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Biomedical subjects

M Kurosaka

Publications and source records attributed to M Kurosaka.

At least 19 recordsLinked to original sources
PubMed2006

Change in the cross-sectional area of a patellar tendon graft after anterior cruciate ligament reconstruction.

The purpose of this study was to clarify the change in the cross-sectional area (CSA) of a patellar tendon graft after anterior cruciate ligament (ACL) reconstruction, and its relationship with postoperative knee laxity. Forty patients (25 men and 15 women) were included in this study. Intraoperative CSA measurements were performed with an instrumented areamicrometer, while a magnetic resonance imaging (MRI) evaluation was utilized for the assessment postoperatively. For intraoperative measurement, the average CSA of a 10-mm wide patellar tendon graft was 32.3 +/- 7.0 mm2, while the average CSA measured at follow-up (mean: 14.8 months) was 48.8 mm2, showing a significant mean increase ratio of 49.4%. This value corresponded to 115% of the native ACL. The average CSA measured in 30 patients at 6 months was 49.7 mm2, almost equal to the value at the final follow-up (49.8 mm2) in the same patient group. Among potentially influential factors, postoperative notch width (available space for the ACL graft) had significant correlation with the CSA of the graft at follow-up. Finally, both intra- and postoperative CSA values did not correlate with postoperative knee laxity, indicating that a bigger graft does not guarantee a better laxity.

Adolescent↗
PubMed2006

Treatment of a full-thickness articular cartilage defect in the femoral condyle of an athlete with autologous bone-marrow stromal cells.

OBJECTIVES: Human bone-marrow stromal cells are believed to be multipotent even in adults. This study assessed the effectiveness of autologous bone-marrow stromal cells, which were embedded within a collagen scaffold, to repair a full-thickness articular cartilage defect in the medial femoral condyle of an athlete. PATIENT AND METHODS: A 31-year-old male judo player suffering from pain in the right knee was reviewed. A 20 x 30-mm full-thickness cartilage defect (International Cartilage Repair Society classification (ICRS) grade IV) was revealed in the weight-bearing area of the medial femoral condyle. With the informed consent of the patient, the defect was treated with autologous bone-marrow stromal cells. Bone marrow was aspirated from the iliac crest of the patient 4 weeks before surgery. After removing the erythrocytes, the remaining cells were expanded in culture. Adherent cells were collected and embedded within a collagen gel, which was transferred to the articular cartilage defect in the medial femoral condyle. The implant was covered with an autologous periosteal flap. RESULTS: Seven months after surgery, arthroscopy revealed the defect to be covered with smooth tissues. Histologically, the defect was filled with a hyaline-like type of cartilage tissue which stained positively with Safranin-O. One year after surgery, the clinical symptoms had improved significantly. The patient had reattained his previous activity level and experienced neither pain nor other complications. CONCLUSIONS: Our findings indicate that the transplantation of autologous bone-marrow stromal cells can promote the repair of large focal articular cartilage defects in young, active patients.

Adult↗
PubMed2006

Radiculopathy due to microfibrillar collagen hemostat mimicking recurrence of disc herniation.

Microfibrillar collagen hemostat (Avitene) is an absorbable topical hemostatic agent prepared from purified bovine corium collagen. A 65-year-old woman presented with left buttock and lower extremity radicular pain. The patient underwent a disc excision in which Avitene was used to control venous bleeding from the epidural space. Leg pain decreased postoperatively, but she developed radicular pain when she started walking 3 days after the operation. Magnetic resonance imaging (MRI) performed post-operatively showed there was a mass lesion located between the dural sac and L5 nerve root. The lesion exhibited high signal intensity on T1-weighted images and higher signal intensity at the rim of the mass on T2-weighted images. A second operation performed 10 days later revealed that the nerve root was adherent to an extradural granulomatous mass associated with Avitene. Macroscopically, the resected mass was found to be composed mainly of microfibrillar collagen hemostat materials. Hemostat agents may produce a clinically symptomatic, radiologically apparent mass lesion. When considering a mass lesion arising after spine surgery, the differential diagnosis should include foreign body granuloma along with recurrent disc herniation and peridural scar formation.

Aged↗
PubMed2006

Osteogenic potential of cells in vitro derived from haemarthrosis of the knee induced by injury to the anterior cruciate ligament.

We have investigated whether cells derived from haemarthrosis caused by injury to the anterior cruciate ligament could differentiate into the osteoblast lineage in vitro. Haemarthroses associated with anterior cruciate ligament injuries were aspirated and cultured. After treatment with beta-glycerophosphate, ascorbic acid and dexamethasone or 1,25 (OH)(2)D(3), a significant increase in the activity of alkaline phosphatase was observed. Matrix mineralisation was demonstrated after 28 days and mRNA levels in osteoblast-related genes were enhanced. Our results suggest that the haemarthrosis induced by injury to the anterior cruciate ligament contains osteoprogenitor cells and is a potential alternative source for cell-based treatment in such injury.

Adolescent↗
PubMed2006

Effect of bubble flow velocity on drag-force and shear stress working on submerged hollow fibre membrane.

This study is aimed at elucidating the mechanism by which rising air bubbles induce shear stress on hollow fibre membrane surfaces. Shear stress on hollow fibre membrane surfaces (laterally-set and vertically-set) caused by aeration was measured directly using a two-direction load sensor. In the laterally-set hollow fibre module, time-averaged upward-direction shear stress on the membrane surface was compared to theoretical shear stress values considering the effect of water flow on membrane surface. Measured time-average shear stress values were almost 200 times larger than theoretical values implying strong interactions between bubbles and solid surface. In the vertically-set membrane module, velocity measurement of bubble flow using laser Doppler velocimeter revealed that drag force working on membrane surface was closely related to upward-direction water velocity. Also fluctuation of drag force and shear force on membrane surface was found to be related to velocity fluctuation (turbulence).

Bioreactors↗
PubMed2005

Anchorage on fibronectin via VLA-5 (alpha5beta1 integrin) protects rheumatoid synovial cells from Fas-induced apoptosis.

BACKGROUND: Rheumatoid synovial cells are resistant to apoptosis induction in vivo, whereas, fibroblast-like synovial cells in rheumatoid arthritis (RA-FLS) are vulnerable to Fas-induced apoptosis in vitro. OBJECTIVE: To clarify this discrepancy by studying the contribution of the interaction between cellular integrin and matrix fibronectin (Fn), which is significantly increased in the rheumatoid joints, to the induction of apoptosis in RA-FLS. METHODS: Integrin and Fas mRNAs were measured by reverse transcription-polymerase chain reaction in RA-FLS. Integrins expressed in rheumatoid synovial tissues were analysed by immunohistochemistry. RA-FLS plated either on Fn or on control poly-L-lysine were incubated with agonistic anti-Fas monoclonal antibodies (mAbs). Apoptosis induction was evaluated using terminal deoxynucleotidyl transferase mediated UTP nick end labelling (TUNEL) and immunoblotting for caspase-3 and poly (ADP-ribose) polymerase in the presence or absence of anti-VLA-5 mAb. RESULTS: VLA-5 (alpha5beta1 integrin), a major integrin expressed on RA-FLS, was required for the adhesion of RA-FLS on Fn. RA-FLS plated on Fn were more resistant to Fas-induced apoptosis than those plated on control poly-L-lysine. This protection by Fn was reversed by anti-VLA-5 mAb. CONCLUSION: Anchorage of RA-FLS on matrix Fn via VLA-5 protects RA-FLS from Fas-induced apoptosis, and Fn abundantly present in rheumatoid synovium appears to afford RA-FLS resistance against apoptosis induction in vivo.

Antibodies, Monoclonal↗
PubMed2005

Donor leukocytes combine with immunosuppressive drug therapy to prolong limb allograft survival.

Donor leukocytes administered at the time of transplantation may prolong organ allograft survival. This study examined the effectiveness of donor leukocyte injection combined with immunosuppression for limb transplantation across the strong histocompatibility barrier of a Brown Norway donor to a Lewis recipient. Eight animals received 6 x 10(7) donor leukocytes injected on the day of transplantation. From day 1, FK506 (2 mg/kg/d), mycophenolate mofetil (MMF) (15 mg/kg/d), and prednisone (0.5 mg/kg/d) were administered for 2 weeks. After week 2, prednisone and MMF were both tapered by 20% of the initial dosage per week. After week 7, the animals received only FK506 (2 mg/kg/d). From week 8, FK506 was tapered to the maintenance dose of 0.8 mg/kg/d at week 10 and was stopped on week 24. A control group of 8 animals underwent identical treatment except that the leukocyte injection was omitted. Rejection was observed in both groups during FK506 monotherapy; however, the onset of early rejection episodes was significantly later, the period for reversal of the first rejection was significantly shorter, and the dosage of FK506 at the time of rejection was significantly lower among leukocyte-treated recipients. After completion of immunosuppression, survival was modestly prolonged in the leukocyte-treated group. One animal is surviving without immunosuppression on day 234. This trial of donor leukocyte injection combined with immunosuppression in limb transplantation showed a modest, but significant, improvement in outcome.

Animals↗
PubMed2005

Donor leukocytes combined with delayed immunosupressive drug therapy prolong limb allograft survival.

Donor leukocytes administered at the time of transplantation may prolong organ allograft survival. Delayed administration of calcineurin inhibitors, such as FK506 or cyclosporine, may enhance their efficacy. Herein the effectiveness of this strategy to promote limb transplant survival was investigated in the strong histocompatibility barrier of Brown-Norway donor to Lewis recipients. Donor leukocytes (6 x 10(7) intravenously) were injected on the day of transplantation followed on day 1 to 14 with mycophenolate mofetil (MMF; 15 mg/kg/d) and prednisone, (0.5 mg/kg/d) which were then tapered by 20% each week and stopped at week 7. Administration of of FK506 (2 mg/kg/d) was started on day 4 and continued for 8 weeks, then tapered for 4 weeks to a maintenance dose of 0.8 mg/kg/d, which was continued for 12 weeks (group A; n = 8). A control group (n = 8) underwent identical treatment save for donor leukocyte injection but rather commencement of FK506 on day 1. Rejection was common during FK506 tapering in both groups. However group A showed a significantly later onset, a shorter period for reversal of the first rejection, and a significantly lower dosage of FK506 at the time of rejection. After the completion of immunosuppression, rejection occurred significantly later in group A than the control group with one animal surviving without immunosuppression on day 344. This is the first trial of a donor leukocyte injection combined with delayed FK506 administration in limb transplantation, which suggested that it could produce a modest but significant improvement in outcome.

Animals↗
PubMed2003

Production of adrenomedullin from synovial cells in rheumatoid arthritis patients.

It was recently reported that plasma levels of adrenomedullin (AM), identified as a vasorelaxant peptide, are significantly higher in rheumatoid arthritis (RA) patients than in osteoarthritis (OA) patients. The objective of the present study was to elucidate AM production in synovial cells from patients with RA. Adrenomedullin mRNA was detected in cultured synovial cells from RA patients by reverse transcription polymerase chain reaction (RT-PCR). Immunohistochemical analysis demonstrated the presence of AM in synovial cells from RA patients. In addition, we investigated AM levels in knee joint fluids from RA and OA patients. Those from RA patients were elevated approximately threefold over those of OA patients. In this study, we demonstrated for the first time AM expression in synovial cells from RA patients and high levels of AM production in RA joint fluid.

Adrenomedullin↗
PubMed2002

Effects of prophylactic ankle supports on pronation during gait.

We performed a gait analysis of 12 healthy subjects in order to analyse the rear foot pronation-supination angle and the shift of centre of pressure (COP) during walking. We used a video system and a force plate and examined the effects of semi-rigid Air-Stirrup brace, lace-up cloth RocketSoc brace, ankle taping and no bracing. Both the lace-up cloth brace and taping increased the maximum pronation angle during the stance phase. The lace-up cloth brace alone was associated with a larger maximum pronation velocity. With the lace-up cloth brace and taping, the COP was more laterally placed, allowing greater leverage about the subtalar axis and thus increasing the tendency toward pronation. The two braces and the tape did not similarly affect ankle joint biomechanics during gait. The ability to reduce excessive amounts of pronation is an important design consideration for prophylactic ankle supports.

Adult↗
PubMed2002

Tuberculosis of the greater trochanteric bursa occurring 51 years after tuberculous nephritis.

We present a case of tuberculous greater trochanteric bursitis occurring 51 years after tuberculous nephritis in a 71-year-old man. Radiographs of the affected hip revealed focal osteolysis of the greater trochanter and calcification in the surrounding soft tissues. Contrast-enhanced CT scans and MRI revealed that the enlarged bursa extended into the femoral intermuscular spaces. Bacterial culture of the biopsied bursa grew Mycobacterium tuberculosis. Total excision of the infected bursa, combined with antituberculous therapy, was curative. Tuberculosis of the greater trochanteric bursa should be included in the differential diagnosis of chronic hip pain. New tuberculous musculoskeletal lesions can occur elsewhere in the body many years after primary tuberculous lesions have healed.

Aged↗
PubMed2001

Sacral radiculopathy secondary to multicentric osteosarcoma.

STUDY DESIGN: A case of multicentric osteosarcoma presenting with sacral radiculopathy is reported. OBJECTIVE: To present unusual clinical and radiologic findings of multicentric osteosarcoma. SUMMARY OF BACKGROUND DATA: Multicentric osteosarcoma is a rare variant of osteosarcoma. To the authors' knowledge, no cases of multicentric osteosarcoma presenting as sacral radiculopathy have been reported previously. METHODS: A 14-year-old boy had a large sacral tumor extending into the spinal canal, which was found to account for the initial symptoms, which mimicked those of herniated nucleus pulposus. At diagnosis, a bone survey showed multiple foci of osteosarcoma in the long bones. RESULTS: The patient was treated with chemotherapy, but died of the disease 8 months after the initial presentation. CONCLUSION: Multicentric osteosarcoma should be considered in the differential diagnosis for a pediatric patient with low back pain and sciatica.

Adolescent↗
PubMed2001

Influence of macrophage infiltration of herniated disc tissue on the production of matrix metalloproteinases leading to disc resorption.

STUDY DESIGN: Herniated lumbar disc specimens were cocultured with peripheral blood mononuclear cells, and cells isolated from extruded disc were cultured to study the production of matrix metalloproteinases. OBJECTIVE: To investigate the role of peripheral blood mononuclear cells infiltrating extruded discs and disc-derived cells in the production of matrix metalloproteinases. SUMMARY OF BACKGROUND DATA: Magnetic resonance imaging analysis of herniated disc patients revealed a progressive decrease in the size of herniated discs. Spontaneous regression of herniated disc is associated with infiltrating macrophages, and matrix metalloproteinases have been implicated in this phenomenon. However, the correlation between infiltrating macrophages and the production of matrix metalloproteinases has received little research attention. METHODS: Each disc specimen was incubated with homologous peripheral blood mononuclear cells. The numbers of peripheral blood mononuclear cells attached to the surfaces of herniated discs were counted and the culture media was assayed for MMP-3. The cells isolated from herniated discs were incubated with cytokines and the production of matrix metalloproteinases was measured. Total RNA was extracted from herniated discs and RT-PCR was carried out. RESULTS: Significantly larger numbers of peripheral blood mononuclear cells were attached to the surfaces of extruded discs, and higher amounts of MMP-3 were detected than those of control discs. The culture medium of extruded discs showed higher MMP-1 and MMP-3 production than those from controls. Significant enhancement of MMP-1 and MMP-3 mRNA expression was observed in the disc-derived cells stimulated with cytokines. CONCLUSION: These results suggest that peripheral blood mononuclear cells infiltrating extruded discs may secrete a variety of biologic materials capable of further recruiting monocytes into herniated discs in an autocrine fashion. Disc cells stimulated with cytokines showed enhanced production of matrix metalloproteinases, which might play an important role in spontaneous regression of disc materials.

Adult↗
PubMed2001

Contained rupture of the aneurysm of common iliac artery associated with pyogenic vertebral spondylitis.

STUDY DESIGN: A case report. OBJECTIVES: To report and discuss a case of contained rupture of the aneurysm of common iliac artery associated with pyogenic vertebral spondylitis, so that investigators and practitioners may avoid the diagnostic and therapeutic pitfalls associated with pyogenic vertebral spondylitis and aortic disease. SUMMARY OF BACKGROUND DATA: Pyogenic vertebral spondylitis is a rare disorder that may have serious consequences, including death, if it is not diagnosed promptly and treated effectively. The association of pyogenic vertebral spondylitis with infection of the aorta is a rare but potentially fatal condition that requires prompt diagnosis and aggressive surgical and medical therapy. To our knowledge, this is the first report of a contained rupture of the aneurysm of common iliac artery case associated with pyogenic vertebral spondylitis resulting from an infection with Bacteroides fragilis,although Salmonellae infections are commonly associated with vertebral osteomyelitis and lesions of the contiguous aorta. METHODS: A 60-year-old man with chronic lower back pain began to experience a severe pain and had increased difficulty in walking. An MRI scan showed an increased signal in the L4-L5 disc space and an abscess extending into the spinal canal. The presumptive diagnosis was infective spondylitis. While performing a CT-guided needle biopsy, an unexpected contained rupture of the aneurysm of common iliac artery was discovered. RESULTS: A wide resection of all infected tissue, including the right common iliac artery and bony lesions, was performed in combination with antimicrobial therapy. A cryopreserved aortic allograft was used to reconstruct the artery, and an iliac strut graft was used to fill the debrided vertebral cavity. The patient's postoperative recovery was uneventful. CONCLUSION: The coexistence of pyogenic vertebral spondylitis and lesions of the aorta is rare, but may be lethal if not diagnosed promptly and treated effectively. Even if a patient's condition is stable and the hematocrit is normal, it is important to consider the possibility of a contained rupture of a mycotic abdominal aneurysm in all patients with vertebral osteomyelitis who have acute episodes of unusual severe back pain. CT is sometimes more beneficial than MRI in the identification and characterization of contained rupture of aneurysms.

Aneurysm, Ruptured↗
PubMed2001

Recurrent calcified spinal meningioma detected by plain radiograph.

STUDY DESIGN: A case report of a patient presenting with a rare calcified spinal meningioma that recurred and became symptomatic 33 years after initial surgery was performed. OBJECTIVES: To demonstrate a calcified recurrent spinal meningioma visible on a plain radiograph. The present case is discussed in conjunction with a review of previous cases of calcified spinal meningioma. SUMMARY OF BACKGROUND DATA: Meningioma is a common spinal tumor that has a favorable prognosis if resected completely. Microscopic calcification is frequently found in spinal meningiomas because of psammoma bodies. However, calcified meningiomas in the spinal canal that can be detected on a plain radiograph are uncommon. To the authors' knowledge, there have been no previous reports of recurrent spinal meningioma with calcification visible on a plain radiograph. METHODS: A patient experienced difficulty in walking and was diagnosed as having a spinal meningioma. Laminectomies and a total tumor excision were performed. Histologically, the tumor was diagnosed as a psammomatous meningioma. The tumor recurred and became symptomatic 33 years after the initial operation. The tumor was detected on a plain radiograph, appearing as a calcified tumor at the same thoracic level as the site of the initial operation. The recurrent tumor was completely removed, and a histologic examination showed huge psammoma bodies with calcification, but without ossification. RESULTS: Preoperative paraplegia improved after the surgery, and she was able to walk with a crutch. The patient was discharged from the hospital. CONCLUSIONS: The recurrent psammomatous meningioma contained clusters of calcified psammoma bodies, resulting in a hard tumor that was visible on a plain radiograph.

Aged↗
PubMed2001

De novo malignant transformation of giant cell tumor of bone.

Two cases of malignant lesions are reported, both of which arose secondary to an originally benign giant cell tumor (GCT) of bone. The first case was a typical benign GCT, which occurred in the left proximal tibia of a 31-year-old woman. The tumor was treated by curettage and bone grafting. However, it recurred twice during 15 years of follow-up. The second recurrence showed that the lesion histologically had turned into malignant fibrous histiocytoma. The second case also started as an initially benign GCT that arose in the left distal femur of a 41-year-old man. The patient underwent curettage and bone grafting. The lesion recurred 13 years postoperatively. The histological appearance of the recurrent tumor showed it to be an osteogenic sarcoma. In both patients, radiation and never been given. Malignant transformation has rarely been reported in patients with GCT of bone who have not received radiation treatment.

Adult↗