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 condition at operation determined by the physiologic POSSUM score is related to postoperative mortality and morbidity of colorectal cancer surgery. This study was designed to analyze the relationship between condition of patients with colorectal cancer at operation and long-term overall survival.', 'A total of 542 patients survived a radical resection for Stages I, II, or III colorectal cancer. Physiologic POSSUM score at surgery, exclusive of age, was calculated for all patients. Mean physiologic POSSUM score was used as cutoff point to determine low-risk and high-risk group patients. A Cox proportional hazard analysis was performed to study the effect of low-risk and high-risk group on overall survival and to identify independent risk factors.', 'Five-year overall survival was significantly higher in low-risk group patients than in high-risk group patients (low-risk group 66.6 percent vs. high-risk group 48.5 percent; P < 0.001). Differences in overall survival also were found when patients in Stages I, II, and III were analyzed separately. Risk factors for overall survival were advanced stage of disease, poor tumor differentiation, mucinous adenocarcinoma, older than age 70 years, and poor condition of the patient at time of operation.\Question: Does pOSSUM predict decreased overall survival in curative resection for colorectal cancer?

SOLUTION: Poor condition at operation, as determined by physiologic POSSUM score, is a risk indicator for long-term overall survival in colorectal cancer patients.

PROBLEM: Context: Familial hypercholesterolemia (FH) is a genetic disorder characterized by elevated levels of total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C). Guidelines recommend cholesterol-lowering medication from 8 to 10 years of age and dietary recommendations. Little is known about the diet of FH children and the effect of dietary counseling. The aim of the study was to describe the diet of FH children with respect to fat quality, and to investigate if dietary counseling improved lipid profile.', 'Fifty-four FH children (5-18 years) were included in the study and dietary intake was recorded with a pre-coded food diary for four days. Information about plasma lipid levels was obtained.', 'Median intake of total fat, monounsaturated fat, polyunsaturated fat (PUFA) and saturated fat (SFA) was 30.8, 10.4, 5.9 and 12.0\xa0E %, respectively. Among non-statin treated FH children, SFA intake was significantly correlated with TC, LDL-C and apolipoprotein (apo) B (rsp\xa0=\xa00.55; p\xa0=\xa00.004, rsp\xa0=\xa00.46; p\xa0=\xa00.02, and rsp\xa0=\xa00.45; p\xa0=\xa00.02, respectively), and PUFA/SFA ratio significantly inversely correlated with TC (rsp\xa0=\xa0-0.42; p\xa0=\xa00.03). Compared to the first visit, non-statin and non-plant sterol treated FH children (n\xa0=\xa010) had significantly reduced levels of TC (p\xa0<\xa00.01), LDL-C (p\xa0=\xa00.01), high-density lipoprotein cholesterol (p\xa0=\xa00.02), apo B (p\xa0=\xa00.05) and apo A-1 (p\xa0=\xa00.02) levels at a later visit.\Question: Is dietary counseling associated with an improved lipid profile in children with familial hypercholesterolemia?

SOLUTION: FH children had a higher intake of SFA than recommended and the SFA intake was positively correlated with plasma TC, LDL-C and apo B levels in FH children not using statins. Importantly, the plasma lipid profile was improved in FH children after dietary counseling where focus was on reducing intake of SFA and dietary cholesterol.

PROBLEM: Context: Reactive oxygen species (ROS) are involved in a wide range of cellular processes. However, few studies have examined the generation and function of ROS in human embryonic vascular development. In this study, the sources of ROS and their roles in the vascular differentiation of human embryonic stem cells (hESCs) were investigated.', 'During vascular differentiation of hESCs, CD34(+) cells had quiescence-related gene expression profiles and a large fraction of these cells were in G0 phase. In addition, levels of ROS, which were primarily generated through NOX4, were substantially higher in hESC-derived CD34(+) cells than in hESC-derived CD34(-) cells. To determine whether excess levels of ROS induce quiescence of hESC-derived CD34(+) cells, ROS levels were moderately reduced using selenium to enhance antioxidant activities of thioredoxin reductase and glutathione peroxidase. In comparison to untreated CD34(+) cells, selenium-treated CD34(+) cells exhibited changes in gene expression that favoured cell cycle progression, and had a greater proliferation and a smaller fraction of cells in G0 phase. Thus, selenium treatment increased the number of hESC-derived CD34(+) cells, thereby enhancing the efficiency with which hESCs differentiated into vascular endothelial and smooth muscle cells.\Question: Do reactive oxygen species regulate the quiescence of CD34-positive cells derived from human embryonic stem cells?

SOLUTION:
This study reveals that NOX4 produces ROS in CD34(+) cells during vascular differentiation of hESCs, and shows that modulation of ROS levels using antioxidants such as selenium may be a novel approach to increase the vascular differentiation efficiency of hESCs.