Objective: Recently, cultured myoblast transplantation has been extensively studied as a gene complementation approach in such genetic diseases as Duchenne muscular dystrophy (DMD). In the present work we investigated the stimulating effects of the growth factors, such as basic fibroblast growth factor (bFGF), leukemia inhibitory factor (LIF) and interleukin-1 (IL-1), on growth rate and differentiation of myoblast.

Method: Human myoblasts were cultured from biopsy and treated in vitro with various concentration of bFGF, LIF and IL-1. In serum-free defined medium the following observation were made to evaluate differentiation.

Results: bFGF and LIF except IL-1 were found to have stimulating effect of myoblast proliferation comparing to control group (p＜0.05), yet there were no statistically significant differences among each growth factors (p＞0.05). The most significant growth stimulation of myoblasts in culture was achieved by adding 3.0 ng/ml of bFGF, producing a stimulation effect up to 2.01-fold. All myoblasts treated with growth factors differentiated into myotube.

Conclusion: Our findings indicate that bFGF and LIF stimulate the proliferation of myoblast, which may result in an effective way in producing large numbers of myoblasts for clinical myoblast transplantation in DMD patients. (J Korean Acad Rehab Med 2002; 26: 426-431)

Objective: The purpose of this study was to evaluate the effects of the prolotherapy on the healing of the tendon tissue and the proliferation of fibroblasts in the injured Achilles tendons.

Method: The tendons of twenty eight Sprague-Dawley rats were transected at 2 mm above the calcaneal insertion in the right Achilles tendon and sutured. Then they were allocated randomly into two groups: prolotherapy group and control group. We injected 20% dextrose 0.1 ml on injured tendon area of prolotherapy group immediately after transection. After 2 and 4 weeks, the diameters of tendons were measured on both the injured and uninjured tendon. The number of fibroblasts and the ratio of fibroblast to fibrocyte on the injured tendon tissues were measured by the image analyzer.

Results: The diameters of the injured tendons of the prolotherapy group were not significantly different with that of the control group. However, the number of fibroblasts and the ratio of fibroblast to fibrocyte in the prolotherapy group showed significantly larger and more increased than the control group (p＜0.05).

Conclusion: This result showed the additional regeneration effect of the prolotherapy on the healing of the injured tendon tissue. Therefore, the prolotherapy would be an effective treatment on the tendon injury. (J Korean Acad Rehab Med 2002; 26: 332-336)

Objective: The phenomenon of fibroblast overgrowth is one of the major problems encountered during long-term culture such as myoblast culture. The first goal of the study is to determine the effects of proline analogue and cytosine arabinoside to reduce fibroblasts in myoblast culture. The second goal is to investigate whether the chemicals influence the growth and differentiation of myoblast.

Method: Muscle tissues were obtained from legs of healthy men, and then fibroblasts and myoblasts were isolated and cultured. Those mixed cells were divided into three groups; control group, proline analogue (cis-hydroxyproline) treated group and cytosine arabinoside (araC) treated group. We evaluated the effectiveness of cis-hydroxyproline and araC on selective removal of fibroblasts in culture. We have also determined if cis-hydroxyproline and araC could alter differentiation of myoblast in each group.

Results: The treatment with araC was effective to eliminate fibroblasts comparing to the control group (p＜0.05) while there was no statistically significant difference between proline analogue and control group (p＞0.05). Myoblasts of all three groups were differentiated into myotube.

Conclusion: Using araC, we could reduce a number of fibroblasts in myoblast culture where contamination and subsequent overgrowth with fibroblasts remained a problem.

Objective: Ultrasound has been therapeutically applied for pain control in rheumatoid arthritis although little physiologic effects of sonication on rheumatoid tissue were known. This investigation was conducted to determine the effects of sonication on the cell proliferation and matrix metalloproteinase (MMP) production of cultured fibroblast like synoviocytes (FLS) derived from synovial tissues of rheumatoid arthritis.

Method: Pulsed ultrasound (1.0 MH_Z, 20 msec on, 80 msec off) with varying intensities (0, 0.1, 0.25, 0.5, 0.75, 1.0 W/cm²) was applied to experimental cell groups growing as monolayers in culture plates for varying durations (0, 30, 90, 180 seconds) in the presence and absence of interleukin-1β (IL-1β).

Results: There were no significant differences in thymidine incorporation between 0, 30, 90 and 180 second sonication groups with 0.5 W/cm² after 1 day and 2 days. There were no significant differences in thymidine incorporation between 0, 0.1, 0.25, 0.5, 0.75, 1.0 W/cm² sonication groups 1 day and 2 days after 90 second sonication. There were significant increase in MMP-1 (p=0.025) and MMP-3 production (p=0.000) of FLS after sonication in the absence of IL-1β but there were no significant differences in MMP-1 and MMP-3 production in the presence of IL-1β. And MMP-1 and MMP-3 production were increased significantly in the presence of IL-1β but not than in the absence of IL-1β.

Conclusion: While comparisons made between a limited number of FLS cell lines must be open to question, the overall consistency of the findings suggest sonication with nonthermal effect is not the contraindication in rheumatoid arthritis treatment but further study is needed in vivo in animal and in clinical studies.

Objective: To study the effect of pregnancy on knee joint contracture in the rat, because the laxity of peripheral joint increases during pregnacy.

Method: We evaluated the difference of contracture between the pregnant and non-pregnant female rats after 3 week of knee immobilization using a wire. The femorotibial angle at immobilization status was 30^o. After immobilization, the femorotibial angle were measured using X-ray after removal of wire at 50 g and 100 g weighted state on the tibia. To study the change of fibroblast in immobilized knee joint ligament, immunohistochemical staining for actin was performed using α-smooth muscle actin antibody (DAKO, Denmark).

Results: The femorotibial angles were 116.7⁑9.2^o and 97.3⁑18.0^o after wire removal, in the immobilized pregnant and nonpregnant rats respectively. The femorotibial angles at 50 g and 100 g weighted state were 136.8⁑7.2^o and 144.7⁑3.8^o, respectively in the immobilized pregnant rats and 129.4⁑12.7^o and 136.3⁑8.9^o in the immobilized non-pregnant rats. The angles of pregnant group were significantly larger than those of non-pregnant group (p＜0.05). In immobilized pregnant and non-pregnant rats, the α-smooth muscle actin was moderately expressed in fibroblast of anterior and posterior cruciate ligaments of the knee by immunohistochemistry, while there was no expression of α-smooth muscle actin in fibroblast of the ligaments in the non-immobilized knee.

Conclusion: Joint contracture develops to a lesser degree in pregnant rats than in non-pregnant rats and α-smooth muscle actin is expressed in fibroblast of contractured knee ligaments.