TASK DEFINITION: Given a passage, 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: Genetic variability in hepatic uptake was recently shown to influence the disposition and cholesterol-lowering effects of statins. Ezetimibe, an inhibitor of the intestinal cholesterol uptake protein Niemann-Pick C 1 like 1, is another drug for which genetic polymorphisms of hepatic organic anion transporting polypeptides (OATPs) are expected to be of clinical relevance because ezetimibe undergoes intensive enterohepatic circulation for which hepatic uptake transporters may be rate-limiting determinants.', 'Using OATP1B3-, OATP2B1-, and OATP1B1-transfected HEK cells, including the OATP1B1 variants OATP1B1*1b and OATP1B1*5, we measured the uptake of ezetimibe and its glucuronide and we analyzed the competition with the common OATP-substrate bromosulfophthalein. Disposition and sterol-lowering effects of 20-mg ezetimibe were measured in 35 healthy participants genotyped for OATP1B1, ABCB1, ABCC2, and UGT1A1.', 'Ezetimibe glucuronide inhibited bromosulfophthalein uptake in all OATP-transfected cells (50% inhibitory concentration (IC50): 0.14-0.26 mumol/l) whereas ezetimibe was 30-100 times less potent. Only the glucuronide was accumulated significantly in cells expressing OATP1B1 and OATP2B1. Its uptake in cells expressing OATP1B1*1b and *5 was reduced. In-vivo studies showed there was a gene-dose-dependent decrease in the area under the curve of ezetimibe in participants with the OATP1B1*1b protein (*1a/*1a, N=12, 112+/-66 ngxh/ml vs. *1a/*1b, N=8, 88+/-39 ngxh/ml vs. *1b/*1b, N=5, 55+/-18 ngxh/ml; Jonkheere-Terpstra, P=0.041) and a tendency for increased glucuronide exposure (704+/-296 vs. 878+/-369 vs. 1059+/-363 ngxh/ml; P=0.092). Fecal ezetimibe excretion was significantly decreased whereas renal glucuronide excretion was increased in carriers of *1b/*1b. Fecal excretion was also diminished in carriers of OATP1B1*5 and *15. The sterol-lowering effect of ezetimibe was not influenced by OATP1B1 polymorphisms.

SOLUTION: Is disposition of ezetimibe influenced by polymorphisms of the hepatic uptake carrier OATP1B1?

PROBLEM: The donkey (Equus asinus) is an important domestic animal that provides a reliable source of protein and method of transportation for many human populations. However, the process of domestication and the dispersal routes of the Chinese donkey are still unclear, as donkey remains are sparse in the archaeological record and often confused with horse remains. To explore the maternal origins and dispersal route of Chinese donkeys, both mitochondrial DNA D-loop and cytochrome b gene fragments of 21 suspected donkey remains from four archaeological sites in China were amplified and sequenced.', 'Molecular methods of species identification show that 17 specimens were donkeys and three samples had the maternal genetic signature of horses. One sample that dates to about 20,000 years before present failed to amplify. In this study, the phylogenetic analysis reveals that ancient Chinese donkeys have high mitochondrial DNA diversity and two distinct mitochondrial maternal lineages, known as the Somali and Nubian lineages. These results indicate that the maternal origin of Chinese domestic donkeys was probably related to the African wild ass, which includes the Nubian wild ass (Equus africanus africanus) and the Somali wild ass (Equus africanus somaliensis). Combined with historical records, the results of this study implied that domestic donkeys spread into west and north China before the emergence of the Han dynasty. The number of Chinese domestic donkeys had increased primarily to meet demand for the expansion of trade, and they were likely used as commodities or for shipping goods along the Silk Road during the Tang Dynasty, when the Silk Road reached its golden age.

SOLUTION: Does ancient DNA provide new insight into the maternal lineages and domestication of Chinese donkeys?

PROBLEM: Oxidative stress is central to the pathogenesis of Parkinson's disease (PD), but the mechanisms involved in the control of this stress in dopaminergic cells are not fully understood. There is increasing evidence that selenoproteins play a central role in the control of redox homeostasis and cell defense, but the precise contribution of members of this family of proteins during the course of neurodegenerative diseases is still elusive.", 'We demonstrated first that selenoprotein T (SelT) whose gene disruption is lethal during embryogenesis, exerts a potent oxidoreductase activity. In the SH-SY5Y cell model of dopaminergic neurons, both silencing and overexpression of SelT affected oxidative stress and cell survival. Treatment with PD-inducing neurotoxins such as 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) or rotenone triggered SelT expression in the nigrostriatal pathway of wild-type mice, but provoked rapid and severe parkinsonian-like motor defects in conditional brain SelT-deficient mice. This motor impairment was associated with marked oxidative stress and neurodegeneration and decreased tyrosine hydroxylase activity and dopamine levels in the nigrostriatal system. Finally, in PD patients, we report that SelT is tremendously increased in the caudate putamen tissue.', 'These results reveal the activity of a novel selenoprotein enzyme that protects dopaminergic neurons against oxidative stress and prevents early and severe movement impairment in animal models of PD.

SOLUTION:
Does selenoprotein T exert an Essential Oxidoreductase Activity That Protects Dopaminergic Neurons in Mouse Models of Parkinson 's Disease?