Biomedical subjects

Yasuharu Nakashima

Publications and source records attributed to Yasuharu Nakashima.

10 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

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↗

PubMed2005

Postpartum retroperitoneal fasciitis: a case report and review of literature.

We present a case of a postpartum female with iliopsoas fasciitis in the puerperium. Two days after a spontaneous vaginal delivery at 38 weeks without any complications, the patient complained of pain in the left thigh and hip, associated with a temperature of 38 degrees C. Consequently, she could not walk 4 days after delivery and her body temperature had increased to 39 degrees C. Extreme left flank pain and tenderness in the left pelvic wall were prominent, whereas the tenderness in the pelvis was moderate. Magnetic resonance imaging led us to diagnose iliopsoas fasciitis. This was complicated by sepsis but improved after a protracted antibiotic treatment without any surgical intervention. A literature review revealed that serious complications, including sepsis or permanent functional disturbance, could arise although retroperitoneal fasciitis and/or abscesses are very rare after vaginal delivery. Iliopsoas fasciitis could be considered when patients complain of extreme pain in the pelvic wall, sacroiliac joint region, or thigh-symptoms that are uncommon in uncomplicated endometritis.

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

Human serum opsonization of orthopedic biomaterial particles: protein-binding and monocyte/macrophage activation in vitro.

Wear particles generated after total joint arthroplasty activate monocyte/macrophages and incite formation of a granulomatous periprosthetic tissue associated with bone loss and implant loosening. This study tested the hypothesis that selective opsonization of orthopedic implant biomaterial wear particles by human serum proteins influences monocyte/macrophage activation. Serum protein binding to metallic, polymeric, and ceramic particles was determined by one-dimensional sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Individual proteins bound to particles were subsequently identified using two-dimensional SDS-PAGE, microsequencing techniques, and SWISS-PROT analysis. Effects of selective protein opsonization on particle-induced monocyte/macrophage activation were assessed by quantification of interleukin-1beta, interleukin-6, and tumor necrosis factor-alpha release. Results from one-dimensional gel analyses revealed distinct serum protein-binding patterns specific for each material tested. Two-dimensional gel analysis together with amino acid sequencing of the prominent protein species confirmed the presence of albumin and alpha-1-antitrypsin bound to all particles tested. In contrast to the metallic particles, apolipoprotein was a major species associated with polymeric particles. Opsonization of PMMA particles with purified preparations of each of the identified proteins showed that albumin significantly enhanced particle-induced monocyte/macrophage activation. These data confirm orthopedic biomaterial specific binding of human serum proteins and demonstrate that albumin exacerbates particle-induced monocyte/macrophage activation. Alterations in the chemical and surface properties of orthopedic biomaterials to modulate protein interactions may improve implant longevity.

Biocompatible Materials↗

PubMed2003

Correlation between center-edge angle and acetabulum-head index in developmental dysplasia of the hip with avascular necrosis of the femoral head.

In order to clarify the relationship between the center-edge angle and the acetabulum-head index, we reviewed 97 hips in 86 patients suffering from developmental dysplasia of the hip. We measured the center edge angle and the acetabulum-head index, and evaluated avascular necrosis of the femoral head according to Kalamchi classification. The center-edge angle correlated highly with the acetabulum-head index in non-avascular necrosis, and in Kalamchi groups I and II, but not in Kalamchi groups III and IV. Because of difficulties in measurement, it is possible that the center-edge angle does not precisely indicate acetabular coverage of developmental dysplasia of the hip with avascular necrosis.

Acetabulum↗

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↗