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 ability of Yersinia pestis to form a biofilm is an important characteristic in flea transmission of this pathogen. Y. pestis laterally acquired two plasmids (pPCP1and pMT1) and the ability to form biofilms when it evolved from Yersinia pseudotuberculosis. Small regulatory RNAs (sRNAs) are thought to play a crucial role in the processes of biofilm formation and pathogenesis.', 'A pPCP1-derived sRNA HmsA (also known as sR084) was found to contribute to the enhanced biofilm formation phenotype of Y. pestis. The concentration of c-di-GMP was significantly reduced upon deletion of the hmsA gene in Y. pestis. The abundance of mRNA transcripts determining exopolysaccharide production, crucial for biofilm formation, was measured by primer extension, RT-PCR and lacZ transcriptional fusion assays in the wild-type and hmsA mutant strains. HmsA positively regulated biofilm synthesis-associated genes (hmsHFRS, hmsT and hmsCDE), but had no regulatory effect on the biofilm degradation-associated gene hmsP. Interestingly, the recently identified biofilm activator sRNA, HmsB, was rapidly degraded in the hmsA deletion mutant. Two genes (rovM and rovA) functioning as biofilm regulators were also found to be regulated by HmsA, whose regulatory effects were consistent with the HmsA-mediated biofilm phenotype.

Answer: Does plasmid pPCP1-derived sRNA HmsA promote biofilm formation of Yersinia pestis?


Question: Post-hemorrhagic shock mesenteric lymph (PHSML) has been linked with neutrophil (PMN) priming, endothelial cell (EC) activation, and acute lung injury (ALI) in rodent models. We have previously identified the lipid fraction of PHSML as containing the causative agent(s). Due to the lesson learned from the rodent gut bacterial translocation experience, we sought to confirm this phenomenon using a large animal model; hypothesizing that lymph collected from the porcine gut following ischemia/reperfusion (I/R) would cause PMN priming.', 'Mesenteric lymph was collected from adult pigs before, during, and for 2 hours after non-lethal hemorrhagic shock (mean arterial pressure = 30 mm Hg x 45 minutes). Whole lymph and the extracted lipid fractions of the lymph were then added to isolated human and porcine PMNs and superoxide production was measured by cytochrome C reduction.', 'Hemorrhagic shock profoundly affected mesenteric lymph flow from baseline (pre-shock) flow rates of 75.63 +/- 8.86 mL/hr to 49.38 +/- 5.76 mL/hr during shock and increasing to 253.38 +/- 27.62 mL/hr after 2 hours of resuscitation. Human PMNs exposed to both whole lymph (PHSML) and its extracted lipids (PHSML Lipid) collected 2 hours after shock exhibited more than a two-fold increase in superoxide release upon activation compared with pre-shock samples: PHSML- 6.27 +/- 0.83 versus 2.56 +/- 0.60 nmolO2(-)/ 3.75 cells/mL/min, respectively (p = 0.007), PHSML Lipid- 4.93 +/- 0.34 versus 2.49 +/- 0.11 nmolO2(-)/ 3.75 cells/mL/min (p < 0.001). Similarly, porcine PMNs exhibited close to a two-fold activation when exposed to the lymph and lipid fraction: PHSML- 4.51 +/- 0.42 versus 1.06 +/- 0.28 nmolO2(-)/ 3.75 cells/mL/min (p = 0.008), PHSML Lipid-4.80 +/- 0.81 versus 1.55 +/- 0.23 nmolO2(-)/ 3.75 cells/mL/min (p = 0.002).

Answer: Does systemic neutrophil priming by lipid mediators in post-shock mesenteric lymph exist across species?


Question: Leaks of the blood-brain barrier can be detected on postcontrast-enhanced T1-weighted MRIs. Although early disruptions of the blood-brain barrier appear to be an important risk factor for tissue plasminogen activator-related hemorrhages in rodents, little is known about their incidence and consequences in human stroke.', "This is a retrospective analysis of a prospectively collected stroke database over the past 6 years. In 52 patients, multimodal MRI (including diffusion-weighted, perfusion-weighted, and postcontrast-enhanced T1-weighted MRI to detect blood-brain barrier changes) had been performed immediately before systemic thrombolysis and in 48 patients within a median of 30 minutes (interquartile range: 30 to 60 minutes) after recombinant tissue plasminogen activator treatment. The incidence of symptomatic hemorrhage (SICH), defined as any parenchymal hemorrhage leading to deterioration in the patient's clinical condition, was related to several clinical and imaging variables, including early blood-brain barrier changes.", 'Overall, SICH was detected in 9 (9%) patients and among these, 2 died. Although no blood-brain barrier changes were detectable before thrombolysis, 3 of 48 patients (6.25%) had a parenchymal gadolinium enhancement in the areas of initial infarction after tissue plasminogen activator treatment. All 3 patients developed SICHs at sites corresponding to the areas of enhancement. The presence of a parenchymal enhancement was significantly associated with SICH (P<0.01), whereas other clinical and imaging variables did not predict SICH in this series.

Answer:
Does early disruption of the blood-brain barrier after thrombolytic therapy predict hemorrhage in patients with acute stroke?