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: Poor decision-making is a hallmark of addiction, whether to substances or activities. Performance on a widely used test of decision-making, the Iowa Gambling Task (IGT), can discriminate controls from persons with ventral medial frontal lesions, substance-dependence, and pathological gambling. Positron emission tomography (PET) studies indicate that substance-dependent individuals show altered prefrontal activity on the task. Here we adapted the IGT to an fMRI setting to test the hypothesis that defects in ventral medial and prefrontal processing are associated with impaired decisions that involve risk but may differ depending on whether substance dependence is comorbid with gambling problems.', '18 controls, 14 substance-dependent individuals (SD), and 16 SD with gambling problems (SDPG) underwent fMRI while performing a modified version of the IGT.', 'Group differences were observed in ventral medial frontal, right frontopolar, and superior frontal cortex during decision-making. Controls showed the greatest activity, followed by SDPG, followed by SD.\Question: Is prefrontal cortex activity reduced in gambling and nongambling substance users during decision-making?

SOLUTION: Our results support a hypothesis that defects in ventral medial frontal processing lead to impaired decisions that involve risk. Reductions in right prefrontal activity during decision-making appear to be modulated by the presence of gambling problems and may reflect impaired working memory, stimulus reward valuation, or cue reactivity in substance-dependent individuals.

PROBLEM: Context: Different apoptosis pathways activate caspase-3. In a study involving 27 patients with traumatic brain injury (TBI), higher caspase-3 levels were found in contusion brain tissue resected from non-survivors than from survivors. The objective of this study was to determine whether there is an association in TBI patients between serum caspase-3 levels (thus using an easier, quicker, less expensive and less invasive procedure) and mortality, in a larger series of patients.', 'We carried out a prospective, observational and multicenter study in six Spanish Hospital Intensive Care Units including 112 patients with severe TBI. All had Glasgow Coma Scale (GCS) scores lower than 9. Patients with an Injury Severity Score (ISS) in non-cranial aspects higher than 9 were excluded. Blood samples were collected on day 1 of TBI to measure serum caspas-3 levels. The endpoint was 30-day mortality.', 'We found that non-surviving patients (n = 31) showed higher (p = 0.003) serum caspase-3 levels compared to survivors (n = 81). Kaplan-Meier survival analysis showed a higher risk of death in TBI patients with serum caspase-3 levels >0.20 ng/mL than in patients with lower concentrations (Hazard Ratio = 3.15; 95% CI = 1.40 to 7.08; P < 0.001). Multiple logistic regression analysis showed that serum caspase-3 levels > 0.20 ng/mL were associated with mortality at 30 days in TBI patients controlling for Marshall CT classification, age and GCS (Odds ratio = 7.99; 95% CI = 2.116 to 36.744; P = 0.001).\Question: Are serum caspase-3 levels and mortality associated in patients with severe traumatic brain injury?

SOLUTION: The association between serum caspase-3 levels and mortality in TBI patients was the major novel finding of our study.

PROBLEM: Context: Although increased procollagen gene expression and synthesis have been implicated in the progression of abdominal aortic aneurysms (AAA), factors modulating this change have not been identified. Furthermore, it is not known whether the increase in AAA procollagen expression is specific to this disease or also occurs in tissue affected by atherosclerotic occlusive disease (AOD). If paracrine rather than autocrine factors are responsible for increased gene expression in AAA, this effect should be transferable to target smooth muscle cells through conditioned media. Our objectives were to determine 1 alpha (I) procollagen messenger RNA levels in AOD tissue compared with normal and AAA and to determine whether differences noted in tissue procollagen gene expression could be transferred through conditioned media from normal, AOD, and AAA tissues to target smooth muscle cells in primary culture.', 'Normal, AOD, and AAA tissue was used for tissue RNA extraction or was minced and washed with serum-free media (4 degrees C) x 30 minutes and the media applied to human aortic smooth muscle cells (SMC) in primary culture for 36 hours. Total RNA from tissue and SMC exposed to conditioned media was analyzed by Northern and dot blot analysis for 1 alpha (I) procollagen.', 'Relative tissue 1 alpha (I) procollagen levels were not increased in AOD (0.23 +/- 0.05) as compared with normal (0.17 +/- 0.03); both were decreased compared with AAA (0.53 +/- 0.07; p < 0.01). The 1 alpha (I) procollagen levels in SMC exposed to conditioned media from AAA (1.73 +/- 0.15) were increased (p < 0.05) compared with AOD (1.10 +/- 0.12) and normal (1.16 +/- 0.16).\Question: Do soluble factors modulate changes in collagen gene expression in abdominal aortic aneurysms?

SOLUTION:
There is no increase in tissue AOD procollagen gene expression. The ability to transfer the same relative patterns of gene expression from tissue to target SMC with conditioned media suggests that paracrine, rather than autocrine, factors modulate procollagen expression in AAA tissues.