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Biomedical subjects

Jun Iwamoto

Publications and source records attributed to Jun Iwamoto.

82 records · Page 5Linked to original sources
PubMed2002

Forearm bone mineral density in postmenopausal women with osteoarthritis of the knee.

The aims of the present study were to clarify whether postmenopausal women with osteoarthritis (OA) of the knee show higher bone mineral density (BMD) than healthy controls, and to investigate the relationship between BMD and the Kellgren and Lawrence radiological grade in postmenopausal women with OA of the knee. A total of 674 postmenopausal women, 46-90 years of age, were enrolled in the study: 305 patients with OA of the knee and 369 healthy controls. Forearm (distal radius) BMD, measured by dual-energy X-ray absorptionetry (DXA), using a DTX-200 (Osteometer), was significantly higher in the OA group than in the control group (P < 0.001), even when adjusted for age, height, body weight, body mass index, years since menopause, and grip strength (P < 0.01). Analysis of variance (ANOVA) with Fisher's protected least significant difference (PLSD) test showed that BMD in radiological grades 2, 3, and 4 was significantly higher than that in grade 1 (P < 0.05, P < 0.001, and P < 0.05, respectively), and BMD in grade 3 was significantly higher than that in grade 2 (P < 0.01), but BMD in grade 4 was significantly lower than that in grade 3 (P < 0.05). These findings suggest that forearm BMD appears to be significantly higher in postmenopausal women with OA of the knee than in healthy controls. Although BMD may be increased in low to moderate radiological grades of OA, severe grade OA may not always develop from moderate grade OA. Some cases of severe grade OA may be associated with low BMD.

Aged↗
PubMed2002

Effect of surgical treatment on physical activity and bone resorption in patients with neurogenic intermittent claudication.

The effect of surgical treatment on physical activity and bone resorption was examined in patients with neurogenic intermittent claudication. Nineteen patients, 50-77 years of age, with neurogenic intermittent claudication (mean, 162 m; range, 20-400 m) caused by degenerative lumbar disease were included in the study. Decompressive laminectomy alone was performed for 7 patients with lumbar spinal stenosis (LSS) and 5 patients with degenerative lumbar spondylolisthesis (DLSL), and decompressive laminectomy, with a Graf stabilization system, was performed for 7 patients with DLSL associated with flexion instability. Clinical symptoms and levels of urinary cross-linked N-telopeptides of type I collagen (NTx) were assessed before and 12 months after surgery. Subjective symptoms, including low back pain, leg pain and/or tingling, and gait disturbance, as well as restriction of activities of daily living were significantly alleviated by the surgical treatment, resulting in an increase in physical activity. Urinary NTx levels were significantly decreased by the surgical treatment, from 63.1 +/- 16.9 (mean +/- SD) nmol BCE/mmol Cr to 52.1 +/-11.2 nmol BCE/mmol Cr (P < 0.05). These findings suggest that surgical treatment appears to alleviate the clinical symptoms and increase physical activity in patients with LSS or DLSL, potentially resulting in the suppression of bone resorption. Surgical treatment may contribute to the prevention of physical inactivity-induced osteoporosis in elderly patients with neurogenic intermittent claudication caused by degenerative lumbar disease.

Aged↗
PubMed2002

Functional roles of nasal nitric oxide in nasal patency and mucociliary function.

The purpose of this study was twofold: (i) to clarify whether it is possible to change the amount of nasal nitric oxide (NO) artificially; and (ii) to confirm that the artificially altered nasal NO has biological properties such as vasodilatation and mucociliary function. We measured nasal NO and nasal airway resistance (NAR) in healthy subjects before and after topical administration of sodium nitroprusside (SNP), an NO donor. We also measured nasal NO and saccharin transport time after administration of SNP or L-N(G)-nitroarginine methylester (L-NAME), a NO synthase inhibitor. In addition, we examined the effect of SNP and L-NAME on nasal NO and saccharin transport time after pretreatment with flutropium bromide (FB), an anticholinergic agent. Administration of SNP elicited increases in nasal NO and NAR in a dose-dependent manner. Nasal NO decreased significantly after topical administration of L-NAME. Saccharin transport time, an indicator of mucociliary function, was shortened after topical administration of SNP and prolonged after administration of L-NAME. Moreover, these phenomena were observed even after pretreatment with FB. These results suggest that artificially altered nasal NO may affect NAR and mucociliary function.

Administration, Topical↗
PubMed2002

Beneficial effect of etidronate on bone loss after cessation of exercise in postmenopausal osteoporotic women.

OBJECTIVES: To determine whether etidronate could prevent or restore bone loss after cessation of exercise in postmenopausal osteoporotic women. DESIGN: Thirty-five postmenopausal osteoporotic women were studied. Exercise consisted of daily brisk walking and gymnastic training. The changes in the lumbar bone mineral density measured by dual energy x-ray absorptiometry were assessed. RESULTS: One or two years of exercise increased the bone mineral density from the baseline. One year of cessation of exercise after 1 yr of exercise resulted in the loss of the bone mineral density gained through exercise. Two years of cyclical etidronate treatment from year 2 sustained the bone mineral density during 2 yr of cessation of exercise in the preventative etidronate treatment group and completely restored the loss of bone mineral density after 1 yr of cessation of exercise in the therapeutic etidronate treatment group. CONCLUSIONS: Cyclical etidronate treatment, when exercise is discontinued, seems to be beneficial for the prevention or restoration of bone loss after cessation of exercise in postmenopausal osteoporotic women. Although the present study has a small sample size, the results may be interesting, especially because they raise additional questions that could stimulate further research.

Absorptiometry, Photon↗
PubMed2002

Ambient oxygen regulates epithelial metabolism and nitric oxide production in the human nose.

The effects of ambient O(2) tension on epithelial metabolism and nitric oxide (NO) production (VNO) in the nasal airway were examined in nine healthy volunteers. Nasal VNO, O(2) consumption (VO(2)), and CO(2) production (VCO(2)) were measured during normoxia followed by gradual hypoxia from 21 to 0% O(2) concentration. Nasal VO(2), VCO(2), and respiratory quotient during normoxia were determined to be 1.19 +/- 0.04 ml/min, 1.60 +/- 0.04 ml/min, and 1.35 +/- 0.04, respectively. Hypoxia exposure to the nasal cavity significantly decreased both VCO(2) and VNO [VCO(2): 1.60 +/- 0.04 to 0.96 +/- 0.03 ml/min (P < 0.01), VNO: 530 +/- 15 to 336 +/- 9 nl/min (P < 0.01)]. VNO was reduced commensurately with gradual decline in O(2) tension, and the apparent K(m) value for O(2) was determined to be 23.0 microM. These results indicate that the nasal epithelial cells exchange O(2) and CO(2) with ambient air in the course of their metabolism and that nasal epithelial cells can synthesize NO by using ambient O(2) as a substrate. We conclude that air-borne O(2) diffuses into the epithelium where it may be utilized for either cell metabolism or NO synthesis.

Adult↗
PubMed2002

[Efficacy of combined administration of vitamin D3 and vitamin K2 for primary osteoporosis].

The literatures that reported the efficacy of combined administration of vitamin D(3) and vitamin K(2) for primary osteoporosis are reviewed. Combined administration of vitamin D(3) and vitamin K(2) potentially stimulates bone formation (mineralization) in patients with primary osteoporosis, resulting in an increase in lumbar bone mineral density. Combined administration of vitamin D(3) and vitamin K(2) seems to have the greatest effect on lumbar bone mineral density in the studies in which the mean age and years since menopause of the subjects were low, in contrast to administration of antiresorptive agents, bisphosphonates that has the greatest effects on bone mineral density and incidence of vertebral fractures in the studies in which the mean age and years since menopause are high, and the subjects have marked clinical evidence of osteoporosis. Further prospective, randomized, well-controlled study with long duration of observation is needed to confirm the efficacy of combined administration of vitamin D(3) and vitamin K(2) for primary osteoporosis.

English Abstract↗
PubMedDate not supplied

The prevention of hip fracture with risedronate and ergocalciferol plus calcium supplementation in elderly women with Alzheimer disease: a randomized controlled trial.

BACKGROUND: A high incidence of fractures, particularly of the hip, represents an important problem in patients with Alzheimer disease (AD), who are prone to falls and have osteoporosis. We previously found that deficiency of 25-hydroxyvitamin D and compensatory hyperparathyroidism cause reduced bone mineral density in female patients with AD. We address the possibility that treatment with risedronate sodium and ergocalciferol plus calcium supplementation may reduce the incidence of nonvertebral fractures in elderly women with AD. METHODS: A total of 500 elderly women with AD were randomly assigned to daily treatment with 2.5 mg of risedronate sodium or a placebo, combined with 1000 IU of ergocalciferol and 1200 mg of elementary calcium, and followed up for 18 months. RESULTS: At baseline, patients of both groups showed 25-hydroxyvitamin D deficiency with compensatory hyperparathyroidism. During the study period, bone mineral density in the risedronate group increased by 4.1% and decreased by 0.9% in the control group. Vertebral fractures occurred in 29 patients (24 hip fractures) in the control group and 8 patients (5 hip fractures) in the risedronate group. The relative risk in the risedronate group compared with the control group was 0.28 (95% confidence interval, 0.13-0.59). CONCLUSIONS: Elderly patients with AD hypovitaminosis D are at increased risk for hip fracture. Treatment with risedronate and ergocalciferol may be safe and effective in reducing the risk of a fracture in elderly patients with AD.

Accidental Falls↗
PubMedDate not supplied

Risedronate sodium therapy for prevention of hip fracture in men 65 years or older after stroke.

BACKGROUND: There is a high incidence of hip fractures in patients after hemiplegic stroke. Bone mineral density is decreased on the hemiplegic side in patients after stroke, correlating with the immobilization-induced bone resorption, the degree of paralysis, and hypovitaminosis D. The purpose of this study is to evaluate the effectiveness of risedronate sodium, an inhibitor of bone resorption, on osteoporosis and the risk of hip fractures in men 65 years or older after stroke. METHODS: We conducted an 18-month randomized double-blind trial. Of 280 male patients 65 years or older who were poststroke, 140 received a daily dose of 2.5 mg risedronate sodium and the other 140 received placebo. Incidence of hip fractures in the 2 groups was compared. RESULTS: Ten patients sustained hip fractures in the placebo group, and 2 hip fractures occurred in the risedronate group. The relative risk of a hip fracture was 0.19 (95% confidence interval, 0.04-0.89). The number of patients needing the treatment was 16 (95% confidence interval, 9-32). Bone mineral density increased by 2.5% in the risedronate group and decreased by 3.5% in the placebo group (P<.001). Urinary deoxypyridinoline, a bone resorption marker, decreased by 58.7% in the risedronate group and by 37.2% in the placebo group. CONCLUSION: Treatment with risedronate increases bone mineral density and reduces hip fractures in elderly men who are poststroke.

Accidental Falls↗
PubMedDate not supplied

Relationship between radiographic abnormalities of lumbar spine and incidence of low back pain in high school and college football players: a prospective study.

BACKGROUND: Low back pain is a common presenting symptom among players of American football. In Japan, however, skeletal disorders in football players, including low back problems, have been rarely studied, and management to prevent skeletal disorders has not been established. STUDY DESIGN: An epidemiological study with prospective observation. METHODS: The authors analyzed the relationship between lumbar spine abnormalities viewed through radiographs taken during the preparticipation physical examination, and the incidence of low back pain during a 1-year period in 171 high school and 742 college football players. Abnormalities assessed were spondylolysis, disc space narrowing, spinal instability, Schmorl's node, balloon disc, and spina bifida occulta. RESULTS: High school players with spondylolysis had a higher incidence of low back pain (79.8%) than those with no abnormal radiographic results (37.1%). College players with spondylolysis, disc space narrowing, and spinal instability had a higher incidence of low back pain (80.5%, 59.8%, and 53.5%, respectively) than those with no abnormal radiographs (32.1%), and college players with spondylolysis had a higher incidence of low back pain than those with disc space narrowing and spinal instability. CONCLUSIONS: The results of the present study suggest that an abnormality such as spondylolysis is the most significant risk factor for low back pain in high school and college football players, and that disc space narrowing and spinal instability are also significant risk factors for low back pain in athletes with greater athletic activity such as college football players.

Adolescent↗