Given a passage with a context and an answer, construct a question on the basis of the information present in the passage. Construct the question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) it answer uses text phrases from the passage. Avoid creating questions that (i) can't be answered correctly without actually understanding the passage and (ii) uses the same words or phrases given in the passage.

Context: Normal glucose metabolism depends on pancreatic secretion of insulin and glucagon. The bihormonal hypothesis states that while lack of insulin leads to glucose underutilisation, glucagon excess is the principal factor in diabetic glucose overproduction. A recent study reported that streptozotocin-treated glucagon receptor knockout mice have normal glucose tolerance. We investigated the impact of acute disruption of glucagon secretin or action in a mouse model of severe diabetes by three different approaches: (1) alpha cell elimination; (2) glucagon immunoneutralisation; and (3) glucagon receptor antagonism, in order to evaluate the effect of these on glucose tolerance.', 'Severe diabetes was induced in transgenic and wild-type mice by streptozotocin. Glucose metabolism was investigated using OGTT in transgenic mice with the human diphtheria toxin receptor expressed in proglucagon producing cells allowing for diphtheria toxin (DT)-induced alpha cell ablation and in mice treated with either a specific high affinity glucagon antibody or a specific glucagon receptor antagonist.', 'Near-total alpha cell elimination was induced in transgenic mice upon DT administration and resulted in a massive decrease in pancreatic glucagon content. Oral glucose tolerance in diabetic mice was neither affected by glucagon immunoneutralisation, glucagon receptor antagonism, nor alpha cell removal, but did not deteriorate further compared with mice with intact alpha cell mass.
Answer: Disruption of glucagon action/secretion did not improve glucose tolerance in diabetic mice. Near-total alpha cell elimination may have prevented further deterioration. Our findings support insulin lack as the major factor underlying hyperglycaemia in beta cell-deficient diabetes.
Does acute disruption of glucagon secretion or action improve glucose tolerance in an insulin-deficient mouse model of diabetes?

Context: Progenitor cells isolated from cardiac explant-derived cells improve cardiac function after myocardial infarction (MI). To fully realize the therapeutic potential of these cells, it is essential to develop a safe and efficient delivery method. Therefore, the objective of this study was to determine the efficacy of our newly developed approach to retrograde coronary vein (RCV) infusion of cardiac c-Kit(+) cells in a small-animal model of congestive heart failure (CHF).', 'Sprague-Dawley rats underwent experimental MI. After 21 days, cardiac explant-derived c-Kit(+) cells were delivered to both sham and CHF animals using RCV delivery. Vehicle-treated (serum-free medium) sham and CHF animals were used as controls. Cardiac function and heart tissues were evaluated 21 days post-transplantation.', 'RCV-delivered cells were retained in infarcted hearts for at least 21 days after transplantation. At 21 days post-RCV infusion, the majority of transplanted c-Kit(+)/GFP(+) cells were localized in the left ventricle. Compared with vehicle-treated CHF animals, RCV-treated rats showed a significant improvement in cardiac function. Furthermore, RCV-treated rats exhibited an increase in capillary density, a decrease in total heart collagen, and a reduction in both infarct size and cardiomyocyte hypertrophy when compared with vehicle-treated CHF rats.
Answer: Our study showed that the RCV infusion approach is an efficient technique for targeted cell delivery to the infarcted myocardium. Cardiac c-Kit(+) cells, delivered using RCV infusion ameliorated progression of heart failure, improved cardiac function and retarded myocardial remodeling in heart failure rats.
Does retrograde coronary vein infusion of cardiac explant-derived c-Kit+ cells improves function in ischemic heart failure?

Context: Sleep disturbance is the primary clinical morbidity of restless legs syndrome (RLS). To date, sleep disturbance in RLS has been measured in (1) clinical samples with polysomnography (PSG) or (2) population-based samples by self-report. The objective of this study was to analyze sleep by PSG in a population-based sample with symptoms of RLS.', 'Cross-sectional observational study.', 'Community-based.', '3433 older men and women.', 'None.', 'RLS was evaluated using an 8-item self-administered questionnaire based on NIH diagnostic criteria and required symptoms occurring > or = five times per month and associated with at least moderate distress. Health-related quality of life (HRQOL) was determined using the SF-36. Unattended, in-home PSG was performed. Data were assessed using general linear models with adjustment for demographic, health-related variables, and apnea-hypopnea index (AHI). Subjects with RLS had longer adjusted mean sleep latency (39.8 vs 26.4 min, P < 0.0001) and higher arousal index (20.1 vs 18.0, P = 0.0145) than those without RLS. Sleep latency increased progressively as the frequency of RLS symptoms increased from 5-15 days per month to 6-7 days per week. No differences in sleep stage percentages were observed between participants with and without RLS. Subjects with RLS also reported poorer HRQOL in all physical domains as well as in the Mental Health and Vitality domains.
Answer: These novel PSG data from a nonclinical, community-based sample of individuals with RLS document sleep disturbance in the home even in individuals with intermittent symptoms.
Does polysomnographic and health-related quality of life correlate of restless legs syndrome in the Sleep Heart Health Study?