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Biomedical subjects

S Yoshiya

Publications and source records attributed to S Yoshiya.

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

A prospective comparison of clamping the drain or post-operative salvage of blood in reducing blood loss after total knee arthroplasty.

We undertook a prospective, randomised study in order to evaluate the efficacy of clamping the drains after intra-articular injection of saline with 1:500 000 adrenaline compared with post-operative blood salvage in reducing blood loss in 212 total knee arthroplasties. The mean post-operative drained blood volume after drain clamping was 352.1 ml compared to 662.3 ml after blood salvage (p < 0.0001). Allogenic blood transfusion was needed in one patient in the drain group and for three in the blood salvage group. Drain clamping with intra-articular injection of saline with adrenaline is more effective than post-operative autologous blood transfusion in reducing blood loss during total knee arthroplasty.

Aged↗
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↗
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↗
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↗
PubMed2000

Expression of a bioactive bovine interleukin-12 using baculovirus.

Recombinant baculoviruses that express recombinant bovine interleukin-12 (rboIL-12) subunits, p35 and p40 subunits were constructed. A recombinant virus containing the p40 subunit gene expressed the p40 subunit as a 40kDa monomer and an 80kDa disulfide-linked homodimer in the infected insect cells and in the culture supernatant. The p35 subunit was expressed in a 30kDa monomer in the infected cells but not in the supernatant. Superinfection of both recombinant viruses into the cells in a spinner flask resulted in the formation of a 70kDa disulfide-bonded heterodimer detected in the supernatant by immunoblotting using anti-p40 and anti-p35 subunits antibodies. The superinfected culture supernatant showed induction of IFNgamma mRNA synthesis and IFNgamma production in bovine peripheral blood mononuclear cells. Thus, the bioactive rboIL-12 was produced in large scale using a baculovirus expression system.

Animals↗
PubMed2000

Localization of growth factors in the reconstructed anterior cruciate ligament: immunohistological study in dogs.

This study was designed to examine localization of the growth factors in the autogenous patellar tendon graft used to reconstruct the anterior cruciate ligament (ACL) in the canine model. Among the various growth factors, basic fibroblast growth factor, transforming growth factor-beta1, and platelet-derived growth factor were selected for analysis as potential factors that regulate graft remodeling processes. In the control patellar tendon and the ACL only basic fibroblast growth factor was positively stained. In the reconstructed graft increased levels of staining for all the three factors were observed in the early postoperative period, reaching the greatest expression 3 weeks after implantation. Thereafter immunoreactivity of these growth factors decreased and returned to the preoperative levels, which were similar to that of the control ACL 12 weeks postoperatively. This rapid reduction in the level of their localization indicates that once the extrinsic cells are infiltrated to the graft and revascularization completed, these growth factors may have less significance for subsequent remodeling.

Animals↗
PubMed2000

Graft healing in the bone tunnel in anterior cruciate ligament reconstruction.

The histologic sequence in the bone tunnel after anterior cruciate ligament reconstruction using the bone-patellar tendon-bone graft was investigated in this study. Eighteen adult mongrel dogs were used. After excision of the anterior cruciate ligament, the graft was routed through the bone tunnels and fixed with interference fit screws. After the dogs were sacrificed at intervals, the bone blocks containing the bone tunnels were isolated and processed for histologic examination. At the bone-bone interface, incorporation of the bone plug at each end of the graft was completed at 12 weeks. The structure of the tendon insertion of the grafted patellar tendon, consisting of four distinct zones, was observed without apparent necrotic and degenerative change for as long as 12 weeks. Between the tendon and the bone tunnel, a layer of hypercellular fibrous tissue gradually became mature with time. Thus, it appeared the morphologic characteristics and location of the reestablished attachment of the bone-patellar tendon-bone graft were more similar to those of the native anterior cruciate ligament compared with the graft to bone healing in the hamstring tendon graft.

Animals↗
PubMed2000

Radiographic and computed tomographic analysis of the position of the tibial tubercle in recurrent dislocation and subluxation of the patella.

Among the factors that influence the patellofemoral alignment and stability, the position of the tibial tubercle was evaluated using plain radiographs and computed tomography (CT). Radiographs of the Q-angle with the knee in full extension and quadriceps muscle relaxed showed that mean Q-angles in the dislocation or subluxation group and control group were 13.8 degrees and 14.3 degrees, respectively. The major reason for this deceptive measurement was a patella positioned laterally in the dislocation or subluxation group. Better estimation was made with the modified Q-angle measurement by using the most concave point of the intercondylar notch as a reference point instead of the center of the patella. By overshadowing CT images of the levels of the patellofemoral joint and the tibial tubercle, it was possible to evaluate the location of the tibial tubercle in relation to the femoral trochlea. Both the angular measurement (lateral deviation angle [LDA]) and the distance measurement (lateral deviation index [LDI]) showed that the tibial tubercle in the dislocation or subluxation group was rotated externally and shifted laterally (LDA, 36.3+/-7.0 degrees and LDI, 30.1+/-5.6) compared with the control group (LDA, 20.2+/-7.1 degrees and LDI, 15.1+/-5.6). Further study is warranted to elucidate the exact mechanism of recurrent patellar dislocation and subluxation.

Adult↗
PubMed1999

Efficacy of the axially loaded pivot shift test for the diagnosis of a meniscal tear.

Although magnetic resonance imaging (MRI) has improved the diagnostic accuracy of meniscal pathology, the authors believe that physical examination remains essential to the evaluation of knee pathology. In this study, the diagnostic accuracy of five clinical tests for meniscal pathology was prospectively evaluated in 160 patients, who thereafter underwent arthroscopy. 69% (109 knees) of the knees tested had associated ACL deficiency. There were 144 meniscal lesions in 130 of the 160 knees which were examined. The sensitivity of the tests was lower than the specificity. Conventional tests such as McMurray and Apley tests showed a low accuracy rate of 45% and 28% respectively. The diagnostic value of the axially loaded pivot shift test was significantly higher, indicating that this remains a useful diagnostic aid.

Adolescent↗
PubMed1998

Evaluation of functional deficits determined by four different hop tests in patients with anterior cruciate ligament deficiency.

The purpose of this study was to analyze the validity of the newly designed functional ability test (FAT) for the normal population and patients with deficiency of the anterior cruciate ligament (ACL). The FAT consists of four tests: the figure-of-eight hop, the up-down hop, the side hop, and the single hop. Sixty control subjects and 50 patients with unilateral ACL deficiency were tested. In the control group, the values measured were significantly different between males and females in all of the tests. On the other hand, when left/right difference values were compared, no significant difference was found between males and females in any of the tests. More than 95% of control group exhibited symmetrical function in each part of the FAT, whereas in the ACL-deficient group, the percentage of patients who showed abnormal symmetry was 68% in the figure-of-eight hop, 58% in the up-down hop, 44% in the side hop, and 42% in the single hop. The percentage of ACL-deficient patients with functional asymmetry in at least one of the four tests was 82%. The FAT was found to be useful in evaluating lower limb function in ACL-deficient patients.

Adolescent↗