Car T Cells in Solid Tumors: Overcoming Obstacles.

Chimeric antigen receptor T cell (CAR T cell) therapy has emerged as a prominent adoptive cell therapy and a therapeutic approach of great interest in the fight against cancer. This approach has shown notorious efficacy in refractory hematological neoplasm, which has bolstered its exploration in the field of solid cancers. However, successfully managing solid tumors presents considerable intrinsic challenges, which include the necessity of guiding the modified cells toward the tumoral region, assuring their penetration and survival in adverse microenvironments, and addressing the complexity of identifying the specific antigens for each type of cancer. This review focuses on outlining the challenges faced by CAR T cell therapy when used in the treatment of solid tumors, as well as presenting optimizations and emergent approaches directed at improving its efficacy in this particular context. From precise localization to the modulation of the tumoral microenvironment and the adaptation of antigen recognition strategies, diverse pathways will be examined to overcome the current limitations and buttress the therapeutic potential of CAR T cells in the fight against solid tumors.

Pregnancy-Associated Atypical Hemolytic Uremic Syndrome: A Case Report with MCP Gene Mutation and Successful Eculizumab Treatment.

Pregnancy-associated atypical hemolytic uremic syndrome (P-aHUS) is a rare condition characterized by microangiopathic hemolytic anemia and kidney injury from thrombotic microangiopathy. P-aHUS occurs in approximately 1 in 25,000 pregnancies and is strongly related to complement dysregulation and pregnancy-related disorders, such as preeclampsia, eclampsia, and hemolysis, elevated liver enzymes, low platelet (HELLP) syndrome, resulting in adverse perinatal and fetal outcomes. Complement dysregulation in P-aHUS is commonly attributed to genetic mutations or autoantibodies affecting complement factors, including CFH , CFI , and MCP. We present a case of a 25-year-old primigravida who experienced severe preeclampsia and HELLP syndrome followed by the development of complicated P-aHUS during the early postpartum period. The patient exhibited severe clinical manifestations, including hypertensive emergency, central nervous system involvement, renal impairment, and microangiopathic hemolytic anemia. Timely initiation of eculizumab therapy resulted in successful disease remission. Further genetic analysis revealed a likely rare pathogenic MCP gene variant.

Frailty status improvement after kidney transplantation.

INTRODUCTION: Frailty is a clinical syndrome characterized by a decrease in strength, resistance and body physiological condition, making the individual more vulnerable, and increasing his/her risk of dependence and death. Kidney transplant (KT) is currently the best end-stage renal disease therapeutic alternative for certain individuals. Frailty status occurs in approximately 20% of KT patients. Thus, it was evaluated if there would be any change in frailty status level in a population of adult patients on chronic HD after receiving KT. MATERIAL AND METHOD: A cross-sectional study was conducted on a population of adult hemodialysis patients (n: 57), with the objective of evaluating if there was a significant change in their clinical frailty score (CFS) after 6 months of KT. For the statistical analysis, the Student's t-test, and the test of statistical significance between two proportions were applied. RESULTS: Mean CFS before KT was 4 (vulnerable), and after KT was 3 (robust). CFS value was significantly lower after KT (p value < 0.01). CONCLUSION: A significant improvement was found between pre- and post-transplant clinical frailty scores in hemodialysis adult patients.

Comparative Analysis of In-House RT-qPCR Detection of SARS-CoV-2 for Resource-Constrained Settings.

We developed and standardized an efficient and cost-effective in-house RT-PCR method to detect severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We evaluated sensitivity, specificity, and other statistical parameters by different RT-qPCR methods including triplex, duplex, and simplex assays adapted from the initial World Health Organization- (WHO) recommended protocol. This protocol included the identification of the E envelope gene (E gene; specific to the Sarvecovirus genus), RdRp gene of the RNA-dependent RNA polymerase (specific for SARS-CoV-2), and RNase P gene as endogenous control. The detection limit of the E and the RdRp genes were 3.8 copies and 33.8 copies per 1 µL of RNA, respectively, in both triplex and duplex reactions. The sensitivity for the RdRp gene in the triplex and duplex RT-qPCR tests were 98.3% and 83.1%, respectively. We showed a decrease in sensitivity for the RdRp gene by 60% when the E gene acquired Ct values > 31 in the diagnostic tests. This is associated with the specific detection limit of each gene and possible interferences in the protocol. Hence, developing efficient and cost-effective methodologies that can be adapted to various health emergency scenarios is important, especially in developing countries or settings where resources are limited.

Immune Lymphocyte Infiltrate and its Prognostic Value in Triple-Negative Breast Cancer.

Triple-negative breast cancer (TNBC) occurs more frequently in young (<50 years) non-Hispanic black and Hispanic/Latina women. It is considered the most aggressive subtype of breast cancer, although, recently, immune infiltrate has been associated with long-term survival, lower risk of death and recurrence, and response to neoadjuvant chemotherapy. The aim of this review was to evaluate the clinical impact of the immune infiltrate in TNBC by discussing whether its prognostic value varies across different populations. A comprehensive systematic search in databases such as PubMed and Web of Science was conducted to include papers focused on tumor-infiltrating lymphocytes (TILs) in TNBC in different population groups and that were published before January 2021. TNBC patients with higher levels of TILs had longer overall survival and disease-free survival times compared with TNBC patients with low TIL levels. Similar results were observed for CD4+, CD8+ TIL populations. On the other hand, patients with high TIL levels showed a higher rate of pathological complete response regardless of the population group (Asian, European, and American). These results altogether suggest that TIL subpopulations might have a prognostic role in TNBC, but the underlying mechanism needs to be elucidated. Although the prognosis value of TILs was not found different between the population groups analyzed in the revised literature, further studies including underrepresented populations with different genetic ancestries are still necessary to conclude in this regard.

Glomerular Diseases in the Colombian Caribbean: Data from the Colombian Nephropathy Registry (NEFRORED®).

Our study aimed to describe the glomerular diseases, both primary glomerular disease (PGD) and secondary glomerular disease (SGD) in the Colombian Caribbean based on the first regional Colombian Nephropathy Registry (NEFRORED®). A descriptive and retrospective study of adult patients with glomerular diseases from the Colombian Caribbean region was made. All diagnoses by renal biopsy with light microscopy and immunofluorescence obtained between January 2008 and June 2018 were recorded. Eight hundred and seventy-one renal biopsies were obtained. The main clinical indication for biopsy was nephritic syndrome (36%). SGD was more frequent than PGD (55% vs. 45%). Within SGD group, lupus nephritis (LN) was the most frequent etiology (83%). Within PGD group, membranous nephropathy (33%) and focal segmental glomerulosclerosis (FSGS) (19%) were the most common glomerular diseases. At a 24-month follow-up, the patients with FSGS and paraproteinemia-mediated glomerular disease had the worst renal survival prognosis. This is the first Colombian Nephropathy Registry in a Caribbean population, demonstrating a high predominance of SGD due to LN.

Optimizing dialysis dose in the context of frailty: an exploratory study.

INTRODUCTION: Frailty is a multicausal syndrome characterized by a decrease in strength, resistance and physiological function, which makes the individual vulnerable and dependent, and increases his/her mortality. This syndrome is more prevalent among older individuals, and chronic kidney disease patients, particularly those on dialysis. Dialysis dose is currently standardized for hemodialysis (HD) patients regardless of their age and functional status. However, it has been postulated that the dialysis dose required in older patients, especially frail ones, should be lower, since it could increase their degree of frailty. Then, the purpose of this study was to evaluate if there would be a correlation between the dose of Kt/V and the degree of frailty in a population of adult patients on HD. MATERIALS AND METHODS: A cross-sectional study with 82 patients on HD in Barranquilla (Colombia) and Lobos (Argentina) was conducted. Socio-demographic and laboratory data, as well as dialysis doses (Kt/V) were recorded and scales of fragility, physical activity, gait and grip strength were applied. Then these data were correlated by a Spearman's correlation and a logistic regression. RESULTS: CFS, social isolation, physical activity, gait speed, and prehensile strength tests were outside the reference ranges in the studied group. No significant correlation was found between dialysis dose and all the above mentioned functional tests. However, a significant and inverse correlation between physical activity and CFS was documented (score - 1.41 (CI - 2.1 to - 0.7). CONCLUSION: No significant correlation was documented between Kt/V value and different parameters of the frailty status, but this status correlated significantly and inversely with physical activity in this group. Frailty status in hemodialysis patients was significantly higher in older individuals, although young individuals were not exempt from it.

Impact of frailty and viral load on acute kidney injury evolution in patients affected by Coronavirus Disease 2019.

This paper describes the main characteristics of coronavirus diseases 2019 (COVID-19) patients suffering from acute kidney injury (AKI) assisted at a high complexity clinic in Barranquilla, Colombia. The patients included in this study (n = 48) were those with a positive diagnosis of COVID-19 confirmed by polymerase chain reaction detection of severe acute respiratory syndrome coronavirus 2, who had developed AKI during their hospital stay. Serum and urine parameters, as well as patient's viral load and clinical frailty scale (CFS) were recorded. A statistical analysis of the recorded parameters, such as comparisons, and correlations between variables of interest, were explored. The prevalence of COVID-19 induced AKI was 41%, being the majority of them classified as AKI network classification 3, with a renal replacement therapy requirement of 29%, and an associated mortality of 73%. AKI patients' mortality showed a significant positive correlation (33%) with patients' CFS score but not with their viral load. COVID-19 induced AKI significantly correlated with patients' frailty status but not to their viral load.

Trastorno por déficit de atención e hiperactividad (TDAH) en niños escolarizados de 6 a 17 años / Attention deficit hyperactivity disorder (ADHD) in schoolchildren aged 6 to 17 years

Objetivo: se buscó determinar la prevalencia del trastorno por déficit de atención e hiperactividad (TDAH) en niños de entre 6 a 17 años escolarizados en Barranquilla, para hacer una caracterización epidemiológica del trastorno en la región Caribe colombiana. Materiales y métodos: se tomaron 383 niños de una institución educativa a los que se les aplicaron pruebas de tamizaje (Checklist y BASC). Aquellos sujetos que registraron una puntuación sugestiva de alguna alteración fueron reprogramados para la realización de la evaluación por medio de la entrevista estructurada (MINI). Resultados: de los 383 sujetos evaluados inicialmente, 178 resultaron ser casos de algún tipo de alteración, de estos se confirmó que 59 (15%) tenían diagnóstico de TDAH, con una proporción de 38 varones y 21 mujeres, lo que arroja una relación 2:1, la distribución por subtipos se dio en 7,3% combinado, 5% inatento y 3,1% hiperactivo. En total, el 23% de los sujetos evaluados presentaron algún trastorno neuropsiquiátrico y se encontró una relación estadísticamente significativa entre el subtipo inatento con la agorafobia y los episodios depresivos, entre el subtipo hiperactivo con el trastorno oposicionista desafiante y el trastorno de angustia y entre la depresión y el riesgo de suicidio con el subtipo combinado. Conclusiones: la prevalencia del TDAH en Barranquilla presenta un comportamiento similar a otras regiones del país, tanto en la prevalencia como en la distribución por subtipos, relación por sexo, tipos de comorbilidades. Estos datos no están sujetos a factores psicosociales, lo que confirmaría la teoría de tener una etiología multifactorial

Objective: we aimed to establish the prevalence of attention-deficit hyperactivity disorder (ADHD) in schoolchildren aged 6 to 17 years in Barranquilla, to obtain an epidemiological perspective of this disorder in the Caribbean region of Colombia. Materials and methods: we selected 383 children enrolled in a single school and administered screening tests (symptoms checklist and BASC). In children with scores that suggested the presence of abnormalities, we scheduled another assessment by means of a structured interview (MINI). Results: of the 383 children that underwent the initial assessment, 178 exhibited abnormalities, of which 59 (15%) received a final diagnosis of ADHD (38 male and 21 women, corresponding to a 2:1 ratio). The distribution by subtypes was 7.3% combined, 5% inattentive and 3.1% hyperactive. Overall, 23% of the children in the sample had some form of neuropsychiatric disorder, and we found that the inattentive type was significantly associated with agoraphobia and episodes of depression and the hyperactive type with oppositional defiant disorder and anxiety disorder, while in the combined type, depression was associated with an increased risk of suicide. Conclusions: the prevalence of ADHD in Barranquilla was similar to the prevalence reported in other regions of Colombia, both overall and for each of the subtypes, and in its distribution by sex or comorbidities. These proportions were not associated to psychosocial factors, which supports the hypothesis of a multifactorial aetiology of ADHD

Impacto sobre la resistencia bacteriana de la revisión previa de la prescripción de antibióticos por el servicio farmacéutico en hospitales del Atlántico(Colombia) / Impact on the bacterial resistance of the previous revision of the prescription of antibiotics by the pharmaceutical service in hospitals of Atlántico (Colombia)

RESUMEN Objetivo: Determinar el impacto sobre la resistencia bacteriana de la revisión previa de la prescripción de antibióticos por parte del servicio farmacéutico en hospitales de mediana y alta complejidad del departamento del Atlántico (Colombia). Metodología: Se analizaron los valores de resistencia de bacterias Gram positivas, Enterobacterias y Gram negativos no fermentadores reportados en cinco institutos prestadores de salud (IPS) del departamento del Atlántico, en dos periodos (preintervención e intervención), de 12 meses cada uno, entre junio de 2015 y mayo de 2017. Resultados: Durante los dos periodos de estudio se identificaron 68 microorganismos en 8590 aislamientos microbiológicos provenientes de muestras de orina (40,3 %), sangre (21,7 %), tejidos (8,5 %) y otras (29,5 %). Los microorganismos aislados más frecuentemente fueron Escherichia coli (28,9 %), Staphylococcus coagulasa negativo (12,1%), Klebsiella pneumoniae (12,0 %), Pseudomonas aeruginosa (11,1 %) y Staphylococcus aureus (7,2 %). Durante los dos periodos la resistencia global osciló entre 27 y 40 %. Durante la Preintervención la resistencia osciló entre el 33 y el 39 %, mientras que durante la Intervención estuvo entre el 27 y 40 %. Al comparar los periodos de estudio solo hubo disminución significativa de la resistencia en los primeros nueve meses del periodo de intervención (p < 0.05). Conclusiones: Los valores de resistencia bacteriana reportados en el periodo de intervención fueron menores que en el periodo de preintervención. Se evidenció que la revisión previa de la prescripción por parte del servicio farmacéutico en las instituciones participantes influye en una disminución significativa de la resistencia bacteriana, pero que esta debe ser tanto continua como incremental.

ABSTRACT Objective: To determine the impact on bacterial resistance of the previous review of the prescription of antibiotics by the pharmaceutical service in medium and high complexity hospitals of the Department of Atlántico (Colombia). Methodology: Resistance values were analyzed for Gram-positive bacteria, Enterobacte-rial and non-fermenting Gram-negative bacteria reported in five health care institutions (IPS) of the Atlántico Department, in two periods (pre-intervention and intervention), of 12 months each between the months of June 2015 and May 2017. Results: During the two study periods, 68 microorganisms were identified in 8,590 microbiological isolates from urine samples (40.3 %), blood samples (21.7 %), tissues (8.5%) and others (29.5 %). The most frequently isolated microorganisms were Escherichia coli (28.9 %), Coagulase Negative Staphylococcus (12.1 %), Klebsiella pneumoniae (12.0 %), Pseudomonas aeruginosa (11.1 %) and S. aureus (7.2 %). During both periods the global resistance ranged between 27 and 40 %. During the Pre-intervention the resistance ranged between 33 and 39 %, while during the Intervention it was between 27 and 40 %. When comparing study periods, there was only significant decrease in resistance in the first nine months of the intervention period (p <0.05). Conclusions: the bacterial resistance values reported during the intervention period were lower than in the pre-intervention period. It was evidenced that the previous revision of the prescription by the pharmaceutical service in the participating institutions influences a significant decrease of the bacterial resistance; but that this must be both continuous and incremental.

Concordancia de la motilidad segmentaria evaluada por ecocardiograma transtorácico y resonancia magnética cardíaca en pacientes con infarto agudo de miocardio / Comparison of segmental contractility evaluated by transthoracic echocardiogram and cardiac magnetic resonance in patients with acute myocardial infarction

Resumen Introducción: La evaluación de la contractilidad segmentaria es un marcador importante para determinar la extensión de la enfermedad coronaria manifestada a través de un evento isquémico cardiaco. La resonancia magnética cardíaca es el patrón estándar para evaluar dicha motilidad; sin embargo, debido al elevado número de exámenes, la disponibilidad de equipos de resonancia magnética y el costo de los exámenes de resonancia magnética, el uso del ecocardiograma transtorácico es el método diagnóstico de elección. Objetivo: Evaluar la concordancia de la evaluación de la motilidad de diferentes segmentos miocárdicos y de agrupación de segmentos por territorios de irrigación arterial obtenidos por resonancia magnética cardiaca y ecocardiograma transtorácico en pacientes hospitalizados por infarto agudo de miocardio. Métodos: A un grupo de pacientes que llegaron al servicio de emergencia por infarto agudo de miocardio, se les realizó ecocardiograma transtorácico y resonancia magnética cardiaca y se compararon los resultados. La resonancia magnética cardiaca fue el valor de referencia a comparar para fracción de eyección y contractilidad segmentaria. Las pruebas comparativas se hicieron a un 95% de confianza mediante el coeficiente de Kappa-Cohen para evaluar la concordancia entre las medidas. Resultados: No se encontraron diferencias entre la fracción de eyección del ventrículo izquierdo medida por ecocardiograma transtorácico y resonancia magnética cardiaca. Los territorios irrigados por las arterias coronarias descendente anterior y circunfleja tenían una concordancia mediana y buena. En aquellos asociados con la arteria coronaria derecha la concordancia fue baja y media. Conclusiones: La evaluación de la fracción de eyección por ecocardiograma transtorácico no difiere de la evaluación por resonancia magnética cardiaca. En la evaluación de la motilidad segmentaria, la resonancia magnética cardiaca es mejor que el ecocardiograma.

Abstract Introduction: The evaluation of segmental contractility is an important marker to determine the extent of the coronary disease manifested by an ischaemic event. Cardiac magnetic resonance is the standard pattern to evaluate this contractility. However, due to lower availability of magnetic resonance equipment, as well as the increased cost of magnetic resonance tests, the use of the transthoracic echocardiogram is the diagnostic method of choice. Objective: The aim of the study is to compare the evaluation of the motility of different myocardial segments and segments grouped by coronary artery supply territories obtained by cardiac magnetic resonance and transthoracic electrocardiogram performed on patients admitted to hospital with acute myocardial infarction. Methods: A cardiac magnetic resonance and transthoracic electrocardiogram was performed on a group of patients that arrived in the Emergency Department due to an acute myocardial infarction, and the results were compared. The cardiac magnetic resonance was the reference value to compare for the ejection fraction and segmental contractility. Comparative tests were performed with 95% confidence limits using a Kappa-Cohen coefficient to evaluate the agreement between the measurements. Results: No differences were found between the left ventricular ejection fraction measured by cardiac magnetic resonance and transthoracic electrocardiogram. There was average and good agreement in the coronary and circumflex artery supply territories, respectively. In those associated with the right coronary artery, the concordance was low and average. Conclusions: There was no difference between the evaluation of the ejection fraction by transthoracic electrocardiogram or that by cardiac magnetic resonance. In the evaluation of segmental motility, cardiac magnetic resonance was better than transthoracic electrocardiogram.

Transfusiones en pediatría / Transfusions in paediatrics

Resumen La transfusión es la infusión de componentes de la sangre o sangre total en el torrente sanguíneo, considerada una medida terapéutica, de la cual se debe tener un conocimiento fisiológico claro y preciso en la edad pediátrica. El objeto de las transfusiones es aportar los elementos de la sangre en cantidad suficiente y con la mayor capacidad funcional posible en una situación de emergencia. Los conocimientos inmunohematológicos logran evitar, en la mayor parte de los casos, problemas de incompatibilidad y sensibilización. En nuestro país no existen registros claros acerca de los requerimientos transfusionales por edades, o los más solicitados. En este artículo hacemos una revisión sistemática sobre los diferentes componentes sanguíneos, indicaciones, características y dosis, y por último, los efectos transfusionales adversos.

Abstract La transfusión es la infusión de componentes de sangre o sangre entera en el torrente sanguíneo, considerado una medida terapéutica, de la que se debe tener un conocimiento fisiológico claro y preciso en la edad pediátrica. El propósito de las transfusiones es proporcionar los elementos sanguíneos en cantidad suficiente y con la mayor capacidad funcional posible en una situación de emergencia. El conocimiento inmunohematológico es capaz de evitar, en la mayoría de los casos, problemas de incompatibilidad y sensibilización. En nuestro país, no hay registros claros de los requerimientos de transfusión relacionados con la edad o los más solicitados. Realizamos una revisión sistemática de los diferentes componentes, indicaciones, características y dosis de sangre, y por último los efectos transfusionales adversos.

Anemia de células falciformes: una revisión / Sickle Cell Anemia: A review

Resumen La anemia hemolítica más frecuente en la población mundial es la anemia de células falciformes (ACF), con una incidencia de 1/600 recién nacidos en Estados Unidos y en algunas regiones de España con incidencia de 1/5000 neonatos; en Colombia no hay registros respecto a la incidencia y prevalencia. La transmisión de la ACF es autosómica dominante. Los homocigotos (SS) no sintetizan Hb A y poseen eritrocitos con un 90 % de Hb S. El portador o heterocigoto (AS) tiene hematíes con Hb A mayor que 50 % y Hb S de 20 - 40 % y son usualmente asintomáticos. La Hb S se debe a una mutación en el gen de la cadena beta de globina, lo cual conlleva a la polimerización de la Hb en condiciones de baja oxigenación, lo cual origina un cambio en la morfología del eritrocito que adquiere la forma falciforme. La sintomatología es secundaria a la anemia hemolítica crónica, la vaso-oclusión en los diferentes órganos y la asplenia funcional, la cual predispone a la infección. Otras manifestaciones asociadas son el secuestro esplénico, la aplasia eritroide y las complicaciones órgano - especificas, que disminuyen la calidad de vida y predisponen a mayor mortalidad. Su manejo debe realizarse en centros de referencia donde haya un manejo integral, incluyendo el recurso humano y físico, ya que el manejo inadecuado y sus complicaciones disminuyen la sobrevida, la cual no es superior a los 45 años según reportes.

Abstract The most common hemolytic anemia in the world population is sickle cell anemia, with an incidence of 1/600 newborns in the United States and Spain some regions 1/5000 incidence of infants; in Colombia there are no records regarding the incidence and prevalence. ACF transmission is autosomal dominant. Homozygotes (SS) do not synthesize Hb A and possess erythrocytes with 90 % Hb S. The carrier or heterozygous (AS) is greater Hb RBCs with 50 % A and Hb S of 20 - 40 % and are usually asymptomatic. Hb S is due to a mutation in the gene for beta globin chain, leading to polymerization of Hb in low oxygenation, resulting in a change in morphology sickle erythrocyte acquiring form. The symptoms are secondary to chronic hemolytic anemia, vaso-occlusion in the different organs and functional asplenia which predisposes to infection. Other associated manifestations are splenic sequestration, erythroid aplasia complications and organ - specific, which decrease the quality of life and predispose to increased mortality. Its management must be performed in reference centers where there is a comprehensive management including human and physical resources, as improper handling and its complications decreased survival which is not more than 45 years according to reports.

Desarrollo y uso de una interfaz de programación de aplicaciones modificada de GoogleMaps© para la georreferenciación de pacientes con enfermedad glomerular / Development and use of an application programming interface modified from GoogleMaps© for the georeferencing of patients with glomerular disease

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Efecto genotóxico de las mezclas complejas de hidrocarburos en trabajadores de estaciones de servicio de gasolina / Genotoxiceffect of complex hydrocarbon mixtures in workers gasoline service stations

Objetivo: Evaluar el efecto genotóxico de las mezclas complejas de hidrocarburos en los trabajadores de estaciones de servicio de gasolina en Barranquilla (Atlántico, Colombia) a través de la prueba Cometa(CA) alcalina. Materiales y métodos: Se realizó un estudio transversal, prospectivo inferencial de casos y controles. El grupo control estuvo conformado por 15 personas no expuestas laboralmente a hidrocarburos y el expuesto por 38 personas que trabajaron al menos 1 año como despachador de combustible. Se realizó un ensayo cometa alcalino en sangre venosa. Se determinó el efecto genotóxico utilizando el porcentaje de ADN n la cola y por Unidades Arbitrarias de daño. La comparación entre grupos se realizó por la prueba t-student o W-Wilcoxon. Los datos fueron modelados con una regresión simple ajustada. Los análisis de datos fueron realizados con el paquete estadístico R. Resultados: Las edades de los grupos control y experimental fueron de 33±9 y 38±10 años, respectivamente; no hubo diferencia estadísticamente significativa para esta variable (t = -1.82; p-valor > 0,05; a = 95%). Hubo asociación entre Edad y Tiempo de Exposición (x² = 24.9; p-valor < 0,05; a = 95%). El %ADN en la cola para el grupo control fue de 20,67±25,79, mientras que para el grupo expuesto fue 53,35±40,28. El modelo de degradación de ADN es «y=√l(512,687+733,899√1(t))¼. Conclusiones: Las mezclas complejas de heterocíclicos son potencialmente genotóxicas. El daño progresivo se encuentra al 80 % después de 6 años de exposición, siendo igual a los 9 años de exposición que a los 15.

Objective: To evaluate the genotoxic effects of complex mixtures of hydrocarbons in gasoline stations's workers in Barranquilla (Atlántico, Colombia) using the alkaline Comet Assay (CA). Materials and methods: Study was transversal, prospective inferential of case and control. The controls were 15 persons without occupationally exposed to hydrocarbons and the exposed were 38 persons that were working at least one year as fuel dispenser. The alkaline Comet Assay was performed on venous blood. Genotoxic effects was determined throug DNA percentage in tail and damage Arbitrary Units. The comparison between groups was performed by t-student or W-Wilcoxon test. The data were modeled with a simple regression adjusted. The data analyses were performed with the statistical package R. Results: Age of control and experimental groups were 33±9 and 38±10 years respectively, there was no statistically significant difference for this variable (t = -1.82; p-value > 0.05; a = 95 %). There was an association between Age and Exposure Time (x² = 24.9; p-value < 0.05, a = 95%). The %DNA tail for the control group was 20.67 ± 25.79, while for the exposed group was 53.35± 40.28. The DNA degradation model is «y=√ (512.687+733,899√ (t))¼. Conclusions: The complex mixtures of heterocyclic are potentially genotoxic. As the progressive damage is 80 % after 6 years of exposure, being equal damage to the 9 to 15 years of exposure.