OBJECTIVE To establish RAPD typing method for Enterobacter aerogenes,and apply RAPD to study molecular epidemiology of E.aerogenes in a neonatal unit.METHODS Five E.aerogenes strains were isolated from four patients in the same neonatal unit at the same time.These strains were typed by RAPD technique.Antibiotic susceptibility was determined by MIC to evaluate drug-resistance.RESULTS Two strains belonging to a unique RAPD-typed ones were epidemiologically related strains.These strains isolated from two patients who hospitalized in the same neonatal unit for four and ten days,respectively.Five E.aerogenes strains were resistant to aminoglycosides,piperacillin and the third-generation cephalosporins in varying degree.CONCLUSIONS RAPD technique is a very easy and reliable molecular tool in the study of E.aerogenes epidemiology.Antibiotic resistance of E.aerogenes is probably related with the history of using antibiotics.

OBJECTIVE: To compare the accuracy of different methods for image registration in image-guided adaptive brachytherapy (IGABT) for cervical cancer. METHODS: The last treatment planning CT images (CT1) and the first treatment planning CT images (CT2) were acquired from 15 patients with cervical cancer and registered with different match image qualities (retained/removed catheter source in images) and different match regions [target only (S Group)/ interested organ structure (M Group)/body (L Group)] in Velocity3.2 software. The dice similarity coefficient (DSC) between the clinical target volumes (CTV) of the CT1 and CT2 images (CTVCT1 and CTVCT2, respectively) and between the organs-at-risk (OAR) of the two imaging datasets (OARCT1 and OARCT2, respectively) were used to evaluate the image registration accuracy. RESULTS: The auto-segmentation volume of the catheter source using Velocity software based on the CT threshold was the closest to the actual volume within the CT value range of 1700-1800 HU. In the retained group, the DSC for the OARs of was better than or equal to that of the removed group, and the DSC value of the rectum was significantly improved ( < 0.05). For comparison of different match regions, the high-risk target volume (HRCTV) and the low-risk target volume (IRCTV) had the best precision for registration of the target area, which was significantly greater than that of M group and L group ( < 0.05). The M group had better registration accuracy of the target area and the best accuracy for the OARs. The DSC values of the bladder and rectum were significantly better than those of the other two groups ( < 0.05). CONCLUSIONS The CT value range of 1700-1800 HU is optimal for automatic image segmentation using Velocity software. Automatic segmentation and shielding the volume of the catheter source can improve the image quality. We recommend the use of interested organ structures regions for image registration in image-guided adaptive brachytherapy for cervical cancer.
Brachytherapy ; methods ; standards ; Female ; Humans ; Organs at Risk ; diagnostic imaging ; Radiotherapy Dosage ; Radiotherapy Planning, Computer-Assisted ; methods ; standards ; Radiotherapy, Image-Guided ; methods ; standards ; Software ; Tomography, X-Ray Computed ; methods ; standards ; Uterine Cervical Neoplasms ; diagnostic imaging ; radiotherapy