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Currently, nanobioceramics have received much attention due to their potentially high biological performance. In the present study, the interactions between proteins and two types of hydroxyapatite (HA) ceramic particles with distinct microstructures were studied in vitro. Protein adsorption on the microwave sintered and conventionally sintered HA ceramic particles (named as HAMS and HACS, respectively) were carried out in simulated body fluid (SBF) containing model proteins or rat serum and then subjected to protein quantitative evaluation, SDS-PAGE, and Western blotting analysis. The ceramic particles were characterized by nitrogen sorption, Hg penetration, zeta potential, and solubility analysis. It was found that HAMS with nanosized crystallites had greater specific surface area and pore volume and wider pore size distribution ranging from 0.02 to 2 μm than HACS. Although bovine serum albumin and lysozyme have different electrical properties in SBF, both the model proteins showed higher adsorption amounts per gram solid on HAMS than HACS, as could be ascribed to the contribution of the micropores structure of HAMS. Similarly, HAMS adsorbed more serum proteins per gram solid than HACS when incubating in rat serum, and here the surfaces of both particles were almost completely covered by serum proteins, leading to almost the same protein adsorption amounts per unit area solid of HAMS and HACS. SDS-PAGE patterns proved that HA ceramic particles had different binding capacities for different serum proteins and was not highly dependent on the concentrations of the competing protein components present in rat serum. Western blotting analysis confirmed the enhanced adsorption of fibronectin and vitronectin on HAMS, indicating that HAMS might have better bioactivity than HACS. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 100B: 516-523, 2012. [ABSTRACT FROM AUTHOR]

Oval cells, putative hepatic stem cells, could potentially provide a novel solution to the severe shortage of donor livers, because of their ability to proliferate and differentiate into functional hepatocytes. We have previously demonstrated that oval cells can be induced to differentiate into cells with morphologic, phenotypic, and functional characteristics of mature hepatocytes. In this study, we have established a new model combining ethionine treatment with partial hepatectomy to activate oval cells, then developed a procedure utilizing selective enzymatic digestion and density gradient centrifugation to isolate and purify such cells from heterogeneous liver cell population. We identified oval cells by their morphological characteristics and phenotypic properties, thereby providing definitive evidence of the presence of hepatic stem-like cells in adult rat livers. Viewed by transmission electron microscopy, they were small cells with ovoid nuclei, a high nucleus/cytoplasm ratio and few organelles, including mitochondria and endoplasmic reticulum. Flow cytometric assay showed that these cells highly expressed OV-6, cytokeratin-19 (CK-19) and albumin. Reverse transcriptase-polymerase chain reaction (RT-PCR) analysis displayed that the freshly isolated cells co-expressed albumin, cytokeratin-7 (CK-7) and CK-19 mRNA, indicating that they were essentially bipotential hepatic stem-like cells. Furthermore, we set up a culture system containing growth factors and a fibroblast feeder layer, to provide nourishment to these cells. Thus, we were able to culture them in vitro for more than 3 months, with the number of cells doubling 100 times. Gene expressions of albumin, CK-7 and CK-19 in the cells derived from the expanding colonies at day 95 were confirmed by RT-PCR analysis. These data suggested that the hepatic oval cells derived from adult rat livers possess a high potential to proliferate in vitro with a large increase in number, while maintaining the bipotential nature of hepatic stem cells. [ABSTRACT FROM AUTHOR]

Examines the Y-chromosome STR haplotypes in a Han ethnic group of Chinese population. Collection of blood samples; Allelic variation at the three Y-STR loci; Gene diversities.

Cites the procedure to asses the distributions of allelic frequencies and haplotypes of three Y-short tandem repeat loci in a Chinese Han population. Blood sample collection; DNA extraction; Contents of the polymerase chain reaction (PCR) for each locus; PCR amplification; Conduction of typing using denaturing capillary gel electrophoresis; Allele designation.

Examines allele diversities and haplotypes of two novel Y-STR in a Chinese population. Collection of EDTA-blood samples from unrelated males of Han population; Use of polymerase chain reaction (PCR) amplification; Genotyping of the PCR products.

Studies the allele frequencies of two Y-short tandem repeat loci in a population in Chongqing, China. Extraction of DNA; Amplification of DNA; Analysis of the amplified products; Gene and haplotype diversities of the alleles.