UV exclusion Dotaz Zobrazit nápovědu
BACKGROUND AND AIMS: UVB radiation can rapidly induce gene regulation leading to cumulative changes for plant physiology and morphology. We hypothesized that a transgenerational effect of chronic exposure to solar short UV modulates the offspring's responses to UVB and blue light, and that the transgenerational effect is genotype dependent. METHODS: We established a factorial experiment combining two Vicia faba L. accessions, two parental UV treatments (full sunlight and exclusion of short UV, 290-350 nm), and four offspring light treatments from the factorial combination of UVB and blue light. The accessions were Aurora from southern Sweden, and ILB938 from Andean region of Colombia and Ecuador. KEY RESULTS: The transgenerational effect influenced morphological responses to blue light differently in the two accessions. In Aurora, when UVB was absent, blue light increased shoot dry mass only in plants whose parents were protected from short UV. In ILB938, blue light increased leaf area and shoot dry mass more in plants whose parents were exposed to short UV than those that were not. Moreover, when the offspring was exposed to UVB, the transgenerational effect decreased in ILB938 and disappeared in Aurora. For flavonoids, the transgenerational effect was detected only in Aurora: parental exposure to short UV was associated with a greater induction of total quercetin in response to UVB. Transcript abundance was higher in Aurora than in ILB938 for both CHALCONE SYNTHASE (99-fold) and DON-GLUCOSYLTRANSFERASE 1 (19-fold). CONCLUSIONS: The results supported both hypotheses. Solar short UV had transgenerational effects on progeny responses to blue and UVB radiation, and they differed between the accessions. These transgenerational effects could be adaptive by acclimation of slow and cumulative morphological change, and by early build-up of UV protection through flavonoid accumulation on UVB exposure. The differences between the two accessions aligned with their adaptation to contrasting UV environments.
Expozice roztoku insulinu UV zářením o vlnové délce 250 nm způsobuje v jeho struktuře přeměnudisulfidických skupin na volné SH skupiny, které mají vysokou afinitu pro značení 99m Tc. Množstvíkoncových SH závisí na době ozařování. HPLC analýza ukázala, že po ozařování insulinu (intenzitapřibližně 500 mW . cm 2 ) po dobu 15; 30; 60 a 120 min zůstává ve vzorcích 34%, 25%, 10% a 2%původního množství insulinu. Tyto hodnoty odpovídají množství fotoaktivací uvolněných SH skupin,které bylo stanoveno použitím Ellmanova činidla. Produkt degradovaného vepřového insulinu bylznačen 99m Tc použitím redox polymeru RP G25 IDA při pH 6,8–7,9 po dobu 15 min při teplotěmístnosti. Radiochemická čistota značeného produktu byla vyšší než 96 %. Insulin a jeho degradačníprodukty byly hodnoceny vylučovací chromatografií. Biodistribuce značených látek v laboratorníchzvířatech vykazovala nejvíce radioaktivity v ledvinách a játrech. U potkanů s experimentálně vyvo-laným diabetem nebyla zjištěna specifická biodistribuce těchto značených degradačních produktů.
Irradiation with UV light at a wavelength of 250 nm allows to convert disulphidic groups in thestructure of insulin to free SH groups with high affinity to direct labelling with 99m Tc. The amountof terminal SH groups depends on irradiation time. HPLC analysis revealed that while 34% of theoriginal amount of insulin was present after 15 minutes of irradiation (approx. intensity of500 mW.cm 2 ), the amounts were 25%, 10%, and 2% after 30; 60, and 120 minutes, respectively. Theseresults correlate with the amount of SH groups released by photoactivation measured using Ellman’sreagent. The product of the degraded porcine insulin was labelled with 99m Tc using the redox polymerRP G25 IDA under the following conditions: pH 6.8–7.9, labelling time 15 minutes, room tempera-ture. Radiochemical purify of the labelled product was higher than 96 %. Insulin and products ofits degradation were evaluated by means of size exclusion chromatography (SEC). The biodistribu-tion of the labelled substances in laboratory animals showed activity mostly in the kidneys and liver.No specific biodistribution of the labelled products was observed in rats with experimentally induceddiabetes.
We induced the B-to-A conformational transition by ethanol in a linearized pUC19 DNA. A primer extension method was used in combination with UV light irradiation to follow the transition, based on pausing of DNA synthesis due to the presence of damaged bases in the template. Primer extension data highly correlated with the results of another method monitoring the B-A transition, i.e. inhibition of restriction endonuclease cleavage of UV light-irradiated DNA. Primer extension enabled us to locate damaged nucleotides within the region of interest. Most damaged nucleotides were located in B-form trimers, exclusively containing both pyrimidine bases (TTC, TCT, CTC, and CTT), and in a cytosine tetramer. The amount of damaged bases decreased in the course of B-A transition. Some of the damage even disappeared in the A-form, which mainly concerns the C(4) and C(3) blocks. The cleavage was nearly restored in the A-form within this region (Eco88I). On the contrary the decrease of damage was less significant with thymine dimers, only dropping to 50-60% of the B-form level. Consequently, the cleavage with EcoRI and HindIII remained mostly as before the transition (75% and 60% of uncleaved DNA preserved). We found significant differences in the B- and A-form pattern of UV light-damaged bases within the same region (polylinker) of DNA embedded within long (plasmid) or short (127 bp fragment) DNA molecules. The B-A transition of the fragment was found less cooperative than with linearized plasmid, which was confirmed by both CD spectroscopy and restriction cleavage inhibition.
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- A-DNA chemie účinky záření MeSH
- cirkulární dichroismus MeSH
- DNA chemie účinky záření MeSH
- financování organizované MeSH
- fotochemie MeSH
- konformace nukleové kyseliny účinky záření MeSH
- molekulární sekvence - údaje MeSH
- plazmidy genetika MeSH
- restrikční enzymy metabolismus MeSH
- sekvence nukleotidů MeSH
- ultrafialové záření MeSH
BACKGROUND AND OBJECTIVES: The severity of multiple sclerosis (MS) varies widely among individuals. Understanding the determinants of this heterogeneity will help clinicians optimize the management of MS. The aim of this study was to investigate the association between latitude of residence, UV B radiation (UVB) exposure, and the severity of MS. METHODS: This observational study used the MSBase registry data. The included patients met the 2005 or 2010 McDonald diagnostic criteria for MS and had a minimum dataset recorded in the registry (date of birth, sex, clinic location, date of MS symptom onset, disease phenotype at baseline and censoring, and ≥1 Expanded Disability Status Scale score recorded). The latitude of each study center and cumulative annualized UVB dose at study center (calculated from National Aeronautics and Space Administration's Total Ozone Mapping Spectrometer) at ages 6 and 18 years and the year of disability assessment were calculated. Disease severity was quantified with Multiple Sclerosis Severity Score (MSSS). Quadratic regression was used to model the associations between latitude, UVB, and MSSS. RESULTS: The 46,128 patients who contributed 453,208 visits and a cumulative follow-up of 351,196 patient-years (70% women, mean age 39.2 ± 12 years, resident between latitudes 19°35' and 56°16') were included in this study. Latitude showed a nonlinear association with MS severity. In latitudes <40°, more severe disease was associated with higher latitudes (β = 0.08, 95% CI 0.04-0.12). For example, this translates into a mean difference of 1.3 points of MSSS between patients living in Madrid and Copenhagen. No such association was observed in latitudes <40° (β = -0.02, 95% CI -0.06 to 0.03). The overall disability accrual was faster in those with a lower level of estimated UVB exposure before the age of 6 years (β = - 0.5, 95% CI -0.6 to 0.4) and 18 years (β = - 0.6, 95% CI -0.7 to 0.4), as well as with lower lifetime UVB exposure at the time of disability assessment (β = -1.0, 95% CI -1.1 to 0.9). DISCUSSION: In temperate zones, MS severity is associated with latitude. This association is mainly, but not exclusively, driven by UVB exposure contributing to both MS susceptibility and severity.
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- lidé MeSH
- posuzování pracovní neschopnosti MeSH
- registrace MeSH
- roztroušená skleróza * diagnóza epidemiologie MeSH
- stupeň závažnosti nemoci MeSH
- ultrafialové záření škodlivé účinky MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- pozorovací studie MeSH
BACKGROUND: Wood science and nanomaterials science interact together in two different aspects; a) fabrication of lignocellulosic nanomaterials derived from wood and plant-based sources and b) surface or bulk wood modification by nanoparticles. In this review, we attempt to visualize the impact of nanoparticles on the wood coating and preservation treatments based on a thorough registration of the patent databases. METHOD: The study was carried out as an overview of the scientifically most followed trends on nanoparticles utilization in wood science and wood protection depicted by recent universal filed patents. This review is exclusively targeted on the solid (timber) wood as a subject material. RESULTS: Utilization of mainly metal nanoparticles as photoprotection, antibacterial, antifungal, antiabrasive and functional component on wood modification treatments was found to be widely patented. Additionally, an apparent minimization in the emission of volatile organic compounds (VOCs) has been succeeded. CONCLUSION: Bulk wood preservation and more importantly, wood coating, splay the range of strengthening wood dimensional stability and biological degradation, against moisture absorption and fungi respectively. Nanoparticle materials have addressed various issues of wood science in a more efficient and environmental way than the traditional methods. Nevertheless, abundant tests and regulations are still needed before industrializing or recycling these products.
Práce se zabývá chromatografickými separacemi nově připravených látek, derivátů aryloxyaminopropanolu.Deriváty představují tři homologické řady o čtyřech uhlících a čtyři skupiny izomerůpolohových (methyl- až butyl- v polohách 2-, 3- a 4-). Pro adsorpční chromatografii na tenké vrstvěbyla jako stacionární fáze použita fólie Silufol®UV 254, pro rozdělovací chromatografii, komerčněvyráběné skleněné desky DC Fertigplatten MERCK RP-8 F254 S. Vysokoúčinnou kapalinovouchromatografií byly děleny polohové izomery na koloně SupelkosilTM ABZ+PLUS. Mobilní fází bylmethanol a acetonitril v odstupňovaných poměrech s vodou a vyzkoušeny byly různé rychlostiprůtoku mobilní fáze. Rozdělovací chromatografií, stanovením rozdělovacího koeficientu v soustavěoktanol-voda a z hodnot kapacitních faktorů k’ látek byla hodnocena jejich lipofilita.
The paper deals with chromatographic separations of newly prepared substances, aryloxyaminopropanolderivatives. The derivatives represent three homological series of four carbons and fourgroups of positional isomers (methyl- to butyl- in positions 2-, 3, and 4-). Thin-layer adsorptionchromatography employed the foil Silufol® UV 254 as the stationary phase and partition chromatography,commercially produced glass plates DC Fertigplatten MERCK RP-8 F254 S. High-performanceliquid chromatography was used to separate positional isomers on the column SupelkosilTMABZ+PLUS. The mobile phase was methanol and acetonitrile in graded rations with water andvarious flow rates of the mobile phase were tested. Partition chromatography, determination ofpartition coefficient in the system octanol-water, and the values of capacity factors k’ of thesubstances was employed to evaluate their lipophilicity.
The activity of the tumor suppressor protein p53 is controlled by a balance between E3-ligase mediated p53 protein degradation and protein kinase-mediated assembly of p53:p300 transcription machinery. Genetic studies in mice have shown that mutation of the CK2 phospho-acceptor site in p53 increases UV-induced skin cancer formation,(11) highlighting an unexpected role for p53 phosphorylation in mediating p53-dependent tumor suppression. However, it is not known in which cell types CK2-mediated phosphorylation of p53 occurs. Using human skin as a model to determine whether there is cell-selectivity in modulating p53 phosphorylation, we have found a selective induction of p53 phosphorylation at the CK2-site in the basal cells of UV irradiated human skin. Dual-immunofluorescence also revealed that Ser392 and Ser15 phosphorylation of p53 also occur in the same basal cells, although often within distinct regions of the nucleus. Given that p63alphaDeltaN is required for p53 activation after DNA damage, we examined and found a high proportion of cells co-express p63alphaDeltaN and CK2-phosphorylated p53 after UV-irradiation. As controls, the proliferation marker Ki67 and p63alphaDeltaN generally exhibit mutually exclusive expression. These data identify a physiological model with which to identify signaling pathways that mediate cross-talk between p63alphaDeltaN and activating p53 kinase pathways after DNA damage in basal cell populations.
- MeSH
- DNA vazebné proteiny metabolismus MeSH
- fosforylace MeSH
- kaseinkinasa II * fyziologie MeSH
- kmenové buňky cytologie metabolismus MeSH
- kůže * metabolismus účinky záření MeSH
- lidé MeSH
- myši MeSH
- nádorové supresorové proteiny metabolismus MeSH
- nádorový supresorový protein p53 chemie metabolismus MeSH
- poškození DNA MeSH
- progrese nemoci MeSH
- regulace genové exprese * MeSH
- signální transdukce MeSH
- trans-aktivátory metabolismus MeSH
- transkripční faktory MeSH
- ubikvitinligasy metabolismus MeSH
- ultrafialové záření MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- práce podpořená grantem MeSH
Multimodal imaging-therapeutic nanoprobe TiO(2)@RhdGd was prepared and successfully used for in vitro and in vivo cell tracking as well as for killing of cancer cells in vitro. TiO(2) nanoparticles were used as a core for phosphonic acid modified functionalities, responsible for contrast in MRI and optical imaging. The probe shows high (1)H relaxivity and relaxivity density values. Presence of fluorescent dye allows for visualization by means of fluorescence microscopy. The applicability of the probe was studied, using mesenchymal stem cells, cancer HeLa cells, and T-lymphocytes. The probe did not exhibit toxicity in any of these systems. Labeled cells were successfully visualized in vitro by means of fluorescence microscopy and MRI. Furthermore, it was shown that the probe TiO(2)@RhdGd can be changed into a cancer cell killer upon UV light irradiation. The above stated results represent a valuable proof of a principle showing applicability of the probe design for diagnosis and therapy.
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- afinitní značky chemická syntéza chemie farmakologie MeSH
- fluorescenční barviva chemická syntéza chemie farmakologie MeSH
- fluorescenční mikroskopie MeSH
- gadolinium MeSH
- HeLa buňky MeSH
- komplexní sloučeniny chemická syntéza chemie farmakologie MeSH
- kyseliny fosforité chemická syntéza chemie farmakologie MeSH
- lidé MeSH
- magnetická rezonanční tomografie MeSH
- mezenchymální kmenové buňky metabolismus MeSH
- myši MeSH
- nanočástice MeSH
- protinádorové látky chemická syntéza chemie farmakologie MeSH
- screeningové testy protinádorových léčiv MeSH
- T-lymfocyty metabolismus MeSH
- titan chemie farmakologie MeSH
- ultrafialové záření MeSH
- viabilita buněk účinky léků MeSH
- vztahy mezi strukturou a aktivitou MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Carboplatin, an analogue of "classical" cis-diamminedichloridoplatinum(II) (cisplatin), is a widely used second-generation platinum anticancer drug. Cytotoxicity of cisplatin and carboplatin is mediated by platinum-DNA adducts. Markedly higher concentrations of carboplatin are required, and the rate of adduct formation is considerably slower. The reduced toxic effects in tumor cells and a more acceptable side-effect profile are attributable to the lower reactivity of carboplatin with nucleophiles, since the cyclobutanedicarboxylate ligand is a poorer leaving group than the chlorides in cisplatin. Recently, platinum complexes were shown to be particularly attractive as potential photochemotherapeutic anticancer agents. Selective photoactivation of platinum complexes by irradiation of cancer cells may avoid enhancement of toxic side-effects, but may increase toxicity selectively in cancer cells and extend the application of photoactivatable platinum complexes to resistant cells and to a wider range of cancer types. Therefore, it was of interest to examine whether carboplatin can be affected by irradiation with light to the extent that its DNA binding and cytotoxic properties are altered. We have found that carboplatin is converted to species capable of enhanced DNA binding by UVA irradiation and consequently its toxicity in cancer cells is markedly enhanced. Recent advances in laser and fiber-optic technologies make it possible to irradiate also internal organs with light of highly defined intensity and wavelength. Thus, carboplatin is a candidate for use in photoactivated cancer chemotherapy.
- MeSH
- DNA chemie účinky léků MeSH
- fotochemické procesy účinky záření MeSH
- karboplatina chemie farmakologie účinky záření toxicita MeSH
- kinetika MeSH
- lidé MeSH
- nádorové buňky kultivované MeSH
- plazmidy MeSH
- poškození DNA účinky léků MeSH
- proliferace buněk účinky léků MeSH
- protinádorové látky chemie farmakologie účinky záření toxicita MeSH
- screeningové testy protinádorových léčiv MeSH
- skot MeSH
- ultrafialové záření MeSH
- vazebná místa účinky léků MeSH
- viabilita buněk účinky léků MeSH
- vztah mezi dávkou a účinkem léčiva MeSH
- vztahy mezi strukturou a aktivitou MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- skot MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
