Omar Esteban Valencia

Dr. Omar Esteban Valencia

orcid

Research Focus & Metrics

Academic Career Length

5Years (2022-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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25 October 2022 in Pathogens
Verified
Journal Article
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Carlos Alberto Castro-FuentesCarlos Alberto Castro-Fuentes
Carlos Alberto Castro-Fuentes
MRMaría del Rocío Reyes-Montes
María del Rocío Reyes-Montes
MFMaría Guadalupe Frías-De-León
María Guadalupe Frías-De-León
OVOmar Esteban Valencia
Omar Esteban Valencia
GAGustavo Acosta-Altamirano
Gustavo Acosta-Altamirano
Esperanza Duarte-EscalanteEsperanza Duarte-Escalante
Esperanza Duarte-Escalante
COVID-19-associated pulmonary aspergillosis (CAPA) has had a high incidence. In addition, it has been associated with prolonged hospital stays, as well as several predisposing risk factors, such as fungal factors (nosocomial organism, the size of the conidia, and the ability of the Aspergillus spp. of colonizing the respiratory tract), environmental factors (remodeling in hospitals, use of air conditioning and negative pressure in intensive care units), comorbidities, and immunosuppressive therapies. In addition to these factors, SARS-CoV-2 per se is associated with significant dysfunction of the patient’s immune system, involving both innate and acquired immunity, with reduced CD4+ and CD8+ T cell counts and cytokine storm. Therefore, this review aims to identify the factors influencing the fungus so that coinfection with SARS-CoV-2 can occur. In addition, we analyze the predisposing factors in the fungus, host, and the immune response alteration due to the pathogenicity of SARS-CoV-2 that causes the development of CAPA.

26 July 2024 in Pathogens
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Journal Article
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RARoberto Renan Albavera-Gutierrez
Roberto Renan Albavera-Gutierrez
MEManuel A. Espinosa-Ramos
Manuel A. Espinosa-Ramos
ERErnesto Rebolledo-Bello
Ernesto Rebolledo-Bello
FPFrancisco J. Paredes-Herrera
Francisco J. Paredes-Herrera
DCDaniel Carballo-Lucero
Daniel Carballo-Lucero
Carlos Alberto Castro-FuentesCarlos Alberto Castro-Fuentes
Carlos Alberto Castro-Fuentes
Using orthopedic devices or prosthetic joints to treat various conditions is expected in a Traumatology and Orthopedics Unit. Recently, the materials used to build these different devices have evolved; however, pathogens can still infect these materials. Additionally, the immune system has limitations when defending against these pathogens, which results in bacterial infections like Staphylococcus aureus, Methicillin-susceptible Staphylococcus aureus (MSSA) and Methicillin-resistant Staphylococcus aureus (MRSA). A total of 276 patients who attended the Traumatology and Orthopedics Unit of our hospital from 1 June 2018 to 1 June 2019, were included in the present study. Our study analyzed the incidence of S. aureus and other bacterial pathogens in the surgical sites of patients with orthopedic implants, as well as the most used types of implants and implant materials. The specimens obtained from the surgical sites of the patients were cultured in anaerobic and aerobic media for subsequent identification using their phenotypic characteristics. Subsequently, antibiotic susceptibility tests were performed to establish the appropriate treatment. The primary pathogens identified were Staphylococcus aureus (26.4%), followed by Escherichia coli (21.0%) and Staphylococcus epidermidis (15.8%). The most commonly used implants were plates (41.7%), followed by endomedullary nails (20%), Kirschner wires (14.1%), and fixators (10.1%). As for the anatomical regions of the implants, the most frequent sites were the legs, followed by the thighs, wrists, and ankles. The pathogens were more susceptible to ciprofloxacin (95%), clindamycin (89%), and cefotaxime (86%). S. aureus is the primary infectious agent in our hospital, with an incidence of 26.4% after the placement of orthopedic implants. Although its incidence was lower compared to other tertiary hospitals, it is necessary to improve aseptic techniques in such a way as to reduce the incidence of this pathogen further.

13 March 2022 in Journal of Fungi
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Journal Article
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OVOmar Esteban Valencia
Omar Esteban Valencia
Carlos Alberto Castro-FuentesCarlos Alberto Castro-Fuentes
Carlos Alberto Castro-Fuentes
Esperanza Duarte-EscalanteEsperanza Duarte-Escalante
Esperanza Duarte-Escalante
MFMaría Guadalupe Frías-De-León
María Guadalupe Frías-De-León
MRMaría del Rocío Reyes-Montes
María del Rocío Reyes-Montes
The objective of this work was to use the random amplification of the polymorphic DNA–polymerase chain reaction (RAPD-PCR) technique to select polymorphic patterns through qualitative and quantitative analyses to differentiate the species A. flavus, A. fumigatus, A. niger and A. tubingensis. Twenty-seven Aspergillus isolates from different species were typified using phenotypic (macro- and micromorphology) and genotypic (partial BenA gene sequencing) methods. Thirty-four primers were used to obtain polymorphic patterns, and with these a qualitative analysis was performed to select the primers that presented species-specific patterns to distinguish each species. For the quantitative selection, a database was built from the polymorphic patterns and used for the construction of logistic regression models; later, the model that presented the highest value of sensitivity against specificity was evaluated through ROC curves. The qualitative selection showed that the primers OPA-19, P54, 1253 and OPA-02 could differentiate the species. A quantitative analysis was carried out through logistic regression, whereby a species-specific correlation of sensitivity and specificity greater than 90% was obtained for the primers: OPC-06 with a 96.32% match to A. flavus; OPF-01 with a 100% match to A. fumigatus; OPG-13 with a 98.01% match to A. tubingensis; and OPF-07 with a 99.71% match to A. niger. The primer OPF-01 discriminated the four species as well as closely related species. The quantitative methods using the selected primers allowed discrimination between species and showed their usefulness for genotyping some of the species of medical relevance belonging to the genus Aspergillus.

Verified
Journal Article
Open access
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RMRebeca Martínez-Quezada
Rebeca Martínez-Quezada
CRCarlos Emilio Miguel Rodríguez
Carlos Emilio Miguel Rodríguez
TLTito Ramírez LOZADA
Tito Ramírez LOZADA
OVOmar Esteban Valencia
Omar Esteban Valencia
GAGustavo Acosta-Altamirano
Gustavo Acosta-Altamirano
The protection of the neonate against pathogens depends largely on the antibodies transferred placentally from the mother; for this reason, maternal vaccination against emerging viruses, such as SARS-CoV-2, is of vital importance. Knowing some of the immunogenic factors that could alter the placental transfer of antibodies could aid in understanding the immune response and neonatal protection after maternal vaccination. In this study, we analyzed the efficiency of the placental transfer of binding and neutralizing antibodies, as well as some factors that could alter the passive immune response, such as the trimester of gestation at the time of immunization, the number of doses received by the mother and the type of vaccine. Binding IgG antibodies were detected by ELISA, and the detection of neutralizing antibodies was carried out using flow cytometry. Our results show efficient transfer rates (>1), which are higher when maternal vaccination occurs during the third trimester of gestation. Antibodies are detectable in mothers and their neonates after 12 months of maternal immunization, suggesting than the vaccination against COVID-19 before and during pregnancy in the Mexican population induces a lasting neutralizing response in mothers and their newborns.

31 July 2024 in Vaccines
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RMRebeca Martínez-Quezada
Rebeca Martínez-Quezada
OVOmar Esteban Valencia
Omar Esteban Valencia
TLTito Ramírez LOZADA
Tito Ramírez LOZADA
CRCarlos Emilio Miguel Rodríguez
Carlos Emilio Miguel Rodríguez
JFJuan Carlos Fernández-Hernández
Juan Carlos Fernández-Hernández
GAGustavo Acosta-Altamirano
Gustavo Acosta-Altamirano
In the present study, we evaluated the influence of maternal and neonatal factors on the efficiency of the placental transfer of neutralizing antibodies against SARS-CoV-2. Vaccination during pregnancy provides fetal and neonatal protection through the passive transplacental transfer of maternal neutralizing antibodies. To date, little information is available regarding the factors that affect the transfer of antibodies against SARS-CoV-2. A retrospective, cross-sectional, observational, and analytical study was carried out. It was found that several biological factors could be altering transplacental passive immunity after vaccination against COVID-19. In our study population, type 2 diabetes mellitus and chronic hypertension tended to decrease efficiency, while data from women with pre-eclampsia showed better indices compared to those from women with healthy pregnancies. Neonates born prematurely showed lower transfer rates when compared to healthy neonates. The premature rupture of membranes significantly decreased antibody transfer. Taken together, the data suggest that vaccination against COVID-19 during pregnancy is effective even under certain unfavorable clinical conditions for the mother, fetus, and neonate. It is important to create and disseminate immunization strategies in vulnerable populations to reduce maternal and perinatal morbidity and mortality associated with infections preventable by vaccination.

1 January 2024 in Case Reports in Psychiatry
Verified
Journal Article
Open access
JEJonatan Escobar-Herrera
Jonatan Escobar-Herrera
GLGibran Raymundo León-Gallegos
Gibran Raymundo León-Gallegos
OVOmar Esteban Valencia
Omar Esteban Valencia
RGRafael García-Rascon
Rafael García-Rascon
NGNicolás Santiago González
Nicolás Santiago González
Delusional parasitosis is a psychotic disorder where the patient has the delusion of being infested with some insect or parasite. In contrast, shared paranoid disorder or folie à deux is described when the same delusions affect two or more closely related people. It is common for these two situations to cause comorbidity in the family unit. This case report concerns a couple married for 37 years. The husband described that 2 years ago, he began with a tingling sensation throughout his body, related to the presence of parasites coming out from all his body orifices, with no evidence of self‐harm. Likewise, the wife reported symptoms of formication and the feeling that there were invisible animals, as mentioned by her husband, and that she felt the parasites running throughout her body. The husband was diagnosed with endoparasitic delusional parasitosis, which caused folie à deux in his wife due to ectoparasitic parasitosis. The patient’s treatment included sertraline and risperidone in oral dosage lasting 3 months reducing delirium, later biperidene was prescribed due to main treatment’s side effects such as akathisia and sialorrhea, however the patient could not take the medication due to economic reasons. The wife was asked to sleep in a separate room, and she reported that the sensory hallucinations disappeared as soon as she slept in a different room. We conclude that the pharmacological approach, the intervention in the family life, and the gradual reintegration of marital habits once the patient improves are crucial in the therapy of delusional disorder.