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Huang Yao-Xiong - - 2011
We developed a technique using quantum dot (QD) as a sensor for quantitative visualization of the surface charge on biological cells with nano-scale resolution. The QD system was designed and synthesized using amino modified CdSe/ZnS nanoparticles. In a specially designed buffer solution, they are positively charged and can homogeneously disperse ...
Hillen Thomas - - 2010
Classical expressions for the tumor control probability (TCP) are based on models for the survival fraction of cancer cells after radiation treatment. We focus on the derivation of expressions for TCP from dynamic cell population models. In particular, we derive a TCP formula for a generalized cell population model that ...
Dingli David - - 2010
Cancer is the consequence of sequential acquisition of mutations within somatic cells. Mutations alter the relative reproductive fitness of cells, enabling the population to evolve in time as a consequence of selection. Cancer therapy itself can select for or against specific subclones. Given the large population of tumor cells, subclones ...
Golubev A - - 2010
Several recent experiments related to fundamental aspects of cell behaviour, such as passing of the restriction point of cell cycle, which are generally interpreted in accordance with the dynamic paradigm implying the use of differential equations operating with the concentrations of cellular components and rate constants of their interactions, are ...
Rolf Julia J Laboratory of Lymphocyte Signalling and Development, Babraham Institute, Cambridge, United - - 2010
The generation of high-affinity Abs is essential for immunity and requires collaboration between B and T cells within germinal centers (GCs). By using novel mouse models with a conditional deletion of the p110δ catalytic subunit of the PI3K pathway, we established that p110δ is required in T cells, but not ...
Goh Fernie F School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, 315 Ferst Dr., Atlanta, GA 30332, - - 2010
Due to the high solubility of oxygen in perfluorocarbons (PFCs), these compounds have been explored for improved cell and tissue oxygenation. The goal of this study is to investigate the effects of a PFC emulsion on cellular growth and function in a tissue engineered construct. A perfluorotributylamine (PFTBA) emulsion was ...
Goodman Rachel M - - 2010
Among ectotherms, individuals raised in cooler temperatures often have larger body size and/or larger cell size. The current study tested whether geographic variation in cell size and plasticity for cell size exist in a terrestrial, ectothermic vertebrate, Anolis carolinensis Voigt, 1832. We demonstrated temperature-induced plasticity in erythrocytes and epithelial cells ...
Barik Debashis D Department of Biological Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, - - 2010
In order for the cell's genome to be passed intact from one generation to the next, the events of the cell cycle (DNA replication, mitosis, cell division) must be executed in the correct order, despite the considerable molecular noise inherent in any protein-based regulatory system residing in the small confines ...
Grote Mathias - - 2010
The term 'cell', in addition to designating fundamental units of life, has also been applied since the nineteenth century to technical apparatuses such as fuel and galvanic cells. This paper shows that such technologies, based on the electrical effects of chemical reactions taking place in containers, had a far-reaching impact ...
Sriyudthsak Kansuporn - - 2010
A number of recent research studies have focused on theoretical and experimental investigation of a bottleneck in a metabolic reaction network. However, there is no study on how the bottleneck affects the performance of a fermentation process when a product is highly toxic and remarkably influences the growth and death ...
Costigliola Nancy - - 2010
When microtubules are depolymerized in spreading cells, they experience morphological oscillations characterized by a period of about a minute, indicating that normal interactions between the microfilament and microtubule systems have been significantly altered. This experimental system provides a test bed for the development of both fine- and coarse-grained models of ...
Turner C - - 2010
Under the cancer stem cell (CSC) hypothesis, sustained metastatic growth requires the dissemination of a CSC from the primary tumour followed by its re-establishment in a secondary site. The epithelial-mesenchymal transition (EMT), a differentiation process crucial to normal development, has been implicated in conferring metastatic ability on carcinomas. Balancing these ...
O'Malley Maureen A - - 2010
The eukaryote cell is one of the most radical innovations in the history of life, and the circumstances of its emergence are still deeply contested. This paper will outline the recent history of attempts to reveal these origins, with special attention to the argumentative strategies used to support claims about ...
Tasoglu Savas - - 2010
The impact and spreading of a compound viscous droplet on a flat surface are studied computationally using a front-tracking method as a model for the single cell epitaxy. This is a technology developed to create two-dimensional and three-dimensional tissue constructs cell by cell by printing cell-encapsulating droplets precisely on a ...
Skorkina M Yu - - 2010
We propose and tested a method for studies of native blood cells by atomic-force microscopy in a humid chamber preserving viability, size, and shape of biological objects. The method has some advantages over scanning in a liquid cell: it allows studying non-fixed blood samples in the form of suspension of ...
Gowthaman Uthaman - - 2010
The germinal center (GC) reaction supports the processes of affinity maturation and class switching in B cells that result in long-lasting humoral immunity. CD4(+) T follicular helper cells (Tfh) participate in the GC reaction to help B cells. However, recent studies highlight the heterogeneity of CD4(+) T cells in GCs, ...
Wong Ieong - - 2010
Significance of single cell measurements stems from the substantial temporal fluctuations and cell-cell variability possessed by individual cells. A major difficulty in monitoring surface non-adherent cells such as bacteria and yeast is that these cells tend to aggregate into clumps during growth, obstructing the tracking or identification of single-cells over ...
Hölttä Teemu - - 2010
Cambial growth was modelled as a function of detailed levelled physiological processes for cell enlargement and water and sugar transport to the cambium. Cambial growth was described at the cell level where local sugar concentration and turgor pressure induce irreversible cell expansion and cell wall synthesis. It was demonstrated how ...
Teka Wondimu W Department of Mathematics, Florida State University, Tallahassee, - - 2011
Bursting electrical activity is ubiquitous in excitable cells such as neurons and many endocrine cells. The technique of fast/slow analysis, which takes advantage of time scale differences, is typically used to analyze the dynamics of bursting in mathematical models. Two classes of bursting oscillations that have been identified with this ...
Khmelinskii Anton - - 2010
During mitosis in Saccharomyces cerevisiae, senescence factors such as extrachromosomal ribosomal DNA circles (ERCs) are retained in the mother cell and excluded from the bud/daughter cell. Shcheprova et al. proposed a model suggesting segregation of ERCs through their association with nuclear pore complexes (NPCs) and retention of pre-existing NPCs in ...
Ling Hong - - 2010
We investigate the robustness and the behaviours of the critical proteins under parameter perturbations of G1/S checkpoint pathways with different levels of DNA-damage, based on a mathematical model of the pathways. We identify the peak times (PTs) of two key proteins as the in silico biomarkers based on the currently ...
Lee Byunghong - - 2010
A series of experiments have been carried out to study the effects of materials quality, surface and interfacial modification, and photon confinement on standard dye-sensitized solar cells. For these studies, both physical and optical characterization of the materials has been performed in detail. In addition, DC and AC impedance measurements ...
Munson Mark E - - 2010
Investigating the response of cells to specific agonists may involve the use of cell tracking dyes to assess the extent of stimulated proliferation, frequently reported as the proliferation index (PI). Calculation of PI uses a model for cell division that expects the cell number to double as cells proliferate through ...
Enikeeva Farida N FN Institute for Information Transmission Problems, the Kharkevich Institute of RAS, Bolshoi Karetny pereulok 19, GSP-4, Moscow 127994, Russia. - - 2010
The success of a phage that infects a bacterial cell possessing a restriction-modification (R-M) system depends on the activities of the host methyltransferase and restriction endonuclease, and the number of susceptible sites in the phage genome. However, there is no model describing this dependency and linking it to observable parameters ...
Besser Achim - - 2010
Mechanical cues like the rigidity of the substrate are main determinants for the decision-making of adherent cells. Here we use a mechano-chemical model to predict the cellular response to varying substrate stiffnesses. The model equations combine the mechanics of contractile actin filament bundles with a model for the Rho-signaling pathway ...
Jiang Hongyuan H Department of Mechanical Engineering and Whitaker Biomedical Engineering Institute, Johns Hopkins University, Baltimore, Maryland 21218, - - 2010
Bacterial cells utilize a living peptidoglycan network (PG) to separate the cell interior from the surroundings. The shape of the cell is controlled by PG synthesis and cytoskeletal proteins that form bundles and filaments underneath the cell wall. The PG layer also resists turgor pressure and protects the cell from ...
Cramer Louise P - - 2010
Directed cell migration requires the breaking of cell symmetry to generate a cell front and a cell rear along an axis approximately aligned with the direction of locomotion. In most cell types, regulated actin polymerization promotes initial cell front formation and its subsequent persistent protrusion, whereas myosin II-based forces are ...
Doinikov Alexander A - - 2010
There are numerous experimental investigations on sonoporation, while the theoretical background of this phenomenon still is in its infancy. One of the suggested mechanisms of sonoporation is linked to shear stress exerted on the cell membrane by acoustic microstreaming generated by a contrast microbubble pulsating nearby a cell. Currently, the ...
Detzel Christopher J - - 2010
An increasing demand for products such as tissues, proteins, and antibodies from mammalian cell suspension cultures is driving interest in increasing production through high-cell density bioreactors. The centrifugal bioreactor (CCBR) retains cells by balancing settling forces with surface drag forces due to medium throughput and is capable of maintaining cell ...
Schuster Stefan - - 2010
The engineering of microorganisms to produce a variety of extracellular enzymes (exoenzymes), for example for producing renewable fuels and in biodegradation of xenobiotics, has recently attracted increasing interest. Productivity is often reduced by "cheater" mutants, which are deficient in exoenzyme production and benefit from the product provided by the "cooperating" ...
Solow Andrew R - - 2010
There is growing interest in predicting the abundance of a species in a region from the occupancy of cells in a uniform grid overlaid on the region. When the number of individuals in each cell follows a negative binomial distribution, prediction is in general not possible from the number of ...
Morata Gines - - 2010
We have generated wing disc compartments that contain marked fast growing M+ clones surrounded by slow dividing M/+ cells. Under these conditions the interactions between fast and slow dividing cells at the clone borders frequently lead to cell competition. However, our assay suppressing apoptosis indicates that cell competition plays no ...
Boczko Erik M EM Department of Biomedical Informatics, Vanderbilt University, Nashville, - - 2010
Biologists have long observed periodic-like oxygen consumption oscillations in yeast populations under certain conditions, and several unsatisfactory explanations for this phenomenon have been proposed. These ‘autonomous oscillations’ have often appeared with periods that are nearly integer divisors of the calculated doubling time of the culture. We hypothesize that these oscillations ...
Tay SavaƟ S Department of Bioengineering, Stanford University, Stanford, California 94305, - - 2010
Cells operate in dynamic environments using extraordinary communication capabilities that emerge from the interactions of genetic circuitry. The mammalian immune response is a striking example of the coordination of different cell types. Cell-to-cell communication is primarily mediated by signalling molecules that form spatiotemporal concentration gradients, requiring cells to respond to ...
Dokukina Irina V - - 2010
To function efficiently in the body, the biological cells must have the ability to sense the external environment. Mechanosensitivity toward the extracellular matrix was identified as one of the sensing mechanisms affecting cell behavior. It was shown experimentally that a fibroblast cell prefers locomoting over the stiffer substrate when given ...
Kim Min-Cheol - - 2010
To successfully perform biological experiments on bacteria in microfluidic devices, control of micron-scale cell motion in the chip-sized environment is essential. Here we describe a new method for simulating the motion of individual bacterial cells in a microfluidic device using a one-way coupling Lagrangian approach combined with rigid body theory. ...
Stamatakis Michail - - 2010
Several approaches have been used in the past to model heterogeneity in bacterial cell populations, with each approach focusing on different source(s) of heterogeneity. However, a holistic approach that integrates all the major sources into a comprehensive framework applicable to cell populations is still lacking. In this work we present ...
Roscini Luca - - 2010
Fourier Transform InfraRed (FTIR) spectroscopy is an increasingly used technique in biology, especially for whole cell metabolomic fingerprint. The reproducibility of this technique is influenced by a large number of factors such as the physiological state of cells, sample manipulation and growth conditions. Evidence exists suggesting that the cell shape ...
Di Garbo A - - 2010
A nonlinear mathematical model is used to investigate the time evolution of the cell populations in colon crypts (stem, semidifferentiated and fully differentiated cells). To mimic pathological alteration of the biochemical pathways leading to abnormal proliferative activity of the population of semidifferentiated cells their renewal rate is assumed to be ...
Verma Piyush - - 2010
The controlled insertion of artificial nanostructures into biological cells has been utilized for patch clamping, targeted drug delivery, cell lysing, and cell mechanics measurements. In this work, an elastic continuum model is implemented to treat the deformation of spherical cells in solution due to their interaction with cylindrical probes. At ...
Li Minggan - - 2010
Emerging biomanufacturing processes involve incorporation of living cells into various processes and systems by employing different cell manipulation techniques. Among them, biodispensing, in which the cell suspension is extruded via a fine needle under pressurized air, is a promising technique because of its high efficiency. Cells in this process are ...
Van Liedekerke P - - 2010
This paper is concerned with addressing how biological cells react to mechanical impulse. We propose a particle based model to numerically study the mechanical response of these cells with subcellular detail. The model focuses on a plant cell in which two important features are present: (1) the cell's interior liquidlike ...
Melke Pontus - - 2010
Although bacteria are unicellular organisms, they have the ability to act in concert by synthesizing and detecting small diffusing autoinducer molecules. The phenomenon, known as quorum sensing, has mainly been proposed to serve as a means for cell-density measurement. Here, we use a cell-based model of growing bacterial microcolonies to ...
Schauer Kristine - - 2010
We developed a computational imaging approach that describes the three-dimensional spatial organization of endomembranes from micromanipulation-normalized mammalian cells with probabilistic density maps. Applied to several well-known marker proteins, this approach revealed the average steady-state organization of early endosomes, multivesicular bodies or lysosomes, endoplasmic reticulum exit sites, the Golgi apparatus and ...
Sabart M - - 2010
With the aim of explaining the variations in microcystin (MC) concentrations during cyanobacterial blooms, we studied several Microcystis aeruginosa populations blooming in different freshwater ecosystems located in the same geographical area. As assessed by real-time PCR, it appeared that the potentially MC-producing cells (mcyB(+)) were predominant (70 to 100%) in ...
Turner C - - 2010
Under the cancer stem cell (CSC) hypothesis, sustained metastatic growth requires the dissemination of a CSC from the primary tumour followed by its re-establishment in a secondary site. The epithelial-mesenchymal transition (EMT), a differentiation process crucial to normal development, has been implicated in conferring metastatic ability on carcinomas. Balancing these ...
Sakaguchi Hitoshi - - 2010
Regulatory policies in Europe prohibited the testing of cosmetic ingredients in animals for a number of toxicological endpoints. Currently no validated non-animal test methods exist for skin sensitization. Evaluation of changes in cell surface marker expression in dendritic cell (DC)-surrogate cell lines represents one non-animal approach. The human Cell Line ...
Mather William W Department of Bioengineering, UCSD, 9500 Gilman Dr., La Jolla, California 92093-0412, - - 2010
Flows of cells growing as a quasimonolayer in a confined space can exhibit streaming, with narrow streams of fast-moving cells flowing around clusters of slowly moving cells. We observed and analyzed this phenomenon experimentally for E. coli bacteria proliferating in a microfluidic cell trap using time-lapse microscopy. We also performed ...
Xiong Yuguang Y Department of Pharmacology and Systems Therapeutics, Mount Sinai School of Medicine, New York, New York, - - 2010
Cell motility is important for many developmental and physiological processes. Motility arises from interactions between physical forces at the cell surface membrane and the biochemical reactions that control the actin cytoskeleton. To computationally analyze how these factors interact, we built a three-dimensional stochastic model of the experimentally observed isotropic spreading ...
Kozlowski J - - 2010
We examined cell size correlations between tissues, and cell size to body mass relationships in passerine birds, amphibians and mammals. The size correlated highly between all cell types in birds and amphibians; mammalian tissues clustered by size correlation in three tissue groups. Erythrocyte size correlated well with the volume of ...
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