Steering opinion dynamics through control of social networks.

In this paper, we propose a novel control approach for opinion dynamics on evolving networks. The controls modify the strength of connections in the network, rather than influencing opinions directly, with the overall goal of steering the population toward a target opinion. This requires that the social network remains sufficiently connected, the population does not break into separate opinion clusters, and that the target opinion remains accessible. We present several approaches to address these challenges, considering questions of controllability, instantaneous control, and optimal control. Each of these approaches provides a different view on the complex relationship between opinion and network dynamics and raises interesting questions for future research.

Habitual protein intake, protein distribution patterns and dietary sources in Irish adults with stratification by sex and age.

BACKGROUND: Given the importance of habitual dietary protein intake, distribution patterns and dietary sources in the aetiology of age-related declines of muscle mass and function, the present study examined these factors as a function of sex and age in Irish adults aged 18-90 years comprising The National Adult Nutrition Survey (NANS). METHODS: In total, 1051 (males, n = 523; females, n = 528) undertook a 4-day semi-weighed food diary. Total, body mass relative intake and percentage contribution to total energy intake of dietary protein were determined in addition to protein distribution scores (PDS), as well as the contribution of food groups, animal- and plant-based foods to total protein intake. RESULTS: Total and relative protein intake [mean (SD)] were highest in those aged 18-35 years [96 (3) g day-1 , 1.32 (0.40) g kg-1  day-1 ], with lower protein intakes with increasing age (i.e. in adults aged ≥65 years [82 (22) g, 1.15 (0.34) g kg-1  day-1 , P < 0.001 for both]. Differences in protein intake between age groups were more pronounced in males compared to females. Protein distribution followed a skewed pattern for all age groups [breakfast, 15 (10) g; lunch, 30 (15) g; dinner, 44 (17) g]. Animal-based foods were the dominant protein source within the diet [63% (11%) versus 37% (11%) plant protein, P < 0.001]. CONCLUSIONS: Protein intake and the number of meals reaching the purported threshold for maximising post-prandial anabolism were highest in young adults, and lower with increasing age. For main meals, breakfast provided the lowest quantity of protein across all age categories and may represent an opportunity for improving protein distribution, whereas, in older adults, increasing the number of meals reaching the anabolic threshold regardless of distribution pattern may be more appropriate.

Common and distinct patterns of grey-matter volume alteration in major depression and bipolar disorder: evidence from voxel-based meta-analysis.

Finding robust brain substrates of mood disorders is an important target for research. The degree to which major depression (MDD) and bipolar disorder (BD) are associated with common and/or distinct patterns of volumetric changes is nevertheless unclear. Furthermore, the extant literature is heterogeneous with respect to the nature of these changes. We report a meta-analysis of voxel-based morphometry (VBM) studies in MDD and BD. We identified studies published up to January 2015 that compared grey matter in MDD (50 data sets including 4101 individuals) and BD (36 data sets including 2407 individuals) using whole-brain VBM. We used statistical maps from the studies included where available and reported peak coordinates otherwise. Group comparisons and conjunction analyses identified regions in which the disorders showed common and distinct patterns of volumetric alteration. Both disorders were associated with lower grey-matter volume relative to healthy individuals in a number of areas. Conjunction analysis showed smaller volumes in both disorders in clusters in the dorsomedial and ventromedial prefrontal cortex, including the anterior cingulate cortex and bilateral insula. Group comparisons indicated that findings of smaller grey-matter volumes relative to controls in the right dorsolateral prefrontal cortex and left hippocampus, along with cerebellar, temporal and parietal regions were more substantial in major depression. These results suggest that MDD and BD are characterised by both common and distinct patterns of grey-matter volume changes. This combination of differences and similarities has the potential to inform the development of diagnostic biomarkers for these conditions.

Nutrient intakes and compliance with nutrient recommendations in children aged 1-4 years in Ireland.

BACKGROUND: The early childhood years represent a period of rapid growth and development characterised by unique requirements for energy and individual nutrients. METHODS: The present study uses data from the National Pre-School Nutrition Survey, a nationally representative sample of Irish children (1-4 years) (n = 500), aiming to estimate energy and nutrient intakes across age and compliance with recommendations (UK and European). A 4-day weighed food-record was used to collect dietary data and statistical modelling (National Cancer Institute method) was applied to estimate usual nutrient intakes. RESULTS: Intakes of carbohydrate [48-50% energy (E)], protein (15-16%E), total fat (32-34%E), dietary fibre (2.5 g MJ-1 ), α-linolenic acid (0.45%E) and most micronutrients were in good compliance with recommendations. However, intakes of long chain polyunsaturated fatty acids (LCPUFA) (65-80 mg) were low and significant proportions of children had inadequate intakes (< estimated average requirement) of vitamin D and iron. Small proportions of children with intakes exceeding the upper level for retinol, folic acid, zinc, copper and iodine, are unlikely to give rise to adverse health effects. Mean intakes of free sugars (12%E) and salt (3.1 g day-1 ) exceeded recommendations and increased with age, whereas mean intake of saturated fat (15%E) decreased with age. By the age of 4 years, patterns established for intakes of salt, saturated fat and free sugars were unfavourable and similar to those observed in the diets of older children. CONCLUSIONS: Further research is needed to identify dietary strategies that improve the quality of the diet in young children, particularly in relation to excess of saturated fat, free sugars and salt, as well as inadequacy of iron, vitamin D and LCPUFA.

Dietary strategies for achieving adequate vitamin D and iron intakes in young children in Ireland.

BACKGROUND: Inadequate intakes of vitamin D and iron have been reported in young children in Ireland. The present study aimed to identify the main foods determining vitamin D and iron intakes and to model the impact of dietary strategies to improve adequacy of these micronutrients in young children. METHODS: The present study is based on the Irish National Pre-School Nutrition Survey (NPNS), which estimated food and nutrient intakes in a representative sample (n = 500) of children (aged 1-4 years) using a 4-day weighed food record. Dietary strategies were modelled using DaDiet© software (Dazult Ltd, Co. Kildare, Republic of Ireland) and the usual intake distribution, prevalence of inadequate intakes and risk of excessive intakes were estimated using the National Cancer Institute method. RESULTS: Fortified foods and nutritional supplements were the key foods influencing the intakes of vitamin D and iron. Adding a 5 µg day-1 vitamin D supplement, fortifying cow's milk (CM) with vitamin D or replacing CM with growing-up milk (GUM) would modestly increase intakes of vitamin D. A combined strategy of fortifying CM with vitamin D or replacing CM with GUM plus a 5 µg day-1 vitamin D supplement would increase mean intakes of vitamin D (from 3.5 µg day-1 at baseline to ≥11 µg day-1 ) and substantially reduce the prevalence of inadequate intakes (from >95% to 12-36%). Fortifying CM with iron or replacing CM with GUM would increase mean intakes of iron (from 7.3 mg day-1 to >10 mg day-1 ), achieving adequate intakes across all ages. CONCLUSIONS: Based on real food consumption data in a representative sample of Irish children, we have shown that through targeted dietary strategies adequate intakes of iron are achievable and intakes of vitamin D could be greatly improved.

Potential of Earlier Detection and Treatment of Disease-Related Malnutrition with Oral Nutrition Supplements to Release Acute Care Bed Capacity.

A recent systematic review and meta-analysis shows that appropriate use of oral nutrition supplements (ONS) in community patients is associated with a significant reduction in hospitalisations. Given higher use of acute care resource by malnourished versus normally nourished patients, this paper examines the potential to reduce bed utilisation by applying these results to Irish inpatient and malnutrition prevalence data. In 2013, adults admitted to hospital with medium or high malnutrition risk scores used an estimated 36% of adult acute inpatient bed days. Targeted use of ONS in community patients might reduce hospitalisation by 168,438 adult bed days per year, equivalent to 460 beds per day. This is particularly important, given high bed occupancy rates and twelve month daily averages of 254 patients on trolleys. Relevant stakeholders should consider strategies to ensure effective ONS use with a view to improving outcomes and reducing pressure on the acute care system.

Fruit and vegetable consumption as a preventative strategy for non-communicable diseases.

A high intake of fruit and vegetables (FV) has consistently been associated with a reduced risk of a number of non-communicable diseases. This evidence base is largely from prospective cohort studies, with meta-analyses demonstrating an association between increased FV intake and reduced risk of both CHD and stroke, although the evidence is less certain for cancer and diabetes. Controlled intervention trials examining either clinical or intermediate risk factor endpoints are more scarce. Therefore, evidence that FV consumption reduces the risk of disease is so far largely confined to observational epidemiology, which is hampered by some methodological uncertainties. Although increased FV intake is promoted across all dietary guidelines, national surveys confirm that dietary intakes are suboptimal and are not increasing over time. A range of barriers to increasing FV intake exist, including economic, physical and behavioural barriers that must be considered when exploring potential opportunities to change this, considering the feasibility of different approaches to encourage increased FV consumption. Such interventions must include consideration of context, for example, challenges and uncertainties which exist with the whole food system.

Functional anatomy of autobiographical memory recall deficits in depression.

BACKGROUND: Major depressive disorder (MDD) is associated with deficits in recalling specific autobiographical memories (AMs). Extensive research has examined the functional anatomical correlates of AM in healthy humans, but no studies have examined the neurophysiological underpinnings of AM deficits in MDD. The goal of the present study was to examine the differences in the hemodynamic response between patients with MDD and controls while they engage in AM recall. METHOD: Participants (12 unmedicated MDD patients; 14 controls) underwent functional magnetic resonance imaging (fMRI) scanning while recalling AMs in response to positive, negative and neutral cue words. The hemodynamic response during memory recall versus performing subtraction problems was compared between MDD patients and controls. Additionally, a parametric linear analysis examined which regions correlated with increasing arousal ratings. RESULTS: Behavioral results showed that relative to controls, the patients with MDD had fewer specific (p=0.013), positive (p=0.030), highly arousing (p=0.036) and recent (p=0.020) AMs, and more categorical (p<0.001) AMs. The blood oxygen level-dependent (BOLD) response in the parahippocampus and hippocampus was higher for memory recall versus subtraction in controls and lower in those with MDD. Activity in the anterior insula was lower for specific AM recall versus subtraction, with the magnitude of the decrement greater in MDD patients. Activity in the anterior cingulate cortex was positively correlated with arousal ratings in controls but not in patients with MDD. CONCLUSIONS: We replicated previous findings of fewer specific and more categorical AMs in patients with MDD versus controls. We found differential activity in medial temporal and prefrontal lobe structures involved in AM retrieval between MDD patients and controls as they engaged in AM recall. These neurophysiological deficits may underlie AM recall impairments seen in MDD.

A method for assessing dietary intakes of n-3 long-chain polyunsaturated fatty acids and trans fatty acids in an Irish adult population.

The present study aimed to quantify dietary intakes of eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) and trans fatty acids (trans FA) in Irish adults using the North/South Ireland Food Consumption Survey (NSIFCS). To update the NSIFCS database, specific approaches were necessary to select accurate data. Published references were the main data source used to update for EPA and DHA (21.7%), while the UK Nutrient Databank was most frequently used to update for trans FA (46.7%). Total EPA and DHA mean daily intake was 275 mg/day whilst trans FA mean daily intake was 0.72% food energy. Younger adults had significantly lower intakes of EPA and DHA than older adults. The present study shows that dietary EPA and DHA intakes in the Irish adult population are below recommendations, especially among the younger population. Conversely, trans FA intakes are within the recommended value of < 2% food energy.

Long-term follow-up of the STARFlex device for closure of secundum atrial septal defect.

BACKGROUND: There is limited published outcome data on the STARFlex device for transcatheter closure of atrial septal defects (ASD). AIM: To contribute to the long term outcomes of ASD device closure with the STARFlex device. METHODS: Results of a prospective FDA approved clinical trial (1999-2001) from a single institution of the STARFlex device for simple ASD was reviewed. The inclusion criteria included age >or=2 years, isolated secundum ASD, evidence of right ventricular volume overload, and maximum stretched diameter <22 mm. A retrospective review of the original study data with most recent follow-up was performed. Clinical success in the trial was defined as complete closure or residual leak

Measurement and analysis of the flow field in a pulsatile ventricularassist device.

A pneumatically driven ventricular assist device (VAD) of unconventional geometry, designed to mitigate adverse haemostatic phenomena by optimization of flow patterns, was investigated using two-component laser Doppler anemometry (LDA). Data were taken on a rectilinear grid over two orthogonal traverses, allowing synthesis of three-dimensional velocity vectors over most of the grid. The resulting data were examined by two-dimensional and three-dimensional static and animated computer graphic visualizations of the time-varying vector fields. This analysis revealed illuminating and previously unobserved features of the complex flow fields within pulsatile VADs and identified design considerations that bear upon minimization of turbulence and of flow recirculation and stasis. The findings of this study suggest that, while total abolition of undesirable flow phenomena in a diaphragm-type blood pump is probably impossible, comprehensive investigation in vitro can engender considerable improvements in the efficacy of a device.

Feminizing the Face: Combination of Frontal Bone Reduction and Reduction Rhinoplasty.

Gender affirmation surgeries in male-to-female patient transitioning include breast augmentation, genital construction, and facial feminization surgery (FFS). FFS improves mental health and quality of life in transgender patients. The nose and forehead are critical in facial attractiveness and gender identity; thus, frontal brow reduction and rhinoplasty are a mainstay of FFS. The open approach to reduction of the frontal brow is very successful in the feminization of the face; however, risks include alopecia and scarring. Endoscopic brow reduction, in properly selected patients, is minimally invasive with excellent outcomes avoiding these risks. Since both reduction rhinoplasty and frontal brow reduction are routinely performed in FFS, a combined approach provides superior control over the nasal radix and profile when performing surgery on the frontal bone region first followed by nose reduction. We present a case series of four transwomen undergoing frontal bone reduction in combination with a reduction rhinoplasty. All had excellent results with one DVT that resolved with treatment. Transgender patients frequently require multiple operations during their transition increasing their hospital stay and costs. This combined approach offers superior control over the nasofrontal angle and is not only safe but reduces hospitalizations and costs and is a novel indication to reduce gender dysphoria.

Biological interactions mediate context and species-specific sensitivities to salinity.

Toxicants have both sub-lethal and lethal effects on aquatic biota, influencing organism fitness and community composition. However, toxicant effects within ecosystems may be altered by interactions with abiotic and biotic ecosystem components, including biological interactions. Collectively, this generates the potential for toxicant sensitivity to be highly context dependent, with significantly different outcomes in ecosystems than laboratory toxicity tests predict. We experimentally manipulated stream macroinvertebrate communities in 32 mesocosms to examine how communities from a low-salinity site were influenced by interactions with those from a high-salinity site along a gradient of salinity. Relative to those from the low-salinity site, organisms from the high-salinity site were expected to have greater tolerance and fitness at higher salinities. This created the potential for both salinity and tolerant-sensitive organism interactions to influence communities. We found that community composition was influenced by both direct toxicity and tolerant-sensitive organism interactions. Taxon and context-dependent responses included: (i) direct toxicity effects, irrespective of biotic interactions; (ii) effects that were owing to the addition of tolerant taxa, irrespective of salinity; (iii) toxicity dependent on sensitive-tolerant taxa interactions; and (iv) toxic effects that were increased by interactions. Our results reinforce that ecological processes require consideration when examining toxicant effects within ecosystems.This article is part of the theme issue 'Salt in freshwaters: causes, ecological consequences and future prospects'.

Patterns of dairy food intake, body composition and markers of metabolic health in Ireland: results from the National Adult Nutrition Survey.

BACKGROUND: Studies examining the association between dairy consumption and metabolic health have shown mixed results. This may be due, in part, to the use of different definitions of dairy, and to single types of dairy foods examined in isolation. OBJECTIVE: The objective of the study was to examine associations between dairy food intake and metabolic health, identify patterns of dairy food consumption and determine whether dairy dietary patterns are associated with outcomes of metabolic health, in a cross-sectional survey. DESIGN: A 4-day food diary was used to assess food and beverage consumption, including dairy (defined as milk, cheese, yogurt, cream and butter) in free-living, healthy Irish adults aged 18-90 years (n=1500). Fasting blood samples (n=897) were collected, and anthropometric measurements taken. Differences in metabolic health markers across patterns and tertiles of dairy consumption were tested via analysis of covariance. Patterns of dairy food consumption, of different fat contents, were identified using cluster analysis. RESULTS: Higher (total) dairy was associated with lower body mass index, %body fat, waist circumference and waist-to-hip ratio (P<0.001), and lower systolic (P=0.02) and diastolic (P<0.001) blood pressure. Similar trends were observed when milk and yogurt intakes were considered separately. Higher cheese consumption was associated with higher C-peptide (P<0.001). Dietary pattern analysis identified three patterns (clusters) of dairy consumption; 'Whole milk', 'Reduced fat milks and yogurt' and 'Butter and cream'. The 'Reduced fat milks and yogurt' cluster had the highest scores on a Healthy Eating Index, and lower-fat and saturated fat intakes, but greater triglyceride levels (P=0.028) and total cholesterol (P=0.015). CONCLUSION: Overall, these results suggest that while milk and yogurt consumption is associated with a favourable body phenotype, the blood lipid profiles are less favourable when eaten as part of a low-fat high-carbohydrate dietary pattern. More research is needed to better understand this association. CONCLUSION: Overall, these results suggest that although milk and yogurt consumption is associated with a favourable body phenotype, the blood lipid profiles are less favourable when eaten as part of a low-fat high-carbohydrate dietary pattern. More research is needed to better understand this association.

Impaired vasoconstriction to endothelin 1 in patients with NIDDM.

Microvascular disease is an important cause of morbidity in diabetes. There is evidence that impaired autoregulation of blood flow is involved in the pathogenesis of diabetic microangiopathy. The vascular endothelium plays a central role in the regulation of vascular tone. Endothelin (ET)-1 is a potent endothelium-derived vasoconstrictor substance that contributes to basal vascular tone. Impaired vasoconstriction in response to endogenous ET could result in hyperperfusion and subsequent microvascular damage. The purpose of our study was to determine whether vascular responses to locally administered ET-1 are impaired in NIDDM. Nine patients with NIDDM and 12 control subjects underwent cannulation of the nondominant brachial artery. Forearm blood flow (FBF) was measured at baseline and during the drug infusion using strain-gauge venous occlusion plethysmography. ET-1 (5 pmol/min) was infused for 60 min at a rate of 1 ml/min. FBF was measured during the first 5 min of the infusion and at 5-min intervals thereafter. Results were expressed as change in FBF from baseline (ml.100 ml-1.min-1) and were analyzed using repeated measures analysis of variance and Dunnett's test of multiple comparisons. Control subjects showed a gradual onset of vasoconstriction in response to ET-1, which reached maximum at 35 min (1.1 ml.100 ml-1.min-1; P < 0.01). There was no reduction in FBF in response to ET-1 in the diabetic group. The differences between the diabetic and control groups were significant (P < 0.03). In conclusion, ET-1 infused locally at 5 pmol/min does not cause vasoconstriction in patients with NIDDM.

LIPGENE: an EU project to tackle the metabolic syndrome.

LIPGENE is a new 5-year sixth framework EU project involving researchers from 14 EU countries. It will contribute to a reduction in the economic and social burden of the metabolic syndrome through research that will optimise the health impacts of dietary fat change. LIPGENE aims to: account for variation in genotype response to fatty acid modification; enable greater availability of food products that can enhance human health; enhance consumer awareness, and motivate adoption of dietary approaches to disease prevention. A truly integrated programme, LIPGENE incorporates human nutrition, animal nutrition, plant biotechnology, and economic and social/consumer sciences. The human nutrition packages will utilise data from an existing prospective study (SUVIMAX) to identify genotype and dietary interactions as risk factors for the metabolic syndrome. A multi-centre intervention will examine the effects of dietary fat on various risk factors for the metabolic syndrome, while molecular investigations will be supported by mechanistic and functional studies. The British Nutrition Foundation, as dissemination partners for this EU programme, is initiating a wide-reaching programme to disseminate information about the project and its findings. Further details, including lists of upcoming project-related events, are available at www.lipgene.tcd.ie and www.nutrition.org.uk/lipgene.

Effect of dietary supplementation with conjugated linoleic acid on markers of calcium and bone metabolism in healthy adult men.

INTRODUCTION: Conjugated linoleic acid (CLA) has been shown to positively influence calcium and bone metabolism in experimental animals and cells in culture, but there are limited human data available. OBJECTIVE: To investigate the effect of CLA supplementation on biomarkers of calcium and bone metabolism in healthy adult males. DESIGN: The study consisted of a double-blind, placebo-controlled trial in which 60 healthy adult males (aged 39-64 y) were randomly assigned to receive daily either 3.0 g CLA isomer blend (50:50% cis-9,trans-11:trans-10,cis-12 isomers) or a palm/bean oil blend (placebo) for 8 weeks. Urine and blood samples were collected at weeks 0 and 8 and were analysed for biomarkers of calcium and bone metabolism. RESULTS: Supplementation with CLA or placebo for 8 weeks had no significant effects on markers of bone formation (serum osteocalcin and bone-specific alkaline phosphatase) or bone resorption (serum C-telopeptide-related fraction of type 1 collagen degradation products, urinary N-telopeptide-related fraction of type 1 collagen degradation products, urinary pyridinoline and deoxypyridinoline), or on serum or urinary calcium levels. Baseline levels of these biochemical parameters were similar in both groups of subjects. While the placebo had no effect, CLA supplementation resulted in a three-fold increase (P<0.00001) in cis-9,trans-11 CLA isomer in total plasma lipids. CONCLUSION: Under the conditions tested in this double-blind, placebo-controlled trial in adult men, a CLA supplement of mixed isomers did not affect markers of calcium or bone metabolism. Further investigation of the effects of CLA on calcium and bone metabolism in other gender- and age-groups is warranted.

The effects of conjugated linoleic acid supplementation on immune function in healthy volunteers.

OBJECTIVE: To assess the effects of dietary supplementation using two isomeric blends of conjugated linoleic acid (CLA) on immune function in healthy human volunteers. DESIGN: Double-blind, randomised, placebo-controlled intervention trial. SUBJECTS AND INTERVENTION: A total of 55 healthy volunteers (n=20 males, n=35 females) were randomised into one of three study groups who received 3 g/day of a fatty acid blend containing a 50:50 cis-9, trans-11: trans-10, cis-12 CLA isomer blend (2 g CLA), and 80:20 cis-9, trans-11: trans-10, cis-12 (80:20) CLA isomer blend (1.76 g CLA) or linoleic acid (control, 2 g linoleic acid) for 8 weeks. RESULTS: Supplementation with the 80:20 CLA isomer blend significantly (P< or =0.05) enhanced PHA-induced lymphocyte proliferation. CLA decreased basal interleukin (IL)-2 secretion (P< or =0.01) and increased PHA-induced IL-2 and tumor necrosis factor alpha (TNF(alpha)) production (P< or =0.01). However, these effects were not solely attributable to CLA as similar results were observed with linoleic acid. CLA supplementation had no significant effect on peripheral blood mononuclear cells IL-4 production, or on serum-soluble intercellular adhesion molecule-1 (sICAM-1) or plasma prostaglandin E2 (PGE2) or leukotreine B4 (LTB4) concentrations. CONCLUSIONS: This study shows that CLA supplementation had a minimal effect on the markers of human immune function. Furthermore, supplementation with CLA had no immunological benefit compared with linoleic acid.

Exercise responses in patients with IDDM.

OBJECTIVE: The hemodynamic, respiratory, and metabolic responses to exercise were studied in IDDM patients and control subjects to detect diabetic cardiomyopathy. RESEARCH DESIGN AND METHODS: Eight subjects aged 25-40 years with diabetes of at least 10 years' duration were compared with eight control subjects aged 21-46 years. All subjects underwent a progressive incremental bicycle exercise test with measurement of gas exchange, blood glucose, lactate, fat metabolite, and catecholamine levels and two steady-state exercise tests with measurement of cardiac output by a CO2 rebreathing method. A new first-pass radionuclide method was used to measure cardiac ejection fractions (EFs) at rest, peak exercise, and steady-state exercise. RESULTS: The peak achieved oxygen consumption was similar in the diabetic and control subjects (29.9 [25.1-34.6] and 31.4 [26.9-35.9] ml.min-1.kg-1, respectively; mean [95% CI]). There were no significant differences in heart rate, double product, ventilation, respiratory exchange ratio, or ventilatory equivalents for oxygen and CO2 during the incremental test. Glucose levels were higher in the diabetic subjects, but there were no significant differences in levels of lactate, catecholamines, free fatty acids, glycerol, or beta-hydroxybutyrate. Left ventricular EF fell from rest to peak exercise within the diabetic group (66.0% [59.6-72.4] at rest; 53.6% [45.6-61.6] at peak; P < 0.05) but this did not differ significantly from the control group (58.7% [52.3-65.1] at rest; 60.3% [48.9-71.7] at peak). Right ventricular EFs were similar in each group, and there was no reduction in peak filling rate to suggest diastolic dysfunction. The cardiac output responses to exercise were also similar in the two groups. CONCLUSIONS: There is no evidence of impairment of the exercise response in subjects with long-standing diabetes, and the apparent fall in left ventricular EF at peak exercise could be related to hemodynamic adaptation.

Serotonin versus catecholamine deficiency: behavioral and neural effects of experimental depletion in remitted depression.

Despite immense efforts into development of new antidepressant drugs, the increases of serotoninergic and catecholaminergic neurotransmission have remained the two major pharmacodynamic principles of current drug treatments for depression. Consequently, psychopathological or biological markers that predict response to drugs that selectively increase serotonin and/or catecholamine neurotransmission hold the potential to optimize the prescriber's selection among currently available treatment options. The aim of this study was to elucidate the differential symptomatology and neurophysiology in response to reductions in serotonergic versus catecholaminergic neurotransmission in subjects at high risk of depression recurrence. Using identical neuroimaging procedures with [(18)F] fluorodeoxyglucose positron emission tomography after tryptophan depletion (TD) and catecholamine depletion (CD), subjects with remitted depression were compared with healthy controls in a double-blind, randomized, crossover design. Although TD induced significantly more depressed mood, sadness and hopelessness than CD, CD induced more inactivity, concentration difficulties, lassitude and somatic anxiety than TD. CD specifically increased glucose metabolism in the bilateral ventral striatum and decreased glucose metabolism in the bilateral orbitofrontal cortex, whereas TD specifically increased metabolism in the right prefrontal cortex and the posterior cingulate cortex. Although we found direct associations between changes in brain metabolism and induced depressive symptoms following CD, the relationship between neural activity and symptoms was less clear after TD. In conclusion, this study showed that serotonin and catecholamines have common and differential roles in the pathophysiology of depression.