Development and global validation of a 1-week-old piglet head finite element model for impact simulations / 中华创伤杂志(英文版)

PURPOSE@#Child head injury under impact scenarios (e.g. falls, vehicle crashes, etc.) is an important topic in the field of injury biomechanics. The head of piglet was commonly used as the surrogate to investigate the biomechanical response and mechanisms of pediatric head injuries because of the similar cellular structures and material properties. However, up to date, piglet head models with accurate geometry and material properties, which have been validated by impact experiments, are seldom. We aim to develop such a model for future research.@*METHODS@#In this study, first, the detailed anatomical structures of the piglet head, including the skull, suture, brain, pia mater, dura mater, cerebrospinal fluid, scalp and soft tissue, were constructed based on CT scans. Then, a structured butterfly method was adopted to mesh the complex geometries of the piglet head to generate high-quality elements and each component was assigned corresponding constitutive material models. Finally, the guided drop tower tests were conducted and the force-time histories were ectracted to validate the piglet head finite element model.@*RESULTS@#Simulations were conducted on the developed finite element model under impact conditions and the simulation results were compared with the experimental data from the guided drop tower tests and the published literature. The average peak force and duration of the guide drop tower test were similar to that of the simulation, with an error below 10%. The inaccuracy was below 20%. The average peak force and duration reported in the literature were comparable to those of the simulation, with the exception of the duration for an impact energy of 11 J. The results showed that the model was capable to capture the response of the pig head.@*CONCLUSION@#This study can provide an effective tool for investigating child head injury mechanisms and protection strategies under impact loading conditions.

Nifedipine promotes formation of autophagosomes and enhances expression of Beclinl in hepatoma cell line Huh-7 / 中国药理学通报

Aim To investigate the effect of nifedipine on the formation of autophagosomes in hepatoma cell line Huh-7 and its mechanism.Methods Different concentrations of nifedipine were used to interfere with the proliferation of Huh-7 cells in vitro.The effect of nifedipine on the proliferation of Huh-7 cells was detected by cell proliferation experiment and colony formation experiment.The expressions of Beclin1 and LC3B-Ⅱ were detected by Western blot.The effect of nifedipine on the formation of autophagosomes in Huh-7 cells was observed by laser scanning confocal microscopy.Results Nifedipine significantly inhibited the proliferation of Huh-7 cells in a time-and concentration-dependent manner.The IC50 of nifedipine on day 2 was 22.7 mg·L-1.Nifedipine at the concentration of 25 mg·L-1 significantly reduced the colony formation rate of Huh-7 cells compared with the control group, and the inhibition rate of colony formation was(95.46±0.45)%.Western blot analysis showed that nifedipine significantly up-regulated the protein expression levels of Beclin1 and LC3B-Ⅱ.The amount of autophagosomes in nifedipine group cells were more than that of control group, which was observed by laser scanning confocal microscopy.Conclusions Nifedipine significantly inhibits the proliferation of Huh-7 cells and promotes the formation of autophagosomes, which may be related to the up-regulation of Beclin1 protein expression by nifedipine.

Investigation on the molecular mechanisms of anti-hepatocarcinoma herbs of traditional Chinese medicine by cell cycle microarray / 中国中药杂志

<p><b>OBJECTIVE</b>To design DNA microarray and investigate the molecular anti-tumor mechanism of herbs of traditional Chinese medicine.</p><p><b>METHOD</b>cDNA microarrays consisting of 56 probes representing 24 human cell cycle genes were constructed, Four anti-hepatocarcinoma herbs including Radix Linderae, Hebra Artemisiae Annuae, Radix Amebiae, Radix Astragli, were chosen. Effects of herbs on SMMC-7721 cell cycle were observed by flow cytometry assay. Effects of herbs on cell cycle gene expression in SMMC-7721 cells were analyzed by comparing hybridization of Dig-Labeled cDNAs from herb-treated cells and cDNAs from untreated cells.</p><p><b>RESULT</b>Expressions of cell cycle geneswere changed in different degrees after herbs treated. Some genes were down-regulated and some genes were up-regulated. The changes in gene expression agreed with the results of flow cytometry assay.</p><p><b>CONCLUSION</b>The results suggest that these herbs may have effects on cell cycle and DNA damage checkpoint genes which may be the mechanism of the herbs, and DNA microarray can be used to investigate the biological function of extracts of traditional Chinese medicine.</p>

Detection of differentially expressed genes in hepatocellularcarcinoma cells SMMC-7721 treated with Typhonium giganteum extract by mRNA differential display / 中国中药杂志

<p><b>OBJECTIVE</b>To screen and identify the differentially expressed genes in hepatocellular carcinoma cells SMMC-7721 responsing to the aqueous extract from dried powdered rhizomes of Typhonium giganteum (AEoTGE).</p><p><b>METHOD</b>The response of hepatocellular carcinoma cells SMMC-7721 to AEoTGE was explored with the technique of mRNA differential display.</p><p><b>RESULT</b>After hepatocarcinoma cells SMMC-7721 were treated by AEoTGE for 36 hours, 1 gene expression was upgrade and 1 gene expression was downgrade induced by AEoTGE.</p><p><b>CONCLUSION</b>The research has provided important clues for the molecular mechanism of how hepatocarcinoma cells responseing to T. giganteum.</p>