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Biomedical subjects

E Itoi

Publications and source records attributed to E Itoi.

At least 19 recordsLinked to original sources
PubMed2006

Dedifferentiated chondrosarcoma with telangiectatic osteosarcoma-like features.

A 35-year-old Japanese man was admitted to the National Cancer Center, Tokyo, Japan, in December 2000, with a 2-month history of pain around the left thigh. Radiographs showed a poorly demarcated osteolytic lesion with focal mineralisation and endosteal scalloping in the left proximal femur. Biopsy showed a proliferation of highly anaplastic cells without any cartilaginous component. A wide excision of the left proximal femur with a replacement by endoprosthesis was carried out in February 2001 after treatment with methotrexate and 20 Gy radiation therapy. Pathological examination of the surgical specimen showed a focus of low-grade chondrosarcoma and the coexistence of telangiectatic osteosarcoma-like features. The patient was diagnosed with dedifferentiated chondrosarcoma with telangiectatic osteosarcoma-like features. Lung metastasis appeared in July 2001 despite an adjuvant chemotherapy including methotrexate, cis-platinum and doxorubicin. The latest follow-up study in June 2004 showed multiple lung metastases. Establishing a definitive diagnosis of dedifferentiated chondrosarcoma may be difficult with limited small biopsy specimens. Dedifferentiated chondrosarcoma should be included in the differential diagnosis of osteolytic tumours with focal calcification and endosteal scalloping even if an extraosseous tumour component is not identified.

Adult↗
PubMed2004

Effects of h-PTH on cancellous bone mass, connectivity, and bone strength in ovariectomized rats with and without sciatic-neurectomy.

The purpose of this study was to determine whether h-PTH (1-34) treatment would recover cancellous bone connectivity and bone strength in ovariectomized (OVX) or ovariectomized and sciatic-neurectomized (OVX+NX) rats. Seven-month-old female Wistar rats were treated with h-PTH or vehicle (6.0 microg/kg, six times a week, subcutaneously) for four weeks beginning 4, 8, or 12 weeks after OVX or OVX+NX. These were compared to age-matched baseline and sham-operated groups. Right tibiae were used for bone histomorphometry and node-strut analysis, and left tibiae were used for mechanical testing. The bone formation rates in the OVX and OVX+NX rats treated with h-PTH were significantly higher than those in their baseline controls. h-PTH treatment increased the node numbers and failure energies in the OVX rats, compared to their baseline controls, at all time points. However, in the OVX+NX rats, the effects of h-PTH treatment on the node number and failure energy were observed only at four weeks after surgery, but not at eight weeks or 12 weeks after surgery. These results suggest that the lowest limit, at which trabecular connectivity and bone strength are able to be restored by h-PTH, occurred between four and eight weeks in OVX+NX rats, but not in OVX rats. h-PTH cannot recover trabecular connectivity and bone strength in advanced osteopenia.

Animals↗
PubMed2004

The early snail acquires the learning. Comparison of scores for conditioned taste aversion between morning and afternoon.

The pond snail Lymnaea stagnalis acquires conditioned taste aversion (CTA) and maintains its memory for more than a month. Snails in our laboratory were cultured at 20 degrees C on a 12:12 light-dark cycle (light from 7 am to 7 pm). To examine the hours during which snails acquire CTA effectively, we trained some snails in the morning and others in the afternoon, and then compared their scores. CTA developed in both cases, but scores were significantly better in the morning than in the afternoon. To elucidate the cause of this difference in scores, we observed the voluntary activity of snails and found the circadian rhythm reflected in the snails' free-movement distances; distances at the circadian time 0-12 (daytime) were significantly longer than those at the circadian time 12-24 (nighttime). This rhythm was kept up for at least 3 days, even in constant darkness. In conclusion, L. stagnalis should be trained in the morning to acquire associative learning, possibly because of its greater propensity to roam about at that time as opposed to the afternoon.

Afferent Pathways↗
PubMed2003

Impact of postural deformities and spinal mobility on quality of life in postmenopausal osteoporosis.

The objective of the study was to evaluate the impact of postural deformities and spinal mobility on quality of life (QOL) in patients with spinal osteoporosis. A total of 157 postmenopausal women aged over 60 years with osteoporosis were divided into five groups according to their postural deformities: round back (RB, n=41), hollow round back (HRB, n=33), whole kyphosis (WK, n=40), lower acute kyphosis (LAK, n=18), and normal posture (NP, n=25). QOL was evaluated using the Japanese Osteoporosis QOL Questionnaire (JOQOL) proposed by the Japanese Society for Bone and Mineral Research. This questionnaire contains six domains, with higher scores indicating higher levels of QOL. The number of vertebral fractures, thoracic kyphosis and lumbar lordosis angles, and spinal range of motion (ROM) during maximum flexion and extension were also measured with radiographs. Total QOL scores in RB, HRB, WK, and LAK groups were significantly lower than those in the NP group, and those in WK group were even lower compared with the other groups ( P<0.05). All the groups with postural deformities, but not the NP group, showed significant positive correlations between total QOL score and spinal ROM (0.521</= r</=0.747, P<0.05). Total QOL score showed a significant correlation with age, number of vertebral fractures, lumbar lordosis angle, and spinal ROM in a total of 157 patients. However, multiple regression analysis revealed that spinal ROM best correlated with total QOL score. We concluded that QOL in patients with osteoporosis was impaired by postural deformities, especially by whole kyphosis, and that spinal mobility has a strong effect on QOL in these patients.

Activities of Daily Living↗
PubMed2003

Effects of combined treatment of insulin and human parathyroid hormone(1-34) on cancellous bone mass and structure in streptozotocin-induced diabetic rats.

The purpose of this study was to test the hypothesis that combined treatment with insulin and human parathyroid hormone (hPTH) is more effective than treatment with insulin or hPTH alone in improving cancellous bone mass, connectivity, and strength in insulin-dependent diabetic rats. Diabetes was induced by intraperitoneal injection of streptozotocin (STZ) in 7-month-old female Wistar rats. The diabetic rats received insulin, hPTH, insulin and hPTH, or hPTH vehicle for 4 weeks, starting 8 weeks after STZ injection. They were compared with baseline controls and normal controls that received STZ alone and STZ vehicle alone, respectively. The rats' proximal right tibias were processed to serve as undecalcified Villanueva-stained bone sections for histomorphometry. Changes in trabecular connectivity were determined through node-strut analysis. The decreased cancellous bone volume (BV/TV) and bone formation in diabetic rats improved in all the drug-treated groups compared with baseline controls. Furthermore, recovery of BV/TV was greater in rats that received the combination of insulin and hPTH than in those that received insulin or hPTH alone. In node-strut analysis, the node-related parameter (N.Nd/TV) significantly increased in rats that received the combination of insulin and hPTH, but did not increase in those that received insulin or hPTH alone. In addition to these results, the combination treatment significantly increased bone mineral density of the femur and bone strength in the femoral metaphysis compared with treatment with insulin or hPTH alone. These results indicate that the doses of insulin and hPTH employed in the combination treatment were more effective in improving not only bone mass but also trabecular connectivity and bone strength than treatment with insulin or hPTH alone in insulin-dependent diabetic rats.

Animals↗
PubMed2003

Osteosarcoma with cytokeratin expression: a clinicopathological study of six cases with an emphasis on differential diagnosis from metastatic cancer.

AIMS: To clarify the clinicopathological profile of osteosarcomas showing an intensely positive immunoreaction for cytokeratin. METHODS: Clinicopathological and immunohistochemical features were analysed in 131 patients with non-metastatic, conventional osteosarcoma, treated in Akita University and National Cancer Centre in Tokyo between 1972 and 1999. RESULTS: Six patients (4.5%; mean age, 32 years; four men, two women) had osteosarcomas showing intense cytokeratin expression. Tumours were located on the long bones of the extremities in five patients and the ilium in one. Osteoid formations were found in biopsied specimens in all cases. Three tumours were classified as osteoblastic osteosarcoma, two as fibroblastic, and one as chondroblastic. In three tumours classified as the osteoblastic subtype, epithelioid features were prominent, and four tumours showed pronounced cellular pleomorphism. In contrast to the expression of cytokeratin, epithelial membrane antigen was negative in all cases. Surgery with a wide excisional margin was performed in six patients. Preoperative and postoperative chemotherapy was given to five of the six patients, but the effects of these agents were negligible. Three of the six patients developed lung metastases, whereas the other three patients have remained well with no evidence of local recurrence or distant metastasis. CONCLUSIONS: Osteosarcoma with intense immunoreaction for cytokeratin was rare. The clinicopathological features were similar to those of patients with conventional osteosarcoma, except for a higher age, chemotherapy resistance, histological epithelioid features, and pleomorphism. This study indicates that osteoid formation and negative expression of epithelial membrane antigen are key features in the differentiation from metastatic carcinoma.

Adolescent↗
PubMed2003

Prognostic relevance of rosette-like features in osteosarcoma.

AIMS: To clarify the prognostic relevance of rosette-like features and other clinicopathological and immunohistochemical variables in patients with osteosarcoma. METHODS: Clinicopathological and immunohistochemical variables were analysed in 131 patients with non-metastatic high grade conventional osteosarcoma, with particular attention to the prognostic impact of rosette-like features. RESULTS: Rosette-like features were present in 18 (14%) cases. Rosette-like features were significantly associated with the osteoblastic subtype, numerous osteoclast-like giant cells, moderate pleomorphism, frequent haemangiopericytoma-like vascular patterns, epithelioid cytological features, positive immunoreactivity for epithelial membrane antigen and CD56, and negative staining for cytokeratin. In a multivariate analysis, rosette-like features (relative risk (RR), 3.8), a poor chemotherapy effect (RR, 2.9), and a tumour size of 10 cm or more (RR, 2.8) were identified as unfavourable prognostic factors. CONCLUSIONS: Rosette-like features can easily be identified from routine histological slides and the relative risk in patients with non-metastatic, conventional osteosarcoma is as high as other well known prognostic factors, including large size and poor chemotherapy effect.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2002

Stronger back muscles reduce the incidence of vertebral fractures: a prospective 10 year follow-up of postmenopausal women.

The long-term protective effect of stronger back muscles on the spine was determined in 50 healthy white postmenopausal women, aged 58-75 years, 8 years after they had completed a 2 year randomized, controlled trial. Twenty-seven subjects had performed progressive, resistive back-strengthening exercises for 2 years and 23 had served as controls. Bone mineral density, spine radiographs, back extensor strength, biochemical marker values, and level of physical activity were obtained for all subjects at baseline, 2 years, and 10 years. Mean back extensor strength (BES) in the back-exercise (BE) group was 39.4 kg at baseline, 66.8 kg at 2 years (after 2 years of prescribed exercises), and 32.9 kg at 10 years (8 years after cessation of the prescribed exercises). Mean BES in the control (C) group was 36.9 kg at baseline, 49.0 kg at 2 years, and 26.9 kg at 10 years. The difference between the two groups was still statistically significant at 10 year follow-up (p = 0.001). The difference in bone mineral density, which was not significant between the two groups at baseline and 2 year follow-up, was significant at 10 year follow-up (p = 0.0004). The incidence of vertebral compression fracture was 14 fractures in 322 vertebral bodies examined (4.3%) in the C group and 6 fractures in 378 vertebral bodies examined (1.6%) in the BE group (chi-square test, p = 0.0290). The relative risk for compression fracture was 2.7 times greater in the C group than in the BE group. To our knowledge, this is the first study reported in the literature demonstrating the long-term effect of strong back muscles on the reduction of vertebral fractures in estrogen-deficient women.

Aged↗
PubMed2001

Autologous bone grafting without screw fixation for tibial defects in total knee arthroplasty.

We evaluated 30 knees with autologous bone grafts, performed without screw fixation, for tibial defects in total knee arthroplasty (TKA). The tibial defects were classified into three types: contained, flat peripheral, and slant peripheral. The resected femoral condyle was fixed with a combination of bone cement and the tibial component, without using screws. The patients were followed for an average of 6 years and 10 months. In all knees except 1, the grafted bone united and formed good continuity with the tibial floor. Autologous bone grafting without screw fixation is a simple and effective method to deal with the tibial defects in primary TKA, especially for contained and flat peripheral defects.

Aged↗
PubMed2001

A rare anatomic variant of the superior glenohumeral ligament.

The attachment of the superior glenohumeral ligament (SGHL) to the upper pole of the glenoid is variable and 3 types have been described. We report an anatomic variant of SGHL attachment to the upper pole of the glenoid that has not heretofore been reported in the literature. In this case, the SGHL overrode the biceps origin, continued to the superior labrum posteriorly, and had no attachment to the middle glenohumeral ligament or the anterior labrum. This variant was detected during routine arthroscopic examination undertaken before surgery on a rotator cuff tear.

Adult↗
PubMed2001

Contact geometry at the undersurface of the acromion with and without a rotator cuff tear.

PURPOSE: The purpose of this study was to investigate the difference in contact geometry at the undersurface of acromion in shoulders with and without a rotator cuff (RC) tear. TYPE OF STUDY: Case-control study. METHODS: Forty fresh cadaveric shoulders (average age at death, 61 years) without gross osteoarthritic changes were divided into the intact RC group (n = 20) and the RC tear group (n = 20). Clinical impingement was simulated by compressing the humeral head and the intact portion of the RC against the coracoacromial arch with an axial compressive force of 25 kg while the humerus was held abducted 20 degrees in the scapular plane. The contact pattern between the acromion and the RC was measured with Fuji Prescale super low-pressure-sensitive film (Fuji Photo Film Co, Ltd, Tokyo, Japan). The imprint image was analyzed using Global Lab image software (Automatix, Marlboro, MA). RESULTS: The percentage of the maximum anteroposterior dimension of the imprint on Fuji film to the anteroposterior diameter of the acromial undersurface was 29% +/- 9% in intact RC shoulders, and 39% +/- 13% in shoulders with an RC tear (P >.05). The percentage of the maximum mediolateral dimension of the imprint to the mediolateral diameter of the corresponding part of the acromial undersurface was 27% +/- 12% in intact RC shoulders, and 48% +/- 11% in shoulders with an RC tear. This difference was statistically significant (P <.005). CONCLUSIONS: The contact geometry of the acromial undersurface with the underlying RC in the anteroposterior dimension, which might be related to the appearance in supraspinatus outlet view, was not significantly different between shoulders with and without an RC tear. These findings suggest that factors other than acromial shape play a significant role in the pathogenesis of RC tears. The implication regarding the role of acromioplasty remains to be clarified.

Acromion↗
PubMed2001

Long-term effects of withdrawal of bisphosphonate incadronate disodium (YM175) on bone mineral density, mass, structure, and turnover in the lumbar vertebrae of ovariectomized rats.

This study was designed to evaluate the long-term effects of incadronate disodium (YM175) after its withdrawal on cancellous bone mass in ovariectomized (OVX) rats. Thirteen-week-old female SD rats were randomized into four groups: sham-operated, OVX, low-YM, and high-YM (0.01 mg/kg or 0.1 mg/kg subcutaneously [sc], three times a week after OVX) groups. After 4 weeks of treatment with vehicle or YM175, rats from each group were killed at time points of 0 (baseline), 3, 6, 9, and 12 months after withdrawal of the agent. Bone mineral density (BMD) of the lumbar vertebrae was measured by dual-energy X-ray absorptiometry (DXA). Bone volume (BV/TV), trabecular number and trabecular separation (Tb.N and Tb.Sp), eroded surface (ES/BS), osteoclast number and osteoclast surface (N.Oc/BS and Oc.S/BS), osteoid surface (OS/BS), and bone formation rate (BFR/BS) were measured as histomorphometric parameters of the fifth lumbar vertebra. BMD, BV/TV, Tb.N, and Tb.Sp in YM175-treated groups were maintained at the same level as in the sham group until 12 months after withdrawal in the high-YM group and until 3 months after withdrawal in the low-YM group. YM175 decreased both bone formative and resorptive parameters in histomorphometry. Serum bone-specific alkaline phosphatase (ALP) and urinary deoxypyridinoline at both doses of YM175 also showed a suppressive effect of this agent on bone turnover. These results indicate that YM175, after withdrawal, still maintains bone volume dose dependently by depressing bone resorption and formation in OVX rats. Intermittent YM175 treatment with a long interval may be sufficient to maintain the bone volume and structure in OVX rats.

Aging↗
PubMed2001

Position of immobilization after dislocation of the glenohumeral joint. A study with use of magnetic resonance imaging.

BACKGROUND: Glenohumeral dislocations often recur, probably because a Bankart lesion does not heal sufficiently during the period of immobilization. Using magnetic resonance imaging, we assessed the position of the Bankart lesion, with the arm in internal and external rotation, in shoulders that had had a dislocation. METHODS: Coaptation of a Bankart lesion was examined with use of magnetic resonance imaging, with the arm held at the side of the trunk and positioned first in internal rotation (mean, 29 degrees) and then in external rotation (mean, 35 degrees), in nineteen shoulders. Six shoulders (six patients) had had an initial anterior dislocation, and thirteen shoulders (twelve patients) had had recurrent anterior dislocation. Fast-spin-echo T2-weighted axial images were made when the dislocation had occurred less than two weeks earlier, and spin-echo T1-weighted axial images after intra-articular injection of gadolinium-diethylenetriamine pentaacetic acid were made when the dislocation had occurred more than two weeks earlier. Separation and displacement of the anteroinferior portion of the labrum from the glenoid rim were measured on the axial images, and coaptation of the anterior part of the capsule to the glenoid neck was assessed by measurement of the detached area, opening angle, and detached length. RESULTS: Separation and displacement of the labrum were both significantly less (p = 0.0047 and p = 0.0017, respectively) when the arm was in external rotation than when it was in internal rotation. The detached area and the opening angle of the anteroinferior portion of the capsule were both significantly smaller (p = 0.0003 and p < 0.0001, respectively), and the detached length was significantly shorter (p < 0.0001) with the arm in external rotation. CONCLUSION: Immobilization of the arm in external rotation better approximates the Bankart lesion to the glenoid neck than does the conventional position of internal rotation.

Adolescent↗
PubMed2000

Intra-articular membranous interposition detected by MRI in developmental dysplasia of the hip.

Intra-articular membranous interposition was detected by MRI in the hip joint with residual subluxation of a girl aged 5 years 10 months. This structure, which had low signal intensity on both T1- and T2-weighted images, separated the femoral head from the acetabulum. Histological examination revealed chondrometaplasia, which suggested that this interposition might be transformed to a surface cartilaginous tissue of the secondary acetabulum often observed in residual subluxation of the hip.

Acetabulum↗
PubMed2000

Anatomy and biomechanics of the shoulder.

The anatomies and biomechanics of the glenohumeral joint and the scapulothoracic articulation are the subjects of this article. The anatomies of bones, joints, ligaments, and muscles are described in detail, and current biomechanical concepts concerning motion, stability, and force are presented. Morphologic and biomechanical changes in pathologic conditions briefly are described.

Biomechanical Phenomena↗
PubMed2000

The relevance of the moment arm of shoulder muscles with respect to axial rotation of the glenohumeral joint in four positions.

OBJECTIVE: This study was undertaken to determine the efficiency of the shoulder girdle muscles during axial humeral rotation based on measurements of the moment arms. DESIGN: The instantaneous muscle moment arms of 10 shoulder muscles, including the three portions of the deltoid, the rotator cuff muscles, teres major, and the thoracohumeral muscle group, were measured during four specified glenohumeral rotations. BACKGROUND: Axial humeral rotation is a commonly performed movement during activities of daily living and is a targeted motion of shoulder rehabilitation, particularly in those protocols emphasizing rotator cuff strengthening. An understanding of the function of the movers and stabilizers of the shoulder requires such basic information of muscle moment arms. METHODS: The instantaneous moment arm values of the muscles were derived from the slope of the plot of tendon excursion versus glenohumeral joint rotation angle. Motion studied included axial rotation with the humerus elevated 90 degrees in the coronal, scapular, and sagittal planes, as well as in the neutral position with the arm at the side. RESULTS: Based on the findings, with the humerus in both neutral and elevated positions, the infraspinatus is potentially the most powerful external rotator, followed by teres minor and posterior deltoid. Subscapularis and possibly pectoralis major are the most effective internal rotators in this position. CONCLUSIONS: The moment arm in providing axial humeral rotation of 10 shoulder muscles in four planes were obtained. In general, the teres minor and infraspinatus had the largest moment arms in external rotation, and the subscapularis had the largest moment arm in internal rotation. The muscle function for axial humeral rotation was found to be modified by the plane of arm elevation. RELEVANCE: The data could be used for developing exercise programs in physical therapy.

Adult↗