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    Wyświetlanie 1-13 z 13
    Tytuł:
    Ultra-shallow nitrogen plasma implantation for ultra-thin silicon oxynitride (SiOxNy) layer formation
    Autorzy:
    Bieniek, T.
    Beck, R. B.
    Jakubowski, A.
    Kudła, A.
    Powiązania:
    https://bibliotekanauki.pl/articles/308830.pdf
    Data publikacji:
    2005
    Wydawca:
    Instytut Łączności - Państwowy Instytut Badawczy
    Tematy:
    MOS technology
    plasma processing
    shallow implantation
    radiation damage
    Opis:
    The radiation damage caused by low energy r.f. plasmas has not been, to our knowledge, studied so far in the case of symmetric planar plasma reactors that are usually used for PECVD processes. The reason is that, unlike nonsymmetrical RIE reactors, such geometry prevents, basically, high-energy ion bombardment of the substrate. In this work, we present the results of experiments in which we have studied the influence of plasma processing on the state of silicon surface. Very low temperature plasma oxidation has been used as a test of silicon surface condition. The obtained layers were then carefully measured by spectroscopic ellipsometry, allowing not only the thickness to be determined accurately, but also the layer composition to be evaluated. Different plasma types, namely N2, NH3 and Ar, were used in the first stage of the experiment, allowing oxidation behaviour caused by the exposure to those plasma types to be compared in terms of relative differences. It has been clearly proved that even though the PECVD system is believed to be relatively safe in terms of radiation damage, in the case of very thin layer processing (e.g., ultra-thin oxynitride layers) the effects of radiation damage may considerably affect the kinetics of the process and the properties of the formed layers.
    Źródło:
    Journal of Telecommunications and Information Technology; 2005, 1; 70-75
    1509-4553
    1899-8852
    Pojawia się w:
    Journal of Telecommunications and Information Technology
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Irradiation of austenitic steel 10Cr12Mn14Ni4AlMo and titanium alloy Ti-Al-V by pulsed streams of fast nitrogen ions and plasma in a dense plasma focus
    Autorzy:
    Gribkov, V. A.
    Pimenov, V. N.
    Roschupkin, V. V.
    Maslyaev, S. A.
    Demina, E. V.
    Lyakhovitsky, M. M.
    Dubrovsky, A. V.
    Sasinovskaya, I. P.
    Powiązania:
    https://bibliotekanauki.pl/articles/971548.pdf
    Data publikacji:
    2012
    Wydawca:
    Instytut Chemii i Techniki Jądrowej
    Tematy:
    radiation
    damage
    phase transition
    nanohardness
    dense plasma focus (DPF)
    Opis:
    Austenitic steel 10Cr12Mn14Ni4AlMo and Ti-4Al-3V alloy were irradiated with nanosecond pulsed nitrogen ion and plasma streams in plasma focus devices. The two different modes of the treatment were applied: high power density (greater-than or equal to 10 8 W/cm2) irradiation with melting of the surface layer and irradiation with power density similar to 10 7 W/cm2 below the melting threshold. Structure and phase changes as well as the mechanisms of modification and hardening of the surface layers of the steel and titanium alloy upon applied irradiation are discussed.
    Źródło:
    Nukleonika; 2012, 57, 2; 291-295
    0029-5922
    1508-5791
    Pojawia się w:
    Nukleonika
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Changes in phosphorylation of histone H2A.X and p53 in response of peripheral blood lymphocytes to gamma irradiation
    Autorzy:
    Vilasová, Zdeňka
    Řezáčová, Martina
    Vávrová, Jiřina
    Tichý, Aleš
    Vokurková, Doris
    Zoelzer, Friedo
    Řeháková, Zuzana
    Osterreicher, Jan
    Lukášová, Emilie
    Powiązania:
    https://bibliotekanauki.pl/articles/1040760.pdf
    Data publikacji:
    2008
    Wydawca:
    Polskie Towarzystwo Biochemiczne
    Tematy:
    lymphocyte
    ionizing radiation
    p53
    phytohemagglutinin (PHA)
    apoptosis
    DNA damage
    Opis:
    The main aim of this study was to compare the reaction of quiescent and proliferating, i.e. phytohemagglutinin (PHA)-stimulated, human peripheral blood mononuclear cells (PBMCs) to γ-radiation, and analyse changes of proteins related to repair of DNA damage and apoptosis, such as γH2A.X, p53, p53 phosphorylation at serines-15 and -392, and p21 and their dose dependence. Freshly isolated PBMCs in peripheral blood are predominantly quiescent, in G0 phase, and with very low amounts of proteins p53 and p21. Using confocal microscopy we detected dose dependent (0.5-5 Gy) induction of foci containing γH2A.X (1 h after γ-ray exposure), which are formed around radiation-induced double strand breaks of DNA. Apoptosis was detected from 24 h after irradiation by the dose of 4 Gy onwards by Annexin V binding and lamin B cleavage. Seventy two hours after irradiation 70% of CD3+ lymphocytes were A+. Neither increase in p53 nor its phosphorylation on serine-392 after irradiation was detected in these cells. However, massive increase in p21 (cyclin-dependent kinase inhibitor 1A) was detected after irradiation, which can be responsible for late occurrence of apoptosis in these quiescent cells. PHA-stimulation itself (72 h) caused an increase in early apoptosis (A+PI-) in comparison to non-stimulated PBMCs (38% A+ resp. 13.4%). After PHA-stimulation also the amount of γH2A.X, p53, and p21 increased, but no phosphorylation of p53 on serine-392 or -15 was detected. Reaction to γ-radiation was different in PHA-stimulated lymphocytes: the p53 pathway was activated and p53 was phosphorylated on serines-15 and -392 4 h after irradiation by the dose of 4 Gy. Phosphorylation of p53 at serine-15 increased in a dose-dependent manner in the studied dose range 0.2-7.5 Gy. Also the amount of p21 increased after irradiation. Seventy two hours after irradiation of PHA-stimulated CD3+ T lymphocytes by the dose of 4 Gy 65% of cells were A+.
    Źródło:
    Acta Biochimica Polonica; 2008, 55, 2; 381-390
    0001-527X
    Pojawia się w:
    Acta Biochimica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Evaluation of circulating microparticles in healthy medical workers occupationally exposed to ionizing radiation: A preliminary study
    Autorzy:
    Al-Massarani, Ghassan
    Najjar, Fadi
    Aljapawe, Abdulmunim
    Ikhtiar, Adnan
    Powiązania:
    https://bibliotekanauki.pl/articles/2162036.pdf
    Data publikacji:
    2018-12-20
    Wydawca:
    Instytut Medycyny Pracy im. prof. dra Jerzego Nofera w Łodzi
    Tematy:
    biomarkers
    flow cytometry
    occupational exposure
    microparticles
    ionizing radiation
    cellular damage
    Opis:
    Objectives Ionizing radiation was known to cause disruption of cytoskeleton. However, the disorganization of the cytoskeleton leads to form microparticles (MP) that carry membrane and cytoplasmic constituents from their parent cells they are released from. Therefore, authors investigated the effect of the occupational exposure to low doses of ionizing radiation on MP levels. Material and Methods The current study was conducted on 38 healthy medical workers occupationally exposed to low doses of ionizing radiation and 29 controls matched by gender, age, and smoking habits. The MP levels measured by flow cytometry were classified as positive or negative phosphatidylserine (PS⁺ or PS⁻), and phenotyped according to their cellular origin. Results Total MP (PS–/PS+) levels, regardless of phenotype, were significantly higher in workers occupationally exposed to ionizing radiation than in healthy individuals (p = 0.0004). Negative phosphatidylserine microparticles were predominant in medical exposed workers and, to a lesser extent, in controls (68% and 57%, respectively). With regard to phenotypic characterization of cellular origin, MP derived from platelets (CD41a+), endothelial (CD146+), leucocytes (CD45+) and erythrocytes (CD235a+) MP were significantly enhanced in exposed workers compared with controls (p < 0.0001). However, no significant difference was found in the proportion of the other blood elements in the peripheral circulation between the 2 groups. Serum levels of C-reactive protein were normal for all individuals. In addition, no association was observed between MP levels and the studied confounding factors. Conclusions The results suggest that elevated circulating MP levels represent an indicator of cellular damage caused by medical exposure to low doses of ionizing radiation. By consequence, the quantification of MP seems to be a useful biomarker for assessing the negative effects of occupational exposure to ionizing radiation. Int J Occup Med Environ Health 2018;31(6):783–793
    Źródło:
    International Journal of Occupational Medicine and Environmental Health; 2018, 31, 6; 783-793
    1232-1087
    1896-494X
    Pojawia się w:
    International Journal of Occupational Medicine and Environmental Health
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Comparison of the effects of bleomycin and ionizing radiation in two sublines of murine lymphoma L5178Y
    Autorzy:
    Kruszewski, M.
    Zaim, J.
    Grądzka, I.
    Szumiel, I.
    Powiązania:
    https://bibliotekanauki.pl/articles/147561.pdf
    Data publikacji:
    2001
    Wydawca:
    Instytut Chemii i Techniki Jądrowej
    Tematy:
    bleomycin
    comet assay
    DNA damage
    gamma radiation
    single cell gel electrophoresis
    Opis:
    We compared the effects of bleomycin (BLM) and ionizing radiation on two sublines of murine lymphoma L5178Y (LY): LY-R, radiation resistant and LY-S, radiation sensitive. This radiosensitivity difference is related to the ability to rejoin DNA double strand breaks. LY-S cells were about two times more sensitive to BLM than LY-R, similarly as in the case of sensitivity to X rays. Since there was no difference in the P-glycoprotein-related drug transport system between the sublines, it could be expected that the enhanced sensitivity of LY-S cells to BLM was caused by the DNA repair defect. Growth disturbances in BLM treated cell populations were proportional to the lethal effect and their duration was observed until elimination of dead cells (3-6 days after 50 ěM BLM, 1 h at 37oC). There was no slow growth phase accompanied by normal viability, as previously described for X-irradiated LY-S cells. Initial DNA damage, estimated with the single cell gel electrophoresis method was linearly related to BLM dose in LY-S cells; in LY-R cells - in the low dose range (up to 10 ěM) - there was more damage than in LY-S cells, however, at higher doses the dose - effect curves became identical. The doseeffect relationship for ă rays was linear and identical in both cell sublines. DNA damage distribution in BLM treated cells was much less uniform as compared to that in irradiated cells and indicated the presence of cells with severely damaged DNA, a feature typical for BLM action in vitro.
    Źródło:
    Nukleonika; 2001, 46, 3; 81-86
    0029-5922
    1508-5791
    Pojawia się w:
    Nukleonika
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Określenie zależności pomiędzy odpornością bulwy ziemniaka na uszkodzenia mechaniczne a wielkością dawki promieniowania mikrofalowego
    Determination of relation between potato tuber resistance to mechanical damage and size of microwave radiation dose
    Autorzy:
    Marks, N.
    Jakubowski, T.
    Powiązania:
    https://bibliotekanauki.pl/articles/290311.pdf
    Data publikacji:
    2008
    Wydawca:
    Polskie Towarzystwo Inżynierii Rolniczej
    Tematy:
    promieniowanie mikrofalowe
    ziemniak
    bulwa
    uszkodzenie mechaniczne
    microwave radiation
    potato
    tuber
    mechanical damage
    Opis:
    W pracy poszukiwano zależności pomiędzy dawką promieniowania mikrofalowego a odpornością bulwy ziemniaka na uszkodzenia mechaniczne mierzone siłą przebicia perydermy na granicy wytrzymałości biologicznej. Do badań przyjęto odmianę ziemniaka Felka. Bulwy poddane stymulacji mikrofalowej oraz bulwy stanowiące próbę kontrolną obciążano przy użyciu penetrometru statyczno-sprężynowego. Wyniki doświadczenia miały określić wartość dawki promieniowania mikrofalowego powodującego obniżenie odporności bulwy ziemniaka na uszkodzenia mechaniczne. Analiza statystyczna wykazała istotne różnice pomiędzy próbą kontrolną a próbami poddanymi działaniu promieniowania mikrofalowego w zakresie przyjętych do badań czasów ekspozycji i dawek promieniowania. Badania potwierdziły wpływ promieniowania mikrofalowego na odporność bulw ziemniaka przy obciążeniu statycznym. Określono wartość progową jednostkowej dawki promieniowania mikrofalowego powodującego obniżenie odporności bulwy ziemniaka na uszkodzenia mechaniczne.
    The purpose of the work was to find relation between microwave radiation dose and potato tuber resistance to mechanical damage measured by periderm puncture force at the boundary of biological resistance. The Felka variety potato was used in the tests. Tubers subject to microwave stimulation and tubers constituting control sample were loaded using a static-spring penetrometer. Experiment results were expected to determine the amount of microwave radiation dose reducing potato tuber resistance to mechanical damage. Statistic analysis proved significant differences between control sample and samples exposed to microwave radiation within range of exposure times and radiation doses accepted for the test. The tests confirmed microwave radiation impact on potato tuber resistance at static load. The research allowed to determine threshold value of unit dose of microwave radiation, which reduces potato tuber resistance to mechanical damage.
    Źródło:
    Inżynieria Rolnicza; 2008, R. 12, nr 1(99), 1(99); 283-289
    1429-7264
    Pojawia się w:
    Inżynieria Rolnicza
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Dark current behaviour of type-II superlattice longwave infrared photodetectors under proton irradiation
    Autorzy:
    Bataillon, Clara
    Perez, Jean-Phillipe
    Alchaar, Rodolphe
    Michez, Alain
    Gilard, Olivier
    Saint-Pé, Olivier
    Christol, Philippe
    Powiązania:
    https://bibliotekanauki.pl/articles/2204227.pdf
    Data publikacji:
    2023
    Wydawca:
    Polska Akademia Nauk. Stowarzyszenie Elektryków Polskich
    Tematy:
    displacement damage dose
    proton radiation
    total ionizing dose
    type-II superlattice photodetector
    Opis:
    In this work, the authors investigated the influence of proton-irradiation on the dark current of XBp longwave infrared InAs/GaSb type-II superlattice barrier detectors, showing a cutoff wavelength from 11 μm to 13 μm at 80 K. The proton irradiations were performed with 63 MeV protons and fluences up to 8∙10¹¹ H+/cm² on a type-II superlattice detector kept at cryogenic (100 K) or room temperature (300 K). The irradiation temperature of the detector is a key parameter influencing the effects of proton irradiation. The dark current density increases due to displacement damage dose effects and this increase is more important when the detector is proton-irradiated at room temperature rather than at cryogenic temperature.
    Źródło:
    Opto-Electronics Review; 2023, 31, Special Issue; art. no. e144552
    1230-3402
    Pojawia się w:
    Opto-Electronics Review
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    5',8-Cyclo-2'-deoxyadenosine (cdA) formation by γ-radiation. Theoretical quantum mechanics study
    Autorzy:
    Karwowski, Boleslaw
    Grand, Andre
    Cadet, Jean
    Powiązania:
    https://bibliotekanauki.pl/articles/1040482.pdf
    Data publikacji:
    2009
    Wydawca:
    Polskie Towarzystwo Biochemiczne
    Tematy:
    5',8-cyclo-2'-deoxyadenosine
    DNA damage
    ionizing radiation
    density functional theory (DFT)
    Opis:
    Reactions of reactive oxygen species and more specifically - of hydroxyl radical (•OH) - with nucleosides may lead to the generation of radicals in the base and 2-deoxyribose moieties. In the present study emphasis was put on the possible reaction modes of 2'-deoxyadenosine (dA) radicals, leading to the formation of related 5',8-cyclonucleosides. It appears that the prerequisite for the formation of 5',8-cyclo-2'-deoxyadenosine (cdA) is the adoption of O4'-exo conformation by 2-deoxyribose; however, this is the least energetically favored conformer among the different puckered forms adopted by the furanose ring. The O4'-exo conformation was found to be present in each of the discussed mechanisms.
    Źródło:
    Acta Biochimica Polonica; 2009, 56, 4; 655-662
    0001-527X
    Pojawia się w:
    Acta Biochimica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    DNA damage and repair in lymphocytes of normal individuals and cancer patients: studies by the comet assay and micronucleus tests.
    Autorzy:
    Palyvoda, Olena
    Polańska, Joanna
    Wygoda, Andrzej
    Rzeszowska-Wolny, Joanna
    Powiązania:
    https://bibliotekanauki.pl/articles/1043662.pdf
    Data publikacji:
    2003
    Wydawca:
    Polskie Towarzystwo Biochemiczne
    Tematy:
    ionizing radiation
    DNA damage
    human lymphocytes
    comet assay
    head and neck tumors
    DNA repair
    Opis:
    A population study is reported in which the DNA damage induced by γ-radiation (2 Gy) and the kinetics of the subsequent repair were estimated by the comet and micronucleus assays in isolated lymphocytes of 82 healthy donors and patients with head and neck cancer before radiotherapy. The parameters of background and radiation-induced DNA damage, rate of repair, and residual non-repaired damage were measured by comet assay, and the repair kinetics for every donor were computer-fitted to an exponential curve. The level of background DNA damage before irradiation measured by comet assay as well as the level of micronuclei were significantly higher in the head and neck cancer patient group than in the healthy donors, while the parameters of repair were widely scattered in both groups. Cancer patient group contained significantly more individuals, whose irradiated lymphocytes showed high DNA damage, low repair rate and high non-repaired DNA damage level. Lymphocytes of donors belonging to this subgroup showed significantly lower inhibition of cell cycle after irradiation.
    Źródło:
    Acta Biochimica Polonica; 2003, 50, 1; 181-190
    0001-527X
    Pojawia się w:
    Acta Biochimica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Repair of γ-ray-induced base damage in L5178Y sublines is damage type-dependent and unrelated to radiation sensitivity.
    Autorzy:
    Kruszewski, Marcin
    Zastawny, Tomasz
    Szumiel, Irena
    Powiązania:
    https://bibliotekanauki.pl/articles/1044148.pdf
    Data publikacji:
    2001
    Wydawca:
    Polskie Towarzystwo Biochemiczne
    Tematy:
    radiation sensitivity
    : γ-rays
    DNA base damage repair
    L5178Y murine lymphoma sublines
    Opis:
    The L5178Y (LY) murine lymphoma sublines LY-R and LY-S are differentially sensitive to ionizing radiation. The high radiation sensitivity of LY-S cells is related to impaired rejoining of DNA double strand breaks. We found previously that the γ-ray-induced base damage is higher in the more radiosensitive LY-S subline. Here, we examine the role of the repair of ionizing radiation induced base damage in relation to the radiosensitivity difference of these sublines. We used the GS/MS technique to estimate the repair rates of six types of base damage in γ-irradiated LY cells. All modified DNA bases identified in the course of this study were typical for irradiated chromatin. The total amount of initial base damage was higher in the radiation sensitive LY-S subline than in the radiation resistant LY-R subline. The repair rates of 5-OHMeUra, 5-OHCyt, 8-OHAde were similar in both cell lines, the repair rates of FapyAde and 8-OHGua were higher in the radiosensitive LY-S cell line, whereas the repair of 5-OHUra was faster in its radioresistant counterpart, the LY-R Altogether, the repair rates of the γ-ray-induced DNA base damage in LY sublines are related neither to the initial amounts of the damaged bases nor to the differential lethal or mutagenic effects of ionizing radiation in these sublines.
    Źródło:
    Acta Biochimica Polonica; 2001, 48, 2; 525-533
    0001-527X
    Pojawia się w:
    Acta Biochimica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Characterization of dense plasma streams generated by MPC and their interaction with material surfaces
    Autorzy:
    Makhlaj, V. A.
    Chebotarev, V. V.
    Chuvilo, A. A.
    Garkusha, I. E.
    Ladygina, M. S.
    Marchenko, A. K.
    Petrov, Y. V.
    Solyakov, D. G.
    Powiązania:
    https://bibliotekanauki.pl/articles/147528.pdf
    Data publikacji:
    2012
    Wydawca:
    Instytut Chemii i Techniki Jądrowej
    Tematy:
    magneto-plasma compressor (MPC)
    gas-discharge plasma
    plasma streams
    mixture gas
    EUV radiation
    surface damage
    Opis:
    Comparative studies of the parameters both pure helium and helium-xenon plasma have been fulfilled in a magneto-plasma compressor (MPC). The current-voltage characteristics of MPC accelerating channel and the maximum plasma velocity of (6-8) x 106 cm/s changed negligibly under local xenon injection to compression zone. Nevertheless, the xenon addition causes a growth of maximal plasma pressure up to of 2.3 MPa, an increase of plasma radiation from the compression zone. The plasma density achieved 1018 cm.
    Źródło:
    Nukleonika; 2012, 57, 2; 197-200
    0029-5922
    1508-5791
    Pojawia się w:
    Nukleonika
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    DNA damage in subpopulations of human lymphocytes irradiated with doses in the range of 0-1 Gy of X-radiation
    Autorzy:
    Wojewódzka, M.
    Machaj, E. K.
    Goździk, A.
    Iwaneńko, T.
    Ołdak, T.
    Kruszewski, M.
    Pojda, Z.
    Powiązania:
    https://bibliotekanauki.pl/articles/147760.pdf
    Data publikacji:
    2008
    Wydawca:
    Instytut Chemii i Techniki Jądrowej
    Tematy:
    alkaline comet assay
    biodosimetry
    micronucleus test
    histone gammaH2AX foci immunofluorescence assay
    T lymphocytes
    B lymphocytes
    ionizing radiation
    DNA damage
    Opis:
    We compared three methods usually applied in biological dosimetry for estimation of radiation-induced DNA damage in human T and B lymphocytes: alkaline comet assay, micronucleus (MN) test and formation of histone gamma-H2AX foci. Human peripheral blood lymphocytes were fractionated using T cells and B cells isolation kits. Cells were irradiated with doses in the range of 0-1 Gy of X-rays. Induction of DNA damage was assessed by the standard alkaline comet assay, MN test and histone gammaH2AX foci immunofluorescence assay. Notwithstanding different end-points measured by the applied methods, all tests revealed a similar induction of DNA damage in B lymphocytes as compared with T lymphocytes. The results indicated that all three tests detect DNA damage with similar sensitivity, the lowest dose being approximately 0.3 Gy. The difference between irradiated and control cells was expressed as the ratio of the value obtained for irradiated cells (1 Gy) to that for control cells. The highest ratio was obtained for formation of gammaH2AX foci and was 6.2 for T and 13.8 for B lymphocytes, whereas those for comet assay and micronucleus test were 3.5; 3.6 and 5.6; 4.8, respectively.
    Źródło:
    Nukleonika; 2008, 53, 4; 145-149
    0029-5922
    1508-5791
    Pojawia się w:
    Nukleonika
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Wpływ słonecznego promieniowania ultrafioletowego (UV) na powstawanie raków skóry
    The effect of solar ultraviolet radiation (UVR) on induction of skin cancers
    Autorzy:
    Pacholczyk, Marta
    Czernicki, Jan
    Ferenc, Tomasz
    Powiązania:
    https://bibliotekanauki.pl/articles/2164405.pdf
    Data publikacji:
    2016-04-25
    Wydawca:
    Instytut Medycyny Pracy im. prof. dra Jerzego Nofera w Łodzi
    Tematy:
    rak podstawnokomórkowy
    promieniowanie UV
    czerniak
    rak płaskonabłonkowy
    uszkodzenia DNA
    melanina
    Basal cell carcinoma
    UV radiation
    melanoma
    squamous cell carcinoma
    DNA damage
    melanin
    Opis:
    Promieniowanie ultrafioletowe (UV) jest fizycznym czynnikiem mutagennym i karcynogennym. Do powierzchni Ziemi dociera ok. 95% promieniowania ultrafioletowego A (UVA) (320–400 nm) i ok. 5% UVB (280–320 nm). Naturalnym czynnikiem ochronnym skóry przed UV jest melanina. Do raków skóry, których rozwój jest związany z długotrwałym narażeniem na promieniowanie UV, zalicza się niebarwnikowe raki skóry (non-melanoma skin cancers – NMSC) – raka podstawnokomórkowego (basal cell carcinoma – BCC) i raka kolczystokomórkowego (squamous cell carcinoma – SCC) oraz czerniaka złośliwego skóry (cutaneous malignant melanoma – CMM). Wysokie ryzyko rozwoju BCC związane jest z ostrą i wielokrotną ekspozycją na UV, powodującą oparzenia słoneczne. Badania molekularne BCC wykazały zaburzenia na szlaku regulacji sygnalizacji komórkowej sonic hedgehog (SHH), które były związane z mutacjami genu supresorowego PTCH1 (protein patched homolog 1). Ryzyko rozwoju BCC jest również związane z polimorfizmem genu receptora melanokortyny-1 (MC1R). Obserwowane w komórkach BCC mutacje genu P53 klasyfikowano jako wtórne zmiany genetyczne. W komórkach SCC mutacje indukowane UV najczęściej dotyczyły genu P53. W rozwoju SCC istotne znaczenie ma zwiększona ekspresja genu enzymu cyklooksygenazy-2 (COX-2). Innym czynnikiem patogenetycznym SCC jest nasilenie syntezy cytokin prozapalnych (czynnika martwicy nowotworu α (tumor necrosis factor α – TNF-α), interleukiny-1 α (IL-1α), IL-1β i IL-6). Obecnie w patogenezie CMM powszechnie uznawana jest rola UVB. W komórkach CMM notowano mutacje w genach: p16 INK4A (cyclin-dependent kinase inhibitor 2A INK4A), genie kodującym cyklinozależną kinazę 4 (cyclin-dependent kinase 4 – CDK4), Ras, PTEN (phosphatase and tensin homolog deleted on chromosome 10) i BRAF (proto-oncogene B-Raf). Mutacje genu BRAF stwierdzano w ok. 50% przypadków CMM. Mutacje genu P53 nie są charakterystyczne dla komórek CMM. Med. Pr. 2016;67(2):255–266
    Ultraviolet radiation is a physical mutagenic and cancerogenic factor. About 95% of ultraviolet A (UVA) (320–400 nm) and 5% of UVB (280–320 nm) reach the Earth’s surface. Melanin is a natural skin protective factor against UV radiation. Skin cancers associated with long-term exposure to UV radiation are: basal cell carcinoma (BCC), squamous cell carcinoma (SCC) and cutaneous malignant melanoma (CMM). The high risk of BCC development is related to acute and repeated exposure to UV causing sunburn. Molecular studies of BBC demonstrated disorders in sonic hedgehog (SHH) cell signaling regulation pathway, associated with the suppressor protein patched homolog 1 gene (PTCH1) mutations. The risk of the BCC development is related to the polymorphism of melanokortin-1 receptor gene (MC1R). Tumor P53 gene mutations observed in BCC cells has been classified as secondary genetic changes. In SCC cells UV-induced mutations were mostly related to P53 gene. Increased expression of cyclooxigenase- 2 gene (COX-2) plays a significant role in the development of SCC. Other pathogenetic factors include intensification of the synthesis of pro-inflammatory cytokines (tumor necrosis factor α (TNF-α), interleukin-1 α (IL-1α), IL-1β and IL-6). Currently, the role of UVB has been recognized in the pathogenesis of CMM. In CMM cells the following gene mutations were noted: cyclindependent kinase inhibitor 2A INK4A (p16 INK4A), cyclin-dependent kinase 4 (CDK4), Ras, phosphatase and tensin homolog deleted on chromosome 10 (PTEN) and proto-oncogene B-Raf (BRAF). The BRAF gene mutations were observed in ~50% of CMM cases. Mutations of P53 gene are not characteristic of CMM cells. Med Pr 2016;67(2):255–266
    Źródło:
    Medycyna Pracy; 2016, 67, 2; 255-266
    0465-5893
    2353-1339
    Pojawia się w:
    Medycyna Pracy
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
      Wyświetlanie 1-13 z 13

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