Імуногістохімічне виявлення судинного епітеліального ростового фактору в корі великих півкуль головного мозку при порушеннях кровообігу

Порушення кровопостачання мозку – одне з актуальних питань сучасної медицини, що обумовлено, як тяжкістю наслідків кожного конкретного випадку хвороби, так і рівнем показників захворюваності, що сягають пандемії, а смертність від цієї патології становить понад 20% і займає друге місце після серцево-судинних захворювань. Сьогодні зміни при ішемії мозку розглядаються як складний багатовекторний процес зі специфічною кінетикою на перебіг якого можна впливати, а не як одноманітну подію, як вважалось ще 20 років тому

Counter-balanced gene regulatory inputs as a cause of RSE.

<p>a) A description of the bi-stable mechanism. (Top) The core topology. The genes are named based on their role in the mechanism. The mechanism involves a “general repressor” which regulates the activity of a bi-stable module. The bi-stable module consists of an auto-activating gene that activates a gene that represses itself. (Bottom) The space time behavior of the core topology with a typical parameter set. The x-dimension represents space and the y-dimension represents the gene product concentration. The color corresponds to the gene in the topology above. T indicates the representative stage of the mechanism. The morphogen feeds into the general repressor that correspondingly forms a similar gradient. The “module activator” starts to be expressed everywhere due to positive auto-regulation. The “module repressor” starts to be expressed on the right hand side due to activation everywhere by the module activator and repression on the left hand side by the general repressor. <i>Middle (T = 2):</i> At the very right hand side, the module repressor reaches a high enough concentration to start to force the activator off. <i>Late (T = 3):</i> The module repressor concentration also starts to drop due to lack of activation from the module activator. <i>Final (T = 4).</i> The result is a stripe of expression of the module repressor gene. b) An example of where counter-balanced gene-gene regulatory inputs cause RSE. The core topology of the Bi-stable mechanism (black gene-gene interactions) is viable/fit (1) along with the core topology with two additional interactions of opposing sign (green gene-gene interactions) that feed into the same gene (4). However either of the individual mutations alone has significantly less average functional neutrality (2 and 3). c) An illustration of the general concept of counter-balanced gene regulatory inputs causing RSE. The inputs must feed into the same gene though the interaction could come from the same gene or another gene.</p

Epistasis and neutral networks.

<p>a) Illustrating reciprocal sign epistasis. When there is no epistasis the combined effects of two mutations are the result of the addition of the fitness effect of each individual mutation. There is reciprocal sign epistasis when the two individual mutations negatively affect fitness yet the double mutant is fitter than the combination of individual mutations. Figure adapted from <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0061178#pone.0061178-Poelwijk1" target="_blank">[15]</a>) b) Illustrating how reciprocal sign epistasis causes the irregularity in the shape of a neutral network. Dots are viable genotypes and edges connect genotypes equal except for one mutation. We assume the two unfit genotypes in an RSE geometry are unviable (dashed dots) and the two fit genotypes are viable. Therefore RSE will be responsible for the gaps in neutral networks that lead to the irregular shape (loss of the dashed edges and dots in the neutral network shown). c) Examples of average functional neutrality landscapes for 3 gene regulatory network mechanisms capable of interpreting a morphogen gradient. Topologies are vertices and single mutant neighbors are connected via edges (as illustrated by the two topologies in the Frozen Oscillator average functional neutrality landscape). Topologies are spaced in the y-axis according to their average functional neutrality (fraction of viable parameter space capable of performing the morphogen interpretation function) and in the x-axis to reduce edge-crossing. Mutant neighborhoods where statistically significant RSE exists are colored blue. d) The number of topologies and the incidence of RSE for each of the different mechanisms. The amount of RSE normalized to the number of topologies in the landscape can be found on the bottom row.</p

Media 1: OPTiSPIM: integrating optical projection tomography in light sheet microscopy extends specimen characterization to nonfluorescent contrasts

Originally published in Optics Letters on 15 February 2014 (ol-39-4-1053

Estimated and theoretical probabilities for a clone to cross the boundary as a function of its position along the AP axis.

<p>(A) The scatter plot shows the size of the observed clones versus its centre position along the AP axis of the rhombomere. Radii have been measured as relative to the AP length of the rhombomere (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0010112#s3" target="_blank">Materials and Methods</a>). Colour of each clone has been chosen to reflect if it respects the boundary (red circles) or it crosses the boundary (green circles). (B) Estimated and theoretical probabilities for a clone to cross the boundary as a function of its position along the AP axis. Red circles show the horizontal position of the centre of observed clones along the AP axis of the rhombomere (it has been rescaled to [0,1]). Clones crossing the boundary have been placed in vertical position 1, clones respecting the boundary in vertical position 0. The red line is the probability of crossing the boundary as given by a generalized additive model fitted to data. Grey step lines show a discrete version of the estimated probability as given by the fraction of clones contained in each interval that cross the boundary. The black line is the probability of crossing the boundary as given by the theoretical model that assumes no boundary effect on the behaviour of clones.</p

Relative frequencies of induction (and therefore recombination).

<p>n: number of embryos.</p><p>F: total relative frequency.</p><p>HB F: frequency within the hindbrain.</p><p>Pregnant mothers were administrated with TM at different developmental stages. Embryonic development proceeds until the desired observation stage. n, number of studied embryos; F, total relative frequency (<i>x/y</i>) where <i>x</i> is the number of embryos displaying recombination events, and <i>y</i> the total number of embryos per experimental group; HB F, relative frequency within the hindbrain.</p

Measure of the clone size and position.

<p>Clone radius was measured as the half-AP length of the clone (c/2) relative to the rhombomere AP length (b), (radius = (c/2)/b. Position of the clone was established by measuring from the centre of the clone to its immediately anterior rhombomeric boundary (a). Position of the clone was then referred as a percentage of the length of the rhombomere at the level of the clone centre (b) (a/b x 100).</p

Behaviour of the clones in respect to the rhombomeric boundaries.

<p>Theoretical probabilities of crossing, respecting and failing to meet the rhombomeric boundaries by chance were computed from the sizes of clones relative to the AP length of the rhombomere, accounting for the measure error, as in ^{<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0010112#pone.0010112-Fraser1" target="_blank">[8]</a>}. We checked whether observed data do fit this theoretical probabilities using a classical χ² goodness-of-fit test. Results showed that we can reject the null hypothesis that observed data could come from the theoretical model (p<10⁻²⁸, df = 2).</p

Media 3: Image formation by linear and nonlinear digital scanned light-sheet fluorescence microscopy with Gaussian and Bessel beam profiles

Originally published in Biomedical Optics Express on 01 July 2012 (boe-3-7-1492

GDF5^W414R is positioned within the NOG and BMPR1A/B binding interface of the GDF5 dimer.

<p><b>A</b>: 3D presentation of the human GDF5 homodimer (PDB 1waq). The topology of the GDF5 monomer comprises two ß-sheets forming the fingers as well as the four-turn α-helix with the preceding pre-helix loop. The mutations are highlighted in pink (GDF5^W414R), violet (GDF5^R399C) and orange (GDF5^E491K). The image of the GDF5 structure was visualized using PyMol (<a href="http://www.pymol.org/" target="_blank">http://www.pymol.org/</a>). <b>B</b>: Protein sequence alignment of human, mouse and chicken GDF5 comprising the seven cysteine residues (bold) of the mature domain. Numbering is referred to the pro-protein sequence. Amino acids predicted to form the NOG binding interface are depicted as framed white boxes and based on the BMP7:NOG complex (PDB 1m4u). Residues predicted to be involved in BMPR1A binding are shown as grey boxes and refer to the BMP2:BMPR1A structure (PDB 1rew). Black boxes mark amino acids that bind to BMPR1B (PDB 3evs). Arrows indicate the mutated sites for GDF5^W414R, GDF5^R399C and GDF5^E491K. Note that GDF5^W414R and GDF5^E491K are located within the NOG binding site. Moreover, all three mutations interfere with the BMP type I receptor (BMPR1A and BMPR1B) binding interface.</p