26 research outputs found
Central Administration of Agouti-Related Peptide Increases Food Intake in Japanese Quail
Agouti-related peptide is a 132-amino acid peptide associated with stimulating food intake in birds and mammals. The aim of the present study was to investigate the effect of AgRP in 7-day old Japanese quail. In Experiment 1, we tested 0.25, 0.5 and 1.0 nmol AgRP and found no effect on food intake or water intake over a 3 hour duration. In Experiment 2, we tested we tested 0.25, 0.5 and 1.0 nmol AgRP and found no effect on food or water intake over a 24 hour duration. In Experiment 3, we tested 0.0625 and 0.125 nmol AgRP and found no effect on food intake over a 24 hour duration, but found an increase in water intake 900 minutes following injection. In Experiment 4, we tested 1.5 and 3.0 nmol AgRP and found an increase in food and water intake 900 minutes following injection in quail which received 1.5, but not 3.0, nmol AgRP. In Experiment 5, we found that AgRP had no effect on behaviors other than food intake. These results suggest that AgRP has a stimulatory effect on food intake in Japanese quail
Dietary antioxidants protect gut epithelial cells from oxidant-induced apoptosis
BACKGROUND: The potential of ascorbic acid and two botanical decoctions, green tea and cat's claw, to limit cell death in response to oxidants were evaluated in vitro. METHODS: Cultured human gastric epithelial cells (AGS) or murine small intestinal epithelial cells (IEC-18) were exposed to oxidants – DPPH (3 μM), H(2)O(2) (50 μM), peroxynitrite (300 μM) – followed by incubation for 24 hours, with antioxidants (10 μg/ml) administered as a 1 hour pretreatment. Cell number (MTT assay) and death via apoptosis or necrosis (ELISA, LDH release) was determined. The direct interactions between antioxidants and DPPH (100 μM) or H(2)O(2) (50 μM) were evaluated by spectroscopy. RESULTS: The decoctions did not interact with H(2)O(2), but quenched DPPH although less effectively than vitamin C. In contrast, vitamin C was significantly less effective in protecting human gastric epithelial cells (AGS) from apoptosis induced by DPPH, peroxynitrite and H(2)O(2) (P < 0.001). Green tea and cat's claw were equally protective against peroxynitrite and H(2)O(2), but green tea was more effective than cat's claw in reducing DPPH-induced apoptosis (P < 0.01). Necrotic cell death was marginally evident at these low concentrations of peroxynitrite and H(2)O(2), and was attenuated both by cat's claw and green tea (P < 0.01). In IEC-18 cells, all antioxidants were equally effective as anti-apoptotic agents. CONCLUSIONS: These results indicate that dietary antioxidants can limit epithelial cell death in response to oxidant stress. In the case of green tea and cat's claw, the cytoprotective response exceed their inherent ability to interact with the injurious oxidant, suggestive of actions on intracellular pathways regulating cell death
Inferring causal molecular networks: empirical assessment through a community-based effort
Inferring molecular networks is a central challenge in computational biology. However, it has remained unclear whether causal, rather than merely correlational, relationships can be effectively inferred in complex biological settings. Here we describe the HPN-DREAM network inference challenge that focused on learning causal influences in signaling networks. We used phosphoprotein data from cancer cell lines as well as in silico data from a nonlinear dynamical model. Using the phosphoprotein data, we scored more than 2,000 networks submitted by challenge participants. The networks spanned 32 biological contexts and were scored in terms of causal validity with respect to unseen interventional data. A number of approaches were effective and incorporating known biology was generally advantageous. Additional sub-challenges considered time-course prediction and visualization. Our results constitute the most comprehensive assessment of causal network inference in a mammalian setting carried out to date and suggest that learning causal relationships may be feasible in complex settings such as disease states. Furthermore, our scoring approach provides a practical way to empirically assess the causal validity of inferred molecular networks
Inferring causal molecular networks: empirical assessment through a community-based effort
It remains unclear whether causal, rather than merely correlational, relationships in molecular networks can be inferred in complex biological settings. Here we describe the HPN-DREAM network inference challenge, which focused on learning causal influences in signaling networks. We used phosphoprotein data from cancer cell lines as well as in silico data from a nonlinear dynamical model. Using the phosphoprotein data, we scored more than 2,000 networks submitted by challenge participants. The networks spanned 32 biological contexts and were scored in terms of causal validity with respect to unseen interventional data. A number of approaches were effective, and incorporating known biology was generally advantageous. Additional sub-challenges considered time-course prediction and visualization. Our results suggest that learning causal relationships may be feasible in complex settings such as disease states. Furthermore, our scoring approach provides a practical way to empirically assess inferred molecular networks in a causal sense
Heat Stress Responses in Birds: A Review of the Neural Components
Heat stress is one of the major environmental conditions causing significant losses in the poultry industry and having negative impacts on the world’s food economy. Heat exposure causes several physiological impairments in birds, including oxidative stress, weight loss, immunosuppression, and dysregulated metabolism. Collectively, these lead not only to decreased production in the meat industry, but also decreases in the number of eggs laid by 20%, and overall loss due to mortality during housing and transit. Mitigation techniques have been discussed in depth, and include changes in air flow and dietary composition, improved building insulation, use of air cooling in livestock buildings (fogging systems, evaporation panels), and genetic alterations. Most commonly observed during heat exposure are reduced food intake and an increase in the stress response. However, very little has been explored regarding heat exposure, food intake and stress, and how the neural circuitry responsible for sensing temperatures mediate these responses. That thermoregulation, food intake, and the stress response are primarily mediated by the hypothalamus make it reasonable to assume that it is the central hub at which these systems interact and coordinately regulate downstream changes in metabolism. Thus, this review discusses the neural circuitry in birds associated with thermoregulation, food intake, and stress response at the level of the hypothalamus, with a focus on how these systems might interact in the presence of heat exposure
The physiological, transcriptional and genetic responses of an ozone-sensitive and an ozone tolerant poplar and selected extremes of their F2 progeny
Relatively little is known about the transcriptional response or genetic control of response and adaptation of trees to tropospheric ozone exposure. Such understanding is needed as up to 50% of forests, globally, may be subjected to phytotoxic concentrations of ozone. The physiological, transcriptional and genetic response to ozone was examined in Populus trichocarpa and P. deltoides, which show extreme sensitivity and tolerance to ozone, respectively. Using an inbred F(2) mapping population derived from these two species, we mapped quantitative trait loci (QTL) for traits associated with ozone response, examined segregation of the transcriptional response to ozone and co-located genes showing divergent responses between tolerant and sensitive genotypes with QTL. QTL were identified linking detrimental effects of ozone with leaf and biomass traits and differential responses were found for key genes involved in ethylene production and response
Risk factors for non-communicable diseases among overweight and obese women of Somali background in Oslo, Norway
Background: Non-communicable diseases (NCDs) are the most common causes of morbidity and mortality globally. Somalis are a relatively new immigrant group in Norway and knowledge about their health status and risk factors for NCDs is limited. This study aimed to determine the prevalence of selected risk factors for NCDs among overweight and obese women of Somali background in Oslo, Norway. Methods: Baseline data of an exercise intervention study among women of Somali background (n = 168, recruited between September 2020 and September 2022). Body mass index (BMI) (kg/m2), waist-hip-ratio (WHR), blood pressure, glycated hemoglobin (HbA1c), non-fasting glucose, and blood lipids were measured. Results: Mean (SD) age was 46.8 years (10.4) and BMI was 33.9 kg/m2 (5.1). Mean total cholesterol (TC), low-density lipoprotein (LDL), HbA1c, non-fasting glucose, and blood pressure were within the normal range on average. Per one unit increase in BMI systolic blood pressure (SBP) increased by 0.89 mm/Hg (95%CI: 0.35−1.44, P = 0.002) and diastolic blood pressure (DBP) increased by 0.46 mm/Hg (95%CI: 0.17−0.75 P = 0.002). No relation between BMI and HbA1c, blood lipids, age, education level, number of children in the household, or length of residence in Norway was found. Conclusion: Despite the high BMI, most of the selected risk factors for NCDs had mean values within the normal range. The participants had a low prevalence of diabetes type 2 and hyperlipidemia, although there was a moderate association between BMI and blood pressure. This indicates that it is possible to be obese and be of relatively good health in this population. Trial registration: The study was registered at clinicaltrials.gov NCT04578067
First and Second Transmembrane Segments of α3, α4, β2, and β4 Nicotinic Acetylcholine Receptor Subunits Influence the Efficacy and Potency of Nicotine
Association between cigarette smoking and ovarian reserve among women seeking fertility care.
IntroductionThis study examined the association of smoking with ovarian reserve in a cross-sectional study of 207 women enrolled in the Louisville Tobacco Smoke Exposure, Genetic Susceptibility, and Infertility (LOUSSI) Study and assessed effect modification by NAT2 acetylator phenotype.MethodsInformation on current smoking status was collected using a structured questionnaire and confirmed by cotinine assay. Serum anti-Müllerian hormone (AMH) levels were used to assess ovarian reserve. Diminished ovarian reserve (DOR) was defined as AMH ResultsCurrent smoking status, either passive or active as measured by urinary cotinine assay, was not significantly associated with DOR. For dose-response assessed using self-report, the odds of DOR increased significantly for every additional cigarette currently smoked (Odds ratio, OR:1.08; 95% confidence interval, 95%CI:1.01-1.15); additionally, every 1 pack-year increase in lifetime exposure was associated with an increased odds of DOR among women without PCOS (OR: 1.08 95%CI: 0.99-1.18). These trends appear to be driven by the heavy or long-term smokers. Effect modification by NAT2 genotype was not established.ConclusionA history of heavy smoking may indicate increased risk of diminished ovarian reserve