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The seismic potential of faults depends on the local mineralogy and can change upon mineral reactions. We conducted friction experiments on serpentinite, carbonate and carbonated serpentinite fault gouges at temperatures from 400°C to 630°C, under 100 MPa effective normal stress and fluid saturated conditions. Pure serpentinite fault gouges exhibited unstable slip with significant strain‐hardening. Carbonate‐bearing serpentinite fault gouges showed stable sliding at temperatures <500°C, but displayed unstable stick‐slip behavior and strong strain weakening at temperatures ≥500°C. Microstructural analyses revealed localization and the formation of olivine and pyroxene from devolatilization reactions at temperatures ≥500°C. The degree of devolatilization increased near major slip planes and was enhanced by higher temperature and carbonate content, as shown by three‐dimensional micro‐computer tomography analyses. Nano‐scale transmission electron microscopy analyses revealed the absence of hydrous and carbonate phases along major slip planes. We attribute the strong weakening and unstable slip behavior in carbonated serpentinite fault gouges to the formation of nano‐sized anhydrous phases of olivine and pyroxene along the slip plane. Our results indicate that serpentinized fault zones may experience seismic event nucleation at temperatures approaching the thermodynamic stability limit of serpentine. This suggests that the absence of seismic events cannot exclusively be attributed to serpentinization. The formation of carbonates, through replacive and additive carbonation, can explain aseismic deformation in transform faults, but at elevated temperatures, devolatilization reactions in carbonated serpentinites cause strong localization and strain weakening, accompanied by laboratory seismicity. Carbonated serpentinite fault gouges are common along tectonic interfaces and significantly impact how these areas deform. These fault rocks contain a mix of water‐ and carbon dioxide‐bearing minerals and their frictional behavior varies based on their mineralogical composition. In our experiments, we studied pure serpentinite and carbonated serpentinite fault gouges. We found stick‐slip behavior in pure serpentinites, which means earthquakes can nucleate. Presence of carbonates can prevent the nucleation of earthquakes. At temperatures of 500°C or higher, olivine and pyroxene minerals form due to devolatilization reactions, causing the rocks to weaken and slip unstably. Serpentinite fault gouges deform by frictional sliding at temperatures close to their stability limitAseismic behavior of ultramafic fault zones may be due to carbonation rather than serpentinization aloneDevolatilization in carbonated serpentinite fault gouges causes localization and promotes strain weakening Serpentinite fault gouges deform by frictional sliding at temperatures close to their stability limit Aseismic behavior of ultramafic fault zones may be due to carbonation rather than serpentinization alone Devolatilization in carbonated serpentinite fault gouges causes localization and promotes strain weakening

OBJECTIVETo evaluate the incidence of surgical-site infections (SSIs) in a cohort of liver transplant recipients and to assess risk factors predisposing patients to these infections.DESIGNProspective observational cohort study.SETTINGSingle transplant center in Canada.PATIENTSPatients who underwent liver transplantation between February 2011 and August 2014.METHODSMultivariate logistic regression was used to identify independent risk factors for SSIs in liver transplant patients.RESULTSWe enrolled 250 liver transplant recipients. The recipients’ median age at the time of transplantation was 56 years (range, 19–70 years), and 166 patients (66.4%) were male. Moreover, 47 SSIs were documented in 43 patients (17.2%). Organ-space, superficial, and deep SSIs were noted in 29, 7, and 3 patients, respectively. In addition, 2 patients developed superficial and organ-space SSIs, and another 2 patients were found to have deep as well as organ-space infections. In total, we identified 33 organ-space SSIs (70.2%), 9 superficial SSIs (19.1%), and 5 deep SSIs (10.6%). Factors predictive of SSIs by multivariate analysis were duct-to-duct anastomosis (odds ratio [OR], 3.88; 95% CI, 1.85–8.13; P<.001) and dialysis (OR, 3.57; 95% CI, 1.02–12.50; P=.046). Of the 66 organisms isolated in both deep and organ-space SSIs, 55 (83%) were resistant to cefazolin.CONCLUSIONSOrgan-space SSIs are a common complication after liver transplantation. Duct-to-duct anastomosis and dialysis were independent risk factors associated with SSIs. Appropriate perioperative prophylaxis targeting patients with duct-to-duct anastomosis and dialysis while simultaneously providing optimum coverage for the potential pathogens causing SSIs is warranted.Infect Control Hosp Epidemiol2017;38:1084–1090

New HCV therapies result in sustained viral eradication (SVR) in most immune-competent and immune-compromised patients. In liver transplant recipients (LTR), data mainly come from clinical trials. This real-life Canadian multicenter study (n=120) confirms the excellent results (SVR 85%) in LTR started on sofosbuvir-based regimens.

Type 2 hepatorenal syndrome (HRS2) is a functional renal impairment complicating end-stage liver disease. Although it is reversible after liver transplantation, long-term posttransplant outcomes in HRS2 patients remain ill-defined.

Pandemic H1N1 influenza has been associated with a worldwide outbreak of febrile respiratory illness. Although impaired cell mediated immunity, such as that caused by transplant immunosuppression, has been identified as a risk factor for severe infection with this virus, the course of this infection has not been adequately characterized in solid organ transplant (SOT) recipients in comparison with nontransplanted controls. We report our experience with severe pH1N1 infection in transplant recipients and compare this group with nonimmunosuppressed patients.

Little is known about donors' perception and psychologic impact of the physical changes that occur after (open) living donor hepatectomy. The aim of this study was to examine the body image and scar satisfaction after donor hepatectomy and to measure the relationship to postdonation quality of life.

Efficacy and long-term outcome of antiviral therapy for recurrent hepatitis C after liver transplantation is poorly defined.

Donor-specific immune tolerance has been reported in isolated cases of kidney transplantation associated with bone marrow transplantation. The following is a description of a living donor liver transplantation for a hilar cholangiocarcinoma in a previous recipient of an allogeneic bone marrow transplant.

Patients with end-stage renal disease are at high risk for hepatitis B (HBV) or hepatitis C virus (HCV) infection. Because therapy indication for viral hepatitis depends on virologic, biochemical, and histologic criteria, liver biopsy usually is necessary. Recently, a panel of serum fibrosis markers has been postulated to allow quantification of liver fibrosis by noninvasive means.

Unlike cadaveric liver transplantation, current attitudes in living donor liver transplantation (LDLT) quote increased risk factors in the potential recipient such as retransplantation, multiple previous surgeries, or preexisting recipient portal vein thrombosis (PVT) as absolute or relative contraindications to this procedure.

Cadaveric liver transplantation (5-year survival >80) represents the standard of care for end-stage liver disease (ESLD). Because the demand for cadaveric organs exceeds their availability, living-donor liver transplantation has gained increasing acceptance. Our aim was to assess the marginal cost-effectiveness of cadaveric and living-donor orthotopic liver transplantation (OLT) in adults with ESLD.

Abstract: Background: Graft rejection and infection remain major problems following liver transplantation; both are heavily influenced by the immunosuppressive regimen. Despite the disparity in the primary disease leading to transplantation, all patients receive the same post-transplant immunosuppressive treatment in a given center. The aim of this study is to detect a possible effect of the underlying disease on the incidence of early acute rejection episodes after orthotopic liver transplantation (OLT). Patients and Methods: Retrospective analysis on all 101 consecutive liver transplants performed in 95 patients between 1983 and March 1998; five of these patients, surviving less than 30 days, were not included. The immunosuppressive regimen was based on conventional triple therapy during the whole study period. The diagnosis and treatment of acute rejection within the first 30 days post-OLT was uniform throughout the whole study period. Results: Though there were no differences with respect to patients' characteristics [age, child classification, number of HLA-mismatches or cytomegalovirus (CMV)-serocompatibility], patients with primary biliary cirrhosis (PBC) showed a significant increase of acute rejection after OLT compared with the other patients transplanted for other liver diseases (P = 0.024). The incidence of infection was not elevated in patients transplanted for PBC when compared with other diagnoses. Conclusion: Our results indicate that primary liver disease may be a determinant for acute graft rejection in PBC. Furthermore, these results suggest that immunosuppressive regimens based on the underlying disease should be considered.

Background:A step decrease in positive end‐expiratory airway pressure (PEEP) is not followed by an instantaneous loss of the PEEP‐induced increase in end‐expiratory lung volume (EELV). Rather, the reduction of EELV is delayed, while adverse PEEP effects on hemodynamics are immediately attenuated upon the drop in airway pressure. Step PEEP increments were applied to the lungs of patients with acute lung injury. It was investigated retrospectively whether enlargement of end‐expiratory lung volume and changes in lung mechanics persist 45 min after removal of the PEEP increment. Methods:In 14 patients with acute lung injury (LIS score 2.7) EELV and volume‐dependent dynamic compliance of the respiratory system (Cdyn,rs) were determined 45 min after removal of an additional PEEP increment (0.64 kPa added to baseline PEEP of 1.0 kPa). Results:Nine patients kept an EELV gain of 13% (SD 7) and showed improved Cdyn,rs. In 5 patients, EELV was reduced (by 9% (SD 6)) and Cdyn,rsunchanged after removal of the PEEP increment compared to baseline. Conclusion:A subgroup of patients with acute lung injury, the characteristics of which remain to be defined, benefit from prolonged recruitment effects up to 45 min after removal of a PEEP increment, while sequelae of continuously increased airway pressures are minimised.

Background/Aims:Rat hepatocyte Na+/H+exchange is activated in vitro by growth factors and in vivo following partial hepatectomy. This study explored by which mechanism(s) it is activated in a cirrhosis model characterized by chronic stimulation of hepatocyte proliferation. Methods:Rat hepatocytes were isolated 4 weeks after bile duct ligation or sham operation. Intracellular pH (pHi) was fluorimetrically determined, and plasma membranes and messenger RNA (mRNA) were prepared from isolated hepatocytes by standard methods. Results:Resting pHi was higher in bile duct-ligated than in control rats (7.42 ± 0.03 vs. 7.06 ± 0.04; P< 0.001). Although plasma membrane lipid composition and intracellular buffering capacity were similar, initial Na+/H+exchange-mediated rates of pHi recovery following acid loading were higher in bile duct-ligated than in control rats (0.098 ± 0.011 vs. 0.055 ± 0.005 pH units/min; P< 0.05). The antiporter's set point was shifted ∼0.3 pH units towards more alkaline values and its steady-state mRNA levels were doubled after bile duct ligation. Conclusions:Hepatocellular Na+/H+exchange is transcriptionally and posttranscriptionally activated in rat biliary cirrhosis further supporting a relationship between hepatocyte proliferation and Na+/H+exchange activation.

Based on studies in the pig, secretin choleresis has been proposed to be initiated by colchicine-inhibitable, exocytic insertion into the basolateral cholangiocyte membrane of intracytoplasmatic vesicles containing a H+ATPase. Formal prof of this hypothesis in the intact liver of other species, however, is lacking. The effect of the microtubule inhibitor colchicine on the ductular bile formation and HCO−3secretion induced by secretin was, therefore, explored in a secretin-responsive rat model characterized by marked hyperplasia of bile ductules.

In the perfused rat liver, ursodeoxycholate in high dose produces an HCO3−-rich hypercholeresis which we have shown previously to be inhibited by replacement of perfusate Na+with Li+or by addition of amiloride (or amiloride analogues). In the present studies, we have determined whether such inhibition is associated with altered ursodeoxycholate biotransformation. Under control conditions, ursodeoxycholate infusion produced a 3.7-fold increase in bile flow and a 9.2-fold increase in biliary HCO3−output. By thin-layer chromatography, ursodeoxycholate radioactivity in bile was present in unconjugated form (15%) or as glycine or taurine amidates. Glucuronide conjugates of ursodeoxycholate accounted for <1% of biliary bile acids. Li+/Na+substitution decreased ursodeoxycholate-stimulated bile flow and HCO3−secretion by >90%, but decreased recovery of ursodeoxycholate and metabolites by only 25%. Amiloride or amiloride analogues decreased ursodeoxycholate-stimulated choleresis and HCO3−output by 38%–76%, yet did not cause decreased recovery of ursodeoxycholate and metabolites. Inhibition of the hypercholeresis was associated with a decrease in unconjugated ursodeoxycholate to <2% of total biliary bile acids, a striking increase in ursodeoxycholate glucuronides, and a reciprocal decrease in glycine and taurine amidates. With Li+/Na+substitution, the predominant metabolites were a mixture of the 24-ester and the 3-aketal (ethereal) glucuronide (29%), and amidation with glycine appeared to be selectively inhibited; with amiloride or its analogues, only the 3-ethereal glucuronide was formed (20%–60% of biliary bile acids), and both taurine and glycine amidation were inhibited. Thus, maneuvers that decrease Na+/H+exchange inhibit ursodeoxycholate hypercholeresis and cause replacement of unconjugated ursodeoxycholate in bile by its glucuronide. The secretion of unconjugated ursodeoxycholate, a lipophilic bile acid, appears to be necessary for hypercholeresis induced by high-dose ursodeoxycholate infusion.

For optimal timing of liver transplantation and for the evaluation of new pharmacotherapeutic options, objective modalities for estimating the liver's functional reserve and prognosis in an individual patient are highly desirable. In the past a number of tests and several scoring systems have been proposed and validated to varying degrees for this purpose. The issues still to be clarified include: (1) any observed prognostic value of individual quantitative function tests and of scoring systems must be validated in independent, large enough and well defined patient populations; (2) it must be prospectively defined which (serially performed) quantitative test(s) add(s) prognostic information for the individual patient to the survival estimates defined by the more universally available scores and in which disease state(s); and (3) existing scoring systems must be validated, or new ones developed, that allow follow-up data to be used in order to adapt the original prognosis estimate to the evolution of the disease, e.g. during therapy.

Objective: Acute obstruction of endotracheal tubes (ETT) increases airway pressure, decreases tidal volume, increases the risk of dynamic hyperinflation by prolonging the duration of passive expiration, and prevents reliable calculation of tracheal pressure. We propose a computer-assisted method for detecting ETT obstruction during controlled mechanical ventilation. The method only requires measurement of the expiratory flow. Design: Computer simulation; prospective study in two cases; retrospective study in one case and in seven patients with the adult respiratory distress syndrome (ARDS). Setting: Laboratory of the Section of Experimental Anaesthesiology (University of Freiburg); surgical adult intensive care units in a university hospital (University of Basel) and in a university affiliated hospital (Zentralklinikum Augsburg). Patients: 3 patients with partial ETT or bronchial obstructions and 7 ARDS patients. Measurements and results: Expiratory flow was measured using a pneumotachograph and integrated to obtain expiratory volume. The time-constant of passive expiration (τE) as a function of expired volume [τE(VE) function] was calculated from the expiratory volume/flow curve. We investigated the τE(VE) function of data obtained from: (1) computer simulation of mechanically ventilated homogeneous and inhomogeneous lungs intubated with ETTs of different sizes; (2) one patient with an artificial ETT obstruction of 7.5 and 25 % of the cross-sectional area of the ETT (case 1); (3) one patient with ETT obstruction due to secretions (case 2); (4) one patient with acute bronchial constriction (case 3); (5) seven ARDS patients who showed an increase in airway resistance of more than 2 cm H2O · s/l. It was found that an ETT obstruction caused an increase in τEin early expiration (at high flow), whereas τEin late expiration was virtually unchanged. The reason for this is the flow dependency of the increase in ETT resistance produced by ETT obstruction. Unlike ETT obstruction, an increase in pure airway resistance produced an increase in τEthroughout expiration. Conclusions: An ETT obstruction can be reliably distinguished from an increase in pure airway resistance by a characteristic pattern change in the τE(VE) function, which can be detected easily even by an automated pattern recognition system.

Several letters to the editor are presented in response to the articles presented in the previous issue including "Warts and All," "East Pakistan: The Politics of Catastrophe" and an article related to the selection of Willy Brandt as the best German Chancellor for Russians.