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
75 results
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Item type:Publication, Molecular Mechanisms and Therapeutic Perspectives of Gut Microbiota, Autophagy, and Apoptosis in Cholangiocarcinoma PathophysiologyCholangiocarcinoma (CCA) is an aggressive malignancy of the biliary tract with rising global incidence and limited treatment options. Its pathogenesis involves a complex interplay of genetic mutations, epigenetic dysregulation, inflammatory signaling, and environmental influences. Emerging evidence highlights the pivotal role of the gut–liver axis and microbiota dysbiosis in shaping biliary homeostasis and disease progression. Alterations in microbial composition disrupt apoptosis and autophagy, two key processes regulating cell survival and death, thereby contributing to tumorigenesis, metastasis, and therapy resistance. Specific taxa, including Enterococcus, Escherichia coli, Pseudomonas, Bifidobacterium, and Bacillus, demonstrate strain-dependent effects, acting either as tumor promoters through genotoxic metabolites and immune evasion or as potential tumor suppressors by inducing apoptosis and immune activation. These findings underscore the context-dependent roles of microbiota in CCA biology. Importantly, microbiota modulation offers novel therapeutic opportunities. Dietary interventions such as probiotics, prebiotics, and nutritional strategies, alongside innovative microbiome-targeted therapies, hold promise for restoring microbial balance, enhancing antitumor immunity, and improving patient outcomes. This review integrates current molecular and microbiological evidence to propose the gut microbiota as both a biomarker and a therapeutic target in CCA, opening avenues for precision medicine approaches in hepatobiliary oncologyScopus© Citations 2 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Clinical, cytogenetic, and genomic analyses of an Ecuadorian subject with Klinefelter syndrome, recessive hemophilia A, and 1;19 chromosomal translocation: a case report(Springer Science and Business Media LLC, 2022-09-05); ; <jats:title>Abstract</jats:title><jats:sec> <jats:title>Background</jats:title> <jats:p>Hemophilia A is considered one of the most common severe hereditary disorders. It is an X-linked recessive disease caused by a deficiency or lack of function of the blood clotting factor VIII. Klinefelter syndrome is a genetic disorder that affects male individuals due to one or more extra X chromosomes, present in all cells or with mosaicism. The aneuploidy is due to either mitotic or meiotic chromosome non-disjunction. Chromosomal translocations are a group of genome abnormalities in which a region or regions of a chromosome break and are transferred to a nonhomologous chromosome or a new location in the same chromosome.</jats:p> </jats:sec><jats:sec> <jats:title>Case presentation</jats:title> <jats:p>Our subject was born in Ecuador at 36 weeks of gestation by vaginal delivery. At 3 months old, the Factor VIII activity measure showed a 23.7% activity indicating a diagnosis of mild hemophilia A. At 1 year old, the karyotype showed an extra X chromosome, consistent with a diagnosis of Klinefelter syndrome, and a translocation between the long arms of chromosomes 1 and 19, at positions q25 and q13, respectively.</jats:p> </jats:sec><jats:sec> <jats:title>Conclusions</jats:title> <jats:p>Klinefelter syndrome and hemophilia are a rare combination. In the present case report, the subject presents both, meaning that he has inherited one X chromosome from the father and one X chromosome from the mother. Since the father has severe hemophilia A; and the subject presents a below 40% Factor VIII activity, a skewed X inactivation is suggested. Additionally, the proband presents a translocation with the karyotype 47,XXY,t(1;19)(q25;q13). No similar report with phenotypic consequences of the translocation was found. The present report highlights the importance of a correct diagnosis, based not only on the clinical manifestations of a disease but also on its genetic aspects, identifying the value of integrated diagnostics. The subject presents three different genetic alterations, Klinefelter syndrome, hemophilia A, and a 1;19 chromosomal translocation.</jats:p> </jats:sec>Scopus© Citations 2 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Genetic diet interactions of ACE: the increased hypertension predisposition in the Latin American population(Frontiers Media SA, 2023-10-26); ; Scopus© Citations 16 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Next-Generation sequencing in a Native American patient with sea-blue histiocytosis: A case report and genomic analysis(Medwave Estudios Limitada, 2025-08-08); ; ; This study presents a case of a 25-year-old Native American woman from Otavalo, Ecuador, diagnosed with sea-blue histiocytosis and myelodysplastic syndrome. Bone marrow aspiration revealed sea-blue histiocytes, and next-generation sequencing identified a likely pathogenic stop-gain mutation in the gene, associated with myelodysplastic syndrome. Additionally, variants of uncertain significance were found in the and genes. Ancestral analysis showed a predominantly Native American composition, suggesting a potential genetic predisposition specific to Andean communities. The report underscores the importance of understanding genetic and ancestral backgrounds in diagnosing and managing hematological disorders. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Heavy metals in the diet: unraveling the molecular pathways linked to neurodegenerative disease risk(Informa UK Limited, 2024-12-03); ; ; ; Neurodegenerative diseases (NDDs) affect millions of lives worldwide. They constitute a group of neurological disorders with shared common features, including impaired cognition, behavior, memory, and motor functions. These conditions arise due to the gradual degeneration of neurons within the nervous system. Even though, each pathology presents diverse etiologies and develops in different brain sites, they may share cellular and molecular mechanisms, such as inflammation, protein aggregation, and DNA and RNA defects. Heavy metal contamination is a global public health concern, given that anthropogenic activities like paint manufacturing, mining, and oil refining contribute substantially to heavy metal pollution. Consequently, studies have investigated its potential etiological factors in neurodegenerative diseases. This review examines the impact of dietary exposure to heavy metals, specifically mercury, cadmium, lead, chromium, arsenic, and zinc, on the development and progression of neurodegenerative diseases. Evidence from a range of studies indicates that these metals play a significant role in advancing these diseases by disrupting essential cellular and molecular functions, including the induction of oxidative stress and impairments in mitochondrial function. These findings underscore the need for further research to elucidate toxicological mechanisms and develop preventive strategies, such as chelation therapies and environmental remediation. Addressing these risks is especially critical to protect neurocognitive health, particularly in aging populations.Scopus© Citations 9 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Oncology and Pharmacogenomics Insights in Polycystic Ovary Syndrome: An Integrative Analysis(Frontiers Media SA, 2020-10-26)Scopus© Citations 33 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Interplay between endogenous hormones and immune systems in human metapneumovirus pathogenesis and management(Frontiers Media SA, 2025-03-18); ; ; ; The present review explores the role of endogenous hormones, such as cortisol, melatonin, thyroid hormones, sex hormones, and insulin, in the modulation of the immune response to a human metapneumovirus (hMPV) infection. hMPV is a respiratory pathogen responsible for severe infections, particularly in vulnerable populations like children and the elderly. The virus triggers inflammatory responses through various molecular processes, including cytokine production and immune signaling pathways. Notably, these processes can be influenced by endocrine factors, such as hormones. Cortisol, through hypothalamic-pituitary-adrenal (HPA) axis activation, modulates inflammation but may contribute to immunosuppression. Melatonin inhibits the NLRP3 inflammasome, reducing lung inflammation. Thyroid hormones regulate immune responses via nuclear factor kappa B (NF-κB) and JAK/STAT pathways, while hypothyroidism may alter infection severity. Sex hormones, particularly estrogens, enhance antiviral immunity, whereas androgens may have variable effects on immune modulation. Insulin influences inflammation through NF-κB suppression, with insulin resistance potentially worsening viral pathogenesis. Therapeutic implications suggest that modulating these hormonal pathways could aid in hMPV management. Strategies such as hormone therapy, glucocorticoid regulation, and nanoparticle-based drug delivery are potential routes of intervention. The aim of the present review is to understand the complex interplay between endogenous hormones and the immune system during an hMPV infection by describing the complex molecular mechanisms associated with these processes.Scopus© Citations 10 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, A quick guide for using Microsoft OneNote as an electronic laboratory notebook(Public Library of Science (PLoS), 2019-05-09); Alberto IndacocheaScopus© Citations 15 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Identification of mutations on the EMD and EYA4 genes associated with Emery–Dreifuss muscular dystrophy and deafness: a case report(Frontiers Media SA, 2023-05-12); ; ; José Luis Laso-Bayas<jats:sec><jats:title>Introduction</jats:title><jats:p>Hearing loss is the most common sensory disability, and it is estimated that 50% of cases are caused by genetic factors. One of the genes associated with deafness is the eyes absent homolog 4 (<jats:italic>EYA4</jats:italic>) gene, a transcription factor related to the development and function of the inner ear. Emery–Dreifuss muscular dystrophy is a rare inherited disease characterized by atrophy and weakness of the humeroperoneal muscles, multi-joint contractures, and cardiac manifestations. It is inherited in an autosomal-dominant, X-linked, or less frequently autosomal recessive manner; one of the genes associated with EDMD is the emerin (<jats:italic>EMD)</jats:italic> gene.</jats:p></jats:sec><jats:sec><jats:title>Case description</jats:title><jats:p>A total of two Ecuadorian siblings aged 57 (Subject A) and 55 (Subject B) were diagnosed with deafness and an unspecified type of muscular dystrophy based on family history and clinical findings. Next-generation sequencing (NGS) using the TruSight Cardio and Inherited Disease kits at the Centro de Investigación Genética y Genómica CIGG, Universidad UTE, was performed. The genetic analyses showed two mutations: a stop mutation in exon 11/20 (NM_004100.4:c.940G&gt;T) of the <jats:italic>EYA4</jats:italic> gene and a missense mutation in exon 6 (NM_000117.2:c.548C&gt;G) of the <jats:italic>EMD</jats:italic> gene.</jats:p></jats:sec><jats:sec><jats:title>Discussion and conclusion</jats:title><jats:p>The <jats:italic>in silico</jats:italic> predictions described the <jats:italic>EYA4</jats:italic> variant as likely pathogenic and the <jats:italic>EMD</jats:italic> variant as a variant of uncertain significance (VUS). Moreover, an ancestry analysis was performed using 46 Ancestry Informative Insertion/Deletion Markers (AIM-InDels), and the ancestral composition of subject A was 46% African, 26.1% European, and 27.9% American Indian ancestry, whereas the ancestral composition of subject B was 41.3% African, 38.2% European, and 20.5% American Indian ancestry. The present case report describes two Ecuadorian siblings with a mainly African ancestral component, muscular dystrophy, and deafness phenotypes. Moreover, using next-generation sequencing (NGS), a mutation in the <jats:italic>EMD</jats:italic> and a novel mutation in <jats:italic>EYA4</jats:italic> genes possibly associated with the subjects' phenotype were identified and discussed.</jats:p></jats:sec>Scopus© Citations 3 - 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