Vertebral Elements Research Articles

Epithelioid hemangioendothelioma of the spine: an analysis of imaging findings

BackgroundEpithelioid hemangioendothelioma (EHE) is a low-grade malignant vascular neoplasm with the potential to metastasize. Primary EHE of the spine is very rare and an accurate diagnosis is crucial to treatment planning. We aim to investigate the imaging and clinical data of spinal EHE to improve the understanding of the disease.MethodsWe retrospectively analyzed the imaging manifestations and clinical data of 12 cases with pathologically confirmed spinal EHE. The imaging features analyzed included number, locations, size, border, density, signal, majority of the lesions, expansile osteolysis, residual bone trabeculae, sclerotic rim, vertebral compression, enhancement.ResultsPatients included 5 female and 7 male patients (mean age: 43.0 ± 19.6 years; range 15–73 years). Multiple lesions were noted in 1 case and single lesion was noted in 11 cases. The lesions were located in the thoracic, cervical, lumbar, and sacral vertebrae in 7, 3, 1, and 1 cases, respectively. They were centered in the vertebral body and posterior elements in 9 and 3 cases, respectively. Residual bone trabeculae, no sclerotic margin, and surrounding soft-tissue mass were noted in 11 cases, each, and mild expansile osteolysis and vertebral compression were noted in 10 and 6 cases, respectively. MRI was performed for 11 patients, all of whom showed isointensity on T1WI, hyperintensity or slight hyperintensity on T2WI, and hyperintensity on fat-suppressed T2WI. A marked enhancement pattern was noted in 10 cases.ConclusionSpinal EHE tend to develop in the thoracic vertebrae. EHE should be considered when residual bone trabeculae can be seen in the bone destruction area, accompanied by pathological compression fracture, no sclerotic rim, and high signal intensity for a vascular tumor on T2WI.

Mapping the m1A, m5C, m6A and m7G methylation atlas in zebrafish brain under hypoxic conditions by MeRIP-seq

BackgroundThe epigenetic modifications play important regulatory roles in tissue development, maintenance of physiological functions and pathological process. RNA methylations, including newly identified m1A, m5C, m6A and m7G, are important epigenetic modifications. However, how these modifications are distributed in the transcriptome of vertebrate brains and whether their abundance is altered under pathological conditions are still poorly understood. In this study, we chose the model animal of zebrafish to conduct a systematic study to investigate the mRNA methylation atlas in the brain.ResultsBy performing unbiased analyses of the m1A, m5C, m6A and m7G methylation of mRNA, we found that within the whole brain transcriptome, with the increase of the gene expression levels, the overall level of each of these four modifications on the related genes was also progressively increased. Further bioinformatics analysis indicated that the zebrafish brain has an abundance of m1A modifications. In the hypoxia-treated zebrafish brains, the proportion of m1A is decreased, affecting the RNA splicing and zebrafish endogenous retroviruses.ConclusionsOur study presents the first comprehensive atlas of m1A, m5C, m6A and m7G in the epitranscriptome of the zebrafish brain and reveals the distribution of these modifications in mRNA under hypoxic conditions. These data provide an invaluable resource for further research on the involvement of m1A, m5C, m6A and m7G in the regulation of miRNA and repeat elements in vertebrates, and provide new thoughts to study the brain hypoxic injury on the aspect of epitranscriptome.

Breaking constraint of mammalian axial formulae

The vertebral column of individual mammalian species often exhibits remarkable robustness in the number and identity of vertebral elements that form (known as axial formulae). The genetic mechanism(s) underlying this constraint however remain ill-defined. Here, we reveal the interplay of three regulatory pathways (Gdf11, miR-196 and Retinoic acid) is essential in constraining total vertebral number and regional axial identity in the mouse, from cervical through to tail vertebrae. All three pathways have differing control over Hox cluster expression, with heterochronic and quantitative changes found to parallel changes in axial identity. However, our work reveals an additional role for Hox genes in supporting axial elongation within the tail region, providing important support for an emerging view that mammalian Hox function is not limited to imparting positional identity as the mammalian body plan is laid down. More broadly, this work provides a molecular framework to interrogate mechanisms of evolutionary change and congenital anomalies of the vertebral column.

Skeletal development and malformations in the early life stage of diploid and triploid turbot (Scophthalmus maximus)

Understanding the early life stage of fish can improve performance during the grow-out phase of the fish. In the present study, skeletal development and malformations were investigated in diploid and cold shock-induced triploid turbot during the early life stages. Diploid and triploid fish were reared in triplicate tanks starting from the hatching date. Thirty fish from each ploidy group (390 triploid and 390 diploid turbot) were randomly sampled at 5-day intervals. Fish skeletons were co-stained with Alician blue and Alizarin red. Growth metric (length), skeletal development, meristic characters, and malformations were examined from hatching to 60 days post-hatch (dph). There was no difference between ploidy groups in skeletal development. The vertebral elements (vertebral centra, neural arch, and haemal arch) mostly remained cartilaginous until 15 dph. Ossification of vertebral elements started on the arch and spine bases at 15 dph and were completely ossified at 20 dph. Ossification of the fins started at 15 dph at the tips of the pterygiophores and completed at 50 dph. The vertebral column ranged between 29 and 31 vertebrae, including 2–7 cephalic vertebrae, 5–9 pre-haemal vertebrae, 14–16 haemal vertebrae, and 3–5 caudal vertebrae. Between ploidy groups, there was a significant difference in the number of vertebrae. Moreover, a significant difference was also detected among ploidy groups in the number of fin rays except for pectoral fin rays. Among all of the factors, dorsal fin rays, anal fin rays, and their pterygiophores caused the main difference between ploidy groups. A total of twelve different types of malformations were detected. At least one type of malformation was observed on 260 diploid and 260 triploid fish. The most frequently encountered malformation was of the neural arch or spine. The frequency of malformed vertebra, haemal arch, and neural arch of diploid turbot was significantly higher than that of triploid counterparts on the caudal region. Malformations were most frequently observed on the caudal region of the vertebra, haemal arches, and neural arches where statistically significant differences were determined. According to the results of this study, cold shock-induced triploid turbot had no disadvantage in terms of development and remain a feasible alternative for the turbot aquaculture industry.

Radiofrequency Ablation of Spine Metastases: A Clinical and Technical Approach.

Percutaneous radiofrequency ablation (RFA) is an integral component of the multidisciplinary treatment algorithm for both local tumor control and palliation of painful spine metastases. This minimally invasive therapy complements additional treatment strategies, such as pain medications, systemic chemotherapy, surgical resection, and radiotherapy. The location and size of the metastatic lesion dictate preprocedure planning and the technical approach. For example, ablation of lesions along the spinal canal, within the posterior vertebral elements, or with paraspinal soft tissue extension are associated with a higher risk of injury to adjacent spinal nerves. Additional interventions may be indicated in conjunction with RFA. For example, ablation of vertebral body lesions can precipitate new, or exacerbate existing, pathologic vertebral compression fractures that can be prevented with vertebral augmentation. This article reviews the indications, clinical work-up, and technical approach for RFA of spine metastases.

Phenotypic regionalization of the vertebral column in the thorny skate Amblyraja radiata: Stability and variation.

Regionalization of the vertebral column occurred early during vertebrate evolution and has been extensively investigated in mammals. However, less data are available on vertebral regions of crown gnathostomes. This is particularly true for batoids (skates, sawfishes, guitarfishes, and rays) whose vertebral column has long been considered to be composed of the same two regions as in teleost fishes despite the presence of a synarcual. However, the numerous vertebral units in chondrichthyans may display a more complex regionalization pattern than previously assumed and the intraspecific variation of such pattern deserves a thorough investigation. In this study, we use micro-computed tomography (µCT) scans of vertebral columns of a growth series of thorny skates Amblyraja radiata to provide the first fine-scale morphological description of vertebral units in a batoids species. We further investigate axial regionalization using a replicable clustering analysis on presence/absence of vertebral elements to decipher the regionalization of the vertebral column of A. radiata. We identify four vertebral regions in this species. The two anteriormost regions, named synarcual and thoracic, may undergo strong developmental or functional constraints because they display stable patterns of shapes and numbers of vertebral units across all growth stages. The third region, named hemal transitional, is characterized by high inter-individual morphological variation and displays a transition between the monospondylous (one centrum per somite) to diplospondylous (two centra per somite) conditions. The posteriormost region, named caudal, is subdivided into three sub-regions with shapes changing gradually along the anteroposterior axis. These regionalized patterns are discussed in light of ecological habits of skates.

Toxic flare phenomenon in osteoblastoma: A case report with literature review

Osteoblastomas are benign neoplasm of the bone that is characterized by clinical and histological similarity to osteoid osteomas. They are larger (>1.5–2 cm) and tend to affect the axial skeleton. Patients typically present commonly in the second or third decades of life with a male predilection. The flare phenomenon in osteoblastoma is a rare but known entity showing florid multifocal periostitis. Few cases have been reported in the literature. Focally aggressive osteoblastomas also present with flare phenomenon mediated by prostaglandin-induced inflammation. We report a strikingly unusual case of an osteoblastoma of the spine in a 23-year-old male patient who presented in our outpatient department with complaints of low backache, weight loss, intermittent stiffness, and fever for the past year. The patient was HLA-B27 positive, diagnosed as ankylosing spondylitis, and clinical symptoms were attributed to sacroiliitis. However, his fever and weight loss, while on treatment, were unexplained. Roentgenogram, computed tomography, and magnetic resonance imaging of the patient depicted a large bone tumor centered at the junction of the right pedicle and transverse process of L5 vertebra, associated with severe reactive marrow edema, periosteal reaction, periostitis, and sclerosis in the posterior vertebral elements also extending into the L4 vertebra. The lesion was suspected to be osteoblastoma with close imaging differential as osteosarcoma. CT-guided biopsy proved osteoblastoma with acute local toxic flare.

The first dinosaurs from the Early Cretaceous Hami Pterosaur Fauna, China

The Early Cretaceous Hami Pterosaur Fauna in Northwest China preserves a large number of specimens of the sexually dimorphic pteranodontoid pterosaur Hamipterus tianshanensis, including 3D eggs and embryos. During the last decade, several more fossils have been collected in this area, including three somphospondylan sauropod specimens. The first is Silutitan sinensis gen. et sp. nov., which consists of an articulated middle to posterior cervical vertebrae series. The second, Hamititan xinjiangensis gen. et sp. nov., consists of an incomplete articulated caudal sequence that could be assigned to lithostrotian titanosaurs based on the strongly procoelous caudal vertebrae with lateral concave surface, as well as marked ventrolateral ridges. The third specimen consists of four sacral vertebral elements, apparently unfused, with exposed camellate internal bone and regarded as somphospondylan. Cladistic analyses based on different datasets recovered Silutitan sinensis as an euhelopodid closely related to Euhelopus and Hamititan xinjiangensis as a titanosaur. Besides the pterosaur Hamipterus and one theropod tooth, these dinosaurs are the first vertebrates reported in this region, increasing the diversity of the fauna as well as the information on Chinese sauropods, further supporting a widespread diversification of somphospondylans during the Early Cretaceous of Asia.

A non-invasive assessment of essential trace element utilization at different trophic levels in African wildlife

The complex relationships that exist between terrestrial mammals and their habitats make African ecosystems highly interactive environments. Anthropogenic activities including climate change have altered geochemical cycles, which influence nutrient availability and deficiency at local, regional and global scales. As synergistic and antagonistic interactions occur between essential elements at both deficiency and excess concentrations, the differences in feeding strategy between trophically distinct groups of terrestrial vertebrates are likely to influence the degree to which overall nutrient needs are met or may be deficient. The overall aim of this study was to investigate and compare quantitative differences of nine essential elements in terrestrial vertebrates occupying different trophic levels within two protected areas; Tswalu Kalahari Reserve (TKR) and Manyeleti Nature Reserve (MNR) South Africa, using faeces as an analytical matrix. Results from linear mixed effects models highlight that concentrations varied widely between individuals. Overall, measured concentrations above their respective means were evident for B and Mn in herbivores, Fe in omnivores and Cu, Co, Fe, Se and Zn in carnivores. Measured concentrations of Mo and Ni did not differ significantly between trophic groups. Although site-specific differences were evident for specific elements, measured mean concentrations of B, Co, Cu, Fe, Mo, Ni, Se and Zn were significantly higher overall at the MNR study site compared to the TKR site. This is the first study to non-invasively assess essential element concentrations across trophic levels in free ranging African wildlife species within protected areas of the savannah biome. Combined with the assessment of environmental matrices, this approach can be used as an effective diagnostic tool for the assessment of animal welfare and the management of protected areas globally.

A Scoring System for Outpatient Orthopedist to Preliminarily Distinguish Spinal Metastasis from Spinal Tuberculosis: A Retrospective Analysis of 141 Patients.

Objective Spinal tuberculosis (TB) misdiagnosed of spinal metastasis was not rarely reported, especially in outpatients department. This study was aimed to establish an outpatient scoring system to preliminarily distinguish spinal metastasis from spinal TB. Methods We retrospectively reviewed consecutive 141 patients with a pathological diagnosis of spinal metastasis (82 cases) or spinal TB (59 cases) in our hospital from January 2017 to June 2018. The following clinical characteristics which can be obtained by outpatient orthopedist were recorded and analyzed: age, gender, malignant tumor history, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and imaging features including distribution characteristics of vertebral lesions, subligamentous spread, paravertebral or psoas abscess, involved vertebral element, intervertebral disc, and sequestra formation. The prevalence of clinical characteristics in spinal metastasis was evaluated, and the scoring system was established using logistic regression analysis. The performance of the scoring system was also prospectively validated. Results The outpatient scoring system was based on five clinical characteristics confirmed as significant predictors of spinal metastasis, namely, malignant tumor history, subligamentous spread, posterior element lesions, preserved discs, and no sequestra formation. Spinal metastasis showed a significant higher score than spinal TB (8.17 points vs. 1.97 points, t = 18.621, P < 0.001), and the optimal cut-off value for the scoring system was 5 points. The sensitivity and specificity of the scoring system for predicting spinal metastasis were 97.85% and 88.33%, respectively, in the validation set. Conclusion Spinal lesions with the score of 5 to 10 would be considered a diagnosis of spinal metastasis, while the score of 0 to 4 may be spinal TB. Because the scoring system is mainly based on the clinical characteristics that can be obtained by an outpatient orthopedist, it is suitable to be used as a diagnostic tool in the outpatient department.

Examination of magnitudes of integration in the catarrhine vertebral column

The evolution of novel vertebral morphologies observed in humans and other extant hominoids may be related to changes in the magnitudes and/or patterns of covariation among traits. To examine this, we tested magnitudes of integration in the vertebral column of cercopithecoids and hominoids, including humans. Three-dimensional surface scans of 14 vertebral elements from 30 Cercopithecus, 32 Chlorocebus, 39 Macaca, 45 Hylobates, 31 Pan, and 86 Homo specimens were used. A resampling method was used to generate distributions of integration coefficient of variation scores for vertebral elements individually using interlandmark distances. Interspecific comparisons of mean integration coefficient of variation were conducted using Mann–Whitney U tests with Bonferroni adjustment. The results showed that hominoids generally had lower mean integration coefficient of variation than cercopithecoids. In addition, humans showed lower mean integration coefficient of variation than other hominoids in their last thoracic and lumbar vertebrae. Cercopithecoids and Hylobates showed relatively lower mean integration coefficient of variation in cervical vertebrae than in thoracolumbar vertebrae. Pan and Homo showed relatively lower mean integration coefficient of variation in the last thoracic and lumbar vertebrae in the thoracolumbar region, except for the L1 of Pan. The results suggest fewer integration-mediated constraints on the evolution of vertebral morphology in hominoids when compared with cercopithecoids. The weaker magnitudes of integration in lumbar vertebrae in humans when compared with chimpanzees likewise suggest fewer constraints on the evolution of novel lumbar vertebrae morphology in humans.

“Wrap-Around Sign” in Non-Hodgkin Lymphoma of the Spine: A Common yet Overlooked Imaging Feature?

Anecdotal cases of the so-called "wrap-around" appearance in non-Hodgkin lymphoma (NHL) of the spine exist in the medical literature. In this paper, we looked at the prevalence of this imaging feature in our institutional cases. We screened our institutional database for biopsy-proven NHL. Our inclusion criteria were the histologically confirmed diagnosis of NHL involving any vertebra, available magnetic resonance imaging of the affected site, and a positive wrap-around sign. Exclusion criteria included lymphoma cases without the wrap-around sign and/or histology other than NHL. We subdivided the cases into 3 groups: 1) lymphoma wrapped around the vertebral body; 2) the posterior elements alone; or 3) both the vertebral body and posterior elements. Our search identified 147 cases of NHL in which a confirmatory biopsy at the primary tumor site was available. Of those, 23 cases fulfilled the inclusion criteria (16 men and 7 women with average age at diagnosis of 63.3 years), yielding prevalence of 15.6% in our series. Most commonly the lymphoma involved the vertebral body with or without some involvement of the posterior vertebral elements (n= 20, 86.9%), followed by posterior vertebral elements (n= 2, 8.7%). One remaining case (4.4%) had lymphoma involving the anterior vertebral body and posterior elements. Findings of our pilot study indicated that the wrap-around sign in cases of NHL could be helpful diagnostically. This sign may be frequently under-recognized, leading to potential for a diagnostic dilemma on imaging. Larger studies are necessary to obtain more precise information about the prevalence of the wrap-around sign.

The fast and the tendinous? Locomotor modifications of the caudal peduncle in Gila spp. from the American Southwest

In the American Southwest, the fishes within the genus Gila evolved in an environment with seasonal rainstorms that caused stochastic flooding. Some species within this genus, such as bonytail (Gila elegans), possess locomotor morphologies that are similar to those seen in high-performance swimmers such as tuna and lamnid sharks. These shared features include a shallow caudal peduncle, lunate tail, and mechanisms to transmit force from the anterior musculature to the tail fin. We compared the skeletal anatomy of the caudal region of bonytail to roundtail chub (Gila robusta) and humpback chub (Gila cypha) to determine which vertebral elements have been modified to create a shallow peduncle. We also tested the tensile strength of the red (slow oxidative) axial muscle by performing a standard stress test. If the muscle can withstand a large load, this suggests it may play a tendon-like role in transmitting force from the anterior muscle to the hypural plate of the tail. Lastly, we measured the collagen content of the red axial muscle (visualized using serial sections and Masson’s trichrome stain) to determine if increased tensile strength is associated with increased collagen content. We found bonytail caudal peduncles are characterized by acute vertebral spines and have red axial muscle that can resist tearing under tension. Roundtail chub peduncles are characterized by relatively more obtuse angles and the red muscle tears easily under tension. Humpback chub possess an intermediate morphology, with relatively obtuse vertebral spine angles and the red muscle can resist tearing under tension. Bonytail have increased collagen content in posterior red axial muscle compared to the anterior musculature also suggesting a tendon-like role of the posterior red muscle. In combination with previous studies of swimming performance, our findings suggest that the axial musculature of bonytail may play a role in transmitting force directly to the shallow peduncle in a manner similar to that of the great lateral tendon of scombrids.

Finite element assessment of a disc-replacement implant for treating scoliotic deformity

BackgroundBracing and spinal fusion surgery have long been the primary methods for idiopathic scoliosis correction; however, there exist multiple limitations with both techniques. Growth modulation techniques have recently been attempted, but are typically performed across multiple vertebral elements. The aim of this study was to quantify the corrective abilities of a dual-angled, wedge shaped, rigid disc implant designed to correct spinal deformity. MethodsThe 3D spinal geometry of four patients was reconstructed using calibrated radiographs, from which personal finite element models were created. Coronal and sagittal Cobb angles and axial stress distribution were calculated pre- and post- simulation of device implantation at the apical vertebral element. FindingsInsertion of a rigid wedged implant resulted in up to 90.1% coronal correction with kyphotic normalization, and reduced axial stress differential within adjacent vertebrae by up to 83.3%. This correction in axial stress differential was seen to propagate to subjacent vertebrae in both rostral and caudal directions. Insertion of two implants yielded greater correction with respect to all three measures. InterpretationLocal Cobb angle correction, increased kyphotic angle, and a decrease in axial stress differential with adjacent and subjacent vertebral levels demonstrate a potential for deformity correction from within the disc space. The decrease in axial stress differential demonstrates a capacity for growth modulation and reversal of the Heuter-Volkmann principle. Based on qualitative views of spinal shape following device implantation, the wedged implant proved more efficacious in correcting single thoracic curves than double major curves.

Traumatic Spondylolisthesis of the Fourth Lumbar Vertebra Without Neurologic Deficit or Fracture of the Posterior Elements

Acute traumatic spondylolisthesis in the lumbosacral spine is an uncommon injury. Traumatic dislocation of the fourth lumbar vertebra over the fifth lumbar vertebra (L4/L5) is extremely rare since few studies have been reported in the current literature. We report on a 53-year-old man, who had a motor vehicle accident and sustained an injury of the lumbar spine without neurological impairment. The radiographic evaluation disclosed an L4/L5 traumatic spondylolisthesis, classified as Meyerding grade III without any fracture of the posterior vertebral elements. To the best of our knowledge, this is the sixth case of L4 traumatic spondylolisthesis without concomitant fracture of the posterior vertebral elements and the third case without any neurological deficit among them. The patient underwent open reduction and posterior instrumentation. Intraoperatively, the posterior ligamentous complex, the capsules of the facet joints and also the disc were found torn, although facets, neural arch, and pedicles were intact. Following decompression and reduction of the spondylolisthesis without any neurologic complications, we performed pedicle screws and rods fixation from the third to the fifth lumbar vertebra (L3-L5). The patient had an uneventful recovery and returned to his previous activity three months after surgery. The four-year follow-up evaluation showed normal spinal alignment, successful pain-free fusion without neurologic complications. Flexion/distraction injury without simultaneous rotation at the L4/L5 segment during traffic accidents or the fall of a heavy object on the bent back accompanied with posterior ligament weakness is thought to be the probable mechanism for this type of injury. Concomitant neurologic impairment is associated with the majority of L4/L5 spondylolisthesis cases. Posterior decompression, reduction, and posterior instrumentation enhances bony fusion, improves the patient's neurologic status and restores the sagittal alignment.

Mathematical, detailed and parametric modelling for smart spinal orthoses

The paper presents a mathematical model and the design details to manufacture a prototype of a smart orthosis for posture correction while sitting on a chair at your office or at home. The global geometry for developing the mathematical model was obtained by direct measuring a human 3D model, developed by scanning one of the authors’ body and 3D printing it. Based on the mathematical model, the detailed design for the entire product was performed in accordance with the product architecture. The stages of detailed design for the critical systems within the final assembly are also presented in the paper. The posture correction orthosis must be customized for each user, thus, once the design for the critical components has been validated, a parametric design has been generated to facilitate the manufacturing process. The technical solutions are generated and analysed for a vertebral element of the orthosis, representing the critical component of the product. The vertebral element is subject to mechanical stresses, so that a finite element analysis was performed. The geometry of the component and its material were validated by using FEA on the CAD model of the vertebral element. The further work will include research regarding the changes needed for transforming the orthosis into a medical device for spinal column illnesses.

Abaloparatide treatment increases bone formation, bone density and bone strength without increasing bone resorption in a rat model of hindlimb unloading.

Disuse osteoporosis can result from prolonged bed rest, paralysis, casts, braces, fractures and other conditions. Abaloparatide (ABL) is a PTHrP analog that increases bone density and strength by stimulating osteogenesis with limited effects on bone resorption. We examined skeletal responses to abaloparatide in young adult male rats with normal weight-bearing and with hindlimb unloading via a pelvic harness. Rats were allocated to four groups (10-12 per group): normal weight-bearing plus vehicle treatment (CON-VEH), normal weight-bearing plus ABL treatment (CON-ABL), hindlimb-unloading plus vehicle (HLU-VEH), or hindlimb-unloading plus ABL (HLU-ABL). Rats received ABL (25μg/kg/day, s.c.) or vehicle throughout the 28-day unloading period and were then sacrificed, at which time HLU-VEH rats exhibited reduced bone formation and significant deficits in tibial, femoral, and vertebral bone mass compared with CON-VEH. ABL treatment increased serum osteocalcin in CON and HLU animals while having no effect on the osteoclast marker TRACP-5b. Longitudinal peripheral quantitative computed tomography (pQCT) indicated that ABL increased trabecular and cortical bone mass in the tibia. ABL was also associated with improved trabecular and cortical bone mass and architectural parameters at the femur, tibia, and vertebrae by μCT. Tibial histomorphometry indicated increased trabecular and endocortical bone formation with HLU-ABL versus HLU-VEH and with CON-ABL versus CON-VEH, and ABL was also associated with lower trabecular and endocortical osteoclast surfaces. Vertebral finite element analysis indicated higher ultimate load and stiffness for CON-ABL versus CON-VEH and for HLU-ABL versus HLU-VEH. In summary, ABL was associated with improved trabecular and cortical bone density and architecture in normal weight-bearing and hindlimb-unloaded rats, with higher bone formation and no difference in bone resorption. ABL was also associated with improved bone biomechanical parameters. These results provide rationale for investigating the ability of abaloparatide to prevent or treat disuse osteoporosis in humans.

Taphonomy of a skeleton of Arctocephalus australis (Carnivora: Pinnipeda: Otariidae) from the Holocene of Miramar locality (southern Buenos Aires, Argentina)

The taphonomy of a partial skeleton of the fur seal Arctocephalus australis from the mid-Holocene of Miramar (southern Buenos Aires province, Argentina) comprising most of both hindlimbs and some vertebral elements is herein described and discussed. The main axis of the long bones is oriented perpendicular to the coastline, flexed and slightly disarticulated, while the vertebrae are somewhat arched, possibly suggesting rigor mortis. The specimen was probably transported from a nearby coastal area, and possibly died from starvation with subsequent stranding. Short weathering times, fragmentation and possible rotation of the pelvic region are the main factors affecting the remains. The material corresponds to a subadult individual, determined by the pattern of fusion of the epiphysis and size of long bones. This study adds important information on the taphonomy of Holocene marine mammals and paleoenvironmental conditions influencing the preservation of these pelagic pinnipeds along the Atlantic Ocean compared with the populations of the Pacific Ocean.

Degenerative joint disease in the Chalcolithic population of El Mirador cave (Sierra de Atapuerca, Spain): The vertebral column

AbstractDegenerative joint disease (DJD) is one of the most common pathological conditions identified in the archaeological record and remains a health problem in modern populations. This study aimed to evaluate DJD of the vertebral column in a sample from a Chalcolithic collective burial at El Mirador cave (Sierra de Atapuerca, Spain) dated to 4,880–4,390 years cal. BP. Most of the human remains recovered were commingled and are in a good state of preservation. Traditionally, far too little attention has been paid to skeletal remains from secondary contexts. Bearing in mind the limitations inherent to this type of study, in this work, we applied an adapted methodology to examine the degree of vertebral degeneration considering the skeletal changes associated with DJD (i.e., osteophyte formation, porosity, lipping and/or eburnation). All data were evaluated at the 0.05 level using the chi‐squared statistic, and comparisons were made between age groups and between the spine regions. Our results showed a higher prevalence of DJD in the lumbar region, although eburnation was the least observed marker in the sample. Additionally, significant differences were found between age groups, with a greater manifestation of DJD in vertebral elements associated with the adult group. These results are consistent with those of other studies and are based on the hypothesis that DJD is highly correlated with age. Overall, the degree of vertebral degeneration is low, but taken together, these results suggest that some individuals from El Mirador cave may have suffered from DJD. Furthermore, the methodology proposed has demonstrated that valuable information can be obtained from commingled skeletal assemblages.

MULTISPIRAL COMPUTED AND MAGNETIC RESONANCE IMAGING OF THORACOLUMBAR SPINE INJURY IN CHILDREN

Introduction. Spinal injury in pediatric practice is met relatively rare; spinal fractures in children do not exceed 5%, and the incidence rate does not exceed 5:100000. However, spinal injuries have a high rate of fetal outcomes (up to 5-10%), and have significant long-lasting negative effects. Therefore, to timely detect such injuries is extremely important for determining treatment tactics, preventing secondary damage to nerve structures and preventing the formation of spinal deformity. Purpose. To assess and compare CT and MRI potentials for developing a diagnostic algorithm in children with thoracolumbar spine injury. Material and methods. 4355 patients, aged 6 months - 17 years, with thoracolumbal spine injury were included into the study . All patients had radiography of the thoracic or lumbar spine and MRI of three spinal sections. Multispiral computed tomography ( MSCT) was performed with Brilliance 16 and 64 scanners. Information on the thoracolumbal spine picture obtained by scanning the chest and abdomen was assessed using findings of frontal and sagittal and 3D reformatted images. MRI was performed on Achieva 3 T scanner; multi-planar T1-, T2-weighted images of (WI) TSE and STIR images in axial, frontal and sagittal projections with a slice thickness of 2-4 mm were obtained. A special spinal 32 channel coil was used. Results. To compare the effectiveness of CT and MRI techniques in the diagnostics of thoracolumbar spinal injury, a sampling of 95 patients was selected. The number of injuries (total and their distribution by the type of injury) was defined using the sample findings. The total number of detected injuries was: only by MRI = 325; only by CT = 228; MRI + CT = 199. By the results of McNemar test, it has been found out that MRI detects statistically significantly better explosive fractures of the vertebrae, ruptures of the posterior longitudinal ligament (PLL) and yellow ligament (YL), ruptures of third column ligaments, herniated discs, epidural and sublingual hematomas, hematomyelia, complete and partial ruptures of the spinal cord and its edema; CT has superiority in detecting fractures of posterior vertebral elements. Conclusion. Currently, MSCT remains a key imaging technique in the diagnostics of acute spinal injuries in most cases in children and adults. Our findings confirm that MRI - in the absence of standard absolute contraindications - can serve as a worthy alternative for assessing damages of the vertebral bodies, ligaments, intervertebral discs, spinal cord and its roots in the acute stage of injury, yielding only in detecting injuries in vertebra posterior elements. The absence of ionizing radiation is also one of MSCT advantages which makes its use preferable for spinal injury diagnostics in children, both for primary and for control examinations.