A miniature, moveable electrode for brain stimulation in small animals

A moveable, nonrotating electrode of tiny dimensions for brain stimulation in small animals is described. Its usefulness is demonstrated in a mapping study of circling behavior in mesencephalic areas of the rat.     

Temporal and spatial congruence of components of motion-onset evoked responses investigated by whole-head magneto-electroencephalography

Motion-onset related components in averaged whole head co-recorded MEG and EEG responses of 24 adults to a low-contrast checkerboard pattern were studied. The aims were to identify these components, to characterize quantitatively their maps and to localize the underlying sources by equivalent-current-dipole (ECD) analyses with a spherical head model.After a weak P1, a large start-elicited negativity arises, comprising the novel N2a (occipital positive and parieto-central negative, peak-latency 141 ms) and the N2 like N2b (bilateral parieto-temporal, 175 ms) component. It is followed by a large positive stop-related component, P2 (156 ms after motion-offset). The corresponding MEG components N2am and N2bm showed bilateral dipole fields with considerable overlap. P1m has a single dipole field around the midline. N2a(m) and N2b(m) can be modelled with two bilateral ECDs with significant different locations. The study shows that accurate mapping and ECD analyses can distinguish two neighbouring areas of the visual cortex, 21+/-4 (SE) mm separated, which activities are reflected in both spatio-temporally closely related N2(m) components. N2a(m) and N2b(m) originate in the extrastriate cortex, possibly close to or in V3/V3A and MT/V5 respectively. Motion-evoked activity in (near) V3/V3A is novel on the basis of EEG data.     

Disease susceptibility genes for autism

Autism is a complex neurodevelopmental disorder characterized by impairment in social interaction accompanied by a delay or lack of language, restricted interests, stereotyped behavior, and repetitive movement. Genetic predisposition to autism is evident from family and twin studies, and heritability in idiopathic autism is estimated at over 90%. Frequency of the disorder is approximately 1:2000 with a male to female ratio of 4:1. Affected individuals look normal at birth, and the symptoms manifest at the first 2-3 years of life. The spectrum of clinical symptoms and the severity of the disorder are variable even among siblings. Family studies and several genome-wide linkage analyses support the hypothesis of complex inheritance with involvement of as many as 10-100 genes of moderate effect. Identification of genes responsible for the phenotype would help to understand the molecular mechanisms of the disorder. Several genes have been proposed to play a role in susceptibility to autism, and this paper will overview those genes and their potential role in the disorder.     

多电极网篮状导管标测技术的临床应用

多电极网篮状导管可作心内膜多位点同步标测。结合特定的分析处理软件 ,可对多种复杂心律失常进行标测并指导其消融过程。尤其对于持续时间短或血流动力学不稳定的心律失常有极大的应用价值     

Noninvasive Electrocardiographic Imaging (ECGI): Comparison to intraoperative mapping in patients

OBJECTIVES/BACKGROUND: Cardiac arrhythmias are a leading cause of death and disability. Electrocardiographic imaging (ECGI) is a noninvasive imaging modality that reconstructs potentials, electrograms, and isochrones on the epicardial surface from body surface measurements. We previously demonstrated in animal experiments through comparison with simultaneously measured epicardial data the high accuracy of ECGI in imaging cardiac electrical events. Here, images obtained by noninvasive ECGI are compared to invasive direct epicardial mapping in open heart surgery patients. METHODS: Three patients were studied during sinus rhythm and right ventricular endocardial and epicardial pacing (total of five datasets). Body surface potentials were acquired preoperatively or postoperatively using a 224-electrode vest. Heart-torso geometry was determined preoperatively using computed tomography. Intraoperative mapping was performed with two 100-electrode epicardial patches. RESULTS: Noninvasive potential maps captured epicardial breakthrough sites and reflected general activation and repolarization patterns, localized pacing sites to approximately 1 cm and distinguished between epicardial and endocardial origin of activation. Noninvasively reconstructed electrogram morphologies correlated moderately with their invasive counterparts (cross correlation = 0.72 +/- 0.25 [sinus rhythm], 0.67 +/- 0.23 [endocardial pacing], 0.71 +/- 0.21 [epicardial pacing]). Noninvasive isochrones captured the sites of earliest activation, areas of slow conduction, and the general excitation pattern. CONCLUSIONS: Despite limitations due to nonsimultaneous acquisition of the surgical and noninvasive data under different conditions, the study demonstrates that ECGI can capture important features of cardiac electrical excitation in humans noninvasively during a single beat. It also shows that general excitation patterns and electrogram morphologies are largely preserved in open chest conditions.     

Localization of dopamine receptors in the tree shrew brain using [H]-SCH23390 and [I]-epidepride

The tree shrew is a mammalian species, which is phylogenetically related to insectivores and primates. The aim of the present study was to investigate the distribution of dopamine receptor D1- and D2-like binding sites in the brain of this non-rodent, non-primate mammal. Using in vitro autoradiography and employing the radioligands [³H]-SCH23390 and [¹²⁵I]-epidepride, dopamine receptors were mapped and quantified. Significant findings with regard to the D1-like binding pattern include the presence of a “patchy” binding in the striatum. In the cortex, D1-like binding sites were observed in both the superficial and the deep layers. In the hippocampal formation, D1-like binding sites were seen primarily in the CA1 region and not in the dentate gyrus. These characteristics of the D1 pattern in the tree shrew brain are shared by cat and monkey and human brain, but not by rodent brain. Significant findings with regard to the D2-like binding pattern include the presence of D2-like binding in the claustrum. In addition, the striatum demonstrated “patchy” D2-like binding. These characteristics of the D2 pattern in the tree shrew brain are shared by cat and monkey and human brain, but not by rodent brain. On the other hand, the significant densities of D2-like binding sites in the glomerular layer of the tree shrew olfactory bulb is a finding that discriminates tree shrews from higher evolutionary species who lack such binding. Overall, the evidence coincides with the view that tree shrews are phylogenetically related to primates.     

《实变函数》中p进制的若干应用

概括介绍了p进位制表数法,对《实变函数》课程中涉及到p进位制的若干问题进行了系统的讨论.     

老年期精神分裂症与健康老年人EEG、BEAM对照研究

目的探讨老年期精神分裂症（以下简称试验组）的脑电图（EEG）、脑电地形图（BEAM）变化特点。方法对100例老年期精神分裂症患者,100例健康老年人（对照组）进行脑电图、脑电地形图检查,对比分析评价脑功能状态。结果老年期精神分裂症组EEG异常率明显高于健康老年人组,差异有统计学意义（x2=38．18,P〈0．05）;两组BEAM各极点慢频段（θ、δ）相对功率比较差异有统计学意义,P均〈0．01。结论EEG、BEAM检查对老年期精神分裂症的早期鉴别诊断及评价老年人健康状况具有实用价值。     

SNOMED CT与OpenEHR的整合探究

详细介绍SNOMED CT与OpenEHR的发展历史、主要内容、主要架构,通过数据类型转换、原型中的临床术语与SNOMED CT的映射、候选术语集等方法进行SNOMED CT与OpenEHR的整合,从而使原型中的术语更加规范,也为互操作提供可能。     

Gray matter morphology and the level of functioning in one-year follow-up of first-episode schizophrenia patients

Schizophrenia is a condition with a highly variable course that is hard to predict. The aim of the present study was to investigate if local gray matter volume (GMV) can differentiate poor (PF) and good (GF) functioning patients using voxel-wise analysis in a group of first-episode schizophrenia subjects (FES).