How Does Target Lesion Selection Affect RECIST? A Computer Simulation Study.

OBJECTIVES: Response Evaluation Criteria in Solid Tumors (RECIST) is grounded on the assumption that target lesion selection is objective and representative of the change in total tumor burden (TTB) during therapy. A computer simulation model was designed to challenge this assumption, focusing on a particular aspect of subjectivity: target lesion selection. MATERIALS AND METHODS: Disagreement among readers and the disagreement between individual reader measurements and TTB were analyzed as a function of the total number of lesions, affected organs, and lesion growth. RESULTS: Disagreement rises when the number of lesions increases, when lesions are concentrated on a few organs, and when lesion growth borders the thresholds of progressive disease and partial response. There is an intrinsic methodological error in the estimation of TTB via RECIST 1.1, which depends on the number of lesions and their distributions. For example, for a fixed number of lesions at 5 and 15, distributed over a maximum of 4 organs, the error rates are observed to be 7.8% and 17.3%, respectively. CONCLUSIONS: Our results demonstrate that RECIST can deliver an accurate estimate of TTB in localized disease, but fails in cases of distal metastases and multiple organ involvement. This is worsened by the "selection of the largest lesions," which introduces a bias that makes it hardly possible to perform an accurate estimate of the TTB. Including more (if not all) lesions in the quantitative analysis of tumor burden is desirable.

Estimating pregnancy rate from blubber progesterone levels of a blindly biopsied beluga population poses methodological, analytical and statistical challenges.

Beluga (Delphinapterus leucas) from the St. Lawrence Estuary, Canada, have been declining since the early 2000s, suggesting recruitment issues as a result of low fecundity, abnormal abortion rates or poor calf or juvenile survival. Pregnancy is difficult to observe in cetaceans, making the ground truthing of pregnancy estimates in wild individuals challenging. Blubber progesterone concentrations were contrasted among 62 SLE beluga with a known reproductive state (i.e. pregnant, resting, parturient and lactating females), that were found dead in 1997 to 2019. The suitability of a threshold obtained from decaying carcasses to assess reproductive state and pregnancy rate of freshly-dead or free-ranging and blindly-sampled beluga was examined using three statistical approaches and two data sets (135 freshly harvested carcasses in Nunavik, and 65 biopsy-sampled SLE beluga). Progesterone concentrations in decaying carcasses were considerably higher in known-pregnant (mean ± sd: 365 ± 244 ng g-1 of tissue) than resting (3.1 ± 4.5 ng g-1 of tissue) or lactating (38.4 ± 100 ng g-1 of tissue) females. An approach based on statistical mixtures of distributions and a logistic regression were compared to the commonly-used, fixed threshold approach (here, 100 ng g-1) for discriminating pregnant from non-pregnant females. The error rate for classifying individuals of known reproductive status was the lowest for the fixed threshold and logistic regression approaches, but the mixture approach required limited a priori knowledge for clustering individuals of unknown pregnancy status. Mismatches in assignations occurred at lipid content < 10% of sample weight. Our results emphasize the importance of reporting lipid contents and progesterone concentrations in both units (ng g-1 of tissue and ng g-1 of lipid) when sample mass is low. By highlighting ways to circumvent potential biases in field sampling associated with capturability of different segments of a population, this study also enhances the usefulness of the technique for estimating pregnancy rate of free-ranging population.

ShrinkCRISPR: a flexible method for differential fitness analysis of CRISPR-Cas9 screen data.

BACKGROUND: CRISPR screens provide large-scale assessment of cellular gene functions. Pooled libraries typically consist of several single guide RNAs (sgRNAs) per gene, for a large number of genes, which are transduced in such a way that every cell receives at most one sgRNA, resulting in the disruption of a single gene in that cell. This approach is often used to investigate effects on cellular fitness, by measuring sgRNA abundance at different time points. Comparing gene knockout effects between different cell populations is challenging due to variable cell-type specific parameters and between replicates variation. Failure to take those into account can lead to inflated or false discoveries. RESULTS: We propose a new, flexible approach called ShrinkCRISPR that can take into account multiple sources of variation. Impact on cellular fitness between conditions is inferred by using a mixed-effects model, which allows to test for gene-knockout effects while taking into account sgRNA-specific variation. Estimates are obtained using an empirical Bayesian approach. ShrinkCRISPR can be applied to a variety of experimental designs, including multiple factors. In simulation studies, we compared ShrinkCRISPR results with those of drugZ and MAGeCK, common methods used to detect differential effect on cell fitness. ShrinkCRISPR yielded as many true discoveries as drugZ using a paired screen design, and outperformed both drugZ and MAGeCK for an independent screen design. Although conservative, ShrinkCRISPR was the only approach that kept false discoveries under control at the desired level, for both designs. Using data from several publicly available screens, we showed that ShrinkCRISPR can take data for several time points into account simultaneously, helping to detect early and late differential effects. CONCLUSIONS: ShrinkCRISPR is a robust and flexible approach, able to incorporate different sources of variations and to test for differential effect on cell fitness at the gene level. These improve power to find effects on cell fitness, while keeping multiple testing under the correct control level and helping to improve reproducibility. ShrinkCrispr can be applied to different study designs and incorporate multiple time points, making it a complete and reliable tool to analyze CRISPR screen data.

STochastic Optical Reconstruction Microscopy (STORM) reveals the nanoscale organization of pathological aggregates in human brain.

AIMS: Histological analysis of brain tissue samples provides valuable information about the pathological processes leading to common neurodegenerative disorders. In this context, the development of novel high-resolution imaging approaches is a current challenge in neuroscience. METHODS: To this end, we used a recent super-resolution imaging technique called STochastic Optical Reconstruction Microscopy (STORM) to analyse human brain sections. We combined STORM cell imaging protocols with neuropathological techniques to image cryopreserved brain samples from control subjects and patients with neurodegenerative diseases. RESULTS: This approach allowed us to perform 2D-, 3D- and two-colour-STORM in neocortex, white matter and brainstem samples. STORM proved to be particularly effective at visualizing the organization of dense protein inclusions and we imaged with a <50 nm resolution pathological aggregates within the central nervous system of patients with Alzheimer's disease, Parkinson's disease, Lewy body dementia and fronto-temporal lobar degeneration. Aggregated Aß branches appeared reticulated and cross-linked in the extracellular matrix, with widths from 60 to 240 nm. Intraneuronal Tau and TDP-43 inclusions were denser, with a honeycomb pattern in the soma and a filamentous organization in the axons. Finally, STORM imaging of α-synuclein pathology revealed the internal organization of Lewy bodies that could not be observed by conventional fluorescence microscopy. CONCLUSIONS: STORM imaging of human brain samples opens further gates to a more comprehensive understanding of common neurological disorders. The convenience of this technique should open a straightforward extension of its application for super-resolution imaging of the human brain, with promising avenues to current challenges in neuroscience.

Altered Neurobiological Processing of Unintentional Social Norm Violations: A Multiplex, Multigenerational Functional Magnetic Resonance Imaging Study on Social Anxiety Endophenotypes.

BACKGROUND: Patients with social anxiety disorder (SAD) fear negative evaluation in social situations. Specifically, previous work indicated that social anxiety is associated with increased medial prefrontal cortex activation in response to unintentional social norm (SN) transgressions, accompanied by increased embarrassment ratings for such SN violations. Here, we used data from the multiplex, multigenerational LFLSAD (Leiden Family Lab study on Social Anxiety Disorder), which involved two generations of families genetically enriched for SAD, and investigated whether these neurobiological and behavioral correlates of unintentional SN processing are SAD endophenotypes. Of four endophenotype criteria, we examined two: first, the cosegregation of these characteristics with social anxiety (SA) within families of SAD probands (criterion 4), and second, the heritability of the candidate endophenotypes (criterion 3). METHODS: Participants (n = 110, age range 9.0-61.5 years, eight families) performed the revised Social Norm Processing Task; functional magnetic resonance imaging data and behavioral ratings related to this paradigm were used to examine whether brain activation in response to processing unintentional SN violations and ratings of embarrassment were associated with SA levels. Next, heritability of these measurements was estimated. RESULTS: As expected, voxelwise functional magnetic resonance imaging analyses revealed positive associations between SA levels and brain activation in the medial prefrontal cortex and medial temporal gyrus, superior temporal gyrus, and superior temporal sulcus, and these brain activation levels displayed moderate to moderately high heritability. Furthermore, although SA levels correlated positively with behavioral ratings of embarrassment for SN transgressions, these behavioral characteristics were not heritable. CONCLUSIONS: These results show, for the first time, that brain responses in the medial prefrontal cortex and medial temporal gyrus, superior temporal gyrus, and superior temporal sulcus, related to processing unintentional SN violations, provide a neurobiological candidate endophenotype of SAD.

Impaired neural habituation to neutral faces in families genetically enriched for social anxiety disorder.

BACKGROUND: Social anxiety disorder (SAD) is an incapacitating disorder running in families. Previous work associated social fearfulness with a failure to habituate, but the habituation response to neutral faces has, as of yet, not been investigated in patients with SAD and their family members concurrently. Here, we examined whether impaired habituation to neutral faces is a putative neurobiological endophenotype of SAD by using data from the multiplex and multigenerational Leiden Family Lab study on SAD. METHODS: Participants (n = 110; age, 9.2 - 61.5 years) performed a habituation paradigm involving neutral faces, as these are strong social stimuli with an ambiguous meaning. We used functional magnetic resonance imaging data to investigate whether brain activation related to habituation was associated with the level of social anxiety within the families. Furthermore, the heritability of the neural habituation response was estimated. RESULTS: Our data revealed a relationship between impaired habituation to neutral faces and social anxiety in the right hippocampus and right amygdala. In addition, our data indicated that this habituation response displayed moderate - to-moderately high heritability in the right hippocampus. CONCLUSION: The present results provide support for altered habituation as a candidate SAD endophenotype; impaired neural habitation cosegregrated with the disorder within families and was heritable. These findings shed light on the genetic susceptibility to SAD.

Genome-wide analysis in multiple-case families: assessing the relationship between triglyceride and methylation.

The main goal of this paper is to estimate the effect of triglyceride levels on methylation of cytosine-phosphate-guanine (CpG) sites in multiple-case families. These families are selected because they have 2 or more cases of metabolic syndrome (primary phenotype). The methylations at the CpG sites are the secondary phenotypes. Ascertainment corrections are needed when there is an association between the primary and secondary phenotype. We will apply the newly developed secondary phenotype analysis for multiple-case family studies to identify CpG sites where methylations are influenced by triglyceride levels. Our second goal is to compare the performance of the naïve approach, which ignores the sampling of the families, SOLAR (Sequential Oligogenic Linkage Analysis Routines), which adjusts for ascertainment via probands, and the secondary phenotype approach. The analysis of possible CpG sites associated with triglyceride levels shows results consistent with the literature when using the secondary phenotype approach. Overall, the secondary phenotype approach performed well, but the comparison of the different approaches does not show significant differences between them. However, for genome-wide applications, we recommend using the secondary phenotype approach when there is an association between primary and secondary phenotypes, and to use the naïve approach otherwise.

Subcortical brain volumes, cortical thickness and cortical surface area in families genetically enriched for social anxiety disorder - A multiplex multigenerational neuroimaging study.

BACKGROUND: Social anxiety disorder (SAD) is a disabling psychiatric condition with a genetic background. Brain alterations in gray matter (GM) related to SAD have been previously reported, but it remains to be elucidated whether GM measures are candidate endophenotypes of SAD. Endophenotypes are measurable characteristics on the causal pathway from genotype to phenotype, providing insight in genetically-based disease mechanisms. Based on a review of existing evidence, we examined whether GM characteristics meet two endophenotype criteria, using data from a unique sample of SAD-patients and their family-members of two generations. First, we investigated whether GM characteristics co-segregate with social anxiety within families genetically enriched for SAD. Secondly, heritability of the GM characteristics was estimated. METHODS: Families with a genetic predisposition for SAD participated in the Leiden Family Lab study on SAD; T1-weighted MRI brain scans were acquired (n = 110, 8 families). Subcortical volumes, cortical thickness and cortical surface area were determined for a-priori determined regions of interest (ROIs). Next, associations with social anxiety and heritabilities were estimated. FINDINGS: Several subcortical and cortical GM characteristics, derived from frontal, parietal and temporal ROIs, co-segregated with social anxiety within families (uncorrected p-level) and showed moderate to high heritability. INTERPRETATION: These findings provide preliminary evidence that GM characteristics of multiple ROIs, which are distributed over the brain, are candidate endophenotypes of SAD. Thereby, they shed light on the genetic vulnerability for SAD. Future research is needed to confirm these results and to link them to functional brain alterations and to genetic variations underlying these GM changes. FUND: Leiden University Research Profile 'Health, Prevention and the Human Life Cycle'.

The Leiden Family Lab study on Social Anxiety Disorder: A multiplex, multigenerational family study on neurocognitive endophenotypes.

OBJECTIVES: Social anxiety disorder (SAD) is a serious and prevalent psychiatric condition, with a heritable component. However, little is known about the characteristics that are associated with the genetic component of SAD, the so-called "endophenotypes". These endophenotypes could advance our insight in the genetic susceptibility to SAD, as they are on the pathway from genotype to phenotype. The Leiden Family Lab study on Social Anxiety Disorder (LFLSAD) is the first multiplex, multigenerational study aimed to identify neurocognitive endophenotypes of social anxiety. METHODS: The LFLSAD is characterized by a multidisciplinary approach and encompasses a variety of measurements, including a clinical interview, functional and structural magnetic resonance imaging and an electroencephalography experiment. Participants are family members from 2 generations, from families genetically enriched for SAD. RESULTS: The sample (n = 132 participants, from 9 families) was characterized by a high prevalence of SAD, in both generations (prevalence (sub)clinical SAD: 38.3%). Furthermore, (sub)clinical SAD was positively related to self-reported social anxiety, fear of negative evaluation, trait anxiety, behavioral inhibition, negative affect, and the level of depressive symptoms. CONCLUSIONS: By the multidimensional character of the measurements and thorough characterization of the sample, the LFLSAD offers unique opportunities to investigate candidate neurocognitive endophenotypes of SAD.

Behavioral and EEG responses to social evaluation: A two-generation family study on social anxiety.

Social anxiety disorder is an invalidating psychiatric disorder characterized by extreme fear and avoidance of one or more social situations in which patients might experience scrutiny by others. The goal of this two-generation family study was to delineate behavioral and electrocortical endophenotypes of social anxiety disorder related to social evaluation. Nine families of patients with social anxiety disorder (their spouse and children, and siblings of these patients with spouse and children) performed a social judgment paradigm in which they believed to be evaluated by peers. For each peer, participants indicated their expectation about the evaluative outcome, after which they received social acceptance or rejection feedback. Task behavior, as well as the feedback-related EEG brain potentials (N1, FRN, P3) and theta power were tested as candidate endophenotypes based on two criteria: co-segregation with social anxiety disorder within families and heritability. Results indicated that reaction time for indicating acceptance-expectations might be a candidate behavioral endophenotype of social anxiety disorder, possibly reflecting increased uncertainty or self-focused attention and vigilance during the social judgment paradigm. N1 in response to expected rejection feedback and P3 in response to acceptance feedback might be candidate electrocortical endophenotypes of social anxiety disorder, although the heritability analyses did not remain significant after correcting for multiple tests. Increased N1 possibly reflects hypervigilance to socially threatening stimuli, and increased P3 might reflect that positive feedback is more important for, and/or less expected by, participants with social anxiety disorder. Finally, increased feedback-related negativity and theta power in response to unexpected rejection feedback compared to the other conditions co-segregated with social anxiety disorder, but these EEG measures were not heritable. The candidate endophenotypes might play a new and promising role in future research on genetic mechanisms, early detection and/or prevention of social anxiety disorder.

Polarization mechanisms of dielectric materials at a binary liquid interface: impacts on electrowetting actuation.

We explored polarization mechanisms at the interface between a dielectric material (an electrolyte) and an insulating liquid, during electrowetting actuation. Native surface charge density due to hydrophobic coating has been measured as an offset voltage for which the contact angle is at its minimum. Surface charge densities as low as 0.023 mC m-2 have been measured using this method, demonstrating that electrowetting can be used as a probe to measure native surface charge density. This effect strongly differs depending on the kind of polarization and is at the origin of major discrepancies between alternative and direct polarization during electrowetting actuation. A new model describing electrowetting actuation is also proposed, leading to a more predictive description as well as useful recommendations on materials to obtain a stable actuation under DC polarization.

The impact of ageing, fasting and high-fat diet on central and peripheral glucose tolerance and glucose-sensing neural networks in the arcuate nucleus.

Obesity and ageing are risk factors for diabetes. In the present study, we investigated the effects of ageing, obesity and fasting on central and peripheral glucose tolerance and on glucose-sensing neuronal function in the arcuate nucleus of rats, with a view to providing insight into the central mechanisms regulating glucose homeostasis and how they change or are subject to dysfunction with ageing and obesity. We show that, following a glucose load, central glucose tolerance at the level of the cerebrospinal fluid (CSF) and plasma is significantly reduced in rats maintained on a high-fat diet (HFD). With ageing, up to 2 years, central glucose tolerance was impaired in an age-dependent manner, whereas peripheral glucose tolerance remained unaffected. Ageing-induced peripheral glucose intolerance was improved by a 24-hour fast, whereas central glucose tolerance was not corrected. Pre-wean, immature animals have elevated basal plasma glucose levels and a delayed increase in central glucose levels following peripheral glucose injection compared to mature animals. Electrophysiological recording techniques revealed an energy-status-dependent role for glucose-excited, inhibited and adapting neurones, along with glucose-induced changes in synaptic transmission. We conclude that ageing affects central glucose tolerance, whereas HFD profoundly affects central and peripheral glucose tolerance and, in addition, glucose-sensing neurones adapt function in an energy-status-dependent manner.

Synchrotron X-ray microtransections: a non invasive approach for epileptic seizures arising from eloquent cortical areas.

Synchrotron-generated X-ray (SRX) microbeams deposit high radiation doses to submillimetric targets whilst minimizing irradiation of neighboring healthy tissue. We developed a new radiosurgical method which demonstrably transects cortical brain tissue without affecting adjacent regions. We made such image-guided SRX microtransections in the left somatosensory cortex in a rat model of generalized epilepsy using high radiation doses (820 Gy) in thin (200 µm) parallel slices of tissue. This procedure, targeting the brain volume from which seizures arose, altered the abnormal neuronal activities for at least 9 weeks, as evidenced by a decrease of seizure power and coherence between tissue slices in comparison to the contralateral cortex. The brain tissue located between transections stayed histologically normal, while the irradiated micro-slices remained devoid of myelin and neurons two months after irradiation. This pre-clinical proof of concept highlights the translational potential of non-invasive SRX transections for treating epilepsies that are not eligible for resective surgery.

Endocannabinoid 2-AG and intracellular cannabinoid receptors modulate a low-threshold calcium spike-induced slow depolarizing afterpotential in rat thalamic paraventricular nucleus neurons.

In rat paraventricular thalamic nucleus (PVT) neurons, activation of low-threshold calcium (Ca(2+)) channels triggers a low-threshold spike (LTS) which may be followed by slow afterpotentials that can dramatically influence action potential patterning. Using gluconate-based internal recording solutions, we investigated the properties of a LTS-induced slow afterdepolarization (sADP) observed in a subpopulation of PVT neurons recorded in brain slice preparations. This LTS-induced sADP required T-type Ca(2+) channel opening, exhibited variable magnitudes between neurons and a voltage dependency with a maximum near -50 mV. The area under the sADP remained stable during control monitoring, but displayed gradual suppression in media where strontium replaced Ca(2+). The sADP was suppressed following bath application of 2-APB or ML204, suggesting engagement of transient receptor potential canonical (TRPC)-like channels. Further investigation revealed a reversible suppression during bath applications of membrane permeable cannabinoid receptor (CBR) blockers rimonabant, AM630 or SR144528 suggesting the presence of both CB1Rs and CB2Rs. Similar results were achieved by intracellular, but not bath application of the membrane impermeant CB1R blocker hemopressin, suggesting an intracellular localization of CB1Rs. Data from pharmacologic manipulation of endocannabinoid biosynthetic pathways suggested 2-arachidonlyglycerol (2-AG) as the endogenous cannabinoid ligand, derived via hydrolysis of diacylglycerol (DAG), with the latter formed from the pathway involving phosphatidylcholine-specific phospholipase D and phosphatic acid phosphohydrolase. The sADP suppression observed during recordings with pipettes containing LY294002, a PI3-kinase inhibitor, suggested a role for PI3kinase in the translocation of these TRPC-like channels to the plasma membrane. Drug-induced attenuation of the availability of 2-AG influences the number of action potentials that surmount the LTS evoked in PVT neurons, implying an ongoing intracellular CBR modulation of neuronal excitability during LTS-induced bursting behavior.

Intracellular postsynaptic cannabinoid receptors link thyrotropin-releasing hormone receptors to TRPC-like channels in thalamic paraventricular nucleus neurons.

In rat thalamic paraventricular nucleus of thalamus (PVT) neurons, activation of thyrotropin-releasing hormone (TRH) receptors enhances excitability via concurrent decrease in G protein-coupled inwardly-rectifying potassium (GIRK)-like and activation of transient receptor potential cation (TRPC)4/5-like cationic conductances. An exploration of intracellular signaling pathways revealed the TRH-induced current to be insensitive to phosphatidylinositol-specific phospholipase C (PI-PLC) inhibitors, but reduced by D609, an inhibitor of phosphatidylcholine-specific PLC (PC-PLC). A corresponding change in the I-V relationship implied suppression of the cationic component of the TRH-induced current. Diacylglycerol (DAG) is a product of the hydrolysis of PC. Studies focused on the isolated cationic component of the TRH-induced response revealed a reduction by RHC80267, an inhibitor of DAG lipase, the enzyme involved in the hydrolysis of DAG to the endocannabinoid 2-arachidonoylglycerol (2-AG). Further investigation revealed enhancement of the cationic component in the presence of either JZL184 or WWL70, inhibitors of enzymes involved in the hydrolysis of 2-AG. A decrease in the TRH-induced response was noted in the presence of rimonabant or SR144528, membrane permeable CB1 and CB2 receptor antagonists, respectively. A decrease in the TRH-induced current by intracellular, but not by bath application of the membrane impermeable peptide hemopressin, selective for CB1 receptors, suggests a postsynaptic intracellular localization of these receptors. The TRH-induced current was increased in the presence of arachidonyl-2'-chloroethylamide (ACEA) or JWH133, CB1 and CB2 receptor agonists, respectively. The PI3-kinase inhibitor LY294002, known to inhibit TRPC translocation, decreased the response to TRH. In addition, a TRH-induced enhancement of the low-threshold spike was prevented by both rimonabant, and SR144528. TRH had no influence on excitatory or inhibitory miniature postsynaptic currents, suggesting presynaptic CB receptors are not involved in this situation. Collectively, the data imply that activation of TRH receptors in these midline thalamic neurons engages novel signaling pathways that include postsynaptic intracellular CB1 and CB2 receptors in the activation of TRPC4/5-like channels.

An aptasensor for ochratoxin A based on grafting of polyethylene glycol on a boron-doped diamond microcell.

A novel strategy for the fabrication of an electrochemical label-free aptasensor for small-size molecules is proposed and demonstrated as an aptasensor for ochratoxin A (OTA). A long spacer chain of polyethylene glycol (PEG) was immobilized on a boron-doped diamond (BDD) microcell via electrochemical oxidation of its terminal amino groups. The amino-aptamer was then covalently linked to the carboxyl end of the immobilized PEG as a two-piece macromolecule, autoassembled at the BDD surface, forming a dense layer. Due to a change in conformation of the aptamer on the target analyte binding, a decrease of the electron transfer rate of the redox [Fe(CN)6](4-/3-) probe was observed. To quantify the amount of OTA, the decrease of the square wave voltammetry (SWV) peak maximum of this probe was monitored. The plot of the peak maximum against the logarithm of OTA concentration was linear along the range from 0.01 to 13.2 ng/L, with a detection limit of 0.01 ng/L. This concept was validated on spiked real samples of rice.

[Pomalidomide for multiple myeloma]. / Le pomalidomide dans le myélome multiple.

Once characterized by a very poor outcome, multiple myeloma (MM) now has a significantly prolonged survival, with major improvements allowed by the use of "novel agents": proteasome inhibitors (first-in-class bortezomib) and immunomodulatory compounds (IMiDs; first-in-class thalidomide and lenalidomide). However, the vast majority - if not all - of patients with MM ultimately end up being refractory to all existing drugs, including these efficient novel agents. There is a clear unmet medical need in this situation, which warrants the development of the next generation of proteasome inhibitors and IMiDs, as well as new drug classes. This review focuses on pomalidomide, the next generation IMiD, recently approved by the US FDA and the EMA for patients with relapsed or refractory MM who have received at least two prior therapies, including lenalidomide and bortezomib, and have demonstrated disease progression on their last therapy.

[Monoclonal gammopathies of undetermined significance do not systematically require a specialized consultation]. / Les gammapathies monoclonales de signification indéterminée ne nécessitent pas systématiquement un recours à une consultation spécialisée.

INTRODUCTION: Monoclonal gammopathy of undetermined significance (MGUS) is a frequent entity in the general population. The incidence rate of fortuitous discovery of a monoclonal component in asymptomatic patients is increasing nowadays. The majority of MGUS is being addressed to a hematologist for diagnosis or follow-up by their generalist practitioners. The management of MGUS consists of a clinical and biological surveillance as per published and validated international guidelines available for MGUS diagnosis and follow-up. MGUS thus may not necessarily need a specialized consultation and follow-up in a hematology ward, as we believe it could be performed by generalist practitioners. METHODS: We studied 190 patients addressed to our hematology department of Lille for diagnosis or follow-up of MGUS. RESULTS: Among the patients, 9.5% developed a malignant hemopathy (multiple myeloma or Waldenström macroglobulinemia). Among patients diagnosed with MGUS of IgG isotype and a monoclonal component <15 g/L, 96.2% showed no pejorative outcome: these represent simple and routine prognostic factors that can be assessed at diagnosis in order to predict the risk of progression. Those patients could have easily been followed by their generalist practitioner from the diagnosis of MGUS. CONCLUSION: A specialist's consultation would still be recommended for patients with pejorative factors at diagnosis, or if a clinical or biological event that could suggest progression occurs during follow-up, or in case of MGUS with complication, in which cases patients would need a specialized management in a hematology department.

Gastrin-releasing peptide acts via postsynaptic BB2 receptors to modulate inward rectifier K+ and TRPV1-like conductances in rat paraventricular thalamic neurons.

Gastrin-releasing peptide (GRP) is a bombesin-like peptide with a widespread distribution in mammalian CNS, where it has a role in food intake, circadian rhythm generation, fear memory, itch sensation and sexual behaviour. While it has been established that GRP predominantly excites neurons, details of the membrane mechanism involved in this action remain largely undefined. We used perforated patch clamp recording in acute brain slice preparations to investigate GRP-affected receptors and ionic conductances in neurons of the rat paraventricular thalamic nucleus (PVT). PVT is a component of the midline and intralaminar thalamus that participates in arousal, motivational drives and stress responses, and exhibits a prominence of GRP-like immunoreactive fibres. Exposure of PVT neurons to low nanomolar concentrations of GRP induced sustained TTX-resistant membrane depolarizations that could trigger rhythmic burst discharges or tonic firing. Membrane current analyses in voltage clamp revealed an underlying postsynaptic bombesin type 2 receptor-mediated inward current that resulted from the simultaneous suppression of a Ba(2+)-sensitive inward rectifier K(+) conductance and activation of a non-selective cation conductance with biophysical and pharmacological properties reminiscent of transient receptor potential vanilloid (TRPV) 1. A role for a TRPV1-like conductance was further implied by a significant suppressant influence of a TRPV1 antagonist on GRP-induced membrane depolarization and rhythmic burst or tonic firing. The results provide a detailed picture of the receptor and ionic conductances that are involved in GRP's excitatory action in midline thalamus.

Pragmatic reconstruction methods in atom probe tomography.

Data collected in atom probe tomography have to be carefully analysed in order to give reliable composition data accurately and precisely positioned in the probed volume. Indeed, the large analysed surfaces of recent instruments require reconstruction methods taking into account not only the tip geometry but also accurate knowledge of geometrical projection parameters. This is particularly crucial in the analysis of multilayers materials or planar interfaces. The current work presents a simulation model that enables extraction of the two main projection features as a function of the tip and atom probe instrumentation geometries. Conversely to standard assumptions, the image compression factor and the field factor vary significantly during the analysis. An improved reconstruction method taking into account the intrinsic shape of a sample containing planar features is proposed to overcome this shortcoming.