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Abstract Objectives--To investigate the effects of collagen induced arthritis (CIA) on the tensile properties of rat anterior cruciate ligament (ACL). Methods--The tensile strength, bone mineral density (BMD), and histology of [...]

The formability in friction stir and arc welded 5083 Al alloys was investigated. The elongation in friction stir welded material under uniaxial tensile test increased with the decrease in friction heat flow during friction stir welding (FSW) and the value of dome height under biaxial bulge test increased with friction heat flow. The ductility improved according to changes in FSW condition and FS-welded alloy sheet exhibited excellent formability.

Abstract: To determine the bone mineral changes after total hip arthroplasty, bone mineral densities (BMD) at the periprosthetic interface, lumbar spine, radius, and calcaneus were measured in a prospective and longitudinal observation. Twenty-four patients (24 joints) who had received a total hip arthroplasty and were followed longitudinally were enrolled in this study. The subjects comprised 2 men and 22 women with a mean age of 69.2 years at the time of surgery. Bone mineral measurements were performed at 1, 3, 6, 12, 18, 24, 30, and 36 months after surgery. The periprosthetic BMD after total hip arthroplasty continued to decrease for 6–12 months after surgery, and then recovered, except in Gruen zone 7 (the calcar region). The calcaneal BMD decreased rapidly for 3 months after surgery before increasing. The lumbar BMD showed a decreasing trend for 12 months after surgery, and then increased gradually. The radial BMD was not affected by surgery. We conclude that changes in the periprosthetic BMD after total hip arthroplasty show an apparent difference between zones, and also differ between the weight-bearing bones and the nonweight-bearing bones.

Abstract: Sensitivity and specificity were compared among the American College of Rheumatology (ACR) 1987 classification criteria, the Yamasaki diagnostic criteria, and the Japan Rheumatism Association (JRA) diagnostic criteria for early rheumatoid arthritis (RA). The study included 90 patients who consulted our department for the first time within 1 year after onset and were suspected of having RA (final diagnosis: RA 45 cases, non-RA 45 cases). We investigated whether physical and laboratory findings at the first examination met these three sets of criteria to determine the sensitivity and specificity of each set of diagnostic criteria. Moreover, the sensitivity and specificity of each item in the diagnostic criteria set were similarly determined. The sensitivity of the ACR 1987 classification criteria, the Yamasaki diagnostic criteria, and the JRA diagnostic criteria for early RA were 71.1%, 88.9%, and 95.6%, respectively, and their specificities were 100%, 93.3%, and 77.8%, respectively. In a study on each diagnostic item, observation for 1 week was considered to be sufficient for morning stiffness, swelling in three joint areas, and symmetrical swelling, while observation for a more prolonged period seemed to be necessary for swelling of the finger and hand joints. The Yamasaki diagnostic criteria are appropriate for the diagnosis of early RA, while the JRA diagnostic criteria are suitable for screening.

A survey of all fractures in patients ≥35 years of age for hip, distal radius, and proximal humerus was performed in Tottori Prefecture, Japan. Hip fracture survey was done for the years 1986–1988, and also 1992–1994. A distal radius and proximal humerus fracture survey was done for the years 1986–1988, 1992, and 1995. The age- and gender-specific incidence rates of these three types of fracture among Japanese were substantially lower than those of whites living in North America or northern Europe. The age-adjusted incidence rates of hip fracture (per 100,000 person-years) were 40.7 and 114.1 in 1986 and 57.1 and 145.2 in 1994 for men and women, respectively, showing a significant increase with time for women. Upon examination of individual fracture types, there was no significant increase in cervical fractures, whereas a significant increase was observed in trochanteric fractures for women. The age-adjusted incidence rates of distal radius fractures for women were 164.9 in 1986 and 211.4 in 1995, showing a significant increase with time; however, no increase was observed among men. Incidence of proximal humerus fractures was 10.3 and 42.0 in 1986 and 17.1 and 47.9 in 1995 for men and women, respectively, and these increases were significant for both genders.

We investigated the effect of 2-β-(3-hydroxypropoxy)-1α,25-dihydroxyvitamin D3(ED-71) on the modeling of bone in distraction osteogenesis. The tibiae of 30 rabbits were lengthened by 10 mm in 10 days. Following osteotomy, ED-71 (0.05 μg/kg) was administered subcutaneously twice a week to the ED-71 group until necropsy. The bone mineral content (BMC) of the lengthened callus was measured by dual-energy X-ray absorptiometry (DXA). Five rabbits per group were killed at 1, 3, and 8 weeks after completion of lengthening, and the lengthened callus was examined histologically and histomorphometrically. Bone volume of the lengthened callus was measured by peripheral quantitative computed tomography (pQCT) at 8 weeks after the completion of lengthening. At all timepoints the BMC in the ED-71 group was significantly higher than that in the untreated group. The mineral apposition rate and bone formation rate were higher in the ED-71 group than in the untreated group at 1 and 3 weeks after the completion of lengthening on the coronal section. In cross sections, the cortical area and width in the ED-71 group showed significantly higher values than in the untreated group at 8 weeks after the completion of lengthening. Both the endosteal osteoid surface and endosteal eroded surface showed no differences between groups. However, the endosteal mineral apposition rate and endosteal bone formation rate were significantly higher in the ED-71 group. At 8 weeks after completion of lengthening, the intracortical area and intracortical BMC were significantly greater in the ED-71 group than in the untreated group, but no significant difference was noted in intracortical BMD. These findings indicate that ED-71 increases callus volume during the early period after the completion of lengthening, resulting in thick cortical bone formation.

Distraction osteogenesis in the mandible is a promising method, not only for correction of mandibular hypoplasia such as hemifacial microsomia, but also for reconstruction of segmental bone defects in the mandible. The authors report a case in which a mandibular segmental defect, about 60 mm in length, was reconstructed by distraction osteogenesis. The patient was a 45-year-old man who had been treated for an oral floor cancer. After preoperative chemotherapy and irradiation therapy, the mandible had been resected from the second incisor on the right side to the first molar on the left side, and had been reconstructed with a titanium plate and a vascularized rectus-abdominis compound flap. However, an infection developed around the titanium plate and this plate had to be removed. Therefore, trifocal distraction using an original three-dimensional distractor was performed, at the rate of 1 mm per day (0.5 mm in the morning and 0.5 mm in the evening). During the distraction period, the skin flap was pushed out from the bone defect. Although small free bone transplants were needed for complete continuity, the segmental bone defect was almost filled by the regenerated bone with the lengthened gingiva. Radiographic observation showed successful new bone formation in the lengthened area.

AbstractKimura’s disease is a benign chronic granulomatous disease which presents as a subcutaneous swelling in the head and neck area. The histopathological feature consists of granuloma-forming lymphoid follicles with eosinophil infiltration. Kimura’s disease of the larynx is very rare, and only a few cases have been reported. We report a 14-year-old boy who presented with sleep apnea. Laryngological study revealed a submucosal swelling of the bilateral false vocal cord. Histopathological examination showed lymphoid hyperplasia with marked infiltration of eosinophils, which was diagnosed as Kimura’s disease. After laser surgery, he had recurrent swelling of the false cord. The patient was given 30 mg of prednisolone, which was gradually tapered. The laryngeal swelling resolved, and the sleep apnea immediately improved after the treatment. However, a low dose of prednisolone was necessary to maintain the remission. Oral administration of pranlukast successfully supported the tapering of prednisolone.Copyright © 2003 S. Karger AG, Basel

Abstract: Bone mineral density (BMD) of both radii and lumbar vertebrae was measured by single-photon absorptiometry and dual X-ray absorptiometry, respectively, before and 2.1–4.8 years after a unilateral wrist synovectomy in 10 patients with rheumatoid arthritis. Radial BMD on the operated side significantly increased after synovectomy, while that on the non-operated side did not change. Lumbar BMD significantly decreased after the operation. The grip strength of the operated side increased significantly after synovectomy, while there were no changes in the grip strength on the non-operated side. These findings suggest that wrist synovectomy results in pain relief and improves use, thereby increasing the BMD of the operated radius.

The incidence of fractures of the distal radius in Japanese persons under 20 years of age was determined, and the bone mineral density of the radius was measured in 236 healthy Japanese children. The peak incidence of fractures occurred at 13 years of age (807 per 100000) in boys and at 11(300 per 100000) in girls. Bone mineral density increased with age, but the rate of increase was not equal at the metaphysis and the diaphysis in the parapubertal period. The metaphyseal/diaphyseal ratio of bone mineral density was lowest at the age of 12–13 years in boys and 11 years in girls. The age at the peak incidence of fractures thus coincided with the age at which the metaphyseal/diaphyseal density ratio was lowest. Thus, it is suggested that low bone mineral density at the metaphysis may be the cause of the high incidence of these fractures in adolescence.

We report the incidence of proximal femur and distal radius fractures in Tottori prefecture, Japan. In 1986 and 1987, 573 proximal femoral fractures and 1576 distal radial fractures were registered in this district. The age- and sex-specific incidence rates of these two fractures are lower among Japanese than among European or North American whites, according to previous reports. Thus, it was concluded that the incidence rates of these two fractures are lower in Japanese than in Caucasians.

The in-plane effective thermal conductivity of free-standing Si thin films with periodic micropores was measured at -100 to 0 degC. The Si thin films with micropores were prepared from silicon-on-insulator (SOI) wafers by standard microfabrication processes. The dimensions of the free-standing Si thin films were 200umx150umx2 um, with staggered 4 um pores having an average pitch of 4 mm. The Si thin film serves both as a heater and thermometer. The average temperature rise of the thin film is a function of its in-plane thermal conductivity. The effective thermal conductivity was calculated using a simple one-dimensional heat conduction model. The measured thermal conductivity was much lower than that expected based on classical model evaluations. A significant phonon size effect was observed even in the microsized structures, and the mean free path for phonons is very long even at the room temperature.