Objective To evaluate and improve the geometrical accuracy of the magnetic resonance imaging used for gamma knife radiosurgery localization. Methods Four common MRI scan programs were used in this study. The images were transferred to the Gamma Plan treatment planning system.Deviations between stereotactic coordinates based on MR images and real geometrical positions given by the construction of the phantom insert were evaluated for each study.The deviations were further investigated as a function of the spatial position of measured points in the investigated volume.Results The geometrical coordinate errors for axial and coronal images of the selected scan programs were all less than 1 mm.Optimal imaging procedure in terms of geometrical accuracy was observed using spin echo T1 and 3D FSPGR MRI sequences in the unit.Statistically significant differences were found in axial images amongSE T1,FSE T2,FRFSE Pd,FSPGR 3D sequences (F=1497.51,1873.63,2.87,3.00,P ＜0.05).The error increased along with the increase of the distance between node point and centricity.Conclusions The geometrical coordinate errors is related with the imaging program in M(il)l. Proper imaging programs and parameters should be selected according to the imageology character of patients' lesions when the radiosurgery is performed.

AIM: To establish a method for determing polysaccaride content of Radix Hedysari(Hedysarum Polybotrys Hand-Mazz). METHODS: To determine content of Radix Hedysari polysaccaride by HPLC and ELSD. RESULTS: The composes of Radix Hedysari polysaccaride Ⅰ、Ⅱ、Ⅲ、Ⅳ are all Rhamnose、Arabinose、Xylose、Glucose、Galactose,the average content of polysaccharides is 25.34%、24.23%、15.08%、17.24%. CONCLUSION: The contents of Radix Hedysari polysaccaride in Radix Hedysari can be determined by HPLC.

The extracellular matrix metalloproteinase inducer (EMMPRIN) has been known to play a key regulatory role in pathological angiogenesis. A elevated activation of vascular endothelial growth factor (VEGF) following radiation injury has been shown to mediate blood-brain barrier (BBB) breakdown. However, the roles of EMMPRIN and VEGF in radiation-induced brain injury after gamma knife surgery (GKS) are not clearly understood. In this study, we investigated EMMPRIN changes in a rat model of radiation injury following GKS and examined potential associations between EMMPRIN and VEGF expression. Adult male rats were subjected to cerebral radiation injury by GKS under anesthesia. We found that EMMPRIN and VEGF expression were markedly upregulated in the target area at 8-12 weeks after GKS compared with the control group by western blot, immunohistochemistry, and RT-PCR analysis. Immunofluorescent double staining demonstrated that EMMPRIN signals colocalized with caspase-3 and VEGF-positive cells. Our data also demonstrated that increased EMMPRIN expression was correlated with increased VEGF levels in a temporal manner. This is the first study to show that EMMPRIN and VEGF may play a role in radiation injuries of the central nervous system after GKS.
Animals ; Antigens, CD147/*metabolism ; Brain/blood supply/metabolism/pathology/*radiation effects ; Brain Injuries/metabolism/pathology ; Caspase 3/metabolism ; Gamma Rays/*adverse effects ; Immunohistochemistry ; Male ; Microscopy, Electron, Transmission ; Parietal Lobe/metabolism/pathology/radiation effects ; Radiation Injuries, Experimental/metabolism ; Radiosurgery/adverse effects ; Rats ; Rats, Wistar ; Time Factors ; Vascular Endothelial Growth Factor A/*metabolism

PET (polyethylene terephthalate) is one of the most important petrochemicals that is widely used in mineral water bottles, food and beverage packaging and textile industry. Because of its stability under environmental conditions, the massive amount of PET wastes caused serious environmental pollution. The use of enzymes to depolymerize PET wastes and upcycling is one of the important directions for plastics pollution control, among which the key is the depolymerization efficiency of PET by PET hydrolase. BHET (bis(hydroxyethyl) terephthalate) is the main intermediate of PET hydrolysis, its accumulation can hinder the degradation efficiency of PET hydrolase significantly, and the synergistic use of PET hydrolase and BHET hydrolase can improve the PET hydrolysis efficiency. In this study, a dienolactone hydrolase from Hydrogenobacter thermophilus which can degrade BHET (HtBHETase) was identified. After heterologous expression in Escherichia coli and purification, the enzymatic properties of HtBHETase were studied. HtBHETase shows higher catalytic activity towards esters with short carbon chains such as p-nitrophenol acetate. The optimal pH and temperature of the reaction with BHET were 5.0 and 55 ℃, respectively. HtBHETase exhibited excellent thermostability, and retained over 80% residual activity after treatment at 80 ℃ for 1 hour. These results indicate that HtBHETase has potential in biological PET depolymerization, which may facilitate the enzymatic degradation of PET.
Hydrolases/metabolism* ; Bacteria/metabolism* ; Hydrolysis ; Polyethylene Terephthalates/metabolism*