Semaphorin 3A promotes osteogenic differentiation in human alveolar bone marrow mesenchymal stem cells.

The aim of the present study was to investigate the role of Semaphorin 3A (Sema3A) in the osteogenic differentiation of human alveolar bone marrow mesenchymal stem cells (hABMMSCs). To investigate whether Sema3A affects hABMMSC proliferation and osteogenic differentiation, a stable Sema3A-overexpression cell line was generated by infection with the pAdCMV-SEMA3A-MCS-EGFP vector. Cell counting kit-8 and clone formation assays were performed to determine the proliferation ability of hABMMSCs, while cell osteogenic differentiation was assayed using Alizarin Red S staining. In addition, reverse transcription-quantitative polymerase chain reaction was employed to detect the mRNA expression level of osteogenesis-associated genes, Runt-related transcription factor 2 (Runx2), osteopontin (Opn) and osteocalcin (Ocn), during the osteogenic differentiation. The results revealed that, compared with the normal control group, the cell morphology of the infected cells was stable and no significant alterations were observed. Overexpression of Sema3A in hABMMSCs significantly increased the cell proliferation ability compared with the control group. Furthermore, the Alizarin Red S staining assay results indicated that the ossification process of hABMMSCs overexpressing Sema3A was evidently faster in comparison with that of the control group cells. Overexpression of Sema3A by pAdCMV-SEMA3A-MCS-EGFP infection also significantly increased the mRNA expression levels of the osteogenic marker genes Runx2, Opn and Ocn. In conclusion, Sema3A was observed to be a key positive regulator in hABMMSC osteogenic differentiation.

Effects of Acid Treatment on Dental Zirconia: An In Vitro Study.

The aim of this study was to evaluate the effects of hydrofluoric (HF) acid, acetic acid, and citric acid treatments on the physical properties and structure of yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) at ambient temperature. In total, 110 bar-shaped zirconia specimens were randomly assigned to 11 groups. The specimens in the control group (C) received no surface treatment, while those in the Cage group were hydrothermally aged at 134°C and 0.2 MPa for 20 h. Ten specimens each were immersed at ambient temperature in 5% and 40% HF acid for 2 h (40HF0), 1 day (5HF1, 40HF1), and 5 days (5HF5, 40HF5), while 10 each were immersed at ambient temperature in 10% acetic acid and 20% citric acid for 7 (AC7, CI7) and 14 days (AC14, CI14). X-ray diffraction (XRD) was used to quantitatively estimate the monoclinic phase. Furthermore, flexural strength, surface roughness, and surface Vickers hardness were measured after treatment. Scanning electron microscopy (SEM) was used to characterize the surface morphology. The Cage group specimens exhibited an increased monoclinic phase and flexural strength. Furthermore, 40% HF acid immersion decreased the flexural strength and surface hardness and deteriorated the surface finish, while 5% HF acid immersion only decreased the surface hardness. All the HF acid-immersed specimens showed an etched surface texture on SEM observations, while the other groups did not. These findings suggest that the treatment of Y-TZP with 40% HF acid at ambient temperature causes potential damage, while treatment with 5% HF acid, acetic acid, and citric acid is safe.

Coupling of 10-methacryloyloxydecyldihydrogenphosphate to tetragonal zirconia: Effect of pH reaction conditions on coordinate bonding.

OBJECTIVES: Identification of the mechanism of chemical coupling of a phosphate ester monomer to zirconia via a computational modeling approach enables materials scientists to design new coupling agents that can resist hydrolytic degradation of bonds made by methacrylate resins to zirconia. We investigated the possibility of chemical bonding between 10-methacryloyloxydecyldihydrogenphosphate (MDP) and tetragonal zirconia, and the effect of pH reaction conditions on such prospective chemical bonds. METHODS: A tetragonal zirconia crystal model was created. An "Our-own N-layered integrated molecular orbital and molecular mechanics" (ONIOM) method was used to simulate two potential configurations of the MDP-ZrO2 system: double-coordinate and single-coordinate. Thermodynamic calculations were used to ascertain if the reaction could proceed spontaneously and to compare the stability of the two possible configurations. Short-term testing of shear bond strength (SBS) was done to evaluate bonding improvement of MDP to alumina-sandblasted zirconia surfaces in neutral, acidic or alkaline environments. RESULTS: Digital models of coordinate bonds between MDP and tetragonal zirconia were constructed. Thermodynamic calculations indicated that the Gibbs free energy for forming double-coordinate and single-coordinate configurations were -461.2kJ/mol and -450.9kJ/mol, respectively. Equilibrium constants for the double-coordinate and single-coordinate configurations were 6.4×10(80) and 9.8×10(78), respectively. Application of MDP in alkaline conditions showed the highest SBS, whereas acid conditions resulted in lower SBS. SIGNIFICANCE: MDP can establish a "true" chemical bond with zirconia spontaneously. The double-coordinate configuration was identified to be more energetically favorable than the single-coordinate configuration for the coupling of MDP to zirconia. Alkaline conditions may positively affect formation of MDP-ZrO2 coordination bonds.

[Methylation and expression of gene p16INK4a and RB in breast carcinoma].

OBJECTIVE: (1) To investigate the promoter methylation status of gene p16(INK4a) and gene RB in breast carcinoma and the adjacent non-neoplastic hyperplastic epithelial tissue. (2) To study the correlation of p16(INK4a) gene expression at protein level with the abnormal gene methylation, the clinical manifestation and the pathological parameters. METHODS: Methylation status of promoters of p16(INK4a) gene and RB gene was detected by using methylation specific PCR in 46 cases of breast cancer, 22 cases of the adjacent non-neoplastic hyperplastic epithelium tissue and 7 cases of normal breast tissue. In addition, the p16(INK4a) gene protein expression level was also detected using immunohistochemical technique(SP method) in 46 cases of breast cancer and 22 cases of the adjacent hyperplastic epithelial tissue. RESULTS: The methylation rate of p16(INK4a) gene was 23.9% (11/46) in breast cancer, 18.2% (4/22) in the adjacent non-neoplastic hyperplastic epithelial tissue and 1/7 in normal breast tissue, respectively. The methylation rate of RB gene was relatively low, which was 10.8% (5/46), 9.1% (2/22) and 0(0/7) in the above 3 groups, respectively. Methylation rate of p16(INK4a) gene and RB gene was not significantly different among the breast cancer, the adjacent non-neoplastic hyperplastic tissue and the normal tissues (P > 0.05). However, the methylation status of p16(INK4a) gene was closely correlated with its protein expression level and the negative ER expression result of the breast cancer (P < 0.05), but not correlated with the size of the cancer, differentiation status, lymph node metastasis, and age. The methylation status of RB gene was correlated with lymph node metastasis, but not with the size, the differentiation status, ER expression of the breast cancer and the age of the patients. CONCLUSIONS: The abnormal methylation of p16(INK4a) gene may not play a significant role in the early stage of breast cancinogenesis, but may play a role of in the progression of the cancer. RB gene methylation may also be a indicator in choice to identify the progression and prognosis of breast cancer.

[Controlling effects of plant extracts and pesticides on Myzus persicae and Lipaphis erysimi populations].

This paper studied the controlling effects of Xanthium sibiricum and Syngonium podophyllum ethanol extracts, mobile oil emulsion and 0.3% azadirachtin EC on Myzus persicae and Lipaphis erysimi populations both in laboratory and in field. The results showed that in laboratory, X. sibiricum extract was the key deterrent to Myzus persicae, while sprayed it with S. podophyllum extract and with petroleum spray oil or 0.3 % azadirachtin EC, the deterrent effect could be improved. As for pterigota Lipaphis erysimi, the extracts of the two plants were the main deterrents, and their interference effect was non-linear. In field, S. podophyllum extract had a stronger deterrent effect when sprayed independently. L. erysimi population could be successfully controlled by the mixtures of plant extracts and insecticides, with an efficiency of 95.7%. The best treatment against M. persicae population was X. sibiricum extract, with an efficiency of 87%, while S. podophyllum extract mixed with 0.3% azadirachtin EC, and X. sibiricum extract mixed with 0.3% azadirachtin EC had an efficiency of >80%.

[Suppressive effects of non-preferable plant alcohol extracts on diamondback moth Plutella xylostella population].

In this paper, a life table and an interference index of population control (IIPC) were used to evaluate the effects of spraying the alcohol extracts of non-preferable plants on the dynamics of diamondback moth Plutella xylostella) population. The results showed that the alcohol extracts of Eupatorium odoratum, Lantana camara and Wedelia chinensis were available to protect kidney bean from Plutella xylostella infestation. Their IIPC were 0.110, 0.136 and 0.165, and the efficacies of controlling P. xylostella were 89.0%, 86.4% and 83.5%, respectively, compared with control.

Mitochondrial DNA sequence polymorphisms of five ethnic populations from northern China.

To study the mitochondrial DNA (mtDNA) polymorphisms in a total of 232 individuals from five ethnic populations (Daur, n=45; Ewenki, n=47; Korean, n=48; Mongolian, n=48; Oroqen, n=44) in northern China, we analyzed the control region sequences and typed for a number of characteristic mutations in coding regions (especially the region 14576-16047), by direct sequencing or restriction-fragment-length-polymorphism (RFLP) analysis. With the exception of 14 individuals belonging to the European-specific haplogroups R2, H, J, and T, the mtDNAs considered could be assigned into the East Asian-specific haplogroups described recently. The polymorphisms in cytochrome b sequence were found to be very informative for defining or supporting the haplogroups status of East Asian mtDNAs in addition to the reported regions 10171-10659 and 14055-14590 in our previous study. The haplogroup distribution frequencies varied in the five ethnic populations, but in general they all harbored a large amount of north-prevalent haplogroups, such as D, G, C, and Z, and thus were in agreement with their ethnohistory of northern origin. The two populations (Ewenki and Oroqen) with small population census also show concordant features in their matrilineal genetic structures, with lower genetic diversities observed.

[Natural increase of parasitoids population of diamondback moth Plutella xylostella under ecological control condition].

The parasitoids of diamondback moth Plutella xylostella was unfolded year after year since a series of ecological measurement was taken in Shenzhen Longgang Demonstrate Ecological Farm. The parasitical eggs of diamondback moth by Trichogrammatoidea bactraz and Trichogramma ostrinae were firstly found in the field in September 1999. Another two parasitoids, Trichogramma confusum and Trichogramma bilingensis also had a certain parasitism in nature. Now, the four Trichogramma species had already established their natural population, and their average parasitism was 15% around the year, and reached 25-30% at the harvesting period in Autumn, among them, Trichogramma confusum was predominant in quantity, which showed that ecological control played an important role in augmenting and protecting the population of Trichogramma in nature.