Dextran '40' 10% / Sodium chloride 0.9% infusion 500ml bags

BackgroundDextran sodium sulfate (DSS) is commonly used in mouse studies to induce a very reproducible colitis that effectively mimics the clinical and histological features of human inflammatory bowel disease (IBD) patients, especially ulcerative colitis. However, the mechanisms of action of DSS remain poorly understood, and observations by our laboratory and other groups indicate that DSS contamination of colonic tissues from DSS-treated mice potently inhibits the quantitative reverse-transcription polymerase chain reaction (qRT-PCR) amplification of mRNA.ResultsA prior study used poly-A-mediated mRNA purification to remove DSS from RNA extracts, but we herein report a second efficient and cost-effective approach to counteract this inhibition, using lithium chloride precipitation to entirely remove DSS from RNAs. We also explored how DSS interferes with qRT-PCR process, and we report for the first time that DSS can alter the binding of reverse transcriptase to previously primed RNA and specifically inhibits the enzymatic activities of reverse transcriptase and Taq polymerase in vitro. This likely explains why DSS-treated colonic RNA is not suitable to qRT-PCR amplification without a previous purification step.ConclusionIn summary, we provide a simple method to remove DSS from colonic RNAs, and we demonstrate for the first time that DSS can inhibit the activities of both polymerase and reverse transcriptase. In order to reliably analyze gene expression in the colonic mucosa of DSS-treated mice, the efficiency rate of qRT-PCR must be the same between all the different experimental groups, including the water-treated control group, suggesting that whatever the duration and the percentage of the DSS treatment, RNAs must be purified.

Abstract licence: CC BY 2.0

PurposeTo provide an overview of artificial tears marketed in the following Nordic countries: Denmark, Finland, Norway, Iceland and Sweden. Furthermore, this review aimed to highlight the different preservatives and other constituents found in artificial tears in the Nordic market, focussing on adverse effects.MethodsArtificial tears appearing in online pharmacies in Denmark, Norway, Sweden, Finland and Iceland were included, and tables listing their components were created. Based on the preservatives and other constituents found in the artificial tears on the Nordic market, a literature search was conducted to investigate differences and potential adverse effects. This was achieved using PubMed with MeSH and free text search terms. Included articles were (i) studies performed on humans in vivo or in vitro human models, (ii) published between 2000 and 2023 and (iii) focussing on adverse effects, preservatives, toxicity, other constituents and preservative-free artificial tears.ResultsA total of 88 artificial tears were found on the Nordic market. Approximately 32% (28 out of 88) of the artificial tears contain preservatives. Eleven of these are preserved with benzalkonium chloride (BAK) or cetrimide. After a thorough literature search, evidence has been found for the toxic effects of BAK and cetrimide. There is no evidence of toxic effects of lubricants, osmoprotectants and lipids.ConclusionsThe findings of this review highlight the paradoxical fact that many treatments for ocular surface diseases contain toxic preservatives that may lead to worsening of the condition. In particular, long-time toxic effects of BAK may contribute to disease progression.

Abstract licence: CC BY-NC-ND

Global concerns about environmental pollution, poor waste management, and the rise in antimicrobial resistance due to uncontrolled antibiotic use have driven researchers to seek alternative, multifaceted solutions. Plants, animals, microorganisms, and their processing wastes serve as valuable sources of natural biopolymers and bioactive compounds. Through nanotechnology, these can be assembled into formulations with enhanced antimicrobial properties, high safety, and low toxicity. This review explores polysaccharides, including chitosan, alginate, starch, pectin, cellulose, hemicellulose, gums, carrageenan, dextran, pullulan, and hyaluronic acid, used in nanotechnology, highlighting their advantages and limitations as nanocarriers. Addressing the global urgency for alternative antimicrobials, we examined natural compounds derived from plants, microorganisms, and animals, such as phytochemicals, bacteriocins, animal antimicrobial peptides, and proteins. Focusing on their protection and retained activity, this review discusses polysaccharide-based nanoformulations with natural antimicrobials, including nanoparticles, nanoemulsions, nanocapsules, nanoplexes, and nanogels. Special emphasis is placed on strategies and formulations for the encapsulation, entrapment, and conjugation of natural compounds using polysaccharides as protective carriers and delivery systems, including a brief discussion on their future applications, prospects, and challenges in scaling up.

Abstract licence: CC BY