TASK DEFINITION: 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.
PROBLEM: Context: Lynch syndrome is caused by germline mutations in DNA mismatch repair genes leading to microsatellite instability (MSI) and colorectal cancer. Mesalazine, commonly used for the treatment of UC, reduces MSI in vitro. Here, we tested natural compounds for such activity and applied mesalazine and thymoquinone in a Msh2(loxP/loxP) Villin-Cre mouse model for Lynch syndrome.', 'Flow cytometry was used for quantitation of mutation rates at a CA13 microsatellite in human colon cancer (HCT116) cells that had been stably transfected with pIREShyg2-enhanced green fluorescent protein/CA13, a reporter for frameshift mutations. Mice were treated for 43weeks with mesalazine, thymoquinone or control chow. Intestines were analysed for tumour incidence, tumour multiplicity and size. MSI testing was performed from microdissected normal intestinal or tumour tissue, compared with mouse tails and quantified by the number of mutations per marker (NMPM).', 'Besides mesalazine, thymoquinone significantly improved replication fidelity at 1.25 and 2.5M in HCT116 cells. In Msh2(loxP/loxP) Villin-Cre mice, tumour incidence was reduced by mesalazine from 94% to 69% (p=0.04) and to 56% (p=0.003) by thymoquinone. The mean number of tumours was reduced from 3.1 to 1.4 by mesalazine (p=0.004) and to 1.1 by thymoquinone (p<0.001). Interestingly, MSI was reduced in normal intestinal tissue from 1.5 to 1.2 NMPM (p=0.006) and to 1.1 NMPM (p=0.01) by mesalazine and thymoquinone, respectively. Thymoquinone, but not mesalazine, reduced MSI in tumours.
Answer: Mesalazine and thymoquinone reduce tumour incidence and multiplicity in Msh2(loxP/loxP) Villin-Cre mice by reduction of MSI independent of a functional mismatch repair system. Both substances are candidate compounds for chemoprevention in Lynch syndrome mutation carriers.

SOLUTION: Do mesalazine and thymoquinone attenuate intestinal tumour development in Msh2 ( loxP/loxP ) Villin-Cre mice?

PROBLEM: Context: Chronic stress is generally known to exacerbate the development of numerous neuropsychiatric diseases such as fear and anxiety disorders, which is at least partially due to the disinhibition of amygdala subsequent to the prolonged stress exposure. GABA receptor A (GABAAR) mediates the primary component of inhibition in brain and its activation produces two forms of inhibition: the phasic and tonic inhibition. While both of them are critically engaged in limiting the activity of amygdala, their roles in the amygdala disinhibition subsequent to chronic stress exposure are largely unknown.', 'We investigated the possible alterations of phasic and tonic GABAAR currents and their roles in the amygdala disinhibition subsequent to chronic stress. We found that both chronic immobilization and unpredictable stress led to long lasting loss of tonic GABAAR currents in the projection neurons of lateral amygdala. By contrast, the phasic GABAAR currents, as measured by the spontaneous inhibitory postsynaptic currents, were virtually unaltered. The loss of tonic inhibition varied with the duration of daily stress and the total days of stress exposure. It was prevented by pretreatment with metyrapone to block corticosterone synthesis or RU 38486, a glucocorticoid receptor antagonist, suggesting the critical involvement of glucocorticoid receptor activation. Moreover, chronic treatment with corticosterone mimicked the effect of chronic stress and reduced the tonic inhibition in lateral amygdala of control mice. The loss of tonic inhibition resulted in the impaired GABAergic gating on neuronal excitability in amygdala, which was prevented by metyrapone pretreatment.
Answer: Our study suggests that enduring loss of tonic but not phasic GABAAR currents critically contributes to the prolonged amygdala disinhibition subsequent to chronic stress. We propose that the preferential loss of tonic inhibition may account for the development of stress-related neuropsychiatric diseases.

SOLUTION: Does chronic stress impair GABAergic control of amygdala through suppressing the tonic GABAA receptor currents?

PROBLEM: Context: Fusobacterium nucleatum, a commensal opportunistic oral bacterium, is capable of invading gingival epithelial cells, but the entrance into human primary oral fibroblast cells has not been documented. This study evaluated the ability of three strains of F. nucleatum (F. nucleatum ssp. nucleatum, F. nucleatum ssp. polymorphum, and F. nucleatum ssp. vincentii) to enter gingival fibroblasts (GFs) and periodontal ligament fibroblasts (PLFs).', 'GFs and PLFs were cocultured for various periods of time with different strains of F. nucleatum. Scanning and transmission electron microscopy, together with confocal laser scanning microscopy, were used to visualize the entrance and presence of bacteria in host cells. Flow cytometry was performed to compare the load of internalized bacteria in GFs and PLFs exposed for 3 and 5 hours to live F. nucleatum labeled with fluorescein isothiocyanate.', 'All three strains of F. nucleatum were found entering and located in the cytoplasm of GFs and PLFs after 1 hour of exposure. Flow cytometry tests revealed a significant increase in the fluorescent signal, compared to baseline, derived from bacteria internalized in fibroblasts exposed for 3 hours (P <0.001); a further increase was found at 5 hours. The greatest bacterial mass in exposed fibroblasts of both types was of F. nucleatum ssp. polymorphum; the smallest was of F. nucleatum ssp. vincentii. Although not statistically significant, PLFs had a higher bacterial load than corresponding GFs.
Answer: F. nucleatum was capable of entering GFs and PLFs in a manner that is dependent on the cell type and the bacterial strain.

SOLUTION:
Does fusobacterium nucleatum enter normal human oral fibroblasts in vitro?