Publications by authors named "Helen Grant"

Introduction: Out of hospital cardiac arrest (OHCA) is a common problem. Rates of survival are low and a proportion of survivors are left with an unfavourable neurological outcome. Four models have been developed to predict risk of unfavourable outcome at the time of critical care admission - the Cardiac Arrest Hospital Prognosis (CAHP), MIRACLE, Out of Hospital Cardiac Arrest (OHCA), and Targeted Temperature Management (TTM) models.

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  • The study investigates how climate change factors, specifically reduced snow cover and shrub expansion, affect nutrient cycling in alpine grasslands, which are experiencing warming at twice the global average.
  • The combination of these factors significantly disrupts the seasonal coupling of plant and soil microbial nitrogen cycling, leading to substantial decreases in plant nitrogen uptake and soil microbial biomass during critical seasonal periods.
  • Overall, these disruptions hinder the ability of alpine ecosystems to retain nitrogen and maintain plant productivity, raising concerns for their resilience under ongoing climate change.
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Mephedrone is an illegal drug that is used recreationally. Few studies have been conducted to investigate the mechanisms by which mephedrone is harming cells. In this research, we investigated the effect of mephedrone using toxicology coupled with LC-MS/MS based metabolomics in the two CNS derived cell lines.

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Aims: Elevated blood cobalt levels secondary to metal-on-metal (MoM) hip arthroplasties are a suggested risk factor for developing cardiovascular complications including cardiomyopathy. Clinical studies assessing patients with MoM hips using left ventricular ejection fraction (LVEF) have found conflicting evidence of cobalt-induced cardiomyopathy. Global longitudinal strain (GLS) is an echocardiography measurement known to be more sensitive than LVEF when diagnosing early cardiomyopathies.

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The carbon cycle is a key regulator of Earth's climate. On geological time-scales, our understanding of particulate organic matter (POM), an important upper ocean carbon pool that fuels ecosystems and an integrated part of the carbon cycle, is limited. Here we investigate the relationship of planktonic foraminifera-bound organic carbon isotopes (δC) with δC of POM (δC).

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  • Climate change is affecting mountain ecosystems by reducing winter snow cover, causing earlier spring snowmelt, and leading to shrub expansion in alpine areas.
  • Research shows that changes in snow conditions impact soil microbial communities and function, with these effects lasting into summer.
  • The expansion of ericaceous shrubs alters these impacts, enhancing certain soil microbes while reducing soil respiration and nitrogen availability, indicating that vegetation shifts can influence soil responses to climate change in alpine regions.
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Elevated levels of circulating cobalt ions have been linked with a wide range of systemic complications including neurological, endocrine, and cardiovascular symptoms. Case reports of patients with elevated blood cobalt ions have described significant cardiovascular complications including cardiomyopathy. However, correlation between the actual level of circulating cobalt and extent of cardiovascular injury has not previously been performed.

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In contrast to the situation in plants inhabiting most of the world's ecosystems, mycorrhizal fungi are usually absent from roots of the only two native vascular plant species of maritime Antarctica, Deschampsia antarctica and Colobanthus quitensis. Instead, a range of ascomycete fungi, termed dark septate endophytes (DSEs), frequently colonise the roots of these plant species. We demonstrate that colonisation of Antarctic vascular plants by DSEs facilitates not only the acquisition of organic nitrogen as early protein breakdown products, but also as non-proteinaceous d-amino acids and their short peptides, accumulated in slowly-decomposing organic matter, such as moss peat.

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Exposure to circulating cobalt (Co) in patients with metal-on-metal orthopaedic hip implants has been linked to cardiotoxicity but the underlying mechanism(s) remain undefined. The aim of the current study was to examine the effects of Co on the heart in vivo and specifically on cardiac fibroblasts in vitro. Adult male rats were treated with CoCl (1 mg/kg) for either 7 days or 28 days.

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Development of drug delivery systems (DDS) is essential in many cases to remedy the limitations of free drug molecules. Silica has been of great interest as a DDS due to being more robust and versatile than other types of DDS (e.g.

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Bacterial inactivation by 405 nm light is accredited to the photoexcitation of intracellular porphyrin molecules resulting in energy transfer and the generation of reactive oxygen species that impart cellular oxidative damage. The specific mechanism of cellular damage, however, is not fully understood. Previous work has suggested that destruction of nucleic acids may be responsible for inactivation; however, microscopic imaging has suggested membrane damage as a major constituent of cellular inactivation.

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A series of 47 structurally diverse MGBs, derived from the natural product distamycin, was evaluated for anti-lung cancer activity by screening against the melanoma cancer cell line B16-F10. Five compounds have been found to possess significant activity, more so than a standard therapy, Gemcitabine. Moreover, one compound has been found to have an activity around 70-fold that of Gemcitabine and has a favourable selectivity index of greater than 125.

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Conventional in vitro human hepatic models for drug testing are based on the use of standard cell lines derived from hepatomas or primary human hepatocytes (PHHs). Limited availability, interdonor functional variability and early phenotypic alterations in PHHs restrict their use, whilst standard cell lines such as HepG2 lack a substantial and variable set of liver-specific functions such as CYP450 activity. Alternatives include the HepG2-derivative C3A cells selected as a more differentiated and metabolically active hepatic phenotype.

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Light at wavelength 405 nm is an effective bactericide. Previous studies showed that exposing mammalian cells to 405 nm light at 36 J/cm(2) (a bactericidal dose) had no significant effect on normal cell function, although at higher doses (54 J/cm(2)), mammalian cell death became evident. This research demonstrates that mammalian and bacterial cell toxicity induced by 405 nm light exposure is accompanied by reactive oxygen species production, as detected by generation of fluorescence from 6-carboxy-2',7'-dichlorodihydrofluorescein diacetate.

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Hip resurfacing with cobalt-chromium (CoCr) alloy was developed as a surgical alternative to total hip replacement. However, the biological effects of nanoparticles generated by wear at the metal-on-metal articulating surfaces has limited the success of such implants. The aim of this study was to investigate the effects of the combined exposure to CoCr nanoparticles and cobalt ions released from a resurfacing implant on monocytes (U937 cells) and whether these resulted in morphology changes, proliferation alterations, toxicity and cytokine release.

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Cobalt-chromium (CoCr) particles in the nanometre size range and their concomitant release of Co and Cr ions into the patients' circulation are produced by wear at the articulating surfaces of metal-on-metal (MoM) implants. This process is associated with inflammation, bone loss and implant loosening and led to the withdrawal from the market of the DePuy ASR™ MoM hip replacements in 2010. Ions released from CoCr particles derived from a resurfacing implant in vitro and their subsequent cellular up-take were measured by ICP-MS.

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Healthcare associated infections pose a major threat to patients admitted to hospitals and infection rates following orthopedic arthroplasty surgery are as high as 4%. A 405-nm high-intensity narrow spectrum light has been proven to reduce environmental contamination in hospital isolation rooms, and there is potential to develop this technology for application in arthroplasty surgery. Cultured rat osteoblasts were exposed to varying light intensities and it was found that exposures of up to a dose of 36 J/cm2 had no significant effect on cell viability [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay], function (alkaline phosphatase activity), and proliferation rate (BrdU cell proliferation assay).

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Silica nanoparticles have been shown to have great potential as drug delivery systems (DDS), however, their fabrication often involves harsh chemicals and energy intensive laborious methods. This work details the employment of a bioinspired "green" method for the controlled synthesis of silica, use of the products to entrap and release drug molecules and their cytotoxicity in order to develop novel DDS. Bioinspired silica synthesis occurs at pH 7, room temperature and in less than 5 minutes, resulting in a rapid, cheaper and greener route.

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1. The current study demonstrated that there is still new information to be obtained on the chemical and biological transformation of the widely studied flavonoid quercetin. 2.

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1. The metabolism of ferulic acid (FA) has been studied in a number of different systems and several metabolites of FA have been characterised. No previous work has been carried out using hepatocytes to characterise the metabolism of FA.

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Reconstituted collagen hydrogels are often used for in vitro studies of cell-matrix interaction and as scaffolds for tissue engineering. Understanding the mechanical and transport behaviours of collagen hydrogels is therefore extremely important, albeit difficult due to their very high water content (typically >99.5%).

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Collagen and fibronectin matrices are known to stimulate migration of microvascular endothelial cells and the process of tubulogenesis, but the physical, chemical, and topographical cues for directed vessel formation have yet to be determined. In this study, growth, migration, elongation, and tube formation of human lymphatic microvascular endothelial cells (LECs) were investigated on electrospun poly(D,L-lactic-co-glycolic acid) (PLGA) and poly(L-lactic-co-D-lactic acid) (PLDL) nanofiber-coated substrates, and correlated with fiber density and diameter. Directed migration of LECs was observed in the presence of aligned nanofibers, whereas random fiber alignment slowed down migration and growth of LECs.

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(±)-4'-Methylmethcathinone hydrochloride [(±)-mephedrone, 4-MMC] is a synthetic "legal high", with a classical cathinone structure similar to methcathinone. In this study, the in vitro metabolism of 4-MMC was investigated in Sprague-Dawley rat hepatocytes to characterise the associated Phase I and II metabolites. 4-MMC was incubated with rat liver hepatocytes, and the reaction mixture was analysed on a zwitterionic hydrophilic interaction (ZIC-HILIC) column using LC-MS and LC-MS(2).

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This study used a rodent air-pouch model to assess the acute inflammatory response to cobalt-chromium (CoCr) alloy wear debris from a metal-on-metal hip resurfacing implant that may contribute to joint failure. Air-pouches were injected with either sterile phosphate-buffered saline, 1 μg lipopolysaccharide (LPS) or 2.5 mg CoCr wear debris.

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Metal-on-metal hip replacement implants generate wear debris and release ions both locally and systemically in patients. To investigate dissemination of metal, we determined blood and organ levels of cobalt (Co), chromium (Cr), and molybdenum (Mo) following the implantation of Co-Cr alloy wear debris in mice using skin pouches as a model system. We observed increased metal levels in blood for up to 72 h; the levels of Co were highest and remained elevated for 7 days.

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