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  • Numminen, Elina; Chewapreecha, Claire; Turner, Claudia; Goldblatt, David; Nosten, Francois; Bentley, Stephen D.; Turner, Paul; Corander, Jukka (2015)
    Streptococcus pneumoniae is a significant human pathogen and a leading cause of infant mortality in developing countries. Considerable global variation in the pneumococcal carriage prevalence has been observed and the ecological factors contributing to it are not yet fully understood. We use data from a cohort of infants in Asia to study the effects of climatic conditions on both acquisition and clearance rates of the bacterium, finding significantly higher transmissibility during the cooler and drier months. Conversely, the length of a colonization period is unaffected by the season. Independent carriage data from studies conducted on the African and North American continents suggest similar effects of the climate on the prevalence of this bacterium, which further validates the obtained results. Further studies could be important to replicate the findings and explain the mechanistic role of cooler and dry air in the physiological response to nasopharyngeal acquisition of the pneumococcus.
  • Hurme, Pekka; Homil, Kiara; Lehtinen, Pasi; Turunen, Riitta; Vahlberg, Tero; Vuorinen, Tytti; Camargo, Carlos A. Jr Jr; Gern, James E.; Jartti, Tuomas (2021)
    Background Acute rhinovirus-induced wheezing is common in young children and may respond to systemic corticosteroid. There are no trials on the efficacy of inhaled beta(2)-agonist in this clinical scenario. Objective To study post hoc the short-term (up to 2 months) efficacy of inhaled beta(2)-agonist with and without oral corticosteroid in the first acute rhinovirus-induced severe wheezing episode in young hospitalized children. Methods The study population came from two randomized controlled trials comparing oral prednisolone (2 mg/kg/d for 3 days) to placebo: Vinku (n = 35, NCT00494624) used high-dose regular nebulized salbutamol (0.15 mg/kg 2-4 h intervals) and Vinku2 (n = 60, NCT00731575, EudraCT 2006-007100-42) used inhaled salbutamol on-demand. Both studies used identical detailed follow-up assessments. The primary outcome of the former was the duration of hospitalization and of the latter the occurrence of and the time to a new physician-confirmed wheezing episode within 2 months after discharge. Treatment groups included salbutamol high-dose vs. salbutamol on-demand while adjusting for prednisolone status and acknowledging for interactions with exception of the duration of hospitalization in which prednisolone groups could not be fully used due to protocol differences. Results Median age of subjects was 13 months, 32% were sensitized and 22% had doctor-diagnosed eczema. In the duration of hospitalization, salbutamol high-dose/placebo versus salbutamol on-demand/placebo groups did not differ (p = .12). In the occurrence of and time to relapse within 2 months, a significant group x treatment interaction was observed (both p = .02), such that high-dose group had less and longer time to relapses than on-demand group in prednisolone arm (both p < .05), but no difference was detected in placebo arm (both p > .26). Conclusions In young, hospitalized children with first episode of rhinovirus-induced wheezing, high-dose inhaled salbutamol may interact with oral prednisolone. However, further trials are warranted.
  • Levanova, Alesia; Poranen, Minna M. (2018)
    RNA interference (RNAi), which is mediated by small interfering RNAs (siRNAs) derived from viral genome or its replicative intermediates, is a natural antiviral defense in plants, fungi, and invertebrates. Whether RNAi naturally protects humans from viral invasion is still a matter of debate. Nevertheless, exogenous siRNAs are able to halt viral infection in mammals. The current review critically evaluates the production of antiviral siRNAs, delivery techniques to the infection sites, as well as provides an overview of antiviral siRNAs in clinical trials.
  • Ezzat, Kariem; Pernemalm, Maria; Palsson, Sandra; Roberts, Thomas C.; Järver, Peter; Dondalska, Aleksandra; Bestas, Burcu; Sobkowiak, Michal J.; Levänen, Bettina; Sköld, Magnus; Thompson, Elizabeth A.; Saher, Osama; Kari, Otto K.; Lajunen, Tatu; Ekstrom, Eva Sverremark; Nilsson, Caroline; Ishchenko, Yevheniia; Malm, Tarja; Wood, Matthew J. A.; Power, Ultan F.; Masich, Sergej; Linden, Anders; Sandberg, Johan K.; Lehtiö, Janne; Spetz, Anna-Lena; EL Andaloussi, Samir (2019)
    Artificial nanoparticles accumulate a protein corona layer in biological fluids, which significantly influences their bioactivity. As nanosized obligate intracellular parasites, viruses share many biophysical properties with artificial nanoparticles in extracellular environments and here we show that respiratory syncytial virus (RSV) and herpes simplex virus type 1 (HSV-1) accumulate a rich and distinctive protein corona in different biological fluids. Moreover, we show that corona pre-coating differentially affects viral infectivity and immune cell activation. In addition, we demonstrate that viruses bind amyloidogenic peptides in their corona and catalyze amyloid formation via surface-assisted heterogeneous nucleation. Importantly, we show that HSV-1 catalyzes the aggregation of the amyloid beta-peptide (A beta(42)), a major constituent of amyloid plaques in Alzheimer's disease, in vitro and in animal models. Our results highlight the viral protein corona as an acquired structural layer that is critical for viral-host interactions and illustrate a mechanistic convergence between viral and amyloid pathologies.