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: We sought to assess whether mechanical unloading has beneficial effects on cardiomyocytes from doxorubicin-induced cardiomyopathy in rats.', 'Mechanical unloading by a left ventricular assist device (LVAD) improves the cardiac function of terminal heart failure in humans. However, previous animal studies have failed to demonstrate beneficial effects of mechanical unloading in the myocardium.', 'The effects of mechanical unloading by heterotopic abdominal heart transplantation were evaluated in the myocardium from doxorubicin-treated rats by analyzing the intracellular free calcium level ([Ca(2+)](i)) and the levels of intracellular Ca(2+)-regulatory proteins.', 'In doxorubicin-treated rats, the duration of cell shortening and [Ca(2+)](i) transients in cardiomyocytes was prolonged (432 +/- 28.2% of control in 50% relaxation time; 184 +/- 10.5% of control in [Ca(2+)](i) 50% decay time). Such prolonged time courses significantly recovered after mechanical unloading (114 +/- 10.4% of control in 50% relaxation time; 114 +/- 5.8% of control in 50% decay time). These effects were accompanied by an increase in sarcoplasmic reticulum Ca(2+) ATPase (SERCA2a) protein levels (0.97 +/- 0.05 in unloaded hearts vs. 0.41+/- 0.09 in non-unloaded hearts). The levels of other intracellular Ca(2+)-regulatory proteins (phospholamban and ryanodine receptor) were not altered after mechanical unloading in doxorubicin-treated hearts. These parameters in unloaded hearts without doxorubicin treatment were similar to normal hearts.\Question: Does mechanical unloading improve intracellular Ca2+ regulation in rats with doxorubicin-induced cardiomyopathy?

SOLUTION: Mechanical unloading increases functional sarcoplasmic reticulum Ca(2+) ATPase and improves [Ca(2+)](i) handling and contractility in rats with doxorubicin-induced cardiomyopathy. These beneficial effects of mechanical unloading were not observed in normal hearts.

PROBLEM: Context: Recent studies have implicated central nicotinic cholinergic receptor systems in the reinforcing properties of alcohol. In laboratory animals, mecamylamine, a central nicotinic receptor antagonist, reduces the consumption of and preference for alcohol. This study investigated the effect of mecamylamine on the subjective responses to alcohol in humans. It was hypothesized that mecamylamine (7.5 and 15 mg) would attenuate the stimulant-like subjective effects of alcohol (0.8 g/kg) and decrease the self-reported desire to consume additional alcohol beverages.', 'Fourteen male and 13 female nonsmokers participated in 6 laboratory sessions. During each session, subjects received, in randomized order under double-blinded conditions, a capsule containing mecamylamine (7.5 or 15 mg) or placebo followed by a beverage containing alcohol (0.8 g/kg) or placebo. Physiologic and subjective-effect measures were taken at 30-min intervals for 2 hr after beverage consumption.', 'Mecamylamine attenuated the stimulant and euphoric effects of alcohol and reduced the self-reported desire to consume additional alcohol beverages. This effect was most pronounced in men, even though women exhibited greater physiologic reactions to mecamylamine.\Question: Does mecamylamine attenuate the subjective stimulant-like effects of alcohol in social drinkers?

SOLUTION: These findings suggest that nicotinic cholinergic receptors are involved in mediating some of the stimulant-like effects of alcohol.

PROBLEM: Context: Recent studies evaluated the disease-modifying properties of lithium in mild cognitive impairment and dementia. Although potentially effective for these purposes, chronic lithium use in regard to safety in the elderly needs to be better explored.', 'To evaluate the effect of long-term lithium treatment at subtherapeutic doses on renal function in older adults. Secondary aims were to evaluate the clinical safety and tolerability of this treatment and its effects on thyroid, immune, and glycemic functions.', 'Between February 2007 and October 2011, a 2-year randomized, double-blind, placebo-controlled trial followed by a single-blinded phase for an additional 2 years. Sixty-one patients with mild cognitive impairment (Mayo Clinic criteria) were randomized to receive lithium or placebo. Renal function was estimated by the abbreviated Modification of Diet in Renal Disease (aMDRD) and the Chronic Kidney Disease-Epidemiology study (CKD-EPI) equations. Leukocytes, serum thyroid-stimulating hormone (TSH) and free thyroxine (T), and serum glucose and insulin were determined. Tolerability was evaluated at 3-month intervals through systematic clinical examinations and by the UKU Side Effect Rating Scale.', 'Analysis of longitudinal regression indicated that no significant changes in renal function were detected by the aMDRD (P = .453) and CKD-EPI (P = .213) equations after 4 years of lithium treatment. Significant increases in the number of neutrophils (P = .038), serum TSH (P = .034), and body weight (P = .015) were observed in the lithium group. The lithium group presented more overall adverse events (P = .045), particularly interfering in daily activities (P < .001). In addition, those patients had a higher incidence of diabetes mellitus (P = .037) and arrhythmia (P = .028).\Question: Does long-term , low-dose lithium treatment impair renal function in the elderly : a 2-year randomized , placebo-controlled trial followed by single-blind extension?

SOLUTION:
Chronic use of lithium at low doses did not affect renal function and was clinically safe. However, some other potentially relevant adverse events were observed and others could not be ruled out due to limitations of the study design.