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Effect of interferon alpha-2b on porcine mesenchymal stem cells
Oral Abstract Session 3: TMJ/Reconstruction/Pathology/Nerve Repair/Wound Repair/Miscellaneous
Effect of Interferon Alpha-2b on Porcine Mesenchymal Stem Cells Haru Abukawa, DDS, PhD, Department of OMS, Mass General Hospital, 55 Fruit Street, WRN 1201, Boston, MA 02114 (Kaban LB; Williams WB; Terada S; Vacanti JP; Troulis MJ) Purpose: In patients with aggressive giant cell tumors of the jaws, treated by curettage and adjuvant interferon, resultant defects have exhibited rapid and exuberant bone formation. The relationship between this regenerative phenomenon, the nature of the angiogenic tumor and interferon treatment is not understood. There are 4 potential explanations: 1) interferon alpha promotes differentiation of mesenchymal stem cells (MSCs) into osteoblasts; 2) interferon alpha stimulates osteoblast proliferation and/or metabolic activity; 3) interferon alpha suppresses osteoclasts (bone resorption) and upsets the homeostasis between bone formation and resorption; or 4) interferon alpha affects tumor cells in such a way as to release some osteogenic growth factor. We hypothesize that interferon promotes bone formation by enhancing mesenchymal stem cell (MSC) differentiation into osteoblast and by stimulating osteoblast activity. This is a preliminary study to determine the effects of interferon alpha on MSCs in culture. Materials and Methods: Bone marrow was harvested from Yucatan minipigs and MSCs were isolated and expanded. Three groups of cells were cultured: 1) negative control (MSCs alone); 2) positive control (MSCs ⫹ standard osteogenic supplements); and 3) experimental (MSCs ⫹ interferon). Cultures were evaluated by DNA analysis for cell proliferation, and by quantitative and qualitative alkaline phosphatase production for osteoblast differentiation. Results: Baseline proliferation rate was established in the negative control group, ie, pMSCs in standard medium, and was consistent with published reports. The experimental group exhibited a slower but constant proliferation rate during the experimental period as compared to both control groups. Cells under experimental conditions exhibited larger size, no clumping, and no layering effect. The peak ALP activity was greater in interferon alpha 2b treated groups (24.8 to 33.6 nmol pNP/min/10 million cells) (day 28 to 35) when compared to negative control (22.7 nmol pNP/min/10 million cells) (day 14), but less than the positive controls, the OS group, 35.2 nmol pNP/min/10 million cells (day 14). Conclusion: The results indicate that interferon may act to differentiate MSCs into osteoblasts. The MSCs were altered in cell shape, behavior and increasing the production of alkaline phosphatase. These results suggest that rapid bone formation in patients treated with interferon alpha may be attributable to an effect of this drug on the local bone forming cells or tumor cells. 56
References Kaban LB, Troulis MJ, Ebb D, et al: Antiangiogenic therapy with interferon alpha for giant cell lesions of the jaws. J Oral Maxillofac Surg 60:1103, 2002 Bruder SP, Jaiswal N, et al: Growth kinetics, self-renewal, and the osteogenic potential of purified human mesenchymal stem cells during extensive subcultivation and following cryopreservation. J Cell Biochem 64:278, 1997
Funding Source: Hanson Foundation.
Resterilization of Single-Use Devices Used in Oral and Maxillofacial Surgery Nicholas J.V. Hogg, DDS, MSc, Department of OMS, Dalhousie University, 5981 University Avenue, Halifax, Nova Scotia B3H 3J5 Canada (Morrison AD) Introduction: Resterilization of instruments used on one patient for reuse on another has been common practice in oral and maxillofacial surgery. In the past decade, there has been promotion of single-use devices (SUDs) in many surgical specialties as a strategy to prevent the transmission of blood and tissue borne pathogens from patient to patient. This practice has also been influenced by some high profile legal cases that have brought the issue of SUDs to the attention of the media and the public. However, the use of disposable instruments does not come without a significant cost to the health care system. Some instruments like bone drills and saws used in oral and maxillofacial and orthopedic procedures are Class I instruments as defined by the FDA and have the potential to be reused if sterility can be guaranteed. Purpose: This study investigated the potential of reusing instruments that are used in the operating room during oral and maxillofacial surgical procedures. Methods: Instruments (bone drills, burs, and saws) used in the operating room were collected over a period of several months. The experiment consisted of 3 groups. The control group was comprised of instruments that were taken directly from the mouth and then placed in a culture medium selected to grow aerobic bacteria. The second group was composed of instruments that were sterilized under heat (132°C) and pressure (30 psi) for 20 minutes without being scrubbed. In the third group, instruments were soaked in antibacterial solution containing proteinases for 2 minutes, scrubbed, and then sterilized in the same fashion. All samples (n ⫽ 240) were then incubated at 37°C and monitored daily for a total of 72 hours. Results: A chi-squared test showed a significant difference between the 3 different test groups (P ⬍ .05). Almost all the control samples showed evidence of bacterial growth in the first 24 hours, and all had growth within the 72-hour observation period. Approximately 30% of instruments in the second group that had been AAOMS • 2003
Effect of Interferon Alpha-2b on Porcine Mesenchymal Stem Cells Haru Abukawa, DDS, PhD, Department of OMS, Mass General Hospital, 55 Fruit Street, WRN 1201, Boston, MA 02114 (Kaban LB; Williams WB; Terada S; Vacanti JP; Troulis MJ) Purpose: In patients with aggressive giant cell tumors of the jaws, treated by curettage and adjuvant interferon, resultant defects have exhibited rapid and exuberant bone formation. The relationship between this regenerative phenomenon, the nature of the angiogenic tumor and interferon treatment is not understood. There are 4 potential explanations: 1) interferon alpha promotes differentiation of mesenchymal stem cells (MSCs) into osteoblasts; 2) interferon alpha stimulates osteoblast proliferation and/or metabolic activity; 3) interferon alpha suppresses osteoclasts (bone resorption) and upsets the homeostasis between bone formation and resorption; or 4) interferon alpha affects tumor cells in such a way as to release some osteogenic growth factor. We hypothesize that interferon promotes bone formation by enhancing mesenchymal stem cell (MSC) differentiation into osteoblast and by stimulating osteoblast activity. This is a preliminary study to determine the effects of interferon alpha on MSCs in culture. Materials and Methods: Bone marrow was harvested from Yucatan minipigs and MSCs were isolated and expanded. Three groups of cells were cultured: 1) negative control (MSCs alone); 2) positive control (MSCs ⫹ standard osteogenic supplements); and 3) experimental (MSCs ⫹ interferon). Cultures were evaluated by DNA analysis for cell proliferation, and by quantitative and qualitative alkaline phosphatase production for osteoblast differentiation. Results: Baseline proliferation rate was established in the negative control group, ie, pMSCs in standard medium, and was consistent with published reports. The experimental group exhibited a slower but constant proliferation rate during the experimental period as compared to both control groups. Cells under experimental conditions exhibited larger size, no clumping, and no layering effect. The peak ALP activity was greater in interferon alpha 2b treated groups (24.8 to 33.6 nmol pNP/min/10 million cells) (day 28 to 35) when compared to negative control (22.7 nmol pNP/min/10 million cells) (day 14), but less than the positive controls, the OS group, 35.2 nmol pNP/min/10 million cells (day 14). Conclusion: The results indicate that interferon may act to differentiate MSCs into osteoblasts. The MSCs were altered in cell shape, behavior and increasing the production of alkaline phosphatase. These results suggest that rapid bone formation in patients treated with interferon alpha may be attributable to an effect of this drug on the local bone forming cells or tumor cells. 56
References Kaban LB, Troulis MJ, Ebb D, et al: Antiangiogenic therapy with interferon alpha for giant cell lesions of the jaws. J Oral Maxillofac Surg 60:1103, 2002 Bruder SP, Jaiswal N, et al: Growth kinetics, self-renewal, and the osteogenic potential of purified human mesenchymal stem cells during extensive subcultivation and following cryopreservation. J Cell Biochem 64:278, 1997
Funding Source: Hanson Foundation.
Resterilization of Single-Use Devices Used in Oral and Maxillofacial Surgery Nicholas J.V. Hogg, DDS, MSc, Department of OMS, Dalhousie University, 5981 University Avenue, Halifax, Nova Scotia B3H 3J5 Canada (Morrison AD) Introduction: Resterilization of instruments used on one patient for reuse on another has been common practice in oral and maxillofacial surgery. In the past decade, there has been promotion of single-use devices (SUDs) in many surgical specialties as a strategy to prevent the transmission of blood and tissue borne pathogens from patient to patient. This practice has also been influenced by some high profile legal cases that have brought the issue of SUDs to the attention of the media and the public. However, the use of disposable instruments does not come without a significant cost to the health care system. Some instruments like bone drills and saws used in oral and maxillofacial and orthopedic procedures are Class I instruments as defined by the FDA and have the potential to be reused if sterility can be guaranteed. Purpose: This study investigated the potential of reusing instruments that are used in the operating room during oral and maxillofacial surgical procedures. Methods: Instruments (bone drills, burs, and saws) used in the operating room were collected over a period of several months. The experiment consisted of 3 groups. The control group was comprised of instruments that were taken directly from the mouth and then placed in a culture medium selected to grow aerobic bacteria. The second group was composed of instruments that were sterilized under heat (132°C) and pressure (30 psi) for 20 minutes without being scrubbed. In the third group, instruments were soaked in antibacterial solution containing proteinases for 2 minutes, scrubbed, and then sterilized in the same fashion. All samples (n ⫽ 240) were then incubated at 37°C and monitored daily for a total of 72 hours. Results: A chi-squared test showed a significant difference between the 3 different test groups (P ⬍ .05). Almost all the control samples showed evidence of bacterial growth in the first 24 hours, and all had growth within the 72-hour observation period. Approximately 30% of instruments in the second group that had been AAOMS • 2003