Towards a Unified Understanding of Lithium Action in Basic Biology and its Significance for Applied Biology.

Lithium has literally been everywhere forever, since it is one of the three elements created in the Big Bang. Lithium concentration in rocks, soil, and fresh water is highly variable from place to place, and has varied widely in specific regions over evolutionary and geologic time. The biological effects of lithium are many and varied. Based on experiments in which animals are deprived of lithium, lithium is an essential nutrient. At the other extreme, at lithium ingestion sufficient to raise blood concentration significantly over 1 mM/, lithium is acutely toxic. There is no consensus regarding optimum levels of lithium intake for populations or individuals-with the single exception that lithium is a generally accepted first-line therapy for bipolar disorder, and specific dosage guidelines for sufferers of that condition are generally agreed on. Epidemiological evidence correlating various markers of social dysfunction and disease vs. lithium level in drinking water suggest benefits of moderately elevated lithium compared to average levels of lithium intake. In contrast to other biologically significant ions, lithium is unusual in not having its concentration in fluids of multicellular animals closely regulated. For hydrogen ions, sodium ions, potassium ions, calcium ions, chloride ions, and magnesium ions, blood and extracellular fluid concentrations are closely and necessarily regulated by systems of highly selective channels, and primary and secondary active transporters. Lithium, while having strong biological activity, is tolerated over body fluid concentrations ranging over many orders of magnitude. The lack of biological regulation of lithium appears due to lack of lithium-specific binding sites and selectivity filters. Rather lithium exerts its myriad physiological and biochemical effects by competing for macromolecular sites that are relatively specific for other cations, most especially for sodium and magnesium. This review will consider what is known about the nature of this competition and suggest using and extending this knowledge towards the goal of a unified understanding of lithium in biology and the application of that understanding in medicine and nutrition.

Reverse-Transcription Loop-Mediated Isothermal Amplification and alternative protocols for lower cost, large-scale COVID-19 testing: lessons from an emerging economy / Amplificación isotérmica mediada por bucle de transcripción inversa y protocolos alternativos para pruebas COVID-19 a gran escala y de bajo costo: lecciones de una economía emergente

Abstract Introduction: Most successful cases of COVID-19 pandemic mitigation and handling have relied on extensive reverse-transcription quantitative polymerase chain reaction (RT-qPCR). However, many emerging economies have struggled with current molecular testing demands due to economic, technical and technological constraints. Objective: To define a potential diagnostic protocol to increase testing capacity in current and post-pandemic conditions. Methods: We reviewed the literature, patents and commercial applications, for alternatives. Results: We found a good potential in saliva samples, viral inactivation and quick RNA extraction by heating; the use of an isothermal technology such as loop mediated isothermal amplification (LAMP) and naked eye test-result visualization by in-tube colorimetry or turbidity. Conclusions: Saliva samples with quick RNA extraction by heating and colorimetric LAMP are promising options for countries with economic and infrastructure limitations.

Resumen Introducción: La mayoría de los casos exitosos de mitigación y manejo de la pandemia de COVID-19 se han dado mediante pruebas basadas en la reacción en cadena de la polimerasa cuantitativa (RT-qPCR por sus siglas en inglés). Sin embargo, muchas economías emergentes han tenido problemas con las demandas actuales de pruebas moleculares debido a limitaciones económicas, técnicas y tecnológicas. Objetivo: Definir un protocolo de diagnóstico potencial para aumentar la capacidad de prueba en las condiciones actuales y posteriores a la pandemia. Métodos: Revisamos la literatura, las patentes y las aplicaciones comerciales, en busca de alternativas. Resultados: Encontramos un buen potencial en muestras de saliva, inactivación viral y extracción rápida de ARN por calentamiento; el uso de una tecnología isotérmica como la amplificación isotérmica mediada por horquillas (LAMP, por sus siglas en inglés) y la visualización del resultado de la prueba a simple vista mediante colorimetría o turbidez en el tubo. Conclusiones: Las muestras de saliva con extracción rápida de ARN por calentamiento y LAMP colorimétrico son opciones prometedoras para países con limitaciones económicas y de infraestructura.