RESUMO
BACKGROUND: Phylogenetic diversity and evolutionary distinctiveness are highly valuable components of biodiversity, but they are rarely considered in conservation practices. Focusing on a biodiversity hotspot, the Mediterranean Basin, we aimed to identify those areas where evolutionary history is highly threatened and range-restricted in the region. Using null models, we first compared the spatial distributions of three indices: two measured threatened evolutionary history-Expected PDloss and Heightened Evolutionary distinctiveness and Global Endangerment-and one measured endemic evolutionary history-Biogeographically Evolutionary Distinctiveness. We focused on three vertebrate groups with high proportions of endemic, threatened species: amphibians, squamates and terrestrial mammals. Second, we estimated the spatial overlap of hotspots of threatened and endemic evolutionary history within the network of protected areas under several conservation scenarios. RESULTS: Areas that concentrate evolutionary history of conservation interest greatly differed among taxa and indices, although a large proportion of hotspots were identified in the Maghreb, in the East of the Mediterranean Basin as well as in islands. We found that, in a minimum conservation scenario, there was a significant proportion of hotspots for amphibians and squamates that were protected but not for terrestrial mammals. However, in a strong conservation scenario, only few hotspots overlapped with protected areas and they were significantly less protected than in a model where hotspots were chosen randomly. CONCLUSIONS: Some sites concentrate highly threatened and range-restricted evolutionary history of the Mediterranean basin and their conservation could be much improved. These sites are relevant for conservation studies aimed at designing new conservation actions to preserve evolutionary history and the option values it represents.
Assuntos
Evolução Biológica , Vertebrados/genética , Animais , Biodiversidade , Conservação dos Recursos Naturais , Região do Mediterrâneo , Filogenia , Vertebrados/classificação , Vertebrados/crescimento & desenvolvimentoRESUMO
The advent of second-generation microbubble ultrasound contrast agents and the development of contrast specific ultrasound techniques improved the ability of contrast enhanced ultrasound (CEUS) in detecting and characterizing focal liver lesions, opening new prospects in liver imaging. A Medline search in June 2008 identified 72 published studies that used CEUS in focal liver lesion detection, characterization, and follow-up to monitor tumor ablation procedures and antiangiogenic treatment. The purpose of this paper, based on literature review, is to describe the technical recommendations when using CEUS for liver imaging and to define the different vascular patterns of the most relevant benign and malignant lesions. Diagnostic performance of CEUS and the important clinical indications are also presented and discussed. CEUS is increasingly accepted in clinical use for diagnostic imaging and post-interventional workup liver imaging. It may replace many computed tomography and magnetic resonance imaging examinations in the near future, according to the European Federation of Societies for Ultrasound in Medicine and Biology guidelines.
Assuntos
Meios de Contraste , Neoplasias Hepáticas/diagnóstico por imagem , Fígado/diagnóstico por imagem , Ultrassonografia/métodos , Adulto , Diagnóstico Diferencial , Fígado Gorduroso/diagnóstico por imagem , Feminino , Hiperplasia Nodular Focal do Fígado/diagnóstico por imagem , Humanos , Aumento da Imagem , Neoplasias Hepáticas/secundário , Masculino , Microbolhas , Pessoa de Meia-Idade , Guias de Prática Clínica como Assunto , Sensibilidade e EspecificidadeRESUMO
Aortic root and sinotubular junction dilatation and aneurysm of ascending aorta are considered relative contra-indications to implantation of a stentless valve prosthesis, because the modified aortic geometry leads to aortic incompetence and early failure of the prosthesis. Aortic root reconstruction can be performed according to various techniques. We present a surgical technique in which a tubular graft, replacing an ascending aortic aneurysm, allows sinotubular remodeling and satisfactory implantation of a stentless prosthesis. The native aorta is inserted into the vascular prosthesis at the level of the sinotubular junction which is wrapped in order to prevent commissure spreading. Sizing of the vascular and valve prosthesis is made according to annular diameter. Since October 1999, 6 patients have been operated using this technique with good results.
Assuntos
Aneurisma da Aorta Torácica/cirurgia , Implante de Prótese de Valva Cardíaca/métodos , HumanosRESUMO
OBJECTIVES: The preferences for high-fat foods are believed to be based on their sensory attributes and energy density; however less is known about how such preferences might be weakened, other than in response to deterioration in flavor or textural quality. The aim of the present study was to see whether acceptability of reduced fat/energy foods would wane as the original post-ingestive nutritional benefits are reduced when palatability remains essentially constant. DESIGN: Repeated measures, within-subjects design conducted in two counterbalanced three week trials. SETTING/SUBJECTS: Sixteen normal-weight males (mean age 25.8 +/- 1.2 y) came to our laboratory at the Hôpital Hotel Dieu in Paris to eat an afternoon snack on 13 consecutive days (excluding weekends). INTERVENTION/OUTCOME MEASURES: Intake was recorded following repeated exposure to two flavors of standard (10% fat as a percentage of total solids weight), and low (3%) fat ice cream. One group received standard vanilla or low-fat strawberry ice cream on alternate days for two consecutive weeks; these flavor associations were reversed for a second group. The two flavors were rated as equipalatable at the beginning of the experiment at all energy levels. RESULTS: Subjects consumed the same quantity of ice cream throughout the experimental period, independent of energy density or flavor. Consequently, aggregate (summed) energy intake for subjects consuming low-fat ice cream was significantly lower (by 581 kJ (139 kcal), 15.4 g fat). Food intake records for the 24 h period immediately following the test sessions revealed no compensation for fat or energy. Despite the 28% reduction in energy density for the low-fat version, acceptance for the flavors associated with the reduced-energy versions had not declined by the end of the experimental period. CONCLUSIONS: The findings suggest that acceptance of reduced-fat foods may not be critically dependent on the post-ingestive metabolic effects when the reductions in energy density are small. Further tests with more severe reductions, and perhaps over more prolonged time periods, will be necessary to determine at what level of substitution acceptance might begin to deteriorate.
Assuntos
Dieta com Restrição de Gorduras , Ingestão de Energia , Preferências Alimentares , Sorvetes , Paladar , Adulto , Alimentos , Humanos , Sorvetes/análise , MasculinoRESUMO
Standard 3D reconstruction of bones using stereoradiography is limited by the number of anatomical landmarks visible in more than one projection. The proposed technique enables the 3D reconstruction of additional landmarks that can be identified in only one of the radiographs. The principle of this method is the deformation of an elastic object that respects stereocorresponding and non-stereocorresponding observations available in different projections. This technique is based on the principle that any non-stereocorresponding point belongs to a line joining the X-ray source and the projection of the point in one view. The aim is to determine the 3D position of these points on their line of projection when submitted to geometrical and topological constraints. This technique is used to obtain the 3D geometry of 18 cadaveric upper cervical vertebrae. The reconstructed geometry obtained is compared with direct measurements using a magnetic digitiser. The order of precision determined with the point-to-surface distance between the reconstruction obtained with that technique and reference measurements is about 1 mm, depending on the vertebrae studied. Comparison results indicate that the obtained reconstruction is close to the actual vertebral geometry. This method can therefore be proposed to obtain the 3D geometry of vertebrae.
Assuntos
Processamento de Imagem Assistida por Computador/métodos , Radiografia/métodos , Técnicas Estereotáxicas , Vértebras Cervicais/diagnóstico por imagem , Elasticidade , Humanos , Reprodutibilidade dos TestesRESUMO
PURPOSE OF THE STUDY: There are many anatomic descriptions of the spine, but most concentrate on qualitative information. Quantitative data is however important to achieve a better clinical approach, to adapt implant size and to construct geometric models of spine mechanics. MATERIAL AND METHODS: We examined 32 dry spines (160 lumbar vertebrae) obtained from the Orfila Museum anatomy laboratory at the Saints-Pères School of Medicine in Paris. We drew 178 landmarks on the surface of each vertebra and recorded the 3D spatial coordinates of each point using a Fastrack electromagnetic system operating with +/- 0.2 mm precision. The coordinates of the digitalized points were expressed in a local x-y-z axis field (x=posteroanterior axis, y=right-left axis, z=caudocranial axis). The origin O was half way between the "centers" of the vertebral plates. After calculating 112 linear, angular and surface parameters, results were analyzed with the Statview statistics system. RESULTS: All parameters exhibited gaussian distribution. The transpedicular vertebral depth, corresponding to the maximal penetration of a pedicular screw before touching the anterior wall, was nearly constant: 48 mm (mean). The mean height of the pedicle was approximately 16 mm for L1 to L4 and 21 mm for L5. Pedicle width was 7 mm for L1 and L2 then rapidly widened to reach 10 mm for L5. It was noteworthy that the narrowest pedicle (4 mm) was found in 10% of the L1 vertebrae. There was an exponential rise in the sagittal tilt of the pedicles from L1 to L5, measuring approximately 8 degrees for L1 and rising to 24 degrees for L5. DISCUSSION: Our sample of human spines with unknown clinical characteristics (age, sex) is representative of anatomy laboratory populations, generally composed of subjects over 40 years of age, and is thus adapted for studies of the degenerative spine. Our findings are generally in agreement with data reported in the literature and also provided complementary quantitative data concerning the transpedicular vertebral depth that was found to be a rather constant feature of the lumbar spine. It measured between 40 and 56 mm for 95% of the study population. The dimensions of the pedicle is particularly important: the width must be known to determine the size of pedicle screws; it measured between 7 and 12 mm in 95% of the population. The largest mean cross section of the pedicle was found for L5 (82mm(2)), but measured less than 60 mm(2) in 10% of the vertebrae, suggesting predisposition to spondylolysis.