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On the mucoadhesive properties of synthetic and natural polyampholytes. J Colloid Interface Sci 2024; 659:849-858. [PMID: 38218088 DOI: 10.1016/j.jcis.2023.12.176] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Revised: 12/06/2023] [Accepted: 12/29/2023] [Indexed: 01/15/2024]
Abstract
HYPOTHESIS The mucoadhesive characteristics of amphoteric polymers (also known as polyampholytes) can vary and are influenced by factors such as the solution's pH and its relative position against their isoelectric point (pHIEP). Whilst the literature contains numerous reports on mucoadhesive properties of either cationic or anionic polymers, very little is known about these characteristics for polyampholytes EXPERIMENTS: Here, two amphoteric polymers were synthesized by reaction of linear polyethylene imine (l-PEI) with succinic or phthalic anhydride and their mucoadhesive properties were compared to bovine serum albumin (BSA), selected as a natural polyampholyte. Interactions between these polymers and porcine gastric mucin were studied using turbidimetric titration and isothermal titration calorimetry across a wide range of pHs. Model tablets were designed, coated with these polymers and tested to evaluate their adhesion to porcine gastric mucosa at different pHs. Moreover, a retention study using fluorescein isothiocyanate (FITC)-labelled polyampholytes deposited onto mucosal surfaces was also conducted FINDINGS: All these studies indicated the importance of solution pH and its relative position against pHIEP in the mucoadhesive properties of polyampholytes. Both synthetic and natural polyampholytes exhibited strong interactions with mucin and good mucoadhesive properties at pH < pHIEP.
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Gut bacteria promote proliferation in benign S/RG/C2 colorectal tumour cells, and promote proliferation, migration and invasion in malignant HCT116 cells. Sci Rep 2023; 13:17291. [PMID: 37828235 PMCID: PMC10570319 DOI: 10.1038/s41598-023-44130-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Accepted: 10/04/2023] [Indexed: 10/14/2023] Open
Abstract
Colorectal cancer (CRC) is a significant global health burden with a rising incidence worldwide. Distinct bacterial populations are associated with CRC development and progression, and it is thought that the relationship between CRC and associated gut bacteria changes during the progression from normal epithelium to benign adenoma and eventually malignant carcinoma and metastasis. This study compared the interaction of CRC-associated species Enterotoxigenic Bacteroides fragilis, Enterococcus faecalis and Fusobacterium nucleatum and one probiotic species, Escherichia coli Nissle 1917 with a colorectal adenoma (S/RG/C2) and a colorectal adenocarcinoma (HCT116) derived cell line. Gentamicin protection assays showed that all species displayed higher attachment to benign tumour monolayers when compared to malignant monolayers. However, invasion of 3/4 species was higher in the HCT116 cells than in the adenoma cells. All species were found to persist within tumour cell monolayers for a minimum of 48 h under standard aerobic cell culture conditions, with persistence significantly higher in HCT116 cells. Downstream assays were performed to analyse the behaviour of S/RG/C2 and HCT116 cells post-infection and revealed that all species increased the tumour cell yield of both cell lines. The migratory and invasive potential of HCT116 cells was increased after infection with F. nucleatum; however, no species significantly altered these characteristics in S/RG/C2 cells. These results add to the growing evidence for the involvement of microorganisms in CRC progression and suggest that these interactions may be dependent on tumour cell-specific characteristics.
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Common microRNA regulated pathways in Alzheimer's and Parkinson's disease. Front Neurosci 2023; 17:1228927. [PMID: 37719162 PMCID: PMC10502311 DOI: 10.3389/fnins.2023.1228927] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Accepted: 08/02/2023] [Indexed: 09/19/2023] Open
Abstract
MicroRNAs (miRNAs) are small non-coding RNAs involved in gene regulation. Recently, miRNA dysregulation has been found in neurodegenerative diseases such as Alzheimer's disease (AD) and Parkinson's disease (PD). The diagnosis of Alzheimer's and Parkinson's is currently challenging, mainly occurring when pathology is already present, and although treatments are available for both diseases, the role of treatment is primarily to prevent or delay the progress of the diseases instead of fully overcoming the diseases. Therefore, the challenge in the near future will be to determine effective drugs to tackle the dysregulated biological pathways in neurodegenerative diseases. In the present study, we describe the dysregulation of miRNAs in blood of Alzheimer's and Parkinson's patients with the aim to identify common mechanisms between the 2 pathologies and potentially to identify common therapeutic targets which can stop or delay the progression of two most frequent neuropathologies. Two independent systematic reviews, bioinformatic analysis, and experiment validation were performed to identify whether AD and PD share common pathways. A total of 15 common miRNAs were found in the literature and 13 common KEGG pathways. Among the common miRNAs, two were selected for validation in a small cohort of AD and PD patients. Let-7f-5p and miR-29b-3p showed to be good predictors in blood of PD patients.
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Transdermal drug delivery in horses: An in vitro comparison of skin structure and permeation of two model drugs at various anatomical sites. Vet Dermatol 2023. [PMID: 37185892 DOI: 10.1111/vde.13162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Revised: 02/10/2023] [Accepted: 03/28/2023] [Indexed: 05/17/2023]
Abstract
BACKGROUND Oral and parenteral drug delivery in horses can be difficult. Equine-specific transdermal drug formulations offer improved ease of treatment; development of such formulations requires a deeper understanding of the structural and chemical tissue barrier of horse skin. HYPOTHESIS/OBJECTIVES To compare the structural composition and barrier properties of equine skin. ANIMALS Six warmblood horses (two males, four females) with no skin diseases. MATERIALS AND METHODS Routine histological and microscopic analyses were carried out with image analysis for skin from six different anatomical locations. In vitro drug permeation was analysed using a standard Franz diffusion cell protocol coupled with reversed phase-high-performance liquid chromatography detailing flux, lag times and tissue partitioning ratios of two model drug compounds. RESULTS Epidermal and dermal thicknesses varied between sites. The dermal and epidermal thicknesses of the croup were 1764 ± 115 μm and 36 ± 3.6 μm, respectively, and were significantly different (p < 0.05) from the inner thigh thicknesses which were 824 ± 35 μm and 49 ± 3.6 μm. Follicular density and size also varied. The highest flux for the model hydrophilic molecule (caffeine) was for the flank (3.22 ± 0.36 μg/cm2 /h), while that for the lipophilic molecule (ibuprofen) was for the inner thigh (0.12 ± 0.02 μg/cm2 /h). CONCLUSIONS AND CLINICAL RELEVANCE Anatomical location differences in equine skin structure and small molecule permeability were demonstrated. These results can aid in the development of transdermal therapies for horses.
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A Brief Overview: Sex Differences in Prevalent Chronic Musculoskeletal Conditions. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2023; 20:4521. [PMID: 36901530 PMCID: PMC10001545 DOI: 10.3390/ijerph20054521] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 01/25/2023] [Accepted: 02/24/2023] [Indexed: 06/18/2023]
Abstract
Musculoskeletal (MSK) pain disorders are some of the most prevalent and disabling chronic pain conditions worldwide. These chronic conditions have a considerable impact on the quality of life of individuals, families, communities, and healthcare systems. Unfortunately, the burden of MSK pain disorders does not fall equally across the sexes. Females consistently demonstrate more prevalent and severe clinical presentations of MSK disorders, and this disparity increases in magnitude with age. The aim of the present article is to review recent studies that have examined sex differences between males and females in four of the most common MSK pain disorders: neck pain, low back pain, osteoarthritis, and rheumatoid arthritis.
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Synthesis and Evaluation of Poly(3-hydroxypropyl Ethylene-imine) and Its Blends with Chitosan Forming Novel Elastic Films for Delivery of Haloperidol. Pharmaceutics 2022; 14:pharmaceutics14122671. [PMID: 36559165 PMCID: PMC9785711 DOI: 10.3390/pharmaceutics14122671] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2022] [Revised: 11/24/2022] [Accepted: 11/26/2022] [Indexed: 12/03/2022] Open
Abstract
This study aimed to develop novel elastic films based on chitosan and poly(3-hydroxypropyl ethyleneimine) or P3HPEI for the rapid delivery of haloperidol. P3HPEI was synthesized using a nucleophilic substitution reaction of linear polyethyleneimine (L-PEI) with 3-bromo-1-propanol. 1H-NMR and FTIR spectroscopies confirmed the successful conversion of L-PEI to P3HPEI, and the physicochemical properties and cytotoxicity of P3HPEI were investigated. P3HPEI had good solubility in water and was significantly less toxic than the parent L-PEI. It had a low glass transition temperature (Tg = -38.6 °C). Consequently, this new polymer was blended with chitosan to improve mechanical properties, and these materials were used for the rapid delivery of haloperidol. Films were prepared by casting from aqueous solutions and then evaporating the solvent. The miscibility of polymers, mechanical properties of blend films, and drug release profiles from these formulations were investigated. The blends of chitosan and P3HPEI were miscible in the solid state and the inclusion of P3HPEI improved the mechanical properties of the films, producing more elastic materials. A 35:65 (%w/w) blend of chitosan-P3HPEI provided the optimum glass transition temperature for transmucosal drug delivery and so was selected for further investigation with haloperidol, which was chosen as a model hydrophobic drug. Microscopic and X-ray diffractogram (XRD) data indicated that the solubility of the drug in the films was ~1.5%. The inclusion of the hydrophilic polymer P3HPEI allowed rapid drug release within ~30 min, after which films disintegrated, demonstrating that the formulations are suitable for application to mucosal surfaces, such as in buccal drug delivery. Higher release with increasing drug loading allows flexible dosing. Blending P3HPEI with chitosan thus allows the selection of desirable physicochemical and mechanical properties of the films for delivery of haloperidol as a poorly water-soluble drug.
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Physically Cross-Linked Cryogels of Linear Polyethyleneimine: Influence of Cooling Temperature and Solvent Composition. Macromolecules 2022. [DOI: 10.1021/acs.macromol.2c01308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Smartphone mindfulness meditation training reduces Pro-inflammatory gene expression in stressed adults: A randomized controlled trial. Brain Behav Immun 2022; 103:171-177. [PMID: 35427760 DOI: 10.1016/j.bbi.2022.04.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 03/29/2022] [Accepted: 04/01/2022] [Indexed: 10/18/2022] Open
Abstract
Mindfulness meditation training has been shown to be an effective stress reduction strategy, but less is known about its immunoregulatory impact. In a randomized controlled trial of stressed customer service workers, the present study tested whether a 30-day smartphone-based mindfulness meditation training program (compared to a problem-solving control program) would affect pro-inflammatory gene expression. Both interventions led to reductions in stress levels, but there was no difference in stress reduction between conditions. Consistent with predictions, mindfulness training reduced activity of the pro-inflammatory NF-κB transcription control pathway compared to the active control. These results suggest that mindfulness training may be a particularly effective method for improving immune cell gene expression in stressful work environments.
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Accelerating topical formulation development for inflammatory dermatoses; an ex vivo human skin culture model consistent with clinical therapeutics. Int J Pharm 2022; 618:121648. [PMID: 35276230 DOI: 10.1016/j.ijpharm.2022.121648] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 03/02/2022] [Accepted: 03/05/2022] [Indexed: 11/24/2022]
Abstract
Although animal models have been extensively used to evaluate human topical therapeutics, they exhibit marked physiological differences to human skin. Our objective was to develop a human ex vivo skin culture model to explore the pathophysiology of inflammatory dermatoses and for preclinical testing of potential therapeutic treatments. Ex vivo skin barrier integrity and metabolic activity was retained for 5 days and stimulation of T-helper cells (Th1), which produce proinflammatory cytokines, provided inflammatory responses similar to those reported from in vivo biopsy. Tissue responses to established therapies of pimecrolimus (Elidel) and clobetasol propionate (Dermovate) were evaluated using the human ex vivo skin culture, assessing pharmacodynamic changes in gene expression alongside the pharmacokinetics of drug penetration with both products showing time dependent efficacies. The translational utility of the human ex vivo skin culture model of inflammatory dermatoses was demonstrated through comparison with an in vivo clinical study, with similar reductions in inflammatory gene expression recorded for both drug treatments. Thus, this model can reduce, replace or refine animal testing and also mitigate the risk of failure in costly and time-consuming clinical trials associated with novel topical therapeutic development.
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Landscape characteristics influence ranging behavior of Asian elephants at the human-wildlands interface in Myanmar. MOVEMENT ECOLOGY 2022; 10:6. [PMID: 35123584 PMCID: PMC8818246 DOI: 10.1186/s40462-022-00304-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Accepted: 01/26/2022] [Indexed: 06/14/2023]
Abstract
CONTEXT Asian elephant numbers are declining across much of their range driven largely by serious threats from land use change resulting in habitat loss and fragmentation. Myanmar, holding critical range for the species, is undergoing major developments due to recent sociopolitical changes. To effectively manage and conserve the remaining populations of endangered elephants in the country, it is crucial to understand their ranging behavior. OBJECTIVES Our objectives were to (1) estimate the sizes of dry, wet, and annual ranges of wild elephants in Myanmar; and quantify the relationship between dry season (the period when human-elephant interactions are the most likely to occur) range size and configurations of agriculture and natural vegetation within the range, and (2) evaluate how percentage of agriculture within dry core range (50% AKDE range) of elephants relates to their daily distance traveled. METHODS We used autocorrelated kernel density estimator (AKDE) based on a continuous-time movement modeling (ctmm) framework to estimate dry season (26 ranges from 22 different individuals), wet season (12 ranges from 10 different individuals), and annual range sizes (8 individuals), and reported the 95%, 50% AKDE, and 95% Minimum Convex Polygon (MCP) range sizes. We assessed how landscape characteristics influenced range size based on a broad array of 48 landscape metrics characterizing aspects of vegetation, water, and human features and their juxtaposition in the study areas. To identify the most relevant landscape metrics and simplify our candidate set of informative metrics, we relied on exploratory factor analysis and Spearman's rank correlation coefficient. Based on this analysis we adopted a final set of metrics into our regression analysis. In a multiple regression framework, we developed candidate models to explain the variation in AKDE dry season range sizes based on the previously identified, salient metrics of landscape composition. RESULTS Elephant dry season ranges were highly variable averaging 792.0 km2 and 184.2 km2 for the 95% and 50% AKDE home ranges, respectively. We found both the shape and spatial configuration of agriculture and natural vegetation patches within an individual elephant's range play a significant role in determining the size of its range. We also found that elephants are moving more (larger energy expenditure) in ranges with higher percentages of agricultural area. CONCLUSION Our results provide baseline information on elephant spatial requirements and the factors affecting them in Myanmar. This information is important for advancing future land use planning that takes into account space-use requirements for elephants. Failing to do so may further endanger already declining elephant populations in Myanmar and across the species' range.
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A Novel Polymer Insect Repellent Conjugate for Extended Release and Decreased Skin Permeation of Para-Menthane-3,8-Diol. Pharmaceutics 2021; 13:403. [PMID: 33803662 PMCID: PMC8002994 DOI: 10.3390/pharmaceutics13030403] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 03/11/2021] [Accepted: 03/12/2021] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND We developed a novel polymer insect repellent conjugate for extended release and decreased skin permeation of the volatile insect repellent p-menthane-3,8-diol (PMD). METHODS PMD was conjugated with acryloyl chloride via an ester bond to form acryloyl-PMD, which was subsequently copolymerised with acrylic acid at varying molar ratios. Copolymer structures were characterised by 1H NMR and FT-IR, analysed by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), molecular weights and reactivity ratios determined, and repellent loading assessed. RESULTS Using porcine liver esterases, ~45% of the insect repellent was released over five days. Penetration and permeation studies of the copolymer and free repellent using excised, full-thickness porcine ear skin showed no detectable permeation of the copolymer through skin compared to the PMD. Moreover, tape stripping revealed that over 90% of the copolymer remained on the outer surface of the skin, whereas free PMD was within all skin layers. A planarian toxicity fluorescence assay indicated that that the copolymer is unlikely to be a significant irritant when applied topically. CONCLUSIONS this study demonstrates the feasibility of the copolymer approach to develop extended-release insect repellents while reducing skin uptake and transdermal permeation of the small-molecular-weight active ingredient, in order to minimise any adverse effects.
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Thiolated and PEGylated silica nanoparticle delivery to hair follicles. Int J Pharm 2021; 593:120130. [PMID: 33264642 DOI: 10.1016/j.ijpharm.2020.120130] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Revised: 11/23/2020] [Accepted: 11/25/2020] [Indexed: 02/07/2023]
Abstract
Targeting drug delivery to hair follicles is valuable to treat conditions such as alopecia's and acne, and this shunt route may also allow drug delivery to deeper skin layers and the systemic circulation by avoiding the intact stratum corneum. Here, we investigated the effects of nanoparticle surface chemistry on their delivery into hair follicles by synthesizing fluorescent thiolated silica nanoparticles and functionalizing with 750 Da and 5000 Da methoxypolyethylene glycol maleimide (PEG). The stability of the nanoparticles in skin homogenate was verified before tape stripping of porcine-dosed tissue showed the distribution of the free fluorescent dye and different nanoparticles in the skin. Analysis of microscopic images of the skin sections revealed penetration of nanoparticles functionalized with PEG into the appendages whereas thiolated nanoparticles stayed on the surface of the skin and were removed by tape stripping. Nanoparticles functionalized with PEG 5000 Da penetrated deeper into the hair follicles compared to counterparts functionalized with PEG 750 Da. PEGylation can thus enhance targeted delivery of nanoparticulates into hair follicles.
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Human skin explant model for the investigation of topical therapeutics. Sci Rep 2020; 10:21192. [PMID: 33273665 PMCID: PMC7712775 DOI: 10.1038/s41598-020-78292-4] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Accepted: 11/23/2020] [Indexed: 12/16/2022] Open
Abstract
The development of in vitro and ex vivo models to mimic human illness is important not only for scientific understanding and investigating therapeutic approaches but also to mitigate animal testing and bridge the inter-species translational gap. While in vitro models can facilitate high-throughput and cost-efficient evaluation of novel therapeutics, more complex ex vivo systems can better predict both desirable and adverse in vivo effects. Here we describe an ex vivo cultured human skin explant model in which we have characterized pathological tissue integrity, barrier function and metabolic stability over time. Our findings suggest that human skin can be successfully cultured for pharmacodynamic use up to and beyond 9 days without any adverse physiological consequence.
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Factors associated with advanced colorectal cancer differ between young and older adults in England: a population-based cohort study. Colorectal Dis 2020; 22:2087-2097. [PMID: 32926531 DOI: 10.1111/codi.15361] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Revised: 07/27/2020] [Accepted: 08/31/2020] [Indexed: 12/23/2022]
Abstract
AIM Advanced stage presentation of colorectal cancer is associated with poorer survival outcomes, particularly among young adults. This study aimed to determine whether demographic risk factors for advanced stage presentation differed between young and older adults. METHOD Individual-level data on all incident colorectal cancers in people aged 20 years and above were extracted from the National Cancer Registration and Analysis Service database for the years 2012 to 2015. Patients were divided into two cohorts: young-onset colorectal cancer (YOCC) if aged 20-49 years and older-onset colorectal cancer (OOCC) if aged 50 years and above. Logistic regression was used to identify risk factors for advanced stage presentation, defined as TNM Stage III or IV, in each cohort. RESULTS There were 7075 (5.2%) patients in the YOCC cohort and 128 345 (94.8%) patients in the OOCC cohort. Tumours in the YOCC cohort were more likely to be at an advanced stage (67.2% vs 55.3%, P < 0.001) and located distally (63.7% vs 55.4%, P < 0.001). No demographic factor was consistently associated with advanced stage presentation in the YOCC cohort. Among the OOCC cohort, increased social deprivation [OR (Index of Multiple Deprivation quintile 5 vs 1) = 1.11 (95% CI 1.07-1.16), P < 0.001], Black/Black British ethnicity [OR (baseline White) = 1.25 (95% CI 1.11-1.40), P < 0.001] and residence in the East Midlands [OR (baseline London) = 1.11 (95% CI 1.04-1.17), P = 0.001] were associated with advanced stage presentation. CONCLUSION Demographic factors associated with advanced disease were influenced by age. The effects of social deprivation and ethnicity were only observed in older adults and mirror trends in screening uptake. Targeted interventions for high-risk groups are warranted.
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Planarian toxicity fluorescent assay: A rapid and cheap pre-screening tool for potential skin irritants. Toxicol In Vitro 2020; 69:105004. [PMID: 33010358 DOI: 10.1016/j.tiv.2020.105004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 08/19/2020] [Accepted: 09/14/2020] [Indexed: 01/23/2023]
Abstract
Here we report a new planarian (Dugesia lugubris) fluorescent assay as a rapid and cheap pre-screening tool to predict strong skin irritants. Our aim was to provide a simple and cost-effective in vivo method that avoided use of higher vertebrates. Adapting previously reported methods for planaria mobility alongside an acute toxicity assay, different irritants at five concentrations (0.1%, 0.05%, 0.025%, 0.01% and 0.005% w/v) were tested but both methods failed to discriminate the irritation potential of the test compounds. Therefore, a new alternative fluorescence assay was developed, hypothesising that increasing damage from the irritant to the planarian outer protective membrane will increase accumulation of sodium fluorescein in the flatworm. Fourteen test chemicals were selected representing strong, moderate, mild and non-irritants. In general, results showed increasing sodium fluorescein accumulation within planaria following acute exposure to increasingly strong skin irritants; on exposure to the strong irritants, benzalkonium chloride, citronellal, methyl palmitate, 1-bromohexane and carvacrol, fluorescence within the planaria was significantly greater (P < 0.05) than the negative controls and the common non-irritants PEG-400, dipropylene glycol and isopropyl alcohol; fluorescence values of planaria tested with negative controls and non-irritants were not significantly different. For all test compounds, Fluorescence Intensity of the planaria was compared with literature Primary Irritation Index data and generated a statistically significant (P < 0.005) Pearson correlation (r) of 0.87. Thus, the planarian fluorescent assay is a promising tool for rapid early testing of potential strong skin irritants, and non-irritants, and avoids use of higher vertebrate models.
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Nicotinamide restricts neural precursor proliferation to enhance catecholaminergic neuronal subtype differentiation from mouse embryonic stem cells. PLoS One 2020; 15:e0233477. [PMID: 32925933 PMCID: PMC7489539 DOI: 10.1371/journal.pone.0233477] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2020] [Accepted: 08/28/2020] [Indexed: 11/19/2022] Open
Abstract
Emerging evidence indicates that a strong relationship exists between brain regenerative therapies and nutrition. Early life nutrition plays an important role during embryonic brain development, and there are clear consequences to an imbalance in nutritional factors on both the production and survival of mature neuronal populations and the infant’s risk of diseases in later life. Our research and that of others suggest that vitamins play a fundamental role in the formation of neurons and their survival. There is a growing body of evidence that nicotinamide, the water-soluble amide form of vitamin B3, is implicated in the conversion of pluripotent stem cells to clinically relevant cells for regenerative therapies. This study investigated the ability of nicotinamide to promote the development of mature catecholaminergic neuronal populations (associated with Parkinson’s disease) from mouse embryonic stem cells, as well as investigating the underlying mechanisms of nicotinamide’s action. Nicotinamide selectively enhanced the production of tyrosine hydroxylase-expressing neurons and serotonergic neurons from mouse embryonic stem cell cultures (Sox1GFP knock-in 46C cell line). A 5-Ethynyl-2´-deoxyuridine (EdU) assay ascertained that nicotinamide, when added in the initial phase, reduced cell proliferation. Nicotinamide drove tyrosine hydroxylase-expressing neuron differentiation as effectively as an established cocktail of signalling factors, reducing the proliferation of neural progenitors and accelerating neuronal maturation, neurite outgrowth and neurotransmitter expression. These novel findings show that nicotinamide enhanced and enriched catecholaminergic differentiation and inhibited cell proliferation by directing cell cycle arrest in mouse embryonic stem cell cultures, thus driving a critical neural proliferation-to-differentiation switch from neural progenitors to neurons. Further research into the role of vitamin metabolites in embryogenesis will significantly advance cell-based regenerative medicine, and help realize their role as crucial developmental signalling molecules in brain development.
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Nicotinamide N-Methyltransferase: Genomic Connection to Disease. Int J Tryptophan Res 2020; 13:1178646920919770. [PMID: 32547055 PMCID: PMC7273554 DOI: 10.1177/1178646920919770] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2019] [Accepted: 03/24/2020] [Indexed: 12/20/2022] Open
Abstract
Single-nucleotide polymorphisms (SNPs) in and around the nicotinamide
N-methyltransferase (NNMT) gene are associated with a range
of cancers and other diseases and conditions. The data on these associations
have been assembled, and their strength discussed. There is no evidence that the
presence of either the major or minor base in any SNP affects the expression of
nicotinamide N-methyltransferase. Nevertheless, suggestions
have been put forward that some of these SNPs do affect NNMT expression and thus
homocysteine metabolism. An alternative idea involving non-coding messenger RNAs
(mRNAs) is suggested as a possible mechanism whereby health is influenced. It is
postulated that these long, non-coding NNMT mRNAs may exert deleterious effects
by interfering with the expression of other genes. Neither hypothesis, however,
has experimental proof, and further work is necessary to elucidate NNMT genetic
interactions.
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Abstract
Nicotinamide homeostasis is a candidate common denominator to explain smooth transitions, whether demographic, epidemiological or economic. This 'NAD world', dependent on hydrogen-based energy, is not widely recognised as it is neither measured nor viewed from a sufficiently multi-genomic or historical perspective. Reviewing the importance of meat and nicotinamide balances during our co-evolution, recent history suggests that populations only modernise and age well with low fertility on a suitably balanced diet. Imbalances on the low meat side lead to an excess of infectious disease, short lives and boom-bust demographics. On the high side, meat has led to an excess of degenerative, allergic and metabolic disease and low fertility. A 'Goldilocks' diet derived from mixed and sustainable farming (preserving the topsoil) allows for high intellectual capital, height and good health with controlled population growth resulting in economic growth and prosperity. Implementing meat equity worldwide could lead to progress for future generations on 'spaceship' earth by establishing control over population quality, thermostat and biodiversity, if it is not already too late.
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Demographic trends in the incidence of young-onset colorectal cancer: a population-based study. Br J Surg 2020; 107:595-605. [PMID: 32149386 PMCID: PMC7155067 DOI: 10.1002/bjs.11486] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2019] [Revised: 11/18/2019] [Accepted: 11/27/2019] [Indexed: 12/13/2022]
Abstract
Background Evidence is emerging that the incidence of colorectal cancer is increasing in young adults, but the descriptive epidemiology required to better understand these trends is currently lacking. Methods A population‐based cohort study was carried out including all adults aged 20–49 years diagnosed with colorectal cancer in England between 1974 and 2015. Data were extracted from the National Cancer Registration and Analysis Service database using ICD‐9/10 codes for colorectal cancer. Temporal trends in age‐specific incidence rates according to sex, anatomical subsite, index of multiple deprivation quintile and geographical region were analysed using Joinpoint regression. Results A total of 56 134 new diagnoses of colorectal cancer were analysed. The most sustained increase in incidence rate was in the group aged 20–29 years, which was mainly driven by a rise in distal tumours. The magnitude of incident rate increases was similar in both sexes and across Index of Multiple Deprivation quintiles, although the most pronounced increases in incidence occurred in the southern regions of England. Conclusion Colorectal cancer should no longer be considered a disease of older people. Changes in incidence rates should be used to inform future screening policy, preventative strategies and research agendas, as well as increasing public understanding that younger people need to be aware of the symptoms of colorectal cancer.
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Bradykinesia Is Driven by Cumulative Beta Power During Continuous Movement and Alleviated by Gabaergic Modulation in Parkinson's Disease. Front Neurol 2019; 10:1298. [PMID: 31920922 PMCID: PMC6933612 DOI: 10.3389/fneur.2019.01298] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Accepted: 11/25/2019] [Indexed: 01/22/2023] Open
Abstract
Spontaneous and "event-related" motor cortex oscillations in the beta (15-30 Hz) frequency range are well-established phenomena. However, the precise functional significance of these features is uncertain. An understanding of the specific function is of importance for the treatment of Parkinson's disease (PD), where attenuation of augmented beta throughout the motor network coincides with functional improvement. Previous research using a discrete movement task identified normalization of elevated spontaneous beta and postmovement beta rebound following GABAergic modulation. Here, we explore the effects of the gamma-aminobutyric acid type A modulator, zolpidem, on beta power during the performance of serial movement in 17 (15M, 2F; mean age, 66 ± 6.3 years) PD patients, using a repeated-measures, double-blinded, randomized, placebo-control design. Motor symptoms were monitored before and after treatment, using time-based Unified Parkinson's Disease Rating Scale measurements and beta oscillations in primary motor cortex (M1) were measured during a serial-movement task, using magnetoencephalography. We demonstrate that a cumulative increase in M1 beta power during a 10-s tapping trial is reduced following zolpidem, but not placebo, which is accompanied by an improvement in movement speed and efficacy. This work provides a clear mechanism for the generation of abnormally elevated beta power in PD and demonstrates that perimovement beta accumulation drives the slowing, and impaired initiation, of movement. These findings further indicate a role for GABAergic modulation in bradykinesia in PD, which merits further exploration as a therapeutic target.
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Serotonin Syndrome: Pathophysiology, Clinical Features, Management, and Potential Future Directions. Int J Tryptophan Res 2019; 12:1178646919873925. [PMID: 31523132 PMCID: PMC6734608 DOI: 10.1177/1178646919873925] [Citation(s) in RCA: 72] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Accepted: 08/13/2019] [Indexed: 12/18/2022] Open
Abstract
Serotonin syndrome (SS) (also referred to as serotonin toxicity) is a potentially life-threatening drug-induced toxidrome associated with increased serotonergic activity in both the peripheral (PNS) and central nervous systems (CNS). It is characterised by a dose-relevant spectrum of clinical findings related to the level of free serotonin (5-hydroxytryptamine [5-HT]), or 5-HT receptor activation (predominantly the 5-HT1A and 5-HT2A subtypes), which include neuromuscular abnormalities, autonomic hyperactivity, and mental state changes. Severe SS is only usually precipitated by the simultaneous initiation of 2 or more serotonergic drugs, but the syndrome can also occur after the initiation of a single serotonergic drug in a susceptible individual, the addition of a second or third agent to long-standing doses of a maintenance serotonergic drug, or after an overdose. The combination of a monoamine oxidase inhibitor (MAOI), in particular MAO-A inhibitors that preferentially inhibit the metabolism of 5-HT, with serotonergic drugs is especially dangerous, and may lead to the most severe form of the syndrome, and occasionally death. This review describes our current understanding of the pathophysiology, clinical presentation and management of SS, and summarises some of the drugs and interactions that may precipitate the condition. We also discuss the newer novel psychoactive substances (NPSs), a growing public health concern due to their increased availability and use, and their potential risk to evoke the syndrome. Finally, we discuss whether the inhibition of tryptophan hydroxylase (TPH), in particular the neuronal isoform (TPH2), may provide an opportunity to pharmacologically target central 5-HT synthesis, and so develop new treatments for severe, life-threatening SS.
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Nicotinamide and Demographic and Disease transitions: Moderation is Best. Int J Tryptophan Res 2019; 12:1178646919855940. [PMID: 31320805 PMCID: PMC6610439 DOI: 10.1177/1178646919855940] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Accepted: 05/03/2019] [Indexed: 12/13/2022] Open
Abstract
Good health and rapid progress depend on an optimal dose of nicotinamide. Too little meat triggers the neurodegenerative condition pellagra and tolerance of symbionts such as tuberculosis (TB), risking dysbioses and impaired resistance to acute infections. Nicotinamide deficiency is an overlooked diagnosis in poor cereal-dependant economies masquerading as 'environmental enteropathy' or physical and cognitive stunting. Too much meat (and supplements) may precipitate immune intolerance and autoimmune and allergic disease, with relative infertility and longevity, via the tryptophan-nicotinamide pathway. This switch favours a dearth of regulatory T (Treg) and an excess of T helper cells. High nicotinamide intake is implicated in cancer and Parkinson's disease. Pro-fertility genes, evolved to counteract high-nicotinamide-induced infertility, may now be risk factors for degenerative disease. Moderation of the dose of nicotinamide could prevent some common diseases and personalised doses at times of stress or, depending on genetic background or age, may treat some other conditions.
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Nicotinamide as Independent Variable for Intelligence, Fertility, and Health: Origin of Human Creative Explosions? Int J Tryptophan Res 2019; 12:1178646919855944. [PMID: 31258332 PMCID: PMC6585247 DOI: 10.1177/1178646919855944] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Accepted: 05/03/2019] [Indexed: 12/28/2022] Open
Abstract
Meat and nicotinamide acquisition was a defining force during the 2-million-year evolution of the big brains necessary for, anatomically modern, Homo sapiens to survive. Our next move was down the food chain during the Mesolithic 'broad spectrum', then horticultural, followed by the Neolithic agricultural revolutions and progressively lower average 'doses' of nicotinamide. We speculate that a fertility crisis and population bottleneck around 40 000 years ago, at the time of the Last Glacial Maximum, was overcome by Homo (but not the Neanderthals) by concerted dietary change plus profertility genes and intense sexual selection culminating in behaviourally modern Homo sapiens. Increased reliance on the 'de novo' synthesis of nicotinamide from tryptophan conditioned the immune system to welcome symbionts, such as TB (that excrete nicotinamide), and to increase tolerance of the foetus and thereby fertility. The trade-offs during the warmer Holocene were physical and mental stunting and more infectious diseases and population booms and busts. Higher nicotinamide exposure could be responsible for recent demographic and epidemiological transitions to lower fertility and higher longevity, but with more degenerative and auto-immune disease.
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Nicotinamide's Ups and Downs: Consequences for Fertility, Development, Longevity and Diseases of Poverty and Affluence. Int J Tryptophan Res 2018; 11:1178646918802289. [PMID: 30327578 PMCID: PMC6178124 DOI: 10.1177/1178646918802289] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Accepted: 08/27/2018] [Indexed: 01/19/2023] Open
Abstract
To further explore the role of dietary nicotinamide in both brain development and diseases, particularly those of ageing. Articles cover neurodegenerative disease and cancer. Also discussed are the effects of nicotinamide, contained in meat and supplements and derived from symbionts, on the major transitions of disease and fertility from ancient times up to the present day. A key role for the tryptophan - NAD 'de novo' and immune tolerance pathway are discussed at length in the context of fertility and longevity and the transitions from immune paresis to Treg-mediated immune tolerance and then finally to intolerance and their associated diseases. Abstract: Nicotinamide in human evolution increased cognitive power in a positive feedback loop originally involving hunting. As the precursor to metabolic master molecule NAD it is, as vitamin B3, vital for health. Paradoxically, a lower dose on a diverse plant then cereal-based diet fuelled population booms from the Mesolithic onwards, by upping immune tolerance of the foetus. Increased tolerance of risky symbionts, whether in the gut or TB, that excrete nicotinamide co-evolved as buffers for when diet was inadequate. High biological fertility, despite disease trade-offs, avoided the extinction of Homo sapiens and heralded the dawn of a conscious, creative, and pro-fertility culture. Nicotinamide equity now would stabilise populations and prevent NAD-based diseases of poverty and affluence.
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Improved crystal structure solution from powder diffraction data by the use of conformational information. Acta Crystallogr A Found Adv 2018. [DOI: 10.1107/s0108767318097003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Controlling the Size of Thiolated Organosilica Nanoparticles. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:8347-8354. [PMID: 29909627 DOI: 10.1021/acs.langmuir.8b01556] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Nanoparticle characteristics, including their size, are governed by the reagents employed and the reaction parameters. Here, we systemically vary the catalyst, oxygen content, temperature, and solvent to modify the size and zeta-potential of thiolated organosilica nanoparticles. The particles were synthesized by self-condensation of 3-mercaptopropyltrimethoxysilane in a range of organic solvents in contact with oxygen, with NaOH and other catalysts. The particle size increased with increasing reaction temperature (70 ± 1 nm at 50 °C; 50 ± 1 nm at room temperature) but decreased when air was bubbled through the reaction mixture compared to no bubbling. A significant decrease in the particle size was seen when increasing the dielectric constant of the solvent and when increasing the catalyst concentration; from these, we provide empirical equations that can be used to design particle sizes by manipulating the dielectric constant of the solvent (or cosolvents) or by varying the NaOH catalyst concentration when dimethylsulfoxide is the selected solvent.
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Bioaccessibility of PBDEs present in indoor dust: A novel dialysis membrane method with a Tenax TA® absorption sink. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 621:1-8. [PMID: 29175617 DOI: 10.1016/j.scitotenv.2017.11.097] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Revised: 10/26/2017] [Accepted: 11/08/2017] [Indexed: 06/07/2023]
Abstract
Human uptake of flame retardants (FRs) such as polybrominated diphenyl ethers (PBDEs) via indoor dust ingestion is commonly considered as 100% bioaccessible, leading to potential risk overestimation. Here, we present a novel in vitro colon-extended physiologically-based extraction test (CE-PBET) with Tenax TA® as an absorptive "sink" capable to enhance PBDE gut bioaccessibility. A cellulose-based dialysis membrane (MW cut-off 3.5kDa) with high pH and temperature tolerance was used to encapsulate Tenax TA®, facilitating efficient physical separation between the absorbent and the dust, while minimizing re-absorption of the ingested PBDEs to the dust particles. As a proof of concept, PBDE-spiked indoor dust samples (n=3) were tested under four different conditions; without any Tenax TA® addition (control) and with three different Tenax TA® loadings (i.e. 0.25, 0.5 or 0.75g). Our results show that in order to maintain a constant sorptive gradient for the low MW PBDEs, 0.5g of Tenax TA® are required in CE-PBET. Tenax TA® inclusion (0.5g) resulted in 40% gut bioaccessibility for BDE153 and BDE183, whereas greater bioaccessibility values were seen for less hydrophobic PBDEs such as BDE28 and BDE47 (~60%). When tested using SRM 2585 (n=3), our new Tenax TA® method did not present any statistically significant effect (p>0.05) between non-spiked and PBDE-spiked SRM 2585 treatments. Our study describes an efficient method where due to the sophisticated design, Tenax TA® recovery and subsequent bioaccessibility determination can be simply and reliably achieved.
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Side chain variations radically alter the diffusion of poly(2-alkyl-2-oxazoline) functionalised nanoparticles through a mucosal barrier. Biomater Sci 2018; 4:1318-27. [PMID: 27400181 DOI: 10.1039/c6bm00375c] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Functionalised nanomaterials are gaining popularity for use as drug delivery vehicles and, in particular, mucus penetrating nanoparticles may improve drug bioavailability via the oral route. To date, few polymers have been investigated for their muco-penetration, and the effects of systematic structural changes to polymer architectures on the penetration and diffusion of functionalised nanomaterials through mucosal tissue have not been reported. We investigated the influence of poly(2-oxazoline) alkyl side chain length on nanoparticle diffusion; poly(2-methyl-2-oxazoline), poly(2-ethyl-2-oxazoline), and poly(2-n-propyl-2-oxazoline) were grafted onto the surface of thiolated silica nanoparticles and characterised by FT-IR, Raman and NMR spectroscopy, thermogravimetric analysis, and small angle neutron scattering. Diffusion coefficients were determined in water and in a mucin dispersion (using Nanoparticle Tracking Analysis), and penetration through a mucosal barrier was assessed using an ex vivo fluorescence technique. The addition of a single methylene group in the side chain significantly altered the penetration and diffusion of the materials in both mucin dispersions and mucosal tissue. Nanoparticles functionalised with poly(2-methyl-2-oxazoline) were significantly more diffusive than particles with poly(2-ethyl-2-oxazoline) while particles with poly(2-n-propyl-2-oxazoline) showed no significant increase compared to the unfunctionalised particles. These data show that variations in the polymer structure can radically alter their diffusive properties with clear implications for the future design of mucus penetrating systems.
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RNA Aptamer Delivery through Intact Human Skin. J Invest Dermatol 2018; 138:282-290. [PMID: 28942363 DOI: 10.1016/j.jid.2017.07.851] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 07/04/2017] [Accepted: 07/25/2017] [Indexed: 01/09/2023]
Abstract
It is generally recognized that only relatively small molecular weight (typically < ∼ 500 Da) drugs can effectively permeate through intact stratum corneum. Here, we challenge this orthodoxy using a 62-nucleotide (molecular weight = 20,395 Da) RNA-based aptamer, highly specific to the human IL-23 cytokine, with picomolar activity. Results demonstrate penetration of the aptamer into freshly excised human skin using two different fluorescent labels. A dual hybridization assay quantified aptamer from the epidermis and dermis, giving levels far exceeding the cellular half maximal inhibitory concentration values (>100,000-fold), and aptamer integrity was confirmed using an oligonucleotide precipitation assay. A T helper 17 response was stimulated in freshly excised human skin resulting in significantly upregulated IL-17f, and IL-22; topical application of the IL-23 aptamer decreased both IL-17f and IL-22 by approximately 45% but did not result in significant changes to IL-23 mRNA levels, confirming that the aptamer did not globally suppress mRNA levels. This study demonstrates that very-large-molecular-weight RNA aptamers can permeate across the intact human skin barrier to therapeutically relevant levels into both the epidermis and dermis and that the skin-penetrating aptamer retains its biologically active conformational structure capable of binding to endogenous IL-23.
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Structure and characterisation of hydroxyethylcellulose–silica nanoparticles. RSC Adv 2018; 8:6471-6478. [PMID: 35540425 PMCID: PMC9078266 DOI: 10.1039/c7ra08716k] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Accepted: 01/29/2018] [Indexed: 12/01/2022] Open
Abstract
Functionalising nanoparticles with polymers has gained much interest in recent years, as it aids colloidal stability and manipulation of surface properties. Here, polymer-coated thiolated silica nanoparticles were synthesised by self-condensation of 3-mercaptopropyltrimethoxysilane in the presence of hydroxyethylcellulose. These nanoparticles were characterised by dynamic light scattering, small angle neutron scattering, Nanoparticle Tracking Analysis, Raman spectroscopy, FT-IR spectroscopy, thermogravimetric analysis, Ellman's assay, transmission electron microscopy and cryo-transmission electron microscopy. It was found that increasing the amount of hydroxyethylcellulose in the reaction mixture increased the nanoparticle size and reduced the number of thiol groups on their surface. Additionally, by utilising small angle neutron scattering and dynamic light scattering, it was demonstrated that higher concentrations of polymer in the reaction mixture (0.5–2% w/v) resulted in the formation of aggregates, whereby several silica nanoparticles are bridged together with macromolecules of hydroxyethylcellulose. A correlation was identified between the aggregate size and number of particles per aggregate based on size discrepancies observed between DLS and SANS measurements. This information makes it possible to control the size of aggregates during a simple one-pot synthesis; a prospect highly desirable in the design of potential drug delivery systems. Polymer-coated thiolated silica nanoparticles were synthesised by self-condensation of 3-mercaptopropyltrimethoxysilane in the presence of hydroxyethylcellulose.![]()
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LGR5 expression is regulated by EGF in early colorectal adenomas and governs EGFR inhibitor sensitivity. Br J Cancer 2017; 118:558-565. [PMID: 29149105 PMCID: PMC5830587 DOI: 10.1038/bjc.2017.412] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Revised: 10/18/2017] [Accepted: 10/19/2017] [Indexed: 12/25/2022] Open
Abstract
Background: LGR5 serves as a co-receptor for Wnt/β-catenin signalling and marks normal intestinal stem cells; however, its role in colorectal cancer (CRC) remains controversial. LGR5+ cells are known to exist outside the stem cell niche during CRC progression, and the requirement for epidermal growth factor (EGF) signalling within early adenomas remains to be fully elucidated. Methods: Epidermal growth factor and gefitinib treatments were performed in EGF-responsive LGR5+ early adenoma RG/C2 cells. 2D growth assays were measured using an IncuCyte. LGR5 or MEK1/2 silencing studies were executed using siRNA and LGR5 expression was assessed by qRT–PCR and immunoblotting. Ki67 level and cell cycle status were analysed by flow cytometry. Results: Epidermal growth factor suppresses expression of LGR5 at both the transcript and protein level in colorectal adenoma and carcinoma cells. Suppression of LGR5 reduces the survival of EGF-treated adenoma cells by increasing detached cell yield but also inducing a proliferative state, as evidenced by elevated Ki67 level and enhanced cell cycle progression. Repression of LGR5 further increases the sensitivity of adenoma cells to EGFR inhibition. Conclusions: LGR5 has an important role in the EGF-mediated survival and proliferation of early adenoma cells and could have clinical utility in predicting response of CRC patients to EGFR therapy.
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Improved performance of crystal structure solution from powder diffraction data through parameter tuning of a simulated annealing algorithm. J Appl Crystallogr 2017. [DOI: 10.1107/s1600576717012602] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Significant gains in the performance of the simulated annealing algorithm in theDASHsoftware package have been realized by using theiraceautomatic configuration tool to optimize the values of three key simulated annealing parameters. Specifically, the success rate in finding the global minimum in intensity χ2space is improved by up to an order of magnitude. The general applicability of these revised simulated annealing parameters is demonstrated using the crystal structure determinations of over 100 powder diffraction datasets.
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Improved crystal structure solution from powder diffraction data by the use of conformational information. J Appl Crystallogr 2017. [DOI: 10.1107/s1600576717012596] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
The effect of introducing conformational information to theDASHimplementation of crystal structure determination from powder diffraction data is investigated using 51 crystal structures, with the aim of allowing increasingly complex crystal structures to be solved more easily. The findings confirm that conformational information derived from the Cambridge Structural Database is indeed of value, considerably increasing the chances of obtaining a successful structure determination. Its routine use is therefore encouraged.
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Nicotinamide alone accelerates the conversion of mouse embryonic stem cells into mature neuronal populations. PLoS One 2017; 12:e0183358. [PMID: 28817722 PMCID: PMC5560552 DOI: 10.1371/journal.pone.0183358] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Accepted: 08/02/2017] [Indexed: 01/26/2023] Open
Abstract
Introduction Vitamin B3 has been shown to play an important role during embryogenesis. Specifically, there is growing evidence that nicotinamide, the biologically active form of vitamin B3, plays a critical role as a morphogen in the differentiation of stem cells to mature cell phenotypes, including those of the central nervous system (CNS). Detailed knowledge of the action of small molecules during neuronal differentiation is not only critical for uncovering mechanisms underlying lineage-specification, but also to establish more effective differentiation protocols to obtain clinically relevant cells for regenerative therapies for neurodegenerative conditions such as Huntington’s disease (HD). Thus, this study aimed to investigate the potential of nicotinamide to promote the conversion of stem cells to mature CNS neurons. Methods Nicotinamide was applied to differentiating mouse embryonic stem cells (mESC; Sox1GFP knock-in 46C cell line) during their conversion towards a neural fate. Cells were assessed for changes in their proliferation, differentiation and maturation; using immunocytochemistry and morphometric analysis methods. Results Results presented indicate that 10 mM nicotinamide, when added at the initial stages of differentiation, promoted accelerated progression of ESCs to a neural lineage in adherent monolayer cultures. By 14 days in vitro (DIV), early exposure to nicotinamide was shown to increase the numbers of differentiated βIII-tubulin-positive neurons. Nicotinamide decreased the proportion of pluripotent stem cells, concomitantly increasing numbers of neural progenitors at 4 DIV. These progenitors then underwent rapid conversion to neurons, observed by a reduction in Sox 1 expression and decreased numbers of neural progenitors in the cultures at 14 DIV. Furthermore, GABAergic neurons generated in the presence of nicotinamide showed increased maturity and complexity of neurites at 14 DIV. Therefore, addition of nicotinamide alone caused an accelerated passage of pluripotent cells through lineage specification and further to non-dividing mature neurons. Conclusions Our results show that, within an optimal dose range, nicotinamide is able to singly and selectively direct the conversion of embryonic stem cells to mature neurons, and therefore may be a critical factor for normal brain development, thus supporting previous evidence of the fundamental role of vitamins and their metabolites during early CNS development. In addition, nicotinamide may offer a simple effective supplement to enhance the conversion of stem cells to clinically relevant neurons.
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Potentiating the effects of radiotherapy in rectal cancer: the role of aspirin, statins and metformin as adjuncts to therapy. Br J Cancer 2017; 117:210-219. [PMID: 28641310 PMCID: PMC5520519 DOI: 10.1038/bjc.2017.175] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2017] [Revised: 05/03/2017] [Accepted: 05/22/2017] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Complete tumour response (pCR) to neo-adjuvant chemo-radiotherapy for rectal cancer is associated with a reduction in local recurrence and improved disease-free and overall survival, but is achieved in only 20-30% of patients. Drug repurposing for anti-cancer treatments is gaining momentum, but the potential of such drugs as adjuncts, to increase tumour response to chemo-radiotherapy in rectal cancer, is only just beginning to be recognised. METHODS A systematic literature search was conducted and all studies investigating the use of drugs to enhance response to neo-adjuvant radiation in rectal cancer were included. 2137 studies were identified and following review 12 studies were extracted for full text review, 9 studies were included in the final analysis. RESULTS The use of statins or aspirin during neo-adjuvant therapy was associated with a significantly higher rate of tumour downstaging. Statins were identified as a significant predictor of pCR and aspirin users had a greater 5-year progression-free survival and overall survival. Metformin use was associated with a significantly higher overall and disease-free survival, in a subset of diabetic patients. CONCLUSIONS Aspirin, metformin and statins are associated with increased downstaging of rectal tumours and thus may have a role as adjuncts to neoadjuvant treatment, highlighting a clear need for prospective randomised controlled trials to determine their true impact on tumour response and overall survival.
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Meat Intake and the Dose of Vitamin B 3 - Nicotinamide: Cause of the Causes of Disease Transitions, Health Divides, and Health Futures? Int J Tryptophan Res 2017; 10:1178646917704662. [PMID: 28579801 PMCID: PMC5419340 DOI: 10.1177/1178646917704662] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Accepted: 03/15/2017] [Indexed: 12/26/2022] Open
Abstract
Meat and vitamin B3 - nicotinamide - intake was high during hunter-gatherer times. Intake then fell and variances increased during and after the Neolithic agricultural revolution. Health, height, and IQ deteriorated. Low dietary doses are buffered by 'welcoming' gut symbionts and tuberculosis that can supply nicotinamide, but this co-evolved homeostatic metagenomic strategy risks dysbioses and impaired resistance to pathogens. Vitamin B3 deficiency may now be common among the poor billions on a low-meat diet. Disease transitions to non-communicable inflammatory disorders (but longer lives) may be driven by positive 'meat transitions'. High doses of nicotinamide lead to reduced regulatory T cells and immune intolerance. Loss of no longer needed symbiotic 'old friends' compounds immunological over-reactivity to cause allergic and auto-immune diseases. Inhibition of nicotinamide adenine dinucleotide consumers and loss of methyl groups or production of toxins may cause cancers, metabolic toxicity, or neurodegeneration. An optimal dosage of vitamin B3 could lead to better health, but such a preventive approach needs more equitable meat distribution. Some people may require personalised doses depending on genetic make-up or, temporarily, when under stress.
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Meat and Nicotinamide: A Causal Role in Human Evolution, History, and Demographics. Int J Tryptophan Res 2017; 10:1178646917704661. [PMID: 28579800 PMCID: PMC5417583 DOI: 10.1177/1178646917704661] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Accepted: 03/15/2017] [Indexed: 01/15/2023] Open
Abstract
Hunting for meat was a critical step in all animal and human evolution. A key brain-trophic element in meat is vitamin B3 / nicotinamide. The supply of meat and nicotinamide steadily increased from the Cambrian origin of animal predators ratcheting ever larger brains. This culminated in the 3-million-year evolution of Homo sapiens and our overall demographic success. We view human evolution, recent history, and agricultural and demographic transitions in the light of meat and nicotinamide intake. A biochemical and immunological switch is highlighted that affects fertility in the 'de novo' tryptophan-to-kynurenine-nicotinamide 'immune tolerance' pathway. Longevity relates to nicotinamide adenine dinucleotide consumer pathways. High meat intake correlates with moderate fertility, high intelligence, good health, and longevity with consequent population stability, whereas low meat/high cereal intake (short of starvation) correlates with high fertility, disease, and population booms and busts. Too high a meat intake and fertility falls below replacement levels. Reducing variances in meat consumption might help stabilise population growth and improve human capital.
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Adhesion of thiolated silica nanoparticles to urinary bladder mucosa: Effects of PEGylation, thiol content and particle size. Int J Pharm 2016; 512:32-38. [PMID: 27530813 DOI: 10.1016/j.ijpharm.2016.08.026] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Revised: 08/10/2016] [Accepted: 08/13/2016] [Indexed: 12/15/2022]
Abstract
Intravesical drug administration is used to deliver cytotoxic agents through a catheter to treat bladder cancer. One major limitation of this approach is poor retention of the drug in the bladder due to periodic urine voiding. Mucoadhesive dosage forms thus offer significant potential to improve drug retention in the bladder. Here, we investigate thiolated silica nanoparticles retention on porcine bladder mucosa in vitro, quantified through Wash Out50 (WO50) values, defined as the volume of liquid necessary to remove 50% of the adhered particles from a mucosal tissue. Following irrigation with artificial urine solution, the thiolated nanoparticles demonstrate significantly greater retention (WO50 up to 36mL) compared to non-mucoadhesive dextran (WO50 7mL), but have weaker mucoadhesive properties than chitosan (WO50 89mL). PEGylation of thiolated silica reduces their mucoadhesion with WO50 values of 29 and 8mL for particles decorated with 750 and 5000Da PEG, respectively. The retention of thiolated silica nanoparticles is dependent on their thiol group contents and physical dimensions.
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Design, synthesis and characterization of linear unnatural amino acids for skin moisturization. Int J Cosmet Sci 2016; 39:72-82. [PMID: 27380298 PMCID: PMC5244679 DOI: 10.1111/ics.12351] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2015] [Accepted: 06/29/2016] [Indexed: 12/16/2022]
Abstract
OBJECTIVES This work aimed to design, synthesize and characterize replacement natural moisturizing factor (NMF) composed of modified hygroscopic linear amino acids to pre-empt or repair skin barrier dysfunction. METHODS Following synthesis and characterization, thermo-gravimetric analysis and quantum mechanics molecular modelling quantified and depicted water binding to the new compounds. Deliquescence relative humidity demonstrated the water-scavenging ability of the compounds, whereas snake skin moisturizing studies showed they increased water uptake into snake skin. RESULTS From thermal analysis, N-hydroxyglycine showed greatest water-holding capacity followed by N-hydroxyserine, l-homoserine and α-hydroxyglycine; coupled with quantum mechanics molecular modelling, between 8 and 12 molecules of water could associate with each molecule of either N-hydroxyglycine, N-hydroxyserine or l-homoserine. All of our modified amino acids were efficacious and induced similar or greater water uptake compared with the established moisturizing compounds hyaluronic acid, glycerine and urea in snake skin. Incorporated at 10% in Oilatum, N-hydroxyserine induced >200% greater moisture uptake into dry snake skin compared to treatment with water alone, with efficacy related to the molecule structure and ability to bind to 12 water molecules. Oilatum cream spiked with all our unnatural amino acid hydrotropes increased water uptake into snake skin compared with Oilatum alone. The compound series was designed to elucidate some structure - efficacy relationships. Amino acid chirality did not affect the water-holding capacity but did affect uptake into skin. Compounds with high melting points and bond energies tended to decrease water-holding capacity. With isosteric replacement, the more electronegative atoms gave greater water-holding capacities. CONCLUSIONS This work demonstrates the potential of unnatural amino acid hydrotropes as skin moisturizers and has developed some predictive 'rules' for further design and refinement of chemical structures.
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Deep Brain Stimulation for Parkinson's Disease with Early Motor Complications: A UK Cost-Effectiveness Analysis. PLoS One 2016; 11:e0159340. [PMID: 27441637 PMCID: PMC4956248 DOI: 10.1371/journal.pone.0159340] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Accepted: 06/30/2016] [Indexed: 11/26/2022] Open
Abstract
BACKGROUND Parkinson's disease (PD) is a debilitating illness associated with considerable impairment of quality of life and substantial costs to health care systems. Deep brain stimulation (DBS) is an established surgical treatment option for some patients with advanced PD. The EARLYSTIM trial has recently demonstrated its clinical benefit also in patients with early motor complications. We sought to evaluate the cost-effectiveness of DBS, compared to best medical therapy (BMT), among PD patients with early onset of motor complications, from a United Kingdom (UK) payer perspective. METHODS We developed a Markov model to represent the progression of PD as rated using the Unified Parkinson's Disease Rating Scale (UPDRS) over time in patients with early PD. Evidence sources were a systematic review of clinical evidence; data from the EARLYSTIM study; and a UK Clinical Practice Research Datalink (CPRD) dataset including DBS patients. A mapping algorithm was developed to generate utility values based on UPDRS data for each intervention. The cost-effectiveness was expressed as the incremental cost per quality-adjusted life-year (QALY). One-way and probabilistic sensitivity analyses were undertaken to explore the effect of parameter uncertainty. RESULTS Over a 15-year time horizon, DBS was predicted to lead to additional mean cost per patient of £26,799 compared with BMT (£73,077/patient versus £46,278/patient) and an additional mean 1.35 QALYs (6.69 QALYs versus 5.35 QALYs), resulting in an incremental cost-effectiveness ratio of £19,887 per QALY gained with a 99% probability of DBS being cost-effective at a threshold of £30,000/QALY. One-way sensitivity analyses suggested that the results were not significantly impacted by plausible changes in the input parameter values. CONCLUSION These results indicate that DBS is a cost-effective intervention in PD patients with early motor complications when compared with existing interventions, offering additional health benefits at acceptable incremental cost. This supports the extended use of DBS among patients with early onset of motor complications.
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Towards pain-free diagnosis of skin diseases through multiplexed microneedles: biomarker extraction and detection using a highly sensitive blotting method. Drug Deliv Transl Res 2016; 5:387-96. [PMID: 25939431 DOI: 10.1007/s13346-015-0231-5] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Immunodiagnostic microneedles provide a novel way to extract protein biomarkers from the skin in a minimally invasive manner for analysis in vitro. The technology could overcome challenges in biomarker analysis specifically in solid tissue, which currently often involves invasive biopsies. This study describes the development of a multiplex immunodiagnostic device incorporating mechanisms to detect multiple antigens simultaneously, as well as internal assay controls for result validation. A novel detection method is also proposed. It enables signal detection specifically at microneedle tips and therefore may aid the construction of depth profiles of skin biomarkers. The detection method can be coupled with computerised densitometry for signal quantitation. The antigen specificity, sensitivity and functional stability of the device were assessed against a number of model biomarkers. Detection and analysis of endogenous antigens (interleukins 1α and 6) from the skin using the device was demonstrated. The results were verified using conventional enzyme-linked immunosorbent assays. The detection limit of the microneedle device, at ≤10 pg/mL, was at least comparable to conventional plate-based solid-phase enzyme immunoassays.
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Abstract
The simulated annealing approach to crystal structure determination from powder diffraction data, as implemented in theDASHprogram, is readily amenable to parallelization at the individual run level. Very large scale increases in speed of execution can be achieved by distributing individualDASHruns over a network of computers. TheCDASHprogram delivers this by using scalable on-demand computing clusters built on the Amazon Elastic Compute Cloud service. By way of example, a 360 vCPU cluster returned the crystal structure of racemic ornidazole (Z′ = 3, 30 degrees of freedom)ca40 times faster than a typical modern quad-core desktop CPU. Whilst used here specifically forDASH, this approach is of general applicability to other packages that are amenable to coarse-grained parallelism strategies.
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Re: Cost-effectiveness of continuous subcutaneous apomorphine in the treatment of Parkinson's Disease in the UK and Germany. J Med Econ 2015; 18:858-9. [PMID: 26121159 DOI: 10.3111/13696998.2015.1066797] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Increasing doxorubicin activity against breast cancer cells using PPARγ-ligands and by exploiting circadian rhythms. Br J Pharmacol 2015; 169:1178-88. [PMID: 23578093 DOI: 10.1111/bph.12202] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2012] [Revised: 01/25/2013] [Accepted: 04/09/2013] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND AND PURPOSE Doxorubicin is effective against breast cancer, but its major side effect is cardiotoxicity. The aim of this study was to determine whether the efficacy of doxorubicin on cancer cells could be increased in combination with PPARγ agonists or chrono-optimization by exploiting the diurnal cycle. EXPERIMENTAL APPROACH We determined cell toxicity using MCF-7 cancer cells, neonatal rat cardiac myocytes and fibroblasts in this study. KEY RESULTS Doxorubicin damages the contractile filaments of cardiac myocytes and affects cardiac fibroblasts by significantly inhibiting collagen production and proliferation at the level of the cell cycle. Cyclin D1 protein levels decreased significantly following doxorubicin treatment indicative of a G1/S arrest. PPARγ agonists with doxorubicin increased the toxicity to MCF-7 cancer cells without affecting cardiac cells. Rosiglitazone and ciglitazone both enhanced anti-cancer activity when combined with doxorubicin (e.g. 50% cell death for doxorubicin at 0.1 μM compared to 80% cell death when combined with rosiglitazone). Thus, the therapeutic dose of doxorubicin could be reduced by 20-fold through combination with the PPARγ agonists, thereby reducing adverse effects on the heart. The presence of melatonin also significantly increased doxorubicin toxicity, in cardiac fibroblasts (1 μM melatonin) but not in MCF-7 cells. CONCLUSIONS AND IMPLICATIONS Our data show, for the first time, that circadian rhythms play an important role in doxorubicin toxicity in the myocardium; doxorubicin should be administered mid-morning, when circulating levels of melatonin are low, and in combination with rosiglitazone to increase therapeutic efficacy in cancer cells while reducing the toxic effects on the heart.
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Nutrient stress alters the glycosylation status of LGR5 resulting in reduced protein stability and membrane localisation in colorectal tumour cells: implications for targeting cancer stem cells. Br J Cancer 2015; 112:714-9. [PMID: 25611300 PMCID: PMC4333507 DOI: 10.1038/bjc.2015.4] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2014] [Revised: 12/15/2014] [Accepted: 12/22/2014] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND LGR5 is an important marker of intestinal stem cells and performs its vital functions at the cell membrane. Despite the importance of LGR5 to both normal and cancer stem cell biology, it is not known how microenvironmental stress affects the expression and subcellular distribution of the protein. METHODS Nutrient stress was induced through glucose starvation. Glycosylation status was assessed using endoglycosidase or tunicamycin treatment. Flow cytometry and confocal microscopy were used to assess subcellular distribution of LGR5. RESULTS Glucose deprivation altered the glycosylation status of LGR5 resulting in reduced protein stability and cell surface expression. Furthermore, inhibiting LGR5 glycosylation resulted in depleted surface expression and reduced localisation in the cis-Golgi network. CONCLUSIONS Nutrient stress within a tumour microenvironment has the capacity to alter LGR5 protein stability and membrane localisation through modulation of LGR5 glycosylation status. As LGR5 surface localisation is required for enhanced Wnt signalling, this is the first report to show a mechanism by which the microenvironment could affect LGR5 function.
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The development of a patient-centered measure of the process and outcome of combined orthodontic and orthognathic treatment. J Orthod 2014; 31:220-34; discussion 201-2. [PMID: 15489366 DOI: 10.1179/146531204225022434] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
OBJECTIVE The aim of this study was to develop a patient-based measure of the process and outcome of combined orthodontic and orthognathic care in the National Health Service in the UK. DESIGN Identification of relevant dimensions through qualitative methods, design of form, determination of psychometric properties of the scale, specific readability, reliability and validity. SETTING NHS hospitals in the South West Region. SUBJECTS The sample comprised patients who had received combined orthodontic and orthognathic treatment between 01 January 1998 and 31 December 2000. Twenty-six participants (a 25% response rate) took part in four focus group meetings. Thirty subjects (65% response rate) took part in a pilot study to test the properties of the questionnaire. MAIN OUTCOME MEASURES Six broad themes emerged from the focus groups. These formed the basis of the sections in the questionnaire. RESULTS The questionnaire developed had a Flesch reading ease score of 72.9 or US grade level 4 equivalent to aged 9-10 years. Test-retest reliability gave kappa values for most questions that exceeded 0.4. Criterion validity of the measure was established by comparing responses to the questionnaire over two periods with a telephone interview on a sample of 30 patients. Criterion related validity was poor for nine of the 16 items. By contrast the construct validity of the questionnaire was satisfactory. CONCLUSION A patient-based measure of the process and outcome of combined orthodontic and orthognathic treatment has been developed. This has sufficient validity and reliability for use in inter-center audit projects.
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Patients’ motivations for treatment and their experiences of orthodontic preparation for orthognathic surgery. J Orthod 2014; 32:191-202. [PMID: 16170061 DOI: 10.1179/146531205225021096] [Citation(s) in RCA: 75] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
OBJECTIVE To determine patients' motivations for undergoing orthognathic surgery and their experiences of the orthodontic aspects of this treatment. DESIGN Retrospective questionnaire survey using a patient-centred measure. SETTING Thirteen National Health Service (NHS) hospital orthodontic departments. SUBJECTS Three-hundred-and-twenty-six patients (58% response rate) who underwent orthognathic surgery during the period 1 January 1995 to 30 September 2001 completed a questionnaire. MAIN OUTCOME MEASURES Motivations for treatment and perception of information about treatment and experiences of orthodontic treatment. RESULTS Major motivations for treatment were to have straight teeth (80%), to prevent future dental problems (69%) and to improve self-confidence (68%). Females sought treatment to improve self-confidence and their smile. Males wanted treatment to improve their social life. Most of these issues had improved following surgery. Most (94%) respondents felt well-informed about their orthodontics. However, 36% wore braces for longer than they expected. Males and younger patients knew less about the duration of treatment than other groups. Fifty-eight per cent of subjects found their braces difficult to clean and 9% reported that they were very painful. Older patients experienced fewer problems wearing braces than younger patients. CONCLUSIONS Improving dental appearance and preventing future dental problems are major motivators for orthognathic patients. Although patients felt well informed about what to expect from their orthodontic treatment, a significant proportion, particularly younger patients and males, were surprised at the length of treatment and the need to wear retainers. This suggests that orthognathic patients might benefit from better information regarding the orthodontic aspects of their care.
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