Спосіб фіксації гістологічних блоків для виготовлення багатоплощинних зрізів мозочка

В статье описывается способ фиксации гистологических блоков для изготовления многоплоскостных срезов мозжечка, который можно также использовать для гистологического изучения других тканей. Дано подробное описание способа. Обоснованы преимущества его применения. Приведены графические изображения.In article the fixation mode of histological block for preparation of multiplane sections of cerebellum is described. The positive characteristics are well-grounded

The relationship between fractional flow reserve, platelet reactivity and platelet leukocyte complexes in stable coronary artery disease

Background: The presence of stenoses that significantly impair blood flow and cause myocardial ischemia negatively affects prognosis of patients with stable coronary artery disease. Altered platelet reactivity has been associated with impaired prognosis of stable coronary artery disease. Platelets are activated and form complexes with leukocytes in response to microshear gradients caused by friction forces on the arterial wall or flow separation. We hypothesized that the presence of significantly flow-limiting stenoses is associated with altered platelet reactivity and formation of platelet-leukocyte complexes. Methods: One hundred patients with stable angina were studied. Hemodynamic significance of all coronary stenoses was assessed with Fractional Flow Reserve (FFR). Patients were classified FFR-positive (at least one lesion with FFR 0.80). Whole blood samples were stimulated with increasing concentrations of ADP, TRAP, CRP and Iloprost with substimulatory ADP. Expression of P-selectin as platelet activation marker and platelet-leukocyte complexes were measured by flowcytometry. Patients were stratified on clopidogrel use. FFR positive and negative patient groups were compared on platelet reactivity and platelet-leukocyte complexes. Results: Platelet reactivity between FFR-positive patients and FFR-negative patients did not differ. A significantly lower percentage of circulating platelet-neutrophil complexes in FFR-positive patients and a similar non-significant decrease in percentage of circulating platelet-monocyte complexes in FFR-positive patients was observed. Conclusion: The presence of hemodynamically significant coronary stenoses does not alter platelet reactivity but is associated with reduced platelet-neutrophil complexes in peripheral blood of patients with stable coronary artery disease

Increased platelet reactivity is associated with circulating platelet-monocyte complexes and macrophages in human atherosclerotic plaques

Objective: Platelet reactivity, platelet binding to monocytes and monocyte infiltration play a detrimental role in atherosclerotic plaque progression. We investigated whether platelet reactivity was associated with levels of circulating platelet-monocyte complexes (PMCs) and macrophages in human atherosclerotic carotid plaques. Methods: Platelet reactivity was determined by measuring platelet P-selectin expression after platelet stimulation with increasing concentrations of adenosine diphosphate (ADP), in two independent cohorts: the Circulating Cells cohort (n = 244) and the Athero-Express cohort (n = 91). Levels of PMCs were assessed by flow cytometry in blood samples of patients who were scheduled for percutaneous coronary intervention (Circulating Cells cohort). Monocyte infiltration was semi-quantitatively determined by histological examination of atherosclerotic carotid plaques collected during carotid endarterectomy (Athero-Express cohort). Results: We found increased platelet reactivity in patients with high PMCs as compared to patients with low PMCs (median (interquartile range): 4153 (1585-11267) area under the curve (AUC) vs. 9633 (3580-21565) AUC, P<0.001). Also, we observed increased pl

On platelet biology and cardiovascular disease

Cardiovascular disease is one of the major causes of death, being responsible for 30% of the deaths worldwide in 2010. Cardiovascular disease is mainly caused by atherosclerosis. Clinical complications occur when a plaque suddenly ruptures and platelets form a thrombus on the plaque and the coronary artery becomes occluded. Atherosclerotic plaque rupture is the cause of approximately 70% of myocardial infarctions. Blood platelets play a pivotal role in cardiovascular disease, because aggregate formation of blood platelets in response to an unstable atherosclerotic plaque causes acute blockade of blood flow, and subsequent ischemia and infarction. In addition to the role of platelets in arterial thrombosis, it is becoming clearer that platelets also play an important role in the progression of atherosclerosis. Platelet a-granules contain numerous cytokines, chemokines and growth factors, and through interaction with leukocytes and endothelial cells platelets can promote inflammation and atherosclerosis. The central goal of this thesis was to investigate the responsiveness of platelets by means of a-granule release in relation to severity of cardiovascular disease symptoms, and to future cardiovascular disease events. In addition to platelet response in relation to cardiovascular disease, we have identified novel conditions and aspects that regulate platelet function. Chapter 1 addresses a systematic review to the current state of art of cardiovascular disease risk prediction with circulating markers. Chapter 2 describes a study investigating the relation between platelet responsiveness and cardiovascular disease symptoms and future cardiovascular disease events, which are assessed in the CTMM Circulating Cells cohort. We find that ADP platelet responsiveness is reduced in patients with unstable cardiovascular disease. The effect of ischemic coronary artery narrowing on platelet responsiveness is investigated in Chapter 3. We find that although the platelet response of patients with flow limiting stenoses is not different compared to patients without flow-limiting coronary stenoses, the formation of platelet-leukocyte complexes is associated with flow-limiting conditions. The influence of selective serotonin re-uptake inhibitors on platelet granule release is addressed in chapter 4. We find that citalopram is a stronger platelet function inhibitor than paroxetine. In chapter 5 we describe that platelets can release their granules independently of an aggregatory response, which is the result of selective aIIbb3 inhibition. We argue that this has implications for platelet physiologic functions. In Chapter 6, we describe the discovery and characterisation of a novel intracellular signalling molecule that belongs to the class of regulators of the RhoGTPase family. We conclude that this novel intracellular signalling molecule has influence on platelet filopodia formation in response to collagen like surfaces. Lastly, in Chapter 7 the composition of the platelet releasate in response to stimulation of either the thrombin receptor PAR-1, or PAR-4 is described with the use of novel quantitative mass spectrometry techniques. We find that stimulation of either receptor induces similar releasates and intra-cellular phosphorylation pattern

Early CMV reactivation after stem cell transplantation leaves an imprint on the CD8+T-lymphocyte compartment one year post transplantation

Transplantation and immunomodulatio

Measurement of platelet activation with anti‐P‐selectin coated magnetic microparticles

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Measurement of platelet responsiveness using antibody-coated magnetic beads for lab-on-chip applications

We investigate novel methods for the quantification of platelet responsiveness that are suited for implementation in lab-on-a-chip devices. Magnetic beads are convenient carriers for rapid capture and manipulation of biological cells in a miniaturized system. In this article, we demonstrate that antibody-coated magnetic beads can be used to quantify platelet responsiveness. We use anti-CD62P coated beads to capture activated platelets from samples stimulated with a PAR-1 specific agonist SFLLRN, also known as thrombin receptor activator peptide. The responsiveness of the platelets is analyzed via the remaining unbound platelets in the solution and compared to a reference method in which the number of activated platelets is analyzed via fluorescent labeling. The effective concentrations for platelet activation are in agreement for the two assay types, proving that platelet responsiveness can be quantified using antibody-coated magnetic beads. We discuss the outlook for application in lab-on-a-chip devices

Measurement of platelet responsiveness using antibody-coated magnetic beads for lab-on-chip applications

We investigate novel methods for the quantification of platelet responsiveness that are suited for implementation in lab-on-a-chip devices. Magnetic beads are convenient carriers for rapid capture and manipulation of biological cells in a miniaturized system. In this article, we demonstrate that antibody-coated magnetic beads can be used to quantify platelet responsiveness. We use anti-CD62P coated beads to capture activated platelets from samples stimulated with a PAR-1 specific agonist SFLLRN, also known as thrombin receptor activator peptide. The responsiveness of the platelets is analyzed via the remaining unbound platelets in the solution and compared to a reference method in which the number of activated platelets is analyzed via fluorescent labeling. The effective concentrations for platelet activation are in agreement for the two assay types, proving that platelet responsiveness can be quantified using antibody-coated magnetic beads. We discuss the outlook for application in lab-on-a-chip devices