343. Ocena występowania kserostomii u chorych leczonych teleradioterapią z powodu nowotworów głowy i szyi z uwzględnieniem wartości hemoglobiny

CelOcena występowania i nasilenia późnego odczynu popromiennego w obrębie ślinianek, z wykorzystaniem skali LENT-SOMA.Metodyka i materiałGrupę badawczą stanowiło 79 chorych leczonych teleradioterapią, z powodu raka głowy i szyi. Średnia wieku wyniosła 55 lat (SD = 8). 89,7% nowotworów stanowił rak płaskonabłonkowy, 6,4% – rak gruczołowy, 2,6% – acinocarcinoma, 1,3% – rak drobnokomórkowy o pierwotnie innym umiejscowieniu. Średnia dawka na obszar napromieniany wyniosła 62 Gy (SD = 10). Średnia dawka na obszar ślinianek wyniosła 57 Gy (SD = 11). Średni czas obserwacji wyniósł 41 miesięcy. Średni czas do wystąpienia pełnoobjawowej kserostomii wyniósł 8 miesięcy. 9 chorych wymagało stałego leczenia substytucyjnego i farmakologicznego kserostomii. 14 chorych wymagało wyłącznie substytucji śliny. Do oceny późnego odczynu popromiennego użyto skali LENT-SOMA, oceniając obiektywne i subiektywne objawy w czasie 6 do 12 miesięcy od zakończenia leczenia. Do określenia wartości statystycznych użyto testu t dla zmiennych niepowiązanych i testu Wilcoxona.WynikiWykazano wystąpienie późnego odczynu popromiennego w skali LENT-SOMA, w obrębie ślinianek przy dawce podanej na ślinianki o wartości 60 Gy i więcej (p = 0,05). Nasilenie odczynu było częstsze i wyższe u chorych napromienianych dawką frakcyjną 2 Gy (p = 0,009; p = 0,0001). niż u pacientów napromienianych dawką frakcyjną 1,8 G. Stopień nasilenia odczynu w skali LENT-SOMA w stosunku do wysokości podanej dawki nie wykazywał znamienności statystycznej. Wykazano znamienność statystyczną pomiędzy poziomem hemoglobiny a wystąpieniem późnego odczynu popromiennego w obrębie ślinianek (p=0,05). Wartość odciętą stanowił poziom hemoglobiny 13,9 g/dl.WnioskiWystąpienie późnego odczynu popromiennego ślinianek, po napromienianiu nowotworów głowy i szyi, jest zależne od dawki frakcyjnej oraz dawki całkowitej promieniowania podanej w obrębie ślinianek. Występowanie późnego odczynu popromiennego po teleradioterapii jest zależne od poziomu hemoglobiny w osoczu

Restoration and preservation of the reinforced concrete poles of fence at the former Auschwitz concentration and extermination camp

AbstractThe objective of this study was to assess the present state of the reinforced concrete poles of fence at the former Auschwitz I and Auschwitz II-Birkenau concentration and extermination camp. The poles were subjected to renovation about 10 years ago. After this time some deficiencies of applied renovation method were noticed. Cracks appeared between fresh and original part of concrete cover. Analysis of the reasons of these failures was performed and a modification of used restoration method was proposed to overcome this deficiency. The modification consists in application of sacrificial anodes mounted outside the pole, in soil and inside the concrete cover

Do protons and X-rays induce cell-killing in human peripheral blood lymphocytes by different mechanisms?

Purpose: Significant progress has been made in the technological and physical aspects of dose delivery and distribution in proton therapy. However, mode of cell killing induced by protons is less understood in comparison with X-rays. The purpose of this study is to see if there is any difference in the mode of cell-killing, induced by protons and X-rays in an ex vivo human peripheral blood lymphocyte (HPBL) model. Materials and methods: HPBL were irradiated with 60 MeV proton beam or 250-kVp X-rays in the dose range of 0.3–4.0 Gy. Frequency of apoptotic and necrotic cells was determined by the Fluorescein (FITC)-Annexin V labelling procedure, 1 and 4 h after irradiation. Chip-based DNA Ladder Assay was used to confirm radiation-induced apoptosis and necrosis. Chip-based DNA Ladder Assay was used to confirm radiation-induced apoptosis. Results: Ex vivo irradiation of HPBL with proton beams of 60 MeV or 250 kVp X-rays resulted in apoptotic as well as necrotic modes of cell-killing, which were evident at both 1 and 4 h after irradiation in the whole dose and time range. Generally, our results indicated that protons cause relatively higher yields of cell death that appears to be necrosis compared to X-rays. The analysis also demonstrates that radiation type and dose play a critical role in mode of cell-killing. Conclusion: Obtained results suggest that X-rays and protons induce cell-killing by different modes. Such differences in cell-killing modes may have implications on the potential of a given therapeutic modality to cause immune modulation via programmed cell death (X-rays) or necrotic cell death (proton therapy). These studies point towards exploring for gene expression biomarkers related necrosis or apoptosis to predict immune response after proton therapy

Effects of 60 MeV protons and 250 kV X-rays on cell viability

Particle radiotherapy such as the one using proton beams, provides a successful treatment approach in many cancer types. However, the cellular and molecular mechanisms by which proton irradiation induces cell death, particularly in a human peripheral blood lymphocyte model has not been examined in detail. Comparative studies of the biological effects, such as cell death, of particle therapy versus conventional X-rays treatment are of utmost importance. Here, we compared the viability of human peripheral blood lymphocyte following in vitro irradiation with protons (therapeutic 60 MeV proton beam) and photon beam (250 kV, X-rays), by applying separate doses within the range of 0.3-4.0 Gy. Cell viability was assessed 1 and 4 h after irradiation with protons and X-rays by the FITC-Annexin V labelling procedure (Apoptotic & Necrotic & Healthy Cells Quantification Kit, Biotium). Results showed that irradiation with both radiation types reduced the number of viable cells in a dose-dependent manner, as assessed as a function of the duration of post-irradiation time. Protons proved more fatal to the cells treated than X-ray photons. This demonstrates a difference in cell viability after irradiation with protons and photons in a human peripheral blood lymphocyte model

Adherence measurements and corrosion resistance in primer/hot-dip galvanized steel systems

This paper focuses on the adherence during ageing of a primer (made of polyester resins crosslinked with melamine) applied onto hot-dip galvanized (HDG) steel for coil coating application and its influence on corrosion protection. A chromium-free surface treatment, composed of fluorotitanic acid, phosphoric acid, manganese phosphate, and vinylphenol was applied on the HDG steel to obtain high corrosion resistance and high adherence of a polyester and melamine primer. The influence of the manganese phosphate on the corrosion and adherence was investigated. To measure the adherence between the metal and the primer, a three-point flexure test was set up. The adherence was then linked with corrosion resistance during ageing, using electrochemical impedance spectroscopy