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.

Q: Context: This study was conducted to quantify the effect of multidisciplinary care (MDC) on amputation-free survival (AFS) and wound healing within a chronic critical limb ischemia (CLI) population.', 'We performed a retrospective, single-center cohort study of consecutive CLI patients presenting to the Vascular Surgery Service. Patients who received initial and follow-up wound care from the MDC were compared with patients who received standard wound care (SWC). The MDC team consisted of vascular, plastic, and podiatric surgeons who jointly managed wound care and directed any other consults or services as deemed necessary. SWC consisted of an inconsistent mix of providers without a defined manager, including nurses, wound care midlevel providers, general surgeons, internists, or the patients themselves. The referring physician determined the allocation of patients. The primary outcome variable was AFS, with a secondary evaluation of wound healing. The effects of baseline demographics, comorbid medical conditions, laboratory values, ischemic lesion severity and location, Rutherford classification, and participation in MDC were assessed. Significant univariate predictors (P < .10) of AFS were entered into a multivariate Cox regression model and assessed at an α = .05.', 'Between August 2010 and June 2012, 146 CLI patients (91 male [63%]) were evaluated by the Vascular Surgery Service and were followed up for a median of 539 days (interquartile range 314-679 days). Ischemic tissue loss was present in 85 patients (38 at Rutherford category 5, and 47 at Rutherford category 6). Within this cohort, 51 (60%) had MDC, and 34 (40%) had SWC. Fifty-eight patients (68%) underwent revascularization (open in 17, endovascular in 35, and hybrid in 6), 14 (8%) were managed with primary major amputation, and 13 (15%) declined revascularization. AFS was superior for patients in the MDC arm vs the SWC arm (593.3 ± 53.5 days vs 281.0 ± 38.2 days; log-rank, P = .02). Wound-healing times favored the MDC arm over the SWC arm (444.5 ± 33.2 days vs 625.2 ± 126.5 days), although this was not statistically significant (log-rank, P = .74). Multivariate modelling revealed that independent predictors of major amputation or death, or both, were nonrevascularized patients (hazard ratio [HR], 3.76; 95% confidence interval [CI], 1.78-8.02; χ(2), P < .01), treatment by SWC (HR, 2.664; 95% CI, 1.23-5.77; χ(2), P = .012), and baseline nonambulatory status (HR, 1.89; 95% CI, 1.17-2.85; χ(2), P < .01).
Answer: MDC pathways for the management of a population of CLI patients improved AFS by greater than twofold and should be the standard of care for the CLI population. Baseline nonambulatory status and unrevascularized patients also predict worse AFS. Wound healing remains prolonged regardless of preoperative or postoperative wound care. Future study is required to evaluate the costs and functional outcomes for MDC in the management of CLI.

A: Does multidisciplinary care improve amputation-free survival in patients with chronic critical limb ischemia?
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Q: Context: A fundamental prerequisite for using degradable synthetic biopolymers as composite skin substitutes is the ability to establish vascular tissue. PEGT/PBT block-copolymer matrices have previously been shown as a favorable dermal substitute. In this study, quantitative data on neovascularization of PEGT/PBT block-copolymer matrices are presented.', 'PEGT/PBT-block-copolymer discs of three different pore diameters (1: < 75 microm, 2: 75-212 microm, 3: 250-300 microm) were implanted into dorsal skinfold chambers of balb/c mice. Histological sections were evaluated 7, 14, and 21 days post implantation by light and scanning electron microscopy. Blood vessel analysis was performed by means of digital image analysis (n = 288) of hematoxylin/eosin stained sections within apical (AOF) and basal (BOF) observation fields of the matrices.', 'Twenty-one days after implantation the density of blood vessels within the BOF of the scaffolds with a pore size of 75-212 and 250-300 microm were 4.6 +/- 0.45 and 5.8 +/- 0.62 (mean +/- S.E.M.; blood vessel profiles (BVF)), respectively. In <75 microm scaffolds, smaller numbers of BVF were found (4.2 +/- 0.39). In contrast, the evaluation within the AOF revealed significantly higher numbers of BVF in 75-212 microm group (3.5 +/- 0.49) and 250-300 microm group (4.5 +/- 0.66) as compared to the < 75 microm group (2.3 +/- 0.48).
Answer: There is evidence that the three-dimensional structure of PEGT/PBT-block-copolymer (pore size structure) influences neovascularization. The porous structures of copolymer matrices with adequate interconnection of pores (pore sizes of 75-212 and 250-300 microm) are characterized by faster ingrowth of vascular tissue.

A: Does analysis of neovascularization of PEGT/PBT-copolymer dermis substitute in balb/c-mice?
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Q: Context: Endothelin-1 levels are raised in chronic thromboembolic pulmonary hypertension. Our aim in this study was to identify the presence of endothelin receptors in patients with CTEPH by analysing tissue removed at pulmonary endarterectomy.', 'Pulmonary endarterectomy tissue cross-sections were analysed using autoradiography with [(125)I]-ET-1 using ligands selective for ETA or ETB to determine sub-type distribution. The precise cellular localisation of ETA and ETB receptors was determined using selective antisera to both sub-types and compared with haematoxylin and eosin, Elastic Van Gieson and smooth muscle actin labelled sections.', 'Two patterns of ET-1 binding were found. In sections with frequent recanalised channels, ET-1 bound to the smooth muscle cells surrounding the channels. In sections where there was less organised thrombus with no obvious re-canalisation, minimal ET-1 binding was observed. Some contractile type smooth muscle cells not associated with recanalised channels and diffusely spread throughout the PEA material were associated with ET receptor antibody binding on immunohistochemistry. There was a greater expression of the ETA receptor type in the specimens.
Answer: The presence of ET-1 receptors in the chronic thrombus in proximal CTEPH suggests ET-1 could act not only on the distal vasculopathy in the unobstructed vessels but may also stimulate smooth muscle cell proliferation within chronic clot. The abundance of ET receptors within the tissue provides evidence that the ET pathway is involved in the pathology of chronic thrombus reorganisation leading to CTEPH providing a rationale for the repurposing of ET receptor antagonists in the treatment of this condition.

A:
Do endothelin ETA receptors predominate in chronic thromboembolic pulmonary hypertension?
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