Objective To evaluate the surgical treatment and effectiveness of rheumatoid forefoot reconstruction with arthrodesis of the first metatarsophalangeal joint and arthroplasty of lesser metatarsal heads. Methods Between January 2007 and August 2009, 7 patients with rheumatoid forefoot were treated by reconstruction with arthrodesis of the first metatarsophalangeal joint and arthroplasty of lesser metatarsal heads. They were all females with an average age of 62 years (range, 56-71 years) and with an average disease duration of 16 years (range, 5-30 years). All patients manifested hallux valgus, hammer toe or mallet toe of 2-5 toes, 5 feet complicated by subluxation of the second metatarsophalangeal joint. The improved American Orthopaedic Foot amp; Ankle Society (AOFAS) score was 36.9 ± 6.4. The hallux valgus angle was (46 ± 5)°, and the intermetarsal angle was (12 ± 2)° by measuring the load bearing X-ray films preoperatively. Results All incisions healed by first intention after operation. The X-ray films showed bone fusion of the first metatarsophalangeal joint at 3-4 months after operation. Seven patients were followed up 2.9 years on average (range, 2-4 years), gait was improved and pain was rel ieved. The hallux valgus angle decreased to (17 ± 4)° and the intermetarsal angle was (11 ± 2)° at 3 months postoperatively, showing significant differences when compared with preoperative values (P lt; 0.05). The improved AOFAS score was 85.3 ± 5.1 at 2 years postoperatively, showing significant difference when compared with preoperative score (t=4.501, P=0.001). One patient had recurrent metatarsalgia at 4 years after operation. Conclusion Arthrodesis of the first metatarsophalangeal joint and arthroplasty of lesser metatarsal heads for rheumatoid forefoot reconstruction can correct hallux valgus, remodel the bearing surface of the forefoot, and rel ieve pain, so it can be considered as a procedure that provides improvement in the cl inical outcome.
Objective To observe the efficiency and biological characteristics in regenerating in vitro tissue-engineered cartilage from epiphyseal chondrocyte-scaffold complex. MethodsThe first passage epiphyseal chondrocytes were collected and mixed with the biological gel-matrix, the chondrocyte-gel fluid wasdropped into the scaffold to form a complex. The complexes were in vitro cultivated. The changes of complexes in morphology and synthesis of collagens type ⅡandtypeⅠ and aggrecan were observed under the gross and the inverted and light microscopes. The sulfate GAG content in complexes was measured by the the modified dimethylmethylene blue method. Results During cultivation, thecomplexes could keep its original shape with the stable homogeneous three-dimensional distribution of chondrocytes，gradually became milk white and translucence with their rigidity increasing. In the 1st week, the chondrocytic lacunae formed in the complexes. After 2 weeks, the complex was gradually reorganized into the mature engineered cartilage with rich collagen typeⅡand aggrecan and typical cartilage histological structure, but with negative immunological staining of collagen typeⅠ. In the 4th week, the engineered cartilage resembled the nature epiphyseal plate in the characteristic of histological structure, and had over 34% of the sulfate GAG content of the natural epiphyseal plate. Conclusion Theepiphyseal chondrocyte-scaffold complex can be reorganized into typical cartilage with the epiphyseallike histological structure, and be fit for repairing the epiphyseal defect. The tissue engineered cartilage cultivated for 1-2 weeks may be a good choice for repairing epiphyseal defect.
OBJECTIVE: To observe the effect of engineered epiphyseal cartilage regenerated in vitro with 3-D scaffold by chondrocytes from epiphyseal plate in repairing the tibial epiphyseal defect, and to explore the methods to promote the confluence between engineered cartilage and epiphyseal plate. METHODS: Chondrocytes were isolated enzymatically from the epiphyseal plates of immature rabbits, and then planted into the tissue culture flasks and cultivated. The first passage chondrocytes were collected and mixed fully with the self-made liquid biological gel at approximately 2.5 x 10(7) cells/ml to form cell-gel fluid. The cell-gel fluid was dropped into the porous calcium polyphosphate fiber/poly-L-lactic acid(CPPf/PLLA)scaffold, and a cell-gel-scaffold complex formed after being solidified. The defect models of 40% upper tibial epiphyseal plate were made in 72 immature rabbits; they were divided into 4 groups: group A(the cell-gel-scaffold complex was transplanted into the defect and the gap filled with chondrocyte-gel fluid), group B (with noncell CPPf/PLLA scaffold), group C(with fat) and group D(with nothing). The changes of roentgenograph, gross and histology were investigated after 2, 4, 6, 8, 12 and 16 weeks of operation. RESULTS: In group A, the typical histological structure of epiphyseal plate derived from the engineered cartilage with a fine integration between host and donor tissues after 2 weeks. The repaired epiphyseal plate had normal histological structure without deformation of tibia after 4 weeks. The early histological change of epiphyseal closure appeared in the repaired area with varus and shortening deformation of the tibia after 8 weeks. The epiphyseal plate was closed in the repaired area with more evident deformation of tibia; the growth function of repaired epiphyseal plate was 43.6% of the normal one. In groups B, C and D, deformation of tibia occurred after 2 weeks; the defect area of epiphyseal plate was completely closed after 4 weeks. The deformation was very severe without growth of the injured epiphyseal plate after 16 weeks, and no significant difference was observed between the three groups. CONCLUSION: Engineered epiphyseal cartilage can repair the epiphyseal defect in the histological structure with partial recovery of the epiphyseal growth capability. Injecting the suspension of fluid chondrocyte-gel into the defects induces a fine integration of host and donor tissues.
OBJECTIVE: To comprehend the progress of tissue engineering research and speculate its developmental trends. METHODS: MEDLINE search was conducted to retrieve the papers published between 1987 to 1999 under the main headings of tissue engineering. Years, nationalities, languages, journals, authors and heading frequencies of 314 papers were analyzed by bibliometrics. RESULTS: Since 1990, the number of tissue engineering research literatures had doubled, and papers between 1998 and 1999 made up 57.96% of the total papers. All papers came from 15 nations, in 6 languages and 140 journals; 64.97% came from United States and 25.79% from England, Netherlands and Germany; 93.95% was in English; 42.04% was published on 15 journals. Vacanti JP and 19 other authors presented 5 to 24 papers. Heading frequencies were cytology 22.89%, transplantation 13.30%, scaffolds and extracellular matrixes 11.72%, implanting 10.60%, polymers 8.91%, potential applications 8.91%, artificial substitutes 6.88%, tissue culture 6.70% and biogenetics 4.96%. CONCLUSION: Tissue engineering literatures mainly come from United States, England, Netherlands and Germany. English is the major language. J Biomed Mater Res and 14 other journals are important journals about tissue engineering research. Vacanti JP and 19 other authors are prolific authors. Cytology, transplantation, scaffolds and extracellular matrixes and implanting are hot topics and key points on tissue engineering research.
To explore the shape and structure of calcified cartilage zone and its interface between the non-calcified articular cartilage and subchondral bone plate. Methods The normal human condyles of femur (n=20) were obtained from the tissue bank donated by the residents, 10 males and 10 females, aged 17-45 years. The longitudinal and transverse paraffin sections were prepared by the routine method. The shape and structure of calcified cartilage zone were observed with theSafranin O/fast green and von kossa stain method. The interface conjunction among zones of cartilage was researched by SEM and the 3D structural model was establ ished by serial sections and model ing technique. Results Articular bone-cartilage safranin O/fast green staining showed that cartilage was stained red and subchondral bone was stained blue. The calcified cartilage zone was located between the tidemark and cement l ine. Von kossa staining showed that calcified cartilage zone was stained black and sharpness of structure border. Upper interface gomphosised tightly with the non-calcified cartilage by the wave shaped tidemark and lower interface anchored tightly with the subchondral bone by the uneven comb shaped cement l ine. The noncalcified cartilage zone was interlocked tightly in the manner of “ravine-engomphosis” by the calcified cartilage zone as observed under SEM, and the subchondral bone was anchored tightly in the manner of “comb-anchor” by the in the calcified cartilage zone 3D reconstruction model. Conclusion The calcified cartilage zone is an important structure in the articular cartilage. The articular cartilage is fixed firmly into subchondral bone plate by the distinctive conjunct interfaces of calcified cartilage zone.
ObjectiveTo investigate the effects of specific farnesiod X receptor(FXR) agonist on growth of colon cancer cells in vitro. MethodsThe effects of specific FXR agonist(GW4064) on the growth of HCT116 cells of colon cancer were studied in vitro by using MTT and flow cytometry. The mRNA expressions of FXR and vascular endothelial grouth factor(VEGF), were determined by using RT-PCR. ResultsThe FXR specific agonist GW4064 could increase the FXR mRNA expression of HCT-116 cells of colon cancer, downregulation of VEGF mRNA expression, and had obvious inhibitory effect on growth of HCT-116 cells, and promoted the apoptosis of HCT116 cells in a dose and time dependence. ConclusionsGW4064 can significantly inhibit colon cancer cells in vitro. FXR may be a potential treatment arget of colon cancer.
To evaluate the implantation effect of artificial vascular grafts with recombinant fibrinolytic enzyme factor II (rF II)-immobil ized lumina in animal test. Methods Four mm internal diameter (ID) polyurethane (PU) artificial vascular grafts were prepared by di pping and leaching method. The micro-pore size and morphology of the graft walls were observed by SEM. The graft lumina were immobil ized with rF II. Twenty hybrid male dogs [weighing (20 ± 1) kg] were used for animal model of carotid artery defect and were randomly divided into 3 groups: rF II -immobil ized PU group, no rF II -immobil ized PU group and expanded polytetrafluoroethylene (ePTFE) group. The vascular grafts were implanted for repairing injured segments of carotid artery in dogs. The general health state of animals was recorded. At 30 days and 60 days,the patency rate of every group was calculated. At 60 days IDs were measured, cell prol iferation in neointima was inspected by l ight microscope, morphology on neointima was observed by SEM. Results The ID of the PU vascular grafts was (3.74 ± 0.06) mm, wall thickness was 0.4-0.6 mm, the wall density was 0.25 g/cm3, the porosity was 79.8%, racical compl iance was 8.57%/100 mmHg. In the wall, micropores were well distributed and opened-pores structure was observed. Pore size was (140 ± 41) μm in the outside layer, pore size was (100 ± 3) μm in the inside layer, thickness ratio of outside / inside layers was 2 ∶ 1, the pore size was (40 ± 16) μm on the lumina surface. After operation the wounds on neck healed, all the animals survived and had no compl ication. At 30 days and 60 days after implantation, the patency rate for rF II -immobil ized PU group were 100% and 66.7%, for no rF II -immobil ized PU group were 66.7% and 33.3%, and for ePTFE group were 67.7% and 0 respectively, but at 60 days there were thrombosis at anastamotic sites of some grafts occluded. Before operation the IDs for rF II-immobil ized PU group, no rF II -immobil ized PU group and ePTFE group were (3.74 ± 0.06), (3.74 ± 0.06) and (4.00 ± 0.03) mm, at 60 days after operation the IDs were (4.51 ± 0.05), (4.31 ± 0.24) and (4.43 ± 0.12) mm respectively, showing no statistically significant differences between 3 groups (P gt; 0.05). Histological inspection indicated that at 15 days a layer of plasma protein deposited on the lumina, at 30 days some cells adhered to the lumina, at 60 days neointima could be observed on the lumina. Thickness of the neointima became larger with implantation time. At 60 days neointima thickness at proximal end, middle site and distal end ofgraft were (560 ± 22), (78 ± 5) and (323 ± 31) μm respectively for rF II -immobil ized PU group. The results of SEM showed that neointima surface consisted of flat and long cells which long axes ranged with blood flow direction and was similar to lumina morphology of carotid artery of dog. Conclusion Immobil ization of rF II to lumina of grafts could enhance fibrinolytic activity and inhibited formation of thrombo-embol ia which led to an increase in patency rate after implantation.