The effects of 201Tl myocardial perfusion scintigraphy studies on oxidative damage in patients.

The aim of this study was to investigate gamma radiation-induced oxidative damage in erythrocytes after 201Tl myocardial perfusion scintigraphy. Twenty patients (8 women and 12 men) who performed 201Tl myocardial perfusion scintigraphy were included in this study. The blood samples were taken from patients just before, 1 hour after and three hours after injection of the radiopharmaceutical. Malondialdehyde (MDA) and antioxidant enzymes such as glutathione peroxidase (GPX), superoxide dismutase (SOD) and catalase (CAT) levels were measured to evaluate the gamma radiation induced oxidative damage. The enzyme activities of SOD, GPX and CAT were decreased 1 hour after (p = 0.042, p = 0.697 and p = 0.653 respectively) and 3 hours after (p = 0.003, p = 0.573 and p = 0.002 respectively) injection of the radiopharmaceutical. Malondialdehyde levels were increased 1 hour after (p = 0.10) and 3 hours after (p = 0.47) injection of the radiopharmaceutical. In this study, we found that radiation due to 201Tl myocardial perfusion scintigraphy decreased the erythrocyte antioxidant levels and increased MDA levels.

The effects of 201Tl myocardial perfusion scintigraphy studies on oxidative damage in patients / Efectos de los estudios de escintigrafía de perfusión miocárdica 201Tl sobre el daño oxidativo en los pacientes

The aim of this study was to investigate gamma radiation-induced oxidative damage in erythrocytes after 201Tl myocardial perfusion scintigraphy. Twenty patients (8 women and 12 men) who performed 201Tl myocardial perfusion scintigraphy were included in this study. The blood samples were taken from patients just before, 1 hour after and three hours after injection of the radiopharmaceutical. Malon-dialdehyde (MDA) and antioxidant enzymes such as glutathione peroxidase (GPX), superoxide dismutase (SOD) and catalase (CAT) levels were measured to evaluate the gamma radiation induced oxidative damage. The enzyme activities of SOD, GPX and CAT were decreased 1 hour after (p = 0.042, p = 0. 697 and p = 0.653 respectively) and 3 hours after (p = 0.003, p = 0. 573 and p = 0.002 respectively) injection of the radiopharmaceutical. Malondialdehyde levels were increased 1 hour after (p = 0.10) and 3 hours after (p = 0.47) injection of the radiopharmaceutical. In this study, we found that radiation due to 201Tl myocardial perfusion scintigraphy decreased the erythrocyte antioxidant levels and increased MDA levels.

El objetivo de este estudio fue investigar el daño oxidativo inducido por radiaciones gamma, sobre los eritrocitos luego de realizada una escintigrafía de perfusión miocárdica 201Tl. Veinte pacientes (8 mujeres y 12 hombres) a quienes se les realizó escintigrafía por perfusión miocárdica 201Tl, fueron incluidos en este estudio. Las muestras de sangre fueron tomadas de los pacientes antes, 1 hora más tarde, y tres horas después de inyectar el radiofármaco. Se midieron los niveles del malondialdehido (MDA) y las enzimas antioxidantes tales como la glutationa peroxidasa (GPX), superóxido dismutasa (SOD), y la catalasa (CAT), a fin de evaluar el daño oxidativo inducido por la radiación gamma. Las actividades de las enzimas SOD, GPX y CAT fueron disminuidas 1 horas después (p = 0.042, p = 0. 697 y p = 0.653 respectivamente) y tres horas (p = 0.003, p = 0. 573 y p = 0.002 respectivamente) tras la inyección del radiofármaco. Los niveles de malondialdehido fueron aumentados 1 hora después (p = 0.10) y tres horas después (p = 0.47) de la inyección del radiofármaco. En este estudio, hallamos que la radiación a causa de la escintigrafía de perfusión miocárdica 201Tl disminuyó los niveles antioxidantes del eritrocito y aumentó los niveles de MDA.

The effects of thyroid scintigraphy studies on oxidative damage in patients.

The majority of radiation injury in cells depends on oxidative stress. Irradiation and absorbed doses, duration of the irradiation and the susceptibility of the tissue against radiation are the factors that cause variations on living cells. The aim of this study was to investigate gamma radiation-induced oxidative damage in erythrocytes after thyroid scintigraphy with Tc-99m pertechnetate. Fifteen patients (8 women and 7 men) who performed thyroid scintigraphy with Tc-99m pertechnetate were included in this study. The median age was 52 +/- 8 years (range 33-65). The blood samples were taken from patients just before, 1 hour after and three hours after injection of radiopharmaceutical. Malondialdehyde (MDA) and antioxidant enzymes such as glutathione peroxidase (GPX), superoxide dismutase (SOD), and catalase (CAT) levels were measured to evaluate the gamma radiation induced oxidative damage. No difference was detected in any final measurement activities of erythrocyte antioxidant enzyme such as SOD and GPX in the direct comparison between the before and after injection of the radiopharmaceutical groups, except erythrocyte CAT activities measured 1 hour after and 3 hours after injection of the radiopharmaceutical (p < 0.05). MDA levels were decreased 1 hour after and 3 hours after injection of the radiopharmaceutical.

Powder MAS NMR lineshapes of quadrupolar nuclei in the presence of second-order quadrupole interaction.

We derive a complete analytical solution for the powder magic angle spinning (MAS) nuclear magnetic resonance (NMR) lineshape in the presence of second-order quadrupole interaction, considering a radiofrequency (rf) pulse of finite width, a finite MAS frequency, and a non-zero asymmetry parameter. (Ix) is calculated using two approaches. The first applies time-dependent perturbation theory in the presence of the rf pulse and stationary perturbation theory (SPT) in its absence. The second is based on the Magnus expansion of the density matrix in the interaction representation during the pulse and SPT in its absence. We solve the problem in the laboratory frame using the properties of the Fourier transform and spin operators. Diagonalisation is not required. Both approaches agree well with each other under all conditions and also with the transition probability approach for the central transition. The Magnus expansion exists at all times and the effect of the non-secular terms is negligible. We describe an analytical method of averaging (Ix) over the Euler angles and simulate the 11B MAS NMR lineshapes for crystalline and vitreous B2O3. A critical analysis is given of all earlier calculations of the MAS NMR lineshape.

Transverse relaxation times of spin 3/2 nuclei in the quadrupole nutation NMR experiment.

Transverse relaxation times in the rotating frame of quadrupolar nuclei with half-integer spins are inversely proportional to the linewidth of quadrupole nutation NMR spectra. We apply fictitious spin -1/2 operators to I = 3/2 nuclei to derive correlations between the transitions of a multi-level system which affect nuclear relaxation. When omega rf << omega Q, all possible multiple-quantum transitions contribute to the transverse quadrupolar relaxation time in the rotating frame T2Qp. When omega rf >> omega Q, two of the three single-quantum transitions do not contribute. In the low-temperature region (outside the extreme narrowing limit), the contribution of double- and triple-quantum coherences to T2Qp goes through a minimum for omega rf << omega Q, while the triple-quantum coherence appears at zero frequency and corresponds to a short transverse relaxation time for omega rf >> omega Q.