Exogenous hydrogen sulfide gas does not induce hypothermia in normoxic mice.

Hydrogen sulfide (HS, 80 ppm) gas in an atmosphere of 17.5% oxygen reportedly induces suspended animation in mice; a state analogous to hibernation that entails hypothermia and hypometabolism. However, exogenous HS in combination with 17.

Protective Mechanisms of Hypothermia in Liver Surgery and Transplantation.

Hepatic ischemia/reperfusion (I/R) injury is a side effect of major liver surgery that often cannot be avoided. Prolonged periods of ischemia put a metabolic strain on hepatocytes and limit the tolerable ischemia and preservation times during liver resection and transplantation, respectively. In both surgical settings, temporarily lowering the metabolic demand of the organ by reducing organ temperature effectively counteracts the negative consequences of an ischemic insult.

The physiology of artificial hibernation.

Incomplete understanding of the mechanisms responsible for induction of hibernation prevent translation of natural hibernation to its artificial counterpart. To facilitate this translation, a model was developed that identifies the necessary physiological changes for induction of artificial hibernation. This model encompasses six essential components: metabolism (anabolism and catabolism), body temperature, thermoneutral zone, substrate, ambient temperature, and hibernation-inducing agents.

Survey and critical appraisal of pharmacological agents with potential thermo-modulatory properties in the context of artificially induced hypometabolism.

A reduction in body temperature can be achieved by a downward adjustment of the termoneutral zone, a process also described as anapyrexia. Pharmacological induction of anapyrexia could enable numerous applications in medicine. However, little is known about the potential of pharmacological agents to induce anapyrexic signaling.

Absence of hydrogen sulfide-induced hypometabolism in pigs: a mechanistic explanation in relation to small nonhibernating mammals.

Artificially induced hypometabolism in nonhibernating mammals may have considerable clinical implications. Numerous studies in small rodent models have demonstrated that hydrogen sulfide (H2S) induces hypometabolism, supposedly as a result of histotoxic hypoxia. However, the induction of hypometabolism is absent in large animals following H2S administration.

Efficacy of liver graft washout as a function of the perfusate, pressure, and temperature.

Donor graft washout can be impaired by colloids in organ preservation solutions that increase the viscosity and agglutinative propensity of red blood cells (RBCs) and potentially decrease organ function. The colloid-induced agglutinative effects on RBCs and RBC retention after liver washout with Ringer's lactate (RL), histidine tryptophan ketoglutarate solution, University of Wisconsin solution, and Polysol were determined as a function of the washout pressure (15 or 100 mm Hg) and temperature (4 or 37°C) in a rat liver washout model with (99m) Tc-pertechnetate-labeled RBCs. Colloids (polyethylene glycol in Polysol and hydroxyethyl starch in University of Wisconsin) induced RBC agglutination, regardless of the solution's composition.

A novel oxygenated machine perfusion system for preservation of the liver.

Machine perfusion (MP) is a potential method to increase the donor pool for organ transplantation. However, MP systems for liver grafts remain difficult to use because of organ-specific demands. Our aim was to test a novel, portable MP system for hypothermic preservation of the liver.

Optimal flow and pressure management in machine perfusion systems for organ preservation.

Intra-organ flow is the most critical parameter in machine-perfused organ preservation systems (MPS). Ultrasonic flow sensors (UFS) are commonly employed in MPS. However, UFS are sensitive to changes in fluid composition and temperature and require recalibration.

Appraisal of the porcine kidney autotransplantation model.

Animal models are extensively used for transplantation related research, especially kidney transplantation. Porcine autotransplantation models are considered to be favorable regarding translatability to the human setting. The key determinants for translatability of the model are discussed, comprising animal age, development, anatomy, anesthesia and surgical protocols, and perioperative care.

Surgical injuries of pancreatic allografts during procurement.

Quality of most procured pancreata is considered acceptable or good by surgeons, but remains difficult to ascertain. Little is known on how often pancreata are refused for transplantation during back-table inspection. Purpose of this study was to determine the frequency and type of problems responsible for refusal during back-table inspection and to identify possible risk factors.