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.

[Q]: Repeated hypoglycemia is associated with hypoglycemia-associated autonomic failure (HAAF), a syndrome of defective counterregulation.', 'HAAF increases the risk of severe hypoglycemia in diabetes, although its mechanism remains unresolved. Because beta-endorphin influences the autonomic response to hypoglycemia via opioid receptor activation, we hypothesized that it is also involved in the pathogenesis of HAAF.', 'We asked whether opioid receptor blockade during antecedent hypoglycemia (60 mg/dl) on d 1 would prevent development of HAAF on d 2 in eight nondiabetic subjects (five males, 3 females; age, 28 +/- 3.5 yr; body mass index, 24.2 +/- 2.1 kg/m(2)). On four occasions, d 1 was: 1) two 90-min hypoglycemic clamps (N-); 2) two 90-min hypoglycemic clamps plus naloxone (N+); 3) two euglycemic 90-min clamps (C); or 4) two euglycemic 90-min clamps plus naloxone (C+).', 'Day 1 hypoglycemia caused marked deterioration of d 2 hormonal responses to hypoglycemia, consistent with HAAF-i.e. decreased plasma epinephrine, norepinephrine, and glucagon compared to control (C) (374 +/- 71 vs. 810 +/- 94, 307 +/- 65 vs. 686 +/- 98, and 71 +/- 9 vs. 93 +/- 4 pg/ml, respectively, P < 0.01), as well as in endogenous glucose production (24 vs. 163%; P < 0.01). In contrast, naloxone on d 1 completely prevented the defective counterregulatory responses; epinephrine, norepinephrine, and glucagon (852 +/- 82, 769 +/- 77, and 98 +/- 7 pg/ml) and endogenous glucose production recovery (167%) were identical to those after d 1 euglycemia (P < NS for all). Infusion of naloxone alone during euglycemia on d 1 (C+) had no effect on d 2 responses.
[A]: Is hypoglycemia-associated autonomic failure prevented by opioid receptor blockade?


[Q]: Changes of volume status can be readily inferred from variations in diameter of the inferior vena cava (IVC) measured by ultrasound. However the effect of IVC changes following acute blood loss are not fully established. In this study, three different approaches to measuring IVC variables were compared in healthy blood donors, as a model of acute volume depletion, in order to establish their relative ability to detect acute blood loss.', 'Inspiratory and expiratory IVC diameters were measured before and after blood donation in hepatic long axis, hepatic short axis and renal short axis views using a 2-5\xa0MHz curvilinear probe. All measurements were recorded and examined in real-time and post-processing sessions.', 'All windows performed satisfactorily but the renal window approach was feasible in only 30 out of 47 subjects. After blood donation, IVC diameters decreased in hepatic long axis, hepatic short axis and renal short axis (expiratory: -19.9, -18.0, -26.5\xa0%; CI 95\xa0%: 14.5-24.1; 13.1-22.9; 16.0-35.9, respectively) (inspiratory: -31.1, -31.6, -36.5\xa0%; CI 95\xa0%: 21.3-40.1; 18.8-45.2; 23.4-46.0, respectively), whereas the IVC collapsibility index increased by 21.6, 22.6 and 19.3\xa0% (CI 95\xa0%: 11.6-42.9; 18.5-39.5; 7.7-30.0). IVC diameters appeared to return to pre-donation values within 20\xa0min but this was only detected by the hepatic long axis view.
[A]: Do inferior vena cava diameters and collapsibility index reveal early volume depletion in a blood donor model?


[Q]: To verify an impact of a lymph node revealing solution (LRS) on the number of lymph nodes (LN) revealed in colorectal resection specimens.', "Fifty-nine cases of rectosigmoid carcinomas divided into two subgroups-stage pT2&3 (20 cases) and ypT2&3 (with pre-operative radiotherapy-39 cases)-were formalin fixed for 42-72 h, serially sectioned and re-fixed in LRS containing ethanol, diethyl ether, glacial acetic acid, and formalin for 24 h. The number of LNs was matched to a control group consisting of 34 cases of colorectal carcinoma, 14 pT2&3 and 20 ypT2&3 rectosigmoid carcinomas examined routinely. Results were statistically tested by Student's t-test.", 'In the study group the total number of revealed LNs was 869, range 1-48, average 14.7 per specimen, median 15. In the control group the number of LNs was 200, range 0-13, average 5.9 per specimen, median 6. The difference between the study and the control group was statistically significant (P = 0.05).
[A]:
Is re-fixation in a lymph node revealing solution a powerful method for identifying lymph nodes in colorectal resection specimens?