Conventional Cold Storage Research Articles

Ex Situ Liver Machine Perfusion as an Emerging Graft Protective Strategy in Clinical Liver Transplantation: the Dawn of a New Era.

The disparity between the number of available donor livers and patients awaiting a liver transplant has led transplant centers to accept suboptimal livers. There has been no universally accepted tool to predict the posttransplant function of these organs to safely increase the donor pool, protect these livers against ischemia-reperfusion injury, or improve their quality before implantation. Ex situ liver machine preservation has emerged as a promising novel graft protective strategy in the field of liver transplantation, with remarkable ongoing research and evolving clinical trials within Europe and the United States. This technology has been shown to be safe and feasible in the clinical liver transplantation field, has shown to reduce liver ischemia-reperfusion injury, and has shown to decrease the graft discard rate compared with conventional static cold storage. This review focuses on the current status of ex situ machine preservation in clinical liver transplantation, describing the most important technical aspects with the emphasis on the findings of the most recent clinical studies.

Hyperbaric Storage at Room Temperature for Fruit Juice Preservation

Hyperbaric storage is an innovative preservation method that consists of storing food under pressure, either at room or at low temperature, for time periods of days, weeks, or months. Recent scientific literature shows that hyperbaric storage at room temperature (HS-RT) could be an efficient method for fruit juice preservation. Depending on the level applied, pressure can inhibit and even inactivate the endogenous microflora of the fresh juice, while properly preserving other organoleptic and quality indicators. Even though the method has not yet been implemented in the food industry, its industrial viability has been evaluated from different points of view (product quality, consumer acceptation, vessel design, economic, or environmental, among others). The results reveal that HS-RT is effective in extending the shelf-life of both acidic and low-acidic fruit juices. Moreover, the energetic costs and the carbon footprint of HS-RT are considerably lower than those of refrigeration, therefore, HS-RT could be a reliable and environmentally friendly alternative to conventional cold storage. However, before industrial implementation, much more research is needed to clarify the effects of the storage conditions on the agents that cause fruit juice deterioration.

Machine Perfusion of Donor Heart: State of the Art

The purpose of this manuscript is to briefly review the past, present, and potential future of machine perfusion (MP) of the donor heart and to highlight its potentials to improve heart transplantation rates and outcomes. During the last few decades, the interests in MP has been raised. Experimental studies in animal and human models, together with clinical trials have provided robust evidence that MP may be considered as a better organ preservation method compared to conventional cold storage, as it avoids cold ischemia and maintains aerobic metabolism requirements of the donor heart. Evidence suggest that the dynamic platform in MP may offer an avenue to deliver reconditioning therapies during the preservation time. MP can preserve the donated heart in a beating, semi-physiologic dynamic status. It allows functional and metabolic evaluation, and reconditioning of dysfunctional donated hearts, and therefore may hold promise to expand the donor pool.

A Porcine Model Comparing NRP and Cold Storage versus NRP and Ex-Situ Perfusion in the Distant Procurement of DCD Hearts

Purpose Heart donation after circulatory death (DCD) has significantly improved organ utilisation with promising early outcomes. To date, adult DCD heart programmes have relied largely on ex-situ heart perfusion during transport of the donor organs even after normothermic regional perfusion (NRP) in the donor where the heart is formally assessed after circulatory arrest. In this pre-clinical porcine study we compare the use of cold storage as an alternative to ex-situ heart perfusion following NRP. Methods The porcine model of DCD was established with hypoxic arrest after baseline functional measurements were taken including thermo-dilution cardiac studies and pressure-volume loop measurements. Following mechanical asystole a fixed warm ischaemic period was allowed to model for the observation period and the time taken for transfer and access to the heart and major vessels in the clinical setting. NRP was established and the hearts perfused for 60 minutes before being weaned from NRP and functionally assessed. The hearts were then subject to cold storage (CS) with cardioprotective flush or ex-situ heart perfusion (ESHP) for 2 hours. The hearts were then functionally assessed on a left sided working rig with pressure-volume loop measurements. Results There were 5 animals in the NRP+CS and 6 in the NRP+ESHP groups respectively. All NRP+CS hearts and 5 out of the 6 NRP+ESHP were able to function in working mode for assessment on the rig with the left side loaded to a left atrial pressure of 20mmHg (Table 1). Conclusion These data suggest that NRP sufficiently resuscitates DCD hearts to allow for cold storage following functional assessment. In the porcine model, ESHP did not appear to offer any added advantage over conventional CS of 2 hours. Further work is required to determine the upper limit of cold ischaemic time that would be tolerated by the DCD heart and we should be cautious in extending CS until we have further information to guide us in the longer usage of CS after NRP.

Normothermic Machine Perfusion (NMP) Inhibits Proinflammatory Responses in the Liver and Promotes Regeneration.

Liver transplantation (LT) is a successful treatment for patients with liver failure. However, organ shortage results in over 11% of patients losing their chance of a transplant attributed to liver decompensation (LD) and death. Ischemia/reperfusion injury (IRI) following conventional cold storage (CS) is a major cause of injury leading to graft loss after LT. Normothermic machine perfusion (NMP), a method of organ preservation, provides oxygen and nutrition during preservation and allows aerobic metabolism. NMP has recently been shown to enable improved organ utilization and posttransplant outcomes following a phase I and a phase III randomized trial. The aim of the present study is to assess the impact of NMP on reducing IRI and to define the underlying mechanisms. We transplanted and compared 12 NMP with 27 CS-preserved livers by performing gene microarray, immunoprofiling of hepatic lymphocytes, and immunochemistry staining of liver tissues for assessing necrosis, platelet deposition, and neutrophil infiltration, and the status of steatosis after NMP or CS prereperfusion and postreperfusion. Recipients receiving NMP grafts showed significantly lower peak aspartate aminotransferase (AST) levels than those receiving CS grafts. NMP altered gene-expression profiles of liver tissue from proinflammation to prohealing and regeneration. NMP also reduced the number of interferon gamma (IFN-γ) and interleukin (IL)-17-producing T cells and enlarged the CD4pos CD25high CD127neg FOXP3pos regulatory T cell (Treg) pool. NMP liver tissues showed less necrosis and apoptosis in the parenchyma and fewer neutrophil infiltration compared to CS liver tissues. Conclusion: Reduced IRI in NMP recipients was the consequence of the combination of inhibiting inflammation and promoting graft regeneration.

Study protocol for a multicenter randomized controlled trial to compare the efficacy of end-ischemic dual hypothermic oxygenated machine perfusion with static cold storage in preventing non-anastomotic biliary strictures after transplantation of liver grafts donated after circulatory death: DHOPE-DCD trial

BackgroundThe major concern in liver transplantation of grafts from donation after circulatory death (DCD) donors remains the high incidence of non-anastomotic biliary strictures (NAS). Machine perfusion has been proposed as an alternative strategy for organ preservation which reduces ischemia-reperfusion injury (IRI). Experimental studies have shown that dual hypothermic oxygenated machine perfusion (DHOPE) is associated with less IRI, improved hepatocellular function, and better preserved mitochondrial and endothelial function compared to conventional static cold storage (SCS). Moreover, DHOPE was safely applied with promising results in a recently performed phase-1 study. The aim of the current study is to determine the efficacy of DHOPE in reducing the incidence of NAS after DCD liver transplantation.MethodsThis is an international multicenter randomized controlled trial. Adult patients (≥18 yrs. old) undergoing transplantation of a DCD donor liver (Maastricht category III) will be randomized between the intervention and control group. In the intervention group, livers will be subjected to two hours of end-ischemic DHOPE after SCS and before implantation. In the control group, livers will be subjected to care as usual with conventional SCS only. Primary outcome is the incidence of symptomatic NAS diagnosed by a blinded adjudication committee. In all patients, magnetic resonance cholangiography will be obtained at six months after transplantation.DiscussionDHOPE is associated with reduced IRI of the bile ducts. Whether reduced IRI of the bile ducts leads to lower incidence of NAS after DCD liver transplantation can only be examined in a randomized controlled trial.Trial registrationThe trial was registered in Clinicaltrials.gov in September 2015 with the identifier NCT02584283.

Mild hypothermia during the reperfusion phase protects mitochondrial bioenergetics against ischemia-reperfusion injury in an animal model of ex-vivo liver transplantation-an experimental study.

The organ preservation paradigm has changed following the development of new ways to preserve organs. The use of machine perfusion to preserve organs appears to have several advantages compared with conventional static cold storage. For liver transplants, the temperature control provided by machine perfusion improves organ preservation. In this experimental study, we measured the effects of different temperatures on mitochondrial bioenergetics during the reperfusion phase. An experimental model of ex-vivo liver transplantation was developed in Wistar rats (Rattus norvegicus). After total hepatectomy, cold static preservation occurred at 4ºC and reperfusion was performed at 37ºC and 32ºC using a Langendorff system. We measured parameters associated with mitochondrial bioenergetics in the livers. Compared with the livers that underwent normothermic reperfusion, mild hypothermia during reperfusion caused significant increases in the mitochondrial membrane potential, the adenosine triphosphate content, and mitochondrial respiration, and a significant reduction in the lag phase (all P < 0.001). Mild hypothermia during reperfusion reduced the effect of ischemia-reperfusion injury on mitochondrial activity in liver tissue and promoted an increase in bioenergetic availability compared with normothermic reperfusion.

Opposite acute potassium and sodium shifts during transplantation of hypothermic machine perfused donor livers.

Liver transplantation is frequently associated with hyperkalemia, especially after graft reperfusion. Dual hypothermic oxygenated machine perfusion (DHOPE) reduces ischemia/reperfusion injury and improves graft function, compared to conventional static cold storage (SCS). We examined the effect of DHOPE on ex situ and in vivo shifts of potassium and sodium. Potassium and sodium shifts were derived from balance measurements in a preclinical study of livers that underwent DHOPE (n = 6) or SCS alone (n = 9), followed by ex situ normothermic reperfusion. Similar measurements were performed in a clinical study of DHOPE‐preserved livers (n = 10) and control livers that were transplanted after SCS only (n = 9). During DHOPE, preclinical and clinical livers released a mean of 17 ± 2 and 34 ± 6 mmol potassium and took up 25 ± 9 and 24 ± 14 mmol sodium, respectively. After subsequent normothermic reperfusion, DHOPE‐preserved livers took up a mean of 19 ± 3 mmol potassium, while controls released 8 ± 5 mmol potassium. During liver transplantation, blood potassium levels decreased upon reperfusion of DHOPE‐preserved livers while levels increased after reperfusion of SCS‐preserved liver, delta potassium levels were ‐0.77 ± 0.20 vs. +0.64 ± 0.37 mmol/L, respectively (P = .002). While hyperkalemia is generally anticipated during transplantation of SCS‐preserved livers, reperfusion of hypothermic machine perfused livers can lead to decreased blood potassium or even hypokalemia in the recipient.

Outcomes of DCD liver transplantation using organs treated by hypothermic oxygenated perfusion before implantation

Donation after circulatory death (DCD) liver transplantation is known for potentially worse outcomes because of higher rates of graft non-function or irreversible cholangiopathy. The impact of machine liver perfusion techniques on these complications remains elusive. We aimed to provide data on 5-year outcomes in patients receiving DCD liver transplants, after donor organs had been treated by hypothermic oxygenated perfusion (HOPE). Fifty HOPE-treated DCD liver transplants performed in Zurich between 2012 and 3/2017 were matched with 50 primary donation after brain death (DBD) liver transplants, and with 50 untreated DCD liver transplants in Birmingham. Match factors focussed on short cold ischaemia, comparable recipient age and low recipient laboratory model for end-stage liver disease scores. Primary endpoints were post-transplant complications, and non-tumour-related patient death or graft loss. Despite extended donor warm ischaemia, HOPE-treated DCD liver transplants achieved similar overall graft survival, compared to standard DBD liver transplants. Particularly, graft loss due to any non-tumour-related causes occurred in 8% (4/50) of cases. In contrast, untreated DCD livers resulted in non-tumour-related graft failure in one-third (16/50) of cases (p = 0.005), despite significantly (p <0.001) shorter functional donor warm ischaemia. Five-year graft survival, censored for tumour death, was 94% for HOPE-treated DCD liver transplants vs. 78% in untreated DCD liver transplants (p = 0.024). The 5-year outcomes of HOPE-treated DCD liver transplants were similar to those of DBD primary transplants and superior to those of untreated DCD liver transplants, despite much higher risk. These results suggest that a simple end-ischaemic perfusion approach is very effective and may open the field for safe utilisation of extended DCD liver grafts. Machine perfusion techniques are currently being introduced into the clinic, with the aim of optimising injured grafts prior to implantation. While short-term effects of machine liver perfusion have been frequently reported in terms of hepatocellular enzyme release and early graft function, the long-term benefit on irreversible graft loss has been unclear. Herein, we report on 5-year graft survival in donation after cardiac death livers, treated either by conventional cold storage, or by 1-2 h of hypothermic oxygenated perfusion (HOPE) after cold storage. Graft loss was significantly less in HOPE-treated livers, despite longer donor warm ischaemia times. Therefore, HOPE after cold storage appears to be a simple and effective method to treat high-risk livers before implantation.

Machine perfusion for liver transplantation in the era of marginal organs-New kids on the block.

In the face of a critical organ shortage in the Western world, various strategies are employed to expand the donor pool for orthotopic liver transplantation (OLT). Among them is the transplantation of organs from extended criteria donors, a valuable source of liver allografts, however, characterized by potential risks for post-OLT complications and inferior outcomes. In recent years, machine perfusion (MP) of the explanted donor liver as well as regional perfusion techniques has witnessed significant advancements. Here, we aim to discuss different modes of dynamic organ preservation in OLT. These include hypothermic and normothermic MP, hypothermic oxygenated machine perfusion (HOPE), controlled oxygenated rewarming as well as regional perfusion protocols. Over recent years, multiple feasibility trials have demonstrated the clinical prospects of MP. In the context of OLT using organs from extended criteria donors, MP has numerous advantages compared to conventional cold storage, some of which include the preservation and reconditioning of borderline transplantable organs and the viability assessment of high-risk donor allografts. This review aims to address the topic of liver allograft MP, highlighting particularly the current trends in clinical applications and future perspectives. Furthermore, different approaches of liver storage and reconditioning are reviewed in the context of ongoing research.

Research Highlights

Improving the Supply and Quality of Deceased-Donor Organs for Transplantation Tullius SG, Rabb H. N Engl J Med. 2018;378:1920-1929. A timely review article, summarizing the potential improvements that can be made to decrease the discard rate of deceased-donor organs. Deceased-donor organs are generally discarded if considered suboptimal. The Kidney Donor Risk Profile Index is widely used to predict outcome, and a score of 85% or more are discarded frequently. Using these organs will particularly impact on the highly sensitized patients, as well as patients who are on the waiting list for more than 10 years. A variety of reasons can deem the organ unsuitable, from older-age donors to infectious risk or increased warm ischemic time. The authors point out that with death rates between 20% and 40% on the waiting list, it is time for clinicians to think of innovative ways to deal with these suboptimal organs and to reduce the discard rate. Although age is not limiting donor utilization in countries like Spain, there are several places elsewhere in the world where donors older than 65 or 70 years might not be used. Spanish results with older donors are not yet well reported, although we know, in general, that using these kidneys for older recipients result in better outcomes.1 Eliminating harmful senescent cells, which are more prevalent in older organs, might improve organ function. This is a potential research area that needs to be developed in more detail. Similarly, new preservation methods have the option to improve organs retrieved from donors after circulatory death and normothermic perfusion will hopefully impact positively to reduce discard rates from donors after circulatory death organs. Lastly, the authors point out that donors with high infectious risk can successfully be used, including hepatitis C virus– and human immunodeficiency virus–positive organs. The key is probably to select the best recipient for all these organs and to adjust regulatory frameworks to allow for a wider use of discarded organs. A huge potential exists to improve organ quality in the brain-dead donor, including improved hemodynamic stabilization, hormonal factors, and metabolic factors. REFERENCE Tullius SG, Milford E. Kidney allocation and the aging immune response. N Engl J Med. 2011;364:1369–1370. A Randomized Trial of Normothermic Preservation in Liver Transplantation Nasralla D, Coussio CC, Mergental H, et al. Nature. 2018;557:50-56. Suboptimal livers do not tolerate conventional cold storage very well and organ viability is difficult to assess. In this study, 334 livers were randomized to 2 groups. In the first group, 170 livers were perfused with oxygenated blood, medications, and nutrients at normal body temperature (normothermic machine perfusion [NMP]). In the second group, 164 livers were allocated to static cold storage (SCS). Livers donated after circulatory death (DCD), as well as livers from brain-dead donors (DBD), were allowed into the study. The discard rate in the SCS group was 24.1% compared with the 11.7% in the NMP arm. Peak aspartate aminotransferase AST was reduced by 49.4% in the NMP arm at day 7 compared with the SCS arm. There was no significant difference in the rate of nonanastomotic bile duct strictures for DBD livers (NMP, 7.4% vs SCS, 5.4%). The DCD liver donors represent a large untapped source of organ donors worldwide and had been used less often because of increased risk of ischemic cholangiopathy compared with DBD livers.1 The effects of NMP demonstrated in this study are unequivocal with respect to the primary endpoint, implying a benefit in livers currently used for transplantation. However, the greatest benefit may be realized by applying this technology to livers outside current acceptance criteria, to transplant organs currently deemed untransplantable. REFERENCE Jay CL, Lyuksemburg V, Ladner DP, et al. Ischemic cholangiopathy after controlled donation after cardiac death liver transplantation: a meta-analysis. Ann Surg. 2011;253:259–264.

A randomized trial of normothermic preservation in liver transplantation.

Liver transplantation is a highly successful treatment, but is severely limited by the shortage in donor organs. However, many potential donor organs cannot be used; this is because sub-optimal livers do not tolerate conventional cold storage and there is no reliable way to assess organ viability preoperatively. Normothermic machine perfusion maintains the liver in a physiological state, avoids cooling and allows recovery and functional testing. Here we show that, in a randomized trial with 220 liver transplantations, compared to conventional static cold storage, normothermic preservation is associated with a 50% lower level of graft injury, measured by hepatocellular enzyme release, despite a 50% lower rate of organ discard and a 54% longer mean preservation time. There was no significant difference in bile duct complications, graft survival or survival of the patient. If translated to clinical practice, these results would have a major impact on liver transplant outcomes and waiting list mortality.

Hypothermic oxygenated machine perfusion (HOPE) for orthotopic liver transplantation of human liver allografts from extended criteria donors (ECD) in donation after brain death (DBD): a prospective multicentre randomised controlled trial (HOPE ECD-DBD)

IntroductionOrthotopic liver transplantation (OLT) has emerged as the mainstay of treatment for end-stage liver disease. In an attempt to improve the availability of donor allografts and reduce waiting list mortality,...

Machine Perfusion at 20°C Prevents Ischemic Injury and Reduces Hypoxia-Inducible Factor-1α Expression During Rat Liver Preservation.

BACKGROUND Ischemic cholangitis is the main cause of liver failure after transplantation and subnormothermic machine perfusion may represent a better strategy than conventional cold storage, minimizing preservation injury. We compared livers preserved by machine perfusion at 20°C (MP20) or by cold storage at 4°C (CS4) with regard to hypoxia-inducible factor (HIF)-1α mRNA expression and protein stabilization in hypoxic conditions. MATERIAL AND METHODS Livers from male Wistar rats were stored on ice at 4°C in UW solution (CS4) or perfused with oxygenated Krebs-Henseleit buffer at 20°C (MP20) for six hours. After preservation, the livers were reperfused for two hours with oxygenated Krebs-Henseleit buffer at 37°C to simulate reimplantation. We collected bile, perfusate, and tissue samples. Transaminases, lactate dehydrogenase, bilirubin, and lactic acid were assayed in the perfusate and bile. ATP/ADP, glycogen, HIF-1α mRNA, and protein expression were measured in the tissue homogenates. RESULTS At the end of preservation, as well as after reperfusion, HIF-1α mRNA expression was significantly higher in the ischemic CS4 livers. Although the hypoxic conditions found in CS4 preservation stabilized HIF-1α protein was significantly higher in the CS4 livers at the end of preservation, no difference was observed after reperfusion, likely because of the oxygen in the reperfusion medium. After reperfusion, the MP20 livers released less transaminases and LDH. The MP20 livers had higher ATP/ADP, glycogen, and biliary bilirubin after both preservation and reperfusion when compared with the CS4 livers. CONCLUSIONS The data demonstrated that MP20 was associated with a lower HIF-1α expression and organ injury with respect to CS4, suggesting that oxygen provided by this preservation setting might approximate the organ request, thus avoiding the ischemic injury usually observed during organ preservation by cold storage.

Role of temperature in reconditioning and evaluation of cold preserved kidney and liver grafts.

Purpose of reviewOrgan shortage in transplantation medicine forces surgical research toward the development of more efficient approaches in organ preservation to enable the application of ‘less than optimal’ grafts. This review summarizes current techniques aiming to recondition cold-stored organ grafts prior to transplantation to reduce reperfusion-induced tissue injury and improve postimplantation graft function.Recent findingsEnd-ischemic reconditioning has classically been attempted by cold oxygenated perfusion. By contrast, evaluation of graft performance prior to transplantation might be facilitated by perfusion at higher temperatures, ideally at normothermia. A drastic temperature shift from cold preservation to warm perfusion, however, has been incriminated to trigger a so-called rewarming injury associated with mitochondrial alterations. A controlled gradual warming up during machine perfusion could enhance the restitution of cellular homeostasis and improve functional outcome upon warm reperfusion.SummaryMachine perfusion after conventional cold storage is beneficial for ulterior function after transplantation. Cold grafts should be initially perfused at low temperatures allowing for restitution of cellular homeostasis under protective hypothermic limitation of metabolic turnover. Delayed slow rewarming of the organ might further mitigate rewarming injury upon reperfusion and also increases the predictive power of evaluative measures, taken during pretransplant perfusion.

Normothermic ex-situ liver preservation: the new gold standard.

Normothermic machine perfusion of the liver (NMP-L) is a novel technology recently introduced into the practice of liver transplantation. This review recapitulates benefits of normothermic perfusion over conventional static cold storage and summarizes recent publications in this area. The first clinical trials have demonstrated both safety and feasibility of NMP-L. They have shown that machine perfusion can entirely replace cold storage or be commenced following a period of cold ischaemia. The technology currently allows transplant teams to extend the period of organ preservation for up to 24 h. Results from the first randomized control trial comparing NMP-L with static cold storage will be available soon. One major advantage of NMP-L technology over other parallel technologies is the potential to assess liver function during NMP-L. Several case series have suggested parameters usable for liver viability testing during NMP-L including bile production and clearance of lactic acidosis. NMP-L allows viability testing of high-risk livers. It has shown the potential to increase utilization of donor organs and improve transplant procedure logistics. NMP-L is likely to become an important technology that will improve organ preservation as well as have the potential to improve utilization of extended criteria donor livers.

Opportunities for Therapeutic Intervention During Machine Perfusion.

There is a vast discrepancy between the number of patients waiting for organ transplantation and the available donor organs. Ex vivo machine perfusion (MP) has emerged in an effort to expand the donor pool, by improving organ preservation, providing diagnostic information, and more recently, acting as a platform for organ improvement. This article reviews the current status of MP with a focus on its role in organ preconditioning and therapeutic interventions prior to transplantation. MP has allowed longer organ preservation compared to conventional static cold storage and allowed the use of organs that might otherwise have been discarded. Moreover, experimental studies have investigated the role of MP in reducing ischemia reperfusion injury of lungs, kidneys and livers by applying mesenchymal stem cells (MSCs), anti-inflammatory agents, cytotopic anticoagulants, and defatting cocktails. MP has opened a new era in the field of organ transplantation and tissue medication.

Acellular Hypothermic Extracorporeal Perfusion Extends Allowable Ischemia Time in a Porcine Whole Limb Replantation Model.

One of the major challenges in traumatic amputation is the need to keep ischemia time brief (4 to 6 hours) to avoid ischemic damage and enable successful replantation. The current inability to meet this challenge often leads to traumatic limb loss, which has a considerable detrimental impact on the quality of life of patients. The authors' team built a portable extracorporeal membrane oxygenator device for the perfusion of amputated extremities with oxygenated acellular solution under controlled parameters. The authors amputated forelimbs of Yorkshire pigs, perfused them ex vivo with acellular Perfadex solution for 12 hours at 10°C in their device, and subsequently replanted them into the host animal. The authors used limbs stored on ice slurry for 4 hours before replantation as their control group. Clinical observation and histopathologic evaluation both demonstrated that there was less morbidity and less tissue damage to the cells during preservation and after replantation in the perfusion group compared with the standard of care. Significant differences in blood markers of muscle damage and tissue cytokine levels underscored these findings. The authors demonstrated the feasibility and superiority of ex vivo hypothermic oxygenated machine perfusion for preservation of amputated limbs over conventional static cold storage and herewith a substantial extension of the allowable ischemia time for replantation after traumatic amputation. This approach could also be applied to the field of transplantation, expanding the potential pool of viable donor vascularized composite allografts.

‘SCS421 CAROLINA’, FIRST JAPANESE PEAR CULTIVAR DEVELOPED IN BRAZIL

ABSTRACT The new SCS421 Carolina cultivar, belonging to the Pyrus pyrifolia var. culta species, is classified as an Asian pear type or more specifically Japanese pear type. It was obtained from the Kousui x Osanijisseiki crossing made at Epagri / Caçador Experimental Station. Its flowering occurs from the second half of September to mid-October, similarly to Housui cultivar. According to preliminary results, ‘Yali’ and ‘Housui’ may be used as pollinators. The harvest takes place in the first half of February and production is above 20 t / ha. Plants produce more rounded and symmetrical fruits compared to Housui cultivar. The fruit skin is golden, the pulp is crispy, soft, sweet, very juicy and slightly aromatic. Fruits can be stored for up to four months in conventional cold storage. The incidence of scabies and dry branch diseases in the field has not been recorded. It is recommended for cultivation at colder regions of southern Brazil.

Hyperbaric cold storage versus conventional refrigeration for extending the shelf-life of hake loins

Today, extending the shelf-life of fish, while retaining the organoleptic properties of the product, is still a challenge. To compare the effectiveness of conventional and hyperbaric cold storage in preserving fish quality, we stored Cape hake loins at 5 °C, both at atmospheric pressure and at 50 MPa. After 7 days of storage, microbial counts and total volatile basic-nitrogen content in conventionally refrigerated samples exceeded the limits recommended for consumption. By contrast, hyperbaric cold storage maintained these parameters unaltered, although it produced drip losses close to 5% and increased the shear resistance and whiteness of the raw samples by 44% and 9%, respectively. Nevertheless, after cooking, weight losses were less than half of those of the control loins and whiteness differences disappeared. Consequently, the sensorial analysis could only find moderate differences between the samples before and after hyperbaric storage. These results clearly prove that hyperbaric cold storage was more efficient than conventional refrigeration for the preservation of hake loins. Hyperbaric cold storage opens interesting new doors for the fish-processing industry. Thus, it could be employed in different sections of the cold chain: on board, immediately after caught; at the food industry, during processing; on ship or trunk transport for long-distance markets; at school or hospital kitchens; at restaurants; or even at home. The increased cost resulting from hyperbaric storage should be overcome by an extended shelf life of a high-quality product.