RESUMEN
BACKGROUND: Radiotherapy of the thorax often causes lung inflammation leading to fibrosis. OBJECTIVES: The aim of this study was to investigate whether the use of glycyrrhizic acid (GLA) could improve the development of lung fibrosis in irradiated animals. MATERIALS AND METHODS: Wistar rats were divided into four groups. Group A rats received thoracic irradiation. Rats in group B received GLA and irradiation. Group C received GLA and no irradiation. Group D received no GLA and irradiation. GLA was administered at a dose of 4 mg/kg body weight using an intraperitoneal injection one hour before thoracic irradiation. Radiation therapy was delivered on a Cobalt-60 unit using a single fraction of 16 Gy. The animals were sacrificed at 32 weeks following thoracic irradiation. The lungs were dissected and blind histopathological evaluation was performed. RESULTS: Histopathologically, a decrease (statistically not significant) in the thickening of alveolar or bronchial wall, formation of fibrous bands, and superimposed collagen were noted in the animals in group B as compared to the animals in group A. CONCLUSION: In this experimental study, administration of GLA one hour before thoracic irradiation may be a protective agent against radiation-induced fibrosis in animals and this model could be used in future studies.
RESUMEN
To evaluate the ability of glycyrrhizic acid (GLA) to reduce the tumor necrosis factor α (TNF-α), release on messenger ribonucleic acid (mRNA) and protein production in the lungs using GLA in response to irradiation were studied. The animals were divided into four groups: No treatment (NT group), GLA treatment only (GLA group), irradiation only (XRT group), and GLA treatment plus irradiation (GLA/XRT group). Rats were killed at different time points. Real-time reverse transcriptase polymerase chain reaction (RT-PCR) was used to evaluate the mRNA expression of TNF-α in the lungs (compared with non-irradiated lungs). An enzyme-linked immunosorbant assay (ELISA) assay was used to measure the TNF-α protein level. The TNF-α mRNA expression in the lungs of the XRT rats was clearly higher at all-time points compared to the NT rats. The TNF-α mRNA expression in the lungs of the GLA/XRT rats was lower at all-time points compared to the XRT rats. Release of the TNF-α on protein level in the lungs of the XRT rats increased at all-time points compared to the NT rats. In contrast to the XRT rats, the lungs of the GLA/XRT rats revealed a reduction on TNF-α protein level at 6 h after irradiation. This study has clearly showed the immediate down-regulation of the TNF-α mRNA and protein production in the lungs using GLA in response to irradiation.
RESUMEN
BACKGROUND: Magnetic nanoparticles have been widely applied in recent years for biomedical applications. Signal intensity (SI) of magnetic resonance (MR) images depends on the concentration of nanoparticles. It is important to find the minimum concentration of iron oxide nanoparticles that produces maximum SI and determines the minimum injection dose for clinical studies. OBJECTIVES: This study was performed to determine the relationship between the iron oxide nanoparticle concentration and SI using inversion recovery (IR) sequence in T1-weighted MR images. MATERIALS AND METHODS: Different concentrations of carboxydextran-coated iron oxide nanoparticles 20 nm in size were prepared. In vitro MR imaging was performed with inversion times (TI) of 100-400 ms (interval of 20 ms) and IR Turbo-FLASH (Turbo fast low angle shot) pulse sequence using a 1.5 T MRI system. Then the SI produced by each concentration of nanoparticles was measured and the minimum nanoparticle concentration that led to the maximum SI was determined. Coil non-uniformity was also considered for measuring the accurate SI of each image. RESULTS: The results indicate that SI depended on the concentration of nanoparticles and TI. In addition, SI increased by increasing the TIs ranging from 200 to 400 ms for all studied concentrations. The linear relationship between the nanoparticle concentrations and SI that gave a square correlation coefficient (R(2)) equal to 0.99 was seen up to 76.83 µmol Fe/L in 400 ms for long TI and 239.16 µmol Fe/L in 200 ms for short TI. CONCLUSIONS: TI is an important parameter to consider in the relationship between SI and nanoparticle concentrations. An increase in TI leads to a decrease in the range of linearity.
RESUMEN
Ultrasound is one of the preferred modalities for evaluation of the parathyroid glands. This study was undertaken to determine the accuracy of high resolution ultrasound for secondary hyperparathyroidism in patients with chronic renal failure. From March 2008 to March 2009, ninety-one hemodialysis patients were examined by high resolution ultrasound (14 MHz) of the parathyroid glands in comparison to parathyroid hormone level. 43.9% of patients showed enlarged parathyroid glands with an average of 8.7 mm. The mean parathyroid hormone level of patients with enlarged parathyroid glands on sonography was 503 ± 450 pg/ml. We observed a significant correlation between parathyroid hormone level and enlarged parathyroid glands (P<0.0001). Sensitivity and specificity of sonography for detection of secondary hyperparathyroidism were 62.5% and 85.7% respectively. In conclusion, our study showed that high resolution sonography is a useful noninvasive method for the evaluation of secondary hyperparathyroidism in patients on hemodialysis and that sonographically enlarged glands may be a measure of severity of secondary hyperparathyroidism.
