Histidine-rich glycoprotein as a novel predictive biomarker of postoperative complications in intensive care unit patients: a prospective observational study

Background Decrease in histidine-rich glycoprotein (HRG) was reported as a cause of dysregulation of the coagulation-fibrinolysis and immune systems, leading to multi-organ failure, and it may be a biomarker for sepsis, ventilator-associated pneumonia, preeclampsia, and coronavirus disease 2019. However, the usefulness of HRG in perioperative management remains unclear. This study aimed to assess the usefulness of HRG as a biomarker for predicting postoperative complications. Methods This was a single-center, prospective, observational study of 150 adult patients who were admitted to the intensive care unit after surgery. Postoperative complications were defined as those having a grade II or higher in the Clavien-Dindo classification, occurring within 7 days after surgery. The primary outcome was HRG levels in the patients with and without postoperative complications. The secondary outcome was the ability of HRG, white blood cell, C-reactive protein, procalcitonin, and presepsin to predict postoperative complications. Data are presented as number and median (interquartile range). Results The incidence of postoperative complications was 40%. The HRG levels on postoperative day 1 were significantly lower in patients who developed postoperative complications (n = 60; 21.50 [18.12-25.74] mu g/mL) than in those who did not develop postoperative complications (n = 90; 25.46 [21.05-31.63] mu g/mL). The Harrell C-index scores for postoperative complications were HRG, 0.65; white blood cell, 0.50; C-reactive protein, 0.59; procalcitonin, 0.73; and presepsin, 0.73. HRG was independent predictor of postoperative complications when adjusted for age, the presence of preoperative cardiovascular comorbidities, American Society of Anesthesiologists Physical Status Classification, operative time, and the volume of intraoperative bleeding (adjusted hazard ratio = 0.94; 95% confidence interval, 0.90-0.99). Conclusions The HRG levels on postoperative day 1 could predict postoperative complications. Hence, HRG may be a useful biomarker for predicting postoperative complications

Ionic liquids enable accurate chromatographic analysis of polyelectrolytes

The molecular weight distribution of polyelectrolytes was determined with high performance liquid chromatography using ionic liquids as eluents, because the electrostatic repulsion among polyelectrolytes was entirely suppressed in it. A mixed sample of polycation and polyanion was also analysed to detect them independently. © The Royal Society of Chemistry.Embargo Period 12 month

Renaturation of cytochrome C dissolved in polar phosphonate-type ionic liquids using highly polar zwitterions

We present a method for the renaturation of denatured cytochrome c in a phosphonate-type ionic liquid with the addition of a suitable zwitterion and a small amount of water. The polarity of zwitterions was found to be a critical property for the renaturation of cytochrome c. The renatured cytochrome c was reduced by the addition of sodium dithionite, suggesting that the renatured cytochrome c retains its redox ability. © 2017 The Chemical Society of Japan

1H NMR Analysis of cellulose in ionic liquids

[email protected] NMR spectroscopy of cellulose in a non-deuterated polar ionic liquid (IL) was carried out to analyze specific interaction between cellulose and ILs. We applied a polar IL, 1,3-dimethylimidazolium methyl methylphosphonate, as a cellulose solvent for 1H NMR spectroscopy. To prevent vanishing of the signals of hydroxyl groups (C-OHs) by hydrogen-deuterium exchange, a non-deuterated IL was utilized, and both signals for C-OHs and backbone protons were successfully detected with the aid of the no-deuterium NMR technique and a solvent suppression technique. It was confirmed that C-OHs interacted with ILs more strongly, rather than backbone protons. Furthermore, the signals of the C-OHs at 2-, 3-, and 6-position were independently observed. A strong interaction between C-OH at the 6-position and ILs was confirmed to be a key step for dissolution of cellulose. © 2014 Springer Science+Business Media Dordrecht.Embargo Period 12 month

Direct HPILC Analysis on Cellulose Depolymerisation in Ionic Liquids

Changes of average molecular weight and molecular weight distribution of cellulose in a polar ionic liquid (IL) were analysed with high performance liquid chromatography using a polar IL as an eluent (HPILC). 1-Ethyl-3-methylimidazolium methylphosphonate was used as the polar IL. As a model of partly depolymerised cellulose, a mixed sample composed of cellulose and cello-oligosaccharides (glucose, cellobiose, cellotetraose, and cellohexaose) was evaluated to test the resolution of the HPILC. In the resulting chromatograms, the corresponding peaks for each saccharide were found. Hydrolysed cellulose catalysed by a cellulase mixture in water was then prepared and dried. Then, this was dissolved in the polar IL to analyse its molecular weight distribution. The molecular weight distribution changed depending on the enzymatic reaction time. The peak for cellulose was found to decrease with the increase of the peak for cellobiose, and subsequently the peak for cellobiose decreased with the increase of that for glucose. In addition, cellulose oligomers except for cellobiose were scarcely observed, showing the catalytic feature of cellulase. Depolymerisation of cellulose in the polar IL was also carried out using ultrasonication. The peak for cellulose in the HPILC profiles shifted to a higher retention volume side and broadened with the sonication time, strongly suggesting random depolymerisation of cellulose. Thus, HPILC was confirmed to be effective for the dynamic analysis of cellulose depolymerisation. © The Royal Society of Chemistry 2013.Embargo Period 12 month

Molecular weight distributions of polysaccharides and lignin extracted from plant biomass with a polar ionic liquid analysed without a derivatisation process

Polysaccharides and lignin, extracted from wheat bran with 1-ethyl-3-methylimidazolium methylphosphonate, were directly analysed with high-performance liquid chromatography with the aid of ionic liquid as an eluent (HPILC). Polysaccharides and lignin were clearly detected independently with the use of both a refractive index detector and UV detector. Polysaccharides with low molecular weights were obtained at 25 °C in 2 h with an extraction yield of only 4%. High molecular weight polysaccharides were extracted with a yield of 26% at 120 °C and selective extraction of high MW polysaccharides was succeeded with pretreatment at low temperature. Furthermore, a similar extraction was carried out for wood biomass. Characteristics of pine and oak were observed in the molecular weight distributions of the extracted polysaccharides and lignin. We also analysed the extracts from different parts of Prunus × yedoensis \u27Somei-yoshino\u27. The average molecular weight of polysaccharides from its leaves was determined to be lower than that of its twigs. The present HPILC method has potential to rapidly and easily analyse molecular weight distributions of components of plants. This journal is © The Royal Society of Chemistry.Embargo Period 12 month

1H NMR Evaluation of Polar and Nondeuterated Ionic Liquids for Selective Extraction of Cellulose and Xylan from Wheat Bran

Cellulose and xylan, extracted from wheat bran with polar ionic liquids (ILs), were quantified using 1H NMR spectroscopy. Both No-D NMR and solvent suppression techniques were applied to realize direct analysis of extracts in nondeuterated ILs. As models of extracts, mixtures of cellulose and xylan dissolved in ILs were measured with 1H NMR spectroscopy. There was a linear relation between mixing ratio and specific peak area of each polysaccharide. Extracts from bran in ILs were analyzed with the obtained calibration curve. This NMR analysis was confirmed to be applicable to three representative ILs used for extraction of polysaccharides. A relation between extracted amount and extraction conditions was obtained. © 2014 American Chemical Society.Embargo Period 12 month

Consistently low levels of histidine-rich glycoprotein as a new prognostic biomarker for sepsis: A multicenter prospective observational study

Background Few sepsis biomarkers accurately predict severity and mortality. Previously, we had reported that first-day histidine-rich glycoprotein (HRG) levels were significantly lower in patients with sepsis and were associated with mortality. Since the time trends of HRG are unknown, this study focused on the time course of HRG in patients with sepsis and evaluated the differences between survivors and non-survivors. Methods A multicenter prospective observational study was conducted involving 200 patients with sepsis in 16 Japanese hospitals. Blood samples were collected on days 1, 3, 5, and 7, and 28-day mortality was used for survival analysis. Plasma HRG levels were determined using a modified quantitative sandwich enzyme-linked immunosorbent assay. Results First-day HRG levels in non-survivors were significantly lower than those in survivors (mean, 15.7 [95% confidence interval (CI), 13.4-18.1] vs 20.7 [19.5-21.9] mu g/mL; P = 0.006). Although there was no time x survivors/non-survivors interaction in the time courses of HRG (P = 0.34), the main effect of generalized linear mixed models was significant (P Conclusions HRG levels in non-survivors were consistently lower than those in survivors during the first seven days of sepsis. Repeatedly measured HRG levels were significantly associated with mortality. Furthermore, the predictive power of HRG for mortality may be superior to that of other singular biomarkers, including presepsin, procalcitonin, and C-reactive protein