Biomechanical behavior of brain injury caused by sticks using finite element model and Hybrid-III testing

Objective: To study the biomechanical mechanism of head injuries beaten with sticks, which is common in the battery or assaultive cases. Methods: In this study, the Hybrid-III anthropomorphic test device and finite element model (FEM) of the total human model for safety (THUMS) head were used to determine the biomechanical response of head while being beaten with different sticks. Total eight Hybrid-III tests and four finite element simulations were conducted. The contact force, resultant acceleration of head center of gravity, intracranial pressure and von Mises stress were calculated to determine the different biomechanical behavior of head with beaten by different sticks. Results: In Hybrid-III tests, the stick in each group demonstrated the similar kinematic behavior under the same loading condition. The peak values of the resultant acceleration for thick iron stick group, thin iron stick group, thick wooden stick group and thin wooden stick group were 203.4 g, 221.1 g, 170.5 g and 122.2 g respectively. In finite element simulations, positive intracranial pressure was initially observed in the frontal comparing with negative intracranial pressure in the contra-coup site. Subsequently the intracranial pressure in the coup site was decreasing toward negative value while the contra-coup intracranial pressure increasing toward positive values. Conclusions: The results illustrated that the stiffer and larger the stick was, the higher the von Mises stress, contact force and intracranial pressure were. We believed that the results in the Hybrid-III tests and THUMS head simulations for brain injury beaten with sticks could be reliable and useful for better understanding the injury mechanism.     

The proapoptotic 9-2 isozyme of 2-5 (A) synthetase cannot substitute for the sperm functions of the proapoptotic protein, Bax.

The 9-2 isozyme of 2-5 (A) synthetase has cellular proapoptotic functions that are mediated not by enzyme activity but by the Bcl-2 homology domain 3 present in its unique carboxyl-terminal region. Another proapoptotic cellular protein is Bax, whose absence in the Bax(-/-) mice causes male sterility due to abnormal sperm differentiation. In this study, we examined whether transgenic 9-2 expression can substitute for the in vivo reproductive function of Bax. To achieve this goal, a sperm-specific promoter was used to drive the expression of 9-2 in the sperm of transgenic mice. By selective cross-breeding, the transgene was transferred to Bax(-/-) mice to generate the experimental mouse line (Bax(-/-), 9-2(+/+)). The male experimental mice were sterile, and their testes maintained the structural abnormality found in Bax(-/-) mice. Thus, the male reproduction functions of Bax could not be replaced by the 9-2 isozyme of 2-5 (A) synthetase.     

Acromioclavicular joint dislocation: a comparative biomechanical study of the palmaris-longus tendon graft reconstruction with other augmentative methods in cadaveric models

Background  

Acromioclavicular injuries are common in sports medicine. Surgical intervention is generally advocated for chronic instability of Rockwood grade III and more severe injuries. Various methods of coracoclavicular ligament reconstruction and augmentation have been described. The objective of this study is to compare the biomechanical properties of a novel palmaris-longus tendon reconstruction with those of the native AC+CC ligaments, the modified Weaver-Dunn reconstruction, the ACJ capsuloligamentous complex repair, screw and clavicle hook plate augmentation.     

Lecithin vesicles for topical delivery of diclofenac.

Skin penetration of topically applied diclofenac is important for the treatment of rheumatic diseases and actinic keratoses. We have studied the permeation of diclofenac across human cadaver epidermis in-vitro from four lecithin vesicle formulations and a few marketed semi-solid preparations. The lecithin vesicle formulations were prepared by dissolving the lipid contents (lecithin and sodium cholate) in a 1:1 mixture of methanol-chloroform, evaporating the solvents under vacuum, and hydrating the lipid layer with the drug solution in water or 10% ethanol. The vesicles were sonicated for 5 min to reduce the vesicle size and their size and Zeta potential were characterized. The cumulative amount and maximum flux of diclofenac was 69.7+/-40.3 micrograms and 4.77+/-3.16 micrograms/hcm(2) from lecithin vesicles containing sodium cholate and 10% ethanol, and is the highest of all formulations studied. The cumulative amount and mean maximum flux obtained from other formulations were in the range of 2.46+/-1.98-29.9+/-10.1 micrograms and 0.53+/-0.46-3.61+/-0.86 micrograms/hcm(2). Based on the results, lecithin vesicles of diclofenac appear to be advantageous for the topical delivery of diclofenac.     

CD14+单核细胞人类白细胞抗原DR表达率与脓毒症关系的研究

目的了解烧伤延迟复苏时CDl4^＋单核细胞人类白细胞抗原DR（HLA—DR）表达率的变化，分析其与脓毒症的关系。方法选择烧伤面积大于30％TBSA的25例烧伤延迟复苏患者，于伤后1、3、7、14、28d取外周血，其中7例患者住院期间并发脓毒症，于脓毒症发生后连续2d亦取其外周血。另取20例健康体检者外周血作为对照。流式细胞仪检测CD14^＋单核细胞HLA．DR表达率，酶联免疫吸附测定法检测血浆中肿瘤坏死因子α（TNF—α）、白细胞介素10（IL-10）的浓度。结果非脓毒症患者伤后1、3、7、14、28dCD14^＋单核细胞HLA—DR表达率分别为（15±6）％、（74±5）％、（264±17）％、（284-16）％、（474-16）％，明显低于健康体检者[（924±10）％，P〈0．01]；脓毒症患者发生脓毒症后1、2d，该指标亦明显低于健康体检者及非脓毒症患者伤后1、7、14、28d（P〈0．01）。脓毒症患者TNF—d检出率及TNF—α、IL-10浓度，均高于非脓毒症患者和健康体检者（P〈0．05或P〈0．01）。伤后1、7、28d，外周血CD14^＋单核细胞HLA—DR表达率与IL—10浓度呈显著负相关（r分别为-0．9963、-0．7459、-0．8474，P〈0．01）。结论烧伤延迟复苏患者免疫功能低下，促炎性介质释放量增加，并发脓毒症时则更为严重。外周血CD14^＋单核细胞HLA—DR表达率可作为动态检测患者免疫功能状态的有效指标。     

Management of progressive exophthalmos

The present study reveals our experience in the medical management of 30 cases of progressive/malignant exophthalmos, employing costicosteroid, b-blocker, diuretic and a preparation containing proteolytic enzymes. There was encouraging improvement in terms of symptoms, proptosis and optic nerve compression, while reduction of ophthalmoplegia was not so satisfactory. However, none of the patients needed decompression surgery.