Association of FIB-4 index and clinical outcomes in critically ill patients with acute kidney injury: a cohort study.

BACKGROUND: The relationship between fibrosis-4 (FIB-4) index and clinical outcomes in patients with acute kidney injury (AKI) is unclear. We aimed to investigate the association between FIB-4 index and all-cause mortality in critically ill patients with AKI. METHODS: We used data from the Multiparameter Intelligent Monitoring in Intensive Care III (MIMIC-III) database (v1.4). The FIB-4 score was calculated using the existing formulas. logistic regression model, and Cox proportional hazards model were used to assessed the relationship between the FIB-4 index and in-hospital,28-day and 90-day mortality, respectively. RESULTS: A total of 3592 patients with AKI included in the data analysis. 395 (10.99%) patients died during hospitalization and 458 (12.74%) patients died in 28-day. During the 90-day follow-up, 893 (22.54%) patients were dead. An elevated FIB-4 value was significantly associated with increased in-hospital mortality when used as a continuous variable (odds ratio [OR] 1.183, 95% confidence interval [CI] 1.072-1.305, P = 0.002) and as a quartile variable (OR of Q2 to Q4 1.216-1.744, with Q1 as reference). FIB-4 was positively associated with 28-day mortality of AKI patients with hazard ratio (HR) of 1.097 (95% CI 1.008, 1.194) and 1.098 (95% 1.032, 1.167) for 90-day mortality, respectively. CONCLUSION: This study demonstrated the FIB-4 index is associated with clinical outcomes in critically ill patients with acute kidney injury.

Functional endothelial cells derived from embryonic stem cells labeled with HIV transactivator peptide-conjugated superparamagnetic nanoparticles.

BACKGROUND: The development of regenerative therapies using derivatives of embryonic stem (ES) cells would be facilitated by a non-invasive method to monitor transplanted cells in vivo, for example, magnetic resonance imaging of cells labeled with superparamagnetic iron oxide (SPIO) nanoparticles. Although ES cells have been labeled with SPIO particles, the potential adverse effects of the label have not been fully examined. The objective of this study was to determine whether SPIO labeling affects murine ES cell viability, proliferation, or ability to differentiate into functional endothelial cells (ECs). METHODS: Cross-linked iron oxide (CLIO, an SPIO) was conjugated with human immunodeficiency virus transactivator of transcription (HIV-Tat) peptides, and murine ES cells were labeled with either CLIO-Tat, CLIO, or HIV-Tat. After labeling, ES cells were cultured for 4 days and Flk-1(+) ES cells identified and sorted by immunocytochemistry and fluorescence activated cell sorting (FACS). Flk-1(+) cells were replated on fibronectin-coated dishes, and ECs were obtained by culturing these for 4 weeks in endothelial cell growth medium supplemented with vascular endothelial growth factor (VEGF). ES cell viability was determined using trypan blue exclusion, and the proportion of SPIO(+) cells was evaluated using Prussian blue staining and transmission electron microscopy. After differentiation, the behavior and phenotype of ECs were analyzed by reverse transcription-polymerase chain reaction, flow cytometry, immunocytochemistry, DiI-labeled acetylated low-density lipoprotein (AcLDL) uptake, and Matrigel tube formation assay. RESULTS: CLIO-Tat was a highly effective label for ES cells, with > 96% of cells incorporating the particles, and it did not alter the viability of the labeled cells. ECs derived from CLIO-Tat(+) ES cells were very similar to murine aortic ECs in their morphology, expression of endothelial cell markers, ability to form vascular-like channels, and scavenging of AcLDL from the culture medium. CONCLUSIONS: CLIO-Tat is a highly effective label for ES cells and does not adversely affect cell viability, differentiation, or behavior. CLIO-Tat could be a useful marker for the non-invasive monitoring of transplanted stem cells.