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.

Input: Consider Input: Context: Current staging for renal cancer (RC) does not directly rely on tumor size. We examined the increment in accuracy related to inclusion of pathologically determined tumor size in prediction of nodal metastases (N+), distant metastases (M+), and cancer-specific survival (CSS).', 'Partial or radical nephrectomy was performed in 2245 patients with clear cell histology. Pathologic stages were T1a in 566, T1b in 490, T2 in 303, T3 in 831, and T4 in 55 patients. Tumor size was 0.5-25 cm (mean, 6.8). Multivariate models relied on 1997 and 2002 TNM variables and addressed N+, M+ disease, and CCS. Their accuracy was compared according to either the presence or absence of tumor size.', 'In all univariate and multivariate models, tumor size was a statistically significant predictor of all outcomes (p< or =0.001). In all multivariate models, tumor size added between 3.7% and 0.8% to predictive accuracy of either 1997 or 2002 TNM categories.
Answer: Tumor size represents a highly significant, multivariate, and informative predictor of RC outcomes and may warrant inclusion in future TNM revisions.

Output: Does tumor size improve the accuracy of TNM predictions in patients with renal cancer?


Input: Consider Input: Context: Downstream effects of muscarinic receptor stimulation in intestinal smooth muscle include contraction and intestinal transit. We thought to determine whether classic transient receptor potential (TRPC) channels integrate the intracellular signaling cascades evoked by the stimulated receptors and thereby contribute to the control of the membrane potential, Ca-influx, and cell responses.', 'We created trpc4-, trpc6-, and trpc4/trpc6-gene-deficient mice and analyzed them for intestinal smooth muscle function in vitro and in vivo.', 'In intestinal smooth muscle cells TRPC4 forms a 55 pS cation channel and underlies more than 80% of the muscarinic receptor-induced cation current (mI(CAT)). The residual mI(CAT) depends on the expression of TRPC6, indicating that TRPC6 and TRPC4 determine mI(CAT) channel activity independent of other channel subunits. In TRPC4-deficient ileal myocytes the carbachol-induced membrane depolarizations are diminished greatly and the atropine-sensitive contraction elicited by acetylcholine release from excitatory motor neurons is reduced greatly. Additional deletion of TRPC6 aggravates these effects. Intestinal transit is slowed down in mice lacking TRPC4 and TRPC6.
Answer: In intestinal smooth muscle cells TRPC4 and TRPC6 channels are gated by muscarinic receptors and are responsible for mI(CAT). They couple muscarinic receptors to depolarization of intestinal smooth muscle cells and voltage-activated Ca(2+)-influx and contraction, and thereby accelerate small intestinal motility in vivo.

Output: Does deletion of TRPC4 and TRPC6 in mice impair smooth muscle contraction and intestinal motility in vivo?


Input: Consider Input: Context: To perform a health maintenance organization-based case-control study to evaluate the association of total and high density lipoprotein (HDL) cholesterol with the risk of stroke subtypes and in patient subgroups.', 'Cases had a confirmed incident ischemic stroke (n = 1,242) or hemorrhagic stroke (n = 313). Controls (n = 6,455) were identified in a companion myocardial infarction study. Risk of stroke was modeled using logistic regression.', 'The highest total cholesterol quintile was associated with an increased risk of ischemic stroke compared to the lowest quintile (OR = 1.6, 95% CI 1.3 to 2.0) with the strongest subtype associations for atherosclerotic stroke (OR = 3.2) and lacunar stroke (OR = 2.4). The highest HDL cholesterol quintile was associated with a decreased risk of ischemic stroke compared to the lowest quintile (OR = 0.8, CI 0.6 to 1.0). Subgroup analyses suggested that the total cholesterol association was more important for patients < 66 years of age and those with HDL < 50 mg/dL; the HDL association was more important for patients without diabetes or atrial fibrillation. The second through fourth total cholesterol quintiles were associated with a decreased risk of hemorrhagic stroke compared to the lowest quintile (OR = 0.7, CI 0.5 to 1.0).
Answer: Higher total and lower HDL cholesterol levels were associated with increased risk of ischemic stroke, especially certain stroke subtypes and patient subgroups. The lowest levels of total cholesterol were associated with an increased risk of all hemorrhagic strokes.


Output: Does association of cholesterol with stroke risk vary in stroke subtypes and patient subgroups?