ABSTRACT
OBJECTIVES: The purpose of this study is to identify whether the change of pH affects the proliferation and the differentiation of human bone marrow stem cells (hBMSCs) and what mechanism is underlied. METHODS: To achieve objective of this study, hBMSCs were cultivated in the conditioned media adjusted to potential of hydrogen (pH) ranging from 6.4 to 8.0 using addition of hydrochloric acid (HCl) and sodium hydroxide (NaOH). The ratio of proliferation of hBMSCs according to the change of pH was measured for 24 h, 48 h, and 72 h using water-soluble tetrazolium salt (WST)-8 method. To elucidate the mechanism involved, hBMSCs was subjected to blocking extracellular signal-regulated kinases (ERK) and calcium sensing receptor (CaSR) activation. The Osteogenic-related genes and alkaline phosphatase (ALP) activity were tested under the conditioned media. RESULTS: The proliferation of hBMSCs was promoted under extracellular alkali conditions (pH 7.6~8.0) via CaSR/ERK pathway. On the other hand, the differentiation was inhibited/delayed via decreased ALP activity besides gene expression at pH 8.0. CONCLUSION: Extracellular alkali or acidic surrounding according to pH alteration can play a crucial role in hBMSC behavior including the proliferation and the differentiation.
Subject(s)
Humans , Alkalies , Alkaline Phosphatase , Bone Marrow , Bone Marrow Cells , Cell Differentiation , Cell Proliferation , Culture Media, Conditioned , Extracellular Signal-Regulated MAP Kinases , Gene Expression , Hand , Hydrochloric Acid , Hydrogen , Hydrogen-Ion Concentration , Hydroxides , Receptors, Calcium-Sensing , Sodium Hydroxide , Stem CellsABSTRACT
OBJECTIVES: The purpose of this study is to identify whether the change of pH affects the proliferation and the differentiation of human bone marrow stem cells (hBMSCs) and what mechanism is underlied. METHODS: To achieve objective of this study, hBMSCs were cultivated in the conditioned media adjusted to potential of hydrogen (pH) ranging from 6.4 to 8.0 using addition of hydrochloric acid (HCl) and sodium hydroxide (NaOH). The ratio of proliferation of hBMSCs according to the change of pH was measured for 24 h, 48 h, and 72 h using water-soluble tetrazolium salt (WST)-8 method. To elucidate the mechanism involved, hBMSCs was subjected to blocking extracellular signal-regulated kinases (ERK) and calcium sensing receptor (CaSR) activation. The Osteogenic-related genes and alkaline phosphatase (ALP) activity were tested under the conditioned media. RESULTS: The proliferation of hBMSCs was promoted under extracellular alkali conditions (pH 7.6~8.0) via CaSR/ERK pathway. On the other hand, the differentiation was inhibited/delayed via decreased ALP activity besides gene expression at pH 8.0. CONCLUSION: Extracellular alkali or acidic surrounding according to pH alteration can play a crucial role in hBMSC behavior including the proliferation and the differentiation.
Subject(s)
Humans , Alkalies , Alkaline Phosphatase , Bone Marrow , Bone Marrow Cells , Cell Differentiation , Cell Proliferation , Culture Media, Conditioned , Extracellular Signal-Regulated MAP Kinases , Gene Expression , Hand , Hydrochloric Acid , Hydrogen , Hydrogen-Ion Concentration , Hydroxides , Receptors, Calcium-Sensing , Sodium Hydroxide , Stem CellsABSTRACT
Purpose: To prospectively evaluate the survival rate, follow-up rate, clinical and radiographic results of NexGen(R) total knee replacement arthroplasty (TKRA). Materials and Methods: Between June 1998 and March 2002, 434 knees in 278 patients after TKRA performed by a single-surgeon using the same implant were evaluated prospectively. The preoperative diagnosis was primary osteoarthritis in 399 knees, osteonecrosis in 17 knees, rheumatoid arthritis in 12 knees and post-traumatic arthritis in 6 knees. Data collection, physical examination and radiographic evaluation were carried out at postoperative 1, 2, 3 and 5 years. A telephone survey was carried out for the patients who could not visit the outpatient clinic, and the mean follow-up duration was 4.3 years (3-7 years). The follow-up rate and survival rate was analyzed using the Kaplan-Meier method with the reimplantation cases being counted as a failure. The clinical results were evaluated by the Knee Society Score, and the range of motion and status of the implants were assessed by a radiographic evaluation. Results: The total follow up rate was 91.0% (395/434). The survival rate was 98.3% at 5 years after surgery and the survival rate excluding the infection cases was 99.0% 5 years after surgery. The Knee Society Total Score improved to 96.8 in the cruciate retaining (CR) type and to 95.2 in the Legacy posterior stabilized (LPS) type. The Knee Society Function Score improved to 82.6 in the CR type and to 73.8 in the LPS type on the final follow up. The average preoperative further flexion was 122.6, which improved to 125.4. The radiographic evaluation revealed 6 cases (1.5%) of osteolysis with reimplantation being performed in 2 cases. Conclusion: In this prospective study, with a high follow-up rate (91.0%), the survival rate of TKRA using the NexGen(R) implant was relatively high and satisfactory in terms of the functional improvement. However, a long-term follow-up evaluation will be needed.