Sex Differences in Neonatal Stress Reactivity

The question of whether a sexually dimorphic stress reaction exists prior to extensive socialization was addressed by examining sex differences in physiological and behavioral stress reactivity, in healthy, term neonates, after a mildly stressful behavioral assessment procedure. The Neonatal Behavior Assessment Scale (NBAS; Brazelton, 1973) was administered to 18 male and 18 female neonates. Heart rate (HR), salivary cortisol, and behavioral states were assessed before and after the exam. Sex differences included higher cortisol response in males and a greater change in HR and higher NBAS motor performance cluster score in females. Salivary cortisol, HR change, NBAS cluster scores, and behavioral states after NBAS provided 100% discrimination between male and female infants. These findings suggest that there are neonatal sex differences in behavioral and physiological stress reactivity prior to socialization.     

Response-independent habituation of the orienting response in the preweanling rat

The effect of pattern of stimulus presentation on habituation of the cardiac component of the orienting response to an auditory stimulus was investigated in four experiments. The duration of stimulus presentation was held constant, but some animals were given six 10-sec stimulus presentations and others were given a single 60-sec stimulus. During the first 10 sec of the auditory stimulus, heart rate (HR) decreased approximately 40 beats per minute (bpm) in both groups, but during subsequent 10-sec epochs, the changes in HR were markedly different in the two groups. For those animals given a single 60-sec stimulus, the cardiac orienting response did not habituate; that is, HR either continued to decrease or remained approximately 40 bpm below baseline. In contrast, those animals given six 10-sec stimulus presentations showed smaller decreases in HR with each successive stimulus presentation, and after approximately four presentations, no detectable change in HR was observed. Despite these dramatic differences in habituation of the cardiac component of the orienting response, neither group oriented to the auditory stimulus when it was presented again following a short retention interval. Moreover, with increasing retention intervals, both groups showed the same forgetting function (reappearance of the orienting response). The implications of these findings for theories of the orienting response as well as theories of habituation are discussed.     

急性ST段抬高型心肌梗死继发心脏破裂的预测因素分析

研究目的：心脏破裂是急性ST段抬高型心肌梗死最严重的并发症之一,病情凶险,死亡率高。通过明确心肌梗死后出现心脏破裂并发症的危险因素,早期识别心脏破裂高危人群,有利于在急性心肌梗死的早期采取干预措施以减少心脏破裂的发生。创新要点：既往缺乏对中国sT段抬高型心肌梗死继发心脏破裂的系统风险评估,本研究采用回顾性队列研究的方法,完善并健全中国多中心的急性心肌梗死数据库,样本总量达到9798例,为国内同类研究中样本量最多。既往的国外文献报道：女性、高龄、心梗后就诊时间延迟、前壁心肌梗死、溶栓治疗等是心肌梗死后心脏破裂的独立危险因素。本研究在中国人群验证以上危险因素的基础上首次提出就诊时血色素下降及白细胞计数的升高与随后发生的心脏破裂密切相关。新的心脏破裂预测因素的发现有利于对心脏破裂更精细化的危险分层,早期识别心脏破裂高危人群。研究方法：建立中国多中心心肌梗死数据库,比较发生心脏破裂与未发生心脏破裂患者临床特点的差异,筛选敏感特异的心脏破裂的独立预测因素。重要结论：中国人群急性ST段抬高型心肌梗死后心脏破裂的发生率是1．82％,独立预测因素主要包括：高龄、女性、就诊时静息心率增快、前壁心肌梗死、心功能不全、就诊时间延迟、肾功能不全、贫血与白细胞计数升高。本文第一次提出就诊时贫血状态及白细胞计数的升高时与心脏破裂的发生直接相关。     

Maternal responsiveness and child compliance: the role of mood as a mediator

Parpal and Maccoby demonstrated that responsive maternal play increases children's compliance. They suggested that positive mood induction might be one mechanism mediating this effect. Study 1 tested the hypothesis that a responsive maternal play procedure would indeed induce a positive mood. 32 4-year-olds and their mothers participated. Half of the mothers were trained in a responsive play technique prior to a laboratory play session; half of them were not trained. Postplay self-reports of mood indicated that responsive play increased positive mood but did not affect arousal levels. Study 2 tested the hypothesis that experimentally induced positive mood increases compliance in the types of tasks reported in the Parpal and Maccoby's research. 24 4-year-olds were randomly assigned to either a positive or negative mood induction and then tested for response to maternal compliance demands. Children induced into positive moods complied more and complied with shorter latencies than children induced into negative moods. The fact that maternal responsiveness induces a positive mood points to a mechanism that may be significant in both attachment and socialization beyond infancy.     

Fetal Neurobehavioral Development

The ontogeny of fetal autonomic, motoric, state, and interactive functioning was investigated longitudinally in a sample of 31 healthy fetuses from 20 weeks through term. Fetal heart rate and movement data were collected during 50 min of Doppler-based fetal monitoring at 6 gestational ages. Measures of fetal heart rate and variability, activity level and vigor, behavioral state, and reactivity were derived from these digitized data. Weighted least squares analyses were conducted to model the developmental patterns and to examine the role of maternal and fetal covariates. With advancing gestation, fetuses displayed slower heart rate, increased heart rate variability, reduced but more vigorous motor behavior, coalescence of heart rate and movement patterns into distinct behavioral states, and increasing cardiac responsivity to stimulation. Male fetuses were more active than female fetuses, and greater maternal stress appraisal was associated with reduced fetal heart rate variability. An apparent period of neurobehavioral transition exists between 28 and 32 weeks. Fetal research methods are evaluated.     

Extended visual fixation and distractibility in children from six to twenty-four months of age

Distractibility during extended visual fixations in children 6 months to 2 years of age was examined. A children's Sesame Street movie (Follow That Bird) was presented to children (N = 40) for a minimum of 20 min while fixation was videotaped and heart rate was recorded. Distractors (computer-generated patterns or another Sesame Street movie) were presented on an adjacent television screen. Consistent with prior research with older preschool-age children, the latency to turn toward the distractor was a function of the length of the look occurring before distractor onset. For the period immediately before distractor onset, children had a greater sustained lowered heart rate for the trials on which they continued looking at the center television monitor than for the trials on which they looked toward the distractor. This pattern of distractibility suggests attention increases over the course of a look toward the television, and that heart rate changes reflect this increase in attention.     

Children''s Relationships with Maternal Grandparents: A Longitudinal Study of Family Structure and Pubertal Status Effects

This longitudinal study assessed the effects of parents' marital transitions and pubertal development on grandparent-grandchild relationships. 9- to 13-year-old children, their mothers, and maternal grandparents from 186 Caucasian, middle-class families including 73 intact families, 64 mother-custody, single-parent families and 49 stepfamilies completed questionnaires focusing on the degree of children's "relationship involvement" (perceived closeness and frequency of contact) with maternal grandparents at 2 time periods 13 months apart. Children also completed questionnaires 9 months later during a third interview. Grandparents, and especially grandfathers, were more involved with grandchildren from single-parent families (supporting the "latent function" hypothesis). The pubertal status results supported the "emotional distancing" hypothesis for grandfather-granddaughter relationships (higher pubertal status, less involvement) and the "stress buffer" hypothesis for grandsons' relationships with both grandparents (greater change in physical development, more involvement and greater perceived closeness).     

Fetal cardiac responding: a correlate of birth weight and neonatal behavior

Certain intrapartum fetal heart-rate (FHR) patterns are associated with low Apgar scores and other neonatal risks. Intrapartum FHR has been the subject of extensive clinical investigation, but only occasional reference is made to the possible behavioral correlates of this phenomenon. The current investigation found that neonates classified as FHR decelerators had lower birth weights and shorter gestational ages than FHR accelerators. Decelerators exhibited higher baseline heart rate and experienced more frequent uterine contractions than accelerators. Neurobehavioral assessment of these neonates indicated that decelerators had more abnormal reflex ratings and were less behaviorally organized than heart-rate accelerators. The results indicate that FHR responses are associated with prenatal growth, maturity, and possibly stress tolerance, and that intrapartum FHR responses be related to nonoptimal neonatal behavior.     

Maternal Stress and Sensitivity: Moderating Effect of Positive Affect

Objective. Stress felt by parents is often negatively related to their ability to engage in optimal parenting; however, research on relations of parenting stress to parenting behaviors typically examines negative associations instead of taking a strengths-based approach. The current study examines longitudinally the role of positive affect as a moderator of the relation of parenting stress to later maternal sensitivity, controlling for prior levels of sensitivity. Design. Maternal positive affect and maternal sensitivity were observed for 93 mother–child dyads during free-play sessions when children were 4- to 5-years-old (T1) and 8- to 9-years-old (T2), respectively. Mothers reported on parenting stress felt from dysfunctional parent–child interactions (T1). Results. Maternal positive affect moderated the association of parenting stress to sensitivity at T2, after controlling for prior levels of sensitivity at T1. Mothers who exhibited low positive affect were less likely to respond sensitively at T2 to their children when parenting stress was high; however, no association was found when positive affect was high. Conclusions. Maternal positive affect may buffer the effect of parenting stress on maternal sensitivity with school-aged children.     

Explaining Constrains Causal Learning in Childhood

Three experiments investigate how self‐generated explanation influences children's causal learning. Five‐year‐olds (N = 114) observed data consistent with two hypotheses and were prompted to explain or to report each observation. In Study 1, when making novel generalizations, explainers were more likely to favor the hypothesis that accounted for more observations. In Study 2, explainers favored a hypothesis that was consistent with prior knowledge. Study 3 pitted a hypothesis that accounted for more observations against a hypothesis consistent with prior knowledge. Explainers were more likely to base generalizations on prior knowledge. Findings suggest that attempts to explain drive children to evaluate hypotheses using features of “good” explanations, or those supporting generalizations with broad scope, as informed by children's prior knowledge and observations.     

Disruptive Behaviour in Non-Referred Mainstream School Children,Aged Seven to Nine: A psychophysiological contribution

Data are summarised relating resting heart/pulse rate to teachers' ratings of disruptive behaviour in a sample of 206 non-referred children, aged 7-9 years, attending mainstream schools and not subject to specialist attention. Low base heart rate (BHR) was found to be associated with teachers' ratings of disruptive behaviour, confirming similar earlier research based on children aged 11-16 years. The findings are discussed in relation to psychophysiology and child development and with reference to several theoretical frameworks, identifying the need for further research.     

Heart Rate and Behavioral measures of Attention in Six-, Nine-, and Twelve-Month-Old Infants during Object Exploration

In this study we examined the effect of heart rate and behavioral measures of attention on distractibility of 6-, 9-, and 12-month-old infants. The infants were presented with a toy, and a distractor was presented while they attended to the toy. The distractor was presented during heart rate changes indicating sustained attention or attention termination, or during periods of time when behavioral ratings indicated the infant was in focused or casual attention. There were longer distraction latencies during attentional engagement as defined by heart rate changes or behavioral ratings than for periods of inattention. Infants had the longest distraction latencies when heart rate and behavior measures were congruent with respect to attention engagement (heart rate deceleration and focused attention). Conversely, latencies were shortes for congruent values of inattention (heart rate acceleration and casual attention). Infant information processing may be greatest when a heart rate deceleration occurs simultaneously with an episode of focused attention.     

The relationship between sexual abuse during childhood and parenting outcomes: modeling direct and indirect pathways

OBJECTIVE: This study examined the association between childhood sexual abuse (CSA) and parenting outcomes including parenting stress, feelings of competence and discipline strategies. Maternal depression and current partner violence were hypothesized to be mediators of the association between CSA and parenting. METHOD: This study is based on secondary data analysis of archived data. The participants were 263 primiparous mothers (107 with a history of CSA and 156 comparison mothers recruited from a prenatal clinic prior to the birth of their first child. Mothers were interviewed twice: once when they were between 28 and 32 weeks gestation and again when their child was between 2 and 4 years of age. During the first interview, women were asked about childhood experiences of sexual abuse. During their second interview, they were asked about current symptoms of pathology and experiences with partner violence and parenting beliefs and practices. RESULTS: Structural Equation Modeling indicated that the relationship between CSA and punitive discipline was mediated by maternal depression and current partner violence. CSA was associated with higher maternal depression and higher partner violence. CSA, maternal depression, and current partner violence were associated with more negative parental perceptions and higher punitive discipline. Once maternal depression and current partner violence were in the model, the relationship between CSA and parenting outcomes was no different from zero. CONCLUSION: These results highlight the risks associated with CSA for parenting outcomes and suggest two potential pathways for this increased risk.     

The Relations of Maternal Practices and Characteristics to Children''s Vicarious Emotional Responsiveness

This study examined the relations of maternal vicarious emotional responding and child-rearing practices, as well as familial emotional environment, to 5-6 and 8-9-year-old children's vicarious emotional responding. There were some correspondences between mothers' and children's heart rate, facial, and self-reported reactions to a sympathy-inducing film. Maternal sympathy/perspective taking and reinforcement of sympathy/prosocial behavior, as well as negative subordinate emotion in the home, were associated with markers of girls' sympathy; mothers' personal distress (for girls), restrictiveness regarding displays of hurtful negative emotions (particularly for young girls), and negative dominant emotion in the home (for both sexes) were associated with markers of personal distress. Mothers' linking of the film character's experience to children's own experience was associated with children's responsiveness to the film, and mother's verbalizations during the film concerning her own emotional state and role taking were associated with boys' self-reported sympathy.     

Similarities and Differences in Behavioral State Organization during Sleep Periods in the Perinatal Infant Before and After Birth

The purpose of this study was to determine the degree of consistency in behavioral state organization for 30 low-risk human participants examined as fetuses at 38–40 weeks gestation and again as neonates at approximately 2 weeks postnatal age. behavioral states were assigned similarly for fetuses and neonmates in terms of heart rate pattern and the presence or absence of eye and gross body movements. We found that the time spent in a sleep period was distributed among quiet sleep (QS), active sleep (AS), and indeterminate states in virtually identical proportions for fetuses and neonates. However, the only within-subject consistency between the fetal and neonatal periods was in the duration of complete QS epochs. Fetuses made fewer transitions between QS and AS, but neonates had shorter and more structured AS → QS transitions. These findings suggest that, whereas central nervous system processes governing QS do not change appreciably, the control of AS undergoes significant changes in the 4 weeks spannig the fetal and neonatal periods. We believe that the duration of enclosed QS epochs provides the only stable measure of behavioral state development between the prenatal and postnatal periods.     

Maternal perinatal risk factors and child abuse

A retrospective matched pair study was designed to compare maternal perinatal factors such as abnormal pregnancy history and labor and delivery experience in families who subsequently were reported as physically abusive to one or more of their children as compared to non-abusive families. The study population consisted of the mothers of 532 children reported to the Baltimore (Maryland) Department of Social Services as physically abused during the years 1975-77. The comparison group was handmatched to the study group from State of Maryland birth certificates on the basis of the abused child's birth year and sex, maternal race, education and hospital of delivery. The study population was 67% black with a mean maternal education of 10.5 completed years. The abused children were 59% male with 48% less than 2 years of age. Results indicated that selected medical definitions of abnormal pregnancy, labor and delivery did not identify families at differential risk of maltreatment. However, mothers in maltreating families were younger, had shorter birth intervals, less prenatal care and were significantly more likely to have had a stillbirth or reported abortion or a prior child death. Study limitations are addressed as are suggestions for future research.     

Angiopoietin-1 preconditioning enhances survival and functional recovery of mesenchymal stem cell transplantation

Objective

Mesenchymal stem cell (MSC) transplantation is a promising therapy for ischemic heart diseases. However, poor cell survival after transplantation greatly limits the therapeutic efficacy of MSCs. The purpose of this study was to investigate the protective effect of angiopoietin-1 (Ang1) preconditioning on MSC survival and subsequent heart function improvement after transplantation.

Methods

MSCs were cultured with or without 50 ng/ml Ang1 in complete medium for 24 h prior to experiments on cell survival and transplantation. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and Hoechst staining were applied to evaluate MSC survival after serum deprivation in vitro, while cell survival in vivo was detected by terminal deoxynucleotidyl transferase biotin-dUPT nick end labeling (TUNEL) assay 24 and 72 h after transplantation. Heart function and infarct size were measured four weeks later by small animal echocardiography and Masson??s trichrome staining, respectively.

Results

Ang1 preconditioning induced Akt phosphorylation and increased expression of Bcl-2 and the ratio of Bcl-2/Bax. In comparison with non-preconditioned MSCs, Ang1-preconditioned cell survival was significantly increased while the apoptotic rate decreased in vitro. However, the PI3K/Akt pathway inhibitor, LY294002, abrogated the protective effect of Ang1 preconditioning. After transplantation, the Ang1-preconditioned-MSC group showed a lower death rate, smaller infarct size, and better heart functional recovery compared to the non-preconditioned-MSC group.

Conclusions

Ang1 preconditioning enhances MSC survival, contributing to further improvement of heart function.     

Classically conditioned heart rate in rats following preconditioning exposure to the CS

The influence of preexposure to the CS on classically conditioned heart rate was examined in three groups of rats receiving either 0, 10, or 50 CS-alone trials prior to the beginning of acquisition training. The conditioned response was a deceleration in heart rate for all groups. Compared to the 50 group, the 0 and 10 groups both showed a lower overall level of conditioning performance and a slower rate of development of the conditioned response. It was suggested that the presence of the nonhabituated orienting response may have interfered with the conditioning process.     

Effects of maternal absence due to employment on the quality of infant-mother attachment in a low-risk sample

Recent reports have suggested that day-care experience initiated prior to 12 months of age is associated with increased proportions of infants whose attachment to mother is classified as "insecure-avoidant." However, reviewers have questioned the generality of these findings, noting that samples in which associations between early day-care experience and avoidant attachment patterns have been reported come from high-risk populations, and/or that the infants' day-care settings may not have been of high quality. In the present study, effects of maternal absences on infant-mother attachment quality were assessed in a low-risk, middle-class sample (N = 110). In all instances, substitute care had been initiated at least 4 months prior to the infant's first birthday and was provided in the infant's home by a person unrelated to the baby. Infants were assessed using the Ainsworth Strange Situation when they were 12-13 months of age. Analyses indicated that a significantly greater proportion of infants whose mothers worked outside the home (N = 54) were assigned to the category "insecure-avoidant" as compared to infants whose mothers remained in the home (N = 56) throughout the first year of life. Analyses of demographic and psychological data available for the sample indicated that this relation is dependent upon maternal parity (primi- vs. multiparous mother). The association between attachment quality and work status was significant only for firstborn children of full-time working mothers. The results are interpreted as evidence that the repeated daily separations experienced by infants whose mothers are working full-time constitute a "risk" factor for the development of "insecure-avoidant" infant-mother attachments.     

解脲脲原体在三种培养基中生长情况的对比观察

目的:探讨解脲脲原体的最适培养基。方法:使用牛心浸液、牛肉汤和PPLO三种培养基,对解脲脲原体标准菌株及128份男性不育患者精液标本进行解脲脲原体的培养及生长情况的观察。结果:解脲脲原体在三种培养基均能生长,128份标本中阳性率分别为牛心浸液培养基57.0％、PPLO55.6％及牛肉汤45.2％;牛心浸液与PPLO培养解脲脲原体无显著性差异,与牛肉汤培养基有显著性差异。结论:牛心浸液培养基是一种较适合解脲脲原体生长且具有较高敏感性的培养基。