967 resultados para veterinary pathology


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With the free movement of people in the European Union, medical mobility has increased significantly. This is notably the case for disciplines for which shortage of well-trained staff has occurred. Pathology is among those specialties and effectively the discipline is confronted with a striking increase in mobility among trainees and qualified specialists. The presumption underlying unlimited mobility is that the competencies of the medical specialists in the European countries are more or less equal, including significant similarities in the postgraduate training programs. In order to assess whether reality corresponds with this presumption, we conducted a survey of the content and practice requirements of the curricula in the EU and affiliated countries. The results indicate a striking heterogeneity in the training program content and practice requirements. To name a few elements: duration of the training program varied between 4 and 6 years; the number of autopsies required varied between none at all and 300; the number of biopsies required varied between none at all and 15,000. We conclude that harmonization of training outcomes in Europe is a goal that needs to be pursued. This will be difficult to reach through harmonization of training programs, as these are co-determined by political, cultural, and administrative factors, difficult to influence. Harmonization might be attained by defining the general and specific competencies at the end of training and subsequent testing them through a test to which all trainees in Europe are subjected.

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Peripheral T-cell lymphomas (PTCLs) are heterogeneous and uncommon malignancies characterized by a usually aggressive clinical course. The current World Health Organization (WHO) classification delineates many entities grouped according to the clinical presentation as predominantly leukemic, cutaneous, extranodal, or nodal diseases. Yet, few genetic lesions serve as entity-defining markers. Using high-throughput methods, new recurrent genetic and molecular alterations are being discovered that are expected to refine the current classification and serve as diagnostic genetic markers and targets for novel therapies. There is increasing evidence that certain cellular subsets, in particular follicular helper T cells and gamma delta T cells, represent important defining markers and/or determinants of the biology of certain entities; nevertheless, the cellular derivation of many PTCL entities remains poorly characterized and there is evidence of plasticity in terms of cellular derivation (alpha-beta, gamma-delta, natural killer [NK]) especially in several extranodal entities with a cytotoxic profile. While most clonal NK/T-cell proliferations are in general highly malignant, some more indolent forms of NK or T-cell lympho-proliferations are being identified.

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The development of psoriatic plaques is T cell dependent. Recently, Th17 CD4 T cells have been proposed to be the main effector cells. However, development of psoriasis is critically dependent on accumulation of epidermal T cells, among the majority express CD8. Here we show that numbers of epidermal CD8 T cells correlated with development of psoriasis in human biopsies, and that blockade of CD8 T cells by depleting antibodies inhibited development of psoriasis in the AGR xenotransplantation mouse model. In human dermis, both CD4 and CD8 T cell numbers correlated significantly with epidermal pathology, indicating a role for dermal CD4 T cells in orchestrating the development of psoriasiform changes induced by epidermis-infiltrating CD8 T cells.

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Background In a previous study, the European Organisation for Research and Treatment of Cancer (EORTC) reported a scoring system to predict survival of patients with low-grade gliomas (LGGs). A major issue in the diagnosis of brain tumors is the lack of agreement among pathologists. New models in patients with LGGs diagnosed by central pathology review are needed. Methods Data from 339 EORTC patients with LGGs diagnosed by central pathology review were used to develop new prognostic models for progression-free survival (PFS) and overall survival (OS). Data from 450 patients with centrally diagnosed LGGs recruited into 2 large studies conducted by North American cooperative groups were used to validate the models. Results Both PFS and OS were negatively influenced by the presence of baseline neurological deficits, a shorter time since first symptoms (<30 wk), an astrocytic tumor type, and tumors larger than 5 cm in diameter. Early irradiation improved PFS but not OS. Three risk groups have been identified (low, intermediate, and high) and validated. Conclusions We have developed new prognostic models in a more homogeneous LGG population diagnosed by central pathology review. This population better fits with modern practice, where patients are enrolled in clinical trials based on central or panel pathology review. We could validate the models in a large, external, and independent dataset. The models can divide LGG patients into 3 risk groups and provide reliable individual survival predictions. Inclusion of other clinical and molecular factors might still improve models' predictions.

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Postmortem imaging, including postmortem computed tomography angiography, has become an integral tool in forensic investigation in recent years. A relatively new technique, multiphase postmortem computed tomography angiography, allows detailed visualization of the vascular system and makes it possible to evaluate the dynamic perfusion of aortic branches, including the coronary arteries. Here, we report a case of aortic dissection involving the ascending aorta (type A) with coronary and carotid malperfusion. This case illustrates the complementary use of many of the diagnostic tools that are now available in forensic practice, from imaging to conventional autopsy to pathologic techniques such as immunohistochemistry.

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Glioblastoma (GBM) is a morphologically heterogeneous tumor type with a median survival of only 15 months in clinical trial populations. However, survival varies greatly among patients. As part of a central pathology review, we addressed the question if patients with GBM displaying distinct morphologic features respond differently to combined chemo-radiotherapy with temozolomide. Morphologic features were systematically recorded for 360 cases with particular focus on the presence of an oligodendroglioma-like component and respective correlations with outcome and relevant molecular markers. GBM with an oligodendroglioma-like component (GBM-O) represented 15% of all confirmed GBM (52/339) and was not associated with a more favorable outcome. GBM-O encompassed a pathogenetically heterogeneous group, significantly enriched for IDH1 mutations (19 vs. 3%, p = 0.003) and EGFR amplifications (71 vs. 48%, p = 0.04) compared with other GBM, while co-deletion of 1p/19q was found in only one case and the MGMT methylation frequency was alike (47 vs. 46%). Expression profiles classified most of the GBM-O into two subtypes, 36% (5/14 evaluable) as proneural and 43% as classical GBM. The detection of pseudo-palisading necrosis (PPN) was associated with benefit from chemotherapy (p = 0.0002), while no such effect was present in the absence of PPN (p = 0.86). In the adjusted interaction model including clinical prognostic factors and MGMT status, PPN was borderline nonsignificant (p = 0.063). Taken together, recognition of an oligodendroglioma-like component in an otherwise classic GBM identifies a pathogenetically mixed group without prognostic significance. However, the presence of PPN may indicate biological features of clinical relevance for further improvement of therapy.

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Fragile X-associated tremor/ataxia syndrome (FXTAS) is an adult-onset neurodegenerative disorder associated with premutation alleles of the fragile X mental retardation 1 (FMR1) gene. Approximately 40% of older male premutation carriers, and a smaller proportion of females, are affected by FXTAS; due to the lower penetrance the characterization of the disorder in females is much less detailed. Core clinical features of FXTAS include intention tremor, cerebellar gait ataxia and frequently parkinsonism, autonomic dysfunction and cognitive deficits progressing to dementia in up to 50% of males. In this study, we report the clinical, molecular and neuropathological findings of eight female premutation carriers. Significantly, four of these women had dementia; of the four, three had FXTAS plus dementia. Post-mortem examination showed the presence of intranuclear inclusions in all eight cases, which included one asymptomatic premutation carrier who died from cancer. Among the four subjects with dementia, three had sufficient number of cortical amyloid plaques and neurofibrillary tangles to make Alzheimer's disease a highly likely cause of dementia and a fourth case had dementia with cortical Lewy bodies. Dementia appears to be more common than originally reported in females with FXTAS. Although further studies are required, our observation suggests that in a portion of FXTAS cases there is Alzheimer pathology and perhaps a synergistic effect on the progression of the disease may occur.

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To complement the existing treatment guidelines for all tumour types, ESMO organises consensus conferences to focus on specific issues in each type of tumour. The Second ESMO Consensus Conference on Lung Cancer was held on 11-12 May 2013 in Lugano. A total of 35 experts met to address several questions on management of patients with non-small-cell lung cancer (NSCLC) in each of four areas: pathology and molecular biomarkers, early stage disease, locally advanced disease and advanced (metastatic) disease. For each question, recommendations were made including reference to the grade of recommendation and level of evidence. This consensus paper focuses on recommendations for pathology and molecular biomarkers in relation to the diagnosis of lung cancer, primarily non-small-cell carcinomas.

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Cocaine is a well known trigger of acute coronary syndromes. Over the last 10 years levamisole, a veterinary anthelminthic drug has been increasingly used as an adulterant of cocaine. Levamisole was used to treat pediatric nephritic syndrome and rheumatoid arthritis before being withdrawn from the market due to its significant toxicity, i.e. hematological complications and vasculitis. The major complications of levamisole-adultered cocaine reported up to now are hematological and dermatological. The case reported here is of a 25 year old man with a history of cocaine abuse who died at home after complaining of retrosternal pain. Postmortem CT-angiography, autopsy, and chemical and toxicological analyses were performed. An eroded coronary artery plaque was found at the proximal segment of the left anterior descending coronary artery. Two myocardial infarct scars were present in the left ventricle. Microscopic examination of the coronary artery revealed infiltration of eosinophils into the adventitia and intima. Toxicological examination confirmed the presence of cocaine and its metabolites in the peripheral blood, and of levamisole in the urine and pericardial fluid. Eosinophilic inflammatory coronary artery pathologies have been clinically linked to coronary dissection, hypersensitivity coronary syndrome and vasospastic allergic angina. The coronary pathology in the presented case could be a complication of levamisole-adultered cocaine use, in which an allergic or immune-mediated mechanism might play a role. The rise in cocaine addiction worldwide and the increase of levamisole adulterated cocaine highlights the importance of updating our knowledge of the effects of adultered cocaine abuse.

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Forensic experts play a major role in the legal process as they offer professional expert opinion and evidence within the criminal justice system adjudicating on the innocence or alleged guilt of an accused person. In this respect, medico-legal examination is an essential part of the investigation process, determining in a scientific way the cause(s) and manner of unexpected and/or unnatural death or bringing clinical evidence in case of physical, psychological, or sexual abuse in living people. From a legal perspective, these types of investigation must meet international standards, i.e., it should be independent, effective, and prompt. Ideally, the investigations should be conducted by board-certified experts in forensic medicine, endowed with a solid experience in this field, without any hierarchical relationship with the prosecuting authorities and having access to appropriate facilities in order to provide forensic reports of high quality. In this respect, there is a need for any private or public national or international authority including non-governmental organizations seeking experts qualified in forensic medicine to have at disposal a list of specialists working in accordance with high standards of professional performance within forensic pathology services that have been successfully submitted to an official accreditation/certification process using valid and acceptable criteria. To reach this goal, the National Association of Medical Examiners (NAME) has elaborated an accreditation/certification checklist which should be served as decision-making support to assist inspectors appointed to evaluate applicants. In the same spirit than NAME Accreditation Standards, European Council of Legal Medicine (ECLM) board decided to set up an ad hoc working group with the mission to elaborate an accreditation/certification procedure similar to the NAME's one but taking into account the realities of forensic medicine practices in Europe and restricted to post-mortem investigations. This accreditation process applies to services and not to individual practitioners by emphasizing policies and procedures rather than professional performance. In addition, the standards to be complied with should be considered as the minimum standards needed to get the recognition of performing and reliable forensic pathology service.

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Tailoring adjuvant therapy in breast cancer patients relies on prognostic and predictive factors, most of which are currently established by histopathological analysis of tumors. The quality of the assessment of the former (i.e.: tumor size, lymph node status, tumor grade, HER2 status, and lymphovascular invasion) and the latter (estrogen and progesteron receptors expression, HER2 overexpression or amplification) is an essential prerequisite for an optimal therapeutic decision. If the prognostic and predictive values of multigenes signatures are confirmed by on-going clinical studies, this approach could enter the clinical practice in the coming years and result in improved accuracy of adjuvant therapies in breast cancer patients. This approach might especially allow avoiding overtreatment in patients at low risk of recurrence.

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Résumé : Le virus de la maladie de Carré (en anglais: canine distemper virus, CDV) qui est pathogène pour les chiens et autres carnivores, est très semblable au virus de la rougeole humaine (en anglais MV). Ces deux virus font partie du genre des Morbillivirus qui appartient à la famille des Paramyxoviridae. Ils induisent des complications dans le système nerveux central (SNC). Au stade précoce et aigu de l'infection du SNC, le CDV induit une démyélinisation (1). Ce stade évolue dans certains cas vers une infection chronique avec progression de la démyélinisation. Pendant le stade précoce, qui suit en général de trois semaines les premiers symptômes, le processus de démyélinisation est associé à la réplication du virus et n'est pas considéré comme inflammatoire (1). Par contre, au stade chronique, la progression des plaques de démyélinisation semble être plutôt liée à des processus immunogènes caractéristiques (2), retrouvés également dans la sclérose en plaques (SEP) chez les humains. Pour cette raison, le CDV est considéré comme un modèle pour la SEP humaine et aussi pour l'étude des maladies et complications induites par les Morbillivirus en général (3). Dans notre laboratoire, nous avons utilisé la souche A75/17-CDV, qui est considérée comme le modèle des souches neurovirulentes de CDV. Nous avons cherché en premier lieu à établir un système robuste pour infecter des cultures neuronales avec le CDV. Nous avons choisi les cultures primaires de l'hippocampe du nouveau-né de rat (4), que nous avons ensuite infecté avec une version modifiée du A75/17, appelée rgA75/17-V (5). Dans ces cultures, nous avons prouvé que le CDV infecte des neurones et des astrocytes. Malgré une infection qui se diffuse lentement entre les cellules, cette infection cause une mort massive aussi bien des neurones infectés que non infectés. En parallèle, les astrocytes perdent leur morphologie de type étoilé pour un type polygonal. Finalment, nous avons trouvé une augmentation importante de la concentration en glutamate dans le milieu de culture, qui laisse présumer une sécrétion de glutamate par les cultures infectées (6). Nous avons ensuite étudié le mécanisme des effets cytopathiques induits par le CDV. Nous avons d'abord démontré que les glycoprotéines de surface F et H du CDV s'accumulent massivement dans le réticulum endoplasmique (RE). Cette accumulation déclenche un stress du RE, qui est caractérisé par une forte expression du facteur de transcription proapoptotique CHOP/GADD 153 et de le la calreticuline (CRT). La CRT est une protéine chaperonne localisée dans le RE et impliquée dans l'homéostasie du calcium (Ca2+) et dans le repliement des protéines. En transfectant des cellules de Vero avec des plasmides codant pour plusieurs mutants de la glycoprotéine F de CDV, nous avons démontré une corrélation entre l'accumulation des protéines virales dans le RE et l'augmentation de l'expression de CRT, le stress du RE et la perte de l'homéostasie du Ca2+. Nous avons obtenu des résultats semblables avec des cultures de cellules primaires de cerveau de rat. Ces résultats suggèrent que la CRT joue un rôle crucial dans les phénomènes neurodégénératifs pendant l'infection du SNC, notamment par le relazgage du glutamate via le Ca2+. De manière intéressante, nous démontrons également que l'infection de CDV induit une fragmentation atypique de la CRT. Cette fragmentation induit une re-localisation et une exposition sélective de fragments amino-terminaux de la CRT, connus pour êtres fortement immunogènes à la surface des cellules infectées et non infectées. A partir de ce résultat et des résultats précédents, nous proposons le mécanisme suivant: après l'infection par le CDV, la rétention dans le RE des protéines F et H provoque un stress du RE et une perte de l'homéostasie du Ca2+. Ceci induit la libération du glutamate, qui cause une dégénération rapide du SNC (sur plusieurs jours ou semaines) correspondant à la phase aiguë de la maladie chez le chien. En revanche, les fragments amino-terminaux de la CRT libérés à la surface des cellules infectées peuvent avoir un rôle important dans l'établissement d'une démyélinisation d'origine immunogène, typique de la phase chronique de l'infection de CDV. Summary : The dog pathogen canine distemper virus (CDV), closely related to the human pathogen measles virus (MV), belongs to the Morbillivirus genus of the Paramyxoviridae family. Both CDV and NIV induce complications in the central nervous system (CNS). In the acute early stage of the infection in CNS, the CDV infection induces demyelination. This stage is sometimes followed by a late persistent stage of infection with a progression of the demyelinating lesions (1). The acute early stage occurs around three weeks after the infection and demyelinating processes are associated with active virus replication and are not associated to inflammation (1). In contrast during late persistent stage, the demyelination plaque progression seems to be mainly due to an immunopathological process (2), which characteristics are shared in many aspects with the human disease multiple sclerosis (MS). For these reasons, CDV is considered as a model for human multiple sclerosis, as well as for the study of Morbillivirus-mediated pathogenesis (3). In our laboratory, we used the A75/17-CDV strain that is considered to be the prototype of neurovirulent CDV strain. We first sought to establish a well characterized and robust model for CDV infection of a neuronal culture. We chose primary cultures from newborn rat hippocampes (4) that we infected with a modified version of A75/17, called rgA75/17-V (5). In these cultures, we showed that CDV infects both neurons and astrocytes. While the infection spreads only slowly to neighbouring cells, it causes a massive death of neurons, which includes also non-infected neurons. In parallel, astrocytes undergo morphological changes from the stellate type to the polygonal type. The pharmacological blocking of the glutamate receptors revealed an implication of glutamatergic signalling in the virus-mediated cytopathic effect. Finally, we found a drastic increase concentration of glutamate in the culture medium, suggesting that glutamate was released from the cultured cells (6). We further studied the mechanism of the CDV-induced cytopathic effects. We first demonstrated that the CDV surface glycoprotein F and H markedly accumulate in the endoplasmic reticulum (ER). This accumulation triggers an ER stress, which is characterized by increased expression of the proapoptotic transcription factor CHOP/GADD 153 and calreticulin (CRT). CRT is an ER resident chaperon involved in the Ca2+ homeostasis and in the response to misfolded proteins. Transfections of Vero cells with plasmids encoding various CDV glycoprotein mutants reveal a correlation between accumulation of viral proteins in the ER, CRT overexpression, ER stress and alteration of ER Ca2+ homeostasis. Importantly, similar results are also obtained in primary cell cultures from rat brain. These results suggest that CRT plays a crucial role in CNS infection, particularly due to CRT involvement in Ca2+ mediated glutamate releases, and subsequent neurodegenerative disorders. Very intriguingly, we also demonstrated that CDV infection induces an atypical CRT fragmentation, with relocalisation and selective exposure of the highly immunogenic CRT N-terminal fragments at the surface of infected and neighbouring non-infected cells. Altogether our results combined with previous findings suggest the following scenario. After CDV infection, F and H retention alter Ca2+ homeostasis, and induce glutamate release, which in turn causes rapid CNS degeneration (within days or a week) corresponding to the acute phase of the disease in dogs. In contrast, the CRT N-terminal fragments released at the surface of infected cells may rather have an important role in the establishment of the autoimmune demyelination in the late stage of CDV infection.