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1.
Summary A study of the association between the rate of proliferation of marrow fibroblast-like stromal cells (in vitro) and the rate of endosteal bone mineralization (EsMR) (in vivo) was undertaken in an osteopenic rat model. We report than 200 g male rats treated with cortisone acetate (5 mg/day for 7
days) exhibit decreases in marrow fibroblast colony-forming units (FCFU) and tetracycline-based measurements of EsMR at the
level of the femoral midshaft. In cortisone-treated rats recovering for 1–3 weeks, the FCFU census and EsMR normalized during
the first posttreatment week, remained at control levels after 2–3 weeks, and exhibited a relapse in the third week which
signified only partial recovery. These changes were unrelated to patterns of body weight gain. The data indicate that the
FCFU census can serve to index endosteal osteoblast vigor. 相似文献
2.
Agents for prevention or treatment of osteoporosis must now be tested in a large animal species that exhibits bone remodeling.
Ovariectomized, nonhuman primates provide one such model, and they consistently develop osteopenia accompanied by high bone
turnover rates. The goal of this study was to further characterize this model, and particularly to determine the effect of
ovariectomy on bone strength in vertebrae and femoral necks. Longitudinal evaluations of spinal bone mass and serum markers
of bone turnover were performed in 19 sham-ovariectomized (SHAM) and 18 ovariectomized (OVX), domestically reared cynomolgus
monkeys, aged >9 years. OVX monkeys lost bone relative to both baseline values and SHAM controls. Serum markers of bone turnover
were increased by OVX. After 72 weeks, both vertebral bone compressive strength and femoral neck breaking strength were significantly
decreased in OVX animals compared with SHAM. Ovariectomized cynomolgus monkeys, like postmenopausal women, develop accelerated
bone loss, increased bone turnover, and reduced bone strength, and provide a suitable large animal model for efficacy studies
with agents for prevention or treatment of osteoporosis.
Received: 24 June 1996 / Accepted: 3 September 1996 相似文献
3.
Summary In the rat, prolonged administration of the luteinizing, hormone-releasing hormone agonist buserelin (25 μg/kg body wt/day
s.c.) lowers blood estradiol, raises bone resorption, and induces osteopenia. The present study was undertaken to determine
whether withdrawal of buserelin normalizes blood estradiol, slows bone resorption, and corrects buserelin-mediated osteopenia.
Four groups of female rats with45Ca-labeled bones were studied: group 1A received 0.2 ml saline s.c. daily for 4 weeks; group 2A received 0.2 ml buserelin
s.c. daily for 4 weeks; group 1B received 0.2 ml saline s.c. daily for 8 weeks; group 2B received 0.2 ml buserelin s.c. daily
for 4 weeks followed by 0.2 ml saline s.c. daily for 4 weeks. Bone resorption was monitored by measuring urinary45Ca and hydroxyproline. The rats in groups 1A and 2A were killed after 4 weeks and those in groups 1B and 2B after 8 weeks.
The mineral contents of the femoral bones and the whole skeletons were measured. Buserelin lowered blood estradiol, elevated
urinary45Ca and urinary hydroxyproline, and lowered femur and total body calcium and45Ca in group 2A vs. 1A (P<0.05). By contrast all these measurements became similar in groups 2B and 1B. Thus, osteopenia generated by a 4-week period
of buserelin-mediated hypo-estrogenism is reversible by withdrawing buserelin for 4 weeks. Consequently, buserelin administration
and withdrawal may be used to study effects of inducing and reversing estrogen-deficiency bone loss in the rat. 相似文献
4.
M. L. M. Montessori W. H. Scheele J. C. Netelenbos J. F. Kerkhoff K. Bakker 《Osteoporosis international》1997,7(1):52-58
The purpose of this open, prospective, controlled, randomized trial was to study the effect of intermittent, cyclic etidronate on the bone mass of osteoporotic postmenopausal women with or without fractures. Eligible subjects were asymptomatic women less than 75 years old who had been amenorrhoeic for at least 1 year. Those with secondary osteoporosis were excluded. Subjects also had to be ambulant with a bone mineral density (BMD) of the lumbar spine >1 SD below that of age matched controls (Z-score < –1 SD). Eighty patients were enrolled, of whom 65 were recruited through a screening programme conducted in the practices of two general practitioners. The remaining patients were from other referrals. The subjects were randomized to two groups of 40 women. Treatment regimens were as follows. The etidronate group was treated with etidronate 400 mg once daily for 14 days followed by 76 days of 500 mg of elementary calcium once daily; this cycle was repeated every 3 months. The calcium group took 500 mg of elementary calcium once daily. The groups were not different in age, height, weight, time since menopause, BMD at baseline and prevalent vertebral fractures. In 50 patients (28 in the etidronate group and 22 in the calcium group) no vertebral fractures were present (67%). Sixty-four patients (35 in the etidronate group and 29 in the calcium group) completed the 3 years of the study. In the etidronate group the mean BMD of the lumbar spine, femoral neck, trochanter and Ward's triangle increased by 5.7%, 1.4%, 7.1% and 10.9% from baseline values respectively (p<0.05 at all sites except for the femoral neck). In the calcium group no significant changes from baseline were found at any time point at any site after 3 years, except for the femoral neck, where BMD at 156 weeks decreased significantly by 3% (p<0.003). In 3 patients, all in the calcium group, six new fractures were found. There were no serious adverse effects. We conclude that intermittent, cyclic treatment with etidronate causes a significant increase in the BMD of the lumbar spine and the proximal femur in osteopenic postmenopausal women, and that treatment is safe and has no serious adverse effects. 相似文献
5.
Transforming Growth Factor-β2 mRNA Level in Unloaded Bone Analyzed by Quantitative In Situ Hybridization 总被引:2,自引:0,他引:2
The effects of tail suspension hypokinesia on the gene expression for TGF-β2 at different sites within bone were evaluated. TGF-β2 mRNA signal levels were determined quantitatively by an image analysis system. The osteopenia induced by tail suspension
was verified by histomorphometry. In the periosteum of nonsuspended control rats, TGF-β2 mRNA was highly expressed in the preosteoblasts and osteoblast-rich cambial layers; very little signal was present within
the middle and outer fibroblastic layers. Gene expression was significantly reduced in suspended rats, and this was evident
both in terms of the number of silver grains in unit area or length of tissue and in each osteoblast and preosteoblast. Hypokinesia
also reduced the expression of TGF-β2 mRNA level in cortical and trabecular bone osteocytes, but did not adversely affect the mRNA level in chondrocytes in growth
plate. The results affirm the site-specific response of TGF-β2 gene expression in rats, and suggest that the cortical and trabecular bone osteopenia associated with hypokinesia in rats
may be associated with a deficit in osteoblastic and osteocytic TGF-β2 level.
Received: 6 February 1998 / Accepted: 10 November 1998 相似文献
6.
Nader Roushan Alipasha Meysamie Mohammadreza Managhchi Javad Esmaili Tarane Dormohammadi 《Indian journal of hematology & blood transfusion》2014,30(4):351-355
Patients with hemophilia suffer from low bone mineral density (BMD) due to several risk factors including arthropathy and resulting immobility. Recent studies have shown variable frequency of low BMD in this group of patients. This study attempts to assess the prevalence of low BMD (osteoporosis and osteopenia) and the associated risk factors in a group of Iranian hemophilia patients. Patients with moderate or severe hemophilia underwent BMD measurement by dual energy X-ray absorptiometry. The results were correlated with other variables including physical activity, calcium intake and demographic data. Forty two patients with the mean age of 31 years (range 18–72) completed the study. The prevalence of osteoporosis in the spine and the left femoral neck was 23.8 and 14.6 %, respectively, and osteopenia in the spine and femoral neck was seen in 45.2 and 31.7 % of the patients, respectively based on the WHO T-score criteria. We found only cigarette smoking to be significantly related to low BMD (P < 0.001). There were two cases of pathologic fracture at femoral neck and forearm (4.8 %). Low BMD is very common in patients with hemophilia. Appropriate assessment of BMD and control of predisposing factors such as prophylactic factor replacement (to prevent hemarthrosis) and cessation of cigarette smoking are warranted. 相似文献
7.
Bezza A Ouzzif Z Naji H Achemlal L Mounach A Nouijai M Bourazza A Mossadeq R El Maghraoui A 《Rheumatology international》2008,28(12):1205-1209
Parkinson's disease (PD) is the most common cause of disability in the elderly. It is currently recognized as a cause of secondary osteoporosis. To evaluate the prevalence of osteoporosis in PD and detect its risk factors, 52 patients with PD (36 men/16 women) and 52 controls paired for age and sex were recruited. Clinical data including demography, disease duration and disease severity were collected. All subjects had bone mineral density (BMD) measured by dual energy X-ray absorptiometry, dorsal and lumbar spine X-ray, and biological exams (osteocalcin, CTX, parathormon). The mean age of the patients was 60.0 +/- 9.25 years [30-77], and the mean disease duration was 4.9 +/- 4.5 years [0.2-17]. Nine patients (17.3%) were osteoporotic and 28 (53.8%) osteopenic. BMD at the lumbar spine and the hip was lower among patients than controls (spine: 1.031 vs. 1.175 g/cm(2); P < 0.001; hip: 0.968 vs. 1.054; P = 0.02). PD patients with low BMD presented a more severe disease and an insufficient sun exposure and calcium intake. There was a positive statistically significant correlation between patients BMD and body mass index and negative correlation with age, severity of PD, and osteocalcin levels. The prevalence of osteoporosis/osteopenia is high in PD patients and seems related to the severity of the disease, an insufficient sun exposure and calcium intake. This osteoporosis constitutes with falls the major risk factors of fracture in PD patients. 相似文献
8.
《Actas urologicas espa?olas》2014,38(10):685-693
ContextIn patients with prostate cancer, bone health is compromised by advanced age at diagnosis, androgen suppression treatments and the developmentofbone metastases. In this paper the medical literature is reviewed in order to update the state of the art on their incidence, prevention and management.Evidence acquisitionA literature review about bone involvement in patients with prostate cancer in different clinical settings is performed.Synthesis of the evidenceDecreased bone mineral density is higher in patients diagnosed of prostate cancer before starting treatment than in healthy men with the same age. During the first year of treatment, a severe loss bone density is reported due to androgen suppression therapy. From then on, loss bone density seems to slow down, persisting at long-term. It is important to know the starting point and the dynamics of loss bone in order to prevent its progression. The skeletal events have an important impact on quality of life in patients with prostate cancer. Both Denosumab and Zoledronic Acid have proven effective in reducing loss bone.ConclusionsThe prevention and management of bone involvement in patients with prostate cancer is critical to quality of life in these patients and requires an individualized approach. Before starting a prolonged androgen deprivation, baseline risk of fracture should be evaluated in order to adopt the proper protective measures. In patients with metastases, early treatments reducing the risk of bone events should be taken into account. 相似文献
9.
Babak Pourabbas Tahvildari Mohammad-Ali Erfani Hormoz Nouraei Mohammad Sadeghian 《Clinics in Orthopedic Surgery》2014,6(2):180-184
Background
Several reports have suggested low bone mineral density (BMD) in patients with adolescent idiopathic scoliosis (AIS). We determined bone mineral status in patients with AIS to evaluate the effect of brace treatment on BMD.Methods
BMD was measured in 46 patients (mean age, 17.8 ± 4.9 years) with AIS (17 with brace and 29 without brace) by dual-energy X-ray absorptiometry scan and compared the results to an age-matched (mean age, 16.6 ± 3.9 years) control group (n = 54).Results
The AIS group had significantly lower bone mass at the lumbar spine (Z-score, -1.500 vs. -0.832) and hip (Z-score, -1.221 vs. -0.754) except at the femoral neck. No difference in BMD was found between patients with AIS who used a brace and those who did not.Conclusions
The results confirmed that BMD was low in AIS patients and it was not affected by brace treatment. 相似文献10.