BACKGROUND:The finite element model has been developed from two-dimensional model to three-dimensional model, from linear model to nonlinear model. As the advantage of this method in the analysis of mechanical characteristics of the irregular objects, the finite element model has been widely used in the research of orthopedic biomechanics, especial y in the research of hip joint. OBJECTIVE:To analyze the stress state of human femur with finite element analysis method and to investigate a method that can rapidly construct femoral finite element model and precisely analyze the biomechanics. METHODS:Normal male femur was used as specimen for CT scan to obtain cross-sectional images of femur in each slice. Three-dimensional reconstruction was performed with DICOM data and MIMICS software, then the femoral three-dimensional finite element model was established with the finite element analysis ABQUS 6.8 software, and the stress distribution of the model was analyzed under loading condition. RESULTS AND CONCLUSION:Based on DICOM data, three-dimensional finite element model of femur was constructed more quickly and precisely. The models were divided into 38 636 nodes and 201 422 units. The model included the parts of cortical and cancel ous bone. The biomechanical test results were accorded with the previous results, so the model could objectively reflect the real femur shape and biomechanical behavior with high precision. The Mimics software provided a simpler and effective method for the construction of femur model and improved the efficiency of modeling, and the three-dimensional finite element model based on DICOM data was accurate in shape and can be used for the normal research on biomechanical behavior of femur. The stress distribution analyzed with ABQUS 6.8 software is consistent with the clinical observation.

Tooth agenesis constitutes one of the most common developmental anomalies in man. Oligodontia is defined as congenital absence of six or more teeth. Based on the studies of our team in cooperation with Peking University Center for Human Disease Genomics in the past five years, this article reviews the current research progress in clinical phenotypes and case collection, epidemiological investigation and etiological genetic studies of oligodontia. The symptoms of oligodontia were classified into syndromic and non-syndromic according to the occurrence of tooth agenesis with or without systemic developmental defects. As for the advancement of theories and techniques of molecular genetics, a number of gene mutations have been identified to be the direct etiological factors causing some specified diseases, especially those with developmental defects. Here, this article summarized the outcomes of molecular genetic study of some cases we collected. Of the systemic oligondontia patients, a new four-base-deletion mutation in PITX2 was identified in a large kindred with typical symptoms of Rieger Syndrome; four different gene mutations in ED1 casing X-linked hypohidrotic ectodermal displasia were found in five nucleus families. Compared with the former, non-syndromic oligodontia has more genetic heterogeneity rather than some specific virulence gene. PAX9 and MSX1 are the identified genes associated with family tooth agenesis without systemic syndrome. Also, in our research, three gene mutations in CBFA1 were detected in four cleidocranial dysplasia families, which is a systemic developmental disease including the symptoms of tooth eruption abnormality and accessory teeth.

In order to identify the differentially expressing gene of bone marrow mesenchymal stem cells (MSCs) stimulated by electromagnetic field (EMF) with osteogenesis microarray analysis, the bone marrow MSCs of SD rats were isolated and cultured in vitro. The third-passage cells were stimulated by EMFs and total RNA was extracted, purified and then used for the synthesis of cDNA and cRNA. The cRNA of stimulated group and the control group was hybridized with the rat oligo osteogenesis microarray respectively. The hybridization signals were acquired by using X-ray film after chemiluminescent detection and the data obtained were analyzed by employing the web-based completely integrated GEArray Expression Analysis Suite. RT-PCR was used to identify the target genes: Bmp1, Bmp7, Egf and Egfr. The results showed that 19 differentially expressing genes were found between the stimulated group and the control group. There were 6 up-regulated genes and 13 down-regulated genes in the stimulated group. Semi-quantitative RT-PCR confirmed that the expressions of Bmp1, Bmp7 mRNA of the stimulated group were up-regulated (P<0.05) and those of Egf, Egfr were down-regulated (P<0.05). It was suggested that the gene expression profiles of osteogenesis of the bone marrow MSCs were changed after EMF treatment. It is concluded that the genes are involved in skeletal development, bone mineral metabolism, cell growth and differentiation, cell adhesion etc.
Bone Marrow Cells/*cytology ; Cell Differentiation ; Down-Regulation ; Electromagnetic Fields ; Gene Expression Profiling ; Gene Expression Regulation ; Mesenchymal Stem Cells/*cytology ; Nucleic Acid Hybridization ; Oligonucleotide Probes/chemistry ; Osteogenesis/*genetics ; RNA, Complementary/metabolism ; Reverse Transcriptase Polymerase Chain Reaction

Animals ; Asthma ; drug therapy ; metabolism ; Genistein ; pharmacology ; therapeutic use ; Guinea Pigs ; Interleukin-4 ; genetics ; metabolism ; Janus Kinase 1 ; genetics ; metabolism ; Lung ; metabolism ; Male ; Protein Kinase Inhibitors ; pharmacology ; therapeutic use

Objective To study the methods and outcome of 71 patients with Parkinson's disease treated with microelectrode-guided stereotactic pallidotomy and thalamotomy. Method Pallidal and thalamal target sites are chosen by supervision of microelectrode recording technique in 71 patients with Parkinson's disease. The UPDRS motor score was used to evaluate the outcomes 12 weeks before and after operation Result After 12 months follow-up, tremor disappeared completely or nearly completely in 12 patients who underwent unilateral and l bilateral ventrolateral thalamotomy. Dramatic improvement of tremor, rigidity, bradykinesia were observed in 57 patients underwent posteroventral pallidotomy,including 6 underwent bilateral posteroventral pallidotomy. Intracerebral hemorrhage was observed in l patient. Conclusion Microelectrode-guided stereotactic pallidotomy and thalamotomy are effective in treatmenting Parkinson's disease, but with serious complications

Adolescent ; Cardiomyopathy, Dilated ; diagnosis ; etiology ; physiopathology ; Diagnosis, Differential ; Female ; Graves Disease ; complications ; diagnosis ; physiopathology ; Humans

Objective To analyze the clinical characteristics of Klebsiella pneumoniae infection in preterm infants. Methods Clinical data of 75 preterm infants infected with Klebsiella pneumoniae treated in BaYi Children's Hospital from February 6,2008 to February 10,2010 were retrospectively analyzed.The difference of auxiliary examination between early-onset and late-onset infection group were compared by two independent samples t test.Spearman correlation analysis and non-conditional Logistic regression analysis were used to analyze the high risk factors and the prognostic factors of Klebsiella pneumoniae infection in preterm infants. Results The incidence of Klebsiella pneumoniae infection was 2.8％ (75/2721) in preterm infants,and the mortality rate was 9.3％ (7/75). There were 71 cases of Klebsiella pneumoniae sepsis and 4 cases of Klebsiella pneumoniae pneumonia.Among 75 cases,63 cases were early-onset infection (onset age≤72 h) and 12 were late-onset infection (onset age＞72 h).All patients presented with poor response,heart rate during quiet sleep ＞ 160/min and low oxygen saturation.The mean corpuscular volume and mean corpuscular hemoglobin concentration in early-onset Klebsiella pneunoniae infection cases were higher than those in late-onset neonates [(128.87±24.60) fl vs (113.72±13.54) fl,t=-2.07,P＜0.05and (38.11±2.15) pg vs (36.98±1.05) pg,t=-2.76,P＜0.05].Low birth weight and caesarean section were associated with early-onset Klebsiella pneumoniae sepsis (r=0.250 and -0.240,P＜0.05). The prognosis of Klebsiella pneumoniae infection was associated with hospital stay and duration of premature rupture of membranes (r=0.368 and 0.318,P＜0.05). Conclusions There were no specific clinical manifestations for Klebsiella pneumoniae infection in preterm infants.Preterm infants with low birth weight,long duration of premature rupture of membranes,delivered by caesarean section and received invasive operation are likely to develop Klebsiella pneumoniae infection.

How does brain select and adjust the distributed neural activities to achieve its function? To address this problem,researchers introduce Granger causality analysis method to brain functional study,which deals with the estimation of causal influences among multi-variables.First,basic principles of Granger Causality and its improved algorithm structural vector autoregression (SVAR) are introduced.Then several technical problems are reviewed which should be noted when analyzing brain functional signals by Granger Causality Methods.In the end,the application foreground of Granger Causality in epilepsy localization is introduced by taking idiopathic generalized epilepsy as the example.

0.05). Estrogen was lower in the patients with AD than in the normal controls and there was a significant difference between the two groups (P

OBJECTIVE:To establish the HPLC fingerprint for Blumea balsamifera and its fake B. riparia. METHODS:HPLC was performed on the column of Uitimate-C18 with mobile phase of acetonitrile-0.05% phosphoric acid(gradient elution)at a flow rate of 0.6 mL/min,detection wavelength was 270 nm,column temperature was 25 ℃,and injection volume was 7 μL. Using quercetin as a reference,Similarity Evaluation Software for Chromatographic Fingerprint of Traditional Chinese Medicine(2004 A edition)was used for the common peaks identification and similarity analysis of 16 batches of B. balsamifera and 5 batches of B. ri-paria. RESULTS:There were 61 common peaks in the 16 batches of B. balsamifera,similarity degree was 0.931-0.995,which was higher than the similarity degree of 5 batches of B. riparia. CONCLUSIONS:The established fingerprint can provide reference for the identification and quality evaluation of B. balsamifera.