<p dir="ltr">The recent global pandemic, COVID-19, has revealed to all the importance of understanding the complex relationship between viruses and hosts. Before COVID-19, I started my study of viral protein-host lipid interactions in the hemorrhagic fevers Ebola and Marburg viruses. These viruses contain a matrix protein that interacts with the plasma membrane to facilitate the formation of both authentic viruses and virus-like particles. My goal was to understand the limitations of their specific host lipid interactions. However, when the COVID-19 pandemic began, so to be our swift response in the development of a biosafety level 2 compatible model. This model can be used for studying severe acute respiratory distress syndrome 2 (SARS-CoV-2) assembly, egress, and entry. This model enabled exponentially greater access to more facilities to study the intricacies of SARS-CoV-2 assembly. With more access to studying the virus in a safe model, our goal is to push the understanding of viral assembly faster. I then began to take apart the individual pieces of the model and started to look at understanding the roles that they play independently. The membrane protein is the most abundant structural protein and I studied the specific lipid interactions of the soluble fraction of the protein. Physicians observed nucleocapsid protein mutations in the clinic with the increasing number of SARS-CoV-2 variants that are on the rise. The microscopy data collected can give us more insight into perhaps how the nucleocapsid protein induces the formation of filopodia structures at the plasma membrane. The envelope protein proved to be a challenge, but I determined a specific envelope and ceramide interaction in cells. The envelope protein was also causing the formation of microvesicles for an undefined function. I was able to determine the subcellular localization of the protein to the mitochondria. The localization to the mitochondria appears to induce depolarization of the mitochondria membrane action potential and induces the increase in mitochondria dysfunction signal, cytochrome c. Although the mitochondria were dysfunctional, there was no increase in apoptosis signal in the presence of the protein alone.</p>

Our objective was to analyze longitudinal cellular and humoral immune responses to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination in people with multiple sclerosis (pwMS) on B-cell depleting treatment (BCDT) compared to pwMS without immunotherapy. We further evaluated the impact of COVID-19 infection and vaccination timing. PwMS (n = 439) on BCDT (ocrelizumab, rituximab, ofatumumab) or without immunotherapy were recruited for this prospective cohort study between June 2021 and June 2022. SARS-CoV-2 spike-specific antibodies and interferon- release of CD4 and CD8 T-cells upon stimulation with spike protein peptide pools were analyzed at different timepoints (after primary vaccination, 3 and 6 months after primary vaccination, after booster vaccination, 3 months after booster). Humoral response to SARS-CoV-2 was consistently lower whereas T-cell response was higher in patients with BCDT compared to controls. Cellular and humoral responses decreased over time after primary vaccination and increased again upon booster vaccination, with significantly higher antibody titers after booster than after primary vaccination in both untreated and B-cell-depleted pwMS. COVID-19 infection further led to a significant increase in SARS-CoV-2-specific responses. Despite attenuated B-cell responses, a third vaccination for patients with BCDT seems recommendable, since at least partial protection can be expected from the strong T-cell response. Moreover, our data show that an assessment of T-cell responses may be helpful in B-cell-depleted patients to evaluate the efficacy of SARS-CoV-2 vaccination.

Depuis l'émergence de la pandémie de SARS-CoV-2 en décembre 2019, plus de 675 millions de cas confirmés ont été signalés dans le monde, dont 4,6 millions de cas au Canada uniquement. Bien que la plupart des individus récupèrent sans séquelles, 10 à 20 % des survivants signalent des symptômes persistants au-delà de quatre semaines après une infection par le SARS-CoV-2, tels que la fatigue, les altérations cognitives, la toux, l'anxiété, la dépression, la douleur thoracique et autres, connus sous le nom de COVID longue ou de condition post-SARS-CoV-2 (PCC). Par conséquent, la physiopathologie, le diagnostic et la prise en charge de la PCC sont devenus un axe de recherche majeur. Pour contribuer à la compréhension de la PCC, nous avons mené le projet IPCO (Institut de Recherches cliniques de Montréal (IRCM) Post-COVID-19 Research Clinic), en posant comme hypothèses 1 que les personnes infectés par le SARS-CoV-2 au Québec présenteraient des signes et symptômes fréquents et variés post-phase aiguë, affectant différents systèmes d'organes, et 2 Les niveaux élevés de D-dimères dans PCC ne sont pas pertinents pour les événements thromboemboliques 3 que Chez les individus atteints de la PCC, la vaccination contre la COVID-19 réduirait les symptômes de la PCC en diminuant l'inflammation. Pour évaluer ces hypothèses, nous avons recruté des participants âgés de plus de 18 ans, un à 18 mois après l'infection aiguë, présentant au moins un symptôme persistant, et programmé des visites de base et de suivi à 3-6 mois, 1 an et 2 ans post-infection aiguë. Chaque visite comprenait des évaluations cliniques, des prélèvements, des évaluations en laboratoire, des questionnaires sur l'alimentation et le bien-être, ainsi que des évaluations de la physiologie pulmonaire et cardiaque. Sur la base d'une étude allemande qui a catégorisé les symptômes du PCC et les individuals en trois groupes de sévérité, nous avons classé nos participants en trois niveaux de sévérité : non/légère (score du PCC <10,75), modérée (10,75 < score du PCC < 26,25) et sévère (score du PCC > 26,25). Cette thèse présente les résultats de trois sous-études IPCO. Dans l'étude descriptive, nous avons observé que la fatigue, les problèmes de mémoire et les maux de tête étaient les symptômes de PCC les plus courants, la majorité de nos participants étant des femmes et ayant été traités en ambulatoire pendant la phase aiguë. Dans l'étude transversale, nous avons constaté des différences significatives dans les mesures de santé et de bien-être à tous les moments, mais aucune différence significative dans les résultats des tests physiologiques entre les groupes PCC non/léger, modéré et sévère. Dans l'étude longitudinale, les marqueurs de l'inflammation se sont améliorés au fil du temps, mais le taux métabolique basal et la masse grasse ont augmenté. Dans la deuxième étude, nous avons observé une forte prévalence de participants ayant des niveaux de D-dimères, qui n'étaient pas associés à des événements thromboemboliques, et aucune corrélation entre le niveau de D-dimères et les niveaux de cytokines et de chimiokines. Dans la troisième étude, nous avons observé que les participants vaccinés présentaient significativement moins de symptômes de PCC. Notre étude fournit une meilleure compréhension de la physiopathologie du PCC et de l'effet de la vaccination sur le profil clinique et inflammatoire du PCC, ce qui pourrait aider à la conception d'outils de gestion clinique et de recherche futurs. / Since the emergence of the SARS-CoV-2 pandemic in December 2019, over 675 million confirmed cases have been reported globally, with 4.6 million cases in Canada alone. Although most individuals recover without residual disease, 10-20% of survivors report symptoms persisting beyond four weeks after SARS-CoV-2 infection, such as fatigue, cognitive impairments, cough, anxiety, depression, chest pain, and others known as long-COVID or post SARS-CoV-2 condition (PCC). Consequently, the pathophysiology, diagnosis, and management of PCC have become a significant focus of research. To contribute to the understanding of PCC, we conducted the IPCO (Institut de Recherches cliniques de Montréal (IRCM) Post-COVID-19 Research Clinic) project, hypothesizing that 1 SARS-CoV-2 infected individuals in Quebec would present frequent and varied signs and symptoms post-acute phase, affecting different organ systems, and that 2 high D-dimer level in PCC is irrelevant to thromboembolic events , and 3 in individuals with PCC, COVID-19 vaccination would decrease PCC symptoms by reducing inflammation. To evaluate these hypotheses, we enrolled participants aged >18 years, one to 18 months post-acute infection, with at least one persistent symptom, and scheduled baseline and follow-up visits at 3-6 months, 1 year, and 2 years post-acute infection. Each visit involved clinical evaluations, sampling, laboratory evaluations, diet and well-being questionnaires, and pulmonary and cardiac physiology evaluations. Based on a German study that categorized PCC symptoms and individuals into three severity groups, we classified our participants into three severity levels: non/mild (PCC score < 10.75), moderate (10.75 < PCC score < 26.25), and severe (PCC score > 26.25). This thesis reports the results of three IPCO studies. In the descriptive study, we observed that fatigue, memory problems, and headaches were the most common PCC symptoms, with the majority of our participants being female and managed as outpatients during the acute phase. In the cross-sectional study, we noted significant differences in health and well-being measurements at all time points, but no significant difference in physiological tests' results between different severity groups. In the longitudinal study, markers of inflammation improved over time, but the basal metabolic rate and body fat increased. In the second study, we observed a high prevalence of participants having D-dimer levels in blood, which were not associated with thromboembolic events, and no correlation between D-dimer levels and blood cytokine/ chemokine levels. In the third study, we observed that vaccinated participants had significantly fewer PCC symptoms, fewer organ systems affected, higher well-being scores, and lower blood cytokine/chemokine levels than the non-vaccinated group. We also observed correlations between certain cytokines/chemokines, as well as between clinical parameters and certain cytokines/chemokines. Our study provides a better understanding of the pathophysiology of PCC and effect of vaccination on the clinical and inflammatory profile of PCC, which could assist future research and clinical management tool design.

The rapidly spreading pandemic of SARS-CoV-2 (COVID-19) infection with high morbidity and mortality has overwhelmed the global healthcare services. With mysterious origins and the capacity of affecting multiple types of tissues, SARS-CoV-2 has baffled many scientists - which has posed great challenges in the development of pharmaceutical treatments and preventions (i.e., vaccination). The COVID-19 pandemic has also led to a slew of non-pharmaceutical interventions (NPIs) to slow down the spread of the virus. The sudden imposition of these NPIs including social distancing, lock-down, school closures, isolation, and quarantine of suspected cases or contacts, has greatly affected the mental health of children and adolescents. Concerns about the impact of these NPIs on mental health, especially for vulnerable populations such as children and adolescents, have emerged. This study discusses several different aspects of the impact of the COVID-19 pandemic on the mental health of children and adolescents.Accumulating evidence has shown that the vast majority of children and adolescents exposed to the SARS-CoV-2 virus are asymptomatic, although few cases turned unfortunately severely ill. The genomics, microbiology, and biochemistry of this novel coronavirus reveal several peculiarities, making it a tough entity. The profound impact of social distancing along with the closure of schools, parks, and other recreational activities on the delicate minds of children and adolescents makes them irritable, angry, and rebellious. This assumes a major challenge in children with mental health issues or in those with special needs. Lock-down, quarantine and isolation further complicate the mental health issues and are discussed along with remedial measures. The impact of an already overwhelmed medical care system on the mental healthcare quality can be profound and needs a specially chartered approach by the psychiatrists supplementing the COVID-19 control activities. Children/adolescents with neuropsychiatric issues need special care, as they have abnormal impulsive behaviour and actions such as running away, unhygienic acts, spitting etc. All these mental health issues in children and adolescents, who form a sizable population of the society and are the future of the planet, forms the subject matter of this work. Thus, all programmes of COVID-19 control must simultaneously address these important mental health issues of children and adolescents to prevent this ‘parallel pandemic’ of psychiatric disorders. The latter may persist much longer and prove equally challenging and costly.

Objetivo: Desarrollar una metodología para evaluar el nivel de protección respiratoria de respiradores, mascarillas quirúrgicas y mascarillas comunitarias que usa la población peruana, usando partículas de un tamaño similar a las que contienen al virus activo del SARS-CoV-2. Materiales y métodos: Se ha determinado una relación lineal directa entre el logaritmo de la concentración de partículas suspendidas en aire y el tiempo transcurrido; por lo cual es posible comparar la cantidad de partículas internas y externas a la mascarilla o respirador en un mismo periodo y conocer el porcentaje de protección respiratoria de cada muestra evaluada. Resultados: Se ha logrado implementar una metodología para evaluar el nivel de protección respiratoria ante aerosoles menores a 5,0 μm. Asimismo, el empleo de accesorios como ligas o ajustadores detrás de cabeza y nuca, y el uso de clips nasales robustos, incrementan significativamente el nivel de protección respiratoria ante partículas con alta probabilidad de contener al SARS-CoV-2. Conclusiones: Se observa una concordancia entre los valores de protección respiratoria obtenidos y los esperados, considerando el nivel de filtración del material empleado de cada mascarilla quirúrgica o respirador, y su nivel de ajuste. Se observó un incremento significativo en los niveles de protección respiratoria. / Objective: To develop a methodology for evaluating the level of respiratory protection provided by res- pirators, surgical masks and community face masks used by the Peruvian population; protection was evaluated against particles of a size similar to those containing active SARS-CoV-2 virus. Materials and methods: A direct linear relationship has been determined between the logarithm of the concentration of airborne particles and the elapsed time; thus, it is possible to compare the quantity of particles inside and outside of the mask or respirator in the same time period, as well as to obtain the percentage of re- spiratory protection for each evaluated sample. Results: A methodology was established to evaluate the level of respiratory protection against aerosols smaller than 5.0 μm. Also, the use of accessories such as garters or adjusters behind the head and neck, and the use of strong nasal clips, significantly increased the level of respiratory protection against particles with a high probability of containing SARS-CoV-2. Conclusions: We found concordance between the obtained respiratory protection values and those ex- pected, considering the filtration level of the material used for each surgical mask or resp s well as the tightness. A significant increase in the levels of respiratory protection was observed.

Health is often defined in terms of absence of disease or pathological processes, but this is a definition of exclusion and incomplete. For example, SARS-CoV-2 viral load does not reliably predict disease severity, and so individuals must vary in their ability to control inflammation and maintain normal tissue homeostasis. This host defense strategy is called disease tolerance, and better understanding of disease tolerance mechanisms could change the way that we treat disease and work to maintain health. The first project presented in this dissertation found that after accounting for effects of age and sex, innate lymphoid cells (ILCs), but not T cells, were lower in adults and children sick with COVID-19 or MIS-C, independent of lymphopenia. Furthermore, abundance of ILCs, but not of T cells, correlated inversely with disease severity. These blood ILCs were shown to produce amphiregulin, a protein implicated in disease tolerance and tissue homeostasis, and the percentage of amphiregulin-producing ILCs was lower in males. These results suggest that, by promoting disease tolerance, homeostatic ILCs decrease morbidity and mortality associated with SARS-CoV-2 infection, and that lower ILC abundance accounts for increased COVID-19 severity with age and in males. The second project describes a novel mouse model of epigenetic inheritance wherein paternal influenza A virus (IAV) infection results in less severe influenza disease in IAV infected offspring. This offspring phenotype was not attributable to differences in viral load, indicating a possible difference in disease tolerance. Paternal caloric deprivation decreased, and influenza B virus infection increased, offspring influenza disease severity, and in vitro fertilization demonstrated sperm are sufficient to transfer IAV-associated epigenetic inheritance phenotypes. These findings represent a foundation for further work that, by continuing to elucidate the mechanisms of disease tolerance and epigenetic inheritance, could provide novel therapeutic interventions to help promote and maintain health.

Considerable attention has been focused on nanomaterials and their extensive applications. Metallic nanoparticles, especially gold nanoparticles (AuNPs) and silver nanoparticles (AgNPs), due to their superior physical, chemical, and optical properties, are vastly developed for numerous biomedical applications such as drug and gene delivery systems, diagnostic biosensors, imaging, and therapeutics. This study presents a low-cost method for the fabrication of self-assembled metallic nanoparticles, including gold and silver, via a reactive blade coating process, which is carried out based on in situ reduction of the metal precursors. This technique is a roll-to-roll compatible technique suitable for scalable nanomanufacturing. Oleylamine was used as a reducer agent, and gold (III) chloride hydrate and silver salts, including silver nitrate and silver perchlorate hydrate, were used as the metal precursors. Fabrication was carried out by first blade coating the reducer ink and subsequently coating the precursor ink followed by 3 hours of heat treatment. Various solvent systems were used to examine the effect of different solvents on the fabrication process. Surface morphology, crystalline phase composition, and plasmon resonance of the coated samples were characterized by scanning electron microscopy (SEM), X-ray diffractometer (XRD), and UV-Vis spectroscopy, respectively. Results demonstrated the synthesis of spherical self-assembled AuNPs using toluene (TOL) and isopropyl alcohol (IPA) for reducing and precursor solvents, respectively. Changing the concentration of reactants or increasing the coating layers exhibited a change in the average size of AuNPs. Self-assembled AuNPs thin films were also demonstrated to have the potential to be used as a biosensing platform based on localized surface plasmon resonance (LSPR) effect to detect the elevated levels of glucose in an aqueous solution. Recently, the world has faced a pandemic of Covid-19 caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which has threatened human health and has brought a worldwide devastating economic and social crisis. Hence, finding a solution to mitigate the current breakout of Covid-19 is vital to protect the international community from its causing harm. AgNPs as an antimicrobial agent, which has exhibited promising antiviral activity against several viruses, can offer a resolution to combat the spread of Covid-19. In this regard, AgNPs thin films were fabricated analogously via blade coating using various reducer and silver salt inks made of different solvent systems. Virucidal efficacy of reactive blade coated AgNPs on glass substrates was analyzed against human coronavirus 229E, a virus from the Coronavirus family, as a surrogate SARS-CoV-2 (according to the Level 2 Biosafety facility at uOttawa). Plaque forming assay indicated more than 99.99% reduction in infectivity of the virus when it contacts the AgNPs coated glass for 30 min before infecting cells. These results suggest the excellent potential for reactive blade coated AgNPs as an antiviral agent against coronavirus to avoid the spread of the virus.

No description available.

Background: Since its emergence in December 2019, SARS-CoV-2, the coronavirus responsible for COVID-19, has spread across the globe, infected millions of people and caused several million deaths. One promising intervention to combat the ongoing COVID-19 pandemic is mesenchymal stem/stromal cells (MSCs). Many trials were registered at the onset of the pandemic to determine the safety and efficacy of MSCs in COVID-19 patients. However, currently published studies are underpowered to provide an estimate of safety and efficacy on their own. Thus, a living systematic review (SR) is needed to establish the benefits and drawbacks of MSCs for COVID-19 on a relevant timescale. Methods: Systematic literature searches were conducted on Feb 3rd, 2021 and November 15th, 2021 to identify all English-language, full-text, clinical studies examining MSCs to treat COVID-19. (PROSPERO:CRD42021225431). Findings/Conclusions: Our first search identified nine studies (4 controlled) examining the use of MSC derived products to treat COVID-19 patients. This first iteration of our SR revealed that MSCs were safe and reduced mortality in patients suffering from COVID-19. However, risk of bias (RoB) and poor adherence to ISCT cell product characterization guidelines limited the strength of our conclusions. In the second iteration of our living SR, we only included controlled studies to strengthen our conclusions. We identified eleven controlled studies (5 RCTs). MSCs continued to demonstrate safety and efficacy at reducing mortality at study endpoint (RR: 0.50 [0.34 to 0.75, 95% CI, p=0.0006, I2=0%]). However, we continued to encounter barriers which prevented us from drawing more definitive conclusions. A master protocol appears necessary to facilitate the accelerated accumulation of high-quality evidence where standardized outcome reporting and consistent product characterization allow for a more definitive and timely estimate regarding the safety and efficacy of this cell-based therapy for COVID-19.

<p>In the year of 2020, an international pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has afflicted tens of millions of people’s life also disrupting global economics. Diagnostic testing is an important part of ensuring public health until a vaccine that has been shown to be safe and effective is made available to the general public. Most tests for detecting COVID-19 utilize quantitative polymerase chain reaction (qPCR) assays, which is a specific and relatively simple quantitative assay that could provide adequate sensitivity for diagnosing early infection. Although powerful, these lab-based molecular assays have a significant lag time, usually several days before receiving results. To satisfy the needs of different purposes (diagnostics, screening, and surveillance), a unified approach is impractical. This thesis presents an alternative testing method supporting the current procedure of point of care (POC) testing and in community testing. This paper-based test overcomes the limitations of current testing methods by utilizing reverse-transcription loop-mediated isothermal amplification (RT-LAMP) and receiving the result on-site by a color change in the presence of the virus within 60 minutes. The test utilizes untreated freshly collected saliva, a less invasive specimen, as the sample and possesses a limit of detection (LoD) of 200 copies of virus per microliter of whole saliva with an analytical sensitivity of 97% and analytical specificity of 100%. The test requires minimal operator training and could be fabricated on a large-scale using roll-to-roll methods. Since the test is based on nucleic acids, the testing platform itself lends to further applications <a>including food safety monitoring, animal diagnostic, etc. simply by changing the specific primers</a>. </p>