Papers by Ricardo Sánchez
Complementary and alternative treatments play an ever increasing role in cancer therapy, to the e... more Complementary and alternative treatments play an ever increasing role in cancer therapy, to the extent that the most important medi- cal centres have decided to include them in the list of services offered to their patients. This article reviews the global panorama on the subject, and it concludes that it is necessary to evaluate the possible beneficial effects of these
Mobile Computing and Communications Review, 1998
This paper reports on the initial implementation of an experimental wireless ATM network architec... more This paper reports on the initial implementation of an experimental wireless ATM network architecture called RDRN (Rapidly Deployable Radio Network). The RDRN architecture consists of two types of transportable nodes, remote nodes (RNs) and edge nodes (ENs), which utilize GPS-derived location information to rapidly configure themselves into a high capacity wireless network operating at 1--10 Mb/s over distances as far
Translationally inactive histone mRNA is stored in frog oocytes, and translation is activated at ... more Translationally inactive histone mRNA is stored in frog oocytes, and translation is activated at oocyte maturation. The replication-dependent histone mRNAs are not polyadenylated and end in a conserved stem- loop structure. There are two proteins (SLBPs) which bind the 3* end of histone mRNA in frog oocytes. SLBP1 participates in pre-mRNA processing in the nucleus. SLBP2 is oocyte specific, is
Objetivos Establecer tipologías de los suicidas en relación con un grupo de variables descritas c... more Objetivos Establecer tipologías de los suicidas en relación con un grupo de variables descritas como factores de riesgo y describir el comportamiento de dichas tipologías a lo largo del tiempo. Métodos Estudio observacional-analítico con base en registros de necropsia de los casos de suicidio en Bogotá en 1985Bogotá en , 1990Bogotá en , 1995Bogotá en y 2000. Para determinar las tipologías se utilizó el método de análisis multivariado de correspondencias múltiples. Resultados Se detectaron 171 casos de suicidio en 1985, 222 casos en 1990, 273 en 1995 y 329 en el año 2000. Se evidenció que factores como la comorbilidad física o mental, el uso de sustancias psicoactivas, el acceso a métodos letales, y el poco uso de armas de fuego por parte de las mujeres, son factores constantes en los años estudiados. A su vez, se presentaron cambios en algunas tipologías que se relacionaron con la presencia de adicciones en mujeres y el VIH-SIDA. Conclusiones Aunque existen tipologías de suicidas relativamente constantes a lo largo del período de 15 años, la aparición de cambios en los perfiles epidemiológicos y en los estilos de vida generan modificaciones de tales tipologías. Esto sugiere que los factores de riesgo de suicidio son un elemento dinámico, que se modifica con el tiempo. ABSTRACT 217 REVISTA DE SALUD PÚBLICA Volumen 6 (3), Noviembre 2004 218 Characteristics of suicides in Bogotá, 1985-2000
Actas españolas de psiquiatría, 2015
To empirically identify schizophrenia neurocognitive subtypes and establish their association wit... more To empirically identify schizophrenia neurocognitive subtypes and establish their association with clinical characteristics. Sustained attention, executive function, facial emotion recognition, verbal learning, and working memory tests were applied to 253 subjects with schizophrenia. We identified neurocognitive subtypes by a latent class analysis of the tests results. After, we made a search for the association of these subtypes with clinic characteristics. We identified four neurocognitive subtypes: 1) “Global cognitive deficit”, 2) “Memory and executive function deficit”, 3) “Memory and facial emotion recognition deficit,” and 4) “Without cognitive deficit.” In comparison with the subtype “without cognitive deficit,” we found that the “memory and executive function deficit subtype” and the “global cognitive deficit subtype” had a higher frequency of male, unemployed, severe impairment, and adheren...
Nature biotechnology, 2001
Peptide nucleic acids (PNAs) may be a potent tool for gene function studies in medically importan... more Peptide nucleic acids (PNAs) may be a potent tool for gene function studies in medically important parasitic organisms, especially those that have not before been accessible to molecular genetic knockout approaches. One such organism is Entamoeba histolytica, the causative agent of amebiasis, which infects about 500 million people and is the cause of clinical disease in over 40 million each year, mainly in the tropical and subtropical world. We used PNA antisense oligomers to inhibit expression of an episomally expressed gene (neomycin phosphorotransferase, NPT) and a chromosomal gene (EhErd2, a homolog of Erd2, a marker of the Golgi system in eukaryotic cells) in axenically cultured trophozoites of E. histolytica. Measurement of NPT enzyme activity and EhErd2 protein levels, as well as measurement of cellular proliferation, revealed specific decreases in expression of the target genes, and concomitant inhibition of cell growth, in trophozoites treated with micromolar concentrations...
BMC Cancer, 2015
Background: Analysing human papillomavirus (HPV) viral load is important in determining the risk ... more Background: Analysing human papillomavirus (HPV) viral load is important in determining the risk of developing cervical cancer (CC); most knowledge to date regarding HPV viral load and cervical lesions has been related to HPV-16. This study evaluated the association between the viral load of the six most prevalent high-risk viral types in Colombia and cervical intraepithelial neoplasia (CIN) frequency. Methods: 114 women without CIN and 59 women having CIN confirmed by colposcopy, all of them positive by conventional PCR for HPV infection in the initial screening, were included in the study. Samples were tested for six high-risk HPV types to determine viral copy number by real-time PCR. Crude and adjusted odds ratios (OR a ) were estimated for evaluating the association between each viral type's DNA load and the risk of cervical lesions occurring.
A serological test for detecting HPV-infected females at risk of developing cervical cancer could... more A serological test for detecting HPV-infected females at risk of developing cervical cancer could 2 be based on conserved low antigenic L1-peptides specifically recognized by antibodies from 3 high-risk human papillomavirus (HR-HPV) infected cervical lesion patients. The aim was to 4 assess the ability of L1-peptides 18283, 18294 and 18301 to identify these females compared to 5
Objective: To describe patient mortality among patients with vulvar cancer at the National Cancer... more Objective: To describe patient mortality among patients with vulvar cancer at the National Cancer Institute of Colombia (INC). Materials and Methods: Retrospective cohort study among vulvar cancer patients at the INC from 1990-2006. Survival estimated by Kaplan-Meyer; comparison with logarithmic trial rankings. Results: 303 patients were diagnosed with vulvar cancer, including. One hundred and ninety cases fulfilled inclusion criteria. Average
Revista Colombiana de Cancerología, 2010
Fecha de recepción: 29 de julio del 2010. Fecha de aprobación: 2 de noviembre del 2010 Resumen Ob... more Fecha de recepción: 29 de julio del 2010. Fecha de aprobación: 2 de noviembre del 2010 Resumen Objetivo: efectuar la adaptación cultural de la versión 2.0 en Español neutro del cuestionario EORTC QLQ CR-29. Método: se siguió el algoritmo propuesto por el grupo de calidad de vida del EORTC efectuando traducción, comparación de traducciones, traducción inversa y prueba piloto. Resultados: se efectuaron cambios en los términos usados para calificar las opciones de respuesta de los ítems. En cuatro de los ítems se realizaron modificaciones en algunas palabras del instrumento. En la prueba piloto se constató que los cambios realizados permitían más facilidad en la comprensión del instrumento. Conclusión: se cuenta con una versión adaptada del cuestionario EORTC QLQ CR-29 para ser usada en Colombia, que puede ser sometida a los procesos de validación para establecer sus características psicométricas al ser usada en la valoración de calidad de vida relacionada con la salud de los pacientes con cáncer de recto. Palabras clave: calidad de vida, traducción, adaptación cultural, cuestionarios, neoplasia de recto Abstract Objective: To validate a cross-cultural version of the EORTC QLQ CR-29 questionnaire version 2.0 (neutral Spanish) for use in Colombian patients. Methods: The EORTC quality of life group algorithm was applied including translation, translation comparison, reverse translation, Documento descargado de http://www.elsevier.es el 23/04/2016. Copia para uso personal, se prohíbe la transmisión de este documento por cualquier medio o formato. REV COLOMB CANCEROL 2010;14(4):189-198 190 ADAPTACIÓN CULTURAL DEL FORMULARIO EORTC QLQ CR-29 PARA SU APLICACIÓN EN PACIENTES CON CÁNCER DE RECTO EN EL INSTITUTO NACIONAL DE CANCEROLOGÍA DE COLOMBIA
![Research paper thumbnail of [Factors associated with early psychiatric rehospitalization]](https://attachments.academia-assets.com/43806864/thumbnails/1.jpg)
Biomédica : revista del Instituto Nacional de Salud
Early psychiatric rehospitalization is defined as the readmission within the first three months a... more Early psychiatric rehospitalization is defined as the readmission within the first three months after discharge. To determine risk factors for early rehospitalization through the evaluation of two scenarios: readmission within three months and within one month post-discharge. A prospective cohort study was conducted including 214 patients attending a psychiatric hospital in Bogotá. The follow-up included one year post discharge. A total of 311 hospitalization events were analyzed. GEE models for longitudinal data were used to deal with repeated measures in the statistical analysis. Using the three-month criteria, early rehospitalization was found in 49.5% of 311 hospitalization events, while the one-month criteria was found in 31% of them. The three-month model showed that marital status (divorced-separated), diagnosis of substances use disorder, diagnosis related to medical condition and discharge produced by remission are factors associated with the outcome. The one-month model sh...
This is a specification for the network architecture and functionalityof the Rapidly Deployable R... more This is a specification for the network architecture and functionalityof the Rapidly Deployable Radio Network. Invariants for each protocollayer, as well as configuration, reconfiguration, link quality, and mobilityare specified. Implementation of high level functionality is prioritized,while refraining from over-specifying some of the interesting areas of research.Existing standards and areas of research are identified providinga framework for the development of the
Revista Española de Enfermedades Digestivas, 2012
previous studies with patients having cancer have shown that quality of life scores depend on the... more previous studies with patients having cancer have shown that quality of life scores depend on the clinical stage of the disease (the more advanced the disease, the worst quality of life). in a prospective study we studied 317 patients with gastric or colorectal cancer attending the Instituto Nacional de Cancerología between 2010 and 2011; the patients completed the EORTC QLQ-C30 before receiving treatment. This instrument measures quality of life in 15 domains. Scores of each domain were compared according to tumor stage. Differential Item Functioning was measured across neoplasm staging and tumor localization. 145 patients (45.7%) were diagnosed with colorectal cancer. According to clinical staging, differences in quality of life scores were observed in 4 of 15 domains (physical and social functioning, anorexia). Most of the differences in quality of life domains depended on tumor localization (patients with colorectal cancer had the highest scores in quality of life) and sex (women reported better scores). These differences seemed to be independent of item properties. The construct was more adequately measured with items that explore the construct using a general approach. in this group of patients with colorectal and gastric cancer quality of life scores were more related with tumor localization than with clinical stage.
Biomédica : revista del Instituto Nacional de Salud, 2014
The presence of carbapenemase-producing Enterobacteriaceae in hospitals is increasingly common. P... more The presence of carbapenemase-producing Enterobacteriaceae in hospitals is increasingly common. Patients with advanced cancer who require invasive means for diagnosis, treatment or palliative care, and the use of broad-spectrum antimicrobials to treat secondary infections show increased susceptibility to infections caused by these bacteria. To report the behavior of carbapenemase-producing Klebsiella pneumoniae (CPKP) isolates at the Instituto Nacional de Cancerología in Bogotá between January 2010 and December 2012. By analyzing the database kept by the infection committee of the institution, as well as the records of patients with CPKC isolates, we identified and described the epidemiology of detected cases. Outbreaks were determined by using quality control statistical tools. Between January 2010 and December 2012, we found 45 patients with CPKC isolates recovered from any sample. There were more isolates from patients with malignant solid tumors. CPKC isolates from urine samples...
The Brazilian journal of infectious diseases : an official publication of the Brazilian Society of Infectious Diseases
Bloodstream infection by Candida species has a high mortality in Latin American countries. The ai... more Bloodstream infection by Candida species has a high mortality in Latin American countries. The aim of this study was to describe the characteristics of patients with documented bloodstream infections caused by Candida species in third level hospitals and determine the risk factors for in-hospital-mortality. Patients from seven tertiary-care hospitals in Bogotá, Colombia, with isolation of a Candida species from a blood culture were followed prospectively from March 2008 to March 2009. Epidemiologic information, risk factors, and mortality were prospectively collected. Isolates were sent to a reference center, and fluconazole susceptibility was tested by agar-based E-test. The results of susceptibility were compared by using 2008 and 2012 breakpoints. A multivariate analysis was used to determinate risk factors for mortality. We identified 131 patients, with a median age of 41.2 years. Isolates were most frequently found in the intensive care unit (ICU). Candida albicans was the most...
![Research paper thumbnail of [Effect of adequate initial antimicrobi al therapy on mortality in critical patients with Pseudomonas aeruginosa bacteremia]](https://attachments.academia-assets.com/44915177/thumbnails/1.jpg)
Biomédica : revista del Instituto Nacional de Salud, 2014
Among hospital-acquired infections, bacteremia is one of the leading causes of mortality worldwid... more Among hospital-acquired infections, bacteremia is one of the leading causes of mortality worldwide, especially among intensive care unit patients, where it is more frequent. Pseudomonas aeruginosa is one of the most aggressive agents causing bacteremia. To evaluate the association between initial antimicrobial therapy and hospital mortality in these patients. A multicenter and retrospective cohort study was conducted between 2005 and 2008. Antimicrobial therapy was considered adequate if it included at least one intravenous antibiotic to which the P. aeruginosa isolate was susceptible in vitro, was administered at the recommended dose and frequency for bacteremia, and initiated within the first 48 hours from diagnosis. The main outcome was 30-day hospital mortality. Patients were paired according to exposure level using propensity score matching, and then a parametric survival model was fitted. One hundred and sixty four patients were included. Median age and the APACHE II score wer...
Revista Colombiana de Cancerología, 2012
ABSTRACT
Biomédica, 2005
Introducción. La evidencia disponible sugiere que algunos signos neurológicos atribuidos al uso d... more Introducción. La evidencia disponible sugiere que algunos signos neurológicos atribuidos al uso de neurolépticos son realmente manifestaciones secundarias de trastornos psicóticos. Objetivo. Se efectuó el presente estudio con el objetivo de evaluar el papel del signo glabelar como componente clínico del parkinsonismo secundario inducido por neurolépticos. Materiales y métodos. Se evaluó un grupo de pacientes con parkinsonismo secundario inducido por neurolépticos, utilizando la escala de Simpson y Angus para efectos colaterales extrapiramidales. La contribución del signo glabelar en el síndrome global se evaluó mediante técnicas de análisis factorial. Resultados. Se evaluaron 103 pacientes, de los cuales, 52% correspondía a mujeres, con parkinsonismo secundario inducido por neurolépticos. La mayoría de pacientes recibieron haloperidol como tratamiento antipsicótico. Los diagnósticos más frecuentes fueron los trastornos afectivos y los esquizofrénicos. El ítem correspondiente al reflejo glabelar mostró el promedio de covarianza interítem más alto y el mayor valor de unicidad. Los puntajes de alfa de Cronbach de la escala aumentaron al retirar de ésta el ítem correspondiente al signo glabelar. Conclusión. Nuestros hallazgos sugieren que el signo glabelar mide una condición diferente del parkinsonismo secundario inducido por neurolépticos. Sugerimos que este hallazgo clínico no sea utilizado para medir la evolución de la respuesta neurológica a los antipsicóticos.
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Papers by Ricardo Sánchez