156 resultados para Morphological features
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Purpose: 1. To review Ct features suggestive of saprophytic aspergillosis (aspergilloma) and to correlate them with the final pathological results. 2. To illustrate the wide range of differential diagnosis. Methods and materials: The electronic database of our department from 1995 to 2007 revealed CT reports of 48 patients that had been considered very suggestive of aspergilloma. Two radiologists with 6 and 12 years experience in thoracic radiology jointly reviewed the corresponding CT features including ancillary findings and the underlying lung diseases and correlated them with the final pathological diagnosis. Results: Forty patients could be included in the study (12 women, mean age 52), while in 8 patients there was no adequate clinical follow-up. In 17 patients the diagnosis "mycetoma" due to aspergillus fumigatus infection was confirmed, either by surgery, biopsy or bronchoscopy. In 23 patients, differential diagnoses were found, such as cavitating bronchial carcinoma (n = 7), bacterial abscess (n = 3), typical (n = 2) and atypical (n = 2) tuberculosis, as well as inflammatory changes due to mucoviscidosis (n = 1), Wegener's disease (n = 1) or chronic obstructive pulmonary disease (n = 3). Fibromyxoide hamartoma, lung infarction and bronchomucocele were responsible for the typical CT feature in one patient each. Conclusion: 1. The typical CT feature suggesting mycetoma is softtissue proliferation within a pre-existing wall-thickened lung cavity, oten even considered "pathognomonic". However, this diagnosis was finally confirmed by surgery or laboratory findings in less than 50% of patients only. 2. Since differential diagnoses are very large, not only including cavitating lung cancer and tuberculosis, the individual underlying lung disease needs strongly being taken into account often giving the best clue for the correct diagnosis.
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Résumé -Caractéristiques architecturales des génomes bactériens et leurs applications Les bactéries possèdent généralement un seul chromosome circulaire. A chaque génération, ce chromosome est répliqué bidirectionnellement, par deux complexes enzymatiques de réplication se déplaçant en sens opposé depuis l'origine de réplication jusqu'au terminus, situé à l'opposé. Ce mode de réplication régit l'architecture du chromosome -l'orientation des gènes par rapport à la réplication, notamment - et est en grande partie à l'origine des pressions qui provoquent la variation de la composition en nucléotides du génome, hors des contraintes liées à la structure et à la fonction des protéines codées sur le chromosome. Le but de cette thèse est de contribuer à quantifier les effets de la réplication sur l'architecture chromosomique, en s'intéressant notamment aux gènes des ARN ribosomiques, cruciaux pour la bactérie. D'un autre côté, cette architecture est spécifique à l'espèce et donne ainsi une «identité génomique » aux gènes. Il est démontré ici qu'il est possible d'utiliser des marqueurs «naïfs » de cette identité pour détecter, notamment dans le génome du staphylocoque doré, des îlots de pathogénicité, qui concentrent un grand nombre de facteurs de virulence de la bactérie. Ces îlots de pathogénicité sont mobiles, et peuvent passer d'une bactérie à une autre, mais conservent durant un certain temps l'identité génomique de leur hôte précédent, ce qui permet de les reconnaître dans leur nouvel hôte. Ces méthodes simples, rapides et fiables seront de la plus haute importance lorsque le séquençage des génomes entiers sera rapide et disponible à très faible coût. Il sera alors possible d'analyser instantanément les déterminants pathogéniques et de résistance aux antibiotiques des agents pathogènes. Summary The bacterial genome is a highly organized structure, which may be referred to as the genome architecture, and is mainly directed by DNA replication. This thesis provides significant insights in the comprehension of the forces that shape bacterial chromosomes, different in each genome and contributing to confer them an identity. First, it shows the importance of the replication in directing the orientation of prokaryotic ribosomal RNAs, and how it shapes their nucleotide composition in a tax on-specific manner. Second, it highlights the pressure acting on the orientation of the genes in general, a majority of which are transcribed in the same direction as replication. Consequently, apparent infra-arm genome rearrangements, involving an exchange of the leading/lagging strands and shown to reduce growth rate, are very likely artifacts due to an incorrect contig assembly. Third, it shows that this genomic identity can be used to detect foreign parts in genomes, by establishing this identity for a given host and identifying the regions that deviate from it. This property is notably illustrated with Staphylococcus aureus: known pathogenicity islands and phages, and putative ancient pathogenicity islands concentrating many known pathogenicity-related genes are highlighted; the analysis also detects, incidentally, proteins responsible for the adhesion of S. aureus to the hosts' cells. In conclusion, the study of nucleotide composition of bacterial genomes provides the opportunity to better understand the genome-level pressures that shape DNA sequences, and to identify genes and regions potentially related to pathogenicity with fast, simple and reliable methods. This will be of crucial importance when whole-genome sequencing will be a rapid, inexpensive and routine tool.
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Purpose: To work out certain, well-defined aetiologies frequently associated with mesenteric venous thrombosis (MVT) in order to predict a typical population at risk, since MVT is nowadays often incidentally detected on cross-sectional imaging. To demonstrate the MDCT features, frequency and extent of associated bowel ischemia according to the underlying pathology. Methods and materials: Our electronic database revealed 71 patients (25 women, mean age 55) with thrombosis of the superior and/or inferior mesenteric vein detected by MDCT between 2000 and 2008. Two radiologists jointly reviewed the corresponding MDCT features including intraluminal extension, underlying aetiology and associated bowel ischemia, if present. Results: MVT was associated with carcinoma in 31 (43.7%) patients (pancreas 21.1%, liver 9.9%, others 12.7%). Concomitant inflammation was seen in 15 (21.1%) patients (pancreatitis 11.3%, diverticulitis 4.2%, others 5.6%), whereas coagulation/hematologic disorders were found in 7 (9.9%) patients, liver cirrhosis in 6 (8.5%), mixed/miscellaneous causes in 5 (7%) and still unknown aetiologies in 5 patients (7%). MVT resulted from recent operations in 2 (2.8%) patients. MDCT features of venous bowel ischemia were present in 15 patients (21.1%). 46.5% of MVT were (sub) acute, while 53.5% chronic. The luminal extension was complete in 52.1%, subtotal (>50% of lumen) in 22.5% and partial (<50% of lumen) in 25.4% of patients, consisting either of blood clots (76.1%) or tumoral tissue (23.9%), the latter mainly due to pancreas adenocarcinoma (76.4%). Conclusion: MDCT features of MVT are seen with a wide range of underlying diseases. Signs of intestinal ischemia are infrequently associated, mostly occurring with coagulation/hematologic disorders (40%).
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BACKGROUND: Neurodegeneration with brain iron accumulation (NBIA) refers to genetically heterogenous paediatric neurodegenerative disorders characterised by basal ganglia iron deposition. One major cause is recessive mutations in the PLA2G6 gene. While strabismus and optic nerve pallor have been reported for PLA2G6-related disease, the ophthalmic phenotype is not carefully defined. In this study we characterise the ophthalmic phenotype of PLA2G6-related NBIA. METHODS: Prospective cohort study. RESULTS: The eight patients were 4-26 years old when examined. All had progressive cognitive and motor regression first noted between 9 months and 6 years of age that typically first manifested as difficulty walking (ataxia). Ophthalmic examination was sometimes limited by cognitive ability. Four of eight had exotropia, 7/7 bilateral supraduction defect, 5/7 poor convergence, 6/8 saccadic pursuit, 4/8 saccadic intrusions that resembled square-wave jerks, and 8/8 bilateral optic nerve head pallor. All patients lacked Bell phenomenon. CONCLUSIONS: Upgaze palsy, although not a previously reported finding, was confirmed in all patients (except in one for whom assessment could not be performed) and thus can be considered part of the phenotype in children and young adults. Other frequent findings not previously highlighted were abnormal convergence, saccadic pursuit, and saccadic intrusions. Optic nerve head pallor and strabismus, previously reported findings in the disease, were found in 100% and 50% of our cohort, respectively, and the strabismus in our series was always exotropia. Taken together, these clinical findings may be helpful in distinguishing PLA2G6-related neurodegeneration from the other major cause of NBIA, recessive PANK2 mutations.
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Purpose: To assess the visibility and the features of ECUATS on 3.0-T MRI studies, and evaluate their correlation with tendinosis. Methods and materials: Our retrospective study was approved by IRB, with waiver of informed consent. Fifty wrist MRI and 48 MR arthrographies from 98 patients (55 males, 43 females, mean age 42.3 years) performed between January and November 2009 on 3.0-T units were reviewed. Images (transverse T1, T2, FS Gd T1 and VIBE) were independently analyzed by two radiologists, and a consensus reached with a third reader in case of disagreement. The visibility of ECUATS was assessed on each available transverse sequence. When present, ECUATS' origins, diameters and insertions were noted. ECU tendinosis was also evaluated. Inter-rater agreement was assessed using Cohen's Kappa coefficient. Results: ECUATS observed prevalence was 23.5% (23/98). ECUATS were more frequently noted on the VIBE sequence, with a good inter-rater agreement (Kappa = 0.72). Origins were noted in 95.7% of cases: 3 were at the level of, and 20 distal to ECU subsheath. Insertions were seen in 43.5%: 2 were on 5th metacarpal bone, 8 on extensor apparatus of 5th finger. ECUATS mean shortest and longest diameters were 0.54 and 0.85 mm respectively. ECU tendinosis was statistically more frequently noted in patients with ECUATS (p <0.05). Conclusion: ECUATS are readily visible on 3.0-T MRI studies, especially on transverse GRE VIBE images. ECU tendinosis is more frequently noted in patients bearing ECUATS.
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Oculo-auriculo-vertebral spectrum is a complex developmental disorder characterised mainly by anomalies of the ear, hemifacial microsomia, epibulbar dermoids and vertebral anomalies. The aetiology is largely unknown, and the epidemiological data are limited and inconsistent. We present the largest population-based epidemiological study to date, using data provided by the large network of congenital anomalies registries in Europe. The study population included infants diagnosed with oculo-auriculo-vertebral spectrum during the 1990-2009 period from 34 registries active in 16 European countries. Of the 355 infants diagnosed with oculo-auriculo-vertebral spectrum, there were 95.8% (340/355) live born, 0.8% (3/355) fetal deaths, 3.4% (12/355) terminations of pregnancy for fetal anomaly and 1.5% (5/340) neonatal deaths. In 18.9%, there was prenatal detection of anomaly/anomalies associated with oculo-auriculo-vertebral spectrum, 69.7% were diagnosed at birth, 3.9% in the first week of life and 6.1% within 1 year of life. Microtia (88.8%), hemifacial microsomia (49.0%) and ear tags (44.4%) were the most frequent anomalies, followed by atresia/stenosis of external auditory canal (25.1%), diverse vertebral (24.3%) and eye (24.3%) anomalies. There was a high rate (69.5%) of associated anomalies of other organs/systems. The most common were congenital heart defects present in 27.8% of patients. The prevalence of oculo-auriculo-vertebral spectrum, defined as microtia/ear anomalies and at least one major characteristic anomaly, was 3.8 per 100,000 births. Twinning, assisted reproductive techniques and maternal pre-pregnancy diabetes were confirmed as risk factors. The high rate of different associated anomalies points to the need of performing an early ultrasound screening in all infants born with this disorder.
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In this paper, mixed spectral-structural kernel machines are proposed for the classification of very-high resolution images. The simultaneous use of multispectral and structural features (computed using morphological filters) allows a significant increase in classification accuracy of remote sensing images. Subsequently, weighted summation kernel support vector machines are proposed and applied in order to take into account the multiscale nature of the scene considered. Such classifiers use the Mercer property of kernel matrices to compute a new kernel matrix accounting simultaneously for two scale parameters. Tests on a Zurich QuickBird image show the relevance of the proposed method : using the mixed spectral-structural features, the classification accuracy increases of about 5%, achieving a Kappa index of 0.97. The multikernel approach proposed provide an overall accuracy of 98.90% with related Kappa index of 0.985.
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Zebrafish and Xenopus have become popular model organisms for studying vertebrate development of many organ systems, including the heart. However, it is not clear whether the single ventricular hearts of these species possess any equivalent of the specialized ventricular conduction system found in higher vertebrates. Isolated hearts of adult zebrafish (Danio rerio) and African toads (Xenopus laevis) were stained with voltage-sensitive dye and optically mapped in spontaneous and paced rhythms followed by histological examination focusing on myocardial continuity between the atrium and the ventricle. Spread of the excitation wave through the atria was uniform with average activation times of 20 +/- 2 and 50 +/- 2 ms for zebrafish and Xenopus toads, respectively. After a delay of 47 +/- 8 and 414 +/- 16 ms, the ventricle became activated first in the apical region. Ectopic ventricular activation was propagated significantly more slowly (total ventricular activation times: 24 +/- 3 vs. 14 +/- 2 ms in zebrafish and 74 +/- 14 vs. 35 +/- 9 ms in Xenopus). Although we did not observe any histologically defined tracts of specialized conduction cells within the ventricle, there were trabecular bands with prominent polysialic acid-neural cell adhesion molecule staining forming direct myocardial continuity between the atrioventricular canal and the apex of the ventricle; i.e., the site of the epicardial breakthrough. We thus conclude that these hearts are able to achieve the apex-to-base ventricular activation pattern observed in higher vertebrates in the apparent absence of differentiated conduction fascicles, suggesting that the ventricular trabeculae serve as a functional equivalent of the His-Purkinje system.
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Multiple epiphyseal dysplasia (MED) is a genetically heterogeneous group of diseases characterized by variable degrees of epiphyseal abnormality primarily involving the hip and knee joints. The purpose of this study was to investigate the frequency of mutations in individuals with a clinical and radiographic diagnosis of MED and to test the hypothesis that characteristic radiological findings may be helpful in predicting the gene responsible. The radiographs of 74 Korean patients were evaluated by a panel of skeletal dysplasia experts. Six genes known to be associated with MED (COMP, MATN3, COL9A1, COL9A2, COL9A3, and DTDST) were screened by sequencing. Mutations were found in 55 of the 63 patients (87%). MATN3 mutations were found in 30 patients (55%), followed by COMP mutations in 23 (41%), and COL9A2 and DTDST mutations in one patient (2%) each. Comparisons of radiographic findings in patients with COMP and MATN3 mutations showed that albeit marked abnormalities in hip and knee joints were observed in both groups, the degree of involvement and the morphology of dysplastic epiphyses differed markedly. The contour of the pelvic acetabulum, the presence of metaphyseal vertical striations, and/or the brachydactyly of the hand were also found to be highly correlated with the genotypes. The study confirms that MATN3 and COMP are the genes most frequently responsible for MED and that subtle radiographic signs may give precious indications on which gene(s) should be prioritized for mutational screening in a given individual.
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T cell lymphoma of γδ T cell origin is a rare disease that mainly involves extranodal sites and shows aggressive clinical behavior. Here, we report a case of primary γδ T cell lymphoma of the lungs with epitheliotropism in the respiratory epithelium, a feature somewhat reminiscent of what is observed in enteropathy-associated T cell lymphoma. A 63-year-old man presented with chest pain and dyspnea on exertion, weight loss, and general weakness. On a positron emission tomography (PET) scan, multiple hypermetabolic lesions were found in both lungs. Microscopic examination of the wedge lung biopsy revealed nodular infiltration of monomorphic, medium- to large-sized atypical lymphocytes with round nuclei, coarse chromatin, and a variable amount of clear to eosinophilic cytoplasm. Of note, intraepithelial lymphocytosis by atypical lymphoid cells was observed in the respiratory epithelium within and around the nodule. Immunohistochemically, the tumor cells were CD3+, TCRβF1-, TCRγ+, CD5-, CD7+, CD20-, CD79a-, CD30-, CD4-, CD8-, CD10-, BCL6-, CD21-, CD56+, CD57-, and CD138-, and expressed cytotoxic molecules. Epstein-Barr virus (EBV) was not detected by an in situ hybridization assay for EBV-encoded RNA. Interestingly, CD103 was expressed by a subset of tumor cells, especially those infiltrating the epithelium. T cell clonality was detected by multiplex PCR analysis of TRG and TRD gene rearrangements. After 2 months of systemic chemotherapy, PET scan showed regression of the size and metabolic activity of the lesions. This case represents a unique γδ T cell lymphoma of the lungs showing epitheliotropism by CD103+ γδ T cells that is suggestive of tissue-resident γδ T cells as the cell of origin.
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In 2004, a 56-year-old woman was diagnosed with Stage IA follicular lymphoma in a cervical lymph node biopsy. The patient experienced total remission after local radiation therapy. In 2009, a control computed tomography scan evidenced a pelvic mass, prompting total hysterectomy. The latter harbored a 4.8-cm intramural uterine tumor corresponding to a mostly diffuse and focally nodular proliferation of medium to large cells, with extensive, periodic acid-Schiff negative, signet ring cell changes, and a pan-keratin negative, CD20+, CD10+, Bcl2+, Bcl6+ immunophenotype. Molecular genetic studies showed the same clonal IGH gene rearrangement in the lymph node and the uterus, establishing the uterine tumor as a relapse of the preceding follicular lymphoma, although no signet ring cells were evidenced at presentation. Uterine localization of lymphomas is rare, and lymphomas with signet ring cell features are uncommon. This exceptional case exemplifies a diagnostically challenging situation and expands the differential diagnosis of uterine neoplasms displaying signet ring cell morphology.
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Inactivating mutations of the Ten-Eleven Translocation 2 (TET2) gene were first identified in myeloid malignancies and more recently in peripheral T-cell lymphomas (PTCLs). In the present study, we investigated the presence of TET2 coding sequence mutations and their clinical relevance in a large cohort of 190 PTCL patients. TET2 mutations were identified in 40 of 86 (47%) cases of angioimmunoblastic T-cell lymphoma (AITL) and in 22 of 58 (38%) cases of peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS), but were absent in all other PTCL entities, with the exception of 2 of 10 cases of enteropathy-associated T-cell lymphoma. Among PTCL-NOS, a heterogeneous group of lymphoma-comprising cases likely to derive from Th follicular (T(FH)) cells similarly to AITL, TET2 mutations were more frequent when PTCL-NOS expressed T(FH) markers and/or had features reminiscent of AITL (58% vs 24%, P = .01). In the AITL and PTCL-NOS subgroups, TET2 mutations were associated with advanced-stage disease, thrombocytopenia, high International Prognostic Index scores, and a shorter progression-free survival.
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AbstractMyotonic dystrophy type 1 (DM1), also known as Steinert's disease, is an inherited autosomal dominant disease. DM1 is characterized by myotonia, muscular weakness and atrophy, but it has a multisystemic phenotype. The genetic basis of the disease is the abnormal expansion of CTG repeats in the 3' untranslated region of the DM protein kinase (DMPK) gene on chromosome 19. The size of the expansion correlates to the severity of the disease and the age of onset.Respiratory problems have long been recognized to be a major feature of the disease and are the main factor contributing to mortality ; however the mechanisms are only partly known. The aim of our study is to investigate whether respiratory failure results only from the involvement of the dystrophic process at the level of the respiratory muscles or comes also from abnormalities in the neuronal network that generates and controls the respiratory rhythm. The generation of valid transgenic mice displaying the human DM1 phenotype by the group of Dr. Gourdon provided us a useful tool to analyze the brain stem respiratory neurons, spinal phrenic motoneurons and phrenic nerves. We examined therefore these structures in transgenic mice carrying 350-500 CTGs and displaying a mild form of the disease (DM1 mice). The morphological and morphometric analysis of diaphragm muscle sections revealed a denervation of the end-plates (EPs), characterized by a decrease in size and shape complexity of EPs and a reduction in the density of acetylcholine receptors (AChRs). Also a strong and significant reduction in the number of phrenic unmyelinated fibers was detected, but not in the myelinated fibers. In addition, no pathological changes were detected in the cervical motoneurons and medullary respiratory centers (Panaite et al., 2008). These results suggest that the breathing rhythm is probably not affected in mice expressing a mild form of DM1, but rather the transmission of action potentials at the level of diaphragm NMJs is deficient.Because size of the mutation increases over generations, new transgenic mice were obtained from the mice with 350-500 CTGs, resulting from a large increase of CTG repeat in successive generations, these mice carry more than 1300 CTGs (DMSXL) and display a severe DM1 phenotype (Gomes-Pereira et al., 2007). Before we study the mechanism underlying the respiratory failure in DMSXL mice, we analyzed the peripheral nervous system (PNS) in these mice by electrophysiological, histological and morphometric methods. Our results provide strong evidence that DMSXL mice have motor neuropathy (Panaite et al., 2010, submitted). Therefore the DMSXL mice expressing severe DM1 features represent for us a good tool to investigate, in the future, the physiological, structural and molecular alterations underlying respiratory failure in DM1. Understanding the mechanism of respiratory deficiency will help to better target the therapy of these problems in DM1 patients. In addition our results may, in the future, orientate pharmaceutical and clinical research towards possible development of therapy against respiratory deficits associated with the DM1.RésuméLa dystrophic myotonique type 1 (DM1), aussi dénommée maladie de Steinert, est une maladie héréditaire autosomique dominante. Elle est caractérisée par une myotonie, une faiblesse musculaire avec atrophie et se manifeste aussi par un phénotype multisystémique. La base génétique de la maladie est une expansion anormale de répétitions CTG dans une région non traduite en 3' du gène de la DM protéine kinase (DMPK) sur le chromosome 19. La taille de l'expansion est corrélée avec la sévérité et l'âge d'apparition de DM1.Bien que les problèmes respiratoires soient reconnus depuis longtemps comme une complication de la maladie et soient le principal facteur contribuant à la mortalité, les mécanismes en sont partiellement connus. Le but de notre étude est d'examiner si l'insuffisance respiratoire de la DM1 est dû au processus dystrophique au niveau des muscles respiratoires ou si elle est entraînée aussi par des anomalies dans le réseau neuronal qui génère et contrôle le rythme respiratoire. La production par le groupe du Dr. Gourdon de souris transgéniques de DM1, manifestant le phénotype de DM1 humaine, nous a fourni un outil pour analyser les nerfs phréniques, les neurones des centres respiratoires du tronc cérébral et les motoneurones phréniques. Par conséquence, nous avons examiné ces structures chez des souris transgéniques portant 350-500 CTG et affichant une forme légère de la maladie (souris DM1). L'analyse morphologique et morphométrique des sections du diaphragme a révélé une dénervation des plaques motrices et une diminution de la taille et de la complexité de la membrane postsynaptîque, ainsi qu'une réduction de la densité des récepteurs à l'acétylcholine. Nous avons aussi détecté une réduction significative du nombre de fibres nerveuses non myélinisées mais pas des fibres myélinisées. Par ailleurs, aucun changement pathologique n'a été détecté pour les neurones moteurs médullaires cervicaux et centres respiratoires du tronc cérébral (Panaite et al., 2008). Ces résultats suggèrent que le iythme respiratoire n'est probablement pas affecté chez les souris manifestant une forme légère du DM1, mais plutôt que la transmission des potentiels d'action au niveau des plaques motrices du diaphragme est déficiente.Comme la taille du mutation augmente au fil des générations, de nouvelles souris transgéniques ont été générés par le groupe Gourdon; ces souris ont plus de 1300 CTG (DMSXL) et manifestent un phénotype sévère du DM1 (Gomes-Pereira et al., 2007). Avant d'étudier le mécanisme sous-jacent de l'insuffisance respiratoire chez les souris DMSXL, nous avons analysé le système nerveux périphérique chez ces souris par des méthodes électrophysiologiques, histologiques et morphométriques. Nos résultats fournissent des preuves solides que les souris DMSXL manifestent une neuropathie motrice (Panaite et al., 2010, soumis). Par conséquent, les souris DMSXL représentent pour nous un bon outil pour étudier, à l'avenir, les modifications physiologiques, morphologiques et moléculaires qui sous-tendent l'insuffisance respiratoire du DM1. La connaissance du mécanisme de déficience respiratoire en DM1 aidera à mieux cibler le traitement de ces problèmes aux patients. De plus, nos résultats pourront, à l'avenir, orienter la recherche pharmaceutique et clinique vers le développement de thérapie contre le déficit respiratoire associé à DM1.