Problems in determination of skeletal lead burden in archaeological samples: an example from the First African Baptist Church population

Human bone lead content has been demonstrated to be related to socioeconomic status, occupation and other social and environmental correlates. Skeletal tissue samples from 135 individuals from an early nineteenth century Philadelphia cemetery (First African Baptist Church) were studied by electrothermal atomic absorption spectrometry and X-ray fluorescence for lead content. High bone lead levels led to investigation of possible diagenetic effects. These were investigated by several different approaches including distribution of lead within bone by X-ray fluorescence, histological preservation, soil lead concentration and acidity as well as location and depth of burial. Bone lead levels were very high in children, exceeding those of the adult population that were buried in the cemetery, and also those of present day adults. The antemortem age-related increase in bone lead, reported in other studies, was not evidenced in this population. Lead was evenly deposited in areas of taphonomic bone destruction. Synchrotron X-ray fluorescence studies revealed no consistent pattern of lead microdistribution within the bone. Our conclusions are that postmortem diagenesis of lead ion has penetrated these archaeological bones to a degree that makes their original bone lead content irretrievable by any known method. Increased bone porosity is most likely responsible for the very high levels of lead found in bones of newborns and children.     

Lead concentrations in cortical and trabecular bones in deceased smelter workers

The aim of the study was to compare bone lead concentrations in cortical and trabecular bones in long-term exposed primary copper and lead smelter workers, and to relate the measured concentrations to the previous lead exposure of the workers. Lead concentrations in seven bones (trabecular: sternum, vertebrae, iliac crest, rib; cortical: femur, left forefinger, and temporal bone) were determined by electrothermal atomic absorption spectrometry in 32 male, long-term exposed copper and lead smelter workers, and compared with levels in 10 male occupationally unexposed reference persons. A time-integrated blood lead index (cumulative blood lead index, CBLI) was calculated for each worker. The lead levels in the seven studied bones were all significantly higher in active and retired lead workers as compared with the reference group (p相似文献   

High-calcium diet modulates effects of long-term prolactin exposure on the cortical bone calcium content in ovariectomized rats

High physiological prolactin induced positive calcium balance by stimulating intestinal calcium absorption, reducing renal calcium excretion, and increasing bone calcium deposition in female rats. Although prolactin-induced increase in trabecular bone calcium deposition was absent after ovariectomy, its effects on cortical bones were still controversial. The present investigation, therefore, aimed to study the effect of in vivo long-term high physiological prolactin induced by either anterior pituitary (AP) transplantation or 2.5 mg/kg prolactin injection on cortical bones in ovariectomized rats. Since the presence of prolactin receptors (PRLR) in different bones of normal adult rats has not been reported, we first determined mRNA expression of both short- and long-form PRLRs at the cortical sites (tibia and femur) and trabecular sites (calvaria and vertebrae) by using the RT-PCR. Our results showed the mRNA expression of both PRLR isoforms with predominant long form at all sites. However, high prolactin levels induced by AP transplantation in normal rats did not have any effect on the femoral bone mineral density or bone mineral content. By using (45)Ca kinetic study, 2.5 mg/kg prolactin did not alter bone formation, bone resorption, calcium deposition, and total calcium content in tibia and femur of adult ovariectomized rats. AP transplantation also had no effect on the cortical total calcium content in adult ovariectomized rats. Because previous work showed that the effects of prolactin were age dependent and could be modulated by high-calcium diet, interactions between prolactin and these two parameters were investigated. The results demonstrated that 2.0% wt/wt high-calcium diet significantly increased the tibial total calcium content in 9-wk-old young AP-grafted ovariectomized rats but decreased the tibial total calcium content in 22-wk-old adult rats. As for the vertebrae, the total calcium contents in both young and adult rats were not changed by high-calcium diet. The present results thus indicated that the adult cortical bones were potentially direct targets of prolactin. Moreover, the effects of high physiological prolactin on cortical bones were age dependent and were observed only under the modulation of high-calcium diet condition.     

Remnant Woven Bone and Calcified Cartilage in Mouse Bone: Differences between Ages/Sex and Effects on Bone Strength

IntroductionMouse models are used frequently to study effects of bone diseases and genetic determinates of bone strength. Murine bones have an intracortical band of woven bone that is not present in human bones. This band is not obvious under brightfield imaging and not typically analyzed. Due to the band’s morphology and location it has been theorized to be remnant bone from early in life. Furthermore, lamellar and woven bone are well known to have differing mechanical strengths. The purpose of this study was to determine (i) if the band is from early life and (ii) if the woven bone or calcified cartilage contained within the band affect whole bone strength.

Woven Bone Origin Studies

In twelve to fourteen week old mice, doxycycline was used to label bone formed prior to 3 weeks old. Doxycycline labeling and woven bone patterns on contralateral femora matched well and encompassed an almost identical cross-sectional area. Also, we highlight for the first time in mice the presence of calcified cartilage exclusively within the band. However, calcified cartilage could not be identified on high resolution cone-beam microCT scans when examined visually or by thresholding methods.

Mechanical Strength Studies

Subsequently, three-point bending was used to analyze the effects of woven bone and calcified cartilage on whole bone mechanics in a cohort of male and female six and 13 week old Balb/C mice. Three-point bending outcomes were correlated with structural and compositional measures using multivariate linear regression. Woven bone composed a higher percent of young bones than older bones. However, calcified cartilage in older bones was twice that of younger bones, which was similar when normalized by area. Area and/or tissue mineral density accounted for >75% of variation for most strength outcomes. Percent calcified cartilage added significant predictive power to maximal force and bending stress. Calcified cartilage and woven bone could have more influence in genetic models where calcified cartilage percent is double our highest value.     

Comparing rates of recrystallisation and the potential for preservation of biomolecules from the distribution of trace elements in fossil bones

Preservation of intact macromolecules and geochemical signals in fossil bones is mainly controlled by the extent of post-mortem interaction between bones and sediment pore waters. Trace elements such as lanthanum are added to bone post-mortem from pore waters, and where uptake occurs via a simple process of diffusion and adsorption, the elemental distribution can be used to assess the relative extent of bone-pore water interaction and rate of recrystallisation. Distribution profiles can be parameterised effectively using simple exponential equations, and the extent of bone–water interaction compared within and between sites. In this study, the distribution of lanthanum within bone was determined by laser ablation ICP–MS in 60 archaeological and fossil bones from Pleistocene and Cretaceous sites. The rates of recrystallisation and potential for preservation of intact biogeochemical signals vary significantly within and between sites. Elemental profiles within fossil bones hold promise as a screening technique to prospect for intact biomolecules and as a taphonomic tool.     

Recognizing hominoid-modified bones: the taphonomy of colobus bones partially digested by free-ranging chimpanzees in the Kibale Forest, Uganda

We present a taphonomic study of bones that have passed though the digestive tracts of free-ranging chimpanzees from the Kibale Forest in Uganda. The bone assemblage can be characterized as having a very low species diversity; low number of identifiable specimens (NISP) per scat; bones extremely broken up (very small size range); skeletal part frequencies similar in some ways to those resulting from carnivore partial digestion; and sometimes articulated specimens. Modifications to the bones include corrosion, tiny tooth scores and pits, cracking, and fraying of bone edges. Together, these characteristics suggest that hominoid bone digestion may be recognizable, despite some similarities with leopard-, canid-, and eagle-modified bone. Chimpanzees are well-documented hunters of medium-sized vertebrates such as monkeys. This is significant in the study of human evolution if, as it seems, the last common ancestor of chimpanzees and humans was chimpanzee-like. It suggests there was a pre-stone-tool-using hunting phase in human evolution, perhaps by australopiths or the last common ancestor. Taphonomically, pre-stone tool meat eating has been very difficult to detect in the fossil record. However, if chimpanzees leave a recognizable taphonomic signature on the bones of their prey, we will be able to look for analogous signatures in fossil bones associated with fossil hominoids and hominids.     

Evaluation of lead concentrations in 18th-century Omaha Indian skeletons using ICP-MS.

The analysis of skeletal remains of Omaha Indians buried between AD 1780 and 1820 indicated that lead was incorporated in cortical bone. The diagenetic or biogenetic origin of the lead was evaluated by examination of lead isotope ratios of the bones and artifacts, and comparison of lead concentrations in burial soils with those of the bones. The isotopic values of the lead artifacts demonstrate that the lead was mined in the Missouri region. Although the isotope ratios in the bones are not identical with that from the lead artifacts, there is a strong relationship between them. This finding indicates that the lead in the bone was at least partly derived from the artifacts. Because lead artifacts rarely accompanied the burials but lead was ubiquitous in the bones, we suggest a biogenetic origin for the lead. There is also the possibility that some of the lead may have been derived from pigments applied to the corpse during mortuary ritual.     

Inhibitor studies indicate that active cathepsin L is probably essential to its own processing in cultured fibroblasts.

Somatostatin (somatotropin release inhibiting factor; SRIF) has widespread functions as a modulator of neural activity as well as of endocrine and exocrine secretion. In the present paper, the binding characteristics of somatostatin receptors have been investigated in rat long bones using the stable analogue, 125I-SDZ 204-090, as a ligand. Binding studies revealed the presence of a single class of high-affinity binding sites for 125I-SDZ 204-090 on cells prepared from neonatal rat long bones with an equilibrium dissociation constant (KD) of 70.1 +/- 8.2 pM (n = 3). An excellent correlation was found between the ability of various somatostatin analogues to inhibit growth hormone in pituitary cells and to displace the binding of 125I-SDZ 204-090 to the bone cell preparation, indicating that the receptors are very similar, if not identical. The localization of the somatostatin-binding sites was examined by autoradiography after labelling in vitro and in vivo. The binding sites were shown by both procedures to be selectively localized to the metaphysis of rat long bones. The labelling experiments in vivo indicate that these receptors can be reached in the living animal by circulating somatostatin analogues. In addition, the analogue SMS 201-995 inhibited the forskolin-stimulated adenylate cyclase activity in bone cell suspensions. These results suggest that somatostatin could be an important regulatory factor in bone metabolism.     

The influence of mass,volume and density on the frequency of recovery of fossil hominid hand and wrist bones

A study of the mass, volume and density of each of the wrist and hand bones of male and female human skeletons was undertaken. It was found that the mass and volume (i.e. size) of the bones are well correlated with the relative frequencies of preservation ofAustralopithecus and earlyHomo wrist and hand bones from fossil hominid sites in Africa. In general, the larger the bone, the greater its preservation frequency. In contrast to findings on bovid bones, the density of hand and wrist bones is not well correlated with the frequency of such bones recovered from these sites. These findings may be explained in terms of the agents of deposition of the bones, the physical nature of the deposit, and the methods of extraction of the fossils from the deposit.     

Central screw use delays implant dislodgement in osteopenic bone but not synthetic surrogates: A comparison of reverse total shoulder models

Adequate glenoid baseplate fixation in reverse total shoulder arthroplasty (rTSA) is important to achieve, but may prove challenging in the context of glenoid bone loss or osteopenia. Current rTSA testing standards rely upon synthetic bone surrogates, but it is unclear if these models accurately recapitulate the mechanics of osteoporotic bone. Additionally, it also unknown if the use of a central screw effectively provides resistance to micromotion in the milieu of poor quality bone. The purpose of this experiment was to create a novel cyclic load test protocol that elicited clinically relevant failures, so that comparisons of relative motion between baseplates and bones could be made with: (1) synthetic bones and poor quality cadaveric bones, and (2) the use or omission of a central screw. rTSA components were implanted into cadaveric and synthetic bones with and without a central screw. To model a range of loads that may be experienced during abduction, increasing cyclic loads were applied to shoulder joints in 30° of humeral abduction. Cycles and loads prior to permanent deformation exceeding 150 µm, 1 mm, and joint failure were determined using measurements from the test frame and from 3-D motion analysis. Synthetic bones demonstrated significantly more resistance to micromotion in comparison to cadaveric bones. Use of the central screw improved resistance to dislodgement, which was only observed in the cadaveric specimens. This study highlights the need for biomechanical testing with cadaveric specimens, especially when assessing osteopenic or osteoporotic populations.     

Testing meat-eating in early hominids: an analysis of butchery marks on defleshed carcases

The diet of early hominids responsible for the bone accumulations at Plio-Pleistocene sites is still a controversial issue. Meateating and bone marrow consumption are often presented either as complementary or as opposing strategies of carcass exploitation. The occurrence of cut marks on fossil bones at early sites is a potential source of information that has not been consistently used as evidence of what products hominids obtained from carcasses. Some authors interpret them as the result of manipulating meat-bearing bones, whereas others believe that they can also be the result of extracting marginal scraps of flesh that have survived carnivores’ initial consumption of carcasses. In this study, a referential framework concerning the latter process is presented and it is concluded, according to the data drawn from the FLK “Zinj” site and the results obtained in the experiment, that hominids processed meat-bearing bones (in which flesh was abundant) and not defleshed carcasses from felid kills. This work constitutes a reference that can also be used for later Pleistocene sites and adds a further dimension to the hunting-versus-scavenging debate.     

Evaluation of the 3D spatial distribution of the Calcium/Phosphorus ratio in bone using computed-tomography dual-energy analysis

PurposeThe Calcium/Phosphorus (Ca/P) ratio was shown to vary between healthy bones and bones with osteoporotic symptoms. The relation of the Ca/P ratio to bone quality remains under investigation. To study this relation and determine if the ratio can be used to predict bone fractures, a non-invasive 3D imaging technique is required. The first aim of this study was to test the effectiveness of a computed-tomography dual-energy analysis (CT-DEA) technique developed to assess the Ca/P ratio in bone apatite (collagen-free bone) in identifying differences between healthy and inflammation-mediated osteoporotic (IMO) bones. The second aim was to extend the above technique for its application to a more complex structure, intact bone, that could potentially lead to clinical use.MethodsFor the first aim, healthy and IMO rabbit cortical bone apatite samples were assessed. For the second aim, some changes were made to the technique, which was applied to healthy and IMO intact bone samples.ResultsStatistically significant differences between healthy and IMO bone apatite were found for the bulk Ca/P ratio, low Ca/P ratio proportion and interconnected low Ca/P ratio proportion. For the intact bone samples, the bulk Ca/P ratio was found to be significantly different between healthy and IMO.ConclusionsResults show that the CT-DEA technique can be used to identify differences in the Ca/P ratio between healthy and osteoporotic, in both bone apatite and intact bone. With quantitative imaging becoming an increasingly important advancement in medical imaging, CT-DEA for bone decomposition could potentially have several applications.     

Evaluation of Dog Bones in the Indirect Assessment of Environmental Contamination with Trace Elements

The aim of this paper was to determine the level of five elements, two essential for life [zinc (Zn) and copper (Cu)] and three distinctly toxic [lead (Pb), cadmium (Cd), and mercury (Hg)], in four types of biological material in bones of the dog Canis lupus familiaris. The experiment was carried out on bones from the hip joints of dogs. The samples of cartilage, compact bone, spongy bone, and cartilage with adjacent compact bone came from 26 domestic dogs from northwestern Poland. Concentrations of Cu, Zn, Pb, and Cd were determined by ICP-AES (atomic absorption spectrophotometry) in inductively coupled argon plasma, using a Perkin-Elmer Optima 2000 DV. Determination of Hg concentration was performed by atomic absorption spectroscopy. In the examined bone material from the dog, the greatest concentrations (median) were observed for Zn and the lowest for Hg (98 mg Zn/kg and 0.0015 mg Hg/kg dw, respectively). In cartilage and spongy bone, metal concentrations could be arranged in the following descending order: Zn > Pb > Cu > Cd > Hg. In compact bone, the order was slightly different: Zn > Pb > Cd > Cu > Hg (from median 70 mg/kg dw to 0.002 mg/kg dw). The comparisons of metal concentrations between the examined bone materials showed distinct differences only in relation to Hg: between concentrations in spongy bone, compact bone, and in cartilage, being greater in cartilage than in compact bone, and lower again in spongy bone.     

Oxygen isotope variability in bones of wild caught and constant temperature reared sub-adult American alligators

(1) The mean delta18O(BP) ( per thousandSMOW) for any given bone sampled from captive alligators maintained at high constant temperature was lower (indicative of higher temperatures of bone deposition) than that of the same bone from wild alligators caught in Northern Florida, but these differences were only greater than two standard deviations from the mean for the thoracic vertebrae and metatarsal bones. (2) Inter-bone variability of delta18O(BP) ( per thousandSMOW) was similar for captive alligators maintained at constant temperatures and the wild alligators, but intra-bone variability was much greater in wild alligators. (3) The order of mean delta18O(BP) ( per thousandSMOW) of bones (from highest to lowest) differed between treatment groups. However, intra-bone variability obscured the significance of those differences. Nevertheless, the thoracic vertebra had the highest mean delta18O(BP) ( per thousandSMOW), indicative of lower temperatures, and the lowest variability of bones in both groups of alligators. Conversely, the tibia was one of the warmest and more variable bones in both groups of alligators. (4) The pattern of delta18O(BP) ( per thousandSMOW) values across sites within long bones were identical between alligator treatment groups for the femur and humerus but differed between groups for the tibia and metatarsus, and differed between different long bones. The predicted intra-bone pattern for long bones of increasing delta18O(BP) ( per thousandSMOW) indicative of lower temperatures in more distal sampling sites was only obtained from the femurs. (5) Paired cortical and cancellous bone samples from the same site from all individuals in both treatment groups were available for proximal humeri and distal femurs. delta18O(BP) ( per thousandSMOW) values from cortical bone were more variable than those from cancellous bone for both bones. (6) Cortical bone had lower delta18O(BP) ( per thousandSMOW) values indicative of warmer temperatures than cancellous bone at sites sampled on the proximal humeri and distal femurs of all three animals from both treatment groups.     

Gone to the Dogs: a Study of Bone Attrition at a Central Australian Campsite

This is a study of bone discard at a contemporary archaeological site. It assesses the accumulation of bones in the face of destruction by scavenging animals. Three per cent by numbers and two per cent by weight of discarded bones survived to be collected in a six month study period. It is suggested that patterns of scattering by scavengers may help in the interpretation of prehistoric sites, and in particular may allow the prediction of attrition of bone by dogs.     

Heaps of fascinating fragments: reconstructing a medieval reindeer population based on bone middens from the Hardangervidda high mountain plateau,Norway

The results of a detailed morphological and pathological study on reindeer bones (Rangifer tarandus) from four medieval hunting stations on Hardangervidda are presented. As intensive marrow collecting left almost no bones intact, traditional sexing methods could only sparsely be applied. Alternative methods had to be explored to successfully assign the fragments to a sex. Employing linear discriminant analysis (LDA) on early‐ and non‐fusing skeletal elements, I have shown that (incomplete) calcanei, metapodia and phalanges I and II can be used successfully to assign a specimen to a sex and should no longer be excluded from osteometric analyses. Differences in the demographic compositions of the taphocoenoses lead to the assumption that hunters in the 11th century AD targeted large reindeer bucks, while at the 13th‐century sites, the complete biocoenose is represented, albeit in a different ratio. There seems to have been a shift in hunting technique: from selective hunting to mass hunting. Size wise, the reindeer from Hardangervidda were smaller than reindeer from contemporary assemblages from the Dovre area (central Norway), a population that is genetically different. Few pathologically affected bones were encountered in the material, but some cases of infections, bone lesions and a progressed osteosarcoma are described.     

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.     

Trace metals and micronutrients in bone tissues of the red fox <Emphasis Type="Italic">Vulpes vulpes</Emphasis> (L., 1758)

In this study we determined the levels of trace elements (zinc, copper, lead, cadmium and mercury) in three layers of bones of the hip joint (cartilage, compact bone and spongy bone) of 30 red foxes (Vulpes vulpes) from north-western Poland. Concentrations of Cu, Zn, Pb and Cd were determined by atomic absorption spectrophotometry (ICP-AES) in inductively coupled argon plasma using a Perkin-Elmer Optima 2000 DV. Determination of Hg concentration was performed by atomic absorption spectroscopy. In cartilage, compact bone and spongy bone samples from the red fox, median concentrations of the metals studied could be arranged in the following descending series: Zn > Cu > Pb > Cd > Hg, the values ranging from 142 to 0.002 mg/kg dw. There was a significant difference in Cu concentrations, among all the materials analyzed, with much more Cu found in spongy bone than in compact bone. Significant differences were also noted in the case of Hg concentrations in cartilage with compact bone and the spongy bone, and between concentrations of this metal in compact bone and spongy bone. In males, the concentration of Hg in spongy bone was greater than in females. Younger foxes had a higher concentration of this metal in cartilage than adults. The strongest synergistic relationships were observed in spongy bone between the Zn and Cu, Zn and Cd, as well as between Cu and Cd. Statistically significant antagonistic relationships were detected between zinc and lead in compact bone. In addition to monitoring studies conducted on the abiotic environment, an urgent need exists for long-term monitoring of concentrations of heavy metals with long-term effects on living organisms. An important addition is provided by biomonitoring studies on domesticated and free-living mammals, including Canidae.     

Fluoride reduces the rate of dissolution of bone

Recently, fluoride has been used in the treatment of osteoporosis in an attempt to rebuild bone lost due to this disease. Fluoride has been shown to have a profound effect on osteoblasts and bone formation. Studies have shown that synthetic fluorapatite is more stable and less soluble than hydroxyapatite. This study was designed to determine the dissolution properties of bones from rats fed a normal diet versus rats fed a high fluoride diet. Intact and deproteinized bones were dissolved in buffered solutions, containing physiological amounts of inorganic Ca and P, at pH 3.4, 4.4 and 5.4 The data demonstrate that fluoridated bones dissolve slower than normal bones, deproteinized bones dissolve faster than intact bones and that the initial rate of dissolution of fluoridated bone is always significantly lower than that of normal bone. This may help to explain the reduced rate of osteoclastic resorption in patients undergoing fluoride therapy.     

生物力学测试中小梁骨试件的保存和制备方法

骨骼在平时发挥的是支撑和运动作用,在受到撞击后保护脏器的同时自身也会断裂、受损,这都是骨与力之间相互作用产生的结果。如果可以知道骨的力学属性,并带入有限元模型计算,就可以个体化地预测其生活中的各种动作是否会导致急慢性创伤、协助判断暴力事件(如交通事故、坠落等)对其骨骼造成的破坏、在术前对骨骼质量给予指导性的评估[1]等。但是人类的骨骼看似简单,却千变万化,想要确切了解其各项属性的内在联系很困难。骨骼并不是几种材料的简单堆积,如骨骼整体的强度要大于其所有部位累计的强度[2]就是一个证明。一开始,骨的测试方法遵循普通材料的测试方法,随着研究的深入,对于骨的各个部位、各个类型的属性又有了很多新的探索。寻求最佳的试件保存、制作方法是后期测试获得成功的前提,试件保存的温度、水合状态、取材方向、形状和大小都会引起误差,多因素干扰也使分析结果变得更加困难。也正是因为如此,不同学者测得的数据差异往往比较明显。本研究旨在提炼、归纳一些通用、成熟、合理的方法,为后来的研究者在实验技术方面提供参考,让研究结果更有比较意义。