763 research outputs found
Selective jejunal manipulation initiates a proinflammatory molecular response within the gastric and colonic muscularis
Przerzut pierwotnego mięsaka serca do mózgu
Primary cardiac sarcomas are exceptionally rare tumours. A brain metastasis of a primary cardiac sarcoma has never been reported before. Although we know lots of primary malignomas spreading to the brain, we never observed cerebral metastases of an atrial spindle cell sarcoma. Cardiac sarcomas are more likely to haematogenously metastasize to the lung or the liver.
Here, we describe the case of a young man, who suffered from a cerebral metastasis of a spindle cell sarcoma in the left heart atrium nine years ago. Postoperative whole brain irradiation with 30 Gy was performed. Later on, the patient experienced a local recurrence within the left atrium accompanied by cardiac arrhythmia and mitral valve insufficiency. This case is the very first description of a true cerebral metastasis from a primary heart sarcoma. Therefore, clear treatment paradigms are not established. Further case illustrations and the publication of larger patient series are mandatory, whenever possible.Pierwotne mięsaki serca są wyjątkowo rzadkimi guzami. Dotychczas nie opisano przerzutu pierwotnego mięsaka serca do mózgu. Chociaż wiadomo wiele o przerzutach pierwotnych nowotworów złośliwych do mózgu, to nigdy wcześniej nie opisano przerzutów mięsaka wrzecionowa-tokomórkowego przedsionka do mózgu. Guzy te z większym prawdopodobieñstwem mogą dawać przerzuty drogą krwi do płuc lub wątroby.
W pracy opisano przypadek młodego mężczyzny, u którego 9 lat wcześniej wystąpił guz przerzutowy mózgu, którego źródłem był mięsak wrzecionowatokomórkowy lewego przedsionka. Po leczeniu chirurgicznym przeprowadzono napromienianie całego mózgowia dawką 30 Gy. W późniejszym czasie u chorego wystąpiła miejscowa wznowa guza lewego przedsionka, której towarzyszyło migotanie przedsionków i niedomykalność zastawki dwudzielnej.
Przedstawiony przypadek jest pierwszym opisem rzeczywistego przerzutu pierwotnego mięsaka serca do mózgu. Nie ma zatem ustalonych zasad postępowania. W miarę możliwości wskazane byłoby publikowanie kolejnych opisów przypadków lub ich serii
Spatio-temporal distribution of nucleation events during crystal growth
We consider irreversible second-layer nucleation that occurs when two adatoms
on a terrace meet. We solve the problem analytically in one dimension for zero
and infinite step-edge barriers, and numerically for any value of the barriers
in one and two dimensions. For large barriers, the spatial distribution of
nucleation events strongly differs from , where is the
stationary adatom density in the presence of a constant flux. The probability
that nucleation occurs at time after the deposition of the second
adatom, decays for short time as a power law [] in and
logarithmically [] in ; for long time it decays
exponentially. Theories of the nucleation rate based on the assumption
that it is proportional to are shown to overestimate by a
factor proportional to the number of times an adatom diffusing on the terrace
visits an already visited lattice site.Comment: 4 pages, 3 figures; accepted for publication on PR
Promoter hypermethylation of SHOX2 and SEPT9 is a potential biomarker for minimally invasive diagnosis in adenocarcinomas of the biliary tract
Clinicopathological data of the 20 biliary tract cancer cases and 100 gender- and age-matched controls included in plasma study. (XLSX 116 kb
Interventions to improve executive functioning and working memory in school-aged children with AD(H)D:A randomised controlled trial and stepped-care approach
Island nucleation in the presence of step edge barriers: Theory and applications
We develop a theory of nucleation on top of two-dimensional islands bordered
by steps with an additional energy barrier for descending atoms.
The theory is based on the concept of the residence time of an adatom on the
island,and yields an expression for the nucleation rate which becomes exact in
the limit of strong step edge barriers. This expression differs qualitatively
and quantitatively from that obtained using the conventional rate equation
approach to nucleation [J. Tersoff et al., Phys. Rev. Lett.72, 266 (1994)]. We
argue that rate equation theory fails because nucleation is dominated by the
rare instances when two atoms are present on the island simultaneously. The
theory is applied to two distinct problems: The onset of second layer
nucleation in submonolayer growth, and the distribution of the sizes of top
terraces of multilayer mounds under conditions of strong step edge barriers.
Application to homoepitaxial growth on Pt(111) yields the estimate eV for the additional energy barrier at CO-decorated steps.Comment: 13 pages, 3 figure
Simulations of energetic beam deposition: from picoseconds to seconds
We present a new method for simulating crystal growth by energetic beam
deposition. The method combines a Kinetic Monte-Carlo simulation for the
thermal surface diffusion with a small scale molecular dynamics simulation of
every single deposition event. We have implemented the method using the
effective medium theory as a model potential for the atomic interactions, and
present simulations for Ag/Ag(111) and Pt/Pt(111) for incoming energies up to
35 eV. The method is capable of following the growth of several monolayers at
realistic growth rates of 1 monolayer per second, correctly accounting for both
energy-induced atomic mobility and thermal surface diffusion. We find that the
energy influences island and step densities and can induce layer-by-layer
growth. We find an optimal energy for layer-by-layer growth (25 eV for Ag),
which correlates with where the net impact-induced downward interlayer
transport is at a maximum. A high step density is needed for energy induced
layer-by-layer growth, hence the effect dies away at increased temperatures,
where thermal surface diffusion reduces the step density. As part of the
development of the method, we present molecular dynamics simulations of single
atom-surface collisions on flat parts of the surface and near straight steps,
we identify microscopic mechanisms by which the energy influences the growth,
and we discuss the nature of the energy-induced atomic mobility
Functional interaction between the epidermal growth factor receptor and c-Src kinase activity
AbstractTo study the relationship between the tyrosine kinase c-Src and the epidermal growth factor receptor (EGF-R), we used the breast cancer cell line ZR75-1, which was transfected with the EGF-R. The EGF-R transfected cell line expressed 60 times more EGF-R than a control cell line transfected with the empty vector. In the presence of EGF, the EGF-R over-expressing cell line grew much faster than the control cell line. Both cell lines expressed approximately equal amounts of c-Src. However, the cell line over-expressing the EGF-R showed a twofold enhancement of c-Src kinase activity after EGF stimulation. The activation of c-Src kinase by EGF was confirmed in other EGF-R expressing cell types
Glioblastoma cells express functional cell membrane receptors activated by daily used medical drugs
PURPOSE: Calcium ions are highly versatile spacial and temporal intracellular signals of non-excitable cells and have an important impact on nearly every aspect of cellular life controlling cell growth, metabolism, fluid secretion, information processing, transcription, apoptosis, and motility. Neurons and glia respond to stimuli, including neurotransmitters, neuromodulators, and hormones, which increase the intracellular calcium concentration. The function of intracellular calcium in gliomas is unknown. Lots of daily used drugs may act via receptors that can be linked to the intracellular calcium system and therefore could influence glioma biology. METHODS: Glioma cells were loaded with the calcium ion sensitive dye Fura 2-AM. Subsequently, cells were stimulated with 25 different medical drugs for 30 s. The increase of free intracellular calcium ions was measured and calculated by a microscope–camera–computer-unit. RESULTS: Except for the buffer solution HEPES that served as negative control and for the cortisol derivative dexamethasone, all other 24 tested drugs induced a rise of intracellular calcium ions. The cellular calcium responses were classified into seven functional groups. The tested substances activated several types of calcium channels and receptors. CONCLUSIONS: Our study impressively demonstrates that medical drugs are potent inducers of intracellular calcium signals. Totally unexpected, the results show a high amount of functional cellular receptors and channels on glioma cells, which could be responsible for certain biological effects like migration and cell growth. This calcium imaging study proves the usability of the calcium imaging as a screening system for functional receptors on human glioma cells
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