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Biomedical subjects

Tomoyuki Matsumoto

Publications and source records attributed to Tomoyuki Matsumoto.

13 recordsLinked to original sources
PubMed2007

In vitro multipotentiality and characterization of human unfractured traumatic hemarthrosis-derived progenitor cells: A potential cell source for tissue repair.

Mesenchymal progenitor cells (MPCs) are a very attractive tool in the context of repair and regeneration of musculoskeletal tissue damaged by trauma. The most common source of MPCs to date has been the bone marrow, but aspirating bone marrow from the patient is an invasive procedure. In an attempt to search for alternative sources of MPCs that could be obtained with minimal invasion, we looked into traumatic hemarthrosis of the knee. In this study, we determined whether a population of multipotent MPCs could be isolated from acute traumatic knee hemarthrosis in the absence of intra-articular fractures. Mononuclear cells were isolated from the aspirated hemarthrosis by density gradient separation, and cultured. We were able to obtain plastic adherent fibroblast-like cells from the mononuclear cell fractions. Flow cytometry analysis revealed that the adherent fibroblast-like cells were consistently positive for CD29, CD44, CD105, and CD166, and were negative for CD14, CD34, and CD45. These were similar to control bone marrow stromal cells. These cells could differentiate in vitro into osteogenic, adipogenic, and chondrogenic cells in the presence of lineage-specific induction factors. In conclusion, acute unfractured traumatic hemarthrosis of the knee contains MPCs with multipotentiality. Because knee hemarthrosis is easy to harvest with minimal pain and without unnecessary invasion, we regard hemarthrosis-derived cells as an additional progenitor cell source for future tissue engineering and cell-based therapy in knee injuries.

Adolescent↗
PubMed2006

Dose-dependent contribution of CD34-positive cell transplantation to concurrent vasculogenesis and cardiomyogenesis for functional regenerative recovery after myocardial infarction.

BACKGROUND: Multilineage developmental capacity of the CD34+ cells, especially into cardiomyocytes and smooth muscle cells (SMCs), is still controversial. In the present study we performed a series of experiments to prove our hypothesis that vasculogenesis and cardiomyogenesis after myocardial infarction (MI) may be dose-dependently enhanced after CD34+ cell transplantation. METHODS AND RESULTS: Peripheral blood CD34+ cells were isolated from total mononuclear cells of patients with limb ischemia by apheresis after 5-day administration of granulocyte colony-stimulating factor. PBS and 1x10(3) (low), 1x10(5) (mid), or 5x10(5) (high) CD34+ cells were intramyocardially transplanted after ligation of the left anterior descending coronary artery of nude rats. Functional assessments with the use of echocardiography and a microtip conductance catheter at day 28 revealed dose-dependent preservation of left ventricular function by CD34+ cell transplantation. Necropsy examination disclosed dose-dependent augmentation of capillary density and dose-dependent inhibition of left ventricular fibrosis. Immunohistochemistry for human-specific brain natriuretic peptide demonstrated that human cardiomyocytes were dose-dependently observed in ischemic myocardium at day 28 (high, 2480+/-149; mid, 1860+/-141; low, 423+/-9; PBS, 0+/-0/mm2; P<0.05 for high versus mid and mid versus low). Immunostaining for smooth muscle actin and human leukocyte antigen or Ulex europaeus lectin type 1 also revealed dose-dependent vasculogenesis by endothelial cell and SMC development after CD34+ cell transplantation. Reverse transcriptase-polymerase chain reaction indicated that human-specific gene expression of cardiomyocyte (brain natriuretic peptide, cardiac troponin-I, myosin heavy chain, and Nkx 2.5), SMC (smooth muscle actin and sm22alpha), and endothelial cell (CD31 and KDR) markers were dose-dependently augmented in MI tissue. CONCLUSIONS: Human CD34+ cell transplantation may have significant and dose-dependent potential for vasculogenesis and cardiomyogenesis with functional recovery from MI.

Animals↗
PubMed2006

Joint gap kinematics in posterior-stabilized total knee arthroplasty measured by a new tensor with the navigation system.

BACKGROUND: The management of soft tissue balance during surgery is essential for the success of total knee arthroplasty (TKA) but remains difficult, leaving it much to the surgeon's feel. Previous assessments for soft tissue balance have been performed under unphysiological joint conditions, with patellar eversion and without the prosthesis only at extension and 90 deg of flexion. We therefore developed a new tensor for TKA procedures, enabling soft tissue balance assessment throughout the range of motion while reproducing postoperative joint alignment with the patellofemoral (PF) joint reduced and the tibiofemoral joint aligned. Our purpose in the present study was to clarify joint gap kinematics using the tensor with the CT-free computer assisted navigation system. METHOD OF APPROACH: Joint gap kinematics, defined as joint gap change during knee motion, was evaluated during 30 consecutive, primary posterior-stabilized (PS) TKA with the navigation system in 30 osteoarthritic patients. Measurements were performed using a newly developed tensor, which enabled the measurement of the joint gap throughout the range of motion, including the joint conditions relevant after TKA with PF joint reduced and trial femoral component in place. Joint gap was assessed by the tensor at full extension, 5 deg, 10 deg, 15 deg, 30 deg, 45 deg, 60 deg, 90 deg, and 135 deg of flexion with the patella both everted and reduced. The navigation system was used to obtain the accuracy of implantations and to measure an accurate flexion angle of the knee during the intraoperative joint gap measurement. RESULTS: Results showed that the joint gap varied depending on the knee flexion angle. Joint gap showed an accelerated decrease during full knee extension. With the PF joint everted, the joint gap increased throughout knee flexion. In contrast, the joint gap with the PF joint reduced increased with knee flexion but decreased after 60 deg of flexion. CONCLUSIONS: We clarified the characteristics of joint gap kinematics in PS TKA under physiological and reproducible joint conditions. Our findings can provide useful information for prosthetic design and selection and allow evaluation of surgical technique throughout the range of knee motion that may lead to consistent clinical outcomes after TKA.

Aged↗
PubMed2006

Therapeutic potential of vasculogenesis and osteogenesis promoted by peripheral blood CD34-positive cells for functional bone healing.

Failures in fracture healing are mainly caused by a lack of vascularization. Adult human circulating CD34+ cells, an endothelial/hematopoietic progenitor-enriched cell population, have been reported to differentiate into osteoblasts in vitro; however, the therapeutic potential of CD34+ cells for fracture healing is still unclear. Therefore, we performed a series of experiments to test our hypothesis that functional fracture healing is supported by vasculogenesis and osteogenesis via regenerative plasticity of CD34+ cells. Peripheral blood CD34+ cells, isolated from total mononuclear cells of adult human volunteers, showed gene expression of osteocalcin in 4 of 20 freshly isolated cells by single cell reverse transcriptase-polymerase chain reaction analysis. Phosphate-buffered saline, mononuclear cells, or CD34+ cells were intravenously transplanted after producing nonhealing femoral fractures in nude rats. Reverse transcriptase-polymerase chain reaction and immunohistochemical staining at the peri-fracture site demonstrated molecular and histological expression of human-specific markers for endothelial cells and osteoblasts at week 2. Functional bone healing assessed by biomechanical as well as radiological and histological examinations was significantly enhanced by CD34+ cell transplantation compared with the other groups. Our data suggest circulating human CD34+ cells have therapeutic potential to promote an environment conducive to neovascularization and osteogenesis in damaged skeletal tissue, allowing the complete healing of fractures.

Angiogenesis Inhibitors↗
PubMed2006

Clinical values in computer-assisted total knee arthroplasty.

Thirty posterior stabilized total knee prostheses implanted using a computed tomography-free navigation system were compared to a control group of 30 matched total knee prostheses of the same type implanted via a classical, surgeon-controlled technique. The accuracy of the implantations in relation to the mechanical axis in the navigation group was superior to that of the manual group. Early two-year clinical results including range of motion and Knee Society Clinical Rating Score were equally good compared to the manual group. However, potential long-term outcome and functional improvement require further investigation.

Aged↗
PubMed2005

Bilateral painful snapping elbows triggered by daily dumbbell exercises: a case report.

We treated a 64-year-old female with bilateral painful snapping elbows due to synovial folds. Resection of the bilateral synovial folds resulted in relief from pain and snapping, and resulted in patient satisfaction. Daily dumbbell exercises of the bilateral elbows starting at an elderly age may have led to the bilateral snapping. Painful snapping elbow is a relatively rare condition, which usually occurs in a unilateral elbow of a younger patient. To our knowledge, bilateral painful snapping elbows triggered by daily dumbbell exercises in older patients have not been previously reported.

Arthralgia↗
PubMed2005

Influence of hip position on knee flexion angle in patients undergoing total knee arthroplasty.

The influence of hip position on knee flexion angle before total knee arthroplasty (TKA) and that after TKA were investigated and compared. Sixty-six patients (70 knees) with osteoarthritis who were undergoing TKA were examined using lateral radiographs of maximum knee flexion angle with the hip joint at 0 degrees extension and 90 degrees flexion. The postoperative rate of decrease in knee flexion angle caused by hip extension was significantly larger compared with the value before surgery. The preoperative rate of decrease in knee flexion angle caused by hip extension showed strong inverse correlation with the preoperative and postoperative knee flexion angle ratio. In conclusion, tightness of the extensor mechanism is present in all knees undergoing TKA and especially has a strong influence on the postoperative flexion angle of the knee.

Arthroplasty, Replacement, Knee↗
PubMed2005

Traumatic dislocation of the hamate and pisiform: a case report and review of the literature.

Isolated dislocation of the hamate bone and pisiform bone is rare. We describe the simultaneous complete dislocation of both the hamate and pisiform bones in a 27-year-old man who crushed his right hand in a rolling press. An open reduction and internal fixation with Kirschner wires was performed. Four weeks later, the Kirschner wires were removed and rehabilitation was started. At 6 months follow-up, the patient had minimal pain and full range of motion in the affected wrist joint and fingers. However, grip strength was 50% compared to his unaffected left hand, and sensation of the ulnar nerve area was reduced to almost 30% of that of his left hand. It appears that the ulnar nerve injury was the largest contributing factor to the poor outcome of our patient. Evaluation of soft-tissue injuries, especially nerve injury, is important in the treatment of complex carpal dislocations.

Adult↗
PubMed2004

Prosthetic alignment and sizing in computer-assisted total knee arthroplasty.

We implanted 60 posterior stabilized total knee prostheses (P.F.C. Sigma, DePuy, Warsaw, USA). In 30 cases, we used a CT-free navigation system (Vector Vision, Brain LAB, Heimstetten, Germany), and in 30 matched-paired controls, we used a conventional manual implantation. We compared postoperative long-leg radiographs in the two groups. The results revealed a significant difference in favor of navigation. In addition, we compared the preoperative anteroposterior dimension of the femoral condyle with the postoperative value. While there were no significant differences in the preoperative anteroposterior dimension of the femoral condyle between the two groups, the postoperative value in the navigation group was significantly larger than that of the preoperative value. Therefore, surgeons using navigation systems should guard against the possibility of oversizing when determining the size of the femoral component.

Aged↗
PubMedDate not supplied

Enlarging retro-odontoid pseudotumor after expanding cervical laminoplasty in the presence of kyphosis.

BACKGROUND CONTEXT: In cranio-vertebral junction, retro-odontoid pseudotumor without evidence of rheumatoid arthritis is a rare condition. PURPOSE: To discuss the mechanism of enlarging retro-odontoid pseudotumor after expanding cervical laminoplasty as a predictable complication. STUDY DESIGN: We report a rare case of an elderly man with non-inflammatory retro-odontoid pseudotumor after cervical expanding laminoplasty. PATIENT SAMPLE: A 76-year-old man presented with progressive quadriparesis of two week's duration caused by enlarging retro-odontoid soft tissue mass after cervical laminoplasty. OUTCOME MEASURES: Pre- and postoperative image, including X-ray and MRI, and the Japanese Orthopaedic Association scores for cervical myelopathy were assessed. METHODS: The patient subsequently underwent resection of the posterior arch of the atlas and posterior fusion from the occiput to C6 using Olerud system without removal of the retro-odontoid soft tissue mass. RESULTS: One year after surgery, the Japanese Orthopaedic Association scores for cervical myelopathy improved from 1 to 10 points, and postoperative MRI showed a mild reduction in the size of the retro-odontoid soft tissue mass. CONCLUSIONS: The kyphotic stability from C3 to C7 after laminoplasty, leading to a compensatory hyperlordosis at the occipitocervical junction, may cause the development of a degenerative osteoarthritic change, resulting in the production of an enlarging mass. Not only posterior compression of spinal cord due to posterior arch of the hyperextended atlas but also anterior compression of spinal cord due to retro-odontoid pseudotumor probably triggered the severe myelopathy. Laminoplasty may be inappropriate in cervical myelopathy with kyphosis.

Aged↗