Differential effects of GABAB receptor subtypes, {gamma}-hydroxybutyric Acid, and Baclofen on EEG activity and sleep regulation.

The role of GABA(B) receptors in sleep is still poorly understood. GHB (γ-hydroxybutyric acid) targets these receptors and is the only drug approved to treat the sleep disorder narcolepsy. GABA(B) receptors are obligate dimers comprised of the GABA(B2) subunit and either one of the two GABA(B1) subunit isoforms, GABA(B1a) and GABA(B1b). To better understand the role of GABA(B) receptors in sleep regulation, we performed electroencephalogram (EEG) recordings in mice devoid of functional GABA(B) receptors (1(-/-) and 2(-/-)) or lacking one of the subunit 1 isoforms (1a(-/-) and 1b(-/-)). The distribution of sleep over the day was profoundly altered in 1(-/-) and 2(-/-) mice, suggesting a role for GABA(B) receptors in the circadian organization of sleep. Several other sleep and EEG phenotypes pointed to a more prominent role for GABA(B1a) compared with the GABA(B1b) isoform. Moreover, we found that GABA(B1a) protects against the spontaneous seizure activity observed in 1(-/-) and 2(-/-) mice. We also evaluated the effects of the GHB-prodrug GBL (γ-butyrolactone) and of baclofen (BAC), a high-affinity GABA(B) receptor agonist. Both drugs induced a state distinct from physiological sleep that was not observed in 1(-/-) and 2(-/-) mice. Subsequent sleep was not affected by GBL whereas BAC was followed by a delayed hypersomnia even in 1(-/-) and 2(-/-) mice. The differential effects of GBL and BAC might be attributed to differences in GABA(B)-receptor affinity. These results also indicate that all GBL effects are mediated through GABA(B) receptors, although these receptors do not seem to be involved in mediating the BAC-induced hypersomnia.

Combining chromosomal arm status and significantly aberrant genomic locations reveals new cancer subtypes.

Many types of tumors exhibit characteristic chromosomal losses or gains, as well as local amplifications and deletions. Within any given tumor type, sample specific amplifications and deletions are also observed. Typically, a region that is aberrant in more tumors, or whose copy number change is stronger, would be considered as a more promising candidate to be biologically relevant to cancer. We sought for an intuitive method to define such aberrations and prioritize them. We define V, the "volume" associated with an aberration, as the product of three factors: (a) fraction of patients with the aberration, (b) the aberration's length and (c) its amplitude. Our algorithm compares the values of V derived from the real data to a null distribution obtained by permutations, and yields the statistical significance (p-value) of the measured value of V. We detected genetic locations that were significantly aberrant, and combine them with chromosomal arm status (gain/loss) to create a succinct fingerprint of the tumor genome. This genomic fingerprint is used to visualize the tumors, highlighting events that are co-occurring or mutually exclusive. We apply the method on three different public array CGH datasets of Medulloblastoma and Neuroblastoma, and demonstrate its ability to detect chromosomal regions that were known to be altered in the tested cancer types, as well as to suggest new genomic locations to be tested. We identified a potential new subtype of Medulloblastoma, which is analogous to Neuroblastoma type 1.

Structural determinants involved in the activation and regulation of G protein-coupled receptors: lessons from the alpha1-adrenegic receptor subtypes.

The aim of a large number of studies on G protein-coupled receptors was centered on understanding the structural basis of their main functional properties. Here, we will briefly review the results obtained on the alpha1-adrenergic receptor subtypes belonging to the rhodopsin-like family of receptors. These findings contribute, on the one hand, to further understand the molecular basis of adrenergic transmission and, on the other, to provide some generalities on the structure-functional relationship of G protein-coupled receptors.

Role of endothelin receptor subtypes in volume-stimulated ANF secretion.

The role of endothelin (ET) receptors was tested in volume-stimulated atrial natriuretic factor (ANF) secretion in conscious rats. Mean ANF responses to slow infusions (3 x 3.3 ml/8 min) were dose dependently reduced (P < 0.05) by bosentan (nonselective ET-receptor antagonist) from 64.1 +/- 18.1 (SE) pg/ml (control) to 52.6 +/- 16.1 (0.033 mg bosentan/rat), 16.1 +/- 7.6 (0. 33 mg/rat), and 11.6 +/- 6.5 pg/ml (3.3 mg/rat). The ET-A-receptor antagonist BQ-123 (1 mg/rat) had no effect relative to DMSO controls, whereas the putative ET-B antagonist IRL-1038 (0.1 mg/rat) abolished the response. In a second protocol, BQ-123 (>/=0.5 mg/rat) nonsignificantly reduced the peak ANF response (106.1 +/- 23.0 pg/ml) to 74.0 +/- 20.5 pg/ml for slow infusions (3.5 ml/8.5 min) but reduced the peak response (425.3 +/- 58.1 pg/ml) for fast infusions (6.6 ml/1 min) by 49.9% (P < 0.001) and for 340 pmoles ET-1 (328.8 +/- 69.5 pg/ml) by 83.5% (P < 0.0001). BQ-123 abolished the ET-1-induced increase in arterial pressure (21.8 +/- 5.2 mmHg at 1 min). Changes in central venous pressure were similar for DMSO and BQ-123 (slow: 0.91 and 1.14 mmHg; fast: 4.50 and 4.13 mmHg). The results suggest 1) ET-B receptors mainly mediate the ANF secretion to slow volume expansions of <1.6%/min; and 2) ET-A receptors mainly mediate the ANF response to acute volume overloads.

Données actualisées sur la physiopathologie, les phénotypes et les traitements de la maladie de Still de l'adulte [Pathophysiology, subtypes, and treatments of adult-onset Still's disease: An update].

Adult-onset Still's disease is a rare and difficult to diagnose multisystemic disorder considered as a multigenic autoinflammatory syndrome. Its immunopathogenesis seems to be at the crossroads between inflammasomopathies and hemophagocytic lymphohistiocytosis, the most severe manifestation of the disease. According to recent insights in the pathophysiology and thanks to cohort studies and therapeutic trials, two phenotypes of adult-onset Still's disease may be distinguished: a systemic pattern, initially highly symptomatic and with a higher risk to exhibit life-threatening complications such as reactive hemophagocytic lymphohistiocytosis, where interleukin-1 blockade seems to be very effective, a chronic articular pattern, more indolent with arthritis in the foreground and less severe systemic manifestations, which would threat functional outcome and where interleukin-6 blockade seems to be more effective. This review focuses on these data.

Tracing the associations between sex, the atypical and the combined atypical-melancholic depression subtypes: A path analysis.

BACKGROUND: Numerous studies have examined determinants leading to preponderance of women in major depressive disorder (MDD), which is particularly accentuated for the atypical depression subtype. It is thus of interest to explore the specific indirect effects influencing the association between sex and established depression subtypes. METHODS: The data of 1624 subjects with a lifetime diagnosis of MDD derived from the population-based PsyCoLaus data were used. An atypical (n=256), a melancholic (n=422), a combined atypical and melancholic features subtype (n=198), and an unspecified MDD group (n=748) were constructed according to the DSM-IV specifiers. Path models with direct and indirect effects were applied to the data. RESULTS: Partial mediation of the female-related atypical and combined atypical-melancholic depression subtypes was found. Early anxiety disorders and high emotion-orientated coping acted as mediating variables between sex and the atypical depression subtype. In contrast, high Body Mass Index (BMI) served as a suppression variable, also concerning the association between sex and the combined atypical-melancholic subtype. The latter association was additionally mediated by an early age of MDD onset and early/late anxiety disorders. LIMITATIONS: The use of cross-sectional data does not allow causal conclusions. CONCLUSIONS: This is the first study that provides evidence for a differentiation of the general mechanisms explaining sex differences of overall MDD by depression subtypes. Determinants affecting the pathways begin early in life. Since some of them are primarily of behavioral nature, the present findings could be a valuable target in mental health care.

Mir-21-Sox2 Axis Delineates Glioblastoma Subtypes with Prognostic Impact.

UNLABELLED: Glioblastoma (GBM) is the most aggressive human brain tumor. Although several molecular subtypes of GBM are recognized, a robust molecular prognostic marker has yet to be identified. Here, we report that the stemness regulator Sox2 is a new, clinically important target of microRNA-21 (miR-21) in GBM, with implications for prognosis. Using the MiR-21-Sox2 regulatory axis, approximately half of all GBM tumors present in the Cancer Genome Atlas (TCGA) and in-house patient databases can be mathematically classified into high miR-21/low Sox2 (Class A) or low miR-21/high Sox2 (Class B) subtypes. This classification reflects phenotypically and molecularly distinct characteristics and is not captured by existing classifications. Supporting the distinct nature of the subtypes, gene set enrichment analysis of the TCGA dataset predicted that Class A and Class B tumors were significantly involved in immune/inflammatory response and in chromosome organization and nervous system development, respectively. Patients with Class B tumors had longer overall survival than those with Class A tumors. Analysis of both databases indicated that the Class A/Class B classification is a better predictor of patient survival than currently used parameters. Further, manipulation of MiR-21-Sox2 levels in orthotopic mouse models supported the longer survival of the Class B subtype. The MiR-21-Sox2 association was also found in mouse neural stem cells and in the mouse brain at different developmental stages, suggesting a role in normal development. Therefore, this mechanism-based classification suggests the presence of two distinct populations of GBM patients with distinguishable phenotypic characteristics and clinical outcomes. SIGNIFICANCE STATEMENT: Molecular profiling-based classification of glioblastoma (GBM) into four subtypes has substantially increased our understanding of the biology of the disease and has pointed to the heterogeneous nature of GBM. However, this classification is not mechanism based and its prognostic value is limited. Here, we identify a new mechanism in GBM (the miR-21-Sox2 axis) that can classify ∼50% of patients into two subtypes with distinct molecular, radiological, and pathological characteristics. Importantly, this classification can predict patient survival better than the currently used parameters. Further, analysis of the miR-21-Sox2 relationship in mouse neural stem cells and in the mouse brain at different developmental stages indicates that miR-21 and Sox2 are predominantly expressed in mutually exclusive patterns, suggesting a role in normal neural development.

The consensus molecular subtypes of colorectal cancer.

Colorectal cancer (CRC) is a frequently lethal disease with heterogeneous outcomes and drug responses. To resolve inconsistencies among the reported gene expression-based CRC classifications and facilitate clinical translation, we formed an international consortium dedicated to large-scale data sharing and analytics across expert groups. We show marked interconnectivity between six independent classification systems coalescing into four consensus molecular subtypes (CMSs) with distinguishing features: CMS1 (microsatellite instability immune, 14%), hypermutated, microsatellite unstable and strong immune activation; CMS2 (canonical, 37%), epithelial, marked WNT and MYC signaling activation; CMS3 (metabolic, 13%), epithelial and evident metabolic dysregulation; and CMS4 (mesenchymal, 23%), prominent transforming growth factor-β activation, stromal invasion and angiogenesis. Samples with mixed features (13%) possibly represent a transition phenotype or intratumoral heterogeneity. We consider the CMS groups the most robust classification system currently available for CRC-with clear biological interpretability-and the basis for future clinical stratification and subtype-based targeted interventions.

HIV-1 drug resistance transmission networks in southwest Switzerland.

To determine viral subtypes and resistance mutations to antiretroviral treatment (ART) in untreated HIV-1 acutely infected subjects from Southwest Switzerland. Clinical samples were obtained from the HIV primary infection cohort from Lausanne. Briefly, pol gene was amplified by nested PCR and sequenced to generate a 1?kb sequence spanning protease and reverse transcriptase key protein regions. Nucleotide sequences were used to assess viral genotype and ART resistance mutations. Blood specimens and medical information were obtained from 30 patients. Main viral subtypes corresponded to clade B, CRF02_AG, and F1. Resistant mutations to PIs consisted of L10V and accessory mutations 16E and 60E present in all F1 clades. The NNRTI major resistant mutation 103N was detected in all F1 viruses and in other 2 clades. Additionally, we identified F1 sequences from other 6 HIV infected and untreated individuals from Southwest Switzerland, harboring nucleotide motifs and resistance mutations to ART as observed in the F1 strains from the cohort. These data reveal a high transmission rate (16.6%) for NNRTI resistant mutation 103N in a cohort of HIV acute infection. Three of the 5 resistant strains were F1 clades closely related to other F1 isolates from HIV-1 infection untreated patients also coming from Southwest Switzerland. Overall, we provide strong evidence towards an HIV-1 resistant transmission network in Southwest Switzerland. These findings have relevant implications for the local molecular mapping of HIV-1 and future ART surveillance studies in the region.

A new chemical tool (C0036E08) supports the role of adenosine A(2B) receptors in mediating human mast cell activation.

Asthma is a chronic inflammatory disease of the airways that involves many cell types, amongst which mast cells are known to be important. Adenosine, a potent bronchoconstricting agent, exerts its ability to modulate adenosine receptors of mast cells thereby potentiating derived mediator release, histamine being one of the first mediators to be released. The heterogeneity of sources of mast cells and the lack of highly potent ligands selective for the different adenosine receptor subtypes have been important hurdles in this area of research. In the present study we describe compound C0036E08, a novel ligand that has high affinity (pK(i) 8.46) for adenosine A(2B) receptors, being 9 times, 1412 times and 3090 times more selective for A(2B) receptors than for A(1), A(2A) and A(3) receptors, respectively. Compound C0036E08 showed antagonist activity at recombinant and native adenosine receptors, and it was able to fully block NECA-induced histamine release in freshly isolated mast cells from human bronchoalveolar fluid. C0036E08 has been shown to be a valuable tool for the identification of adenosine A(2B) receptors as the adenosine receptors responsible for the NECA-induced response in human mast cells. Considering the increasing interest of A(2B) receptors as a therapeutic target in asthma, this chemical tool might provide a base for the development of new anti-asthmatic drugs.

Primary pineal tumors: outcome and prognostic factors-a study from the Rare Cancer Network (RCN).

PURPOSE: To better define outcome and prognostic factors in primary pineal tumors. MATERIALS AND METHODS: Thirty-five consecutive patients from seven academic centers of the Rare Cancer Network diagnosed between 1988 and 2006 were included. Median age was 36 years. Surgical resection consisted of biopsy in 12 cases and resection in 21 (2 cases with unknown resection). All patients underwent radiotherapy and 12 patients received also chemotherapy. RESULTS: Histological subtypes were pineoblastoma (PNB) in 21 patients, pineocytoma (PC) in 8 patients and pineocytoma with intermediate differentiation in 6 patients. Six patients with PNB had evidence of spinal seeding. Fifteen patients relapsed (14 PNB and 1 PC) with PNB cases at higher risk (p = 0.031). Median survival time was not reached. Median disease-free survival was 82 months (CI 50 % 28-275). In univariate analysis, age younger than 36 years was an unfavorable prognostic factor (p = 0.003). Patients with metastases at diagnosis had poorer survival (p = 0.048). Late side effects related to radiotherapy were dementia, leukoencephalopathy or memory loss in seven cases, occipital ischemia in one, and grade 3 seizures in two cases. Side effects related to chemotherapy were grade 3-4 leucopenia in five cases, grade 4 thrombocytopenia in three cases, grade 2 anemia in two cases, grade 4 pancytopenia in one case, grade 4 vomiting in one case and renal failure in one case. CONCLUSIONS: Age and dissemination at diagnosis influenced survival in our series. The prevalence of chronic toxicity suggests that new adjuvant strategies are advisable.

Human Primary Auditory Cortex Follows the Shape of Heschl's Gyrus.

The primary auditory cortex (PAC) is central to human auditory abilities, yet its location in the brain remains unclear. We measured the two largest tonotopic subfields of PAC (hA1 and hR) using high-resolution functional MRI at 7 T relative to the underlying anatomy of Heschl's gyrus (HG) in 10 individual human subjects. The data reveals a clear anatomical-functional relationship that, for the first time, indicates the location of PAC across the range of common morphological variants of HG (single gyri, partial duplications, and complete duplications). In 20/20 individual hemispheres, two primary mirror-symmetric tonotopic maps were clearly observed with gradients perpendicular to HG. PAC spanned both divisions of HG in cases of partial and complete duplications (11/20 hemispheres), not only the anterior division as commonly assumed. Specifically, the central union of the two primary maps (the hA1-R border) was consistently centered on the full Heschl's structure: on the gyral crown of single HGs and within the sulcal divide of duplicated HGs. The anatomical-functional variants of PAC appear to be part of a continuum, rather than distinct subtypes. These findings significantly revise HG as a marker for human PAC and suggest that tonotopic maps may have shaped HG during human evolution. Tonotopic mappings were based on only 16 min of fMRI data acquisition, so these methods can be used as an initial mapping step in future experiments designed to probe the function of specific auditory fields.

Mean platelet volume in the early phase of acute ischemic stroke is not associated with severity or functional outcome.

Background: Previous studies reported an increase of mean platelet volume (MPV) in patients with acute ischemic stroke. However, its correlation with stroke severity has not been investigated. Moreover, studies on the association of MPV with functional outcome yielded inconsistent results. Methods: We included all consecutive ischemic stroke patients admitted to CHUV (Centre Hospitalier Universitaire Vaudois) Neurology Service within 24 h after stroke onset who had MPV measured on admission. The association of MPV with stroke severity (NIHSS score at admission and at 24 h) and outcome (Rankin Scale score at 3 and 12 months) was analyzed in univariate analysis. The chi(2) test was performed to compare the frequency of minor strokes (NIHSS score </=4) and good functional outcome (Rankin Scale score </=2) across MPV quartiles. The ANOVA test was used to compare MPV between stroke subtypes according to the TOAST classification. Student's two-tailed unpaired t test was performed to compare MPV between lacunar and nonlacunar strokes. MPV was generated at admission by the Sysmex XE-2100 automated cell counter (Sysmex Corporation, Kobe, Japan) from EDTA blood samples. Results: There was no significant difference in the frequency of minor strokes (p = 0.46) and good functional outcome (p = 0.06) across MPV quartiles. MPV was not associated with stroke severity or outcome in univariate analysis. There was no significant difference in MPV between stroke subtypes according to the TOAST classification (p = 0.173) or between lacunar and nonlacunar strokes (10.50 +/- 0.91 vs. 10.40 +/- 0.81 fl, p = 0.322). Conclusions: MPV, assessed within 24 h after ischemic stroke onset, is not associated with stroke severity or functional outcome.

Differential expression of peroxisome proliferator-activated receptors (PPARs): tissue distribution of PPAR-alpha, -beta, and -gamma in the adult rat.

Peroxisome proliferator-activated receptors (PPARs) are members of the nuclear hormone receptor superfamily that can be activated by various xenobiotics and natural fatty acids. These transcription factors primarily regulate genes involved in lipid metabolism and also play a role in adipocyte differentiation. We present the expression patterns of the PPAR subtypes in the adult rat, determined by in situ hybridization using specific probes for PPAR-alpha, -beta and -gamma, and by immunohistochemistry using a polyclonal antibody that recognizes the three rat PPAR subtypes. In numerous cell types from either ectodermal, mesodermal, or endodermal origin, PPARs are coexpressed, with relative levels varying between them from one cell type to the other. PPAR-alpha is highly expressed in hepatocytes, cardiomyocytes, enterocytes, and the proximal tubule cells of kidney. PPAR-beta is expressed ubiquitously and often at higher levels than PPAR-alpha and -gamma. PPAR-gamma is expressed predominantly in adipose tissue and the immune system. Our results suggest new potential directions to investigate the functions of the different PPAR subtypes.

Molecular pathology of colorectal cancer.

Colorectal cancer (CRC) is one of the most intensively studied cancer types, partly because of its high prevalence but also because of the existence of its precursor lesions, tubular or villous adenomas, and more recently (sessile) serrated adenomas, which can be detected endoscopically and removed. The morphological steps in the adenoma-carcinoma sequence have been elucidated at a molecular level, which has been facilitated by identification of the genes responsible for familial intestinal cancer. However, apart from early detection of familial forms of CRC and its use in genetic counseling, until recently such detailed molecular knowledge has had little impact on clinical management of the disease. This has dramatically changed in the last decade. With drugs specifically targeting the epidermal growth factor receptor (EGFR) having been shown effective in CRC, mechanisms responsible for resistance have been explored. The finding that KRAS mutated cancers do not respond to anti-EGFR treatment has had a profound impact on clinical management and on molecular diagnostics of CRC. Additional genetic tests for mutations in NRAS, BRAF and PIK3CA contribute to determining who to treat, and others will follow. New therapies effective in patients with advanced CRC are under investigation. Remaining burning questions for optimal management are which patients will relapse after resection of the primary tumor and which patients will respond to the standard 5FU-oxaliplatin adjuvant treatment regimen. Predictive tests to address these issues are eagerly awaited. New classifications of CRC, based on molecular parameters, are emerging, and we will be confronted with new subtypes of CRC, for which the definition is based on combinations of gene expression patterns, chromosomal alterations, gene mutations and epigenetic characteristics. This will be instrumental in designing new approaches for therapy but will also be translated into molecular diagnostics. Both will contribute to improved clinical management of CRC.