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: Isotretinoin is effective in the treatment of severe acne and rosacea. Both parent drug and its main metabolite 4-oxo-isotretinoin are potentially teratogenic compounds and contain a carboxylic acid moiety. In the presence of ethanol, naturally occurring as well as synthetic retinoids also containing a carboxylic acid moiety are capable of undergoing an ethyl esterification with the metabolic formation of more lipophilic compounds with a much longer terminal half-life.', 'To determine if isotretinoin (13-cis-RA), its main metabolite 4-oxo-isotretinoin (4-oxo-13-cis-RA), and other possible metabolites in the presence or absence of ethanol are converted to their corresponding ethyl derivatives in patients with severe acne or rosacea after multiple isotretinoin dosing. In addition, pharmacokinetic parameters of the parent drug and its 4-oxo metabolite were determined.', 'Eleven patients with severe acne or rosacea were treated with isotretinoin daily for 3 months and investigated pharmacokinetically during 24 h after 1 month of treatment and for up to 28 days after discontinuation of therapy. A possible influence of ethanol was evaluated using a simple self-administered questionnaire and by measuring serum ethanol levels during treatment. The concentrations of isotretinoin, 4-oxo-isotretinoin and possible ethylated and nonethylated metabolites were measured by reverse-phase high-performance liquid chromatography.', "Although seven of 11 patients had a considerable weekly alcohol intake, no endogenous synthesis of ethyl derivatives of isotretinoin, the main 4-oxo metabolite or the all-trans compounds was chromatographically detectable in any of the patients' plasma samples during the treatment period. Multiple dose pharmacokinetic data for the parent drug and its main metabolite were comparable to previous studies.
Answer: The metabolism and pharmacokinetics of isotretinoin and its main metabolites are not influenced by ethanol during long-term isotretinoin treatment. After ceasing long-term isotretinoin therapy the recommended period of 1 month for using anticonceptive measures in fertile women seems adequate.

SOLUTION: Are the metabolism and pharmacokinetics of isotretinoin in patients with acne and rosacea influenced by ethanol?

PROBLEM: Context: The shape of the ionizing radiation response curve at very low doses has been the subject of considerable debate. Linear-no-threshold (LNT) models are widely used to estimate risks associated with low-dose exposures. However, the low-dose hyperradiosensitivity (HRS) phenomenon, in which cells are especially sensitive at low doses but then show increased radioresistance at higher doses, provides evidence of nonlinearity in the low-dose region. HRS is more prominent in the G2 phase of the cell cycle than in the G0/G1 or S phases. Here we provide the first cytogenetic mechanistic evidence of low-dose HRS in human peripheral blood lymphocytes using structural chromosomal aberrations.', 'Human peripheral blood lymphocytes from 2 normal healthy female donors were acutely exposed to cobalt 60 γ rays in either G0 or G2 using closely spaced doses ranging from 0 to 1.5 Gy. Structural chromosomal aberrations were enumerated, and the slopes of the regression lines at low doses (0-0.4 Gy) were compared with doses of 0.5 Gy and above.', 'HRS was clearly evident in both donors for cells irradiated in G2. No HRS was observed in cells irradiated in G0. The radiation effect per unit dose was 2.5- to 3.5-fold higher for doses ≤0.4 Gy than for doses >0.5 Gy.
Answer: These data provide the first cytogenetic evidence for the existence of HRS in human cells irradiated in G2 and suggest that LNT models may not always be optimal for making radiation risk assessments at low doses.

SOLUTION: Is cytogenetic low-dose hyperradiosensitivity observed in human peripheral blood lymphocytes?

PROBLEM: Context: Chronic cytomegalovirus (CMV) infection has been associated with immunosenescence and immunoactivation in the general population. In human immunodeficiency virus type 1 (HIV-1)-infected people, CMV coinfection, in addition to residual HIV replication and microbial translocation, has been proposed as a key factor in sustaining immune activation, even in individuals with a controlled HIV load.', 'Patients from the ICONA Study with at least 1 CMV immunoglobulin G (IgG) test available without active CMV disease were included in the analysis. AIDS-defining event or AIDS-related death and severe non-AIDS-defining event or non-AIDS-related death were taken as clinical progression end points. Independent predictors of CMV were identified by multivariable logistic regression. Probabilities of reaching the end points were estimated by survival analyses.', 'A total of 6111 subjects were included, of whom 5119 (83.3%) were CMV IgG positive at baseline. Patients with CMV IgG positivity at baseline were more likely to develop a severe non-AIDS-defining event/non-AIDS-related death (adjusted hazard ratio [HR], 1.53 [95% confidence interval {CI}, 1.08-2.16]. In particular, CMV seropositivity was an independent risk factor for cardiovascular and cerebrovascular diseases (adjusted HR, 2.27 [95% CI, .97-5.32]).
Answer: In our study population, CMV/HIV coinfection was associated with the risk of severe non-AIDS-defining events/non-AIDS-related death, especially with cardiovascular and cerebrovascular events, independently of other prognostic factors. This finding supports a potential independent role of CMV coinfection in vascular/degenerative organ disorders in HIV-infected subjects.

SOLUTION:
Is cytomegalovirus coinfection associated with an increased risk of severe non-AIDS-defining events in a large cohort of HIV-infected patients?