The finite element method (FEM) is a mathematical technique using modern computer technology for stress analysis, and has been gradually used in simulating human body structures in the biomechanical field, especially more widely used in the research of thoracolumbar spine traumatology. This paper reviews the establishment of the thoracolumbar spine FEM, the verification of the FEM, and the thoracolumbar spine FEM research status in different fields, and discusses its prospects and values in forensic thoracolumbar traumatology.
Biomechanical Phenomena ; Computer Simulation ; Finite Element Analysis ; Humans ; Lumbar Vertebrae/injuries* ; Models, Theoretical ; Stress, Mechanical ; Thoracic Vertebrae/injuries* ; Traumatology

Reverse transcriptase-PCR experiments suggest that the two clusters of genes potentially involved in the oxidation of reduced sulfur compounds are organized as operons in strain of the acidophilic, chemolithoautotrophic bacterium Acidithiobacillus ferrooxidans ATCC 23270, the two clusters of genes including such the ORF of putative sulfate-thiosulfate-molybdate binding proteins, the ORF of putative thiosulfate: quinone oxidoreductase and the ORF of the rhodanese-like protein (P21). Bioinformatic analyses have predicted the possible promoters sequences and the possible +1 start site of transcription for the doxDA operons.

OBJECTIVETo construct the folic acid deficient model in zebrafish and observe the abnormal cardiac phenotypes, to find the optimal period for supplementing folic acid that can most effectively prevent the heart malformation induced by folic acid deficiency, and to investigate the possible mechanisms by which folic acid deficiency induces malformations of heart.

METHODThe folic acid deficient zebrafish model was constructed by using both the folic acid antagonist methotrexate (MTX) and knocking-down dhfr (dihydrofolate reductase gene). Exogenous tetrahydrofolic acid rescue experiment was performed. Folic acid was given to folic acid deficient groups in different periods. The percent of cardiac malformation, the cardiac phenotypes, the heart rate and the ventricular shortening fraction (VSF) were recorded. The out flow tract (OFT) was observed by using fluorescein micro-angiography. Whole-mount in situ hybridization and real-time PCR were performed to detect vmhc, amhc, tbx5 and nppa expressions.

RESULTAbout (78.00 ± 3.74)% embryos in MTX treated group and (68.00 ± 6.32)% embryos in dhfr knocking-down group had heart malformations, including the abnormal cardiac shapes, the hypogenesis of OFT and the reduced heart rate and VSF. Giving exogenous tetrahydrofolic acid rescued the above abnormalities. Given the folic acid on 8 - 12 hours post-fertilization (hpf), both the MTX treated group (20.20% ± 3.77%) and dhfr knocking-down group (43.40% ± 4.51%) showed the most significantly reduced percent of cardiac malformation and the most obviously improved cardiac development. In folic acid deficient group, the expressions of tbx5 and nppa were reduced while the expressions of vmhc and amhc appeared normal. After being given folic acid to MTX treated group and dhfr knocking-down group, the expressions of tbx5 and nppa were increased.

CONCLUSIONSThe synthesis of tetrahydrofolic acid was decreased in our folic acid deficient model. Giving folic acid in the middle period, which is the early developmental stage, can best prevent the abnormal developments of hearts induced by folic acid deficiency. Folic acid deficiency did not disrupt the differentiations of myosins in ventricle and atrium. The cardiac malformations caused by folic acid deficiency were related with the reduced expressions of tbx5 and nppa.

Animals ; Atrial Natriuretic Factor ; metabolism ; Cell Differentiation ; drug effects ; Folic Acid ; metabolism ; Folic Acid Deficiency ; genetics ; metabolism ; Gene Knockdown Techniques ; Heart ; drug effects ; embryology ; growth & development ; T-Box Domain Proteins ; metabolism ; Zebrafish ; embryology ; genetics

Objective To assess the effects of suction drainage versus nondrainage on the post-operative rehabilitation of patients receiving primary bilateral total knee arthroplasties (TKA).
Methods A prospective study including 40 patients was conducted. These patients were diagnosed with osteoarthritis and underwent primary bilateral TKA between October 2007 and September 2009 with the same operation team. A suction drainage was placed by randomization in only one knee for each patient, while the other knee as self-control. Pain visual analogue scale score, extremity swelling, wound healing, range of motion and incidence of early post-operative complications between the drained and nondrained group were compared statistically.
Results Each patient was followed up for 12 months. Placing drainage did not relieve the pain, extremity swelling, ecchymosis, or reduce the incidence of early complications (all P>0.05).
Conclusions Suction drainage in TKA does not exhibit substantial advantages in promoting post-operative rehabilitation after unsophisticated TKA, compared with nondrainage. On the other hand, it might complicate the surgical operation, and increase the incidence of post-operative hemorrhage and retrograde infection.Thus we do not recommend suction drainage in unsophisticatedTKA.

BACKGROUNDTbx1 is the major candidate gene for DiGeorge syndrome (DGS). Similar to defects observed in DGS patients, the structures disrupted in Tbx1(-/-) animal models are derived from the neural crest cells during development. Although the morphological phenotypes of some Tbx1 knock-down animal models have been well described, analysis of the cardiac performance is limited. Therefore, myocardial performance was explored in Tbx1 morpholino injected zebrafish embryos.

METHODSTo elucidate these issues, Tbx1 specific morpholino was used to reduce the function of Tbx1 in zebrafish. The differentiation of the myocardial cells was observed using whole mount in situ hybridization. Heart rates were observed and recorded under the microscope from 24 to 72 hours post fertilization (hpf). The cardiac performance was analyzed by measuring ventricular shortening fraction and atrial shortening fraction.

RESULTSTbx1 morpholino injected embryos were characterized by defects in the pharyngeal arches, otic vesicle, aortic arches and thymus. In addition, Tbx1 knock down reduced the amount of pharyngeal neural crest cells in zebrafish. Abnormal cardiac morphology was visible in nearly 20% of the Tbx1 morpholino injected embryos. The hearts in these embryos did not loop or loop incompletely. Importantly, cardiac performance and heart rate were reduced in Tbx1 morpholino injected embryos.

CONCLUSIONSTbx1 might play an essential role in the development of pharyngeal neural crest cells in zebrafish. Cardiac performance is impaired by Tbx1 knock down in zebrafish.

Animals ; Branchial Region ; cytology ; drug effects ; Heart ; drug effects ; physiology ; Heart Rate ; drug effects ; In Situ Hybridization ; Myocardium ; cytology ; Neural Crest ; cytology ; drug effects ; Oligonucleotides, Antisense ; pharmacology ; T-Box Domain Proteins ; antagonists & inhibitors ; metabolism ; Thymus Gland ; cytology ; drug effects ; Zebrafish ; embryology ; metabolism ; Zebrafish Proteins ; antagonists & inhibitors ; metabolism

OBJECTIVETo study the effect of methotrexate (MTX), a folic acid antagonist which can lead to folic acid deficient, on the cardiac development and on the expressions of BMP2b and HAS2 in zebrafish.

METHODSThe zebrafish embryos at 6-48 hrs post fertilization (hpf) were treated with various concentrations of MTX (0.5 x 10(-3), 1.0 x 10(-3) and 2.0 x 10(-3) M). At 48 hpf, the percentage of cardiac malformation and heart rate were recorded. The zebrafish embryos at 6-10 hpf treated with 1.5 x 10(-3) M MTX were used as the MTX treatment group. At 24 and 48 hpf the cardiac morphology was observed under a microscope. The expressions of BMP2b and HAS2 in zebrafish were detected by in situ antisense RNA hybridization and real-time PCR.

RESULTS6-12 hpf, the early embryonic developmental stage, was a sensitive period that MTX affected cardiac formation of zebrafish. The retardant cardiac development and the evidently abnormal cardiac morphology was found in the MTX treatment group. The results of in situ antisense RNA hybridization showed that the expressions of BMP2b and HAS2 in the zebrafish heart were reduced in the MTX treatment group at 36 and 48 hpf. The real-time PCR results demonstrated that the BMP2b expression decreased at 12, 24, 36 and 48 hpf, and that the HAS2 expression decreased at 24, 36 and 48 hpf in the treatment group compared with the control group without MTX treatment.

CONCLUSIONSThe inhibition of folic acid function may affect cardiac development of early embryos, resulting in a retardant development and a morphological abnormality of the heart in zebrafish, possibly by down-regulating the expressions of BMP2b and HAS2.

Abnormalities, Drug-Induced ; etiology ; Animals ; Bone Morphogenetic Protein 2 ; Bone Morphogenetic Proteins ; genetics ; Down-Regulation ; Folic Acid Antagonists ; toxicity ; Gene Expression Regulation ; drug effects ; Glucuronosyltransferase ; genetics ; Heart Defects, Congenital ; chemically induced ; Hyaluronan Synthases ; Methotrexate ; toxicity ; Polymerase Chain Reaction ; Zebrafish ; Zebrafish Proteins ; genetics

OBJECTIVETo observe the effect of calcitonin on the pathology of fusion in lumbar posterior/facet spinal fusion in rabbit model.

METHODSThirty-two male New Zealand white rabbits were used to establish spinal fusion model. Sixteen rabbits received calcitonin at a dose of 1 IU x kg(-1) x d(-1) were classified as calcitonin group, and the remaining 16 rabbits as control group. Rabbits were killed 1, 2, 4, and 8 weeks after operations. Haematoxylin-eosin staining was applied to observe the pathological process of spinal fusion. Expression of bone morphogenetic protein-2 (BMP2) was detected by immunohistochemistry.

RESULTSBone resorption and fibrovascular stroma formation were the main histological presentation 1 week after surgery. Two and 4 weeks after surgery, more cartilage formed with varying degrees of mineralization, while less trabeculae could be observed in the phase of active bone formation. No remarked margin was seen between cartilage and bone tissues. Eight weeks after surgery, trabeculae distributed widely. The pathological process of spinal fusion in calcitonin group was faster than in control group. Emery scores showed significant differences at different time points (F = 265.44, P < 0.001). Calcitonin and time had a positively synergistic effect on Emery scores, and calcitonin caused significant difference in terms of Emery scores since the second week (F = 22.43, P < 0.001). Expressions of BMP, were significantly different at different time points (F = 1186.54, P < 0.001). Also, calcitonin and time had a synergistic effect on BMP2 expression (F = 13.14, P < 0. 001).

CONCLUSIONSEndochondral ossification exists in the spinal fusion process and may be the main way of ossification. Calcitonin may stimulate the expression of BMP2 and thus accelerate the process of spinal fusion.

Animals ; Bone Morphogenetic Protein 2 ; Bone Morphogenetic Proteins ; biosynthesis ; genetics ; Calcitonin ; therapeutic use ; Lumbar Vertebrae ; surgery ; Male ; Rabbits ; Random Allocation ; Spinal Diseases ; drug therapy ; metabolism ; surgery ; Spinal Fusion ; Transforming Growth Factor beta ; biosynthesis ; genetics

At present, the objective of cutting and pruning Cistanche deserticola is to harvest in successive years and enhance the harvesting yield and quality of C. deserticola in the process of the artificial cultivating C. deserticola. An experiment was conducted focusing on cutting and pruning C. deserticola in artificial forests of Haloxylon ammodendron drip-irrigated with saline water at the hinter-land of the Taklimakan desert, according to different growth stages and lengths. The results were following: (1) The effect of cutting on C. deserticola was similar to that of pruning, which resulted in three kinds of morphological types, not related to the bloom and size of C. deserticola. (2) The growth forms were diversified after pruning. Among them, there had sprouting new body, died or maintaining life with no sprouting, mildewed on its surface layer, etc. However, some of new bodies were sprouting from the lower part of the old body. The death rate of bloomed C. deserticola was higher than that of the underground, and the death rate of the 40 cm in stubble height for C. deserticola was higher than those with the stubble height of 20 cm and 5 cm. (3) Most of the diameter of living C. deserticola after pruning was increasing, but some of them changed little. (4) The mildew and rot of C. deserticola and the broken of the roots of the H. ammodendron and the fallen of the point of the inoculated when it was dug, which would cause the death of the C. deserticola. On the other, the yield-increasing effect and the economic benefit of the techniques of the pruning of Cistanche would need further research and evaluate. Therefore, the application of this technique needs to be cautious.
Amaranthaceae ; growth & development ; Cistanche ; growth & development ; Forests ; Fruit ; growth & development ; Plant Roots ; growth & development

OBJECTIVETo compare iron bioavailability (Fe BV) from ten selected kinds of Chinese wheat flours in order to provide scientific basis for further human trials and enable plant breeding programs to screen biofortified wheat cultivars.

METHODSAn in vitro digestion/Caco-2 cell model was used to assess Fe BV of ten flour samples from six leading Chinese wheat cultivars and the stability of Fe BV in one cultivar was studied across three growing environments.

RESULTSSignificant differences were observed in both Fe BV and Fe bioavailability per gram of food (Fe BVPG) among cultivars (P<0.01) grown at the same location with the same flour extraction rate. Zhongyou 9507 and Jingdong 8 had Fe BV 37%-54% and Fe BVPG 103%-154% higher than the reference control. In the Anyang environment, Zhongyou 9507 had a higher wheat flour-Fe level and Fe BVPG. Differences in Fe BV were detected in cultivars with different flour extraction rates.

CONCLUSIONZhongyou 9507 and Jingdong 8 were identified as the most promising cultivars for further evaluation of efficacy by using human subjects. The growing environments had no effect on Fe BV, but did have a significant effect on Fe BVPG. Fe bioavailabilities in low-extraction (40%) flours were higher than those in high-extraction (78%) flours.

Biological Availability ; Caco-2 Cells ; China ; Ferritins ; chemistry ; Flour ; analysis ; Genetic Variation ; Humans ; Iron ; chemistry ; pharmacokinetics ; Phosphorus ; chemistry ; Phytic Acid ; chemistry ; Triticum ; chemistry ; genetics

BACKGROUNDFolic acid is very important for embryonic development and dihydrofolate reductase is one of the key enzymes in the process of folic acid performing its biological function. Therefore, the dysfunction of dihydrofolate reductase can inhibit the function of folic acid and finally cause the developmental malformations. In this study, we observed the abnormal cardiac phenotypes in dihydrofolate reductase (DHFR) gene knock-down zebrafish embryos, investigated the effect of DHFR on the expression of heart and neural crest derivatives expressed transcript 2 (HAND2) and explored the possible mechanism of DHFR knock-down inducing zebrafish cardiac malformations.

METHODSMorpholino oligonucleotides were microinjected into fertilized eggs to knock down the functions of DHFR or HAND2. Full length of HAND2 mRNA which was transcribed in vitro was microinjected into fertilized eggs to overexpress HAND2. The cardiac morphologies, the heart rates and the ventricular shortening fraction were observed and recorded under the microscope at 48 hours post fertilization. Whole-mount in situ hybridization and real-time PCR were performed to detect HAND2 expression.

RESULTSDHFR or HAND2 knock-down caused the cardiac malformation in zebrafish. The expression of HAND2 was obviously reduced in DHFR knock-down embryos (P < 0.05). Microinjecting HAND2 mRNA into fertilized eggs can induce HAND2 overexpression. HAND2 overexpression rescued the cardiac malformation phenotypes of DHFR knock-down embryos.

CONCLUSIONSDHFR plays a crucial role in cardiac development. The down-regulation of HAND2 caused by DHFR knock-down is the possible mechanism of DHFR knock-down inducing the cardiac malformation.

Animals ; Basic Helix-Loop-Helix Transcription Factors ; genetics ; physiology ; Female ; Heart ; embryology ; Heart Defects, Congenital ; etiology ; Tetrahydrofolate Dehydrogenase ; genetics ; physiology ; Zebrafish ; Zebrafish Proteins ; genetics ; physiology