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Biomedical subjects

Guo-xian Pei

Publications and source records attributed to Guo-xian Pei.

At least 19 recordsLinked to original sources
PubMed2007

Distribution and property of nerve fibers in human long bone tissue.

OBJECTIVE: To observe the distribution of the nerve fibers in the bone tissue and the entry points of these fibers into the bone. METHODS: The adult tibia was used for the ground sections which were afterwards made into the slice sections by decalcification in ethylenediamine tetraacetic acid (EDTA). The ground sections were stained in silver and the slice sections were stained in silver and haematoxylin and eosin (HE) respectively. Then, the samples of the transmission electron microscope and the atomic force microscope were made and observed. RESULTS: In the human long bone tissue, many nerve fibers were distributed in the membrane, cortical bone, cancellous bone and marrow. The nerve fibers entered the bone from the nutrient foramen, and passed through the nutrient canal, Haversian's canal and Volkmann's canal, and finally into the bone marrow. In the nutrient canal, the nerve fibers, mainly the medullary nerve fibers, followed the blood vessel into the bone. In the cortical bone, the nerve fibers also followed the blood vessels and were mainly distributed along Haversian's canal and Volkmann's canal. In the bone trabecular and bone marrow, there were many nerve fiber endings arranged around the blood vessels, mainly around the tunica media of medium-size arteries in the marrow and around capillary blood vessels, and a few scattered in the bone marrow. There were sporadic nerve endings in epiphyseal plate and no nerve fibers permeated epiphysis to diaphysis. No distribution of nerve fibers could be found in cartilaginous part. CONCLUSIONS: There are many nerve fibers in bone and the nerve passageway is nutrient foramen, Volkman's canal, Haversian's canal and bone marrow.

Adult↗
PubMed2006

[Long-term observation of large weight-bearing bone defect in goats repaired with tissue engineering technique].

OBJECTIVE: To observe the long-term effect of tissue engineering-based repair of large weight-bearing bone defect in goats, and the final outcome of the scaffold material coral hydroxyapatite (CHAP) in vivo. METHODS: Fifteen Chinese goats were subjected to operations to induce a 2-cm left tibial diaphyseal defect, which was filled subsequently with CHAP and bone marrow stromal stem cells (BMSCs). The repaired defects were evaluated by ECT, X-ray and histology in the early stage and at 6, 12, 18, and 24 months postoperatively. RESULTS: ECT showed good bone regeneration and revascularization within 2 months postoperatively. X-ray and histology displayed eccentric and gradual bone regeneration in the early stage, and the tissue-engineered bone graft was firmly healed with the goat tibia. X-ray and histological examination at 6, 12, 18, 24 months postoperatively revealed moulding of the new bones and medullary cavity recanalization, and the structure of CHAP disappeared and gradually integrated into the new bones. CONCLUSION: Tissue-engineered bone is capable of total repair of large bone defect in goats by forming normal functional new bones. CHAP can be eventually degraded completely and become the component of the newly generated bones.

Animals↗
PubMed2006

[Perfusion-weighted magnetic resonance imaging for monitoring vascularization in tissue-engineered bone in rhesuses].

OBJECTIVE: To assess the value of perfusion-weighted magnetic resonance (MR) imaging (PWMRI) in monitoring vascularization in tissue-engineered bone graft. METHODS: Tibial diaphyseal defect of 20 mm was induced in 25 lower limbs of 13 rhesuses and fixed with an AO reconstruction plate with 7 holes. The monkeys were randomized into 5 groups according to the materials used for defect filling: group A, with beta-tricalcium phosphate (beta-TCP), bone marrow stromal cells (BMSCs) and blood vessel bundles; group B, with beta-TCP and blood vessel bundles; group C, with beta-TCP and BMSCs; group D, with beta-TCP, and group E without filling. PWMRI, X-ray, and radionuclide imaging were carried out at weeks 4, 8, 12 postoperatively. The maximum slope rates of the single intensity-time curve (SS(max)) and the baseline values (SI(baseline)) on the same time points were calculated. Transmittances on the X-ray films and isotope counts in the region of interest (ROI) were assessed and calculated. RESULTS: Compared with other groups, group A showed the highest SS(max) at weeks 4, 8, and 12 postoperatively, and its SS(max) at week 8 was significantly higher than that at week 4 (P=0.003). The SS(max) was positively related to isotope counts in ROI at week 8 after operation (r(s)=0.899, P=0.038), and inversely related to transmittance on X-ray films at week 12 (r(s)=-0.892, P=0.042). CONCLUSION: The SS(max) of the single intensity-time curve can accurately reflect the vascularization of the tissue-engineered bone graft, and PWMRI allows sensitive, quantitative, noninvasive and radiation-free vascularization monitoring.

Animals↗
PubMed2005

[In vitro biocompatibility of novel absorbable hydroxyapatite and AO artificial bone beta-tricalcium phosphate with rhesus bone marrow stromal cells].

OBJECTIVE: To study the in vitro biocompatibility of novel hydroxyapatite (HA) and AO artificial bone beta-tricalcium phosphate (beta-TCP) with rhesus bone marrow stromal cells (rBMSCs) . METHODS: The third passage of rBMSCs were cultured with HA and beta-TCP respectively, with the cells cultured without the materials as the control. The morphology and proliferation of cells were observed by inverted phase-contrast microscope and scanning electron microscope (SEM). MTT assay was used to semiquantitatively evaluate the cell proliferation. RESULTS: The rBMSC cocultured with HA exhibited good growth as observed under inverted phase-contrast microscope, without significant difference from the cells in the control group. Some small particles were seen pealing off from beta-TCP, and some of the cells died. Under SEM, rBMSCs showed good adhesion to HA with obvious proliferation, but the ratio of adhesive cells was not as high as that in beta-TCP group. MTT assay showed no significant difference in the cell number between HA and the control groups, but the cell number in beta-TCP group was notably less than that of control group. CONCLUSION: Novel HA has good biocompatibility with rBMSCs for bone tissue engineering, and AO artificial bone still needs improvement to serve as scaffold material for BMSCs.

Absorbable Implants↗
PubMed2005

[Bone defect repair with a new tissue-engineered bone carrying bone morphogenetic protein in rabbits].

OBJECTIVE: To construct a new tissue-engineered bone with poly (D, L-lactide-co-glycolide) (PLGA), bone morphogenetic protein (BMP) and bone marrow-derived stem cells (BMSCs) and observe its effect in repairing segmental bone defects. METHODS: A 15-mm bone defect in the right radius was induced in New Zealand white rabbits, and the models were randomized into three groups to receive implantation of the tissue-engineered bone grafts constructed with PLGA carrying 5 mg BMP and about 1 x 10(6) BMSCs (experimental group), grafts of PLGA with about 1 x 10(6) BMSCs (control group), or grafts of exclusive PLGA (blank control group), respectively. The osteogenesis in the bone defect after the implantation on was evaluated X-ray films, and the histological changes of the tissues sampled from the bone defect 4, 8, and 12 weeks after operation were observed and new bone formation was measured by image analysis. RESULTS: The bone defect was completely repaired in the experimental group 12 weeks after the implantation, showing the best results among the 3 groups. The bone defects in the blank control group was filled with only fibrous and connective tissues at 12 weeks. CONCLUSION: This tissue-engineered bone constructed with PLGA, BMP and BMSCs possesses good ability in repairing segmental bone defect.

Animals↗
PubMed2004

Monitoring of T lymphocyte subset during ATG induction therapy in hand allograft with report of 3 cases.

OBJECTIVE: To investigate the significance of T lymphocyte subset determination during antithymocyte globulin (ATG) induction therapy in reducing the total drug dose, incidence of complications and cost of treatment in hand allograft. METHODS: The changes in peripheral blood T lymphocyte subsets (CD3+, CD4+, CD8+, and CD28) were determined by flow cytometry in 3 cases of hand allograft who received ATG treatment. RESULTS: Flow cytometry showed that the percentages of CD3+, CD4+, and CD8+ T lymphocytes, along with the ratio of CD4/CD8, decreased significantly during ATG induction therapy, and the results were consistent in the 3 cases. Long-term continuous changes of peripheral blood lymphocytes were observed after antithymocyte globulin induction therapy. CONCLUSION: The understanding of the immunological state of the patient with hand allograft after ATG induction therapy by monitoring T lymphocyte subsets may allow adjustment of the total dose of the drugs administered and help prevent the occurrence of complications.

Adult↗
PubMed2004

[Hemostatic aerosol for emergent management of artery rupture].

OBJECTIVE: To investigate the effect of the hemostatic aerosol (HA) for emergent management of artery rupture in pigs. METHODS: Thirty pigs were used to establish animal models of complete femoral artery rupture by cutting off the arteries. The pigs were divided equally into 3 groups according to the hemostatic measures taken before the application of HA, namely HA spray alone, temporary hemostasis by compressing the wound with fingers, or tourniquet in another group, before HA sprays. In the late groups the finger compression or tournigut was removed 10 min after HA spray. The main indexes including average arterial blood pressure (AABP), times of spray, hemostatic time, time for membrane formation and the thickness of the HA membrane shaped while spraying, and the success rates of each method, were assessed 12 h postoperatively. RESULTS: The rate of successful hemostasis achieved by tourniquet and HA spray was 90%, 30% by finger compression and HA spray, and only 10% by direct HA spray. CONCLUSIONS: For complete artery rupture, application of tourniquet for temporary hemostasis 10 min before HA spay can be the best choice for emergent management of artery rupture.

Aerosols↗
PubMed2004

[Fingertip replantation after amputation: report of 32 fingers].

OBJECTIVE: To describe the surgical techniques and our experiences in fingertip replantation after amputation. METHODS: On the basis of examination of the anatomic features and the degree of fingertip vascular injury, 32 amputated fingertips in 26 cases were replanted, and flexible revascularization procedures of both artery and vein anastomoses, artery-only anastomosis, arterialized vein and arteriovenous anastomosis were adopted. All the replanted fingertips were trained with comprehensive rehabilitation program. RESULTS: Twenty-nine replanted fingertips survived but 3 failed, and the overall survival rate was 90.06%. During the follow-up lasting from 4 months to 5 years, the 29 replanted fingertips survived with excellent blood supply, good sensory functions, satisfactory shape and functions according to the criteria by Society of Hand Surgery of Chinese Medical Association. CONCLUSIONS: Fingertip replantation after amputation can achieve not only high survival rate but also satisfactory appearance and functions as long as appropriate operative procedures are adopted with comprehensive rehabilitation therapy.

Adolescent↗
PubMed2004

[Retrograde intramedullary locked nail and bolt for comminuted fracture in the femur condyles].

OBJECTIVE: To evaluate the therapeutic effects of locked supracondylar intramedullary nail and bolt for treating comminuted fracture in the distal end of the femur. METHODS: Forty-two patients (including 31 male and 11 female patients) with supracondylar and intercondylar fractures, classified into type C1 in 20 cases and type C2 in 22 cases according to AO classification, were treated with retrograde intramedullary nail and bolt. RESULTS: The follow-up period ranged from 3 to 18 months and the average time of bone healing was 4.6 months. Assessed by functional scoring, the results were excellent in 31 patients, good in 10, and acceptable in 1, with the rate of excellent result as high as 97.6%. CONCLUSIONS: Retrograde intramedullary nail and bolt can be ideal for treating supracondylar and intercondylar fractures. The bolt can effectively control the dissociation of the intercondylar fractures and good functional recovery of the knee joint can be achieved through early functional training.

Adult↗
PubMed2004

[Fabrication of laryngeal cartilage by means of tissue engineering technique].

OBJECTIVE: To explore the method of fabricating tissue engineered laryngeal cartilage. METHODS: The rib and articular cartilage of infant New Zealand white rabbits were harvested in sterile condition. The chondrocytes were separated by collagenase digestion and cultured in vitro for 3 passage. Serial steps of solution casting, extrusion molding and particulate leaching were used to make larynx-shaped biomaterial models with poly(3-hydroxybutyrate-co-3-hydroxyhexanoate, PHBHH). The chondrocytes were seeded onto PHBHH scaffolds to form cell-PHBHH composites, which were subsequently in vitro for one week. After that, the measure of filling inner space of cell-PHBHH composites together with wrapping total composites using either greater omentum (n = 9) or fascia flap and muscle (also n = 9) in experimental groups was taken to implant the larynx-shaped biomaterial models seeded with chondrocytes into the belly and the back of adult New Zealand white rabbits. Control groups (every group n = 3) were the same measure as experimental groups but without chondrocyte on PHBHH scaffolds. Finally, morphological observation, HE staining & special staining and immunohistochemical test were conducted to assess cartilage regeneration and its shape at different period following implantation. RESULTS: The rate of viable cell in the final cell suspension was (93 +/- 2)% after well-controlled prolongation of digestion trypsin. Similar to that by traditional procedures (94 +/- 2)% (P > 0.05). The larynx-shaped PHBHH models with edges and corners of laryngeal cartilage made by us appeared to be hollow half-trumpet shape and its porosity was more than 90%. It showed that chondrocytes equally attached to the surface of porous PHBHH and filled within porousness with scanning electron microscopic examination. Tissue engineered larynx-shaped specimens could alternatively be harvested with the above mentioned two different implantation measures. The specimens presented to be similar to that before implantation in gross shape. It was demonstrated to be cartilaginous tissue through histological and immunohistochemical examination. Furthermore, There was nearly no difference between two kinds of tissue engineered laryngeal cartilage with two measures of implantation in morphology and histology. CONCLUSIONS: The regeneration of tissue engineered cartilage in vivo is not influenced by the chondrocytes harvested by improvement of well-controlled prolonged digestion with trypsin during in vitro cell culture. It seems that PHBHH may be used as scaffold in cartilage tissue engineering and wrapping together with filling method with either greater omentum or fascia flap and muscle is appropriate for fabricating tissue engineered laryngeal cartilage.

Animals↗
PubMed2004

[Study of osteoblasts transfected with gfp in vitro and traced in vivo].

OBJECTIVE: To observe the osteoblasts transfected with green fluorescent protein (GFP)by adenovirus vector expressed in vitro and traced it in vivo in order to research the feasibility of GFP as a tracer of seeding cells for tissue engineering. METHODS: CFP were transfected into the osteoblasts which derived from adult human bone marrow stromal cell (hBMSc) by adenovirus vector after being packed in 293A cells. The nontransfected hBMSc was used as the control group. The osteoblasts in each group were observed under an inverted phase contrast microscope and fluorescence microscope. The expressive efficiency of GFP was examined by flow cytometry,and alkaline phosphatase (ALP) activities and osteocalcin (OCN) synthesis. After eight days of the transfection,the osteoblasts were implanted into the muscle of nude mouse thigh while the non-transfected osteoblasts were also implanted as a control. Four and eight weeks after the operation, the nude rats were killed and the continuous tissue sections were examined using fluorescence microscopy after adjacent sections were performed by immunohistochemistry or routine HE staining. RESULTS: The green fluorescence was shown the transfected osteoblasts which derived from bone marrow. The rate of positive expression was over 75%. After eight days of the transfection, the marker proteins of the surface of the osteoblasts showed extremely efficient expression of CD29 and CD44, but the CD34 expressed negative. Either ALP or OCN of the osteoblasts was no significant difference between the two groups (P > 0.05) four and eight days after the transfection. The GFP were obviously expressed in nude mouse both at four and eight weeks, meanwhile it did not harm on the morphology and function of the transfected osteoblasts whose immunohistochemistry examination showed positive reaction. CONCLUSIONS: GFP could be transfected osteoblasts effectively in vitro and traced in vivo in nude mouse. It may be an optimal tracer for living cells on tissue engineering research.

Adult↗
PubMed2003

[The regulatory effect of human bone morphogenetic protein 7 gene transfer on the proliferation and differentiation of rabbit bone marrow mesenchymal stem cells].

OBJECTIVE: To detect the proliferation and differentiation of rabbit bone marrow mesenchymal stem cells (BMSc) transferred by retroviral vector carrying human bone morphogenetic protein 7 (hBMP-7) gene. METHODS: hBMP-7-expressing replication-deficient retroviral vector(PT-PLNCX2-hBMP7) was reconstructed using clone technique and recombinant DNA technique. BMSc were infected with the virus granules. The protein of BMP-7 gene in transferred cells were determined by immunohistochemistry. The proliferativity of the transferred cell were assayed by methabenzthiazuron (MTT) method and flow cytometer. Alkaline phosphatase (ALP) were also detected using enzyme kinetics. RESULTS: Cells transferred by PT-PLNCX2-hBMP7 expressed abundant hBMP7 protein in the cytoplasm. Positive findings were not found in those cells that were not transferred. After infected with virus there were not significant difference of cell proliferation and cell cycle between the cells transferred by hBMP-7 or not (P > 0.05). ALP activity in transferred cells were increased significantly (P < 0.01). CONCLUSIONS: hBMP-7 can be transferred and stably expressed in the cultured rabbit bone marrow stem cells. Proliferation and cell cycle of the transferred cell were not affected. hBMP7 gene transfer can be used to induce differentiation of BMSc into osteoblast-like cells.

Alkaline Phosphatase↗
PubMed2003

[The method of accelerating osteanagenesis and revascularization of tissue engineered bone in big animal in vivo].

OBJECTIVE: To study whether tissue engineered bone can repair the large segment bone defect of large animal or not. To observe what character the fascia flap played during the osteanagenesis and revascularization process of tissue engineered bone. METHODS: 9 Chinese goats were made 2 cm left tibia diaphyseal defect. The repairing effect of the defects was evaluated by ECT, X-ray and histology. 27 goats were divided into three groups: group of CHAP, the defect was filled with coral hydroxyapatite (CHAP); group of tissue engineered bone, the defect was filled with CHAP + bone marrow stroma cells (BMSc); group of fascia flap, the defect was filled with CHAP + BMSc + fascia flap. After finished culturing and inducing the BMSc, CHAP of group of tissue engineered bone and of fascia flap was combined with it. Making fascia flap, different materials as described above were then implanted separately into the defects. Radionuclide bone imaging was used to monitor the revascularization of the implants at 2, 4, 8 weeks after operation. X-ray examination, optical density index of X-ray film, V-G staining of tissue slice of the implants were used at 4, 8, 12 weeks after operation, and the biomechanical character of the specimens were tested at 12 weeks post operation. RESULTS: In the first study, the defect showed no bone regeneration phenomenon. 2 cm tibia defect was an ideal animal model. In the second study, group of CHAP manifested a little trace of bone regeneration, as to group of tissue engineered bone, the defect was almost repaired totally. In group of fascia flap, with the assistance of fascia flap which gave more chance to making implants to get more nutrient, the repair was quite complete. CONCLUSIONS: The model of 2 cm caprine tibia diaphyseal defect cannot be repaired by goat itself and can satisfy the tissue engineering's demands. Tissue engineered bone had good ability to repair large segment tibia defect of goat. Fascia flap can accelerate the revascularization process of tissue engineered bone. And by this way, it augment the ability of tissue engineered bone to repair the large bone defect of goat.

Animals↗
PubMed2003

[Surgical repair of major vascular injuries in the extremities complicated by other injuries: retrospective analysis of 67 cases].

OBJECTIVE: To retrospectively analyze the surgical repair of injured major vessels in the extremities complicated by multiple other injuries. METHODS: According to different time lengths of sustaining ischemia, sites of the major vascular injuries and conditions of other injuries, 91 operations for end-to-end anastomosis, vessel grafting and repair, ligation and shunting respectively were performed on the 67 patients. RESULTS: Except for 2 fatal cases (one due to preoperative brain hernia and hemorrhagic shock, the other to thyroid crisis during operation), all other cases survived the operations. Vascular crisis occurred in 3 cases (2 arterial spasm and 1 venous crisis) 6, 7 and 12 h respectively after the operations, which were relieved by appropriate treatments and surgical explorations. One patient developed pneumonia and acute renal failure with polyuria at postoperative days 7 and 4 respectively, but full recovery was achieved. CONCLUSIONS: For patients with major vascular injuries in the extremity complicated by multiple other injuries, timely revascularization of the extremities should be performed during or immediately after emergency operations of the vital organs. Particular attention should be given to the diagnosis and repair of closed major vascular injuries in such patients, who need to be monitored for blood coagulation during operation and should receive due post-operative anti-coagulation treatment.

Adolescent↗
PubMed2003

A preliminary pathological study on human allotransplantation.

OBJECTIVE: To observe the survival of hand allograft under the state of immunosuppression and the pathological changes of rejection in the recovery process. METHODS: The biopsies of the skin, nerve, muscle, tendon and bone tissue of hand allografts during different stages from 1 day to 7 months after operation were observed using routine histological technique. RESULTS: No significant changes due to rejection in skin, nerve, muscle and bone tissue were observed. But different degrees of weak rejective changes were found on the wall of blood vessels; in the muscle and nerve the reactions were markedly stronger than those found in skin tissues. CONCLUSIONS: The rejection in deep tissues should be monitored in controlling the rejection of hand allograft.

Adult↗
PubMed2003

[Effect of bone morphogenetic protein microspheres on biological behavior of rabbit bone marrow stem cells].

OBJECTIVE: To evaluate the effect of bone morphogenetic protein (BMP) on the biological behavior of bone marrow stem cells (BMSCs) of rabbits. METHODS: BMP was either enwrapped or not in the microspheres made of chitosan and sodium alginate, and the biocompatibilities of the composites were examined by means of cell culture. The BMSCs were cultured with the two kinds of microspheres respectively, and the cell extension rate, proliferation, alkaline phosphatase activity and Coomassie blue staining of the cells were assayed. RESULTS: Inhibition of BMSC proliferation did not occur in response to in vitro culture with the microspheres, but alkaline phosphatase activity and D(lambda) values of Coomassie blue staining increased significantly in the cells cultured with BMP microspheres. CONCLUSION: BMP can increase the osteogenic capacity of BMSCs in vitro with the microspheres made of chitosan and sodium alginate as the carrier.

Animals↗
PubMed2003

[Finger reconstruction with extended free second toe flap transfer].

OBJECTIVE: To investigate an ideal method for finger reconstruction with extended the second toe flap transfer. METHODS: The second toe free flap was created, combined with an pedicled skin flap from the fibular side of the great toe inlaid in the ventral side of the second toe, a double-wing flap and the distal part of the metatarsal bone. The composite free flap was transferred by vascular anastomosis for finger reconstruction. RESULTS: The reconstructed finger exhibited nice looking and better function. The procedure had little influence to the appearance and function of the donor foot. CONCLUSION: This method is effective in ameliorating the appearance and function of the reconstructed finger with the second toe transfer.

Adult↗