Whole-body PET/CT scanning is accompanied by substantial radiation dose in clinic. A large proportion of the radiation dose for examination obtained from whole-boby PET/CT is from CT scan. So how to control radiation dose without impairing CT image quality determined by the clinic is particularly important. Anthropomorphic phantom is the best choice for the study of radiation dose and image quality in PET/CT. The article reviews the meaning of anthropomorphic phantom and the study about PET/CT image quality and radiation dose with the phantom, Then analyzes the relationship between image quality of CT in PET/CT and radiation dose in the practical application.

BACKGROUND: Magnetic labeling of stem cells is a recently developed stem cell in vitro labeling technique. Through in conjunction with magnetic resonance imaging (MRI), it can monitor transplanted stem cells in vivo. OBJECTIVE: To identify the method of superparamagnetic iron oxide (SPIO) labeling pig bone marrow mesenchymal stem cells (BMSCs), to investigate the characteristics of stem cells labeled by various SPIO following MRI, and to determine the minimum amount of labeled cells fer MRI. DESIGN, TIME AND SETTING: A control observation was performed at the laboratories of Department of Cardiovascular Surgery, Medical College of Soochow University, and Medical Imaging Centre, First Affiliated Hospital, Soochow University between September 2006 and March 2007. MATERIALS: Fresh porcine iliac bone marrow was collected from Taihu Meishan pigs. SPIO nanometer particles were purchased from Schedng, Germany. Ultramicro SPIO (USPIO) nanoparticles were provided by School of Chemistry and Chemical Engineering, Soochow University. For such particles, crystal nucleus surface was coated with dextran, and following coating, they were named 1#, 2#, 3# for short according to particle size. METHODS: Following isolation, purification, and culture, BMSCs were in vitro labeled by various kinds of SPIO nanoparticles. The labeled cells were subjected to Prussian blue staining and fluorescence microscope observation. The cell growth was observed using MTT method and the growth curve was plotted. For Feridex-labeled cells, 1×106), 5×105, and 1×105 three cell amount groups were set, for unlabeled cells, a 5×105 cell amount group was included, and for 1#, 2#, and 3# SPIO-labeled cells, only 5×105 cell amount group was used. MRI was conduced for measurement of signal intensity of cells labeled by different scanning sequences, followed by statistical analysis. MAIN OUTCOME MEASURES: Detection of SPIO nandparticles-labeled cells by Prussian blue staining; Growth curves of SPIO nanoparticles-labeled cells; Detection of cellular apoptosis by double staining; Determination of signal intensity of cell masses from different Ependoff tubes using MRI with T1WI, T2WI, and fast field echo (FFE) sequences. RESULTS: BMSCs could be labeled with SPIO and the labeling efficiency was 100%. Different amounts of blue-stained Fe particles could be observed in the cytoplasm by Prussian blue staining. SPIO labeling caused a significantly lower signal attenuation effect in T2WI and FFE (T2*WI) images than in T1WI images. In a labeling concentration of 25 mg/L Fe solution, the minimum cell amount for MRI was 1 x 105. The signal intensity exhibited significant difference in 2#, 3#USPIO- and Feridex-labeled cells in no matter T2WI or T2*Wl images(P < 0.01). But no significant difference was found between 1#USPIO- and Feridex-labeled cellss in no mater T2WI or T2*WI images(P > 0.05). There was significant difference in signal intensity of Feridex-labeled BMSCs between T2WI, T2*WI and T1Wl images (P < 0.01). CONCLUSION: BMSCs can be easily and efficiently labeled by SPIO nanoparticles without interference, at proper concentrations on cell viability and proliferation. MRI visualization of SPIO-labeled BMSCs is feasible in both T2WI and T2*WI images.

Objective To explore baccalaureate nursing students' perception of caring, so as to provide evidence for promoting their caring behaviors. Methods Phenomenology was the chosen methodology, 11 baccalaureate nursing students were interviewed in depth. Results Themes of caring were formed into four categories: caring behavior was reciprocal; the motives of caring included fear, concern, responsibility and obligation; knowledge, technical competency and professional helping relationship constituted caring; the confusions of caring came from many factors in clinical practice. Conclusions Baccalaureate nursing students can understand the connotation of caring accurately. To encourage their caring behaviors,clinical supervisors and managers should take all kinds of measures to maintain their faith in caring.

[Objective]To investigate the impact of endplate facture on prognosis of thoracolumbar fracture.[Method]Seventy-three patients with thoracolumbar fractures were treated with transpedicular bone grafting combined with pedicle screw fixation system.Of them,thirty-four cases eligible for the study were divided into groups A and B.Group A:no endplate fracture or minor endplate fracture.Group B:bursting endplate fracture.The height of fractured vertebra and the Cobb angle before and after operation,and at the final follow-up were determined and analysed.[Result]There were no significant differences in Cobb angles and height between growps A and B before operation.After operation,the height of fractured vertebra in group B were lower than that of group A.The Cobb angles had no significant difference between the two groups.The height and Cobb angles between the two groups had significant difference at final follow-up.The improvement in group A was significant higher than in group B.[Conclusion]Endplate bursting facture affects the reduction of fractured vertebra and causes loss of the vertebral height and the corrected angle.

AIM:Cyclin is a decisive factor of regulating cell cycle,and RNA interference as an effective and specific gene silencing technique,can induce cell express the phenotype of specific gene deficiency. This study is to apply cyclinD1 specific small interfering RNA(siRNA) on inhibiting cyclinD1 gene expression and investigate the effect of cyclinD1 specific siRNA on the cell cycle and multiplication in keloid fibroblasts. METHODS:The experiment was conducted at the Institute of Genetic Engineering(Grade BSL-2) in Southern Medical University from July 2006 to May 2007.①siRNA was designed with siRNA target finder of ambion Company,and synthesized chemically in Shanghai GeneChem,Co.,Ltd. Then double-strand siRNA was obtained following degenerative renaturation. Keloid fibroblasts were sampled from the patients in the Department of Plastic Surgery,Southern Medical University(informed consents were obtained from the patients or their relatives).②The keloid fibroblasts were divided into experimental group and control group. The cyclinD1 specific siRNA was transfected into the keloid fibroblast of the experimental group by the liposome-mediated gene transfection method. The untreated cells were set as controls.③At hours 24,48 and 72 of transfection,light microscope was used to observe cell morphologic change and flow cytometry was used to examine cell cycle. The viable cells were counted by MTT colorimetry and a cell growth curve was drawn. RESULTS:①Abnormal change of cell morphology that became into spherical shape or oval-shape from normal long fusiform after transfection may be the apoptosis or necrosis cells.②The G1 stage of cell cycle extended and the S stage decurtated. At 24,48 and 72 hours after transfection,the radio of G1 stage cell was 60.13%,66.22% and 67.53%,which were all significantly higher than that in the control group(54.53%);the radio of S stage cell(18.25%,17.11% and 11.15%) was also significantly lower than that in the control group(22.31%),indicating that the proportion of the cells blocked in G1 stage and those in S stage decreased in the keloid fibroblast.③siRNA-cyclinD1 inhibited the growth of keloid fibroblasts obviously by using MTT assay,and the cell growth curves indicated that the proliferation of cell transfected with cyclinD1 specific siRNA was inhibited significantly when compared with controls. CONCLUSION:CyclinD1 specific siRNA effectively inhibits the expression of cyclinD1 in keloid fibroblasts thus arresting the cell cycle at G1 stage and enhancing cell apoptosis.

Objective To evaluate the safety, efficacy and morbidity of transurethral electrovaporization of superficial bladder tumor (TVBt). Methods TVBt was performed in seventy-three pat iens (mean age 66 years) with superficial bladder carcinoma,twelve of them trans urethral electrovaporization of the prostate (TVP) was carried out simultaneousl y for concomitant BPH. Results The tumor was resected in one-stage for 72 cases,in two-stage for multiple tumors in one patient. The mean operative time was 29 minutes in simple TVBt group, and 78 minutes in the group performing both TVBt and TVP. Intraoperative bladde r perforation occurred in 1 case, No patient need blood transfusion for bleeding . The mean duration of an indwelling urethral catheter was 46h. All patients wer e followed up for twenty-four months, and the recurrence rate was 21% within t wo years after the operation. Conclusions TVBt is a simp le, effective and safe surgery for the treatment of superficial bladder cancer.

Objective To evaluated the surgical techniques and results of open reduction and internal fixation performed for ankle fracture. Methods Eighty-two patients with ankle fracture were treated with open reduction and internal fixation from March 1995 to June 1999. Fifty-eight patients with complete clinical data were analyzed. The patient group consisted of 36 males and 22 females. According to Weber-AO classification, the group was made up of 30 Weber B cases,28 Weber C cases. All patients were evaluated with modified Baird and Jackson scoring system. The relationship between final result and fracture pattern, fixation methods, the time of exercise initiation after operation were analyzed respectively. Results The followed-up period varied from 2 months to 52 months, with an average of 17 months. The number of patients whose results was excellent, good, fair and poor was respectively 31, 18, 6 and 3. The total percentage of good to excellent clinical results was 84.5%. Fifty-four ankles were completely pain free and the remainders had only slight pain after long time walking. Conclusion Operative treatment may provide satisfactory fracture reduction and clinical results for ankle fracture. Correct fracture pattern estimation and proper internal fixation is of importance to achieve and maitain reduction, and then, to gain better long term results.

Objective To introduce a method of comprehension correction for secondary lip-nasal deformities after operation of the completely unilateral cleft lip. Methods The correction consisted of the following procedures: reposition of the columella and nasal alar crus by one tractional suture with nostril base narrowing; modification of flat nostril by a MT-plasty at the edge of naris; arising of the nasal alar and nasal dorsor by ePTFE implantation; reconstruction of the Cupid's bow by M type incision and vermilion advancement; repair of the vermilion deficit with the hinge mucosal flap and bipedicle mucosal flaps of the lower lip. Results Twenty-one cases with secondary lip-nasal deformities were successfully corrected by these comprehensive methods. Ten of them were followed-up for three months to 1 year with satisfactory effects. Conclusion The comprehensive methods can be used to correct satisfactorily the secondary lip-nasal deformities after operation of the completely unilateral cleft lip.

Objective To evaluate endoscopic management of bladder neck obstruction (BNO). Methods 44 patients suffering from BNO have been treated by transurethral resection of bladder neck (TURN). Results All patients have been followed up for 6～84 months with a mean of 48 months.The success rate has been 84%.Recurrence was observed in 4 (11%) for all of which TURN was carried out twice or three times with success.The causes of the 7 failures were neurogenic bladder, detrusor-extra-sphincter dyssynergy, BNO with chronic prostatitis (CP) or BNO with chronic cystitis in female patients. Conclusions Endoscopic management is a safe and efficient treatment for BNO.Careful consideration should be undertaken in case there is CP or for female patients.Postoperative adjunctive hormone supplement therapy and long-period urethral dilatation might be needed for preventing recurrence.

Objective To study the effect of evodiamine(EVO)-stimulated dendritic cells(DC) of spinal cord homogenate protein(hpDC) on repair of spinal cord injury(SCI) in mice.Methods Twenty hours after SCI,mice were randomly divided into 6 groups and injected with PBS,EVO,DC,DC+EVO,hpDC and hpDC+EVO.BMS and histopathology were used to observe the effect of hpDC+EVO on the functional recovery of spinal cord injury and pathological changes such as local scars.Levels of brain-derived neurotrophic factor(BDNF),neurotrophin-3(NT-3),interleukin-12(IL-12) and granulocyte macrophage colony stimulating factor(GM-CSF) in injured sites and supernatant of cultured T cells were measured by ELISA.Results Eighty-four days after treatment,the BMS was significantly higher in hpDC + EVO group than in other groups(P