Three-dimensional cell culture and tissue engineering in a T-CUP (tissue culture under perfusion)

The aim of this study was to develop and validate a simple and compact bioreactor system for perfusion cell seeding and culture through 3-dimensional porous scaffolds. The developed Tissue Culture Under Perfusion (T-CUP) bioreactor is based on the concept of controlled and confined alternating motion of scaffolds through a cell suspension or culture medium, as opposed to pumping of the fluid through the scaffolds. Via the T-CUP, articular chondrocytes and bone marrow stromal cells could be seeded into porous scaffolds of different compositions and architectures (chronOS, Hyaff-11, and Polyactive) at high efficiency (greater than 75%), uniformity (cells were well distributed throughout the scaffold pores), and viability (greater than 97%). Culture of articular chondrocytes seeded into 4-mm thick Polyactive scaffolds for 2 weeks in the T-CUP resulted in uniform deposition of cartilaginous matrix. Cultivation of freshly isolated human bone marrow nucleated cells seeded into ENGipore ceramic scaffolds for 19 days in the T-CUP resulted in stromal cell-populated constructs capable of inducing ectopic bone formation in nude mice. The T-CUP bioreactor represents an innovative approach to simple, efficient, and reliable 3D cell culture, and could be used either as a model to investigate mechanisms of tissue development or as a graft manufacturing system in the context of regenerative medicine

Upgrade of the SPS extraction Kickers for LHC and CNGS Operation

The extraction kickers of the Super Proton Synchrotron (SPS) need to be upgraded to meet the Large Hadron Collider (LHC) and CERN Neutrino to Grand Sasso (CNGS) requirements. Commissioning of the extraction towards one of the LHC rings and the CNGS facility under construction is foreseen for 2003. The ferrites of the kicker magnets will be heated significantly by the circulating beam and need to be cooled to stay below the Curie temperature. A cost-effective solution to this problem is presented consisting of AlN water cooled plates on the top and bottom of the ferrites. Model predictions are compared with preliminary laboratory measurements and machine data from the SPS. Commissioning of the extraction towards the other LHC ring is planned for 2006. Beyond the heat load issues, this latter extraction needs a larger horizontal "kick" and thus a higher magnetic field and larger horizontal beam aperture. The rise and fall time requirements of these kickers are less strict, therefore a new system with lower impedance permitting a larger magnetic field can be used

Dietary value for money? Investigating how the monetary value of diets in the National Diet and Nutrition Survey (NDNS) relate to dietary energy density

Estimating the monetary value of individuals’ diets allows investigation into how costs relate to dietary quality. A number of studies(1–2), including one in Scotland(3), have reported a strong negative relationship between diet costs and energy density. Most studies of this type neglect to address the issue of mathematical coupling, where energy is both the numerator in the energy density variable (kJ/g) and the denominator in energy-adjusted diet cost (e.g. E/10 MJ). As a result, the findings could be reflecting a mathematical relationship(4). This study investigated how estimated diet costs of NDNS adults relate to dietary energy density using the ‘residuals’ regressionmethod to account for energy. Diet diary information from 2008–2010 was matched to an in-house database of national average (2004) food prices (the DANTE cost database) to assign a cost to each food and non-alcoholic beverage consumed. Mean daily diet costs and costs per 10 MJ were calculated for each participant. Energy density (g/kJ) was derived from foods and milk. The sample median diet cost was £2.84 per day (IQR £2.27, £3.64), or £4.05 per 10MJ (£3.45, £4.82). Values for energy density, food energy, and diet costs by quintiles of dietary energy density (1 = least energy dense) are presented in the table. Adjusted linear regression found a strong negative relationship: additional standard deviation above the diet cost expected for a given energy intake (the residual), there was an associated decrease in energy density of 0.46kJ/g (95% CI - 0.53, - 0.38, p<0.001). This is the first time individual-level diet costs have been characterized for a representative British population. These diet costs represent the inherent value of the diet, and are not comparable to UK expenditure data. The analyses confirm a diet cost-energy density link that is not due to mathematical artefact, and suggest that those consuming more energy-dense diets are achieving more kilojoules for their money

Direct Determination of the Kinetics of Oxygen Diffusion to the Photocytes of a Bioluminescent Elaterid Larva, Measurement of Gas- and Aqueous-Phase Diffusional Barriers and Modelling of Oxygen Supply

We describe the development and use of a direct kinetic technique to determine the time taken for oxygen to diffuse from the external environment into the light-producing cells (photocytes) in the prothorax of bioluminescent larvae of Pyrearinus termitilluminans. This was achieved by measuring the time course of the pseudoflash induced through sequential anoxia followed by normoxia. We have also determined the separate times taken for this oxygen diffusion in gaseous and tissue (predominantly aqueous) phases by using helium and nitrogen as the carrier gas. Of the total time taken for diffusion, that in the gas phase required 613+/-136 ms (mean +/- s.e. m., N=5) whilst that in the aqueous phase required 1313+/-187 ms. These values imply pathlengths of diffusion in the gaseous and aqueous phases of 4.80x10(-)(3)+/-0.53x10(-)(3) and 8. 89x10(-)(5)+/-0.61x10(-)(5 )m, respectively. In addition, the pathlength of gas-phase diffusion was used to derive a parameter relating to the tortuosity of the tracheal system. These values, together with those obtained upon bioluminescent oxygen consumption, have been used to model oxygen supply to the photocyte. From these studies, it would also appear that the modulation of tracheolar fluid levels might be a significant mechanism of control of tissue oxygen levels in at least some insects

Short-term fate of rehabilitated orphan black bears released in New Hampshire

We evaluated the release of rehabilitated, orphan black bears (Ursus americanus) in northern New Hampshire. Eleven bears (9 males, 2 females; 40–45 kg) were outfitted with GPS radio-collars and released during May and June of 2011 and 2012. Bears released in 2011 had higher apparent survival and were not observed or reported in any nuisance behavior, whereas no bears released in 2012 survived, and all were involved in minor nuisance behavior. Analysis of GPS locations indicated that bears in 2011 had access to and used abundant natural forages or habitat. Conversely, abundance of soft and hard mast was lower in 2012, suggesting that nuisance behavior, and consequently survival, was inversely related to availability of natural forage. Dispersal from the release site ranged from 3.4–73 km across both years, and no bear returned to the rehabilitation facility (117 km distance). Rehabilitation appears to be a valid method for addressing certain orphan bear issues in New Hampshire

Scalable, biofunctional, ultra-stable nano- bio- composite materials containing living cells

Three-dimensional encapsulation of cells within nanostructured silica gels or matrices enables applications as diverse as biosensors, microbial fuel cells, artificial organs, and vaccines. It also allows study of individual cell behaviors. Recent progress has improved the performance and flexibility of cellular encapsulation, yet there remains a need for robust scalable processes for large format production of cell-encapsulating materials. Here, we detail two novel techniques, that enable the large-scale production of functional Nano-Bio-Composites (NBCs) containing living cells within ordered 3-D lipid/silica nanostructures: 1) thick-casting and 2) spray drying. Furthermore, we detail a third technique for material scaling in which aqueous, silicate-based gel monoliths encapsulate biofunctional yeast or bacteria. Both dry processes are demonstrated to work with multiple cell types and result in dry powders exhibiting a unique combination of properties including: highly ordered 3-D nanostructure, extended lipid fluidity, tunable macro-morphologies and aerodynamic diameters, and unexpectedly high physical strength. Nanoindentation of the encasing nanostructure revealed Young’s modulus and hardness of 13 and 1.4 GPa respectively, which was unexpected considering the low processing conditions. We hypothesized and confirmed that NBC-encapsulated cells would remain viable for extended periods of time under elevated aging conditions. We attribute this due to the high material strength as observed with nanoindentation, which would prevent cell growth and force bacteria into viable but not culturable (VBNC) states. In concordance with the VBNC state, cellular ATP levels remained elevated even over eight months confirming temperature stable, viable cells. However, their ability to undergo resuscitation and enter growth phase greatly decreased with time in the VBNC state. A quantitative method of determining resuscitation frequencies was developed and showed that, after 36 weeks in an NBC-induced VBNC state, less than 1 in 10,000 cells underwent resuscitation. We verify the VBNC phenotype in gel-encapsulated cells by studying cellular RNA expression levels. These latent behaviors are further demonstrated with an in-vivo immunological study in which mice, immunized with NBCs containing the vaccine Bacillus Calmette-Guérin, were observed to be immunized against a latent form of Tuberculosis. This finding is, in our understanding, the first demonstration of a latent disease-specific live cell immunotherapy. The NBC platform production of industrially scalable quantities of VBNC cells is of interest for research in bacterial persistence and screening of drugs targeting such cells. NBC’s may also enable long-term preservation of living cells for applications in cell-based sensing and the packaging and delivery of live-cell vaccines. Moreover, our methodology represents a novel process for preparing formulations of latent cells in-silico, which could find application in basic cellular research and for the development of a latent-specific vaccine

The monetary value of diets consumed by British adults: an exploration into sociodemographic differences in individual-level diet costs

OBJECTIVE: To describe the diet costs of adults in the National Diet and Nutrition Study (NDNS) and explore patterns in costs according to sociodemographic indicators. DESIGN: Cross-sectional diet diary information was matched to a database of food prices to assign a cost to each food or non-alcoholic beverage consumed. Daily diet costs were calculated, as well as costs per 10 MJ to improve comparability across differing energy requirements. Costs were compared between categories of sociodemographic variables and health behaviours. Multivariable regression assessed the effects of each variable on diet costs after adjustment. SETTING: The NDNS is a rolling dietary survey, recruiting a representative UK sample each year. The study features data from 2008-2010. SUBJECTS: Adults aged 19 years or over were included. The sample consisted of 1014 participants. RESULTS: The geometric mean daily diet cost was £2·89 (95 % CI £2·81, £2·96). Energy intake and daily diet cost were strongly associated. The mean energy-adjusted cost was £4·09 (95 % CI £4·01, £4·18) per 10 MJ. Energy-adjusted costs differed significantly between many subgroups, including by sex and household income. Multivariable regression found significant effects of sex, qualifications and occupation (costs per 10 MJ only), as well as equivalized household income, BMI and fruit and vegetable consumption on diet costs. CONCLUSIONS: This is the first time that monetary costs have been applied to the diets of NDNS adults. The findings suggest that certain subgroups in the UK - for example those on lower incomes - consume diets of lower monetary value. Observed differences were mostly in the directions anticipated

Crystal packing arrangement, chain conformation, and physicochemical properties of gemfibrozil amine salts

Salt formation is used to optimize pharmaceutical properties for carboxylic acid drugs but selection can often be empirical. An extended series of salts of the anti-hyperlipidaemia carboxylic acid drug gemfibrozil was prepared using related series of amine counterions to gain a molecular insight into the impact of crystal packing arrangements on their physicochemical properties. With only a few exceptions, the salts had similar crystal packing motifs. Although there was no discernible relationship between melting point of the salt form and the aqueous solubility of the salt across the whole dataset, there were trends within structurally-related series of salts relating increasing melting enthalpy with increasing molecular weight of the counter ion