Soluble macromolecules present in the tumour microenvironment (TME) alter the physical characteri... more Soluble macromolecules present in the tumour microenvironment (TME) alter the physical characteristics of the extracellular fluid and can affect cancer cell behaviour. A fundamental step in cancer progression is the formation of a new vascular network which may originate from both pre-existing normal endothelium and cancer-derived cells. To study the role of extracellular macromolecules in the TME affecting endothelial cells we exposed normal and cancer-derived endothelial cells to inert polymer solutions with different physicochemical characteristics. The cancer cell line SK-HEP-1, but not normal human umbilical vein endothelial cells, responded to high-macromolecular-content solutions by elongating and aligning with other cells, an effect that was molecular weight-dependent. Moreover, we found that neither bulk viscosity, osmotic pressure, nor the fractional volume occupancy of polymers alone account for the induction of these effects. Furthermore, these morphological changes were...
Vitrification of cells or tissue at controlled cooling rates suitable for larger volumes, and wit... more Vitrification of cells or tissue at controlled cooling rates suitable for larger volumes, and with reduced cryoprotectant toxicity. To set out the current understanding of the LiquidusTracking (LT) vitrification technique, and to discuss the challenges and benefits of translating the method into laboratory protocols more generally applicable to meet requirements of large volume and 3-D cryo-banking in the era of regenerative medicine. By adding small amounts of cryoprotectants at each step and subsequently cooling the sample just above its freezing point before further increasing CPA concentration, cryoprotectant toxicity is minimized. CPA toxicity can be reduced by lowering the temperature. Different manual approaches to LT were evaluated and further improved. Manual liquidus tracking is complicated and exhibits potential high variability. Nevertheless, this approach offers the possibility of testing several conditions simultaneously and could be used to pre-test conditions prior t...
Ischaemia reperfusion (IR) injury is a clinical entity with a major contribution to the morbidity... more Ischaemia reperfusion (IR) injury is a clinical entity with a major contribution to the morbidity and mortality of liver surgery and transplantation. A central pathway of protection against IR injury utilizes nitric oxide (NO). Nitric oxide synthase (NOS) enzymes manufacture NO from L-arginine. NO generated by the endothelial NOS (eNOS) isoform protects against liver IR injury, whereas inducible NOS (iNOS)-derived NO may have either a protective or a deleterious effect during the early phase of IR injury, depending on the length of ischaemia, length of reperfusion and experimental model. In late phase hepatic IR injury, iNOS-derived NO plays a protective role. In addition to NOS consumption of L-arginine during NO synthesis, this amino acid may also be metabolized by arginase, an enzyme whose release is increased during prolonged ischaemia, and therefore diverts L-arginine away from NOS metabolism leading to a drop in the rate of NO synthesis. NO most commonly acts through the soluble guanylyl cyclase-cyclic GMP- protein kinase G pathway to ameliorate hepatic IR injury. Both endogenously generated and exogenously administered NO donors protect against liver IR injury. The beneficial effects of NO on liver IR are not, however, universal, and certain conditions, such as steatosis, may influence the protective effects of NO. In this review, the evidence for, and mechanisms of these protective actions of NO are discussed, and areas in need of further research are highlighted.
Soluble macromolecules present in the tumour microenvironment (TME) alter the physical characteri... more Soluble macromolecules present in the tumour microenvironment (TME) alter the physical characteristics of the extracellular fluid and can affect cancer cell behaviour. A fundamental step in cancer progression is the formation of a new vascular network which may originate from both pre-existing normal endothelium and cancer-derived cells. To study the role of extracellular macromolecules in the TME affecting endothelial cells we exposed normal and cancer-derived endothelial cells to inert polymer solutions with different physicochemical characteristics. The cancer cell line SK-HEP-1, but not normal human umbilical vein endothelial cells, responded to high-macromolecular-content solutions by elongating and aligning with other cells, an effect that was molecular weight-dependent. Moreover, we found that neither bulk viscosity, osmotic pressure, nor the fractional volume occupancy of polymers alone account for the induction of these effects. Furthermore, these morphological changes were...
Vitrification of cells or tissue at controlled cooling rates suitable for larger volumes, and wit... more Vitrification of cells or tissue at controlled cooling rates suitable for larger volumes, and with reduced cryoprotectant toxicity. To set out the current understanding of the LiquidusTracking (LT) vitrification technique, and to discuss the challenges and benefits of translating the method into laboratory protocols more generally applicable to meet requirements of large volume and 3-D cryo-banking in the era of regenerative medicine. By adding small amounts of cryoprotectants at each step and subsequently cooling the sample just above its freezing point before further increasing CPA concentration, cryoprotectant toxicity is minimized. CPA toxicity can be reduced by lowering the temperature. Different manual approaches to LT were evaluated and further improved. Manual liquidus tracking is complicated and exhibits potential high variability. Nevertheless, this approach offers the possibility of testing several conditions simultaneously and could be used to pre-test conditions prior t...
Ischaemia reperfusion (IR) injury is a clinical entity with a major contribution to the morbidity... more Ischaemia reperfusion (IR) injury is a clinical entity with a major contribution to the morbidity and mortality of liver surgery and transplantation. A central pathway of protection against IR injury utilizes nitric oxide (NO). Nitric oxide synthase (NOS) enzymes manufacture NO from L-arginine. NO generated by the endothelial NOS (eNOS) isoform protects against liver IR injury, whereas inducible NOS (iNOS)-derived NO may have either a protective or a deleterious effect during the early phase of IR injury, depending on the length of ischaemia, length of reperfusion and experimental model. In late phase hepatic IR injury, iNOS-derived NO plays a protective role. In addition to NOS consumption of L-arginine during NO synthesis, this amino acid may also be metabolized by arginase, an enzyme whose release is increased during prolonged ischaemia, and therefore diverts L-arginine away from NOS metabolism leading to a drop in the rate of NO synthesis. NO most commonly acts through the soluble guanylyl cyclase-cyclic GMP- protein kinase G pathway to ameliorate hepatic IR injury. Both endogenously generated and exogenously administered NO donors protect against liver IR injury. The beneficial effects of NO on liver IR are not, however, universal, and certain conditions, such as steatosis, may influence the protective effects of NO. In this review, the evidence for, and mechanisms of these protective actions of NO are discussed, and areas in need of further research are highlighted.
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