Functional brain imaging in the clinical assessment of consciousness

Recent findings suggest that functional brain imaging might be used to identify consciousness in patients diagnosed with persistent vegetative state and minimally conscious state. Michael Rafii and James Brewer discuss the potential for fMRI's wider implementation in clinical practice, and associated caveats.     

Memory,consciousness and neuroimaging.

Neuroimaging techniques that allow the assessment of memory performance in healthy human volunteers while simultaneously obtaining measurements of brain activity in vivo may offer new information on the neural correlates of particular forms of memory retrieval and their association with consciousness and intention. We consider evidence from studies with positron emission tomography and functional magnetic resonance imaging indicating that priming, a form of implicit retrieval, is associated with decreased activity in various cortical regions. We also consider evidence concerning the question of whether two components of explicit retrieval--intentional or effortful search and successful conscious recollection--are preferentially associated with increased activity in prefrontal and medial temporal regions, respectively. Last, we consider recent efforts to probe the relation between the phenomenological character of remembering and neural activity. In this instance we broaden our scope to include studies employing event-related potentials and consider evidence concerning the neural correlates of qualitatively different forms of memory, including memory that is specifically associated with a sense of self, and the recollection of particular temporal or perceptual features that might contribute to a rich and vivid experience of the past.     

Recovering the contents of consciousness in the noise of neuroimaging

A classical approach in the neurosciences is to study neural activity modulations induced by a stimulus, a task, etc. This approach is anchored in a behaviourist culture and has proven informative within certain limits. The present paper shows that this approach nonetheless neglects aspects of neural activity that can also contribute important information about brain function. Over the last years, the contributions with the strongest impact on progress in cognitive neuroscience have used other approaches that exploit a spatial or temporal variability of neural activity that standard analyses consider as noise and hence do not take into account. By applying multi-variate analyses, spatial variability of evoked responses has permitted decoding sensory and cognitive representations in the brain. Temporal variability of ongoing neural activity influences how stimuli are perceived trial by trial as well as the associated evoked responses which points out the importance of spontaneous brain activity for cognition. We describe these two kind of approaches based on experiments using functional neuroimaging but the conclusions generalize to other techniques applied in the neurosciences.     

Neurodegeneration with brain iron accumulation - clinical syndromes and neuroimaging

Iron participates in a wide array of cellular functions and is essential for normal neural development and physiology. However, if inappropriately managed, the transition metal is capable of generating neurotoxic reactive oxygen species. A number of hereditary conditions perturb body iron homeostasis and some, collectively referred to as neurodegeneration with brain iron accumulation (NBIA), promote pathological deposition of the metal predominantly or exclusively within the central nervous system (CNS). In this article, we discuss seven NBIA disorders with emphasis on the clinical syndromes and neuroimaging. The latter primarily entails magnetic resonance scanning using iron-sensitive sequences. The conditions considered are Friedreich ataxia (FA), pantothenate kinase 2-associated neurodegeneration (PKAN), PLA2G6-associated neurodegeneration (PLAN), FA2H-associated neurodegeneration (FAHN), Kufor-Rakeb disease (KRD), aceruloplasminemia, and neuroferritinopathy. An approach to differential diagnosis and the status of iron chelation therapy for several of these entities are presented. This article is part of a Special Issue entitled: Imaging Brain Aging and Neurodegenerative disease.     

昆虫病原线虫资源概况和分类技术进展

昆虫病原线虫是具有重要潜在应用价值的害虫生物防治资源,主要包括斯氏线虫科（Steinernematidae）的斯氏线虫属Steinernema与新斯氏线虫属Neosteinernema线虫和异小杆线虫科（Heterorhabditidae）的异小杆线虫属Heterorhabditis线虫。近10年来,分子生物学方法与传统的形态学方法相结合应用到线虫的鉴定与分类,昆虫病原线虫的分类进入稳定与发展时期,越来越多的新种或品系被发现及应用于生物防治。目前已描述的昆虫病原线虫种类达65种,其中斯氏线虫属52种,新斯氏线虫属1种,异小杆线虫属12种。本文整理列出了迄今报道的昆虫病原线虫种类及其来源,并综述了昆虫病原线虫分类现状以及鉴定与分类方法上的研究进展,重点阐述了分子生物学技术在昆虫病原线虫鉴定与分类的应用状况。     

细胞电生理技术在昆虫抗药性研究中的应用

害虫几乎对所有化学农药及Bt等生物农药都产生了抗性。离子通道是多种杀虫剂的作用靶,因此作为研究离子通道基本手段的电压钳与膜片钳技术在害虫抗性检测与抗性机理研究中越来越受到重视。该文综述了细胞电生理技术在害虫抗性机理、杀虫剂作用机理以及药物筛选中的应用。     

蛋白质相互作用实验技术的最新进展

蛋白质相互作用的研究, 是揭示生物体正常生长发育及其应对各种生物或(和)非生物胁迫的分子机制及其调控网络的重要途径。文章综述了近年来发展起来的研究蛋白质相互作用的常用实验性方法, 如酵母双杂交系统、串联亲和纯化、免疫共沉淀、GST Pull-down、双分子荧光互补、荧光共振能量转移、表面等离子共振分析, 介绍了其原理、发展进程, 并分析了其优缺点。     

杂交酶及其相关技术研究进展

根据杂交酶研究目的以及构建杂交酶方法,文中总结近年来杂交酶研究的成果,将杂交酶的应用分为以下几个主要的方面改变酶的非催化特性;创造新活性的酶;研究蛋白质的结构和功能的关系等.还介绍了DNA序列改组、表达克隆、分子筛选、人造细胞样区室筛选基因等技术的进展以及这些技术在构建杂交酶方面的应用.     

Advances in nonlinear optical microscopy techniques for in vivo and in vitro neuroimaging

Understanding the mechanism of the brain via optical microscopy is one of the challenges in neuroimaging, considering the complex structures. Advanced neuroimaging techniques provide a more comprehensive insight into patho-mechanisms of brain disorders, which is useful in the early diagnosis of the pathological and physiological changes associated with various neurodegenerative diseases. Recent advances in optical microscopy techniques have evolved powerful tools to overcome scattering of light and provide improved in vivo neuroimaging with sub-cellular resolution, endogenous contrast specificity, pinhole less optical sectioning capability, high penetration depth, and so on. The following article reviews the developments in various optical imaging techniques including two-photon and three-photon fluorescence, second-harmonic generation, third-harmonic generation, coherent anti-Stokes Raman scattering, and stimulated Raman scattering in neuroimaging. We have outlined the potentials and drawbacks of these techniques and their possible applications in the investigation of neurodegenerative diseases.     

Role of advances in chromatographic techniques in phytochemistry

Chromatography is the lynchpin of phytochemistry and is the key to obtaining pure compounds for structure elucidation, for pharmacological testing or for development into therapeuticals. It also plays a fundamental role as an analytical technique for quality control and standardisation of phytotherapeuticals. Although liquid chromatography is barely 100 years old, an extraordinary variety of instrumental and ancillary equipment is available, notably in the domain of high-performance liquid chromatography. It is impossible to touch all areas of chromatography in such a review but certain areas are worthy of mention: HPLC, HPTLC, UPLC and countercurrent chromatography. Another important addition has been the development of hyphenated techniques involving HPLC: LC/UV, LC/MS, LC/MS(n) and LC/NMR. These are indispensable nowadays for the early detection and identification of compounds in crude plant extracts.     

海洋微生物多样性研究技术进展

海洋微生物资源丰富,开发潜力巨大,综述了稀释培养、高通量培养、扩散盒培养和微囊包埋等新的海洋微生物可培养技术的发展,重点阐述了基于现代分子技术的PCR、DGGE/TGGE、gyrB基因、基因芯片、环境基因组学和质谱等方法在未培养海洋微生物多样性研究中的应用。通过上述研究技术和方法的创新,人类开发海洋微生物资源进入一个崭新的时代。     

Combined electrophysiological assessment of the visual system in central serous retinopathy

Six subjects suffering from idiopathic central serous retinopathy were examined during the acute phase using a battery of neurophysiological tests. The records (using skin electrodes) included the electro-oculogram (EOG), the white light electroretinogram (ERG) during various stages of dark and light adaptation, and the flash and pattern reversal visual evoked potentials. Results obtained from the affected eye were compared with those from the healthy eye. The values of the healthy eye were not significantly different from our normal control group.The EOGs of the affected eyes were not significantly different from those of the healthy eyes. The ‘a’ wave of the ERG during light adaptation was significantly (P<0.05) smaller in the affected eye. The amplitudes of the other components and the latencies of all components were not affected. The latency of the PR-VEP of the affected eye in all subjects was prolonged in comparison with the unaffected eye. In 3 subjects the latency was prolonged by more than 2 S.D.s compared with our control group. The amplitude of the PR-VEP in 5 of our 6 subjects was slightly but significantly (P<0.02) smaller in the affected eye. There was no correlation between amplitude and latency changes.     

Recent advances in gel-based proteome profiling techniques

This review focuses on recent developments in gel-based proteomics techniques. By combining traditional sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and two-dimensional gel electrophoretic techniques with recent advances in protein labeling using different classes of molecules (i.e., fluorescent dyes, chemical probes, radioisotopes), new technologies have been developed that allow for high-throughput studies of proteins at the whole-proteome scale.     

Dysfunction of the prefrontal cortex in addiction: neuroimaging findings and clinical implications

The loss of control over drug intake that occurs in addiction was initially believed to result from disruption of subcortical reward circuits. However, imaging studies in addictive behaviours have identified a key involvement of the prefrontal cortex (PFC) both through its regulation of limbic reward regions and its involvement in higher-order executive function (for example, self-control, salience attribution and awareness). This Review focuses on functional neuroimaging studies conducted in the past decade that have expanded our understanding of the involvement of the PFC in drug addiction. Disruption of the PFC in addiction underlies not only compulsive drug taking but also accounts for the disadvantageous behaviours that are associated with addiction and the erosion of free will.     

Anesthesiology-important advances in clinical medicine: outpatient anesthesia techniques: continuous intravenous infusion of anesthetic agents

The Scientific Board of the California Medical Association presents the following inventory of items of progress in anesthesiology. Each item, in the judgment of a panel of knowledgeable physicians, has recently become reasonably firmly established, both as to scientific fact and important clinical significance. The items are presented in simple epitome and an authoritative reference, both to the item itself and to the subject as a whole, is generally given for those who may be unfamiliar with a particular item. The purpose is to assist practitioners, students, research workers or scholars to stay abreast of these items of progress in anesthesiology that have recently achieved a substantial degree of authoritative acceptance, whether in their own field of special interest or another.The items of progress listed below were selected by the Advisory Panel to the Section on Anesthesiology of the California Medical Association and the summaries were prepared under its direction.