Infección por el virus de la hepatitis A: epidemiología y diversidad genética

ABSTRACT: Hepatitis A virus infection is a global public health problem. The virus has a wide range of distribution and it is the main cause of acute hepatitis transmitted by the enteric route in Latin America. The viral particle is stable under environmental conditions and conserves its infectivity for several weeks, enabling its transmission by contaminated water and food. Worldwide, different epidemiological patterns have been identified, which may change over time by modification of social and economic variables in the population such as vaccination and the improvement of hygiene and primary health conditions. This leaves new populations susceptible to infection. In Latin America the circulation of genotype I and subgenotypes A and B has been described, but more research is needed to provide the knowledge needed to manage the prevention and control plans for the worldwide reduction of the prevalence of infection. For this paper, a literature review was performed on the SciELO, PubMed and ScienceDirect databases under the search terms "Hepatitis A", "Epidemiology," "Seroprevalence" and "Infection." From the results obtained, only papers published in English and Spanish to describe epidemiological and molecular studies of interest in Latin America were included. Key words: Epidemiologia, Hepatite, Saúde Pública, Vírus da Hepatite A.RESUMEN: La infección por el virus de la hepatitis A es un problema global de salud pública. El virus está ampliamente distribuido y es la principal causa de hepatitis aguda de transmisión entérica en Latinoamérica. La partícula viral es estable en el medio ambiente y conserva su infectividad por varias semanas, lo que facilita su transmisión por agua y alimentos contaminados. Mundialmente se han descrito distintos patrones epidemiológicos, que pueden cambiar en el tiempo al modificarse variables socioeconómicas en la población como las condiciones sanitarias básicas y la vacunación. Esto deja al descubierto nuevas poblaciones susceptibles a la infección. En Latinoamérica se ha descrito la circulación del genotipo I y los subgenotipos A y B, pero se requieren más investigaciones que aporten el conocimiento necesario para gestionar planes de prevención y control para la disminución mundial de la prevalencia de la infección. Para este artículo se hizo una revisión de la literatura en las bases de datos SciELO, PubMed y ScienceDirect bajo los términos de búsqueda “Virus de la hepatitis A”, “Epidemiología”, “Seroprevalencia” e “Infección”. De los resultados obtenidos se incluyeron únicamente las publicaciones en inglés y español que describieran estudios epidemiológicos y moleculares de interés en Latinoamérica. Palabras clave: Epidemiología, Hepatitis, Salud Pública, Virus de la Hepatitis A

Reporte de un brote de infección por SARS-CoV-2 por transmisión aérea: evidencia epidemiológica y molecular

Introduction: It has been shown that the transmission of SARS-CoV-2 occurs mainly by air, and the risk of infection is greater in closed spaces. Objective: Describe the epidemiology, virology and molecular characterization of a COVID-19 outbreak at a closed vaccination point during the third wave of SARS-CoV-2 in Colombia. Materials and methods: Diagnostic tests, interviews, sampling, cell cultures and viral sequencing were carried out, the latter being molecular characterization and lineage identification. Results: Seven workers were positive for SARS-CoV-2; among these, 3 samples were analyzed, plus an additional sample belonging to the mother of the presumed index case; all samples were identified with lineage B.1.625, with a maximum of 2 nucleotides difference between them. Conclusions: Variant B.1.625 was identified as the cause of the COVID-19 outbreak, and a co-worker was also identified as the index case. Unexpectedly, attending a vaccination day became a risk factor for acquiring the infection.Introducción. Se ha demostrado que la transmisión de SARS-CoV-2 se da principalmente por vía aérea y el riesgo de infección es mayor en espacios cerrados con alta concentración de personas; este último factor se presentó en algunos de los puestos de vacunación de la ciudad de Medellín. Objetivo. Describir la epidemiología, virología y caracterización molecular de un brote de COVID-19 en un punto de vacunación cerrado durante la tercera ola de SARS-CoV-2 en Colombia. Materiales y métodos. Se realizaron test diagnósticos, entrevistas, toma de muestras, aislamiento viral y secuenciación genómica. Con esta última se realizó caracterización molecular e identificación de linaje. Resultados. Siete trabajadores fueron positivos para SARS-CoV-2, y de estos, tres muestras fueron secuenciadas, más una muestra adicional perteneciente a la madre del presunto caso índice. Todas las muestras fueron identificadas con el linaje B.1.625, con un máximo de 2 nucleótidos de diferencia entre ellas. Conclusiones. Se identificó la variante B.1.625 como la causante del brote de COVID-19, y también un compañero de trabajo fue identificado como el caso índice. De forma imprevista, asistir a una jornada de vacunación se convirtió en un factor de riesgo para adquirir la infección

Feasibility Study of a Proton Irradiation Facility for Radiobiological Measurements at an 18 MeV Cyclotron

A feasibility study of an experimental setup for the irradiation of biological samples at the cyclotron facility installed at the National Centre of Accelerators (Seville, Spain) is presented. This cyclotron, which counts on an external beam line for interdisciplinary research purposes, produces an 18 MeV proton beam, which is suitable for the irradiation of mono-layer cultures for the measurement of proton cell damages and Relative Biological Effectiveness (RBE) at energies below the beam nominal value. Measurements of this kind are of interest for proton therapy, since the variation of proton RBE at the distal edge of the Bragg curve may have implications in clinical proton therapy treatments. In the following, the characteristics of the beam line and the solutions implemented for the irradiation of biological samples are described. When dealing with the irradiation of cell cultures, low beam intensities and broad homogeneous irradiation fields are required, in order to assure that all the cells receive the same dose with a suitable dose rate. At the cyclotron, these constraints have been achieved by completely defocusing the beam, intercepting the beam path with tungsten scattering foils and varying the exit-window-to-sample distance. The properties of the proton beam thus obtained have been analysed and compared with Monte Carlo simulations. The results of this comparison, as well as the experimental measurement of the lateral dose profiles expected at the position of samples are presented. Meaningful dose rates of about 2–3 Gy/min have been obtained. Homogeneous lateral dose profiles, with maximum deviations of 5%, have been measured at a distance of approximately 50 cm in air from the exit window, placing a tungsten scattering foil of 200 μm in the beam path

Influence of Genetics on the Response to Omalizumab in Patients with Severe Uncontrolled Asthma with an Allergic Phenotype

Omalizumab is a monoclonal antibody indicated for the treatment of severe uncontrolled asthma with an allergic phenotype. Its effectiveness could be influenced by clinical variables and single nucleotide polymorphisms (SNPs) in one or more of the genes involved in the mechanism of action and process of response to omalizumab, and these could be used as predictive biomarkers of response. We conducted an observational retrospective cohort study that included patients with severe uncontrolled allergic asthma treated with omalizumab in a tertiary hospital. Satisfactory response after 12 months of treatment was defined as (1) Reduction 50% of exacerbations or no exacerbations, (2) Improvement of lung function 10% FEV1, and (3) Reduction 50% of OCS courses or no OCS. Polymorphisms in the FCER1A (rs2251746, rs2427837), FCER1B (rs1441586, rs573790, rs1054485, rs569108), C3 (rs2230199), FCGR2A (rs1801274), FCGR2B (rs3219018, rs1050501), FCGR3A (rs10127939, rs396991), IL1RL1 (rs1420101, rs17026974, rs1921622), and GATA2 (rs4857855) genes were analyzed by real-time polymerase chain reaction (PCR) using TaqMan probes. A total of 110 patients under treatment with omalizumab were recruited. After 12 months of treatment, the variables associated with a reduction in exacerbations were the absence of polyposis (odds ratio [OR] = 4.22; 95% confidence interval [CI] = 0.95–19.63), IL1RL1 rs17026974-AG (OR = 19.07; 95% CI = 1.27–547), and IL1RL1 rs17026974-GG (OR = 16.76; 95% CI = 1.22–438.76). Reduction in oral corticosteroids (OCS) was associated with age of starting omalizumab treatment (OR = 0.95; 95% CI = 0.91–0.99) and blood eosinophil levels > 300 cells/ L (OR = 2.93; 95% CI = 1.01–9.29). Improved lung function showed a relationship to the absence of chronic obstructive pulmonary disease (COPD) (OR = 12.16; 95% CI = 2.45–79.49), FCGR2B rs3219018-C (OR = 8.6; 95% CI = 1.12–117.15), GATA2 rs4857855-T (OR = 15.98; 95% CI = 1.52–519.57) and FCGR2A rs1801274-G (OR = 13.75; 95% CI = 2.14–142.68; AG vs. AA and OR = 7.46; 95% CI = 0.94–89.12; GG vs. AA). Meeting one response criterion was related to FCER1A rs2251746-TT (OR = 24; 95% CI = 0.77–804.57), meeting two to age of asthma diagnosis (OR = 0.93; 95% CI = 0.88–0.99), and meeting all three to body mass index (BMI) < 25 (OR = 14.23; 95% CI = 3.31–100.77) and C3 rs2230199-C (OR = 3; 95% CI = 1.01–9.92). The results of this study show the possible influence of the polymorphisms studied on the response to omalizumab and the clinical benefit that could be obtained by defining predictive biomarkers of treatment response.Instituto de Salud Carlos III (PT13/0010/0039)Biobank of the Hospital Universitario Virgen de las Nieves

Mutaciones del gen ARN ribosómico 23S de Helicobacter pylori asociadas con resistencia a claritromicina en pacientes atendidos en una unidad de endoscopia de Medellín, Colombia

Introduction: Clarithromycin is the first-line antibiotic for the treatment of Helicobacter pylori infection. Bacterial resistance is mainly due to the presence of specific mutations in the 23S ribosomal RNA (rRNA) gene.Objective: To determine the frequency of A2143G and A2142G specific mutations in the 23S rRNA gene associated with clarithromycin resistance of H. pylori in samples from patients with dyspeptic manifestations in Medellín, northwestern Colombia.Materials and methods: DNA was extracted from gastric biopsy samples of patients with dyspeptic manifestations seen at an endoscopy unit in Medellín between 2016 and 2017. PCR was performed to amplify the bacterial s and m vacA regions, and a region in the 23S rRNA gene. The presence of the A2142G and A2143G mutations was determined using the restriction fragment length polymorphism (RFLP) technique with the BbsI and BsaI enzymes, respectively.Results: The prevalence of infection was 44.2% (175/396), according to the histopathology report. The positive samples were analyzed and the three regions of the bacterial genome were amplified in 143 of the 175 samples. The A2143G and A2142G mutations were identified in 27 samples (18.8%, 27/143). The most frequent mutation was A2143G (81.5%, 22/27).Conclusions: We found a high prevalence of H. pylori mutations associated with clarithromycin resistance in the study population. Further studies are required to determine the bacterial resistance in the Colombian population in order to define first line and rescue treatments.Introducción. La claritromicina es el antibiótico de primera línea para el tratamiento de la infección por Helicobacter pylori. La resistencia bacteriana se produce principalmente por mutaciones puntuales del gen ARN ribosómico 23S (ARNr 23S).Objetivo. Determinar la frecuencia de las mutaciones puntuales A2143G y A2142G del gen ARNr 23S asociadas con la resistencia de H. pylori a la claritromicina en muestras de pacientes con manifestaciones dispépticas en Medellín, región noroccidental de Colombia.Materiales y métodos. Se extrajo ADN a partir de muestras de biopsia gástrica obtenidas de pacientes con manifestaciones dispépticas atendidos en una unidad de endoscopia entre el 2016 y el 2017. Mediante reacción en cadena de la polimerasa (PCR), se amplificaron las regiones s y m del gen vacA y una región del gen ARNr 23S bacteriano. La presencia de las mutaciones A2142G y A2143G se determinó por la técnica de polimorfismos de longitud de fragmentos de restricción (RFLP) con las enzimas BbsI y BsaI, respectivamente.Resultados. Se encontró una prevalencia de infección de 44,2 % (175/396), según el informe de histopatología. En 143 de estas 175 muestras positivas se amplificaron las tres regiones del genoma bacteriano. Se identificaron las mutaciones A2143G y A2142G en 27 muestras (18,8 %; 27/143), la mutación más frecuente fue la A2143G (81,5 %; 22/27).Conclusiones. Hubo una gran prevalencia de mutaciones asociadas con la resistencia de H. pylori a la claritromicina en la población de estudio. Se requieren estudios adicionales para establecer la resistencia bacteriana en la población colombiana y, así, determinar los tratamientos de primera línea y de rescate

Secreted Frizzled – Related Protein 4 and breast cancer

Introducción: el correcto funcionamiento y la supervivencia de la célula vienen mediados por multitud de procesos clave. El delicado equilibrio que se requiere entre dichos fenómenos hace que un error en los mecanismos de control desencadene el inicio de la carcinogénesis. Dentro de las rutas metabólicas encargadas de su regulación se encuentran las vías de señalización del Wnt. De esta forma, aquellas moléculas que intervengan en dichas vías presentarán un papel clave para el estudio de la patología, entre las que destaca secreted Frizzled – Related Protein 4 (sFRP4). Método: se ha llevado a cabo una búsqueda bibliográfica en bases de datos de referencia, como es el caso de Medline, Scopus o Web of Science. Resultados: a sFRP4 se le ha otorgado el papel de modulador negativo de las vías de Wnt debido a su capacidad de competir por los ligandos Wnt y evitar el inicio de dichas rutas. Por lo tanto, sFRP4 será esencial en el control del inicio y desarrollo del cáncer en aquellos tejidos donde se exprese la proteína, dentro de los que se considera el tejido mamario. Conclusiones: los recientes estudios acerca de la implicación de sFRP4 en el desarrollo de diversas patologías, justifican que la proteína haya captado la atención en los últimos años. De esta forma, se puede afirmar que sFRP4 presenta un interesante potencial como biomarcador en el tratamiento, diagnóstico y pronóstico del cáncer de mama, entre otras enfermedades.Introduction: cell’s correct functionality and surveillance are brokered by a wide range of essential proceedings. The delicate equilibrium required between those phenomenon means that an error in the control mechanisms provoke the carcinogenesis commencement. In those metabolic pathways in charge of controlling the mechanisms are found the Wnt signaling pathways. Therefore, molecules that interact with the pathways mentioned, where secreted Frizzled – Related Protein 4 is located, will play a key role in the pathology knowledge. Method: a bibliographic research has been done in referral databases, such as Medline and Scopus. Results: sFRP4 has been identified as a negative modulator of the Wnt signaling pathways. This is due to its capacity of competing for the Wnt ligands and avoiding the commencement of the pathways. Otherwise, sFRP4 is essential for the control of the cancer beginning and development in those tissues where the protein is expressed, being mammary tissues considered into them. Conclusions: recent studies about the implications of sFRP4 in the development of several pathologies justify that the protein had garnered attention in recent years. Furthermore, it can be affirmed that sFRP4 presents an interesting potential as biomarker in the breast cancer treatment, diagnosis and prognosis, among other pathologies

Types and Distribution of Bioactive Polyunsaturated Aldehydes in a Gradient from Mesotrophic to OligotrophicWaters in the Alborán Sea (Western Mediterranean)

Polyunsaturated aldehydes (PUAs) are bioactive molecules suggested as chemical defenses and infochemicals. In marine coastal habitats, diatoms reach high PUA production levels during bloom episodes. Two fractions of PUA can usually be analyzed: pPUA obtained via artificial breakage of collected phytoplankton cells and dissolved PUA already released to the environment (dPUA). In nature, resource supply arises as a main environmental controlling factor of PUA production. In this work, we monitored the vertical distribution and daily variation of pPUA associated with large-size phytoplankton and dPUA, at three sites located in the Alboran Sea from mesotrophic to oligotrophic waters. The results corroborate the presence of large-size PUA producers in oligotrophic and mesotrophic waters with a significant (58%-85%) diatom biomass. In addition to diatoms, significant correlations between pPUA production and dinoflagellate and silicoflagellate abundance were observed. 2E,4E/Z-Heptadienal was the most abundant aldehyde at the three sites with higher values (17.1 fg center dot cell(-1)) at the most oligotrophic site. 2E,4E/Z-Decadienal was the least abundant aldehyde, decreasing toward the oligotrophic site. For the first time, we describe the daily fluctuation of pPUA attributable to cellular physiological state and not exclusively to taxonomical composition. Our results demonstrate the persistence of threshold levels of dPUA deep in the water column, as well as the different chromatographic profiles of dPUA compared with pPUA. We propose different isomerization processes that alter the chemical structure of the released PUAs with unknown effects on their stability, biological function, and potential bioactivity

Polymorphisms in VDR, CYP27B1, CYP2R1, GC and CYP24A1 Genes as Biomarkers of Survival in Non-Small Cell Lung Cancer: A Systematic Review

The objective of this systematic review was to provide a compilation of all the literature available on the association between single-nucleotide polymorphisms (SNPs) in the genes involved in the metabolic pathway of vitamin D and overall survival (OS) and progression-free survival (PFS) in patients with non-small cell lung cancer (NSCLC). This systematic review was conducted in accordance with the PRISMA guidelines. It included all the literature published up to 1 November 2022 and was carried out in four databases (Medline [PubMed], Scopus,Web of Science, and Embase), using the PICO strategy, with relevant keywords related to the objective. The quality of the studies included was evaluated with an assessment tool derived from the Strengthening the Reporting of Genetic Association Studies (STREGA) statement. Six studies were included in this systematic review. Our findings showed that the BsmI (rs1544410), Cdx-2 (rs11568820), FokI (rs2228570), ApaI (rs7975232), TaqI (rs731236), rs4646536, rs6068816, rs7041, and rs10741657 SNPs in the genes that play a part in vitamin D synthesis (CYP2R1, CYP27B1), transport (GC), and metabolism (CYP24A1), as well as in the vitamin D receptor (VDR), are associated with OS and/or PFS in patients with NSCLC. The SNPs in VDR have been the most extensively analyzed. This systematic review summed up the available evidence concerning the association between 13 SNPs in the main genes involved in the vitamin D metabolic pathway and prognosis in NSCLC. It revealed that SNPs in the VDR, CYP27B1, CYP24A1, GC, and CYP2R1 genes could have an impact on survival in this disease. These findings suggest the identification of prognostic biomarkers in NSCLC patients. However, evidence remains sparse for each of the polymorphisms examined, so these findings should be treated with caution.The Virgen de las Nieves University Hospital Biobank was supported by grants co-funded by ERDF funds (EU) from the Instituto de Salud Carlos III (PT13/0010/0039)

Hepatitis C Virus Proteins Core and NS5A Are Highly Sensitive to Oxidative Stress-Induced Degradation after eIF2α/ATF4 Pathway Activation

Hepatitis C virus (HCV) infection is accompanied by increased oxidative stress and endoplasmic reticulum stress as a consequence of viral replication, production of viral proteins, and pro-inflammatory signals. To overcome the cellular stress, hepatocytes have developed several adaptive mechanisms like anti-oxidant response, activation of Unfolded Protein Response and autophagy to achieve cell survival. These adaptive mechanisms could both improve or inhibit viral replication, however, little is known in this regard. In this study, we investigate the mechanisms by which hepatocyte-like (Huh7) cells adapt to cellular stress in the context of HCV protein overexpression and oxidative stress. Huh7 cells stably expressing individual HCV (Core, NS3/4A and NS5A) proteins were treated with the superoxide anion donor menadione to induce oxidative stress. Production of reactive oxygen species and activation of caspase 3 were quantified. The activation of the eIF2α/ATF4 pathway and changes in the steady state levels of the autophagy-related proteins LC3 and p62 were determined either by quantitative polymerase chain reaction (qPCR) or Western blotting. Huh7 cells expressing Core or NS5A demonstrated reduced oxidative stress and apoptosis. In addition, phosphorylation of eIF2α and increased ATF4 and CHOP expression was observed with subsequent HCV Core and NS5A protein degradation. In line with these results, in liver biopsies from patients with hepatitis C, the expression of ATF4 and CHOP was confirmed. HCV Core and NS5A protein degradation was reversed by antioxidant treatment or silencing of the autophagy adaptor protein p62. We demonstrated that hepatocyte-like cells expressing HCV proteins and additionally exposed to oxidative stress adapt to cellular stress through eIF2a/ATF4 activation and selective degradation of HCV pro-oxidant proteins Core and NS5A. This selective degradation is dependent on p62 and results in increased resistance to apoptotic cell death induced by oxidative stress. This mechanism may provide a new key for the study of HCV pathology and lead to novel clinically applicable therapeutic interventions

Hepatitis C virus core or NS3/4A protein expression preconditions hepatocytes against oxidative stress and endoplasmic reticulum stress

OBJECTIVES: The occurrence of oxidative stress and endoplasmic reticulum (ER) stress in hepatitis C virus (HCV) infection has been demonstrated and play an important role in liver injury. During viral infection, hepatocytes must handle not only the replication of the virus, but also inflammatory signals generating oxidative stress and damage. Although several mechanisms exist to overcome cellular stress, little attention has been given to the adaptive response of hepatocytes during exposure to multiple noxious triggers.METHODS: In the present study, Huh-7 cells and hepatocytes expressing HCV Core or NS3/4A proteins, both inducers of oxidative and ER stress, were additionally challenged with the superoxide anion generator menadione to mimic external oxidative stress. The production of reactive oxygen species (ROS) as well as the response to oxidative stress and ER stress were investigated.RESULTS: We demonstrate that hepatocytes diminish oxidative stress through a reduction in ROS production, ER-stress markers (HSPA5 [GRP78], sXBP1) and apoptosis (caspase-3 activity) despite external oxidative stress. Interestingly, the level of the autophagy substrate protein p62 was downregulated together with HCV Core degradation, suggesting that hepatocytes can overcome excess oxidative stress through autophagic degradation of one of the stressors, thereby increasing cell survival. Duscussion: In conclusion, hepatocytes exposed to direct and indirect oxidative stress inducers are able to cope with cellular stress associated with viral hepatitis and thus promote cell survival.</p