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Background: Neutrophil gelatinase-associated lipocalin (NGAL) is proposed as an early marker of kidney injury. We report the association of urinary NGAL with indexes of intraoperative renal hypoperfusion (cardiopulmonary bypass time and aortic cross-clamp time) and acute kidney injury (AKI) after adult cardiac surgery. Study Design: Diagnostic test accuracy. Setting& Participants: Adult cardiac surgical patients (n = 426) in a single center from 2004 to 2006. Index Test: Urinary NGAL immediately and 3, 18, and 24 hours after cardiac surgery, using an enzyme-linked immunosorbent assay. Reference Test or Outcome: Serum creatinine-based definition for AKI (increase in serum creatinine from preoperative values by >50% or >0.3 mg/dL within 48 hours). Results: Mean urinary NGAL level was 165 +/- 663 (SD) ng/mL preoperatively, peaked immediately after cardiac surgery at 1,490 +/- 102 ng/mL, and remained significantly higher 3, 18, and 24 hours after surgery. 85 patients (20%) developed AKI. Areas under the receiver operating characteristic curve for urinary NGAL immediately after and 3, 18, and 24 hours later as a predictor for AKI were 0.573 (95% confidence interval [CI], 0.506 to 0.640), 0.603 (95% CI, 0.533 to 0.674), 0.611 (95% CI, 0.544 to 0.679), and 0.584 (95% CI, 0.510 to 0.657), respectively. Urinary NGAL, but not serum creatinine, level correlated significantly with cardiopulmonary bypass and aortic cross-clamp times. Areas under receiver operating characteristic curves for cardiopulmonary bypass time and aortic cross-clamp time to predict AKI were 0.592 (95% CI, 0.518 to 0.666) and 0.593 (95% CI, 0.523 to 0.665), respectively. Limitations: Limited sensitivity of changes in serum creatinine levels for kidney injury. Conclusions: Urinary NGAL has limited diagnostic accuracy to predict AKI defined by change in serum creatinine after cardiac surgery. [ABSTRACT FROM AUTHOR]

In this paper an XRD, FTIR and TPD investigation of NO2 surface adsorption sites of δ, γ Al2O3 and barium supported δ, γ Al2O3 is reported. Aim of this study is to bring additional light on the surface structures involved in NOx adsorption. Two samples of barium supported aluminas have been prepared and aged at 800 °C. These samples were characterised in comparison with the relative alumina support. The XRD characterisation of these samples shows the presence of barium carbonate and barium aluminate supported on alumina. The comparison of the FTIR spectra, before and after NO2 adsorption, has revealed the formation, upon NO2 contact, of a complex variety of nitrate and nitrite groups. The thermal desorption of nitrate and nitrite species has been simultaneously studied by means of FTIR spectroscopy and by TPD technique. By comparing the structural, adsorptive and spectroscopic results obtained on alumina and on barium supported alumina samples, a hypothesis on the basic sites active in NO2 adsorption and of the possible decomposition paths induced by thermal heating are proposed. [ABSTRACT FROM AUTHOR]

In this paper an XRD, FTIR and TPD investigation of NO2 surface adsorption sites of δ, γ Al2O3 and barium supported δ, γ Al2O3 is reported. Aim of this study is to bring additional light on the surface structures involved in NOx adsorption. Two samples of barium supported aluminas have been prepared and aged at 800 °C. These samples were characterised in comparison with the relative alumina support. The XRD characterisation of these samples shows the presence of barium carbonate and barium aluminate supported on alumina. The comparison of the FTIR spectra, before and after NO2 adsorption, has revealed the formation, upon NO2 contact, of a complex variety of nitrate and nitrite groups. The thermal desorption of nitrate and nitrite species has been simultaneously studied by means of FTIR spectroscopy and by TPD technique. By comparing the structural, adsorptive and spectroscopic results obtained on alumina and on barium supported alumina samples, a hypothesis on the basic sites active in NO2 adsorption and of the possible decomposition paths induced by thermal heating are proposed. [ABSTRACT FROM AUTHOR]

Adsorption of CO-, NO- and CO/NO-containing mixtures was investigated by in situ IR spectroscopy under flow conditions over Pd/δ-Al2O3 and Pd/Ce0.6Zr0.4O2/δ-Al2O3. The attention is focused on the effects of Ce0.6Zr0.4O2 addition to Pd/Al2O3 on the catalytic properties and reaction intermediates. Linearly bonded and bridged CO species adsorbed on palladium were clearly identified on Pd/Al2O3 while CO adsorption is inhibited under reaction conditions in the presence of Ce0.6Zr0.4O2. Addition of Ce0.6Zr0.4O2 affects the nature of the Pd sites by stabilizing oxidized dispersed Pd species. Evidence is obtained that the presence of the Ce0.6Zr0.4O2 solid solution modifies the adsorption properties of the supported Pd species and promotes the reduction of NO below 500 K via an alternative mechanism. This presumably involves reactive oxygen species at the Pd–Ce0.6Zr0.4O2 interface generated by the redox Ce4+/Ce3+ couple. [Copyright &y& Elsevier]

Objective: The purpose of this study was to compare urinary neutrophil gelatinase-associated lipocalin (NGAL) levels in off-pump and on-pump coronary artery bypass graft (CABG) surgery., Design: A matched cohort study., Setting: A tertiary university hospital., Participants: Thirty adult patients undergoing CABG surgery without cardiopulmonary bypass (off-pump) matched to 30 patients with on-pump CABG surgery by age, preoperative serum creatinine, Parsonnet score, ejection fraction, body mass index, and number of coronary artery grafts., Interventions: None, observational., Measurements and Main Results: Urinary NGAL, a novel, highly sensitive biomarker for renal injury, was measured before and immediately after surgery and then 3, 18, and 24 hours later. There were no differences in urinary NGAL at any time point between patients subjected to off-pump or on-pump CABG surgery; the peak urinary NGAL in patients who underwent off-pump CABG surgery was 94.7 +/- 30.9 ng/mL compared with 122.7 +/- 57.0 ng/mL in patients with on-pump CABG surgery (p = 0.6). Peak serum creatinine and the incidence of acute kidney injury also were not different between the groups., Conclusions: Urinary NGAL was not different in patients undergoing off-pump and on-pump CABG surgery despite a very good match between the groups with respect to pre- and intraoperative risk factors.

Vasodilation due to impaired vascular tone is common in liver failure. Vasoconstrictor drugs are almost always required during the anhepatic phase of a liver transplant to maintain blood pressure unless venovenous bypass is employed. Arginine-vasopressin can be used as a vasoconstrictor instead of or in addition to norepinephrine for this purpose, but the effect of vasopressin on the portal vein pressure and flow in this setting is unknown. Portal vein pressure, portal vein blood flow, hemodynamic variables, and plasma vasopressin levels were measured in 16 patients during liver transplantation after ligation of the hepatic artery before and after a vasopressin infusion of 3.8 +/- 1.1 units/hour. Measurements were performed on the native liver prior to caval clamping. After vasopressin infusion, the portal vein pressure decreased significantly from 24.0 +/- 6.5 to 21.5 +/- 7.4 mm Hg [mean +/- standard deviation (SD), P = 0.006]. The portal vein blood flow also decreased (from 1.01 +/- 0.53 to 0.76 +/- 0.53 L/minute, mean +/- SD, P < 0.0001), as did the portal vein blood flow to cardiac output ratio (from 0.14 +/- 0.06 to 0.10 +/- 0.07, mean +/- SD, P < 0.0001). In conclusion, vasopressin significantly decreased portal vein pressure and flow of the native liver without decreasing cardiac output or intestinal perfusion in patients undergoing liver transplantations.

Several volatile anesthetics, including sevoflurane, protect against renal ischemia-reperfusion injury in vivo by reducing necrosis and inflammation. Furthermore, in cultured renal tubule cells, sevoflurane directly induced the phosphorylation of the cytoprotective kinases (ERK and Akt), upregulated 70-kDa heat shock protein (HSP70), and attenuated nuclear translocation of the proinflammatory transcription factor NF-kappaB. It has been shown that sevoflurane increases the release of transforming growth factor-beta1 (TGF-beta1) in human proximal tubule (HK-2) cells via externalization of plasma membrane phosphatidylserine (PS), and this increase in TGF-beta1 protected HK-2 cells against hydrogen peroxide-mediated necrosis. In this study, we aimed to determine whether the sevoflurane-mediated phosphorylation of ERK and Akt, induction of HSP70, and reduction in NF-kappaB activation are due to TGF-beta1 receptor-mediated signaling after PS externalization in HK-2 cells. Exogenous TGF-beta1 and a liposome mixture containing PS mimicked sevoflurane-mediated ERK and Akt phosphorylation and HSP70 induction in HK-2 cells. Sevoflurane and TGF-beta1 caused the nuclear translocation of the SMAD3 transcription factor in HK-2 cells. Furthermore, a neutralizing TGF-beta1 antibody or exogenous annexin V to bind PS prevented sevoflurane-induced ERK and Akt phosphorylation and HSP70 induction in HK-2 cells. Finally, a TGF-beta1 antibody and annexin V attenuated the reduction in nuclear translocation of NF-kappaB by sevoflurane. Therefore, we demonstrate in this study that sevoflurane-mediated cytoprotective and anti-inflammatory effects in HK-2 cells are at least partially due to the externalization of PS and activation of TGF-beta1 signaling pathways.

Background: Use of aprotinin has been associated with acute kidney injury after cardiac surgery. Neutrophil gelatinase-associated lipocalin (NGAL) is a novel, very sensitive marker for renal injury. Urinary NGAL may be able to detect renal injury caused by aprotinin. This study determined if the use of aprotinin is associated with an increased incidence of acute kidney injury and increased levels of urinary NGAL., Methods: In this prospective, observational study 369 patients undergoing cardiac surgery were enrolled. 205 patients received aprotinin and 164 received epsilon amino-caproic acid intraoperatively. Urinary NGAL was measured before and immediately after cardiac surgery and 3, 18 and 24 h later. The association of aprotinin use with the incidence of acute kidney injury (increase of serum creatinine >0.5 mg/dl) and NGAL levels was determined using logistic and linear regression models., Results: 51 of 205 patients (25%) who received aprotinin developed acute kidney injury compared to 19 of 164 patients (12%) who received epsilon amino-caproic acid (p = 0.0013). Aprotinin use was associated with a two-fold higher risk of acute kidney injury when adjusted for potential confounders (age, Parsonnet score, preoperative serum creatinine, cardiopulmonary bypass and cross-clamp times; multiple logistic regression: OR = 2.164; CI (95%) = 1.102 to 4.249; p = 0.0249. Urinary NGAL was 19 times higher immediately after cardiopulmonary bypass and 18 times higher 3 h later in patients who had received aprotinin (postoperative: 19.23; CI (95%) = 12.60 to 29.33; p < 0.0001; 3 h post-cardiopulmonary bypass 18.67; CI (95%) = 11.45 to 30.43; p < 0.0001)., Conclusions: Postoperative urinary NGAL - a novel marker for renal injury - is increased in cardiac surgical patients receiving aprotinin compared to patients receiving epsilon amino-caproic acid. These results further support the hypothesis that aprotinin may cause renal injury. The substantial rise of urinary NGAL associated with aprotinin use may in part be due to aprotinin blocking the uptake of NGAL by megalin/gp330 receptors in the proximal tubules., (Copyright 2008 S. Karger AG, Basel)