Gastrointestinal manifestations of COVID-19 in a Colombian population. A cross-sectional study

Introduction: gastrointestinal involvement in COVID-19 occurs in approximately 20% of patients and may include nausea, vomiting, abdominal pain, diarrhea or abnormal liver function tests. In our country, the characteristics of gastrointestinal involvement in COVID-19 patients have not been studied. Objectives: to determine the prevalence of gastrointestinal and liver involvement in patients with COVID-19 treated at two hospitals in Bogotá, Colombia. To determine the association between COVID-19 gastrointestinal involvement and length of hospital stay, severity and mortality. Design and methodology: a cross-sectional study carried out at two hospitals in a hospital subnetwork in Bogotá, Colombia from February 2020 to March 2021. Results: a total of 1,176 patients with a positive reverse transcription polymerase chain reaction (RT-PCR) were included. Gastrointestinal manifestations occurred in 50% (95%CI 47-52%), with the most frequent being diarrhea in 18.4%, odynophagia in 17.6%, anorexia in 14.7% and abdominal pain in 8.8%. An association was found between diarrhea during hospitalization and prolonged hospitalization (OR 1.93 95%CI 1.19-3.13), and between gastrointestinal bleeding on admission and death (OR 3.13, 95%CI 1.1-9.1), among others. Abnormal liver function tests occurred in 46% (95%CI 43-49%) and were more frequent in patients with severe disease and those who died. Conclusions: the prevalence of gastrointestinal manifestations in patients with COVID-19 was 50%. Diarrhea was associated with a longer hospital stay, and gastrointestinal bleeding was associated with respiratory failure and death. Forty-six percent of patients had abnormal liver function tests, with elevated transaminases being the most frequent. Elevated aspartate transaminase (AST) on admission was associated with greater mortality. (Acta Med Colomb 2022; 48. DOI:https://doi.org/10.36104/amc.2023.2729).

Más allá de las moléculas Lo que los clínicos desconocen: acortando brechas / Filling the gap: Beyond molecules What clinicians ignore

Para acortar la brecha entre lo molecular y la clínica, el personal de atención médica debe tener un conocimiento básico de los mecanismos moleculares que gobiernan la identidad celular, mediante la activación selectiva de genes. La expresión diferencial de genes permite a las células sintetizar las proteínas requeridas para cumplir con sus funciones biológicas, y ello posibilita a las células responder a estímulos internos y externos. Para esto se debe tener primero acceso a los genes que codifican las proteínas, determinando el fenotipo celular. Modificaciones en la estructura de la cromatina permiten a la maquinaria transcripcional tener acceso a secuencias de ADN. El ADN es transcripto en ARNm, que sufre diversas modificaciones antes de salir del núcleo para ser traducido en una proteína en el citoplasma. Cualquier desregulación en alguno de los procesos asociados se presenta como una patología. A inicios del siglo XXI se reportó la secuenciación del genoma humano, y sorprendentemente uno de los principales hallazgos fue que solo un 2% de la secuencia codifica para proteínas, lo cual dejó un interrogante sobre cómo funcionan y se regulan los procesos genéticos que llevan a la identidad celular. Desde entonces las investigaciones han permitido utilizar los principios que rigen estos procesos para ampliar el conocimiento de los mecanismos asociados a enfermedades. Gracias a estos avances, se ha buscado determinar aplicaciones clínicas dirigidas a los procesos involucrados en la expresión génica diferencial, lograr una mejor comprensión sobre los procesos patológicos de la enfermedad y desarrollar herramientas diagnósticas.

To narrow the gap between the bench and the clinic, healthcare personnel should have a basic understanding of molecular mechanisms ruling cell identity, since it establishes the key differences between health and disease states. Differential gene expression allows for protein synthesis required for the cell's biological function. In this process genes are selected from the entire genome to meet the cell's biological functioning and respond to internal and external stimuli. To this end, first the chromatin must be remodeled for the transcriptional machinery to gain access to DNA sequences coding for particular genes. DNA can then be transcribed into mRNA, followed by different processes leading to mature mRNA leaving the nucleus for protein synthesis in the cytoplasm. Any dysregulation in these processes results in disease. In the beginning of this millennium the human genome project sequenced the whole genome. Surprisingly, one of the main findings was only 2% of the genome represented protein coding sequences, which raised the question about the remainder of the genome and cell identity. Based on principles derived from the human genome project many investigations have shed light on mechanisms associated with disease. Thanks to advancements in differential gene expression, researchers are seeking for a better understanding in pathological processes associated with disease and the development of diagnostic tools.

Production and partial characterization of polygalacturonases produced by thermophilic Monascus sp N8 and by thermotolerant Aspergillus sp N12 on solid-state fermentation

Polygalacturonases production by newly isolated Monascus sp N8 and Aspergillus sp N12 strains was carried out in solid-state fermentation using mixtures of wheat bran, sugar cane bagasse and orange bagasse as carbon sources. The maximal activity values of exo-polygalacturonases (exo-Pg) from Monascus sp and Aspergillus sp were obtained using wheat bran/sugar cane bagasse/orange bagasse mixture (6.6 U/mL) and wheat bran/orange bagasse mixture (10 U/mL), respectively. Enzyme production by both strains was higher at 45°C after 72 h and 1.6 U/mL at 50°C after 120 h. Endo-polygalacturonase (endo-Pg) production was higher in wheat bran/orange bagasse mixture and was not affected by temperature of incubation for both fungi. Endo-Pg production by Monascus was 1.8 U/mL at 45°C and 50°C, after 72. Similar values were obtained in Aspergillus sp culture, 1.9 U/mL at 45°C and 1.8 U/mL at 50°C. Exo-Pg from both strains showed optimum activity at pH 5.5. Maximal activity was determined at 60°C for enzyme from Monascus sp and 50°C for that produced by Aspergillus sp. Exo-Pg from Monascus sp was stable at pH range 4.5-6.0 whereas that from Aspergillus sp enzyme was stable at pH 4.0. Both enzymes showed stability when incubated at 50°C for 1 h, in absence of substrate.

A produção de poligalacturonases pelas linhagens fúngicas recentemente isoladas, Monascus sp N8 e Aspergillus sp N12, foi estudada através de fermentação em estado sólido usando como substratos misturas de farelo de trigo, bagaço da cana-de-açúcar e bagaço de laranja. A atividade máxima de exo-Pg produzida por Monascus sp (6,6 U/mL) foi obtida quando o meio de cultivo utilizado continha mistura de farelo de trigo, bagaço da cana-de-açúcar e bagaço de laranja (1:1:1), enquanto que Aspergillus sp produziu maior quantidade da enzima (10 U/mL) em meio de farelo de trigo e bagaço de laranja. A maior produção de exo-Pg foi obtida através de incubação das culturas a 45°C quando comparadas àquelas incubadas a 50°C. A produção de endo-poligalacturonase (endo-Pg) pelas duas linhagens não foi afetada pela temperatura de incubação. A atividade de endo-Pg em meio de cultura Monascus sp foi 1.8 U/mL a 45°C em 72 hs de fermentação e 1,6 U/mL a 50°C em 120 hs de fermentação nas mesmas condições. Valores semelhantes foram obtidos pelo cultivo de Aspergillus sp com 1.9 U/mL a 45°C a 1.8 U/mL at 50°C. As exo-poligalacturonases produzidas por ambas as linhagens mostraram maiores atividades em pH 5,5. Enzimas de Monascus sp foi mais ativa a 60°C e a de Aspergillus sp, a 50°C. A exo-Pg produzida por Monascus sp foi estável em valores de pH entre 4,5-6,0, enquanto a de Aspergillus sp foi estável somente em pH 4,0. Ambas as enzimas mostraram-se estáveis por 1 hora a 50°C, quando incubadas em ausência de substrato.

Pectinase production by fungal strains in solid-state fermentation using agro-industrial bioproduct

A produção de pectina liase e poligalacturonase por linhagens de fungos filamentosos isoladas, foi estudada através de fermentação em estado sólido utilizando subprodutos agro-industriais. Os fungos Moniliella sp SB9 e Penicillium sp EGC5 produziram consideráveis quantidades de PG e PL em substrato composto por mistura de bagaço de laranja, bagaço de cana de açúcar e farelo de trigo (1:1:1). As enzimas PG e PL, produzidas por Moniliella sp, apresentaram atividades ótimas em pH de 4,5 e 10,0 e em temperaturas de 55°C e 45°C, respectivamente. As mesmas enzimas, produzidas por Penicillium sp apresentaram atividades ótimas em pH 4,5-5,9 e 9,0 e 40°C, respectivamente.