不同程度远视屈光不正性弱视儿童的图形视觉诱发电位

目的:了解不同程度远视屈光不正性弱视儿童的图形视觉诱发电位(Pattern visual evoked potential,P-VEP)特征。方法:2011-05/2012-08在我院就诊的远视屈光不正性弱视儿童,按不同最佳矫正视力(best corrected vision acuity,BCVA)分为3组,P-VEP检查分析比较不同组间及与正常儿童的P100波峰潜时和振幅的变化。结果:正常组P100波峰潜时101.43±6.82ms,P100波振幅为11.27±5.38μV。在不同程度弱视组间P100波峰较正常组潜时延迟,分别为视力高于0.5组110.54±8.47ms,视力0.3～0.5组118.76±6.21ms,视力低于0.3组124.54±7.36ms,且各组间差异有统计学意义(P<0.05)。P100波振幅均较正常下降,分别为轻度组9.94±5.28μV,中度组8.57±7.21μV,重度组7.49±5.07μV,各组间比较差异有统计学意义(P<0.05)。结论:远视屈光不正弱视儿童的图形视觉诱发电位弱视眼的P100波峰潜时延迟、P100波振幅下降。且P100波峰潜时延迟、P100波振幅下降与弱视程度相关。     

Validity and power in hemodynamic response modeling: a comparison study and a new approach

One of the advantages of event-related functional MRI (fMRI) is that it permits estimation of the shape of the hemodynamic response function (HRF) elicited by cognitive events. Although studies to date have focused almost exclusively on the magnitude of evoked HRFs across different tasks, there is growing interest in testing other statistics, such as the time-to-peak and duration of activation as well. Although there are many ways to estimate such parameters, we suggest three criteria for optimal estimation: 1) the relationship between parameter estimates and neural activity must be as transparent as possible; 2) parameter estimates should be independent of one another, so that true differences among conditions in one parameter (e.g., hemodynamic response delay) are not confused for apparent differences in other parameters (e.g., magnitude); and 3) statistical power should be maximized. In this work, we introduce a new modeling technique, based on the superposition of three inverse logit functions (IL), designed to achieve these criteria. In simulations based on real fMRI data, we compare the IL model with several other popular methods, including smooth finite impulse response (FIR) models, the canonical HRF with derivatives, nonlinear fits using a canonical HRF, and a standard canonical model. The IL model achieves the best overall balance between parameter interpretability and power. The FIR model was the next-best choice, with gains in power at some cost to parameter independence. We provide software implementing the IL model.     

Efficacy and tolerability of indiplon in older adults with primary insomnia

OBJECTIVE: To evaluate the efficacy and safety of indiplon in elderly patients with primary insomnia. PATIENTS AND METHODS: Elderly patients, 65-80 years (N=358; 55% female; mean age, 71 years) who met the criteria for primary insomnia according to the Diagnostic and Statistical Manual of Mental Disorders, fourth edition (DSM-IV) for three months were randomized to two weeks of double-blind nightly treatment with 5 mg or 10 mg indiplon or placebo. Daily self-assessments by the patients included latency to sleep onset (LSO), total sleep time (TST), number of awakenings (NAW), wake time after sleep onset (WASO), and sleep quality. Data were collected between July, 2002, and October, 2003, at 52 clinical research sites in North America. RESULTS: Treatment with indiplon was associated with significant reduction in LSO at Week 1 for the 5 mg (34.6+/-1.8 min) and 10 mg doses (30.4+/-1.6 min) relative to placebo (47.4+/-2.5 min; p<0.0001 for both comparisons). During Week 2, LSO remained shorter on both indiplon doses compared to placebo (5 mg, p=0.016; and 10 mg, p=0.0028). During both study weeks, treatment with indiplon was also associated with significant improvement, relative to placebo, in TST, NAW, WASO, and sleep quality. The frequency of adverse events was similar in the indiplon 5 mg and placebo groups; somnolence, nausea, depression and decreased appetite were slightly more common in the indiplon 10 mg group. CONCLUSION: In elderly patients with primary insomnia, indiplon 5 mg and 10 mg were efficacious in inducing and maintaining sleep and improving sleep quality during the two weeks of treatment. Indiplon 5mg was well-tolerated, with no serious adverse events and no significant changes in electrocardiogram (ECG) or routine clinical laboratory evaluations; the 10mg dose produced slightly greater efficacy as well as somewhat increased adverse events.     

内囊出血家兔短潜伏期体感诱发电位的改变

目的:探讨内囊出血对短潜伏期体感诱发电位的影响。方法:立体定向注射自体动脉血制备家兔内囊出血动物模型,观察内囊出血前后家兔脑组织的病理形态学变化;短潜伏期体感诱发电位(SLSEP)的改变。结果:家兔内囊出血后,脑组织出现明显的占位血肿;造模后不同时点,SLSEP中P1-N1的峰间潜伏期较出血前均明显延长(P<0.01);N2-P1峰-峰值较出血前均明显减小(P<0.01)。结论:内囊出血可阻碍神经冲动传导,从而导致SLSEP中P1-N1的峰间潜伏期延长;N2-P1峰-峰值减小。     

The presence of BRAF point mutation in adult papillary thyroid carcinomas from atomic bomb survivors correlates with radiation dose

In papillary thyroid carcinogenesis, the constitutively activated mitogen-activated protein (MAP) kinase signaling pathway caused by a genetic alteration such as RET/PTC rearrangement or mutation of RAS and BRAF genes, is thought to be a major early event. Among these, the recently identified BRAF(V600E) mutation has been found at high frequency in adult patients with papillary thyroid carcinoma (PTC). However, the association between this mutation and radiation exposure in adult PTC is still unknown. In this study, we examined the BRAF(V600E) mutation in 64 PTCs among adult atomic bomb survivors in Hiroshima, Japan, comprising 17 nonexposed (0 mGy) and 47 exposed patients who developed the carcinoma after the bombing, and assessed the association of BRAF(V600E) mutation with clinico-pathological and epidemiological variables. The median radiation dose in PTCs with the BRAF(V600E) mutation was significantly lower than that without the mutation (18.5 vs.156.9 mGy, Wilcoxon rank-sum test, P=0.022). A significant difference was found in the median latency period (years elapsed from atomic bombing to diagnosis) between exposed patients with and without BRAF(V600E) mutation (29 vs. 21 yr, Wilcoxon rank-sum test, P=0.014). These findings were further confirmed by logistic regression analysis with BRAF(V600E) mutation status as a dependent variable and taking into account possible interactions between the variables. We found that the log-transformed radiation dose and latency period were independently associated with the BRAF(V600E) mutation (P=0.039 and P=0.010, respectively). These results suggest that involvement of BRAF mutation in thyroid carcinogenesis in exposed people may differ from that in the nonexposed people.     

The amplitude of lower leg motor evoked potentials is a reliable measure when controlled for torque and motor task

OBJECTIVES: Motor evoked potential (MEP) amplitudes have the disadvantage of a high variability when repeatedly assessed. This affects the reliability of MEP amplitude measurements taken during the course of motor incomplete spinal cord injury (iSCI). The study investigated the reliability of anterior tibial (TA) MEP measures controlled for dorsal flexion torque and motor task. METHODS: TA MEPs were recorded at 10, 20, 40 and 60% of maximal voluntary contraction (MVC) during a static and dynamic (isometric increase of dorsal flexion torque) motor task. To determine reliability, 20 healthy and five chronic iSCI subjects were tested twice (> or =7 days) by the same investigator. Intraclass correlation coefficients (ICCs) were calculated. MEP amplitudes and latencies were compared between 20 healthy and 29 iSCI subjects. RESULTS: The reliability of MEP amplitude was in general good (ICC > or = 0.52) and was highest during the static task at 40% MVC (ICC = 0.77). The increased facilitation by the dynamic motor task showed the best reliability at 20% MVC (ICC = 0.48). The reliability was good to excellent for MEP latency (0.46 < or = ICC < or = 0.81), MVC (ICC > or = 0.90) and for the TMS threshold required to evoke a MEP response (ICC > or = 0.77). The torque generated by the MEP response ()0.02 < or = ICC < or = 0.55) and the duration of the silent period (0.07 < or = ICC < or = 0.50) were not reliable. Both MEP amplitudes and latencies differed significantly between healthy and iSCI subjects. CONCLUSIONS: Controlling for torque generation and motor task establishes a reliability of TA MEP amplitudes that is sufficient for longitudinal assessments in motor incomplete SCI.     

Neurovirulence and latency of drug‐resistant clinical herpes simplex viruses in animal models

Herpes simplex virus (HSV) resistance to acyclovir or foscarnet results from mutations in viral thymidine kinase (TK) and/or DNA polymerase (pol) genes. Replication kinetics and virulence of TK and/or DNA pol clinical mutants were assessed using models of mouse encephalitis and cotton rat genital infection. Replication capacities in Vero cells of a DNA pol altered strain (L850I) and a TK/DNA pol mutant (C467deletion/A912V) were significantly lower than those of unrelated wild‐type (WT) strains, while a double DNA pol mutant (S724N/P920S) demonstrated replication kinetics similar to the WT. The replication of a TK‐deficient mutant (G439.5addition) was impaired (low m.o.i.) or unaltered (high m.o.i.) compared to that of a WT virus depending on the viral inoculum. Compared to a survival rate of 6% for mice infected intranasally with WT HSV‐1 or ‐2 viruses, G439.5add, C467deletion/A912V and L850I strains were associated with survival rates of 100% (P < 0.05) whereas mice infected with the S724N/P920S mutant had a survival rate of 33% (P = 0.08). Brain viral titers were higher in mice infected with WT HSV‐1 or ‐2 strains and the double DNA pol mutant. All strains except the DNA pol mutant L850I were able to establish latency in the dorsal root ganglia of cotton rats. A good correlation was generally found between replication kinetics of DNA pol mutants and their neurovirulence potential in mice whereas such correlation was not straightforward for TK mutants. J. Med. Virol. 82:1000–1006, 2010. © 2010 Wiley‐Liss, Inc.     

JCV/BKV and SV40 viral load in lymphoid tissues of young immunocompetent children from an area of North‐East Italy

Polyomavirus infection occurring during childhood is followed by a lifelong latency in immunocompetent subjects. The major site of polyomavirus persistence are the uroepithelial cells which leads to oral transmission. It has recently been hypothesized that tonsils could be a possible reservoir. The role of tonsil, adenoid, and peripheral blood mononuclear cells (PBMCs) as possible sites of JCV, BKV, and SV40 latency in young healthy children was assessed. Two hundred fifteen fresh specimens, including 57 tonsil, 80 adenoid, and 78 PBMC samples from 80 immunocompetent children (mean age 4.8 years) were analyzed to determine the viral load by quantitative real‐time PCR. The human herpes virus 6 (HHV‐6) was tested as a lymphotropic reference virus. Polyomavirus was detected in 5/80 (6.2%) children while HHV‐6 infection affected 27/80 children (33.7%) (P < 0.001). SV40 was detected in one adenoid sample, while footprints of BKV were found in one adenoid and three tonsil samples. JCV was never found in all samples. Polyomavirus sequences were not detected in the 78 blood samples. One adenoid and two tonsils from three children (1.4%) were positive for both polyomavirus and HHV‐6. Infections were characterized by low replication rates ranging typically from 1 × 10e²/5.5 × 10e⁴ to 6.8 × 10e³/8.5 × 10e⁴ viral copies/number of cells. In conclusion, tonsils and adenoids of children could effectively harbor BKV and SV40, although only very few cells proved to be infected. Nevertheless, the low prevalence of polyomavirus, in comparison with the lymphotropic HHV‐6, suggests that these tissues are unlikely to be the preferred site of polyomavirus latency, at least in younger children. J. Med. Virol. 82:1236–1240, 2010. © 2010 Wiley‐Liss, Inc.     

Sleep Symptoms During the Menopausal Transition and Early Postmenopause: Observations from the Seattle Midlife Women's Health Study

Study Objectives:

Describe the severity of getting to sleep, nighttime awakening, and early morning awakening across the menopausal transition (MT) and early postmenopause (PM) and their relationship to age, menopausal transition factors, symptoms, stress-related factors, and health related factors.

Design:

Cohort

Setting:

community

Participants:

286 women from the Seattle Midlife Women''s Health Study cohort

Measurements:

Participants completed annual menstrual calendars for MT staging, diaries in which they rated their symptoms, stress levels, and perceived health multiple times per year from 1990-2007 and provided first morning urine samples assayed for E1G, FSH, cortisol, and catecholamines. Multilevel modeling (R program) was used for data analysis.

Results:

Severity of self-reported problems going to sleep was associated with all symptoms, perceived stress, history of sexual abuse, perceived health (-), alcohol use (-) (all P < 0.001), and lower cortisol (P = 0.009), but not E1G or FSH. Severity of nighttime awakening was significantly associated with age, late MT stage. and early PM, FSH, E1G (-), hot flashes, depressed mood, anxiety, joint pain, backache, perceived stress, history of sexual abuse, perceived health (-), and alcohol use (-) (all P < 0.001, except E1G for which P = 0.030). Severity of early morning awakening was significantly associated with age, hot flashes, depressed mood anxiety, joint pain, backache, perceived stress, history of sexual abuse, perceived health (-) (all P ≤ 0.001, except E1G for which P = 0.02 and epinephrine (P = 0.038), but not MT stages or FSH. Multivariate models for each symptom included hot flashes, depressed mood, and perceived health.

Conclusion:

Sleep symptoms during the MT may be amenable to symptom management strategies that take into account the symptom clusters and promote women''s general health rather than focusing only on the MT.

Citation:

Woods NF; Mitchell ES. Sleep symptoms during the menopausal transition and early postmenopause: observations from the seattle midlife women''s health study. SLEEP 2010;33(4):539-549.     

基于小波变换的事件相关电位少次提取方法

本文以反映大脑稀少认知事件的相关电位P300为例,介绍了基于小波变换(wavelet transform,WT)进行事件相关电位(event related potential,ERP)少次提取的原理、仿真和实验结果.通过小波变换先去除与ERP混杂的EEG背景干扰,然后对消除干扰后的脑电数据进行重构和ERP波峰检测,在此基础上尝试修正ERP波峰的潜伏期时移,再通过小波重构获得通常需多次相干平均才能得到的ERP波形.仿真计算和实验数据分析结果说明小波分析具有较强的ERP峰值检测和潜伏期模式识别能力,值得进一步在临床工程中深入研究和应用推广.