As a novel research tool in the field of the spinal biomechanics, the finite element method (FEM) complements and verifies the traditional research methods, which has been attached increasingly greater importance. In this paper, we briefly introduce the achievement made in the field of spinal biomechanics by FEM in the past decade, summarize the physiological and pathological behaviors of various spinal anatomical parts described by FEM, and present the basic view of using FEM to optimize the surgery instrument design.

The role of bracing for adolescent idiopathic scoliosis,which came into application in 1960's,has long been controversial.There are various brace instrument with different reported effectiveness.In this paper,we summarize the research findings and main views in the effectiveness of bracing for adolescent idiopathic scoliosis in the past ten years,and explore the possible causes leading to the different results.Besides,we are trying to point out the research trend,in hope of drawing a scientific conclusion on the effectiveness of bracing treatment in the near future.

Objective To study the relationship between rotational deformity and operational correction rate in scoliosis. MethodsFrom January 2005 to December 2006,44 cases of adolescent idiopathic scoliosis with operational correction were reviewed.Before operation,all the patients were performed MRI scan of the whole spine and the rotation angle of superior and inferior endplate of nine vertebraes with the center of apical vertebrae were measured so that the mechanical torsion angle of vertebrae and disc were calculated,and the rotation compliance of the spine was obtained.In addition,preoperative plain,lateral and bending film of thoracic-lumbar vertebrae were taken to measure the Cobb angle,and the items above were compared with those of post-operation to calculate the scoliosis flexibility and correction rate.Correlation analysis was conducted between the rotation compliance,flexibility and operational correction rate in scoliosis.Results There were significant differences in the mean coronal and sagittal Cobb angle before and after the operation(P

Objective To evaluate the effect of health education in controlling the iodine deficiency diserders(IDD) in order to provide reference data for the further prevention and control. Methods Each village of 3 towns in Congjiang County was selected in 2007, where the health education lasting for 10 months had been implemented in the school students of 3-6 grade and the villagers. The school students of 3-6 grade and 30 housewives in the villagers were investigated for their IDD control knowledge, the salt consuming conditions as well as the sales of both rough and fine salt at a salt retail site in each village before and after the health education was implemented. Results The awareness rate of the knowledge of IDD control in the students and housewives was 91.4% (581/636) and 78.3% (282/360), respectively after intervention, which significantly increased (χ2= 532.044, 326.117, both P < 0.01) compared with the rate of 28.2% (184/652) and 11.4% (41/360) before intervention. The proportion of consuming fine salt was 91.8%(146/159) and 95.6%(86/90), significantly inereased(χ2= 236.623, 135.350, both P < 0.01) compared with 6.1%(10/163) and 7.8% (7/90) found before intervention. The selling proportion of fine salt at the salt retail site in the village was 60.0%(900/1500), significantly increased(χ2= 824.176, P < 0.01) compared with 10.0%(150/1500) before intervention. Conclusions Health education and promotion is solid foundation for effectively controlling IDD, through which the students and villagers are actively and voluntarily involved in the program and hence have formed good living and hygiene habits, thus expected effect has been obtained.

OBJECTIVETo study the phamacokinetics and relative bioavailability of combination Radix Angelicae Sinensis and Cortex Cinnamomi.

METHODThe content of ferulic acid in plasma was determined directly by HPLC after oral administration of Cortex Cinnamomi in combination individually with Radix Angelicae Sinensis. The plasma concentration-time curve were plotted. The main pharmacokinetic parameters and relative bioavailability were obtained.

RESULTThe plasma concentration-time curve of fenalic aclid conformed to one-compartment model. The relative bioavailability of Cortex Cinnamomi combined with Radix Angelicae Sinensis were 226.75%.

CONCLUSIONBy the statistical analysis, Cortex Cinnamomi combined with Radix Angelicae Sinensis can increase the relative bioavailability of ferulic acid.

Angelica sinensis ; chemistry ; Animals ; Biological Availability ; Cinnamomum aromaticum ; chemistry ; Coumaric Acids ; blood ; pharmacokinetics ; Drug Combinations ; Drugs, Chinese Herbal ; isolation & purification ; pharmacokinetics ; Female ; Male ; Mice ; Plant Bark ; chemistry ; Plant Roots ; chemistry ; Plants, Medicinal ; chemistry

OBJECTIVETo investigate the effect of the rib cage on the vertebral axial rotation of adolescent idiopathic scoliosis under axial load condition.

METHODSThree dimensional finite element model of adolescent idiopathic scoliosis included and excluded thoracic cage was built based on the data of computer tomography. The model was imported into the preprocessor of the ANSYS 8.0 software for assigning boundary and loading conditions. Then the axial loading condition was simulated after entering the solution modular. The magnitude and direction of each vertebral axial rotation of the scoliotic spine were read and analyzed in the postprocessor of the ANSYS software.

RESULTSThe rib cage had a significant influence on the axial rotation of the vertebra above the structural curve and had no influence on the axial rotation of the lumbar and sacral vertebra. The effect of the thoracic cage on the axial rotation of the apical vertebra was limited. Under different loading conditions, the apical vertebra of both models rotated in the same direction. The magnitude of the vertebral rotation of both models has no statistical significance.

CONCLUSIONSAdolescent idiopathic scoliosis can lead to the anatomical changes of the vertebra and the thoracic cage. The corresponding changes of biomechanical features of the scoliotic spine and rib cage would occur. The deformed thoracic cage could not maintain the rotation stability as the normal one.

Adolescent ; Biomechanical Phenomena ; Finite Element Analysis ; Humans ; Male ; Ribs ; diagnostic imaging ; pathology ; Rotation ; Scoliosis ; diagnostic imaging ; pathology ; Spine ; diagnostic imaging ; pathology ; Thoracic Wall ; diagnostic imaging ; pathology ; Tomography, X-Ray Computed

·AIM:To investigate and analyse the prevalence and risk factors associated with diabetic retinopathy severity in Qingdao. ·METHODS: This survey consisted of the 2 following parts: 2859 community residents aged >60 years old and 4275 patients with T2DM who were older than 30 years old in Qingdao. Ophthalmic examinations were performed on all patients. A questionnaire was used to obtain the patient's age and gender, the duration of diabetes mellitus(DM), glycaemic control and their knowledge of diabetic retinopathy ( DR ). Blood pressure and haemoglobin levels were recorded. All included patients underwent a comprehensive ophthalmic examination that included a fundus examination and retinal photographs and that assigned a grade for the severity of retinopathy according to the Early Treatment Diabetic Retinopathy Study (ETDRS) severity scale. Patients with severe non-proliferative or proliferative diabetic retinopathy and clinically significant macular edema ( CSME ) required ophthalmic therapy were assigned to the need-treatment group, while the remaining patients with DR were assigned to the need-observation group. Correlation and regression analyses were performed to determine the required-treatment rate and risk factors for DR. Logistic regression models were used to estimate odds ratios (OR) and 95% confidence intervals (CI) after adjustment for age, gender and the duration of diabetes. ·RESULTS: DR was present in 334 (11. 68% ) of the 2859 community residents aged > 60 years old and 1097 (25. 66% ) of the 4275 hospital patients with T2DM, and 48 (14. 81% ) of the residents and 172 ( 15. 68% ) of the hospital patients required ophthalmic therapy. In univariate and multivariate logistic analyses, factors including the age of the patients (51-60 years old: OR, 1. 68; 95% CI, 1. 21-1. 72; 61-70 years old: OR, 1. 55;95% CI, 1. 38-1. 76), the duration of diabetes (11-15 years:OR, 2. 61; 95% CI, 1. 51-4. 72; >15 years: OR, 4. 15; 95% CI, 2. 32-5. 77), glycaemic control (medium: OR, 2. 51;95%CI,1.98-3.92;poor:OR,4.69;95%CI,3.39-6.95), and knowledge of DR ( did not understand: OR, 1. 45;95%CI, 1. 21-1. 95) were significantly associated with the required-treatment rate in DR, while gender, low and advanced age ( 31-50 years old and >70 years old ), duration of disease (<10y), hypertension, and insulin treatment did not. ·CONCLUSION: The prevalence rate and the required-treatment rate in DR in Qingdao are relatively high. Being aged 51-70 years old and having a duration of diabetes>10y, poor glycaemic control and a lack of knowledge of DR were found to be potential risk factors that increased the rate of required ophthalmic therapy in patients with DR. In patients with T2DM who were aged 51-70 years old, we found that focusing on using science and education to strengthen the patients' knowledge of DR, establishing specifications for a community DR screening system, and effectively implementing early intervention in the community of DR - affected individuals were particularly important for preventing and controlling the high DR prevalence and the high rate of DR-associated blindness

This report aims to investigate the dynamical changes of HBcAg18-27 epitope specific cytotoxic T lymphocytes(CTL), alanine aminotransferase (ALT), HBV DNA and HBsAg in peripheral blood of acute hepatitis B patients, and to explore the roles of HBcAg18-27-specific CTLs in virus clearance and liver injury. Acute hepatitis B (AHB) and chronic hepatitis B (CHB) patients were divided into two groups according to results of HLA-A0201. Patients with positive HLA-A0201 were classified into HBcAg-specific CTL group and those with negative HLA-A0201 were referred as control group. The specific CTLs were stained with HLA-A0201 limited HBcAg18-27 epitope MHC-Pentamer and the frequencies of CTLs, T, B, NK and NKT cells were detected by flow cytometry (FCM). The serum ALT, HBV DNA and HBsAg were examined using speed analysis, quantitative PCR and abbott chemiluminescent technology. The frequencies of HBcAg18-27-specific CTLs in AHB patients were higher in the early three weeks as compared to the late three weeks. The apex time of HBV-specific CTL frequencies lagged behind those of HBV DNA, HBsAg and ALT. The loss of HBsAg in patients with high frequencies of HBV-specific CTL was earlier than that in patients with low frequencies (t = 2.018, P value is less than 0.05). In the second week the peak frequencies of CD3+CD8+ cells overlapped with that of HBcAg18-27-specific CTLs and with a positive correlation between (r = 0.420, P value is less than 0.05). During the early stages of AHB, the frequencies of NK and NKT cells were found significantly lower than that of control group and CHB group and the levels were back to normal after recovery. Moreover, a negative correlation existed between the frequencies of NK cells and the dynamic changes of HBcAg18-27-specific CTLs (r = -0.435, P value is less than 0.01) in AHB group. The frequencies of HBcAg18-27-specific CTLs were significantly higher as compared to CHB group in the first three weeks (z = -3.258, -4.04, and -3.259, P value is less than 0.01). The early loss of HBsAg was closely related to the high frequencies of HBcAg18-27 specific CTLs in AHB patients. HBcAg-specific CTL frequencies in peripheral blood could be used to predict clinical outcome after HBV infection. The frequencies of CD8+ T cells can reflect the changes of frequencies of HBcAg-specific CTL during acute HBV infection.
Adolescent ; Adult ; Case-Control Studies ; Female ; HLA-A2 Antigen ; immunology ; Hepatitis B ; immunology ; Hepatitis B Core Antigens ; blood ; immunology ; Humans ; Killer Cells, Natural ; immunology ; Lymphocyte Count ; Male ; Middle Aged ; T-Lymphocytes, Cytotoxic ; cytology ; immunology ; Young Adult

OBJECTIVETo study retrospectively the efficacy and complications of combined pedicle subtraction osteotomy (PSO) and polysegmental closing wedge osteotomy for correction of the severe rigid thoracolumbar kyphotic deformity in ankylosing spondylitis (AS).

METHODSA total of 8 consecutive male patients with AS and severe thoracolumbar kyphotic deformity (mean age 32 years, range 28 - 46) were involved in this study from August 2004 to June 2007. The average preoperative Cobb angle of thoracic spine (T(1)-T(12)) was 96 degrees (range, 80 degrees - 112 degrees ), the mean preoperative angle of lumbar lordosis (L(1)-S(1)) was 10 degrees (5 degrees - 15 degrees ). The mean chin-brow angle was 47 degrees (range, 40 degrees - 58 degrees ). The average gaze angle was 43 degrees (range, 32 degrees - 50 degrees ). After preoperative assessment, single-level PSO was performed in L(3) vertebrae and two-level polysegmental closing wedge osteotomy was performed in thoracolumbar vertebrae (T(12)-L(1), L(1-2)). Radiographic and clinical results and complications were assessed.

RESULTSThe surgical time was (298.1 +/- 20.7) minutes and blood loss during the procedure was (1588.8 +/- 171.6) ml. The follow-up period was (11.5 +/- 7.7) months. The postoperative angle and the amount of correction of the thoracic and lumbar spine were 76.1 degrees +/- 9.6 degrees , 20.3 degrees +/- 1.1 degrees and 48.4 degrees +/- 4.7 degrees , 38.4 degrees +/- 4.7 degrees respectively. The postoperative chin-brow and gaze angle was 16.5 degrees +/- 4.6 degrees and 73.0 degrees +/- 5.2 degrees , respectively. The amount of correction for sagittal balance was (12.3 +/- 1.6) cm. No nerve, vascular injury, stress fracture and coronal decompensation occurred in the patients.

CONCLUSIONSCombined PSO and polysegmental closing wedge osteotomy by posterior approach only is safe and effective for correction of the severe rigid thoracolumbar kyphotic deformity in AS. The visual field is significantly improved after surgery.

Adult ; Follow-Up Studies ; Humans ; Kyphosis ; etiology ; surgery ; Male ; Middle Aged ; Osteotomy ; methods ; Retrospective Studies ; Spondylitis, Ankylosing ; complications ; Treatment Outcome

OBJECTIVETo evaluate the clinical efficacy of low molecular weight heparin (Fraxiparine) in rescuing venous crisis of island skin flap.

METHODSOf the 73 patients with venous crisis of island skin flap, 47 received subcutaneous injection of low-molecular-weight heparin (group I) and 26 were treated with phlebotomy, local compression and topical application of unfractionated heparin solution gauze (group II).

RESULTSThe flap survival ratio was (88.46∓8.64)% in group I and (38.37∓6.53)% in group II (P<0.001). At 0, 2, and 4 h after injection of low-molecular-weight heparin, the activated partial thromboplastin time (APTT) was obviously delayed (24.28∓6.71, 41.35∓7.64 and 32.34∓6.35, respectively, P<0.01), FXa:C level was significantly decreased (152.4∓30.7, 65.8∓24.4 and 83.4∓18.4, respectively, P<0.01), while FIIa:C level underwent no obvious alterations (155.70∓31.61, 143.20∓24.75, and 143.4∓23.35, respectively, P=NS).

CONCLUSIONFraxiparine has good antithrombotic efficacy in rescuing venous crisis of island skin flap without adverse effect on systemic coagulation.

Adolescent ; Adult ; Aged ; Female ; Humans ; Male ; Middle Aged ; Nadroparin ; therapeutic use ; Surgical Flaps ; adverse effects ; Treatment Outcome ; Young Adult