RESUMO
BACKGROUND AND AIMS: Benzene is a group I carcinogen, which has been associated with leukemia and myelodysplastic syndrome. Moreover, it has been proposed that polymorphisms in benzene metabolizing genes influence the outcomes of benzene exposure in the human body. This systematic review aims to elucidate the existent relationship between genetic polymorphisms and the risk of developing adverse health effects in benzene-exposed workers. METHODS: Three databases were systematically searched until April 2020. The preferred reporting items for systematic reviews and meta-analyses method was used to select articles published between 2005 and 2020. Quality assessment and risk of bias were evaluated by the Newcastle-Ottawa scale. RESULTS: After full-text evaluation, 36 articles remained out of 645 initially screened. The most studied health effects within the reviewed papers were chronic benzene poisoning, hematotoxicity, altered urinary biomarkers of exposure, micronucleus/chromosomal aberrations, and gene methylation. Furthermore, some polymorphisms on NQO1, GSTT1, GSTM1, MPO, and CYP2E1, among other genes, showed a statistically significant relationship with an increased risk of developing at least one of these effects on benzene-exposed workers. However, there was no consensus among the reviewed papers on which specific polymorphisms were the ones associated with the adverse health-related outcomes, except for the NQO1 rs1800566 and the GSTT1 null genotypes. Additionally, the smoking habit was identified as a confounder, demonstrating worse health outcomes in exposed workers that smoked. CONCLUSION: Though there is a positive relationship between genetic polymorphisms and detrimental health outcomes for benzene-exposed workers, broader benzene-exposed cohorts that take into account the genetic diversity of the population are needed in order to determine which specific polymorphisms incur in health risks.
RESUMO
BACKGROUND: Culturing primary epithelial cells has a major advantage over tumor-derived or immortalized cell lines as long as their functional phenotype and genetic makeup are mainly maintained. The swine model has shown to be helpful and reliable when used as a surrogate model for human diseases. Several porcine cell lines have been established based on a variety of tissues, which have shown to extensively contribute to the current understanding of several pathologies, especially cancer. However, protocols for the isolation and culture of swine gastric epithelial cells that preserve cell phenotype are rather limited. We aimed to develop a new method for establishing a primary epithelial cell culture from the fundic gland region of the pig stomach. RESULTS: Mechanical and enzymatic dissociation of gastric tissue was possible by combining collagenase type I and dispase II, protease inhibitors and antioxidants, which allowed the isolation of epithelial cells from the porcine fundic glands showing cell viability > 90% during the incubation period. Gastric epithelial cells cultured in RPMI 1640, DMEM-HG and DMEM/F12 media did not contribute enough to cell adhesion, cluster formation and cell proliferation. By contrast, William's E medium supplemented with growth factors supports confluency and proliferation of a pure epithelial cell monolayer after 10 days of incubation at 37 °C, 5% CO2. Mucin-producing cell phenotype of primary isolates was confirmed by PAS staining, MUC1 by immunohistochemistry, as well as the expression of MUC1 and MUC20 genes by RT-PCR and cDNA sequencing. Swine gastric epithelial cells also showed origin-specific markers such as cytokeratin cocktail (AE1/AE3) and cytokeratin 18 (CK-18) using immunohistochemical and immunofluorescence methods, respectively. CONCLUSIONS: A new method was successfully established for the isolation of primary gastric epithelial cells from the fundic gland zone through a swine model based on a combination of tissue-specific proteases, protease inhibitors and antioxidants after mechanical cell dissociation. The formulation of William's E medium with growth factors for epithelial cells contributes to cell adhesion and preserves functional primary cells phenotype, which is confirmed by mucin production and expression of typical epithelial markers over time.
Assuntos
Separação Celular/métodos , Células Epiteliais/citologia , Estômago/citologia , Animais , Sequência de Bases , Biomarcadores/metabolismo , Proliferação de Células , Sobrevivência Celular , Células Cultivadas , Células Epiteliais/metabolismo , Regulação da Expressão Gênica , Células HeLa , Humanos , Masculino , Mucinas/genética , Mucinas/metabolismo , Fenótipo , SuínosRESUMO
Resumen La infección por Helicobacter pylori se asocia con enfermedades gastroduodenales como gastritis crónica, úlcera péptica y adenocarcinoma gástrico. Actualmente se dispone de diferentes esquemas terapéuticos, sin embargo, el uso indiscriminado de antibióticos generó resistencia en este agente, razón para estudiar alternativas y reevaluar los criterios que determinan la selección de un esquema en específico. El objetivo de esta revisión fue describir los principios generales de tratamiento de acuerdo a guías de referencia y recomendaciones de autores independientes, y exponer el uso de la rifabutina como alternativa terapéutica. En la búsqueda bibliográfica se usaron los términos "Helicobacter pylori" AND "rifabutin", en las bases de datos PubMed, SciELO y el motor de búsqueda Google Scholar®. La evidencia actual sugiere que el uso de rifabutina como terapia de rescate es apropiado y seguro, y sería la alternativa ideal en casos de multirresistencia o difícil acceso a pruebas de susceptibilidad antibiótica. MÉD.UIS.2022;35(1): 31-42.
Abstract Helicobacter pylori infection is associated with gastroduodenal diseases such as chronic gastritis, peptic ulcer, and gastric adenocarcinoma. Nowadays, there are different therapeutic regimens, however, the indiscriminate use of antibiotics generated resistance in this agent, reason to study alternatives and reevaluate the criteria that determines the selection of a specific regimen. The aim of this review was to describe the general principles of treatment according to reference guidelines and recommendations of independent authors, and to present the use of rifabutin as a therapeutic alternative. The bibliographic search was performed using the terms "Helicobacter pylori" AND "rifabutin" in the databases PubMed, SciELO and the search engine Google Scholar®. Current evidence suggests that the use of rifabutin as rescue therapy is appropriate and safe, and would be an ideal alternative in cases of multidrug resistance or difficult access to antibiotic susceptibility tests. MÉD.UIS.2022;35(1): 31-42.
Assuntos
Humanos , Helicobacter pylori , Rifabutina , Úlcera Péptica , Neoplasias Gástricas , GastriteRESUMO
Resumen Helicobacter pylori (H. pylori) es un bacilo gramnegativo microaerófilo, capaz de colonizar la mucosa gástrica. Este microorganismo infecta a más de la mitad de la población mundial, por lo que se ha convertido en la infección bacteriana más común. La prevalencia de la infección y de las enfermedades asociadas a ella es alta, sobre todo en países en vías de desarrollo. El tratamiento recomendado para la erradicación es la triple terapia; sin embargo, su eficacia ha disminuido por el desconocimiento del patrón de susceptibilidad bacteriano por parte del personal médico y dada la aparición de cepas resistentes. La resistencia en H. pylori se asocia con la capacidad de adaptación de la bacteria a ambientes hostiles y al uso de los antibióticos. En Colombia, existen reportes acerca de que H. pylori presenta resistencia a amoxicilina, metronidazol, claritromicina, furazolidona, levofloxacina y tetraciclina. Los estudios del patrón de susceptibilidad determinaron que la frecuencia de resistencia de H. pylori es variable y demuestran la falta de datos en la mayoría del territorio del país. Sobre la base de lo anterior, el objetivo de esta revisión es describir los porcentajes de resistencia de H. pylori a los antibióticos amoxicilina, metronidazol, claritromicina, furazolidona, levofloxacina y tetraciclina, usados en el tratamiento de la infección en los estudios realizados en Colombia.
Abstract Helicobacter pylori (H. pylori) is a microaerophilic gram-negative bacillus that colonizes the gastric mucosa. It infects more than half the world's population, making it the most common bacterial infection. The prevalence of infection and associated diseases is high in developing countries. The recommended treatment for its eradication is triple therapy; however, its efficacy has decreased due to the lack of knowledge of the bacterial susceptibility pattern among the medical staff and the emergence of resistant strains. H. pylori susceptibility is associated with the bacteria's ability to adapt to hostile environments and the use of antibiotics. In Colombia, it has been reported that H. pylori is resistant to amoxicillin, metronidazole, clarithromycin, furazolidone, levofloxacin, and tetracycline. Studies on the susceptibility pattern have determined that the frequency of H. pylori susceptibility is variable and demonstrate the lack of data in most of the Colombian territory. With this in mind, the objective of this review is to describe the percentage of resistance to amoxicillin, metronidazole, clarithromycin, furazolidone, levofloxacin and tetracycline, which are used for the treatment of H. pylori infection, according to studies conducted in Colombia.