BACKGROUND & AIMS: BACKGROUND & AIMS:To assess the success rate of a self-propelling nasojejunal feeding tube in patients with acute pancreatitis. METHODS:All patients admitted for acute pancreatitis were included. A self-propelling nasojejunal feeding tube was introduced into the stomach, and gastrointestinal motility was stimulated using metoclopramide. If the tube failed to advance to the ligament of Treitz, a nasojejunal tube was placed endoscopically. RESULTS:A total of 108 patients, 94 with necrotizing pancreatitis (Balthazar D/E) and 14 with nonnecrotizing pancreatitis (Balthazar B/C), were referred for artificial nutrition. In 11 cases, ileus persisted and parenteral nutrition was initiated. Among the remaining 97 patients, 5 refused tube placement. The self-propelling feeding tube was inserted in 92 patients with successful migration to the ligament of Treitz in 61% (n = 56) and failure in 39% (n = 36). Of the 36 patients with an initial failed placement, endoscopic placement of a nasojejunal tube was successful 80% of the time (29 patients). The success rate of a nasojejunal self-propelling feeding tube placement correlated directly with the severity of the acute pancreatitis (92% in B/C vs 61% in D vs 48% in E; P < .05). CONCLUSIONS:Use of a self-propelling nasojejunal tube is a simple technique that can be successfully performed in the majority of patients with acute pancreatitis. The utility of this procedure in the most severe cases of acute pancreatitis continues to pose a challenge.

背景与目标：

BACKGROUND & AIMS: -2

背景与目标： -2

BACKGROUND & AIMS: :Diarrhoea is a common and serious complication of enteral tube feeding. Its pathogenesis involves antibiotic prescription, enteropathogenic colonization and abnormal colonic responses, all of which involve an interaction with the colonic microbiota. Alterations in the colonic microbiota have been identified in patients receiving enteral tube feeding and these changes may be associated with the incidence of diarrhoea. Preventing negative alterations in the colonic microbiota has therefore been investigated as a method of reducing the incidence of diarrhoea. Probiotics and prebiotics may be effective because of their suppression of enteropathogenic colonization, stimulation of immune function and modulation of colonic metabolism. Randomized controlled trials of probiotics have produced contrasting results, although Saccharomyces boulardii has been shown to reduce the incidence of diarrhoea in patients in the intensive care unit receiving enteral tube feeding. Prebiotic fructo-oligosaccharides have been shown to increase the concentration of faecal bifidobacteria in healthy subjects consuming enteral formula, although this finding has not yet been confirmed in patients receiving enteral tube feeding. Furthermore, there are no clinical trials investigating the effect of a prebiotic alone on the incidence of diarrhoea. Further trials of the efficacy of probiotics and prebiotics, alone and in combination, in preventing diarrhoea in this patient group are warranted.

背景与目标： : 腹泻是肠内管喂养的常见且严重的并发症。其发病机制涉及抗生素处方，肠致病性定植和异常结肠反应，所有这些都涉及与结肠微生物群的相互作用。在接受肠管喂养的患者中已经发现了结肠微生物群的变化，这些变化可能与腹泻的发生率有关。因此，已研究了防止结肠微生物群发生负面变化的方法，以减少腹泻的发生率。益生菌和益生元可能是有效的，因为它们抑制肠道致病性定植，刺激免疫功能和调节结肠代谢。益生菌的随机对照试验产生了相反的结果，尽管已证明布拉氏酵母可以减少重症监护病房接受肠内管喂养的患者的腹泻发生率。在食用肠内配方的健康受试者中，益生元低聚果糖已被证明可以增加粪便双歧杆菌的浓度，尽管这一发现尚未在接受肠管喂养的患者中得到证实。此外，尚无临床试验研究单独使用益生元对腹泻发生率的影响。需要进一步试验益生菌和益生元单独或联合使用预防该患者组腹泻的功效。

BACKGROUND & AIMS: :Intra-nucleus accumbens (Acb) infusion of cholinergic muscarinic antagonist, scopolamine (10 microg/0.5 microl), markedly reduced fat intake elicited by intra-Acb treatment of the mu-opioid receptor agonist, DAMGO, with 30 min and 4h pretreatment intervals. Intra-Acb scopolamine infusions also reduced food intake in food-deprived rats, but not water intake in water-deprived rats. Hence, Acb muscarinic manipulations exhibit some specificity for feeding, perhaps via interactions with the striatal opioid system.

背景与目标： : 伏隔核 (Acb) 内输注胆碱能毒蕈碱拮抗剂东pol碱 (10微克/0.5微克)，显着减少了由 μ 阿片受体激动剂DAMGO的Acb内治疗引起的脂肪摄入，预处理间隔30分钟和4小时。Acb内东pol碱输注也减少了食物不足的大鼠的食物摄入量，但没有水不足的大鼠的水摄入量。因此，Acb毒蕈碱的操纵可能通过与纹状体阿片类药物系统的相互作用而表现出一定的喂养特异性。

BACKGROUND & AIMS: :We investigated the effect of chromium (Cr) supplementation on the growth performance, energy metabolites, and hormonal variation in winter-exposed buffalo calves. Twenty-four female buffalo calves were randomly allotted to four dietary treatments (n = 6) for a period of 120 days. Feeding regimen was the same in all the groups, except the animals in the four respective groups were additionally supplemented with 0.0, 0.5, 1.0, and 1.5 mg of Cr/kg DM in the form of CrCl3.6H2O. Calves were monitored daily for physiological variables and dry matter intake (DMI). Blood samples were collected at fortnightly intervals from each buffalo calves to measure concentrations of hormones (insulin, cortisol, and growth hormone), energy metabolites (glucose and non-esterified fatty acids), and plasma mineral levels. After 120 days of feeding trial, buffalo calves fed with Cr had lower (P < 0.05) circulating plasma concentrations of glucose, insulin, and cortisol hormones, whereas plasma thyroid hormone and non-esterified fatty acids concentrations were found similar (P > 0.05) among all the treatments. The results suggested that dietary Cr supplementation influenced plasma Cr levels without affecting the plasma concentrations of other trace minerals. However, physiological variables, nutrient intake, and growth performance of buffalo calves did not differ among all treatments (P > 005). In summary, the current study showed that supplementation of Cr at the level of 1.0 and 1.5 mg of Cr/kg DMI was more effective in improving glucose utilization by increasing potency of insulin hormone and reducing concentration of cortisol hormone. Results also suggested that supplemental Cr also improves blood plasma Cr levels.

背景与目标： : 我们研究了补充铬 (Cr) 对冬季暴露的水牛犊牛的生长性能，能量代谢产物和激素变化的影响。24只雌性水牛被随机分配到四种饮食治疗 (n =   6) 中，为期120天。所有组的喂养方案都是相同的，除了四个相应组的动物另外补充了0.0、0.5、1.0和1.5 mg CrCl3.6H2O形式的Cr/kg DM。每天监测小牛的生理变量和干物质摄入量 (DMI)。每两周从每只水牛犊牛收集血液样本，以测量激素 (胰岛素，皮质醇和生长激素)，能量代谢产物 (葡萄糖和非酯化脂肪酸) 和血浆矿物质水平的浓度。经过120天的喂养试验，饲喂Cr的水牛小牛的血浆葡萄糖，胰岛素和皮质醇激素的循环浓度较低 (p  <  0.05)，而血浆甲状腺激素和非酯化脂肪酸的浓度在所有处理中相似 (p  >  0.05)。结果表明，饮食中添加Cr会影响血浆Cr水平，而不会影响其他微量矿物质的血浆浓度。然而，水牛犊牛的生理变量、营养摄入量和生长性能在所有处理之间没有差异 (p  >  005)。总而言之，当前的研究表明，通过增加胰岛素激素的效力和降低皮质醇激素的浓度，以1.0和1.5 mg Cr/kg DMI的水平补充Cr在改善葡萄糖利用方面更有效。结果还表明，补充Cr还可以改善血浆Cr水平。

BACKGROUND & AIMS: :This study aimed to investigate complementary feeding practices during children's first year of life in Botucatu, SP, Brazil. Practices were described according to the age range and the breastfeeding (BF) practice. Data were collected during a multi-vaccination campaign through the interview of 1,238 individuals who accompanied children younger than one year old being vaccinated. Differences associated with the BF situation were identified by the chi-square test and Fisher's exact test. The early introduction of complementary food was observed, which led to the low frequency of exclusive breastfeeding (36.9% <4 months). Children younger than 4 months old consumed tea (30.7%); children between 4 and 6 months old consumed fruits (54.1%), soups (39.9%) and home-made food (19.2%). Juice was offered only to 15.2% of children younger than 4 months old who were completed weaned, 60% of the children was offered water. Data show that the consistence of the food consumed was inappropriate: children between 6 and 8 months old were offered the family's regular food (48.8%) and children older than 8 months (71.6%) were offered soup. Therefore, interventions focused on complementary feeding are justified on the city.

背景与目标： : 这项研究旨在调查巴西博图卡图 (Botucatu) 儿童出生第一年的补充喂养方式。根据年龄范围和母乳喂养 (BF) 实践描述了实践。在多疫苗接种运动期间，通过对1,238名陪同1岁以下儿童接种疫苗的个体进行访谈收集数据。通过卡方检验和Fisher精确检验确定了与BF情况相关的差异。观察到早期引入辅食，这导致纯母乳喂养的频率较低 (36.9% <4个月)。小于4个月的儿童喝茶 (30.7%); 4至6个月的儿童食用水果 (54.1%)，汤 (39.9%) 和自制食物 (19.2%)。果汁只提供给15.2% 4个月以下的已经断奶的儿童，60% 儿童提供水。数据显示，所食用食物的一致性是不合适的: 为6至8个月大的儿童提供家庭常规食物 (48.8%)，为8个月大 (71.6%) 的儿童提供汤。因此，针对补充喂养的干预措施在城市是合理的。

BACKGROUND & AIMS: :Elasmosaurs were extremely long-necked, aquatic reptiles that used four flippers for locomotion. Their distinctive long neck distinguishes them from all other Mesozoic forms, yet the potential uses and constraints of this structure are poorly understood, particularly with regard to feeding. Several associated series of elasmosaurian cervical vertebrae were used to measure ranges of potential flexion. Two-dimensional models, based on a complete specimen of the Late Cretaceous elasmosaur Aphrosaurus furlongi, were created to measure mobility in both vertical and horizontal planes. Accuracy of the models was assessed through comparative analyses with currently extant vertebrate analogues (e.g. snake, turtle, seal). Results suggest that the elasmosaurian neck was capable of a 75-177 degrees ventral, 87-155 degrees dorsal, and 94-176 degrees lateral range of movement depending upon the thickness of cartilage reconstructed between each vertebra. Neck postures such as a 'swan-like' S-shape are shown to be implausible because they require >360 degrees vertical flexion. However, maintenance of a straight neck while swimming, together with considerable lateral and/or ventral movement during prey capture and feeding are feasible.

背景与目标： : elimmosaurs是非常长颈的水生爬行动物，使用四个鳍状肢进行运动。它们独特的长脖子使它们与所有其他中生代形式区分开来，但是人们对这种结构的潜在用途和限制知之甚少，尤其是在喂养方面。使用几个相关的弹性颈椎系列来测量潜在的屈曲范围。基于晚白垩纪elasmosaurus furlongi的完整标本，创建了二维模型，以测量垂直和水平平面中的迁移率。通过与目前现存的脊椎动物类似物 (例如蛇，乌龟，海豹) 的比较分析来评估模型的准确性。结果表明，根据每个椎骨之间重建的软骨厚度，弹性颈部能够进行75-177度的腹侧运动，87-155度的背侧运动和94-176度的横向运动。颈部姿势 (例如 “天鹅状” 的形状) 显示为不可信的，因为它们需要> 360度的垂直屈曲。但是，游泳时保持直颈，以及在捕获和喂食猎物期间进行相当大的侧向和/或腹侧运动是可行的。

BACKGROUND & AIMS: BACKGROUND:Malnutrition in infants during weaning has been attributed to inappropriate complementary feeding practices and it underlies more than one-third of child mortality in Nigeria. Thus, addressing the influence of complementary feeding practice on nutritional status may be an important approach to reducing the burden of child malnutrition. This cross-sectional study investigated the association between complementary feeding practices among mothers and nutritional status of their infants in Akpabuyo Local Government Area, Nigeria. The study enrolled 330 mother-child pairs from 10 randomly selected out of 32 Health Facilities in Akpabuyo. Socio-demographic information, child and maternal characteristics were obtained using an interviewer-administered questionnaire. Complementary feeding practices were assessed with World Health Organization infant and young child feeding indicators. Nutritional indicators wasting, underweight and stunting were determined. RESULTS:Prevalence of timely introduction of complementary feeding among infants aged 6-8 months was 85.4%, minimum dietary diversity rate was 31.5%, and minimum meal frequency 36.7%, the rate of minimum acceptable diet was 7.3%. One-third (33.3%) of the infants were underweight, 26.4%, wasted and 24.6%, stunted. Children who did not receive timely complementary foods had higher odds for wasting (OR 5.15; 95% CI 1.50-17.73). Children who did not receive the minimum dietary diversity had higher odds for underweight than children who received the minimum dietary diversity (OR 2.07; 95% CI 1.17-3.70). Children who did not receive the minimum feeding frequency were more likely to be stunted than their peers who received the minimum feeding frequency (OR 1.57; 95% CI 1.53-4.03). CONCLUSION:Sub-optimal complementary feeding predisposed to infant's malnutrition.

背景与目标：

BACKGROUND & AIMS: :The prevalence of the metabolic syndrome (MS) is rapidly increasing all over the world. Consequently, there is an urgent need for more effective intervention strategies. Both animal and human studies indicate that lipid oversupply to skeletal muscle can result in insulin resistance, which is one of the characteristics of the MS. C57BL/6J mice were fed a low-fat (10 kcal%) palm oil diet or a high-fat (45 kcal%; HF) palm oil diet for 3 or 28 days. By combining transcriptomics with protein and lipid analyses we aimed to better understand the molecular events underlying the early onset of the MS. Short-term HF feeding led to altered expression levels of genes involved in a variety of biological processes including morphogenesis, energy metabolism, lipogenesis, and immune function. Protein analysis showed increased levels of the myosin heavy chain, slow fiber type protein, and the complexes I, II, III, IV, and V of the oxidative phosphorylation. Furthermore, we observed that the main mitochondrial membrane phospholipids, phosphatidylcholine and phosphatidylethanolamine, contained more saturated fatty acids. Altogether, these results point to a morphological as well as a metabolic adaptation by promoting a more oxidative fiber type. We hypothesize that after this early positive adaptation, a continued transcriptional downregulation of genes involved in oxidative phosphorylation will result in decreased oxidative capacity at a later stage. Together with increased saturation of phospholipids of the mitochondrial membrane this can result in decreased mitochondrial function, which is a hallmark observed in insulin resistance and Type 2 diabetes.

背景与目标： : 代谢综合征 (MS) 的患病率在世界各地迅速增加。因此，迫切需要更有效的干预策略。动物和人体研究都表明，骨骼肌脂质供应过剩会导致胰岛素抵抗，这是MS的特征之一。C57BL/6J小鼠饲喂低脂 (10 kcal %) 棕榈油饮食或高脂 (45 kcal %; HF) 棕榈油饮食3或28天。通过将转录组学与蛋白质和脂质分析相结合，我们旨在更好地了解MS早期发作的分子事件。短期HF喂养导致涉及多种生物学过程 (包括形态发生，能量代谢，脂肪生成和免疫功能) 的基因表达水平改变。蛋白质分析显示，肌球蛋白重链，慢纤维型蛋白以及氧化磷酸化的复合物I，II，III，IV和V的水平升高。此外，我们观察到主要的线粒体膜磷脂，磷脂酰胆碱和磷脂酰乙醇胺含有更多的饱和脂肪酸。总之，这些结果通过促进更多的氧化纤维类型而指向形态和代谢适应。我们假设，在这种早期的积极适应之后，参与氧化磷酸化的基因的持续转录下调将导致后期氧化能力降低。再加上线粒体膜磷脂的饱和度增加，这可能导致线粒体功能下降，这是在胰岛素抵抗和2型糖尿病中观察到的标志。

BACKGROUND & AIMS: :We studied the effects of regular diet (0.35% NaCl/1.1% potassium), high sodium diet (4% NaCl/0.75% potassium), or high sodium and high potassium diet (4% NaCl/2.11% potassium) on blood pressure, plasma renin activity, renal and cerebrovascular lesions, and incidence of stroke and mortality in male stroke-prone spontaneously hypertensive rats (SHRSP). In the first 4 weeks, the rise in blood pressure was higher in high NaCl than in high NaCl/high potassium or regular diet groups. However, by 8 and 12 weeks, the blood pressure in all three groups was similar. After 4 weeks of diet, plasma renin activity was similar in the three groups (3.4 +/- 0.8, 4.1 +/- 0.9, and 5.2 +/- 1.6 ng/ml/hr, in high NaCl, high NaCl/high potassium, and regular diet groups, respectively) and were not related to sodium excretion. After 8 weeks, plasma renin activity was significantly increased only in the high NaCl group (13.7 +/- 3.7 ng/ml/hr), and by 12 weeks plasma renin activity was significantly higher in the high NaCl group (25.3 +/- 3.6 ng/ml/hr) than in the high NaCl/high potassium (11.1 +/- 2.9 ng/ml/hr) or in the regular diet (7.8 +/- 4.6 ng/ml/hr) groups. Moderate to severe renal vascular lesions were first detected in the high NaCl group by 8 weeks of diet. At 12 weeks, renal vascular damage index (RVDI), estimated histologically, was significantly higher in the high NaCl group (RVDI = 79 +/- 14) than in the high NaCl/high potassium (RVDI = 40 +/- 11) and regular diet (RVDI = 7.8 +/- 4.6) groups.(ABSTRACT TRUNCATED AT 250 WORDS)

背景与目标： : 我们研究了常规饮食 (0.35% NaCl/1.1% 钾)，高钠饮食 (4% NaCl/0.75% 钾) 或高钠和高钾饮食 (4% NaCl/2.11% 钾) 对血压，血浆肾素活性，肾脏和脑血管病变，以及男性卒中易发自发性高血压大鼠 (SHRSP) 的卒中发生率和死亡率。在前4周，高NaCl组的血压升高高于高NaCl/高钾组或常规饮食组。然而，到8周和12周时，所有三组的血压都相似。饮食4周后，三组血浆肾素活性相似 (3.4 +/- 0.8，4.1 +/- 0.9和5.2 +/- 1.6 ng/ml/hr，在高NaCl，高NaCl/高钾和常规饮食组，分别与钠排泄无关。8周后，血浆肾素活性仅在高NaCl组显着增加 (13.7/- 3.7 ng/ml/hr)，到12周时，高NaCl组 (25.3 +/- 3.6 ng/ml/hr) 的血浆肾素活性明显高于高NaCl/高钾组 (11.1 +/- 2.9 ng/ml/hr) 或常规饮食 (7.8 +/- 4.6 ng/ml/hr) 组。通过8周的饮食，高NaCl组首先检测到中度至重度肾血管病变。12周时，肾血管损伤指数 (RVDI)，组织学估计，高NaCl组 (RVDI = 79 +/- 14) 显著高于高NaCl/高钾组 (RVDI = 40 +/- 11) 和常规饮食组 (RVDI = 7.8 +/- 4.6)。(摘要截短于250字)

BACKGROUND & AIMS: :It has been widely suggested that saturated fat consumption has fuelled the current obesity epidemic. Macronutrient choices appear to be important not only as potential factors influencing obesity, but also independently as risk factors for diabetes, cardiovascular disease and cancer. The neuropeptide galanin has previously been implicated in the regulation of fat intake, although its precise role has been contested. The present study investigated mice with targeted knockout of the galanin gene (GKO). We demonstrate that, when only a high fat diet (HFD) was available, wild-type (WT) animals consumed significantly more energy than the GKO mice (89.85 +/- 4.57 kJ/day versus 76.84 +/- 3.55 kJ/day, P < 0.001, n = 17 versus 15). Consistent with this, WT animals gained more body weight when fed the HFD than GKO animals (3.48 +/- 0.44 g versus 2.02 +/- 0.62 g, P < 0.001, n = 17 versus 15). In a macronutrient choice scenario, WT mice ate almost three-fold more fat than GKO animals (0.63 +/- 0.02 g versus 0.23 +/- 0.01 g, P < 0.001, n = 18 versus 24). Chronic administration of galanin by mini-osmotic pumps into the lateral ventricle of GKO animals partially reversed the fat avoidance phenotype. Fat intake was significantly lower in the phosphate-buffered saline-treated GKO group compared to galanin-treated GKO animals (0.32 +/- 0.01 g versus 0.38 +/- 0.01 g, P < 0.005, n = 17 versus 17). These data are compatible with the hypothesis that galanin specifically regulates fat intake, and implies that an antagonist to one or more of the galanin receptor subtype(s) may be of use in the treatment of some forms of obesity.

背景与目标： : 人们普遍认为，饱和脂肪的消耗助长了当前的肥胖流行。大量营养素的选择似乎不仅是影响肥胖的潜在因素，而且是糖尿病，心血管疾病和癌症的独立危险因素。神经肽galanin先前与脂肪摄入的调节有关，尽管其确切作用一直存在争议。本研究调查了靶向敲除甘丙肽基因 (GKO) 的小鼠。我们证明，当只有高脂饮食 (HFD) 可用时，野生型 (WT) 动物比GKO小鼠消耗更多的能量 (89.85 +/- 4.57 kJ/天与76.84 +/- 3.55 kJ/天，P <0.001，n = 17对15)。与此一致，WT动物在喂食HFD时比GKO动物获得更多的体重 (3.48 +/- 0.44g对2.02 +/- 0.62g，P <0.001，n = 17对15)。在大量营养素选择方案中，WT小鼠的脂肪几乎比GKO动物多三倍 (0.63 +/- 0.02g对0.23 +/- 0.01g，P <0.001，n = 18对24)。通过微型渗透泵将甘丙肽长期施用到GKO动物的侧脑室中，部分逆转了脂肪回避表型。与甘丙肽处理的GKO动物相比，磷酸盐缓冲盐水处理的GKO组的脂肪摄入量显着降低 (0.32 +/- 0.01g对0.38 +/- 0.01g，P <0.005，n = 17对17)。这些数据与甘丙肽特异性调节脂肪摄入的假设兼容，并暗示对一种或多种甘丙肽受体亚型的拮抗剂可用于治疗某些形式的肥胖症。

BACKGROUND & AIMS: TOPIC:We consider a meta-analysis of randomized controlled trials (RCTs) comparing topical anesthesia alone with topical and intracameral anesthesia for phacoemulsification. CLINICAL RELEVANCE:Topical anesthesia has become an increasingly popular option for day-case cataract surgery. Many surgeons now use supplementary intraoperative intracameral lidocaine, but the evidence base for the supplementary use of intracameral anaesthetic during cataract surgery has never been reviewed systematically. METHODS/LITERATURE REVIEWED:The primary objective is to compare intraoperative pain for phacoemulsifications under topical anesthesia with and without intracameral anesthesia. The secondary objectives are to assess both adverse effects and complications attributable to choice of anesthesia and the need for additional anesthesia during surgery. Searches were made from the Cochrane Central Register of Controlled Trials, Medline, Excerpta Medica database, and Latin American and Caribbean Health Science Information Database up to and including June 8, 2006. RESULTS:Eight RCTs, recruiting a total of 1281 patients, were identified. Our data comparison showed significantly lower intraoperative pain perception in patient groups using supplementary intracameral lidocaine. No significant difference in intraoperative adverse events, corneal toxicity, or the need for supplemental anesthesia was identified. CONCLUSION:Intraoperative pain during cataract surgery under topical anaesthetic is reduced by intracameral lidocaine. Possible adverse effects of intracameral lidocaine cannot be excluded due to significant heterogeneity in outcome measures between different RCTs. Although a statistically significant reduction in intraoperative pain has been demonstrated, it is not yet possible to recommend this additional intervention without reservations.

背景与目标：

BACKGROUND & AIMS: :The injection of a melanocortin peptide or of melanocortin peptide analogues into the cerebrospinal fluid or into the ventromedial hypothalamus in nanomolar or subnanomolar doses induces a long-lasting inhibition of food intake. The effect keeps significant for up to 9 h and has been observed in all animal species so far tested, the most susceptible being the rabbit. The anorectic effect of these peptides is a primary one, not secondary to the shift towards other components of the complex melanocortin-induced behavioral syndrome, in particular grooming. The site of action is in the brain, and the effect is not adrenal-mediated because it is fully exhibited also by adrenalectomized animals. It is a very strong effect, because the degree of feeding inhibition is not reduced in conditions of hunger, either induced by 24 h starvation, or by insulin-induced hypoglycemia, or by stimulation of gamma-aminobutyric acid (GABA), noradrenergic or opioid systems. The microstructural analysis of feeding behavior suggests that melanocortins act as satiety-inducing agents, because they do not significantly modify the latencies to start eating, but shorten the latencies to stop eating. The mechanism of action involves the activation of melanocortin MC(4) receptors, because selective melanocortin MC(4) receptor antagonists inhibit the anorectic effect of melanocortins, while inducing per se a strong stimulation of food intake and a significant increase in body weight. Melanocortins seem to play an important role in stress-induced anorexia, because such condition, in rats, is significantly attenuated by the blockage of melanocortin MC(4) receptors; such a role is not secondary to an increased release of corticotropin-releasing factor (CRF), because, on the other hand, the CRF-induced anorexia is not affected at all by the blockage of melanocortin MC(4) receptors. The physiological meaning of the feeding inhibitory effect of melanocortins, and, by consequence, the physiological role of melanocortins in the complex machinery responsible for body weight homeostasis, is testified by the hyperphagia/obesity syndromes caused by mutations in the pro-opiomelanocortin (POMC) gene, or in the melanocortin MC(4) receptor gene, or in the agouti locus. Finally, recent evidences suggest that melanocortins could be involved in mediating the effects of leptin, and in controlling the expression of neuropeptide Y (NPY).

背景与目标： : 以纳摩尔或亚纳摩尔剂量将黑皮质素肽或黑皮质素肽类似物注射到脑脊液或腹内侧下丘脑中，可长期抑制食物摄入。这种作用在长达9小时内保持显着，并且到目前为止已在所有测试的动物物种中观察到，最易感的是兔子。这些肽的厌食作用是主要的，而不是继发于向复杂的黑皮质素诱导的行为综合征的其他成分的转变，尤其是修饰。作用部位在大脑中，并且该作用不是肾上腺介导的，因为肾上腺切除的动物也完全表现出它。这是非常强烈的作用，因为在饥饿条件下，由于24小时饥饿或胰岛素诱导的低血糖或通过刺激 γ-氨基丁酸 (GABA)，去甲肾上腺素能或阿片类药物系统。喂养行为的微观结构分析表明，黑色素可作为饱腹感的诱导剂，因为它们不会显着改变开始进食的潜伏期，但会缩短停止进食的潜伏期。作用机制涉及黑皮质素MC(4) 受体的激活，因为选择性黑皮质素MC(4) 受体拮抗剂抑制黑皮质素的厌食作用，同时诱导本身对食物摄入的强烈刺激和体重的显着增加。黑素皮质激素似乎在应激诱导的厌食症中起重要作用，因为在大鼠中，黑素皮质激素MC(4) 受体的阻断可显着减弱这种状况; 这种作用并非继发于促肾上腺皮质激素释放因子 (CRF) 的释放增加，因为另一方面，CRF诱导的厌食症完全不受黑皮质素MC(4) 受体阻断的影响。黑素皮质素的摄食抑制作用的生理意义，以及黑素皮质素在负责体重稳态的复杂机器中的生理作用，由亲鸦片黑素皮质素 (POMC) 基因突变引起的食欲亢进/肥胖综合征证明。或在黑皮质素MC(4) 受体基因中，或在agouti基因座中。最后，最近的证据表明，黑素皮质激素可能参与介导瘦素的作用，并控制神经肽Y (NPY) 的表达。

BACKGROUND & AIMS: :Evolutionary transitions between different modes of development in marine invertebrates are thought to be biased toward the loss of feeding larvae. Because the morphology of feeding larvae is complex and nonfeeding larvae or encapsulated embryos with benthic development often have simplified morphologies, it is presumed to be easier to lose a larval stage than to reacquire it. Some authors have gone so far as to suggest that feeding larvae, morphologically similar to the ancestral feeding larvae, cannot be reacquired. However, the larval structures of some groups, most notably gastropods, are often retained in the encapsulated embryos of species that hatch as benthic juveniles. Therefore the re-evolution of feeding larvae using the same structures may be possible in these groups. Here we present the first well-substantiated case for the recent re-evolution of feeding larvae within a clade of direct-developers. DNA sequence data show that Crepipatella fecunda, a species of calyptraeid gastropod with planktotrophic development, is nested within a clade of species with direct development, and that Crepipatella dilatata, a species with direct development, appears to be paraphyletic with respect to C. fecunda. Observation of the embryos of C. dilatata shows that the features necessary for larval feeding and swimming are retained in the encapsulated veligers, suggesting that heterochronic shifts in hatching time and changes in nurse-egg allotment could have resulted in the re-evolution of feeding larvae in this species.

背景与目标： : 海洋无脊椎动物不同发育模式之间的进化过渡被认为偏向于进食幼虫的损失。由于喂食幼虫的形态很复杂，并且底栖发育的非喂食幼虫或包裹的胚胎通常具有简化的形态，因此认为失去幼虫阶段比重新获得幼虫更容易。一些作者甚至建议不能重新获得与祖先喂养幼虫在形态上相似的喂养幼虫。但是，某些类群的幼虫结构，尤其是腹足动物，通常保留在孵化为底栖幼体的物种的包裹胚中。因此，在这些群体中，使用相同的结构喂养幼虫的重新进化是可能的。在这里，我们提出了第一个充分证实的案例，说明最近在直接开发者的进化枝中喂养幼虫的重新进化。DNA序列数据显示，具有浮游营养发育的花萼腹足纲物种Crepipatella fecunda嵌套在具有直接发育的物种进化枝中，而具有直接发育的物种Crepipatella dilatata似乎与C. fecunda具有共生关系。对C. dilatata胚胎的观察表明，幼虫取食和游泳所必需的特征保留在封装的veligers中，这表明孵化时间的异种长期变化和哺乳卵分配的变化可能导致了幼虫的重新进化在这个物种中。

BACKGROUND & AIMS: BACKGROUND:Dopamine (DA) signalling in the brain is necessary for feeding behaviour, and alterations in the DA system have been linked to obesity. However, the precise role of DA in the control of food intake remains debated. On the one hand, food reward and motivation are associated with enhanced DA activity. On the other hand, psychostimulant drugs that increase DA signalling suppress food intake. This poses the questions of how endogenous DA neuronal activity regulates feeding, and whether enhancing DA neuronal activity would either promote or reduce food intake. METHODS:Here, we used designer receptors exclusively activated by designer drugs (DREADD) technology to determine the effects of enhancing DA neuronal activity on feeding behaviour. We chemogenetically activated selective midbrain DA neuronal subpopulations and assessed the effects on feeding microstructure in rats. RESULTS:Treatment with the psychostimulant drug amphetamine or the selective DA reuptake inhibitor GBR 12909 significantly suppressed food intake. Selective chemogenetic activation of DA neurons in the ventral tegmental area (VTA) was found to reduce meal size, but had less impact on total food intake. Targeting distinct VTA neuronal pathways revealed that specific activation of the mesolimbic pathway towards nucleus accumbens (NAc) resulted in smaller and shorter meals. In addition, the meal frequency was increased, rendering total food intake unaffected. The disrupted feeding patterns following activation of VTA DA neurons or VTA to NAc projection neurons were accompanied by locomotor hyperactivity. Activation of VTA neurons projecting towards prefrontal cortex or amygdala, or of DA neurons in the substantia nigra, did not affect feeding behaviour. CONCLUSIONS:Chemogenetic activation of VTA DA neurons or VTA to NAc pathway disrupts feeding patterns. Increased activity of mesolimbic DA neurons appears to both promote and reduce food intake, by facilitating both the initiation and cessation of feeding behaviour.

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