Tissue engineering and ex vivo gene therapy can be used synergically as tool to regenerate bone, which overcome the problems of currently available bone replacements. Recently, a new source of mesenchymal stromal cells (MSCs) has been found in the umbilical cord; human umbilical cord perivascular cells (HUCPVCs) provide an alternative to bone marrow derived MSCs and due to their easy harvest, fast expansion, and non-immunogeneic and immunomodulatory phenotype we hypothesized that HUCPVCs are a putative candidate cell source for osteogenic ex vivo gene therapy. This work proposes the generation of cocktails of genetically modified HUCPVCs and their cryopreservation as an “off the shelf” therapeutic. This approach involves the engineering of osteogenic cell populations, by genetically modifying HUCPVCs using recombinant adenoviruses to deliver four fundamental genes for bone formation: bone morphogenetic protein 2 (BMP-2), runt-related transcription factor 2 (Runx2), Osterix (OSX/SP7) transcription factor and vascular endothelial growth factor (VEGF). Our results show that HUCPVCs can be efficiently modified by adenoviruses and can be cryopreserved without affecting the production efficiency and bioactivity of proteins of interest produced by the cells. Moreover, overexpression of BMP2, Runx2 and SP7 enhances ALP activity levels in HUCPVCs and upregulates ALP, OPN, COL1A1 and OCN gene expression; data that provides the first evidence of the effects of combinational expression of BMP2, Runx2 and SP7. Furthermore, we report for the first time the genetic modification of human BMSCs to express SP7 and Runx2, which enhances their ALP activity and matrix mineralization capacity.

Title page, table of contents and abstract only. The complete thesis in print form is available from the University of Adelaide Library. / A range of epidemiological, clinical and experimental studies have demonstrated that exposure of an embryo to a suboptimal environment in vivo or ex vivo during early embryo development is associated with altered development of cardiovascular, neuroendocrine and metabolic disorders in adult life. A number of perturbations during early embryo development result in developmental adaptations by the embryo to ensure immediate survival, whilst programming the embryo for altered fetal and placental development, resulting in the eventual onset of adult disease. It has been previously shown that maternal nutrient restriction during the periconceptional period results in a hyperactivation of the pituitary - adrenal axis and increased mean arterial blood pressure in twin but not singleton pregnancies. It was therefore the first aim of this thesis to interrogate the impact of maternal undernutrition during the periconceptional period (defined as from at least 45 days prior until 7 days after conception) on fetal and placental development during early pregnancy at - day 55 of pregnancy, which coincides with the period of maximal placental growth. In Chapter 2, it has been demonstrated that there are important relationships between maternal weight gain during the periconceptional period and feto-placental growth during the first - 55 days of pregnancy and that periconceptional undernutrition has a differential effect on these relationships in singleton and twin pregnancies. In singleton pregnancies, periconceptional undernutrition disrupts the relationship between maternal weight gain during the periconceptional period and utero-placental growth and in twin pregnancies, periconceptional undernutrition results in the emergence of an inverse relationship between maternal weight gain during early pregnancy and uteroplacental growth and in a dependence of fetal growth on placental growth. (Chapter 2) In order to investigate the origins of the physiological adaptations that lead to the development of hyperactivation of the pituitary - adrenal axis and increased mean arterial blood pressure in late gestational fetuses after exposure as an embryo to periconceptional undernutrition, we investigated the development and steroidogenic capacity of the fetal adrenal gland and development of the fetal heart and kidney at - 55 days gestation (Chapter 3 and 4). The relative weight of the fetal adrenal and adrenal IGF-1, IGF-1 R, IGF-2, IGF-2R and CYP 17 mRNA expression were lower in twin compared to singleton fetuses. There was evidence that in control singletons, IGF-2R expression plays an important role in the regulation of adrenal growth and CYP 17 mRNA expression during early pregnancy. In control twins, however, whilst there was a significant positive relationship between adrenal CYP 17 and IGF-2 mRNA expression, adrenal weight was directly related to the level of adrenal IGF-1 mRNA expression. There was no effect of periconceptional undernutrition on the level of expression of any of the placental or adrenal genes in the study. In PCUN ewes, carrying singletons, however, there was a loss of the relationships between either adrenal IGF-2, IGF-2R and IGF-1 mRNA expression and adrenal growth and CYP 17 expression which were present in control singletons. Similarly in ewes carrying twins, maternal undernutrition during the periconceptional period resulted in the loss of the relationships between adrenal growth and IGF-1 expression and between _ adrenal CYP 17 and IGF-2 expression which were present in control twin fetuses. Whilst there was no effect of fetal number on fetal heart growth at - d55 in twin fetuses, there was a direct relationship between relative fetal heart and adrenal weights, which was present in both the PCUN and control groups. There was also a significant inverse relationship between maternal weight at conception and relative fetal heart weight in PCUN twin, but not PCUN singleton or control fetuses (Chapter 3). In control pregnancies maternal weight gain during the periconceptional period is inversely related to the relative weight of the fetal kidney at -55d pregnancy. In this group, relative kidney weight was also directly related to renal IGF-1 mRNA expression. In control twins maternal weight gain was inversely related to fetal kidney weight and this effect was ablated when the effects of maternal cortisol was controlled for in the analysis. In the PCUN group, whilst there was an inverse relationship between maternal weight gain during the periconceptional period and relative kidney weight, it was not possible to separate the independent effects of maternal weight loss during the periconceptional period and the subsequent weight gain during the period of refeeding. Renal IGF-1 mRNA expression was higher and renal lGF-1 R and 2R expression were lower in twin fetuses compared to singletons. After exposure to PCUN, renal IGF-1 expression was also higher than in control pregnancies independent of the fetal number (Chapter 4). Superovulation, artificial insemination, embryo transfer and in vitro embryo culture are used in a range of assisted reproductive technologies, and it has been demonstrated that varying the composition of the culture media can result in a change in pre and postnatal development. Culture of sheep embryos in media containing serum is associated with fetal overgrowth which is phenotypic of the Large Offspring Syndrome. It is not known how the combination of superovulation, artificial insemination and embryo transfer alone impacts fetoplacental development in late gestation of the sheep. There have been no studies, however, examining the differential impact of superovulation, artificial insemination and embryo transfer with or without in vitro embryo culture in the absence or presence of human serum on feto-placental development in Singleton and twin pregnancies (Chapter 5). I have therefore tested the hypothesis that superovulation, artificial insemination and embryo transfer with or without in vitro embryo culture in the presence or absence of human serum differentially alters the growth of the placenta, fetus and fetal organs during late gestation when compared to naturally conceived controls and that these effects are different in singleton and twin pregnancies. The fetal weight, CRL and abdominal circumference were significantly larger in IVCHS singleton fetuses. A novel finding in this study was lower fetal weights of twin fetuses in the ET and IVCNS groups compared to NM control twin fetuses. In addition, placental weights were lighter in twin fetuses in the ET, IVCNS and IVCHS treatment groups and this is partially due to a failure to initiate compensatory growth of placentomes in twin pregnancies (Chapter 5). The results of this thesis therefore highlight the complex interactions between the periconceptional environment (in vivo or ex vivo) and embryo or fetal number on the programming fetal and placental development. Maternal undernutrition during the periconceptional period and superovulation, artificial insemination and embryo transfer with or without in vitro culture in the absence or presence of serum alters fetal development, and I have demonstrated that these changes in fetal growth can be explained by changes in placental growth trajectory. Furthermore, a novel finding of this study is that perturbations of the periconceptional environment affect feto-placental development differently in singleton and twin pregnancies. / Thesis (Ph.D.) -- University of Adelaide, School of Molecular and Biomedical Science, 2006

Title page, table of contents and abstract only. The complete thesis in print form is available from the University of Adelaide Library. / A range of epidemiological, clinical and experimental studies have demonstrated that exposure of an embryo to a suboptimal environment in vivo or ex vivo during early embryo development is associated with altered development of cardiovascular, neuroendocrine and metabolic disorders in adult life. A number of perturbations during early embryo development result in developmental adaptations by the embryo to ensure immediate survival, whilst programming the embryo for altered fetal and placental development, resulting in the eventual onset of adult disease. It has been previously shown that maternal nutrient restriction during the periconceptional period results in a hyperactivation of the pituitary - adrenal axis and increased mean arterial blood pressure in twin but not singleton pregnancies. It was therefore the first aim of this thesis to interrogate the impact of maternal undernutrition during the periconceptional period (defined as from at least 45 days prior until 7 days after conception) on fetal and placental development during early pregnancy at - day 55 of pregnancy, which coincides with the period of maximal placental growth. In Chapter 2, it has been demonstrated that there are important relationships between maternal weight gain during the periconceptional period and feto-placental growth during the first - 55 days of pregnancy and that periconceptional undernutrition has a differential effect on these relationships in singleton and twin pregnancies. In singleton pregnancies, periconceptional undernutrition disrupts the relationship between maternal weight gain during the periconceptional period and utero-placental growth and in twin pregnancies, periconceptional undernutrition results in the emergence of an inverse relationship between maternal weight gain during early pregnancy and uteroplacental growth and in a dependence of fetal growth on placental growth. (Chapter 2) In order to investigate the origins of the physiological adaptations that lead to the development of hyperactivation of the pituitary - adrenal axis and increased mean arterial blood pressure in late gestational fetuses after exposure as an embryo to periconceptional undernutrition, we investigated the development and steroidogenic capacity of the fetal adrenal gland and development of the fetal heart and kidney at - 55 days gestation (Chapter 3 and 4). The relative weight of the fetal adrenal and adrenal IGF-1, IGF-1 R, IGF-2, IGF-2R and CYP 17 mRNA expression were lower in twin compared to singleton fetuses. There was evidence that in control singletons, IGF-2R expression plays an important role in the regulation of adrenal growth and CYP 17 mRNA expression during early pregnancy. In control twins, however, whilst there was a significant positive relationship between adrenal CYP 17 and IGF-2 mRNA expression, adrenal weight was directly related to the level of adrenal IGF-1 mRNA expression. There was no effect of periconceptional undernutrition on the level of expression of any of the placental or adrenal genes in the study. In PCUN ewes, carrying singletons, however, there was a loss of the relationships between either adrenal IGF-2, IGF-2R and IGF-1 mRNA expression and adrenal growth and CYP 17 expression which were present in control singletons. Similarly in ewes carrying twins, maternal undernutrition during the periconceptional period resulted in the loss of the relationships between adrenal growth and IGF-1 expression and between _ adrenal CYP 17 and IGF-2 expression which were present in control twin fetuses. Whilst there was no effect of fetal number on fetal heart growth at - d55 in twin fetuses, there was a direct relationship between relative fetal heart and adrenal weights, which was present in both the PCUN and control groups. There was also a significant inverse relationship between maternal weight at conception and relative fetal heart weight in PCUN twin, but not PCUN singleton or control fetuses (Chapter 3). In control pregnancies maternal weight gain during the periconceptional period is inversely related to the relative weight of the fetal kidney at -55d pregnancy. In this group, relative kidney weight was also directly related to renal IGF-1 mRNA expression. In control twins maternal weight gain was inversely related to fetal kidney weight and this effect was ablated when the effects of maternal cortisol was controlled for in the analysis. In the PCUN group, whilst there was an inverse relationship between maternal weight gain during the periconceptional period and relative kidney weight, it was not possible to separate the independent effects of maternal weight loss during the periconceptional period and the subsequent weight gain during the period of refeeding. Renal IGF-1 mRNA expression was higher and renal lGF-1 R and 2R expression were lower in twin fetuses compared to singletons. After exposure to PCUN, renal IGF-1 expression was also higher than in control pregnancies independent of the fetal number (Chapter 4). Superovulation, artificial insemination, embryo transfer and in vitro embryo culture are used in a range of assisted reproductive technologies, and it has been demonstrated that varying the composition of the culture media can result in a change in pre and postnatal development. Culture of sheep embryos in media containing serum is associated with fetal overgrowth which is phenotypic of the Large Offspring Syndrome. It is not known how the combination of superovulation, artificial insemination and embryo transfer alone impacts fetoplacental development in late gestation of the sheep. There have been no studies, however, examining the differential impact of superovulation, artificial insemination and embryo transfer with or without in vitro embryo culture in the absence or presence of human serum on feto-placental development in Singleton and twin pregnancies (Chapter 5). I have therefore tested the hypothesis that superovulation, artificial insemination and embryo transfer with or without in vitro embryo culture in the presence or absence of human serum differentially alters the growth of the placenta, fetus and fetal organs during late gestation when compared to naturally conceived controls and that these effects are different in singleton and twin pregnancies. The fetal weight, CRL and abdominal circumference were significantly larger in IVCHS singleton fetuses. A novel finding in this study was lower fetal weights of twin fetuses in the ET and IVCNS groups compared to NM control twin fetuses. In addition, placental weights were lighter in twin fetuses in the ET, IVCNS and IVCHS treatment groups and this is partially due to a failure to initiate compensatory growth of placentomes in twin pregnancies (Chapter 5). The results of this thesis therefore highlight the complex interactions between the periconceptional environment (in vivo or ex vivo) and embryo or fetal number on the programming fetal and placental development. Maternal undernutrition during the periconceptional period and superovulation, artificial insemination and embryo transfer with or without in vitro culture in the absence or presence of serum alters fetal development, and I have demonstrated that these changes in fetal growth can be explained by changes in placental growth trajectory. Furthermore, a novel finding of this study is that perturbations of the periconceptional environment affect feto-placental development differently in singleton and twin pregnancies. / Thesis (Ph.D.) -- University of Adelaide, School of Molecular and Biomedical Science, 2006

No description available.

Whilst the major caveat to the success of organ transplantation remains the severe lack of donor organs, rejection is still a primary confounding factor to transplant outcomes. This is an allospecific response that occurs when the recipient immune system recognises conserved proteins on donor-derived cells as 'non-self'. Currently, all immunosuppressive regimes target the recipient immune response, ignoring the large donor immune repertoire despite these cells playing a central role in acute rejection. This is likely as a result of a lack of understanding of the temporal migration of the donor compartment and its contribution to the inflammatory cascade that ensues. The development of ex vivo perfusion provides the opportunity to assess this in isolation, with no confounding factors. Furthermore, inducing the mobilisation of passenger leukocytes on an ex vivo circuit allows their removal prior to transplantation. Reducing the inflammatory burden of donor organs has the potential to impact on the clinical outcome of patients, manifesting as a reduction in the incidence or severity of acute rejection. The aim of this PhD thesis was to characterise the donor immune compartment of lungs and kidneys, to assess the impact of ex vivo perfusion on this, and determine the post-transplant impact of removing a proportion of these cells. For this purpose, donor lungs were perfused using ex vivo lung perfusion (EVLP) and the immune compartment characterised. A comparison of EVLP versus standard transplanted lungs was performed using a porcine transplant model. Clinical parameters were recorded and a histological assessment of cellular infiltration was performed to diagnose the incidence of acute rejection. To determine if these results were translatable to other organs, a porcine model of kidney ex vivo perfusion was established. In both models, a significant efflux of donor leukocytes was observed and inflammatory mediators detected. In a transplant model of EVLP, reducing the transfer of these passenger leukocytes translated into improved clinical outcomes, manifesting as a lower incidence of acute rejection, for animals receiving EVLP lungs compared to a standard transplant. Similar benefit is likely to occur following transplantation of perfused kidneys. This study describes for the first time the contribution of donor organs to the inflammatory processes that ensue following transplantation. It is clear that this untargeted population is of significant importance in clinical outcomes. Immunomodulatory strategies to alter the donor immune environment prior to transplantation therefore warrant development.

Umbilical cord blood (UCB) is a source of hematopoietic stem and progenitor cells (HSPC) used for allogeneic transplantation. Ex vivo expansion of HSPC can improve the slow platelet and neutrophil engraftment associated with UCB transplants. HSPCs reside in niches, some of which are near the endosteal bone surface, where they can associate with immature osteoblasts. Interestingly, osteoblasts can enhance the growth of HSPC in culture and their platelet engraftment activity. Using a proteomics approach, I identified 47 differentially expressed proteins between mesenchymal stem cells and immature osteoblasts. Several of these were previously implicated in HSPC maintenance such as IGF2, IGFBP2, DCN, GAS6 and VCAM1. Moreover, several other proteins belong to the alternative and classical complement pathways. Finally, I discovered that microvesicles found in osteoblast conditioned medium may also modulate the growth of HSPC, at least in ex vivo cultures.

Master of Science / Department of Electrical and Computer Engineering / Punit Prakash / Microwave ablation is clinically used to thermally ablate cancerous tissue in the liver and other organs. When treating large tumor volumes, physicians may use multiple antennas simultaneously. Multiple antennas can ablate a larger tissue volume while using the same total power as a single antenna. Pre-clinical simulation and experimental studies most often presume parallel insertion of antennas. However, due to anatomical constraints, such as the presence of ribs and the diaphragm, it is often challenging to insert antennas in a parallel fashion in practice. Previous studies have attempted to analyze the effect of non-parallel antenna insertion on ablation outcome using computational and experimental approaches; however, they were limited because they did not account for dynamic temperature-dependent changes in tissue electrical properties in simulations and employed limited experimental validation. In this thesis, we have developed improved models of multiple-antenna microwave ablation, including accounting for the effects of temperature-dependent changes in tissue properties. We have also developed a system for experimental assessment of ablation zone profiles in ex vivo tissues. By utilizing 3D printing, we have constructed a device to precisely position antennas within experimental tissue samples and allows for accurate sectioning of the ablation zone relative to the plane of antenna insertion. Furthermore, we implemented image processing techniques for quantifying the size and shape of experimental ablation zones. This enables more accurate and repeatable comparisons of ablation profiles between simulations and experiments. We found that for an inter-antenna spacing in the range of 10 – 20 mm, simulations and experiments indicated that the ablation zone volumes may change by up to 30% due to non-parallel antenna insertion.

Ce travail doctoral est consacré aux interactions entre la commande respiratoire et le désogestrel et son métabolite actif, l’étonogestrel. Le syndrome d’hypoventilation alvéolaire centrale congénitale (CCHS) est une pathologie neuro-respiratoire caractérisée par une absence de sensibilité à l’hypercapnie. Au sein du laboratoire, une observation a montré, chez deux patientes CCHS, une récupération de la chémosensibilité au CO2/H+ après exposition au désogestrel (Straus et al. 2010). Cependant, cette récupération n’étant pas systématique, il est important de caractériser les mécanismes d’action de ces molécules. Nous avons d’abord analysé rétrospectivement les variables respiratoires de base de ces deux patientes puis, chez le rongeur, utilisé différentes approches pharmacologiques et d’histologie fonctionnelle. Nous avons observé, chez les deux patientes CCHS, une augmentation de la fréquence respiratoire induite par le désogestrel. Chez l’animal, nous avons montré que l’étonogestrel exerçait un effet facilitateur bulbaire sur la fréquence respiratoire avec implication des systèmes sérotoninergiques. In vivo, l’étonogestrel exerce un effet dose-dépendant avec un effet facilitateur pour de faibles concentrations et un effet modérateur pour de plus fortes concentrations. D’autre part, nous avons montré que l’étonogestrel induit une potentialisation de la réponse à l’hypercapnie qui impliquerait des structures supra-bulbaires. Les résultats obtenus caractérisent les interactions de ce progestatif avec la commande respiratoire permettant d’ouvrir des perspectives quant aux conditions dans lesquelles des patients souffrant de ce syndrome pourraient recevoir ce progestatif dans le cadre d’un traitement. / The present doctoral work was investigated after clinical observations in patients suffering of congenital central alveolar hypoventilation syndrome (CCHS). This pathology is characterized by a decrease in the sensitivity to hypercapnia. In our laboratory, an observation shown, in such patients, a recovery of the chemosensibility to CO2/H+ after exposure to a gonane progestin, the desogestrel (Straus et al. 2010). However, this recovery was not systematic. So, it is important to characterize action mechanisms of etonogestrel, the active metabolite of the desogestrel. We retrospectively analyzed basal respiratory variables in the two CCHS patients include in the previous study (Straus et al. 2010) and used pharmacological and functional histological approaches on in vivo and ex vivo rodents. In both CCHS patients, we observed an increase in basal respiratory frequency induced by desogestrel. Results obtained in ex vivo central nervous system preparations highlighted, in normocapnia, a facilitatory effect of etonogestrel on the respiratory frequency involving medullary serotoninergic mechanisms. In vivo, this facilitatory effect is observed at 10-4/10-3mg/kg of etonogestrel but not at 1mg/kg, suggesting the activation of 1moderator mechanisms depending on supramedullary or peripheral systems. Furthermore, a potentiation of the respiratory response to hypercapnia was observed after exposure to etonogestrel. Data coming from ex vivo experiments pointed out the involvement of supramedullary areas. To conclude, whole of results reveal or characterize interactions of gonane progestin with the respiratory driveleading to perspectives for determining the conditions in which CCHS patients may receive this progestin for their treatment.

Small Intestinal Neuroendocrine Tumors (SI-NETs) are indolent neoplasms with an increasing annual incidence of approximately 1/100 000 people. They are often diagnosed at a late stage, restricting treatment efficacy. The aim of this thesis was to investigate clinical aspects of patients with advanced and/or disseminated disease with regard to clinical signs and management of abdominal fibrosis, the role of locoregional surgery and liver transplantation, as well as the ex vivo sensitivity of tumor samples to cytotoxic and targeted agents. Additionally, novel serum biomarkers for the diagnosis and prognosis of SI-NETs were investigated. In Paper I, abdominal fibrosis induced by serotonin and other cytokines from tumor cells, was associated with clinically significant symptoms of intestinal ischemia and/or obstructive uropathy, and was linked to advanced disease. Prompt recognition and minimally invasive intervention with superior mesenteric vein stenting and/or percutaneous nephrostomy and J stent treatment were effective in disease palliation. Paper II challenged the role of prophylactic, upfront locoregional surgery in Stage IV, which conferred no survival advantage in asymptomatic SI-NET patients. The option of delayed surgery as needed seemed to be comparable in all the outcomes examined, whilst also offering the advantage of fewer re-operations for intestinal obstruction in patients with already disseminated disease. Paper III confirmed that most young patients (<65 years) with SI-NET and liver metastases had a favorable survival with standardized multimodality treatment and that survival figures reported after liver transplantation for NETs do not surpass these figures. In Paper IV, 145 biomarkers were analyzed in blood serum using two different multiplex proximity assays. Subsequent ELISA and immunohistochemical analyses identified DcR3, TFF3 and midkine as novel serum biomarkers for SI-NETs. In Paper V, SI-NET samples were profiled with respect to sensitivity ex vivo to a panel of standard chemotherapeutics and targeted agents using a short-term total cell kill assay. SI-NETs exhibited variable but generally intermediate sensitivity ex vivo compared with other cancer diagnoses, calling for individualized selection of therapy.

Hjärtevaluering är avsett för att öka antalet transplanterade donerade hjärtan med målet att bli standardbehandling i samband med hjärttransplantation. Anledningen till behovet av hjärtevaluering är att samtidigt som människor dör i väntan på ett nytt hjärta så kasseras donerade hjärtan på grund av osäkerhet kring deras förmåga att skapa tillräckligt blodtryck och -flöde i mottagarens kropp.Detta arbete behandlar utveckling av koncept av en komponent i ett hjärtevalueringssystem som utvecklas av Igelösa Life Science AB. Komponenten är ett flödesmotstånd som kallas afterload och som används för att utvärdera ett donerat hjärtas förmåga att skapa blodtryck.Syftet med detta arbete är att förbättra användbarheten av hjärtevalueringssystemet för att öka antalet transplanterade hjärtan och på så vis rädda liv. Målet är att ta fram ett koncept för en afterload som har potential att lösa problem som identifierats under experimentella körningar av systemet. De huvudsakliga problemen är att en tillräcklig skillnad mellan det diastoliska och systoliska trycket inte kan uppnås samt och att afterloaden kräver en sterilklädd person för att styras.Arbetet resulterar i ett koncept som från utanför det sterila fältet som afterloaden verkar i kan styra flödesmotståndet och skapa flödesmotstånd som är tillräckligt för att utföra hjärtevaluering. Förslag på framtida arbete är att vidareutveckla konceptet genom att undersöka behov av övertrycksskydd i styrsystemet för flödesmotståndet samt att göra komponent- och materialval. / Today there are waiting lists for people in need of a heart through transplantation and every year people in these lists die due to deficiency of donated, transplantable hearts. Many of the hearts donated are discarded due to uncertainty regarding their condition, such hearts are called marginal hearts. The high number of marginal hearts have led Igelösa Life Science AB to develop a system for evaluating the actual performance of a donated heart ex vivo with the aim to prove transplantability of otherwise marginal hearts. The heart evaluation procedure is done in a stand-alone device prior to the implantation, and is to create proof of a donated heart's compatibility with the recipient. The proof comes mainly from the heart's ability to produce blood pressure.To simulate the arterial blood flow resistance, a component called afterload has been developed as a part of the heart evaluation system. It is connected to the outlets of an ex vivo heart. The aim with the heart evaluation procedure is to verify that the donated heart is in a sufficiently good condition to create blood pressure and flow in the recipient's body.The purpose of this work is to increase the number of donated hearts transplanted by improving the usability of the heart evaluation system. This work is focused on the afterload and aims to solve problems identified during experimental use, such as controllability of the flow resistance and making it controllable from outside the sterile field in which it operates.The work results in a concept for an afterload that controls the flow resistance by an adjustable volume which is mounted outside the sterile field. Further development of this concept might include component selection for the control system for the flow resistance and design of pressure relief that might be necessary.