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1

Plant Cell Cultures in Space Biology Studies.  

National Technical Information Service (NTIS)

The rate of cell wall regeneration using rape protoplasts was studied in preparatory experiments for the Spacelab Biorack IML-1 mission. Under normal ground conditions the cell wall regenerates during the first 24 hr. Results from experiments using low te...

T. Iversen C. Baggerud K. Draget

1987-01-01

2

Human preleukaemia cell culture studies in sideroblastic anaemia.  

PubMed Central

Cell structure abnormalties are found in acute leukaemia and preleukaemic states. Studies on bone marrow cells and peripheral leucocytes of 4 patients with idiopathic acquired sideroblastic anaemia showed patterns in cell culture similar to those reported in acute leukaemia: 2 of these patients later developed leukaemia. Other patients with idiopathic, secondary or congenital sideroblastosis showed no such cell culture abnormalities, and none developed leukaemia. Studies such as this suggest that cell culture methods detect altered cellular function preceding overt leukaemia and that these abnormal findings may be helpful in the evaluation of patient groups with an increased incidence of leukaemia.

Senn, J. S.; Pinkerton, P. H.; Price, G. B.; Mak, T. W.; McCulloch, E. A.

1976-01-01

3

Studies on Addiction and Withdrawal in Cell Cultures.  

National Technical Information Service (NTIS)

The objectives were to determine if cell cultures of neuronal and/or nonneural cells can be used to study the biochemical changes that occur during long term exposure of cells to drugs which become addictive and from which withdrawal reactions occur. The ...

F. R. Leach M. L. Higgins

1973-01-01

4

Sex stratified neuronal cultures to study ischemic cell death pathways.  

PubMed

Sex differences in neuronal susceptibility to ischemic injury and neurodegenerative disease have long been observed, but the signaling mechanisms responsible for those differences remain unclear. Primary disassociated embryonic neuronal culture provides a simplified experimental model with which to investigate the neuronal cell signaling involved in cell death as a result of ischemia or disease; however, most neuronal cultures used in research today are mixed sex. Researchers can and do test the effects of sex steroid treatment in mixed sex neuronal cultures in models of neuronal injury and disease, but accumulating evidence suggests that the female brain responds to androgens, estrogens, and progesterone differently than the male brain. Furthermore, neonate male and female rodents respond differently to ischemic injury, with males experiencing greater injury following cerebral ischemia than females. Thus, mixed sex neuronal cultures might obscure and confound the experimental results; important information might be missed. For this reason, the Herson Lab at the University of Colorado School of Medicine routinely prepares sex-stratified primary disassociated embryonic neuronal cultures from both hippocampus and cortex. Embryos are sexed before harvesting of brain tissue and male and female tissue are disassociated separately, plated separately, and maintained separately. Using this method, the Herson Lab has demonstrated a male-specific role for the ion channel TRPM2 in ischemic cell death. In this manuscript, we share and discuss our protocol for sexing embryonic mice and preparing sex-stratified hippocampal primary disassociated neuron cultures. This method can be adapted to prepare sex-stratified cortical cultures and the method for embryo sexing can be used in conjunction with other protocols for any study in which sex is thought to be an important determinant of outcome. PMID:24378980

Fairbanks, Stacy L; Vest, Rebekah; Verma, Saurabh; Traystman, Richard J; Herson, Paco S

2013-01-01

5

Bovine chromaffin cell cultures as model to study organophosporus neurotoxicity.  

PubMed

Based on the high level of phenyl valerate esterase activities, and in particular of neuropathy target esterase (NTE) found in bovine adrenal medulla, chromaffin cells culture have been proposed as an alternative model for the study of organophosphorus neurotoxicity. Organophosphorus-induced polyneuropathy is a syndrome related to the inhibition and further modification by organophosphorus compounds of NTE (a protein that displays phenyl valerate esterase activity resistant to mipafox and sensitive to paraoxon). Total phenyl valerate esterase activities found in homogenate, particulate and soluble fractions of bovine adrenal medulla were 5200+/-35, 5000+/-280 and 1700+/-260 mU/g tissue, respectively. Cultured chromaffin cells displayed a total hydrolysing activity of 41+/-5 mU/10(6) cells. Homogenates of bovine adrenal medulla displayed only about 6% of activity sensitive to paraoxon. Most of the phenyl valerate esterase activity inhibited by mipafox (a neuropathy inducing compound) was found in particulate fraction. Cultured chromaffin cells displayed kinetics of inhibition by mipafox similar to the kinetics displayed by homogenates of bovine adrenal medulla. We conclude that NTE could be assayed in this system by only using one inhibitor (mipafox) instead of two (paraoxon and mipafox). Also, the proposal is supported of using chromaffin cells as in vitro model for the study of the role of NTE and related esterases in organophosphorus-induced polyneuropathy. PMID:15177651

Quesada, E; Sogorb, M A; Vilanova, E; Carrera, V

2004-06-15

6

Studies on oxygen transfer process in animal cell culture bioreactor.  

PubMed

The oxygen transfer rates were investigated systematically in the CellCul-20A bioreactor with the device of cage aeration in this paper. The temperature, rotating speed, aeration rate and foam breaker, which affected the rate of oxygen transfer were studied, respectively. The mass transfer rate increased significantly with the aeration while the foam breaker had a negative effect on kLa, especially in a cell culture medium with 5% (v/v) calf serum. The oxygen transfer coefficients of surface and deep aerations were correlated, based on the experimental data. PMID:8155835

Wang, S; Chen, Y; Pan, H; Yu, J

1993-01-01

7

Attachment Formation Following Replantation of Cultured Cells into Periodontal Defects—a Study in Minipigs  

Microsoft Academic Search

Regeneration processes in the periodontium occur by the interaction of different cell populations. It is known that these cells are also capable of forming new periodontal tissue after culture in vitro. The present study investigated whether replanted cultured cells from the periodontium could contribute to attachment formation. Primary cell cultures from alveolar bone and periodontal ligament were obtained from 11

H. Lang; N. Schiuler; R. Nolden

1998-01-01

8

Performance of Karyologic Studies on Primary Human Cell Cultures.  

National Technical Information Service (NTIS)

Cells from skin, lung, and kidney biopsies from 6 fetuses were cultured in vitro. Photographs of original cultures and subcultures are on file. One hundred metaphase plates were sketched for each tissue type and of these twenty were karyotyped. Six hundre...

L. Y. F. Hsu

1975-01-01

9

Elicitation studies in cell suspension cultures of Cannabis sativa L.  

PubMed

Cannabis sativa L. plants produce a diverse array of secondary metabolites. Cannabis cell cultures were treated with biotic and abiotic elicitors to evaluate their effect on secondary metabolism. Metabolic profiles analysed by (1)H NMR spectroscopy and principal component analysis (PCA) showed variations in some of the metabolite pools. However, no cannabinoids were found in either control or elicited cannabis cell cultures. Tetrahydrocannabinolic acid (THCA) synthase gene expression was monitored during a time course. Results suggest that other components in the signaling pathway can be controlling the cannabinoid pathway. PMID:19500620

Flores-Sanchez, Isvett Josefina; Pec, Jaroslav; Fei, Junni; Choi, Young Hae; Dusek, Jaroslav; Verpoorte, Robert

2009-08-20

10

Bioconversion studies in cultured cells of Corydalis species.  

PubMed

Structural analysis of the metabolites of dopamine and salsolinol in cultured cells of Corydalis species was carried out using the combination of LC-MS and LC-NMR techniques. Metabolic pathways were clarified without the need to isolate the individual metabolites. PMID:15248465

Iwasa, K; Kuribayashi, A; Sugiura, M; Nishiyama, Y; Ichimaru, M; Moriyasu, M; Lee, D U

2004-06-01

11

Cultivator for NMR studies of suspended cell cultures.  

PubMed

When nuclear magnetic resonance (NMR) spectroscopy is employed for physiological experiments with suspended cells, providing for adequate nutrient and oxygen delivery is particularly important, because the inherent insensitivity of NMR requires that concentrated cell suspensions be used. In addition, it is desirable to be able to manipulate the growth rate of cells during a NMR experiment. To address these concerns, a continuous cell cultivator that provides convective oxygen and nutrient transport has been constructed for NMR experiments. The NMR detector coil is located within the cultivator volume. The location is advantageous because the rapid exchange of cells in and out of the coil leads to a small apparent spin lattice relaxation time, thus allowing for rapid pulsing and fast signal averaging. In this article we present the physical principles on which the cultivator's design is based. (31)P spectra showing the response of continuously cultivated Saccharomyces cerevisiae cultures to a phosphate bolus and growth rate shift are then given. PMID:18601092

Meehan, A J; Eskey, C J; Domach, M M; Koretsky, A P

1992-12-20

12

Advances in microfluidic cell culture systems for studying angiogenesis.  

PubMed

Angiogenesis, the formation of new blood vessels in the vasculature, is a major research topic in biology with implications in development, cancer, tissue engineering, and regenerative medicine. Although much knowledge has been acquired over many decades through application of various angiogenesis assays, these methods have various drawbacks that limit their overall utility. Given the importance of angiogenesis in our understanding of numerous biological processes and its potential as a therapeutic target in cancer and other diseases, there is need to develop useful tools with improved physiological relevance, accessibility, robustness, and throughput over existing assays. Recent developments in microfluidics have demonstrated enormous potential of microscale cell culture systems for biology studies, especially angiogenesis. This area is advancing rapidly, and it is important to remain up to date with the state of the art in technology and evaluate its current and future impact on angiogenesis research. This review examines the latest advances in microfluidic angiogenesis systems. Design and methodology of microscale systems are discussed, and biological insights obtained from the systems are examined. Importantly, physiological relevance, accessibility, and data output of microfluidic angiogenesis systems are compared with traditional angiogenesis assays, and next challenges facing researchers are presented with consideration of the potential integration of automated systems. PMID:23832929

Young, Edmond W K

2013-12-01

13

Epithelial Cell Culture from Human Adenoids: A Functional Study Model for Ciliated and Secretory Cells  

PubMed Central

Background. Mucociliary transport (MCT) is a defense mechanism of the airway. To study the underlying mechanisms of MCT, we have both developed an experimental model of cultures, from human adenoid tissue of ciliated and secretory cells, and characterized the response to local chemical signals that control ciliary activity and the secretion of respiratory mucins in vitro. Materials and Methods. In ciliated cell cultures, ciliary beat frequency (CBF) and intracellular Ca2+ levels were measured in response to ATP, UTP, and adenosine. In secretory cultures, mucin synthesis and secretion were identified by using immunodetection. Mucin content was taken from conditioned medium and analyzed in the presence or absence of UTP. Results. Enriched ciliated cell monolayers and secretory cells were obtained. Ciliated cells showed a basal CBF of 10.7?Hz that increased significantly after exposure to ATP, UTP, or adenosine. Mature secretory cells showed active secretion of granules containing different glycoproteins, including MUC5AC. Conclusion. Culture of ciliated and secretory cells grown from adenoid epithelium is a reproducible and feasible experimental model, in which it is possible to observe ciliary and secretory activities, with a potential use as a model to understand mucociliary transport control mechanisms.

Gonzalez, Claudia; Espinosa, Marisol; Sanchez, Maria Trinidad; Droguett, Karla; Rios, Mariana; Fonseca, Ximena; Villalon, Manuel

2013-01-01

14

Cell isolation and culture.  

PubMed

Cell isolation and culture are essential tools for the study of cell function. Isolated cells grown under controlled conditions can be manipulated and imaged at a level of resolution that is not possible in whole animals or even tissue explants. Recent advances have allowed for large-scale isolation and culture of primary C. elegans cells from both embryos and all four larval stages. Isolated cells can be used for single-cell profiling, electrophysiology, and high-resolution microscopy to assay cell autonomous development and behavior. This chapter describes protocols for the isolation and culture of C. elegans embryonic and larval stage cells. Our protocols describe isolation of embryonic and L1 stage cells from nematodes grown on high-density NA22 bacterial plates and isolation of L2 through L4 stage cells from nematodes grown in axenic liquid culture. Both embryonic and larval cells can be isolated from nematode populations within 3 hours and can be cultured for several days. A primer on sterile cell culture techniques is given in the appendices. PMID:23430760

Zhang, Sihui; Kuhn, Jeffrey R

2013-01-01

15

Biosynthesis of cellulose: studies with tobacco protoplasts and cultured cells  

SciTech Connect

The cell wall of regenerating tobacco protoplasts was shown to be mainly composed of noncellulosic ..beta..-1,3- and ..beta..-1,4-linked glucans with a cellulose content of only about 5%. Some pectic and hemicellulosic material is released by these protoplasts into the culture medium. The DP distribution of the ..cap alpha..-cellulose in regenerating protoplasts as well as in suspension-cultured cells, callus, or tobacco mesophyll revealed the existence of mainly two DP fractions with low (DP<500) and higher (DP 2000-3000) molecular weight, both of which contribute to the cellulosic network of the primary cell wall. The alkali-soluble and alkali-insoluble products of glucan synthetase assays with particulate enzyme fractions were analyzed in detail. By prelabeling with (/sup 14/C)glucose, the existence of primer glucans, which are elongated in the appropriate in vitro assay, could be substantiated. Alkali-soluble glucans consisted of a very short, if any, primer glucan, to which about 40 glucose units were added in vitro. The glucans in the alkali-insoluble fraction have an average DP of 200-250 and are synthesized in vitro by chain elongation via addition of about 30 new glucose units to a 1,4-linked primer glucan of DPapprox.200. 27 references, 6 figures, 2 tables.

Franz, G.; Blaschek, W.; Haass, D.; Koehler, H.

1983-01-01

16

Hepatic parenchymal cell glutamylation of methotrexate studied in monolayer culture.  

PubMed

A detailed analysis of the gamma-glutamylation of methotrexate has been conducted in primary cultures of rat hepatic parenchymal cells in monolayer culture. The rates of glutamylation are concentration dependent and saturable when measured over a 6-h period at concentrations between 2 and 50 microM. The removal of folate and inclusion of insulin, dexamethasone, and tocopherol enhance glutamylation. Omission of methionine from the medium increases glutamylation, whereas the 6-h period of syntheses, methotrexate the reaction. During the 6-h period of syntheses, methotrexate diglutamate is the primary product, whereas the di- and triglutamates are the major cellular species when the incubation is extended to 24 h. Lower extracellular methotrexate concentrations result in the formation of relatively greater amounts of longer chain length derivatives. The accumulation of methotrexate polyglutamates at steady state is saturable and occurs by 24 h. The predominant species contain two to four glutamate residues, and the distribution depends upon the culture conditions and the extracellular methotrexate concentration. The turnover of cellular polyglutamates at saturation occurs at 30 to 40% of the total cell pool over a 6-h period. Placement of hepatocytes with saturating levels of methotrexate polyglutamates in medium lacking methotrexate results in the slow loss of all derivatives, and the rate of loss is inversely related to polyglutamate chain length. Following a pulse dose of methotrexate, hepatocytes continue to increase the chain length of the cellular pool of polyglutamates, and this process is impaired by addition of folinic acid to the medium. In the pulse experiments as in the longer term incubations, the primary species are the di- and triglutamates. The results demonstrate limited capacity of the hepatocytes to glutamylate longer chain length polyglutamate derivatives. PMID:2416430

Galivan, J; Pupons, A; Rhee, M S

1986-02-01

17

The Use of Cultured Epithelial and Endothelial Cells for Drug Transport and Metabolism Studies  

Microsoft Academic Search

In an effort to develop novel strategies for delivery of drug candidates arising from rational drug design and recombinant DNA technology, pharmaceutical scientists have begun to employ the techniques of cell culture to study drug transport and metabolism at specific biological barriers. This review describes some of the general factors that should be considered in developing a cell culture model

Kenneth L. Audus; Ronnda L. Bartel; Ismael J. Hidalgo; Ronald T. Borchardt

1990-01-01

18

Nitric oxide delivery system for cell culture studies.  

PubMed

To investigate the toxicity and mutagenicity of NO, methods are needed to deliver it to cell cultures at known, constant rates. To permit continuous exposures over lengthy periods, we fabricated a simple apparatus utilizing gas-permeable polydimethylsiloxane (Silastic) tubing to supply both NO and O2 to a stirred, cylindrical vessel. Mass transfer in this system was characterized by measuring the delivery rates of NO or O2 alone, and of NO to air-saturated solutions. The concentrations of NO, O2, and NO2- (the end product of NO oxidation) were monitored continuously. The total flux of nitrogen species into the liquid (as determined from the sum of NO and NO2- accumulation) was 50%-90% greater in the presence of O2, depending on the NO partial pressure in the gas. Also, the simultaneously measured mass transfer coefficients for NO and O2 differed greatly from the corresponding unreactive values. An analysis of the data using diffusion-reaction models showed that NO oxidation in the aqueous boundary layer contributed very little to the nitrogen flux increase or to variations in the mass transfer coefficients. However, the unusually strong dependence of the delivery rates on chemical reactions could be explained by postulating that partial oxidation of NO to NO2 occurred within the membrane. The rate constant we estimated for polydimethylsiloxane, 4.4 x 10(5) M-2 s(-1) at 23 degrees C, is only about one-fifth of values reported previously for water and nonpolar solvents, but the high solubilities of NO and O2 in the polymer are sufficient to make NO2 formation significant. Although considerable NO2 is calculated to enter the liquid, its reaction with aqueous NO is rapid enough to keep this undesired compound at trace levels, except within a few microns of the tubing. Thus, cells will have little exposure to NO2 PMID:12572657

Wang, Chen; Deen, William M

2003-01-01

19

Molluscan cells in culture: primary cell cultures and cell lines  

PubMed Central

In vitro cell culture systems from molluscs have significantly contributed to our basic understanding of complex physiological processes occurring within or between tissue-specific cells, yielding information unattainable using intact animal models. In vitro cultures of neuronal cells from gastropods show how simplified cell models can inform our understanding of complex networks in intact organisms. Primary cell cultures from marine and freshwater bivalve and gastropod species are used as biomonitors for environmental contaminants, as models for gene transfer technologies, and for studies of innate immunity and neoplastic disease. Despite efforts to isolate proliferative cell lines from molluscs, the snail Biomphalaria glabrata Say, 1818 embryonic (Bge) cell line is the only existing cell line originating from any molluscan species. Taking an organ systems approach, this review summarizes efforts to establish molluscan cell cultures and describes the varied applications of primary cell cultures in research. Because of the unique status of the Bge cell line, an account is presented of the establishment of this cell line, and of how these cells have contributed to our understanding of snail host-parasite interactions. Finally, we detail the difficulties commonly encountered in efforts to establish cell lines from molluscs and discuss how these difficulties might be overcome.

Yoshino, T. P.; Bickham, U.; Bayne, C. J.

2013-01-01

20

Using the Drosophila melanogaster D17-c3 cell culture system to study cell motility  

Microsoft Academic Search

Cultured Drosophila melanogaster S2 and S2R+ cell lines have become important tools for uncovering fundamental aspects of cell biology as well as for gene discovery. Despite their utility, these cell lines are nonmotile and cannot build polarized structures or cell-cell contacts. Here we outline a previously isolated, but uncharacterized, Drosophila cell line named Dm-D17-c3 (or D17). These cells spread and

Joshua D Currie; Stephen L Rogers

2011-01-01

21

Assessment of cell death studies by monitoring hydrogen peroxide in cell culture.  

PubMed

Hydrogen peroxide (H2O2) has been widely used to study the oxidative stress response. However, H2O2 is unstable and easily decomposes into H2O and O2. Consequently, a wide range of exposure times and treatment concentrations has been described in the literature. In the present study, we established a ferrous oxidation-xylenol orange (FOX) assay, which was originally described for food and body liquids, as a method for the precise quantification of H2O2 concentrations in cell culture media. We observed that the presence of FCS and high cell densities significantly accelerate the decomposition of H2O2, therefore acting as a protection against cell death by accidental necrosis. PMID:24747006

Hirsch, Irina; Prell, Erik; Weiwad, Matthias

2014-07-01

22

Insect neuronal cultures: an experimental vehicle for studies of physiology, pharmacology and cell interactions.  

PubMed

The current status of insect neuronal cultures is discussed and their contribution to our understanding of the insect nervous system is explored. Neuronal cultures have been developed from a wide range of insect species and from all developmental stages. These have been used to study the morphological development of insect neurones and some of the extrinsic factors that affect this process. In addition, they have been used to investigate the physiology of sodium, potassium and calcium channels and the pharmacology of acetylcholine and GABA receptors. Insect neurones have also been grown in culture with muscle and glial cells to study cell interactions. PMID:16874504

Beadle, D J

2006-09-01

23

Biology on a Chip: Microfabrication for Studying the Behavior of Cultured Cells  

PubMed Central

The ability to culture cells in vitro has revolutionized hypothesis testing in basic cell and molecular biology research and has become a standard methodology in drug screening and toxicology assays. However, the traditional cell culture methodology—consisting essentially of the immersion of a large population of cells in a homogeneous fluid medium—has become increasingly limiting, both from a fundamental point of view (cells in vivo are surrounded by complex spatiotemporal microenvironments) and from a practical perspective (scaling up the number of fluid handling steps and cell manipulations for high-throughput studies in vitro is prohibitively expensive). Micro fabrication technologies have enabled researchers to design, with micrometer control, the biochemical composition and topology of the substrate, the medium composition, as well as the type of neighboring cells surrounding the microenvironment of the cell. In addition, microtechnology is conceptually well suited for the development of fast, low-cost in vitro systems that allow for high-throughput culturing and analysis of cells under large numbers of conditions. Here we review a variety of applications of microfabrication in cell culture studies, with an emphasis on the biology of various cell types.

Li, Nianzhen; Tourovskaia, Anna; Folch, Albert

2013-01-01

24

Using the Drosophila melanogaster D17-c3 cell culture system to study cell motility  

PubMed Central

Cultured Drosophila melanogaster S2 and S2R + cell lines have become important tools for uncovering fundamental aspects of cell biology as well as for gene discovery. Despite their utility, these cell lines are nonmotile and cannot build polarized structures or cell-cell contacts. Here we outline a previously isolated, but uncharacterized, Drosophila cell line named Dm-D17-c3 (or D17). These cells spread and migrate in culture, form cell-cell junctions and are susceptible to RNA interference (RNAi). Using this protocol, we describe how investigators, upon receiving cells from the Bloomington stock center, can culture cells and prepare the necessary reagents to plate and image migrating D17 cells; they can then be used to examine intracellular dynamics or observe loss-of-function RNAi phenotypes using an in vitroscratch or wound healing assay. From first thawing frozen ampules of D17 cells, investigators can expect to begin assaying RNAi phenotypes in D17 cells within roughly 2–3 weeks.

Currie, Joshua D; Rogers, Stephen L

2014-01-01

25

Rat Ovarian Granulosa Cell Culture: A Model System for the Study of Cell-Cell Communicationduring Multistep Transformation1  

Microsoft Academic Search

A spontaneously immortalized clonal granulosa cell line (SIGC) de rived from primary rat ovarian granulosa cell cultures was developed as a model system to explore the process of transformation using an epithe lial cell type. SIGC has an epithelial morphology and grows in culture without undergoing luteinization. The cell line is thought to represent an intermediate step in carcinogenesis because

Lisa S. Stein; George Stoica; Roger Tilley; Robert C. Burghardt

1991-01-01

26

Organ Explant Culture of Neonatal Rat Ventricles: A New Model to Study Gene and Cell Therapy  

PubMed Central

Testing cardiac gene and cell therapies in vitro requires a tissue substrate that survives for several days in culture while maintaining its physiological properties. The purpose of this study was to test whether culture of intact cardiac tissue of neonatal rat ventricles (organ explant culture) may be used as a model to study gene and cell therapy. We compared (immuno) histology and electrophysiology of organ explant cultures to both freshly isolated neonatal rat ventricular tissue and monolayers. (Immuno) histologic studies showed that organ explant cultures retained their fiber orientation, and that expression patterns of ?-actinin, connexin-43, and ?-smooth muscle actin did not change during culture. Intracellular voltage recordings showed that spontaneous beating was rare in organ explant cultures (20%) and freshly isolated tissue (17%), but common (82%) in monolayers. Accordingly, resting membrane potential was -83.9±4.4 mV in organ explant cultures, ?80.5±3.5 mV in freshly isolated tissue, and ?60.9±4.3 mV in monolayers. Conduction velocity, measured by optical mapping, was 18.2±1.0 cm/s in organ explant cultures, 18.0±1.2 cm/s in freshly isolated tissue, and 24.3±0.7 cm/s in monolayers. We found no differences in action potential duration (APD) between organ explant cultures and freshly isolated tissue, while APD of monolayers was prolonged (APD at 70% repolarization 88.8±7.8, 79.1±2.9, and 134.0±4.5 ms, respectively). Organ explant cultures and freshly isolated tissue could be paced up to frequencies within the normal range for neonatal rat (CL 150 ms), while monolayers could not. Successful lentiviral (LV) transduction was shown via Egfp gene transfer. Co-culture of organ explant cultures with spontaneously beating cardiomyocytes increased the occurrence of spontaneous beating activity of organ explant cultures to 86%. We conclude that organ explant cultures of neonatal rat ventricle are structurally and electrophysiologically similar to freshly isolated tissue and a suitable new model to study the effects of gene and cell therapy.

den Haan, A. Denise; Veldkamp, Marieke W.; Bakker, Diane; Boink, Geert J. J.; Janssen, Rob B.; de Bakker, Jacques M. T.; Tan, Hanno L.

2013-01-01

27

Studies on Addiction and Withdrawal in Cell Culture.  

National Technical Information Service (NTIS)

After 415 days (70 subcultures) growth in the presence of slowly increased drug concentrations, KB cells with increased tolerance to amphetamine, benadryl, caffeine, codeine, and morphine have developed. No withdrawal symptoms have been observed upon the ...

F. R. Leach M. L. Higgins T. J. Shaw S. Stadnicki

1974-01-01

28

Mechanically and chemically tunable cell culture system for studying the myofibroblast phenotype.  

PubMed

Cell culture systems for studying the combined effects of matrix proteins and mechanical forces on the behavior of soft tissue cells have not been well developed. Here, we describe a new biomimetic cell culture system that allows for the study of mixtures of matrix proteins while controlling mechanical stiffness in a range that is physiological for soft tissues. This system consists of layer-by-layer (LbL)-assembled films of native matrix proteins atop mechanically tunable soft supports. We used hepatic stellate cells, which differentiate to myofibroblasts in liver fibrosis, for proof-of-concept studies. By culturing cells on collagen and lumican LbL-modified hydrogels, we demonstrate that this system is noncytotoxic and offers a valid control substrate, that the hydrogel determines the overall system mechanics, and that the addition of lumican to collagen influences the stellate cell phenotype. LbL-modified hydrogels offer the potential to study the influence of complex environmental factors on soft-tissue cells in culture. PMID:24787894

Saums, Michele K; Wang, Weifeng; Han, Biao; Madhavan, Lakshmi; Han, Lin; Lee, Daeyeon; Wells, Rebecca G

2014-05-20

29

[Studies on canine distemper virus. I. Virus cultivation in cell cultures].  

PubMed

The author studied the multiplication capacity of 2 avianized strains of canine distemper virus - Onderstepoort and Lederle Encephalitis and 2 country strains - WS-66 and LL-68 in primary cell cultures of chicken embryo fibroblasts and the dog's kidney. The strain Onderstepoort multiplied and caused cytopathological changes in the cell culture of chicken embryo fibroblasts after passaging from villousallantoic membranes of chicken embryos. Maximum titer was found between the 5th and 15th passage in the cell culture and amounted to about 10(5.0) TCID50 or about 10(5.5) EID50. In all 50 passages were carried out. However, multiplication occurred, and cytopathological changes in cell culture of chicken embryo fibroblasts were caused by the strain Lederle Encephalitis only due to the application of initial adsorption and maximum inoculum by 8 successive passages. Maximum TCID50 titre occurred after 40 passages and was about 10(4.5). Both strains preserved their ability to evoke changes on villonsallantoic membranes. Studies on the effect of the inoculum size and incubation time on the virus harvest were carried out Lederle Encephalitis strain on the level of 18-20 passages. In the culture of fibroblasts the most favourable results were obtained by using 10(2.0)-10(2.5) TCID50 inoculum per 10(5.0) cells, harvested after about 96 hr of incubation. Attempts to adapt the strains Onderstepoort and Lederle Encephalitis to cell culture of the dog's kidney gave negative results. Multiplication of the country strains of canine distemper WS-66 and LL-68 was not obtained in the cell culture of the dog's kidney and in that of chicken embryo fibroblasts in the experiment conditions. PMID:3822856

Górska, C

1986-01-01

30

Study of efficaciousness of bromelain on mammalian cell culture  

Microsoft Academic Search

Bromelain, a protease enzyme, is found in the stem and fruit of pineapple. It has been used in medical as therapeutic agents and supplements, and also known to have immunomodulatory function. However, as protease, it is concerned that bromelain will affect the mammalian cells that have proteins on their surfaces. The objective of this research was to find out the

Monica Lestari; Maruli Pandjaitan; Joko Pamungkas

2011-01-01

31

Optimizing stem cell culture.  

PubMed

Stem cells always balance between self-renewal and differentiation. Hence, stem cell culture parameters are critical and need to be continuously refined according to progress in our stem cell biology understanding and the latest technological developments. In the past few years, major efforts have been made to define more precisely the medium composition in which stem cells grow or differentiate. This led to the progressive replacement of ill-defined additives such as serum or feeder cell layers by recombinant cytokines or growth factors. Another example is the control of the oxygen pressure. For many years cell cultures have been done under atmospheric oxygen pressure which is much higher than the one experienced by stem cells in vivo. A consequence of cell metabolism is that cell culture conditions are constantly changing. Therefore, the development of high sensitive monitoring processes and control algorithms is required for ensuring cell culture medium homeostasis. Stem cells also sense the physical constraints of their microenvironment. Rigidity, stiffness, and geometry of the culture substrate influence stem cell fate. Hence, nanotopography is probably as important as medium formulation in the optimization of stem cell culture conditions. Recent advances include the development of synthetic bioinformative substrates designed at the micro- and nanoscale level. On going research in many different fields including stem cell biology, nanotechnology, and bioengineering suggest that our current way to culture cells in Petri dish or flasks will soon be outdated as flying across the Atlantic Ocean in the Lindbergh's plane. PMID:20803548

van der Sanden, Boudewijn; Dhobb, Mehdi; Berger, François; Wion, Didier

2010-11-01

32

Optimizing stem cell culture  

PubMed Central

Stem cells always balance between self-renewal and differentiation. Hence, stem cell culture parameters are critical and need to be continuously refined according to progress in our stem cell biology understanding and the latest technological developments. This led to the progressive replacement of ill-defined additives such as serum or feeder cell layers by recombinant cytokines or growth factors. Another example is the control of the oxygen pressure. For many years cell cultures have been done under atmospheric oxygen pressure which is much higher than the one experienced by stem cells in vivo. A consequence of cell metabolism is that cell culture conditions are constantly changing. Therefore, the development of high sensitive monitoring processes and control algorithms is required for ensuring cell culture medium homeostasis. Stem cells also sense the physical constraints of their microenvironment. Rigidity, stiffness and geometry of the culture substrate influence stem cell fate. Hence, nanotopography is probably as important as medium formulation in the optimization of stem cell culture conditions. Recent advances include the development of synthetic bioinformative substrates designed at the micro- and nanoscale level. On going research in many different fields including stem cell biology, nanotechnology, and bioengineering suggest that our current way to culture cells in Petri dish or flasks will soon be outdated as flying across the Atlantic Ocean in the Lindbergh’s plane.

Van Der Sanden, Boudewijn; Dhobb, Mehdi; Berger, Francois; Wion, Didier

2010-01-01

33

Ureaplasma infection of cell cultures.  

PubMed Central

Studies were performed to characterize the effects of ureaplasmas in HeLa, 3T6, and CV-1 cell cultures. The ureaplasmas studied were human Ureaplasma urealyticum T960 (serotype VIII), bovine U. diversum T95, simian strain T167-2, ovine strain 1202, canine strain D1M-C, and feline strains 382 and FT2-B. FT2-B was the only ureaplasma to grow in the cell free culture medium, Dulbecco modified Eagle-Earle medium containing 10% fetal bovine serum. The growth pattern of the ureaplasmas varied in the different cell cultures, but each strain grew in at least two of the cell cultures, suggesting a requirement for a product of the cell culture and for low concentrations of urea. When growth occurred, organisms grew to concentrations that approached, but did not equal, those observed in 10B broth. Most, but not all, ureaplasmas grew quickly, reaching peak titers 2 days after infection. Canine strain D1M-C did not grow in 3T6, but showed rapid growth in HeLa and CV-1 cells, killing both cultures, In some systems, e.g., U. urealyticum T960 and simian strain T167-2, the infection persisted, and ureaplasmas could be recovered from cell cultures four passages after infection, when studies were terminated. The cell culture ureaplasmas grew on T agar, but not on mycoplasma agar medium. Images

Kotani, H; McGarrity, G J

1986-01-01

34

[A pilot study on the culture and differentiation of bone marrow stromal cells from SD rats].  

PubMed

In order to observe the growth, expansion and differentiation of the cultured bone marrow stromal cells (BMSC), we isolated the BMSC from adult SD rats and cultivated them with LIF and bFGF. Then, we cultured and induced the stem cells by using retinoic acid and the culture medium confected in our lab by ourselves. We found that the BMSC could expand and generate clones when they were cultured in vitro. These cells subcultured grew rapidly and differentiated into neuron-like cells and astrocyte-like cells. The results showed that BMSC have the abilities to self renew and differentiate, thus demonstrating the culture method we used is suitable for the culture of BMSC in vitro. The bone marrow stromal cell is not difficult to obtain; it is capable of expanding and differentiating in culture. If the culture condition is appropriate, it can differentiate into neuron and astrocyte. So, it is a kind of perfect seed cells. PMID:15022454

Li, Gang; Ke, Yiquan; Jiang, Xiaodan; Xu, Ruxiang; Zhou, Yuxi; Wang, Wei; Cheng, Wenping; Liao, Keli

2004-02-01

35

Primary culture of trigeminal satellite glial cells: a cell-based platform to study morphology and function of peripheral glia  

PubMed Central

Primary cell culture provides an experimental platform in which morphology, physiology, and cell-cell communication pathways can be studied under a well-controlled environment. Primary cell cultures of peripheral and central glia offer unique possibilities to clarify responses and pathways to different stimuli. Peripheral glia, satellite glial cells (SGCs), which surround neuronal cell bodies within sensory ganglia, have recently been known as key players in inflammation and neuronal sensitization. The objectives of this study were 1) to establish a cell-based platform of cultured trigeminal SGCs to study glial marker expression and functions under control conditions; 2) to validate the cell-based platform by prostaglandin E2 (PGE2) release response following administration of Cisplatin; and 3) to investigate inhibition of PGE2 release by glial modulators, Ibudilast and SKF86002. Primary cell cultures of SGCs from rat trigeminal ganglia were established following enzymatically and mechanically dissociation of the ganglia. Cultures were characterized in vitro for up to 21 days post isolation for morphological and immunocytochemical characteristics. PGE2 release, determined by ELISA, was used as a pro-inflammatory marker to characterize SGCs response to chemotherapeutic agent, Cisplatin, known to contribute in chemotherapy-induced peripheral neuropathy. Our results indicate that 1) isolated SGCs maintained their characteristics in vitro for up to 21 days; 2) Cisplatin enhanced PGE2 release from the SGCs, which was attenuated by Ibudilast and SKF86002. These findings confirm the utility and validity of the cultured trigeminal SGCs platform for glial activation and modulation; and suggest further investigation on Ibudilast and SKF86002 in prevention of chemotherapy-induced pain.

Poulsen, Jeppe N; Larsen, Frederik; Duroux, Meg; Gazerani, Parisa

2014-01-01

36

Selection of reference genes for expression studies with fish myogenic cell cultures  

Microsoft Academic Search

BACKGROUND: Relatively few studies have used cell culture systems to investigate gene expression and the regulation of myogenesis in fish. To produce robust data from quantitative real-time PCR mRNA levels need to be normalised using internal reference genes which have stable expression across all experimental samples. We have investigated the expression of eight candidate genes to identify suitable reference genes

Neil I Bower; Ian A Johnston

2009-01-01

37

Progeria: A cell culture study and clinical report of familial incidence  

Microsoft Academic Search

This report relates the case histories of two sisters who demonstrated the typical symptoms of progeria at birth. One of these children had died previous to this study. The familial occurrence underlines the thesis that progeria is an autosomal-recessive disorder. The examination of the cultured skin fibroblasts from the younger child showed a clear decrease in cell growth. On the

Thomas Rautenstrauch; Friedemann Snigula; Thomas Krieg; Steffen Gay; P. K. Müller

1977-01-01

38

IV. Studies of Three Strains in Primary Bovine Foetal Kidney Cell Cultures  

PubMed Central

Three different strains of bluetongue virus were adapted to grow in primary bovine foetal kidney cell cultures. The cytopathic effects observed from the three strains were similar, and were characterized by shrinkage of cells and increased granularity. The specificity of the changes was confirmed by the fluorescent antibody technique. No significant immunological cross-reaction was detected by serum-virus neutralization tests from the strains studied.

Girard, A.; Ruckerbauer, G. M.; Gray, D. P.; Bannister, G. L.; Boulanger, P.

1967-01-01

39

[Liver cell culture in bioreactors for in vitro drug studies as an alternative to animal testing].  

PubMed

An important consideration for the utilisation of in vitro culture models for studies on drug metabolism as an alternative to animal testing is the maintenance of a defined degree of cell differentiation. Thus, in vitro conditions reflecting as near as possible the in vivo situation of the cells within the whole organ are required. A bioreactor was developed for the cultivation of liver cells which allows the reorganisation of hepatocytes and non-parenchymal cells of the liver in coculture to form three-dimensional, tissue-like structures including extracellular matrix components produced by the cells. In this study, the vitality and metabolic activity of isolated rat hepatocytes was investigated over a two week culture period in bioreactors. The results show that after a reorganisation phase, the cells preserve specific functions, such as protein and urea synthesis capacity and specific cytochrome P450 activities during the culture period, with maximal values during the first week. Possible applications of the model in pharmaceutical industry are studies on metabolite patterns, enzyme induction, drug-drug-interactions, first pass effects and long-term toxicity of drugs. PMID:11103107

Zeilinger, K; Auth, S; Unger, J; Grebe, A; Mao, L; Petrik, M; Holland, G; Appel, K; Nüssler, A; Neuhaus, P; Gerlach, J

2000-01-01

40

May toxicity of amiodarone be prevented by antioxidants? A cell-culture study  

PubMed Central

Background Atrial Fibrillation is the most common arrhythmia encountered following cardiac surgery. The most commonly administered drug used in treatment and prophylaxis is amiodarone which has several toxic effects on major organ functions. There are few clinical data concerning prevention of toxic effects and there is no routinely suggested agent. The aim of this study is to document the cytotoxic effects of amiodarone on cell culture media and compare the cytoprotective effects of commonly used antioxidant agents. Methods L929 mouse fibroblast cell line was cultured and 100,000 cells/well-plate were obtained. First group of cells were treated with increasing concentrations of amiodarone (20 to 180 ?M) alone. Second and third group of cells were incubated with one-fold equimolar dose of vitamin C and N-acetyl cysteine prior to amiodarone exposure. The viability of cells were measured by MTT assay and the cytoprotective effect of each agent was compared. Results The cytotoxicity of amiodarone was significant with concentrations of 100 ?M and more. The viabilities of both vitamin C and N-acetyl cysteine treated cells were higher compared to untreated cells. Conclusions Vitamin C and N-acetyl cysteine are commonly used in the clinical setting for different purposes in context of their known antioxidant actions. Their role in prevention of amiodarone induced cytotoxicity is not fully documented. The study fully demonstrates the cytoprotective role of both agents in amiodarone induced cytotoxicity on cell culture media; more pronounced with vitamin C in some concentrations. The findings may be projectile for further clinical studies.

2012-01-01

41

PCL-coated hydroxyapatite scaffold derived from cuttlefish bone: In vitro cell culture studies.  

PubMed

In the present study, we examined the potential of using highly porous poly(?-caprolactone) (PCL)-coated hydroxyapatite (HAp) scaffold derived from cuttlefish bone for bone tissue engineering applications. The cell culture studies were performed in vitro with preosteoblastic MC3T3-E1 cells in static culture conditions. Comparisons were made with uncoated HAp scaffold. The attachment and spreading of preosteoblasts on scaffolds were observed by Live/Dead staining Kit. The cells grown on the HAp/PCL composite scaffold exhibited greater spreading than cells grown on the HAp scaffold. DNA quantification and scanning electron microscopy (SEM) confirmed a good proliferation of cells on the scaffolds. DNA content on the HAp/PCL scaffold was significantly higher compared to porous HAp scaffolds. The amount of collagen synthesis was determined using a hydroxyproline assay. The osteoblastic differentiation of the cells was evaluated by determining alkaline phosphatase (ALP) activity and collagen type I secretion. Furthermore, cell spreading and cell proliferation within scaffolds were observed using a fluorescence microscope. PMID:25063118

Milovac, Dajana; Gamboa-Martínez, Tatiana C; Ivankovic, Marica; Gallego Ferrer, Gloria; Ivankovic, Hrvoje

2014-09-01

42

Mammalian Cell Culture Simplified.  

ERIC Educational Resources Information Center

A tissue culture experiment that does not require elaborate equipment and that can be used to teach sterile technique, the principles of animal cell line maintenance, and the concept of cell growth curves is described. The differences between cancerous and normal cells can be highlighted. The procedure is included. (KR)

Moss, Robert; Solomon, Sondra

1991-01-01

43

Neurotoxic effects of indocyanine green -cerebellar granule cell culture viability study.  

PubMed

The aim of this study was to examine neurotoxicity indocyanine green (ICG). We assessed viability of primary cerebellar granule cell culture (CGC) exposed to ICG to test two mechanisms that could be the first triggers causing neuronal toxicity: imbalance in calcium homeostasis and the degree of oligomerization of ICG molecules. We have observed this imbalance in CGC after exposure to 75-125?? ICG and dose and application sequence dependent protective effect of Gadovist on surviving neurons in vitro when used with ICG. Spectroscopic studies suggest the major cause of toxicity of the ICG is connected with oligomers formation. ICG at concentration of 25 ?M (which is about 4 times higher than the highest concentration of ICG in the brain applied in in-vivo human studies) is not neurotoxic in the cell culture. PMID:24688815

Toczylowska, Beata; Zieminska, Elzbieta; Goch, Grazyna; Milej, Daniel; Gerega, Anna; Liebert, Adam

2014-03-01

44

Biocompatibility studies on fibrin glue cultured with bone marrow mesenchymal stem cells in vitro  

Microsoft Academic Search

Summary  By culturing bone marrow mesenchymal stem cells of rabbits with fibrin gluein vitro, the biocompatibility of fibrin glue was investigated to study whether this material can be used as scaffolds in bone tissue\\u000a engineering. After 2-months old New Zealand rabbits had been anesthetized, about 4–6 ml of bone marrow were aspirated from\\u000a rabbit femoral trochanter. The monocytes suspension was aspirated

Fang Huang; Peng Songlin; Chen Anmin; Li Fengfeng; Ren Kai; Hu Ning

2004-01-01

45

Suspension culture of mammalian cells.  

PubMed

Mammalian cell suspension culture systems are being used increasingly in the biotechnology industry. This is due to their many advantages including simplicity and homogeneity of culture. Suspension systems are very adaptable (e.g., for microcarrier, microencapsulation, or other methods of culture). Their engineering is thoroughly understood and standardized at large scale, and automation and cleaning procedures are well established. Suspension systems offer the possibility of quick implementation of production protocols due to their ability to be scaled easily once the basic culture parameters are understood. The only main disadvantage of the suspension culture systems to date is their inapplicability for the production of human vaccines from either primary cell lines or from normal human diploid cell lines (Hayflick et al., 1987 and references therein). One of the great advantages of suspension culture is the opportunity it provides to study interactions of metabolic and production phenomena in chemostat or turbidostat steady-state systems. Furthermore, in suspension culture systems from which cell number and cell mass measurements are easy to obtain, rigorous and quantitative estimations of the effects of growth conditions or perturbations of metabolic homeostasis can be made. Such studies can speed up the development of optimal processes. With our increasing understanding of factors influencing expression in mammalian cells (Cohen and Levinson, 1988; Santoro et al., 1988) and the direct application of new methods in suspension culture (Rhodes and Birch, 1988), its usefulness and importance is likely to increase in the future. In this chapter, we have described some of the potential uses of the various suspension culture systems and have covered most of the established technology and literature. Due to the rapid developments and needs in the biotechnology industry and the versatility of suspension culture systems, it is probable that many more variations on this theme will evolve in the near future at both the pilot and production scales. PMID:1367062

Birch, J R; Arathoon, R

1990-01-01

46

A study of enzymatic activity in cell cultures via the analysis of volatile biomarkers.  

PubMed

Aldehyde dehydrogenase (ALDH) enzymes are responsible for the metabolism of aldehydes, including acetaldehyde (AA), and are linked to disease. We describe a method to study ALDH activity in cell cultures involving the measurement of AA concentrations in the gas/vapour phase. This has been achieved using selected ion flow tube mass spectrometry (SIFT-MS), developed for the rapid quantification of trace gases in humid media. Human cells of the hepG2 hepatocellular carcinoma cell line and primary bone marrow-derived mesenchymal stem cells (hMSCs) depleted AA from the culture media, but the application of ALDH inhibitors diethylaminobenzaldehyde (DEAB) and disulfiram (DSF), suppressed this depletion or in some cases resulted in elevated AA concentrations. Further, the cells were shown to reduce the dimethyl sulphoxide (DMSO) to dimethyl sulphide, which is mediated by methionine sulfoxide reductase A (MsrA) enzymes. Interestingly, this process was also inhibited by DEAB and DSF. The results of this study indicate that SIFT-MS gas phase analysis could be applied to the study of volatile metabolites of intracellular enzyme reactions, this having potential utility in disease research and drug discovery. PMID:22930361

Chippendale, Thomas W E; Hu, Bin; El Haj, Alicia J; Smith, David

2012-10-21

47

beta-Glucoronidase and the gastric epithelial cell. A study using organ culture.  

PubMed

In an attempt to determine the significance of increased beta-glucuronidase content of gastric juice of patients with gastric carcinoma, gastric mucosal cells were exposed, in organ culture technique, to a known gastric carcinogen and indices of carcinogenic activity were studied in the ambient fluid and in the mucosal cells. Isotopic methods were used to determine cell viability. Indices of carcinogenic activity in the ambient fluid were beta-glucuronidase and lactate production and changes in the LDH isoenzyme pattern of the homogenates of the exposed cells were also studied. Incubation with the carcinogen resulted in increased production of beta-glucuronidase and lactate, suggesting the increased beta-glucuronidase activity in the gastric juice of patients with gastric cancer indicates malignancy. PMID:615735

Tayler, R; Orwell, R L; Piper, D W

1977-01-01

48

Preliminary Study of a Membrane Bioreactor for Cell Culture in Space.  

National Technical Information Service (NTIS)

Cell culture in microgravity may allow a better knowledge of human physiology in space and requires development of bioreactors capable of working continuously under high cell density, without perturbation of, or by, microgravity. Among existing types of b...

P. Binot I. Geahel R. Mattout

1990-01-01

49

Perhexiline maleate-induced lipidosis in cultured human fibroblasts : Cell kinetics, ultrastructural and biochemical studies  

Microsoft Academic Search

Summary  Perhexiline maleate reduced the growth of human skin fibroblasts in cell culture at a concentration range of 0.3–3 micrograms\\/ml.\\u000a At the highest concentration, the cells survived only four days. Pleomorphic inclusions characteristic of drug-induced phospholipidoses\\u000a appeared in cultured cells. Analysis of the major lipid classes was performed on cells exposed to 3 micrograms\\/ml at four\\u000a days. Gangliosides, phospholipids and cholesterol

J.-J. Hauw; J.-M. Boutry; S. Albouz; M. L. Harpin; M. Baudrimont; R. Escourolle; N. Baumann

1980-01-01

50

Poly(dimethylsiloxane) thin films as biocompatible coatings for microfluidic devices : cell culture and flow studies with glial cells.  

SciTech Connect

Oxygen plasma treatment of poly(dimethylsiloxane) (PDMS) thin films produced a hydrophilic surface that was biocompatible and resistant to biofouling in microfluidic studies. Thin film coatings of PDMS were previously developed to provide protection for semiconductor-based microoptical devices from rapid degradation by biofluids. However, the hydrophobic surface of native PDMS induced rapid clogging of microfluidic channels with glial cells. To evaluate the various issues of surface hydrophobicity and chemistry on material biocompatibility, we tested both native and oxidized PDMS (ox-PDMS) coatings as well as bare silicon and hydrophobic alkane and hydrophilic oligoethylene glycol silane monolayer coated under both cell culture and microfluidic studies. For the culture studies, the observed trend was that the hydrophilic surfaces supported cell adhesion and growth, whereas the hydrophobic ones were inhibitive. However, for the fluidic studies, a glass-silicon microfluidic device coated with the hydrophilic ox-PDMS had an unperturbed flow rate over 14 min of operation, whereas the uncoated device suffered a loss in rate of 12%, and the native PDMS coating showed a loss of nearly 40%. Possible protein modification of the surfaces from the culture medium also were examined with adsorbed films of albumin, collagen, and fibrinogen to evaluate their effect on cell adhesion.

Peterson, Sophie Louise; Sasaki, Darryl Yoshio; Gourley, Paul Lee; McDonald, Anthony Eugene

2004-06-01

51

Chlorophyllous totipotent maize cell cultures  

US Patent & Trademark Office Database

The subject invention provides totipotent, chlorophyllous, cell cultures of maize. In addition, the methods of producing such cultures are applicable to other related species, including cereals such as rice, oats, barley, and heat. The subject cultures are valuable for herbicide studies, studies for enhancing photosynthesis, and genetic manipulation, such as plastid transformation. The methods of the subject invention are capable of providing high percentages of totipotent cells. These cells are capable of sustained cell division and are competent for regeneration over long periods; they provide high-quality target tissue for nuclear and organelle transformation. The invention also describes methods for the introduction of heterologous DNA into the chloroplast genome. The present invention also provides methods, vectors, and gene constructs for enhancing expression of a recombinant nucleic acid sequence in transgenic plants and plant tissues.

2011-10-18

52

A permeabilized cell model for studying cytokinesis using mammalian tissue culture cells  

PubMed Central

PtK1 cells lysed late in cell division in a medium containing the nonionic detergent Brij 58 and polyethylene glycol with continue to undergo cleavage after lysis. Maintenance of cleavage after lysis is dependent on the composition of the lysis medium; the pH must be around neutrality, MgATP must be present, and the free Ca++ concentration should be 1 microM for optimal constriction to occur. Cleavage can be stopped and reinitiated by raising and lowering the Ca++ levels in the lysis medium. Cleavage in the permeabilized cell is blocked by addition of phalloidin, cytochalasin B, and N-ethylmaleimide-modified myosin subfragment-1 to the lysis medium. This represents the first cell model system for studying cleavage since the pioneering studies of Hoffman- Berling in 1954.

1980-01-01

53

Design Study Conducted of a Stirred and Perfused Specimen Chamber for Culturing Suspended Cells on the International Space Station  

NASA Technical Reports Server (NTRS)

A tightly knit numerical/experimental collaboration among the NASA Ames Research Center, NASA Glenn Research Center, and Payload Systems, Inc., was formed to analyze cell culturing systems for the International Space Station. The Cell Culture Unit is a facility scheduled for deployment on the space station by the Cell Culture Unit team at Ames. The facility houses multiple cell specimen chambers (CSCs), all of which have inlets and outlets to allow for replenishment of nutrients and for waste removal. For improved uniformity of nutrient and waste concentrations, each chamber has a pair of counterrotating stir bars as well. Although the CSC can be used to grow a wide variety of organic cells, the current study uses yeast as a model cell. Previous work identified groundbased protocols for perfusion and stirring to achieve yeast growth within the CSC that is comparable to that for yeast cultures grown in a shaken Ehrlenmeyer flask.

Nelson, Emily S.; Kizito, John P.

2003-01-01

54

Differentiation and Development in Plant Cell Cultures.  

National Technical Information Service (NTIS)

Differentiation in plant cell cultures was studied by tissue culture and genetic approaches. The influence of various environmental factors on differentiation was elucidated using Digitalis lanata protoplasts in the first part of the study. The molecular ...

R. Puupponen-Pimiae

1995-01-01

55

HEK293 cell culture media study towards bioprocess optimization: Animal derived component free and animal derived component containing platforms.  

PubMed

The increasing demand for biopharmaceuticals produced in mammalian cells has lead industries to enhance bioprocess volumetric productivity through different strategies. Among those strategies, cell culture media development is of major interest. In the present work, several commercially available culture media for Human Embryonic Kidney cells (HEK293) were evaluated in terms of maximal specific growth rate and maximal viable cell concentration supported. The main objective was to provide different cell culture platforms which are suitable for a wide range of applications depending on the type and the final use of the product obtained. Performing simple media supplementations with and without animal derived components, an enhancement of cell concentration from 2 × 10(6) cell/mL to 17 × 10(6) cell/mL was achieved in batch mode operation. Additionally, the media were evaluated for adenovirus production as a specific application case of HEK293 cells. None of the supplements interfered significantly with the adenovirus infection although some differences were encountered in viral productivity. To the best of our knowledge, the high cell density achieved in the work presented has never been reported before in HEK293 batch cell cultures and thus, our results are greatly promising to further study cell culture strategies in bioreactor towards bioprocess optimization. PMID:24183458

Liste-Calleja, Leticia; Lecina, Martí; Cairó, Jordi Joan

2014-04-01

56

Studies on Culture and Osteogenic Induction of Human Mesenchymal Stem Cells under CO2-Independent Conditions  

PubMed Central

Abstract Human mesenchymal stem cells (hMSCs) are one of the important factors that regulate bone anabolism. Osteoporosis resulting from microgravity during spaceflight may possibly be due to a decrease in osteogenesis mediated by hMSCs. This speculation should be verified through culture and osteogenic induction of hMSCs in a microgravity environment during spaceflight. Control of CO2 is a key component in current experimental protocols for growth, survival, and proliferation of in vitro cultured cells. However, carrying CO2 tanks on a spaceflight and devoting space/mass allowances for classical CO2 control protocols make experimentation on culture and osteogenesis difficult during most missions. Therefore, an experimental culture and osteogenic medium was developed through modifying the components of buffer salts in conventional culture medium. This experimental medium was used to culture and induce hMSCs under CO2-independent conditions. The results showed that culture and induction of hMSCs with conventional culture medium and conventional osteogenic medium under CO2-independent conditions resulted in an increase of pH in medium. The proliferation of hMSCs was also inhibited. hMSCs cultured with experimental culture medium under CO2-independent conditions showed a proliferation potential that was the same as those cultured with conventional culture medium under CO2-dependent conditions. The experimental osteogenic medium could promote hMSCs to differentiate into osteoblast-like cells under CO2-independent conditions. Cells induced by this induction system showed high alkaline phosphatase activity. The expression levels of osteogenic genes in cells induced with experimental osteogenic medium under CO2-independent conditions were not significantly different from those cells induced with conventional osteogenic medium under CO2-dependent conditions. These results suggest that the experimental culture and induction system could be used to culture hMSCs and induce the osteogenesis of hMSCs in the atmospheric conditions common to spaceflights without additional CO2. Key Words: hMSCs—CO2-independent culture—Osteogenic differentiation—Proliferation. Astrobiology 13, 370–379.

Chen, Jian; Zhang, Cui; Feng, Yiding; Zong, Chen; Chen, Jiarong; Tang, Zihua; Jia, Bingbing; Tong, Xiangming; Zheng, Qiang

2013-01-01

57

An Ideal Selective Anti-Cancer Agent In Vitro: I - Tissue Culture Study of Human Lung Cancer Cells A549  

Microsoft Academic Search

Management of cancer is one of the challenging problems in medical practice as there are no available medical modalities that can se- lectively kill cancer cells without adverse effect on normal living cells or the functions of vital organs. Tissue culture of human lung cancer cells (A549) was used in studying the effect of agent, PM 701, to test its

FATEN A. KHORSHID; SABAH S. MUSHREF; NAGWA T. HEFFNY

2005-01-01

58

Studies on the Growth of Human Carcinoma Cells in Tissue Culture  

Microsoft Academic Search

SUMMARY The KB line of human epidermoid carcinoma cells grew with a minimum genera tion time of 15 hours when cultured in Eagle's medium containing human or calf serum. The maximum cell concentration was a function of the frequency of medium renewal, the time of incubation, and the amount of final cellular material present. Maximum cell density could be increased

CHARLES G. SMITH; WILLIAM L. LUMMIS; JOSEPH E. GRADY

59

Studies of formation and efflux of methotrexate polyglutamates with cultured hepatic cells.  

PubMed

Methotrexate polyglutamates are extensively synthesized when cultured hepatocytes and H35 hepatoma cells are exposed to micromolar concentrations of methotrexate. The predominant species found within the cell have from two to four additional gamma-linked glutamate residues. When either cell type containing a mixture of methotrexate and its polyglutamate derivatives is exposed to medium lacking methotrexate, there is a rapid release of methotrexate. This release has a T1/2 of 2 to 4 min and is apparently complete within 30 to 60 min. Methotrexate polyglutamates leave the cells much more slowly and appear to do so by two mechanisms. Although cleavage to methotrexate and subsequent efflux appears to be quantitatively the more important pathway, there is also a slow, finite loss of intact methotrexate polyglutamates from cells which exclude trypan blue. The T1/2 for the loss of methotrexate polyglutamates by both cell types, when placed in medium lacking methotrexate, is approximately 6 to 8 hr. These results, together with those of an earlier study (Galivan, J. (1980) Mol. Pharmacol. 17:105-110), suggest that the polyglutamate derivatives are forms of methotrexate which are as cytotoxic as methotrexate but which offer a potentially greater capacity for cellular destruction because they are retained longer in the tissue. PMID:6193687

Galivan, J; Balinska, M

1983-01-01

60

Differential Activities of Glycolipid Glycosyltransferases in Tay-Sachs Disease: Studies in Cultured Cells from Cerebrum  

Microsoft Academic Search

Four different glycolipid:glycosyltransferase activities involved in the biosynthesis in vitro of gangliosides and blood group-related glycosphingolipids have been tested in a simian virus 40-transformed glial cell culture derived from the cerebrum of a fetus with Tay-Sachs disease (TSD). The TSD cultured brain cells contained little activity of either UDP-Gal:GM2 (beta 1-3)galactosyltransferase (GalT-3; EC 2.4.1.62), which catalyzes the formation of GM1a

Manju Basu; Kathleen A. Presper; Subhash Basu; Linda M. Hoffman; Steven E. Brooks

1979-01-01

61

Isometric contraction by fibroblasts and endothelial cells in tissue culture: a quantitative study  

PubMed Central

We have used an isometric force transducer to study contraction of two types of nonmuscle cells in tissue culture. This method permits the quantitative measurement of contractile force generated by cells of defined type under the influence of external agents while allowing detailed morphological observation. Chick embryo fibroblasts (CEF), which form a contractile network inside a collagen matrix, and human umbilical vein endothelial cells (HUVE), which are located in a monolayer on the surface of the collagen matrix, were studied. CEF and HUVE in 10% FCS produce a substantial tension of 4.5 +/- 0.2 x 10(4) dynes/cm2 and 6.1 x 10(4) dynes/cm2, respectively. Both cell types contract when stimulated with thrombin, generating a force per cell cross-sectional area of approximately 10(5) dynes/cm2, a value approximately an order of magnitude less than smooth muscle. The integrity of the actin cytoskeleton is essential for force generation, as disruption of actin microfilaments with cytochalasin D results in a rapid disappearance of force. Intact microtubules appear to reduce isometric force exerted by CEF, as microtubule-disrupting drugs result in increased tension. Contraction by HUVE precedes a dramatic rearrangement of actin microfilaments from a circumferential ring to stress fibers.

1992-01-01

62

Application of speckle dynamics for studying metabolic activity of cell cultures with herpes virus  

NASA Astrophysics Data System (ADS)

The report considers the results of the experiments in which digital values of light intensity I and the image area correlation index ? values were recorded on a real-time basis for one or two days. Three cell cultures with viruses along with intact cultures were investigated. High correlation of dependence of ? values on time t values was demonstrated for three cultures. The ?=?(t) and I=I(t) dependences for cells with and without viruses differ considerably. It was shown that the presence of viruses could be determined as early as ten minutes after measurements were started.

Vladimirov, A. P.; Bakharev, A. A.; Malygin, A. S.; Mikhaylova, J. A.; Borodin, E. M.; Poryvayeva, A. P.; Glinskikh, N. P.

2014-05-01

63

Microfluidic-driven viral infection on cell cultures: Theoretical and experimental study  

PubMed Central

Advanced cell culture systems creating a controlled and predictable microenvironment together with computational modeling may be useful tools to optimize the efficiency of cell infections. In this paper, we will present a phenomenological study of a virus-host infection system, and the development of a multilayered microfluidic platform used to accurately tune the virus delivery from a diffusive-limited regime to a convective-dominated regime. Mathematical models predicted the convective-diffusive regimes developed within the system itself and determined the dominating mass transport phenomena. Adenoviral vectors carrying the enhanced green fluorescent protein (EGFP) transgene were used at different multiplicities of infection (MOI) to infect multiple cell types, both in standard static and in perfused conditions. Our results validate the mathematical models and demonstrate how the infection processes through perfusion via microfluidic platform led to an enhancement of adenoviral infection efficiency even at low MOIs. This was particularly evident at the longer time points, since the establishment of steady-state condition guaranteed a constant viral concentration close to cells, thus strengthening the efficiency of infection. Finally, we introduced the concept of effective MOI, a more appropriate variable for microfluidic infections that considers the number of adenoviruses in solution per cell at a certain time.

Cimetta, Elisa; Franzoso, Mauro; Trevisan, Marta; Serena, Elena; Zambon, Alessandro; Giulitti, Stefano; Barzon, Luisa; Elvassore, Nicola

2012-01-01

64

A microfluidic system for automatic cell culture  

NASA Astrophysics Data System (ADS)

This study presents a new chip capable of automating the cell culture process by using microfluidic technology. This microfluidic cell culture system comprising microheaters, a micro temperature sensor, micropumps, microvalves, microchannels, a cell culture area and several reservoirs was fabricated by using micro-electro-mechanical-systems' fabrication processes. Traditional manual cell culture processes can be performed on this chip. A uni-directional pneumatic micropump was developed to transport the culture reagents and constraint the solutions to flow only in one direction, safeguarding the entire culture process from contamination. A new micro check valve was also used to prevent the culture solutions from flowing back into the microchannels. The microheaters and the micro temperature sensor were used to maintain a constant temperature during the cell culturing process. The pH value suitable for cell growth was also regulated during the cell culture process. A typical cell culturing process for human lung cancer cells (A549) was successfully performed to demonstrate the capability of the developed microfluidic system. This automatic cell culturing system can be eventually integrated with subsequent microfluidic modules for cell purification, collection, counting and lysis to form a cell-based micro-total-analysis system. Preliminary results have been presented in The Asia-Pacific Conference of Transducers and Micro-Nano Technology (APCOT), 25-28 June 2006

Huang, Chun-Wei; Lee, Gwo-Bin

2007-07-01

65

3D organotypic cultures of human HepaRG cells: a tool for in vitro toxicity studies.  

PubMed

Drug-induced human hepatotoxicity is difficult to predict using the current in vitro systems. In this study, long-term 3D organotypic cultures of the human hepatoma HepaRG cell line were prepared using a high-throughput hanging drop method. The organotypic cultures were maintained for 3 weeks and assessed for (1) liver specific functions, including phase I enzyme and transporter activities, (2) expression of liver-specific proteins, and (3) responses to three drugs (acetaminophen, troglitazone, and rosiglitazone). Our results show that the organotypic cultures maintain high liver-specific functionality during 3 weeks of culture. The immunohistochemistry analyses illustrate that the organotypic cultures express liver-specific markers such as albumin, CYP3A4, CYP2E1, and MRP-2 throughout the cultivation period. Accordingly, the production rates of albumin and glucose, as well as CYP2E1 activity, were significantly higher in the 3D versus the 2D cultures. Toxicity studies show that the organotypic cultures are more sensitive to acetaminophen- and rosiglitazone-induced toxicity but less sensitive to troglitazone-induced toxicity than the 2D cultures. Furthermore, the EC50 value (2.7mM) for acetaminophen on the 3D cultures was similar to in vivo toxicity. In summary, the results from our study suggest that the 3D organotypic HepaRG culture is a promising in vitro tool for more accurate assessment of acute and also possibly for chronic drug-induced hepatotoxicity. PMID:23377618

Gunness, Patrina; Mueller, Daniel; Shevchenko, Valery; Heinzle, Elmar; Ingelman-Sundberg, Magnus; Noor, Fozia

2013-05-01

66

Physiological and morphological studies of rat pheochromocytoma cells (PC12) chemically fused and grown in culture.  

PubMed Central

Cell fusion induced by polyethylene glycol has been used to produce in culture giant multinucleate PC12 cells (up to 300 micron in diameter compared to 10-20 micron for unfused cells). Fused cells, like their unfused counterparts, were found to express various neuronal properties. They contained catecholamines. In the presence of nerve growth factor they extended long processes and expressed Na+, Ca2+, and K+ conductances generally associated with excitable cells. In the absence of nerve growth factor these cells neither grew long processes nor generated Na+-spikes. Other neuronal properties were also observed. Images

O'Lague, P H; Huttner, S L

1980-01-01

67

Cultured Human Renal Cortical Cells  

NASA Technical Reports Server (NTRS)

During the STS-90 shuttle flight in April 1998, cultured renal cortical cells revealed new information about genes. Timothy Hammond, an investigator in NASA's microgravity biotechnology program was interested in culturing kidney tissue to study the expression of proteins useful in the treatment of kidney diseases. Protein expression is linked to the level of differentiation of the kidney cells, and Hammond had difficulty maintaining differentiated cells in vitro. Intrigued by the improvement in cell differentiation that he observed in rat renal cells cultured in NASA's rotating wall vessel (a bioreactor that simulates some aspects of microgravity) and during an experiment performed on the Russian Space Station Mir, Hammond decided to sleuth out which genes were responsible for controlling differentiation of kidney cells. To do this, he compared the gene activity of human renal cells in a variety of gravitational environments, including the microgravity of the space shuttle and the high-gravity environment of a centrifuge. Hammond found that 1,632 genes out of 10,000 analyzed changed their activity level in microgravity, more than in any of the other environments. These results have important implications for kidney research as well as for understanding the basic mechanism for controlling cell differentiation.

1998-01-01

68

Studies on the effects of microgravity on the ultrastructure and functions of cultured mammalian cells (L-6)  

NASA Technical Reports Server (NTRS)

The human body consists of 10(exp 13) cells. Understanding the mechanisms by which the cells sense and respond to microgravity is very important as the basis for space biology. The cells were originally isolated aseptically from mammalian bodies and cultured in vitro. A set of cell culture vessels was developed to be applied to three kinds of space flight experiments. Experiment 1 is to practice the cell culture technique in a space laboratory and obtain favorable growth of the cells. Aseptic handling in tryspin treatment and medium renewal will be tested. The cells, following space flight, will be returned to the ground and cultured continuously to investigate the effects of space flight on the cellular characteristics. Experiment 2 is to examine the cytoskeletal structure of the cells under microgravity conditions. The cytoskeletal structure plays essential roles in the morphological construction, movements, axonal transport, and differentiation of the cells. The cells fixed during space flight will be returned and the cytoskeleton and ultrastructure observed using electron microscopy and fluorescence microscopy. Experiment 3 is to study the cellular productivity of valuable substances. The waste medium harvested during space flight are returned and quantitated for the cellular products. The effects of microgravity on mammalian cells will be clarified from the various aspects.

Sato, Atsushige

1993-01-01

69

Immunoelectron microscopic studies of the sites of cell-substratum and cell-cell contacts in cultured fibroblasts  

PubMed Central

Our object was to obtain information about the molecular structures present at cell-substratum and cell-cell contact sites formed by cultured fibroblasts. We have carried out double immunoelectron- microscopic labeling experiments on ultrathin frozen sections cut through such contact sites to determine the absolute and relative dispositions of the three proteins fibronectin, vinculin, and alpha- actinin with respect to these sites. (a) Three types of cell-substratum and cell-cell contact sites familiar from plastic sections could also be discriminated in the frozen sections by morphological criteria alone, i.e., the gap distances between the two surfaces, and the presence of submembranous densities. These types were: (i) focal adhesions (FA); (ii) close contacts (CC); and (iii) extracellular matrix contacts (ECM). This morphological typing of the contact sites allowed us to recognize and assign distinctive immunolabeling patterns for the three proteins to each type of site on the frozen sections. (b) FA sites were immunolabeled intracellularly for vinculin and alpha- actinin, with vinculin labeling situated closer to the membrane than alpha-actinin. Fibronectin was not labeled in the narrow gap between the cell surface and the substratum, or between two cells, at FA sites. Control experiments showed that this could not be ascribed to inaccessibility of the FA narrow gap to the immunolabeling reagents but indicated an absence or severe depletion of fibronectin from these sites. (c) CC sites were labeled intracellularly for alpha-actinin but not vinculin and were labeled extracellularly for fibronectin. (d) ECM sites were characterized by large separations (often greater than 100 nm) between the cell and substratum or between two cells, which were connected by long cables of extracellular matrix components, including fibronectin. In late (24-36 h) cultures, ECM contacts predominated over the other types. ECM sites appeared to be of two kinds, one labeled intracellularly for both alpha-actinin and vinculin, the other for alpha-actinin alone. (e) From these and other results, a coherent but tentative scheme is proposed for the molecular ultrastructure of these contacts sites, and specific functional roles are suggested for fibronectin, vinculin, and alpha-actinin in cell adhesion and in the linkage of intracellular microfilaments to membranes at the different types of contact sites.

1982-01-01

70

Studies on the turnover and subcellular localization of membrane gangliosides in cultured neuroblastoma cells  

Microsoft Academic Search

To compare the subcellular distribution of endogenously synthesized and exogenous gangliosides, cultured murine neuroblastoma cells (N1E-115) were incubated in suspension for 22h in the presence ofd-[1-3H]galactose or [3H]GM1 ganglioside, transferred to culture medium containing no radioisotope for periods of up to 72 hr, and then subjected to subcellular fractionation and analysis of lipidsialic acid and radiolabeled ganglioside levels. The results

J. T. R. Clarke; H. W. Cook; M. W. Spence

1985-01-01

71

Phenol Red in Tissue Culture Media is a Weak Estrogen: Implications concerning the Study of Estrogen-Responsive Cells in Culture  

Microsoft Academic Search

Although much attention has been paid to the removal of hormones from sera and to the development of serum-free media for studies on hormone-responsive cells in culture, little consideration has been given to the possibility that the media components themselves may have hormonal activity. We have found that phenol red, which bears a structural resemblance to some nonsteroidal estrogens and

Yolande Berthois; John A. Katzenellenbogen; Benita S. Katzenellenbogen

1986-01-01

72

A brain slice culture model for studies of endogenous and exogenous precursor cell migration in the rostral migratory stream.  

PubMed

The rostral migratory stream (RMS) is the main pathway by which newly born subventricular zone (SVZ) cells reach the olfactory bulb (OB) in rodents. This migration has been well studied in vivo, but an organotypic in vitro model would facilitate more experimental investigations. Here we introduce a slice culture preparation of the rat forebrain including en suite the rostral part of the lateral ventricle, the RMS and the OB. The preparation was validated with regard to endogenous cell proliferation and migration by tracking bromodeoxyuridine (BrdU)-labelled cells in newly established and 3 and 6 week old cultures. For testing the migratory abilities of exogenous precursor cells, rat SVZ neurospheres and human neural (HNS1 cells) and mesenchymal (hMSC-TERT) stem cell lines were micrografted to the rostral SVZ of 1 and 7 day old cultures. Two weeks later graft derivatives were identified by immunohistochemical staining for human nuclei (HNS1/hMSC-TERT cells) and BrdU (HNS1 cells/neurospheres). Numerous HNS1 cells and BrdU-positive neurosphere cells were found in the RMS. Having reached the OB, subpopulations of the cells expressed the astroglial markers glial fibrillary acidic protein/hAM and the neuronal markers NeuN/tyrosine hydroxylase. Interestingly, the hMSC-TERT cells remained at the implantation site, demonstrating a diversity in migratory capability of different precursor cells. In conclusion, the RMS in rat forebrain slice cultures retains its ability to support migration of endogenous and exogenous neural precursors, making the cultures highly feasible for studies of conditions and factors regulating cell migration. PMID:19646977

Tanvig, Mette; Blaabjerg, Morten; Andersen, Rikke K; Villa, Ana; Rosager, Ann Mari; Poulsen, Frantz R; Martinez-Serrano, Alberto; Zimmer, Jens; Meyer, Morten

2009-10-27

73

Are quantum dots toxic? Exploring the discrepancy between cell culture and animal studies.  

PubMed

Despite significant interest in developing quantum dots (QDs) for biomedical applications, many researchers are convinced that QDs will never be used for treating patients because of their potential toxicity. The perception that QDs are toxic is rooted in two assumptions. Cadmium-containing QDs can kill cells in culture. Many researchers then assume that because QDs are toxic to cells, they must be toxic to humans. In addition, many researchers classify QDs as a homogeneous group of materials. Therefore, if CdSe QDs are harmful, they extrapolate this result to all QDs. Though unsubstantiated, these assumptions continue to drive QD research. When dosing is physiologically appropriate, QD toxicity has not been demonstrated in animal models. In addition, QDs are not uniform: each design is a unique combination of physicochemical properties that influence biological activity and toxicity. In this Account, we summarize key findings from in vitro and in vivo studies, explore the causes of the discrepancy in QD toxicological data, and provide our view of the future direction of the field. In vitro and in vivo QD studies have advanced our knowledge of cellular transport kinetics, mechanisms of QD toxicity, and biodistribution following animal injection. Cell culture experiments have shown that QDs undergo design-dependent intracellular localization and they can cause cytotoxicity by releasing free cadmium into solution and by generating free radical species. In animal experiments, QDs preferentially enter the liver and spleen following intravascular injection, undergo minimal excretion if larger than 6 nm, and appear to be safe to the animal. In vitro and in vivo studies show an apparent discrepancy with regard to toxicity. Dosing provides one explanation for these findings. Under culture conditions, a cell experiences a constant QD dose, but the in vivo QD concentration can vary, and the organ-specific dose may not be high enough to induce detectable toxicity. Because QDs are retained within animals, long-term toxicity may be a problem but has not been established. Future QD toxicity studies should be standardized and systematized because methodological variability in the current body of literature makes it difficult to compare and contrast results. We advocate the following steps for consistent, comparable toxicology data: (a) standardize dose metrics, (b) characterize QD uptake concentration, (c) identify in vitro models that reflect the cells QDs interact with in vivo, and (d) use multiple assays to determine sublethal toxicity and biocompatibility. Finally, we should ask more specific toxicological questions. For example: "At what dose are 5 nm CdSe QDs that are stabilized with mercaptoacetic acid and conjugated to the antibody herceptin toxic to HeLa cells?" rather than "Are QDs toxic?" QDs are still a long way from realizing their potential as a medical technology. Modifying the current QD toxicological research paradigm, investigating toxicity in a case-by-case manner, and improving study quality are important steps in identifying a QD formulation that is safe for human use. PMID:22853558

Tsoi, Kim M; Dai, Qin; Alman, Benjamin A; Chan, Warren C W

2013-03-19

74

Sedimentation of agglomerated nanoparticles under cell culture conditions studied by image based analysis  

NASA Astrophysics Data System (ADS)

Toxic effects of nanoparticles can be analyzed with alveolar macrophages in vitro. To quantify exposure of cells to particles we analyzed the sedimentation of nanoparticle agglomerates in cell culture medium (MEM) by means of phase contrast microscopy. Particles were suspended by brief ultrasonication in MEM and pipetted into a glass bottom culture dish on the stage of a Nikon-Biostation under cell culture condition. Successive images were captured from the lowermost optical plane and were converted into binary images. The number of agglomerates (N) as well as the particle-covered area (A) were determined by image analyses. Typically, N increased to a maximum value before it partially decayed due to overlapping and/or optical interference of particles, and finally became constant. In contrast, A increased in a monophasic manner. By means of mathematical modeling we identified the endpoint of sedimentation of particle agglomerates, which is an important though a largely neglected event in most cell culture experiments. This endpoint could be calculated from an approximated model function. As the method can be employed in the presence of cells, a parallel evaluation of particle sedimentation and particle uptake appears possible.

Schippritt, Darius; Wiemann, Martin; Lipinski, Hans-Gerd

2010-04-01

75

Cell culture's spider silk road.  

PubMed

A number of synthetic and natural materials have been tried in cell culture and tissue engineering applications in recent years. Now Jeffrey Perkel takes a look at one new culture component that might surprise you-spider silk. PMID:24924388

Perkel, Jeffrey

2014-01-01

76

Three dimensional cultures: a tool to study normal acinar architecture vs. malignant transformation of breast cells.  

PubMed

Invasive breast carcinomas are a group of malignant epithelial tumors characterized by the invasion of adjacent tissues and propensity to metastasize. The interplay of signals between cancer cells and their microenvironment exerts a powerful influence on breast cancer growth and biological behavior(1). However, most of these signals from the extracellular matrix are lost or their relevance is understudied when cells are grown in two dimensional culture (2D) as a monolayer. In recent years, three dimensional (3D) culture on a reconstituted basement membrane has emerged as a method of choice to recapitulate the tissue architecture of benign and malignant breast cells. Cells grown in 3D retain the important cues from the extracellular matrix and provide a physiologically relevant ex vivo system(2,3). Of note, there is growing evidence suggesting that cells behave differently when grown in 3D as compared to 2D(4). 3D culture can be effectively used as a means to differentiate the malignant phenotype from the benign breast phenotype and for underpinning the cellular and molecular signaling involved(3). One of the distinguishing characteristics of benign epithelial cells is that they are polarized so that the apical cytoplasm is towards the lumen and the basal cytoplasm rests on the basement membrane. This apico-basal polarity is lost in invasive breast carcinomas, which are characterized by cellular disorganization and formation of anastomosing and branching tubules that haphazardly infiltrates the surrounding stroma. These histopathological differences between benign gland and invasive carcinoma can be reproduced in 3D(6,7). Using the appropriate read-outs like the quantitation of single round acinar structures, or differential expression of validated molecular markers for cell proliferation, polarity and apoptosis in combination with other molecular and cell biology techniques, 3D culture can provide an important tool to better understand the cellular changes during malignant transformation and for delineating the responsible signaling. PMID:24797513

Pal, Anupama; Kleer, Celina G

2014-01-01

77

Experimental Model for Studying the Primary Cilia in Tissue Culture Cells  

Microsoft Academic Search

In HeLa, PK, 3T3, PtK1 cells and rat embryo fibroblasts (REF), antibodies against acetylated tobulin stained centrioles, primary cilia, some cytoplasmic microtubules and microtubule bundles of the mid-body. The primary cilia were stained more intensively than cytoplasmic microtubules and could easily be distinguished. This makes it possible to detect the primary cilia in cultured cells and to estimate their number

I. B. Aliev; L. A. Gorgidze; A. Komarova; O. A. Chernobelskaya; I. A. Vorobjev

78

UVA and visible light-induced reactive oxygen species (ROS) formation in cell cultures: an electron paramagnetic resonance (EPR) study  

NASA Astrophysics Data System (ADS)

The stimulatory effect of low energy light (LEL) has been attributed to irradiation-induced ROS formation. In the present study we demonstrate that irradiating various cell cultures such as fibroblasts, cardiac and sperm cells with UVA or various light sources in the visible range results in singlet oxygen and OH radical formation. These radicals were monitored by using the EPR technique. We believe that the light induced ROS could mediate previously documented effects of LEL on these cells.

Lubart, Rachel; Lavie, R.; Friedmann, Harry; Sinyakov, M.; Shainberg, Asher; Breitbart, Haim; Grossman, Nili

2000-11-01

79

Studies on the developmental potentiality of cultured cell nuclei of fish.  

PubMed

By means of the serial nuclear transplantation technique, the authors obtained a nuclear transplant fish from subcultured cell originated from the blastula cells of the crucian carp (Carassius auratus Linnaeus). This nuclear transplant fish survived for three years, but its sexual glands were undifferentiated. The authors have also obtained a sexually mature adult fish from short-term cultured kidney cell nucleus of an adult crucian carp. Results of the experiment implied that the subcultured cell nuclei of fish blastula cells and the specialized somatic cell nuclei of adult fish still retained their developmental totipotency, and thus, it indicated that there is a possibility of fish somatic cell breeding through the use of nuclear transplantation. PMID:20440385

Chen, Hongxi; Yi, Yonglan; Chen, Minrong; Yang, Xingqi

2010-01-01

80

Studies on the Developmental Potentiality of Cultured Cell Nuclei of Fish  

PubMed Central

By means of the serial nuclear transplantation technique, the authors obtained a nuclear transplant fish from subcultured cell originated from the blastula cells of the crucian carp (Carassius auratus Linnaeus). This nuclear transplant fish survived for three years, but its sexual glands were undifferentiated. The authors have also obtained a sexually mature adult fish from short-term cultured kidney cell nucleus of an adult crucian carp. Results of the experiment implied that the subcultured cell nuclei of fish blastula cells and the specialized somatic cell nuclei of adult fish still retained their developmental totipotency, and thus, it indicated that there is a possibility of fish somatic cell breeding through the use of nuclear transplantation.

Chen, Hongxi; Yi, Yonglan; Chen, Minrong; Yang, Xingqi

2010-01-01

81

Cell culture purity issues and DFAT cells  

SciTech Connect

Highlights: •DFAT cells are progeny cells derived from dedifferentiated mature adipocytes. •Common problems in this research is potential cell contamination of initial cultures. •The initial cell culture purity is crucial in DFAT cell research field. -- Abstract: Dedifferentiation of mature adipocytes, in vitro, has been pursued/documented for over forty years. The subsequent progeny cells are named dedifferentiated adipocyte-derived progeny cells (DFAT cells). DFAT cells are proliferative and likely to possess mutilineage potential. As a consequence, DFAT cells and their progeny/daughter cells may be useful as a potential tool for various aspects of tissue engineering and as potential vectors for the alleviation of several disease states. Publications in this area have been increasing annually, but the purity of the initial culture of mature adipocytes has seldom been documented. Consequently, it is not always clear whether DFAT cells are derived from dedifferentiated mature (lipid filled) adipocytes or from contaminating cells that reside in an impure culture.

Wei, Shengjuan [College of Animal Science and Technology, Northwest A and F University, Yangling, Shaanxi Province 712100 (China) [College of Animal Science and Technology, Northwest A and F University, Yangling, Shaanxi Province 712100 (China); Department of Animal Sciences, Washington State University, Pullman, WA 99164 (United States); Bergen, Werner G. [Program in Cellular and Molecular Biosciences/Department of Animal Sciences, Auburn University, Auburn, AL 36849 (United States)] [Program in Cellular and Molecular Biosciences/Department of Animal Sciences, Auburn University, Auburn, AL 36849 (United States); Hausman, Gary J. [Animal Science Department, University of Georgia, Athens, GA 30602-2771 (United States)] [Animal Science Department, University of Georgia, Athens, GA 30602-2771 (United States); Zan, Linsen, E-mail: zanls@yahoo.com.cn [College of Animal Science and Technology, Northwest A and F University, Yangling, Shaanxi Province 712100 (China)] [College of Animal Science and Technology, Northwest A and F University, Yangling, Shaanxi Province 712100 (China); Dodson, Michael V., E-mail: dodson@wsu.edu [Department of Animal Sciences, Washington State University, Pullman, WA 99164 (United States)

2013-04-12

82

Comparative genomic study of gastric epithelial cells co-cultured with Helicobacter pylori  

PubMed Central

AIM: To identify genes potentially involved in Helicobacter pylori (H. pylori)-induced gastric carcinogenesis. METHODS: GES-1 cells were co-cultured with H. pylori strains isolated from patients with gastric carcinoma (GC, n = 10) or chronic gastritis (CG, n = 10) for in vitro proliferation and apoptosis assays to identify the most and least virulent strains. These two strains were cagA-genotyped and used for further in vivo carcinogenic virulence assays by infecting Mongolian gerbils for 52 wk, respectively; a broth free of H. pylori was lavaged as control. Genomic profiles of GES-1 cells co-cultured with the most and least virulent strains were determined by microarray analysis. The most differentially expressed genes were further verified using quantitative real-time polymerase chain reaction in GES-1 cells infected with the most and least virulent strains, and by immunohistochemistry in H. pylori positive CG, precancerous diseases, and GC biopsy specimens in an independent experiment. RESULTS: GC-derived H. pylori strains induced a potent proliferative effect in GES-1 cells in co-culture, whereas CG-derived strains did not. The most (from a GC patient) and least (from a CG patient) virulent strains were cagA-positive and negative, respectively. At week 52, CG, atrophy, metaplasia, dysplasia, and GC were observed in 90.0%, 80.0%, 80.0%, 90%, and 60.0%, respectively, of the animals lavaged with the most virulent strain. However, only mild CG was observed in 90% of the animals lavaged with the least virulent strain. On microarray analysis, 800 differentially expressed genes (49 up- and 751 down-regulated), involving those associated with cell cycle regulation, cell apoptosis, cytoskeleton, immune response, and substance and energy metabolisms, were identified in cells co-cultured with the most virulent strain as compared with those co-cultured with the least virulent strain. The six most differentially expressed genes (with a betweenness centrality of 0.1-0.2) were identified among the significant differential gene profile network, including JUN, KRAS, BRCA1, SMAD2, TRAF1, and HDAC6. Quantitative real-time polymerase chain reaction analyses verified that HDAC6 and TRFA1 mRNA expressions were significantly more up-regulated in GES-1 cells co-cultured with the most virulent strain than in those co-cultured with the least virulent strain. Immunohistochemistry of gastric mucosal specimens from H. pylori-positive patients with CG, intestinal metaplasia (IM), dysplasia, and GC showed that moderately positive and strongly positive HDAC6 expression was detected in 21.7% of CG patients, 30.0% of IM patients, 54.5% of dysplasia patients, and 77.8% of GC patients (P < 0.001). The up-regulation of TRAF1 expressions was detected in 34.8%, 53.3%, 72.7%, and 88.9% specimens of CG, IM, dysplasia, and GC, respectively (P < 0.001). CONCLUSION: The overexpression of HDAC6 and TRAF1 in GES-1 cells co-cultured with the GC-derived strain and in H. pylori-positive dysplasia and GC suggests that HDAC6 and TRAF1 may be involved in H. pylori-induced gastric carcinogenesis.

Wang, Fen; Luo, Li-Dan; Pan, Jian-Hua; Huang, Li-Hua; Lv, Hong-Wei; Guo, Qin; Xu, Can-Xia; Shen, Shou-Rong

2012-01-01

83

Dynamic cell culture on porous biopolymer microcarriers in a spinner flask for bone tissue engineering: a feasibility study.  

PubMed

Porous microspherical carriers have great promise for cell culture and tissue engineering. Dynamic cultures enable more uniform cell population and effective differentiation than static cultures. Here we applied dynamic spinner flask culture for the loading and multiplication of cells onto porous biopolymer microcarriers. The abilities of the microcarriers to populate cells and to induce osteogenic differentiation were examined and the feasibility of in vivo delivery of the constructs was addressed. Over time, the porous microcarriers enabled cell adhesion and expansion under proper dynamic culture conditions. Osteogenic markers were substantially expressed by the dynamic cell cultures. The cell-cultured microcarriers implanted in the mouse subcutaneous tissue for 4 weeks showed excellent tissue compatibility, with minimal inflammatory signs and significant induction of bone tissues. This first report on dynamic culture of porous biopolymer microcarriers providing an effective tool for bone tissue engineering. PMID:24652549

Jin, Guang-Zhen; Park, Jeong-Hui; Seo, Seog-Jin; Kim, Hae-Won

2014-07-01

84

Hydrogels as extracellular matrix mimics for 3D cell culture  

Microsoft Academic Search

Methods for culturing mammalian cells ex vivo are increasingly needed to study cell and tissue physiology and to grow replacement tissue for regenerative medicine. Two-dimensional culture has been the paradigm for typical in vitro cell culture; however, it has been demonstrated that cells behave more natively when cultured in three- dimensional environments. Permissive, synthetic hydrogels and promoting, natural hydrogels have

Mark W. Tibbitt; Kristi S. Anseth

2009-01-01

85

Fermentation with immobilized cell cultures.  

PubMed

For the production of monoclonal antibodies and complex recombinant human proteins or glycoproteins a number of immobilized cell culture systems have been developed. The advantages of such cell culture systems are that cells can be kept in small volumes of cell culture fluid and media can be changed continuously if necessary for induction of product synthesis or removal and harvest of metabolic products. Whereas the hollow fiber and the opticell culture systems can be limited in scaling up the microcarrier system, the fluidized bed bioreactor and the solid bed bioreactor are suitable for scaling up. In contrast to the other systems, the solid bed bioreactor requires no special manipulation for anchoring the cells to the wire springs. In situ cleaning is possible and the beads are reusable. With this cell culture fermentation system, production processes for interferon beta, monoclonal antibodies for interferon alfa and recombinant human tissue plasminogen activator were developed. PMID:3285839

Werner, R G; Merk, W; Walz, F

1988-02-01

86

A continuous perfusion microplate for cell culture.  

PubMed

We describe a 96-well microplate with fluidically connected wells that enables the continuous fluid perfusion between wells without the need for external pumping. A single unit in such a perfusion microplate consists of three wells: a source well, a sample (cell culture) well in the middle and a waste well. Fluid perfusion is achieved using a combination of the hydrostatic pressure generated by different liquid levels in the wells and the fluid wicking through narrow strips of a cellulose membrane connecting the wells. There is an excellent correspondence between the observed perfusion flow dynamics and the flow simulations based on Darcy's Law. Hepatocytes (C3A cells) cultured for 4 days in the perfusion microplate with no media exchange in the cell culture well had the same viability as hepatocytes exposed to a daily exchange of media. EOC 20 cells that require media conditioned by LADMAC cells were shown to be equally viable in the adjacent cell culture well of the perfusion microplate with LADMAC cells cultured in the source well. Tegafur, a prodrug, when added to primary human hepatocytes in the source well, was metabolized into a cytotoxic metabolite that kills colon cancer cells (HCT 116) cultured in the adjacent cell culture well; no toxicity was observed when only medium was in the source well. These results suggest that the perfusion microplate is a useful tool for a variety of cell culture applications with benefits ranging from labor savings to enabling in vivo-like toxicity studies. PMID:23344077

Goral, Vasiliy N; Zhou, Chunfeng; Lai, Fang; Yuen, Po Ki

2013-03-21

87

Cultural Environmental Studies  

NSDL National Science Digital Library

The American Studies Program of Washington State University offers this online directory to Websites and resources in cultural environmental studies. The directory presents a subject overview followed by a dozen or more subtopic headings which lead to annotated listings further broken down by subheadings. The site is frequently updated and provides a wealth of links for studying the last two centuries from a cultural studies viewpoint.

88

In vitro biocompatibility of degradable biopolymers in cell line cultures from various ocular tissues: direct contact studies.  

PubMed

Synthetic biodegradable polymers have many potential therapeutic applications. In ophthalmology, biodegradable polymers have been used as viscoelastic agents and surgical implants. Other potential applications include controlled release of drugs and growth factors, gene therapy, and tissue engineering. In the present study, in vitro biocompatibility of three biodegradable polymers, 50:50 PDLGA, 85:15 PDLGA, and Inion GTR membrane was evaluated in comparison to tissue culture polystyrene by investigating cell proliferation and potential acute toxicity by the WST-1 cytotoxicity/cell proliferation test, the ATP test, and the lactate dehydrogenase (LDH) test. Evaluations were conducted with cell line cultures from various ocular tissues, human corneal epithelial cells (HCE), rabbit stromal fibroblasts (SIRC), bovine corneal endothelial cells (BCE), human conjunctival epithelial cells (IOBA-NHC), and human retinal pigment epithelial cells (ARPE-19) by direct contact studies by plating the cells on the polymer film specimens in 96-wells. The proliferation results show that cell lines from various ocular tissues attached and grew on PDLGA 50:50, PDLGA 85:15, and Inion GTR membrane. Cytotoxicity experiments with the LDH and ATP tests showed no or extremely slight toxic adverse effects. These polymers have potential to be used as scaffolds in cell transplantation devices or as surgical implants. PMID:17450585

Huhtala, A; Pohjonen, T; Salminen, L; Salminen, A; Kaarniranta, K; Uusitalo, H

2007-11-01

89

AlgiMatrix(TM) Based 3D Cell Culture System as an In-Vitro Tumor Model for Anticancer Studies  

PubMed Central

Background Three-dimensional (3D) in-vitro cultures are recognized for recapitulating the physiological microenvironment and exhibiting high concordance with in-vivo conditions. Taking the advantages of 3D culture, we have developed the in-vitro tumor model for anticancer drug screening. Methods Cancer cells grown in 6 and 96 well AlgiMatrix™ scaffolds resulted in the formation of multicellular spheroids in the size range of 100–300 µm. Spheroids were grown in two weeks in cultures without compromising the growth characteristics. Different marketed anticancer drugs were screened by incubating them for 24 h at 7, 9 and 11 days in 3D cultures and cytotoxicity was measured by AlamarBlue® assay. Effectiveness of anticancer drug treatments were measured based on spheroid number and size distribution. Evaluation of apoptotic and anti-apoptotic markers was done by immunohistochemistry and RT-PCR. The 3D results were compared with the conventional 2D monolayer cultures. Cellular uptake studies for drug (Doxorubicin) and nanoparticle (NLC) were done using spheroids. Results IC50 values for anticancer drugs were significantly higher in AlgiMatrix™ systems compared to 2D culture models. The cleaved caspase-3 expression was significantly decreased (2.09 and 2.47 folds respectively for 5-Fluorouracil and Camptothecin) in H460 spheroid cultures compared to 2D culture system. The cytotoxicity, spheroid size distribution, immunohistochemistry, RT-PCR and nanoparticle penetration data suggested that in vitro tumor models show higher resistance to anticancer drugs and supporting the fact that 3D culture is a better model for the cytotoxic evaluation of anticancer drugs in vitro. Conclusion The results from our studies are useful to develop a high throughput in vitro tumor model to study the effect of various anticancer agents and various molecular pathways affected by the anticancer drugs and formulations.

Godugu, Chandraiah; Patel, Apurva R.; Desai, Utkarsh; Andey, Terrick; Sams, Alexandria; Singh, Mandip

2013-01-01

90

A comparative study of the cell cycle status and primitive cell adhesion molecule profile of human CD34+ cells cultured in stroma-free versus porcine microvascular endothelial cell cultures.  

PubMed

Porcine microvascular endothelial cells (PMVECs) plus cytokines support a rapid proliferation and expansion of human CD34+CD38- cells that are capable of multilineage engraftment within the bone marrow of a secondary host. CD34+CD38- cells contain the self-renewing, long-term culture-initiating cells (LTC-IC) that are ideal targets for retroviral gene transfer experiments. Previous experiments attempting retroviral infection of CD34+CD38- cells have failed partly because these cells do not enter cell cycle in response to cytokine combinations. In this study, we determined the cell cycle status and the cell adhesion molecule profile on purified CD34+ cells and the CD34+CD38- subset before and after ex vivo expansion on PMVECs. Purified human CD34+ cells were cocultured with PMVECs for 7 days in the presence of optimal concentrations of granulocyte/macrophage-colony-stimulating factor (GM-CSF) + interleukin (IL)-3 + IL-6 + stem cell factor (SCF) + Flt-3 ligand. The total CD34+ population and the CD34+CD38- subset increased 8.4- and 67-fold, respectively, with absolute increases in the number of colony-forming unit-granulocyte macrophage (CFU-GM) (28.2-fold), CFU-Mix (8.7 fold), and burst-forming unit-erythroid (BFU-E) (4.0-fold) progenitor cells. After 7 days of coculture with PMVECs, 44% of the CD34+CD38+ subset were found to be in G1, and 51% were in G2/S/M phase of the cell cycle. More remarkably, 53% of the CD34+CD38- subset were in G1, and 17% were in G2/S/M phase after 7 days of PMVEC coculture. In contrast, only 22% of the CD34+CD38- subset remaining after 7 days of stroma-free culture were in G1, and 6% were in G2/S/M phase. Despite the high level of cellular activation and proliferation induced by PMVEC coculture, the surface expression of adhesion molecules CD11a (LFA-1), CD11b, CD15s (sialyl-Lewis x), CD43, and CD44 (HCAM) on the total CD34+ population was maintained, and the surface expression of CD49d (VLA-4), CD54 (ICAM), CD58, and CD62L (L selectin) increased after ex vivo expansion. In contrast, CD34+ cells expanded on stroma-free cultures showed lower and more variable expression of CD62L and CD15s. These findings demonstrate that the primitive CD34+CD38- subset of marrow progenitor cells can be induced to enter cell cycle and can be significantly expanded ex vivo on a hematopoietic supportive microenvironment (PMVECs) while preserving the expression of cell adhesion molecules that may be important in stem cell homing and engraftment. PMID:10029177

Chute, J P; Saini, A A; Kampen, R L; Wells, M R; Davis, T A

1999-02-01

91

Linear impedance studies of voltage-dependent conductances in tissue cultured chick heart cells.  

PubMed Central

Plateau and pacemaker currents from tissue cultured clusters of embryonic chick heart cells were studied in the time domain, using voltage-clamp steps, and in the frequency domain, using a wide-band noise input superimposed on a steady holding voltage. In the presence of tetrodotoxin to block the sodium channel, a depolarizing voltage step into the plateau range elicited: (a) a rapid (approximately equal to 2 ms) activation of the slow inward current; (b) a subsequent slower (approximately equal to 25 ms) decline in the slow inward current; and (c) activation of a very slow (5 to 10 s) outward current. Impedance studies in this voltage range could clearly resolve two voltage-dependent processes, which appeared to correspond to points b and c above because of their voltage dependence, pharmacology, and time constants. A correlate of point a was also probably present but difficult to resolve owing to the fast time constant of activation for the slow inward channel. At voltages negative to -50 mV a new voltage-dependent process could be resolved, which, because of its voltage dependence and time constant, appeared to represent the pacemaker channel (also termed If or IK2). In the Appendix, linear models of voltage-dependent channels and ion accumulation/depletion are derived and these are compared with our data. Most of the above-mentioned processes could be attributed to voltage-dependent channels with kinetics similar to those observed in time domain, voltage-clamp studies. However, the frequency domain correlate of the decline of the slow inward current was incompatible with channel gating, rather, it appears accumulation/depletion of calcium may dominate the decline in this preparation.

Ebihara, L; Mathias, R T

1985-01-01

92

A patch clamp study of the nicotinic acetylcholine receptor of bovine adrenomedullary chromaffin cells in culture.  

PubMed Central

1. Acetylcholine-induced currents recorded from bovine adrenal medullary chromaffin cells maintained in culture were studied during pressure or ionophoretic applications of ACh, using the 'whole-cell' and 'outside-out' configurations of the patch clamp technique. In standard salines, ACh evoked whole-cell currents of -38 pA to -1 nA at -60 mV, which had a reversal potential (EACh) of -7.1 +/- 0.6 mV. The ACh current-voltage relationship was characteristically linear at negative holding potentials and biphasic at positive holding potentials, displaying a region of almost zero slope conductance between 0 and +40 mV followed by a region of positive slope conductance at more positive potentials. 2. Relative permeation to cations was examined. Substitution of external Na+ by sucrose resulted in a -42 mV shift of EACh for a 10-fold reduction in [Na+]o. Using isotonic substitutions, the permeability ratios (relative to Na+) for monovalent cations were determined to be 1.32 +/- 0.02 for Cs+ (n = 11), 1.03 +/- 0.02 for Li+ (n = 8) and 0.18 +/- 0.02 for Tris+ (n = 7). Elevated external Ca2+ salines were found to shift EACh to more positive potentials, especially in the presence of low external Na+. 3. The nicotinic agonists nicotine, tetramethylammonium and lobeline evoked inward currents in bovine chromaffin cells. In contrast, decamethonium and the muscarinic agonist, methacholine, had no effect. 4. The nicotinic antagonists mecamylamine, trimetaphan, (+)-tubocurarine and hexamethonium caused dose-dependent reductions in the amplitude of ACh-evoked inward currents. The estimated IC50's were 0.25, 0.33, 0.63 and 2.2 microM respectively, for cells voltage clamped at -60 mV. High concentrations (> 2 microM) of the muscarinic antagonist, atropine, also produced a dose-dependent reduction in the amplitude of ACh-induced currents. 5. Inhibition by trimetaphan was voltage independent. With the other drugs the antagonism was voltage sensitive, increasing with membrane hyperpolarization. The voltage sensitivity was most marked for hexamethonium. Neither hexamethonium nor mecamylamine were found to depress ACh-evoked outward currents at concentrations which severely depressed inward currents. In addition to its antagonist actions, (+)-tubocurarine activated unitary currents in these cells and on isolated membrane patches. 6. The results indicate that nicotinic ion channels of bovine chromaffin cells have a similar ionic selectivity to monovalent cations, but that Ca2+ ions permeate the channels to a greater degree than at the motor endplate. The ACh current-voltage relationship resembles that described for other types of 'neuronal' nicotinic receptors.(ABSTRACT TRUNCATED AT 400 WORDS)

Nooney, J M; Peters, J A; Lambert, J J

1992-01-01

93

THE COMPARISON OF TWO VITRO PALATAL ORGAN CULTURE MODELS TO STUDY CELL SIGNALING PATHWAYS DURING PALATOGENESIS  

EPA Science Inventory

This study was performed to determine the best palatal organ culture model to use in evaluating the role of epidermal growth factor (EGF) signaling in the response to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Previous work has shown that TCDD and EGF can induce teratogenic effe...

94

High density cell culture system  

NASA Technical Reports Server (NTRS)

An annular culture vessel for growing mammalian cells is constructed in a one piece integral and annular configuration with an open end which is closed by an endcap. The culture vessel is rotatable about a horizontal axis by use of conventional roller systems commonly used in culture laboratories. The end wall of the endcap has tapered access ports to frictionally and sealingly receive the ends of hypodermic syringes. The syringes permit the introduction of fresh nutrient and withdrawal of spent nutrients. The walls are made of conventional polymeric cell culture material and are subjected to neutron bombardment to form minute gas permeable perforations in the walls.

Spaulding, Glenn F. (inventor)

1994-01-01

95

Biochemical studies on PT523, a potent nonpolyglutamatable antifolate, in cultured cells.  

PubMed

Studies on the mode of action of PT523 [N alpha-(4-amino-4-deoxypteroyl)-N delta-hemiphthaloyl-L-ornithine], a potent nonpolyglutamatable antifolate, were carried out in sensitive and resistant H35 rat hepatoma cell lines in culture, to compare it with other antifolates, including three dihydrofolate reductase (DHFR) inhibitors, i.e., methotrexate (MTX), gamma-fluoro-MTX, and trimetrexate (TMQ), two thymidylate synthase inhibitors, i.e., N10-propargyl-5,8- dideazafolate (PDDF) and 2-desamino-2-methyl-N10-propargyl-5,8-dideazafolate (dmPDDF), and the glycinamide ribonucleotide formyltransferase inhibitor 5,10-dideaza-5,6,7,8-tetrahydrofolate. PT523 was the most active compound in this group against the parental H35 cells, with an IC50 ranging from 2.5 nM for 72 hr of treatment to 0.21 microM for 2 hr of treatment. Sublines resistant to MTX by virtue of a transport defect or a combination of defective transport and increased DHFR activity were resistant to PT523 and MTX but not to PDDF, whereas sublines resistant to fluoropyrimidines by virtue of increased thymidylate synthase activity were resistant to PDDF but not to PT523, TMQ, or MTX. Inhibition of H35 cell growth by PT523 was associated with a concentration- and time-related decrease in de novo dTMP and purine biosynthesis. Growth inhibition by PT523, MTX, and TMQ was prevented by leucovorin or a combination of thymidine (dThd) and hypoxanthine but not by dThd or hypoxanthine alone; in contrast, growth inhibition by dmPDDF was prevented by dThd alone. Intracellular reduced folate polyglutamate pools were markedly altered by PT523 treatment, with the most pronounced effect being an increase in 7,8-dihydrofolate mono- and polyglutamates and a decrease in 5,10-methylene-5,6,7,8-tetrahydrofolate mono- and polyglutamates, 5,6,7,8-tetrahydrofolate mono- and polyglutamates, and 10-formyl-5,6,7,8-tetrahydrofolate mono- and polyglutamates. This pattern was qualitatively similar to that observed with MTX and TMQ but different from that observed with dmPDDF or 5,10-dideaza-5,6,7,8-tetrahydrofolate, which resulted in little or no change in the folate species. Uptake of [3H]MTX and [3H]folinic acid, but not [3H]folic acid, by H35 cells was inhibited in a dose-related manner by PT523, suggesting that penetration of the cell probably involves, at least in part, active transport by the MTX/reduced folate carrier. To determine whether the potent cellular effects of PT523 might be due to chemical or enzymic clevage to N'-(4-amino-4-deoxypteroyl)-L-ornithine, a potent inhibitor of folylpolyglutamate synthetase, the formation of [3H]MTX polyglutamates in CCRF-CEM lymphoblasts pulsed with [3H]MTX after preincubation with PT523 was examined.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:7514264

Rhee, M S; Galivan, J; Wright, J E; Rosowsky, A

1994-04-01

96

Imaging of Cultured Cells by Mass Spectrometry  

Microsoft Academic Search

\\u000a Establishment of an Imaging mass spectrometry (IMS) experimental procedure for cultured cells is an important issue because\\u000a it provides information on localization of various types of biomolecules inside the cell. At present, how to prepare the samples\\u000a from cultured cells for an IMS has been under study. In this section, we present the preparation method for IMS analysis of\\u000a mouse

Hyun Jeong Yang; Yuki Sugiura; Koji Ikegami; Mitsutoshi Setou

97

Dynamized Preparations in Cell Culture  

PubMed Central

Although reports on the efficacy of homeopathic medicines in animal models are limited, there are even fewer reports on the in vitro action of these dynamized preparations. We have evaluated the cytotoxic activity of 30C and 200C potencies of ten dynamized medicines against Dalton's Lymphoma Ascites, Ehrlich's Ascites Carcinoma, lung fibroblast (L929) and Chinese Hamster Ovary (CHO) cell lines and compared activity with their mother tinctures during short-term and long-term cell culture. The effect of dynamized medicines to induce apoptosis was also evaluated and we studied how dynamized medicines affected genes expressed during apoptosis. Mother tinctures as well as some dynamized medicines showed significant cytotoxicity to cells during short and long-term incubation. Potentiated alcohol control did not produce any cytotoxicity at concentrations studied. The dynamized medicines were found to inhibit CHO cell colony formation and thymidine uptake in L929 cells and those of Thuja, Hydrastis and Carcinosinum were found to induce apoptosis in DLA cells. Moreover, dynamized Carcinosinum was found to induce the expression of p53 while dynamized Thuja produced characteristic laddering pattern in agarose gel electrophoresis of DNA. These results indicate that dynamized medicines possess cytotoxic as well as apoptosis-inducing properties.

Sunila, Ellanzhiyil Surendran; Preethi, Korengath Chandran; Kuttan, Girija

2009-01-01

98

Unusual thermolability properties of beta-hexosaminidase: studies of enzyme from cultured cells and clinical implications.  

PubMed

Tay-Sachs disease (TSD) is a neurodegenerative genetic disorder caused by a deficiency of beta-hexosaminidase A (Hex A) activity. To diagnose TSD and to screen for TSD heterozygosity, laboratories use an assay that exploits the differential thermolability of the major beta-hexosaminidase isoenzymes, Hex A and Hex B. At 50-52 degrees C Hex A is labile, and Hex B is stable. We previously noted that the stability of leukocyte Hex B at 52 degrees C varied significantly, depending on the sample concentration in the incubation mixture. We have now examined this phenomenon in enzyme from cultured cells used for prenatal and postnatal diagnostic testing. We found that fibroblast Hex A and Hex B behave similarly to the leukocyte isoenzymes. In control and TSD fibroblasts there was a linear correlation between Hex B thermostability and sample concentration; at lower sample concentrations Hex B was less stable than at higher concentrations. Dialysis of the samples prior to heat treatment did not change the thermostability properties of Hex B, indicating that the change in stability is not due to a soluble low molecular weight substance. Cultured amniotic fluid cell and chorionic villus cell Hex B had a similar, but less pronounced, instability at low sample concentrations. Therefore, the unusual thermolability properties of Hex B, first detected for leukocyte Hex B, were noted in multiple tissues. Based on these data, we suggest that the concentration of cell extract be stringently controlled when the heat-inactivation method is used for the pre- or postnatal diagnosis of TSD, and that supplementation with non-thermolability-based beta-hexosaminidase assays should be employed as needed. PMID:8923943

Prence, E M; Zalewski, I; Natowicz, M R

1996-11-11

99

Aflatoxins in Mammalian Cell Cultures.  

National Technical Information Service (NTIS)

KB and HeLa mammalian tissue culture cells were cultured in the presence of 0.4, 1, and 4 ppm of aflatoxin. The incorporation of labeled uridine into the different RNA components separated by sucrose gradient ultracentrifugation and by methylated albumin ...

R. A. Chung

1968-01-01

100

Cell Culture Models for Neurotoxicology  

Microsoft Academic Search

A range of in vitro cell culture methods are available for neurotoxicology which typically represent one of the two predominant cell types present in the brain, neurons and glial cells. These systems can be used in a two tiered approach, whereby simple cytotoxic models reveal the gross effects of a drug or compound and, subsequently, more complex and subtle assays

Glyn Stacey; Barbara Viviani

2001-01-01

101

Enhanced Cell Culture Growth Rates.  

National Technical Information Service (NTIS)

Major project tasks included assembly of an ultrasonic treatment array; measurement of the cell culture growth rate as a function of media concentration, ultrasonic frequency, and ultrasonic power level and dosage; and evaluation of some physiological ind...

S. R. Taylor

1988-01-01

102

LANTHANUM IN HEART CELL CULTURE  

PubMed Central

Correlation of the localization of La+++ with its effects on Ca++ exchange in cultured rat heart cells is examined with the use of a recently developed technique. 75% of cellular Ca++ is exchangeable and is completely accounted for by two kinetically defined phases. The rapidly exchangeable phase has a t ½ = 1.15 min and accounts for 1 1 mmoles Ca++/kg wet cells or 43% of the exchangeable Ca++ (cells perfused with [Ca++]o = 1 mM) Phase 2 has a t ½ = 19.2 min and accounts for 1.5 mmoles Ca++/kg wet cells or 57% of the exchangeable Ca++. 0.5 mM [La+++]o displaces 0 52 mmoles Ca++/kg wet cells—all from phase 1—and almost completely abolishes subsequent Ca++ influx and efflux The presence of La+++ in the washout converts the washout pattern to a single phase system with a t ½ = 124 min. The effects upon Ca++ exchange are coincident with abolition of contractile tension but regenerative depolarization of the tissue is maintained Electron microscope localization of the La+++ places it exclusively in the external lamina or basement membrane of the cells. The study indicates that negatively charged sites in the basement membrane play a crucial role in the E-C coupling process in heart muscle

Langer, G. A.; Frank, J. S.

1972-01-01

103

Genetic variation of hexosaminidase A and arylsulfatase A activity. Correlation study in amnio-maternal paris of cultured cells  

Microsoft Academic Search

Pairs of cultured amniotic cells and maternal fibroblasts (“feto-maternal pairs”) were studied for hexosaminidase A (HXA) and arylsulfatase A (ASA) activity. These lysosomal enzyme activities are genetically deficient in Tay-Sachs disease and metachromatic leukodystrophy, respectively. After HXA was standardized by relating it to hexosaminidase B (HXB) activity, a feto-maternal correlation coefficient of r=0.51 (n=32; 95% confidence limits 0.197–0.73) was found

K. Harzer; K. Hayashi

1981-01-01

104

Cultured hepatoma cells for the study of enzyme regulation: Induction of ornithine decarboxylase by insulin and asparagine  

Microsoft Academic Search

Summary  The induction and decay of ornithine decarboxylase (ODC) by insulin and asparagine in cultures of H4-II-EC3 (H35) hepatoma\\u000a cells was studied in a modified Waymouth medium in the presence of fetal bovine serum (FBS) and in serum-free media. The insulin\\u000a response was enhanced by the presence of asparagine although the effect of asparagine was not so much on the initial

R. Van Potter; Theresa Ruh Evanson; Debra P. Gayda; James A. Gurr

1984-01-01

105

CELL CULTURE STUDIES WITH THE IMC-HZ-1 NONOCCLUDED VIRUS  

EPA Science Inventory

Studies were conducted on an adventitious agent (Hz-lv) isolated from the IMC-Hz-1 cell line. It appeared identical to the virus first obtained by Granados et al. from a persistent infection of this cell line. Restriction endonuclease digestion of Hz-lv DNA indicated the agent wa...

106

Prostate cell cultures as in vitro models for the study of normal stem cells and cancer stem cells  

Microsoft Academic Search

Current existing therapies for prostate cancer eradicate the majority of cells within a tumor. However, most patients with advanced cancer still progress to androgen-independent metastatic disease that remains essentially incurable by current treatment strategies. Recent evidence has shown that cancer stem cells (CSCs) are a subset of the tumor cells that are responsible for initiating and maintaining the disease. Understanding

J Miki; J S Rhim

2008-01-01

107

A study of murine bone marrow cells cultured in bioreactors which create an environment which simulated microgravity  

NASA Technical Reports Server (NTRS)

Previous research indicated that mouse bone marrow cells could be grown in conditions of simulated microgravity. This environment was created in rotating bioreactor vessels. On three attempts mouse cells were grown successfully in the vessels. The cells reached a stage where the concentrations were doubling daily. Phenotypic analysis using a panel of monoclonal antibodies indicated that the cell were hematopoietic pluripotent stem cells. One unsuccessful attempt was made to reestablish the immune system in immunocompromised mice using these cells. Since last summer, several unsuccessful attempts were made to duplicate these results. It was determined by electron microscopy that the cells successfully grown in 1989 contained virus particles. It was suggested that these virally parasitized cells had been immortalized. The work of this summer is a continuation of efforts to grow mouse bone marrow in these vessels. A number of variations of the protocol were introduced. Certified pathogen free mice were used in the repeat experiments. In some attempts the medium of last summer was used; in others Dexture Culture Medium containing Iscove's Medium supplemented with 20 percent horse serum and 10-6 M hydrocortisone. Efforts this summer were directed solely to repeating the work of last summer. Plans were made for investigations if stem cells were isolated. Immortalization of the undifferentiated stem cell would be attempted by transfection with an oncogenic vector. Selective differentiation would be induced in the stem cell line by growing it with known growth factors and immune response modulators. Interest is in identifying any surface antigens unique to stem cells that would help in their characterization. Another goal was to search for markers on stem cells that would distinguish them from stem cells committed to a particular lineage. If the undifferentiated hematopoietic stem cell was obtained, the pathways that would terminally convert it to myeloid, lyphoid, erythroid, or other cell lines would be studied. Transfection with a known gene would be attempted and then conversion to a terminally identifiable cell.

Lawless, Brother Desales

1990-01-01

108

Comparative Evaluation of Different Cell Lysis and Extraction Methods for Studying Benzo(a)pyrene Metabolism in HT-29 Colon Cancer Cell Cultures  

PubMed Central

Lysis and extraction of cells are essential sample processing steps for investigations pertaining to metabolism of xenobiotics in cell culture studies. Of particular importance to these procedures are maintaining high lysis efficiency and analyte integrity as they influence the qualitative and quantitative distribution of drug and toxicant metabolites in the intra- and extracellular milieus. In this study we have compared the efficiency of different procedures viz. homogenization, sonication, bead beating, and molecular grinding resin treatment for disruption of HT-29 colon cells exposed to benzo(a)pyrene (BaP), a polycyclic aromatic hydrocarbon (PAH) compound and a suspected colon carcinogen. Also, we have evaluated the efficiency of various procedures for extracting BaP parent compound/metabolites from colon cells and culture media prior to High Performance Liquid Chromatography (HPLC) analyses. The extraction procedures include solid phase extraction, solid-supported liquid- liquid extraction, liquid-liquid extraction, and homogeneous liquid- liquid extraction. Our findings showed that bead-beating in combination with detergent treatment of cell pellet coupled with liquid-liquid extraction yielded greater concentrations of BaP metabolites compared to the other methods employed. Our method optimization strategy revealed that disruption of HT-29 colon cells by a combination of mechanical and chemical lysis followed by liquid-liquid extraction is efficient and robust enough for analyzing BaP metabolites from cell culture studies.

Myers, Jeremy N.; Rekhadevi, Perumalla V.; Ramesh, Aramandla

2011-01-01

109

PCR amplification of 16S rDNA from lyophilized cell cultures facilitates studies in molecular systematics  

NASA Technical Reports Server (NTRS)

The sequence of the major portion of a Bacillus cycloheptanicus strain SCH(T) 16S rRNA gene is reported. This sequence suggests that B. cycloheptanicus is genetically quite distinct from traditional Bacillus strains (e.g., B. subtilis) and may be properly regarded as belonging to a different genus. The sequence was determined from DNA that was produced by direct amplification of ribosomal DNA from a lyophilized cell pellet with straightforward polymerase chain reaction (PCR) procedures. By obviating the need to revive cell cultures from the lyophile pellet, this approach facilitates rapid 16S rDNA sequencing and thereby advances studies in molecular systematics.

Wisotzkey, J. D.; Jurtshuk, P. Jr; Fox, G. E.

1990-01-01

110

Hydroxylamido-amino acid complexes of oxovanadium(V). Toxicological study in cell culture and in a zebrafish model.  

PubMed

Oxovanadium(V) complexes [VO(NH(2)O)(2)(val)] and [VO(NH(2)O)(2)(met)] caused inhibition of cell proliferation in two osteoblast cell lines, MC3T3-E1 and UMR106, as well as the viability of zebrafish eggs. In MC3T3-E1, both compounds inhibited cell proliferation (up to ca. 40% at 25 ?M [VO(NH(2)O)(2)(val)] and 25% at 25 ?M [VO(NH(2)O)(2)(met)]). This effect occurs in a dose response manner from 2.5 ?M (p < 0.01) with a more deleterious action of [VO(NH(2)O)(2)(met)]. In UMR106 tumoral cells, [VO(NH(2)O)(2)(val)] inhibited cell proliferation up to 75% from 25 ?M while [VO(NH(2)O)(2)(met)] behaved as an inhibitory agent in the whole range of concentrations (p < 0.01). Similar toxic effects were obtained from morphological studies in cell cultures. Moreover, the IC(50) values for both complexes in culture studies correlated with the IC(50) values obtained with an in vivo model of toxicity (FET test). Besides, the cytotoxicity evaluation in cell culture showed a decrease in mitochondrial activity which was stronger for [VO(NH(2)O)(2)(met)] than for [VO(NH(2)O)(2)(val)] (44% vs. 58% at 25 ?M) in both cell lines (p < 0.001). Genotoxicity assessed by micronuclei induction also showed a stronger effect of [VO(NH(2)O)(2)(met)] in both cell lines. Besides, [VO(NH(2)O)(2)(val)] caused DNA damage determined by comet formation in MC3T3-E1 cells in the range of 2.5-25 ?M, while this effect could not be observed in the osteosarcoma cells. On the other hand, [VO(NH(2)O)(2)(val)] enhanced ROS levels over basal up to 225% and 170% at 100 ?M in MC3T3-E1 and UMR106 cells, respectively (p < 0.01). For [VO(NH(2)O)(2)(met)] a similar situation was observed, suggesting an important role for oxidative stress in the toxicity mechanism of action. Although both complexes showed interesting results that would deserve further drug development [VO(NH(2)O)(2)(val)] was more stable than [VO(NH(2)O)(2)(met)] in the solid state. Therefore, we consider that [VO(NH(2)O)(2)(val)] is a good candidate to be tested in in vivo models as a potential antitumoral agent. PMID:23073485

León, Ignacio E; Di Virgilio, Ana L; Barrio, Daniel A; Arrambide, Gabriel; Gambino, Dinorah; Etcheverry, Susana B

2012-12-01

111

A Three-Dimensional Cell Culture Model to Study the Mechano-Biological Behavior in Periodontal Ligament Regeneration  

PubMed Central

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 examine the effect of mechanical load in vitro. In the current in vitro study, green fluorescent protein labeled periodontal ligament (PDL) cells form rat incisors were embedded in a 3D matrix and exposed to mechanical loading alone, to a chemical stimulus (Emdogain; enamel matrix derivative [EMD]) alone, or a combination of both. Loading consisted of unilateral stretching (8%, 1?Hz) and was applied for 1, 3, or 5 days. Results showed that PDL cells were distributed and randomly oriented within the artificial PDL space in static culture. On mechanical loading, the cells showed higher cell numbers. Moreover, cells realigned perpendicular to the stretching force depending on time and position, with great analogy to natural PDL tissue. EMD application gave a significant effect on growth and upregulated bone sialoprotein (BSP) and collagen type-I (Col-I), whereas Runx-2 was downregulated. This implies that PDL cells under loading might tend to act similar to bone-like cells (BSP and Col-I) but at the same time, react tendon like (Runx-2). The combination of chemical and mechanical stimulation seems possible, but does not show synergistic effects. In this study, a new model was successfully introduced in the field of PDL-related regenerative research. Besides validating the 3D model to mimic an authentic PDL space, it also provided a useful and well-controlled approach to study cell response to mechanical loading and other stimuli.

Oortgiesen, Daniel A.W.; Yu, Na; Bronckers, Antonius L.J.J.; Yang, Fang; Walboomers, X. Frank

2012-01-01

112

Characterization of bovine ciliary pigmented epithelial cells in monolayer culture: An ultrastructural, enzyme histochemical and immunohistochemical study  

Microsoft Academic Search

Monolayer cultures of the pigmented epithelial (PE) cells derived from two regions of the pars plicata of bovine eyes were established and grown up to the third passage. After this passage, the cultures became senescent. During the first three passages, the PE cells lost their pigment granules but developed a distinct cellular polarity by forming junctional complexes at their apical

Michael Eichhorn; Georg Bermbach; Rolf Dermietzel; Elke Lütjen-Drecoll

1993-01-01

113

ES cell-derived neuroepithelial cell cultures.  

PubMed

ES cells have the potential to differentiate into cells from all germ layers, which makes them an attractive tool for the development of new therapies. In general, the differentiation of ES cells follows the concept to first generate immature progenitor cells, which then can be propagated and differentiated into mature cellular phenotypes. This also applies for ES cell-derived neurogenesis, in which the development of neural cells follows two major steps: First, the derivation and expansion of immature neuroepithelial precursors and second, their differentiation into mature neural cells. A common method to produce neural progenitors from ES cells is based on embryoid body (EB) formation, which reveals the differentiation of cells from all germ layers including neuroectoderm. An alternative and more efficient method to induce neuroepithelial cell development uses stromal cell-derived inducing activity (SDIA), which can be achieved by co-culturing ES cells with skull bone marrow-derived stromal cells. Both, EB formation and SDIA, reveal the development of rosette-like structures, which are thought to resemble neural tube- and/or neural crest-like progenitors. The neural precursors can be isolated, expanded and further differentiated into specific neurons and glia cells using defined culture conditions. Here, we describe the generation and isolation of such rosettes in co-culture experiments with the stromal cell line MS5 (2-5). PMID:18704173

Karki, Shreeya; Pruszak, Jan; Isacson, Ole; Sonntag, Kai C

2006-12-01

114

Study of the effects of ultrasonic waves on the reproductive integrity of mammalian cells cultured in vitro  

NASA Technical Reports Server (NTRS)

The effects of monochromatic ultrasonic waves of 0.1, 0.5, 1.0, 2.0 and, 3.3 MHz frequency on the colony-forming ability of mammalian cells (M3-1,V79, Chang's and T-1) cultured in vitro have been studied to determine the nature of the action of ultrasonic energy on biological systems at the cellular level. The combined effect of ultrasound and X-rays has also been studied. It is concluded: (1) Ultrasonic irradiation causes both lethal and sublethal damage. (2) There is a threshold dose rate for lethal effects. (3) The effectiveness of ultrasonic waves in causing cell death probably depends on the frequency and the amplitude of the waves for a given cell line, indicating a possible resonance phenomenon.

Martins, B. I.

1971-01-01

115

Evaluation of silicon nitride as a substrate for culture of PC12 cells: an interfacial model for functional studies in neurons.  

PubMed

Silicon nitride is a biocompatible material that is currently used as an interfacial surface between cells and large-scale integration devices incorporating ion-sensitive field-effect transistor technology. Here, we investigated whether a poly-L-lysine coated silicon nitride surface is suitable for the culture of PC12 cells, which are widely used as a model for neural differentiation, and we characterized their interaction based on cell behavior when seeded on the tested material. The coated surface was first examined in terms of wettability and topography using contact angle measurements and atomic force microscopy and then, conditioned silicon nitride surface was used as the substrate for the study of PC12 cell culture properties. We found that coating silicon nitride with poly-L-lysine increased surface hydrophilicity and that exposing this coated surface to an extracellular aqueous environment gradually decreased its roughness. When PC12 cells were cultured on a coated silicon nitride surface, adhesion and spreading were facilitated, and the cells showed enhanced morphological differentiation compared to those cultured on a plastic culture dish. A bromodeoxyuridine assay demonstrated that, on the coated silicon nitride surface, higher proportions of cells left the cell cycle, remained in a quiescent state and had longer survival times. Therefore, our study of the interaction of the silicon nitride surface with PC12 cells provides important information for the production of devices that need to have optimal cell culture-supporting properties in order to be used in the study of neuronal functions. PMID:24587271

Medina Benavente, Johan Jaime; Mogami, Hideo; Sakurai, Takashi; Sawada, Kazuaki

2014-01-01

116

Stem cell factor and IL-6 do not promote complete maturation of human cultured mast cells from umbilical cord blood cells: an ultrastructural study.  

PubMed

Human mast cells are classified into two phenotypes based on their neutral protease compositions. One type is a tryptase-positive and chymase-positive MCTC cell that is predominant in the skin, another is a tryptase-positive and chymase-negative MCT cell that is predominant in the lung. Cord blood-derived human mast cells cultured in the presence of stem cell factor and interleukin-6 are a mixture of MCTC and MCT at various ratios, as revealed by immunocytochemical staining. We performed an electron microscopic analysis of cord blood-derived human cultured mast cells and found that they were so immature that we could not distinguish MCT and MCTC from their ultrastructural morphology. The response to secretagogues was not the response of MCTC but rather of MCT. Although human cultured mast cells are the most useful cells for use in in vitro experiments, the present culture condition supplemented with stem cell factor and interleukin-6 does not develop fully mature mast cells in vitro. PMID:10960774

Matsushima, Y; Ishikawa, O; Kurosawa, M; Miyachi, Y

2000-09-01

117

An Immunohistochemical Method to Study Breast Cancer Cell Subpopulations and Their Growth Regulation by Hormones in Three-Dimensional Cultures  

PubMed Central

The development of in vitro three-dimensional cell culture matrices offers physiologically relevant alternatives to traditional culture on plastic surfaces. However methods to analyze cell subpopulations therein are poor. Here we present a simple and inexpensive method to analyze cell subpopulations in mixed-cell colonies using standard immunohistochemical (IHC) techniques. Briefly, Matrigel™ blocks are sandwiched between two layers of HistoGel™, hardened by rapid cooling then processed for routine fixation, paraffin embedding, and IHC. We demonstrate the assay using mono- and co-cultured normal human breast, human breast cancer, and transformed mouse stromal cells along with hormone treated breast cancer cells. Judicious selection of specific antibodies allows different cell types within heterotypic colonies to be identified. A brief pulse of bromodeoxyuridine in living colonies allows proliferation of cell subpopulations to be quantified. This simple assay is useful for multiple cell types, species, and conditions.

Pinto, Mauricio P.; Jacobsen, Britta M.; Horwitz, Kathryn B.

2011-01-01

118

Predicting In Vivo Efficacy of Potential Restenosis Therapies by Cell Culture Studies: Species-Dependent Susceptibility of Vascular Smooth Muscle Cells  

PubMed Central

Although drug-eluting stents (DES) are successfully utilized for restenosis therapy, the development of local and systemic therapeutic means including nanoparticles (NP) continues. Lack of correlation between in vitro and in vivo studies is one of the major drawbacks in developing new drug delivery systems. The present study was designed to examine the applicability of the arterial explant outgrowth model, and of smooth muscle cells (SMC) cultures for prescreening of possible drugs. Elucidation of different species sensitivity (rat, rabbit, porcine and human) to diverse drugs (tyrphostins, heparin and bisphsophonates) and a delivery system (nanoparticles) could provide a valuable screening tool for further in vivo studies. The anticipated sensitivity ranking from the explant outgrowth model and SMC mitotic rates (porcine>rat>>rabbit>human) do not correlate with the observed relative sensitivity of those animals to antiproliferative therapy in restenosis models (rat?rabbit>porcine>human). Similarly, the inhibitory profile of the various antirestenotic drugs in SMC cultures (rabbit>porcine>rat>>human) do not correlate with animal studies, the rabbit- and porcine-derived SMC being highly sensitive. The validity of in vitro culture studies for the screening of controlled release delivery systems such as nanoparticles is limited. It is suggested that prescreening studies of possible drug candidates for restenosis therapy should include both SMC cell cultures of rat and human, appropriately designed with a suitable serum.

Hila, Epstein; Rabinovich, Laura; Banai, Shmuel; Elazar, Vicktoria; Gao, Jianchuan; Chorny, Michael; Danenebrg, Haim D; Golomb, Gershon

2008-01-01

119

A study on the susceptibility of minipig kidney (MPK) and rabbit kidney (RK13) cell line cultures to the lapinized Chinese strain of hog cholera virus.  

PubMed

The susceptibility of two established cell lines of pig (MPK = minipig kidney) and rabbit (RK13 = rabbit kidney) origin to the lapinized Chinese (LC) strain of hog cholera virus (HCV) was studied. Spleen cells from rabbits infected with the virus under study were inoculated to cell cultures of either MPK and RK13 cells and subsequent passages were made by culturing the trypsinized infected cells with the normal cells. Only the MPK cell line appeared to be susceptible to virus replication. Since no cytopathic effects (CPE) were observed, the presence of the viral antigen in the inoculated cultures was detected by immunofluorescence tests. The virulence of the virus for rabbits was enhanced after its cultivation in MPK cell cultures. When the MPK cell culture system adapted virus was tested in neutralization trials in the presence of an HCV reference immune serum it was found that the virus did not modify its antigenic structure in any extent. Finally, the culture adapted virus appeared to be more immunogenic for rabbits than the original rabbits adapted virus. Based on these results, it seems reasonable to suggest the use of MPK cell line for the propagation of the LC strain of HCV as an alternative to the use of rabbits for the preparation of HCV vaccine. PMID:3063925

Rivero, V B; Gualandi, G L; Buonavoglia, C; Mortarino, P

1988-10-01

120

Phenotypic change of human cultured meningioma cells.  

PubMed

One objection to using cell cultures for studying the proliferation of tumors is the potential for phenotypic changes that may occur in vitro. Here, we compared the antigen pattern expression of cultured meningioma cells with that of the primary tumor. Cell cultures established from 9 intracranial meningiomas and deparaffinized sections of the resected tumors were analyzed for immunophenotyping with the following antibodies: vimentin, cytokeratin, epithelial membrane antigen, S-100, neuron-specific enolase, synaptophisin, factor VIII-related antigen, CD4, CD31, CD34, CD45RB, CD68-PGM1, CD68-KP, and myeloid/histiocyte antigen (MAC387). Overall, the cultured meningioma cells retained the main feature of the primary tumor, being positive both for mesenchymal antigens and for epithelial antigens. Interestingly, the cultured meningioma cells abundantly expressed the CD68 antigens at early passage. The CD68 antigens, which are normally found on hematopoietic cells like macrophages and monocytes, were not detectable on meningioma cells in situ. Our results show that phenotypic changes on human meningioma cells may occur in vitro. This phenomenon suggests caution when transposing the in vitro results to the in vivo condition. PMID:11131990

Pallini, R; Casalbore, P; Mercanti, D; Maggiano, N; Larocca, L M

2000-08-01

121

Lycopene in atherosclerosis prevention: an integrated scheme of the potential mechanisms of action from cell culture studies.  

PubMed

Increasing evidence suggests that lycopene may protect against atherosclerosis, although, the exact mechanism(s) is still unknown. Because lycopene is an efficient antioxidant, it has been proposed for a long time that this property may be responsible for its beneficial effects. Consistent with this, the carotenoid has been demonstrated to inhibit ROS production in vitro and to protect LDL from oxidation. However, recently, other mechanisms have been evoked and include: prevention of endothelial injury; modulation of lipid metabolism through a control of cholesterol synthesis and oxysterol toxic activities; reduction of inflammatory response through changes in cytokine production; inhibition of smooth muscle cell proliferation through regulation of molecular pathways involved in cell proliferation and apoptosis. Focusing on cell culture studies, this review summarizes the experimental evidence for a role of lycopene in the different phases of atherosclerotic process. PMID:20599665

Palozza, Paola; Parrone, Nadia; Simone, Rossella E; Catalano, Assunta

2010-12-01

122

TRANSFORMATION OF MONOCYTES IN TISSUE CULTURE INTO MACROPHAGES, EPITHELIOID CELLS, AND MULTINUCLEATED GIANT CELLS: An Electron Microscope Study  

Microsoft Academic Search

The scqucntial transformation of chickcn monocytcs into macrophages, cpithelioid cells, and multinucleatcd giant cells in vitro was studied by electron microscopy after fixation and cmbcdment in situ. The following changes occur. In the nucleus, margination of chro- matin, cvidcnt in monocytes, decreases in later forms. Nucleoli become more complcx and nuclear pores increase in number. In cytoplasm, a progressive increase

JERRY S. SUTTON; LEON WEISS

1966-01-01

123

Development of a mouse model for studying the effect of embryo culture on embryonic stem cell derivation.  

PubMed

For most of the derived human embryonic stem cell (ESC) lines thus far, the majority of human embryos used have been frozen in liquid nitrogen at or prior to the compacting stage for up to 10 years before human ESC derivation. As such they were grown in media that were relatively simple in their formulation compared with those used today. Here we report that culture of mouse embryos in media similar to these produces blastocysts in which both the inner cell mass cell number and the number of ESC progenitor cells (epiblast cells) in the inner cell mass are reduced compared with blastocysts cultured in a purpose-designed sequential (G1/G2) system commonly used today. Embryos cultured in a simple medium were less likely to attach and generate outgrowths. Further, these outgrowths had increased metabolic activity, which has been linked to differentiation, and altered gene expression. Culture of embryos in a simple medium to the compacting stage followed by culture in G2 to the blastocyst stage reduced some of these effects. However, none were improved to the level seen for culture in G1/G2. These results highlight the influence of embryo culture on embryo quality and pluripotency, which is a key factor in determining ESC isolation efficiencies. PMID:21105769

Campbell, Jared M; Mitchell, Megan; Nottle, Mark B; Lane, Michelle

2011-09-01

124

CALCIUM OXALATE CRYSTAL ATTACHMENT TO CULTURED KIDNEY EPITHELIAL CELL LINES  

Microsoft Academic Search

PurposeCultured kidney epithelial cell lines have frequently been used in urolithiasis research, and in particular in studies related to the interactions between stone crystals and cell membranes. There is evidence that when epithelial cell lines are transformed or serially passed to immortalize them, they experience changes in both cell physiology and morphology. Stone research utilizing cell cultures is frequently necessary

MICHAEL W. BIGELOW; JOHN H. WIESSNER; JACK G. KLEINMAN; NEIL S. MANDEL

1998-01-01

125

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

PubMed

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 coating of PGA scaffolds; cellularity was inversely proportional to the concentration of PLLA used. PLLA coating did not prevent dissolution of the PGA scaffolds. All cell scaffold types and culture conditions produced non-uniform cellular distribution. Discussion/Conclusion. FLS-seeding of PGA scaffolds cultured in a rotating bioreactor resulted in the most optimal cell and matrix characteristics seen in this study. Cells grew only in the pores of the OPLA sponge, and could not adhere to the PLLA coating of PGA scaffold, due to the hydrophobic property of PLA. While PGA culture in a bioreactor produced measureable GAG, no culture technique produced visible collagen. For this reason, and due to the dissolution of PGA scaffolds, the culture conditions and scaffolds described here are not recommended for inducing fibrochondrogenesis in equine FLS for meniscal tissue engineering. PMID:24765587

Warnock, Jennifer J; Fox, Derek B; Stoker, Aaron M; Beatty, Mark; Cockrell, Mary; Janicek, John C; Cook, James L

2014-01-01

126

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

PubMed Central

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 coating of PGA scaffolds; cellularity was inversely proportional to the concentration of PLLA used. PLLA coating did not prevent dissolution of the PGA scaffolds. All cell scaffold types and culture conditions produced non-uniform cellular distribution. Discussion/Conclusion. FLS-seeding of PGA scaffolds cultured in a rotating bioreactor resulted in the most optimal cell and matrix characteristics seen in this study. Cells grew only in the pores of the OPLA sponge, and could not adhere to the PLLA coating of PGA scaffold, due to the hydrophobic property of PLA. While PGA culture in a bioreactor produced measureable GAG, no culture technique produced visible collagen. For this reason, and due to the dissolution of PGA scaffolds, the culture conditions and scaffolds described here are not recommended for inducing fibrochondrogenesis in equine FLS for meniscal tissue engineering.

Fox, Derek B.; Stoker, Aaron M.; Beatty, Mark; Cockrell, Mary; Janicek, John C.; Cook, James L.

2014-01-01

127

Ferulic acid antioxidant protection against hydroxyl and peroxyl radical oxidation in synaptosomal and neuronal cell culture systems in vitro: structure-activity studies  

Microsoft Academic Search

In this study, free radical scavenging abilities of ferulic acid in relation to its structural characteristics were evaluated in solution, cultured neurons, and synaptosomal systems exposed to hydroxyl and peroxyl radicals. Cultured neuronal cells exposed to the peroxyl radical initiator AAPH die in a dose-response manner and show elevated levels of protein carbonyls. The presence of ferulic acid or similar

Jaroslaw Kanski; Marina Aksenova; Antonia Stoyanova; D. Allan Butterfield

2002-01-01

128

Use of an insect cell culture growth medium to isolate bacteria from horses with effusive, fibrinous pericarditis: A preliminary study  

Microsoft Academic Search

Effusive, fibrinous pericarditis is an uncommon disease entity in horses. In 2001, pericarditis occurred in conjunction with an epizootic in central Kentucky that was associated with exposure to eastern tent caterpillars (ETCs). Bacterial isolation from equine pericardial fluid samples was attempted using an insect cell culture growth medium (ICCGM). Using previously cultured, stored frozen samples from four horses with fibrinous

Samuel L. Jones; Amy Valenzisi; Sushama Sontakke; Kimberly A. Sprayberry; Ricardo Maggi; Barbara Hegarty; Edward Breitschwerdt

2007-01-01

129

Development of an Innovative 3D Cell Culture System to Study Tumour - Stroma Interactions in Non-Small Cell Lung Cancer Cells  

PubMed Central

Introduction We describe a novel 3D co-culture model using non-small cell lung cancer (NSCLC) cell lines in combination with lung fibroblasts. This model allows the investigation of tumour-stroma interactions and addresses the importance of having a more in vivo like cell culture model. Methods Automation-compatible multi-well hanging drop microtiter plates were used for the production of 3D mono- and co-cultures. In these hanging drops the two NSCLC cell lines A549 and Colo699 were cultivated either alone or co-cultured with lung fibroblasts. The viability of tumour spheroids was confirmed after five and ten days by using Annexin V/Propidium Iodide staining for flow-cytometry. Tumour fibroblast spheroid formation was characterized by scanning electron microscope (SEM), semi-thin sections, fluorescence microscope and immunohistochemistry (IHC). In addition to conventional histology, protein expression of E-Cadherin, vimentin, Ki67, fibronectin, cytokeratin 7 and ?-smooth muscle actin (?-SMA) was investigated by IHC. Results Lower viability was observed in A549 monocultures compared to co-cultures, whereas Colo699 monocultures showed better viability compared to co-cultures. Ki67 expression varied significantly between mono- and co-cultures in both tumour cell lines. An increase of vimentin and decreased E-Cadherin expression could be detected during the course of the cultivation suggesting a transition to a more mesenchymal phenotype. Furthermore, the fibroblast cell line showed an expression of ?-SMA only in co-culture with the cancer cell line A549, thereby indicating a mesenchymal to mesenchymal shift to an even more myofibroblast phenotype. Conclusion We demonstrate that our method is a promising tool for the generation of tumour spheroid co-cultures. Furthermore, these spheroids allow the investigation of tumour-stroma interactions and a better reflection of in vivo conditions of cancer cells in their microenvironment. Our method holds potential to contribute to the development of anti-cancer agents and support the search for biomarkers.

Amann, Arno; Zwierzina, Marit; Gamerith, Gabriele; Bitsche, Mario; Huber, Julia M.; Vogel, Georg F.; Blumer, Michael; Koeck, Stefan; Pechriggl, Elisabeth J.; Kelm, Jens M.; Hilbe, Wolfgang; Zwierzina, Heinz

2014-01-01

130

Studies of immunomodulating actions of carotenoids. I. Effects of ??carotene and astaxanthin on murine lymphocyte functions and cell surface marker expression in in vitro culture system  

Microsoft Academic Search

The immunomodulating effects of carotenoids (??carotene and astaxanthin) on mouse lymphocytes were studied in in vitro culture system by use of assay for mitogen responses of spleen cells, thymocyte proliferation, interleukin 2 production, and antibody (Ab) production in vitro in response to sheep red blood cells. Changes of cell surface markers on spleen lymphocytes including la antigen (Ag), surface immunoglobulin,

Harumi Jyonouchi; Roberta J. Hill; Yoshifumi Tomita; Robert A. Good

1991-01-01

131

Clonal Propagation of Chinese Tallow via Cultured Tissues and Cells, (Feasibility Study). Phase 1 Final Report.  

National Technical Information Service (NTIS)

The project concerns the development of Chinese Tallow as a cash crop, using aseptic culture techniques to facilitate improvement and cultivation of currently available stock. The overall goal of the Phase 1 work was to assess the feasibility of applying ...

A. K. Krikorian H. W. Scheld G. N. Cameron N. B. Bell L. J. Lester

1983-01-01

132

Cell death pattern of a varicose vein organ culture model.  

PubMed

The study aimed to investigate the viability of a varicose vein (VV) organ culture model by assessing cell death pattern. To assess pattern of cell death with time, VV organ cultures were incubated for up to 14 days with regular medium changed. To assess viability, cell death of VV organ cultures treated with sodium azide and their untreated counterparts was assayed. Increased cell death was measured in VV organ cultures from day 0 to 2. Cell death decreased gradually after day 2 and plateaued from day 8 to 14.VV organ cultures treated with sodium azide demonstrated significantly more cell death in tissue (P = 0.001). Cell death measured in cultures treated with sodium azide continued to increase until day 7. In conclusion, this study demonstrated the viability of a VV organ culture model with most cell death occurred within the first two days and then declined to a relatively low level. PMID:23526103

Lim, Chung S; Kiriakidis, Serafim; Paleolog, Ewa M; Davies, Alun H

2013-06-01

133

Thiolated chitosan nanoparticles: transfection study in the Caco-2 differentiated cell culture  

NASA Astrophysics Data System (ADS)

The aim of this study was to monitor the expression of secreted protein in differentiated Caco-2 cells after transfection with nanoparticles, in order to improve gene delivery. Based on unmodified chitosan and thiolated chitosan conjugates, nanoparticles with the gene reporter pSEAP (recombinant Secreted Alkaline Phosphatase) were generated at pH 4.0. Transfection studies of thiolated chitosan in Caco-2 cells during the exponential growth phase and differentiation growth phase of the cells led to a 5.0-fold and 2.0-fold increase in protein expression when compared to unmodified chitosan nanoparticles. The mean particle size for both unmodified chitosan and cross-linked thiolated chitosan nanoparticles is 212.2 ± 86 and 113.6 ± 40 nm, respectively. The zeta potential of nanoparticles was determined to be 7.9 ± 0.38 mV for unmodified chitosan nanoparticles and 4.3 ± 0.74 mV for cross-linked thiolated chitosan nanoparticles. Red blood cell lysis evaluation was used to evaluate the membrane damaging properties of unmodified and thiolated chitosan nanoparticles and led to 4.61 ± 0.36% and 2.29 ± 0.25% lysis, respectively. Additionally, cross-linked thiolated chitosan nanoparticles were found to exhibit higher stability toward degradation in gastric juices. Furthermore the reversible effect of thiolated chitosan on barrier properties was monitored by measuring the transepithelial electrical resistance (TEER) and is supported by immunohistochemical staining for the tight junction protein claudin. According to these results cross-linked thiolated chitosan nanoparticles have the potential to be used as a non-viral vector system for gene therapy.

Martien, Ronny; Loretz, Brigitta; Sandbichler, Adolf Michael; Bernkop Schnürch, Andreas

2008-01-01

134

Cytotoxicity study on SH?SY5Y cells cultured at high glucose levels and treated with bupivacaine.  

PubMed

The aim of this study was to investigate susceptibility to the neurotoxicity of local anesthetic agents in a model of gestational diabetes mellitus (GDM). SH-SY5Y cells were cultured at different concentrations of glucose and subsequently treated with 1 mmol/l bupivacaine for 6 h. Reactive oxygen species (ROS) production and apoptosis were assessed using flow cytometry in each group of cells. The MTT method was utilized to detect cell survival, and western blot analysis was used to examine changes in 78 kDa glucose?regulated protein (GRP78) levels in neuronal cells. In all groups, levels of ROS production, cell survival and GRP78 expression were significantly different (P<0.01) following the addition of various concentrations of glucose and bupivacaine, as well as for the interaction between different concentrations of the anesthetic agents, demonstrating a statistically significant difference. In conclusion, the susceptibility of SH-SY5Y cells to the neurotoxicity of local anesthetic agents was enhanced in a model of GDM. PMID:24317184

Li, Yawen; Xu, Shiyuan; Zhang, Qingguo; Li, Le; Lai, Luying; Zheng, Ting; Su, Jiaoling; Yang, Naimei; Li, Yuantao

2014-02-01

135

A comprehensive study on optimization of proliferation and differentiation potency of bone marrow derived mesenchymal stem cells under prolonged culture condition.  

PubMed

Bone marrow derived stem cells (BMSC) have paved way to clinical approaches for its utilization in a variety of diseases due to its ease of isolation combined with its multilineage differentiation capacity. However, the applicability of BMSC is not successful due to the lesser number of nucleated cells obtained from large samples. Hence, culture expansion of BMSC is a prerequisite, as high numbers of stem cells are needed to meet the standards of clinical advancement. There are attempts on optimizing culture condition for large scale production of BMSC. It was believed that, prolonged culture of BMSC is difficult since they tend to lose their characteristics and differentiation potential. Hence, our study aims to determine whether BMSCs could retain its proliferative and differentiation capacity in prolonged in vitro culture by a comparative study on extensive culturing of BMSC with the following four media, DMEM LG (DMEM-Low Glucose), DMEM KO (DMEM-Knock Out), Alpha MEM (Alpha Minimal Essential Medium), DMEM F 12. We found that two samples among the three cultured tend to lose their property in long term culturing. Besides, we also found that DMEM LG and Alpha MEM were the optimal media for in vitro culturing of BMSC. Overall, it was concluded that BMSC can be cultured until passage 15 without losing its characteristics. However, its potency beyond passage 15 has to be further elucidated for utilization of the ex vivo expanded BMSC for subsequent cellular therapies. PMID:22729554

Dhanasekaran, M; Indumathi, S; Lissa, R P; Harikrishnan, R; Rajkumar, J S; Sudarsanam, D

2013-03-01

136

Hepatitis E virus cell culture models.  

PubMed

Early studies reported the propagation of hepatitis E virus (HEV) in either primary hepatocytes or several established cell lines, but replication was inefficient. Efficient cell culture systems for HEV in PLC/PRF/5 and A549 cells have recently been established, using inoculum of fecal suspensions with high HEV loads, originally obtained from patients with genotype 3 HEV (the JE03-1760F strain, 2.0×10(7) copies/ml) or genotype 4 HEV (the HE-JF5/15F strain, 1.3×10(7) copies/ml), and many generations were successfully propagated in serial passages of culture supernatant. In addition, a full-length infectious cDNA clone (pJE03-1760F/wt) of the JE03-1760F strain was constructed, which can replicate efficiently in PLC/PRF/5 and A549 cells. A derivative ORF3-deficient mutant revealed that the ORF3 protein of HEV is responsible for virion egress from infected cells and is present on the surface of released HEV particles, which is associated with lipids. Various HEV strains with high loads of ?10(5) copies/ml in circulating blood were also propagated efficiently in PLC/PRF/5 and A549 cells. This paper reviews the road map toward the development of efficient cell culture systems for a wide variety of HEV strains and introduces the current knowledge on virion egress obtained by cell culture models. PMID:21316402

Okamoto, Hiroaki

2011-10-01

137

A Comparative Study on Morphochemical Properties and Osteogenic Cell Differentiation within Bone Graft and Coral Graft Culture Systems  

PubMed Central

The objective of this study was to compare the morphological and chemical composition of bone graft (BG) and coral graft (CG) as well as their osteogenic differentiation potential using rabbit mesenchymal stem cells (rMSCs) in vitro. SEM analysis of BG and CG revealed that the pores in these grafts were interconnected, and their micro-CT confirmed pore sizes in the range of 107-315 µm and 103-514 µm with a total porosity of 92% and 94%, respectively. EDS analysis indicated that the level of calcium in CG was relatively higher than that in BG. FTIR of BG and CG confirmed the presence of functional groups corresponding to carbonyl, aromatic, alkyl, and alkane groups. XRD results revealed that the phase content of the inorganic layer comprised highly crystalline form of calcium carbonate and carbon. Atomic force microscopy analysis showed CG had better surface roughness compared to BG. In addition, significantly higher levels of osteogenic differentiation markers, namely, alkaline phosphatase (ALP), Osteocalcin (OC) levels, and Osteonectin and Runx2, Integrin gene expression were detected in the CG cultures, when compared with those in the BG cultures. In conclusion, our results demonstrate that the osteogenic differentiation of rMSCs is relatively superior in coral graft than in bone graft culture system.

Puvaneswary, Subramaniam; Balaji Raghavendran, Hanumantha Rao; Ibrahim, Nurul Syuhada; Murali, Malliga Raman; Merican, Azhar Mahmood; Kamarul, T.

2013-01-01

138

Adaptation of Ehrlichia sennetsu to canine blood monocytes: preliminary structural and serological studies with cell culture-derived Ehrlichia sennetsu.  

PubMed Central

Ehrlichia sennetsu, the causative agent of human sennetsu rickettsiosis, was successfully propagated in primary canine blood monocyte cultures. The growth cycle of this organism appears to be similar to that of Ehrlichia canis. The antigen derived from our E. sennetsu cultures was used to develop an indirect fluorescent antibody test for detection and titration of serum antibodies to the organism. Using this test system, we found that five human serum samples obtained from patients clinically diagnosed as having sennetsu rickettsiosis were positive for anti-E. sennetsu antibodies. In addition, 29% of the serum samples obtained from 200 patients having a fever of unknown origin and residing in various regions of Malaysia were also serologically positive. All sera from apparently healthy individuals were negative in the test. Dogs inoculated with cell culture-adapted E. sennetsu developed a significant specific antibody titer to E. sennetsu, and the organism was subsequently isolated from their blood. These animals showed no clinical evidence of disease. The possibility of a higher prevalence of human sennetsu rickettsiosis in Southeast Asia and the potential usefulness of the canine model for studies of human sennetsu rickettsiosis are discussed. Images

Holland, C J; Ristic, M; Huxsoll, D L; Cole, A I; Rapmund, G

1985-01-01

139

Wound Coverage by Cultured Skin Cells.  

National Technical Information Service (NTIS)

The aim was to confirm and extend in vitro and in vivo studies reported last year and develop new means for wound treatment. For the studies in vitro we used different tissue culture techniques. Quantitative data were obtained by cell counts and incorpora...

M. Eisinger

1987-01-01

140

Photoreceptor-like cells from reprogramming cultured mammalian RPE cells  

PubMed Central

Purpose Previous studies showed that chick retinal pigment epithelium (RPE) cells can be reprogrammed by a specific gene to take on the path of photoreceptor differentiation. In this study, we tested whether this reprogramming scheme could be applied to mammalian RPE cells. Methods Human RPE cell lines ARPE-19, a spontaneously transformed line of RPE cells derived from a 19-year-old person, and hTERT-RPE1, a telomerase-immortalized RPE cell line derived from a 1-year-old person, were commercially obtained and cultured as recommended. Primary RPE cell cultures were established using RPE isolated from 3- to 6-month-old pig and postnatal day 5 mouse. Cultured cells were transduced with a virus expressing neuroD, neurogenin1 (ngn1), or ngn3, basic helix-loop-helix (bHLH) genes previously identified as capable of inducing RPE-to-photoreceptor reprogramming in the chick system. Alternatively, cells in the culture were transfected chemically or physically through electroporation with vector DNA expressing one of the three genes. The cultures were then analyzed for RPE-to-photoreceptor reprogramming with in situ hybridization and/or immunostaining for photoreceptor gene expression. Results Both hTERT-RPE1 and ARPE-19 cultures gave rise to cells bearing markers of photoreceptors after transduction or transfection with vehicles expressing neuroD or ngn1. The new cells expressed genes encoding photoreceptor proteins, including interphotoreceptor retinoid-binding protein IRBP), recoverin, retinal cone arrestin 3, transducin ?-subunit, Cone-rod homeobox protein (Crx), and red opsin. They displayed morphologies resembling differentiating photoreceptor cells. In primary porcine and mouse RPE cell cultures, transduction with lenti virus (Lvx-IRES-ZsGreen1) expressing ngn1 or ngn3 resulted in the emergence of ZsGreen1+ cells that exhibited morphologies reminiscent of differentiating photoreceptor cells. Immunochemistry showed that some ZsGreen1+ cells were positive for neural marker microtubule-associated protein 2 (Map2) and photoreceptor hallmark proteins red opsin and rhodopsin. Conclusions The results suggest that cells in human RPE cell lines and in primary cultures of porcine and mouse RPE respond to gene-induced reprogramming by giving rise to photoreceptor-like cells. The responsiveness of primary RPE cells, especially those from porcine cells, enhances the biologic feasibility of exploring RPE-to-photoreceptor reprogramming for in situ mammalian photoreceptor replacement without cell transplantation.

Yan, Run-Tao; Huang, Jian; Guidry, Clyde; Wang, Shu-Zhen

2013-01-01

141

Protein Inhibition by Microinjection and RNA-Mediated Interference in Tissue Culture Cells: Complementary Approaches to Study Protein Function  

PubMed Central

A major goal in cell biology is to understand the molecular mechanisms of the biological process under study, which requires functional information about the roles of individual proteins in the cell. For many non-genetic model organisms researchers have relied on the use of inhibitory reagents, such as antibodies that can be microinjected into cells. More recently, the advent of RNA-mediated interference (RNAi) has allowed scientists to knockdown individual proteins and to examine the consequences of the knockdown. In this chapter we present a comparison between microinjection of inhibitory reagents and RNAi for the analysis of protein function in mammalian tissue culture cells, providing both a description of the techniques as well as a discussion of the benefits and drawbacks of each approach. In addition, we present a strategy to employ RNAi for organisms without a sequenced genome. While the focus of our research is on the organization of the mitotic spindle during cell division and thus the examples utilized are from that system, the approaches described here should be readily applicable to multiple experimental models.

Stout, Jane R.; Rizk, Rania S; Walczak, Claire E.

2010-01-01

142

Integration of cell culture and microfabrication technology.  

PubMed

Recent progress in cell culture and microfabrication technologies has contributed to the development of cell-based biosensors for the functional characterization and detection of drugs, pathogens, toxicants, and odorants. The cell-based biosensors are composed of two transducers, where the primary transducer is cellular and the secondary transducer is typically electrical. Advances in gene manipulation and cell culture techniques have contributed to the development of the cell as a transducer, while microfabrication techniques have been applied to the development of integrating the cell with the second transducer. Cellular patterning using microfabrication techniques is essential for cell-based biosensors, cell culture analogues, tissue engineering, and fundamental studies of cell biology. The photolithographic technique is highly developed and has been widely used for patterning cells. Recently, a set of alternative techniques, largely based on soft lithoghraphy, has been developed for biological applications. Those techniques include microcontact printing, microfluidic patterning using microchannels, and laminar flow patterning. A classical metallic stencil patterning method has been improved by employing a rubber-like stencil. These cellular micropatterning techniques have been usefully employed to understand questions in fundamental cell biology, especially cellular interactions with various materials and other cells. Using these micropatterning tecchniques and insights into the interaction of cellular biology with surfaces, a wide array of biosensors have been developed. In this manuscript examples of cell-based biosensors are described. Neurons have a great potential for use in a cell-based biosensor because they are electrically excitable cells, from which electrical signals are generated with the binding of detecting molecules. Consequently, the electrical signals generated in the cell can be determined in a noninvasive manner. A microphysiometer is a device to detect functional responses from cells by measuring the change of extracellular pH. The main application of the microphysiometer is the analysis of functional responses of cells upon receptor stimulation. Development of a microscale cell culture analogue system, an in vitro animal or human surrogate, is another promising area using cell culture and microfabrication technologies. Such devices are potentially very useful in the fields of toxicology and drug testing because they may increase the accuracy of in vitro predictions, simplify testing procedures, and reduce the cost of such tests, allowing many more tests to be done with a limited set of resources. PMID:12675556

Park, Tai Hyun; Shuler, Michael L

2003-01-01

143

Isoniazid Proliposome Powders for Inhalation--Preparation, Characterization and Cell Culture Studies  

PubMed Central

The aims of this study were to develop proliposome powders containing isoniazid (INH) in a dry powder aerosol form. INH-proliposome powders were prepared by a spray drying method. Proliposome physicochemical properties were determined using cascade impactor, X-ray diffraction and differential scanning calorimetry. The toxicity of proliposomes to respiratory-associated cell lines and its potential to provoke immunological responses from alveolar macrophages (AM) were determined. Free INH and INH-proliposome bioactivities were tested in vitro and in AM infected with Mycobacterium bovis (M. bovis). Aerosolization properties of INH-proliposome powders at 60 L/min, the powders showed mass median aerodynamic diameters of 2.99–4.92 ?m, with fine particle fractions (aerosolized particles less than 4.4 ?m) of 15–35%. Encapsulation of INH was 18–30%. Proliposome formulations containing INH to mannitol ratios of 4:6 and 6:4 exhibited the greatest overlapping peak between the drug and mannitol. INH-proliposomes were evidently nontoxic to respiratory-associated cells, and did not activate AM to produce inflammatory mediators—including interleukin-1? (IL-1?), tumor necrosis factor-? (TNF-?), and nitric oxide—at a toxic level. The efficacy of INH-proliposome against AM infected with M. bovis was significantly higher than that of free INH (p < 0.05). INH-proliposomes are potential candidates for an alternative tuberculosis treatment.

Rojanarat, Wipaporn; Changsan, Narumon; Tawithong, Ekawat; Pinsuwan, Sirirat; Chan, Hak-Kim; Srichana, Teerapol

2011-01-01

144

Trends in cell culture technology.  

PubMed

Dynamic macroscale bioreactor systems are the most recent breakthrough in cell culture technology. This major achievement, at the beginning of the 21st century, fortunately coincided with an embarrassing gap in the measures to predict the safety and modes of action of chemicals, cosmetics, air particles and pharmaceuticals. The major hurdles to the translation of these breakthrough achievements of cell culture technology into meaningful solutions for predictive high throughput substance testing remain miniaturization from the milliliter to the microliter scale and the supply of relevant amounts of standardized human tissue. This chapter provides insights into the latest developments in this area, illustrates an original multi-micro-organ bioreactor concept and identifies highways for closing the gap. PMID:22437811

Marx, Uwe

2012-01-01

145

Isolation, culture and characterization of human peritoneal mesothelial cells  

Microsoft Academic Search

Isolation, culture and characterization of human peritoneal mesothelial cells. This study establishes a reproducible technique for the culture of human peritoneal mesothelial cells. Direct explants, as well as enzymatically degraded specimens, of human omentum have been used as the source of cells. Cells were grown on collagen and gelatin coated matrices and were maintained in supplemented Ham's F-12 medium containing

Eleni Stylianou; Lucy A Jenner; Malcolm Davies; Gerald A Coles; John D Williams

1990-01-01

146

Cellular and molecular aspects of thiamin uptake by human liver cells: studies with cultured HepG2 cells  

Microsoft Academic Search

The liver is an important site for thiamin metabolism, utilization, and storage. Little is known about the mechanism of thiamin uptake by the human liver. In this study, we examined cellular and molecular aspects of the human liver thiamin uptake process using the human-derived liver HepG2 cells as a model system. Our studies showed that the initial rate of thiamin

Hamid M Said; Jack C Reidling; Alvaro Ortiz

2002-01-01

147

Microfabricated Platforms for Mechanically Dynamic Cell Culture  

PubMed Central

The ability to systematically probe in vitro cellular response to combinations of mechanobiological stimuli for tissue engineering, drug discovery or fundamental cell biology studies is limited by current bioreactor technologies, which cannot simultaneously apply a variety of mechanical stimuli to cultured cells. In order to address this issue, we have developed a series of microfabricated platforms designed to screen for the effects of mechanical stimuli in a high-throughput format. In this protocol, we demonstrate the fabrication of a microactuator array of vertically displaced posts on which the technology is based, and further demonstrate how this base technology can be modified to conduct high-throughput mechanically dynamic cell culture in both two-dimensional and three-dimensional culture paradigms.

Moraes, Christopher; Sun, Yu; Simmons, Craig A.

2010-01-01

148

QUANTITATIVE STUDIES OF THE GROWTH OF MOUSE EMBRYO CELLS IN CULTURE AND THEIR DEVELOPMENT INTO ESTABLISHED LINES  

Microsoft Academic Search

Disaggrcgatcd mouse embryo cells, grown in monolaycrs, undcrwcnt a progrcssivc dcclinc in growth ratc upon succcssivc transfer, the rapidity of the decline dcpcnding, among othcr things, on the inoculation density. Ncvcrthclcss, ncarly all culturcs dcvclopcd into cstablishcd lincs within 3 months of culture. Thc first sign of thc emcrgcncc of an established line was the ability of thc cells to

GEORGE J. TODARO; HOWARD GREEN

1963-01-01

149

Krabbe's globoid cell leucodystrophy. Studies on galactosylceramide beta-galactosidase and non-specific beta-galactosidase of leucocytes, cultured skin fibroblasts, and amniotic fluid cells  

Microsoft Academic Search

Galactosylceramide beta-galactosidase (cerebrosidase) and nonspecific beta-galactosidase activities were measured in both cultured skin fibroblasts and leucocytes from a family with Krabbe's globoid cell leucodystrophy (GLD). The activities of these enzymes were also determined in cultured skin fibroblasts of a patient with GM1 gangliosidosis and in cultured amniotic fluid cells. While cerebrosidase activity was deficient in GLD fibroblasts and leucocytes, its

G T Besley; A D Bain

1976-01-01

150

Interaction of atherogenic lipoproteins with cultured cells: a confocal laser scanning microscopy study  

NASA Astrophysics Data System (ADS)

Low density lipoprotein (LDL) and lipoprotein (a) [Lp(a)] were covalently labeled with the fluorescent dyes BODIPY succinimidyl ester (green) or Rhodamine iodoacetamide (red). The interaction of the fluorescent lipoproteins with HepG2 cells was visualized by means of a confocal laser scanning fluorescence microscope operating in the dual wavelength mode. If LDL or Lp(a) were incubated with the cells both lipoproteins bound to the cell surface at 4 degree(s)C or were internalized by the cells at 37 degree(s)C. In all cases larger amounts of LDL interacted with the cells compared with Lp(a). When mixtures of LDL and Lp(a), each labeled with a different dye, were incubated with cells again both lipoproteins bound to the cell surface (4 degree(s)C) or were internalized by the cells (37 degree(s)C). In addition, the major part of the lipoproteins colocalized either on the cell surface or inside the cells. thus, we conclude that interactions of Lp(a) with cells is mediated by LDL, probably via the LDL receptor, to a large extent.

Hofer, Gerald; Gorges, Roland; Paltauf, Fritz; Kostner, Gerhard M.; Hermetter, Albin

1994-08-01

151

Cellular and molecular aspects of thiamin uptake by human liver cells: studies with cultured HepG2 cells.  

PubMed

The liver is an important site for thiamin metabolism, utilization, and storage. Little is known about the mechanism of thiamin uptake by the human liver. In this study, we examined cellular and molecular aspects of the human liver thiamin uptake process using the human-derived liver HepG2 cells as a model system. Our studies showed that the initial rate of thiamin uptake to be: (1) Na(+)-independent and occurs with no detectable metabolic alterations in the transported substrate, (2) highly pH-dependent with diminished uptake upon decreasing incubation buffer pH from 8.0 to 5.0, (3) higher following cell acidification compared to unacidified control cells, (4) saturable as a function of concentration with an apparent K(m) of 7.7+/-1.6 microM, (5) inhibited by the thiamin structural analogues oxythiamin and amprolium but not by the unrelated organic cations tetraethylammonium (TEA) and N-methylnicotinamide (NMN), and (6) inhibited in a concentration-dependent manner by the membrane transport inhibitor amiloride. Both of the recently cloned human thiamin transporters, i.e., SLC19A2 and SLC19A3, were found to be expressed in liver HepG2 cells with the former being the predominant form. High promoter activity of the predominant form, i.e., SLC19A2, was detected in HepG2 cells, and the minimal region of the SLC19A2 promoter required for its basal activity in these cells was found to be encoded in a sequence between -356 and -36 and has multiple putative cis-regulatory elements. Mutation of a number of these putative cis-elements diminished promoter activity of the SLC19A2 minimal region. These results show the involvement of a specialized carrier-mediated mechanism for thiamin uptake by human liver HepG2 cells. In addition, SLC19A2 was found to be the predominant thiamin uptake carrier expressed in these cells and its promoter displays a high level of activity in them. PMID:12488043

Said, Hamid M; Reidling, Jack C; Ortiz, Alvaro

2002-12-23

152

Multilocus DNA fingerprint analysis of cellbanks: Stability studies and culture identification in human B-lymphoblastoid and mammalian cell lines  

Microsoft Academic Search

The technique of multilocus DNA fingerprinting has great potential for the authentication of animal cell cultures and in identification\\u000a of cross-contamination. The Alec Jeffreys probes 33.6 and 33.15 were used as multilocus probes to demonstrate the consistent\\u000a DNA fingerprint profiles in human peripheral blood and its derivative Epstein-Barr virus (EBV) transformed B-lymphoblastoid\\u000a cultures maintained by repeated subculture for six months.

G. N. Stacey; B. J. Bolton; D. Morgan; S. A. Clark; A. Doyle

1992-01-01

153

Cytopathogenicity of Naegleria fowleri for rat neuroblastoma cell cultures: scanning electron microscopy study.  

PubMed Central

Neuroblastoma cells were inoculated with Naegleria fowleri Lee and examined for cytopathology at various periods post-inoculation by scanning electron microscopy. By 18 h post-inoculation, approximately 50% of neuroblastoma cells were nonviable, as evidenced by trypan blue exclusion and light microscopic examination. This cytopathology resulted from piecemeal consumption of target cells mediated by a sucker apparatus extending from the surface of N. fowleri. Images

Marciano-Cabral, F; John, D T

1983-01-01

154

Wound Coverage by Cultured Skin Cells.  

National Technical Information Service (NTIS)

At the conclusion of a three year study on ways to improve wound healing by cultured epidermal grafts, we have found that: We were able to grow epidermal cells on collapsed collagen sponges. As a result, we can create a skin transplant with a quarter of t...

M. Eisinger

1988-01-01

155

Isolation and Culture of Larval Cells from C. elegans  

PubMed Central

Cell culture is an essential tool to study cell function. In C. elegans the ability to isolate and culture cells has been limited to embryonically derived cells. However, cells or blastomeres isolated from mixed stage embryos terminally differentiate within 24 hours of culture, thus precluding post-embryonic stage cell culture. We have developed an efficient and technically simple method for large-scale isolation and primary culture of larval-stage cells. We have optimized the treatment to maximize cell number and minimize cell death for each of the four larval stages. We obtained up to 7.8×104 cells per microliter of packed larvae, and up to 97% of adherent cells isolated by this method were viable for at least 16 hours. Cultured larval cells showed stage-specific increases in both cell size and multinuclearity and expressed lineage- and cell type-specific reporters. The majority (81%) of larval cells isolated by our method were muscle cells that exhibited stage-specific phenotypes. L1 muscle cells developed 1 to 2 wide cytoplasmic processes, while L4 muscle cells developed 4 to 14 processes of various thicknesses. L4 muscle cells developed bands of myosin heavy chain A thick filaments at the cell center and spontaneously contracted ex vivo. Neurons constituted less than 10% of the isolated cells and the majority of neurons developed one or more long, microtubule-rich protrusions that terminated in actin-rich growth cones. In addition to cells such as muscle and neuron that are high abundance in vivo, we were also able to isolate M-lineage cells that constitute less than 0.2% of cells in vivo. Our novel method of cell isolation extends C. elegans cell culture to larval developmental stages, and allows use of the wealth of cell culture tools, such as cell sorting, electrophysiology, co-culture, and high-resolution imaging of subcellular dynamics, in investigation of post-embryonic development and physiology.

Zhang, Sihui; Banerjee, Diya; Kuhn, Jeffrey R.

2011-01-01

156

5-Fluorouracil resistance in carrot cell cultures : Its use in studying the interaction of the pyrimidine and arginine pathways.  

PubMed

Physiological studies of 5-fluorouracil (5-FU)-resistant cell line of wild carrot (Daucus carota L.), F5, showed that this variant is also resistant to 5-fluorouridine, but is as sensitive to 6-azauracil as the 5-FU-sensitive parent line, WOO1C. High levels of exogenous uracil, uridine, and thymine are slightly toxic to F5, but not to WOO1C. 5-FU sensitivity in WOO1C cannot be reversed by bases and nucleosides; bases like uracil and thymine even increase 5-FU toxicity. No substantial differences were found in the uptake, incorporation and degradation of WOO1C and F5. Carrot cultures seem to take up 5-FU by rapid diffusion, the kinetics being characteristic of non-saturable uptake, with infinite Km and zero Vmax. The rapid uptake of 5-FU and extensive degradation of bases and nucleosides are probably responsible for the inability of uracil and uridine to reverse the growth inhibition caused by 5-FU in carrot cells while, as shown earlier, phaseolotoxin ((N-phosphosulfamyl)ornithinylalanylhomoarginine), an inhibitor of the arginine biosynthetic enzyme, ornithine transcarbamylase was capable of reducing 5-FU toxicity. F5 callus contained less histidine and arginine than WOO1C. 5-FU increased the endogenous levels of arginine, histidine and aspartate in both lines. The aspartate transcarbamylase of F5 appears to be normal; it is as sensitive to uridine-monophosphate inhibition as that of WOO1C. The 5-FU resistance of F5 was stable in undifferentiated cells, but only 8 out of 50 calli reinitiated from the regenerated plantlets remained resistant to 5-FU. F5 is an aneuploid culture. Five 5-FU-sensitive reinitiated calli that were examined were all diploid whereas of the eight 5-FU-resistant reinitiated calli two became diploid and six remained as aneuploid. PMID:24310143

Sung, Z R; Jacques, S

1980-04-01

157

Evolution of cell culture systems for HCV.  

PubMed

Many challenges exist for the study of HCV in the laboratory. Therapy using interferon (IFN) is expensive, not well tolerated and ineffective for many patients. HCV research has been hampered by the lack of a robust tissue culture system, but recent advances have made virus growth in culture possible. Cell culture systems using genetically engineered viruses have been reviewed extensively, but here we review recent advances made in the use of natural isolates and the molecular challenges that have been used to overcome the limitations in their growth. Six major genotypes have been identified for HCV that are further divided into numerous subtypes. Combination therapy utilizing IFN-? and ribavirin is the standard of care, but is successful in only one-half of patients. The reasons for IFN resistance may be viral- or host-related and may be due to multiple factors. Recently, telaprevir and boceprevir, together with IFN-? and ribavirin, have been added to the standard of care in patients infected with IFN-resistant genotypes. A major obstacle in the development of effective vaccines and improved therapeutics has been the lack of a reproducible and efficient tissue culture system for propagation of HCV. Many cell culture systems have used genetically-engineered viruses to gain growth in culture through the use of replicons, but recent advances using natural isolates may improve the outlook for progress in HCV research. PMID:23792335

Taylor, Deborah R

2013-01-01

158

Ligand Accumulation in Autocrine Cell Cultures  

Microsoft Academic Search

Cell-culture assays are routinely used to analyze autocrine signaling systems, but quantitative experiments are rarely possible. To enable the quantitative design and analysis of experiments with autocrine cells, we develop a biophysical theory of ligand accumulation in cell-culture assays. Our theory predicts the ligand concentration as a function of time and measurable parameters of autocrine cells and cell-culture experiments. The

Michael I. Monine; Alexander M. Berezhkovskii; Elizabeth J. Joslin; H. Steven Wiley; Douglas A. Lauffenburger; Stanislav Y. Shvartsman

2005-01-01

159

Spontaneous generation and survival of blood dendritic cells in mononuclear cell culture without exogenous cytokines  

Microsoft Academic Search

Studies on purified blood dendritic cells (DCs) are hampered by poor viability in tissue culture. We, therefore, attempted to study some of the interactions\\/relation- ships between DCs and other blood cells by culturing unseparated peripheral blood mononuclear cell (PBMC) preparations in vitro. Flow cytometric techniques were used to undertake a phenotypic and func- tional analysis of DCs within the cultured

Christopher S. K. Ho; David Munster; Christopher M. Pyke; Derek N. J. Hart; J. Alejandro Lopez

2010-01-01

160

Cell Cycle Progression of Human Cells Cultured in Rotating Bioreactor  

NASA Technical Reports Server (NTRS)

Space flight has been shown to alter the astronauts immune systems. Because immune performance is complex and reflects the influence of multiple organ systems within the host, scientists sought to understand the potential impact of microgravity alone on the cellular mechanisms critical to immunity. Lymphocytes and their differentiated immature form, lymphoblasts, play an important and integral role in the body's defense system. T cells, one of the three major types of lymphocytes, play a central role in cell-mediated immunity. They can be distinguished from other lymphocyte types, such as B cells and natural killer cells by the presence of a special receptor on their cell surface called T cell receptors. Reported studies have shown that spaceflight can affect the expression of cell surface markers. Cell surface markers play an important role in the ability of cells to interact and to pass signals between different cells of the same phenotype and cells of different phenotypes. Recent evidence suggests that cell-cycle regulators are essential for T-cell function. To trigger an effective immune response, lymphocytes must proliferate. The objective of this project is to investigate the changes in growth of human cells cultured in rotating bioreactors and to measure the growth rate and the cell cycle distribution for different human cell types. Human lymphocytes and lymphoblasts will be cultured in a bioreactor to simulate aspects of microgravity. The bioreactor is a cylindrical culture vessel that incorporates the aspects of clinostatic rotation of a solid fluid body around a horizontal axis at a constant speed, and compensates gravity by rotation and places cells within the fluid body into a sustained free-fall. Cell cycle progression and cell proliferation of the lymphocytes will be measured for a number of days. In addition, RNA from the cells will be isolated for expression of genes related in cell cycle regulations.

Parks, Kelsey

2009-01-01

161

Density gradient electrophoresis of cultured human embryonic kidney cells  

NASA Technical Reports Server (NTRS)

Ground based confirmation of the electrophoretic heterogeneity of human embryonic kidney cell cultures, the general characterization of their electrophoretic migration, and observations on the general properties of cultures derived from electrophoretic subpopulations were studied. Cell migration in a density gradient electrophoresis column and cell electrophoretic mobility was determined. The mobility and heterogeneity of cultured human embryonic kidney cells with those of fixed rat erythrocytes as model test particle was compared. Electrophoretically separated cell subpopulations with respect to size, viability, and culture characteristics were examined.

Plank, L. D.; Kunze, M. E.; Giranda, V.; Todd, P. W.

1985-01-01

162

A digitized fluorescence imaging study of intracellular Ca 2+ , pH, and mitochondrial function in primary cultures of rabbit corneal epithelial cells exposed to sodium dodecyl sulfate  

Microsoft Academic Search

Summary  Primary cultures of rabbit corneal epithelial cells have been developed as an in vitro system to predict irritancy potential\\u000a and delayed cytotoxicity of surfactants in our laboratory. The objective of this study was to evaluate the effects of the\\u000a surfactant sodium dodecyl sulfate (SDS), a common ingredient in consumer products, on intracellular Ca2+, pH, and mitochondrial function in this culture

Wei Yang; Daniel Acosta

1995-01-01

163

Culture and differentiation of embryonic stem cells  

Microsoft Academic Search

Summary Techniques are described for the culture of murine embryonic stem cells in the absence of heterologous feeder cells and for the induction of differentiation programs. The regulatory factor differentiation inhibiting activity\\/ leukaemia inhibitory factor (DIA\\/LIF) is produced at high concentration by transient expression in Cos cells and is used to suppress stem cell differentiation by addition to the culture

Austin G. Smith

1991-01-01

164

In vitro imaging of primary neural cell culture from Drosophila.  

PubMed

Cell culture systems are widely used for molecular, genetic and biochemical studies. Primary cell cultures of animal tissues offer the advantage that specific cell types can be studied in vitro outside of their normal environment. We provide a detailed protocol for generating primary neural cell cultures derived from larval brains of Drosophila melanogaster. The developing larval brain contains stem cells such as neural precursors and intermediate neural progenitors, as well as fully differentiated and functional neurons and glia cells. We describe how to analyze these cell types in vitro by immunofluorescent staining and scanning confocal microscopy. Cell type-specific fluorescent reporter lines and genetically encoded calcium sensors allow the monitoring of developmental, cellular processes and neuronal activity in living cells in vitro. The protocol provides a basis for functional studies of wild-type or genetically manipulated primary neural cells in culture, both in fixed and living samples. The entire procedure takes ?3 weeks. PMID:23598446

Egger, Boris; van Giesen, Lena; Moraru, Manuela; Sprecher, Simon G

2013-05-01

165

EFFECTS OF ARGININE DEPRIVATION, ULTRAVIOLET RADIATION, AND X RADIATION ON CULTURED KB CELLS. A CYTOCHEMICAL AND ULTRASTRUCTURAL STUDY  

Microsoft Academic Search

Cultured KB cells (derived from a human oral carcinoma) grown in monolayers were in- jured by one of three agcnts: starvation by arginine deprivation or trcatment with high doses of either ultraviolct radiation or x-radiation. The different agents produced changes in nucleolar structure and varying accumulations of triglyceridc and glycogcn. All three agents produced an increase in number and size

ALEX B. NOVIKOFF

1965-01-01

166

CHARACTERIZATION OF ALVEOLAR EPITHELIAL CELLS CULTURED IN SEMIPERMEABLE HOLLOW FIBERS  

PubMed Central

Cell culture methods commonly used to represent alveolar epithelial cells in vivo have lacked airflow, a 3-dimensional air-liquid interface, and dynamic stretching characteristics of native lung tissue—physiological parameters critical for normal phenotypic gene expression and cellular function. Here the authors report the development of a selectively semipermeable hollow fiber culture system that more accurately mimics the in vivo microenvironment experienced by mammalian distal airway cells than in conventional or standard air-liquid interface culture. Murine lung epithelial cells (MLE-15) were cultured within semipermeable polyurethane hollow fibers and introduced to controlled airflow through the microfiber interior. Under these conditions, MLE-15 cells formed confluent monolayers, demonstrated a cuboidal morphology, formed tight junctions, and produced and secreted surfactant proteins. Numerous lamellar bodies and microvilli were present in MLE-15 cells grown in hollow fiber culture. Conversely, these alveolar type II cell characteristics were reduced in MLE-15 cells cultured in conventional 2D static culture systems. These data support the hypothesis that MLE-15 cells grown within our microfiber culture system in the presence of airflow maintain the phenotypic characteristics of type II cells to a higher degree than those grown in standard in vitro cell culture models. Application of our novel model system may prove advantageous for future studies of specific gene and protein expression involving alveolar epithelial or bronchiolar epithelial cells.

Grek, Christina L.; Newton, Danforth A.; Qiu, Yonhzhi; Wen, Xuejun; Spyropoulos, Demetri D.; Baatz, John E.

2012-01-01

167

[Cell culture system for hepatitis E virus].  

PubMed

Early studies reported propagation of hepatitis E virus (HEV) in primary hepatocytes or several established cell lines, but replication was inefficient. Recently, using inocula comprised of fecal suspensions with high loads of HEV, originally obtained from Japanese patients who contracted domestic infection of genotype 3 HEV (the JE03-1760F strain, 2.0 x 10(7) copies/ml) or genotype 4 HEV (the HE-JF5/15F strain, 1.3 x 10(7) copies/ml), we developed an efficient cell culture system for HEV in PLC/PRF/5 and A549 cells, which yielded the highest HEV load of 10(8) copies/ml in the culture supernatant, and we successfully propagated six or more generations in serial passages of culture supernatant. In addition, we constructed a full-length infectious cDNA clone (pJE03-1760F/wt) of the JE03-1760F strain, which can replicate efficiently in PLC/PRF/5 and A549 cells. Using a derivative ORF3-deficient (delta ORF3) mutant, we demonstrated that the ORF3 protein of HEV is responsible for virion egress from infected cells and is present on the surface of released HEV particles, which is associated with lipids. Various HEV strains in blood circulation were also propagated efficiently in PLC/PRF/5 and A549 cells. Our in vitro cell culture system can be used for propagation of a wide variety of HEV strains in feces and sera from various infected patients, allowing extended studies on viral replication specific to different HEV strains. PMID:20848869

Okamoto, Hiroaki

2010-06-01

168

Cell culture metabolomics in the diagnosis of lung cancer-the influence of cell culture conditions.  

PubMed

Lung cancer is the leading cause of cancer deaths. Unfortunately, lung cancer is often diagnosed only when it becomes symptomatic or at an advanced stage when few treatment options are available. Hence, a diagnostic test suitable for screening widespread populations is required to enable earlier diagnosis. Analysis of exhaled breath provides a non-invasive method for early detection of lung cancer. Analysis of volatile organic compounds (VOCs) by various mass spectral techniques has identified potential biomarkers of disease. Nevertheless, the metabolic origins and the disease specificity of VOCs need further elucidation. Cell culture metabolomics can be used as a bottom-up approach to identify biomarkers of pathological conditions and can also be used to study the metabolic pathways that produce such compounds. This paper summarizes the current knowledge of lung cancer biomarkers in exhaled breath and emphasizes the critical role of cell culture conditions in determining the VOCs produced in vitro. Hypoxic culture conditions more closely mimic the conditions of cancer cell growth in vivo. We propose that since hypoxia influences cell metabolism and so potentially the VOCs that the cancer cells produce, the cell culture metabolomics projects should consider culturing cancer cells in hypoxic conditions. PMID:24861817

Kalluri, U; Naiker, M; Myers, M A

2014-06-01

169

On Studying Organizational Cultures.  

ERIC Educational Resources Information Center

Examines the values of the concepts of symbol, language, ideology, belief, ritual, and myth in understanding the creation of new cultures and in unraveling the related processes by which entrepreneurs give energy, purpose, and commitment to the organizations they are bringing into being. (Author/IRT)

Pettigrew, Andrew M.

1979-01-01

170

Culture surface influence on T-cell phenotype and function.  

PubMed

When dealing with T lymphocyte culture there is currently very less information available about the interaction between T-cells and the culture system. In this study we look at the influence of the culture chamber on T-cell proliferation in two main aspects of the culture system, namely: culture chamber material and geometry. The study was carried out using unique polymeric closed cell culture inserts, which were processed via injection moulding from polystyrene (PS), polycarbonate (PC), polyetherurethane (PEU), polystyrene-co-acrylonitrile (PSAN) and polyetherimide (PEI). Furthermore culture chamber geometry was studied using commercially available 24, 12 and 6-well plates prepared from tissue culture plastic (TCP). For T lymphocyte stimulation two methods were used involving either EBV peptide pools or MACS iBead particles depending on the experiment performed. Culture was done with 1645 RPMI medium supplemented with foetal calf serum, penicillin, streptomycin and rhIL-2. We found four materials out of five we tested (PS, PC, PSAN and PEI) exhibited similar fold expansions with minimal influence on proportions of CD4 and CD8, while PEU had a negative influence on T cell growth along with adversely affected CD4/CD8 proportions. Changes in the geometry of TCP had no effect on T cell growth or maturation rather the size of geometry seems to have more influence on proliferation. T-cells appear to prefer smaller geometries during initial stages of culture while towards the end of the culture size becomes less significant to cell proliferation. The parameters tested in this study have significant influences on T-cell growth and are necessary to consider when designing and constructing expansion systems for antigen specific T lymphocytes. This is important when culturing T-cells for immunotherapeutic applications where antigen specificity, T-cell maturation and function should remain unaffected during culture. PMID:24099989

Hashimdeen, Shaikh Shimaz; Römhild, Andy; Schmueck, Michael; Kratz, Karl; Lendlein, Andreas; Kurtz, Andreas; Reinke, Petra

2013-01-01

171

Gonococcal and meningococcal pathogenesis as defined by human cell, cell culture, and organ culture assays.  

PubMed Central

Human cells, cell cultures, and organ cultures have been extremely useful for studying the events that occur when gonococci and meningococci encounter human mucosal surfaces. The specificity and selectivity of these events for human cells are striking and correlate with the adaptation of these pathogens for survival on human mucous membranes. To colonize these sites, meningococci and gonococci have developed mechanisms to damage local host defenses such as the mucociliary blanket, to attach to epithelial cells, and to invade these cells. Attachment to epithelial cells mediated by pili, and to some types of cells mediated by PIIs, serves to anchor the organism close to sources of nutrition and allows multiplication. Intracellular invasion, possibly initiated by the major porin protein, may provide additional nutritional support and protection from host defenses. Mucosal invasion may also result in access of gonococci and meningococci to the bloodstream, leading to dissemination. Images

Stephens, D S

1989-01-01

172

Centrifugation of Cultured Osteoblasts And Macrophages as a Model To Study How Gravity Regulates The Function of Skeletal Cells  

NASA Technical Reports Server (NTRS)

Mechanical loading helps define the architecture of weight-bearing bone via the tightly regulated process of skeletal turnover. Turnover occurs by the concerted activity of osteoblasts, responsible for bone formation. and osteoclasts, responsible for bone resorption. Osteoclasts are specialized megakaryon macrophages, which differentiate from monocytes in response to resorption stimuli, such as reduced weight-bearing. Habitation in space dramatically alters musculoskeletal loading, which modulates both cell function and bone structure. Our long-term objective is to define the molecular and cellular mechanisms that mediate skeletal adaptations to altered gravity environments. Our experimental approach is to apply hypergravity loads by centrifugation to rodents and cultured cells. As a first step, we examined the influence of centrifugation on the structure of cancellous bone in rats to test the ability of hypergravity to change skeletal architecture. Since cancellous bone undergoes rapid turnover we expected the most dramatic structural changes to occur in the shape of trabeculae of weight-bearing, cancellous bone. To define the cellular responses to hypergravity loads, we exposed cultured osteoblasts and macrophages to centrifugation. The intraosseous and intramedullary pressures within long bones in vivo reportedly range from 12-40 mm Hg, which would correspond to 18-59 gravity (g) in our cultures. We assumed that hydrostatic pressure from the medium above the cell layer is at least one major component of the mechanical load generated by centrifuging cultured cells. and therefore we exposed the cells to 10-50g. In osteoblasts, we examined the structure of their actin and microtubule networks, production of prostaglandin E2 (PGE2), and cell survival. Analysis of the shape of the cytoskeletal networks provides evidence for the ability of centrifugation to affect cell structure, while the production of PGE2 serves as a convenient marker for mechanical stimulation. We examined cell survival, reasoning that osteoblasts might mold skeletal structure in a hypergravity environment in part by regulating apoptosis and thus the duration of osteoblast productivity. Finally, we tested the influence of centrifugation on microbial activation of a macrophage cell line (RAW264.7). In response to the appropriate hormonal stimulation, this cell line is reportedly capable of undergoing differentiation to express osteoclast markers. In addition, a component of the cell wall of gram-negative bacteria, lipopolysaccaride (LPS), stimulates the formation of osteoclasts in vivo. Thus we tested the influence on centrifugation on RAW264.7 cells stimulated with LPS to provide an index of the function of osteoclast precursors.

Globus, Ruth K.; Searby, Nancy D.; Almeida, Eduardo A. C.; Sutijono, Darrell; Yu, Joon-Ho; Malouvier, Alexander; Doty, Steven B.; Morey-Holton, Emily; Weinstein, Steven L.; Dalton, Bonnie P. (Technical Monitor)

2000-01-01

173

Three-dimensional perfused cell culture.  

PubMed

Compelling evidence suggests the limitation and shortcomings of the current and well established cell culture method using multi-well plates, flasks and Petri dishes. These are particularly important when cell functions are sensitive to the local microenvironment, cell-cell and cell-extracellular matrix interactions. There is a clear need for advanced cell culture systems which mimic in vivo and more physiological conditions. This review summarises and analyses recent progress in three dimensional (3D) cell culture with perfusion as the next generation cell culture tools, while excluding engineered tissue culture where three dimensional scaffold has to be used for structural support and perfusion for overcoming mass transfer control. Apart from research activities in academic community, product development in industry is also included in this review. PMID:24184152

Li, Zhaohui; Cui, Zhanfeng

2014-01-01

174

Krabbe's globoid cell leucodystrophy. Studies on galactosylceramide beta-galactosidase and non-specific beta-galactosidase of leucocytes, cultured skin fibroblasts, and amniotic fluid cells.  

PubMed Central

Galactosylceramide beta-galactosidase (cerebrosidase) and nonspecific beta-galactosidase activities were measured in both cultured skin fibroblasts and leucocytes from a family with Krabbe's globoid cell leucodystrophy (GLD). The activities of these enzymes were also determined in cultured skin fibroblasts of a patient with GM1 gangliosidosis and in cultured amniotic fluid cells. While cerebrosidase activity was deficient in GLD fibroblasts and leucocytes, its activity in GM1 gangliosidosis fibroblasts was increased. Two forms of each enzyme were found on isoelectric focusing, but in the GM1 gangliosidosis fibroblasts, cerebrosidase activity occurred as a single but intermediate peak. The use of cultured cells in assessing isoenzyme abnormalities associated with certain neurolipidoses is discussed.

Besley, G T; Bain, A D

1976-01-01

175

Replication of cultured lung epithelial cells  

Microsoft Academic Search

The authors have investigated the conditions necessary to support replication of lung type 2 epithelial cells in culture. Cells were isolated from mature fetal rabbit lungs (29d gestation) and cultured on feeder layers of mitotically inactivated 3T3 fibroblasts. The epithelial nature of the cells was demonstrated by indirect immunofluorescent staining for keratin and by polyacid dichrome stain. Ultrastructural examination during

D. Guzowski; R. Bienkowski

1986-01-01

176

Cell Culture as an Alternative in Education.  

ERIC Educational Resources Information Center

Programs that are intended to inform and provide "hands-on" experience for students and to facilitate the introduction of cell culture-based laboratory exercises into the high school and college laboratory are examined. The components of the CellServ Program and the Cell Culture Toxicology Training Programs are described. (KR)

Nardone, Roland M.

1990-01-01

177

Study on characteristics of in vitro culture and intracellular transduction of exogenous proteins in fibroblast cell line of Liaoning cashmere goat.  

PubMed

Establishment of fibroblast cell lines of endangered goat breeds and research on the gene or protein functions based on the cells made a significant contribution to the conservation and utilization of genetic resources. In this study, a fibroblast cell line of Liaoning cashmere goat, frozen in 174 cryovials with 5 × 10(6) cells each, was successfully established from 60 goats ear marginal tissues using explant culture and cryopreservation techniques. Biological analysis of in vitro cultured cell line showed that, the cells were morphologically consistent with fibroblasts; the average viability of the cells was 94.9 % before freezing and 90.1 % after thawing; the growth process of cells was consisted of a lag phase, a logarithmic phase and a plateau phase; cell population doubling time was 65.5 h; more than 90 % of cells were diploid prior to the 6th generation; Neither microbial contamination nor cross-contamination was detected. To determine cell permeability, intracellular path and stability of exogenous proteins during the transduction, a TAT protein transduction domain was fused to the C-terminus of enhanced green fluorescent protein, the established fibroblast cell line was treated with the purified exogenous proteins at various concentrations by adding them to the cell culture media for 1-24 h and assayed cell morphology and protein presence, it was found that the purified exogenous proteins readily entered cells at a concentration of 0.1 mg/ml within 1.5 h and some of them could translocate into nucleus, moreover, the exogenous proteins appeared to be stable inside cells for up to 24 h. PMID:23065271

Hu, P F; Guan, W J; Li, X C; Zhang, W X; Li, C L; Ma, Y H

2013-01-01

178

Nanotechnology in drug delivery: the need for more cell culture based studies in screening  

PubMed Central

Advances in biomedical science are leading to upsurge synthesis of nanodelivery systems for drug delivery. The systems were characterized by controlled, targeted and sustained drug delivery ability. Humans are the target of these systems, hence, animals whose systems resembles humans were used to predict outcome. Thus, increasing costs in money and time, plus ethical concerns over animal usage. However, with consideration and planning in experimental conditions, in vitro pharmacological studies of the nanodelivery can mimic the in vivo system. This can function as a simple method to investigate the effect of such materials without endangering animals especially at screening phase.

2014-01-01

179

TISSUE CULTURE STUDIES  

PubMed Central

A fraction of the ultrafilterable portion of chick embryo extract was isolated by alcohol extraction of a lyophilized powder of the ultrafiltrate followed by ion exchange removal of many of the inert components of the alcohol extract. This fraction contained 3 per cent of the ultrafilterable nitrogen but was capable of completely restoring the growth-promoting activity of dialyzed embryo extract, when tested with chick heart fibroblasts in roller tube cultures. The low nitrogen content, shape of the ultraviolet absorption spectrum, and presence of few free amino acids, suggest that non-dialyzable compounds serve as the chief source of nutrition for this system.

Rosenberg, Sheldon; Zitcer, Elsa; Kirk, Paul L.

1953-01-01

180

Genomics in mammalian cell culture bioprocessing  

PubMed Central

Explicitly identifying the genome of a host organism including sequencing, mapping, and annotating its genetic code has become a priority in the field of biotechnology with aims at improving the efficiency and understanding of cell culture bioprocessing. Recombinant protein therapeutics, primarily produced in mammalian cells, constitute a $108 billion global market. The most common mammalian cell line used in biologic production processes is the Chinese hamster ovary (CHO) cell line, and although great improvements have been made in titer production over the past 25 years, the underlying molecular and physiological factors are not well understood. Confident understanding of CHO bioprocessing elements (e.g. cell line selection, protein production, and reproducibility of process performance and product specifications) would significantly improve with a well understood genome. This review describes mammalian cell culture use in bioprocessing, the importance of obtaining CHO cell line genetic sequences, and the current status of sequencing efforts. Furthermore, transcriptomic techniques and gene expression tools are presented, and case studies exploring genomic techniques and applications aimed to improve mammalian bioprocess performance are reviewed. Finally, future implications of genomic advances are surmised.

Wuest, Diane M.; Harcum, Sarah W.; Lee, Kelvin H.

2013-01-01

181

Three-dimensional tissue culture based on magnetic cell levitation  

NASA Astrophysics Data System (ADS)

Cell culture is an essential tool in drug discovery, tissue engineering and stem cell research. Conventional tissue culture produces two-dimensional cell growth with gene expression, signalling and morphology that can be different from those found in vivo, and this compromises its clinical relevance. Here, we report a three-dimensional tissue culture based on magnetic levitation of cells in the presence of a hydrogel consisting of gold, magnetic iron oxide nanoparticles and filamentous bacteriophage. By spatially controlling the magnetic field, the geometry of the cell mass can be manipulated, and multicellular clustering of different cell types in co-culture can be achieved. Magnetically levitated human glioblastoma cells showed similar protein expression profiles to those observed in human tumour xenografts. Taken together, these results indicate that levitated three-dimensional culture with magnetized phage-based hydrogels more closely recapitulates in vivo protein expression and may be more feasible for long-term multicellular studies.

Souza, Glauco R.; Molina, Jennifer R.; Raphael, Robert M.; Ozawa, Michael G.; Stark, Daniel J.; Levin, Carly S.; Bronk, Lawrence F.; Ananta, Jeyarama S.; Mandelin, Jami; Georgescu, Maria-Magdalena; Bankson, James A.; Gelovani, Juri G.; Killian, T. C.; Arap, Wadih; Pasqualini, Renata

2010-04-01

182

Cell culture, oxidative stress, and antioxidants: Avoiding pitfalls.  

PubMed

Cell culture is widely used by biochemists and cell/molecular biologists, but the fluctuating (and often elevated) levels of O 2 to which cells in culture are exposed can affect many of their properties. So can the low level of antioxidants found in some cell culture media. Reagents, especially "antioxidants," added to cell culture media can react with the constituents of the media to produce H 2 O 2 and degradation products that can influence cell behavior. Several published papers describing the cellular effects of ascorbate, polyphenols, and carotenoids have, in fact, reported artifacts due to the actions of the degradation products of these "antioxidants." A greater awareness of the potential artifacts in cell culture studies is needed among the free radical/antioxidant community. PMID:24923566

Halliwell, Barry

2014-01-01

183

Three-dimensional tissue culture based on magnetic cell levitation.  

PubMed

Cell culture is an essential tool in drug discovery, tissue engineering and stem cell research. Conventional tissue culture produces two-dimensional cell growth with gene expression, signalling and morphology that can be different from those found in vivo, and this compromises its clinical relevance. Here, we report a three-dimensional tissue culture based on magnetic levitation of cells in the presence of a hydrogel consisting of gold, magnetic iron oxide nanoparticles and filamentous bacteriophage. By spatially controlling the magnetic field, the geometry of the cell mass can be manipulated, and multicellular clustering of different cell types in co-culture can be achieved. Magnetically levitated human glioblastoma cells showed similar protein expression profiles to those observed in human tumour xenografts. Taken together, these results indicate that levitated three-dimensional culture with magnetized phage-based hydrogels more closely recapitulates in vivo protein expression and may be more feasible for long-term multicellular studies. PMID:20228788

Souza, Glauco R; Molina, Jennifer R; Raphael, Robert M; Ozawa, Michael G; Stark, Daniel J; Levin, Carly S; Bronk, Lawrence F; Ananta, Jeyarama S; Mandelin, Jami; Georgescu, Maria-Magdalena; Bankson, James A; Gelovani, Juri G; Killian, T C; Arap, Wadih; Pasqualini, Renata

2010-04-01

184

Effects of Ethanol and Acetaldehyde on Tight Junction Integrity: In Vitro Study in a Three Dimensional Intestinal Epithelial Cell Culture Model  

Microsoft Academic Search

BackgroundIntestinal barrier dysfunction and translocation of endotoxins are involved in the pathogenesis of alcoholic liver disease. Exposure to ethanol and its metabolite, acetaldehyde at relatively high concentrations have been shown to disrupt intestinal epithelial tight junctions in the conventional two dimensional cell culture models. The present study investigated quantitatively and qualitatively the effects of ethanol at concentrations detected in the

Elhaseen Elamin; Daisy Jonkers; Kati Juuti-Uusitalo; Sven van IJzendoorn; Freddy Troost; Hans Duimel; Jos Broers; Fons Verheyen; Jan Dekker; Ad Masclee

2012-01-01

185

Study of some enzyme activities in cultured chick embryo brain nerve cells treated by chick embryo brain extracts  

Microsoft Academic Search

Brain extracts from 8-day-old chick embryos have been shown to influence morphological development of dissociated brain cells from 7-day-old chick embryos in culture. Stimulatory, effects on size of the neuronal somas and on growth of long processes were observed by adding the cytosol of the brain extract or the dialysate of the cytosol. These morphological changes parallel modifications of various

Y. Cam; M. Ledig; A. Ebel; M. Sensenbrenner; P. Mandel

1980-01-01

186

Experimental hypersensitivity pneumonitis: transfer with cultured cells.  

PubMed

The importance of antibody and sensitized cells in hypersensitivity pneumonitis (HP) is unknown. In an attempt to create a model suitable for investigation of the mechanisms of HP, we transferred cells and serum from sensitized (Micropolyspora faeni in Freund's adjuvant) strain 2 guinea pigs to naive animals. Cells (peritoneal exudate, lymph node, or spleen) were cultured for 72 hours with either concanavalin A (Con A, 1 microgram/ml) or a soluble extract of M. faeni (10 micrograms/ml). We then injected the cells intravenously (IV) into naive guinea pigs, skin tested with purified protein derivative (PPD), challenged the animals intratracheally (IT) with M. faeni 48 hours after the cell transfer, and killed them 4 days (IT) with M. faeni 48 hours after the cell transfer, and killed them 4 days after IT challenge. We also transferred noncultured cells and antibody-containing serum from sensitized animals. Randomly selected microscopic fields of the lung (150 per animal) were judged to be normal or abnormal. All guinea pigs were maintained in high-efficiency particulate accumulator-filtered air. Compared with control animals that received media IV, there was a substantial increase (P less than 0.01) in the extent of pulmonary abnormalities in the animals receiving lymph node cells or spleen cells cultured with M. faeni, and peritoneal exudate cells cultured with Con A. Findings in recipients of peritoneal exudate cells cultured with M. faeni, or lymph node cells or spleen cells cultured with Con A did not differ from those in the control group. In contrast to cultured cells, noncultured cells and antibody-containing serum did not transfer susceptibility. PPD skin reactivity was present only in recipients of noncultured cells and not in recipients of serum or cultured cells. We conclude that experimental HP can be transferred with cultured cells from sensitized animals and that HP appears to be a cell-mediated process. PMID:3585138

Schuyler, M; Subramanyan, S; Hassan, M O

1987-06-01

187

Algal culture studies for CELSS  

NASA Technical Reports Server (NTRS)

Microalgae are well-suited as a component of a Closed Environmental Life Support System (CELSS), since they can couple the closely related functions of food production and atmospheric regeneration. The objective was to provide a basis for predicting the response of CELSS algal cultures, and thus the food supply and air regeneration system, to changes in the culture parameters. Scenedesmus growth was measured as a function of light intensity, and the spectral dependence of light absorption by the algae as well as algal respiration in the light were determined as a function of cell concentration. These results were used to test and confirm a mathematical model that describes the productivity of an algal culture in terms of the competing processes of photosynthesis and respiration. The relationship of algal productivity to cell concentration was determined at different carbon dioxide concentrations, temperatures, and light intensities. The maximum productivity achieved by an air-grown culture was found to be within 10% of the computed maximum productivity, indicating that CO2 was very efficiently removed from the gas stream by the algal culture. Measurements of biomass productivity as a function of cell concentration at different light intensities indicated that both the productivity and efficiency of light utilization were greater at higher light intensities.

Radmer, R.; Behrens, P.; Arnett, K.; Gladue, R.; Cox, J.; Lieberman, D.

1987-01-01

188

Cysteine Metabolism in Cultured Tobacco Cells  

PubMed Central

Transported l-[35S]cysteine was rapidly metabolized by cultured tobacco cells when supplied to the cells at 0.02 millimolar or 0.5 millimolar. The internal cysteine pool was expandable to approximately 2400 nmoles per gram fresh weight. The 35S label derived from cysteine was found in several metabolites. The amount of label in glutathione and sulfate was directly proportional to the internal l-[35S]cysteine, while the levels of labeled methionine and protein were apparently independent of internal labeled cysteine. Cysteine was more rapidly metabolized when the external cysteine concentration was low (0.02 millimolar) with up to 90% of the 35S label present as compounds other than cysteine. The initial step in cysteine degradation yielded pyruvate, sulfide, and presumably NH4+. Stoichiometry studies using extracts prepared from acetone powders of tobacco cells indicated that pyruvate and sulfide were produced in a 1:1 ratio. The catabolic reaction was linear with respect to time and amount of protein and had a pH optimum of 8 in crude extracts. Preliminary kinetic data indicated the Km to be approximately 0.2 millimolar. The extractable degradative activity was enhanced 15- to 20-fold by preincubating the cells for 24 hours in 0.5 millimolar cysteine. The extractable specific enzyme activity roughly reflected the growth curve of the cells in culture. Maximal cysteine degradation was observed in extracts prepared from late log phase cultures that were preincubated in cysteine, while little activity was found in similar extracts from stationary phase cultures. These results are consistent with an inducible catabolic enzyme similar to the cysteine desulfhydrase from bacteria.

Harrington, H. Michael; Smith, Ivan K.

1980-01-01

189

In vitro cell culture methods for investigating Campylobacter invasion mechanisms  

Microsoft Academic Search

Studying the mechanisms of Campylobacter pathogenesis is complicated by the lack of simple animal models that mimic the disease seen in humans. In vitro cell culture methods provide a useful alternative to investigate the interactions between Campylobacter and the host epithelium that occur during infection. In the genomics era there is an increasing use of in vitro cell culture techniques

L. M. Friis; C. Pin; B. M. Pearson; J. M. Wells

2005-01-01

190

Ketamine is toxic to chondrocyte cell cultures.  

PubMed

Ketamine has been used in combination with a variety of other agents for intra-articular analgesia, with promising results. However, although it has been shown to be toxic to various types of cell, there is no available information on the effects of ketamine on chondrocytes. We conducted a prospective randomised controlled study to evaluate the effects of ketamine on cultured chondrocytes isolated from rat articular cartilage. The cultured cells were treated with 0.125 mM, 0.250 mM, 0.5 mM, 1 mM and 2 mM of ketamine respectively for 6 h, 24 hours and 48 hours, and compared with controls. Changes of apoptosis were evaluated using fluorescence microscopy with a 490 nm excitation wavelength. Apoptosis and eventual necrosis were seen at each concentration. The percentage viability of the cells was inversely proportional to both the duration and dose of treatment (p = 0.002 and p = 0.009). Doses of 0.5 mM, 1 mM and 2mM were absolutely toxic. We concluded that in the absence of solid data to support the efficacy of intra-articular ketamine for the control of pain, and the toxic effects of ketamine on cultured chondrocytes shown by this study, intra-articular ketamine, either alone or in combination with other agents, should not be used to control pain. Cite this article: Bone Joint J 2014; 96-B:989-94. PMID:24986956

Ozturk, A M; Ergun, M A; Demir, T; Gungor, I; Yilmaz, A; Kaya, K

2014-07-01

191

Patterning of polymeric cell culture substrates.  

PubMed

The purpose of this chapter is to provide a summary of polymer patterning technologies for biological applications and detailed instructions for resist-free deep ultraviolet (UV) patterning of poly(styrene). Photochemical modifications of this polymer yield unstable peroxides together with stable oxidized chemical groups. The altered physicochemical properties of the polymer surface influence protein adsorption and cell adhesion. HepG2 (human hepatoma cell line), fibroblasts (L929, murine fibroblast line), and other cell lines exhibit strong adhesion on areas of UV-irradiated polymer. Masked irradiations open a simple, fast (cell patterns are obtained within a few hours), and economical route to obtain chemically patterned cell culture substrates. The described protocol is advantageous compared to silane-based patterning techniques on glass or thiol-based patterning on gold because of the elimination of any chemical treatment and the small size of achieved structures. The protocol is compatible with common clean room technologies; however, even without access to a clean room, structured substrates can be produced. The described technique can be a useful tool for a variety of cell cultures used to study biological processes like intercellular communication and organogenesis and for applications like biosensing or tissue engineering. PMID:24439278

Welle, Alexander; Weigel, Simone; Bulut, Özgül Demir

2014-01-01

192

Culture of Cells from Amphibian Embryos.  

ERIC Educational Resources Information Center

Describes a method for in vitro culturing of cells from amphibian early embryos. Such cells can be used to demonstrate such properties of eukaryote cells as cell motility, adhesion, differentiation, and cell sorting into tissues. The technique may be extended to investigate other factors. (Author/JN)

Stanisstreet, Martin

1983-01-01

193

Human Cell Culture in a Space Bioreactor.  

National Technical Information Service (NTIS)

Microgravity offers new ways of handling fluids, gases, and growing mammalian cells in efficient suspension cultures. In 1976 bioreactor engineers designed a system using a cylindrical reactor vessel in which the cells and medium are slowly mixed. The rea...

D. R. Morrison

1988-01-01

194

Gametogony of Sarcocystis sp. in Cell Culture  

Microsoft Academic Search

Sexual stages and cystlike bodies of Sarcocystis sp., a protozoan parasite found in muscles of reptiles, birds, and mammals, including man, developed in cell culture. Motile organisms, obtained from leg muscles of wild grackles, were inoculated into cell line cultures of embryonic bovine kidney. Mature micro- and macrogametes and the cystlike forms were found 30 and 42 hours after inoculation,

Ronald Fayer

1972-01-01

195

AMMONIA REMOVAL FROM MAMMALIAN CELL CULTURE MEDIUM  

EPA Science Inventory

Metabolites such as ammonia and lactic formed during mammalian cell culture can frequently be toxic to the cells themselves beyond a threshold concentration of the metabolites. ell culture conducted in the presence of such accumulated metabolites is therefore limited in productiv...

196

Large-Scale Cell Culture in Biotechnology  

Microsoft Academic Search

The purpose of this article is to review the current state of large-scale cell culture in terms of its applications, problems, and potential. Because of the commercial and proprietary nature of most large-scale cell culture processes, this review does not contain many detailed scientific results although an attempt is made to address some key issues and findings. Much of this

W. R. Arathoon; J. R. Birch

1986-01-01

197

Degeneration of human respiratory cell ciliary beat in monolayer cell cultures  

Microsoft Academic Search

The degeneration of ciliary beat of human respiratory cells was studied in monolayer cell cultures by using a differential interference microscope equipped with a high speed video system. This method for studying ciliary beat in cell cultures on collagen-coated cover glasses is quite advantageous, because it allows for detailed study of all parts of ciliary function and not just ciliary

M. Rautiainen; S. Matsune; M. Yoshitsugu; M. Ohyama

1993-01-01

198

On the origin of lipofuscin; the iron content of residual bodies, and the relation of these organelles to the lysosomal vacuome. A study on cultured human glial cells  

SciTech Connect

Cultured human glial cells constitute a suitable model system for the study of lipofuscinogenesis in vitro. These cells, although not post-mitotic, can be kept for several months in stable monolayers due to their display of very pronounced density-dependent inhibition of cell growth. Residual bodies, or lipofuscin pigment granules, accumulate over time in this pseudo post-mitotic cell system. I. In early dense cultures, exposed to purified rat liver mitochondriae, it was possible to follow the uptake of mitochondriae and their degradation, which was found to be incomplete and result in the formation of numerous residual bodies containing lipofuscin-type material. It was concluded that incomplete degradation of mitochondriae may be an important origin of lipofuscin. II. Dense, older cultures exposed to electron dense marker particles (colloidal thorium dioxide) accumulated these markers within endosomes, and later in secondary lysosomes of various types, including residual bodies. It was concluded that residual bodies constitute an integral part of the lysosomal vacuome system. III. Phase III glial cells were cultured on formvar-coated gold EM-grids and studied by whole cell transmission electron microscopy using TEM and STEM techniques in combination with energy dispersive X-ray microanalysis. It was found that residual bodies contained iron. This fact was taken as a further indication that lipofuscin has its origin in autophagocytosed mitochondriae and ER-material rich in metallo-enzymes. Due to their high concentration of iron, residual bodies may constitute unstable structures within the cells. Since iron is a well known catalyst of various peroxidative processes, the surrounding lysosomal membrane might be damaged, e.g. by oxidative stress, with risk for leakage of degradative lysosomal enzymes into the cell sap.

Brunk, U.T. (Linkoeping Univ. (Sweden))

1989-01-01

199

On the origin of lipofuscin; the iron content of residual bodies, and the relation of these organelles to the lysosomal vacuome. A study on cultured human glial cells.  

PubMed

Cultured human glial cells constitute a suitable model system for the study of lipofuscinogenesis in vitro. These cells, although not post-mitotic, can be kept for several months in stable monolayers due to their display of very pronounced density-dependent inhibition of cell growth. Residual bodies, or lipofuscin pigment granules, accumulate over time in this "pseudo" post-mitotic cell system. I. In early dense cultures, exposed to purified rat liver mitochondriae, it was possible to follow the uptake of mitochondriae and their degradation, which was found to be incomplete and result in the formation of numerous residual bodies containing lipofuscin-type material. It was concluded that incomplete degradation of mitochondriae may be an important origin of lipofuscin. II. Dense, older cultures exposed to electron dense marker particles (colloidal thorium dioxide) accumulated these markers within endosomes, and later in secondary lysosomes of various types, including residual bodies. It was concluded that residual bodies constitute an integral part of the lysosomal vacuome system. III. Phase III glial cells were cultured on formvar-coated gold EM-grids and studied by whole cell transmission electron microscopy using TEM and STEM techniques in combination with energy dispersive X-ray microanalysis. It was found that residual bodies contained iron. This fact was taken as a further indication that lipofuscin has its origin in autophagocytosed mitochondriae and ER-material rich in metallo-enzymes. Due to their high concentration of iron, residual bodies may constitute unstable structures within the cells. Since iron is a well known catalyst of various peroxidative processes, the surrounding lysosomal membrane might be damaged, e.g. by oxidative stress, with risk for leakage of degradative lysosomal enzymes into the cell sap. PMID:2486159

Brunk, U T

1989-01-01

200

Use of an insect cell culture growth medium to isolate bacteria from horses with effusive, fibrinous pericarditis: a preliminary study.  

PubMed

Effusive, fibrinous pericarditis is an uncommon disease entity in horses. In 2001, pericarditis occurred in conjunction with an epizootic in central Kentucky that was associated with exposure to eastern tent caterpillars (ETCs). Bacterial isolation from equine pericardial fluid samples was attempted using an insect cell culture growth medium (ICCGM). Using previously cultured, stored frozen samples from four horses with fibrinous pericarditis, inoculation of 10% blood agar plates yielded no growth, whereas simultaneous inoculation of ICCGM resulted in the isolation of Proprionibacterium acnes, Staphylococcus equorum, a Streptococcus sp. and Pseudomonas rhodesiae from pericardial fluid samples. A similar or novel caterpillar-associated bacteria was not identified; however, use of an ICCGM might enhance isolation of bacteria from equine pericardial fluid. PMID:17204376

Jones, Samuel L; Valenzisi, Amy; Sontakke, Sushama; Sprayberry, Kimberly A; Maggi, Ricardo; Hegarty, Barbara; Breitschwerdt, Edward

2007-03-31

201

Comparison of cell cultures for rapid isolation of enteroviruses.  

PubMed Central

Cell culture isolation is still the most reliable method for the detection of enteroviruses from clinical specimens. Rapid diagnosis of enterovirus infection affects patient management. To increase yield and enhance the rapidity of enterovirus isolation in cell cultures, we used Buffalo green monkey kidney (BGM) cells and subpassages of primary human embryonic kidney (HEK) cells in addition to the human diploid fibroblast (MRC-5) cells and primary cynomolgus or rhesus monkey kidney (MK) cells routinely used for enterovirus culturing. Growth characteristics of enteroviruses from 421 specimens were studied. All specimens were cultured in MRC-5, MK, and BGM cells, and 204 of these specimens were also cultured in HEK cells. Forty-two percent of the enteroviruses became positive within 3 days, and 85% did so within 7 days. MRC-5 cells provided the highest yield of enteroviruses overall and were the best cell type for the recovery of poliovirus and echovirus. MK cells provided the second best yield but were more useful than MRC-5 cells for coxsackievirus. BGM cells supported the growth of additional isolates of coxsackievirus and enhanced the speed of isolation. HEK cells supported the growth of additional isolates of both coxsackievirus and echovirus, but subculturing was always required for definite enterovirus cytopathic effects. The recovery rate increased 11% when two additional cell lines were used. The use of two tubes of MK cells significantly increased the yield of all enterovirus types. We conclude that the use of multiple appropriate cell lines increases yield and enhances the rapidity of enterovirus isolation.

Chonmaitree, T; Ford, C; Sanders, C; Lucia, H L

1988-01-01

202

[Experimental studies on the bioeffects of pulsed ultrasound to the cultured mammalian cell in vitro (author's transl)].  

PubMed

Cultured cell originated from human amniotic epithelium was sonicated in 2 HMz pulsed ultrasound at various intensities for 30-60 min. Cell suspending medium on sonication was either phosphate buffered saline solution or Eagle's MEM containing calf serum of 20%. On the evaluation of cell growth suppression, relative growth ratios, the growth ratios in sonicated groups to control groups were calculated on 2, 4 and 7 days after sonication. Regression analysis between these relative growth ratios and spatial average-temporal peak intensities on 4 and 7 days after sonication showed linear correlation. Cell growth suppression threshold in the period was 246 or 240 mW/cm2 in spatial peak-temporal average value respectively. On the other hand, intensity measurements in experimental acoustic field by steel ball method showed that spatial peak values were about 2-5 times as large as spatial average values, and beam width in acoustic field (1.7 cm) was a little broader than the inner diameter of the cell suspending tube (1.2 cm). Cell growth suppression disappeared by elevation of viscosity in the cell suspending medium, and reappeared by the prolongation of sonication time or the increment of temporal peak value. PMID:7338663

Tsuzaki, T

1981-12-01

203

Ligand Accumulation in Autocrine Cell Cultures  

SciTech Connect

Cell-culture assays are routinely used to analyze autocrine signaling systems, but quantitative experiments are rarely possible. To enable the quantitative design and analysis of experiments with autocrine cells, we develop a biophysical theory of ligand accumulation in cell-culture assays. Our theory predicts the ligand concentration as a function of time and measurable parameters of autocrine cells and cell-culture experiments. The key step of our analysis is the derivation of the survival probability of a single ligand released from the surface of an autocrine cell. An expression for this probability is derived using the boundary homogenization approach and tested by stochastic simulations. We use this expression in the integral balance equations, from which we find the Laplace transform of the ligand concentration. We demonstrate how the theory works by analyzing the autocrine epidermal growth factor receptor system and discuss the extension of our methods to other experiments with cultured autocrine cells.

Monine, Michael I.; Berezhkovskii, Alexander M.; Joslin, Elizabeth J.; Wiley, H S.; Lauffenburger, Douglas A.; Shvartsman, Stanislav

2005-04-01

204

Cell viability studies and operation in cellular culture medium of n-type organic field-effect transistors  

NASA Astrophysics Data System (ADS)

The possibility of the fabrication of organic devices suitable to be applied in bio-sensing fields depends largely on the availability of organic compounds displaying robust electrical properties even in aqueous solutions and effective biocompatibility features. In this paper, we report about the good cellular biocompatibility and the electrical response stability in an ionic medium of n-type organic transistors based on the recently developed PDI-8CN2 oligomer. The biocompatibility has been tested by analyzing the adhesion and viability of two different cell lines, human epithelial HeLa cells and murine neuronal F11 cells, on PDI-8CN2 films grown by organic molecular beam deposition (OMBD) on SiO2 substrates. The effect of film thickness on cell attachment was also tested. Uncoated SiO2 substrates were used as control surfaces and sexithiophene (T6) as device testing control. Moreover, the possible toxicity of -CN groups of PDI-8CN2 was tested on HeLa cell cultures, using PDI-8 and T6 molecules as controls. Results showed that, although at high concentration these organic compounds are toxic in solution, if they are presented in form of film, cell lines can attach and grow on them. The electrical response stability of PDI-8CN2 transistors in a cellular culture medium characterized by high concentrations of ionic species has been also investigated. For this purpose, low-voltage operation devices with VGS ranging from -5 V to 5 V, able to strongly reduce the influence of Faradaic currents coming from the electrical operation in an highly ionic environment, have been fabricated on 35 nm thick SiO2 layers and electrically characterized. These results are useful to experimentally define the main critical issues to be further addressed for the fabrication of reliable bio-sensors based on organic transistors.

Barra, M.; Viggiano, D.; di Capua, R.; di Girolamo, F.; Santoro, F.; Taglialatela, M.; Cassinese, A.

2012-02-01

205

Ascorbic acid transport into cultured pituitary cells  

SciTech Connect

An amidating enzyme designated peptidyl-glycine ..cap alpha..-amidating monooxygenase (PAM) has been studied in a variety of tissues and is dependent on molecular oxygen and stimulated by copper and ascorbic acid. To continue investigating the relationship among cellular ascorbic acid concentrations, amidating ability, and PAM activity, the authors studied ascorbic acid transport in three cell preparations that contain PAM and produce amidated peptides: primary cultures of rat anterior and intermediate pituitary and mouse AtT-20 tumor cells. When incubated in 50 ..mu..M (/sup 14/C)ascorbic acid all three cell preparations concentrated ascorbic acid 20- to 40-fold, producing intracellular ascorbate concentrations of 1 to 2 mM, based on experimentally determined cell volumes. All three cell preparations displayed saturable ascorbic acid uptake with half-maximal initial rates occurring between 9 and 18 ..mu..M ascorbate. Replacing NaCl in the uptake buffer with choline chloride significantly diminished ascorbate uptake in all three preparations. Ascorbic acid efflux from these cells was slow, displaying half-lives of 7 hours. Unlike systems that transport dehydroascorbic acid, the transport system for ascorbic acid in these cells was not inhibited by glucose. Thus, ascorbate is transported into pituitary cells by a sodium-dependent, active transport system.

Cullen, E.I.; May, V.; Eipper, R.A.

1986-05-01

206

Cultural Studies, Multiculturalism, and Media Culture  

Microsoft Academic Search

Radio, television, film, and the other products of media culture provide materials out of which we forge our very identities; our sense of selfhood; our notion of what it means to be male or female; our sense of class, of ethnicity and race, of nationality, of sexuality; and of \\

Douglas Kellner

207

Biochemical assays of cultured cells  

NASA Technical Reports Server (NTRS)

Subpopulations of human embryonic kidney cells isolated from continuous flow electrophoresis experiments performed at McDonnell Douglas and on STS-8 have been analyzed. These analyses have included plasminogen activator assays involving indirect methodology on fibrin plated and direct methodology using chromogenic substrates. Immunological studies were performed and the conditioned media for erythropoietin activity and human granulocyte colony stimulating (HGCSF) activity was analyzed.

Barlow, G. H.

1985-01-01

208

Large-scale cell culture in biotechnology.  

PubMed

The purpose of this article is to review the current state of large-scale cell culture in terms of its applications, problems, and potential. Because of the commercial and proprietary nature of most large-scale cell culture processes, this review does not contain many detailed scientific results although an attempt is made to address some key issues and findings. Much of this summary deals with processes having an established, commercial track record but some attention is given to more recent innovations with interesting potential applications. Reference is made to plant cell culture but the main emphasis is on mammalian cells. PMID:2424083

Arathoon, W R; Birch, J R

1986-06-13

209

Cell volume and dry weight of cultured Tetrahymena  

Microsoft Academic Search

Summary Cultures of Tetrahymena pyriformis, T. hegewishi and T. malaccensis have been studied with regard to control of cell volume and cellular dry weight. Cell volume was measured on cells suspended in 0-9 % sodium chloride + 0-1 % sodium azide using a Multisizer cell counter (Coulter). Tetrahymena were grown at different temperatures and under various up- or downshift conditions.

PER HELLUNG-LARSEN; ANDERS POUL ANDERSEN

210

Effects of pulsing electromagnetic fields on cultured cartilage cells  

Microsoft Academic Search

In order to evaluate the effects of pulsing electromagnetic fields (PEMFs) on cell proliferation and glycosaminoglycan (GAG) synthesis and to study the action site of PEMF stimulation in the cells, we performed a series of experiments on rabbit costal growth cartilage cells and human articular cartilage cells in culture. A PEMF stimulator was made using a Helmholz coil. Repetitive pulse

A. Sakai; K. Suzuki; T. Nakamura; T. Norimura; T. Tsuchiya

1991-01-01

211

Epithelial cells from human fallopian tube in culture.  

PubMed

The epithelial cells lining the inner surface of the Fallopian tube influence the reproductive process by both their ciliary and secretory activities. The aim of the present work was to establish a method to culture these cells as a model for more specific studies of their properties. Minor slices of the mucosal ridges were cut and minced extensively using a fine scissor. The resulting pieces were washed once, resuspended in RPMI 1640 with 20% fetal calf serum and seeded in plastic dishes. After 2 days, the medium was replaced with RPMI 1640 containing human albumin, insulin and transferrin. Seven to 10 days later, the cell number had increased 5-8 times in 70% of the cultures. The identity of the cells was assessed after 1-3 weeks in culture. Of the cells, 98% stained positive for the antibody to epithelial cell-specific protein cytokeratin. Electron microscopic studies of the cultures showed epithelial characteristics including cilia, microvilli and intercellular junctions in the form of desmosomes. The cells could be kept in culture for 6-8 weeks. In conclusion, a method to culture epithelial cells from the human Fallopian tube is described. The cells have been identified and they can be kept in culture for 6-8 weeks in quantities sufficient for experimental use. PMID:2182659

Henriksen, T; Tanbo, T; Abyholm, T; Oppedal, B R; Claussen, O P; Hovig, T

1990-01-01

212

Sodium 22+ washout from cultured rat cells  

SciTech Connect

The washout of Na/sup +/ isotopes from tissues and cells is quite complex and not well defined. To further gain insight into this process, we have studied /sup 22/Na/sup +/ washout from cultured Wistar rat skin fibroblasts and vascular smooth muscle cells (VSMCs). In these preparations, /sup 22/Na/sup +/ washout is described by a general three-exponential function. The exponential factor of the fastest component (k1) and the initial exchange rate constant (kie) of cultured fibroblasts decrease in magnitude in response to incubation in K+-deficient medium or in the presence of ouabain and increase in magnitude when the cells are incubated in a Ca++-deficient medium. As the magnitude of the kie declines (in the presence of ouabain) to the level of the exponential factor of the middle component (k2), /sup 22/Na/sup +/ washout is adequately described by a two-exponential function. When the kie is further diminished (in the presence of both ouabain and phloretin) to the range of the exponential factor of the slowest component (k3), the washout of /sup 22/Na/sup +/ is apparently monoexponential. Calculations of the cellular Na/sup +/ concentrations, based on the /sup 22/Na/sup +/ activity in the cells at the initiation of the washout experiments, and the medium specific activity agree with atomic absorption spectrometry measurements of the cellular concentration of this ion. Thus, all three components of /sup 22/Na/sup +/ washout from cultured rat cells are of cellular origin. Using the exponential parameters, compartmental analyses of two models (in parallel and in series) with three cellular Na/sup +/ pools were performed. The results indicate that, independent of the model chosen, the relative size of the largest Na+ pool is 92-93% in fibroblasts and approximately 96% in VSMCs. This pool is most likely to represent the cytosol.

Kino, M.; Nakamura, A.; Hopp, L.; Kuriyama, S.; Aviv, A.

1986-10-01

213

Constructing a High Density Cell Culture System  

NASA Technical Reports Server (NTRS)

An annular culture vessel for growing mammalian cells is constructed in a one piece integral and annular configuration with an open end which is closed by an endcap. The culture vessel is rotatable about a horizontal axis by use of conventional roller systems commonly used in culture laboratories. The end wall of the endcap has tapered access ports to frictionally and sealingly receive the ends of hypodermic syringes. The syringes permit the introduction of fresh nutrient and withdrawal of spent nutrients. The walls are made of conventional polymeric cell culture material and are subjected to neutron bombardment to form minute gas permeable perforations in the walls.

Spaulding, Glenn F. (Inventor)

1996-01-01

214

Horizontally rotated cell culture system with a coaxial tubular oxygenator  

NASA Technical Reports Server (NTRS)

The present invention relates to a horizontally rotating bioreactor useful for carrying out cell and tissue culture. For processing of mammalian cells, the system is sterilized and fresh fluid medium, microcarrier beads, and cells are admitted to completely fill the cell culture vessel. An oxygen containing gas is admitted to the interior of the permeable membrane which prevents air bubbles from being introduced into the medium. The cylinder is rotated at a low speed within an incubator so that the circular motion of the fluid medium uniformly suspends the microbeads throughout the cylinder during the cell growth period. The unique design of this cell and tissue culture device was initially driven by two requirements imposed by its intended use for feasibility studies for three dimensional culture of living cells and tissues in space by JSC. They were compatible with microgravity and simulation of microgravity in one G. The vessels are designed to approximate the extremely quiescent low shear environment obtainable in space.

Wolf, David A. (inventor); Schwarz, Ray P. (inventor); Trinh, Tinh T. (inventor)

1991-01-01

215

Glycosylation of Fluorophenols by Plant Cell Cultures  

PubMed Central

Fluoroaromatic compounds are used as agrochemicals and released into environment as pollutants. Glycosylation of 2-, 3-, and 4-fluorophenols using plant cell cultures of Nicotiana tabacum was investigated to elucidate their potential to metabolize these compounds. Cultured N. tabacum cells converted 2-fluorophenol into its ?-glucoside (60%) and ?-gentiobioside (10%). 4-Fluorophenol was also glycosylated to its ?-glucoside (32%) and ?-gentiobioside (6%) by N. tabacum cells. On the other hand, N. tabacum glycosylated 3-fluorophenol to ?-glucoside (17%).

Shimoda, Kei; Kubota, Naoji; Kondo, Yoko; Sato, Daisuke; Hamada, Hiroki

2009-01-01

216

In vitro Cell Culture Model for Toxic Inhaled Chemical Testing.  

PubMed

Cell cultures are indispensable to develop and study efficacy of therapeutic agents, prior to their use in animal models. We have the unique ability to model well differentiated human airway epithelium and heart muscle cells. This could be an invaluable tool to study the deleterious effects of toxic inhaled chemicals, such as chlorine, that can normally interact with the cell surfaces, and form various byproducts upon reacting with water, and limiting their effects in submerged cultures. Our model using well differentiated human airway epithelial cell cultures at air-liqiuid interface circumvents this limitation as well as provides an opportunity to evaluate critical mechanisms of toxicity of potential poisonous inhaled chemicals. We describe enhanced loss of membrane integrity, caspase release and death upon toxic inhaled chemical such as chlorine exposure. In this article, we propose methods to model chlorine exposure in mammalian heart and airway epithelial cells in culture and simple tests to evaluate its effect on these cell types. PMID:24837339

Ahmad, Shama; Ahmad, Aftab; Neeves, Keith B; Hendry-Hofer, Tara; Loader, Joan E; White, Carl W; Veress, Livia

2014-01-01

217

Emulsions Containing Perfluorocarbon Support Cell Cultures  

NASA Technical Reports Server (NTRS)

Addition of emulsion containing perfluorocarbon liquid to aqueous cell-culture medium increases capacity of medium to support mammalian cells. FC-40 Fluorinert (or equivalent) - increases average density of medium so approximately equal to that of cells. Cells stay suspended in medium without mechanical stirring, which damages them. Increases density enough to prevent cells from setting, and increases viscosity of medium so oxygen bubbled through it and nutrients stirred in with less damage to delicate cells.

Ju, Lu-Kwang; Lee, Jaw Fang; Armiger, William B.

1990-01-01

218

High-precision isotope ratio mass spectrometry and stable isotope precursors for tracer studies in cell culture.  

PubMed

The use of stable isotope-labeled tracers is demonstrated in an in vitro system with analysis by high-precision isotope ratio mass spectrometry (IRMS), using n-3 long-chain polyunsaturated fatty acid (LCP) biosynthesis from [U-(13)C]18:3n-3 (18:3n-3*) in Y79 human retinoblastoma cells as a model system. The cells were cultured as a suspension in RPMI 1640 medium supplemented with 15% fetal calf serum at 37 degrees C with 5% CO(2) in air. They were harvested by sedimentation and cell lipids were extracted to determine the presence of 18:3n-3* metabolites using gas chromatography-combustion (GCC)-IRMS. As the dose of 18:3n-3* was systematically increased from treatment to treatment, the atom percent excess and the amounts of biosynthesized LCP* increased, while the percentage dose in each n-3 LCP* remained constant. Cultures incubated with 0.5 micromol (10 microM) of albumin-bound 18:3n-3, composed of 18:3n-3* diluted 1/60 or 1/100 with natural abundance 18:3n-3, yielded products with enrichments about 1.5 at.% excess (delta(13)C(PDB) < 1500 per thousand), which is optimal for high-precision measurements. Kinetics in Y79 cells incubated with 18:3n-3* showed that n-3 LCP* incorporation increased over time; 18:3n-3*, 20:5n-3*, 22:5n-3*, and 22:6n-3* were detected at all time points with the 1/60 dilution. These data document experimental parameters for optimal stable isotope use and IRMS detection for in vitro tracer methodology. PMID:11078586

Huang, M C; Muddana, S; Horowitz, E N; McCormick, C C; Infante, J P; Brenna, J T

2000-12-01

219

In Vitro Synthesis of Proteoglycans and Collagen in Primary Cultures of Mantle Cells from the Nacreous Mollusk, Haliotis tuberculata: A New Model for Study of Molluscan Extracellular Matrix.  

PubMed

In Mollusca, the mantle produces an organic matrix that mineralizes in time to make shell. Primary mantle cell cultures from the nacreous gastropod Haliotis tuberculata have been established as useful experimental model to investigate in vitro synthesis of both proteoglycans/glycosaminoglycans (PGs/GAGs) and collagen. First, we tested different enzymatic digestion procedures to find the method that gives the highest percentage of viable and adherent cultured cells. Enzymatic digestion with 0.1% pronase plus 0.1% collagenase was routinely used. Six days after the initiation of culture, about 80% of cells were viable, among which 20% were adherent as quantified by the MTT reduction assay. In addition, the protein synthesis estimated by [(3)H]leucine incorporation remained constant during this period. For the first time, we demonstrated a de novo synthesis of PGs/GAGs and collagen in primary cultures of mantle cells. After 48 hours of labeling, among the [(3)H]-d-glucosamine macromolecules synthesized, [(3)H]PGs/GAGs represented 43%, divided into 45% heparan sulfate, 37% chondroitin/dermatan sulfate, and 6% hyaluronic acid. Early elution on anion-exchange chromatography of these PGs/GAGs indicated that most of them appeared as undersulfated GAG molecules. De novo synthesis of collagen represents 4.52% +/- 0.84% (SD) with respect to the total protein synthesis. Such a model will facilitate studies on the synthesis of PGs/GAGs and collagen as components of the extracellular matrix and its regulation in Mollusca. Both PGs/GAGs and collagen participate in molecular events that regulate cell adhesion, migration, and proliferation. Further studies with this type of in vitro model should provide knowledge about novel aspects of molluscan cell signaling, in relation to extracellular matrix components. PMID:10960128

Poncet; Serpentini; Thiébot; Villers; Bocquet; Boucaud-Camou; Lebel

2000-07-01

220

Phenotypic and cytologic studies of lymphoid cells and monocytes in primary culture of porcine bone marrow during infection of African swine fever virus.  

PubMed

We have modeled in vitro infection of African swine fever virus (ASFV) in primary unstimulated cells of the porcine bone marrow and have studied the phenotypical changes in the population of porcine lymphoid cells by cytophotometry. Monocytes and large-sized lymphocytes completely vanished in 72 h of infection which is result of high sensitivity of those cells to ASFV. We describe DNA synthesis in monocytes at 24 h post infection. Cytophotometry of the uninfected cells revealed the few number of atypical lymphocytes and lymphoblasts after 72 h of cultivation; whereas in viral infected cultures, atypical cells appeared in large quantity (about 14%) with 24 h. Most of atypical lymphocytes and lymphoblasts had altered nucleus, and only a small number of atypical cells had additional nucleus. The cytophotometry of main and additional nuclei showed that DNA content didn't exceed diploid standard which indicates that the additional nuclei were consequence of fragmentation of nuclei in lymphocytes. PMID:21184199

Karalova, E M; Sargsyan, Kh V; Hampikian, G K; Voskanyan, H E; Abroyan, L O; Avetisyan, A S; Hakobyan, L A; Arzumanyan, H H; Zakaryan, H S; Karalyan, Zaven A

2011-03-01

221

Antibacterial effect of theaflavin, polyphenon 60 ( Camellia sinensis) and Euphorbia hirta on Shigella spp. — a cell culture study  

Microsoft Academic Search

Antibacterial effect of compounds extracted from Camellia sinensis L. and the methanol extract of Euphorbia hirta L. were studied against dysentery causing Shigella spp. using the Vero cell line. Cytotoxicity studies of the extracts were performed using the cell line and the non-cytotoxic concentration of the extract was tested for antibacterial activity against the cytopathic dose of the pathogen. These

K. Vijaya; S. Ananthan; R. Nalini

1995-01-01

222

In Vitro Studies on Rickettsia-Host Cell Interactions: Intracellular Growth Cycle of Virulent and Attenuated Rickettsia prowazeki in Chicken Embryo Cells in Slide Chamber Cultures  

PubMed Central

Upon entry into the cytoplasm of irradiated chicken embryo cells in slide chamber cultures infected over a 2-h period, yolk sac-grown virulent (Breinl strain) and attenuated (E strain) Rickettsia prowazeki underwent indistinguishable reproducible intracellular growth cycles. They promptly entered an exponential growth phase, without detectable lag and without microscopic evidence for any unusual early replicative phase. The generation time for both strains was 8.8 to 8.9 h at 34 C. During most of this period, the state of the organisms and growth were very similar from one cell to another. The exponential-growth phase continued for at least 36 to 48 h, when the rickettsiae became too numerous to count by microscopic examination. Between about 36 and 48 h, cells packed with rickettsiae began irregularly to break down and release organisms. These began to initiate new infection cycles in previously uninfected cells over many hours, as demonstrated by the rise in percentage of cells infected, yielding a highly disordered infected culture with different cells containing rickettsiae in diverse stages of growth. The organisms underwent regular minor changes in morphology, similar to those seen in bacterial cultures, in the first infection cycle. As the cells became packed with rickettsiae, the microorganisms regularly diminished in size to become minute coccobacillary to coccoid forms. However, the rickettsiae in the second and subsequent infection cycles in aging cultures often assumed filamentous or swollen bizarre forms. Only the first infection cycle conformed closely to the concept of a one-step growth cycle. A set of terms is proposed and defined for the infection cycle. Images

Wisseman, C. L.; Waddell, A. D.

1975-01-01

223

Stable Isotope Labeling with Amino Acids in Cell Culture (SILAC)-based Quantitative Proteomics Study of a Thyroid Hormone-regulated Secretome in Human Hepatoma Cells*  

PubMed Central

The thyroid hormone, 3, 3?,5-triiodo-l-thyronine (T3), regulates cell growth, development, differentiation, and metabolism via interactions with thyroid hormone receptors (TRs). However, the secreted proteins that are regulated by T3 are yet to be characterized. In this study, we used the quantitative proteomic approach of stable isotope labeling with amino acids in cell culture coupled with nano-liquid chromatography-tandem MS performed on a LTQ-Orbitrap instrument to identify and characterize the T3-regulated proteins secreted in human hepatocellular carcinoma cell lines overexpressing TR?1 (HepG2-TR?1). In total, 1742 and 1714 proteins were identified and quantified, respectively, in three independent experiments. Among these, 61 up-regulated twofold and 11 down-regulated twofold proteins were identified. Eight proteins displaying increased expression and one with decreased expression in conditioned media were validated using Western blotting. Real-time quantitative RT-PCR further disclosed induction of plasminogen activator inhibitor-1 (PAI-1), a T3 target, in a time-course and dose-dependent manner. Serial deletions of the PAI-1 promoter region and subsequent chromatin immunoprecipitation assays revealed that the thyroid hormone response element on the promoter is localized at positions –327/–312. PAI-1 overexpression enhanced tumor growth and migration in a manner similar to what was seen when T3 induced PAI-1 expression in J7-TR?1 cells, both in vitro and in vivo. An in vitro neutralizing assay further supported a crucial role of secreted PAI-1 in T3/TR-regulated cell migration. To our knowledge, these results demonstrate for the first time that proteins involved in the urokinase plasminogen activator system, including PAI-1, uPAR, and BSSP4, are augmented in the extra- and intracellular space of T3-treated HepG2-TR?1 cells. The T3-regulated secretome generated in the current study may provide an opportunity to establish the mechanisms underlying T3-associated tumor progression and prognosis.

Chen, Cheng-Yi; Chi, Lang-Ming; Chi, Hsiang-Cheng; Tsai, Ming-Ming; Tsai, Chung-Ying; Tseng, Yi-Hsin; Lin, Yang-Hsiang; Chen, Wei-Jan; Huang, Ya-Hui; Lin, Kwang-Huei

2012-01-01

224

Bioprocessing technology for plant cell suspension cultures  

Microsoft Academic Search

Considering various forms of in vitro plant tissue cultures, cell suspension culture is most amenable to large-scale production\\u000a of natural compounds, owing primarily to its superior culture homogeneity. This fact has already been demonstrated in several\\u000a largescale applications, including the commercial shikonin process. The scope of this work is to review the state of the art\\u000a in bioprocessing technologies pertinent

Wei wen Su

1995-01-01

225

Bupivacaine uncouples the mitochondrial oxidative phosphorylation, inhibits respiratory chain complexes I and III and enhances ROS production: Results of a study on cell cultures  

Microsoft Academic Search

This study aimed to validate, in situ, proposed mechanisms of bupivacaine citotoxicity pointing to impairment of the mitochondrial oxidative metabolism. High resolution oxymetry, carried out on a panel of cell cultures, revealed a dual dose- and time-dependent effect of bupivacaine consisting of uncoupling of the mt??H+-controlled respiratory rates in a cyclosporine A-insensitive manner and further inhibition of the respiratory rates.

Olga Cela; Claudia Piccoli; Rosella Scrima; Giovanni Quarato; Alessandra Marolla; Gilda Cinnella; Michele Dambrosio; Nazzareno Capitanio

2010-01-01

226

Hollow fiber culture accelerates differentiation of Caco-2 cells.  

PubMed

Caco-2 cells usually require 21 days of culture for developing sufficient differentiation in traditional two-dimensional Transwell culture, deviating far away from the quick differentiation of enterocytes in vivo. The recently proposed three-dimensional cultures of Caco-2 cells, though imitating the villi/crypt-like microstructure of intestinal epithelium, showed no effect on accelerating the differentiation of Caco-2 cells. In this study, a novel culture of Caco-2 cells on hollow fiber bioreactor was applied to morphologically mimic the human small intestine lumen for accelerating the expression of intestine functions. The porous hollow fibers of polyethersulfone (PES), a suitable membrane material for Caco-2 cell culture, successfully promoted cells to form confluent monolayer on the inner surface. The differentiated functions of Caco-2 cells, represented by alkaline phosphatase, ?-glutamyltransferase, and P-glycoprotein activity, were greatly higher in a 10-day hollow fiber culture than in a 21-day Transwell culture. Moreover, the Caco-2 cells on PES hollow fibers expressed higher F-actin and zonula occludens-1 protein than those on Transwell culture, indicative of an increased mechanical stress in Caco-2 cells on PES hollow fibers. The accelerated differentiation of Caco-2 cells on PES hollow fibers was unassociated with membrane chemical composition and surface roughness, but could be stimulated by hollow fiber configuration, since PES flat membranes with either rough or smooth surface failed to enhance the differentiation of Caco-2. Therefore, the accelerated expression of Caco-2 cell function on hollow fiber culture might show great values in simulation of the tissue microenvironment in vivo and guide the construction of intestinal tissue engineering apparatus. PMID:23689647

Deng, Xudong; Zhang, Guoliang; Shen, Chong; Yin, Jian; Meng, Qin

2013-08-01

227

Methods for Maintaining Insect Cell Cultures  

PubMed Central

Insect cell cultures are now commonly used in insect physiology, developmental biology, pathology, and molecular biology. As the field has advanced from methods development to a standard procedure, so has the diversity of scientists using the technique. This paper describes methods that are effective for maintaining various insect cell lines. The procedures are differentiated between loosely or non-attached cell strains, attached cell strains, and strongly adherent cell strains.

Lynn, Dwight E.

2002-01-01

228

Peroxisome dynamics in cultured mammalian cells.  

PubMed

Despite the identification and characterization of various proteins that are essential for peroxisome biogenesis, the origin and the turnover of peroxisomes are still unresolved critical issues. In this study, we used the HaloTag technology as a new approach to examine peroxisome dynamics in cultured mammalian cells. This technology is based on the formation of a covalent bond between the HaloTag protein--a mutated bacterial dehalogenase which is fused to the protein of interest--and a synthetic haloalkane ligand that contains a fluorophore or affinity tag. By using cell-permeable ligands of distinct fluorescence, it is possible to image distinct pools of newly synthesized proteins, generated from a single genetic HaloTag-containing construct, at different wavelengths. Here, we show that peroxisomes display an age-related heterogeneity with respect to their capacity to incorporate newly synthesized proteins. We also demonstrate that these organelles do not exchange their protein content. In addition, we present evidence that the matrix protein content of pre-existing peroxisomes is not evenly distributed over new organelles. Finally, we show that peroxisomes in cultured mammalian cells, under basal growth conditions, have a half-life of approximately 2 days and are mainly degraded by an autophagy-related mechanism. The implications of these findings are discussed. PMID:19719477

Huybrechts, Sofie J; Van Veldhoven, Paul P; Brees, Chantal; Mannaerts, Guy P; Los, Georgyi V; Fransen, Marc

2009-11-01

229

Feeding frequency affects cultured rat pituitary cells in low gravity.  

PubMed

In this report, we describe the results of a rat pituitary cell culture experiment done on STS-65 in which the effect of cell feeding on the release of the six anterior pituitary hormones was studied. We found complex microgravity-related interactions between the frequency of cell feeding and the quantity and quality (i.e. biological activity) of some of the six hormones released in flight. Analyses of growth hormone (GH) released from cells into culture media on different mission days using gel filtration and ion exchange chromatography yielded qualitatively similar results between ground and flight samples. Lack of cell feeding resulted in extensive cell clumping in flight (but not ground) cultures. Vigorous fibroblast growth occurred in both ground and flight cultures fed 4 times. These results are interpreted within the context of autocrine and/or paracrine feedback interactions. Finally, the payload specialist successfully prepared a fresh trypsin solution in microgravity, detached the cells from their surface and reinserted them back into the culture chamber. These cells reattached and continued to release hormone in microgravity. In summary, this experiment shows that pituitary cells are microgravity sensitive and that coupled operations routinely associated with laboratory cell culture can also be accomplished in low gravity. PMID:8987570

Hymer, W C; Grindeland, R E; Salada, T; Cenci, R; Krishnan, K; Mukai, C; Nagaoka, S

1996-06-27

230

Studies on the synthesis of sterol carrier protein-2 in rat adrenocortical cells in monolayer culture. Regulation by ACTH and dibutyryl cyclic 3',5'-AMP  

SciTech Connect

The effects of ACTH or dibutyryl cyclic AMP (Bt2cAMP) on the synthesis of sterol carrier protein-2 (SCP2) have been studied in rat adrenocortical cells in monolayer culture. Radiolabeling of total cellular proteins with (/sup 35/S)methionine and immunoprecipitation with antibodies directed against rat liver SCP2, followed by polyacrylamide gel electrophoresis and fluorography, showed a 3-4-fold increase in the rate of synthesis of SCP2 in cells treated for 48 h with ACTH (1 microM) or Bt2cAMP (0.1 mM). The induction of SCP2 synthesis depended upon the concentrations of ACTH or Bt2cAMP with an ED50 of 8 and 100 nM, respectively, and increased linearly with time between 12 and 48 h of treatment. Immunoprecipitation of SCP2 synthesized in a rabbit reticulocyte in vitro translation system programmed with RNA isolated from cells treated with ACTH or Bt2cAMP revealed increased synthesis of SCP2 compared to RNA from control cells. The immunoprecipitable rat adrenal SCP2, synthesized in a cell-free translation system, showed mobility corresponding to Mr of 14,400 upon sodium dodecyl sulfate-polyacrylamide gel electrophoresis and was clearly larger than immunodetectable SCP2 synthesized in cultured adrenal cells (Mr = 11,300). The electrophoretic mobilities of rat liver SCP2 synthesized in cultured cells and in a cell-free translation system were the same as the respective forms from rat adrenal.

Trzeciak, W.H.; Simpson, E.R.; Scallen, T.J.; Vahouny, G.V.; Waterman, M.R.

1987-03-15

231

Differential effects of selective frankincense (Ru Xiang) essential oil versus non-selective sandalwood (Tan Xiang) essential oil on cultured bladder cancer cells: a microarray and bioinformatics study  

PubMed Central

Background Frankincense (Boswellia carterii, known as Ru Xiang in Chinese) and sandalwood (Santalum album, known as Tan Xiang in Chinese) are cancer preventive and therapeutic agents in Chinese medicine. Their biologically active ingredients are usually extracted from frankincense by hydrodistillation and sandalwood by distillation. This study aims to investigate the anti-proliferative and pro-apoptotic activities of frankincense and sandalwood essential oils in cultured human bladder cancer cells. Methods The effects of frankincense (1,400–600 dilutions) (v/v) and sandalwood (16,000–7,000 dilutions) (v/v) essential oils on cell viability were studied in established human bladder cancer J82 cells and immortalized normal human bladder urothelial UROtsa cells using a colorimetric XTT cell viability assay. Genes that responded to essential oil treatments in human bladder cancer J82 cells were identified using the Illumina Expression BeadChip platform and analyzed for enriched functions and pathways. The chemical compositions of the essential oils were determined by gas chromatography–mass spectrometry. Results Human bladder cancer J82 cells were more sensitive to the pro-apoptotic effects of frankincense essential oil than the immortalized normal bladder UROtsa cells. In contrast, sandalwood essential oil exhibited a similar potency in suppressing the viability of both J82 and UROtsa cells. Although frankincense and sandalwood essential oils activated common pathways such as inflammatory interleukins (IL-6 signaling), each essential oil had a unique molecular action on the bladder cancer cells. Heat shock proteins and histone core proteins were activated by frankincense essential oil, whereas negative regulation of protein kinase activity and G protein-coupled receptors were activated by sandalwood essential oil treatment. Conclusion The effects of frankincense and sandalwood essential oils on J82 cells and UROtsa cells involved different mechanisms leading to cancer cell death. While frankincense essential oil elicited selective cancer cell death via NRF-2-mediated oxidative stress, sandalwood essential oil induced non-selective cell death via DNA damage and cell cycle arrest.

2014-01-01

232

Novel Insights into the Distribution and Functional Aspects of the Calcium Binding Protein Secretagogin from Studies on Rat Brain and Primary Neuronal Cell Culture  

PubMed Central

Secretagogin is a calcium binding protein (CBP) highly expressed in neuroendocrine cells. It has been shown to be involved in insulin secretion from pancreatic beta cells and is a strong candidate as a biomarker for endocrine tumors, stroke, and eventually psychiatric conditions. Secretagogin has been hypothesized to exert a neuroprotective role in neurodegenerative diseases like Alzheimer’s disease. The expression pattern of Secretagogin is not conserved from rodents to humans. We used brain tissue and primary neuronal cell cultures from rat to further characterize this CBP in rodents and to perform a few functional assays in vitro. Immunohistochemistry on rat brain slices revealed a high density of Secretagogin-positive cells in distinct brain regions. Secretagogin was found in the cytosol or associated with subcellular compartments. We tested primary neuronal cultures for their suitability as model systems to further investigate functional properties of Secretagogin. These cultures can easily be manipulated by treatment with drugs or by transfection with test constructs interfering with signaling cascades that might be linked to the cellular function of Secretagogin. We show that, like in pancreatic beta cells and insulinoma cell lines, also in neurons the expression level of Secretagogin is dependent on extracellular insulin and glucose. Further, we show also for rat brain neuronal tissue that Secretagogin interacts with the microtubule-associated protein Tau and that this interaction is dependent on Ca2+. Future studies should aim to study in further detail the molecular properties and function of Secretagogin in individual neuronal cell types, in particular the subcellular localization and trafficking of this protein and a possible active secretion by neurons.

Maj, Magdalena; Milenkovic, Ivan; Bauer, Jan; Berggard, Tord; Veit, Martina; Ilhan-Mutlu, Aysegul; Wagner, Ludwig; Tretter, Verena

2012-01-01

233

Deltamethrin induces apoptotic cell death in cultured cerebral cortical neurons  

Microsoft Academic Search

In this study we investigated the induction of apoptotic cell death and its potential mechanisms in cultured cortical neurons in response to deltamethrin exposure. The cultured cortical neurons were treated at 7 days with deltamethrin at concentrations of 10, 100, and 1000 nM, respectively. MTT assay showed that higher concentrations of deltamethrin (100 and 1000 nM) decreased neuronal viability in

Aiguo Wu; Long Li; Yugu Liu

2003-01-01

234

Oscillatory behavior of cells in tissue culture.  

NASA Astrophysics Data System (ADS)

Fibroblasts and epithelial cells organize themselves in distinct patterns in tissue culture which indicates that neighboring cells communicate. A striking example of such communication is the oscillatory behavior of Madin-Darby canine kidney (MDCK) cells reported here. These oscillations were discovered using a biosensor referred to as ECIS (Electric Cell-substrate Impedance Sensing). In this measurement cells are seeded out on a small electrode deposited at the bottom of a tissue culture well and immersed in ordinary culture medium. By measuring the changes in the impedance of the electrode as a function of time, many important properties of the cells on the electrode can be inferred, such as motion, morphology changes and membrane capacitance. The impedance oscillations of MDCK cells were observed with highly confluent cell layers, where the approximately 100 cells on the electrode acted in unison. The communication between cells can be demonstrated directly by a variation of the ECIS concept, where cells are cultured on two closely spaced electrodes. The impedance fluctuations are measured independently on each electrode and compared by using a cross-correlation function.

Giaever, Ivar; Linton, Michael F. A.; Keese, Charles R.

1998-03-01

235

Neurotransmitter release in aggregate cultures of chick embryo retina cells.  

PubMed

The study of neurotransmitter release using aggregate cell cultures has been limited by the fact that cell aggregates are obtained only when cells are maintained in suspension with rotatory agitation. In this report we describe a simple and easy method that uses aggregate cell cultures to study the release of neurotransmitters. The results demonstrate that this relatively simple technique can be of great value to address the problem of neurotransmitter release and study the mechanisms of action of natural and synthetic compounds on the differentiation of functional synapses in the CNS. PMID:9394496

do Nascimento, J L; Hokoç, J N; de Mello, M C; de Mello, F G

1996-12-01

236

Modeling of cell cultures in perfusion bioreactors.  

PubMed

Cultivating cells and tissues in bioreactors is a critical step in forming artificial tissues or organs prior to transplantation. Among various bioreactors, the perfusion bioreactor is known for its enhanced convection through the cell-scaffold constructs. Knowledge of mass transfer is essential for controlling the cell culture process; however, obtaining this information remains a challenging task. In this research, a novel mathematical model is developed to represent the nutrient transport and cell growth in a 3-D scaffold cultivated in a perfusion bioreactor. Numerical methods are employed to solve the equations involved, with a focus on identifying the effect of factors such as porosity, culturing time, and flow rate, which are controllable in the scaffold fabrication and culturing process, on cell cultures. To validate the new model, the results from the model simulations were compared to the experimental results extracted from the literature. With the validated model, further simulations were carried out to investigate the glucose and oxygen distribution and the cell growth within the cell-scaffold construct in a perfusion bioreactor, thus providing insight into the cell culture process. PMID:22772976

Yan, X; Bergstrom, D J; Chen, X B

2012-09-01

237

Comparison of human nasal epithelial cells grown as explant outgrowth cultures or dissociated tissue cultures in vitro.  

PubMed

The purpose of this study was to compare cell growth characteristics, ciliated cell differentiation, and function of human nasal epithelial cells established as explant outgrowth cultures or dissociated tissue cultures. Human nasal mucosa of the uncinate process was obtained by endoscopy and epithelial cell cultures were established by explant outgrowth or dissociated tissue culture methods. Epithelial cell growth characteristics were observed by inverted phase contrast microscopy. Ciliated cell differentiation was detected by ?-tubulin IVand ZO-1 immunocytochemistry. Basal and ATP-stimulated ciliary beat frequency (CBF) was measured using a highspeed digital microscopic imaging system. Both the explant and dissociated tissue cultures established as monolayers with tight junctions and differentiated cell composition, with both types of cultures comprising ciliated and non-ciliated epithelial cells. Fibroblasts were also frequently found in explant cultures but rarely seen in dissociated tissue cultures. In both culture systems, the highest ciliated cell density appeared at 7th-10th culture day and declined with time, with the lifespan of ciliated cells ranging from 14 to 21 days. Overall, 10% of the cells in explant cultures and 20% of the cells in the dissociated tissue cultures were ciliated. These two cultures demonstrated similar ciliary beat frequency values at baseline (7.78 ± 1.99 Hz and 7.91 ± 2.52 Hz, respectively) and reacted equivalently following stimulation with 100 ?M ATP. The results of this study indicate that both the explant outgrowth and dissociated tissue culture techniques are suitable for growing well-differentiated nasal ciliated and non-ciliated cells, which have growth characteristics and ciliary activity similar to those of nasal epithelial cells in vivo. PMID:24062261

Jiao, Jian; Meng, Na; Wang, Hong; Zhang, Luo

2013-12-01

238

Growth of melanocytes in human epidermal cell cultures  

SciTech Connect

Epidermal cell cultures were grown in keratinocyte-conditioned medium for use as burn wound grafts; the melanocyte composition of the grafts was studied under a variety of conditions. Melanocytes were identified by immunohistochemistry based on a monoclonal antibody (MEL-5) that has previously been shown to react specifically with melanocytes. During the first 7 days of growth in primary culture, the total number of melanocytes in the epidermal cultures decreased to 10% of the number present in normal skin. Beginning on day 2 of culture, bipolar melanocytes were present at a mean cell density of 116 +/- 2/mm2; the keratinocyte to melanocyte ratio was preserved during further primary culture and through three subpassages. Moreover, exposure of cultures to mild UVB irradiation stimulated the melanocytes to proliferate, suggesting that the melanocytes growing in culture maintained their responsiveness to external stimuli. When the sheets of cultured cells were enzymatically detached from the plastic culture flasks before grafting, melanocytes remained in the basal layer of cells as part of the graft applied to the patient.

Staiano-Coico, L.; Hefton, J.M.; Amadeo, C.; Pagan-Charry, I.; Madden, M.R.; Cardon-Cardo, C. (Cornell Medical College, New York, NY (USA))

1990-08-01

239

The Promise of Cultural Studies of Education.  

ERIC Educational Resources Information Center

Cultural studies practice within education can potentially positively transform education. Those within the field must target broader audiences and translate their messages to those in most need. This paper describes cultural studies in education; develops five key themes of cultural studies, critically reviewing four cultural studies of education…

Hytten, Kathy

1999-01-01

240

Feeding Frequency Affects Cultured Rat Pituitary Cells in Low Gravity  

NASA Technical Reports Server (NTRS)

In this report, we describe the results of a rat pituitary cell culture experiment done on STS-65 in which the effect of cell feeding on the release of the six anterior pituitary hormones was studied. We found complex microgravity related interactions between the frequency of cell feeding and the quantity and quality (i.e. biological activity) of some of the six hormones released in flight. Analyses of growth hormone (GH) released from cells into culture media on different mission days using gel filtration and ion exchange chromatography yielded qualitatively similar results between ground and flight samples. Lack of cell feeding resulted in extensive cell clumping in flight (but not ground) cultures. Vigorous fibroblast growth occurred in both ground and flight cultures fed 4 times. These results are interpreted within the context of autocrine and or paracrine feedback interactions. Finally the payload specialist successfully prepared a fresh trypsin solution in microgravity, detached the cells from their surface and reinserted them back into the culture chamber. These cells reattached and continued to release hormone in microgravity. In summary, this experiment shows that pituitary cells are microgravity sensitive and that coupled operations routinely associated with laboratory cel1 culture can also be accomplished in low gravity.

Hymer, W. C.; Grindeland, R. E.; Salada, T.; Cenci, R.; Krishnan, K.; Mukai, C.; Nagaoka, S.

1996-01-01

241

Ex vivo expansion of hematopoietic cells from CD34 + cord blood cells in various culture conditions  

Microsoft Academic Search

This study compared the cell expansion and colony-forming ability of human cord blood stem cells cultured ex vivo with 2 types of cytokine combinations, and 2 types of media characterized by the presence or absence of fetal bovine serum\\u000a (FBS) in 2 or 3 dimensional (2D or 3D) culture environments. Purified CD34+ cells derived from different donors were cultured in

Yong-Woon Choi; Hyun Hee Park; Duk Jae Oh

2010-01-01

242

Establishment and characterisation of a rapidly dividing diploid cell suspension culture of Arabidopsis thaliana suitable for cell cycle synchronisation  

Microsoft Academic Search

Polyploid plants often have altered gene expression, biochemistry, and metabolism compared to their diploid predecessors. Therefore cultured diploid cells have distinct benefits over cultured polyploid cells for the study of gene regulation and metabolism of the parent plant. Here we report methods for establishing and maintaining a rapidly dividing diploid Arabidopsis thaliana cell suspension culture, and subsequent cell cycle synchronisation.

Ranjith Pathirana; Jocelyn R. Eason

2006-01-01

243

Effect of lipoproteins on cultured human mesangial cells  

Microsoft Academic Search

It was recently reported that low-density lipoprotein (LDL) promotes mesangial cell proliferation, and oxidized LDL is cytotoxic for mesangial cells. However, there have been few studies about the effects of other lipoproteins on mesangial cells. Accordingly, we investigated the effect of various lipoproteins on cultured human mesangial cells using 3H-thymidine (3H-TdR) incorporation and cell counting assays. We also investigated the

Yoji Nishida; Noriaki Yorioka; Hiroaki Oda; Michio Yamakido

1997-01-01

244

Characterizing the mechanics of cultured cell monolayers  

PubMed Central

One-cell-thick monolayers are the simplest tissues in multicellular organisms, yet they fulfill critical roles in development and normal physiology. In early development, embryonic morphogenesis results largely from monolayer rearrangement and deformation due to internally generated forces. Later, monolayers act as physical barriers separating the internal environment from the exterior and must withstand externally applied forces. Though resisting and generating mechanical forces is an essential part of monolayer function, simple experimental methods to characterize monolayer mechanical properties are lacking. Here, we describe a system for tensile testing of freely suspended cultured monolayers that enables the examination of their mechanical behavior at multi-, uni-, and subcellular scales. Using this system, we provide measurements of monolayer elasticity and show that this is two orders of magnitude larger than the elasticity of their isolated cellular components. Monolayers could withstand more than a doubling in length before failing through rupture of intercellular junctions. Measurement of stress at fracture enabled a first estimation of the average force needed to separate cells within truly mature monolayers, approximately ninefold larger than measured in pairs of isolated cells. As in single cells, monolayer mechanical properties were strongly dependent on the integrity of the actin cytoskeleton, myosin, and intercellular adhesions interfacing adjacent cells. High magnification imaging revealed that keratin filaments became progressively stretched during extension, suggesting they participate in monolayer mechanics. This multiscale study of monolayer response to deformation enabled by our device provides the first quantitative investigation of the link between monolayer biology and mechanics.

Peter, Loic; Bellis, Julien; Baum, Buzz; Kabla, Alexandre J.; Charras, Guillaume T.

2012-01-01

245

Characterization of Human Fungiform Papillae Cells in Culture  

PubMed Central

The ability to maintain human fungiform papillae cells in culture for multiple cell cycles would be of considerable utility for characterizing the molecular, regenerative, and functional properties of these unique sensory cells. Here we describe a method for enzymatically isolating human cells from fungiform papillae obtained by biopsy and maintaining them in culture for more than 7 passages (7 months) without loss of viability and while retaining many of the functional properties of acutely isolated taste cells. Cells in these cultures exhibited increases in intracellular calcium when stimulated with perceptually appropriate concentrations of several taste stimuli, indicating that at least some of the native signaling pathways were present. This system can provide a useful model for molecular studies of the proliferation, differentiation, and physiological function of human fungiform papillae cells.

Brand, Joseph G.; Spielman, Andrew I.; Lischka, Fritz W.; Teeter, John H.; Breslin, Paul A.S.; Rawson, Nancy E.

2011-01-01

246

Isolation and Culture of Epithelial Stem Cells  

PubMed Central

In the skin, epithelial stem cells in the hair follicle contribute not only to the generation of a new hair follicle with each hair cycle, but also to the repair of the epidermis during wound healing. When these stem cells are isolated and expanded in culture, they can give rise to hair follicles, sebaceous glands, and epidermis when combined with dermis and grafted back onto Nude mice. In this chapter, we provide a method for isolating hair follicle epithelial stem cells from the skin of adult mice using immunofluorescent labeling to allow for the specific purification of epithelial stem cells by fluorescence-activated cell sorting (FACS). Notably, this method relies exclusively on cell surface markers, making it suitable for use with any strain of mouse and at various stages of the hair cycle. We also provide a detailed protocol for culturing epithelial stem cells isolated by FACS, allowing for analysis using a wide variety of culture assays. Additionally, we provide notes on using cultured cells for specific applications, such as viral manipulation and grafting. These techniques should be useful for directly evaluating stem cell function in normal mice and in mice with skin defects.

Nowak, Jonathan A.; Fuchs, Elaine

2009-01-01

247

Self-assembling Fmoc dipeptide hydrogel for in situ 3D cell culturing  

Microsoft Academic Search

BACKGROUND: Conventional cell culture studies have been performed on 2D surfaces, resulting in flat, extended cell growth. More relevant studies are desired to better mimic 3D in vivo tissue growth. Such realistic environments should be the aim of any cell growth study, requiring new methods for culturing cells in vitro. Cell biology is also tending toward miniaturization for increased efficiency

Thomas Liebmann; Susanna Rydholm; Victor Akpe; Hjalmar Brismar

2007-01-01

248

Genome selection within cell cultures of potato and tobacco  

Microsoft Academic Search

The ploidy level of callus cultures, suspensions and cell cultures derived from single cells and protoplasts of Solanum tuberosum\\u000a L. and Nicotania tabascum L. was analysed with the aim of studying selection processes. Genome selection was tested using\\u000a chromosome number. Subculture of callus lines mostly resulted in an increase of cytogenetic destabilization, whereas subculture\\u000a of suspensions led to an increase

Günter Wersuhn; Ursula Dathe

1998-01-01

249

Hypergravity signal transduction and gene expression in cultured mammalian cells  

NASA Technical Reports Server (NTRS)

A number of studies have been conducted during space flight and with clinostats and centrifuges, suggesting that gravity effects the proliferation and differentiation of mammalian cells in vitro. However, little is known about the mechanisms by which mammalian cells respond to changes in gravitational stress. This paper summarizes studies designed to clarify the effects of hypergravity on the cultured human HeLa cells and to investigate the mechanism of hypergravity signal transduction in these cells.

Kumei, Y.; Whitson, P. A.

1994-01-01

250

Cellular Heredity in Haploid Cultures of Somatic Cells. Comprehensive Report, April 1975--June 1977.  

National Technical Information Service (NTIS)

This report reviews genetic studies carried out since 1975 on a haploid cultured cell line from frog embryos (ICR 2A). Although a single chromosome set would be expected to facilitate recovery of recessive mutants, experiments suggested that cell culture ...

J. J. Freed

1977-01-01

251

Establishment, Culture, and Characterization of Guinea Pig Fetal Fibroblast Cell  

PubMed Central

Establishment of Guinea pig fetal fibroblast cells and their biological evaluation before and after cryopreservation were the main purposes of this study. After determination of the proper age of pregnancy by ultrasonography, 30 days old fetuses of Guinea pigs were recovered. Their skins were cut into small pieces (1?mm2) and were cultured. When reaching 80–90% confluence, the cells were passaged. Cells of the second and eighth passages were cultured in 24-well plates (4 × 104 cells/well) for 6 days and three wells per day were counted. The average cell counts at each time point were then plotted against time and the population doubling time (PDT) was determined. Then, vials of cells (2 × 106 cells/mL) were cryopreserved for 1 month and after thawing, the cell viability was evaluated. The PDT of the second passage was about 23?h and for the eighth passage was about 30?h. The viability of the cultures was 95% in the second passage and 74.5% in the eighth passage. It was shown that the Guinea pig fetal fibroblast cell culture can be established using the adherent culture method while, after freezing, the viability indices of these cells were favorable.

Mahboobi, Reza; Dianatpour, Mehdi; Zare, Shahrokh; Hosseini, Seyed Ebrahim

2014-01-01

252

Interaction of nanobacteria with cultured mammalian cells  

Microsoft Academic Search

Nanobacteria were recently isolated from human blood and commercial fetal bovine serum (FBS) and were located in the ?-2 subgroup of proteobacteria based upon their 16S rRNA gene sequence. They can be cultured even in the absence of mammalian cells, and have extraordinary properties, like very slow growth rate and an impermeable cell wall, making their detection difficult by standard

Neva Çiftçioglu; E. Olavi Kajander

1998-01-01

253

Effect of Magnetic Field on Adhesion of Muscle Cells to Culture Plate  

Microsoft Academic Search

The effect of a magnetic field on adhesion of cultured muscle cells to the culture plate has been studied in vitro. An experimental system was manufactured to apply a magnetic field to muscle cell culture. The system consists of a couple of solenoid coils, a culture dish of 52 mm internal diameter, and an inverted phase-contrast microscope. The solenoid coil

Junichi YORIKI; Shigehiro HASHIMOTO; Keiji TACHIBANA; Masahide OKADA; Shuichi MOCHIZUKI; Toshia FUJISATO; Hajime OTANI

254

Transferring isolated mitochondria into tissue culture cells.  

PubMed

We have developed a new method for introducing large numbers of isolated mitochondria into tissue culture cells. Direct microinjection of mitochondria into typical mammalian cells has been found to be impractical due to the large size of mitochondria relative to microinjection needles. To circumvent this problem, we inject isolated mitochondria through appropriately sized microinjection needles into rodent oocytes or single-cell embryos, which are much larger than tissue culture cells, and then withdraw a 'mitocytoplast' cell fragment containing the injected mitochondria using a modified holding needle. These mitocytoplasts are then fused to recipient cells through viral-mediated membrane fusion and the injected mitochondria are transferred into the cytoplasm of the tissue culture cell. Since mouse oocytes contain large numbers of mouse mitochondria that repopulate recipient mouse cells along with the injected mitochondria, we used either gerbil single-cell embryos or rat oocytes to package injected mouse mitochondria. We found that the gerbil mitochondrial DNA (mtDNA) is not maintained in recipient rho0 mouse cells and that rat mtDNA initially replicated but was soon completely replaced by the injected mouse mtDNA, and so with both procedures mouse cells homoplasmic for the mouse mtDNA in the injected mitochondria were obtained. PMID:22753025

Yang, Yi-Wei; Koob, Michael D

2012-10-01

255

Microfabricated polymeric vessel mimetics for 3-D cancer cell culture.  

PubMed

Modeling tumor growth in vitro is essential for cost-effective testing of hypotheses in preclinical cancer research. 3-D cell culture offers an improvement over monolayer culture for studying cellular processes in cancer biology because of the preservation of cell-cell and cell-ECM interactions. Oxygen transport poses a major barrier to mimicking in vivo environments and is not replicated in conventional cell culture systems. We hypothesized that we can better mimic the tumor microenvironment using a bioreactor system for controlling gas exchange in cancer cell cultures with silicone hydrogel synthetic vessels. Soft-lithography techniques were used to fabricate oxygen-permeable silicone hydrogel membranes containing arrays of micropillars. These membranes were inserted into a bioreactor and surrounded by basement membrane extract (BME) within which fluorescent ovarian cancer (OVCAR8) cells were cultured. Cell clusters oxygenated by synthetic vessels showed a ?100?m drop-off to anoxia, consistent with in vivo studies of tumor nodules fed by the microvasculature. Oxygen transport in the bioreactor system was characterized by experimental testing with a dissolved oxygen probe and finite element modeling of convective flow. Our study demonstrates differing growth patterns associated with controlling gas distributions to better mimic in vivo conditions. PMID:23911071

Jaeger, Ashley A; Das, Chandan K; Morgan, Nicole Y; Pursley, Randall H; McQueen, Philip G; Hall, Matthew D; Pohida, Thomas J; Gottesman, Michael M

2013-11-01

256

Isolation and Culture of Human Fungiform Taste Papillae Cells  

PubMed Central

Taste cells are highly specialized, with unique histological, molecular and physiological characteristics that permit detection of a wide range of simple stimuli and complex chemical molecules contained in foods. In human, individual fungiform papillae contain from zero to as many as 20 taste buds. There is no established protocol for culturing human taste cells, although the ability to maintain taste papillae cells in culture for multiple cell cycles would be of considerable utility for characterizing the molecular, regenerative, and functional properties of these unique sensory cells. Earlier studies of taste cells have been done using freshly isolated cells in primary culture, explant cultures from rodents, or semi-intact taste buds in tissue slices1,2,3,4. Although each of these preparations has advantages, the development of long-term cultures would have provided significant benefits, particularly for studies of taste cell proliferation and differentiation. Several groups, including ours, have been interested in the development and establishment of taste cell culture models. Most attempts to culture taste cells have reported limited viability, with cells typically not lasting beyond 3-5 d5,6,7,8. We recently reported on a successful method for the extended culture of rodent taste cells9. We here report for the first time the establishment of an in vitro culture system for isolated human fungiform taste papillae cells. Cells from human fungiform papillae obtained by biopsy were successfully maintained in culture for more than eight passages (12 months) without loss of viability. Cells displayed many molecular and physiological features characteristic of mature taste cells. Gustducin and phospholipase C ?2, (PLC-?2) mRNA were detected in many cells by reverse transcriptase-polymerase chain reaction and confirmed by sequencing. Immunocytochemistry analysis demonstrated the presence of gustducin and PLC-?2 expression in cultured taste cells. Cultured human fungiform cells also exhibited increases in intracellular calcium in response to appropriate concentrations of several taste stimuli indicating that taste receptors and at least some of the signalling pathways were present. These results sufficient indicate that taste cells from adult humans can be generated and maintained for at least eight passages. Many of the cells retain physiological and biochemical characteristics of acutely isolated cells from the adult taste epithelium to support their use as a model taste system. This system will enable further studies of the processes involved in proliferation, differentiation and function of mammalian taste receptor cells in an in vitro preparation. Human fungiform taste papillae used for establishing human fungiform cell culture were donated for research following proper informed consent under research protocols that were reviewed and approved by the IRB committee. The protocol (#0934) was approved by Schulman Associates Institutional Review Board Inc., Cincinnati, OH. Written protocol below is based on published parameters reported by Ozdener et al. 201110.

Ozdener, Hakan; Spielman, Andrew I.; Rawson, Nancy E.

2012-01-01

257

Classical human epidermal keratinocyte cell culture.  

PubMed

It has been more than 30 years since the serial cultivation of human keratinocytes in monolayer culture was first described by Rheinwald and Green. Initially, isolation of primary keratinocytes from disaggregated human skin tissue and subsequent propagation was promoted through use of replication-inactivated murine fibroblast feeder layers. Since then numerous advances have been made to the cultivation of human keratinocytes in both two-dimensional monolayer and three-dimensional organotypic culture. Monolayer culture facilitates keratinocyte proliferation, whereas organotypic culturing techniques promote keratinocyte differentiation using conditions permissive for stratification. The protocols presented here describe traditional culturing methods, providing guidance for isolation and serial cultivation of primary human keratinocytes and dermal fibroblasts, as well as the use of these cells types for generation of stratified skin tissue. PMID:23097107

Rasmussen, Cathy; Thomas-Virnig, Christina; Allen-Hoffmann, B Lynn

2013-01-01

258

Teaching Culture. The Long Revolution in Cultural Studies.  

ERIC Educational Resources Information Center

This book contains 12 papers that trace the connections and tensions between the original aims and forms of cultural studies in Great Britain and Northern Ireland and the current settings, goals, and methodologies of cultural studies. The following papers are included: "Introduction" (Nannette Aldred and Martin Ryle); "Marginal Occupations: Adult…

Aldred, Nannette, Ed.; Ryle, Martin, Ed.

259

A comparative study of different in vitro lung cell culture systems to assess the most beneficial tool for screening the potential adverse effects of carbon nanotubes.  

PubMed

To determine the potential inhalatory risk posed by carbon nanotubes (CNTs), a tier-based approach beginning with an in vitro assessment must be adopted. The purpose of this study therefore was to compare 4 commonly used in vitro systems of the human lung (human blood monocyte-derived macrophages [MDM] and monocyte-derived dendritic cells [MDDC], 16HBE14o- epithelial cells, and a sophisticated triple cell co-culture model [TCC-C]) via assessment of the biological impact of different CNTs (single-walled CNTs [SWCNTs] and multiwalled CNTs [MWCNTs]) over 24h. No significant cytotoxicity was observed with any of the cell types tested, although a significant (p < .05), dose-dependent increase in tumor necrosis factor (TNF)-? following SWCNT and MWCNT exposure at concentrations up to 0.02mg/ml to MDM, MDDC, and the TCC-C was found. The concentration of TNF-? released by the MDM and MDDC was significantly higher (p < .05) than the TCC-C. Significant increases (p < .05) in interleukin (IL)-8 were also found for both 16HBE14o- epithelial cells and the TCC-C after SWCNTs and MWCNTs exposure up to 0.02mg/ml. The TCC-C, however, elicited a significantly (p < .05) higher IL-8 release than the epithelial cells. The oxidative potential of both SWCNTs and MWCNTs (0.005-0.02mg/ml) measured by reduced glutathione (GSH) content showed a significant difference (p < .05) between each monoculture and the TCC-C. It was concluded that because only the co-culture system could assess each endpoint adequately, that, in comparison with monoculture systems, multicellular systems that take into consideration important cell type-to-cell type interactions could be used as predictive in vitro screening tools for determining the potential deleterious effects associated with CNTs. PMID:24284789

Clift, Martin J D; Endes, Carola; Vanhecke, Dimitri; Wick, Peter; Gehr, Peter; Schins, Roel P F; Petri-Fink, Alke; Rothen-Rutishauser, Barbara

2014-01-01

260

Shock wave application to cell cultures.  

PubMed

Shock waves nowadays are well known for their regenerative effects. Basic research findings showed that shock waves do cause a biological stimulus to target cells or tissue without any subsequent damage. Therefore, in vitro experiments are of increasing interest. Various methods of applying shock waves onto cell cultures have been described. In general, all existing models focus on how to best apply shock waves onto cells. However, this question remains: What happens to the waves after passing the cell culture? The difference of the acoustic impedance of the cell culture medium and the ambient air is that high, that more than 99% of shock waves get reflected! We therefore developed a model that mainly consists of a Plexiglas built container that allows the waves to propagate in water after passing the cell culture. This avoids cavitation effects as well as reflection of the waves that would otherwise disturb upcoming ones. With this model we are able to mimic in vivo conditions and thereby gain more and more knowledge about how the physical stimulus of shock waves gets translated into a biological cell signal ("mechanotransduction"). PMID:24747842

Holfeld, Johannes; Tepeköylü, Can; Kozaryn, Radoslaw; Mathes, Wolfgang; Grimm, Michael; Paulus, Patrick

2014-01-01

261

Culture, Immortalization, and Characterization of Human Meibomian Gland Epithelial Cells  

PubMed Central

Purpose. Meibomian gland epithelial cells are essential in maintaining the health and integrity of the ocular surface. However, very little is known about their physiological regulation. In this study, the cellular control mechanisms were explored, first to establish a defined culture system for the maintenance of primary epithelial cells from human meibomian glands and, second, to immortalize these cells, thereby developing a preclinical model that could be used to identify factors that regulate cell activity. Methods. Human meibomian glands were removed from lid segments after surgery, enzymatically digested, and dissociated. Isolated epithelial cells were cultured in media with or without serum and/or 3T3 feeder layers. To attempt immortalization, the cells were exposed to retroviral human telomerase reverse transcriptase (hTERT) and/or SV40 large T antigen cDNA vectors, and antibiotic-resistant cells were selected, expanded, and subcultured. Analyses for possible biomarkers, cell proliferation and differentiation, lipid-related enzyme gene expression, and the cellular response to androgen were performed with biochemical, histologic, and molecular biological techniques. Results. It was possible to isolate viable human meibomian gland epithelial cells and to culture them in serum-free medium. These cells proliferated, survived through at least the fifth passage, and contained neutral lipids. Infection with hTERT immortalized these cells, which accumulated neutral lipids during differentiation, expressed multiple genes for lipogenic enzymes, responded to androgen, and continued to proliferate. Conclusions. The results show that human meibomian gland epithelial cells may be isolated, cultured, and immortalized.

Liu, Shaohui; Hatton, Mark P.; Khandelwal, Payal

2010-01-01

262

Human Primary Lung Endothelial Cells in Culture  

PubMed Central

Pulmonary endothelial functions are critical to maintain the low pressure of the pulmonary circulation and effective diffusion capacity of the lung. To investigate pulmonary endothelial cell biology in healthy or diseased lungs, we developed methods to harvest and culture pure populations of primary pulmonary arterial endothelial cells and microvascular endothelial cells from human lung explanted at time of transplantation or from donor lungs not used in transplantation. The purity and characteristics of cultured endothelial cells is ascertained by morphologic criteria using phase contrast and electron microscopy; phenotypic expression profile for endothelial specific proteins such as endothelial nitric oxide synthase, platelet/endothelial cell adhesion molecule, and von Willbrand factor; and endothelial function assays such as Dil-acetylated low-density lipoprotein uptake and tube formation. This detailed method provides researchers with the ability to establish cells for molecular, genetic, and biochemical investigation of human pulmonary vascular diseases.

Xu, Weiling; Mavrakis, Lori; Aldred, Micheala A.; Asosingh, Kewal; Erzurum, Serpil C.

2012-01-01

263

The consensus mechanics of cultured mammalian cells  

PubMed Central

Although understanding cells' responses to mechanical stimuli is seen as increasingly important for understanding cell biology, how to best measure, interpret, and model cells' mechanical properties remains unclear. We determine the frequency-dependent shear modulus of cultured mammalian cells by using four different methods, both unique and well established. This approach clarifies the effects of cytoskeletal heterogeneity, ATP-dependent processes, and cell regional variations on the interpretation of such measurements. Our results clearly indicate two qualitatively similar, but distinct, mechanical responses, corresponding to the cortical and intracellular networks, each having an unusual, weak power-law form at low frequency. The two frequency-dependent responses we observe are remarkably similar to those reported for a variety of cultured mammalian cells measured with different techniques, suggesting it is a useful consensus description. Finally, we discuss possible physical explanations for the observed mechanical response.

Hoffman, Brenton D.; Massiera, Gladys; Van Citters, Kathleen M.; Crocker, John C.

2006-01-01

264

Media for culture of mammalian cells.  

PubMed

When mammalian cells are cultured in vitro, the investigator is attempting to reproduce the physiological environment in order to maintain and analyze normal functions and responses. The culture medium is an essential component of the in vitro environment and must be selected or designed with care. This unit provides guidelines for design of serum-containing and serum-free media, selective and specialty media, and media for growth under special conditions such as soft-agar growth. PMID:18228290

Sato, J D; Kan, M

2001-05-01

265

Comparative study on the cytotoxicity of different Myrtaceae essential oils on cultured vero and RC-37 cells.  

PubMed

Medicinally and commercially important essential oils from the family Myrtaceae, i.e. cajuput, clove, kanuka and manuka were phytochemically analysed by GC-MS. Cytotoxicity of these essential oils was evaluated in a standard neutral red assay. Maximum noncytotoxic concentrations for cajuput oil and clove oil were determined at 0.006%, kanuka oil and manuka oil were more cytotoxic with a maximum noncytotoxic concentration of 0.001%. The compounds alpha-pinene, eugenol and leptospermone demonstrated maximum noncytotoxic concentrations at dilutions of 0.001%, 0.003% and 0.001%, respectively. However, the terpene 1,8-cineole was about 100 times less toxic to cultured cells with a maximum noncytotoxic concentration of 0.1% and a TC50 value of 0.44%. Manuka essential oil exhibited high levels of virucidal activity against HSV-1 as well against drug-resistant HSV-1 isolates in viral suspension tests. Determination of cytotoxicity of natural products is an important prerequisite for application in cosmetic and health care products and in antiviral tests. PMID:19069246

Schnitzler, P; Wiesenhofer, K; Reichling, J

2008-11-01

266

The impact of cell culture equipment on energy loss.  

PubMed

Light energy of discrete wavelengths supplied via lasers and broadband intense pulsed light have been used therapeutically for many years. In vitro models complement clinical studies, especially for the elucidation of underlying mechanisms of action. Clarification that light energy reaches the cells is necessary when developing protocols for the treatment of cells using in vitro models. Few studies report on energy loss in cell culture equipment. The ability of energy from light with therapeutic potential to reach cells in culture needs to be determined; this includes determining the proportion of light energy lost within standard cell culture media and cell culture vessels. The energy absorption of cell culture media, with/without the pH indicator dye phenol red, and the loss of energy within different plastics and glassware used typically for in vitro cell culture were investigated using intense pulsed light and a yellow pulsed dye laser. Media containing phenol red have a distinctive absorption peak (560 nm) absent in phenol red-free media and restored by the addition of phenol red. For both light sources, energy loss was lowest in standard polystyrene tissue culture flasks or multi-well plates and highest in polypropylene vessels or glass tubes. The effects of phenol red-free media on the absorption of energy varied with the light source used. Phenol red-free media are the media of choice; polystyrene vessels with flat surfaces such as culture flasks or multi-well plates should be used in preference to polypropylene or glass vessels. PMID:23568625

Davies, Lleucu B; Kiernan, Michael N; Bishop, Joanna C; Thornton, Catherine A; Morgan, Gareth

2014-01-01

267

Canine coronavirus induces apoptosis in cultured cells  

Microsoft Academic Search

Canine coronavirus (CCoV) is widespread in dogs in several countries and causes mild enteric illness evolving to severe enteritis in young pups.In in vitro cultures canine coronaviruses generally induce extensive cell death, however nature of the events leading to cell death remains largely unknown.We analysed the induction of cytopathic effect by CCoV in a canine fibrosarcoma cell line (A-72) in

A. Ruggieri; L. Di Trani; I. Gatto; M. Franco; E. Vignolo; B. Bedini; G. Elia; C. Buonavoglia

2007-01-01

268

Chromosome preparation from cultured cells.  

PubMed

Chromosome (cytogenetic) analysis is widely used for the detection of chromosome instability. When followed by G-banding and molecular techniques such as fluorescence in situ hybridization (FISH), this assay has the powerful ability to analyze individual cells for aberrations that involve gains or losses of portions of the genome and rearrangements involving one or more chromosomes. In humans, chromosome abnormalities occur in approximately 1 per 160 live births(1,2), 60-80% of all miscarriages(3,4), 10% of stillbirths(2,5), 13% of individuals with congenital heart disease(6), 3-6% of infertility cases(2), and in many patients with developmental delay and birth defects(7). Cytogenetic analysis of malignancy is routinely used by researchers and clinicians, as observations of clonal chromosomal abnormalities have been shown to have both diagnostic and prognostic significance(8,9). Chromosome isolation is invaluable for gene therapy and stem cell research of organisms including nonhuman primates and rodents(10-13). Chromosomes can be isolated from cells of live tissues, including blood lymphocytes, skin fibroblasts, amniocytes, placenta, bone marrow, and tumor specimens. Chromosomes are analyzed at the metaphase stage of mitosis, when they are most condensed and therefore more clearly visible. The first step of the chromosome isolation technique involves the disruption of the spindle fibers by incubation with Colcemid, to prevent the cells from proceeding to the subsequent anaphase stage. The cells are then treated with a hypotonic solution and preserved in their swollen state with Carnoy's fixative. The cells are then dropped on to slides and can then be utilized for a variety of procedures. G-banding involves trypsin treatment followed by staining with Giemsa to create characteristic light and dark bands. The same procedure to isolate chromosomes can be used for the preparation of cells for procedures such as fluorescence in situ hybridization (FISH), comparative genomic hybridization (CGH), and spectral karyotyping (SKY)(14,15). PMID:24513647

Howe, Bradley; Umrigar, Ayesha; Tsien, Fern

2014-01-01

269

Ethylene Production by Plant Cell Cultures  

PubMed Central

Suspension cultures of Rosa sp., soybean (Glycine max L.), wheat (Triticum monococcum L.), sweet clover (Melilotus alba Desc.), Haplopappus gracilis Nutt., and rue (Ruta graveolens) produced ethylene. The amount varied with the species. The rate of formation in rose and Haplopappus cells paralleled growth but accelerated when the stationary phase was reached, after which the rate declined sharply. Light was not required for ethylene production. Exogenous ethylene could not replace 2,4-dichlorophenoxyacetic acid or naphthalineacetic acid in the cell cultures, and there was no stimulation of growth in the normal medium. Ethylene at 20 mm reduced growth of Ruta and rose cells by 30 and 20%, respectively. The amounts of ethylene produced by the cultures do not affect growth. Images

Larue, T. A. G.; Gamborg, O. L.

1971-01-01

270

Verbascoside production by plant cell cultures.  

PubMed

Verbascoside was found to be produced in all calli derived from eleven species that contained the compound in their leaves. Cell suspension cultures were also established in three species, i.e., Leucosceptrum japonicum f. barbinerve, Syringa josikaea, and Sy. vulgaris, all of which were found to produce verbascoside at more than 1 g/l. Of the three species, suspension cultures of L. japonicum f. barbinerve showed rapid growth and the highest yield of verbascoside (1.89 g/l). In these cultures, the effects of major salt concentration in B5 medium on cell growth and verbascoside production were examined. Maximum cell growth and maximum verbascoside production were both achieved by reducing the major salt concentration to half that of the original medium. PMID:24213785

Inagaki, N; Nishimura, H; Okada, M; Mitsuhashi, H

1991-01-01

271

Three dimensional culture of pineal cell aggregates: a model of cell-cell co-operation.  

PubMed

Three dimensional (3-D) cultures of pineal cell aggregates were obtained by constant gyratory shaking the heterogenous cell populations, obtained from the rat pineals, in the DMEM (Dulbecco's modified Eagle's medium). Within 4 days, the pineal cells became organized into a tissue like configuration appearing as a compact ball, evidenced by the scanning electron microscopy. The 3-D aggregates seemed to be mainly composed of pinealocytes (round-oval cells), glial (elongated cells) and other unknown cells. The heterogenous cells were separated by intercellular spaces. The ultrastructural characteristics revealed by transmission electron microscopy exhibited the presence of granular lysosomes, typical of pinealocytes actively involved in the secretion. These pineal cell aggregates secreted melatonin and other indole amines i.e. 5-methoxytryptamine (5-MT), indole acetic acid (IAA), 5-methoxy-3-indole acetic acid (5-MIAA), tryptophol (TOL) and 5-methoxytryptophol (5-MTL) in the culture medium, indicating the functional aspect of pinealocytes. The 3-D aggregates cultures had advantages over the pineal monolayer cultures as, after 4 days of culture, the amounts of indole amines secreted by 3-D aggregates were higher than those secreted by monolayer cultures. Besides, the 3-D aggregates remained functional till 24 days in the gyratory culture conditions. In the continuous perifusion system, the 3-D aggregates secreted melatonin while challanged with isoproterenol. This 3-D model of pineal cell aggregates might be useful, in future, to perform other kinetic studies of the release of indole amines in perifusion experiments as this system allows the maintenance of pineal cells for a long period of time. PMID:7550281

Khan, N A; Shacoori, V; Havouis, R; Querné, D; Moulinoux, J P; Rault, B

1995-05-01

272

Production of Zebrafish Offspring from Cultured Female Germline Stem Cells  

PubMed Central

Zebrafish female germline stem cell (FGSC) cultures were generated from a transgenic line of fish that expresses Neo and DsRed under the control of the germ cell specific promoter, ziwi [Tg(ziwi:neo);Tg(ziwi:DsRed)]. Homogeneous FGSC cultures were established by G418 selection and continued to express ziwi for more than 6 weeks along with the germ cell markers nanos3, dnd, dazl and vasa. A key component of the cell culture system was the use of a feeder cell line that was initiated from ovaries of a transgenic line of fish [Tg(gsdf:neo)] that expresses Neo controlled by the zebrafish gonadal soma derived factor (gsdf) promoter. The feeder cell line was selected in G418 and engineered to express zebrafish leukemia inhibitory factor (Lif), basic fibroblast growth factor (Fgf2) and glial-cell-line derived neurotrophic factor (Gdnf). These factors were shown to significantly enhance FGSC growth, survival and germline competency in culture. Results from cell transplantation experiments revealed that the cultured FGSCs were able to successfully colonize the gonad of sterile recipient fish and generate functional gametes. Up to 20% of surviving recipient fish that were injected with the cultured FGSCs were fertile and generated multiple batches of normal offspring for at least 6 months. The FGSC cultures will provide an in vitro system for studies of zebrafish germ cell growth and differentiation and their high frequency of germline transmission following transplantation could form the basis of a stem cell-mediated strategy for gene transfer and manipulation of the zebrafish genome.

Wong, Ten-Tsao; Tesfamichael, Abraham; Collodi, Paul

2013-01-01

273

Canine coronavirus induces apoptosis in cultured cells.  

PubMed

Canine coronavirus (CCoV) is widespread in dogs in several countries and causes mild enteric illness evolving to severe enteritis in young pups. In in vitro cultures canine coronaviruses generally induce extensive cell death, however nature of the events leading to cell death remains largely unknown. We analysed the induction of cytopathic effect by CCoV in a canine fibrosarcoma cell line (A-72) in order to characterize the apoptotic effect in homologous cell system. Following CCoV infection A-72 cell line, which is permissive to CCoV, showed reduced growth rate, as detected by MTT assay, a standard colorimetric assay for measuring cellular proliferation, and underwent to apoptotic death. Starting from 24h after CCoV infection, cells morphology appeared dramatically changed, with cells rounding and detachment from culture surface. Morphologic and biochemical features of apoptosis, such as blebbing of the plasma membrane, translocation of phosphatidilserine to cell surface and annexin V positive staining, nuclear fragmentation, apoptotic bodies formation and DNA laddering, were detected in CCoV-infected cells. Propidium iodide staining of infected culture indicated the appearance of hypodiploid DNA peak corresponding to apoptotic cell population. Commonly to other animal coronavirus infection caspase-3 is likely to contribute to the execution phase of apoptosis induced by CCoV in A-72 cells since we found activation of enzymatic activity as well as procaspase-3 activating cleavage. Apoptotic death of infected cells is detrimental as it causes cell and tissue destruction as well as inflammatory responses. Therefore in the case of CCoV associated gastroenteritis, apoptosis of epithelial mucosa cells may be responsible for pathology induced by CCoV infection. PMID:17254720

Ruggieri, A; Di Trani, L; Gatto, I; Franco, M; Vignolo, E; Bedini, B; Elia, G; Buonavoglia, C

2007-03-31

274

Comparative evaluation of maintenance of cell viability of an experimental transport media "coconut water" with Hank's balanced salt solution and milk, for transportation of an avulsed tooth: An in vitro cell culture study  

PubMed Central

The purpose of this study was to evaluate the efficiency of a new storage medium, coconut water, in comparison with other traditional storage media like Hank's balanced salt solution (HBBS) and milk, in maintaining the viability of an established cell line BHK-21/C13 (baby hamster kidney fibroblasts) using the direct suspension cell culture technique. The storage media tested in the study were divided into three major groups and two control groups - Group A: HBBS, Group B: milk, and Group C: coconut water. The positive and negative controls corresponded to 0-minute and 24-hour dry times respectively. The three groups were then divided into five subgroups, each denoting the storage time periods 15 min, 30 min, 45 min, 60 min and 120 min respectively. The cell line BHK-21/C13 was subcultured and the number of cells was standardized by making a cell suspension using Minimal Essential Medium in five culture plates. One ml of each experimental group (HBBS, milk and coconut water) was added to eight wells of each culture plate. The culture plates containing the cells and the experimental groups were incubated for the respective time periods. The cells were then counted with a Neubauer counting chamber, under light microscope. The results were statistically analyzed using One-way ANOVA and Multiple Range Test using the Tukey-HSD procedure to identify the significant groups at p ? 0.05. Within the parameters of this study, it appears that coconut water may be a better alternative to HBSS or milk, in terms of maintaining cell viability. Coconut water can be used as a superior transport medium for avulsed teeth.

Thomas, Toby; Gopikrishna, Velayutham; Kandaswamy, Deivanayagam

2008-01-01

275

Cell Culture on MEMS Platforms: A Review  

PubMed Central

Microfabricated systems provide an excellent platform for the culture of cells, and are an extremely useful tool for the investigation of cellular responses to various stimuli. Advantages offered over traditional methods include cost-effectiveness, controllability, low volume, high resolution, and sensitivity. Both biocompatible and bio-incompatible materials have been developed for use in these applications. Biocompatible materials such as PMMA or PLGA can be used directly for cell culture. However, for bio-incompatible materials such as silicon or PDMS, additional steps need to be taken to render these materials more suitable for cell adhesion and maintenance. This review describes multiple surface modification strategies to improve the biocompatibility of MEMS materials. Basic concepts of cell-biomaterial interactions, such as protein adsorption and cell adhesion are covered. Finally, the applications of these MEMS materials in Tissue Engineering are presented.

Ni, Ming; Tong, Wen Hao; Choudhury, Deepak; Rahim, Nur Aida Abdul; Iliescu, Ciprian; Yu, Hanry

2009-01-01

276

Milk Stimulates Growth of Prostate Cancer Cells in Culture  

Microsoft Academic Search

Concern has been expressed about the fact that cows’ milk contains estrogens and could stimulate the growth of hormone-sensitive tumors. In this study, organic cows’ milk and two commercial substitutes were digested in vitro and tested for their effects on the growth of cultures of prostate and breast cancer cells. Cows’ milk stimulated the growth of LNCaP prostate cancer cells

Patricia L. Tate; Robert Bibb; Lyndon L. Larcom

2011-01-01

277

Azo dyes and carcinogenic aromatic amines in cell cultures  

Microsoft Academic Search

Azo dyes are widely used in the food, pharmaceutical, cosmetic, textile and leather industries. They can be reduced by azoreductases in intestinal bacteria, liver cells and skin surface microflora so that aromatic amines are released. In this study an analytical system for the determination of carcinogenic aromatic amines at the picogram to femtogram level and a cell culture assay to

S. Hildenbrand; F. W. Schmahl; R. Wodarz; R. Kimmel; P. C. Dartsch

1999-01-01

278

Responses to steroids of Xiphophorus ACTH cells in organ culture  

Microsoft Academic Search

ACTH cells of the fish Xiphophorus responded to culture on a steroid-free medium by cytological changes that resulted in enlarged, rounded nuclei and enlarged nucleoli. These changes are interpreted as indicating an increase in the activity of the cells. A study of a range of steroids showed that, of the naturally occurring steroids, only cortisol would be effective at physiological

M. Sage

1968-01-01

279

Steroidogenesis in Porcine Follicle Cells Cultured in Serum-Free Media  

Microsoft Academic Search

The purpose of this study was to determine the steroid production of cultured porcine follicle cells grown in serum-free media. Theca cells (TC) and granulosa cells (GC) from large porcine follicles (greater than 8 mm) were dispersed and plated as monolayer cultures in serum-free media. Media were removed from the cultures at 3, 6, 12, 24, 48, 72, 96, and

Andrea L. Stein; Gere S. diZerega; Sharon A. Tonetta

1990-01-01

280

Development and validation of an integrated cell culture-qRTPCR assay for simultaneous quantification of coxsackieviruses, echoviruses, and polioviruses in disinfection studies.  

PubMed

This study demonstrated the applicability of integrated cell culture-quantitative RTPCR (ICC-qRTPCR) for the simultaneous quantification of coxsackievirus, echovirus, and poliovirus in disinfection studies. Buffalo green monkey cells were inoculated with a 10-fold dilution series of mixed enteroviruses and incubated prior to qRTPCR quantification. Optimal assay conditions included three post infection washes and a 24-hour post infection incubation period based on successful differentiation between infectious and noninfectious viruses and significant and consistent viral replication rates. Ultraviolet disinfection studies were performed to validate the ICC-qRTPCR assay. Using the optimized assay, three-log microbial inactivation was achieved at UV doses of 30-44, 28-42, and 28-29 mJ/cm(2) for coxsackievirus B6, echovirus 12, and poliovirus 1, respectively. These results compare favorably to side-by-side assessments using conventional cultural techniques and values previously reported in the literature. This indicates that ICC-qRTPCR is a practical alternative for the simultaneous quantification of enteroviruses in disinfection studies. PMID:20107264

Mayer, B K; Ryu, H; Gerrity, D; Abbaszadegan, M

2010-01-01

281

Cell culture in vivo by means of diffusion chamber system.  

PubMed

In a diffusion chamber (DC) system, cells are cultured in vivo - hence making it possible to minimize infection and foreign material contamination. In view of this merit, we devised a technique to combine a DC system and a scaffold to the end of incubating sufficient host cells for grafting. In the present study, PLGA sponge and rat bone marrow cells were encapsulated inside a DC and then placed inside the abdominal cavities of rats. DCs were removed at two or four weeks after grafting. At four weeks after grafting, fibrous and calcified tissue matching the shape of the PLGA sponge was formed. These results suggested that the PLGA sponge was an effective scaffolding material in inducing three-dimensional tissue formation and that combination with a DC system resulted in a cell mass matching the scaffold shape. In addition, the cells were cultured in vivo - which meant that DC culturing did not require special incubation facilities or technologies after grafting. PMID:19721273

Nakano, Kenjiro; Hayashi, Tatsuhide; Kawai, Hideki; Takei, Yukiko; Sato, Yosuke; Ando, Kimitoshi; Ono, Yuzo; Jinno, Satoshi; Kawakami, Toshiyuki; Maeda, Hatuhiko; Kawai, Tatsushi

2009-07-01

282

Studies on batch and continuous cultures of Botryococcus braunii: hydrocarbon production in relation to physiological state, cell ultrastructure, and phosphate nutrition  

Microsoft Academic Search

The growth of the hydrocarbon-rich alga Botryococcus braunii was studied under air-lift conditions using batch and continuous cultures. Large variations in the physiological state of B. braunii were achieved in batch cultures and in continuous cultures with various dilution rates. The possible effects of these variations upon hydrocarbons (nature, relative abundance, location, level, productivity) and also on the production of

E. Casadevall; D. Dif; C. Largeau; C. Gudin; D. Chaumont; O. Desanti

1985-01-01

283

The culture of human embryonic stem cells in microchannel perfusion bioreactors  

NASA Astrophysics Data System (ADS)

The culture of human Embryonic Stem (ES) cells in microchannel bioreactors can be highly beneficial for ES cell biology studies and ES tissue engineering applications. In the present study we examine the use of Human Foreskin Fibroblasts (HFF) cells as feeder cells for human ES culture in a microchannel perfusion bioreactor. PDMS microchannels (depth:130 micron) were fabricated using conventional soft-lithography techniques. The channels were sterilized, coated with a human fibronectin solution and seeded with cells. Following a period of static incubation, culture medium was perfused through the channels at various flow rates and cell growth was monitored throughout the culture process. Mass transport and fluid mechanics models were used to evaluate the culture conditions (shear stress, oxygen levels within the micro-bioreactor as a function of the medium flow rate. The conditions for successful long-term culture (>7 days) of HFF under flow were established. Experiments with human embryonic stem cells cultured in microchannels show that the conditions essential to co-culture human ES cell on HFF cells under perfusion differ from the conditions necessary for HFF cell culture. Human ES cells were found to be highly sensitive to flow and culture conditions and did not grow under flow rates which were suitable for HFF long-term culture. Successful culture of undifferentiated human ES cell colonies in a perfusion micro-bioreactor is a basic step towards utilizing microfluidic techniques to explore stem cell biology.

Korin, Natanel; Bransky, Avishay; Dinnar, Uri; Levenberg, Shulamit

2007-12-01

284

Cultured cells in cystic fibrosis research: A review.  

PubMed

Cystic fibrosis (CF) is a common inherited disorder which is characterized by the production of exocrine secretions with elevated ion content and abnormally viscous mucus. Over the last few years cells obtained from the peripheral blood or cultured from tissues of cystic fibrosis patients have been used increasingly in the study of the disease. Investigations of the following properties of cystic fibrosis cells are reviewed: morphology, ultrastructure, growth kinetics, cellular metachromasia, the production of ciliary inhibitors, cellular composition, plasma membrane composition, the transport of inorganic ions and small organic molecules, lysosomal enzyme content, and RNA methylation. Studies of the effects on cultured cells and erythrocyte membranes of factors in CF cell culture medium and biological fluids from CF patients are discussed. PMID:186908

Ward, J B

1976-01-01

285

Comparative SAXS and DSC study on stratum corneum structural organization in an epidermal cell culture model (ROC): impact of cultivation time.  

PubMed

Cell cultured skin equivalents present an alternative for dermatological in vitro evaluations of drugs and excipients as they provide the advantage of availability, lower variability and higher assay robustness compared to native skin. For penetration/permeation studies, an adequate stratum corneum barrier similar to that of human stratum corneum is, however, a prerequisite. In this study, the stratum corneum lipid organization in an epidermal cell culture model based on rat epidermal keratinocytes (REK organotypic culture, ROC) was investigated by small-angle X-ray scattering (SAXS) in dependence on ROC cultivation time and in comparison to native human and rat stratum cornea. In addition, the thermal phase behavior was studied by differential scanning calorimetry (DSC) and barrier properties were checked by measurements of the permeability of tritiated water. The development of the barrier of ROC SC obtained at different cultivation times (7, 14 and 21 days at the air-liquid interface) was connected with an increase in structural order of the SC lipids in SAXS measurements: Already cultivation for 14 days at the air-liquid interface resulted overall in a competent SC permeability barrier and SC lipid organization. Cultivation for 21 days resulted in further minor changes in the structural organization of ROC SC. The SAXS patterns of ROC SC had overall large similarities with that of human SC and point to the presence of a long periodicity phase with a repeat distance of about 122Å, e.g. slightly smaller than that determined for human SC in the present study (127Å). Moreover, SAXS results also indicate the presence of covalently bound ceramides, which are crucial for a proper SC barrier, although the corresponding thermal transitions were not clearly detectable by DSC. Due to the competent SC barrier properties and high structural and organizational similarity to that of native human SC, ROC presents a promising alternative for in vitro studies, particularly as it can be obtained under overall rather straightforward cell culture conditions and thus low assay costs. PMID:23770376

Kuntsche, Judith; Herre, Angela; Fahr, Alfred; Funari, Sérgio S; Garidel, Patrick

2013-12-18

286

Isolation, culture, and verification of human sweat gland epithelial cells  

PubMed Central

Human sweat gland epithelial cells (SGECs) have been isolated and grown in vitro, However, slow proliferation makes the culture of these cells extremely difficult. The present study was carried out to explore the modified culture medium for SGECs in vitro. Full-thickness skin samples were minced (1 mm3) and digested overnight with type II collagenase. The gland coils were removed under an inverted phase-contrast microscope. An adherent culture method was used to isolate and culture SGECs. Staining with hematoxylin and eosin was performed, followed by observation of the morphologic features of these cells. Immunofluorescence staining with antibodies to cytokeratins CK7, CK18, and CK19 and carcinoembryonic antigen (CEA) was performed to verify the presence of SGECs. Growth curves by MTT were created for cells grown in serum-free keratinocyte medium and in modified keratinocyte medium containing 2.5% fetal bovine serum (FBS). One week after culturing, the cells grew well and were polygonal or irregular in shape by inverted phase contrast microscopy. Cell fusion, with a characteristic paving-stone arrangement, reached 100% after approximately 3 weeks in culture. Immunofluorescence staining indicated expression of CK7, CK18, CK19, and CEA. Compared with SGECs grown in serum-free keratinocyte medium, the proliferation of SGECs grown in modified culture medium with low concentration of FBS at days 6, 9, and 12 was significantly accelerated (p < 0.05). This study suggests that keratinocyte medium supplemented with 2.5% FBS is effective and suitable for the culture of SGECs. Electronic supplementary material The online version of this article (doi:10.1007/s10616-010-9303-z) contains supplementary material, which is available to authorized users.

Tao, Ran; Han, Yanfu; Li, Dongjie; Sun, Tianjun

2010-01-01

287

[Culture and identification of rabbit cavernosal endothelial cells].  

PubMed

The objective of this study was to establish a protocol for isolating, culturing, proliferating cavernosal endothelial cells, and to obtain large number of autologous cavernosal endothelial cells for tissue-engineered substitutes. Cavernosal tissues were either minced into 1 to 2 mm3 pieces and incubated with 0.02% collagenase IV for 2h or first minced into 20 mm3 then incubated with 0.05% elastase for 1h, 2h or 3h, respectively; the undigested tissue blocks were repeatedly squeezed with a spatula for 2 min. Cells were collected and cultured with supplemented endothelial cell growth medium. Morphology and expansion of the cells were observed. Cell-type specific proteins CD31 and vWF were analyzed by immunohistochemical methods. The results revealed that cell isolation with 0.05% elastase for 2h followed by additional squeezing of residual tissue was effective not only for cell isolation, but also for preventing the tissue from getting contaminated by stromal cells, which was better than cell isolation with collagenase IV. Cavernosal endothelial cells were found with a typical cobblestone morphology and could be passaged 7 passages. Immunohistochemistry showed that endothelial specific proteins CD31 and vWF were positive. These results suggest that the isolation of cavernosal endothelial cells is simple and effective, the cells proliferate rapidly and they can be passaged easily. This method of new cultures will be of benefit to penile tissue engineering. PMID:18788303

Wei, Yun; Wei, Lei

2008-08-01

288

Identification of cultured progenitor cells from human marrow stroma.  

PubMed

The marrow stromal cells (MSC) are essential for regulation of bone remodeling and hematopoiesis. It is of prime importance to isolate MSC and to expand the proliferating cells ex vivo. In this study, we analyzed cultured MSC for various cellular parameters, including cell morphology, cell cycle, and expression of cell surface antigens by flow cytometry. MSC were divided based on cell size to small (S-cells) and large (L-cells) and were visualized by light and electron microscope. The S-cells were proliferating cells correlated with G0/G1 phase of cell cycle, and expressed cFOS. The expression of surface markers CD-34, -44, -51, -61, -62E, -62P, -62L was quantified using flow cytometry. CD-44 was ubiquitously expressed by S and L cells, CD-51 and -61 were expressed by 30%-38% of S-cells. CD-34 and -62 expressed 20% positive of the analyzed cells that were of the proliferating progenitors (S-cells). This study enables the identification of subpopulations from MSC with special attention paid to the proliferating cells from ex vivo cultures of marrow stroma. PMID:12210721

Shur, I; Marom, R; Lokiec, F; Socher, R; Benayahu, D

2002-01-01

289

Cell of the mucous membrane of the female genital tract in culture: A comparative study with regard to the histogenesis of endometriosis  

Microsoft Academic Search

Summary  Cellular elements from the mucous membrane of the uterus and oviducts and from peritoneal washings were cultured. The in vitro\\u000a behavior of these cells was compared to elucidate the histogenesis of endometriosis and the role of various diagnostic procedures.\\u000a \\u000a In 65% of the cultured matrial obtained by uterine-tubal flushing, proliferating cells of the uterine-tubal mucous membrane\\u000a were present. Their morphology

Gertrude Mungyer; Wim N. P. Willemsen; Rune Rolland; Hans M. Vemer; Francs C. S. Ramaekers; Paul H. K. Jap; Lambert G. Poels

1987-01-01

290

Multifunction Co-culture Model for Evaluating Cell-Cell Interactions  

PubMed Central

Interactions within the same cell population (homotypic) and between different cell types (heterotypic) are essential for tissue development, repair, and homeostasis. To elucidate the underlying mechanisms of these cellular interactions, co-culture models have been used extensively to investigate the role of cell–cell physical contact, autocrine and/or paracrine interactions on cell function, as well as stem cell differentiation. Specifically, the mixed co-culture model is often optimal for interpreting the effects of cell–cell contact on cellular behavior in vitro, while indirect co-culture can be used to study the effects of paracrine signaling on cell reactions. Additionally, cell–cell contact can be controlled by establishing physical barriers, which are used to regulate spatial and temporal cell distribution patterns in co-culture. In this chapter, we describe a method for forming a removable permeable divider for temporally and spatially controlling cellular interactions. This model can be used to study the impact of both cell–cell contact and paracrine signaling on the behavior of the mixed population as a whole and on the response of each subpopulation of cells in co-culture.

Bogdanowicz, Danielle R.; Lu, Helen H.

2014-01-01

291

High Frequency Retrotransposition in Cultured Mammalian Cells  

Microsoft Academic Search

We previously isolated two human L1 elements (L1.2 and LRE2) as the progenitors of disease-producing insertions. Here, we show these elements can actively retrotranspose in cultured mammalian cells. When stably expressed from an episome in HeLa cells, both elements retrotransposed into a variety of chromosomal locations at a high frequency. The retrotransposed products resembled endogenous L1 insertions, since they were

John V Moran; Susan E Holmes; Thierry P Naas; Ralph J DeBerardinis; Jef D Boeke; Haig H Kazazian

1996-01-01

292

Shape memory polymers for active cell culture.  

PubMed

Shape memory polymers (SMPs) are a class of "smart" materials that have the ability to change from a fixed, temporary shape to a pre-determined permanent shape upon the application of a stimulus such as heat(1-5). In a typical shape memory cycle, the SMP is first deformed at an elevated temperature that is higher than its transition temperature, T(trans;) [either the melting temperature (T(m;)) or the glass transition temperature (T(g;))]. The deformation is elastic in nature and mainly leads to a reduction in conformational entropy of the constituent network chains (following the rubber elasticity theory). The deformed SMP is then cooled to a temperature below its T(trans;) while maintaining the external strain or stress constant. During cooling, the material transitions to a more rigid state (semi-crystalline or glassy), which kinetically traps or "freezes" the material in this low-entropy state leading to macroscopic shape fixing. Shape recovery is triggered by continuously heating the material through T(trans;) under a stress-free (unconstrained) condition. By allowing the network chains (with regained mobility) to relax to their thermodynamically favored, maximal-entropy state, the material changes from the temporary shape to the permanent shape. Cells are capable of surveying the mechanical properties of their surrounding environment(6). The mechanisms through which mechanical interactions between cells and their physical environment control cell behavior are areas of active research. Substrates of defined topography have emerged as powerful tools in the investigation of these mechanisms. Mesoscale, microscale, and nanoscale patterns of substrate topography have been shown to direct cell alignment, cell adhesion, and cell traction forces(7-14). These findings have underscored the potential for substrate topography to control and assay the mechanical interactions between cells and their physical environment during cell culture, but the substrates used to date have generally been passive and could not be programmed to change significantly during culture. This physical stasis has limited the potential of topographic substrates to control cells in culture. Here, active cell culture (ACC) SMP substrates are introduced that employ surface shape memory to provide programmed control of substrate topography and deformation. These substrates demonstrate the ability to transition from a temporary grooved topography to a second, nearly flat memorized topography. This change in topography can be used to control cell behavior under standard cell culture conditions. PMID:21750496

Davis, Kevin A; Luo, Xiaofan; Mather, Patrick T; Henderson, James H

2011-01-01

293

Wound Coverage by Cultured Skin Cells.  

National Technical Information Service (NTIS)

The major purpose of our work is to refine the technology for growth of human epidermal cells to achieve more rapid growth in vitro and easier handling of tissue cultured materials in clinics. It is also to evaluate the possibilities for the use of alloge...

M. Eisinger E. M. Duffy

1985-01-01

294

Prevention and Detection of Mycoplasma Contamination in Cell Culture  

PubMed Central

One of the main problems in cell culture is mycoplasma infection. It can extensively affect cell physiology and metabolism. As the applications of cell culture increase in research, industrial production and cell therapy, more concerns about mycoplasma contamination and detection will arise. This review will provide valuable information about: 1. the ways in which cells are contaminated and the frequency and source of mycoplasma species in cell culture; 2. the ways to prevent mycoplasma contamination in cell culture; 3. the importance of mycoplasma tests in cell culture; 4. different methods to identify mycoplasma contamination; 5. the consequences of mycoplasma contamination in cell culture and 6. available methods to eliminate mycoplasma contamination. Awareness about the sources of mycoplasma and pursuing aseptic techniques in cell culture along with reliable detection methods of mycoplasma contamination can provide an appropriate situation to prevent mycoplasma contamination in cell culture.

Nikfarjam, Laleh; Farzaneh, Parvaneh

2012-01-01

295

Cell wall proteomics of sugarcane cell suspension cultures.  

PubMed

The use of cell walls to produce cellulosic ethanol from sugarcane bagasse is a new challenge. A better knowledge of proteins involved in cell wall remodelling is essential to improve the saccharification processes. Cell suspension cultures were used for this first cell wall proteomics study of sugarcane. Proteins extracted from cell walls were identified using an adapted protocol. They were extracted using 0.2 M CaCl2 and 2 M LiCl after purification of cell walls. The proteins were then identified by the innovative nanoACQUITY UPLC MS/MS technology and bioinformatics using the translated SUCEST EST cluster database of sugarcane. The experiments were reproduced three times. Since Sorghum bicolor is the closest plant with a fully sequenced genome, homologous proteins were searched for to complete the annotation of proteins, that is, prediction of subcellular localization and functional domains. Altogether, 69 different proteins predicted to be secreted were identified among 377 proteins. The reproducibility of the experiments is discussed. These proteins were distributed into eight functional classes. Oxidoreductases such as peroxidases were well represented, whereas glycoside hydrolases were scarce. This work provides information about the proteins that could be manipulated through genetic transformation, to increase second-generation ethanol production. PMID:24436144

Calderan-Rodrigues, Maria Juliana; Jamet, Elisabeth; Bonassi, Maria Beatriz Calderan Rodrigues; Guidetti-Gonzalez, Simone; Begossi, Amanda Carmanhanis; Setem, Laís Vaz; Franceschini, Livia Maria; Fonseca, Juliana Guimarães; Labate, Carlos Alberto

2014-03-01

296

Automation of 3-dimensional cell culture in arrayed microfluidic devices  

PubMed Central

The increasing interest in studying the interactions between cells and the extracellular matrix (ECM) has created a need for high throughput low cost three-dimensional (3D) culture systems. The recent development of tubeless microfluidics via passive pumping provides a high throughput microchannel culture platform compatible with existing high throughput infrastructures (e.g. automated liquid handlers). Here we build on a previously reported high throughput two-dimensional (2D) system to create a robust automated system for 3D culture. Operational controls including temperature and sample handling have been characterized and automated. Human mammary fibroblasts (HMFs) suspended in type-I collagen are loaded and cultured in microchannel arrays, and used to optimize the system operational parameters. A Peltier cooler maintains the collagen as a liquid at 4°C during cell seeding, followed by polymerization at 37°C. Optimization of this platform is discussed (e.g. controlling collagen contraction, increasing cell viability, preventing the removal of microchannel contents), and 3D distribution of HMFs is examined by fluorescent microscopy. Finally, we validate the platform by automating a previously developed 3D breast carcinoma co-culture assay. The platform allows more efficient 3D culture experiments and lays the foundation for high throughput studies of cell-ECM interactions.

Montanez-Sauri, Sara I.; Sung, Kyung Eun; Puccinelli, John P.; Pehlke, Carolyn; Beebe, David J.

2011-01-01

297

Self-reporting scaffolds for 3-dimensional cell culture.  

PubMed

Culturing cells in 3D on appropriate scaffolds is thought to better mimic the in vivo microenvironment and increase cell-cell interactions. The resulting 3D cellular construct can often be more relevant to studying the molecular events and cell-cell interactions than similar experiments studied in 2D. To create effective 3D cultures with high cell viability throughout the scaffold the culture conditions such as oxygen and pH need to be carefully controlled as gradients in analyte concentration can exist throughout the 3D construct. Here we describe the methods of preparing biocompatible pH responsive sol-gel nanosensors and their incorporation into poly(lactic-co-glycolic acid) (PLGA) electrospun scaffolds along with their subsequent preparation for the culture of mammalian cells. The pH responsive scaffolds can be used as tools to determine microenvironmental pH within a 3D cellular construct. Furthermore, we detail the delivery of pH responsive nanosensors to the intracellular environment of mammalian cells whose growth was supported by electrospun PLGA scaffolds. The cytoplasmic location of the pH responsive nanosensors can be utilized to monitor intracellular pH (pHi) during ongoing experimentation. PMID:24299732

Harrington, Helen; Rose, Felicity R A J; Aylott, Jonathan W; Ghaemmaghami, Amir M

2013-01-01

298

Advanced Cell Culture Techniques for Cancer Drug Discovery  

PubMed Central

Human cancer cell lines are an integral part of drug discovery practices. However, modeling the complexity of cancer utilizing these cell lines on standard plastic substrata, does not accurately represent the tumor microenvironment. Research into developing advanced tumor cell culture models in a three-dimensional (3D) architecture that more prescisely characterizes the disease state have been undertaken by a number of laboratories around the world. These 3D cell culture models are particularly beneficial for investigating mechanistic processes and drug resistance in tumor cells. In addition, a range of molecular mechanisms deconstructed by studying cancer cells in 3D models suggest that tumor cells cultured in two-dimensional monolayer conditions do not respond to cancer therapeutics/compounds in a similar manner. Recent studies have demonstrated the potential of utilizing 3D cell culture models in drug discovery programs; however, it is evident that further research is required for the development of more complex models that incorporate the majority of the cellular and physical properties of a tumor.

Lovitt, Carrie J.; Shelper, Todd B.; Avery, Vicky M.

2014-01-01

299

Advanced cell culture techniques for cancer drug discovery.  

PubMed

Human cancer cell lines are an integral part of drug discovery practices. However, modeling the complexity of cancer utilizing these cell lines on standard plastic substrata, does not accurately represent the tumor microenvironment. Research into developing advanced tumor cell culture models in a three-dimensional (3D) architecture that more prescisely characterizes the disease state have been undertaken by a number of laboratories around the world. These 3D cell culture models are particularly beneficial for investigating mechanistic processes and drug resistance in tumor cells. In addition, a range of molecular mechanisms deconstructed by studying cancer cells in 3D models suggest that tumor cells cultured in two-dimensional monolayer conditions do not respond to cancer therapeutics/compounds in a similar manner. Recent studies have demonstrated the potential of utilizing 3D cell culture models in drug discovery programs; however, it is evident that further research is required for the development of more complex models that incorporate the majority of the cellular and physical properties of a tumor. PMID:24887773

Lovitt, Carrie J; Shelper, Todd B; Avery, Vicky M

2014-01-01

300

Development of primary cell culture from Scylla serrata  

PubMed Central

This paper reports for the first time, the Primary cell culture of hepatopancreas from edible crab Scylla serrata using crab saline, L-15 (Leibovitz), 1 × L-15 + crab saline, 2 × L-15 + crab saline, 3 × L-15 and citrate buffer without any serum. We could isolate and maintain E (Embryonalzellen), F (Fibrenzellen), B (Blasenzellen), R (Restzellen) and G (Granular cells). Upon seeding the hepatopancreatic E, F, B, and R cells showed different survival pattern over time than granular cells. A modified L-15 (3×) medium supported the best survival of hepatopancreatic E, F B, and R cells in in-vitro culture. However granular cells could be maintained for 184 days with L-15 (1×) + crab saline. Fetal bovine serum was not effective additive and hampered cell viability in present study.

Sashikumar, Anu

2008-01-01

301

Biodegradable thermogelling poly[(R)-3-hydroxybutyrate]-based block copolymers: micellization, gelation, and cytotoxicity and cell culture studies.  

PubMed

A series of biodegradable multiblock poly(ester urethane)s having poly[(R)-3-hydroxybutyrate] (PHB), poly(ethylene glycol) (PEG), and poly(propylene glycol) (PPG) segments was prepared. The critical micellization concentration (CMCs) of these water-soluble poly(ester urethane)s were determined at different temperatures in order to calculate the thermodynamic parameters for the process of micelle formation. The process for micelle formation was found to be entropy-driven. The thermogelling behavior of the aqueous polymer solution was studied by (1)H and (13)C NMR spectroscopy at different temperatures. We obtained valuable molecular level information regarding the state of the copolymer in solution based on the variation of the peak widths. Cytotoxicity studies performed on the extracts of the copolymer gel indicate good cell compatibility. Cells attach on the surface of the gel much better than on the commercially available PEG-PPG-PEG triblock copolymer. These studies indicate a potential for the copolymer gel to be used for tissue engineering applications. PMID:19663517

Loh, Xian Jun; Goh, Suat Hong; Li, Jun

2009-09-01

302

Induction of a metabolic switch in insect cells by substrate-limited fed batch cultures  

Microsoft Academic Search

Insect cell metabolism was studied in substrate-limited fed batch cultures of Spodoptera frugiperda (Sf-9) cells. Results from a glucose-limited culture, a glutamine-limited culture, a culture limited in both glucose and glutamine and a batch culture were compared. A stringent relation between glucose excess and alanine formation was found. In contrast, glucose limitation induced ammonium formation, while, at the same time,

L. Öhman; J. Ljunggren; L. Häggström

1995-01-01

303

Rice suspension cultured cells are evaluated as a model system to study salt responsive networks in plants using a combined proteomic and metabolomic profiling approach.  

PubMed

Salinity is one of the major abiotic stresses affecting plant productivity but surprisingly, a thorough understanding of the salt-responsive networks responsible for sustaining growth and maintaining crop yield remains a significant challenge. Rice suspension culture cells (SCCs), a single cell type, were evaluated as a model system as they provide a ready source of a homogenous cell type and avoid the complications of multicellular tissue types in planta. A combination of growth performance, and transcriptional analyses using known salt-induced genes was performed on control and 100 mM NaCl cultured cells to validate the biological system. Protein profiling was conducted using both DIGE- and iTRAQ-based proteomics approaches. In total, 106 proteins were identified in DIGE experiments and 521 proteins in iTRAQ experiments with 58 proteins common to both approaches. Metabolomic analysis provided insights into both developmental changes and salt-induced changes of rice SCCs at the metabolite level; 134 known metabolites were identified, including 30 amines and amides, 40 organic acids, 40 sugars, sugar acids and sugar alcohols, 21 fatty acids and sterols, and 3 miscellaneous compounds. Our results from proteomic and metabolomic studies indicate that the salt-responsive networks of rice SCCs are extremely complex and share some similarities with thee cellular responses observed in planta. For instance, carbohydrate and energy metabolism pathways, redox signaling pathways, auxin/indole-3-acetic acid pathways and biosynthesis pathways for osmoprotectants are all salt responsive in SCCs enabling cells to maintain cellular function under stress condition. These data are discussed in the context of our understanding of in planta salt-responses. PMID:23661342

Liu, Dawei; Ford, Kristina L; Roessner, Ute; Natera, Siria; Cassin, Andrew M; Patterson, John H; Bacic, Antony

2013-06-01

304

Monolayer culture of cells originating from apreimplantation bovine embryo  

Microsoft Academic Search

Summary  The objective of this study was to establish a method by which trophectodermal cells originating from individual preimplantation\\u000a bovine embryos could be perpetuated in monolayer culture. A single, Day-11 bovine embryo collected nonsurgically from a mixed-breed\\u000a beef cow was cultured in Ham's F10 medium supplemented with fetal bovine serum, sodium pyruvate, insulin and epidermal growth\\u000a factor. After 13 d in

D. A. Stringfellow; B. W. Gray; L. H. Lauerman; M. S. Thomson; P. J. Rhodes; R. C. Bird

1987-01-01

305

Bacterial cellulose as a substrate for microbial cell culture.  

PubMed

Bacterial cellulose (BC) has a range of structural and physicochemical properties that make it a particularly useful material for the culture of bacteria. We studied the growth of 14 genera of bacteria on BC substrates produced by Acetobacter xylinum and compared the results to growth on the commercially available biopolymers agar, gellan, and xanthan. We demonstrate that BC produces rates of bacterial cell growth that typically exceed those on the commercial biopolymers and yields cultures with higher titers of cells at stationary phase. The morphology of the cells did not change during growth on BC. The rates of nutrient diffusion in BC being higher than those in other biopolymers is likely a primary factor that leads to higher growth rates. Collectively, our results suggest that the use of BC may open new avenues in microbiology by facilitating bacterial cell culture and isolation. PMID:24441155

Yin, Na; Santos, Thiago M A; Auer, George K; Crooks, John A; Oliver, Piercen M; Weibel, Douglas B

2014-03-01

306

Characterization and culture of fetal rhesus monkey renal cortical cells.  

PubMed

The renal glomerulus is composed of endothelial and mesangial cells with podocytes contributing to glomerular filtration. Podocyte damage is associated with renal disorders, thus there is interest in these cells for regenerative medicine. These studies investigated the use of extracellular matrix (ECM) to grow third trimester fetal monkey renal cortical cells and to assess mature podocytes in culture. Immunohistochemistry provided a profile of podocyte differentiation with metanephric mesenchyme and developing podocytes nestin positive and synaptopodin negative, whereas mature podocytes were positive for both markers. Primary cell cultures devoid of mature podocytes were established on plastic and renal ECM. A cell population (nestin+/synatopodin-) cultured on renal ECM showed greater proliferative potential compared with plastic with limited podocytes developing in culture over time. Further investigation of individual components of ECM (laminin, fibronectin, collagen I, or collagen IV) indicated that collagen I supported the greatest proliferation similar to renal ECM, whereas a greater number of mature podocytes (nestin+/synaptopodin+) were observed on fibronectin. These results suggest that (1) culture of fetal monkey podocytes can be accomplished, (2) renal ECM and collagen I can support renal cortical cells in vitro, which may recapitulate the developing kidney in vivo, and (3) fibronectin can support podocyte differentiation in vitro. PMID:19581826

Leapley, Alyssa C; Lee, C Chang I; Batchelder, Cynthia A; Yoder, Mervin C; Matsell, Douglas G; Tarantal, Alice F

2009-10-01

307

Characterization and Culture of Fetal Rhesus Monkey Renal Cortical Cells  

PubMed Central

The renal glomerulus is composed of endothelial and mesangial cells with podocytes contributing to glomerular filtration. Podocyte damage is associated with renal disorders, thus there is interest in these cells for regenerative medicine. These studies investigated the use of extracellular matrix (ECM) to grow third trimester fetal monkey renal cortical cells and to assess mature podocytes in culture. Immunohistochemistry provided a profile of podocyte differentiation with metanephric mesenchyme and developing podocytes nestin positive and synaptopodin negative, whereas mature podocytes were positive for both markers. Primary cell cultures devoid of mature podocytes were established on plastic and renal ECM. A cell population (nestin+/synatopodin?) cultured on renal ECM showed greater proliferative potential compared to plastic with limited podocytes developing in culture over time. Further investigation of individual components of ECM (laminin, fibronectin, collagen I or IV) indicated that collagen I supported the greatest proliferation similar to renal ECM, whereas a greater number of mature podocytes (nestin+/synaptopodin+) were observed on fibronectin. These results suggest: (1) culture of fetal monkey podocytes can be accomplished, (2) renal ECM and collagen I can support renal cortical cells in vitro which may recapitulate the developing kidney in vivo, and (3) fibronectin can support podocyte differentiation in vitro.

Leapley, Alyssa C.; Lee, C. Chang I.; Batchelder, Cynthia A.; Yoder, Mervin C.; Matsell, Douglas G.; Tarantal, Alice F.

2011-01-01

308

Phenolic compounds of a culture of Alhagi kirghisorum cells  

Microsoft Academic Search

A comparative analysis has been made of a series of phenolic compounds in the initial plant and in a cell culture ofAlhagi kirghisorum. Quercetin, isorhamnetin, isorhamnetin 3-O-neohesperoside, retusin, 8-methylretusin, calycosin and formononetin were isolated from the cultivated cells and identified. Features of the formation of various classes of phenolic compounds in the cultivated cells have been studied by chromatographic methods.

O. A. Sapko; R. M. Kunaeva

1999-01-01

309

[Serum-free culture of umbilical cord mesenchymal stem cells].  

PubMed

This study was purposed to observe the culture of umbilical cord mesenchymal stem cells (UC-MSC) with serum-free medium, and compared it with the medium containing 10% fetal bovine serum (FBS). The normal umbilical cords were acquired during cesarean section, and then were cultured with MesenCult-XF serum-free medium or medium containing 10% fetal bovine serum (FBS). The morphology, immunophenotype, cell cycle, proliferation and differentiation potential of mesenchymal stem cells and the inhibition of mixed lymphocyte reaction were observed through different medium culture method. The results showed that the MSC cultured with serum-free MesenCult(-)XF medium could transfer and multiply for average of 6.57 ± 0.7 times, and the serum medium-cultured MSC could transfer and multiply for average of 4.59 ± 0.45 times (P < 0.05). Two kinds of medium cultured MSC all expressed CD44, CD90, CD73, CD105 antigen, but did not expressed CD31, CD45, HLA-DR and CD34 antigen, and their expression levels were not significantly different. The serum-free medium-cultured MSC (65 ± 5.2%) were all at Go/G1 phase, and the serum-contained medium-cultured MSC (62+3.1%) were at Go/G1 phase(P > 0.05); the 2 kinds of media-cultured MSC all could differentiate into fat and ossification; when serum-free medium cultured umbilical cord MSC were inoculated at the the density of 10(3), 5×10(3), 10(4), and 2×10(4) cells/well, then co-cultured with the reactant and stimulating cells, the CPM were (6.43 ± 0.47)×10(4), (4.30 ± 0.38)×10(4), (1.97 ± 0.13)×10(4) and (0.24 ± 0.03)×10(4), respectively, and the serum-containing medium-cultured MSC were incubated with different density of mixed lymphocyte, displaying CPM that were (7.85 ± 0.07)×10(4), (5.64 ± 0.12)×10(4), (3.09 ± 0.18)×10(4) and (1.73 ± 0.05)×10(4). It is concluded that the serum-free medium has been confirmed to culture MSC, which have potential of transfer and differentiation with count for clinical application, and can avoid foreign protein sensitization. PMID:24156445

Zhou, Ping; Li, Dan; Chen, Guang-Hua; Wang, Yi

2013-10-01

310

Plant cell cultures: bioreactors for industrial production.  

PubMed

The recent biotechnology boom has triggered increased interest in plant cell cultures, since a number of firms and academic institutions investigated intensively to rise the production of very promising bioactive compounds. In alternative to wild collection or plant cultivation, the production of useful and valuable secondary metabolites in large bioreactors is an attractive proposal; it should contribute significantly to future attempts to preserve global biodiversity and alleviate associated ecological problems. The advantages of such processes include the controlled production according to demand and a reduced man work requirement. Plant cells have been grown in different shape bioreactors, however, there are a variety of problems to be solved before this technology can be adopted on a wide scale for the production of useful plant secondary metabolites. There are different factors affecting the culture growth and secondary metabolite production in bioreactors: the gaseous atmosphere, oxygen supply and CO2 exchange, pH, minerals, carbohydrates, growth regulators, the liquid medium rheology and cell density. Moreover agitation systems and sterilization conditions may negatively influence the whole process. Many types ofbioreactors have been successfully used for cultivating transformed root cultures, depending on both different aeration system and nutrient supply. Several examples of medicinal and aromatic plant cultures were here summarized for the scale up cultivation in bioreactors. PMID:21520713

Ruffoni, Barbara; Pistelli, Laura; Bertoli, Alessandra; Pistelli, Luisa

2010-01-01

311

Cultural Studies in the English Classroom.  

ERIC Educational Resources Information Center

This book opens up ways of teaching and devising programs which place the students' cultural experiences at the center of language production and consumption. It provides concrete models of cultural studies programs and classrooms for high school and college teachers who would like to try the "cultural studies approach." It also offers a…

Berlin, James A., Ed.; Vivion, Michael J., Ed.

312

Establishing a stem cell culture laboratory for clinical trials  

PubMed Central

Adult stem/progenitor cells are found in different human tissues. An in vitro cell culture is needed for their isolation or for their expansion when they are not available in a sufficient quantity to regenerate damaged organs and tissues. The level of complexity of these new technologies requires adequate facilities, qualified personnel with experience in cell culture techniques, assessment of quality and clear protocols for cell production. The rules for the implementation of cell therapy centers involve national and international standards of good manufacturing practices. However, such standards are not uniform, reflecting the diversity of technical and scientific development. Here standards from the United States, the European Union and Brazil are analyzed. Moreover, practical solutions encountered for the implementation of a cell therapy center appropriate for the preparation and supply of cultured cells for clinical studies are described. Development stages involved the planning and preparation of the project, the construction of the facility, standardization of laboratory procedures and development of systems to prevent cross contamination. Combining the theoretical knowledge of research centers involved in the study of cells with the practical experience of blood therapy services that manage structures for cell transplantation is presented as the best potential for synergy to meet the demands to implement cell therapy centers.

Sekiya, Eliseo Joji; Forte, Andresa; Kuhn, Telma Ingrid Borges de Bellis; Janz, Felipe; Bydlowski, Sergio Paulo; Alves, Adelson

2012-01-01

313

Calcium deposition in osteoarthritic meniscus and meniscal cell culture  

PubMed Central

Introduction Calcium crystals exist in the knee joint fluid of up to 65% of osteoarthritis (OA) patients and the presence of these calcium crystals correlates with the radiographic evidence of hyaline cartilaginous degeneration. This study sought to examine calcium deposition in OA meniscus and to investigate OA meniscal cell-mediated calcium deposition. The hypothesis was that OA meniscal cells may play a role in pathological meniscal calcification. Methods Studies were approved by our human subjects Institutional Review Board. Menisci were collected during joint replacement surgeries for OA patients and during limb amputation surgeries for osteosarcoma patients. Calcium deposits in menisci were examined by alizarin red staining. Expression of genes involved in biomineralization in OA meniscal cells was examined by microarray and real-time RT-PCR. Cell-mediated calcium deposition in monolayer culture of meniscal cells was examined using an ATP-induced 45calcium deposition assay. Results Calcium depositions were detected in OA menisci but not in normal menisci. The expression of several genes involved in biomineralization including ENPP1 and ANKH was upregulated in OA meniscal cells. Consistently, ATP-induced calcium deposition in the monolayer culture of OA meniscal cells was much higher than that in the monolayer culture of control meniscal cells. Conclusions Calcium deposition is common in OA menisci. OA meniscal cells calcify more readily than normal meniscal cells. Pathological meniscal calcification, which may alter the biomechanical properties of the knee meniscus, is potentially an important contributory factor to OA.

2010-01-01

314

Use of an adaptable cell culture kit for performing lymphocyte and monocyte cell cultures in microgravity  

NASA Technical Reports Server (NTRS)

The results of experiments performed in recent years on board facilities such as the Space Shuttle/Spacelab have demonstrated that many cell systems, ranging from simple bacteria to mammalian cells, are sensitive to the microgravity environment, suggesting gravity affects fundamental cellular processes. However, performing well-controlled experiments aboard spacecraft offers unique challenges to the cell biologist. Although systems such as the European 'Biorack' provide generic experiment facilities including an incubator, on-board 1-g reference centrifuge, and contained area for manipulations, the experimenter must still establish a system for performing cell culture experiments that is compatible with the constraints of spaceflight. Two different cell culture kits developed by the French Space Agency, CNES, were recently used to perform a series of experiments during four flights of the 'Biorack' facility aboard the Space Shuttle. The first unit, Generic Cell Activation Kit 1 (GCAK-1), contains six separate culture units per cassette, each consisting of a culture chamber, activator chamber, filtration system (permitting separation of cells from supernatant in-flight), injection port, and supernatant collection chamber. The second unit (GCAK-2) also contains six separate culture units, including a culture, activator, and fixation chambers. Both hardware units permit relatively complex cell culture manipulations without extensive use of spacecraft resources (crew time, volume, mass, power), or the need for excessive safety measures. Possible operations include stimulation of cultures with activators, separation of cells from supernatant, fixation/lysis, manipulation of radiolabelled reagents, and medium exchange. Investigations performed aboard the Space Shuttle in six different experiments used Jurkat, purified T-cells or U937 cells, the results of which are reported separately. We report here the behaviour of Jurkat and U937 cells in the GCAK hardware in ground-based investigations simulating the conditions expected in the flight experiment. Several parameters including cell concentration, time between cell loading and activation, and storage temperature on cell survival were examined to characterise cell response and optimise the experiments to be flown aboard the Space Shuttle. Results indicate that the objectives of the experiments could be met with delays up to 5 days between cell loading into the hardware and initial in flight experiment activation, without the need for medium exchange. Experiment hardware of this kind, which is adaptable to a wide range of cell types and can be easily interfaced to different spacecraft facilities, offers the possibility for a wide range of experimenters successfully and easily to utilise future flight opportunities.

Hatton, J. P.; Lewis, M. L.; Roquefeuil, S. B.; Chaput, D.; Cazenave, J. P.; Schmitt, D. A.

1998-01-01

315

Ten commandments for preventing contamination of primary cell cultures  

Microsoft Academic Search

Procedures for preventing contamination in primary cell cultures must be carefully defined and strictly followed in order to obtain healthy cells. Protocols have been developed and refined in our laboratory for establishing primary cultures of muscle and fat stem cells without contamination from a variety of animals. Contamination of cell cultures is not only frustrating, but is also very expensive

Janet L. Vierck; Katherine Byrne; Priya S. Mir; Michael V. Dodson

2000-01-01

316

Culture, Development, and Social Theory: On Cultural Studies and the Place of Culture in Development  

Microsoft Academic Search

Debates in development theory have recently swung back to taking seriously the relationship of culture to development, especially in the face of manifest failures of conventional approaches to economic growth and social transformation. This has happened at a moment when, especially within anthropology, the concept of culture itself is undergoing critical examination, and when cultural studies has emerged as a

John Clammer

2005-01-01

317

Cytotoxic activity of extracts from Linum cell cultures.  

PubMed

Callus and suspension cultures of Linum narbonense and Linum leonii were developed to study the production of lignans and their cytotoxic activity. Justicidin B was determined to be the main lignan. The maximal yield of justicidin B up to 2.22 mg/g of the cell dry weight was detected in the callus cultures of L. leonii, followed by the callus cultures of L. narbonense (1.57 mg/g dwt). The cytotoxicity of the obtained extracts was measured using the MTT-dye assay. L. narbonense and L. leonii both showed cytotoxic activity. PMID:15664462

Vasilev, N P; Ionkova, I

2005-01-01

318

Cultural studies of science education  

NASA Astrophysics Data System (ADS)

In response to Stetsenko's [2008, Cultural Studies of Science Education, 3] call for a more unified approach in sociocultural perspectives, this paper traces the origins of the use of sociocultural ideas in New Zealand from the 1970s to the present. Of those New Zealanders working from a sociocultural perspective who responded to our query most had encountered these ideas while overseas. More recently activity theory has been of interest and used in reports of work in early childhood, workplace change in the apple industry, and in-service teacher education. In all these projects the use of activity theory has been useful for understanding how the elements of a system can transform the activity. We end by agreeing with Stetsenko that there needs to be a more concerted approach by those working from a sociocultural perspective to recognise the contribution of others in the field.

Higgins, Joanna; McDonald, Geraldine

2008-07-01

319

Specimen Sample Preservation for Cell and Tissue Cultures  

NASA Technical Reports Server (NTRS)

The era of the International Space Station with its longer duration missions will pose unique challenges to microgravity life sciences research. The Space Station Biological Research Project (SSBRP) is responsible for addressing these challenges and defining the science requirements necessary to conduct life science research on-board the International Space Station. Space Station will support a wide range of cell and tissue culture experiments for durations of 1 to 30 days. Space Shuttle flights to bring experimental samples back to Earth for analyses will only occur every 90 days. Therefore, samples may have to be retained for periods up to 60 days. This presents a new challenge in fresh specimen sample storage for cell biology. Fresh specimen samples are defined as samples that are preserved by means other than fixation and cryopreservation. The challenge of long-term storage of fresh specimen samples includes the need to suspend or inhibit proliferation and metabolism pending return to Earth-based laboratories. With this challenge being unique to space research, there have not been any ground based studies performed to address this issue. It was decided hy SSBRP that experiment support studies to address the following issues were needed: Fixative Solution Management; Media Storage Conditions; Fresh Specimen Sample Storage of Mammalian Cell/Tissue Cultures; Fresh Specimen Sample Storage of Plant Cell/Tissue Cultures; Fresh Specimen Sample Storage of Aquatic Cell/Tissue Cultures; and Fresh Specimen Sample Storage of Microbial Cell/Tissue Cultures. The objective of these studies was to derive a set of conditions and recommendations that can be used in a long duration microgravity environment such as Space Station that will permit extended storage of cell and tissue culture specimens in a state consistent with zero or minimal growth, while at the same time maintaining their stability and viability.

Meeker, Gabrielle; Ronzana, Karolyn; Schibner, Karen; Evans, Robert

1996-01-01

320

Kinetics of Thallium Exchange in Cultured Rat Myocardial Cells  

Microsoft Academic Search

SUMMARY. The kinetics of thallium exchange in cultured rat myocardial cells were studied and compared to those of potassium in the same tissue. Studies were carried out using low concentra- tions (10 nM to 5 HM) of thallium-204, approximating those likely to be encountered during clinical myocardial scintigraphy. Both thallium uptake and release could be described by a single exponential

David McCall; Lawrence J. Zimmer; Arnold M. Katz

321

Region Specific Response of Intervertebral Disc Cells to Complex Dynamic Loading: An Organ Culture Study Using a Dynamic Torsion-Compression Bioreactor  

PubMed Central

The spine is routinely subjected to repetitive complex loading consisting of axial compression, torsion, flexion and extension. Mechanical loading is one of the important causes of spinal diseases, including disc herniation and disc degeneration. It is known that static and dynamic compression can lead to progressive disc degeneration, but little is known about the mechanobiology of the disc subjected to combined dynamic compression and torsion. Therefore, the purpose of this study was to compare the mechanobiology of the intervertebral disc when subjected to combined dynamic compression and axial torsion or pure dynamic compression or axial torsion using organ culture. We applied four different loading modalities [1. control: no loading (NL), 2. cyclic compression (CC), 3. cyclic torsion (CT), and 4. combined cyclic compression and torsion (CCT)] on bovine caudal disc explants using our custom made dynamic loading bioreactor for disc organ culture. Loads were applied for 8 h/day and continued for 14 days, all at a physiological magnitude and frequency. Our results provided strong evidence that complex loading induced a stronger degree of disc degeneration compared to one degree of freedom loading. In the CCT group, less than 10% nucleus pulposus (NP) cells survived the 14 days of loading, while cell viabilities were maintained above 70% in the NP of all the other three groups and in the annulus fibrosus (AF) of all the groups. Gene expression analysis revealed a strong up-regulation in matrix genes and matrix remodeling genes in the AF of the CCT group. Cell apoptotic activity and glycosaminoglycan content were also quantified but there were no statistically significant differences found. Cell morphology in the NP of the CCT was changed, as shown by histological evaluation. Our results stress the importance of complex loading on the initiation and progression of disc degeneration.

Chan, Samantha C. W.; Walser, Jochen; Kappeli, Patrick; Shamsollahi, Mohammad Javad; Ferguson, Stephen J.; Gantenbein-Ritter, Benjamin

2013-01-01

322

Plant cell cultures: Chemical factories of secondary metabolites  

Microsoft Academic Search

This review deals with the production of high-value secondary metabolites including pharmaceuticals and food additives through plant cell cultures, shoot cultures, root cultures and transgenic roots obtained through biotechnological means. Plant cell and transgenic hairy root cultures are promising potential alternative sources for the production of high-value secondary metabolites of industrial importance. Recent developments in transgenic research have opened up

S Ramachandra Rao; G. A Ravishankar

2002-01-01

323

Prolactin Supplementation to Culture Medium Improves Beta-Cell Survival  

PubMed Central

Objectives Recent studies demonstrated that prolactin has beneficial effects on ?-cells for islet transplantation. We examined the effect of human recombinant prolactin (rhPRL) supplementation to the culture media to determine its potential use in the context of clinical islet transplantation. Materials and Methods Each human islet isolated from 14 deceased multi-organ donors was cultured in Miami modified media-1 supplemented with or without rhPRL (500?g/L) for 48 hours. ?-cell survival and proliferation (BrdU and Ki-67) were determined by laser-scanning cytometry. The cytoprotective effects of rhPRL against noxious stimuli were assessed by flow cytometry (tetramethylrhodamine ethyl ester). Cytokine/chemokine and tissue factor (TF) production were measured in vitro and islet potency was assessed in vivo into diabetic immunodeficient mice. Results ?-cell survival during culture was 37% higher in the rhPRL group than in control (p=0.029). rhPRL protected ?-cells in vitro from cytokines, Nitric Oxide donor and H2O2. The exposure to rhPRL did not affect human beta-cell proliferation with our protocol. rhPRL treatment did not alter cytokine/chemokine and TF production in vitro nor affected human islet functionality in vivo: recipient mice achieved normoglycemia with a comparable tempo, while loss of graft function was observed in 2/7 mice in the control group and in none of the rhPRL group (p=n.s.). Conclusion rhPRL supplementation to islet culture media improved human ?-cell-specific survival without altering islet quality. Addition of rhPRL to cultured islets may grant a more viable ?-cell mass in culture. The development of ?-cell cytoprotective strategies will be of assistance in improving islet transplantation outcomes.

Yamamoto, Toshiyuki; Mita, Atsuyoshi; Ricordi, Camillo; Messinger, Shari; Miki, Atsushi; Sakuma, Yasunaru; Timoneri, Francesca; Barker, Scott; Fornoni, Alessia; Molano, R. Damaris; Inverardi, Luca; Pileggi, Antonello; Ichii, Hirohito

2013-01-01

324

Ontogeny of electrically excitable cells in cultured olfactory epithelium.  

PubMed Central

A primary system has been developed in which it is possible to study the production of electrically excitable neuron-like cells from a precursor population of olfactory epithelial cells. Rat nasal epithelium was dissociated and placed in culture. The initial surviving cells are flat and ciliated and contain glial fibrillary acidic protein (GFAP). After 3-5 days electrically excitable cells appear that contain neuron-specific enolase but not GFAP. These round cells originate by means of the differentiation of the GFAP-positive flat cell to a round cell, followed by the division of the round cell. Therefore, neuron-like cells can be derived from cells that synthesize GFAP. Images

Schubert, D; Stallcup, W; LaCorbiere, M; Kidokoro, Y; Orgel, L

1985-01-01

325

Cell volume and dry weight of cultured Tetrahymena.  

PubMed

Cultures of Tetrahymena pyriformis, T. hegewishi and T. malaccensis have been studied with regard to control of cell volume and cellular dry weight. Cell volume was measured on cells suspended in 0.9% sodium chloride + 0.1% sodium azide using a Multisizer cell counter (Coulter). Tetrahymena were grown at different temperatures and under various up- or downshift conditions. In all cases the changes in cell volume are paralleled by changes in cellular dry weight. The volume and the dry weight of a Tetrahymena cell are determined by the particular medium and the growth temperature. Large cells are seen in concentrated media and at low growth temperatures resulting in cell volumes up to 17,000 microns 3, whereas starving cells decrease gradually towards 700 microns 3 or even smaller sizes. It is proposed that lag phase observed at up- and downshift is to a large extent due to the necessary adjustment of the cell volume to the new conditions. PMID:2777928

Hellung-Larsen, P; Andersen, A P

1989-02-01

326

Smokeless tobacco extracts modulate exogenous gene expression in early passage cultured human oral epithelial cells: an in vitro system to study chemical and viral enhancer/promoter interaction.  

PubMed

The increased risk for cancers of the oral cavity from smokeless tobacco use may reflect the interaction of tobacco with genetic factors, such as oncogenes, and other exogenous factors, such as viruses. An in vitro system was developed based on expression of the chloramphenicol acetyltransferase (CAT) reporter gene to study interactions of chemical treatments with viral enhancer/promoters in early passage cell cultures of oral cavity-derived epithelial cells. Expression of CAT in transfected cells was significantly greater with CAT under the control of the cytomegalovirus immediate early enhancer/promoter (pCEP4/CAT) compared to the Rous sarcoma virus long terminal repeat enhancer/promoter (pRSV-cat) and the simian virus 40 (SV40) early promoter (pSV2-cat). No CAT expression was detected using corresponding control plasmids without the CAT reporter gene. Using this system, smokeless tobacco extracts prepared from either dry snuff or moist snuff delayed maximum CAT expression from Day 4 to Day 5, with sustained, significantly increased CAT expression at 12 days compared to the declining CAT expression observed in untreated control cells. Smokeless tobacco extracts can modulate intracellular gene expression. This system provides an in vitro model to test specificity of toxic agents on enhancer/promoter activity and the interaction on exogenous gene expression. PMID:11395331

Demirci, C S; Miller, D R; Baillargeon, J; Moyer, M P; Jenson, H B

2000-01-01

327

Aragonite precipitation by "proto-polyps" in coral cell cultures.  

PubMed

The mechanisms of coral calcification at the molecular, cellular and tissue levels are poorly understood. In this study, we examine calcium carbonate precipitation using novel coral tissue cultures that aggregate to form "proto-polyps". Our goal is to establish an experimental system in which calcification is facilitated at the cellular level, while simultaneously allowing in vitro manipulations of the calcifying fluid. This novel coral culturing technique enables us to study the mechanisms of biomineralization and their implications for geochemical proxies. Viable cell cultures of the hermatypic, zooxanthellate coral, Stylophora pistillata, have been maintained for 6 to 8 weeks. Using an enriched seawater medium with aragonite saturation state similar to open ocean surface waters (?(arag)~4), the primary cell cultures assemble into "proto-polyps" which form an extracellular organic matrix (ECM) and precipitate aragonite crystals. These extracellular aragonite crystals, about 10 µm in length, are formed on the external face of the proto-polyps and are identified by their distinctive elongated crystallography and X-ray diffraction pattern. The precipitation of aragonite is independent of photosynthesis by the zooxanthellae, and does not occur in control experiments lacking coral cells or when the coral cells are poisoned with sodium azide. Our results demonstrate that proto-polyps, aggregated from primary coral tissue culture, function (from a biomineralization perspective) similarly to whole corals. This approach provides a novel tool for investigating the biophysical mechanism of calcification in these organisms. PMID:22514707

Mass, Tali; Drake, Jeana L; Haramaty, Liti; Rosenthal, Yair; Schofield, Oscar M E; Sherrell, Robert M; Falkowski, Paul G

2012-01-01

328

Generation of a large volume of clinically relevant nanometre-sized ultra-high-molecular-weight polyethylene wear particles for cell culture studies.  

PubMed

It has recently been shown that the wear of ultra-high-molecular-weight polyethylene in hip and knee prostheses leads to the generation of nanometre-sized particles, in addition to micron-sized particles. The biological activity of nanometre-sized ultra-high-molecular-weight polyethylene wear particles has not, however, previously been studied due to difficulties in generating sufficient volumes of nanometre-sized ultra-high-molecular-weight polyethylene wear particles suitable for cell culture studies. In this study, wear simulation methods were investigated to generate a large volume of endotoxin-free clinically relevant nanometre-sized ultra-high-molecular-weight polyethylene wear particles. Both single-station and six-station multidirectional pin-on-plate wear simulators were used to generate ultra-high-molecular-weight polyethylene wear particles under sterile and non-sterile conditions. Microbial contamination and endotoxin levels in the lubricants were determined. The results indicated that microbial contamination was absent and endotoxin levels were low and within acceptable limits for the pharmaceutical industry, when a six-station pin-on-plate wear simulator was used to generate ultra-high-molecular-weight polyethylene wear particles in a non-sterile environment. Different pore-sized polycarbonate filters were investigated to isolate nanometre-sized ultra-high-molecular-weight polyethylene wear particles from the wear test lubricants. The use of the filter sequence of 10, 1, 0.1, 0.1 and 0.015 µm pore sizes allowed successful isolation of ultra-high-molecular-weight polyethylene wear particles with a size range of < 100 nm, which was suitable for cell culture studies. PMID:24658586

Liu, Aiqin; Ingham, Eileen; Fisher, John; Tipper, Joanne L

2014-04-01

329

Neonatal Rat Heart Cells Cultured in Simulated Microgravity.  

National Technical Information Service (NTIS)

In vitro characteristics of cardiac cells cultured in simulated microgravity are reported. Tissue culture methods performed at unit gravity constrain cells to propagate, differentiate, and interact in a two dimensional (2D) plane. Neonatal rat cardiac cel...

R. E. Akins N. A. Schroedl S. R. Gonda C. R. Hartzell

1994-01-01

330

Towards obtaining long term embryonic stem cell like cultures from a marine flatfish, Scophtalmus maximus  

Microsoft Academic Search

Culturing pluripotent embryonic stem cells represents a unique model system for in vitro studies of embryo cell growth and differentiation, and represents a connection between in vitro and in vivo manipulation of genes. To further develop and refine stem cell technology for marine fish, we have established cultures of\\u000a embryonic stem cells isolated from turbot blastulas. The pluripotent nature of

E. Holen; K. Hamre

2003-01-01

331

Nanopillar based electrochemical biosensor for monitoring microfluidic based cell culture  

NASA Astrophysics Data System (ADS)

In-vitro assays using cultured cells have been widely performed for studying many aspects of cell biology and cell physiology. These assays also form the basis of cell based sensing. Presently, analysis procedures on cell cultures are done using techniques that are not integrated with the cell culture system. This approach makes continuous and real-time in-vitro measurements difficult. It is well known that the availability of continuous online measurements for extended periods of time will help provide a better understanding and will give better insight into cell physiological events. With this motivation we developed a highly sensitive, selective and stable microfluidic electrochemical glucose biosensor to make continuous glucose measurements in cell culture media. The performance of the microfluidic biosensor was enhanced by adding 3D nanopillars to the electrode surfaces. The microfluidic glucose biosensor consisted of three electrodes---Enzyme electrode, Working electrode, and Counter electrode. All these electrodes were enhanced with nanopillars and were optimized in their respective own ways to obtain an effective and stable biosensing device in cell culture media. For example, the 'Enzyme electrode' was optimized for enzyme immobilization via either a polypyrrole-based or a self-assembled-monolayer-based immobilization method, and the 'Working electrode' was modified with Prussian Blue or electropolymerized Neutral Red to reduce the working potential and also the interference from other interacting electro-active species. The complete microfluidic biosensor was tested for its ability to monitor glucose concentration changes in cell culture media. The significance of this work is multifold. First, the developed device may find applications in continuous and real-time measurements of glucose concentrations in in-vitro cell cultures. Second, the development of a microfluidic biosensor will bring technical know-how toward constructing continuous glucose monitoring devices. Third, the methods used to develop 3D electrodes incorporated with nanopillars can be used for other applications such as neural probes, fuel cells, solar cells etc., and finally, the knowledge obtained from the immobilization of enzymes onto nanostructures sheds some new insight into nanomaterial/biomolecule interactions.

Gangadharan, Rajan

332

Immortalized porcine intestinal epithelial cell cultures susceptible to porcine rotavirus infection.  

PubMed

In vitro studies related to various viral pathogenesis in swine have been hampered by the lack of relevant porcine cell lines. The susceptibility to porcine rotavirus infection was evaluated by using a newly established porcine intestinal epithelial cell line. Immunohistochemical staining for cytokeratin confirmed that the cultured cells were epithelial cells. Measurement of cell viability and detection of infected cells confirmed that these epithelial cells were susceptible to porcine rotavirus infection. This study describes the cytopathic changes in cultured porcine intestinal epithelial cells during virus invasion. Following infection with porcine rotavirus, the cell cultures contained viral protein at 16h post-infection as detected by direct immunofluorescence. The epithelial cell cultures provided competent target cells for studying host cell responses to porcine rotavirus and a homologous system for investigating the response of intestinal epithelial cells during viral infection. PMID:24642240

Wang, Jing; Hu, Guangdong; Gao, Wanjun; Xu, Lei; Ning, Pengbo; Zhang, Yanming

2014-06-15

333

Insulin receptors in cultured mouse retinal cells  

Microsoft Academic Search

Summary  The binding of125I-insulin to uncloned and cloned cultures of mouse retinal cells has been investigated. At 15° C, binding of the hormone reached a steady state by 60 min, while at 37° C equilibrium was reached earlier but at a lower level than at 15° C. Porcine insulin, porcine proinsulin and guinea pig insulin displaced labelled insulin in proportion to

P. Thomopoulos; B. Pessac

1979-01-01

334

Natural products from plant cell cultures  

Microsoft Academic Search

Plants produce complex small molecules — natural products — that exhibit anticancer, antimalarial and antimicrobial activity.\\u000a These molecules play a key role in human medicine. However, plants typically produce these compounds in low quantities, and\\u000a harvesting plant natural products is frequently expensive, time-consuming and environmentally damaging. Plant cell culture\\u000a provides a renewable, easily scalable source of plant material. In this

Elizabeth McCoy; Sarah E. O’Connor

335

Detection of anaerobic mycoplasmas in cell cultures  

Microsoft Academic Search

Summary  A commercially available anaerobic generator and incubation system that develops a low oxidation-reduction potential was used\\u000a for the assay of cell cultures for mycoplasmal contamination. Mycoplasma broth and agar media supplemented with dextrose,\\u000a yeast extract, and horse serum were used. This system supported growth of some mycoplasmas that failed to grow in incubators\\u000a with 5% CO2 in nitrogen previously used

Gerard J. McGarrity; Lewis L. Coriell

1973-01-01

336

Convenient three-dimensional cell culture in supermolecular hydrogels.  

PubMed

A convenient three-dimensional cell culture was developed by employing high swelling property of hybrid hydrogels coassembled from C2-phenyl-based supermolecular gelators and sodium hyaluronate. Imaging and spectroscopic analysis by scanning electron microscopy (SEM), atomic force microscopy (AFM), transform infrared (FT-IR) spectra confirm that the hybrid gelators can self-assemble into nanofibrous hydrogel. The high swelling property of dried gel ensures cell migration and proliferation inside bulk of the hydrogels, which provides a facial method to study disease models, the effect of drug dosages, and tissue culture in vitro. PMID:24802591

Li, Ping; Yin, Zongqi; Dou, Xiao-Qiu; Zhou, Guangdong; Feng, Chuan-Liang

2014-05-28

337

The effect of the controlled release of nerve growth factor from collagen gel on the efficiency of neural cell culture  

Microsoft Academic Search

In this study, we tested the hypothesis that the amount of nerve growth factor (NGF) required for pheochromocytoma (PC12) cell culture can be dramatically reduced by controlled release of NGF from a collagen gel coating on the culture surface. Cells were cultured on collagen gels loaded with various amounts of NGF. As a control, PC12 cells were cultured on collagen

Suk Ho Bhang; Tae-Jin Lee; Jae Min Lim; Jung Su Lim; Ah Mi Han; Cha Yong Choi; Yun Hee Kim Kwon; Byung-Soo Kim

2009-01-01

338

Recombinant protein production and insect cell culture and process  

NASA Technical Reports Server (NTRS)

A process has been developed for recombinant production of selected polypeptides using transformed insect cells cultured in a horizontally rotating culture vessel modulated to create low shear conditions. A metabolically transformed insect cell line is produced using the culture procedure regardless of genetic transformation. The recombinant polypeptide can be produced by an alternative process using the cultured insect cells as host for a virus encoding the described polypeptide such as baculovirus. The insect cells can also be a host for viral production.

Spaulding, Glenn (inventor); Prewett, Tacey (inventor); Goodwin, Thomas (inventor); Francis, Karen (inventor); Andrews, Angela (inventor); Oconnor, Kim (inventor)

1993-01-01

339

Regulation of expression of glucose transporters by glucose: a review of studies in vivo and in cell cultures  

Microsoft Academic Search

Glucose transporters are membrane- embedded proteins that mediate the uptake of glucose from the surrounding medium into the cell. Glucose is the main fuel for most cells, and its uptake is rate-limiting for glucose utilization. For this reason, it is expected that glu- cose transport is tightly regulated. Whereas rapid regula- tion of glucose transporters by hormones has been known

AMIRA KLIP; THEODOROS TSAKIRIDIS; S ANDRE MARETTE; PHILLIP A. ORTIZ

340

Extracellular matrix and culture substratum effects on trace metal content of epithelial cancer cells  

NASA Astrophysics Data System (ADS)

The effect of extracellular adhesion factors, and of distinct culture substrata, on trace element content of epithelial cancer cells was investigated using nuclear microprobe analysis. Essential trace metal concentrations in human carcinoma cells cultured either onto tissue culture plastic dishes, onto microanalysis supports made of thin Formvar surfaces coated or not with gelatin gel, or onto polycarbonate films, were compared. Abnormally high copper concentrations were noticed specifically in cisplatin-resistant epithelial cancer cells cultured onto Formvar or polycarbonate surfaces with or without reconstituted extracellular matrix. Manganese, iron and zinc concentrations remained unchanged in these cells. These results indicate that (1) metal uptake of cells cultured onto substrata used for X-ray microanalysis can be different to that of cells cultured onto usual plastic dishes, (2) cisplatin-resistant epithelial cancer cells specifically accumulate copper when cultured onto thin Formvar or polycarbonate films, and could be used as in vitro models for copper overload studies.

Ortega, R.; Gonçalves, P.; Llabador, Y.; Simonoff, M.

1999-10-01

341

Scaffold-free culture of mesenchymal stem cell spheroids in suspension preserves multilineage potential  

Microsoft Academic Search

While traditional cell culture methods have relied on growing cells as monolayers, three-dimensional (3D) culture systems\\u000a can provide a convenient in vitro model for the study of complex cell–cell and cell–matrix interactions in the absence of\\u000a exogenous substrates and may benefit the development of regenerative medicine strategies. In this study, mesenchymal stem\\u000a cell (MSC) spheroids, or “mesenspheres”, of different sizes,

Priya R. Baraniak; Todd C. McDevitt

342

Gymnemic Acid Production in Suspension Cell Cultures of Gymnema sylvestre  

Microsoft Academic Search

Use of Gymnema sylvestre, commonly known as Periploca of woods an Indian medicinal woody climber has increased recently due to the pharmaceutical potential of gymnemic acids, found in its leaves. Gymnemic acids has been reported to effect a natural treatment for diabetes. This study developed a novel cell culture system for in vitro growth and production of this species, suggesting

C. Subathra Devi; S. Murugesh; V. Mohana Srinivasan

2006-01-01

343

Isolation and Culture of Pulmonary Endothelial Cells from Neonatal Mice  

PubMed Central

Endothelial cells provide a useful research model in many areas of vascular biology. Since its first isolation 1, human umbilical vein endothelial cells (HUVECs) have shown to be convenient, easy to obtain and culture, and thus are the most widely studied endothelial cells. However, for research focused on processes like angiogenesis, permeability or many others, microvascular endothelial cells (ECs) are a much more physiologically relevant model to study 2. Furthermore, ECs isolated from knockout mice provide a useful tool for analysis of protein function ex vivo. Several approaches to isolate and culture microvascular ECs of different origin have been reported to date 3-7, but consistent isolation and culture of pure ECs is still a major technical problem in many laboratories. Here, we provide a step-by-step protocol on a reliable and relatively simple method of isolating and culturing mouse lung endothelial cells (MLECs). In this approach, lung tissue obtained from 6- to 8-day old pups is first cut into pieces, digested with collagenase/dispase (C/D) solution and dispersed mechanically into single-cell suspension. MLECS are purified from cell suspension using positive selection with anti-PECAM-1 antibody conjugated to Dynabeads using a Magnetic Particle Concentrator (MPC). Such purified cells are cultured on gelatin-coated tissue culture (TC) dishes until they become confluent. At that point, cells are further purified using Dynabeads coupled to anti-ICAM-2 antibody. MLECs obtained with this protocol exhibit a cobblestone phenotype, as visualized by phase-contrast light microscopy, and their endothelial phenotype has been confirmed using FACS analysis with anti-VE-cadherin 8 and anti-VEGFR2 9 antibodies and immunofluorescent staining of VE-cadherin. In our hands, this two-step isolation procedure consistently and reliably yields a pure population of MLECs, which can be further cultured. This method will enable researchers to take advantage of the growing number of knockout and transgenic mice to directly correlate in vivo studies with results of in vitro experiments performed on isolated MLECs and thus help to reveal molecular mechanisms of vascular phenotypes observed in vivo.

Sobczak, Magdalena; Dargatz, Jillian; Chrzanowska-Wodnicka, Magdalena

2010-01-01

344

Culturing conditions affecting the production of anthocyanin in suspended cell cultures of strawberry  

Microsoft Academic Search

The increase of anthocyanin content in suspended cell cultures of strawberry varied with the increase in the amount of pigmentation in pigmented cells and in number of pigmented cells in a culture. The anthocyanin yield was enhanced by increasing light irradiation, and this may have resulted from increased accumulation of anthocyanin in pigmented cells. The increased anthocyanin yield for the

Kenji Sato; Mamoru Nakayama; Jun-ichi Shigeta

1996-01-01

345

Targeting regulatory T cells in cytokine-induced killer cell cultures (Review)  

PubMed Central

Regulatory T cells (Tregs) are potent immunosuppressive cells that promote tumor growth and invasion by inducing immune escape and suppressing the antitumor immune response. Cytokine-induced killer (CIK) cells are considered to be the primary candidate for adoptive immunotherapy due to their strong antitumor activity. It was recently reported that the concomitant presence of Tregs may decrease the cytotoxicity of CIK cells. Therefore, depletion or downregulation of Tregs in CIK cell cultures by optimizing the culture program may enhance CIK cell cytotoxicity in vitro and in vivo. The aim of the present review was to summarize the currently available studies on the optimal culture strategy for improving the antitumor activity of CIK cells through targeting Tregs.

TAO, QIANSHAN; WANG, HUIPING; ZHAI, ZHIMIN

2014-01-01

346

Three-Dimensional Cultures of Mouse Mammary Epithelial Cells  

PubMed Central

The mammary gland is an ideal “model organism” for studying tissue specificity and gene expression in mammals: it is one of the few organs that develop after birth and it undergoes multiple cycles of growth, differentiation and regression during the animal’s lifetime in preparation for the important function of lactation. The basic “functional differentiation” unit in the gland is the mammary acinus made up of a layer of polarized epithelial cells specialized for milk production surrounded by myoepithelial contractile cells, and the two-layered structure is surrounded by basement membrane. Much knowledge about the regulation of mammary gland development has been acquired from studying the physiology of the gland and of lactation in rodents. Culture studies, however, were hampered by the inability to maintain functional differentiation on conventional tissue culture plastic. We now know that the microenvironment, including the extracellular matrix and tissue architecture, plays a crucial role in directing functional differentiation of organs. Thus, in order for culture systems to be effective experimental models, they need to recapitulate the basic unit of differentiated function in the tissue or organ and to maintain its three-dimensional (3D) structure. Mouse mammary culture models evolved from basic monolayers of cells to an array of complex 3D systems that observe the importance of the microenvironment in dictating proper tissue function and structure. In this chapter, we focus on how 3D mouse mammary epithelial cultures have enabled investigators to gain a better understanding of the organization, development and function of the acinus, and to identify key molecular, structural, and mechanical cues important for maintaining mammary function and architecture. The accompanying chapter of Vidi et al. describes 3D models developed for human cells. Here, we describe how mouse primary epithelial cells and cell lines—essentially those we use in our laboratory—are cultured in relevant 3D microenvironments. We focus on the design of functional assays that enable us to understand the intricate signaling events underlying mammary gland biology, and address the advantages and limitations of the different culture settings. Finally we also discuss how advances in bioengineering tools may help towards the ultimate goal of building tissues and organs in culture for basic research and clinical studies.

Mroue, Rana; Bissell, Mina J.

2013-01-01

347

Artifacts in Cell Culture: Rapid Generation of Hydrogen Peroxide on Addition of (?)-Epigallocatechin, (?)-Epigallocatechin Gallate, (+)Catechin, and Quercetin to Commonly Used Cell Culture Media  

Microsoft Academic Search

There is considerable current interest in the possible beneficial health effects of quercetin, catechins, epigallocatechins, epigallocatechin gallates, and related phenolic compounds found in teas, wines, and other plant products. As a result, many laboratories are studying the effects of these compounds on cells in culture. The present paper shows that addition of these compounds to commonly used cell culture media

Lee Hua Long; Marie Veronique Clement; Barry Halliwell

2000-01-01

348

Arabinogalactan proteins are involved in cell aggregation of cell suspension cultures of Beta vulgaris L  

Microsoft Academic Search

Arabinogalactan proteins (AGPs) are glycoproteins present at cell surfaces. Although exact functions of AGPs remain elusive,\\u000a they are implicated in plant growth and development. The aim of this study was to evaluate the role of AGPs in the process\\u000a of cell aggregation of Beta vulgaris L. suspension cultures. It was observed that B. vulgaris suspension cultures accumulated AGPs in parallel

Jacqueline Capataz-Tafur; Gabriela Trejo-Tapia; Mario Rodríguez-Monroy; Gabriela Sepúlveda-Jiménez

2011-01-01

349

Vibrational spectroscopy characterization of low level laser therapy on mammary culture cells: a micro-FTIR study  

NASA Astrophysics Data System (ADS)

Low level laser therapy (LLLT) is an emerging therapeutic approach for several clinical conditions. The clinical effects induced by LLLT presumably go from the photobiostimulation/photobioinibition at cellular level to the molecular level. The detailed mechanism underlying this effect is still obscure. This work is dedicated to quantify some relevant aspects of LLLT related to molecular and cellular variations. This goal was attached by exposing malignant breast cells (MCF7) to spatially filtered light of a He-Ne laser (633 nm) with 28.8 mJ/cm2 of fluency. The cell viability was evaluated by microscopic observation using Trypan Blue viability test. The vibrational spectra of each experimental group (micro- FTIR technique) were used to identify the relevant biochemical alterations occurred due the process. The red light had influence over RNA, phosphate and serine/threonine/tyrosine bands. Light effects on cell number or viability were not detected. However, the irradiation had direct influence on metabolic activity of cells.

Magrini, Taciana D.; Villa Dos Santos, Nathalia; Pecora Milazzotto, Marcella; Cerchiaro, Giselle; da Silva Martinho, Herculano

2011-02-01

350

Darwinian evolution of prions in cell culture.  

PubMed

Prions are infectious proteins consisting mainly of PrP(Sc), a beta sheet-rich conformer of the normal host protein PrP(C), and occur in different strains. Strain identity is thought to be encoded by PrP(Sc) conformation. We found that biologically cloned prion populations gradually became heterogeneous by accumulating "mutants," and selective pressures resulted in the emergence of different mutants as major constituents of the evolving population. Thus, when transferred from brain to cultured cells, "cell-adapted" prions outcompeted their "brain-adapted" counterparts, and the opposite occurred when prions were returned from cells to brain. Similarly, the inhibitor swainsonine selected for a resistant substrain, whereas, in its absence, the susceptible substrain outgrew its resistant counterpart. Prions, albeit devoid of a nucleic acid genome, are thus subject to mutation and selective amplification. PMID:20044542

Li, Jiali; Browning, Shawn; Mahal, Sukhvir P; Oelschlegel, Anja M; Weissmann, Charles

2010-02-12

351

Fetal rabbit gastric epithelial cells cultured on floating collagen gels.  

PubMed

Cells were isolated from approximately 30 d fetal rabbit stomachs and cultured on floating collagen gels. Electron microscopy showed monolayers in which only one cell type persisted. These columnar cells were joined at apical borders by tight junctions and contained an extensive endoplasmic reticular network with an occasional intracellular canaliculus. They also occasionally contained what appeared to be secretory granules (mucus?), and therefore had some characteristics of all the cell types of the intact fetal stomachs, which showed oxyntic, mucous, and undifferentiated cells. In Ussing chambers with Ringer's solution on both sides, cultures developed transepithelial potential (potential difference [PD], mV, mucosa ground) = 13, resistance (resistance [R], omega - cm2) - 285, and short-circuit current (Isc, microA/cm3) = 45 (n = 7), clearly indicating that cellular polarity and junctional integrity were maintained. These transport parameters were somewhat different for intact fetal stomachs (PD = 20, R = 70, and Isc = 220 [n = 4]), which may be due to extensive folding of intact fetal stomachs or the presence of only one cell type in culture, or both. Although gastric stimulants histamine, dibutyryl cycle AMP (dbcAMP), and isobutylmethylxanthine (IMX) (a phosphodiesterase inhibitor) did not elicit H+ secretion or electrophysiological changes in monolayers or intact stomachs, 10-4 M apical amiloride caused a decrease in Isc in cultured monolayers(27%) and intact stomachs (50%). Thus, Na+ transport seems to be a significant fraction of ion transport in both preparations. This culture system may allow the study of oxyntic cell differentiation and the development of H+, Na+, and Cl- transport in the gastric musoca. PMID:7129478

Logsdon, C D; Bisbee, C A; Rutten, M J; Machen, T E

1982-03-01

352

Reactivation of persistent Chlamydia trachomatis infection in cell culture.  

PubMed Central

Gamma interferon induces persistent chlamydial infections in cell culture. These infections are characterized by altered morphologic and biochemical features of the pathogen. These persistent forms are abnormally large and noninfectious and undergo unusual structural and functional changes, including production of a paucity of outer envelope constituents and normal levels of the chlamydial hsp60, an immunopathological antigen. The current investigation evaluates the events that occur during reactivation of infectious Chlamydia trachomatis from persistently infected cell cultures. Transfer of persistent chlamydial organisms to gamma interferon-free medium resulted in recovery of infectivity accompanied by an increase in levels of structural membrane proteins and reorganization of aberrant organisms to morphologically typical elementary bodies. In addition, reactivation of infectious organisms from persistent chlamydiae that were maintained in culture for several weeks was demonstrated. These studies show that persistent C. trachomatis maintains viability for extended periods, illustrate the reversibility of immunologically mediated persistent infections, and characterize reactivation at the ultrastructural and biochemical levels.

Beatty, W L; Morrison, R P; Byrne, G I

1995-01-01

353

Heritability and Control of Differentiated Function in Cultured Cells  

PubMed Central

An established tissue culture cell line which retains a differentiated function in vitro is described. The cell line is of connective tissue origin, and its characteristic property is the synthesis and secretion of acid mucopolysaccharides, mainly hyaluronic acid. This differentiated cell function, the activity of which depends on continuous gene action, was found to be possessed by each of eleven clonal substrains, and is therefore a genetically heritable cell character. Rate of acid mucopolysaccharide biosynthesis falls sharply under the influence of the environmental conditions existing in crowded cultures, and this rate also declines if protein synthesis is directly inhibited with puromycin. Environmental modification of a differentiated product of gene action is thus illustrated in this study.

Davidson, E. H.

1963-01-01

354

Arraying cell cultures using PEG-DMA micromolding in standard culture dishes.  

PubMed

A robust and effortless procedure is presented, which allows for the microstructuring of standard cell culture dishes. Cell adhesion and proliferation are controlled by three-dimensional poly(ethylene glycol)-dimethacrylate (PEG-DMA) microstructures. The spacing between microwells can be extended to millimeter size in order to enable the combination with robotic workstations. Cell arrays of microcolonies can be studied under boundary-free growth conditions by lift-off of the PEG-DMA layer in which the growth rate is accessible via the evolution of patch areas. Alternatively, PEG-DMA stencils can be used as templates for plasma-induced patterning. PMID:23460347

Marel, Anna-Kristina; Rappl, Susanne; Piera Alberola, Alicia; Rädler, Joachim Oskar

2013-05-01

355

Migratory Behavior of Cells Generated in Ganglionic Eminence Cultures  

PubMed Central

Migration of cells is a common process that leads to the development and maturation of the vertebrate central nervous system (Hatten, '99). The cerebral cortex consists of two basic neuronal types: excitatory and inhibitory. These cells arise in distinct areas and migrate into the cortex along different routes (Pearlman et al., '98). Inhibitory interneurons migrate tangentially from subcortical sources, mostly from different regions of the ganglionic eminences (Gelman et al., '09; Xu et al., '04). Their movement requires precise spatiotemporal control imposed by environmental cues, to allow for the establishment of proper cytoarchitecture and connectivity in the cerebral cortex (Caviness & Rakic, '78; Hatten, '90; Rakic, '90). To study the migratory behavior of cells generated in proliferative zones of the ganglionic eminences (GE) in newborn ferrets in vitro we used a 3 dimensional culture arrangement in a BD Matrigel Matrix. The culture setup consisted of two GE explants and a source of tested proteins extracted from the cerebral cortex and adsorbed on fluorescent latex Retrobeads IX positioned between the explants (Hasling et al., '03; Riddle et al., '97). After 2-3 days of culture, the cells start to appear at the edge of the explant showing a propensity to leave the tissue in a radial direction. Live imaging allowed observation of migratory patterns without the necessity of labeling or marking the cells. When exposed to fractions of the protein extract obtained from isochronic ferret cortex, the GE cells displayed different behaviors as judged by quantitative kinetic analysis of individual moving cells.

Abbah, Joseph; Juliano, Sharon L.

2011-01-01

356

Microfabricated polyester conical microwells for cell culture applications.  

PubMed

Over the past few years there has been a great deal of interest in reducing experimental systems to a lab-on-a-chip scale. There has been particular interest in conducting high-throughput screening studies using microscale devices, for example in stem cell research. Microwells have emerged as the structure of choice for such tests. Most manufacturing approaches for microwell fabrication are based on photolithography, soft lithography, and etching. However, some of these approaches require extensive equipment, lengthy fabrication process, and modifications to the existing microwell patterns are costly. Here we show a convenient, fast, and low-cost method for fabricating microwells for cell culture applications by laser ablation of a polyester film coated with silicone glue. Microwell diameter was controlled by adjusting the laser power and speed, and the well depth by stacking several layers of film. By using this setup, a device containing hundreds of microwells can be fabricated in a few minutes to analyze cell behavior. Murine embryonic stem cells and human hepatoblastoma cells were seeded in polyester microwells of different sizes and showed that after 9 days in culture cell aggregates were formed without a noticeable deleterious effect of the polyester film and glue. These results show that the polyester microwell platform may be useful for cell culture applications. The ease of fabrication adds to the appeal of this device as minimal technological skill and equipment is required. PMID:21614380

Selimovi?, Seila; Piraino, Francesco; Bae, Hojae; Rasponi, Marco; Redaelli, Alberto; Khademhosseini, Ali

2011-07-21

357

Initiation and growth characterization of some hop cell suspension cultures  

Microsoft Academic Search

Cell suspension cultures of some hop (Humulus lupulus L.) cultivars were initiated from corresponding callus cultures induced on different media. Dissimilation curves were determined to characterize the growth of the suspension cultures maintained in Gamborg's B5 and in Murashige and Skoog's medium. Both media proved to be suitable; a comparison of the curves obtained for suspension cultures of the hop

Carlos R. Langezaal; Johannes J. C. Scheffer

1992-01-01

358

Amino Acid Transport into Cultured Tobacco Cells  

PubMed Central

The effects of calcium ions on lysine transport into cultured Wisconsin-38 tobacco cells were examined. In the presence of calcium, lysine was transported at a relatively low rate for 30 to 40 minutes followed by a period of increasing rates and subsequent stabilization at a higher rate after 2 to 3 hours. In the absence of calcium, transport was uniformly low. Time-dependent stimulation of lysine transport rate was observed after the cells had been preincubated in calcium-containing media. Similar treatments also resulted in the stimulated uptake of a variety of other amino acids, organic compounds, and sulfate. The stimulation of lysine uptake was apparently not due to nutrient starvation. Lysine transport was not stimulated in a time-dependent fashion by K+, La3+, Mg2+, or Mn2+. Cells with stimulated transport rates continued to exhibit high rates when washed with calcium-containing media followed by transport in calcium-containing media. All other cation wash treatments were inhibitory, although magnesium treatments resulted in partial preservation of stimulated transport rates. Cycloheximide inhibited the calcium/time-dependent stimulation of lysine transport and caused the stimulated rate to decay. The initial experimental treatments or the culture conditions may represent some form of shock that alters the membrane transport mechanism, thus reducing transport. The observed calcium/time-dependent stimulation may require protein synthesis and represents damage repair.

Harrington, H. Michael; Berry, Sandra L.; Henke, Randolph R.

1981-01-01

359

Propagation of human embryonic and induced pluripotent stem cells in an indirect co-culture system  

PubMed Central

We have developed and validated a microporous poly(ethylene terephthalate) membrane-based indirect co-culture system for human pluripotent stem cell (hPSC) propagation, which allows real-time conditioning of the culture medium with human fibroblasts while maintaining the complete separation of the two cell types. The propagation and pluripotent characteristics of a human embryonic stem cell (hESC) line and a human induced pluripotent stem cell (hiPSC) line were studied in prolonged culture in this system. We report that hPSCs cultured on membranes by indirect co-culture with fibroblasts were indistinguishable by multiple criteria from hPSCs cultured directly on a fibroblast feeder layer. Thus this co-culture system is a significant advance in hPSC culture methods, providing a facile stem cell expansion system with continuous medium conditioning while preventing mixing of hPSCs and feeder cells. This membrane culture method will enable testing of novel feeder cells and differentiation studies using co-culture with other cell types, and will simplify stepwise changes in culture conditions for staged differentiation protocols.

Abraham, Sheena; Sheridan, Steven D.; Laurent, Louise C.; Albert, Kelsey; Stubban, Christopher; Ulitsky, Igor; Miller, Bradley; Loring, Jeanne F.; Rao, Raj R.

2010-01-01

360

Basal cells are the progenitors of primary tracheal epithelial cell cultures  

SciTech Connect

The goal of this study was to identify the cells from the rat tracheal epithelium which attach and proliferate in primary culture. When cells isolated from tracheas by enzymatic digestion were held in suspension at 37C for several hours most of the differentiated cells dies. The kinetics of this selective cell death were not dependent on the constituents of the holding medium. With time in suspension, the colony forming efficiency of the surviving cells increased two- to threefold. Comparison of the growth curves of cells held or plated directly showed no difference in the number of cells in the proliferating populations. Using two lectins, it was possible to monitor the loss of specific populations in suspension. BS1-B4 is a marker for basal cells and UEA-1 is a secretory cell marker. Only those cells that were BS1-B4 positive survived in suspension. Further, the colonies that formed in primary culture were positive for this marker. Single cell suspensions of cells were sorted by flow cytometry and a fivefold increase in the colony forming efficiency of BS1-B4 positive cells compared to that of the negative cells was observed. These findings suggest that the cells that survived in suspension and proliferated in culture originated from the basal cells of the trachea.

Ford, J.R.; Terzaghi-Howe, M. (Univ. of Tennessee, Oak Ridge (United States) Oak Ridge National Lab., TN (United States))

1992-01-01

361

Isolation and cell culture propagation of rotaviruses from turkeys and chickens  

Microsoft Academic Search

Summary Rotaviruses were detected by electron microscopy in the faeces of turkey poults and broiler chickens with diarrhoea. Apparently symptomless infection was also observed in broilers. The avian rotaviruses could not be isolated in cell cultures by conventional techniques, but were adapted to serial growth in chick cell cultures following trypsin treatment of the virus and the cells. Immunofluorescence studies

M. S. McNulty; G. M. Allan; D. Todd; J. B. McFerran

1979-01-01

362

Ca2+ homeostasis in Brody's disease. A study in skeletal muscle and cultured muscle cells and the effects of dantrolene an verapamil.  

PubMed Central

Brody's disease, i.e., sarcoplasmic reticulum (SR) Ca(2+)-dependent Mg(2+)-ATPase (Ca(2+)-ATPase) deficiency, is a rare inherited disorder of skeletal muscle function. Pseudo-myotonia is the most important clinical feature. SR Ca(2+)-ATPase and Ca2+ homeostasis are examined in m. quadriceps and/or cultured muscle cells of controls and 10 patients suffering from Brody's disease. In both m. quadriceps and cultured muscle cells of patients, the SR Ca(2+)-ATPase activity is decreased by approximately 50%. However, the concentration of SR Ca(2+)-ATPase and SERCA1 are normal. SERCA1 accounts for 83 and 100% of total SR Ca(2+)-ATPase in m. quadriceps and cultured muscle cells, respectively. This implies a reduction of the molecular activity of SERCA1 in Brody's disease. The cytosolic Ca2+ concentration ([Ca2+]i) at rest and the increase of [Ca2+]i after addition of acetylcholine are the same in cultured muscle cells of controls and patients. The half-life of the maximal response, however, is raised three times in the pathological muscle cells. Addition of dantrolene or verapamil after the maximal response accelerates the restoration of the [Ca2+]i in these muscle cells. The differences in Ca2+ handling disappear by administration of dantrolene or verapamil concomitantly with acetylcholine. The reduced Ca2+ re-uptake from the cytosol presumably due to structural modification(s) of SERCA1 may explain the pseudo-myotonia in Brody's disease. Single cell measurements suggest a beneficial effect of dantrolene or verapamil in treating patients suffering from Brody's disease. Images

Benders, A A; Veerkamp, J H; Oosterhof, A; Jongen, P J; Bindels, R J; Smit, L M; Busch, H F; Wevers, R A

1994-01-01

363

Substrate Properties Influence Calcification in Valvular Interstitial Cell Culture  

PubMed Central

Background and aim of the study Valvular calcification is an active, cell-mediated process and results in significant morbidity and mortality. In standard culture, valvular interstitial cells (VICs) elicit significant calcification as a result of myofibroblast activation, and this limits the utility of these models to characterize VICs. In the work presented herein, we sought to investigate culturing substrates that suppress atypical VIC calcification and investigate culture substrates that represent a more physiological system. Methods Several culture platforms were selected to compare and contrast the influence of biochemical and mechanical properties on VIC calcification. Substrates investigated include: tissue culture polystyrene (TCPS), TCPS coated with either fibronectin or fibrin, and an elastic poly (ethylene glycol) (PEG) hydrogel with the same proteins coupled to the surface. Experiments were repeated with pro-fibrotic growth factor transforming growth factor- beta 1 (TGF-?1). VIC calcification was characterized by calcific nodule formation, alkaline phosphatase activity, and calcium accumulation. Gene and protein expression of alpha smooth muscle actin (?SMA) and core binding factor-1 (CBFa-1) were analyzed with qRT-PCR and immunostaining. Results Unmodified TCPS substrates had an innate ability to promote the markers of calcification studied. The addition of TGF-?1 enhanced all the levels of all osteoblastic markers studied. When TCPS surfaces were modified with fibronectin, all markers for calcification were repressed. However ?SMA, a marker for myofibroblastic activity, was unchanged. Meanwhile fibrin modified TCPS surfaces enhanced calcification over unmodified TCPS substrates. On the soft PEG hydrogels, all markers for calcification were repressed regardless of the surface chemistry, while ?SMA expression remained unaffected. Conclusions Collectively, VIC properties are highly linked to the culture microenvironment. Both the biochemical and mechanical environment of tissue culture has an effect on the spontaneous calcification of VICs and may also have a profound effect on the molecular properties of VICs as it relates to understanding the disease process in vivo.

Benton, Julie A.; Kern, Hanna B.; Anseth, Kristi S.

2009-01-01

364

Engineering systems for the generation of patterned co-cultures for controlling cell-cell interactions  

PubMed Central

Background Inside the body, cells lie in direct contact or in close proximity to other cell types in a tightly controlled architecture that often regulates the resulting tissue function. Therefore, tissue engineering constructs that aim to reproduce the architecture and the geometry of tissues will benefit from methods of controlling cell–cell interactions with microscale resolution. Scope of the review We discuss the use of microfabrication technologies for generating patterned co-cultures. In addition, we categorize patterned co-culture systems by cell type and discuss the implications of regulating cell-cell interactions in the resulting biological function of the tissues. Major conclusions Patterned co-cultures are a useful tool for fabricating tissue engineered constructs and for studying cell–cell interactions in vitro, because they can be used to control the degree of homotypic and heterotypic cell–cell contact. In addition, this approach can be manipulated to elucidate important factors involved in cell-matrix interactions. General significance Patterned co-culture strategies hold significant potential to develop biomimetic structures for tissue engineering. It is expected that they would create opportunities to develop artificial tissues in the future.

Kaji, Hirokazu; Camci-Unal, Gulden; Langer, Robert; Khademhosseini, Ali

2010-01-01

365

MEMS-based dynamic cell-to-cell culture platforms using electrochemical surface modifications  

NASA Astrophysics Data System (ADS)

MEMS-based biological platforms with the capability of both spatial placements and time releases of living cells for cell-to-cell culture experiments have been designed and demonstrated utilizing electrochemical surface modification effects. The spatial placement is accomplished by electrochemical surface modification of substrate surfaces to be either adhesive or non-adhesive for living cells. The time control is achieved by the electrical activation of the selective indium tin oxide co-culture electrode to allow the migration of living cells onto the electrode to start the cell-to-cell culture studies. Prototype devices have a three-electrode design with an electrode size of 50 × 50 µm2 and the separation gaps of 2 µm between them. An electrical voltage of -1.5 V has been used to activate the electrodes independently and sequentially to demonstrate the dynamic cell-to-cell culture experiments of NIH 3T3 fibroblast and Madin Darby canine kidney cells. As such, this MEMS platform could be a basic yet versatile tool to characterize transient cell-to-cell interactions.

Chang, Jiyoung; Yoon, Sang-Hee; Mofrad, Mohammad R. K.; Lin, Liwei

2011-05-01

366

Bupivacaine uncouples the mitochondrial oxidative phosphorylation, inhibits respiratory chain complexes I and III and enhances ROS production: results of a study on cell cultures.  

PubMed

This study aimed to validate, in situ, proposed mechanisms of bupivacaine cytotoxicity pointing to impairment of the mitochondrial oxidative metabolism. High resolution oxymetry, carried out on a panel of cell cultures, revealed a dual dose- and time-dependent effect of bupivacaine consisting of uncoupling of the mt Delta mu(H+)-controlled respiratory rates in a cyclosporine A-insensitive manner and further inhibition of the respiratory rates. Intriguingly, a relatively small decrease on the mt Delta Psi (about 20 mV) was sufficient to account for both the bupivacaine- and the FCCP-mediated impairment of the oxidative phosphorylation coupling thereby supporting a common protonophoric mechanism of action. The bupivacaine-induced depression of the cell respiration related to specific inhibition of complexes I and III and accompanied with production of reactive oxygen species. Importantly, inhibition of the respiratory chain complexes was prevented by antioxidant treatment and reversed following removal of the anaesthetic thereby suggesting an oxidant-mediated feed-back mechanism reinforcing the primary inhibitory action of the anaesthetic. PMID:20546950

Cela, Olga; Piccoli, Claudia; Scrima, Rosella; Quarato, Giovanni; Marolla, Alessandra; Cinnella, Gilda; Dambrosio, Michele; Capitanio, Nazzareno

2010-08-01

367

Transplantation with cultured stem cells derived from the human amniotic membrane for corneal alkali burns: an experimental study.  

PubMed

Amniotic membranes (AM) have been used in a wide range of clinical applications. We successfully extracted mesenchymal stem cells (MSCs) from human AM, but little is known about the use and efficacy of human amniotic membrane-derived mesenchymal stem cells (hAM-dMSCs) for the treatment of alkali burns. We utilized hAM-dMSCs transplantation, AM grafting, and their combined use in the treatment of alkali burns. An experimental model in rabbits was devised to analyze the use of these techniques with immunocytochemistry and ELISA. The survival and migration of hAM-dMSCs labeled by SPION in the host were assessed with Prussian blue staining. Compared with the control group, the treated groups demonstrated faster reconstruction of the corneal epithelium, and lower levels of corneal opacification and neovascularization within corneal alkali burns. Furthermore, dark blue-stained particles were detected in the limbus corneae at day 28. These results demonstrated the ability of hAM-dMSCs to enhance epithelial healing and reduce corneal opacification and neovascularization in corneal alkali wounds. PMID:24695478

Zeng, Wei; Li, Yanwei; Zeng, Guangwei; Yang, Bo; Zhu, Yu

2014-01-01

368

Neonatal rat heart cells cultured in simulated microgravity  

NASA Technical Reports Server (NTRS)

In vitro characteristics of cardiac cells cultured in simulated microgravity are reported. Tissue culture methods performed at unit gravity constrain cells to propagate, differentiate, and interact in a two-dimensional (2D) plane. Neonatal rat cardiac cells in 2D culture organize predominantly as bundles of cardiomyocytes with the intervening areas filled by nonmyocyte cell types. Such cardiac cell cultures respond predictably to the addition of exogenous compounds, and in many ways they represent an excellent in vitro model system. The gravity-induced 2D organization of the cells, however, does not accurately reflect the distribution of cells in the intact tissue. We have begun characterizations of a three-dimensional (3D) culturing system designed to mimic microgravity. The NASA-designed High-Aspect Ratio Vessel (HARV) bioreactors provide a low shear environment that allows cells to be cultured in static suspension. HARV-3D cultures were prepared on microcarrier beads and compared to control-2D cultures using a combination of microscopic and biochemical techniques. Both systems were uniformly inoculated and medium exchanged at standard intervals. Cells in control cultures adhered to the polystyrene surface of the tissue culture dishes and exhibited typical 2D organization. Cells cultured in HARVs adhered to microcarrier beads, the beads aggregated into defined clusters containing 8 to 15 beads per cluster, and the clusters exhibited distinct 3D layers: myocytes and fibroblasts appeared attached to the surfaces of beads and were overlaid by an outer cell type. In addition, cultures prepared in HARVs using alternative support matrices also displayed morphological formations not seen in control cultures. Generally, the cells prepared in HARV and control cultures were similar; however, the dramatic alterations in 3D organization recommend the HARV as an ideal vessel for the generation of tissuelike organization of cardiac cells in vitro.

Akins, R. E.; Schroedl, N. A.; Gonda, S. R.; Hartzell, C. R.

1997-01-01

369

Silicon substrate as a novel cell culture device for myoblast cells  

PubMed Central

Background Tissue and organ regeneration via transplantation of cell bodies in-situ has become an interesting strategy in regenerative medicine. Developments of cell carriers to systematically deliver cell bodies in the damage site have fall shorten on effectively meet this purpose due to inappropriate release control. Thus, there is still need of novel substrate to achieve targeted cell delivery with appropriate vehicles. In the present study, silicon based photovoltaic (PV) devices are used as a cell culturing substrate for the expansion of myoblast mouse cell (C2C12 cells) that offers an atmosphere for regular cell growth in vitro. The adherence, viability and proliferation of the cells on the silicon surface were examined by direct cell counting and fluorescence microscopy. Results It was found that on the silicon surface, cells proliferated over 7 days showing normal morphology, and expressed their biological activities. Cell culture on silicon substrate reveals their attachment and proliferation over the surface of the PV device. After first day of culture, cell viability was 88% and cell survival remained above 86% as compared to the seeding day after the seventh day. Furthermore, the DAPI staining revealed that the initially scattered cells were able to eventually build a cellular monolayer on top of the silicon substrate. Conclusions This study explored the biological applications of silicon based PV devices, demonstrating its biocompatibility properties and found useful for culture of cells on porous 2-D surface. The incorporation of silicon substrate has been efficaciously revealed as a potential cell carrier or vehicle in cell growth technology, allowing for their use in cell based gene therapy, tissue engineering, and therapeutic angiogenesis.

2014-01-01

370

Differential Effect of Culture Temperature and Specific Growth Rate on CHO Cell Behavior in Chemostat Culture  

PubMed Central

Mild hypothermia condition in mammalian cell culture technology has been one of the main focuses of research for the development of breeding strategies to maximize productivity of these production systems. Despite the large number of studies that show positive effects of mild hypothermia on specific productivity of r-proteins, no experimental approach has addressed the indirect effect of lower temperatures on specific cell growth rate, nor how this condition possibly affects less specific productivity of r-proteins. To separately analyze the effects of mild hypothermia and specific growth rate on CHO cell metabolism and recombinant human tissue plasminogen activator productivity as a model system, high dilution rate (0.017 h?1) and low dilution rate (0.012 h?1) at two cultivation temperatures (37 and 33°C) were evaluated using chemostat culture. The results showed a positive effect on the specific productivity of r-protein with decreasing specific growth rate at 33°C. Differential effect was achieved by mild hypothermia on the specific productivity of r-protein, contrary to the evidence reported in batch culture. Interestingly, reduction of metabolism could not be associated with a decrease in culture temperature, but rather with a decrease in specific growth rate.

Vergara, Mauricio; Becerra, Silvana; Berrios, Julio; Osses, Nelson; Reyes, Juan; Rodriguez-Moya, Maria; Gonzalez, Ramon; Altamirano, Claudia

2014-01-01

371

Endothelial cells stimulate growth of normal and cancerous breast epithelial cells in 3D culture  

PubMed Central

Background Epithelial-stromal interaction provides regulatory signals that maintain correct histoarchitecture and homeostasis in the normal breast and facilitates tumor progression in breast cancer. However, research on the regulatory role of the endothelial component in the normal and malignant breast gland has largely been neglected. The aim of the study was to investigate the effects of endothelial cells on growth and differentiation of human breast epithelial cells in a three-dimensional (3D) co-culture assay. Methods Breast luminal and myoepithelial cells and endothelial cells were isolated from reduction mammoplasties. Primary cells and established normal and malignant breast cell lines were embedded in reconstituted basement membrane in direct co-culture with endothelial cells and by separation of Transwell filters. Morphogenic and phenotypic profiles of co-cultures was evaluated by phase contrast microscopy, immunostaining and confocal microscopy. Results In co-culture, endothelial cells stimulate proliferation of both luminal- and myoepithelial cells. Furthermore, endothelial cells induce a subpopulation of luminal epithelial cells to form large acini/ducts with a large and clear lumen. Endothelial cells also stimulate growth and cloning efficiency of normal and malignant breast epithelial cell lines. Transwell and gradient co-culture studies show that endothelial derived effects are mediated - at least partially - by soluble factors. Conclusion Breast endothelial cells - beside their role in transporting nutrients and oxygen to tissues - are vital component of the epithelial microenvironment in the breast and provide proliferative signals to the normal and malignant breast epithelium. These growth promoting effects of endothelial cells should be taken into consideration in breast cancer biology.

2010-01-01

372

A Novel Feeder-Free Culture System for Expansion of Mouse Spermatogonial Stem Cells  

PubMed Central

Spermatogonial stem cells (SSCs, also called germline stem cells) are self-renewing unipotent stem cells that produce differentiating germ cells in the testis. SSCs can be isolated from the testis and cultured in vitro for long-term periods in the presence of feeder cells (often mouse embryonic fibroblasts). However, the maintenance of SSC feeder culture systems is tedious because preparation of feeder cells is needed at each subculture. In this study, we developed a Matrigel-based feeder-free culture system for long-term propagation of SSCs. Although several in vitro SSC culture systems without feeder cells have been previously described, our Matrigel-based feeder-free culture system is time- and cost- effective, and preserves self-renewability of SSCs. In addition, the growth rate of SSCs cultured using our newly developed system is equivalent to that in feeder cultures. We confirmed that the feeder-free cultured SSCs expressed germ cell markers both at the mRNA and protein levels. Furthermore, the functionality of feeder-free cultured SSCs was confirmed by their transplantation into germ cell-depleted mice. These results suggest that our newly developed feeder-free culture system provides a simple approach to maintaining SSCs in vitro and studying the basic biology of SSCs, including determination of their fate.

Choi, Na Young; Park, Yo Seph; Ryu, Jae-Sung; Lee, Hye Jeong; Arauzo-Bravo, Marcos J.; Ko, Kisung; Han, Dong Wook; Scholer, Hans R.; Ko, Kinarm

2014-01-01

373

Cultured buffalo umbilical cord matrix cells exhibit characteristics of multipotent mesenchymal stem cells.  

PubMed

Recent findings have demonstrated umbilical cord, previously considered as a biomedical waste, as a source of stem cells with promising therapeutic applications in human as well as livestock species. The present study was carried out to isolate the umbilical cord matrix cells and culture for a prolonged period, cryopreserve these cells and test their post-thaw viability, characterize these cells for expression of stem cell markers and differentiation potential in vitro. The intact umbilical cord was taken out of the amniotic sac of a fetus and then incised longitudinally to remove umbilical vessels. Wharton's jelly containing tissue was diced into small pieces and placed in tiny drops of re-calcified buffalo plasma for establishing their primary culture. Confluent primary culture was trypsinized and passaged with a split ratio of 1:2 for multiplication of cells. Cryopreservation of cells was performed at three different passages in cryopreservation medium containing 15%, 20% and 25% fetal bovine serum (FBS). A significant increase in post-thaw viability was observed in cells cryopreserved in freezing medium with higher concentration of FBS. After re-culturing, frozen-thawed cells started adhering, and spike formation occurred within 4-6 h with similar morphology to their parent representative cultures. The normal karyotype and positive expression of alkaline phosphatase and pluripotency genes OCT4, NANOG and SOX2 were observed at different passages of culture. When induced, these cells differentiated into adipogenic and osteogenic cells as confirmed by oil red O and alizarin red stains, respectively. This study indicates that buffalo umbilical cord matrix cells have stemness properties with mesenchymal lineage restricted differentiation and limited proliferation potential in vitro. PMID:23708916

Singh, Jarnail; Mann, Anita; Kumar, D; Duhan, J S; Yadav, P S

2013-06-01

374

Medium for development of bee cell cultures (Apis mellifera: Hymenoptera: Apidae).  

PubMed

A media for the production of cell cultures from hymenopteran species such as honey bee, Apis mellifera L. (Hymenoptera: Apidae) was developed. Multiple bee cell cultures were produced when using bee larvae and pupae as starting material and modified Hert-Hunter 70 media. Cell culture systems for bees solves an impasse that has hindered efforts to isolate and screen pathogens which may be influencing or causing colony collapse disorder of bees. Multiple life stages of maturing larvae to early pupae were used to successfully establish cell cultures from the tissues of the head, thorax, and abdomen. Multiple cell types were observed which included free-floating suspensions, fibroblast-like, and epithelia-like monolayers. The final culture medium, WH2, was originally developed for hemipterans, Asian citrus psyllid, Diaphorina citri, and leafhopper, Homalodisca vitripennis cell cultures but has been shown to work for a diverse range of insect species such as bees. Bee cell cultures had various doubling times at 21-23 degrees C ranging from 9-15 d. Deformed wing virus was detected in the primary explanted tissues, which tested negative by rt-PCR for Israeli acute paralysis virus (IAPV), Kashmir bee virus, acute bee paralysis virus, and black queen cell virus. Culture inoculation with IAPV from an isolate from Florida field samples, was detectable in cell cultures after two subcultures. Cell culture from hymenoptera species, such as bees, greatly advances the approaches available to the field of study on colony collapse disorders. PMID:20033792

Hunter, Wayne B

2010-02-01

375

Recombinant Protein Production and Insect Cell Culture and Process  

NASA Technical Reports Server (NTRS)

A process has been developed for recombinant production of selected polypeptides using transformed insect cells cultured in a horizontally rotating culture vessel modulated to create low shear conditions. A metabolically transformed insect cell line is produced using the culture procedure regardless of genetic transformation. The recombinant polypeptide can be produced by an alternative process using virtually infected or stably transformed insect cells containing a gene encoding the described polypeptide. The insect cells can also be a host for viral production.

Spaulding, Glenn F. (Inventor); Goodwin, Thomas J. (Inventor); OConnor, Kim C. (Inventor); Francis, Karen M. (Inventor); Andrews, Angela D. (Inventor); Prewett, Tracey L. (Inventor)

1997-01-01

376

Reversibly permeable hepatoma cells in culture.  

PubMed

A brief treatment of H35 hepatoma cells with lysolecithin resulted in a cell population which is permeable to low-molecular weight charged molecules that cannot normally cross the plasma membrane. These include deoxynucleotide and nucleotide triphosphates, folyl and methotrexate polyglutamates, and trypan blue. As a result dTTP can be incorporated into the DNA of the permeable cells, providing the required nucleotides and deoxynucleotides are added to the medium. This result, combined with only a slight observed loss (20-25%) in total cell protein, lactate dehydrogenase (EC 1.1.1.27) activity and tyrosine aminotransferase (EC 2.6.1.5) activity, demonstrated that permeation of the cells does not extensively disrupt membrane integrity. Further support for this view comes from the fact that the permeable cells could seal when placed in enriched medium. The process of sealing was inhibited by cycloheximide and tunicamycin. The sealed cells, whose surfaces appeared identical to those of untreated cells by scanning electron microscopy, were fully capable of cell division when exposed to serum. Values for several other parameters, including dexamethasone-dependent tyrosine aminotransferase induction, thymidine incorporation into DNA, leucine incorporation into protein and folate coenzyme transport, supported the conclusion that sealed cells and untreated H35 cells have identical properties. Based on the characteristics of the permeable and sealed H35 cells, a discussion of the experimental potential of these preparations for studying macromolecular synthesis, investigating enzymes in situ and depleting cells of folate coenzymes is presented. PMID:7171628

Balinska, M; Samsonoff, W A; Galivan, J

1982-11-17

377

Dual Circuit, Woven Artificial Capillary Bundle for Cell Culture.  

National Technical Information Service (NTIS)

An artificial capillary cell culture device having two separate perfusion circuits, and with the ultrafiltration fibers of the two circuits being woven into a single bundle, is disclosed. The device provides a matrix for high density growth of cultured ce...

R. A. Kanazek

1978-01-01

378

Dual Circuit, Woven Artificial Capillary Bundle for Cell Culture.  

National Technical Information Service (NTIS)

An artificial capillary cell culture device having two separate perfusion circuits, and with the ultrafiltration fibers of the two circuits being woven into a single bundle, is described. The device provides a matrix for high density growth of cultured ce...

R. A. Knazek

1978-01-01

379

Liquid Spouted Bed Culture of Microencapsulated Mammalian Cells,  

National Technical Information Service (NTIS)

Microencapsulated MPC11 cells, which are anchorage-independent, were tried to propagate in a newly designed liquid spouted bed culture system. As the culture system was suitable for separation of medium and microcapsules, the medium could be circulated su...

K. Funatsu M. Ketayama

1988-01-01

380

Effect of cryopreservation on human cytotrophoblast cells in culture: hCG and PALP production.  

PubMed

Term villous cytotrophoblasts differentiate into syncytiotrophoblast during culture exhibiting characteristic changes in cellular morphology and protein expression profiles. Measurement of human chorionic gonadotropin (hCG) and placental alkaline phospatase (PALP) is often used to assess viability and syncytialisation of cultured cells. The objective of this study was to assess the effect of cryopreservation of isolated cytotrophoblasts on the expression hCG and PALP by cells during subsequent culture. Villous cytotrophoblasts isolated from term placentae from uncomplicated pregnancies were either cultured immediately after isolation or were cryopreserved (liquid nitrogen) prior to culture. Cells were cultured in identical conditions (5% CO(2) in air) for 96 h. Protein and DNA co