Biomedical subjects

Tongyi Chen

Publications and source records attributed to Tongyi Chen.

7 recordsLinked to original sources

PubMed2006

Neuroma-in-continuity model in rabbits.

The present study presents a model for creation of neuroma-in-continuity in the rabbit, confirmed by histologic study, electrophysiology, and examination of molecular markers. Twelve New Zealand rabbits were used. The lateral fascicule of the peroneal nerve with 15-mm in length was resected. In the intervals from 4 to 6 weeks postoperatively, the histology showed the typical pathologic changes of neuroma by hematoxylin-eosin (HE), Luxol fast blue, and Van-Gieson staining. As compared with the healthy nerve, the motor nerve conduction velocity (MCV) and compound motor action potential (CMAP) were found significantly slowed and reduced. The expression of ciliary neurotrophic factor (CNTF) in nerve and calcitonin gene-related peptide (CGRP) mRNA in L7, S1 dorsal root ganglia were downgraded and upgraded, respectively, with formation of neuroma-in-continuity. These electrophysiologic and molecular markers' expression data can be used as reliable parameters for evaluation of management of the neuroma-in-continuity.

Animals↗

PubMed2006

[Initial detection and analysis of neuro-information from amputee].

By detection and analysis of neuro-information from amputee in experiments, a research on the correlations of three main nerves (median nerve, radial nerve and ulnar nerve), on the patterns for discharging information, and on the mechanics about how neuro-information dominates movements was performed. These researches would contribute to the development of neuroprosthesis.

Adult↗

PubMed2006

[Experimental study on magnesium phosphate cement in fracture treatment].

OBJECTIVE: To investigate the effect of magnesium phosphate cement (MPC) to fix fractures. METHODS: In vitro: fifty-four pairs of fresh pig femoral heads were made 1 cm2 fracture and divided into 6 groups (n=9 pairs ). MPC was used to agglutinate fracture of femoral heads at 100% humidity and at 25 degrees C, 37 degrees C respectively. At 30 minutes, 2 and 24 hours after agglutination, the biomechanical strength was measured. In vivo: the tibia plateau fracture models on both sides of 24 rabbits were made, one side was fixed with "L" shaped plate, and the other side was fixed with MPC. Then the effect of treatment was investigated by macrography, micrography, radiography and the In vitro: the adhesive ability of changes of serum electrolyte levels at 3 days, 3, 6 and 9 weeks after operation. RESULTS: MPC was strong. At 24 hours after MPC agglutination, the average tensile strength was 117.16 +/- 23.29 N/cm2. In vivo: after 6 weeks of fixation, the X-ray results showed that all rabbits' tibia plateau fractures were healed without displacement, and MPC was absorbed gradually. The changes of serum electrolyte levels were very minimal. The macrography observation showed that reduction of fracture were good at 3 days after operation, partial MPC remained in fracture end at 3 weeks, fracture line disappeared at 6 weeks and good remodeling was achieved at 9 weeks after operation in the experimental group. The micrography observation showed that the interface between bone and MPC was distinct at 3 days, MPC was degraded gradually and trabeculae began to grow into MPC at 3 weeks, and almost all MPC was degraded at 6 and 9 weeks of operation. CONCLUSION: MPC is a promising biomaterial, and might potentially be used for fracture treatment.

Animals↗

PubMed2005

[Biomechanical experiment of non-stemmed anatomical total hip prosthesis arthroplasty in vitro].

Biomechanical test in vitro was performed to study the biomechanical characteristics of the femoral component in the non-stemmed anatomical total hip prosthesis (A-Fix) arthroplasty. It mimics two stages, the early stage with cementless and the later stage with cement fixation that imitates bone ingrowth. The results were compared with that of normal proximal femur by normalized coefficient analysis. Translation of femoral head after hip replacement is slightly more than normal. The strain of femoral neck after replacement is lower than that of normal. It changes flatly. The security coefficient in early stage is raised by 13% on the tensile side and by 27.6% on the compressive side of femoral neck; that in later stage is raised by 29.6% and by 22.1% separately. The maximal torsional angle of femoral head is minimal, it is 0.02 times that of normal in early stage and 0.01 times in later stage. It demonstrated that A-Fix arthroplasty has the characteristics of low stress and deformation, high intensity and rigidity, and anti-loosening, thus affording mechanical evidences for its clinical use.

Adult↗

PubMed2005

[Review on the progress of peripheral nervous microelectrode].

OBJECTIVE: To review the progress and application of peripheral nervous microelectrode. METHODS: The recent articles on peripheral nervous microelectrode were extensively reviewed. The classification, the progress of the peripheral nervous microelectrode and its utilizable prospect in the control of electronic prosthesis were summarized. RESULTS: The microelectrodes had favorable functions of selective stimulation and recording. It provided an information transmitting interface between the electric prosthesis and peripheral nerves. CONCLUSION: Peripheral nervous signal is a feasible signal source to control electronic prosthesis.

Artificial Limbs↗

PubMed2005

[An experimental study on repairing bone defect with the biodegradable polycaprolactone material].

OBJECTIVE: To investigate the ability of the biodegradable polycaprolactone (PCL) material to repair bone defect and to evaluate the feasibility of using the PCL as the scaffold in tissue engineering bone. METHODS: The bone defect models of 4. 5 mm x 12 mm were made in the bilateral femoral condyle of 65 New Zealand white rabbits. The PCL cylinder was implanted into the right side of defect (experimental group, n = 60), the high dense hydroxyapatite was implanted into the left side of defect (control group, n = 60), and the incision was sutured without any implants (blank group, n = 5). The samples were harvested and observed by examinations of gross, X-ray, bone density, 99mTc-MDP bone scanning, gamma-display ratio and scanning electron microscope (SEM) after 3, 6, 9 and 12 months of operation. The results were compared between the experimental group and control group. RESULTS: At 3, 6, 9 and 12 months after operation, the gross and X-ray examinations indicated that the bone defect filled with the new bone on the PCL-tissue surface, and no delayed inflammatory reaction appeared. The average bone mineral density was greater in the experimental group than that in the control group, and the difference had statistical significance (P< 0. 05). The results of 99mTc-MDP bone scanning and gamma-display ratio showed that the nuclide uptake was more in the PCL group than that in the control group. The SEM result proved that the new compact bone formed on the PCL migrating surface as the PCL degraded gradually,but the collagen fiber sheath formed around the hydroxyapatite in the control group. CONCLUSION: PCL possesses good biocompatibility and high bone inductive potentiality, it can be used to repair bone defect.

Absorbable Implants↗

PubMed2003

Longitudinally implanted intrafascicular electrodes for stimulating and recording fascicular physioelectrical signals in the sciatic nerve of rabbits.

The purpose of this experiment was to determine the stimulating and recording characters of fascicular physioelectrical signals in the activity of peripheral nerves by longitudinally implanted intrafascicular electrodes (LIFEs) in a rabbit sciatic nerve model, and discuss the future application of LIFEs in functional electrical stimulation (FES) and control of electric arm prosthesis. In methodology, LIFEs were inserted into the fasciculus of the sciatic nerves of rabbits and used as recording electrodes and stimulating electrodes, respectively. Motor-evoked potentials (MEPs), cortical somatosensory-evoked potentials (CSEPs), and electromyography (EMG) were recorded by using a transcranial stimulation system (TCS). LIFEs were found to have stable stimulating and recording characters. The interpeak amplitudes (IPAs) of MEPs ranged from 78-156 microV (mean +/- SD, 102 +/- 23.2 microV). The onset latency (OL) of MEPs ranged from 9.8-11.2 msec (mean +/- SD, 10.8 +/- 0.6 msec). The interpeak amplitudes (IPAs) of CSEPs ranged from 5.8-7.2 microV (mean +/- SD, 6.7 +/- 0.5 microV). The onset latency (OL) of CSEPs ranged from 11.4-14.6 msec (mean +/- SD, 12.8 +/- 1.3 msec). EMGs could be recorded in the gastrocnemius, but could not be recorded in the tibialis anterior muscle. In conclusion, longitudinally implanted intrafascicular electrodes can act as intrafascicular stimulating and recording electrodes with high selective characters. They can provide a new way to study fascicular physioelectrical signals and their function in the activity of peripheral nerves.

Animals↗