Résumé
BACKGROUND:The anterior cruciate ligament has unique nonlinear mechanical properties under a complex physiological loading environment.Elastin is an important contributor to the mechanical properties of the anterior cruciate ligament,but its mechanical response to the anterior cruciate ligament under axial tension is not clear. OBJECTIVE:To quantitatively analyze the effect of elastin on the tensile mechanical response of the anterior cruciate ligament. METHODS:Elastase solution and control buffer were prepared.The porcine anterior cruciate ligament samples were prepared into small-size samples and randomly soaked in 0,0.1,1.0,2.0,5.0,and 10.0 U/mL elastase solution for 6 hours,and other small samples of the same size were soaked in 2 U/mL elastase solution for 0,1,3,6,9,and 12 hours.To determine suitable soaking conditions for elastin-targeted enzymes and verify the digestive effect,histological staining was used to compare the effects of enzyme treatment on tissue structure and composition.The ligament samples were randomly divided into elastase-treated group and PBS group,and immersed in 2 U/mL elastase solution and PBS buffer for 6 hours,respectively.A mechanical tensile test was performed before and after immersion. RESULTS AND CONCLUSION:(1)The biochemical results showed that being treated in 2 U/mL elastase solution for 6 hours could reduce the elastin content by 31.1%,and had no significant effect on other mechanical-related components in the tissue.(2)The histological results showed that elastase was able to penetrate the tissue,and the loose degree of tissue increased after treatment.(3)In the mechanical results before and after treatment,the mechanical properties of the PBS group decreased significantly,only the low-tension elastic modulus increased significantly and the initial length increased significantly in the elastase-treated group.(4)The intergroup comparison results showed that there was no significant difference between the two groups in pre-treatment,but the low-tension elastic modulus,initial slopes,saturated slopes,and initial length of the elastase-treated group after treatment were significantly higher than those in the PBS group.(5)These results suggest that elastin degradation significantly affects the biomechanical properties of the anterior cruciate ligament and further complements our understanding of the structure-function relationship of the anterior cruciate ligament.
Résumé
Objective To investigate the effect of wire?reinforced epidural catheters on the success rate of epidural catheterization for labor analgesia. Methods A total of 200 nulliparous parturients who re?ceived labor analgesia voluntarily, of American Society of Anesthesiologists physical status Ⅰ or Ⅱ, aged 20-45 yr, with body mass index<35 kg∕m2, were divided into 2 groups (n=100 each) using a random number table: common catheter group ( group Ⅰ) and reinforced catheter group ( group Ⅱ) . After suc?cessful epidural puncture, the corresponding catheter was inserted inⅠandⅡgroups. The development of difficult insertion, intravascular catheter insertion or paresthesia during insertion was defined as a failure of epidural catheterization. The occurrence of the failure of epidural catheterization was recorded. Results Compared with group Ⅰ, the failure rate of epidural catheterization was significantly decreased in groupⅡ( P<0.05) . Conclusion Wire?reinforced epidural catheters can raise the success rate of epidural catheter?ization for labor analgesia.
Résumé
Objective To investigate the effects of protocadherin 20 (PCDH20) in the spinal cord in the development of bone cancer pain (BCP) in rats.Methods Thirty-six SPF female Sprague-Dawley rats,weighing 180-200 g,were randomly divided into 4 groups (n =9 each):sham operation group (group S),BCP group,lentivirus control group (group LC) and PCDH20 siRNA lentivirus group (group P).Control lentivirus and lentivirus containing PCDH20 siRNA 4 μl were injected into the ipsilateral spinal cord in groups LC and P,respectively.One week later,BCP was induced by injection of Walker 256 breast cancer cells into the upper segment of bone marrow of right tibia.The mechanical paw withdrawal threshold (MWT) was measured at 1 day before injection of lentivirus (T1),1 day before BCP (T2),and 7,14 and 21 days after BCP (T3-5).Three rats in each group were sacrificed after measurement of the MWT at 21 day after BCP and the tibia on the operated side was obtained for examination of invasion of the cancer cells with light microscope.The spinal cord was removed for determination of the expression of PCDH20 and postsynaptic density 95 (PSD95) protein (by Western blot) and mRNA (by RTPCR).Results In groups BCP,LC and P,the cancer cells grew out of the bone and destroyed the cortical bone seriously.Compared with group S,the MWT was significantly decreased at T3-5 in groups BCP,LC and P,the expression of PCDH20 and PSD95 protein and mRNA was up-regulated in groups BCP and LC,and the expression of PCDH20 was up-regulated in group P (P ＜ 0.05).Compared with BCP group,no significant change was found in the MWT and expression of PCDH20 and PSD95 protein and mRNA in group LC (P ＞ 0.05),and the MWT was significantly increased at T4,5 and the expression of PCDH20 and PSD95 protein and mRNA was down-regulated in group P (P ＜ 0.05).Conclusion PCDH20 is involved in the development of BCP through regulating the expression of PSD95 in the spinal cord and adjusting the function of excitatory synapse in rats.
Résumé
Objective To study the relativity analysis of abnormal cervical pathology results in cytology and histology.Methods With retrospective analysis of 31,634 cases of fluid-based thin-layer method(ThinPrep Cytology Test,TCT)of PUMC Hospital from January,2001 to March,2003,which reported in the Bethesda System,we checked the abnormal results and advised different diagnose biopsy of vaginoscopy and/or conization,and got the relativity description of abnormal results in TCT and CINⅢ/CIS results validated by vaginoscopy,match analysis of the CINⅡ～Ⅲ and CINⅢ/CIS results validated by vaginoscopy and conization labeled by the age group,and relativity analysis of abnormal results in TCT and CINⅢ/CIS results validated by vaginoscopy.Results Among 31,634 cases of TCT test,948 cases had confirmed biopsy results validated by vaginoscopy,of which 70 cases were of CINⅡ～Ⅲ,56 cases were of CINⅢ/CIS.The risk ratio(RR)of different abnormal TCT results in predicting CINⅢ/CIS results validated by vaginoscopy is:ASCUS group,14.7(95% confidence interval 8.0～27.0,P=0.00);CINⅠ group,13.9(6.3～30.9,P=0.00);CINⅡ group,44.2(15.5～126.5,P=0.00);CINⅢ group,272.2(161.6～458.6,P=0.00);Cancer group,unmeasured.As noted,there is no significant difference between the RR of ASCUS group and CINⅠ group(P=0.951)in predicting CINⅢ/CIS results.Conclusions Vaginoscopy examination and biopsy could verify histology abnormity of CINⅡ～Ⅲ及CINⅢ/CIS from abnormal results of TCT,and has a good accordance along with biopsy results of conization.There are significantly greater risk of being CINⅢ/CIS validated by vaginoscopy in the abnormal TCT patients,among which ASCUS group and CINⅠ group have the coequal risk.
Résumé
Objective To investigate the expression of vascular endothelial growth factor(VEGF) and Color Doppler flow imaging in human thyroid tumours. Methods 90 cases of thyroid tumours were examined for VEGF expression by means of immunohistochemistry and were examined with color Doppler ultrasound for blood flow. Results The positive rates of VEGF expression were much higher in thyroid carcinomas than that in thyroid adenomas. The difference was significant( P