Objective To culture the osteoblast of Wistar rat in vitro and study its biological characteristics. Methods With heat-cool alternative method and by way of the trysin digestion, the osteoblast cells, obtained from femoral bone of Wistar rats, were colleced and cultured with special cultural fluid in vitro. After about two weeks, cells lined up in one layer. Then cells were generationed and examined by phase contrast microscope, H E strain, ALP strain, type Ⅰ and type Ⅲ collagen strains. Results The cells had the same morphological feature with ALP activity, type Ⅰ collagen strain positive. Conclusion The cultured osteoblasts derived from bone mass were seed cells for the bony tissue engineering, which is the base for the tissue-engineering born construction in vitro.

Objective:To compare the fracture resistance of roots of mandibular premolar with different apical preparation diameters.Methods:Sixty single-rooted single canal permanent mandibular premolar teeth extracted newly for orthodontic reason without immatureness,fracture or cracks were selected,with a curvature less than 10°,and internal length:short diameter of less than 2 at a level 5 mm from the apex.All the teeth were decoronated,leaving roots 13 mm in length.The initial apical file size for the teeth was ≤ 15#.The roots were assigned to 6 groups based on weights with random block design.Group A:blank control group,no instrumentation was performed.Groups B-F:the master apical file (MAF) was 40#,45#,50#,55# and 60#,respectively.In the five experimental groups the roots were instrumented using hand files with step-back technique at 1 mm increments,resulting in a taper of 0.05.The irrigant used was distilled water.After mounted in acrylic resin,all the teeth were subject to vertical loading using an Instron testing machine until fractured.The occurrence of fractures was detected when the applied load suddenly decreased.The fracture load values and fracture modes were recorded.Oneway ANOVA and post-hoc Tukey test were used to determine the difference of fracture load values between the groups (P ＜ 0.05).Chi-square tests were used to compare the modes of root fracture.Results:Five experimental groups exhibited lower fracture load values than that of control group [(1 444 ± 155) N].The mean fracture load values for roots instrumented to an apical diameter of 50# [(1 027 ± 128) N],55# [(994 ± 150) N] and 60# [(983 ± 166) N] were significantly lower than that of control group and 40# group [(1 339 ± 131) N] and 45# [(1 287 ± 144) N] (P ＜0.05).Buccal-lingual fracture,mesio-distal fracture and compound fracture occurred 55％,13％ and 32％,respectively.No difference of fracture mode was detected in the six groups.Conclusion:The fracture resistance reduced significantly when the roots were instrumented to an apical diameter of 50# or larger.

OBJECTIVE:To establish HPLC fingerprint sectrum of Rhaponticum uniflorum. METHODS:HPLC was performed on the column of Hypersil-ODS with mobile phase of 0.3% phosphoric acid-acetonitrile(gradient elution) at flow rate of 1.0 ml/min,detection wavelength was 220 nm,column temperature was 30 ℃ and volume injection was 10 μl. The luteolin was refer-ence,17 batches of R. uniflorum from different production places was analyzed and similarity evaluation system for chromatograph-ic fingerprint of TCM (2004 A edition)was adopted for the similarity analysis. RESULTS:There were totally 11 common peaks with similarity degree≥0.900 of 17 batches. According to the verification,the fingerprint spectrum and reference fingerprint spec-trum of R. uniflorum had good consistency. CONCLUSIONS:The established method is specific and stable,and can provide refer-ence for the identification and quality control of R. uniflorum.

BACKGROUND:With the development of surgical techniques and endovascular treatment techniques, the therapeutic efficacy on arteriosclerosis obliterans of the lower limbs has been improved greatly. As the long-term prognosis is stil not clear, how to treat arteriosclerosis obliterans of the lower limbs is stil a problem for vascular surgery. OBJECTIVE:To observe the long-term clinical efficacy of autologous bone marrow stem cel transplantation in the treatment of arteriosclerosis obliterans of the lower limbs. METHODS:Thirty-nine patients with arteriosclerosis obliterans who had undergone autologous bone marrow mesenchymal stem cels (totaly 56 times of cel transplantation) from September 2007 to July 2013 were enroled in this study. As of February 2015, the folow-up time was 7.5 years. After treatment, regular telephone folow-up about limb pain, cold sensation, intermittent claudication distance, resting ankle-brachial index and limb ulcer size and depth was done annualy; at 1 year after treatment, limb arteriography and venous blood gas analysis were reviewed. RESULTS AND CONCLUSION: Of the enroled 39 patients, 4 patients were subjected to amputation because of poor efficacy, 2 patients died of acute myocardial infarction, and 2 patients died of not timely amputation. There were 31 patients who had been folowed up for over 3 years. After treatment, the resting ankle-brachial index and limb ulcer size and depth limb pain were both improved significantly. There were significant differences in 1-year limb blood oxygen partial pressure and oxygen saturation before and after treatment, and the postoperative number of capilaries also increased significantly. These findings indicate that autologous bone marrow stem cel transplantation is a safe treatment for arteriosclerosis obliterans of the lower limbs with better and stable long-term curative effects. This method is a good choice for patients who have poor blood vessels and poor efficacy of traditional methods.

Objective The experiment aims at probing the best condition of the isolation and purification of rat islets.Methods The islets were isolated from rat pancreas by hepatopancreatic duct perfusing with collagenase and purified with Ficoll 400 discontinuous density gradient centrifugation.Then the purified islets were subjected to histological staining,electron microscopy and radioimmunoassay for identification of specificity and viability.Results The histological staining revealed that the viability and the purity of the purified islets were above 95％and 85％respectively.Electron microscopy showed that the purified islets were morphologically intact with clear membrane and plenty of secreting granules.Radioimmunoassay demonstrated the secreted insulin concerntration between low-glucose groups and high-glucose groups varied significantly,which verified the good function of the islets.Conclusion Hepatopancreatic duct perfusing with collagenase is a good method for digestion.There aye many factors that influence the quantity and quality of the acquired islets,such as the completed expansion of pancreas,the concentration and viability of collagenase and the digested time,etc.

Objective To observe the changes in plasma C type natriuretic peptide(CNP) and C reaction protein(CRP) levels and the preventive effect of exogenous CNP on vascular stenosis in a diabetic rabbit model after femoral artery injury.Methods After setting up an animal model of diabetes,the rabbits were divided into the control group(n=8),artery injury group(n=8) and CNP treatment group(n=8).Enzyme-linked immunosorbent assay was used in determination of plasma CRP and CNP concentration.Histological changes in the femoral artery wall were evaluated by HE staining to determine the degree of stenosis.Results The post operative CRP concentration of the artery injury group compared with CNP treatment group was 13.81?4.30 ?g/mL vs 8.43?0.61 ?g/mL(P

Objective To analyze neural activity of in rat prefrontal cortex with the use of nonnegative matrix factorization with sparseness constrains (NMFs) as a methodology and to study how to express neural ensemble with higher precision during working memory task.Methods Experiment data were obtained from neural population activity in the period 5 s before and after the working memory event.From the zero point,the neuronal firing times were binned in windows of 200 ms with 50 ms overlapping.The normalized neuronal bin-count matrix is decomposed by NMFs into mixing matrix and source component matrix with sparseness constraints.Meaningful components were extracted to reconstruct the input by an inverse of NMFs transform.Results By analyzing the ten groups of data from 2 rats,with the numbers of the sparse sources of 10 and 15 respectively,explicit neural ensembles with the feature components were obtained in the sparse reconstructed activity.Comparing to rate coding,the spatiotemporal location of neural ensemble was more precisely detected.Conclusion The working memory information is encoded with neural ensemble activity.NMFs could find the sparse firing pattern robustly in neuron population activity.NMFs removes much redundancy and demonstrate the possibility to express neural ensemble with higher precision compared with rate coding,which would be helpful to infer correlations between cortical firing pattern and working memory event.

Objective The construction of the reconstructed acellular extracellular matrix(REAECM) of bone and preliminary investigation of biocompatibility of REAECM was performed to supply the experimental basis for the extracellular scaffold of bone tissue engineering. Methods Applying the technique of culture in vitro, biocompatibility of the REAECM cultured with osteoblasts was observed using phase-contrast microscope and scanning eletron microscope at 1-4 weeks. Results The osteoblasts could attach and proliferate, even grow well into the foam of REAECM.Conclusion REAECM is an excellent scaffold material for bony tissue engineering construction, which pocesses a morphological structure of three-dimensional foam. The REAECM showed a good biocompatibility with osteoblasts co-cultured in vitro. There was prospective signs of REAECM to the attachment, proliferation of the osteoblasts

Objective The experiment aims at probing the best condition of the isolation and purification of rat islets. Methods The islets were isolated from rat pancreas by hepatopancreatic duct perfusing with collagenase and purified with Ficoll 400 discontinuous density gradient centrifugation.Then the purified islets were subjected to histological staining,electron microscopy and radioimmunoassay for identification of specificity and viability. Results The histological staining revealed that the viability and the purity of the purified islets were above 95% and 85% respectively.Electron microscopy showed that the purified islets were morphologically intact with clear membrane and plenty of secreting granules.Radioimmunoassay demonstrated the secreted insulin concerntration between low-glucose groups and high-glucose groups varied significantly,which verified the good function of the islets.Conclusion Hepatopancreatic duct perfusing with collagenase is a good method for digestion.There are many factors that influence the quantity and quality of the acquired islets,such as the completed expansion of pancreas,the concentration and viability of collagenase and the digested time,etc.

Objective To observe the influence of insulin resistance(IR) and isosorbide mononitrate(ISMN) on myocardial cellular apoptosis in spontaneously hypertensive rats (SHR) .Methods Forty male 14‐week old Wistar(W) rats and SHR(S) each were respectively or jointly fed with normal diet (ND) ,high fat and high glucose(HFHG) diet ,normal saline(NS)and ISMN by ga‐vage .Then they were randomly divided into the normal and NS group (normal W and normal S ) ,HFHG and NS group(HFHG W and HFHG S) ,normal and ISMN group(ISMN W and ISMN S) ,HFHG and ISMN group(HI W and HI S) ,with 10 rats in each group .After 12‐week feeding ,carotid arterial blood was collected for detecting blood glucose concentration and insulin level and cal‐culating insulin resistance index (HOMA‐IR);4 myocardial tissue samples were taken for respectively observing the morphology under microscope ,and detecting the NO level ,myocardial Bcl‐2 ,Bax gene and their protein expression levels in myocardial tissue . Results Myocardial NO level ,Bax gene mRNA and related protein levels in the HFHG and ISMN intervention groups were higher than those in the normal group ,while the bcl‐2 gene mRNA and related protein expression were on the contrary ;myocardial tissue NO level ,Bax gene mRNA and related protein expression in the S groups were increased compared with the corresponding W groups ,while the bcl‐2 gene mRNA and related protein expression were on the contrary ;in the HFHG W group ,the myocardial tis‐sue NO level had significantly positive correlation with HOMA‐IR ,and in the ISMN W group ,HOMA‐IR was positively correlated with the NO level in the myocardial tissue .Conclusion Myocardial cellular apoptosis of SHR is increased compared with Wistar rats ;both IR and ISMN can aggravate the apoptosis of SHR myocardial cells ,moreover IR has a mutual induction and reciprocal causation with ISMN .