Partial correlation analyses of global diffusion tensor imaging-derived metrics in glioblastoma multiforme: Pilot study

AIM: To determine existing correlates among diffusion tensor imaging(DTI)-derived metrics in healthy brains and brains with glioblastoma multiforme(GBM). METHODS: Case-control study using DTI data from brain magnetic resonance imaging of 34 controls(mean, 41.47; SD, ± 21.94 years; range, 21-80 years) and 27 patients with GBM(mean, SD; 48.41 ± 15.18 years; range, 18-78 years). Image postprocessing using FSL software calculated eleven tensor metrics: fractional(FA) and relative anisotropy; pure isotropic(p) and anisotropic diffusions(q), total magnitude of diffusion(L); linear(Cl), planar(Cp) and spherical tensors(Cs); mean(MD), axial(AD) and radial diffusivities(RD). Partial correlation analyses(controlling the effect of ageand gender) and multivariate Mancova were performed.RESULTS: There was a normal distribution for all metrics. Comparing healthy brains vs brains with GBM, there were significant very strong bivariate correlations only depicted in GBM: [FA?Cl(+)], [FA?q(+)], [p?AD(+)], [AD?MD(+)], and [MD?RD(+)]. Among 56 pairs of bivariate correlations, only seven were significantly different. The diagnosis variable depicted a main effect [F-value(11, 23) = 11.842, P ≤ 0.001], with partial eta squared = 0.850, meaning a large effect size; age showed a similar result. The age also had a significant influence as a covariate [F(11, 23) = 10.523, P < 0.001], with a large effect size(partial eta squared = 0.834).CONCLUSION: DTI-derived metrics depict significant differences between healthy brains and brains with GBM, with specific magnitudes and correlations. This study provides reference data and makes a contribution to decrease the underlying empiricism in the use of DTI parameters in brain imaging.

扩张型心肌病的心血管磁共振成像、纤维化和预后

目的:在一项前瞻性纵向研究中评价室壁中层纤维化对判断扩张型心肌病(DCM)预后的价值。背景:在植入装置时代,对非缺血性DCM患者进行风险分层尚存在问题。近30%的DCM患者经晚期钆增强(LGE)

“病理影像化”:基于组织学特征的磁共振成像在体识别心肌纤维化

Myocardial fibrosis,characterized by the excessive deposition of extracellular matrix proteins,is an important underlying mechanism for adverse outcomes in many cardiovascular diseases[1].Multiple modalities have been developed to identify and quantify myocardial fibrosis non-invasively.Cardiac magnetic resonance(CMR)imaging provides the gold standard for the assessment of cardiac structure and function.

DLST mutations in pheochromocytoma and paraganglioma cause proteome hyposuccinylation andmetabolic remodeling

Dear Editor,Of all human tumors,pheochromocytomas and paragangliomas(PPGLs)have the highest heritability rate.Over 15%of PPGLs harbor mutations in genes encoding tricarboxylic acid(TCA)cycle-related enzymes that cause oncometabolite accumulation and drive tumorigenesis via metabolic adaptation to hypoxia and global hypermethylation[1].The dihydrolipoamide S-succinyltransferase(DLST)gene was recently described as a new PPGL susceptibility gene[2].

Ventral medial prefrontal functional connectivity and emotion regulation in chronic schizophrenia: A pilot study

People with schizophrenia exhibit impaired social cognitive functions, particularly emotion regulation. Abnormal activations of the ventral medial prefrontal cortex （vMPFC） during emotional tasks have been demonstrated in schizophrenia, suggesting its important role in emotion processing in patients. We used the resting-state functional connectivity approach, setting a functionally relevant region, the vMPFC, as a seed region to examine the intrinsic functional interactions and communication between the vMPFC and other brain regions in schizophrenic patients. We found hypo-connectivity between the vMPFC and the medial frontal cortex, right middle temporal lobe （MTL）, right hippocampus, parahippocampal cortex （PHC） and amygdala. Further, there was a decreased strength of the negative connectivity （or anticorrelation） between the vMPFC and the bilateral dorsal lateral prefrontal cortex （DLPFC） and pre-supplementary motor areas. Among these connectivity alterations, reduced vMPFC-DLPFC connectivity was positively correlated with positive symptoms on the Positive and Negative Syndrome Scale, while vMPFC-right MTL/PHC/amygdala functional connectivity was positively correlated with the performance of emotional regulation in patients. These findings imply that communication and coordination throughout the brain networks are disrupted in schizophrenia. The emotional correlates of vMPFC connectivity suggest a role of the hypo-connectivity between these regions in the neuropathology of abnormal social cognition in chronic schizophrenia.

Diffusion tensor imaging-derived measures of fractional anisotropy across the pyramidal tract are influenced by the cerebral hemisphere but not by gender in young healthy volunteers： a split-plot factorial analysis of variance

Background Diffusion tensor imaging （DTI） permits quantitative examination within the pyramidal tract （PT） by measuring fractional anisotropy （FA）. To the best of our knowledge, the inter-variability measures of FA along the PT remain unexplained. A clear understanding of these reference values would help radiologists and neuroscientists to understand normality as well as to detect early pathophysiologic changes of brain diseases. The aim of our study was to calculate the variability of the FA at eleven anatomical landmarks along the PT and the influences of gender and cerebral hemisphere in these measurements in a sample of young, healthy volunteers. Methods A retrospective, cross-sectional study was performed in twenty-three right-handed healthy volunteers who underwent magnetic resonance evaluation of the brain. Mean FA values from eleven anatomical landmarks across the PT （at centrum semiovale, corona radiata, posterior limb of internal capsule （PLIC）, mesencephalon, pons, and medulla oblongata） were evaluated using split-plot factorial analysis of variance （ANOVA）. Results We found a significant interaction effect between anatomical landmark and cerebral hemisphere （F （10, 32）=4.516, P=0.001; Wilks＇ Lambda 0.415, with a large effect size （partial η2=0.585））. The influence of gender and age was non-significant. On average, the midbrain and PLIC FA values were higher than pons and medulla oblongata values; centrum semiovale measurements were higher than those of the corona radiata but lower than PLIC. Conclusions There is a normal variability of FA measurements along PT in healthy individuals, which is influenced by regions of interest location （anatomical landmarks） and cerebral hemisphere. FA measurements should be reported for comparing same-side and same-landmark PT to help avoid comparisons with the contralateral PT; ideally, normative values should exist for a clinically significant age group. A standardized package of selected DTI processing tools would allow DTI processing to be routinely performed in clinical settings.

Cancer Cell：癌细胞如何在没有葡萄糖的条件下继续增殖扩张？

肿瘤细胞最主要的目标就是生存，其甚至不惜破坏其所依附的有机体的健康也要达到生存的目的；为了生存肿瘤细胞会练就许多健康细胞没有的本领，包括在葡萄糖水平极低的情况下继续保持生长势头，而这或许就是常用的抗血管生成因子难以消除癌症的主要原因，肿瘤细胞通常会通过妨碍提供常规的营养物质和葡萄糖的血管的发育来影响机体健康，