Biopsy of breast microcalcifications using an 11-Gauge vacuum-assisted device: roles and challenges for the pathologist

Stereotactic 11-Gauge vacuum-assisted biopsy provides a valuable tool in the diagnosis of mammographically detected breast microcalcifications. However, this new diagnostic technology presents some limitations and requires a close collaboration between radiologists, pathologists and physicians. The aim of this work is to propose a practical approach in the management of large core biopsies and to summarize the different difficulties faced by the pathologist in the management and histological interpretation of specimens issuing from this device.     

Testing of a whole genome PCR scanning approach to identify genomic variability in four different species of lactic acid bacteria

Genomes can be markedly heterogeneous in conspecific bacterial strains. Genome sequences can be used to analyze genome plasticity via a PCR(2) (plasticity of chromosome revealed by PCR) approach. Small-sized chromosomes can indeed be fully amplified by long-range PCR with a set of primers designed using a reference strain and then applied to several other strains. Analysis of the resulting patterns can reveal genome plasticity. GenoFrag, a software package for the design of primers optimized for PCR(2) [N. Ben Zakour, M. Gautier, R. Andonov, D. Lavenier, M.F. Cochet, P. Veber, A. Sorokin, Y. Le Loir, GenoFrag: Software to design primers optimized for whole genome scanning by long-range PCR amplification, Nucleic Acids Res. 32 (2004) 17-24] was developed for the analysis of bacterial genome plasticity by whole genome amplification in approximately 10-kb-long fragments. By applying GenoFrag, we provide herewith evidence that genome plasticity can be analyzed in lactic acid bacteria using a PCR(2) approach. The genome sequences of Lactococcus lactis IL1403, Lactobacillus plantarum WCFS1, Lactobacillus bulgaricus ATCC11842 and Bifidobacterium longum NCC2705 were used to design four sets of primers. Each set was evaluated in silico to check that it ensured optimum coverage of the bacterial chromosome. To validate the primers generated by GenoFrag, a subset of primers was successfully used in LR-PCR experiments on genomic DNA from four L. bulgaricus strains.     

Evaluation of different tests based on observations for external model evaluation of population analyses

To evaluate by simulation the statistical properties of normalized prediction distribution errors (NPDE), prediction discrepancies (pd), standardized prediction errors (SPE), numerical predictive check (NPC) and decorrelated NPC (NPC_dec) for the external evaluation of a population pharmacokinetic analysis, and to illustrate the use of NPDE for the evaluation of covariate models. We assume that a model M_B has been built using a building dataset B, and that a separate validation dataset, V is available. Our null hypothesis H₀ is that the data in V can be described by M_B. We use several methods to test this hypothesis: NPDE, pd, SPE, NPC and NPC_dec. First, we evaluated by simulation the type I error under H₀ of different tests applied to the four methods. We also propose and evaluate a single global test combining normality, mean and variance tests applied to NPDE, pd and SPE. We perform tests on NPC and NPC_dec, after a decorrelation. M_B was a one compartment model with first order absorption (without covariate), previously developed from two phase II and one phase III studies of the antidiabetic drug, gliclazide. We simulated 500 external datasets according to the design of a phase III study. Second, we investigated the application of NPDE to covariate models. We propose two approaches: the first approach uses correlation tests or mean comparisons to test the relationship between NPDE and covariates; the second evaluates NPDE split by category for discrete covariates or quantiles for continuous covariates. We generated several validation datasets under H₀ and under alternative assumptions with a model without covariate, with one continuous covariate (weight), or one categorical covariate (sex). We calculated the powers of the different tests using simulations, where the covariates of the phase III study were used. The simulations under H₀ show a high type I error for the different tests applied to SPE and an increased type I error for pd. The different tests present a type I error close to 5% for the global test appied to NPDE. We find a type I error higher than 5% for the test applied to classical NPC but this test becomes close to 5% for NPC_dec. For covariate models, when model and validation dataset are consistent, type I error of the tests are close to 5% for both effects. When validation datasets and models are not consistent, the tests detect the correlation between NPDE and the covariate. We recommend to use NPDE over SPE for external model evaluation, since they do not depend on an approximation of the model and have good statistical properties. NPDE represent a better approach than NPC, since in order to perform tests on NPC, a decorrelation step must be applied before. NPDE, in this illustration, is also a good tool to evaluate model with or without covariates.     

Aortic vessel wall magnetic resonance imaging at 3.0 Tesla: A reproducibility study of respiratory navigator gated free‐breathing 3D black blood magnetic resonance imaging

The purpose of this study was to evaluate a free‐breathing three‐dimensional (3D) dual inversion‐recovery (DIR) segmented k‐space gradient‐echo (turbo field echo [TFE]) imaging sequence at 3T for the quantification of aortic vessel wall dimensions. The effect of respiratory motion suppression on image quality was tested. Furthermore, the reproducibility of the aortic vessel wall measurements was investigated. Seven healthy subjects underwent 3D DIR TFE imaging of the aortic vessel wall with and without respiratory navigator. Subsequently, this sequence with respiratory navigator was performed twice in 10 healthy subjects to test its reproducibility. The signal‐to‐noise (SNR), contrast‐to‐noise ratio (CNR), vessel wall sharpness, and vessel wall volume (VWV) were assessed. Data were compared using the paired t‐test, and the reproducibility of VWV measurements was evaluated using intraclass correlation coefficients (ICCs). SNR, CNR, and vessel wall sharpness were superior in scans performed with respiratory navigator compared to scans performed without. The ICCs concerning intraobserver, interobserver, and interscan reproducibility were excellent (0.99, 0.94, and 0.95, respectively). In conclusion, respiratory motion suppression substantially improves image quality of 3D DIR TFE imaging of the aortic vessel wall at 3T. Furthermore, this optimized technique with respiratory motion suppression enables assessment of aortic vessel wall dimensions with high reproducibility. Magn Reson Med 61:35–44, 2009. © 2008 Wiley‐Liss, Inc.     

Psychopathie et risque de récidive sexuelle : analyse critique de la littérature scientifique

Objectives

For the past twenty years, sexual violence is a major subject in the legal and criminological fields. Moreover, this phenomenon is becoming a major public health issue and becomes an important topic in termes of prevention. The main objective of this article is to clarify the current state of the litterature about the relationship between the psychopathy and the risk of sexual recidivism. Indeed, the relationship between both of them are debated among the studies right now. So, it's in this context that we wanted to expose the international studies on this topic and to discuss it.

Increase in fecal primary bile acids and dysbiosis in patients with diarrhea-predominant irritable bowel syndrome

Background Irritable bowel syndrome (IBS) is a multifactorial disease for which a dysbiosis of the gut microbiota has been described. Bile acids (BA) could play a role as they are endogenous laxatives and are metabolized by gut microbiota. We compared fecal BA profiles and microbiota in healthy subjects (HS) and patients with diarrhea‐predominant IBS (IBS‐D), and we searched for an association with symptoms. Methods Clinical features and stool samples were collected in IBS‐D patients and HS. Fecal BA profiles were generated using HPLC coupled to tandem mass spectrometry. The fecal microbiota composition was assessed by q‐PCR targeting dominant bacterial groups and species implicated in BA transformation. Key Results Fourteen IBS‐D patients and 18 HS were included. The two groups were comparable in terms of age and sex. The percentage of fecal primary BA was significantly higher in IBS‐D patients than in HS, and it was significantly correlated with stool consistency and frequency. Fecal counts of all bacteria, lactobacillus, coccoides, leptum and Faecalibacterium prausnitzii were similar. There was a significant increase of Escherichia coli and a significant decrease of leptum and bifidobacterium in IBS‐D patients. Conclusions & Inferences We report an increase of primary BA in the feces of IBS‐D patients compared to HS, correlated with stool consistency and frequency. A dysbiosis of different bacterial groups was detected, some of them involved in BA transformation. As the gut microbiota is the exclusive pathway to transform primary into secondary BA, this suggests a functional consequence of dysbiosis, leading to lower BA transformation.     

Depressive symptoms predict long-term mortality after liver transplantation

Objective

Depressive symptoms are common after liver transplantation (LT). We studied whether depressive symptoms affect long-term survival after LT.

Methods

In a prospective cohort study, 134 liver transplant patients were assessed for depressive symptoms using the Beck Depression Inventory—short form (BDI), focusing on the 3 months post-LT score and on the score change from the waiting list period. They were followed up for long-term survival. The median duration of the follow-up period was 43 months post-LT. None of the 134 patients was lost to follow-up for survival.

Results

A total of 33.6% of the LT patients had mild to moderate depressive symptoms 3 months post-LT. Eighteen (13.4%) patients died during the follow-up. Using Cox proportional hazards analysis, depressive symptoms were significantly associated with mortality (hazard ratio [HR] 1.22, 95% confidence interval (CI) 1.07-1.40, P<.003), one more point in the BDI score being associated with a 17% increase in mortality risk. Other predictive factors of mortality were older age and hepatitis C virus with recurrence 3 months post-LT. Similarly, an increase in depressive symptoms between the waiting list and 3 months post-LT periods predicted mortality (HR 1.18, 95% CI 1.01-1.38, P=.03), especially for patients without depressive symptoms on waiting list (HR 1.56, 95% CI 1.16-2.12, P=.004).

Conclusion

Depressive symptoms after LT and an increase in depressive symptoms between the waiting list and post-LT are associated with an increased risk of long-term mortality. Interventions that could reduce depressive symptoms could potentially decrease long-term mortality after LT.