instruction:
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.
question:
Fractional CO2 laser has recently emerged as a promising therapeutic modality to improve the texture and appearance of burn scars. An issue in many burn scars is persistent erythema, which traditionally has been treated with vascular lasers. Interestingly, fractional CO2 lasers have been shown to improve the appearance of burn scars, including erythema, but no mechanism has been proposed for this change. Our objective is to evaluate the histopathologic changes in vasculature in burn scars treated with fractionated CO2 laser, and to attempt to describe the mechanism behind reduced erythema following treatment.', 'Uncontrolled, prospective study of ten patients with mature burn scars, from a clinical and histological perspective. Biopsy specimens were obtained before and 2 months after 3 treatment sessions. Anti-CD31 immunostaining was performed to highlight vascular patterns in biopsy specimens.', 'In histological analysis, an increase in vascular density, particularly of small caliber vessels, was seen following treatment, with an 82.6% average increase in vasculature (P\u2009=\u20090.028). This increase in vascularity correlated with a decrease in clinical erythema and vascularity scores, measured using the Vancouver Scar Scale.
answer:
Do vascular patterns in mature hypertrophic burn scars treated with fractional CO2 laser?


question:
Right ventricular pacing (RVP) has been associated with heart failure and increased mortality. His-bundle pacing (HBP) is more physiological but requires a mapping catheter or a backup right ventricular lead and is technically challenging.', 'We sought to assess the feasibility, safety, and clinical outcomes of permanent HBP in an unselected population as compared to RVP.', 'All patients requiring pacemaker implantation routinely underwent attempt at permanent HBP using the Select Secure (model 3830) pacing lead in the year 2011 delivered through a fixed-shaped catheter (C315 HIS) at one hospital and RVP at the second hospital. Patients were followed from implantation, 2 weeks, 2 months, 1 year, and 2 years. Fluoroscopy time (FT), pacing threshold (PTh), complications, heart failure hospitalization, and mortality were compared.', 'HBP was attempted in 94 consecutive patients, while 98 patients underwent RVP. HBP was successful in 75 patients (80%). FT was similar (12.7 ± 8 minutes vs 10 ± 14 minutes; median 9.1 vs 6.4 minutes; P = .14) and PTh was higher in the HBP group than in the RVP group (1.35 ± 0.9 V vs 0.6 ± 0.5 V at 0.5 ms; P < .001) and remained stable over a 2-year follow-up period. In patients with >40% ventricular pacing (>60% of patients), heart failure hospitalization was significantly reduced in the HBP group than in the RVP group (2% vs 15%; P = .02). There was no difference in mortality between the 2 groups (13% in the HBP group vs 18% in the RVP group; P = .45).
answer:
Is permanent His-bundle pacing feasible , safe , and superior to right ventricular pacing in routine clinical practice?


question:
Our prior studies show that intravenous (IV) total parenteral nutrition (TPN) produces atrophy of the small intestine-related gut-associated lymphoid tissue and significant decreases in intestinal IgA levels, the major system of mucosal immunity. Others have noted increased small intestinal permeability, bacterial adherence and translocation, and decreased IgA levels in TPN-fed animals. Bombesin, a neuropeptide, may play a regulatory role in mucosal immunity. It is not clear whether bombesin attenuates the TPN-associated gut-associated lymphoid tissue atrophy.', 'To examine the effect of bombesin on gut-associated lymphoid tissue integrity and function during IV TPN feeding.', 'Randomized animal study.', 'A university laboratory.', "Male ICR mice weighing 25 to 30 g were randomized to chow plus IV saline solution (n = 12), IV TPN (n = 12), or IV TPN plus bombesin (15 micrograms/kg, administered intramuscularly three times a day) (n = 12). Animals were killed after 5 days of receiving the experimental diet. Total small intestinal IgA level was quantified by enzyme-linked immunosorbent assay. Lymphocytes were isolated from Peyer's patches, intraepithelial spaces, and lamina propria and were stained with specific antibodies for B and T cells and for T-cell expression of CD4 and CD8 by flow cytometric analysis. Data were analyzed by analysis of variance.", "Bombesin prevented the IV TPN decreases in (1) total cell yield and B-cell yield from the Peyer's patches, intraepithelial spaces, and lamina propria; (2) T-cell yield in the intraepithelial spaces and lamina propria; and (3) small intestinal IgA levels. Bombesin also reversed IV TPN decreases in CD4+ and CD8+ T cells in the intraepithelial spaces and Peyer's patches and prevented the decrease in the CD4/CD8 ratio in the lamina propria.
answer:

Does bombesin affect mucosal immunity and gut-associated lymphoid tissue in intravenously fed mice?