Zooplankton spine induces aversion in small fish predators

The spined cladoceran Bythotrephes cederstroemi is protected from small fish predators due to the difficulty small fish have in ingesting the spine. Juvenile yellow perch (Perca flavescens) 50–60 mm in length were offered Bythotrephes with alternative prey available in two experiments. First, perch were observed as they gained experience with Bythotrephes and developed aversion to the zooplankter. Perch initially attacked and captured Bythotrephes . However, they struggled to ingest the spined zooplankter, rejected and recaptured it many times, and finally ceased to attack it. Second, perch were offered Bythotrephes with varying portions of the spine removed to clarify the spine's role in inducing such behaviors. Perch showed greater preference to attack nospine and half-spine Bythotrephes , and were less likely to reject and more likely to ingest Bythotrephes with the spine removed. For small or young fish that forage on zooplankton in lakes where Bythotrephes is present, aversion is an efficient response to the conspicuous but unpalatable spined cladoceran. However, aversion allows Bythotrephes , also a predator on zooplankton, to more effectively compete with young fish without an increase in predation risk.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47794/1/442_2004_Article_BF00317591.pd

Low-calcium diet prevents fructose-induced hyperinsulinemia and ameliorates the response to glucose load in rats

BACKGROUND: Consuming a fructose-rich diet leads to hyperinsulinemia, impaired glucose tolerance, and insulin resistance. In humans, the consumption of high levels of refined sugars often coincides with a diet containing suboptimal levels of calcium. Calcium and carbohydrate metabolism interact, so there is potential for fructose to have different health outcomes depending on whether the diet is calcium-rich or calcium-poor. METHODS: We evaluated the metabolic effects of feeding fructose to rats that were maintained on either a calcium-replete diet or a low-calcium diet. Growing male Sprague Dawley rats were fed diets based on the AIN-93G formulation, with the main source of carbohydrate derived either from a mixture of cornstarch and sucrose or from fructose. Half the rats given each carbohydrate source were fed calcium at recommended levels (125 mmol/kg Ca(2+)); the others were fed a diet low in calcium (25 mmol/kg Ca(2+)). At various times, glucose and insulin tolerance tests were conducted to assess glucose metabolism. RESULTS: Rats fed low-calcium diet had lower fasting insulin levels irrespective of the carbohydrate source they ate. They had a normal glycemic response to a glucose load and did not develop hyperinsulinemia under conditions of fructose feeding. The drop in blood glucose levels in response to insulin injection was larger in rats fed low-calcium diet than in those fed calcium-replete diet. CONCLUSIONS: Low-calcium diet prevented fructose-induced hyperinsulinemia and improved glucose handling under conditions of fructose feeding. Potential mechanisms underlying these effects of the low-calcium diet remain to be determined, but possibilities include impairment of insulin release from the pancreas and improved peripheral insulin sensitivity

Preference for pharmaceutical formulation and treatment process attributes

Katie D Stewart,1 Joseph A Johnston,2 Louis S Matza,1 Sarah E Curtis,2 Henry A Havel,3 Stephanie A Sweetana,3 Heather L Gelhorn1 1Outcomes Research, Evidera, Bethesda, MD, USA; 2Global Patient Outcomes & Real World Evidence, 3Small Molecule Design and Development, Eli Lilly & Company, Indianapolis, IN, USA Purpose: Pharmaceutical formulation and treatment process attributes, such as dose frequency and route of administration, can have an impact on quality of life, treatment adherence, and disease outcomes. The aim of this literature review was to examine studies on preferences for pharmaceutical treatment process attributes, focusing on research in diabetes, oncology, osteoporosis, and autoimmune disorders.Methods: The literature search focused on identifying studies reporting preferences for attributes of the pharmaceutical treatment process. Studies were required to use formal quantitative preference assessment methods, such as utility valuation, conjoint analysis, or contingent valuation. Searches were conducted using Medline, EMBASE, Cochrane Library, Health Economic Evaluation Database, and National Health Service Economic Evaluation Database (January 1993–October 2013).Results: A total of 42 studies met inclusion criteria: 19 diabetes, nine oncology, five osteoporosis, and nine autoimmune. Across these conditions, treatments associated with shorter treatment duration, less frequent administration, greater flexibility, and less invasive routes of administration were preferred over more burdensome or complex treatments. While efficacy and safety often had greater relative importance than treatment process, treatment process also had a quantifiable impact on preference. In some instances, particularly in diabetes and autoimmune disorders, treatment process attributes had greater relative importance than some or all efficacy and safety attributes. Some studies suggested that relative importance of treatment process depends on disease (eg, acute vs chronic) and patient (eg, injection experience) characteristics.Conclusion: Despite heterogeneity in study methods and design, some general patterns of preference clearly emerged. Overall, the results of this review suggest that treatment process has a quantifiable impact on preference and willingness to pay for treatment, even in many situations where safety and efficacy were the primary concerns. Patient preferences for treatment process attributes can inform drug development decisions to better meet the needs of patients and deliver improved outcomes. Keywords: preference, treatment process, pharmaceutical formulation, conjoint, utility, contingent valuatio