Evaluation of the osteogenic differentiation of gingiva-derived stem cells grown on culture plates or in stem cell spheroids: Comparison of two- and three-dimensional cultures.

Science.gov (United States)

Lee, Sung-Il; Ko, Youngkyung; Park, Jun-Beom

2017-09-01

Three-dimensional cell culture systems provide a convenient in vitro model for the study of complex cell-cell and cell-matrix interactions in the absence of exogenous substrates. The current study aimed to evaluate the osteogenic differentiation potential of gingiva-derived stem cells cultured in two-dimensional or three-dimensional systems. To the best of our knowledge, the present study is the first to compare the growth of gingiva-derived stem cells in monolayer culture to a three-dimensional culture system with microwells. For three-dimensional culture, gingiva-derived stem cells were isolated and seeded into polydimethylsiloxane-based concave micromolds. Alkaline phosphatase activity and alizarin red S staining assays were then performed to evaluate osteogenesis and the degree of mineralization, respectively. Stem cell spheroids had a significantly increased level of alkaline phosphatase activity and mineralization compared with cells from the two-dimensional culture. In addition, an increase in mineralized deposits was observed with an increase in the loading cell number. The results of present study indicate that gingiva-derived stem cell spheroids exhibit an increased osteogenic potential compared with stem cells from two-dimensional culture. This highlights the potential of three-dimensional culture systems using gingiva-derived stem cells for regenerative medicine applications requiring stem cells with osteogenic potential.

Differentiation Potential of Human Chorion-Derived Mesenchymal Stem Cells into Motor Neuron-Like Cells in Two- and Three-Dimensional Culture Systems.

Science.gov (United States)

Faghihi, Faezeh; Mirzaei, Esmaeil; Ai, Jafar; Lotfi, Abolfazl; Sayahpour, Forough Azam; Barough, Somayeh Ebrahimi; Joghataei, Mohammad Taghi

2016-04-01

Many people worldwide suffer from motor neuron-related disorders such as amyotrophic lateral sclerosis and spinal cord injuries. Recently, several attempts have been made to recruit stem cells to modulate disease progression in ALS and also regenerate spinal cord injuries. Chorion-derived mesenchymal stem cells (C-MSCs), used to be discarded as postpartum medically waste product, currently represent a class of cells with self renewal property and immunomodulatory capacity. These cells are able to differentiate into mesodermal and nonmesodermal lineages such as neural cells. On the other hand, gelatin, as a simply denatured collagen, is a suitable substrate for cell adhesion and differentiation. It has been shown that electrospinning of scaffolds into fibrous structure better resembles the physiological microenvironment in comparison with two-dimensional (2D) culture system. Since there is no report on potential of human chorion-derived MSCs to differentiate into motor neuron cells in two- and three-dimensional (3D) culture systems, we set out to determine the effect of retinoic acid (RA) and sonic hedgehog (Shh) on differentiation of human C-MSCs into motor neuron-like cells cultured on tissue culture plates (2D) and electrospun nanofibrous gelatin scaffold (3D).

Apical polarity in three-dimensional culture systems: where to now?

Energy Technology Data Exchange (ETDEWEB)

Inman, J.L.; Bissell, Mina

2010-01-21

Delineation of the mechanisms that establish and maintain the polarity of epithelial tissues is essential to understanding morphogenesis, tissue specificity and cancer. Three-dimensional culture assays provide a useful platform for dissecting these processes but, as discussed in a recent study in BMC Biology on the culture of mammary gland epithelial cells, multiple parameters that influence the model must be taken into account.

Tailor-made three-dimensional hybrid scaffolds for cell cultures

International Nuclear Information System (INIS)

Psycharakis, Stylianos; Melissinaki, Vasileia; Giakoumaki, Anastasia; Ranella, Anthi; Tosca, Androniki

2011-01-01

The construction of the ideal three-dimensional scaffold for cell culture is one of the most intriguing topics in tissue engineering. It has been shown that cells can be cultured on most organic biomimetic materials, which now are losing popularity in favour of novel, hybrid systems. In this study, a series of photosensitive sol-gel hybrid materials, based on silicon-zirconium and silicon-titanium oxides, have been investigated for their suitability in three-dimensional scaffold fabrication. These materials can be structured by two-photon polymerization, a laser-based technique allowing the fabrication of micrometre-size structures with submicron resolution. The work presented here examined the effect of the organic/inorganic composition of the materials on cell behaviour and the establishment of a 'cell-culture friendly' environment. This is vital for cell adhesion, growth and differentiation, as the organic part of the material provides the soft matrix for cell growth, whereas the inorganic component gives the mechanical stability and rigidity of the three-dimensional structures. In addition, the use of femtosecond laser structuring permits the fabrication of a wide range of mechanically stable scaffolds of different sizes and shapes to be tested in terms of cell viability, proliferation and orientation.

Two-dimensional Tissue Image Reconstruction Based on Magnetic Field Data

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J. Dedkova

2012-09-01

Full Text Available This paper introduces new possibilities within two-dimensional reconstruction of internal conductivity distribution. In addition to the electric field inside the given object, the injected current causes a magnetic field which can be measured either outside the object by means of a Hall probe or inside the object through magnetic resonance imaging. The Magnetic Resonance method, together with Electrical impedance tomography (MREIT, is well known as a bio-imaging modality providing cross-sectional conductivity images with a good spatial resolution from the measurements of internal magnetic flux density produced by externally injected currents. A new algorithm for the conductivity reconstruction, which utilizes the internal current information with respect to corresponding boundary conditions and the external magnetic field, was developed. A series of computer simulations has been conducted to assess the performance of the proposed algorithm within the process of estimating electrical conductivity changes in the lungs, heart, and brain tissues captured in two-dimensional piecewise homogeneous chest and head models. The reconstructed conductivity distribution using the proposed method is compared with that using a conventional method based on Electrical Impedance Tomography (EIT. The acquired experience is discussed and the direction of further research is proposed.

Structural Analysis of Three-dimensional Human Neural Tissue derived from Induced Pluripotent Stem Cells

DEFF Research Database (Denmark)

Terrence Brooks, Patrick; Rasmussen, Mikkel Aabech; Hyttel, Poul

2016-01-01

Objective: The present study aimed at establishing a method for production of a three-dimensional (3D) human neural tissue derived from induced pluripotent stem cells (iPSCs) and analyzing the outcome by a combination of tissue ultrastructure and expression of neural markers. Methods: A two......-step cell culture procedure was implemented by subjecting human iPSCs to a 3D scaffoldbased neural differentiation protocol. First, neural fate-inducing small molecules were used to create a neuroepithelial monolayer. Second, the monolayer was trypsinized into single cells and seeded into a porous...... polystyrene scaffold and further cultured to produce a 3D neural tissue. The neural tissue was characterized by a combination of immunohistochemistry and transmission electron microscopy (TEM). Results: iPSCs developed into a 3D neural tissue expressing markers for neural progenitor cells, early neural...

Increased Paracrine Immunomodulatory Potential of Mesenchymal Stromal Cells in Three-Dimensional Culture

DEFF Research Database (Denmark)

Follin, Bjarke; Juhl, Morten; Cohen, Smadar

2016-01-01

Mesenchymal stromal/stem cells (MSCs) have been investigated extensively through the past years, proving to have great clinical therapeutic potential. In vitro cultivation of MSCs in three-dimensional (3D) culture systems, such as scaffolds, hydrogels, or spheroids, have recently gained attention...... for tissue engineering applications. Studies on MSC spheroids demonstrated that such cultivation increased the paracrine immunomodulatory potential of the MSCs, accompanied by phenotypic alterations. In this review, we gather results from recent experimental studies on the immunomodulatory abilities of MSCs...... when cultured as spheroids or in biomaterials like scaffolds or hydrogels compared to regular two-dimensional (2D) culture and show that alterations occurring to MSCs in spheroids also occur in MSCs in biomaterials. We provide a brief description of known mechanisms of MSC immunomodulatory capacity...

Tailor-made three-dimensional hybrid scaffolds for cell cultures

Energy Technology Data Exchange (ETDEWEB)

Psycharakis, Stylianos; Melissinaki, Vasileia; Giakoumaki, Anastasia; Ranella, Anthi [Institute of Electronic Structure and Laser, Foundation for Research and Technology Hellas, PO Box 1527, 711 10 Heraklion, Crete (Greece); Tosca, Androniki, E-mail: ranthi@iesl.forth.gr [Department of Medicine, University of Crete, 710 03 Heraklion, Crete (Greece)

2011-08-15

The construction of the ideal three-dimensional scaffold for cell culture is one of the most intriguing topics in tissue engineering. It has been shown that cells can be cultured on most organic biomimetic materials, which now are losing popularity in favour of novel, hybrid systems. In this study, a series of photosensitive sol-gel hybrid materials, based on silicon-zirconium and silicon-titanium oxides, have been investigated for their suitability in three-dimensional scaffold fabrication. These materials can be structured by two-photon polymerization, a laser-based technique allowing the fabrication of micrometre-size structures with submicron resolution. The work presented here examined the effect of the organic/inorganic composition of the materials on cell behaviour and the establishment of a 'cell-culture friendly' environment. This is vital for cell adhesion, growth and differentiation, as the organic part of the material provides the soft matrix for cell growth, whereas the inorganic component gives the mechanical stability and rigidity of the three-dimensional structures. In addition, the use of femtosecond laser structuring permits the fabrication of a wide range of mechanically stable scaffolds of different sizes and shapes to be tested in terms of cell viability, proliferation and orientation.

Gastrointestinal Epithelial Organoid Cultures from Postsurgical Tissues.

Science.gov (United States)

Hahn, Soojung; Yoo, Jongman

2017-08-17

An organoid is a cellular structure three-dimensionally (3D) cultured from self-organizing stem cells in vitro, which has a cell population, architectures, and organ specific functions like the originating organs. Recent advances in the 3D culture of isolated intestinal crypts or gastric glands have enabled the generation of human gastrointestinal epithelial organoids. Gastrointestinal organoids recapitulate the human in vivo physiology because of all the intestinal epithelial cell types that differentiated and proliferated from tissue resident stem cells. Thus far, gastrointestinal organoids have been extensively used for generating gastrointestinal disease models. This protocol describes the method of isolating a gland or crypt using stomach or colon tissue after surgery and establishing them into gastroids or colonoids.

Hydrogel microfabrication technology toward three dimensional tissue engineering

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Fumiki Yanagawa

2016-03-01

Full Text Available The development of biologically relevant three-dimensional (3D tissue constructs is essential for the alternative methods of organ transplantation in regenerative medicine, as well as the development of improved drug discovery assays. Recent technological advances in hydrogel microfabrication, such as micromolding, 3D bioprinting, photolithography, and stereolithography, have led to the production of 3D tissue constructs that exhibit biological functions with precise 3D microstructures. Furthermore, microfluidics technology has enabled the development of the perfusion culture of 3D tissue constructs with vascular networks. In this review, we present these hydrogel microfabrication technologies for the in vitro reconstruction and cultivation of 3D tissues. Additionally, we discuss current challenges and future perspectives of 3D tissue engineering.

Establishment of the optimum two-dimensional electrophoresis system of ovine ovarian tissue.

Science.gov (United States)

Jia, J L; Zhang, L P; Wu, J P; Wang, J; Ding, Q

2014-08-26

Lambing performance of sheep is the most important economic trait and is regarded as a critic factoring affecting the productivity in sheep industry. Ovary plays the most roles in lambing trait. To establish the optimum two-dimensional electrophoresis system (2-DE) of ovine ovarian tissue, the common protein extraction methods of animal tissue (trichloroacetic acid/acetone precipitation and direct schizolysis methods) were used to extract ovine ovarian protein, and 17-cm nonlinear immobilized PH 3-10 gradient strips were used for 2-DE. The sample handling, loading quantity of the protein sample, and isoelectric focusing (IEF) steps were manipulated and optimized in this study. The results indicate that the direct schizolysis III method, a 200-μg loading quantity of the protein sample, and IEF steps II (20°C active hydration, 14 h→500 V, 1 h→1000 V 1 h→1000-9000 V, 6 h→80,000 VH→500 V 24 h) are optimal for 2-DE analysis of ovine ovarian tissue. Therefore, ovine ovarian tissue proteomics 2-DE was preliminarily established by the optimized conditions in this study; meanwhile, the conditions identified herein could provide a reference for ovarian sample preparation and 2-DE using tissues from other animals.

The fabrication and cell culture of three-dimensional rolled scaffolds with complex micro-architectures

International Nuclear Information System (INIS)

Liu Yaxiong; Li Xiao; Qu Xiaoli; Zhu Lin; He Jiankang; Zhao Qian; Wu Wanquan; Li Dichen

2012-01-01

Cell cultures for tissue engineering are traditionally prepared on two-dimensional or three-dimensional scaffolds with simple pores; however, this limits mass transportation, which is necessary for cell viability and function. In this paper, an innovative method is proposed for fabricating porous scaffolds with designed complex micro-architectures. Channels devised by computer-aided design were used to simulate features of blood vessels in native rat liver. Rapid prototyping and microreplication were used to produce a negative polydimethylsiloxane mold, and then a planar porous scaffold with predefined microchannel parameters was obtained by freeze-drying a silk fibroin/gelatin solution of an optimized concentration. After seeding with rat primary hepatocytes, the planar scaffold was rolled up to build spatial channels. By reconstructing the three-dimensional channel model in the scaffold in the form of micro-computed topography data and observing the cross-sections of the scroll, we confirmed that the bent channels were still interconnected, with restricted deviations. A comparison of the primary hepatocyte culture in the scaffolds with and without the devised channels proved that our design influenced cell organization and improved cell survival and proliferation. This method can be used for the construction of complex tissues for implantation and for culturing cells in vitro for biological tests and observations.

Scaffold Free Bio-orthogonal Assembly of 3-Dimensional Cardiac Tissue via Cell Surface Engineering

Science.gov (United States)

Rogozhnikov, Dmitry; O'Brien, Paul J.; Elahipanah, Sina; Yousaf, Muhammad N.

2016-12-01

There has been tremendous interest in constructing in vitro cardiac tissue for a range of fundamental studies of cardiac development and disease and as a commercial system to evaluate therapeutic drug discovery prioritization and toxicity. Although there has been progress towards studying 2-dimensional cardiac function in vitro, there remain challenging obstacles to generate rapid and efficient scaffold-free 3-dimensional multiple cell type co-culture cardiac tissue models. Herein, we develop a programmed rapid self-assembly strategy to induce specific and stable cell-cell contacts among multiple cell types found in heart tissue to generate 3D tissues through cell-surface engineering based on liposome delivery and fusion to display bio-orthogonal functional groups from cell membranes. We generate, for the first time, a scaffold free and stable self assembled 3 cell line co-culture 3D cardiac tissue model by assembling cardiomyocytes, endothelial cells and cardiac fibroblast cells via a rapid inter-cell click ligation process. We compare and analyze the function of the 3D cardiac tissue chips with 2D co-culture monolayers by assessing cardiac specific markers, electromechanical cell coupling, beating rates and evaluating drug toxicity.

Induction of carcinoembryonic antigen expression in a three-dimensional culture system

Science.gov (United States)

Jessup, J. M.; Brown, D.; Fitzgerald, W.; Ford, R. D.; Nachman, A.; Goodwin, T. J.; Spaulding, G.

1994-01-01

MIP-101 is a poorly differentiated human colon carcinoma cell line established from ascites that produces minimal amounts of carcinoembryonic antigen (CEA), a 180 kDa glycoprotein tumor marker, and nonspecific cross-reacting antigen (NCA), a related protein that has 50 and 90 kDa isoforms, in vitro in monolayer culture. MIP-101 produces CEA when implanted into the peritoneum of nude mice but not when implanted into subcutaneous tissue. We tested whether MIP-101 cells may be induced to express CEA when cultured on microcarrier beads in three-dimensional cultures, either in static cultures as non-adherent aggregates or under dynamic conditions in a NASA-designed low shear stress bioreactor. MIP- 101 cells proliferated well under all three conditions and increased CEA and NCA production 3 - 4 fold when grown in three-dimensional cultures compared to MIP-101 cells growing logarithmically in monolayers. These results suggest that three-dimensional growth in vitro simulates tumor function in vivo and that three-dimensional growth by itself may enhance production of molecules that are associated with the metastatic process.

Metabolomics reveals the heterogeneous secretome of two entomopathogenic fungi to ex vivo cultured insect tissues.

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Charissa de Bekker

Full Text Available Fungal entomopathogens rely on cellular heterogeneity during the different stages of insect host infection. Their pathogenicity is exhibited through the secretion of secondary metabolites, which implies that the infection life history of this group of environmentally important fungi can be revealed using metabolomics. Here metabolomic analysis in combination with ex vivo insect tissue culturing shows that two generalist isolates of the genus Metarhizium and Beauveria, commonly used as biological pesticides, employ significantly different arrays of secondary metabolites during infectious and saprophytic growth. It also reveals that both fungi exhibit tissue specific strategies by a distinguishable metabolite secretion on the insect tissues tested in this study. In addition to showing the important heterogeneous nature of these two entomopathogens, this study also resulted in the discovery of several novel destruxins and beauverolides that have not been described before, most likely because previous surveys did not use insect tissues as a culturing system. While Beauveria secreted these cyclic depsipeptides when encountering live insect tissues, Metarhizium employed them primarily on dead tissue. This implies that, while these fungi employ comparable strategies when it comes to entomopathogenesis, there are most certainly significant differences at the molecular level that deserve to be studied.

Three-dimensional spheroid culture promotes odonto/osteoblastic differentiation of dental pulp cells.

Science.gov (United States)

Yamamoto, Mioko; Kawashima, Nobuyuki; Takashino, Nami; Koizumi, Yu; Takimoto, Koyo; Suzuki, Noriyuki; Saito, Masahiro; Suda, Hideaki

2014-03-01

Three-dimensional (3D) spheroid culture is a method for creating 3D aggregations of cells and their extracellular matrix without a scaffold mimicking the actual tissues. The aim of this study was to evaluate the effects of 3D spheroid culture on the phenotype of immortalized mouse dental papilla cells (MDPs) that have the ability to differentiate into odontoblasts. We cultured MDPs for 1, 3, 7, and 14 days in 96-well low-attachment culture plates for 3D spheroid culture or flat-bottomed plates for two-dimensional (2D) monolayer culture. Cell proliferation and apoptosis were detected by immunohistochemical staining of Ki67 and cleaved caspase-3, respectively. Hypoxia was measured by the hypoxia probe LOX-1. Odonto/osteoblastic differentiation marker gene expression was evaluated by quantitative PCR. We also determined mineralized nodule formation, alkaline phosphatase (ALP) activity, and dentine matrix protein-1 (DMP1) expression. Vinculin and integrin signalling-related proteins were detected immunohistochemically. Odonto/osteoblastic marker gene expression and mineralized nodule formation were significantly up-regulated in 3D spheroid-cultured MDPs compared with those in 2D monolayer-cultured MDPs (podonto/osteoblastic differentiation of MDPs, which may be mediated by integrin signalling. Copyright © 2013 Elsevier Ltd. All rights reserved.

Designing 3-Dimensional In Vitro Oviduct Culture Systems to Study Mammalian Fertilization and Embryo Production.

Science.gov (United States)

Ferraz, Marcia A M M; Henning, Heiko H W; Stout, Tom A E; Vos, Peter L A M; Gadella, Bart M

2017-07-01

The oviduct was long considered a largely passive conduit for gametes and embryos. However, an increasing number of studies into oviduct physiology have demonstrated that it specifically and significantly influences gamete interaction, fertilization and early embryo development. While oviduct epithelial cell (OEC) function has been examined during maintenance in conventional tissue culture dishes, cells seeded into these two-dimensional (2-D) conditions suffer a rapid loss of differentiated OEC characteristics, such as ciliation and secretory activity. Recently, three-dimensional (3-D) cell culture systems have been developed that make use of cell inserts to create basolateral and apical medium compartments with a confluent epithelial cell layer at the interface. Using such 3-D culture systems, OECs can be triggered to redevelop typical differentiated cell properties and levels of tissue organization can be developed that are not possible in a 2-D culture. 3-D culture systems can be further refined using new micro-engineering techniques (including microfluidics and 3-D printing) which can be used to produce 'organs-on-chips', i.e. live 3-D cultures that bio-mimic the oviduct. In this review, concepts for designing bio-mimic 3-D oviduct cultures are presented. The increased possibilities and concomitant challenges when trying to more closely investigate oviduct physiology, gamete activation, fertilization and embryo production are discussed.

Three-Dimensional Cell Culture Models for Infectious Disease and Drug Development

Science.gov (United States)

Nickerson, Cheryl A.; Honer zu Bentrup, Kerstin; Ott, C. Mark

2005-01-01

Three-dimensional (3-D) cell cultures hold enormous potential to advance our understanding of infectious disease and to effectively translate basic cellular research into clinical applications. Using novel NASA bioreactor technology, the rotating wall vessel (RWV), we have engineered physiologically relevant 3-D human tissue culture models for infectious disease studies. The design of the RWV is based on the understanding that organs and tissues function in a 3-D environment, and that this 3-D architecture is critical for the differentiated form and function of tissues in vivo. The RWV provides large numbers of cells which are amenable to a wide variety of experimental manipulations and provides an easy, reproducible, and cost-effective approach to enhance differentiated features of cell culture models.

Assessment of Soft Tissue Changes by Cephalometry and Two-Dimensional Photogrammetry in Bilateral Sagittal Split Ramus Osteotomy Cases

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Jan Rustemeyer

2011-07-01

Full Text Available Objectives: We aimed to compare the standard methods of cephalometry and two-dimensional photogrammetry, to evaluate the reliability and accuracy of both methods.Material and Methods: Twenty-six patients (mean age 25.5, standard deviation (SD 5.2 years with Class II relationship and 23 patients with Class III relationship (mean age 26.4, SD 4.7 years who had undergone bilateral sagittal split ramus osteotomy were selected, with a median follow-up of 8 months between pre- and postsurgical evaluation. Pre- and postsurgical cephalograms and lateral photograms were traced and changes were recorded.Results: Pre- and postsurgical measurements of hard tissue angles and distances revealed higher correlations with cephalometrically performed soft tissue measurements of facial convexity (Class II: N-PG, r = - 0.50, P = 0.047; Class III: ANB, r = 0.73, P = 0.005; NaPg , r = 0.71, P = 0.007; and labiomental angle (Class II: SNB, r = 0.72, P = 0.002; ANB, r = - 0.72, P = 0.002; N-B, r = - 0.68, P = 0.004; ANS-Gn, r = 0.71, P = 0.002; Class III: ANS-Gn, r = 0.65, P = 0.043 compared with two-dimensional photogrammetry. However, two-dimensional photogrammetry revealed higher correlation between lower lip length and cephalometrically assessed angular hard tissue changes (Class II: SNB, r = 0.98, P = 0.007; N-B, r = 0.89, P = 0.037; N-Pg, r = 0.90, P = 0.033; Class III: SNB, r = - 0.54, P = 0.060; NAPg, r = - 0.65, P = 0.041; N-Pg, r = 0.58, P = 0.039.Conclusions: Our findings suggest that cephalometry and two-dimensional photogrammetry offer the possibility to complement one another.

Assessment of Soft Tissue Changes by Cephalometry and Two-Dimensional Photogrammetry in Bilateral Sagittal Split Ramus Osteotomy Cases

Science.gov (United States)

Martin, Alice

2011-01-01

ABSTRACT Objectives We aimed to compare the standard methods of cephalometry and two-dimensional photogrammetry, to evaluate the reliability and accuracy of both methods. Material and Methods Twenty-six patients (mean age 25.5, standard deviation (SD) 5.2 years) with Class II relationship and 23 patients with Class III relationship (mean age 26.4, SD 4.7 years) who had undergone bilateral sagittal split ramus osteotomy were selected, with a median follow-up of 8 months between pre- and postsurgical evaluation. Pre- and postsurgical cephalograms and lateral photograms were traced and changes were recorded. Results Pre- and postsurgical measurements of hard tissue angles and distances revealed higher correlations with cephalometrically performed soft tissue measurements of facial convexity (Class II: N-PG, r = - 0.50, P = 0.047; Class III: ANB, r = 0.73, P = 0.005; NaPg , r = 0.71, P = 0.007;) and labiomental angle (Class II: SNB, r = 0.72, P = 0.002; ANB, r = - 0.72, P = 0.002; N-B, r = - 0.68, P = 0.004; ANS-Gn, r = 0.71, P = 0.002; Class III: ANS-Gn, r = 0.65, P = 0.043) compared with two-dimensional photogrammetry. However, two-dimensional photogrammetry revealed higher correlation between lower lip length and cephalometrically assessed angular hard tissue changes (Class II: SNB, r = 0.98, P = 0.007; N-B, r = 0.89, P = 0.037; N-Pg, r = 0.90, P = 0.033; Class III: SNB, r = - 0.54, P = 0.060; NAPg, r = - 0.65, P = 0.041; N-Pg, r = 0.58, P = 0.039). Conclusions Our findings suggest that cephalometry and two-dimensional photogrammetry offer the possibility to complement one another. PMID:24421994

Human breast cancer histoid: an in vitro 3-dimensional co-culture model that mimics breast cancer tissue.

Science.gov (United States)

Kaur, Pavinder; Ward, Brenda; Saha, Baisakhi; Young, Lillian; Groshen, Susan; Techy, Geza; Lu, Yani; Atkinson, Roscoe; Taylor, Clive R; Ingram, Marylou; Imam, S Ashraf

2011-12-01

Progress in our understanding of heterotypic cellular interaction in the tumor microenvironment, which is recognized to play major roles in cancer progression, has been hampered due to unavailability of an appropriate in vitro co-culture model. The aim of this study was to generate an in vitro 3-dimensional human breast cancer model, which consists of cancer cells and fibroblasts. Breast cancer cells (UACC-893) and fibroblasts at various densities were co-cultured in a rotating suspension culture system to establish co-culture parameters. Subsequently, UACC-893, BT.20, or MDA.MB.453 were co-cultured with fibroblasts for 9 days. Co-cultures resulted in the generation of breast cancer histoid (BCH) with cancer cells showing the invasion of fibroblast spheroids, which were visualized by immunohistochemical (IHC) staining of sections (4 µm thick) of BCH. A reproducible quantitative expression of C-erbB.2 was detected in UACC-893 cancer cells in BCH sections by IHC staining and the Automated Cellular Imaging System. BCH sections also consistently exhibited qualitative expression of pancytokeratins, p53, Ki-67, or E-cadherin in cancer cells and that of vimentin or GSTPi in fibroblasts, fibronectin in the basement membrane and collagen IV in the extracellular matrix. The expression of the protein analytes and cellular architecture of BCH were markedly similar to those of breast cancer tissue.

A Review of the Responses of Two- and Three-Dimensional Engineered Tissues to Electric Fields

Science.gov (United States)

Hronik-Tupaj, Marie

2012-01-01

The application of external biophysical signals is one approach to tissue engineering that is explored less often than more traditional additions of exogenous biochemical and chemical factors to direct cell and tissue outcomes. The study of bioelectromagnetism and the field of electrotherapeutics have evolved over the years, and we review biocompatible electric stimulation devices and their successful application to tissue growth. Specifically, information on capacitively coupled alternating current, inductively coupled alternating current, and direct current devices is described. Cell and tissue responses from the application of these devices, including two- and three-dimensional in vitro studies and in vivo studies, are reviewed with regard to cell proliferation, adhesion, differentiation, morphology, and migration and tissue function. The current understanding of cellular mechanisms related to electric stimulation is detailed. The advantages of electric stimulation are compared with those pf other techniques, and areas in which electric fields are used as an adjuvant therapy for healing and regeneration are discussed. PMID:22046979

Plant Tissue Culture

Indian Academy of Sciences (India)

Admin

Plant tissue culture is a technique of culturing plant cells, tissues and organs on ... working methods (Box 2) and discovery of the need for B vita- mins and auxins for ... Kotte (Germany) reported some success with growing isolated root tips.

Poly(N-isopropylacrylamide) hydrogel/chitosan scaffold hybrid for three-dimensional stem cell culture and cartilage tissue engineering.

Science.gov (United States)

Mellati, Amir; Kiamahalleh, Meisam Valizadeh; Madani, S Hadi; Dai, Sheng; Bi, Jingxiu; Jin, Bo; Zhang, Hu

2016-11-01

Providing a controllable and definable three-dimensional (3D) microenvironment for chondrogenic differentiation of mesenchymal stem cells (MSCs) remains a great challenge for cartilage tissue engineering. In this work, poly(N-isopropylacrylamide) (PNIPAAm) polymers with the degrees of polymerization of 100 and 400 (NI100 and NI400) were prepared and the polymer solutions were introduced into the preprepared chitosan porous scaffolds (CS) to form hybrids (CSNI100 and CSNI400, respectively). SEM images indicated that the PNIPAAm gel partially occupied chitosan pores while the interconnected porous structure of chitosan was preserved. MSCs were incorporated within the hybrid and cell proliferation and chondrogenic differentiation were monitored. After 7-day incubation of the cell-laden constructs in a growth medium, the cell viability in CSNI100 and CSNI400 were 54 and 108% higher than that in CS alone, respectively. Glycosaminoglycan and total collagen contents increased 2.6- and 2.5-fold after 28-day culture of cell-laden CSNI400 in the chondrogenic medium. These results suggest that the hybrid structure composed of the chitosan porous scaffold and the well-defined PNIPAAm hydrogel, in particular CSNI400, is suitable for 3D stem cell culture and cartilage tissue engineering. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2764-2774, 2016. © 2016 Wiley Periodicals, Inc.

Optimized Protocol for Protein Extraction from the Breast Tissue that is Compatible with Two-Dimensional Gel Electrophoresis

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Olena Zakharchenko

2011-01-01

Full Text Available Proteomics is a highly informative approach to analyze cancer-associated transformation in tissues. The main challenge to use a tissue for proteomics studies is the small sample size and difficulties to extract and preserve proteins. The choice of a buffer compatible with proteomics applications is also a challenge. Here we describe a protocol optimized for the most efficient extraction of proteins from the human breast tissue in a buffer compatible with two-dimensional gel electrophoresis (2D-GE. This protocol is based on mechanically assisted disintegration of tissues directly in the 2D-GE buffer. Our method is simple, robust and easy to apply in clinical practice. We demonstrate high quality of separation of proteins prepared according to the reported here protocol.

Thicker three-dimensional tissue from a "symbiotic recycling system" combining mammalian cells and algae.

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Haraguchi, Yuji; Kagawa, Yuki; Sakaguchi, Katsuhisa; Matsuura, Katsuhisa; Shimizu, Tatsuya; Okano, Teruo

2017-01-31

In this paper, we report an in vitro co-culture system that combines mammalian cells and algae, Chlorococcum littorale, to create a three-dimensional (3-D) tissue. While the C2C12 mouse myoblasts and rat cardiac cells consumed oxygen actively, intense oxygen production was accounted for by the algae even in the co-culture system. Although cell metabolism within thicker cardiac cell-layered tissues showed anaerobic respiration, the introduction of innovative co-cultivation partially changed the metabolism to aerobic respiration. Moreover, the amount of glucose consumption and lactate production in the cardiac tissues and the amount of ammonia in the culture media decreased significantly when co-cultivated with algae. In the cardiac tissues devoid of algae, delamination was observed histologically, and the release of creatine kinase (CK) from the tissues showed severe cardiac cell damage. On the other hand, the layered cell tissues with algae were observed to be in a good histological condition, with less than one-fifth decline in CK release. The co-cultivation with algae improved the culture condition of the thicker tissues, resulting in the formation of 160 μm-thick cardiac tissues. Thus, the present study proposes the possibility of creating an in vitro "symbiotic recycling system" composed of mammalian cells and algae.

Long-term culture of human liver tissue with advanced hepatic functions.

Science.gov (United States)

Ng, Soon Seng; Xiong, Anming; Nguyen, Khanh; Masek, Marilyn; No, Da Yoon; Elazar, Menashe; Shteyer, Eyal; Winters, Mark A; Voedisch, Amy; Shaw, Kate; Rashid, Sheikh Tamir; Frank, Curtis W; Cho, Nam Joon; Glenn, Jeffrey S

2017-06-02

A major challenge for studying authentic liver cell function and cell replacement therapies is that primary human hepatocytes rapidly lose their advanced function in conventional, 2-dimensional culture platforms. Here, we describe the fabrication of 3-dimensional hexagonally arrayed lobular human liver tissues inspired by the liver's natural architecture. The engineered liver tissues exhibit key features of advanced differentiation, such as human-specific cytochrome P450-mediated drug metabolism and the ability to support efficient infection with patient-derived inoculums of hepatitis C virus. The tissues permit the assessment of antiviral agents and maintain their advanced functions for over 5 months in culture. This extended functionality enabled the prediction of a fatal human-specific hepatotoxicity caused by fialuridine (FIAU), which had escaped detection by preclinical models and short-term clinical studies. The results obtained with the engineered human liver tissue in this study provide proof-of-concept determination of human-specific drug metabolism, demonstrate the ability to support infection with human hepatitis virus derived from an infected patient and subsequent antiviral drug testing against said infection, and facilitate detection of human-specific drug hepatotoxicity associated with late-onset liver failure. Looking forward, the scalability and biocompatibility of the scaffold are also ideal for future cell replacement therapeutic strategies.

Plant tissue culture techniques

Directory of Open Access Journals (Sweden)

Rolf Dieter Illg

1991-01-01

Full Text Available Plant cell and tissue culture in a simple fashion refers to techniques which utilize either single plant cells, groups of unorganized cells (callus or organized tissues or organs put in culture, under controlled sterile conditions.

21 CFR 876.5885 - Tissue culture media for human ex vivo tissue and cell culture processing applications.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Tissue culture media for human ex vivo tissue and cell culture processing applications. 876.5885 Section 876.5885 Food and Drugs FOOD AND DRUG... DEVICES Therapeutic Devices § 876.5885 Tissue culture media for human ex vivo tissue and cell culture...

Development of Three-Dimensional Multicellular Tissue-Like Constructs for Mutational Analysis Using Macroporous Microcarriers

Science.gov (United States)

Jordan, Jacqueline A.; Fraga, Denise N.; Gonda, Steve R.

2002-01-01

A three-dimensional (3-D), tissue-like model was developed for the genotoxic assessment of space environment. In previous experiments, we found that culturing mammalian cells in a NASA-designed bioreactor, using Cytodex-3 beads as a scaffold, generated 3-D multicellular spheroids. In an effort to generate scaffold-free spheroids, we developed a new 3-D tissue-like model by coculturing fibroblast and epithelial cell in a NASA bioreactor using macroporous Cultispher-S(TradeMark) microcarriers. Big Blue(Registered Trademark) Rat 2(Lambda) fibroblasts, genetically engineered to contain multiple copies (>60 copies/cell) of the Lac I target gene, were cocultured with radio-sensitive human epithelial cells, H184F5. Over an 8-day period, samples were periodically examined by microscopy and histology to confirm cell attachment, growth, and viability. Immunohistochemistry and western analysis were used to evaluate the expression of specific cytoskeletal and adhesion proteins. Key cell culture parameters (glucose, pH, and lactate concentrations) were monitored daily. Controls were two-dimensional mono layers of fibroblast or epithelial cells cultured in T-flasks. Analysis of 3-D spheroids from the bioreactor suggests fibroblast cells attached to and completely covered the bead surface and inner channels by day 3 in the bioreactor. Treatment of the 3-day spheroids with dispase II dissolved the Cultisphers(TradeMark) and produced multicellular, bead-less constructs. Immunohistochemistry confirmed the presence of vi.mentin, cytokeratin and E-cadherin in treated spheroids. Examination of the dispase II treated spheroids with transmission electron microscopy (TEM) also showed the presence of desmosomes. These results suggest that the controlled enzymatic degradation of an artificial matrix in the low shear environment of the NASA-designed bioreactor can produce 3-D tissue-like spheroids. 2

Bioprinted three dimensional human tissues for toxicology and disease modeling.

Science.gov (United States)

Nguyen, Deborah G; Pentoney, Stephen L

2017-03-01

The high rate of attrition among clinical-stage therapies, due largely to an inability to predict human toxicity and/or efficacy, underscores the need for in vitro models that better recapitulate in vivo human biology. In much the same way that additive manufacturing has revolutionized the production of solid objects, three-dimensional (3D) bioprinting is enabling the automated production of more architecturally and functionally accurate in vitro tissue culture models. Here, we provide an overview of the most commonly used bioprinting approaches and how they are being used to generate complex in vitro tissues for use in toxicology and disease modeling research. Copyright © 2017 Elsevier Ltd. All rights reserved.

Three-dimensional assessment of brain tissue morphology

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Müller, Bert; Germann, Marco; Jeanmonod, Daniel; Morel, Anne

2006-08-01

The microstructure of brain tissues becomes visible using different types of optical microscopy after the tissue sectioning. This preparation procedure introduces stress and strain in the anisotropic and inhomogeneous soft tissue slices, which are several 10 μm thick. Consequently, the three-dimensional dataset, generated out of the two-dimensional images with lateral submicrometer resolution, needs algorithms to correct the deformations, which can be significant for mellow tissue such as brain segments. The spatial resolution perpendicular to the slices is much worse with respect to the lateral sub-micrometer resolution. Therefore, we propose as complementary method the synchrotron-radiation-based micro computed tomography (SRμCT), which avoids any kind of preparation artifacts due to sectioning and histological processing and yields true micrometer resolution in the three orthogonal directions. The visualization of soft matter by the use of SRμCT, however, is often based on elaborate staining protocols, since the tissue exhibits (almost) the same x-ray absorption as the surrounding medium. Therefore, it is unexpected that human tissue from the pons and the medulla oblongata in phosphate buffer show several features such as the blood vessels and the inferior olivary nucleus without staining. The value of these tomograms lies especially in the precise non-rigid registration of the different sets of histological slices. Applications of this method to larger pieces of brain tissue, such as the human thalamus are planned in the context of stereotactic functional neurosurgery.

Epigenetics in plant tissue culture

NARCIS (Netherlands)

Smulders, M.J.M.; Klerk, de G.J.M.

2011-01-01

Plants produced vegetatively in tissue culture may differ from the plants from which they have been derived. Two major classes of off-types occur: genetic ones and epigenetic ones. This review is about epigenetic aberrations. We discuss recent studies that have uncovered epigenetic modifications at

Thicker three-dimensional tissue from a “symbiotic recycling system” combining mammalian cells and algae

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Haraguchi, Yuji; Kagawa, Yuki; Sakaguchi, Katsuhisa; Matsuura, Katsuhisa; Shimizu, Tatsuya; Okano, Teruo

2017-01-01

In this paper, we report an in vitro co-culture system that combines mammalian cells and algae, Chlorococcum littorale, to create a three-dimensional (3-D) tissue. While the C2C12 mouse myoblasts and rat cardiac cells consumed oxygen actively, intense oxygen production was accounted for by the algae even in the co-culture system. Although cell metabolism within thicker cardiac cell-layered tissues showed anaerobic respiration, the introduction of innovative co-cultivation partially changed the metabolism to aerobic respiration. Moreover, the amount of glucose consumption and lactate production in the cardiac tissues and the amount of ammonia in the culture media decreased significantly when co-cultivated with algae. In the cardiac tissues devoid of algae, delamination was observed histologically, and the release of creatine kinase (CK) from the tissues showed severe cardiac cell damage. On the other hand, the layered cell tissues with algae were observed to be in a good histological condition, with less than one-fifth decline in CK release. The co-cultivation with algae improved the culture condition of the thicker tissues, resulting in the formation of 160 μm-thick cardiac tissues. Thus, the present study proposes the possibility of creating an in vitro “symbiotic recycling system” composed of mammalian cells and algae. PMID:28139713

Mathematical modelling of tissue formation in chondrocyte filter cultures.

Science.gov (United States)

Catt, C J; Schuurman, W; Sengers, B G; van Weeren, P R; Dhert, W J A; Please, C P; Malda, J

2011-12-17

In the field of cartilage tissue engineering, filter cultures are a frequently used three-dimensional differentiation model. However, understanding of the governing processes of in vitro growth and development of tissue in these models is limited. Therefore, this study aimed to further characterise these processes by means of an approach combining both experimental and applied mathematical methods. A mathematical model was constructed, consisting of partial differential equations predicting the distribution of cells and glycosaminoglycans (GAGs), as well as the overall thickness of the tissue. Experimental data was collected to allow comparison with the predictions of the simulation and refinement of the initial models. Healthy mature equine chondrocytes were expanded and subsequently seeded on collagen-coated filters and cultured for up to 7 weeks. Resulting samples were characterised biochemically, as well as histologically. The simulations showed a good representation of the experimentally obtained cell and matrix distribution within the cultures. The mathematical results indicate that the experimental GAG and cell distribution is critically dependent on the rate at which the cell differentiation process takes place, which has important implications for interpreting experimental results. This study demonstrates that large regions of the tissue are inactive in terms of proliferation and growth of the layer. In particular, this would imply that higher seeding densities will not significantly affect the growth rate. A simple mathematical model was developed to predict the observed experimental data and enable interpretation of the principal underlying mechanisms controlling growth-related changes in tissue composition.

Role of cell deformability in the two-dimensional melting of biological tissues

Science.gov (United States)

Li, Yan-Wei; Ciamarra, Massimo Pica

2018-04-01

The size and shape of a large variety of polymeric particles, including biological cells, star polymers, dendrimes, and microgels, depend on the applied stresses as the particles are extremely soft. In high-density suspensions these particles deform as stressed by their neighbors, which implies that the interparticle interaction becomes of many-body type. Investigating a two-dimensional model of cell tissue, where the single particle shear modulus is related to the cell adhesion strength, here we show that the particle deformability affects the melting scenario. On increasing the temperature, stiff particles undergo a first-order solid/liquid transition, while soft ones undergo a continuous solid/hexatic transition followed by a discontinuous hexatic/liquid transition. At zero temperature the melting transition driven by the decrease of the adhesion strength occurs through two continuous transitions as in the Kosterlitz, Thouless, Halperin, Nelson, and Young scenario. Thus, there is a range of adhesion strength values where the hexatic phase is stable at zero temperature, which suggests that the intermediate phase of the epithelial-to-mesenchymal transition could be hexatic type.

Proteomic analysis reveals the mechanisms of Mycena dendrobii promoting transplantation survival and growth of tissue culture seedlings of Dendrobium officinale.

Science.gov (United States)

Xu, X B; Ma, X Y; Lei, H H; Song, H M; Ying, Q C; Xu, M J; Liu, S B; Wang, H Z

2015-06-01

Dendrobium officinale is an important traditional Chinese medicinal herb. Its seedlings generally show low survival and growth when transferred from in vitro tissue culture to a greenhouse or field environment. In this study, the effect of Mycena dendrobii on the survival and growth of D. officinale tissue culture seedlings and the mechanisms involved was explored. Mycena dendrobii were applied underneath the roots of D. officinale tissue culture seedlings. The seedling survival and growth were analysed. The root proteins induced by M. dendrobii were identified using two-dimensional (2-D) electrophoresis and matrix-assisted laser desorption/ionization time-of-flight MS (MALDI-TOF-MS). Mycena dendrobii treatment significantly enhanced survival and growth of D. officinale seedlings. Forty-one proteins induced by M. dendrobii were identified. Among them, 10 were involved in defence and stress response, two were involved in the formation of root or mycorrhizae, and three were related to the biosynthesis of bioactive constituents. These results suggest that enhancing stress tolerance and promoting new root formation induced by M. dendrobii may improve the survival and growth of D. officinale tissue culture seedlings. This study provides a foundation for future use of M. dendrobii in the large-scale cultivation of Dendrobiums. © 2015 The Society for Applied Microbiology.

Three-Dimensional Culture Model of Skeletal Muscle Tissue with Atrophy Induced by Dexamethasone.

Science.gov (United States)

Shimizu, Kazunori; Genma, Riho; Gotou, Yuuki; Nagasaka, Sumire; Honda, Hiroyuki

2017-06-15

Drug screening systems for muscle atrophy based on the contractile force of cultured skeletal muscle tissues are required for the development of preventive or therapeutic drugs for atrophy. This study aims to develop a muscle atrophy model by inducing atrophy in normal muscle tissues constructed on microdevices capable of measuring the contractile force and to verify if this model is suitable for drug screening using the contractile force as an index. Tissue engineered skeletal muscles containing striated myotubes were prepared on the microdevices for the study. The addition of 100 µM dexamethasone (Dex), which is used as a muscle atrophy inducer, for 24 h reduced the contractile force significantly. An increase in the expression of Atrogin-1 and MuRF-1 in the tissues treated with Dex was established. A decrease in the number of striated myotubes was also observed in the tissues treated with Dex. Treatment with 8 ng/mL Insulin-like Growth Factor (IGF-I) for 24 h significantly increased the contractile force of the Dex-induced atrophic tissues. The same treatment, though, had no impact on the force of the normal tissues. Thus, it is envisaged that the atrophic skeletal muscle tissues induced by Dex can be used for drug screening against atrophy.

The use of total human bone marrow fraction in a direct three-dimensional expansion approach for bone tissue engineering applications: focus on angiogenesis and osteogenesis.

Science.gov (United States)

Guerrero, Julien; Oliveira, Hugo; Catros, Sylvain; Siadous, Robin; Derkaoui, Sidi-Mohammed; Bareille, Reine; Letourneur, Didier; Amédée, Joëlle

2015-03-01

Current approaches in bone tissue engineering have shown limited success, mostly owing to insufficient vascularization of the construct. A common approach consists of co-culture of endothelial cells and osteoblastic cells. This strategy uses cells from different sources and differentiation states, thus increasing the complexity upstream of a clinical application. The source of reparative cells is paramount for the success of bone tissue engineering applications. In this context, stem cells obtained from human bone marrow hold much promise. Here, we analyzed the potential of human whole bone marrow cells directly expanded in a three-dimensional (3D) polymer matrix and focused on the further characterization of this heterogeneous population and on their ability to promote angiogenesis and osteogenesis, both in vitro and in vivo, in a subcutaneous model. Cellular aggregates were formed within 24 h and over the 12-day culture period expressed endothelial and bone-specific markers and a specific junctional protein. Ectopic implantation of the tissue-engineered constructs revealed osteoid tissue and vessel formation both at the periphery and within the implant. This work sheds light on the potential clinical use of human whole bone marrow for bone regeneration strategies, focusing on a simplified approach to develop a direct 3D culture without two-dimensional isolation or expansion.

Cell culture for three-dimensional modeling in rotating-wall vessels: an application of simulated microgravity

Science.gov (United States)

Schwarz, R. P.; Goodwin, T. J.; Wolf, D. A.

1992-01-01

High-density, three-dimensional cell cultures are difficult to grow in vitro. The rotating-wall vessel (RWV) described here has cultured BHK-21 cells to a density of 1.1 X 10(7) cells/ml. Cells on microcarriers were observed to grow with enhanced bridging in this batch culture system. The RWV is a horizontally rotated tissue culture vessel with silicon membrane oxygenation. This design results in a low-turbulence, low-shear cell culture environment with abundant oxygenation. The RWV has the potential to culture a wide variety of normal and neoplastic cells.

Three-dimensional culture conditions lead to decreased radiation induced cytotoxicity in human mammary epithelial cells

International Nuclear Information System (INIS)

Sowa, Marianne B.; Chrisler, William B.; Zens, Kyra D.; Ashjian, Emily J.; Opresko, Lee K.

2010-01-01

For both targeted and non-targeted exposures, the cellular responses to ionizing radiation have predominantly been measured in two-dimensional monolayer cultures. Although convenient for biochemical analysis, the true interactions in vivo depend upon complex interactions between cells themselves and the surrounding extracellular matrix. This study directly compares the influence of culture conditions on radiation induced cytotoxicity following exposure to low-LET ionizing radiation. Using a three-dimensional (3D) human mammary epithelial tissue model, we have found a protective effect of 3D cell culture on cell survival after irradiation. The initial state of the cells (i.e., 2D versus 3D culture) at the time of irradiation does not alter survival, nor does the presence of extracellular matrix during and after exposure to dose, but long term culture in 3D which offers significant reduction in cytotoxicity at a given dose (e.g. ∼4-fold increased survival at 5 Gy). The cell cycle delay induced following exposure to 2 and 5 Gy was almost identical between 2D and 3D culture conditions and cannot account for the observed differences in radiation responses. However the amount of apoptosis following radiation exposure is significantly decreased in 3D culture relative to the 2D monolayer after the same dose. A likely mechanism of the cytoprotective effect afforded by 3D culture conditions is the down regulation of radiation induced apoptosis in 3D structures.

Upregulated epidermal growth factor receptor expression following near-infrared irradiation simulating solar radiation in a three-dimensional reconstructed human corneal epithelial tissue culture model.

Science.gov (United States)

Tanaka, Yohei; Nakayama, Jun

2016-01-01

Humans are increasingly exposed to near-infrared (NIR) radiation from both natural (eg, solar) and artificial (eg, electrical appliances) sources. Although the biological effects of sun and ultraviolet (UV) exposure have been extensively investigated, the biological effect of NIR radiation is still unclear. We previously reported that NIR as well as UV induces photoaging and standard UV-blocking materials, such as sunglasses, do not sufficiently block NIR. The objective of this study was to investigate changes in gene expression in three-dimensional reconstructed corneal epithelial tissue culture exposed to broad-spectrum NIR irradiation to simulate solar NIR radiation that reaches human tissues. DNA microarray and quantitative real-time polymerase chain reaction analysis were used to assess gene expression levels in a three-dimensional reconstructed corneal epithelial model composed of normal human corneal epithelial cells exposed to water-filtered broad-spectrum NIR irradiation with a contact cooling (20°C). The water-filter allowed 1,000-1,800 nm wavelengths and excluded 1,400-1,500 nm wavelengths. A DNA microarray with >62,000 different probes showed 25 and 150 genes that were up- or downregulated by at least fourfold and twofold, respectively, after NIR irradiation. In particular, epidermal growth factor receptor (EGFR) was upregulated by 19.4-fold relative to control cells. Quantitative real-time polymerase chain reaction analysis revealed that two variants of EGFR in human corneal epithelial tissue were also significantly upregulated after five rounds of 10 J/cm(2) irradiation (Psolar energy reaching the Earth is in the NIR region, which cannot be adequately blocked by eyewear and thus can induce eye damage with intensive or long-term exposure, protection from both UV and NIR radiation may prevent changes in gene expression and in turn eye damage.

Rapid fabrication of detachable three-dimensional tissues by layering of cell sheets with heating centrifuge.

Science.gov (United States)

Haraguchi, Yuji; Kagawa, Yuki; Hasegawa, Akiyuki; Kubo, Hirotsugu; Shimizu, Tatsuya

2018-01-18

Confluent cultured cells on a temperature-responsive culture dish can be harvested as an intact cell sheet by decreasing temperature below 32°C. A three-dimensional (3-D) tissue can be fabricated by the layering of cell sheets. A resulting 3-D multilayered cell sheet-tissue on a temperature-responsive culture dish can be also harvested without any damage by only temperature decreasing. For shortening the fabrication time of the 3-D multilayered constructs, we attempted to layer cell sheets on a temperature-responsive culture dish with centrifugation. However, when a cell sheet was attached to the culture surface with a conventional centrifuge at 22-23°C, the cell sheet hardly adhere to the surface due to its noncell adhesiveness. Therefore, in this study, we have developed a heating centrifuge. In centrifugation (55g) at 36-37°C, the cell sheet adhered tightly within 5 min to the dish without significant cell damage. Additionally, centrifugation accelerated the cell sheet-layering process. The heating centrifugation shortened the fabrication time by one-fifth compared to a multilayer tissue fabrication without centrifugation. Furthermore, the multilayered constructs were finally detached from the dishes by decreasing temperature. This rapid tissue-fabrication method will be used as a valuable tool in the field of tissue engineering and regenerative therapy. © 2018 American Institute of Chemical Engineers Biotechnol. Prog., 2018. © 2018 American Institute of Chemical Engineers.

Efficient extraction of proteins from recalcitrant plant tissue for subsequent analysis by two-dimensional gel electrophoresis.

Science.gov (United States)

Parkhey, Suruchi; Chandrakar, Vibhuti; Naithani, S C; Keshavkant, S

2015-10-01

Protein extraction for two-dimensional electrophoresis from tissues of recalcitrant species is quite problematic and challenging due to the low protein content and high abundance of contaminants. Proteomics in Shorea robusta is scarcely conducted due to the lack of a suitable protein preparation procedure. To establish an effective protein extraction protocol suitable for two-dimensional electrophoresis in Shorea robusta, four procedures (borate buffer/trichloroacetic acid extraction, organic solvent/trichloroacetic acid precipitation, sucrose/Tris/phenol, and organic solvent/phenol/sodium dodecyl sulfate) were evaluated. Following these, proteins were isolated from mature leaves and were analyzed for proteomics, and also for potential contaminants, widely reported to hinder proteomics. The borate buffer/trichloroacetic acid extraction had the lowest protein yield and did not result in any banding even in one-dimensional electrophoresis. In contrast, organic solvent/phenol/sodium dodecyl sulfate extraction allowed the highest protein yield. Moreover, during proteomics, organic solvent/phenol/sodium dodecyl sulfate extracted protein resolved the maximum number (144) of spots. Further, when proteins were evaluated for contaminants, significant (77-95%) reductions in the nucleic acids, phenol, and sugars were discernible with refinement in extraction procedure. Accumulated data suggested that the organic solvent/phenol/sodium dodecyl sulfate extraction was the most effective protocol for protein isolation for proteomics of Shorea robusta and can be used for plants that have a similar set of contaminants. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Advanced three-dimensional culture of equine intestinal epithelial stem cells.

Science.gov (United States)

Stewart, A Stieler; Freund, J M; Gonzalez, L M

2018-03-01

Intestinal epithelial stem cells are critical to epithelial repair following gastrointestinal injury. The culture of intestinal stem cells has quickly become a cornerstone of a vast number of new research endeavours that range from determining tissue viability to testing drug efficacy for humans. This study aims to describe the methods of equine stem cell culture and highlights the future benefits of these techniques for the advancement of equine medicine. To describe the isolation and culture of small intestinal stem cells into three-dimensional (3D) enteroids in horses without clinical gastrointestinal abnormalities. Descriptive study. Intestinal samples were collected by sharp dissection immediately after euthanasia. Intestinal crypts containing intestinal stem cells were dissociated from the underlying tissue layers, plated in a 3D matrix and supplemented with growth factors. After several days, resultant 3D enteroids were prepared for immunofluorescent imaging and polymerase chain reaction (PCR) analysis to detect and characterise specific cell types present. Intestinal crypts were cryopreserved immediately following collection and viability assessed. Intestinal crypts were successfully cultured and matured into 3D enteroids containing a lumen and budding structures. Immunofluorescence and PCR were used to confirm the existence of stem cells and all post mitotic, mature cell types, described to exist in the horse intestinal epithelium. Previously frozen crypts were successfully cultured following a freeze-thaw cycle. Tissues were all derived from normal horses. Application of this technique for the study of specific disease was not performed at this time. The successful culture of equine intestinal crypts into 3D "mini-guts" allows for in vitro studies of the equine intestine. Additionally, these results have relevance to future development of novel therapies that harness the regenerative potential of equine intestine in horses with gastrointestinal disease

Numerical simulation of fluid field and in vitro three-dimensional fabrication of tissue-engineered bones in a rotating bioreactor and in vivo implantation for repairing segmental bone defects.

Science.gov (United States)

Song, Kedong; Wang, Hai; Zhang, Bowen; Lim, Mayasari; Liu, Yingchao; Liu, Tianqing

2013-03-01

In this paper, two-dimensional flow field simulation was conducted to determine shear stresses and velocity profiles for bone tissue engineering in a rotating wall vessel bioreactor (RWVB). In addition, in vitro three-dimensional fabrication of tissue-engineered bones was carried out in optimized bioreactor conditions, and in vivo implantation using fabricated bones was performed for segmental bone defects of Zelanian rabbits. The distribution of dynamic pressure, total pressure, shear stress, and velocity within the culture chamber was calculated for different scaffold locations. According to the simulation results, the dynamic pressure, velocity, and shear stress around the surface of cell-scaffold construction periodically changed at different locations of the RWVB, which could result in periodical stress stimulation for fabricated tissue constructs. However, overall shear stresses were relatively low, and the fluid velocities were uniform in the bioreactor. Our in vitro experiments showed that the number of cells cultured in the RWVB was five times higher than those cultured in a T-flask. The tissue-engineered bones grew very well in the RWVB. This study demonstrates that stress stimulation in an RWVB can be beneficial for cell/bio-derived bone constructs fabricated in an RWVB, with an application for repairing segmental bone defects.

The plant tissue culture

International Nuclear Information System (INIS)

Crocomo, O.J.; Sharp, W.R.

1973-01-01

Progress in the field of plant tissue culture at the Plant Biochemistry Sector, Centro de Energia na Agricultura (CENA), Piracicaba, S.P., Brazil, pertains to the simplification of development in 'Phaseolus vulgaris' by dividing the organism into its component organs, tissues, and cells and the maintenance of these components on defined culture media 'in vitro'. This achievement has set the stage for probing the basis for the stability of the differentiated states and/or the reentry of mature differentiated cells into the mitotic cell cycle and their subsequent redifferentiation. Data from such studies at the cytological and biochemical level have been invaluable in the elucidation of the control mechanisms responsible for expression of the cellular phenotype. Unlimited possibilities exist for the application of tissue culture in the vegetative propagation of 'Phaseolus' and other important cultivars in providing genocopies or a large scale and/or readily obtaining plantlets from haploid cell lines or from protoplast (wall-less cells) hybridization products following genetic manipulation. These tools are being applied in this laboratory for the development and selection of high protein synthesizing 'Phaseolus' cultivars

Three-dimensional CT imaging of soft-tissue anatomy

International Nuclear Information System (INIS)

Fishman, E.K.; Ney, D.R.; Magid, D.; Kuhlman, J.E.

1988-01-01

Three-dimensional display of computed tomographic data has been limited to skeletal structures. This was in part related to the reconstruction algorithm used, which relied on a binary classification scheme. A new algorithm, volumetric rendering with percentage classification, provides the ability to display three-dimensional images of muscle and soft tissue. A review was conducted of images in 35 cases in which muscle and/or soft tissue were part of the clinical problem. In all cases, individual muscle groups could be clearly identified and discriminated. Branching vessels in the range of 2.3 mm could be identified. Similarly, lymph nodes could be clearly defined. High-resolution three-dimensional images were found to be useful both in providing an increased understanding of complex muscle and soft tissue anatomy and in surgical planning

Establishment of primary keratinocyte culture from horse tissue biopsates

Directory of Open Access Journals (Sweden)

Jernej OGOREVC

2015-12-01

Full Text Available Primary cell lines established from skin tissue can be used in immunological, proteomic and genomic studies as in vitro skin models. The goal of our study was to establish a primary keratinocyte cell culture from tissue biopsates of two horses. The primary keratinocyte cell culture was obtained by mechanical and enzymatic dissociation and with explant culture method. The result was a heterogeneous primary culture comprised of keratinocytes and fibroblasts. To distinguish epithelial and mesenchymal cells immunofluorescent characterisation was performed, using antibodies against cytokeratin 14 and vimentin. We successfully at attained a primary cell line of keratinocytes, which could potentially be used to study equine skin diseases, as an animal model for human diseases, and for cosmetic and therapeutic product testing.

Microfluidic engineered high cell density three-dimensional neural cultures

Science.gov (United States)

Cullen, D. Kacy; Vukasinovic, Jelena; Glezer, Ari; La Placa, Michelle C.

2007-06-01

Three-dimensional (3D) neural cultures with cells distributed throughout a thick, bioactive protein scaffold may better represent neurobiological phenomena than planar correlates lacking matrix support. Neural cells in vivo interact within a complex, multicellular environment with tightly coupled 3D cell-cell/cell-matrix interactions; however, thick 3D neural cultures at cell densities approaching that of brain rapidly decay, presumably due to diffusion limited interstitial mass transport. To address this issue, we have developed a novel perfusion platform that utilizes forced intercellular convection to enhance mass transport. First, we demonstrated that in thick (>500 µm) 3D neural cultures supported by passive diffusion, cell densities =104 cells mm-3), continuous medium perfusion at 2.0-11.0 µL min-1 improved viability compared to non-perfused cultures (p death and matrix degradation. In perfused cultures, survival was dependent on proximity to the perfusion source at 2.00-6.25 µL min-1 (p 90% viability in both neuronal cultures and neuronal-astrocytic co-cultures. This work demonstrates the utility of forced interstitial convection in improving the survival of high cell density 3D engineered neural constructs and may aid in the development of novel tissue-engineered systems reconstituting 3D cell-cell/cell-matrix interactions.

Magnetic resonance imaging-three-dimensional printing technology fabricates customized scaffolds for brain tissue engineering

Institute of Scientific and Technical Information of China (English)

Feng Fu; Chong Chen; Sai Zhang; Ming-liang Zhao; Xiao-hong Li; Zhe Qin; Chao Xu; Xu-yi Chen; Rui-xin Li; Li-na Wang; Ding-wei Peng; Hong-tao Sun; Yue Tu

2017-01-01

Conventional fabrication methods lack the ability to control both macro- and micro-structures of generated scaffolds. Three-dimensional printing is a solid free-form fabrication method that provides novel ways to create customized scaffolds with high precision and accuracy. In this study, an electrically controlled cortical impactor was used to induce randomized brain tissue defects. The overall shape of scaffolds was designed using rat-specific anatomical data obtained from magnetic resonance imaging, and the internal structure was created by computer- aided design. As the result of limitations arising from insufficient resolution of the manufacturing process, we magnified the size of the cavity model prototype five-fold to successfully fabricate customized collagen-chitosan scaffolds using three-dimensional printing. Results demonstrated that scaffolds have three-dimensional porous structures, high porosity, highly specific surface areas, pore connectivity and good internal characteristics. Neural stem cells co-cultured with scaffolds showed good viability, indicating good biocompatibility and biodegradability. This technique may be a promising new strategy for regenerating complex damaged brain tissues, and helps pave the way toward personalized medicine.

Challenges in Bio-fabrication of Organoid Cultures.

Science.gov (United States)

Peng, Weijie; Datta, Pallab; Wu, Yang; Dey, Madhuri; Ayan, Bugra; Dababneh, Amer; Ozbolat, Ibrahim T

2018-06-01

Three-dimensional (3D) organoids have shown advantages in cell culture over traditional two-dimensional (2D) culture, and have great potential in various applications of tissue engineering. However, there are limitations in current organoid fabrication technologies, such as uncontrolled size, poor reproductively, and inadequate complexity of organoids. In this chapter, we present the existing techniques and discuss the major challenges for 3D organoid biofabrication. Future perspectives on organoid bioprinting are also discussed, where bioprinting technologies are expected to make a major contribution in organoid fabrication, such as realizing mass production and constructing complex heterotypic tissues, and thus further advance the translational application of organoids in tissue engineering and regenerative medicine as well drug testing and pharmaceutics.

Laboratory Workflow Analysis of Culture of Periprosthetic Tissues in Blood Culture Bottles.

Science.gov (United States)

Peel, Trisha N; Sedarski, John A; Dylla, Brenda L; Shannon, Samantha K; Amirahmadi, Fazlollaah; Hughes, John G; Cheng, Allen C; Patel, Robin

2017-09-01

Culture of periprosthetic tissue specimens in blood culture bottles is more sensitive than conventional techniques, but the impact on laboratory workflow has yet to be addressed. Herein, we examined the impact of culture of periprosthetic tissues in blood culture bottles on laboratory workflow and cost. The workflow was process mapped, decision tree models were constructed using probabilities of positive and negative cultures drawn from our published study (T. N. Peel, B. L. Dylla, J. G. Hughes, D. T. Lynch, K. E. Greenwood-Quaintance, A. C. Cheng, J. N. Mandrekar, and R. Patel, mBio 7:e01776-15, 2016, https://doi.org/10.1128/mBio.01776-15), and the processing times and resource costs from the laboratory staff time viewpoint were used to compare periprosthetic tissues culture processes using conventional techniques with culture in blood culture bottles. Sensitivity analysis was performed using various rates of positive cultures. Annualized labor savings were estimated based on salary costs from the U.S. Labor Bureau for Laboratory staff. The model demonstrated a 60.1% reduction in mean total staff time with the adoption of tissue inoculation into blood culture bottles compared to conventional techniques (mean ± standard deviation, 30.7 ± 27.6 versus 77.0 ± 35.3 h per month, respectively; P < 0.001). The estimated annualized labor cost savings of culture using blood culture bottles was $10,876.83 (±$337.16). Sensitivity analysis was performed using various rates of culture positivity (5 to 50%). Culture in blood culture bottles was cost-effective, based on the estimated labor cost savings of $2,132.71 for each percent increase in test accuracy. In conclusion, culture of periprosthetic tissue in blood culture bottles is not only more accurate than but is also cost-saving compared to conventional culture methods. Copyright © 2017 American Society for Microbiology.

TCUP: A novel hAT transposon active in maize tissue culture

Directory of Open Access Journals (Sweden)

Alan eSmith

2012-01-01

Full Text Available Transposable elements are capable of inducing heritable de novo genetic variation. The sequences capable of reactivation, and environmental factors that induce mobilization, remain poorly defined even in well-studied genomes such as maize. We treated maize tissue culture with the demethylating agent 5-aza-2-deoxcytidine and examined long-term tissue culture lines to discover silenced transposable elements that have the potential to induce heritable genetic variation. Through these screens we have identified a novel low copy number hAT transposon, Tissue Culture Up-Regulated (TCUP, which is transcribed at high levels in long-term maize Black Mexican Sweet (BMS tissue culture and up-regulated in response to treatment with 5-aza-2-deoxycytidine. Analysis of the TIGR Maize Gene Index revealed that this element is the most frequently represented EST from the BMS cell culture library and is not represented in other tissue libraries, which is the basis for its name. A full-length sequence was assembled in inbred B73 that contains the putative functional motifs required for autonomous movement of a hAT transposon. Transposon display detected movement of TCUP in two long-term tissue cultured cell lines of the genotype Hi-II AxB and BMS. This research implicates TCUP as a transposon that is capable of reactivation and which may also be particularly sensitive to the stress of the tissue culture environment. Our findings are consistent with the hypothesis that epigenetic alterations potentiate genomic responses to stress during clonal propagation of plants.

Comparative two-dimensional gel analysis and microsequencing identifies gelsolin as one of the most prominent downregulated markers of transformed human fibroblast and epithelial cells

DEFF Research Database (Denmark)

Vandekerckhove, J; Bauw, G; Vancompernolle, K

1990-01-01

A systematic comparison of the protein synthesis patterns of cultured normal and transformed human fibroblasts and epithelial cells, using two-dimensional gel protein analysis combined with computerized imaging and data acquisition, identified a 90-kD protein (SSP 5714) as one of the most striking...... downregulated markers typical of the transformed state. Using the information stored in the comprehensive human cellular protein database, we found this protein strongly expressed in several fetal tissues and one of them, epidermis, served as a source for preparative two-dimensional gel electrophoresis. Partial...... and by coelectrophoresis with purified human gelsolin. These results suggest that an important regulatory protein of the microfilament system may play a role in defining the phenotype of transformed human fibroblast and epithelial cells in culture. Udgivelsesdato: 1990-Jul...

Comparative two-dimensional gel analysis and microsequencing identifies gelsolin as one of the most prominent downregulated markers of transformed human fibroblast and epithelial cells

DEFF Research Database (Denmark)

Vandekerckhove, J; Bauw, G; Vancompernolle, K

1990-01-01

downregulated markers typical of the transformed state. Using the information stored in the comprehensive human cellular protein database, we found this protein strongly expressed in several fetal tissues and one of them, epidermis, served as a source for preparative two-dimensional gel electrophoresis. Partial......A systematic comparison of the protein synthesis patterns of cultured normal and transformed human fibroblasts and epithelial cells, using two-dimensional gel protein analysis combined with computerized imaging and data acquisition, identified a 90-kD protein (SSP 5714) as one of the most striking...... and by coelectrophoresis with purified human gelsolin. These results suggest that an important regulatory protein of the microfilament system may play a role in defining the phenotype of transformed human fibroblast and epithelial cells in culture. Udgivelsesdato: 1990-Jul...

A three-dimensional cell culture model to study the mechano-biological behavior in periodontal ligament regeneration

NARCIS (Netherlands)

Oortgiesen, D.A.W.; Yu, N.; Bronckers, A.L.J.J.; Yang, F.; Walboomers, X.F.; Jansen, J.A.

2012-01-01

Periodontitis is a disease affecting the supporting structures of the teeth, which can eventually result in tooth loss. A three-dimensional (3D) tissue culture model was developed that may serve to grow a 3D construct that not only transplants into defective periodontal sites, but also allows to

Progress in planta transformation without tissue culture

International Nuclear Information System (INIS)

Gu Yunhong; Chinese Academy of Sciences, Hefei; Qin Guangyong; Huo Yuping; Yu Zengliang

2004-01-01

With the development of planta genetic engineering, more emphases have been laid on convenient and high efficient genetic transformation methods. And transformation without tissue culture is a prospective direction of it. In this paper, traditional transformation methods and the methods of non-tissue culture were summarized. With the exploration and application of Arabidopsis transformation mechanism, with the use of ion beam-mediated transformation invented by Chinese scientists and the development of other transformation methods, transformation methods without tissue culture and planta genetic engineering could be improved rapidly. (authors)

Improved Cell Culture Method for Growing Contracting Skeletal Muscle Models

Science.gov (United States)

Marquette, Michele L.; Sognier, Marguerite A.

2013-01-01

An improved method for culturing immature muscle cells (myoblasts) into a mature skeletal muscle overcomes some of the notable limitations of prior culture methods. The development of the method is a major advance in tissue engineering in that, for the first time, a cell-based model spontaneously fuses and differentiates into masses of highly aligned, contracting myotubes. This method enables (1) the construction of improved two-dimensional (monolayer) skeletal muscle test beds; (2) development of contracting three-dimensional tissue models; and (3) improved transplantable tissues for biomedical and regenerative medicine applications. With adaptation, this method also offers potential application for production of other tissue types (i.e., bone and cardiac) from corresponding precursor cells.

Generation of Functional Thyroid Tissue Using 3D-Based Culture of Embryonic Stem Cells.

Science.gov (United States)

Antonica, Francesco; Kasprzyk, Dominika Figini; Schiavo, Andrea Alex; Romitti, Mírian; Costagliola, Sabine

2017-01-01

During the last decade three-dimensional (3D) cultures of pluripotent stem cells have been intensively used to understand morphogenesis and molecular signaling important for the embryonic development of many tissues. In addition, pluripotent stem cells have been shown to be a valid tool for the in vitro modeling of several congenital or chronic human diseases, opening new possibilities to study their physiopathology without using animal models. Even more interestingly, 3D culture has proved to be a powerful and versatile tool to successfully generate functional tissues ex vivo. Using similar approaches, we here describe a protocol for the generation of functional thyroid tissue using mouse embryonic stem cells and give all the details and references for its characterization and analysis both in vitro and in vivo. This model is a valid approach to study the expression and the function of genes involved in the correct morphogenesis of thyroid gland, to elucidate the mechanisms of production and secretion of thyroid hormones and to test anti-thyroid drugs.

Effect of lunar materials on plant tissue culture.

Science.gov (United States)

Walkinshaw, C. H.; Venketeswaran, S.; Baur, P. S.; Croley, T. E.; Scholes, V. E.; Weete, J. D.; Halliwell, R. S.; Hall, R. H.

1973-01-01

Lunar material collected during the Apollo 11, 12, 14, and 15 missions has been used to treat 12 species of higher plant tissue cultures. Biochemical and morphological studies have been conducted on several of these species. Tobacco tissue cultures treated with 0.22 g of lunar material exhibited increased greening more complex chloroplasts, less cytoplasmic vacuolation and greater vesiculation. Pine tissue cultures reacted to treatment by an increased deposition of tannin-like materials. The percentage of dry weight and soluble protein was increased in cultures treated with either lunar or terrestrial rock materials.

Biomaterials in co-culture systems: towards optimizing tissue integration and cell signaling within scaffolds.

Science.gov (United States)

Battiston, Kyle G; Cheung, Jane W C; Jain, Devika; Santerre, J Paul

2014-05-01

Most natural tissues consist of multi-cellular systems made up of two or more cell types. However, some of these tissues may not regenerate themselves following tissue injury or disease without some form of intervention, such as from the use of tissue engineered constructs. Recent studies have increasingly used co-cultures in tissue engineering applications as these systems better model the natural tissues, both physically and biologically. This review aims to identify the challenges of using co-culture systems and to highlight different approaches with respect to the use of biomaterials in the use of such systems. The application of co-culture systems to stimulate a desired biological response and examples of studies within particular tissue engineering disciplines are summarized. A description of different analytical co-culture systems is also discussed and the role of biomaterials in the future of co-culture research are elaborated on. Understanding the complex cell-cell and cell-biomaterial interactions involved in co-culture systems will ultimately lead the field towards biomaterial concepts and designs with specific biochemical, electrical, and mechanical characteristics that are tailored towards the needs of distinct co-culture systems. Copyright © 2014 Elsevier Ltd. All rights reserved.

Two-dimensional errors

International Nuclear Information System (INIS)

Anon.

1991-01-01

This chapter addresses the extension of previous work in one-dimensional (linear) error theory to two-dimensional error analysis. The topics of the chapter include the definition of two-dimensional error, the probability ellipse, the probability circle, elliptical (circular) error evaluation, the application to position accuracy, and the use of control systems (points) in measurements

Renal cell carcinoma primary cultures maintain genomic and phenotypic profile of parental tumor tissues

International Nuclear Information System (INIS)

Cifola, Ingrid; Magni, Fulvio; Signorini, Stefano; Battaglia, Cristina; Perego, Roberto A; Bianchi, Cristina; Mangano, Eleonora; Bombelli, Silvia; Frascati, Fabio; Fasoli, Ester; Ferrero, Stefano; Di Stefano, Vitalba; Zipeto, Maria A

2011-01-01

Clear cell renal cell carcinoma (ccRCC) is characterized by recurrent copy number alterations (CNAs) and loss of heterozygosity (LOH), which may have potential diagnostic and prognostic applications. Here, we explored whether ccRCC primary cultures, established from surgical tumor specimens, maintain the DNA profile of parental tumor tissues allowing a more confident CNAs and LOH discrimination with respect to the original tissues. We established a collection of 9 phenotypically well-characterized ccRCC primary cell cultures. Using the Affymetrix SNP array technology, we performed the genome-wide copy number (CN) profiling of both cultures and corresponding tumor tissues. Global concordance for each culture/tissue pair was assayed evaluating the correlations between whole-genome CN profiles and SNP allelic calls. CN analysis was performed using the two CNAG v3.0 and Partek software, and comparing results returned by two different algorithms (Hidden Markov Model and Genomic Segmentation). A very good overlap between the CNAs of each culture and corresponding tissue was observed. The finding, reinforced by high whole-genome CN correlations and SNP call concordances, provided evidence that each culture was derived from its corresponding tissue and maintained the genomic alterations of parental tumor. In addition, primary culture DNA profile remained stable for at least 3 weeks, till to third passage. These cultures showed a greater cell homogeneity and enrichment in tumor component than original tissues, thus enabling a better discrimination of CNAs and LOH. Especially for hemizygous deletions, primary cultures presented more evident CN losses, typically accompanied by LOH; differently, in original tissues the intensity of these deletions was weaken by normal cell contamination and LOH calls were missed. ccRCC primary cultures are a reliable in vitro model, well-reproducing original tumor genetics and phenotype, potentially useful for future functional approaches

Preparation of wholemount mouse intestine for high-resolution three-dimensional imaging using two-photon microscopy.

Science.gov (United States)

Appleton, P L; Quyn, A J; Swift, S; Näthke, I

2009-05-01

Visualizing overall tissue architecture in three dimensions is fundamental for validating and integrating biochemical, cell biological and visual data from less complex systems such as cultured cells. Here, we describe a method to generate high-resolution three-dimensional image data of intact mouse gut tissue. Regions of highest interest lie between 50 and 200 mum within this tissue. The quality and usefulness of three-dimensional image data of tissue with such depth is limited owing to problems associated with scattered light, photobleaching and spherical aberration. Furthermore, the highest-quality oil-immersion lenses are designed to work at a maximum distance of image at high-resolution deep within tissue. We show that manipulating the refractive index of the mounting media and decreasing sample opacity greatly improves image quality such that the limiting factor for a standard, inverted multi-photon microscope is determined by the working distance of the objective as opposed to detectable fluorescence. This method negates the need for mechanical sectioning of tissue and enables the routine generation of high-quality, quantitative image data that can significantly advance our understanding of tissue architecture and physiology.

Microfluidic systems for stem cell-based neural tissue engineering.

Science.gov (United States)

Karimi, Mahdi; Bahrami, Sajad; Mirshekari, Hamed; Basri, Seyed Masoud Moosavi; Nik, Amirala Bakhshian; Aref, Amir R; Akbari, Mohsen; Hamblin, Michael R

2016-07-05

Neural tissue engineering aims at developing novel approaches for the treatment of diseases of the nervous system, by providing a permissive environment for the growth and differentiation of neural cells. Three-dimensional (3D) cell culture systems provide a closer biomimetic environment, and promote better cell differentiation and improved cell function, than could be achieved by conventional two-dimensional (2D) culture systems. With the recent advances in the discovery and introduction of different types of stem cells for tissue engineering, microfluidic platforms have provided an improved microenvironment for the 3D-culture of stem cells. Microfluidic systems can provide more precise control over the spatiotemporal distribution of chemical and physical cues at the cellular level compared to traditional systems. Various microsystems have been designed and fabricated for the purpose of neural tissue engineering. Enhanced neural migration and differentiation, and monitoring of these processes, as well as understanding the behavior of stem cells and their microenvironment have been obtained through application of different microfluidic-based stem cell culture and tissue engineering techniques. As the technology advances it may be possible to construct a "brain-on-a-chip". In this review, we describe the basics of stem cells and tissue engineering as well as microfluidics-based tissue engineering approaches. We review recent testing of various microfluidic approaches for stem cell-based neural tissue engineering.

Smallholder adoption and economic impacts of tissue culture ...

African Journals Online (AJOL)

This study was conducted with an objective of determining the correlates of adoption of tissue culture banana technology and its impacts on household incomes in Kenya. The results show that while some households have opted not to adopt tissue culture banana biotechnology, almost all the adopters are growing tissue ...

Walnut tissue culture: research and field applications

Science.gov (United States)

2004-01-01

Vitrotech Biotecnologia Vegetal began researching propagating Juglans regia (English walnut) and various Juglans hybrids by tissue culture in 1993 and has operated on a commercial scale since 1996. Since this time, more than one and a half million walnuts of different species have been propagated and field planted. Tissue cultured...

The Influence of Bioreactor Geometry and the Mechanical Environment on Engineered Tissues

KAUST Repository

Osborne, J. M.; O’ Dea, R. D.; Whiteley, J. P.; Byrne, H. M.; Waters, S. L.

2010-01-01

A three phase model for the growth of a tissue construct within a perfusion bioreactor is examined. The cell population (and attendant extracellular matrix), culture medium, and porous scaffold are treated as distinct phases. The bioreactor system is represented by a two-dimensional channel containing a cell-seeded rigid porous scaffold (tissue construct), which is perfused with a culture medium. Through the prescription of appropriate functional forms for cell proliferation and extracellular matrix deposition rates, the model is used to compare the influence of cell density-, pressure-, and culture medium shear stress-regulated growth on the composition of the engineered tissue. The governing equations are derived in O'Dea et al. "A Three Phase Model for Tissue Construct Growth in a Perfusion Bioreactor," Math. Med. Biol., in which the long-wavelength limit was exploited to aid analysis; here, finite element methods are used to construct two-dimensional solutions to the governing equations and to investigate thoroughly their behavior. Comparison of the total tissue yield and averaged pressures, velocities, and shear stress demonstrates that quantitative agreement between the two-dimensional and long-wavelength approximation solutions is obtained for channel aspect ratios of order 10 -2 and that much of the qualitative behavior of the model is captured in the long-wavelength limit, even for relatively large channel aspect ratios. However, we demonstrate that in order to capture accurately the effect of mechanotransduction mechanisms on tissue construct growth, spatial effects in at least two dimensions must be included due to the inherent spatial variation of mechanical stimuli relevant to perfusion bioreactors, most notably, fluid shear stress, a feature not captured in the long-wavelength limit. Copyright © 2010 by ASME.

The Influence of Bioreactor Geometry and the Mechanical Environment on Engineered Tissues

KAUST Repository

Osborne, J. M.

2010-01-01

A three phase model for the growth of a tissue construct within a perfusion bioreactor is examined. The cell population (and attendant extracellular matrix), culture medium, and porous scaffold are treated as distinct phases. The bioreactor system is represented by a two-dimensional channel containing a cell-seeded rigid porous scaffold (tissue construct), which is perfused with a culture medium. Through the prescription of appropriate functional forms for cell proliferation and extracellular matrix deposition rates, the model is used to compare the influence of cell density-, pressure-, and culture medium shear stress-regulated growth on the composition of the engineered tissue. The governing equations are derived in O\\'Dea et al. "A Three Phase Model for Tissue Construct Growth in a Perfusion Bioreactor," Math. Med. Biol., in which the long-wavelength limit was exploited to aid analysis; here, finite element methods are used to construct two-dimensional solutions to the governing equations and to investigate thoroughly their behavior. Comparison of the total tissue yield and averaged pressures, velocities, and shear stress demonstrates that quantitative agreement between the two-dimensional and long-wavelength approximation solutions is obtained for channel aspect ratios of order 10 -2 and that much of the qualitative behavior of the model is captured in the long-wavelength limit, even for relatively large channel aspect ratios. However, we demonstrate that in order to capture accurately the effect of mechanotransduction mechanisms on tissue construct growth, spatial effects in at least two dimensions must be included due to the inherent spatial variation of mechanical stimuli relevant to perfusion bioreactors, most notably, fluid shear stress, a feature not captured in the long-wavelength limit. Copyright © 2010 by ASME.

[Comparative study on alkaloids of tissue-culture seedling and wild plant of Dendrobium huoshanense ].

Science.gov (United States)

Chen, Nai-dong; Gao, Feng; Lin, Xin; Jin, Hui

2014-06-01

To compare the composition and content of alkaloid of Dendrobium huoshanense tissue-culture seedling and wild plant. A comparative evaluation on the quality was carried out by HPLC and TLC methods including the composition and the content of alkaloids. Remarkable variation existed in the two kinds of Dendrobium huoshanense. For the tissue-culture plant, only two alkaloids were checked out by both HPLC and TLC while four alkaloids were observed in the wild plant. The alkaloid content of tissue-culture seedling and wild plant was(0. 29 ± 0. 11)%o and(0. 43 ± 0. 15) %o,respectively. Distinguished difference is observed in both composition and content of alkaloids from the annual shoots of different provenances of Dendrobium huoshanense. It suggested that the quality of tissue-culture seedling of Dendrobium huoshanense might be inconsistent with the wild plant. Furthermore, the established alkaloids-knock-out HPLC method would provide a new research tool on quality control of Chinese medicinal materials which contain unknown alkaloids.

Biotransformations with plant tissue cultures.

Science.gov (United States)

Carew, D P; Bainbridge, T

1976-01-01

Suspension cultures of Catharanthus roseus, Apocynum cannabinum and Conium maculatum were examined for their capacity to transform aniline, anisole, acetanilide, benzoic acid and coumarin. None of the cultures transformed acetanilide but each produced acetanilide when fed aniline. All three cultures converted benzoic acid to its para-hydroxy derivative. Coumarin was selectively hydroxylated at the 7-position by Catharanthus and Conium and anisole was O-demethylated only by older Catharanthus tissue.

Three-dimensional bioprinting of stem-cell derived tissues for human regenerative medicine.

Science.gov (United States)

Skeldon, Gregor; Lucendo-Villarin, Baltasar; Shu, Wenmiao

2018-07-05

Stem cell technology in regenerative medicine has the potential to provide an unlimited supply of cells for drug testing, medical transplantation and academic research. In order to engineer a realistic tissue model using stem cells as an alternative to human tissue, it is essential to create artificial stem cell microenvironment or niches. Three-dimensional (3D) bioprinting is a promising tissue engineering field that offers new opportunities to precisely place stem cells within their niches layer-by-layer. This review covers bioprinting technologies, the current development of 'bio-inks' and how bioprinting has already been applied to stem-cell culture, as well as their applications for human regenerative medicine. The key considerations for bioink properties such as stiffness, stability and biodegradation, biocompatibility and printability are highlighted. Bioprinting of both adult and pluriopotent stem cells for various types of artificial tissues from liver to brain has been reviewed. 3D bioprinting of stem-cell derived tissues for human regenerative medicine is an exciting emerging area that represents opportunities for new research, industries and products as well as future challenges in clinical translation.This article is part of the theme issue 'Designer human tissue: coming to a lab near you'. © 2018 The Author(s).

ONE-DIMENSIONAL AND TWO-DIMENSIONAL LEADERSHIP STYLES

Directory of Open Access Journals (Sweden)

Nikola Stefanović

2007-06-01

Full Text Available In order to motivate their group members to perform certain tasks, leaders use different leadership styles. These styles are based on leaders' backgrounds, knowledge, values, experiences, and expectations. The one-dimensional styles, used by many world leaders, are autocratic and democratic styles. These styles lie on the two opposite sides of the leadership spectrum. In order to precisely define the leadership styles on the spectrum between the autocratic leadership style and the democratic leadership style, leadership theory researchers use two dimensional matrices. The two-dimensional matrices define leadership styles on the basis of different parameters. By using these parameters, one can identify two-dimensional styles.

Two-dimensional real-time blood flow and temperature of soft tissue around maxillary anterior implants.

Science.gov (United States)

Nakamoto, Tetsuji; Kanao, Masato; Kondo, Yusuke; Kajiwara, Norihiro; Masaki, Chihiro; Takahashi, Tetsu; Hosokawa, Ryuji

2012-12-01

The aims of this study were to (1) evaluate the basic nature of soft tissue surrounding maxillary anterior implants by simultaneous measurements of blood flow and surface temperature and (2) analyze differences with and without bone grafting associated with implant placement to try to detect the signs of surface morphology change. Twenty maxillary anterior implant patients, 10 bone grafting and 10 graftless, were involved in this clinical trial. Soft tissue around the implant was evaluated with 2-dimensional laser speckle imaging and a thermograph. Blood flow was significantly lower in attached gingiva surrounding implants in graftless patients (P = 0.0468). On the other hand, it was significantly lower in dental papillae (P = 0.0254), free gingiva (P = 0.0198), and attached gingiva (P = 0.00805) in bone graft patients. Temperature was significantly higher in free gingiva (P = 0.00819) and attached gingiva (P = 0.00593) in graftless patients, whereas it was significantly higher in dental papilla and free gingiva in implants with bone grafting. The results suggest that simultaneous measurements of soft-tissue blood flow and temperature is a useful technique to evaluate the microcirculation of soft tissue surrounding implants.

Tissue culture as a plant production technique for horticultural crops ...

African Journals Online (AJOL)

Over 100 years ago, Haberlandt envisioned the concept of plant tissue culture and provided the groundwork for the cultivation of plant cells, tissues and organs in culture. Initially plant tissue cultures arose as a research tool and focused on attempts to culture and study the development of small, isolated cells and segments ...

Renal cell carcinoma primary cultures maintain genomic and phenotypic profile of parental tumor tissues.

Science.gov (United States)

Cifola, Ingrid; Bianchi, Cristina; Mangano, Eleonora; Bombelli, Silvia; Frascati, Fabio; Fasoli, Ester; Ferrero, Stefano; Di Stefano, Vitalba; Zipeto, Maria A; Magni, Fulvio; Signorini, Stefano; Battaglia, Cristina; Perego, Roberto A

2011-06-13

Clear cell renal cell carcinoma (ccRCC) is characterized by recurrent copy number alterations (CNAs) and loss of heterozygosity (LOH), which may have potential diagnostic and prognostic applications. Here, we explored whether ccRCC primary cultures, established from surgical tumor specimens, maintain the DNA profile of parental tumor tissues allowing a more confident CNAs and LOH discrimination with respect to the original tissues. We established a collection of 9 phenotypically well-characterized ccRCC primary cell cultures. Using the Affymetrix SNP array technology, we performed the genome-wide copy number (CN) profiling of both cultures and corresponding tumor tissues. Global concordance for each culture/tissue pair was assayed evaluating the correlations between whole-genome CN profiles and SNP allelic calls. CN analysis was performed using the two CNAG v3.0 and Partek software, and comparing results returned by two different algorithms (Hidden Markov Model and Genomic Segmentation). A very good overlap between the CNAs of each culture and corresponding tissue was observed. The finding, reinforced by high whole-genome CN correlations and SNP call concordances, provided evidence that each culture was derived from its corresponding tissue and maintained the genomic alterations of parental tumor. In addition, primary culture DNA profile remained stable for at least 3 weeks, till to third passage. These cultures showed a greater cell homogeneity and enrichment in tumor component than original tissues, thus enabling a better discrimination of CNAs and LOH. Especially for hemizygous deletions, primary cultures presented more evident CN losses, typically accompanied by LOH; differently, in original tissues the intensity of these deletions was weaken by normal cell contamination and LOH calls were missed. ccRCC primary cultures are a reliable in vitro model, well-reproducing original tumor genetics and phenotype, potentially useful for future functional approaches

Application of Hanging Drop Technique for Kidney Tissue Culture.

Science.gov (United States)

Wang, Shaohui; Wang, Ximing; Boone, Jasmine; Wie, Jin; Yip, Kay-Pong; Zhang, Jie; Wang, Lei; Liu, Ruisheng

2017-01-01

The hanging drop technique is a well-established method used in culture of animal tissues. However, this method has not been used in adult kidney tissue culture yet. This study was to explore the feasibility of using this technique for culturing adult kidney cortex to study the time course of RNA viability in the tubules and vasculature, as well as the tissue structural integrity. In each Petri dish with the plate covered with sterile buffer, a section of mouse renal cortex was cultured within a drop of DMEM culture medium on the inner surface of the lip facing downward. The tissue were then harvested at each specific time points for Real-time PCR analysis and histological studies. The results showed that the mRNA level of most Na+ related transporters and cotransporters were stably maintained within 6 hours in culture, and that the mRNA level of most receptors found in the vasculature and glomeruli were stably maintained for up to 9 days in culture. Paraffin sections of the cultured renal cortex indicated that the tubules began to lose tubular integrity after 6 hours, but the glomeruli and vasculatures were still recognizable up to 9 days in culture. We concluded that adult kidney tissue culture by hanging drop method can be used to study gene expressions in vasculature and glomeruli. © 2017 The Author(s). Published by S. Karger AG, Basel.

Application of Hanging Drop Technique for Kidney Tissue Culture

Directory of Open Access Journals (Sweden)

Shaohui Wang

2017-05-01

Full Text Available Background/Aims: The hanging drop technique is a well-established method used in culture of animal tissues. However, this method has not been used in adult kidney tissue culture yet. This study was to explore the feasibility of using this technique for culturing adult kidney cortex to study the time course of RNA viability in the tubules and vasculature, as well as the tissue structural integrity. Methods: In each Petri dish with the plate covered with sterile buffer, a section of mouse renal cortex was cultured within a drop of DMEM culture medium on the inner surface of the lip facing downward. The tissue were then harvested at each specific time points for Real-time PCR analysis and histological studies. Results: The results showed that the mRNA level of most Na+ related transporters and cotransporters were stably maintained within 6 hours in culture, and that the mRNA level of most receptors found in the vasculature and glomeruli were stably maintained for up to 9 days in culture. Paraffin sections of the cultured renal cortex indicated that the tubules began to lose tubular integrity after 6 hours, but the glomeruli and vasculatures were still recognizable up to 9 days in culture. Conclusions: We concluded that adult kidney tissue culture by hanging drop method can be used to study gene expressions in vasculature and glomeruli.

The use of animal tissues alongside human tissue: Cultural and ethical considerations.

Science.gov (United States)

Kaw, Anu; Jones, D Gareth; Zhang, Ming

2016-01-01

Teaching and research facilities often use cadaveric material alongside animal tissues, although there appear to be differences in the way we handle, treat, and dispose of human cadaveric material compared to animal tissue. This study sought to analyze cultural and ethical considerations and provides policy recommendations on the use of animal tissues alongside human tissue. The status of human and animal remains and the respect because of human and animal tissues were compared and analyzed from ethical, legal, and cultural perspectives. The use of animal organs and tissues is carried out within the context of understanding human anatomy and function. Consequently, the interests of human donors are to be pre-eminent in any policies that are enunciated, so that if any donors find the presence of animal remains unacceptable, the latter should not be employed. The major differences appear to lie in differences in our perceptions of their respective intrinsic and instrumental values. Animals are considered to have lesser intrinsic value and greater instrumental value than humans. These differences stem from the role played by culture and ethical considerations, and are manifested in the resulting legal frameworks. In light of this discussion, six policy recommendations are proposed, encompassing the nature of consent, respect for animal tissues as well as human remains, and appropriate separation of both sets of tissues in preparation and display. © 2015 Wiley Periodicals, Inc.

Electrospinning PCL Scaffolds Manufacture for Three-Dimensional Breast Cancer Cell Culture

Directory of Open Access Journals (Sweden)

Marc Rabionet

2017-08-01

Full Text Available In vitro cell culture is traditionally performed within two-dimensional (2D environments, providing a quick and cheap way to study cell properties in a laboratory. However, 2D systems differ from the in vivo environment and may not mimic the physiological cell behavior realistically. For instance, 2D culture models are thought to induce cancer stem cells (CSCs differentiation, a rare cancer cell subpopulation responsible for tumor initiation and relapse. This fact hinders the development of therapeutic strategies for tumors with a high relapse percentage, such as triple negative breast cancer (TNBC. Thus, three-dimensional (3D scaffolds have emerged as an attractive alternative to monolayer culture, simulating the extracellular matrix structure and maintaining the differentiation state of cells. In this work, scaffolds were fabricated through electrospinning different poly(ε-caprolactone-acetone solutions. Poly(ε-caprolactone (PCL meshes were seeded with triple negative breast cancer (TNBC cells and 15% PCL scaffolds displayed significantly (p < 0.05 higher cell proliferation and elongation than the other culture systems. Moreover, cells cultured on PCL scaffolds exhibited higher mammosphere forming capacity and aldehyde dehydrogenase activity than 2D-cultured cells, indicating a breast CSCs enrichment. These results prove the powerful capability of electrospinning technology in terms of poly(ε-caprolactone nanofibers fabrication. In addition, this study has demonstrated that electrospun 15% PCL scaffolds are suitable tools to culture breast cancer cells in a more physiological way and to expand the niche of breast CSCs. In conclusion, three-dimensional cell culture using PCL scaffolds could be useful to study cancer stem cell behavior and may also trigger the development of new specific targets against such malignant subpopulation.

Two-dimensional NMR spectrometry

International Nuclear Information System (INIS)

Farrar, T.C.

1987-01-01

This article is the second in a two-part series. In part one (ANALYTICAL CHEMISTRY, May 15) the authors discussed one-dimensional nuclear magnetic resonance (NMR) spectra and some relatively advanced nuclear spin gymnastics experiments that provide a capability for selective sensitivity enhancements. In this article and overview and some applications of two-dimensional NMR experiments are presented. These powerful experiments are important complements to the one-dimensional experiments. As in the more sophisticated one-dimensional experiments, the two-dimensional experiments involve three distinct time periods: a preparation period, t 0 ; an evolution period, t 1 ; and a detection period, t 2

Reversible gelling culture media for in-vitro cell culture in three-dimensional matrices

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An, Yuehuei H.; Mironov, Vladimir A.; Gutowska, Anna

2000-01-01

A gelling cell culture medium useful for forming a three dimensional matrix for cell culture in vitro is prepared by copolymerizing an acrylamide derivative with a hydrophilic comonomer to form a reversible (preferably thermally reversible) gelling linear random copolymer in the form of a plurality of linear chains having a plurality of molecular weights greater than or equal to a minimum gelling molecular weight cutoff, mixing the copolymer with an aqueous solvent to form a reversible gelling solution and adding a cell culture medium to the gelling solution to form the gelling cell culture medium. Cells such as chondrocytes or hepatocytes are added to the culture medium to form a seeded culture medium, and temperature of the medium is raised to gel the seeded culture medium and form a three dimensional matrix containing the cells. After propagating the cells in the matrix, the cells may be recovered by lowering the temperature to dissolve the matrix and centrifuging.

Three-dimensional scaffold-free fusion culture: the way to enhance chondrogenesis of in vitro propagated human articular chondrocytes

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M. Lehmann

2013-11-01

Full Text Available Cartilage regeneration based on isolated and culture-expanded chondrocytes has been studied in various in vitro models, but the quality varies with respect to the morphology and the physiology of the synthesized tissues. The aim of our study was to promote in vitro chondrogenesis of human articular chondrocytes using a novel three-dimensional (3-D cultivation system in combination with the chondrogenic differentiation factors transforming growth factor beta 2 (TGF-b2 and L-ascorbic acid. Articular chondrocytes isolated from six elderly patients were expanded in monolayer culture. A single-cell suspension of the dedifferentiated chondrocytes was then added to agar-coated dishes without using any scaffold material, in the presence, or absence of TGF-b2 and/or L-ascorbic acid. Three-dimensional cartilage-like constructs, called single spheroids, and microtissues consisting of several spheroids fused together, named as fusions, were formed. Generated tissues were mainly characterized using histological and immunohistochemical techniques. The morphology of the in vitro tissues shared some similarities to native hyaline cartilage in regard to differentiated S100-positive chondrocytes within a cartilaginous matrix, with strong collagen type II expression and increased synthesis of proteoglycans. Finally, our innovative scaffold-free fusion culture technique supported enhanced chondrogenesis of human articular chondrocytes in vitro. These 3-D hyaline cartilage-like microtissues will be useful for in vitro studies of cartilage differentiation and regeneration, enabling optimization of functional tissue engineering and possibly contributing to the development of new approaches to treat traumatic cartilage defects or osteoarthritis.

Ultrasonic three-dimensional on-chip cell culture for dynamic studies of tumor immune surveillance by natural killer cells.

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Christakou, Athanasia E; Ohlin, Mathias; Önfelt, Björn; Wiklund, Martin

2015-08-07

We demonstrate a simple method for three-dimensional (3D) cell culture controlled by ultrasonic standing waves in a multi-well microplate. The method gently arranges cells in a suspension into a single aggregate in each well of the microplate and, by this, nucleates 3D tissue-like cell growth for culture times between two and seven days. The microplate device is compatible with both high-resolution optical microscopy and maintenance in a standard cell incubator. The result is a scaffold- and coating-free method for 3D cell culture that can be used for controlling the cellular architecture, as well as the cellular and molecular composition of the microenvironment in and around the formed cell structures. We demonstrate the parallel production of one hundred synthetic 3D solid tumors comprising up to thousands of human hepatocellular carcinoma (HCC) HepG2 cells, we characterize the tumor structure by high-resolution optical microscopy, and we monitor the functional behavior of natural killer (NK) cells migrating, docking and interacting with the tumor model during culture. Our results show that the method can be used for determining the collective ability of a given number of NK cells to defeat a solid tumor having a certain size, shape and composition. The ultrasound-based method itself is generic and can meet any demand from applications where it is advantageous to monitor cell culture from production to analysis of 3D tissue or tumor models using microscopy in one single microplate device.

Three-dimensional bioprinting in tissue engineering and regenerative medicine.

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Gao, Guifang; Cui, Xiaofeng

2016-02-01

With the advances of stem cell research, development of intelligent biomaterials and three-dimensional biofabrication strategies, highly mimicked tissue or organs can be engineered. Among all the biofabrication approaches, bioprinting based on inkjet printing technology has the promises to deliver and create biomimicked tissue with high throughput, digital control, and the capacity of single cell manipulation. Therefore, this enabling technology has great potential in regenerative medicine and translational applications. The most current advances in organ and tissue bioprinting based on the thermal inkjet printing technology are described in this review, including vasculature, muscle, cartilage, and bone. In addition, the benign side effect of bioprinting to the printed mammalian cells can be utilized for gene or drug delivery, which can be achieved conveniently during precise cell placement for tissue construction. With layer-by-layer assembly, three-dimensional tissues with complex structures can be printed using converted medical images. Therefore, bioprinting based on thermal inkjet is so far the most optimal solution to engineer vascular system to the thick and complex tissues. Collectively, bioprinting has great potential and broad applications in tissue engineering and regenerative medicine. The future advances of bioprinting include the integration of different printing mechanisms to engineer biphasic or triphasic tissues with optimized scaffolds and further understanding of stem cell biology.

Advances in tissue engineering through stem cell-based co-culture.

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Paschos, Nikolaos K; Brown, Wendy E; Eswaramoorthy, Rajalakshmanan; Hu, Jerry C; Athanasiou, Kyriacos A

2015-05-01

Stem cells are the future in tissue engineering and regeneration. In a co-culture, stem cells not only provide a target cell source with multipotent differentiation capacity, but can also act as assisting cells that promote tissue homeostasis, metabolism, growth and repair. Their incorporation into co-culture systems seems to be important in the creation of complex tissues or organs. In this review, critical aspects of stem cell use in co-culture systems are discussed. Direct and indirect co-culture methodologies used in tissue engineering are described, along with various characteristics of cellular interactions in these systems. Direct cell-cell contact, cell-extracellular matrix interaction and signalling via soluble factors are presented. The advantages of stem cell co-culture strategies and their applications in tissue engineering and regenerative medicine are portrayed through specific examples for several tissues, including orthopaedic soft tissues, bone, heart, vasculature, lung, kidney, liver and nerve. A concise review of the progress and the lessons learned are provided, with a focus on recent developments and their implications. It is hoped that knowledge developed from one tissue can be translated to other tissues. Finally, we address challenges in tissue engineering and regenerative medicine that can potentially be overcome via employing strategies for stem cell co-culture use. Copyright © 2014 John Wiley & Sons, Ltd.

Study on tissue culture for Gelidium seedling

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Pei, Lu-Qing; Luo, Qi-Jun; Fei, Zhi-Qing; Ma, Bin

1996-06-01

As seedling culture is a crucial factor for successful cultivation of Gelidium, the authors researched tissue culture technology for producing seedlings. The morphogeny and experimental ecology were observed and studied fully in 2 5 mm isolated tissue fragments. Regeneration, appearance of branching creepers and attaching structure and new erect seedlings production and development were studied. Fragments were sown on bamboo slice and vinylon rope. The seedlings were cultured 20 30 days indoor, then cultured in the sea, where the density of erect seedlings was 3 19 seedlings/cm2, growth rate was 3.84% day. The frond arising from seedlings directly was up to 10 cm per year. The ecological conditions for regenerated seedlings are similar to the natural ones. The regenerated seedlings are suitable for raft culture in various sea areas.

Oxygen and tissue culture affect placental gene expression.

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Brew, O; Sullivan, M H F

2017-07-01

Placental explant culture is an important model for studying placental development and functions. We investigated the differences in placental gene expression in response to tissue culture, atmospheric and physiologic oxygen concentrations. Placental explants were collected from normal term (38-39 weeks of gestation) placentae with no previous uterine contractile activity. Placental transcriptomic expressions were evaluated with GeneChip ® Human Genome U133 Plus 2.0 arrays (Affymetrix). We uncovered sub-sets of genes that regulate response to stress, induction of apoptosis programmed cell death, mis-regulation of cell growth, proliferation, cell morphogenesis, tissue viability, and protection from apoptosis in cultured placental explants. We also identified a sub-set of genes with highly unstable pattern of expression after exposure to tissue culture. Tissue culture irrespective of oxygen concentration induced dichotomous increase in significant gene expression and increased enrichment of significant pathways and transcription factor targets (TFTs) including HIF1A. The effect was exacerbated by culture at atmospheric oxygen concentration, where further up-regulation of TFTs including PPARA, CEBPD, HOXA9 and down-regulated TFTs such as JUND/FOS suggest intrinsic heightened key biological and metabolic mechanisms such as glucose use, lipid biosynthesis, protein metabolism; apoptosis, inflammatory responses; and diminished trophoblast proliferation, differentiation, invasion, regeneration, and viability. These findings demonstrate that gene expression patterns differ between pre-culture and cultured explants, and the gene expression of explants cultured at atmospheric oxygen concentration favours stressed, pro-inflammatory and increased apoptotic transcriptomic response. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effects of ionizing radiation on plant tissue cultures

International Nuclear Information System (INIS)

Hell, K.G.

1978-01-01

A short review is done of the biological effects of ionizing radiations on plant tissues kept in culture, from the work of Gladys King, in 1949, with X-ray irradiated tobacco. The role of plant hormones is discussed in the processes of growth inhibition and growth restoration of irradiated tissues, as well as morphogenesis. Radioresistance of cells kept in culture and the use of ionizing radiations as mutagens are also commented. Some aspects of the biological effects of ionizing radiations that need to be investigated are discussed, and the problem of genome instability of plant tissues kept in culture is pointed out. (M.A.) [pt

Formation of proteoglycan and collagen-rich scaffold-free stiff cartilaginous tissue using two-step culture methods with combinations of growth factors.

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Miyazaki, Tatsuya; Miyauchi, Satoshi; Matsuzaka, Satoshi; Yamagishi, Chie; Kobayashi, Kohei

2010-05-01

Tissue-engineered cartilage may be expected to serve as an alternative to autologous chondrocyte transplantation treatment. Several methods for producing cartilaginous tissue have been reported. In this study, we describe the production of scaffold-free stiff cartilaginous tissue of pig and human, using allogeneic serum and growth factors. The tissue was formed in a mold using chondrocytes recovered from alginate bead culture and maintained in a medium with transforming growth factor-beta and several other additives. In the case of porcine tissue, the tear strength of the tissue and the contents of proteoglycan (PG) and collagen per unit of DNA increased dose-dependently with transforming growth factor-beta. The length of culture was significantly and positively correlated with thickness, tear strength, and PG and collagen contents. Tear strength showed positive high correlations with both PG and collagen contents. A positive correlation was also seen between PG content and collagen content. Similar results were obtained with human cartilaginous tissue formed from chondrocytes expanded in monolayer culture. Further, an in vivo pilot study using pig articular cartilage defect model demonstrated that the cartilaginous tissue was well integrated with surrounding tissue at 13 weeks after the implantation. In conclusion, we successfully produced implantable scaffold-free stiff cartilaginous tissue, which characterized high PG and collagen contents.

Upregulated epidermal growth factor receptor expression following near-infrared irradiation simulating solar radiation in a three-dimensional reconstructed human corneal epithelial tissue culture model

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Tanaka Y

2016-08-01

Full Text Available Yohei Tanaka,1,2 Jun Nakayama2 1Department of Plastic Surgery, Clinica Tanaka Plastic, Reconstructive Surgery and Anti-aging Center, 2Department of Molecular Pathology, Shinshu University Graduate School of Medicine, Matsumoto, Nagano, Japan Background and objective: Humans are increasingly exposed to near-infrared (NIR radiation from both natural (eg, solar and artificial (eg, electrical appliances sources. Although the biological effects of sun and ultraviolet (UV exposure have been extensively investigated, the biological effect of NIR radiation is still unclear. We previously reported that NIR as well as UV induces photoaging and standard UV-blocking materials, such as sunglasses, do not sufficiently block NIR. The objective of this study was to investigate changes in gene expression in three-dimensional reconstructed corneal epithelial tissue culture exposed to broad-spectrum NIR irradiation to simulate solar NIR radiation that reaches human tissues.Materials and methods: DNA microarray and quantitative real-time polymerase chain reaction analysis were used to assess gene expression levels in a three-dimensional reconstructed corneal epithelial model composed of normal human corneal epithelial cells exposed to water-filtered broad-spectrum NIR irradiation with a contact cooling (20°C. The water-filter allowed 1,000–1,800 nm wavelengths and excluded 1,400–1,500 nm wavelengths.Results: A DNA microarray with >62,000 different probes showed 25 and 150 genes that were up- or downregulated by at least fourfold and twofold, respectively, after NIR irradiation. In particular, epidermal growth factor receptor (EGFR was upregulated by 19.4-fold relative to control cells. Quantitative real-time polymerase chain reaction analysis revealed that two variants of EGFR in human corneal epithelial tissue were also significantly upregulated after five rounds of 10 J/cm2 irradiation (P<0.05.Conclusion: We found that NIR irradiation induced the

3D Cell Culture in a Self-Assembled Nanofiber Environment.

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Yi Wen Chai

Full Text Available The development and utilization of three-dimensional cell culture platforms has been gaining more traction. Three-dimensional culture platforms are capable of mimicking in vivo microenvironments, which provide greater physiological relevance in comparison to conventional two-dimensional cultures. The majority of three-dimensional culture platforms are challenged by the lack of cell attachment, long polymerization times, and inclusion of undefined xenobiotics, and cytotoxic cross-linkers. In this study, we review the use of a highly defined material composed of naturally occurring compounds, hyaluronic acid and chitosan, known as Cell-Mate3DTM. Moreover, we provide an original measurement of Young's modulus using a uniaxial unconfined compression method to elucidate the difference in microenvironment rigidity for acellular and cellular conditions. When hydrated into a tissue-like hybrid hydrocolloid/hydrogel, Cell-Mate3DTM is a highly versatile three-dimensional culture platform that enables downstream applications such as flow cytometry, immunostaining, histological staining, and functional studies to be applied with relative ease.

[Chromosome variability in the tissue culture of rare Gentiana species].

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Tvardovs'ka, M O; Strashniuk, N M; Mel'nyk, V M; Adonin, V I; Kunakh, V A

2008-01-01

Cytogenetic analysis of plants and tissue culture of Gentiana lutea, G. punctata, G. acaulis has been carried out. Culturing in vitro was found to result in the changes of chromosome number in the calluses of the species involved. Species specificity for variation of the cultured cell genomes was shown. Contribution of the original plant genotypes to the cytogenetic structure of the tissue culture was established. Gentiana callus tissues (except for in vitro culture of G. punctata, derived from plant of Breskul'ska population) were found to exhibit modal class with the cells of diploid and nearly diploid chromosome sets.

Three-dimensional neural cultures produce networks that mimic native brain activity.

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Bourke, Justin L; Quigley, Anita F; Duchi, Serena; O'Connell, Cathal D; Crook, Jeremy M; Wallace, Gordon G; Cook, Mark J; Kapsa, Robert M I

2018-02-01

Development of brain function is critically dependent on neuronal networks organized through three dimensions. Culture of central nervous system neurons has traditionally been limited to two dimensions, restricting growth patterns and network formation to a single plane. Here, with the use of multichannel extracellular microelectrode arrays, we demonstrate that neurons cultured in a true three-dimensional environment recapitulate native neuronal network formation and produce functional outcomes more akin to in vivo neuronal network activity. Copyright © 2017 John Wiley & Sons, Ltd.

Three-dimensional assembly of tissue-engineered cartilage constructs results in cartilaginous tissue formation without retainment of zonal characteristics.

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Schuurman, W; Harimulyo, E B; Gawlitta, D; Woodfield, T B F; Dhert, W J A; van Weeren, P R; Malda, J

2016-04-01

Articular cartilage has limited regenerative capabilities. Chondrocytes from different layers of cartilage have specific properties, and regenerative approaches using zonal chondrocytes may yield better replication of the architecture of native cartilage than when using a single cell population. To obtain high seeding efficiency while still mimicking zonal architecture, cell pellets of expanded deep zone and superficial zone equine chondrocytes were seeded and cultured in two layers on poly(ethylene glycol)-terephthalate-poly(butylene terephthalate) (PEGT-PBT) scaffolds. Scaffolds seeded with cell pellets consisting of a 1:1 mixture of both cell sources served as controls. Parallel to this, pellets of superficial or deep zone chondrocytes, and combinations of the two cell populations, were cultured without the scaffold. Pellet cultures of zonal chondrocytes in scaffolds resulted in a high seeding efficiency and abundant cartilaginous tissue formation, containing collagen type II and glycosaminoglycans (GAGs) in all groups, irrespective of the donor (n = 3), zonal population or stratified scaffold-seeding approach used. However, whereas total GAG production was similar, the constructs retained significantly more GAG compared to pellet cultures, in which a high percentage of the produced GAGs were secreted into the culture medium. Immunohistochemistry for zonal markers did not show any differences between the conditions. We conclude that spatially defined pellet culture in 3D scaffolds is associated with high seeding efficiency and supports cartilaginous tissue formation, but did not result in the maintenance or restoration of the original zonal phenotype. The use of pellet-assembled constructs leads to a better retainment of newly produced GAGs than the use of pellet cultures alone. Copyright © 2013 John Wiley & Sons, Ltd.

Influence of postmortem time on the outcome of blood cultures among cadaveric tissue donors.

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Saegeman, V; Verhaegen, J; Lismont, D; Verduyckt, B; De Rijdt, T; Ectors, N

2009-02-01

Tissue banks provide tissues of human cadaver donors for transplantation. The maximal time limit for tissue retrieval has been set at 24 h postmortem. This study aimed at evaluating the evidence for this limit from a microbiological point of view. The delay of growth in postmortem blood cultures, the identification of the species isolated and clinical/environmental factors were investigated among 100 potential tissue donors. No significant difference was found in the rate of donors with grown blood cultures within (25/65=38%) compared with after (24/65=37%) 24 h of death. Coagulase-negative staphylococci and gastro-intestinal microorganisms were isolated within and after 24 h of death. Two factors--antimicrobial therapy and "delay before body cooling"--were significantly inversely related with donors' blood culture results. From a microbiological point of view, there is no evidence for avoiding tissue retrieval among donors after 24 h of death.

Detachably assembled microfluidic device for perfusion culture and post-culture analysis of a spheroid array.

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Sakai, Yusuke; Hattori, Koji; Yanagawa, Fumiki; Sugiura, Shinji; Kanamori, Toshiyuki; Nakazawa, Kohji

2014-07-01

Microfluidic devices permit perfusion culture of three-dimensional (3D) tissue, mimicking the flow of blood in vascularized 3D tissue in our body. Here, we report a microfluidic device composed of a two-part microfluidic chamber chip and multi-microwell array chip able to be disassembled at the culture endpoint. Within the microfluidic chamber, an array of 3D tissue aggregates (spheroids) can be formed and cultured under perfusion. Subsequently, detailed post-culture analysis of the spheroids collected from the disassembled device can be performed. This device facilitates uniform spheroid formation, growth analysis in a high-throughput format, controlled proliferation via perfusion flow rate, and post-culture analysis of spheroids. We used the device to culture spheroids of human hepatocellular carcinoma (HepG2) cells under two controlled perfusion flow rates. HepG2 spheroids exhibited greater cell growth at higher perfusion flow rates than at lower perfusion flow rates, and exhibited different metabolic activity and mRNA and protein expression under the different flow rate conditions. These results show the potential of perfusion culture to precisely control the culture environment in microfluidic devices. The construction of spheroid array chambers allows multiple culture conditions to be tested simultaneously, with potential applications in toxicity and drug screening. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Demonstration of the economic feasibility of plant tissue culture for jojoba (Simmondsia chinensis) and Euphorbia spp

Energy Technology Data Exchange (ETDEWEB)

Sluis, C.

1980-09-01

The economic feasibility of plant tissue culture was demonstrated as applied to two plants: jojoba (Simmondsia chinensis) and Euphorbia spp. The gopher weed (Euphorbia lathyris) was selected as the species of Euphorbia to research due to the interest in this plant as a potential source of hydrocarbon-like compounds. High yield female selections of jojoba were chosen from native stands and were researched to determine the economic feasibility of mass producing these plants via a tissue culture micropropagation program. The female jojoba selection was successfully mass produced through tissue culture. Modifications in initiation techniques, as well as in multiplication media and rooting parameters, were necessary to apply the tissue culture system, which had been developed for juvenile seedling tissue, to mature jojobas. Since prior attempts at transfer of tissue cultured plantlets were unsuccessful, transfer research was a major part of the project and has resulted in a system for transfer of rooted jojoba plantlets to soil. Euphorbia lathyris was successfully cultured using shoot tip cultures. Media and procedures were established for culture initiation, multiplication of shoots, callus induction and growth, and root initiation. Well-developed root systems were not attained and root initiation percentages should be increased if the system is to become commercially feasible.

Mass spectrometric characterization of elements and molecules in cell cultures and tissues

International Nuclear Information System (INIS)

Arlinghaus, H.F.; Kriegeskotte, C.; Fartmann, M.; Wittig, A.; Sauerwein, W.; Lipinsky, D.

2006-01-01

Time-of-flight secondary ion mass spectrometry (ToF-SIMS) and laser post-ionization secondary neutral mass spectrometry (laser-SNMS) have been used to image and quantify targeted compounds, intrinsic elements and molecules with subcellular resolution in single cells of both cell cultures and tissues. Special preparation procedures for analyzing cell cultures and tissue materials were developed. Cancer cells type MeWo, incubated with boronated compounds, were sandwiched between two substrates, cryofixed, freeze-fractured and freeze-dried. Also, after injection with boronated compounds, different types of mouse tissues were extracted, prepared on a special specimen carrier and plunged with high velocity into LN 2 -cooled propane for cryofixation. After trimming, these tissue blocks were freeze-dried. The measurements of the K/Na ratio demonstrated that for both cell cultures and tissue materials the special preparation techniques used were appropriate for preserving the chemical and structural integrity of the living cell. The boron images show inter- and intracellular boron signals with different intensities. Molecular images show distinct features partly correlated with the cell structure. A comparison between laser-SNMS and ToF-SIMS showed that especially laser-SNMS is particularly well-suited for identifying specific cell structures and imaging ultratrace element concentrations in tissues

Evaluation of the secretion and release of vascular endothelial growth factor from two-dimensional culture and three-dimensional cell spheroids formed with stem cells and osteoprecursor cells.

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Lee, Hyunjin; Lee, Sung-Il; Ko, Youngkyung; Park, Jun-Beom

2018-05-18

Co-culture has been applied in cell therapy, including stem cells, and has been reported to give enhanced functionality. In this study, stem-cell spheroids were formed in concave micromolds at different ratios of stem cells to osteoprecursor cells, and the amount of secretion of vascular endothelial growth factor (VEGF) was evaluated. Gingiva-derived stem cells and osteoprecursor cells in the amount of 6 × 105 were seeded on a 24-well culture plate or concave micromolds. The ratios of stem cells to osteoprecursor cells included: 0:4 (group 1), 1:3 (group 2), 2:2 (group 3), 3:1 (group 4), and 4:0 (group 5). The morphology of cells in a 2-dimensional culture (groups 1-5) showed a fibroblast-like appearance. The secretion of VEGF increased with the increase in stem cells, and a statistically significant increase was noted in groups 3, 4 and 5 when compared with the media-only group (p cells formed spheroids in concave microwells, and no noticeable change in the morphology was noted with the increase in stem cells. Spheroids containing stem cells were positive for the stem-cell markers SSEA-4. The secretion of VEGF from cell spheroids increased with the increase in stem cells. This study showed that cell spheroids formed with stem cells and osteoprecursor cells with different ratios, using microwells, had paracrine effects on the stem cells. The secretion of VEGF increased with the increase in stem cells. This stem-cell spheroid may be applied for tissue-engineering purposes.

A Novel Microgravity Simulator Applicable for Three-Dimensional Cell Culturing

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Wuest, Simon L.; Richard, Stéphane; Walther, Isabelle; Furrer, Reinhard; Anderegg, Roland; Sekler, Jörg; Egli, Marcel

2014-10-01

Random Positioning Machines (RPM) were introduced decades ago to simulate microgravity. Since then numerous experiments have been carried out to study its influence on biological samples. The machine is valued by the scientific community involved in space relevant topics as an excellent experimental tool to conduct pre-studies, for example, before sending samples into space. We have developed a novel version of the traditional RPM to broaden its operative range. This novel version has now become interesting to researchers who are working in the field of tissue engineering, particularly those interested in alternative methods for three-dimensional (3D) cell culturing. The main modifications concern the cell culture condition and the algorithm that controls the movement of the frames for the nullification of gravity. An incubator was integrated into the inner frame of the RPM allowing precise control over the cell culture environment. Furthermore, several feed-throughs now allow a permanent supply of gas like CO 2. All these modifications substantially improve conditions to culture cells; furthermore, the rewritten software responsible for controlling the movement of the frames enhances the quality of the generated microgravity. Cell culture experiments were carried out with human lymphocytes on the novel RPM model to compare the obtained response to the results gathered on an older well-established RPM as well as to data from space flights. The overall outcome of the tests validates this novel RPM for cell cultivation under simulated microgravity conditions.

Addressing the instability of DNA nanostructures in tissue culture.

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Hahn, Jaeseung; Wickham, Shelley F J; Shih, William M; Perrault, Steven D

2014-09-23

DNA nanotechnology is an advanced technique that could contribute diagnostic, therapeutic, and biomedical research devices to nanomedicine. Although such devices are often developed and demonstrated using in vitro tissue culture models, these conditions may not be compatible with DNA nanostructure integrity and function. The purpose of this study was to characterize the sensitivity of 3D DNA nanostructures produced via the origami method to the in vitro tissue culture environment and identify solutions to prevent loss of nanostructure integrity. We examined whether the physiological cation concentrations of cell culture medium and the nucleases present in fetal bovine serum (FBS) used as a medium supplement result in denaturation and digestion, respectively. DNA nanostructure denaturation due to cation depletion was design- and time-dependent, with one of four tested designs remaining intact after 24 h at 37 °C. Adjustment of medium by addition of MgSO4 prevented denaturation. Digestion of nanostructures by FBS nucleases in Mg(2+)-adjusted medium did not appear design-dependent and became significant within 24 h and when medium was supplemented with greater than 5% FBS. We estimated that medium supplemented with 10% FBS contains greater than 256 U/L equivalent of DNase I activity in digestion of DNA nanostructures. Heat inactivation at 75 °C and inclusion of actin protein in medium inactivated and inhibited nuclease activity, respectively. We examined the impact of medium adjustments on cell growth, viability, and phenotype. Adjustment of Mg(2+) to 6 mM did not appear to have a detrimental impact on cells. Heat inactivation was found to be incompatible with in vitro tissue culture, whereas inclusion of actin had no observable effect on growth and viability. In two in vitro assays, immune cell activation and nanoparticle endocytosis, we show that using conditions compatible with cell phenotype and nanostructure integrity is critical for obtaining reliable

Variations on metabolic activities of legume tissues through radiation in tissue culture

International Nuclear Information System (INIS)

Batra, Amla

1977-01-01

Cell cultures from Arachis hypogaea L. cultivated in a modified medium developed by Murashige and Skoog (1962) showed vigorous qrowth after radiation treatment. Investigations on the effect of various sugars on the chlorophyll formation and growth of the irradiated tissues showed that sucrose was superior to maltose, glucose or fructose as a carbon source. Lactose and mannitol supported growth and development of chlorophyll to a less degree. On prolonging the cultures on a sugar free medium, the tissues failed to regain either growth or chlorophyll content. (author)

Variations on metabolic activities of legume tissues through radiation in tissue culture

Energy Technology Data Exchange (ETDEWEB)

Batra, A [Rajasthan Univ., Jaipur (India). Dept. of Botany

1977-12-01

Cell cultures from Arachis hypogaea L. cultivated in a modified medium developed by Murashige and Skoog (1962) showed vigorous qrowth after radiation treatment. Investigations on the effect of various sugars on the chlorophyll formation and growth of the irradiated tissues showed that sucrose was superior to maltose, glucose or fructose as a carbon source. Lactose and mannitol supported growth and development of chlorophyll to a less degree. On prolonging the cultures on a sugar free medium, the tissues failed to regain either growth or chlorophyll content.

Embryonic stem cells in scaffold-free three-dimensional cell culture: osteogenic differentiation and bone generation.

Science.gov (United States)

Handschel, Jörg; Naujoks, Christian; Depprich, Rita; Lammers, Lydia; Kübler, Norbert; Meyer, Ulrich; Wiesmann, Hans-Peter

2011-07-14

Extracorporeal formation of mineralized bone-like tissue is still an unsolved challenge in tissue engineering. Embryonic stem cells may open up new therapeutic options for the future and should be an interesting model for the analysis of fetal organogenesis. Here we describe a technique for culturing embryonic stem cells (ESCs) in the absence of artificial scaffolds which generated mineralized miromasses. Embryonic stem cells were harvested and osteogenic differentiation was stimulated by the addition of dexamethasone, ascorbic acid, and ß-glycerolphosphate (DAG). After three days of cultivation microspheres were formed. These spherical three-dimensional cell units showed a peripheral zone consisting of densely packed cell layers surrounded by minerals that were embedded in the extracellular matrix. Alizarine red staining confirmed evidence of mineralization after 10 days of DAG stimulation in the stimulated but not in the control group. Transmission electron microscopy demonstrated scorching crystallites and collagenous fibrils as early indication of bone formation. These extracellular structures resembled hydroxyl apatite-like crystals as demonstrated by distinct diffraction patterns using electron diffraction analysis. The micromass culture technique is an appropriate model to form three-dimensional bone-like micro-units without the need for an underlying scaffold. Further studies will have to show whether the technique is applicable also to pluripotent stem cells of different origin. © 2011 Handschel et al; licensee BioMed Central Ltd.

Embryonic stem cells in scaffold-free three-dimensional cell culture: osteogenic differentiation and bone generation

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Meyer Ulrich

2011-07-01

Full Text Available Abstract Extracorporeal formation of mineralized bone-like tissue is still an unsolved challenge in tissue engineering. Embryonic stem cells may open up new therapeutic options for the future and should be an interesting model for the analysis of fetal organogenesis. Here we describe a technique for culturing embryonic stem cells (ESCs in the absence of artificial scaffolds which generated mineralized miromasses. Embryonic stem cells were harvested and osteogenic differentiation was stimulated by the addition of dexamethasone, ascorbic acid, and ß-glycerolphosphate (DAG. After three days of cultivation microspheres were formed. These spherical three-dimensional cell units showed a peripheral zone consisting of densely packed cell layers surrounded by minerals that were embedded in the extracellular matrix. Alizarine red staining confirmed evidence of mineralization after 10 days of DAG stimulation in the stimulated but not in the control group. Transmission electron microscopy demonstrated scorching crystallites and collagenous fibrils as early indication of bone formation. These extracellular structures resembled hydroxyl apatite-like crystals as demonstrated by distinct diffraction patterns using electron diffraction analysis. The micromass culture technique is an appropriate model to form three-dimensional bone-like micro-units without the need for an underlying scaffold. Further studies will have to show whether the technique is applicable also to pluripotent stem cells of different origin.

A fluid dynamics approach to bioreactor design for cell and tissue culture.

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Dusting, Jonathan; Sheridan, John; Hourigan, Kerry

2006-08-20

The problem of controlling cylindrical tank bioreactor conditions for cell and tissue culture purposes has been considered from a flow dynamics perspective. Simple laminar flows in the vortex breakdown region are proposed as being a suitable alternative to turbulent spinner flask flows and horizontally oriented rotational flows. Vortex breakdown flows have been measured using three-dimensional Stereoscopic particle image velocimetry, and non-dimensionalized velocity and stress distributions are presented. Regions of locally high principal stress occur in the vicinity of the impeller and the lower sidewall. Topological changes in the vortex breakdown region caused by an increase in Reynolds number are reflected in a redistribution of the peak stress regions. The inclusion of submerged scaffold models adds complexity to the flow, although vortex breakdown may still occur. Relatively large stresses occur along the edge of disks jutting into the boundary of the vortex breakdown region. Copyright 2006 Wiley Periodicals, Inc.

Co-culture systems-based strategies for articular cartilage tissue engineering.

Science.gov (United States)

Zhang, Yu; Guo, Weimin; Wang, Mingjie; Hao, Chunxiang; Lu, Liang; Gao, Shuang; Zhang, Xueliang; Li, Xu; Chen, Mingxue; Li, Penghao; Jiang, Peng; Lu, Shibi; Liu, Shuyun; Guo, Quanyi

2018-03-01

Cartilage engineering facilitates repair and regeneration of damaged cartilage using engineered tissue that restores the functional properties of the impaired joint. The seed cells used most frequently in tissue engineering, are chondrocytes and mesenchymal stem cells. Seed cells activity plays a key role in the regeneration of functional cartilage tissue. However, seed cells undergo undesirable changes after in vitro processing procedures, such as degeneration of cartilage cells and induced hypertrophy of mesenchymal stem cells, which hinder cartilage tissue engineering. Compared to monoculture, which does not mimic the in vivo cellular environment, co-culture technology provides a more realistic microenvironment in terms of various physical, chemical, and biological factors. Co-culture technology is used in cartilage tissue engineering to overcome obstacles related to the degeneration of seed cells, and shows promise for cartilage regeneration and repair. In this review, we focus first on existing co-culture systems for cartilage tissue engineering and related fields, and discuss the conditions and mechanisms thereof. This is followed by methods for optimizing seed cell co-culture conditions to generate functional neo-cartilage tissue, which will lead to a new era in cartilage tissue engineering. © 2017 Wiley Periodicals, Inc.

The in vitro biocompatibility of d-(+) raffinose modified chitosan: Two-dimensional and three-dimensional systems for culturing of horse articular chondrocytes.

Science.gov (United States)

De Angelis, Elena; Ravanetti, Francesca; Martelli, Paolo; Cacchioli, Antonio; Ivanovska, Ana; Corradi, Attilio; Nasi, Sonia; Bianchera, Annalisa; Passeri, Benedetta; Canelli, Elena; Bettini, Ruggero; Borghetti, Paolo

2017-12-01

The present study investigated the biocompatibility of chitosan films and scaffolds modified with d-(+)raffinose and their capability to support the growth and maintenance of the differentiation of articular chondrocytes in vitro. Primary equine articular chondrocytes were cultured on films and scaffolds of modified d-(+) raffinose chitosan. Their behavior was compared to that of chondrocytes grown in conventional bi- and three-dimensional culture systems, such as micromasses and alginate beads. Chitosan films maintained the phenotype of differentiated chondrocytes (typical round morphology) and sustained the synthesis of cartilaginous extracellular matrix (ECM), even at 4weeks of culture. Indeed, starting from 2weeks of culture, chondrocytes seeded on chitosan scaffolds were able to penetrate the surface pores and to colonize the internal matrix. Moreover they produced ECM expressing the genes of typical chondrocytes differentiation markers such as collagen II and aggrecan. In conclusion, chitosan modified with d-raffinose represents an ideal support for chondrocyte adhesion, proliferation and for the maintenance of cellular phenotypic and genotypic differentiation. This novel biomaterial could potentially be a reliable support for the re-differentiation of dedifferentiated chondrocytes. Copyright © 2017 Elsevier Ltd. All rights reserved.

Preparation of three-dimensional macroporous chitosan-gelatin B microspheres and HepG2-cell culture.

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Huang, Fang; Cui, Long; Peng, Cheng-Hong; Wu, Xu-Bo; Han, Bao-San; Dong, Ya-Dong

2016-12-01

Chitosan-gelatin B microspheres with an open, interconnected, highly macroporous (100-200 µm) structure were prepared via a three-step protocol combining freeze-drying with an electrostatic and ionic cross-linking method. Saturated tripolyphosphate ethanol solution (85% ethanol) was chosen as the crosslinking agent to prevent destruction of the porous structure and to improve the biostability of the chitosan-gelatin B microspheres, with N-(3-dimethylaminopropyl)-N'-ethyl-carbodiimide/N-hydroxysuccinimide as a second crosslinking agent to react with gelatin A and fixed chitosan-gelatin B microspheres to attain improved biocompatibility. Water absorption of the three-dimensional macroporous chitosan-gelatin B microspheres (3D-P-CGMs) was 12.84, with a porosity of 85.45%. In vitro lysozyme degradation after 1, 3, 5, 7, 10, 14, and 21 days showed improved biodegradation in the 3D-P-CGMs. The morphology of human hepatoma cell lines (HepG2 cells) cultured on the 3D-P-CGMs was spherical, unlike that of cells cultured under traditional two-dimensional conditions. Scanning electron microscopy and paraffin sections were used to confirm the porous structure of the 3D-P-CGMs. HepG2 cells were able to migrate inside through the pore. Cell proliferation and levels of albumin and lactate dehydrogenase suggested that the 3D-P-CGMs could provide a larger specific surface area and an appropriate microenvironment for cell growth and survival. Hence, the 3D-P-CGMs are eminently suitable as macroporous scaffolds for cell cultures in tissue engineering and cell carrier studies. Copyright © 2014 John Wiley & Sons, Ltd. Copyright © 2014 John Wiley & Sons, Ltd.

Gastric tissue biopsy and culture

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... symptoms may include: Loss of appetite or weight loss Nausea and vomiting Pain in the upper part of the belly Black stools Vomiting blood or coffee ground-like material A gastric tissue biopsy and culture can help detect: Cancer Infections, most commonly Helicobacter ...

Three-Dimensional Microstructure of Biological Tissues during Freezing and Thawing

Science.gov (United States)

Ishiguro, Hiroshi; Horimizu, Takashi; Kataori, Akinobu; Kajigaya, Hiroshi

Three-dimensional behavior of ice crystals and cells during the freezing and thawing of biological tissues was investigated microscopically in real time by using a confocal laser scanning microscope(CLSM) and a fluorescent dye, acridine orange (AO). Fresh tender meat (2nd pectoral muscles) of chicken was stained with the AO in physiological saline to distinguish ice crystals and cells by their different colors, and then frozen and thawed under two different thermal protocols: a) slow-cooling and rapid-warming and b) rapid-cooling and rapid-warming. The CLSM noninvasively produced optical tomograms of the tissues to clarify the pattern of freezing, morphology of ice crystals in the tissues, and the interaction between ice crystals and cells. Also, the tissues were morphologically investigated by pathological means after the freezing and thawing. Typical freezing pattern during the slow-cooling was extracellular-freezing, and those during the rapid-cooling were extracellular-freezing and intracellular freezing with a lot of fine ice crystals in the cells. Cracks caused by the extracellular and intracellular ice crystals remained in the muscle tissues after the thawing. The results obtained by using the CLSM/dye method were consistent with pathologically morphological changes in the tissues through freezing and thawing.

Improved Diagnosis of Prosthetic Joint Infection by Culturing Periprosthetic Tissue Specimens in Blood Culture Bottles

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Trisha N. Peel

2016-01-01

Full Text Available Despite known low sensitivity, culture of periprosthetic tissue specimens on agars and in broths is routine. Culture of periprosthetic tissue samples in blood culture bottles (BCBs is potentially more convenient, but it has been evaluated in a limited way and has not been widely adopted. The aim of this study was to compare the sensitivity and specificity of inoculation of periprosthetic tissue specimens into blood culture bottles with standard agar and thioglycolate broth culture, applying Bayesian latent class modeling (LCM in addition to applying the Infectious Diseases Society of America (IDSA criteria for prosthetic joint infection. This prospective cohort study was conducted over a 9-month period (August 2013 to April 2014 at the Mayo Clinic, Rochester, MN, and included all consecutive patients undergoing revision arthroplasty. Overall, 369 subjects were studied; 117 (32% met IDSA criteria for prosthetic joint infection, and 82% had late chronic infection. Applying LCM, inoculation of tissues into BCBs was associated with a 47% improvement in sensitivity compared to the sensitivity of conventional agar and broth cultures (92.1 versus 62.6%, respectively; this magnitude of change was similar when IDSA criteria were applied (60.7 versus 44.4%, respectively; P = 0.003. The time to microorganism detection was shorter with BCBs than with standard media (P < 0.0001, with aerobic and anaerobic BCBs yielding positive results within a median of 21 and 23 h, respectively. Results of our study demonstrate that the semiautomated method of periprosthetic tissue culture in blood culture bottles is more sensitive than and as specific as agar and thioglycolate broth cultures and yields results faster.

Fabrication of cell-benign inverse opal hydrogels for three-dimensional cell culture.

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Im, Pilseon; Ji, Dong Hwan; Kim, Min Kyung; Kim, Jaeyun

2017-05-15

Inverse opal hydrogels (IOHs) for cell culture were fabricated and optimized using calcium-crosslinked alginate microbeads as sacrificial template and gelatin as a matrix. In contrast to traditional three-dimensional (3D) scaffolds, the gelatin IOHs allowed the utilization of both the macropore surface and inner matrix for cell co-culture. In order to remove templates efficiently for the construction of 3D interconnected macropores and to maintain high cell viability during the template removal process using EDTA solution, various factors in fabrication, including alginate viscosity, alginate concentration, alginate microbeads size, crosslinking calcium concentration, and gelatin network density were investigated. Low viscosity alginate, lower crosslinking calcium ion concentration, and lower concentration of alginate and gelatin were found to obtain high viability of cells encapsulated in the gelatin matrix after removal of the alginate template by EDTA treatment by allowing rapid dissociation and diffusion of alginate polymers. Based on the optimized fabrication conditions, gelatin IOHs showed good potential as a cell co-culture system, applicable to tissue engineering and cancer research. Copyright © 2017 Elsevier Inc. All rights reserved.

Versatile electrochemial sensor for tissue culturing and sample handling

DEFF Research Database (Denmark)

Bakmand, Tanya; Kwasny, Dorota; Al Atraktchi, Fatima Al-Zahraa

2014-01-01

Culturing of organtypic brain tissues is a routine procedure in neural research. The visual inspection of the medium is the only way of determining the state of the tissue. At the end of culturing, post-processing techniques such as HPLC can be used to measure the concentration of the secreted...

Application of cell co-culture system to study fat and muscle cells.

Science.gov (United States)

Pandurangan, Muthuraman; Hwang, Inho

2014-09-01

Animal cell culture is a highly complex process, in which cells are grown under specific conditions. The growth and development of these cells is a highly unnatural process in vitro condition. Cells are removed from animal tissues and artificially cultured in various culture vessels. Vitamins, minerals, and serum growth factors are supplied to maintain cell viability. Obtaining result homogeneity of in vitro and in vivo experiments is rare, because their structure and function are different. Living tissues have highly ordered complex architecture and are three-dimensional (3D) in structure. The interaction between adjacent cell types is quite distinct from the in vitro cell culture, which is usually two-dimensional (2D). Co-culture systems are studied to analyze the interactions between the two different cell types. The muscle and fat co-culture system is useful in addressing several questions related to muscle modeling, muscle degeneration, apoptosis, and muscle regeneration. Co-culture of C2C12 and 3T3-L1 cells could be a useful diagnostic tool to understand the muscle and fat formation in animals. Even though, co-culture systems have certain limitations, they provide a more realistic 3D view and information than the individual cell culture system. It is suggested that co-culture systems are useful in evaluating the intercellular communication and composition of two different cell types.

Cytoskeletal proteins from human skin fibroblasts, peripheral blood leukocytes, and a lymphoblastoid cell line compared by two-dimensional gel electrophoresis

International Nuclear Information System (INIS)

Giometti, C.S.; Willard, K.E.; Anderson, N.L.

1982-01-01

Differences in proteins between cells grown as suspension cultures and those grown as attached cultures were studied by comparing the proteins of detergent-resistant cytoskeletons prepared from peripheral blood leukocytes and a lymphoblastoid cell line (GM607) (both grown as suspension cultures) and those of human skin fibroblasts (grown as attached cultures) by two-dimensional gel electrophoresis. The major cytoskeletal proteins of the leukocytes were also present in the protein pattern of GM607 cytoskeletons. In contrast, the fibroblast cytoskeletal protein pattern contained four groups of proteins that differed from the patterns of the leukocytes and GM607. In addition, surface labeling of GM607 and human fibroblasts with 125 I demonstrated that substantial amounts of vimentin and actin are exposed at the surface of the attached fibroblasts, but there is little evidence of similar exposure at the surface of the suspension-grown GM607. These results demonstrate some differences in cytoskeletal protein composition between different types of cells could be related to their ability or lack of ability to grow as attached cells in tissue culture

The consensus in the two-feature two-state one-dimensional Axelrod model revisited

International Nuclear Information System (INIS)

Biral, Elias J P; Tilles, Paulo F C; Fontanari, José F

2015-01-01

The Axelrod model for the dissemination of culture exhibits a rich spatial distribution of cultural domains, which depends on the values of the two model parameters: F, the number of cultural features and q, the common number of states each feature can assume. In the one-dimensional model with F = q = 2, which is closely related to the constrained voter model, Monte Carlo simulations indicate the existence of multicultural absorbing configurations in which at least one macroscopic domain coexist with a multitude of microscopic ones in the thermodynamic limit. However, rigorous analytical results for the infinite system starting from the configuration where all cultures are equally likely show convergence to only monocultural or consensus configurations. Here we show that this disagreement is due simply to the order that the time-asymptotic limit and the thermodynamic limit are taken in the simulations. In addition, we show how the consensus-only result can be derived using Monte Carlo simulations of finite chains. (paper)

The consensus in the two-feature two-state one-dimensional Axelrod model revisited

Science.gov (United States)

Biral, Elias J. P.; Tilles, Paulo F. C.; Fontanari, José F.

2015-04-01

The Axelrod model for the dissemination of culture exhibits a rich spatial distribution of cultural domains, which depends on the values of the two model parameters: F, the number of cultural features and q, the common number of states each feature can assume. In the one-dimensional model with F = q = 2, which is closely related to the constrained voter model, Monte Carlo simulations indicate the existence of multicultural absorbing configurations in which at least one macroscopic domain coexist with a multitude of microscopic ones in the thermodynamic limit. However, rigorous analytical results for the infinite system starting from the configuration where all cultures are equally likely show convergence to only monocultural or consensus configurations. Here we show that this disagreement is due simply to the order that the time-asymptotic limit and the thermodynamic limit are taken in the simulations. In addition, we show how the consensus-only result can be derived using Monte Carlo simulations of finite chains.

Three-dimensional reconstruction of colorectal tumors from serial tissue sections by computer graphics: a preliminary study.

Science.gov (United States)

Kikuchi, S; Matsuzaki, H; Kondo, K; Ohtani, Y; Ihara, A; Hiki, Y; Kakita, A; Kuwao, S

2000-01-01

We present herein the three-dimensional reconstruction of colorectal tumors, with particular reference to growth pattern into each layer of the colorectal wall, and measurement of tumor volume and surface area. Conventional tissue section images of colorectal tumors were analyzed using a computer graphics analysis program. The two-dimensional extent of invasion by each tumor into each layer of intestinal wall were determined from the images of each section. Based on data from multiple sections, tumor and surrounding normal tissue layers were reconstructed three-dimensionally, and volume and surface area of the tumors were determined. Using this technique, three-dimensional morphology of tumor and tumor progression into colorectal wall could be determined. Volume and surface area of the colon tumor were 4871 mm3 and 1741 mm2, respectively. Volume and surface area of the rectal tumor were 1090 mm3 and 877 mm2, respectively. This technique may provide a new approach for pathological analysis of colorectal carcinoma.

Comparison of protein patterns after two-dimensional gel electrophoresis from leaves of in vitro cultures and seedlings of Rubus chamaemorus L.

Directory of Open Access Journals (Sweden)

Barbara Thiem

2014-01-01

Full Text Available Proteins from leaves of Rubus chamaemorus propagated in vitro were subjected to miniaturized 2-D electrophoresis. The 2-DE patterns of proteins showed qualitative differences between plants propagated in vitro and control seedlings. More proteins of a high molecular weight were observed in leaves of plants from in vitro culture. A two-dimensional map of proteins from leaves provides detailed data concerning both polymorphism and protein patterns of this species. This makes it possible to start constructing a protein map of R. chamaemorus. The reasons for qualitative differences are discussed.

Human umbilical cord mesenchymal stromal cells exhibit immature nucleus pulposus cell phenotype in a laminin-rich pseudo-three-dimensional culture system.

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Chon, Brian H; Lee, Esther J; Jing, Liufang; Setton, Lori A; Chen, Jun

2013-10-02

Cell supplementation to the herniated or degenerated intervertebral disc (IVD) is a potential strategy to promote tissue regeneration and slow disc pathology. Human umbilical cord mesenchymal stromal cells (HUCMSCs) - originating from the Wharton's jelly - remain an attractive candidate for such endeavors with their ability to differentiate into multiple lineages. Previously, mesenchymal stem cells (MSCs) have been studied as a potential source for disc tissue regeneration. However, no studies have demonstrated that MSCs can regenerate matrix with unique characteristics matching that of immature nucleus pulposus (NP) tissues of the IVD. In our prior work, immature NP cells were found to express specific laminin isoforms and laminin-binding receptors that may serve as phenotypic markers for evaluating MSC differentiation to NP-like cells. The goal of this study is to evaluate these markers and matrix synthesis for HUCMSCs cultured in a laminin-rich pseudo-three-dimensional culture system. HUCMSCs were seeded on top of Transwell inserts pre-coated with Matrigel™, which contained mainly laminin-111. Cells were cultured under hypoxia environment with three differentiation conditions: NP differentiation media (containing 2.5% Matrigel™ solution to provide for a pseudo-three-dimensional laminin culture system) with no serum, or the same media supplemented with either insulin-like growth factor-1 (IGF-1) or transforming growth factor-β1 (TGF-β1). Cell clustering behavior, matrix production and the expression of NP-specific laminin and laminin-receptors were evaluated at days 1, 7, 13 and 21 of culture. Data show that a pseudo-three-dimensional culture condition (laminin-1 rich) promoted HUCMSC differentiation under no serum conditions. Starting at day 1, HUCMSCs demonstrated a cell clustering morphology similar to that of immature NP cells in situ and that observed for primary immature NP cells within the similar laminin-rich culture system (prior study

A Simplified Method for Three-Dimensional (3-D Ovarian Tissue Culture Yielding Oocytes Competent to Produce Full-Term Offspring in Mice.

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Carolyn M Higuchi

Full Text Available In vitro growth of follicles is a promising technology to generate large quantities of competent oocytes from immature follicles and could expand the potential of assisted reproductive technologies (ART. Isolated follicle culture is currently the primary method used to develop and mature follicles in vitro. However, this procedure typically requires complicated, time-consuming procedures, as well as destruction of the normal ovarian microenvironment. Here we describe a simplified 3-D ovarian culture system that can be used to mature multilayered secondary follicles into antral follicles, generating developmentally competent oocytes in vitro. Ovaries recovered from mice at 14 days of age were cut into 8 pieces and placed onto a thick Matrigel drop (3-D culture for 10 days of culture. As a control, ovarian pieces were cultured on a membrane filter without any Matrigel drop (Membrane culture. We also evaluated the effect of activin A treatment on follicle growth within the ovarian pieces with or without Matrigel support. Thus we tested four different culture conditions: C (Membrane/activin-, A (Membrane/activin+, M (Matrigel/activin-, and M+A (Matrigel/activin+. We found that the cultured follicles and oocytes steadily increased in size regardless of the culture condition used. However, antral cavity formation occurred only in the follicles grown in the 3-D culture system (M, M+A. Following ovarian tissue culture, full-grown GV oocytes were isolated from the larger follicles to evaluate their developmental competence by subjecting them to in vitro maturation (IVM and in vitro fertilization (IVF. Maturation and fertilization rates were higher using oocytes grown in 3-D culture (M, M+A than with those grown in membrane culture (C, A. In particular, activin A treatment further improved 3-D culture (M+A success. Following IVF, two-cell embryos were transferred to recipients to generate full-term offspring. In summary, this simple and easy 3-D ovarian

Culture methods of allograft musculoskeletal tissue samples in Australian bacteriology laboratories.

Science.gov (United States)

Varettas, Kerry

2013-12-01

Samples of allograft musculoskeletal tissue are cultured by bacteriology laboratories to determine the presence of bacteria and fungi. In Australia, this testing is performed by 6 TGA-licensed clinical bacteriology laboratories with samples received from 10 tissue banks. Culture methods of swab and tissue samples employ a combination of solid agar and/or broth media to enhance micro-organism growth and maximise recovery. All six Australian laboratories receive Amies transport swabs and, except for one laboratory, a corresponding biopsy sample for testing. Three of the 6 laboratories culture at least one allograft sample directly onto solid agar. Only one laboratory did not use a broth culture for any sample received. An international literature review found that a similar combination of musculoskeletal tissue samples were cultured onto solid agar and/or broth media. Although variations of allograft musculoskeletal tissue samples, culture media and methods are used in Australian and international bacteriology laboratories, validation studies and method evaluations have challenged and supported their use in recovering fungi and aerobic and anaerobic bacteria.

Three-Dimensional Geometry of Collagenous Tissues by Second Harmonic Polarimetry.

Science.gov (United States)

Reiser, Karen; Stoller, Patrick; Knoesen, André

2017-06-01

Collagen is a biological macromolecule capable of second harmonic generation, allowing label-free detection in tissues; in addition, molecular orientation can be determined from the polarization dependence of the second harmonic signal. Previously we reported that in-plane orientation of collagen fibrils could be determined by modulating the polarization angle of the laser during scanning. We have now extended this method so that out-of-plane orientation angles can be determined at the same time, allowing visualization of the 3-dimensional structure of collagenous tissues. This approach offers advantages compared with other methods for determining out-of-plane orientation. First, the orientation angles are directly calculated from the polarimetry data obtained in a single scan, while other reported methods require data from multiple scans, use of iterative optimization methods, application of fitting algorithms, or extensive post-optical processing. Second, our method does not require highly specialized instrumentation, and thus can be adapted for use in almost any nonlinear optical microscopy setup. It is suitable for both basic and clinical applications. We present three-dimensional images of structurally complex collagenous tissues that illustrate the power of such 3-dimensional analyses to reveal the architecture of biological structures.

Metabolic Profile of Pancreatic Acinar and Islet Tissue in Culture

Science.gov (United States)

Suszynski, Thomas M.; Mueller, Kathryn; Gruessner, Angelika C.; Papas, Klearchos K.

2016-01-01

The amount and condition of exocrine impurities may affect the quality of islet preparations especially during culture. In this study, the objective was to determine the oxygen demandand viability of islet and acinar tissue post-isolation and whether they change disproportionately while in culture. We compare the OCR normalized to DNA (OCR/DNA, a measure of fractional viability in units nmol/min/mg DNA), and percent change in OCR and DNA recoveries between adult porcine islet and acinar tissue from the same preparation (paired) over a 6-9 days of standard culture. Paired comparisons were done to quantify differences in OCR/DNA between islet and acinar tissue from the same preparation, at specified time points during culture; the mean (± standard error) OCR/DNA was 74.0 (±11.7) units higher for acinar (vs. islet) tissue on the day of isolation (n=16, p<0.0001), but 25.7 (±9.4) units lower after 1 day (n=8, p=0.03), 56.6 (±11.5) units lower after 2 days (n=12, p=0.0004), and 65.9 (±28.7) units lower after 8 days (n=4, p=0.2) in culture. DNA and OCR recoveries decreased at different rates for acinar versus islet tissue over 6-9 days in culture (n=6). DNA recovery decreased to 24±7% for acinar and 75±8% for islets (p=0.002). Similarly, OCR recovery decreased to 16±3% for acinar and remained virtually constant for islets (p=0.005). Differences in the metabolic profile of acinarand islet tissue should be considered when culturing impure islet preparations. OCR-based measurements may help optimize pre-IT culture protocols. PMID:25131082

Two-dimensional electrophoretic analysis of nuclear matrix proteins in human colon adenocarcinoma.

Science.gov (United States)

Toumpanaki, A; Baltatzis, G E; Gaitanarou, E; Seretis, E; Toumpanakis, C; Aroni, K; Kittas, Christos; Voloudakis-Baltatzis, I E

2009-01-01

The aim of the present study was to observe possible qualitative and quantitative expression differences between nuclear matrix proteins (NMPs) of human colon adenocarcinoma and their mirror biopsies, using the technique of two-dimensional gel electrophoresis, in order to identify the existence of specific NMP fingerprints for colon cancer. Colon tissues were examined ultrastructurally and NMPs were isolated biochemically, by serial extraction of lipids, soluble proteins, DNA, RNA, and intermediate filaments and were separated according to their isoelectric point (pI) and their molecular weight (MW) by high-resolution two-dimensional electrophoresis (2D). By comparing the 2D electropherograms of colon cancer tissues and mirror biopsy tissues we observed qualitative and quantitative expression differences between their NMPs but also a differentiation of NMP composition between the stages of malignancy. Moreover, despite the similarities between mirror biopsy samples, a highlight percentage of exception was observed. Electrophoretic results provided in this study demonstrated that the examined NMPs could be further investigated as potential markers for detection of colorectal cancer in an early stage, for the assessment of the disease progression, as well as useful tools for individual therapy and for preventing a possible recurrence of cancer and metastasis.

Revision washout decreases implant capsule tissue culture positivity: a multicenter study.

Science.gov (United States)

Henry, Gerard D; Carson, Culley C; Wilson, Steven K; Wiygul, Jeremy; Tornehl, Chris; Cleves, Mario A; Simmons, Caroline J; Donatucci, Craig F

2008-01-01

Positive cultures, visible biofilm and confocal micrography confirm bacterial presence on clinically uninfected inflatable penile prostheses at revision surgery. Salvage irrigation has been proved to rescue patients with clinically infected inflatable penile prostheses. Similar washout at revision for noninfectious reasons significantly lowers subsequent infection rates. We investigated a larger series of patients for positive culture rates and evaluated implant capsule tissue culture rates before and after revision washout. At 4 institutions a total of 148 patients with inflatable penile prostheses underwent revision surgery for noninfectious reasons between June 2001 and September 2005. Swab cultures of the fluid around the pump and visible biofilm were obtained. Also, in 65 patients a wedge of tissue from the capsule that forms around the pump was cultured. After implant removal revision washout of the implant spaces was performed and a second wedge of tissue was cultured. Of the 148 patients 97 (66%) had positive bacterial swab cultures of the fluid around the pump or biofilm. A total of 124 isolates were cultured. Of the 65 implant capsule tissue cultures obtained before washout 28 (43%) were positive for bacteria, while 16 (25%) obtained after revision washout were positive. Positive cultures and visible bacterial biofilm are present on clinically uninfected inflatable penile prostheses at revision surgery in most patients. Revision washout appears to decrease the bacterial load on implant capsule tissue at revision surgery of inflatable penile prostheses for noninfectious reasons.

Canine osteosarcoma karyotypes from an original tumor, its metastasis, and tumor cells in tissue culture

International Nuclear Information System (INIS)

Taylor, N.; Shifrine, M.; Wolf, H.G.; Trommershausen-Smith, A.

1975-01-01

Radiation-induced osteosarcoma, its metastasis, and cells grown in tissue culture were karyotyped. Both hypodiploid and hyperdiploid stem lines were observed. The hypodiploid line contained 45-55 chromosomes with 10 to 15 abnormal metacentric and submetacentric chromosomes and one subtelocentric marker. The hyperdiploid line contained 90 to 105 chromosomes with 20 to 30 abnormal metacentric and submetacentric chromosomes with two subtelocentric markers. Karyotypic analysis can be used to monitor osteosarcomas maintained in tissue culture

Equivalence of two-dimensional gravities

International Nuclear Information System (INIS)

Mohammedi, N.

1990-01-01

The authors find the relationship between the Jackiw-Teitelboim model of two-dimensional gravity and the SL(2,R) induced gravity. These are shown to be related to a two-dimensional gauge theory obtained by dimensionally reducing the Chern-Simons action of the 2 + 1 dimensional gravity. The authors present an explicit solution to the equations of motion of the auxiliary field of the Jackiw-Teitelboim model in the light-cone gauge. A renormalization of the cosmological constant is also given

The autologus graft of epithelial tissue culture

Directory of Open Access Journals (Sweden)

Minaee B

1999-08-01

Full Text Available With the intention of research about culture and autologus graft of epithelial tissue we used 4 french Albino Rabbits with an average age of 2 months. After reproduction on the support in EMEM (Eagle's Minimum Essential Medium we used this for graft after 4 weeks. This region which grafted total replaced. After fixation of this sample and passing them through various process, histological sections were prepared. These sections were stained with H & E and masson's trichrome and studied by light microscope. We succeeded in graft. We hope in the near future by using the method of epithelium tissue culture improving to treat burned patients.

Two-dimensional metamaterial optics

International Nuclear Information System (INIS)

Smolyaninov, I I

2010-01-01

While three-dimensional photonic metamaterials are difficult to fabricate, many new concepts and ideas in the metamaterial optics can be realized in two spatial dimensions using planar optics of surface plasmon polaritons. In this paper we review recent progress in this direction. Two-dimensional photonic crystals, hyperbolic metamaterials, and plasmonic focusing devices are demonstrated and used in novel microscopy and waveguiding schemes

Real-time three-dimensional ultrasound-assisted axillary plexus block defines soft tissue planes.

Science.gov (United States)

Clendenen, Steven R; Riutort, Kevin; Ladlie, Beth L; Robards, Christopher; Franco, Carlo D; Greengrass, Roy A

2009-04-01

Two-dimensional (2D) ultrasound is commonly used for regional block of the axillary brachial plexus. In this technical case report, we described a real-time three-dimensional (3D) ultrasound-guided axillary block. The difference between 2D and 3D ultrasound is similar to the difference between plain radiograph and computer tomography. Unlike 2D ultrasound that captures a planar image, 3D ultrasound technology acquires a 3D volume of information that enables multiple planes of view by manipulating the image without movement of the ultrasound probe. Observation of the brachial plexus in cross-section demonstrated distinct linear hyperechoic tissue structures (loose connective tissue) that initially inhibited the flow of the local anesthesia. After completion of the injection, we were able to visualize the influence of arterial pulsation on the spread of the local anesthesia. Possible advantages of this novel technology over current 2D methods are wider image volume and the capability to manipulate the planes of the image without moving the probe.

Liarozole inhibits transforming growth factor-β3–mediated extracellular matrix formation in human three-dimensional leiomyoma cultures

Science.gov (United States)

Levy, Gary; Malik, Minnie; Britten, Joy; Gilden, Melissa; Segars, James; Catherino, William H.

2014-01-01

Objective To investigate the impact of liarozole on transforming growth factor-β3 (TGF-β3) expression, TGF-β3 controlled profibrotic cytokines, and extracellular matrix formation in a three-dimensional (3D) leiomyoma model system. Design Molecular and immunohistochemical analysis in a cell line evaluated in a three-dimensional culture. Setting Laboratory study. Patient(s) None. Intervention(s) Treatment of leiomyoma and myometrial cells with liarozole and TGF-β3 in a three-dimensional culture system. Main Outcome Measure(s) Quantitative real-time reverse-transcriptase polymerase chain reaction and Western blotting to assess fold gene and protein expression of TGF-β3 and TGF-β3 regulated fibrotic cytokines: collagen 1A1 (COL1A1), fibronectin, and versican before and after treatment with liarozole, and confirmatory immunohistochemical stains of treated three-dimensional cultures. Result(s) Both TGF-β3 gene and protein expression were elevated in leiomyoma cells compared with myometrium in two-dimensional and 3D cultures. Treatment with liarozole decreased TGF-β3 gene and protein expression. Extracellular matrix components versican, COL1A1, and fibronectin were also decreased by liarozole treatment in 3D cultures. Treatment of 3D cultures with TGF-β3 increased gene expression and protein production of COL1A1, fibronectin, and versican. Conclusion(s) Liarozole decreased TGF-β3 and TGF-β3–mediated extracellular matrix expression in a 3D uterine leiomyoma culture system. PMID:24825427

Tissue culture-induced genetic and epigenetic alterations in rice pure-lines, F1 hybrids and polyploids.

Science.gov (United States)

Wang, Xiaoran; Wu, Rui; Lin, Xiuyun; Bai, Yan; Song, Congdi; Yu, Xiaoming; Xu, Chunming; Zhao, Na; Dong, Yuzhu; Liu, Bao

2013-05-05

Genetic and epigenetic alterations can be invoked by plant tissue culture, which may result in heritable changes in phenotypes, a phenomenon collectively termed somaclonal variation. Although extensive studies have been conducted on the molecular nature and spectrum of tissue culture-induced genomic alterations, the issue of whether and to what extent distinct plant genotypes, e.g., pure-lines, hybrids and polyploids, may respond differentially to the tissue culture condition remains poorly understood. We investigated tissue culture-induced genetic and epigenetic alterations in a set of rice genotypes including two pure-lines (different subspecies), a pair of reciprocal F1 hybrids parented by the two pure-lines, and a pair of reciprocal tetraploids resulted from the hybrids. Using two molecular markers, amplified fragment length polymorphism (AFLP) and methylation-sensitive amplified polymorphism (MSAP), both genetic and DNA methylation alterations were detected in calli and regenerants from all six genotypes, but genetic alteration is more prominent than epigenetic alteration. While significant genotypic difference was observed in frequencies of both types of alterations, only genetic alteration showed distinctive features among the three types of genomes, with one hybrid (N/9) being exceptionally labile. Surprisingly, difference in genetic alteration frequencies between the pair of reciprocal F1 hybrids is much greater than that between the two pure-line subspecies. Difference also exists in the pair of reciprocal tetraploids, but is to a less extent than that between the hybrids. The steady-state transcript abundance of genes involved in DNA repair and DNA methylation was significantly altered in both calli and regenerants, and some of which were correlated with the genetic and/or epigenetic alterations. Our results, based on molecular marker analysis of ca. 1,000 genomic loci, document that genetic alteration is the major cause of somaclonal variation in rice

[Research progress of co-culture system for constructing vascularized tissue engineered bone].

Science.gov (United States)

Fu, Weili; Xiang, Zhou

2014-02-01

To review the research progress of the co-culture system for constructing vascularized tissue engineered bone. The recent literature concerning the co-culture system for constructing vascularized tissue engineered bone was reviewed, including the selection of osteogenic and endothelial lineages, the design and surface modification of scaffolds, the models and dimensions of the co-culture system, the mechanism, the culture conditions, and their application progress. The construction of vascularized tissue engineered bone is the prerequisite for their survival and further clinical application in vivo. Mesenchymal stem cells (owning the excellent osteogenic potential) and endothelial progenitor cells (capable of directional differentiation into endothelial cell) are considered as attractive cell types for the co-culture system to construct vascularized tissue engineered bone. The culture conditions need to be further optimized. Furthermore, how to achieve the clinical goals of minimal invasion and autologous transplantation also need to be further studied. The strategy of the co-culture system for constructing vascularized tissue engineered bone would have a very broad prospects for clinical application in future.

Improved Diagnosis of Prosthetic Joint Infection by Culturing Periprosthetic Tissue Specimens in Blood Culture Bottles.

Science.gov (United States)

Peel, Trisha N; Dylla, Brenda L; Hughes, John G; Lynch, David T; Greenwood-Quaintance, Kerryl E; Cheng, Allen C; Mandrekar, Jayawant N; Patel, Robin

2016-01-05

Despite known low sensitivity, culture of periprosthetic tissue specimens on agars and in broths is routine. Culture of periprosthetic tissue samples in blood culture bottles (BCBs) is potentially more convenient, but it has been evaluated in a limited way and has not been widely adopted. The aim of this study was to compare the sensitivity and specificity of inoculation of periprosthetic tissue specimens into blood culture bottles with standard agar and thioglycolate broth culture, applying Bayesian latent class modeling (LCM) in addition to applying the Infectious Diseases Society of America (IDSA) criteria for prosthetic joint infection. This prospective cohort study was conducted over a 9-month period (August 2013 to April 2014) at the Mayo Clinic, Rochester, MN, and included all consecutive patients undergoing revision arthroplasty. Overall, 369 subjects were studied; 117 (32%) met IDSA criteria for prosthetic joint infection, and 82% had late chronic infection. Applying LCM, inoculation of tissues into BCBs was associated with a 47% improvement in sensitivity compared to the sensitivity of conventional agar and broth cultures (92.1 versus 62.6%, respectively); this magnitude of change was similar when IDSA criteria were applied (60.7 versus 44.4%, respectively; P = 0.003). The time to microorganism detection was shorter with BCBs than with standard media (P Prosthetic joint infections are a devastating complication of arthroplasty surgery. Despite this, current microbiological techniques to detect and diagnose infections are imperfect. This study examined a new approach to diagnosing infections, through the inoculation of tissue samples from around the prosthetic joint into blood culture bottles. This study demonstrated that, compared to current laboratory practices, this new technique increased the detection of infection. These findings are important for patient care to allow timely and accurate diagnosis of infection. Copyright © 2016 Peel et al.

A review of evolution of electrospun tissue engineering scaffold: From two dimensions to three dimensions.

Science.gov (United States)

Ngadiman, Nor Hasrul Akhmal; Noordin, M Y; Idris, Ani; Kurniawan, Denni

2017-07-01

The potential of electrospinning process to fabricate ultrafine fibers as building blocks for tissue engineering scaffolds is well recognized. The scaffold construct produced by electrospinning process depends on the quality of the fibers. In electrospinning, material selection and parameter setting are among many factors that contribute to the quality of the ultrafine fibers, which eventually determine the performance of the tissue engineering scaffolds. The major challenge of conventional electrospun scaffolds is the nature of electrospinning process which can only produce two-dimensional electrospun mats, hence limiting their applications. Researchers have started to focus on overcoming this limitation by combining electrospinning with other techniques to fabricate three-dimensional scaffold constructs. This article reviews various polymeric materials and their composites/blends that have been successfully electrospun for tissue engineering scaffolds, their mechanical properties, and the various parameters settings that influence the fiber morphology. This review also highlights the secondary processes to electrospinning that have been used to develop three-dimensional tissue engineering scaffolds as well as the steps undertaken to overcome electrospinning limitations.

Tumor tissue slice cultures as a platform for analyzing tissue-penetration and biological activities of nanoparticles.

Science.gov (United States)

Merz, Lea; Höbel, Sabrina; Kallendrusch, Sonja; Ewe, Alexander; Bechmann, Ingo; Franke, Heike; Merz, Felicitas; Aigner, Achim

2017-03-01

The success of therapeutic nanoparticles depends, among others, on their ability to penetrate a tissue for actually reaching the target cells, and their efficient cellular uptake in the context of intact tissue and stroma. Various nanoparticle modifications have been implemented for altering physicochemical and biological properties. Their analysis, however, so far mainly relies on cell culture experiments which only poorly reflect the in vivo situation, or is based on in vivo experiments that are often complicated by whole-body pharmacokinetics and are rather tedious especially when analyzing larger nanoparticle sets. For the more precise analysis of nanoparticle properties at their desired site of action, efficient ex vivo systems closely mimicking in vivo tissue properties are needed. In this paper, we describe the setup of organotypic tumor tissue slice cultures for the analysis of tissue-penetrating properties and biological activities of nanoparticles. As a model system, we employ 350μm thick slice cultures from different tumor xenograft tissues, and analyze modified or non-modified polyethylenimine (PEI) complexes as well as their lipopolyplex derivatives for siRNA delivery. The described conditions for tissue slice preparation and culture ensure excellent tissue preservation for at least 14days, thus allowing for prolonged experimentation and analysis. When using fluorescently labeled siRNA for complex visualization, fluorescence microscopy of cryo-sectioned tissue slices reveals different degrees of nanoparticle tissue penetration, dependent on their surface charge. More importantly, the determination of siRNA-mediated knockdown efficacies of an endogenous target gene, the oncogenic survival factor Survivin, reveals the possibility to accurately assess biological nanoparticle activities in situ, i.e. in living cells in their original environment. Taken together, we establish tumor (xenograft) tissue slices for the accurate and facile ex vivo assessment of

Three-Dimensional Bioprinting for Regenerative Dentistry and Craniofacial Tissue Engineering.

Science.gov (United States)

Obregon, F; Vaquette, C; Ivanovski, S; Hutmacher, D W; Bertassoni, L E

2015-09-01

Craniofacial tissues are organized with complex 3-dimensional (3D) architectures. Mimicking such 3D complexity and the multicellular interactions naturally occurring in craniofacial structures represents one of the greatest challenges in regenerative dentistry. Three-dimensional bioprinting of tissues and biological structures has been proposed as a promising alternative to address some of these key challenges. It enables precise manufacture of various biomaterials with complex 3D architectures, while being compatible with multiple cell sources and being customizable to patient-specific needs. This review describes different 3D bioprinting methods and summarizes how different classes of biomaterials (polymer hydrogels, ceramics, composites, and cell aggregates) may be used for 3D biomanufacturing of scaffolds, as well as craniofacial tissue analogs. While the fabrication of scaffolds upon which cells attach, migrate, and proliferate is already in use, printing of all the components that form a tissue (living cells and matrix materials together) to produce tissue constructs is still in its early stages. In summary, this review seeks to highlight some of the key advantages of 3D bioprinting technology for the regeneration of craniofacial structures. Additionally, it stimulates progress on the development of strategies that will promote the translation of craniofacial tissue engineering from the laboratory bench to the chair side. © International & American Associations for Dental Research 2015.

Growing B Lymphocytes in a Three-Dimensional Culture System

Science.gov (United States)

Wu, J. H. David; Bottaro, Andrea

2010-01-01

A three-dimensional (3D) culture system for growing long-lived B lymphocytes has been invented. The capabilities afforded by the system can be expected to expand the range of options for immunological research and related activities, including testing of immunogenicity of vaccine candidates in vitro, generation of human monoclonal antibodies, and immunotherapy. Mature lymphocytes, which are the effectors of adaptive immune responses in vertebrates, are extremely susceptible to apoptotic death, and depend on continuous reception of survival-inducing stimulation (in the forms of cytokines, cell-to-cell contacts, and antigen receptor signaling) from the microenvironment. For this reason, efforts to develop systems for long-term culture of functional, non-transformed and non-activated mature lymphocytes have been unsuccessful until now. The bone-marrow microenvironment supports the growth and differentiation of many hematopoietic lineages, in addition to B-lymphocytes. Primary bone-marrow cell cultures designed to promote the development of specific cell types in vitro are highly desirable experimental systems, amenable to manipulation under controlled conditions. However, the dynamic and complex network of stromal cells and insoluble matrix proteins is disrupted in prior plate- and flask-based culture systems, wherein the microenvironments have a predominantly two-dimensional (2D) character. In 2D bone-marrow cultures, normal B-lymphoid cells become progressively skewed toward precursor B-cell populations that do not retain a normal immunophenotype, and such mature B-lymphocytes as those harvested from the spleen or lymph nodes do not survive beyond several days ex vivo in the absence of mitogenic stimulation. The present 3D culture system is a bioreactor that contains highly porous artificial scaffolding that supports the long-term culture of bone marrow, spleen, and lymph-node samples. In this system, unlike in 2D culture systems, B-cell subpopulations developing

An in vitro 3D bone metastasis model by using a human bone tissue culture and human sex-related cancer cells.

Science.gov (United States)

Salamanna, Francesca; Borsari, Veronica; Brogini, Silvia; Giavaresi, Gianluca; Parrilli, Annapaola; Cepollaro, Simona; Cadossi, Matteo; Martini, Lucia; Mazzotti, Antonio; Fini, Milena

2016-11-22

One of the main limitations, when studying cancer-bone metastasis, is the complex nature of the native bone environment and the lack of reliable, simple, inexpensive models that closely mimic the biological processes occurring in patients and allowing the correct translation of results. To enhance the understanding of the mechanisms underlying human bone metastases and in order to find new therapies, we developed an in vitro three-dimensional (3D) cancer-bone metastasis model by culturing human breast or prostate cancer cells with human bone tissue isolated from female and male patients, respectively. Bone tissue discarded from total hip replacement surgery was cultured in a rolling apparatus system in a normoxic or hypoxic environment. Gene expression profile, protein levels, histological, immunohistochemical and four-dimensional (4D) micro-CT analyses showed a noticeable specificity of breast and prostate cancer cells for bone colonization and ingrowth, thus highlighting the species-specific and sex-specific osteotropism and the need to widen the current knowledge on cancer-bone metastasis spread in human bone tissues. The results of this study support the application of this model in preclinical studies on bone metastases and also follow the 3R principles, the guiding principles, aimed at replacing/reducing/refining (3R) animal use and their suffering for scientific purposes.

An exploration study to find important factors influencing on multi-dimensional organizational culture

Directory of Open Access Journals (Sweden)

Naser Azad

2013-08-01

Full Text Available This paper presents an empirical investigation to find important factors influencing multi-dimensional organizational culture. The proposed study designs a questionnaire in Likert scale consists of 21 questions, distributes it among 300 people who worked for different business units and collects 283 filled ones. Cronbach alpha is calculated as 0.799. In addition, Kaiser-Meyer-Olkin Measure of Sampling Adequacy and Approx. Chi-Square are 0.821 and 1395.74, respectively. The study has implemented principal component analysis and the results have indicated that there were four factors influencing organizational culture including, diversity in culture, connection based culture, integrated culture and structure of culture. In terms of diversity in culture, sensitivity to quality data and cultural flexibility are the most influential sub-factors while connection based marketing and relational satisfaction are two important sub-factors associated with diversity in culture. The study discusses other issues.

Quantifying the correlation between spatially defined oxygen gradients and cell fate in an engineered three-dimensional culture model

OpenAIRE

Ardakani, Amir G.; Cheema, Umber; Brown, Robert A.; Shipley, Rebecca J.

2014-01-01

A challenge in three-dimensional tissue culture remains the lack of quantitative information linking nutrient delivery and cellular distribution. Both in vivo and in vitro, oxygen is delivered by diffusion from its source (blood vessel or the construct margins). The oxygen level at a defined distance from its source depends critically on the balance of diffusion and cellular metabolism. Cells may respond to this oxygen environment through proliferation, death and chemotaxis, resulting in spat...

Tissue culture of surgically prepared temporalis fascia.

Science.gov (United States)

Walby, A P; Kerr, A G; Nevin, N C; Woods, G

1982-10-01

Temporalis fascia which is used to graft the tympanic membrane has been shown to be viable in tissue culture by a previous pilot study. This present study reports the effect on the viability of the fascia by scraping loose connective tissue from it and allowing it to dry. Pieces of fascia from 30 patients were each divided in 4 and prepared to give explants, fresh, fresh and scraped, dried, and dried and scraped. The fascia grew from 17 patients when cultured fresh, 5 when fresh and scraped, 1 when dried, and none when dried and scraped. These results are significantly different and show that the fascia is devitilized when prepared by the normal method for use in tympanoplasty.

Three-dimensional development of tensile pre-strained annulus fibrosus cells for tissue regeneration: An in-vitro study

Energy Technology Data Exchange (ETDEWEB)

Chuah, Yon Jin [School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Drive, Singapore 637459 (Singapore); Lee, Wu Chean [University Hospital Conventry & Warwickshire NHS Trust, Clifford Bridge Road, West Midlands CV2, 2DX (United Kingdom); Wong, Hee Kit [Department of Orthopedic Surgery, National University Health System, NUHS Tower Block Level 11, 1E Kent Ridge Road, Singapore 119228 (Singapore); Kang, Yuejun, E-mail: yuejun.kang@ntu.edu.sg [School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Drive, Singapore 637459 (Singapore); Hee, Hwan Tak, E-mail: HTHee@ntu.edu.sg [School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Drive, Singapore 637459 (Singapore); Pinnacle Spine & Scoliosis Centre, 3 Mount Elizabeth, Mount Elizabeth Medical Centre, #04-07, Singapore 228510 (Singapore); School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637459 (Singapore)

2015-02-01

Prior research has investigated the immediate response after application of tensile strain on annulus fibrosus (AF) cells for the past decade. Although mechanical strain can produce either catabolic or anabolic consequences to the cell monolayer, little is known on how to translate these findings into further tissue engineering applications. Till to date, the application and effect of tensile pre-strained cells to construct a three-dimensional (3D) AF tissue remains unknown. This study aims to investigate the effect of tensile pre-strained exposure of 1 to 24 h on the development of AF pellet culture for 3 weeks. Equibiaxial cyclic tensile strain was applied on AF monolayer cells over a period of 24 h, which was subsequently developed into a cell pellet. Investigation on cellular proliferation, phenotypic gene expression, and histological changes revealed that tensile pre-strain for 24 h had significant and lasting effect on the AF tissue development, with enhanced cell proliferation, and up-regulation of collagen type I, II, and aggrecan expression. Our results demonstrated the regenerative ability of AF cell pellets subjected to 24 h tensile pre-straining. Knowledge on the effects of tensile pre-strain exposure is necessary to optimize AF development for tissue reconstruction. Moreover, the tensile pre-strained cells may further be utilized in either cell therapy to treat mild disc degeneration disease, or the development of a disc construct for total disc replacement. - Highlights: • Establishment of tensile pre-strained cell line population for annulus development. • Tensile strain limits collagen gene expression declination in monolayer culture. • Tensile pre-strained cells up-regulate their matrix protein in 3D pellet culture.

From Microscale Devices to 3D Printing: Advances in Fabrication of 3D Cardiovascular Tissues

Science.gov (United States)

Borovjagin, Anton V.; Ogle, Brenda; Berry, Joel; Zhang, Jianyi

2016-01-01

Current strategies for engineering cardiovascular cells and tissues have yielded a variety of sophisticated tools for studying disease mechanisms, for development of drug therapies, and for fabrication of tissue equivalents that may have application in future clinical use. These efforts are motivated by the need to extend traditional two-dimensional (2D) cell culture systems into 3D to more accurately replicate in vivo cell and tissue function of cardiovascular structures. Developments in microscale devices and bioprinted 3D tissues are beginning to supplant traditional 2D cell cultures and pre-clinical animal studies that have historically been the standard for drug and tissue development. These new approaches lend themselves to patient-specific diagnostics, therapeutics, and tissue regeneration. The emergence of these technologies also carries technical challenges to be met before traditional cell culture and animal testing become obsolete. Successful development and validation of 3D human tissue constructs will provide powerful new paradigms for more cost effective and timely translation of cardiovascular tissue equivalents. PMID:28057791

Co-cultures and cell sheet engineering as relevant tools to improve the outcome of bone tissue engineering strategies

OpenAIRE

Pirraco, Rogério

2011-01-01

Taking into consideration the complex biology of bone tissue it is quite clear that the understanding of the cellular interactions that regulate the homeostasis and regeneration of this remarkable tissue is essential for a successful Tissue Engineering strategy. The in vitro study of these cellular interactions relies on co-culture systems, a tremendously useful methodology where two or more cell types are cultured at the same time. Such strategy increases the complexity of typ...

Three-dimensional alginate spheroid culture system of murine osteosarcoma.

Science.gov (United States)

Akeda, Koji; Nishimura, Akinobu; Satonaka, Haruhiko; Shintani, Ken; Kusuzaki, Katsuyuki; Matsumine, Akihiko; Kasai, Yuichi; Masuda, Koichi; Uchida, Atsumasa

2009-11-01

Osteosarcoma (OS) is the most common primary malignant tumor of the bone and often forms pulmonary metastases, which are the most important prognostic factor. For further elucidation of the mechanism underlying the progression and metastasis of human OS, a culture system mimicking the microenvironment of the tumor in vivo is needed. We report a novel three-dimensional (3D) alginate spheroid culture system of murine osteosarcoma. Two different metastatic clones, the parental Dunn and its derivative line LM8, which has a higher metastatic potential to the lungs, were encapsulated in alginate beads to develop the 3D culture system. The beads containing murine OS cells were also transplanted into mice to determine their metastatic potential in vivo. In this culture system, murine OS cells encapsulated in alginate beads were able to grow in a 3D structure with cells detaching from the alginate environment. The number of detaching cells was higher in the LM8 cell line than the Dunn cell line. In the in vivo alginate bead transplantation model, the rate of pulmonary metastasis was higher with LM8 cells compared with that of Dunn cells. The cell characteristics and kinetics in this culture system closely reflect the original malignant potential of the cells in vivo.

Mary Jane Hogue (1883-1962): A pioneer in human brain tissue culture.

Science.gov (United States)

Zottoli, Steven J; Seyfarth, Ernst-August

2018-05-16

The ability to maintain human brain explants in tissue culture was a critical step in the use of these cells for the study of central nervous system disorders. Ross G. Harrison (1870-1959) was the first to successfully maintain frog medullary tissue in culture in 1907, but it took another 38 years before successful culture of human brain tissue was accomplished. One of the pioneers in this achievement was Mary Jane Hogue (1883-1962). Hogue was born into a Quaker family in 1883 in West Chester, Pennsylvania, and received her undergraduate degree from Goucher College in Baltimore, Maryland. Research with the developmental biologist Theodor Boveri (1862-1915) in Würzburg, Germany, resulted in her Ph.D. (1909). Hogue transitioned from studying protozoa to the culture of human brain tissue in the 1940s and 1950s, when she was one of the first to culture cells from human fetal, infant, and adult brain explants. We review Hogue's pioneering contributions to the study of human brain cells in culture, her putative identification of progenitor neuroblast and/or glioblast cells, and her use of the cultures to study the cytopathogenic effects of poliovirus. We also put Hogue's work in perspective by discussing how other women pioneers in tissue culture influenced Hogue and her research.

The construction of a two-dimensional reproducing kernel function and its application in a biomedical model.

Science.gov (United States)

Guo, Qi; Shen, Shu-Ting

2016-04-29

There are two major classes of cardiac tissue models: the ionic model and the FitzHugh-Nagumo model. During computer simulation, each model entails solving a system of complex ordinary differential equations and a partial differential equation with non-flux boundary conditions. The reproducing kernel method possesses significant applications in solving partial differential equations. The derivative of the reproducing kernel function is a wavelet function, which has local properties and sensitivities to singularity. Therefore, study on the application of reproducing kernel would be advantageous. Applying new mathematical theory to the numerical solution of the ventricular muscle model so as to improve its precision in comparison with other methods at present. A two-dimensional reproducing kernel function inspace is constructed and applied in computing the solution of two-dimensional cardiac tissue model by means of the difference method through time and the reproducing kernel method through space. Compared with other methods, this method holds several advantages such as high accuracy in computing solutions, insensitivity to different time steps and a slow propagation speed of error. It is suitable for disorderly scattered node systems without meshing, and can arbitrarily change the location and density of the solution on different time layers. The reproducing kernel method has higher solution accuracy and stability in the solutions of the two-dimensional cardiac tissue model.

Leiomyoma Cells in 3-Dimensional Cultures Demonstrate an Attenuated Response to Fasudil, a Rho-Kinase Inhibitor, When Compared to 2-Dimensional Cultures

Science.gov (United States)

Malik, Minnie; Britten, Joy; Segars, James

2014-01-01

Uterine leiomyomata are common benign tumors in women of reproductive age and demonstrate an attenuated response to mechanical signaling that involves Rho and integrins. To further characterize the impairment in Rho signaling, we studied the effect of Rho-kinase inhibitor, fasudil, on extracellular matrix production, in 2-dimensional (2D) and 3-dimensional (3D) cultures of leiomyoma and myometrial cells. Leiomyoma 2D cultures demonstrated a rapid decrease in gene transcripts and protein for fibronectin, procollagen 1A, and versican. In 3D cultures, fibronectin and procollagen 1A proteins demonstrated increased levels at lower concentrations of fasudil, followed by a concentration-dependent decrease. Versican protein increased up to 3-fold, whereas fibromodulin demonstrated a significant decrease of 1.92-fold. Myometrial 2D or 3D cultures demonstrated a decrease in all proteins after 72 hours of treatment. The 3D leiomyoma cultures demonstrated a significant increase in active RhoA, followed by a concentration-dependent decrease at higher concentrations. A concentration-dependent increase in phospho-extracellular regulated signal kinase and proapoptotic protein Bax was observed in 3D leiomyoma cultures. Fasudil relaxed the contraction of the 3D collagen gels caused by myometrium and leiomyoma cell growth. These findings indicate that the altered state of Rho signaling in leiomyoma was more clearly observed in 3D cultures. The results also suggest that fasudil may have clinical applicability for treatment of uterine leiomyoma. PMID:25084783

Downregulation of Connective Tissue Growth Factor by Three-Dimensional Matrix Enhances Ovarian Carcinoma Cell Invasion

Science.gov (United States)

Barbolina, Maria V.; Adley, Brian P.; Kelly, David L.; Shepard, Jaclyn; Fought, Angela J.; Scholtens, Denise; Penzes, Peter; Shea, Lonnie D.; Sharon Stack, M

2010-01-01

Epithelial ovarian carcinoma (EOC) is a leading cause of death from gynecologic malignancy, due mainly to the prevalence of undetected metastatic disease. The process of cell invasion during intra-peritoneal anchoring of metastatic lesions requires concerted regulation of many processes, including modulation of adhesion to the extracellular matrix and localized invasion. Exploratory cDNA microarray analysis of early response genes (altered after 4 hours of 3-dimensional collagen culture) coupled with confirmatory real-time RT-PCR, multiple three-dimensional cell culture matrices, Western blot, immunostaining, adhesion, migration, and invasion assays were used to identify modulators of adhesion pertinent to EOC progression and metastasis. cDNA microarray analysis indicated a dramatic downregulation of connective tissue growth factor (CTGF) in EOC cells placed in invasion-mimicking conditions (3-dimensional type I collagen). Examination of human EOC specimens revealed that CTGF expression was absent in 46% of the tested samples (n=41), but was present in 100% of normal ovarian epithelium samples (n=7). Reduced CTGF expression occurs in many types of cells and may be a general phenomenon displayed by cells encountering a 3D environment. CTGF levels were inversely correlated with invasion such that downregulation of CTGF increased, while its upregulation reduced, collagen invasion. Cells adhered preferentially to a surface comprised of both collagen I and CTGF relative to either component alone using α6β1 and α3β1 integrins. Together these data suggest that downregulation of CTGF in EOC cells may be important for cell invasion through modulation of cell-matrix adhesion. PMID:19382180

Micro fluidic System for Culturing and Monitoring of Neuronal Cells and Tissue

DEFF Research Database (Denmark)

Bakmand, Tanya; Waagepetersen, Helle S.

The aim of this Ph.D. project was to combine experience within cell and tissue culturing, electrochemistry and microfabrication in order to develop an in vivo-like fluidic culturing platform, challenging the traditional culturing methods. The first goal was to develope a fluidic system for cultur...... with mass production. The last part of this thesis also includes perspectives on how to expand the latest designed device to facilitate culturing of tissue and co-culturing of cells....

A Review of Three-Dimensional Printing in Tissue Engineering.

Science.gov (United States)

Sears, Nick A; Seshadri, Dhruv R; Dhavalikar, Prachi S; Cosgriff-Hernandez, Elizabeth

2016-08-01

Recent advances in three-dimensional (3D) printing technologies have led to a rapid expansion of applications from the creation of anatomical training models for complex surgical procedures to the printing of tissue engineering constructs. In addition to achieving the macroscale geometry of organs and tissues, a print layer thickness as small as 20 μm allows for reproduction of the microarchitectures of bone and other tissues. Techniques with even higher precision are currently being investigated to enable reproduction of smaller tissue features such as hepatic lobules. Current research in tissue engineering focuses on the development of compatible methods (printers) and materials (bioinks) that are capable of producing biomimetic scaffolds. In this review, an overview of current 3D printing techniques used in tissue engineering is provided with an emphasis on the printing mechanism and the resultant scaffold characteristics. Current practical challenges and technical limitations are emphasized and future trends of bioprinting are discussed.

Silk-fibrin/hyaluronic acid composite gels for nucleus pulposus tissue regeneration.

Science.gov (United States)

Park, Sang-Hyug; Cho, Hongsik; Gil, Eun Seok; Mandal, Biman B; Min, Byoung-Hyun; Kaplan, David L

2011-12-01

Scaffold designs are critical for in vitro culture of tissue-engineered cartilage in three-dimensional environments to enhance cellular differentiation for tissue engineering and regenerative medicine. In the present study we demonstrated silk and fibrin/hyaluronic acid (HA) composite gels as scaffolds for nucleus pulposus (NP) cartilage formation, providing both biochemical support for NP outcomes as well as fostering the retention of size of the scaffold during culture due to the combined features of the two proteins. Passage two (P2) human chondrocytes cultured in 10% serum were encapsulated within silk-fibrin/HA gels. Five study groups with fibrin/HA gel culture (F/H) along with varying silk concentrations (2% silk gel only, fibrin/HA gel culture with 1% silk [F/H+1S], 1.5% silk [F/H+1.5S], and 2% silk [F/H+2S]) were cultured in serum-free chondrogenic defined media (CDM) for 4 weeks. Histological examination with alcian blue showed a defined chondrogenic area at 1 week in all groups that widened homogenously until 4 weeks. In particular, chondrogenic differentiation observed in the F/H+1.5S had no reduction in size throughout the culture period. The results of biochemical and molecular biological evaluations supported observations made during histological examination. Mechanical strength measurements showed that the silk mixed gels provided stronger mechanical properties for NP tissue than fibrin/HA composite gels in CDM. This effect could potentially be useful in the study of in vitro NP tissue engineering as well as for clinical implications for NP tissue regeneration.

On the two-dimensional Saigo-Maeda fractional calculus asociated with two-dimensional Aleph TRANSFORM

Directory of Open Access Journals (Sweden)

Dinesh Kumar

2013-11-01

Full Text Available This paper deals with the study of two-dimensional Saigo-Maeda operators of Weyl type associated with Aleph function defined in this paper. Two theorems on these defined operators are established. Some interesting results associated with the H-functions and generalized Mittag-Leffler functions are deduced from the derived results. One dimensional analog of the derived results is also obtained.

Ex vivo culture of patient tissue & examination of gene delivery.

LENUS (Irish Health Repository)

Rajendran, Simon

2012-01-31

This video describes the use of patient tissue as an ex vivo model for the study of gene delivery. Fresh patient tissue obtained at the time of surgery is sliced and maintained in culture. The ex vivo model system allows for the physical delivery of genes into intact patient tissue and gene expression is analysed by bioluminescence imaging using the IVIS detection system. The bioluminescent detection system demonstrates rapid and accurate quantification of gene expression within individual slices without the need for tissue sacrifice. This slice tissue culture system may be used in a variety of tissue types including normal and malignant tissue and allows us to study the effects of the heterogeneous nature of intact tissue and the high degree of variability between individual patients. This model system could be used in certain situations as an alternative to animal models and as a complementary preclinical mode prior to entering clinical trial.

Yield improvement strategies for the production of secondary metabolites in plant tissue culture: silymarin from Silybum marianum tissue culture.

Science.gov (United States)

AbouZid, S

2014-01-01

Plant cell culture can be a potential source for the production of important secondary metabolites. This technology bears many advantages over conventional agricultural methods. The main problem to arrive at a cost-effective process is the low productivity. This is mainly due to lack of differentiation in the cultured cells. Many approaches have been used to maximise the yield of secondary metabolites produced by cultured plant cells. Among these approaches: choosing a plant with a high biosynthetic capacity, obtaining efficient cell line for growth and production of metabolite of interest, manipulating culture conditions, elicitation, metabolic engineering and organ culture. This article gives an overview of the various approaches used to maximise the production of pharmaceutically important secondary metabolites in plant cell cultures. Examples of using these different approaches are shown for the production of silymarin from Silybum marianum tissue culture.

Migration assay on primary culture isolated from patient's primary breast cancer tissue

Directory of Open Access Journals (Sweden)

ED Yuliana

2014-12-01

Full Text Available Background: Migration is an essential component of breast cancer metastasis, which studyhas been concentrated on culture of established breast cancer cell lines that do not accuratelyrepresent the sophistication and heterogeneity of patient's breast cancer. An attempt toperform migration assay using Boyden Chamber Assay (BCA on primary culture originatingfrom patient's breast cancer tissue was developed to accommodate upcoming study of breastcancer migration in lndonesian patients.Methods: Pathologically proven primary breast cancer tissue samples were obtained fromCiptomangunkusumo Hospital during core (n=4 and incisional (n=3 biopsies of stage llAup to stage lllA breast cancer patients. Following biopsy, the breast cancer tissue samplesunderwent processings to isolate the cancer cells. These cancer cells were -then resuspendedwithin Dulbecco's modified Eagle's medium (DMEM ahd cultured in 12-well plate. The growthof primary culture were observed and compared between the core biopsy and the incisionalbiopsy specimens. Optimization of BCA method was later performed to investigate themigration of the breast cancer primary culture towards different experirnental conditions, whichwere control, Fetal Bovine Serum (FBS, and Stromal Derived Factor-l (SDF-1. Two differentnumber of breast cancer cells were tested for the optimization of the BCA, which were 1 x 105and3x105cells.Results: None of the culture performed on core biopsy specimens grew, while one out ofthree incisional biopsy specimens grew until confluence. The one primary culture that grewwas later assesed using BCA to assess its migration index towards different experimentalconditions. Using 1 x 10s breast cancer cells in the BCA , the result of the absorbance level ofmigrated cells showed that the migration towards SDF-1 (0.529 nearly doubled the migrationtowards controlmedium (0.239 and FBS (0.209. Meanwhile, the absorbance levelwas simiiarbetween the control medium (1.050, FBS (1 .103

Alginate foam-based three-dimensional culture to investigate drug sensitivity in primary leukaemia cells.

Science.gov (United States)

Karimpoor, Mahroo; Yebra-Fernandez, Eva; Parhizkar, Maryam; Orlu, Mine; Craig, Duncan; Khorashad, Jamshid S; Edirisinghe, Mohan

2018-04-01

The development of assays for evaluating the sensitivity of leukaemia cells to anti-cancer agents is becoming an important aspect of personalized medicine. Conventional cell cultures lack the three-dimensional (3D) structure of the bone marrow (BM), the extracellular matrix and stromal components which are crucial for the growth and survival of leukaemia stem cells. To accurately predict the sensitivity of the leukaemia cells in an in vitro assay a culturing system containing the essential components of BM is required. In this study, we developed a porous calcium alginate foam-based scaffold to be used for 3D culture. The new 3D culture was shown to be cell compatible as it supported the proliferation of both normal haematopoietic and leukaemia cells. Our cell differential assay for myeloid markers showed that the porous foam-based 3D culture enhanced myeloid differentiation in both leukaemia and normal haematopoietic cells compared to two-dimensional culture. The foam-based scaffold reduced the sensitivity of the leukaemia cells to the tested antileukaemia agents in K562 and HL60 leukaemia cell line model and also primary myeloid leukaemia cells. This observation supports the application of calcium alginate foams as scaffold components of the 3D cultures for investigation of sensitivity to antileukaemia agents in primary myeloid cells. © 2018 The Author(s).

Tissue culture of ornamental cacti

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Eugenio Pérez-Molphe-Balch

2015-12-01

Full Text Available Cacti species are plants that are well adapted to growing in arid and semiarid regions where the main problem is water availability. Cacti have developed a series of adaptations to cope with water scarcity, such as reduced leaf surface via morphological modifications including spines, cereous cuticles, extended root systems and stem tissue modifications to increase water storage, and crassulacean acid metabolism to reduce transpiration and water loss. Furthermore, seeds of these plants very often exhibit dormancy, a phenomenon that helps to prevent germination when the availability of water is reduced. In general, cactus species exhibit a low growth rate that makes their rapid propagation difficult. Cacti are much appreciated as ornamental plants due to their great variety and diversity of forms and their beautiful short-life flowers; however, due to difficulties in propagating them rapidly to meet market demand, they are very often over-collected in their natural habitats, which leads to numerous species being threatened, endangered or becoming extinct. Therefore, plant tissue culture techniques may facilitate their propagation over a shorter time period than conventional techniques used for commercial purposes; or may help to recover populations of endangered or threatened species for their re-introduction in the wild; or may also be of value to the preservation and conservation of the genetic resources of this important family. Herein we present the state-of-the-art of tissue culture techniques used for ornamental cacti and selected suggestions for solving a number of the problems faced by members of the Cactaceae family.

Two-dimensional nuclear magnetic resonance spectroscopy

International Nuclear Information System (INIS)

Bax, A.; Lerner, L.

1986-01-01

Great spectral simplification can be obtained by spreading the conventional one-dimensional nuclear magnetic resonance (NMR) spectrum in two independent frequency dimensions. This so-called two-dimensional NMR spectroscopy removes spectral overlap, facilitates spectral assignment, and provides a wealth of additional information. For example, conformational information related to interproton distances is available from resonance intensities in certain types of two-dimensional experiments. Another method generates 1 H NMR spectra of a preselected fragment of the molecule, suppressing resonances from other regions and greatly simplifying spectral appearance. Two-dimensional NMR spectroscopy can also be applied to the study of 13 C and 15 N, not only providing valuable connectivity information but also improving sensitivity of 13 C and 15 N detection by up to two orders of magnitude. 45 references, 10 figures

Three-dimensional reciprocal space x-ray coherent scattering tomography of two-dimensional object.

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Zhu, Zheyuan; Pang, Shuo

2018-04-01

X-ray coherent scattering tomography is a powerful tool in discriminating biological tissues and bio-compatible materials. Conventional x-ray scattering tomography framework can only resolve isotropic scattering profile under the assumption that the material is amorphous or in powder form, which is not true especially for biological samples with orientation-dependent structure. Previous tomography schemes based on x-ray coherent scattering failed to preserve the scattering pattern from samples with preferred orientations, or required elaborated data acquisition scheme, which could limit its application in practical settings. Here, we demonstrate a simple imaging modality to preserve the anisotropic scattering signal in three-dimensional reciprocal (momentum transfer) space of a two-dimensional sample layer. By incorporating detector movement along the direction of x-ray beam, combined with a tomographic data acquisition scheme, we match the five dimensions of the measurements with the five dimensions (three in momentum transfer domain, and two in spatial domain) of the object. We employed a collimated pencil beam of a table-top copper-anode x-ray tube, along with a panel detector to investigate the feasibility of our method. We have demonstrated x-ray coherent scattering tomographic imaging at a spatial resolution ~2 mm and momentum transfer resolution 0.01 Å -1 for the rotation-invariant scattering direction. For any arbitrary, non-rotation-invariant direction, the same spatial and momentum transfer resolution can be achieved based on the spatial information from the rotation-invariant direction. The reconstructed scattering profile of each pixel from the experiment is consistent with the x-ray diffraction profile of each material. The three-dimensional scattering pattern recovered from the measurement reveals the partially ordered molecular structure of Teflon wrap in our sample. We extend the applicability of conventional x-ray coherent scattering tomography to

21 CFR 864.2240 - Cell and tissue culture supplies and equipment.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cell and tissue culture supplies and equipment. 864.2240 Section 864.2240 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Cell And Tissue Culture Products...

Three-Dimensional Computer-Assisted Two-Layer Elastic Models of the Face.

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Ueda, Koichi; Shigemura, Yuka; Otsuki, Yuki; Fuse, Asuka; Mitsuno, Daisuke

2017-11-01

To make three-dimensional computer-assisted elastic models for the face, we decided on five requirements: (1) an elastic texture like skin and subcutaneous tissue; (2) the ability to take pen marking for incisions; (3) the ability to be cut with a surgical knife; (4) the ability to keep stitches in place for a long time; and (5) a layered structure. After testing many elastic solvents, we have made realistic three-dimensional computer-assisted two-layer elastic models of the face and cleft lip from the computed tomographic and magnetic resonance imaging stereolithographic data. The surface layer is made of polyurethane and the inner layer is silicone. Using this elastic model, we taught residents and young doctors how to make several typical local flaps and to perform cheiloplasty. They could experience realistic simulated surgery and understand three-dimensional movement of the flaps.

Soft-tissue segmentation and three-dimensional display with MR imaging

International Nuclear Information System (INIS)

Koenig, H.A.; Laub, G.

1987-01-01

The purpose of this study is to design a method capable of segmenting different soft-tissue types. The investigated cases were measured using fast three-dimensional (3D) sequences (FISP of fast low-angle shot) with isotropic voxel resolution of nearly 1 mm. The segmentation is based on the assumption that different tissue types are discernible by their morphologic and/or physical features. Surface reconstructions are then used to display specific tissue types from different viewing directions. This automatic procedure is applied to different head cases to represent specific tissues in 3D format. With 3D techniques, rotation of classified objects in cine format is performed for better topologic correlation and therapeutic planning

Promotion of Vascular Morphogenesis of Endothelial Cells Co-Cultured with Human Adipose-Derived Mesenchymal Stem Cells Using Polycaprolactone/Gelatin Nanofibrous Scaffolds

Directory of Open Access Journals (Sweden)

Yun-Min Kook

2018-02-01

Full Text Available New blood vessel formation is essential for tissue regeneration to deliver oxygen and nutrients and to maintain tissue metabolism. In the field of tissue engineering, in vitro fabrication of new artificial vessels has been a longstanding challenge. Here we developed a technique to reconstruct a microvascular system using a polycaprolactone (PCL/gelatin nanofibrous structure and a co-culture system. Using a simple electrospinning process, we fabricated three-dimensional mesh scaffolds to support the sprouting of human umbilical vein endothelial cells (HUVECs along the electrospun nanofiber. The co-culture with adipose-derived mesenchymal stem cells (ADSCs supported greater sprouting of endothelial cells (ECs. In a two-dimensional culture system, angiogenic cell assembly produced more effective direct intercellular interactions and paracrine signaling from ADSCs to assist in the vascular formation of ECs, compared to the influence of growth factor. Although vascular endothelial growth factor and sphingosine-1-phosphate were present during the culture period, the presence of ADSCs was the most important factor for the construction of a cell-assembled structure in the two-dimensional culture system. On the contrary, HUVECs co-cultured on PCL/gelatin nanofiber scaffolds produced mature and functional microvessel and luminal structures with a greater expression of vascular markers, including platelet endothelial cell adhesion molecule-1 and podocalyxin. Furthermore, both angiogenic factors and cellular interactions with ADSCs through direct contact and paracrine molecules contributed to the formation of enhanced engineered blood vessel structures. It is expected that the co-culture system of HUVECs and ADSCs on bioengineered PCL/gelatin nanofibrous scaffolds will promote robust and functional microvessel structures and will be valuable for the regeneration of tissue with restored blood vessels.

On some classes of two-dimensional local models in discrete two-dimensional monatomic FPU lattice with cubic and quartic potential

International Nuclear Information System (INIS)

Quan, Xu; Qiang, Tian

2009-01-01

This paper discusses the two-dimensional discrete monatomic Fermi–Pasta–Ulam lattice, by using the method of multiple-scale and the quasi-discreteness approach. By taking into account the interaction between the atoms in the lattice and their nearest neighbours, it obtains some classes of two-dimensional local models as follows: two-dimensional bright and dark discrete soliton trains, two-dimensional bright and dark line discrete breathers, and two-dimensional bright and dark discrete breather. (condensed matter: structure, thermal and mechanical properties)

Three-dimensional co-culture facilitates the differentiation of embryonic stem cells into mature cardiomyocytes.

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Ou, Dong-Bo; He, Yong; Chen, Rui; Teng, Ji-Wei; Wang, Hong-Tao; Zeng, Di; Liu, Xiong-Tao; Ding, Lu; Huang, Jin-Yan; Zheng, Qiang-Sun

2011-12-01

The cardiomyocyte (CM) differentiation of embryonic stem cells (ESCs) is routinely cultured as two-dimensional (2D) monolayer, which doesn't mimic in vivo physiological environment and may lead to low differentiated level of ESCs. Here, we develop a novel strategy that enhances CM differentiation of ESCs in collagen matrix three-dimensional (3D) culture combined with indirect cardiac fibroblasts co-culture. ESCs were cultured in hanging drops to form embryoid bodies (EBs) and then applied on collagen matrix. The EBs were indirectly co-cultured with cardiac fibroblasts by the hanging cell culture inserts (PET 1 µm). The molecular expressions and ultrastructural characteristics of ESC-derived CMs (ESCMs) were analyzed by real time RT-PCR, immunocytochemistry, and Transmission Electron Microscopy (TEM). We found that the percentage of beating EBs with cardiac fibroblasts co-culture was significantly higher than that without co-culture after differentiation period of 8 days. Type I collagen used as 3D substrates enhanced the late-stage CM differentiation of ESCs and had effect on ultrastructural mature of ESCMs in late-stage development. The combined effects of 3D and co-culture that mimic in vivo physiological environment further improved the efficiency of CM differentiation from ESCs, resulting in fiber-like structures of cardiac cells with organized sarcomeric structure in ESCMs. This novel 3D co-culture system emphasizes the fact that the ESC differentiation is actively responding to cues from their environment and those cues can drive phenotypic control, which provides a useful in vitro model to investigate CM differentiation of stem cells. Copyright © 2011 Wiley Periodicals, Inc.

Two-dimensional models

International Nuclear Information System (INIS)

Schroer, Bert; Freie Universitaet, Berlin

2005-02-01

It is not possible to compactly review the overwhelming literature on two-dimensional models in a meaningful way without a specific viewpoint; I have therefore tacitly added to the above title the words 'as theoretical laboratories for general quantum field theory'. I dedicate this contribution to the memory of J. A. Swieca with whom I have shared the passion of exploring 2-dimensional models for almost one decade. A shortened version of this article is intended as a contribution to the project 'Encyclopedia of mathematical physics' and comments, suggestions and critical remarks are welcome. (author)

Application of Tissue Culture and Transformation Techniques in Model Species Brachypodium distachyon.

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Sogutmaz Ozdemir, Bahar; Budak, Hikmet

2018-01-01

Brachypodium distachyon has recently emerged as a model plant species for the grass family (Poaceae) that includes major cereal crops and forage grasses. One of the important traits of a model species is its capacity to be transformed and ease of growing both in tissue culture and in greenhouse conditions. Hence, plant transformation technology is crucial for improvements in agricultural studies, both for the study of new genes and in the production of new transgenic plant species. In this chapter, we review an efficient tissue culture and two different transformation systems for Brachypodium using most commonly preferred gene transfer techniques in plant species, microprojectile bombardment method (biolistics) and Agrobacterium-mediated transformation.In plant transformation studies, frequently used explant materials are immature embryos due to their higher transformation efficiencies and regeneration capacity. However, mature embryos are available throughout the year in contrast to immature embryos. We explain a tissue culture protocol for Brachypodium using mature embryos with the selected inbred lines from our collection. Embryogenic calluses obtained from mature embryos are used to transform Brachypodium with both plant transformation techniques that are revised according to previously studied protocols applied in the grasses, such as applying vacuum infiltration, different wounding effects, modification in inoculation and cocultivation steps or optimization of bombardment parameters.

Three-dimensional vs. two-dimensional shear-wave elastography of the testes - preliminary study on a healthy collective.

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Marcon, J; Trottmann, M; Rübenthaler, J; D'Anastasi, M; Stief, C G; Reiser, M F; Clevert, D A

2016-01-01

Shear wave elastography (SWE) and its derivative Supersonic Shear Imaging (SSI) are newer techniques for the determination of tissue elasticity by measuring the velocity of generated shear waves (SWV), which correlates positively with tissue stiffness.The techniques are integrated into many modern ultrasound systems and have been examined in the evaluation of viscoelastic properties of different organ systems. Two-dimensional shear wave elastography (2D SWE) of the testes has been found to be a useful tool in recent studies which included the determination of standard values in healthy volunteers. Three-dimensional shear wave elastography (3D SWE) is the latest development in elastography and is made possible by generation of a multiplanar three-dimensional map via volumetric acquisition with a special ultrasound transducer. This technique allows the assessment of tissue elasticity in a three-dimensional, fully accessible organ map.The aim of this preliminary study was to both evaluate the feasibility of 3D SWE and to compare 2D and 3D SWE standard values in the testes of healthy subjects. We examined the testes of healthy male volunteers (n = 32) with a mean age of 51.06±17.75 years (range 25-77 years) by B-mode ultrasound, 2D and 3D SWE techniques in September of 2016. Volunteers with a history of testicular pathologies were excluded. For all imaging procedures the SL15-4 linear transducer (bandwidth 4-15 MHz) as well as the SLV16-4 volumetric probe (bandwidth 4-16 MHz) of the Aixplorer® ultrasound device (SuperSonic Imagine, Aix-en-Provence, France) were used. Seven regions of interest (ROI, Q-Box®) within the testes were evaluated for SWV using both procedures. SWV values were described in m/s. Results were statistically evaluated using univariateanalysis. Mean SWV values were 1.05 m/s for the 2D SWE and 1.12 m/s for the 3D SWE.Comparisons of local areas delivered no statistically significant differences (p = 0.11 to p = 0.66), except for

Citrus tissue culture employing vegetative explants.

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Chaturvedi, H C; Singh, S K; Sharma, A K; Agnihotri, S

2001-11-01

Citrus being a number one fruit of the world due to its high nutritional value, huge production of fruits and fruit products, the citrus industry may be considered a major fruit industry. Though citrus orchard area in India is comparable to USA, the produce is far less, while its export is nil. Biotechnology has played an outstanding role in boosting the citrus industry, e.g., in Spain, which is now the biggest exporter of citrus fruit with the application of micrografting. Amongst the fruit trees, perhaps the maximum tissue culture research has been done in citrus during the past four decades, however, the results of practical value are meagre. The shortfalls in citrus tissue culture research and some advancements made in this direction along with bright prospects are highlighted, restricting the review to vegetative explants only. Whilst utilization of nucellar embryogenesis is limited to rootstocks, the other aspects, like, regeneration and proliferation of shoot meristems measuring 200 microm in length--a global breakthrough--of two commercially important scion species, Citrus aurantifolia and C. sinensis and an important rootstock, C. limonia, improvement of micrografting technique, cloning of the same two scion species as well as some Indian rootstock species, employing nodal stem segments of mature trees, of immense practical value have been elaborated. A rare phenomenon of shift in the morphogenetic pattern of differentiation from shoot bud differentiation to embryoid formation occurred during the long-term culture of stem callus of C. grandis. Stem callus-regenerated plants of C. aurantifolia, C. sinensis and C. grandis showed variation in their ploidy levels and a somaclonal variant of C. sinensis, which produced seedless fruits was isolated. Tailoring of rooting in microshoots to a tap root-like system by changing the inorganic salt composition of the rooting medium, resulting in 100% transplant success, and germplasm preservation through normal growth

Two-dimensional multifractal cross-correlation analysis

International Nuclear Information System (INIS)

Xi, Caiping; Zhang, Shuning; Xiong, Gang; Zhao, Huichang; Yang, Yonghong

2017-01-01

Highlights: • We study the mathematical models of 2D-MFXPF, 2D-MFXDFA and 2D-MFXDMA. • Present the definition of the two-dimensional N 2 -partitioned multiplicative cascading process. • Do the comparative analysis of 2D-MC by 2D-MFXPF, 2D-MFXDFA and 2D-MFXDMA. • Provide a reference on the choice and parameter settings of these methods in practice. - Abstract: There are a number of situations in which several signals are simultaneously recorded in complex systems, which exhibit long-term power-law cross-correlations. This paper presents two-dimensional multifractal cross-correlation analysis based on the partition function (2D-MFXPF), two-dimensional multifractal cross-correlation analysis based on the detrended fluctuation analysis (2D-MFXDFA) and two-dimensional multifractal cross-correlation analysis based on the detrended moving average analysis (2D-MFXDMA). We apply these methods to pairs of two-dimensional multiplicative cascades (2D-MC) to do a comparative study. Then, we apply the two-dimensional multifractal cross-correlation analysis based on the detrended fluctuation analysis (2D-MFXDFA) to real images and unveil intriguing multifractality in the cross correlations of the material structures. At last, we give the main conclusions and provide a valuable reference on how to choose the multifractal algorithms in the potential applications in the field of SAR image classification and detection.

Three-dimensional micro-scale strain mapping in living biological soft tissues.

Science.gov (United States)

Moo, Eng Kuan; Sibole, Scott C; Han, Sang Kuy; Herzog, Walter

2018-04-01

Non-invasive characterization of the mechanical micro-environment surrounding cells in biological tissues at multiple length scales is important for the understanding of the role of mechanics in regulating the biosynthesis and phenotype of cells. However, there is a lack of imaging methods that allow for characterization of the cell micro-environment in three-dimensional (3D) space. The aims of this study were (i) to develop a multi-photon laser microscopy protocol capable of imprinting 3D grid lines onto living tissue at a high spatial resolution, and (ii) to develop image processing software capable of analyzing the resulting microscopic images and performing high resolution 3D strain analyses. Using articular cartilage as the biological tissue of interest, we present a novel two-photon excitation imaging technique for measuring the internal 3D kinematics in intact cartilage at sub-micrometer resolution, spanning length scales from the tissue to the cell level. Using custom image processing software, we provide accurate and robust 3D micro-strain analysis that allows for detailed qualitative and quantitative assessment of the 3D tissue kinematics. This novel technique preserves tissue structural integrity post-scanning, therefore allowing for multiple strain measurements at different time points in the same specimen. The proposed technique is versatile and opens doors for experimental and theoretical investigations on the relationship between tissue deformation and cell biosynthesis. Studies of this nature may enhance our understanding of the mechanisms underlying cell mechano-transduction, and thus, adaptation and degeneration of soft connective tissues. We presented a novel two-photon excitation imaging technique for measuring the internal 3D kinematics in intact cartilage at sub-micrometer resolution, spanning from tissue length scale to cellular length scale. Using a custom image processing software (lsmgridtrack), we provide accurate and robust micro

Potato transformation and potato cyst nematode infection on potato plantlets in tissue culture

Science.gov (United States)

These two protocols describe the methods for generating transgenic potato plants and for evaluating potato cyst nematode (Globodera rostochiensis and G. pallida) infection on potato plantlets in tissue culture. These methods are useful tools that can be used in the study of the interactions between ...

Two-dimensional beam profiles and one-dimensional projections

Science.gov (United States)

Findlay, D. J. S.; Jones, B.; Adams, D. J.

2018-05-01

One-dimensional projections of improved two-dimensional representations of transverse profiles of particle beams are proposed for fitting to data from harp-type monitors measuring beam profiles on particle accelerators. Composite distributions, with tails smoothly matched on to a central (inverted) parabola, are shown to give noticeably better fits than single gaussian and single parabolic distributions to data from harp-type beam profile monitors all along the proton beam transport lines to the two target stations on the ISIS Spallation Neutron Source. Some implications for inferring beam current densities on the beam axis are noted.

Tobacco clones derived from tissue culture with supersensitivity to ozone

International Nuclear Information System (INIS)

Sun, E.J.; Kang, H.W.

2003-01-01

New tobacco clones supersensitive to ozone were obtained from tissue culture. - At least two supersensitive tobacco somaclones were obtained from tissue culture (TC) , when this approach was used to asexually propagate Bel-W3 tobacco indicator plants. These somaclones can detect as low as 30 ppb ozone for a 4-h exposure duration both within CSTR exposure chambers and in ambient air. Comparison of the injury index and their coefficient of variance showed that the TC plantlets usually have more uniform performance in response to ozone in addition to their higher sensitivity. A quick regeneration procedure was established to preserve the supersensitive germplasm immediately when it was found. The TC plantlets will flower and produce seed similar to seed-grown tobacco. The TC approach proved to be a better propagation system for valuable indicator plant species. The mechanism that causes the variation and the possible difference in their genome from seed-grown tobacco is still unknown. Further studies are needed in the future to determine if factors in the TC system may be responsible for the sensitivity difference

Entrapment of cultured pancreas islets in three-dimensional collagen matrices.

Science.gov (United States)

Chao, S H; Peshwa, M V; Sutherland, D E; Hu, W S

1992-01-01

In vitro culture of islets of Langerhans decreases their immunogenicity, presumably by eliminating passenger leukocytes and other Ia+ presenting cells within the islets. Islets cultivated in petri dishes either at 37 degrees C or at 25 degrees C gradually disintegrate during culture in a time-dependent manner which is related to the free-floating condition of the islets. Also, a fraction of the islets disperse as single cells and beta-cell aggregates or adhere to the bottom of the culture dishes. Thus, the retrieval rate of transplantable islets is dampened due to their disintegration and spontaneous dispersion in conventional petri dish cultures. Entrapment of freshly harvested islets of Langerhans in a three-dimensional collagen matrix was studied as an alternative method for islet cultivation. The contraction of collagen fibrils during in vitro culture counteracts the dispersion of islets and helps in maintaining their integrity while in culture. It was observed that the entrapped islets maintain satisfactory morphology, viability, and capability of glucose-dependent insulin secretion for over 2 wk. The oxygen consumption rate and glucose metabolism of these islets was not deranged when entrapped in collagen. Also, the retrieval of islets is easier and more efficient than that observed in conventional culture systems. Our results indicate that culture of islets in three-dimensional collagen gels can potentially develop into an ideal system applicable to clinical transplantation of cultured islets or beta-cell aggregates.

Propagation of Aquilaria malaccensis seedlings through tissue culture techniques

International Nuclear Information System (INIS)

Salahbiah Abdul Majid; Zaiton Ahmad; Mohd Rafaie Abdul Salam; Nurhayati Irwan; Affrida Abu Hassan; Rusli Ibrahim

2010-01-01

Aquilaria malaccensis or karas is the principal source of gaharu resin, which is used in many cultures for incense, perfumes and traditional medicines. The species is mainly propagated conventionally through seeds, cuttings and graftings. Propagation by seeds is usually a reliable method for other forest species, but for karas, this technique is inadequate to meet the current demand of seedling supplies. This is principally due to its low seed viability, low germination rate, delayed rooting of seedlings, long life-cycle and rare seed production. Tissue culture has several advantages over conventional propagation, especially for obtaining large number of uniform and high-yielding plantlets or clones. This paper presents the current progress on mass-propagation of Aquilaria malaccensis seedlings through tissue culture technique at Nuclear Malaysia. (author)

Two-dimensional polyacrylamide gel electrophoresis of intracellular proteins

International Nuclear Information System (INIS)

Ojima, N.; Sakamoto, T.; Yamashita, M.

1996-01-01

Since two-dimensional electrophoresis was established by O'Farrell for analysis of intracellular proteins of Escherichia coli, it has been applied to separation of proteins of animal cells and tissues, and especially to identification of stress proteins. Using this technique, proteins are separated by isoelectric focusing containing 8 m urea in the first dimension and by SDS-PAGE in the second dimension. The gels are stained with Coomassie Blue R-250 dye, followed by silver staining. In the case of radio-labeled proteins, the gels are dried and then autoradiographed. In order to identify a specific protein separated by two-dimensional electrophoresis, a technique determining the N-terminal amino acid sequence of the protein has been developed recently. After the proteins in the gel were electrotransferred to a polyvinylidene difluoride membrane, the membrane was stained for protein with Commassie Blue and a stained membrane fragment was applied to a protein sequencer. Our recent studies demonstrated that fish cells newly synthesized various proteins in response to heat shock, cold nd osmotic stresses. For example, when cellular proteins extracted from cold-treated rainbow trout cells were subjected to two-dimensional gel electrophoresis, the 70 kDa protein was found to be synthesized during the cold-treatment. N-Terminal sequence analysis showed that the cold-inducible protein was a homolog of mammalian valosin-containing protein and yeast cell division cycle gene product CDC48p. Furthermore, the sequence data were useful for preparing PCR primers and a rabbit antibody against a synthetic peptide to analyze a role for the protein in the function of trout cells and mechanisms for regulation

Culture-Independent Identification of Mycobacterium avium Subspecies paratuberculosis in Ovine Tissues: Comparison with Bacterial Culture and Histopathological Lesions

Directory of Open Access Journals (Sweden)

Kamal R. Acharya

2017-12-01

Full Text Available Johne’s disease is a chronic debilitating enteropathy of ruminants caused by Mycobacterium avium subspecies paratuberculosis (MAP. Current abattoir surveillance programs detect disease via examination of gross lesions and confirmation by histopathological and/or tissue culture, which is time-consuming and has relatively low sensitivity. This study aimed to investigate whether a high-throughput quantitative PCR (qPCR test is a viable alternative for tissue testing. Intestine and mesenteric lymph nodes were sourced from sheep experimentally infected with MAP and the DNA extracted using a protocol developed for tissues, comprised enzymatic digestion of the tissue homogenate, chemical and mechanical lysis, and magnetic bead-based DNA purification. The extracted DNA was tested by adapting a previously validated qPCR for fecal samples, and the results were compared with culture and histopathology results of the corresponding tissues. The MAP tissue qPCR confirmed infection in the majority of sheep with gross lesions on postmortem (37/38. Likewise, almost all tissue culture (61/64 or histopathology (52/58 positives were detected with good to moderate agreement (Cohen’s kappa statistic and no significant difference to the reference tests (McNemar’s Chi-square test. Higher MAP DNA quantities corresponded to animals with more severe histopathology (odds ratio: 1.82; 95% confidence interval: 1.60, 2.07. Culture-independent strain typing on tissue DNA was successfully performed. This MAP tissue qPCR method had a sensitivity equivalent to the reference tests and is thus a viable replacement for gross- and histopathological examination of tissue samples in abattoirs. In addition, the test could be validated for testing tissue samples intended for human consumption.

FPGA Implementation of one-dimensional and two-dimensional cellular automata

International Nuclear Information System (INIS)

D'Antone, I.

1999-01-01

This report describes the hardware implementation of one-dimensional and two-dimensional cellular automata (CAs). After a general introduction to the cellular automata, we consider a one-dimensional CA used to implement pseudo-random techniques in built-in self test for VLSI. Due to the increase in digital ASIC complexity, testing is becoming one of the major costs in the VLSI production. The high electronics complexity, used in particle physics experiments, demands higher reliability than in the past time. General criterions are given to evaluate the feasibility of the circuit used for testing and some quantitative parameters are underlined to optimize the architecture of the cellular automaton. Furthermore, we propose a two-dimensional CA that performs a peak finding algorithm in a matrix of cells mapping a sub-region of a calorimeter. As in a two-dimensional filtering process, the peaks of the energy clusters are found in one evolution step. This CA belongs to Wolfram class II cellular automata. Some quantitative parameters are given to optimize the architecture of the cellular automaton implemented in a commercial field programmable gate array (FPGA)

Three-dimensional simulated microgravity culture improves the proliferation and odontogenic differentiation of dental pulp stem cell in PLGA scaffolds implanted in mice.

Science.gov (United States)

Li, Yanping; He, Lina; Pan, Shuang; Zhang, Lin; Zhang, Weiwei; Yi, Hong; Niu, Yumei

2017-02-01

Tooth regeneration through stem cell-based therapy is a promising treatment for tooth decay and loss. Human dental pulp stem cells (hDPSCs) have been widely identified as the stem cells with the most potential for tooth tissue regeneration. However, the culture of hDPSCs in vitro for tissue engineering is challenging, as cells may proliferate slowly or/and differentiate poorly in vivo. Dynamic three‑dimensional (3D) simulated microgravity (SMG) created using the rotary cell culture system is considered to an effective tool, which contributes to several cell functions. Thus, the present study aimed to investigate the effect of dynamic 3D SMG culture on the proliferation and odontogenic differentiation abilities of hDPSCs in poly (lactic‑co‑glycolic acid) (PLGA) scaffolds in nude mice. The hDPSCs on PLGA scaffolds were maintained separately in the 3D SMG culture system and static 3D cultures with osteogenic medium for 7 days in vitro. Subsequently, the cell‑PLGA complexes were implanted subcutaneously on the backs of nude mice for 4 weeks. The results of histological and immunohistochemical examinations of Ki‑67, type I collagen, dentin sialoprotein and DMP‑1 indicated that the proliferation and odontogenic differentiation abilities of the hDPSCs prepared in the 3D SMG culture system were higher, compared with those prepared in the static culture system. These findings suggested that dynamic 3D SMG culture likely contributes to tissue engineering by improving the proliferation and odontogenic differentiation abilities of hDPSCs in vivo.

Lie algebra contractions on two-dimensional hyperboloid

International Nuclear Information System (INIS)

Pogosyan, G. S.; Yakhno, A.

2010-01-01

The Inoenue-Wigner contraction from the SO(2, 1) group to the Euclidean E(2) and E(1, 1) group is used to relate the separation of variables in Laplace-Beltrami (Helmholtz) equations for the four corresponding two-dimensional homogeneous spaces: two-dimensional hyperboloids and two-dimensional Euclidean and pseudo-Euclidean spaces. We show how the nine systems of coordinates on the two-dimensional hyperboloids contracted to the four systems of coordinates on E 2 and eight on E 1,1 . The text was submitted by the authors in English.

Quasi-two-dimensional holography

International Nuclear Information System (INIS)

Kutzner, J.; Erhard, A.; Wuestenberg, H.; Zimpfer, J.

1980-01-01

The acoustical holography with numerical reconstruction by area scanning is memory- and time-intensive. With the experiences by the linear holography we tried to derive a scanning for the evaluating of the two-dimensional flaw-sizes. In most practical cases it is sufficient to determine the exact depth extension of a flaw, whereas the accuracy of the length extension is less critical. For this reason the applicability of the so-called quasi-two-dimensional holography is appropriate. The used sound field given by special probes is divergent in the inclined plane and light focussed in the perpendicular plane using cylindrical lenses. (orig.) [de

Engineering Three-dimensional Epithelial Tissues Embedded within Extracellular Matrix.

Science.gov (United States)

Piotrowski-Daspit, Alexandra S; Nelson, Celeste M

2016-07-10

The architecture of branched organs such as the lungs, kidneys, and mammary glands arises through the developmental process of branching morphogenesis, which is regulated by a variety of soluble and physical signals in the microenvironment. Described here is a method created to study the process of branching morphogenesis by forming engineered three-dimensional (3D) epithelial tissues of defined shape and size that are completely embedded within an extracellular matrix (ECM). This method enables the formation of arrays of identical tissues and enables the control of a variety of environmental factors, including tissue geometry, spacing, and ECM composition. This method can also be combined with widely used techniques such as traction force microscopy (TFM) to gain more information about the interactions between cells and their surrounding ECM. The protocol can be used to investigate a variety of cell and tissue processes beyond branching morphogenesis, including cancer invasion.

A two dimensional clinostat experiment for microalgae cultures - basic work for bio- regenerativ life support systems

Science.gov (United States)

Harting, Benjamin; Slenzka, Klaus

2012-07-01

To investigate the influence of microgravity environments on photosynthetic organisms we designed a 2 dimensional clinostatexperiment for a suspended cell culture of Chlamydomonas reinhardtii. A novel approach of online measurments concerning relevant parameters important for the clasification of photosynthesis was obtained. To adress the photosynthesis rate we installed and validated an optical mesurement system to monitor the evolution and consumption of dissolved oxygen. Simultaneously a PAM sensor to analyse the flourescence quantum yield of the photochemical reaction was integarted. Thus it was possible to directly classify important parameters of the phototrophic metabolism during clinorotation. The experiment design including well suited light conditions and further biochemical analysis were directly performed for microalgal cell cultures. Changes in the photosynthetic efficiancy of phototrophic cyanobacteria has been observed during parabolic flight campaign but the cause is already not understood. Explenations could be the dependency of gravitaxis by intracellular ionconcentartion or the existance of mechanosensitive ionchannels for example associated in chloroplasts of Chlamydomonas reinhardtii. The purpuse of the microalgal clinostat are studies in a qasi microgravity environment for the process design of future bioregenerative life suport systems in spaceflight missions. First results has indicated the need for special nourishment of the cell culture during microgravity experiments. Further data will be presented during the assembly.

Topology optimization of two-dimensional waveguides

DEFF Research Database (Denmark)

Jensen, Jakob Søndergaard; Sigmund, Ole

2003-01-01

In this work we use the method of topology optimization to design two-dimensional waveguides with low transmission loss.......In this work we use the method of topology optimization to design two-dimensional waveguides with low transmission loss....

Three-Dimensional Organotypic Co-Culture Model of Intestinal Epithelial Cells and Macrophages to Study "Salmonella Enterica" Colonization Patterns

Science.gov (United States)

Ott, Mark; Yang, J; Barilla, J.; Crabbe, A.; Sarker, S. F.; Liu, Y.

2017-01-01

Three-dimensional/3-D organotypic models of human intestinal epithelium mimic the differentiated form and function of parental tissues often not exhibited by 2-D monolayers and respond to Salmonella in ways that reflect in vivo infections. To further enhance the physiological relevance of 3-D models to more closely approximate in vivo intestinal microenvironments during infection, we developed and validated a novel 3-D intestinal co-culture model containing multiple epithelial cell types and phagocytic macrophages, and applied to study enteric infection by different Salmonella pathovars.

Traditional Semiconductors in the Two-Dimensional Limit.

Science.gov (United States)

Lucking, Michael C; Xie, Weiyu; Choe, Duk-Hyun; West, Damien; Lu, Toh-Ming; Zhang, S B

2018-02-23

Interest in two-dimensional materials has exploded in recent years. Not only are they studied due to their novel electronic properties, such as the emergent Dirac fermion in graphene, but also as a new paradigm in which stacking layers of distinct two-dimensional materials may enable different functionality or devices. Here, through first-principles theory, we reveal a large new class of two-dimensional materials which are derived from traditional III-V, II-VI, and I-VII semiconductors. It is found that in the ultrathin limit the great majority of traditional binary semiconductors studied (a series of 28 semiconductors) are not only kinetically stable in a two-dimensional double layer honeycomb structure, but more energetically stable than the truncated wurtzite or zinc-blende structures associated with three dimensional bulk. These findings both greatly increase the landscape of two-dimensional materials and also demonstrate that in the double layer honeycomb form, even ordinary semiconductors, such as GaAs, can exhibit exotic topological properties.

The role of activated charcoal in plant tissue culture.

Science.gov (United States)

Thomas, T Dennis

2008-01-01

Activated charcoal has a very fine network of pores with large inner surface area on which many substances can be adsorbed. Activated charcoal is often used in tissue culture to improve cell growth and development. It plays a critical role in micropropagation, orchid seed germination, somatic embryogenesis, anther culture, synthetic seed production, protoplast culture, rooting, stem elongation, bulb formation etc. The promotary effects of AC on morphogenesis may be mainly due to its irreversible adsorption of inhibitory compounds in the culture medium and substancially decreasing the toxic metabolites, phenolic exudation and brown exudate accumulation. In addition to this activated charcoal is involved in a number of stimulatory and inhibitory activities including the release of substances naturally present in AC which promote growth, alteration and darkening of culture media, and adsorption of vitamins, metal ions and plant growth regulators, including abscisic acid and gaseous ethylene. The effect of AC on growth regulator uptake is still unclear but some workers believe that AC may gradually release certain adsorbed products, such as nutrients and growth regulators which become available to plants. This review focuses on the various roles of activated charcoal in plant tissue culture and the recent developments in this area.

Sufficient Controllability Condition for Affine Systems with Two-Dimensional Control and Two-Dimensional Zero Dynamics

Directory of Open Access Journals (Sweden)

D. A. Fetisov

2015-01-01

Full Text Available The controllability conditions are well known if we speak about linear stationary systems: a linear stationary system is controllable if and only if the dimension of the state vector is equal to the rank of the controllability matrix. The concept of the controllability matrix is extended to affine systems, but relations between affine systems controllability and properties of this matrix are more complicated. Various controllability conditions are set for affine systems, but they deal as usual either with systems of some special form or with controllability in some small neighborhood of the concerned point. An affine system is known to be controllable if the system is equivalent to a system of a canonical form, which is defined and regular in the whole space of states. In this case, the system is said to be feedback linearizable in the space of states. However there are examples, which illustrate that a system can be controllable even if it is not feedback linearizable in any open subset in the space of states. In this article we deal with such systems.Affine systems with two-dimensional control are considered. The system in question is assumed to be equivalent to a system of a quasicanonical form with two-dimensional zero dynamics which is defined and regular in the whole space of states. Therefore the controllability of the original system is equivalent to the controllability of the received system of a quasicanonical form. In this article the sufficient condition for an available solution of the terminal problem is proven for systems of a quasicanonical form with two-dimensional control and two-dimensional zero dynamics. The condition is valid in the case of an arbitrary time interval and arbitrary initial and finite states of the system. Therefore the controllability condition is set for systems of a quasicanonical form with two-dimensional control and two-dimensional zero dynamics. An example is given which illustrates how the proved

Culture of equine bone marrow mononuclear fraction and adipose tissue-derived stromal vascular fraction cells in different media

Directory of Open Access Journals (Sweden)

Gesiane Ribeiro

2013-12-01

Full Text Available The objective of this study was to evaluate the culture of equine bone marrow mononuclear fraction and adipose tissue - derived stromal vascular fraction cells in two different cell culture media. Five adult horses were submitted to bone marrow aspiration from the sternum, and then from the adipose tissue of the gluteal region near the base of the tail. Mononuclear fraction and stromal vascular fraction were isolated from the samples and cultivated in DMEM medium supplemented with 10% fetal bovine serum or in AIM-V medium. The cultures were observed once a week with an inverted microscope, to perform a qualitative analysis of the morphology of the cells as well as the general appearance of the cell culture. Colony-forming units (CFU were counted on days 5, 15 and 25 of cell culture. During the first week of culture, differences were observed between the samples from the same source maintained in different culture media. The number of colonies was significantly higher in samples of bone marrow in relation to samples of adipose tissue.

Production of immunoglobulins in gingival tissue explant cultures from juvenile periodontitis patients

International Nuclear Information System (INIS)

Hall, E.R.; Falkler, W.A. Jr.; Suzuki, J.B.

1990-01-01

B lymphocytes and plasma cells are histologically observed in granulomatous periodontal tissues of juvenile periodontitis (JP) patients. Local immune processes may participate in protective or immunopathologic roles in the pathogenesis of this disease. An in vitro explant culture system was utilized to demonstrate the production of immunoglobulins by diseased JP tissues. Immunodiffusion studies using goat anti-human gamma, alpha, or mu chain serum revealed IgG to be the major immunoglobulin present in 92% of the day 1 supernatant fluids (SF) of the 47 JP gingival tissue explant cultures. IgA was present in 15% of the SF; however, no IgM was detected. Staph Protein A isolated 14C-labeled IgG from the SF, when allowed to react with goat anti-human gamma chain serum, formed lines of precipitation. Positive autoradiographs confirmed the biosynthesis of IgG by the explant cultures. The in vitro gingival tissue explant culture system described provides a useful model for the study of localized immunoglobulins produced by diseased tissues of JP patients

Production of immunoglobulins in gingival tissue explant cultures from juvenile periodontitis patients

Energy Technology Data Exchange (ETDEWEB)

Hall, E.R.; Falkler, W.A. Jr.; Suzuki, J.B. (Univ. of Maryland Dental School, Baltimore (USA))

1990-10-01

B lymphocytes and plasma cells are histologically observed in granulomatous periodontal tissues of juvenile periodontitis (JP) patients. Local immune processes may participate in protective or immunopathologic roles in the pathogenesis of this disease. An in vitro explant culture system was utilized to demonstrate the production of immunoglobulins by diseased JP tissues. Immunodiffusion studies using goat anti-human gamma, alpha, or mu chain serum revealed IgG to be the major immunoglobulin present in 92% of the day 1 supernatant fluids (SF) of the 47 JP gingival tissue explant cultures. IgA was present in 15% of the SF; however, no IgM was detected. Staph Protein A isolated 14C-labeled IgG from the SF, when allowed to react with goat anti-human gamma chain serum, formed lines of precipitation. Positive autoradiographs confirmed the biosynthesis of IgG by the explant cultures. The in vitro gingival tissue explant culture system described provides a useful model for the study of localized immunoglobulins produced by diseased tissues of JP patients.

Direct Conversion of Equine Adipose-Derived Stem Cells into Induced Neuronal Cells Is Enhanced in Three-Dimensional Culture.

Science.gov (United States)

Petersen, Gayle F; Hilbert, Bryan J; Trope, Gareth D; Kalle, Wouter H J; Strappe, Padraig M

2015-12-01

The ability to culture neurons from horses may allow further investigation into equine neurological disorders. In this study, we demonstrate the generation of induced neuronal cells from equine adipose-derived stem cells (EADSCs) using a combination of lentiviral vector expression of the neuronal transcription factors Brn2, Ascl1, Myt1l (BAM) and NeuroD1 and a defined chemical induction medium, with βIII-tubulin-positive induced neuronal cells displaying a distinct neuronal morphology of rounded and compact cell bodies, extensive neurite outgrowth, and branching of processes. Furthermore, we investigated the effects of dimensionality on neuronal transdifferentiation, comparing conventional two-dimensional (2D) monolayer culture against three-dimensional (3D) culture on a porous polystyrene scaffold. Neuronal transdifferentiation was enhanced in 3D culture, with evenly distributed cells located on the surface and throughout the scaffold. Transdifferentiation efficiency was increased in 3D culture, with an increase in mean percent conversion of more than 100% compared to 2D culture. Additionally, induced neuronal cells were shown to transit through a Nestin-positive precursor state, with MAP2 and Synapsin 2 expression significantly increased in 3D culture. These findings will help to increase our understanding of equine neuropathogenesis, with prospective roles in disease modeling, drug screening, and cellular replacement for treatment of equine neurological disorders.

Current State-of-the-Art 3D Tissue Models and Their Compatibility with Live Cell Imaging.

Science.gov (United States)

Bardsley, Katie; Deegan, Anthony J; El Haj, Alicia; Yang, Ying

2017-01-01

Mammalian cells grow within a complex three-dimensional (3D) microenvironment where multiple cells are organized and surrounded by extracellular matrix (ECM). The quantity and types of ECM components, alongside cell-to-cell and cell-to-matrix interactions dictate cellular differentiation, proliferation and function in vivo. To mimic natural cellular activities, various 3D tissue culture models have been established to replace conventional two dimensional (2D) culture environments. Allowing for both characterization and visualization of cellular activities within possibly bulky 3D tissue models presents considerable challenges due to the increased thickness and subsequent light scattering features of such 3D models. In this chapter, state-of-the-art methodologies used to establish 3D tissue models are discussed, first with a focus on both scaffold-free and scaffold-based 3D tissue model formation. Following on, multiple 3D live cell imaging systems, mainly optical imaging modalities, are introduced. Their advantages and disadvantages are discussed, with the aim of stimulating more research in this highly demanding research area.

Tissue Engineering Applications of Three-Dimensional Bioprinting.

Science.gov (United States)

Zhang, Xiaoying; Zhang, Yangde

2015-07-01

Recent advances in tissue engineering have adapted the additive manufacturing technology, also known as three-dimensional printing, which is used in several industrial applications, for the fabrication of bioscaffolds and viable tissue and/or organs to overcome the limitations of other in vitro conventional methods. 3D bioprinting technology has gained enormous attention as it enabled 3D printing of a multitude of biocompatible materials, different types of cells and other supporting growth factors into complex functional living tissues in a 3D format. A major advantage of this technology is its ability for simultaneously 3D printing various cell types in defined spatial locations, which makes this technology applicable to regenerative medicine to meet the need for suitable for transplantation suitable organs and tissues. 3D bioprinting is yet to successfully overcome the many challenges related to building 3D structures that closely resemble native organs and tissues, which are complex structures with defined microarchitecture and a variety of cell types in a confined area. An integrated approach with a combination of technologies from the fields of engineering, biomaterials science, cell biology, physics, and medicine is required to address these complexities. Meeting this challenge is being made possible by directing the 3D bioprinting to manufacture biomimetic-shaped 3D structures, using organ/tissue images, obtained from magnetic resonance imaging and computerized tomography, and employing computer-aided design and manufacturing technologies. Applications of 3D bioprinting include the generation of multilayered skin, bone, vascular grafts, heart valves, etc. The current 3D bioprinting technologies need to be improved with respect to the mechanical strength and integrity in the manufactured constructs as the presently used biomaterials are not of optimal viscosity. A better understanding of the tissue/organ microenvironment, which consists of multiple types of

Evaluation of reference genes for quantitative real-time PCR in oil palm elite planting materials propagated by tissue culture.

Directory of Open Access Journals (Sweden)

Pek-Lan Chan

Full Text Available BACKGROUND: The somatic embryogenesis tissue culture process has been utilized to propagate high yielding oil palm. Due to the low callogenesis and embryogenesis rates, molecular studies were initiated to identify genes regulating the process, and their expression levels are usually quantified using reverse transcription quantitative real-time PCR (RT-qPCR. With the recent release of oil palm genome sequences, it is crucial to establish a proper strategy for gene analysis using RT-qPCR. Selection of the most suitable reference genes should be performed for accurate quantification of gene expression levels. RESULTS: In this study, eight candidate reference genes selected from cDNA microarray study and literature review were evaluated comprehensively across 26 tissue culture samples using RT-qPCR. These samples were collected from two tissue culture lines and media treatments, which consisted of leaf explants cultures, callus and embryoids from consecutive developmental stages. Three statistical algorithms (geNorm, NormFinder and BestKeeper confirmed that the expression stability of novel reference genes (pOP-EA01332, PD00380 and PD00569 outperformed classical housekeeping genes (GAPDH, NAD5, TUBULIN, UBIQUITIN and ACTIN. PD00380 and PD00569 were identified as the most stably expressed genes in total samples, MA2 and MA8 tissue culture lines. Their applicability to validate the expression profiles of a putative ethylene-responsive transcription factor 3-like gene demonstrated the importance of using the geometric mean of two genes for normalization. CONCLUSIONS: Systematic selection of the most stably expressed reference genes for RT-qPCR was established in oil palm tissue culture samples. PD00380 and PD00569 were selected for accurate and reliable normalization of gene expression data from RT-qPCR. These data will be valuable to the research associated with the tissue culture process. Also, the method described here will facilitate the selection

Evaluation of Reference Genes for Quantitative Real-Time PCR in Oil Palm Elite Planting Materials Propagated by Tissue Culture

Science.gov (United States)

Chan, Pek-Lan; Rose, Ray J.; Abdul Murad, Abdul Munir; Zainal, Zamri; Leslie Low, Eng-Ti; Ooi, Leslie Cheng-Li; Ooi, Siew-Eng; Yahya, Suzaini; Singh, Rajinder

2014-01-01

Background The somatic embryogenesis tissue culture process has been utilized to propagate high yielding oil palm. Due to the low callogenesis and embryogenesis rates, molecular studies were initiated to identify genes regulating the process, and their expression levels are usually quantified using reverse transcription quantitative real-time PCR (RT-qPCR). With the recent release of oil palm genome sequences, it is crucial to establish a proper strategy for gene analysis using RT-qPCR. Selection of the most suitable reference genes should be performed for accurate quantification of gene expression levels. Results In this study, eight candidate reference genes selected from cDNA microarray study and literature review were evaluated comprehensively across 26 tissue culture samples using RT-qPCR. These samples were collected from two tissue culture lines and media treatments, which consisted of leaf explants cultures, callus and embryoids from consecutive developmental stages. Three statistical algorithms (geNorm, NormFinder and BestKeeper) confirmed that the expression stability of novel reference genes (pOP-EA01332, PD00380 and PD00569) outperformed classical housekeeping genes (GAPDH, NAD5, TUBULIN, UBIQUITIN and ACTIN). PD00380 and PD00569 were identified as the most stably expressed genes in total samples, MA2 and MA8 tissue culture lines. Their applicability to validate the expression profiles of a putative ethylene-responsive transcription factor 3-like gene demonstrated the importance of using the geometric mean of two genes for normalization. Conclusions Systematic selection of the most stably expressed reference genes for RT-qPCR was established in oil palm tissue culture samples. PD00380 and PD00569 were selected for accurate and reliable normalization of gene expression data from RT-qPCR. These data will be valuable to the research associated with the tissue culture process. Also, the method described here will facilitate the selection of appropriate

Low technology tissue culture materials for initiation and ...

African Journals Online (AJOL)

Low technology tissue culture materials for initiation and multiplication of banana plants. ... African Crop Science Journal ... locally available macronutrients, micronutrients, sugar, equipment and facility reduced the cost of consumable material

Community transformation through culturally competent nursing leadership: application of theory of culture care diversity and universality and tri-dimensional leader effectiveness model.

Science.gov (United States)

Shapiro, Mina L; Miller, June; White, Kathleen

2006-04-01

Transcultural knowledge and competency have become a critical need for nurses to accommodate the global trends in cultural diversity and health care disparities. Today, nurses are increasingly taking on leadership roles in community settings. This article addresses the application of Leininger's culture care theory with the sunrise model and Hersey and Blanchard's tri-dimensional leader effectiveness model as potential collaborating theories for capacity building and community transformation from a global, transcultural nursing perspective. The two theories, used in collaboration, view the provision of competent leadership as the delivery of effective, culturally congruent nursing care in promoting health and health equity at the community level.

Human meniscal proteoglycan metabolism in long-term tissue culture

NARCIS (Netherlands)

Verbruggen, G.; Verdonk, R.; Veys, E. M.; van Daele, P.; de Smet, P.; van den Abbeele, K.; Claus, B.; Baeten, D.

1996-01-01

For the purpose of human meniscal allografting, menisci have been maintained viable in in vitro culture. The influence of long-term tissue culture on the extracellular matrix metabolism of the meniscus has been studied. Fetal calf serum (FCS) was used as a supplement for the growth factors necessary

Two-dimensional flexible nanoelectronics

Science.gov (United States)

Akinwande, Deji; Petrone, Nicholas; Hone, James

2014-12-01

2014/2015 represents the tenth anniversary of modern graphene research. Over this decade, graphene has proven to be attractive for thin-film transistors owing to its remarkable electronic, optical, mechanical and thermal properties. Even its major drawback--zero bandgap--has resulted in something positive: a resurgence of interest in two-dimensional semiconductors, such as dichalcogenides and buckled nanomaterials with sizeable bandgaps. With the discovery of hexagonal boron nitride as an ideal dielectric, the materials are now in place to advance integrated flexible nanoelectronics, which uniquely take advantage of the unmatched portfolio of properties of two-dimensional crystals, beyond the capability of conventional thin films for ubiquitous flexible systems.

Substituted Indoleacetic Acids Tested in Tissue Cultures

DEFF Research Database (Denmark)

Engvild, Kjeld Christensen

1978-01-01

Monochloro substituted IAA inhibited shoot induction in tobacco tissue cultures about as much as IAA. Dichloro substituted IAA inhibited shoot formation less. Other substituted IAA except 5-fluoro- and 5-bromoindole-3-acetic acid were less active than IAA. Callus growth was quite variable...

21 CFR 864.2220 - Synthetic cell and tissue culture media and components.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Synthetic cell and tissue culture media and components. 864.2220 Section 864.2220 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Cell And Tissue Culture...

Summary of three-dimensional animation creation based on ethnic culture element

Directory of Open Access Journals (Sweden)

Shao Zhaopo

2016-01-01

Full Text Available three-dimensional animation is a product combined by technology and art. It is an artistic ex-pression form combining painting, film & television, digital technology, music, and literature. As an audio and visual art, three-dimensional animation has its own unique culture-loading function, technical aesthetic charac-teristics, and requirements for national art expression. This paper aims to find the method to combine digital technology and national art in combination of three-dimensional animation short film creation, and hopes to clear the road for the cultivation of domestic three-dimensional animation quality project.

Tissue culture of osteogenic sarcoma in rats, induced by radioactive phosphorus P-32 and the effect of the anti-cancerous agents on these tumor cells under tissue culture

International Nuclear Information System (INIS)

Osaka, Shunzo

1976-01-01

Small pieces of osteogenic sarcoma, induced into albino rats of the C.F. Wistar strain by injection of radioactive phosphorus 32 P, were cultured in mixtures of Eagle's minimum essential medium and 20% calf serum. The tumor cells cultured in this way were transplanted into the subcutaneous tissue or the intraabdominal cavity to healthy albino rats. The effect of the anticancerous agents was evaluated by the decrease of nucleic acid composition in these cultured tumor cells. As anti-cancerous agents, cyclophosphamide (CPA), mitomycin C(MMC), and 5-fluorouracil(5-FU) were put into contact with the tumor cells in cultures for two hours under the following dilutions: CPA; 10 -6 , 10 -5 , 10 -4 g/ml. MMC; 2 x 10 -8 , 2 x 10 -7 , 2 x 10 -6 g/ml. 5-FU; 2 x 10 -6 , 2 x 10 -5 , 2 x 10 -4 g/ml. The results are as follows: Three of the seven osteogenic sarcomas in rats were successfully cultured, one of them through more than eighteen generations. After about five hundred thousand cultured cells had been transplanted into the subcutaneous tissues or abdominal cavities of rats, tumors grew in all of them. The histological findings of the tumors in the second generation were quite similar to those of the original tumor. The same process was repeated three times and the tumor showed histogical findings similar to those of the original ones. The capability of nucleic acid synthesis in these cells was decreased at twenty fours after CPA contact and at forty eight hours after MMC. (J.P.N.)

Three-dimensional structure of brain tissue at submicrometer resolution

Energy Technology Data Exchange (ETDEWEB)

Saiga, Rino; Mizutani, Ryuta, E-mail: ryuta@tokai-u.jp [Department of Applied Biochemistry, Tokai University, Hiratsuka, Kanagawa 259-1292 (Japan); Inomoto, Chie; Takekoshi, Susumu; Nakamura, Naoya; Tsuboi, Akio; Osawa, Motoki [Tokai University School of Medicine, Isehara, Kanagawa 259-1193 (Japan); Arai, Makoto; Oshima, Kenichi; Itokawa, Masanari [Tokyo Metropolitan Institute of Medical Science, Setagaya, Tokyo 156-8506 (Japan); Uesugi, Kentaro; Takeuchi, Akihisa; Terada, Yasuko; Suzuki, Yoshio [Japan Synchrotron Radiation Research Institute (JASRI/SPring-8), Sayo, Hyogo 679-5198 (Japan)

2016-01-28

Biological objects are composed of submicrometer structures such as cells and organelles that are essential for their functions. Here, we report on three-dimensional X-ray visualization of cells and organelles at resolutions up to 100 nm by imaging microtomography (micro-CT) equipped with Fresnel zone plate optics. Human cerebral tissue, fruit fly cephalic ganglia, and Escherichia coli bacteria labeled with high atomic-number elements were embedded in epoxy resin and subjected to X-ray microtomography at the BL37XU and BL47XU beamlines of the SPring-8 synchrotron radiation facility. The obtained results indicated that soft tissue structures can be visualized with the imaging microtomography.

Approximate solutions for the two-dimensional integral transport equation. Solution of complex two-dimensional transport problems

International Nuclear Information System (INIS)

Sanchez, Richard.

1980-11-01

This work is divided into two parts: the first part deals with the solution of complex two-dimensional transport problems, the second one (note CEA-N-2166) treats the critically mixed methods of resolution. A set of approximate solutions for the isotropic two-dimensional neutron transport problem has been developed using the interface current formalism. The method has been applied to regular lattices of rectangular cells containing a fuel pin, cladding, and water, or homogenized structural material. The cells are divided into zones that are homogeneous. A zone-wise flux expansion is used to formulate a direct collision probability problem within a cell. The coupling of the cells is effected by making extra assumptions on the currents entering and leaving the interfaces. Two codes have been written: CALLIOPE uses a cylindrical cell model and one or three terms for the flux expansion, and NAUSICAA uses a two-dimensional flux representation and does a truly two-dimensional calculation inside each cell. In both codes, one or three terms can be used to make a space-independent expansion of the angular fluxes entering and leaving each side of the cell. The accuracies and computing times achieved with the different approximations are illustrated by numerical studies on two benchmark problems and by calculations performed in the APOLLO multigroup code [fr

In vitro expansion and differentiation of rat pancreatic duct-derived stem cells into insulin secreting cells using a dynamicthree-dimensional cell culture system.

Science.gov (United States)

Chen, X C; Liu, H; Li, H; Cheng, Y; Yang, L; Liu, Y F

2016-06-27

In this study, a dynamic three-dimensional cell culture technology was used to expand and differentiate rat pancreatic duct-derived stem cells (PDSCs) into islet-like cell clusters that can secrete insulin. PDSCs were isolated from rat pancreatic tissues by in situ collagenase digestion and density gradient centrifugation. Using a dynamic three-dimensional culture technique, the cells were expanded and differentiated into functional islet-like cell clusters, which were characterized by morphological and phenotype analyses. After maintaining 1 x 108 isolated rat PDSCs in a dynamic three-dimensional cell culture for 7 days, 1.5 x 109 cells could be harvested. Passaged PDSCs expressed markers of pancreatic endocrine progenitors, including CD29 (86.17%), CD73 (90.73%), CD90 (84.13%), CD105 (78.28%), and Pdx-1. Following 14 additional days of culture in serum-free medium with nicotinamide, keratinocyte growth factor (KGF), and b fibroblast growth factor (FGF), the cells were differentiated into islet-like cell clusters (ICCs). The ICC morphology reflected that of fused cell clusters. During the late stage of differentiation, representative clusters were non-adherent and expressed insulin indicated by dithizone (DTZ)-positive staining. Insulin was detected in the extracellular fluid and cytoplasm of ICCs after 14 days of differentiation. Additionally, insulin levels were significantly higher at this time compared with the levels exhibited by PDSCs before differentiation (P cell culture system, PDSCs can be expanded in vitro and can differentiate into functional islet-like cell clusters.

Two-dimensional topological field theories coupled to four-dimensional BF theory

International Nuclear Information System (INIS)

Montesinos, Merced; Perez, Alejandro

2008-01-01

Four-dimensional BF theory admits a natural coupling to extended sources supported on two-dimensional surfaces or string world sheets. Solutions of the theory are in one to one correspondence with solutions of Einstein equations with distributional matter (cosmic strings). We study new (topological field) theories that can be constructed by adding extra degrees of freedom to the two-dimensional world sheet. We show how two-dimensional Yang-Mills degrees of freedom can be added on the world sheet, producing in this way, an interactive (topological) theory of Yang-Mills fields with BF fields in four dimensions. We also show how a world sheet tetrad can be naturally added. As in the previous case the set of solutions of these theories are contained in the set of solutions of Einstein's equations if one allows distributional matter supported on two-dimensional surfaces. These theories are argued to be exactly quantizable. In the context of quantum gravity, one important motivation to study these models is to explore the possibility of constructing a background-independent quantum field theory where local degrees of freedom at low energies arise from global topological (world sheet) degrees of freedom at the fundamental level

Ocular Proteomics with Emphasis on Two-Dimensional Gel Electrophoresis and Mass Spectrometry

Directory of Open Access Journals (Sweden)

Honoré Bent

2010-01-01

Full Text Available Abstract The intention of this review is to provide an overview of current methodologies employed in the rapidly developing field of ocular proteomics with emphasis on sample preparation, two-dimensional polyacrylamide gel electrophoresis (2D-PAGE and mass spectrometry (MS. Appropriate sample preparation for the diverse range of cells and tissues of the eye is essential to ensure reliable results. Current methods of protein staining for 2D-PAGE, protein labelling for two-dimensional difference gel electrophoresis, gel-based expression analysis and protein identification by MS are summarised. The uses of gel-free MS-based strategies (MuDPIT, iTRAQ, ICAT and SILAC are also discussed. Proteomic technologies promise to shed new light onto ocular disease processes that could lead to the discovery of strong novel biomarkers and therapeutic targets useful in many ophthalmic conditions.

Beginning Introductory Physics with Two-Dimensional Motion

Science.gov (United States)

Huggins, Elisha

2009-01-01

During the session on "Introductory College Physics Textbooks" at the 2007 Summer Meeting of the AAPT, there was a brief discussion about whether introductory physics should begin with one-dimensional motion or two-dimensional motion. Here we present the case that by starting with two-dimensional motion, we are able to introduce a considerable…

Two-dimensional thermofield bosonization

International Nuclear Information System (INIS)

Amaral, R.L.P.G.; Belvedere, L.V.; Rothe, K.D.

2005-01-01

The main objective of this paper was to obtain an operator realization for the bosonization of fermions in 1 + 1 dimensions, at finite, non-zero temperature T. This is achieved in the framework of the real-time formalism of Thermofield Dynamics. Formally, the results parallel those of the T = 0 case. The well-known two-dimensional Fermion-Boson correspondences at zero temperature are shown to hold also at finite temperature. To emphasize the usefulness of the operator realization for handling a large class of two-dimensional quantum field-theoretic problems, we contrast this global approach with the cumbersome calculation of the fermion-current two-point function in the imaginary-time formalism and real-time formalisms. The calculations also illustrate the very different ways in which the transmutation from Fermi-Dirac to Bose-Einstein statistics is realized

Printing three-dimensional tissue analogues with decellularized extracellular matrix bioink

Science.gov (United States)

Pati, Falguni; Jang, Jinah; Ha, Dong-Heon; Won Kim, Sung; Rhie, Jong-Won; Shim, Jin-Hyung; Kim, Deok-Ho; Cho, Dong-Woo

2014-06-01

The ability to print and pattern all the components that make up a tissue (cells and matrix materials) in three dimensions to generate structures similar to tissues is an exciting prospect of bioprinting. However, the majority of the matrix materials used so far for bioprinting cannot represent the complexity of natural extracellular matrix (ECM) and thus are unable to reconstitute the intrinsic cellular morphologies and functions. Here, we develop a method for the bioprinting of cell-laden constructs with novel decellularized extracellular matrix (dECM) bioink capable of providing an optimized microenvironment conducive to the growth of three-dimensional structured tissue. We show the versatility and flexibility of the developed bioprinting process using tissue-specific dECM bioinks, including adipose, cartilage and heart tissues, capable of providing crucial cues for cells engraftment, survival and long-term function. We achieve high cell viability and functionality of the printed dECM structures using our bioprinting method.

Two-dimensional x-ray diffraction

CERN Document Server

He, Bob B

2009-01-01

Written by one of the pioneers of 2D X-Ray Diffraction, this useful guide covers the fundamentals, experimental methods and applications of two-dimensional x-ray diffraction, including geometry convention, x-ray source and optics, two-dimensional detectors, diffraction data interpretation, and configurations for various applications, such as phase identification, texture, stress, microstructure analysis, crystallinity, thin film analysis and combinatorial screening. Experimental examples in materials research, pharmaceuticals, and forensics are also given. This presents a key resource to resea

Three-dimensional analysis and classification of arteries in the skin and subcutaneous adipofascial tissue by computer graphics imaging.

Science.gov (United States)

Nakajima, H; Minabe, T; Imanishi, N

1998-09-01

To develop new types of surgical flaps that utilize portions of the skin and subcutaneous tissue (e.g., a thin flap or an adipofascial flap), three-dimensional investigation of the vasculature in the skin and subcutaneous tissue has been anticipated. In the present study, total-body arterial injection and three-dimensional imaging of the arteries by computer graphics were performed. The full-thickness skin and subcutaneous adipofascial tissue samples, which were obtained from fresh human cadavers injected with radio-opaque medium, were divided into three distinct layers. Angiograms of each layer were introduced into a personal computer to construct three-dimensional images. On a computer monitor, each artery was shown color-coded according to the three portions: the deep adipofascial layer, superficial adipofascial layer, and dermis. Three-dimensional computerized images of each artery in the skin and subcutaneous tissue revealed the components of each vascular plexus and permitted their classification into six types. The distribution of types in the body correlated with the tissue mobility of each area. Clinically, appreciation of the three-dimensional structure of the arteries allowed the development of several new kinds of flaps.

Three-dimensional bone tissue substitute based on a human mesenchymal stem cell culture on a nanofiber carrier and inorganic matrix

Directory of Open Access Journals (Sweden)

Martin Krbec

2016-01-01

Full Text Available The aim was to construct a composite structure for bone tissue substitute on the basis of a degradable composite of an organic nanofiber carrier and an inorganic matrix in 3D, and to achieve subsequent colonisation by differentiated human mesenchymal stem cells (hMSC towards osteocytes. We developed an active bone tissue substitute using nanofiber technology for a polycaprolactone (PCL scaffold with the addition of hydroxyapatite and the colonisation of both components with hMSC with the ability of differentiation towards osteocytes. The constructed composition included the components necessary for bone healing (inorganic and cellular and it also forms a spatially-oriented 3D structure. We used polycaprolactone Mw 70,000 with electrostatic spinning for the formation of nanofibers using a modified NanospiderTM method. For the inorganic component we used orthophosphate-calcium silicate with a crystal size of 1-2 mm which the nanofiber membrane was coated with. Both components were connected together with a tissue adhesive based of fibrin glue. Cultivated hMSC cells at a concentration of 1.2 × 104/cm2 were multiplied in vitro and then cultivated in the expansion medium. HMSC overgrew both the PCL membrane and the Si-CaP crystals. After colonisation with cultivated cells, this composite 3D structure can serve as a three-dimensional bone tissue replacement.

Piezoelectricity in Two-Dimensional Materials

KAUST Repository

Wu, Tao

2015-02-25

Powering up 2D materials: Recent experimental studies confirmed the existence of piezoelectricity - the conversion of mechanical stress into electricity - in two-dimensional single-layer MoS2 nanosheets. The results represent a milestone towards embedding low-dimensional materials into future disruptive technologies. © 2015 Wiley-VCH Verlag GmbH & Co. KGaA.

The basic design and requirement for plant tissue culture laboratory in MINT

International Nuclear Information System (INIS)

Azraf Azman; Rosli Darmawan; Rusli Ibrahim; Mohd Nazir Basiran; Azhar Mohamad; Mohamed Najli Mohamed Yasin; Shuhaimi Shamsuddin

2005-01-01

The production of multiple species plantlets involves a relatively complex process and it is a highly specialized operation. Tissue culture technology is rapidly becoming a commercialized method for propagating new cultivars, rare species and difficult-to-propagate plant. Not only are skills and knowledge essential but the laboratory itself also plays an important role to ensure the successful growth of the plantlets. To produce quality plantlets, plant tissue culture laboratories should fulfill the basic requirements. The laboratory should have proper building and layout which comprise of media preparation and washing room, sterilization or autoclave room, transfer room and culture or growth room. The scope of this paper is to compare these fundamental requirements with the plant tissue culture laboratory in MINT. All the basic needs and differences will be discussed and the proposal for corrective actions will be presented. (Author)

Application of Synthetic Polymeric Scaffolds in Breast Cancer 3D Tissue Cultures and Animal Tumor Models

Directory of Open Access Journals (Sweden)

Girdhari Rijal

2017-01-01

Full Text Available Preparation of three-dimensional (3D porous scaffolds from synthetic polymers is a challenge to most laboratories conducting biomedical research. Here, we present a handy and cost-effective method to fabricate polymeric hydrogel and porous scaffolds using poly(lactic-co-glycolic acid (PLGA or polycaprolactone (PCL. Breast cancer cells grown on 3D polymeric scaffolds exhibited distinct survival, morphology, and proliferation compared to those on 2D polymeric surfaces. Mammary epithelial cells cultured on PLGA- or PCL-coated slides expressed extracellular matrix (ECM proteins and their receptors. Estrogen receptor- (ER- positive T47D breast cancer cells are less sensitive to 4-hydroxytamoxifen (4-HT treatment when cultured on the 3D porous scaffolds than in 2D cultures. Finally, cancer cell-laden polymeric scaffolds support consistent tumor formation in animals and biomarker expression as seen in human native tumors. Our data suggest that the porous synthetic polymer scaffolds satisfy the basic requirements for 3D tissue cultures both in vitro and in vivo. The scaffolding technology has appealing potentials to be applied in anticancer drug screening for a better control of the progression of human cancers.

Application of Fluorescence Two-Dimensional Difference In-Gel Electrophoresis as a Proteomic Biomarker Discovery Tool in Muscular Dystrophy Research

Science.gov (United States)

Carberry, Steven; Zweyer, Margit; Swandulla, Dieter; Ohlendieck, Kay

2013-01-01

In this article, we illustrate the application of difference in-gel electrophoresis for the proteomic analysis of dystrophic skeletal muscle. The mdx diaphragm was used as a tissue model of dystrophinopathy. Two-dimensional gel electrophoresis is a widely employed protein separation method in proteomic investigations. Although two-dimensional gels usually underestimate the cellular presence of very high molecular mass proteins, integral membrane proteins and low copy number proteins, this method is extremely powerful in the comprehensive analysis of contractile proteins, metabolic enzymes, structural proteins and molecular chaperones. This gives rise to two-dimensional gel electrophoretic separation as the method of choice for studying contractile tissues in health and disease. For comparative studies, fluorescence difference in-gel electrophoresis has been shown to provide an excellent biomarker discovery tool. Since aged diaphragm fibres from the mdx mouse model of Duchenne muscular dystrophy closely resemble the human pathology, we have carried out a mass spectrometry-based comparison of the naturally aged diaphragm versus the senescent dystrophic diaphragm. The proteomic comparison of wild type versus mdx diaphragm resulted in the identification of 84 altered protein species. Novel molecular insights into dystrophic changes suggest increased cellular stress, impaired calcium buffering, cytostructural alterations and disturbances of mitochondrial metabolism in dystrophin-deficient muscle tissue. PMID:24833232

Use of 15N reverse gradient two-dimensional nuclear magnetic resonance spectroscopy to follow metabolic activity in Nicotiana plumbaginifolia cell-suspension cultures.

Science.gov (United States)

Mesnard, F; Azaroual, N; Marty, D; Fliniaux, M A; Robins, R J; Vermeersch, G; Monti, J P

2000-02-01

Nitrogen metabolism was monitored in suspension cultured cells of Nicotiana plumbaginifolia Viv. using nuclear magnetic resonance (NMR) spectroscopy following the feeding of (15NH4)2SO4 and K15NO3. By using two-dimensional 15N-1H NMR with heteronuclear single-quantum-coherence spectroscopy and heteronuclear multiple-bond-coherence spectroscopy sequences, an enhanced resolution of the incorporation of 15N label into a range of compounds could be detected. Thus, in addition to the amino acids normally observed in one-dimensional 15N NMR (glutamine, aspartate, alanine), several other amino acids could be resolved, notably serine, glycine and proline. Furthermore, it was found that the peak normally assigned to the non-protein amino-acid gamma-aminobutyric acid in the one-dimensional 15N NMR spectrum was resolved into a several components. A peak of N-acetylated compounds was resolved, probably composed of the intermediates in arginine biosynthesis, N-acetylglutamate and N-acetylornithine and, possibly, the intermediate of putrescine degradation into gamma-aminobutyric acid, N-acetylputrescine. The occurrence of 15N-label in agmatine and the low detection of labelled putrescine indicate that crucial intermediates of the pathway from glutamate to polyamines and/or the tobacco alkaloids could be monitored. For the first time, labelling of the peptide glutathione and of the nucleotide uridine could be seen.

Noninvasive Real-Time Assessment of Cell Viability in a Three-Dimensional Tissue.

Science.gov (United States)

Mahfouzi, Seyed Hossein; Amoabediny, Ghassem; Doryab, Ali; Safiabadi-Tali, Seyed Hamid; Ghanei, Mostafa

2018-04-01

Maintaining cell viability within 3D tissue engineering scaffolds is an essential step toward a functional tissue or organ. Assessment of cell viability in 3D scaffolds is necessary to control and optimize tissue culture process. Monitoring systems based on respiration activity of cells (e.g., oxygen consumption) have been used in various cell cultures. In this research, an online monitoring system based on respiration activity was developed to monitor cell viability within acellular lung scaffolds. First, acellular lung scaffolds were recellularized with human umbilical cord vein endothelial cells, and then, cell viability was monitored during a 5-day period. The real-time monitoring system generated a cell growth profile representing invaluable information on cell viability and proliferative states during the culture period. The cell growth profile obtained by the monitoring system was consistent with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide analysis and glucose consumption measurement. This system provided a means for noninvasive, real-time, and repetitive investigation of cell viability. Also, we showed the applicability of this monitoring system by introducing shaking as an operating parameter in a long-term culture.

Structure and component alteration of rabbit Achilles tendon in tissue culture.

Science.gov (United States)

Hosaka, Yoshinao; Ueda, Hiromi; Yamasaki, Tadatsugu; Suzuki, Daisuke; Matsuda, Naoya; Takehana, Kazushige

2005-12-01

The aim of this study was to investigate alterations of cultured tendon tissues to determine whether tissue culture is a useful method for biological analyses of the tendon. Tendon tissues for tissue culture were isolated from Achilles tendons of rabbits. The tendon segments were placed one segment per well and incubated in growth medium consisting of Dullbecco's modified Eagle's medium supplemented with 5% fetal bovine serum at 37 degrees C in a humidified atmosphere with 5% CO(2) for various periods. The alignment of collagen fibrils was preserved for 48 h, but tendon structure has disintegrated at 96 h. Alcian blue staining and gelatine zymography revealed that proteoglycan markedly diminished and that matrix metalloproteinase (MMPs) activity was upregulated sharply at 72 and 96 h. The ratio of collagen fibrils with large diameter had increased and the mean diameter and mass average diameter value had reached maximum at 48 h. The values then decreased and mean diameters at 72 and 96 h were significantly different from that at 48 h. At 96 h, the ratio of collagen fibrils with small diameters had increased and collagen fibrils with large diameters had disappeared. These findings indicate that structural alteration is possible to be induced by disintegration of collagen fibrils and disappearance of glycosaminoglycans from extracellular matrix (ECM), subsequent of upregulation of MMPs activity. Although the study period is limited, the tissue culture method is available for investigating cell-ECM interaction in tendons.

Two-dimensional confinement of heavy fermions

International Nuclear Information System (INIS)

Shishido, Hiroaki; Shibauchi, Takasada; Matsuda, Yuji; Terashima, Takahito

2010-01-01

Metallic systems with the strongest electron correlations are realized in certain rare-earth and actinide compounds whose physics are dominated by f-electrons. These materials are known as heavy fermions, so called because the effective mass of the conduction electrons is enhanced via correlation effects up to as much as several hundreds times the free electron mass. To date the electronic structure of all heavy-fermion compounds is essentially three-dimensional. Here we report on the first realization of a two-dimensional heavy-fermion system, where the dimensionality is adjusted in a controllable fashion by fabricating heterostructures using molecular beam epitaxy. The two-dimensional heavy fermion system displays striking deviations from the standard Fermi liquid low-temperature electronic properties. (author)

Quantifying the correlation between spatially defined oxygen gradients and cell fate in an engineered three-dimensional culture model.

Science.gov (United States)

Ardakani, Amir G; Cheema, Umber; Brown, Robert A; Shipley, Rebecca J

2014-09-06

A challenge in three-dimensional tissue culture remains the lack of quantitative information linking nutrient delivery and cellular distribution. Both in vivo and in vitro, oxygen is delivered by diffusion from its source (blood vessel or the construct margins). The oxygen level at a defined distance from its source depends critically on the balance of diffusion and cellular metabolism. Cells may respond to this oxygen environment through proliferation, death and chemotaxis, resulting in spatially resolved gradients in cellular density. This study extracts novel spatially resolved and simultaneous data on tissue oxygenation, cellular proliferation, viability and chemotaxis in three-dimensional spiralled, cellular collagen constructs. Oxygen concentration gradients drove preferential cellular proliferation rates and viability in the higher oxygen zones and induced chemotaxis along the spiral of the collagen construct; an oxygen gradient of 1.03 mmHg mm(-1) in the spiral direction induced a mean migratory speed of 1015 μm day(-1). Although this movement was modest, it was effective in balancing the system to a stable cell density distribution, and provided insights into the natural cell mechanism for adapting cell number and activity to a prevailing oxygen regime.

Leading research report for fiscal 1998. Research and study of 3-dimensional cell structure module engineering; 1998 nendo sendo chosa kenkyu hokokusho. Sanjigen saibo soshiki module kogaku chosa kenkyu

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-03-01

For the formation of cellular tissues to replace bionic tissues, researches were conducted about technologies of forming bionic tissue modules by culturing various kinds of cells. As for the materials and methods for constructing cellular tissues, researches were conducted about the trends of research and development of 3-dimensional tissue culturing matrices and materials for micromanipulation. As for the development of technologies for the functionalization of 3-dimensionally structured cells, research and study were conducted about the technology of 3-dimensional cell structure organization through application of physical stimulation, the biochemical technology of differentiation inducing, and the differentiation inducing technology for hetero tissue culturing. As for the development of technologies for evaluation using 3-dimensionally structured cells, light CT (computer tomography), analysis and evaluation using spectroscopy and the like, feasibility of the biochemical analysis of the cell state using biosensors, technologies for measuring the secretion of carcinogenic and toxic substances, etc., were studied. In addition, the development of organic models to replace test animals, industrial evolution of 3-dimensional tissue module engineering, etc., were investigated. (NEDO)

Two-dimensional topological photonics

Science.gov (United States)

Khanikaev, Alexander B.; Shvets, Gennady

2017-12-01

Originating from the studies of two-dimensional condensed-matter states, the concept of topological order has recently been expanded to other fields of physics and engineering, particularly optics and photonics. Topological photonic structures have already overturned some of the traditional views on wave propagation and manipulation. The application of topological concepts to guided wave propagation has enabled novel photonic devices, such as reflection-free sharply bent waveguides, robust delay lines, spin-polarized switches and non-reciprocal devices. Discrete degrees of freedom, widely used in condensed-matter physics, such as spin and valley, are now entering the realm of photonics. In this Review, we summarize the latest advances in this highly dynamic field, with special emphasis on the experimental work on two-dimensional photonic topological structures.

Three-dimensional Huh7 cell culture system for the study of Hepatitis C virus infection

Directory of Open Access Journals (Sweden)

Uprichard Susan L

2009-07-01

Full Text Available Abstract Background In order to elucidate how Hepatitis C Virus (HCV interacts with polarized hepatocytes in vivo and how HCV-induced alterations in cellular function contribute to HCV-associated liver disease, a more physiologically relevant hepatocyte culture model is needed. As such, NASA-engineered three-dimensional (3-D rotating wall vessel (RWV bioreactors were used in effort to promote differentiation of HCV-permissive Huh7 hepatoma cells. Results When cultured in the RWV, Huh7 cells became morphologically and transcriptionally distinct from more standard Huh7 two-dimensional (2-D monolayers. Specifically, RWV-cultured Huh7 cells formed complex, multilayered 3-D aggregates in which Phase I and Phase II xenobiotic drug metabolism genes, as well as hepatocyte-specific transcripts (HNF4α, Albumin, TTR and α1AT, were upregulated compared to 2-D cultured Huh7 cells. Immunofluorescence analysis revealed that these HCV-permissive 3-D cultured Huh7 cells were more polarized than their 2D counterparts with the expression of HCV receptors, cell adhesion and tight junction markers (CD81, scavenger receptor class B member 1, claudin-1, occludin, ZO-1, β-Catenin and E-Cadherin significantly increased and exhibiting apical, lateral and/or basolateral localization. Conclusion These findings show that when cultured in 3-D, Huh7 cells acquire a more differentiated hepatocyte-like phenotype. Importantly, we show that these 3D cultures are highly permissive for HCV infection, thus providing an opportunity to study HCV entry and the effects of HCV infection on host cell function in a more physiologically relevant cell culture system.

Structures of two-dimensional three-body systems

International Nuclear Information System (INIS)

Ruan, W.Y.; Liu, Y.Y.; Bao, C.G.

1996-01-01

Features of the structure of L = 0 states of a two-dimensional three-body model system have been investigated. Three types of permutation symmetry of the spatial part, namely symmetric, antisymmetric, and mixed, have been considered. A comparison has been made between the two-dimensional system and the corresponding three-dimensional one. The effect of symmetry on microscopic structures is emphasized. (author)

Heritability of regeneration in tissue cultures of sweet potato (Ipomoea batatas L.).

Science.gov (United States)

Templeton-Somers, K M; Collins, W W

1986-03-01

A population of open-pollinated progeny from 12 parents, and the 12 parents, was surveyed for in vitro growth and regeneration characteristics. Four different tissue culture procedures involving different media and the use of different explants to initiate the cultures were used. Petiole explants from young leaves were used as explants for initiation of callus cultures. These were evaluated for callus growth rate, friability, and callus color and texture, before transferring to each of three different regeneration media for evaluation of morphogenetic potential. Small shoot tips also were used to initiate callus cultures, which were evaluated for the same growth characteristics and transferred to growth-regulator free regeneration media. Regeneration occurred through root or shoot regeneration or through embryogenesis. Tissue culture treatment effects, as well as genotypic effects, were highly significant in determining: the types of callus produced, callus growth rates, color and texture on the two types of media used for the second and third subcultures. The family x treatment interaction was generally not statistically significant, affecting only callus color. Estimates of narrow sense heritability for callus growth rate in both the second and third subcultures were high enough (0.35 and 0.63, respectively) for the evaluation of parental lines for selection procedures. These characteristics were also the only early culture callus traits that were consistently correlated with later morphogenesis of the cultures. They were negatively correlated with root or shoot regeneration. The occurence of somatic embryogenesis was not correlated with early callus growth characteristics. Genetic and treatment effects were highly significant in the evaluation of morphogenetic potential, through root or shoot regeneration, or through embryogenesis. Regeneration of all types was of low frequency for all procedures, expressed in ≦ 11% of the cultures of the total population.

Expression of Raf kinase inhibitor protein in human hepatoma tissues by two-dimensional gel electrophoresis and matrix-assisted laser desorption/ionization time-of-flight methods.

Science.gov (United States)

Tsao, D A; Shiau, Y F; Tseng, C S; Chang, H R

2016-01-01

Hepatocellular carcinoma (HCC) is the most common malignant liver tumor. To reduce the mortality and improve the effectiveness of therapy, it is important to search for changes in tumor-specific biomarkers whose function may involve in disease progression and which may be useful as potential therapeutic targets. Materials and Mehtods: In this study, we use two-dimensional polyacrylamide gel electrophoresis (2-DE) and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry to observe proteome alterations of 12 tissue pairs isolated from HCC patients: Normal and tumorous tissue. Comparing the tissue types with each other, 40 protein spots corresponding to fifteen differentially expressed between normal and cancer part of HCC patients. Raf kinase inhibitor protein (RKIP), an inhibitor of Raf-mediated activation of mitogen-activated protein kinase/extracellular signal-regulated kinase, may play an important role in cancer metastasis and cell proliferation and migration of human hepatoma cells. RKIP may be considered as a marker for HCC, because its expression level changes considerably in HCC compared with normal tissue. In addition, we used the methods of Western blotting and real time-polymerase chain reaction to analysis the protein expression and gene expression of RKIP. The result showed RKIP protein and gene expression in tumor part liver tissues of HCC patient is lower than peritumorous non-neoplastic liver tissue of the corresponding HCC samples. These results strongly suggest that RKIP may be considered to be a marker for HCC and RKIP are down-regulated in liver cancer cell.

X-ray imaging device for one-dimensional and two-dimensional radioscopy

International Nuclear Information System (INIS)

1978-01-01

The X-ray imaging device for the selectable one-dimensional or two-dimensional pictures of objects illuminated by X-rays, comprising an X-ray source, an X-ray screen, and an opto-electrical picture development device placed behind the screen, is characterized by an anamorphotic optical system, which is positioned with a one-dimensional illumination between the X-ray screen and the opto-electrical device and that a two-dimensional illumination will be developed, and that in view of the lens system which forms part of the opto-electrical device, there is placed an X-ray screen in a specified beam direction so that a magnified image may be formed by equalisation of the distance between the X-ray screen and the lens system. (G.C.)

Hamiltonian formalism of two-dimensional Vlasov kinetic equation.

Science.gov (United States)

Pavlov, Maxim V

2014-12-08

In this paper, the two-dimensional Benney system describing long wave propagation of a finite depth fluid motion and the multi-dimensional Russo-Smereka kinetic equation describing a bubbly flow are considered. The Hamiltonian approach established by J. Gibbons for the one-dimensional Vlasov kinetic equation is extended to a multi-dimensional case. A local Hamiltonian structure associated with the hydrodynamic lattice of moments derived by D. J. Benney is constructed. A relationship between this hydrodynamic lattice of moments and the two-dimensional Vlasov kinetic equation is found. In the two-dimensional case, a Hamiltonian hydrodynamic lattice for the Russo-Smereka kinetic model is constructed. Simple hydrodynamic reductions are presented.

Novel target design algorithm for two-dimensional optical storage (TwoDOS)

NARCIS (Netherlands)

Huang, Li; Chong, T.C.; Vijaya Kumar, B.V.K.; Kobori, H.

2004-01-01

In this paper we introduce the Hankel transform based channel model of Two-Dimensional Optical Storage (TwoDOS) system. Based on this model, the two-dimensional (2D) minimum mean-square error (MMSE) equalizer has been derived and applied to some simple but common cases. The performance of the 2D

Two-dimensional ferroelectrics

Energy Technology Data Exchange (ETDEWEB)

Blinov, L M; Fridkin, Vladimir M; Palto, Sergei P [A.V. Shubnikov Institute of Crystallography, Russian Academy of Sciences, Moscow, Russian Federaion (Russian Federation); Bune, A V; Dowben, P A; Ducharme, Stephen [Department of Physics and Astronomy, Behlen Laboratory of Physics, Center for Materials Research and Analysis, University of Nebraska-Linkoln, Linkoln, NE (United States)

2000-03-31

The investigation of the finite-size effect in ferroelectric crystals and films has been limited by the experimental conditions. The smallest demonstrated ferroelectric crystals had a diameter of {approx}200 A and the thinnest ferroelectric films were {approx}200 A thick, macroscopic sizes on an atomic scale. Langmuir-Blodgett deposition of films one monolayer at a time has produced high quality ferroelectric films as thin as 10 A, made from polyvinylidene fluoride and its copolymers. These ultrathin films permitted the ultimate investigation of finite-size effects on the atomic thickness scale. Langmuir-Blodgett films also revealed the fundamental two-dimensional character of ferroelectricity in these materials by demonstrating that there is no so-called critical thickness; films as thin as two monolayers (1 nm) are ferroelectric, with a transition temperature near that of the bulk material. The films exhibit all the main properties of ferroelectricity with a first-order ferroelectric-paraelectric phase transition: polarization hysteresis (switching); the jump in spontaneous polarization at the phase transition temperature; thermal hysteresis in the polarization; the increase in the transition temperature with applied field; double hysteresis above the phase transition temperature; and the existence of the ferroelectric critical point. The films also exhibit a new phase transition associated with the two-dimensional layers. (reviews of topical problems)

Smallholder adoption and economic impacts of tissue culture ...

African Journals Online (AJOL)

PRECIOUS

2009-12-01

Dec 1, 2009 ... ISSN 1684–5315 © 2009 Academic Journals. Full Length ... Key words: Biotechnology, adoption, tissue culture bananas, Kenya. INTRODUCTION ... Recent studies about the agronomic and economic impacts of biotech- ..... accused scientist for 'playing God', others have supported biotechnologies.

Methods of Monitoring Cell Fate and Tissue Growth in Three-Dimensional Scaffold-Based Strategies for In Vitro Tissue Engineering.

Science.gov (United States)

Leferink, Anne M; van Blitterswijk, Clemens A; Moroni, Lorenzo

2016-08-01

In the field of tissue engineering, there is a need for methods that allow assessing the performance of tissue-engineered constructs noninvasively in vitro and in vivo. To date, histological analysis is the golden standard to retrieve information on tissue growth, cellular distribution, and cell fate on tissue-engineered constructs after in vitro cell culture or on explanted specimens after in vivo applications. Yet, many advances have been made to optimize imaging techniques for monitoring tissue-engineered constructs with a sub-mm or μm resolution. Many imaging modalities have first been developed for clinical applications, in which a high penetration depth has been often more important than lateral resolution. In this study, we have reviewed the current state of the art in several imaging approaches that have shown to be promising in monitoring cell fate and tissue growth upon in vitro culture. Depending on the aimed tissue type and scaffold properties, some imaging methods are more applicable than others. Optical methods are mostly suited for transparent materials such as hydrogels, whereas magnetic resonance-based methods are mostly applied to obtain contrast between hard and soft tissues regardless of their transparency. Overall, this review shows that the field of imaging in scaffold-based tissue engineering is developing at a fast pace and has the potential to overcome the limitations of destructive endpoint analysis.

Two-Dimensional Materials for Sensing: Graphene and Beyond

Directory of Open Access Journals (Sweden)

Seba Sara Varghese

2015-09-01

Full Text Available Two-dimensional materials have attracted great scientific attention due to their unusual and fascinating properties for use in electronics, spintronics, photovoltaics, medicine, composites, etc. Graphene, transition metal dichalcogenides such as MoS2, phosphorene, etc., which belong to the family of two-dimensional materials, have shown great promise for gas sensing applications due to their high surface-to-volume ratio, low noise and sensitivity of electronic properties to the changes in the surroundings. Two-dimensional nanostructured semiconducting metal oxide based gas sensors have also been recognized as successful gas detection devices. This review aims to provide the latest advancements in the field of gas sensors based on various two-dimensional materials with the main focus on sensor performance metrics such as sensitivity, specificity, detection limit, response time, and reversibility. Both experimental and theoretical studies on the gas sensing properties of graphene and other two-dimensional materials beyond graphene are also discussed. The article concludes with the current challenges and future prospects for two-dimensional materials in gas sensor applications.

Two-dimensional calculus

CERN Document Server

Osserman, Robert

2011-01-01

The basic component of several-variable calculus, two-dimensional calculus is vital to mastery of the broader field. This extensive treatment of the subject offers the advantage of a thorough integration of linear algebra and materials, which aids readers in the development of geometric intuition. An introductory chapter presents background information on vectors in the plane, plane curves, and functions of two variables. Subsequent chapters address differentiation, transformations, and integration. Each chapter concludes with problem sets, and answers to selected exercises appear at the end o

Quantitative volumetric Raman imaging of three dimensional cell cultures

KAUST Repository

Kallepitis, Charalambos

2017-03-22

The ability to simultaneously image multiple biomolecules in biologically relevant three-dimensional (3D) cell culture environments would contribute greatly to the understanding of complex cellular mechanisms and cell–material interactions. Here, we present a computational framework for label-free quantitative volumetric Raman imaging (qVRI). We apply qVRI to a selection of biological systems: human pluripotent stem cells with their cardiac derivatives, monocytes and monocyte-derived macrophages in conventional cell culture systems and mesenchymal stem cells inside biomimetic hydrogels that supplied a 3D cell culture environment. We demonstrate visualization and quantification of fine details in cell shape, cytoplasm, nucleus, lipid bodies and cytoskeletal structures in 3D with unprecedented biomolecular specificity for vibrational microspectroscopy.

Quantitative volumetric Raman imaging of three dimensional cell cultures

Science.gov (United States)

Kallepitis, Charalambos; Bergholt, Mads S.; Mazo, Manuel M.; Leonardo, Vincent; Skaalure, Stacey C.; Maynard, Stephanie A.; Stevens, Molly M.

2017-03-01

The ability to simultaneously image multiple biomolecules in biologically relevant three-dimensional (3D) cell culture environments would contribute greatly to the understanding of complex cellular mechanisms and cell-material interactions. Here, we present a computational framework for label-free quantitative volumetric Raman imaging (qVRI). We apply qVRI to a selection of biological systems: human pluripotent stem cells with their cardiac derivatives, monocytes and monocyte-derived macrophages in conventional cell culture systems and mesenchymal stem cells inside biomimetic hydrogels that supplied a 3D cell culture environment. We demonstrate visualization and quantification of fine details in cell shape, cytoplasm, nucleus, lipid bodies and cytoskeletal structures in 3D with unprecedented biomolecular specificity for vibrational microspectroscopy.

Phase transitions in two-dimensional systems

International Nuclear Information System (INIS)

Salinas, S.R.A.

1983-01-01

Some experiences are related using synchrotron radiation beams, to characterize solid-liquid (fusion) and commensurate solid-uncommensurate solid transitions in two-dimensional systems. Some ideas involved in the modern theories of two-dimensional fusion are shortly exposed. The systems treated consist of noble gases (Kr,Ar,Xe) adsorbed in the basal plane of graphite and thin films formed by some liquid crystal shells. (L.C.) [pt

Dynamic 3D culture promotes spontaneous embryonic stem cell differentiation in vitro.

Science.gov (United States)

Gerlach, Jörg C; Hout, Mariah; Edsbagge, Josefina; Björquist, Petter; Lübberstedt, Marc; Miki, Toshio; Stachelscheid, Harald; Schmelzer, Eva; Schatten, Gerald; Zeilinger, Katrin

2010-02-01

Spontaneous in vitro differentiation of mouse embryonic stem cells (mESC) is promoted by a dynamic, three-dimensional (3D), tissue-density perfusion technique with continuous medium perfusion and exchange in a novel four-compartment, interwoven capillary bioreactor. We compared ectodermal, endodermal, and mesodermal immunoreactive tissue structures formed by mESC at culture day 10 with mouse fetal tissue development at gestational day E9.5. The results show that the bioreactor cultures more closely resemble mouse fetal tissue development at gestational day E9.5 than control mESC cultured in Petri dishes.

The theory of critical phenomena in two-dimensional systems

International Nuclear Information System (INIS)

Olvera de la C, M.

1981-01-01

An exposition of the theory of critical phenomena in two-dimensional physical systems is presented. The first six chapters deal with the mean field theory of critical phenomena, scale invariance of the thermodynamic functions, Kadanoff's spin block construction, Wilson's renormalization group treatment of critical phenomena in configuration space, and the two-dimensional Ising model on a triangular lattice. The second part of this work is made of four chapters devoted to the application of the ideas expounded in the first part to the discussion of critical phenomena in superfluid films, two-dimensional crystals and the two-dimensional XY model of magnetic systems. Chapters seven to ten are devoted to the following subjects: analysis of long range order in one, two, and three-dimensional physical systems. Topological defects in the XY model, in superfluid films and in two-dimensional crystals. The Thouless-Kosterlitz iterated mean field theory of the dipole gas. The renormalization group treatment of the XY model, superfluid films and two-dimensional crystal. (author)

Mouse pancreas tissue slice culture facilitates long-term studies of exocrine and endocrine cell physiology in situ.

Science.gov (United States)

Marciniak, Anja; Selck, Claudia; Friedrich, Betty; Speier, Stephan

2013-01-01

Studies on pancreatic cell physiology rely on the investigation of exocrine and endocrine cells in vitro. Particularly, in the case of the exocrine tissue these studies have suffered from a reduced functional viability of acinar cells in culture. As a result not only investigations on dispersed acinar cells and isolated acini were limited in their potential, but also prolonged studies on pancreatic exocrine and endocrine cells in an intact pancreatic tissue environment were unfeasible. To overcome these limitations, we aimed to establish a pancreas tissue slice culture platform to allow long-term studies on exocrine and endocrine cells in the intact pancreatic environment. Mouse pancreas tissue slice morphology was assessed to determine optimal long-term culture settings for intact pancreatic tissue. Utilizing optimized culture conditions, cell specificity and function of exocrine acinar cells and endocrine beta cells were characterized over a culture period of 7 days. We found pancreas tissue slices cultured under optimized conditions to have intact tissue specific morphology for the entire culture period. Amylase positive intact acini were present at all time points of culture and acinar cells displayed a typical strong cell polarity. Amylase release from pancreas tissue slices decreased during culture, but maintained the characteristic bell-shaped dose-response curve to increasing caerulein concentrations and a ca. 4-fold maximal over basal release. Additionally, endocrine beta cell viability and function was well preserved until the end of the observation period. Our results show that the tissue slice culture platform provides unprecedented maintenance of pancreatic tissue specific morphology and function over a culture period for at least 4 days and in part even up to 1 week. This analytical advancement now allows mid -to long-term studies on the cell biology of pancreatic disorder pathogenesis and therapy in an intact surrounding in situ.

Mouse pancreas tissue slice culture facilitates long-term studies of exocrine and endocrine cell physiology in situ.

Directory of Open Access Journals (Sweden)

Anja Marciniak

Full Text Available Studies on pancreatic cell physiology rely on the investigation of exocrine and endocrine cells in vitro. Particularly, in the case of the exocrine tissue these studies have suffered from a reduced functional viability of acinar cells in culture. As a result not only investigations on dispersed acinar cells and isolated acini were limited in their potential, but also prolonged studies on pancreatic exocrine and endocrine cells in an intact pancreatic tissue environment were unfeasible. To overcome these limitations, we aimed to establish a pancreas tissue slice culture platform to allow long-term studies on exocrine and endocrine cells in the intact pancreatic environment. Mouse pancreas tissue slice morphology was assessed to determine optimal long-term culture settings for intact pancreatic tissue. Utilizing optimized culture conditions, cell specificity and function of exocrine acinar cells and endocrine beta cells were characterized over a culture period of 7 days. We found pancreas tissue slices cultured under optimized conditions to have intact tissue specific morphology for the entire culture period. Amylase positive intact acini were present at all time points of culture and acinar cells displayed a typical strong cell polarity. Amylase release from pancreas tissue slices decreased during culture, but maintained the characteristic bell-shaped dose-response curve to increasing caerulein concentrations and a ca. 4-fold maximal over basal release. Additionally, endocrine beta cell viability and function was well preserved until the end of the observation period. Our results show that the tissue slice culture platform provides unprecedented maintenance of pancreatic tissue specific morphology and function over a culture period for at least 4 days and in part even up to 1 week. This analytical advancement now allows mid -to long-term studies on the cell biology of pancreatic disorder pathogenesis and therapy in an intact surrounding in situ.

The Two Cultures in Psychiatry.

Science.gov (United States)

Cleghorn, R A

1965-07-10

The division between the two cultures of the literary and scientific worlds is considered, as is the division between the two cultures of humanism and somaticism. The development of psychiatric thought important to this latter dichotomy is described through the Age of Enlightenment, the Romantic Movement and the New Enlightenment. The two cultures of our present literary and scientific milieux are equated with the romanticism and somaticism of the past. The development of two cultures in psychiatry is traced, beginning with Freud's attempt to combine science and romanticism, to the present day where one finds some degree of convergence between the somatic and psychoanalytic approaches. Criteria are presented for a greater union of the two cultures in psychiatry.

Two-Dimensional Raman Correlation Analysis of Diseased Esophagus in a Rat

Science.gov (United States)

Takanezawa, Sota; Morita, Shin-ichi; Maruyama, Atsushi; Murakami, Takurou N.; Kawashima, Norimichi; Endo, Hiroyuki; Iijima, Katsunori; Asakura, Tohru; Shimosegawa, Tooru; Sato, Hidetoshi

2010-07-01

Generalized two-dimensional (2D) Raman correlation analysis effectively distinguished a benign tumor from normal tissue. Line profiling Raman spectra of a rat esophagus, including a benign tumor, were measured and the generalized 2D synchronous and asynchronous spectra were calculated. In the autocorrelation area of the amide I band of proteins in the asynchronous map, a cross-like pattern was observed. A simulation study indicated that the pattern was caused by a sharp band component in the amide I band region. We considered that the benign tumor corresponded to the sharp component.

Needle path planning and steering in a three-dimensional non-static environment using two-dimensional ultrasound images

Science.gov (United States)

Vrooijink, Gustaaf J.; Abayazid, Momen; Patil, Sachin; Alterovitz, Ron; Misra, Sarthak

2015-01-01

Needle insertion is commonly performed in minimally invasive medical procedures such as biopsy and radiation cancer treatment. During such procedures, accurate needle tip placement is critical for correct diagnosis or successful treatment. Accurate placement of the needle tip inside tissue is challenging, especially when the target moves and anatomical obstacles must be avoided. We develop a needle steering system capable of autonomously and accurately guiding a steerable needle using two-dimensional (2D) ultrasound images. The needle is steered to a moving target while avoiding moving obstacles in a three-dimensional (3D) non-static environment. Using a 2D ultrasound imaging device, our system accurately tracks the needle tip motion in 3D space in order to estimate the tip pose. The needle tip pose is used by a rapidly exploring random tree-based motion planner to compute a feasible needle path to the target. The motion planner is sufficiently fast such that replanning can be performed repeatedly in a closed-loop manner. This enables the system to correct for perturbations in needle motion, and movement in obstacle and target locations. Our needle steering experiments in a soft-tissue phantom achieves maximum targeting errors of 0.86 ± 0.35 mm (without obstacles) and 2.16 ± 0.88 mm (with a moving obstacle). PMID:26279600

Identification of Stevioside Using Tissue Culture-Derived Stevia (Stevia rebaudiana) Leaves

Science.gov (United States)

Karim, Md. Ziaul; Uesugi, Daisuke; Nakayama, Noriyuki; Hossain, M. Monzur; Ishihara, Kohji; Hamada, Hiroki

2015-01-01

Stevioside is a natural sweetener from Stevia leaf, which is 300 times sweeter than sugar. It helps to reduce blood sugar levels dramatically and thus can be of benefit to diabetic people. Tissue culture is a very potential modern technology that can be used in large-scale disease-free stevia production throughout the year. We successfully produced stevia plant through in vitro culture for identification of stevioside in this experiment. The present study describes a potential method for identification of stevioside from tissue culture-derived stevia leaf. Stevioside in the sample was identified using HPLC by measuring the retention time. The percentage of stevioside content in the leaf samples was found to be 9.6%. This identification method can be used for commercial production and industrialization of stevia through in vitro culture across the world. PMID:28008268

The Two Cultures in Psychiatry

Science.gov (United States)

Cleghorn, R. A.

1965-01-01

The division between the two cultures of the literary and scientific worlds is considered, as is the division between the two cultures of humanism and somaticism. The development of psychiatric thought important to this latter dichotomy is described through the Age of Enlightenment, the Romantic Movement and the New Enlightenment. The two cultures of our present literary and scientific milieux are equated with the romanticism and somaticism of the past. The development of two cultures in psychiatry is traced, beginning with Freud's attempt to combine science and romanticism, to the present day where one finds some degree of convergence between the somatic and psychoanalytic approaches. Criteria are presented for a greater union of the two cultures in psychiatry. PMID:20328284

Engineering Cardiac Muscle Tissue: A Maturating Field of Research.

Science.gov (United States)

Weinberger, Florian; Mannhardt, Ingra; Eschenhagen, Thomas

2017-04-28

Twenty years after the initial description of a tissue engineered construct, 3-dimensional human cardiac tissues of different kinds are now generated routinely in many laboratories. Advances in stem cell biology and engineering allow for the generation of constructs that come close to recapitulating the complex structure of heart muscle and might, therefore, be amenable to industrial (eg, drug screening) and clinical (eg, cardiac repair) applications. Whether the more physiological structure of 3-dimensional constructs provides a relevant advantage over standard 2-dimensional cell culture has yet to be shown in head-to-head-comparisons. The present article gives an overview on current strategies of cardiac tissue engineering with a focus on different hydrogel methods and discusses perspectives and challenges for necessary steps toward the real-life application of cardiac tissue engineering for disease modeling, drug development, and cardiac repair. © 2017 American Heart Association, Inc.

Specific accumulation of 18F-deoxyglucose in three-dimensional long-term cultures of human and rodent brain tissue

International Nuclear Information System (INIS)

Hocke, C.; Prante, O.; Kuwert, T.; Bluemcke, I.; Jeske, I.; Romstoeck, J.; Stefan, H.

2007-01-01

Aim: Organotypic slice cultures (OSC) of human brain specimens represent an intriguing experimental model for translational studies addressing, e.g., stem cell transplantation in neurodegenerative diseases or targeting invasion by malignant glioma ex vivo. However, long-term viability and phenomena of structural reorganization of human OSC remain to be further characterized. Here, we report the use of 18 F-deoxyglucose (FDG) for evaluating the viability of brain slice preparations obtained either from postnatal rats or human hippocampal specimens. Methods: Anatomically well preserved human hippocampi obtained from epilepsy surgery and rat hippocampus slice cultures obtained from six day old Wistar rats were dissected into horizontal slices. The slices were incubated with FDG in phosphate buffered saline up to 1 h, either with or without supplementation of glucose at a concentration of 2.5 mg/ml. Radioactivity within the medium or slice cultures was measured using a gamma-counter. In addition, distribution of radioactivity was autoradiographically visualized and quantified as counts per mm 2 . Results: In rat hippocampal slices, FDG accumulated with 1 300 000 ± 68 000 counts/mm 2 , whereas the incorporation of the radioactive label in human slices was in the order of 1 500 000 ± 370 000 counts/mm 2 . The elevation of glucose concentration within the medium led to a significant three-fold decrease of FDG accumulation in rat slices and to a 2.4-fold decrease in human specimens. Conclusions: FDG accumulated in organotypic brain cultures of human or rodent origin. FDG is thus suited to investigate the viability of OSC. Furthermore, these preparations open new ways to study the factors governing cerebral FDG uptake in brain tissue ex vivo. (orig.)

Two- and three-dimensional CT analysis of ankle fractures

International Nuclear Information System (INIS)

Magid, D.; Fishman, E.K.; Ney, D.R.; Kuhlman, J.E.

1988-01-01

CT with coronal and sagittal reformatting (two-dimensional CT) and animated volumetric image rendering (three-dimensional CT) was used to assess ankle fractures. Partial volume limits transaxial CT in assessments of horizontally oriented structures. Two-dimensional CT, being orthogonal to the plafond, superior mortise, talar dome, and tibial epiphysis, often provides the most clinically useful images. Two-dimensional CT is most useful in characterizing potentially confusing fractures, such as Tillaux (anterior tubercle), triplane, osteochondral talar dome, or nondisplaced talar neck fractures, and it is the best study to confirm intraarticular fragments. Two-and three-dimensional CT best indicate the percentage of articular surface involvement and best demonstrate postoperative results or complications (hardware migration, residual step-off, delayed union, DJD, AVN, etc). Animated three-dimensional images are the preferred means of integrating the two-dimensional findings for surgical planning, as these images more closely simulate the clinical problem

On two-dimensionalization of three-dimensional turbulence in shell models

DEFF Research Database (Denmark)

Chakraborty, Sagar; Jensen, Mogens Høgh; Sarkar, A.

2010-01-01

Applying a modified version of the Gledzer-Ohkitani-Yamada (GOY) shell model, the signatures of so-called two-dimensionalization effect of three-dimensional incompressible, homogeneous, isotropic fully developed unforced turbulence have been studied and reproduced. Within the framework of shell m......-similar PDFs for longitudinal velocity differences are also presented for the rotating 3D turbulence case....

Two-dimensional turbulent convection

Science.gov (United States)

Mazzino, Andrea

2017-11-01

We present an overview of the most relevant, and sometimes contrasting, theoretical approaches to Rayleigh-Taylor and mean-gradient-forced Rayleigh-Bénard two-dimensional turbulence together with numerical and experimental evidences for their support. The main aim of this overview is to emphasize that, despite the different character of these two systems, especially in relation to their steadiness/unsteadiness, turbulent fluctuations are well described by the same scaling relationships originated from the Bolgiano balance. The latter states that inertial terms and buoyancy terms balance at small scales giving rise to an inverse kinetic energy cascade. The main difference with respect to the inverse energy cascade in hydrodynamic turbulence [R. H. Kraichnan, "Inertial ranges in two-dimensional turbulence," Phys. Fluids 10, 1417 (1967)] is that the rate of cascade of kinetic energy here is not constant along the inertial range of scales. Thanks to the absence of physical boundaries, the two systems here investigated turned out to be a natural physical realization of the Kraichnan scaling regime hitherto associated with the elusive "ultimate state of thermal convection" [R. H. Kraichnan, "Turbulent thermal convection at arbitrary Prandtl number," Phys. Fluids 5, 1374-1389 (1962)].

Rotary culture enhances pre-osteoblast aggregation and mineralization.

Science.gov (United States)

Facer, S R; Zaharias, R S; Andracki, M E; Lafoon, J; Hunter, S K; Schneider, G B

2005-06-01

Three-dimensional environments have been shown to enhance cell aggregation and osteoblast differentiation. Thus, we hypothesized that three-dimensional (3D) growth environments would enhance the mineralization rate of human embryonic palatal mesenchymal (HEPM) pre-osteoblasts. The objective of this study was to investigate the potential use of rotary cell culture systems (RCCS) as a means to enhance the osteogenic potential of pre-osteoblast cells. HEPM cells were cultured in a RCCS to create 3D enviroments. Tissue culture plastic (2D) cultures served as our control. 3D environments promoted three-dimensional aggregate formations. Increased calcium and phosphorus deposition was significantly enhanced three- to 18-fold (P < 0.001) in 3D cultures as compared with 2D environments. 3D cultures mineralized in 1 wk as compared with the 2D cultures, which took 4 wks, a decrease in time of nearly 75%. In conclusion, our studies demonstrated that 3D environments enhanced osteoblast cell aggregation and mineralization.

Banana Musa tissue culture plants enhanced by endophytic fungi

African Journals Online (AJOL)

Mo

Merging biotechnology with biological control: Banana Musa tissue culture plants enhanced by endophytic .... While working in the laminar flow cabinet, sterile filter papers were placed in ..... University of Bonn, Bonn, Germany. Niere, B., 2001.

Research progress in plant mutation by combining ion beam irradiations and tissue culture

International Nuclear Information System (INIS)

Zhou Linbin; Li Wenjian; Qu Ying; Li Ping

2007-01-01

About a new mutation breeding method which combines plant tissue culture technique with heavy ion beam irradiations were discussed in this paper with the principles, operation steps, molecular mechanisms, etc. The mutation method developed a few advantages coming from plant tissue culture, which can produce offspring by asexual ways. Meanwhile, using this method, the study of biological effects of high energy particles with different linear energy transfer values on plant tissues or cells can be explored and optimized in theory or practice. (authors)

HYPOLIPIDEMIC EFFECT OF ARGLABIN IN HEPATOMA TISSUE CULTURE

Directory of Open Access Journals (Sweden)

A. V. Ratkin

2015-01-01

Full Text Available Objective. Investigation of hypolipidemic effect of sesquiterpene γ-lactone Arglabin in hepatoma tissue culture (HTC.Materials and methods. In this study we’ve evaluated the effect of sesquiterpene γ-lactone Arglabin and gemfibrozil (reference drug on the lipid content in the hepatoma tissue culture (HTC which were incubated with a fat emulsion “Lipofundin” by fluorescent method with vital dye Nile Red. The cell viability was investigated using the MTT-test and staining by Trypan blue.Results. Cultivation of cell cultures of rat’s hepatoma cell line HTC with Arglabin and gemfibrozil in concentrations from 10 to 50 μmol and from 0.25 to 0.5 mmol, respectively, had no cytotoxic effect. HTC cell viability did not change compared with the corresponding rate in the control culture. Experimental hyperlipidemia in hepatoma culture was induced by the addition in the incubation medium of fat emulsion “Lipofundin” in a final concentration of 0.05 %. The fluorescence intensity of Nile Red in the cells was increased 4-fold (p < 0.05, which indicates a significant accumulation of lipids in the cytosol of cells. In these steady-state Arglabin and gemfibrozil at concentrations 75–100 μM and 0.25–1.0 mM, respectively, reduced the content of lipid in cells. Conclusion. In the model of hyperlipidemia induced by lipofundin, sesquiterpene γ-lactone Arglabin prevents the accumulation of lipids in the HTC cell line, as evidenced by a decrease in Nile Red fluorescence. However hypolipidemic effect of Arglabin is associated with cytotoxic effects, which is typical for anticancer drugs.

Multi-perspective views of students’ difficulties with one-dimensional vector and two-dimensional vector

Science.gov (United States)

Fauzi, Ahmad; Ratna Kawuri, Kunthi; Pratiwi, Retno

2017-01-01

Researchers of students’ conceptual change usually collects data from written tests and interviews. Moreover, reports of conceptual change often simply refer to changes in concepts, such as on a test, without any identification of the learning processes that have taken place. Research has shown that students have difficulties with vectors in university introductory physics courses and high school physics courses. In this study, we intended to explore students’ understanding of one-dimensional and two-dimensional vector in multi perspective views. In this research, we explore students’ understanding through test perspective and interviews perspective. Our research study adopted the mixed-methodology design. The participants of this research were sixty students of third semester of physics education department. The data of this research were collected by testand interviews. In this study, we divided the students’ understanding of one-dimensional vector and two-dimensional vector in two categories, namely vector skills of the addition of one-dimensionaland two-dimensional vector and the relation between vector skills and conceptual understanding. From the investigation, only 44% of students provided correct answer for vector skills of the addition of one-dimensional and two-dimensional vector and only 27% students provided correct answer for the relation between vector skills and conceptual understanding.

Two-Photon Excitation Microscopy for the Study of Living Cells and Tissues

Science.gov (United States)

Benninger, Richard K.P.; Piston, David W.

2013-01-01

Two-photon excitation microscopy is an alternative to confocal microscopy that provides advantages for three-dimensional and deep tissue imaging. This unit will describe the basic physical principles behind two-photon excitation and discuss the advantages and limitations of its use in laser-scanning microscopy. The principal advantages of two-photon microscopy are reduced phototoxicity, increased imaging depth, and the ability to initiate highly localized photochemistry in thick samples. Practical considerations for the application of two-photon microscopy will then be discussed, including recent technological advances. This unit will conclude with some recent applications of two-photon microscopy that highlight the key advantages over confocal microscopy and the types of experiments which would benefit most from its application. PMID:23728746

Optimizing separations in online comprehensive two-dimensional liquid chromatography.

Science.gov (United States)

Pirok, Bob W J; Gargano, Andrea F G; Schoenmakers, Peter J

2018-01-01

Online comprehensive two-dimensional liquid chromatography has become an attractive option for the analysis of complex nonvolatile samples found in various fields (e.g. environmental studies, food, life, and polymer sciences). Two-dimensional liquid chromatography complements the highly popular hyphenated systems that combine liquid chromatography with mass spectrometry. Two-dimensional liquid chromatography is also applied to the analysis of samples that are not compatible with mass spectrometry (e.g. high-molecular-weight polymers), providing important information on the distribution of the sample components along chemical dimensions (molecular weight, charge, lipophilicity, stereochemistry, etc.). Also, in comparison with conventional one-dimensional liquid chromatography, two-dimensional liquid chromatography provides a greater separation power (peak capacity). Because of the additional selectivity and higher peak capacity, the combination of two-dimensional liquid chromatography with mass spectrometry allows for simpler mixtures of compounds to be introduced in the ion source at any given time, improving quantitative analysis by reducing matrix effects. In this review, we summarize the rationale and principles of two-dimensional liquid chromatography experiments, describe advantages and disadvantages of combining different selectivities and discuss strategies to improve the quality of two-dimensional liquid chromatography separations. © 2017 The Authors. Journal of Separation Science published by WILEY-VCH Verlag GmbH & Co. KGaA.

Human colon tissue in organ culture: calcium and multi-mineral-induced mucosal differentiation.

Science.gov (United States)

Dame, Michael K; Veerapaneni, Indiradevi; Bhagavathula, Narasimharao; Naik, Madhav; Varani, James

2011-01-01

We have recently shown that a multi-mineral extract from the marine red algae, Lithothamnion calcareum, suppresses colon polyp formation and inflammation in mice. In the present study, we used intact human colon tissue in organ culture to compare responses initiated by Ca(2+) supplementation versus the multi-mineral extract. Normal human colon tissue was treated for 2 d in culture with various concentrations of calcium or the mineral-rich extract. The tissue was then prepared for histology/immunohistochemistry, and the culture supernatants were assayed for levels of type I procollagen and type I collagen. At higher Ca(2+) concentrations or with the mineral-rich extract, proliferation of epithelial cells at the base and walls of the mucosal crypts was suppressed, as visualized by reduced Ki67 staining. E-cadherin, a marker of differentiation, was more strongly expressed at the upper third of the crypt and at the luminal surface. Treatment with Ca(2+) or with the multi-mineral extract influenced collagen turnover, with decreased procollagen and increased type I collagen. These data suggest that calcium or mineral-rich extract has the capacity to (1) promote differentiation in human colon tissue in organ culture and (2) modulate stromal function as assessed by increased levels of type I collagen. Taken together, these data suggest that human colon tissue in organ culture (supporting in vivo finding in mice) will provide a valuable model for the preclinical assessment of agents that regulate growth and differentiation in the colonic mucosa.

Two-dimensional liquid chromatography

DEFF Research Database (Denmark)

Græsbøll, Rune

-dimensional separation space. Optimization of gradients in online RP×RP is more difficult than in normal HPLC as a result of the increased number of parameters and their influence on each other. Modeling the coverage of the compounds across the two-dimensional chromatogram as a result of a change in gradients could...... be used for optimization purposes, and reduce the time spend on optimization. In this thesis (chapter 6), and manuscript B, a measure of the coverage of the compounds in the twodimensional separation space is defined. It is then shown that this measure can be modeled for changes in the gradient in both...

Two-dimensional simulation of sintering process

International Nuclear Information System (INIS)

Vasconcelos, Vanderley de; Pinto, Lucio Carlos Martins; Vasconcelos, Wander L.

1996-01-01

The results of two-dimensional simulations are directly applied to systems in which one of the dimensions is much smaller than the others, and to sections of three dimensional models. Moreover, these simulations are the first step of the analysis of more complex three-dimensional systems. In this work, two basic features of the sintering process are studied: the types of particle size distributions related to the powder production processes and the evolution of geometric parameters of the resultant microstructures during the solid-state sintering. Random packing of equal spheres is considered in the sintering simulation. The packing algorithm does not take into account the interactive forces between the particles. The used sintering algorithm causes the densification of the particle set. (author)

Influence of flow conditions and matrix coatings on growth and differentiation of three-dimensionally cultured rat hepatocytes.

Science.gov (United States)

Fiegel, Henning C; Havers, Joerg; Kneser, Ulrich; Smith, Molly K; Moeller, Tim; Kluth, Dietrich; Mooney, David J; Rogiers, Xavier; Kaufmann, Peter M

2004-01-01

Maintenance of liver-specific function of hepatocytes in culture is still difficult. Improved culture conditions may enhance the cell growth and function of cultured cells. We investigated the effect of three-dimensional culture under flow conditions, and the influence of surface modifications in hepatocyte cultures. Hepatocytes were harvested from Lewis rats. Cells were cultured on three-dimensional polymeric poly-lactic-co-glycolic acid (PLGA) matrices in static culture, or in a pulsatile flow-bioreactor system. Different surface modifications of matrices were investigated: coating with collagen I, collagen IV, laminin, or fibronectin; or uncoated matrix. Hepatocyte numbers, DNA content, and albumin secretion rate were assessed over the observation period. Culture under flow condition significantly enhanced cell numbers. An additional improvement of this effect was observed, when matrix coating was used. Cellular function also showed a significant increase (4- to 5-fold) under flow conditions when compared with static culture. Our data showed that culture under flow conditions improves cell number, and strongly enhances cellular function. Matrix modification by coating with extracellular matrix showed overall an additive stimulatory effect. Our conclusion is that combining three-dimensional culture under flow conditions and using matrix modification significantly improves culture conditions and is therefore attractive for the development of successful culture systems for hepatocytes.

Concordance and reproducibility between M-mode, tissue Doppler imaging, and two-dimensional strain imaging in the assessment of mitral annular displacement and velocity in patients with various heart conditions

DEFF Research Database (Denmark)

de Knegt, Martina Chantal; Biering-Sorensen, Tor; Sogaard, Peter

2014-01-01

AIMS: Mitral annular (MA) displacement reflects longitudinal left ventricular (LV) deformation and systolic velocity measurements reflect the rate of contraction; both are valuable in the diagnosis and prognosis of cardiac disease. The aim of this study was to test the agreement and reproducibility...... between motion mode (M-mode), colour tissue Doppler imaging (TDI), and two-dimensional strain imaging (2DSI) when measuring MA displacement and systolic velocity. METHODS AND RESULTS: Using GE Healthcare Vivid 7 and E9 and Echopac BT11 software, MA displacement and velocity measurements by 2DSI, TDI...

Plasmid-dependent attachment of Agrobacterium tumefaciens to plant tissue culture cells.

Science.gov (United States)

Matthysse, A G; Wyman, P M; Holmes, K V

1978-11-01

Kinetic, microscopic, and biochemical studies show that virulent Ti (tumor inducing)-plasmid-containing strains of Agrobacterium attach to normal tobacco and carrot tissue culture cells. Kinetic studies showed that virulent strains of A. tumefaciens attach to the plant tissue culture cells in increasing numbers during the first 1 to 2 h of incubation of the bacteria with the plant cells. Five Ti-plasmid-containing virulent Agrobacterium strains showed greater attachment to tobacco cells than did five avirulent strains. Light and scanning electron microscopic observations confirmed that virulent strains showed little attachment. Bacterial attachment was blocked by prior incubation of the plant cells with lipopolysaccharide extracted from A. tumefaciens, but not from A. radiobacter, suggesting that bacterial lipopolysaccharide is one of the components involved in the attachment process. At least one other bacterial product may be required for attachment in tissue culture because the virulent A. tumefaciens NT1, which lacks the Ti plasmid, does not itself attach to tobacco cells, but its lipopolysaccharide does inhibit the attachment of virulent strains.

Chaotic dynamics in two-dimensional noninvertible maps

CERN Document Server

Mira, Christian; Cathala, Jean-Claude; Gardini, Laura

1996-01-01

This book is essentially devoted to complex properties (Phase plane structure and bifurcations) of two-dimensional noninvertible maps, i.e. maps having either a non-unique inverse, or no real inverse, according to the plane point. They constitute models of sets of discrete dynamical systems encountered in Engineering (Control, Signal Processing, Electronics), Physics, Economics, Life Sciences. Compared to the studies made in the one-dimensional case, the two-dimensional situation remained a long time in an underdeveloped state. It is only since these last years that the interest for this resea

Application of a method for comparing one-dimensional and two-dimensional models of a ground-water flow system

International Nuclear Information System (INIS)

Naymik, T.G.

1978-01-01

To evaluate the inability of a one-dimensional ground-water model to interact continuously with surrounding hydraulic head gradients, simulations using one-dimensional and two-dimensional ground-water flow models were compared. This approach used two types of models: flow-conserving one-and-two dimensional models, and one-dimensional and two-dimensional models designed to yield two-dimensional solutions. The hydraulic conductivities of controlling features were varied and model comparison was based on the travel times of marker particles. The solutions within each of the two model types compare reasonably well, but a three-dimensional solution is required to quantify the comparison

A Bioengineered Three-Dimensional Cell Culture Platform Integrated with Microfluidics To Address Antimicrobial Resistance in Tuberculosis

Directory of Open Access Journals (Sweden)

Magdalena K. Bielecka

2017-02-01

Full Text Available Antimicrobial resistance presents one of the most significant threats to human health, with the emergence of totally drug-resistant organisms. We have combined bioengineering, genetically modified bacteria, longitudinal readouts, and fluidics to develop a transformative platform to address the drug development bottleneck, utilizing Mycobacterium tuberculosis as the model organism. We generated microspheres incorporating virulent reporter bacilli, primary human cells, and an extracellular matrix by using bioelectrospray methodology. Granulomas form within the three-dimensional matrix, and mycobacterial stress genes are upregulated. Pyrazinamide, a vital first-line antibiotic for treating human tuberculosis, kills M. tuberculosis in a three-dimensional culture but not in a standard two-dimensional culture or Middlebrook 7H9 broth, demonstrating that antibiotic sensitivity within microspheres reflects conditions in patients. We then performed pharmacokinetic modeling by combining the microsphere system with a microfluidic plate and demonstrated that we can model the effect of dynamic antibiotic concentrations on mycobacterial killing. The microsphere system is highly tractable, permitting variation of cell content, the extracellular matrix, sphere size, the infectious dose, and the surrounding medium with the potential to address a wide array of human infections and the threat of antimicrobial resistance.

A method for establishing human primary gastric epithelial cell culture from fresh surgical gastric tissues.

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Aziz, Faisal; Yang, Xuesong; Wen, Qingping; Yan, Qiu

2015-08-01

At present, biopsy specimens, cancer cell lines and tissues obtained by gastric surgery are used in the study and analysis of gastric cancer, including the molecular mechanisms and proteomics. However, fibroblasts and other tissue components may interfere with these techniques. Therefore, the present study aimed to develop a procedure for the isolation of viable human gastric epithelial cells from gastric surgical tissues. A method was developed to culture human gastric epithelial cells using fresh, surgically excised tissues and was evaluated using immunocytochemistry, periodic acid-Schiff (PAS) staining and cell viability assays. Low cell growth was observed surrounding the gastric tissue on the seventh day of tissue explant culture. Cell growth subsequently increased, and at 12 days post-explant a high number of pure epithelial cells were detected. The gastric cancer cells exhibited rapid growth with a doubling time of 13-52 h, as compared to normal cells, which had a doubling time of 20-53 h. Immunocytochemical analyses of primary gastric cells revealed positive staining for cytokeratin 18 and 19, which indicated that the culture was comprised of pure epithelial cells and contained no fibroblasts. Furthermore, PAS staining demonstrated that the cultured gastric cells produced neutral mucin. Granulin and carbohydrate antigen 724 staining confirmed the purity of gastric cancer and normal cells in culture. This method of cell culture indicated that the gastric cells in primary culture consisted of mucin-secreting gastric epithelial cells, which may be useful for the study of gastric infection with Helicobacter pylori and gastric cancer.

Toxicity and oxidative stress of canine mesenchymal stromal cells from adipose tissue in different culture passages

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Arícia Gomes Sprada

2015-12-01

Full Text Available Abstract: Stem cells in regenerative therapy have received attention from researchers in recent decades. The culture of these cells allows studies about their behavior and metabolism. Thus, cell culture is the basis for cell therapy and tissue engineering researches. A major concern regarding the use of cultivated stem cell in human or veterinary clinical routine is the risk of carcinogenesis. Cellular activities require a balanced redox state. However, when there is an imbalance in this state, oxidative stress occurs. Oxidative stress contributes to cytotoxicity, which may result in cell death or genomic alterations, favoring the development of cancer cells. The aim of this study was to determine whether there are differences in the behavior of cultured mesenchymal stem cells from canine adipose tissue according to its site of collection (omentum and subcutaneous evaluating the rate of proliferation, viability, level of oxidative stress and cytotoxicity over six passages. For this experiment, two samples of adipose tissue from subcutaneous and omentum where taken from a female dog corpse, 13 years old, Pitbull. The results showed greater levels of oxidative stress in the first and last passages of both groups, favoring cytotoxicity and cell death.

Two-dimensional analytic weighting functions for limb scattering

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Zawada, D. J.; Bourassa, A. E.; Degenstein, D. A.

2017-10-01

Through the inversion of limb scatter measurements it is possible to obtain vertical profiles of trace species in the atmosphere. Many of these inversion methods require what is often referred to as weighting functions, or derivatives of the radiance with respect to concentrations of trace species in the atmosphere. Several radiative transfer models have implemented analytic methods to calculate weighting functions, alleviating the computational burden of traditional numerical perturbation methods. Here we describe the implementation of analytic two-dimensional weighting functions, where derivatives are calculated relative to atmospheric constituents in a two-dimensional grid of altitude and angle along the line of sight direction, in the SASKTRAN-HR radiative transfer model. Two-dimensional weighting functions are required for two-dimensional inversions of limb scatter measurements. Examples are presented where the analytic two-dimensional weighting functions are calculated with an underlying one-dimensional atmosphere. It is shown that the analytic weighting functions are more accurate than ones calculated with a single scatter approximation, and are orders of magnitude faster than a typical perturbation method. Evidence is presented that weighting functions for stratospheric aerosols calculated under a single scatter approximation may not be suitable for use in retrieval algorithms under solar backscatter conditions.

Fibrin promotes proliferation and matrix production of intervertebral disc cells cultured in three-dimensional poly(lactic-co-glycolic acid) scaffold.

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Sha'ban, Munirah; Yoon, Sun Jung; Ko, Youn Kyung; Ha, Hyun Jung; Kim, Soon Hee; So, Jung Won; Idrus, Ruszymah Bt Hj; Khang, Gilson

2008-01-01

Previously, we have proven that fibrin and poly(lactic-co-glycolic acid) (PLGA) scaffolds facilitate cell proliferation, matrix production and early chondrogenesis of rabbit articular chondrocytes in in vitro and in vivo experiments. In this study, we evaluated the potential of fibrin/PLGA scaffold for intervertebral disc (IVD) tissue engineering using annulus fibrosus (AF) and nucleus pulposus (NP) cells in relation to potential clinical application. PLGA scaffolds were soaked in cells-fibrin suspension and polymerized by dropping thrombin-sodium chloride (CaCl(2)) solution. A PLGA-cell complex without fibrin was used as control. Higher cellular proliferation activity was observed in fibrin/PLGA-seeded AF and NP cells at each time point of 3, 7, 14 and 7 days using the MTT assay. After 3 weeks in vitro incubation, fibrin/PLGA exhibited a firmer gross morphology than PLGA groups. A significant cartilaginous tissue formation was observed in fibrin/PLGA, as proven by the development of cells cluster of various sizes and three-dimensional (3D) cartilaginous histoarchitecture and the presence of proteoglycan-rich matrix and glycosaminoglycan (GAG). The sGAG production measured by 1,9-dimethylmethylene blue (DMMB) assay revealed greater sGAG production in fibrin/PLGA than PLGA group. Immunohistochemical analyses showed expressions of collagen type II, aggrecan core protein and collagen type I genes throughout in vitro culture in both fibrin/PLGA and PLGA. In conclusion, fibrin promotes cell proliferation, stable in vitro tissue morphology, superior cartilaginous tissue formation and sGAG production of AF and NP cells cultured in PLGA scaffold. The 3D porous PLGA scaffold-cell complexes using fibrin can provide a vehicle for delivery of cells to regenerate tissue-engineered IVD tissue.

Nanoelectronics-biology frontier: From nanoscopic probes for action potential recording in live cells to three-dimensional cyborg tissues.

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Duan, Xiaojie; Fu, Tian-Ming; Liu, Jia; Lieber, Charles M

2013-08-01

Semiconductor nanowires configured as the active channels of field-effect transistors (FETs) have been used as detectors for high-resolution electrical recording from single live cells, cell networks, tissues and organs. Extracellular measurements with substrate supported silicon nanowire (SiNW) FETs, which have projected active areas orders of magnitude smaller than conventional microfabricated multielectrode arrays (MEAs) and planar FETs, recorded action potential and field potential signals with high signal-to-noise ratio and temporal resolution from cultured neurons, cultured cardiomyocytes, acute brain slices and whole animal hearts. Measurements made with modulation-doped nanoscale active channel SiNW FETs demonstrate that signals recorded from cardiomyocytes are highly localized and have improved time resolution compared to larger planar detectors. In addition, several novel three-dimensional (3D) transistor probes, which were realized using advanced nanowire synthesis methods, have been implemented for intracellular recording. These novel probes include (i) flexible 3D kinked nanowire FETs, (ii) branched intracellular nanotube SiNW FETs, and (iii) active silicon nanotube FETs. Following phospholipid modification of the probes to mimic the cell membrane, the kinked nanowire, branched intracellular nanotube and active silicon nanotube FET probes recorded full-amplitude intracellular action potentials from spontaneously firing cardiomyocytes. Moreover, these probes demonstrated the capability of reversible, stable, and long-term intracellular recording, thus indicating the minimal invasiveness of the new nanoscale structures and suggesting biomimetic internalization via the phospholipid modification. Simultaneous, multi-site intracellular recording from both single cells and cell networks were also readily achieved by interfacing independently addressable nanoprobe devices with cells. Finally, electronic and biological systems have been seamlessly merged in 3D

Identification of Stevioside Using Tissue Culture-Derived Stevia () Leaves

OpenAIRE

Ziaul Karim Md.; Daisuke Uesugi; Noriyuki Nakayama; M. Monzur Hossain; Kohji Ishihara; Hiroki Hamada

2015-01-01

Stevioside is a natural sweetener from Stevia leaf, which is 300 times sweeter than sugar. It helps to reduce blood sugar levels dramatically and thus can be of benefit to diabetic people. Tissue culture is a very potential modern technology that can be used in large-scale disease-free stevia production throughout the year. We successfully produced stevia plant through in vitro culture for identification of stevioside in this experiment. The present study describes a potential method for iden...

Three-Dimensionally Engineered Normal Human Broncho-epithelial Tissue-Like Assemblies: Target Tissues for Human Respiratory Viral Infections

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Goodwin, T. J.; McCarthy, M.; Lin, Y-H

2006-01-01

In vitro three-dimensional (3D) human broncho-epithelial (HBE) tissue-like assemblies (3D HBE TLAs) from this point forward referred to as TLAs were engineered in Rotating Wall Vessel (RWV) technology to mimic the characteristics of in vivo tissues thus providing a tool to study human respiratory viruses and host cell interactions. The TLAs were bioengineered onto collagen-coated cyclodextran microcarriers using primary human mesenchymal bronchial-tracheal cells (HBTC) as the foundation matrix and an adult human bronchial epithelial immortalized cell line (BEAS-2B) as the overlying component. The resulting TLAs share significant characteristics with in vivo human respiratory epithelium including polarization, tight junctions, desmosomes, and microvilli. The presence of tissue-like differentiation markers including villin, keratins, and specific lung epithelium markers, as well as the production of tissue mucin, further confirm these TLAs differentiated into tissues functionally similar to in vivo tissues. Increasing virus titers for human respiratory syncytial virus (wtRSVA2) and parainfluenza virus type 3 (wtPIV3 JS) and the detection of membrane bound glycoproteins over time confirm productive infections with both viruses. Therefore, TLAs mimic aspects of the human respiratory epithelium and provide a unique capability to study the interactions of respiratory viruses and their primary target tissue independent of the host's immune system.

The use of tissue culture techniques to detect irradiated vegetables

International Nuclear Information System (INIS)

Al-Safadi, B.; Sharabi, N.E.; Nabulsi, I

2001-01-01

the ability of two tissue culture methods, callus and vegetable growth induction, to detect irradiated vegetables was evaluated. Potato tubers, carrot roots, garlic cloves and onion bulbs were subjected to various gamma radiation doses (0, 25, 100, 150, 250, 500, 750, and 1000 Gy). Irradiated vegetables were cultured in vitro and in vivo (pots). Gamma irradiation significantly reduced callus-forming ability especially in carrot and potato where no callus was observed in doses higher than 50 Gy. Length of shoots and roots growing from irradiated garlic and onion explants was considerably reduced starting from the 25 Gy dose. No roots were formed on garlic explants at any irradiation dose. Garlic leaves growing from irradiated explants were spotted with purple to brown spots. The intensity of these spots increased as gamma ray dosage increased. In the pot experiment, potato plant appeared in the control only. On the contrary, a complete sprouting of garlic and onion was seen in all irradiation treatments. It was not possible to distinguish between the various irradiation treatments and the control 3 days after planting in pots. The two in vitro techniques, tested in our study, may effectively be used to detect irradiated vegetables and estimate the range of doses used. The callus formation method is more useful for potato and carrot, since regeneration of shoots in vitro from these two plants takes along time, making this method unpractical. The other technique is very useful in the case of onion and garlic since it is rapid. The two techniques can be used with most of the vegetables that can be cultured in vitro. (Author)

Depth-enhanced three-dimensional-two-dimensional convertible display based on modified integral imaging.

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Park, Jae-Hyeung; Kim, Hak-Rin; Kim, Yunhee; Kim, Joohwan; Hong, Jisoo; Lee, Sin-Doo; Lee, Byoungho

2004-12-01

A depth-enhanced three-dimensional-two-dimensional convertible display that uses a polymer-dispersed liquid crystal based on the principle of integral imaging is proposed. In the proposed method, a lens array is located behind a transmission-type display panel to form an array of point-light sources, and a polymer-dispersed liquid crystal is electrically controlled to pass or to scatter light coming from these point-light sources. Therefore, three-dimensional-two-dimensional conversion is accomplished electrically without any mechanical movement. Moreover, the nonimaging structure of the proposed method increases the expressible depth range considerably. We explain the method of operation and present experimental results.

A multifunctional 3D co-culture system for studies of mammary tissue morphogenesis and stem cell biology.

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Jonathan J Campbell

Full Text Available Studies on the stem cell niche and the efficacy of cancer therapeutics require complex multicellular structures and interactions between different cell types and extracellular matrix (ECM in three dimensional (3D space. We have engineered a 3D in vitro model of mammary gland that encompasses a defined, porous collagen/hyaluronic acid (HA scaffold forming a physiologically relevant foundation for epithelial and adipocyte co-culture. Polarized ductal and acinar structures form within this scaffold recapitulating normal tissue morphology in the absence of reconstituted basement membrane (rBM hydrogel. Furthermore, organoid developmental outcome can be controlled by the ratio of collagen to HA, with a higher HA concentration favouring acinar morphological development. Importantly, this culture system recapitulates the stem cell niche as primary mammary stem cells form complex organoids, emphasising the utility of this approach for developmental and tumorigenic studies using genetically altered animals or human biopsy material, and for screening cancer therapeutics for personalised medicine.

Functional inks and printing of two-dimensional materials.

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Hu, Guohua; Kang, Joohoon; Ng, Leonard W T; Zhu, Xiaoxi; Howe, Richard C T; Jones, Christopher G; Hersam, Mark C; Hasan, Tawfique

2018-05-08

Graphene and related two-dimensional materials provide an ideal platform for next generation disruptive technologies and applications. Exploiting these solution-processed two-dimensional materials in printing can accelerate this development by allowing additive patterning on both rigid and conformable substrates for flexible device design and large-scale, high-speed, cost-effective manufacturing. In this review, we summarise the current progress on ink formulation of two-dimensional materials and the printable applications enabled by them. We also present our perspectives on their research and technological future prospects.

K-FIX: a computer program for transient, two-dimensional, two-fluid flow. THREED: an extension of the K-FIX code for three-dimensional calculations

International Nuclear Information System (INIS)

Rivard, W.C.; Torrey, M.D.

1978-10-01

The transient, two-dimensional, two-fluid code K-FIX has been extended to perform three-dimensional calculations. This capability is achieved by adding five modification sets of FORTRAN statements to the basic two-dimensional code. The modifications are listed and described, and a complete listing of the three-dimensional code is provided. Results of an example problem are provided for verification

Usefulness of fibroblast culture for testing of cattle tissues polluted with heavy metals

International Nuclear Information System (INIS)

Weglarz, L.; Drozdz, M.Wa.; Wardas, M.; Kula, B.; Pawlaczyk-Szpilowa, M.

1990-01-01

Cattle tissues (liver, kidney, brain, and lung) that had been polluted with heavy metals were tested for their ability to alter fibroblast culture growth, cellular protein and DNA content, and fibroblast DNA synthesis. At 72 hr of incubation a significant increase in cellular DNA and [14C]thymidine incorporation was noted in the primary cultures as well as in the subcultures compared to controls. Fibroblast cultures also displayed growth inhibition and reduction in protein content. The measurement of basic biochemical parameters of the fibroblast culture may represent a sensitive means of assessing rapidly the activity of heavy metals deposited in the tissues of cattle as a result of their grazing on polluted soil

Preparation and characterization of a three-dimensional printed scaffold based on a functionalized polyester for bone tissue engineering applications.

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Seyednejad, Hajar; Gawlitta, Debby; Dhert, Wouter J A; van Nostrum, Cornelus F; Vermonden, Tina; Hennink, Wim E

2011-05-01

At present there is a strong need for suitable scaffolds that meet the requirements for bone tissue engineering applications. The objective of this study was to investigate the suitability of porous scaffolds based on a hydroxyl functionalized polymer, poly(hydroxymethylglycolide-co-ε-caprolactone) (pHMGCL), for tissue engineering. In a recent study this polymer was shown to be a promising material for bone regeneration. The scaffolds consisting of pHMGCL or poly(ε-caprolactone) (PCL) were produced by means of a rapid prototyping technique (three-dimensional plotting) and were shown to have a high porosity and an interconnected pore structure. The thermal and mechanical properties of both scaffolds were investigated and human mesenchymal stem cells were seeded onto the scaffolds to evaluate the cell attachment properties, as well as cell viability and differentiation. It was shown that the cells filled the pores of the pHMGCL scaffold within 7 days and displayed increased metabolic activity when compared with cells cultured in PCL scaffolds. Importantly, pHMGCL scaffolds supported osteogenic differentiation. Therefore, scaffolds based on pHMGCL are promising templates for bone tissue engineering applications. Copyright © 2011 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Screenhouse and field persistence of nonpathogenic endophytic Fusarium oxysporum in Musa tissue culture plants.

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Paparu, Pamela; Dubois, Thomas; Gold, Clifford S; Niere, Björn; Adipala, Ekwamu; Coyne, Daniel

2008-04-01

Two major biotic constraints to highland cooking banana (Musa spp., genome group AAA-EA) production in Uganda are the banana weevil Cosmopolites sordidus and the burrowing nematode Radopholus similis. Endophytic Fusarium oxysporum strains inoculated into tissue culture banana plantlets have shown control of the banana weevil and the nematode. We conducted screenhouse and field experiments to investigate persistence in the roots and rhizome of two endophytic Fusarium oxysporum strains, V2w2 and III4w1, inoculated into tissue-culture banana plantlets of highland cooking banana cultivars Kibuzi and Nabusa. Re-isolation of F. oxysporum showed that endophyte colonization decreased faster from the rhizomes than from the roots of inoculated plants, both in the screenhouse and in the field. Whereas rhizome colonization by F. oxysporum decreased in the screenhouse (4-16 weeks after inoculation), root colonization did not. However, in the field (17-33 weeks after inoculation), a decrease was observed in both rhizome and root colonization. The results show a better persistence in the roots than rhizomes of endophytic F. oxysporum strains V2w2 and III4w1.

Two-dimensional critical phenomena

International Nuclear Information System (INIS)

Saleur, H.

1987-09-01

Two dimensional critical systems are studied using transformation to free fields and conformal invariance methods. The relations between the two approaches are also studied. The analytical results obtained generally depend on universality hypotheses or on renormalization group trajectories which are not established rigorously, so numerical verifications, mainly using the transfer matrix approach, are presented. The exact determination of critical exponents; the partition functions of critical models on toruses; and results as the critical point is approached are discussed [fr

Project on production of mutants by irradiation of in vitro cultured tissues of coconut and banana and their mass propagation by the tissue culture technique

International Nuclear Information System (INIS)

Guzman, E.V. de

1975-01-01

Fruit pulp tissue, ovary segments with or without ovules and sections from shoot tips of banana were used for studies on growth stimulating or morphogenetic effects of irradiation. Irradiation at 0.1-1.0 kR tended to induce faster callus growth in the otherwise slow-growing cultures. The physical condition and composition of the culture media especially with respect to growth regulators were studied, as were techniques to overcome discoloration of explants, the best choice of plant tissue for explant, and radiation effects on growth and morphogenesis. Due to the difficulty of callus induction with coconut, only the effects of irradiation on embryos cultured in vitro were studied. They were irradiated at various stages of development, i.e. during the early and final stage of liquid culture, and several days after transfer to a solid medium. Adverse effects of irradiation became evident only during the subsequent growth in solid, during the latter stage of which morphological changes were observed. Whereas irradiation of the liquid as well as solid media up to 50 kR had no adverse effect; survival and development became adversely affected at a dose of 1 kR

Substrate specific hydrolysis of aromatic and aromatic-aliphatic esters in orchid tissue cultures

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Agnieszka Mironowicz

2014-01-01

Full Text Available We found that tissue cultures of higher plants were able, similarly as microorganisms, to transform low-molecular-weight chemical compounds. In tissue cultures of orchids (Cymbidium 'Saint Pierre' and Dendrobium phalaenopsis acetates of phenols and aromatic-aliphatic alcohols were hydrolyzed, whereas methyl esters of aromatic and aromatic-aliphatic acids did not undergo this reaction. Acetates of racemic aromatic-aliphatic alcohols were hydrolyzed with distinct enantiospecificity.

Self-Condensation Culture Enables Vascularization of Tissue Fragments for Efficient Therapeutic Transplantation

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Yoshinobu Takahashi

2018-05-01

Full Text Available Summary: Clinical transplantation of tissue fragments, including islets, faces a critical challenge because of a lack of effective strategies that ensure efficient engraftment through the timely integration of vascular networks. We recently developed a complex organoid engineering method by “self-condensation” culture based on mesenchymal cell-dependent contraction, thereby enabling dissociated heterotypic lineages including endothelial cells to self-organize in a spatiotemporal manner. Here, we report the successful adaptation of this method for generating complex tissues from diverse tissue fragments derived from various organs, including pancreatic islets. The self-condensation of human and mouse islets with endothelial cells not only promoted functionalization in culture but also massively improved post-transplant engraftment. Therapeutically, fulminant diabetic mice were more efficiently treated by a vascularized islet transplant compared with the conventional approach. Given the general limitations of post-transplant vascularization associated with 3D tissue-based therapy, our approach offers a promising means of enhancing efficacy in the context of therapeutic tissue transplantation. : Takahashi et al. report on generating vascularized islet tissue from humans and mice. After transplantation, vascularized islets significantly improve survival of diabetic mice, demonstrating the quick normalization of blood glucose compared with conventional islet transplantation. Keywords: tissue engineering, tissue-based therapy, vascularization, islet transplantation, organoid

Monitoring Dynamic Interactions between Breast Cancer Cells and Human Bone Tissue in a Co-Culture Model

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Contag, Christopher H.; Lie, Wen-Rong; Bammer, Marie C.; Hardy, Jonathan W.; Schmidt, Tobi L.; Maloney, William J.; King, Bonnie L.

2015-01-01

Purpose Bone is a preferential site of breast cancer metastasis and models are needed to study this process at the level of the microenvironment. We have used bioluminescence imaging (BLI) and multiplex biomarker immunoassays to monitor dynamic breast cancer cell behaviors in co-culture with human bone tissue. Procedures Femur tissue fragments harvested from hip replacement surgeries were co-cultured with luciferase-positive MDA-MB-231-fLuc cells. BLI was performed to quantify breast cell division and track migration relative to bone tissue. Breast cell colonization of bone tissues was assessed with immunohistochemistry. Biomarkers in co-culture supernatants were profiled with MILLIPLEX® immunoassays. Results BLI demonstrated increased MDA-MB-231-fLuc proliferation (pbones, and revealed breast cell migration toward bone. Immunohistochemistry illustrated MDA-MB-231-fLuc colonization of bone, and MILLIPLEX® profiles of culture supernatants suggested breast/bone crosstalk. Conclusions Breast cell behaviors that facilitate metastasis occur reproducibly in human bone tissue co-cultures and can be monitored and quantified using BLI and multiplex immunoassays. PMID:24008275

Air exposure induced characteristics of dry eye in conjunctival tissue culture.

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Hui Lin

Full Text Available There are several animal models illustrating dry eye pathophysiology. Current study would like to establish an ex vivo tissue culture model for characterizing dry eye. Human conjunctival explants were cultured under airlift or submerged conditions for up to 2 weeks, and only airlifted conjunctival cultures underwent increased epithelial stratification. Starting on day 4, the suprabasal cells displayed decreased K19 expression whereas K10 keratin became evident in airlift group. Pax6 nuclear expression attenuated already at 2 days, while its perinuclear and cytoplasmic expression gradually increased. MUC5AC and MUC19 expression dramatically decreased whereas the full thickness MUC4 and MUC16 expression pattern disappeared soon after initiating the airlift condition. Real time PCR showed K16, K10 and MUC16 gene up-regulated while K19, MUC5AC, MUC19 and MUC4 down-regulated on day 8 and day 14. On day 2 was the appearance of apoptotic epithelial and stromal cells appeared. The Wnt signaling pathway was transiently activated from day 2 to day 10. The inflammatory mediators IL-1β, TNF-α, and MMP-9 were detected in the conditioned media after 6 to 8 days. In conclusion, airlifted conjunctival tissue cultures demonstrated Wnt signaling pathway activation, coupled with squamous metaplasia, mucin pattern alteration, apoptosis and upregulation of proinflammatory cytokine expression. These changes mimic the pathohistological alterations described in dry eye. This correspondence suggests that insight into the pathophysiology of dry eye may be aided through the use of airlifted conjunctival tissue cultures.

Tumor cell culture on collagen–chitosan scaffolds as three-dimensional tumor model: A suitable model for tumor studies

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Aziz Mahmoudzadeh

2016-07-01

Full Text Available Tumor cells naturally live in three-dimensional (3D microenvironments, while common laboratory tests and evaluations are done in two-dimensional (2D plates. This study examined the impact of cultured 4T1 cancer cells in a 3D collagen–chitosan scaffold compared with 2D plate cultures. Collagen–chitosan scaffolds were provided and passed confirmatory tests. 4T1 tumor cells were cultured on scaffolds and then tumor cells growth rate, resistance to X-ray radiation, and cyclophosphamide as a chemotherapy drug were analyzed. Furthermore, 4T1 cells were extracted from the scaffold model and were injected into the mice. Tumor growth rate, survival rate, and systemic immune responses were evaluated. Our results showed that 4T1 cells infiltrated the scaffolds pores and constructed a 3D microenvironment. Furthermore, 3D cultured tumor cells showed a slower proliferation rate, increased levels of survival to the X-ray irradiation, and enhanced resistance to chemotherapy drugs in comparison with 2D plate cultures. Transfer of extracted cells to the mice caused enhanced tumor volume and decreased life span. This study indicated that collagen–chitosan nanoscaffolds provide a suitable model of tumor that would be appropriate for tumor studies.

Tumor cell culture on collagen-chitosan scaffolds as three-dimensional tumor model: A suitable model for tumor studies.

Science.gov (United States)

Mahmoudzadeh, Aziz; Mohammadpour, Hemn

2016-07-01

Tumor cells naturally live in three-dimensional (3D) microenvironments, while common laboratory tests and evaluations are done in two-dimensional (2D) plates. This study examined the impact of cultured 4T1 cancer cells in a 3D collagen-chitosan scaffold compared with 2D plate cultures. Collagen-chitosan scaffolds were provided and passed confirmatory tests. 4T1 tumor cells were cultured on scaffolds and then tumor cells growth rate, resistance to X-ray radiation, and cyclophosphamide as a chemotherapy drug were analyzed. Furthermore, 4T1 cells were extracted from the scaffold model and were injected into the mice. Tumor growth rate, survival rate, and systemic immune responses were evaluated. Our results showed that 4T1 cells infiltrated the scaffolds pores and constructed a 3D microenvironment. Furthermore, 3D cultured tumor cells showed a slower proliferation rate, increased levels of survival to the X-ray irradiation, and enhanced resistance to chemotherapy drugs in comparison with 2D plate cultures. Transfer of extracted cells to the mice caused enhanced tumor volume and decreased life span. This study indicated that collagen-chitosan nanoscaffolds provide a suitable model of tumor that would be appropriate for tumor studies. Copyright © 2016. Published by Elsevier B.V.

Pathogen and biological contamination management in plant tissue culture: phytopathogens, vitro pathogens, and vitro pests.

Science.gov (United States)

Cassells, Alan C

2012-01-01

The ability to establish and grow plant cell, organ, and tissue cultures has been widely exploited for basic and applied research, and for the commercial production of plants (micro-propagation). Regardless of whether the application is for research or commerce, it is essential that the cultures be established in vitro free of biological contamination and be maintained as aseptic cultures during manipulation, growth, and storage. The risks from microbial contamination are spurious experimental results due to the effects of latent contaminants or losses of valuable experimental or commercial cultures. Much of the emphasis in culture contamination management historically focussed on the elimination of phytopathogens and the maintenance of cultures free from laboratory contamination by environmental bacteria, fungi (collectively referred to as "vitro pathogens", i.e. pathogens or environmental micro-organisms which cause culture losses), and micro-arthropods ("vitro pests"). Microbial contamination of plant tissue cultures is due to the high nutrient availability in the almost universally used Murashige and Skoog (Physiol Plant 15:473-497, 1962) basal medium or variants of it. In recent years, it has been shown that many plants, especially perennials, are at least locally endophytically colonized intercellularly by bacteria. The latter, and intracellular pathogenic bacteria and viruses/viroids, may pass latently into culture and be spread horizontally and vertically in cultures. Growth of some potentially cultivable endophytes may be suppressed by the high salt and sugar content of the Murashige and Skoog basal medium and suboptimal temperatures for their growth in plant tissue growth rooms. The management of contamination in tissue culture involves three stages: disease screening (syn. disease indexing) of the stock plants with disease and endophyte elimination where detected; establishment and pathogen and contaminant screening of established initial cultures

Protein and Glycoprotein Patterns Related to Morphogenesis in Mammillaria gracillis Pfeiff. Tissue Culture

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Biljana Balen

2002-01-01

Full Text Available As plants with Crassulacean Acid Metabolism (CAM, cacti are highly affected by artificial environmental conditions in tissue culture. Plants of Mammillaria gracillis Pfeiff. (Cactaceae propagated in vitro produced callus spontaneously. This habituated callus regenerated normal and hyperhydric shoots without the addition of growth regulators. In order to compare habituated callus with the tumorous one, cactus cells were transformed with two strains of Agrobacterium tumefaciens: the wild strain B6S3 (tumour line TW and the rooty mutant GV3101 (tumour line TR. Gene expression in cactus plants, habituated callus, regenerated shoots and two tumour lines was analysed at the level of cellular and extracellular protein and glycoprotein profiles. Proteins were separated by SDS-polyacrylamide gel electrophoresis and 2-D PAGE electrophoresis and silver stained. Concavalin A-peroxidase staining detected glycoproteins with D-manose in their glycan component on protein blots. Developmentally specific protein patterns of Mammillaria gracillis tissue lines were detected. The 2-D PAGE electrophoresis revealed some tissue specific protein groups. The cellular glycoprotein of 42 kDa detected by ConA was highly expressed in undifferentiated tissues (habituated callus, TW and TR tumours and in hyperhydric regenerants. Tumours produced extracellular proteins of 33, 23 and 22 kDa. The N glycosylation of cellular and extracellular proteins was related to specific developmental stage of cactus tissue.

Characterization of primary human mammary epithelial cells isolated and propagated by conditional reprogrammed cell culture.

Science.gov (United States)

Jin, Liting; Qu, Ying; Gomez, Liliana J; Chung, Stacey; Han, Bingchen; Gao, Bowen; Yue, Yong; Gong, Yiping; Liu, Xuefeng; Amersi, Farin; Dang, Catherine; Giuliano, Armando E; Cui, Xiaojiang

2018-02-20

Conditional reprogramming methods allow for the inexhaustible in vitro proliferation of primary epithelial cells from human tissue specimens. This methodology has the potential to enhance the utility of primary cell culture as a model for mammary gland research. However, few studies have systematically characterized this method in generating in vitro normal human mammary epithelial cell models. We show that cells derived from fresh normal breast tissues can be propagated and exhibit heterogeneous morphologic features. The cultures are composed of CK18, desmoglein 3, and CK19-positive luminal cells and vimentin, p63, and CK14-positive myoepithelial cells, suggesting the maintenance of in vivo heterogeneity. In addition, the cultures contain subpopulations with different CD49f and EpCAM expression profiles. When grown in 3D conditions, cells self-organize into distinct structures that express either luminal or basal cell markers. Among these structures, CK8-positive cells enclosing a lumen are capable of differentiation into milk-producing cells in the presence of lactogenic stimulus. Furthermore, our short-term cultures retain the expression of ERα, as well as its ability to respond to estrogen stimulation. We have investigated conditionally reprogrammed normal epithelial cells in terms of cell type heterogeneity, cellular marker expression, and structural arrangement in two-dimensional (2D) and three-dimensional (3D) systems. The conditional reprogramming methodology allows generation of a heterogeneous culture from normal human mammary tissue in vitro . We believe that this cell culture model will provide a valuable tool to study mammary cell function and malignant transformation.

Development of an acellular tumor extracellular matrix as a three-dimensional scaffold for tumor engineering.

Directory of Open Access Journals (Sweden)

Wei-Dong Lü

Full Text Available Tumor engineering is defined as the construction of three-dimensional (3D tumors in vitro with tissue engineering approaches. The present 3D scaffolds for tumor engineering have several limitations in terms of structure and function. To get an ideal 3D scaffold for tumor culture, A549 human pulmonary adenocarcinoma cells were implanted into immunodeficient mice to establish xenotransplatation models. Tumors were retrieved at 30-day implantation and sliced into sheets. They were subsequently decellularized by four procedures. Two decellularization methods, Tris-Trypsin-Triton multi-step treatment and sodium dodecyl sulfate (SDS treatment, achieved complete cellular removal and thus were chosen for evaluation of histological and biochemical properties. Native tumor tissues were used as controls. Human breast cancer MCF-7 cells were cultured onto the two 3D scaffolds for further cell growth and growth factor secretion investigations, with the two-dimensional (2D culture and cells cultured onto the Matrigel scaffolds used as controls. Results showed that Tris-Trypsin-Triton multi-step treated tumor sheets had well-preserved extracellular matrix structures and components. Their porosity was increased but elastic modulus was decreased compared with the native tumor samples. They supported MCF-7 cell repopulation and proliferation, as well as expression of growth factors. When cultured within the Tris-Trypsin-Triton treated scaffold, A549 cells and human colorectal adenocarcinoma cells (SW-480 had similar behaviors to MCF-7 cells, but human esophageal squamous cell carcinoma cells (KYSE-510 had a relatively slow cell repopulation rate. This study provides evidence that Tris-Trypsin-Triton treated acellular tumor extracellular matrices are promising 3D scaffolds with ideal spatial arrangement, biomechanical properties and biocompatibility for improved modeling of 3D tumor microenvironments.

Two-dimensional capillary origami

Energy Technology Data Exchange (ETDEWEB)

Brubaker, N.D., E-mail: nbrubaker@math.arizona.edu; Lega, J., E-mail: lega@math.arizona.edu

2016-01-08

We describe a global approach to the problem of capillary origami that captures all unfolded equilibrium configurations in the two-dimensional setting where the drop is not required to fully wet the flexible plate. We provide bifurcation diagrams showing the level of encapsulation of each equilibrium configuration as a function of the volume of liquid that it contains, as well as plots representing the energy of each equilibrium branch. These diagrams indicate at what volume level the liquid drop ceases to be attached to the endpoints of the plate, which depends on the value of the contact angle. As in the case of pinned contact points, three different parameter regimes are identified, one of which predicts instantaneous encapsulation for small initial volumes of liquid. - Highlights: • Full solution set of the two-dimensional capillary origami problem. • Fluid does not necessarily wet the entire plate. • Global energy approach provides exact differential equations satisfied by minimizers. • Bifurcation diagrams highlight three different regimes. • Conditions for spontaneous encapsulation are identified.

Two-dimensional capillary origami

International Nuclear Information System (INIS)

Brubaker, N.D.; Lega, J.

2016-01-01

We describe a global approach to the problem of capillary origami that captures all unfolded equilibrium configurations in the two-dimensional setting where the drop is not required to fully wet the flexible plate. We provide bifurcation diagrams showing the level of encapsulation of each equilibrium configuration as a function of the volume of liquid that it contains, as well as plots representing the energy of each equilibrium branch. These diagrams indicate at what volume level the liquid drop ceases to be attached to the endpoints of the plate, which depends on the value of the contact angle. As in the case of pinned contact points, three different parameter regimes are identified, one of which predicts instantaneous encapsulation for small initial volumes of liquid. - Highlights: • Full solution set of the two-dimensional capillary origami problem. • Fluid does not necessarily wet the entire plate. • Global energy approach provides exact differential equations satisfied by minimizers. • Bifurcation diagrams highlight three different regimes. • Conditions for spontaneous encapsulation are identified.

Mesenchymal stem cell cultivation in electrospun scaffolds: mechanistic modeling for tissue engineering.

Science.gov (United States)

Paim, Ágata; Tessaro, Isabel C; Cardozo, Nilo S M; Pranke, Patricia

2018-03-05

Tissue engineering is a multidisciplinary field of research in which the cells, biomaterials, and processes can be optimized to develop a tissue substitute. Three-dimensional (3D) architectural features from electrospun scaffolds, such as porosity, tortuosity, fiber diameter, pore size, and interconnectivity have a great impact on cell behavior. Regarding tissue development in vitro, culture conditions such as pH, osmolality, temperature, nutrient, and metabolite concentrations dictate cell viability inside the constructs. The effect of different electrospun scaffold properties, bioreactor designs, mesenchymal stem cell culture parameters, and seeding techniques on cell behavior can be studied individually or combined with phenomenological modeling techniques. This work reviews the main culture and scaffold factors that affect tissue development in vitro regarding the culture of cells inside 3D matrices. The mathematical modeling of the relationship between these factors and cell behavior inside 3D constructs has also been critically reviewed, focusing on mesenchymal stem cell culture in electrospun scaffolds.

Two-dimensional black holes and non-commutative spaces

International Nuclear Information System (INIS)

Sadeghi, J.

2008-01-01

We study the effects of non-commutative spaces on two-dimensional black hole. The event horizon of two-dimensional black hole is obtained in non-commutative space up to second order of perturbative calculations. A lower limit for the non-commutativity parameter is also obtained. The observer in that limit in contrast to commutative case see two horizon

Two-dimensional Navier-Stokes turbulence in bounded domains

NARCIS (Netherlands)

Clercx, H.J.H.; van Heijst, G.J.F.

In this review we will discuss recent experimental and numerical results of quasi-two-dimensional decaying and forced Navier–Stokes turbulence in bounded domains. We will give a concise overview of developments in two-dimensional turbulence research, with emphasis on the progress made during the

Two-dimensional Navier-Stokes turbulence in bounded domains

NARCIS (Netherlands)

Clercx, H.J.H.; Heijst, van G.J.F.

2009-01-01

In this review we will discuss recent experimental and numerical results of quasi-two-dimensional decaying and forced Navier–Stokes turbulence in bounded domains. We will give a concise overview of developments in two-dimensional turbulence research, with emphasis on the progress made during the

Piezoelectricity in Two-Dimensional Materials

KAUST Repository

Wu, Tao; Zhang, Hua

2015-01-01

Powering up 2D materials: Recent experimental studies confirmed the existence of piezoelectricity - the conversion of mechanical stress into electricity - in two-dimensional single-layer MoS2 nanosheets. The results represent a milestone towards

Selection of seed lots of Pinus taeda L. for tissue culture

Directory of Open Access Journals (Sweden)

Diego Pascoal Golle

2014-06-01

Full Text Available The aim of this work was to identify the fungi genera associated with three Pinus taeda L. seed lots and to assess the sanitary and physiological quality of these lots for use as selection criteria for tissue culture and evaluate the in vitro establishment of explants from seminal origin in different nutritive media. It was possible to discriminate the lots on the sanitary and physiological quality, as well as to establish in vitro plants of Pinus taeda from cotyledonary nodes obtained from aseptic seed germination of a selected lot by the sanitary and physiological quality higher. The nutritive media MS, ½ MS and WPM were equally suitable for this purpose. For the sanitary analysis the fungal genera Fusarium, Penicillium and Trichoderma were those of the highest sensitivity. For the physiological evaluation were important the variables: abnormal seedlings, strong normal seedlings; length, fresh and dry weight of strong normal seedlings. The analyzes were favorable to choose lots of seeds for in vitro culture and all culture media were adequate for the establishment of this species in tissue culture.

Transcriptomic comparisons between cultured human adipose tissue-derived pericytes and mesenchymal stromal cells

Directory of Open Access Journals (Sweden)

Lindolfo da Silva Meirelles

2016-03-01

Full Text Available Mesenchymal stromal cells (MSCs, sometimes called mesenchymal stem cells, are cultured cells able to give rise to mature mesenchymal cells such as adipocytes, osteoblasts, and chondrocytes, and to secrete a wide range of trophic and immunomodulatory molecules. Evidence indicates that pericytes, cells that surround and maintain physical connections with endothelial cells in blood vessels, can give rise to MSCs (da Silva Meirelles et al., 2008 [1]; Caplan and Correa, 2011 [2]. We have compared the transcriptomes of highly purified, human adipose tissue pericytes subjected to culture-expansion in pericyte medium or MSC medium, with that of human adipose tissue MSCs isolated with traditional methods to test the hypothesis that their transcriptomes are similar (da Silva Meirelles et al., 2015 [3]. Here, we provide further information and analyses of microarray data from three pericyte populations cultured in pericyte medium, three pericyte populations cultured in MSC medium, and three adipose tissue MSC populations deposited in the Gene Expression Omnibus under accession number GSE67747. Keywords: Mesenchymal stromal cells, Mesenchymal stem cells, Pericytes, Microarrays

THE EFFECTS OF GLYCOL METHACRYLATE AS A DEHYDRATING AGENT ON THE DIMENSIONAL CHANGES OF LIVER-TISSUE

NARCIS (Netherlands)

GERRITS, PO; HOROBIN, RW; STOKROOS, [No Value

The dimensional changes of liver sections during the course of processing with glycol methacrylate (GMA) or with ethanol are described. Tissue processing with ethanol served as a control. During prolonged processing steps (24 h each), linear shrinkage of tissue specimens dehydrated with GMA at room

Solution of the two-dimensional spectral factorization problem

Science.gov (United States)

Lawton, W. M.

1985-01-01

An approximation theorem is proven which solves a classic problem in two-dimensional (2-D) filter theory. The theorem shows that any continuous two-dimensional spectrum can be uniformly approximated by the squared modulus of a recursively stable finite trigonometric polynomial supported on a nonsymmetric half-plane.

Frozen and fresh ovarian tissue require different culture media to promote in vitro development of bovine preantral follicles.

Science.gov (United States)

Castro, Simone Vieira; Carvalho, Adeline Andrade; Silva, Cleidson Manoel Gomes; Santos, Francielli Weber; Campello, Cláudio Cabral; de Figueiredo, José Ricardo; Rodrigues, Ana Paula Ribeiro

2014-10-01

The aim of this study was to evaluate the efficiency of different media in the in vitro culture of bovine preantral follicles that were used either fresh or following slow freezing treatment. Frozen and fresh noncultured or cultured ovarian fragments were processed for histological, viability, and cell proliferation analyses. For cryopreservation, a solution containing 1.5 M ethylene glycol was frozen in a programmable biological freezer. After thawing, a portion of the samples was destined for frozen controls. The remainder were cultured in vitro for 5 days in three media: α-MEM, McCoy, or M199. Samples from these culture media were collected on days 1 and 5 for quantification of reactive oxygen species (ROS) and for hormonal assays. In fresh-cultured tissues, the percentage of morphologically normal follicles was significantly higher when cultured in M199 compared to that in the other media. In frozen-cultured tissues, McCoy medium was significantly superior to the other media, and was the only treatment that helped in maintaining the viability similar to fresh and frozen controls. Upon quantification of the nucleolus organizer region, we observed greater proliferation of granulosa cells in the frozen-cultured tissues with McCoy medium, and lesser proliferation in fresh-cultured tissues only with α-MEM. In frozen-cultured tissues, ROS levels were highest at day 1 and progressively reduced during culture, independent of the media used. In conclusion, under the conditions used in this study, the M199 and McCoy media are recommended for the culture of follicles derived from fresh and frozen ovarian tissues, respectively.

Bioprinting of a mechanically enhanced three-dimensional dual cell-laden construct for osteochondral tissue engineering using a multi-head tissue/organ building system

International Nuclear Information System (INIS)

Shim, Jin-Hyung; Lee, Jung-Seob; Cho, Dong-Woo; Kim, Jong Young

2012-01-01

The aim of this study was to build a mechanically enhanced three-dimensional (3D) bioprinted construct containing two different cell types for osteochondral tissue regeneration. Recently, the production of 3D cell-laden structures using various scaffold-free cell printing technologies has opened up new possibilities. However, ideal 3D complex tissues or organs have not yet been printed because gel-state hydrogels have been used as the principal material and are unable to maintain the desired 3D structure due to their poor mechanical strength. In this study, thermoplastic biomaterial polycaprolactone (PCL), which shows relatively high mechanical properties as compared with hydrogel, was used as a framework for enhancing the mechanical stability of the bioprinted construct. Two different alginate solutions were then infused into the previously prepared framework consisting of PCL to create the 3D construct for osteochondral printing. For this work, a multi-head tissue/organ building system (MtoBS), which was particularly designed to dispense thermoplastic biomaterial and hydrogel having completely different rheology properties, was newly developed and used to bioprint osteochondral tissue. It was confirmed that the line width, position and volume control of PCL and alginate solutions were adjustable in the MtoBS. Most importantly, dual cell-laden 3D constructs consisting of osteoblasts and chondrocytes were successfully fabricated. Further, the separately dispensed osteoblasts and chondrocytes not only retained their initial position and viability, but also proliferated up to 7 days after being dispensed. (paper)

Bioprinting of a mechanically enhanced three-dimensional dual cell-laden construct for osteochondral tissue engineering using a multi-head tissue/organ building system

Science.gov (United States)

Shim, Jin-Hyung; Lee, Jung-Seob; Kim, Jong Young; Cho, Dong-Woo

2012-08-01

The aim of this study was to build a mechanically enhanced three-dimensional (3D) bioprinted construct containing two different cell types for osteochondral tissue regeneration. Recently, the production of 3D cell-laden structures using various scaffold-free cell printing technologies has opened up new possibilities. However, ideal 3D complex tissues or organs have not yet been printed because gel-state hydrogels have been used as the principal material and are unable to maintain the desired 3D structure due to their poor mechanical strength. In this study, thermoplastic biomaterial polycaprolactone (PCL), which shows relatively high mechanical properties as compared with hydrogel, was used as a framework for enhancing the mechanical stability of the bioprinted construct. Two different alginate solutions were then infused into the previously prepared framework consisting of PCL to create the 3D construct for osteochondral printing. For this work, a multi-head tissue/organ building system (MtoBS), which was particularly designed to dispense thermoplastic biomaterial and hydrogel having completely different rheology properties, was newly developed and used to bioprint osteochondral tissue. It was confirmed that the line width, position and volume control of PCL and alginate solutions were adjustable in the MtoBS. Most importantly, dual cell-laden 3D constructs consisting of osteoblasts and chondrocytes were successfully fabricated. Further, the separately dispensed osteoblasts and chondrocytes not only retained their initial position and viability, but also proliferated up to 7 days after being dispensed.

Development of Two-Dimensional NMR

Indian Academy of Sciences (India)

Home; Journals; Resonance – Journal of Science Education; Volume 20; Issue 11. Development of Two-Dimensional NMR: Strucure Determination of Biomolecules in Solution. Anil Kumar. General Article Volume 20 Issue 11 November 2015 pp 995-1002 ...

ONE-DIMENSIONAL AND TWO-DIMENSIONAL LEADERSHIP STYLES

OpenAIRE

Nikola Stefanović

2007-01-01

In order to motivate their group members to perform certain tasks, leaders use different leadership styles. These styles are based on leaders' backgrounds, knowledge, values, experiences, and expectations. The one-dimensional styles, used by many world leaders, are autocratic and democratic styles. These styles lie on the two opposite sides of the leadership spectrum. In order to precisely define the leadership styles on the spectrum between the autocratic leadership style and the democratic ...

Infrared magneto-spectroscopy of two-dimensional and three-dimensional massless fermions: A comparison

Energy Technology Data Exchange (ETDEWEB)

Orlita, M., E-mail: milan.orlita@lncmi.cnrs.fr [Laboratoire National des Champs Magnétiques Intenses, CNRS-UJF-UPS-INSA, 38042 Grenoble (France); Faculty of Mathematics and Physics, Charles University, Ke Karlovu 5, 121 16 Prague 2 (Czech Republic); Faugeras, C.; Barra, A.-L.; Martinez, G.; Potemski, M. [Laboratoire National des Champs Magnétiques Intenses, CNRS-UJF-UPS-INSA, 38042 Grenoble (France); Basko, D. M. [LPMMC UMR 5493, Université Grenoble 1/CNRS, B.P. 166, 38042 Grenoble (France); Zholudev, M. S. [Laboratoire Charles Coulomb (L2C), UMR CNRS 5221, GIS-TERALAB, Université Montpellier II, 34095 Montpellier (France); Institute for Physics of Microstructures, RAS, Nizhny Novgorod GSP-105 603950 (Russian Federation); Teppe, F.; Knap, W. [Laboratoire Charles Coulomb (L2C), UMR CNRS 5221, GIS-TERALAB, Université Montpellier II, 34095 Montpellier (France); Gavrilenko, V. I. [Institute for Physics of Microstructures, RAS, Nizhny Novgorod GSP-105 603950 (Russian Federation); Mikhailov, N. N.; Dvoretskii, S. A. [A.V. Rzhanov Institute of Semiconductor Physics, Siberian Branch, Russian Academy of Sciences, Novosibirsk 630090 (Russian Federation); Neugebauer, P. [Institut für Physikalische Chemie, Universität Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart (Germany); Berger, C. [School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States); Institut Néel/CNRS-UJF BP 166, F-38042 Grenoble Cedex 9 (France); Heer, W. A. de [School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States)

2015-03-21

Here, we report on a magneto-optical study of two distinct systems hosting massless fermions—two-dimensional graphene and three-dimensional HgCdTe tuned to the zero band gap condition at the point of the semiconductor-to-semimetal topological transition. Both materials exhibit, in the quantum regime, a fairly rich magneto-optical response, which is composed from a series of intra- and interband inter-Landau level resonances with for massless fermions typical √(B) dependence. The impact of the system's dimensionality and of the strength of the spin-orbit interaction on the optical response is also discussed.

One-dimensional versus two-dimensional electronic states in vicinal surfaces

International Nuclear Information System (INIS)

Ortega, J E; Ruiz-Oses, M; Cordon, J; Mugarza, A; Kuntze, J; Schiller, F

2005-01-01

Vicinal surfaces with periodic arrays of steps are among the simplest lateral nanostructures. In particular, noble metal surfaces vicinal to the (1 1 1) plane are excellent test systems to explore the basic electronic properties in one-dimensional superlattices by means of angular photoemission. These surfaces are characterized by strong emissions from free-electron-like surface states that scatter at step edges. Thereby, the two-dimensional surface state displays superlattice band folding and, depending on the step lattice constant d, it splits into one-dimensional quantum well levels. Here we use high-resolution, angle-resolved photoemission to analyse surface states in a variety of samples, in trying to illustrate the changes in surface state bands as a function of d

Densis. Densimetric representation of two-dimensional matrices

International Nuclear Information System (INIS)

Los Arcos Merino, J.M.

1978-01-01

Densis is a Fortran V program which allows off-line control of a Calcomp digital plotter, to represent a two-dimensional matrix of numerical elements in the form of a variable shading intensity map in two colours. Each matrix element is associated to a square of a grid which is traced over by lines whose number is a function of the element value according to a selected scale. Program features, subroutine structure and running instructions, are described. Some typical results, for gamma-gamma coincidence experimental data and a sampled two-dimensional function, are indicated. (author)

[18S-25S rDNA variation in tissue culture of some Gentiana L. species].

Science.gov (United States)

Mel'nyk, V M; Andrieiev, I O; Spiridonova, K V; Strashniuk, N M; Kunakh, V A

2007-01-01

18S-25S rDNA of intact plants and tissue cultures of G. acaulis, G. punctata and G. lutea have been investigated by using blot-hybridization. The decrease of rDNA amount was found in the callus cultures as compared with the plants. In contrast to other species, G. lutea showed intragenome heterogeneity of rRNA genes as well as qualitative rDNA changes in tissue culture, in particular appearance of altered repeats. The relationship between the peculiarities of rRNA gene structure and their rearrangements in in vitro culture was suggested.

Three-Dimensional Printing Articular Cartilage: Recapitulating the Complexity of Native Tissue.

Science.gov (United States)

Guo, Ting; Lembong, Josephine; Zhang, Lijie Grace; Fisher, John P

2017-06-01

In the past few decades, the field of tissue engineering combined with rapid prototyping (RP) techniques has been successful in creating biological substitutes that mimic tissues. Its applications in regenerative medicine have drawn efforts in research from various scientific fields, diagnostics, and clinical translation to therapies. While some areas of therapeutics are well developed, such as skin replacement, many others such as cartilage repair can still greatly benefit from tissue engineering and RP due to the low success and/or inefficiency of current existing, often surgical treatments. Through fabrication of complex scaffolds and development of advanced materials, RP provides a new avenue for cartilage repair. Computer-aided design and three-dimensional (3D) printing allow the fabrication of modeled cartilage scaffolds for repair and regeneration of damaged cartilage tissues. Specifically, the various processes of 3D printing will be discussed in details, both cellular and acellular techniques, covering the different materials, geometries, and operational printing conditions for the development of tissue-engineered articular cartilage. Finally, we conclude with some insights on future applications and challenges related to this technology, especially using 3D printing techniques to recapitulate the complexity of native structure for advanced cartilage regeneration.

Cell-surface glycoproteins of human sarcomas: differential expression in normal and malignant tissues and cultured cells

International Nuclear Information System (INIS)

Rettig, W.F.; Garin-Chesa, P.; Beresford, H.R.; Oettgen, H.F.; Melamed, M.R.; Old, L.J.

1988-01-01

Normal differentiation and malignant transformation of human cells are characterized by specific changes in surface antigen phenotype. In the present study, the authors have defined six cell-surface antigens of human sarcomas and normal mesenchymal cells, by using mixed hemadsorption assays and immunochemical methods for the analysis of cultured cells and immunohistochemical staining for the analysis of normal tissues and > 200 tumor specimens. Differential patterns of F19, F24, G171, G253, S5, and Thy-1 antigen expression were found to characterize (i) subsets of cultured sarcoma cell lines, (ii) cultured fibroblasts derived from various organs, (iii) normal resting and activated mesenchymal tissues, and (iv) sarcoma and nonmesenchymal tumor tissues. These results provide a basic surface antigenic map for cultured mesenchymal cells and mesenchymal tissues and permit the classification of human sarcomas according to their antigenic phenotypes

Resonance fluorescence based two- and three-dimensional atom localization

Science.gov (United States)

Wahab, Abdul; Rahmatullah; Qamar, Sajid

2016-06-01

Two- and three-dimensional atom localization in a two-level atom-field system via resonance fluorescence is suggested. For the two-dimensional localization, the atom interacts with two orthogonal standing-wave fields, whereas for the three-dimensional atom localization, the atom interacts with three orthogonal standing-wave fields. The effect of the detuning and phase shifts associated with the corresponding standing-wave fields is investigated. A precision enhancement in position measurement of the single atom can be noticed via the control of the detuning and phase shifts.

Toward two-dimensional search engines

International Nuclear Information System (INIS)

Ermann, L; Shepelyansky, D L; Chepelianskii, A D

2012-01-01

We study the statistical properties of various directed networks using ranking of their nodes based on the dominant vectors of the Google matrix known as PageRank and CheiRank. On average PageRank orders nodes proportionally to a number of ingoing links, while CheiRank orders nodes proportionally to a number of outgoing links. In this way, the ranking of nodes becomes two dimensional which paves the way for the development of two-dimensional search engines of a new type. Statistical properties of information flow on the PageRank–CheiRank plane are analyzed for networks of British, French and Italian universities, Wikipedia, Linux Kernel, gene regulation and other networks. A special emphasis is done for British universities networks using the large database publicly available in the UK. Methods of spam links control are also analyzed. (paper)

Subjective figure reversal in two- and three-dimensional perceptual space.

Science.gov (United States)

Radilová, J; Radil-Weiss, T

1984-08-01

A permanently illuminated pattern of Mach's truncated pyramid can be perceived according to the experimental instruction given, either as a three-dimensional reversible figure with spontaneously changing convex and concave interpretation (in one experiment), or as a two-dimensional reversible figure-ground pattern (in another experiment). The reversal rate was about twice as slow, without the subjects being aware of it, if it was perceived as a three-dimensional figure compared to the situation when it was perceived as two-dimensional. It may be hypothetized that in the three-dimensional case, the process of perception requires more sequential steps than in the two-dimensional one.

Simultaneous determination of D-aspartic acid and D-glutamic acid in rat tissues and physiological fluids using a multi-loop two-dimensional HPLC procedure.

Science.gov (United States)

Han, Hai; Miyoshi, Yurika; Ueno, Kyoko; Okamura, Chieko; Tojo, Yosuke; Mita, Masashi; Lindner, Wolfgang; Zaitsu, Kiyoshi; Hamase, Kenji

2011-11-01

For a metabolomics study focusing on the analysis of aspartic and glutamic acid enantiomers, a fully automated two-dimensional HPLC system employing a microbore-ODS column and a narrowbore-enantioselective column was developed. By using this system, a detailed distribution of D-Asp and D-Glu besides L-Asp and L-Glu in mammals was elucidated. For the total analysis concept, the amino acids were first pre-column derivatized with 4-fluoro-7-nitro-2,1,3-benzoxadiazole (NBD-F) to be sensitively and fluorometrically detected. For the non-stereoselective separation of the analytes in the first dimension a monolithic ODS column (750 mm × 0.53 mm i.d.) was adopted, and a self-packed narrowbore-Pirkle type enantioselective column (Sumichiral OA-2500S, 250 mm × 1.5 mm i.d.) was selected for the second dimension. In the rat plasma, RSD values for intra-day and inter-day precision were less than 6.8%, and the accuracy ranged between 96.1% and 105.8%. The values of LOQ of D-Asp and D-Glu were 5 fmol/injection (0.625 nmol/g tissue). The present method was successfully applied to the simultaneous determination of free aspartic acid and glutamic acid enantiomers in 7 brain areas, 11 peripheral tissues, plasma and urine of Wistar rats. Biologically significant D-Asp values were found in various tissue samples whereas for D-Glu the values were very low possibly indicating less significance. Copyright © 2011 Elsevier B.V. All rights reserved.

Pre-irradiation of tissue culture flasks leads to diminished stem and progenitor cell production in long-term bone marrow cultures

International Nuclear Information System (INIS)

Rooney, P.; Wright, E.G.

1993-01-01

Empty plastic tissue culture flasks were exposed to X-irradiation doses of 0.3-10.0 Gy, prior to the establishment of long-term bone marrow cultures. During the course of a 10 week culture period, all irradiated plastic flasks exhibited a dramatic decrease in the number of both haemopoietic stem cells and myeloid progenitor cells, in the non-adherent layer, when compared with controls. This decrease was not due to a decrease in the number of non-adherent cells produced. Histological examination of non-adherent cells showed an increase in mature granulocytic cells with few blast cells. Morphologically, the adherent layers of irradiated flasks demonstrated a delay in appearance or absence of fat cell production. X-irradiation of glass tissue culture flasks had no deleterious effect. (author)

Two multi-dimensional uncertainty relations

International Nuclear Information System (INIS)

Skala, L; Kapsa, V

2008-01-01

Two multi-dimensional uncertainty relations, one related to the probability density and the other one related to the probability density current, are derived and discussed. Both relations are stronger than the usual uncertainty relations for the coordinates and momentum

Three-dimensional analysis of elbow soft tissue footprints and anatomy.

Science.gov (United States)

Capo, John T; Collins, Christopher; Beutel, Bryan G; Danna, Natalie R; Manigrasso, Michaele; Uko, Linda A; Chen, Linda Y

2014-11-01

Tendinous and ligamentous injuries commonly occur in the elbow. This study characterized the location, surface areas, and origin and insertional footprints of major elbow capsuloligamentous and tendinous structures in relation to bony landmarks with the use of a precision 3-dimensional modeling system. Nine unpaired cadaveric elbow specimens were dissected and mounted on a custom jig. Mapping of the medial collateral ligament (MCL), lateral ulnar collateral ligament (LUCL), triceps, biceps, brachialis, and capsular reflections was then performed with 3-dimensional digitizing technology. The location, surface areas, and footprints of the soft tissues were calculated. The MCL had a mean origin (humeral) footprint of 216 mm(2), insertional footprint of 154 mm(2), and surface area of 421 mm(2). The LUCL had a mean origin footprint of 136 mm(2), an insertional footprint of 142 mm(2), and a surface area of 532 mm(2). Of the tendons, the triceps maintained the largest insertional footprint, followed by the brachialis and the biceps (P anatomy of key elbow capsuloligamentous and tendinous structures is crucial for effective reconstruction after bony or soft tissue trauma. This study provides the upper extremity surgeon with information that may aid in restoring elbow biomechanics and preserving range of motion in these patients. Copyright © 2014 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

Mechanical exfoliation of two-dimensional materials

Science.gov (United States)

Gao, Enlai; Lin, Shao-Zhen; Qin, Zhao; Buehler, Markus J.; Feng, Xi-Qiao; Xu, Zhiping

2018-06-01

Two-dimensional materials such as graphene and transition metal dichalcogenides have been identified and drawn much attention over the last few years for their unique structural and electronic properties. However, their rise begins only after these materials are successfully isolated from their layered assemblies or adhesive substrates into individual monolayers. Mechanical exfoliation and transfer are the most successful techniques to obtain high-quality single- or few-layer nanocrystals from their native multi-layer structures or their substrate for growth, which involves interfacial peeling and intralayer tearing processes that are controlled by material properties, geometry and the kinetics of exfoliation. This procedure is rationalized in this work through theoretical analysis and atomistic simulations. We propose a criterion to assess the feasibility for the exfoliation of two-dimensional sheets from an adhesive substrate without fracturing itself, and explore the effects of material and interface properties, as well as the geometrical, kinetic factors on the peeling behaviors and the torn morphology. This multi-scale approach elucidates the microscopic mechanism of the mechanical processes, offering predictive models and tools for the design of experimental procedures to obtain single- or few-layer two-dimensional materials and structures.

Lemongrass-Incorporated Tissue Conditioner Against Candida albicans Culture

Science.gov (United States)

Amornvit, Pokpong; Srithavaj, Theerathavaj

2014-01-01

Background: Tissue conditioner is applied popularly with dental prosthesis during wound healing process but it becomes a reservoir of oral microbiota, especially Candida species after long-term usage. Several antifungal drugs have been mixed with this material to control fungal level. In this study, lemongrass essential oil was added into COE-COMFORT tissue conditioner before being determined for anti-Candida efficacy. Materials and Methods: Lemongrass (Cymbopogon citratus) essential oil was primarily determined for antifungal activity against C. albicans American type culture collection (ATCC) 10231 and MIC (minimum inhibitory concentration) value by agar disk diffusion and broth microdilution methods, respectively. COE-COMFORT tissue conditioner was prepared as recommended by the manufacturer after a fixed volume of the oil at its MIC or higher concentrations were mixed thoroughly in its liquid part. Antifungal efficacy of the tissue conditioner with/without herb was finally analyzed. Results: Lemongrass essential oil displayed potent antifungal activity against C. albicans ATCC 10231and its MIC value was 0.06% (v/v). Dissimilarly, the tissue conditioner containing the oil at MIC level did not cease the growth of the tested fungus. Both reference and clinical isolates of C. albicans were completely inhibited after exposed to the tissue conditioner containing at least 0.25% (v/v) of the oil (approximately 4-time MIC). The tissue conditioner without herb or with nystatin was employed as negative or positive control, respectively. Conclusion: COE-COMFORT tissue conditioner supplemented with lemongrass essential oil obviously demonstrated another desirable property as in vitro anti-Candida efficacy to minimize the risk of getting Candidal infection. PMID:25177638

Ultrasonic characterization of three animal mammary tumors from three-dimensional acoustic tissue models

Science.gov (United States)

Mamou, Jonathan M.

This dissertation investigated how three-dimensional (3D) tissue models can be used to improve ultrasonic tissue characterization (UTC) techniques. Anatomic sites in tissue responsible for ultrasonic scattering are unknown, which limits the potential applications of ultrasound for tumor diagnosis. Accurate 3D models of tumor tissues may help identify the scattering sites. Three mammary tumors were investigated: a rat fibroadenoma, a mouse carcinoma, and a mouse sarcoma. A 3D acoustic tissue model, termed 3D impedance map (3DZM), was carefully constructed from consecutive histologic sections for each tumor. Spectral estimates (scatterer size and acoustic concentration) were obtained from the 3DZMs and compared to the same estimates obtained with ultrasound. Scatterer size estimates for three tumors were found to be similar (within 10%). The 3DZMs were also used to extract tissue-specific scattering models. The scattering models were found to allow clear distinction between the three tumors. This distinction demonstrated that UTC techniques may be helpful for noninvasive clinical tumor diagnosis.

Production of mutants by irradiation of in vitro-cultured tissues of coconut and banana and their mass propagation by the tissue culture technique

International Nuclear Information System (INIS)

Guzman, E.V. de; Rosario, A.G. del; Pagcaliwagan, P.C.

1982-01-01

Regeneration of buds/shoots as well as plantlets was induced from banana shoot tip explants cultured in highly modified Murashige and Skoog's medium supplemented with coconut water and benzyladenine. Initially shoot regeneration was sparse, but on further subculture became profuse. Gamma irradiation at low dosage (1.0 kR) was stimulating to explant growth and bud formation with the two types of explants used. With Bungulan stimulation was observed even at 2.5 kR. Several morphological aberrations were exhibited by shoots of 'irradiated' in vitro plants growing in potted soil. A highly and continuously proliferating tissue strain has been isolated from a subculture which was ultimately derived from an irradiated explant. Its continued proliferation is dependent on an external supply of coconut water and benzyladenine. In vitro-produced plants have been established under field conditions. The 'irradiated' plants are comparable with, and some seem to be better than, the unirradiated controls with respect to height, girth, sucker production and number of hands and fingers per bunch. Higher doses of irradiation are required to produce an adverse effect on growth of coconut embryos during the liquid culture than when growing in solid medium. (author)

The self-crosslinking smart hyaluronic acid hydrogels as injectable three-dimensional scaffolds for cells culture.

Science.gov (United States)

Bian, Shaoquan; He, Mengmeng; Sui, Junhui; Cai, Hanxu; Sun, Yong; Liang, Jie; Fan, Yujiang; Zhang, Xingdong

2016-04-01

Although the disulfide bond crosslinked hyaluronic acid hydrogels have been reported by many research groups, the major researches were focused on effectively forming hydrogels. However, few researchers paid attention to the potential significance of controlling the hydrogel formation and degradation, improving biocompatibility, reducing the toxicity of exogenous and providing convenience to the clinical operations later on. In this research, the novel controllable self-crosslinking smart hydrogels with in-situ gelation property was prepared by a single component, the thiolated hyaluronic acid derivative (HA-SH), and applied as a three-dimensional scaffold to mimic native extracellular matrix (ECM) for the culture of fibroblasts cells (L929) and chondrocytes. A series of HA-SH hydrogels were prepared depending on different degrees of thiol substitution (ranging from 10 to 60%) and molecule weights of HA (0.1, 0.3 and 1.0 MDa). The gelation time, swelling property and smart degradation behavior of HA-SH hydrogel were evaluated. The results showed that the gelation and degradation time of hydrogels could be controlled by adjusting the component of HA-SH polymers. The storage modulus of HA-SH hydrogels obtained by dynamic modulus analysis (DMA) could be up to 44.6 kPa. In addition, HA-SH hydrogels were investigated as a three-dimensional scaffold for the culture of fibroblasts cells (L929) and chondrocytes cells in vitro and as an injectable hydrogel for delivering chondrocytes cells in vivo. These results illustrated that HA-SH hydrogels with controllable gelation process, intelligent degradation behavior, excellent biocompatibility and convenient operational characteristics supplied potential clinical application capacity for tissue engineering and regenerative medicine. Copyright © 2016 Elsevier B.V. All rights reserved.

Asymptotics for Two-dimensional Atoms

DEFF Research Database (Denmark)

Nam, Phan Thanh; Portmann, Fabian; Solovej, Jan Philip

2012-01-01

We prove that the ground state energy of an atom confined to two dimensions with an infinitely heavy nucleus of charge $Z>0$ and $N$ quantum electrons of charge -1 is $E(N,Z)=-{1/2}Z^2\\ln Z+(E^{\\TF}(\\lambda)+{1/2}c^{\\rm H})Z^2+o(Z^2)$ when $Z\\to \\infty$ and $N/Z\\to \\lambda$, where $E^{\\TF}(\\lambd......We prove that the ground state energy of an atom confined to two dimensions with an infinitely heavy nucleus of charge $Z>0$ and $N$ quantum electrons of charge -1 is $E(N,Z)=-{1/2}Z^2\\ln Z+(E^{\\TF}(\\lambda)+{1/2}c^{\\rm H})Z^2+o(Z^2)$ when $Z\\to \\infty$ and $N/Z\\to \\lambda$, where $E......^{\\TF}(\\lambda)$ is given by a Thomas-Fermi type variational problem and $c^{\\rm H}\\approx -2.2339$ is an explicit constant. We also show that the radius of a two-dimensional neutral atom is unbounded when $Z\\to \\infty$, which is contrary to the expected behavior of three-dimensional atoms....

Effects of Apollo 12 lunar material on lipid levels of tobacco tissue and slash pine cultures

Science.gov (United States)

Weete, J. D.

1972-01-01

Investigations of the lipid components of pine tissues (Pinus elloitii) are discussed, emphasizing fatty acids and steroids. The response by slash pine tissue cultures to growth in contact with Apollo lunar soil, earth basalt, and Iowa soil is studied. Tissue cultures of tobacco grown for 12 weeks in contact with lunar material from Apollo 12 flight contained 21 to 35 percent more total pigment than control tissues. No differences were noted in the fresh or dry weight of the experimental and control samples.

Tissue Fractions of Cadmium in Two Hyperaccumulating Jerusalem Artichoke Genotypes

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Xiaohua Long

2014-01-01

Full Text Available In order to investigate the mechanisms in two Jerusalem artichoke (Helianthus tuberosus L. genotypes that hyperaccumulate Cd, a sand-culture experiment was carried out to characterize fractionation of Cd in tissue of Cd-hyperaccumulating genotypes NY2 and NY5. The sequential extractants were: 80% v/v ethanol (FE, deionized water (FW, 1 M NaCl (FNaCl, 2% v/v acetic acid (FAcet, and 0.6 M HCl (FHCl. After 20 days of treatments, NY5 had greater plant biomass and greater Cd accumulation in tissues than NY2. In both genotypes the FNaCl fraction was the highest in roots and stems, whereas the FAcet and FHCl fractions were the highest in leaves. With an increase in Cd concentration in the culture solution, the content of every Cd fraction also increased. The FW and FNaCl ratios in roots were lower in NY5 than in NY2, while the amount of other Cd forms was higher. It implied that, in high accumulator, namely, NY5, the complex of insoluble phosphate tends to be shaped more easily which was much better for Cd accumulation. Besides, translocation from plasma to vacuole after combination with protein may be one of the main mechanisms in Cd-accumulator Jerusalem artichoke genotypes.

Cell-free DNA in a three-dimensional spheroid cell culture model

DEFF Research Database (Denmark)

Aucamp, Janine; Calitz, Carlemi; Bronkhorst, Abel J.

2017-01-01

Background Investigating the biological functions of cell-free DNA (cfDNA) is limited by the interference of vast numbers of putative sources and causes of DNA release into circulation. Utilization of three-dimensional (3D) spheroid cell cultures, models with characteristics closer to the in vivo...... cultures can serve as effective, simplified in vivo-simulating “closed-circuit” models since putative sources of cfDNA are limited to only the targeted cells. In addition, cfDNA can also serve as an alternative or auxiliary marker for tracking spheroid growth, development and culture stability. Biological...... significance 3D cell cultures can be used to translate “closed-circuit” in vitro model research into data that is relevant for in vivo studies and clinical applications. In turn, the utilization of cfDNA during 3D culture research can optimize sample collection without affecting the stability of the growth...

Chemical evaluation of strawberry plants produced by tissue culturing of gamma irradiated seedlings

International Nuclear Information System (INIS)

Maraei, R.W.

2007-01-01

studies were conducted to evaluate the influence of gamma irradiation as a supplementary factor precedes tissue culture application on strawberry seedlings (c.v.Rosa Linda). the strawberry seedling were irradiated using 8 doses of co 60 gamma rays 50.75.100.125 ,150,250, 350 and 500 gray. tissue culture technique was applied on irradiated and unirradiated strawberry seedling. different characteristics of plantlets, plant and fruit of strawberry produced from the double treatment (irradiation followed by tissue culture) were studied as well as the early, total and exportable fruit yields. data indicated that, low radiation doses 50,75 and 100 gray increased all morphological and chemical characteristics of the plantlets, plant and fruit of strawberry, whereas radiation doses higher than 100 gray decreased them significantly. moreover 350 and gray were lethal doses. radiation dose 50 gray increased the survival percentage and the length of plantlets by 1.5% and 50% respectively more than the unirradiated treatment in all multiplication stages

Studies on the reaction in tissue culture of tomato genotypes under biotic stress

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Ewa Hanus-Fajerska

2014-01-01

Full Text Available Plant regeneration in vitro from virus-infected somatic tomato (Lycopersicon sp. tissue was performed. Regeneration experiments were started after the determination of virus presence, using enzyme-linked immunosorbent assay, in leaves used as a source of explants. Leaf explants infected with selected strains of tomato mosaic Tobamovirus or cucumber mosaic Cucumovirus respectively, were cultured on a standarised MS agar medium to induce adventitious shoots, which were afterwards excised, rooted in vitro and cultured to plants. Explants were also screened for their ability to produce callus. Diverse effects of viral infection, ranging from stimulation to inhibition of callus formation and of morphogenesis rate, were observed. The health condition of the tissue proved to affect regeneration potential of Lycopersicon esculentum, whereas wild accesions did not react in that case so distinctly. In cultivated tomato was encountered the decline in competence to reproduce shoots adventitiously in infected tissue. There was also relationship between donor plant health condition and adventitious root formation in regenerated shoots. Experiments with short-term cultures of L. esculenum reveled also that a certain number of shoots regenerated from diseased tissue can be virus-free.

Simple and high yielding method for preparing tissue specific extracellular matrix coatings for cell culture.

Science.gov (United States)

DeQuach, Jessica A; Mezzano, Valeria; Miglani, Amar; Lange, Stephan; Keller, Gordon M; Sheikh, Farah; Christman, Karen L

2010-09-27

The native extracellular matrix (ECM) consists of a highly complex, tissue-specific network of proteins and polysaccharides, which help regulate many cellular functions. Despite the complex nature of the ECM, in vitro cell-based studies traditionally assess cell behavior on single ECM component substrates, which do not adequately mimic the in vivo extracellular milieu. We present a simple approach for developing naturally derived ECM coatings for cell culture that provide important tissue-specific cues unlike traditional cell culture coatings, thereby enabling the maturation of committed C2C12 skeletal myoblast progenitors and human embryonic stem cells differentiated into cardiomyocytes. Here we show that natural muscle-specific coatings can (i) be derived from decellularized, solubilized adult porcine muscle, (ii) contain a complex mixture of ECM components including polysaccharides, (iii) adsorb onto tissue culture plastic and (iv) promote cell maturation of committed muscle progenitor and stem cells. This versatile method can create tissue-specific ECM coatings, which offer a promising platform for cell culture to more closely mimic the mature in vivo ECM microenvironment.

Culture of equine fibroblast-like synoviocytes on synthetic tissue scaffolds towards meniscal tissue engineering: a preliminary cell-seeding study

Directory of Open Access Journals (Sweden)

Jennifer J. Warnock

2014-04-01

Full Text Available Introduction. Tissue engineering is a new methodology for addressing meniscal injury or loss. Synovium may be an ideal source of cells for in vitro meniscal fibrocartilage formation, however, favorable in vitro culture conditions for synovium must be established in order to achieve this goal. The objective of this study was to determine cellularity, cell distribution, and extracellular matrix (ECM formation of equine fibroblast-like synoviocytes (FLS cultured on synthetic scaffolds, for potential application in synovium-based meniscal tissue engineering. Scaffolds included open-cell poly-L-lactic acid (OPLA sponges and polyglycolic acid (PGA scaffolds cultured in static and dynamic culture conditions, and PGA scaffolds coated in poly-L-lactic (PLLA in dynamic culture conditions.Materials and Methods. Equine FLS were seeded on OPLA and PGA scaffolds, and cultured in a static environment or in a rotating bioreactor for 12 days. Equine FLS were also seeded on PGA scaffolds coated in 2% or 4% PLLA and cultured in a rotating bioreactor for 14 and 21 days. Three scaffolds from each group were fixed, sectioned and stained with Masson’s Trichrome, Safranin-O, and Hematoxylin and Eosin, and cell numbers and distribution were analyzed using computer image analysis. Three PGA and OPLA scaffolds from each culture condition were also analyzed for extracellular matrix (ECM production via dimethylmethylene blue (sulfated glycosaminoglycan assay and hydroxyproline (collagen assay. PLLA coated PGA scaffolds were analyzed using double stranded DNA quantification as areflection of cellularity and confocal laser microscopy in a fluorescent cell viability assay.Results. The highest cellularity occurred in PGA constructs cultured in a rotating bioreactor, which also had a mean sulfated glycosaminoglycan content of 22.3 µg per scaffold. PGA constructs cultured in static conditions had the lowest cellularity. Cells had difficulty adhering to OPLA and the PLLA

Apollo 12 lunar material - Effects on lipid levels of tobacco tissue cultures.

Science.gov (United States)

Weete, J. D.; Walkinshaw, C. H.; Laseter, J. L.

1972-01-01

Tobacco tissue cultures grown in contact with lunar material from Apollo 12, for a 12-week period, resulted in fluctuations of both the relative and absolute concentrations of endogenous sterols and fatty acids. The experimental tissues contained higher concentrations of sterols than the controls did. The ratio of campesterol to stigmasterol was greater than 1 in control tissues, but less than 1 in the experimental tissues after 3 weeks. High relative concentrations (17.1 to 22.2 per cent) of an unidentified compound or compounds were found only in control tissues that were 3 to 9 weeks of age.

Co-culture with infrapatellar fat pad differentially stimulates proteoglycan synthesis and accumulation in cartilage and meniscus tissues.

Science.gov (United States)

Nishimuta, James F; Bendernagel, Monica F; Levenston, Marc E

2017-09-01

Although osteoarthritis is widely viewed as a disease of the whole joint, relatively few studies have focused on interactions among joint tissues in joint homeostasis and degeneration. In particular, few studies have examined the effects of the infrapatellar fat pad (IFP) on cartilaginous tissues. The aim of this study was to test the hypothesis that co-culture with healthy IFP would induce degradation of cartilage and meniscus tissues. Bovine articular cartilage, meniscus, and IFP were cultured isolated or as cartilage-fat or meniscus-fat co-cultures for up to 14 days. Conditioned media were assayed for sulfated glycosaminoglycan (sGAG) content, nitrite content, and matrix metalloproteinase (MMP) activity, and explants were assayed for sGAG and DNA contents. Co-cultures exhibited increased cumulative sGAG release and sGAG release rates for both cartilage and meniscus, and the cartilage (but not meniscus) exhibited a substantial synergistic effect of co-culture (sGAG release in co-culture was significantly greater than the summed release from isolated cartilage and fat). Fat co-culture did not significantly alter the sGAG content of either cartilage or meniscus explants, indicating that IFP co-culture stimulated net sGAG production by cartilage. Nitrite release was increased relative to isolated tissue controls in co-cultured meniscus, but not the cartilage, with no synergistic effect of co-culture. Interestingly, MMP-2 production was decreased by co-culture for both cartilage and meniscus. This study demonstrates that healthy IFP may modulate joint homeostasis by stimulating sGAG production in cartilage. Counter to our hypothesis, healthy IFP did not promote degradation of either cartilage or meniscus tissues.

Spin dynamics in a two-dimensional quantum gas

DEFF Research Database (Denmark)

Pedersen, Poul Lindholm; Gajdacz, Miroslav; Deuretzbacher, Frank

2014-01-01

We have investigated spin dynamics in a two-dimensional quantum gas. Through spin-changing collisions, two clouds with opposite spin orientations are spontaneously created in a Bose-Einstein condensate. After ballistic expansion, both clouds acquire ring-shaped density distributions with superimp......We have investigated spin dynamics in a two-dimensional quantum gas. Through spin-changing collisions, two clouds with opposite spin orientations are spontaneously created in a Bose-Einstein condensate. After ballistic expansion, both clouds acquire ring-shaped density distributions...

In Vivo-Like Culture Conditions in a Bioreactor Facilitate Improved Tissue Quality in Corneal Storage.

Science.gov (United States)

Schmid, Richard; Tarau, Ioana-Sandra; Rossi, Angela; Leonhardt, Stefan; Schwarz, Thomas; Schuerlein, Sebastian; Lotz, Christian; Hansmann, Jan

2018-01-01

The cornea is the most-transplanted tissue worldwide. However, the availability and quality of grafts are limited due to the current methods of corneal storage. In this study, a dynamic bioreactor system is employed to enable the control of intraocular pressure and the culture at the air-liquid interface. Thereby, in vivo-like storage conditions are achieved. Different media combinations for endothelium and epithelium are tested in standard and dynamic conditions to enhance the viability of the tissue. In contrast to culture conditions used in eye banks, the combination of the bioreactor and biochrom medium 1 allows to preserve the corneal endothelium and the epithelium. Assessment of transparency, swelling, and the trans-epithelial-electrical-resistance (TEER) strengthens the impact of the in vivo-like tissue culture. For example, compared to corneas stored under static conditions, significantly lower optical densities and significantly higher TEER values were measured (p-value <0.05). Furthermore, healing of epithelial defects is enabled in the bioreactor, characterized by re-epithelialization and initiated stromal regeneration. Based on the obtained results, an easy-to-use 3D-printed bioreactor composed of only two parts was derived to translate the technology from the laboratory to the eye banks. This optimized bioreactor facilitates noninvasive microscopic monitoring. The improved storage conditions ameliorate the quality of corneal grafts and the storage time in the eye banks to increase availability and reduce re-grafting. © 2017 The Authors. Biotechnology Journal Published by Wiley-VCH Verlag GmbH & Co. KGaA.

Finite element study of scaffold architecture design and culture conditions for tissue engineering.

Science.gov (United States)

Olivares, Andy L; Marsal, Elia; Planell, Josep A; Lacroix, Damien

2009-10-01

Tissue engineering scaffolds provide temporary mechanical support for tissue regeneration and transfer global mechanical load to mechanical stimuli to cells through its architecture. In this study the interactions between scaffold pore morphology, mechanical stimuli developed at the cell microscopic level, and culture conditions applied at the macroscopic scale are studied on two regular scaffold structures. Gyroid and hexagonal scaffolds of 55% and 70% porosity were modeled in a finite element analysis and were submitted to an inlet fluid flow or compressive strain. A mechanoregulation theory based on scaffold shear strain and fluid shear stress was applied for determining the influence of each structures on the mechanical stimuli on initial conditions. Results indicate that the distribution of shear stress induced by fluid perfusion is very dependent on pore distribution within the scaffold. Gyroid architectures provide a better accessibility of the fluid than hexagonal structures. Based on the mechanoregulation theory, the differentiation process in these structures was more sensitive to inlet fluid flow than axial strain of the scaffold. This study provides a computational approach to determine the mechanical stimuli at the cellular level when cells are cultured in a bioreactor and to relate mechanical stimuli with cell differentiation.

Procedures for two-dimensional electrophoresis of proteins

Energy Technology Data Exchange (ETDEWEB)

Tollaksen, S.L.; Giometti, C.S.

1996-10-01

High-resolution two-dimensional gel electrophoresis (2DE) of proteins, using isoelectric focusing in the first dimension and sodium dodecyl sulfate/polyacrylamide gel electrophoresis (SDS-PAGE) in the second, was first described in 1975. In the 20 years since those publications, numerous modifications of the original method have evolved. The ISO-DALT system of 2DE is a high-throughput approach that has stood the test of time. The problem of casting many isoelectric focusing gels and SDS-PAGE slab gels (up to 20) in a reproducible manner has been solved by the use of the techniques and equipment described in this manual. The ISO-DALT system of two-dimensional gel electrophoresis originated in the late 1970s and has been modified many times to improve its high-resolution, high-throughput capabilities. This report provides the detailed procedures used with the current ISO-DALT system to prepare, run, stain, and photograph two-dimensional gels for protein analysis.

Quantum oscillations in quasi-two-dimensional conductors

CERN Document Server

Galbova, O

2002-01-01

The electronic absorption of sound waves in quasi-two-dimensional conductors in strong magnetic fields, is investigated theoretically. A longitudinal acoustic wave, propagating along the normal n-> to the layer of quasi-two-dimensional conductor (k-> = left brace 0,0,k right brace; u-> = left brace 0,0,u right brace) in magnetic field (B-> = left brace 0, 0, B right brace), is considered. The quasiclassical approach for this geometry is of no interest, due to the absence of interaction between electromagnetic and acoustic waves. The problem is of interest in strong magnetic field when quantization of the charge carriers energy levels takes place. The quantum oscillations in the sound absorption coefficient, as a function of the magnetic field, are theoretically observed. The experimental study of the quantum oscillations in quasi-two-dimensional conductors makes it possible to solve the inverse problem of determining from experimental data the extrema closed sections of the Fermi surface by a plane p sub z = ...

Third sound in one and two dimensional modulated structures

International Nuclear Information System (INIS)

Komuro, T.; Kawashima, H., Shirahama, K.; Kono, K.

1996-01-01

An experimental technique is developed to study acoustic transmission in one and two dimensional modulated structures by employing third sound of a superfluid helium film. In particular, the Penrose lattice, which is a two dimensional quasiperiodic structure, is studied. In two dimensions, the scattering of third sound is weaker than in one dimension. Nevertheless, the authors find that the transmission spectrum in the Penrose lattice, which is a two dimensional prototype of the quasicrystal, is observable if the helium film thickness is chosen around 5 atomic layers. The transmission spectra in the Penrose lattice are explained in terms of dynamical theory of diffraction

Two-dimensional membranes in motion

NARCIS (Netherlands)

Davidovikj, D.

2018-01-01

This thesis revolves around nanomechanical membranes made of suspended two - dimensional materials. Chapters 1-3 give an introduction to the field of 2D-based nanomechanical devices together with an overview of the underlying physics and the measurementtools used in subsequent chapters. The research

Distribution of phospholipase C isozymes in various rat tissues and cultured cells

International Nuclear Information System (INIS)

Suh, P.G.; Ryu, S.H.; Choi, W.C.; Lee, K.Y.; Rhee, S.G.

1987-01-01

Monoclonal antibodies prepared against PLC-I or PLC-II enzyme did not cross-react with the other. Using a pair of antibodies which recognizes 2 different antigenic sites on the same molecule, radioimmunoassays were developed for the quantitation of PLC-I and PLC-II in homogenates of various tissues and cultured cells, prepared by homogenization in a 2 M KCl buffer. The contents of PLC enzymes were measured in 19 rat tissues, in human platelets and in 17 cultured cells. Results indicate that the concentration of PLC-I and PLC-II is very high in brain, PLC-I is localized mainly in brain and partly in seminal vesicles, PLC-II is found in most tissues and cells. PLC-I is highly localized even in brain: 5 different neuroblastoma did not contain PLC-I while 2 glioma and 1 astrocytoma contained significant amounts

Repair of segmental bone defect using Totally Vitalized tissue engineered bone graft by a combined perfusion seeding and culture system.

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Lin Wang

Full Text Available BACKGROUND: The basic strategy to construct tissue engineered bone graft (TEBG is to combine osteoblastic cells with three dimensional (3D scaffold. Based on this strategy, we proposed the "Totally Vitalized TEBG" (TV-TEBG which was characterized by abundant and homogenously distributed cells with enhanced cell proliferation and differentiation and further investigated its biological performance in repairing segmental bone defect. METHODS: In this study, we constructed the TV-TEBG with the combination of customized flow perfusion seeding/culture system and β-tricalcium phosphate (β-TCP scaffold fabricated by Rapid Prototyping (RP technique. We systemically compared three kinds of TEBG constructed by perfusion seeding and perfusion culture (PSPC method, static seeding and perfusion culture (SSPC method, and static seeding and static culture (SSSC method for their in vitro performance and bone defect healing efficacy with a rabbit model. RESULTS: Our study has demonstrated that TEBG constructed by PSPC method exhibited better biological properties with higher daily D-glucose consumption, increased cell proliferation and differentiation, and better cell distribution, indicating the successful construction of TV-TEBG. After implanted into rabbit radius defects for 12 weeks, PSPC group exerted higher X-ray score close to autograft, much greater mechanical property evidenced by the biomechanical testing and significantly higher new bone formation as shown by histological analysis compared with the other two groups, and eventually obtained favorable healing efficacy of the segmental bone defect that was the closest to autograft transplantation. CONCLUSION: This study demonstrated the feasibility of TV-TEBG construction with combination of perfusion seeding, perfusion culture and RP technique which exerted excellent biological properties. The application of TV-TEBG may become a preferred candidate for segmental bone defect repair in orthopedic and

Injectable Shape-Memorizing Three-Dimensional Hyaluronic Acid Cryogels for Skin Sculpting and Soft Tissue Reconstruction

Science.gov (United States)

Cheng, Liying; Ji, Kai; Shih, Ting-Yu; Haddad, Anthony; Giatsidis, Giorgio; Mooney, David J.; Orgill, Dennis P.

2017-01-01

Introduction: Hyaluronic acid (HA)-based fillers are used for various cosmetic procedures. However, due to filler migration and degradation, reinjections of the fillers are often required. Methacrylated HA (MA-HA) can be made into injectable shape-memorizing fillers (three-dimensional [3D] MA-HA) aimed to address these issues. In this study, shape retention, firmness, and biocompatibility of 3D MA-HA injected subcutaneously in mice were evaluated. Materials and Methods: Fifteen mice, each receiving two subcutaneous injections in their back, were divided into four groups receiving HA, MA-HA, 3D MA-HA, or saline, respectively. Digital imaging, scanning electron microscope (SEM) and in vivo imaging system (IVIS), durometry, and histology were utilized to evaluate in vitro/vivo degradation and migration, material firmness, and the angiogenic (CD31) and immunogenic (CD45) response of the host tissue toward the injected materials. Results: Digital imaging, SEM, and IVIS revealed that 3D MA-HA fillers maintained their predetermined shape for at least 30 days in vitro and in vivo. Little volume effects were noted in the saline and other control groups. There were no differences in skin firmness between the groups or over time. Histology showed intact skin architecture in all groups. Three-dimensional MA-HA maintained its macroporous structure with significant angiogenesis at the 3D MA-HA/skin interfaces and throughout the 3D MA-HA. There was no significant inflammatory response to any of the injected materials. Conclusion: 3D MA-HA showed remarkable tissue compatibility, compliance, and shape predictability, as well as retention, and thus might be suitable for various skin sculpting and soft tissue reconstruction purposes. PMID:27875939

Incorrectness of conventional one-dimensional parallel thermal resistance circuit model for two-dimensional circular composite pipes

International Nuclear Information System (INIS)

Wong, K.-L.; Hsien, T.-L.; Chen, W.-L.; Yu, S.-J.

2008-01-01

This study is to prove that two-dimensional steady state heat transfer problems of composite circular pipes cannot be appropriately solved by the conventional one-dimensional parallel thermal resistance circuits (PTRC) model because its interface temperatures are not unique. Thus, the PTRC model is definitely different from its conventional recognized analogy, parallel electrical resistance circuits (PERC) model, which has unique node electric voltages. Two typical composite circular pipe examples are solved by CFD software, and the numerical results are compared with those obtained by the PTRC model. This shows that the PTRC model generates large error. Thus, this conventional model, introduced in most heat transfer text books, cannot be applied to two-dimensional composite circular pipes. On the contrary, an alternative one-dimensional separately series thermal resistance circuit (SSTRC) model is proposed and applied to a two-dimensional composite circular pipe with isothermal boundaries, and acceptable results are returned

Glioma tissue obtained by modern ultrasonic aspiration with a simple sterile suction trap for primary cell culture and pathological evaluation.

Science.gov (United States)

Schroeteler, Juliane; Reeker, Ralf; Suero Molina, Eric; Brokinkel, Benjamin; Holling, Markus; Grauer, Oliver M; Senner, Volker; Stummer, Walter; Ewelt, Christian

2014-01-01

Ultrasonic aspiration is widely used in the resection of brain tumors. Nevertheless, tumor tissue fragments obtained by ultrasonic aspiration are usually discarded. In this study, we demonstrate that these fragments are possible sources of material for histopathological study and tissue culture and compare their microscopic features and viability in tissue culture of cavitron ultrasonic surgical aspirator tissue fragments. Brain tumor tissue collected by ultrasonic aspiration (CUSA EXcel®; Integra Radionics Inc.) in a simple sterile suction trap during resection was processed for primary cell culture. Cell viability and immunohistological markers were measured by the WST-1 test, microscopy and immunofluorescent evaluation. Six gliomas are presented to demonstrate that these tissue fragments show good preservation of histological detail and tissue viability in culture. Utilization of this material may facilitate pathological interpretation by providing a more representative sample of tumor histology as well as an adequate and sterile biosource of material for tissue culture studies.

Effects of chitosan-coated fibers as a scaffold for three-dimensional cultures of rabbit fibroblasts for ligament tissue engineering.

Science.gov (United States)

Sarukawa, Junichiro; Takahashi, Masaaki; Abe, Masashi; Suzuki, Daisuke; Tokura, Seiichi; Furuike, Tetsuya; Tamura, Hiroshi

2011-01-01

Material selection in tissue-engineering scaffolds is one of the primary factors defining cellular response and matrix formation. In this study, we fabricated chitosan-coated poly(lactic acid) (PLA) fiber scaffolds to test our hypothesis that PLA fibers coated with chitosan highly promoted cell supporting properties compared to those without chitosan. Both PLA fibers (PLA group) and chitosan-coated PLA fibers (PLA-chitosan group) were fabricated for this study. Anterior cruciate ligament (ACL) fibroblasts were isolated from Japanese white rabbits and cultured on scaffolds consisting of each type of fiber. The effects of cell adhesivity, proliferation, and synthesis of the extracellular matrix (ECM) for each fiber were analyzed by cell counting, hydroxyproline assay, scanning electron microscopy and quantitative RT-PCR. Cell adhesivity, proliferation, hydroxyproline content and the expression of type-I collagen mRNA were significantly higher in the PLA-chitosan group than in the PLA group. Scanning electron microscopic observation showed that fibroblasts proliferated with a high level of ECM synthesis around the cells. Chitosan coating improved ACL fibroblast adhesion and proliferation, and had a positive effect on matrix production. Thus, the advantages of chitosan-coated PLA fibers show them to be a suitable biomaterial for ACL tissue-engineering scaffolds.

Chiral anomaly, fermionic determinant and two dimensional models

International Nuclear Information System (INIS)

Rego Monteiro, M.A. do.

1985-01-01

The chiral anomaly in random pair dimension is analysed. This anomaly is perturbatively calculated by dimensional regularization method. A new method for non-perturbative Jacobian calculation of a general chiral transformation, 1.e., finite and non-Abelian, is developed. This method is used for non-perturbative chiral anomaly calculation, as an alternative to bosonization of two-dimensional theories for massless fermions and to study the phenomenum of fermion number fractionalization. The fermionic determinant from two-dimensional quantum chromodynamics is also studied, and calculated, exactly, as in decoupling gauge as with out reference to a particular gauge. (M.C.K.) [pt

A two-dimensional Zn coordination polymer with a three-dimensional supramolecular architecture

Directory of Open Access Journals (Sweden)

Fuhong Liu

2017-10-01

Full Text Available The title compound, poly[bis{μ2-4,4′-bis[(1,2,4-triazol-1-ylmethyl]biphenyl-κ2N4:N4′}bis(nitrato-κOzinc(II], [Zn(NO32(C18H16N62]n, is a two-dimensional zinc coordination polymer constructed from 4,4′-bis[(1H-1,2,4-triazol-1-ylmethyl]-1,1′-biphenyl units. It was synthesized and characterized by elemental analysis and single-crystal X-ray diffraction. The ZnII cation is located on an inversion centre and is coordinated by two O atoms from two symmetry-related nitrate groups and four N atoms from four symmetry-related 4,4′-bis[(1H-1,2,4-triazol-1-ylmethyl]-1,1′-biphenyl ligands, forming a distorted octahedral {ZnN4O2} coordination geometry. The linear 4,4′-bis[(1H-1,2,4-triazol-1-ylmethyl]-1,1′-biphenyl ligand links two ZnII cations, generating two-dimensional layers parallel to the crystallographic (132 plane. The parallel layers are connected by C—H...O, C—H...N, C—H...π and π–π stacking interactions, resulting in a three-dimensional supramolecular architecture.

Review on patents for mechanical stimulation of articular cartilage tissue engineering

NARCIS (Netherlands)

Donkelaar, van C.C.; Schulz, R.M.

2008-01-01

To repair articular cartilage defects in osteoarthritic patients with three-dimensional tissue engineered chondrocyte grafts, requires the formation of new cartilage with sufficient mechanical properties. The premise is that mechanical stimulation during the culturing process is necessary to reach

How-To-Do-It: Using Cauliflower to Demonstrate Plant Tissue Culture.

Science.gov (United States)

Haldeman, Janice H.; Ellis, Jane P.

1988-01-01

Presents techniques used for disinfestation of plant material, preparation of equipment and media, and laboratory procedures for tissue culture using cauliflower. Details methods for preparing solutions and plant propagation by cloning. (CW)

Velocity and Dispersion for a Two-Dimensional Random Walk

International Nuclear Information System (INIS)

Li Jinghui

2009-01-01

In the paper, we consider the transport of a two-dimensional random walk. The velocity and the dispersion of this two-dimensional random walk are derived. It mainly show that: (i) by controlling the values of the transition rates, the direction of the random walk can be reversed; (ii) for some suitably selected transition rates, our two-dimensional random walk can be efficient in comparison with the one-dimensional random walk. Our work is motivated in part by the challenge to explain the unidirectional transport of motor proteins. When the motor proteins move at the turn points of their tracks (i.e., the cytoskeleton filaments and the DNA molecular tubes), some of our results in this paper can be used to deal with the problem. (general)

Theory of the one- and two-dimensional electron gas

International Nuclear Information System (INIS)

Emery, V.J.

1987-01-01

Two topics are discussed: (1) the competition between 2k/sub F/ and 4k/sub F/ charge state waves in a one-dimensional electron gas and (2) a two-dimensional model of high T/sub c/ superconductivity in the oxides

Design of biomimetic cellular scaffolds for co-culture system and their application

Science.gov (United States)

Kook, Yun-Min; Jeong, Yoon; Lee, Kangwon; Koh, Won-Gun

2017-01-01

The extracellular matrix of most natural tissues comprises various types of cells, including fibroblasts, stem cells, and endothelial cells, which communicate with each other directly or indirectly to regulate matrix production and cell functionality. To engineer multicellular interactions in vitro, co-culture systems have achieved tremendous success achieving a more realistic microenvironment of in vivo metabolism than monoculture system in the past several decades. Recently, the fields of tissue engineering and regenerative medicine have primarily focused on three-dimensional co-culture systems using cellular scaffolds, because of their physical and biological relevance to the extracellular matrix of actual tissues. This review discusses several materials and methods to create co-culture systems, including hydrogels, electrospun fibers, microfluidic devices, and patterning for biomimetic co-culture system and their applications for specific tissue regeneration. Consequently, we believe that culture systems with appropriate physical and biochemical properties should be developed, and direct or indirect cell–cell interactions in the remodeled tissue must be considered to obtain an optimal tissue-specific microenvironment. PMID:29081966

The inaccuracy of conventional one-dimensional parallel thermal resistance circuit model for two-dimensional composite walls

International Nuclear Information System (INIS)

Wong, K.-L.; Hsien, T.-L.; Hsiao, M.-C.; Chen, W.-L.; Lin, K.-C.

2008-01-01

This investigation is to show that two-dimensional steady state heat transfer problems of composite walls should not be solved by the conventionally one-dimensional parallel thermal resistance circuits (PTRC) model because the interface temperatures are not unique. Thus PTRC model cannot be used like its conventional recognized analogy, parallel electrical resistance circuits (PERC) model which has the unique node electric voltage. Two typical composite wall examples, solved by CFD software, are used to demonstrate the incorrectness. The numerical results are compared with those obtained by PTRC model, and very large differences are observed between their results. This proves that the application of conventional heat transfer PTRC model to two-dimensional composite walls, introduced in most heat transfer text book, is totally incorrect. An alternative one-dimensional separately series thermal resistance circuit (SSTRC) model is proposed and applied to the two-dimensional composite walls with isothermal boundaries. Results with acceptable accuracy can be obtained by the new model

Improving Cardiac Action Potential Measurements: 2D and 3D Cell Culture.

Science.gov (United States)

Daily, Neil J; Yin, Yue; Kemanli, Pinar; Ip, Brian; Wakatsuki, Tetsuro

2015-11-01

Progress in the development of assays for measuring cardiac action potential is crucial for the discovery of drugs for treating cardiac disease and assessing cardiotoxicity. Recently, high-throughput methods for assessing action potential using induced pluripotent stem cell (iPSC) derived cardiomyocytes in both two-dimensional monolayer cultures and three-dimensional tissues have been developed. We describe an improved method for assessing cardiac action potential using an ultra-fast cost-effective plate reader with commercially available dyes. Our methods improve dramatically the detection of the fluorescence signal from these dyes and make way for the development of more high-throughput methods for cardiac drug discovery and cardiotoxicity.

Two-dimensional fourier transform spectrometer

Science.gov (United States)

DeFlores, Lauren; Tokmakoff, Andrei

2013-09-03

The present invention relates to a system and methods for acquiring two-dimensional Fourier transform (2D FT) spectra. Overlap of a collinear pulse pair and probe induce a molecular response which is collected by spectral dispersion of the signal modulated probe beam. Simultaneous collection of the molecular response, pulse timing and characteristics permit real time phasing and rapid acquisition of spectra. Full spectra are acquired as a function of pulse pair timings and numerically transformed to achieve the full frequency-frequency spectrum. This method demonstrates the ability to acquire information on molecular dynamics, couplings and structure in a simple apparatus. Multi-dimensional methods can be used for diagnostic and analytical measurements in the biological, biomedical, and chemical fields.

Topological aspect of disclinations in two-dimensional crystals

International Nuclear Information System (INIS)

Wei-Kai, Qi; Tao, Zhu; Yong, Chen; Ji-Rong, Ren

2009-01-01

By using topological current theory, this paper studies the inner topological structure of disclinations during the melting of two-dimensional systems. From two-dimensional elasticity theory, it finds that there are topological currents for topological defects in homogeneous equation. The evolution of disclinations is studied, and the branch conditions for generating, annihilating, crossing, splitting and merging of disclinations are given. (the physics of elementary particles and fields)

Two-dimensional ranking of Wikipedia articles

Science.gov (United States)

Zhirov, A. O.; Zhirov, O. V.; Shepelyansky, D. L.

2010-10-01

The Library of Babel, described by Jorge Luis Borges, stores an enormous amount of information. The Library exists ab aeterno. Wikipedia, a free online encyclopaedia, becomes a modern analogue of such a Library. Information retrieval and ranking of Wikipedia articles become the challenge of modern society. While PageRank highlights very well known nodes with many ingoing links, CheiRank highlights very communicative nodes with many outgoing links. In this way the ranking becomes two-dimensional. Using CheiRank and PageRank we analyze the properties of two-dimensional ranking of all Wikipedia English articles and show that it gives their reliable classification with rich and nontrivial features. Detailed studies are done for countries, universities, personalities, physicists, chess players, Dow-Jones companies and other categories.

Fabrication of three-dimensional porous cell-laden hydrogel for tissue engineering

International Nuclear Information System (INIS)

Hwang, Chang Mo; Sant, Shilpa; Masaeli, Mahdokht; Kachouie, Nezamoddin N; Zamanian, Behnam; Khademhosseini, Ali; Lee, Sang-Hoon

2010-01-01

For tissue engineering applications, scaffolds should be porous to enable rapid nutrient and oxygen transfer while providing a three-dimensional (3D) microenvironment for the encapsulated cells. This dual characteristic can be achieved by fabrication of porous hydrogels that contain encapsulated cells. In this work, we developed a simple method that allows cell encapsulation and pore generation inside alginate hydrogels simultaneously. Gelatin beads of 150-300 μm diameter were used as a sacrificial porogen for generating pores within cell-laden hydrogels. Gelation of gelatin at low temperature (4 0 C) was used to form beads without chemical crosslinking and their subsequent dissolution after cell encapsulation led to generation of pores within cell-laden hydrogels. The pore size and porosity of the scaffolds were controlled by the gelatin bead size and their volume ratio, respectively. Fabricated hydrogels were characterized for their internal microarchitecture, mechanical properties and permeability. Hydrogels exhibited a high degree of porosity with increasing gelatin bead content in contrast to nonporous alginate hydrogel. Furthermore, permeability increased by two to three orders while compressive modulus decreased with increasing porosity of the scaffolds. Application of these scaffolds for tissue engineering was tested by encapsulation of hepatocarcinoma cell line (HepG2). All the scaffolds showed similar cell viability; however, cell proliferation was enhanced under porous conditions. Furthermore, porous alginate hydrogels resulted in formation of larger spheroids and higher albumin secretion compared to nonporous conditions. These data suggest that porous alginate hydrogels may have provided a better environment for cell proliferation and albumin production. This may be due to the enhanced mass transfer of nutrients, oxygen and waste removal, which is potentially beneficial for tissue engineering and regenerative medicine applications.

Prevention of pink-pigmented methylotrophic bacteria (Methylohacterium mesophilicum) contamination of plant tissue cultures.

Science.gov (United States)

Chanprame, S; Todd, J J; Widholm, J M

1996-12-01

Pink-pigmented facultative methylotrophic bacteria (PPFMs) have been found on the surfaces of leaves of most plants tested. We found PPFMs on the leaf surfaces of all 40 plants (38 species) tested and on soybean pods by pressing onto AMS medium with methanol as the sole carbon source. The abundance ranged from 0.5 colony forming unit (cfu) /cm(2) to 69.4 cfu/cm(2) on the leaf surfaces. PPFMs were found in homogenized leaf tissues of only 4 of the species after surface disinfestation with 1.05% sodium hypochlorite and were rarely found in cultures initiated from surface disinfested Datura innoxia leaves or inside surface disinfested soybean pods. Of 20 antibiotics tested for PPFM growth inhibition, rifampicin was the most effective and of seven others which also inhibited PPFM growth, cefotaxime should be the most useful due to the expected low plant cell toxicity. These antibiotics could be used in concert with common surface sterilization procedures to prevent the introduction or to eliminate PPFM bacteria in tissue cultures. Thus, while PPFMs are present on the surfaces of most plant tissues, surface disinfestation alone can effectively remove them so that uncontaminated tissue cultures can be initiated in most cases.

Migration ability and Toll-like receptor expression of human mesenchymal stem cells improves significantly after three-dimensional culture.

Science.gov (United States)

Zhou, Panpan; Liu, Zilin; Li, Xue; Zhang, Bing; Wang, Xiaoyuan; Lan, Jing; Shi, Qing; Li, Dong; Ju, Xiuli

2017-09-16

While the conventional two-dimensional (2D) culture protocol is well accepted for the culture of mesenchymal stem cells (MSCs), this method fails to recapitulate the in vivo native three-dimensional (3D) cellular microenvironment, and may result in phenotypic changes, and homing and migration capacity impairments. MSC preparation in 3D culture systems has been considered an attractive preparatory and delivery method recently. We seeded human umbilical cord-derived MSCs (hUCMSCs) in a 3D culture system with porcine acellular dermal matrix (PADM), and investigated the phenotypic changes, the expression changes of some important receptors, including Toll-like receptors (TLRs) and C-X-C chemokine receptor type 4 (CXCR4) when hUCMSCs were transferred from 2D to 3D systems, as well as the alterations in in vivo homing and migration potential. It was found that the percentage of CD105-positive cells decreased significantly, whereas that of CD34- and CD271-positive cells increased significantly in 3D culture, compared to that in 2D culture. The mRNA and protein expression levels of TLR2, TLR3, TLR4, TLR6, and CXCR4 in hUCMSCs were increased significantly upon culturing with PADM for 3 days, compared to the levels in 2D culture. The numbers of migratory 3D hUCMSCs in the heart, liver, spleen, and bone marrow were significantly greater than the numbers of 2D hUCMSCs, and the worst migration occurred in 3D + AMD3100 (CXCR4 antagonist) hUCMSCs. These results suggested that 3D culture of hUCMSCs with PADM could alter the phenotypic characteristics of hUCMSCs, increase their TLR and CXCR4 expression levels, and promote their migratory and homing capacity in which CXCR4 plays an important role. Copyright © 2017 Elsevier Inc. All rights reserved.