Periodontal ligament stem cell-mediated treatment for periodontitis in miniature swine.
ABSTRACT Periodontitis is a periodontal tissue infectious disease and the most common cause for tooth loss in adults. It has been linked to many systemic disorders, such as coronary artery disease, stroke, and diabetes. At present, there is no ideal therapeutic approach to cure periodontitis and achieve optimal periodontal tissue regeneration. In this study, we explored the potential of using autologous periodontal ligament stem cells (PDLSCs) to treat periodontal defects in a porcine model of periodontitis. The periodontal lesion was generated in the first molars area of miniature pigs by the surgical removal of bone and subsequent silk ligament suture around the cervical portion of the tooth. Autologous PDLSCs were obtained from extracted teeth of the miniature pigs and then expanded ex vivo to enrich PDLSC numbers. When transplanted into the surgically created periodontal defect areas, PDLSCs were capable of regenerating periodontal tissues, leading to a favorable treatment for periodontitis. This study demonstrates the feasibility of using stem cell-mediated tissue engineering to treat periodontal diseases.
Article: Absence of association with DAT1 polymorphism and response to methylphenidate in a sample of adults with ADHD.[show abstract] [hide abstract]
ABSTRACT: A polymorphism in the dopamine transporter gene (DAT1) has been previously associated with ADHD and methylphenidate has been hypothesized to block the dopamine transporter. The goal of this study was to examine whether a 40-bp variable number of tandem repeats (VNTR) of DAT1 moderate response and adverse effects associated with methylphenidate treatment of adults with ADHD. Subjects were 106 adults with ADHD enrolled in 6-week randomized placebo-controlled parallel design trials of methylphenidate (OROS and immediate release preparations). There was no evidence of an association between DAT1 VNTR and response to methylphenidate (F(2,100) = 0.04, P = 0.9). Similarly, there was no pattern of statistically significant association with DAT1 VNTR and cardiovascular or spontaneously reported adverse effects. We failed to identify an association with DAT1 and the response or tolerability of methylphenidate in adults with ADHD.American Journal of Medical Genetics Part B Neuropsychiatric Genetics 01/2007; 141B(8):890-4. · 3.70 Impact Factor
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ABSTRACT: Mesenchymal stem cells (MSCs) are able to differentiate into a variety of cell types, offering promising approaches for stem cell-mediated tissue regeneration. Here, we explored the potential of utilizing MSCs to reconstruct orofacial tissue, thereby altering the orofacial appearance. We demonstrated that bone marrow MSCs were capable of generating bone structures and bone-associated marrow elements on the surfaces of the orofacial bone. This resulted in significant recontouring of the facial appearance in mouse and swine. Notably, the newly formed bone and associated marrow tissues integrated with the surfaces of the recipient bones and re-established a functional bone marrow organ-like system. These data suggested that MSC-mediated tissue regeneration led to a body structure extension, with the re-establishment of all functional components necessary for maintaining the bone and associated marrow organ. In addition, we found that the subcutaneous transplantation of another population of MSCs, the human periodontal ligament stem cells (PDLSCs), could form substantial amounts of collagen fibers and improve facial wrinkles in mouse. By contrast, bone marrow MSCs failed to survive at 8 weeks post-transplantation under the conditions used for the PDLSC transplantation. This study suggested that the mutual interactions between donor MSCs and recipient microenvironment determine long-term outcome of the functional tissue regeneration. Disclosure of potential conflicts of interest is found at the end of this article.Stem Cells 05/2007; 25(4):1021-8. · 7.78 Impact Factor
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ABSTRACT: Human post-natal stem cells possess a great potential to be utilized in stem-cell-mediated clinical therapies and tissue engineering. It is not known whether cryopreserved human tissues contain functional post-natal stem cells. In this study, we utilized human periodontal ligament to test the hypothesis that cryopreserved human periodontal ligament contains retrievable post-natal stem cells. These cryopreserved periodontal ligament stem cells maintained normal periodontal ligament stem cell characteristics, including expression of the mesenchymal stem cell surface molecule STRO-1, single-colony-strain generation, multipotential differentiation, cementum/periodontal-ligament-like tissue regeneration, and a normal diploid karyotype. Collectively, this study provides valuable evidence demonstrating a practical approach to the preservation of solid-frozen human tissues for subsequent post-natal stem cell isolation and tissue regeneration. The present study demonstrates that human post-natal stem cells can be recovered from cryopreserved human periodontal ligament, thereby providing a practical clinical approach for the utilization of frozen tissues for stem cell isolation.Journal of Dental Research 11/2005; 84(10):907-12. · 3.49 Impact Factor