Objectives Research into effect on PBL model in prosthodontics education.Methods The PBL model was performed in education of a part of prosthodontics,and education effect was evaluated by table analysis.Results PBL model is proved to be better than the multimedia education model in the training of students'self-study ability,learning initiative,problem-analyzing and problem-solving competence,and the team spirit etc.Conclution Comparaed with the multimedia education model,PBL model is of significance in some respects.

Objective: To study the effect of NOR1 gene on expression of E-selectin in HepG2 cells. Methods: NOR1 gene was transfected into human liver cancer HepG2 cells mediated by cationic lipofectamine. The total RNA was extracted. The mRNA expressions of NORI gene and E-selectin in HepG2 cells were detected by reverse transcription polymerase chain reaction (RT-PCR). The level of E-selectin protein in the supernatant of cell culture was determined by ELJSA method. Results:The results of RT-PCR showed that the mRNA expression of E-selectin in NOR1 gene transfection group was significantly higher than those in blank group and control group (P<0.01). The results of ELISA showed that the protein level of E-selectin in the supernatant of cell culture was significantly higher in NOR1 gene transfection group than those in the blank group and control group (P<0.01). Conclusion: NOR1 gene could induce the increase in E-selectin expression in HepG2 cells.

Objective To investigate the expression of HPV-DNA and p16,Ki-67 proteins in intraepithelial lesion of cervix (CIN) so as to provide the aluable evidence for the early clinical diagnosis and genetic therapy of the CIN.Methods Hybrid capture2 was used to detect HPV DNA in 35 cases of CIN Ⅰ,44 cases of CIN Ⅱ,and 20 cases of CIN Ⅲ.Immunohistochemical MaxVision was used to research the expression of p16 and Ki-67 protein in CIN Ⅰ,CIN Ⅱ and CIN Ⅲ.The results were analyzed with clinicopathological factors.Results Positive expression rates of HPV-DNA were 31.4 ％ (11/35),63.6 ％ (28/44),85.0 ％ (17/20) in CIN Ⅰ,CIN Ⅱ and CIN Ⅲ,respectively.The expression rates of p16 in the three groups were 65.7 ％ (23/35),97.7 ％ (43/44),100.0 ％ (20/20),there were statistically significant difference (x2 =21.30,P =0.00).The expression rates of Ki-67 in the three groups were 77.1％ (27/35),79.5 ％ (35/44),95.0 ％ (19/20),there were no difference (x2 =3.00,P =0.22).Conclusions HPV infection is closely related to the occurrence and development of CIN.p16,Ki-67 can be used as objective marks in diagnosis of CIN.

BACKGROUND: Researches on the diagnosis and detection methods of diabetic autonomic neuropathy(DAN) is very weak at present.OBJECTIVE: To get the data about the degree of autonomic neuropathy by using the nonlinear heart rate variability(HRV) so as to provide clinical evidence for the early diagnosis of DAN.DESIGN: A single sample study.SETTINGS: Computer department in a university; Staff room of medical physics of department of biomedical engineering in a university.PARTICIPANTS: The experiment was completed in the Staff Room of Medical Physics, Department of Biomedical Engineering in the First Military Medical University of Chinese PLA from March to May 2002. Thirty-four diabetic patients, including 22 with DAN complications, were selected from the inpatients of Department of Endocrinology in the Affiliated Nanfang Hospital of the First Military Medical University of PLA, and other 40 normal subjects, who were from the faculty in the First Military Medical University of Chinese PLA and students in the Department of Physical Education, Chinese PLA Institute of Physical Education, were taken as the controls. The R wave to R wave intervals(RRI) time series is sampled and corrected to 512 points for analysis.INTERVENTIONS: Based on the virtual instrumental workbench-LabVIEW, 74 standard adjacent RRI signals were selected from 34 diabetic patients and 40 normal cases, and then analyzed with the method of nonlinear predictability.MAIN OUTCOME MEASURES: Collective and analytical results of the 74 standard adjacent RRI signals.RESULTS: There was no significant difference between the diabetic patients without DAN and the controls by the analysis with normalized mean square error(NMSE) NMSE ( P = 0. 075 ), but the significant difference between the DAN patients and the controls( P = 0. 001) . While significant analysis between the diabetic patients without DAN complications and the controls was significant by the analysis of mean absolute error(MAE) (P = 0. 007 and P = 0. 000), there was also significant difference between the diabetic patients with and without DAN ( P = 0. 001 ).CONCLUSION: Different impaired degree of autonomic nerve system in diabetic patients can result in nonlinear reduction in HRV analysis, but nonlinear predictability analysis can prove the nonlinear model of HRV,. and can also provide important state information of sympathetic and parasympathetic systems so that it can provide reliable evidence for the earlier diagnosis and the prognosis evaluation of DAN.

Objective To investigate the expression level of cyclooxygenase-2 (COX-2) and its effects on cell proliferation activity and apoptosis in colorectal carcinoma. Methods The expression of COX-2, proliferating cell nuclear antigen (PCNA) and apoptosis in 60 cases of colorectal carcinoma, 20 cases of colorectal adenoma and 20 cases of normal mucous were studied by the immunohistochemical and TUNEL methods, the apoptosis index(AI)and proliferation index(PI) were defined respectively. Results The positive expression rate of COX-2 in colorectal carcinoma was significantly higher than that in the other groups. Overexpression of COX-2 in colorectal carcinoma was related to its lymph node metastasis and the size of tumor and clinical stages. In the group with COX-2 positive expression, PI was higher than that in the group with COX-2 negative expression; whereas AI was higher in the latter group than in the former group. Conclusions The expression level of COX-2 may have a close correlation with cell proliferation and apoptosis, they may participate in oncogenesis and progression of colorectal carcinoma.

BACKGROUND:Hydrothermal condition of oral environment has an effect on the mechanical properties of dental core materials.
OBJECTIVE:To evaluate effect of water storage on the weight change rates and flexural properties of three dual-cure core buildup composite resins.
METHODS: Rectangular specimens (25 mm×2 mm×2 mm) were prepared from three dual-cure core buildup composite resins (LuxaCore Smartmix Dual, Para core and Clearfil DC Core). Specimens were stored in distiled water at 37℃ for 0, 1 day, 1, 2, 3 weeks and 1 month, respectively, weighted and then subjected to three-point bending test in a universal testing machine.
RESULTS AND CONCLUSION: Weight change rates of the three composite resins increased with immersion time; at the same immersion time, weight change rates of three composite resins ranked as the folowing order: LuxaCore Smartmix Dual > ParaCore > Clearfil DC Core. The flexural strength of LuxaCore Smartmix Dual decreased with immersion time. The flexural strength of ParaCore showed no significant change during 3 weeks immersion (P > 0.05), while it showed a significant decreasing after 1 month immersion (P < 0.05). There was no significant change on the flexural strength of Clearfil DC Core in the whole immersion process(P > 0.05). The flexural modulus of LuxaCore Smartmix Dual showed a decreased trend in the whole immersion process, but it showed that there was no significant change during the first 2 weeks(P > 0.05), while a significant decrease occurred after 3 weeks and 1 month (P < 0.05). Compared with original specimens, the flexural modulus of ParaCore and Clearfil DC Core showed a decreased trend, but this change was not significant (P > 0.05); the flexural properties of three composite resins showed a fluctuant decreased trend along with weight changes increased. To sum up, Clearfil DC Core showed the best water resistance among three composite resins.

Objective To observe and scale knee joint space of the patients who suffered adults' Kaschin-Beck disease (KBD) in Shangzhi City of Heilongjiang Province in order to acquire basic knowledge for upcoming intervention trial. Methods Clinical test was proceeded in adults aged above 40 in Guanghui Village of Shangzhi City in 2007. In typical patients, bilateral knee X-ray was taken and knee joint space was scaled. Three points were chosen on inner and outer epicondyle of each knee and results were recorded. Results There were 307 peoples over the age of 40 in the village. Two hundred eighty-two accepted clinical test, in a rate of 91.9%. Eighty out of 282 suffered KBD, accounting for 28.4%. When the patients' condition became more serious, measurements from flank, middle, inside points on outer epicondyle of joint space presented a narrowing trend [degree Ⅰ: (5.85±0.17), (4.84±0.17), (4.36±0.18)mm; degree Ⅱ: (5.11±0.43), (4.24±0.34), (3.48±0.28)nun; degree Ⅲ: (3.59± 0.78), (3.10±0.56), (2.14±0.62)mm; Fflank,middle,inside= 6.547,5.372,10.302, all P < 0.05], but those on inner epicondyle of joint space did not[degree Ⅰ:(3.66±0.17), (3.47±0.17), (3.73±0.18)mm; degree Ⅱ:(3.55± 0.34), (3.54±0.29), (4.35±0.35)mm; degree Ⅲ: (3.19±0.72), (3.92±0.66), (4.51±0.72)ram; Finside,middle,flank= 0.351,0.356,1.883, all P > 0.05]. Joint space < 5.00 mm were found in 618, among which 363 were measured on inner epieondyle, obviously greater than those measured on outer epicondyle of joint space(255), the difference being statistically signifieant(χ2=9.59, P<0.05). Conclusions Adult cases of KBD occur in Guanghui Village. Knee joint space of adult patients narrows obviously, the more serious, the narrower, especially occurring more obviously on outer epicondyle, but frequently on inner epicondyle.

Objective: To study the feasibility of the determination paracetamol in Gangmaoqing by HPLC. Methods: The paracetamol contents of the different samples of Ganmaoqing Tablets were determined by the dead stop titration and HPLC, respectively. Results: The dead stop titration was complex and the error was larger. Whereas HPLC was simple, quick with a good seperation and small error.Conclusion: HPLC is accurate and reliable and reproducible for the determination of paracetamol in Ganmaoqing Tablets.

Objective To know the levels of polychlorinated dibenzo-p-dioxins(PCDDs),polychlorinated dibenzo-p-furan (PCDFs)and polychlorinated biphenyl(PCBs)in milk and milk powder.Methods From Feb.2007 to Jun.2007,the milk and milk powder samples were collected and PCDDs,PCDFs and PCBs were extracted from the samples by Soxhlet extraction,cleaned up by FMS and quantified by HRGC-HRMS,using isotope dilution methodology.Results PCDDrFs and PCBs were detected in all samples.The mean levels of PCDD/Fs and dl-PCBs TEQ in the milk powder were 0.43 pg/g lipid(median:0.34 pg/g lipid),and in the packed milk were 3.83pg/g)lipid(median:2.04 pg/g lipid).The mean levels of PCDD/Fs and dl-PCBs TEQ in all samples were 2.13 pg/g lipid(median:0.815 pg/g lipid).The levels of PCDD/Fs and dioxin-like PCBs in the detected samples were far below the limitation of EU except of two milk samples,and the levels of PCDD/Fs and dioxin-like PCBs were higher in the packed milk than those in the milk powder.Conclusion Some of the milk and milk powder in the investigated city has been polluted by polychlorinated dibenzo-p-dioxins(PCDDs),polychlorinated dibenzo-p-furan(PCDFs)and polychlorinated biphenyl(PCBs).

BACKGROUND:Morphological characteristics of the rabbit lumbar vertebrae are of great significance for animal experiments about lumbar spine, but there is a lack of study on the lumbar morphology in rabbits. OBJECTIVE:To establish a three-dimensional model of rabbit lumbar vertebrae, and to observe its morphological characteristics, thereby providing anatomical basis for the animal experiments about lumbar spine.METHODS:Twenty New Zealand rabbits were subjected to 64-row multi-detector CT (Siemens) scan, and the three-dimensional models were constructed based on the CT data from 140 lumbar vertebrae. The morphological parameters of L1-7 were measured, and the internal and external structures of lumbar vertebrae and changes of different segments were observed. RESULTS AND CONCLUSION:(1) Changes of the morphological parameters of each lumbar vertebra:the L1-7 height first increased and then decreased, and the shortest height was in the L7, which was (1.12±0.18) cm. L1 vertebral body exhibited the shortest transverse diameter, (1.03±0.15) cm, and the longitudinal diameter did not differ significantly among vertebrae. The transverse and longitudinal diameters of L1-6 spinal canals were on a rise, but decreased abruptly at L7. The pedicle width of L1-7 increased gradually;the pedicle height of L1-5 increased gradually, and then began to decrease markedly, and the shortest at L7, (0.58±0.11) cm. The width and length of L1-6 spinous process increased steadily, but decreased at L7. The length of L1-3 transverse process increased gradually, tended to be steady at L3-6, and increased notably at L6-7;there were significant differences in the transverse process angle at L1-6, but the angle increased markedly to (58±2)° at L7, (2) These results indicate that the internal and external structures of lumbar vertebrae and changes of different segments are obtained through morphological measurement of lumbar vertebrae in New Zealand white rabbit, which provides a detailed anatomical data for relative animal experiments.