The management of skin reactions during epidermal growth factor receptor inhibitors in patients with colorectal cancer

Receptor nabłonkowego czynnika wzrostu (EGFR) jest śródbłonową glikoproteiną wykazującą ekspresję w wielu komórkach pochodzenia nabłonkowego. Stosowanie inhibitorów EGFR wiąże się z występowaniem różnorodnych działań niepożądanych, w tym najczęstszych z nich, reakcji skórnych (tzw. toksyczności skórnej), pojawiających się u ponad połowy leczonych pacjentów — nasilenie jest często powodem redukcji dawki leku bądź nawet przerwania leczenia. Ze względu na istniejący związek między odpowiedzią na leczenie inhibitorami EGFR, wyrażoną przeżyciem wolnym od progresji lub całkowitym przeżyciem a reakcjami skórnymi, obecnie zaleca się raczej leczenie i łagodzenie reakcji skórnych niż redukcję dawek czy przerywanie terapii inhibitorami EGFR. Istnieją jedynie nieliczne dane pochodzące z badań klinicznych, stąd potrzeba zebrania i usystematyzowania informacji dotyczących praktycznego postępowania w przypadku wystąpienia skórnych działań niepożądanych. Zawarte w pracy informacje mogą być przydatne w codziennej praktyce klinicznej i ułatwić podejmowanie decyzji dotyczących zarówno zapobiegania, leczenia i łagodzenia zmian skórnych, jak i samego leczenia inhibitorami EGFR. Skuteczne leczenie objawów skórnych zapewnia odpowiednie dawkowanie leku oraz jakość życia chorego. Onkol. Prak. Klin. 2010; 6, 6: 318–332The epidermal growth factor receptor (EGFR) is a transmembrane glycoprotein expressed by a number of cell types of epithelial origin. The use of EGFR inhibitors is associated with various adverse effects, including the most common ones: skin reactions (the so-called skin toxicity) developing in over half of the treated patients. Their intensification is often the reason for drug dose reduction or even treatment discontinuance. In view of the existing relationship between the response to treatment with EGFR inhibitors, expressed as progression-free survival or overall survival, and the skin reactions, it is currently recommended to opt for managing and alleviating the skin reactions rather than for reducing the drug dose or discontinuing the therapy with EGFR inhibitors. There is available only a limited amount of data from clinical trials on this issue, hence the need to collate and systematise the information concerning the practical approach to adverse effects involving skin. The data contained in this publication may prove useful in everyday clinical practice and facilitate the decision-making as regards the prevention, treatment and alleviation of skin lesions, as well as the therapeutic approach with the use of EGFR inhibitors itself. An effective treatment of skin symptoms ensures appropriate drug dosage and adequate quality of life of the patient. Onkol. Prak. Klin. 2010; 6, 6: 318–33

Disorder suppression and precise conductance quantization in constrictions of PbTe quantum wells

Conductance quantization was measured in submicron constrictions of PbTe, patterned into narrow,12 nm wide quantum wells deposited between Pb$_{0.92}$Eu$_{0.08}$Te barriers. Because the quantum confinement imposed by the barriers is much stronger than the lateral one, the one-dimensional electron energy level structure is very similar to that usually met in constrictions of AlGaAs/GaAs heterostructures. However, in contrast to any other system studied so far, we observe precise conductance quantization in $2e^2/h$ units, {\it despite of significant amount of charged defects in the vicinity of the constriction}. We show that such extraordinary results is a consequence of the paraelectric properties of PbTe, namely, the suppression of long-range tails of the Coulomb potentials due to the huge dielectric constant.Comment: 7 pages, 6 figures, submitted to Phys. Rev.

Ising Quantum Hall Ferromagnet in Magnetically Doped Quantum Wells

We report on the observation of the Ising quantum Hall ferromagnet with Curie temperature $T_C$ as high as 2 K in a modulation-doped (Cd,Mn)Te heterostructure. In this system field-induced crossing of Landau levels occurs due to the giant spin-splitting effect. Magnetoresistance data, collected over a wide range of temperatures, magnetic fields, tilt angles, and electron densities, are discussed taking into account both Coulomb electron-electron interactions and s$-$d coupling to Mn spin fluctuations. The critical behavior of the resistance ``spikes'' at $T \to T_C$ corroborates theoretical suggestions that the ferromagnet is destroyed by domain excitations.Comment: revised, 4 pages, 4 figure

Searches for discrete symmetries violation in ortho-positronium decay using the J-PET detector

In this paper we present prospects for using the J-PET detector to search for discrete symmetries violations in a purely leptonic system of the positronium atom. We discuss tests of CP and CPT symmetries by means of ortho-positronium decays into three photons. No zero expectation values for chosen correlations between ortho-positronium spin and momentum vectors of photons would imply the existence of physics phenomena beyond the Standard Model. Previous measurements resulted in violation amplitude parameters for CP and CPT symmetries consistent with zero, with an uncertainty of about 10-3. The J-PET detector allows to determine those values with better precision thanks to a unique time and angular esolution combined with a high geometrical acceptance. Achieving the aforementioned is possible due to application of polymer scintillators instead of crystals as detectors of annihilation quanta.Comment: in Nukleonika 201

Studies of unicellular micro-organisms Saccharomyces cerevisiae by means of Positron Annihilation Lifetime Spectroscopy

Results of Positron Annihilation Lifetime Spectroscopy (PALS) and microscopic studies on simple microorganisms: brewing yeasts are presented. Lifetime of ortho - positronium (o-Ps) were found to change from 2.4 to 2.9 ns (longer lived component) for lyophilised and aqueous yeasts, respectively. Also hygroscopicity of yeasts in time was examined, allowing to check how water - the main component of the cell - affects PALS parameters, thus lifetime of o-Ps were found to change from 1.2 to 1.4 ns (shorter lived component) for the dried yeasts. The time sufficient to hydrate the cells was found below 10 hours. In the presence of liquid water an indication of reorganization of yeast in the molecular scale was observed. Microscopic images of the lyophilised, dried and wet yeasts with best possible resolution were obtained using Inverted Microscopy (IM) and Environmental Scanning Electron Microscopy (ESEM) methods. As a result visible changes to the surface of the cell membrane were observed in ESEM images.Comment: Nukleonika (2015