BACKGROUND: Revascularization is necessary for tissue-engineered bone implantation by osteogenesis to effectively repair bone defect.OBJECTIVE: To evaluate marrow mesenchymal stem cells (MSCs) modified by bone morphogenetic protein 2 (BMP-2) in combination with polylactic acid/polycaprolactone (PLA/PCL) to repair rabbit radial bone defect during the vascularization, and to investigate the promotive effects of BMP-2 gene on the vascularization of bone graft.DESIGN: Randomized controlled animal study.SETTING: This study was performed in the Central Laboratory of China Medical University from January to December 2005.MATERIALS: PLA/PCL with 150-250 μm pore diameter and 90% interval porosity was provided by Changchun Applied Chemistry Institute, Chinese Academy of Science. Sixty 3-month-old New Zealand rabbits were selected in this study.METHODS: Sixty rabbits were randomly divided into four groups with 15 rabbits in each group. Subsequently, middle segments of bilateral radial bone were obtained to establish 1.5-cm bone defect models that were implanted with processed artificial bones. Adenovirus carrying BMP-2 (AD-BMP-2) group: Artificial bones were processed with transfected BMP-2 cells plus PLA/PCL; Control group: Artificial bones were processed with adenovirus carrying β-gal gene (Ad-Lacz) plus PLA/PCL; Non-transfection group: Artificial bones were processed with non-transfected cells plus PLA/PCL; PLA/PCL group: PLA/PCL alone for transplantation.MAIN OUTCOME MEASURES: Four, eight, and twelve weeks after surgery, X-ray was used to observe new bone formation; stereoscopic microscope to observe distribution of microvessels; haematoxylin-eosin staining to detect the relationship between microvessels and bone formation; transmission electron microscope to investigate the correlation between osteoblasts and vascular endothelial cells, detect vascular endothelial growth factor expression, and calculate the number of microvessels.RESULTS: Four postoperative weeks in the AD-BMP-2 group, numerous microvessels were observed; stent pore was full of cartilage calluses; active osteoblasts grew around microvessels; vascular endothelial growth factor expression and numbers of microvessels were higher and more than those in other groups. Eight postoperative weeks, osteoblasts gradually increased in the bone graft; microvessels circuitously expanded and connected each other; cartilage callus changed into trabecular bone. Twelve postoperative weeks, cortical bones were successive; medullary cavity recanalized; microvessels longitudinally arranged in order. Ability of bone formation in the control group and non-transfection group was weak, and vascular regeneration was slow; 12 postoperative weeks, bone defect was primarily repaired; microvessels were distributed along the pores of newborn bone trabecula. Newborn vessels were hard found in the PLA/PCL group at each time point. Twelve postoperative weeks, bone extremities sclerotized, and defect regions were fully filled by fiber tissues.CONCLUSION: Transfected BMP-2 gone by up-regulating vascular endothelial growth factor expression can indirectly induce vascularization of bone graft, promote survival of seed cells, and accelerate bone formation.

BACKGROUND: Tissue engineered bone constructed in vitro is a compound of cell and material; additionally, revascularization plays a key role in effectively repairing bone defect after transplantation of tissue engineered bone.OBJECTIVE: To evaluate the influence of antigen-extracted bovine cancellous bone stent combining with bone morphogenetic protein 2 (BMP-2) on vascularized reaction during reparative process of bone defect.DESIGN, TIME AND SETTING: Randomized grouping design and controlled animal study, which was performed at the Central Laboratory, China-Japan Friendship Hospital Affiliated to Jilin University.MATERIALS: Sixty rabbits of clean grade were selected in this study. Superior cancellous bone of bovine humerus was used to establish bovine cancellous bone stent. Recombinant adenovirus carrying human BMP-2 (Ad-BMP-2) and β -galactosidae gene (Ad-Lacz), and recombinant human BMP-2 (rhBMP-2) were graciously presented by Dr. Oliver and Pro. Gao, Department of Pathology of Jilin University.METHODS: Marrow mesenchymal stem cells were extracted from 60 rabbits, and then they were transfected with BMP-2 adenovirus vector to repair 1.5-cm defects of radial bone of both upper extremities by combining with bovine cancellous bone transplantation. Rabbits were randomly divided into 5 group with 12 in each group: Ad-BMP-2 transfected cells+bovine cancellous bone group, non-transfected cells+rh-BMP-2+bovine cancellous bone group, Ad-Lacz transfected cells +bovine cancellous bone group, non-transfected cells + bovine cancellous bone group, and bovine cancellous bone group. Transplanted bone was fixed by tightly suturing tunica muscularis and anadesma.MAIN OUTCOME MEASURES: New bone formation was observed by X ray at 4, 8, and 12 weeks after surgery; microvascular ink perfusion was used to observe vascular distribution; transmission electron microscope was used to observe osteoblasts and vascularization; hematoxylin-eosin (HE) staining, alcian blue staining, and VonKossa staining were used to observe correlation between microvessels and bone formation; immunohistochemical staining of vascular endothelial growth factor was used to detect gray value; immunohistochemical staining of CD34 was used to specifically label vascular endothelial cells for microvascular amount.RESULTS: Sixty rabbits were included into the final analysis. X-ray and immunohistochemical examinations demonstrated that bone formation and vascularization in the Ad-BMP-2 transfected cells+bovine cancellous bone group and non-transfected cells+rh-BMP-2+bovine cancellous bone group were superior to those in other three groups. After four weeks, microvascular ink perfusion indicated that a branch of small vessels was formed in pore of trabecular bone. Vascular density was higher in the peripheral domains but lower in the central regions. Transmission electron microscope suggested that a lot of osteoblasts and new vascular buds with active function were observed four weeks after surgery. Mature lamellar bone was formed 12 weeks after surgery, and structure of new vessels was complete. Detection of vascular endothelial growth factor expression and microvascular amount indicated that content of vascular endothelial growth factor in the Ad-BMP-2 transfected cells+bovine cancellous bone group was significantly higher than that in other four groups (P<0.01), and microvascular amount was also significantly higher than that in other four groups (P<0.01).CONCLUSION: BMP-2 gene can indirectly induce vascularization of transplanted bone through up-regulating vascular endothelial growth factor expression, which is superior to rh-BMP-2.

BACKGROUND:The incorporating of zeolites or porous fillers into polymer membranes can improve the pervaporation separation properties of membranes.But the effect mechanism of zeolites or porous fillers on membrane properties needs to be further studied.OBJECTIVE:The study was designed to prepare ZSM-5 zeolite incorporated chitosan membrane by solution blending method to investigate the effecIs of zeolite on membrane pervaporation properties.DESIGN:A controlled observation.SETTING:Dalian Institute of Chemical Physics,Chinese Academy of Sciences.MATERIALS:This study was performed at the Laboratory of New Type Membrane Separation Technology,Dalian Institute of Chemical Physics,Chinese Academy of Sciences in May 2006.Chitosan,with deacetylation degree of 75%-85%,was obtained from Sigma-Aldrich Chemical Company,USA;Dimethyl carbonate(DMC),with purity of 99%,was purchased from Fluka Chemical Company,USA:ZSM-5 zeolite was kindly supplied by Dalian Institute of Chemical Physics,Chinese Academy of Sciences,China;Methanol,with purity＞99.5%,were purchased from Shenyang Lianbang Chemical Company,China.METHODS:ZSM-5 zeolite incorporated chitosan membranes were prepared by solution blending method.properties.RESULTS:Scanning electron mieroscope demonstrated that zeolite was uniformly distributed in the membrane matrix and the membranes were free from possible defects.The separation selectivity of dimethyl carbonate(DMC)/methanol mixtures was dominated by solubility selectivity rathcr than diffusivity selectivity.Swelling degree increased and the permeation flux of the membranes increased significantly with the zeolite content increasing.From the temperature-dependent permcation values,the Arrhenius activation parameten were estimated.CONCLUSION:The pervaporation results indicated that the membranes incorporated with the ZSM-5 zeolite exhibited better separation properties for DMC/methanol mixtures comparing with homogeneous chitosan membranes.

Objective To study the mechanism of male infertility. Methods Forty sperms from 8 normal males as control and 60 sperms from 12 males with infertility were observed by SEM.The ultrastructure of acrosomes was analyzed and compared. Results Spermatozoa with obscure ringed rips in infertile group acounted for 66.7%(40/60),serrate 65.0%(39/60);but in control group,the proportions were 10.0 % (4/40) and 5.0%(2/40),respectively.The ratios of acrosome to head in infertile group were ( 70.0 ?8.0)%,greater than controls (57.7?6.4)%.The ratios of acrosome membrane which was not intact were 70.0%(42/60) in infertile group and 22.5%(9/40) in control group.Acrosomes with rough surface were 68.3%(41/60) and 20.0%(8/40) respectively in the 2 groups;Acrosomes with particles adhesive to the surface were 65.0%(39/60) and 27.5%(11/40) respectively. Conclusions Abnormal acrosome structure is one of the causes of male infertility.

Objective To build the screening model for population with Impaired Glucose Regulation (IGR)in community, and to evaluate its validity by using the model in general population. Methods Based on the epidemiological survey of DM in the community population in 2006, the analysis of the risk factors and the risk factors scoring method were used to build the screening model for IGR in community which was then used to screen for IGR in 2 120 general population in community to evaluate its validity. Result When the screening model was built with the accumulative score of risk factors ≥5, the sensitivity and specificity for identifying undiagnosed IGR were 68.2% and 61.7%, Youden's index was 0.299 and the positive predictive value was 14.2%. When 2 120 general population used the screening model, only 974 (45.9% of them)had to take OGTT test, and 124 (68.9%) IGR were identified. Conclusion The screening model with the accumulative score of risk factors ≥5 is an easy, effective and economic tool for IGR screening, and it can be tried to use in the screening for IGR in community, further research is needed.

Objective: To investigate the cause of complications after naloxone (Nal) for administration analepsia of general anesthesia. Method: Thirty-six cases were randomly divided into group Ⅰ (n=12, Nal 0.004mg?kg~(-1)), group Ⅱ (n=12,Na1 0.002mg?kg~(-1)) and group Ⅲ (n=12,NS). The dosage was administrated intravenously in a bolus at the end of operation. The venous blood samples were taken respectively before anesthesia (T_1),Smin before and after the administration (T_1 ,T_3) to measure the plasma concentration of E and NE with high performance liquid chromatography,and those of A Ⅱ, ET and ANP with radioimmunoassay. The complications after the administration were observed. Result: Compared with T_1 and T_2, the plasma concentrations of A Ⅱ, E and NE obviously increased at T_3 in group Ⅰ and group Ⅱ (P

Objective The effect of oral L-Dopa on healing of the experimental mandibular defect of rabbits was studied.Method 52 rabbits were assigned randomly to experimental group and control group.After bone defect being made on mandible,rabbits had been given with L-Dopa in experimental group.Healing bone samples were adopted at 14,21,30,42,49 days after operation,observed x-ray and histological changes and calculated out the bone histomorphometric parameters.Results X-ray inspection indicated that bone defect of the experimental group had completed callus union from 30th day.But,a part of the defect of control group did not appear callus union radiologically.Histological examination had the same result.Bone histormorphometry examination exhibited that there was a significant difference between TBV of the experimental and the control group(P

Objective To study the clinical characteristics in young women with breast cancer.Methods Clinical data on 71 young breast cancer cases (under 35 years) out of a total 810 female cases during a period of 20 years were retrospectively analyzed. Result Delayed medical consultation was more often seen in young patients(56?4)?d vs (35?3)?d; u=2.33; P

Objective To investigate the effects of myopia on first-order kernels six ring responses of multifocal electroretinogram (mfERG). Method We continuously selected 80 subjects aged from 13 to 20 year-old and divided four groups into normal, mild myopia, moderate myopia and high myopia. Each group had 20 subjects that were examined with mfERG of 103 stimuli locations. The amplitude and latency of N1, P1, N2 waveforms of six-ring first-kernel responses in mfERG were analyzed. Result With increasing of myopia degree, the response density of N1, P1, N2 waveforms of six-ring first-kernel responses in mfERG was decreased gradually (all P0.05). Conclusion Myopia can decrease the response density of first-order kernels six ring responses of mfERG, which is very important to determine the abnormality of mfERG in the clinic.

Objective To identify the influencing factors for pediatric nursese' reporting of adverse events at 3A hospitals in Beijing. Methods Adopting the random sampling of ten 3A hospitals with pediatric wards in Beijing and conducting an questionnaire survey of some nurses in those hospitals. Results The possibility of adverse events reporting increased with the awareness of adverse events which was related with their severity. Except for title, educational background, length of service, position and past experiences were not associated with the barriers. The major perceived barrier was fear of colleague relationship brokenup and some other undesirable consequence. Conclusions Better training of awareness of adverse events and changes of the punitive culture by the roots as well as some regulation or policy were the major solutions to improve incident reporting.