TASK DEFINITION: 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.
PROBLEM: Context: Before desflurane is advocated for patients undergoing neurosurgical procedures, it is necessary to determine the effect of desflurane on cerebral blood flow (CBF). In this study, CBF values are compared between desflurane and isoflurane at two doses. In addition, CBF reactivity to CO2 and the effect of prolonged exposure were compared between the two agents.', 'Cerebral blood flow measurements with intravenous 133Xe were performed in 24 patients undergoing craniotomy for mass lesions, randomized to receive either isoflurane or desflurane in oxygen and air. Cerebral blood flow was determined at 1 and 1.5 MAC concentrations at PaCO2 of 25 mmHg in the absence of surgical stimulation. Intraoperatively, with 1.25 MAC anesthesia, CBF was determined at target PaCO2 of 25 and 35 mmHg. In 15 patients, an additional measurement at 1.25 MAC was made before closure.', 'At 1.0 MAC, mean +/- SD CBF values for the desflurane and isoflurane groups were 18 +/- 2 and 20 +/- 3 ml x 100 g-1 x min-1, respectively. At 1.5 MAC, CBF values were the same for the two anesthetics; 17 +/- 3 ml x 100 g-1 x min-1 for isoflurane and 19 +/- 4 ml.100 g-1 x min-1 for desflurane. During 1.25 MAC anesthesia, there were no differences between groups, with CO2 reactivity 1.3 +/- 1.2 ml x 100 g-1 x min-1 x mmHg-1 for desflurane and 1.6 +/- 0.6 ml.100 g-1 x min-1 x mmHg-1 for isoflurane. There was no demonstrable decrease in CBF with prolonged exposure to either agent.
Answer: Desflurane and isoflurane are similar in terms of absolute CBF, the response to increasing doses, and the preservation of CO2 reactivity.

SOLUTION: Do desflurane and isoflurane have similar effects on cerebral blood flow in patients with intracranial mass lesions?

PROBLEM: Context: To investigate the expression and clinical significance of programmed cell death 4 (PDCD4), a novel metabolism-associated gene, during polycystic ovary syndrome (PCOS) pathogenesis.', 'Case-control study.', 'University hospital.', 'A total of 77 PCOS patients and 67 healthy women as matched controls.', 'PDCD4 expression in peripheral blood mononuclear cells analyzed by quantitative real-time polymerase chain reaction, and apoptosis of granulosa cells (GCs) detected by flow cytometry, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL), and small-interfering RNA.', 'PDCD4 expression, body mass index (BMI), insulin 0, insulin 120, glucose 120, homeostasis model assessment for insulin resistance (HOMA-IR), homeostasis model assessment for β-cell function (HOMA-β), triglycerides, high-density lipoprotein (HDL), and GC apoptosis.', 'The PCOS patients had higher PDCD4 expression, but BMI was similar as matched with the obese group, which positively correlated with BMI, insulin 0, insulin 120, glucose 120, HOMA-IR, HOMA-β, triglycerides and negatively correlated with HDL (P<.05). After metformin treatment, PDCD4 expression was distinctly down-regulated for the obese women with PCOS with insulin resistance. Compared with the healthy controls, the apoptosis percentage of GCs was higher in the PCOS group and was decreased by knocking down PDCD4. Furthermore, expression of proapotosis factor Bax and the Bax/Bcl-2 ratio were lower, whereas the expression of antiapoptosis factor Bcl-2 was increased. In a multivariate logistic regression analysis, the level of PDCD4 expression independently related to the odds of PCOS risk after controlling for estradiol and insulin 120 (odds ratio 1.318).
Answer: Our study suggests for the first time that higher PDCD4 expression might play an important role in PCOS pathogenesis by affecting obesity, insulin resistance, lipid metabolism disorders, and GC apoptosis.

SOLUTION: Is higher PDCD4 expression associated with obesity , insulin resistance , lipid metabolism disorders , and granulosa cell apoptosis in polycystic ovary syndrome?

PROBLEM: Context: We have previously shown that phospholipid oxidation products of 1-palmitoyl-2-arachidonoyl-sn-glycero-3-phosphorylcholine (ox-PAPC) inhibit lipopolysaccharide (LPS)-induced E-selectin expression and neutrophil binding in human aortic endothelial cells (HAECs). The current studies identify specific phospholipids that inhibit chemokine induction by Toll-like receptor-4 (TLR4) and -2 (TLR2) ligands inECs and macrophages.', 'Measurements of interleukin (IL)-8 and monocyte chemotactic protein-1 levels secreted from ox-PAPC- and LPS-cotreated ECs indicate that ox-PAPC inhibits activation of TLR4 by LPS. The effects of IL-1beta and tumor necrosis factor-alpha, which utilize the same intracellular signaling molecules, were not inhibited. Cell fractionation and immunofluorescence analyses demonstrate that LPS induces membrane translocation of the LPS receptor complex to a lipid raft/caveolar fraction in ECs. Ox-PAPC inhibits this translocation and alters caveolin-1 distribution. Supporting an important role for caveolae in LPS action, overexpression of caveolin-1 enhanced LPS-induced IL-8 synthesis. Ox-PAPC also inhibits the effect of TLR2 and TLR4 ligands in human macrophages.
Answer: These studies report a novel mechanism that involves alterations to lipid raft/caveolar processing, by which specific phospholipid oxidation products inhibit activation by TLR4 and TLR2 ligands. These studies have broader implications for the role of ox-PAPC as a regulator of specific lipid raft/caveolar function.

SOLUTION:
Do specific phospholipid oxidation products inhibit ligand activation of toll-like receptors 4 and 2?