Selecting relevant electrode positions for classification tasks based on the electro-encephalogram

The aim is to describe a general approach to determining important electrode positions when measured electro-encephalogram signals are used for classification. The approach is exemplified in the frame of the brain-computer interface, which crucially depends on the classification of different brain states. To classify two brain states, e.g. planning of movement of right and left index fingers, three different approaches are compared: classification using a physiologically motivated set of four electrodes, a set determined by principal component analysis and electrodes determined by spatial pattern analysis. Spatial pattern analysis enhances the classification rate significantly from 61.3±1.8% (with four electrodes) to 71.8±1.4%, whereas the classification rate using principal component analysis is significantly lower (65.2±1.4%). Most of the 61 electrodes used have no influence on the classification rate, so that, in future experiments, the setup can be simplified drastically to six to eight electrodes without loss of information.     

基于脑电复杂度的意识任务的特征提取与分类

本研究提出了利用事件相关脑电复杂度提取大脑运动意识特征，应用Mahalanobis距离判别式分析法，对人脑想象左右手运动任务进行分类，获得了满意的结果。对受试者想象左右手运动期间在大脑初级感觉运动皮层区记录的脑电信号采用复杂度分析方法量化了事件相关去同步（ERD）和事件相关同步（ERS）时程，结果表明EEG复杂度特征较好反映了ERD／ERS变化时程。最后对测试数据进行分类，最大分类正确率达到86．43％，通过最大分类正确率，最大信噪比，最大互信息等评价指标比较，验证了该方法的有效性，从而为大脑运动意识任务的特征提取及分类提供了新思路。     

基于ERD/ERS脑电信号的智能化功能电刺激系统的设计

设计一套基于事件相关同步电位(Event related desynchron ization,ERD)和事件相关去同步电位(Event related synchronization,ERS)脑电信号反馈控制功能电刺激仪系统。当大脑想象残肢运动中,出现ERD/ERS脑电信号,经过特征提取和特征分类转换为控制命令去触发功能电刺激系统,实现对相应残肢的电刺激。实验结果成功实现了对残肢的电刺激。     

Different pulmonary adenocarcinoma growth patterns significantly affect survival

ObjectiveAdenocarcinoma (AC) is the number one pathological entity of lung cancer with approximately 30–40% of cases. It is known to be heterogeneous and has 5 histopathological growth patterns. We evaluated the long-term survival rates of patients with predominant subtypes.Methods290 patients with AC underwent pulmonary resection between 2012 and 2017 at our institution. We excluded all patients with lymph node involvement and distant metastases. Hence, 163 patients were included for further analysis. Predominant growth pattern was defined if more than 10% of cells showed a growth pattern. 1, 3, and 5-year survival rates were evaluated. Survival was assessed by Kaplan-Meier curves and the Cox proportional hazards model was used to identify prognostic factors for overall survival.ResultsPredominant growth patterns >10% were compared to <10% growth patterns of the same subtype. 1-year, 3-year, and 5-year overall survival rates of patients with predominant solid tumor growth >10% differed significantly from patients with <10% (88.4% vs. 97.6%, p = 0.04; 65.8% vs. 87.4% p = 0.001, 36.4% vs. 65.9% p = 0.01). Survival rates did not differ between >10% papillary and acinar growth compared to <10%. Kaplan-Meier curves showed reduced overall survival for patients with solid tumor growth >10% (log-rank 0.002). Solid tumor growth >10% was an independent prognostic factor for worse long-term survival (Hazard ratio: 3.05, p = 0.01).ConclusionOur study demonstrates that the presence of a predominant solid pattern in pulmonary adenocarcinoma is a factor for an unfavorable prognosis. This should be kept in mind in daily clinical practice.     

The role of hypothalamic estrogen receptors in metabolic regulation

Estrogens regulate key features of metabolism, including food intake, body weight, energy expenditure, insulin sensitivity, leptin sensitivity, and body fat distribution. There are two ‘classical’ estrogen receptors (ERs): estrogen receptor alpha (ERS1) and estrogen receptor beta (ERS2). Human and murine data indicate ERS1 contributes to metabolic regulation more so than ESR2. For example, there are human inactivating mutations of ERS1 which recapitulate aspects of the metabolic syndrome in both men and women. Much of our understanding of the metabolic roles of ERS1 was initially uncovered in estrogen receptor α-null mice (ERS1^−/−); these mice display aspects of the metabolic syndrome, including increased body weight, increased visceral fat deposition and dysregulated glucose intolerance. Recent data further implicate ERS1 in specific tissues and neuronal populations as being critical for regulating food intake, energy expenditure, body fat distribution and adipose tissue function. This review will focus predominantly on the role of hypothalamic ERs and their critical role in regulating all aspects of energy homeostasis and metabolism.     

Association of HTR2A-1438G/A Genetic Polymorphism With Smoking and Chronic Obstructive Pulmonary Disease

Introduction

Cigarette smoking is a major risk factor in the development of chronic obstructive pulmonary disease (COPD). Serotonin levels have been associated with COPD and smoking has been as a significant modulator. Elevated levels of serotonin are responsible for bronchoconstriction and pulmonary vasoconstriction and also nicotine dependence, thus serotonin response could be affected by genetic polymorphisms in transporters and receptors of serotonin.

Cortical network dysfunction revealed by magnetoencephalography in carriers of spinocerebellar ataxia 1 or 2 mutation

ObjectiveIn patients with spinocerebellar ataxia type 1 or 2 (SCA1 or SCA2) and in their asymptomatic gene-positive relatives (AsyRs) we investigated the event-related desynchronization and synchronisation (ERD/ERS) on magnetoencephalographic signals to assess the changes occurring before manifest ataxia, by comparing the results obtained in AsyRs and in their gene-negative healthy relatives (HRs).MethodsTwenty-four patients (12 SCA1, 12 SCA2), 24 AsyRs (13 SCA1, 11 SCA2) and 17 HRs performed a visually cued Go/No-go task. We evaluated the ERD/ERS in regions of interest corresponding to the frontal, central and parietal cortices.ResultsIn the SCA patients the main findings were a loss of side predominance for alpha and beta ERD and significantly weakened beta ERS. In AsyRs the main finding was a significantly enhanced alpha ERD, namely in those who were approaching the estimated time of symptom onset.ConclusionsIn ataxic patients, the loss of ERD lateralisation and the significantly reduction of beta ERS suggest defective bilateral processes that are involved in ending the movement. In AsyRs, enhanced alpha ERD proposes the presence of preclinical marker closely preceding symptom onset.SignificanceMovement-related ERD/ERS can detect the defective sensorimotor integration in ataxic patients, and reveals possible compensatory mechanisms in their AsyRs.     

Relationship between 18F-FDG PET/CT Semi-Quantitative Parameters and International Association for the Study of Lung Cancer,American Thoracic Society/European Respiratory Society Classification in Lung Adenocarcinomas

ObjectiveTo investigate the relationship between ¹⁸F-FDG PET/CT semi-quantitative parameters and the International Association for the Study of Lung Cancer, American Thoracic Society/European Respiratory Society (IASLC/ATS/ERS) histopathologic classification, including histological subtypes, proliferation activity, and somatic mutations.Materials and MethodsThis retrospective study included 419 patients (150 males, 269 females; median age, 59.0 years; age range, 23.0–84.0 years) who had undergone surgical removal of stage IA–IIIA lung adenocarcinoma and had preoperative PET/CT data of lung tumors. The maximum standardized uptake values (SUVmax), background-subtracted volume (BSV), and background-subtracted lesion activity (BSL) derived from PET/CT were measured. The IASLC/ATS/ERS subtypes, Ki67 score, and epidermal growth factor/anaplastic lymphoma kinase (EGFR/ALK) mutation status were evaluated. The PET/CT semi-quantitative parameters were compared between the tumor subtypes using the Mann–Whitney U test or the Kruskal–Wallis test. The optimum cutoff values of the PET/CT semi-quantitative parameters for distinguishing the IASLC/ATS/ERS subtypes were calculated using receiver operating characteristic curve analysis. The correlation between the PET/CT semi-quantitative parameters and pathological parameters was analyzed using Spearman’s correlation. Statistical significance was set at p < 0.05.ResultsSUVmax, BSV, and BSL values were significantly higher in invasive adenocarcinoma (IA) than in minimally IA (MIA), and the values were higher in MIA than in adenocarcinoma in situ (AIS) (all p < 0.05). Remarkably, an SUVmax of 0.90 and a BSL of 3.62 were shown to be the optimal cutoff values for differentiating MIA from AIS, manifesting as pure ground-glass nodules with 100% sensitivity and specificity. Metabolic-volumetric parameters (BSV and BSL) were better potential independent factors than metabolic parameters (SUVmax) in differentiating growth patterns. SUVmax and BSL, rather than BSV, were strongly or moderately correlated with Ki67 in most subtypes, except for the micropapillary and solid predominant groups. PET/CT parameters were not correlated with EGFR/ALK mutation status.ConclusionAs noninvasive surrogates, preoperative PET/CT semi-quantitative parameters could imply IASLC/ATS/ERS subtypes and Ki67 index and thus may contribute to improved management of precise surgery and postoperative adjuvant therapy.