Maternal demographics and hemodynamics for the prediction of fetal growth restriction at booking, in pregnancies at high risk for placental insufficiency.

INTRODUCTION: Fetal growth restriction (FGR) is associated with poor perinatal outcomes. Screening and prevention tools for FGR, such as uterine artery Doppler imaging and aspirin, underperform in high-risk groups, compared with general antenatal populations. There is a paucity of sensitive screening tests for the early prediction of FGR in high-risk pregnancies. MATERIALS AND METHODS: This was a prospective observational study based in a dedicated antenatal hypertension clinic at a tertiary UK hospital. We assessed maternal demographic and central hemodynamic variables as predictors for FGR in a group of women at high risk for placental insufficiency due to chronic hypertension (n = 55) or a history of hypertension in a previous pregnancy (n = 71). Outcome variables were birthweight z-score as well as development of FGR (defined as birthweight below the 5th or 3rd centile). Maternal hemodynamics were assessed using a noninvasive transthoracic bioreactance monitor (Cheetah NICOM). RESULTS: The mean gestation at presentation was 13.6 (range: 8.5-19.5) weeks. Sixteen women delivered babies below the 5th centile. Ten of these were below the 3rd centile. Independent predictors of birthweight z-score were body surface area, peripheral vascular resistance and white ethnicity (R(2) = 0.26, p < 0.0001). Independent predictors of FGR were maternal height and cardiac output. The area under the receiver operator characteristic curve for prediction of FGR was 0.915 (95% CI 0.859-0.972) and 0.9079 (95% CI 0.823-0.990) for FGR below the 5th and 3rd centiles, respectively. CONCLUSION: In women with chronic hypertension or a history of hypertension in a previous pregnancy, maternal size and cardiac output at booking provide a sensitive screening tool for FGR.

Risk adapted transmission prophylaxis to prevent vertical HIV-1 transmission: effectiveness and safety of an abbreviated regimen of postnatal oral zidovudine.

BACKGROUND: Antiretroviral drugs including zidovudine (ZDV) are effective in reducing HIV mother to child transmission (MTCT), however safety concern remains. The optimal duration of postnatal ZDV has not been established in clinical studies and there is a lack of consensus regarding optimal management. The objective of this study was to investigate the effectiveness and safety of a risk adapted two week course of oral postnatal ZDV as part of a combined intervention to reduce MTCT. METHODS: 118 mother infant pairs were treated according to the German-Austrian recommendations for HIV therapy in pregnancy and in HIV exposed newborns between 2000-2010. In the absence of factors associated with an increased HIV-1 transmission risk, children were assigned to the low risk group and treated with an abbreviated postnatal regimen with oral ZDV for 2 weeks. In the presence of risk factors, postnatal ZDV was escalated accordingly. RESULTS: Of 118 mother-infant pairs 79 were stratified to the low risk group, 27 to the high risk group and 11 to the very high risk group for HIV-1 MTCT. 4 children were lost to follow up. Overall Transmission risk in the group regardless of risk factors and completion of prophylaxis was 1.8% (95% confidence interval (CI) 0.09-6.6). If transmission prophylaxis was complete, transmission risk was 0.9% (95% CI 0.01-5.7). In the low risk group receiving two week oral ZDV transmission risk was 1.4% (95% CI 0.01-8.4) CONCLUSION: These data demonstrate the effectiveness of a short neonatal ZDV regimen in infants of women on stable ART and effective HIV-1 suppression. Further evaluation is needed in larger studies.

Centrifugal precipitation chromatography, a powerful technique for the isolation of active enzymes from tea leaves (Camellia sinensis).

Centrifugal precipitation chromatography was developed approximately 10 years ago. In contrast to other counter-current chromatographic techniques, the centrifugal precipitation chromatography system is operated with two mutually miscible solutions separated by a cut-off membrane. Centrifugal precipitation chromatography was firstly introduced for the separation of proteins using an ammonium sulfate gradient. In this study we describe a novel approach using solvent-based protein precipitation for the isolation of active plant enzymes from tea leaves (Camellia sinensis) by centrifugal precipitation chromatography. We developed a gradient based on acetone and Tris-buffer, because the biological activity of carotenases in tea leaves cannot be preserved in the presence of ammonium sulfate. Parameters such as the critical solvent concentration, flow rate, buffer concentration, and sample load were determined and/or optimized. Subsequently, the newly developed separation protocol was successfully used for the isolation of active carotenoid cleavage enzymes from tea leaves. The isolated enzymes showed high enzymatic activities and purities and could be directly used for enzymatic assays and structure elucidation.