Oxidative stress designates the state of imbalance between reactive oxygen species (ROS) production and antioxidant levels. In a healthy placenta, there is an increase in ROS production, due to formation of new tissues and inherent metabolism, but this is balanced by higher levels of antioxidants. However, this balance is lost in some situations, with a consequent increase in oxidative stress levels. Oxidative stress has been implicated in several placental disorders and pregnancy pathologies. The present review intends to summarize what is known about the relationship between oxidative stress and well-known pregnancy disorders.

Red beetroots are rich in betalain pigments, which are divided into betacyanins (predominating in red beetroots) and betaxanthins. The objective of this work was to study efficiency of aqueous extraction of betacyanins from red beets. The experiment was conducted according to a central composite design, with the following variables: solvent pH (pH, 3.0-5.0), solvent-to-beetroot ratio (S ⁄ B, 1:1-5:1), solvent initial temperature (ST, 30-70°C) and grinding time (GT, 2-10 min). Beetroots were ground with the solvent, filtered and evaluated for betacyanin contents. A highly significant model was obtained for betacyanin extraction efficiency (BEE), which was positively affected by ST and S ⁄ B, and inversely affected by pH. The most adequate extraction conditions were pH, 3.0; S ⁄ B, 5:1; ST, 70°C and GT, 2 min. At such conditions, BEE was near 70%. The method is simple and produces a bright red-purple extract to be later dried or concentrated for use as a food colourant.

The degradation of oleic acid in anaerobic filters was studied and the effect of an acclimated inoculum and biomass recirculation was evaluated. Three anaerobic filters (R1, R2, and R3) were operated in parallel. The anaerobic filters R1 and R2 were inoculated with nonacclimated biomass, whereas the anaerobic filter R3 was inoculated with acclimated biomass. In the anaerobic filters R2 and R3, biomass settling and recirculation were applied. The use of an acclimated inoculum and biomass recirculation (R3) was beneficial in terms of removal efficiency, which was 4 to 8% higher than in the anaerobic filters R1 and R2 when oleate was the sole carbon source fed to the reactors at an applied organic load of 12.5 kg of chemical oxygen demand (COD)/m 3 ⅐d, even with an oleate to calcium and magnesium ion molar concentration ratio of 6.8. Biomass recirculation significantly reduced the biomass washout and the toxic effect on the acetogenic and methanogenic populations. The use of an acclimated inoculum was beneficial in terms of methane yield, which was 50% greater than that observed for the reactors inoculated with nonacclimated inoculum for the highest applied organic loading rate (12.5 kg COD/m 3 ⅐d). At the end of the operation, the biomass was encapsulated by a whitish matter, which was well detected by microscopic examination. When this sludge was incubated in batch vials at 37°C where no substrate was added, methane production from the adsorbed organic matter was evidenced, attaining a maximum value (at standard temperature and pressure) of 39.7 mL/g volatile solids⅐d for the biomass taken from R1. With stirring (150 r/min), the methane production rate was 13.8 times higher than under static conditions. When oleate was added to this sludge, methane production was delayed, suggesting that adsorbed matter can be an intermediate of oleate degradation such as stearic, palmitic, myristic, or other saturated acids. Water Environ. Res., 73, 612 (2001).

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: This work describes a comparative study of staged and non-staged anaerobic Ðlters for treating a synthetic dairy waste under similar operating conditions. The e †ect of increasing the substrate concentration from 3 to 12 g COD dm~3 at a constant hydraulic residence time (HRT) of 2 days was evaluated with respect to overall reactor performance, biogas production, volatile fatty acids proÐles along the height, methanogenic and acidogenic activity distribution, and hydrodynamic behaviour. The potential maximum speciÐc methanogenic activity against acetate, hydrogen, propionate and butyrate and the lactose speciÐc activity were determined for sludge sampled from three di †erent points in each reactor, under two operating conditions (inÑuent COD of 3 and 9 g COD dm~3). Although all trophic groups involved in the anaerobic process were found throughout the reactors, it was possible to identify di †erent speciÐc sludges at di †erent heights in both reactors. Performances of the two conÐgu-rations were very similar under the operating conditions tested and the plug Ñow behaviour of the staged reactor was clearly reduced when the inÑuent concentration increased from 3 to 9 g COD dm~3.1998 Society of Chemical Industry ( J. Chem. T echnol. Biotechnol. 73, 99È108 (1998)

Apoptosis is a major problem in animal cell culture during production of biopharmaceuticals, such as recombinant proteins or viral particles. In the present work baculovirus-insect cell expression system (BEVS/IC) is used as model to produce rotavirus like-particles, composed by three layers of three different viral proteins (VP2, VP6 and VP7). In this model baculovirus infection also induces host cell death. Herein a new strategy to enhance cell life span and to increase recombinant rotavirus protein production of BEVS/IC system was developed. This strategy relies on hemolymph from Lonomia oblique (total extracts or a semi-purified fraction) medium supplementation. The total extract and a purified fraction from hemolymph of Lonomia obliqua were able to protect Sf-9 cell culture against apoptosis triggered by oxidative stress (using the pro-oxidant agents tert butylhydroperoxide and hydrogen peroxide) and by baculovirus infection. Furthermore, hemolymph enhance final recombinant protein production, as it was observed by the increased amounts of VP6 and VP7, which were measured by the semi-quantitative western blot method. In conclusion, hemolymph medium supplementation can be a promising strategy to improve cell viability and productivity of recombinant protein in BEVS/IC system.

Ancillary new findings demonstrated that, unlike the situation with a-buffers, Co2+ displaced Ca2+ from the cell-incorporated calcium chelator benz-2, and that benz-2 incorporation had no effect on Co2+-exposed Ca2+ pump desaturation. This validates the use of benz-2 to study Ca2+ pump kinetics in intact cells.

These data suggest that the T allele of the CYBA C242T polymorphism may be used as a marker for adverse metabolic features in Brazilian subjects with systemic hypertension.