In this task, you're given a paragraph from the research paper and your task is to generate a suitable title for the research paper based on the given paper. Under 100 words is a good title length.

[Q]: Background: Proenkephalin (PENK) has been suggested as a novel biomarker for kidney function. We investigated the diagnostic and prognostic utility of plasma PENK in comparison with neutrophil gelatinase-associated lipocalin (NGAL) and estimated glomerular filtration rates (eGFR) in septic patients. Methods: A total of 167 septic patients were enrolled: 99 with sepsis, 37 with septic shock, and 31 with suspected sepsis. PENK and NGAL concentrations were measured and GFR was estimated by using the isotope dilution mass spectrometry traceable-Modification of Diet in Renal Disease (MDRD) Study and three Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations: CKD-EPICr, CDK-EPICysC, and CKD-EPICr-CysC. The PENK, NGAL, and eGFR results were compared according to sepsis severity, presence or absence of acute kidney injury (AKI), and clinical outcomes. Results: The PENK, NGAL, and eGFR results were significantly associated with sepsis severity and differed significantly between patients with and without AKI only in the sepsis group (all P < 0.05). PENK was superior to NGAL in predicting AKI (P = 0.022) and renal replacement therapy (RRT) (P = 0.0085). Regardless of the variable GFR category by the different eGFR equations, PENK showed constant and significant associations with all eGFR equations. Unlike NGAL, PENK was not influenced by inflammation and predicted the 30day mortality. Conclusions: PENK is a highly sensitive and objective biomarker of AKI and RRT and is useful for prognosis prediction in septic patients. With its diagnostic robustness and predictive power for survival, PENK constitutes a promising biomarker in critical care settings including sepsis.
[A]: Original Article Clinical Chemistry Proenkephalin, Neutrophil Gelatinase-Associated Lipocalin, and Estimated Glomerular Filtration Rates in Patients With Sepsis


[Q]: The circRNA is a newly defined noncoding RNA and characterized by its unique splicing reactions to form circles. However, the function of circRNAs during viral infection remains largely unknown. In this study, the circRNA expression profile during porcine endemic diarrhea virus (PEDV) infection in IPEC-J2 cell line was investigated using the next-generation sequencing technology. A total of 26670 circRNA candidates were identified. The functional annotation analysis revealed that the parent genes of differentially expressed circRNAs might be associated with host response to PEDV infection. Further analysis verified the existence of eight selected circRNAs and confirmed that PEDV infection alerted the expression patterns of circRNAs and their linear parent genes in IPEC-J2 cell line. The circRNA-miRNA interaction network was also constructed to elucidate their potential targets. Our results provided not only the first large-scale profile analysis of circRNAs associated with PEDV infection but also a novel direction to elucidate host-PEDV interactions.
[A]: Profile analysis of circRNAs induced by porcine endemic diarrhea virus infection in porcine intestinal epithelial cells


[Q]: Viral infections of the central nervous system (CNS) necessitate rapid, yet tightly controlled responses to contain viral spread while limiting tissue damage. All CNS resident cell types are equipped with pattern recognition receptors (PRRs) to respond to viruses. The resulting activation of IFN-α/β, proinflammatory cytokines and chemokines is dependent on the virus replication strategy, tropism and PRR distribution. Although IFN-α/β induced antiviral mediators are essential to restrict initial viral spread, adaptive immunity promoted by chemokines, cytokines and metalloproteinases is equally critical in lowering viral burden. Recognition of viral antigen presented by MHC molecules is critical for T cell retention and function. Non lytic clearance mechanisms mediated by IFN-γ and antibodies prevail in providing protection. Targeted intervention can be achieved by PRR stimulation, chemokine-receptor blockade and immune modulation of T cell function. However, due to the extensive positive and negative feedback signaling cascades linking innate and adaptive immune responses, enhanced anti-viral functions will have to be counterbalanced to avoid pathology.
[A]:
Neuroimmunology of central nervous system viral infections: the cells, molecules and mechanisms involved