BACKGROUND: Study on bone tissue-engineered material is one of the most successful fields in tissue engineering, but the mechanism on synthesis of artificial bone has not been known in many aspects.OBJECTIVE: To explore the mechanism of collagen and calcium phosphate (CP) in artificial bone synthesis.DESIGN: Single sample experiment was designed.SETTING: Material Research Room of Honghe University.MATERIALS: The experiment was performed in Material Research Room of Honghe University from July to August 2003. The materials included collagen (10 g/L acetic acid solution), calcium chloride, sodium dihydrogen phosphate (SDP), sodium hydroxide (NaOH), Tris, hydrochloric acid and deionized water (DI water).METHODS: Liquid nitrogen freezing and freeze-drying were used to prepare collagen-CP complexes A and B and the samples at different times during mineralization. UV spectrophotometer was used to determine the biomineralized dynamic curve of collagen-CP. Based on law of curve, the different times of sample collection were determined in preparation of electronic microscopic samples. According to electronic microscopic pictures and spectral data, mechanism analysis was carried on.MAIN OUTCOME MEASURES: Morphology of collagen-CP complex and law of its structure with time changeRESULTS: ①Under agitation, collagen-CP complex A was sheaf-like or needle-like in structure manufactured with retarded neutralization. ②Under static state, with biomineralization, collagen-CP complex B was in layered structure at initial phase of mineralization, which was similar to the self-assembled structure of pure collagen and the molarratio of C, O, P and Ca was 7.26: 20: 0: 2. At the end of mineralization, the structure was strip-like in high density with a certain grains and very fine rills and the molar ratio of C, O, P and Ca was 11.02: 22.5:1.06: 2.CONCLUSION: At the early phase of biomineralization, collagen iscoordinated initially with calcium ion, calcium-carrier layered collagen template is formed with the self-assembling of collagen, and then phosphates is combined with calcium ion to manufacture calcium phosphate in the formed template. By controlling agitation and acting time, collagen complex material of reticular and spinal structure is obtained.

Objective Toinvestigatethemolecularmechanismsofmitochondrialpathway-mediated apoptosisinintracranialaneurysminitiationinrabbits.Methods FifteenNewZealandwhiterabbitswere divided into 3 groups using the computer random method. After using bilateral carotid artery ligation for modeling basilar artery aneurysm,they were divided into a 2-day group (n=3),a 7-day group (n=6)(3 of them were used for real-time quantitative polymerase chain reaction [PCR]analysis),and a sham operation group (n=6)(3 of them were used for real-time quantitative PCR analysis). The tissue of apex of basilar artery was harvested and the histopathological changes in the vascular wall were observed. TUNEL staining was used to detect apoptotic cells and immunohistochemical staining,and quantitative analysis was used to analyze inflammatory cell distribution. Real-time quantitative PCR was used to detect the expression of apoptosis-related protein mRNA. Results (1 )After modeling,the apoptotic cells were found at the apex of basilar artery in rabbits (the site of internal elastic layer lesion )of the 2-day group and 7-day group. In the 2-day group after operation,the numbers of apoptotic cells (4. 02 ± 0. 21)were significantly higher than those of the basilar artery trunk (0. 40 ± 0. 13),the left posterior cerebral artery (0. 41 ± 0.22),and the right posterior cerebral artery (0. 29 ± 0. 11). The differences were statistically significant (P<0. 05). After modeling,the numbers of apoptotic cells (5. 01 ± 0. 29)of the 7-day group were significantly higher than those of the basilar artery trunk (0. 49 ± 0. 21),the left posterior cerebral artery (0. 31 ± 0. 12),and the right posterior cerebral artery (0. 41 ± 0. 19)(P<0. 05). The internal elastic layer lesions and apoptotic cells were not observed in the rabbits of the sham operation group. (2)After modeling, the expression levels of caspase 9 (1. 97 ± 0. 23)and caspase-3 mRNA (2. 31 ± 0. 40)at the apex of basilar artery in rabbits of the 7-day group were increased significantly compared with that of the sham group (P<0.01).Conclusion Apoptosisisinvolvedintheearlyprocessofaneurysmsinsimple hemodynamics-induced basilar terminus aneurysm formation. Its molecular mechanisms are activated by Bcl-2-mediated mitochondrial pathway through caspase-9.

Objective To discuss the treatment method and opportunity for patients with gallbladder stones and extrahepatic bile duct stones who failed endoscopic removal of common bile duct stones by endoscopic retrograde cholangiopancreaticography (ERCP). Methods 12 patients, with gallbladder stones and extrahepatic bile duct stones, failed endoscopic stone extraction (ESE), underwent emergency one-stage laparoscopic cholecystectomy (LC) and Laparoscopic common bile duct exploration (LCBDE). Results All of the patients were successfully completed LC +LCBDE and stones were completely removed. Hyperamylasemia occurred in 3 cases and there was no bile leakage, intestinal leakage, cholangitis, pancreatitis, biliary bleeding and other complications. Conclusions Emergency LCBDE has been shown to be a safe and effective salvage procedure for failed ESE.

ObjectiveTo investigate correlation between drug-resistance related genes and mobile genetic elements of Klebsiella pneumoniae resistant to β-lactams. Methods Forty-seven strains of multidrug-resistant Klebsiella pneumoniae were collected from 6 hospitals in Hangzhou and Huzhou of Zhejiang province from August 2008 to May 2010.Modified Hodge test was performed to detect phenotypes of carbapenemases.Forty kinds of β-lactamases (class A-D),ompK35,ompK36,and 12 kinds of mobile genetic elements were detected by PCR,and the results were analyzed by index cluster.ResultsThirty-five strains were positive in modified Hodge test,and 5 kinds of β-lactamases gene ( including KPC-2-like,GenBank:HQ258934) and 9 kinds of mobile genetic elements were detected.Mutations were observed in ompK35 and ompK36 when compared with sensitive strains.Index cluster analysis showed that correlation existed between KPC-2,KPC-2-like and ISKpn6,between TEM-1 and ISEcpl,IS26,int Ⅰ 1,trbC,IS903,and between CMY-2,OXA-30,DHA-1 and tnpU,tnp513,trbC.ConclusionsFive kinds of β-1actamases genes,and mutations in ompK35 and ompK36 may be associated with the resistance to β-1actams in multidrug-resistant Klebsiella pneumoniae.