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.

[EX Q]: Brain-derived neurotrophic factor (BDNF) acts rapidly to modulate synaptic neurotransmission in the brain. Although present in neurons, glial cells, and mucosal cells of the colon, and in higher concentrations than in brain, the action of BDNF in gut have not been characterized. The aim of this study was to identify the role of BDNF in mediating the peristaltic reflex.', 'BDNF and a specific antiserum were examined for their effects on the peristaltic reflex and release of the sensory mediators serotonin and calcitonin gene-related peptide in rat colon. The peristaltic reflex and release of serotonin and calcitonin gene-related peptide were also examined in genetically modified mice (BDNF(+/-)) with reduced levels of BDNF.', 'Endogenous brain-derived neurotrophic factor was released into the sensory compartment in a stimulus-dependent manner during the peristaltic reflex induced by mucosal stimulation but not muscle stretch. BDNF stimulated and immunoneutralization of endogenous BDNF reduced ascending contraction and descending relaxation of circular muscle and release of serotonin and calcitonin gene-related peptide during the peristaltic reflex induced by mucosal stimulation but not muscle stretch. The peristaltic reflex and release of serotonin and calcitonin gene-related peptide during the peristaltic reflex induced by mucosal stimulation but not muscle stretch were significantly reduced in BDNF(+/-) mice.
[EX A]: Does brain-derived neurotrophic factor augment peristalsis by augmenting 5-HT and calcitonin gene-related peptide release?

[EX Q]: Regeneration and tolerance factor (RTF) has been recently suggested to contribute to the control of fetal-ablating immunity at the maternal-fetal interface through the induction of T helper 2 (Th2)-dominated response. The protein consists of a membrane-associated domain and an extracellular portion which is proteolitically cleaved to yield a soluble peptide. In humans, it has been shown to be expressed by invading cytotrophoblasts and decidual lymphoid cells, to be increased on peripheral blood B lymphocytes during a normal gestation and on circulating natural killer cells during unsuccessful pregnancies. However, the expression of RTF in other cell types and, specifically, in non-hematopoietic maternal cells of the human uterus has not been characterized in detail. Thus, we have specifically studied the expression and modulation of the cytokine in human endometrium obtained in different phases of the cycle and in early pregnancy.', 'The 20 kDa extracellular domain of RTF has been localized by immunohistochemical method and Western blot analysis. Levels of RTF messenger RNA (mRNA) in basal and stimulated conditions have been evaluated by semiquantitative reverse transcription-polymerase chain reaction.', 'The extracellular domain of RTF could be detected in both the glandular epithelium and stroma with diffuse distribution in both cycling endometrium and first trimester decidua. Both cycling and pregnant endometrium expressed the gene for RTF but mRNA levels resulted significantly increased in secretory phase-endometrial stromal cells when compared to proliferative phase samples. Inflammatory cytokines, interleukin-1beta and tumour necrosis factor alpha were able to directly increase endometrial RTF mRNA expression.
[EX A]: Is the placental immunomodulatory cytokine regeneration and tolerance factor also expressed by both human cycling and early pregnant endometrium?

[EX Q]: Lymph node size as a prognostic parameter has not been investigated well in the past. Recent data, however, have indicated that this parameter could be even more important than the lymph node count.', 'Based on the results of earlier studies, we analyzed the lymph node size and number of node-negative colon cancer patients with regard to survival. Data from 115 node-negative cases of colon cancer were analyzed. Lymph nodes with diameters ≤5 mm were defined as small, and all other lymph nodes were classified as intermediate/large in size and labeled LN5. All of the cases were categorized according to the number of LN5s. The LN5 very low (LN5vl) group included cases with less than two LN5s. All of the other cases were assigned to the LN5 low/high (LN5l/h) group.', 'The overall survival analysis revealed significantly worse outcomes for the LN5vl group, with a mean survival of 34 months compared to the LN5l/h group, with a mean survival of 40 months (P\u2009=\u20090.022). After adjusting for the pT1/2 and pT3/4 stages, we still found a significant outcome difference (P\u2009=\u20090.012). Multivariate analysis identified LN5vl and T-stage as being independently correlated with the outcome. The vast majority of LN5vl cases (91 %) were located in the left colon. The location itself, however, was not prognostic (P\u2009=\u20090.478).
[EX A]:
Is lymph node hypoplasia associated with adverse outcomes in node-negative colon cancer using advanced lymph node dissection methods?