Papers by Lic.Fernanda Suarez
Investigative Ophthalmology & Visual Science, 2017
Methods in molecular biology, 2019
Enzymes exist in all biological systems to catalyze vital biochemical reactions. The reactivity o... more Enzymes exist in all biological systems to catalyze vital biochemical reactions. The reactivity of an enzyme and the extent of its influence on product formation can give insight to understanding the physiological changes that can take place. The enzyme HSD17B7, involved in the cholesterol biosynthesis pathway, may play a role in influencing underlying changes during transition of disease, specifically in eyes at normal state to eyes that have glaucoma. In this work, we present a method to test the enzymatic activity level of HSD17B7 between normal and glaucomatous optic nerves to assess whether enzymatic upregulation of cholesterol biosynthesis may play a role in glaucoma.
Methods in molecular biology, 2019
The separation and analysis of protein-lipid complexes has proven to be challenging due to the ha... more The separation and analysis of protein-lipid complexes has proven to be challenging due to the harsh conditions required by conventional methods of protein or lipid isolation, which disrupt the fine forces that govern the interactions between lipid head groups and protein side chains. The method described in this publication presents an alternative for the separation of protein-lipid complexes while maintaining the integrity of their interactions. The method exploits the specific electrophoretic forces that are unique to the geometry of the capillary system and allows purification of intact complexes and the systematic analysis of its constituents. This technique is specifically applied for the separation of native protein-lipid complexes found in the central nervous system.
Investigative Ophthalmology & Visual Science, 2015
International Journal of Molecular Sciences, 2021
Solar damage due to ultraviolet radiation (UVR) is implicated in the development of two prolifera... more Solar damage due to ultraviolet radiation (UVR) is implicated in the development of two proliferative lesions of the ocular surface: pterygium and pinguecula. Pterygium and pinguecula specimens were collected, along with adjacent healthy conjunctiva specimens. RNA was extracted and sequenced. Pairwise comparisons were made of differentially expressed genes (DEGs). Computational methods were used for analysis. Transcripts from 18,630 genes were identified. Comparison of two subgroups of pterygium specimens uncovered evidence of genomic instability associated with inflammation and the immune response; these changes were also observed in pinguecula, but to a lesser extent. Among the top DEGs were four genes encoding tumor suppressors that were downregulated in pterygium: C10orf90, RARRES1, DMBT1 and SCGB3A1; C10orf90 and RARRES1 were also downregulated in pinguecula. Ingenuity Pathway Analysis overwhelmingly linked DEGs to cancer for both lesions; however, both lesions are clearly stil...
Journal of Cellular Biochemistry, 2017
Journal of Cellular Biochemistry, 2017
ABSTRACTClimatic droplet keratopathy (CDK) is an acquired degenerative disease predominantly affe... more ABSTRACTClimatic droplet keratopathy (CDK) is an acquired degenerative disease predominantly affecting males over 40 years old. It results in progressive corneal opacities usually affecting both eyes. CDK is multifactorial and its etiology remains unknown. Our recent findings are consistent with CDK pathology being driven by environmental factors with oxidative stress playing an important role (e.g.,, contributing to lipid peroxidation) rather than climate factors. The changes in corneal lipid composition affected by environmental factors remain understudied. The purpose of this study was to systematically investigate phospholipids profile (phosphatidylcholine [PC] and phosphatidylserine [PS]) in corneas from CDK patients using tandem mass spectrometry. Samples from CDK areas and from non‐affected areas were obtained from patients diagnosed with CDK who underwent cataract surgery, were subjected to lipid extraction using a modified Bligh and Dyer method; protein concentrations were ...
Journal of Clinical & Experimental Ophthalmology, 2015
Objective: The purpose of our work was to study and compare the cornea and tear film of people an... more Objective: The purpose of our work was to study and compare the cornea and tear film of people and sheep inhabiting in a region of Argentinean Patagonia (PATG), and in a geographically and climatically different region in the Argentinean Pampa (CAPT). Methods: Using cross sectional study, corneal examinations were performed in people and Merino sheep inhabiting PATG and CAPT regions, respectively. All people completed a questionnaire related to work activity, diet, and the use of hats or sunglasses during their life. Eyes from all participants were examined with a portable handheld slitlamp biomicroscope (BM) to evaluate corneal appearance, epithelium integrity, and transparency. Later on, in a subgroup of participants we studied eyeblinking frequency (EBF), ocular surface staining (FS), breakup time (BUT), Schirmer Tear Test (STT), corneal structure using confocal laser scanning microscopy (CLSM) and light microscopy (LM), and concentrations of serum ascorbate (sAA). Results: BM studies revealed numerous cases of Climatic Droplets Keratopathy (CDK) only in people inhabiting the PATG region. CLSM studies confirmed typical punctiform deposits at the Bowman´s layer in CDK patients living in that region. CLSM images from sheep did not show any abnormalities at the Bowman´s layer but exhibited small hyper reflective dots at the epithelium only in animals pasturing in the PATG region. FS and EBF mean values were significant higher in sheep grazing in the PATG region (p <0.05). No differences were found in surface eye tests when people from both regions were analyzed. Low sAA levels were found only in CDK people living in PATG region. Conclusions: CDK is a multi-factorial disease not only associated to harsh climate. We provide data that low sAA levels can play a role in its genesis in Patagonia patients'... Sheep pasturing in this region with a high prevalence of CDK have high concentration of sAA and did not present any sub epithelial corneal abnormalities.
Archivos de la Sociedad Española de Oftalmología, 2015
Climatic droplets keratopathy (CDK) is closely associated with superficial corneal erosions and l... more Climatic droplets keratopathy (CDK) is closely associated with superficial corneal erosions and lack of protective mechanisms against the harmful effects of ultraviolet radiation (UVR) during a prolonged period of time. One of the difficulties in studying the pathogenic mechanisms involved in this human disease is the lack of an experimental animal model. In this paper, a study is conducted on the effects of 4 types of lasers at various powers and time conditions on the normal guinea pig corneas in order to select only one laser condition that reversibly injures the epithelium and superficial stroma, without leaving scarring. Damage was induced in the cornea of Guinea pigs using different powers and exposure times of 4 types of laser: argon, CO2, diode and Nd-Yag, and any injuries were evaluated by biomicroscopy (BM) and optical microscopy. Corneas from other normal animals were exposed to argon laser (350 mW, 0.3s, 50μm of diameter), and the induced alterations were studied at different times using BM, optical coherence tomography (OCT) and transmission electron microscopy (TEM). Only argon laser at 350 mW, 0.3s, 50μm of diameter produced epithelium and superficial stroma lesions. Some leukomas were observed by BM, and they disappeared by day 15. Corneal thickness measured by OCT decreased in the eyes treated with argon laser during the first week. Using TEM, different ultra structural alterations in corneal epithelium and stroma were observed during the early days, which disappeared by day 15. It was possible to develop reproducible corneal epithelium and anterior stroma injuries using Argon laser at 350 mW, 0.3s, 50μm of diameter. In vivo and in vitro studies showed that injured corneas with these laser conditions did not leave irreversible microscopic or ultra structural alterations. This protocol of corneal erosion combined with exposure to UVR and partial deficiency of ascorbate in the diets of the animals for an extended period of time has been used in order to try to develop an experimental model of CDK.
Handbook of Nutrition, Diet and the Eye, 2014
The cornea plays important roles in the eye since it not only maintains the ocular pressure and p... more The cornea plays important roles in the eye since it not only maintains the ocular pressure and protects against different aggressions and forces but constitutes the primary lens in many animals’ eyes as well. In order to fulfill these extremely crucial functions, the cornea requires sophisticated structures called the epithelium, Bowman’s membrane, the stroma, Descement’s layer, and the endothelium. The complexity of this tissue is such that despite many efforts, it has not been possible to obtain clinically viable corneas in the laboratory yet. Vitamin C or L-ascorbic acid is an essential vitamin and a water-soluble important nutrient many animals chemically synthesize from glucose by means of enzymatic reactions, with L-gulono-γ-lactone oxidase being the last step. Among the multiple roles played by this vitamin, its primary functions are to act as a cofactor for reactions requiring reduced iron or copper metalloenzyme and as a protective antioxidant that operates in the aqueous phases, both intra- and extracellularly. Ocular tissues, particularly the cornea, concentrate vitamin C, which might suggest that the cornea’s different structures need this vitamin to fulfill their roles. In this work, we present scientific evidence of the critical roles that ascorbic acid performs in maintaining the functions and ultrastructures of the corneal epithelium, the stroma, and the endothelium.
PLoS ONE, 2013
To determine whether the incidence of and susceptibility to climatic droplet keratopathy (CDK), a... more To determine whether the incidence of and susceptibility to climatic droplet keratopathy (CDK), an acquired, often bilateral degenerative corneal disease, is influenced by the genetic background of the individuals who exhibit the disorder. Methods To determine whether the disease expression was influenced by the genetic ancestry of CDK cases in native Mapuche of the northwest area of Patagonia in Argentina, we examined mitochondrial DNA and Ychromosome variation in 53 unrelated individuals. Twenty-nine of them were part of the CDK (patient) population, while 24 were part of the control group. The analysis revealed the maternal and paternal lineages that were present in the two study groups. Results This analysis demonstrated that nearly all persons had a Native American mtDNA background, whereas 50% of the CDK group and 37% of the control group had Native American paternal ancestry, respectively. There was no significant difference in the frequencies of mtDNA haplogroups between the CDK patient and control groups. Although the Y-chromosome data revealed differences in specific haplogroup frequencies between these two groups, there was no statistically significant relationship between individual paternal genetic backgrounds and the incidence or stage of disease. Conclusions These results indicate a lack of correlation between genetic ancestry as represented by haploid genetic systems and the incidence of CDK in Mapuche populations. In addition, the mtDNA appears to play less of a role in CDK expression than for other complex diseases linked to bioenergetic processes. However, further analysis of the mtDNA genome sequence and other genes involved in corneal function may reveal the more precise role that mitochondria play in the expression of CDK.
Revista Colombiana De Materiales, May 15, 2014
En la actualidad una de las aplicaciones médicas más innovadoras del quitosano (CHT), es la de ap... more En la actualidad una de las aplicaciones médicas más innovadoras del quitosano (CHT), es la de apósitos que estimulen la regeneración de la piel. La naturaleza adhesiva de este biopolímero, junto con su carácter bactericida, antifúngico y su permeabilidad al oxígeno son propiedades muy importantes asociadas con el tratamiento de quemaduras. Sin embargo, la baja resistencia mecánica y la variación de algunas características, bajo condiciones húmedas limitan su uso en la ingeniería de tejidos. Por lo anteriormente planteado, el propósito de esta investigación es mejorar las propiedades mecánicas de películas de CHT obtenidas por el método de evaporación lenta, al plastificarlas con glicerina, y evaluar su comportamiento a una humedad relativa de 70 ±5 % usada para el acondicionamiento del material.
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Papers by Lic.Fernanda Suarez