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

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

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

OBJECTIVE: To determine the effect of tanshinone IIA on the growth and apoptosis in human hepatoma cell line HepG2. METHODS: The human hepatoma cell line HepG2 was treated with tanshinone IIA at various concentrations for 72 h. The inhibition of proliferation was measured by MTT assay and apoptosis-related alterations in morphology measured by cytochemical staining (HT33258). DNA fragmentation was evaluated by agarose gel electrophoresis. Apoptotic rate and cell arrest were quantified by flow cytometry (FCM). RESULTS: Tanshinone IIA inhibited the growth of HepG2 in a time- and dose- dependent manner. The semi-inhibitory concentration (IC50) value after the treatment with tanshinone IIA on HepG2 for 24, 48 and 72 h were 14.7, 7.4, and 3.9 microg/ mL, respectively. After the treatment with 0.5 - 10 microg/mL tanshinone IIA for 72 h, the formation of apoptotic bodies was observed. DNA ladder was shown in agarose gel electrophoresis, in addition to the cells treated by 1.0 microg/mL tanshinone IIA . The apoptotic rates at 0.5, 1.0, 2.0, 5.0, and 10.0 microg/mL for 72 h were 20.32%+/-2.16%, 28.0%+/-2.35%, 33.87%+/-3.43%, 46.73%+/-4.08% and 57.85%+/-3.74%, respectively, which were all significantly higher than those of the control group (P<0.05). CONCLUSION Tanshinone IIA can inhibit the proliferation of human hepatoma cell line HepG2 in a time- and dose- dependent manner, and the mechanism of growth inhibition of human hepatoma cells may be related to the induction of apoptosis.
Abietanes ; Antineoplastic Agents, Phytogenic ; pharmacology ; Apoptosis ; drug effects ; Carcinoma, Hepatocellular ; genetics ; pathology ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; DNA Fragmentation ; drug effects ; Dose-Response Relationship, Drug ; Drugs, Chinese Herbal ; pharmacology ; Flow Cytometry ; Humans ; Liver Neoplasms ; genetics ; pathology ; Microscopy, Fluorescence ; Phenanthrenes ; pharmacology ; Time Factors

OBJECTIVE: To study the effect of dhfr gene overexpression on ethanol-induced abnormal cardiac and vascular development in zebrafish embryos and underlying mechanisms. METHODS: dhfr mRNA was transcribed in vitro and microinjected into zebrafish fertilized eggs to induce the overexpression of dhfr gene, and the efficiency of overexpression was verified. Wild-type zebrafish were divided into a control group, an ethanol group, and an ethanol+dhfr overexpression group (microinjection of 6 nL dhfr mRNA). The embryonic development was observed for each group. The transgenic zebrafish Tg (cmlc2:mcherry) with heart-specific red fluorescence was used to observe atrial and ventricular development. Fluorescence microscopy was performed to observe the development of cardiac outflow tract and blood vessels. Heart rate and ventricular shortening fraction were used to assess cardiac function. Gene probes were constructed, and embryo in situ hybridization and real-time PCR were used to measure the expression of nkx2.5, tbx1, and flk-1 in the embryo. RESULTS: Compared with the ethanol group, the ethanol+dhfr overexpression group had a significant reduction in the percentage of abnormal embryonic development and a significant increase in the percentage of embryonic survival (P<0.05), with significant improvements in the abnormalities of the atrium, ventricle, outflow tract, and blood vessels and cardiac function. Compared with the control group, the ethanol group had significant reductions in the expression of nkx2.5, tbx1, and flk-1 (P<0.05), and compared with the ethanol group, the ethanol+dhfr overexpression group had significant increases in the expression of nkx2.5, tbx1, and flk-1 (P<0.05), which were still lower than their expression in the control group. CONCLUSIONS The overexpression of the dhfr gene can partially improve the abnormal development of embryonic heart and blood vessels induced by ethanol, possibly by upregulating the decreased expression of nkx2.5, tbx1, and flk-1 caused by ethanol.
Animals ; Ethanol ; Gene Expression Regulation, Developmental ; Heart ; Heart Ventricles ; Zebrafish ; Zebrafish Proteins

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 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

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