Pilot Study of the Mastery Lifestyle Intervention.

BACKGROUND: Recognizing the effects of acculturation on quality of life and emotional health, especially during pregnancy, we developed an intervention that would target these factors in order to improve maternal well-being during the prenatal period and potentially improve infant outcomes, particularly preterm birth for Mexican-American women (Latinas). OBJECTIVE: The purpose of these pilot studies was to test the acceptability, feasibility, and preliminary efficacy of the mastery lifestyle intervention (MLI) to decrease depressive and anxiety symptoms and improve coping as implemented in prenatal clinics with culturally homogenous groups of Latinas. METHODS: The MLI was tested in three small pilot studies (n = 15), one in El Paso, Texas (an urban area), and two in Bastrop, Texas (a rural area outside Austin), for acceptability and feasibility. A pretest/posttest, quasi-experimental design was used with pregnant self-identified Mexican-American Latinas at 14-20 weeks' gestation. Measures of anxiety, depressive symptoms, and positive and negative coping were used. RESULTS: Feasibility was a success in terms of implementation of the MLI in an active prenatal clinic setting and the use of electronic tablets for data collection and entry of data into REDcap. Satisfaction was high, with the location of the MLI being at their primary OB/GYN clinic. Participants reported that six intervention sessions appear to be ideal as was the class length of 1.5 to 2 hours. On Cohen's d, there were medium to large effect size decreases in depressive and anxiety symptoms and small to medium effect size decreases in the use of negative coping strategies and small effect sizes for increases in positive coping strategies. DISCUSSION: Pilot testing of the MLI indicated that it was well accepted from the participants and feasible as a culturally tailored behavioral therapy administered in a group setting by nurse practitioners. Our initial pilot results also suggest preliminary efficacy as indicated by moderate to large Cohen's d effect sizes for depression and anxiety.

Micro RNA clusters in maternal plasma are associated with preterm birth and infant outcomes.

The current study examined micro RNA (miRNAs) clusters from the maternal plasma to determine their association with preterm birth (PTB) and infant birth outcomes. A subsample of 42 participants who spontaneously delivered either preterm (≤37 weeks) or term was selected from a parent sample of 515 pregnant Mexican American women. Plasma samples and prenatal data were collected at a single mid-gestation time point (22-24 weeks' gestation) and birth outcomes were obtained from medical records after delivery. Circulating miRNAs were analyzed by qPCR. When miRNAs were grouped according to chromosomal cluster rather than expression level, individual miRNAs correlated strongly with other individual miRNAs within their respective genomic locus. miRNAs from the c19mc cluster negatively correlated with c14mc miRNAs, and this relationship was more pronounced in PTB. Clusters c14mc was negatively associated with length of gestation; while the c19mc was positively associated with length of gestation and infant head circumference. Together, these findings suggest that groups of miRNAs from common chromosomal clusters, rather than individual miRNAs, operate as co-regulated groups of signaling molecules to coordinate length of gestation and infant outcomes. From this evidence, differences in cluster-wide expression of miRNAs are involved in spontaneous PTB.

Chronic social stress in puberty alters appetitive male sexual behavior and neural metabolic activity.

Repeated social subjugation in early puberty lowers testosterone levels. We used hamsters to investigate the effects of social subjugation on male sexual behavior and metabolic activity within neural systems controlling social and motivational behaviors. Subjugated animals were exposed daily to aggressive adult males in early puberty for postnatal days 28 to 42, while control animals were placed in empty clean cages. On postnatal day 45, they were tested for male sexual behavior in the presence of receptive female. Alternatively, they were tested for mate choice after placement at the base of a Y-maze containing a sexually receptive female in one tip of the maze and an ovariectomized one on the other. Social subjugation did not affect the capacity to mate with receptive females. Although control animals were fast to approach females and preferred ovariectomized individuals, subjugated animals stayed away from them and showed no preference. Cytochrome oxidase activity was reduced within the preoptic area and ventral tegmental area in subjugated hamsters. In addition, the correlation of metabolic activity of these areas with the bed nucleus of the stria terminalis and anterior parietal cortex changed significantly from positive in controls to negative in subjugated animals. These data show that at mid-puberty, while male hamsters are capable of mating, their appetitive sexual behavior is not fully mature and this aspect of male sexual behavior is responsive to social subjugation. Furthermore, metabolic activity and coordination of activity in brain areas related to sexual behavior and motivation were altered by social subjugation.

Interleukin-10 predicts preterm birth in acculturated Hispanics.

OBJECTIVE: Among Hispanics living in the United States, acculturation is associated with an increased risk for preterm birth. Inflammatory pathways are also associated with preterm birth. As such, the current study sought to investigate the potential relationships among preterm birth, acculturation of Hispanic women, and inflammatory markers. STUDY DESIGN: The authors performed an observational study on pregnant Hispanic women in Texas at 22-24 weeks' gestation (n = 470). The authors obtained demographic data prenatally as well as birth outcome data from the medical chart after delivery. The authors obtained venous blood and used plasma to assay interleukin-1 receptor antagonist (IL-1RA), interleukin-6 (IL-6), and interleukin-10 (IL-10). The authors used logistic regression to understand whether the presence or the absence of IL-10 levels was related to acculturation and the risk of preterm birth. RESULTS: The authors observed interactions between undetectable IL-10 levels and years in the United States and undetectable IL-10 levels and being born in the United States in models predicting preterm birth. Follow-up probes of these interactions suggested that when IL-10 was undetectable, preterm birth became more likely as time living in the United States increased, χ(2) = 5.15 (1, 416), p = .020, odds ratio (OR) = 3.17, and was more likely in participants born in the United States than in those born elsewhere, χ(2) = 5.35 (1, 462), p = .020, OR = 16.78. The authors observed no interactions among acculturation, preterm birth, and IL-1RA and IL-6 levels. CONCLUSION: Acculturated Hispanics who lack the protective effects of IL-10 experience a markedly higher risk of preterm birth than nonacculturated Hispanics.

Stress, aggression, and puberty: neuroendocrine correlates of the development of agonistic behavior in golden hamsters.

During puberty, agonistic behaviors undergo significant transitions. In golden hamsters, puberty is marked by a transition from play fighting to adult aggression. During early puberty, male golden hamsters perform play-fighting attacks. This response type is gradually replaced by adult attacks over the course of puberty. Interestingly, this behavioral transition does not appear to be controlled by changes in gonadal steroids. Instead, the shift from play fighting to adult aggression in male golden hamsters is driven by pubertal changes in glucocorticoid levels. Specifically, the transition from play fighting to adult aggression coincides with developmental increases in glucocorticoid levels, and external manipulations such as social stress or treatment with corticosteroid receptor agonists accelerate this behavioral shift. Moreover, the consequences of social stress differ greatly between juvenile and adult male golden hamsters. Although a single defeat during adulthood causes severe and long lasting behavioral and neuroendocrine consequences, socially subjugated juveniles show only transient behavioral effects. As such, it is likely that pubertal changes in the HPA axis are not only linked to the maturation of offensive responses but also determine the consequences of social stress. Combined, these studies in golden hamsters provide a novel mechanism for the development of agonistic behavior and suggest that age related differences in behavioral plasticity are mediated by the development of the HPA axis.

Cortisol controls the pubertal development of agonistic behavior in male golden hamsters via type II corticosteroid receptors.

In male golden hamsters, agonistic behavior undergoes a pubertal transition from play fighting to adult aggression. Previous studies have shown that this aspect of behavioral development is associated with pubertal increases in glucocorticoids and that daily social stress or injections of a synthetic glucocorticoid accelerate the transition. The goals of this study were to confirm the effects of cortisol on the development of agonistic behavior and to investigate the role of type II corticosteroid receptors in this process. First, animals treated with cortisol during early puberty [from postnatal days 31 (P-31) to P-36] showed an accelerated transition from play fighting to adult aggression. In a second experiment, the behavioral effects of cortisol were blocked by a co-treatment with a type II corticosteroid receptor antagonist. These findings are the first to show a facilitating role for type II corticosteroid receptors in the pubertal development of a social behavior. As such, these findings provide new insights into the neuroendocrine mechanisms controlling behavioral development during puberty.

Characterization of offensive responses during the maturation of play-fighting into aggression in male golden hamsters.

In hamsters, the maturation of aggression during puberty is associated with a gradual reduction of offensive responses. The purpose of this study was to analyze the changes during this decrease to provide an enhanced description of the behavior. During early puberty, play-fighting is characterized by long and continuous contact duration throughout the encounter and repetitive attacks within bouts of agonistic interaction. By mid-puberty, adult patterns of offensive behavior emerge. Contact time becomes shorter in duration and shifts to the beginning of the test, while attacks become less repetitive per bout. In late puberty, animals show an enhanced efficiency of behavior, as indicated by an increased percentage of attacks followed by bites. This study provides a better understanding of the development of aggression by characterizing the differences between juvenile play-fighting and adult aggression and the process of the maturation of aggression.

Stress and the development of agonistic behavior in golden hamsters.

Aggressive behavior can be studied as either offensive or defensive responses to a stimulus. The studies discussed in this review are focused on the peripubertal development of offensive aggression in male golden hamsters and its responsiveness to repeated social stress. Quantitative and qualitative changes in offensive responses were analyzed during this period. Quantitative changes in offensive responses were observed as decreased frequency of attacks. Qualitative changes were observed as changes in attack types, as animals reorient their attacks gradually from the face to the lower belly and rump. These developmental changes were altered by repeated exposure to social stress during early puberty. Daily exposure to aggressive adults during early puberty accelerated the qualitative development of offensive responses and the onset of adult-like offensive responses. In contrast, social stress had little effect on the quantitative changes associated with early puberty. However, social stress was associated with higher attack frequency during adulthood. These effects of stress during early puberty contrast with those observed with animals in late puberty. At that time, repeated exposure to aggressive adults inhibits offensive aggression. These data constitute the basis for a new theory on the development of agonistic behavior that includes the following hypotheses. First, it is hypothesized that mid-puberty is marked by a change in responsiveness to repeated social stress. As such, differences in stress responsiveness from social interactions are interpreted as a basic distinction between play fighting and adult aggression. Second, it is also hypothesized that a common neural circuitry mediates the activation of offensive responses during play fighting and adult aggressive interactions.

Repeated social stress and the development of agonistic behavior: individual differences in coping responses in male golden hamsters.

In male golden hamsters, repeated social subjugation during puberty accelerates the development of adult aggressive behavior and enhances its intensity in the presence of smaller individuals. The current study is focused on the characterization of the hormonal and behavioral responses to social subjugation during puberty. Subjugation consisted of daily exposure to an aggressive adult for 20-min periods from postnatal day 28 (P-28) to P-42, while controls were placed into an empty clean cage. Plasma cortisol levels were measured prior to or immediately after treatment on P-28 and P-42. On P-28, exposure to an aggressive adult or a clean and empty cage caused an increase in plasma cortisol levels. However, only social subjugation resulted in elevated cortisol levels on P-42, showing that juvenile hamsters habituate to an unfamiliar environment but not to social subjugation. In addition, we found a relationship between the frequency of submissive responses during social subjugation and the development of aggressive behavior. The transition from play fighting to adult aggression was most accelerated in the least submissive animals. These data show that behavioral response to social subjugation determines the development of aggressive behavior in golden hamsters. Our data also suggest that submissive behavior is a form of coping that attenuates the behavioral consequences of social subjugation in male golden hamsters.

Repeated exposure to social stress alters the development of agonistic behavior in male golden hamsters.

In male golden hamsters, exposure to social stress during puberty alters aggressive behavior. Interestingly, agonistic behavior undergoes two major transitions during puberty: a decline in attack frequency and a shift from play fighting to adult-like aggression. Based on previous observations, we developed an approach for characterizing offensive responses as play fighting or adult-like. The present studies had two aims. First, we validated our approach by looking at the development of attack types during puberty. Second, we looked at the effects of repeated social stress on the development of agonistic behavior by repeatedly exposing individuals to aggressive adults during puberty. In the first phase of the study, our results point to three different developmental periods. Initially, animals engage in agonistic behavior though attacks targeted at the face and cheeks. This period lasts from Postnatal Day 20 (P-20) to P-40 (early puberty). This phase corresponding to play fighting is followed by a transitional period characterized by attacks focused on the flanks (from P-40 to P-50, mid-puberty). Afterward, animals perform adult-like aggression characterized by attacks focused on the belly and rear. Our data also show that repeated exposure to aggressive adults has two separate effects on the development of agonistic behavior. Repeated social stress accelerated the onset of adult-like agonistic responses. Furthermore, attack frequency, while decreasing during puberty, remained at a higher level in early adulthood in stressed animals. These results show that repeated exposure to social stress during puberty alters the development of agonistic behavior both qualitatively and quantitatively.

Chronic social stress during puberty enhances tyrosine hydroxylase immunoreactivity within the limbic system in golden hamsters.

The present study was carried out to determine the effects of chronic exposure to social stress during puberty on the dopamine system in male golden hamsters. Experimental animals were socially subjugated between postnatal days 28 (P28) and 42. All animals were sacrificed on P46 and their brains processed for immunocytochemistry to tyrosine hydroxylase (TH). A large increase in the number of TH-immunoreactive (TH-ir) neurons was noted within the posterior portion of the medial amygdaloid nucleus and the posterior portion of the medial division of the bed nucleus of the stria terminalis in subjugated animals as compared to controls. This effect appeared to be site-specific as no difference was seen between groups in the periventricular nucleus, another steroid receptor-rich area. The data suggest that these dopamine neurons may play an important role in the behavioral changes associated with chronic social stress during puberty.