ABSTRACT
Purpose: The aim of the study is to study the feasibility of gamma-ray-detection-based precision dose measurement of 125I seed brachytherapy in solid water. Materials and Methods: Seven group 125I seeds with different activities were put into a hole in the center of solid water individually. Each group had ten seeds, and the seed activity ranged from 1.48 × 107 Bq to 3.7 × 107 Bq. Single-photon emission computed tomography/computed tomography (SPECT/CT) was used to scan the seeds perpendicular to the long axis of the seed, with a slice thickness of 3.75 mm. The radioactive count values (x) of the radioactive concentration around the seeds were collected at a distance of 1–15 mm from the center of the seeds, while the corresponding doses (Y) (Gy) were calculated. SPSS 18.0 was used to analyze the relationship between the count value and the dose. Results: With the same seed activity, the count values became smaller according to the distance from the center of the seeds. The count values at the same point had an increasing trend according to the activity. This is similar to the doses calculated at the same point. There was an exponential relationship between the dose around the 125I seeds, and the radioactive count value detected by SPECT/CT. Correlative curves between the dose and radioactive count value detected by SPECT/CT of different-activity 125I seeds were fitted. The formulas of the dose and radioactive count with different seed activity were in the form of Y = b0 (b1)x. The constant b0 ranged from 1.48 to 3.93, according to the seed activity, while b1 was 1.006 for every seed's activity. Conclusion: The count value around the 125I seed can be detected accurately by SPECT/CT, and then can be quantified. This study provided useful experiment data for the precision measurement of 125I seed implantation. Radiation detection-based dose measurement may become a new noninvasive technology for the dynamic dosimetry verification method after brachytherapy
ABSTRACT
Objective: To explore the effect of erythromycin on hyperoxia-induced lung injury. Methods: One-day-old preterm offspring Sprague-Dawley (SD) rats were randomly divided into four groups: group 1, air + sodium chloride; group 2, air + erythromycin;group 3, hyperoxia + sodium chloride; and group 4, hyperoxia + erythromycin. At one, seven, and 14 days of exposure, glutathione (GSH) and interleukin-1 beta (IL-1 beta) were detected by double-antibody sandwich enzyme-linked immunosorbent assay (ELISA), and bicinchoninic acid (BCA) was used to detect GSH protein. γ-glutamine-cysteine synthetase (γ-GCS) mRNA was detected by reverse transcription-polymerase chain reaction (RT-PCR). Results: Compared with group 1, expressions of GSH and γ-GCS mRNA in group 3 were significantly increased at one and seven days of exposure (p < 0.05), but expression of γ-GCS mRNA was significantly reduced at 14 days; expression of IL-1 beta in group 3 was significantly increased at seven days of exposure (p < 0.05), and was significantly reduced at 14 days. Compared with group 3, expressions of GSH and γ-GCS mRNA in group 4 were significantly increased at one, seven, and 14 days of exposure (p < 0.05), but expressions of GSH showed a downward trend at 14 days; expression of IL-1 beta in group 4 was significantly reduced at one and seven days of exposure (p < 0.05). Conclusions: Changes in oxidant-mediated IL-1 beta and GSH are involved in the development of hyperoxia-induced lung injury. Erythromycin may up-regulate the activity of γ-GCS, increasing the expression of GSH, inhibiting the levels of oxidant-mediated IL-1 beta and alleviating hyperoxia-induced lung injury via an antioxidant effect. .
Objetivo: Explorar o efeito da eritromicina sobre lesões pulmonares induzidas por hiperóxia. Métodos: Uma prole de ratos Sprague-Dawley (SD) prematuros com um dia de vida foi dividida aleatoriamente em quatro grupos: grupo 1 ar + cloreto de sódio, grupo 2 ar + eritromicina, grupo 3 hiperóxia + cloreto de sódio e grupo 4 hiperóxia + eritromicina. Com um, sete e 14 dias de exposição, foram detectadas Glutationa (GSH) e Interleucina-1 beta (IL-1 beta) pelo ensaio imunossorvente ligado à enzima (ELISA), e o ácido bicinconinico (BCA) foi utilizado para detectar a proteína GSH. O mRNA da γ-glutamil-cisteina-sintetase (γ-GCS) foi detectado por reação em cadeia da polimerase via transcriptase reversa (RT-PCR). Resultados: Comparadas ao grupo 1, as expressões do mRNA da GSH e da γ-GCS no grupo 3 aumentaram significativamente com um e sete dias de exposição (p < 0,05), porém a expressão de mRNA da γ-GCS diminuiu significativamente aos 14 dias; a expressão de IL-1 beta no grupo 3 aumentou significativamente aos 7 dias de exposição (p < 0,05) e diminuiu significativamente aos 14 dias. Comparadas ao grupo 3, as expressões do mRNA da GSH e da γ-GCS no grupo 4 aumentaram significativamente com um, sete e 14 dias de exposição (p < 0,05), porém as expressões de GSH mostraram uma tendência de queda aos 14 dias; a expressão de IL-1 beta no grupo 4 foi reduzida significativamente com um e sete dias de exposição (p < 0,05). Conclusões: As variações de IL-1 beta e GSH mediadas por oxidantes estão envolvidas no desenvolvimento de lesão pulmonar induzida por hiperóxia. A eritromicina poderá regular positivamente a atividade da γ-GCS, aumentando a expressão de GSH, inibindo os níveis de interleucina-1beta mediada por ...