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1.
Proc Natl Acad Sci U S A ; 115(12): 3072-3077, 2018 03 20.
Artigo em Inglês | MEDLINE | ID: mdl-29483242

RESUMO

The extent of increasing anthropogenic impacts on large marine vertebrates partly depends on the animals' movement patterns. Effective conservation requires identification of the key drivers of movement including intrinsic properties and extrinsic constraints associated with the dynamic nature of the environments the animals inhabit. However, the relative importance of intrinsic versus extrinsic factors remains elusive. We analyze a global dataset of ∼2.8 million locations from >2,600 tracked individuals across 50 marine vertebrates evolutionarily separated by millions of years and using different locomotion modes (fly, swim, walk/paddle). Strikingly, movement patterns show a remarkable convergence, being strongly conserved across species and independent of body length and mass, despite these traits ranging over 10 orders of magnitude among the species studied. This represents a fundamental difference between marine and terrestrial vertebrates not previously identified, likely linked to the reduced costs of locomotion in water. Movement patterns were primarily explained by the interaction between species-specific traits and the habitat(s) they move through, resulting in complex movement patterns when moving close to coasts compared with more predictable patterns when moving in open oceans. This distinct difference may be associated with greater complexity within coastal microhabitats, highlighting a critical role of preferred habitat in shaping marine vertebrate global movements. Efforts to develop understanding of the characteristics of vertebrate movement should consider the habitat(s) through which they move to identify how movement patterns will alter with forecasted severe ocean changes, such as reduced Arctic sea ice cover, sea level rise, and declining oxygen content.


Assuntos
Migração Animal , Bases de Dados Factuais , Oceanos e Mares , Vertebrados , Animais , Ecossistema
2.
Plant Dis ; 100(12): 2465-2474, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30686173

RESUMO

Brown rot is an economically important fungal disease affecting stone and pome fruit orchards, as well as harvested fruit during storage and on the market. Monilinia fructicola, M. laxa, and M. fructigena are the main causal agents of this disease and each have a different regulatory status depending on regional regulations. In this study, a new multiplex tool based on real-time polymerase chain reaction was developed to detect the three pathogenic fungi in a single reaction on fruit, twigs, and flowers of Prunus and Malus spp. Species-specific primer-hydrolysis probe combinations were designed to amplify a region located in a previously described MO368 sequenced characterized amplified region marker, and used in a quadruplex format coupled with the 18S Uni universal primer-probe test in order to check the quality of the DNA template. The assay was designed and optimized with the objective to provide high performance values. Experimental data supported its sensitivity, specificity, reproducibility, and robustness. In addition, a set of quality controls was implemented to minimize the risk of false-positive and false-negative results, thus making this new test fit for use in serial analyses and reliable in the framework of official controls.

3.
J Evol Biol ; 24(3): 607-16, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21159006

RESUMO

The traditional distinction between ecological and evolutionary times is eroding, calling for tighter links between ecology and evolution. An example of such a brigde between the two disciplines is the so-called 'animal model', a methodology initially developed by animal breeders, which has become very popular among ecologists studying contemporary microevolution. Using a Bayesian multi-trait 'animal model', we investigated the quantitative genetics of body size, a fitness-related trait, in Subantarctic fur seals (Arctocephalus tropicalis) breeding on Amsterdam Island, Southern Ocean. Our approach jointly modelled the growth and selection processes at work in this population. Body length is heritable for both sexes, and females are under selection for increased body length in this population. We strongly suspect the peculiar ecological context of impoverished, suitable prey availability exacerbated by density-dependence phenomena to be an important selective agent on females breeding on Amsterdam Island.


Assuntos
Otárias/genética , Seleção Genética , Adaptação Fisiológica/genética , Animais , Regiões Antárticas , Evolução Biológica , Tamanho Corporal , Feminino , Aptidão Genética , Geografia
4.
Proc Natl Acad Sci U S A ; 105(33): 11634-9, 2008 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-18695241

RESUMO

Polar regions are particularly sensitive to climate change, with the potential for significant feedbacks between ocean circulation, sea ice, and the ocean carbon cycle. However, the difficulty in obtaining in situ data means that our ability to detect and interpret change is very limited, especially in the Southern Ocean, where the ocean beneath the sea ice remains almost entirely unobserved and the rate of sea-ice formation is poorly known. Here, we show that southern elephant seals (Mirounga leonina) equipped with oceanographic sensors can measure ocean structure and water mass changes in regions and seasons rarely observed with traditional oceanographic platforms. In particular, seals provided a 30-fold increase in hydrographic profiles from the sea-ice zone, allowing the major fronts to be mapped south of 60 degrees S and sea-ice formation rates to be inferred from changes in upper ocean salinity. Sea-ice production rates peaked in early winter (April-May) during the rapid northward expansion of the pack ice and declined by a factor of 2 to 3 between May and August, in agreement with a three-dimensional coupled ocean-sea-ice model. By measuring the high-latitude ocean during winter, elephant seals fill a "blind spot" in our sampling coverage, enabling the establishment of a truly global ocean-observing system.


Assuntos
Gelo , Focas Verdadeiras , Água do Mar , Animais , Temperatura
5.
Ann Pharm Fr ; 68(6): 359-69, 2010 Nov.
Artigo em Francês | MEDLINE | ID: mdl-21073994

RESUMO

After having been used for decades, heparins (unfractionated heparin [UFH] or low molecular weight heparins [LMWH]) and vitamin K antagonists (VKA), which are only parenterally active or which are responsible for frequent iatrogenicity respectively, have to face the competition of new anticoagulant drugs targeting either factor Xa or factor IIa (thrombin). Rivaroxaban (Xarelto(®)) and Dabigatran Etexilate (Pradaxa(®)) are the two leading components. They are more convenient to use and do not require routine coagulation monitoring. They are already marketed for venous thromboembolism prevention in major orthopaedic surgery. Although manufacturers claim that no biological monitoring is required, these two compounds may interfere in routine coagulation tests such as PT or aPTT, and in esoteric assays such as anti-Xa activity (the results of which are usually expressed in international anti-Xa units either UFH or LMWH unit) for Rivaroxaban or anti-IIa activity for Dabigatran Etexilate. Noteworthy is the fact that, in the case of these new anticoagulant drugs, results should be expressed in active product units (nanogram per millilitre of Rivaroxaban or Dabigatran). The new anticoagulants are associated with a bleeding risk comparable to that of VKA and heparins.


Assuntos
Anticoagulantes/uso terapêutico , Benzimidazóis/uso terapêutico , Morfolinas/uso terapêutico , Piridinas/uso terapêutico , Tiofenos/uso terapêutico , Anticoagulantes/classificação , Anticoagulantes/farmacologia , Benzimidazóis/farmacologia , Testes de Coagulação Sanguínea , Dabigatrana , Inibidores do Fator Xa , Humanos , Morfolinas/farmacologia , Piridinas/farmacologia , Rivaroxabana , Tiofenos/farmacologia , Trombina/antagonistas & inibidores
6.
Biol Lett ; 5(6): 830-2, 2009 Dec 23.
Artigo em Inglês | MEDLINE | ID: mdl-19793740

RESUMO

The movement and dietary history of individuals can be studied using stable isotope records in archival keratinous tissues. Here, we present a chronology of temporally fine-scale data on the trophic niche of otariid seals by measuring the isotopic signature of serially sampled whiskers. Whiskers of male Antarctic fur seals breeding at the Crozet Islands showed synchronous and regular oscillations in both their delta(13)C and delta(15)N values that are likely to represent their annual migrations over the long term (mean 4.8 years). At the population level, male Antarctic fur seals showed substantial variation in both delta(13)C and delta(15)N values, occupying nearly all the 'isotopic space' created by the diversity of potential oceanic habitats (from high Antarctica to the subtropics) and prey (from Antarctic krill to subantarctic and subtropical mesopelagic fishes). At the individual level, whisker isotopic signatures depict a large diversity of foraging strategies. Some seals remained in either subantarctic or Antarctic waters, while the migratory cycle of most animals encompassed a wide latitudinal gradient where they fed on different prey. The isotopic signature of whiskers, therefore, revealed new multi-year foraging strategies of male Antarctic fur seals and is a powerful tool for investigating the ecological niche during cryptic stages of mammals' life.


Assuntos
Migração Animal , Comportamento Alimentar , Otárias , Vibrissas/química , Animais , Isótopos de Carbono/análise , Masculino , Isótopos de Nitrogênio/análise
7.
Rev Pneumol Clin ; 74(5): 351-358, 2018 Oct.
Artigo em Francês | MEDLINE | ID: mdl-30316650

RESUMO

INTRODUCTION: Malignant pleural mesothelioma (MPM) is a rare and highly aggressive disease, whose incidence is increasing. Asbestos is the primary causal agent. STATE OF KNOWLEDGE: Knowledge about MPM has evolved. Thoracoscopy is essential for diagnosis of MPM. It allows performing pleural biopsies, to study the extent of the disease and to relieve dyspnea. The pathological diagnosis is also better codified with immunohistochemistry and with analysis by expert of Mesopath group. Curative surgical treatments are pleurectomy decortication and extended pneumonectomy in combination with chemotherapy and/or radiotherapy. Those heavy treatments improve survival in highly selected patients. For the other patients, supportive measures will be considered to reduce pain and dyspnea. PROSPECT: Radical surgical treatment is only offered in therapeutic trials or multimodal treatment. Its place is not formally established. New therapies associated to surgical treatment are being studied. CONCLUSIONS: Surgical management of MPM has to be operated in specialized teams where the survival benefit and quality of life is discussed case by case.


Assuntos
Neoplasias Pulmonares/cirurgia , Mesotelioma/cirurgia , Neoplasias Pleurais/cirurgia , Procedimentos Cirúrgicos Torácicos/métodos , Quimioterapia Adjuvante , Terapia Combinada , Humanos , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/radioterapia , Mesotelioma/diagnóstico , Mesotelioma/tratamento farmacológico , Mesotelioma/radioterapia , Mesotelioma Maligno , Neoplasias Pleurais/diagnóstico , Neoplasias Pleurais/tratamento farmacológico , Neoplasias Pleurais/radioterapia , Pneumonectomia , Radioterapia Adjuvante , Toracoscopia , Resultado do Tratamento
8.
R Soc Open Sci ; 5(10): 181227, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30473858

RESUMO

Evaluating how populations are connected by migration is important for understanding species resilience because gene flow can facilitate recovery from demographic declines. We therefore investigated the extent to which migration may have contributed to the global recovery of the Antarctic fur seal (Arctocephalus gazella), a circumpolar distributed marine mammal that was brought to the brink of extinction by the sealing industry in the eighteenth and nineteenth centuries. It is widely believed that animals emigrating from South Georgia, where a relict population escaped sealing, contributed to the re-establishment of formerly occupied breeding colonies across the geographical range of the species. To investigate this, we interrogated a genetic polymorphism (S291F) in the melanocortin 1 receptor gene, which is responsible for a cream-coloured phenotype that is relatively abundant at South Georgia and which appears to have recently spread to localities as far afield as Marion Island in the sub-Antarctic Indian Ocean. By sequencing a short region of this gene in 1492 pups from eight breeding colonies, we showed that S291F frequency rapidly declines with increasing geographical distance from South Georgia, consistent with locally restricted gene flow from South Georgia mainly to the South Shetland Islands and Bouvetøya. The S291F allele was not detected farther afield, suggesting that although emigrants from South Georgia may have been locally important, they are unlikely to have played a major role in the recovery of geographically more distant populations.

9.
R Soc Open Sci ; 3(7): 160143, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27493771

RESUMO

Individual specialization is widespread among wild populations. While its fitness consequences are central in predicting the ecological and evolutionary trajectories of populations, they remain poorly understood. Long-term individual foraging specializations occur in male Antarctic (Arctocephalus gazella) and Australian (A. pusillus doriferus) fur seals. Strong selective pressure is expected in these highly dimorphic and polygynous species, raising the question of the fitness payoffs associated with different foraging strategies. We investigated the relationship between individual isotopic niche (a proxy of foraging specialization), body size and condition, and an index of reproductive success (harem size) in territorial males. Individuals varied greatly in their skin and fur isotopic values reflecting a range of foraging strategies within the two populations. However, in both species, isotopic niche was not correlated to body size, condition or mating success (R (2)/ρ < 0.06). Furthermore, no foraging niche was predominant in either species, which would have indicated a substantial long-term fitness benefit of a particular strategy via a higher survival rate. These results suggest that the fitness consequences of a foraging strategy depend not only on the quality of prey and feeding habitat but also on an individual's hunting efficiency and skills.

10.
Sci Rep ; 6: 33211, 2016 09 13.
Artigo em Inglês | MEDLINE | ID: mdl-27620663

RESUMO

Investigating the ontogeny of niche differentiation enables to determine at which life-stages sexual segregation arises, providing insights into the main factors driving resource partitioning. We investigated the ontogeny of foraging ecology in Antarctic fur seals (Arctocephalus gazella), a highly dimorphic species with contrasting breeding strategies between sexes. Sequential δ(13)C and δ(15)N values of whiskers provided a longitudinal proxy of the foraging niche throughout the whole life of seals, from weaning, when size dimorphism is minimal to the age of 5. Females exhibited an early-life ontogenetic shift, from a total segregation during their first year at-sea, to a similar isotopic niche as breeding females as early as age 2. In contrast, males showed a progressive change in isotopic niche throughout their development such that 5-year-old males did not share the same niche as territorial bulls. Interestingly, males and females segregated straight after weaning with males appearing to feed in more southerly habitats than females. This spatial segregation was of similar amplitude as observed in breeding adults and was maintained throughout development. Such early-life niche differentiation is an unusual pattern and indicates size dimorphism and breeding constraints do not directly drive sexual segregation contrary to what has been assumed in otariid seals.


Assuntos
Ecossistema , Comportamento Alimentar/fisiologia , Otárias/fisiologia , Comportamento Sexual Animal/fisiologia , Fatores Etários , Animais , Regiões Antárticas , Isótopos de Carbono/metabolismo , Feminino , Masculino , Isótopos de Nitrogênio/metabolismo , Estações do Ano , Fatores Sexuais , Fatores de Tempo , Vibrissas/metabolismo
11.
Arch Surg ; 125(3): 385-8, 1990 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-2306185

RESUMO

Nineteen patients with middle and lower rectal carcinomas were operated on, with abdominoperineal resection in 10 patients, lower anterior resection with coloanal anastomosis in 6 patients, and colorectal anastomosis in 3 patients. The distance of the lower margin of the tumor to insertion of the levator ani on the rectal wall was correctly evaluated by computed tomography in 12 (63%) of 19 patients and by magnetic resonance imaging in 13 (68%) of 19 patients, while digital examination correctly assessed the distance in 15 (79%) of 19 patients. Computed tomography and magnetic resonance imaging were unable to assess extension through the rectal wall. No significant difference was observed between computed tomography and magnetic resonance imaging in assessing extension to the perivesical fat, adjacent organs, pelvic side wall, or lymph nodes. According to the TNM classification, magnetic resonance imaging correctly staged 74% (14/19) of carcinomas, while computed tomography correctly staged 68% (13/19).


Assuntos
Imageamento por Ressonância Magnética , Cuidados Pré-Operatórios , Neoplasias Retais/diagnóstico , Tomografia Computadorizada por Raios X , Idoso , Estudos de Avaliação como Assunto , Feminino , Humanos , Metástase Linfática , Imageamento por Ressonância Magnética/instrumentação , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Invasividade Neoplásica , Estadiamento de Neoplasias , Estudos Prospectivos , Neoplasias Retais/patologia , Reto/diagnóstico por imagem , Reto/patologia , Tomografia Computadorizada por Raios X/instrumentação , Tomografia Computadorizada por Raios X/métodos
12.
Leuk Lymphoma ; 37(3-4): 441-3, 2000 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10752997

RESUMO

We report here the case of a 68-year-old woman who presented severe renal failure following the first cycle of high dose methotrexate (HDMTX) for the treatment of a cerebral malignant lymphoma. Before HDMTX administration, serum creatinine value was normal and three days after HDMTX, it reached 457 micromol/L. Leucovorin rescue, hemodialysis and cholestyramine did not increase MTX clearance. Because of the persistence of renal failure, and the high risk of important hematological side-effects associated with high MTX plasma levels, the patient received carboxypeptidase G2 (CPDG2). This allowed MTX plasma levels to decrease by 80% in 15 minutes. No side effects were observed and renal function normalized rapidly. In some patients, when high-dose leucovorin associated with hemodialysis and cholestyramine are unable to restore normal MTX clearance, CPDG2 should be considered because it may represent a safe and efficient alternative for the management of MTX intoxication.


Assuntos
Metotrexato/efeitos adversos , Insuficiência Renal/induzido quimicamente , gama-Glutamil Hidrolase/uso terapêutico , Idoso , Neoplasias Encefálicas/sangue , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/urina , Feminino , Humanos , Infusões Intravenosas , Linfoma/sangue , Linfoma/tratamento farmacológico , Linfoma/urina , Metotrexato/administração & dosagem , Metotrexato/sangue , Metotrexato/urina
13.
Eur J Radiol ; 9(2): 115-8, 1989 May.
Artigo em Inglês | MEDLINE | ID: mdl-2663488

RESUMO

MRI findings in three cases of pseudomyxoma peritonei, in two cases associated with visceral invasion, are described. MR imaging using the same morphologic criteria as described in ultrasonography and CT suggested the diagnosis in all three cases. In T 1 weighted images (SE 400/28 ms) the hypointensity of signals of both implants and mucoid ascites was found to approach that of muscle tissue. In T 2 weighted images (SE 1600/40, 80, 120 ms), however, there was general hyperintensity of signals, which was more pronounced in mucoid ascites than in implants, and which approached signal intensities of water. Invasion of the viscera was very well depicted in all cases.


Assuntos
Imageamento por Ressonância Magnética , Pseudomixoma Peritoneal/diagnóstico , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Tomografia Computadorizada por Raios X , Ultrassonografia
14.
Eur J Radiol ; 17(2): 117-21, 1993 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-8223679

RESUMO

OBJECTIVE: The aim of this study is to analyze the ability of MR fat suppression techniques to characterize fat components of ovarian mature cystic teratomas (MCT) shown by CT. SUBJECTS AND METHODS: MR images of eight MCTs of the ovary were obtained using standard sequences followed by a SPIR (spectral presaturation with inversion recovery) sequence in six cases and by Dixon sequences in two cases. In all cases correlation with CT and pathologic findings was achieved. RESULTS: MR fat suppression sequences showed to be as accurate as CT in detecting fat inside the cystic part of the teratomas (8/8). CONCLUSION: MR fat suppression sequences should be performed when presence of fat is suspected on images of ovarian tumors produced by standard MR sequences.


Assuntos
Imageamento por Ressonância Magnética , Neoplasias Ovarianas/diagnóstico , Teratoma/diagnóstico , Tomografia Computadorizada por Raios X , Adulto , Feminino , Humanos , Imageamento por Ressonância Magnética/métodos , Neoplasias Ovarianas/diagnóstico por imagem , Teratoma/diagnóstico por imagem
15.
Eur J Radiol ; 20(2): 137-43, 1995 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-7588869

RESUMO

OBJECTIVE: To correlate CT and MR patterns of ovarian mature cystic teratomas (MCT). SUBJECTS AND METHODS: CT and MR findings in 25 histologically proven ovarian MCT were retrospectively reviewed. MCT characterization at CT and MR was based on detection of fat and/or a Rokitansky protuberance. MR signal intensity and CT density numbers of fat were correlated. RESULTS: At pathology, 24/25 tumors contained fat, 1/25 a water content, and 23/25 a Rokitansky protuberance. Twenty one MCT contained fat with a density number less than-20 HU (mean density: -95 HU) and a signal intensity superior or equal to sub-cutaneous fat on T1 images, however, only six of these had a signal intensity equal to sub-cutaneous fat on T1 and T2 images and 12 had a reversed chemical shift artifact. Three contained fat with a density number ranging from -13 to +8 HU and a signal intensity inferior to subcutaneous fat on T1 images. CT showed a Rokitansky protuberance in 21/23, containing adipose tissue in 16 and calcified structures in 21. Standard MR showed a Rokitansky protuberance in 14/23 and characterized adipose tissue in eight cases, and calcified material in six cases. Finally, CT characterized 24/25 (96%) MCT. Standard MR characterized 22/25 (88%) MCT, and standard MR with fat-suppression sequences characterized 23/25 (92%) MCT. CONCLUSION: Standard MR is less effective than CT in characterizing fat and has the same difficulty as CT in characterizing fat mixed with hair when its density is high. When fat cannot be identified by either technique, diagnosis of a Rokitansky protuberance is more easily made at CT than at MR.


Assuntos
Imageamento por Ressonância Magnética , Neoplasias Ovarianas/diagnóstico por imagem , Neoplasias Ovarianas/diagnóstico , Teratoma/diagnóstico por imagem , Teratoma/diagnóstico , Tomografia Computadorizada por Raios X , Adulto , Idoso , Estudos de Avaliação como Assunto , Feminino , Humanos , Pessoa de Meia-Idade , Estudos Retrospectivos
16.
Physiol Biochem Zool ; 74(4): 548-59, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11436139

RESUMO

Milk composition was investigated throughout the 10-mo pup-rearing period in subantarctic fur seals (Arctocephalus tropicalis) breeding on Amsterdam Island. The mean milk composition was 42.8% +/- 5.7% lipid, 12.1% +/- 1.5% protein, and 42.6% +/- 7.3% water. Subantarctic fur seals breeding on Amsterdam Island produced one of the richest milks ever reported in otariids (20.4 +/- 2.9 kJ/g), with lipid content contributing 85% of total gross energy. The high lipid levels measured in the milk of subantarctic fur seals breeding on Amsterdam Island is consistent (i) with the relatively long time lactating females spend at sea, due to the relatively poor local trophic conditions near the colony that necessitate that they travel long distances to reach the foraging grounds, and (ii) with the consequently short time mothers spend with their pups ashore. Milk composition changed according to the time mothers were fasting ashore: milk produced during the first 2 d spent ashore, when more than 80% of milk transfer occurred, had higher levels of lipids, proteins, and gross energy than milk produced later during the visit ashore, suggesting that the pups were fed with two types of milk during a suckling period. Throughout the year, mothers in good condition produced milk of higher lipid content than others, suggesting that individual foraging skills contribute to enhance milk quality. Milk lipid and gross energy content varied with pup age, according to quadratic relationships, increasing during the earlier stages of lactation before reaching asymptotic values when pups were 180 d old. The stage of lactation appears to be a better predictor of milk lipid content than the duration of the preceding foraging trip, suggesting that either changes in the nutritional requirements of the pup and/or seasonal changes in trophic conditions act on milk composition. These changes in milk quality may also be related to changes in maternal care; lactating subantarctic fur seals apparently reallocate their body reserves toward gestation rather than lactation at the end of the pup-rearing period.


Assuntos
Otárias/fisiologia , Lactação/fisiologia , Leite/metabolismo , Animais , Animais Lactentes , Peso Corporal , Comportamento Alimentar/fisiologia , Feminino , Otárias/metabolismo , Otárias/psicologia , Ilhas do Oceano Índico , Lactação/metabolismo , Lactação/psicologia , Metabolismo dos Lipídeos , Leite/química , Proteínas do Leite/metabolismo , Estações do Ano
17.
Radiat Med ; 6(1): 1-8, 1988.
Artigo em Inglês | MEDLINE | ID: mdl-3045897

RESUMO

The magnetic resonance (MR) examinations of six patients with intrahepatic calculi were reviewed retrospectively to 1) determine the ability of MR to demonstrate intrahepatic calculi and 2) assess the MR appearance of the stones. In five out of six cases, MRI demonstrated intrahepatic calculi. In three cases, stones exhibited a low intensity signal on the different spin echo (SE) sequences, as previously described by in vitro and in vivo studies. However in two other cases, a significant signal with short T1 and relatively long T2 relaxation times was noticed. These different features are discussed in relation to chemical and physical differences in intrahepatic calculi and compared with variable CT attenuation values of stones. MRI seems to provide complementary information concerning intrahepatic calculi.


Assuntos
Ductos Biliares Intra-Hepáticos , Colelitíase/diagnóstico , Adulto , Idoso , Doenças dos Ductos Biliares/diagnóstico , Doenças dos Ductos Biliares/diagnóstico por imagem , Colangiopancreatografia Retrógrada Endoscópica , Colelitíase/diagnóstico por imagem , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Tomografia Computadorizada por Raios X , Ultrassonografia
18.
J Radiol ; 69(5): 323-7, 1988 May.
Artigo em Francês | MEDLINE | ID: mdl-3042996

RESUMO

A multicentric form of Castleman's disease is described, this being a rare affection for which CT image characteristics have not, to our knowledge, been reported. Two cases of localized and one case of multicentric Castleman's disease are reported, and differential characters of these two forms with common histology: angio-follicular lymphoid hyperplasia, outlined. The localized form is found mainly in the mediastinum in young patients and follows a favorable course with recovery after exeresis. The diffuse form develops in later life and presents with severe systemic signs and a marked biological inflammatory syndrome Glands and viscera are affected and its course is grave, with mostly fatal relapses. Angiography suggests diagnosis when images show hypervascular lesions in lymph glands. CT scan imaging with contrast is very suggestive when glandular lesions are present that take up contrast strongly. This appearance should always raise the possibility of Castleman's disease.


Assuntos
Hiperplasia do Linfonodo Gigante/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Adulto , Idoso , Hiperplasia do Linfonodo Gigante/diagnóstico , Feminino , Humanos , Doenças Linfáticas/etiologia , Masculino , Fatores de Tempo
19.
J Radiol ; 71(5): 339-43, 1990 May.
Artigo em Francês | MEDLINE | ID: mdl-2213696

RESUMO

The protal system of 45 normal patients have been retrospectively studied on spin echo MRI sequences (interleaved cuts): multiple artifacts have been evaluated and 24% of them were visualized at the portal system level. Thus, partial volume effect responsible for almost 25% of the artifacts is not always easily seen on a single sequence. Respiratory and aortic artifacts can deteriorate the visualization of the vascular lumen but cannot be confused with a thrombosis. Well-known artifacts, as slice entry phenomenon and even echo rephasing, represent more than 60% of the artifacts: they are readily recognized when they are typical and indicate flowing blood. On the contrary, an other artifact, representing less than 5% of the total and seen at the level of the left portal vein, simulates a thrombus, on T2 weighed images. We conclude that the frequency and polymorphism of the artifacts are limiting factors of MRI value in the diagnosis of portal vein thrombosis.


Assuntos
Imageamento por Ressonância Magnética , Sistema Porta/anatomia & histologia , Trombose/diagnóstico , Adulto , Erros de Diagnóstico , Feminino , Humanos , Imageamento por Ressonância Magnética/efeitos adversos , Masculino , Estudos Retrospectivos
20.
J Radiol ; 71(1): 27-31, 1990 Jan.
Artigo em Francês | MEDLINE | ID: mdl-2179537

RESUMO

This observation illustrates how difficult it is to interpret the intravascular signal observed with MRI in cases of portal hypertension. A signal occupying the entire lumen of the portal trunk and branches can be seen, which is constantly observed in the axial as well as coronal planes in the 3 series studied. It is hypointense relative to the liver on T1-weighted images, hyperintense on T2-weighted images: this appearance therefore perfectly mimicks portal thrombosis. Ultrasound combined with pulsed Doppler demonstrates the stagnant blood within the patent portal system. This kind of artifact, which is produced by a very slow flow or even by the standstill of flow, is much more difficult to recognize than the common flow artifacts; the criteria put forward by various authors to distinguish between artifacts and thrombosis are of no avail in this case. Examinations must able to confirm or rule out portal thrombosis in the case of portal hypertension with deceleration of flow. In practice, ultrasound studies, combined with pulsed Doppler in the best cases, is therefore indicated as a first-intension technique.


Assuntos
Síndrome de Budd-Chiari/complicações , Hipertensão Portal/diagnóstico , Imageamento por Ressonância Magnética , Erros de Diagnóstico , Feminino , Humanos , Hipertensão Portal/etiologia , Pessoa de Meia-Idade , Veia Porta , Trombose/diagnóstico
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