ABSTRACT
BACKGROUND: Previous research has investigated the effect of nano-zirconium dioxide-toughened hydroxyapatite (nano-ZrO2-HA) on the proliferation and differentiation of rabbit bone marrow stromal cells.OBJECTIVE: To evaluate the biocompatibility of nano-ZrO_2-HA compound.METHODS: The experiments of acute toxicity,subacute toxicity,pyrogen,hemolysis,and intramuscular implantation were performed on New Zealand rabbits,healthy adult Kunming mice,and adult rats according to "Technical Evaluation Standards of Biomedical Materials and Medical Instruments",promulgated by Chinese Board of Health.RESULTS AND CONCLUSION: Acute toxicity: All experimental animals survived.There was no significant difference in body mass before and after testing (P> 0.05).Pyrogen: Heating reaction was not tested.Hemolysis: Generally speaking,hemolytic crisis was not observed after 1 hour,and hemolytic rate was less than 5%.Intramuscular implantation: Infection did not occur in any animals,and materials were not discharged at all.Four weeks later,muscles were closely integrated with materials.A certain quantity of tissue grew into material pore,and peripheral muscle still had normal morphology and structure.Subacute toxicity:There was no significant difference in body mass and blood routine before and 2 weeks after testing.HE staining demonstrated that necrotic focus and other lesion were not observed in heart,liver,and kidney tissues under optic microscope.The results suggested that nano-ZrO_2-HA was non-toxicity,and it had no pyrogen and hemolysis effect,as well as it did not stimulate to the muscle of rabbit.Inflammatory rejection did not happen to the animal.The nano-ZrO_2-HA was closely integrated with the muscle,characterizing by great biocompatibility.Therefore,it can be used as substitution materials in clinical experiment.But it still needs to be evaluated completely.
ABSTRACT
Objective: To study the effect of TIP30 gene on the cell cy cle distribution in adenoid cystic carcinoma ACC-M cells. Methods: Wild type TIP30 gene was transfected into ACC-M cells by using lipofectamin e, the postive cell clone was selected with G418,the expression of TIP30 protei n in the cells was detected by Western blot. Cell cycle distribution was detecte d by flow cytometry. Results:14 days after seletion anti-G418 c ell clone was obtained. Wstern blot revealed that the TIP30 protein was expresse d in the transfected cells.Flow cytometric analysis indicated that TIP30 induced a arrest of the cells in G 0-G 1 phase and led to a decrease of cell percent age in G 2-M and S phase. Conclusion:ACC-M can stably express exogene TIP30.TIP30 can inhibit proliferation of ACC-M cells.
ABSTRACT
objective: To develop an accurate, reliable and efficient carotid artery compression training device .Methods:Adopting present technology for production of skin dilators in combination with anatomical characters of human carotid artery, an implantable carotid artery training occluder (ICATO) was designed and manufactured. The mechanical properties were tested and the carotid artery occlude effect was investigated in 12 dogs. Results: The expansion stress of the water cyst and duct of the occluder was 40 kPa, that of the water imput valve 30 kPa,tear stress of the nylon cloth was 5 kg. The carotid artery could be completely blocked at the pressure of 19 kPa produced by the occluder. Conclusion: ICATO can obstruct carotid artery for the purpose of compression training of carotid artery.
ABSTRACT
Objective: To construct attenuated salmonella typhimurium haboring an eukaryotic co-expression plasmid encoding TIP30 and human IFN-? gene and observing its effect on the growth of adenoid cystic carcinoma. Methods: The TIP30 and human IFN-? genes were amplified by PCR and inserted into eukaryotic expression vector pCI-neofor the construction of expression plasmids pCI-TIP30 and pCI-IFN, respectively. A co-expression plasmid pCI-TIP30/IFN was constructed by linking TIP30 and human IFN-? gene using the sequence of internal ribosome binding sequence (IRES). Three recombinant expression plasmids were transformed into an attenuated AroA'autotrophic mutant of salmonella typhimurium SL7207, the resultant bacteria were used to infected murine macrophage in vitro and the expressed products were detected by Western blot and ELISA, respectively. Tumor growth was observed by oral administration of the recombinant salmonella typhimuriums to the nude mouse with adenoid cystic carcinoma. Results: Murine macrophage infected with recombinant salmonella transformed with both plasmids pCI-TIP30 and pCI-TIP30/IFN could express TIP30 protein, and murine macrophage infected with recombinant salmonella transformed with pCI-IFN or pCI-TIP30/IFN could secret human IFN-? in the culture supernatant. Attenuated salmonella typhimurium and three constructed recombinant salmonella typhimuriums all had evident inhibition onthe tumor growth in nude mouse with adenoid cystic carcinoma. Conclusion: The recombinant attenuated salmonella typhimuriums haboring plasmid pCI-TIP30, plasmidpCI-IFN and co-expressing plasmidp-CI-TIP30/IFN were successfully constructed, which could inhibit the growth of adenoid cystic carcinoma in nude mouse.