Mechanism of hypercholesterolemia produced by biotin deficiency

The effect of biotin deficiency on the metabolism of cholesterol was studied in rats fed cholesterol-free and cholesterol-containing diet. Biotin deficiency induced by feeding raw egg-white resulted in higher cholesterol in the serum and aorta, and higher high density lipoprotein cholesterol and low density lipoprotein + very low density lipoprotein cholesterol. In the liver, cholesterol increased only in the cholesterol diet group but not in the cholesterol-free diet group. Levels of triglycerides were lower in the biotindeficient, cholesterol-free diet group, but triglycerides were elevated in the cholesterol diet group. Concentration of bile acids in the liver and activity of lipoprotein lipase in the heart and adipose tissue were significantly decreased in the biotin-deficient rats. Release of lipoproteins into the circulation, incorporation of [1,2-¹⁴C] acetate into cholesterol, and activity of plasma lecithin: cholesterol acyl transferase were higher.     

Comparison of artificial light photobioreactors and other production systems using Porphyridium cruentum

A new type of preparative photobioreactor for high quality production of microalgae is developed for hatchery-nursery of marine animals, as well as for fine chemicals extraction. Of modular conception, two artificial light photobioreactors in plastic and stainless steel are designed so as to provide strictly controlled conditions in an attempt to increase quality and diminish cost prices. They are assessed for production of Porphyridum cruentum and compared to conventional transparent tanks and solar photobioreactors. The concentration and productivity obtained are ten-fold higher than with hatchery tanks, which leads to a significant drop in cost price of biomass. Comparison is also made with a 10 m² solar photobioreactor operated in the south of France, for which biomass cost price is half that of 1.5 m² artificial light photobioreactor. Extrapolations erasing size discrepancy show that the cost price of the two technologies are not very different. This revised version was published online in June 2006 with corrections to the Cover Date.     

Real-time monitoring of adherent Vero cell density and apoptosis in bioreactor processes

This study proposes an easy to use in situ device, based on multi-frequency permittivity measurements, to monitor the growth and death of attached Vero cells cultivated on microporous microcarriers, without any cell sampling. Vero cell densities were on-line quantified up to 10⁶ cell mL⁻¹. Some parameters which could potentially impact Vero cell morphological and physiological states were assessed through different culture operating conditions, such as media formulation or medium feed-harvest during cell growth phase. A new method of in situ cell death detection with dielectric spectroscopy was also successfully implemented. Thus, through permittivity frequency scanning, major rises of the apoptotic cell population in bioreactor cultures were detected by monitoring the characteristic frequency of the cell population, f_c, which is one of the culture dielectric parameters. Both cell density quantification and cell apoptosis detection are strategic information in cell-based production processes as they are involved in major events of the process, such as scale-up or choice of the viral infection conditions. This new application of dielectric spectroscopy to adherent cell culture processes makes it a very promising tool for risk-mitigation strategy in industrial processes. Therefore, our results contribute to the development of Process Analytical Technology in cell-based industrial processes.     

Hematological changes in Florida pompano (Trachinotus carolinus) supplemented with β-glucan and Pediococcus acidilactici synbiotic

Florida pompano (Trachinotus carolinus) are a species of growing interest for commercial aquaculture. Effective health monitoring is crucial to the successful growout of the species, and prophylactic and therapeutic use of chemicals and antibiotics has been the traditional strategy for promoting stock health. However, concerns about antimicrobial resistance, chemical residues in seafood products and the environment, and resultant immunosuppression have prompted the industry to identify alternative management strategies, including supplementation with prebiotics, probiotics, and combinations of both (synbiotics). The objectives of this study are to determine and compare hematological, plasma biochemical, and plasma protein electrophoresis data of synbiotic-supplemented (β-glucan and Pediococcus acidilactici) and non-supplemented Florida pompano. Reference intervals for blood analytes are provided for both groups and for subgroups (females, males, large, and small fish) where statistically significant results exist. There are no differences between the hematological and plasma biochemistry analytes between the supplemented and control groups, except for blood urea nitrogen and carbon dioxide, indicating a possible effect of synbiotic supplementation on gill function and osmoregulation. Sex-related and size-related differences are observed within each of the control and supplemented groups; however, biometric measurements do not strongly correlate with blood analytes. These data represent baseline hematological and plasma biochemical data in the Florida pompano and indicate the safety of synbiotic supplementation in this commercially important species. This study serves to further the commercialization of Florida pompano by providing blood analyte reference intervals for health monitoring in the aquaculture setting.