Isolation ,cultivation and reproductive activity of human umbilical cord blood mesenchymal stem cells / 中国组织工程研究

BACKGROUND:With increased age,bone marrow mesenchymal stem cells(BMSCs)are influenced with regard to quantity and quality,which will induce great damages to the donors.Many studies have focused on seeking substitute MSC source.In contrast it remains controversial whether umbilical cord blood contains MSCs.OBJECTIVE:To isolate MSCs from human umbilical cord blood,and to detect their biological properties.METHODS:Umbilical cord blood samples were sterilely isolated using Percoll density gradient centrifugation to harvest intermediate layer cells.DMEM medium containing fetal bovine serum,penicillin,streptomycin and L-glutamine was added.Following several adherences and purification,the floating cells were discarded.Thus,many adherent cells with a confluence were collected.When cells were 60% 80% confluent,cells were digested by trypsin for subculture.Cells at passages,1,5 and 9 were obtained and their morphological changes were observed.Cell surface antigens were measured using flow cytometry.Growth curves were drawn,and cell viability was determined utilizing MTT.RESULTS AND CONCLUSION:Isolated umbilical cord blood MSCs presented an even size,showing spindle or star-shape fibroblasts-like cells.Umbilical cord blood MSCs at 1,5,9 passages were greatly positive for CD29,CD105 and CD166,but weakly positive for CD34 and CD45.Following 5 days of incubation,cells entered logarithmic growth phase.The number was decreased at day 9.Population doubling time was(53.5±8.32)hours.Cells grew well.Cells at 1-7 passages showed similar viability(P ＞ 0.05).Till passage 9,cell proliferation viability was decreased,but no significant difference was determined(P ＞0.05).Results verified that MSCs can be successfully isolated from umbilical cord blood in vitro.Cells at passages 1-9 presented a good reproductive activity.

Synergic analysis and dynamics pattern of human normal gait during swing phase / 生物医学工程学杂志

A dynamics model of human lower extremity, which combines musculotendon dynamics and muscle excitation-contraction dynamics, is presented. With this model, a motion process of normal gait during swing phase is numerically analyzed by use of the optimal control theory. The model was verified using experimental kinematics, muscles activation, and electromyographic data. The result showed that the tri-phasic activation pattern and synergistic muscles displayed during a normal gait in swing phase. The pattern consists of three distinct phases, i. e., acceleration during moving initiation, braking the moving segment, and posture control at the final specified position.

The research advances of biomechanics of human knee joint ligaments / 生物医学工程学杂志

Ligaments are the main parts which stabilize the knee joint. How to analog the ligaments in biomechanical model will affect the characteristics of the human knee dynamics and in the computation of the stress in ligaments between two bones. This symposium is aimed at the survey of the simplified method of the ligaments via mechanical parameters, and providing an exact method of constructing model.

Synergic pattern analysis of upper limb grasping movements / 生物医学工程学杂志

In order to discuss the evaluation method of human upper limb movements, the patterns of movement coordination during healthy people prehension have been researched. Eight subjects were asked to perform different reaching-grasping and drinking water from the cup tasks with different indices of difficulty, and the arm movement trajectories and the main muscles group electromyography (EMG) data were collected. To explore the prehension control mechanism, a comparison has been made between the solution of the theoretic calculation and the experimental data. The results show that the topological invariance was observed in the trajectories of different task performance, and the linear relationships between joints covariation were exhibited. Moreover, the different muscles were controlled and combined into units of synergistic muscular group necessary to reach and grasp the goal.

Quantitative gait evaluation using principal component analysis / 生物医学工程学杂志

Evaluation of human gait function is of great significance in clinical medicine and rehabilitation engineering. A quantitative gait evaluation method using principal component analysis was proposed. The evaluation steps included that a series of characteristic index was performed by the gait parameters with a gait detection, and the index was normalized, quantified and summarized by principal component analysis. Then the evaluation results were shown in formulation, figures and tables. The examples showed that this system could evaluate the recovery of the gait by treatment.

Progress in the study on synergetic control principle of human upper extremity and related issues / 生物医学工程学杂志

Human upper extremity is the most complex and flexible executor during the human movement, coordination analysis of the synergetic control principle of human upper extremity is of great significance in trajectory planning and real-time control of anthropopathy robots and intelligent prosthesis system. Most studies have only been performed within the last 10 years. This paper surveys the research in the structure characteristic and redundancy coordination principle of human upper extremity, and the developments of various prospects of anthropopathy robots, intelligent prosthesis, gymnastic science and rehabilitation evaluation are discussed.