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1.
In order to determine the incubation temperature of eggs laid by non‐avian dinosaurs, we analysed the oxygen isotope compositions of both eggshell carbonate (δ18Oc) and embryo bone phosphate (δ18Op) from seven oviraptorosaur eggs with preserved in ovo embryo bones. These eggs come from the Upper Cretaceous Nanxiong Formation of Jiangxi Province, China. Oviraptorosaur theropods were selected because of their known brooding behaviour as evidenced by preserved adult specimens fossilized in brooding posture on their clutch. Incubation temperature of these embryos was estimated based on the following considerations: eggshell δ18Oc value reflects the oxygen isotope composition of egg water fluid; embryo bones precipitate from the same egg fluid; and oxygen isotope fractionation between phosphate and water is controlled by the egg temperature. A time‐dependent model predicting the δ18Op evolution of the embryo skeleton during incubation as a function of egg temperature was built, and measured δ18Oc and δ18Op values used as boundary conditions. According to the model outputs, oviraptorosaurs incubated their eggs within a 35–40°C range, similar to extant birds and compatible with the known active brooding behaviour of these theropod dinosaurs. Provided that both eggshell and embryo bones preserved their original oxygen isotope compositions, this method could be extended to investigate some reproductive traits of other extinct groups of oviparous amniotes.  相似文献   

2.
Conclusion Substantial fractions of238Pu and241Am deposits were removed from the bones of growing rats by addition of Zn-DTPA to drinking water. The effect of treatment in various parts of long bones was different, obviously due to differences in the bone growth and remodelling.  相似文献   

3.
Several studies have evaluated the effects of dietary vitamin A (VA) on the incidence of skeletal deformities during early ontogeny of fish, but little is known about its effects on bones depending on their process of ossification (dermal or chondral). We examined the incidence of skeletal deformities along development (30 and 48 dph) by double staining technique, in dermal (haemal and caudal vertebral bodies) and chondral (neural and haemal spines, epural, parahypural and hypurals) bones in Senegal sole post metamorphosed larvae fed with different dietary VA levels (37 000, 44 666, 82 666 and 203 000 UI total VA kg?1 DW) during Artemia feeding phase (6–37 dph, at 18°C). Results obtained in this study showed that dietary VA disrupted the skeletogenesis in Senegalese sole post metamorphosed larvae by increasing the incidence of skeletal deformities in the axial skeleton and caudal fin complex, which were dependent on both bone morphogenesis and ossification processes. Fish fed with the highest dietary VA content showed the highest incidence of skeletal deformities and its value increased along ontogeny. However, when we compared the incidence of deformities in skeletal structures considering their ossification process, most skeletal structures derived from chondral ossification showed a significant higher increase in deformity incidences in fish fed an excess of VA (44 666, 82 666 and 203 000 UI kg?1 DW), however within chondral bones, hypurals deformity incidence only increased in sole larvae fed Artemia highest VA content. In contrast, this dietary dose‐response effect was only noted in dermal bones from fish fed the highest dose of VA (203 000 UI kg?1 DW). In addition, the incidence of deformities in chondral bones increased even when the dietary imbalance of VA was corrected, whereas dermal bones were not affected at later ages. These results indicated that depending on the ossification process from which different skeletal structures are derived, bones might be differentially affected by high dietary VA content. Those directly originated from the connective tissue with a preliminary cartilage stage were more sensitive to dietary VA excess than those formed by intramembranous ossification.  相似文献   

4.
Bone resorption,in vitro, is often measured as the release of prelabelled45Ca from neonatal mouse calvarial bones, or from fetal rat long bones. In this report we describe a technique to measure the breakdown of bone-matrix,in vitro. We also describe a new way to dissect neonatal mouse calvarial bones, in order to obtain large amounts of bone samples.Twelve bone fragments were dissected out from each mouse calvaria and were thereafter cultured in CMRL 1066 culture medium in serum-free conditions in 0.5 cm2 multiwell culture dishes. Matrix degradation after treatment with parathyroid hormone was assessed by measuring the amount of carboxyterminal telopeptide of type I collagen (ICTP) by RIA. The data on matrix degradation was compared to the release of prelabelled45Ca from neonatal mouse calvarial bones. We found that the dose-responses for parathyroid hormone-induced release of prelabelled45Ca and ICTP were identical.In conclusion: RIA-analysis of the ICTP-release is an easy and accurate method to measure degradation of bone-matrix,in vitro. Furthermore, the new dissection technique, described in this report, makes it easy to obtain large amounts of bone samples and thus to perform extensive experiments, e.g. dose-responses for agents that enhance bone resorption.  相似文献   

5.
Summary Difluoromethylidene bisphosphonate (F2MBP) is one of the many bisphosphonates known to inhibit bone resorption in vitro and in vivo. We have developed an analytical method, employing anion exchange and postcolumn indirect fluorescence detection, by which F2MBP can be quantified in bone samples. The objective of this study was to relate the concentration of F2MBP in embryonic bones treated in organ culture to the physiological effects of the compound, such as bone resorption (i.e., the amount of 45Ca released into the medium from prelabeled bones) and viability of the osteoclast population (i.e., the incidence of abnormal osteoclasts). Osteoclasts in bones treated with F2MBP exhibited morphological features of apoptosis, such as nuclear fragmentation. Both the number and percentage of these abnormal cells increased with dose of F2MBP and duration of incubation. The decrease in normal osteoclasts was correlated with the decreased amount of 45Ca released into the medium. Bones treated with F2MBP for only the first 5 min of the 48-h incubation period had similar numbers of abnormal osteoclasts and amounts of 45Ca released, as had bones incubated with F2MBP continuously for 48 h. The uptake of F2MBP into the bone was rapid. Bones treated with F2MBP for 6 h were similar to bones treated with F2MBP for the entire 48-h incubation period, both in F2MBP concentration and the 45Ca release ratios. These relationships between concentrations of F2MBP within bone and osteoclast activity and viability implicate apoptosis in the mechanism by which this bisphosphonate inhibits bone resorption.  相似文献   

6.
Assessment of exposure to fluoride (F?) is increasingly focused on mineralized tissues, mainly bones. Their periodic growth and continuous reconstruction make them a good material for studying long-term F? accumulation. In this study, F?concentrations were determined in the bones of foxes and raccoon dogs from north-western Poland and relationships between bone F? and the age categories of the animals were attempted to be identified. Bone samples were collected from femurs of 32 foxes (15 males and 17 females) and 18 raccoon dogs (10 males and 8 females) from polluted, medium-polluted, and unpolluted by F? areas. Bone F? was determined by potentiometric method, and results were expressed per dry weight (dw); they ranged from 176 to 3,668 mg/kg dw in foxes and from 84 to 1,190 mg/kg dw in raccoon dogs. Foxes from north-western Poland accumulated much more F? in their bones than raccoon dogs. Our study shows that the assessment of hazards created by industrial emitters can be conducted conveniently by the measurements of fluorine content in hard tissues of wild animals. Due to availability of such type of material for studies, it seems that the analysis of fluoride content in bones can be a good tool in the development of ecotoxicology.  相似文献   

7.
The aim of our study was to define the biokinetics of 90Sr after chronic contamination by ingestion using a juvenile and adult murine model. Animals ingested 90Sr by drinking water containing 20 kBq l−1 of 90Sr. For the juvenile model, parents received 90Sr before mating and their offspring were killed between birth and 20 weeks of ingestion. For the adult model, 90Sr ingestion started at 9 weeks of age and they were killed after different ingestion periods up to 20 weeks. The body weight, food and water consumption of the animals were monitored on a weekly basis. Before killing and sampling of organs, animals were put in metabolic cages. 90Sr in organs and excreta was determined by liquid scintillation β counting. Highest 90Sr contents were found in bones and were generally higher in females than in males, and 90Sr retention varied according to the skeletal sites. An accumulation of 90Sr in the bones was observed over time for both models, with a plateau level at adult age for the juvenile model. The highest rate of 90Sr accumulation in bones was observed in early life of offspring, i.e. before the age of 6 weeks. With the exception of the digestive tract, 90Sr was below the detection limit in all other organs sampled. Overall, our results confirm that 90Sr mainly accumulates in bones. Furthermore, our results indicate that there are gender- and age-dependent differences in the distribution of 90Sr after low-dose chronic ingestion in the mouse model. These results provide the basis for future studies on possible non-cancerous effects during chronic, long-term exposure to 90Sr through ingestion in a mouse model, especially on the immune and hematopoietic systems.  相似文献   

8.
We evaluated the potential utility of stable isotope analysis of tissues commonly archived by aquatic biologists. Previous studies with chemically preserved samples have shown contradictory results, which present an obstacle for the use of archived sample materials. We tested the effects of ethanol and formalin preservation on zooplankton and of ethanol on benthic macroinvertebrate δ13C and δ15N values. We found that neither formalin nor ethanol had a significant effect on δ13C and δ15N values of preserved zooplankton. Nor did ethanol significantly affect δ13C or δ15N values of macroinvertebrates. However, ethanol preservation slightly, but significantly decreased C:N ratios of both zooplankton and macroinvertebrates, probably reflecting some extraction of lipids. Overall, the effects of preservatives on δ13C and δ15N values that we observed were minor. We also compared δ13C and δ15N values analysed from roach scales and perch operculum bones with those analysed from muscle tissue. Decalcification of scales and operculum bones only slightly improved our comparison to muscle tissue δ13C and δ15N values. Decalcified scales had slightly higher δ13C and lower δ15N values. Similarly, decalcified operculum bones showed slightly increased δ13C and decreased δ15N values to those for fish muscle. Our results confirm that scales and operculum bones can provide a suitable proxy for fish muscle in isotope studies with minor correction. We conclude that various archived sample materials can indeed be used with confidence for historical reconstructions of freshwater food webs by stable isotope analysis. Handling editor: K. Martens  相似文献   

9.
The Middle Neolithic of the Northwestern Mediterranean area (~4500–3500 BC cal) is characterized by the development of food production techniques as well as by increasing social complexity. These characteristics could have had an impact on human dietary patterns. To evaluate human dietary practices and lifeways of the Middle Neolithic populations from the South of France, stable carbon and nitrogen isotope analysis was carried out on 57 human and 53 faunal bones from seven archaeological sites located in the Languedoc and Garonne regions between 20 and 100 km from the Mediterranean Sea, respectively. Results show regional differences in carbon isotope values. Animal and human bones from the Languedoc region are significantly enriched in 13C relative to the Garonne. Conversely, human and dog bones from the Garonne region are significantly enriched in 15N compared to human and dog bones from the Languedoc region. These results highlight the importance of the local ecosystem in human and animal diet as well as a regional differentiation of palaeodietary behavior, which probably relates to economic and social factors. The comparison of stable isotope data with archaeological and biological evidence does not show any significant intra‐ or interpopulation differences. However, the presence of human outliers suggests that migration probably occurred, perhaps in relation to the trade of animals and/or materials. This study also highlights the importance of investigating local animal stable isotope values for the interpretation of human palaeodiet. Am J Phys Anthropol 2010. © 2009 Wiley‐Liss, Inc.  相似文献   

10.
To establish a rational molecular design for bisphosphonate (BP)-modified proteins for efficient bone targeting, a pharmacokinetic study was performed using a series of alendronate (ALN), a nitrogen-containing BP, modified proteins with various molecular weights and varying degrees of modification. Four proteins with different molecular weight—yeast glutathione reductase (GR; MW: 112,000 Da), bovine serum albumin (BSA; MW: 67,000 Da), recombinant human superoxide dismutase (SOD; MW: 32,000 Da), and chicken egg white lysozyme (LZM; MW: 14,000 Da)—were modified with ALN to obtain ALN-modified proteins. Pharmacokinetic analysis of the tissue distribution of the ALN-modified and unmodified proteins was performed after radiolabeling them with indium-111 (111In) by using a bifunctional chelating agent. Calculation of tissue uptake clearances revealed that the bone uptake clearances of 111In-ALN-modified proteins were proportional to the degree of ALN modification. 111In-GR-ALN and BSA-ALN, the two high-molecular-weight proteins, efficiently accumulated in bones, regardless of the degree of ALN modification. Approximately 36 and 34% of the dose, respectively, was calculated to be delivered to the bones. In contrast, the maximum amounts taken up by bone were 18 and 13% of the dose for 111In-SOD-ALN(32) and LZM-ALN(9), respectively, because of their high renal clearance. 111In-SOD modified with both polyethylene glycol (PEG) and ALN (111In-PEG-SOD-ALN) was efficiently delivered to the bone. Approximately 36% of the dose was estimated to be delivered to the bones. In an experimental bone metastasis mouse model, treatment with PEG-SOD-ALN significantly reduced the number of tumor cells in the bone of the mice. These results indicate that the combination of PEG and ALN modification is a promising approach for efficient bone targeting of proteins with a high total-body clearance.  相似文献   

11.
There are few data reported on radionuclide contamination in Antarctica. The aim of this paper is to report 137Cs, 90Sr and 238,239+240Pu and 40K activity concentrations measured in biological samples collected from King George Island (Southern Shetlands, Antarctica), mostly during 2001–2002. The samples included: bones, eggshells and feathers of penguin Pygoscelis papua, bones and feathers of petrel Daption capense, bones and fur of seal Mirounga leonina, algae Himantothallus grandifolius, Desmarestia anceps and Cystosphaera jacquinotii, fish Notothenia corriceps, sea invertebrates Amphipoda, shells of limpet Nacella concina, lichen Usnea aurantiaco-atra, vascular plants Deschampsia antarctica and Colobanthus quitensis, fungi Omphalina pyxidata, moss Sanionia uncinata and soil. The results show a large variation in some activity concentrations. Samples from the marine environment had lower contamination levels than those from terrestrial ecosystems. The highest activity concentrations for all radionuclides were found in lichen and, to a lesser extent, in mosses, probably because lichens take up atmospheric pollutants and retain them. The only significant correlation (except for that expected between 238Pu and 239+240Pu) was noted for moss and lichen samples between plutonium and 90Sr. A tendency to a slow decrease with time seems to be occurring. Analyses of the activity ratios show varying fractionation between various radionuclides in different organisms. Algae were relatively more highly contaminated with plutonium and radiostrontium, and depleted with radiocesium. Feathers had the lowest plutonium concentrations. Radiostrontium and, to a lesser extent, Pu accumulated in bones. The present low intensity of fallout in Antarctic has a lower 238Pu/239+240Pu activity ratio than that expected for global fallout.  相似文献   

12.
Bone is the living composite biomaterial having unique structural property. Presently, there is a considerable gap in our understanding of bone structure and composition in the native state, particularly with respect to the trabecular bone, which is metabolically more active than cortical bones, and is readily lost in post-menopausal osteoporosis. We used solid-state nuclear magnetic resonance (NMR) to compare trabecular bone structure and composition in the native state between normal, bone loss and bone restoration conditions in rat. Trabecular osteopenia was induced by lactation as well as prolonged estrogen deficiency (bilateral ovariectomy, Ovx). Ovx rats with established osteopenia were administered with PTH (parathyroid hormone, trabecular restoration group), and restoration was allowed to become comparable to sham Ovx (control) group using bone mineral density (BMD) and µCT determinants. We used a technique combining 1H NMR spectroscopy with 31P and 13C to measure various NMR parameters described below. Our results revealed that trabecular bones had diminished total water content, inorganic phosphorus NMR relaxation time (T1) and space between the collagen and inorganic phosphorus in the osteopenic groups compared to control, and these changes were significantly reversed in the bone restoration group. Remarkably, bound water was decreased in both osteopenic and bone restoration groups compared to control. Total water and T1 correlated strongly with trabecular bone density, volume, thickness, connectivity, spacing and resistance to compression. Bound water did not correlate with any of the microarchitectural and compression parameters. We conclude that total water, T1 and atomic space between the crystal and organic surface are altered in the trabecular bones of osteopenic rats, and PTH reverses these parameters. Furthermore, from these data, it appears that total water and T1 could serve as trabecular surrogates of micro-architecture and compression strength.  相似文献   

13.
Over 60 recent analyses of animal bones, plant remains, and building timbers from Assiros in northern Greece form an unique series from the 14th to the 10th century BC. With the exception of Thera, the number of 14C determinations from other Late Bronze Age sites in Greece has been small and their contribution to chronologies minimal. The absolute dates determined for Assiros through Bayesian modelling are both consistent and unexpected, since they are systematically earlier than the conventional chronologies of southern Greece by between 70 and 100 years. They have not been skewed by reference to assumed historical dates used as priors. They support high rather than low Iron Age chronologies from Spain to Israel where the merits of each are fiercely debated but remain unresolved.  相似文献   

14.
Prostaglandin synthesis by fetal rat bones was examined by thin-layer chromatography of culture media after preincubation with labeled arachidonic acid. Cultures in rabbit complement (non-heat inactivated serum) were compared with cultures in heat-inactivated serum or cultures treated with indomethacin. The major complement-dependent products were PGE2, PGF and 6-keto-PGF, the metabolite of prostacyclin (PGI2). Since PGI2 had not been previously identified in bone its ability to stimulate bone resorption was tested. Repeated addition of PGI2 stimulated release of previously incorporated 45Ca from fetal rat long bones in both short-term and long-term cultures at concentrations of 10−5 to 10−9M. Because of the short half life of PGI2 in solution at neutral pH, we tested a sulfur analog, thiaprostacyclin (S-PGI2) which was found to be a stimulator of bone resorption at concentrations of 10−5 to 10−6M. These studies suggest that endogenous PGI2 production may play a role in bone metabolism. Since vessels produce PGI2 it is possible that PGI2 release may be responsible for the frequent association between vascular invasion and resorption of bone or calcified cartilage in physiologic remodeling and pathologic osteolysis.  相似文献   

15.
Summary Rat Virus, a parvovirus of rodents that produces a variety of developmental disturbances of the head and face in neonatal animals, was examined for its ability to replicate in neonatal calvariae in vitro. The bones were isolated and infected with RV within 1 d of birth and cultured for up to 7 d. Virus from the bones and supernatant was titered, and the cellular location of replication determined using in situ hybridization. The virus readily replicated in the isolated bony tissues, reaching titers of nearly 107 plaque-forming units/ml. Using viral and complementary strand-specific probes, replication sites were located in the sutures and calvarial bones, as well as in cartilages thought to be part of the neurocranium. Results suggest that the virus localizes and replicates in cells necessary for the normal growth and development of the skull. Supported by grant no. DE-07715 from National Institutes of Health, Bethesda, MD  相似文献   

16.
The mammalian cranial vault largely consists of five flat bones that are joined together along their edges by soft fibrous tissues called sutures. Premature closure of the cranial sutures, craniosynostosis, can lead to serious clinical pathology unless there is surgical intervention. Research into the genetic basis of the disease has led to the development of various animal models that display this condition, e.g. mutant type Fgfr2C342Y/+ mice which display early fusion of the coronal suture (joining the parietal and frontal bones). However, whether the biomechanical properties of the mutant and wild type bones are affected has not been investigated before. Therefore, nanoindentation was used to compare the elastic modulus of cranial bone and sutures in wild type (WT) and Fgfr2C342Y/+mutant type (MT) mice during their postnatal development. Further, the variations in properties with indentation position and plane were assessed. No difference was observed in the elastic modulus of parietal bone between the WT and MT mice at postnatal (P) day 10 and 20. However, the modulus of frontal bone in the MT group was lower than the WT group at both P10 (1.39±0.30 vs. 5.32±0.68 GPa; p<0.05) and P20 (5.57±0.33 vs. 7.14±0.79 GPa; p<0.05). A wide range of values was measured along the coronal sutures for both the WT and MT samples, with no significant difference between the two groups. Findings of this study suggest that the inherent mechanical properties of the frontal bone in the mutant mice were different to the wild type mice from the same genetic background. These differences may reflect variations in the degree of biomechanical adaptation during skull growth, which could have implications for the surgical management of craniosynostosis patients.  相似文献   

17.
Human CD46 is a receptor for the M protein of group A streptococcus (GAS). The emm1 GAS strain GAS472 was isolated from a patient suffering from streptococcal toxic shock‐like syndrome. Human CD46‐expressing transgenic (Tg) mice developed necrotizing fasciitis associated with osteoclast‐mediated progressive and severe bone destruction in the hind paws 3 days after subcutaneous infection with 5 × 105 colony‐forming units of GAS472. GAS472 infection induced expression of the receptor activator of nuclear factor‐κB ligand (RANKL) while concomitantly reducing osteoprotegerin expression in the hind limb bones of CD46 Tg mice. Micro‐computed tomography analysis of the bones suggested that GAS472 infection induced local bone erosion and systemic bone loss in CD46 Tg mice. Because treatment with monoclonal antibodies (mAbs) against mouse CD4+ and CD8+ T lymphocytes did not inhibit osteoclastogenesis, T lymphocyte‐derived RANKL was not considered a major contributor to massive bone loss during GAS472 infection. However, immunohistochemical analysis of the hind limb bones showed that GAS472 infection stimulated RANKL production in various bone marrow cells, including fibroblast‐like cells. Treatment with a mAb against mouse RANKL significantly inhibited osteoclast formation and bone resorption. These data suggest that increased expression of RANKL in heterogeneous bone marrow cells provoked bone destruction during GAS infection.  相似文献   

18.
Stable isotopes in bones are a powerful tool for diet, provenance, climate, and physiological reconstructions, but necessarily require well‐preserved specimens unaltered by postmortem diagenesis or conservation practices. This study examines the effects of Paraloid B‐72 and Butvar B‐98, two common consolidants used in field and museum conservation, on δ13C, δ15N, and δ18O values from bone collagen and hydroxyapatite. The effects of solvent removal (100% acetone, 100% ethanol, 9:1 acetone:xylenes, 9:1 ethanol:xylenes) and drying methods (ambient air, vacuum, oven drying at 80°C) were also examined to determine if bones treated with these consolidants can successfully be cleaned and used for stable isotope analyses. Results show that introduction of Paraloid B‐72 or Butvar B‐98 in 100% acetone or 100% ethanol, respectively, with subsequent removal by the same solvents and drying at 80°C facilitates the most successful removal of consolidants and solvents. The δ13C values in collagen, δ15N in collagen, δ18O in hydroxyapatite phosphate, and δ13C in hydroxyapatite structural carbonate were unaltered by treatments with Paraloid or Butvar and subsequent solvent removal. The δ18O in hydroxyapatite structural carbonate showed nonsystematic variability when bones were treated with Paraloid and Butvar, which is hypothesized to be a result of hydroxyl exchange when bones are exposed to consolidants in solution. It is therefore recommended that δ18O in hydroxyapatite structural carbonate should not be used in stable isotope studies if bones have been treated with Paraloid or Butvar. Am J Phys Anthropol 157:330–338, 2015. © 2015 Wiley Periodicals, Inc.  相似文献   

19.
Double-crystal high-resolution X-ray fluorescence spectroscopy was applied to the chemical state analysis of sulfur and phosphorus in biological samples of leaves and bones. Both S2− and S6+ states are present in all leaves. In plants infected with the mosaic virus, the abundance of S2− state was found to be less than normal. Furthermore, the total sulfur content of leaves with the mosaic virus was less than that in normal leaves. From these results we have concluded that the mosaic virus is related to the decrease in cysteine sulfur (S2−), which is an essential component in amino acids. Most of the phosphorus in leaves and bones was found to be in P5+ state. A small amount of P3+ state, however, was also detected.  相似文献   

20.
During the past few centuries, lead production, consumption and emissions, to our total environment have increased remarkably. We have determined the concentrations of lead in 41 well-preserved ancient and 11 contemporary rib bones of a mature age (40–60 y), with a view to historically evaluating lead exposure in humans. The oldest Japanese bones (1000–300b.c.) were found to contain a mean of 0.58 μg Pb/g dry wt and a mean molar ratio of lead to calcium of 0.6×10−6, compared with 4.7–5.2×10−6 in the bones of the Edo era (1600–1867a.d.) and contemporary residents in Japan. The mean molar ratios of female bones were always higher than those of male bones for each era. From this fact we may assume that facial cosmetics were one of the main routes of lead exposure among the ancient Japanese, especially those who lived during the Edo era.  相似文献   

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