Objective: Our purpose was to evaluate a new kind of tomographic phase analysis in Wolff-Parkinson-White (WPW) syndrome . Methods:Planar and new tomographic gated blood pool scintigraphy were performed in 66 patients with WPW syndrome and 55 healthy subjects , in which 30 patients were examined again after radiofrequency ablation . The abnormal initial contractions in both planar and tomographic phase image were compared with the sites of accessory pathway (ACP) based on ECG and radiofrequency ablation .Results:The phase angle shift in WPW group was significantly different from that in healthy subjects .New tomographic phase analysis can detect the sites of ACP more precisely than planar phase analysis and ECG ( 93.9%, 80.3%, 79.0%, respectively ).The average phase angle shift in WPW group after operation was less than that before operation (P< 0.01 ) .Tomographic phase analysis discovered two mutiple ACPs and latent ACP that can not be found by ECG. Conclusion:The new tomographic phase analysis is a promising method to detect the sites of ACP and can be used to evaluate the efficacy of operation.

Information management system of nuclear medicine (IMSNM) is an important part of modem medical information system.It is used for the scientific management of clinical works,and classification and storage of patient data and examination data (words and images).With the help of IMSNM,standardization,automation and digitization of clinical operation protocols,the scientific and normalized management,the unification of image storage and viewing could be achieved.The IMSNM plays an important role in the health care,education and scientific research.This study mainly describes the design and application of IMSNM.

In view of the characteristics of the computerized system,the key points in the quality assurance (QA) of the computerized system was discussed and summarized combined with the requirements of the GLP laboratory in Europe and America.The validation of computerized system,the control during the use of computerized system,period maintenance and safety protection of computerized system,archives of electronic data was discussed,expecting to provide reference for the management of computerized system in Chinese GLP laboratory which is generally not high currently.The experiences were obtained as follow:Through repeated inspection and review,the problem was found and set as the risk point;a targeted QA inspection plan was made focusing on the risk-based inspection and the QA inspection plan was timely adjusted according to the problems,which ensures the pertinence and validity of the QA inspection.

Polyethylene terephthalate (PET) is a synthetic polymer consisting of ester bond-linked terephthalate and ethylene glycol. Tremendous amounts of PET have been produced and majority of them enters terrestrial and marine environment as wastes, posing serious threats to the global ecosystems. In 2016, a PET hydrolase from a PET-assimilating bacterium Ideonalla sakaiensis was reported and termed as IsPETase. This enzyme outperforms other PET-hydrolyzing enzymes in terms of its PET hydrolytic activity at ambient temperature, thus holds a great promise for PET biodegradation. In order to improve IsPETase activity, we conducted structure-based engineering to modify the putative substrate-binding tunnel. Among the several variants to the N233 residue of IsPETase, we discovered that the substitution of N233 with alanine increases its PET hydrolytic activity, which can be further enhanced when combined with a R280A mutation. We also determined the X-ray crystal structure of the IsPETase N233A variant, which shares nearly identical fold to the WT protein, except for an open end of subsite Ⅱ. We hypothesized that the smaller side chain of N233A variant might lead to an extended subsite Ⅱ for PET binding, which subsequently increases the enzymatic activity. Thus, this study provides new clues for further structure-based engineering of PETase.
Burkholderiales/enzymology* ; Hydrolases/genetics* ; Polyethylene Terephthalates/metabolism* ; Protein Engineering