Biomedical subjects

An-min Jin

Publications and source records attributed to An-min Jin.

7 recordsLinked to original sources

PubMed2006

[Acidic fibroblast growth factor for preventing motor endplate degeneration and muscular atrophy after motor nerve injury: a morphological and electrophysiological study].

OBJECTIVE: To explore measures to prevent motor endplate degeneration and muscular atrophy after motor nerve injury. METHODS: Thirty Sprague-Dawley rats were randomized into 3 equal groups. In two of the groups, the right common peroneal nerves of the rats were transected and immediately sutured with implantation of collagen gel carrier of acidic fibroblast growth factor (aFGF) or the empty carrier into the denervated tibialis anterior muscles. In the control group, the transected nerves were sutured without implantation. Six weeks after the operation, morphological and electrophysiological examinations were performed. RESULTS: In the control rats and those with empty collagen gel carrier implantation, obvious motor endplate degeneration and muscular atrophy occurred, which were not obvious in rats receiving aFGF carrier implantation. The decrement of repetitive nerve stimulation was significantly greater in the former two groups than in the latter. CONCLUSION: Implantation of collagen gel carrier of aFGF may prevent motor endplate degeneration and facilitate functional recovery of the neuromuscular junction after motor nerve injury.

Animals↗

PubMed2006

[Development of an anti-infection nano-hydroxypatite drug delivery microsphere and its drug-release in vitro].

OBJECTIVE: To develop an anti-infection nano-hydroxypatite (nano-HA) microsphere for local drug delivery for treating osteomyelitis. METHODS: The nano-HA was used as the core carrier to load gentamicin (GM) and coated with poly(-hydroxybutyrate-co- hydroxyvalerate)/polyethylene glycol (PHBV/PEG), which was degradable and biocompatible, to prepare nano-HA-PHBV/PEG-GM microsphere. The surface structure and in vitro drug-release of the microsphere were studied. RESULTS: The microsphere had good drug delivery capability. The samples weighing 90 mg each were soaked in PBS and gentamicin release within the first day was 165.2 microg/ml, which maintained a low release rate in the following days. After 28 days, gentamicin release declined to 8.5 microg/ml, which was higher than the minimal inhibitory concentration of gentamicin (2 microg/ml). CONCLUSION: The local drug delivery system has good drug-release performance in vitro and may possess potential value in clinical management of osteomyelitis.

Anti-Bacterial Agents↗

PubMed2006

[Finite element analysis of a new shape memory alloy cervical hook for atlantoaxial instability].

The mechanics of a new shape memory alloy cervical hook for atlantoaxial instability was analyzed with finite element method on the basis of a three-dimensional model reconstructed from the images of CT scanning of an adult cadaveric upper cervical at 1-mm interval. The stress and displacement of every nodule and element in the course of deformation of the internal fixation were tested, and the results showed that the cervical hook was strong enough against tensile stress, which concentrates in the middle of the device. The pull was 237.58 N at the loading point. With such mechanical performance, this cervical hook can be reliable for correction of atlantoaxial instability.

Adult↗

PubMed2003

Detection of gene expression pattern in the early stage after spinal cord injury by gene chip.

OBJECTIVE: To study the changes of the gene expression pattern of spinal cord tissues in the early stage after injury by DNA microarray (gene chip). METHODS: The contusion model of rat spinal cord was established according to Allen's falling strike method and the gene expression patterns of normal and injured spinal cord tissues were studied by gene chip. RESULTS: The expression of 45 genes was significantly changed in the early stage after spinal cord injury, in which 22 genes up-regulated and 23 genes down-regulated. CONCLUSIONS: The expression of some genes changes significantly in the early stage after spinal cord injury, which indicates the complexity of secondary spinal cord injury.

Animals↗

PubMed2003

Three-dimensional porous poly-DL-lactide/basic fibroblast growth factor composites for bone defect repair: an experimental study.

OBJECTIVE: To investigate the osteoinductive ability of the composites consisting of basic fibroblast growth factor (bFGF) and porous poly-DL-lactide (PDLLA) for the development of a new absorbable osteosynthesis material. METHODS: Highly porous foams of PDLLA with the pore size ranging from 150 to 300 microm were prepared by a solvent-casting, particulate-leaching technique with NaCl as the leachable component. Animal models of radial diaphyseal defects of 1.0 cm with complete removal of the periosteum were induced in 45 rabbits, which were randomly divided into 3 groups to receive the defect repair with PDLLA and PDLLA/bFGF respectively, leaving one group untreated to serve as the control group. The implant specimens were harvested at 2, 4, 8, and 12 weeks respectively after the surgery and X-ray, histological and scanning electron microscopic (SEM) examinations were performed to evaluate the effectiveness of defect repair. At 8 and 12 weeks after implantation, biomechanical test (for three-point bending strength) was employed to study the quality of bone formation. RESULTS: PDLLA/bFGF composite stimulated more bone formation and had higher bending strength than PDLLA (P<0.05), and the bone formation induced by both materials was significantly more than that observed in the control group in every postoperative stage (P<0.05). CONCLUSION: PDLLA possesses good biocompatibility and absorbability, and when prepared into a porous material, it exhibits good osteoconductibility. As a good bFGF carrier, the foam of PDLLA with three- dimensional structure shows good osteoinductive ability with regard to the rapidity, quantity and quality of the bone formation.

Animals↗

PubMed2003

[Role of antisense oligodeoxynucleotide of inducible nitric oxide synthase in the apoptosis and p-p38 MAPK signal transduction in rat neurons after spinal cord injury].

OBJECTIVE: To study the role of antisense oligodeoxynucleotides (ASODN) of inducible nitric oxide synthase (iNOS) on the apoptosis and p-p38 mitogen-activated protein kinase (p-p38 MAPK) signal transduction of the neurons after spinal cord injury (SCI). METHODS: Antisense and non-sense oligodeoxynucleotides of iNOS were designed and synthesized, and injected into the subarachnoid space 12 h before the compressive injury was given to the rat spinal cord. Reverse transcription-PCR and flow-cytometry were used to examine the iNOS mRNA expression and the apoptosis of the neurons within the injured spinal cord. The changes of p-p38 MAPK signal transduction pathway were detected by Western blotting. RESULTS: Obvious increase in iNOS expression and up-regulated p-p38 MAPK were detected after SCI, and neuronal apoptosis was observed in the injured spinal cord. ASODN-iNOS treatment resulted in decreased expression levels of iNOS mRNA and p-p38 MAPK, and the neuronal apoptosis was alleviated. CONCLUSION: ASODN-iNOS inhibits iNOS expression and neuronal apoptosis following SCI which may be related to the p-p38 MAPK signal transduction pathway.

Animals↗

PubMed2003

Effect of aminoguanidine on the recovery of rat hindlimb motor function after spinal cord injury.

OBJECTIVE: To study the effects of aminoguanidine (AG), the inhibitor of inducible nitric oxide synthase (NOS), on the recovery of rat hindlimb motor function after spinal cord injury and explore the possible mechanism. METHODS: Thirty rat models of spinal cord compression injury were established according to Nystrom's method. AG therapy was administered for 4 times at 1 h before and 8, 24, 36 h after the injury, and 24 h after the completion of the therapy, spectrophotography was performed to measure the content of NO and activity of NOS in the injured spinal cord, followed by flow cytometry for determining the apoptotic rate 48 h later. The evaluation of the hindlimb motor function recovery was conducted by electrophysiological method and by measuring the behavior scores. RESULTS: AG significantly decreased the NO content (from 2.2714+/-0.4239 micromol/g.pro to 0.8466+/-0.0477 micromol/g.pro, P <0.05) and NOS activity (from 0.3408+/-0.0228 U/mg pro to 0.2702+/-0.0148 U/mg pro, P <0.05) in the injured spinal cord. The apoptotic rats were also reduced (from 7.88% +/-0.79% to 3.10% +/-0.66%, P <0.05). Four weeks after the therapy, the behavior score of the rats improved from 7.1+/-4.5 to 17.3+/-4.7 (P <0.01), and the latency and amplitude of the motor evoked potentials improved from 0 ms to 8.89+/-0.91 ms and from 0 mv to 1.99+/-0.48 mv respectively, showing significant therapeutic effect of AG (P <0.05). CONCLUSION: AG can improve motor functions of injured spinal cord in rats, possibly resulting from decreased apoptotic cells of the neurons in the spinal cord in the early stages of the injury.

Animals↗