免疫反应影响动脉粥样硬化进程的两面性

大量研究表明,动脉粥样硬化的发生和发展过程中,能观察到许多免疫反应.然而,免疫反应对动脉粥样硬化的作用却呈现为两面性:免疫系统的激活可加速动脉粥样硬化的形成和发展,也可表现出抗动脉粥样硬化功效.所以,适当的免疫调节干预,有望成为动脉粥样硬化的预防及治疗的新途径.     

感染对缺血性脑卒中发病的影响

缺血性脑卒中的发生除传统高危因素外还和动脉的炎性反应有关,如血管壁内炎性细胞的聚集,早期参与触发动脉粥样硬化的形成,晚期促进动脉粥样硬化斑块的破裂和血栓的形成。微生物的慢性感染已被发现有增加卒中发生的危险,而机体产生免疫反应的强弱程度也起到重要作用。微生物的感染通过多个机制影响卒中的发生。概述了感染、炎症与缺血性脑卒中发病方面的研究现状以及由此带来的对缺血性脑卒中预防与治疗决策的可能影响。     

感染对缺血性脑卒中发病的影响

缺血性脑卒中的发生除传统高危因素外还和动脉的炎性反应有关,如血管壁内炎性细胞的聚集,早期参与触发动脉粥样硬化的形成,晚期促进动脉粥样硬化斑块的破裂和血栓的形成.微生物的慢性感染已被发现有增加卒中发生的危险,而机体产生免疫反应的强弱程度也起到重要作用.微生物的感染通过多个机制影响卒中的发生.概述了感染、炎症与缺血性脑卒中发病方面的研究现状以及由此带来的对缺血性脑卒中预防与治疗决策的可能影响.     

高密度脂蛋白在动脉粥样硬化发病中的双重作用

生理状态的高密度脂蛋白（high density lipoprotein,HDL）被普遍认为具有抗动脉粥样硬化功效,是冠心病的重要保护因子。然而,在某些病理状态下,HDL的抗动脉粥样硬化功能受损,甚至逆转产生致动脉粥样硬化作用,药物干预又可改善HDL的抗动脉粥样硬化功能。用矛盾的哲学规律认识高密度脂蛋白与动脉粥样硬化的关系,并在实际工作中抓住主要矛盾,就能更有成效地开展对HDL研究。     

血管平滑肌细胞在动脉粥样硬化发生中的哲学思维

随着对血管平滑肌细胞增殖在动脉粥样硬化中研究的不断深入,逐步意识到细胞凋亡的存在及其相互之间的矛盾关系,对动脉粥样硬化的认识亦由从形态结构和生化组成等描述病变,发展为在细胞乃至分子基因水平上的深入研究,发现血管平滑肌细胞的增殖和凋亡在动脉粥样硬化形成过程中起重要作用。从哲学角度探讨血管平滑肌细胞在动脉粥样硬化发生中的作用,有助于科学的发现疾病的本质。     

氧化型低密度脂蛋白：致动脉粥样硬化和抗动脉粥样硬化的双重作用

研究证明,氧化型低密度脂蛋白（oxLDL）,而不是低密度脂蛋白,是致动脉粥样硬化的独立危险因素。oxLDL主要通过巨噬细胞上的清道夫受体摄入oxLDL,引起血管壁泡沫细胞的堆积和脂纹的形成;oxLDL还改变了内皮细胞、平滑肌细胞、血小板的多种功能,使之释放多种致炎细胞因子,促进了炎症细胞的趋化和聚集。但最近有报道认为,口服免疫耐量的oxLDL可弱化早期和晚期动脉粥样硬化。因此,oxLDL不仅能导致动脉粥样硬化,在某些情况下,还具有抗动脉粥样硬化的作用。本文从辩证法的角度出发,系统的阐述oxLDL的这一双重作用。     

C-反应蛋白与动脉粥样硬化——谁才是始作俑者

C-反应蛋白可用于监测冠心病患者病情变化、预测冠心病的预后以及预报健康人群冠心病的发病风险。最近的研究显示,C-反应蛋白可能是动脉粥样硬化的始动因子。药物干预可以通过降低C-反应蛋白发挥抗动脉粥样硬化作用。本文分析了C-反应蛋白与动脉粥样硬化的因果关系及其在临床工作中的重要意义。     

氧化型低密度脂蛋白:致动脉粥样硬化和抗动脉粥样硬化的双重作用

研究证明,氧化型低密度脂蛋白(oxLDL),而不是低密度脂蛋白,是致动脉粥样硬化的独立危险因素.oxLDL主要通过巨噬细胞上的清道夫受体摄入oxLDL,引起血管壁泡沫细胞的堆积和脂纹的形成;oxLDL还改变了内皮细胞、平滑肌细胞、血小板的多种功能,使之释放多种致炎细胞因子,促进了炎症细胞的趋化和聚集.但最近有报道认为,口服免疫耐量的oxLDL可弱化早期和晚期动脉粥样硬化.因此,oxLDL不仅能导致动脉粥样硬化,在某些情况下,还具有抗动脉粥样硬化的作用.本文从辩证法的角度出发,系统的阐述oxLDL的这一双重作用.     

热休克蛋白7O在动脉粥样硬化发病中的双重作用

大多研究表明,热休克蛋白70通过抗凋亡、抗氧化及抗炎症反应而在动脉粥样硬化发病中起保护作用。但亦有研究表明,热休克蛋白70通过促凋亡、促进炎症反应而在动脉粥样硬化的发生发展中起促进作用。说明热休克蛋白70在动脉粥样硬化发病中有双重作用,进行基础研究和临床干预时应考虑到其双面性。     

C-反应蛋白与动脉粥样硬化——谁才是始作俑者

C-反应蛋白可用于监测冠心痛患者病情变化、预测冠心病的预后以及预报健康人群冠心病的发病风险.最近的研究显示,C-反应蛋白可能是动脉粥样硬化的始动因子.药物干预可以通过降低C-反应蛋白发挥抗动脉粥样硬化作用.本文分析了C-反应蛋白与动脉粥样硬化的因果关系及其在临床工作中的重要意义.     

An effect of spatial-temporal association of response codes: understanding the cognitive representations of time

The present study addresses the question of how such an abstract concept as time is represented by our cognitive system. Specifically, the aim was to assess whether temporal information is cognitively represented through left-to-right spatial coordinates, as already shown for other ordered sequences (e.g., numbers). In Experiment 1, the task-relevant information was the temporal duration of a cross. RTs were shorter when short and long durations had to be responded to with left and right hands, respectively, than with the opposite stimulus-response mapping. The possible explanation that the foreperiod effect (i.e., shorter RTs for longer durations) is greater with right than with left hand responses is discarded by results of Experiment 2, in which right and left hand responses alternated block-wise in a variable foreperiod paradigm. Other explanations concerning manual or hemispheric asymmetries may be excluded based on the results of control experiments, which show that the compatibility effect between response side and cross duration occurs for accuracy when responses are given with crossed hands (Experiment 3), and for RTs when responses are given within one hand (Experiment 4). This pattern suggests that elapsing time, similarly to other ordered information, is represented in some circumstances through an internal spatial reference frame, in a way that may influence motor performance. Finally, in Experiment 5, the temporal duration was parametrically varied using different values for each response category (i.e., 3 short and 3 long durations). The compatibility effect between hand and duration was replicated, but followed a rectangular function of the duration. The shape of this function is discussed in relation to the specific task demands.     

Hand-foot motor priming in the presence of temporary inability to use hands

To verify if the link between observed hand actions and executed foot actions found in aplasics is essentially induced by the constant use of foot substituting the hand, we investigated if the vision of a grasping hand is able to prime a foot response in normals. Participants were required to detect the time-to-contact of a hand grasping an object either with a suitable or a less suitable movement, an experimental paradigm known to induce a priming effect. Participants responded either with the hand or the foot, while having free or bound hands. Results showed that for hand responses motor priming effect was stronger when the hands were free, whereas for foot responses it was stronger when the hands were bound. These data are interpreted as a further evidence that a difficulty to move affects specific cognitive functions and that the vision of a grasping hand may prime a foot response.     

Hand–foot motor priming in the presence of temporary inability to use hands

To verify if the link between observed hand actions and executed foot actions found in aplasics is essentially induced by the constant use of foot substituting the hand, we investigated if the vision of a grasping hand is able to prime a foot response in normals. Participants were required to detect the time-to-contact of a hand grasping an object either with a suitable or a less suitable movement, an experimental paradigm known to induce a priming effect. Participants responded either with the hand or the foot, while having free or bound hands. Results showed that for hand responses motor priming effect was stronger when the hands were free, whereas for foot responses it was stronger when the hands were bound. These data are interpreted as a further evidence that a difficulty to move affects specific cognitive functions and that the vision of a grasping hand may prime a foot response.     

The influence of response grouping on free-choice decision making in a response selection task

Previous research has demonstrated an advantage for the preparation of fingers on one hand over the preparation of fingers on two hands, and for the preparation of homologous fingers over that of non-homologous fingers. In the present study, we extended the precuing effects observed with finger responses to response selection under free-choice conditions. Participants were required to choose from a range of possible responses following the presentation of a precue that indicated which response to prepare (go-to precue) or prevent (no-go-to precue). In Experiment 1 the choice was between homologous and non-homologous finger responses on the hand opposite to the precue while in Experiment 2 the choice was between finger responses on the same or different hand to the precue. In the go-to precue condition, the frequency of homologous finger choices was more frequent than non-homologous finger responses. Similarly, participants chose finger responses on the same hand as the precue regardless of whether they were instructed to prepare or prevent the precued response. The hand effect bias was stronger than the finger effect bias. These findings are consistent with the Grouping Model (Adam, Hommel, & Umilta, 2003).     

Effects of mental stressors on mitogen induced lymphocyte responses in the laboratory

Abstract

There is considerable evidence from naturalistic studies that psychosocial stressors affect human immune function. To achieve control over factors that could bias naturalistic studies, laboratory stressors developed by cardiovascular researchers were tested to determine if they affected immune function. Thirty volunteer students were exposed to 20 minutes of mental tasks. Psychophysiological indices (heart rate, blood pressure, skin conductance) and subjective responses were monitored prior to, during, and 1-hour after the tasks, blood, samples for immunological analyses were also drawn at these times. Thirteen subjects who were not exposed to the tasks served as controls. Subjects exposed to the tasks showed increased levels of subjective distress and increased psychophysiologic responses (except diastolic blood pressure) during the tasks. Relative to controls, stressed subjects had reduced lymphocyte proliferative responses to classic T cell mitogens both immediately after and 1-hour after the tasks were found in whole blood cultures, although responses of isolated lymphocytes were not significantly affected. There were only marginal differences in whole blood mitogen responses for stressed subjects with low versus high autonomic reactions to the stressor. These results support an emerging view that the immune system is sensitive to brief stressors and that laboratory models may be useful for exploring stress-induced changes in immune function.     

S-R compatibility between response position and destination of apparent motion: evidence of the detection of affordances

In choice reaction time, stimuli and responses in some combinations (e.g., based on spatial arrangement) are faster than in other combinations. To test whether motion toward a position yields faster responses at that position, a computer-generated square in front of one hand appeared to move either toward that hand or toward the other hand. Compatible responses (e.g., motion toward left hand/left response) were faster than incompatible responses, even when that opposed traditional positional compatibility. In Experiment 2, subjects responded to the same stimuli but with both hands left, right, or on the body midline. Medial responses were the fastest, showing that destination, rather than mere relative position, was a critical variable. It was suggested that spatial compatibility effects are not unique to position but apply to a variety of task situations, describable by J.J. Gibson's theory of affordances, in which he claims that one perceives the actions (e.g., catching) permitted in a situation.     

The psychobiology of stress

Stressful life experience can have significant effects on a variety of physiological systems, including the autonomic nervous system, the hypothalamic-pituitary-adrenal axis, and the immune system. These relationships can be bidirectional; for example, immune cell products can act on the brain, altering mood and cognition, potentially contributing to depression. Although acute physiological alterations may be adaptive in the short term, chronic or repeated provocation can result in damage to health. The central dogma in the field of stress research assumes a stereotyped physiological response to all stressors (the generality model). However, increasing evidence suggests that specific stressful conditions and the specific way an organism appraises these conditions can elicit qualitatively distinct emotional and physiological responses (the integrated specificity model). For example, appraisals of threat (vs. challenge), uncontrollability, and negative social evaluation have been shown to provoke specific psychobiological responses. Emotional responses appear to have specific neural substrates, which can result in differentiated alterations in peripheral physiological systems, so that it is incorrect to presume a uniform stress response.     

Psychosocial Factors and Disease Progression in Cancer

ABSTRACT— Psychosocial factors such as stress, personality, and social support relate to differences in disease progression in cancer patients. Neuroendocrine substances associated with psychosocial factors may regulate immune responses to cancer, as well as regulate the activity of oncogenic (cancer-causing) viruses, DNA-repair processes, and the expression in tumor cells of genes that may affect the tumor's growth and metastasis. Biobehavioral oncology research seeks to understand how these psychosocial factors, and interventions designed to modify them, become neurohormonal changes that alter cell signaling and tumor growth, viral oncogenesis, and immune responses. We review the empirical basis for psychosocial factors and biobehavioral processes in cancer progression and suggest future research.     

Neuroimmune stress responses: reciprocal connections between the hypothalamus and the brainstem

Hypothalamic nuclei, particularly the paraventricular nuclei (PVN), are important brain sites responsible for eliciting stress responses following a systemic immune challenge. The activation of PVN cells by a systemic immune challenge is critically dependent on the integrity of inputs from brainstem cells situated in the nucleus tractus solitarius (NTS) and ventrolateral medulla (VLM). Interestingly, a descending pathway from the PVN to the brainstem, recruited by systemic immune challenge, might also exist. It is well documented that PVN neurons innervate the NTS and VLM and recent evidence from our laboratory shows that lesions of the PVN reduce brainstem cell responses elicited by a systemic bolus of the proinflammatory cytokine interleukin-1beta (IL-1beta). Although a number of different PVN divisions are candidates for the source of inputs to the brainstem, we have demonstrated that the majority of descending PVN projections recruited by systemic IL-1beta arise from cell bodies localized in the medial and lateral parvocellular PVN. These findings suggest that central nervous system responses to an immune challenge are likely to involve complex reciprocal connections between the PVN and the brainstem, whereby brainstem cell populations could essentially act as integratory sites for descending and ascending immune signals. For instance, these brainstem pathways may have significant implications not only for the regulation of central hypothalamic and extra-hypothalamic targets but also the autonomic nervous system.     

Doesn’t see,doesn’t know: is anticipatory looking really related to understanding or belief?

Clements and Perner (Cognitive Development, 9 (1994), 377–397) reported that children show understanding of a story character’s belief in their anticipatory looking responses before they show this in their answers to test questions. According to Clements and Perner the anticipatory looking responses provide evidence of implicit understanding of belief. This paper examines the possibility that the anticipatory looking measure is indicative of (a) children using a seeing = knowing rule, i.e. children linking not seeing with ignorance rather than a sensitivity to belief, or (b) a tendency to associate the protagonist with the left‐hand container. Thirty‐two children aged between 2 years 11 months and 4 years were told a false belief story similar to that used in Clements and Perner (1994) except that three containers were used instead of two. The protagonist first looks inside the middle box but then puts the object in the left‐hand box. In his absence, a second character moves the object unexpectedly to the right‐hand box. If children’s anticipatory looking was based on sensitivity to belief then they should have looked clearly to the left‐hand box. If it was based on an association bias or sensitivity to the character not knowing then they should have looked equally to the left‐hand and middle boxes. The results were consistent with the former prediction suggesting that children’s anticipatory looking responses may indeed be governed by an implicit sensitivity to belief.