BACKGROUND:Although the preparation of bone tissue engineering scaffolds can achieve satisfactory results by solvent casting/particulate leaching, in situ molding method, electrospinning, phase seperation/freeze drying, gas foaming, there are stil some deficiencies in the accuracy, pore uniformity, spatial structure complexity, personalized stents. ＜br> OBJECTIVE:To prepareβ-tricalcium phosphate bone tissue engineering scaffolds using 3D printing. ＜br> METHODS:Drug-loadedβ-tricalcium phosphate scaffolds were prepared with 3D printing, and the structure was observed to measure its porosity and mechanical strength. The scaffold was immersed in simulated body fluid for 15 weeks to observe the quality change. The scaffold was co-cultured with rat bone marrow mesenchymal stem cells for 7 days to observe celladhesion and morphological changes. Rat bone marrow mesenchymal stem cells were cultured in extracts of drug-loadedβ-tricalcium phosphate scaffold and low-glucose Dulbecco's modified Eagle’s medium containing 15%fetal bovine serum for 24, 48, and 72 hours, to determine the absorbance values and cytotoxicity grading, respectively. Meanwhile, the cells were subjected to osteogenic culture for 1 week, and ＜br> the alkaline phosphatase activities in two groups were detected. ＜br> RESULTS AND CONCLUSION:The prepared scaffold showed irregular micropores, high porosity, uniform pore distribution, high pore connectivity rate, and large compressive strength. The drug-loadedβ-tricalcium phosphate scaffold degraded completely with 15 weeks, and cancellous bone defect repair was completed in the same period. Rat bone marrow mesenchymal stem cells adhered to the surface of drug-loadedβ-tricalcium phosphate scaffold and went deep into the scaffold, showing good growth and proliferation. The activity of alkaline phosphatase was also improved. These findings indicate that the drug-loadedβ-tricalcium phosphate scaffold has good biocompatibility.

The G395R mutation of human sodium/iodide symporter gene was investigated by PCR-RFLP in 52 children with congenital hypothyroidism and 106 health children. The result suggested that G395R mutation may not be the main cause of congenital hypothyroidism in Qingdao.

Aim To investigate the effects of PB-19 on action potential (AP) of ventricular cells in vitro and ischemia and reperfusion induced arrhythmias in vivo in rats. Methods ① We established the model of isolated rat right ventricular wall and perfused the models with normal Tyrode’s solution and PB-19.Microelectrode was inserted into the cells to record the AP. ② We ligated the left anterior descending coronary artery of rats to study the effects of PB-19 on ischemia and reperfusion induced arrhythmias. 50 rats were divided into 5 groups randomly and were given iv. injection with normal saline and PB-19 of different concentrations respectively. We recorded Ⅱ ECG of the rats. Results ①In vitro models, the APD_ 50、APD_ 90 of PB-19 group were significantly longer than that of control group respectively (P

Case-Control Studies ; Child, Preschool ; Congenital Hypothyroidism ; DNA ; genetics ; Female ; Humans ; Hypothyroidism ; genetics ; Infant ; Iodine ; metabolism ; Male ; Mutation ; Polymerase Chain Reaction ; Sodium ; metabolism ; Symporters ; genetics

Objective To investigate the clinical characteristics, location, treatment and prognosis of periosteal osteosarcoma. Methods The data of 1 patient with periosteal osteosarcoma was retrospectively analyzed, and the 35 cases reported in CNKI database in recent years were analyzed. Results The patient of periosteal osteosarcoma was female and 16 years old. Periosteal osteosarcoma occurred in the tibia. The patient was treated with extensional resection, and had no recurrence and metastasis 3 months after operation. Among the 35 patients reported in the literature, the age of onset ranged from 14 to 35, the female was slightly more than the male (19 cases vs. 16 cases), and the lesion site was mainly in the tibia and femur. The 35 patients underwent surgical treatment, and 4 cases had metastasis;6 cases were treated by surgery combined with chemotherapy. Conclusions Female patients with periosteal osteosarcoma were slightly more than male, and the lesion site is mainly in the tibia and femur. The chemotherapy effect is not exact, and extensional resection is the most effective treatment method. The transfer site and the characteristics are not exact.

OBJECTIVE: To review the characteristics changes of calcium phosphate cement (CPC) as drug delayed release carrier before and after carrying different drugs, analyze dynamic principle and influential factors of drug delayed release system, and summarize new advances of CPC in animal experiments and clinical studies.DATA SOURCES: A computer-based online search of CNKI (www.cnki.net/index.htm) and PubMed (http://www.ncbi.nlm.nih.gov/PubMed) was performed for articles published between 1985 and 2009 with the key words of "calcium phosphate cement, CPC, drug delivery system, release" in Chinese and English.DATA SELECTION: Articles highly related with CPC; articles concerning CPC as drug delivery system. Repetitive articles were excluded.MAIN OUTCOME MEASURES: Changes in physico-chemical properties and drug release dynamics of CPC as delivery carrier of different drugs.RESULTS: CPC is an outstanding skeletal defect restorative material. Considering physico-chemical properties, drug release dynamics and histocompatibility, CPC is good delayed release carrier of drugs. However, its clinical application is limited only in bone defect repair of unloading sites due to its bad compressive strength and adhesivity. Therefore, studies on these aspects require exploration.CONCLUSION: CPC as a drug delivery system is a novel administration method. It can repair bone defect and release drug to achieve favorable treatment effects. CPC has been extensively used in osteomyelitis, bone tuberculosis, bone tumor, bone fracture, bone nonunion, and artificial joint replacement.

Based on avian leukosis virus ( ALV) p19 gene terminal nucleotide sequence, a 82 bp double-stranded DNA fragment was chemically synthesized and cloned into the expression vector pGEMEX-1. The sequencing result indicated th at the cloned fragment was a correct version of the one designed both in nucleot ide sequence and in its open reading frame. The recombinant was used to transfor m E.coli BL21 (DE3). The cloned fragment was expressed as a fused protein wi th T7 gene 10 leader peptide and was shown to be 34 kD in size on SDS-PAGE gel when induced with 1 mmol/L IPTG. The expression product was able to bind immunol ogically to rabbit anti-ALV serum in Western-blot assay and is being tested to differentiate exogenous from endogenous ALV.

Objective To improve the method of blood collection from external jugular vein in rats,so as to repeatedly obtain blood samples of high quality and to meet the special requirements of the experiment.Methods The experimental rats were anesthetized by intraperitoneal anesthesia,and the jugular vein was fully exposed with special fixed method.Whereafter,the blood samples were collected by disposable vacuum blood vessels.Results This method had little traumatic effect.The blood samples were collected from 60 rats at an interval of 14 days with 1.8 to 2.5 mL each time.The success rate was above 95％,and the normal activities of the rats were not apparently affected.This vacuum blood collection method guaranteed the quality of serum,and the veracity of blood detection and analysis were also significantly improved.Conclusion On the basis of the principle of animal welfare,the improved rat jugular vein blood collection method has the advantages of simple operation,less trauma,large blood collection,high blood sample quality aod so on,which can ensure the effect of the special experiment.

BACKGROUND: Aseptic loosening occurs after long-term total hip replacement, which directly affects the service life and prospective efficacy of artificial joints. The particles produced by artificial joint wear lead to the surrounding bone dissolved, further cause loosening, among which, polyethylene particles because of acetabular liner wear stand out. OBJECTIVE: To systematically assess the acetabular liner wear, loosening and osteolysis caused by cross-linked polyethylene or conventional polyethylene after total hip arthroplasty. METHODS: A computer-based research of Medline, EMbase, CBM, CNKI, CqVip, WanFang databases before December 2015 and Cochrane (3rd issue, 2011) was performed in accordance with the retrieval strategy made by Cochrane collaboration. A manual retrieval of related bone journals and conference papers was conducted. Eleven randomized controlled trials about the wear caused by cross-linked polyethylene or conventional polyethylene after total hip arthroplasty were enrolled based on inclusion criteria, followed by a Meta-analysis using RevMan 5.0 software. RESULTS AND CONCLUSION: (1) Eleven randomized controlled trials involving 952 patients were included. (2) Meta-analysis showed that the acetabular liner wear rate of cross-linked polyethylene was significantly lower than that of conventional polyethylene at 5 years postoperatively [MD=-0.07, CI(-0.09, -0.05), I2=93%, P < 0.00001]; the large heterogeneity was decreased [MD=-0.06, 95%CI (-0.07, -0.04), I2=39%, P < 0.00001] after three research removed through sensitivity analysis. (3) The osteolysis rate in the cross-linked polyethylene group was significantly lower than that in the conventional polyethylene group [RR=0.39, 95%CI (0.27, 0.57), I2=0%, P < 0.00001]. (4) These results suggest that the cross-linked polyethylene liners exhibit reduced radiological wear and osteolysis, but the mean follow-up of 5 years (1.8 to 8.0) cannot meet the long-term requirements. Therefore, multi-central, large sample size and high-quality randomized controlled trials are needed to testify the efficacy and safety of cross-linked polyethylene.BACKGROUND: Aseptic loosening occurs after long-term total hip replacement, which directly affects the service life and prospective efficacy of artificial joints. The particles produced by artificial joint wear lead to the surrounding bone dissolved, further cause loosening, among which, polyethylene particles because of acetabular liner wear stand out. OBJECTIVE: To systematically assess the acetabular liner wear, loosening and osteolysis caused by cross-linked polyethylene or conventional polyethylene after total hip arthroplasty. METHODS: A computer-based research of Medline, EMbase, CBM, CNKI, CqVip, WanFang databases before December 2015 and Cochrane (3rd issue, 2011) was performed in accordance with the retrieval strategy made by Cochrane collaboration. A manual retrieval of related bone journals and conference papers was conducted. Eleven randomized controlled trials about the wear caused by cross-linked polyethylene or conventional polyethylene after total hip arthroplasty were enrolled based on inclusion criteria, followed by a Meta-analysis using RevMan 5.0 software. RESULTS AND CONCLUSION: (1) Eleven randomized controlled trials involving 952 patients were included. (2) Meta-analysis showed that the acetabular liner wear rate of cross-linked polyethylene was significantly lower than that of conventional polyethylene at 5 years postoperatively [MD=-0.07, CI(-0.09, -0.05), I2=93%, P < 0.00001]; the large heterogeneity was decreased [MD=-0.06, 95%CI (-0.07, -0.04), I2=39%, P < 0.00001] after three research removed through sensitivity analysis. (3) The osteolysis rate in the cross-linked polyethylene group was significantly lower than that in the conventional polyethylene group [RR=0.39, 95%CI (0.27, 0.57), I2=0%, P < 0.00001]. (4) These results suggest that the cross-linked polyethylene liners exhibit reduced radiological wear and osteolysis, but the mean follow-up of 5 years (1.8 to 8.0) cannot meet the long-term requirements. Therefore, multi-central, large sample size and high-quality randomized controlled trials are needed to testify the efficacy and safety of cross-linked polyethylene.

OBJECTIVE: To investigate the occurring mechanism and clinical characteristics of severe acute pancreatitis (SAP) associated with hypoalbuminemia in early stage and its influence on prognosis of SAP and the preventive and therapeutic management of this disease. METHODS: One hundred and thirty-eight cases diagnosed as SAP complicated by hypoalbuminemia in early stage were accepted in our hospital from August 1, 2003 to December 31, 2004, and they were divided into 2 groups according to the level of plasma albumin: mild hypoalbuminemia (30 to 35 g/L) group and severe hypoalbuminemia (<30 g/L) group. The complications in the early stage, related parameters, and the incidence rate of infection and mortality in the later stage were evaluated respectively. RESULTS: The incidence rates of renal dysfunction, shock, cardiovascular failure and gastrointestinal hemorrhage, the score of acute physiology and chronic health evaluation II (APACHE II ) and the frequencies of pulse and breath in the severe hypoalbuminemia group were all higher than those in the mild hypoalbuminemia group (P<0.05 or P<0.01). The differences of incidence rate of hepatic failure and the scores of Ranson and Balthazar CT between these two groups had no statistical significance (P>0.05). The incidence rate of infection and the mortality in the severe hypoalbuminemia group were higher than those in the mild hypoalbuminemia group (P<0.01) in the later stage of SAP. CONCLUSION: Hypoalbuminemia in the early stage can accelerate the deterioration in pathophysiology of SAP. The lower level of the plasma albumin is in the early stage, the more complications and the higher incidence rate of infection and mortality will be in the later stage. To relieve the extent of systemic inflammatory response syndrome (SIRS) and abundant supplement of albumin, amino acid and lipid in time may be crucial to prevent the occurrence and deterioration of hypoalbuminemia.