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Atsumasa Uchida

Publications and source records attributed to Atsumasa Uchida.

At least 19 recordsLinked to original sources
PubMed2006

Expression of hypoxia-inducible factor (HIF)-1alpha as a biomarker of outcome in soft-tissue sarcomas.

Hypoxia-inducible factor (HIF)-1alpha is a transcription factor that supports the adaptation of human cancer cells to hypoxia and tumor growth and progression. The overexpression of HIF-1alpha protein has been reported to be associated with a worse prognosis in various cancers. However, the expression of HIF-1alpha in soft-tissue sarcomas has not yet been characterized. The expression of HIF-1alpha protein was immunohistochemically determined in 49 specimens of soft-tissue sarcomas including malignant fibrous histiocytoma (29 patients), synovial sarcoma (12 patients), leiomyosarcoma (four patients), and malignant peripheral nerve sheath tumors (four patients). The 49 samples consisted of 40 primary lesions and nine local recurrences. An immunohistochemical analysis showed the nuclear accumulation of HIF-1alpha protein in 35 (71.4%) samples. The expression of HIF-1alpha was negative in 14 (28.6%) cases, weak in nine (18.4%), moderate in 17 (35.4%), and strong in nine (18.4%). The patients with a strong or moderate expression of HIF-1alpha had a significantly shorter overall survival rate in comparison with those with a weak or negative expression in a univariate analysis (P = 0.029; log-rank test) and multivariate analysis (P = 0.018). This is the first report that demonstrated an overexpression of HIF-1alpha protein to be an independent prognostic factor for soft-tissue sarcomas.

Adult↗
PubMed2006

Effect of tourniquet application on deep vein thrombosis after total knee arthroplasty.

INTRODUCTION: There is a great deal of controversy about the effect of tourniquets on development of deep vein thrombosis (DVT) after total knee arthroplasty (TKA). PATIENTS AND METHODS: We investigated the incidence of postoperative DVT after TKA with or without the use of a tourniquet. The patients were 48 consecutive patients undergoing primary ipsilateral cemented TKA for osteoarthritis. Group A (21 patients) underwent the operation without a tourniquet, and Group B (27 patients) underwent the operation with a tourniquet. Ultrasonography to assess DVT was performed before and after the operation. RESULTS: Group B had less intraoperative and total blood loss than Group A. Postoperative DVT was detected in 81.3% of all cases, and symptomatic pulmonary embolism occurred in 1.7%. Most of DVT was found in the calf vein. There was no significant difference in the incidence of postoperative DVT between the two groups. CONCLUSION: We conclude that the use of a tourniquet is beneficial, because it decreases perioperative blood loss and does not increase the risk of DVT. The incidence of DVT after TKA is considerably high with or without use of a tourniquet. Therefore, prevention and early detection of DVT are important for prevention of fatal pulmonary thromboembolism.

Aged↗
PubMed2006

A new evaluation method for lumbar spinal instability: passive lumbar extension test.

BACKGROUND AND PURPOSE: Although many studies have described clinical examination measures for the diagnosis of lumbar spinal instability, few of them have investigated the sensitivity and specificity of the measures that were used. The authors devised a passive lumbar extension (PLE) test for assessing lumbar spinal instability. The purpose of this study was to investigate the sensitivity, specificity, and positive likelihood ratio of this test. SUBJECTS AND METHODS: The PLE test as well as the instability catch sign, painful catch sign, and apprehension sign tests were done for 122 subjects with lumbar degenerative diseases. The subjects were divided into 2 groups-instability positive and instability negative-on the basis of findings on flexion-extension films of the lumbar spine. The sensitivity, specificity, predictive values, and positive likelihood ratio of each test were investigated. RESULTS: The sensitivity and specificity of the PLE test were 84.2% and 90.4%, respectively. These values were higher than those of other signs. The positive likelihood ratio of the PLE test was 8.84 (95% confidence interval=4.51-17.33). DISCUSSION AND CONCLUSION: The PLE test is an effective method for examining patients for lumbar spinal instability and can be performed easily in an outpatient clinic.

Adult↗
PubMed2006

Dislocation of posterior-stabilized mobile-bearing knee prosthesis. A case report.

Spin-out of mobile-bearing knees is a significant early complication of mobile-bearing total knee arthroplasty. Dislocation of the cam-post mechanism of fixed-bearing posterior-stabilized knees occurs more rarely. We have observed an unusual case of dislocation of posterior-stabilized rotating-platform total knee arthroplasty, which has both a cam-post mechanism and rotating platform. A 65-year-old man with knee osteoarthritis and cervical spondylotic myelopathy underwent total knee arthroplasty using a mobile-bearing prosthesis. The dislocation, which occurred 4 days postoperatively, could not be reduced by closed manipulation. However, spontaneous reduction occurred 6 days after the dislocation, which did not recur. A gap mismatch or trapezoidal-shaped gaps may lead to dislocation or spin-out of the bearing insert. This case illustrates that dislocation of a posterior-stabilized mobile-bearing total knee arthroplasty can occur, and both quadriceps deficiency and ligament laxity may contribute to the risk of dislocation.

Aged↗
PubMed2006

A large metallic cyst caused by wear particles after total knee arthroplasty.

INTRODUCTION: A symptomatic cyst is an uncommon complication after total knee arthroplasty (TKA). We present a case of a 77-year-old woman with a large cyst in the right knee caused by metal wear debris from the failure of a Miller-Galante I TKA performed 13 years earlier. CASE PRESENTATION: The patient was treated with a two-stage operation including revision of the TKA followed by excision of the cyst, because there was a direct communication between the joint cavity and the cyst, and because the patient reported pain corresponding to the cystic area after revision. The patient was pain-free and had a satisfactory result 17 months after the second operation, without recurrence of cyst formation. CONCLUSION: We recommend two-stage surgery in which the first-stage is correction of the intra-articular pathology with revision TKA and the second-stage is excision of the cyst.

Aged↗
PubMed2006

Suicide during hospitalization in patients with spinal disease.

STUDY DESIGN: A retrospective study. OBJECTIVE: To examine the frequency and current status of the incidence of deaths by suicide of patients with spinal diseases during hospitalization. SUMMARY OF BACKGROUND DATA: It was reported that most cases of deaths by suicide during hospitalization were patients admitted to the psychiatric ward. There were no reports to the incidence of death by suicide during hospitalization in patients with spinal diseases. METHODS: Of 69,861 patients admitted to the Department of Orthopedics of 28 affiliated hospitals of our university between September 1997 and August 2002, 14,987 patients with spinal diseases were targeted for this study. We examined the number of deaths by suicide during hospitalization. RESULTS: Of the 14,987 patients with spinal diseases, there were 5 deaths (0.03%) by suicide during hospitalization. There were no deaths by suicide in 54,874 patients with orthopedic diseases other than spinal diseases. CONCLUSION: In the treatment of patients with spinal diseases, it seemed important for spinal surgeons to provide comprehensive treatment for the whole patient by paying attention to the relationship between a patient and a physician, in particular, by carefully observing the psychologic status of a patient.

Adult↗
PubMed2006

Effects of driving on low back pain.

BACKGROUND: Many previous studies have demonstrated that driving a car is a risk factor for low back pain (LBP). We have frequent contact with medical representatives who often drive cars for business, and have noticed that many of them suffer from LBP. AIMS: To investigate how driving affected the occurrence of LBP in medical representatives. METHODS: Questionnaire survey of all medical representatives working in Mie Prefecture (Japan). RESULTS: A total of 551 medical representatives replied (92%). We divided the subjects into Group A (with LBP) and Group B (without LBP). There was no significant difference in mean age, height, weight or duration of continuous employment between the two groups. Mean total mileage was 342 539 km in Group A and 251 945 km in Group B (P < 0.05). There was no significant difference in estimated daily mileage or estimated daily driving time between the two groups. As for backrest inclination, most of the respondents in Group A chose 105 degrees and the majority in Group B chose 120 degrees (P < 0.001). CONCLUSION: The total mileage was significantly higher in Group A than in Group B. We considered that the risk for LBP increased as the lumbar spine load accumulated day by day while driving a car almost every day without a holiday.

Adult↗
PubMed2006

Platelet-rich plasma (PRP) stimulates the extracellular matrix metabolism of porcine nucleus pulposus and anulus fibrosus cells cultured in alginate beads.

STUDY DESIGN: In vitro assessment of the effects of platelet-rich plasma on the extracellular matrix metabolism of porcine intervertebral disc cells. OBJECTIVES: To determine whether platelet-rich plasma is effective in stimulating cell proliferation and extracellular matrix metabolism by porcine disc cells cultured in alginate beads. SUMMARY OF BACKGROUND DATA: Platelet-rich plasma is used to accelerate wound healing and tissue regeneration. Activated platelets release multiple growth factors that regulate cell proliferation, differentiation, and morphogenesis. Individual growth factors present in platelet-rich plasma have been demonstrated to affect the metabolism of intervertebral disc cells. METHODS: Platelet-poor and platelet-rich plasma was isolated from fresh porcine blood using a commercially available platelet concentration system. After preculture for 7 days and serum starvation for 24 hours, the beads containing nucleus pulposus and anulus fibrosus cells were then cultured for another 72 hours in serum-free medium, 10% fetal bovine serum, 10% platelet-poor plasma, or 10% platelet-rich plasma. The synthesis of proteoglycans and collagen, the accumulation of proteoglycans, and the DNA content were biochemically assessed. RESULTS: Platelet-rich plasma had a mild stimulatory effect on cell proliferation of intervertebral disc cells. Platelet-rich plasma treatment significantly upregulated proteoglycan and collagen synthesis and proteoglycan accumulation when compared with platelet-poor plasma. CONCLUSIONS: Platelet-rich plasma was effective in stimulating cell proliferation and extracellular matrix metabolism. The response to platelet-rich plasma was greater in the case of anulus fibrosus cells than of nucleuspulposus cells. The local administration of platelet-rich plasma might stimulate intervertebral disc repair. In addition, given the risks of using animal serum for tissue engineering, autologous blood may gain favor as a source of growth factors and serum supplements needed for stimulating cells to engineer intervertebral disc tissues.

Animals↗
PubMed2006

Calcium phosphate cement in musculoskeletal tumor surgery.

BACKGROUND AND OBJECTIVES: Calcium phosphate cement (CPC) is an injectable biocompatible bone substitute that has been used for various applications in orthopedic surgery. However, no extensive clinical studies of the use of CPC to fill bone cavities after curettage of musculoskeletal tumors have been reported. The present study reviewed the results for 56 musculoskeletal tumors treated by curettage and CPC implantation. METHODS: Assessment was based on clinical examination and radiographic findings. Variables for clinical assessment included pain, limb function, and complications. Median follow-up was 18.5 months (range 6-47 months). RESULTS: One patient experienced post-operative fractures. Three patients displayed local recurrence. One patient developed post-operative superficial wound infection, and two patients with large bony defect exhibited non-infectious serous discharge. No serious adverse effects such as deep venous thrombosis, pulmonary embolism were encountered. In all cases, CPC was radiographically well adapted to the surrounding host bone as of final follow-up. CONCLUSIONS: CPC appears to offer a useful bone substitute for the treatment of musculoskeletal tumors. As the follow-up period for this study was short, further long-term follow-up studies are needed.

Adolescent↗
PubMed2006

Low-dose methotrexate inhibits lung metastasis and lengthens survival in rat osteosarcoma.

Lung metastasis is the most crucial event affecting the treatment of osteosarcoma and is dependent on tumor angiogenesis. To improve the prognosis for patients with osteosarcoma, prevention of lung metastasis is essential. Low-dose methotrexate is a useful drug for treating a variety of diseases. Low-dose methotrexate reportedly plays a role in antiangiogenesis for the synovial blood vessels in rheumatoid arthritis. However, whether low-dose methotrexate is correlated with tumor angiogenesis and metastasis is unclear. We investigated the inhibitory effect of methotrexate on lung metastasis in a rat osteosarcoma cell line with high metastatic potential, S-SLM. Two weeks after inoculation of S-SLM cells into male Fischer 344 rats, low-dose methotrexate (1.2 mg/kg once or twice a week) or saline was intraperitonealy injected for 4 weeks and the antimetastatic effect was evaluated. Low-dose methotrexate significantly reduced the number of lung metastatic nodules and the wet weight of the lungs. Immunohistochemical staining showed a decrease in microvessel density in the metastatic nodules. We also evaluated the effect of methotrexate on the proliferation of endothelial cells and S-SLM osteosarcoma cells in vitro. Methotrexate significantly inhibited the proliferation of endothelial cells at a lower concentration than that of S-SLM osteosarcoma cells. These data suggest that low-dose methotrexate inhibited lung metastasis of osteosarcoma through its antiangiogenic activity. Our results indicate that low-dose methotrexate is a promising drug for tumor dormancy therapy in patients with osteosarcoma and lung metastasis.

Animals↗
PubMed2006

Bilateral hip fractures.

BACKGROUND: In the past, patients admitted for hip fractures had often sustained a contralateral hip fracture. The incidence of bilateral hip fractures has been reported to be 5%-10%, and in the future the number of bilateral hip fractures is expected to increase with the increase of unilateral hip fractures. We believe that bilateral hip fractures can be efficiently prevented if a fracture on the other side could be predicted after unilateral hip fracture. Therefore, this retrospective study of 835 patients with hip fractures investigated the incidence, prognosis, and risk factors of bilateral hip fractures. METHODS: We examined 835 hip fractures retrospectively in Japan. Among them, we found 94 patients with bilateral noncontemporary hip fractures. We investigated age, sex, interval between the two fractures, type of fractures, cause, physical functioning, and complications. Differences between the unilateral fracture and bilateral fractures groups were analyzed statistically for age, sex, and complications using Student's t test and the chi-square test. RESULTS: In this study, the mean interval between two fractures was 4.28 years, and the second hip fracture occurred within 5 years in more than 70% of patients. The type of hip fracture was the same in 72.2% of bilateral hip fractures. No difference in age and sex was found between the unilateral and the bilateral groups. However, concerning complications, 22.1% of patients in the unilateral group and 34.8% in the bilateral group had dementia, the difference being significant. CONCLUSIONS: These results revealed that the second hip fracture occurred within 5 years of the first in more than 70% of bilateral hip fracture patients and that dementia is a risk factor of bilateral hip fractures.

Accidental Falls↗
PubMed2006

Regenerating axons emerge far proximal to the coaptation site in end-to-side nerve coaptation without a perineurial window using a T-shaped chamber.

BACKGROUND: Considerable controversy exists concerning the mechanism of axonal regeneration in end-to-side neurorrhaphy. The authors studied the mode of axonal regeneration in end-to-side neurorrhaphy without a perineurial window using a rat sciatic nerve model. METHODS: Twenty-seven rats were used. A 10-mm segment of peroneal nerve was harvested and coapted to the ipsilateral tibial nerve in end-to-side fashion using a T-shaped silicone chamber to minimize the tibial nerve damaged by surgery. To explain the role of nerve damage on axonal regeneration in end-to-side neurorrhaphy, we also used an isogenic nerve transplantation model in which the peroneal nerve remained intact. The mode of axonal regeneration was studied with electron microscopy, morphometric analysis, immunofluorescence, and immunohistochemistry. RESULTS: Both morphometric analysis and immunolabeling of neurofilaments demonstrated that regenerating axons emerge at sites far proximal to the coaptation site, travel within the tibial nerve, traverse the perineurium circumferentially around the coaptation site, and then invade into the peroneal nerve. Electron microscopy and a double-labeled immunofluorescence study with antibodies against neurofilament and tenascin-C confirmed large-scale axonal penetration into the perineurium around the coaptation site. Immunofluorescence with antibody against NG2, a marker of axonal regeneration, prevented the possibility of collateral sprouting at the coaptation site. In addition, an end-to-side neurorrhaphy model with an isogenic peroneal nerve clearly demonstrated that nerve damage is a prerequisite for axonal regeneration through end-to-side neurorrhaphy. CONCLUSIONS: The authors could not locate the site of axonal sprouting in end-to-side neurorrhaphy without a perineurial window; however, this study cast doubts on current hypothesis on the mode of axonal regeneration in end-to-side neurorrhaphy.

Animals↗
PubMed2006

Computed tomographic evaluation of component position on dislocation after total hip arthroplasty.

True proper position after total hip arthroplasty was determined by measuring the cup and stem anteversion using computed tomography. We compared 20 dislocated hips (14 posterior and 6 anterior) with 18 non-dislocated hips. Both the cup anteversion and the stem anteversion showed no differences among the groups. The sum of cup and stem anteversion in posterior dislocated hips was significantly lesser than that in non-dislocated hips and the sum in anterior dislocated hips was significantly greater than that in non-dislocated hips. These results suggested even if the cup alone or the stemalone is at proper position, dislocation might occur.

Aged↗
PubMed2006

Ultrastructural characterization of tissue response to sintered carbonate apatite in rabbit bone.

Our previous in vivo and in vitro studies revealed excellent tissue biocompatibility and osteoconductivity of porous sintered carbonate apatite (CA). The present study focused on the ultrastructural details of cells involved in the degradation of CA and new bone formation. Electron microscopy indicated that multinucleated giant cells (MNGCs) were actively involved in CA resorption. MNGCs extended their irregular cytoplasmic protrusions deeply into the interstitial spaces between CA particles. Endophagosomes were formed by encircling partially dissolved or intact CA crystals via the development of pseudopodia-like cytoplasmic protrusions, the configuration of which was somewhat different from that of the typical ruffled border of bone-resorbing osteoclasts. Subsequently, most CA particles in MNGCs were irregular in shape, suggesting that acidic degradation of CA occurred mainly intracellularly. Mononuclear cells, such as macrophage-like and/or fibroblast-like cells, also took up and degraded some CA. Growth of very thin needle-like crystals was observed in close association with CA. Osteoblasts directly faced the CA and secreted osteoid matrix. At the CA-bone interface, an electron-dense and homogeneous thin layer free of collagen fibers was sometimes observed, suggesting an involvement in CA-bone bonding.

Animals↗
PubMed2006

[Quality of life in patients with metastatic spinal tumors].

The authors investigated the postoperative quality of life in 89 patients with metastatic spinal tumors. As the results of our study, it was found that spinal surgery could maintain or improve the quality of life, and then most of patients with poor quality of life had multiple spine/bone metastasis or brain/spinal cord metastasis.

Activities of Daily Living↗