ABSTRACT Background: COVID-19 is a pandemic caused by SARS-CoV-2 virus and its association with periodontitis could have adverse outcomes. Objective: To evaluate the association between periodontitis and adverse outcomes of COVID-19. Methodology: A literature review was performed in Google Scholar, SciELO and PubMed Central with the descriptors SARS-CoV-2, COVID-19, periodontitis and periodontal disease consulted in DeCS. Full-text articles in Spanish and English were selected, mainly from peer-reviewed journals. Results: Periodontitis is significantly associated with COVID-19 severity. Probable mechanisms linking periodontitis with severe COVID-19 are favoring viral replication, inflammation due to immune dysfunction, dysbiosis with superimposed bacterial infection, and the presence of comorbidities. Taking biosecurity and hygiene measures in patient care could favor a more favorable clinical course of COVID-19. Conclusions: Periodontitis appears to be associated with unfavorable COVID-19 outcomes, emphasizing the importance of stomatologic care of these patients.

RESUMEN Fundamento: La COVID-19 es una pandemia causada por el virus SARS-CoV-2 y su asociación con la periodontitis podría tener resultados adversos. Objetivo: Evaluar la asociación entre la periodontitis y los resultados adversos de la COVID-19. Desarrollo: Se realizó una revisión bibliográfica en Google Académico, SciELO y PubMed Central con los descriptores SARS-CoV-2, COVID-19, periodontitis y enfermedad periodontal consultados en el DeCS. Se seleccionaron artículos a texto completo en español e inglés, principalmente de revistas arbitradas por pares. La periodontitis se asocia significativamente a la gravedad de la COVID-19. Los probables mecanismos que vinculan a la periodontitis con la COVID-19 grave son el favorecimiento de la replicación viral, la inflamación por disfunción inmune, la disbiosis con infección bacteriana sobreañadida y la presencia de comorbilidades. La toma de medidas de bioseguridad e higiene en la atención de los pacientes podría contribuir a un curso clínico más favorable de la COVID-19. Conclusiones: La periodontitis parece asociarse con resultados desfavorables de la COVID-19, lo que recalca la importancia de la atención estomatológica de estos pacientes.

ABSTRACT Several cases of Guillain Barre Syndrome (GBS) associated with SARS-CoV-2 have been published, most being acute inflammatory demyelinating polyradiculoneuropathy. Between April and December 2020, 1,499 cases of SARS-CoV-2 infection were admitted to Hospital del Salvador, in Santiago, Chile, serving a population of 521,920 adults. In the same period, seven cases of GBS were admitted. Three females had a demyelinated type of GBS associated with SARS-CoV-2 infection. All three presented with progressive flaccid symmetrical areflexic weakness with inability to walk, one needed intubation and mechanical ventilation due to SARS-CoV2 infection. All had a favorable, rapid response to intravenous immunoglobulin. In two patients, the onset of GBS was almost concomitant with SARS-CoV-2 infection. A causal relationship between SARS-CoV-2 and GBS has been questioned since no increase of GBS has occurred during the pandemic. However, a rise in GBS associated with SARS-CoV-2 infection could be hidden due to a general decrease of GBS due to the decrease of all other infections. Lack of reporting due to the pandemic could be an added factor.

Se han publicado varios casos de síndrome de Guillain Barre (SGB) asociados con el SARS-CoV-2, la mayoría de los cuales son polirradiculoneuropatía desmielinizante inflamatoria aguda. Entre abril y diciembre de 2020, se ingresaron 1.499 casos de infección por SARS-CoV-2 en el Hospital del Salvador de Santiago de Chile, que atiende a una población de 521.920 adultos. Durante el mismo período se admitieron siete casos de SGB. Tres pacientes de sexo femenino con SGB tipo desmielinizante asociado a una infección por SARS-CoV-2. Las tres presentaron debilidad simétrica, flácida y arrefléctica progresiva, con incapacidad para caminar, una necesitó intubación y ventilación mecánica debido a la infección por SARS-CoV2. Todas tuvieron una respuesta rápida y favorable a la inmunoglobulina intravenosa. En dos pacientes, la aparición de SGB fue casi concomitante con la infección por SARS-CoV-2. Una relación causal entre el SARS-CoV-2 y SGB ha sido cuestionada ya que no se ha producido ningún aumento de SGB durante la pandemia. Sin embargo, un aumento de SGB asociado con la infección por SARS-CoV-2 podría ocultarse en una disminución general de SGB debido a la disminución de todas las demás infecciones asociadas a este. La sub-notificación debido a la dimensión de la pandemia podría ser también un factor.

Abstract The fluctuation of insect pests in 16 corn genotypes was evaluated, the relationship between the number of insects and grain yield was analyzed, and the most important pests for the conditions of the Campo Verde district in Pucallpa, Ucayali region were identified. 16 genotypes of hard yellow corn were evaluated under a randomized complete block design with three replications; each plot had 72 plants planted at a density of 62,500 plants per hectare. The experiment was carried out in the Campo Verde district, Coronel Portillo province, Ucayali department, Peru. Through the systematic sampling of pests, 15 plants were randomly taken per genotype in which the insects present in them were counted. In total, 12 evaluations were carried out at 10, 18, 26, 34, 41, 48, 54, 62, 69, 75, 84 and 96 days after sowing (dds). Six pests out of a total of seven were the most frequently obtained during the crop cycle, which were identified as: Dalbulus maidis (De Long and Wolcott) (Hemiptera: Cicadellidae), Diabrotica viridula (Fabricius) (Coleoptera: Chrysomelidae), Diatraea saccharalis (Fabricius) (Lepidoptera: Crambidae), Empoasca kraemeri (Ross and Moore) (Hemiptera: Cicadellidae), Oliarus spp. (Hemiptera: Cixiidae) and Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae). On average, of the 12 evaluations carried out on the 16 genotypes, four were the moments in which the highest number of insects per plant was recorded (26, 34, 54 and 96 dds). The regression lines turned out to be not significant; however, the negative relationship between the number of insects and grain yield is evident. Apparently, the three most important pests would be: S. frugiperda, followed by D. maidis and D. viridula, since without these pests the average yield of the 16 genotypes would rise from 2.16 t / ha to 3.1; 2.98 and 2.81 t / ha, respectively.

Resumen Se evaluó la fluctuación de insectos plagas en 16 genotipos de maiz, se analizó la relación entre el número de insectos y el rendimiento de grano, y se identificaron las plagas más importantes para las condiciones del distrito de Campo Verde en Pucallpa, región Ucayali. 16 genotipos de maiz amarillo duro fueron evaluados bajo el diseño de bloques completos al azar con tres repeticiones; cada parcela tuvo 72 plantas sembradas a una densidad de 62.500 plantas por hectárea. El experimento se realizó en el distrito de Campo Verde, provincia de Coronel Portillo, departamento de Ucayali, Perú. Mediante el muestreo sistemático de plagas, se tomaron 15 plantas por genotipo al azar en las que se contaron los insectos presentes en ellas. En total, se realizaron 12 evaluaciones a los 10, 18, 26, 34, 41, 48, 54, 62, 69, 75, 84 y 96 dias después de la siembra (dds). Seis plagas de un total de siete fueron obtenidas con más frecuencia durante el ciclo del cultivo, las que se identificaron como: Dalbulus maidis (De Long y Wolcott) (Hemiptera: Cicadellidae), Diabrotica viridula (Fabricius) (Coleoptera: Chrysomelidae), Diatraea saccharalis (Fabricius) (Lepidoptera: Crambidae), Empoasca kraemeri (Ross y Moore) (Hemiptera: Cicadellidae), Oliarus spp. (Hemiptera: Cixiidae) y Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae). En promedio, de las 12 evaluaciones realizadas sobre los 16 genotipos, cuatro fueron los momentos en los que se registró el mayor número de insectos por planta (26, 34, 54 y 96 dds). Las lineas de regresión resultaron no ser significativas; sin embargo, es evidente la relación negativa entre el número de insectos y el rendimiento de grano. Aparentemente, las tres plagas más importantes serian: S. frugiperda, seguida de D. maidis y D. viridula, ya que sin estas plagas el rendimiento promedio de los 16 genotipos subiría de 2,16 t/ha a 3,1; 2,98 y 2,81 t/ha, respectivamente.

ABSTRACT A review of the basic epigenetic mechanisms, by which heritable changes in phenotype that do not depend on DNA sequence occur, was carried out. These mechanisms determine the memory of cell differentiation in their progeny, so they are a mechanism for controlling the expression of genetic information. DNA methylation and covalent histone modification control the expression of genetic information by interacting with specific proteins in a complex network involving the so-called histone code. This regulation can be modified by various factors, such as diet and physical exercise. Knowledge of these processes has allowed the use of epigenetic therapeutics for some types of cancers and other diseases.

RESUMEN Se realizó una revisión de los mecanismos epigenéticos básicos, por medio de los cuales se producen cambios heredables en el fenotipo que no dependen de la secuencia del ADN. Estos mecanismos determinan la memoria de la diferenciación celular en su progenie, por lo que constituyen un mecanismo de control de la expresión de la información genética. La metilación del ADN y la modificación covalente de las histonas controlan la expresión de la información genética, mediante la interacción con proteínas específicas en una compleja red que involucra el llamado código de histonas. Esta regulación puede ser modificada por diversos factores, como la dieta y el ejercicio físico. El conocimiento de estos procesos ha permitido el empleo de terapéuticas epigenéticas para algunos tipos de cánceres y otras enfermedades.

At central Chile grows the spiny forest of Acacia caven and Prosopis chilensis of which less than 40% of its original surface currently persists, but with no representation into the wilderness protected areas. Owing to the action of cattle, has it been previously suggested a population reduction of P. chilensis coupled to a population increase of A. caven which, nonetheless, has not yet verified empirically. At four sites belonging to two micro-basins in the Metropolitan Region at central Chile (Batuco and Huechún), we assessed the incidence of environmental disturbances (cattle, rabbits, weeds, garbage), the phytosanitary stage, and population structure of P. chilensis, as well as the regeneration dynamics of this tree and A. caven by using Markovian transition matrices. Populations of P. chilensis suffer similar degrees of threats, exhibit a similar but depauperate phytosanitary stage and, consequently, they face a senescent stage prone to disappear when the current adult individuals go death. Furthermore, the population decrease of P. chilensis does not correlate with the previously suggested population increase of A. caven; hence, the tree species characterizing and defining the spiny forest of central Chile are prone to be extinct and with them the vegetation belt. It appears, therefore, as an urgent necessity the establishment of conservation and restoration programs in order to assure the persistence of the spiny forest at the Metropolitan Region in central Chile.

En la zona central de Chile se encuentra el bosque espinoso de Acacia caven y Prosopis chilensis, donde persiste menos del 40% de su superficie original, aunque sin representación en las áreas silvestres protegidas. Debido a la acción del ganado, se ha sugerido una contracción poblacional de P. chilensis acoplado a una expansión poblacional de A. caven lo cual, sin embargo, no ha sido verificado empíricamente. En cuatro sitios correspondientes a dos microcuencas de la Región Metropolitana en Chile (Batuco y Huechún), se evaluó la incidencia de las perturbaciones ambientales (ganado, conejos, malezas, basuras), el estado fitosanitario y estructura poblacional de P. chilensis, así como las dinámicas de regeneración de este árbol y A. caven, mediante el uso de matrices de transiciones Markovianas. Las poblaciones de P. chilensis enfrentan similares grados de amenaza, exhiben un estado fitosanitario similar y deficitario y, consecuentemente, se encuentran en estado senescente prontas a desaparecer una vez muertos los individuos adultos de las siguientes dos generaciones. Además, la contracción poblacional de P. chilensis no se correlaciona con una expansión poblacional de A. caven, por lo cual las dos especies que definen y caracterizan el bosque espinoso de la Región Metropolitana de Chile se encuentran prontas a extinguirse y con ellas el piso vegetacional. Surge, por lo tanto, como necesidad urgente el establecer las medidas de conservación y restauración necesarias para asegurar la persistencia del bosque espinoso en la Región Metropolitana de Chile.

O propósito deste estudo foi avaliar a experiência de cárie entre escolares indígenas (Naporunas) e escolares não-indígenas (colonizadores recentes de origem étnica variada) com idades entre 6 e 12 anos, residentes na bacia amazônica do Equador. Os dados transversais foram obtidos a partir de 1.449 exames clínicos realizados de acordo com os critérios da Organização Mundial da Saúde (OMS). Nove (7,6%) crianças indígenas e 3 (4,5%) crianças não-indígenas não tiveram experiência de cárie na dentição decídua aos 6 anos. O valor médio do ceo-d (SD) entre os escolares indígenas e não-indígenas com idade de 6 anos foi de 6,40 (3,36) e 8,36 (3,93), respectivamente. Sessenta e quatro (54,2%) escolares indígenas e 29 (43,3%) escolares não-indígenas não tiveram experiência de cárie nos primeiros molares permanentes aos 6 anos. Apenas 7 (6,26%) entre as crianças indígenas e 2 (2,6%) entre as não-indígenas não apresentaram cárie aos 12 anos. Os valores médios de CPO-D para os escolares aos 12 anos foram de 4,47 (2,85) entre os escolares indígenas e 5,25 (2,89) entre os escolares não-indígenas. As restaurações foram praticamente ausentes. A incidência de cárie foi alta nos dois grupos, com predominância de lesões não tratadas em todas as idades. Os dados referentes aos escolares indígenas sugerem a adoção de uma alimentação não tradicional. Torna-se necessária uma resposta adequada de saúde oral, baseada principalmente na prevenção e promoção de saúde.

The purpose of this study was to evaluate the caries experience among 6-12-year-old indigenous (Naporunas) and non-indigenous (recent settlers of mixed ethnic origin) schoolchildren, living in the Amazon basin of Ecuador. Cross-sectional data were obtained from 1,449 clinical exams according to the World Health Organization criteria. Nine (7.6%) indigenous and 3 (4.5%) non-indigenous children had no caries experience in their primary dentition at the age of 6. The mean dmft value (SD) among indigenous and non-indigenous children aged 6 was 6.40 (3.36) and 8.36 (3.93), respectively. Sixty-four (54.2%) indigenous and 29 (43.3%) non-indigenous children had no caries experience in their permanent first molars at the age of 6. Only 7 (6.26%) indigenous and 2 (2.60%) non-indigenous children were caries-free at the age of 12. The mean DMFT values (SD) for 12-year-olds were 4.47 (2.85) among indigenous and 5.25 (2.89) among non-indigenous children. Fillings were almost non existent. Caries rates were high among both groups, with untreated carious lesions predominating in all ages. The data of indigenous children suggest adoption of a non-traditional diet. An appropriate oral health response based primarily on prevention and health promotion is needed.