Calcified tissue international
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Calcif. Tissue Int. · Jan 2007
The effect of interleukin-1alpha polymorphisms on bone mineral density and the risk of vertebral fractures.
Interleukin-1alpha (IL-1alpha) stimulates bone resorption via osteoclasts. Mononuclear cells from patients with osteoporosis show increased IL-1alpha production, and IL-1alpha mRNA is more often detected in bone biopsies from osteoporotic compared to normal postmenopausal women. Polymorphisms have been identified in the IL-1alpha gene; however, none of these has been examined for an effect on bone phenotypes in Caucasians. ⋯ None of the other polymorphisms or haplotypes was associated with fracture risk or BMD T score <-2.5. BMD and bone turnover were not associated with any of the genetic variants. In conclusion, all the polymorphisms within the IL-1alpha gene are in strong linkage disequilibrium and not convincingly associated with fracture risk, BMD, or bone turnover.
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Calcif. Tissue Int. · Dec 2006
Additional weight bearing during exercise and estrogen in the rat: the effect on bone mass, turnover, and structure.
Mechanical loading and estrogen play important roles in bone homeostasis. The aim of this study was to evaluate the effects of mechanical loading on trabecular bone in the proximal femur of ovariectomized rats. We hypothesized that mechanical loading suppresses bone resorption and increases bone formation, which differs from the suppressive effects of estrogen on both resorption and formation. ⋯ The results confirm that estrogen suppresses both bone resorption and bone formation in the proximal metaphysis in the femoral head of our rat-with-backpack model. The effects of mechanical loading on the trabecular bone of the femoral head were not significant. This study suggests that the effect of mechanical loading in the rat-with-backpack model mainly occurs at cortical bone sites.
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Calcif. Tissue Int. · Feb 2006
Comparative StudyMortality rates of patients with a hip fracture in a southwestern district of Greece: ten-year follow-up with reference to the type of fracture.
Increased mortality after a hip fracture has been associated with age, sex, and comorbidity. In order to estimate the long-term mortality with reference to hip fracture type, we followed 499 patients older than 60 years who had been treated surgically for a unilateral hip fracture for 10 years. At admission, patients with femoral neck fractures (n = 172) were 2 years younger than intertrochanteric patients (77.6 +/- 7.7 [SD] vs. 79.9 +/- 7.4 [SD], P = 0.001) and had a greater prevalence of heart failure (57% vs. 40.3%, P = 0.03). ⋯ Age, sex, the type of fracture, and the presence of heart failure were independent predictors of 10-year mortality (Cox regression model P < 0.0001). The intertrochanteric type was independently associated with 1.37 (95% CI 1.03-1.83) times higher probability of death at 10 years (P = 0.002). In conclusion, the type of fracture is an independent predictor of long-term mortality in patients with hip fractures, and the intertrochanteric type yields worse prognosis.
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Calcif. Tissue Int. · Sep 2005
Bone remodeling at the iliac crest can predict the changes in remodeling dynamics, microdamage accumulation, and mechanical properties in the lumbar vertebrae of dogs.
We previously demonstrated that suppression of bone remodeling allows microdamage to accumulate, thereby leading to reduced bone toughness in dog bone. In this study we evaluated the relationships between bone remodeling at the iliac crest and skeletal activation frequency, microdamage accumulation, or biomechanical properties of lumbar vertebrae using the same dogs to determine whether bone remodeling at the iliac crest can predict damage accumulation and mechanical parameters of the lumbar spine following treatment with antiresorptive agents. Thirty-six female beagles, 1 to 2 years old, were divided into three groups. ⋯ Dn at a faster rate in L3 than in the iliac crest. Although bisphosphonate treatment decreased bone toughness in L4, this decrease demonstrated no relationship to decreased Ac.f in the ilium. These results clearly indicate that bone remodeling data obtained from iliac crest biopsy could be used to estimate the activation frequency and microdamage burden in the vertebral column.
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Calcif. Tissue Int. · May 2005
Analysis of bone mineral content in horizontally HIV-infected children naïve to antiretroviral treatment.
Low bone mass is a frequent finding in HIV-infected individuals. Reduced bone mass has been found in vertically infected children who are receiving antiretroviral treatment. Little is known about bone mass in horizontally infected young patients who are naïve to antiretroviral therapy. ⋯ In both cases the differences were not significant. The duration of HIV infection did not relate to BMC values. In conclusion, horizontally HIV-infected children naïve to antiretroviral therapy have bone mineral measurements comparable to those of healthy children.