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The Evolution of COVID-19 Diagnostics
Published in Debmalya Barh, Kenneth Lundstrom, COVID-19, 2022
Praveen Rai, Ballamoole Krishna Kumar, Deekshit Vijaya Kumar, Prashant Kumar, Anoop Kumar, Shashi Kumar Shetty, Biswajit Maiti
SARS-CoV-2, initially named as 2019-nCoV, quickly spread across international borders, infecting people in a number of countries, and prompting the World Health Organization (WHO) to declare SARS-CoV-2 infection as “a very high-risk global pandemic” [2]. As of May 21, 2021, 166,492,036 cases, including 3,458,041 deaths caused by COVID-19 have been registered worldwide, with a case fatality rate of 2.05%. Transmission of SARS-CoV-2 occurs primarily via respiratory droplets or aerosols (<5 μm) exhaled by an infected individual [3]. The virus can also be transmitted to a healthy individual via fomites carrying the virus, or by direct contact between an infected and a healthy individual. The incubation period for SARS-CoV-2 ranges from two to fourteen days with a median incubation period of 5–6 days, but an infected individual starts shedding the virus before the onset of symptoms or even if he or she is asymptomatic. Individuals infected with SARS-CoV-2 may be an asymptomatic carrier or may exhibit mild, moderate or severe acute respiratory syndrome distress (ARDS). The patients usually show symptoms such as a high fever above 39°C (102°F), headache, dry cough, sore throat, chest congestion, chest pain, shortness of breath, loose motions, runny nose, redness in eyes, pneumonia etc. In severe cases, the patients may show a respiratory rate above 30/min, oxygen saturation in blood below 95% and in this critical stage, severe pneumonia, septic shock, respiratory failure, cardiac arrest and multiple organ failures, leading to the death of the individual [4]. Health complications have also been observed in cases of asymptomatic infections, where the patients show relatively normal lung function without dyspnea, but with low blood oxygen saturation level, a condition referred to as ‘silent hypoxia’ and indicates severe respiratory failure, which may lead to the sudden death of the patient [5].
COVID-19 clinical phenotypes and short-term outcomes: differences between the first and the second wave of pandemic in Italy
Published in Expert Review of Respiratory Medicine, 2021
Andrea Portacci, Giovanna Elisiana Carpagnano, Maria Grazia Tummolo, Carla Santomasi, Lavinia Palma, Domenico Fasano, Emanuela Resta, Madia Lozupone, Vincenzo Solfrizzi, Francesco Panza, Onofrio Resta
Regarding symptoms, patients in the first wave showed more frequent early dyspnea and respiratory fatigue within the first 5 days of the disease onset. Despite this finding, no differences between the PaO2/FiO2 averages were found. This can be explained by considering that only patients with moderate-to-severe hypoxemia were hospitalized in our intermediate RICU, regardless of symptoms at the admission. Moreover, patients in the second wave were often hospitalized in the absence of dyspnea but with the evidence of a ‘silent hypoxia’. In contrast, first wave patients showed similar hypoxemia when respiratory fatigue and tachypnea were already present. Dyspnea in COVID-19 patients is a marker of disease severity [20]. In fact, early dyspnea may often precede the sudden worsening of respiratory exchanges. In addition, late finding of the silent hypoxia can lead to worse prognosis in COVID-19 disease [21]. In these patients without dyspnea, early hospitalization allowed identifying silent hypoxia before a worsening of respiratory dynamics, with a positive impact on the course of the disease.
Gavage approach to oxygen supplementation with oxygen therapeutic Ox66™ in a hypoventilation rodent model of respiratory distress
Published in Artificial Cells, Nanomedicine, and Biotechnology, 2021
William H. Nugent, Danuel A. Carr, Rosa MacBryde, Erica D. Bruce, Bjorn K. Song
Another potential benefit of gut oxygenation comes from hypoxaemia leading to sepsis-induced multi-organ failure as a cause of death in ARDS [34]. The catalyst is gut ischaemia [6]. As blood oximetry does not always indicate deeper tissue hypoxia—shown in the setting of hypovolemic anaemia [35]—a situation of “silent hypoxia” can develop in ARDS, which concentrates in the sensitive gastrointestinal tract. In response, the intestinal epithelium—barrier protecting the sterile self from the microbial-laden gut lumen—breaks down and releases an enormous endotoxin load into the body leading to sepsis [36]. Previous research has shown improved mesenteric oxygenation following ingestion of Ox66™ [18], an ex vivo digestion study simulating residence time from mouth through the intestine showed the efficacy of Ox66™ post- passage through saliva and gut juices (data not shown), in addition to this study’s finding of effective peripheral oxygen delivery through ingestion. While the metabolic situation of tissues and organs is multivariate and highly dependent on blood flow, there is evidence for an oxygen gradient stemming from the digestive tract. Under conditions where hypoxia concentrates in the intestinal barrier, oral oxygen supplementation may have a disproportionately large bulwarking effect compared with systemic changes and stave off sepsis.
Increased expression of hypoxia-induced factor 1α mRNA and its related genes in myeloid blood cells from critically ill COVID-19 patients
Published in Annals of Medicine, 2021
Keiko Taniguchi-Ponciano, Eduardo Vadillo, Héctor Mayani, César Raúl Gonzalez-Bonilla, Javier Torres, Abraham Majluf, Guillermo Flores-Padilla, Niels Wacher-Rodarte, Juan Carlos Galan, Eduardo Ferat-Osorio, Francisco Blanco-Favela, Constantino Lopez-Macias, Aldo Ferreira-Hermosillo, Claudia Ramirez-Renteria, Eduardo Peña-Martínez, Gloria Silva-Román, Sandra Vela-Patiño, Carlos Mata-Lozano, Roberto Carvente-Garcia, Lourdes Basurto-Acevedo, Renata Saucedo, Patricia Piña-Sanchez, Antonieta Chavez-Gonzalez, Daniel Marrero-Rodríguez, Moisés Mercado
Hypoxaemia, defined as a decrease in the partial pressure of oxygen is an ominous sign of COVID-19, and it is usually an indicator of disease severity [8,9]. An oxygen saturation above 90% is associated with better outcomes [10]. Over 80% of COVID-19 patients in the intensive care unit have severe hypoxaemia [11]. A kind of “silent hypoxia” in which COVID-19 patients deteriorate rapidly without warning and develop respiratory failure has been described [12]. Hypoxia indicates an imbalance of oxygen delivery to tissues and leads to compromised function, which is quantitatively related to organ, tissue and even cell type. The hypoxia-inducible factors (HIF) are considered master regulators of oxygen homeostasis and are oxygen level sensitive [13,14]. HIF1α is a heterodimeric transcription factor that bind to hypoxia response elements, which participates through the regulation of the expression of several genes in numerous cellular events such as O2 sensing, glucose metabolism, lipid metabolism, angiogenesis and other aspects of endothelial biology [14]. Currently, there is scarce information regarding the expression of HIF in patients with severe COVID-19 and its potential involvement in the immunopathogenesis of this condition. Therefore, in the present work we carried out scRNAseq to identify the cell populations present in critically ill COVID-19 patients and to determine the expression of hypoxia-induced factor 1α (HIF1α) and its related genes.