Biomedical subjects

Toshihide Shuto

Publications and source records attributed to Toshihide Shuto.

11 recordsLinked to original sources

PubMed2006

Subchondral insufficiency fracture of the femoral head in younger adults.

We report two cases of subchondral insufficiency fracture of the femoral head observed in younger adults without any history of overexertion. In both cases, MRI revealed an irregular, discontinuous low-intensity band on the T1-weighted images. Both patients were treated operatively, and histological examination confirmed the diagnosis of subchondral fracture. A diagnosis of subchondral insufficiency fracture needs to be put in as one of the diagnoses in younger patients with a hip pain.

Adult↗

PubMed2006

Outcome of the contralateral hip in rapidly destructive arthrosis after total hip arthroplasty: a preliminary report.

We investigated the outcome of the contralateral hip in patients with rapidly destructive arthrosis of the hip after total hip arthroplasty. Twenty-four patients were included, and the mean duration of radiographic follow-up was 7.0 years (range, 3.8-17.8 years). To assess the capable parameters for predicting the development of osteoarthritis, we evaluated the receiver operating characteristic curves. Three (12.5%) of 24 patients developed osteoarthritis and underwent total hip arthroplasty within 3.8 to 6.5 years. In these 3 patients, both the acetabular-head index and the center-edge angle were significantly lower than those in patients without osteoarthritis (P < .005). Based on the receiver operating characteristic curves, both an acetabular-head index of less than 72% and a center-edge angle of less than 16 degrees were considered to be associated with the development of osteoarthritis.

Acetabulum↗

PubMed2005

Early MRI findings of the acetabulum and femoral head in a dysplastic hip resulting in a rapid destruction of the hip joint.

We documented a case of rapidly destructive arthrosis of the hip joint (RDA), in whom abnormal findings were observed not only in the femoral head but also in the acetabulum on magnetic resonance images (MRI) in the early stage. Radiographs made 1 month after the onset of pain showed a slight narrowing of the joint space. MRI obtained 2 months after the onset detected small foci of low signal intensity in the subchondral area of the femoral head on the T1-weighted images, and a linear pattern of high signal intensity in the lateral side of the acetabulum on the T2-weighted images. During the 17-month follow-up period, this case eventually underwent massive destruction of the femoral head as well as the acetabulum.

Acetabulum↗

PubMed2005

The protective effects of incadronate on inflammation and joint destruction in established rat adjuvant arthritis.

The effects of a new generation bisphosphonate, incadronate, in established adjuvant arthritis rats were evaluated according to the arthritis index, hind paw volume, and radiological and histopathological examinations. Incadronate suppressed the radiological and histopathological changes of hind paws, as well as the joint swelling in a dose-dependent manner. In contrast, the arthritis control rats showed drastic joint inflammation, marked destruction of bone and articular cartilage. The remains of articular cartilage lost Safranin O staining, and were attached with numerous TRAP-positive multinuclear cells. Some of resorption lacunas could be seen at the cartilage matrix nearby the TRAP-positive multinuclear cells. As regards the chondroprotective effects of bisphosphonates, we speculate that it is probably concerned with the inhibition of the chondroclasts. These data indicate that bisphosphonates may be a class of effective agent that can be considered for treatment of various arthritic conditions, including human rheumatoid arthritis.

Animals↗

PubMed2005

Bilateral subchondral insufficiency fracture of the femoral head after renal transplantation: a case report.

This report describes the case of a 47-year-old woman who was found to have subchondral insufficiency fractures in both femoral heads after renal transplantation. Initially, plain radiographs showed no obvious changes, but magnetic resonance imaging (MRI) revealed an irregular, discontinuous, low-intensity band on the T1-weighted image of both hips. The patient was treated nonsurgically. Ten months after onset, the pain in both hips disappeared, and plain radiographs and MRI showed no abnormalities. Subchondral insufficiency fracture should be considered in the diagnosis of patients who have hip pain after renal transplantation.

Diagnosis, Differential↗

PubMed2004

Atlantoaxial instability in neck retraction and protrusion positions in patients with rheumatoid arthritis.

STUDY DESIGN: Radiographic analysis of the upper cervical spine was performed in patients with rheumatoid arthritis who had C1-C2 instability. OBJECTIVE: To assess whether neck retraction or neck protrusion movements can cause C1-C2 subluxation in patients with C1-C2 instability. SUMMARY OF BACKGROUND DATA: Cervical protrusion is the position where the head is maximally translated anteriorly with zero sagittal rotation, and this position has been shown to produce maximal C1-C2 extension. In contrast, cervical retraction is the position where the head is maximally translated posteriorly, and this position produces maximal C1-C2 flexion. To date, there have been no studies evaluating the effects of these two positions on C1-C2 status in patients with C1-C2 instability. METHODS: Twenty-four patients with rheumatoid arthritis who showed an atlantodental interval of at least 5 mm during neck flexion were evaluated in this study. These patients were instructed to actively hold the neck in protrusion and retraction positions, as well as in flexion and extension positions. Lateral cervical radiographs were taken to measure the C1-C2 angle and the atlantodental interval in the sagittal plane in each position. RESULTS: Retraction produced both maximal C1-C2 flexion and anterior C1-C2 subluxation, of a degree just the same as that produced by cervical flexion. Protrusion reversely produced maximal C1-C2 extension. However, 9 of 24 patients exhibited C1-C2 subluxation even in this protrusion position, in marked contrast to the cervical extension position in which only 2 of 24 patients showed C1-C2 subluxation. The patients who showed C1-C2 subluxation in the protrusion position tended to have more severe C1-C2 instability and less capacity for C1-C2 extension than the other patients who achieved a reduction of C1-C2 in the protrusion position. CONCLUSION: In patients with C1-C2 instability, not only cervical flexion but also cervical retraction constantly led to both maximal C1-C2 flexion and subluxation. In some patients with severe C1-C2 instability, protrusion also resulted in C1-C2 subluxation, even though the C1-C2 was maximally extended.

Adult↗

PubMed2004

[Bone quantity and quality to its mechanical integrity].

Bone strength is made up of quantity (mass, mineralization), geometry (anatomy, micro architecture, collagen structure), and turnover/damage accumulation. While most of the mechanical behavior can be explained by measures of porosity, several additional descriptors of the geometry have been proposed for better predictions of fracture risk. This review introduces various aspects of these relationships between bone quantity and quality to its mechanical integrity.

Biomechanical Phenomena↗

PubMed2003

Antiinflammatory and chondroprotective effects of the aminobisphosphonate incadronate (YM175) in adjuvant induced arthritis.

OBJECTIVE: Incadronate is a third-generation bisphosphonate that suppresses bone resorption and is used to treat skeletal disorders and prevent bone loss in pathological conditions. We evaluated its therapeutic potential and antiinflammatory effects in established adjuvant induced arthritis (AIA), a rat model of rheumatoid arthritis (RA). METHODS: Rats were administered incadronate subcutaneously at a dose of either 0.1 or 1.0 mg/kg/day, or 0.1 or 1.0 mg/kg/week, while a positive control group received phosphate buffered saline alone from Day 14 (after the onset of arthritis) to Day 42. The destruction of bone and cartilage and the antiinflammatory effects of incadronate in rats with established AIA were assessed during treatment, with reference to the arthritis index, hind paw volume, and radiological and histological examinations. To establish whether incadronate affects the migration of inflammatory cells, a chemotaxis assay was carried out using macrophage-like RAW 264.7 cells. Results. In vivo, incadronate suppressed the clinical manifestations of AIA in a dose-dependent manner. In vitro, the various concentrations of incadronate suppressed the migration of macrophages, but the viability and adhesion of these cells were not suppressed. CONCLUSION: Incadronate not only inhibits bone destruction but also reduces cartilage degeneration and joint inflammation in rats with established AIA. The mechanism underlying these antiinflammatory actions of incadronate may be attributable to the inhibition of macrophage migration to the site of inflammation. Bisphosphonates might be effective in preventing the progressive joint destruction and inflammation seen in patients with RA.

Animals↗

PubMed2002

Possible involvement of the vascular endothelial growth factor-Flt-1-focal adhesion kinase pathway in chemotaxis and the cell proliferation of osteoclast precursor cells in arthritic joints.

Vascular endothelial growth factor (VEGF) plays a crucial role in the pathogenesis of inflammatory joint disease, including angiogenesis and synovitis. Rheumatoid arthritis is a chronic inflammatory disease characterized by progressive synovitis and subsequent bone destruction mediated by osteoclasts (OCs). In this study, we investigate the effects of VEGF on OC precursor cells (pOCs) using Raw cells and adjuvant-induced arthritis in rats. OCs and pOCs in the arthritic joints express VEGF and VEGF receptor type I (Flt-1). Raw cells also express Flt-1, and VEGF treatment stimulated chemotaxis, cell proliferation, the association of Flt-1 with focal adhesion kinase (FAK), and the tyrosine phosphorylation of FAK in Raw cells. The tyrosine phosphorylation of FAK was also observed in pOCs in the arthritic joints of adjuvant-induced arthritis. Adenovirus-mediated expression of FAK-related nonkinase in Raw cells inhibited the effects of VEGF in a dominant negative manner. Furthermore, intra-articular injection of the FAK-related nonkinase virus suppressed the recruitment of pOCs and bone destruction. Our results suggest the possible involvement of the VEGF-Flt-1-FAK pathway in inflammatory disease-induced joint destruction.

Animals↗

PubMed2002

Involvement of CD4+,CD57+ T cells in the disease activity of rheumatoid arthritis.

OBJECTIVE: To evaluate the relationship between the frequency of peripheral CD57+ T cells and the physical status of rheumatoid arthritis (RA) patients, and to perform cytokine analysis of these CD57+ T cells. METHODS: Four-color fluorescence-activated cell sorter analysis was performed to detect both cell surface antigens and intracellular cytokines in peripheral blood leukocytes, using monoclonal antibodies against CD3, CD4, CD8, CD57, interferon-gamma (IFNgamma), and interleukin-4 (IL-4). RA patients were clinically evaluated with a modified Health Assessment Questionnaire (M-HAQ), joint score, face scale, and visual analog scale (VAS) assessing pain and disease activity. RESULTS: There was a significant correlation between the frequency of CD4+,CD57+ T cells and erythrocyte sedimentation rate (ESR), whereas a correlation was not found between the frequency of CD8+,CD57+ T cells and ESR. The frequency of CD4+,CD57+ T cells also showed a significant correlation with the mHAQ score, VAS, and face scale. Again, there was no significant correlation between the above-mentioned clinical scores and the frequency of CD8+,CD57+ T cells. Flow cytometric analysis of intracellular cytokines revealed that 14.5% of the CD57+ T cells produced IFNgamma, whereas only 2.8% of the CD57+ T cells produced IL-4 in RA patients. CONCLUSION: Evidence showing that the frequency of CD4+,CD57+ T cells among CD3+ cells of RA patients had a significant correlation not only with ESR but also with the physical status of the patients, and that a large proportion of the CD4+,CD57+ T cells had the capacity to produce IFNgamma, strongly suggests that these CD4+,CD57+ T cells are involved in the immunopathogenesis of RA.

Adult↗

PubMed2002

Relationship between the maximum flexion-internal rotation test and the torn acetabular labrum of a dysplastic hip.

To determine the relationship between pain at flexion-rotation and the status of a labral tear in patients with dysplastic hips, physical examination maneuvers and hip arthroscopy were carried out in 59 patients with dysplastic osteoarthritis (5 men and 54 women; mean age, 41 years; range, 16 to 64 years). Between January 1998 and June 2000, these patients underwent 60 hip arthroscopies at Kyushu University Hospital. All hip joints arthroscoped demonstrated incomplete or complete detaching tears of the acetabular labrum in one portion of the weight-bearing area. Twenty-three patients (39%) experienced pain during the maximum flexion-internal rotation test; 16 patients (27%) showed a positive result for the maximum flexion-external rotation test. There was no statistically significant relationship between the results of the maximum flexion-external rotation test and the arthroscopic findings of labral tears. A positive maximum flexion-internal rotation test result, however, correlated well with incomplete detaching tears in the posterosuperior portion of the acetabular labrum. In contrast, a complete detaching tear of the posterosuperior labrum was associated with a negative maximum flexion-internal rotation test result. The maximum flexion-internal rotation test is useful for assessing the magnitude of a labral tear in the posterosuperior portion of the acetabular labrum in dysplastic hips.

Acetabulum↗