PubMed Health⌕ Search

Biomedical subjects

Shinichi Yoshiya

Publications and source records attributed to Shinichi Yoshiya.

At least 37 records · Page 2Linked to original sources
PubMed2005

Total hip arthroplasty in severe congenital factor VII deficiency: successful use of recombinant activated factor VII for hemostasis.

Congenital factor VII (FVII) deficiency is a rare hemorrhagic disorder, and, in affected patients, surgery is likely to cause excessive bleeding. In this article, we report the first case of total hip arthroplasty in a patient with severe congenital FVII deficiency in which recombinant activated factor VII (rFVIIa, NovoSeven) was successfully used to manage bleeds. The patient was a 68-year-old woman with severe congenital FVII deficiency, who suffered from a hemorrhagic arthrosis of her left hip joint. We administered rFVIIa as intermittent bolus infusions both perioperatively and postoperatively; dosing was based on the results of a preoperative rFVIIa challenge test. During surgery and the 3-day postoperative treatment period, we observed normal hemostasis with no excessive bleeding or complications.

Aged↗
PubMed2005

In vivo kinematic comparison of posterior cruciate-retaining and posterior stabilized total knee arthroplasties under passive and weight-bearing conditions.

An in vivo comparison of flexion kinematics for posterior cruciate-retaining (PCR) and posterior stabilized (PS) total knee arthroplasty (TKA) was performed. Twenty patients who underwent bilateral paired TKAs were included in this prospective study. Both PCR and PS prostheses were from the same TKA series with comparable surface geometries, and all were implanted by a single surgeon. Of these 20 patients, 3-dimensional kinematics during flexion could be analyzed using a computer model fitting technique in 18 patients. The follow-up period ranged from 18 to 53 months. In the PCR TKA, an anterior femoral translation from 30 degrees to 60 degrees of flexion was observed in the weight-bearing condition. In contrast, flexion kinematics for the PS TKA was characterized by the maintenance of a constant contact position under weight-bearing conditions and posterior femoral rollback in passive flexion.

Aged↗
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

Symptomatic anomalous insertion of the medial meniscus.

We report a case of a young athlete with a symptomatic anomaly of the medial meniscus. An anomalous portion in conjunction with the anterior horn of the medial meniscus extended to the intercondylar notch of the femur through the surface of the anterior cruciate ligament. This anomalous band was arthroscopically resected and the symptoms completely disappeared. Histologic examination showed fibrocartilaginous tissue compatible with meniscus.

Adolescent↗
PubMed2005

Impaction bone grafting with hydroxyapatite: increased femoral component stability in experiments using Sawbones.

BACKGROUND: Substantial bone loss and bone defects increase the amount of allografting required in hip revision surgery. Thus, the use of a synthetic material to limit the amount of allograft tissue required for impaction grafting is desirable. We evaluated the potential of hydroxyapatite (HA) mixtures to provide initial mechanical stability to a polished tapered femoral stem. MATERIAL AND METHODS: We determined the initial stability of a polished tapered femoral stem after reconstructing a cavitary femoral bone defect by impaction bone grafting with cement in Sawbones composite femurs. Three types of graft material were tested for their ability to improve initial rotational stability. The graft materials investigated were pure allograft, a mixture of 50% allograft and 50% hydroxyapatite (HA), and pure HA. RESULTS: We found a statistically significant difference between the three groups as regards torsional micromotion and failure load. INTERPRETATION: Our findings suggest that reconstruction of femoral bone defects with pure HA or a mixture of allograft and HA provides adequate initial stability for femoral revision arthroplasty using impaction grafting.

Arthroplasty, Replacement, Hip↗
PubMed2005

A posterior-stabilized total knee arthroplasty shows condylar lift-off during deep knee bends.

This prospective randomized study was done to examine whether any difference in presentation of condyler lift-off exists between posterior cruciate-retaining and posterior-stabilized total knee arthroplasties. Fluoroscopic analysis of flexion kinematics under weightbearing condition was done for 18 patients who had bilateral paired total knee arthroplasties. The posterior cruciate-retaining and posterior-stabilized prostheses were from the same total knee arthroplasty series with comparable surface geometries and were implanted by one surgeon. At evaluation, five of 18 patients (28%) with posterior cruciate-retaining total knee arthroplasties had condylar lift-off, compared with 12 of 18 patients (67%) with posterior-stabilized total knee arthroplasties. Consequently, a significant difference in its incidence was seen between the groups. Condylar lift-off in posterior-stabilized knees was observed at various flexion angles, and one knee in this group had lift-off laterally and medially at different flexion angles. These findings raise concern that the higher incidence of condylar lift-off in posterior-stabilized total knee arthroplasty may lead to an increased wear rate of polyethylene associated with long-term prosthetic loosening.

Aged↗
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↗
PubMed2005

Giant-cell tumor of the tendon sheath involving the thoracic spine.

Giant-cell tumor of the tendon sheath is a common benign lesion of the synovial membrane that frequently occurs in the hand. It is related to pigmented villonodular synovitis and the occurrence of pigmented villonodular synovitis or giant-cell tumor of the tendon sheath in the axial skeleton is very rare. To data, only three cases of giant-cell tumor of the tendon sheath involving cervical spine have been reported, compared with 26 cases of pigmented villonodular synovitis. Pigmented villonodular synovitis involving the thoracic spine is also extremely rare and our case represents the first reported case of a giant-cell tumor of the tendon sheath involving the thoracic spine. A 26-year-old man presented with left back pain without neurological deficit. Computed tomography and magnetic resonance imaging (MRI) revealed an osteolytic and expansive lesion in the left facet joint between the seventh and eighth thoracic vertebrae. A complete facetectomy and excision of the lesion followed by a posterior arthrodesis between Th5 and Th9 was performed. Postoperatively, the patient recovered with complete relief of symptoms, there was no evidence of recurrent disease or regrowth of the residual lesion, as investigated by plain radiographs and MRI within a follow-up period of two years. Although giant-cell tumor of the tendon sheath in the thoracic spine may be extremely uncommon, it should be considered in the differential diagnosis, especially when a benign lesion appears to originate in the face joint. Considering the high rate of recurrence, every effort should be made to achieve total excision.

Adult↗
PubMed2005

Lumbar facet joint infection associated with epidural and paraspinal abscess: a case report with review of the literature.

A case of lumbar facet joint infection associated with epidural and paraspinal abscess is presented. A 57-year-old man was hospitalized with severe low back pain that radiated into the bilateral buttocks and legs. The patient had a temperature of 37.3 degrees C, and the biochemical inflammatory parameters were elevated. Initially on admission, we administered antibiotics intravenously. However, pain increased, fever elevated gradually, and bladder-bowel disturbance appeared. Magnetic resonance imaging (MRI) showed effusion in the widened facet joint, paraspinal muscles, and epidural space, which compressed the theca severely. We performed an immediate surgical debridement combined with thorough antibiotic therapy and achieved excellent results. MRI was useful for precise diagnosis and operative planning.

Epidural Abscess↗
PubMed2005

Musculoskeletal conditions of acute leukemia and malignant lymphoma in children.

We retrospectively reviewed 16 patients who presented to hospitals with orthopaedic complaints. Twelve patients experienced initial symptoms in the extremities and four patients had back pain. The leukocyte count was elevated in one patient, decreased in two patients, and normal in 13 patients. On radiographic examination, osteopenia was observed in 10 patients, osteolytic lesions were observed in five, and pathologic fractures were observed in five. Because the initial presentation of patients with leukemia often involves the musculoskeletal system, orthopaedists need to recognize the symptoms of this disease to avoid misdiagnosis and to expedite the initiation of appropriate potentially lifesaving treatment.

Bone Diseases, Metabolic↗
PubMed2005

Establishment and characterization of a KIT-positive and stem cell factor-producing cell line, KTHOS, derived from human osteosarcoma.

Osteosarcoma is a malignant bone tumor that commonly affects adolescents and young adults. In the present study a human osteosarcoma cell line, KTHOS, was established from a primary osteosarcoma lesion in the distal femur of a 16-year-old girl. After 106 passages, the KTHOS cell line retained the biological characteristics of osteosarcoma. The KTHOS cells had spindle to pleomorphic cytoplasm with round to ovoid nuclei containing multiple prominent nucleoli, as expected based on the mesodermic origin of osteoblasts. The KTHOS cells were immunoreactive for osteocalcin, osteonectin, stem cell factor (SCF), and KIT (CD117). Reverse transcriptase-polymerase chain reaction indicated that the KTHOS cell line expressed mRNA for SCF and KIT. The KTHOS cells produced relatively high amounts of soluble SCF as determined by enzyme-linked immunosorbent assay. The results suggest that cell proliferation of the KTHOS cell line might be involved in autocrine and/or paracrine loops of the SCF/KIT signaling system. The KTHOS cell line is a novel human osteosarcoma cell line that releases SCF and expresses KIT. This cell line can be used for studies to explore the mechanisms for oncogenesis of human osteosarcomas.

Adolescent↗
PubMed2005

Heat shock protein 90 is required for increased DNA binding activity of activator protein-1, a heterodimer of Fos/JunD, in rheumatoid synovial cells under inflammatory stimuli.

We have studied the DNA binding profiles of activator protein-1 (AP-1) involved in synovial overgrowth and osteoporosis in rheumatoid arthritis (RA) in relation to the molecular chaperon heat shock protein 90 (HSP90). The AP-1 binding activity of the nuclear extracts of rheumatoid synovial cells was basically increased as compared with osteoarthritic synovial cells. Upon stimulation with inflammatory cytokines IL-1beta or TNFalpha, the AP-1 binding activity was further increased in rheumatoid synovial cells, and increased AP-1 protein was composed as heterodimers of Fos and JunD which was not known before as a major component of AP-1 in rheumatoid synovial cells. The increase of AP-1 binding activity as induced by inflammatory cytokines was specifically inhibited by geldanamycin, radicicol or herbimycin A, specific inhibitors of HSP90, while AP-1 protein was not decreased by geldanamycin. Further, HSP90 protein was not decreased by the inhibitors. The findings indicate that HSP90 is required for increased AP-1 binding activity of rheumatoid synovial cells under inflammatory stimuli and that AP-1 binding activity is inhibited by functionally inactivating HSP90 with the inhibitors.

Arthritis, Rheumatoid↗
PubMed2005

Estrogen specifically stimulates expression and production of osteoprotegerin from rheumatoid synovial fibroblasts.

We studied the effects of estrogen on human fibroblast-like synovial cells in rheumatoid arthritis (RA-FLS) focusing on receptor activator of NF-kappaB ligand (RANKL) and its decoy receptor osteoprotegerin (OPG), the osteoclast formation and function regulators that have a substantial role in bone erosion of RA. Estrogen influences osteoporosis and the onset of RA clinically. The cellular responses of RA-FLS to estrogen are initiated via two high-affinity estrogen receptors (ERs). Culture of RA-FLS in the presence of 10(-6) M 17beta-estradiol (E2) increased expression of estrogen receptor (ER)-alpha, but not ER-beta. OPG mRNA expression was significantly increased, whereas RANKL mRNA was unaffected. E2 treatment also significantly increased the amount of OPG released in the culture supernatant. The increase of OPG and ER-alpha was specifically antagonized by the pure estrogen antagonist ICI 182780. Tamoxifen, a selective ER moderator, did not increase OPG. The results indicate that estrogen stimulates secretion of OPG from RA-FLS by acting on ER-alpha, which likely prevents bone erosion in RA.

Arthritis, Rheumatoid↗
PubMed2004

The load of an implanted graft during and after fixation in anterior cruciate ligament reconstruction.

Although the importance of initial graft load has been discussed in the literature, it has not been confirmed whether a surgeon can provide the desired load to an implanted graft in anterior cruciate ligament reconstruction. The purpose of this study was to compare the set force (initial load given to the graft before fixation) and residual load in the implanted graft using three different fixation techniques. A total of ninety porcine knees were tested using bone-patellar tendon-bone autograft. Each bone-tendon-bone autograft was fixed to the tibia with either the interference-fit screw, fixation post, or button technique. Graft load was monitored during fixation procedures, and for 10 min after fixation. Residual graft load with each fixation technique exhibited unique features. Highest graft load was obtained by the interference-screw fixation technique; however, the graft was usually over-loaded beyond the intended set force with this technique. In the fixation-post technique, the load of the graft increased while the screw was retightened. The graft load in the button-fixation technique was low, probably due to slight slippage of the button. When the graft was fixed under maximum manual tension, the graft loads at completion of fixation for the interference fit screw, fixation post, and button techniques were 116.3, 54.2, and 25.9 N respectively.

Animals↗
PubMed2004

Fas-ligand expression on nucleus pulposus begins in developing embryo.

STUDY DESIGN: The expression of Fas ligand in the notochord or nucleus pulposus was examined immunohistochemically using rat embryos. OBJECTIVE: To clarify at which stage of embryo development the expression of Fas ligand begins in the nucleus pulposus. SUMMARY OF BACKGROUND DATA: The nucleus pulposus has been reported to be an immune-privileged site. Immune-privileged characteristics in other tissues, such as the retina and testis, have been attributed to the local expression of Fas ligand, which acts by inducing apoptosis of invading Fas-positive T cells. The authors reported previously on the expression of Fas ligand in nucleus pulposus cells of mature rats and humans, which could play a key role in the potential molecular mechanism of maintaining immune privilege of the disc. However, it is unknown at which stage of the developing embryo Fas ligand expression begins in the nucleus pulposus. METHODS: Female adult Sprague-Dawley rats were housed with males for one night and monitored the next morning for the appearance of a vaginal plug. Later, whole sequential embryos were dissected and fixed immediately. Immunohistochemical staining for Fas ligand was performed for sagittal sections of notochords or nucleus pulposus using standard procedures. The sections were observed using light microscopy. RESULTS: In the 14.5-day-old embryo, the notochord appeared as a continuous structure with a uniform diameter, and there was no positive staining for Fas ligand. In the 16.5-day-old embryo, the notochord became compressed at the centers of the vertebral bodies and expanded in the presumptive nucleus pulposus areas. At this stage, some of the nucleus pulposus cells exhibited weak positive staining for Fas ligand. In the 18.5-day-old embryo, the nucleus pulposus enlarged in fusiform, and most of the nucleus pulposus cells exhibited intense positive staining for Fas ligand. CONCLUSIONS: The present results demonstrated that Fas ligand expression is not detected in the notochord, but at the time of intervertebral disc formation, Fas ligand expression develops in the nucleus pulposus. These results indicate that the immune privilege of the intervertebral disc may begin in the very early stages of disc formation. Moreover, Fas ligand may play an important role in the formation of the intervertebral disc.

Animals↗
PubMed2004

Spontaneous rupture of the extensor pollicis longus tendon in a professional skier.

Spontaneous rupture of the extensor pollicis longus (EPL) tendon is uncommon in sports activities. We report a rare case of a professional downhill skier presenting with a rupture of the EPL tendon. Repetitive motion of the wrist joint appeared to cause the rupture. The patient was treated successfully with tendon transfer of the extensor indicis proprius.

Adult↗