Food Intake Capacity Research Articles

Stability Analysis of Prey-Predator Model Migration with Holling Type-III Response Function in The Presence of Competition and Toxicity

In this paper, we propose and investigate a prey-predator model with two zones contaminated with heavy metal toxicity, especially copper (Cu), which enter the reservation zone and the unreserved zone in the aquatic environment. The dynamics of the prey population in the ecosystem can migrate from the reservation zone to the unreserved zone or vice versa, while predators are assumed to look for prey in the unreserved zone. The dynamic behavior of the population is expressed as a system of differential equations based on food intake capacity and other factors. We introduce a predator population with a Holling type III predation response function, coupled with inter-specific competition among prey due to overlapping diets and assuming the prey is contaminated with copper metal toxicity. The presence of a positive equilibrium point, namely the interior equilibrium point, is analyzed and investigated for its stability using the Routh-Hurwitz stability test. Numerical simulations are carried out to verify the results of the analysis and dynamics of the system solution. The results of the analysis of the interior equilibrium point T3 in each case is a stable point. This indicates a change in the balance of prey populations and predator populations.

Biflavonoid quercetin protects against cyclophosphamide-induced organ toxicities via modulation of inflammatory cytokines, brain neurotransmitters, and astrocyte immunoreactivity.

Cyclophosphamide use has been associated with increased oxidative stress in cells and tissues. Quercetin's antioxidative properties make it of potential benefit in such conditions of oxidative stress. To assess quercetin's ability to mitigate cyclophosphamide-induced organ toxicities in rats. Sixty rats were assigned into six groups. Groups A and D served as normal and cyclophosphamide control and were fed standard rat chow, groups B and E were fed quercetin supplemented diet (100 mg/kg of feed), while those in groups C and F were fed quercetin at 200 mg/kg of feed. Groups A-C received intraperitoneal (ip) normal saline on days 1 and 2, while D-F received ip cyclophosphamide (150 mg/kg/day on days 1 and 2). On day 21, behavioural tests were carried out, animals were sacrificed and blood samples taken. Organs were processed for histological study. Quercetin reversed cyclophosphamide-induced decrease in body weight, food intake and total antioxidant capacity, and increase in lipid peroxidation (p = 0.001), It also reversed derangement in levels of liver transaminase, urea, creatinine and proinflammatory cytokines (p = 0.001). Improvement in working-memory and anxiety-related behaviours were also observed. Finally, quercetin reversed alterations in levels of acetylcholine, dopamine and brain-derived neurotropic factor (p = 0.021); while reducing serotonin levels and astrocyte immunoreactivity. Quercetin shows significant ability to protect against cyclophosphamide-induced changes in rats.

Molluscicidal activity of Nicotiana tabacum extracts on the invasive snail Pomacea canaliculata

Botanical molluscicides for controlling the invasive snail Pomacea canaliculata have attracted worldwide attention because of their cost and environmental friendliness. Aqueous extracts from discarded tobacco leaf (Nicotiana tobacum) were evaluated for molluscicidal activity against different-sized P. canaliculata under laboratory conditions. The results showed that over 90% of the snails died in 1 g/L tobacco extract within 4 days, and the survival of P. canaliculata was inversely proportional to the snail size, tobacco extract concentration and length of exposure time. Adult males were more susceptible to tobacco extract than females. The snails had few chances to feed or mate in 0.5 g/L tobacco extract, and reproduction was greatly limited in 0.2 g/L. The growth of juvenile snails was inhibited in 0.2 g/L tobacco extract, but adults were unaffected. The antioxidant capacity of P. canaliculata in response to tobacco extract can be size- and sex-dependent, and the activities of superoxide dismutase, catalase, and acetylcholinesterase and the contents of glutathione and malondialdehyde were increased in adult males. These results suggest that discarded tobacco leaves can be useful as a molluscicide for controlling the invasive snail P. canaliculata based on its effects on survival, behaviour, food intake, growth performance and antioxidant capacity.

211-OR: Dual Amylin and Calcitonin Receptor Agonists Increase Mitochondrial Respiratory Capacity in Adipose Tissues of Obese Rat

Dual amylin and calcitonin receptor agonists (DACRAs) are potential therapeutic candidates for treatment of obesity. Preclinical studies have shown favorable effects of DACRAs on appetite regulation contributing to a reduction in body weight. Interestingly, the DACRA-induced effects on weight loss are superior to the effects of a suppressed food intake, suggesting an effect on energy expenditure potentially by targeting the mitochondria. We investigated the effects of long-term treatment with a class of DACRAs, namely KBPs, on body weight, food intake and mitochondrial respiratory capacity (MRC) in Sprague-Dawley rats fed a high-fat diet and treated s.c. with KBPs for 8 weeks. Moreover, a pair-fed (PF) group was used to examine food intake-independent effects of KBPs on MRC. At study end, MRC was analyzed in perirenal (pAT) and inguinal (iAT) adipose tissue using high resolution respirometry. Expectedly, KBP treatment significantly reduced body weight compared to PF and vehicle. PF was successfully KBP-matched in terms of accumulated food intake and the food intake was significantly lower than that of vehicle-treated rats. Coupled and uncoupled MRC supported by complex I+II substrates and fatty acids were significantly greater in iAT and pAT after KBP treatment indicating effects on both carbohydrate and lipid metabolism. Additionally, an increased oligomycin-induced leak-respiration was found to be independent of food intake in iAT. Further analysis will shed light on whether these changes in MRC are a result of an increased mitochondrial content or of the respiratory capacity of each mitochondrion. In conclusion, treatment with KBPs in obese rats is associated with an increased MRC in pAT and iAT and elicits effects additional to those obtained by diet-induced weight loss. This highlights DACRAs’ potential as anti-obesity agents with possible benefits on energy expenditure as a contributing cause to the DACRA-induced weight loss. Disclosure E.A.Petersen: Employee; Nordic Bioscience A/S. I.Blom: None. S.A.Melander: None. M.A.Karsdal: Speaker's Bureau; Pfizer Inc. S.Larsen: None. K.Henriksen: Employee; Nordic Bioscience A/S, Stock/Shareholder; Nordic Bioscience A/S. A.T.Larsen: Employee; Nordic Bioscience A/S. Funding Innovation Fund Denmark

Supplementation with Enterococcus faecium enhances growth performance, intestinal health and immunity of big-belly seahorses (Hippocampus abdominalis) during diet conversion

Diet conversion is a key stage of seahorse aquaculture. Herein, we set up five groups to evaluate the probiotic effects of Enterococcus faecium supplementation on the growth, development, intestinal health, and immunity of big-belly seahorses (Hippocampus abdominalis) during this stage, including control (C) (no E. faecium), H2 (1 ×107 CFU mL−1, every 2 d), H4 (1 ×107 CFU mL−1, every 4 d), L2 (1 ×105 CFU mL−1, every 2 d), and L4 (1 × 105 CFU mL−1, every 4 d) groups. After 48 d culture, concentration and frequency of E. faecium supplementation, as well as their interaction, were confirmed to have significant effects on growth performance of seahorses (P < 0.05). Body weight, specific growth rate, body weight increase, standard length and standard length increase of H4 and L4 groups were significantly higher (P < 0.05); Ovary weight but not testis weight and brood pouch length significantly increased in H4 group (P < 0.05); Feed intake increased (P < 0.05), while feed conversion ratio significantly reduced in H4 group (P < 0.05); Together with the increase of intestinal absorption area (P < 0.05) and digestive enzymes in H4 group, it suggests that the increased growth performance of big-belly seahorses may be attributed to the integrated improvements in food intake, digestion, and absorption capacity. Additionally, significant increase of expression of intestinal immune-related genes, and remodeling of both intestinal microbiota and their functions endowed seahorses with healthier intestinal environment, which resulted in the increase of survival rate by 50% against pathogenic Edwardsiella tarda challenge. Constructing comprehensive evaluation systems of both growth performance and probiotic effects for the first time could help us determine the best application strategy of E. faecium during the diet conversion period of big-belly seahorse aquaculture. This finding may provide a novel reference for the application of E. faecium in seahorse aquaculture.

Studies on the Regulation and Molecular Mechanism of Panax Ginseng Saponins on Senescence and Related Behaviors of Drosophila melanogaster.

In an increasingly aged global population, achieving healthy life expectancy through natural and safe drug interventions is highly desirable. Here we show that total ginsenosides (TGGR), the main active components in the traditional Chinese medicine, ginseng, promote longevity across species. In Drosophila, an intriguing effect of TGGR on lifespan was the relatively narrow treatment window to elicit long-term benefits. TGGR administration during early adulthood, and especially during midlife, was sufficient to extend lifespan in both sexes. TGGR did not increase lifespan by reducing food intake or reproductive capacity; rather, TGGR increased the fertility of male Drosophila. TGGR augmented healthspan readouts associated with youth and with healthy aging, such as motility, intestinal barrier integrity, and biorhythm homeostasis. TGGR treatment also improved some types of stress resistance in both sexes, including increased tolerance to starvation and oxidation, and shifting “aged” gene expression patterns toward “healthy” patterns seen in the young. Gene expression, pharmacological and genetic epistatic analyses demonstrated that TGGR effects require normal expression of genes involved in insulin, TOR and MAPK signaling. The positive effects of TGGR on both healthspan and lifespan, coupled with its mechanism of action via evolutionarily conserved signaling pathways, demonstrate it to be a promising anti-aging drug.

Carry‐over effects of larval food stress on adult energetics and life history in a nectar‐feeding butterfly

Abstract Stressful juvenile developmental conditions can affect performance and fitness later in life. In holometabolous insects such as butterflies, development under stressful conditions may lead to smaller adult size, lower reproductive output, and shorter lifespan. However, how larval developmental stress affects energy intake and expenditure in adult individuals is poorly understood. We subjected last‐instar larvae of Speyeria mormonia Edwards (Lepidoptera: Nymphalidae) to periodic dietary restriction (DR) to examine the allocation of energy and nutrients among different life history processes. We measured adult food intake, resting metabolic rate (RMR), metabolic flight capacity, lifespan, and reproductive output. Consistent with pressure to disperse from a poor environment while maintaining offspring number, we predicted that stressed individuals would have increased adult food intake and higher flight capacity. Adult body size was strongly reduced. Contrary to predictions, we found no compensatory adult feeding. Mass‐adjusted flight metabolic rate was reduced, suggesting poor dispersal capacity. Larval DR did not affect adult lifespan, nor did the rate of metabolic senescence change. Larval DR did affect RMR, as stressed females had a steeper slope between RMR and body mass, which may reflect differences in physiological activity due to condition. Fecundity decreased less than predicted based on body mass. Instead of investing in flight capacity, females increased relative allocation to reproduction, which may partly buffer against poor environmental conditions. Understanding the interplay of energy acquisition and allocation to life history traits across the life cycle is vital for predicting responses to environmental change.

Melatonin as a Multipotent Component of Fish Feed: Basic Information for Its Potential Application in Aquaculture

In vertebrates, melatonin (N-acetyl-5-methoxy-tryptamine, MEL) is synthesized from L-tryptophan (L-Trp), primarily in the pineal gland and additionally in several non-pineal tissues, including enterochromaffin cells of the gastrointestinal tract. The biosynthesis of MEL in the pinealocytes exhibits a daily rhythm with a nocturnal peak in synchronization with the dark phase of an environment. However, the temporal pattern of the gut melatoninergic system in fish is known to be synchronized with one or more non-photic external cue(s), of which most notable include the components of food and feeding time in a daily cycle. Experimental findings on the use of L-Trp (5-fold to −8-fold higher with respect to standard) as a fish food supplement suggest that it has a stimulatory influence on gut MEL synthesis that ultimately leads to elevated levels of plasma MEL. Several studies employing MEL as a fish feed additive report variable responses in relation to the physiological functions of the fish and its doses of application and modes of exposure. Oral administration of MEL (validated dose in general: 200 mg/kg fish food) causes an increase in gut MEL concentrations, food intake capacity, and micronutrient selection ability of fish, as well as enhanced activity of antioxidative enzymes and/or reduced levels of biological stress markers like plasma cortisol and lactate. The application of MEL with the doses of 50 and 250 mg/kg fish food to balanced diet results in precious maturation of gonads, high live sperm rate, and good quality seeds in catfish. A few studies on different fish groups administered with MEL through tank water reveal a significant increase in the fecundity rate, percentage of fertilization, and the number of hatched embryos. MEL injection through intraperitoneal or intramuscular routes also elicits variable responses in fish. Several studies suggest a major protective role of endogenous MEL against gastric ulcer induced by pathogenic bacterial infection. Taken together, MEL seems to be a multipotent physiological candidate involved in the regulation of a variety of body functions ranging from the synchronization of vital activities with environmental variables to the timing of reproduction in a changing system, from the acceleration of body growth to the determination of a pattern of development, and from the reduction of oxidative stress to the protection against microbial infections. Because aquaculture aims at substantially improving the quality and quantity of available aquatic resources employing convenient, consistent, and commercially exploitable measures, we find the reasons to suggest that the use of MEL or its precursor L-Trp as a fish food supplement may open up a new vista of aquaculture and, hence, present this review with an attempt to present the basic information on this area of interest to justify the hypothesis.

Pulmonary impairment in type 2 diabetic rats and its improvement by exercise.

We aimed to evaluate whether the streptozotocin-induced diabetic model can generate lung functional, histological and biochemical impairments and whether moderate exercise can prevent these changes. Wistar rats were assigned to control (CTRL), exercise (EXE), diabetic (D) and diabetic with exercise (D+EXE) groups. We used the n5-STZ model of diabetes mellitus triggered by a single injection of streptozotocin (STZ, 120mg/kg b.w., i.p.) in newborn rats on their 5th day of life. EXE and D+EXE rats were trained by running on a motorized treadmill, 5days a week for 9weeks. Blood glucose, body weight, food intake, exercise capacity, lung mechanics, morphology, and antioxidant enzymatic activity were analysed. On the 14th week of life, diabetic rats exhibited a significant impairment in post-prandial glycaemia, glucose tolerance, body weight, food intake, lung function (tissue viscance, elastance, Newtonian resistance and hysteresis), morphological parameters, redox balance and exercise capacity. Physical training completely prevented the diabetes-induced alterations, except for those on fasting blood glucose, which nevertheless remained stable. Mild diabetes in n5-STZ-treated rats jeopardized pulmonary mechanics, morphology and redox balance, which confirms the occurrence of diabetes-induced pneumopathy. Moreover, moderate exercise completely prevented all diabetes-induced respiratory alterations.

Protein contain in Cyprinus carpio (Ham.) of experimental and control fishes due to administration of ovaprim, ovatide and pituitary gland extract at Fish Seed Production Centre, Paithan, Aurangabad, Maharashtra State, India

Protein contain is a cornerstone mechanism and form part and parcel of nutritive value in particular rely on season, food intake, breeding and spawning capacity. The protein contain in the fish body constitute as a firsthand source of energy for physiological functions incorporating reproduction. Present investigation display that variations in the protein is observed from the mature fishes of Indian major carps such as Cyprinus carpio comprises 20 to 50cm selected for the estimation of protein study considered as experimental and control fishes upon administration of PGE, ovaprim and ovatide synthetic hormonal doses to the male and female sex ratio separately. Protein in the liver of female major carps may be because of vitellogenin, a lipoprotein which is synthesized in the liver and is transported to the ovary (Wallace, 1985). Moreover, gonadal protein enhanced with maturation amongst these fishes. Protein estimation represents the variations throughout the study period amongst the muscle, gonad and liver. After hormonal injections are given then fishes are kept in the breeding pool at the Fish Seed Production Centres (FSPC) located near Paithan barrage. The protein is estimated upon satisfactory administration of hormonal doses Pituitary Gland Extract and by other two synthetic hormonal doses viz. Ovaprim and Ovatide. Study is conducted during 2013 to 2014.

Adaptive differentiation of growth, energetics and behaviour between piscivore and insectivore juvenile rainbow trout along the Pace-of-Life continuum.

Adaptive trade-offs are fundamental mechanisms underlying phenotypic diversity, but the presence of generalizable patterns in multivariate adaptation and their mapping onto environmental gradients remain unclear. To understand how life history affects multivariate trait associations, we examined relationships among growth, metabolism, anatomy and behaviour in rainbow trout juveniles from piscivore versus insectivore ecotypes along an experimental gradient of food availability. We hypothesized that (a) selection for larger size in piscivorous adults would select for higher juvenile growth at the cost of lower active metabolism; (b) elevated growth of piscivores would be supported by a greater productivity of their natal stream and more proactive foraging behaviours and (c) general patterns of multivariate trait associations would match the predictions of the Pace-Of-Life Syndrome. Relative to insectivores, piscivorous fry showed a pattern of higher growth (+63%), maximum food intake (+33%), growth efficiency (+41%) and standard metabolic rate (SMR; +47%), but lower active metabolic capacity (maximum metabolic rate [MMR; -17%], aerobic scope [AS; -48%]), suggesting that faster piscivore growth is supported by greater food intake and digestive capacity but is traded-off against lower scope for active metabolism. A similar trade-off appeared among organ systems, with piscivorous fry exhibiting an 83% greater investment in average mass of organs associated with food consumption and processing (i.e. stomach and intestine), but an apparently smaller relative investment in organs involved in cardiovascular or cognitive activities (heart and brain, respectively). Higher invertebrate drift in their natal rearing habitat, quicker behavioural transition to a novel food source and lower anxiety after a frightening event in piscivorous fry suggest that faster growth requires both proactive foraging behaviours and higher prey availability in the environment. Finally, the sampling of replicate insectivore populations confirmed their lower juvenile growth (-73% on average) and reduced environmental productivity of their natal streams (-45% lower drift abundance) relative to the piscivore ecotype. Our results suggest that selection for large adult body size influences selection on high juvenile growth, high basal metabolism and proactive behaviours, and that the intense phenotypic divergence between piscivorous and insectivorous rainbow trout may be constrained by environmental productivity.

Usefulness of Carnitine Supplementation for the Complications of Liver Cirrhosis.

Carnitine is a vitamin-like substance that regulates lipid metabolism and energy production. Carnitine homeostasis is mainly regulated by dietary intake and biosynthesis in the organs, including the skeletal muscle and the liver. Therefore, liver cirrhotic patients with reduced food intake, malnutrition, biosynthetic disorder, and poor storage capacity of carnitine in the skeletal muscle and liver are more likely to experience carnitine deficiency. In particular, liver cirrhotic patients with sarcopenia are at a high risk for developing carnitine deficiency. Carnitine deficiency impairs the important metabolic processes of the liver, such as gluconeogenesis, fatty acid metabolism, albumin biosynthesis, and ammonia detoxification by the urea cycle, and causes hypoalbuminemia and hyperammonemia. Carnitine deficiency should be suspected in liver cirrhotic patients with severe malaise, hepatic encephalopathy, sarcopenia, muscle cramps, and so on. Importantly, the blood carnitine level does not always decrease in patients with liver cirrhosis, and it sometimes exceeds the normal level. Therefore, patients with liver cirrhosis should be treated as if they are in a state of relative carnitine deficiency at the liver, skeletal muscle, and mitochondrial levels, even if the blood carnitine level is not decreased. Recent clinical trials have revealed the effectiveness of carnitine supplementation for the complications of liver cirrhosis, such as hepatic encephalopathy, sarcopenia, and muscle cramps. In conclusion, carnitine deficiency is not always rare in liver cirrhosis, and it requires constant attention in the daily medical care of this disease. Carnitine supplementation might be an important strategy for improving the quality of life of patients with liver cirrhosis.

Hypothalamic AMPKα2 regulates liver energy metabolism in rainbow trout through vagal innervation.

Hypothalamic AMPK plays a major role in the regulation of whole body metabolism and energy balance. Present evidence has demonstrated that this canonical mechanism is evolutionarily conserved. Thus, recent data demonstrated that inhibition of AMPKα2 in fish hypothalamus led to decreased food intake and liver capacity to use and synthesize glucose, lipids, and amino acids. We hypothesize that a signal of abundance of nutrients from the hypothalamus controls hepatic metabolism. The vagus nerve is the most important link between the brain and the liver. We therefore examined in the present study whether surgical transection of the vagus nerve in rainbow trout is sufficient to alter the effect in liver of central inhibition of AMPKα2. Thus, we vagotomized (VGX) or not (Sham) rainbow trout and then intracerebroventricularly administered adenoviral vectors tagged with green fluorescent protein alone or linked to a dominant negative isoform of AMPKα2. The inhibition of AMPKα2 led to reduced food intake in parallel with changes in the mRNA abundance of hypothalamic neuropeptides [neuropeptide Y (npy), agouti-related protein 1 (agrp1), and cocaine- and amphetamine-related transcript (cartpt)] involved in food intake regulation. Central inhibition of AMPKα2 resulted in the liver having decreased capacity to use and synthesize glucose, lipids, and amino acids. Notably, these effects mostly disappeared in VGX fish. These results support the idea that autonomic nervous system actions mediate the actions of hypothalamic AMPKα2 on liver metabolism. Importantly, this evidence indicates that the well-established role of hypothalamic AMPK in energy balance is a canonical evolutionarily preserved mechanism that is also present in the fish lineage.

Migration Takes Extra Guts for Juvenile Songbirds: Energetics and Digestive Physiology During the First Journey

Many birds undertake long migrations when they are only a few months of age. Although they are typically of adult body size, their performance and survival are often poor compared to adults. This differential performance could be due to lack of experience, selection against poor-performing cohort members, or inherent constraints of continuing physiological and morphological maturation of juveniles. Limited evidence suggests that digestive and muscle physiology of juveniles during their first migration may differ from that of adults. We compared body composition, metabolic rate, and digestive physiology between juvenile and adult passerines during fall migration. First, we measured fat and lean masses by quantitative magnetic resonance, and organ and muscle masses of salvaged carcasses of fall migrants from four passerine species. In general, juveniles had more lean mass and heavier digestive organs (especially liver) than adults in hermit thrushes (Catharus guttatus), Swainson’s thrushes (Catharus ustulatus), ovenbirds (Seiurus aurocapilla), and white-throated sparrows (Zonotrichia albicollis). Principal components analysis of all organs and muscles revealed that juveniles for three of four species had overall larger digestive components and smaller flight muscles than adults. We then used open-flow respirometry to measure basal metabolic rates (BMRs) of juvenile and adult Swainson’s thrushes and white-throated sparrows captured in fall at a migratory stopover site. Controlling for a significant effect of body mass, juveniles had 6% higher BMRs than adults in both species. We then conducted total collection mass balance feeding trials with fall migratory Swainson’s thrushes and white-throated sparrows. Juvenile thrushes had greater metabolizable energy intake than adults, which was achieved through higher food intake rather than greater utilization efficiency. Age classes of white-throated sparrows did not differ in these measures of digestive performance, although juveniles had greater food intake capacity at low lean body masses. We propose that age-related differences in foraging ecology, diet composition and energy requirements may be responsible for larger digestive organs of juvenile migrants. Larger guts may allow juveniles to consume more food or a more dilute diet, but may contribute to higher BMRs.

Transjejunostomy Stent Placement in Patients With Malignant Small-Bowel Obstructions

The objective of our study was to evaluate the clinical effectiveness and safety of transjejunostomy stent placement in patients with malignant small-bowel obstructions (SBOs). Twenty-three patients (age range, 20-81 years) who underwent transjejunostomy stent placement between March 2009 and December 2016 for one (n = 20) or two (n = 3) malignant SBOs from advanced abdominal and pelvic malignancies were included in our study. Percutaneous jejunostomy was created 30-100 cm upstream to malignant SBOs and was immediately followed by stent placement through the jejunostomy stoma during the same session. A retrospective analysis was conducted for technical success, bowel decompression, improvement of obstructive symptoms (3-point scale), improvement of food intake capacity (4-point scale), and procedure-related complications. Stent placement was technically successful in 22 of 23 patients (95.7%). Bowel decompression was confirmed by enterography (n = 21) and CT (n = 16). Obstructive symptoms improved partially (n = 9) or completely (n = 13) within 2 weeks after the procedure. Food intake capacity improved by 3 points in one patient, 2 points in seven patients, and 1 point in 14 patients (p < 0.0001). Major complications (n = 3, 13.0%), including localized peritonitis (n = 2) and bowel perforation (n = 1), were successfully treated conservatively. Transjejunostomy stent placement is an effective treatment in patients with malignant SBOs. It is technically feasible in most patients (95.7%) and provides substantial symptomatic improvement. Procedure-related complications are not rare but can be managed conservatively.

P53-upregulated-modulator-of-apoptosis (PUMA) deficiency affects food intake but does not impact on body weight or glucose homeostasis in diet-induced obesity.

BCL-2 proteins have been implicated in the control of glucose homeostasis and metabolism in different cell types. Thus, the aim of this study was to determine the role of the pro-apoptotic BH3-only protein, p53-upregulated-modulator-of-apoptosis (PUMA), in metabolic changes mediated by diet-induced obesity, using PUMA deficient mice. At 10 weeks of age, knockout and wild type mice either continued consuming a low fat chow diet (6% fat), or were fed with a high fat diet (23% fat) for 14–17 weeks. We measured body composition, glucose and insulin tolerance, insulin response in peripheral tissues, energy expenditure, oxygen consumption, and respiratory exchange ratio in vivo. All these parameters were indistinguishable between wild type and knockout mice on chow diet and were modified equally by diet-induced obesity. Interestingly, we observed decreased food intake and ambulatory capacity of PUMA knockout mice on high fat diet. This was associated with increased adipocyte size and fasted leptin concentration in the blood. Our findings suggest that although PUMA is dispensable for glucose homeostasis in lean and obese mice, it can affect leptin levels and food intake during obesity.

Safety and efficacy of radiological percutaneous jejunostomy for decompression of malignant small bowel obstruction

This study aimed to evaluate the safety and efficacy of percutaneous radiological jejunostomy (PRJ) and stent placement in patients with malignant small bowel obstructions (MSBO). A total of 21 patients (mean age 60 years) with single (n = 4) or multiple (n = 17) MSBO underwent PRJ following jejunopexy. The medical records and imaging studies were retrospectively reviewed to evaluate the technical/clinical success and complications. Clinical success was determined by symptomatic relief and radiologic bowel decompression. PRJ using a 12- or 14-F drainage catheter was technically successful in all patients. Eleven patients required placement of an 18-F nasogastric tube across one (n = 3), two (n = 6) and three (n = 2) obstructions to achieve clinical success. Subsequently, self-expandable stents were placed through the PRJ tracts to recanalise MSBO in four patients. Clinical success was achieved in 18 patients (85.7 %). The median food intake capacity score improved from 4.0 to 2.0 (P = 0.001). There were one major (peritonitis, 4.8 %) and six minor complications (28.6 %) PRJ using a nasogastric tube across the obstructions is an effective palliative treatment for MSBO. The PRJ tract can be used as an approach route for stent placement to recanalise MSBO. However, dedicated devices should be developed to reduce frequent procedure-related complications. • Bowel decompression provides palliative treatment in malignant small bowel obstruction • Percutaneous radiological jejunostomy (PRJ) is a safe and effective palliative treatment. • Long tube placement across obstructions facilitates adequate drainage of multiple bowel obstructions. • PRJ tract can be used for stent placement to approach MSBO recanalisation.

A pilot study on the ontogeny of digestive physiology in Japanese macaques (Macaca fuscata)

An assumption based on the Jarman–Bell principle suggests a positive relationship between body size and the digestive efficiency in animals, where smaller animals are less effective at digesting fibrous food due to shorter digesta passage. To examine the effect of body size within a species and explore a potential physiological background of ontogenetic diet shifts, we measured food intake, digestibility, digesta passage and gut fill in nine Japanese macaques, including three juveniles/subadult animals. Although these three showed a comparable digestive efficiency as the older animals on a low-fiber diet, they did not achieve the long retention times of adults in spite of similar levels of indigestible food intake and gut capacity. While the limited sample size would not allow generalized conclusions on ontogenetic digestive development in primates, this study suggests additional, yet unexplored effects other than food intake, digestion and gut capacity on digesta retention during ontogeny.

Effect of cold exposure on energy budget and thermogenesis during lactation in Swiss mice raising large litters

SummaryIn Swiss mice sustained energy intake (SusEI) during peak lactation has been previously suggested to be constrained by the capacity of the mammary glands to produce milk, supporting the “peripheral limitation” hypothesis. Here we experimentally examined if SusEI in these mice was not only limited peripherally but also constrained by the ability to dissipate heat. Female Swiss mice were provided with additional offspring above their natural litter sizes and were maintained during lactation either in warm (23°C) or cold (5°C) conditions. Food intake, thermogenesis, litter size and mass, and the weight of the mammary glands were measured. No differences were observed in asymptotic food intake at peak lactation, litter mass and thermogenesis between females raising litters of different size. Cold-exposed females increased food intake and thermogenic capacity, but weaned significantly smaller and lighter litters with smaller pup sizes compared with females in warm conditions. The weight of the mammary glands did not differ between warm and cold-exposed females, but within temperatures was positively related to litter mass. These data suggested that cold exposure increased food intake, but had no effect on the capacity of the mammary glands to secret milk because they were already working maximally in the females raising larger litters. The factors causing this limit in the mammary capacity remain elusive.

Herbivorous reptiles and body mass: Effects on food intake, digesta retention, digestibility and gut capacity, and a comparison with mammals

Differences in the allometric scaling between gut capacity (with body mass, BM 1.00) and food intake (with BM 0.75) should theoretically result in a scaling of digesta retention time with BM 0.25 and therefore a higher digestive efficiency in larger herbivores. This concept is an important part of the so-called ‘Jarman–Bell principle’ (JBP) that explains niche differentiation along a body size gradient in terms of digestive physiology. Empirical data in herbivorous mammals, however, do not confirm the scaling of retention time, or of digestive efficiency, with body mass. Here, we test these concepts in herbivorous reptiles, adding data of an experiment that measured food intake, digesta retention, digestibility and gut capacity in 23 tortoises ( Testudo graeca, T. hermanni , Geochelone nigra, G. sulcata, Dipsochelys dussumieri) across a large BM range (0.5–180 kg) to a literature data collection. While dry matter gut fill scaled to BM 1.07 and dry matter intake to BM 0.76, digesta mean retention time (MRT) scaled to BM 0.17; the scaling exponent was not significantly different from zero for species > 1 kg. Food intake level was a major determinant of MRT across reptiles and mammals. In contrast to dietary fibre level, BM was not a significant contributor to dry matter digestibility in a General Linear Model. Digestibility coefficients in reptiles depended on diet nutrient composition in a similar way as described in mammals. Although food intake is generally lower and digesta retention longer in reptiles than in mammals, digestive functions scale in a similar way in both clades, indicating universal principles in herbivore digestive physiology. The reasons why the theoretically derived JBP has little empirical support remain to be investigated. Until then, the JBP should not be evoked to explain niche differentiation along a body size axis in terms of digestive physiology.