No abstract

In this pilot study, we characterize and evaluate 3D-printed swabs for the collection of nasopharyngeal and oropharyngeal secretion samples for the SARS-CoV-2 detection. Swabs are made with the fused deposition modeling technique using the biopolymer polylactic acid (PLA) which is a medical-grade, biodegradable and low-cost material. We evaluated six swabs with mechanical tests in a laboratory and in an Adult Human Simulator performed by healthcare professionals. We proved the adequacy of the PLA swab to be used in the gold standard reverse transcriptase-polymerase chain reaction (qRT-PCR) for viral RNA detection. Then, we did in vitro validation for cell collection using the 3D-printed swabs and RNA extraction for samples from 10 healthy volunteers. The 3D-printed swabs showed good flexibility and maneuverability for sampling and at the same time robustness to pass into the posterior nasopharynx. The PLA did not interfere with the RNA extraction process and qRT-PCR test. When we evaluated the expression of the reference gene (RNase P) used in the SARS-CoV-2 detection, the 3D-printed swabs showed good reproducibility in the threshold cycle values (Ct = 23.5, range 19–26) that is comparable to control swabs (Ct = 24.7, range 20.8–32.6) with p value = 0.47. The 3D-printed swabs demonstrated to be a reliable, and an economical alternative for mass use in the detection of SARS-CoV-2.

A perchloric acid-soluble protein (PSP), named here tv-psp1, was identified in Trichomonas vaginalis. It is expressed under normal culture conditions according to expressed sequence tag (EST) analysis. On the other hand, Tv-PSP1 protein was identified by mass spectrometry with a 40% of identity to human PSP (p14.1). Polyclonal antibodies against recombinant Tv-PSP1 (rTv-PSP1) recognized a single band at 13.5 kDa in total protein parasite extract by SDS-PAGE and a high molecular weight band analyzed by native PAGE. Structural analysis of Tv-PSP1, using dynamic light scattering, size exclusion chromatography, and circular dichroism spectroscopy, showed a trimeric structure stable at 7 M urea with 38% α-helix and 14% β-sheet in solution and a molecular weight of 40.5 kD. Tv-PSP1 models were used to perform dynamic simulations over 100 ns suggesting a stable homotrimeric structure. Tv-PSP1 was located in the nucleus, cytoplasm, and hydrogenosomes of T. vaginalis, and the in silico analysis by Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) showed interactions with RNA binding proteins. The preliminary results of RNA degradation analysis with the recombinant Tv-PSP1 showed RNA partial deterioration suggesting a possible putative ribonuclease function.

Infection with Trichomonas vaginalis produces a malodorous seropurulent vaginal discharge due to several chemicals, including polyamines. The presence of 1,4-diamino-2-butanone (DAB) reduces the amount of intracellular putrescine by 90%, preventing the cotransport of exogenous spermine. DAB-treated parasites present morphological changes, which are restored by adding exogenous putrescine into the culture medium. However, the effect of polyamines over the trichomonad proteomic profile is unknown. In this study, we used a proteomic approach to analyze the polyamine-depletion and restoration effect by exogenous putrescine on T. vaginalis proteome. In the presence of inhibitor DAB, we obtained 369 spots in polyamine-depleted condition and observed 499 spots in the normal culture media. With DAB treatment, the intensity of 43 spots was increased but was found to be reduced in 39 spots, as compared to normal conditions. Interestingly, in DAB-treated parasites restored with a medium with added exogenous putrescine, 472 spots were found, of which 33 were upregulated and 63 were downregulated in protein intensity. Some of these downregulated proteins in DAB-treated parasites are involved in several cellular pathways such as glycolysis, glycolytic fermentation, arginine dihydrolase pathway, redox homeostasis, host cell binding mediated by carbohydrate, chaperone function, and cytoskeletal remodeling. Interestingly, the intensity of some of the proteins was restored by adding exogenous putrescine. In conclusion, the presence of DAB altered the proteomic profile of T. vaginalis, resulting in a decrease in the intensity of 130 proteins and an increase in the intensity of 43 proteins that was restored by the addition of putrescine.

Multiple studies have established that hyperinflammatory response induced by SARS CoV-2 is a main cause of complications and death in infected subjects. Such dysfunctional immune response has been described as a dysregulated and exacerbated production of cytokines and chemokines that attracts and activates inflammatory cells, which start and sustain pulmonary and systemic damage, thus causing complications that lead to multi organ failure and death. Therefore, we suggest that blocking key inflammation receptors could help to reduce migration and activation of T cells, monocytes/macrophages and neutrophils, thus mitigating the cytokine dysregulation and averting severe complications and death. Importantly, the optimum treatment for COVID-19 severe patients should combine a modulator of the immune response plus a direct antiviral drug against SARS-CoV-2, in order to address both the hyperinflammatory effects of the immune dysregulation and the viral load. Methods: Maraviroc (MVC), a CCR5 antagonist, and Favipiravir (FPV), an antiviral, will be evaluated single and combined, added to the treatment currently used at the Hospital General de México Dr. Eduardo Liceaga for severe COVID-19 patients. One hundred patients will be allocated in four arms [Current treatment only (CT), CT+MVC, CT+FPV, CT+MVC+FPV]. Percentage of patients free of mechanical ventilation or death at day 28, immunophenotyping and viral load will be compared between groups. Discussion: New immune focused therapies are targeting strong inflammation mediators such as IL-6 and IL1-β; nevertheless, to our best knowledge, only one study explores chemotaxis control. The use of a drug therapy that addresses both the regulation of the immune response and the inhibition of viral replication could at the same time, help to alleviate the hyperinflammatory condition and reduce the time of the viral clearance process, therefore improving treatment outcomes.