Biological Bases of Maternal Attachment

In recent years, there has been growing interest in investigating the processes affecting caregiving behavior. Recent studies of human and nonhuman primates have suggested that hormones can account, at least in part, for changes in caregiving motivation during pregnancy and the postpartum period and for variability in caregiving motivation and behavior among individuals. Although hormones may not be the primary determinants of caregiving, future research cannot afford to overlook the contribution that biological processes can make to normative and pathological attachment and parenting.     

The Impact of Exercise on Hormones Is Related to Autonomic Reactivity to a Mental Task

This study examined the effects of an acute physical stressor on salivary testosterone (Tsal) and cortisol (Csal) and their relationship with the autonomic responsiveness to a mental task in fit young men (n = 30). Salivary testosterone (Tsal) and cortisol (Csal) levels were determined before and after a maximal bicycle exercise. Heart rate (HR) and skin conductance levels (SCL) were continuously recorded before, during, and after a Stroop task. Tsal and Csal levels diminished while HR and SCL increased in response to stressors in all the sample. When subjects were distributed in function of their endocrine response to the physical stressor, high Tsal responders showed higher HR reactivity than low responders, and high Csal responders showed higher SCL reactivity and lower reaction time in the Stroop task. These results show that the influence of an acute physical stressor on hormones is associated with the autonomic responses to a mental task.     

心律失常发生的别差异

临盘床中某些心律失常的发生具有性别差异。女性同男性相比,其平均静息心率快,QT间期长,QRS波群时间短,QRS电压低。女性有更高的病态窦房结综合征、不适当性窦性心动过速、房室结折返性心动过速、右室特发性室速和长QT间期综合征引起的心律失常事件的发生率。而男性房室传导阻滞、颈动脉窦综合征、房颤、旁路导致的室上性心动过速、预激综合征、室颤、猝死、Brugada综合征和触发型室速的发生率高。这些差异有的与心律失常伴发的器质性心脏病男女发生率不同有关,另外性激素对离子通道的功能、表达的影响以及自主神经张力的差异在这些差异的产生中也具有重要作用。了解这些差异对女性心律失常处理具有重要的指导作用。     

From steroids to nation states: An integrated evolutionary approach to violent crime

Most evolutionary psychologists emphasize the individual level of analysis concerning violent crime and other dependent variables. This paper outlines a strategy for evolutionary explanation of societal variation across time as well as space and applies it to crimes of violence. The central idea is that individual adaptations for reproductive competition play out differently depending both on developmental context and societal conditions, including the marriage market. Violent crimes (murders, rapes, and assaults) are substantially higher in countries with a relative scarcity of men according to research using INTERPOL and World Health Organization data [Barber, N. (2000a). The sex ratio as a predictor of cross-national variation in violent crime. Cross-Cultural Research, 34, 264–282, Barber, N. (2009). Countries with fewer males have more violent crime: Marriage markets and mating aggression. Aggressive Behavior, 35, 49–56]. This is an apparent contradiction given that males are more criminally violent and likely reflects increased direct mating competition that evokes increased testosterone production for humans as for other species. The empirical evidence is discussed in terms of direct reproductive competition and various alternative explanations, particularly the “culture of violence” and socialization experiences are considered.     

Behavioral and endocrine aspects of dominance and submission in male rabbits

Small all-male groups of rabbits were studied for periods of 15–20 days in a seminatural setting, giving the animals the possibility of initiating and pacing their social interactions. Behavioral observations included: intermale activity recorded daily and the reactions to the occasional introduction of an intruder female. Hormones were measured in blood samples taken at the beginning and at the end of the experimental period. A combination of behavioral and endocrine parameters, rather than single measures, was used to assign each individual its social rank within each group. Tables of concordance between behavioral and endocrine parameters were compiled to evaluate the dominance and the subordination hierarchy. Different behavioral categories and elements characterized dominance and subordination, indicating the two as district rather than simply reciprocal traits. Their endocrine basis is also different, final levels of testosterone and estradiol being associated with dominance, and corticosterone, ACTH, and androstenedione with subordination. The same hormones in the initial samples were unrelated to the subsequent social status, indicating that hormones are not prerequisites of status. The relevance of specific behavioral and endocrine parameters is discussed.     

Activation of intermale aggression by combined estrogen-androgen treatment

Adult CD-1 male mice were gonadectomized and tested for their response to the aggression-promoting property of androgens, estrogens, or combined androgen-estrogen treatment. The results showed that the combined treatment was the most effective, although androgens alone were sufficient for behavioral restoration. These findings suggest that testosterone may activate aggression through both its androgenic and estrogenic metabolites.     

Some consequences of aggressive behavior: A selective review of the literature on other animals

Animal experiments in which the opportunity to aggress was positively reinforcing are surveyed, with attention paid to field and laboratory reports on play and play fighting. A distinction is drawn between ways in which aggressive behavior may be elicited and factors which increase or decrease the probability that aggression will be emitted. Since aggression may be emitted and may also be reinforcing, the possibility that aggressive behavior may be self-reinforcing is mentioned. In addition to positive reinforcement, consequences of aggressive behavior are presented. These include punishment, removal of a noxious stimulus, feeding, arousal, and disinhibition.     

Accelerated muscle contractility and decreased muscle steadiness following sauna recovery do not induce greater neuromuscular fatigability during sustained submaximal contractions

Acute whole-body hyperthermia (WBH) increases blood markers concentration of stress, impairs motor drive to exercising muscles, and decreases resistance to neuromuscular fatigability. The functional natural residual consequences of WBH on neuromuscular functions remain unclear. We aimed to investigate the effects of residual WBH on voluntary and electrically induced ankle plantar flexor contractility properties, motor drive transmission (reflexes), muscle torque steadiness, resistance to neuromuscular fatigability, and markers of stress as the body temperature recovers naturally to normothermia. WBH was induced by Finnish sauna bathing in 16 apparently healthy young (24 ± 4 years) adult men. Motor performance was monitored before and 2 h after the sauna, and immediately after submaximal exercise (120 s at 50% of maximal voluntary contraction). Markers of stress were monitored before and 2 h after the sauna. Finnish sauna exposure induced moderate to severe WBH (rectal temperature, 38.5–39.6 °C). At 2 h after the sauna, rectal temperature had recovered to the preheating level (preheating 37.11 ± 0.33 °C versus postheating 37.00 ± 0.29 °C, p > .05). Post-sauna recovery was accompanied by slowed salivary free cortisol diurnal kinetics, whereas noradrenaline, dopamine, and serotonin did not persist into the 2 h recovery after the sauna. Although recovery to normothermia after a sauna led to a greater acceleration of muscle contractility properties and decreased muscle steadiness, sustained isometric submaximal contraction did not provoke greater neuromuscular fatigability.     

关于甲状腺结节处理的一些思考

人群中甲状腺结节发病率很高,多数均为良性病变,但需要结合病史、临床症状、体征、甲状腺功能检查、超声及甲状腺细针抽吸细胞学(FNAC)检查,以排除恶性肿瘤。针对无恶性征象的甲状腺结节患者可以定期随访,必要时行外科手术治疗。     

Prenatal sex hormones and human aggression: A review,and new data on progestogen effects

We review data on aggression from psychological studies of offspring from two categories of abnormal prenatal sex hormone conditions: 1) endocrine disorders, and 2) hormone treatment during pregnancy. Both sources yield trends and some significant findings that are in line with the animal research based expectations of a positive androgen effect on the development of aggressive behavior. However, the available studies have many methodological weaknesses, and the results are not strong and open to interpretations by factors other than prenatal hormones. Potential modes of prenatal sex hormone effects are also discussed. In the second part, we present data on 13 boys and 15 girls who had been exposed to medroxyprogesterone acetate (MPA) in utero and on 28 closely pair-matched controls. The double-blind follow-up examination at age 9 to 14 years included questionnaires, half-structured interviews with mother and child separately, and a battery of psychological tests. Interviews were tape-recorded and rated by two independent raters. The results show weak but consistent differences, with the MPA-exposed subjects being lower in self- or mother-reported aggression than the controls. The results cannot be accounted for by differences in aggression-related rearing styles. However, the influence of pregnancy pathology cannot be totally excluded. We conclude that the available data are compatible with the hypothesis that prenatal sex hormones influence the development of human aggressive behavior. More sophisticated research studies are needed, however, to demonstrate hormonal effects and their mechanism of action in a reliable and valid fashion.