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In this study, optical coherence tomography (OCT) with an axial resolution of 15 mum was used to investigate the depth and degeneration dependences of the refractive index (RI) of articular cartilage collected from bovine patellae in vitro. Eighteen disks of articular cartilage with a diameter of 6.35 mm harvested from different patellae were successfully prepared. Each disk was cut into two halves and three horizontal cartilage slices (n = 18 x 2 x 3) with an approximately equal thickness of 0.5 mm were further prepared from each half disk. The cartilage slices were digested by two different enzymes, collagenase and trypsin, to disturb collagen fibrils and proteoglycans, respectively. The samples were submerged in the physiological saline and tested using OCT before and after the enzyme digestion and the RI for each specimen was calculated. The RI of articular cartilage from the superficial to deep regions was 1.361 +/- 0.032 (mean +/- SD), 1.338 +/- 0.036, and 1.371 +/- 0.041 for normal specimens; 1.357 +/- 0.036, 1.331 +/- 0.030, and 1.392 +/- 0.037 for trypsin digested specimens; and 1.361 +/- 0.032, 1.336 +/- 0.048, and 1.376 +/- 0.043 for those treated by collagenase, respectively. Two-factor repeated measure ANOVA revealed that for all the three groups of specimens, the RI in different depths was significantly different (p0.05). However, we found that the trypsin and collagenase treatments did not exert a significant effect on the RI (p0.05). The results suggested that the depth dependence of articular cartilage should be taken into account when OCT is used for related measurement.

The purpose of this study was to investigate the effect of vitamin B12 on palatal development by co-administration of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and dexamethasone (DEX). We examined the morphological and histological features of the palatal shelf and expression levels of key signaling molecules (transforming growth factor-β3 (TGF-β3) and TGF-β type I receptor (activin receptor-like kinase 5, ALK5)) during palatogenesis among a control group (Group A), TCDD+DEX exposed group (Group B), and TCDD+DEX+vitamin B12 exposed group (Group C). While we failed to find that vitamin B12 decreased the incidence of cleft palate induced by TCDD+DEX treatment, the expression levels of key signaling molecules (TGF-β3 and ALK5) during palatogenesis were significantly modulated. In TCDD+DEX exposed and TCDD+DEX+vitamin B12 exposed groups, palatal shelves could not contact in the midline due to their small sizes. Our results suggest that vitamin B12 may inhibit the expression of some cleft palate inducers such as TGF-β3 and ALK5 in DEX+TCDD exposed mice, which may be beneficial against palatogenesis to some degree, even though we were unable to observe a protective role of vitamin B12 in morphological and histological alterations of palatal shelves induced by DEX and TCDD.

To establish a good animal model of cleft palate and confirm whether 2, 3, 7, 8-tetrachloro-p-dibenzodioxin (TCDD) and Dexamethasone (DEX) induced palatal cleft in mice is related to the fold change of transforming growth factor-beta 3 (TGF-beta3) and activin receptor-like kinase 5 (Alk5).Pregnant mice were treated with oral medication of TCDD and intraperitoneal injection with DEX on GD10-12 in experimental group while the control group without any treatment. Then embryos were examined on GD17.5 under stereomicroscope for calculating the incidence of cleft palate and palatal shelves were dissected from the staged embryos respectively for RNA extraction on GD13.5, GD14.5 and GD15.5. At last the real-time PCR and SYBR Green I detection were used for RNA relative quantification.Cleft palate could be induced 100% in C57BL/6J fetal mice with TCDD and DEX, thus established a stable animal model for further molecular studies of cleft palate. There were no significant difference in expression level of TGF-beta3 and Alk5 on GD13.5 among the groups, but the differences were statistically significant on GD14.5 and GD15.5 (P0.05). On the contrary, the expression level of Alk5 were significantly higher in experimental group (P0.05).Combined effects of TCDD and DEX could induce a stable formation of cleft palate and down-regulated mRNA of TGF-beta3 and up-regulated Alk5 may contribute to the occurrence of cleft palate.

To identify the expression of antagonist beta-TrCP protein in Sonic hedgehog signal transduction pathway and Wnt signal transduction pathway in hair follicle tissues.The heads of day 18 embryo, and one day and six-days-old postnatal mice were acquired and treated with 40 g/L paraformaldehyde fixation for 48 h and paraffin embedding. The expression of beta-TrCP proteins was examined using LsAB (labelled streptavidin-biotin) method.beta-TrCP proteins were expressed in the cytoplasm of the hair stems of hair follicle, hair cuticle, cuticle of root sheath, Huxley's layer of internal root sheath cells, external root sheath and mesenchymal tissues, but not in connective tissue sheath and Henle's layer of internal root sheath.TrCP express in the developmental hair follicle tissues, which implicates that beta-TrCP regulate the developmental hair follicle by mediating the signal transduction pathways.

To construct recombinant adenovirus carrying the mouse dentin caveolin-1 gene using the recombinant adenoviral vector system AdEasy.The cDNA fragment of caveolin-1 was derived from pTRE2-caveolin-1 by restriction enzyme digestion and subcloned into shuttle plasmid pAdtrack-CMV. The resulting plasmid pAdtrack-CMV-caveolin-1, after linearized by digesting with restriction endonuclease Pme I, was transformed into E. coli 1 BJ5183 which had been transformed by adenoviral backbone plasmid pAdEasy-1. The recombinant plasmid pAd-caveolin-1 was screened by kanamycin LB plate and then identified by restriction enzyme digestion. The linearized adenovirus plasmid pAd-caveolin-1 was packaged in 293 cells, then the recombinant adenovirus Ad-caveolin-1 was harvested. The expression of green fluorescence protein was observed under fluorescent microscope. With further amplification and purification, the titer of recombinant adenovirus was determined.The recombinant adenovirus was identified by restriction enzyme digestion analysis and gene sequencing. Cytopathic effect and the expression of GFP were observed in the infected 293 cells. The sequence of caveolin-1 gene insert was the same as that published in the GenBank. The titer of the recombinant adenovirus was 2 x 10(9) pfu/mL.The mouse caveolin-1 recombinant adenovirus was constructed successfully by using AdEasy adenovirus system. Cell transfection and expression of exogenous gene can be detected directly by observing the expression of GFP. These results provide the basis for the further study on the role of caveolin-1 gene in other scopes.

The depth of light penetration into highly scattering tissues can be improved by the application of biocompatible and osmotically active chemical agents. We compare the dynamics of optical clearing of tissue by the topical application of glycerol and dimethyl sulfoxide (DMSO) using optical coherence tomography (OCT). It is demonstrated experimentally that both agents can largely improve the OCT imaging depth for porcine stomach tissue. During a period of approximately 20 to 30 min after the application of glycerol image contrast is also enhanced. This enhancement disappears over time. Such enhancement of image contrast is not observed with DMSO. Glycerol causes a higher degree of dehydration of the tissue than DMSO does. We suggest that these phenomena are caused by a two-stage diffusion of the chemicals. The first stage of diffusion is from the top tissue to the intercellular space, and the second is into the cell matrix. During the first stage, the imaging contrast could be improved by dehydration.