Search results for "Bone mineral"
showing 10 items of 180 documents
Weight-bearing, muscle loading and bone mineral accrual in pubertal girls--a 2-year longitudinal study.
2007
Abstract Objectives: The mechanical environment is considered to be the most important determinant of bone strength. Local muscle force, in turn, is regarded as the largest source of loading applied to bones. However, the effect of weight-bearing on bone mineral accrual is unclear. Comparing the relationship between muscle force and bone mineral content (BMC) in the upper and lower limbs provides a means of investigating this issue. Subjects and methods : The study group comprised 258 healthy girls aged 10–13 years old at baseline. BMC, lean body mass (LM) and fat body mass (FM) of total body were assessed by dual-energy X-ray absorptiometry at baseline and 2 years after. The maximal isomet…
A biomechanical evaluation of methods of distal humerus fracture fixation using locking compression plates versus conventional reconstruction plates.
2004
OBJECTIVES To examine the biomechanical behavior of 2 techniques of double-plate osteosynthesis for fractures of the adult distal humerus using conventional reconstruction plates and locking compression plates. DESIGN Basic science study. SETTING Experimental in vitro study. PATIENTS/PARTICIPANTS Forty fresh-frozen human distal humeri specimens. INTERVENTION Four matched groups with 10 humeri each, median age 74 years (46-95), were created using similar bone mineral density values. Two standard configurations of double-plate osteosynthesis (dorsal or 90 degrees configuration) with either conventional reconstruction plates or locking compression plates were studied for biomechanical properti…
Effects of obesity on periodontal tissue remodeling during orthodontic movement.
2021
Made available in DSpace on 2021-06-25T15:01:37Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-04-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) German Research Foundation (DFG) Introduction: Orthodontic movement triggers a sequence of cellular and molecular events that may be affected by different systemic conditions. This study evaluated the effect of obesity on rat periodontal tissue remodeling induced by mechanical orthodontic force. Methods: Thirty-two Holtzman rats were distributed into 4 groups: control, obesity induction (O), orthodontic movement (M), and obesity induction and orthodontic movement (OM). Obesity was induced by a high-fat diet for 90 days. Af…
Current perspectives on parathyroid hormone (PTH) and PTH-related protein (PTHrP) as bone anabolic therapies.
2013
Osteoporosis is characterized by low bone mineral density and/or poor bone microarchitecture leading to an increased risk of fractures. The skeletal alterations in osteoporosis are a consequence of a relative deficit of bone formation compared to bone resorption. Osteoporosis therapies have mostly relied on antiresorptive drugs. An alternative therapeutic approach for osteoporosis is currently available, based on the intermittent administration of parathyroid hormone (PTH). Bone anabolism caused by PTH therapy is mainly accounted for by the ability of PTH to increase osteoblastogenesis and osteoblast survival. PTH and PTH-related protein (PTHrP)-an abundant local factor in bone- interact wi…
Ibandronate: a review of its vertebral and nonvertebral antifracture efficacy.
2009
After the Ibandronate Osteoporosis Vertebral Fracture Trial in North America and Europe (BONE) study had demonstrated the strong vertebral and nonvertebral antifracture efficacy of daily and intermittent oral ibandronate, the Monthly Oral Ibandronate In Ladies (MOBILE) study gave evidence for an increased efficacy on the bone mineral density (BMD) of higher intermittent oral ibandronate doses (150 mg monthly) compared with 2.5 mg daily. The BONE study also observed nonvertebral antifracture efficacy in patients with a high risk for fractures (mean femoral neck T score of −3.0 or less). A recently published meta-analysis assessing the nonvertebral antifracture efficacy corresponding to the …
Associated Factors and Liver Disease Severity for Decreased Bone Mineral Density in HIV Mono- and HIV/HCV Co-infected Patients
2015
Objective: We assessed the prevalence and risk factors of decreased bone mineral density (BMD) in patients mono-infected with human immunodeficiency virus (HIV) or co-infected with hepatitis C virus (HIV/HCV). We also evaluated whether bone loss was linked to lipid asset in both groups and to severity of liver fibrosis in the co-infected group. Methods: We consecutively enrolled 194 HIV-patients (129 mono-infected and 65 co-infected). All HIV-patients underwent dual-energy X-ray absorptiometry (DXA), while co-infected patients underwent transient elastography. Advanced liver fibrosis was defined as a median liver stiffness ≥ 9.5 kPa. Fibrosis was also assessed in all the HIV-patients using …
Response of Bone Metabolism Markers to Ice Swimming in Regular Practitioners
2021
Objective: Both exercise and cold exposure cause physiological stress and they often occur in combination. However, the effects of exercise during severe cold on variation in bone metabolism in humans have remained elusive. The aim of this study was to investigate the variations in circulating bone metabolism markers after ice swimming (IS).Methods: Eighty-seven women and men aged 42–84 years old were recruited to perform regular IS activities. Serum parathyroid hormone (PTH), total calcium (Ca2+), total phosphorus (Pi), total magnesium (Mg2+), N-terminal osteocalcin (N-MID), total propeptide of procollagen 1 (TPINP), and C-terminal telopeptide of type 1 collagen (β-CTX) were measured 30 mi…
Effects of BIS076 in a model of osteoarthritis induced by anterior cruciate ligament transection in ovariectomised rats
2015
Background Osteoarthritis (OA) is the most frequent articular disease and a leading cause of disability. There is a need for effective treatments able to slow the progression of disease. Some of the available treatments are dietary supplements providing natural components. Recent studies have shown that estrogen deficiency contributes to the pathophysiological events of OA progression. Methods We have used the anterior cruciate ligament transection model of OA in ovariectomised rats to study the effects of BIS076, a new formulation of a natural porcine cartilage extract associated with hydroxyapatite (as a source of calcium) and vitamin D3. Cartilage degradation, proteoglycan depletion and …
Influence of long-term postmenopausal hormone-replacement therapy on estimated structural bone strength: A study in discordant monozygotic twins
2010
Although postmenopausal hormone-replacement therapy (HRT) is known to prevent fractures, knowledge on the influence of long-term HRT on bone strength and its determinants other than areal bone mineral density is scarce. This study used a genetically controlled design with 24 monozygotic female twin pairs aged 54 to 72 years in which one cotwin was using HRT (mean duration 8 years) and the other had never used HRT. Estimated bone strength, cross-sectional area, volumetric bone mineral density, bone mineral mass, and cross-sectional density and mass distributions were assessed in the tibial shaft, distal tibia, and distal radius with peripheral computed tomography (pQCT). In the tibial shaft,…
Duration of breastfeeding as a risk factor for vertebral fractures
2014
Abstract Purpose Among the risk factors for osteoporosis and fractures, gynecological history (fertile period, parity and breastfeeding) play an important part. Changes in calcium metabolism to enable an adequate mineral transfer to the milk have a prominent role in bone loss during breastfeeding. Data on the influence of breastfeeding in postmenopausal osteoporosis are inconsistent. The aim of the present study was to identify any association between duration of breastfeeding and vertebral fractures in postmenopausal women. Methods All patients underwent the following tests: bone mineral density measurements of the lumbar spine (L1–L4) and the total and femoral neck using dual-energy X-ray…