Breastfeeding Aversion Response (BAR): A Descriptive Study

Introduction

For many women, breastfeeding their infant is an enjoyable experience. Some, however, have reported negative sensations such as an overwhelming need to unlatch while breastfeeding. This phenomenon is known as breastfeeding aversion response (BAR). The incidence of BAR is unknown and literature on this experience is limited. This study therefore aimed to expand the understanding of BAR using an online survey targeting those who have experienced feelings of aversion while breastfeeding.

Methods

An online survey was distributed within Australia using purposive sampling to those who self-identified as experiencing BAR. This survey contained 5 sections: (1) demographics and health-related characteristics, (2) breastfeeding difficulties and onset of BAR, (3) the experience of BAR, (4) birth and breastfeeding experience, and (5) coping with BAR and support. Questions were included to test the generalizability of previous qualitative findings on BAR.

Results

Participants (N = 210) predominantly were aged between 25 and 35 years (69.2%), were in a relationship (96.2%), and had one child (80%). BAR was more commonly experienced when feeding the first-born child (44.8%), breastfeeding while pregnant (31%), or tandem feeding (10%). The feelings of aversion were experienced by most respondents throughout the feed while the child was latched (76.7%). More than half (52.4%) of participants reported that BAR had caused them to end breastfeeding sessions before their child was ready to stop feeding. Almost half of the participants (48.6%) reported receiving no support from a health care provider for BAR.

Discussion

This study contributes new information about the experience of BAR, including when it commonly happens and who may be at greater risk. More support is needed for women who want to breastfeed while experiencing BAR. New public health policies which promote breastfeeding are needed to help women achieve satisfying breastfeeding experiences and meet their own breastfeeding goals.     

Altered anticipatory brain responses in eating disorders: A neuroimaging meta-analysis

Objective

Functional neuroimaging studies have found differential neural activation patterns during anticipation-related paradigms in participants with eating disorders (EDs) compared to controls. However, publications reported conflicting results on the directionality and location of the abnormal activations. There is an urgent need to integrate our existing knowledge of anticipation, both rewarding and aversive, to elucidate these differences.

Method

We conducted an activation likelihood estimation (ALE) meta-analysis to quantitatively review functional neuroimaging studies that evaluated differences between brain correlates of anticipation in participants with and without disordered eating. PubMed, Web of Sciences, PsycINFO, Medline and EMBASE were searched for studies published up to November 2022. Exploratory sub-analyses to check for differences between reward and non-reward anticipation among all anticipation paradigms.

Results

Twenty-one references met the inclusion criteria for meta-analysis. The meta-analysis across anticipation all tasks identified a significant hyperactivation cluster in the right putamen in participants with disordered eating (n = 17 experiments) and a significant hypoactivation cluster in the left inferior parietal lobule (n = 13 experiments), in participants with disordered eating compared to controls.

Conclusions

These findings and sub-analyses of reward- and non-reward-related cues suggest potential pathophysiological mechanisms underlying anticipatory responses to rewarding and aversive cues in ED.     

骨癌痛诱发大鼠焦虑样行为和前扣带回脑区NR2B的上调表达

目的研究骨癌痛(bone cancer pain,BCP)对大鼠情绪的影响和前扣带回皮质(anterior cingulate cortex,ACC)处N-甲基-D-天门冬氨酸(N-Methyl-D-Aspartate,NMDA)受体NR2B亚基表达量的关系。方法选择健康3月龄雄性Wistar大鼠150只,体重200~250g,随机分为假手术组(S组)、BCP模型组(BCP组)和模型腹腔注射NR2B拮抗剂RO25-6981组(RO组),每组50只。BCP模型采用右侧胫骨注射Walker 256乳腺癌细胞的方法制备,S组注射等量d-hanks液。RO组于造模后经腹腔注射RO25-6981(5mg·kg-1·d-1),S组和BCP组注射等量生理盐水。三组大鼠分别于造模前1d和造模后3、7、10和14d测右侧后足底机械缩足阈值(MWT)和热缩足反射潜伏期(TWL)。每次痛阈检测后,通过高架十字迷宫观测BCP对大鼠情绪的影响,计算开放臂进入次数(OE)百分比、开放臂停留时间(OT)百分比,造模后第14天待高架十字迷宫实验完成后,取大鼠ACC组织采用RT-PCR、Western blot和免疫荧光方法检测NR2B的mRNA和蛋白表达水平。结果 S组和RO组各指标差异均无统计学意义。术后7、10、14dBCP组MWT明显低于、TWL明显短于术前1d及S组和RO组(P0.05);BCP组OE和OT明显低于术前1d及S组和RO组(P0.05),ACC脑区NR2BmRNA相对吸光度、NR2B蛋白表达、NR2B荧光密度明显高于S组和RO组(P0.05)。结论BCP可致大鼠痛厌恶焦虑样行为,其机制可能与ACC脑区的NR2B表达上调有关。     

Eliciting Trade-Offs Between Equity and Efficiency: A Methodological Scoping Review

ObjectivesTo identify differences in the approaches and results of studies that elicit equity-efficiency trade-offs that can inform equity-informative cost-effectiveness analysis for healthcare resource allocation.MethodsWe searched Ovid (Medline), EconLit, and Scopus prior to June 25, 2021. Inclusion criteria were: (1) peer-reviewed or (2) gray literature; (3) published in English; (4) survey-based; (5) parameterized a social welfare function to quantify inequality aversion or (6) elicited a trade-off in equity and efficiency characteristics of health interventions. Exclusion criteria were: (1) studies that did not conduct a trade-off or (2) theoretical studies. We abstracted details on study methods, results, and limitations. Studies were grouped by following approach: (1) social welfare function or (2) preference ranking and distributional weighting. We described findings separately for each approach category.ResultsSeventy-seven papers were included, 28 parameterized social welfare functions and 49 were classified as preference ranking and distributional weighting. Study methods were heterogeneous. Studies were conducted across 29 countries. Sample sizes and composition, survey methods and question framing varied. Preferences for equity were mixed. Across both approach categories: 39 studies were classified as clear evidence of inequality aversion; 33 found mixed evidence; and 4 had no evidence of aversion. Evidence of between and within-study heterogeneity was found. Preferences for equity may differ by gender, profession, political ideology, income, and education.ConclusionsSubstantial variability in study methods limit the direct comparability of findings and their use in equity-informed cost-effectiveness analysis. Future researches using representative samples that explore within and between country heterogeneity is needed.     

How Uncertainty Matters Under Risk Neutrality

It is typical in cost-effectiveness analysis to invoke a normative decision-making framework that assumes, as a starting point, that “a quality-adjusted life-year (QALY) is a QALY is a QALY.” The implication of this assumption is that the decision maker is risk neutral and that expected values could be considered sufficiently informative for a given “approve or reject” decision. Nevertheless, it seems intuitive that less uncertainty should be desirable and this has led some to incorporate “real” risk aversion (RA) into cost-effectiveness analysis.We illustrate in this article that RA is not always necessary to justify choosing more over less certain options. We show that for a risk neutral decision maker, greater uncertainty can make the approval of technology less likely in the presence of (1) model nonlinearities, (2) nonlinear opportunity costs, and (3) irreversible costs. We call these cases of “apparent” RA.Incorporating explicit risk preferences into decision making can be challenging; nevertheless, as we show here, it is not necessary to justify caring about uncertainty in approval decisions.     

Alcohol,place conditioning,and male rats: A systematic review of outcome prediction

Although Place Conditioning (PC) has been used to study the motivational effects of alcohol for almost 50 years, variables and situations in which alcohol induces PC in rats are still unclear, especially for short PC protocols (up to 10 conditioning trials). The aim of this systematic review was to predict primary outcomes (namely, conditioning failure, conditioned place aversion (CPA), and conditioned place preference (CPP)) of alcohol-induced PC with male outbred rats. We sought relevant records in PUBMED and two other sources. Two reviewers independently assessed records for eligible articles (those meeting all inclusion criteria), selected alcohol-induced PC experiments (those meeting no exclusion criteria) from eligible articles, extracted data, and assessed the quality of included studies. We then conducted a predictive analysis of outcomes by examining procedure-outcome relations according to variables known to affect associative learning, alcohol interventions in rats, and PC interventions themselves. We selected 192 experiments (133 short protocols, 27 long protocols, and 32 protocols with alcohol pre-exposure) from 62 articles to compose the review. Rates of conditioning failure are mainly predicted by interactions of alcohol dose and the number of habituation sessions and conditioning trials. Different conditions (housing systems) and characteristics (age and weight) of animals predict CPA and CPP: higher rates of CPA are predicted by single-housed, older, and heavier animals, while higher rates of CPP are predicted by group-housed, younger, and lighter animals. We recommend settings for CPP induction in short protocols, discuss the broad theoretical and translational consequences of the predictive analysis for the use of PC in alcohol research, and specify variables needing more careful investigation. This review could improve our understanding of the results of alcohol-induced PC with rats, refine our understanding of the motivational function of alcohol and alcohol-seeking behavior triggered by environmental contexts, and open new avenues of research on their neurobiological basis.