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: In this study, we compared the diagnostic performance of the standard SPECT with motion-frozen (MF) myocardial perfusion SPECT (MPS) in obese patients.', 'A total of 90 consecutive obese patients (body mass index, 30.1-46.8, average, 34.3 +/- 3.6; age, 63 +/- 12 y; 30% women) underwent standard supine rest (201)Tl/stress (99m)Tc dual-isotope gated MPS and cardiac catheterization within 3 mo. MF images were obtained by nonlinear warping of cardiac phases to the end-diastolic position. Total perfusion deficit (TPD) was obtained for summed (S-TPD) and motion-frozen (MF-TPD) datasets with sex-specific standard and MF normal limits.', 'The area under the receiver-operating-characteristic (ROC) curve for detection of coronary artery disease (CAD) by MF-TPD was significantly larger than that for S-TPD (0.93 +/- 0.25 vs. 0.88 +/- 0.32, P < 0.05). MF-TPD had higher specificity (77% vs. 55%, P < 0.05) and accuracy (89% vs. 80%, P < 0.05) than did S-TPD.\Question: Does motion-frozen myocardial perfusion SPECT improve detection of coronary artery disease in obese patients?

SOLUTION: MF processing of MPS improves CAD detection in obese patients.

PROBLEM: Context: Mice deficient in apolipoprotein E (apoE(-/-)) develop atherosclerosis. The possible linkage between expression of adhesion molecules/cofactors and atherosclerosis was probed at the level of mRNA and protein expression. The hypothesis of a linkage between changes of adhesion molecules/cofactors and atherosclerosis was tested further by suppression of aortic lesion formation in apoE(-/-) mice by expression of very low levels of transgenic apolipoprotein E.', 'We show that at 8.5 months of age, the apoE(-/-) mice display elevated expression of mRNA for LFA-1, MAC-1, VCAM-1, ICAM-1, and for CD44, as well as MCP-1, cathepsin B, and COX-2 (but not that for eNOS) in atherosclerotic aortic arches. At earlier age, (10-13 week old) apoE(-/-) mice already display elevated expression of mRNA of CD44, LFA-1, MAC-1, VCAM-1, ICAM-1, cathepsin, and of COX-2 in lesioned aortic arches. Expressing very low levels of transgenic apolipoprotein E suppresses both aortic lesions and the expression of mRNA of LFA-1, VCAM-1, MCP-1, cathepsin B, and of ICAM-1 in ApoE(-/-) mice. We tested at the level of protein, the observations obtained for mRNA expression. CD11a (a component of LFA-1), VCAM-1 and cathepsin B expression was found to be elevated in apoE(-/-) aortas at 8-9 months; low level expression of transgenic apolipoprotein E rectifies these changes.\Question: Is altered gene expression in early atherosclerosis blocked by low level apolipoprotein E?

SOLUTION: Atherosclerotic lesions in apoE(-/-) mice are detected as early as 4 weeks of age. Expression of low levels of apoE is shown to be both atheroprotective and to suppress these changes in key adhesion and inflammatory molecules observed in early atherosclerotic lesions.

PROBLEM: Context: Paraoxonase-1 (PON1) is an enzyme that prevents low-density lipoprotein (LDL) oxidation. The role of polymorphisms of PON1 determining early atherosclerotic changes is currently unclear.', 'Cross sectional cohort study.', 'Nine hundred and ninety-nine subjects from a population-based cohort were screened. Intima-media thickness (IMT) was measured by ultrasonography. Leu-Met55 and Gln-Arg192 polymorphism were determined.', 'No association between PON1 genotypes and IMT was found. This finding remained after adjusting for confounding factors.\Question: Are paraoxonase-1 gene Leu-Met55 and Gln-Arg192 polymorphisms associated with carotid artery atherosclerosis in a population-based cohort?

SOLUTION:
The PON1 Leu-Met55 and Gln-Arg192 polymorphisms are not major risk factors for atherosclerosis in the general Caucasian population.