Different Oxygen Enhancement Ratios for Induced and Unrejoined DNA Double-Strand Breaks in Eukaryotic Cells

Frankenberg-Schwager, M.; Frankenberg, D.; Harbich, R.

doi:10.2307/3578046

Cited by 21 publications

(9 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Although 60 Gy of radiation is usually curative for tumor cell killing under normoxia, it would require > 150 Gy to reach the same killing for hypoxic cells (60 · 2.5 or 3) (163). In addition, in the absence of oxygen, decreased DNA DSBs are produced by free radicals after radiation therapy and/or the damaged products are repairable (73,164,216,231).…”

Section: Impact Of Tumor Hypoxia On Radiation Therapymentioning

confidence: 99%

Imaging Tumor Hypoxia to Advance Radiation Oncology

Lee

Boss

Dewhirst

2014

Antioxidants & Redox Signaling

View full text Add to dashboard Cite

Significance: Most solid tumors contain regions of low oxygenation or hypoxia. Tumor hypoxia has been associated with a poor clinical outcome and plays a critical role in tumor radioresistance. Recent Advances: Two main types of hypoxia exist in the tumor microenvironment: chronic and cycling hypoxia. Chronic hypoxia results from the limited diffusion distance of oxygen, and cycling hypoxia primarily results from the variation in microvessel red blood cell flux and temporary disturbances in perfusion. Chronic hypoxia may cause either tumor progression or regressive effects depending on the tumor model. However, there is a general trend toward the development of a more aggressive phenotype after cycling hypoxia. With advanced hypoxia imaging techniques, spatiotemporal characteristics of tumor hypoxia and the changes to the tumor microenvironment can be analyzed. Critical Issues: In this review, we focus on the biological and clinical consequences of chronic and cycling hypoxia on radiation treatment. We also discuss the advanced non-invasive imaging techniques that have been developed to detect and monitor tumor hypoxia in preclinical and clinical studies. Future Directions: A better understanding of the mechanisms of tumor hypoxia with non-invasive imaging will provide a basis for improved radiation therapeutic practices. Antioxid. Redox Signal. 21, 313-337.

show abstract

Section: Impact Of Tumor Hypoxia On Radiation Therapymentioning

confidence: 99%

Imaging Tumor Hypoxia to Advance Radiation Oncology

Lee

Boss

Dewhirst

2014

Antioxidants & Redox Signaling

View full text Add to dashboard Cite

show abstract

“…Under acute hypoxia or anoxia, fewer breaks are generated due to the decreased oxygen which is normally required for the fixation of DNA damage under oxic conditions [35][36][37][38][39][40][41][42]. This is quantified by an oxygen enhancement ratio (OER), defined as the ratio of doses required for the same biological effect (e.g.…”

Section: Hypoxia Cellular Radiosensitivity and The Oxygen Enhancemenmentioning

confidence: 99%

Tumor Hypoxia as a Modifier of DNA Strand Break and Cross-Link Repair

Chan

Koch

Bristow

2009

CMM

View full text Add to dashboard Cite

Hypoxia is a common characteristic of many solid tumors and is associated with poor prognosis. Cells with low oxygen levels can have altered sensitivity to radiotherapy and chemotherapy secondary to changes in the incidence of DNA single- and double-strand breaks (DNA-ssb, DNA-dsb), DNA base damage, DNA-DNA cross-links and DNA-protein cross-links. Recent evidence also supports that cells exposed to chronic hypoxia have a decreased capacity of DNA-dsb repair. This review will examine the influence of short-term and prolonged hypoxia on the two major pathways of DNA-dsb repair: homologous recombination (HR) and non-homologous end-joining (NHEJ). Novel treatment strategies designed to exploit the hypoxic tumor microenvironment are also discussed. Modification of DNA damage sensing and repair due to fluctuating oxygen levels within a dynamic tumor microenvironment may have profound implications for tumor progression and treatment.

show abstract

“…Score range 6–10 was defined as oversedation; score range 23–30 as undersedation. Score range 11–22 was defined as a gray area in which a second assessment, for example the Nurse Interpretation of Sedation Score (NISS), is recommended for clinical purposes (12, 17). …”

Section: Sedation Assessmentmentioning

confidence: 99%

Sedation in Critically Ill Children with Respiratory Failure

Vet¹,

Kleiber²,

Ista³

et al. 2016

Front. Pediatr.

View full text Add to dashboard Cite

This article discusses the rationale of sedation in respiratory failure, sedation goals, how to assess the need for sedation as well as effectiveness of interventions in critically ill children, with validated observational sedation scales. The drugs and non-pharmacological approaches used for optimal sedation in ventilated children are reviewed, and specifically the rationale for drug selection, including short- and long-term efficacy and safety aspects of the selected drugs. The specific pharmacokinetic and pharmacodynamic aspects of sedative drugs in the critically ill child and consequences for dosing are presented. Furthermore, we discuss different sedation strategies and their adverse events, such as iatrogenic withdrawal syndrome and delirium. These principles can guide clinicians in the choice of sedative drugs in pediatric respiratory failure.

show abstract

Different Oxygen Enhancement Ratios for Induced and Unrejoined DNA Double-Strand Breaks in Eukaryotic Cells

Cited by 21 publications

References 26 publications

Imaging Tumor Hypoxia to Advance Radiation Oncology

Imaging Tumor Hypoxia to Advance Radiation Oncology

Tumor Hypoxia as a Modifier of DNA Strand Break and Cross-Link Repair

Sedation in Critically Ill Children with Respiratory Failure

Contact Info

Product

Resources

About