The aim of this paper is to investigate the possibility of using detectors based on LaBr3(Ce) scintillation crystal as part of gamma spectrometry systems for field use and possibly as part of a monitoring network around nuclear power plants, i.e. whether LaBr3(Ce) detectors can follow the classical scintillation detectors based on NaI (Tl). For this purpose, the Monte Carlo simulation of the IPROL-1 probe response was performed in the simplified geometry of the radionuclides-contaminated atmosphere. A study shows that a LaBr3(Ce)-based probe is usable for this purpose and results are at least comparable to those with a conventional NaI (Tl)-based probe.
- MeSH
- dávka záření MeSH
- havárie elektrárny Fukušima MeSH
- jaderné elektrárny * MeSH
- lidé MeSH
- metoda Monte Carlo MeSH
- monitorování radiace přístrojové vybavení metody MeSH
- počítačová simulace * MeSH
- radiační expozice analýza MeSH
- radioaktivní látky znečišťující vzduch analýza MeSH
- záření gama MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
INTRODUCTION: Propofol causes a profound inhibition of fatty acid oxidation and reduces spare electron transfer chain capacity in a range of human and rodent cells and tissues-a feature that might be related to the pathogenesis of Propofol Infusion Syndrome. We aimed to explore the mechanism of propofol-induced alteration of bioenergetic pathways by describing its kinetic characteristics. METHODS: We obtained samples of skeletal and cardiac muscle from Wistar rat (n = 3) and human subjects: vastus lateralis from hip surgery patients (n = 11) and myocardium from brain-dead organ donors (n = 10). We assessed mitochondrial functional indices using standard SUIT protocol and high resolution respirometry in fresh tissue homogenates with or without short-term exposure to a range of propofol concentration (2.5-100 μg/ml). After finding concentrations of propofol causing partial inhibition of a particular pathways, we used that concentration to construct kinetic curves by plotting oxygen flux against substrate concentration during its stepwise titration in the presence or absence of propofol. By spectrophotometry we also measured the influence of the same propofol concentrations on the activity of isolated respiratory complexes. RESULTS: We found that human muscle and cardiac tissues are more sensitive to propofol-mediated inhibition of bioenergetic pathways than rat's tissue. In human homogenates, palmitoyl carnitine-driven respiration was inhibited at much lower concentrations of propofol than that required for a reduction of electron transfer chain capacity, suggesting FAO inhibition mechanism different from downstream limitation or carnitine-palmitoyl transferase-1 inhibition. Inhibition of Complex I was characterised by more marked reduction of Vmax, in keeping with non-competitive nature of the inhibition and the pattern was similar to the inhibition of Complex II or electron transfer chain capacity. There was neither inhibition of Complex IV nor increased leak through inner mitochondrial membrane with up to 100 μg/ml of propofol. If measured in isolation by spectrophotometry, propofol 10 μg/ml did not affect the activity of any respiratory complexes. CONCLUSION: In human skeletal and heart muscle homogenates, propofol in concentrations that are achieved in propofol-anaesthetized patients, causes a direct inhibition of fatty acid oxidation, in addition to inhibiting flux of electrons through inner mitochondrial membrane. The inhibition is more marked in human as compared to rodent tissues.
- MeSH
- druhová specificita MeSH
- krysa rodu rattus MeSH
- lidé středního věku MeSH
- lidé MeSH
- mastné kyseliny metabolismus MeSH
- oxidace-redukce účinky léků MeSH
- potkani Wistar MeSH
- propofol farmakologie MeSH
- respirační komplex I metabolismus MeSH
- respirační komplex IV metabolismus MeSH
- senioři MeSH
- srdeční mitochondrie metabolismus MeSH
- svalové mitochondrie metabolismus MeSH
- vztah mezi dávkou a účinkem léčiva MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- MeSH
- dávka záření MeSH
- krev účinky záření MeSH
- lidé MeSH
- metoda Monte Carlo MeSH
- počítačová simulace MeSH
- radioizotopy kobaltu * terapeutické užití MeSH
- recyklace * metody normy MeSH
- statistika jako téma MeSH
- teoretické modely MeSH
- záření gama škodlivé účinky terapeutické užití MeSH
- zařízení a zdroje radiace * MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- práce podpořená grantem MeSH
- Klíčová slova
- FSTR, protonový svazek, geometrie, úhlově-energetické distribuce, ozařovací místnost, Protonové terapeutické centrum Praha,
- MeSH
- dávka záření MeSH
- fotony MeSH
- lidé MeSH
- matematika * MeSH
- metoda Monte Carlo MeSH
- monitorování radiace * MeSH
- nemocniční oddělení organizace a řízení MeSH
- neutrony MeSH
- protony MeSH
- radiační ochrana metody přístrojové vybavení statistika a číselné údaje MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- práce podpořená grantem MeSH
