Randomised clinical trial: alisporivir combined with peginterferon and ribavirin in treatment-naïve patients with chronic HCV genotype 1 infection (ESSENTIAL II).

BACKGROUND: Alisporivir (ALV) is an oral, host-targeting agent with pangenotypic anti-hepatitis C virus (HCV) activity and a high barrier to resistance. AIM: To evaluate efficacy and safety of ALV plus peginterferon-α2a and ribavirin (PR) in treatment-naïve patients with chronic HCV genotype 1 infection. METHODS: Double-blind, randomised, placebo-controlled, Phase 3 study evaluating ALV 600 mg once daily [response-guided therapy (RGT) for 24 or 48 weeks or 48 weeks fixed duration] or ALV 400 mg twice daily RGT with PR, compared to PR alone. Following a Food and Drug Administration partial clinical hold, ALV/placebo was discontinued and patients completed treatment with PR only. At that time, 87% of patients had received ≥12 weeks and 20% had received ≥24 weeks of ALV/PR triple therapy. RESULTS: A total of 1081 patients were randomised (12% cirrhosis, 55% CT/TT IL28B). Addition of ALV to PR improved virological response in a dose-dependent fashion. Overall, sustained virological response (SVR12; primary endpoint) was 69% in all ALV groups vs. 53% in PR control. Highest SVR12 (90%) was achieved in patients treated with ALV 400 mg twice daily and PR for >24 weeks. Seven cases of pancreatitis were reported, with similar frequency between ALV/PR and PR control groups (0.6% vs. 0.8% respectively). Adverse events seen more frequently with ALV/PR than with PR alone were anaemia, thrombocytopenia, hyperbilirubinaemia and hypertension. CONCLUSIONS: Alisporivir, especially the 400 mg twice daily regimen, increased efficacy of PR therapy in treatment-naïve patients with HCV genotype 1 infection. The mechanism of action and pangenotypic activity suggest that alisporivir could be useful in interferon-free combination regimens.

Alisporivir with peginterferon/ribavirin in patients with chronic hepatitis C genotype 1 infection who failed to respond to or relapsed after prior interferon-based therapy: FUNDAMENTAL, a Phase II trial.

Alisporivir (ALV) is an oral, investigational host-targeting agent, with pangenotypic activity against hepatitis C virus (HCV). This randomized, double-blind, placebo-controlled, Phase II study explored the efficacy and safety of ALV with peginterferon-α2a/ribavirin (PR) in patients with chronic HCV genotype 1 infection in whom prior PR had failed (43% relapsers, 34% null responders and 23% partial responders). Four-hundred-and-fifty-nine patients were randomized (1:1:1:1) to ALV 600 mg once daily (QD), ALV 800 mg QD, ALV 400 twice daily (BID) or placebo plus PR for 48 weeks. When the global ALV trial programme was put on clinical hold, all patients in this study had received ≥31 weeks of randomized treatment; patients completed 48 weeks on PR alone. All ALV groups demonstrated superior rates of complete early virologic response (cEVR; primary endpoint) vs PR alone (P ≤ 0.0131), with highest cEVR rate seen with ALV 400 mg BID (74% vs 36% with PR alone; P < 0.0001). Respective SVR12 rates (key secondary endpoint) were 65% vs 26% in prior relapsers, 63% vs 5% in partial responders and 68% vs 3% in null responders. In patients who received >40 weeks of randomized treatment, the SVR12 rate was 89% for ALV 400 mg BID vs 30% for PR alone (P = 0.0053). Rates of viral breakthrough and relapse were lowest with ALV 400 mg BID. One case of pancreatitis (fully recovered) occurred with ALV/PR. Common AEs were headache, fatigue, anaemia, neutropenia and nausea. Hypertension was infrequent, but more common with ALV. ALV merits further investigation in interferon-free regimens in combination with direct-acting antiviral agents.

Long-term clearance of hepatitis C virus following interferon α-2b or peginterferon α-2b, alone or in combination with ribavirin.

Sustained virologic response (SVR) is the standard measure for evaluating response to therapy in patients with chronic hepatitis C (CHC). The aim of this study was to prospectively assess the durability of SVR in the pivotal studies of peginterferon (PEG-IFN) α-2b or IFN α-2b. We conducted two phase 3b long-term follow-up studies of patients previously treated for CHC in eight prospective randomized studies of IFN α-2b and/or PEG-IFN α-2b. Patients who achieved SVR [undetectable hepatitis C virus (HCV) RNA 24 weeks after completion of treatment] were eligible for inclusion in these follow-up studies. In total, 636 patients with SVR following treatment with IFN α-2b and 366 with SVR following treatment with PEG-IFN α-2b were enrolled. Definite relapse (quantifiable serum HCV RNA with no subsequent undetectable HCV RNA) was reported in six patients treated with IFN α-2b and three patients treated with PEG-IFN α-2b. Based on these relapses, the point estimate for the likelihood of maintaining response after 5 years was 99.2% [95% confidence interval (CI), 98.1-99.7%] for IFN α-2b and 99.4% (95% CI, 97.7-99.9%) for PEG-IFN α-2b. Successful treatment of hepatitis C with PEG-IFN α-2b or IFN α-2b leads to clinical cure of hepatitis C in the vast majority of cases.

Adherence to assigned dosing regimen and sustained virological response among chronic hepatitis C genotype 1 patients treated with boceprevir plus peginterferon alfa-2b/ribavirin.

BACKGROUND: Adherence to therapeutic regimens affects the efficacy of peginterferon alfa (P) and ribavirin (R) therapy in patients with chronic hepatitis C virus genotype 1. AIM: To determine if medication adherence impacts efficacy [sustained virological response (SVR)] with triple therapy that includes boceprevir (BOC) plus P/R. METHODS: Adherence was determined in two Phase 3 clinical studies with BOC: SPRINT-2 (previously untreated patients) and RESPOND-2 (patients who failed previous therapy with P/R). Adherence to the assigned duration of the dosing regimen and adherence to the three times a day (t.d.s.) dosing interval of 7-9 h for BOC were assessed by the recording of data from patients' dosing diaries and by the amount of study drug dispensed and returned. RESULTS: Most patients (63-71%) adhered to ≥80% of their assigned treatment duration and achieved SVR rates of 86-90%. In contrast, patients who adhered to <80% of their assigned treatment duration achieved SVR rates of 8-32% (P < 0.0001), particularly low in patients who failed previous therapy (SVR = 8-15%). Different rates of adherence (<60% to >80%) to the t.d.s. dosing interval (7-9 h) with BOC did not influence the SVR rates (SVR = 60-83%) with the exception of patients who failed previous treatment and adhered to <60% of the t.d.s. dosing interval with BOC (SVR = 48-50%; P = 0.005). CONCLUSIONS: The achievement of an SVR is more dependent on adherence to the assigned duration of treatment than adherence to the t.d.s. dosing interval with boceprevir. Adherence to >60% of t.d.s. dosing with boceprevir is important in patients who failed previous therapy.

Association of a polymorphism in the indoleamine- 2,3-dioxygenase gene and interferon-α-induced depression in patients with chronic hepatitis C.

Interferon (IFN)-α treatment for infectious diseases and cancer is associated with significant depressive symptoms that can limit therapeutic efficacy. Multiple mechanisms have been implicated in IFN-α-induced depression including immune, neuroendocrine and neurotransmitter pathways. To further explore mechanisms of IFN-α-induced depression and establish associated genetic risk factors, single nucleotide polymorphisms in genes encoding proteins previously implicated in IFN-α-induced depression were explored in two self-reported ethnic groups, Caucasians (n=800) and African Americans (n=232), participating in a clinical trial on the impact of three pegylated IFN-α treatment regimens on sustained viral response in patients with chronic hepatitis C. Before treatment, all subjects were free of psychotropic medications and had a score ≤20 on the Center for Epidemiologic Studies Depression Scale (CES-D), which was used to assess depressive symptom severity throughout the study. In Caucasians, a polymorphism (rs9657182) in the promoter region of the gene encoding indoleamine-2,3-dioxygenase (IDO1) was found to be associated with moderate or severe IFN-α-induced depressive symptoms (CES-D>20) at 12 weeks of IFN-α treatment (P=0.0012, P<0.05 corrected). Similar results were obtained for treatment weeks 24, 36 and 48. In subjects homozygous for the risk allele (CC, n=150), the odds ratio for developing moderate or severe depressive symptoms at treatment week 12 was 2.91 (confidence interval: 1.48-5.73) compared with TT homozygotes (n=270). rs9657182 did not predict depression in African Americans, who exhibited a markedly lower frequency of the risk allele at this locus. The findings in Caucasians further support the notion that IDO has an important role in cytokine-induced behavioral changes.

Use of calcium-channel blockers in pediatric renal transplant recipients.

Hypertension (HTN) is a significant problem in pediatric renal transplant (TP) recipients, predisposing the individuals to the development of cardiovascular disease and graft dysfunction. Calcium channel blockers (CCB) are considered excellent agents to treat post-TP HTN. We compared the efficacy and adverse effects of the two most commonly prescribed CCBs in our pediatric renal TP population: nifedipine (Procardia, or P) and amlodipine (Norvasc, or N). All patients (n = 24) had been started on a CCB for systolic (SBP) and/or diastolic BP (DBP) > 95%. There were no other changes in adjunctive antihypertensive medications or doses during the cross-over period. Post-TP, pretreatment (pretx) SBP was 137.6 +/- 10.9 mmHg. The post-treatment SBP were (in mmHg): 128.5 +/- 11.9 (all patients, n = 24) (p = 0.009 vs. pretx); 126.4 +/- 10.0 (P alone, n = 15) (p = 0.007 vs. pretx); 132.8 +/- 14.4 (P + other antihypertensive(s), n = 9) (p = 0.331, NS vs. pretx). The post-TP, pretreatment DBP was 88.2 +/- 11.1 mmHg. The post-treatment DBP were (in mmHg): 78.5 +/- 6.9 (all patients, n = 24) (p = 0.03 vs. pretx); 77.2 +/- 7.4 (P alone, n = 15) (p = 0.008 vs. pretx); 80.7 +/- 6.1 (P + other antihypertensive(s), n = 9) (p = 0.063, NS vs. pretx). P and N were equally effective in reducing SBP (p = 0.843, NS) and DBP (p = 0.612, NS). Cyclosporin A (CyA) dose (p = 0.81) and trough levels (p = 0.19) were similar in P- and N-treated patients. Calculated GFR was virtually identical in P- and N-treated patients (p = 0.89). Patients (or parents of) reported a higher incidence of various side-effects while receiving P, including headache, flushing, dizziness and leg cramps. Furthermore, 22/24 (91.7%) reported some degree of gingival hyperplasia during treatment with P, and all these patients reported a stabilization or reduction of hypertrophy after the switch from P to N. We conclude that CCBs (N) are efficacious drugs for the purpose of BP control and renal protection in pediatric renal TP recipients.

Haemophilus aphrophilus osteomyelitis after dental prophylaxis. A case report.

A 36-year-old patient who was otherwise healthy had acute osteomyelitis of the humeral shaft develop after routine prophylactic dental cleaning and ultrasonic scaling. Haemophilus aphrophilus grew on cultures of material obtained during biopsy of the humerus, and pathologic examination confirmed the diagnosis of acute osteomyelitis. Haemophilus aphrophilus, a fastidious gram negative bacillus, is part of the normal oral flora and is a rare pathogen. Osteomyelitis caused by Haemophilus aphrophilus has not been reported to occur after routine dental prophylaxis. The patient was treated successfully with surgical debridement and appropriate antibiotics.

Hemopexin decreases spontaneous chemiluminescence of cold preserved liver after reperfusion.

Hemopexin is a plasma protein with exceptionally high affinity for heme. During liver transplantation heme is released via lysis of transfused blood. This heme may catalyze peroxidative reactions that contribute to "reperfusion" injury of the organ. Using a rat liver model of cold storage and reperfusion we tested the potential anti-oxidant effects of hemopexin. After 3 h of cold storage rat liver was reperfused with warm oxygenated buffer. Spontaneous liver chemiluminescence, which is a parameter of oxyradical production, was measured during reperfusion and expressed as an index of free radical production (IFRP). Chemiluminescence reached a maximum within 5 min of reperfusion and decreased to baseline within 30 min. Addition of hemopexin to the perfusate (5 microM) significantly decreased the IFRP. By contrast, the control proteins albumin and gamma-globulin (10 microM) had a smaller non-significant effect. The data suggest that heme could be complexed by hemopexin during reperfusion, thus inhibiting heme mediated cellular injury.

Efficacy of interferon monotherapy in the treatment of relapsers and nonresponders with chronic hepatitis C infection.

Results of numerous studies have demonstrated similar efficacy profiles for the interferons (IFNs) currently approved for the treatment of chronic hepatitis C virus (HCV) infection. Although it has been suggested that some IFNs are more efficacious in certain patient populations, the current data support an equivalent efficacy and safety profile for these agents. Among patients requiring retreatment, no single study has made a direct comparison of IFN alfa-2b (IFN-alpha 2b) and consensus IFN (CIFN) in patients who have relapsed or have not responded to previous IFN therapy. However, at least 11 studies using IFN-alpha 2b and 1 using CIFN have demonstrated efficacy in the relapsing and nonresponding patient populations. A review of these studies suggests that overall efficacy and tolerability are similar regardless of IFN-alpha subtype. Overall, up to 59% and 83% of relapsed patients retreated with IFN have shown sustained response rates, as measured by negative HCV RNA titer and normalization of alanine aminotransferase (ALT) levels, respectively. Up to 14% and 25% of patients who failed to respond to previous IFN therapy have shown sustained HCV RNA response and normalization of ALT, respectively, after retreatment.

Chemiluminescent measurement of increased free radical formation after ischemia/reperfusion. Mechanisms of free radical formation in the liver.

It has been proposed that xanthine oxidase-derived superoxide mediates reperfusion injury in the liver; however, there is a little direct evidence to support this hypothesis. In this paper we describe a model system to directly and noninvasively measure oxyradical formation and hepatic injury in isolated perfused rat liver. Using this sensitive chemiluminescent technique, we clearly demonstrate the theorized burst in oxygen radical production upon reperfusion of previously ischemic liver, without perturbing the system with chemical luminescence enhancers. This increase in chemiluminescence (CL) upon reperfusion was diminished by the free radical scavengers trolox and ascorbate, as well as N-2-mercaptoproprionyl-glycine (MPG), thereby confirming the oxyradical nature of this signal. Additionally, superoxide dismutase and the xanthine oxidase inhibitor allopurinol, but not catalase, attenuated the reperfusion effect, providing the most direct evidence so far that XOD derived superoxide anion is formed during liver reperfusion. Hepatic injury (AST release) did not appear to relate to increased CL, supporting the notion that the oxyradical flux may serve as a signal for other events leading to tissue injury. Further studies using this sensitive chemiluminescent technique should aid in delineating the detailed mechanism(s) of reperfusion injury.

Hepatic free radical production after cold storage: Kupffer cell-dependent and -independent mechanisms in rats.

BACKGROUND/AIMS: Free radicals are important mediators of reperfusion injury; however, the mechanism(s) of oxyradical production after liver reimplantation are not well understood. A model of cold storage and reperfusion using low-level chemiluminescence to directly measure oxyradical production during reperfusion was developed. METHODS: Rat livers were harvested and stored at 4 degrees C in University of Wisconsin cold-storage solution or Euro-Collins solution for 0-48 hours and then flushed and reperfused with warm oxygenated (37 degrees C) Krebs-Henseleit buffer. Liver chemiluminescence was measured using a sensitive photomultiplier tube, and hepatocellular injury was assessed by measuring aspartate aminotransferase release into the perfusate. RESULTS: Chemiluminescence reached a maximum within 5 minutes of reperfusion and then decreased to a baseline within 30 minutes. There was a marked increase in chemiluminescence after only a short period of storage in University of Wisconsin cold-storage solution. Chemiluminescence decreased with longer periods of storage but steadily increased again after 16 hours of storage. Chemiluminescence after 22 hours of storage, but not after 3 hours of storage, was decreased by pretreatment with the Kupffer cell inactivator gadolinium chloride. CONCLUSIONS: The data suggest two mechanisms of oxyradical production during cold storage and reperfusion of the rat liver. The later phase seems to be Kupffer cell dependent.

Transjugular intrahepatic portosystemic shunting: decreased survival for patients with high APACHE II scores.

OBJECTIVES: To determine which clinical characteristics are associated with decreased survival after transjugular intrahepatic portosystemic shunting (TIPS). METHODS: Forty-nine consecutive patients were treated with TIPS; 46 of them had refractory variceal bleeding. Univariate statistics and logistic regression analyses were used to determine the relationship between clinical, biochemical, and hemodynamic variables and 30-day) survival. RESULTS: Shunt insertion was successful in 48 (98.0%) of 49 cases. Median portal-systemic gradient was reduced from 22.5 (range 9-36) [median (5th-95th percentile)] to 12 (range 4-20) mm Hg. Thirty (61.2%) of 49 patients survived more than 30 days; four patients died more than 30 days after TIPS in mean follow-up of 8.4 months. Significant differences (p < 0.05) were found between those who survived more than 30 days and those who did not, with respect to preprocedural prothrombin time, bilirubin, albumin, alanine aminotransferase, and treatment with vasopressin and nitrates, balloon tamponade, or mechanical ventilation. Whereas there were no significant differences between the pre- and post-TIPS portal vein pressures and portal-systemic gradients in survivors and non-survivors, the pre- and post-TIPS hepatic vein pressures were significantly lower in survivors. Survival was inversely proportional to Child-Pugh class (p < 0.01) and to APACHE II score (p < 0.01). The single determinant most closely associated with decreased survival in the month after TIPS was the APACHE II score, a score of 18 stratifying patients into those at low and high risk of mortality [odds ratio 21.7 (CI 3.6-131.7)]. Only 1 (7.7%) of 13 patients with Child-Pugh C cirrhosis and an APACHE II score exceeding 18 survived more than 30 days. CONCLUSIONS: Patients with advanced cirrhosis, especially those with high pre-TIPS APACHE II scores, are at high risk for reduced survival after TIPS, despite adequate portal decompression.

Endotoxin-stimulated nitric oxide production increases injury and reduces rat liver chemiluminescence during reperfusion.

BACKGROUND/AIMS: Nitric oxide has many physiological functions and may play an important role in modulating tissue injury. However, the mechanism of NO action in ischemia/reperfusion injury is completely unknown. This report investigates the role of NO in hepatic reperfusion injury. METHODS: Rat liver was oxygenated for 30 minutes, followed by 30 minutes of ischemia, and then reperfused for 30 minutes. Perfusate was sampled for aspartate aminotransferase content, as an indication of hepatic injury, and for nitrite, an index of NO production. Spontaneous organ chemiluminescence was continuously monitored as a measure of oxyradical production. RESULTS: NO production by the perfused rat liver was induced in vivo by pretreatment with Escherichia coli lipopolysaccharide. This induction led to an increase in hepatic injury during reperfusion that was partially ameliorated by the NO synthase inhibitor NG-monomethyl-L-arginine. Chemiluminescence during reperfusion, a measure of superoxide production in this system, was also decreased in the lipopolysaccharide-treated animals, and this effect was blunted by NG-monomethyl-L-arginine. CONCLUSIONS: These data suggest that NO may combine with superoxide formed during reperfusion to directly cause hepatocellular injury. In vitro work shows that this chemical product is the highly toxic species peroxynitrite.

Evaluation of purine nucleoside phosphorylase release as a measure of hepatic endothelial cell injury.

With emerging data that endothelial cell (EC) injury is the limiting factor in liver preservation and hepatic function, a simple and reliable biochemical technique for monitoring EC injury is needed. Measurement of purine nucleoside phosphorylase (PNP) release into the circulation from perfused liver has been proposed as such a method. However, our experiments with perfused rat liver did not display a clear or direct relationship between PNP release and endothelial cell injury. Therefore, we re-examined the suitability of using PNP as a measure of nonparenchymal injury by measuring its distribution in purified populations of hepatocytes, ECs, and Kupffer cells (KCs) and correlating cell injury and enzyme release in short-term cultures at 37 degrees C of each cell type. Purified cells were incubated (4 x 10(6) cells/mL) in oxygen or nitrogen saturated. Wisconsin solution or Krebs buffer for 6 hours, with cell viability and PNP release assayed every 2 hours. ECs had the lowest specific activity (27 +/- 9 U/mg protein; mean +/- standard error of the mean [SEM]) compared with both hepatocytes (115 +/- 15) and KCs (66 +/- 18). Despite a decrement in EC and KC viability over time in each incubation solution, there was poor correlation between time of incubation and PNP release (r = .01 to .22), and between cell viability and PNP release (r = .01 to .16). In contrast, PNP release from incubated hepatocytes correlated with the length of incubation (r = .57 to .78) as well as cell injury (r = .63 to .77) in all four test solutions.(ABSTRACT TRUNCATED AT 250 WORDS)

Increased oxyradical production during reoxygenation of perfused rat liver. Signal versus injury.

Despite general agreement on the importance of oxyradicals in mediating "reperfusion" injury, the precise event(s) mediated by increased free radical production remain unclear. In this study we describe for the first time a model of unenhanced chemiluminescence of isolated perfused rat liver demonstrating a marked increase in oxyradical production after reoxygenation. Using aspartate aminotransferase and purine nucleoside phosphorylase release as measures of liver injury, there was no direct link between oxyradical production and hepatic injury. However, there was an abrupt increase in neutrophil chemotaxis activity in the perfusate at the time of reoxygenation with a subsequent decrement, following the pattern of oxyradical production. These data suggest that free radical formation during hepatic reperfusion may mediate signal transduction, as opposed to direct cell injury, as a primary mechanism of action.

Rapid conversion to high xanthine oxidase activity in viable Kupffer cells during hypoxia.

It has been widely postulated that the central mechanism of hepatic reperfusion injury involves the conversion, during ischemia, of the enzyme xanthine dehydrogenase (XDH) to its free radical-producing form, xanthine oxidase (XOD). However, this theory has been questioned because (a) XDH to XOD conversion in whole liver occurs very slowly; (b) the cellular distribution of XDH/XOD is unclear; and (c) the direct demonstration of XDH to XOD conversion in viable cells is lacking. In this paper, we address all three issues by measuring XDH to XOD conversion and cell viability in purified populations of hepatic endothelial cells (EC), Kupffer cells (KC), and hepatocytes (HEP). Although XDH/XOD activity on a cellular basis was greater in hepatocytes (0.92 +/- 0.12 mU/10(6) cells) than ECs (0.03 +/- 0.01) or KCs (0.12 +/- 0.04), XDH + XOD specific activity was similar in all three cell types (HEP 1.85 +/- 0.10 U/g protein; EC 1.69 +/- 0.54; KC 2.30 +/- 0.22). Over 150 min of warm (37 degrees C) or 24 h of cold (4 degrees C) hypoxia, percent XOD activity increased slowly in ECs, from 21 +/- 2% (basal) to 39 +/- 3% (warm) and 49 +/- 5% (cold) and in HEPs (29 +/- 2% to 38 +/- 3% and 49 +/- 2%), but converted significantly faster in KCs (28 +/- 3% to 91 +/- 7% and 94 +/- 4%). The dramatic changes in Kupffer cell XOD during cold hypoxia occurred despite only minor changes in cell viability. When hypoxic KCs were reoxygenated after 16 h of cold hypoxia, there was a marked increase in cell death that was significantly blocked by allopurinol. These data suggest that significant conversion to the free radical-producing state occurs within viable KCs, and that Kupffer cell XOD may play an important role in mediating reperfusion injury in the liver.

Evaluation of University of Wisconsin cold-storage solution in warm hypoxic perfusion of rat liver: the addition of fructose reduces injury.

BACKGROUND: University of Wisconsin cold-storage solution (UW solution) has markedly improved organ preservation for liver transplantation. However, the efficacy of this solution in preserving hepatocyte viability during warm ischemia is undefined; hence, the effects of UW solution on warm hypoxic injury in the isolated perfused rat liver were examined. METHODS: Livers were perfused using a modified protocol that included a period of hypoxic perfusion with isosmotic Krebs' solution at the end of each experiment. Hepatic injury was evaluated by aspartate aminotransferase (AST) release into the perfusate and the trypan blue perfusion technique. RESULTS: Although UW solution appeared to decrease hepatic injury during hypoxic perfusion, as reflected by low AST release, perfusion with UW solution led to hepatocyte shrinkage and cessation of bile flow even under oxygenated conditions. UW solution did not protect against warm hypoxic injury, as assessed by AST release into the perfusate (182 +/- 15 U/mL, mean +/- SD) or trypan blue staining of the dead hepatocyte nuclei (56% +/- 5%). However, the addition of fructose to UW solution resulted in a significant decrease in AST release (66 +/- 15 U/mL) and parenchymal cell death (39% +/- 7%). CONCLUSIONS: These data suggest that the addition of fructose or other gluconeogenic substrates may complement the overall hepatoprotective effects of UW solution, particularly during periods of warm hypoxia.