Biochemical and endocrine aspects of oxytocin production by the mammalian corpus luteum

A review of the current state of knowledge of oxytocin production by the preovulatory follicle and corpus luteum is presented. Corpora lutea of a number of mammalian species have been found to synthesize oxytocin. However, the synthesis and secretion of this nanopeptide by the corpus luteum of the ruminant has been most extensively studied because of the potential role of this peptide in facilitating luteal regression. While much information exists relative to various biochemical and endocrine factors that impact on oxytocin gene expression, this aspect about luteal synthesis of this peptide hormone remains enigmatic. Prostaglandin F-2α (PGF-2α) has been shown to be a primary endogenous hormone responsible for triggering luteal secretion of oxytocin. Details are provided regarding the PGF-2α-induced intracellular signal transduction pathway that ultimately results in exocytosis of luteal oxytocin. Evidence is also presented for potential autocrine/paracrine actions of oxytocin in regulating progesterone production by luteal and granulosa cells. Concluding remarks highlight aspects about luteal oxytocin production that require further research

A brief measure of peer affiliation and social acceptance (PASA): Validity in an ethnically diverse sample of early adolescents

Objective Conduct a multiagent–multimethod analysis of the validity of a brief measure of deviant peer affiliations and social acceptance (PASA) in young adolescents. Peer relationships are critical to child and adolescent social and emotional development, but currently available measures are tedious and time consuming. The PASA consists of a youth, parent, and teacher report that can be collected longitudinally to study development and intervention effectiveness. Method This longitudinal study included 998 middle school students and their families. We collected the PASA and peer sociometrics data in Grade 7 and a multiagent–multimethod construct of deviant peer clustering in Grade 8. Results Confirmatory factor analyses of the multiagent–multimethod data revealed that the constructs of deviant peer affiliations and social acceptance and rejection were distinguishable as unique but correlated constructs within the PASA. Convergent, discriminant, concurrent, and predictive validity of the PASA was satisfactory, although the acceptance and rejection constructs were highly correlated and showed similar patterns of concurrent validity. Factor invariance was established for mother and for father reports. Conclusions Results suggest that the PASA is a valid and reliable measure of peer affiliation and of social acceptance among peers during the middle school years and provides a comprehensive yet brief assessment of peer affiliations and social acceptance

The early childhood generalized trust belief scale

The study was designed to develop and evaluate the Early Childhood Generalized Trust Belief Scale (ECGTBS) as a method of assessing 5-to-8-year-olds’ generalized trust. Two hundred and eleven (103 male and 108 female) children (mean age 6 years and 2 months at Time 1) completed the ECGTBS twice over a year. A subsample of participants completed the ECGTBS after two weeks to assess the scale’s test-retest reliability. Exploratory and confirmatory factor analyses confirmed that the ECGTBS assessed the expected three factors: reliability, emotional trust, and honesty with item-pairs loading most strongly on their corresponding factor. However, the ECGTBS demonstrated low to modest internal consistency and test-retest reliability which indicates a need for further development of this instrument. As evidence for the convergent validity of the ECGTBS, the reliability and emotional trust items were associated with the children’s trust in classmates at Time 2. Concurrent asymmetric quadratic relationships indicated the importance of midrange generalized trust. Specifically, children with very high generalized trust experienced greater loneliness and children with very low generalized trust had fewer friendships than children with midrange trust

Nuclear Progestin Receptor (Pgr) Knockouts in Zebrafish Demonstrate Role for Pgr in Ovulation but Not in Rapid Non-Genomic Steroid Mediated Meiosis Resumption

Progestins, progesterone derivatives, are the most critical signaling steroid for initiating final oocyte maturation (FOM) and ovulation, in order to advance fully-grown immature oocytes to become fertilizable eggs in basal vertebrates. It is well-established that progestin induces FOM at least partly through a membrane receptor and a non-genomic steroid signaling process, which precedes progestin triggered ovulation that is mediated through a nuclear progestin receptor (Pgr) and genomic signaling pathway. To determine whether Pgr plays a role in a non-genomic signaling mechanism during FOM, we knocked out Pgr in zebrafish using transcription activator-like effector nucleases (TALENs) and studied the oocyte maturation phenotypes of Pgr knockouts (Pgr-KOs). Three TALENs-induced mutant lines with different frame shift mutations were generated. Homozygous Pgr-KO female fish were all infertile while no fertility effects were evident in homozygous Pgr-KO males. Oocytes developed and underwent FOM normally in vivo in homozygous Pgr-KO female compared to the wild-type controls, but these mature oocytes were trapped within the follicular cells and failed to ovulate from the ovaries. These oocytes also underwent normal germinal vesicle breakdown (GVBD) and FOM in vitro, but failed to ovulate even after treatment with human chronic gonadotropin (HCG) or progestin (17α,20β-dihydroxyprogesterone or DHP), which typically induce FOM and ovulation in wild-type oocytes. The results indicate that anovulation and infertility in homozygous Pgr-KO female fish was, at least in part, due to a lack of functional Pgr-mediated genomic progestin signaling in the follicular cells adjacent to the oocytes. Our study of Pgr-KO supports previous results that demonstrate a role for Pgr in steroid-dependent genomic signaling pathways leading to ovulation, and the first convincing evidence that Pgr is not essential for initiating non-genomic progestin signaling and triggering of meiosis resumption

The effects of changes in the order of verbal labels and numerical values on children's scores on attitude and rating scales

Research with adults has shown that variations in verbal labels and numerical scale values on rating scales can affect the responses given. However, few studies have been conducted with children. The study aimed to examine potential differences in children’s responses to Likert-type rating scales according to their anchor points and scale direction, and to see whether or not such differences were stable over time. 130 British children, aged 9 to 11, completed six sets of Likert-type rating scales, presented in four different ways varying the position of positive labels and numerical values. The results showed, both initially and 8-12 weeks later, that presenting a positive label or a high score on the left of a scale led to significantly higher mean scores than did the other variations. These findings indicate that different arrangements of rating scales can produce different results which has clear implications for the administration of scales with children

Prenatal Influence of an Androgen Agonist and Antagonist on the Differentiation of the Ovine Sexually Dimorphic Nucleus in Male and Female Lamb Fetuses

The ovine sexually dimorphic nucleus (oSDN) is 2 times larger in rams than in ewes. Sexual differentiation of the oSDN is produced by testosterone exposure during the critical period occurring between gestational day (GD)60 and GD90 (term, 147 d). We tested the hypothesis that testosterone acts through the androgen receptor to control development of the male-typical oSDN. In experiment 1, pregnant ewes received injections of vehicle, androgen receptor antagonist flutamide, or nonaromatizable androgen dihydrotestosterone (DHT) propionate during the critical period. Fetuses were delivered at GD135. Both antagonist and agonist treatments significantly reduced mean oSDN volume in males but had no effects in females. Experiment 2, we analyzed the effect of treatments on the fetal hypothalamic-pituitary-gonadal axis to determine whether compensatory changes in hormone secretion occurred that could explain the effect of DHT. Pregnant ewes were injected with vehicle, flutamide, or DHT propionate from GD60 to GD84, and fetuses were delivered on GD85. Flutamide significantly increased LH and testosterone in males, whereas DHT significantly decreased both hormones. In females, LH was unaffected by flutamide but significantly reduced by DHT exposure. DHT significantly decreased pituitary gonadotropin and hypothalamic kisspeptin mRNA expression in males and females. These results suggest that androgen receptor mediates the effect of testosterone on oSDN masculinization, because this process was blocked by the androgen receptor antagonist flutamide in eugonadal males. In contrast, the reduction of oSDN volume observed after DHT exposure appears to be mediated by a negative feedback mechanism exerted on the hypothalamus to reduce LH and testosterone secretion. The reduced androgen exposure most likely accounted for the decreased oSDN volume. We conclude that, during the critical period, the male reproductive axis in long gestation species, such as sheep, is sufficiently developed to react to perturbations in serum androgens and mitigate disruptions in brain masculinization

The Trajectories of Adolescents’ Perceptions of School Climate, Deviant Peer Affiliation, and Behavioral Problems During the Middle School Years

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90306/1/jora763.pd

Self-Regulation Questionnaire (SRQ) in Spanish Adolescents: Factor Structure and Rasch Analysis

The Self-Regulation Questionnaire (SRQ) is an instrument employed to measure the generalized ability to regulate behavior. Self-regulation is related to the management of risk behaviors, such as drug abuse or anti-social behaviors. The SRQ has been used in young adult samples. However, some risk behaviors are increasing among adolescents. The aim of this study is to examine the psychometric properties of the SRQ among Spanish adolescents. While controlling for method effects, the data showed goodness of fit with the four-factor solution and 17 items (Goal setting, Decision making, Learning from mistakes, and Perseverance), and the four sub-scales were unidimensional according to the Rasch analysis. The Rasch model itself was shown to be reliable, but not at the level of persons. This means that the instrument was not sensitive enough to discriminate people with different self-regulation levels. These results support the use of the Spanish Short SRQ in adolescent samples. Some suggestions are made to improve the instrument, particularly in its application as a diagnostic tool

A brief parenting intervention to enhance the parent-child relationship in Hong Kong: Harmony@Home

published_or_final_versio

Parenting and child adjustment: a comparison of Turkish and English families

The links between parenting and child behaviour in cultural context have received increasing research attention. We investigated the effect of parenting on child adjustment using a multi-method design, comparing English and Turkish families. The socioeconomically diverse samples included 118 English and 100 Turkish families, each with two children aged 4–8 years. Mothers completed questionnaires as well as parent–child interaction being assessed using a structured Etch-a-Sketch task with each child separately. Children were interviewed about their relationships with their mothers using the Berkeley Puppet Interview. Multiple-group Confirmatory Analysis was used to test Measurement Invariance across groups, and a multi-informant approach was used to assess parenting. We found partial cross-cultural measurement invariance for parenting and child adjustment. Strikingly, the association between parenting and child adjustment was stronger among English families than Turkish families. Culturally distinct meanings of both parenting and child behaviour must be considered when interpreting their association