Boletín que incluye información científica sobre el COVID-19, incluye artículos científicos y artículos preprint actualizados al 01 de Julio de 2020.

Boletín que incluye información científica sobre el COVID-19, incluye artículos científicos y artículos preprint actualizados al 02 de Julio de 2020.

Boletín que incluye información científica sobre el COVID-19, incluye artículos científicos y artículos preprint actualizados al 17 de Junio de 2020.

Syfte: Syftet med denna litteraturstudie var att belysa vilka okulära och neurooftalmiska manifestationer Covid-19 (SARS-CoV-2) kan orsaka. Ett sekundärt syfte var dessutom att lyfta fram de direkta och indirekta symtom och problem som en optiker bör vara medveten om vid undersökning av patienter som har drabbats av en SARS‑CoV‑2-infektion. Metod: Litteraturstudien grundar sig i sökningar på databaserna PubMed och Web of Science. Sökningarna genomfördes mellan 2022-03-21 och 2022‑03‑29. Inklusionskriterier var att studierna fanns tillgängliga i fulltext, språket var på engelska eller svenska och var publicerade från januari 2020 till mars 2022. Reviewartiklar och fallstudier där enstaka individer (n≤8) undersöktes exkluderades. Studier som inte uppfyllde kraven om relevant innehåll till vårt syfte exkluderades.  Resultat: Både okulär och neurooftalmisk påverkan kan ses till följd av Covid-19 samt att prevalensen av påverkan kan variera. Vanligt förekommande okulära manifestationer var bland annat konjunktivit, ökat tårflöde och fotofobi. Vanligt förekommande neurooftalmiska manifestationer var bland annat onormala ögonrörelser, huvudvärk och yrsel.  Slutsats: Covid-19 kan leda till okulär, neurooftalmisk och indirekt påverkan. Det är en ny sjukdom och därför krävs ytterligare forskning. Optiker bör vara medvetna om vilka okulära och neurooftalmiska manifestationer som kan förknippas med Covid-19 samt hur det går att hjälpa dessa patienter på bästa sätt. Vanligt förekommande manifestationer inkluderar konjunktivit och förändringar i ögonrörelser.

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El COVID-19 causado por el SARS-CoV-2 ha puesto en peligro la vida de la población mundial. Pacientes llegaron a padecer fases críticas conllevándolos al internamiento en Unidad de Cuidados Intensivos y a procesos de coagulopatías como trombosis venosa profunda, coagulación intravascular diseminada, embolia pulmonar. El valor del dímero D elevado al ingreso o durante el progreso de la enfermedad se han relacionado con un mayor riesgo de mortalidad en pacientes con COVID-19 en comparación con los sobrevivientes. COVID-19 caused by SAR-CoV-2 has been life-threating in worldwide. Patients came to suffer critical phases leading to admission to the Intensive Care Unit and coagulopathy processes such as deep vein thrombosis, disseminated intravascular coagulation, pulmonary embolism. Elevated D-dimer values at admission or during disease progression have been associated with an increased risk of mortality in COVID-19 patients compared to survivors.

<p>Loop-mediated Isothermal Amplification (LAMP) is a promising technology to address diagnostic and surveillance testing during public health crises, such as the current COVID-19 pandemic; however, primer design and assay optimization remain a barrier to enabling rapid deployment of assays based on LAMP. Herein, we introduce a design and screening process that allows for strategic determination of optimally performing primer sets and standardized assay conditions which enable execution of LAMP at point-of-care (POC) settings using complex human samples such as saliva. A total of 20 primer sets targeting the N, E, RdRP, and orf1ab genes of the SARS-CoV-2 were designed, screened, and selected based on performance metrics such as reaction time, sensitivity, and specificity. Of these 20 primer sets, only two primer sets (orf1ab.2 and orf1ab.4) proved to be viable for use in the final assay. Colorimetric RT-LAMP of the selected primer set, orf1ab.2 was shown to produce a distinct color change in contrived samples containing heat-inactivated SARS-CoV-2 in 5% saliva. The limit of detection of our assay using primer set orf1ab.2 was determined to be 1000 copies/µL of saliva collected. Furthermore, methods are introduced which allow for the high-throughput design of LAMP primers using standard software tools and the <i>in-silico</i> performance of LAMP primer sets. </p>

The outbreak of infectious diseases across the world results in huge disasters for public health. Rapid and effective diagnostic methods are crucial for disease identification and transmission control. Since first identified in late 2019, the pandemic of COVID-19 caused by the SARS-CoV-2 virus resulted in unprecedented catastrophe globally. To control the further spread of COVID-19, there is an urgent need for rapid, accurate, cost-effective, and efficient diagnostics. Recently, many CRISPR-based diagnostics have been developed by coupling isothermal amplification methods with Cas proteinmediated nucleic acid detection. Compared with conventional methods like RT-qPCR, CRISPR-based assays are more cost-effective and efficient without sacrificing sensitivity and specificity. Here, I developed a Cas13-based assay for SARS-CoV-2 detection with a novel compact Cas13b protein. In this assay, the Cas13 detection is combined with RT-LAMP, achieving the detection of viral RNA as low as 4 copies/μl. By utilizing a simple LED-based visualizer (P51™) instead of a plate reader, the detection result can be visualized directly without using sophisticated instruments. The compact Cas13b-mediated viral detection together with P51™-based visualization enable rapid, sensitive, and portable diagnostics for SARS-CoV-2, showing great potential in application to point-of-care testing.

Objetivos: Determinar los hallazgos tomográficos pulmonares asociados a severidad y mortalidad en pacientes con la COVID-19 del Hospital Nacional Edgardo Rebagliati Martins (HNERM), y proponer puntos de corte para una puntuación tomográfica de severidad (PTS). Materiales y métodos: Estudio de cohorte retrospectivo en 254 pacientes con la COVID-19 que contaban con tomografía de tórax clasificada según severidad clínica. Se realizó un análisis multivariado mediante regresión logística para determinar asociación con la severidad clínica, un análisis de regresión de Cox para evaluar mortalidad, y curvas ROC para evaluar la PTS. Resultados: Los hallazgos tomográficos asociados a severidad clínica fueron el patrón difuso de las lesiones (OR: 3,23, IC 95%: 1,46-7,14), patrón en «empedrado» (OR: 2,48; IC 95%: 1,08-5,68) y mayor valor en la PTS (OR: 1,73; IC 95%: 1,49-2,02). Los hallazgos asociados a mortalidad fueron el patrón en «empedrado» (HR: 1,78; IC 95%: 1,03-3,06) y mayor valor en la PTS (HR:1,33; IC 95%: 1,20-1,48). Un valor de 7 en la PTS tuvo una sensibilidad de 94,4% y especificidad de 100% para identificar casos moderados y un valor de 13 tuvo una sensibilidad de 84,9% y una especificidad de 70,6% para casos severos. Conclusiones: El patrón difuso de las lesiones se asoció a una mayor severidad clínica. El patrón en «empedrado» y un mayor valor en la PTS se asociaron a mayor severidad clínica y a mortalidad. Se proponen los valores de 7 y 13 como puntos de corte de la PTS para identificar casos moderados y severos.

How do bacteria grow and replicate rapidly? How do viruses and phages adapt to their host environments? Bacteria require efficient translation to grow and replicate rapidly, and translation is often rate-limited by initiation. A feature that is conserved across bacterial lineages is the Shine-Dalgarno (SD) sequence at the mRNA 5’ UTR, which pairs with the anti-SD sequence located at the 3’ end of mature 16S rRNA. Nonetheless, much about this interaction remains unclear. Chapter 2 reveals evolutionary differences between Cyanobacteria and chloroplast translation initiation using a new model (DtoStart) that better define optimal SD sequence and an RNA-Seq-based approach that reliably characterize the 3’ end of mature 16S rRNAs. Efficacy of translation elongation depends much on tRNA-mediated codon adaptation. In Escherichia coli, selection favours major codons because they are rapidly decoded by abundantly available cognate tRNAs. Nonetheless, the degree codon bias correlates with tRNA availability is unclear in many bacterial species because tRNA abundance is often inadequately approximated by gene copy numbers. To better understand tRNA-mediated codon bias, Chapter 3 describes an RNA-Seq-based approach to robustly quantify tRNA abundance. Finally, Chapter 4 evaluates the degree optimal translation initiation and elongation signals affect ribosome dynamics. The emergence of COVID-19 pandemic poses a serious global health emergency. To establish infection during cell entry, the coronavirus Spike protein binds to the host ACE2 receptor, and a high binding potential between these two players is key to infectivity. While SARS-CoV-2 transmits efficiently in humans, it is less clear which other mammals are at risk of being infected. Chapter 5 investigates the host range of SARS-CoV-2 through comparative sequence analyses at the ACE2 receptors and the Spike proteins. As obligate parasites, coronaviruses regularly infect host tissues that express antiviral proteins (AVPs) in abundance and must evade or adapt to the host cellular environments post-entry. Two AVPs that shape viral genomes are ZAP that binds to CpG dinucleotides to facilitate viral transcript degradation, and APOBEC3 which deaminates C into U leading to dysfunctional transcripts. Chapter 6 shows that coronavirus genomes are CpG deficient to evade ZAP and are subjected to constant C to U deamination by APOBEC3. This thesis examines two key concepts of microbial genome evolution: 1) coevolution between gene features and the translation machinery in bacteria, and 2) adaptation of viruses to the hosts they infect. Chapters 2, 3, and 4 are aimed at improving our understanding in bacterial gene expression in the applications of transgenic biosynthesis and phage therapy. Chapters 5 and 6 are aimed at improving our understanding in the origin and evolution of SARS-CoV-2 and our ability to control the spread of infection.