ABSTRACT
Objective To evaluate the effect of dexmedetomidine pretreatment on the expression of mitochondrial transcription factor A ( TFAM) and succinate dehydrogenase ( SDHA) during lung ischemia-reperfusion ( I∕R) in mice. Methods Twenty-four clean-grade healthy male C57BL∕6J mice, aged 8-10 weeks, weighing 18-22 g, were divided into 3 groups ( n=8 each) using a random number table method:sham operation group ( group S ) , lung I∕R group ( group I∕R ) and dexmedetomidine pretreatment group ( group D) . In I∕R and D groups, lung I∕R was induced by clamping the left pulmonary hilum for 60 min followed by 120-min reperfusion in anesthetized mice. The chest was only opened, but the left pulmonary hilum was not occluded in group S. Dexmedetomidine 25μg∕kg was intraperitoneally injected at 30 min be-fore ischemia in group D, while the equal volume of normal saline was given instead of dexmedetomidine in I∕R and S groups. The mice were sacrificed at 120 min of reperfusion, and lungs were removed for determi-nation of wet∕dry weight ratio ( W∕D ratio) , cell apoptosis ( by TUNEL) and expression of TFAM and SDHA mRNA in lung tissues ( by real-time polymerase chain reaction ) and for examination of the pathological changes of lung tissues. The apoptosis index was calculated. Results Compared with group S, the W∕D ratio, apoptosis index and lung injury scores were significantly increased, and the expression of TFAM and SDHA mRNA was down-regulated in I∕R and D groups ( P<0. 05) . Compared with group I∕R, the W∕D ra-tio, apoptosis index and lung injury scores were significantly decreased, and the expression of TFAM and SDHA mRNA was up-regulated in group D ( P<0. 05) . Conclusion The mechanism by which dexmedeto-midine pretreatment attenuates lung I∕R injury is related to up-regulating the expression of TFAM and SDHA in mice.
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Objective To evaluate the effect of the single energy metal artifact reduction (SEMAR) algorithm with a 320 multi-slice computed tomography (MSCT) volume scanner in patients with knee tumor prostheses.Methods From November 2015 to March 2016,23 consecutive patients with knee tumor prostheses who underwent a 320-MSCT scan were collected.And the raw data were reconstructed using two different methods:conventional iterative reconstruction (IR) alone and IR associated with SEMAR.The ROI were objectively and subjectively assessed at osteotomy level and articular level,and the Wilcoxon signed rank test was used for them.Results Compared with IR,objectively,artifact index (AI) values of the osteotomy level decreased 44.8％ to 74.1％ and that of the articular level decreased 73.2％ to 93.2％;subjectively,the scores of image quality of two levels were increased 0.5 to 2.0 scores and 1.0 to 4.0 scores by SEMAR respectively.The objective and subject image quality of periprosthetic structures were all significantly improved by the SEMAR algorithm (P＜0.05).Conclusion The SEMAR algorithm significantly reduced the metal artifact of knee tumor prostheses,improved the image quality of periprosthetic structures and may increase diagnostic confidence of prosthetic complications in patients with modular knee tumor prostheses,especially at the osteotomy level.
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Objective To evaluate the biodistribution and radiation-absorbed doses of main organs in healthy people with 13 N-ammonia.Methods Five healthy volunteers underwent whole-body PET and CT scans after injection of 666-814 MBq of 13 N-ammonia.The serial dynamic emission images of each healthy volunteer were acquired.ROI were drawn manually based on the transverse CT images and transferred to the corresponding PET slices.Radiation-absorbed doses were calculated using the medical internal radiation dosimetry (MIRD) method.Results The highest concentrations of 13 N-ammonia were found in the heart,liver and kidneys,followed by pancreas,brain,spleen and stomach.The organ of highest absorbed dose was heart with (7.14±3.63) × 10-3 mGy/MBq.The whole-body absorbed dose was (2.11±0.44) × 10 3 mGy/MBq.The whole-body effective dose was (6.58± 1.23) × 10-3 mSv/MBq.Conclusion As one of the most important myocardial perfusion tracers,the whole-body 13 N-NH3 · H2 O PET appears to be safe for humans.
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Objective To investigate the expression of glutamine synthetase ( GS ) in prostate cancer and the utility of 13 N?NH3 PET/CT in detecting prostate cancer. Methods The uptake ratio of 13 N?NH3 and the expression of GS in PC3 and DU145 cells were measured by Western blot and PCR methods. A total of 34 patients with suspected prostate cancer underwent 13 N?NH3 PET/CT imaging and prostate biopsy. Immunohistochemistry staining of GS was performed and Gleason scores of tumors were evaluated. One?way analysis of variance, the least significant difference?t test and Spearman correlation analysis were used to an?alyze data. Results The uptake of 13 N?ammonia in PC3 and DU145 cells elevated along with the decrease of glutamine in medium. The expression of GS mRNA and protein also increased when glutamine was de?creased. In biopsy samples, the mean GS expression scores of prostate cancer, benign prostatic hyperplasia (BPH) and prostatitis were 7.76±2.57, 3.98±2.60, 3.34±0.36, respectively (F=36.85, t1=7.97, t2=4?45, all P<0.05), which had a weak correlation with Gleason scores (rs=0.52, P<0.05). In 34 patients, the mean SUVmax of prostate cancer segments (1.56±0.58 and 1.14±0.22;F=5.966, t1=2.63, t2=2.65, all P<0.05). There was a weak correlation between GS expression scores and the uptake of 13 N?ammonia in prostate cancer (rs=0.47, P<0.05). Conclusions Up?regulated expression of GS is common in prostate cancer cells. GS is the main reason for the uptake of 13 N?ammonia, which is a useful tracer for prostate cancer imaging.