Rapid loss of bone mass and strength in mice after abdominal irradiation

Localized irradiation is a common treatment modality for malignancies in the pelvic-abdominal cavity. We report here on the changes in bone mass and strength in mice 7-14 days after abdominal irradiation. Male C57BL/6 mice of 10-12 weeks of age were given a single-dose (0, 5, 10, 15 or 20 Gy) or fractionated (3 Gy × 2 per day × 7.5 days) X rays to the abdomen and monitored daily for up to 14 days. A decrease in the serum bone formation marker and ex vivo osteoblast differentiation was detected 7 days after a single dose of radiation, with little change in the serum bone resorption marker and ex vivo osteoclast formation. A single dose of radiation elicited a loss of bone mineral density (BMD) within 14 days of irradiation. The BMD loss was up to 4.1% in the whole skeleton, 7.3% in tibia, and 7.7% in the femur. Fractionated abdominal irradiation induced similar extents of BMD loss 10 days after the last fraction: 6.2% in the whole skeleton, 5.1% in tibia, and 13.8% in the femur. The loss of BMD was dependent on radiation dose and was more profound in the trabecula-rich regions of the long bones. Moreover, BMD loss in the total skeleton and the femurs progressed with time. Peak load and stiffness in the mid-shaft tibia from irradiated mice were 11.2-14.2% and 11.5-25.0% lower, respectively, than sham controls tested 7 days after a single-dose abdominal irradiation. Our data demonstrate that abdominal irradiation induces a rapid loss of BMD in the mouse skeleton. These effects are bone type- and region-specific but are independent of radiation fractionation. The radiation-induced abscopal damage to the skeleton is manifested by the deterioration of biomechanical properties of the affected bone.     

Krapina 1: a juvenile Neandertal from the early late Pleistocene of Croatia

The juvenile A Skull from Krapina, Croatia (Krapina 1) has been the subject of considerable debate since B. Skerlj first suggested that it might not be a Neandertal. Although widely known by its original designation, the Krapina A Skull was recatalogued, along with all of the Krapina hominids, in the 1980's (Radovcic, et al., [1988]. The Krapina Hominids: An Illustrated Catalog of Skeletal Collection. Zagreb; Mladost). It is now catalogued as Krapina 1 in the archives of the Hrvatski Prirodoslovni Muzej, Zagreb, Croatia. We present a detailed, morphometric analysis of this specimen, comparing it to other Krapina specimens, juvenile late Pleistocene hominids (including Neandertals), and subadult recent humans. This analysis demonstrates that Krapina 1 possesses morphological features that are primitive retentions; others that represent derived Neandertal specializations; and still others that are typical for all European late Pleistocene humans. Morphological features associated with the browridges are intermediate between Neandertal and early modern European form. Nevertheless, a thorough analysis of the morphology of this specimen, in ontogenetic and regional contexts, leads to the conclusion that it cannot be excluded from the Neandertal range of variation. We conclude that the most parsimonious explanation for this 130 ka specimen is that it should be regarded as a Neandertal.     

Influence of the menopause and aging on spinal density in French women

Dual photon absorptiometry (DPA) was used to measure the bone mineral density (BMD) of the lumbar spine in 510 normal women from the south of France. Long-term precision was 2.2%. BMD was stable in young adults and again in women over 70 years of age. Perimenopausal women at an average age of 51 years already evidenced a slight bone diminution (5%) compared to young adults and women within 2 years of the menopause already had a 10% diminution. The average rate of apparent bone loss in this cross-sectional study was 1% per year from age 45 to 65 years, but about 75% of this decrease occurred in the first decade after the menopause. Spinal BMD in our normal French population appears to be 5–10% lower than US values.     

DEXA analysis on the bones of rats exposed in utero and neonatally to static and 50 Hz electric fields

Effects of the electromagnetic fields on living bodies, bones in particular, are among the relevant issues of contemporary life. In this study, we report the influences of 50 Hz and 0 Hz (static) electric fields (EF), on intact rat bones, as evaluated by dual energy X-ray absorbtion (DEXA) measurements on bone content and density when these animals (n = 27) are continuously exposed in utero and neonatally to EFs (10 kV/m) 14 days before and 14 days after their birth, for 28 days in total. Differences between 50 Hz EF and static EF groups are found to be significant (95% confidence level) for total bone mineral content (BMC), TBMC (P = .002). Differences between 50 Hz and control groups are found to be significant for total bone mineral density (BMD), TBMD (P = .002), lumbar BMC, LBMC (P = .023), and TBMC (P = .001). Differences between static EF and control groups are found to be significant for femoral BMD, FBMD (P = .009), TBMD (P = .002), LBMC (P = .001), and TBMC (P = .001). Note that TBMC parameters are jointly significant for all differences between the three groups of test animals. These results have shown that both static and 50 Hz EFs influence the early development of rat bones. However, the influence of static EFs is more pronounced than that of the 50 Hz field.     

Age-related changes of bone mineral density in human calcaneus, talus, and scaphoid bone

To examine whether the bone mineral density (BMD) decreases uniformly with aging in any spongy bones, the authors investigated age-related changes of BMD in the calcaneus, talus, and scaphoid bone. After the ordinary dissection by medical students was finished, calcanei, tali, and scaphoid bones were resected from the subjects, and BMDs were measured by dual-energy X-ray absorptiometry. Their BMDs seemed to decrease gradually with aging in the calcanei, tali, and scaphoid bones. It was found that there were statistically significant relationships between age and BMD in the men’s and women’s scaphoid bones, women’s tali, and women’s calcanei, but not in the men’s tali and calcanei. It should be noted that there were significant relationships between age and BMD in both men’s and women’s scaphoid bones. In regard to relationship in BMD between the bones of the upper and lower limbs in individuals, it was found that the relationship between the calcaneus and talus was higher than that between the calcaneus and scaphoid bone. This suggests that there is a higher relationship in BMD between the two tarsal bones compared with that between the tarsal and carpal bones.     

Adaptations to free-fall impact are different in the shafts and bone ends of rat forelimbs.

Impact exercise can have beneficial effects on the growing skeleton. To understand what changes it promotes in the shafts and ends of weight-bearing bones, we measured the effects of impact from repetitive free falls in growing rats. Fischer 344 female rats, 6.5 wk old, were assigned to one of three groups (n = 10 each). Controls were not dropped, whereas those subjected to impact were dropped from 30 or 60 cm. Rats in both free-fall groups were dropped 10 times per day for 8 wk. Leg bones were mechanically tested, and their cross-sectional area (CSA), cross-sectional moments of inertia, and volumetric bone mineral density (BMD) were measured by peripheral quantitative computed tomography. In the shafts of the forelimbs, but not the hindlimbs, free-fall impact resulted in greater ultimate breaking force, minimum and maximum second moments of area, and CSA but not BMD. In the bone ends of the forelimb and tibial bones, trabecular BMD increased but CSA did not. Landing from 30 and 60 cm produced peak impact forces of 12.0 and 16.7 times the standing forefoot weight for each front leg and of 4.5 and 7.7 times the standing hind foot weight for each hind foot. Overall, free-fall impact affected the forelimbs by increasing trabecular bone density in the bone ends and improving the strength at the shaft as a result of geometric improvements. These results indicate that adaptation to impact may occur by different mechanisms in bone end and shaft regions.     

Bone mineral density, osteopenia, and osteoporosis in the rhesus macaques of Cayo Santiago

This cross-sectional study investigates metabolic bone disease and the relationship between age and bone mineral density (BMD) in males and females of a large, well-documented skeletal population of free-ranging rhesus monkeys (Macaca mulatta), from the Caribbean Primate Research Center Museum collection from Cayo Santiago, Puerto Rico. The sample consists of 254 individuals aged 1.0-20+ years. The data consist of measurements of bone mineral content and bone mineral density, obtained from dual-energy X-ray absorptiometry (DEXA), of the last lumbar vertebra from each monkey. The pattern of BMD differs between male and female rhesus macaques. Females exhibit an initial increase in BMD with age, with peak bone density occurring around age 9.5 years, and remaining constant until 17.2 years, after which there is a steady decline in BMD. Males acquire bone mass at a faster rate, and attain a higher peak BMD at an earlier age than do females, at around 7 years of age, and BMD remains relatively constant between ages 7-18.5 years. After age 7 there is no apparent effect of age on BMD in the males of this sample; males older than 18.5 years were excluded due to the presence of vertebral osteophytosis, which interferes with DEXA. The combined frequency of osteopenia and osteoporosis in this population is 12.4%. BMD values of monkeys with vertebral wedge fractures are generally higher than those of virtually all of the nonfractured osteopenic/osteoporotic individuals, thus supporting the view that BMD as measured by DEXA is a useful but imperfect predictor of fracture risk, and that low BMD may not always precede fractures in vertebral bones. Other factors such as bone quality (i.e., trabecular connectivity) should also be considered. The skeletal integrity of a vertebra may be compromised by the loss of key trabeculae, resulting in structural failure, but the spine may still show a BMD value within normal limits, or within the range of osteopenia.     

Effect of puberty on the relationship between bone markers of turnover and bone mineral density in Turner's syndrome

It has been suggested that the appropriate timing of puberty is necessary for normal bone mineral acquisition which may not be achieved amongst patients with Turner's syndrome (TS). The aim of this study was to assess bone mineral density (BMD) and bone turnover in 34 patients with TS (age range 2.2-39.0 years). The areal BMD (aBMD) was determined by dual-energy X-ray absorptiometry, and the volumetric BMD was calculated. Blood and second voided urine samples were taken the morning after an overnight fast for evaluation of the biochemical markers of bone turnover: bone-specific alkaline phosphatase (BAP) and N-telopeptides of type I collagen (NTX), respectively. Both were determined by enzyme-linked immunosorbent assay. The patients were divided into three groups: group 1 (n = 13; prepubertal; age range 2.2-19.0 years), group 2 (n = 10; teenagers; age range 12.4-19.0 years), and group 3 (n = 11; adults; chronological age >20 years). They were also grouped by breast development according to Tanner stage into B1 (n = 12), B2-3 (n = 9), and B4-5 (n = 13). The aBMD was significantly lower in group 1 and was higher at Tanner stages 4 and 5 as compared with patients at Tanner stage 1. The bone turnover markers were significantly higher in group 1 (NTX: p = 0.002; BAP: p = 0.0005) and declined, as puberty progressed. A negative correlation was observed between aBMD and biochemical bone markers at the lumbar spine (NTX: r = -0.54, p = 0.05; BAP: r = -0.44, p = 0.01) and in the whole body (NTX: r = -0.60, p = 0.0008; BAP: r = -0.19, p = 0.002). We conclude that the negative relationships between aBMD and biochemical markers suggest a high bone turnover, mainly in prepubertal patients and that the results observed in relation to aBMD and puberty are imputed to the delayed puberty which occurs amongst TS patients.     

Bone Mineral Density and Elemental Composition of Bone Tissues in “Red-Boned” Guishan Goats

Red-colored bones were first found in Guishan goats in the 1980s, and they were subsequently designated red-boned Guishan goats. However, the difference remains unclear between the bone mineral density (BMD) or elemental composition in bones between red-boned Guishan goats and common Guishan goats. Analysis of femoral bone samples by dual-energy X-ray absorptiometry and inductively coupled plasma optical emission spectrometry revealed an increase in bone mineral density in the femoral diaphysis and distal femur of red-boned Guishan goats at 18 and 36?months of age. The data revealed that BMD increased in both the red-boned and common Guishan goats from 18 to 36?months of age. The data also indicated that the ratio of the BMD values of red-boned to common Guishan goats was higher at 36?months of age than they were at 18?months of age. Furthermore, the levels of calcium, phosphorus, magnesium, barium, zinc, manganese, and aluminum were significantly higher in red-boned Guishan goats than common Guishan goats at 18 and 36?months of age. The results indicate that the red-boned Guishan goats were linked to the elevated levels of mineral salts observed in the bones and that this in turn may be linked to the elevated BMD levels encountered in red-boned Guishan goats. These reasons may be responsible for the red coloration in the bones of red-boned Guishan goats.     

Relationships between anthropometric, body composition and bone mineral parameters in 7-8-year-old rhythmic gymnasts compared with controls

The aim of the study was to investigate the relationships between specific anthropometric (9 skinfolds, 13 girths, 8 lengths and 8 breadths), body composition (body fat %, fat free mass [FFM], fat mass [FM]) parameters and bone mineral parameters (bone mineral density [BMD], bone mineral content [BMC) in young rhythmic gymnasts and same age controls. Eighty nine 7-8-year-old girls participated in this study and were divided to the rhythmic gymnast's (n = 46) and control (n = 43) groups. Body composition was determined by dual energy X-ray absorptiometry (FFM, FM, body fat %, BMD and BMC). Body fat % and FM were lower and BMD and BMC values at lumbar spine (L2-L4) and femoral neck were higher in rhythmic gymnasts compared with controls. All measured skinfold thicknesses were thicker in controls. In girths, lengths and widths there were only few significant differences between the groups. Stepwise multiple regression analysis indicated that skinfold thicknesses (supraspinale and medial calf) influenced L2-L4 BMD only in controls 38.2% (R2x100). Supraspinale and iliac crest skinfold thicknesses characterised L2-L4 BMC 43.9% (R2x100). Calf girths influenced BMD in L2-L4 52.3% (R2x100) in controls. BMC in L2-L4 was dependent only on mid-thigh girths 35.9% (R2x100). BMD in L2-L4 was dependent on tibiale-laterale height 30.0% (R2x100). Biiliocristal breadths together with sitting height characterised BMC in L2-L4 BMD 62.3% (R2x100). In conclusion, we found that the relationships between anthropometry, body composition and bone parameters in young rhythmic gymnasts are weak. In control group first of all lower body anthropometric parameters significantly correlated with BMD and BMC in spine.     

Height and Bone Mineral Density Are Associated with Naevus Count Supporting the Importance of Growth in Melanoma Susceptibility

Naevus count is the strongest risk factor for melanoma. Body Mass Index (BMI) has been linked to melanoma risk. In this study, we investigate the link between naevus count and height, weight and bone mineral density (BMD) in the TwinsUK cohort (N = 2119). In addition we adjusted for leucocyte telomere length (LTL) as LTL is linked to both BMD and naevus count. Naevus count was positively associated with height (p = 0.001) but not with weight (p = 0.187) despite adjusting for age and twin relatedness. This suggests that the previously reported melanoma association with BMI may be explained by height alone. Further adjustment for LTL did not affect the significance of the association between height and naevus count so LTL does not fully explain these results. BMD was associated with naevus count at the spine (coeff 18.9, p = 0.01), hip (coeff = 18.9, p = 0.03) and forearm (coeff = 32.7, p = 0.06) despite adjusting for age, twin relatedness, weight, height and LTL. This large study in healthy individuals shows that growth via height, probably in early life, and bone mass are risk factors for melanoma via increased naevus count. The link between these two phenotypes may possibly be explained by telomere biology, differentiation genes from the neural crests but also other yet unknown factors which may influence both bones and melanocytes biology.     

Long-term exposure to solar ultraviolet radiation as a risk factor for age-related macular degeneration

A clinical epidemiological study has been conducted as apart of research project investigating chronic exposure to solar ultraviolet radiation (UVR) as a factor contributing to the onset of age-related macular degeneration (ARMD). The study included 623 subjects older than 50 from two different geographic areas, one with high solar radiation (the island of Solta - Region 1) and the other (Zagreb and its surroundings - Region 2) with low solar radiation. Individual exposure to UVR was assessed according to global exposure to sunlight, on the basis detailed history of life-long exposure to sunlight, with special reference to professional history and geophysical specificities of the respective areas. Different grades of ARMD were based on the fundus photographs and flourescein angiography. Statistically significant relation was found between ARMD and mean daily exposure (in hours) to solar radiation in Region 1 (chi2 = 186.22; p = 0.000), Region 2 (chi2 = 25.66; p = 0.000) and in both regions together (chi2 = 216.43; p = 0.000). ARMD is more frequent in the subjects belonging to the Region 1 and with the same exposure to sunlight (8 hours and more) which goes in favor of their increased UVR exposure. The results support a relationship between long-term sunlight exposure and increased risk of ARMD.     

Age-related changes of vertebral bone mineral density in Russian population]

Vertebral trabecular bone mineral density (BMD) was measured by quantitative computed tomography (QCT) in 1061 subjects (610 females and 451 males aged from 7 to 91 and from 12 to 89, respectively) with known history of diseases or taking medicines affecting bone metabolism. Peak BMD values in our patients were observed at the age of 20-29 years with further gradual decrement in men and more steep in women. Negative relationship between BMD and age was r = -0.991 for men and r = -0.968 for women. Analyzing BMD changes by decades we observed the largest decrement in men after 60 (13.1% for 60-69 and 14.1% for 70-79 years of age) and in women after 50 (22.5% for 50-59, 22.1% for 60-69 and 20.8% for 70-79 years) which was most probably due to decline in sex hormones production that is known to significantly influence bone metabolism. This was confirmed by BMD values three-phase approximation in women showing the lowest rate of calcium loss by trabecular bone in reproductive period (1.9 mg/cm3/yr) and the highest in perimenopause (3.98 mg/cm3/yr). Annual calcium loss in postmenopause was 2.22 mg/cm3.     

Relation of bone mineral density and content to mineral content and density of the fat-free mass.

Differences in the mineral fraction of the fat-free mass (M(FFM)) and in the density of the FFM (D(FFM)) are often inferred from measures of bone mineral content (BMC) or bone mineral density (BMD). We studied the relation of BMC and BMD to the M(FFM) and D(FFM) in a heterogeneous sample of 216 young men (n = 115) and women (n = 101), which included whites (n = 155) and blacks (n = 61) and collegiate athletes ( n = 132) and nonathletes (n = 84). Whole body BMC and BMD were determined by dual-energy X-ray absorptiometry (DXA; Hologic QDR-1000W, enhanced whole body analysis software, version 5.71). FFM was estimated using a four-component model from measures of body density by hydrostatic weighing, body water by deuterium dilution, and bone mineral by DXA. There was no significant relation of BMD to M(FFM) (r = 0.01) or D(FFM) (r = -0.06) or of BMC to M(FFM) (r = -0.11) and a significant, weak negative relation of BMC to D(FFM) (r = -0.14, P = 0.04) in all subjects. Significant low to moderate relationships of BMD or BMC to M(FFM) or D(FFM) were found within some gender-race-athletic status subgroups or when the effects of gender, race, and athletic status were held constant using multiple regression, but BMD and BMC explained only 10-17% of the variance in M(FFM) and 0-2% of the variance in D(FFM) in addition to that explained by the demographic variables. We conclude that there is not a significant positive relation of BMD and BMC to M(FFM) or D(FFM) in young adults and that BMC and BMD should not be used to infer differences in M(FFM) or D(FFM).     

Study of lead accumulation in bones of Wistar rats by X-ray fluorescence analysis: aging effect

The accumulation of lead in several bones of Wistar rats with time was determined and compared for the different types of bones. Two groups were studied: a control group (n = 20), not exposed to lead and a contaminated group (n = 30), exposed to lead from birth, first indirectly through mother's milk, and then directly through a diet containing lead acetate in drinking water (0.2%). Rats age ranged from 1 to 11 months, with approximately 1 month intervals and each of the collections had 3 contaminated rats and 2 control rats. Iliac, femur, tibia-fibula and skull have been analysed by Energy Dispersive X-ray Fluorescence Technique (EDXRF). Samples of formaldehyde used to preserve the bone tissues were also analysed by Electrothermal Atomic Absorption (ETAAS), showing that there was no significant loss of lead from the tissue to the preservative. The bones mean lead concentration of exposed rats range from 100 to 300 μg g(-1) while control rats never exceeded 10 μg g(-1). Mean bone lead concentrations were compared and the concentrations were higher in iliac, femur and tibia-fibula and after that skull. However, of all the concentrations in the different collections, only those in the skull were statistically significantly different (p < 0.05) from the other types of bones. Analysis of a radar chart also allowed us to say that these differences tend to diminish with age. The Spearman correlation test applied to mean lead concentrations showed strong and very strong positive correlations between all different types of bones. This test also showed that mean lead concentrations in bones are negatively correlated with the age of the animals. This correlation is strong in iliac and femur and very strong in tibia-fibula and skull. It was also shown that the decrease of lead accumulation with age is made by three plateaus of accumulation, which coincide, in all analysed bones, between 2nd-3rd and 9th-10th months.     

The Zagreb Skull Collection—The unique identified collection of human skulls from fetuses to centenarians

Skull anatomy and development have been extensively studied due to their significance in evolutionary biology, forensic anthropology, and clinical medicine. Bone collections are an indispensable resource for conducting such anthropological and anatomical studies. However, worldwide there are only few skull collections containing specimens covering the entire fetal and postnatal period. Herein we describe the Zagreb Skull Collection, an identified collection comprising more than 1100 skulls and skull bone sets from the early fetal period to centenarians. The Zagreb Skull Collection consists of two main parts: the unique Collection of Skull Bones containing 386 sets of separated skull bones from the early fetal period to adulthood and the Collection of Skulls containing 742 skulls (age range 4–101 years). The collection was the core source for numerous anatomical studies on the development, postnatal changes, and anatomical variations of the skull. However, the Zagreb Skull Collection is still an underexploited resource for anthropological, forensic, and anatomical studies with translatability to contemporary clinical practice.     

Estimation of 3D shape, internal density and mechanics of proximal femur by combining bone mineral density images with shape and density templates

Measurement of bone mineral density (BMD) by dual-energy X-ray absorptiometry (DXA) alone is only a moderate predictor of fracture risk. Finite element analysis (FEA) of bone mechanics, based on DXA images, may improve the prediction of fracture risk. We developed a method to estimate the 3D shape and density distribution of the proximal femur, using a 2D BMD image and a femur shape template. Proximal femurs of eighteen human cadavers were imaged using computed tomography and divided into two sets (N = 9 + 9). The template was created from the samples in first set by using 3D generalized Procrustes analysis and thin-plate splines. Subsequently, the template and 2D BMD image were utilized to estimate the shape and internal density distribution of the femurs in the second set. Finally, FEA was conducted based on the original and the estimated bone models to evaluate the effect of geometrical and density distributional errors on the mechanical strength. The volumetric errors induced by the estimation itself were low (<1.4%). In the estimation of bones in the second set, the mean distance difference between the estimated and the original bone surfaces was 0.80 ± 0.19 mm, suggesting feasible estimation of the femoral shape. The mean absolute error in voxel-by-voxel BMD was 120±8 mg cm?3. In FEA, the stiffness of the proximal femur differed by -7±16% between the original and estimated bones. The present method, in comparison with methods used in previous studies, improved the prediction of the geometry, the BMD distribution and the mechanical characteristics of the proximal femur. Potentially, the proposed method could ultimately improve the determination of bone fracture risk.