[Hepatitis B in indigenous people in Latin America: a literature reviewHepatite B em indígenas na América Latina: revisão da literatura]. / Hepatitis B en indígenas de América Latina: una revisión de la literatura.

Objective: Identify publications from 2000 to 2020 on hepatitis B in indigenous people in Latin America, to learn about advances and gaps in this field in the last 20 years. Methods: Exploratory review and systematic evidence review. Documents were organized using Excel and Rayyan® software. Results: We selected 30 of 107 articles found: 17 epidemiological studies, 10 document reviews, 2 clinical studies, and 1 letter to the editor. Brazil was the country with the most publications (50%), most of them with an epidemiological approach. The topic most often addressed was hepatitis B prevalence with 22 publications, followed by 11 studies reporting results of molecular studies of the virus, 7 studies on vaccination, 5 studies on risk factors, and 4 publications with topics such as vertical transmission and studies of social issues. Conclusion: Compared to previous reviews by other authors, we saw greater diversity in topics and research methods; however, conventional epidemiological approaches that focus on measuring prevalence of serological markers still predominate. Thus, there is a need for other types of research focused on sociocultural determinants.

Objetivo: Identificar artigos publicados entre 2000 e 2020 sobre hepatite B em indígenas da América Latina, visando a conhecer as conquistas obtidas nos últimos 20 anos e as lacunas existentes com relação a esta doença. Métodos: Foi realizada uma revisão exploratória da literatura com síntese das evidências. O material obtido foi organizado com o uso de Excel® e Rayyan®. Resultados: De 107 artigos encontrados, 30 foram selecionados ­ 17 estudos epidemiológicos, 10 revisões documentais, 2 estudos clínicos e 1 carta ao editor. O Brasil foi o país com o maior percentual de artigos publicados (50%), na sua maioria estudos com enfoque epidemiológico. As áreas temáticas abordadas foram a prevalência de infecção pelo vírus da hepatite B (22 artigos), estudos moleculares do vírus da hepatite (11 estudos), vacinação (7), fatores de risco (5), e temas como transmissão materno-fetal e aspectos sociais (4). Conclusões: Comparado aos estudos de revisão anteriores conduzidos por outros autores, o presente estudo demonstra uma maior variedade de áreas temáticas e metodologias empregadas. No entanto, ainda predominam enfoques epidemiológicos convencionais com foco na avaliação da prevalência de marcadores sorológicos. São necessárias outras linhas de pesquisas enfocando os determinantes socioculturais.

Epidemiology and Genetic Diversity of Hepatitis B Virus and Hepatitis Delta Virus Infection in Indigenous Communities in Colombia.

Despite the universal vaccination program, there are still regions and territories with a high prevalence of Hepatitis B Virus infection (HBV), such as the Amazon basin, where several indigenous communities live. Additionally, Hepatitis Delta Virus (HDV) is a defective that requires the hepatitis B surface antigen (HBsAg) for the assembly and release of de novo viral particles. Therefore, hepatitis D could be the result of HBV/HDV coinfection or HDV superinfection in individuals with chronic hepatitis B. Among the high prevalence HDV populations are indigenous communities of America. This study aims to describe and characterize the frequency of HBV and HDV infection, viral genotypes and HBV immune escape mutants in indigenous populations from different regions of Colombia. The diagnosis of hepatitis B and hepatitis D was confirmed by serological markers. Moreover, the HBV and HDV genome were amplified by PCR and RT-PCR, respectively, and, subsequently, the phylogenetic analysis was performed. We characterized 47 cases of chronic hepatitis B, 1 case of reactivation and 2 cases of occult hepatitis B infection (OBI). Furthermore, a high prevalence of HDV infection was identified in the study population (29.33%, 22/75) and the circulation of several HBV genotypes and subgenotypes (F1b, F3, F4, and D). Interestingly, this is the first report of the HDV genotype I circulation in this country. These findings demonstrated that HBV and HDV infections are still public health problems in indigenous communities in Colombia.

Semiautomatic assessment of whole-body tumor burden with 18F-PSMA-1007 in biochemical recurrent prostate cancer.

OBJECTIVE: The aim of the study was to evaluate the 18F-PSMA-1007 PET/computed tomography (CT) semiautomatic volumetric parameters to assess the whole-body tumor burden and its correlation with prostate-specific antigen (PSA) and Gleason score in patients with biochemically recurrent prostate cancer (PCa). MATERIALS AND METHODS: A total of 110 patients referred for 18F-PSMA-1007 PET/CT due to biochemical recurrence were retrospectively analyzed. Whole-body total lesion prostate-specific membrane antigen (wbTl-PSMA) and whole-body PSMA-derived tumor volume (wbPSMA-TV) metrics on 18F-PSMA-1007 were obtained semiautomatically in dedicated software. A Spearman test was performed to explore the correlation of volumetric imaging parameters with PSA levels and Gleason score. To analyze the association between volumetric measures and PSA subgroups, we used a Kruskal-Wallis test and a Dunn's test to identify each group causing an observed difference. RESULTS: A total of 492 metastatic lesions were analyzed, and a significant correlation was found between wbTL-PSMA (R = 0.63, P < 0.0001) and wbPSMA-TV (R = 0.49, P < 0.0001) with serum PSA. A statistically significant difference with wbTL-PSMA was found in patients with a PSA less than or equal 0.5 ng/ml and PSA in the range of 0.51-1.0 ng/ml. CONCLUSION: 18F-PSMA-1007 PSMA volumetric parameters can provide a quantitative imaging biomarker for whole-body tumor burden.

Influence of Calcium Perchlorate on the Search for Martian Organic Compounds with MTBSTFA/DMF Derivatization.

N-tert-butyldimethylsilyl-N-methyltrifluoroacetamide (MTBSTFA), mixed with the solvent N,N-dimethylformamide (DMF), is used as a derivatizing reagent by the Sample Analysis at Mars (SAM) experiment onboard NASA's Curiosity rover and will soon be utilized by the Mars Organic Molecule Analyzer experiment onboard the ESA/Roscosmos Rosalind Franklin rover. The pyrolysis products of MTBSTFA, DMF, and the MTBSTFA/DMF mixtures, obtained at different temperatures, were analyzed. Two different pyrolysis modes were studied, flash pyrolysis and ramp pyrolysis (35°C/min), to evaluate the potential influence of the sample heating speed on the production of products in space chromatographs. The effect of the presence of calcium perchlorate on the pyrolysis products of MTBSTFA/DMF was also studied to ascertain the potential effect of perchlorate species known to be present at the martian surface. The results show that MTBSTFA/DMF derivatization should be applied below 300°C when using flash pyrolysis, as numerous products of MTBSTFA/DMF were formed at high pyrolysis temperatures. However, when an SAM-like ramp pyrolysis was applied, the final pyrolysis temperature did not appear to influence the degradation products of MTBSTFA/DMF. All products of MTBSTFA/DMF pyrolysis are listed in this article, providing a major database of products for the analysis of martian analog samples, meteorites, and the in situ analysis of martian rocks and soils. In addition, the presence of calcium perchlorate does not show any obvious effects on the pyrolysis of MTBSTFA/DMF: Only chloromethane and TBDMS-Cl (chloro-tertbutyldimethylsilane) were detected, whereas chlorobenzene and other chlorine-bearing compounds were not detected. However, other chlorine-bearing compounds were detected after pyrolysis of the Murchison meteorite in the presence of calcium perchlorate. This result reinforces previous suggestions that chloride-bearing compounds could be reaction products of martian samples and perchlorate.

Influence of Calcium Perchlorate on the Search for Organics on Mars with Tetramethylammonium Hydroxide Thermochemolysis.

The Mars Organic Molecule Analyzer (MOMA) and Sample Analysis at Mars (SAM) instruments onboard the Exomars 2022 and Mars Science Laboratory rovers, respectively, are capable of organic matter detection and differentiating potentially biogenic from abiotic organics in martian samples. To identify organics, both these instruments utilize pyrolysis-gas chromatography coupled to mass spectrometry, and the thermochemolysis agent tetramethylammonium hydroxide (TMAH) is also used to increase organic volatility. However, the reactivity and efficiency of TMAH thermochemolysis are affected by the presence of calcium perchlorate on the martian surface. In this study, we determined the products of TMAH pyrolysis in the presence and absence of calcium perchlorate at different heating rates (flash pyrolysis and SAM-like ramp pyrolysis with a 35°C·min-1 heating rate). The decomposition mechanism of TMAH pyrolysis in the presence of calcium perchlorate was studied by using stepped pyrolysis. Moreover, the effect of calcium perchlorate (at Mars-relevant concentrations) on the recovery rate of fatty acids with TMAH thermochemolysis was studied. Results demonstrate that flash pyrolysis yields more diversity and greater abundances of TMAH thermochemolysis products than does the SAM-like ramp pyrolysis method. There is no obvious effect of calcium perchlorate on TMAH degradation when the [ClO4-] is lower than 10 weight percent (wt %). Most importantly, the presence of calcium perchlorate does not significantly impact the recovery rate of fatty acids with TMAH thermochemolysis under laboratory conditions, which is promising for the detection of fatty acids via TMAH thermochemolysis with the SAM and MOMA instruments on Mars.

Thromboxane receptor activates the AMP-activated protein kinase in vascular smooth muscle cells via hydrogen peroxide.

Thromboxane A2 receptor (TPr) stimulation induces cellular hypertrophy in vascular smooth muscle cells (VSMCs); however, regulation of VSMC hypertrophy remains poorly understood. Here we show that TPr stimulation activates AMP-activated kinase (AMPK), which in turn limits TPr-induced protein synthesis in VSMCs. Exposure of cultured VSMCs to either TPr agonists, IBOP and U46619, or exogenous hydrogen peroxide (H2O2) caused time- and dose-dependent AMPK activation, as evidenced by increased phosphorylation of both AMPK-Thr172 and acetyl-coenzyme A carboxylase-Ser79, a downstream enzyme of AMPK, whereas SQ29548, a selective TPr antagonist, significantly attenuated TPr-enhanced AMPK activation. In parallel, both IBOP and U46619 significantly increased the production of reactive oxygen species such as H2O2. Furthermore, adenoviral overexpression of catalase (an H2O2 scavenger) abolished, whereas superoxide dismutase (which catalyzes H2O2 formation) enhanced, IBOP-induced AMPK activation, suggesting that TPr-activated AMPK was mediated by H2O2. Consistently, exposure of VSMCs to either TPr agonists or exogenous H2O2 dose-dependently increased the phosphorylation of LKB1 (at serines 428 and 307), an AMPK kinase, as well as coimmunoprecipitation of AMPK with LKB1. In addition, direct mutagenesis of either Ser428 or Ser307 of LKB1 into alanine, like the kinase-dead LKB1 mutant, abolished both TPr-stimulated AMPK activation and coimmunoprecipitation. Finally, genetic inhibition of AMPK significantly accentuated IBOP-enhanced protein synthesis, whereas adenoviral overexpression of constitutively active AMPK abolished IBOP-enhance protein synthesis in VSMCs. We conclude that TPr stimulation triggers reactive oxygen species-mediated LKB1-dependent AMPK activation, which in return inhibits cellular protein synthesis in VSMCs.

First Detections of Dichlorobenzene Isomers and Trichloromethylpropane from Organic Matter Indigenous to Mars Mudstone in Gale Crater, Mars: Results from the Sample Analysis at Mars Instrument Onboard the Curiosity Rover.

Chromatographic analysis of the Cumberland mudstone in Gale crater by the Sample Analysis at Mars (SAM) instrument revealed the detection of two to three isomers of dichlorobenzene. Their individual concentrations were estimated to be in the 0.5-17 ppbw range relative to the sample mass. We also report the first detection of trichloromethylpropane and the confirmation of the detection of chlorobenzene previously reported. Supporting laboratory experiments excluded the SAM internal background as the source of those compounds, thus confirming the organic carbon and chlorine of the newly detected chlorohydrocarbons are indigenous to the mudstone sample. Laboratory experiments also demonstrated that the chlorohydrocarbons were mainly produced from chemical reactions occurring in the SAM ovens between organic molecules and oxychlorines contained in the sample. The results we obtained show that meteoritic organics and tested chemical species (a polycyclic aromatic hydrocarbon, an amino acid, and a carboxylic acid) were plausible organic precursors of the chlorinated aromatic molecules detected with SAM, thus suggesting that they could be among the organic molecules present in the mudstone. Results from this study coupled with previously reported detections of chlorinated aromatics (<300 ppbw) indigenous to the same mudstone highlight that organics can be preserved from the harsh surface conditions even at shallow depth. The detection of new chlorohydrocarbons with SAM confirms that organic molecules should have been available in an environment favorable to life forms, strengthening the habitability aspect of Gale crater.

The productivity measurement and enhancement system: a meta-analysis.

Meta-analytic procedures were used to examine data from 83 field studies of the Productivity Measurement and Enhancement System (ProMES). The article expands the evidence on effectiveness of the intervention, examines where it has been successful, and explores moderators related to its success. Four research questions were explored and results indicate that (a) ProMES results in large improvements in productivity; (b) these effects last over time, in some cases years; (c) the intervention results in productivity improvements in many different types of settings (i.e., type of organization, type of work, type of worker, country); and (d) moderator variables are related to the degree of productivity improvement. These moderator variables include how closely the study followed the original ProMES methodology, the quality of feedback given, whether changes were made in the feedback system, the degree of interdependence of the work group, and centralization of the organization. Implications based on these findings are discussed for future use of this intervention, and the system is discussed as an example for evidence-based management.

Hepatitis B en indígenas de América Latina: una revisión de la literatura

[RESUMEN]. Objetivo. Identificar publicaciones realizadas entre los años 2000 y 2020 sobre hepatitis B en indígenas de América Latina, con el fin de conocer avances y vacíos en el tema durante los últimos 20 años. Métodos. Revisión exploratoria y síntesis rápida de la evidencia. El proceso de organización documental se realizó con los programas Excel® y Rayyan®. Resultados. Se seleccionaron 30 de 107 artículos encontrados, 17 corresponden a estudios epidemiológicos, 10 a revisiones documentales, dos estudios clínicos y una carta al editor. Brasil fue el país con más publicaciones (50%), la mayoría con enfoque epidemiológico. La temática más abordada fue la medición de prevalencia de la infección por hepatitis B con 22 publicaciones, le siguieron 11 estudios que informan resultados de estudios moleculares del virus, siete estudios sobre vacunación, cinco estudios sobre factores de riesgo y cuatro publicaciones con temas como la transmisión vertical y estudios sociales. Conclusión. En comparación con revisiones previas realizadas por otros autores, se observa una mayor diversidad en los temas y métodos de investigación utilizados; sin embargo, aún prevalecen los enfoques epidemiológicos convencionales centrados en la medición de la prevalencia de marcadores serológicos. Esto hace necesario encarar otro tipo de investigaciones centradas en los determinantes socioculturales.

[ABSTRACT]. Objective. Identify publications from 2000 to 2020 on hepatitis B in indigenous people in Latin America, to learn about advances and gaps in this field in the last 20 years. Methods. Exploratory review and systematic evidence review. Documents were organized using Excel and Rayyan® software. Results. We selected 30 of 107 articles found: 17 epidemiological studies, 10 document reviews, 2 clinical studies, and 1 letter to the editor. Brazil was the country with the most publications (50%), most of them with an epidemiological approach. The topic most often addressed was hepatitis B prevalence with 22 publications, followed by 11 studies reporting results of molecular studies of the virus, 7 studies on vaccination, 5 studies on risk factors, and 4 publications with topics such as vertical transmission and studies of social issues. Conclusion. Compared to previous reviews by other authors, we saw greater diversity in topics and research methods; however, conventional epidemiological approaches that focus on measuring prevalence of serological markers still predominate. Thus, there is a need for other types of research focused on sociocultural determinants.

[RESUMO]. Objetivo. Identificar artigos publicados entre 2000 e 2020 sobre hepatite B em indígenas da América Latina, visando a conhecer as conquistas obtidas nos últimos 20 anos e as lacunas existentes com relação a esta doença. Métodos. Foi realizada uma revisão exploratória da literatura com síntese das evidências. O material obtido foi organizado com o uso de Excel® e Rayyan®. Resultados. De 107 artigos encontrados, 30 foram selecionados – 17 estudos epidemiológicos, 10 revisões documentais, 2 estudos clínicos e 1 carta ao editor. O Brasil foi o país com o maior percentual de artigos publicados (50%), na sua maioria estudos com enfoque epidemiológico. As áreas temáticas abordadas foram a prevalência de infecção pelo vírus da hepatite B (22 artigos), estudos moleculares do vírus da hepatite (11 estudos), vacinação (7), fatores de risco (5), e temas como transmissão materno-fetal e aspectos sociais (4). Conclusões. Comparado aos estudos de revisão anteriores conduzidos por outros autores, o presente estudo demonstra uma maior variedade de áreas temáticas e metodologias empregadas. No entanto, ainda predominam enfoques epidemiológicos convencionais com foco na avaliação da prevalência de marcadores sorológicos. São necessárias outras linhas de pesquisas enfocando os determinantes socioculturais.

Hepatitis B en indígenas de América Latina: una revisión de la literatura / Hepatitis B in indigenous people in Latin America: a literature review / Hepatite B em indígenas na América Latina: revisão da literatura

RESUMEN Objetivo. Identificar publicaciones realizadas entre los años 2000 y 2020 sobre hepatitis B en indígenas de América Latina, con el fin de conocer avances y vacíos en el tema durante los últimos 20 años. Métodos. Revisión exploratoria y síntesis rápida de la evidencia. El proceso de organización documental se realizó con los programas Excel® y Rayyan®. Resultados. Se seleccionaron 30 de 107 artículos encontrados, 17 corresponden a estudios epidemiológicos, 10 a revisiones documentales, dos estudios clínicos y una carta al editor. Brasil fue el país con más publicaciones (50%), la mayoría con enfoque epidemiológico. La temática más abordada fue la medición de prevalencia de la infección por hepatitis B con 22 publicaciones, le siguieron 11 estudios que informan resultados de estudios moleculares del virus, siete estudios sobre vacunación, cinco estudios sobre factores de riesgo y cuatro publicaciones con temas como la transmisión vertical y estudios sociales. Conclusión. En comparación con revisiones previas realizadas por otros autores, se observa una mayor diversidad en los temas y métodos de investigación utilizados; sin embargo, aún prevalecen los enfoques epidemiológicos convencionales centrados en la medición de la prevalencia de marcadores serológicos. Esto hace necesario encarar otro tipo de investigaciones centradas en los determinantes socioculturales.

ABSTRACT Objective. Identify publications from 2000 to 2020 on hepatitis B in indigenous people in Latin America, to learn about advances and gaps in this field in the last 20 years. Methods. Exploratory review and systematic evidence review. Documents were organized using Excel and Rayyan® software. Results. We selected 30 of 107 articles found: 17 epidemiological studies, 10 document reviews, 2 clinical studies, and 1 letter to the editor. Brazil was the country with the most publications (50%), most of them with an epidemiological approach. The topic most often addressed was hepatitis B prevalence with 22 publications, followed by 11 studies reporting results of molecular studies of the virus, 7 studies on vaccination, 5 studies on risk factors, and 4 publications with topics such as vertical transmission and studies of social issues. Conclusion. Compared to previous reviews by other authors, we saw greater diversity in topics and research methods; however, conventional epidemiological approaches that focus on measuring prevalence of serological markers still predominate. Thus, there is a need for other types of research focused on sociocultural determinants.

RESUMO Objetivo. Identificar artigos publicados entre 2000 e 2020 sobre hepatite B em indígenas da América Latina, visando a conhecer as conquistas obtidas nos últimos 20 anos e as lacunas existentes com relação a esta doença. Métodos. Foi realizada uma revisão exploratória da literatura com síntese das evidências. O material obtido foi organizado com o uso de Excel® e Rayyan®. Resultados. De 107 artigos encontrados, 30 foram selecionados - 17 estudos epidemiológicos, 10 revisões documentais, 2 estudos clínicos e 1 carta ao editor. O Brasil foi o país com o maior percentual de artigos publicados (50%), na sua maioria estudos com enfoque epidemiológico. As áreas temáticas abordadas foram a prevalência de infecção pelo vírus da hepatite B (22 artigos), estudos moleculares do vírus da hepatite (11 estudos), vacinação (7), fatores de risco (5), e temas como transmissão materno-fetal e aspectos sociais (4). Conclusões. Comparado aos estudos de revisão anteriores conduzidos por outros autores, o presente estudo demonstra uma maior variedade de áreas temáticas e metodologias empregadas. No entanto, ainda predominam enfoques epidemiológicos convencionais com foco na avaliação da prevalência de marcadores sorológicos. São necessárias outras linhas de pesquisas enfocando os determinantes socioculturais.

Preschoolers' influence on and help with beverage selection at the grocery store is linked to maternal responsiveness and child beverage intake: An exploratory study.

Children's involvement in beverage selection or purchase has seldom been investigated. The responsiveness dimension of parental feeding styles has been related to healthy maternal feeding practices. Assessing mothers' reports of responsiveness and demandingness in grocery stores may shed light on influences on purchases of sugar-sweetened beverages (SSB) and fruit juice (FJ). Study objectives were to explore whether (1) maternal responsiveness and demandingness were associated with preschoolers' a) help with selection of and b) influence on SSB and FJ purchases during grocery shopping and whether (2) preschoolers' a) help with selection of and b) influence on SSB and FJ purchases were associated with child intake of these beverages. Mothers of 3-to-5-year-old children (n=185) who co-shopped with the child completed the Caregiver Feeding Style Questionnaire, reported frequency of child help with selection and influence on beverage purchase via questionnaire, and provided a one-day weekend food recall for the child. In adjusted logistic regressions, responsiveness was associated with child help selecting FJ (OR=6.50, 95% CI[1.04, 40.75], p<0.05), but not SSB. In multiple regressions, children who frequently helped select or influenced SSB purchases had higher SSB intake, b(SE)=3.63(1.40), t(176)=2.59, and b(SE)=3.18(1.25), t(176)=2.53, p<0.05. Mothers with higher responsiveness were more likely to let their preschoolers select FJ but not SSB during shopping. Children who frequently helped select or influenced SSB purchases had higher SSB intake than children who did so infrequently. Additional parenting behaviors associated with grocery shopping should be explored.

EXPRESIÓN DE LA PROTEÍNA CORE DEL VIRUS DE LA HEPATITIS C EN CÉLULAS HepG2 USANDO EL VIRUS DEL BOSQUE DE SEMLIKI / Hepatitis C virus core protein expression in HepG2 cells using Semliki Forest Virus

RESUMEN El Virus de la Hepatitis C (VHC) codifica la proteína Core. Que, además de ser la subunidad de la cápside, participa en diferentes mecanismos de patogénesis de la infección por VHC. Dado que el sistema de replicación in vitro del VHC presenta limitaciones, el uso de vectores virales podría ser una herramienta útil para estudiar las propiedades de la proteína Core. Con el fin de validar el vector con el Virus del Bosque de Semliki (SFV) para el estudio de Core en células HepG2, se evaluó la expresión de la proteína verde fluorescente (GFP) y la proteína Core utilizando este vector viral. Las expresiones de GFP y Core se detectaron en células HepG2 transducidas con rSFV de 24 a 96 horas postransducción. La expresión de la proteína Core fue inferior a la expresión de GFP en las células HepG2. Teniendo en cuenta que la proteína Core del VHC puede regular la actividad del gen p53, se evaluó el nivel transcripcional de este gen. Se observó una disminución en el nivel de mARN de p53 en las células luego de la transducción, comparado con las células control. Aunque las células transducidas con rSFV-Core presentaron el menor nivel de mARN de p53, la diferencia no fue significativa comparada con las células transducidas con rSFV-GFP. Los resultados confirman que rSFV permite la expresión transitoria de proteínas heterólogas en líneas celulares de hepatoma humano. Se necesitan estudios adicionales para determinar si la expresión disminuida de Core puede deberse a degradación de la proteína viral.

ABSTRACT The Hepatitis C Virus (HCV) encodes the structural protein Core, which in addition to being the capsid subunit, participates in different mechanisms of HCV infection pathogenesis. Since HCV in vitro replication system has limitations, the use of viral vectors could be a useful tool to study the Core protein properties. To validate the Semliki Forest Virus (SFV) strategy in transduced HepG2 cells to study the HCV Core protein, the expression of green fluorescent protein (GFP) and Core protein expressions were detected 24 to 96 hours post-transduction in HepG2 cells transduced with rSFV. Core protein expression was lower than GFP expression in HepG2 cells. Since HCV Core protein can regulate the activity of the p53 gene, the transcriptional level of this gene was evaluated. A decrease in the level of p53 mRNA was observed in the cells after transduction, compared to the control cells. Although the cells transduced with rSFV-Core had the lowest level of p53 mRNA, the difference was not significant compared to cells transduced with rSFV-GFP. The results confirm that rSFV allows the transient expression of heterologous proteins in human hepatoma cell lines. Additional studies are needed to determine whether the decreased expression of Core may be due to the degradation of the viral protein.

Comparación de la Muestra Salival y de Nasofaringe en la Detección de SARS-CoV-2 mediante RT-PCR / Comparison Between Saliva and Nasopharyngeal Sample in Detection of SARS-CoV-2 by RT-PCR

RESUMEN: El coronavirus tipo 2, SARS-CoV-2, que causa la enfermedad denominada por la OMS como COVID-19, se ha expandido provocando una pandemia desde 2019, sin cura hasta la fecha. El mecanismo de transmisión del SARS-CoV-2 entre humanos es mediante las secreciones generadas durante la respiración y estornudos, presentándose con un período de incubación desde 1 a 14 días. Se describen fiebre, tos y astenia como los síntomas más habituales. El diagnóstico definitivo se logra a través de la correlación entre la presentación clínica y exámenes complementarios, pero en la actualidad, el método de muestreo de preferencia para el diagnóstico de SARS-CoV-2 es mediante una muestra de nasofaringe, en donde se analiza la presencia de material genético viral por medio de RT-PCR. Debido a las complicaciones en la obtención de la muestra, tanto para el personal sanitario como para el paciente, se ha implementado la muestra de saliva con finalidad diagnóstica, como un método que proporciona una detección rápida, simple y no invasiva de la infección viral. Esta alternativa diagnóstica podría entregar información respecto a la patogenia de la enfermedad, permitiendo el manejo y control de pacientes positivos. El siguiente artículo, tiene por objetivo realizar una comparación entre las tomas de muestra de saliva y de nasofaringe para el diagnóstico de SARS-CoV-2, mediante la prueba de reacción en cadena de la polimerasa con transcriptasa inversa (RT-PCR).

SUMMARY: The type 2 coronavirus, SARS-CoV-2, named by the WHO like COVID-19, has expanded causing a pandemic since 2019, with no cure to date. The mechanism of transmission of SARS-CoV-2 between humans is through secretions generated during breathing and sneezing, presenting with an incubation period range from 1 - 14 days. Fever, cough, and fatigue are described as the most common symptoms. The definitive diagnosis is achieved through the correlation between the clinical presentation and the complementary exams, but at present, the preferred sampling method for the diagnosis of SARS-CoV-2 is through a nasopharyngeal swab specimen, where it is analyzed the presence of viral genetic material by the RT-PCR. Due to the complications in obtaining the sample, both for health personnel and for the patient, the saliva sample has been implemented, as a method that provides rapid, simple and non-invasive detection of viral infection. This diagnostic alternative could provide information on the pathogenesis of the disease, the management and control of positive patients. The following article aims to make a comparison between the saliva and nasopharyngeal samples taken for the diagnosis of SARS-CoV-2, using the reverse transcription polymerase chain reaction test (RT-PCR).

Infección por el virus de la hepatitis delta / Hepatitis delta virus infection

El virus de la hepatitis delta (VHD) es un virus satélite del virus de la hepatitis B (VHB), dado que requiere el antígeno de superficie del VHB (HBsAg) para la producción de partículas virales infecciosas. Se han caracterizado ocho genotipos del VHD, con una distribución geográfica relacionada con la prevalencia de la infección por VHB. Se estima que aproximadamente el 5% de los pacientes con infección crónica por VHB también están infectados con VHD. Se han descrito dos tipos de infección: la coinfección simultánea por VHB y VHD, y la superinfección con VHD en un paciente previamente infectado por VHB, esta última asociada a una mayor morbilidad y mortalidad por falla hepática aguda. La infección se diagnostica en nuestro medio con la determinación de IgM contra el VHD, acompañada idealmente de la carga viral. Aunque el tratamiento de elección es la terapia con interferón alfa pegilado, en el momento se están evaluando otros medicamentos antivirales en ensayos clínicos, con resultados alentadores, teniendo en cuenta el efecto observado en la carga viral del VHD y/o del VHB en los pacientes. La presente revisión tiene como objetivo incluir temas como la biología del virus, la epidemiología, las características clínicas, el diagnóstico y el tratamiento en la infección por VHD.

Hepatitis delta virus (HDV) is a satellite virus of hepatitis B virus (HBV), as it requires the HBV surface antigen (HBsAg) for the production of infectious viral particles. Eight HDV genotypes have been characterized with a geographic distribution associated with the prevalence of HBV infection. It is estimated that approximately 5% of patients with chronic HBV infection are also infected with HDV. Two types of infection have been described: coinfection, by simultaneously contracting HBV and HDV infection, and superinfection, by contracting HDV when chronically infected with HBV, the latter associated with increased morbidity and mortality from acute liver failure. Anti-HDV IgM is used to diagnose the infection, ideally together with the detection of HDV-RNA. Although the treatment of choice is pegylated interferon alpha, other antiviral drugs are currently being evaluated in clinical trials, with encouraging results, in terms of their effect on HDV and/or HBV viral load in patients. This review aims to include topics such as virus biology, epidemiology, clinical manifestations, diagnosis, and treatment in HDV infection.

Mutación R249S TP53 en pacientes con cirrosis y carcinoma hepatocelular en un hospital de Medellín / TP53 R249S mutation in patients with cirrhosis and hepatocellular carcinoma in a hospital at Medellin

Resumen Introducción: la exposición dietaria a la aflatoxina es un factor de riesgo para carcinoma hepatocelular, el cáncer primario de hígado más frecuente. Esta asociación se estableció gracias a la evidencia in vitro e in vivo de la relación entre la exposición a la aflatoxina B1 y la transversión G→T en el codón 249 del gen TP53, así como evidencia de la sinergia entre la aflatoxina y la infección crónica por virus de la hepatitis B. Métodos: se determinó la frecuencia de la mutación R249S del gen TP53 en 30 pacientes con diagnóstico de cirrosis y/o carcinoma hepatocelular quienes fueron sometidos a trasplante hepático en un hospital en Medellín, Colombia. Se extrajo ADN a partir de las muestras de explante hepático, se amplificó el fragmento de interés y se detectó la mutación por polimorfismos de longitud de fragmentos de restricción. Resultados: se encontró la mutación R249S en una de las 30 muestras analizadas (3,33 %) y se determinó, por medio de marcadores serológicos, infección por el virus de la hepatitis B en dos casos (6,67 %). No se encontró simultáneamente la mutación y la presencia de los marcadores de infección por virus de la hepatitis B. Conclusión: los resultados sugieren una baja exposición dietaria con aflatoxina B1 en la población de estudio. Sin embargo, es importante tener en cuenta la regulación de los límites permisibles de aflatoxina B1 y la inclusión en el diagnóstico diferencial de carcinoma hepatocelular, dada la heterogeneidad de las condiciones de la población en diferentes regiones del país.

Abstract Introduction: The dietary exposure to aflatoxin is a risk factor of hepatocellular carcinoma, the most frequent primary liver cancer. This risk factor was identified after in vivo and in vitro evidence of the relation between exposure to aflatoxin B1 and transversion G → T at 249 codon of the TP53 gene; as well as evidence of the synergy between hepatitis B virus chronic infection. Methods: the frequency of the R249S mutation of the TP53 gene was determined in 30 cases of cirrhosis and/or hepatocellular carcinoma, with liver transplantation in the hepatology unit of a hospital in Medellín, Colombia. DNA was extracted from the liver explant samples; the sequence of interest was amplified, and the mutation was detected by restriction fragment length polymorphisms. Results: the R249S mutation was found in 1 of the 30 samples analyzed (3.33 %); and hepatitis B virus infection was detected by serological markers in 2 of the 30 cases (6.67 %). We did not find the mutation and the presence of hepatitis B virus infection markers at the same time in any of the samples. Conclusion: The results suggest a low dietary exposure with aflatoxin B1 in the study population. However, it is important to take into consideration the regulation of the permissible limits of aflatoxin B1 and the inclusion in the differential diagnosis of hepatocellular carcinoma, given the heterogeneity of the conditions of the population in different regions of the country.