Rearing mice at 22°C programs increased capacity to respond to chronic exposure to cold but not high fat diet.

OBJECTIVE: Rodent models raised at environmental temperatures of 21-22 °C are increasingly switched to thermoneutral housing conditions in adulthood to better capture human physiology. We quantified the developmental effects of rearing mice at an ambient temperature of 22 °C vs. 30 °C on metabolic responses to cold and high fat diet (HFD) in adulthood. METHODS: Mice were reared from birth to 8 weeks of age at 22 °C or 30 °C, when they were acclimated to single housing at the same temperature for 2-3 weeks in indirect calorimetry cages. Energy expenditure attributable to basal metabolic rate, physical activity, thermic effect of food, and adaptive cold- or diet-induced thermogenesis was calculated. Responses to cooling were evaluated by decreasing the ambient temperature from 22 °C to 14 °C, while responses to HFD feeding were assessed at 30 °C. Influences of rearing temperature on thermogenic responses that emerge over hours, days and weeks were assessed by maintaining mice in the indirect calorimetry cages throughout the study. RESULTS: At an ambient temperature of 22 °C, total energy expenditure (TEE) was 12-16% higher in mice reared at 22 °C as compared to 30 °C. Rearing temperature had no effect on responses in the first hours or week of the 14 °C challenge. Differences emerged in the third week, when TEE increased an additional 10% in mice reared at 22 °C, but mice reared at 30 °C could not sustain this level of cold-induced thermogenesis. Rearing temperature only affected responses to HFD during the first week, due to differences in the timing but not the strength of metabolic adaptations. CONCLUSION: Rearing at 22 °C does not have a lasting effect on metabolic adaptations to HFD at thermoneutrality, but it programs an enhanced capacity to respond to chronic cold challenges in adulthood. These findings highlight the need to consider rearing temperature when using mice to model cold-induced thermogenesis.

Videolaparoscopic microwave ablation in patients with HCC at a European high-volume center: Results of 815 procedures.

BACKGROUND: Videolaparoscopic (VL) microwave ablation (MWA) is not included in most of the international guidelines as a therapeutic option for hepatocellular carcinoma (HCC). Aim of this study was to assess the safety of VL MWA in patients with HCC for whom resection or percutaneous ablation is unsuitable. METHODS: A retrospective analysis was performed on a prospective database of patients with HCC treated with VL MWA at our institution from 2009 to 2016. Patient demographics, operational characteristics, and complications were recorded. Statistical analysis was performed to identify safety profile, overall survival and recurrence rate. RESULTS: A total of 815 VL MWA were performed in 674 patients with a mean age of 64 years. Patients had a mean Model for End-stage Liver Disease score of 10 (±3); 32.8% were Child B, 44.1% Barcelona Clinic Liver Cancer B-C. Perioperative mortality was 0.4%. Overall morbidity was 30.8%, with Dindo-Clavien complications ≥3 in 2%. The median length of stay was 2 days. In 43.1% VL MWA was the first-line therapy. Overall 1-, 3-, and 5-year survival rates were 81.9%, 54.9%, and 35.9%. CONCLUSIONS: The present is the largest series of VL ablation and the bigger number of patients with HCC treated with MW reported nowadays. It confirms the safety of a minimally invasive procedure for patients with HCC when resection or percutaneous ablation is not feasible.

Social environment modulates anxiogenic effects of caffeine in zebrafish.

Zebrafish has recently become a species of choice in a number of preclinical studies to examine whether and how psychoactive compounds modulate individual and social behaviors. Here, we sought to contribute an improved understanding of the effects of caffeine, a well-known anxiogenic compound, on the swimming activity and the collective response of zebrafish. To investigate how the social environment influences individual response to acute caffeine treatment, we measured the behavior of a caffeine-treated subject swimming in isolation or in the presence of a group of untreated conspecifics. The experimental paradigm used a recently developed automatic tracking system to extract individual trajectories of zebrafish and preserve their identities over time. Our results indicate that caffeine reduces the swimming activity of fish tested in isolation, and that this effect is mitigated by the presence of untreated conspecifics. The collective response is also influenced by caffeine exposure at low doses, whereby caffeine-treated subjects may act as group leaders by taking anticipatory turning manoeuvres that are followed by the rest of the group. While anxiogenic effects of caffeine could explain the reduction in the swimming activity, the observed variation in the collective response is likely related to the interplay between anxiogenic and psychostimulant properties of caffeine.

The Tagging Procedure of Visible Implant Elastomers Influences Zebrafish Individual and Social Behavior.

One commonly used method to preserve individual identity in the study of social behavior of zebrafish is through silicone-based visible implant elastomers (VIEs), which represent a safe and durable tagging procedure. While the effects of VIE tagging on welfare and general health have been addressed in detail, whether this procedure influences social behavior remains unclear. In this study, we compared individual and group behaviors exhibited by shoals composed of three individuals: two nontagged and one (focal subject) that was either nontagged (control condition) or sham-, purple-, blue-, or yellow tagged. Traditional behavioral parameters of activity, shoaling, and schooling (speed, polarization, and interindividual distances), along with an information-theoretic measure of social interaction (transfer entropy), were used to study the effect of tagging. Our findings indicate that tagging procedure per se significantly increased individual speed of the tagged subjects and of the group. The tagging procedure also altered the level of interaction between individuals, measured by transfer entropy. Conversely, tagging procedure did not influence shoaling and schooling tendencies. These findings suggest that VIE tagging may elicit some level of stress, which may affect some behavioral responses more than others. We recommend use of alternative methods such as multitracking systems when possible.

Information theory and robotics meet to study predator-prey interactions.

Transfer entropy holds promise to advance our understanding of animal behavior, by affording the identification of causal relationships that underlie animal interactions. A critical step toward the reliable implementation of this powerful information-theoretic concept entails the design of experiments in which causal relationships could be systematically controlled. Here, we put forward a robotics-based experimental approach to test the validity of transfer entropy in the study of predator-prey interactions. We investigate the behavioral response of zebrafish to a fear-evoking robotic stimulus, designed after the morpho-physiology of the red tiger oscar and actuated along preprogrammed trajectories. From the time series of the positions of the zebrafish and the robotic stimulus, we demonstrate that transfer entropy correctly identifies the influence of the stimulus on the focal subject. Building on this evidence, we apply transfer entropy to study the interactions between zebrafish and a live red tiger oscar. The analysis of transfer entropy reveals a change in the direction of the information flow, suggesting a mutual influence between the predator and the prey, where the predator adapts its strategy as a function of the movement of the prey, which, in turn, adjusts its escape as a function of the predator motion. Through the integration of information theory and robotics, this study posits a new approach to study predator-prey interactions in freshwater fish.

Three-dimensional scoring of zebrafish behavior unveils biological phenomena hidden by two-dimensional analyses.

The study of zebrafish behavior represents a cornerstone upon which basic researchers promise to advance knowledge in life sciences. Although zebrafish swim in a three-dimensional (3D) space, their behavior in the lab is almost exclusively scored in two dimensions, whereby zebrafish are recorded using a single camera providing 2D videos. Whether this dimensional reduction preserves the reliability of data has not been addressed. Here we show that, compared to a 3D observation, 2D data are flawed by over-reporting and under-reporting of locomotory differences. Specifically, we first reconstructed 3D trajectories through the integration of synchronous information derived from two cameras, and then compared them with the original 2D views in classical experimental paradigms assessing shoaling tendency, fear, anxiety, and general locomotion. Our results suggest that traditional behavioral scoring of individual zebrafish performed in 2D may undermine data integrity, thereby requiring a general reconsideration of scoring zebrafish behavior to incorporate a 3D approach. We then demonstrate that, compared to 2D, a 3D approach requires a reduced number of subjects to achieve the same degree of validity. We anticipate these findings to largely benefit animal welfare by reducing the number of experimental subjects, without affecting statistical power.

Zebrafish response to a robotic replica in three dimensions.

As zebrafish emerge as a species of choice for the investigation of biological processes, a number of experimental protocols are being developed to study their social behaviour. While live stimuli may elicit varying response in focal subjects owing to idiosyncrasies, tiredness and circadian rhythms, video stimuli suffer from the absence of physical input and rely only on two-dimensional projections. Robotics has been recently proposed as an alternative approach to generate physical, customizable, effective and consistent stimuli for behavioural phenotyping. Here, we contribute to this field of investigation through a novel four-degree-of-freedom robotics-based platform to manoeuvre a biologically inspired three-dimensionally printed replica. The platform enables three-dimensional motions as well as body oscillations to mimic zebrafish locomotion. In a series of experiments, we demonstrate the differential role of the visual stimuli associated with the biologically inspired replica and its three-dimensional motion. Three-dimensional tracking and information-theoretic tools are complemented to quantify the interaction between zebrafish and the robotic stimulus. Live subjects displayed a robust attraction towards the moving replica, and such attraction was lost when controlling for its visual appearance or motion. This effort is expected to aid zebrafish behavioural phenotyping, by offering a novel approach to generate physical stimuli moving in three dimensions.

The role of adipose stem cells in inflammatory bowel disease: From biology to novel therapeutic strategies.

Inflammatory bowel diseases are an increasing phenomenon in western countries and in growing populations. The physiopathology of these conditions is linked to intestinal stem cells homeostasis and regenerative potential in a chronic inflammatory microenvironment. Patients with IBD present an increased risk of developing colorectal cancer (CRC), or colitis associated cancer (CAC). Conventional treatment for IBD target the inflammatory process (and include anti-inflammatory and immunosuppressive drugs) with biological agents emerging as a therapeutic approach for non-responders to traditional therapy. Conventional treatment provides scarce results and present severe complications. The intestinal environment may host incoming stem cells, able to engraft in the epithelial damaged sites and differentiate. Therefore, stem cell therapies represent an emerging alternative in inflammatory bowel diseases, with current investigations on the use of haematopoietic and mesenchymal stem cells, in particular adipose stem cells, apparently fundamental as regenerators and as immune-modulators. Here, we discuss stem cells in intestinal homeostasis and as therapeutic agents for the treatment of inflammatory bowel diseases.

Laparoscopic microwave thermal ablation for late recurrence of local hepatocellular carcinoma after liver transplant: case report.

Liver transplant is the preferred treatment for hepatocellular carcinoma in patients with cirrhosis, as both neoplastic and cirrhotic liver tissue can be removed. Treatment of recurring neoplasms is a difficult issue, especially in long-term survivors of liver transplant. No consensus has been reached on the treatment of recurrent hepatocellular carcinoma. Although patients with extrahepatic metastases are generally not candidates for local therapy, successful multimodal salvage therapy including resection or ablation can be achieved in liver transplant recipients with local recurrence of hepatocellular carcinoma. Microwave ablation is safe and effective for treating unresectable hepatocellular carcinoma, achieving excellent results in local disease down-staging or as a "bridge" to liver transplant, with no significant differences in local recurrence and complications compared with the more commonly used radiofrequency ablation. A patient with local recurrence of hepatocellular carcinoma 36 months after liver transplant for multifocal hepatocellular carcinoma and cirrhosis due to hepatitis C was successfully treated with laparoscopic microwave ablation without any postoperative complications. The patient is disease free 24 months after microwave ablation.

Laparoscopic microwave ablation in patients with hepatocellular carcinoma: a prospective cohort study.

OBJECTIVES: There are no prospective studies of laparoscopic microwave (MW) ablation in patients with hepatocellular carcinoma (HCC). The aim of this study was to demonstrate the safety and efficacy of laparoscopic MW ablation. METHODS: A prospective study group of consecutive HCC patients considered ineligible for liver resection and/or percutaneous ablation was conducted from December 2009 to December 2010. Short-term (3-month) outcomes included a centralized revision of radiological response, mortality and morbidity. Mid-term (24-month) outcomes included time to recurrence in the study group compared with that in a cohort of consecutive patients treated with laparoscopic radiofrequency (RF) ablation using propensity score analysis. RESULTS: A total of 42 patients were enrolled. Their median age was 64 years; 67% were positive for hepatitis C virus; 33% were of Child-Pugh class B status; the median tumour diameter was 2.5 cm, and 48% of patients had multinodular HCC. In 47 of 50 (94%) nodules treated with MW ablation, a complete radiological response was observed at 3 months. There was no perioperative mortality. The overall morbidity rate was 24%. The 2-year survival rate was 79% and the 2-year recurrence rate was 55%. Using propensity score analysis (in 28 MW ablation patients and 28 RF ablation controls), 2-year recurrence rates were 55% in the MW ablation group and 77% in the control group (P = 0.03). CONCLUSIONS: Laparoscopic MW ablation is a safe and effective therapeutic option for selected HCC patients who are ineligible for liver resection and/or percutaneous ablation.

Laparoscopic ablation of hepatocellular carcinoma in cirrhotic patients unsuitable for liver resection or percutaneous treatment: a cohort study.

The aim of this study was to demonstrate the safety and efficacy of laparoscopic ablation for cirrhotic HCC patients. Between January 2004 and December 2009, laparoscopic ablation was applied prospectively in 169 consecutive HCC patients (median age 62 years, 43% hepatitis C positive) considered ineligible for liver resection and/or percutaneous ablation. There was clinically relevant portal hypertension in 72% of cases. A significant proportion of subjects (50%) had multinodular tumors or nodules larger than 25 mm. The main ablation techniques used were radiofrequency in 103 patients (61%), microwave ablation in 8 (5%), and ethanol injection in 58 (34%). The primary endpoint was 3-year survival. There was no perioperative mortality. The overall morbidity rate was 25%. The median postoperative hospital stay was 3 days (range 1-19 days). Patients survived a median 33 months with a 3-year survival rate of 47%. Cox's multivariate analysis identified patient age, presence of diabetes, albumin ≤37 g/l, and alpha-fetoprotein >400 µg/l as significant preoperative predictors of survival, while the chance to undergo liver transplantation and postoperative ascites were the only independent postoperative predictor of survival. Laparoscopic ablation is a safe and effective therapeutic option for selected HCC patients ineligible for liver resection and/or percutaneous ablation.

Gender differences in the quality of life of patients with liver cirrhosis related to hepatitis C after liver transplantation.

BACKGROUND: Hepatitis C virus (HCV) infection frequently leads to chronic liver disease, which adversely affects the quality of life (QoL) of the patient. The gender of the patient may be an important variable in the way severity of the disease is perceived. The aim of our study is to evaluate the effect of the gender variable on QoL in HCV-positive patients. METHODS: This study included a total of 52 patients (26 men and 26 women) who completed a 1-year follow-up after liver transplantation. QoL was assessed using the SF-36 questionnaire. RESULTS: Male subjects have significantly higher scores on physical role functioning, bodily pain and physical activity compared with females. Females have a better QoL compared to males with regard to the emotional state and mental health. CONCLUSIONS: These results show a significant effect of the gender variable on QoL in HCV patients.

Use of N-acetylcysteine during liver procurement: a prospective randomized controlled study.

Antioxidant agents have the potential to reduce ischemia/reperfusion damage to organs for liver transplantation (LT). In this prospective, randomized study, we tested the impact of an infusion of N-acetylcysteine (NAC) during liver procurement on post-LT outcomes. Between December 2006 and July 2009, 140 grafts were transplanted into adult candidates with chronic liver disease who were listed for first LT, and according to a sequential, closed-envelope, single-blinded procedure, these patients were randomly assigned in a 1/1 ratio to an NAC protocol (69 patients) or to the standard protocol without NAC [71 patients (the control group)]. The NAC protocol included a systemic NAC infusion (30 mg/kg) 1 hour before the beginning of liver procurement and a locoregional NAC infusion (300 mg through the portal vein) just before cross-clamping. The primary endpoint was graft survival. The graft survival rates at 3 and 12 months were 93% and 90%, respectively, in the NAC group and 82% and 70%, respectively, in the control group (P = 0.02). An adjusted Cox analysis showed a significant NAC effect on graft survival at both 3 months [hazard ratio = 1.65, 95% confidence interval (CI) = 1.01-2.93, P = 0.04] and 12 months (hazard ratio = 1.73, 95% CI = 1.14-2.76, P ≤ 0.01). The incidence of postoperative complications was lower in the NAC group (23%) versus the control group (51%, P < 0.01). In the subgroup of 61 patients (44%) receiving suboptimal grafts (donor risk index > 1.8), the incidence of primary dysfunction of the liver was lower (P = 0.09) for the NAC group (15%) versus the control group (32%). In conclusion, the NAC harvesting protocol significantly improves graft survival. The effect of NAC on early graft function and survival seems higher when suboptimal grafts are used.

Hepatitis C virus infection and health-related quality of life.

Hepatitis C virus (HCV) hepatitis and other diseases related to HCV, such as cryoglobulinemia, lymphoma and renal failure, impair health-related quality of life (HRQoL). In addition, HCV per se might directly influence HRQoL via colonization of microglia in the brain or, indirectly, via the effect of systemic inflammatory cytokines which, in turn, can trigger brain interleukin production. The treatment of HCV-related disorders with interferon (IFN) has an effect on HRQoL. Initially, IFN causes a transient deterioration of HRQoL, due to the induction of depression and other side effects of treatment. Subsequently, the subjects who obtain a sustained virologic response experience an improvement in HRQoL. Only rarely does interferon treatment causes permanent detrimental effects on HRQoL, due to residual psychiatric or neurologic side effects. Liver transplantation is the only treatment for end-stage HCV-related liver disease. HRQoL generally improves massively a few months after transplantation, except in the case of serious complications of the transplant procedure. Furthermore, high levels of anxiety and neuroticism pre-transplant are associated with lower HRQoL one year after transplant. Additionally, six months after transplant, patients with HCV who experience virologic recurrence show significantly greater depression, anxiety, phobic anxiety, and paranoid ideation than anti-HCV-negative patients. In conclusion, optimal care for the overall well-being of patients with HCV infection requires adequate knowledge of their neurological and psychological status.

Hepatitis C virus adversely affects quality of life.

BACKGROUND: Chronic liver disease secondary to hepatitis C virus (HCV) infection is a common clinical problem. HCV is likely to adversely affect the quality of life (QoL) of the patient. This effect is said to be disproportionate to the severity of the disease. The aim of our study was to evaluate QoL in HCV-positive patients focusing both on health status and subjective satisfaction. METHODS: Twenty-four patients with combined HCV and alcoholic liver disease (ETOH-HCV) were enrolled in the study. We adopted two generic tools: SF-36 (a health status questionnaire) and SAT-P (a satisfaction profile) for psychological assessment of the patients. SF-36 and SAT-P scores of ETOH-HCV patients were compared with scores of 23 patients with alcoholic liver disease (ETOH). The scores obtained from the study groups were also compared with the reference scores of the healthy Italian population. RESULTS: Both the groups were comparable with respect to age, histological and clinical severity of liver disease (as assessed by MELD and Child Pugh scores). Patients with ETOH-HCV scored less in the vitality and role emotional status domains of the SF-36 scores and the psychological function, social function and free time domains of the satisfaction profile. CONCLUSIONS: These results show a significant impact of HCV infection on health status and subjective satisfaction.

Machine perfusion at 20°C reduces preservation damage to livers from non-heart beating donors.

We previously reported that machine perfusion (MP) performed at 20°C enhanced the preservation of steatotic rat livers. Here, we tested whether rat livers retrieved 30 min after cardiac arrest (NHBDs) were better protected by MP at 20°C than with cold storage. We compared the recovery of livers from NHBDs with organs obtained from heart beating donors (HBDs) preserved by cold storage. MP technique: livers were perfused for 6h with UW-G modified at 20°C. Cold storage: livers were perfused in situ and preserved with UW solution at 4°C for 6h. Both MP and cold storage preserved livers were reperfused with Krebs-Heinselet buffer (2h at 37°C). AST and LDH release and mitochondrial glutamate dehydrogenase (GDH) levels were evaluated. Parameters assessed included: bile production and biliary enzymes; tissue ATP; reduced and oxidized glutathione (GSH/GSSG); protein-SH group concentration. Livers preserved by MP at 20°C showed significantly lower hepatic damage at the end of reperfusion compared with cold storage. GDH release was significantly reduced and bile production, ATP levels, GSH/GSSG and protein-SH groups were higher in livers preserved by MP at 20°C than with cold storage. The best preserved morphology and high glycogen content was obtained with livers submitted to MP at 20°C. Liver recovery using MP at 20°C was comparable to recovery with HBDs. MP at 20°C improves cell survival and gives a better-quality of preservation for livers obtained from NHBDs and may provide a new method for the successful utilization of marginal livers.

Human liver autofluorescence: an intrinsic tissue parameter discriminating normal and diseased conditions.

BACKGROUND AND OBJECTIVE: Autofluorescence (AF) emission is an intrinsic parameter that can provide real-time information on morpho-functional properties of biological tissue, being strictly related with their biochemical composition and structural organization. The diagnostic potentials of AF-based techniques have been investigated on normal, fibrotic, and steatotic liver tissues, in reference to histological features as evidenced by specific histochemical stainings. MATERIALS AND METHODS: AF emission under excitation at 366 nm has been examined on cryostatic tissue sections obtained from biopsies collected during surgical operation, by means of fluorescence imaging and microspectrofluorometric techniques. RESULTS: NAD(P)H, collagen, and vitamin A were found to be the endogenous fluorophores characterizing normal, fibrotic, and steatotic liver tissue AF, respectively. The differences of their photo-physical properties, in terms of emission amplitude, spectral shape, and response to irradiation, give rise to modifications of overall AF signal collected from tissues that allow the liver conditions to be distinguished. CONCLUSION: The study provides a valid premise for a development of AF-based optical biopsy techniques for a real-time discrimination of liver anatomo-pathological patterns.

Response to therapy as a criterion for awarding priority to patients with hepatocellular carcinoma awaiting liver transplantation.

BACKGROUND: How to prioritize patients with hepatocellular carcinoma (HCC) for liver transplantation (LT) remains controversial. This study was designed to assess the effectiveness of a policy for prioritizing HCC patients according to their response to pre-LT therapy. METHODS: The study period was from 2000 to 2008. Dropout criteria included macroscopic vascular invasion, metastases, and poorly differentiated grade at pre-LT biopsy. A specific treatment algorithm was adopted to treat HCC before LT, and the effect of treatment was evaluated 3 months after listing or after the diagnosis of HCC for patients diagnosed while already on the waiting list. Patients were divided into two groups: group 1, patients with disease that completely or partially responded to therapy; and group 2, patients with stable, progressive, or untreatable disease. Group 2 patients were prioritized for LT unless full restaging and repeat biopsy identified dropout criteria. RESULTS: At the 3-month visit, 62 HCC patients (42%) were assigned to group 2 and 85 (58%) to group 1. Eleven of 12 dropouts due to tumor progression came from group 2 (P < 0.01). Response to therapy was the sole predictor of dropout probability, independent of tumor stage (competing risk analysis). The 42 patients in group 2 who were transplanted had much the same 3-year post-LT survival rate as the 57 transplanted patients in group 1 (with survival rates of 82% and 83%, respectively; P > 0.05), but a slightly higher risk of post-LT HCC recurrence (13% and 2%, respectively; P = 0.04). CONCLUSIONS: Response to therapy is a potentially effective tool for prioritizing HCC patients for LT.

Different susceptibility of liver grafts from lean and obese Zucker rats to preservation injury.

We compared the susceptibility of liver grafts from lean and obese Zucker rats to preservation injury, using two organ-preservation techniques: conventional static preservation (SP) and machine perfusion (MP) preservation. SP: livers preserved by UW solution at 4, 8 or 20 degrees C for 6-h. MP: livers perfused for 6-h with an improved oxygenated Krebs-Henseleit solution (KH) at 4, 8 or 20 degrees C. Reperfusion with KH (2-h) was performed either with the SP or MP preserved livers. Fatty livers tolerate SP poorly at 4, 8 and 20 degrees C as compared with MP at the same temperatures. SP induced a decrease in the ATP/ADP ratio both at 8 and 20 degrees C in obese rats while an increase in energy status was found with MP at 8 and 20 degrees C. Nitrate/nitrite (NOx) concentration was higher and bile flow lower in livers preserved with SP than MP. In lean rats, no differences were observed between MP and SP as regards enzyme release, bile production and NOx levels except for SP at 20 degrees C in which high enzyme release and low bile flow were observed. In lean rats ATP/ADP was higher and NOx was lower with MP at 20 degrees C than with SP at 20 degrees C. To optimize steatotic liver preservation SP should be avoided because it is particularly detrimental as compared with MP.

Subnormothermic machine perfusion protects steatotic livers against preservation injury: a potential for donor pool increase?

We tested whether rat liver preservation performed by machine perfusion (MP) at 20 degrees C can enhance the functional integrity of steatotic livers versus simple cold storage. We also compared MP at 20 degrees C with hypothermic MP at 8 degrees C, and 4 degrees C. Obese and lean male Zucker rats were used as liver donors. MP was performed for 6 hours with a glucose and N-acetylcysteine-supplemented Krebs-Henseleit solution. Both MP and cold storage preserved livers were reperfused with Krebs-Henseleit solution (2 hours at 37 degrees C). MP at 4 degrees C and 8 degrees C reduced the fatty liver necrosis compared with cold storage but we further protected the organs using MP at 20 degrees C. Necrosis did not differ in livers from lean animals submitted to the different procedures; the enzymes released in steatotic livers preserved by MP at 20 degrees C were similar to those showed in nonsteatotic organs. The adenosine triphosphate/adenosine diphosphate ratio and bile production were higher and the oxidative stress and biliary enzymes were lower in steatotic livers preserved by MP at 20 degrees C as compared with cold storage. In livers from lean rats, the adenosine triphosphate/adenosine diphosphate ratio appears better conserved by MP at 20 degrees C as compared with cold storage. In steatotic livers preserved by cold storage, a 2-fold increase in tumor necrosis factor-alpha levels and caspase-3 activity was observed as compared with organs preserved by MP at 20 degrees C. These data are substantiated by better morphology, higher glycogen content, and lower reactive oxygen species production by sinusoidal cells in steatotic liver submitted to MP at 20 degrees C versus cold storage. MP at 20 degrees C improves cell survival and leads to a marked improvement in hepatic preservation of steatotic livers as compared with cold storage.