The glycosylated hemoglobin assay for diabetes: its value to the periodontist. Two case reports.

The glycosylated hemoglobin assay is a relatively new test used in the diagnosis and monitoring of the diabetic patient. This assay should be of interest to the periodontist as it offers important advantages over traditional blood glucose testing methods. Most importantly, it gives an indication of the blood glucose level over an extended period of time (30 to 90 days), whereas traditional assays only indicate the glucose level at one point in time. Additionally, there is no requirement for fasting prior to testing. Two case reports are presented to illustrate how the glycosylated hemoglobin assay can be utilized by the periodontist.

Initial characterization of cells derived from human periodontia.

The studies presented in this report describe an initial characterization of cell types derived from explants of human periodontia. Cell cultures were established from human periodontal ligament (PL4, PL7), gingival tissue (GF2), and alveolar bone (BP1) by means of explant techniques and monolayer culture. Cells were studied at passage numbers 2-4 and were characterized on the basis of morphological, biochemical, and proliferative parameters. Subconfluent cells did not have distinct morphologies useful in distinguishing them from one another. At confluence, PL4 and BP1 cells formed multilayered cultures of randomly oriented cells, while PL7 and GF2 cells grew in a monolayer of parallel cells. Biochemically, PL4 and BP1 cells exhibited characteristics consistent with an osteoblast-like phenotype. These included a significant increase in PTH-stimulated cyclic AMP and high basal levels of alkaline phosphatase activity, which were decreased on exposure to PTH and increased after stimulation by 1.25 dihydroxyvitamin D3. In contrast, PL7 and GF2 cells exhibited basal alkaline phosphatase levels that were low, and cyclic AMP levels were not modulated by PTH stimulation. Cell populations PL7 and GF2 did not proliferate in culture medium supplemented with 3% platelet-poor plasma. After the addition of platelet-derived growth factor (PDGF) to this medium, the proliferation of these cell populations was equal to that in media supplemented with 10% fetal bovine serum. In contrast, PL4 and BP1 cells did proliferate in culture medium supplemented with 3% platelet-poor plasma. The addition of PDGF to the medium resulted in only a moderate increase in the proliferation of cell populations PL4 and BP1.(ABSTRACT TRUNCATED AT 250 WORDS)

Study of the growth factor requirements of human bone-derived cells: a comparison with human fibroblasts.

Recent techniques have been devised for the culture of bone cells derived from human bone explants. These cells, which are thought to represent several stages in the osteoblast lineage, respond to PTH with an increase in cyclic AMP content, and have high basal alkaline phosphatase activity which is increased on exposure to 1,25-dihydroxyvitamin D3 and decreased by PTH. Such characteristics distinguish these cells from fibroblasts. In this study, we demonstrate that human bone-derived cells also differ from fibroblasts in their growth characteristics. Bone-derived cells proliferated in basal medium supplemented with platelet-poor plasma. The rate of proliferation was enhanced by additional supplementation with platelet-derived growth factor (PDGF), and further increased when a combination of growth factors was added (PDGF, TGF-beta and EGF). In contrast, fibroblasts did not proliferate in basal medium supplemented with platelet-poor plasma and the addition of PDGF alone stimulated fibroblast proliferation to the same extent as 10% fetal bovine serum. Supplementation with other growth factors did not further enhance the response of fibroblasts to PDGF. These results emphasize the differences in proliferative responses between human bone-derived cells and human fibroblasts, and indicate that the factors responsible for osseous regeneration in vivo may differ from those factors which regulate repair of soft tissue wounds.