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: The failure of in utero transplantation in immune-competent recipients suggests the existence of a fetal immune barrier. The importance of donor major histocompatibility complex (MHC) class I expression in the induction of prenatal tolerance remains undefined. We hypothesized that donor cell MHC class I expression facilitates engraftment in prenatal allogeneic recipients rather than promoting immune rejection.', 'B6.Ly5.2 (class I(+)) or B6.TAP(-/-) (class I(-)) murine fetal liver cells were transplanted into age-matched allogeneic fetal recipients. Survival to weaning and subsequent growth was assessed. Engraftment rates and peripheral blood chimerism levels were measured serially.', 'The presence or absence of class I expression did not affect survival or growth of recipients and no graft-vs-host disease developed. Allogeneic recipients of B6.Ly5.2 cells exhibited significantly higher levels of donor hematopoietic chimerism when compared to recipients of B6.TAP(-/-) cells (27% + 10% vs 11% + 8%; P = .004) that deteriorated further over time.
Answer: Donor class I MHC antigen expression is essential for stable long-term engraftment and maintenance of donor-specific tolerance. Further studies are needed to better characterize the role of the fetal innate immune system in prenatal allotransplantation.

SOLUTION: Does donor major histocompatibility complex class I expression determine the outcome of prenatal transplantation?

PROBLEM: Context: To investigate the possibility of using a modified reverse transfer function (RTF) measurement intraoperatively during surgery of a new transcutaneous bone conduction hearing implant to evaluate the status of the device.', 'Tests were performed on a cadaver skull (preclinically) and two conductive hearing loss patients implanted with a new transcutaneous bone conduction implant. During intraoperative activation, the RTF was measured using a microphone attached perpendicularly and directly to the skin in the middle section of the forehead.', 'The RTF could be measured for all frequencies from 500 to 6, 000 Hz.
Answer: The usage of an intraoperative RTF measurement may be a good method to verify the mechanical coupling of the bone conduction floating mass transducer and to test the functional integrity of the implant in an objective way.

SOLUTION: Do intraoperative measurement for a new transcutaneous bone conduction hearing implant?

PROBLEM: Context: Historically, fever, pneumonia, and sepsis after trauma are ascribed to pain and poor pulmonary toilet. No evidence supports that assertion however, and no known biologic mechanisms link injury to infection. Our studies show that injured tissues release mitochondria (MT). Mitochondrial damage-associated molecular patterns (mtDAMPs) however can mimic bacterial pathogen-associated danger molecules and attract neutrophils (PMN). We hypothesized that mtDAMPs from traumatized tissue divert neutrophils from the lung, causing susceptibility to infection.', 'Anesthetized rats (6-10 per group) underwent pulmonary contusion (PC) by chest percussion. When modeling traumatic MT release, some rats had MT isolated from the liver (equal to 5% liver necrosis) injected intraperitoneally (IPMT). Negative controls had PC plus buffer intraperitoneally. Positive controls underwent PC plus cecal ligation and puncture. At 16 hours, bronchoalveolar and peritoneal lavages were performed. Bronchoalveolar lavage fluid (BALF) and peritoneal lavage fluid were assayed for PMN count, albumin, interleukin β, (IL-β), and CINC-1. Assays were normalized to blood urea nitrogen to calculate absolute concentrations.', 'PC caused alveolar IL-1β and CINC production and a 34-fold increase in BALF neutrophils. As expected, IPMT increased peritoneal IL-1β and CINC and attracted PMN to the abdomen. However, remarkably, IPMT after PC attenuated BALF cytokine accumulation and decreased BALF PMN. Cecal ligation and puncture had no direct effect on BALF PMNs but, like IPMT, blunted BALF leukocytosis after PC.
Answer: Rather than acting as a "second hit" to enhance PMN-mediated lung injury, mtDAMPs from trauma and pathogen-associated danger molecules from peritoneal infection diminish PMN accumulation in a contused lung. This may make the lung susceptible to pneumonia. This paradigm provides a novel mechanistic model of the relationship among blunt tissue trauma, systemic inflammation, and pneumonia that can be studied to improve trauma outcomes.

SOLUTION:
Do mitochondrial damage-associated molecular patterns released by abdominal trauma suppress pulmonary immune responses?