Papers by Nayali A. López Balderas
Clinical reviews & cases, Jun 30, 2023
Introduction: Minimal hepatic encephalopathy (MHE) is a neuropsychiatric complication in the pati... more Introduction: Minimal hepatic encephalopathy (MHE) is a neuropsychiatric complication in the patient with hepatic insufficiency, portal hypertension and/or portosystemic shunt, where there is cognitive damage, which includes alterations in attention, integrative function, delay in information processing, among others in the absence of manifest hepatic encephalopathy. Objective: To determine the prevalence of MHE by measuring cognitive damage in patients with hepatic cirrhosis through the PHES battery. Methodology: An observational, prospective, cross-sectional, and analytical study was carried out in patients with liver cirrhosis diagnosis, who came to the outpatient clinic of the gastroenterology department at the UMAE HE No. 14 Adolfo Ruiz Cortines National Medical Center. Patients with cirrhosis and no history of psychiatric illness or manifest encephalopathy were included, with previous authorization of informed consent and the research committee from the UV Medical School. The PHES battery was used as standardized test. Results: The sample size was calculated to be 66 patients. The PHES battery was performed in 34 of them, of which 35% (12) were diagnosed with minimal hepatic encephalopathy, 50% (6) women. The average age was 59 ± 10 years, minimum range 39, maximum range 80 (95% CI). Conclusion: The prevalence of minimal hepatic encephalopathy in 12 (35%), at UMAE HE No.14. The number and symbols test (DST) had a significant correlation regarding years of study, gender and age variables.
Revista Biomédica
Introducción: El virus de la inmunodeficiencia humana (VIH) infecta y destruye células CD4+ del s... more Introducción: El virus de la inmunodeficiencia humana (VIH) infecta y destruye células CD4+ del sistema inmunitario conduciendo gradualmente a una inmunodeficiencia. Las parasitosis oportunistas gastrointestinales son causa frecuente de morbilidad y mortalidad en pacientes VIH+. Objetivo: Determinar la prevalencia de los parásitos oportunistas Cyclospora cayetanensis, Cryptosporidium spp. y Cystoisospora belli en pacientes con VIH en el municipio de Veracruz. México. Material y métodos: Se recolectaron 230 muestras no seriadas de heces de pacientes con VIH. Los extendidos fueron análizados por método directo y tinción de Ziehl-Neelsen modificada. Resultados: Se encontró una prevalencia de parasitosis del 92.17%, en el 85.22% se identificó a Cryptosporidium spp. y Cyclospora cayetanensis, como mono-parasitismo o en asociación entre ellos, y con otros parásitos no oportunistas. Cryptosporidium spp. fue el parásito de mayor prevalencia (72.60%), seguido de C. cayetanensis (57.78%), End...
Transfusion Medicine, 2016
Annals of Human Biology, Apr 5, 2022
BackgroundMexican population databases for autosomal STRs are scarce, and no previous studies hav... more BackgroundMexican population databases for autosomal STRs are scarce, and no previous studies have been performed with the Qiagen Investigator 24plex GO! Aim: To analyse the frequency of 21 autosomal short tandem repeat (STR) loci and forensic parameters in individuals from Veracruz state, Mexico. Subjects and methods: A total of 234 unrelated individuals were analysed with the Investigator 24plex GO! Kit, which includes the following autosomal STRs: TH01, D3S1358, vWA, D21S11, TPOX, D1S1656, D12S391, SE33, D10S1248, D22S1045, D19S433, D8S133879, D2S1338, D2S441, D18S51, FGA, D16S539, CSF1PO, D13S317, D5S818, and D7S820. Allele frequencies, forensic parameters, and relationships with neighbouring Mexican populations were estimated. Results: The STRs analysed were in Hardy-Weinberg Equilibrium (HWE). The combined matching probability and combined PE were 1.5266 E-24 and 0.999999988711, respectively. The D18S51 and SE33 loci presented the highest Ho (0.8974 and 0.8932) and PE (0.7902 and 0.7815), respectively. The highest PIC (0.9337) and PD (0.9894) values corresponded to SE33. Conversely, D22S1045 had the lowest PIC and PE (0.5533 y 0.3546, respectively). A population cluster among southern Mexican populations, which included non-differentiation between Guerrero and Veracruz states was detected. Conclusion: The forensic efficacy of the 21 STRs analysed by the Investigator 24plex GO! Kit was evaluated in the Veracruz state. Moreover, new population clusters that have not been yet been described and are related to geographic regions were identified, and these are in agreement with previously reported ancestral differences.
Ciencia e Innovación en Salud, 2021
Introducción: La Diabetes Mellitus se caracteriza por elevación de glucosa en sangre. En el año... more Introducción: La Diabetes Mellitus se caracteriza por elevación de glucosa en sangre. En el año 2014 vivían 422 millones de personas con diabetes (8.5%) a nivel mundial. En México, en el 2018 vivían aproximadamente 8.6 millones de personas con diabetes (10.3%) y el 70% de la población adulta presentaba sobrepeso u obesidad. Se ha buscado validar herramientas de bajo costo para ampliar la atención médica de población en riesgo de padecer diabetes. El test de FINDRISC es un instrumento utilizado a nivel mundial para evaluar el riesgo de desarrollar diabetes tipo 2. El objetivo de este estudio fue analizar la correlación entre el puntaje del FINDRISC y el valor de la hemoglobina glucosilada en docentes del área de ciencias de la salud en la Universidad Veracruzana. Métodos: Estudio observacional y transversal. Se aplicó el cuestionario FINDRISC a 92 docentes procedentes de Facultades de Ciencias de la Salud, en los que además se determinó la hemoglobina glucosilada. Resultados: El po...
Transfusion Medicine, 2020
Objectives: To identify blood donors with occult hepatitis B infections (OBIs), determine the pre... more Objectives: To identify blood donors with occult hepatitis B infections (OBIs), determine the prevalence of antibody to hepatitis B core antigen (anti-HBc) positivity and estimate the impact of anti-HBc screening on donor deferral at CETS-Veracruz (Mexico). Background: Hepatitis B virus infection is a major concern in transfusion medicine. Mexican regulations only mandate screening for hepatitis B surface antigen (HBsAg), and there are no requirements regarding testing for anti-HBc or use of a nucleic acid test (NAT). There is, therefore, limited information about the prevalence of anti-HBc positivity and occult hepatitis B among blood donors in Mexico. Methods: This retrospective study examined individuals who donated blood to CETS-Veracruz from June 2014 to June 2017. All donors were serologically examined according to Mexican health regulations, and the prevalence of anti-HBc positivity was determined. A NAT was used to identify individuals with OBIs. Results: We analysed the data of 28 016 blood donors. Over 4 years, the average prevalence of anti-HBc positivity was 1.05%. The risk factors for anti-HBc positivity were low education and age over 50 years. There were nine donors with OBIs. Conclusion: The presence of donors with OBIs in CETS-Veracruz and other Mexican blood banks highlights the need to mandate the implementation of anti-HBc screening in Mexico.
Transfusion and Apheresis Science, 2018
Syphilis and HIV infections continue to threaten the safety of blood banks in countries where alt... more Syphilis and HIV infections continue to threaten the safety of blood banks in countries where altruistic donations are rare. The aim of this study of blood donors to the Centro Estatal de la Transfusion Sanguínea de Veracruz (Mexico) was to determine changes in the prevalence of syphilis and HIV, and to identify factors associated with these infections. A total of 109,054 blood donors were retrospectively analyzed from 2007 to 2014. Serological screening of blood units was performed, and demographic data were collected from clinical records to identify risk factors. The prevalence of Treponema pallidum was 1.4% and that of confirmed HIV was 0.11%. The main risk factors for HIV positivity were age of 18 to 24 years-old, being unmarried, and being an employee or student. The main risk factors for syphilis positivity were being a widow or divorced, being over 35 years-old, having a low level of education, and being a driver, fisherman, or trade worker. There were high prevalences for both infections in southeast Veracruz, where females and males had equal probabilities of each infection. Strengthening of education programs on sexually transmitted diseases for young people may help to prevent new and congenital infections.
Transfusion, 2014
BACKGROUND: Trypanosoma cruzi is the causal agent of Chagas disease. Of the Mexican states, Verac... more BACKGROUND: Trypanosoma cruzi is the causal agent of Chagas disease. Of the Mexican states, Veracruz is among the most affected by this sickness. However, the actual epidemiologic situation of this disease is not well understood. This study sought to determine the prevalence and risk factors for Chagas disease among Veracruzan blood donors. STUDY DESIGN AND METHODS: Blood donors from Centro Estatal de la Transfusion Sanguinea de Veracruz were included. Blood units were serologically scrutinized for T. cruzi antibodies using enzyme-linked immunosorbent assays. To identify risk factors, demographic data were collected from the medical records of positive donors and a representative sample of healthy donors. RESULTS: A total of 87,232 donations were analyzed, and the mean prevalence of T. cruzi was found to be 0.5%. The identified risk factors were living as a couple and in a rural area, having a low level of education, being a farmer, dwelling in a house with earthen or wooden walls and a tile or thatch roof, living with domestic animals, recognition of or exposure to triatomine bugs, and residing in the Huasteca region. An increase of rural-living donors infected with T. cruzi was observed in the past 3 years of the study period. CONCLUSION: The prevalence to Chagas disease has not decreased in the past decade and the disease appears to be spreading in rural areas of Veracruz. This increases the risk of T. cruzi transfusiontransmitted infection, not only in Veracruz and Mexico, but also in other nonendemic countries that receive immigrants from Veracruz State.
The Scientific World JOURNAL, 2009
Interactionin vitrobetween cells infected with human immunodeficiency virus (HIV) and surrounding... more Interactionin vitrobetween cells infected with human immunodeficiency virus (HIV) and surrounding, uninfected, target cells often leads to cell fusion and the formation of multinucleated cells, called syncytia. The presence in HIV-infected individuals of virus strains able to induce syncytia in cultures of T cells is associated with disease progression and AIDS. Even in the asymptomatic stage of infection, multinucleated cells have been observed in different organs, indicating that fused cells may be generated and remain viable in the tissues of patients. We used lymphocytic cells transfected for the expression of the HIV-envelope (Env) glycoproteins to develop a method for the direct quantification of fusion events by flow cytometry (Huerta et al., 2006,J. Virol. Methods138, 17–23; López-Balderas et al., 2007,Virus Res.123, 138–146). The method involves the staining of fusion partners with lipophilic probes and the use of fluorescence resonance energy transfer (FRET) to distinguish...
Virus Research, 2007
Syncytia formation in HIV infections is driven by the virus fusion-active molecules (Env) interac... more Syncytia formation in HIV infections is driven by the virus fusion-active molecules (Env) interacting with membrane components of hosts cells. HIV-syncytia are usually interpreted as pathogenic entities and although they may potentially vary in size, numbers and types of constituent cells, little is known about the extent and significance of their diversity. Here, we describe numerically the cell population dynamics and the diversity of syncytia produced in the in vitro cell-fusion between two Jurkat T cell lines, one CD4 + and the other Env +. Cell-fusion partners were differentially stained with the lipophilic DiI and DiO, or with the cytoplasmic CMFDA and CMTMR tracers and syncytia showing double fluorescence were counted in a flow cytometer. The total number of syncytia formed, their size, cellular complexity and ratio of CD4 + /Env + cells recruited, varied significantly in relation with time of reaction and initial proportions of fusion partners. The considerable structural diversity of syncytia formed, in so limited an in vitro cell fusion reaction, suggests that a greater heterogeneity may be formed in the natural course of disease. Identification of the main determinants of syncytia diversity allows for a detailed study of the relation between the syncytia structure and function.
Journal of Virological Methods, 2006
Expression of fusion proteins in the plasma membrane enables cells to bind and fuse with surround... more Expression of fusion proteins in the plasma membrane enables cells to bind and fuse with surrounding cells to form syncytia. Cell fusion can have important functional outcomes for the interacting cells, as syncytia formation does in AIDS pathogenesis. Studies on cell fusion would be facilitated by a quantitative method able to discriminate between cellular aggregates and bona fide fused cells in a cell population. Flow cytometry with fluorescence resonance energy transfer is applied here for analyzing fusion of HIV-1 envelope-expressing cells with CD4 + Jurkat cells. Fusion partners were labeled with the vital lipophilic fluorescent probes DiO (green) and DiI (red) and FRET is manifested by an enhancement of the DiI red fluorescence intensity in double fluorescent cells, thus allowing discrimination between fused and aggregated cells. The inhibitory effect of anti-CD4 monoclonal antibodies and the inhibitory peptide T-20 upon cell fusion were readily quantified by this technique. This method allows the distinction of fused and aggregated cells even when they are at low frequencies.
Archives of Virology, 2010
In human HIV infection, multinucleated cells (syncytia) are formed by fusion of HIV-infected cell... more In human HIV infection, multinucleated cells (syncytia) are formed by fusion of HIV-infected cells with CD4 ? cells. In order to examine possible functional implications of syncytia formation for the immune response, the expression of important surface molecules by T-cell syncytia and surrounding cells that remain unfused (bystander cells) was analyzed in cocultures of HIV-Envand CD4-expressing E6 Jurkat T cells. Fusion partners were differentially labeled with lipophilic probes, and syncytia and bystander cells were identified by flow cytometry. The cellular phenotype and response to activation stimulus after fusion were analyzed with antibodies coupled to third-party fluorochromes. Cocultured unfused E6 cells showed a marked decrease in CD4 expression, suggesting the selective recruitment of cells strongly expressing CD4 into syncytia. However, the incorporated CD4 was not detected in the syncytia, whereas the range of expression of CD28, ICAM-1, CXCR4 and CD3 was wider than that of unfused cells. Limited expression of CD4 in the bystander unfused population, as well as in the newly formed syncytia, would result in limitation of further viral entry and a failure to identify these cells, and it could partially contribute to functional impairment and a decrease in the number of CD4 ? T cells in AIDS. Most of the syncytia were viable and expressed CD25 and IL-2 in response to activation by phorbol myristate acetate (PMA) and ionomicyn. Thus, syncytia populations harboring widely heterogeneous levels of receptors would constitute a potential source of anomalous immune function. E. Rivera-Toledo and N. López-Balderas contributed equally to this work and are listed as co-first authors.
The Journal of Infection in Developing Countries, 2015
Introduction: Hepatitis B and C are among the most important transfusion-transmitted infections a... more Introduction: Hepatitis B and C are among the most important transfusion-transmitted infections and sources of liver diseases worldwide. In Veracruz, Mexico, liver diseases are important causes of mortality, and the prevalence reports of these viruses are scarce. This study sought to determine the prevalence of these infections in blood donors, in order to increase the safety of blood products in this region. Methodology: A retrospective study was performed on blood donors who attended the Veracruz State Blood Transfusion Center from 2006 to 2010. All samples were screened for transfusion-transmitted infections. The prevalence rates of hepatitis B virus (HBV) and hepatitis C virus (HCV) were determined, and demographic data obtained from clinical records were used to evaluate risk factors. Results: A total of 56,377 donors were serologically screened; of them, 403 were seropositive for HCV (357 men and 46 women), and 61 were positive for HBsAg (52 men and 9 women). The overall preva...
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Papers by Nayali A. López Balderas