Microtubule-associated protein-2 immunoreactivity: a useful tool in the differential diagnosis of low-grade neuroepithelial tumors.

Complex and variable morphological phenotypes pose a major challenge to the histopathological classification of neuroepithelial tumors. This applies in particular for low-grade gliomas and glio-neuronal tumors. Recently, we and others have identified microtubule-associated protein-2 (MAP2) as an immunohistochemical marker expressed in the majority of glial tumors. Characteristic cell morphologies can be recognized by MAP2 immunoreactivity in different glioma entities, i.e., process sparse oligodendroglial versus densely ramified astrocytic elements. Here, we describe MAP2-immunoreactivity patterns in a large series of various neuroepithelial tumors and related neoplasms (n = 960). Immunohistochemical analysis led to the following conclusions: (1) specific pattern of MAP2-positive tumor cells can be identified in 95% of glial neoplasms; (2) ependymal tumors do not express MAP2 in their rosette-forming cell component; (3) tumors of the pineal gland as well as malignant embryonic tumors are also characterized by abundant MAP2 immunoreactivity; (4) virtually no MAP2 expression can be observed in the neoplastic glial component of glio-neuronal tumors, i.e. gangliogliomas; (5) malignant glial tumor variants (WHO grade III or IV) exhibit different and less specific MAP2 staining patterns compared to their benign counterparts (WHO grade I or II); (6) with the exception of melanomas and small cell lung cancers, MAP2 expression is very rare in metastatic and non-neuroepithelial tumors; (7) glial MAP2 expression was not detected in 56 non-neoplastic lesions. These data point towards MAP2 as valuable diagnostic tool for pattern recognition and differential diagnosis of low-grade neuroepithelial tumors.

Role of double-balloon enteroscopy in malignant small bowel tumors.

AIMTo assess the double-balloon enteroscopy (DBE) role in malignant small bowel tumors (MSBT). METHODS This is a retrospective descriptive study performed in a single center. All consecutive patients who underwent a DBE with final diagnosis of a malignant neoplasm from 2004 to 2014 in our referral center were included. Patient demographic and clinical pathological characteristics were recorded and reviewed. MSBT diagnosis was achieved either by DBE directed biopsy with multiple tissue sampling, endoscopic findings or histological analysis of surgical specimen. We have analyzed double-balloon enteroscopy impact in outcome and clinical course of these patients. RESULTS Of 627 patients, 28 (4.5%) (mean age = 60 ± 17.3 years) underwent 30 procedures (25 anterograde, 5 retrograde) and were diagnosed of a malignant tumor. Patients presented with obscure gastrointestinal bleeding (n = 19, 67.9%), occlusion syndrome (n = 7, 25%) and diarrhea (n = 1, 3.6%). They were diagnosed by DBE biopsy (n = 18, 64.3%), histological analysis of surgical specimen (n = 7, 25%) and unequivocal endoscopic findings (n = 2, 7.1%). Gastrointestinal stromal tumor (n = 8, 28.6%), adenocarcinoma (n = 7, 25%), lymphoma (n = 4, 14.3%), neuroendocrine tumor (n = 4, 14.3%), metastatic (n = 3, 10.7%) and Kaposi sarcoma (n = 1, 3.6%) were identified. DBE modified outcome in 7 cases (25%), delaying or avoiding emergency surgery (n = 3), modifying surgery approach (n = 2) and indicating emergency SB partial resection instead of elective approach (n = 2). CONCLUSION DBE may be critical in the management of MSBT providing additional information that may be decisive in the clinical course of these patients.

Synthesis of bone-like structured foams

Here we present a processing route to produce multi-structured ceramic foams based on the combination of particle-stabilized foams with polymeric sponges to produce positive and negative templating structures. Polyester sponges are infiltrated with freshly produced calcium aluminate alumina foams and upon sintering either positive templating structures are produced when wetting the sponges, or negative templating foams with a percolating pore network are obtained when completely filling the sponges. Additionally, by combining different layers of these particle-stabilized foam infiltrated sponges, various different structures can be produced, including sandwich structures, pore size gradients, and ceramic bone-like structures applying to different types of bone. The particle-stabilized foams used were in situ self-hardening calcium aluminate cement enriched alumina foams to obtain crack-free samples with pore interconnections and tailorable pore sizes.

Multifocal epithelial tumors and field cancerization: stroma as a primary determinant.

It is increasingly evident that cancer results from altered organ homeostasis rather than from deregulated control of single cells or groups of cells. This applies especially to epithelial cancer, the most common form of human solid tumors and a major cause of cancer lethality. In the vast majority of cases, in situ epithelial cancer lesions do not progress into malignancy, even if they harbor many of the genetic changes found in invasive and metastatic tumors. While changes in tumor stroma are frequently viewed as secondary to changes in the epithelium, recent evidence indicates that they can play a primary role in both cancer progression and initiation. These processes may explain the phenomenon of field cancerization, i.e., the occurrence of multifocal and recurrent epithelial tumors that are preceded by and associated with widespread changes of surrounding tissue or organ "fields."

Delta-like 4 is the essential, nonredundant ligand for Notch1 during thymic T cell lineage commitment.

Thymic T cell lineage commitment is dependent on Notch1 (N1) receptor-mediated signaling. Although the physiological ligands that interact with N1 expressed on thymic precursors are currently unknown, in vitro culture systems point to Delta-like 1 (DL1) and DL4 as prime candidates. Using DL1- and DL4-lacZ reporter knock-in mice and novel monoclonal antibodies to DL1 and DL4, we show that DL4 is expressed on thymic epithelial cells (TECs), whereas DL1 is not detected. The function of DL4 was further explored in vivo by generating mice in which DL4 could be specifically inactivated in TECs or in hematopoietic progenitors. Although loss of DL4 in hematopoietic progenitors did not perturb thymus development, inactivation of DL4 in TECs led to a complete block in T cell development coupled with the ectopic appearance of immature B cells in the thymus. These immature B cells were phenotypically indistinguishable from those developing in the thymus of conditional N1 mutant mice. Collectively, our results demonstrate that DL4 is the essential and nonredundant N1 ligand responsible for T cell lineage commitment. Moreover, they strongly suggest that N1-expressing thymic progenitors interact with DL4-expressing TECs to suppress B lineage potential and to induce the first steps of intrathymic T cell development.

Circulating insulin-like growth factor-I in pregnancy and maternal risk of breast cancer.

BACKGROUND: Elevated serum concentrations of insulin-like growth factor (IGF)-1 have been associated with increased risk of breast cancer. Previously, we reported a similar association in samples obtained during pregnancy. The current study was conducted to further characterize the association of IGF-1 during pregnancy with maternal breast cancer risk. METHODS: A case-control study was nested within the Finnish Maternity Cohort. The study was limited to primiparous women less than 40 years of age, who donated blood samples during early (median, 12 weeks) pregnancy and delivered a single child at term. Seven hundred and nineteen women with invasive breast cancer were eligible. Two controls (n = 1,434) were matched to each case on age and date at blood donation. Serum IGF-1 concentration was measured using an Immulite 2000 analyzer. Conditional logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (CI).RESULTS: No significant associations were observed between serum IGF-1 concentrations and breast cancer risk in both the overall analysis (OR 1.08 (95% CI 0.80-1.47) and in analyses stratified by histological subtype, lag-time to cancer diagnosis, age at pregnancy or age at diagnosis.CONCLUSIONS: There was no association between IGF-1 and maternal breast cancer risk during early pregnancy in this large nested case-control study.Impact:Serum IGF-1 concentrations during early pregnancy may not be related to maternal risk of breast cancer.

REST Regulates Oncogenic Properties of Glioblastoma Stem Cells.

Glioblastoma multiforme (GBM) tumors are the most common malignant primary brain tumors in adults. Although many GBM tumors are believed to be caused by self-renewing, glioblastoma-derived stem-like cells (GSCs), the mechanisms that regulate self-renewal and other oncogenic properties of GSCs are only now being unraveled. Here we showed that GSCs derived from GBM patient specimens express varying levels of the transcriptional repressor repressor element 1 silencing transcription factor (REST), suggesting heterogeneity across different GSC lines. Loss- and gain-of-function experiments indicated that REST maintains self-renewal of GSCs. High REST-expressing GSCs (HR-GSCs) produced tumors histopathologically distinct from those generated by low REST-expressing GSCs (LR-GSCs) in orthotopic mouse brain tumor models. Knockdown of REST in HR-GSCs resulted in increased survival in GSC-transplanted mice and produced tumors with higher apoptotic and lower invasive properties. Conversely, forced expression of exogenous REST in LR-GSCs produced decreased survival in mice and produced tumors with lower apoptotic and higher invasive properties, similar to HR-GSCs. Thus, based on our results, we propose that a novel function of REST is to maintain self-renewal and other oncogenic properties of GSCs and that REST can play a major role in mediating tumorigenicity in GBM. STEM CELLS 2012;30:405-414.

Intérêt de l'angiographie numérisée au vert d'indocyanine dans le diagnostic différentiel des tumeurs non pigmentées de la choroïde [Value of indocyanine green videoangiography in differential diagnosis of nonpigmented tumors of the choroid]

BACKGROUND: Indocyanine green video-angiography (ICG) is a recent examination technique, its possibilities and limitations as far as intraocular tumours are concerned, haven't been fully explored yet. MATERIAL AND METHODS: We have studied 50 cases of non-pigmented choroidal tumours, including 14 cases of choroidal hemangioma's, 11 cases of posterior uveal metastases and 25 cases of non-pigmented melanoma's. RESULTS: Characteristic images were obtained when examining choroidal hemangioma's and, until a certain point, posterior choroidal metastases. Non pigmented melanoma's on the contrary, presented a great variety of different indocyanine green angiographic pictures. CONCLUSION: Indocyanine green video-angiography (ICG) has a definite value in the differential diagnosis of non-pigmented posterior choroidal tumours.

Disease in the dark: molecular characterization of Polychromophilus murinus in temperate zone bats revealed a worldwide distribution of this malaria-like disease.

For a better understanding of the complex coevolutionary processes between hosts and parasites, accurate identification of the actors involved in the interaction is of fundamental importance. Blood parasites of the Order Haemosporidia, responsible for malaria, have become the focus of a broad range of studies in evolutionary biology. Interestingly, molecular-based studies on avian malaria have revealed much higher species diversity than previously inferred with morphology. Meanwhile, studies on bat haemosporidian have been largely neglected. In Europe, only one genus (Polychromophilus) and two species have been morphologically described. To evaluate the presence of potential cryptic species and parasite prevalence, we undertook a molecular characterization of Polychromophilus in temperate zone bats. We used a nested-PCR approach on the cytochrome b mitochondrial gene to detect the presence of parasites in 237 bats belonging to four different species and in the dipteran bat fly Nycteribia kolenatii, previously described as being the vector of Polychromophilus. Polychromophilus murinus was found in the four bat species and in the insect vector with prevalence ranging from 4% for Myotis myotis to 51% for M. daubentoni. By sequencing 682 bp, we then investigated the phylogenetic relationships of Polychromophilus to other published malarial lineages. Seven haplotypes were found, all very closely related, suggesting the presence of a single species in our samples. These haplotypes formed a well-defined clade together with Haemosporidia of tropical bats, revealing a worldwide distribution of this parasite mostly neglected by malarial studies since the 1980s.

Virological and Immunological Characterization of Novel NYVAC-Based HIV/AIDS Vaccine Candidates Expressing Clade C Trimeric Soluble gp140(ZM96) and Gag(ZM96)-Pol-Nef(CN54) as Virus-Like Particles.

The generation of vaccines against HIV/AIDS able to induce long-lasting protective immunity remains a major goal in the HIV field. The modest efficacy (31.2%) against HIV infection observed in the RV144 phase III clinical trial highlighted the need for further improvement of HIV vaccine candidates, formulation, and vaccine regimen. In this study, we have generated two novel NYVAC vectors, expressing HIV-1 clade C gp140(ZM96) (NYVAC-gp140) or Gag(ZM96)-Pol-Nef(CN54) (NYVAC-Gag-Pol-Nef), and defined their virological and immunological characteristics in cultured cells and in mice. The insertion of HIV genes does not affect the replication capacity of NYVAC recombinants in primary chicken embryo fibroblast cells, HIV sequences remain stable after multiple passages, and HIV antigens are correctly expressed and released from cells, with Env as a trimer (NYVAC-gp140), while in NYVAC-Gag-Pol-Nef-infected cells Gag-induced virus-like particles (VLPs) are abundant. Electron microscopy revealed that VLPs accumulated with time at the cell surface, with no interference with NYVAC morphogenesis. Both vectors trigger specific innate responses in human cells and show an attenuation profile in immunocompromised adult BALB/c and newborn CD1 mice after intracranial inoculation. Analysis of the immune responses elicited in mice after homologous NYVAC prime/NYVAC boost immunization shows that recombinant viruses induced polyfunctional Env-specific CD4 or Gag-specific CD8 T cell responses. Antibody responses against gp140 and p17/p24 were elicited. Our findings showed important insights into virus-host cell interactions of NYVAC vectors expressing HIV antigens, with the activation of specific immune parameters which will help to unravel potential correlates of protection against HIV in human clinical trials with these vectors. IMPORTANCE: We have generated two novel NYVAC-based HIV vaccine candidates expressing HIV-1 clade C trimeric soluble gp140 (ZM96) and Gag(ZM96)-Pol-Nef(CN54) as VLPs. These vectors are stable and express high levels of both HIV-1 antigens. Gag-induced VLPs do not interfere with NYVAC morphogenesis, are highly attenuated in immunocompromised and newborn mice after intracranial inoculation, trigger specific innate immune responses in human cells, and activate T (Env-specific CD4 and Gag-specific CD8) and B cell immune responses to the HIV antigens, leading to high antibody titers against gp140. For these reasons, these vectors can be considered vaccine candidates against HIV/AIDS and currently are being tested in macaques and humans.

Comparative analysis of the roles of HtrA-like surface proteases in two virulent Staphylococcus aureus strains.

The HtrA surface protease is involved in the virulence of many pathogens, mainly by its role in stress resistance and bacterial survival. Staphylococcus aureus encodes two putative HtrA-like proteases, referred to as HtrA(1) and HtrA(2). To investigate the roles of HtrA proteins in S. aureus, we constructed htrA(1), htrA(2), and htrA(1) htrA(2) insertion mutants in two genetically different virulent strains, RN6390 and COL. In the RN6390 context, htrA(1) inactivation resulted in sensitivity to puromycin-induced stress. The RN6390 htrA(1) htrA(2) mutant was affected in the expression of several secreted virulence factors comprising the agr regulon. This observation was correlated with the disappearance of the agr RNA III transcript in the RN6390 htrA(1) htrA(2) mutant. The virulence of this mutant was diminished in a rat model of endocarditis. In the COL context, both HtrA(1) and HtrA(2) were essential for thermal stress survival. However, only HtrA(1) had a slight effect on exoprotein expression. The htrA mutations did not diminish the virulence of the COL strain in the rat model of endocarditis. Our results indicate that HtrA proteins have different roles in S. aureus according to the strain, probably depending on specific differences in the regulation of virulence factor and stress protein expression. We propose that HtrA(1) and HtrA(2) contribute to pathogenicity by controlling the production of certain extracellular factors that are crucial for bacterial dissemination, as revealed in the RN6390 background. We speculate that HtrA proteins act in the agr-dependent regulation pathway by assuring folding and/or maturation of some surface components of the agr system.

Biliverdin inhibits Toll-like receptor-4 (TLR4) expression through nitric oxide-dependent nuclear translocation of biliverdin reductase.

The cellular response to an inflammatory stressor requires a proinflammatory cellular activation followed by a controlled resolution of the response to restore homeostasis. We hypothesized that biliverdin reductase (BVR) by binding biliverdin (BV) quells the cellular response to endotoxin-induced inflammation through phosphorylation of endothelial nitric oxide synthase (eNOS). The generated NO, in turn, nitrosylates BVR, leading to nuclear translocation where BVR binds to the Toll-like receptor-4 (TLR4) promoter at the Ap-1 sites to block transcription. We show in macrophages that BV-induced eNOS phosphorylation (Ser-1177) and NO production are mediated in part by Ca(2+)/calmodulin-dependent kinase kinase. Furthermore, we show that BVR is S-nitrosylated on one of three cysteines and that this posttranslational modification is required for BVR-mediated signaling. BV-induced nuclear translocation of BVR and inhibition of TLR4 expression is lost in macrophages derived from Enos(-/-) mice. In vivo in mice, BV provides protection from acute liver damage and is dependent on the availability of NO. Collectively, we elucidate a mechanism for BVR in regulating the inflammatory response to endotoxin that requires eNOS-derived NO and TLR4 signaling in macrophages.