Biomarkers of Early Liver Graft Damage in Circulatory Death and Brain Death Donors: A Propensity Score Matching Analysis.

BACKGROUND: Donation after circulatory death (DCD) is related to a warm ischemia time and more complications compared with traditional donors (donation after brain death [DBD]). METHODS: This study included biopsy samples retrospectively collected from November 2014 to December 2018 to compare histologic and biological markers of DCD and DBD liver grafts. The analysis includes marker of early apoptosis (p21), senescence (telomerase reverse transcriptase [TERT]), cell damage (caspase-3 active), endothelial damage (vascular endothelial growth factor), stem cell (CD90), hypoxia (HIF1A), inflammatory activation (COX-2), and cross-organ allograft rejection (CD44). A propensity score matching (PSM) was used to match patients receiving DCD livers to those receiving DBD livers. We analyzed the immunohistochemical initial liver damage-related warm ischemia time. RESULTS: Positive staining expression of liver damage biomarkers (COX-2, CD44, TERT, HIF1A, and CD90) was found, but no significant differences were found between DCD and DBD and with ischemic cholangiopathy. After PSM, there was a significant relationship between CD90 and male donors (odds ratio [OR], 0.26; 95% confidence interval [CI], 0.07-0.91), TERT with donor sodium (OR, 1.11; 95% CI, 1.02-1.2), HIF1A with steatosis (OR, 0.33; 95% CI, 0.13-0.83), and CD44 with donor vasoactive drugs (OR, 0.36; 95% CI, 0.13-1) and glutamic oxaloacetic transaminase 1 week increase (OR, 1.01; 95% CI, 1-1.03). CONCLUSIONS: DCD immunohistochemical initial liver damage was found to behave similarly to DBD. The increase in complications and cholangiopathy associated with warm ischemia could be related to a different later phenomenon.

Wheezing Sound Separation Based on Informed Inter-Segment Non-Negative Matrix Partial Co-Factorization.

Wheezing reveals important cues that can be useful in alerting about respiratory disorders, such as Chronic Obstructive Pulmonary Disease. Early detection of wheezing through auscultation will allow the physician to be aware of the existence of the respiratory disorder in its early stage, thus minimizing the damage the disorder can cause to the subject, especially in low-income and middle-income countries. The proposed method presents an extended version of Non-negative Matrix Partial Co-Factorization (NMPCF) that eliminates most of the acoustic interference caused by normal respiratory sounds while preserving the wheezing content needed by the physician to make a reliable diagnosis of the subject's airway status. This extension, called Informed Inter-Segment NMPCF (IIS-NMPCF), attempts to overcome the drawback of the conventional NMPCF that treats all segments of the spectrogram equally, adding greater importance for signal reconstruction of repetitive sound events to those segments where wheezing sounds have not been detected. Specifically, IIS-NMPCF is based on a bases sharing process in which inter-segment information, informed by a wheezing detection system, is incorporated into the factorization to reconstruct a more accurate modelling of normal respiratory sounds. Results demonstrate the significant improvement obtained in the wheezing sound quality by IIS-NMPCF compared to the conventional NMPCF for all the Signal-to-Noise Ratio (SNR) scenarios evaluated, specifically, an SDR, SIR and SAR improvement equals 5.8 dB, 4.9 dB and 7.5 dB evaluating a noisy scenario with SNR = -5 dB.