Publications (7)0 Total impact
- Journal of clinical orthodontics: JCO 01/2015; 49(1):16-27.
Conference Paper: Osteogenic and dentinogenic potential of human DPSC in vitro[Show abstract] [Hide abstract]
ABSTRACT: Root canal procedures may involve treatment with EDTA to release dentin matrix molecules supporting dentin repair. Under reparative conditions, tooth pulp cells generate osteodentin. OBJECTIVE: Analyze effects of dentin extract (DE) on gene expression of human dental pulp-derived stem cells (hDPSC) induced to differentiate in vitro. METHODS: Extracted third molars of the same person were used for isolation of hDPSC. DE was prepared by dentin extraction with 10% EDTA, pH 7.2. Proliferation medium for hDPSC consisted of human mesenchymal stem cell (hMSC) basal medium (Lonza) with 10% adult human serum. Differentiation medium contained dexamethasone, ascorbate and beta-glycerophosphate either with DE (experiments, n=6) or without DE (controls, n=6). Total RNA was isolated and expression of 84 hDPSC/hMSC-specific genes was evaluated using PCR arrays (PAHS-026, SABiosciences Qiagen). Experimental and control cycle threshold (CT) values were compared using manufacturer's software. RESULTS: DE increased expression of genes involved in both osteogenic and dentinogenic differentiation pathways of hDPSC. CONCLUSION: This pilot study has shown effects of DE on gene expression of hDPSC in vitro. The analysis is continued. Identification of hDPSC genes whose expression is affected by DE helps to better understand mechanisms, by which factors released from dentin extracellular matrix may influence healing and regeneration of damaged dentin. This work was supported by the Research Pilot Project Award 03 from the UOP Arthur A. Dugoni School of Dentistry, San Francisco, CA.IADR General Session 2011; 03/2011
Conference Paper: Effect of Platelet-Rich Plasma on Human Adult MSC in vitro[Show abstract] [Hide abstract]
ABSTRACT: Introduction: A controversy exists regarding efficiency of platelet-rich plasma (PRP) in improving an outcome of bone grafting. Conditions in vitro are well suited for a study on factors and mechanisms controlling growth and osteogenic differentiation of human adult mesenchymal stem cells (MSC). Objective: To determine basic bone regeneration cellular mechanisms in vitro that may or may not be affected by addition of PRP to the cultivation medium. Methods: Cells from human bone marrow aspirates (AllCells, LLC) are isolated by Ficoll technique and are cultivated in plastic flasks or Petri dishes in the MSC Basal Medium (Lonza, Inc.) supplemented with L-glutamine (2 mM), Penicillin (10 units/mL), Streptomycin (10 microg/mL) and 10% human serum. PRP is prepared using SmartPrep2 and activated by thrombin and calcium chloride (Harvest Technologies, Inc.). Lonza's osteogenic medium contains dexamethasone, ascorbic acid and betaglycerophosphate. Cell counts are used for measurement of growth. Osteoblasts are characterized by alkaline phosphatase stain (intracellular enzyme activity) and by Von Kossa stain showing extracellular mineral deposits. Results: Addition of PRP to the cultivation medium shortened lag phase preceding multiplication of human adult MSC. Rate of multiplication and extent of osteogenic differentiation of MSC were not significantly affected. Conclusion: Shortening of lag phase preceding exponential phase of growth seems to be the main effect of PRP. Clinically, PRP is applied when bone material is grafted. The growth factors contained in the PRP may shorten the lag phase of MSC and lead to an earlier start of their exponential growth in vivo similarly as shown in vitro. ACKNOWLEDGEMENT: This work was partially supported by the Research Pilot Project Award 03-Activity 055 from the Arthur A. Dugoni School of Dentistry.IADR General Session 2009; 04/2009
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ABSTRACT: Introduction: The etiology of nonsyndromic cleft lip with or without cleft palate (NCLP) is multifactorial, including genetic and environmental factors. Folate-related genes and folate intake are among those factors intensively studied recently. Methylenetetrahydrofolate reductase (MTHFR) gene encodes the enzyme involved in a control of folate metabolism. When its function is altered due to a mutation, a decreased utilization of folate slows down cell multiplication in the early embryonic development and it may lead to an orofacial cleft. However, there is no consistency of results from studies of MTHFR677CT and NCLP. Objectives: To find out whether C677T variant of the MTHFR gene is associated with NCLP in Guatemalan population. Methods: Case-control study based on 242 individuals affected with NCLP and 218 controls identified during Rotaplast medical missions at Roosevelt Hospital in Guatemala City, Guatemala was conducted. DNA was isolated from dry blood spots on filter paper. MTHFR 677CT genotypes were established by PCR amplification and single nucleotide conformational polymorphism detection using polyacrylamide gel electrophoresis. Results: Significantly different proportion of genotypes (p=0.005) with higher proportion of TT homozygotes between cases and controls, and also significantly higher T allele frequency in cases compared to controls (p=0.003) was found. In cases, 7.44% of individuals had CC genotype, 45.87% had TT genotype, and 46.69% were heterozygotes. Proportions of genotypes in controls were 16.06% CC, 35.32 % TT, and 48.62% CT. The C allele frequency was 0.308 for cases and 0.404 for controls, while the T allele frequency was 0.692 for cases and 0.596 for controls. Conclusion: Results of this study suggest that the C677T variant of MTHFR gene is associated with NCLP in Guatemala. Acknowledgement: The fieldwork for this study was supported by Rotaplast Intl., Inc.IADR General Session 2009; 04/2009
- 10th Pacific Research Day, San Francisco; 05/2008
- Journal of the Massachusetts Dental Society 02/2006; 55(2):36-8.
Article: A ClinicoPathologic Correlation
Azusa Pacific Universityأزوسا، لوس أنجليس، كاليفورنيا, California, United States