• Q10-triggered facial vitiligo.

      Schallreuter, Karin U. (2013-12)
      Background Generation and accumulation of reactive oxygen/nitrogen species in the epidermis of patients with vitiligo has been widely documented. Moreover, semiquinone radical-mediated sensitivity has been shown in blood lymphocytes of these patients. Objectives To determine the possible mechanism behind Q10-induced facial vitiligo. Methods This was a clinical assessment supported by in vivo Fourier transform–Raman spectroscopy and repigmentation. Results Topical Q10 application generated hydrogen peroxide (H2O2) leading in turn to facial vitiligo in susceptible individuals. Proof of the basic result stemmed from reduction of epidermal H2O2 by using narrowband ultraviolet B-activated propseudocatalase PC-KUS in association with cessation of depigmentation and repigmentation of the lost skin colour. Conclusions Over-the-counter availability of Q10-containing topical formulations can be harmful to individuals susceptible to vitiligo.
    • Qualitative and Quantitative Assessment of Fatty Acids of Buddleja asiatica by GC-MS

      Ali, F.; Ali, I.; Bibi, H.; Malik, A.; Stern, Ben; Maitland, Derek J. (2013-06)
      To analyze the fatty acid contents of Buddleja asiatica Lour, both the non-volatile oil and fat obtained from the n-hexane soluble sub-fraction were subjected to GC/MS using BSTFA (N,O-bis(trimethylsilyl) trifloroacetamide) derivatization. The oil showed the presence of six fatty acids including palmitic acid (46.75 %), linoleic acid (37.80 %), stearic acid (10.98 %), arachidic acid, margaric acid and lignoceric acid (< 3 %). Analysis of the fat revealed nine fatty acids including lignoceric acid (43.12 %), behenic acid (26.39 %), arachidic acid (9.29 %) and stearic acid (5.3 %). Cerotic acid, montanic acid, melissic acid and palmitic acid were found in low amounts (< 5 %) while trycosylic acid (4.83 %) was the only fatty acid with odd number of carbon atoms. The oil showed a low thermal stability.
    • A qualitative study of patient involvement in medicines management after hospital discharge: an under-recognised source of systems resilience

      Fylan, Beth; Armitage, Gerry R.; Naylor, Deirdre; Blenkinsopp, Alison (2018-07)
      Introduction: There are risks to the safety of medicines management when patient care is transferred between healthcare organisations, for example when a patient is discharged from hospital. Using the theoretical concept of resilience in healthcare, this study aimed to better understand the proactive role that patients can play in creating a safer, resilient medicines management at a common transition of care. Methods: Qualitative interviews with 60 cardiology patients six weeks after their discharge from two UK hospitals explored patients’ experiences with their discharge medicines. Data were initially subjected to an inductive thematic analysis and a subsequent theory-guided deductive analysis. Results: During interviews twenty-three patients described medicines management resilience strategies in two main themes: identifying system vulnerabilities; and establishing self-management strategies. Patients could anticipate problems in the system that supplied them with medicines and took specific actions to prevent them. They also identified when errors had occurred both before and after medicines had been supplied and took corrective action to avoid harm. Some reported how they had not foreseen problems or experienced patient safety incidents. Patients recounted how they ensured information about medicines changes was correctly communicated and acted upon, and identified their strategies to enhance their own reliability in adherence and resource management. Conclusion: Patients experience the impact of vulnerabilities in the medicines management system across the secondary-primary care transition but many are able to enhance system resilience through developing strategies to reduce the risk of medicines errors occurring. Consequently, there are opportunities – with caveats – to elicit, develop and formalise patients’ capabilities which would contribute to safer patient care and more effective medicines management.
    • Quantitative analysis of cytochrome P450 isoforms in human liver microsomes by the combination of proteomics and chemical probe-based assay

      Liu, X.; Hu, L.; Ge, G.; Yang, B.; Ning, J.; Sun, S.; Yang, L.; Pors, Klaus; Gu, J. (2014)
      Cytochrome P450 (CYP) is one of the most important drug-metabolizing enzyme families, which participates in the biotransformation of many endogenous and exogenous compounds. Quantitative analysis of CYP expression levels is important when studying the efficacy of new drug molecules and assessing drug-drug interactions in drug development. At present, chemical probe-based assay is the most widely used approach for the evaluation of CYP activity although there are cross-reactions between the isoforms with high sequence homologies. Therefore, quantification of each isozyme is highly desired in regard to meeting the ever-increasing requirements for carrying out pharmacokinetics and personalized medicine in the academic, pharmaceutical, and clinical setting. Herein, an absolute quantification method was employed for the analysis of the seven isoforms CYP1A2, 2B6, 3A4, 3A5, 2C9, 2C19, and 2E1 using a proteome-derived approach in combination with stable isotope dilution assay. The average absolute amount measured from twelve human liver microsomes samples were 39.3, 4.3, 54.0, 4.6, 10.3, 3.0, and 9.3 (pmol/mg protein) for 1A2, 2B6, 3A4, 3A5, 2C9, 2C19, and 2E1, respectively. Importantly, the expression level of CYP3A4 showed high correlation (r = 0.943, p < 0.0001) with the functional activity, which was measured using bufalin-a highly selective chemical probe we have developed. The combination of MRM identification and analysis of the functional activity, as in the case of CYP3A4, provides a protocol which can be extended to other functional enzyme studies with wide application in pharmaceutical research.
    • Quantitative Analysis Of Mannitol Polymorphs - X-Ray Powder Diffractometry. Exploring Preferred Orientation Effects.

      Grimsey, Ian M.; Booth, S.W.; Campbell Roberts, Sarra N.; Williams, Adrian C. (2009-08-12)
      Mannitol is a polymorphic pharmaceutical excipient, which commonly exists in three forms: alpha, beta and delta. Each polymorph has a needle-like morphology, which can give preferred orientation effects when analysed by X-ray powder diffractometry (XRPD) thus providing difficulties for quantitative XRPD assessments. The occurrence of preferred orientation may be demonstrated by sample rotation and the consequent effects on X-ray data can be minimised by reducing the particle size. Using two particle size ranges (<125 and 125¿500 ¿m), binary mixtures of beta and delta mannitol were prepared and the delta component was quantified. Samples were assayed in either a static or rotating sampling accessory. Rotation and reducing the particle size range to <125 ¿m halved the limits of detection and quantitation to 1 and 3.6%, respectively. Numerous potential sources of assay errors were investigated; sample packing and mixing errors contributed the greatest source of variation. However, the rotation of samples for both particle size ranges reduced the majority of assay errors examined. This study shows that coupling sample rotation with a particle size reduction minimises preferred orientation effects on assay accuracy, allowing discrimination of two very similar polymorphs at around the 1% level.
    • Quantitative analysis of spermatogenesis and apoptosis in the common marmoset (Callithrix jacchus) reveals high spermatogonial turnover and spermatogenic efficiency.

      Brinkworth, Martin H.; Aslam, H.; Krishnamurthy, H.; Weinbauer, G.F.; Einspanier, A. (2009-07-06)
      Spermatogenesis is characterized by the succession in time and space of specific germ cell associations (stages). There can be a single stage (e.g., rodents and some macaques) or more than one stage (e.g., chimpanzee and human) per tubular cross section. We analyzed the organization of the seminiferous epithelium and quantified testicular germ cell production and apoptosis in a New World primate, the common marmoset (Callithrix jacchus). Tubule cross sections contained more than one stage, and the human six-stage system could be applied to marmoset spermatogenesis. Stereological (optical disector) analysis (n = 5) revealed high spermatogenic efficiency during meiosis and no loss of spermatids during spermiogenesis. The conversion of type A to type B spermatogonia was several-fold higher than that reported for other primates. Highest apoptotic rates were found for S-phase cells (20%) and 4C cells (15%) by flow cytometric analysis (n = 6 animals); histological analysis confirmed spermatogonial apoptosis. Haploid germ cell apoptosis was <2%. Marmoset spermatogenesis is very efficient and involves substantial spermatogonial proliferation. The prime determinants of germ cell production in primates appear to be proliferation and survival of spermatogonia rather than the efficiency of meiotic divisions. Based on the organizational similarities, common marmosets could provide a new animal model for experimental studies of human spermatogenesis.
    • Quantitative analysis of surfactant deposits on human skin by liquid chromatography electrospray ionisation tandem mass spectrometry.

      Massey, Karen A.; Snelling, Anna M.; Nicolaou, Anna (Wiley, 2010)
      Surfactants are commonly used as cleansing agents and yet there are concerns they may also have a role in skin irritation. Presently, the lack of suitable methods for quantitative and qualitative analysis of surfactant deposition on skin has hindered the in-depth investigation of such effects. Here, we report the application of reverse phase liquid chromatography electrospray ionisation mass spectrometry (LC/ESI-MS/MS) assays for two surfactants commonly used in consumer products, namely sodium lauryl ether sulphate (SLES) and laurylamidopropyl betaine (LAPB), to a baseline study aiming to assess deposition levels on human skin. The linearity of the assays was established at 3-20 ng, with coefficient of variation below 5%. Detection limits were 100 pg for LAPB and 1 ng for SLES; quantitation limits were 500 pg for LAPB and 2.5 ng for SLES. The baseline study was conducted using a panel of 40 healthy volunteers. Skin extract samples were taken in triplicate from forearms, using ethanol. SLES was detected on most volunteers, with 75% of them having SLES deposits in the range of 100-600 ng/cm2. LAPB was detected on the skin of all volunteers with 85% of them having deposit levels within the concentration range of 1-100 ng/cm2. These results demonstrate the extent to which commonly used surfactants remain on the skin during the day. The analytical methods reported here can be applied to the investigation of surfactants in relation to general skin condition and the development and optimisation of new consumer wash products.
    • Quantitative analysis of surfactant deposits on human skin by liquid chromatography/electrospray ionisation tandem mass spectrometry.

      Massey, Karen A.; Snelling, Anna M.; Nicolaou, Anna (2010)
      Surfactants are commonly used as cleansing agents and yet there are concerns that they may also have a role in skin irritation. The lack of suitable methods for the quantitative and qualitative analysis of surfactant deposition on skin has hindered the in-depth investigation of such effects. Here, we report the application of reversed-phase liquid chromatography/electrospray ionisation tandem mass spectrometry (LC/ESI-MS/MS) assays for two surfactants commonly used in consumer products, namely sodium lauryl ether sulfate (SLES) and laurylamidopropyl betaine (LAPB), to a baseline study aiming to assess deposition levels on human skin. The linearity of the assays was established at 3-20 ng, with coefficient of variation below 5%. The detection limits were 100 pg for LAPB and 1 ng for SLES; quantitation limits were 500 pg for LAPB and 2.5 ng for SLES. The baseline study was conducted using a panel of 40 healthy volunteers. Skin extract samples were taken in triplicate from forearms, using ethanol. SLES was detected on most volunteers, with 75% of them having SLES deposits in the range of 100-600 ng/cm(2). LAPB was detected on the skin of all volunteers with 85% of them having deposit levels within the concentration range of 1-100 ng/cm(2). These results demonstrate the extent to which commonly used surfactants remain on the skin during the day. The analytical methods reported here can be applied to the investigation of surfactants in relation to general skin condition and to the development and optimisation of new consumer wash products.
    • Quantitative analysis of the morphological changes of the pubic symphyseal face and the auricular surface and implications for age at death estimation

      Villa, C.; Buckberry, Jo; Cattaneo, C.; Frohlich, B.; Lynnerup, N. (May 2015)
      Age estimation methods are often based on the age-related morphological changes of the auricular surface and the pubic bone. In this study, a mathematical approach to quantify these changes has been tested analyzing the curvature variation on 3D models from CT and laser scans. The sample consisted of the 24 Suchey–Brooks (SB) pubic bone casts, 19 auricular surfaces from the Buckberry and Chamberlain (BC) “recording kit” and 98 pelvic bones from the Terry Collection (Smithsonian Institution). Strong and moderate correlations between phases and curvature were found in SB casts (ρ 0.60–0.93) and BC “recording kit” (ρ 0.47–0.75), moderate and weak correlations in the Terry Collection bones (pubic bones: ρ 0.29–0.51, auricular surfaces: ρ 0.33–0.50) but associated with large individual variability and overlap of curvature values between adjacent decades. The new procedure, requiring no expert judgment from the operator, achieved similar correlations that can be found in the classic methods.
    • QUASI: A general purpose implementation of the QM/MM approach and its application to problems in catalysis

      Kendrick, John; Sherwood, P.; De Vries, A.H.; Guest, M.F.; Schreckenbach, G.; Catlow, C.R.A.; French, S.A.; Sokol, A.A.; Bromley, S.T.; Thiel, W.; et al. (2003)
      We describe the work of the European project QUASI (Quantum Simulation in Industry, project EP25047) which has sought to develop a flexible QM/MM scheme and to apply it to a range of industrial problems. A number of QM/MMapproaches were implemented within the computational chemistry scripting system, ChemShell, which provides the framework for deploying a variety of independent program packages. This software was applied in several large-scale QM/MM studies which addressed the catalytic decomposition of N2O by Cu-containing zeolites, the methanol synthesis reaction catalysed by Cu clusters supported on ZnO surfaces, and the modelling of enzyme structure and reactivity.
    • The RAC1 target NCKAP1 plays a crucial role in progression of BRAF/PTEN -driven melanoma in mice

      Swaminathan, Karthic; Campbell, A.; Papalazarou, V.; Jaber-Hijazi, F.; Nixon, C.; McGhee, E.; Strathdee, D.; Sansom, O.J.; Machesky, L.M. (2020)
      BRAF V600E is the most common driver mutation in human cutaneous melanoma and is frequently accompanied by loss of the tumor suppressing phosphatase PTEN. Recent evidence suggests a co-operative role for RAC1 activity in BRAF V600E -driven melanoma progression and drug resistance. However, the underlying molecular mechanisms and the role of RAC1 downstream targets are not well explored. Here, we examine the role of the NCKAP1 subunit of the pentameric cytoskeletal SCAR/WAVE complex, a major downstream target of RAC1, in a mouse model of melanoma driven by BRAF V600E; PTEN loss. The SCAR/WAVE complex is the major driver of lamellipodia formation and cell migration downstream of RAC1 and depends on NCKAP1 for its integrity. Targeted deletion of Nckap1 in the melanocyte lineage delayed tumor onset and progression of a mutant Braf ; Pten loss driven melanoma mouse model. Nckap1 depleted tumors displayed fibrotic stroma with increased collagen deposition concomitant with enhanced immune infiltration. Nckap1 loss slowed proliferation and tumor growth, highlighting a role in cell cycle progression. Altogether, we propose that NCKAP1-orchestrated actin polymerization is essential for tumor progression and maintenance of tumor tissue integrity in a mutant Braf ; Pten loss driven mouse model for melanoma.
    • Racemic compound versus conglomerate: concerning the crystal chemistry of the triazoylketone, 1-(4-chlorophenyl)-4,4- dimethyl-2-(1H-1,2,4-triazol-1-yl)pentan-3-one

      Davey, R.J.; Sadiq, G.; Seaton, Colin C.; Pritchard, R.G.; Coquerel, G.; Rougeot, C. (2014-06-07)
      The triazoylketone discussed in this paper crystallises from racemic solutions as a conglomerate. Here, we report the ternary phase diagram confirming the conglomerate behaviour of this molecule. Through computation we also explore the underlying reasons for the absence of a racemic compound in this system and the evident epitaxial crystallisation leading to crystals of almost racemic compositions but which retain the crystal structure of the pure enantiomer.
    • Radiographically recognizable? An investigation into the appearance of osteomalacic pseudofractures

      Jennings, E.; Buckberry, Jo; Brickley, M.B. (2018-12)
      Pseudofractures, lucent bands that occur due to a build-up of osteoid, are a key feature of osteomalacia. In paleopathology, pseudofractures are often marked by small, linear cracks in the cortex of the bone surrounded by irregular, bony spicule formation. Radiography can be used to help diagnose pseudofractures, both clinically and in paleopathology. A detailed understanding of the radiographic appearance of pseudofractures and their development is, therefore, necessary to aid a diagnosis of vitamin D deficiency. The present study examined the clinical literature to determine current ideas on the appearance of pseudofractures with the aim of applying this knowledge to paleopathology. A radiographic study of the characteristics of pseudofractures was performed on five individuals with clear skeletal features of osteomalacia from archaeological sites in Canada and the United Kingdom dating to the medieval period (5th to 15th centuries) and the 18th to 19th century. Results show that the radiographic appearance of pseudofractures could potentially reveal information about the cause of the deficiency and the chronicity of pseudofractures. This type of information has the potential to further our understanding of the lived experiences of archaeological individuals with osteomalacia.
    • Radiography in Palaeopathology: Where Next?

      Buckberry, Jo; O'Connor, Sonia A. (2007)
      Radiography has frequently been used during palaeopathological research, and plays an important role in the differential diagnosis of many diseases, including Paget¿s disease and carcinomas. Traditionally, radiographs were taken in hospitals with clinical equipment. However industrial radiography techniques have gradually become more commonly used, as their superior image quality and improved potential for diagnoses become recognised. The introduction of radiographic scanners has facilitated the digitisation of these images for dissemination and publication. However this is not all that radiographic digitisation can offer the researcher. Digital image processing (DIP) allows the researcher to focus on an area of interest and to adjust the brightness and contrast of the captured image. This allows the investigation of areas of high radio-opacity and radio-lucency, providing detailed images of the internal structures of bone and pathological lesions undetectable by the naked eye. In addition 3D effects, edge enhancement and sharpening algorithms, available through commonly used image processing software, can be very effective in enhancing the visibility of specific features. This paper will reveal how radiographic digitisation and manipulation can enhance radiographic images of palaeopathological lesions and potentially further our understanding of the bony manifestations of disease.
    • RAFT dispersion polymerization : a method to tune the morphology of thymine-containing self-assemblies

      Kang, Y.; Pitto-Barry, Anaïs; Maitland, A.; O'Reilly, R.K. (2015-07-21)
      The synthesis and self-assembly of thymine-containing polymers were performed using RAFT dispersion polymerization. A combination of microscopy and scattering techniques was used to analyze the resultant complex morphologies. The primary observation from this study is that the obtained aggregates induced during the polymerization were well-defined despite the constituent copolymers possessing broad dispersities. Moreover, a variety of parameters, including the choice of polymerization solvent, the degree of polymerization of both blocks and the presence of an adenine-containing mediator, were observed to affect the resultant size and shape of the assembly.
    • Raman and SEM analysis of a biocolonised hot spring travertine terrace in Svalbard, Norway

      Jorge Villar, Susana E.; Benning, L.G.; Edwards, Howell G.M.; AMASE team (2007)
      A profile across 8 layers from a fossil travertine terrace from a low temperature geothermal spring located in Svalbard, Norway has been studied using both Raman spectroscopy and SEM (Scanning Electron Microscopy) techniques to identify minerals and organic life signals. Calcite, anatase, quartz, haematite, magnetite and graphite as well as scytonemin, three different carotenoids, chlorophyll and a chlorophyll-like compound were identified as geo- and biosignatures respectively, using 785 and/or 514 nm Raman laser excitation wavelengths. No morphological biosignatures representing remnant microbial signals were detected by high-resolution imaging, although spectral analyses indicated the presence of organics. In contrast, in all layers, Raman spectra identified a series of different organic pigments indicating little to no degradation or change of the organic signatures and thus indicating the preservation of fossil biomarker compounds throughout the life time of the springs despite the lack of remnant morphological indicators. With a view towards planetary exploration we discuss the implications of the differences in Raman band intensities observed when spectra were collected with the different laser excitations. We show that these differences, as well as the different detection capability of the 785 and 514 nm laser, could lead to ambiguous compound identification. We show that the identification of bio and geosignatures, as well as fossil organic pigments, using Raman spectroscopy is possible. These results are relevant since both lasers have been considered for miniaturized Raman spectrometers for planetary exploration.
    • Raman spectroscopic analyses of preserved historical specimens of human hair attributed to Robert Stephenson and Sir Isaac Newton

      Edwards, Howell G.M.; Hassan, N.F.; Wilson, Andrew S. (2004)
      The Raman spectra of two historical specimens of human hair attributed to the engineer Robert Stephenson and scientist Sir Isaac Newton, preserved in private collections are reported. Comparisons are made with the Raman spectra of modern hair specimens and with hair from archaeological excavations. The hair spectra collected with a laser excitation of 785 nm are of a better quality than those collected using 1064 nm. The historical hair specimens are remarkably well-defined spectroscopically in terms of the amide I vibrational mode and the ν(SS), ascribed to a predominantly gauche–gauche–gauche CSSC conformation. The contrast with degraded hair specimens recovered from archaeological excavations is striking. The presence of a weak feature near 2590 cm−1 in the hair samples attributed to a ν(SH) vibration could be indicative of a reduction process operative on the CSSC cystine keratotic linkages and a possible origin of this is bacterial biodegradation identified histologically. This study demonstrates the molecular information available from non-destructive Raman spectroscopic analysis from single hair shafts or small bundles of fibres which complements information available from histological and destructive analytical techniques for rare biological specimens subjected to conservation or curation procedures in museums or private collections.
    • Raman spectroscopic analysis of human remains from a seventh century cist burial on Anglesey, UK

      Edwards, Howell G.M.; Wilson, Andrew S.; Nik Hassan, N.F.; Davidson, A.; Burnett, A. (2006-02)
      Specimens from human remains exhibiting unusual preservation excavated from a seventh century stone cist burial at Towyn y Capel in Anglesey, UK, have been analysed using Raman spectroscopy with near-infrared laser excitation at 1,064 and 785 nm. Specimens of hair and bone provided evidence for severe degradation and microbial colonisation. The deposits within the stone cist showed that some microbially mediated compounds had been formed. Analysis of crystals found at the interface between the hair and the skeletal neck vertebrae revealed a mixture of newberyite and haematite, associated with decomposition products of the hair and bone. An interesting differential degradation was noted in the specimens analysed which could be related to the air-void and the presence of plant root inclusions into the stone cist. This is the first time that Raman spectroscopy has been used in the forensic archaeological evaluation of burial remains in complex and dynamic environments.
    • Raman spectroscopic analysis of the effect of the lichenicolous fungus Xanthoriicola physciae on its lichen host

      Edwards, Howell G.M.; Seaward, Mark R.D.; Preece, T.F.; Jorge Villar, Susana E.; Hawksworth, D.L. (2016)
      Lichenicolous (lichen-dwelling) fungi have been extensively researched taxonomically over many years, and phylogenetically in recent years, but the biology of the relationship between the invading fungus and the lichen host has received limited attention, as has the effects on the chemistry of the host, being difficult to examine in situ. Raman spectroscopy is an established method for the characterization of chemicals in situ, and this technique is applied to a lichenicolous fungus here for the first time. Xanthoriicola physciae occurs in the apothecia of Xanthoria parietina, producing conidia at the hymenium surface. Raman spectroscopy of apothecial sections revealed that parietin and carotenoids were destroyed in infected apothecia. Those compounds protect healthy tissues of the lichen from extreme insolation and their removal may contribute to the deterioration of the apothecia. Scytonemin was also detected, but was most probably derived from associated cyanobacteria. This work shows that Raman spectroscopy has potential for investigating changes in the chemistry of a lichen by an invading lichenicolous fungus.
    • Raman spectroscopic and structural investigation of 1,4-diphenylbuta-1,3-diene and selected monomethyl and dimethyl substituted homologues

      Bowen, Richard D.; Edwards, Howell G.M.; Waller, Zoe A.E. (2006)
      The Raman and mass spectra of 1,4-diphenylbuta-1,3-diene and several of its monomethyl and dimethyl homologues are reported and discussed, with a view to developing a spectroscopic protocol for detecting the presence and position of a methyl group in these compounds. Raman spectroscopy and mass spectrometry are shown to provide complementary information, by which the four available monomethyl homologues may be readily distinguished from each other and 1,4-diphenylbuta-1,3-diene itself. The utility of these 1,4-diarylbutadienes as model compounds for carotenoids and related materials, which may serve as indicators of extinct or extant extraterrestrial life, is considered.