Brenda Valenzuela-Alcaraz

Bio: Brenda Valenzuela-Alcaraz is an academic researcher from University of Barcelona. The author has contributed to research in topics: Fetal echocardiography & Population. The author has an hindex of 15, co-authored 37 publications receiving 669 citations. Previous affiliations of Brenda Valenzuela-Alcaraz include Hospital Sant Joan de Déu Barcelona & National Autonomous University of Mexico.

Assisted Reproductive Technologies are Associated with Cardiovascular Remodeling in Utero that Persists Postnatally

Abstract: Background—Assisted reproductive technologies (ARTs) have been shown to be associated with general vascular dysfunction in late childhood. However, it is unknown whether cardiac remodeling is also present and if these changes already manifest in prenatal life. Our aim was to assess fetal and infant (6 months of age) cardiovascular function in ART pregnancies. Methods and Results—This prospective cohort study included 100 fetuses conceived by ART and 100 control pregnancies. ART fetuses showed signs of cardiovascular remodeling, including a more globular heart with thicker myocardial walls, decreased longitudinal function (tricuspid ring displacement in controls: median, 6.5 mm [interquartile range, 6.1–7.1 mm]; tricuspid ring displacement in ART: 5.5 mm [interquartile range, 5.1–6.1]; P<0.001), impaired relaxation, and dilated atria (atrial area in controls, 1.46 cm2 [interquartile range, 1.2–1.5 cm2]; atrial area in ART, 1.6 cm2 [interquartile range, 1.3–1.8 cm2]; P<0.001). Additionally, ART infants show...

Fetal cardiovascular remodeling persists at 6 months in infants with intrauterine growth restriction.

Abstract: This work was supported by grants from Instituto de Salud Carlos III (grant numbers PI11/00051, PI12/00801, PI11/01709) and from the Ministerio de Economia y Competitividad (grant number SAF2012‐37196), and cofinanced by the Fondo Europeo de Desarrollo Regional de la Union Europea ‘Una manera de hacer Europa’, Fundacion Mutua Madrilena, Fundacio Agrupacio Premi Ambit de la Infancia (Spain) and Cerebra Foundation for the Brain Injured Child (Carmarthen, Wales, UK). B.V.A. was supported by Programa de Ayudas Postdoctorales FI Agaur (2013FI_B 00667). M.C.L. and B.V.A. wish to express their gratitude to the Mexican National Council of Science and Technology (CONACyT, Mexico City, Mexico) for partially supporting their predoctoral studies at Hospital Clinic, Barcelona, Spain.

SIRT3-mediated inhibition of FOS through histone H3 deacetylation prevents cardiac fibrosis and inflammation.

Abstract: Sirtuin 3 (SIRT3) is a deacetylase that modulates proteins that control metabolism and protects against oxidative stress. Modulation of SIRT3 activity has been proposed as a promising therapeutic target for ameliorating metabolic diseases and associated cardiac disturbances. In this study, we investigated the role of SIRT3 in inflammation and fibrosis in the heart using male mice with constitutive and systemic deletion of SIRT3 and human cardiac AC16 cells. SIRT3 knockout mice showed cardiac fibrosis and inflammation that was characterized by augmented transcriptional activity of AP-1. Consistent with this, SIRT3 overexpression in human and neonatal rat cardiomyocytes partially prevented the inflammatory and profibrotic response induced by TNF-α. Notably, these effects were associated with a decrease in the mRNA and protein levels of FOS and the DNA-binding activity of AP-1. Finally, we demonstrated that SIRT3 inhibits FOS transcription through specific histone H3 lysine K27 deacetylation at its promoter. These findings highlight an important function of SIRT3 in mediating the often intricate profibrotic and proinflammatory responses of cardiac cells through the modulation of the FOS/AP-1 pathway. Since fibrosis and inflammation are crucial in the progression of cardiac hypertrophy, heart failure, and diabetic cardiomyopathy, our results point to SIRT3 as a potential target for treating these diseases.

Value of annular M-mode displacement vs tissue Doppler velocities to assess cardiac function in intrauterine growth restriction.

Abstract: Objective To compare the ability of two different methods for longitudinal annular motion measurement, M-mode and tissue Doppler imaging (TDI), to demonstrate cardiac dysfunction in intrauterine-growthrestricted (IUGR) fetuses. Methods Cardiac longitudinal annular motion in the basal free wall of the left ventricle (mitral annulus), interventricular septum and tricuspid annulus was assessed in 23 early-onset IUGR cases and 43 controls by TDI (annular peak velocities) and M-mode (displacement). Results All annular parameters were significantly decreased in the IUGR group with respect to controls using both methods. M-mode showed a trend towards equal performance as classifier between cases and controls, as compared to TDI, mainly in the tricuspid annulus. Conclusions Both M-mode and TDI demonstrate annular motion changes and consequently cardiac dysfunction in IUGR fetuses. M-mode imaging is simpler to perform and could be as sensitive as TDI for detecting subtle changes. Copyright  2012 ISUOG. Published by John Wiley & Sons Ltd.

Clinical risk factors for pre-eclampsia determined in early pregnancy: systematic review and meta-analysis of large cohort studies

Abstract: Objective To develop a practical evidence based list of clinical risk factors that can be assessed by a clinician at ≤16 weeks’ gestation to estimate a woman’s risk of pre-eclampsia. Design Systematic review and meta-analysis of cohort studies. Data sources PubMed and Embase databases, 2000-15. Eligibility criteria for selecting studies Cohort studies with ≥1000 participants that evaluated the risk of pre-eclampsia in relation to a common and generally accepted clinical risk factor assessed at ≤16 weeks’ gestation. Data extraction Two independent reviewers extracted data from included studies. A pooled event rate and pooled relative risk for pre-eclampsia were calculated for each of 14 risk factors. Results There were 25 356 688 pregnancies among 92 studies. The pooled relative risk for each risk factor significantly exceeded 1.0, except for prior intrauterine growth restriction. Women with antiphospholipid antibody syndrome had the highest pooled rate of pre-eclampsia (17.3%, 95% confidence interval 6.8% to 31.4%). Those with prior pre-eclampsia had the greatest pooled relative risk (8.4, 7.1 to 9.9). Chronic hypertension ranked second, both in terms of its pooled rate (16.0%, 12.6% to 19.7%) and pooled relative risk (5.1, 4.0 to 6.5) of pre-eclampsia. Pregestational diabetes (pooled rate 11.0%, 8.4% to 13.8%; pooled relative risk 3.7, 3.1 to 4.3), prepregnancy body mass index (BMI) >30 (7.1%, 6.1% to 8.2%; 2.8, 2.6 to 3.1), and use of assisted reproductive technology (6.2%, 4.7% to 7.9%; 1.8, 1.6 to 2.1) were other prominent risk factors. Conclusions There are several practical clinical risk factors that, either alone or in combination, might identify women in early pregnancy who are at “high risk” of pre-eclampsia. These data can inform the generation of a clinical prediction model for pre-eclampsia and the use of aspirin prophylaxis in pregnancy.

Echocardiographic Studies of the Human Fetus: Prenatal Diagnosis of Congenital Heart Disease and Cardiac Dysrhythmias

Abstract: During obstetrical ultrasound examinations, 200 M-mode and 35 real-time two-dimensional echocardiographic studies were performed on 180 fetuses of high-risk pregnancies. Fetal gestational ages ranged from 18 to 41 weeks. M-mode "sweeps" demonstrating mitral- and septal-aortic fibrous continuity were obtained in 115 studies. Paradoxic septal motion in 50 fetuses suggested relarive right ventricular volume loading. Congenital cardiac malformations were accurately diagnosed in a 34-week fetus with pulmonary atresia and hypoplastic right ventricle and in a 28-week fetus with a univentricular heart. Congenital complete atrioventricular block was diagnosed in a 28-week fetus and atrial flutter with variable atrioventricular block was diagnosed in a 38-week fetus. The use of echocardiographic studies to evaluate cardiac structure and rhythm in utero assists in counseling prospective parents and in planning postnatal management for their offspring.

The health of children conceived by ART: 'the chicken or the egg?'

Abstract: Worldwide, more than 7 million children have now been born after ART: these delivery rates are steadily rising and now comprise 2-6% of births in the European countries. To achieve higher pregnancy rates, the transfer of two or more embryos was previously the gold standard in ART. However, recently the practise has moved towards a single embryo transfer policy to avoid multiple births. The positive consequences of the declining multiple birth rates after ART are decreasing perinatal risks and overall improved health for the ART progeny. In this review we summarize the risks for short- and long-term health in ART singletons and discuss if the increased health risks are associated with intrinsic maternal or paternal factors related to subfertility or to the ART treatments per se. Although the risks are modest, singletons born after ART are more likely to have adverse perinatal outcomes compared to spontaneously conceived (SC) singletons dependent on the ART method. Fresh embryo transfer is associated with a higher risk of small for gestational age babies (SGA), low birthweight and preterm birth (PTB), while frozen embryo transfer is associated with large-for-gestational age babies and pre-eclampsia. ICSI may be associated with a higher risk of birth defects and transferral of the poor semen quality to male progeny, while oocyte donation is associated with increased risk of SGA and pre-eclampsia. Concerning long-term health risks, the current evidence is limited but suggests an increased risk of altered blood pressure and cardiovascular function in ART children. The data that are available for malignancies seem reassuring, while results on neurodevelopmental health are more equivocal with a possible association between ART and cerebral palsy. The laboratory techniques used in ART may also play a role, as different embryo culture media give rise to different birthweights and growth patterns in children, while culture to blastocyst stage is associated with PTB. In addition, children born after ART have altered epigenetic profiles, and these alterations may be one of the key areas to explore to improve our understanding of adverse child outcomes after ART. A major challenge for research into adverse perinatal outcomes is the difficulty in separating the contribution of infertility per se from the ART treatment (i.e. 'the chicken or the egg'?). Choosing and having access to the appropriate control groups for the ART children in order to eliminate the influence of subfertility per se (thereby exploring the pure association between ART and child outcomes) is in itself challenging. However, studies including children of subfertile couples or of couples treated with milder fertility treatments, such as IUI, as controls show that perinatal risks in these cohorts are lower than for ART children but still higher than for SC indicating that both subfertility and ART influence the future outcome. Sibling studies, where a mother gave birth to both an ART and a SC child, support this theory as ART singletons had slightly poorer outcomes. The conclusion we can reach from the well designed studies aimed at disentangling the influence on child health of parental and ART factors is that both the chicken and the egg matter.