Search results for "Ultraviolet"
showing 10 items of 853 documents
A European multicentre photopatch test study
2012
The two most common agent groups currently responsible for photoallergic contact dermatitis (PACD) are organic ultraviolet (UV) absorbers in sunscreens and topical nonsteroidal anti-inflammatory drugs (NSAIDs). However, availability of information on the photoallergenic potential of these agents is scarce.To obtain current information on the frequency of PACD to 19 organic UV absorbers and five topical NSAIDs, including newer agents, in common usage in Europe.A prospective, multicentre photopatch test study was conducted with 1031 patients attending for investigation of suspected PACD in 30 centres across 12 European countries.A total of 346 PACD reactions in 200 (19·4%) subjects occurred. …
Psoriatic arthritis onset in psoriatic patients receiving UV phototherapy in Italy
2018
Abstract BACKGROUND: Psoriasis is a chronic, recurrent, and immune-mediated inflammatory disease that affects 2-3% of the world population. A substantial proportion of patients with psoriasis, approximately 40 %, develop a form of inflammatory arthritis known as psoriatic arthritis (PsA), the arthritis follows the development of psoriasis, and it will develop simultaneously or possibly before the appearance of skin lesions. The presence of PsA indicates a need for more active intervention rather than purely topical therapies or UV-based therapies. The aim of this multicenter, retrospective, epidemiological study was to estimate the incidence of PsA in psoriatic patients receiving UV treatme…
Development and application to clinical practice of a validated HPLC method for the analysis of β-glucocerebrosidase in Gaucher disease.
2014
The main objective of our study is to develop a simple, fast and reliable method for measuring ß-glucocerebrosidase activity in Gaucher patients leukocytes in clinical practice. This measurement may be a useful marker to drive dose selection and early clinical decision making of enzyme replacement therapy. We measure the enzyme activity by high-performance liquid chromatography with ultraviolet detection and 4-nitrophenyl-ß-d-glucopyranoside as substrate. A cohort of eight Gaucher patients treated with enzyme replacement therapy and ten healthy controls were tested; median enzyme activity values was 20.57mU/ml (interquartile range 19.92-21.53mU/ml) in patients and mean was 24.73mU/ml (24.12…
Is ultraviolet exposure acquired at work the most important risk factor for cutaneous squamous cell carcinoma? Results of the population-based case-c…
2018
Background Squamous cell carcinoma (SCC) is among the most frequent types of cancer constituting a significant public health burden. Prevention strategies focus on limiting UV-exposure during leisure time. However, the relative impact of occupational and non-occupational UV-exposure for SCC occurrence is unclear. Objectives To investigate the association between occupational and non-occupational UV-exposure with SCC in a multicenter population-based case-control study hypothesizing that high occupational UV-exposure increases the risk for SCC. Methods Consecutive patients with incident SCC (n=632) were recruited from a German national dermatology network. Population-based controls (n=996) w…
Spectral transmission of the pig lens: Effect of ultraviolet A+B radiation
2014
Summary Objective To determine the spectral transmission curve of the crystalline lens of the pig. To analyse how this curve changes when the crystalline lens is irradiated with ultraviolet A + B radiation similar to that of the sun. To compare these results with literature data from the human crystalline lens. Procedures We used crystalline lenses of the common pig from a slaughterhouse, i.e. genetically similar pigs, fed with the same diet, and slaughtered at six months old. Spectral transmission was measured with a Perkin-Elmer Lambda 35 UV/VIS spectrometer. The lenses were irradiated using an Asahi Spectra Lax-C100 ultraviolet source, which made it possible to select the spectral emissi…
Halloysite/Keratin Nanocomposite for Human Hair Photoprotection Coating
2020
We propose a novel keratin treatment of human hair by its aqueous mixtures with natural halloysite clay nanotubes. The loaded clay nanotubes together with free keratin produce micrometer-thick protective coating on hair. First, colloidal and structural properties of halloysite/keratin dispersions and the nanotube loaded with this protein were investigated. Above the keratin isoelectric point (pH = 4), the protein adsorption into the positive halloysite lumen is favored because of the electrostatic attractions. The ζ-potential magnitude of these core-shell particles increased from -35 (in pristine form) to -43 mV allowing for an enhanced colloidal stability (15 h at pH = 6). This keratin-cla…
Determination of alcohols in essential oils by liquid chromatography with ultraviolet detection after chromogenic derivatization
2013
Abstract An HPLC-UV method to determine compounds having a hydroxyl functional group in plant essential oils is developed. The sample is diluted with 1,4-dioxane and the analytes are derivatized with phthalic anhydride. The derivatives (phthalates hemiesters) are separated on a C8 column using an acetonitrile (ACN)/water gradient. Separation conditions were optimized using the DryLab® method development software. For the alcohols and phenols present in mint and rose essential oils, optimization led to a ca. 40 min gradient time and a column temperature of 8 °C. The alcohol and its derivatives were identified using HPLC with mass spectrometry (MS) detection. A large sensitivity enhancement w…
A multifunctional bioconjugate module for versatile photoaffinity labeling and click chemistry of RNA
2011
A multifunctional reagent based on a coumarin scaffold was developed for derivatization of naive RNA. The alkylating agent N3BC [7-azido-4-(bromomethyl)coumarin], obtained by Pechmann condensation, is selective for uridine. N3BC and its RNA conjugates are pre-fluorophores which permits controlled modular and stepwise RNA derivatization. The success of RNA alkylation by N3BC can be monitored by photolysis of the azido moiety, which generates a coumarin fluorophore that can be excited with UV light of 320 nm. The azidocoumarin-modified RNA can be flexibly employed in structure-function studies. Versatile applications include direct use in photo-crosslinking studies to cognate proteins, as dem…
Kinetics of gamma-H2AX focus formation upon treatment of cells with UV light and alkylating agents.
2008
Histone H2AX is rapidly phosphorylated in response to DNA double-strand breaks (DSBs) induced by ionizing radiation (IR). Here we show that DNA damage induced by alkylating agents [methyl methanesulfonate (MMS) and N-methyl-N'-nitro-N-nitrosoguanidine (MNNG)] and ultraviolet light (UV-C) leads to a dose and time dependent accumulation of phosphorylated H2AX (gamma-H2AX). Time course experiments revealed that the number of gamma-H2AX foci reached peak levels 8 hr after MMS or MNNG treatment and declined to almost control values within 24 hr after exposure. Upon UV-C treatment, a biphasic response was observed with a maximum 12 hr after treatment. In 43-3B cells deficient in nucleotide excisi…
Activation of c-Jun N-terminal kinase 1 by UV irradiation is inhibited by wortmannin without affecting c-iun expression.
1999
Activation of c-Jun N-terminal kinases (JNKs)/stress-activated protein kinases is an early response of cells upon exposure to DNA-damaging agents. JNK-mediated phosphorylation of c-Jun is currently understood to stimulate the transactivating potency of AP-1 (e.g., c-Jun/c-Fos; c-Jun/ATF-2), thereby increasing the expression of AP-1 target genes. Here we show that stimulation of JNK1 activity is not a general early response of cells exposed to genotoxic agents. Treatment of NIH 3T3 cells with UV light (UV-C) as well as with methyl methanesulfonate (MMS) caused activation of JNK1 and an increase in c-Jun protein and AP-1 binding activity, whereas antineoplastic drugs such as mafosfamide, mito…