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:
Large concentrations of meperidine inhibit N-methyl-D-aspartate-(NMDA) receptor channels by channel block mechanisms. Extracellular pH regulates the activity and drug sensitivity of NMDA-receptor channels. We examined the influence of extracellular pH on sensitivity to meperidine of epsilon/zeta heteromeric NMDA-receptor channels expressed in Xenopus oocytes. Inhibition of epsilon1/zeta1, epsilon2/zeta1, epsilon3/zeta1, and epsilon4/zeta1 channels by meperidine was dependent on pH, with more inhibition at acidic pH and less inhibition at alkaline pH. The degree of voltage-dependence of meperidine block was only slightly affected by changes in pH, whereas affinity for meperidine was greatly reduced at alkaline pH. Furthermore, interaction of meperidine with Mg(2+) block was reduced at alkaline pH. Because the percentage of the protonated form of meperidine is only slightly affected by pH, changes in properties of the meperidine binding site may be involved in mechanisms of alteration of meperidine potency by pH.
answer:
Is n-methyl-D-aspartate receptor channel block by meperidine dependent on extracellular pH?


question:
Immune monitoring (IM) has not been shown to be associated with cardiac allograft vasculopathy (CAV).', 'Maximal intimal area, average percent stenosis, plaque volume, and maximal intimal thickness (MIT) were measured for matched baseline and one-yr IVUS segments in a blinded fashion. Patients were divided into quartiles by IM scores and outcomes compared. Optimal IM cutoff was determined.', 'IM assays were measured at 63.7 ± 16.4 d after transplantation in fifty patients. Progression of maximal intimal area (p = 0.005), average percent stenosis (p < 0.001), plaque volume (p = 0.005), and MIT (p = 0.001) were increased across the quartiles. An optimal IM assay cutoff of 406.0 ng ATP/mL demonstrated a sensitivity of 66.7% and specificity of 94.3% for predicting rapid progression of MIT ≥ 0.5 mm. Mean IM scores for Group 1 vs. Group 2 were 176.4 ± 102.2 and 616.3 ± 239.5 ngATP/mL, respectively. Rapid progression of MIT ≥ 0.5 mm occurred in 5/38 patients (13.2%) in Group 1 vs. 10/12 patients (83.3%) in Group 2 (p < 0.001). The risk ratio for rapid progression with elevated IM was 11.7 (p < 0.001).
answer:
Is elevated immune monitoring early after cardiac transplantation associated with increased plaque progression by intravascular ultrasound?


question:
We have previously demonstrated that sophorolipids, a class of easily chemoenzymatically modifiable glycolipids, possess anti-inflammatory effects in vitro and in vivo. Since glycolipids have been shown to have anticancer activity, we investigated the effects of sophorolipids and their derivatives against pancreatic cancer.', 'Human pancreatic carcinoma cells were treated with increasing concentrations of sophorolipid natural mixture or select derivatives (ethyl ester, methyl ester, ethyl ester monoacetate, ethyl ester diacetate, acidic sophorolipid [AS], lactonic sophorolipid diacetate [LSD]) for 24 h and assessed for cell necrosis (cytotoxicity-lactate dehydrogenase release). Controls consisted of cells treated with media or vehicle alone and sophorolipid treatment of peripheral blood mononuclear cells.', 'Sophorolipids demonstrated anticancer activity against human pancreatic carcinoma cells. Natural mixture mediated consistent cytotoxicity at all doses tested (20 +/- 4%). However, methyl ester derivative mediated much greater levels of cytotoxicity (63 +/- 5%) compared with other derivatives (ethyl ester diacetate, 36 +/- 6%, ethyl ester monoacetate, 18 +/- 7%; P < 0.05). In contrast, LSD- and AS-mediated toxicity was inversely proportional with dose (LSD, 40.3% at 0.5 mg/mL, 3.4% at 2.0 mg/mL; AS, 49% at 0.5 mg/mL, 0% at 2.0 mg/mL). Sophorolipid treatment did not affect peripheral blood mononuclear cells at all doses tested.
answer:

Are sophorolipids and their derivatives lethal against human pancreatic cancer cells?