BACKGROUND: There are a lot of controversies regarding the choice of short versus long segment pedicle screw fixation for the treatment of isthmic spondylolisthesis and degenerative spondylolisthesis treatment. OBJECTIVE: To investigate clinical efficacy of short versus long segment pedicle screw fixation in treatment of lumbar spondylolisthesis.METHODS: A total of 146 spondylolisthesis patients were included in this study, 36 males and 110 females, aged 22-73 years at a mean of 53 years; disease duration was from 1 to 18 years at a mean of 5 years. These patients were treated with lumbar spinal window-opened decompression or laminectomy decompression, a short or long segment pedicle screw internal fixation, transverse interbody fusion.RESULTS AND CONCLUSION: Among 146 involved patients, 72 cases were treated with four pedicle screw fixation (short segments), while 74 cases with six pedicle screw fixation (long segments). Interbody graft was performed in 101 cases, while intertransverse fusion given in 45 cases. Totally 134 cases were followed up for postoperative 1.5-14 years. According to clinical grading standards of Steffee system, the clinical efficacy was assayed excellent in 74 cases, good in 41 cases, mild in 13 cases and poor in 6 cases, with good rate of 85.8%. 77 cases achieved a complete reduction, including 32 cases using a short segment fixation and 45 cases using a long segment fixation. 69 cases achieved partial reduction, including 40 cases using a short segment fixation and 29 cases using a long segment fixation. Pedicle screws ruptures were found in 13 screws of eight patients undergoing short segment fixation, while no pedicle screw fracture was found in long segment fixation. Choice of short or long segment for the fixation is based on the analysis of spondylolisthesis type, severity, duration of disease, emergence of adjacent segment disc degeneration and instability.

[Objective] To evaluate the clinical value of diagnosing osteoporosis with vertebra bone mineral density(BMD) by measurement with quantitative computed tomography (QCT) . [ Method] BMD in of lumbar vertebrae (L<,1～4>)were measured by QCT in 53 healthy middleaged persons or elderly persons (group A) and 68 osteoporosis patients ( groupB) . [Result] BMD in group A declined obviously as age increasing with significant differences (P<0. 01) . In group B,all 68 patients showed osteoporosis according to the diagnostic standard of BMD≤x -2. OSD. Sixty patients showed osteoporosis ifthe diagnostic standard was set to BMD ≤ x -2. 5SD. The BMD values of different age group was lower than the bone quantityblock values. [Conclusion] As a method for diagnosing osteoporosis, QCT has advantages of high sensitation, being precise,being reproducible and is easy for applying. It would be more practical and could decrease mis - diagnosing if the diagnosticstandard was BMD≤x-2.OSD.

Objective To study the risk factors of Pseudomonas aeruginosa (PA)infection and homology of PA isolated from nasopharyngeal carcinoma patients undergoing radiotherapy,and prevent and control the spread of in-fection.Methods Bacteria isolated from clinical specimens were identified by BD Phoenix automated microbiology system. Gene homology were analyzed with randomly amplified polymorphic DNA (RAPD)technique.Results Forty-nine strains of PA were mainly isolated from 43 nasopharyngeal carcinoma patients,the major specimens were nasopharyngeal swab (46.94% ),sputum(32.65% ),and oral secretion (10.20% ).All these strains were amplified 46 electrophore-sis diagrams,and 19 genotypes were identified. The highly homologous genotypes of type H and J strains were mainly isolated from patients in the second section (57.14% ,4/7)and fourth section (60.00% ,3/5)of radiotherapy department respectively. Conclusion Localized epidemic of highly homologous PA exists in different sections of ward,transfer of patients between different sections is the risk factor for homology PA infection/colonization. Gen-otyping technique such as RAPD for analyzing the homology of pathogenic bacteria in healthcare-associated infection has important value in preventing and control Ling infection spread.

Objective To explore a reasonable and secure anesthesia induction in painless induced abortion.Methods 120 patients of painless induced abortion were randomly divided into six groups,control group was injected with Propofol 3.5mg/kg through vein,besides given Propofol 3.5mg/kg,other 5 groups were injected with ketamine 0.1mg/kg、0.2mg/kg、0.3mg/kg、0.4mg/kg、0.5mg/kg through vein respectively.The parameter of hemodynamics,effect of analgesia,time of unconsciousness,recovery time of consciousness,recovery time of orientation,incidence of respiratory depression,side effect,time of discharge from hospital were observed.Results The recorded time and incidence of side effect have statistical significance between group of ketamine 0.5mg/kg and group of ketamine 0.3mg/ks(P<0.05);effect of analgesia have statistical significance between group of ketamine 0.3mg/kg、0.4mg/kg、0.5mg/kg and control group.Conclusion Ketamine 0.3mg/kg combined with Propofol is an ideal choice of painless induced abortion.