223 research outputs found

    Two types of bone necrosis in the middle triassic pistosaurus longaevus bones: The results of integrated studies

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    Avascular necrosis, diagnosed on the basis of either a specific pathological modification of the articular surfaces of bone or its radiologic appearance in vertebral centra, has been recognized in many Mesozoic marine reptiles as well as in present-day marine mammals. Its presence in the zoological and paleontologic record is usually associated with decompression syndrome, a disease that affects secondarily aquatic vertebrates that could dive. Bone necrosis can also be caused by infectious processes, but it differs in appearance from decompression syndrome-associated aseptic necrosis. Herein, we report evidence of septic necrosis in the proximal articular surface of the femur of a marine reptile, Pistosaurus longaevus, from the Middle Triassic of Poland and Germany. This is the oldest recognition of septic necrosis associated with septic arthritis in the fossil record so far, and the mineralogical composition of pathologically altered bone is described herein in detail. The occurrence of septic necrosis is contrasted with decompression syndrome-associated avascular necrosis, also described in Pistosaurus longaevus bone from Middle Triassic of Germany

    Spondarthritis in the Triassic

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    Background: The evidence of several forms of arthritis has been well documented in the fossil record. However, for pre-Cenozoic vertebrates, especially regarding reptiles, this record is rather scarce. In this work we present a case report of spondarthritis found in a vertebral series that belonged to a carnivorous archosaurian reptile from the Lower Triassic (,245 million years old) of the South African Karoo. Methodology/Principal Findings: Neutron tomography confirmed macroscopic data, revealing the ossification of the entire intervertebral disc space (both annulus fibrosus and nucleus pulposus), which supports the diagnosis of spondarthritis. Conclusions/Significance: The presence of spondarthritis in the new specimen represents by far the earliest evidence of any form of arthritis in the fossil record. The present find is nearly 100 million years older than the previous oldest report of this pathology, based on a Late Jurassic dinosaur. Spondarthritis may have indirectly contributed to the death of the anima

    Palaeopathology in a Cretaceous terrestrial lizard from China

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    The lizard genus Yabeinosaurus is a common and relatively well-known member of Chinese Lower Cretaceous Jehol Biota, found in both the Yixian and Jiufotang formations of north-eastern China. Previous research on Yabeinosaurus has revealed information on its morphology, phylogenetic position, colouration, diet, and viviparous reproductive strategy. Herein we describe a new specimen preserving the skull and postcranial skeleton. The skull shows features characteristic of Yabeinosaurus robustus, but reveals the morphology of the vomer for the first time. In the postcranial skeleton, the most significant feature is a malformation of the fibula resulting from a fracture that occurred several months before the animal died, possibly as the result of intraspecies aggression or a predation attempt

    Mycobacterium tuberculosis Complex Lipid Virulence Factors Preserved in the 17,000 Year Old Skeleton of an Extinct Bison, Bison antiquus

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    Tracing the evolution of ancient diseases depends on the availability and accessibility of suitable biomarkers in archaeological specimens. DNA is potentially information-rich but it depends on a favourable environment for preservation. In the case of the major mycobacterial pathogens, Mycobacterium tuberculosis and Mycobacterium leprae, robust lipid biomarkers are established as alternatives or complements to DNA analyses. A DNA report, a decade ago, suggested that a 17,000 year old skeleton of extinct Bison antiquus, from Natural Trap Cave, Wyoming, was the oldest known case of tuberculosis. In the current study, key mycobacterial lipid virulence factor biomarkers were detected in the same two samples from this bison. Fluorescence high-performance liquid chromatography (HPLC) indicated the presence of mycolic acids of the mycobacterial type, but they were degraded and could not be precisely correlated with tuberculosis. However, pristine profiles of C29, C30 and C32 mycocerosates and C27 mycolipenates, typical of the Mycobacterium tuberculosis complex, were recorded by negative ion chemical ionization gas chromatography mass spectrometry of pentafluorobenzyl ester derivatives. These findings were supported by the detection of C34 and C36 phthiocerols, which are usually esterified to the mycocerosates. The existence of Pleistocene tuberculosis in the Americas is confirmed and there are many even older animal bones with well-characterised tuberculous lesions similar to those on the analysed sample. In the absence of any evidence of tuberculosis in human skeletons older than 9,000 years BP, the hypothesis that this disease evolved as a zoonosis, before transfer to humans, is given detailed consideration and discussion

    Possible bite-induced abscess and osteomyelitis in Lufengosaurus (Dinosauria: sauropodomorph) from the Lower Jurassic of the Yimen Basin, China

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    We report an osseous abnormality on a specimen of the sauropod dinosaur Lufengosaurus huenei from the Fengjiahe Formation in Yuxi Basin, China. A gross pathological defect occurs on the right third rib, which was subjected to micro-computed tomographic imaging as an aid in diagnosis. The analysis of pathological characteristics and the shape of the abnormality is incompatible with impact or healed trauma, such as a common rib fracture, and instead suggests focal penetration of the rib, possibly due to a failed predator attack. The identification of characteristics based on gross morphology and internal micro-morphology presented by the specimen, suggests an abscess with osteomyelitis as the most parsimonious explanation. Osteomyelitis is a severe infection originating in the bone marrow, usually resulting from the introduction of pyogenic (pus-producing) bacteria into the bone. Micro-tomographic imaging of the lesion suggests a degree of healing and bone remodelling following post-traumatic wound infection with evidence of sclerotic bone formation at the site of pathological focus, indicating that L. huenei survived the initial trauma. However, as osteomyelitis can express through widespread systemic effects, including a lowering of immune response and overall condition, this disease may have been a contributing factor to the eventual death of the individual

    Ancient mycobacterial lipids: Key reference biomarkers in charting the evolution of tuberculosis

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    Mycobacterium tuberculosis has a cell envelope incorporating a peptidoglycan-linked arabinogalactan esterified by long-chain mycolic acids. A range of "free" lipids are associated with the "bound" mycolic acids, producing an effective envelope outer membrane. The distribution of these lipids is discontinuous among mycobacteria and such lipids have proven potential for biomarker use in tracing the evolution of tuberculosis. A plausible evolutionary scenario involves progression from an environmental organism, such as Mycobacterium kansasii, through intermediate "smooth" tubercle bacilli, labelled "Mycobacterium canettii"; cell envelope lipid composition possibly correlates with such a progression. M. kansasii and "M. canettii" have characteristic lipooligosaccharides, associated with motility and biofilms, and glycosyl phenolphthiocerol dimycocerosates ("phenolic glycolipids"). Both these lipid classes are absent in modern M. tuberculosis sensu stricto, though simplified phenolic glycolipids remain in certain current biotypes. Dimycocerosates of the phthiocerol family are restricted to smaller phthiodiolone diesters in M. kansasii. Diacyl and pentaacyl trehaloses are present in "M. canettii" and M. tuberculosis, accompanied in the latter by related sulfated acyl trehaloses. In comparison with environmental mycobacteria, subtle modifications in mycolic acid structures in "M. canettii" and M. tuberculosis are notable. The probability of essential tuberculosis evolution taking place in Pleistocene megafauna, rather than Homo sapiens, is reemphasised

    Syphilis at the Crossroad of Phylogenetics and Paleopathology

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    The origin of syphilis is still controversial. Different research avenues explore its fascinating history. Here we employed a new integrative approach, where paleopathology and molecular analyses are combined. As an exercise to test the validity of this approach we examined different hypotheses on the origin of syphilis and other human diseases caused by treponemes (treponematoses). Initially, we constructed a worldwide map containing all accessible reports on palaeopathological evidences of treponematoses before Columbus's return to Europe. Then, we selected the oldest ones to calibrate the time of the most recent common ancestor of Treponema pallidum subsp. pallidum, T. pallidum subsp. endemicum and T. pallidum subsp. pertenue in phylogenetic analyses with 21 genetic regions of different T. pallidum strains previously reported. Finally, we estimated the treponemes' evolutionary rate to test three scenarios: A) if treponematoses accompanied human evolution since Homo erectus; B) if venereal syphilis arose very recently from less virulent strains caught in the New World about 500 years ago, and C) if it emerged in the Americas between 16,500 and 5,000 years ago. Two of the resulting evolutionary rates were unlikely and do not explain the existent osseous evidence. Thus, treponematoses, as we know them today, did not emerge with H. erectus, nor did venereal syphilis appear only five centuries ago. However, considering 16,500 years before present (yBP) as the time of the first colonization of the Americas, and approximately 5,000 yBP as the oldest probable evidence of venereal syphilis in the world, we could not entirely reject hypothesis C. We confirm that syphilis seems to have emerged in this time span, since the resulting evolutionary rate is compatible with those observed in other bacteria. In contrast, if the claims of precolumbian venereal syphilis outside the Americas are taken into account, the place of origin remains unsolved. Finally, the endeavor of joining paleopathology and phylogenetics proved to be a fruitful and promising approach for the study of infectious diseases

    Testing Human Sperm Chemotaxis: How to Detect Biased Motion in Population Assays

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    Biased motion of motile cells in a concentration gradient of a chemoattractant is frequently studied on the population level. This approach has been particularly employed in human sperm chemotactic assays, where the fraction of responsive cells is low and detection of biased motion depends on subtle differences. In these assays, statistical measures such as population odds ratios of swimming directions can be employed to infer chemotactic performance. Here, we report on an improved method to assess statistical significance of experimentally determined odds ratios and discuss the strong impact of data correlations that arise from the directional persistence of sperm swimming

    Tuberculosis origin: The Neolithic scenario

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    This paper follows the dramatic changes in scientific research during the last 20 years regarding the relationship between the Mycobacterium tuberculosis complex and its hosts - bovids and/or humans. Once the M. tuberculosis and Mycobacterium bovis genomes were sequenced, it became obvious that the old story of M. bovis evolving into the human pathogen should be reversed, as M. tuberculosis is more ancestral than M. bovis. Nevertheless, the timescale and geographical origin remained an enigma. In the current study human and cattle bone samples were examined for evidence of tuberculosis from the site of Atlit-Yam in the Eastern Mediterranean, dating from 9250 to 8160 (calibrated) years ago. Strict precautions were used to prevent contamination in the DNA analysis, and independent centers used to confirm authenticity of findings. DNA from five M. tuberculosis genetic loci was detected and had characteristics consistent with extant genetic lineages. High performance liquid chromatography was used as an independent method of verification and it directly detected mycolic acid lipid biomarkers, specific for the M. tuberculosis complex. These, together with pathological changes detected in some of the bones, confirm the presence of the disease in the Levantine populations during the Pre-pottery Neolithic C period, more than 8000 years ago
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