Sustaining attention in affective contexts during adolescence: age-related differences and association with elevated symptoms of depression and anxiety.

Sustained attention, a key cognitive skill that improves during childhood and adolescence, tends to be worse in some emotional and behavioural disorders. Sustained attention is typically studied in non-affective task contexts; here, we used a novel task to index performance in affective versus neutral contexts across adolescence (N = 465; ages 11-18). We asked whether: (i) performance would be worse in negative versus neutral task contexts; (ii) performance would improve with age; (iii) affective interference would be greater in younger adolescents; (iv) adolescents at risk for depression and higher in anxiety would show overall worse performance; and (v) would show differential performance in negative contexts. Results indicated that participants performed more poorly in negative contexts and showed age-related performance improvements. Those at risk of depression performed more poorly than those at lower risk. However, there was no difference between groups as a result of affective context. For anxiety there was no difference in performance as a function of severity. However, those with higher anxiety showed less variance in their reaction times to negative stimuli than those with lower anxiety. One interpretation is that moderate levels of emotional arousal associated with anxiety make individuals less susceptible to the distracting effects of negative stimuli.

Susceptibility to prosocial and antisocial influence in adolescence.

INTRODUCTION: Adolescents are particularly susceptible to social influence and previous studies have shown that this susceptibility decreases with age. The current study used a cross-sectional experimental paradigm to investigate the effect of age and puberty on susceptibility to both prosocial and antisocial influence. METHODS: Participants (N = 520) aged 11-18 from London and Cambridge (United Kingdom) rated how likely they would be to engage in a prosocial (e.g. "help a classmate with their work") or antisocial (e.g. "make fun of a classmate") act. They were then shown the average rating (in fact fictitious) that other adolescents had given to the same question, and were then asked to rate the same behaviour again. RESULTS: Both prosocial and antisocial influence decreased linearly with age, with younger adolescents being more socially influenced when other adolescents' ratings were more prosocial and less antisocial than their own initial rating. Both antisocial and prosocial influence significantly decreased across puberty for boys but not girls (independent of age). CONCLUSIONS: These findings suggest that social influence declines with increasing maturity across adolescence. However, the exact relationship between social influence and maturity is dependent on the nature of the social influence and gender. Understanding when adolescents are most susceptible to different types of social influence, and how this might influence their social behaviour, has important implications for understanding adolescent social development.

Socioeconomic inequalities and the equity impact of population-level interventions for adolescent health: an overview of systematic reviews.

OBJECTIVES: Despite robust evidence on health inequalities in adulthood, less attention has been paid to inequalities in adolescence. The aim of this overview was to examine systematic review (SR) evidence on the equity impact of population-level interventions intended to improve health, happiness and wellbeing for adolescents. STUDY DESIGN: An overview (review of systematic reviews). METHODS: Eleven electronic databases were systematically searched to identify SRs of population-level interventions for adolescent health. A secondary data analysis of socioeconomic inequality was conducted to identify whether SRs reported on primary studies in terms of disadvantage, by measures of socioeconomic status (SES) and by differential effects. RESULTS: 35,310 review titles were screened; 566 full texts were retrieved and 140 SRs met the predefined selection criteria. Differential intervention effects were considered in 42/140 (30%) SRs, 18/140 (13%) reported primary studies using an SES measure and 16/140 (11%) explicitly reported differential effects. 15/140 SRs (11%) explicitly focused on socioeconomic inequalities; of these 4/15 reported differential intervention effects in more detail, 7/15 concluded there was insufficient primary evidence to identify the impact of interventions on socioeconomic inequalities and 4/15 planned to examine differential effects by SES, but this was not reported further. CONCLUSIONS: Our overview identifies that there is limited SR evidence on the equity impact of population-level interventions for adolescent health. Strengthening the evidence on whether interventions narrow or widen inequalities for adolescents must be a priority for public health research.

Author Correction: Mice lacking NF-κB1 exhibit marked DNA damage responses and more severe gastric pathology in response to intraperitoneal tamoxifen administration.

Following the publication of this article [1], it was noted that the author list was incomplete and was missing the following author.

Is the caudal auricular axial pattern flap robust? A multi-centre cohort study of 16 dogs and 12 cats (2005 to 2016).

OBJECTIVE: To determine the frequency and type of healing complications arising after the use of the caudal auricular axial pattern flap to close defects on the head in dogs and cats. MATERIAL AND METHODS: Multi-centre retrospective cohort study. Centres were recruited by the Association for Veterinary Soft Tissue Surgery Research Cooperative. Medical records of 11 centres were reviewed, and data from all dogs and cats treated with a caudal auricular axial pattern flap were retrieved. The following data were recorded: signalment, reason for reconstruction, flap dimensions, anatomic landmarks used, histological diagnosis, flap healing and whether revision surgery was required. RESULTS: Twenty-eight cases were included: 16 dogs and 12 cats. Flap length: width ratio was approximately 3:1 and flap length extended to the scapular spine in most cases. Optimal wound healing occurred in five of 16 (31%) dogs and six of 12 (50%) cats. Wound dehiscence without flap necrosis occurred in one of 16 (6%) dogs and one of 12 (8%) cats. Wound dehiscence with flap necrosis occurred in 10 of 16 (63%) dogs and five of 12 (42%) cats. Revision surgery was performed in eight of 16 (50%) dogs and three of 12 (25%) cats. CLINICAL SIGNIFICANCE: The caudal auricular axial pattern flap can provide full thickness skin coverage for large defects on the head in dogs and cats. Partial flap necrosis is a common complication, and revision surgery may be required in order to achieve final wound closure.

Children and young people's conceptualizations of depression: a systematic review and narrative meta-synthesis.

BACKGROUND: There is an increasing research interest in conceptualizations of mental illness, examined in association with help-seeking, stigma and treatment preferences. A recent focus on young people's concepts has been identified, with depression being one of the most examined conditions. METHODS: The purpose of this systematic review is to synthesize evidence on children and adolescents' conceptualizations of depression, adopting the model of illness representations. The review further aims to examine developmental trends, gender differences and the role of experience. A systematic review and narrative meta-synthesis were conducted, reviewing 36 studies identified through a systematic search of six databases in March 2016. RESULTS: Thirty-six quantitative and qualitative studies were included. Half of the young people are able to recognize depression, and recognition increases when symptoms are more severe (e.g. suicidality). Young people are able to name a variety of causes for depression. Mental health professionals are considered the appropriate source of help by half of the young people, followed by family and peers. However, stigma constitutes a major barrier to help-seeking. There are developmental trends and gender differences in young people's conceptualization of depression, while experience with depression is associated with a broader conceptualization. CONCLUSIONS: Young people's concepts of depression resemble aspects of adult conceptualizations, however are sometimes incomplete. Further research on younger children and clinical populations is needed. Research on young people's conceptualizations informs both clinical practice and mental health literacy interventions.

What defines mindfulness-based programs? The warp and the weft.

There has been an explosion of interest in mindfulness-based programs (MBPs) such as Mindfulness-Based Stress Reduction (MBSR) and Mindfulness-Based Cognitive Therapy. This is demonstrated in increased research, implementation of MBPs in healthcare, educational, criminal justice and workplace settings, and in mainstream interest. For the sustainable development of the field there is a need to articulate a definition of what an MBP is and what it is not. This paper provides a framework to define the essential characteristics of the family of MBPs originating from the parent program MBSR, and the processes which inform adaptations of MBPs for different populations or contexts. The framework addresses the essential characteristics of the program and of teacher. MBPs: are informed by theories and practices that draw from a confluence of contemplative traditions, science, and the major disciplines of medicine, psychology and education; underpinned by a model of human experience which addresses the causes of human distress and the pathways to relieving it; develop a new relationship with experience characterized by present moment focus, decentering and an approach orientation; catalyze the development of qualities such as joy, compassion, wisdom, equanimity and greater attentional, emotional and behavioral self-regulation, and engage participants in a sustained intensive training in mindfulness meditation practice, in an experiential inquiry-based learning process and in exercises to develop understanding. The paper's aim is to support clarity, which will in turn support the systematic development of MBP research, and the integrity of the field during the process of implementation in the mainstream.

EEG Topographic Mapping of Visual and Kinesthetic Imagery in Swimmers.

This study investigated differences in QEEG measures between kinesthetic and visual imagery of a 100-m swim in 36 elite competitive swimmers. Background information and post-trial checks controlled for the modality of imagery, swimming skill level, preferred imagery style, intensity of image and task equality. Measures of EEG relative magnitude in theta, low (7-9 Hz) and high alpha (8-10 Hz), and low and high beta were taken from 19 scalp sites during baseline, visual, and kinesthetic imagery. QEEG magnitudes in the low alpha band during the visual and kinesthetic conditions were attenuated from baseline in low band alpha but no changes were seen in any other bands. Swimmers produced more low alpha EEG magnitude during visual versus kinesthetic imagery. This was interpreted as the swimmers having a greater efficiency at producing visual imagery. Participants who reported a strong intensity versus a weaker feeling of the image (kinesthetic) had less low alpha magnitude, i.e., there was use of more cortical resources, but not for the visual condition. These data suggest that low band (7-9 Hz) alpha distinguishes imagery modalities from baseline, visual imagery requires less cortical resources than kinesthetic imagery, and that intense feelings of swimming requires more brain activity than less intense feelings.

bak deletion stimulates gastric epithelial proliferation and enhances Helicobacter felis-induced gastric atrophy and dysplasia in mice.

Helicobacter infection causes a chronic superficial gastritis that in some cases progresses via atrophic gastritis to adenocarcinoma. Proapoptotic bak has been shown to regulate radiation-induced apoptosis in the stomach and colon and also susceptibility to colorectal carcinogenesis in vivo. Therefore we investigated the gastric mucosal pathology following H. felis infection in bak-null mice at 6 or 48 wk postinfection. Primary gastric gland culture from bak-null mice was also used to assess the effects of bak deletion on IFN-γ-, TNF-α-, or IL-1ß-induced apoptosis. bak-null gastric corpus glands were longer, had increased epithelial Ki-67 expression, and contained fewer parietal and enteroendocrine cells compared with the wild type (wt). In wt mice, bak was expressed at the luminal surface of gastric corpus glands, and this increased 2 wk post-H. felis infection. Apoptotic cell numbers were decreased in bak-null corpus 6 and 48 wk following infection and in primary gland cultures following cytokine administration. Increased gastric epithelial Ki-67 labeling index was observed in C57BL/6 mice after H. felis infection, whereas no such increase was detected in bak-null mice. More severe gastric atrophy was observed in bak-null compared with C57BL/6 mice 6 and 48 wk postinfection, and 76% of bak-null compared with 25% of C57BL/6 mice showed evidence of gastric dysplasia following long-term infection. Collectively, bak therefore regulates gastric epithelial cell apoptosis, proliferation, differentiation, mucosal thickness, and susceptibility to gastric atrophy and dysplasia following H. felis infection.

Epithelial cell shedding and barrier function: a matter of life and death at the small intestinal villus tip.

The intestinal epithelium is a critical component of the gut barrier. Composed of a single layer of intestinal epithelial cells (IECs) held together by tight junctions, this delicate structure prevents the transfer of harmful microorganisms, antigens, and toxins from the gut lumen into the circulation. The equilibrium between the rate of apoptosis and shedding of senescent epithelial cells at the villus tip, and the generation of new cells in the crypt, is key to maintaining tissue homeostasis. However, in both localized and systemic inflammation, this balance may be disturbed as a result of pathological IEC shedding. Shedding of IECs from the epithelial monolayer may cause transient gaps or microerosions in the epithelial barrier, resulting in increased intestinal permeability. Although pathological IEC shedding has been observed in mouse models of inflammation and human intestinal conditions such as inflammatory bowel disease, understanding of the underlying mechanisms remains limited. This process may also be an important contributor to systemic and intestinal inflammatory diseases and gut barrier dysfunction in domestic animal species. This review aims to summarize current knowledge about intestinal epithelial cell shedding, its significance in gut barrier dysfunction and host-microbial interactions, and where research in this field is directed.

Association of aberrant neural synchrony and altered GAD67 expression following exposure to maternal immune activation, a risk factor for schizophrenia.

A failure of integrative processes within the brain, mediated via altered GABAergic inhibition, may underlie several features of schizophrenia. The present study examined, therefore, whether maternal immune activation (MIA), a risk factor for schizophrenia, altered inhibitory markers in the hippocampus and medial prefrontal cortex (mPFC), while also altering electroencephalogram (EEG) coherence between these regions. Pregnant rats were treated with saline or polyinosinic:polycytidylic acid mid-gestation. EEG depth recordings were made from the dorsal and ventral hippocampus and mPFC of male adult offspring. Glutamic decarboxylase (GAD67) levels were separately assayed in these regions using western blot. GAD67 expression was also assessed within parvalbumin-positive cells in the dorsal and ventral hippocampus using immunofluorescence alongside stereological analysis of parvalbumin-positive cell numbers. EEG coherence was reduced between the dorsal hippocampus and mPFC, but not the ventral hippocampus and mPFC, in MIA animals. Western blot and immunofluorescence analyses revealed that GAD67 expression within parvalbumin-positive cells was also reduced in the dorsal hippocampus relative to ventral hippocampus in MIA animals when compared with controls. This reduction was observed in the absence of parvalbumin-positive neuronal loss. Overall, MIA produced a selective reduction in EEG coherence between the dorsal hippocampus and mPFC that was paralleled by a similarly specific reduction in GAD67 within parvalbumin-positive cells of the dorsal hippocampus. These results suggest a link between altered inhibitory mechanisms and synchrony and, therefore point to potential mechanisms via which a disruption in neurodevelopmental processes might lead to pathophysiology associated with schizophrenia.

Dark-field microscopy in the assessment of large colon microperfusion and mucosal injury in naturally occurring surgical disease of the equine large colon.

REASON FOR PERFORMING STUDY: Intraoperative assessment of colonic viability can be challenging and largely subjective. Objective methods are often impractical. Viability is related to re-establishment of colonic perfusion; particularly microvascular perfusion. This study evaluated the utility of dark-field microscopy (DFM) of the colonic serosa as an objective method of assessing microperfusion. OBJECTIVES: To measure microvascular perfusion indices (MPI) of the pelvic flexure serosa in horses with surgical colonic lesions and correlate these with macroperfusion indices (MaPI) and histomorphometry. STUDY DESIGN: Prospective, clinical, case-control study. METHODS: Control horses and horses with colonic volvulus (LCV), displacement, and/or simple obstruction undergoing surgery had DFM video loops performed on the pelvic flexure. Total vessel density, perfused vessel density, proportion of perfusion vessels and microvascular flow index were calculated from video analysis. Macroperfusion indices (arterial blood pressure and heart rate) were recorded. Histomorphometry was used to determine a mucosal injury score. Differences between lesions for MPI, MaPI and histomorphometry were compared using ANOVA or Kruskal-Wallis statistic. Spearman correlations between MPI with MaPI were performed. Linear regression was used to assess the relationship between MPI and histomorphometry. P<0.05 was significant. RESULTS: Horses with LCV had lower perfused vessel density, proportion of microvascular perfusion vessels and flow index than horses with nonstrangulating obstructions and control horses. Macroperfusion indices were not correlated with MPI but MPI were correlated with histomorphometry. CONCLUSIONS: Dark-field microscopy is achievable in the operating room and can quantify MPI from the colonic serosa in different colonic lesions. Macroperfusion indices were not related with colonic MPI. Microvascular perfusion indices can predict the severity of histopathological change at the pelvic flexure. Derangements of MPI may be more useful indicators of colonic pathology and viability and offer a more objective assessment of intestinal injury than subjective methods. Further study is needed to determine the utility of DFM in predicting survival in horses with LCV.

Signaling mediated by the NF-κB sub-units NF-κB1, NF-κB2 and c-Rel differentially regulate Helicobacter felis-induced gastric carcinogenesis in C57BL/6 mice.

The classical nuclear factor-kappaB (NF-κB) signaling pathway has been shown to be important in a number of models of inflammation-associated cancer. In a mouse model of Helicobacter-induced gastric cancer, impairment of classical NF-κB signaling in the gastric epithelium led to the development of increased preneoplastic pathology, however the role of specific NF-κB proteins in Helicobacter-associated gastric cancer development remains poorly understood. To investigate this C57BL/6, Nfkb1(-/-), Nfkb2(-/-) and c-Rel(-/-) mice were infected with Helicobacter felis for 6 weeks or 12 months. Bacterial colonization, gastric atrophy and preneoplastic changes were assessed histologically and cytokine expression was assessed by qPCR. Nfkb1(-/-) mice developed spontaneous gastric atrophy when maintained for 12 months in conventional animal house conditions. They also developed more pronounced gastric atrophy after short-term H. felis colonization with a similar extent of preneoplasia to wild-type (WT) mice after 12 months. c-Rel(-/-) mice developed a similar degree of gastric atrophy to WT mice; 3 of 6 of these animals also developed lymphoproliferative lesions after 12 months of infection. Nfkb2(-/-) mice developed minimal gastric epithelial pathology even 12 months after H. felis infection. These findings demonstrate that NF-κB1- and NF-κB2-mediated signaling pathways differentially regulate the epithelial consequences of H. felis infection in the stomach, while c-Rel-mediated signaling also appears to modulate the risk of lymphomagenesis in gastric mucosa-associated lymphoid tissue.

Ultrasonographic findings of the pancreas in cats with elevated serum pancreatic lipase immunoreactivity.

BACKGROUND: Pancreatitis is a common disease in cats that is difficult to diagnose. HYPOTHESIS/OBJECTIVES: To determine the sensitivity and specificity of ultrasonographic changes of the pancreas with serum feline pancreatic lipase immunoreactivity (fPLI) as the standard for diagnosis of pancreatitis. ANIMALS: 35 cats with clinical signs consistent with pancreatitis with an abdominal ultrasound examination and serum fPLI concentration measured within 3 days of the ultrasound. METHODS: Retrospective study: Pancreatic thickness, pancreatic margination, pancreatic echogenicity, and peripancreatic fat echogenicity were evaluated. Sensitivity and specificity were calculated with an elevated serum fPLI concentration indicative of pancreatitis as the standard for diagnosis. RESULTS: Serum fPLI was elevated and diagnostic for pancreatitis in 19 of 35 cats. The single ultrasound characteristic with the highest sensitivity was hyperechoic peripancreatic fat at 68% (95% confidence interval = 44-87%), indicating a moderate probability that cats with pancreatitis will have this abnormality on ultrasonographic examination. Specificity was >90% for each of increased pancreatic thickness, abnormal pancreatic margin, and hyperechoic peripancreatic fat. The sensitivity and specificity of ultrasound were 84% (95% confidence interval = 60-97%) and 75% (95% confidence interval = 48-93%), respectively, in cats with elevated serum fPLI indicative of pancreatitis. CONCLUSIONS AND CLINICAL IMPORTANCE: The presence of a thick left limb of the pancreas, severely irregular pancreatic margins, and hyperechoic peripancreatic fat in cats with appropriate clinical signs and elevated serum fPLI are highly supportive of pancreatitis.

Rapid visual stimulation increases extrasynaptic glutamate receptor expression but not visual-evoked potentials in the adult rat primary visual cortex.

The model most used to study synaptic plasticity, long-term potentiation (LTP), typically employs electrical stimulation of afferent fibers to induce changes in synaptic strength. It would be beneficial for understanding the behavioral relevance of LTP if a model could be developed that used more naturalistic stimuli. Recent evidence suggests that the adult visual cortex, previously thought to have lost most of its plasticity once past the critical period, is in fact capable of LTP-like changes in synaptic strength in response to sensory manipulations alone. In a preliminary study, we used a photic tetanus (PT; flashing checkerboard stimulus) to induce an enhancement of the visual-evoked potential (VEP) in the primary visual cortex of anesthetised adult rats. In the present study, we sought to compare the mechanisms of this novel sensory LTP with those of traditional electrical LTP. Unexpectedly, we found that sensory LTP was not induced as reliably as we had observed previously, as manipulations of several parameters failed to lead to significant potentiation of the VEP. However, we did observe a significant increase in visual cortex glutamate receptor expression on the surface of isolated synapses following the PT. Both AMPA receptor expression and N-methyl-d-aspartate (NMDA) receptor subunit expression were increased, specifically in extrasynaptic regions of the membrane, in PT animals. These results provide biochemical confirmation of the lack of change in the VEP in response to PT, but suggest that PT may prime synapses for strengthening upon appropriate subsequent activation, through the trafficking of glutamate receptors to the cell surface.

Aging affects L-arginine and its metabolites in memory-associated brain structures at the tissue and synaptoneurosome levels.

L-arginine, one of the most metabolically versatile amino acids, can be metabolized to form a number of bioactive molecules. The present study systematically investigated age-related changes in L-arginine and its metabolites in the hippocampus, parahippocampal region, and prefrontal cortex at the tissue (crude homogenates) and synaptoneurosome (a subcellular preparation enriched for synaptic material) levels. As aging leads to reduced water content in the brain, age-related changes in neurochemical levels in tissue homogenates normalized by wet tissue weight and protein level were compared. There were significant differences in L-arginine, L-citrulline, L-ornithine, agmatine, putrescine, spermidine, spermine, and glutamate, but not GABA, in the CA1, CA2/3, and dentate gyrus sub-regions of the hippocampus and the prefrontal, entorhinal, perirhinal, and postrhinal cortices in 24 (aged) and 4 (young) months old rats in a region-specific manner. The overall pattern of age-related changes in amino acids (L-arginine, L-citrulline, L-ornithine, glutamate, and GABA) was largely similar between homogenates and synaptoneurosomes, whereas the pattern for the amines (agmatine, putrescine, spermidine, and spermine) was quite different. Furthermore, the pattern of age-related changes in neurochemical levels in tissue homogenates normalized by wet tissue weight and protein level was very similar for all 9 neurochemicals measured. These findings suggest that there are differential effects of aging on L-arginine metabolism at the tissue and synaptoneurosome levels and that the way of data normalization (tissue weight vs. protein level) has no or very minor effects on 9 neurochemicals measured.

A low noise preamplifier with optoelectronic overload protection for radioactivity measurement.

Pulses from detectors used for radioactivity measurement can vary in size by several orders of magnitude. Large pulses will lead to saturation at the preamplifier output and extension of the pulse length. As a consequence, the dead time of the system increases and pulses may be lost. Electronic design techniques employed to protect against overloading tend to increase the amplifier noise level. However, an optoelectronic method of overload protection has been devised which has only a negligible effect on noise. An infrared light emitting diode interfaced to the output of the preamplifier is linked by fibre optic cable to an ultra-low leakage photodiode at the input. The conduction of the photodiode increases with the amplitude of the preamplifier output signal. Excess current is thereby prevented from entering the preamplifier and causing saturation. The preamplifier has been tested on 4π beta-gamma and gas counting systems and found to give good protection against overloading.