instruction:
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.
question:
Context: For patients with small bowel obstruction (SBO), who do not have strangulation obstruction or other contraindications, long tube decompression has been successful in 75% in two studies. In a 1995 prospective randomized study, comparing nasogastric suction (short tube) with long tube decompression, the short tube was successful in 51% and the long tube was successful in 75%. Using upper gastrointestinal endoscopy, a long tube can be advanced into the jejunum in 20 minutes, so the delay in function has been eliminated.', 'There were 35 patients with 37 episodes of SBO. From 1983 to 1988, three tubes then available were advanced endoscopically into the jejunum in 17 patients. From 1989 to 2002, an improved tube designed for endoscopic placement was used in 20 patients.', 'From 1983 to 1988 using three tubes, long tube decompression was successful in 12 of 17 (70%); from 1989 to 2002 with the improved tube, decompression was successful in 18 of 20 (90%).\Question: Is long tube decompression successful in 90 % of patients with adhesive small bowel obstruction?
answer:
For patients with SBO due to adhesions, a trial with long tube decompression for 48 to 72 hours is recommended. For those who fail a trial with the long tube, laparotomy with enterolysis or bowel resection is indicated. If the operative findings indicate a high risk for recurrent obstruction, then long tube splinting of the small bowel should be considered.

question:
Context: Chromatin epigenetics participate in control of gene expression during metazoan development. DNA methylation and post-translational modifications (PTMs) of histones have been extensively characterised in cell types present in, or derived from, mouse embryos. In embryonic stem cells (ESCs) derived from blastocysts, factors involved in deposition of epigenetic marks regulate properties related to self-renewal and pluripotency. In the germ lineage, changes in histone PTMs and DNA demethylation occur during formation of the primordial germ cells (PGCs) to reset the epigenome of the future gametes. Trimethylation of histone H3 on lysine 27 (H3K27me3) by Polycomb group proteins is involved in several epigenome-remodelling steps, but it remains unclear whether these epigenetic features are conserved in non-mammalian vertebrates. To investigate this question, we compared the abundance and nuclear distribution of the main histone PTMs, 5-methylcytosine (5mC) and 5-hydroxymethylcytosine (5hmC) in chicken ESCs, PGCs and blastodermal cells (BCs) with differentiated chicken ESCs and embryonic fibroblasts. In addition, we analysed the expression of chromatin modifier genes to better understand the establishment and dynamics of chromatin epigenetic profiles.', 'The nuclear distributions of most PTMs and 5hmC in chicken stem cells were similar to what has been described for mammalian cells. However, unlike mouse pericentric heterochromatin (PCH), chicken ESC PCH contained high levels of trimethylated histone H3 on lysine 27 (H3K27me3). In differentiated chicken cells, PCH was less enriched in H3K27me3 relative to chromatin overall. In PGCs, the H3K27me3 global level was greatly reduced, whereas the H3K9me3 level was elevated. Most chromatin modifier genes known in mammals were expressed in chicken ESCs, PGCs and BCs. Genes presumably involved in de novo DNA methylation were very highly expressed. DNMT3B and HELLS/SMARCA6 were highly expressed in chicken ESCs, PGCs and BCs compared to differentiated chicken ESCs and embryonic fibroblasts, and DNMT3A was strongly expressed in ESCs, differentiated ESCs and BCs.\Question: Do chicken embryonic stem cells and primordial germ cells display different heterochromatic histone marks than their mammalian counterparts?
answer:
Chicken ESCs and PGCs differ from their mammalian counterparts with respect to H3K27 methylation. High enrichment of H3K27me3 at PCH is specific to pluripotent cells in chicken. Our results demonstrate that the dynamics in chromatin constitution described during mouse development is not universal to all vertebrate species.

question:
Context: Oxidant stress contributes to vascular injury and atherosclerosis. We hypothesized that estrogen treatment of ovariectomized rats decreases O(2)(-) by decreasing the activity of NAD(P)H oxidase and this reduction in O(2)(-) could have a vasculoprotective effect.', 'Ovariectomized rats were treated with 17-beta-estradiol E2 (0.25mg) or oil placebo for 21 days. Aorta were removed for contractility studies and O(2)(-) production was measured by lucigenin enhanced chemiluminescence (230 and 5microM). E2 treatment decreased basal O(2)(-) production but did not alter NADH or NADPH stimulated O(2)(-) production. Total p47phox and p47phox in membrane fractions of cardiac tissue were decreased, which suggests less activation of NAD(P)H oxidase in E2 treated rats. E2 did not change expression of other components of NAD(P)H oxidase in heart, lung, spleen and diaphragm. Expression of eNOS was also lower in E2 treated rats. E2 did not affect the contractile response to phenylepherine, dilation with acetylcholine, dilation with superoxide dismutase or constriction with l-NAME. This argues against changes in bioavailable NO.\Question: Does treatment with 17-beta-estradiol reduce superoxide production in aorta of ovariectomized rats?
answer:
E2 decreases activation of p47phox and O(2)(-) production by NAD(P)H oxidase. This did not affect contractile properties of the vessel, but could still potentially alter cell signaling from oxidant increasing stresses.