Osteocytes are suggested to play a central role in bone remodeling. Evaluation of iliac crest biopsies is a standard procedure for evaluating bone conditions in the clinical setting. Despite the widespread use of such biopsies, little is known about the population of osteocytes in the iliac crest from normal individuals.
View Article and Find Full Text PDFUnlabelled: Age-related changes of vertebra and iliac crest 3D microstructure were investigated, and we showed that they were in general similar. The 95th percentile of vertebral trabecular thickness distribution increased with age for women. Surprisingly, vertebral and iliac crest bone microstructure was only weakly correlated (r = 0.
View Article and Find Full Text PDFThe study presents a 3D method for subdividing a trabecular network into horizontal and vertical oriented bone. This method was used to investigate the age related changes of the bone volume fraction and thickness of horizontal and vertical trabeculae in human lumbar vertebral bone estimated with unbiased 3D methods in women and men over a large age-range. The study comprised second lumbar vertebral body bone samples from 40 women (aged 21.
View Article and Find Full Text PDFTwo experiments investigated whether remembering is affected by the similarity of the study face relative to the alternatives in a lineup. In simultaneous and sequential lineups, choice rates and false alarms were larger in low compared to high similarity lineups, indicating criterion placement was affected by lineup similarity structure (Experiment 1). In Experiment 2, foil choices and similarity ranking data for target present lineups were compared to responses made when the target was removed from the lineup (only the 5 foils were presented).
View Article and Find Full Text PDFRape shield laws, which limit the introduction of sexual history evidence in rape trials, challenge the view that women with extensive sexual histories more frequently fabricate charges of rape than other women. The present study examined the relationship between women's actual sexual history and their reporting rape in hypothetical scenarios. Female participants (college students and a community sample, which included women working as prostitutes and topless dancers, and women living in a drug and alcohol rehabilitation center) imagined themselves in dating scenarios that described either a legally definable act of rape or consensual sexual intercourse.
View Article and Find Full Text PDFJ Musculoskelet Neuronal Interact
September 2000
The strength of the spinal trabecular bone declines by a factor of 4-5 from the age of 20 to 80 years. At the same time, the volumetric (apparent) density declines by a factor of only 2. This discrepancy can be explained by the known power relationship between density and strength; this power relationship is based on the fact that trabecular bone is a porous material.
View Article and Find Full Text PDFBone mineral density (BMD) is the principal diagnostic tool used in clinical settings to diagnose and monitor osteoporosis. Experimental studies on ex vivo bone samples from multiple skeletal locations have been used to propose that their breaking stress bears a power-law relationship to volumetric BMD, with a location-dependent index. We argue that a power-law cannot represent effects of trabecular removal, which is one of the leading causes of reduction in bone strength.
View Article and Find Full Text PDFTo investigate whether vertical trabeculae undergo compensatory thickening with age in the human vertebral body, a new computerized method was developed that is able to distinguish between horizontal and vertical trabeculae on normal histological sections. Study subjects included 48 individuals (24 women aged 19-97 years, and 24 men aged 23-95 years). From each L-2, thick frontal sections of half of the vertebra were embedded undecalcified in methylmetacrylate and cut into 10-microm-thick sections.
View Article and Find Full Text PDFWe have previously shown that there are pronounced age-related changes in human vertebral cancellous bone density and microarchitecture. However, the magnitude of these changes seemed to be dependent on zone location in the vertebral body-the central third vs. the areas adjacent to the endplates.
View Article and Find Full Text PDFBackground: Earlier studies on the effect of excess growth hormone (GH) on trabecular bone have been conflicting. Since insulin-like growth factors (IGFs) and their binding proteins (IGFBPs) in part mediate the effects of GH, the present study aimed to investigate trabecular bone composition of these growth factors in relation to biomechanical properties in acromegaly.
Materials And Methods: Trabecular bone biomechanical competence (compression test), apparent density (peripheral quantitative computed tomography, pQCT), and bone matrix contents of calcium (HCl hydrolysis) and IGFs (guanidinium-HCl extraction) were measured in iliac crest biopsies from 13 patients with active acromegaly (two women and 11 men, aged 21-61 years) and 21 age- and sex-matched controls (four women and 17 men, aged 23-64 years).
The study investigates the relationship between static histomorphometry and bone strength of human lumbar vertebral bone. The ability of vertebral histomorphometry to predict vertebral bone strength was compared with that of vertebral densitometry, and also with histomorphometry and bone strength of iliac crest bone biopsies. The material comprised matched sets of second lumbar vertebrae, third lumbar vertebrae, and two iliac crest bone biopsies from each of 21 women (19--96 years) and 24 men (23--95 years).
View Article and Find Full Text PDFIn a prospective, controlled, comprehensive cohort trial of 2,016 healthy early postmenopausal women aged 45-58 years we studied fracture prevention through the use of oestrogen. There were two main study arms: a randomised arm (randomised to HRT [n = 502] or not [n = 504]) and a non-randomised arm (on HRT [n = 221] or not [n = 789] by own choice). After five years, an intention-to-treat analysis (n = 2,016) showed a reduction in the overall fracture risk (RR = 0.
View Article and Find Full Text PDFWe recently developed a new, rapid method for conducting static histomorphometry on large histologic sections. This method has now been applied on both iliac crest and lumbar vertebral bone to compare the age-related changes at these two skeletal sites and to investigate the correlation between the histomorphometric measures at the iliac crest and the vertebral body. The material comprised matched sets of unilateral transiliac crest bone biopsies and lumbar vertebral bodies (L-2) from 24 women (19-96 years) and 24 men (23-95 years) selected from a larger autopsy material.
View Article and Find Full Text PDFAging of the human skeleton is characterized by decreased bone formation and bone mass and these changes are more pronounced in patients with osteoporosis. As osteoblasts and adipocytes share a common precursor cell in the bone marrow, we hypothesized that decreased bone formation observed during aging and in patients with osteoporosis is the result of enhanced adipognesis versus osteoblastogenesis from precursor cells in the bone marrow. Thus, we examined iliac crest bone biopsies obtained from 53 healthy normal individuals (age 30-100) and 26 patients with osteoporosis (age 52-92).
View Article and Find Full Text PDFObjectives: To study the fracture reducing potential of hormonal replacement therapy (HRT) in recent postmenopausal women in a primary preventive scenario.
Methods: Prospective controlled comprehensive cohort trial: 2016 healthy women aged 45-58 years, from three to 24 months past last menstrual bleeding were recruited from a random sample of the background population. Mean age was 50.
The proinflammatory cytokines interleukin-1 beta (IL-1 beta) and IL-6 may play a central role in the acceleration of postmenopausal bone loss, but observational studies have led to contradictory results. Estrogen-dependent changes in the production of IL-1 receptor antagonist (IL-1ra) and the soluble IL-6 receptor (sIL-6R) potentially modify cytokine bioactivity. We therefore assessed the impact of menopause and hormone replacement therapy (HRT) on cytokines and activity modifiers in serum within a 5-year longitudinal study.
View Article and Find Full Text PDFThe aim of the present study was to assess age-related changes in the human spine by use of established static histomorphometry, and to determine how these static histomorphometric measures are interrelated in human cancellous bone tissue. The material comprised normal human lumbar vertebral bodies (L-2) from 12 women (19-96 years) and 12 men (23-91 years) selected from a larger autopsy material to give an even age and gender distribution. In addition, L-2 from three female subjects (80, 88, and 90 years) with a known vertebral fracture of L-2 were considered.
View Article and Find Full Text PDFAging (Milano)
October 1999
This study explores whether regular training alters body composition and resting metabolism in the very old. A total of 55 community-dwelling women, 85 years old, were enrolled in a training group (N = 22) and a control group (N = 33). Training was performed once a week for eight months, and consisted of various exercises with particular attention to movements important for everyday activities.
View Article and Find Full Text PDFBone densitometry with DXA (dual energy X-ray absorptiometry) and QCT (quantitative computed tomography) techniques are used for in vivo assessment of bone strength and thereby prediction of fracture risk. However, only few in vitro studies have investigated and compared these techniques' ability to determine vertebral compressive strength. The aim of the present study was to (1) assess the predictive value of DXA, QCT, and pQCT (peripheral QCT) for vertebral bone compressive strength assessed by mechanical testing; (2) describe both linear and power relationship between density and strength; and (3) evaluate whether gender-related differences in the above relations were present.
View Article and Find Full Text PDFThis study was designed to evaluate age- and gender-related differences in vertebral bone mass, density, and strength by dual-energy X-ray absorptiometry (DXA), quantitative computed tomography (QCT), peripheral QCT (pQCT), ash measurements, and biomechanical testing. The material comprised human lumbar vertebral bodies (L3) from 51 females and 50 males (age-range: 18-96 years). The results showed that females had significantly lower vertebral body bone mass (ash weight) than males at any given age.
View Article and Find Full Text PDFThe metabolism of bone collagen has received little attention in relation to age-related loss of bone mass and strength. The aim of the present study was to analyze bone collagen content and metabolism in human bone with respect to age. The material consisted of iliac crest bone biopsies from 94 individuals: 46 women (ages 18-96, mean age 60.
View Article and Find Full Text PDFJ Clin Endocrinol Metab
January 1999
To investigate cortical bone composition and the role of the insulin-like growth factor (IGF) system in active acromegaly, iliac crest bone biopsies were obtained from 15 patients (3 women and 12 men), aged 21-64 yr (mean, 45.6 yr), and 25 age- and sex-matched controls (8 women and 17 men), aged 22-66 yr (mean, 44.6 yr).
View Article and Find Full Text PDFJ Appl Psychol
October 1998
The effect of varying the retention interval after an interaction with a stranger on the accuracy of memory for events and for personal identifying characteristics at 2 recall attempts was investigated. Although the number of correct event facts that were recalled decayed as expected, the percentage of recalled facts that were in error remained constant over time. In addition, a single recall attempt prevented further decay in the total amount correctly recalled.
View Article and Find Full Text PDFVertebral bone density is evaluated mainly by dual-energy X-ray absorptiometry (DXA) or quantitative computed tomography (QCT). Densitometry is used as an estimator of bone strength and forms the basis for choice of treatment. DXA expresses bone density in grams per square centimeter (area density) and QCT expresses bone density in milligrams per cubic centimeter (volumetric density).
View Article and Find Full Text PDFClin Endocrinol (Oxf)
June 1998
Objective: In rodents, leptin is involved in regulating eating behaviour, fat storage, and reproductive function. In humans, the serum leptin concentration in obese and normal weight subjects correlates with body mass index, reflecting the body fat store. The serum leptin exhibit diurnal variation, however, this has been reported to be absent in normal weighted amenorrheic athletes.
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