Fragmentary blackouts: their etiology and effect on alcohol expectancies

BACKGROUND: Fragmentary blackouts, or memory loss for intoxicated events that may be later recalled with the provision of cues, are common sequelae of heavy drinking, yet understanding of their characteristics, correlates, and consequences is limited. Consequently, this alcohol-administration study addressed questions regarding the etiology of fragmentary blackouts and their effect on alcohol outcome expectancies. METHODS: A placebo-controlled design addressed the etiology of fragmentary blackouts through assessment of memory formation before and after alcohol consumption. The effect of fragmentary blackouts on prospective beliefs about alcohol was assessed by way of a self-report outcome expectancy questionnaire and a measure of response latency for alcohol concepts presented after beverage consumption. RESULTS: Although participants performed similarly on memory indices before consuming beverages, those who reported past fragmentary blackouts and consumed alcohol displayed marked difficulty with recall of a narrative when this was attempted both during intoxication and after detoxification, as well as with a source memory task presented during intoxication. Those reporting fragmentary blackouts also endorsed stronger outcome expectancies for a range of alcohol effects and exhibited greater accessibility for positive alcohol concepts presented after beverage administration. Further, source recall contributed significantly to the episodic recall both during intoxication and after detoxification, as well as to positive outcome expectancies of those receiving alcohol. CONCLUSIONS: Findings suggest that fragmentary blackouts result from poor retrieval and that individual differences in retrieval emerge after alcohol is consumed. Further, one's recall of source aspects of material-its time and social context-is an important determinant of recall of stimuli and events encountered during intoxication, as well as of prospective expectations for positive alcohol effects. The collective findings expand our understanding of this complex yet common neuropsychological consequence of heavy drinking.     

新型凝集素Intelectin的研究进展

凝集素是自然界广泛存在的一大类糖结合蛋白,凝集素家族有多种生物学功能,包括细胞的黏附、分化、凋亡、肿瘤抗原的识别和细胞与细胞间的信号识别等.Intelectin是一种分泌型可溶性糖蛋白,属于凝集素家族.目前,国内外对Intelectin的研究日益增多,也越来越深入,文章综述了Intelectin的来源、结构、分类和生物学功能方面的研究现状,为进一步了解和研究Intelectin提供参考.     

HDR brachytherapy well chamber calibration and stability evaluated over twenty years of clinical use

PurposeThe purpose of the study was to establish, using a retrospective analysis of existing hospital records, the long-term stability and accuracy of a high-dose-rate brachytherapy well chamber. This should be assessed to determine reliability and appropriate calibration frequency. The accrual of long-term data that demonstrates the stability of our chamber may inform others of the performance they might expect from similar equipment.Methods and MaterialsWe evaluated air kerma strength measurements made with the PTW 32002 (Nucletron 077.091) high-dose-rate well chamber on 72 ¹⁹²Ir sources over an 18-year period and the seven calibrations of that chamber which span a 27-year period.ResultsConsecutive air kerma strength measurements agreed within 0.01% on average. The chamber measurement agreed with the source specification within 0.02% on average, but was up to 1.4% during some calibration periods. The chamber calibration coefficient varied by a maximum of 5% over seven chamber calibration measurements.ConclusionsThe constancy of the well chamber current compared with the source manufacturer suggests that our chamber has been stable to better than 2% over a period of 18 years. Although the chamber has received different calibration coefficients over time, these coefficients are within the combined uncertainties of any two calibrations and are consistent with the chamber being stable. The agreement we have observed between clinical measurements and the source manufacturer would justify an action level for further investigation of 1%, for this specific chamber.     

Source Generators of Mismatch Negativity to Multiple Deviant Stimulus Types

The purpose of the present study was to investigate auditory stimulus feature processing and how neural generators might differ among the mismatch negativity (MMN) responses to intensity, frequency, and duration deviant stimuli. Data collected from 72 electrodes in twelve adult female subjects were analyzed. For each subject, peak amplitude and latency values at Fz were compared among responses to the three deviant stimulus types presented in individual conditions with a probability of 0.10 and 0.30, and in the multiple deviant condition in which all three deviant types were presented (design based on Deacon et al. 1998). Further, equivalent current dipoles (ECD) for each deviant type, in each condition, and for each subject were calculated in three areas: right hemisphere, left hemisphere, and frontal. Peak amplitude and latency measured at Fz were consistent with previous findings by Deacon et al. (1998) and suggested parallel processing, perhaps by separate neural generators. However, ECD locations were not significantly different among the responses to the different deviant types. Further, the ECD magnitudes did not consistently reflect the differences in amplitude observed at the scalp among responses to the deviant types and conditions. The latter finding may indicate that the procedures were not sensitive enough to identify true differences among the generators. Alternatively, it was suggested that searching for separate neural generators at the cortical level may be too restrictive because the process may begin in subcortical areas, as indicated in animal models.     

Distributed source localization of interictal spikes in benign childhood epilepsy with centrotemporal spikes: A standardized low-resolution brain electromagnetic tomography (sLORETA) study

Benign childhood epilepsy with centrotemporal spikes (BCECTS), also known as Rolandic epilepsy, is the most common benign childhood epilepsy. Centrotemporal spikes are characteristic findings on electroencephalography (EEG). Though the condition is considered benign, many studies have reported some degree of neuropsychological impairment in individuals with BCECTS. There is also growing evidence from neuroimaging studies that BCECTS may affect a larger portion of the brain than originally thought. We performed distributed source localization analysis of interictal spikes in BCECTS. Current-source density (CSD) of the maximal negative peak of the interictal spikes averaged from each of 20 EEG epochs in 11 patients with BCECTS was measured using standardized low-resolution brain electromagnetic tomography (sLORETA). Rolandic area was included in the distribution of the CSD in all of the patients. The significant CSD and its maximal point were distributed in multiple cortical regions over the Rolandic area. It is suggested that the widespread cortical distribution of interictal spikes seen in this study may be associated with atypical presentation and a variety of comorbidities of BCECTS. Our results imply that BCECTS represents a deviation from normal development during a critical period of brain maturation and that children with BECTS might be more likely to need special medical attention.     

Age-related changes in neural activity during source memory encoding in young, middle-aged and elderly adults

Source memory, the ability to remember contextual information present at the moment an event occurs, declines gradually during normal aging. The present study addressed whether source memory decline is related to changes in neural activity during encoding across age. Event-related potentials (ERPs) were recorded in three groups of 14 subjects each: young (21-26 years), middle-aged (50-55 years) and older adults (70-77 years). ERPs were recorded while the subjects performed a natural/artificial judgment on images of common objects that were presented randomly in one of the quadrants of the screen (encoding phase). At retrieval, old images mixed with new ones were presented at the center of the screen and the subjects judged whether each image was new or old and, if old, were asked to indicate at which position of the screen the image was presented in the encoding session. The neurophysiological activity recorded during encoding was segregated for the study items according to whether their context was correctly retrieved or not, so as to search for subsequent memory effects (SME). These effects, which consisted of larger amplitude for items subsequently attracting a correct source judgment than an incorrect one, were observed in the three groups, but their onset was delayed across the age groups. The amplitude of the SME was similar across age groups at the frontal and central electrode sites, but was manifested more at the posterior sites in middle-aged and older adults, suggesting that source memory decline may be related to less efficient encoding mechanisms.     

TMS by double-cone coil prefrontal stimulation for medication resistant chronic depression: A case report

A double-cone coil with large angled windings has been developed to modulate deeper brain areas such as the anterior cingulate cortex (ACC). Abnormal resting state activity in the pregenual ACC (pgACC), dorsal ACC (dACC) and subgenual ACC (sgACC) has been observed in depression. A patient with medication resistant chronic depression received ten sessions of transcranial magnetic stimulation (TMS) (10 Hz, 2000 stimuli/session) using a double-cone coil placed over the supplementary motor area, targeting the anterior cingulate. Source localized EEG recordings were conducted pre- and post-TMS. The Beck Depression Inventory (BDI-II) improved by 27%, and the two subscales of the Hospital Anxiety Depression Scale (HADS), namely depression (40%) and anxiety (33%) improved as well. Along with the clinical improvement eletrophysiological resting state activity changed in the dACC and sgACC in this patient in comparison to a normative group. The results of this case report further support the involvement of pgACC, dACC and sgACC activity in the pathophysiology of depression and indicate that modulation of neural activity in this area by high frequency TMS with a double-cone coil might represent a new promising approach in the treatment of medication resistant chronic depression.     

科研评价政策导向与医学期刊的发展

科技期刊的核心竞争力在于稿件质量,但目前大部分科技期刊都面临着稿源数量与质量未能同步上升的困境。本文分析了科技期刊存在的几种稿源困境,如投稿数量多,可用稿件少;自投稿件多,组稿策划少;约稿稿件未能达到发表要求,重复投稿多等问题,并针对这些问题,提出了明确期刊定位、优化栏目设置、优化编辑流程、集中编辑精力、严把审稿关确保稿件质量、精心策划热点选题拓展组稿渠道、培育核心作者群等组稿优化策略。     

中药薤白的研究进展

薤白中含有挥发油、皂苷、含氮化合物、酸性物质等,为临床治疗"胸痹"之要药,也是治疗泄痢常用之品。因薤白具有很高的药用价值,故历来已有较多研究。通过查阅相关文献及书籍,本文对薤白的生药来源、化学成分、药理作用以及合用历史沿革等方面进行了整理和归纳,旨在为薤白的进一步研究开发提供新的思路。     

Neuromagnetic functional Localization: Principles,state of the art,and perspectives

The neuromagnetic method has been providing impressive results in the understanding of the functions and of some pathologies of the human brain. The possibility of achieving three-dimensional source localization represents a fundamental step forward in the study of the organization of cortical areas, in that of focal disorders and, in general, in the investigation of brain information processing. The development of large multichannel systems to achieve real time functional localization is being carried on in several countries and the first prototypes are already operating for a full assessment of the benefits of the technique. The use of time-varying magnetic pulses provides the opportunity for non-invasive stimulation of the central nervous system toward the achievement of functional imaging of the motor cortices.