Publications by authors named "Rebecca Lever"

Imatinib is a chemotherapeutic agent known to cause severe side effects when administrated systemically. Encapsulating imatinib in co-polymer poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) offers a targeted drug delivery. In this work, PLGA 50:50 and PLGA 75:25 NPs encapsulated imatinib using the electrohydrodynamic atomisation technique.

View Article and Find Full Text PDF

Nucleases are strictly regulated and often localized in the cell to avoid the uncontrolled degradation of DNA and RNA. Here, a new type of nuclease complex, composed of RecJ3, RecJ4, and aRNase J, was identified through its ATP-dependent association with the ubiquitin-like SAMP1 and AAA-ATPase Cdc48a. The complex was discovered in , an archaeon lacking an RNA exosome.

View Article and Find Full Text PDF

Hel308 helicases promote genome stability in archaea and are conserved in metazoans, where they are known as HELQ. Their helicase mechanism is well characterised, but it is unclear how they specifically contribute to genome stability in archaea. We show here that a highly conserved motif of Hel308/HELQ helicases (motif IVa, F/YHHAGL) modulates both DNA unwinding and a newly identified strand annealing function of archaeal Hel308.

View Article and Find Full Text PDF

DNA strand breaks are repaired by DNA synthesis from an exposed DNA end paired with a homologous DNA template. DNA polymerase delta (Pol δ) catalyses DNA synthesis in multiple eukaryotic DNA break repair pathways but triggers genome instability unless its activity is restrained. We show that human HelQ halts DNA synthesis by isolated Pol δ and Pol δ-PCNA-RPA holoenzyme.

View Article and Find Full Text PDF

Background: Interprofessional education (IPE) at university level is an essential component of undergraduate healthcare curricula, as well as being a requirement of many associated regulatory bodies. In this study, the perception of pharmacy and medical students' of remote IPE was evaluated.

Methods: A series of IPE sessions took place via Zoom and students' feedback was collected after each session.

View Article and Find Full Text PDF

Genome instability is a characteristic enabling factor for carcinogenesis. HelQ helicase is a component of human DNA maintenance systems that prevent or reverse genome instability arising during DNA replication. Here, we provide details of the molecular mechanisms that underpin HelQ function-its recruitment onto ssDNA through interaction with replication protein A (RPA), and subsequent translocation of HelQ along ssDNA.

View Article and Find Full Text PDF

Terbinafine (TBF) is commonly used in the management of fungal infections of the skin because of its broad spectrum of activity. Currently, formulations containing the free base and salt form are available. However, there is only limited information in the literature about the physicochemical properties of this drug and its uptake by the skin.

View Article and Find Full Text PDF

The properties of commercially prepared heparin as an anticoagulant and antithrombotic agent in medicine are better understood than is the physiological role of heparin in its native form, where it is uniquely found in the secretory granules of mast cells. In the present study we have isolated and characterised the glycosaminoglycans (GAGs) released from degranulating rat peritoneal mast cells. Analysis of the GAGs by NMR spectroscopy showed the presence of both heparin and the galactosaminoglycan dermatan sulphate; heparinase digestion profiles and measurements of anticoagulant activity were consistent with this finding.

View Article and Find Full Text PDF

Hexamidine diisethionate (HEX D) has been used for its biocidal actions in topical preparations since the 1950s. Recent data also suggest that it plays a beneficial role in skin homeostasis. To date, the extent to which this compound penetrates the epidermis has not been reported nor how its topical delivery may be modulated.

View Article and Find Full Text PDF

Heparin has been recognized as a valuable anticoagulant and antithrombotic for several decades and is still widely used in clinical practice for a variety of indications. The anticoagulant activity of heparin is mainly attributable to the action of a specific pentasaccharide sequence that acts in concert with antithrombin, a plasma coagulation factor inhibitor. This observation has led to the development of synthetic heparin mimetics for clinical use.

View Article and Find Full Text PDF

Hexamidine diisethionate (HEX D) has been used in the personal care industry and in a number of over-the-counter (OTC) drug products as an antimicrobial agent since the 1950's. Recently, the compound has also been investigated for its beneficial effects on skin health. Surprisingly, there is only limited information describing the physicochemical properties of this compound in the literature.

View Article and Find Full Text PDF

PEGylation is the covalent conjugation of PEG to therapeutic molecules. Protein PEGylation is a clinically proven approach for extending the circulation half-life and reducing the immunogenicity of protein therapeutics. Most clinically used PEGylated proteins are heterogeneous mixtures of PEG positional isomers conjugated to different residues on the protein main chain.

View Article and Find Full Text PDF

Heparanase (HPSE1) is known to be involved in mechanisms of metastatic tumor cell migration. This enzyme selectively cleaves heparan sulfate proteoglycans (HSPG), which are ubiquitously expressed in mammals and are known to be involved in regulating the activity of an array of inflammatory mediators. In the present study, we have investigated the effects of human recombinant heparanase, the inactive precursor of this enzyme (proheparanase) and enzymatically inactivated heparanase, on inflammatory cell recruitment in the rat and on human leukocyte-endothelial adhesion in vitro.

View Article and Find Full Text PDF

IgG antibodies have evolved to be flexible so that they can bind to epitopes located over a wide spatial range. The two Fabs in an IgG antibody are linked together as if each Fab is at the end of a linear, flexible molecule. PEG was used as a scaffold molecule to link two Fabs together to give Fab-PEG-Fab molecules, or FpFs.

View Article and Find Full Text PDF

Protein PEGylation is the most clinically validated method to improve the efficacy of protein-based medicines. Antibody fragments such as Fabs display rapid clearance from blood circulation and therefore are good candidates for PEGylation. We have developed PEG-bis-sulfone reagents 1 that can selectively alkylate both sulfurs derived from a native disulfide.

View Article and Find Full Text PDF

Heparin has long been known to possess biological effects that are unrelated to its anticoagulant activity. In particular, much emphasis has been placed upon heparin, or novel agents based upon the heparin template, as potential anti-inflammatory agents. Moreover, heparin has been reported to possess clinical benefit in humans, including in chronic inflammatory diseases and cancer, that are over and above the expected effects on blood coagulation and which in many cases are entirely separable from this role.

View Article and Find Full Text PDF

Objectives: To determine whether the glucagon-like 1 peptide analogue exendin-4 (EX-4) augments the neurochemical effects of a single L-DOPA treatment and whether EX-4 can decrease L-DOPA induced dyskinesias (LIDS).

Methods: Rats were lesioned with 6-hydroxydopamine (6-OHDA) and 7 days later given EX-4 for 7 days. The following day, rats were given L-DOPA and extracellular dopamine was measured.

View Article and Find Full Text PDF

Many neurotropic strains of Escherichia coli cause potentially lethal bacteraemia and meningitis in newborn infants by virtue of their capacity to elaborate the protective polysialic acid (polySia) K1 capsule. Recombinant capsule depolymerase, endosialidase E (endoE), selectively removes polySia from the bacterial surface; when administered intraperitoneally to infected neonatal rats, the enzyme interrupts the transit of E. coli K1 from gut to brain via the blood circulation and prevents death from systemic infection.

View Article and Find Full Text PDF

Heparin is known to possess anti-inflammatory properties that in many cases appear to be separable from its anticoagulant activity. Mast cells, located in tissue, are the sole source of endogenous heparin, which may be involved in control of the inflammatory response. The majority of studies of the effects of heparin on the inflammatory response, carried out to date, have involved systemic administration and the potential influence of heparin in the site of inflammation has been less clear.

View Article and Find Full Text PDF

We have recently observed that the corticotrophin releasing factor (CRF) related peptide urocortin reverses key features of nigrostriatal damage in two paradigms of Parkinson's disease. Here we have studied whether these effects are supported by a retention of striatal basal and evoked extracellular dopamine and the receptor(s) that may mediate this effect. Fourteen days following stereotaxic injections of 6-hydroxydopamine (6-OHDA) or lipopolysaccharide (LPS) and urocortin, extracellular dopamine levels in striata ipsilateral to injection sites of 6-OHDA/LPS and urocortin treated rats were comparable with sham injected rats, whilst rats given 6-OHDA/LPS and vehicle had considerably lower dopamine levels.

View Article and Find Full Text PDF

We have recently observed that the corticotropin releasing factor related peptide urocortin (UCN) reverses key features of nigrostriatal neurodegeneration following intracerebral injection of either 6-hydroxydopamine (6-OHDA) or lipopolysaccharide (LPS). To determine the potential therapeutic utility of UCN here we have studied whether these effects are sustained for several weeks following peptide injection. In addition we have studied whether UCN still shows efficacy in rats with more pronounced nigrostriatal lesions.

View Article and Find Full Text PDF

Background: It has recently become apparent that neuroinflammation may play a significant role in Parkinson's disease (PD). This is also the case in animal paradigms of the disease. The potential neuroprotective action of the glucagon-like peptide 1 receptor (GLP-1R) agonist exendin-4 (EX-4), which is protective against cytokine mediated apoptosis and may stimulate neurogenesis, was investigated In paradigms of PD.

View Article and Find Full Text PDF

We have recently observed that the corticotrophin releasing hormone (CRF) related peptide urocortin (UCN) reverses key features of nigrostriatal damage in the hemiparkinsonian 6-hydroxydopamine lesioned rat. Here we have studied whether similar effects are also evident in the lipopolysaccaride (LPS) neuroinflammatory paradigm of Parkinson's disease (PD). To do this we have measured restoration of normal motor behaviour, retention of nigral dopamine (DA) and also tyrosine hydroxylase (TH) activity.

View Article and Find Full Text PDF

The potential neuroprotective action of the corticotrophin-releasing factor-related peptide urocortin (UCN) was investigated in the rat 6-hydroxydopamine (6-OHDA) and lipopolysaccharide (LPS) paradigms of Parkinson's disease. UCN (20 fmol) was either given at the same time as (T = 0) or 7 days after (T = +7) intracerebral 6-OHDA or LPS injection. At 14 days after 6-OHDA or LPS injection, circling behaviour was measured following apomorphine challenge.

View Article and Find Full Text PDF

Urocortins are members of the corticotropin-releasing factor (CRF) family of peptides that bind to two receptors, CRF(1) and CRF(2). While CRF(1) is a high-affinity receptor for CRF, urocortin III binds with much greater affinity to CRF(2). In the present study we investigated the effect of CRF(2) receptor activation with urocortin III on airway smooth muscle tone in vitro and in an acute model of airway inflammation in mice.

View Article and Find Full Text PDF