Video Rate Confocal Laser Scanning Reflection Microscopy in the Investigation of Normal and Neoplastic Living Cell Dynamics

The introduction of video rate confocal laser scanning microscopes (VRCLSM) used in reflection mode with high magnification, high aperture objective lenses and with further magnification by a zoom facility allowed the first detailed observations of the activity of living cytoplasm and offered a new tool for investigation of the structural transition from the living state to the specimen fixed for electron microscopy (EM). We used a Noran Odyssey VRCLSM in reflection (backscattered) mode. A greater degree of oversampling and more comfortable viewing of the live or taped video image was achieved at zoom factor 5, giving a display monitor field width of 10 μ.m. A series of mesenchyme derived cell lines - from normal cells to sarcoma cells of different malignancy - was used to compare behaviour of the observed intracellular structures and results of fixation. We contrasted the dynamic behaviour of fine features in the cytoplasm of normal and neoplastic living cells and changes induced by various treatments. The tubulomembraneous 3D structure of cytoplasm in living cells is dynamic with motion observable at the new limits of resolution provided by VRCLSM. All organelles appear integrated into one functional compartment supporting the continuous 3D trafficking of small particles (vesicles). This integrated dynamic spatial network (IDSN) was found to be largest in neoplastic cells

Rekontrukcija velikih postoperativnih defekata nakon laringofaringektomije sa stajališta otorinolaringologa

The authors draw attention to controversial opinions of surgical treatment of advanced hypopharyngeal tumours including the possibility to cover large postoperative defects with flaps with a defined vascular pedicle. In the Department of Otorhinolaryngology and Head and Neck Surgery in Brno, 6 patients have been treated this way during recent 5 years. The authors report two cases of patients with hypopharyngeal carcinoma. They emphasize the benefit of cooperation with plastic surgeons and the necessity of individual indication for this way of treatment.Autori skreću pozornost na prijeporna mišljenja s obzirom na kirurško liječenje uznapredovalih tumora hipolarinksa i mogućnost prekrivanja velikih postoperativnih defekata režnjevima s definiranom vaskularnom peteljkom. U Odjelu za otolaringologiju i tumore glave i vrata u Brnu, Republika Češka, u posljednjih je pet godina tako liječeno 6 bolesnika. Autori opisuju dva bolesnika s karcinomom hipofarinska liječenih na taj način. Ističu prednosti suradnje s plastičnim kirurzima te nužnost postavljanja pojedinačne indikacije za primjenu te metode liječenja

Rekontrukcija velikih postoperativnih defekata nakon laringofaringektomije sa stajališta otorinolaringologa

The authors draw attention to controversial opinions of surgical treatment of advanced hypopharyngeal tumours including the possibility to cover large postoperative defects with flaps with a defined vascular pedicle. In the Department of Otorhinolaryngology and Head and Neck Surgery in Brno, 6 patients have been treated this way during recent 5 years. The authors report two cases of patients with hypopharyngeal carcinoma. They emphasize the benefit of cooperation with plastic surgeons and the necessity of individual indication for this way of treatment.Autori skreću pozornost na prijeporna mišljenja s obzirom na kirurško liječenje uznapredovalih tumora hipolarinksa i mogućnost prekrivanja velikih postoperativnih defekata režnjevima s definiranom vaskularnom peteljkom. U Odjelu za otolaringologiju i tumore glave i vrata u Brnu, Republika Češka, u posljednjih je pet godina tako liječeno 6 bolesnika. Autori opisuju dva bolesnika s karcinomom hipofarinska liječenih na taj način. Ističu prednosti suradnje s plastičnim kirurzima te nužnost postavljanja pojedinačne indikacije za primjenu te metode liječenja

Online Algorithms for Multi-Level Aggregation

In the Multi-Level Aggregation Problem (MLAP), requests arrive at the nodes of an edge-weighted tree T, and have to be served eventually. A service is defined as a subtree X of T that contains its root. This subtree X serves all requests that are pending in the nodes of X, and the cost of this service is equal to the total weight of X. Each request also incurs waiting cost between its arrival and service times. The objective is to minimize the total waiting cost of all requests plus the total cost of all service subtrees. MLAP is a generalization of some well-studied optimization problems; for example, for trees of depth 1, MLAP is equivalent to the TCP Acknowledgment Problem, while for trees of depth 2, it is equivalent to the Joint Replenishment Problem. Aggregation problem for trees of arbitrary depth arise in multicasting, sensor networks, communication in organization hierarchies, and in supply-chain management. The instances of MLAP associated with these applications are naturally online, in the sense that aggregation decisions need to be made without information about future requests. Constant-competitive online algorithms are known for MLAP with one or two levels. However, it has been open whether there exist constant competitive online algorithms for trees of depth more than 2. Addressing this open problem, we give the first constant competitive online algorithm for networks of arbitrary (fixed) number of levels. The competitive ratio is O(D^4*2^D), where D is the depth of T. The algorithm works for arbitrary waiting cost functions, including the variant with deadlines. We include several additional results in the paper. We show that a standard lower-bound technique for MLAP, based on so-called Single-Phase instances, cannot give super-constant lower bounds (as a function of the tree depth). This result is established by giving an online algorithm with optimal competitive ratio 4 for such instances on arbitrary trees. We also study the MLAP variant when the tree is a path, for which we give a lower bound of 4 on the competitive ratio, improving the lower bound known for general MLAP. We complement this with a matching upper bound for the deadline setting

Streaming facility location in high dimension via geometric hashing

In Euclidean Uniform Facility Location, the input is a set of clients in Rd and the goal is to place facilities to serve them, so as to minimize the total cost of opening facilities plus connecting the clients. We study the classical setting of dynamic geometric streams, where the clients are presented as a sequence of insertions and deletions of points in the grid{1, . . . ,∆}d, and we focus on the high-dimensional regime, where the algorithm’s space complexity must be polynomial (and certainly not exponential) in d·log ∆.We present a new algorithmic framework, based on importance sampling from the stream, for O(1)-approximation of the optimal cost using only poly(d·log ∆)space. This framework is easy to implement in two passes, one for sampling points and the other for estimating their contribution. Over random-order streams, we can extend this to a one-pass algorithm by using the two halves of the stream separately. Our main result, for arbitrary-order streams, computes O(d1.5)-approximation in one pass by using the new framework but combining the two passes differently. This improves upon previous algorithms that either need space exponential in d or only guarantee O(d·log2∆)-approximation, and therefore our algorithms for high-dimensional streams are the first to avoid the O(log ∆)-factor in approximation that is inherent to the widely-used quadtree decomposition. Our improvement is achieved by employing a geometric hashing scheme that maps points in Rd into buckets of bounded diameter, with the key property that every point set of small-enough diameter is hashed into at most poly(d)distinct buckets. Finally, we complement our results with a proof that everystreaming1.085-approximation algorithm requires space exponential in poly(d·log ∆), even for insertion-only streams

Sequence of phase transformations in metastable ß Zr–12Nb alloy studied in situ by HEXRD and complementary techniques

Phase transformations in a metastable beta Zr–12Nb alloy were investigated by high-energy X-ray diffraction (HEXRD) measured simultaneously with thermal expansion in situ during linear heating from room temperature to 800 °C. Complementary in-situ methods of electrical resistance and differential scanning calorimetry, which were performed using the same heating conditions as in the HEXRD experiment, provided additional information on the transformation sequence occurring in the Zr–12Nb alloy. Two bcc phases with a different lattice parameter, ßZr and ßNb, were observed in the investigated temperature range and identified using the phase diagram of the Zr–Nb system. In the initial solution-treated condition, metastable ßZr phase and athermal ¿ particles are present in the material. At about 300 °C, Nb-rich ßNb phase starts to form in the material and the original ßZr phase gradually disappears. Ex-situ observations of the microstructure using transmission electron microscopy revealed a cuboidal shape of the ¿ particles, which is related to a relatively large misfit between the ¿ and ß phases. At 560 °C, ¿ solvus was observed, identified by an abrupt dissolution of ¿ particles which was followed by growth of the a phase.Peer ReviewedPostprint (published version

Preoperative neoadjuvant chemoradiation for locally advanced gastric adenocarcinoma

Aims and BackgroundTo evaluate toxicity and the radical resection rate in gastric adenocarcinoma treated with preoperative neoadjuvant chemoradiation.Materials & Methods32 patients, 22 males and 10 females with gastric adenocarcinoma, were treated with chemoradiation and hyperthermia.ResultsThe neoadjuvant regimen was completed as planned in 19/32 (59 %) patients; in the remaining patients the intensity of chemotherapy had to be reduced because of haematological and gastrointestinal toxicity. Surgical stage was as follows: 2 patients pathologically complete response, 3 patients AJCC stage I.A, 5 patients stage I.B, 7 patients stage II, 7 patients stage III.A, 1 patient stage III.B, 7 patients stage IV. R0 resection was achieved in 19/32 (59%) patients, R1 in 2/32 (6%) patients and R2 in 11 (34%) patients. Downstaging after neoadjuvant chemoradiotherapy was achieved in 17/32 (53%) patients. At the date of evaluation (31 March 2009), 4 patients were still alive 58, 81, 86 and 98 months from the date of diagnosis. Median survival was 18 months (95% confidence interval: 13–38 months). One-year survival was 69% (95% confidence interval: 53%–85%). Four-year survival was 19% (95% C.I.: 5%–34%).ConclusionsPreoperative neoadjuvant chemoradiotherapy has acceptable toxicity, and can lead to a high rate of R0 resections

Hodnoceni specifickych podminek pro vyzivu ovci pri obnovene pastve v Narodni prirodni rezervaci Mohelenska hadcova step.

Available from STL Prague, CZ / NTK - National Technical LibrarySIGLECZCzech Republi

Fast intracellular motion in the living cell by video rate reflection confocal laser scanning microscopy

Fast intracellular motion (FIM) was first revealed by back scattered light (BSL) imaging in video rate confocal scanning laser microscopy (VRCSLM), beyond the limits of spatial and temporal resolution obtainable with conventional optical microscopy. BSL imaging enabled visualisation of intra and extracellular motion with resolution in space down to 0.2 μm and in time to 1/25th of a second. Mapping the cell space at 0.2 μm×0.2 μm (XY = in instantaneous best focal plane)×0.5 μm (Z = height/depth, optic axis direction) volume steps revealed a communication layer above the known contact layer and an integrated dynamic spatial network (IDSN) towards the cell centre. FIM was originally observed as localised quasichaotic dancing (dithering) or reflecting patches/spots in the cell centre, faster in the darker nuclear space. Later, a second type of FIM was recognised which differed by the presence of a varied proportion of centrifugal and centripetal directional movements and/or jumping of patches/spots in the cell centre and outside the nuclear space. The first type is characteristic for cells in slightly adverse conditions while the second type has so far only been found in eutrophic cells. Temporal speeding up and coarsening of FIM, followed by slowing and eventually cessation at cell death, was found on exposure to strong stressors. It was concluded that the state of FIM provides instantaneous information about individual cell reactions to actual treatment and about cell survival. A putative switch between the first and second type FIM could be considered as an indicator of timing of cellular processes. The significance of FIM for the biology of the cell is seen in the rapid assessment of the condition of an individual live cell investigated by combination of various methods. Requirements for further development of this approach are outlined