Papers by Gabriela García
Medicina-buenos Aires, 2019
Frontiers in Cellular and Infection Microbiology, 2022
Trypanosoma cruzi cruzipain (Cz) bears a C-terminal domain (C-T) that contains sulfated epitopes ... more Trypanosoma cruzi cruzipain (Cz) bears a C-terminal domain (C-T) that contains sulfated epitopes “sulfotopes” (GlcNAc6S) on its unique N-glycosylation site. The effects of in vivo exposure to GlcNAc6S on heart tissue ultrastructure, immune responses, and along the outcome of infection by T. cruzi, were evaluated in a murine experimental model, BALB/c, using three independent strategies. First, mice were pre-exposed to C-T by immunization. C-T-immunized mice (C-TIM) showed IgG2a/IgG1 <1, induced the production of cytokines from Th2, Th17, and Th1 profiles with respect to those of dC-TIM, which only induced IL-10 respect to the control mice. Surprisingly, after sublethal challenge, both C-TIM and dC-TIM showed significantly higher parasitemia and mortality than the control group. Second, mice exposed to BSA-GlcNAc6S as immunogen (BSA-GlcNAc6SIM) showed: severe ultrastructural cardiac alterations while BSA-GlcNAcIM conserved the regular tissue architecture with slight myofibril chan...
Parasitology, 2020
Trypanosoma cruzi, the etiological agent of Chagas disease, releases factors, including antigens ... more Trypanosoma cruzi, the etiological agent of Chagas disease, releases factors, including antigens from the trans-sialidase (TS) superfamily, which modulate the host immune responses. Tc13 antigens belong to group IV of TSs and are characterized by C-terminal EPKSA repeats. Here, we studied the effect of the Tc13 antigen from the Tulahuén strain, Tc13Tul, on primary cultures of splenocytes from naïve BALB/c mice. Recombinant Tc13Tul increased the percentage of viable cells and induced B (CD19+) lymphocyte proliferation. Tc13Tul stimulation also induced secretion of non-specific IgM and interferon-gamma (IFN-. The same effects were induced by Tc13Tul on splenocytes from naïve C3H/HeJ mice. In vivo administration of Tc13Tul to naïve BALB/c mice increased non-specific IgG in sera. In addition, in vitro cultured splenocytes from Tc13Tul-inoculated mice secreted a higher basal level of non-specific IgM than controls and the in vitro Tc13Tul stimulation of these cells showed an enhanced effect on IgM and IFN-secretion. Our results indicate that Tc13Tul may participate in the early immunity in T. cruzi infection by favoring immune system evasion through B-cell activation and non-specific Ig secretion. In contrast, as IFN- is an important factor involved in T. cruzi resistance, this may be considered a Tc13Tul effect in favor to the host.
International Journal of Infectious Diseases, 2018
Antimicrobial agents and chemotherapy, May 8, 2016
Benznidazole (Bz), the drug used for treatment of Chagas' disease (caused by the protozoan Tr... more Benznidazole (Bz), the drug used for treatment of Chagas' disease (caused by the protozoan Trypanosoma cruzi), is activated by a parasitic NADH-dependent nitroreductase (NTR I). However, several studies have shown that other enzymes are involved. The aim of this study was to evaluate whether the aldo-keto reductase from T. cruzi (TcAKR), a NADPH-dependent oxido-reductase previously described by our group, uses Bz as substrate. We demonstrated that both recombinant and native TcAKR reduce Bz by using NADPH, but not NADH, as co-factor. TcAKR-overexpressing epimastigotes showed higher NADPH-dependent Bz reductase activity and a 50% inhibitory concentration (IC50) value for Bz 1.8-fold higher than controls, suggesting that TcAKR is involved in Bz detoxification instead of activation. To understand the role of TcAKR in Bz metabolism, we studied TcAKR expression and NADPH/NADH-dependent Bz reductase activities in two T. cruzi strains with differential susceptibility to Bz: CL and Nica...
PLOS Neglected Tropical Diseases, 2015
Background Chronic Chagas cardiomyopathy caused by Trypanosoma cruzi is the result of a pathologi... more Background Chronic Chagas cardiomyopathy caused by Trypanosoma cruzi is the result of a pathologic process starting during the acute phase of parasite infection. Among different factors, the specific recognition of glycan structures by glycan-binding proteins from the parasite or from the mammalian host cells may play a critical role in the evolution of the infection.
Scientific Reports, 2021
Chagas disease is a neglected tropical disease caused byTrypanosoma cruziparasite with an estimat... more Chagas disease is a neglected tropical disease caused byTrypanosoma cruziparasite with an estimated 70 million people at risk. Traditionally, parasite presence in triatomine vectors is detected through optical microscopy which can be low in sensitivity or molecular techniques which can be costly in endemic countries. The aim of this study was to evaluate the ability of a reagent-free technique, the Near Infrared Spectroscopy (NIRS) for rapid and non-invasive detection ofT. cruziinTriatoma infestansbody parts and in wet/dry excreta samples of the insect. NIRS was 100% accurate for predicting the presence ofT. cruziinfection Dm28c strain (TcI) in either the midgut or the rectum and models developed from either body part could predict infection in the other part. Models developed to predict infection in excreta samples were 100% accurate for predicting infection in both wet and dry samples. However, models developed using dry excreta could not predict infection in wet samples and vice ...
Revista Lebret, 2014
Para identificar características de las empresas que pueden resultar significativas para explicar... more Para identificar características de las empresas que pueden resultar significativas para explicar la política de revelación de información voluntaria sobre los activos intangibles incorporados en los componentes del capital intelectual, se ha realizado un estudio de tipo correlacional que apunta a analizar la relación entre ciertas características de las empresas cotizantes en el Mercado de Valores de Buenos Aires y un índice que recoge la información que voluntariamente revelan estas empresas sobre los componentes de dichos elementos intangibles. El análisis de regresión múltiple aplicado indica que son las empresas con altos niveles de endeudamiento las que parecen estar más predispuestas a brindar información adicional sobre los componentes del capital intelectual, en tanto que las más rentables parecen oponerse a este tipo de revelación.
Revista Observatório, 2016
RESUMEN El inicio de la vida universitaria es un periodo difícil de transitar para los estudiante... more RESUMEN El inicio de la vida universitaria es un periodo difícil de transitar para los estudiantes, tanto en los estudios presenciales como a distancia. No obstante, muchos logran el rendimiento académico esperado. El objetivo de este artículo reside en analizar las metas y motivaciones de un grupo de estudiantes que logró regularizar las asignaturas previstas por el plan de estudios de las carreras que estaban cursando. Participaron del estudio 85 estudiantes de carreras de Ciencias Económicas dictadas en modalidad presencial y 14 sujetos que cursaban en la modalidad virtual. Los datos fueron recogidos mediante la administración de un cuestionario de autoinforme. Los resultados muestran prevalencia de metas de aprendizaje entre los sujetos del grupo presencial en tanto que entre los estudiantes de distancia la meta más destacada es la de evitar el fracaso. La discusión destaca la dimensión contextual de la motivación, sugiriendo acciones capaces de promover la motivación por el apr...
Molecular microbiology, Jan 7, 2017
The improvement of Chagas disease treatment is focused not only on the development of new drugs b... more The improvement of Chagas disease treatment is focused not only on the development of new drugs but also in understanding mechanisms of action and resistance to drugs conventionally used. Thus, some strategies aim to detect specific changes in proteins between sensitive and resistant parasites and to evaluate the role played in these processes by functional genomics. In this work, we used a natural Trypanosoma cruzi population resistant to benznidazole, which has clones with different susceptibilities to this drug without alterations in the NTR I gene. Using 2DE-gel electrophoresis, the aldo-keto reductase and the alcohol dehydrogenase proteins were found up regulated in the natural resistant clone and therefore their possible role in the resistance to benznidazole and glyoxal was investigated. Both genes were overexpressed in a drug sensitive T. cruzi clone and the biological changes in response to these compounds were evaluated. The results showed that the overexpression of these ...
The Journal of Clinical Endocrinology & Metabolism, 2008
Context: Uterine leiomyomas are the most frequent benign tumors during reproductive age. Whether ... more Context: Uterine leiomyomas are the most frequent benign tumors during reproductive age. Whether intramural leiomyomas cause infertility and should be removed is controversial because no study has addressed the underlying mechanism of infertility. Objective: The objective of the study was to test the effect of intramural leiomyomas on endometrial function by comparing gene during the window of implantation and implantation in an oocyte donation program, in which the quality of the embryos replaced is similar and the endocrine environment of the endometrium is standardized by exogenous steroids. Design: Human endometria of women with single intramural leiomyomas (group A, Ͻ5 cm and group B, Ն5 cm) and controls (group C) were collected on day LHϩ7 and processed for histology and gene expression analysis, using different methods and validated by quantitative RT-PCR. To compare in vitro fertilization outcome, a total of 1035 cases from our oocyte donation database were included, comprising patients with one fibroid less than 5 cm (A1, n ϭ 532); two leiomyomas less than 5 cm (A2, n ϭ 128); three or more leiomyomas less than 5 cm (A3, n ϭ 125); one fibroid 5 cm or greater (B, n ϭ 22); and two control groups: C1 (n ϭ 93), women with previous myomectomy; and C2 (n ϭ 135), women without uterine pathology treated on the same dates as C1. Results: There was a strong positive and negative correlation in the expression profile of 69 genes according to the leiomyomas's size, but only three of the 25 genes related to the window of implantation were dysregulated. Term pregnancy rates after oocyte donation were 36.9, 34.1, 39.0, 36.4, 39.2, and 42.6% (P ϭ 0.769) among the established groups. Similarly, no correlation between implantation and miscarriage with leiomyoma number and size was found. Conclusions: This study provides evidence that intramural leiomyomas not affecting the endometrial cavity alters the expression pattern of some endometrial genes, but the genes involved in implantation are not affected. This is confirmed by leiomyomas having no effect on oocyte donation outcome when the size and number of leiomyomas are analyzed.
Human Reproduction, 2007
BACKGROUND: Ovarian hyperstimulation syndrome (OHSS) is a result of ovarian overexpression of vas... more BACKGROUND: Ovarian hyperstimulation syndrome (OHSS) is a result of ovarian overexpression of vascular endothelial growth factor (VEGF) and its receptor 2 (VEGFR2). VEGF/VEGFR2 binding disrupts cellular junctions and increases vascular permeability (VP), a characteristic of OHSS, but enhances angiogenesis, which is a fundamental step in implantation. In animals, the dopamine agonist Cabergoline (Cb2) prevents VP without affecting angiogenesis. In humans, Cb2 averts OHSS, but a possible detrimental effect on angiogenesis and implantation has not been explored. A pilot study was designed to analyze whether or not Cb2 administration, as a procedure for preventing OHSS, affects the outcome of assisted reproduction treatment (ART). METHODS: A retrospective study with endpoints of implantation and ongoing/term pregnancy rates. Women (n 5 35) at risk of OHSS (20-30 follicles developed and >20 oocytes collected) took a daily oral dose of 0.5 mg Cb2 for 8 days, beginning on the day of hCG. They were matched with controls treated during the same period and who were similar with respect to age, number and quality of the embryos replaced, embryonic stage at transfer and sperm quality. RESULTS: No difference was detected between the groups in fertilization, implantation or pregnancy rates. A total of 14 ongoing (beyond 32 weeks) or full term pregnancies were registered in each group. No major problem was detected during pregnancy or after delivery in any of these babies. CONCLUSIONS: Administration of Cb2 in order to prevent OHSS is safe and does not appear to affect ART outcome.
Fertility and Sterility, 2008
In this first comparison of LBR between Indian and Caucasian women after BT, we found lower impla... more In this first comparison of LBR between Indian and Caucasian women after BT, we found lower implantation and LB rates in Indians. The cause for this difference remains unclear since the groups have similar response to stimulation and comparable embryo quality. The majority of our Indian patients were not born in the U.S. Studies are needed to evaluate ethnic differences in endometrial receptivity and environmental effects on fertility.
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Papers by Gabriela García