsán případ oboustranného primárního spontánního pneumotoraxu. Nespolupracující pacient, 20letý schizofrenik, byl zpočátku léčen konzervativně. Drenáž sama nestačila ani na jedné straně ke zvládnutí stavu. Ten byl vyřešen až oboustrannou operací.

In this article, we present a case study involving a patient with bilateral primary spontaneous pneumothorax. The patient was an uncooperative 20 year old male treated for schizophrenia. Initially, the pneumothorax was treated by conservative measures. Bilateral chest tube drainage proved to be ineffective in treating the patient's condition. This was eventually managed only after bilateral surgery.