Very preterm adolescents show gender-dependent alteration of the structural brain correlates of spelling abilities

Individuals born very preterm (VPT) are at risk of neurodevelopmental damage and of adverse educational outcomes in childhood and adolescence. The present study used voxel-based morphometry to investigate the association between grey matter and white matter volume and measures of language and executive functioning in VPT born adolescents and term-born controls by gender. VPT individuals (N = 218) and controls (N = 127) underwent neuropsychological assessment and MRI at age 14-15 as part of a longitudinal study. Differential associations were found between spelling scores and frontal regional grey matter volume when group (VPT and control) and gender (males and females) were investigated. A main effect of group demonstrated a weaker association in VPT adolescents relative to controls between grey matter volume in the left medial and right superior frontal gyri and spelling scores. A main effect of gender revealed spelling scores to be correlated with grey matter volume in the right superior frontal gyrus in females to a greater extent than in males. Furthermore, a significant interaction between group and gender was detected in two regions. Spelling scores showed a stronger association with grey matter volume in a cluster with local maxima in the left medial frontal cortex extending to the caudate nucleus in VPT females than in control females and a weaker association in VPT males compared to control males. In addition, spelling scores showed a stronger association with grey matter volume in left middle frontal gyrus in VPT males compared to control males and a weaker association in VPT females than in control females. When group and gender were investigated, there were no statistically different correlations between structural brain volumes and performance on reading and executive function tests. These data demonstrate that the typical structure-function relationship in respect to spelling abilities appears to be altered in individuals born preterm and the processes underpinning this divergence may be subject to gender-specific influences.     

Elevated numbers and altered subsets of procoagulant microparticles in breast cancer patients using endocrine therapy

Introduction

Microparticles (MP) can be elevated in cancer and thromboembolic disease. We hypothesized a role for MP in the hypercoagulable state in breast cancer patients using endocrine therapy, in whom both cancer and the use of endocrine therapy are independent risk factors for the development of thrombosis.

Design and methods

Plasma samples were collected from 40 breast cancer patients using endocrine therapy (20 patients without metastases receiving adjuvant therapy and 20 patients with metastatic disease treated in a palliative setting) and from 20 female healthy controls. The endocrine therapy used was either an anti-estrogen or an aromatase inhibitor. Numbers and cellular origin of MP subsets were analyzed by flowcytometry. MP-associated procoagulant activity was measured using a thrombin generation assay using conditions that allow analysis of MP induced thrombin generation.

Results

Breast cancer patients using endocrine therapy had higher levels of MP positive for Annexin V (median 10000 vs 6500 × 10E6/l), P-selectin (330 vs 200 × 10E6/l), tissue factor (33 vs 15 × 10E6/l), and of MP derived from platelets (CD41) and leukocytes (CD45). Thrombin generation in plasma was dependent on the presence of MP and thrombin generation performed after addition of isolated MP to normal plasma showed a higher endogenous thrombin potential (1105 vs 1029 nM.min) in breast cancer patients. No differences were observed in MP levels and thrombin generation parameters between the metastatic and adjuvant group.

Conclusion

Breast cancer patients using endocrine therapy have an increased MP number and a higher MP-dependent thrombin generation, irrespective of the presence of metastatic disease. Altered MP subset characteristics in these patients, especially the higher number of (activated) platelet derived MP and leukocyte derived MP, may in part explain a heightened procoagulant state in breast cancer patients using endocrine therapy.     

Insights into genotype-phenotype correlations in spinal muscular atrophy: a retrospective study of 103 patients

Spinal muscular atrophy (SMA) is an autosomal recessive disorder associated with homozygous deletion of the survival motor neuron 1 gene (SMN1). Its centromeric copy gene, SMN2, is the major modifying factor. However, the genotype-phenotype correlation is incomplete and is therefore not useful in clinical practice. We studied a cohort of 103 patients in order to refine this correlation. In addition to standard disease severity data, we collected three additional criteria: age at death; brainstem involvement; and loss of ambulation. Gene dosage analysis was conducted by multiplex ligation-dependent probe amplification (MLPA). SMN2 copynumber was highly correlated with survival duration in SMA type I and ambulation conservation or loss in type III. Among SMA severity groups, it was not significantly different in cases with brainstem involvement. Although the SMN2 copynumber could provide prognostic indications, clinical discrepancies still exist among patients, suggesting the existence of unidentified modifying factors.     

Responses of gut microbiota and glucose and lipid metabolism to prebiotics in genetic obese and diet-induced leptin-resistant mice

OBJECTIVE

To investigate deep and comprehensive analysis of gut microbial communities and biological parameters after prebiotic administration in obese and diabetic mice.

RESEARCH DESIGN AND METHODS

Genetic (ob/ob) or diet-induced obese and diabetic mice were chronically fed with prebiotic-enriched diet or with a control diet. Extensive gut microbiota analyses, including quantitative PCR, pyrosequencing of the 16S rRNA, and phylogenetic microarrays, were performed in ob/ob mice. The impact of gut microbiota modulation on leptin sensitivity was investigated in diet-induced leptin-resistant mice. Metabolic parameters, gene expression, glucose homeostasis, and enteroendocrine-related L-cell function were documented in both models.

RESULTS

In ob/ob mice, prebiotic feeding decreased Firmicutes and increased Bacteroidetes phyla, but also changed 102 distinct taxa, 16 of which displayed a >10-fold change in abundance. In addition, prebiotics improved glucose tolerance, increased L-cell number and associated parameters (intestinal proglucagon mRNA expression and plasma glucagon-like peptide-1 levels), and reduced fat-mass development, oxidative stress, and low-grade inflammation. In high fat–fed mice, prebiotic treatment improved leptin sensitivity as well as metabolic parameters.

CONCLUSIONS

We conclude that specific gut microbiota modulation improves glucose homeostasis, leptin sensitivity, and target enteroendocrine cell activity in obese and diabetic mice. By profiling the gut microbiota, we identified a catalog of putative bacterial targets that may affect host metabolism in obesity and diabetes.Obesity and related metabolic disorders are closely associated with a low-grade inflammatory state (1). Growing evidence also demonstrates that the gut microbiota plays a critical role in the development of obesity, type 2 diabetes, and insulin resistance (2–9). Given that the total number of bacteria in the gut is estimated at ∼10¹⁴, it has been proposed that the genome size of this exteriorized organ largely exceeds the human genome size (10,11). However, the composition of the gut microbiota and the exact role of microorganisms present in the gut remain poorly defined. Nonetheless, advances in metagenomic methods for characterizing microbial diversity have helped to evaluate the functional contribution of this large collection of microbes to host metabolism (12). For instance, recent evidence suggests that changes in gut microbiota composition may play a critical role in the development of obesity-associated inflammation (7,8,13,14). Accordingly, obesity-associated, low-grade inflammation may be related to the gut microbiota by mechanisms involving bacterially derived lipopolysaccharide (LPS) (6–8,14–16).In light of these recent findings, understanding the role of microbial communities and identifying molecular targets related to metabolism regulation are of the utmost importance. Addressing these issues is challenging because of the lack of well-characterized models. Nevertheless, germ-free animals have led to striking and unequivocal findings regarding the role of gut microbiota in host energy metabolism (3,17,18). In addition to these highly specific models, approaches that are more generously applicable, including prebiotic-induced modulation of the gut microbiota, have been developed and widely used. Prebiotics are nondigestible carbohydrates that beneficially affect host health by selectively stimulating the growth and/or activity of a limited number of bacteria (e.g., bifidobacteria and lactobacilli) (19). We have previously shown that prebiotics improve gut barrier function and alleviate inflammation and insulin resistance associated with obesity by increasing the release of gut hormones, such as glucagon-like peptide 1 and 2 (GLP-1 and GLP-2), and by modulating the endocannabinoid system (8,15,20). Although the beneficial effects of prebiotics have been linked to a concomitant effect on Bifidobacteriaceae, no clear causal relationship has been established between this family and their beneficial metabolic effects (15,21). Thus, to obtain a more deterministic analysis of the gut microbiota, we combined multiple molecular methods, including quantitative PCR (qPCR), barcoded pyrosequencing, and phylogenetic microarrays of 16S rRNA, to generate comprehensive microbial community profiles of obese mice with or without prebiotics in their diet. Furthermore, we identified novel mechanisms by which prebiotics change obesity-associated metabolic disorders in both genetic and diet-induced leptin-resistant mice.