失匹配正波一视觉失匹配电位研究

目的探讨视觉模式中是否存在与听觉失匹配负波（MMN）类似的电位成分。方法采用多导脑电诱发电位工作站对15名健康成人进行事件相关电位研究。采用4种刺激对：无差异（Nd）、轮廓差异（Cd）、形状差异（Sd）和双重差异（Dd），让受试者随机完成形状匹配作业和双重匹配作业。结果在P1-N1潜伏期内（100～140ms），有差异的3种状态（Cd、Sd和Dd）均诱发出一正波，即视觉失匹配正波（MMP），而Dd状态诱发的MMP波幅更大，是单特征差异（Cd、Sd）的MMP之和。结论视觉模式中，偏差刺激诱发的MMP可能是与听觉MMN类似的成分，反映了脑对视觉刺激变化的自动加工过程。     

Component Size Mismatch of Metal on Metal Hip Arthroplasty: An Avoidable Never Event

Size mismatch of components used in total hip arthroplasty is a serious, preventable patient safety incident of unknown prevalence as many cases are not detected. Component size mismatch was found in 11 cases (0.9%) at our retrieval centre. All cases of mismatch were not detected on plain radiograph during routine clinical follow up and blood metal ion levels were elevated above the MHRA action level of 7 ppb. Root cause analysis identified manufacturer, hospital and surgeon factors that need to be addressed to reduce the incidence of this avoidable clinical problem. Retrieval analysis is the only method of confirming size mismatch and is likely to be under-represented in National Joint Registries that record the indication for revision at the time of revision.     

A bias‐free two‐alternative forced choice procedure to examine intersensory illusions applied to the ventriloquist effect by flashes and averted eye‐gazes

We compared with a new psychophysical method whether flashes and averted eye‐gazes of a cartoon face induce a ventriloquist illusion (an illusory shift of the apparent location of a sound by a visual distracter). With standard psychophysical procedures that measure a direct ventriloquist effect and a ventriloquist aftereffect, we found in human subjects that both types of stimuli induced an illusory shift of sound location. These traditional methods, though, are probably contaminated by response strategies. We therefore developed a new two‐alternative forced choice procedure that allows measuring the strength of an intersensory illusion in a bias‐free way. With this new procedure we found that only flashes, but not averted eye‐gazes, induced an illusory shift in sound location. This difference between flashes and eye‐gazes was validated in an EEG study in which again only flashes illusorily shifted the apparent location of a sound thereby evoking a mismatch negativity response. These results are important because they highlight that commonly used measures of multisensory illusions are contaminated while there is an easy yet stringent way to measure the strength of an illusion in a bias‐free way.     

Differential Influence of Age on the Relationship between Genetic Mismatch and A(H1N1)pdm09 Vaccine Effectiveness

Assessment of influenza vaccine effectiveness (VE) and identification of relevant influencing factors are the current priorities for optimizing vaccines to reduce the impacts of influenza. To date, how the difference between epidemic strains and vaccine strains at genetic scale affects age-specific vaccine performance remains ambiguous. This study investigated the association between genetic mismatch on hemagglutinin and neuraminidase genes and A(H1N1)pdm09 VE in different age groups with a novel computational approach. We found significant linear relationships between VE and genetic mismatch in children, young adults, and middle-aged adults. In the children’s group, each 3-key amino acid mutation was associated with an average of 10% decrease in vaccine effectiveness in a given epidemic season, and genetic mismatch exerted no influence on VE for the elderly group. We demonstrated that present vaccines were most effective for children, while protection for the elderly was reduced and indifferent to vaccine component updates. Modeling such relationships is practical to inform timely evaluation of VE in different groups of populations during mass vaccination and may inform age-specific vaccination regimens.     

Pre-Dilatation Versus No Pre-Dilatation for Implantation of a Self-Expanding Valve in All Comers Undergoing TAVR: The DIRECT Trial

Objectives

The aim of this study was to compare the implantation of a self-expanding valve with or without balloon aortic valvuloplasty (BAV) in an open-label, noninferiority, randomized trial.

DNA microsatellite instability and mismatch repair protein loss in adenomas presenting in hereditary non-polyposis colorectal cancer

BACKGROUND AND AIM: Hereditary non-polyposis colorectal cancer (HNPCC), as its name implies, is associated with few adenomas, and the early evolution of colorectal neoplasia is poorly understood. In this study our aim was to clarify the genetic profiles of benign polyps in subjects with HNPCC using a combined molecular and immunohistochemical approach. METHODS: Thirty adenomas and 17 hyperplastic polyps were obtained from 24 affected HNPCC subjects. DNA was extracted from paraffin embedded tissue by microdissection and analysed for the presence of microsatellite instability (MSI) and mutations in five genes known to be targets in mismatch repair deficiency (TGFbetaRII, IGF2R, BAX, hMSH3, and hMSH6). Serial sections were stained by immunohistochemistry for hMLH1 and hMSH2. RESULTS: Twenty four (80%) of 30 adenomas showed MSI. Of MSI positive adenomas, 66.7% showed MSI at more than 40% of markers (high level of MSI (MSI-H)). Two of 17 hyperplastic polyps revealed MSI at one marker (low level of MSI (MSI-L)). A significant association was found between MSI-H and high grade dysplasia in adenomas (p=0.004). Eight of nine adenomas with mutations of coding sequences revealed high grade dysplasia and all nine were MSI-H. Four of the nine ranged in size from 2 to 5 mm. The presence of the hMSH6 mutation was significantly correlated with high levels of MSI (80% of markers) (p<0.02). Twenty four adenomas gave evaluable results with immunohistochemistry. One of six (17%) microsatellite stable, six of seven (86%) MSI-L, and 11 of 11 (100%) MSI-H adenomas showed loss of either hMLH1 or hMSH2. CONCLUSIONS: Most adenomas in subjects with a definite diagnosis of HNPCC show MSI (80%). The finding of MSI-L is usually associated with loss of expression of hMLH1 or hMSH2, unlike the situation in MSI-L sporadic colorectal cancer. The transition from MSI-L to MSI-H correlated with the finding of high grade dysplasia and mutation of coding sequences and may be driven by mutation of secondary mutators such as hMSH3 and hMSH6. Advanced genetic changes may be present in adenomas of minute size.     

注意缺陷多动障碍儿童哌醋甲酯治疗前后错误监控功能的动态观察

目的探讨注意缺陷多动障碍儿童的错误相关负电位（error-related negativity,ERN）变化与治疗的关系。方法应用德国Brain Products公司的ERP记录与分析系统,对38例ADHD和30名健康儿童作了ERN检测。结果（1）注意缺陷多动障碍组的正确反应率明显低于健康儿童组,正确反应和错误反应的反应时明显比健康儿童组长。（2）与健康儿童组相比,注意缺陷多动障碍ERN潜伏期在Cz、Oz、C3和C4上明显延迟,波幅（Cz、C3、Oz、Pz）较健康儿童组低。（3）患者组在治疗后6月、18月随访时,ERN潜伏期和波幅差异无显著性（P〉0．05）。结论注意缺陷多动障碍儿童的ERN潜伏期和波幅异常,可能反映了本组儿童内在错误监控机制存在缺陷。随访ERN变化可能是一种属性标志。     

Effect of maturation on suprasegmental speech processing in full- and preterm infants: A mismatch negativity study

Infants born prematurely are at higher risk for later linguistic deficits present in delayed or atypical processing of phonetic and prosodic information. In order to be able to specify the nature of this atypical development, it is important to investigate the role of early experience in language perception. According to the concept of Gonzalez-Gomez and Nazzi (2012) there is a special intrauterine sensitivity to the prosodic features of languages that should have a special role in language acquisition. Therefore, we may also assume that pre- and full-term infants having months difference in intrauterine experience show different maturation patterns of processing prosodic and phonetic information present at word level. The aim of our study was to investigate the effect of these differences on word stress pattern vs. phoneme information processing.Two age groups of infants (6 and 10 month-olds) were included in our study. 21 of 46 of the total of infants investigated were prematurely born with low birth weight.We used the mismatch negativity (MMN) event related brain potential (ERP) component, a widely used electrophysiological correlate of acoustic change detection, for testing the assumed developmental changes of phoneme and word stress discrimination. In a passive oddball paradigm we used a word as standard, a pseudo-word as phoneme deviant, and an illegally uttered word as stress deviant.Our results showed no differences in MMN responses in the phoneme deviant condition between the groups, meaning a relatively intact maturation of phoneme processing of preterm infants as compared to their contemporaries. However, the mismatch responses measured in the stress condition revealed significant between-group differences. These results strengthen the view that the total length of intrauterine experience influences the time of emergence of prosodic processing.     

Encoding of nested levels of acoustic regularity in hierarchically organized areas of the human auditory cortex

Our auditory system is able to encode acoustic regularity of growing levels of complexity to model and predict incoming events. Recent evidence suggests that early indices of deviance detection in the time range of the middle‐latency responses (MLR) precede the mismatch negativity (MMN), a well‐established error response associated with deviance detection. While studies suggest that only the MMN, but not early deviance‐related MLR, underlie complex regularity levels, it is not clear whether these two mechanisms interplay during scene analysis by encoding nested levels of acoustic regularity, and whether neuronal sources underlying local and global deviations are hierarchically organized. We registered magnetoencephalographic evoked fields to rapidly presented four‐tone local sequences containing a frequency change. Temporally integrated local events, in turn, defined global regularities, which were infrequently violated by a tone repetition. A global magnetic mismatch negativity (MMNm) was obtained at 140–220 ms when breaking the global regularity, but no deviance‐related effects were shown in early latencies. Conversely, Nbm (45–55 ms) and Pbm (60–75 ms) deflections of the MLR, and an earlier MMNm response at 120–160 ms, responded to local violations. Distinct neuronal generators in the auditory cortex underlay the processing of local and global regularity violations, suggesting that nested levels of complexity of auditory object representations are represented in separated cortical areas. Our results suggest that the different processing stages and anatomical areas involved in the encoding of auditory representations, and the subsequent detection of its violations, are hierarchically organized in the human auditory cortex. Hum Brain Mapp 35:5701–5716, 2014. © 2014 Wiley Periodicals, Inc.