Transgenerational modification of dopaminergic dysfunctions induced by maternal immune activation

Prenatal exposure to infectious and/or inflammatory insults is increasingly recognized to contribute to the etiology of psychiatric disorders with neurodevelopmental components. Recent research using animal models suggests that maternal immune activation (MIA) can induce transgenerational effects on brain and behavior, possibly through epigenetic mechanisms. Using a mouse model of MIA that is based on gestational treatment with the viral mimeticpoly(I:C) (= polyriboinosinic-polyribocytidilic acid), the present study explored whether the transgenerational effects of MIA are extendable to dopaminergic dysfunctions. We show that the direct descendants born to poly(I:C)-treated mothers display signs of hyperdopaminergia, as manifested by a potentiated sensitivity to the locomotor-stimulating effects of amphetamine (Amph) and increased expression of tyrosine hydroxylase (Th) in the adult ventral midbrain. In stark contrast, second- and third-generation offspring of MIA-exposed ancestors displayed blunted locomotor responses to Amph and reduced expression of Th. Furthermore, we found increased DNA methylation at the promoter region of the dopamine-specifying factor, nuclear receptor-related 1 protein (Nurr1), in the sperm of first-generation MIA offspring and in the ventral midbrain of second-generation offspring of MIA-exposed ancestors. The latter effect was further accompanied by reduced mRNA levels of Nurr1 in this brain region. Together, our results suggest that MIA has the potential to modify dopaminergic functions across multiple generations with opposite effects in the direct descendants and their progeny. The presence of altered DNA methylation in the sperm of MIA-exposed offspring highlights the possibility that epigenetic processes in the male germline play a role in the transgenerational effects of MIA.Subject terms: Neuroimmunology, Developmental disorders     

Early relationships and marriage in conflict and post-conflict settings: vulnerability of youth in Uganda

While there is increased attention to child marriage, defined as marriage before 18 years of age, in countries where the practice is especially prevalent, less attention has been directed at understanding the factors affecting relationships, marriage and cohabitation among adolescents affected by conflict and displacement. This article presents factors which contribute to early relationships and informal marriages in conflict and post-conflict settings, based on qualitative research undertaken among two distinct populations in Uganda: internally displaced persons in Mucwini transit camp in northern Uganda and Congolese refugees in the Nakivale refugee settlement in southwestern Uganda. Themes were examined through a social–ecological framework. Findings indicate that fundamental shifts in economies, family relationships, and communication combined with structural changes encountered in settlements resulted in changed relationships and marriage patterns. Participants reported that poverty, splintering of family, and lack of education – which they believed to be exacerbated by conflict in both settings – had profoundly affected the views, perceptions and behaviours of youth around relationships and marriage. We identify interventions applicable to humanitarian settings that would offer refugee and internally displaced adolescents greater and more meaningful opportunities for development.     

Enhanced Human Neutrophil Vitamin C Status,Chemotaxis and Oxidant Generation Following Dietary Supplementation with Vitamin C-Rich SunGold Kiwifruit

Neutrophils are the body’s primary defenders against invading pathogens. These cells migrate to loci of infection where they engulf micro-organisms and subject them to an array of reactive oxygen species and antimicrobial proteins to effect killing. Spent neutrophils subsequently undergo apoptosis and are cleared by macrophages, thereby resolving the inflammatory episode. Neutrophils contain high concentrations of vitamin C (ascorbate) and this is thought to be essential for their function. This may be one mechanism whereby vitamin C enhances immune function. The aim of our study was to assess the effect of dietary supplementation with vitamin C-rich SunGold kiwifruit on four important functions of neutrophils: chemotaxis, oxidant generation, extracellular trap formation, and apoptosis. Fourteen young men (aged 18–30 years) with suboptimal plasma vitamin C status (<50 μmol/L) were supplemented for four weeks with two SunGold kiwifruit/day. Plasma vitamin C status was monitored weekly and neutrophil vitamin C levels were assessed at baseline and post-intervention. Neutrophil function assays were carried out on cells isolated at baseline and post-intervention. Plasma vitamin C levels increased to >70 μmol/L (p < 0.001) within one week of supplementation and there was a significant increase in neutrophil vitamin C status following four weeks’ intervention (p = 0.016). We observed a significant 20% increase in neutrophil chemotaxis post-intervention (p = 0.041) and also a comparable increase in oxidant generation (p = 0.031). Supplementation did not affect neutrophil extracellular trap formation or spontaneous apoptosis. Our data indicate that supplementation with vitamin C-rich kiwifruit is associated with improvement of important neutrophil functions, which would be expected to translate into enhanced immunity.     

News briefs

Control of both type I and type II diabetes involves the appropriate balance of exercise, diet, and medication. Regular, long-term exercise has many benefits for people with diabetes. Physicians can educate patients about ways to regulate and monitor blood glucose before, during, and after a workout or competition. Physicians also need to discuss the warning signs of hypoglycemia, hyperglycemia, ketoacidosis, and dehydration and how to prevent the conditions. In addition, patients who have type I diabetes need to know the effects of exercise on insulin requirements. Nutrition needs will vary for each patient, type of activity, and other factors, but food intake can be readily adjusted in conjunction with blood glucose monitoring.     

Pragmatic Trials in Long-Term Care: Implementation and Dissemination Challenges and Opportunities

Randomized controlled trials are considered the most rigorous research design in efficacy and effectiveness research; however, such trials present numerous challenges that limit their applicability in real-world settings. As a consequence, pragmatic trials are increasingly viewed as a research design that overcomes some of these barriers with the potential to produce findings that are more reproducible. Although pragmatic methodology in long-term care is receiving increasing attention as an approach to improve successful dissemination and implementation, pragmatic trials present complexities of their own. To address these complexities and related issues, experts with experience conducting pragmatic trials, developing nursing home policy, participating in advocacy efforts, and providing clinical care in long-term care settings participated in a virtual consensus conference funded by the National Institute on Aging in Spring 2021. Participants identified 4 cross-cutting principles key to dissemination and implementation of pragmatic trial interventions: (1) stakeholder engagement, (2) diversity and inclusion, (3) organizational strain and readiness, and (4) learn from adaptations. Participants emphasized that implementation processes must be grounded in the perspectives of the people who will ultimately be responsible for implementing the intervention once it is proven to be effective. In addition, messaging must speak to long-term care staff and all others who have a stake in its outcomes. Although our understanding of dissemination and implementation strategies remains underdeveloped, this article is designed to guide long-term care researchers and community providers who are increasingly aware of the need for pragmatism in disseminating and implementing evidence-based care interventions.     

To stand back or step in? Exploring the responses of employees who observe workplace bullying

Bullying remains a pervasive problem in healthcare, and evidence suggests systems in place are not utilised due to perceptions of ineffectiveness and inequity. This study examines bystander responses to bullying and factors that influence decisions to intervene. We explore relationships between bystanders’ perceptions of psychological safety across three levels (organisation, supervisor and colleague) and reactions to witnessing bullying. We suggest psychological safety would be positively associated with the decision to intervene. Findings indicate the most pervasive reaction to witnessing incidents of bullying is to discuss with colleagues, a low‐involvement reaction. We find perceptions of supervisory and organisational safety/support are positively related to high‐involvement decisions such as formal reporting of the incidents, highlighting the importance of support from those in power. However, perceptions of collegial support may lead to low‐involvement responses, which risk reinforcing and underpinning dysfunctional organisational dynamics by providing informal social and emotional responses that may substitute more formal organisational responses to this persistent problem. This study highlights the importance of support from individuals in power if bystanders are to feel comfortable making high‐involvement interventions.