instruction:
Given a passage, 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.
question:
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:
Does acute disruption of glucagon secretion or action improve glucose tolerance in an insulin-deficient mouse model of diabetes?

question:
Visceral obesity is shown to be a predictor of morbidity and mortality. We evaluated the association of measurements of generalized adiposity and visceral fat area (VFA), with abnormalities of metabolic syndrome (MS).', 'Seventy-six women (47.9 +/- 9.2 years) with BMI of 38.7 +/- 5.4 kg/m(2) underwent anthropometric measurements, laboratory procedures, bioeletrical impedance, and abdominal computed tomography (CT) scan. Diagnosis of MS was based on the presence of abdominal obesity and at least two of the following components: hypertension, dyslipidemia, and glucose intolerance and/or hyperinsulinemia.', 'BMI was correlated with both components of adipose tissue--subcutaneous (r = 0.66, P < 0.01) and VFA (r = 0.33, P < 0.02)--and leptin levels (r = 0.38, P < 0.01). In contrast, VFA was correlated with 2-h glucose and insulin levels (r = 0.32 and 0.35, P < 0.05, respectively), triglyceride, HDL cholesterol, and uric acid (r = 0.33, -0.34 and 0.24, P < 0.05, respectively). Subjects with high VFA, matched for BMI, showed greater plasma glucose area under the curve (621 +/- 127 vs. 558 +/- 129 mg x h(-1) x dl(-1), P < 0.05), 2-h insulin (804 +/- 599 vs. 579 +/- 347 pmol/l, P < 0.05), and uric acid levels (0.33 +/- 0.07 vs. 0.26 +/- 0.06 mmol/l, P < 0.05) than subjects with low VFA. In logistic regression analysis, waist circumference, VFA, and 2-h insulin were identified as independent predictors of MS. Receiver operating characteristic curve analysis pointed out the values of 104 cm for waist circumference (58.1% specificity, 84.1% sensitivity), 158.5 cm(2) for VFA (78.1% specificity, 52.3% sensitivity), and 559.8 pmol/l for 2-h insulin (71.9% specificity, 69.8% sensitivity); the presence of at least two of the three variables resulted in a degree of concordance of 76%.
answer:
Does two-hour insulin determination improve the ability of abdominal fat measurement to identify risk for the metabolic syndrome?

question:
To determine whether repeat administration of an adenovector (Ad) into the eye results in efficient gene delivery and to test whether transgenes can be expressed from an adenovector expression system in the presence of preexisting, neutralizing anti-Ad antibodies.', 'To assess the efficiency of repeated gene delivery of an adenovector expression system, C57Bl/6 mice received one, two, or three injections (intravitreal [IVT] or periocular [PO]) of AdNull.11D (empty cassette) at 2-week intervals, followed by a single AdLuciferase (AdL.11D) IVT or PO injection. Mice were killed approximately 24 hours after AdL.11D injection and the eyes were enucleated and stored until assayed. Serum samples were also analyzed to determine whether repeated IVT or PO injections lead to induction of neutralizing antibodies directed against an adenovector delivery system. To determine whether preexisting neutralizing anti-Ad antibodies would block transgene expression, mice were preimmunized with one, two, or three intramuscular (IM) injection(s) of AdNull.11D (1 x 10(9) particle units [pu]). Fourteen days later, when systemic anti-Ad antibody titers were expected to exist, mice were given a single AdL.11D injection (IVT or PO) and killed, and the eyes and serum collected.', 'These studies show that multiple injections at 2-week intervals with adenovectors (IM, IVT, or PO) did not prevent transgene expression in the eye. Moreover, measurement of neutralizing anti-Ad antibody titers revealed that measurable anti-Ad antibody titers in mice did not ablate transgene expression.
answer:
Does repeated administration of adenovector in the eye result in efficient gene delivery?