Adipose tissue contains a population of multipotent cells called adipose-derived stem cells (ADSCs). With the similar properties of marrow-derived mesenchymal stem cells, ADSCs have the ability to differentiate differentiate towards adipogenic, osteogenic, chondrogenic, myogenic, endothelial, hematopoietic, hepatic, islet, and neurogenic cell lineages. As adipose tissue in harvested in large amounts with minimal morbidity, it can be widely used in tissue engineering, organ repair and gene therapy. This paper focused on the plasticity of ADSCs and reviewed the new advances of this field. Finally, the problems and prospect for application was also discussed.
Adipose Tissue ; cytology ; metabolism ; Animals ; Antigens, CD ; metabolism ; Cell Culture Techniques ; Cell Differentiation ; Genetic Therapy ; Humans ; Multipotent Stem Cells ; cytology ; metabolism ; Stem Cells ; cytology ; metabolism ; Tissue Engineering

Collagen is the most abundant protein in human body and a periodic helix, i. e. , triple helix, fibrous protein, which provides the scaffold structures for the cell adhesion and macromolecule aggregation, etc. With the development of gene engineering and biomaterial technologies, and the incessant studies on the technique to obtain the proteins with special functions, the collagen protein has been one of the third generation biomaterials that attract more attention than others. In this paper, we reviewed the recent structure-based design and biosynthesis of collagen.
Animals ; Biotechnology ; methods ; Collagen ; biosynthesis ; chemistry ; genetics ; Humans ; Models, Biological ; Models, Molecular ; Protein Conformation ; Protein Stability ; Protein Structure, Secondary ; Temperature

Cyclodextrin glucanotransferase, the essential enzyme for the production of cyclodextrins, has become the focus of scientific research nowadays. Although many related enzyme properties are well known, the crucial factors in product specificity determination remain to be answered. Here, the recent research progresses of cyclodextrin glucanotransferase, especially those about the evolution of product specificity, were reviewed, and the scientific problems were discussed.
Archaeal Proteins ; genetics ; metabolism ; Bacillus ; enzymology ; genetics ; Bacterial Proteins ; genetics ; metabolism ; Biocatalysis ; Cyclodextrins ; metabolism ; Evolution, Molecular ; Glucosyltransferases ; classification ; genetics ; metabolism ; Mutation ; Thermoanaerobacterium ; enzymology ; genetics ; Thermococcus

A simple and rapid method for preparation of plasmid DNA from overnight incubation was introduced. It does not require any additional reagents; the incubation mixture containing recombinant plasmid DNA was just mixed with H2O and phenol/chloroform/isoamyl alcohol in certain ratio. After vortexing and spinning of the mixture, the supernatant could be directly loaded onto agarose gel and analyzed using electrophoresis. The whole preparation requires only 3-5 minutes. So to quickly screen recombinant clones, this method is better compared with traditional methods.
Centrifugation, Density Gradient ; Chloroform ; chemistry ; Cloning, Molecular ; methods ; DNA, Bacterial ; genetics ; isolation & purification ; metabolism ; Deoxyribonuclease HindIII ; metabolism ; Electrophoresis ; Escherichia coli ; genetics ; Pentanols ; chemistry ; Phenol ; chemistry ; Plasmids ; chemistry ; genetics ; Reproducibility of Results ; Time Factors ; Water ; chemistry

Tissue engineering is a promising technique to repair or reconstruct the damaged cartilage in clinical use. However, chondrocyte growth is limited by the mass transport in scaffolds as diffusion is likely to be the primary mechanism. In this study, a mathematical model was developed based on oxygen diffusion and reaction to simulate chondrocyte growth. In order to accord with the fact, effective diffusion coefficients and space limitation were considered in this model and good agreement was found between experimental data and mathematical simulations. Furthermore, relationships established in the model system can be used to optimize the situation in real bioreactors and the design of three-dimensional scaffolds.
Algorithms ; Animals ; Biological Transport ; Cattle ; Cell Culture Techniques ; Cell Proliferation ; Cells, Cultured ; Chondrocytes ; cytology ; metabolism ; Diffusion ; Models, Biological ; Oxygen ; metabolism ; Time Factors ; Tissue Engineering ; methods ; Tissue Scaffolds ; chemistry

A reliable, low-cost, and highly efficient nonviral gene delivery system using lower molecular weight polyethylenimine (LMW-PEI) is provided. LMW-PEI was linked to an expressing plasmid with green fluorescence protein gene (gfp), the transfection activity mediated by PEIs were examined in the CM7721 cell line and the skin tissue of mouse, respectively. The cytotoxicity of PEIs, the localization and continuance time of gfp expressed in the skin tissue of mouse were also studied. Results showed that the transfection rate of gfp mediated by LMW-PEI in the CM7721 cell line was about 55% . However, with the increasing PEI molecular weight, the cytotoxicity of PEI increased, but its transfection activity decreased. The tissue transfection results showed that LMW-PEI induced a significant expression of the gfp in the cells of hair vesicle and sweat gland of mouse skin tissues following transfection of 24 h, and the expression of gfp lasted 7 - 9 d. When the tissue of mouse was treated with retinoic acid and nitrogenous ketone, respectively, gfp was transferred to the granule layer of mouse skin tissue. The LMW-PEI described here is a new, highly efficient vector; it would be a useful nonviral vector for gene delivery technology.
Animals ; Cell Line, Tumor ; Cell Survival ; drug effects ; Gene Transfer Techniques ; Green Fluorescent Proteins ; genetics ; metabolism ; Immunohistochemistry ; Mice ; Microscopy, Fluorescence ; Molecular Weight ; Plasmids ; chemistry ; genetics ; Polyethyleneimine ; chemistry ; toxicity ; Skin ; metabolism

Previous methods used for nuclear transplantation were further investigated to develop a method that was both easy to carryout and did not require any special apparatus, such as Piezoimpact or Spindle-View. Following the puncture of zona pellucida with two holes by injection pipette that contained donor nuclei or cells, the injection pipette was pulled back to the perivitelline space while the negative pressure was increased in the holding pipette until the polar body and karyoplasm were wiped off completely. Then a reconstructed embryo was completed by the direct injection of the donor nucleus or cell without pulling out the injection pipette. 200 oocytes were manipulated using this method and it cost about 40 seconds with nucleus injection and about 30 seconds with cell injection to complete a reconstructed embryo. The success rates were 62.6% and 86. 0%, respectively, and enucleation rate was about 73.3% validated by Hoechst 33342. Using this method, the nucleus was completely eliminated and another was injected using the microscope and micromanipulator. Moreover, the efficiency of nuclear transplantation and survival rate of reconstructed embryos were greatly improved. Furthermore, it is very easy to manipulate and popularize in practice.
Animals ; Cell Culture Techniques ; methods ; Cell Nucleus ; metabolism ; Cells, Cultured ; Cloning, Organism ; methods ; Embryo, Mammalian ; cytology ; metabolism ; Embryonic Development ; Female ; Male ; Mice ; Mice, Inbred C57BL ; Mice, Inbred DBA ; Mice, Inbred Strains ; Nuclear Transfer Techniques ; Oocytes ; cytology ; metabolism ; Zona Pellucida ; metabolism

The commonly used plant constitutive expression vector pBI121 was modified by insertion of two directly orientated lox sites each at one end of the selectable marker gene NPTII and by replacing the GUS gene with a sequence composed of multiple cloning sites (MCS). The resulting plant expression vector pBI121-lox-MCS is widely usable to accommodate various target genes through the MCS, and more importantly to allow the NPTII gene removed from transformed plants upon the action of the Cre recombinase. In addition, the CaMV 35S promoter located upstream of the MCS can be substituted with any other promoters to form plant vectors with expression features specified by the introduced promoters. Provided in this paper is an example that an enhanced phloem-specific promoter of the pumpkin PP2 gene (named dENP) was used to construct an NPTII-removable phloem-specific expression vector pBdENP-lox-MCS. Moreover, to facilitate screening of selectable marker-removed gene and the composite sequence is flanked by lox sites. Thus the selectable marker-free plants can be visually identified by loss of GFP fluorescence. The above newly created plant expression vectors can be used to develop selectable marker-removable transgenic plants for a variety of purposes.
Attachment Sites, Microbiological ; genetics ; Binding Sites ; genetics ; Cloning, Molecular ; Gene Knockout Techniques ; methods ; Genes, Plant ; genetics ; Genetic Markers ; genetics ; Genetic Vectors ; genetics ; Green Fluorescent Proteins ; genetics ; metabolism ; Integrases ; genetics ; metabolism ; Plants ; genetics ; Plants, Genetically Modified ; genetics ; Recombination, Genetic

Two hydrogen-producing bacterial strains were newly isolated and identified as Enterobacter sp. Z-16 and Clostridium sp. C-32 by 16S rDNA sequence analysis. Various parameters for hydrogen production, including substrates, initial pH and temperature, have been studied. The optimum condition for hydrogen production of strain Z-16 were achieved as: initial pH7.0, temperature 35 degrees C , sucrose as the favorite substrate. In comparison, The optimum condition for hydrogen production of strain C-32 were obtained as: initial pH8.0, temperature 35 degrees C , maltose as the favorite substrate . Under batch fermentative hydrogen production conditions, the maximal hydrogen conversion rate for strain Z-16 and strain C-32 were 2.68 mol H2/mol sucrose and 2.71mol H2/mol maltose, respectively. Using glucose as substrate, the hydrogen conversion rate of strain Z-16 and strain C-32 were 2.35 and 2.48 mol H2/mol glucose, respectively. This research suggest a good application potential of strain Z-16 and C-32 in the future biological hydrogen production.
Clostridium ; isolation & purification ; metabolism ; ultrastructure ; Enterobacter ; isolation & purification ; metabolism ; ultrastructure ; Fermentation ; Glucose ; metabolism ; Hydrogen ; metabolism ; Hydrogen-Ion Concentration ; Maltose ; metabolism ; Microscopy, Electron, Transmission ; Polymerase Chain Reaction ; RNA, Ribosomal, 16S ; genetics ; Species Specificity ; Sucrose ; metabolism ; Temperature

The invertebrate parvovirus Bombyx mori Densonucleosis Virus type 3(Zhenjiang isolate), named BmDNV-3, is a kind of bidensovirus. The most obvious characteristic in the genome of BmDNV-3 is that it has 2 sets of DNA molecular (VD1, VD2),and each of them is encapsidated respectively in the form of single-stranded liner DNA ( + VD1, - VD1, + VD2, - VD2) in equal percentage. So the BmDNV-3 has 4 kinds of virions. Furthermore the sequence of BmDNV-3 is able to encode DNA polymerase itself. Some strains of silkworm revealed complete resistance to BmDNV-3, so they didn' t fall sick. To investigate the difference in the process of infection and replication between the 2 virions ( VD1, VD2) of this bidensovirus, and the difference of the increment in the resistant or susceptible host, the 5th instar larvae of the susceptible silkworm strain (HUABA 35) and the resistant silkworm strain(QIUFENG d) were inoculated determinate dose of BmDNV-3 by oral ingestion. Then the midgut were collected at 9 timepoints. The silkworm cytoplasm actin A3 was used to be normalized gene, so the number of cells in collected tissue could be determined. The result shows that whatever in the susceptible silkworm strain or in the resistant one, the copies of VD1 and VD2 in the genome of BmDNV-3 collected at the different timepoint were almost at the equal level respectively, so that the VD1 and VD2 were replicated with synchronization. The process of infection in the susceptible silkworm strain was devided into 3 partitions, latent period( 2 - 12 hours post inoculation), exponential phase (12 - 36 hours post inoculation)and stationary phase (36- 96 hours post inoculation and there are about 2 x 10(5) copies per cell) . In the resistant silkworm strain, the virus were replicated at a very low level, that was from 6 - 10 copies 2 hours post inoculation to 150 - 200 copies 96 hours post inoculation (about 20 times) . So we predict that the resistance in some of the silkworm strains from BmDNV-3 was a kind of chronic representation that the host carried virus without being caused flacherie.
Animals ; Bombyx ; genetics ; virology ; DNA, Viral ; genetics ; Densovirus ; genetics ; physiology ; Female ; Genome, Viral ; genetics ; Host-Pathogen Interactions ; Male ; Polymerase Chain Reaction ; methods ; Time Factors ; Virion ; genetics ; physiology ; Virus Replication ; genetics