TASK DEFINITION: In this task, you are given a passage which has a question and the context. You have to generate an answer to the question based on the information present in the context.
PROBLEM: Context: Vitamin A plays a major role in lipid metabolism. Previously, we reported that chronic vitamin A feeding (129 mg/kg) for two months normalized the abnormally high plasma HDL-cholesterol (HDL-C) levels in hypercholesterolemic obese rats by upregulating the hepatic scavenger receptor class B type 1 (SR-BI) expression. In this report, we hypothesize that the administration of a dose less than 129 mg of vitamin A/kg would also be effective in lowering the plasma HDL-C levels in these rats.', 'Changes in the activity and expression of proteins related to RCT were analyzed together with blood parameters in five-month-old male lean and obese rats supplemented with 2.6 (control group), 26, 52 and 129 mg of vitamin A/kg as retinyl palmitate for 20 weeks.', 'Vitamin A supplementation in the obese rats decreased the plasma HDL-C levels with a concomitant increase in the hepatic SR-BI expression and lipase activity compared to that observed in the control diet-fed obese rats treated with 2.6 mg of vitamin A/kg diet. Furthermore, vitamin A supplementation at doses of 52 and 129 mg/kg diet reduced the plasma lecithin cholesterol acyltransferase activity and increased the hepatic ATP-binding cassette transporter protein A1 expression in the obese rats. Interestingly, most of these changes were not observed in the lean rats fed a vitamin A-enriched diet.\Question: Does vitamin A-enriched diet modulate reverse cholesterol transport in hypercholesterolemic obese rats of the WNIN/Ob strain?

SOLUTION: Chronic feeding of a vitamin A-enriched diet in hypercholesterolemic obese rats normalizes the plasma HDL-C level and presumably improves RCT, with an effective dose of 52 mg/kg diet. Further studies should focus on the pharmacological potential of vitamin A supplementation to correct an abnormal human obesity-associated lipoprotein metabolism.

PROBLEM: Context: To introduce an elastomeric continuous infusion pump for pain control after outpatient orbital implant surgery.', 'Retrospective, noncomparative consecutive case series of all patients undergoing enucleation, evisceration, or secondary orbital implantation using the On-Q pain system between August 2004 and January 2006. Postoperative pain score, need for narcotics, and adverse events were recorded. The On-Q catheter is inserted intraoperatively through the lateral lower eyelid into the muscle cone under direct visualization, prior to the orbital implant placement. The On-Q system continually infuses anesthesia (bupivacaine) to the retrobulbar site for 5 days.', 'Among 20 patients, mean postoperative period pain score, with On-Q in place, was 1.3 (scale of 0 to 10). Nine patients (45%) did not need any adjunctive oral narcotics. Two patients experienced postoperative nausea. One catheter connector leaked, thereby decreasing delivery of retrobulbar anesthetic resulting a pain level of 6, the highest level in the study. There were no postoperative infections. No systemic toxic effects from bupivacaine were observed clinically.\Question: Do on-Q pump for pain control after orbital implant surgery?

SOLUTION: The On-Q pain pump is widely available, low cost, and requires minimal patient manipulation for the use in orbital implant surgery. The device was safe and appeared to minimize postoperative pain in the authors' case series.

PROBLEM: Context: Endothelin-1 (ET-1) is the most powerful factor known to release atrial natriuretic peptide (ANP) in vivo and in cultured cardiac myocytes or preparations of atrium. We tested the role of endogenous ET-1 in the regulation of ANP release by passive immunization in anesthetized rats.', 'Intravenous injection of antiserum against ET-1 was shown to decrease basal and volume-stimulated plasma concentrations of ANP, whereas control serum was without effect. Antiserum generated in rabbits cross-reacted 100% with endothelin-2 and -3. In pentobarbital-anesthetized Wistar rats treated with ET-1 antiserum, plasma ANP concentration measured by radioimmunoassay was reduced by 37% from starting level after 10 minutes and by 30% after 60 minutes. Control rat serum had no effect on plasma ANP. Rapid intravenous infusion of 8 mL of 0.9% NaCl caused a sixfold increase of plasma ANP concentration in control rats but only twofold in rats pretreated with ET-1 antiserum (P < .01). This effect of ET-1 antiserum was dose dependent. ET-1 antiserum changed neither blood pressure nor heart rate significantly in anesthetized rats. Pretreatment with ET-1 antiserum did not affect the initial hypotensive response to intravenous ET-1 0.5 nmol/kg but significantly attenuated the subsequent hypertensive response to endothelin.\Question: Does endothelin antiserum decrease volume-stimulated and basal plasma concentration of atrial natriuretic peptide?

SOLUTION:
Endothelin may be a physiological modulator of both basal and stimulated ANP release.