The CXCR4/CXCR7/CXCL12 Axis Is Involved in a Secondary but Complex Control of Neuroblastoma Metastatic Cell Homing.

Neuroblastoma (NB) is one of the most deadly solid tumors of the young child, for which new efficient and targeted therapies are strongly needed. The CXCR4/CXCR7/CXCL12 chemokine axis has been involved in the progression and organ-specific dissemination of various cancers. In NB, CXCR4 expression was shown to be associated to highly aggressive undifferentiated tumors, while CXCR7 expression was detected in more differentiated and mature neuroblastic tumors. As investigated in vivo, using an orthotopic model of tumor cell implantation of chemokine receptor-overexpressing NB cells (IGR-NB8), the CXCR4/CXCR7/CXCL12 axis was shown to regulate NB primary and secondary growth, although without any apparent influence on organ selective metastasis. In the present study, we addressed the selective role of CXCR4 and CXCR7 receptors in the homing phase of metastatic dissemination using an intravenous model of tumor cell implantation. Tail vein injection into NOD-scid-gamma mice of transduced IGR-NB8 cells overexpressing CXCR4, CXCR7, or both receptors revealed that all transduced cell variants preferentially invaded the adrenal gland and typical NB metastatic target organs, such as the liver and the bone marrow. However, CXCR4 expression favored NB cell dissemination to the liver and the lungs, while CXCR7 was able to strongly promote NB cell homing to the adrenal gland and the liver. Finally, coexpression of CXCR4 and CXCR7 receptors significantly and selectively increased NB dissemination toward the bone marrow. In conclusion, CXCR4 and CXCR7 receptors may be involved in a complex and organ-dependent control of NB growth and selective homing, making these receptors and their inhibitors potential new therapeutic targets.

Comment on reversal of hypogonadotropic hypogonadism in a Chinese cohort.

The reversal of congenital hypogonadotropic hypogonadism (CHH) is a relatively recent phenomenon that has gained increasing attention over the past 10 years. Yet to date, only one prospective study has been conducted estimating that 10% (95% confidence interval [CI]: 2%-18%) of cases undergo reversal. [1] Other retrospective studies have reported rates in the range of 5%-8% [2],[3] and a recent study showed 44/308 (14%, 95% CI: 11%-19%) CHH patients underwent reversal. [4] Moreover, a time-to-event analysis in this large cohort revealed a lifetime reversal incidence of 22%. The article by Mao and colleagues presented in this issue is a meaningful contribution to our understanding of reversal as it examines the largest retrospective cohort to date. [5] Interestingly, they report the rate of reversal as 5% (95% CI: 3%-8%) in this Chinese cohort. It is difficult to reconcile the discrepancies in rates of reversibility and direct comparisons are hampered by the variable definitions employed. Using a novel definition for reversal (i.e, either endogenous testosterone (T) >270 ng dl−1 , serum T gradually increasing above 150 ng dl−1 with increased testicular volume, or normal spontaneous sperm production/normal erectile function/ejaculation), Mao and colleagues posit that testicular size and triptorelin-stimulated LH levels are reliable predictive factors for reversal. However, these cannot be considered as hard and fast rules for predicting reversal as the groups intersect - akin to the overlap observed between CHH patients and those with delayed puberty. Indeed, the fact that approximately half (44%, 95% CI: 25%-66%) of the reversal patients in the study by Mao et al.[5] were diagnosed between 17 and 19 years of age, underscores the challenge in differentiating CHH from extreme normal variants of puberty. This study further lends credence the recently reported observations that reversals may relapse. [4],[6] The notion that reversal may not be lasting highlights the vulnerability of the reproductive axis among CHH patients. While the mechanism(s) for relapse are unclear, it seems plausible that environmental, metabolic or psychiatric stressors could contribute. The factors that Mao and colleagues identify as significantly different in cases of reversal, were not informative for identifying those cases that relapsed back to a hypogonadal state. Notably, reversal has been reported in probands harboring mutations in genes underlying CHH. [1],[3],[4],[6] Unfortunately, comprehensive genetic screening on the Chinese cohort is not available. The reversal phenomenon is fascinating for its glimpse into the plasticity of the neuroendocrine control of reproduction. Future directions will almost certainly include investigation of specific genetic signatures and novel biomarkers for predicting reversal (and relapse). Yet CHH is a rare condition and to fully elucidate the biology of reversible CHH, it will be important to harmonize definitions of what constitutes a reversal, carefully phenotype patients and chart the natural history of their CHH. In this way, this unique human disease model may offer further insights into the control of human reproduction and provide opportunities to translate discoveries into enhanced approaches to improve the care and quality of life for these patients.

Use of the dried blood spot sampling process coupled with fast gas chromatography and negative-ion chemical ionization tandem mass spectrometry: application to fluoxetine, norfluoxetine, reboxetine, and paroxetine analysis.

The objective of this work was to combine the advantages of the dried blood spot (DBS) sampling process with the highly sensitive and selective negative-ion chemical ionization tandem mass spectrometry (NICI-MS-MS) to analyze for recent antidepressants including fluoxetine, norfluoxetine, reboxetine, and paroxetine from micro whole blood samples (i.e., 10 microL). Before analysis, DBS samples were punched out, and antidepressants were simultaneously extracted and derivatized in a single step by use of pentafluoropropionic acid anhydride and 0.02% triethylamine in butyl chloride for 30 min at 60 degrees C under ultrasonication. Derivatives were then separated on a gas chromatograph coupled with a triple-quadrupole mass spectrometer operating in negative selected reaction monitoring mode for a total run time of 5 min. To establish the validity of the method, trueness, precision, and selectivity were determined on the basis of the guidelines of the "Société Française des Sciences et des Techniques Pharmaceutiques" (SFSTP). The assay was found to be linear in the concentration ranges 1 to 500 ng mL(-1) for fluoxetine and norfluoxetine and 20 to 500 ng mL(-1) for reboxetine and paroxetine. Despite the small sampling volume, the limit of detection was estimated at 20 pg mL(-1) for all the analytes. The stability of DBS was also evaluated at -20 degrees C, 4 degrees C, 25 degrees C, and 40 degrees C for up to 30 days. Furthermore, the method was successfully applied to a pharmacokinetic investigation performed on a healthy volunteer after oral administration of a single 40-mg dose of fluoxetine. Thus, this validated DBS method combines an extractive-derivative single step with a fast and sensitive GC-NICI-MS-MS technique. Using microliter blood samples, this procedure offers a patient-friendly tool in many biomedical fields such as checking treatment adherence, therapeutic drug monitoring, toxicological analyses, or pharmacokinetic studies.

Prolonged Period of Cortical Plasticity upon Redox Dysregulation in Fast-Spiking Interneurons.

BACKGROUND: Oxidative stress and the specific impairment of perisomatic gamma-aminobutyric acid circuits are hallmarks of the schizophrenic brain and its animal models. Proper maturation of these fast-spiking inhibitory interneurons normally defines critical periods of experience-dependent cortical plasticity. METHODS: Here, we linked these processes by genetically inducing a redox dysregulation restricted to such parvalbumin-positive cells and examined the impact on critical period plasticity using the visual system as a model (3-6 mice/group). RESULTS: Oxidative stress was accompanied by a significant loss of perineuronal nets, which normally enwrap mature fast-spiking cells to limit adult plasticity. Accordingly, the neocortex remained plastic even beyond the peak of its natural critical period. These effects were not seen when redox dysregulation was targeted in excitatory principal cells. CONCLUSIONS: A cell-specific regulation of redox state thus balances plasticity and stability of cortical networks. Mistimed developmental trajectories of brain plasticity may underlie, in part, the pathophysiology of mental illness. Such prolonged developmental plasticity may, in turn, offer a therapeutic opportunity for cognitive interventions targeting brain plasticity in schizophrenia.

CNDOL: A fast and reliable method for the calculation of electronic properties of very large systems. Applications to retinal binding pocket in rhodopsin and gas phase porphine.

Very large molecular systems can be calculated with the so called CNDOL approximate Hamiltonians that have been developed by avoiding oversimplifications and only using a priori parameters and formulas from the simpler NDO methods. A new diagonal monoelectronic term named CNDOL/21 shows great consistency and easier SCF convergence when used together with an appropriate function for charge repulsion energies that is derived from traditional formulas. It is possible to obtain a priori molecular orbitals and electron excitation properties after the configuration interaction of single excited determinants with reliability, maintaining interpretative possibilities even being a simplified Hamiltonian. Tests with some unequivocal gas phase maxima of simple molecules (benzene, furfural, acetaldehyde, hexyl alcohol, methyl amine, 2,5 dimethyl 2,4 hexadiene, and ethyl sulfide) ratify the general quality of this approach in comparison with other methods. The calculation of large systems as porphine in gas phase and a model of the complete retinal binding pocket in rhodopsin with 622 basis functions on 280 atoms at the quantum mechanical level show reliability leading to a resulting first allowed transition in 483 nm, very similar to the known experimental value of 500 nm of "dark state." In this very important case, our model gives a central role in this excitation to a charge transfer from the neighboring Glu(-) counterion to the retinaldehyde polyene chain. Tests with gas phase maxima of some important molecules corroborate the reliability of CNDOL/2 Hamiltonians.

Fast oscillatory activity in the anterior cingulate cortex: dopaminergic modulation and effect of perineuronal net loss.

Dopamine release in the prefrontal cortex plays a critical role in cognitive function such as working memory, attention and planning. Dopamine exerts complex modulation on excitability of pyramidal neurons and interneurons, and regulates excitatory and inhibitory synaptic transmission. Because of the complexity of this modulation, it is difficult to fully comprehend the effect of dopamine on neuronal network activity. In this study, we investigated the effect of dopamine on local high-frequency oscillatory neuronal activity (in β band) in slices of the mouse anterior cingulate cortex (ACC). We found that dopamine enhanced the power of these oscillations induced by kainate and carbachol, but did not affect their peak frequency. Activation of D2R and in a lesser degree D1R increased the oscillation power, while activation of D4R had no effect. These high-frequency oscillations in the ACC relied on both phasic inhibitory and excitatory transmission and functional gap junctions. Thus, dopamine released in the ACC promotes high-frequency synchronized local cortical activity which is known to favor information transfer, fast selection and binding of distributed neuronal responses. Finally, the power of these oscillations was significantly enhanced after degradation of the perineuronal nets (PNNs) enwrapping most parvalbumin interneurons. This study provides new insights for a better understanding of the abnormal prefrontal gamma activity in schizophrenia (SZ) patients who display prefrontal anomalies of both the dopaminergic system and the PNNs.

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.

Fast spin echo imaging of carotid artery dynamics.

PURPOSE: We propose the use of a retrospectively gated cine fast spin echo (FSE) sequence for characterization of carotid artery dynamics. The aim of this study was to compare cine FSE measures of carotid dynamics with measures obtained on prospectively gated FSE images. METHODS: The common carotid arteries in 10 volunteers were imaged using two temporally resolved sequences: (i) cine FSE and (ii) prospectively gated FSE. Three raters manually traced a common carotid artery area for all cardiac phases on both sequences. Measured areas and systolic-diastolic area changes were calculated and compared. Inter- and intra-rater reliability were assessed for both sequences. RESULTS: No significant difference between cine FSE and prospectively gated FSE areas were observed (P = 0.36). Both sequences produced repeatable cross-sectional area measurements: inter-rater intraclass correlation coefficient (ICC) = 0.88 on cine FSE images and 0.87 on prospectively gated FSE images. Minimum detectable difference (MDD) in systolic-diastolic area was 4.9 mm(2) with cine FSE and 6.4 mm(2) with prospectively gated FSE. CONCLUSION: This cine FSE method produced repeatable dynamic carotid artery measurements with less artifact and greater temporal efficiency compared with prospectively gated FSE. Magn Reson Med 74:1103-1109, 2015. © 2014 Wiley Periodicals, Inc.

Fast and Rigorous Computation of Gene and Pathway Scores from SNP-Based Summary Statistics.

Integrating single nucleotide polymorphism (SNP) p-values from genome-wide association studies (GWAS) across genes and pathways is a strategy to improve statistical power and gain biological insight. Here, we present Pascal (Pathway scoring algorithm), a powerful tool for computing gene and pathway scores from SNP-phenotype association summary statistics. For gene score computation, we implemented analytic and efficient numerical solutions to calculate test statistics. We examined in particular the sum and the maximum of chi-squared statistics, which measure the strongest and the average association signals per gene, respectively. For pathway scoring, we use a modified Fisher method, which offers not only significant power improvement over more traditional enrichment strategies, but also eliminates the problem of arbitrary threshold selection inherent in any binary membership based pathway enrichment approach. We demonstrate the marked increase in power by analyzing summary statistics from dozens of large meta-studies for various traits. Our extensive testing indicates that our method not only excels in rigorous type I error control, but also results in more biologically meaningful discoveries.

'Fast-implantable' aortic valve implantation and concomitant mitral procedures.

Concomitant aortic and mitral valve replacement or concomitant aortic valve replacement and mitral repair can be a challenge for the cardiac surgeon: in particular, because of their structure and design, two bioprosthetic heart valves or an aortic valve prosthesis and a rigid mitral ring can interfere at the level of the mitroaortic junction. Therefore, when a mitral bioprosthesis or a rigid mitral ring is already in place and a surgical aortic valve replacement becomes necessary, or when older high-risk patients require concomitant mitral and aortic procedures, the new 'fast-implantable' aortic valve system (Intuity valve, Edwards Lifesciences, Irvine, CA, USA) can represent a smart alternative to standard aortic bioprosthesis. Unfortunately, this is still controversial (risk of interference). However, transcatheter aortic valve replacements have been performed in patients with previously implanted mitral valves or mitral rings. Interestingly, we learned that there is no interference (or not significant interference) among the standard valve and the stent valve. Consequently, we can assume that a fast-implantable valve can also be safely placed next to a biological mitral valve or next to a rigid mitral ring without risks of distortion, malpositioning, high gradient or paravalvular leak. This paper describes two cases: a concomitant Intuity aortic valve and bioprosthetic mitral valve implantation and a concomitant Intuity aortic valve and mitral ring implantation.

Fast and sensitive supercritical fluid chromatography - tandem mass spectrometry multi-class screening method for the determination of doping agents in urine.

This study shows the possibility offered by modern ultra-high performance supercritical fluid chromatography combined with tandem mass spectrometry in doping control analysis. A high throughput screening method was developed for 100 substances belonging to the challenging classes of anabolic agents, hormones and metabolic modulators, synthetic cannabinoids and glucocorticoids, which should be detected at low concentrations in urine. To selectively extract these doping agents from urine, a supported liquid extraction procedure was implemented in a 48-well plate format. At the tested concentration levels ranging from 0.5 to 5 ng/mL, the recoveries were better than 70% for 48-68% of the compounds and higher than 50% for 83-87% of the tested substances. Due to the numerous interferences related to isomers of steroids and ions produced by the loss of water in the electrospray source, the choice of SFC separation conditions was very challenging. After careful optimization, a Diol stationary phase was employed. The total analysis time for the screening assay was only 8 min, and interferences as well as susceptibility to matrix effect (ME) were minimized. With the developed method, about 70% of the compounds had relative ME within the range ±20%, at a concentration of 1 and 5 ng/mL. Finally, limits of detection achieved with the above-described strategy including 5-fold preconcentration were below 0.1 ng/mL for the majority of the tested compounds. Therefore, LODs were systematically better than the minimum required performance levels established by the World anti-doping agency, except for very few metabolites.