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Three-dimensional Environment (three-dimensional + environment)
Selected AbstractsAdvanced microscopic imaging methods to investigate cortical development and the etiology of mental retardationDEVELOPMENTAL DISABILITIES RESEARCH REVIEW, Issue 4 2005Tarik F. Haydar Abstract Studies on human patients and animal models of disease have shown that disruptions in prenatal and early postnatal brain development are a root cause of mental retardation. Since proper brain development is achieved by a strict spatiotemporal control of neurogenesis, cell migration, and patterning of synapses, abnormalities in one or more of these events during prenatal development can lead to cognitive dysfunction after birth. Many of underlying causes of mental retardation must therefore be studied in developing brains. To aid in this research, live imaging using laser scanning microscopy (LSM) has recently allowed neuroscientists to delve deeply into the complex three-dimensional environment of the living brain to record dynamic cellular events over time. This review will highlight recent examples of how LSM is being applied to elucidate both normal and abnormal cortical development. © 2005 Wiley-Liss, Inc. MRDD Research Reviews 2005;11:303,316. [source] Griefing in virtual worlds: causes, casualties and coping strategiesINFORMATION SYSTEMS JOURNAL, Issue 6 2009Thomas Chesney Abstract A virtual world is a computer-simulated three-dimensional environment. They are increasingly being used for social and commercial interaction, in addition to their original use for game playing. This paper studies negative behaviour, or ,griefing', inside one virtual world through a series of observations and focus groups with users. Data were collected to identify griefing behaviours and their impact, examine why griefing happens and who the likely targets and perpetrators are, and suggest strategies for coping with it. Findings show that griefing behaviour is common. It is defined as unacceptable, persistent behaviour and is typically targeted at inexperienced residents by those with more knowledge of the virtual world. Community and individual coping strategies are identified and discussed. [source] To breathe or not to breathe: optimal strategies for finding prey in a dark, three-dimensional environmentJOURNAL OF ANIMAL ECOLOGY, Issue 5 2008MARK HINDELL The use of sophisticated telemetry logging devices has revealed that short-finned pilot whales employ energetic sprints to chase down their deep-dwelling prey. These sprints are costly in terms of energy, and therefore oxygen, which is a valuable resource for an animal that has to hold its breath while hunting. This finding highlights the challenges faced by ecologists when trying to develop foraging models for marine predators because many of the key parameters, such as movements in three dimensions, marine prey fields and metabolic adaptations of diving animals, remain largely unknown. [source] Changes in Gene Expression During the Formation of Bioengineered Heart MuscleARTIFICIAL ORGANS, Issue 1 2009Luda Khait Abstract A three-dimensional bioengineered heart muscle (BEHM) construct model had been previously developed, exhibiting contractile forces up to 800 µN. The interest of this study was to determine gene expression levels of biologic markers involved in calcium-handling between BEHM, cell monolayer, and neonatal heart. Cardiac cells were isolated from one litter of F344 rats and organized into groups (n = 5): 4-, 7-, 10-day BEHM and cell monolayer; BEHM was evaluated for cell viability and contractility. Groups were then analyzed for mRNA expression of calcium-handling proteins: myosin heavy chain (MHC) , and ,, Sarcoplasmic reticulum Ca++ ATPase (SERCA) 2, phospholamban (PBL), and ryanodine receptor. BEHM exhibited electrically stimulated active force (208 ± 12 µN day 4, 361 ± 22 µN day 7, and 344 ± 29 µN day 10) and no decrease in cell number. Real-time polymerase chain reaction (PCR) showed an increase in gene expression of all calcium-handling proteins in BEHM at 7 and 10 days compared with monolayers, for example, comparing BEHM to monolayer (7 and 10 days, respectively), MHC-,: 2600-fold increase and a 100-fold increase; MHC-,: 70-fold increase at 10 days; ryanodine receptor: 74-fold increase at 10 days; SERCA: 19-fold increase and sixfold increase; PBL: 158-fold increase and 24-fold increase. It was concluded that a three-dimensional environment is a better culturing condition of cardiac cells than a monolayer. Also, BEHM constructs demonstrated a high similarity to a native myocardium, and is, thus, a good starting foundation for engineered heart muscle. [source] Fibroblast response to interstitial flow: A state-of-the-art reviewBIOTECHNOLOGY & BIOENGINEERING, Issue 1 2010Liu Dan Abstract Interstitial flow (IF) modulates both the biochemical and biophysical cues surrounding cells. It represents a very important regulating mechanism for cell/tissue function and has been commonly utilized in tissue engineering (TE). This article discusses the possible regulating mechanisms of IF on fibroblasts, the various fibroblast responses to IF, the current challenges in understanding the IF,fibroblast relationship and the application of IF for fibroblast involved TE. In particular, IF can affect fibroblast growth at both intracellular (e.g., calcium signaling, protein/proteinase secretion) and cellular (e.g., autocrine/paracrine signaling, proliferation, differentiation, alignment, adhesion, migration) levels. One major challenge for understanding IF,fibroblast interaction has been the determination of the flow and cell growth condition at microlevel especially in a three-dimensional environment. To utilize IF and optimize the fluidic environment for TE, several influencing factors in the system including perfusate composition, flow profile, nutrient supply, signaling molecule effect, scaffold property, and fibroblast type should be considered. Biotechnol. Bioeng. 2010;107: 1,10. © 2010 Wiley Periodicals, Inc. [source] Effect of Matrigel on adenoid cystic carcinoma cell line differentiationINTERNATIONAL JOURNAL OF EXPERIMENTAL PATHOLOGY, Issue 6 2006Márcia M. Marques Summary Adenoid cystic carcinoma (ACC) is a frequent malignant salivary gland neoplasm presenting different growth patterns described as tubular, cribriform and solid, which represent distinct differentiation stages. Cell lines originated from ACCs grown inside three-dimensional environments have not been capable to reproduce all in vivo ACC growth patterns. As ACC cells in vivo present replicated basement membrane, to mimic this situation in vitro ACC cells (CAC2 cells) were grown on the top of a reconstituted basement membrane (Matrigel). Phenotype differences were assessed by light, fluorescence and transmission electron microscopy. The cultures grown on the top of Matrigel presented three-dimensional arrangement of cells intercepted by cellular cords. At these, cell nests pseudocyst formations were observed. This morphological structure entirely reproduced the cribriform growth pattern of ACC. We suggest that the cribriform differentiation of ACC in culture is dependent of proteins and growth factors associated in a bi-dimensional structure. [source] Spongy Polyethersulfone Membrane for Hepatocyte Cultivation: Studies on Human Hepatoma C3A CellsARTIFICIAL ORGANS, Issue 9 2008Andrzej Kinasiewicz Abstract:, There are different types of membranes used for hepatocyte cultivation. In our studies, spongy polyethersulfone (PES) membranes were examined as a support for hepatic cell cultivation in vitro. The extended surface of the membranes allows to introduce a high cell number especially in three-dimensional gel structure. Scanning electron microscopy analysis indicated that C3A cells used in our experiments grew well on PES membranes forming microvilli characteristic for normal hepatocytes. Analysis of cell viability proved that spongy PES membrane is well tolerated by J774 macrophages and did not stimulate nitric oxide synthesis. Bile canalicular structures were observed in fluorescence microscopy after F-actin staining with tetramethyl rhodamine iso-thiocyanate (TRITC)-phalloidin. The C3A cells showed high affinity to the PES membranes and adhered to almost 90% during the initial 24 h of incubation. Albumin production increased during static culture from the value of 805.2 ± 284.4 (ng/24 h/initial 106 cells) during the first days, to 2017.6 ± 505.9 (ng/24 h/initial 106 cells) after 10 days of culture. In conclusion, the spongy PES membranes can be used as scaffold for hepatocyte cultivation, especially for the creation of three-dimensional environments. [source] | |||||||||||||