TASK DEFINITION: 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.
PROBLEM: Context: Ischemic mitral regurgitation (MR) often persists after restrictive mitral valve annuloplasty, in which case it is associated with worse clinical outcomes. The goal of the present study was to determine whether persistence of MR and/or clinical outcome could be predicted from preoperative analysis of mitral valve configuration.', 'In 51 consecutive patients undergoing restrictive annuloplasty for ischemic MR, posterior leaflet (PL) angle, anterior leaflet angle, coaptation distance, and tenting area were quantified by echocardiography before surgery (6+/-3 days), and MR severity was assessed before and early after surgery (9+/-4 days). Postoperatively, persistence of mild to moderate MR (vena contracta > 3 mm) was observed in 11 (22%) of the patients. The best predictor of postoperative persistence of MR was a PL angle > or = 45 degrees (sensitivity 100%, specificity 97%, positive predictive value 92%, negative predictive value 100%). Patients with persistent MR had markedly lower 3-year event-free survival (26+/-20%) compared with those with nonpersistent MR (75+/-12%, P=0.01). Preoperative presence of a PL angle > or = 45 degrees also was associated with a markedly lower 3-year event-free survival (22+/-17% versus 76+/-12%; P<0.001).
Answer: In patients undergoing restrictive annuloplasty for ischemic MR, persistence of MR and 3-year event-free survival can accurately be predicted by preoperative analysis of mitral valve configuration. Patients with a PL angle > or = 45 degrees (ie, with high PL restriction) should thus be considered poor candidates for this procedure, and concomitant or alternative procedures should be contemplated.

SOLUTION: Does preoperative posterior leaflet angle accurately predict outcome after restrictive mitral valve annuloplasty for ischemic mitral regurgitation?

PROBLEM: Context: Two years ago the authors began to use Swan-Ganz catheters to generate more complex hemodynamic data as a better guide to resuscitation of burns. This study uses the information to identify differences between survivors and nonsurvivors.', 'Fifty-three consecutive patients with major burns were treated using Swan-Ganz-generated data. Additional information was collected, including demographics, intake and output, medications, and arterial blood gas (including calculated oxygen consumption). Statistical analysis incorporated adjustments for autocorrelation.', 'The patients included 38 men and 15 women, averaged 43.7 years of age, and had a mean burn size of 40%. Thirteen patients suffered severe inhalation injury. Data collected hourly over 3 days were collapsed across 6-hour observation periods. Mean values, when plotted across time, discriminated the 37 survivors from the 16 nonsurvivors. Poor response to resuscitation as evidenced by increased use of colloid fluid and cardiotonic drugs plus failure to maximize oxygen consumption were associated with nonsurvival.
Answer: Unsustained or inadequate response to hyperdynamic resuscitation of burns was associated with nonsurvival.

SOLUTION: Do survival in major burn injuries is predicted by early response to Swan-Ganz-guided resuscitation?

PROBLEM: Context: Diabetes mellitus (DM) is a major risk factor for periodontal disease and affects various cellular functions. Periodontal ligament stem cells (PDLSCs) play an important role in periodontal tissue regeneration; however, the effect of hyperglycemia on PDLSCs is unclear. The aim of this study is to investigate whether hyperglycemia affects periodontal tissue regeneration, using human PDLSCs and high-glucose medium as a model of DM.', 'PDLSCs were obtained from healthy adult human mandibular third molars. Cell proliferation, osteoblastic differentiation, and proinflammatory cytokine expression were investigated by culturing PDLSCs in media supplemented with four different glucose concentrations representative of control patients (5.5 mM), patients with postprandial or controlled DM (8.0 mM), and patients with uncontrolled DM (12.0 and 24.0 mM). The molecular effects of hyperglycemia on PDLSC physiology were examined with a focus on the nuclear factor (NF)-(κB signaling pathway. The involvement of NF-κB was investigated with a specific NF-κB inhibitor in PDLSCs under hyperglycemic conditions.', 'High glucose levels inhibited PDLSC proliferation and differentiation into osteoblasts but induced NF-κB activation and subsequent interleukin (IL)-6 and IL-8 expression. Treatment with an NF-κB inhibitor rescued the defects in cell proliferation and osteoblastic differentiation and inhibited the IL-6 expression caused by the high-glucose environment.
Answer: The results of this study demonstrate that hyperglycemia inhibits human PDLSC proliferation and osteoblastic differentiation.

SOLUTION:
Do high Glucose Concentrations Suppress the Proliferation of Human Periodontal Ligament Stem Cells and Their Differentiation Into Osteoblasts?