To investigate the osteogenesis of calcium phosphate ceramics, β-TCP ceramics were implanted into the condyle femur of rabbits, and tetracycline was injected termly. Specimens were host at 1, 2, 3, 4, 5, 6 months aft...To investigate the osteogenesis of calcium phosphate ceramics, β-TCP ceramics were implanted into the condyle femur of rabbits, and tetracycline was injected termly. Specimens were host at 1, 2, 3, 4, 5, 6 months after implanted. The new bone formation and osteogenesis process were observed by the histomorphology, fluorescent microscope, SEM and EPMA. The results demonstrate that, osteogenesis is active, there are abundant osteoblasts on the surface of osteoid, mesenchymal cell hyperplasia and incursion is found in materials after 1 month. After 2 months, there is blood vessel formation and macrophage soakage within materials. Bone-island appears and connects by bone-bridge after 3 months. β-TCP ceramics degrade and are dispersed by new formation bone. Woven bone turns into bone lamella by rebuilding and calcification. The materials entirely change their original shape and combines with bone tissue as a whole after 6 months. The typical structure of spongy bone forms. It is confirmed that β-TCP is a degradable biocompatible artificial bone material which can incorporating in life.展开更多
The cDNA encoding the luciferase from lantern mRNA of one diurnal firefly Pyrocoelia pygidialis Pic, 1926 has been cloned, sequenced and functionally expressed. The cDNA sequence of P pygidialis luciferase is 1647 bas...The cDNA encoding the luciferase from lantern mRNA of one diurnal firefly Pyrocoelia pygidialis Pic, 1926 has been cloned, sequenced and functionally expressed. The cDNA sequence of P pygidialis luciferase is 1647 base pairs in length, coding a protein of 548 amino acid residues. Sequence analysis of the deduced amino acid sequence showed that this luciferase had 97.8% resemblance to luciferases from the fireflies Lampyris noctiluca, Lampyris turkestanicus and Nyctophila cf. caucasica. Phylogenetic analysis using deduced amino acid sequence showed that P pygidialis located at the base of Lampyris＋Nyctophila clade with robust support （BP=97%）; but did not show a monophyletic relationship with its congeneric species P pectoralis, P tufa and P miyako, all three are strong luminous and nocturnal species. The expression worked in recombinant Escherichia coli. Expression product had a 70kDa band and emitted yellow-green luminescence in the presence of luciferin. Five loops in the P pygidialis luciferase, L1 （NI98-G208）, L2 （T240-G247）, L3 （G317-K322）, L4 （L343-I350） and L5 （G522-D532）, were found from the structure modeling analysis in the cleft, where it was considered the active site for the substrate compound entering and binding. Different amino acid residues between the luciferases of P. pygidialis and the three other known strong luminous species can not explain the situation of weak or strong luminescence. Future study of these loops, residues or crystal structure analysis may be helpful in understanding the real differences between the luciferases between diurnal and nocturnal species.展开更多
文摘To investigate the osteogenesis of calcium phosphate ceramics, β-TCP ceramics were implanted into the condyle femur of rabbits, and tetracycline was injected termly. Specimens were host at 1, 2, 3, 4, 5, 6 months after implanted. The new bone formation and osteogenesis process were observed by the histomorphology, fluorescent microscope, SEM and EPMA. The results demonstrate that, osteogenesis is active, there are abundant osteoblasts on the surface of osteoid, mesenchymal cell hyperplasia and incursion is found in materials after 1 month. After 2 months, there is blood vessel formation and macrophage soakage within materials. Bone-island appears and connects by bone-bridge after 3 months. β-TCP ceramics degrade and are dispersed by new formation bone. Woven bone turns into bone lamella by rebuilding and calcification. The materials entirely change their original shape and combines with bone tissue as a whole after 6 months. The typical structure of spongy bone forms. It is confirmed that β-TCP is a degradable biocompatible artificial bone material which can incorporating in life.
基金the Natural Foundation of Sciences of Yunnan Province (2006C0046Q)Partly by the Chinese Academy of Sciences (O706551141)
文摘The cDNA encoding the luciferase from lantern mRNA of one diurnal firefly Pyrocoelia pygidialis Pic, 1926 has been cloned, sequenced and functionally expressed. The cDNA sequence of P pygidialis luciferase is 1647 base pairs in length, coding a protein of 548 amino acid residues. Sequence analysis of the deduced amino acid sequence showed that this luciferase had 97.8% resemblance to luciferases from the fireflies Lampyris noctiluca, Lampyris turkestanicus and Nyctophila cf. caucasica. Phylogenetic analysis using deduced amino acid sequence showed that P pygidialis located at the base of Lampyris＋Nyctophila clade with robust support （BP=97%）; but did not show a monophyletic relationship with its congeneric species P pectoralis, P tufa and P miyako, all three are strong luminous and nocturnal species. The expression worked in recombinant Escherichia coli. Expression product had a 70kDa band and emitted yellow-green luminescence in the presence of luciferin. Five loops in the P pygidialis luciferase, L1 （NI98-G208）, L2 （T240-G247）, L3 （G317-K322）, L4 （L343-I350） and L5 （G522-D532）, were found from the structure modeling analysis in the cleft, where it was considered the active site for the substrate compound entering and binding. Different amino acid residues between the luciferases of P. pygidialis and the three other known strong luminous species can not explain the situation of weak or strong luminescence. Future study of these loops, residues or crystal structure analysis may be helpful in understanding the real differences between the luciferases between diurnal and nocturnal species.
