Performance & clinical utility of oropharyngeal versus nasopharyngeal swabs in COVID-19.

Background & objectives: The oropharyngeal (OP) and nasopharyngeal (NP) swab samples are the most recommended clinical specimens for detecting SARS-CoV-2 in an individual through the quantitative real-time reverse-transcriptase-polymerase chain reaction (rRT-PCR) method. The primary objective of this study was to compare the performance of NP and OP swabs for the diagnosis of COVID-19 among 2250 concomitant samples (1125 NP + 1125 OP) using rRT-PCR test. Methods: This study was conducted at a tertiary care hospital in southern India. The study compared the specificity and efficacy of the two samples (NP & OP swabs) in 1125 individuals suspected having COVID-19 infection. The rRT-PCR values from all the samples were compared based on gender, age group and viral load. The differences between unmatched proportion and matched proportion were analysed. Agreement between the two methods was assessed using Kappa statistic. Absolute sensitivity, specificity, positive and negative predictive values (PPV and NPV) for OP and NP swabs were analysed. Results: The study identified a fair degree of agreement between OP and NP swabs in diagnosis of COVID-19 (kappa = 0.275, P <0.001). There was also a fair degree of agreement between NP and OP swabs irrespective of gender, age or duration of symptoms. NP swabs had better sensitivity and NPV as compared to OP swabs, however, specificity and PPV were 100 per cent for both. Interpretation & conclusions: The present study showed that both OP and NP swabs had similar sensitivity and specificity for predicting the presence of SARS-CoV-2.

The Synergistic Combination of Everolimus and Paroxetine Exerts Post-ischemic Neuroprotection In Vitro.

Ischemic stroke is a debilitating multi-factorial cerebrovascular disorder, representing an area of tremendous unmet medical need. Combination treatment has been proposed as a promising therapeutic approach towards combating ischemic stroke. The present study employs in vitro oxygen glucose deprivation (OGD) model to evaluate the post-ischemic neuroprotective efficacy of Everolimus and Paroxetine, alone and in combination. Post-OGD treatment with Everolimus and Paroxetine, alone or in combination, significantly improved the cell survival (~ 80%) when compared to the cells subjected to ischemic injury alone. The individual neuroprotective doses of Everolimus and Paroxetine were found to be at 6.25 and 25 nM, respectively. Whereas, the synergistic neuroprotective dose for Everolimus:Paroxetine was 2:10 nM, calculated using the Chou-Talalay combination index and other four mathematical models. The synergistic combination dose downregulated neuroinflammatory genes (Tnf-α, Il1b, Nf-κB, and iNos) and upregulated the neuroprotective genes (Bcl-2, Bcl-xl, Hif-1, and Epo). The mitochondrial functioning and ROS neutralizing ability increased with combination treatment. Further, the active role of nitric oxide synthase and calmodulin were revealed while exploring the bio-activity of Everolimus and Paroxetine through network pharmacology. The present study for the first time demonstrates the synergistic post-ischemic neuroprotective efficacy of combination treatment with Everolimus and Paroxetine in vitro. Taken together, these findings clearly suggest that Everolimus in combination with Paroxetine may represent a promising therapeutic strategy for the treatment of ischemic stroke, further supporting the combination treatment strategy for this debilitating disorder.

Novel RIPK3 inhibitors discovered through a structure-based approach exert post-ischemic neuroprotection.

Necroptosis or programmed necrosis is evident in various neurological disorders such as ischemic stroke. Receptor interacting serine/threonine protein kinase 3 (RIPK3) is one of the crucial targets of necroptosis and inhibition of this protein exerts neuroprotection. However, knowledge regarding the three-dimensional structure and binding site information of this protein is lacking. In the present study, structure-based in silico methods were implemented to identify the key amino acids in the RIPK3 binding site that might be responsible for ligand interactions. Further, novel RIPK3 inhibitors were identified through a dual ensemble screening strategy. Three inhibitors exhibited binding to RIPK3 in micromolar concentrations and exerted post-ischemic neuroprotection in vitro.

Necroptosis: who knew there were so many interesting ways to die?

Conventional knowledge considered apoptosis as the sole form of programmed cell death during development, homeostasis and diseases, whereas necrosis was regarded as an unregulated and uncontrollable process. Recent revelations suggest that necrosis can also occur in a regulated, caspase-independent manner and shares characteristics with both necrosis and apoptosis. The major cell death processes namely apoptosis, autophagy and necrosis are interlinked and contain many common regulatory mechanisms. Mounting evidence indicates that necroptosis contributes to the pathogenesis of various diseases, including ischemic stroke, traumatic brain injury, neurodegenerative disorders and brain tumor. We present here an overview of the molecular mechanisms governing necroptosis and its connection with apoptosis and autophagy processes. Further, the necroptosis mechanisms underlying the neurodegeneration during ischemia reperfusion (I/R) injury are described, with an emphasis on the key proteins involved in this type of cell death. Knowledge regarding programmed cell death (PCD) with relevance to necroptosis may play a significant role in debilitating brain disorders.