Glucocorticoid Effects on the Programming of AT1b Angiotensin Receptor Gene Methylation and Expression in the Rat

Adverse events in pregnancy may ‘programme’ offspring for the later development of cardiovascular disease and hypertension. Previously, using a rodent model of programmed hypertension we have demonstrated the role of the renin-angiotensin system in this process. More recently we showed that a maternal low protein diet resulted in undermethylation of the At1b angiotensin receptor promoter and the early overexpression of this gene in the adrenal of offspring. Here, we investigate the hypothesis that maternal glucocorticoid modulates this effect on fetal DNA methylation and gene expression. We investigated whether treatment of rat dams with the 11β-hydroxylase inhibitor metyrapone, could prevent the epigenetic and gene expression changes we observed. Offspring of mothers subjected to a low protein diet in pregnancy showed reduced adrenal Agtr1b methylation and increased adrenal gene expression as we observed previously. Treatment of mothers with metyrapone for the first 14 days of pregnancy reversed these changes and prevented the appearance of hypertension in the offspring at 4 weeks of age. As a control for non-specific effects of programmed hypertension we studied offspring of mothers treated with dexamethasone from day 15 of pregnancy and showed that, whilst they had raised blood pressure, they failed to show any evidence of Agtr1b methylation or increase in gene expression. We conclude that maternal glucocorticoid in early pregnancy may induce changes in methylation and expression of the Agtr1b gene as these are clearly reversed by an 11 beta-hydroxylase inhibitor. However in later pregnancy a converse effect with dexamethasone could not be demonstrated and this may reflect either an alternative mechanism of this glucocorticoid or a stage-specific influence

Blood Pressure Management in the Very Preterm Infant:More than Just Millimetres

Despite significant advances in many areas of care, the management of low blood pressure and circulatory compromise in the preterm infant continues to be based on quite limited evidence. Deciding when to intervene, and with what to intervene, remains a conundrum at the bedside. In this chapter we explore the aetiology of low blood pressure, we review assessment strategies including new monitoring modalities that may provide a better understanding of the underlying problem and hence direct more appropriate treatments. The evidence for current therapies is reviewed, including the newer inodilators. The future will see a paradigm shift in our current approach to haemodynamic instability and management.</p

Proteolysis during Development and Senescence of Effective and Plant Gene-Controlled Ineffective Alfalfa Nodules.

Plant-controlled ineffective root nodules, conditioned by the in1 gene in Medicago sativa L. cv Saranac, undergo premature senescence and have reduced levels of many late nodulins. To ascertain which factors contribute to premature senescence, we have evaluated proteolysis as it occurs throughout the development of ineffective Saranac (in1Sa) and effective Saranac nodules. Cysteine protease activities with acidic pH optimum and enzyme proteins were present in both genotypes. We found that acidic protease activity was low in effective Saranac nodules throughout their development. In contrast, by 2 weeks after inoculation, acid protease activity of in1Sa nodules was severalfold higher than that of Saranac nodules and remained high until the experiment was terminated 8 weeks later. This increase in protease enzyme activity correlated with an increase in protease protein amounts. Increased protease activity and amount in in1Sa nodules was correlated with a decrease in nodule soluble protein. The time at which in1Sa nodules initially showed increased protease activity corresponded to when symbiosis deteriorated. High levels of phosphoenolpyruvate carboxylase (PEPC) protein were expressed in effective nodules by 12 d after inoculation and expression was associated with low proteolytic enzyme activity. In contrast, although PEPC was expressed in in1Sa nodules, PEPC protein was not found 12 d after inoculation and thereafter. Acidic protease from in1Sa nodules could also degrade purified leghemoglobin. These data indicate that premature senescence and low levels of late nodulins in in1Sa nodules can be correlated in part with increased proteolysis

Benefits of a New Pediatric Triple-Chamber Bag for Parenteral Nutrition in Preterm Infants

International audienceOBJECTIVES: The aim of this study was to evaluate the efficacy, safety, flexibility, and ease of handling and use of the Ped3CB-A 300 mL, the first ready-to-use multichamber parenteral nutrition (PN) system, with optional lipid bag activation, specially designed for administration to preterm infants. MATERIALS AND METHODS: In this prospective, open-label, multicenter, noncomparative, phase III clinical trial, preterm infants were treated with Ped3CB-A for 5 to 10 consecutive days. RESULTS: A total of 113 preterm infants were enrolled in the study and 97 (birth weight 1382 ± 520 g; gestational age 31.2 ± 2.5 weeks; postnatal age administration 5.6 ± 6.1 days) were included in the per protocol analysis accounting for 854 perfusion days. Double-chamber bag activation was used for 32 perfusion days. Macronutrient, electrolyte, and mineral supplements were primarily administered through a Y-line or directly in the activated bag. In all, 199 additions (mainly sodium, 95%) were made to the Ped3CB-A bags on 197 infusion days (23.1%) in 43 infants (44.3%). More than 1 of these nutrients was added to the bag on only 1 perfusion day. Mean and maximum parenteral nutrient intakes were 2.8 ± 0.7 and 3.6 ± 0.8 g amino acids per kilogram per day, and 80 ± 20 and 104 ± 22 kcal * kg(-1) * day(-1). Mean weight gain represented 10.0, 21.5, and 22. 6 g * kg(-1) * day(-1) according to age at inclusion (0-3, 4-7, or >7 days of life). A visual analog scale was completed and produced positive results. No adverse events were attributable to the design of the Ped3CB-A system. CONCLUSIONS: Ped3CB-A provides easy-to-use, well-balanced, and safe nutritional support. Nutritional intakes and weight gain were within the recent PN recommendations in preterm infants

Gastric lipase and other lipolytic enzymes activity in the preterm fed raw, pasteurized or pasteurized-homogenized human milk.

International audienc