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S Yoshiya

Publications and source records attributed to S Yoshiya.

34 records · Page 2Linked to original sources

Effect of basic fibroblast growth factor on the healing of defects in the canine anterior cruciate ligament.

The effect of basic fibroblast growth factor (bFGF) on the healing of partial anterior cruciate ligament (ACL) lacerations was investigated in 17 adult mongrel canines. The defect was created in the midsubstance of both ACLs using a biopsy punch. In the bFGF group, a bFGF-impregnated pellet was sutured to the infrapatellar fat pad close to the defect. In the control group, the same pellet without bFGF was used. The healing process was evaluated macroscopically and histologically at 1, 3, 6, and 24 weeks postoperatively. In the bFGF group, a pannus-like tissue which contained abundant blood vessels extended into the defect from the adjacent synovial tissue in the early postoperative phase. Histological examination of the tissue which filled the defect revealed initial remodeling processes with a decreased number of cells and better orientation of the collagen fibers at 6-24 weeks. On the other hand, in the control group, poor healing processes were observed at each examination period. This study demonstrated that the application of a bFGF-impregnated pellet may enhance the healing potential of a partially injured ACL. Enhanced neovascularization and the formation of granulation tissue induced by bFGF early in the healing process accounted for the increased healing response.

Animals↗

Effect of fibrin glue and endothelial cell growth factor on the early healing response of the transplanted allogenic meniscus: a pilot study.

Twentyfour meniscal allotransplantations were conducted in 12 adult mongrel dogs. The medial meniscus was replaced using a deep-frozen meniscal allograft. The junction between the meniscus and capsule was treated in one of the three ways. In the control group, the meniscus was sutured only to the adjacent capsular tissue (group C). In the second group, fibrin glue was injected at the junction (group F), and in the third group, fibrin glue and endothelial cell growth factor (ECGF) were injected at the juncture between the transplanted meniscus and the adjacent capsule before the meniscus was sutured (group FE). Histological observation was performed to investigate the effect of fibrin glue and ECGF on the healing process of transplants at various intervals of 1, 4, 8 and 12 weeks. No immunological response was noted in any of the knees. The healing of the transplanted meniscus was first observed at the peripheral attachment. Also, the pannus-like tissue extended from the synovium to the surface of the meniscus. The healing rate in each group at 1 week and 12 weeks was 22% and 77% in group C, 52% and 80% in group F, and 64% and 80% in group FE, respectively. At 4 and 8 weeks, early cellular repopulation was found in group FE and the area which contained new cells was larger than the acellular central core at 8 weeks. However, there was no difference among the three groups at 12 weeks.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Light and electron microscopic study of remodeling and maturation process in autogenous graft for anterior cruciate ligament reconstruction.

We evaluated the remodeling process of autogenous patellar tendon graft for anterior cruciate ligament (ACL) reconstruction by means of light microscopic (LM) and electron microscopic (EM) examinations from the biopsy specimens obtained at the time of second-look arthroscopy. Twenty-one patients were examined at various times postoperatively (from 6 weeks to 15 months, mean 9.5 months), and the results were correlated with the morphology of normal patellar tendon and normal ACL. Our study showed that the graft was revascularized in the early postoperative period, fibroblastic remodeling took place, and the graft obtained gross similarity to the original ACL on their arthroscopic and LM appearances at approximately 1 year postoperatively. However, EM study showed that at both approximately 6 months and 1 year postoperatively the grafts consisted equally of active fibroblasts with a higher cytoplasm-to-nucleus ratio compared with normal ACL. Collagen fibrils of these grafts were of uniformly small diameter compared with normal patellar tendon and ACL. Our results with ultrastructural study suggest that the grafts were still immature even at 1 year postoperatively.

Adolescent↗

Knee arthroscopy using local anesthetic.

The purpose of this study was to examine the effectiveness and safety of local anesthetics (a mixture of lidocaine and bupivacaine) in knee arthroscopy. Local anesthetic agents were shown to be effective and safe, based on chart review and measurement of blood levels of the anesthetic drugs.

Adult↗

Augmentation of anterior cruciate ligament reconstruction in dogs with prostheses of different stiffnesses.

The purpose of this study was to investigate the biological and biomechanical properties of anterior cruciate ligament (ACL) reconstruction augmented with Dacron prostheses of three different stiffnesses. The ACLs of 36 adult mongrel dogs were removed and the ligament was reconstructed. In 18 dogs, one knee was reconstructed with patellar tendon alone, and the contralateral knee with Dacron augmented patellar tendon. In the remaining 18 dogs, reconstruction was with Dacron augmented patellar tendon with Dacron alone being used for the contralateral control knee. Death was 3 months after surgery, and the reconstructions were examined biologically and biomechanically. The mechanical data were compared with immediate postoperative data obtained from 45 reconstructed fresh cadaveric knees. Tensile testing demonstrated that an increase in failure load was found when the implanted patellar tendon graft was compared with the cadaveric reconstruction. The strength of the Dacron augmented reconstruction showed little change while the Dacron alone graft decreased in strength during the period of implantation. No clear difference was found between the performance of augmentation devices of different stiffnesses. Microangiography showed that grafts were totally revascularized in patellar tendon alone, but not well revascularized in Dacron augmented patellar tendon and Dacron alone reconstruction. The presence of the Dacron appeared to have an adverse effect on revascularization.

Animals↗

Histologic and histochemical investigation of Gaucher cells.

Electron microscopic investigations suggest that morphologically, Gaucher cells and histiocytes are very similar. The fact that there are tubular elements in the lysosomes strongly suggests the possibility of lysosomes as the precursors of Gaucher bodies. By means of the lectin staining methods, the localization of glucocerebroside is clearly demonstrable in Gaucher cells. Lectin staining is the significant diagnostic feature of both Gaucher's and Krabbe's diseases.

Biopsy↗

Ossified intramuscular hemangioma: multimodality imaging findings.

Whereas calcification of hemangiomas is common, ossification is unusual. Multimodality imaging findings of a rare case of an ossified intramuscular hemangioma in the calf of a 24-year-old woman are presented. Radiographic, computed tomographic, magnetic resonance (MR), scintigraphic, and histologic features of this case are reported. The radiologic differential diagnosis of an ossified mass in soft tissue is also discussed.

Adult↗

Intraosseous lipoma of the humeral head: MR appearance.

Intraosseous lipoma is the rarest benign primary bone tumor. We report a case of juxtaarticular intraosseous lipoma in the humeral head of a 50-year-old man. Roentgenographic, computed tomographic (CT), magnetic resonance (MR), scintigraphic, and histologic findings of this case are presented.

Biopsy, Needle↗

A biomechanical comparison of different surgical techniques of graft fixation in anterior cruciate ligament reconstruction.

Different surgical methods of graft fixation in ACL reconstruction were examined to determine the effects on mechanical properties of the reconstructed ACL. Ten human cadavers were used in this study. Six different types of grafts were studied. The tendon grafts were removed from each cadaver and fixed to femurs and tibias as ACL substitutes with different surgical fixation methods, leaving femur-reconstructed graft-tibia preparations. The surgical techniques used were staple fixation, tying sutures over buttons, and screw fixation. In the latter, the screws were introduced through femoral and tibial drill holes from the outside in order to achieve interference fit as described by Lambert. Tensile testing demonstrated that the original ACL is significantly stronger than the graft used for reconstruction in linear load, stiffness, and maximum tensile strength. All of the failures of the reconstructed ACL grafts occurred at the fixation site, indicating that the mechanically weak link of the reconstructed graft is located at the fixation site. Among the different methods of fixation, one-third of the patellar tendon secured with a cancellous screw, especially with a custom designed large diameter screw, showed significantly higher values. Although many other factors affect the success of ACL reconstruction, our study indicates that the method of surgical fixation is the major factor influencing the graft's mechanical properties in the immediate postoperative period.

Adult↗

Graft tension in anterior cruciate ligament reconstruction. An in vivo study in dogs.

The purpose of this study was to examine the effect of initial tensioning on the outcome of reconstruction of the ACL. The ACLs of 15 adult mongrel dogs were excised and reconstructed. In the first five dogs, the ACLs of both knees were reconstructed using the medial one-third of the patellar tendon. The graft was fixed under a tension of 1 N (0.22 pounds) in one knee and 39 N (8.8 pounds) in the opposite knee. In the remainder of the dogs, the reconstructions were augmented with Dacron prostheses. Tensioning of both graft components in the augmented reconstructions was either with 1 N in one knee and 39 N in the contralateral knee or disproportionate tensions of 1 N and 39 N applied to the autogenous material and to the prosthesis. Sacrifice was 3 months postsurgery and results were examined with microangiography/history and mechanical testing. In the reconstructions with the patellar tendon alone, the biologic study showed poor vascularity and focal myxoid degeneration within the graft pretensioned with a load of 39 N. In the augmented reconstructions, the knees in which both graft materials were fixed with 1 N tension showed the strongest and stiffest reconstruction at 3 months. The study suggests that minimal tension should be applied to the graft materials during surgical reconstruction of the ACL.

Angiography↗

Meniscal repair using fibrin sealant and endothelial cell growth factor. An experimental study in dogs.

The effect of fibrin sealant and endothelial cell growth factor on the healing of defects of the avascular portion of canine menisci was investigated in 30 menisci of 15 adult mongrel dogs. The defects were treated in one of three ways: Group 1, the defect was left empty; Group 2, the defect was filled with fibrin sealant; and Group 3, the defect was filled with fibrin sealant and endothelial cell growth factor. The healing process was evaluated macroscopically and histologically at intervals of 1, 2, 6, 12, and 24 weeks. The average percentage of each defect that was filled with connective tissue was 5% in Group 1, 76.6% in Group 2, and 89.4% in Group 3. In the early phase of this repair, the extrinsic pannus-like tissue that contained many capillary vessels extended from the meniscosynovial junction into the defect. Subsequently, organized fibrous connective tissue was formed, which had changed to cartilaginous tissue at 12 to 24 weeks. The combination of fibrin sealant and endothelial cell growth factor enhanced the neovascularization and formation of granulation tissue, which accounted for the increased healing level in the avascular portion of the meniscus.

Animals↗