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: Anxiety and depression frequently co-occur in the elderly and in patients with dementia. Prior research has shown that depression is related to the risk of dementia, but the effect of anxiety on dementia remains unclear. We studied whether anxiety symptoms and anxiety disorders are associated with the risk of dementia and cognition.', 'We studied 2,708 nondemented participants from the prospective, population-based Rotterdam Study who underwent the Hospital Anxiety and Depression Scale (HADS) (sample I, baseline 1993-1995) and 3,069 nondemented participants who underwent screening for anxiety disorders (sample II, baseline 2002-2004). In 1993-1995, anxiety symptoms were assessed using the HADS. In 2002-2004, anxiety disorders were assessed using the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition. In both study samples, participants were continuously monitored for dementia until January 1, 2011. Cognition was tested in 2002-2004 and at a follow-up visit in 2009-2011 in sample II only.', 'In sample I, 358 persons developed dementia, and in sample II, 248 persons developed dementia. We did not find an association with the risk of dementia for anxiety symptoms (hazard ratio 1.05, 95% confidence interval: 0.77-1.43, Wald statistic 0.08, p\xa0= 0.77, df\xa0= 1) or for anxiety disorders (hazard ratio 0.92, 95% confidence interval: 0.58-1.45, Wald statistic 0.14, p\xa0= 0.71, df\xa0= 1). We could demonstrate an association of anxiety disorders with poor cognition cross-sectionally, but this attenuated after additional adjustments.

SOLUTION: Is anxiety associated with the risk of dementia or cognitive decline : the Rotterdam Study?

PROBLEM: Large concentrations of meperidine inhibit N-methyl-D-aspartate-(NMDA) receptor channels by channel block mechanisms. Extracellular pH regulates the activity and drug sensitivity of NMDA-receptor channels. We examined the influence of extracellular pH on sensitivity to meperidine of epsilon/zeta heteromeric NMDA-receptor channels expressed in Xenopus oocytes. Inhibition of epsilon1/zeta1, epsilon2/zeta1, epsilon3/zeta1, and epsilon4/zeta1 channels by meperidine was dependent on pH, with more inhibition at acidic pH and less inhibition at alkaline pH. The degree of voltage-dependence of meperidine block was only slightly affected by changes in pH, whereas affinity for meperidine was greatly reduced at alkaline pH. Furthermore, interaction of meperidine with Mg(2+) block was reduced at alkaline pH. Because the percentage of the protonated form of meperidine is only slightly affected by pH, changes in properties of the meperidine binding site may be involved in mechanisms of alteration of meperidine potency by pH.

SOLUTION: Is n-methyl-D-aspartate receptor channel block by meperidine dependent on extracellular pH?

PROBLEM: Epigenetic dysregulation is implicated in pituitary neoplasia as the cause of silencing of several tumor suppressor genes. However, the upstream mediators of such events remain unknown.', 'We examined the three members of the DNA methyltransferase (DNMT) enzyme family in normal and neoplastic human and mouse pituitary cells.', 'This study was performed at a university-affiliated cancer research institute.', 'Gene expression, promoter DNA methylation, histone modifications, and cell proliferation were determined.', "In contrast to DNMT1 and DNMT3a, DNMT3b was expressed at relatively higher levels in neoplastic pituitary cells. However, examination of the human DNMT3b 5' region showed uniformly low DNA methylation levels with little difference between normal and tumor samples. Through pharmacological methylation inhibition or histone deacetylation inhibition, we identified that DNMT3b gene expression is subject to histone modifications. Down-regulation of DNMT3b resulted in induction of retinoblastoma, p21, and p27, and reduction in cell proliferation. These targeted effects were associated with enhanced histone 3 acetylation and diminished histone methylation.

SOLUTION:
Does deoxyribonucleic acid methyltransferase 3B promote epigenetic silencing through histone 3 chromatin modifications in pituitary cells?