TASK DEFINITION: In this task, you are given a passage which has a question and the context. You have to generate an answer to the question based on the information present in the context.
PROBLEM: Context: To study the pathophysiological importance of changes in insulin sensitivity and islet function over time for alterations in glucose tolerance in a randomly selected large group of non-diabetic women aged 57-59 years over a 3-year period.', 'At baseline and at the 3-year follow-up, glucose tolerance (WHO 75 g oral glucose), insulin sensitivity (euglycaemic, hyperinsulinaemic clamp) and insulin and glucagon secretion (2 to 5-min responses to 5 g i.v. arginine at fasting, 14 and > 25 mmol/l glucose) were measured.', 'At baseline, women with impaired glucose tolerance (IGT, n = 28) had lower insulin sensitivity (p = 0.048) than normal women (NGT, n = 58). The arginine-induced insulin responses (AIR) were inversely associated with insulin sensitivity (r > or = -0.55, p < 0.001). When related to the 3-year follow-up, the baseline product of AIR at 14 mmol/l glucose times insulin sensitivity, insulin effect index (IE) (r = -0.40, p < 0.001) and the arginine-induced glucagon response at 14 mmol/l glucose (AGR, r = 0.28, p = 0.009) both correlated with follow-up 2-h glucose. In a multiple regression model, baseline 2-h glucose, insulin effect index and arginine-induced glucagon response independently predicted 2-h glucose at follow-up (total r = 0.668, p < 0.001). Furthermore, delta insulin sensitivity (i. e. follow-up minus baseline) correlated with delta insulin secretion (r = -0.30, p = 0.006), whereas delta glucagon secretion correlated with delta2-h glucose (r = 0.30, p = 0.006) over the 3 years. In a multiple regression, alterations in 2-h glucose over the 3 years were independently determined by changes in fasting insulin and glucagon secretion (r = 0.424, p < 0.001).\Question: Is glucose intolerance predicted by low insulin secretion and high glucagon secretion : outcome of a prospective study in postmenopausal Caucasian women?

SOLUTION: Low insulin secretion, when judged in relation to insulin sensitivity, and high glucagon secretion, determine glucose tolerance over time in the individual subject. These processes are therefore potential targets for prevention of deterioration in glucose tolerance.

PROBLEM: Context: Several Northern Hemisphere Drosera species have been used in the therapy of respiratory tract infections as the traditional medicine Droserae Herba.', 'To determine the anti-inflammatory effects of Drosera species and to investigate a substitute material for Droserae Herba, we examined the effect of extracts of Drosera rotundifolia, Drosera tokaiensis and Drosera spatulata on activated T cell membrane (aTc-m)-induced inflammatory gene expression in HMC-1 human mast cells.', 'Drosera rotundifolia, Drosera spatulata and Drosera tokaiensis were collected in Japan. Herbs were extracted with 80% EtOH, and subsequently applied to OASIS HLB column. HMC-1 cells were treated with each Drosera column-adsorbed fraction for 15min, and subsequently added to aTc-m and incubated for 16h. Inflammatory gene and protein expressions were determined by DNA microarray, RT-PCR and Western blotting.', 'Drosera rotundifolia and Drosera tokaiensis fractions, but not the Drosera spatulata fraction, suppressed inflammatory gene expression induced by aTc-m in HMC-1 cells.\Question: Do drosera rotundifolia and Drosera tokaiensis suppress the activation of HMC-1 human mast cells?

SOLUTION: Drosera rotundifolia and Drosera tokaiensis suppressed activation of HMC-1 cells induced by aTc-m. Since the Drosera tokaiensis fraction was more effective than the traditionally used Drosera rotundifolia, Drosera tokaiensis is a likely substitute as a source of Droserae Herba.

PROBLEM: Context: Interaction of macrophages with aggregated matrix-anchored lipoprotein deposits is an important initial step in atherogenesis. Aggregated lipoproteins require different cellular uptake processes than those used for endocytosis of monomeric lipoproteins. In this study, we tested the hypothesis that engagement of aggregated LDL (agLDL) by macrophages could lead to local increases in free cholesterol levels and that these increases in free cholesterol regulate signals that control cellular actin.', 'AgLDL resides for prolonged periods in surface-connected compartments. Although agLDL is still extracellular, we demonstrate that an increase in free cholesterol occurs at sites of contact between agLDL and cells because of hydrolysis of agLDL-derived cholesteryl ester. This increase in free cholesterol causes enhanced actin polymerization around the agLDL. Inhibition of cholesteryl ester hydrolysis results in decreased actin polymerization.\Question: Does aggregated LDL in contact with macrophages induce local increases in free cholesterol levels that regulate local actin polymerization?

SOLUTION:
We describe a novel process that occurs during agLDL-macrophage interactions in which local release of free cholesterol causes local actin polymerization, promoting a pathological positive feedback loop for increased catabolism of agLDL and eventual foam cell formation.