許多的臨床與動物實驗顯示，使用脈衝式低強度超音波（Pulsed Low-Intensity Ultrasound (PLIUS)）能夠促進骨折癒合。而許多的文獻也指出，動物的軟骨細胞（chondrocyte）於體外培養時（in vitro），經由脈衝式低強度超音波刺激後，能促使軟骨細胞產生更多的黏多醣蛋白（proteoglycan）與第二型膠原蛋白（type II collagen）。本研究的目的主要是來探討脈衝式低強度超音波對體外培養的人類軟骨細胞之生物效應。
從6位年齡介於1歲至10歲的多指症病人手術切除的手指關節分離萃取出軟骨細胞，懸浮培養於洋菜膠（agarose）構成的三度空間，三天後實驗組使用脈衝式低強度超音波給予3.6、18、48、72、98 mW/cm2五種不同強度的刺激，每天10分鐘、連續14天，而控制組則不給予脈衝式低強度超音波。
結果發現，體外培養的軟骨細胞經過超音波刺激後，合成黏多醣蛋白的量與控制組相比較，有明顯隨時間增加而增加的促進趨勢。而以ELISA方法定量所試驗的超音波刺激強度中，48 mW/cm2有最強的促進合成黏多醣蛋白反應。同樣的結果也出現在第二型膠原蛋白的合成上，以西方點墨法定量經過強度48 mW/cm2的超音波刺激後的人類軟骨細胞，所生成的第二型膠原蛋白和控制組相比較則增加了48.5+8.0%。然而，超音波刺激人類軟骨細胞後與控制組比較起來，並無明顯的影響細胞的增殖。細胞數目不增加，但細胞外基質產量增加這更加證實超音波有促進人類軟骨細胞分泌細胞外基質的能力。另外，由1歲的病人身上所收集的軟骨細胞，接受超音波刺激後所表現的生物效應更明顯。這些觀察使得PLIUS對體外培養的人類軟骨細胞之生物效應有更加的了解。

Animal and clinical studies have shown an acceleration of bone healing by the application of pulsed low-intensity ultrasound (PLIUS). Several studies have reported that pulsed low-intensity ultrasound increase the synthesis of proteoglycan and type II collagen of cultured animal chondrocytes. The objectives of this study were to exam the bioeffect of pulsed low-intensity ultrasound on in vitro cultured human chondrocytes.
Human chondrocytes were isolated from the amputated polydactyly digit of six different 1 to 10 years patients and cultured in agarose suspension for 3 days before treatment. PLIUS with intensities of 3.6, 18, 48, 72 and 98 mW/cm2was respectively applied to human chondrocytes for a single 10-min per day treatment. A control group was treated without PLIUS.
The results demonstrated that PLIUS-treated human chondrocytes increased the proteoglycan synthesis compared with the control in a time-dependent manner. It is shown that the effect of 48 mW/cm2 is the most potent among a variety of PLIUS intensities tested determined by ELISA method. PLIUS at 48 mW/cm2 also increased type II collagen synthesis by up to 48.5+8.0% of the control determined by western blotting analysis. However, PLIUS has no significant influence on the cell proliferation of human chondrocytes compared with the control. It revealed that the PLIUS can enhance extracellular matrix synthesis. The response to PLIUS of chondrocytes harvested from 1 year old donor was significantly better than that of chondrocytes of 10 years old patient.
These observations may lead to a better understanding of the bioeffect of PLIUS on in vitro cultured human chondrovytes.

目 錄
審定書……………………………………………………………1
目錄……………………………………………………………2-3
中文摘要………………………………………………………4-5
英文摘要…………………………………………………………6
第一章：緒論
1-1關節軟骨簡介…………………………………7-10
1-2關節軟骨的損傷與治療…………………… 11-13
1- 3超音波簡介…………………………………13-19
1-4研究目的……………………………………… 20
第二章：材料與方法
2-1材料……………………………………………21
2-2方法
2-2-1軟骨細胞的分離與培養………………21-22
2-2-2細胞Doubling Time………………………22
2-2-3三度空間懸浮培養……………………22-23
2-2-4脈衝式低強度超音波刺激………………23
2-2-5細胞黏多醣蛋白的ELISA定量…………24
2-2-6細胞第二型膠原蛋白蛋白定量與西方點墨法………………………………………25-26
2-2-7細胞第二型膠原蛋白的ELISA測定…27-28
2-2-8細胞DNA的萃取………………………28-29
2-2-9統計分析………………………………… 29
第三章：結果…………………………………………………30-33
第四章：討論…………………………………………………34-37
圗：……………………………………………………………38-43
參考文獻：……………………………………………………44-55
附圗：…………………………………………………………56-64
附表：…………………………………………………………65-66

Aston JE, Bentley G: Repair of articular surfaces by allografts of articular and growth-plate cartilage. J Bone Joint Surg 1986; 68-B: 29-35.

Askew MJ, Mow VC: The biomechanical function of the collagen ultrastructure of articular cartilage. J Biomech Eng 1978; 100: 105.

Barnett SB, ter Haar GR, Ziskin MC et al.: Current status of research on biophysical effects of ultrasound. Ultrasound Med Biol 1994; 20: 205-18.

Berridge MJ: Inositol trisphosphate and calcium signaling. Nature (London) 1993; 361: 315-25.

Breinan HA, Minas T, Barone L, Tubo R, Hsu HP, Shortkroff S, Nehrer S, Sledge CB, Spector M: Histological evaluation of the course of healing of canine articular cartilage defects treated with cultured autologous chondrocytes. Tissue Eng 1998; 4: 101-14.

Brittberg M, Lindahl A, Nilsson A, Ohlsson C: Cellular aspects on treatment of cartilage injuries. Agents Actions Supply 1993; 39: 237-41.

Brittberg M, Lindahl A, Nilsson A, Ohlsson C, Isaksson O, Peterson L: Treatment of deep cartilage defects in the knee with autologous chondrocyte transplantation. N Eng J Med 1994; 331: 889-95.

Buckwalter JA, Rosenberg LC: Electron microscopic studies of cartilage proteoglycans: direct evidence for the variable length of the chondroitin sulfate rich region of the proteoglycan subunit core protein. J Biol Chem 1982; 257: 9830-39.

Buckwalter JA, Hunziker E, Rosenberg L et al: Articular Cartilage: Composition and Sturcture. In Woo SL-Y, Buckwalter J (eds): Injury and Repair of the Musculoskeletal Soft Tissues. Park Ridge, IL, American Academy of Orthopaedic Surgeons 1988; 405-25.

Buckwalter JA, Goldberg V, Woo SL-Y: Musculoskeletal Soft-Tissue Aging: Impact on Mobility. American Academy of Orthopaedic Surgeons, Rosemont, Illinois 1993a.

Buckwalter JA, Hunziker EB: Articular cartilage biology and morphology. In Mow VC, Ratcliffe A (eds): Structure and Function of Articular Cartilage. Boca Raton, FL, CRC Press, 1993b.

Buckwalter JA, Woo SL-Y, Goldberg VM, Hadley EC, Booth F, Oegema TR, Eyre DR: Soft tissue aging and musculoskeletal function. J Bone Joint Surg 1993c; 75A: 1533-48.

Buckwalter JA, Roughley PJ, Rosenberg LC: Age-related changes in cartilage proteoglycans: quantitative electron microscopic studies. Micros Res Tech 1994; 28: 398-408.

Buckwalter JA: Articular cartilage: injuries and potential for healing. J Orthop Sports Phys Ther 1998a; 28: 192-202.

Buckwalter JA, Mankin HJ: Articular cartilage: degeneration and osteoarthritis, repair, regeneration and transplantation. AAOS Inst Course Lect 1998b; 47: 487-504.

Buckwalter JA, Martin JA, Mankin HJ: Synovial joint degeneration and the syndrome of osteoarthritis. Ciba Geigy Instructional Course Lectures, 2000; 49: 481-9.

Buckwalter JA, Mow VC, Hunziker EB: Concepts of Cartilage Repair in Osteoarthritis R In: Moskowitz VM, Goldberg D, Howell R, Altman, Buckwalter JA (eds): Osteoarthritis: Diagnosis and Medical/Surgical Management, Saunders, Philadelphia, 3rd edition, 2001a; 101-114.

Buckwalter JA, Stanish WD, Rosier RN, Schenck RC, Dennis DA, Coutts RD: The increasing need for nonoperative treatment of osteoarthritis. Clin Ortho Rel Res 2001b; 385: 36-45.

Campbell IK, Piccoli DS, Butler DM, Singleton DK, Hamilton JA: Recombinant human interleukin-1 stimulates human articular cartilage to undergo resorption and human chondrocytes to produce both tissue and urokinase-type plasminogen activator. Biochim Biophys Acta 1988; 967(2): 183-94.

Caplan AI, Elyaderani M, Mochizuki Y, Wakitani S, Goldberg VM: Principles of cartilage repair and regeneration. Clin Orthop Rel Res 1997; 342: 254-69.

Carstensen EL: Biological effects of acoustic cavitation. First Symposium on Safety and Standardisation of Ultrasound in Obstetrics. Ultrasound Med Biol 1986; 12: 703-4.

Chapman IV, MacNally NA, Tucker S: Ultrasound-induced changes in rates of influx and efflux of potassium ions in rat thymocytes in vitro. Ultrasound Med Biol 1979; 6: 47-58.

Cook SD, Salkeld SL, Popich-Patron LS et al.: Improved cartilage repair after treatment with low-intensity pulsed ultrasound. Clin Orthop 2001; 391S: S231-S243.

DeGroot J, Verzijl N, Bank RA, Lafeber FP, Bijlsma JW, TeKoppele JM: Age-related decrease in proteoglycan synthesis of human articular chondrocytes: the role of nonenzymic glycation. Arth Rheum 1999; 42: 1003-9.

Dinno MA, Dyson M, Young SR, Mortimer AJ, Hart J, Crum LA: The significance of membrane changes in the safe and effective use of therapeutic and diagnostic ultrasound. Phys. Med Biol 1989; 34: 1543-52.

Drewniak JL, Cames KI, Dunn F: In vitro ultrasonic heating of fetal bone. J Acoust Sot Am 1989; 86: 1254-58.

Dyson M: Therapeutic applications of ultrasound. In: Nyborg WL, Ziskin MC (eds): Biological effects of ultrasound New York. Churchill Livingstone, 1985; 121-33.

Dyson M: Mechanisms involved in therapeutic ultrasound. Physiotherapy (UK) 1987; 73: 116-20.

Ebisawa K, Hata K, Okada K, Kimata K, Ueda M, Torii S, Watanabe H: Ultrasound enhances transforming growth factor beta-mediated chondrocyte differentiation of human mesenchymal stem cells. Tissue Eng 2004; 10(5-6): 921-29.

Gillogly SD, Voight M, Blackburn T: Treatment of articular cartilage defects of the knee with autologous chondrocyte implantation. J Orthop Sports Phys Ther 1998; 28: 241-51.

Grodzinsky AJ: Mechanical and electrical properties and their relevance to the physiological processes. In: Marousas A, Kuettner K (eds): Methods in Cartilage Research, London, Academic Press, 1990; 275-311.

Gunja-Smith Z, Nagase H, Woessner JF Jr: Purification of the neutral proteoglycan-degrading metalloproteinase from human articular cartilage tissue and its identification as stromelysin matrix metalloproteinase-3. Biochem J 1989; 258(1): 115-9.

Guo LY, Jowdian GW, MacCallum DK: Culture and growth characteristics of chondrocytes encapsulated in alginate beads. Connect Tissue Res 1989; 19: 277-97.

Hall AC, Urban JP, Gehl KA: The effects of hydrostatic pressure on matrix synthesis in articular cartilage. J Orthop Res 1991 Jan; 9(1): 1-10.

Hardingham TE, Ewins RJ, Muir H: Cartilage proteoglycans. Structure and heterogeneity of the protein core and the effects of specific protein modifications on the binding to hyaluronate. Biochem J 1976; 157(1): 127-43.

Hardingham TE, Beardmore-Gray M, Dunham DG: Protein domain structure of the aggregating proteoglycan from cartilage. Trans Orthop Res Soc 1987; 12: 61.

Hascall VC: Interaction of cartilage proteoglycans with hyaluronic acid. J Supramol Struct 1977; 7(1): 101-20.

Hauselmann HJ, Fernandes RJ, Mok SS, Schmid TM, Block JA, Aydelotte MB, Kuettner KE, Thonar EJ: Phenotypic stability of bovine articular chondrocytes after long-term culture in alginate beads. J Cell Sci 1994; 107 (Pt 1): 17-27.

Hay ED(ed): Cell Biology of the Extracellular Matrix, 2nd edition, New York, Plenum Press; 1991.

Heckman JD, Ryaby JP, McCabe J, Frey JJ, Kilcoyne RF: Acceleration of tibial fracture-healing by non-invasive, low-intensity pulsed ultrasound. J Bone Joint Surg Am 1994; 76(1): 26-34.

Heinegard D, Hascall VC: Aggregation of cartilage proteoglycans. 3. Characteristics of the proteins isolated from trypsin digests of aggregates. J Biol Chem 1974; 249(13): 4250-56.

Heinegard D, Axelsson I: Distribution of keratan sulfate in cartilage proteoglycans. J Biol Chem 1977; 252(6): 1971-79.

Heinegard D, Paulsson M: Structure and metabolism of proteoglycans. In: K.A. Piez, A. H. Reddi. (eds): Extracellular Matrix Biochemistry. New York, Elsevier, 1984; 277-328.

Holmes MA, Rudland JR: Clinical trials of ultrasound treatment in soft tissue injury: A review and critique. Physiother. Theory Pratt 1991; 7: 145-208.

Homminga G, van der Linden T, Terwindt-rouwenhorst E, Drukker J: Repair of articular defects by perichondrial grafts: Experiments in the rabbit. Acta Orthop Scand 1989; 60: 326-9.

Huang M, Ding H, Chai C, Huang Y, Yang R: Effects of sonication on articular cartilage in experimental osteoarthritis. J Rheumatol 1997; 24: 1978-84.

Huiskes R, Ruimerman R, van Lenthe GH, Janssen JD: Effects of mechanical forces on maintenance and adaptation of form in trabecular bone. Nature 2000; 405: 704-6.

Hunter W: On the structure and disease of articulating cartilage. Philos Trans R Soc Lond 1743; 42: 514-21.

Hunziker EB, Rosenberg LC: Repair of partial-thinkness articular cartilage defects. Cell recruitment from the synovium. J Bone Joint Surg 1996; 78A: 721-33.

Hunziker EB: Articular cartilage repair: Are the intrinsic biological constraints undermining this process insuperable? Osteoarthr Cartil 1999; 7: 15-28.

Kaufman JJ, Einhorn TA: Ultrasound assessment of bone. J Bone Miner Res 1993; 8: 517-25.

Kempson GE: The mechanical properties of articular cartilage. In: Sokoloff L (ed): The Mechanical Properties of Articular Cartilage II. Academic Press, New York, 1980; 177-238.

Kempson GE: Relationship between the tensile properties of articular cartilage from the human knee and age. Ann Rheum Dis 1982; 41: 508-11

Kempson GE: Age-related changes in the tensile properties of human articular cartilage: a comparitive study between the femoral head of the hip joint and the talus of the ankle joint. Biochim Biophys Acta 1991; 1075: 223-30.

Kim HK, Moran ME, Salter RB: The potential for regeneration of articular cartilage in defects created by chondral shaving and subchondral abrasion-An experimental investigation in rabbits. J Bone Joint Surg 1991; 73A: 1301-15.

Kitchen S, Partridge C: A review of therapeutic ultrasound. Physiotherapy (UK) 1990; 76593-600.

Kristiansen T, Ryaby B, McCabe J, Frey J, Roe L: Accelerated healing of distal radial fractures with the use of specific, low-intensity ultrasound. J Bone Joint Surg 1997; 79(A): 961-73.

Kuettner KE, Pauli BU, Gall G, Memoli VA, Schenk RK: Synthesis of cartilage matrix by mammalian chondrocytes in-vitro. I. Isolation, culture characteristics and morphology. J Cell Biol 1982; 93: 743-50.

Ma PX, Schloo B, Mooney D, Langer R: Development of biomechanical properties and morphogenesis of in vitro tissue engineered cartilage. J Biomed Mater Res 1995; 29: 1587-95.

Mankin HJ: The reactions of articular cartilage to injury and osteoarthristis (first of two parts). N Engl J Med 1974; 291: 1285-92.

Mankin HJ, Thrasher AZ: Water content and binding in normal and osteoarthritic human cartilage. J Bone Joint Surg Am 1975; 57(1): 76-80.

Mankin HJ: The response of articular cartilage to mechanical injury. J bone Joint surg 1982; 64A: 460-6.

Mankin HJ, Mow V, Buckwalter J, Iannotti J, Ratcliffe A: Form and Function of Articular Cartilage. In Simon S (ed): Orthopedic Basic Secience. Park Ridge, IL, American Academy of Orthopedic Surgeons, 1994: 1-44.

Maroudas A, Bayliss MT, Venn MF: Further studies on the composition of human femoral head cartilage. Ann Rheum Dis 1980; 39(5): 514-23.

Maxwell L: Therapeutic ultrasound: its effects on the cellular and molecular machanisms of inflammation and repair. Physiotherapy (UK) 1992; 78: 421-6.

Maylia E, Nokes LD: The use of ultrasonic in orthopaedics—a review. Technol Health Care 1999; 7: 1-28.

Meachim G: The effect of scarification on articular cartilage in the rabbit. J Bone Joint Surg 1963; 45B: 150-61.

Minas T: The role of cartilage repair techniques, including chondrocyte transplantation, in focal chondral knee damage. AAOS Inst Course Lect 1999; 48: 629-43.

Moed BR, Kim EC, van Holsbeeck M, Schaffler MB, Subramanian S, Bouffard JA, Craig JG: Ultrasound for the early diagnosis of tibial fracture healing after static interlocked nailing without reaming: histologic correlation using a canine model. J Orthop Trauma 1998a; 12: 200-5.

Moed BR, Subramanian S, van Holsbeeck M, Watson JT, Cramer KE, Karges DE, Craig JG, Bouffard JA: Ultrasound for the early diagnosis of tibial fracture healing after static interlocked nailing without reaming: clinical results. J Orthop Trauma 1998b; 12: 206-13.

Mortimer AJ, Dyson M: The effect of therapeutic ultrasound on calcium uptake in fibroblasts. Ultrasound Med Biol 1988; 14: 499-506.

Mow VC, Lai WM, Redler L: Some surface characteristics of articular cartilage. I. A scanning electron microscopy stuffy and a theoretical model for the dynamic interaction of synovial fluid and articular cartilage. J Biomech 1974; 7: 449.

Mow VC, Holmes MH, Lai WM: Fluid transport and mechanical properties of articular cartilage: a review. J Biomech 1984; 17(5): 377-94.

Mow VC, Zhu W, Ratcliffe A: Structure and function of articular cartilage and meniscus. In Mow VC, Hayes WC (eds): Basic Orthopaedic Biomechanics. New York, Raven Press, 1991; 43-198.

Mow VC, Setton LA, Guilak F, Ratcliffe A: Mechanical factors in articular cartilage and their role in osteoarthritis In: Kuettner KE and Goldberg VM (eds) Osteoarthritic Disorders, American Academy of Orthopaedic Surgeons, Rosemont, Illinois, 1995; 147-71.

Muir H: Biochemistry: In M. A. R. Freeman. (ed): Adult Articular Cartilage. 2nd edition. Tunbridge Wells, Pitman Medical, 1979; 145-214.

Muir, H: The chemistry of the ground substance of joint cartilage. In L. Sokoloff. (ed): The Joints and Synovial Fluid. Vol. 2. New York, Academic Press, 1980; 27-94.

Nguyen Q, Murphy G, Roughley PJ, Mort JS: Degradation of proteoglycan aggregate by a cartilage metalloproteinase: Evidence for the involvement of stromelysin in the generation of link protein heterogeneity in situ. Biochem J 1989; 259(1): 61-7.

Nishikori T, Ochi M, Uchio Y, Maniwa S, Kataoka H, Kawasaki K, Katsube K, Kuriwaka M: Effects of low-intensity pulsed ultrasound on proliferation and chondroitin sulfate synthesis of cultured chondrocytes embedded in Atelocollagen gel. J Biomed Mater Res 2002; 59(2): 201-6.

Nyborg WL, Ziskin MC: Biological effects of ultrasound (vol. 16): Clinics in diagnostic ultrasound. New York: Churchill Livingstone, 1985.

O'Driscoll SW: The healing and regeneration of articular cartilage. J Bone Jt Surg 1998; 80-A: 1795-812.

Paget J: Healing of injuries in various tissues. Lect Surg Pathol 1853; 1: 262-70.

Palmoski MJ, Brandt KD: Running inhibits the reversal of atrophic changes in canine knee cartilage after removal of a leg cast. Arthritis Rheum 1981; 24(11): 1329-37.

Palmoski MJ, Brandt KD: Effects of static and cyclic compressive loading on articular cartilage plugs in vitro. Arthritis Rheum 1984; 27(6): 675-81.

Parkkinen JJ, Lammi MJ, Helminen HJ, Tammi M: Local stimulation of proteoglycan synthesis in articular cartilage explants by dynamic compression in vitro. J Orthop Res 1992; 10(5): 610-20.

Parvizi J, Wu C, Lewallen DG, Greenleaf JF, Bolander ME: Low intensity ultrasound stimulates proteoglycan synthesis in rat chondrocytes by increasing aggrecan gene expression. J Orthop Res 1999; 17: 488-94.

Parvizi J, Parpura V, Greenleaf JF: Calcium signaling is required for ultrasound-stimulated aggrecan synthesis by rat chondrocytes. J Orthop Res 2002; 20(1): 51-7.

Perkins SJ, Miller A, Hardingham TE, Muir H: Physical properties of the hyaluronate binding region of proteoglycan from pig laryngeal cartilage. J Mol Biol 1981; 150(1): 69-95.

Praemer A, Furner S and Rice DP: Musculoskeletal Conditions in the United States. American Academy of Orthopaedic Surgeons, Rosemont Illinois, 1999.

Rodan GA, Mensi T, Harvey A: A quantitative method for the application of compressive forces to bone in tissue culture. Calcif Tissue Res 1975; 18(2): 125-31.

Roth V, Mow VC: The intrinsic tensile behavior of the matrix of bovine articular cartilage and its variation with age. J Bone Joint Surg 1980; 62A: 1102-17.

Sachs F: Mechanical transduction in biological systems. CRC Crit. Rev Biomed Eng1988; 16: 141-69.

Sandy JD, Brown HL, Lowther DA: Degradation of proteoglycan in articular cartilage. Biochim Biophys Acta 1978; 543(4): 536-44.

Schneiderman R, Keret D, Maroudas A: Effects of mechanical and osmotic pressure on the rate of glycosaminoglycan synthesis in the human adult femoral head cartilage: an in vitro study. J Orthop Res 1986; 4(4): 393-408.

Shapiro F, Koide S, Glimcher MJ: Cell origin and differentiation in the repair of full-thickness defects of articular cartilage. J Bone Jt Surg 1993; 75-A: 532-53.

St John Brown R: How safe is diagnostic ultrasonography? J Can Med Assoc 1984; 131: 307-11.

Stockwell RA: Biology of Cartilage Cells. Cambridge, UK, Cambridge University Press, 1979; 7-29.

Stockwell RA: Structure and function of the chondrocyte under mechanical loading. In Helminen HJ (ed): Joint Loading: Biology and Health of Articular Structures. Bristol, UK, Wright-Butterworth Scientific, 1992; 26-48.

Thonar EM, Bjornsson S, Kuettner KE: Age-related changes in cartilage proteoglycans In: Kuettner KE, Schleyerbach R, Hascall VC (eds): Articular Cart Biochem. Raven Press, New York, 1986a; 273-87.

Thonar EJ, Buckwalter JA, Kuettner KE: Maturation related differences in the structure and composition of proteoglycans synthesized by chondrocytes from bovine articular cartilage. J Biol Chem 1986b; 261: 2467-74.

Van CM, Christopher SP, Michael AK: Biomechanics of Articular Cartilage. In: Margareta N, Victor HF (eds): Basic Biomechanics of the Musculoskeletal System. Lea & Febiger, Philadelphia, London, 2nd edition, 1989; 31-58.

Verbruggen G, Veys EM, Wieme N, Malfait AM, Gijselbrecht L, Nimmegeers J, et al: The synthesis and immobilisation of cartilage-specific proteoglycan by human chondrocytes in different concentrations of agarose. Clin Exp Rheumatol 1990; 8: 371-8.

Verzijl N, DeGroot J, Oldehinkel E, Bank RA, Thorpe SR, Baynes JW, Bayliss MT, Bijlsma JW, Lafeber FP, TeKoppele JM: Age-related accumulation of maillard reaction products in human articular cartilage collagen. Biochem J 2000; 350: 381-7.

Wakitani S, Goto T, Pineda SJ, Young RG, Mansour JM, Caplan AI, Goldberg VM: Mesenchymal cell-based repair of large, fullthickness defects of articular cartilage. J Bone Jt Surg 1994; 76A: 579-92.

Wakitani S, Goto T, Young RG, Mansour JM, Goldberg VM, Caplan AI: Repair of large full-thickness articular cartilage defects with allograft articular chondrocytes embedded in a collagen gel. Tissue Eng 1998; 4: 429-44.

Wells PN: Surgical applications of ultrasound. In: Nyborg WL, Ziskin MC (eds): Biological effects of ultrasound. New York, Churchill Livingstone, 1985; 157-67.

Wiltink A, Nijweide PJ, Oosterbaan WA, Hekkenberg RT, Helders PJ: Effect of therapeutic ultrasound on endochondral ossification. Ultrasound Med Biol 1995; 21: 121-27.

Wirth CJ, Rudert M: Techniques of cartilage growth enhancement: a review of the literature. Arthroscopy 1996; 12: 300-8.

Wolff J (ed): The law of bone remodeling. Berlin: Hirshwald, German, 1892; 17-35.

Wright MO, Stockwell RA, Nuki G: Response of plasma membrane to applied hydrostatic pressure in chondrocytes and fibroblasts. Connect Tissue Res 1992; 28(1-2): 49-70.

Yamada H, Stephens RW, Nakagawa T, McNicol D: Human articular cartilage contains an inhibitor of plasminogen activator. J Rheumatol 1988; 15(7): 1138-43.

Yang KH, Parvizi J, Wang SJ, Lewallen DG, Kinnick RR, Greenleaf JF, Bolander ME: Exposure to low-intensity ultrasound increases aggrecan gene expression in a rat femur fracture model. J Orthop Res 1996; 14(5): 802-9.

Zaucke F, Dinser R, Maurer P, Paulsson M: Cartilage oligomeric matrix protein (COMP) and IX are sensitive markers for the differentiation state of articular primary chondrocytes. Biochem J 2001; 358: 17-24.

Zhang ZJ, Huckle J, Francomano CA, Spencer RG: The influence of pulsed low-intensity ultrasound on matrix production of chondrocytes at different stages of differentiation: an explant study. Ultrasound Med Biol 2002; 28(11-12): 1547-53.

Zhang ZJ, Huckle J, Francomano CA, Spencer RG: The effects of pulsed low-intensity ultrasound on chondrocyte viability, proliferation, gene expression and matrix production. Ultrasound Med Biol 2003; 29(11): 1645-51.

Ziskin MC: Applications of ultrasound in medicine—comparison with other modalities. In: Rapacholi MH, Grandolfo M, Rindi A (eds): Ultrasound: medical applications, biological effects, and hazard potential. New York: Plenum Press; 1987; 49-59.