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101.
102.
Three years of alendronate treatment results in similar levels of vertebral microdamage as after one year of treatment. 总被引:3,自引:0,他引:3
Three years of daily alendronate treatment increases microdamage in vertebral bone but does not significantly increase it beyond levels of microdamage found after 1 yr of treatment. This suggests microdamage accumulation peaks during the early period of bisphosphonate treatment and does not continue to accumulate with longer periods of treatment. INTRODUCTION: Clinically relevant doses of alendronate increase vertebral microdamage by 4- to 5-fold in skeletally mature beagles after 1 yr of treatment. The goal of this study was to determine whether microdamage would continue to accumulate with 3 yr of alendronate treatment in an intact beagle dog model. MATERIALS AND METHODS: One-year-old female beagles were treated with daily oral doses of vehicle (VEH, 1 ml/kg/d) or alendronate (ALN, 0.2 or 1.0 mg/kg/d) for 3 yr. These ALN doses were chosen to approximate, on a milligram per kilogram basis, those used to treat osteoporosis (ALN0.2) and Paget's disease (ALN1.0). Microdamage accumulation, static and dynamic histomorphometry, densitometry, and mechanical properties of lumbar vertebrae were assessed. Comparisons were made among the three groups treated for 3 yr and also within each treatment group to animals treated under the same conditions for 1 yr. RESULTS: Overall microdamage accumulation (crack surface density) was not significantly higher in animals treated for 3 yr with either dose of ALN, whereas crack density increased significantly (100%; p < 0.05) with the higher dose of ALN compared with VEH. Both ALN doses significantly suppressed the rate of bone turnover (-60% versus VEH). There was no difference among groups for any of the structural biomechanical properties-ultimate load, stiffness, or energy absorption. However, when adjusted for areal BMD, ALN-treated animals had significantly lower energy absorption (-20%) compared with VEH. Toughness, the energy absorption capacity of the bone tissue, was significantly lower than VEH for both ALN0.2 (-27%) and ALN1.0 (-33%). Compared with animals treated for 1 yr, there was no significant difference in microdamage accumulation for either ALN dose. VEH-treated animals had significantly lower bone turnover (-58%) and significantly higher levels of microdamage (+300%) compared with values in 1-yr animals. Toughness was significantly lower in animals treated for 3 yr with ALN1.0 (-18%) compared with animals treated for 1 yr, whereas there was no difference in toughness between the two treatment durations for either VEH or ALN0.2. CONCLUSIONS: Although 3 yr of ALN treatment resulted in higher microcrack density in vertebral trabecular bone compared with control dogs, the amount of microdamage was not significantly higher than animals treated for 1 yr with similar doses. This suggests that bisphosphonate-associated increases in microdamage occur early in treatment. Because toughness continued to decline significantly over 3 yr of treatment at the higher ALN dose, decreases in toughness are probably not dependent on damage accumulation. 相似文献
103.
Thyroid-stimulating hormone restores bone volume, microarchitecture, and strength in aged ovariectomized rats. 总被引:2,自引:0,他引:2
T Kuber Sampath Petra Simic Rebecca Sendak Natasa Draca Ann E Bowe Stephen O'Brien Susan C Schiavi John M McPherson Slobodan Vukicevic 《Journal of bone and mineral research》2007,22(6):849-859
We show the systemic administration of low levels of TSH increases bone volume and improves bone microarchitecture and strength in aged OVX rats. TSH's actions are mediated by its inhibitory effects on RANKL-induced osteoclast formation and bone resorption coupled with stimulatory effects on osteoblast differentiation and bone formation, suggesting TSH directly affects bone remodeling in vivo. INTRODUCTION: Thyroid-stimulating hormone (TSH) receptor haploinsufficient mice with normal circulating thyroid hormone levels have reduced bone mass, suggesting that TSH directly affects bone remodeling. We examined whether systemic TSH administration restored bone volume in aged ovariectomized (OVX) rats and influenced osteoclast formation and osteoblast differentiation in vitro. MATERIALS AND METHODS: Sprague-Dawley rats were OVX at 6 months, and TSH therapy was started immediately after surgery (prevention mode; n = 80) or 7 mo later (restoration mode; n = 152). Hind limbs and lumbar spine BMD was measured at 2- or 4-wk intervals in vivo and ex vivo on termination at 8-16 wk. Long bones were subjected to microCT, histomorphometric, and biomechanical analyses. The direct effect of TSH was examined in osteoclast and osteoblast progenitor cultures and established rat osteosarcoma-derived osteoblastic cells. Data were analyzed by ANOVA Dunnett test. RESULTS: In the prevention mode, low doses (0.1 and 0.3 microg) of native rat TSH prevented the progressive bone loss, and importantly, did not increase serum triiodothyroxine (T3) and thyroxine (T4) levels in aged OVX rats. In restoration mode, animals receiving 0.1 and 0.3 microg TSH had increased BMD (10-11%), trabecular bone volume (100-130%), trabecular number (25-40%), trabecular thickness (45-60%), cortical thickness (5-16%), mineral apposition and bone formation rate (200-300%), and enhanced mechanical strength of the femur (51-60%) compared with control OVX rats. In vitro studies suggest that TSH's action is mediated by its inhibitory effects on RANKL-induced osteoclast formation, as shown in hematopoietic stem cells cultivated from TSH-treated OVX rats. TSH also stimulates osteoblast differentiation, as shown by effects on alkaline phosphatase activity, osteocalcin expression, and mineralization rate. CONCLUSIONS: These results show for the first time that systemically administered TSH prevents bone loss and restores bone mass in aged OVX rats through both antiresorptive and anabolic effects on bone remodeling. 相似文献
104.
Clinical risk factors for fractures in multi-ethnic women: the Women's Health Initiative. 总被引:1,自引:0,他引:1
Jane A Cauley Lieling Wu Nina S Wampler Janice M Barnhart Matthew Allison Zhao Chen Rebecca Jackson John Robbins 《Journal of bone and mineral research》2007,22(11):1816-1826
To identify risk factors for fractures in multi-ethnic women, we studied 159,579 women enrolled in the Women's Health Initiative. In general, risk factors for fractures were similar across ethnic groups. However, irrespective of their ethnicity, women with multiple risk factors have a high risk of fracture. Targeting these high-risk women for screening and intervention could reduce fractures. INTRODUCTION: Fracture rates tend to be lower in minority women, but consequences may be greater. In addition, the number of fractures is expected to increase in minority women because of current demographic trends. There are limited prospective data on risk factors for fractures in minority women. MATERIALS AND METHODS: We studied 159,579 women 50-79 yr of age enrolled in the Women's Health Initiative. Information on risk factors was obtained by questionnaire or examination. Nonspine fractures that occurred after study entry were identified over an average follow-up of 8 +/- 2.6 (SD) yr. RESULTS: Annualized rates (%) of fracture in whites, blacks, Hispanics, Asians, and American Indians were 2.0, 0.9, 1.3, 1.2, and 2.0, respectively. Significant predictors [HR (95% CI)] of fractures by ethnic group were as follows: blacks: at least a high school education, 1.22 (1.0, 1.5); (+) fracture history, 1.7 (1.4, 2.2); and more than two falls, 1.7 (1.9, 2.0); Hispanics: height (>162 cm), 1.6 (1.1, 2.2); (+) fracture history, 1.9 (1.4, 2.5); more than two falls, 1.8 (1.4, 2.3); arthritis, 1.3 (1.1, 1.6); corticosteroid use, 3.9 (1.9, 8.0); and parental history of fracture, 1.3 (1.0, 1.6); Asians: age (per 5 yr), 1.2 (1.0, 1.3); (+) fracture history, 1.5 (1.1, 2.0); current hormone therapy (HT), 0.7 (0.5, 0.8); parity (at least five), 1.8 (1.1, 3.0); more than two falls, 1.4 (1.1, 1.9); American Indian: (+) fracture history, 2. 9 (1.5, 5.7); current HT, 0.5 (0.3, 0.9). Women with eight or more risk factors had more than a 2-fold higher rate of fracture compared with women with four or fewer risk factors. Two ethnicity x risk factor interactions were identified: age and fall history. CONCLUSIONS: Irrespective of their ethnicity, women with multiple risk factors have a high risk of fracture. Targeting these high-risk women for screening and intervention could reduce fractures. 相似文献
105.
106.
Erinn T Rhodes Jonathan A Finkelstein Richard Marshall Carole Allen Matthew W Gillman David S Ludwig 《Ambulatory Pediatrics》2006,6(2):110-114
OBJECTIVE: The American Diabetes Association (ADA) recommends screening children at risk for type 2 diabetes with a fasting plasma glucose test or an oral glucose tolerance test. The purpose of this study was to describe attitudes, barriers, and practices related to type 2 diabetes screening in children among pediatric clinicians. METHODS: Pediatricians, nurse practitioners and physician assistants from a multispecialty, group practice in Eastern Massachusetts completed a mailed survey. To assess screening practice, three vignettes were presented representing pediatric patients with low, moderately high, and high risk for type 2 diabetes. The moderately high-risk and high-risk patients met ADA criteria for screening. ADA-consistent practice was defined as only screening the moderately high-risk and high-risk patients; lower-threshold practice was defined as also screening the low-risk patient; and higher threshold practice was screening only the high-risk patient. RESULTS: Sixty-two of 90 clinicians responded (69%). Based on intent to screen in the 3 vignettes, 21% of respondents reported ADA-consistent screening practice, 39% lower-threshold, and 35% higher-threshold screening practice. Five percent had incomplete or nonclassifiable responses. Many clinicians ordered screening tests other than those recommended by the ADA; few (< or =8% in any vignette) ordered only an ADA-recommended test. Preferences for nonfasting tests were influenced by nonmedical factors such as access to or cost of transportation. Inadequate patient education materials and unclear recommendations for appropriate screening methods were the most frequently reported moderate/strong barriers to screening. CONCLUSIONS: Most respondents reported type 2 diabetes screening practices that differed from current ADA recommendations. Our findings suggest that type 2 diabetes screening tests must be practical for clinicians and patients if they are to be used in pediatric practice. Further study of the benefits and cost-effectiveness of type 2 diabetes screening in children is warranted to clarify the role and optimal methods for screening in pediatric primary care. 相似文献
107.
108.
Rebecca M. Schwartz PhD Edmond S. Malka Michael Augenbraun Steven Rubin Matthew Hogben Nicole Liddon William M. McCormack Tracey E. Wilson 《Journal of urban health》2006,83(6):1095-1104
Efforts to control chlamydial and gonococcal infections include notifying eligible sexual partners of possible infection,
primarily by asking the diagnosed patient to notify their partners. This approach, known as patient referral, is widely used
but poorly understood. The current study examined psychosocial and cognitive factors associated with patient referral among
an urban, minority sample of 168 participants recently diagnosed with Chlamydia trachomatis or Neisseria gonorrhoeae. At a follow-up interview 1-month from diagnosis, participants were more likely to have notified all eligible partners if
they had greater intention to notify at baseline (OR = 3.72; 95% CI = 1.34, 10.30) and if they had only one partner at baseline
(OR = 4.08; 95% CI = 1.61, 10.31). There were also gender differences as well as differences based on type of partner (i.e.,
regular, casual, one-time). The implications of these findings for the design of programs to promote patient referral for
sexually transmitted infections are discussed.
Schwartz, Malka, Augenbraun, McCormack, and Wilson are with the State University of New York, Downstate Medical Center, Brooklyn,
NY, USA; Rubin is with the New York City Department of Health, Bureau of STD Control, New York, NY, USA; Rubin, Hogben, and
Liddon are with the Centers for Disease Control and Prevention, Atlanta, GA, USA; Schwartz is with the Department of Preventive
Medicine and Community Health, SUNY Downstate Medical Center, Box 1240, 450 Clarkson Avenue, Brooklyn, NY 11203, USA. 相似文献
109.
Shelley Allen Glenys Carlson Tamara Ownsworth Jenny Strong 《Australian Occupational Therapy Journal》2006,53(4):293-301
Aim: To present an evidence-based framework to improve the quality of occupational therapy expert opinions on work capacity for litigation, compensation and insurance purposes.
Methods: Grounded theory methodology was used to collect and analyse data from a sample of 31 participants, comprising 19 occupational therapists, 6 medical specialists and 6 lawyers. A focused semistructured interview was completed with each participant. In addition, 20 participants verified the key findings.
Results: The framework is contextualised within a medicolegal system requiring increasing expertise. The framework consists of (i) broad professional development strategies and principles, and (ii) specific strategies and principles for improving opinions through reporting and assessment practices.
Conclusions: The synthesis of the participants' recommendations provides systematic guidelines for improving occupational therapy expert opinion on work capacity. 相似文献
Methods: Grounded theory methodology was used to collect and analyse data from a sample of 31 participants, comprising 19 occupational therapists, 6 medical specialists and 6 lawyers. A focused semistructured interview was completed with each participant. In addition, 20 participants verified the key findings.
Results: The framework is contextualised within a medicolegal system requiring increasing expertise. The framework consists of (i) broad professional development strategies and principles, and (ii) specific strategies and principles for improving opinions through reporting and assessment practices.
Conclusions: The synthesis of the participants' recommendations provides systematic guidelines for improving occupational therapy expert opinion on work capacity. 相似文献
110.