Rapid PCR-based method for herbivore dietary evaluation using plant-specific primers.

Polyphagous pests cause significant economic loss worldwide through feeding damage on various cash crops. However, their diets in agricultural landscapes remain largely unexplored. Pest dietary evaluation in agricultural fields is a challenging task currently approached through visual observation of plant feeding and microscopic identification of semi-digested plant material in pest's guts. While molecular gut content analysis using metabarcoding approaches using universal primers (e.g., rbcl and trnL) have been successful in evaluating polyphagous pest diet, this method is relatively costly and time-consuming. Hence, there is a need for a rapid, specific, sensitive, and cost-effective method to screen for crops in the gut of pests. This is the first study to develop plant-specific primers that target various regions of their genomes, designed using a whole plant genome sequence. We selected Verticillium wilt disease resistance protein (VE-1) and pathogenesis related protein-coding genes 1-5 (PR-1-5) as our targets and designed species-specific primers for 14 important crops in the agroecosystems. Using amplicon sizes ranging from 115 to 407 bp, we developed two multiplex primer mixes that can separate nine and five plant species per PCR reaction, respectively. These two designed primer mixes provide a rapid, sensitive and specific route for polyphagous pest dietary evaluation in agroecosystems. This work will enable future research to rapidly expand our knowledge on the diet preference and range of crops that pests consume in various agroecosystems, which will help in the redesign and development of new crop rotation regimes to minimize polyphagous pest pressure and damage on crops.

Discrete BDNF Neurons in the Paraventricular Hypothalamus Control Feeding and Energy Expenditure.

Brain-derived neurotrophic factor (BDNF) is a key regulator of energy balance; however, its underlying mechanism remains unknown. By analyzing BDNF-expressing neurons in paraventricular hypothalamus (PVH), we have uncovered neural circuits that control energy balance. The Bdnf gene in the PVH was mostly expressed in previously undefined neurons, and its deletion caused hyperphagia, reduced locomotor activity, impaired thermogenesis, and severe obesity. Hyperphagia and reduced locomotor activity were associated with Bdnf deletion in anterior PVH, whereas BDNF neurons in medial and posterior PVH drive thermogenesis by projecting to spinal cord and forming polysynaptic connections to brown adipose tissues. Furthermore, BDNF expression in the PVH was increased in response to cold exposure, and its ablation caused atrophy of sympathetic preganglionic neurons. Thus, BDNF neurons in anterior PVH control energy intake and locomotor activity, whereas those in medial and posterior PVH promote thermogenesis by releasing BDNF into spinal cord to boost sympathetic outflow.

Stress and coping in parents of children with Prader-Willi syndrome: Assessment of the impact of a structured plan of care.

Hyperphagia, developmental delays, and maladaptive behaviors are common in Prader-Willi syndrome (PWS) likely resulting in heightened parental stress. Objectives were to evaluate stress, describe usefulness of coping behaviors, and assess the impact of a structured Plan of Care (PC) on parents with children with PWS. Parents answered Perceived Stress Scale (PSS-14), Coping Health Inventory for Parents (CHIP), and narrative/demographic surveys. The PC was introduced to a cohort of parents after completion of the PSS-14 and CHIP and re-administered 4-6 month after the introduction of the PC. Higher parental stress (n = 57) was observed compared to the general population, and associated with parent's age, number of children living at home, and child's age and residential setting. "Maintaining family integration, cooperation, and an optimistic definition of the situation" was the most useful coping pattern. Thirty-eight parents answered the PSS-14 and CHIP after the PC. Parental stress decreased after the PC (P = 0.035). Coping behaviors related to "maintaining family integration" increased after the PC (P = 0.042). Women and men preferred different coping patterns before and after the PC. In conclusion, parental stress is increased in PWS, and a PC decreased stress and increased coping behaviors related to family stability for parents with children with PWS.

The effects of short-term overfeeding on energy expenditure and nutrient oxidation in obesity-prone and obesity-resistant individuals.

OBJECTIVE: The roles that energy expenditure (EE) and nutrient oxidation play in a predisposition for weight gain in humans remains unclear. SUBJECTS: We measured EE and respiratory exchange ratio (RER) in non-obese obesity-prone (OP; n=22) and obesity-resistant (OR; n=30) men and women following a eucaloric (EU) diet and after 3 days of overfeeding (1.4 × basal energy). RESULTS: Twenty-four hour EE, adjusted for fat-free mass and sex, measured while consuming a EU diet was not different between OP and OR subjects (2367±80 vs 2285±98 kcals; P=0.53). Following overfeeding, EE increased in both OP and OR (OP: 2506±63.7, P<0.01; OR: 2386±99 kcals, P<0.05). Overfeeding resulted in an increase in 24-hour RER (OP: 0.857±0.01 to 0.893±0.01, P=0.01; OR: 0.852±0.01 to 0.886±0.01, P=0.005), with no difference between groups in either the EU or overfeeding conditions (P>0.05). Nighttime RER (∼10pm-6:30am) did not change with overfeeding in OR (0.823±0.02 vs 0.837±0.01, P=0.29), but increased significantly in OP subjects (0.798±0.15 to 0.839±0.15, P<0.05), suggesting that fat oxidation during the night was downregulated to a greater extent in OP subjects following a brief period of overfeeding, as compared with OR subjects who appeared to maintain their usual rate of fat oxidation. Protein oxidation increased significantly in both OP (P<0.001) and OR (P<0.01) with overfeeding, with no differences between OP and OR. CONCLUSION: These results support the idea that overfeeding a mixed diet results in increases in EE and RER, but these increases in EE and RER are likely not responsible for obesity resistance. Adaptive responses to overfeeding that occur during the night may have a role in opposing weight gain.

Ablation of Sim1 neurons causes obesity through hyperphagia and reduced energy expenditure.

Single-minded 1 (Sim1) is a transcription factor necessary for development of the paraventricular nucleus of the hypothalamus (PVH). This nucleus is a critical regulator of appetite, energy expenditure and body weight. Previously we showed that Sim1(+/-) mice and conditional postnatal Sim1(-/-) mice exhibit hyperphagia, obesity, increased linear growth and susceptibility to diet-induced obesity, but no decrease in energy expenditure. Bilateral ablation of the PVH causes obesity due to hyperphagia and reduced energy expenditure. It remains unknown whether Sim1 neurons regulate energy expenditure. In this study, Sim1cre mice were bred to homozygous inducible diphtheria toxin receptor (iDTR) mice to generate mice expressing the simian DTR in Sim1 cells. In these mice, Sim1 neuron ablation was performed by intracerebroventricular (ICV) injection of diphtheria toxin. Compared to controls, mice with Sim1 neuron ablation became obese (with increased fat mass) on a chow diet due to increased food intake and reduced energy expenditure. In post-injection mice, we observed a strong inverse correlation between the degree of obesity and hypothalamic Sim1 expression. The reduction in baseline energy expenditure observed in these mice was accompanied by a reduction in activity. This reduction in activity did not fully account for the reduced energy expenditure as these mice exhibited decreased resting energy expenditure, decreased body temperature, decreased brown adipose tissue temperature, and decreased UCP1 expression suggesting an impairment of thermogenesis. In injected mice, hypothalamic gene expression of Sim1, oxytocin (OXT) and thyrotropin releasing hormone (TRH) was reduced by about 50%. These results demonstrate that Sim1 neurons in adult mice regulate both food intake and energy expenditure. Based on the body of work in the field, feeding regulation by Sim1 neurons likely occurs in both the PVH and medial amygdala, in contrast to energy expenditure regulation by Sim1 neurons, which likely is localized to the PVH.

Neuropeptide Y and agouti-related peptide mediate complementary functions of hyperphagia and reduced energy expenditure in leptin receptor deficiency.

Neuropeptide Y (NPY) and agouti-related peptide (AGRP) can produce hyperphagia, reduce energy expenditure, and promote triglyceride deposition in adipose depots. As these two neuropeptides are coexpressed within the hypothalamic arcuate nucleus and mediate a major portion of the obesity caused by leptin signaling deficiency, we sought to determine whether the two neuropeptides mediated identical or complementary actions. Because of separate neuropeptide receptors and signal transduction mechanisms, there is a possibility of distinct encoding systems for the feeding and energy expenditure aspects of leptin-regulated metabolism. We have genetically added NPY deficiency and/or AGRP deficiency to LEPR deficiency isolated to AGRP cells. Our results indicate that the obesity of LEPR deficiency in AGRP/NPY neurons can produce obesity with either AGRP or NPY alone with AGRP producing hyperphagia while NPY promotes reduced energy expenditure. The absence of both NPY and AGRP prevents the development of obesity attributable to isolated LEPR deficiency in AGRP/NPY neurons. Operant behavioral testing indicated that there were no alterations in the reward for a food pellet from the AGRP-specific LEPR deficiency.

Obesity is a sign - over-eating is a symptom: an aetiological framework for the assessment and management of obesity.

Obesity is characterized by the accumulation of excess body fat and can be conceptualized as the physical manifestation of chronic energy excess. Using the analogy of oedema, the consequence of positive fluid balance or fluid retention, obesity can be seen as the consequence of positive energy balance or calorie 'retention'. Just as the assessment of oedema requires a comprehensive assessment of factors related to fluid balance, the assessment of obesity requires a systematic assessment of factors potentially affecting energy intake, metabolism and expenditure. Rather than just identifying and describing a behaviour ('this patient eats too much'), clinicians should seek to identify the determinants of this behaviour ('why, does this patient eat too much?'). This paper provides an aetiological framework for the systematic assessment of the socio-cultural, biomedical, psychological and iatrogenic factors that influence energy input, metabolism and expenditure. The paper discusses factors that affect metabolism (age, sex, genetics, neuroendocrine factors, sarcopenia, metabolically active fat, medications, prior weight loss), energy intake (socio-cultural factors, mindless eating, physical hunger, emotional eating, mental health, medications) and activity (socio-cultural factors, physical and emotional barriers, medications). It is expected that the clinical application of this framework can help clinicians systematically assess, identify and thereby address the aetiological determinants of positive energy balance resulting in more effective obesity prevention and management.

Altered gene expressions involved in energy expenditure in 5-HT(2C) receptor mutant mice.

Mice with a targeted null mutation of the serotonin 5-HT(2C) receptor gene exhibit hyperphagia that leads to a late-onset obesity. Here we show that oxygen consumption was decreased in fed and fasted obese mutants. No phenotypic differences were observed in uncoupling protein-1 (UCP-1) mRNA levels in brown adipose tissues and UCP-3 mRNA in skeletal muscle. UCP-2 mRNA levels were significantly increased in white adipose tissue (4-fold) and skeletal muscle (47%) in older obese mutant mice, whereas UCP-2 mRNA in liver are significantly increased in both young lean (54% increase) and older obese (52% increase) mutant mice. In contrast, 5-HT(2C) receptor mutants displayed age-dependent decreases in beta 3-adrenergic receptor (beta 3-AR) mRNA levels in white adipose tissue, however, no such changes were observed in brown adipose tissue. These results indicate that a mutation of 5-HT(2C) receptor gene leads to a secondary decrease in beta 3-AR gene expression that is related to enhanced adiposity.

Paternalism and egregious harm: Prader-Willi Syndrome and the importance of care.

Paternalism clashes with the usual liberal model. In this paper I argue that attempts to defend even a limited form of paternalism by liberal authors such as Joel Feinberg, Gerald Dworkin and H.L.A. Hart fail. I propose instead a bivalent model for paternalism that appeals to two separate principles: the no-harm principle and the care-principle. The notion of care discussed by contemporary feminist authors is a fundamental moral archetype that permeates history and culture. I go on to consider the case of patients with Prader-Willi Syndrome and argue that paternalism is not only permissible but imperative in cases in egregious harm. This view is enshrined in common law jurisprudence which dismisses consent as a justification in serious crime.