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.
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Question: The biliary cast syndrome (BCS) is a frequent problem following liver transplantation. The pathogenesis of this complication is not well understood. Previous research has demonstrated that the soluble form of MICA (sMICA) is significantly higher in patients with chronic liver disease and hepatocellular carcinoma (HCC) than in healthy volunteers. The aim of this study is to investigate the possible involvement of sMICA in the formation of BCS after liver transplantation.', 'Serum soluble MICA was retrospectively evaluated in pre- and post-transplant sera from 133 consecutive primary liver transplant patients and in sera from 88 healthy volunteers using sandwich ELISA. Normal distribution of serum sMICA was described by the data obtained from healthy population and sMICA concentration that was greater than the upper bound 95% normal range was considered as high levels of sMICA. Patient records were reviewed to identify patients who developed BCS.', 'The results demonstrated that 37.6% of patients with end-stage liver diseases had significantly higher pre-transplant serum sMICA than in healthy population. 34.4% of recipients with post-transplant high levels of sMICA developed BCS. In contrast, 17.3% of patients with post-transplant normal levels of sMICA developed BCS. The risk of BCS development is significantly associated with the presence of post-transplant high levels of sMICA (P=0.0365). Further analysis disclosed that patients with decreased post-transplant sMICA following liver transplantation had a lower incidence rate of BCS than those with remained high levels of sMICA after transplantation (10.5% vs. 38.7%, P=0.0302). Furthermore, log-rank test showed that BCS occurrence was significantly associated with dynamic changes of sMICA among different groups (P=0.0188).

Answer: Are high levels of soluble Major Histocompatibility Complex class I related chain A ( MICA ) associated with biliary cast syndrome after liver transplantation?

Question: Left ventricular aneurysm repair (LVR) reduces LV wall stress and improves LV function. However, as we reported previously, the initial improvement of LVR was short-term because of LV remodeling but could be maintained longer with postoperative use of an angiotensin-converting enzyme (ACE) inhibitor. Atrial natriuretic peptide (ANP) has been used to treat patients with heart failure by natriuretic and vasodilatory actions. Recent reports have suggested that ANP inhibits the rennin-angiotensin system. In this study, the effects of ANP after LVR were evaluated.', 'Rats that had an LV aneurysm 4 weeks after left anterior descending artery ligation underwent LVR by plicating the LV aneurysm and were randomized into 2 groups: LVR+A group was intravenously administrated with 10 microg/h of carperitide, recombinant alpha-hANP, by osmotic-pump for 4 weeks, and the LVR group was given normal saline. Echocardiography revealed better LV remodeling and function in LVR+A group than in LVR group. Four weeks after LVR, left ventricular end diastolic pressure (LVEDP) and Tau were significantly lower in LVR+A group (LVEDP: 10+/-4 in LVR+A group versus 18+/-6 mm Hg in LVR group, Tau: 13+/-2 versus 17+/-2ms). End-systolic elastance (Ees) was higher in LVR+A group (Ees: 0.34+/-0.2 versus 0.19+/-0.11 mm Hg/microL). The levels of myocardial ACE activity in LVR+A group was significantly lower than in LVR group. The mRNA expressions of brain natriuretic peptide and transforming growth factor beta1 inducing fibrosis significantly decreased in LV myocardium in LVR+A group. Histologically, myocardial fibrosis was significantly reduced in LVR+A group.

Answer: Does atrial natriuretic peptide help prevent late remodeling after left ventricular aneurysm repair?

Question: Incomplete mitral leaflet coaptation during acute left ventricular ischemia is associated with end-diastolic mitral annular dilatation and ischemic mitral regurgitation. Annular rings were implanted in sheep to investigate whether annular reduction alone is sufficient to prevent mitral regurgitation during acute posterolateral left ventricular ischemia.', 'Radiopaque markers were inserted around the mitral anulus, on papillary muscle tips, and on the central meridian of both mitral leaflets in three groups of sheep: control (n = 5), Physio ring (n = 5) (Baxter Cardiovascular Div, Santa Ana, Calif), and Duran ring (n = 6) (Medtronic Heart Valve Div, Minneapolis, Minn). After 8 +/- 1 days, animals were studied with biplane videofluoroscopy before and during left ventricular ischemia. Annular area was calculated from 3-dimensional marker coordinates and coaptation defined as minimal distance between leaflet edge markers.', 'Before ischemia, leaflet coaptation occurred just after end-diastole in all groups (control 17 +/- 41, Duran 33 +/- 30, Physio 33 +/- 24 ms, mean +/- SD, P >.2 by analysis of variance). During ischemia, regurgitation was detected in all control animals, and leaflet coaptation was delayed to 88 +/- 8 ms after end-diastole (P =.02 vs preischemia). This was associated with increased end-diastolic annular area (8.0 +/- 0.9 vs 6.7 +/- 0.6 cm(2), P =.004) and septal-lateral annular diameter (2.9 +/- 0.1 vs 2.5 +/- 0.1 cm, P =.02). Mitral regurgitation did not develop in Duran or Physio sheep, time to coaptation was unchanged (Duran 25 +/- 25 ms, Physio 30 +/- 48 ms [both P >.2 vs preischemia]), and annular area remained fixed.

Answer:
Does ring annuloplasty prevent delayed leaflet coaptation and mitral regurgitation during acute left ventricular ischemia?