What is toxicology and how does toxicity occur?

Host Defence Peptides: A Potent Alternative to Combat Antimicrobial Resistance in the Era of the COVID-19 Pandemic

One of the greatest challenges facing the medical community today is the ever-increasing trajectory of antimicrobial resistance (AMR), which is being compounded by the decrease in our antimicrobial armamentarium. From their initial discovery to the current day, antibiotics have seen an exponential increase in their usage, from medical to agricultural use. Benefits aside, this has led to an exponential increase in AMR, with the fear that over 10 million lives are predicted to be lost by 2050, according to the World Health Organisation (WHO). As such, medical researchers are turning their focus to discovering novel alternatives to antimicrobials, one being Host Defence Peptides (HDPs). These small cationic peptides have shown great efficacy in being used as an antimicrobial therapy for currently resistant microbial variants. With the sudden emergence of the SARS-CoV-2 variant and the subsequent global pandemic, the great versatility and potential use of HDPs as an alternative to conventional antibiotics in treating as well as preventing the spread of COVID-19 has been reviewed. Thus, to allow the reader to have a full understanding of the multifaceted therapeutic use of HDPs, this literature review shall cover the association between COVID-19 and AMR whilst discussing and evaluating the use of HDPs as an answer to antimicrobial resistance (AMR).

Polymeric nanodroplets: an emerging trend in gaseous delivery system

Currently, nanotechnology-based products are gaining tremendous interest in the development of nanocarriers for drug delivery and nano-diagnostic devices. Nanodroplets (NDs) emerge as novel carriers for delivery of gases and actives with a wide range of applications in fields of theranostics, drug delivery and diagnostic devices. NDs are multifunctional carriers composed of an outer shell of drug and polymer that encapsulates the inner core of gases and liquid molecules. This review focuses on properties of NDs, mathematical theories, different polymers used in the preparation of NDs, characterisation, animal models, toxicity and applications of NDs. These nanocarriers are advantageous due to their cost-effectiveness and compatibility with both gaseous and liquid core molecules. NDs are increasingly utilised in the field of healthcare due to their properties like large effective surface area for drug loading and target specificity. These nanocarriers are also employed in the treatment of hypoxia, multiple sclerosis and cancer. In the near future, NDs will advance in fields of personalised medicine and precise theranostics.

[What is a "poison"? Proposal of definition]

We discuss different interpretations of the term poison as well as the need of bringing up to date the changes in this matter according to the science progress. A clear and exact definition is proposed after analysing the factors that affect the relativity of the concept and its boundaries. The proposal for a definition is presented taking into account the most broadly extended concepts concerning its significance. That is to say: "a poison is, for human beings and their non-pathogenic and non-harmful biological environment, an electromagnetic or corpuscular radiation, or a non-infectious chemical agent, structured no larger in size than a small particle or fibre that, after being generated internally or after contact, penetration and/or absorption by a live organism, in sufficiently high dose, can produce or produces a direct or indirect adverse effect unrelated to its temperature or measurable electrical potential difference". The scientific knowledge needs accurate definitions to avoid ambiguities.

Toxicogenomics applied to predictive and exploratory toxicology for the safety assessment of new chemical entities: a long road with deep potholes

Toxicology is the perturbation of metabolism by external factors such as xenobiotics, environmental factors or drugs. As such, toxicology covers a broad range of fields from studies of the whole organism responses to minute biochemical events. Mechanistic toxicogenomics is an attempt to harness genomic tools to understand the physiological basis for a toxic event based on an analysis of transcriptional, translational or metabolomic profiles. These studies are complicated by non-toxic adaptive responses in transcript, protein or metabolite expression levels that have to be distinguished from those that are proximally related to the toxic event. Substantial progress has been made on the identification of biomarkers and the establishment of screens derived from such toxicogenomics studies. The ultimate goal, of course, is predictive toxicogenomics, which is an attempt to infer the likelihood of occurrence of a toxic event with exposure to a new agent based upon comparative responses with large databases of gene, protein or metabolite expression data. Gene expression databases are currently limited by the fact that measurable toxic phenotypes generally precede or at best coincide with the earliest observable changes in transcriptional profiles. Unfortunately, predictive protein databases have been limited by technical difficulties. Metabonomics-based databases, which would probably have the highest predictive value, are limited in turn by the inability to perform high dose studies in humans. This chapter will conclude by reviewing those elements of toxicogenomics that apply specifically to the development of anti-infectives and the potential for accurately modelling the toxicity of future drugs.

Position of immunological techniques in screening in clinical toxicology

There is a continuing increase in the use of immunological techniques in the field of clinical toxicology. This is primarily due to the rapidity by which analytical results are now required, and can be obtained, following the testing of individuals for drug use. There has recently been an increase in the repertoire of assays now available to testing laboratories (e.g., buprenorphine and heroin metabolite assays), with the techniques themselves becoming increasingly more specific for the drugs and/or metabolites being monitored (e.g., methadone metabolite assays). The near patient testing (NPT), or point-of-care testing (POCT), devices are now several generations forward from their inception, with some tests now approaching the sensitivity and specificity of automated laboratory-based methods. This review has been collated from the literature to illustrate some of the possible reasons for the move towards the increasing use of immunological techniques, and to highlight some of the advantages and disadvantages associated with such drug screening methods. In particular, it has been shown that it is important to determine, monitor and review the knowledge and training of the individual using the technique. In addition, quality control and quality assessment are paramount to ensure the validity of any drug testing being performed. It has also been shown that it is vital to maintain and develop the relationships between the staff performing the testing, the laboratory (if the testing is performed using NPT devices), and the clinicians utilising the results obtained from drug testing. Without these links, interpretive errors could arise which could adversely affect the diagnosis and management of patients.