Bücher zum Thema „Particles in cell (PIC)“

Flow cytometry is a sensitive and quantitative platform for the measurement of particle fluorescence. In flow cytometry, the particles in a sample flow in single file through a focused laser beam at rates of hundreds to thousands of particles per second. During the time each particle is in the laser beam, on the order of ten microseconds, one or more fluorescent dyes associated with that particle are excited. The fluorescence emitted from each particle is collected through a microscope objective, spectrally filtered, and detected with photomultiplier tubes. Flow cytometry is uniquely capable of the precise and quantitative molecular analysis of genomic sequence information, interactions between purified biomolecules and cellular function. Combined with automated sample handling for increased sample throughput, these features make flow cytometry a versatile platform with applications at many stages of drug discovery. Traditionally, the particles studied are cells, especially blood cells; flow cytometry is used extensively in immunology. This volume shows how flow cytometry is integrated into modern biotechnology, dealing with issues of throughput, content, sensitivity, and high throughput informatics with applications in genomics, proteomics and protein-protein interactions, drug discovery, vaccine development, plant and reproductive biology, pharmacology and toxicology, cell-cell interactions and protein engineering.

This last chapter explores the frontiers of how thermodynamics is currently being applied to biology, moving from the scale of the molecule to the scale of the cell. The key theme is ‘self-assembly’ – the process by which macromolecules spontaneously assemble into larger structures such as cell membranes, cell organelles, cells, and ultimately organisms. The starting point is the simplest process of self-assembly, the formation of a liquid from the condensation of a gas, which draws on some results from Chapter 15, and develops the concept of nucleation, this leads to a discussion of protein aggregation, and how virus particles are formed. The chapter, and the book, ends with a key challenge for the future: how can we deliberately design self-assembling systems that can perform valuable functions?

Atherosclerosis is the main underlying cause of heart disease. The continuous exposure to cardiovascular risk factors induces endothelial activation/dysfunction which enhances the permeability of the endothelial layer and the expression of cytokines/chemokines and adhesion molecules. This results in the accumulation of lipids (low-density lipoprotein particles) in the extracellular matrix and the triggering of an inflammatory response. Accumulated low-density lipoprotein particles suffer modifications and become pro-atherogenic, enhancing leucocyte recruitment and further transmigration across the endothelium into the intima. Infiltrated monocytes differentiate into macrophages which acquire a specialized phenotypic polarization (protective or harmful), depending on the stage of the atherosclerosis progression. Once differentiated, macrophages upregulate pattern recognition receptors capable of engulfing modified low-density lipoprotein, leading to foam cell formation. Foam cells release growth factors and cytokines that promote vascular smooth muscle cell migration into the intima, which then internalize low-density lipoprotein via low-density lipoprotein receptor-related protein-1 receptors. As the plaque evolves, the number of vascular smooth muscle cells decline, whereas the presence of fragile/haemorrhagic neovessels increases, promoting plaque destabilization. Disruption of this atherosclerotic lesion exposes thrombogenic surfaces that initiate platelet adhesion, activation, and aggregation, as well as thrombin generation. Both lipid-laden vascular smooth muscle cells and macrophages release the procoagulant tissue factor, contributing to thrombus propagation. Platelets also participate in progenitor cell recruitment and drive the inflammatory response mediating the atherosclerosis progression. Recent data attribute to microparticles a potential modulatory effect in the overall atherothrombotic process. This chapter reviews our current understanding of the pathophysiological mechanisms involved in atherogenesis, highlights platelet contribution to thrombosis and atherosclerosis progression, and provides new insights into how atherothrombosis may be modulated.

Atherosclerosis is the main underlying cause of heart disease. The continuous exposure to cardiovascular risk factors induces endothelial activation/dysfunction which enhances the permeability of the endothelial layer and the expression of cytokines/chemokines and adhesion molecules. This results in the accumulation of lipids (low-density lipoprotein particles) in the intimal layer and the triggering of an inflammatory response. Accumulated low-density lipoprotein particles attached to the extracellular matrix suffer modifications and become pro-atherogenic, enhancing leucocyte recruitment and further transmigration across the endothelium into the intima. Infiltrated pro-atherogenic monocytes (mainly Mon2) differentiate into macrophages which acquire a specialized phenotypic polarization (protective/M1 or harmful/M2), depending on the stage of the atherosclerosis progression. Once differentiated, macrophages upregulate pattern recognition receptors capable of engulfing modified low-density lipoprotein, leading to foam cell formation. Foam cells release growth factors and cytokines that promote vascular smooth muscle cell migration into the intima, which then internalize low-density lipoproteins via low-density lipoprotein receptor-related protein-1 receptors becoming foam cells. As the plaque evolves, the number of vascular smooth muscle cells decline, whereas the presence of fragile/haemorrhagic neovessels and calcium deposits increases, promoting plaque destabilization. Disruption of this atherosclerotic lesion exposes thrombogenic surfaces rich in tissue factor that initiate platelet adhesion, activation, and aggregation, as well as thrombin generation. Platelets also participate in leucocyte and progenitor cell recruitment are likely to mediate atherosclerosis progression. Recent data attribute to microparticles a modulatory effect in the overall atherothrombotic process and evidence their potential use as systemic biomarkers of thrombus growth. This chapter reviews our current understanding of the pathophysiological mechanisms involved in atherogenesis, highlights platelet contribution to thrombosis and atherosclerosis progression, and provides new insights into how atherothrombosis may be prevented and modulated.

Atherosclerosis is the main underlying cause of heart disease. The continuous exposure to cardiovascular risk factors induces endothelial activation/dysfunction which enhances the permeability of the endothelial layer and the expression of cytokines/chemokines and adhesion molecules. This results in the accumulation of lipids (low-density lipoprotein particles) in the intimal layer and the triggering of an inflammatory response. Accumulated low-density lipoprotein particles attached to the extracellular matrix suffer modifications and become pro-atherogenic, enhancing leucocyte recruitment and further transmigration across the endothelium into the intima. Infiltrated pro-atherogenic monocytes (mainly Mon2) differentiate into macrophages which acquire a specialized phenotypic polarization (protective/M1 or harmful/M2), depending on the stage of the atherosclerosis progression. Once differentiated, macrophages upregulate pattern recognition receptors capable of engulfing modified low-density lipoprotein, leading to foam cell formation. Foam cells release growth factors and cytokines that promote vascular smooth muscle cell migration into the intima, which then internalize low-density lipoproteins via low-density lipoprotein receptor-related protein-1 receptors becoming foam cells. As the plaque evolves, the number of vascular smooth muscle cells decline, whereas the presence of fragile/haemorrhagic neovessels and calcium deposits increases, promoting plaque destabilization. Disruption of this atherosclerotic lesion exposes thrombogenic surfaces rich in tissue factor that initiate platelet adhesion, activation, and aggregation, as well as thrombin generation. Platelets also participate in leucocyte and progenitor cell recruitment are likely to mediate atherosclerosis progression. Recent data attribute to microparticles a modulatory effect in the overall atherothrombotic process and evidence their potential use as systemic biomarkers of thrombus growth. This chapter reviews our current understanding of the pathophysiological mechanisms involved in atherogenesis, highlights platelet contribution to thrombosis and atherosclerosis progression, and provides new insights into how atherothrombosis may be prevented and modulated.

This monograph is a continuation of the monograph by V.V. Sadovnikov. Lateral interaction. Moscow 2006. Publishing house "Anta-Eco", 2006. ISBN 5-9730-0017-6. In this work, the foundations of the theory of heterogeneous catalysis and the theory of chemisorption are more easily formulated. The book consists of two parts, closely related to each other. These are the theoretical foundations of heterogeneous catalysis and chemisorption. In the theory of heterogeneous catalysis, an experiment is described in detail, which must be carried out in order to isolate the stages of a catalytic reaction, to find the stoichiometry of each of the stages. This experiment is based on the need to obtain the exact value of the specific surface area of the catalyst, the number of centers at which the reaction proceeds, and the output curves of each of the reaction products. The procedures for obtaining this data are described in detail. Equations are proposed and solved that allow calculating the kinetic parameters of the nonequilibrium stage and the thermodynamic parameters of the equilibrium stage. The description of the quantitative theory of chemisorption is based on the description of the motion of an atom along a crystal face. The axioms on which this mathematics should be based are formulated, the mathematical apparatus of the theory is written and the most detailed instructions on how to use it are presented. The first axiom: an atom, moving along the surface, is present only in places with minima of potential energy. The second axiom: the face of an atom is divided into cells, and the position of the atom on the surface of the face is set by one parameter: the cell number. The third axiom: the atom interacts with the surrounding material bodies only at the points of minimum potential energy. The fourth axiom: the solution of the equations is a map of the arrangement of atoms on the surface. The fifth axiom: quantitative equations are based on the concept of a statistically independent particle. The formation energies of these particles and their concentration are calculated by the developed program. The program based on these axioms allows you to simulate and calculate the interaction energies of atoms on any crystal face. The monograph is intended for students, post-graduate students and researchers studying work and working in petrochemistry and oil refining.

Influenza is a highly infectious, acute illness which has affected humans and animals since ancient times. Influenza viruses form the Orthomyxoviridae family and are grouped into types A, B, and C on the basis of the antigenic nature of the internal nucleocapsid or the matrix protein. Infl uenza A viruses infect a large variety of animal species, including humans, pigs, horses, sea mammals, and birds, occasionally producing devastating pandemics in humans, such as in 1918 when it has been estimated that between 50–100 million deaths occurred worldwide.There are two important viral surface glycoproteins, the haemagglutinin (HA) and neuraminidase (NA). The HA binds to sialic acid receptors on the membrane of host cells and is the primary antigen against which a host’s antibody response is targeted. The NA cleaves the sialic acid bond attaching new viral particles to the cell membrane of host cells allowing their release. The NA is also the target of the neuraminidase inhibitor class of antiviral agents that include oseltamivir and zanamivir and newer agents such as peramivir. Both these glycoproteins are important antigens for inducing protective immunity in the host and therefore show the greatest variation.Influenza A viruses are classified into 16 antigenically distinct HA (H1–16) and 9 NA subtypes (N1–9). Although viruses of relatively few subtype combinations have been isolated from mammalian species, all subtypes, in most combinations, have been isolated from birds. Each virus possesses one HA and one NA subtype.Last century, the sudden emergence of antigenically different strains in humans, termed antigenic shift, occurred on three occasions, 1918 (H1N1), 1957 (H2N2) and 1968 (H3N2), resulting in pandemics. The frequent epidemics that occur between the pandemics are as a result of gradual antigenic change in the prevalent virus, termed antigenic drift. Epidemics throughout the world occur in the human population due to infection with influenza A viruses, such as H1N1 and H3N2 subtypes, or with influenza B virus. Phylogenetic studies have led to the suggestion that aquatic birds that show no signs of disease could be the source of many influenza A viruses in other species. The 1918 H1N1 pandemic strain is thought to have arisen as a result of spontaneous mutations within an avian H1N1 virus. However, most pandemic strains, such as the 1957 H2N2, 1968 H3N2 and 2009 pandemic H1N1, are considered to have emerged by genetic re-assortment of the segmented RNA genome of the virus, with the avian and human influenza A viruses infecting the same host.Influenza viruses do not pass readily between humans and birds but transmission between humans and other animals has been demonstrated. This has led to the suggestion that the proposed reassortment of human and avian influenza viruses takes place in an intermediate animal with subsequent infection of the human population. Pigs have been considered the leading contender for the role of intermediary because they may serve as hosts for productive infections of both avian and human viruses, and there is good evidence that they have been involved in interspecies transmission of influenza viruses; particularly the spread of H1N1 viruses to humans. Apart from public health measures related to the rapid identification of cases and isolation. The main control measures for influenza virus infections in human populations involves immunization and antiviral prophylaxis or treatment.