砄bjective:To fabricate bone tissue that has similar structural and mechanical characters with normal bone.Methods: Titanium meshes were molded into the shape of column in the length of 12 mm and in the diameter of 8 mm. The column was filled with natural coral granduls.4?10 7 marrow derived osteoblasts in 200 ?l cell culture medium were seeded into each of five scaffolds and incubated in vitro for 2 d to ensure that cells adhere well on the scaffolds. Then the scaffolds were implanted subcutaneously into the back of nude mice. Two months after implantation, the animals were sacrificed and the implanted materials were investigated by gross specimen inspection, X ray examination and histological observation. Results:2 months after in vivo incubation, the newly formed tissue was red and had the gross appearance of bone, and kept the original shape of column. Titanium mesh situated in the surface area. X ray examination showed that large amount of new bone formed in the scaffolds, there was no space between new bone and titanium mesh. Most of coral granduls had been absorbed. Histological observation demonstrated that in the surface area, new bone integrated well with titanium mesh and was enforced by titanium mesh(like cortical bone), and in the middle area large amount of lamellar bone formed.Conclusion: Newly formed bone in this experiment has similar structural with normal cortical bone.

Objective The purpose of this study was to investigate the effect of blood supply decrease on glycosaminoglycans(GAG)of the cartilage in the temporomandibular joint(TMJ) . Method Four rabbits were used as controls, and 16 rabbits were injected 5% sodirm morrhumate through carotid artery unilaterlally. All specimens were examimined histochemically. Result A reduction in alcian(AB) blue staining was observed after operation, a gradual increase in AB staining with blood supply restoration of TMJ tissue was observed. Conclusion The result suggests that the decrease in blood supply of the temporomnandibular jorint leads to the loss of GAG in the condylar cartilage, which may play an important role in pathogenesis of osteoarthrosis.

Objective: To prepare tissue engeneered bone in the shape of human TMJ condyle. Methods: Rabbit marrow stem cells (MSCs) were in vitro cultured and induced by rhBMP2.107 Cells were seeded into each piece of natural porous coral (NC) in the shape and in the size of 4 -year-old-child mandibular condyle. After two days in vitro incubation, six cell-coral complexes were implanted subcautanrously into the back of nude mice. Two months after operation, bone formation was observed by gross inspection,X-ray examination,scanning electronic microscope observation and histological observation. Results: New bone grafts in the shape of human mandibular condyle were successfully restored two months after implantation in all the samples. X-ray examination showed large amount of X-ray blocking shadow. NC was partially absorbed. New bone formation could be observed by electronic microscope observation and hostological observation on the surface and in the pores of NC. Conclusion: It is an effective method to fabricate bone graft in specific shape by seeding osteogenesis cells into natural coral in the wanted shape.

Objective: To prepare tissue engieered bone graft loading titanium dental implant. Methods: Titanium dental implant (3 mm in diameter) was inserted into porous natural coral column((5 mm in diameter). Bone marrow derived osteoblasts were cultured and expanded in vitro. Cells were induced by recombinant human bone morphogenetic protein-2 for three days and then harvested and seeded into porous coral and onto dental implant at the density of 2 ?108/ml. Four cell-coral-implant complexs were incubated in vitro for 2 days and then implanted subcutaniously into nude mice. New bone formationre and new bone integration with dental implant were evaluated by gross inspection, X-ray examination and hitologic observation 1 and 2 months after implantation. Results: By gross observation, specimen of 1 month was red and white. X-ray examination showed that there was little radiodense shadow around the dental implant. Specimen of 2 months was red and had the gross appearance of bone. Dental implant could be observed situating in the newly formed bone graft. X-ray examination showed that coral scaffold was absorbed completely. Large amount of X -ray blocking shadow could be observed around the dental implant. Histologic examination showed that bone-like tissue formed in the pores and on the surface of natural coral and in some area new bone could be observed integrating with implant in 1 month specimen. In 2 months specimen, large amount of new bone formed around the implant and integrated well with the implant. Conclusions: Tissue engineered bone graft may integrate well with titatium dental implant.

OBJECTIVESeed cell study is an essential area in the research of tissue engineering. To evaluate the potentiality of marrow stromal cell(MSCs) as seed cell in the regeneration of tissue engineered cartilage, formation of cartilage nodules by culture expanded MSCs pellets under the induction of TGF-beta was investigated.

METHODSMSCs were cultured and expanded in vitro. Cell pellets containing 1 x 10(6) MSCs were obtained by centrifuging MSCs solution at 1,000 r/min in 5 ml centrifugation tube. Pellets were exposed to cell culture media containing 20 ng/ml TGF-beta for 7 days and then cultured for another 7 and 21 days. The nodules were moved out of the tube and cartilage formation was observed by stereomicroscope, light microscope and electronic microscope.

RESULTS10 days after exposure to TGF-beta, pellets contracted and formed small and round nodules on the bottom of the tubes. The nodules grew bigger slowly and reached maximal diameter of 1.8 mm in 28 days. The surface of the nodules was smooth and bright white. Histological examination showed that extra cellular matrix formed in 14 days and in some areas cells situated in lacuna. In 28 days' specimens, a lot of cells situated in lacuna could be observed and the histological appearance looked much similar to cartilage. Electronic microscope observation demonstrated that in 28 days' specimens a large amount of collagen fiber existed.

CONCLUSIONUnder the induction of TGF-beta, MSCs could differentiate into chondrogenesis cell and form cartilaginous nodules in vitro. This indicated that MSCs could be the potential seed cells in the regeneration of cartilage employing method of tissue engineering.

Animals ; Bone Marrow Cells ; cytology ; metabolism ; Cartilage ; cytology ; Cell Differentiation ; Cell Separation ; Cells, Cultured ; Chondrogenesis ; drug effects ; Rabbits ; Stromal Cells ; cytology ; metabolism ; Tissue Engineering ; Transforming Growth Factor beta ; pharmacology

OBJECTIVETo examine the effect of aqueous extracts of Scutellaria baicalensis Georgi and Radix paeoniae Alba on periodontitis mice and compare the results of the two herbs for the treatment of the periodontitis mice.

METHODSSixty-four SPF 12-week-old male Kunming mice were selected and randomly divided into four groups:Control group(C); Experimental periodontitis group (P):the peridontitis models in Kunming mice were prepared by wrapping silk ligature and inoculating with putative periodontopathic bacteria; Scutellaria baicalensis Georgi treatment group (SG): periodontitis was induced by the same method described above, the mice were gavaged with Scutellaria baicalensis Georgi; Radix paeoniae Alba treatment group (RG): periodontitis was induced by the same method described above, the mice were gavaged with Radix paeoniae Alba.Four mice were sacrificed at each time point of the end of 4, 6, 8 and 10 weeks in each group. The histopathological changes of periodontal tissue were observed under microscope with HE staining. The level of serum IgG1 and IgG2a was measured by enzyme-linked immunosorbent assay (ELISA) .

RESULTSA serious inflammatory response, alveolar progressive absorption and a large number of osteoclasts were observed in the experimental periodontitis group.However, in SG and RG, the inflammation of the periodontal tissue was decreased and tissue repair was significant. The level of serum IgG2a in SG (6 week:0.934 ± 0.006, 8 week:0.743 ± 0.009, 10 week: 0.674 ± 0.008) and RG (6 week: 1.023 ± 0.032, 8 week: 0.851 ± 0.032, 10 week:0.790 ± 0.009) was significantly decreased after the mice were gavaged with the two herbs(P < 0.01). The level of serum IgG2a in SG was significantly lower than that of RG (P < 0.01). The level of serum IgG1 in SG (6 week: 0.314 ± 0.006, 8 week: 0.344 ± 0.004, 10 week: 0.367 ± 0.006) and RG (6 week: 0.287 ± 0.005, 8 week: 0.303 ± 0.058, 10 week: 0.336 ± 0.006) were significantly increased (P < 0.01). The level of serum IgG1 in SG was significantly higher than that of RG (P < 0.01).

CONCLUSIONSBoth the aqueous extracts of Scutellaria baicalensis Georgi and Radix paeoniae Alba showed therapeutic effect on periodontitis in mice.Scutellaria baicalensis Georgi was more effective than Radix paeoniae Alba.

Aconitum ; Animals ; Immunoglobulin G ; metabolism ; Male ; Mice ; Paeonia ; Periodontitis ; metabolism ; Plant Extracts ; pharmacology ; Scutellaria baicalensis ; Water

Objective: To study the sedative efficacy and safety of nitrous oxide (N2O ) inhalation combined with oral midazolam in children with impacted supernumerary teeth for extraction under sedation and to provide a reference for the selection of anesthetic methods for children undergoing impacted teeth extraction. Methods : Sixty patients aged 5-10 years with maxillary impacted supernumerary teeth were randomly divided into three groups, with 20 in each group, as follows: the N2O group: N2O inhalation sedation before the operation; the midazolam group: oral midazolam sedation before the operation; the combination group: N2O inhalation combined with oral midazolam sedation before the operation. Sedation was performed before extraction under local anesthesia. The Ramsay sedation effect, Houpt behavioral score and incidence of adverse reactions were evaluated after the operation. Results: The Ramsay sedation scale score was significantly higher in the combination group (2.75 ± 0.55) than in the N2O group (2.30 ± 0.47) and the midazolam group (2.40 ± 0.50) (P ＜0.05). Similarly, the Houpt behavioral rating scale score was significantly higher in the combination group (5.25 ± 0.64) than in the N2O group (4.70 ± 0.73) and the midazolam group (4.80 ± 0.69) (P ＜0.05). The adverse reaction rate was lower in the combination group (5%) than in the N2O group (10%) and the midazolam group (10%), but the difference was not significant (χ2=0.436, p=0.804). Conclusion N2O inhalation combined with oral midazolam sedation in the extraction of impacted supernumerary teeth in children can significantly improve the sedative and therapeutic efficacy and is a safe and effective sedation method.

Objective : To investigate possible functional disorders of central auditory processing and language in school-age children with cleft palate through an assessment of the characteristics of the P300 and N400 event-related potentials (ERPs). Methods : This study included 28 school-age children with cleft palate, aged 6 to 12 years, and 30 children without cleft palate as a control group. The P300 and N400 ERPs were selected as indexes of the central auditory processing and language functions of children in both groups. The data were statistically compared between the two groups. Results : Compared with the controls, the children with cleft palate showed a significantly prolonged P300 latency (331.73 ± 14.94 ms vs. 348.64 ± 14.66 ms, P < 0.05) and a significantly decreased P300 amplitude (13.47 ± 2.24 μV vs. 12.07 ± 2.46 μV, P < 0.05). Similarly, the N400 latency of children with cleft palate was significantly prolonged compared to that of controls (431.07 ± 17.90 ms vs. 408.23 ± 18.04 ms, P < 0.05), and the N400 amplitude was significantly decreased compared to that of controls (13.75 ± 2.12 μV vs. 15.17 ± 2.34 μV, P < 0.05). Conclusion School-age children with cleft palate may have central auditory processing disorders and language dysfunctions.