Psychoneuroimmunology and male infertility: A possible link between stress,coping and male immunological infertility

Abstract

This current study investigated a link between stress and coping with some male infertility problems via psychoneuroimmunological theories. The study was carried out on 77 males who came to a fertility clinic for sperm diagnosis. Appraisal and coping with stress reaction to negative life events and to infertility were related to non-sperm cells within the seminal plasma. Those men who had felt strained from external events and from problems of infertility, and had used emotional escape coping strategies, were more prone to have an immunosuppressed reaction, indicated by bacteria within their plasma. Those using task focused control strategies were more prone to have an immunostimulatory reaction, indicated by white blood cells, including in some cases, sperm destroying phagocytes suggesting a possible auto-immunity reaction. When the analyses were done separately on patients with known male fertility problems in comparison with those with unexplained infertility, the two opposing psychoneuroimmunological processes became more pronounced.     

The effects of preexposure-test and conditioning-test intervals on the magnitude of latent inhibition

Using the conditioned taste aversion paradigm, two experiments were conducted to examine the effects of the interval between preexposure and test and that between conditioning and test on the magnitude of latent inhibition. Experiment 1 revealed that the degree of latent inhibition was attenuated when rats were given a 21‐day interval between preexposure and test. It was also found that this attenuation was more marked in subjects which were given conditioning immediately after preexposure than those which were conditioned shortly before the test. Retention interval between preexposure and test was reduced to 12 days in Experiment 2, and exactly the same pattern of results as those found in Experiment 1 was obtained. These findings suggest that the memory of conditioning as well as that of preexposure decreases its retrievability after a long retention interval, although the former is more retainable than the latter.     

Evidence for Free Radical-Mediated Reduction of Lymphocytic 5′-Ectonucleotidase During Stress

Previously we showed that stress and depression could result in a 50% lowering of lymphocytic 5-ectonucleotidase (NT) which could be resolved by a diet high in antioxidants. This study suggested that high levels of free radicals mediated by stress/depression may be involved in lowering NT activities. The aim of the present study was to assess whether oxygen radicals could directly affect NT and whether excess free radicals generated in stress/depression may affect tissue ascorbate stores. Exam-stressed students and depressed patients were compared respectively to these students at low stress and depressed patients on high antioxidant intakes. In this study, NT correlated positively with tissue ascorbate stores. A range of antioxidants were tested as possible inhibitors of oxy radical interaction with NT using nitroblue tetrazolium reduction to for-mazan with superoxide anion. At physiological plasma concentrations, ascorbate inhibited this reduction but dehydroascorbate, tocopherol, retinol, selenium, urate, and reduced glutathione were ineffective. Superoxide anion directly reduced lymphocytic NT activity and this effect was reversed by either 100 molar ascorbate in vitro or a high antioxidant intake in vivo. In conclusion, the low NT activities and ascorbate stores found in stressed/depressed people appear to be mediated by higher levels of free radicals reported in these subjects. These conclusions are consistent with published reports of (1) normal NT levels in melancholic patients on high antioxidant diets; (2) heightened inflammatory reponses during stress/depression; (3) low serum levels of zinc in depressed patients.     

Choice with delayed and probabilistic reinforcers: effects of prereinforcer and postreinforcer stimuli.

In Experiment 1, pigeons' pecks on a green key led to a 5-s delay with green houselights, and then food was delivered on 20% (or, in other conditions, 50%) of the trials. Pecks on a red key led to an adjusting delay with red houselights, and then food was delivered on every trial. The adjusting delay was used to estimate indifference points: delays at which the two alternatives were chosen about equally often. Varying the presence or absence of green houselights during the delays that preceded possible food deliveries had large effects on choice. In contrast, varying the presence of the green or red houselights in the intertrial intervals had no effects on choice. In Experiment 2, pecks on the green key led to delays of either 5 s or 30 s with green houselights, and then food was delivered on 20% of the trials. Varying the duration of the green houselights on nonreinforced trials had no effect on choice. The results suggest that the green houselights served as a conditioned reinforcer at some times but not at others, depending on whether or not there was a possibility that a primary reinforcer might be delivered. Given this interpretation of what constitutes a conditioned reinforcer, most of the results were consistent with the view that the strength of a conditioned reinforcer is inversely related to its duration.     

Persistence of acquired behavioral control in the context of imprinting

Newly hatched Khaki Campbell ducklings (Anas platyrhynchos domesticus) were exposed to a moving object that immediately suppressed distress vocalizations occurring in a novel environment. The static visual and auditory features of this object acquired the ability to suppress distress vocalizations after eight 20-min sessions of exposure to the object in motion. The acquired suppressive properties of these features were found to persist throughout thirty 20-min sessions given over 10 days. During these sessions, the ducklings were continually exposed to the static features in the absence of visual movement. In a second experiment, the ability of these features in the absence of visual movement. In a second experiment, the ability of these features to serve as reinforcement for a pecking response was shown to persist for up to 56 hr. In one duckling, presentations of the static visual features did not maintain pecking behavior. However, it was shown that pecking responses could be re-instated in this duckling by introducing novel stimuli to the environment.     

条件性恐惧记忆消退的提取干预范式及其作用的神经机制

基于记忆再巩固理论的恐惧记忆提取干预范式被证明可以有效消退恐惧记忆, 能克服传统消退容易复发的缺点。该范式通过单独呈现条件刺激激活原有恐惧记忆, 使记忆重返不稳定状态, 随后在再巩固时间窗内实施干预则能改写原有记忆。目前该范式起作用的神经机制尚不明确, 本文在现有的人类研究和动物研究基础上, 总结了杏仁核、前额叶和海马三个脑区在提取干预过程中的作用, 以及该领域研究的争议点, 为之后的研究提供思路。     

认知重评对负性效价的抑制促进条件性恐惧消退

认知重评能有效降低个体对情感刺激的负性情绪体验, 但指导性认知重评在恐惧记忆治疗中效果存在争议。本文将认知重评范式与辨别式条件恐惧反应范式结合, 以效价和US预期值为指标, 探讨指导性认知重评训练对恐惧情绪习得和消退的影响效果。以低认知重评能力个体为被试, 在实验前24 h进行指导性认知重评训练。条件性恐惧任务为期2天, 第一天完成条件性恐惧的习得和消退任务, 第二天完成条件性恐惧的再消退任务。结果显示, 经过重评训练后个体在条件性恐惧任务中的恐惧情绪效价显著较低, 说明认知重评有效降低低认知重评能力个体在急性应激状态下的负性情绪体验。所有被试均成功完成辨别式条件性恐惧的习得和消退任务, 因此重评训练并不削弱个体对危险或者安全信息的辨别能力。但在条件性恐惧的消退过程中, 认知重评指导训练加快了恐惧消退, 且24 h后测得的条件性恐惧程度显著较低, 说明指导性重评提高了条件性恐惧记忆的消退效率, 并减弱了条件性恐惧的消退返回。     

Terrorism and Innocence

This paper begins with a discussion of different definitions of “terrorism” and endorses one version of a tactical definition, so-called because it treats terrorism as involving the use of a quite specific tactic in the pursuit of political ends, namely, violent attacks upon the innocent. This contrasts with a political status definition in which “terrorism” is defined as any form of sub-state political violence against the state. Some consequences of the tactical definition are explored, notably the fact that (unlike the political status definition) it allows for the possibility of state terrorism against individuals, sub-state groups and other states. But a major problem for the tactical definition is the account to be given of “the innocent.” In line with justwar thinking, the idea of “the innocent” is unpacked in terms of the concept of non-combatants and this in turn is treated as the category of those who are not prosecuting the harm that allows for a legitimate violent response. Problems with this approach are explored, with particular reference to criticisms made by Gregory Kavka. The recent drive to expand the class of those who may be legitimately attacked is subjected to scrutiny. Particular attention is paid to the role of “collective responsibility” and “deserving your government” in these arguments. This revised version was published online in June 2006 with corrections to the Cover Date.