MDPI - Publisher of Open Access Journals

16 pages, 853 KB

Open AccessReview

On the Evolutionary Trajectory of SARS-CoV-2: Host Immunity as a Driver of Adaptation in RNA Viruses

by Jacob Warger and Silvana Gaudieri

Viruses 2023, 15(1), 70; https://doi.org/10.3390/v15010070 - 26 Dec 2022

Cited by 7 | Viewed by 4541

Host immunity can exert a complex array of selective pressures on a pathogen, which can drive highly mutable RNA viruses towards viral escape. The plasticity of a virus depends on its rate of mutation, as well as the balance of fitness cost and benefit of mutations, including viral adaptations to the host’s immune response. Since its emergence, SARS-CoV-2 has diversified into genetically distinct variants, which are characterised often by clusters of mutations that bolster its capacity to escape human innate and adaptive immunity. Such viral escape is well documented in the context of other pandemic RNA viruses such as the human immunodeficiency virus (HIV) and influenza virus. This review describes the selection pressures the host’s antiviral immunity exerts on SARS-CoV-2 and other RNA viruses, resulting in divergence of viral strains into more adapted forms. As RNA viruses obscure themselves from host immunity, they uncover weak points in their own armoury that can inform more comprehensive, long-lasting, and potentially cross-protective vaccine coverage. Full article

(This article belongs to the Special Issue What SARS-CoV-2 Variants Have Taught Us: Evolutionary Challenges of RNA Viruses)

► Show Figures

Figure 1

11 pages, 6264 KB

Open AccessEditor’s ChoiceArticle

Biomimetic Transparent Eye Protection Inspired by the Carapace of an Ostracod (Crustacea)

by Andrew R. Parker, Barbara P. Palka, Julie Albon, Keith M. Meek, Simon Holden and F. Tegwen Malik

Nanomaterials 2021, 11(3), 663; https://doi.org/10.3390/nano11030663 - 8 Mar 2021

Cited by 2 | Viewed by 3099

Abstract

In this study we mimic the unique, transparent protective carapace (shell) of myodocopid ostracods, through which their compound eyes see, to demonstrate that the carapace ultrastructure also provides functions of strength and protection for a relatively thin structure. The bulk ultrastructure of the transparent window in the carapace of the relatively large, pelagic cypridinid (Myodocopida) Macrocypridina castanea was mimicked using the thin film deposition of dielectric materials to create a transparent, 15 bi-layer material. This biomimetic material was subjected to the natural forces withstood by the ostracod carapace in situ, including scratching by captured prey and strikes by water-borne particles. The biomimetic material was then tested in terms of its extrinsic (hardness value) and intrinsic (elastic modulus) response to indentation along with its scratch resistance. The performance of the biomimetic material was compared with that of a commonly used, anti-scratch resistant lens and polycarbonate that is typically used in the field of transparent armoury. The biomimetic material showed the best scratch resistant performance, and significantly greater hardness and elastic modulus values. The ability of biomimetic material to revert back to its original form (post loading), along with its scratch resistant qualities, offers potential for biomimetic eye protection coating that could enhance material currently in use. Full article

(This article belongs to the Special Issue Photonic Properties of Nanostructured Biomaterials)

► Show Figures

Figure 1

11 pages, 281 KB

Open AccessCommentary

COVID-19 and Diagnostic Testing for SARS-CoV-2 by RT-qPCR—Facts and Fallacies

by Stephen Bustin, Reinhold Mueller, Gregory Shipley and Tania Nolan

Int. J. Mol. Sci. 2021, 22(5), 2459; https://doi.org/10.3390/ijms22052459 - 28 Feb 2021

Cited by 24 | Viewed by 10009

Abstract

Although molecular testing, and RT-qPCR in particular, has been an indispensable component in the scientific armoury targeting SARS-CoV-2, there are numerous falsehoods, misconceptions, assumptions and exaggerated expectations with regards to capability, performance and usefulness of the technology. It is essential that the true strengths and limitations, although publicised for at least twenty years, are restated in the context of the current COVID-19 epidemic. The main objective of this commentary is to address and help stop the unfounded and debilitating speculation surrounding its use. Full article

(This article belongs to the Section Molecular Pathology, Diagnostics, and Therapeutics)

27 pages, 2436 KB

Open AccessReview

Quinolones: Mechanism, Lethality and Their Contributions to Antibiotic Resistance

by Natassja G. Bush, Isabel Diez-Santos, Lauren R. Abbott and Anthony Maxwell

Molecules 2020, 25(23), 5662; https://doi.org/10.3390/molecules25235662 - 1 Dec 2020

Cited by 344 | Viewed by 53569

Abstract

Fluoroquinolones (FQs) are arguably among the most successful antibiotics of recent times. They have enjoyed over 30 years of clinical usage and become essential tools in the armoury of clinical treatments. FQs target the bacterial enzymes DNA gyrase and DNA topoisomerase IV, where they stabilise a covalent enzyme-DNA complex in which the DNA is cleaved in both strands. This leads to cell death and turns out to be a very effective way of killing bacteria. However, resistance to FQs is increasingly problematic, and alternative compounds are urgently needed. Here, we review the mechanisms of action of FQs and discuss the potential pathways leading to cell death. We also discuss quinolone resistance and how quinolone treatment can lead to resistance to non-quinolone antibiotics. Full article

(This article belongs to the Special Issue Quinolones: Chemistry and Biological Activities)

► Show Figures

Graphical abstract

27 pages, 821 KB

Open AccessArticle

Lifestyle Behaviours Add to the Armoury of Treatment Options for Panic Disorder: An Evidence-Based Reasoning

by Rod Lambert

Int. J. Environ. Res. Public Health 2015, 12(6), 7017-7043; https://doi.org/10.3390/ijerph120607017 - 18 Jun 2015

Cited by 2 | Viewed by 7140

Abstract

This article presents an evidence-based reasoning, focusing on evidence of an Occupational Therapy input to lifestyle behaviour influences on panic disorder that also provides potentially broader application across other mental health problems (MHP). The article begins from the premise that we are all different. It then follows through a sequence of questions, examining incrementally how MHPs are experienced and classified. It analyses the impact of individual sensitivity at different levels of analysis, from genetic and epigenetic individuality, through neurotransmitter and body system sensitivity. Examples are given demonstrating the evidence base behind the logical sequence of investigation. The paper considers the evidence of how everyday routine lifestyle behaviour impacts on occupational function at all levels, and how these behaviours link to individual sensitivity to influence the level of exposure required to elicit symptomatic responses. Occupational Therapists can help patients by adequately assessing individual sensitivity, and through promoting understanding and a sense of control over their own symptoms. It concludes that present clinical guidelines should be expanded to incorporate knowledge of individual sensitivities to environmental exposures and lifestyle behaviours at an early stage. Full article

► Show Figures

Figure 1

20 pages, 288 KB

Open AccessReview

Plant Antimicrobial Agents and Their Effects on Plant and Human Pathogens

by Rocío González-Lamothe, Gabriel Mitchell, Mariza Gattuso, Moussa S. Diarra, François Malouin and Kamal Bouarab

Int. J. Mol. Sci. 2009, 10(8), 3400-3419; https://doi.org/10.3390/ijms10083400 - 31 Jul 2009

Cited by 325 | Viewed by 30193

Abstract

To protect themselves, plants accumulate an armoury of antimicrobial secondary metabolites. Some metabolites represent constitutive chemical barriers to microbial attack (phytoanticipins) and others inducible antimicrobials (phytoalexins). They are extensively studied as promising plant and human disease-controlling agents. This review discusses the bioactivity of several phytoalexins and phytoanticipins defending plants against fungal and bacterial aggressors and those with antibacterial activities against pathogens affecting humans such as Pseudomonas aeruginosa and Staphylococcus aureus involved in respiratory infections of cystic fibrosis patients. The utility of plant products as “antibiotic potentiators” and “virulence attenuators” is also described as well as some biotechnological applications in phytoprotection. Full article

(This article belongs to the Special Issue Antimicrobial Agents)

► Show Figures

Search Results (6)

Further Information

Guidelines

MDPI Initiatives

Follow MDPI

Saved Queries

Search Filter Reset All

Years

Feature Papers

Subjects

Journals

Article Types

Countries / Regions

Search Results (6)

Further Information

Guidelines

MDPI Initiatives

Follow MDPI