Objective:To investigate the in vitro effects of platelet-rich plasma(PRP) on human periodontal ligament fibroblasts(PDLFs). Methods: Various concentrations of PRP (10, 50, 100, 200, 300, 500 ml/L) were applied to primary cultures of human PDLFs. MTT assays were utilized to assess cell proliferation ability. Migration was determined by assessing the cell response to a concentration gradient with Transwell chamber. Differentiation was assessed using alkaline phosphatase (ALP) kit. Results: A beneficial effect on proliferation was observed, especially in response to 200 ml/L PRP.PRP had stimulatory effects on the migration of human PDLFs. PRP facilitated differentiation of PDLFs. Conclusion: PRP can exert a positive effect on human PDLFs,but this effect is concentration specific, while higher concentrations is not necessary to result in optimal outcomes.

OBJECTIVEDuring 2003-2005, an outbreak of meningitis due to Neisseria meningitidis serogroup C occurred in China. With the aim to find strain clues result in the final epidemics, the ancestral strain 053442, a clinical isolate, and a carrier strain 053426 with different gene type were analyzed.

METHODSClinical strain 053442 and carrier strain 053426 were cultured on GC agar plates under the same condition. Two-dimensional electrophoresis was performed using the pH 3-10 nonlinear IPG strips of 24 cm length, and all the protein spots were identified by matrix-assisted laser desorption/ionization time of flight spectrometry.

RESULTS502 and 380 protein spots were identified in 053426 and 053442 respectively, relating to 266 and 202 different genes covering a wide range of cellular functions. The express volume and number of proteins involved in energy metabolism, protein synthesis and amino acid biosynthesis in 053426 were higher than in 053442. Virulence factor Opa, Opc and a series of proteins involved in pilus assembly and retraction were identified in 053442, which appear to be of primary importance in colonization and invasion of human cells. Compared to 053442, virulence protein species were less in 053426, with lower express volumes too. No Opa and Opc were detected in 053426.

CONCLUSIONSThe different protein expression profiles of the clinical strain 053442 and carrier strain 053426 in the present study provide some clues of the different pathogenicity of the two strains, which may account for result in the final epidemics.

Bacterial Proteins ; analysis ; Bacterial Typing Techniques ; China ; epidemiology ; Disease Outbreaks ; Electrophoresis, Gel, Two-Dimensional ; Humans ; Meningitis, Meningococcal ; cerebrospinal fluid ; epidemiology ; microbiology ; Neisseria meningitidis, Serogroup C ; classification ; isolation & purification ; Proteome ; analysis ; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization