Congenital malformations of the vertebral column in ancient amphibians.

Temnospondyls, the largest group of Palaeozoic and Mesozoic amphibians, primitively possess rhachitomous vertebrae with multipartite centra (consisting of one horse-shoe-shaped inter- and paired pleurocentra). In a group of temnospondyls, the stereospondyls, the intercentra became pronounced and disc-like, whereas the pleurocentra were reduced. We report the presence of congenital vertebral malformations (hemi, wedge and block vertebrae) in Permian and Triassic temnospondyls, showing that defects of formation and segmentation in the tetrapod vertebral column represent a fundamental failure of somitogenesis that can be followed throughout tetrapod evolution. This is irrespective of the type of affected vertebra, that is, rhachitomous or stereospondylous, and all components of the vertebra can be involved (intercentrum, pleurocentrum and neural arch), either together or independently on their own. This is the oldest known occurrence of wedge vertebra and congenital block vertebra described in fossil tetrapods. The frequency of vertebral congenital malformations in amphibians appears unchanged from the Holocene.

Adaptations for marine habitat and the effect of Triassic and Jurassic predator pressure on development of decompression syndrome in ichthyosaurs.

Decompression syndrome (caisson disease or the "the bends") resulting in avascular necrosis has been documented in mosasaurs, sauropterygians, ichthyosaurs, and turtles from the Middle Jurassic to Late Cretaceous, but it was unclear that this disease occurred as far back as the Triassic. We have examined a large Triassic sample of ichthyosaurs and compared it with an equally large post-Triassic sample. Avascular necrosis was observed in over 15% of Late Middle Jurassic to Cretaceous ichthyosaurs with the highest occurrence (18%) in the Early Cretaceous, but was rare or absent in geologically older specimens. Triassic reptiles that dive were either physiologically protected, or rapid changes of their position in the water column rare and insignificant enough to prevent being recorded in the skeleton. Emergency surfacing due to a threat from an underwater predator may be the most important cause of avascular necrosis for air-breathing divers, with relative frequency of such events documented in the skeleton. Diving in the Triassic appears to have been a "leisurely" behavior until the evolution of large predators in the Late Jurassic that forced sudden depth alterations contributed to a higher occurrence of bends.

Do ribs actually have a bare area? A new analysis.

Recognition of macroscopic rib pathology requires an in-depth understanding of anatomy, especially of the attachment of muscle tendons and aponeuroses. Distinguishing periosteal reaction from residual aponeurotic tissues and the rugosity associated with muscle attachments, requires knowledge of these structures. The ribs of twenty cadavers were examined to establish the distribution of muscle attachments and aponeuroses, and their variations. A unique observation was that the entire rib surface is covered by tendon attachments and aponeuroses, without evidence of bare areas that are so prominent in other parts of the skeleton. Discrepancies between rugose regions and the extent of tendon attachments were occasionally noted, with the tendons or aponeuroses extending beyond the areas of attachments of the muscle fibers. Variable dessication of aponeurotic tissues can compromise appearance of normal bone, and may be responsible for past overdiagnosis of periosteal reaction.

Comparative frequency of osseous macroscopic pathology and first report of gout in captive and wild-caught ratites.

This systematic survey of museum ratite (Pterocnemia, Rhea, Casuarius, Struthio, Dromias and Apteryx) skeletal collections was performed to reevaluate previous perspectives and assess effect of captivity on macroscopically detectable pathology. Trauma-related pathology (e.g. focal periosteal reaction, malformed vertebrae) was significantly more common in captive birds (chi2 = 13.414, P < 0.0001) with variable timing of the different injuries. Pathology unrelated to trauma was equally represented in captive and wild-caught ratites. The latter included osteophytes of osteoarthritis, osteochondritis dissecans, infectious arthritis, gout (reported for the first time in a ratite) and neoplasia.

Why are some species more commonly afflicted by arthritis than others? A comparative study of spondyloarthropathy in primates and carnivores.

Spondyloarthropathy is a painful arthritic affliction of humans that also occurs in wild mammals. Important questions remain concerning the underlying causes of spondyloarthropathy in mammals, particularly regarding whether it is infectious in origin or driven by genetic predisposition and environmental stressors. Moreover, spondyloarthropathy has negative effects on host fitness, leading to potential conservation concerns if it impacts threatened species. Using a comparative data set on the prevalence of joint disease in 34 primate species and 100 carnivore species, we tested predictions involving the epidemiological correlates of spondyloarthropathy in wild mammals. Analyses revealed that 5.6% of primates and 3.6% of carnivores exhibited signs of spondyloarthropathy, with maximum incidence as high as 22% in great apes and 27% in bears. We tested whether prevalence of spondyloarthropathy increases with population density and group size, greater contact with soil, a slower host life history, increased ranging, dietary factors and body mass. We found general support for an effect of body mass, with larger bodied primates and carnivores exhibiting a higher prevalence of spondyloarthropathy. In addition, more threatened species experienced higher rates of spondyloarthropathy, with this association influenced by body mass and phylogeny. The effect of body mass could reflect that larger animals are exposed to more pathogens through greater consumption of resources, or that joints of larger bodied mammals experience greater biomechanical stresses, resulting in inflammation and activation of local joint infections.

Lack of bone stiffness/strength contribution to osteoarthritis--evidence for primary role of cartilage damage.

OBJECTIVES: This study was performed to assess osseous contributions to osteoarthritis, obviating the analysis challenges presented by confounding factors in humans and rarity of osteoarthritis in free-ranging mammals. METHODS: Frequency of osteoarthritis in 21 bird species was examined and contrasted with measures of afflicted element bone stiffness and strength and compression/tension-resistant characteristics. RESULTS: Osteoarthritis was present in the ankle of 0-16% of bird species analysed, independent of bone laminarity, cortical thickness, circularity, polarization, cross-sectional diameter, length and pneumatization. CONCLUSIONS: No correlation of frequency of osteoarthritis with parameters of bone strength and biomechanical parameters was found, suggesting that bone is only secondarily affected in osteoarthritis and that cartilage is the initial target of the disease.

The often overlooked digital tuft: clues to diagnosis and pathophysiology of neuropathic disease and spondyloarthropathy.

OBJECTIVE: To assess diagnostic implications of abnormalities of the pedal digital tufts and to identify features to facilitate distinguishing of spondyloarthropathy and leprosy. BACKGROUND: Better criteria for distinguishing between these disorders are necessary if their character, natural history, and evolution are to be understood. METHODS: Pedal x rays of 91 consecutive patients with diabetes, 21 alcoholic patients, 100 with spondyloarthropathy, 8 with scleroderma, and 137 with leprosy, and 188 defleshed skeletons of individuals with alcoholism, syphilis, cerebrovascular disease, and paraplegia from the Terry and Hamman-Todd collections were examined for evidence of osseous and articular pathologies. Digital tuft abnormalities were divided into irregularity, divot, flattening, resorption, whittling, and fragmentation. RESULTS: Tuft divots were more common in alcoholics than in diabetic, and were more common in both than in the other groups studied. Tuft flattening was limited to alcoholic and neurosyphilis groups. Tuft whittling was especially prominent among individuals with spondyloarthropathy, contrasted with leprosy and diabetes. Aligned fractures were more common in diabetics than individuals with leprosy. Misaligned fractures were limited to individuals with leprosy and neurosyphilis. Leprosy and spondyloarthropathy were complicated by phalangeal and metatarsal whittling more commonly than other diseases studied. Background pedal abnormalities, derived from individuals with cardiovascular syphilis, cerebrovascular accidents, and paraplegia, was limited to abnormal divots only. CONCLUSIONS: Pedal digital tufts undergo a variety of pathological alterations useful in the recognition of disorders traditionally considered neuropathic in aetiology and in distinguishing differential considerations. Tuft flattening appears specific for alcoholism and neurosyphilis, and misaligned fractures seem specific for neurosyphilis and leprosy, providing differential assistance related to spondyloarthropathy. Conversely, periosteal reaction distinguishes spondyloarthropathy from leprosy.

Comparative antiplatelet activity of COX1 NSAIDS versus aspirin, encompassing regimen simplification and gastroprotection: a call for a controlled study.

This study was conducted to assess the feasibility of COX1 NSAID substitution for aspirin for preventative therapy related to circulating anticoagulants, as manifest by inhibition of platelet aggregation. There was no difference in platelet aggregation inhibition between aspirin, naproxen, ketoprofen or diclofenac and misoprostol (in combination in the form of Arthrotec). As COX1 NSAIDs appear equivalent in platelet inhibition efficacy to aspirin, therapeutic regimens can be simplified in those individuals who require an NSAID for other problems. Further, despite its short serum halflife, Arthrotec appears as effective as an antiplatelet agent. Controlled, double blind studies of efficacy in blocking clinical events (both cardiovascular and gastrointestinal) are recommended.

"Like a virgin": Absence of rheumatoid arthritis and treponematosis, good sanitation and only rare gout in Italy prior to the 15th century.

OBJECTIVES: This study was conducted to test several hypotheses: 1. That rheumatoid arthritis and syphilis were New World diseases, only transmitted to the Old World subsequent to the passages of Christopher Columbus; 2. To indirectly test the hypothesis that lead poisoning was prevalent in Roman Italy by looking for its byproduct, gout; 3. To test the hypothesis of compromised sanitation in ancient Italy, on the basis of spondyloarthropathy frequency; and 4. To assess variation of trauma frequencies in ancient Italy, by examining frequency of focal periosteal reaction. METHODS: Skeletons from sites ranging from the Bronze Age to the Black Plague epidemic of 1485-1486 were macroscopically evaluated for focal periosteal reaction and for the cardinal signs of rheumatoid arthritis, treponemal disease, gout and spondyloarthropathy. RESULTS: Examination of 688 individuals revealed low frequency of focally distributed periosteal reaction (bumps) in sites dated from the 3400-700 years before present, sharply increasing in the 15th century. Diffuse periosteal reaction was present only as isolated occurrences secondary to hypertrophic osteoarthropathy and sabre shin reaction was notably absent. Erosive disease was uncommon and always oligoarticular in distribution. No marginal erosions were present, with the exception of an isolated metatarsal with classic overhanging edge sign of gout. Subchondral erosions, peripheral joint fusion and axial skeletal involvement identified spondyloarthropathy frequencies of 1-3%, independent of the antiquity of the site. CONCLUSIONS: Italy, prior to Columbus was like a virgin. Rheumatoid arthritis and treponemal disease (specifically syphilis) were not present, further supporting the contention that they are New World-derived diseases. Periosteal signs of minor trauma were rare prior to fifteenth century plague times. This suggests a potential role of domestic (as opposed to outside environment activities) in is development. The hypothesis for a role of lead poisoning in the demise of the Roman Empire is falsified by the rarity of gout. The frequency of spondyloarthropathy was significantly below that found in sanitarily challenged populations, suggesting high standards of hygiene in ancient Italy.

Epidemiologic study of tumors in dinosaurs.

Occasional reports in isolated fragments of dinosaur bones have suggested that tumors might represent a population phenomenon. Previous study of humans has demonstrated that vertebral radiology is a powerful diagnostic tool for population screening. The epidemiology of tumors in dinosaurs was here investigated by fluoroscopically screening dinosaur vertebrae for evidence of tumors. Computerized tomography (CT) and cross-sections were obtained where appropriate. Among more than 10,000 specimens x-rayed, tumors were only found in Cretaceous hadrosaurs (duck-billed dinosaurs). These included hemangiomas and metastatic cancer (previously identified in dinosaurs), desmoplastic fibroma, and osteoblastoma. The epidemiology of tumors in dinosaurs seems to reflect a familial pattern. A genetic propensity or environmental mutagens are suspected.

Thermodynamic resolution of periosteal reaction and taphonomic change.

New bone formation (e.g., periosteal reaction) is one component of bone and joint disease diagnosis. Its application in the archeologic record has been compromised by lack of standardization. An objective technique for validating observations seems especially valuable when visual examination of a single data set results in widely disparate perspectives. Such discrepancies as to presence or absence of periosteal reaction are amenable to objective analysis. Bone, as any other form of matter, has a variety of properties. Some are characterized by weight or volume and are referred to as colligative. Some are related to its intrinsic nature, independent of mass. The latter are referred to as non-colligative. Non-colligative properties of matter provide an opportunity to assess structure, independent of quantity. Study of one such property, entropy, revealed that taphonomic changes can confidently be distinguished from bone surface reaction. Contrasted with the homogeneous entropy of normal bone, the loss of surface bone inherent in taphonomy results in reduced entropy. Contrasted with the homogenous patterns of normal bone, specific non-homogenous patterns allow periosteal reaction to be recognized, independent of variety of periosteal reaction or its origin. Thermographic approach allows observational techniques to be independently validated. Such validation allows for greater facility in interobserver archeologic site sample comparisons.