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Purpose: Using β-TCP as the control, two kinds of bioceramics were prepared to determine whether and studied bioceramics could promote new bone formation in vitro, which will lay a foundation to further study the mechanism of new bone formation., Methods: Osteoblast-like cells from calvaria of neonatal Sprague Dawley rats (24h old) were purified and then used in this study. MTT assay demonstrated that the extracts of three kinds of materials could promote cell proliferation. Cell periods were determined by FCM. Alkaline phosphatase(ALP) activity was detected to illustrate the contents of ALP in the supernatant. SEM was used to observe cell attachment on the disc. SPSS 17.0 software package was used for data analysis., Results: According to MTT assay, the amounts of cell-treated extracts were increased with the growth of CS contents. The result of cell periods showed that the DNA in the period of G0/G1 of cell-treated containing CS extracts were much higher than those of β-TCP. And at the same point, the amounts of ALP raised with the increase of CS contents in a time-dependent way. SEM results found that cell attachment on the surface of discs of containing CS was better than that of pure β-TCP.There was no significant difference between 50wt% CS and 100wt% CS., Conclusions: The abilities of cell proliferation and differentiation were increased with the growth of CS contents. The biological qualities of containing CS materials were better than those of β-TCP.

Objective: To investigate nerve growth factor (beta-NGF) and its receptors expression in human pancreatic ductal adenocarcinoma., Methods: Expression and distribution of beta-NGF, tyrosine kinase A (TrKA) and P75(NGFR) were detected in operation tissue specimens of pancreatic ductal adenocarcinoma with immunohistochemistry and real-time PCR. Relations of beta-NGF and its receptors with clinical pathological characters, especially nerve invasion were analyzed., Results: beta-NGF and TrKA expression are higher in pancreatic adenocarcinoma than normal pancreas, and the differences are significant (P < 0.01). beta-NGF and TrKA expression are associated with the differentiation grades (DG), lymphatic node metastasis, nerve invasion and surgical pathological stages. Poorer of DG and later stages, more expression of beta-NGF and TrKA. beta-NGF and TrKA expression have positive correlations. beta-NGF, TrKA and P75(NGFR) mRNA expression have significantly increased 3.84, 4.23 and 2.41 times than normal tissues by real-time PCR, respectively., Conclusions: beta-NGF and TrKA might play potential roles in carcinogenesis for pancreatic cancer, have affinity with clinicopathological characters of pancreatic cancer. beta-NGF and TrKA may have mutual effect in signal transduction leading to perineural invasion of pancreatic carcinoma.

Objective: To investigate the effects of estrogen-deficiency upon the expression of osteoprotegerin (OPG) in alveolar bone so as to clarify the role of estrogen in alveolar bone metabolism., Methods: Fifty-three SD rats were randomly divided into 3 groups: OVX group (n=18) undergoing bilateral ovariectomy, OVX + E2 group (n=18), undergoing bilateral ovariectomy and subcutaneous injection of estradiol once 3 days since day 2 after the operation, and sham operation group (n=17) undergoing sham operation. Four weeks after the operation periodontal ligature was conducted and high-sugar diet was fed to establish periodontitis models. Four weeks later the rats were killed. The morphological changes and expression of OPG in alveolar bone were observed by light microscopy and immunohistochemistry., Results: All the rats showed sparseness of bone trabeculae in alveolar bone and osteoclasts and lacuna at the surface of alveolar bone, especially the rate of the group OVX. The A values (absorption of the OPG expression) in the alveolar bone of the OVX groups was 27 854 +/- 5246, significantly lower than those of the sham operation group and OVX + E2 group (38 799 +/- 6228 and 37 146 +/- 6394 respectively, both P < 0.05) without significant difference between the sham operation group and OVX + E2 group (P > 0.05)., Conclusion: Estrogen deficiency decreases the expression of OPG in alveolar bone, and enhances the absorption of alveolar bone.

Activin, which is included in the transforming growth factor-beta (TGF beta) superfamily of proteins and receptors, is known to have broad-ranging effects in the creatures. The mature peptide of beta A subunit of this gene, one of the most highly conserved sequence, can elevate the basal secretion of follicle-stimulating hormone (FSH) in the pituitary and FSH is pivotal to organism's reproduction. Reproduction block is one of the main reasons which cause giant panda to extinct. The sequence of Activin beta A subunit gene mature peptides has been successfully amplified from giant panda, red panda and malayan sun bear's genomic DNA by using polymerase chain reaction (PCR) with a pair of degenerate primers. The PCR products were cloned into the vector pBlueScript+ of Esherichia coli. Sequence analysis of Activin beta A subunit gene mature peptides shows that the length of this gene segment is the same (359 bp) and there is no intron in all three species. The sequence encodes a peptide of 119 amino acid residues. The homology comparison demonstrates 93.9% DNA homology and 99% homology in amino acid among these three species. Both GenBank blast search result and restriction enzyme map reveal that the sequences of Activin beta A subunit gene mature peptides of different species are highly conserved during the evolution process. Phylogeny analysis is performed with PHYLIP software package. A consistent phylogeny tree has been drawn with three different methods. The software analysis outcome accords with the academic view that giant panda has a closer relationship to the malayan sun bear than the red panda. Giant panda should be grouped into the bear family (Uersidae) with the malayan sun bear. As to the red panda, it would be better that this animal be grouped into the unique family (red panda family) because of great difference between the red panda and the bears (Uersidae).

An unique culture system has been established which can effectively indicate fragile sites induced by BrdU on giant panda chromosomes. After we cultured the lymphocytes of giant panda for 96 hours and treated it with low concentration of BrdU (10 micrograms/ml) for only a short time (4 hours), the areas of high-frequency-expressed fragile sites were successfully located on the centromeres of No. 2 and No. 12 chromosomes. After statistic analysis, we found that the frequency of fragile sites on No. 2 and No. 12 chromosomes are notably different among pandas. What is more important, the former is relative to giant pandas' breeding conditions and correlation coefficiency (r equals to -0.772). The result indicates that high frequency of fragile sites on No. 2 chromosome is unfavorable to giant panda's breeding and survival of filial generation.

Using the cultured giant panda (Ailuropoda melanoleuca) lymphocytes as experimental material, we carried out the terminal marking on the chromosomes which were in replication by adding BrdU (a final concentration: 10 micrograms/ml) about four hours before harvesting the cells. The chromosomes marked by BrdU were proceeded by staining with acridine orange solution (0.05%), irradiated by ultraviolet and counter-stained by Giemsa, we obtained clear chromosomes replication patterns. According to the different replication bands, every chromosome's characteristics in late replication behavior could be identified. In the two X chromosomes of female individual, one X chromosome is obviously much later than the other one. Especially in the large area near centromere on the long arm of late replicating X chromosome. In the male individual, there is also a large area on the long arm of chromosome Y which replicates very late, but the end of long arm of chromosome Y replicates much earlier.