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Cellular Dynamics (cellular + dynamics)
Selected AbstractsCellular dynamics in the draining lymph nodes during sensitization and elicitation phases of contact hypersensitivityCONTACT DERMATITIS, Issue 5 2007Jeppe Madura Larsen Background:, The different role of various immunological effector cells in contact hypersensitivity (CHS) is receiving increased attention. During the past decade, the involvement of different cell types in CHS has been investigated by the use of antibody-induced depletion of specific subtypes of immunological cells and by studying knockout mice lacking one or more of these immunological cell populations. Objectives:, To develop a method for studying the collective cellular dynamics of immune cells in the draining lymph nodes during CHS in intact animals. Patients/Methods:, Mice were sensitized and/or challenged with 2,4-dinitrofluorobenzene or oxazolone. Using multi-parameter flow cytometry we determined the proliferation, activation state, and absolute number of helper T cells, cytotoxic T cells, B cells, and natural killer cells in the draining lymph nodes. Results:, The presented method can be applied to evaluate the effect of different contact allergens on various cell populations of the immune system. Conclusions:, Our study support recent findings that several cell types seem to be involved in CHS. [source] Cellular dynamics of epithelial clefting during branching morphogenesis of the mouse submandibular glandDEVELOPMENTAL DYNAMICS, Issue 6 2010Yuichi Kadoya Abstract We cultured the rudimental submandibular gland (SMG) of mice with a non,cell-permeable fluorescent tracer, and observed cell behavior during epithelial branching morphogenesis using confocal time-lapse microscopy. We traced movements of individual cells as shadowgraph movies. Individual epithelial cells migrated dynamically but erratically. The epithelial cleft extended by wiggling and separated a cluster of cells into two buds during branching. We examined the ultrastructure of the clefts in SMG rudiments treated with the laminin peptide A5G77f, which induces epithelial clefting. A short cytoplasmic shelf with a core of microfilaments was found at the deep end of the cleft. We propose that epithelial clefting involves a dynamic movement of cells at the base of the cleft, and the formation of a shelf within a cleft cell. The shelf might form a matrix attachment point at the base of the cleft with a core of microfilaments driving cleft elongation. Developmental Dynamics 239:1739,1747, 2010. © 2010 Wiley-Liss, Inc. [source] Cellular dynamics in the draining lymph nodes during sensitization and elicitation phases of contact hypersensitivityCONTACT DERMATITIS, Issue 5 2007Jeppe Madura Larsen Background:, The different role of various immunological effector cells in contact hypersensitivity (CHS) is receiving increased attention. During the past decade, the involvement of different cell types in CHS has been investigated by the use of antibody-induced depletion of specific subtypes of immunological cells and by studying knockout mice lacking one or more of these immunological cell populations. Objectives:, To develop a method for studying the collective cellular dynamics of immune cells in the draining lymph nodes during CHS in intact animals. Patients/Methods:, Mice were sensitized and/or challenged with 2,4-dinitrofluorobenzene or oxazolone. Using multi-parameter flow cytometry we determined the proliferation, activation state, and absolute number of helper T cells, cytotoxic T cells, B cells, and natural killer cells in the draining lymph nodes. Results:, The presented method can be applied to evaluate the effect of different contact allergens on various cell populations of the immune system. Conclusions:, Our study support recent findings that several cell types seem to be involved in CHS. [source] A novel direct aerodynamically assisted threading methodology for generating biologically viable microthreads encapsulating living primary cellsJOURNAL OF APPLIED POLYMER SCIENCE, Issue 2 2008Sumathy Arumuganathar Abstract In a recent discovery, coaxial electrospinning was explored to encapsulate living organisms within a continuous bio-polymeric microthread from which active biological scaffolds were fabricated (Townsend-Nicholson and Jayasinghe, Biomacromolecules 2006, 7, 3364). The cells were demonstrated to have gone through all expected cellular activity without their viability being compromised. These biologically active threads and scaffolds have direct and tremendous applicability from regenerative to therapeutic medicine. Currently these post-processed cells as composite threads and scaffolds are being investigated in-depth at a cellular level to establish if the processing methodology has any affect on the cellular make-up. We now demonstrate a competing non-electric field driven approach for fabricating composite threads and scaffolds influenced only by a differential pressure. We refer to this novel composite thread to scaffold fabrication methodology as coaxial aerodynamically assisted bio-threading (CAABT). Our investigations firstly, demonstrate that this technique can process handle living organisms without biologically perturbing them in anyway. Secondly the process is elucidated as possessing the ability to form composite active threads from which biologically viable scaffolds are formed. Finally our study employs florescent activated cell sorting (FACScan), a method by which the cellular dynamics and viability are quantified on control and threaded cellular samples at two prescribed time points. In parallel with FACScan, optical comparison of cellular morphology at three time points within a period of three weeks is carried out to photographically observe any changes in the post-processed cellular phenotype. Our developmental investigations into this novel aerodynamically assisted threading methodology has unearthed a unique biomicrofabrication approach, which joins cell electrospinning in the cell threading to scaffold fabrication endeavor. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source] Imaging engineered tissues using structural and functional optical coherence tomographyJOURNAL OF BIOPHOTONICS, Issue 11 2009Xing Liang Abstract As the field of tissue engineering evolves, there will be an increasingly important need to visualize and track the complex dynamic changes that occur within three-dimensional constructs. Optical coherence tomography (OCT), as an emerging imaging technology applied to biological materials, offers a number of significant advantages to visualize these changes. Structural OCT has been used to investigate the longitudinal development of engineered tissues and cell dynamics such as migration, proliferation, detachment, and cell-material interactions. Optical techniques that image functional parameters or integrate multiple imaging modalities to provide complementary contrast mechanisms have been developed, such as the integration of optical coherence microscopy with multiphoton microscopy to image structural and functional information from cells in engineered tissue, optical coherence elastography to generate images or maps of strain to reflect the spatially-dependent biomechanical properties, and spectroscopic OCT to differentiate different cell types. From these results, OCT demonstrates great promise for imaging and visualizing engineered tissues, and the complex cellular dynamics that directly affect their practical and clinical use. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] The involvement of human RECQL4 in DNA double-strand break repairAGING CELL, Issue 3 2010Dharmendra Kumar Singh Summary Rothmund,Thomson syndrome (RTS) is an autosomal recessive hereditary disorder associated with mutation in RECQL4 gene, a member of the human RecQ helicases. The disease is characterized by genomic instability, skeletal abnormalities and predisposition to malignant tumors, especially osteosarcomas. The precise role of RECQL4 in cellular pathways is largely unknown; however, recent evidence suggests its involvement in multiple DNA metabolic pathways. This study investigates the roles of RECQL4 in DNA double-strand break (DSB) repair. The results show that RECQL4-deficient fibroblasts are moderately sensitive to ,-irradiation and accumulate more ,H2AX and 53BP1 foci than control fibroblasts. This is suggestive of defects in efficient repair of DSB's in the RECQL4-deficient fibroblasts. Real time imaging of live cells using laser confocal microscopy shows that RECQL4 is recruited early to laser-induced DSBs and remains for a shorter duration than WRN and BLM, indicating its distinct role in repair of DSBs. Endogenous RECQL4 also colocalizes with ,H2AX at the site of DSBs. The RECQL4 domain responsible for its DNA damage localization has been mapped to the unique N-terminus domain between amino acids 363,492, which shares no homology to recruitment domains of WRN and BLM to the DSBs. Further, the recruitment of RECQL4 to laser-induced DNA damage is independent of functional WRN, BLM or ATM proteins. These results suggest distinct cellular dynamics for RECQL4 protein at the site of laser-induced DSB and that it might play important roles in efficient repair of DSB's. [source] | |||||||||||||