We investigate consumer preference for online versus offline purchasing of a complex service (home mortgage), across the three stages of purchasing, namely, pre-purchase, purchase, and post-purchase. ...Our analysis of data from 300 consumers shows that (1) the offline channel is generally preferred over the online channel across all the stages, and (2) the channel usage intention in a particular stage is moderated by the consumer's Internet experience. Specifically, in both the pre- and post-purchase stages, the usage intention for the online channel is higher when consumers have more favorable Internet experience. In the purchase stage, consumers prefer the offline channel over the online channel, regardless of their Internet experience. Furthermore, we find that the drivers of channel preference are substantially different across the three buying stages due to (in)congruities between channel benefits desired and channel capabilities offered.
Quaternary‐ammonium‐compounds are potent cationic antimicrobials used in everyday consumer products. Surface‐immobilized, quaternary‐ammonium‐compounds create an antimicrobial contact‐killing ...coating. We describe the preparation of a shape‐adaptive, contact‐killing coating by tethering quaternary‐ammonium‐compounds onto hyperbranched polyurea coatings, able to kill adhering bacteria by partially enveloping them. Even after extensive washing, coatings caused high contact‐killing of Staphylococcus epidermidis, both in culture‐based assays and through confocal‐laser‐scanning‐microscopic examination of the membrane‐damage of adhering bacteria. In culture‐based assays, at a challenge of 1600 CFU/cm2, contact‐killing was >99.99%. The working‐mechanism of dissolved quaternary‐ammonium‐compounds is based on their interdigitation in bacterial membranes, but it is difficult to envisage how immobilized quaternary‐ammonium‐molecules can exert such a mechanism of action. Staphylococcal adhesion forces to hyperbranched quaternary‐ammonium coatings were extremely high, indicating that quaternary‐ammonium‐molecules on hyperbranched polyurea partially envelope adhering bacteria upon contact. These lethally strong adhesion forces upon adhering bacteria then cause removal of membrane lipids and eventually lead to bacterial death.
Shape‐adaptive, hyperbranched polyurea with quaternary ammonium compounds. The preparation of AB2 monomers and the covalently attached hyperbranched polyurea coatings with polyethyleneimine covalently coupled to hyperbranched polyurea coatings. The coatings demonstrate high contact‐killing efficacies toward adhering staphylococci, without any demonstrable leaching of antibacterial compounds.
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Cationic surfaces with alkylated quaternary-ammonium groups kill adhering bacteria upon contact by membrane disruption and are considered increasingly promising as a non-antibiotic ...based way to eradicate bacteria adhering to surfaces. However, reliable in vitro evaluation methods for bacterial contact-killing surfaces do not yet exist. More importantly, results of different evaluation methods are often conflicting. Therefore, we compared five methods to evaluate contact-killing surfaces. To this end, we have copolymerized quaternary-ammonium groups into diurethane dimethacrylate/glycerol dimethacrylate (UDMA/GDMA) and determined contact-killing efficacies against five different Gram-positive and Gram-negative strains. Spray-coating bacteria from an aerosol onto contact-killing surfaces followed by air-drying as well as ASTM E2149-13a (American Society for Testing and Materials) were found unsuitable, while the Petrifilm® system and JIS Z 2801 (Japanese Industrial Standards) were found to be excellent methods to evaluate bacterial contact-killing surfaces. It is recommended however, that these methods be used in combination with a zone of inhibition on agar assay to exclude that leakage of antimicrobials from the material interferes with the contact-killing ability of the surface.
Bacterial adhesion to surfaces of biomaterials implants can be life-threatening. Antimicrobials to treat biomaterial-associated infections often fail due to the bacterial biofilm-mode-of-growth or are ineffective due to antibiotic-resistance of causative organisms. Positively-charged, quaternized surfaces can kill bacteria upon contact and are promising as a non-antibiotic-based treatment of biomaterial-associated infections. Reliable methods to determine efficacies of contact-killing surfaces are lacking, however. Here, we show that three out of five methods compared, including an established ASTM, are unsuitable. Methods found suitable should be used in combination with a zone-of-inhibition-assay to establish absence of antimicrobial leaching, potentially interfering with contact-killing. Identification of suitable assays for evaluating bacterial contact-killing will greatly assist this emerging field as an alternative for antibiotic-based treatment of biomaterial-associated-infections.
No single reliable parameter exists to assess liver graft function of extended criteria donors during ex-vivo normothermic machine perfusion (NMP). The liver maximum capacity (LiMAx) test is a ...clinically validated cytochromal breath test, measuring liver function based on 13CO2 production. As an innovative concept, we aimed to integrate the LiMAx breath test with NMP to assess organ function. Eleven human livers were perfused using NMP. After one hour of stabilization, LiMAx testing was performed. Injury markers (ALT, AST, miR-122, FMN, and Suzuki-score) and lactate clearance were measured and related to LiMAx values. LiMAx values ranged between 111 and 1838 µg/kg/h, and performing consecutive LiMAx tests during longer NMP was feasible. No correlation was found between LiMAx value and miR-122 and FMN levels in the perfusate. However, a significant inverse correlation was found between LiMAx value and histological injury (Suzuki-score, R = - 0.874, P < 0.001), AST (R = - 0.812, P = 0.004) and ALT (R = - 0.687, P = 0.028). Furthermore, a significant correlation was found with lactate clearance (R = 0.683, P = 0.043). We demonstrate, as proof of principle, that liver function during NMP can be quantified using the LiMAx test, illustrating a positive correlation with traditional injury markers. This new breath-test application separates livers with adequate cytochromal liver function from inadequate ones and may support decision-making in the safe utilization of extended criteria donor grafts.
The development, homeostasis, and repair of intrahepatic and extrahepatic bile ducts are thought to involve distinct mechanisms including proliferation and maturation of cholangiocyte and progenitor ...cells. This study aimed to characterize human extrahepatic cholangiocyte organoids (ECO) using canonical Wnt-stimulated culture medium previously developed for intrahepatic cholangiocyte organoids (ICO). Paired ECO and ICO were derived from common bile duct and liver tissue, respectively. Characterization showed both organoid types were highly similar, though some differences in size and gene expression were observed. Both ECO and ICO have cholangiocyte fate differentiation capacity. However, unlike ICO, ECO lack the potential for differentiation towards a hepatocyte-like fate. Importantly, ECO derived from a cystic fibrosis patient showed no CFTR channel activity but normal chloride channel and MDR1 transporter activity. In conclusion, this study shows that ECO and ICO have distinct lineage fate and that ECO provide a competent model to study extrahepatic bile duct diseases like cystic fibrosis.
Liquid biopsy-based biomarkers, such as microRNAs, represent valuable tools for patient management, but often do not make it to integration in the clinic. We aim to explore issues impeding this ...transition, in the setting of germ cell tumors, for which novel biomarkers are needed. We describe a model for identifying and validating clinically relevant microRNAs for germ cell tumor patients, using both in vitro, in vivo (mouse model) and patient-derived data. Initial wide screening of candidate microRNAs is performed, followed by targeted profiling of potentially relevant biomarkers. We demonstrate the relevance of appropriate (negative) controls, experimental conditions (proliferation), and issues related to sample origin (serum, plasma, cerebral spinal fluid) and pre-analytical variables (hemolysis, contaminants, temperature), all of which could interfere with liquid biopsy-based studies and their conclusions. Finally, we show the value of our identification model in a specific scenario, contradicting the presumed role of miR-375 as marker of teratoma histology in liquid biopsy setting. Our findings indicate other putative microRNAs (miR-885-5p, miR-448 and miR-197-3p) fulfilling this clinical need. The identification model is informative to identify the best candidate microRNAs to pursue in a clinical setting.
Purpose
To determine the correlation of preoperative fascia thickness (FT) and intraoperative fascia preservation (FP) with erectile function (EF) after nerve-sparing robot-assisted radical ...prostatectomy (RARP).
Methods
Our analysis included 106 patients, with localized prostate cancer and no erectile dysfunction (ED) before RARP, assessed with preoperative 3 Tesla (3 T) multiparametric magnetic resonance imaging (MRI). FP score was defined as the extent of FP from the base to the apex of the prostate, quantitatively assessed by the surgeon. Median fascia thickness (MFT) per patient was defined as the sum of the median FT of 12 MRI regions. Preserved MFT (pMFT) was the sum of the saved MFT. The percentage of pFMT (ppMFT) was also calculated. Fascia surface (FS) was measured on MRI and it was combined with FP score resulting in preserved FS (pFS) and percentage of pFS (ppFS).
Results
FP score, pMFT, ppMFT, pFS and ppFS were significantly lower (
p
< 0.0001) in patients with ED. In the multivariate regression analysis, lower FP score odds ratio (OR) 0.721,
p
= 0.03 and lower ppMFT (OR 0.001,
p
= 0.027) were independent predictors of ED. ROC analysis showed the highest area under the curve for ppMFT (0.787) and FP score (0.767) followed by pMFT (0.755) and ppFS (0.743).
Conclusions
MRI-determined periprostatic FT combined with intraoperative FP score are correlated to postprostatectomy EF. Based on the hypothesis that a thicker fascia forms a protective layer for the nerves, we recommend assessing FT preoperatively to counsel men for the odds of preserving EF after RARP.
•Intestinal and biliary epithelia were cultured from cystic fibrosis organoids.•Elexacaftor/ivacaftor/tezacaftor rescued chloride transport in both epithelia.•CFTR modulators enhanced bicarbonate ...transport only in intestinal cells.•Biliary cells secrete bicarbonate and chloride via anoctamin-1, independent of CFTR.
In cystic fibrosis (CF), loss of CF transmembrane conductance regulator (CFTR)-dependent bicarbonate secretion precipitates the accumulation of viscous mucus in the lumen of respiratory and gastrointestinal epithelial tissues. We investigated whether the combination of elexacaftor (ELX), ivacaftor (IVA) and tezacaftor (TEZ), apart from its well-documented effect on chloride transport, also restores Phe508del-CFTR-mediated bicarbonate transport.
Epithelial monolayers were cultured from intestinal and biliary (cholangiocyte) organoids of homozygous Phe508del-CFTR patients and controls. Transcriptome sequencing was performed, and bicarbonate and chloride transport were assessed in the presence or absence of ELX/IVA/TEZ, using the intestinal current measurement technique.
ELX/IVA/TEZ markedly enhanced bicarbonate and chloride transport across intestinal epithelium. In biliary epithelium, it failed to enhance CFTR-mediated bicarbonate transport but effectively rescued CFTR-mediated chloride transport, known to be requisite for bicarbonate secretion through the chloride-bicarbonate exchanger AE2 (SLC4A2), which was highly expressed by cholangiocytes. Biliary but not intestinal epithelial cells expressed an alternative anion channel, anoctamin-1/TMEM16A (ANO1), and secreted bicarbonate and chloride upon purinergic receptor stimulation.
ELX/IVA/TEZ has the potential to restore both chloride and bicarbonate secretion across CF intestinal and biliary epithelia and may counter luminal hyper-acidification in these tissues.
Graphical abstract
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Delayed graft function (DGF), a common complication after transplantation of deceased donor kidneys, affects both short- and long-term outcomes. Currently available biomarkers during graft ...preservation lack sensitivity in predicting risk for DGF. The aim of this study is to identify cell-free micro ribonucleic acid (miRNA) biomarkers in graft preservation fluid predictive of DGF after kidney transplantation.
Vascular bed preservation fluid was collected from 48 kidney grafts from donation after circulatory death (DCD) or donation after brain death (DBD) donors. miRNA profiles were determined by polymerase chain reaction (PCR) array (n = 8) and validated by reverse transcription and quantitative PCR (n = 40). Graft function posttransplantation was defined as immediate good function (IF) or DGF.
A total of 223 miRNAs fulfilled the preset parameters (Ct < 40 in 3 or more samples) and were included in the analysis. Thirty-two miRNAs were significantly different between DGF and IF kidney grafts (P < 0.05) but, after correction for multiple testing, only miR-505-3p remained significant. The significant association of high miR-505-3p levels with DGF was confirmed in an independent validation cohort using conventional reverse transcription and quantitative PCR detection. Multivariate analyses showed miR-505-3p as an independent predictor for DGF (odds ratio, 1.12; P = 0.028). If stratified for donor type, miR-505-3p levels remained significantly different between IF and DGF in DCD grafts (P < 0.01), but not in DBD grafts. Receiver operating characteristic curve analysis showed a high sensitivity and specificity (area under the curve, 0.833).
In DCD grafts, high levels of miR-505-3p in preservation fluid are associated with increased risk of DGF after kidney transplantation. Further study is required to confirm the utility of cell-free miR-505-3p as prognostic biomarker for DGF.
The superior long-term survival of kidneys from living donors (LDs) compared with kidneys from donation-after-brain-death (DBD) and donation-after-cardiac-death (DCD) donors is now well established. ...However, comparative studies on transcriptional changes that occur at organ retrieval and during and after cold ischemia (CI) are sparse.
Using a rat model, we used qRT-PCR to examine expression levels of inflammatory, cytoprotective, and injury genes at different time points after organ retrieval. Cleaved caspase-3 was used to evaluate early apoptosis in DCD and DBD kidneys.
Immediately after retrieval, we found massive up-regulation of proinflammatory genes interleukin-1β, interleukin-6, tumor necrosis factor-α, monocyte chemotactic protein-1, P-selectin, and E-selectin in DBD compared with LD and DCD kidneys. A significant increase in the expression of injury markers Kim-1, p21, and the cytoprotective gene heme oxygenase-1 accompanied this. Bax was increased in DCD kidneys, and Bcl-2 was decreased in DBD kidneys. After 2 hr of CI in the LD group and 18 hr in the DBD and DCD groups, gene expression levels were similar to those found after retrieval. During 18 hr of cold storage, expression levels of these genes did not change. In DCD and DBD kidneys, early apoptosis increased after CI.
The gene expression profile in DBD kidneys represents an inflammatory and injury response to brain death. In contrast, DCD kidneys show only mild up-regulation of inflammatory and injury genes. These results may imply why delayed graft function in DCD kidneys does not have the deleterious effect it has on DBD kidneys.
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