Geriatric Medical Education and Training in the United States

Medical education in geriatrics is an important requirement to ready the profession to provide comprehensive health care to the world's and also Taiwan's aging population. The predoctoral curricula and postdoctoral training programs in the United States were developed and supported by government agencies and professional education societies. Geriatric medical education in American medical schools has improved in the past 20 years, yet is still facing many challenges. The purposes of this paper are to review the current progress of, and propose some main principles and policies for the development of geriatric medical education and current progress in the United States. Geriatric medical education should be mandatory to adequately prepare medical students, residents, fellows, and practicing physicians to treat the elderly. The current progress and practice of geriatric medical education at the University of Texas Health Science Center at San Antonio are presented as an example

Overexpression of hTERT increases stem-like properties and decreases spontaneous differentiation in human mesenchymal stem cell lines

To overcome loss of stem-like properties and spontaneous differentiation those hinder the expansion and application of human mesenchymal stem cells (hMSCs), we have clonally isolated permanent and stable human MSC lines by ectopic overexpression of primary cell cultures of hMSCs with HPV 16 E6E7 and human telomerase reverse transcriptase (hTERT) genes. These cells were found to have a differentiation potential far beyond the ordinary hMSCs. They expressed trophoectoderm and germline specific markers upon differentiation with BMP4 and retinoic acid, respectively. Furthermore, they displayed higher osteogenic and neural differentiation efficiency than primary hMSCs or hMSCs expressed HPV16 E6E7 alone with a decrease in methylation level as proven by a global CpG island methylation profile analysis. Notably, the demethylated CpG islands were highly associated with development and differentiation associated genes. Principal component analysis further pointed out the expression profile of the cells converged toward embryonic stem cells. These data demonstrate these cells not only are a useful tool for the studies of cell differentiation both for the mesenchymal and neurogenic lineages, but also provide a valuable source of cells for cell therapy studies in animal models of skeletal and neurological disorders

Biological Effects of Cementum and Bone Extracts on Human Periodontal Fibroblasts

Background: Non-collagenous proteins of mineralized tissues play important roles in bone induction during mineralization and in regulating the activity of many types of mesenchymal cells. This study was conducted to determine the effects of acetic acid extracts of bone and cementum on alkaline phosphatase (ALPase) activity and in vitro mineralization of cultured human periodontal fibroblasts (hPF). Methods: Alveolar bone and cementum obtained from clinically healthy subjects were extracted by a solution containing 0.5 M acetic acid and enzyme inhibitors. Osteoblastic phenotypes of hPF were assayed by ALPase activity, gene expression of bone marker proteins, and the ability to produce in vitro mineralization in culture media containing 50 mug/ml ascorbic acid, 10 mM sodium beta - glycerophosphate, and 10(- 7) M dexamethasone. The effects of cementum and bone extracts on the expression of osteoblastic phenotypes in hPF were also determined. Results: Many protein components, varying in molecular weight from 10 to 14 to 120 kDa, were detectable in 10% SDS-PAGE of both cementum and alveolar bone extracts. The hPF cells were found to exhibit a moderate ALPase activity when compared with rat osteosarcoma (ROS) 17/2.8 cells under the same experimental conditions. Gene expression for ALPase, osteocalcin bone sialoprotein, osteopontin, and BMP-7 at mRNA message was detected by RT- PCR in hPF and ROS 17/2.8 cells. The confluent hPF and ROS 17/2.8 cells showed evidence of calcium deposition in the extracellular milieu at 30 and 15 to 30 days' cultures, respectively, under a mineralization medium. The hPF appeared to form mineralized foci with morphological characteristics different from the mineralized nodules produced by ROS 17/2.8 cells. The addition of low concentrations (5 mug/ml ) of either cementum or bone extract produced an increase in the size and number of mineralization spots, as well. as greater ALPase activity in both hPF and ROS 17/2.8 cultures during the observation periods. Conclusions: These results suggest that hPF possess certain mineralizing phenotypes, and that acetic acid extracts of bone and cementum contain components capable of stimulating osteogenic differentiation of hPF

牙周再生術是真理 或虛構幻象

Periodontitis is a chronic bacterial infection that leads to destruction of the tooth-attachment apparatus and its supporting bone. If periodontitis-affected teeth remain untreated, it will result in progressive attachment tissue loss that eventually leads to tooth loss. According to an official viewpoint from the American Academy of Periodontology, definition of periodontal regenerative procedures (guided tissue regeneration, GTR) are used to treat periodontal osseous, furcation and recession defects, and restore the architectures and function of the lost or injured tissues. This means that the structures (gingival, periodontal ligament, cementum and bone) and function ( connection of periodontal ligament fiber attachment to the root surface for mastication) of the periodontal tissues should be restored. Since the pioneer work created by S. Nyman, Gottlow and Karring in 1980, GTR procedures have been extensively studied and applied clinically for over 20-30 years. Whether is there enough scientific evidence or the results of long-term clinical follow-up, is still subjected to controversy clinically. Therefore, this short concise paper will summarize and discuss current evidence-based literature (preclinical animal studies) and randomized, long -term (over 10 years) controlled clinical investigations. This not only provides an up -to-date overview of this issue; and also in an attempt to answer the question, does periodontal tissue regeneration really work or is only a fictitious story? Is this technique still an effective method in saving teeth and treating periodontal disease

Interleukin-1 Beta, Clinical Parameters and Matched Cellular- Histopahtologic Changes of Biopsied Gingival Tissue from Periodontitis Patients

Objective: The aim of the present study was to investigate whether interleukin (IL)-1beta in diseased tissues adjacent to periodontal pockets can reflect the degree of inflammation and destruction of these tissues pathologically . Background: IL-1beta-dependent mechanisms have been strongly implicated in contributing to inflammation and destruction of bone and attachment loss, which are characteristic features of periodontal disease. This biochemical mediator released during pro-inflammatory processes has not been objectively integrated with clinical and histopathologic features of periodontal disease. Methods : Periodontitis- affected inflamed tissue and clinically nonaffected healthy gingivae were harvested from 14 periodontal patients, respectively. The severity of tissue inflammation was illustrated by clinical parameters and cellular histologic changes and quantified by histometric assessments. IL-1beta in these extracted specimens was measured with an enzyme-linked immunosorbent assay (ELISA) technique. Pathogenic roles that IL-1beta plays in gingival inflammation and pathologic tissue changes in tissue sections were analyzed statistically. Results: The overall total tissue IL-1beta, tissue concentration of IL-1beta, and percentage of inflammatory cell infiltration (PICI) determined from diseased gingivae were obviously higher than those of controls from both healthy sites of periodontitis and non-periodontitis subjects. With increasing gingival index (GI), plaque index (P1I), and probing depth (PD), there was a marked elevation in total tissue IL-1beta. Total tissue IL-1beta was significantly correlated with GI, P1I, the PICI, and tissue alterations. Polymorphonuclear leukocytes ( PMNs) and monocyte-macrophage cells seemed to predominate in heavily infiltrated areas of diseased gingiva . These cell types were confirmed by immunocytochemical localization with either monoclonal mouse antihuman neutrophil elastase antibody or monoclonal mouse antihuman macrophage (CD 68) antibody, respectively. Total tissue IL-1 beta and the PICI were also elevated in diseased gingivae near deeper PD, while neither total IL-1beta nor tissue concentration was statistically correlated with PD. Thus, correlation analysis indicates that IL-1beta level in inflamed periodontal tissues correlates highly with clinical parameters (GI and P1I) and PICI (the degree of inflammation). Conclusions: These observations suggest that IL-1beta plays a significant role in the pathogenic mechanisms of periodontal tissue destruction, and that measurement of tissue IL-1beta would be a valuable aid and useful for diagnostic markers of periodontal diseases