Biomedical subjects

Rikuo Shinomiya

Publications and source records attributed to Rikuo Shinomiya.

5 recordsLinked to original sources

PubMed2006

Temporal change of joint position sense after posterior cruciate ligament reconstruction using multi-stranded hamstring tendons.

A total of 29 patients who had undergone posterior cruciate ligament (PCL) reconstruction using multi-stranded hamstring tendons were prospectively followed-up for joint stability and proprioceptive function at a minimum of 24 months after surgery. We measured temporal changes of the posterior laxity by stress radiography and the KT-2000 arthrometer, and we also measured joint position sense for an average of 42 months (range 24-78 months). In terms of results, improvement of joint stability was observed postoperatively and maintained over 2 years after PCL reconstruction, although posterior stability in the reconstructed knee was not identical to the contralateral normal knee. Although joint position sense worsened just after reconstruction, it gradually recovered from 18 months after surgery. However, proprioceptive function after PCL reconstruction did not recover to the same level as in the contralateral normal knee even over 24 months after surgery.

Adolescent↗

PubMed2005

Meniscal regeneration using tissue engineering with a scaffold derived from a rat meniscus and mesenchymal stromal cells derived from rat bone marrow.

The purpose of this study was to regenerate a meniscus using a scaffold from a normal meniscus and mesenchymal stromal cells derived from bone marrow (BM-MSCs). Thirty Sprague-Dawley rat menisci were excised and freeze-thawed three times with liquid nitrogen to kill the original meniscal cells. Bone marrow was aspirated from enhanced green fluorescent protein transgenic Sprague-Dawley rats. BM-MSCs were isolated, cultured for 2 weeks, and 2 x 10(5) cells were then seeded onto the meniscal scaffolds. Using a fluorescent microscope and immunohistochemical staining, repopulation of enhanced green fluorescent protein positive cells was observed in the superficial zone of the scaffold after 1 week of culture, and then in the deep zone after 2 weeks. At 4 weeks, expression of extracellular matrices was detected histologically and expression of mRNA for aggrecan and type X collagen was detected. Stiffness of the cultured tissue, assessed by the indentation stiffness test, had increased significantly after 2 weeks in culture, and approximated the stiffness of a normal meniscus. From this study, we conclude that a scaffold derived from a normal meniscus seeded with BM-MSCs can form a meniscus approximating a normal meniscus.

Animals↗

PubMed2005

Meniscal repair using bone marrow-derived mesenchymal stem cells: experimental study using green fluorescent protein transgenic rats.

Meniscal tears in the avascular zone have very limited potential to heal because of a poor blood supply. Although there have been many attempts to promote the healing potential of the torn meniscus, no established treatments have achieved sufficient meniscal healing. In this study, we evaluated the efficacy of mesenchymal stem cell transplantation as a cell source to promote meniscal healing, using cells from the green fluorescent protein (GFP) transgenic rat and organ culture model. Mesenchymal stem cells from bone marrow were isolated and expanded in monolayer culture. They were embedded in fibrin glue and were transplanted into the meniscal defects of Sprague-Dawley rats. In the control groups, the defects remained untreated, or only fibrin glue without cells was transplanted. The GFP-positive cells enabled us to detect the transplanted cells from recipient cells easily. As a result, transplanted mesenchymal stem cells could survive and proliferate in the meniscal defects in the organ culture model. They also could produce an abundant extracellular matrix stained by toluidine blue around the cells which contributed to meniscal healing in the avascular status. We could detect transplanted GFP cells under a fluorescent microscope until 8 weeks after transplantation. In a clinical situation, mesenchymal stem cell transplantation is a promising new clinical strategy for the treatment of meniscal tears in the avascular zone.

Animals↗

PubMed2005

The cellular origin of cartilage-like tissue after periosteal transplantation of full-thickness articular cartilage defects: an experimental study using transgenic rats expressing green fluorescent protein.

BACKGROUND: Periosteal transplantation is commonly used for the treatment of articular cartilage defects. However, the cellular origin of the regenerated tissue after periosteal transplantation has not been well defined. The objective of this study was to investigate the cellular origin of the regenerated tissue after periosteal transplantation. METHOD: Free periosteum was harvested from the tibia of 10-week-old adolescent enhanced green fluorescent protein (GFP-) expressing transgenic Sprague Dawley (SD) rats and was transplanted to full-thickness articular cartilage defects of the patellar groove in normal 10-week-old adolescent SD rats. The periosteum was sutured to the defect with the cambium layer facing the joint cavity. 8 SD rats were killed at 4 weeks and 8 SD rats were killed at 8 weeks after surgery. The repaired tissue was assessed histologically and histochemically. GFP-positive cells derived from the donor periosteum could easily be detected in the repaired tissue by use of a fluorescent microscope. RESULTS: At both 4 and 8 weeks after transplantation, the entire area of the defects had been repaired, with the regenerated tissue being well stained histologically with safranin-O. Most cells in the whole area of the regenerated tissue were GFP-positive, indicating that very few of the cells were GFP-negative cells originating from the recipient rats. INTERPRETATION: This experiment demonstrates that most cells in regenerated tissue after periosteal transplantation using adolescent animals do not originate from recipient cells but from the periosteal cells of the donor.

Animals↗

PubMed2004

Torn discoid lateral meniscus treated using partial central meniscectomy and suture of the peripheral tear.

We present the cases of 5 patients with a torn discoid lateral meniscus treated using partial central meniscectomy in conjunction with the suture repair of the tear. The patients were 4 boys and 1 girl with a mean age of 15.4 years (range, 11 to 17). Preoperatively, all patients complained of knee pain during daily or sports activities. At the final follow-up evaluation, more than 2 years later, 4 patients' conditions were graded as excellent and 1 patient's condition was graded as fair according to Ikeuchi's grading scale. The average Lysholm score improved from 83.4 points (range, 70-90) to 95.8 points (range, 89-100) postoperatively. In the 3 patients who underwent second-look arthroscopy, complete healing was seen in 2 patients. One patient had severe degenerative changes in the meniscus; the repaired site was not united and required an additional partial meniscectomy along the tear. We believe that with the current advancement in arthroscopic meniscal repair techniques, a partial central meniscectomy in conjunction with the suture repair of the peripheral tear can be effective treatment for patients with a torn complete or incomplete discoid meniscus.

Adolescent↗