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Preterm infants are deficient in long-chain polyunsaturated fatty acids, especially docosahexaenoic acid (DHA), a fatty acid (FA) associated with an increase in bronchopulmonary dysplasia (BPD). In two previous randomized control trials, DHA supplementation did not reduce the risk of BPD. We examined the breast milk FA profile, collected 14 days after birth, of mothers who delivered before 29 weeks of gestation and who were supplemented with DHA-rich algae oil or a placebo within 72 h after birth as part of the MOBYDIck trial. Milk FA were analyzed by gas chromatography. The total amount of FA (mg/mL) was similar in both groups but the supplementation increased DHA (expressed as % of total FA, mean ± SD, treatment vs placebo, 0.95 ± 0.44% vs 0.34 ± 0.20%; P

Unlike large dams which favor methylation of Hg in flooded soils over long periods, run-of-river dams are designed to flood a limited area of soils and are therefore not expected to significantly affect mercury (Hg) cycling or carbon processing. We studied the Hg and carbon cycles within food webs from several sectors along the Saint-Maurice River, Quebec, Canada, that differ in how they are influenced by two run-of-river dams and other watershed disturbances. We observed peak Hg concentrations in fish five-year postimpoundment, but these levels were reduced three years after this peak. Methylmercury concentrations in low trophic level fish and invertebrates were related to their carbon source (δ13C) rather than their trophic positions (δ15N). Biomagnification, measured by trophic magnification slopes, was driven mainly by methylmercury concentrations in low-trophic level organisms and environmental factors related to organic matter degradation and Hg-methylation. River sectors, δ13C and δ15N, predicted up to 80% of the variability in food web methylmercury concentrations. The installation of run-of-river dams and the related pondages, in association with other watershed disturbances, altered carbon processing, promoted Hg-methylation and its accumulation at the base of the food web, and led to a temporary increase in Hg levels in fish.

The preparation of bioactive molecules from biomass substrates is a relevant approach to replace fossil resources. The substitution patterns of natural products facilitate the access to polyfunctio...

Introduction Pregnancy and physical activity are associated with oxidative stress and immune changes. We hypothesized that pregnant women physically more active in early pregnancy will display a better oxidative stress management and inflammatory response later in pregnancy compared with less active pregnant women. Material and methods Maternal physical activity using accelerometry monitors for 1 week and cardiorespiratory fitness (VO2 at anaerobic threshold) were assessed at 14–18 weeks in 58 pregnant women. Plasma and erythrocytes membrane samples were obtained from maternal blood samples at 14–18 and 34–37 weeks of pregnancy. Pro-inflammatory prostaglandin (PG) F2α and oxidative stress-derived F2-isoprostanes were measured by high-performance liquid chromatography coupled to tandem mass spectrometry. Results Higher physical activity levels at 14–18 weeks measured by mean counts per minute, >30 min/d of moderate to vigorous activity or >6500 steps/d at 14–18 weeks of pregnancy were associated with lower levels of total plasmatic PGF2α later in pregnancy. Concentrations of 5 F2-isomers in erythrocyte membranes in late pregnancy were significantly higher in the third (17.5–19.5 mL kg−1 min−1) and/or fourth (19.6–27.7 mL kg−1 min−1) quartiles of cardio-respiratory fitness compared to the first quartile (13.9–15.9 mL kg−1 min−1). Conclusions Overall, higher cardio-respiratory fitness in early pregnancy is associated with enhanced erythrocyte membranes oxidation at 34–37 weeks reflecting a higher oxygen transfer capacity. Also, the most active women experienced lower circulating levels of pro-inflammatory PGF2α in plasma at 34–37 weeks, a marker associated with adverse antenatal inflammation-associated conditions. These results support the practice of physical activity by pregnant women.

Background High-dose vitamin C is increasingly used for sepsis and more recently for coronavirus disease 2019 (COVID-19) infections. Proponents argue that the low cost and near perfect safety profile of vitamin C support its early adoption. Yet, adverse events might be underreported and underappreciated. Case presentation We report a 73-year-old non-diabetic white man with end-stage renal disease on peritoneal dialysis admitted to the intensive care unit with septic shock that was suspected to be due to peritonitis. The patient was enrolled in LOVIT (Lessening Organ Dysfunction with VITamin C; ClinicalTrials.gov identifier: NCT03680274), a randomized placebo-controlled trial of high-dose intravenous vitamin C. He developed factitious hyperglycemia, as measured with a point-of-care glucometer, that persisted for 6 days after discontinuation of the study drug, confirmed to be vitamin C after unblinding. He also had short-lived iatrogenic coma because of hypoglycemia secondary to insulin administration. These events triggered a protocol amendment. Conclusions Although factitious hyperglycemia has been reported before using certain glucometers in patients treated with high-dose vitamin C, the persistence of this phenomenon for 6 days after the discontinuation of the therapy is a distinguishing feature. This case highlights the importance of monitoring glucose with a core laboratory assay for up to a week in specific populations, such as patients on peritoneal dialysis.

Run-of-river power plants (RoRs) are expected to triple in number over the next decades in Canada. These structures are not anticipated to considerably promote the mobilization and transport of mercury (Hg) and its subsequent microbial transformation to methylmercury (MeHg), a neurotoxin able to biomagnify in food webs up to humans. To test whether construction of RoRs had an effect on Hg transport and transformation, we studied Hg and MeHg concentrations, organic matter contents and methylating microbial community abundance and composition in the sediments of a section of the St. Maurice River (Quebec, Canada). This river section has been affected by the construction of two RoR dams and its watershed has been disturbed by a forest fire, logging, and the construction of wetlands. Higher total Hg (THg) and MeHg concentrations were observed in the surface sediments of the flooded sites upstream of the RoRs. These peaks in THg and MeHg were correlated with organic matter proportions in the sediments (r2 = 0.87 and 0.82, respectively). In contrast, the proportion of MeHg, a proxy for methylation potential, was best explained by the carbon to nitrogen ratio suggesting the importance of terrigenous organic matter as labile substrate for Hg methylation in this system. Metagenomic analysis of Hg-methylating communities based on the hgcA functional gene marker indicated an abundance of methanogens, sulfate reducers and fermenters, suggesting that these metabolic guilds may be primary Hg methylators in these surface sediments. We propose that RoR pondages act as traps for sediments, organic matter and Hg, and that this retention can be amplified by other disturbances of the watershed such as forest fire and logging. RoR flooded sites can be conducive to Hg methylation in sediments and may act as gateways for bioaccumulation and biomagnification of MeHg along food webs, particularly in disturbed watersheds.

In aluminium electrolysis cells, the interface between molten metal and electrolyte is animated by surface waves. It is well known that there is a permanent deformation of the bath-metal interface (BMI) due to the magnetohydrodynamic force in the cell. Rafts of agglomerated alumina may float on the BMI. A mathematical model was developed to describe the transport of these rafts by surface waves on the BMI. In this study, we examined the impact of the BMI deformation to the mass transport by waves. The mathematical model is validated by a low temperature physical model. Laboratory experiments with rigid objects driven by regular surface waves were performed for a range of amplitude and frequencies. Two immiscible fluids are used to model the electrolysis cell, the interface between water and silicone oil is animated by regular waves. Theoretical model predictions of the object drift motion are compared with the experimental data.

Alumina dissolution is of first concern in modern electrolysis cells. The rate of dissolution strongly depends on the physical and chemical conditions in the cryolitic melts. In this work, the alumina dissolution rate has been measured with the gravimetric methods in NaF-AlF3-CaF2-Al2O3 systems. To evaluate the influence of the additives and the superheat, a parametric study has been conducted. A wide range of additive content has been studied to meet industrial conditions. Thus, bath compositions with different liquidus temperatures, in the range from 924 to 970 ℃, were used to dissolve alumina at fixed superheat. Results show consistency with physicochemical expectations so that the additive content decreases the alumina dissolution rate and the superheat increases this rate. The experimentally obtained correlations can help to adjust the parameters taking into account their effect on the dissolution.

Reservoirs are known to accelerate the mobilization and cycling of mercury and carbon as aresult of flooding of terrestrial organic matter, which can lead to environmental concerns at local andbroader spatial scales. We explored the covariation of mercury (Hg) and carbon (C) functional pools innatural and recently dammed portions of the aquatic network of the Romaine River watershed in NorthernQuebec, Canada, to understand how the fate of these elements varies across systems with contrastinghydrology and environmental conditions. We found that total Hg (THg) concentrations in surface waterswere relatively constant along the network, whereas both the concentrations and proportions of MeHgtended to increase in reservoirs compared to surrounding nonooded systems, and along the cascade ofreservoirs. Whereas THg was related to total and terrestrial pools of dissolved organic carbon (DOC), MeHgwas weakly related to DOC but strongly linked to surface concentrations of CO2, as well as toconcentrations of iron and manganese. The latter are proxies of cumulative organic matter processing withinthe network, presumably in anoxic portions of shallow bays, deep reservoir waters, and river sediments,as well as in prior seasons (e.g., under ice). Our results suggest that these deep boreal reservoirs acted more astransformation sites for Hg that was already present than as mobilizers of new Hg, and that under icemetabolism plays a role in MeHg production in these systems as we found strong dichotomies in MeHgpatterns between spring and summer.

Objective To examine the associations between risk of pre-eclampsia and pregnancy levels of maternal 25-hydroxyvitamin D (25[OH]D) and oxidative stress biomarkers. Methods A nested case-control study (n = 99; 34 cases; 65 controls) within a prospective pregnancy cohort. Maternal 25(OH)D and oxidative stress markers (six isomers of F2 -isoprostanes; F2 -isoPs) were measured in plasma at 12-18 and 24-26 gestational weeks. Vitamin D deficiency was defined as 25[OH]D less than 50 nmol/L. Results Maternal vitamin D deficiency was associated with increased 8-iso-PGF2α (P = 0.037), 15(R)-PGF2α (P = 0.004), (±)5-iPF2α -VI (P = 0.026) at 12-18 weeks. Vitamin D deficiency was inversely associated with 8-iso-PGF2α (P = 0.019) and (±)5-iPF2α -VI isomer (P = 0.010) at 24-26 weeks. Both maternal vitamin D deficiency (adjusted odds ratio [aOR], 4.79; 95% confidence interval [CI], 1.67-13.75) and increased (±)5-iPF2α -VI (aOR, 2.46; 95% CI, 1.16-5.22) at 24-26 weeks were associated with risk of pre-eclampsia. However, the interaction test between 25(OH)D and (±)5-iPF2α -VI was not significant (P = 0.143). Conclusion Plasma 25(OH)D below 50 nmol/L was associated with increased oxidative stress levels during pregnancy as measured by two F2 -isoP isomers, including the well-studied marker 8-iso-PGF2α . Whether vitamin D-induced oxidative stress mediates the risk of pre-eclampsia warrants future study.

Objective Examine the levels of plasma antioxidant vitamins before and during a treatment with placebo or vitamin E + C supplement to prevent preeclampsia (PE). Study design Per-protocol analysis of a subset group of pregnant women (n = 295) from the International Trial of Antioxidants for the Prevention of PE (INTAPP) randomized case-control study. Normotensive receiving placebo or vitamins (n = 115 and 87 respectively) were compared to gestational hypertension (GH) without proteinuria (n = 30 and 27) and PE (n = 21 and 15). Vitamin quantification was performed at 12–18, 24–26 and 32–34 weeks of gestation. Main outcome measures Coenzyme (Co) Q10, β-carotene and vitamins E (α and γ forms) plasma levels. Results Vitamin E + C supplementation was found to increase the α-tocopherol levels by 40% but was associated with a 57% decrease in the γ-tocopherol isoform for all study groups (p Conclusions A more personalized approach that target the suboptimal levels of specific antioxidants without disturbing the α/γ-tocopherol ratio could be a more successful approach to counteract oxidative stress in PE.

Introduction Cancer has been associated with increased oxidative stress and deregulation of bioactive oxylipins derived from long-chain polyunsaturated fatty acids (LC-PUFA) like arachidonic acid (AA). There is a debate whether ω-3 LC-PUFA could promote or prevent prostate tumor growth through immune modulation and reduction of oxidative stress. Our aim was to study the association between enzymatically or non-enzymatically produced oxidized-LC-PUFA metabolites and tumor growth in an immune-competent eugonadal and castrated C57BL/6 male mice injected with TRAMP-C2 prostate tumor cells, fed with ω-3 or ω-6 LC-PUFA-rich diets. Materials and methods Tumor fatty acids were profiled by gas chromatography and 26 metabolites derived from either AA, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) were assessed by liquid chromatography-mass spectrometry. Results The enriched ω-3 diet did not reduce oxidative stress overall in tumors but favored the formation of ω-3 rather than ω-6 derived isoprostanoids. We discovered that EPA and its oxidized-derivatives like F3-isoprostanes and prostaglandin (PG)F3α, were inversely correlated with tumor volume (spearman correlations and T-test, p Discussion Decreasing tumor growth under ω-3 diet could be attributed in part to increased levels of EPA and its oxidized-derivatives, a reduced level of pro-angiogenic PGE2 and increased levels of F4-neuroprostanes and resolvins content in tumors, suspected of having anti-proliferative and anti-inflammatory effects.

The movement of waves on the surface of a fluid is always accompanied by a displacement of the fluid particles in the wave propagation direction, this is called the Stokes drift. This phenomenon can be found in aluminum electrolysis cells. More or less regular oscillations animate the interface between the electrolyte bath and the metal in a cell. It is well known that material, such as rafts of undissolved alumina and solidified bath and cryolite snow can float on the metal-bath interface. So these objects can be transported by waves on the interface. The purpose of this paper is to review the literature on the works already done about the surface waves, interface waves and Stokes drift. Then the mass transport induced by these waves will be estimated for the case of the metal bath interface in the electrolysis cells.

Background Diabetes and pregnancy are both associated with oxidative stress, characterized by an increase of F2-isoprostanes from the non-enzymatic oxidation of arachidonic acid, a n − 6 polyunsaturated fatty acid (PUFA). We hypothesized that pregnant women with pre-existing diabetes will be characterized by elevated levels of specific F2-isoPs isomers and altered PUFA composition in plasma early pregnancy when compared to normoglycemic controls. Methods Plasma samples from 23 women with uncomplicated pregnancies and 11 women with pre-existing diabetes in pregnancy were collected between 12 and 18 weeks of pregnancy (MIROS cohort). Six F2-isoprostanes isomers were measured by high-performance liquid chromatography coupled to tandem mass spectrometry. Fatty acids concentrations in plasmatic phospholipids were measured by gas chromatography coupled to a flame ionization detector. Results F2-isoprostanes, specifically the 8-iso-15(R)-PGF2α levels, were 67% higher in diabetic than normoglycemic pregnancies (p = 0.026). The total n − 6 PUFA and arachidonic acid level did not differ between study groups. In contrast, total n − 3 level was 32% lower in diabetic pregnancies than in controls (p = 0.002); EPA(20:5) and DHA(22:6) being specifically reduced (p = 0.035 and p = 0.003 respectively). Delta-6-desaturase (D6D) activity index, calculated using fatty acid ratios, was 9% lower in pre-existing diabetes than in controls (p = 0.042). Conclusions Pre-existing diabetes in early pregnancy displays a distinctive F2-isoprostanes profile when compared to other pathologies of pregnancy, such as preeclampsia, as previously assessed in the same cohort.

Molten cryolite mixed with some additives is used as solvent of alumina by aluminium producers. Cryolite represents the dominating compounds in the wall protecting side-ledge and at the bottom part of the frozen crust on the top of the cells. As the heat, generated in the cell, is lost mainly through the top and the lateral sides of the pot, the thermo-physical properties of the cryolite determine thermal equilibrium and its knowledge is crucial for any numerical thermal model of the cell. Unfortunately, there is a serious lack in experimental thermal diffusivity and conductivity data for pure cryolite. The goal of this paper was to determine experimentally the apparent thermal diffusivity of the purest available cryolite in a wide temperature range and compare it with an earlier published theoretical model, based on first principle calculations. Measurement was carried out using monotone heating technique between 200 and 850 °C on low porosity synthetic cryolite, containing 0.9 mass% of alumina. Experiment setup was improved at the level of protection of the thermocouples compared to earlier published article. This permitted to repeat the test more times with the same sample and reach higher temperatures. Results suggest that the thermal diffusivity of α-cryolite increases very slowly from 3 × 10−7 to 3.5 × 10−7 m2 s−1 between 200 and 560 °C where α–β transformation starts to take place. The transformation is completed around 600 °C. The thermal diffusivity of the β-cryolite is somewhat higher and rise significantly faster with temperature compared to the α-crystal. Namely, it increases from 4.1 × 10−7 to 7.3 × 10−7 m2 s−1 between 600 and 850 °C. DSC tests were carried out, to help to evaluate deviations on the monotone heating curves. Experimental results are in good agreement with the earlier published theoretical model.

OBJECTIVES: We hypothesized that the intake of industrially originated trans-fatty acids (elaidic acid (EA trans 18: 1n-9)) and ruminant trans fatty acids (trans-palmitoleic acid (TPA t16:1 n-7)) will differentially modify gut microbiota and short-chain fatty acids (SCFA) profiles. The objective is to compare the long- and short-term effects of EA and TPA on the fecal microbiome and SCFAs profiles in mice. METHODS: Forty C57BL/6 mice were divided to 4 groups. Each group was given one of the following 4 formulations in the drinking water: lecithin nanovesicles, nanovesicles containing either lecithin with EA or TPA (86:14 (w/w)) or water alone (control) for 28 days with a normal fat diet. Fecal samples were collected at days 0, 7 and 28. Gut microbiota profiles were determined by 16S rRNA gene sequencing. SCFAs were measured by headspace gas chromatography coupled to a single quadrupole mass spectrometer. Baseline data (relative abundance of bacteria or levels of SCFAs) was pooled and then compared with data from day 7 or day 28 for each formulation. RESULTS: After 7 days of lecithin, 16S rRNA analysis revealed an increase in the relative abundance of Lactobacillus. After 28 days of lecithin, an increase in the relative abundance of Lactobacillus, Erysipelotrichaceae, and Enterobacteriaceae together with a decrease in Bacteroidaceae was observed. Further, a tendency to increase level of butyric acid (P = 0.053) was observed after 28 days of lecithin. After 7 days of EA, an increase in the relative abundance of Lactobacillus, whereas a decrease in the relative abundance of Parabacteroides, Bacteroides, Rumininococcaceae, Lachnospiraceae and Peptococcaceae was observed. After 7 days of TPA, results show a decreased level of isovaleric acid (P = 0.04) and valeric acid (P = 0.03). After 28 days of TPA, data demonstrates an increase in the level of butyric acid (P = 0.01) and propionic acid (P = 0.01). Water intake for 28 days decreased the level of valeric acid (P = 0.02). CONCLUSIONS: Consumption of industrial and ruminant trans-fatty acids modify differentially bacterial taxa present in the gut microbiome and SCFA profiles. FUNDING SOURCES: NSERC, CMDO.

This study aimed to determine whether dairy macronutrients alter markers of inflammation and oxidative stress in endothelial cells. Human endothelial cells (HUVEC) were treated with ruminant trans fatty acids (rTFA), either trans-vaccenic acid (tVA) or trans-palmitoleic acid (tPA), whey protein hydrolysate, leucine or combinations of rTFA and dairy protein compounds. Industrial TFA elaidic acid (EA) was also investigated and compared with rTFA. Inflammatory prostaglandins (PG) and F2-isoprostanes (F2-isoP) isomers, markers of oxidative stress, were assessed in cell supernatants by LC-MS/MS. Both tVA and tPA, as well as whey protein hydrolysate, decreased TNFα-induced PG excretion. Combinations of rTFA and dairy protein compounds decreased inflammation to a similar extent than rTFA alone. EA increased class VI F2-isoP isomers, whereas tVA mostly raised class III isomers. In summary, rTFA decreased inflammatory markers and increased oxidative stress markers in endothelial cells. Combinations of rTFA with whey proteins or leucine showed no additive effect.

Vasoactive eicosanoids such as thromboxane (TX) A2 and F2-isoprostanes (F2-isoPs) were shown to be increased in the preeclamptic placenta. Only one of the 64 possible isomers of F2-isoPs derived from the oxidation of arachidonic acid was investigated in the placenta so far. F2-isoPs are released from membrane phospholipids by phospholipases A2 (PLA2) and were shown to act on the TXA2 receptor (TBXA2R). However, the PLA2 deregulated in preeclampsia (PE) remains to be determined. In this study, we analyzed the concentrations of six isomers of F2-isoPs; 8-iso-PGF2α, 8-iso-15(R)-PGF2α, 15(R)-PGF2α, iPF2α-IV, iPF2α-VI, 5-iPF2α-VI and the concentrations of the stable metabolites of TXA2, TXB2, by high performance liquid chromatography coupled with tandem mass spectrometry in placentas of PE (n = 17) and normotensive (n = 15) pregnancies according to the biopsy site: peri-insertion or periphery. In the same biopsies, relative mRNA expression of PLA2G2A, PLA2G4A, PLA2G5, PLA2G7, the PLA2 receptor (PLA2R1), the TXA2 synthase and TBXAR2 were measured by quantitative RT-PCR. We observed similar concentrations of total F2-isoP isomers between groups whereas higher concentrations (>40%) of free F2-isoP were observed for all isomers (p ≤ 0.033) in PE than normotensive controls. As expected, we also observed higher placental concentrations of TXB2 in PE (p = 0.005). Interestingly, we concomitantly found higher mRNA expression of secretory PLA2G2A (p = 0.010), PLA2G5 (p = 0.038) and TBXA2R (p = 0.023) in PE than normotensive placentas. In sum, deregulated PLA2 could potentially be implicated in freeing F2-isoP which could participate in local hypertension observed in the PE placenta through the TX pathway.

In aluminum electrolysis cells, a ledge of frozen electrolyte is formed on the sides. Controlling the side ledge thickness (a few centimeters) is essential to maintain a reasonable life span of the electrolysis cell, as the ledge acts as a protective layer against chemical attacks from the electrolyte bath used to dissolve alumina. The numerical modeling of the side ledge thickness, by using, for example, finite element analysis, requires some input data on the thermal transport properties of the side ledge. Unfortunately, there is a severe lack of experimental data, in particular, for the main constituent of the side ledge, the cryolite (Na3AlF6). The aim of this study is twofold. First, the thermal transport properties of cryolite, not available in the literature, were measured experimentally. Second, the experimental data were compared with previous theoretical predictions based on first principle calculations. This was carried out to evaluate the capability of first principle methods in predicting the thermal transport properties of complex insulating materials. The thermal diffusivity of a porous synthetic cryolite sample containing 0.9 wt % of alumina was measured over a wide range of temperature (473–810 K), using the monotone heating method. Because of limited computational resources, the first principle method can be used only to determine the thermal properties of single crystals. The dependence of thermal diffusivity of the Na3AlF6 + 0.9 wt % Al2O3 mixture on the microstructural parameters is discussed. A simple analytical function describing both thermal diffusivity and thermal conductivity of cryolite as a function of temperature is proposed.

Trans fatty acids (TFA) intake has been linked to cardiovascular diseases and liver diseases; yet the effect of TFA on inflammation remains controversial. Accordingly, the objective of this paper was to determine the in vitro effects of TFA on inflammatory gene expression. Human umbilical vein endothelial cells (HUVEC) and human hepatocellular carcinoma (HepG2) cells were treated for 24 h with either trans-vaccenic acid (tVA), trans-palmitoleic acid (tPA) or elaidic acid (EA) at concentrations of 5-150 µM, or with a mixture of tVA and tPA (150/50 µM). All TFA were highly incorporated into cell membranes, as determined by gas chromatography, representing 15-20% of total fatty acids in HUVEC and 3-8% in HepG2 cells. Incorporation of EA, a common industrial TFA, increased the ratio of the stearoyl-CoA desaturase (SCD-1), a key enzyme involved in fatty acid metabolism. Ruminant TFA, including tVA, tPA and the mixture of tVA and tPA, significantly reduced the TNF-α-induced gene expression of TNF, VCAM-1 and SOD2 in HUVEC, as well as TNF and IL-8 in HepG2 cells. EA also decreased inflammatory gene expression in HUVEC, but not in HepG2 cells. The inhibition of peroxisome proliferator-activated receptor (PPAR)-γ did not influence the effects of TFA on gene expression. Overall, physiological and supraphysiological concentrations of TFA, especially tVA and tPA, prevented inflammatory gene expression in vitro. This effect is independent of PPAR-γ activation and may be due to an alteration of fatty acid metabolism in cell membranes caused by the high incorporation of TFA.

The cathodic carbon to cast iron electrical contact degradation is one of the factors to consider in the cathode voltage drop (CVD) increase over the lifetime of aluminum production cells. Lab-scale experiments were carried out to study the cast iron to carbon interface chemical degradation and the impact of important cell parameters like temperature and bath chemistry. Laboratory degradation results were compared with industrial samples. A thermoelectric Ansys numerical model was then used to predict the effect of cast iron surface degradation over CVD. Results show that the aluminum formation on the cast iron surface and its subsequent diffusion creates an immiscible mixture of Fe-Al metal alloy and electrolytic bath. Disparities were also observed between industrial samples taken from two different technologies, suggesting that the degradation can be slowed down. Thermoelectric calculations finally revealed that the impact of the contact resistance augmentation is by far greater than the cast iron degradation.

International audience; Central to drug discovery is the correct characterization of the primary structures of compounds. In general, medicinal chemists make great synthetic and characterization efforts to deliver the intended compounds. However, there are occasions which incorrect compounds are presented, such as those reported for Bosutinib and TIC10. This may be due to a variety of reasons such as uncontrolled reaction schemes, reliance on limited characterization techniques (LC-MS and/or 1D 1H NMR spectra), or even the lack of availability or knowledge of characterization strategies. Here, we present practical NMR approaches that support medicinal chemist workflows for addressing compound characterization issues and allow for reliable primary structure determinations. These strategies serve to differentiate between regioisomers and geometric isomers, distinguish between N- versus O-alkyl analogues, and identify rotamers and atropisomers. Overall, awareness and application of these available NMR methods (e.g. HMBC/HSQC, ROESY and VT experiments, to name only a few) should help practicing chemists to reveal chemical phenomena and avoid mis-assignment of the primary structures of compounds.

Evidence supports that a high dietary fat intake increases oxidative stress and the risk of diet-induced metabolic disorders such as obesity, diabetes and cardiovascular diseases. F2-isoprostanes (F2-isoP) are formed by the non-enzymatic oxidation of arachidonic acid and are widely used as reliable biomarkers of oxidative stress in clinical studies. Dietary fats may influence F2-isoP levels, as they (1) are metabolic substrates for their formation, (2) modify the lipid composition of tissues, and (3) affect the plasma lipoprotein concentrations which are involved in F2-isoP transport. This review examined the latest clinical evidence on how dietary fats can affect blood circulation and excretion of F2-isoP in individuals with healthy or deteriorated metabolic profiles. Clinical studies reported that saturated or monounsaturated fat-rich diets did not affect F2-isoP levels in adults with healthy or deteriorated metabolic profiles. Though, ω-3 polyunsaturated fatty acids decreased F2-isoP levels in numerous studies, whereas trans-fatty acids raised F2-isoP excretion. Yet, the reported heterogeneous results reveal important considerations, such as the health status of the participants, the biological fluids used to determine F2-isoP, the analytical methods employed and the specific F2-isoP isomers detected. Therefore, future clinical studies should be designed in order to consider these issues in the studies of the effects of fat intake on oxidative stress.

At the La Grande hydroelectric complex (Quebec, Canada), total mercury concentrations were measured in more than 25 000 fish over a 20-year period. Fish population characteristics, such as fishing yield, growth rate, condition factor, and recruitment, were also monitored. In reservoirs, total mercury concentrations in all species increased rapidly after impoundment, peaking after 4 to 9 years in nonpiscivorous fish and after 9 to 11 years in piscivorous species, at levels three to seven times those measured in surrounding natural lakes, then declined gradually and significantly. Despite this increase, most species showed increases in fishing yields (by factors ranging from 2 to 8), growth rates, and condition factors (for more than a decade). The percentage of small specimens of the main species was generally maintained or increased in the first years after flooding, indicating good recruitment.

Optimization of pyridine-based noncatalytic site integrase inhibitors (NCINIs) based on compound 2 has led to the discovery of molecules capable of inhibiting virus harboring N124 variants of HIV integrase (IN) while maintaining minimal contribution of enterohepatic recirculation to clearance in rat. Structure-activity relationships at the C6 position established chemical space where the extent of enterohepatic recirculation in the rat is minimized. Desymmetrization of the C4 substituent allowed for potency optimization against virus having the N124 variant of integrase. Combination of these lessons led to the discovery of compound 20, having balanced serum-shifted antiviral potency and minimized excretion in to the biliary tract in rat, potentially representing a clinically viable starting point for a new treatment option for individuals infected with HIV.

We hypothesized that the mild physiological oxidative stress present during pregnancy could increase both, plasma F 2 -isoprostanes (F 2 -isoPs) by lipid oxidation and trans fatty acids (TFA) through cis-trans isomerization respectively. Plasma samples collected at 12–18 weeks (MIROS cohort; n =65) and 38–41 weeks of pregnancy (CHUL cohort; n =21) were subjected to alkaline hydrolysis followed by liquid–liquid extraction in order to extract total F 2 -isoPs for quantification by HPLC–MS/MS. Several positive correlations were found between F 2 -isoPs and TFA, measured by GC-FID in plasma phospholipids, such as 6 t -18:1, 9 t -18:1 and 9 t ,12 c -18:2 ( r >0.306; p t ,12 c -18:2 trans isomer, known to be associated to cardiovascular diseases, showed the most significant correlations with F 2 -isoPs. No correlation was observed between F 2 -isoPs and 9 t -16:1 or 11 t -18:1. In summary, this study suggests either a concomitant phenomenon or a competition between lipid peroxidation and cis - trans isomerisation of the cis precursor fatty acid in vivo during pregnancy.

Solidification of cryolite (Na3AlF6)-based bath takes place at different rates along the sideledge, and around alumina rafts and new anodes. The solidification rate has a significant impact on the structure and the chemical composition that determine the thermal conductivity and thus the thickness of sideledge, or the duration of the existence of the temporary frozen bath layers in other cases. Unfortunately, samples that can be collected in industrial cells are formed under unknown, spatially and temporally varying conditions. For this reason, frozen bath samples were created under different heat flux conditions in a well-controlled laboratory environment using the so-called cold finger technique. The samples were analyzed by X-ray Diffractometer (XRD) and Scanning Electron Microscope (SEM) in Back Scattering (BS) mode in order to obtain spatial distribution of chemical composition. Results were correlated with structural analysis. XRD confirmed our earlier hypothesis of recrystallization of cryolite to chiolite under medium heat flux regime. Lower α-alumina, and higher γ-alumina content in the samples obtained with very high heating rate suggest that fast cooling reduces α–γ conversion. In accordance with the expectation, SEM-BS revealed significant variation of the Na/Al ratio in the transient sample.

There is a constant effort from aluminium producers to reduce energy consumption of the Hall-Heroult cells in order to decrease cost and environmental fingerprint. Among others, slotted anodes were introduced in order to promote faster evacuation of the electrically isolating anode gas bubbles and thus diminish their contribution to the total cell voltage. A bubble layer simulator was developed to reproduce cell voltage fluctuations, caused by the dynamics of anode bubbles. Results of simulations show that the slots cut in the right position and direction can reduce both the amplitude of fluctuations and the average cell voltage. This impact is even higher for new, almost horizontal flat anode bottoms. It is also revealed that the slots are acting mainly as a simple bubble sink, but they also contribute to the acceleration of the bubble layer as well and thus their role in the momentum exchange between liquid and gas must be taken into account.

Carbon-cast iron electrical contact degradation is still considered as one of the main cause for the CVD increase over the lifetime of the electrolysis cell. A thermoelectric finite element model was developed to evaluate the effect of the carbon-cast iron electrical contact degradation and the cathode erosion on the CVD and the current distribution inside the cathodic assembly. Chemical degradation data from laboratory and industrial samples were used to calibrate the cast iron and the contact resistivities. Results demonstrate that the carbon block erosion and the contact degradation at the cast iron interface have a direct impact on the current distribution at the carbon block surface. Both factors increase the CVD when taken separately but the contact degradation outperforms the carbon block wear when taken together.

It is a well-known phenomenon in aluminum industry that alumina powder, fed into the electrolyte, tends to stay afloat on the surface of the bath. This hinders dispersion and direct contact of most of the powder with the electrolyte, therefore delays dissolution. In addition, large clusters of alumina particles sintered together during raft formation might lead to the agglomerate piercing through the bath-aluminum interface, which should be avoided. Since the interference between raft formation and alumina dissolution is significant, it deserves more attention. Several experiments were conducted in a small carbon crucible in which cryolitic bath was melted and alumina of different properties was fed. The injections were recorded by a video camera above the bath. The spreading of the powder on the surface, the infiltration of powder by the bath as well as the disintegration or the sinking of the raft was observed and the results analyzed.

A scaffold replacement approach was used to identifying the pyridine series of noncatalytic site integrase inhibitors. These molecules bind with higher affinity to a tetrameric form compared to a dimeric form of integrase. Optimization of the C6 and C4 positions revealed that viruses harboring T124 or A124 amino acid substitutions are highly susceptible to these inhibitors, but viruses having the N124 amino acid substitution are about 100-fold less susceptible. Compound 20 had EC50 values10 nM against viruses having T124 or A124 substitutions in IN and800 nM in viruses having N124 substitions. Compound 20 had an excellent in vitro ADME profile and demonstrated reduced contribution of biliary excretion to in vivo clearance compared to BI 224436, the lead compound from the quinoline series of NCINIs.

An assay recapitulating the 3' processing activity of HIV-1 integrase (IN) was used to screen the Boehringer Ingelheim compound collection. Hit-to-lead and lead optimization beginning with compound 1 established the importance of the C3 and C4 substituent to antiviral potency against viruses with different aa124/aa125 variants of IN. The importance of the C7 position on the serum shifted potency was established. Introduction of a quinoline substituent at the C4 position provided a balance of potency and metabolic stability. Combination of these findings ultimately led to the discovery of compound 26 (BI 224436), the first NCINI to advance into a phase Ia clinical trial.

SCOPE Metabolomics is increasingly used to identify biomarkers of diet or chronic diseases, such as type 2 diabetes. Yet, metabolite signatures following dairy intake in hyperinsulinemic subjects have not been identified. The objective is to evaluate the effects of a high dairy diet (HD) for 6 weeks (4 servings or more per day), compared with an adequate dairy diet (AD) (2 servings or less per day), on serum metabolite profiles in hyperinsulinemic adults. METHODS AND RESULTS In this crossover trial, subjects are randomized to HD or AD for 6 weeks. Serum metabolites are assessed using GC/MS. Twenty-six subjects completed the study. Levels of pentadecanoic acid, tyrosine and lathosterol are increased in HD, while 1,5-anhydrosorbitol, myo-inositol, 3-aminoisobutyric acid and beta-sitosterol are decreased (p < 0.05). Sorbitol levels are increased after AD, while hexanoic acid, lauric acid, l-kynurenine, methionine, and benzoic acid levels are reduced (p < 0.05). Histidine, caprylic acid, nonanoic acid, decanoic acid, lauric acid, heptadecanoic acid, and benzoic acid levels are increased in HD compared to AD, while malic acid levels are increased in AD compared with HD (p < 0.05). CONCLUSION Higher dairy products intake modifies metabolite profiles in hyperinsulinemic subjects.

The solidification of the electrolytic bath in Hall-Heroult cells includes the formation of a sideledge, crust as well as temporary freeze layers around alumina agglomerates, new anodes or any cold object inserted into the bath. The structure and the chemical composition of solidified phases depend on the cooling heat flux (or cooling rate), which has a huge impact on the formation of crystals, amorphous phases and pores and on the extent of ion migration. The structure and chemical composition determine the heat loss through the side ledge, and the duration of the existence of a frozen bath around alumina agglomerates or new anodes. The authors of this paper created frozen bath samples under different heat flux conditions in well controlled laboratory environment in order to study the variation of the chemical composition and structure with the cooling rate. The results of this study are presented in this article.

Potential consequences of radiological/nuclear events on the population and the environment have led the scientific community to rethink its approach toward a monitoring based on radiochemical separation. In this context, there is a great need to design radioanalytical systems for quickly evaluating environmental impacts in case of incidents and nuclear events. Phosphonate-functionalized large pore three-dimensional (3-D) cubic (KIT-6) and two-dimensional (2-D) hexagonal (SBA-15) silicas have been studied as highly efficient uranium extracting adsorbents in acidic media. In both cases, functionalization was performed by grafting (2-diethylphosphatoethyl) triethoxysilane (DPTS) on the mesopore surface of the silica supports. Particular attention was given to comparison of different pore sizes and pore structures and impact on radionuclide extraction, principally through uranium adsorption isotherms and sorption kinetics studies. All hybrid materials demonstrated very fast adsorption kinetics, reaching equi...

Reports indicate that antioxidant enzymes like the glutathione peroxidases (GPx) can be regulated by sex steroids. The GPx, a major class of antioxidants involved in H(2)O(2) and lipid hydroperoxides neutralization, showed an age- and sex-specific expression in many adult organs including the lung. High levels of androgens in the male lung are known to delay the surge of surfactant synthesis during gestation in several species. However, the impact of male androgens on antioxidant GPx early in life remains to be determined. The objective was to study the lung sex-specific expression of GPx during BALB/c mouse perinatal development. The mRNA expression of four seleno-dependent Gpx (Gpx1 to 4) in the lung of both sexes was characterized by real-time PCR from gestational day 15 to postnatal day 30, covering the entire canalicular, saccular and alveolar stages. Immunohistochemistry of GPx-1, -3 and -4, and seleno-dependent GPx enzymatic assays were also performed in the lung. We found a transient lower Gpx1 mRNA level in male than in female lungs during the first 5 days after birth, corresponding to the saccular phase. This dimorphic expression was concomitant to a sex difference in GPx enzymatic activity corrected for blood. It is, to our knowledge, the first report of a sex dimorphism for murine lung enzymatic antioxidant defenses during the perinatal period.

This project aimed to determine the effect of Se as inorganic Na-selenite (MSe) or organic Se-yeast (OSe) on antioxidant status, hormonal profile, reproductive performance, and embryo development in first-parity gilts. Forty-nine gilts were allocated to 1 of the 3 dietary treatments starting at first pubertal estrus and lasting up to 30 d after AI: control [CONT: basal diet (Se = 0.2 mg/kg) without added Se; n = 16], MSe (CONT + 0.3 mg/kg of MSe; n = 16), and OSe (CONT + 0.3 mg/kg of OSe; n = 17). Blood was collected from all gilts on the day after each onset of estrus and on d 30 after AI. Blood was also collected daily from d -4 to d +4 of the third onset of estrus (d 0) in 8 CONT, 9 MSe, and 8 OSe cannulated gilts. Gilts had received, after d 14 and 15 of their third estrus, a hormonal challenge to induce super-ovulation. At slaughter, embryos and corpora lutea (CL) were weighed and measured. Blood Se was less (P < 0.01) in CONT than in Se gilts and greater in OSe than in MSe (P < 0.01) from the first estrus until d 30 of gestation. At the same time, blood Se-dependent glutathione peroxidase (GSH-Px) decreased for CONT gilts, whereas it increased for both Se groups. The increase was greater in MSe than in OSe gilts (treatment × time, P = 0.02). Plasma 3,3',5-triiodothyronine and thyroxine concentrations for MSe tended to be less than for OSe gilts (P < 0.06). In cannulated gilts, plasma FSH tended to change among treatments (treatment × time, P = 0.06), and plasma estradiol-17β (E(2)) was less (P = 0.01) for MSe than for OSe. There was no treatment effect on mean litter size or embryonic antioxidant status. The Se content of individual embryos was greater for Se-treated than for CONT gilts (P = 0.03), and Se content of individual embryos and total litter was greater for OSe than for MSe gilts (P < 0.01). The length, weight, and protein content of embryos were greater in OSe than in MSe gilts (P < 0.05). There was no treatment effect on weight, length, Se content, and ferric reducing antioxidant power of CL, but GSH-Px in CL was greater for Se than for CONT gilts (P = 0.02). In summary, the Se status response of gilts to dietary Se was affected by both the quantity and the source of Se dietary supplements. Moreover, the uterine transfer of Se to embryos was improved with OSe as compared with MSe, and this was concomitant with an enhanced development of embryos.

In vitro cell model studies have shown that oxidative stress may affect beta-cell function. It is unknown whether oxidative stress may affect metabolic health in human fetuses/newborns. In a singleton pregnancy cohort (n = 248), we studied maternal (24–28 weeks gestation) and cord plasma biomarkers of oxidative stress [malondialdehyde (MDA), F2-isoprostanes] in relation to fetal metabolic health biomarkers including cord plasma glucose-to-insulin ratio (an indicator of insulin sensitivity), proinsulin-to-insulin ratio (an indicator of beta-cell function), insulin, IGF-I, IGF-II, leptin, adiponectin and ghrelin concentrations. Strong positive correlations were observed between maternal and cord plasma biomarkers of oxidative stress (r = 0.33 for MDA, r = 0.74 for total F2-isoprostanes, all p

The use of β,γ-unsaturated-α-ketoesters in the intermolecular Stetter reaction furnishes 1,2,5-tricarbonyl compounds in high yield and excellent enantioselectivity. The α,δ-diketoesters generated using this methodology serve as useful synthetic building blocks via chemo- and diastereoselective transformations.

Increased placental oxidative stress in preeclampsia (PE) has been associated in part to a decrease in glutathione peroxidase (GPX) antioxidant activity. However, it is not clear if GPX mRNA expression is affected in PE, and how the presence of labor may impair this expression. In this study, we characterized by quantitative PCR, in situ hybridization and immunohistochemistry, the expression of four GPX (GPX1 to 4) in the placenta of normotensive (NP; n = 23) and PE pregnancies (n = 25) according to mode of delivery: vaginal delivery (with labor) or cesarean (without labor); the tissue layer: amnion-chorion (AC) and villi; and the sampling site: peri-insertion or peripheral. Concomitantly, oxidative stress markers mRNA expression, HSP70 and HO-1 were measured. All GPX mRNA and protein were detected in all layers of the placenta and sampling sites. In absence of labor, GPX1 is more expressed near the umbilical cord than at the periphery of the villi (p = 0.037). At the periphery of AC membranes, GPX2 was more expressed in PE than in controls in presence of labor (p = 0.037). Interestingly, GPX4 mRNA level was clearly deficient in the PE villi in presence or absence of labor (p < 0.0473). Also, the GPX4 expression in PE was lower than controls in AC membranes in presence of labor (p = 0.0007). Oxidative stress markers, HSP70 and HO-1, were higher in PE placental membranes than in controls in absence of labor (p < 0.011). HSP70 was also upregulated in PE placental membranes in presence of labor (p = 0.034). Correlations between stress markers and GPX mRNA expression were mostly present in AC membranes in presence of labor in NP. Most of the latter correlations were lost in PE. In conclusion, our results suggest that the reported decrease in GPx activity and increased oxidative stress in PE placental villi may be attributed in part to GPX4 independently of the presence or absence of labor.

A full overview of the decarboxylative cross-coupling reaction between heteroaromatic carboxylic acids and aryl halides is described. This transformation employs palladium catalysts with short reaction times providing facile synthesis of aryl-substituted heteroaromatics. The effect of each reaction parameter including solvent, base, and additive employed as well as the full substrate scope of this transformation are reported. Mechanistic evidence is also disclosed that sheds light on possible reaction pathways.

A new method for solid phase parallel synthesis of chemically and conformationally diverse macrocyclic peptidomimetics is reported. A key feature of the method is access to broad chemical and conformational diversity. Synthesis and mechanistic studies on the macrocyclization step are reported.

Assisted reproduction using frozen-thawed semen has practical advantages, although cryopreservation is detrimental to sperm fertility in most mammals. We examined the influence of cryopreservation and reactive oxygen species (ROS) on ram sperm DNA stability (using SCSA), lipid peroxidation (LPO), chlortetracycline fluorescence (CTC) patterns, motility and viability. In Experiment 1, DNA integrity, LPO, CTC, motility and viability tests were performed on fresh and cryopreserved sperm after 0, 6, and 24 hr in synthetic oviductal fluid (SOF). In Experiment 2, fresh sperm were incubated in serum-free SOF (SOF-S; 1, 4, and 24 hr) with 0, 50, 150, or 300 microM H2O2 then assayed. Cryopreservation increased the percentage of sperm with a high DNA fragmentation index (%DFI), decreased the percentages of motile and viable sperm at thawing (0 hr), but did not affect LPO. H2O2 (150 or 300 microM) increased %DFI after 24 hr. LPO or sperm viability were not affected by H2O2, although most motility parameters decreased. H2O2 decreased the percentage of chlortetracycline pattern F sperm at 4 hr and increased the percentage of acrosome-reacted sperm (pattern AR) after 1 hr. Pooled data of Experiment 2 showed LPO was positively correlated with SCSA (r = 0.29 to r = 0.59; P < 0.05 to P < 0.01), while most motility parameters and the percentage of viable sperm were negatively correlated with LPO (r = -0.30 to r = -0.38; P < 0.05 to P < 0.01). LPO was positively correlated with the percentage of pattern AR sperm (r = 0.33; P < 0.01). Cryopreservation and H2O2 promote DNA instability in ram sperm, though motility is a more sensitive indicator of oxidative stress than the other parameters investigated.

Preeclampsia (PE) has long been associated with early oxidative stress, although the symptoms occur later in pregnancy. We have hypothesized that the oxidative stress in PE, as characterized by the presence of F2-isoprostane (F2-isoP) isomers in late pregnancy, should already be present in plasma at the first regular visit of the obstetrical follow-up. There are 64 possible isomers of F2-isoPs derived from the oxidation of arachidonic acid (AA), but only one of these isomers has been investigated so far in PE, the classical 8-iso-PGF2α. Here, we have investigated two regioisomers of class III (8-iso-15(R)-PGF2α and 8-iso-PGF2α) and a mix of two isomers of class VI ((±)5-iPF2α-VI) in plasma samples collected prospectively at 12-18 weeks from normotensive controls (n = 60) and pregnant mothers who developed PE later in pregnancy (n = 33). The plasma samples were subjected to alkaline hydrolysis followed by liquid-liquid extraction to extract total F2-isoPs for later quantification by HPLC-MS/MS. The F2-isoPs were normalized to either plasma volume or polyunsaturated fatty acid (PUFA) levels measured by GC-FID in plasma phospholipids. Early in pregnancy, only the class VI F2-isoP isomers were found at concentrations significantly higher in women developing PE later in pregnancy (+13%; p = 0.0074). Normalization of F2-isoPs to their substrate, AA, or the omega-3 to omega-6 ratio improved the predictability of PE as determined by receiver operating characteristic (from area under the curve of 0.67 to 0.68 and 0.70 respectively). Interestingly, omega-3 fatty acids were 25% higher in the control group than in the PE group (P = 0.0225). Omega-6 PUFAs correlated with F2-Isop isomers only in cases of PE (r > 0.377; P >0.03, Spearman correlation). In sum, this study indicates that specific isomers of class VI are significant predictors of PE. This work also suggests that F2-isoP isomers are not all generated and eliminated to the same extent and are influenced by the PUFA composition of plasma phospholipids.

The injection and the dissolution of alumina in the molten cryolite are crucial steps of the Hall-Heroult process because of their impact on the cell efficiency and stability. A better understanding of the dissolution can support the scientists to optimize the energy consumption of the electrolysis process. This requires the study of the dissolution kinetics of alumina experimentally. In order to follow the evolution of the alumina concentration with good precision after its injection, a semi-automatic mechanical sampling system has been developed. The computer controlled system is able to take molten bath samples at around 1000°C for later chemical and microstructural analysis. The appropriate operation of the sampling system required the resolution of several problems, like the choice of appropriate dimensions and material suitable for a very destructive environment. In the present paper, the design process, including problems and solutions, of a semi-automatic molten cryolite sampling system is presented.

Nitric oxide (NO) is a free radical produced by the action of NO synthases (NOS) and is known to be involved in the regulation of many reproductive events that occur in the oviducts. The oviducts are highly specialized organs that play crucial roles in reproduction by providing an optimal environment for the final maturation of gametes, fertilization, and early embryo development. In this study, we analyzed the expression, hormonal regulation, and cellular distribution of neuronal, inducible, and endothelial NOS in different bovine oviduct segments to better understand the roles played by these enzymes in oviductal functions in vivo. Quantitative RT-PCR analysis revealed that NOS isoforms are hormonally regulated and differentially expressed along the oviduct throughout the estrous cycle. All NOS were highly expressed around the time of estrus, and immunohistochemistry studies determined that neuronal NOS, inducible NOS (iNOS), and endothelial NOS are differentially distributed in cells along the oviduct. Interestingly, our results showed that estradiol selectively up-regulates iNOS expression in the oviduct during the periovulatory period corresponding to the window of ovulation, oocyte transport, and fertilization. The resulting NO production by this high-output NOS may be of crucial importance for reproductive events that occur in the oviduct. This study provided the first demonstration that NO production is hormonally regulated in the mammalian oviducts in vivo. Our results suggest that neuronal NOS, iNOS, and endothelial NOS contribute to oviductal functions in a timely and site-specific manner.

The oviduct plays a crucial role in mammalian reproduction by providing an optimal environment for the final maturation and transport of gametes, fertilization, and early embryonic development. It is now recognized that these reproductive events in vitro can be either negatively or positively affected by reactive oxygen species such as hydrogen peroxide and lipid hydroperoxides. In the current study, we analyzed the expression of the phospholipid hydroperoxide glutathione peroxidase (PHGPx or GPx-4), a selenoenzyme that directly reduces membrane-bound lipid hydroperoxides in the bovine oviduct. Using in situ hybridization, we demonstrated that GPx-4 expression is almost restricted to the oviductal luminal epithelium in contrast to GPx-1, which is widely distributed, and GPx-2 and -3, which are mainly detected in the epithelial cells and lamina propria. Interestingly, real-time quantitative RT-PCR analysis showed that GPx-4 expression was highest during the follicular and postovulatory phases. In addition, GPx-4 expression was highest in the isthmus proximal to the dominant follicle during the follicular stage and remained high during the postovulatory period. This increased in expression of GPx-4 corresponded to increased GPx-4 enzymatic activity. Based on intrauterine infusion of estradiol, we determined that the increase in expression and activity of GPx-4 is estrogen mediated. This work clearly demonstrates that GPx-4 gene expression is influenced by the proximity of the dominant follicle in the oviduct in vivo. We propose that GPx-4 has an important role in the physiological control of peroxide tone in the bordering cells of the oviductal lumen.

Preeclampsia is a leading cause of maternal and neonatal mortality and morbidity. It is a complex syndrome of undetermined etiologic origin, usually diagnosed during the second half of pregnancy, with clinical features of hypertension, proteinuria, and edema. No cure for preeclampsia exists, except premature delivery. There is increasing evidence that oxidative stress is an important contributing factor to the pathogenesis of preeclampsia. Oxidative stress is defined as an imbalance between reactive oxygen species (ROS), such as nitric oxide(NO · ), superoxide anion (O 2 ·↔ ), and hydrogen peroxide (H 2 O 2 ), and antioxidants, favouring an overabundance of ROS. The consequence of an overproduction of ROS can be observed as increased levels of markers of oxidative stress, such as lipid peroxides.Pregnant women affected by preeclampsia may have abnormal ROS production, particularly NO · and O 2 ·↔ , abnormal levels of antioxidant defences, and increased placental lipid peroxidation. Several observations suggest that decreased bioavailability of endothelium-derived NO · , due to oxidative destruction of NO · by ROS, might contribute to the impaired endothelium-dependent vasodilatory responses and multisystemie pathology of preeclampsia, a phenomenon in which antioxidant vitamins may play a beneficial role. This review focuses on the rationale for vitamins C and E supplementation toward prevention of preeclampsia, with an emphasis on the limit of our scientific knowledge concerning the deleterious oxidative events taking place in this pathology.

The synthesis of a 15-membered macrocyclic triene containing all the required substituents of ring A of (+)-aphidicolin (1) is reported. This compound underwent a thermal transannular cycloaddition followed by an intramolecular aldol reaction to yield tetracycle 32 containing 8 chiral centers which is considered a key intermediate for the synthesis of (+)-aphidicolin and related analogs.

The balanced presence of reactive oxygen species and antioxidants has a positive impact on sperm functions, oocyte maturation, fertilization, and embryo development in vitro. The mammalian oviduct is likely to provide an optimal environment for final gamete maturation, sperm-egg fusion, and early embryonic development. However, the expression and distribution of antioxidant enzymes in the bovine oviduct are poorly characterized. We analyzed the mRNA expression and enzymatic activities of major antioxidants glutathione peroxidase (GPx), superoxide dismutase (Cu,ZnSOD), and catalase in the bovine oviduct throughout the estrous cycle. The high levels of expression for GPx-3 in the isthmus were in contrast to expression of GPx1 and GPx-2, which occurred mostly in the ampulla and infundibulum of the oviduct. The highest levels of mRNA expression for GPx-1 were observed toward the end of the estrous cycle before ovulation, whereas GPx-2 was mostly expressed at midcycle. Catalase and Cu,ZnSOD mRNA analyses revealed a homogenous expression along the oviduct. The highest levels of glutathione and enzymatic activities for GPx and catalase occurred at the middle (10‐12 days) and end (18‐20 days) of the estrous cycle, whereas total SOD activity remained constant throughout the estrous cycle in the oviductal fluids. These findings underscore the importance of hydrogen peroxide and hydroperoxide removal by GPx in the oviduct. The heterogeneous expression of antioxidants such as GPx along the oviduct is a possible indication of their physiological role in the events leading to successful fertilization and implantation in vivo. fallopian tubes, female reproductive tract, fertilization, oviduct, ovulatory cycle