Biomechanical of lateral atlantoaxial articulation in craniocervical junction malformation:afinite element analysis / 重庆医学

Objective To analyze the biomechanical changes of lateral atlantoaxial articulation by means of three‐dimensional fnite element models of craniocervical junction malformation(CJVM) .Methods CT scan images of 1 patients with CJVM were ob‐tained .The analytical model was constructed by advanced three‐dimension modeling and finite element softwares .A comparison of range of motion difference between the deformity model and normal model ,referring to the experience of clinical observation ,was used to verify the validity of the model .Applying respectively the same loads and boundary conditions on finite element model .The effectiveness was verified by contrastive analysis of the variation in lateral atlantoaxial joint stresses .Results The finite CJVM ele‐ment model with high geometric accuracyand reliable parameter had built .Compared to the results of cadaver test and finite element model based in normal cranio‐cervical junction ,the segment mobility coincides with the actual clinical performance in patients .The stress distribution the lateral junction between atlas and axis of can be reasonably explained the deformation of lateral atlanto‐axial joint structure and its important role in remaining stable between atlantoaxial vertebraeunder different physiological conditions .Con‐clusion The structure of lateral atlantoaxial joint changes in patients of CJVM ,the biomechanical stability for preoperative diagno‐sis and intraoperative treatment operation has a certain value .

Effects of rhodiola crenulata compound on serum corticosterone and myocardial glucocorticoid receptor in rats exposed high sustained positive acceleration / 中国比较医学杂志

Objective To study the effect of rhodiola crenulata compound on serum corticosterone and myocardial glucocorticoid receptor ( GR) in rats exposed high sustained +Gz.Methods Seventy-two healthy SD rats were randomly divided into six groups: blank control group, stress control group, +10 Gz stress group and low, medium, high dose drug group, with twelve rats in each.20 mL/kg menstruum was fed to each rat once per day for 14 days.Low, medium and high dose drug group were fed with rhodiola crenulata compound at doses of 0.75 g/kg, 1.5 g/kg and 3.0 g/kg respectively, the other three groups were fed with equal volume saline.Rats were exposed to high +Gz in 15th day.The concentration of corticosterone in the serum of each group rats was detected with ELISA. Western blot was used to detect the expressions of GR in the myocardium of each group rats .Results The content of corticosterone was significantly elevated in +10Gz stress group, while the expression of GR in the myocardium was markedly declined (P <0.01,P <0.05).However, compound preconditioning could decrease concentration of corticosterone in the serum and enhance the expression of GR in the myocardium from rats after +10 Gz exposure. The corticosterone concentration of medium and high dose drug groups was significantly lower and the level of GR expression in the myocardium was significantly higher than that of +10 Gz stress group ( P <0.05 , P <0.01 ) . Conclusion Rhodiola crenulata compound preconditioning could regulate the concentration of corticosterone in the serum and the level of GR expression in the myocardium of the rats exposed +10 Gz, which may be related with its protective effect on high sustained +Gz-induced injury of myocardium.

Review of positive acceleration exposure-induced myocardial and brain injuries in animals and the mechanisms / 中国比较医学杂志

The prevention of myocardial and brain dysfunction induced by positive acceleration (+Gz) exposure is the focus in the field of aerospace medicine research topic .The characteristics and mechanisms that +Gz exposure caused damages to vital organs such as heart and brain remain to be further elucidated .The research literature about +Gz acceleration exposure-induced heart and brain injuries in experimental animals and its mechanisms at home and abroad was reviewed in this paper .

Relationship of IL-8/-251 gene polymorphisms with incidence of sepsis in patients with severe traumatic injury / 中华创伤杂志

Objective To assess the clinical relevance of polymorphisms at position-251 in the promoter region of IL-8 gene and the incidence of sepsis in patients with severe trauma.Methods A total of 296 patients with severe trauma were included in the prospective cohort study.Incidence of sepsis was decided on the basis of the clinical manifestations and blood culture results.Muhiple organ dysfunction score (MODS) was performed using Marshall' s standard.IL-8/-251 gene polymorphisms were genotyped using restriction fragment length polymorphism polymerase chain reaction (PCR-RFLP).IL-8 plasma level was determined using ELISA method.Results Genotype frequency at IL-8/-251 locus in trauma patients was in accord with Hardy-Weinberg equilibrium (P ＞ 0.05).Sepsis incidence in trauma patients with TT,TA,and AA genotypes at IL-8/-251 locus was 58.1％,49.6％,and 25.0％ respectively.Multiple regression analysis showed inverse correlation between sepsis incidence and quantity of A alleles [OR =0.637,95％ CI (0.421,0.963),P ＜ 0.05].Carriers of AA genotype presented lower MODS score than those of other two genotypes (P ＜ 0.05).IL-8 plasma level presented significant difference among carriers of the three genotypes (P ＜ 0.01) and A alleles were associated with the down-regulation of IL-8 (P ＜ 0.01).Conclusion IL-8/-251T/A polymorphisms are implicated in the development of posttraumatic sepsis and AA genotype is protective against posttraumatic sepsis.

Intervention of Ciliary Neurotrophic Factor on Weightlessness-Induced Muscle Atrophy and Myofiber Phenotype Transition / 航天医学与医学工程

Objective To investigate the intervention of ciliary enurotrophic factors(CNTF)on weightlessness-induced muscle atrophy and its myofiber phenotype transition.Methods Tail-suspended (hindlimb unloading)of adult male Wistar rats were used to create the mode J of weightlessness-induced muscle atrophy.The effect of CNTF treatment on weightlessness-induced muscle atrophy and its myofiber phenotype transition was determined by analyzing the expression changes of MHCI/IIb and p130 or Myf5 with RT-PCR and Western blot.Results CNTF treatment in vivo markedly reversed weightlessness-induced muscle weight IOSS selectively in the slow-twitch muscle soleus.Moreover,during tail suspension,soleus weight loss and myofiber phenotype transition indicated that CNTF treatment could sigificantly attenuate the weight loss and slow to fast myofiber phenotrype transition in soleus compared with control(CNTF untreated and tail suspended).Furthermore,it was showed that the CNTF-induced intervention effect was associated with the protein level upregulation of muscle satellite cell-specific markers,P130 and Myf5.The satellite cell pool in CNTFtreated soleus was increased.Conclusion It iS firstly demonstrated that CNTF can attenuate weightlessness-induced muscle atrophy and its myofiber phenotype transition to be through the increase of satellite cell pool in soleus.

Unsymmetrical Response Features of Left and Right Brain to Signals from Left and Right Visual Fields at Different Cognitive Levels / 航天医学与医学工程

Objective To study the response characteristics of left and right brain to signals from left(LVF) and right(RVF) visual fields during cognitive activity. Method ERPs at 9 locations to LVF and RVF signals were compared in 23 normal subjects in 3 task conditions:looking forward only (VC); making switch response to target signals(T) only(SR); making switch response to T differentially(DR). Result (1)Significant difference in ERPs was found between that induced by LVF and RVF signals on left brain especially at frontal location(F5), which appeared as slow negative deflection induced by T and NT from RVF in SR and DR;(2) Condition-dependent unsymmetrical features between left and right brain were found: the slow potential at F5 was significantly more negative in T and contralateral spatial relation(i.e., left brain for RVF) but more positive in NT and ipsilateral relation than that at F6.Conclusion Signals with psychological meaning in RVF might cause more psychological load as suggested by the results obtained in this study.