The Effects of Perceived Stress on Reactions to Messages Designed to Increase Health Behaviors

This study examined the impact of perceived stress on responses to messages that encouraged the performance of health promotion and disease detection behaviors. It was hypothesized that increases in perceived stress would be associated with decreased processing of messages encouraging disease detection behaviors, and that increases in perceived stress would not effect the processing of messages encouraging health promotion behaviors. To test these hypotheses participants completed a perceived stress measure and then read a message that encouraged the performance of either a health promotion or a disease detection behavior. Then the participants were asked to indicate their agreement with the message and to attempt to recall the message. The results indicated that participants experiencing higher levels of perceived stress spent less time reading and recalled less of the messages about detection behaviors than of the messages about promotion behaviors. When participants were experiencing lower levels of perceived stress these differences disappeared.

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Changes of cerebral vasoactive intestinal polypeptide-and somatostatin-like immunoreactivity induced by noise and whole-body vibration in the rat

To clarify the role of vasoactive intestinal polypeptide (VIP) and somatostatin, somatropin-release inhibiting factor, (SRIF) neurons in the response to organisms to noise or whole-body vibration stress, VIP and SRIF-like immunoreactivity were determined in various regions of the rat brain following exposure for 90 min to noise (broad band, 102 dB) or whole-body vibration (20 Hz, 4.0 g). Both noise and whole-body vibration significantly increased VIP-like immunoreactivity in the amygdala. A significant reduction of VIP like immunoreactivity in the hippocampus was induced only by whole-body vibration. On the other hand SRIF-like immunoreactivity was decreased significantly in the hypothalamus and increased significantly in the amygdala by noise and whole-body vibration, respectively. The present findings would seem to indicate that the amygdalofugal VIP neural system is involved in regulating hypothalamic and pituitary hormone secretions in non-specific reactions to stress. Responses of hippocampal VIP and the amygdalofugal SRIF to whole-body vibration stress are assumed to be activated as specific reactions to the stress.     

骨质疏松对骨的粘弹性性质影响的实验研究

目的研究正常大鼠股骨和维甲酸所致大鼠骨质疏松股骨的压缩粘弹性性质,为临床提供生物粘弹性力学参数。方法选用175～245g,6月龄Wistar大鼠30只,随机分为正常对照组15只,模型组15只。对模型组大鼠每日灌服维甲酸(70mg·kg-1·d-1),实验动物于第12周末处死。取股骨进行压缩应力松弛、蠕变实验。结果得出了正常对照组和模型组股骨应力松弛,蠕变数据和曲线。对应力松弛蠕变实验数据进行归一化处理,得出归一化应力松弛函数、蠕变函数及曲线。结论模型组的7200s应力松弛、蠕变量指标显著低于正常对照组(P<0.05)。     

Hypertension risk factors and cardiovascular reactivity to mental stress in young men

Hypertension risk may be associated with increased pressor response to mental stress. However, studies using family history as a predictor of reactivity have obtained mixed results. We assessed cardiovascular responses to mental arithmetic stress (a 5-min serial subtraction task) in male medical students (n = 220) at three levels of hypertension risk based on parental history and the subject's systolic blood pressure (SBP): low (SBP < 125 mm Hg and 0 or 1 hypertensive parent), moderate (resting SBP ≥ 125 mm Hg or 2 hypertensive parents), or high (resting SBP ≥ 125 mm Hg and 1 or 2 hypertensive parents). High risk men showed the greatest blood pressure responses ( + 22/ + 16 mm Hg), while moderate and low-risk groups showed correspondingly smaller responses ( + 17/ + 13 and + 14/ + 11 mm Hg, p's < 0.02). Family history alone did not predict differential reactivity. This study replicates and extends our previous work suggesting the importance of using both family history and resting blood pressure level in determining future risk for hypertension in studies of cardiovascular reactivity in relation to hypertension risk in males.     

基于骨和无有机成分骨与羟基磷灰石压缩性能实验比较的强度分析

目的分析判定以珊瑚为基体,通过水热交换法制成的羟基磷灰石植入体内后的强度是否可以达到活体骨的水平。方法实验测量羟基磷灰石、含有机成分的骨、无有机成分的骨的压缩极限应力。通过对比羟基磷灰石、骨及无有机成分的骨的压缩强度差别,确定胶原纤维对骨压缩强度的作用,进而应用经验模型预估人造羟基磷灰石在一定空隙度(0.1～0.5)范围变化时的强度。结果羟基磷灰石、骨及无有机成分的压缩强度分别为14.1 GPa、207 GPa和31.7 GPa。结论去除骨中的有机成分后其压缩强度降低约80%。水热交换法制成的羟基磷灰石抗压强度可能高于骨内羟基磷灰石,这种骨替代材料植入体内后,随着骨和纤维组织在内部生长,其强度有可能达到活体骨的水平。     

Predictability of Individual Differences in Activation Processes in a Field Setting Based on Laboratory Measures

The predictability of individual differences in activation processes was investigated in a multi-method laboratory-field study. Male students of physical education (N=58) were examined under various emotionally activating and physically demanding conditions (mental arithmetic, reaction time, free speech, cold pressor test, bicycle ergometer). The assessment included multi-channel recordings of pre-start phases in an athletic stadium and performance on a 1000 m run. Basal heart rate was also recorded during sleep. This multi-situational assessment was repeated after three weeks, three months, and, for most (N=42) subjects, after one year. Significant relationships exist between scores from corresponding conditions of relaxation, anticipation, and performance of physical exercise. However, with the exception of heart rate, correlation coefficients are rather small and seem to be of questionable predictive validity. A generalizability study further supports the general conclusion: To increase the practical relevance in psychophysiological investigations of stress/strain phenomena, such studies should directly assess individual differences in the criterion situations themselves.     

Comparison of Frontal EMG Biofeedback and Several Types of Relaxation Instructions in Reducing Multiple Indices of Arousal

During the training phase, 96 subjects were given one of four types of relaxation instructions (single instructions, repeated instructions, relaxation training, no instructions) and in addition either did or did not receive frontal EMG biofeedback training. Results indicated that each of the instructions and biofeedback procedures were equally effective in reducing frontal EMG, but that none of these procedures had any effect on subjective anxiety or autonomic indices of arousal (pulse rate, skin temperature, and finger pulse volume). During the generalization/stress phase, subjects were threatened with electric shock and were told to apply the relaxation techniques they learned during the training phase even though no additional instructions and/ or biofeedback training would be provided. To assess the effectiveness of the shock manipulation, a no-threat control group was included. Results indicated that: a) the shock manipulation was effective in increasing arousal, b) previous instructions and/or biofeedback were equally effective in reducing frontal EMG levels, but that c) only relaxation training was consistently effective in reducing subjective and autonomic indices of arousal. These findings: a) suggest that in stressful situations, relaxation training may be more effective than either EMG biofeedback or simple relaxation instructions in producing a general relaxation effect as opposed to a specific EMG effect; and b) indicate the importance of assessing the effectiveness of relaxation procedures during stressful situations during which subjects’ levels of arousal are elevated above resting baseline levels.     

强迫症疾病行为的精神病理机制研究

目的对研究获得的强迫症疾病行为特征探索其精神病理学机制。方法以符合CCMD-Ⅱ的门诊强迫症患者50例为对象，选取非精神科病人50例组成对照，应用“强迫症疾病行为特征量表（OBPS）”，确定其有无强迫症疾病行为。同时调查研究组与对照组的人格特质、偶发事件、应对策略等方面，研究这些因素在疾病发生、发展中的作用。结果①研究组全部符合李一高量表的疾病行为特征，积分明显高于对照组（t=26．480，P〈0．01）；②强迫症患者人格当中的强迫质偏高，积分明显高于对照组（t=15．93，P〈0．01）；③研究组中绝大多数患者存在偶发事件，而对照组中偶发事件的发生率低于研究组（X^2=21．374，P〈0．01）；④应对策略特征方面研究组不成熟应对方式的应用明显多于对照组。结论强迫神经症形成中人格特质作为基础，偶发事件起到启动对“不完全的恐怖”，错误的应对策略不断强化病感，促进疾病形成。李一高强迫症疾病行为理论的3项内容，特征性的反映了强迫症的疾病行为。     

Heart Rate Reactivity and Type A Behavior as Modifiers of Physiological Response to Active and Passive Coping

We examined the long term predictivity of heart rate reactivity (HRR) and its relation to cardiovascular and biochemical activity during rest and during tasks requiring active and passive coping. HRR was determined in 28 young men by measuring peak heart rate change to cold pressor one year after performing tasks eliciting active and passive coping. Heart rate change to cold pressor was significantly correlated with change to active coping (r= .65, p<.01) and to passive coping (r= .53, p<.01). Responses to the tasks were equivalent for Type A and B subjects. On the other hand, high HRRs were significantly more reactive than low HRRs with the effect being most apparent during active coping. HRR appeared to be a trait stable over one year which predicted enhanced cardiac, neuroendocrine, and neuromuscular response.