Detection and monitoring of SARS coronavirus in the plasma and peripheral blood lymphocytes of patients with severe acute respiratory syndrome.
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Adolescent↗
Biomedical subjects
Zhiguo Liu
Publications and source records attributed to Zhiguo Liu.
Enhanced osteoblast functions on RGD immobilized surface.
Many methods are currently under investigation to improve the integration of dental implants to surrounding bones. Among these methods, peptide-modified surfaces have been highlighted as one of the most promising. Our study, aimed at the cellular response to RGD-immobilized surface in vitro, investigated the basis for designing a bone-active surface coating with RGD-containing peptide. Gold-coated titanium surfaces were used as indicative control surfaces for peptide immobilization. Using self-assembly monolayer techniques, 2 types of peptides, RGDC (Arg-Gly-Asp-Cys) and RDGC (Arg-Asp-Gly-Cys), were immobilized onto the gold surfaces. Surface justification was realized through X-ray photoelectron spectroscopy and Fourier transform infrared spectra. Primary calvarial osteoblasts were cultured on RGDC, RDGC, and non-peptide-coated surfaces. Cell attachment, morphology, proliferation, and expression of osteocalcin (OC) messenger RNA (mRNA) were assessed using cell counting, immunolabeling fluorescence microscopy, and Northern blot assay. Four and 8 hours after culture, cell attachment was enhanced on RGDC surfaces. Correspondingly, increased cell spreading and significantly greater cell proliferation were also observed in cells grown on the RGDC-coated surfaces. More importantly, osteoblasts on RGDC surfaces showed earlier and significant OC mRNA expression at day 15 compared with controls having the similar expression at day 21. These results provided evidence of the enhanced functions of osteoblasts cultured on the RGDC-modified surfaces, which might be effective in improving osseointegration for dental implants.
Amino Acid Sequence↗
[Construction of recombinant caspases-3 gene and the test of its apoptotic activity in pancreatic carcinoma cell strain].
To explore the new gene therapeutic method for pancreatic carcinoma, the recombinant Caspases-3 gene (r-Caspases-3) was constructed by molecular biologic method. The eukaryotic expression plasmid pcDNA 3.1 (+)/r-Caspase-3 was constructed by rearrangement of the large subunit and small subunit of caspases-3, and then it was transfected into pancreatic carcinoma cells strain (PC-II). After being transfected, the expression of r-Caspase-3 mRNA in pancreatic carcinoma cells was detected by RT-PCR and its apoptotic activity was detected by FCM. The sequencing of the recombinant molecules (r-Caspases-3) confirmed that its small subunit preceded its large subunit. After the pancreatic carcinoma cells were transfected with the pcDNA3.1(+)/r-Caspases-3 by liposomes, an 894 bp strap was observed by means of RT-PCR. No strap was found in control groups. A transparent hypodiploid karyotype peak was revealed by FCM. The above data indicate that the gene of r-Caspase-3 has been constructed successfully, r-Caspase-3 has apoptotic activity and can be used as target gene in gene therapy for pancreatic carcinoma.
Apoptosis↗
Bovine papillomavirus type 1 E6-induced sensitization to apoptosis is distinct from its transforming activity.
The bovine papillomavirus type 1 (BPV-1) E6 oncoprotein induces tumorigenic transformation of murine C127 cells and stimulates transcription when targeted to a promoter. We have previously shown that C127 cells expressing BPV-1 E6 exhibited increased tumor necrosis factor alpha (TNF)-mediated apoptosis. To understand the mechanisms by which BPV-1 E6 sensitizes cells to apoptosis and to investigate the relevance of E6-enhanced apoptosis to its other biological activities, we analyzed a BPV-1 E6 mutant (491, with four amino acids deleted at the C-terminus) for its ability to sensitize C127 cells to apoptosis. The result was then compared with the E6 mutant's ability to transform cells, to activate transcription, and to associate with known cellular binding proteins. Our data indicated that the transcriptional activation function of BPV-1 E6 correlated with sensitization of cells to TNF-mediated apoptosis. Moreover, functions required for BPV-1 E6-mediated sensitization of cells to apoptosis are distinct from those required for transformation. A potential role of paxillin in E6 sensitization of cells to apoptosis is implicated. These results thus indicate that sensitization of cells to TNF-induced apoptosis represents a novel function of BPV-1 E6.
Animals↗
Reconstruction and transplantation of composite skin containing keratinocytes and fibroblasts.
OBJECTIVE: To investigate the role of fibroblasts in reconstruction of composite skin, and evaluate the effect of composite skin on full-thickness skin defect. METHODS: Keratinocytes and fibroblasts were seeded on the surface of acellular dermal matrix and cultivated in vitro to reconstruct the composite skin. Adherence of keratinocytes to dermal matrix was observed. Then take rate and histological construction were investigated after the composite skin was used to cover full-thickness skin defect wound in nude mice (n = 16). RESULTS: Keratinocytes grew and proliferated to reach tho confluence on the surface of the acellular dermal matrix. Keratinocytes adhered more stablely and could not be torn down from dermal matrix in operation when few fibroblasts were seeded on the epidermal surface of the dermal matrix. After grafting, the composite skin closed the full-thickness wound in nude mouse. The total survival was achived in 10 mice (62.5%). The newly generated skin was with intact histological construction of base membrance containing laminin and type IV collagen. CONCLUSION: Composite skin could close the full-thickness wound, and fibroblasts could improve adherence of keratinocytes to dermal matrix, which should benefit the survival of composite skin.
Animals↗