Pupillary responses and event-related potentials as indices of the orienting reflex

This study examined skin conductance responses, the late positive complex of the event-related potential, and pupillary dilation responses as autonomic and central correlates of the orienting reflex (OR) in the context of indifferent and significant stimuli. In particular, we aimed to clarify the inconsistencies surrounding the pupillary dilation response as an OR index. An auditory dishabituation paradigm was employed, and physiological measures were recorded from 24 participants. Response decrement to a repeated stimulus, response recovery to a change stimulus, and subsequent dishabituation were assessed. Findings confirmed expectations that the skin conductance response and the late positive complex are indices of the OR. The pupillary dilation response, however, demonstrated an unexpected sensitivity to stimulus novelty only, while the prestimulus measure of tonic pupil diameter showed the significance effect that was expected of the phasic measure. Together, these findings argue against the suggestion that the pupillary dilation response is an OR index. The diverse results obtained from this experiment contribute to our understanding of the OR, and provide impetus for further research with a variety of paradigm manipulations.     

The neuroprotective action of pyrroloquinoline quinone against glutamate-induced apoptosis in hippocampal neurons is mediated through the activation of PI3K/Akt pathway

Pyrroloquinoline quinone (PQQ), a cofactor in several enzyme-catalyzed redox reactions, possesses a potential capability of scavenging reactive oxygen species (ROS) and inhibiting cell apoptosis. In this study, we investigated the effects of PQQ on glutamate-induced cell death in primary cultured hippocampal neurons and the possible underlying mechanisms. We found that glutamate-induced apoptosis in cultured hippocampal neurons was significantly attenuated by the ensuing PQQ treatment, which also inhibited the glutamate-induced increase in Ca2+ influx, caspase-3 activity, and ROS production, and reversed the glutamate-induced decrease in Bcl-2/Bax ratio. The examination of signaling pathways revealed that PQQ treatment activated the phosphorylation of Akt and suppressed the glutamate-induced phosphorylation of c-Jun N-terminal protein kinase (JNK). And inhibition of phosphatidylinositol-3-kinase (PI3K)/Akt cascade by LY294002 and wortmannin significantly blocked the protective effects of PQQ, and alleviated the increase in Bcl-2/Bax ratio. Taken together, our results indicated that PQQ could protect primary cultured hippocampal neurons against glutamate-induced cell damage by scavenging ROS, reducing Ca2+ influx, and caspase-3 activity, and suggested that PQQ-activated PI3K/Akt signaling might be responsible for its neuroprotective action through modulation of glutamate-induced imbalance between Bcl-2 and Bax.     

Genistein potentiates the effect of arsenic trioxide against human hepatocellular carcinoma: role of Akt and nuclear factor-κB

Hepatocellular carcinoma (HCC) is a highly lethal malignancy mostly because of de novo and acquired resistance to conventional chemotherapy. Constitutive activation of Akt and nuclear factor-κB (NF-κB) represent major cellular abnormalities associated with both the pathogenesis and therapeutic resistance of HCC. The aim of the present study was to determine whether genistein, a natural Akt/NF-κB inhibitor, could enhance the anti-HCC efficacy of ATO both in vitro and in vivo. Our results demonstrated that genistein not only potentiated the proliferation-inhibiting and apoptosis-inducing effect of ATO on human HCC cell lines in vitro, but also dramatically augmented its suppressive effect on both tumor growth and angiogenesis in nude mice. The mechanism is at least partially due to the suppressive effect of genistein both on the proper and ATO-induced Akt activation, and on the activity of NF-κB, and the latter correlated with the suppression of NF-κB regulated gene products, including cyclin D1, Bcl-xL, Bcl-2, c-myc, COX-2, and VEGF. These data suggest that the combination of ATO with genistein presents a promising therapeutic approach for the treatment of HCC.     

Effect of the RW-Cb and its active ingredient like P-acid and P-aldehyde on primary rat osteoblasts

Ethnopharmacological relevance

RW-Cb, the first processed product of Cibotium barometz (L.) J. Sm. (Dicksoniaceae) in TCM has been widely used to treat osteoporosis, a major worldwide health problem, influencing more and more people in the word et al. To do research on RW-Cb, one processed product of Cibotium barometz (L.) J. Sm. (Dicksoniaceae) in TCM has been widely used to treat osteoporosis, a major worldwide health problem, influencing more and more people in the word et al.

Materials and methods

The raw rhizome slices of Cibotium barometz were identified and both P-acid and P-aldehyde had a high purity. Primary rat osteoblasts were cultured and identified to be used for the assay.

Results

RW-Cb contributed the most to osteoblasts proliferation and the AKP activity among all the groups; osteoblasts proliferation effect of P-acid and P-aldehyde: the mixed group(high>middle>low)>the P-acid group (high>middle>low) or the P-aldehyde group(high>middle>low), P<0.001; AKP activity: the P-acid's high group was higher than P-aldehyde's high, the mixed of low and middle groups had no significant difference, the rest of groups' results were similar to the osteoblasts' proliferation, P<0.05.

Conclusions

RW-Cb and its index constituents like P-acid and P-aldehyde could promote proliferation and differentiation of primary rat osteoblasts cultured in vitro, and it could be the theoretical basis for the treatment of osteoporosis.     

Preschool Children's Use of Counting to Compare Two Sets in Cardinal Situations

Two experiments exploring the effect of intervention and test conditions on preschoolers' use of counting to compare two sets. The intervention did not have an effect on younger children's (mean: 3:9) use of counting. At the mean age of 4:4, the children were more likely to use counting to compare sets in the two intervention groups than were the children in the Control group. Children in the Natural test condition were more likely to use counting than were the children in the Traditional test condition. Many 4-year-olds were reluctant to use counting if no intervention prompted it, because (1) they did not know that counting was a better strategy than visual comparison, or because (2) preschool children's use of counting to compare sets was easily affected by contextual factors in a test condition. Preschool children's use of counting to compare sets was closely related to their counting performance.     

Psychiatric admissions and choice of abortion

A statistical analysis is presented of the intensities of admissions to psychiatric hospitals among women in Denmark who either gave birth to a child in the year 1975 or had an induced abortion in the same year. The models used are time-continuous Markov and semi-Markov processes, and the methods employed include non-parametric and semi-parametric analysis of counting processes. The influence of prior psychiatric admissions on the choice of terminating the pregnancy with an induced abortion is also studied.     

生物进化中序列正向选择位点筛选方法的模拟研究

目的探寻生物进化中序列正向选择位点筛选的最佳方法。方法以流感病毒H3亚型HA1序列的进化树分析结果作为产生模拟序列的进化模式,按照不同的进化参数模拟序列数为8、16、32、64、128的样本,分别采用计数模型、固定效应似然比检验模型及随机效应模型筛选模拟序列的正向选择位点。结果随着分析序列数的增多、进化强度的增强,三种方法筛选正向选择位点的灵敏度均增高;同序列数、同进化强度的筛选中,计数模型、随机效应模型的灵敏度显著低于固定效应似然比检验模型;三种模型的运算速度由快至慢分别为计数模型、固定效应似然比检验模型、随机效应模型。结论对于高进化速度、大序列样本的流感病毒正向选择位点筛选,固定效应模型比其他两类方法更加适宜。     

Sensitivity of medial frontal cortex to response and nonresponse conflict

The anterior cingulate cortex (ACC) holds a prominent place in models of the neural architecture supporting cognitive control and conflict processing. The findings of empirical and computational work lead to the prediction that the ACC is sensitive to response conflict and insensitive to nonresponse conflict. We tested this prediction in two experiments using event-related brain potentials in combination with a task in which some trials included only nonresponse conflict and others included nonresponse and response conflict. A N450 associated with the activity of neural generators in the ACC and anterior frontal region was elicited on trials including only nonresponse and nonresponse and response conflict. This finding is inconsistent with the hypothesis that activation of the ACC is limited to response conflict and may identify one avenue of development in future applications of conflict theory.     

The Dot Counting Test adds up: Validation and response pattern analysis in a mixed clinical veteran sample

Objective: This study cross-validated the Dot Counting Test (DCT) as a performance validity test (PVT) among a mixed clinical veteran sample. Completion time and error patterns also were examined by validity group and cognitive impairment status.

Method: This cross-sectional study included 77 veterans who completed the DCT during clinical evaluation. Seventy-four percent (N = 57) were classified as valid and 26% as noncredible (N = 20) via the Word Memory Test (WMT) and Test of Memory Malingering (TOMM). Among valid participants, 47% (N = 27) were cognitively impaired, and 53% (N = 30) were unimpaired.

Results: DCT performance was not significantly associated with age, education, or bilingualism. Seventy-five percent of the overall sample committed at least one error across the 12 stimulus cards; however, valid participants had a 27% higher rate of 0 errors, while noncredible participants had a 35% higher rate of ≥4 errors. Overall, noncredible individuals had significantly longer completion times, more errors, and higher E-scores. Conversely, those with cognitive impairment had longer completion times, but comparable errors to their unimpaired counterparts. Finally, DCT E-scores significantly predicted group membership with 83.1% classification accuracy and an area under the curve of .87 for identifying invalid performance. The optimal cut-score of 15 was associated with 70% sensitivity and 88% specificity.

Conclusion: The DCT demonstrated good classification accuracy and sensitivity/specificity for identifying noncredible performance in this mixed clinical veteran sample, suggesting utility as a non-memory-based PVT with this population. Moreover, cognitive impairment significantly contributed to slower completion times, but not reduced accuracy.     

Can subitizing survive the attentional blink? An ERP study

This study was done to test whether subitizing versus counting are attention demanding based on whether they can be performed during the attentional blink (AB). ERPs were recorded while participants performed a task requiring them to judge the number of dots presented and this judgment task either followed the presentation of a task-relevant item in a rapid stimulus presentation stream (dual-task) or the potential target was task irrelevant (single-task). The behavioral data demonstrated that T2 accuracies decreased as a function of the number of dots not only in counting range, but also in subitizing range. The ERP results showed a delayed P3 component in the dual-task condition, and this was equally true for both subitizing and counting conditions. Furthermore, the P3 amplitude was reduced during the AB, and this was still equally true for both the subitizing and counting conditions. The present results suggest that both subitizing and counting require attention, and that subitizing is not a purely pre-attentive process.