Objective To investigate the best digestion time for rabbit rib cartilage cells separation by collagenase Ⅱ diges‐tion method .Methods Rabbit cartilage tissue was taken from 3‐month‐old New Zealand white rabbits ,and then digested in 0 .2%collagenase Ⅱ solution for 4 ,8 ,12 ,16 and 20 h under vibration at 37 ℃ ,respectively .The corresponding experiments were named as group A ,B ,C ,D ,and E .The obtained primary cells were cultured and passaged after counting .The cell morphology ,proliferation rate ,secretion of extracellular matrix of passage 2 cells were compared to chose the best digestion time .Results The primary chon‐drocytes obtained in group C ,D and E were more than the other two group A and B .The chondrocytes cytoactive in group C and D were better than the other three group A ,B and E .The passage 2 chondrocytes in group C ,D had better secretion of extracellular matrix capability than the other three groups .Conclusion The best collagenase Ⅱ digestion time is 12 to 16 h ,at this digestion time period ,more primary chondrocytes with high cytoactive and strong proliferation capability can be obtained ,and the phenotype of their passage 2 cells is quite good .

Objective To construct a novel tissue?engineered bone matrix gelatin (BMG)/poly[butylene succinate?co?tere?phthalate] (PBST) biphasic scaffold for annulus fibrosus. Methods The PBST spinning fibers were prepared by electrospinning and the porosity and water absorption rate were tested. Rabbit annulus fibrosus cells were isolated, cultured and identified through SafraninOstaining, and collagenⅡimmunohistochemical staining in vitro. And then annulus fibrosus cells were implanted on the PBST fiber, whose growth situation was observed by scanning electron microscope (SEM). Then the BMG/PBST biphasic scaf?fold was constructed by BMG as the outer annular fibrosus and PBST fiber as the inner annular fibrosus. The annulus fibrosus cells were implanted on the biphasic scafflod and cultured for 3, 7 and 21 days in vitro. The biomechanical and biological property was observed at the predetermined time point. Results The porosity of the fiber was 61.83%±7.33%and its water absorption rate was 297.34%± 57.13%. The identified result of annulus fibrosus cells were positive, suggesting that the cells have still kept their annulus fibrosus cells characteristics. The cells growth could be observed through SEM at 3rd and 7th day after implanted on the fi?bers. After cultured on the BMG/PBST scaffold, HE staining proved that the cells could ingress into the inner of fiber with time. SafraninOstaining and collagenⅡimmunohistochemical staining proved that the cells can secreted abundant proteoglycan and collagenⅡ, the special annulus fibrosus cell extracellular matrix. Compared with the BMG/PBST scaffold without cells, the elastic modulus of biphasic scaffold was increased from 14.83±1.02 MPa to 17.56±1.47 MPa after cultured with cells for 21 days in vitro. Conclusion The novel tissue?engineered biphasic scaffold for annulus fibrosus constructed with BMG and PBST fiber spinning has good cytocompatibility and biomechanical characteristics, which provide a basis for the complete tissue engineered interverte?bral disc.

BACKGROUND:Tissue-engineered intervertebral disc has provided a new biological therapeutic approach for intervertebral disc degeneration. Tissue-engineered annulus fibrosus is one key step of constructing a complete tissue-engineered intervertebral disc. OBJECTIVE:To sum up the research progress of tissue-engineered annulus fibrosus from the folowing aspects: structural features, scaffold materials, seed cels. METHODS:PubMed database and Wanfang database (2000-2015) were retrieved by the key words of “tissue engineering, intervertebral disc, annulus fibrosus, seed cel, scaffold, construction” in Chinese and in English, respectively. According to inclusion and exclusion criteria, 48 literatures were involved for summarization. RESULTS AND CONCLUSION: Previous studies about tissue-engineered annulus fibrosus only focused on cel adhesion, proliferation and extracelular matrix secretion on the scaffold. Currently, tissue-engineered annulus fibrosus exhibit similar features to the natural annulus fibrosus in the folowing aspects: cel function, tissue structure and mechanical features, and relevant animal experiments have achieved certain results in animal experiments. However, it is stil difficult to build a tissue-engineered annulus fibrosus entirely similar to the natural one, and we need to further improve scaffold materials, culture conditions, colection of seed cels. The current strategies of annulus fibrosus construction stil focus on single phase of scaffold, and the biphasic scaffold and complete intervertebral disc scaffold wil be the trend of the researches. Technology of induced differentiation of stem cels provides a broach source of seed cels for tissue-engineered annulus fibrosus.

Objective To study the methods and effects by using thrombolytic catheter in interventional treatment for patients with acute lower limb arterial thrombosis or embolism. Methods One hundred and twelve patients suffered acute lower limb arterial thrombosis or embolism. There were 85 cases of acute lower limb arterial embolism induced by atrial fibrillation in coronary or rheumatic heart disease,other 27 cases of arterial thrombosis caused by different reasons. Interventional treatment by inlying thrombolytic catheter was applied and continuous perfusion was received locally in all patients. Results Complete recanalization was got in 77 cases (68.8%) of 112 cases. Partial re canalization was got in 23 cases (20.5%), and ischemia limbs were saved in spite of chronic limb ischemia(chronic spasmodic limb) occurring in the later follow-up. Nine cases (8.0%) were amputated as a result of irreversible limbs necrosis, 3 cases (2.7%) died from acute renal failure resulting from reperfusion injury or recurrent cerebral embolism.Conclusion Interventional treatment by inlying thrombolytic catheter is a safe and effective method with lower amputation rate for acute lower limb arterial thrombosis or embolism in patients.

Objective To fabricate a novel tissue-engineered cartilage with adipose-derived stem cells (ADSCs) seeded on the chitosan hydrogel scaffold to repair articular cartilage defect.Methods Adipose tissue and costal cartilage were harvested from New Zealand rabbits,and ADSCs in passage one and chondrocytes were obtained after the samples were digested and cultured in vitro.ADSCs were digested,suspended,seeded onto the sterile chitosan gel,and cultured in vitro for 1 week to fabricate the tissue-engineered cartilage.The defects were respectively filled with the tissue-engineered cartilage (composite group),chondrocyte suspension (cell group),chitosan gel (material group) and nothing at all (control group).At postoperative 12 weeks,cartilage repair was evaluated using the gross examination,histological staining,immunohistochemical staining and international cartilage repair society (ICRS) histological score.Results Effect of cartilage repair in composite group was significantly better compared to other groups.The regenerated tissue in composite group seemed tightly bound in normal tissue,with similar structure and extracellular matrix secretion.ICRS histological score in composite group was (13.89 ± 0.14) points,which differed significantly from (7.06 ± 0.19) points in control group,(7.14 ± 0.22) points in cell group and (7.46 ± 0.26) points in material group (P ＜0.01).Conclusion The tissue-engineered cartilage with ADSCs seeded onto the chitosan hydrogel is effective for repair of articular cartilage defect.

Objective To design a kind of nasal feeding nutritional tube that can carry 125I particles,to use this tube for the treatment of upper digestive tract malignant occlusive disease in order to achieve double effect of nasal feeding nutrition and brachytherapy.Methods 125I particles were put into a 3F catheter,then both ends of the catheter were sealed off to make 125I particle chain.By using binding technology,the 125I particle chain was fixed on the nasal feeding tube.Under DSA guidance,the nasal feeding tube carrying 125I particle chain was inserted into the esophagus,with the 125I particle chain segment crossing over the section of esophageal stenosis or occlusion to conduct brachytherapy.This technique was employed in 6 patients with advanced esophageal carcinoma.The technical success rate,operation time and complications were recorded.Two months after the treatment,the Karnofsky score,visual analogue scale (VAS) pain score,Neuhaus dysphagia grading,esophagus patency on esophageal radiography,and local tumor control rate were determined.Results The preparation of nasal feeding nutritional tube carrying 125I particle chain was simple.The technical success rate was 100％,the mean operation time was 15.5 min,no serious complications such as bleeding or infection occurred.Two months after the treatment,the Karnofsky score,VAS pain score and Neuhaus dysphagia grading were significantly improved when compared with the preoperative data (P＜0.O1).On esophageal radiography,the contrast agent passed through the narrow area smoothly.Partial remission (PR) of local tumor was obtained in all patients,and the local tumor control rate was 100％.The patients were followed up for 2-6 months,one patient developed recurrent obstruction.Conclusion It is simple and easy to prepare a nasal feeding nutritional tube carrying 125I particle chain,the use of this kind of tube can achieve both parenteral nutrition and brachytherapy at the same time.Therefore,this technique opens a new way for the treatment of esophageal malignant tumor.

Objective To design a new integrated portable biliary internal-external drainage catheter carrying125 I seeds used for the treatment of malignant biliary obstruction lesions so as to achieve the dual curative effects of biliary drainage and brachytherapy. Methods A total of 15 patients with malignant obstructive jaundice, who were admitted to the First Affiliated Hospital of Zhengzhou University, China, during the period from September 2016 to January 2018, were enrolled in this study. Biliary stent implantation was performed in all patients, which was followed by insertion of a new integrated portable biliary internal-external drainage catheter carrying125 I seeds. The technical success rate, clinical success rate, complications, stent patency time and patient survival rate were evaluated. Results The placement of the drainage tube was simple and smooth, and the technical procedure was successful in all patients. One month after treatment, the bilirubin level was decreased significantly when compared with preoperative one (P<0.01), while the blood indexes and immunological indicators showed no obvious changes (P>0.05) . After treatment, 2 patients (13.3％) developed cholangitis and 2 patients (13.3％) had small amount of biliary bleeding, which returned to normal after symptomatic treatment. No severe complications such as perforation of bile duct, massive bleeding, radiation enteritis and radioactive source leakage, etc., occurred. The patients were followed up for 55-402 days, 6 patients (40.0％) developed biliary re-obstruction. The median patency time of stent was 255 days, and 6-month stent patency rate was 64.5％. Five patients died and 10 patients survived, the 9-month survival rate was 64.3％, the median survival time was 368 days. Conclusion By using the new integrated portable biliary internal-external drainage catheter carrying125 I seeds, the effects of bile drainage and brachytherapy can be simultaneously achieved. Preliminary clinical practice indicates that this new drainage catheter is feasible, safe and effective, although its long-term efficacy needs to be clarified with further follow-up observations and controlled studies.

Objective:To study the effects of beta tricalcium phosphate(β-TCP)/collagen scaffold loaded with human bone morphogenetic protein 2 (hBMP2) plasmid on the osteogenesis ability of MC3T3-E1 cells.Methods:hBMP2 DNA plasmid-modified β-TCP/collagen scaffold and the naked plasmid(control) were constructed.MC3T3-E1 cells were respectively in vitro cultured onto the β-TCP/collagen scaffold with hBMP2(Z) and with control plasmid(Z0),on peace dish with the saffold and hBMP2(M) and with the control plasmid(M0).The surface morphology of the samples was observed by SEM.Osteogenesis of the cells was examined by alkaline phosphatase activity(ALP) test,real-time fluorescent quantitative PCR for the detection of Runx2,OCN,ALP and OPN mRNA expression.Data were statistically analyzed.Results:The composite sample surface of plasmid DNA containing hBMP2 modified β-TCP/collagen was porous;group Z and M showed highter ALP activity and higher mRNA expression of Runx2,OCN,ALP and OPN than group Z0 and M0;so did group Z than group M.Conclusion:Porous β-TCP/collagen scaffold loaded with BMP2 DNA is potential for osteoinduction.

OBJECTIVETo evaluate the application of low-dose CT enterography with adaptive iterative dose reduction(AIDR) technique in diagnosing Crohn's disease.

METHODSRetrospective analysis was performed on 26 patients diagnosed as Crohn's disease by the multidisciplinary team in our hospital. Low-dose CT enterography with 640-slice MDCT was performed on these 26 patients using adaptive iterative dose reduction(AIDR) technique. Characteristics of Crohn's disease in CT enterography images were independently analyzed by two radiologists who were experienced in Crohn's disease with calculating the total radiation dosage.

RESULTSThe radiation dosage of 26 patients ranged from 5.58 to 12.90 [mean (9.00±2.00)] mSv, which was lower than conventional scan (around 15 mSv) known from the literatures. According to the images of CT enterography of 26 cases, bowel wall thickening with abnormal enhancement and lymphadenectasis were found in 25 cases with total 109 segmental bowel wall thickening. Among 25 thickening cases, enterostenosis was found in 16 cases, stratification enhancement in 12 cases and comb sign in 14 cases. Besides, it was found that 8 cases with hyperdense fat on the mesenteric side, 7 cases with intestinal fistula, 6 cases with abdominal cavity abscess, and 3 cases with anal fistula.

CONCLUSIONCT enterography of Crohn's disease with adaptive iterative dose reduction technique is an effective method to evaluate Crohn's disease without compromising image quality with reduced radiation dosage.

Objective To explore the effect of cannabinoid receptor 2(CB2)on orthodontic tooth movement(OTM)rate and periodontal tissue reconstruction of pressure area in mice.Methods Thirty CB2-/-male mice and thirty littermate control WT male mice were individually accepted the orthodontic appliance at their age of 6 weeks.The mice were respectively scarified at 3 days,7 days,14 days and 21 days after the operation.Then the tooth movement distance was examined through the stereomicroscope.Hematoxylin-eosin staining was performed to explore the biological responses of periodontium at the distal mesial root pressure area.Anti-tartrate acid phospha-tase staining was performed to calculate the number and distribution of osteoclasts at the distal mesial root pressure area,and MMP-9 was evaluated by immunohistochemistry to examine the number of MMP-9(+)monocytes and multinucleated cells in the same district as the TRAP staining.Results Compared with those WT mice at 3,7,14 and 21 days,OTM distance showed a gradual increased tendency according with experimental time over 21 days.The widths of periodontal ligament on the pressure side were markedly greater in CB2-/-mice than WT mice at 7,14 and 21 days(P＜0.000 1).The numbers of TRAP positive osteoclasts were significantly greater in CB2-/-mice than those in WT mice at 14 days of OTM(P＜0.001).MMP-9 immunohistochemical staining showed that the number of MMP-9(+)monocytes and multinucleated cells was more in CB2-/-mice than that in WT mice at 14 days of OTM(P＜0.05).Conclusion The absence of CB2 accelerates orthodontic tooth movement under or-thodontic force.The absence of CB2 reinforces bone resorption in orthodontic tooth movement compressive area dur-ing orthodontic tooth movement.