GUEVARA RAMÍREZ, ALEXANDRA PATRICIA
Preferred name
GUEVARA RAMÍREZ, ALEXANDRA PATRICIA
Main Affiliation
CIGG - Centro de Investigación Genética y Genómica
Web Site
ORCID
0000-0002-4829-3653
Scopus Author ID
57195725827
69 results
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Item type:Publication, Genotyping the High Altitude Mestizo Ecuadorian Population Affected with Prostate Cancer(Hindawi Limited, 2017); Santiago Guerrero<jats:p>Prostate cancer (PC) is the second most commonly diagnosed type of cancer in males with 1,114,072 new cases in 2015. The MTHFR enzyme acts in the folate metabolism, which is essential in methylation and synthesis of nucleic acids. MTHFR C677T alters homocysteine levels and folate assimilation associated with DNA damage. Androgens play essential roles in prostate growth. The SRD5A2 enzyme metabolizes testosterone and the V89L polymorphism reduces in vivo SRD5A2 activity. The androgen receptor gene codes for a three-domain protein that contains two polymorphic trinucleotide repeats (CAG, GGC). Therefore, it is essential to know how PC risk is associated with clinical features and polymorphisms in high altitude Ecuadorian mestizo populations. We analyzed 480 healthy and 326 affected men from our three retrospective case-control studies. We found significant association between MTHFR C/T (odds ratio [OR] = 2.2;<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M1"><mml:mi>P</mml:mi><mml:mo>=</mml:mo><mml:mn fontstyle="italic">0.009</mml:mn></mml:math>), MTHFR C/T+T/T (OR = 2.22;<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M2"><mml:mi>P</mml:mi><mml:mo>=</mml:mo><mml:mn fontstyle="italic">0.009</mml:mn></mml:math>), and PC. The SRD5A2 A49T substitution was associated with higher pTNM stage (OR = 2.88;<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M3"><mml:mi>P</mml:mi><mml:mo>=</mml:mo><mml:mn fontstyle="italic">0.039</mml:mn></mml:math>) and elevated Gleason grade (OR = 3.15;<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M4"><mml:mi>P</mml:mi><mml:mo>=</mml:mo><mml:mn fontstyle="italic">0.004</mml:mn></mml:math>). Additionally, patients with ≤21 CAG repeats have an increased risk of developing PC (OR = 2.99;<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M5"><mml:mi>P</mml:mi><mml:mo><</mml:mo><mml:mn fontstyle="italic">0.001</mml:mn></mml:math>). In conclusion, genotype polymorphism studies are important to characterize genetic variations in high altitude mestizo populations.</jats:p>Scopus© Citations 8 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Ancestral analysis of a Native American Ecuadorian family with congenital insensitivity to pain with anhidrosis(Elsevier BV, 2019-12); ; - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Ancestry study in Ecuadorian population with multiple myeloma(Ovid Technologies (Wolters Kluwer Health), 2017)Scopus© Citations 1 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Exploring Atrial Fibrillation: Understanding the Complex Relation Between Lifestyle and Genetic Factors(Elmer Press, Inc., 2024-08); ; Viviana A. Ruiz-PozoCardiovascular diseases (CVDs) are the leading cause of death worldwide across diverse ethnic groups. Among these, atrial fibrillation (AF) stands as one of the most prevalent types of arrhythmias and the primary cause of stroke. Risk factors associated with AF include alcohol consumption, aging, high blood pressure, hypertension, inflammation, and genetic factors. A family history of CVD could indicate an increased risk. Consequently, genetic, and genomic testing should be performed to identify the molecular etiology of CVDs and assess at-risk patients. It is important to note that CVDs are the results of the complex interplay of genes and environmental factors, including ethnicity. In this case, the proband’s clinic story includes a history of smoking abuse for 10 years (10 cigarettes per day), obesity, hypertension, and an associated familial history. These risk factors, along with genetic variants, could trigger the early onset of AF. In recent years, genetic and genomic studies have significantly advanced our understanding of CVD etiology, given that next-generation sequencing (NGS) allows for the identification of genetic variants that could contribute to these pathologies. Furthermore, NGS facilitates early diagnosis, personalized pharmacological approaches, and identification of novel biomarkers. Thus, NGS is a valuable tool in CVD management. However, such studies are limited in Ecuador, a low- and middle-income country. Several challenges contribute to this gap, encompassing economic, infrastructural, and educational obstacles. Notably, the cost of genetic and genomic studies may also pose a barrier, restricting access to a portion of the population. In this case report, we present a 56-year-old Ecuadorian woman, who has been diagnosed with AF; however, after performing NGS no disease-associated variants were found, despite having strong clinical signs and symptoms. In summary, this case report contributes valuable insights into the complex interplay between genetic and lifestyle factors in the development and management of AF. The case report aims to underscore the potential impact of genetic variants on disease risk, even when classified as variants of uncertain significance, and the importance of an integral approach to patient care that includes genetic screening, lifestyle interventions, and tailored pharmacological treatment.Scopus© Citations 5 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Effect of diet on the microbiota and immune system in patients with systemic lupus erythematosus(Informa UK Limited, 2024-11-30); ; ; ; Systemic lupus erythematosus (SLE) is a chronic autoimmune disease characterized by widespread inflammation and organ damage. Studies indicate that diet significantly influences the gut microbiota, which, in turn, affects the immune system. This article explores gut microbiota dysbiosis in SLE patients and potential mechanisms related to dietary interventions and immune function. It highlights specific dietary patterns, such as a high-fibre diet and the Mediterranean diet, that may modulate the diversity and activity of the gut microbiota. The interaction between altered microbiota and immune responses, including the regulation of inflammatory cytokines, intestinal barrier permeability, and autoantibody production is examined. This review highlights the importance of personalized dietary strategies to modulate the diversity and activity of the gut microbiota by enhancing the immune response and potentially mitigating disease progression.Scopus© Citations 8 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, A deep analysis using panel-based next-generation sequencing in an Ecuadorian pediatric patient with anaplastic astrocytoma: a case report(Springer Science and Business Media LLC, 2020-08-31); ; Santiago Guerrero<jats:title>Abstract</jats:title><jats:sec><jats:title>Background</jats:title><jats:p>Anaplastic astrocytoma is a rare disorder in children from 10 to 14 years of age, with an estimated 0.38 new cases per 100,000 people per year worldwide. Panel-based next-generation sequencing opens new possibilities for diagnosis and therapy of rare diseases such as this one. Because it has never been genetically studied in the Ecuadorian population, we chose to genetically characterize an Ecuadorian pediatric patient with anaplastic astrocytoma for the first time. Doing so allows us to provide new insights into anaplastic astrocytoma diagnosis and treatment.</jats:p></jats:sec><jats:sec><jats:title>Case presentation</jats:title><jats:p>Our patient was a 13-year-old Mestizo girl with an extensive family history of cancer who was diagnosed with anaplastic astrocytoma. According to ClinVar, SIFT, and PolyPhen, the patient harbored 354 genomic alterations in 100 genes. These variants were mostly implicated in deoxyribonucleic acid (DNA) repair. The top five most altered genes were<jats:italic>FANCD2</jats:italic>,<jats:italic>NF1</jats:italic>,<jats:italic>FANCA</jats:italic>,<jats:italic>FANCI</jats:italic>, and<jats:italic>WRN.</jats:italic>Even though<jats:italic>TP53</jats:italic>presented only five mutations, the rs11540652 single-nucleotide polymorphism classified as pathogenic was found in the patient and her relatives; interestingly, several reports have related it to Li-Fraumeni syndrome. Furthermore,<jats:italic>in silico</jats:italic>analysis using the Open Targets Platform revealed two clinical trials for pediatric anaplastic astrocytoma (studying cabozantinib, ribociclib, and everolimus) and 118 drugs that target the patient’s variants, but the studies were not designed specifically to treat pediatric anaplastic astrocytoma.</jats:p></jats:sec><jats:sec><jats:title>Conclusions</jats:title><jats:p>Next-generation sequencing allows genomic characterization of rare diseases; for instance, this study unraveled a pathogenic single-nucleotide polymorphism related to Li-Fraumeni syndrome and identified possible new drugs that specifically target the patient’s variants. Molecular tools should be implemented in routine clinical practice for early detection and effective preemptive intervention delivery and treatment.</jats:p></jats:sec>Scopus© Citations 2 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Molecular mechanisms of semaglutide and liraglutide as a therapeutic option for obesity(Frontiers Media SA, 2024-04-29); ; ; Obesity, a chronic global health problem, is associated with an increase in various comorbidities, such as cardiovascular disease, type 2 diabetes mellitus, hypertension, and certain types of cancer. The increasing global prevalence of obesity requires research into new therapeutic strategies. Glucagon-like peptide-1 receptor agonists, specifically semaglutide and liraglutide, designed for type 2 diabetes mellitus treatment, have been explored as drugs for the treatment of obesity. This minireview describes the molecular mechanisms of semaglutide and liraglutide in different metabolic pathways, and its mechanism of action in processes such as appetite regulation, insulin secretion, glucose homeostasis, energy expenditure, and lipid metabolism. Finally, several clinical trial outcomes are described to show the safety and efficacy of these drugs in obesity management.Scopus© Citations 63 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Analysis of Racial/Ethnic Representation in Select Basic and Applied Cancer Research Studies(Springer Science and Business Media LLC, 2018-09-18)Scopus© Citations 138 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Mutational Analysis of Oncogenic AKT1 Gene Associated with Breast Cancer Risk in the High Altitude Ecuadorian Mestizo Population(Hindawi Limited, 2018-07-03)Scopus© Citations 27 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Genomic analysis of a novel pathogenic variant in the gene LMNA associated with cardiac laminopathies found in Ecuadorian siblings: A case report(Frontiers Media SA, 2023-03-21); ; Scopus© Citations 5