Microvascular pathology in late-life depression.

Since the era of Gaupp who introduced the concept of atheroscletic depressive disorder, the concept of late-life depression has been correlated with cerebrovascular comorbidities, microvascular lesions, frontal cortical and subcortical gray and white matter hyperintensities. The predominant neuropsychological deficits concern the domains of planning, organization and abstraction, with executive dysfunction being the predominant finding. MRI studies reveal a higher prevalence of white matter lesions in elderly patients with depression. Molecular mechanisms underlying the disease still remain unclear. Hyperhomocysteinemia has been associated with depression through its toxicity to neurons and blood vessels. Endothelial dysfunction is another possible mechanism referring to the loss of vasodilatation capacity. Inflammatory phenomena, such as increased peripheral leucocytes, elevated CRP and cytokine levels, could play a role in endothelial dysfunction. In this review we will briefly combine findings from neurobiological, epidemiological, structural and post-mortem data. A more complex model in late-life depression combining different modalities could be an elucidating approach to the disease's etiopathogeny in the future.

Veterinary vaccines against Toxoplasma gondii

Toxoplasma gondii has a very wide intermediate host range and is thought to be able to infect all warm blooded animals. The parasite causes a spectrum of different diseases and clinical symptoms within the intermediate hosts and following infection most animals develop adaptive humoral and cell-mediated immune responses. The development of protective immunity to T. gondii following natural infection in many host species has led researchers to look at vaccination as a strategy to control disease, parasite multiplication and establishment in animal hosts. A range of different veterinary vaccines are required to help control T. gondii infection which include vaccines to prevent congenital toxoplasmosis, reduce or eliminate tissue cysts in meat producing animals and to prevent oocyst shedding in cats. In this paper we will discuss some of the history, challenges and progress in the development of veterinary vaccines against T. gondii.

Visuo-motor and cognitive procedural learning in children with basal ganglia pathology.

We investigated procedural learning in 18 children with basal ganglia (BG) lesions or dysfunctions of various aetiologies, using a visuo-motor learning test, the Serial Reaction Time (SRT) task, and a cognitive learning test, the Probabilistic Classification Learning (PCL) task. We compared patients with early (<1 year old, n=9), later onset (>6 years old, n=7) or progressive disorder (idiopathic dystonia, n=2). All patients showed deficits in both visuo-motor and cognitive domains, except those with idiopathic dystonia, who displayed preserved classification learning skills. Impairments seem to be independent from the age of onset of pathology. As far as we know, this study is the first to investigate motor and cognitive procedural learning in children with BG damage. Procedural impairments were documented whatever the aetiology of the BG damage/dysfunction and time of pathology onset, thus supporting the claim of very early skill learning development and lack of plasticity in case of damage.

CA88, a nuclear repetitive DNA sequence identified in Schistosoma mansoni, aids in the genotyping of nine Schistosoma species of medical and veterinary importance

CA88 is the first long nuclear repetitive DNA sequence identified in the blood fluke, Schistosoma mansoni. The assembled S. mansoni sequence, which contains the CA88 repeat, has 8,887 nucleotides and at least three repeat units of approximately 360 bp. In addition, CA88 also possesses an internal CA microsatellite, identified as SmBr18. Both PCR and BLAST analysis have been used to analyse and confirm the CA88 sequence in other S. mansoni sequences in the public database. PCR-acquired nuclear repetitive DNA sequence profiles from nine Schistosoma species were used to classify this organism into four genotypes. Included among the nine species analysed were five sequences of both African and Asian lineages that are known to infect humans. Within these genotypes, three of them refer to recognised species groups. A panel of four microsatellite loci, including SmBr18 and three previously published loci, has been used to characterise the nine Schistosoma species. Each species has been identified and classified based on its CA88 DNA fingerprint profile. Furthermore, microsatellite sequences and intra-specific variation have also been observed within the nine Schistosoma species sequences. Taken together, these results support the use of these markers in studying the population dynamics of Schistosoma isolates from endemic areas and also provide new methods for investigating the relationships between different populations of parasites. In addition, these data also indicate that Schistosoma magrebowiei is not a sister taxon to Schistosoma mattheei, prompting a new designation to a basal clade.

Myxidium volitans sp. nov., a parasite of the gallbladder of the fish, Dactylopterus volitans (Teleostei: Triglidae) from the Brazilian Atlantic coast: morphology and pathology

Myxidium volitans sp. nov. (Myxozoa: Myxidiidae) parasitizing the hypertrophied green-brownish gallbladder of the teleost Dactylopterus volitans, collected in the Atlantic coast near Niterói, Brazil was described based on ultrastructural studies. The spores were fusiform, sometimes slightly crescent-shaped on average 21.7 ± 0.3 µm (mean ± standard deviation) (n = 50) long and 5.6 ± 0.4 µm (n = 30) wide. The spore wall was thin and smooth, comprising two equally-sized valves joined by a hardly visible sutural ridge. Spores containing two pyriform polar capsules (PC) (5.0 ± 0.4 × 2.3 ± 0.3 µm) (n = 30) are situated in each extremity of the spore. The PC wall was composed of hyaline layer (0.20-0.29 µm thick) and by a thin external granular layer. Each PC contains a polar filament (PF) with irregular arrangements that was projected from its apical region to the bases of PC and coiled laterally from bases to the tip of PC. Some regular striations and S-like structures in the periphery of the PFs with four-five irregular sections were observed. Based on the spore morphology, ultrastructural differences and the specificity of the host we describe this parasite as a new myxosporidian, named M. volitans sp. nov.

Neuropathologie et pathologie moléculaire des gliomes [Neuropathology and molecular pathology of gliomas]

Gliomas are the most frequent primary brain tumours. The WHO classification is essentially based on histological and immunohistochemical criteria. More recently multiple cytogenetic and molecular alterations associated with initiation and progression have been shown and the genetic profiles of tumour entities have been incorporated in the WHO classifiacation. Molecular testing of the MGMT promotor methylation in glioblastoma, predictive for the response to combined radio-/chimiothérapie, and the LOH 1p/19q in oligodendroglial tumours, as prognostic factor supplements the histopathological diagnosis. In the near futur array-based profiling techniques will contribute to a refinement of glioma classification and identify targets for more individualized glioma therapies.

Unison or cacophony: postgraduate training in pathology in Europe.

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.

Pathology of peripheral T-cell lymphomas: where do we stand?

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.

Correlation of intra- and extraepidermal CD8 T cell numbers with development of psoriatic epidermal pathology

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.

New validated prognostic models and prognostic calculators in patients with low-grade gliomas diagnosed by central pathology review: a pooled analysis of EORTC/RTOG/NCCTG phase III clinical trials.

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.

Acute aortic dissection with carotid and coronary malperfusion: from imaging to pathology.

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.