Rapid spontaneous malignant progression of supratentorial tanycytic ependymoma with sarcomatous features - "Ependymosarcoma"

By analogy to gliosarcoma, the term "ependymosarcoma" has recently been coined to thematize the rare phenomenon of a malignant mesenchymal component arising within an ependymoma. We report on an example of this paradigm, involving tanycytic ependymoma as the host tumor in a 40-year-old female who underwent two tumor extirpation procedures at one-year interval. She first presented with severe headaches, and was seen by imaging to harbor a moderately enhancing mass 2.5cm in diameter at the rostral septum pellucidum accompanied by occlusive hydrocephalus. Microscopically, the tumor consisted of solid, wavy fascicles of elongated cells that were occasionally interrupted by vague perivascular pseudorosettes. Mitotic activity was absent, and less than 1% of nuclei immunoreacted for MIB-1. A histological diagnosis of tanycytic ependymoma (WHO grade II) was rendered, and no adjuvant therapy given. At recurrence, the lesion was 3.5cm in diameter, intensely enhancing, and had already seeded into the subarachnoid space. Histology showed a biphasic glial-sarcomatous architecture with remnants of the original ependymoma now displaying hypercellularity and atypical - yet not frankly anaplastic - features. The sarcomatous moiety consisted of spindle and epithelioid cells densely interwoven with reticulin fibers. While the ependymal component was GFAP and S100 protein positive, and featured punctate staining for EMA, none of these markers was expressed in the adjacent sarcoma. Instead, the latter reacted for vimentin and smooth muscle actin. To the best of our knowledge, this is the first documentation of tanycytic ependymoma undergoing malignant transformation, one driven by a highly anaplastic mesenchymal component, corresponding to "ependymosarcoma".

Mesh-based vs. Image-based Statistical Appearance Model of the Human Femur: a Preliminary Comparison Study for the Creation of Finite Element Meshes

Statistical models have been recently introduced in computational orthopaedics to investigate the bone mechanical properties across several populations. A fundamental aspect for the construction of statistical models concerns the establishment of accurate anatomical correspondences among the objects of the training dataset. Various methods have been proposed to solve this problem such as mesh morphing or image registration algorithms. The objective of this study is to compare a mesh-based and an image-based statistical appearance model approaches for the creation of nite element(FE) meshes. A computer tomography (CT) dataset of 157 human left femurs was used for the comparison. For each approach, 30 finite element meshes were generated with the models. The quality of the obtained FE meshes was evaluated in terms of volume, size and shape of the elements. Results showed that the quality of the meshes obtained with the image-based approach was higher than the quality of the mesh-based approach. Future studies are required to evaluate the impact of this finding on the final mechanical simulations.

Prognostic relevance of Bcl-2 overexpression in surgically treated prostate cancer is not caused by increased copy number or translocation of the gene

Overexpression of anti-apoptotic Bcl-2 plays a role in prostate cancer progression, particularly in transformation to androgen-independent disease. Androgen-independent prostate cancers have been shown to harbor Bcl-2 gene copy number gains frequently suggesting that this genetic alteration might play a role in Bcl-2 overexpression. The relation of Bcl-2 overexpression and copy number gains or translocation of the BCL-2 gene in prostate cancer under hormone-naïve conditions is unknown.

Demonstration of epitope-spreading phenomena in bullous pemphigoid: results of a prospective multicenter study

Bullous pemphigoid (BP), the most common autoimmune subepidermal bullous disease, is associated with an autoantibody response to BP180 and BP230, two components of junctional adhesion complexes in human skin promoting dermo-epidermal cohesion. Retrospective analyses demonstrated that these autoantigens harbor several epitopes targeted by autoaggressive B and T cells. The aim of this prospective multicenter study was to assess the evolution of IgG autoantibodies in 35 BP patients over a 12-month observation period. Epitope-spreading (ES) events were detected in 17 of 35 BP patients (49%). They preferentially occurred in an early stage of the disease and were significantly related to disease severity at diagnosis. Moreover, in three patients, spreading of IgG reactivity to intracellular epitopes of BP180 and BP230 was preceded by recognition of the BP180 ectodomain. Finally, IgG reactivity with extracellular epitopes of BP180 and intracellular epitopes of BP230 correlated with the severity of BP in disease course. These findings support the idea that IgG recognition of the BP180 ectodomain is an early and crucial event in BP disease, followed by variable intra- and intermolecular ES events, which likely shape the individual course of BP.

HIV-1-related Hodgkin lymphoma in the era of combination antiretroviral therapy: incidence and evolution of CD4⁺ T-cell lymphocytes

The risk of Hodgkin lymphoma (HL) is increased in patients infected with HIV-1. We studied the incidence and outcomes of HL, and compared CD4⁺ T-cell trajectories in HL patients and controls matched for duration of combination antiretroviral therapy (cART). A total of 40 168 adult HIV-1-infected patients (median age, 36 years; 70% male; median CD4 cell count, 234 cells/μL) from 16 European cohorts were observed during 159 133 person-years; 78 patients developed HL. The incidence was 49.0 (95% confidence interval [CI], 39.3-61.2) per 100,000 person-years, and similar on cART and not on cART (P = .96). The risk of HL declined as the most recent (time-updated) CD4 count increased: the adjusted hazard ratio comparing more than 350 with less than 50 cells/μL was 0.27 (95% CI, 0.08-0.86). Sixty-one HL cases diagnosed on cART were matched to 1652 controls: during the year before diagnosis, cases lost 98 CD4 cells (95% CI, -159 to -36 cells), whereas controls gained 35 cells (95% CI, 24-46 cells; P < .0001). The incidence of HL is not reduced by cART, and patients whose CD4 cell counts decline despite suppression of HIV-1 replication on cART may harbor HL.

Intestinal bacterial colonization induces mutualistic regulatory T cell responses

Mammals harbor a dense commensal microbiota in the colon. Regulatory T (Treg) cells are known to limit microbe-triggered intestinal inflammation and the CD4+ T cell compartment is shaped by the presence of particular microbes or bacterial compounds. It is, however, difficult to distinguish whether these effects reflect true mutualistic immune adaptation to intestinal colonization or rather idiosyncratic immune responses. To investigate truly mutualistic CD4+ T cell adaptation, we used the altered Schaedler flora (ASF). Intestinal colonization resulted in activation and de novo generation of colonic Treg cells. Failure to activate Treg cells resulted in the induction of T helper 17 (Th17) and Th1 cell responses, which was reversed by wild-type Treg cells. Efficient Treg cell induction was also required to maintain intestinal homeostasis upon dextran sulfate sodium-mediated damage in the colon. Thus, microbiota colonization-induced Treg cell responses are a fundamental intrinsic mechanism to induce and maintain host-intestinal microbial T cell mutualism.

Development and validation of a real-time quantitative PCR assay for rapid identification of Bacillus anthracis in environmental samples

A real-time polymerase chain reaction (PCR) assay was developed for rapid identification of Bacillus anthracis in environmental samples. These samples often harbor Bacillus cereus bacteria closely related to B. anthracis, which may hinder its specific identification by resulting in false positive signals. The assay consists of two duplex real-time PCR: the first PCR allows amplification of a sequence specific of the B. cereus group (B. anthracis, B. cereus, Bacillus thuringiensis, Bacillus weihenstephanensis, Bacillus pseudomycoides, and Bacillus mycoides) within the phosphoenolpyruvate/sugar phosphotransferase system I gene and a B. anthracis specific single nucleotide polymorphism within the adenylosuccinate synthetase gene. The second real-time PCR assay targets the lethal factor gene from virulence plasmid pXO1 and the capsule synthesis gene from virulence plasmid pXO2. Specificity of the assay is enhanced by the use of minor groove binding probes and/or locked nucleic acids probes. The assay was validated on 304 bacterial strains including 37 B. anthracis, 67 B. cereus group, 54 strains of non-cereus group Bacillus, and 146 Gram-positive and Gram-negative bacteria strains. The assay was performed on various environmental samples spiked with B. anthracis or B. cereus spores. The assay allowed an accurate identification of B. anthracis in environmental samples. This study provides a rapid and reliable method for improving rapid identification of B. anthracis in field operational conditions.

Antibiotic resistance profile of Staphylococcus rostri, a new species isolated from healthy pigs

Staphylococcus rostri is a newly described Staphylococcus species that is present in the nasal cavity of healthy pigs. Out of the 225 pigs tested at slaughterhouse, 46.7% carried the new species alone and 22% in combination with Staphylococcus aureus. An antibiotic resistance profile was determined for S. rostri and compared to that of S. aureus isolated from the same pig. Resistance to tetracycline specified by tet(M), tet(K) and tet(L), streptomycin (str(pS194)), penicillin (blaZ), trimethoprim (dfr(G)), and erythromycin and clindamycin (erm genes), were found in both species; however, with the exception of streptomycin and trimethoprim, resistance was higher in S. aureus. S. rostri isolates display very low genetic diversity as demonstrated by pulsed-field gel electrophoresis, which generated two major clusters. Several clonal complexes (CC1, CC5, CC9, CC30 and CC398) were identified in S. aureus with CC 9 and CC 398 being the most frequent. Our study gives the first overview of the distribution, genetic relatedness, and resistance profile of one coagulase-negative Staphylococcus species that is commonly present in the nares of healthy pigs in Switzerland, and shows that S. rostri may harbor resistance genes associated with transferable elements like Tn916.

Generation of HIV latency in humanized BLT mice

Here we demonstrate that a combination of tenofovir, emtricitabine, and raltegravir effectively suppresses peripheral and systemic HIV replication in humanized BLT mice. We also demonstrate that antiretroviral therapy (ART)-treated humanized BLT mice harbor latently infected resting human CD4+ T cells that can be induced ex vivo to produce HIV. We observed that the levels of infected resting human CD4+ T cells present in BLT mice are within the range of those observed circulating in patients undergoing suppressive ART. These results demonstrate the potential of humanized BLT mice as an attractive model for testing the in vivo efficacy of novel HIV eradication strategies.