ABSTRACT
Objective To explore whether phenylalanine affect Cdc42, Racl, and RhoA expression and disturb dendritic development. To determine the effects of brain-derived neurotrophic factor (BDNF) on this process. Methods Neurons were cultivated up to 3 days and then treated with 0.9 mmol/L phenylalanine or 100 ng/ml BDNF. Dendritic number were determined by morphologic analysis. Cdc42, Racl, and RhoA protein expression were examined by Western blotting analysis. ResultsThe number of dendrites in cultured neurons reduced two days after being treated with phenylalanine,while BDNF could rescue this change(P < 0.01), furthermore, BDNF was found to inhibit phenylalanineinduced down-regulation of Cdc42, Racl, and RhoA protein expression(P < 0.01). Conclusions Our study indicated that the protective effect of BDNF against phenylalanine-induced neuronal injury is probably mediated by expression of Cdc42, Racl,and RhoA. It suggested a potential neuroprotective action of BDNF in prevention and treatment of brain injury in the patients with phenylketonuria.
ABSTRACT
BACKGROUND: Previous experiments demonstrated that low-temperature isotropic pyrolytic carbon has excellent biological features. However, the research regarding low-temperature isotropic pyrolytic carbon prosthesis in hip joints, especially the biological features following hemiarthroplasty are poorly understood. OBJECTIVE: Utilizing implantation experiment, the aim of this study was to investigate the biocompatibility, as well as the interface wear properties of carbon femoral head prosthesis, coated with low-temperature isotropic pyrolytic carbon (silicon). DESIGN, TIME AND SETTING: In vivo hemiarthroplasty, randomized controlled animal experiment. The experiment was performed at the Experimental Animal Center, the Second Military Medical University of Chinese PLA, from October 2008 to April 2009. MATERIALS: Carbon femoral head prostheses.were supplied by Jilin Central Hospital. The carbon femoral head prosthesis was coated with low-temperature isotropic pyrolytic carbon. METHODS: Carbon femoral head prostheses were implanted in 16 adult New Zealand white rabbits. The rabbits were sacrificed at weeks 6 (n=4), 11 (n=6), 21 (n=6), respectively. Rabbits in the 21-week group were induced to move from 18 weeks with 2 hours per day. MAIN OUTCOME MEASURES: The biocompatibility and the interface wear phenomena of the prostheses were investigated by general observation, X-ray observation and tissue slice observation. RESULTS: The carbon femoral head prostheses implanted in animals produced non-toxic side effects, without significant inflammatory response or foreign body reaction. Furthermore, new cartilage tissue around carbon prosthesis was found, while there was no obvious wear debris after sports experiments. CONCLUSION: The film coating carbon materials have excellent biocompatibility and good wear resistance as femoral head prosthesis. Thus, it is a kind of promising biomaterials in prosthesis manufacturing.