Browsing by Author "Rozas, M. Fernanda"
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Item Association between phenotype and deletion size in 22q11.2 microdeletion syndrome: systematic review and meta-analysis(2019) Rozas, M. Fernanda; Benavides, Felipe; León, Luis; Repetto, GabrielaBackground: Chromosome 22q11.2 microdeletion syndrome, a disorder caused by heterozygous loss of genetic material in chromosome region 22q11.2, has a broad range of clinical symptoms. The most common congenital anomalies involve the palate in 80% of patients, and the heart in 50–60% of them. The cause of the phenotypic variability is unknown. Patients usually harbor one of three common deletions sizes: 3, 2 and 1.5 Mb, between low copy repeats (LCR) designated A-D, A-C and A-B, respectively. This study aimed to analyze the association between these 3 deletion sizes and the presence of congenital cardiac and/or palatal malformations in individuals with this condition. A systematic review and meta-analysis were conducted, merging relevant published studies with data from Chilean patients to increase statistical power. Results: Eight articles out of 432 were included; the data from these studies was merged with our own, achieving a total of 1514 and 487 patients to evaluate cardiac and palate malformations, respectively. None of the compared deleted chromosomal segments were statistically associated with cardiac defects (ORAB v/s AC-AD: 0.654 [0.408–1.046]; OR AD v/s AB-AC: 1.291 [0.860–1.939]) or palate anomalies (ORAB v/s AC-AD: 1.731 [0.708–4.234]; OR AD v/s AB-AC: 0.628 [0.286–1.382]). Conclusions: The lack of association between deletion size and CHD or PA found in this meta-analysis suggests that deletion size does not explain the incomplete penetrance of these 2 major manifestations, and that the critical region for the development of heart and palatal abnormalities is within LCR A-B, the smallest region of overlap among the three deletion sizes.Item Evaluación de calidad de las guías de práctica clínica de los 80 problemas de salud del régimen de garantías explícitas en salud(Sociedad Medica de Santiago, 2016) Rodriguez, Maria; Pineda, Ignacio; Rozas, M. FernandaBackground: High quality practice guidelines are of utmost importance in clinical medicine. Aim: To evaluate the methodological quality of Clinical Practice Guidelines (CPG) for 80 high burden health conditions included in the “Explicit Guarantees in Healthcare” (EGH) program available on July 2014, elaborated and published by the Ministry of Health of Chile. Material and Methods: A cross-sectional observational study using the Appraisal of Guidelines Research and Evaluation (AGREE II) instrument to evaluate the methodological quality of the current CPGs for EGH. Two reviewers assessed each CPG independently, obtaining standardized scores according for each dimension included in the AGREE II instrument. Results: Eighty one CPGs were evaluated. They were generally considered of reasonable quality, obtaining high scores in the following domains: Scope and Purpose (81.3%), Clarity of Presentation (78.6%) and Editorial Independence (76.5%). The following domains had a score under 60%: Stakeholder Involvement (51.3%), Rigor of Development (41.4%) and Applicability (33.6%). Conclusions: The CPGs elaborated for the EGH program have high scores in domains such as the Scope and Purpose, Clarity of Presentation and Editorial Independence. Their scores in other dimensions such as Stakeholder Involvement, Rigor of Development and Applicability can be still improved.Item Role of ROS/RNS in Preeclampsia: Are Connexins the Missing Piece?(2020) Rozas, M. Fernanda; Casanello, Paola; Retamal, MauricioPreeclampsia is a pregnancy complication that appears after 20 weeks of gestation and is characterized by hypertension and proteinuria, affecting both mother and offspring. The cellular and molecular mechanisms that cause the development of preeclampsia are poorly understood. An important feature of preeclampsia is an increase in oxygen and nitrogen derived free radicals (reactive oxygen species/reactive nitrogen species (ROS/RNS), which seem to be central players setting the development and progression of preeclampsia. Cell-to-cell communication may be disrupted as well. Connexins (Cxs), a family of transmembrane proteins that form hemichannels and gap junction channels (GJCs), are essential in paracrine and autocrine cell communication, allowing the movement of signaling molecules between cells as well as between the cytoplasm and the extracellular media. GJCs and hemichannels are fundamental for communication between endothelial and smooth muscle cells and, therefore, in the control of vascular contraction and relaxation. In systemic vasculature, the activity of GJCs and hemichannels is modulated by ROS and RNS. Cxs participate in the development of the placenta and are expressed in placental vasculature. However, it is unknown whether Cxs are modulated by ROS/RNS in the placenta, or whether this potential modulation contributes to the pathogenesis of preeclampsia. Our review addresses the possible role of Cxs in preeclampsia, and the plausible modulation of Cxs-formed channels by ROS and RNS. We suggest these factors may contribute to the development of preeclampsia.