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1.
P. Martin Sander Nicole Klein Paul C. H. Albers Constanze Bickelmann Herman Winkelhorst 《Pal?ontologische Zeitschrift》2014,88(1):55-71
Two partial postcranial skeletons from the Lower Muschelkalk (early Anisian) of Winterswijk, The Netherlands, are described in detail. The specimens were assigned to basal Pistosauroidea, presumably to cf. Cymatosaurus or a closely related taxon. Cymatosaurus is currently the earliest member of the Pistosauroidea and is only known from skull material. Taxonomical assignment is based on humerus morphology and histology, and on morphological differences from other Sauropterygia (Nothosauria and Pachypleurosauria). 相似文献
2.
A New Basal Sauropod Dinosaur from the Middle Jurassic of Niger and the Early Evolution of Sauropoda
Kristian Remes Francisco Ortega Ignacio Fierro Ulrich Joger Ralf Kosma José Manuel Marín Ferrer for the Project PALDES for the Niger Project SNHM Oumarou Amadou Ide Abdoulaye Maga 《PloS one》2009,4(9)
Background
The early evolution of sauropod dinosaurs is poorly understood because of a highly incomplete fossil record. New discoveries of Early and Middle Jurassic sauropods have a great potential to lead to a better understanding of early sauropod evolution and to reevaluate the patterns of sauropod diversification.Principal Findings
A new sauropod from the Middle Jurassic of Niger, Spinophorosaurus nigerensis n. gen. et sp., is the most complete basal sauropod currently known. The taxon shares many anatomical characters with Middle Jurassic East Asian sauropods, while it is strongly dissimilar to Lower and Middle Jurassic South American and Indian forms. A possible explanation for this pattern is a separation of Laurasian and South Gondwanan Middle Jurassic sauropod faunas by geographic barriers. Integration of phylogenetic analyses and paleogeographic data reveals congruence between early sauropod evolution and hypotheses about Jurassic paleoclimate and phytogeography.Conclusions
Spinophorosaurus demonstrates that many putatively derived characters of Middle Jurassic East Asian sauropods are plesiomorphic for eusauropods, while South Gondwanan eusauropods may represent a specialized line. The anatomy of Spinophorosaurus indicates that key innovations in Jurassic sauropod evolution might have taken place in North Africa, an area close to the equator with summer-wet climate at that time. Jurassic climatic zones and phytogeography possibly controlled early sauropod diversification. 相似文献3.
Wen Zhang Langqing Zeng Yanjie Liu Yao Pan Wei Zhang Changqing Zhang Bingfang Zeng Yunfeng Chen 《PloS one》2014,9(8)
Background
The purpose of this study was to evaluate the biomechanical advantages of medial support screws (MSSs) in the locking proximal humeral plate for treating proximal humerus fractures.Methods
Thirty synthetic left humeri were randomly divided into 3 subgroups to establish two-part surgical neck fracture models of proximal humerus. All fractures were fixed with a locking proximal humerus plate. Group A was fixed with medial cortical support and no MSSs; Group B was fixed with 3 MSSs but without medial cortical support; Group C was fixed with neither medial cortical support nor MSSs. Axial compression, torsional stiffness, shear stiffness, and failure tests were performed.Results
Constructs with medial support from cortical bone showed statistically higher axial and shear stiffness than other subgroups examined (P<0.0001). When the proximal humerus was not supported by medial cortical bone, locking plating with medial support screws exhibited higher axial and torsional stiffness than locking plating without medial support screws (P≤0.0207). Specimens with medial cortical bone failed primarily by fracture of the humeral shaft or humeral head. Specimens without medial cortical bone support failed primarily by significant plate bending at the fracture site followed by humeral head collapse or humeral head fracture.Conclusions
Anatomic reduction with medial cortical support was the stiffest construct after a simulated two-part fracture. Significant biomechanical benefits of MSSs in locking plating of proximal humerus fractures were identified. The reconstruction of the medial column support for proximal humerus fractures helps to enhance mechanical stability of the humeral head and prevent implant failure. 相似文献4.
Patricia Andressa de Almeida Buranello Maria Raquel Isnard Moulin Devandir Antonio Souza Jr Maria Célia Jamur Maria Cristina Roque-Barreira Constance Oliver 《PloS one》2010,5(3)
Background
The D-mannose binding lectin ArtinM is known to recruit neutrophils, to degranulate mast cells and may have potential therapeutic applications. However, the effect of ArtinM on mast cell recruitment has not been investigated.Methodology
Male Wistar rats were injected i.p. with ArtinM or ConA (control). The ability of the lectin to degranulate peritoneal and mesenteric mast cells was examined. Recruitment of mast cells to the peritoneal cavity and mesentery after ArtinM injection was examined with or without depletion of peritoneal mast cells by distilled water.Results
ArtinM degranulated both peritoneal and mesentery mast cells in vitro. Three days after i.p. injection of the lectin there were reduced numbers of mast cells in the peritoneal lavage, while at 7 days post injection of ArtinM, the number of peritoneal mast cells was close to control values. Since immature mast cells are recruited from the bone marrow, the effect of the lectin on bone marrow mast cells was examined. Injection of ArtinM resulted in an increased number of mast cells in the bone marrow. To determine if degranulation of mast cells in the peritoneal cavity was required for the increase in bone marrow mast cells, the peritoneal cavity was depleted of mast cells with ultrapure water. Exposure to ArtinM increased the number of mast cells in the bone marrow of rats depleted of peritoneal mast cells.Conclusions
The ArtinM induced recruitment of mast cells from the bone marrow to the peritoneal cavity may partially explain the therapeutic actions of ArtinM. 相似文献5.
Claire J Greenhill Gareth W Jones Mari A Nowell Zarabeth Newton Ann K Harvey Abdul N Moideen Fraser L Collins Anja C Bloom Rebecca C Coll Avril AB Robertson Matthew A Cooper Marcela Rosas Philip R Taylor Luke A O’Neill Ian R Humphreys Anwen S Williams Simon A Jones 《Arthritis research & therapy》2014,16(4)
Introduction
Activation of the inflammasome has been implicated in the pathology of various autoinflammatory and autoimmune diseases. While the NLRP3 inflammasome has been linked to arthritis progression, little is known about its synovial regulation or contribution to joint histopathology. Regulators of inflammation activation, such as interleukin (IL)-10, may have the potential to limit the inflammasome-driven arthritic disease course and associated structural damage. Hence, we used IL-10-deficient (IL-10KO) mice to assess NLRP3 inflammasome-driven arthritic pathology.Methods
Antigen-induced arthritis (AIA) was established in IL-10KO mice and wild-type controls. Using histological and radiographic approaches together with quantitative real-time PCR of synovial mRNA studies, we explored the regulation of inflammasome components. These were combined with selective blocking agents and ex vivo investigative studies in osteoclast differentiation assays.Results
In AIA, IL-10KO mice display severe disease with increased histological and radiographic joint scores. Here, focal bone erosions were associated with increased tartrate-resistant acid phosphatase (TRAP)-positive cells and a localized expression of IL-1β. When compared to controls, IL-10KO synovium showed increased expression of Il1b, Il33 and NLRP3 inflammasome components. Synovial Nlrp3 and Casp1 expression further correlated with Acp5 (encoding TRAP), while neutralization of IL-10 receptor signaling in control mice caused increased expression of Nlrp3 and Casp1. In ex vivo osteoclast differentiation assays, addition of exogenous IL-10 or selective blockade of the NLRP3 inflammasome inhibited osteoclastogenesis.Conclusions
These data provide a link between IL-10, synovial regulation of the NLRP3 inflammasome and the degree of bone erosions observed in inflammatory arthritis.Electronic supplementary material
The online version of this article (doi:10.1186/s13075-014-0419-y) contains supplementary material, which is available to authorized users. 相似文献6.
Trópia de Abreu R Carvalho Md Carneiro CM Giunchetti RC Teixeira-Carvalho A Martins-Filho OA Coura-Vital W Corrêa-Oliveira R Reis AB 《PloS one》2011,6(5):e18873
Background
The bone marrow is considered to be an important storage of parasites in Leishmania-infected dogs, although little is known about cellular genesis in this organ during canine visceral leishmaniasis (CVL).Methodology/Principal Findings
The aim of the present study was to evaluate changes in erythropoiesis and leucopoiesis in bone marrow aspirates from dogs naturally infected with Leishmania chagasi and presenting different clinical statuses and bone marrow parasite densities. The evolution of CVL from asymptomatic to symptomatic status was accompanied by increasing parasite density in the bone marrow. The impact of bone marrow parasite density on cellularity was similar in dogs at different clinical stages, with animals in the high parasite density group. Erythroid and eosinophilic hypoplasia, proliferation of neutrophilic precursor cells and significant increases in lymphocytes and plasma cell numbers were the major alterations observed. Differential bone marrow cell counts revealed increases in the myeloid:erythroid ratio associated to increased numbers of granulopoietic cells in the different clinical groups compared with non-infected dogs.Conclusions
Analysis of the data obtained indicated that the assessment of bone marrow constitutes an additional and useful tool by which to elaborate a prognosis for CVL. 相似文献7.
Lei Shi Lei Shi Ling Wang Yonghong Duan Wei Lei Zhen Wang Jing Li Xiangli Fan Xiaokang Li Shujun Li Zheng Guo 《PloS one》2013,8(2)
Background
The mismatch of the elastic modulus between implants and bone tissue can lead to stress shielding, bone resorption and poor osseointegration. Compared with normal bone tissue, this problem is much more serious in osteoporosis. The purpose of this study was designed to find out whether the novel Ti-24Nb-4Zr-7.9Sn (TNZS) implant with low elastic modulus and high strength was suitable for biomedical material, especially in osteoporosis.Methodology
In vitro study, the viability and Alkaline phosphatase (ALP) activity of osteoblasts on the TNZS and Ti-6V-4V (TAV) were observed. In vivo study, 30 adult female New Zealand rabbits were selected and divided randomly into two groups: sham-operation (SHAM, n = 6) and ovariectomised in combination with methylprednisolone treatment (OVX+MP, n = 24). Two implants were then placed in the tibia of each OVX + MP group rabbit, one in each side (left: TAV; right: TNZS). The OVX + MP group rabbits were sacrificed at 4 and 12 weeks after the implantation. The osteoporotic bone responses to the TNZS and TAV implants were evaluated by pull-out test, Micro-CT analyses and histological observation.Principal Findings
Compared with the TAV group, the TNZS group showed a significant increase (P<0.05) in cell viability and ALP activity, new bone formation and pull-out force.Conclusions
The novel TNZS implants show good biological performance both in vitro and in vivo, which suggests that the alloys are suitable for biomedical applications, especially in osteoporosis. 相似文献8.
Amanda Finan Nikolai Sopko Feng Dong Ben Turturice Matthew Kiedrowski Marc S. Penn 《PloS one》2013,8(7)
Rationale
Stage specific embryonic antigen 1+ (SSEA1+) cells have been described as the most primitive mesenchymal progenitor cell in the bone marrow. Cardiac injury mobilizes SSEA1+ cells into the peripheral blood but their in vivo function has not been characterized.Objective
We generated animals with chimeric bone marrow to determine the fate and function of bone marrow SSEA1+ cells in response to acute cardiac pressure overload.Methods and Results
Lethally irradiated mice were transplanted with normal bone marrow where the wild-type SSEA1+ cells were replaced with green fluorescent protein (GFP) SSEA1+ cells. Cardiac injury was induced by trans-aortic constriction (TAC). We identified significant GFP+ cell engraftment into the myocardium after TAC. Bone marrow GFP+ SSEA1 derived cells acquired markers of endothelial lineage, but did not express markers of c-kit+ cardiac progenitor cells. The function of bone marrow SSEA1+ cells after TAC was determined by transplanting lethally irradiated mice with bone marrow depleted of SSEA1+ cells (SSEA1-BM). The cardiac function of SSEA1-BM mice declined at a greater rate after TAC compared to their complete bone marrow transplant counterparts and was associated with decreased bone marrow cell engraftment and greater vessel rarefication in the myocardium.Conclusions
These results provide evidence for the recruitment of endogenous bone marrow SSEA1+ cells to the myocardium after TAC. We demonstrate that, in vivo, bone marrow SSEA1+ cells have the differentiation potential to acquire endothelial lineage markers. We also show that bone marrow SSEA1+ deficiency is associated with a reduced compensatory capacity to cardiac pressure overload, suggesting their importance in cardiac homeostasis. These data demonstrate that bone marrow SSEA1+ cells are critical for sustaining vascular density and cardiac repair to pressure overload. 相似文献9.
Hao Lu Da-Yong Jiang Ryosuke Motani Pei-Gang Ni Zuo-Yu Sun Andrea Tintori Shi-Zhen Xiao Min Zhou Cheng Ji Wan-Lu Fu 《Palaeoworld》2018,27(1):107-116
The late Ladinian (Middle Triassic) Xingyi Fauna from the Zhuganpo Member of the Falang Formation yields abundant and well-preserved marine reptiles. Bed-by-bed excavation at Wusha in Xingyi of Guizhou Province reveals two marine vertebrate assemblages in a fossiliferous horizons that span 5.1 m in total thickness. The lower assemblage is marked by the near-shore sauropterygians, including the pachypleurosaur Keichousaurus, the nothosaurians Nothosaurus and Lariosaurus, with a strong paleobiogeographic affinity to western Tethys. The upper assemblage consists of oceanic ichthyosaurs and pistosaurs, including the large shastasaurid ichthyosaur Guizhouichthyosaurus, the euichthyosaur Qianichthyosaurus, pistosaurs Yunguisaurus and Wangosaurus, and the thalattosaur Xinpusaurus, with a closer paleobiogeographic affinity to North America. The coastal pachypleurosaur and nothosaurid sauropterygians disappeared in the upper assemblage, suggesting that they were replaced by an oceanic marine reptile community that emerged. The reptilian composition of the upper assemblage is similar to that of the Guanling Biota, which is of the Early Carnian (Late Triassic) in age and thus somewhat younger than the Xingyi Fauna. The ecological turnover of marine reptiles from near-shore to the open ocean community corresponds to the paleoenvironmental changes indicated by lithofacies analysis, δ13C and the global sea level changes. 相似文献
10.
Background
Gaudeamus is an enigmatic hystricognathous rodent that was, until recently, known solely from fragmentary material from early Oligocene sites in Egypt, Oman, and Libya. Gaudeamus'' molars are similar to those of the extant cane rat Thryonomys, and multiple authorities have aligned Gaudeamus with Thryonomys to the exclusion of other living and extinct African hystricognaths; recent phylogenetic analyses have, however, also suggested affinities with South American caviomorphs or Old World porcupines (Hystricidae).Methodology/Principal Findings
Here we describe the oldest known remains of Gaudeamus, including largely complete but crushed crania and complete upper and lower dentitions. Unlike younger Gaudeamus species, the primitive species described here have relatively complex occlusal patterns, and retain a number of plesiomorphic features. Unconstrained parsimony analysis nests Gaudeamus and Hystrix within the South American caviomorph radiation, implying what we consider to be an implausible back-dispersal across the Atlantic Ocean to account for Gaudeamus'' presence in the late Eocene of Africa. An analysis that was constrained to recover the biogeographically more plausible hypothesis of caviomorph monophyly does not place Gaudeamus as a stem caviomorph, but rather as a sister taxon of hystricids.Conclusions/Significance
We place Gaudeamus species in a new family, Gaudeamuridae, and consider it likely that the group originated, diversified, and then went extinct over a geologically brief period of time during the latest Eocene and early Oligocene in Afro-Arabia. Gaudeamurids are the only known crown hystricognaths from Afro-Arabia that are likely to be aligned with non-phiomorph members of that clade, and as such provide additional support for an Afro-Arabian origin of advanced stem and basal crown members of Hystricognathi. 相似文献11.
Rationale
Exogenous stem cell delivery is under investigation to prevent and treat cardiac dysfunction. It is less studied as to the extent endogenous bone marrow derived stem cells contribute to cardiac homeostais in response to stress and the affects of aging on this stress response.Objective
To determine the role of bone marrow (BM) derived stem cells on cardiac homeostasis in response to pressure overload (PO) and how this response is altered by aging.Methods and Results
Young (8 weeks) and old (>40 weeks) C57/b6 mice underwent homo- and heterochronic BM transplantation prior to transverse aortic constriction (TAC). We found that older BM is associated with decreased cardiac function following TAC. This decreased function is associated with decrease in BM cell engraftment, increased myocyte apoptosis, decreased myocyte hypertrophy, increased myocardial fibrosis and decreased cardiac function. Additionally, there is a decrease in activation of resident cells within the heart in response to PO in old mice. Interestingly, these effects are not due to alterations in vascular density or inflammation in response to PO or differences in ex vivo stem cell migration between young and old mice.Conclusions
BM derived stem cells are activated in response to cardiac PO, and the recruitment of BM derived cells are involved in cardiac myocyte hypertrophy and maintenance of function in response to PO which is lost with aging. 相似文献12.
Background
Abundant fossils from the Ediacaran and Cambrian showing cnidarian grade grossly suggest that cnidarian diversification occurred earlier than that of other eumetazoans. However, fossils of possible soft-bodied polyps are scanty and modern corals are dated back only to the Middle Triassic, although molecular phylogenetic results support the idea that anthozoans represent the first major branch of the Cnidaria. Because of difficulties in taxonomic assignments owing to imperfect preservation of fossil cnidarian candidates, little is known about forms ancestral to those of living groups.Methods and Findings
We have analyzed the soft-bodied polypoid microfossils Eolympia pediculata gen. et sp. nov. from the lowest Cambrian Kuanchuanpu Formation in southern China by scanning electron microscopy and computer-aided microtomography after isolating fossils from sedimentary rocks by acetic acid maceration. The fossils, about a half mm in body size, are preserved with 18 mesenteries including directives bilaterally arranged, 18 tentacles and a stalk-like pedicle. The pedicle suggests a sexual life cycle, while asexual reproduction by transverse fission also is inferred by circumferential grooves on the body column.Conclusions
The features found in the present fossils fall within the morphological spectrum of modern Hexacorallia excluding Ceriantharia, and thus Eolympia pediculata could be a stem member for this group. The fossils also demonstrate that basic features characterizing modern hexacorallians such as bilateral symmetry and the reproductive system have deep roots in the Early Cambrian. 相似文献13.
Albert B Raquin C Prigent M Nadot S Brisset F Yang M Ressayre A 《Annals of botany》2011,107(8):1421-1426
Background and Aims
The tam (tardy asynchronous meiosis) mutant of Arabidopsis thaliana, which exhibits a modified cytokinesis with a switch from simultaneous to successive cytokinesis, was used to perform a direct test of the implication of cytokinesis in aperture-pattern ontogeny of angiosperm pollen grains. The aperture pattern corresponds to the number and arrangement of apertures (areas of the pollen wall permitting pollen tube germination) on the surface of the pollen grain.Methods
A comparative analysis of meiosis and aperture distribution was performed in two mutant strains of arabidopsis: quartet and quartet-tam.Key Results
While the number of apertures is not affected in the quartet-tam mutant, the arrangement of the three apertures is modified compared with the quartet, resulting in a different aperture pattern.Conclusions
These results directly demonstrate the relationship between the type of sporocytic cytokinesis and pollen aperture-pattern ontogeny. 相似文献14.
Garcia-Gomez A Ocio EM Crusoe E Santamaria C Hernández-Campo P Blanco JF Sanchez-Guijo FM Hernández-Iglesias T Briñón JG Fisac-Herrero RM Lee FY Pandiella A San Miguel JF Garayoa M 《PloS one》2012,7(4):e34914
Background
Bone loss, in malignant or non-malignant diseases, is caused by increased osteoclast resorption and/or reduced osteoblast bone formation, and is commonly associated with skeletal complications. Thus, there is a need to identify new agents capable of influencing bone remodeling. We aimed to further pre-clinically evaluate the effects of dasatinib (BMS-354825), a multitargeted tyrosine kinase inhibitor, on osteoblast and osteoclast differentiation and function.Methods
For studies on osteoblasts, primary human bone marrow mensenchymal stem cells (hMSCs) together with the hMSC-TERT and the MG-63 cell lines were employed. Osteoclasts were generated from peripheral blood mononuclear cells (PBMC) of healthy volunteers. Skeletally-immature CD1 mice were used in the in vivo model.Results
Dasatinib inhibited the platelet derived growth factor receptor-β (PDGFR-β), c-Src and c-Kit phosphorylation in hMSC-TERT and MG-63 cell lines, which was associated with decreased cell proliferation and activation of canonical Wnt signaling. Treatment of MSCs from healthy donors, but also from multiple myeloma patients with low doses of dasatinib (2–5 nM), promoted its osteogenic differentiation and matrix mineralization. The bone anabolic effect of dasatinib was also observed in vivo by targeting endogenous osteoprogenitors, as assessed by elevated serum levels of bone formation markers, and increased trabecular microarchitecture and number of osteoblast-like cells. By in vitro exposure of hemopoietic progenitors to a similar range of dasatinib concentrations (1–2 nM), novel biological sequelae relative to inhibition of osteoclast formation and resorptive function were identified, including F-actin ring disruption, reduced levels of c-Fos and of nuclear factor of activated T cells 1 (NFATc1) in the nucleus, together with lowered cathepsin K, αVβ3 integrin and CCR1 expression.Conclusions
Low dasatinib concentrations show convergent bone anabolic and reduced bone resorption effects, which suggests its potential use for the treatment of bone diseases such as osteoporosis, osteolytic bone metastasis and myeloma bone disease. 相似文献15.
cAMP/PKA regulates osteogenesis, adipogenesis and ratio of RANKL/OPG mRNA expression in mesenchymal stem cells by suppressing leptin 总被引:1,自引:0,他引:1
Background
Mesenchymal stem cells (MSCs) are a pluripotent cell type that can differentiate into adipocytes, osteoblasts and other cells. The reciprocal relationship between adipogenesis and osteogenesis was previously demonstrated; however, the mechanisms remain largely unknown.Methods and Findings
We report that activation of PKA by 3-isobutyl-1 methyl xanthine (IBMX) and forskolin enhances adipogenesis, the gene expression of PPARγ2 and LPL, and downregulates the gene expression of Runx2 and osteopontin, markers of osteogenesis. PKA activation also decreases the ratio of Receptor Activator of the NF-κB Ligand to Osteoprotegerin (RANKL/OPG) gene expression – the key factors of osteoclastogenesis. All these effects are mediated by the cAMP/PKA/CREB pathway by suppressing leptin, and may contribute to PKA stimulators-induced in vivo bone loss in developing zebrafish.Conclusions
Using MSCs, the center of a newly proposed bone metabolic unit, we identified cAMP/PKA signaling, one of the many signaling pathways that regulate bone homeostasis via controlling cyto-differentiation of MSCs and altering RANKL/OPG gene expression. 相似文献16.
Shinji Miwa Akihiko Takeuchi Hiroko Ikeda Toshiharu Shirai Norio Yamamoto Hideji Nishida Katsuhiro Hayashi Yoshikazu Tanzawa Hiroaki Kimura Kentaro Igarashi Hiroyuki Tsuchiya 《PloS one》2013,8(8)
Background
A variety of surgical procedures are now available for tissue reconstruction after osteosarcoma excision, and an important prognostic factor is the evaluation of response to chemotherapy using histology. Although tumor-bearing autografts are useful tools for reconstruction, re-use of the primary tumor may make it difficult to assess the histological response to chemotherapy, since the entire tumor cannot be analyzed. Here, we analyzed the prognostic value of the histological response in the patients who received frozen tumor-bearing autografts for reconstruction.Method
Retrospective analysis of the medical records of 51 patients with high-grade osteosarcoma of the extremities was performed. All patients received reconstruction using frozen tumor-bearing autografts. Tumor necrosis was evaluated in extraskeletal masses and cancellous bone.Results
Five-year overall survival of patients with good and poor response to chemotherapy was 82.9% and 46.4%, respectively (P = 0.044), and 5-year event-free survival was 57.7% and 36.0%, respectively (P = 0.329). Multivariate analysis revealed that a poor histological response to chemotherapy was a significant prognostic factor for overall survival (P = 0.033).Conclusion
Histological response is an important and reliable prognostic factor in patients undergoing reconstruction using frozen tumor-bearing autografts. 相似文献17.
Alexandra Houssaye Johan Lindgren Rodrigo Pellegrini Andrew H. Lee Damien Germain Michael J. Polcyn 《PloS one》2013,8(10)
Background
During their evolution in the Late Cretaceous, mosasauroids attained a worldwide distribution, accompanied by a marked increase in body size and open ocean adaptations. This transition from land-dwellers to highly marine-adapted forms is readily apparent not only at the gross anatomic level but also in their inner bone architecture, which underwent profound modifications.Methodology/Principal Findings
The present contribution describes, both qualitatively and quantitatively, the internal organization (microanatomy) and tissue types and characteristics (histology) of propodial and epipodial bones in one lineage of mosasauroids; i.e., the subfamily Mosasaurinae. By using microanatomical and histological data from limb bones in combination with recently acquired knowledge on the inner structure of ribs and vertebrae, and through comparisons with extant squamates and semi-aquatic to fully marine amniotes, we infer possible implications on mosasaurine evolution, aquatic adaptation, growth rates, and basal metabolic rates. Notably, we observe the occurrence of an unusual type of parallel-fibered bone, with large and randomly shaped osteocyte lacunae (otherwise typical of fibrous bone) and particular microanatomical features in Dallasaurus, which displays, rather than a spongious inner organization, bone mass increase in its humeri and a tubular organization in its femora and ribs.Conclusions/Significance
The dominance of an unusual type of parallel-fibered bone suggests growth rates and, by extension, basal metabolic rates intermediate between that of the extant leatherback turtle, Dermochelys, and those suggested for plesiosaur and ichthyosaur reptiles. Moreover, the microanatomical features of the relatively primitive genus Dallasaurus differ from those of more derived mosasaurines, indicating an intermediate stage of adaptation for a marine existence. The more complete image of the various microanatomical trends observed in mosasaurine skeletal elements supports the evolutionary convergence between this lineage of secondarily aquatically adapted squamates and cetaceans in the ecological transition from a coastal to a pelagic lifestyle. 相似文献18.
Background
Despite the high prevalence and major public health ramifications, obstructive sleep apnea syndrome (OSAS) remains underdiagnosed. In many developed countries, because community pharmacists (CP) are easily accessible, they have been developing additional clinical services that integrate the services of and collaborate with other healthcare providers (general practitioners (GPs), nurses, etc.). Alternative strategies for primary care screening programs for OSAS involving the CP are discussed.Objective
To estimate the quality of life, costs, and cost-effectiveness of three screening strategies among patients who are at risk of having moderate to severe OSAS in primary care.Design
Markov decision model.Data Sources
Published data.Target Population
Hypothetical cohort of 50-year-old male patients with symptoms highly evocative of OSAS.Time Horizon
The 5 years after initial evaluation for OSAS.Perspective
Societal.Interventions
Screening strategy with CP (CP-GP collaboration), screening strategy without CP (GP alone) and no screening.Outcomes measures
Quality of life, survival and costs for each screening strategy.Results of base-case analysis
Under almost all modeled conditions, the involvement of CPs in OSAS screening was cost effective. The maximal incremental cost for “screening strategy with CP” was about 455€ per QALY gained.Results of sensitivity analysis
Our results were robust but primarily sensitive to the treatment costs by continuous positive airway pressure, and the costs of untreated OSAS. The probabilistic sensitivity analysis showed that the “screening strategy with CP” was dominant in 80% of cases. It was more effective and less costly in 47% of cases, and within the cost-effective range (maximum incremental cost effectiveness ratio at €6186.67/QALY) in 33% of cases.Conclusions
CP involvement in OSAS screening is a cost-effective strategy. This proposal is consistent with the trend in Europe and the United States to extend the practices and responsibilities of the pharmacist in primary care. 相似文献19.