Quantitative biology of single neurons

The building blocks of complex biological systems are single cells. Fundamental insights gained from single-cell analysis promise to provide the framework for understanding normal biological systems development as well as the limits on systems/cellular ability to respond to disease. The interplay of cells to create functional systems is not well understood. Until recently, the study of single cells has concentrated primarily on morphological and physiological characterization. With the application of new highly sensitive molecular and genomic technologies, the quantitative biochemistry of single cells is now accessible.     

Curcumin-Induced Heme Oxygenase-1 Expression Prevents H2O2-Induced Cell Death in Wild Type and Heme Oxygenase-2 Knockout Adipose-Derived Mesenchymal Stem Cells

Mesenchymal stem cell (MSC) administration is a promising adjuvant therapy to treat tissue injury. However, MSC survival after administration is often hampered by oxidative stress at the site of injury. Heme oxygenase (HO) generates the cytoprotective effector molecules biliverdin/bilirubin, carbon monoxide (CO) and iron/ferritin by breaking down heme. Since HO-activity mediates anti-apoptotic, anti-inflammatory, and anti-oxidative effects, we hypothesized that modulation of the HO-system affects MSC survival. Adipose-derived MSCs (ASCs) from wild type (WT) and HO-2 knockout (KO) mice were isolated and characterized with respect to ASC marker expression. In order to analyze potential modulatory effects of the HO-system on ASC survival, WT and HO-2 KO ASCs were pre-treated with HO-activity modulators, or downstream effector molecules biliverdin, bilirubin, and CO before co-exposure of ASCs to a toxic dose of H₂O₂. Surprisingly, sensitivity to H₂O₂-mediated cell death was similar in WT and HO-2 KO ASCs. However, pre-induction of HO-1 expression using curcumin increased ASC survival after H₂O₂ exposure in both WT and HO-2 KO ASCs. Simultaneous inhibition of HO-activity resulted in loss of curcumin-mediated protection. Co-treatment with glutathione precursor N-Acetylcysteine promoted ASC survival. However, co-incubation with HO-effector molecules bilirubin and biliverdin did not rescue from H₂O₂-mediated cell death, whereas co-exposure to CO-releasing molecules-2 (CORM-2) significantly increased cell survival, independently from HO-2 expression. Summarizing, our results show that curcumin protects via an HO-1 dependent mechanism against H₂O₂-mediated apoptosis, and likely through the generation of CO. HO-1 pre-induction or administration of CORMs may thus form an attractive strategy to improve MSC therapy.     

Simple mathematical model for predicting the transient behaviour of an ice-bank system

The time-variable performance of a Refrigerant 22 ice-bank system was simulated by a dynamic model which was derived by assuming that heat transfer was always the limiting process, and which thus ignored hydrodynamic processes. The model comprised four ordinary differential equations describing the position of the ice front, the water temperature, and the refrigerant evaporation and condensation temperatures, each of which was derived by energy balance, plus a number of algebraic equations. Measured plant performance was accurately predicted except immediately after start-up, and in circumstances in which the assumption that the dynamics of refrigerant flow did not exert any controlling influence on the overall process dynamics was inadequate (for example, when the thermostatic expansion valve operation becomes unstable). The model requires only data that should be readily available or can be easily estimated, and thus it is suitable for analyses in the design of ice bank systems to handle time-varying conditions. Simple dynamic models ignoring hydrodynamics can be adequate in circumstances where the main source of variation arises beyond the refrigeration circuit itself.     

Decellularised Human Umbilical Artery as a Vascular Graft Elicits Minimal Pro-Inflammatory Host Response Ex Vivo and In Vivo

Small diameter (<6 mm) vessel grafts still pose a challenge for scientists worldwide. Decellularised umbilical artery (dUA) remains promising as small diameter tissue engineered vascular graft (TEVG), yet their immunogenicity remains unknown. Herein, we evaluated the host immune responses, with a focus on the innate part, towards human dUA implantation in mice, and confirmed our findings in an ex vivo allogeneic human setup. Overall, we did not observe any differences in the number of circulating white blood cells nor the number of monocytes among three groups of mice (1) dUA patch; (2) Sham; and (3) Mock throughout the study (day −7 to 28). Likewise, we found no difference in systemic inflammatory and anti-inflammatory cytokine levels between groups. However, a massive local remodelling response with M2 macrophages were observed in the dUA at day 28, whereas M1 macrophages were less frequent. Moreover, human monocytes from allogeneic individuals were differentiated into macrophages and exposed to lyophilised dUA to maximize an eventual M1 response. Yet, dUA did not elicit any immediate M1 response as determined by the absence of CCR7 and CXCL10. Together this suggests that human dUA elicits a minimal pro-inflammatory response further supporting its use as a TEVG in an allogeneic setup.     

Effect of harvest date on the nutritional quality and antioxidant capacity in 'Hass' avocado during storage

The effect of harvest date on nutritional compounds and antioxidant activity (AOC) in avocado (Persea americana Mill. cv Hass) fruit during storage was determined. The fruits were harvested at seven different dates and ripened at 25 °C following 21 or 35 days of cold storage. The results indicated that the phenolic and glutathione contents were increased and the ascorbic acid content was not significantly different in early harvested fruit (January to March), and the phenolic, ascorbic acid and glutathione contents were increased slightly and then decreased on late harvested fruit (April to June). Similar trends were observed in the changes of AOC. Furthermore, AOC in early harvested fruit after storage for 35 days was much higher than that in late harvested fruit after storage for 21 days. Therefore, avocado can be harvested earlier for economic benefits according to the market and can keep high nutritional value for human health benefits.     

A model for communication of sensory quality in the seafood processing chain

Sensory quality has a key influence of consumer perception of a product. It is therefore of great importance for the processing industry that the sensory quality fulfils the expectations of the consumer. Sensory evaluations are the ultimate tool to measure and communicate sensory quality, but it is generally not fully implemented in the chain from catch to consumer. The importance of communicating sensory demands and results from evaluations in the seafood processing chain is described and a Seafood Sensory Quality Model (SSQM) is suggested as a communication tool.     

Proposing leading indicators for blood sampling: application of a method based on the principles of resilient healthcare

In recent years, healthcare has put a growing attention to the investigation of successful processes as a supplement to analyzing and investigating unwanted processes, like adverse events and near misses. This new perspective paves the way for developing methods and tools for investigating and understanding how processes function, and how variability can contribute to both success and failure. In the light of this, we have developed a method applicable for identifying leading indicators for successful outcomes of complex healthcare processes. The method, which is termed leading indicator identification method (LIIM) was inspired from similar methods applied in high-risk industries. To demonstrate the usefulness of the method we have conducted a case study with the aim of identifying leading indicators for blood sampling among patients in a Biomedical Department within a Danish hospital. The method builds on and uses steps from the functional resonance analysis method (FRAM). FRAM was developed to analyze how work is performed on a daily basis, in complex systems and can be used prospectively to monitor, manage and control such systems. The contribution of the work is to present the LIIM along with four leading indicators that are important to consider in the planning, management and monitoring of the blood sampling process.     

Water distribution in smoked salmon

Low‐field ¹H nuclear magnetic resonance (NMR) tranverse relaxations were measured on intact and minced muscle from raw and smoked salmon differing in size (small or large) and storage days after smoking (1, 11 and 20 days). Water distribution in the samples was calculated from the NMR signals by the use of multi‐way data analysis. For intact and minced salmon samples, three water ‘pools’ with T₂ values of 38, 50 and 182 ms and of 33, 50 and 183 ms, respectively, were identified. For both intact and minced samples, the size of water pool I and II were affected by storage time after smoking, whereas the size of pool III was affected by the size of the fish. Intact fillet samples taken near the skin and near the middle of the fillet differed with respect to shape of the NMR relaxation signal reflecting a non‐uniform distribution of the size of the three water pools in intact fillet. Copyright © 2006 Society of Chemical Industry