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Full-Text Articles in Engineering
Lumbar Vertebral Density And Mechanical Properties In Aged Ovariectomized Rats Treated With Estrogen And Norethindrone Or Norgestimate, Carla Vanin, Neil Maclusky, Debbie Chachra, Mehran Kasra, Marc Grynpas, Robert Casper
Lumbar Vertebral Density And Mechanical Properties In Aged Ovariectomized Rats Treated With Estrogen And Norethindrone Or Norgestimate, Carla Vanin, Neil Maclusky, Debbie Chachra, Mehran Kasra, Marc Grynpas, Robert Casper
Debbie Chachra
OBJECTIVE: This study was designed to investigate the effects of estrogen alone or combined with two different progestins, norethindrone or norgestimate, on bone density and compressive mechanical properties in an aged rat model.
STUDY DESIGN: Twenty 11-month-old female Sprague-Dawley rats were sham operated (intact control) and 80 wee overiectomized. Three groups of 20 ovariectomized rats were implanted with Silastic silicon rubber (Dow Corning, Midland, Mich.) capsules containing 5% estradiol (wt/wt) in cholesterol. All rats in the intact control (group 1) and the ovariectomized (group 2) and the first of the overiectomized plus estrogen (group 3) groups were injected subcutaneously daily …
Fluoride Treatment Increased Serum Igf-1, Bone Turnover, And Bone Mass, But Not Bone Strength, In Rabbits, C. Turner, L. Garetto, A. Dunipace, W. Zhang, M. Wilson, Marc Grynpas, Debbie Chachra, R. Mcclintock, M. Peacock, G. Stookey
Fluoride Treatment Increased Serum Igf-1, Bone Turnover, And Bone Mass, But Not Bone Strength, In Rabbits, C. Turner, L. Garetto, A. Dunipace, W. Zhang, M. Wilson, Marc Grynpas, Debbie Chachra, R. Mcclintock, M. Peacock, G. Stookey
Debbie Chachra
We hypothesized that fluoride partly acts by changing the levels of circulating calcium-regulating hormones and skeletal growth factors. The effects of oral fluoride on 24 female, Dutch-Belted, young adult rabbits were studied. The rabbits were divided into two study groups, one control and the other receiving about 16 mg fluoride/rabbit/day in their drinking water. After 6 months of fluoride dosing, all rabbits were euthanized and bone and blood samples were taken for analyses. Fluoride treatment increased serum and bone fluoride levels by over an order of magnitude (P < 0.001), but did not affect body weight or the following serum biochemical variables: urea, creatinine, phosphorus, total protein, albumin, bilirubin, SGOT, or total alkaline phosphatase. No skeletal fluorosis or osteomalacia was observed histologically, nor did fluoride affect serum PTH or Vitamin D metabolites (P > 0.4). BAP was increased 37% (P < 0.05) by fluoride; serum TRAP was increased 42% (P < 0.05); serum IGF-1 was increased 40% (P < 0.05). Fluoride increased the vertebral BV/TV by 35% (P …
Differential Effects Of Ovariectomy On The Mechanical Properties Of Cortical And Cancellous Bone In Rat Femora And Vertebrae, Debbie Chachra, J.M. Lee, M. Kasra, Marc Grynpas
Differential Effects Of Ovariectomy On The Mechanical Properties Of Cortical And Cancellous Bone In Rat Femora And Vertebrae, Debbie Chachra, J.M. Lee, M. Kasra, Marc Grynpas
Debbie Chachra
The purpose of this study was to evaluate the effects of ovariectomy on the mechanical properties of bone in the aged Sprague-Dawley rat model of osteoporosis. Eight female rats were sacrificed at the start of the study, at the age of four months. Twenty-four remaining rats were then bilaterally ovariectomized (OVX), and another twenty-four served as controls. Eight rats from each group were sacrificed at five, ten or fifteen weeks. The mean density of L1 vertebral bodies from OVX rats was lower than in their control counterparts, as was the compressive modulus, the ultimate compressive stress and the toughness. The …