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Biomedical subjects

Shinjiro Takata

Publications and source records attributed to Shinjiro Takata.

15 recordsLinked to original sources
PubMed2006

Metaphyseal dysplasia of Braun-Tinschert type: report of a Japanese girl.

We report on a 7-year-old Japanese girl with metaphyseal dysplasia (MD) of Braun-Tinschert type, a recently recognized, autosomal dominant sclerosing bone dysplasia. All individuals with the disorder from four families in the literature originated from a small town in Bohemia or its vicinity. The occurrence of the disorder in a Japanese girl indicates that it is not restricted to Germans. The radiographic hallmarks of the disorder include metaphyseal undermodeling (Erlenmeyer-flask deformity); osteosclerosis of the chondroosseous junctions, metaphyseal cortices, and epiphyseal margins; and exostosis-like bone excrescences at the metaphyseal-diaphyseal junctions. In the girl we described, the latter two findings were conspicuous at age 4 years, but became less prominent with increasing age. The metaphyseal trabeculae were somewhat coarse. The humeri exhibited varus deformity, and the ulnae and fibulae mild bowing. The mean bone mineral density of the lumbar spine was lower than that of age-matched controls. The patient exhibited premature loss of primary teeth, likely to be a sign of increased periodontal bone resorption. Markers of bone formation and resorption were both increased, an indication of a high rate of bone turnover.

Abnormalities, Multiple↗
PubMed2006

Bisphosphonate modulates morphological and mechanical properties in distraction osteogenesis through inhibition of bone resorption.

Despite the general clinical acceptance of distraction osteogenesis and much attention to bone formation in this method, little is recognized about activated bone resorption in the regenerated bone. The purpose of this study was to demonstrate the simultaneously activated bone resorption with activated bone formation and to investigate the role and efficacy of bisphosphonate in distraction osteogenesis. Left tibiae of 54 immature rabbits were lengthened for 3 weeks at a rate of 0.7 mm/day after a 1-week lag. Regenerated bone was quantitatively investigated by radiographic bone density, bone histomorphometry, and three-point bending testing. Animals received either vehicle or nitrogen-containing bisphosphonate (N-BP), YM529/ONO5920 at doses of 0.4 mg/kg/w or 0.004 mg/kg/w for 6 weeks. Regenerated bone of the vehicle group showed a radiologically characteristic zone structure containing the osteopenic zones adjacent to the sclerotic zones. The regenerated bone of the 0.4-mg/kg/w group showed no osteopenic zones during the course and eventually became homogeneously radiodense. The bone volume corresponding to the osteopenic zone of this group was 5.6-fold greater compared with that of the vehicle group. The lengthened bone strength of this group was 3.3-fold greater in ultimate force than that of the vehicle group and equivalent to the contralateral tibia. The 0.004-mg/kg/w group had no substantial differences compared with the vehicle group, despite radiological enhancement of the mineralized front as well as somewhat delayed bone resorption. These results demonstrate that not only bone formation but also bone resorption is highly activated in the regenerated bone, implying high bone turnover. Sufficient N-BP caused a notable modulation in morphological properties of the regenerated bone through inhibition of highly activated bone resorption and eventually increased mechanical properties.

Absorptiometry, Photon↗
PubMed2006

Prevalence and clinical features of Paget's disease of bone in Japan.

The present study aimed to evaluate the prevalence and clinical presentation of Paget's disease of bone (PDB) in Japan. As PDB is a very rare disease in Japan, a nationwide mail survey was conducted targeting doctors in the specialty most frequently diagnosing and treating PDB patients in Japan. First, the literature for all case reports in Japan published between January 1990 and December 2002 was reviewed to determine who was diagnosing and treating PDB in Japan. This literature review for all case reports in Japan revealed that 72.1% of cases in Japan were reported from departments of orthopedic surgery. A nationwide two-phase mail survey was conducted for the departments of orthopedic surgery of 2,320 general hospitals accredited by the Japanese Orthopaedic Association. Phase 1 involved determining how many patients with PDB were followed at each hospital. If the answer was one or more, phase 2 of the survey gathered information on the clinical presentation of current patients. The mail survey yielded a final response rate of 75.4% for phase 1 and 87.6% for phase 2. Phase 1 indicated that the prevalence of PDB in Japan is about 2.8 cases per million capita. Phase 2 revealed a slight female predominance, lower frequency of familial clustering, higher frequency of femoral fracture in the affected femur, and a higher ratio of symptomatic PDB in Japan compared with findings in countries displaying a higher prevalence of PDB. The present epidemiological study revealed that the disorder is extremely rare in Japanese individuals, and that some differences exist with regard to the clinical features of PDB between Japanese patients and patients from high-prevalence countries.

Adult↗
PubMed2006

Guidelines for diagnosis and management of Paget's disease of bone in Japan.

We here propose guidelines for the diagnosis and management of Paget's disease of bone (PDB) in Japan. These guidelines provide basic information on the epidemiology, pathophysiology, clinical signs and symptoms, diagnosis, indications for treatment, and available therapy, including orthopedic surgery. PDB is a chronic disorder characterized by focal abnormalities of bone turnover. The characteristic feature of PDB is excessive osteoclastic bone resorption coupled to increased and disorganized bone formation. The most common symptom of PDB is pain in involved bones. The most serious complication of PDB is malignant bone or soft-tissue tumor. PDB is uncommon in Japan; our survey in 2003 found 169 patients with PDB. The prevalence of PDB in Japan is 0.15/100 000; in patients aged 55 years or more, the proportion reaches 0.41/100 000. A careful medical history and physical examination are essential for the diagnosis. The diagnosis of PDB is based on finding the typical features on radiographs. Bone scintigraphy and measurement of serum alkaline phosphatase are sensitive means of screening for PDB. Since PDB is a rare disease in Japan, bone biopsy is quite often used to exclude bone metastases. The only evidence-based indication for treatment of PDB is pain in involved bones. In Japan, etidronate and calcitonin are approved by the Ministry of Health, Labour and Welfare for treating PDB, but currently risedronate is also under development for treating PDB in Japan. Indications for surgical intervention in PDB include unstable fractures, osteoarthritis, malignant soft-tissue tumor, osteosarcoma, and bone deformity.

Humans↗
PubMed2006

[Therapeutic effects of risedronate on Paget's disease of bone].

Paget's disease of bone (PDB) is a chronic disorder characterized by focal abnormalities of bone turnover. The characteristic feature of PDB is excessive osteoclastic bone resorption coupled to increased and disorganized bone formation. Although PDB is rare in Japan, it is quite common in most European countries, except for Scandinavia. The recommended regimens for bisphosphonates use in various parts of the world. Calcitonin and etidronate are approved by the Ministry of Health, Labour and Welfare in Japan to treat PDB. Risedronate is currently under development for use in the treatment of PDB in Japan.

Aged↗
PubMed2006

[Paget's disease of bone].

Paget's disease of bone (PDB) is a chronic disorder characterized by focal abnormalities of bone turnover. The symptoms of PDB include bone pain, bone deformity, osteoarthritis, and an increase in risk of pathological fracture and neurological problems. PDB is the second most common metabolic bone disease in European countries, although PDB is uncommon in Japan. PDB shows geographical and ethnic clustering. Based on this, two hypotheses of etiology of PDB have been proposed. One hypothesis is that PDB results from a slow virus infection of osteoclasts with paramyxovirus. The other is that PDB is a genetic disease. The development of bisphosphonate has brought major changes to the treatment of PDB. In Japan, etidronate and calcitonin are approved by the Ministry of Health, Labour and Welfare for treating PDB. Risedronate is under development for treating PDB in Japan.

Humans↗
PubMed2004

Biophysic evaluation of bone quality-application of Fourier transform infrared spectroscopy and phosphorus-31 solid-state nuclear magnetic resonance spectroscopy.

In this review, we focus on findings obtained with biophysic techniques, Fourier transformed infrared (FTIR) spectroscopy and phosphorus-31 solid-state nuclear magnetic resonance (31P solid-state NMR) spectroscopy, which may allow us to evaluate bone quality and to predict bone strength. FTIR measures the absorption energy that produces an increase in the vibrational or rotational energy of atoms or groups of atoms within the molecule. FTIR spectroscopy allows us to examine the relative amount of minerals and matrix content and the arrangement of apatite and organic matrix. FTIR spectroscopy should become an important tool, because the relative amount of minerals and the arrangement of apatite and organic matrix could be a measure for evaluating bone quality. 31P solid-state NMR spectroscopy is useful for evaluating the quality of bone and predicting bone strength by calculating the spine-lattice relaxation time (T1) of bone. 31P solid-state NMR imaging can be used to measure quantitatively the mass of hydroxyapatite. The T1 relaxation time of both bone and deficient hydroxyapatite was much longer than that of pure hydroxyapatite. T1 relaxation time is one of the promising indices of bone quality.

Animals↗
PubMed2004

Effects of unilateral sciatic neurectomy on growing rat femur as assessed by peripheral quantitative computed tomography, Fourier transform infrared spectroscopy and bending test.

We studied the effects of unilateral sciatic neurectomy (USN) on the development of the femoral shaft in the 30 growing Wistar-derived rats aged 5 weeks. Rats were allocated to three groups. One of these was immediately used for measurements, and the remaining 2 groups underwent USN of internal control. Specimens obtained from each group were divided into 2 subgroups: left femurs of each group served as the control subgroup (CONT) and right femurs from each group as the USN-operated subgroup (USN-OP). The bone mineral density (BMD), bone mineral content (BMC), bone area, periosteal circumference and endosteal circumference were measured by peripheral quantitative computed tomography (pQCT) and the mineral/matrix ratio was evaluated by Fourier transform infrared spectroscopy (FTIR). A three-point bending test was performed to analyze the biomechanical effects of sciatic neurectomy. USN-OP showed a significant decrease in cortical BMC, bone area, and periosteal circumference compared with CONT. The mineral/matrix ratio of cortical bone did not differ significantly between USN-OP and CONT. Strength and stiffness were significantly decreased in USN-OP compared with CONT. The results showed that USN inhibited periosteal bone formation, but has no significant effects on the mineral/matrix ratio of cortical bone in femurs.

Animals↗
PubMed2002

Effects of constitution, atraumatic vertebral fracture and aging on bone mineral density and soft tissue composition in women.

Constitution, atraumatic vertebral fracture and aging affect bone mineral density (BMD) and soft tissue composition. The high body weight of obese women involves a high mechanical load being exerted on weight bearing bones compared with thin women, which probably contributes to their higher BMD and the lower incidence of fractures in obese women compared with thin women. Atraumatic vertebral fracture (AVF) is a typical osteoporotic fracture and its favorite site of AVF is the vertebral bodies of the thoracolumbar region. The BMD of weight bearing bones is lower in patients with AVF than in patients without AVF, whereas there is no significant difference in soft tissue composition between the two. The regional and total BMD decrease with advancing age. The magnitude of the decrease in lumbar and thoracic BMD is high compared with other regional BMD, and total fat mass and total lean mass decline with age to their respective minimal level. The high rate of decrease in lumbar and thoracic BMD appears to be due to the high content of trabecular bone compared with other regional bones.

Aging↗
PubMed2002

Intergenerational comparison of total and regional bone mineral density and soft tissue composition in Japanese women without vertebral fractures.

We measured total and regional bone mineral density (BMD) and soft tissue mass in 115 healthy Japanese women without vertebral fractures. The subjects, aged 20 to 75 years, were divided into four age groups: 20's to 40's group (n=33), 50's group (n=26), 60's group (n=26), and 70's group (n=30). BMD was measured by dual energy X-ray absorptiometry (DXA). The evaluated regions were the head, arms, legs, ribs, thoracic vertebrae, lumbar vertebrae and pelvis. The total and regional BMDs were the highest in the 20's to 40's group, and they decreased with age, and reached their respective lowest values in the 70's group. The decrease in BMDs of the spine and pelvis was the most prominent of all regional BMDs. Total and regional lean mass and fat mass were the highest in the 20's to 40's group, and they decreased to their respective lowest values in the 70's group. The results showed that the decrease in BMD of the spine and pelvis was the most prominent of all regional BMDs associated with a decrease in the total and regional lean mass and total and regional fat mass.

Absorptiometry, Photon↗