ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • cell culture
  • Springer  (56)
  • American Institute of Physics (AIP)
  • Cell Press
  • 1990-1994  (56)
  • 1994  (19)
  • 1991  (37)
Collection
Publisher
  • Springer  (56)
  • American Institute of Physics (AIP)
  • Cell Press
  • Wiley-Blackwell  (16)
Years
  • 1990-1994  (56)
Year
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Cellular and molecular life sciences 50 (1994), S. 99-104 
    ISSN: 1420-9071
    Keywords: Microvascular endothelial cells ; cell culture ; interteron-γ ; cell growth
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Five cell types recently isolated from the bovine corpus luteum differed in their epithelioid morphology and their cytoskeleton, but shared common criteria of microvascular endothelial cells1,2. To give strong evidence for the separate entity, the growth rate of the 5 phenotypically different cells was studied. They were seeded at low density on day 0. Most of these cells were treated with 200 to 1000 U recombinant bovine interferon-γ (IFN-γ) for 3 days. The untreated remainder served as controls. Cell counts were made for all cultures on days 4, 7, 10 and 13. morphology: 13 d after treatment with IFN-γ senescent cells as well as intact cells occurred in cultures of cell types 1 to 4. Cultures of cell type 5 were apparently unchanged and resembled their untreated counterparts. Desminpositive cells in cultures of cell type 2 developed cell processes. Growth rate: In the absence of IFN-γ, the growth rate was high for cell types 3 and 4, moderate for cell type 1, and low for cell types 2 and 5. The presence of IFN-γ caused anti-proliferative effects. These were higher for cell types 3 and 4 than for cell types 1 and 2. IFN-γ could be cytotoxic on cell type 3. In contrast, the cytokine tended to support the cell growth of cell type 5. These findings substantiate the postulate that endothelial cells exhibiting separate morphology in culture also function differently.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Cytotechnology 15 (1994), S. 87-94 
    ISSN: 1573-0778
    Keywords: Adaptation ; ammonia ; cell culture ; glutamine ; glutamate ; dipeptides
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Although glutamine is used as a major substrate for the growth of mammalian cells in culture, it suffers from some disadvantages. Glutamine is deaminated through storage or by cellular metabolism, leading to the formation of ammonia which can result in growth inhibition. Non-ammoniagenic alternatives to glutamine have been investigated in an attempt to develop strategies for obtaining improved cell yields for ammonia sensitive cell lines. Glutamate is a suitable substitute for glutamine in some culture systems. A period of adaptation to glutamate is required during which the activity of glutamine synthetase and the rate of transport of glutamate both increase. The cell yield increases when the ammonia accumulation is decreased following culture supplementation with glutamate rather than glutamine. However some cell lines fail to adapt to growth in glutamate and this may be due to a low efficiency transport system. The glutamine-based dipeptides, ala-gln and gly-gln can substitute for glutamine in cultures of antibody-secreting hybridomas. The accumulation of ammonia in these cultures is less and cell yields in dipeptide-based media may be improved compared to glutamine-based controls. In murine hybridomas, a higher concentration of gly-gln is required to obtain comparable cell growth to ala-gln or gln-based cultures. This is attributed to a requirement for dipeptide hydrolysis catalyzed by an enzyme with higher affinity for ala-gln than gly-gln.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 1573-0778
    Keywords: Baculovirus ; cell culture ; Drosophila ; gene expression ; insect cell ; metallothionein promoter ; recombinant protein
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract In this report, we compare two different expression systems: baculovirus/Sf9 and stable recombinantDrosophila Schneider 2 (S2) cell lines. The construction of a recombinant S2 cell line is simple and quick, and in batch fermentations the cells have a doubling time of 20 hours until reaching a plateau density of 20 million cells/ml. Protein expression is driven by theDrosophila Metallothionein promoter which is tightly regulated. When expressed in S2 cells, the extracellular domain of human VCAM, an adhesion molecule, is indistinguishable from the same protein produced by baculovirus-infected Sf9 cells. Additionally, we present data on the expression of a seven trans-membrane protein, the dopamine D4 receptor, which has been successfully expressed in both systems. The receptor integrates correctly in the S2 membrane, binds [3H]spiperone with high affinity and exhibits pharmacological characteristics identical to that of the receptor expressed in Sf9 and mammalian cells. The general implications for large scale production of recombinant proteins are discussed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    ISSN: 1573-0778
    Keywords: Mycoplasma ; cell culture ; clinical testing ; microbial screening ; PCR
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract The polymerase chain reaction (PCR) has been used for the general detection ofMollicutes. 25Mycoplasma andAcholeplasma species were detected including important contaminants of cell cultures such asM. orale, M. arginini, M. hyorhinis, M. fermentans, A. laidlawii and additional human and animal mycoplasmas. PCR reactions were performed using a set of nested primers defined from conserved regions of the 16S rRNA gene. The detection limit was determined to be 1 fg mycoplasma DNA, which is equivalent to 1–2 genome copies of the 16S rRNA coding region. The identity of the amplification products was confirmed by agarose gel electrophoresis and restriction enzyme analysis. DNA from closely and distantly related micro-organisms did not give rise to specific amplification products. The method presented here offers a much more sensitive, specific and rapid assay for the detection of mycoplasmas than the existing ones.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Cytotechnology 16 (1994), S. 147-150 
    ISSN: 1573-0778
    Keywords: Hybridoma ; peptone ; monoclonal antibody ; cell culture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Hybridoma WuT3 secreting a monoclonal antibody against T lymphocytes was grown in RPMI 1640 medium supplemented with 1% human serum. The effect of the concentration of peptone, as an additive, was investigated on cell growth, monoclonal antibody formation, and cell metabolism over 0–10 g l−1 range. It was found that 1–5 g l−1 peptone can significantly promote the growth of cells and increase the formation of monoclonal antibody, especially at 3–5 g l−1, when both the accumulating level and secretion rate of monoclonal antibody are higher than that at other peptone concentrations. Based on glucose, lactate and ammonia analysis data, the efficiency of glycolysis was assessed and the utilization of amino acids was more efficient at 3–5 g l−1 peptone. The cell growth and monoclonal antibody formation were inhibited at higher peptone concentrations, e.g. 10 g l−1.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Pharmaceutical research 11 (1994), S. 77-82 
    ISSN: 1573-904X
    Keywords: gastric epithelium ; cell culture ; cytoprotection ; sucralfate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Primary rat gastric cell cultures were investigated as an in vitro model for evaluating antiulcer agents. Following exposure to concentrations of up to 5 mg/mL of an antiulcer agent sucralfate, an aluminum hydroxide complex of sucrose octasulfate, cultured cells were treated with either pH 3.5 medium or 3.5 mM indomethacin. Cytoprotection was evaluated by colony forming efficiency, neutral red uptake, and 3-(4,5-dimethyl-2-thiazoyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) hydrolysis. By each measure, and depending on damaging agent, 2 and 5 mg/mL sucralfate provided partial (50% of untreated control) to near-complete (90% of untreated control) cytoprotection, respectively. Aluminum hydroxide also provided partial (55% of untreated control) to near-complete (more than 90% of untreated control) cytoprotection at 2 and 5 mg/mL, respectively, for the pH 3.5 medium-induced damage. Over a concentration range of 0.05 to 5 mg/mL, the potassium salt of sucrose octasulfate, KSOS, stimulated cell growth up to 40–60% over untreated controls but had little or no cytoprotective action in the presence of either 3.5 mM indomethacin or pH 3.5 medium. Overall results suggested that sucralfate may have at least two roles in influencing gastric epithelial cell function, cytoprotection and stimulation of cell growth in vitro. These observations serve as a basis for further study of in vitro models in evaluating the cytoprotective activity of antiulcer agents and their respective mechanisms of action.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    ISSN: 1573-5168
    Keywords: Atlantic salmon ; turbot ; cell culture ; salinity ; growth ; lipids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The direct effects of osmotic pressure (salinity) on growth performance and lipid composition were investigated in fish cells in culture. Cell lines from a relatively stenohaline marine species, turbot (Scophthalmus maximus) (TF) and an anadromous species, Atlantic salmon (AS) were cultured in media supplemented with NaCl to produce osmotic pressures varying from 300 to 500 mOsm kg−1. The growth rates of the two cell lines were affected in a similar manner by the salinity of the media with the rank order for both peak cell numbers and growth rates up to the day of peak cell number being 300 〉 350 〉 400 〉 450 〉 500 mOsm kg−1. Cell death occurred in both cell lines in older cultures at all salinities with the greatest loss of viable cells in media of 300 and 350 kg−1. However, there were quantitative and qualitative differences between the cell lines in their lipid metabolism in response to the salinity of the media. The lipid content expressed per cell showed a positive correlation between lipid per cell and salinity in TF cells, but this was less apparent in AS cells. The percentage of total polar lipid classes increased with increasing salinity in TF cells due mainly to graded increases in the percentages of choline phospholipids. In contrast, there were no significant differences in the proportions of polar and neutral lipid classes with salinity in AS cells. The only significant effect of salinity in AS cells was a decreased proportion of dimethylacetals in total lipid at the highest salinity. The same significant effect of salinity on dimethylacetal content of total lipid was observed in TF cells. However, in addition there was a graded decrease in the percentage of 18:2n-9 in TF cell total lipid with increasing salinity. This was accompanied by increased percentages of total n-3 and n-6 PUFA with higher proportions of both groups of PUFA at 450 and 500 compared with 300 mOsm kg−1. The results show that environmental salinity, in the absence of hormonal or other physiological stimuli, has direct effects on the growth and lipid metabolism of fish cells and that these effects differ in cells from different fish species.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Plant cell, tissue and organ culture 38 (1994), S. 189-198 
    ISSN: 1573-5044
    Keywords: Anthranilate synthase ; cell culture ; chorismate mutase ; elicitor induction ; Ruta graveolens ; shikimic acid pathway
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In vitro cultures of Ruta graveolens L. respond with rapid accumulation of acridone epoxides, furoquinolines and furanocoumarins, when challenged with autoclaved homogenate of the yeast Rhodotorula rubra. A transient increase of several enzymes of the respective biosynthetic pathways was measured but we still look for the key regulatory enzymes. We investigated whether the branch point enzymes of the shikimic acid pathway anthranilate synthase (AS) and chorismate mutase (CM) possibly play such a role. The two enzymes compete for chorismate. AS forms anthranilate, the precursor amino acid of acridone and furoquinoline alkaloids. CM channels chorismate into phenylalanine, tyrosine and phenylpropanoid biosynthesis. Elicitation resulted in a transient increase of the activity of both enzymes. Relative induction rates were 2–4 fold for AS and about 1.5 fold for CM. Constitutive CM activity, however, is about 1000 fold higher than AS activity. As in other plants 2 isoforms of CM are expected to be present in R. graveolens. A differential determination of the activity of the isoforms via the tryptophan activation rate proved to be ambiguous. Some evidence for the specific induction of a plastidic form of CM was obtained by inhibition of translation. The time courses of CM induction show CM not to be a key enzyme in elicitor induction of furanocoumarin accumulation. In comparison to other enzyme activities induction of anthranilate synthase activity corresponds closest to inducible acridone epoxide accumulation indicating a key role in its regulation. Induction of AS and CM was inhibited by actinomycin D and chloramphenicol while cycloheximid inhibited AS induction only.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    ISSN: 1573-5044
    Keywords: cell culture ; enzyme inactivation ; H2O2 ; oxydative burst ; Picea abies ; Rhizosphaera kalkhoffii
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Elicitation of suspension culture cells of spruce [Picea abies (L.) Karst] with a fungal cell wall preparation of the spruce pathogenic fungus Rhizosphaera kalkhoffii Bubak induced inactivation of extracellular enzymes. Extracellular peroxidase, β-glucosidase and acid phosphatase, secreted by the cells during growth, and also α-amylase and pectinase from Aspergillus strains, added to an elicited cell culture, were inactivated. Inactivation is caused by an elicitor-mediated transient release of H2O2 from the cells (oxidative burst). H2O2 released into the medium was determined with ABTS (2,2'-Azino-bis-(3-ethylbenthiazoline-6-sulfonate)) (formation of blue colour) and with phenol red (destruction of pH indicator). The release started only minutes after beginning of elicitation and its inactivating effect existed for more than 1 day. Release of H2O2 is a biphasic process with a first smaller maximum at 1 h, followed by a second larger increase, peaking at 5–6 h and returning to approximately the control levels thereafter. Also H2O2 is transiently released in small quantities from cell incubations in the absence of elicitor as a stress response of the cells to manipulations of the cultures. Extracellular enzymes secreted into the medium could also be inactivated by direct addition of exogenous H2O2. Catalase prevents inactivation of the secreted extracellular enzymes, however, to a limited extent only because, as a result of contact of cells and medium, catalase becomes inactivated. The ionophores A 23187 and cycloheximide induced release of H2O2 and, when present together with elicitor, induction was synergistically increased.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Plant cell, tissue and organ culture 39 (1994), S. 245-250 
    ISSN: 1573-5044
    Keywords: asparagine ; cell culture ; Glycine max L. ; nitrogen metabolism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A photoautotrophic soybean suspension culture was used to study free amino acid pools during a subculture cycle. Free amino acid analysis showed that the intracellular concentrations of asparagine, serine, glutamine, and alanine reached peaks of 200, 10, 9 and 7 mM, respectively, at specific times in the 14-day subculture cycle. Asparagine and serine levels peaked at day 14 but glutamine level rose quickly after subculture, peaking at day three and then declined gradually. Roughly similar patterns were found in the conditioned culture medium although the levels were 1000-fold lower than those found in cells. Photoautotrophic (SB-P) and photomixotrophic (SB-M) cultures were quantitatively similar with regard to free asparagine and serine but not glutamine or free ammonia. Heterotrophic (SB-H) cells had 81–85% less free asparagine on day seven than did SB-M or SB-P cells. Hence, similar to the phloem sap of a soybean plant, asparagine, glutamine, alanine and serine were the predominant amino acids in photoautotrophic soybean cell cultures. Varying the amount of total nitrogen in culture medium for two subcultures at 10, 25, 50, and 100% Of normal levels showed that growth was inhibited only at the 10 and 25% levels but that growth on medium containing 50% of the normal nitrogen was as good as that on 100% nitrogen. Moreover, cellular chlorophyll content correlated exceptionally well with initial nitrogen content of the medium. Thus, the photosynthesis of SB-P cells was not limited by chlorophyll content. SB-P cells grown for two subcultures on 10% nitrogen contained very low free amino acid levels and only 1% of the free ammonia levels found in cells growing on a full nitrogen complement.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 11
    Electronic Resource
    Electronic Resource
    Springer
    Plant cell, tissue and organ culture 38 (1994), S. 39-43 
    ISSN: 1573-5044
    Keywords: cell culture ; image analysis ; Petunia hybrida ; protoplast ; perfluorocarbon ; surfactant
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Image analysis has been used to assess the growth of cell suspension-derived protoplasts of Petunia hybrida cv. Comanche at an interface between aqueous culture medium (KM8P), supplemented with 0.01% (w/v) Pluronic F-68, and oxygenated (10 mbar; 10 min) perfluorodecalin. Protoplasts synthesised a new cell wall and entered normal mitotic division which was sustainable to the cell colony/callus stage. This process was accentuated by the collective and additive effects of oxygen, perfluorodecalin and surfactant media supplements. The mean area (mm3) of protoplast-derived cell colonies after 68 days of growth was increased 35 fold over control (media alone) in the presence of these combined treatments. The new cultural regime, leading to improved cell throughput from protoplasts, is discussed primarily in relation to the role of perfluorodecalin as a gas carrier and possible effects of Pluronic F-68 in stimulating cellular uptake of nutrients and/or growth regulators. Image analysis provides a novel and accurate approach to quantifying cell growth responses.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 12
    Electronic Resource
    Electronic Resource
    Springer
    Plant cell, tissue and organ culture 36 (1994), S. 81-90 
    ISSN: 1573-5044
    Keywords: acid phosphatase ; α-amylase ; cell culture ; enzyme inactivation ; fungal elicitor ; β-glucosidase ; pectinase ; peroxidases ; Picea abies ; Rhizosphaera kalkhoffii
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Extracellular peroxidases of suspension cultures of spruce (Picea abies) (L.) (Karst) become inactivated when the cell suspension is elicited with a cell wall preparation of the spruce pathogenic fungus Rhizosphaera kalkhoffii. In contrast, cellular peroxidases are induced under these conditions. Both changes of activity are reflected in the isoenzyme profiles. Inactivation of the extracellular peroxidases is caused by an effector, arising from the cells after contact with the elicitor. Formation of the effector is limited to the beginning of elicitation, showing maximal activity at this period of time. Subsequently it becomes increasingly ineffective, probably due to inactivation. The effector is able to also inactivate commercial (horseradish) peroxidase. Inactivation was not the result of the action of a protease present in the medium. The elicitor exerts two different effects on the spruce cell suspension culture. It induces synthesis of enzymes correlated with lignin synthesis and an accumulation of lignin-like material. It also induces secretion of the negative effector which inactivates extracellular peroxidases. The elicitor-induced inactivation is not specific for peroxidases. Other extracellular enzymes, β-glucosidase and acid phosphatase (secreted by the cells into the medium) and α-amylase and pectinase (from Aspergillus strains) are also inactivated.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 13
    ISSN: 1573-5044
    Keywords: Airlift-reactor ; cell culture ; Chenopodium rubrum ; growth characteristics ; photoautotroph ; semicontinuous cultivation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract An airlift-bioreactor system was established for semicontinuous growth of photosynthetically active plant cell suspension cultures in a controlled environment. The bioreactor unit was constructed as a conventional, internal draught tube airlift-reactor, which is characterized by a H D-1 ratio of 2.9, a ratio of the cross-sectional area of the riser to the cross-sectional area of the downcomer of 0.25 and a surface area of 0.435 m2 for illumination. Cultivation experiments could be scaled up to working volumes of maximal 20 1. Sixteen fluorescent tubes were fixed around the outer glass cylinder to provide cells continuously with light. An external cooling device was used to keep the temperature constantly at 27°C. Agitation as well as supply with CO2 was performed by injecting air enriched with CO2 through a ring-shaped sparger at the bottom of the vessel. A first set of experiments was carried out with a photoautotrophic culture of Chenopodium rubrum L. Cell material adapted to large scale culture conditions was used to inoculate a modified MS medium (Murashige & Skoog 1962) without any organic constituents. Under these conditions a biomass increase of 1870% was achieved in 18 days. Several physiological parameters (e.g. pigmentation, photosynthetic O2 evolution, carbohydrate content) were measured routinely to elucidate the growth characteristics of large-scale grown Chenopodium cells. Electron microscopic photographs from different phases of culture growth clearly demonstrate the pattern of cellular development. Special emphasis was placed upon the differentiation of chloroplast ultrastructure. The presented data confirm the feasibility of large-scale culture techniques with photosynthetic active plant cell cultures.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 14
    Electronic Resource
    Electronic Resource
    Springer
    Cell biology and toxicology 10 (1994), S. 155-162 
    ISSN: 1573-6822
    Keywords: in vitro cytotoxicity ; cell culture ; protein synthesis ; proline incorporation ; radiolabeling ; cellular protein ; pollen tube growth inhibition ; MEIC
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract This study was designed to compare the cytotoxic concentrations of chemicals, determined with three independentin vitro cytotoxicity testing protocols, with each other and with established animal LD50 values, and against human toxic concentrations for the same chemicals. Ultimately, these comparisons allow us to evaluate the potential ofin vitro cell culture methods for the ability to screen a variety of chemicals for prediction of human toxicity. Each laboratory independently tested 50 chemicals with known human lethal plasma concentrations and LD50 values. Two of the methods used monolayer cell cultures to measure the incorporation of radiolabeled amino acids into newly synthesized proteins and cellular protein content, while the third technique used the pollen tube growth test. The latter is based on the photometric quantification of pollen tube mass production in suspension culture. Experiments were performed in the absence or presence of increasing doses of the test chemical, during an 18- to 24-h incubation. Inhibitory concentrations were extrapolated from concentration-effect curves after linear regression analysis. Comparison of the cytotoxic concentrations confirms previous independent findings that the experimental IC50 values are more accurate predictors of human toxicity than equivalent toxic blood concentrations (HETC values) derived from rodent LD50s. In addition, there were no conclusive statistical differences among the methods. It is anticipated that, together, these procedures can be used as a battery of tests to supplement or replace currently used animal protocols for human risk assessment.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 15
    ISSN: 1573-6822
    Keywords: cardiac myocytes ; cell culture ; chicken embryonic cells ; contractility ; digital image analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Quantitative image analysis is used to measure the inotropic and chronotropic effects of drugs on cultured heart cells maintained at 37°C on the stage of an inverted light microscope, and sequentially superfused with control and treatment media. The beating of the cardiac myocytes is evaluated by simultaneously selecting up to eight areas, including cell edges, from digitized video image. The sizes and positions of these areas are controlled by the operator. To analyze the motion of cell edges in each area, the computer measures the shift of the mass center of pixels' grey levels. Finally, a few parameters are calculated for the eight areas and displayed graphically. In order to assess treatment effects, appropriate statistical tests are performed on the data. Image analysis is an efficient screening test for evaluating the pharmacologic or toxic effects of a substance on isolated or cultured cardiac myocytes from various species.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 16
    ISSN: 1573-4986
    Keywords: cell culture ; epitectin ; mucin-type glycoprotein ; nude mice ; tumorigenicity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Epitectin is a high molecular weight mucin-type glycoprotein over-expressed on the surface of human carcinoma cells. In cancer cells, it is proposed to play a protective function and to modulate cell surface properties such as antigenicity and cell adhesion. We have examined the effect of long-term culture on the cell curface expression of epitectin by a human laryngeal carcinoma cell line and the correlation between epitectin expression and tumor production in athymic mice. Indirect immunofluorescence labelling using an epitectin specific monoclonal antibody showed that the level of epitectin on the cell surface was significantly reduced after 78 or more generations in culture. Gel electrophoresis of cell extracts, followed by wheat germ agglutinin and peanut agglutinin overlay analyses, demonstrated similar losses in total cellular epitectin as a result of prolonged passage in culture. The levels of other glycoproteins reacting with wheat germ agglutinin were not significantly altered in high passage cells. Similar results were obtained when HMFG-2 monoclonal antibody was used to probe the levels of cell surface epitectin. In contrast to the above probes, the binding of HMFG-2 to epitectin is independent of glycosylation, therefore it can be concluded that the observed changes are not due to aberration in epitectin glycosylation with increasing passage number but rather due to lack of synthesis of epitectin. The ability of the low epitectin producing H.Ep.2 cells to grow as tumors in athymic mice was reduced compared to the high epitectin producing cells.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 17
    Electronic Resource
    Electronic Resource
    Springer
    Bulletin of experimental biology and medicine 117 (1994), S. 307-310 
    ISSN: 1573-8221
    Keywords: somatotropic hormone ; cell culture ; pituitary ; insulin ; postnatal development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract It is shown that insulin is able to alter the secretion of somatotropic hormone directly at the level of the pituitary. The direction of the regulatory effect of insulin depends on the age of the animals donating the pituitary cells, while the intensity of the effect of insulin is largely modulated by glucocorticoid and thyroid hormone.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 18
    ISSN: 1573-8221
    Keywords: eyelid plasty ; transplant extract ; DNA synthesis ; cell culture ; ALLOPLANT TM
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Extract isolated from a collagen-containing transplant (series ALLOPLANTTM), which is used in the treatment of benign and malignant neoplasms of the eyelid, inhibits DNA synthesis in the cellin vitro. This effect is nonspecific, reversible, and dose-dependent. The extract is thermostable and resistant to proteolytic enzymes.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 19
    ISSN: 1573-8221
    Keywords: low-density lipoproteins ; sialic acid ; cell culture ; metabolism of low-density lipoproteins
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract It is shown that binding of native LDL to fibroblasts expressing the B,E-receptors is twice as high as that of desialylated LDL. An excess of acetylated LDL inhibits binding, uptake, and degradation of125I-desialylated LDL by macrophages, while an excess of desialylated LDL inhibits binding, uptake, and degradation of acetylated LDL. Desialylated LDL may interact with both B,E and scavenger receptors.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 20
    ISSN: 1573-0832
    Keywords: Fumonisin B1 ; fumonisin B2 ; AAL toxin ; T-2 toxin ; mycotoxin ; Fusarium moniliforme ; bioassay ; cell culture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Fumonisins B1 and B2 and AAL toxin are a series of structurally related mycotoxins. Fumonisins B1 and B2, produced by Fusarium moniliforme Sheldon induce toxic hepatitis and hepatomas in rats and leukoencephalomalacia in horses. The cancer-promotion assay which has been used to guide their purification is slow and consumes large amounts of sample. We have examined a series of cultured mammalian cell lines in order to develop a more rapid and sensitive bioassay system, which may be useful for examining structure-activity relationships and the mechanism(s) of action of these toxins. Of 9 rat hepatoma cell lines tested, all except the two most de-differentiated lines were sensitive to the three toxins, with a toxic response visible by 48 h. Approximate IC50 values for the most sensitive hepatoma line, H4TG, were 4, 2 and 10 μg/ml for fumonisins B1, B2 and AAL toxin, respectively „in 100 μl cultures. Among 15 cell lines from other sources, only MDCK dog kidney epithelial cells were sensitive (IC50 = 2.5, 2 and 5 μg/ml, respectively). Studies in co-cultures of sensitive and insensitive cell lines and in cultures of a sensitive cell line over a range of cell densities indicated that cytotoxicity of fumonisins B1 and B2 does not involve metabolite activation to a derivative stable enough to diffuse to adjacent cells.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 21
    Electronic Resource
    Electronic Resource
    Springer
    Methods in cell science 13 (1991), S. 45-48 
    ISSN: 1573-0603
    Keywords: cell culture ; corneal epithelium ; primary explant
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary An improved procedure for the primary culture of pure human corneal epithelial cells from corneal explants is described. Confluent monolayers of epithelial cells can be consistently produced from small segments of donor corneas regardless of donor age and without feeder layers. Incubating segments on collagen at the air-liquid interface significantly improves the yield of cells per cornea and shortens cell migration time as compared to culturing on plastic. Fibroblast contamination is eliminated by serum-free medium and confirmed by indirect immunofluorescent staining for keratin.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 22
    Electronic Resource
    Electronic Resource
    Springer
    Methods in cell science 13 (1991), S. 143-147 
    ISSN: 1573-0603
    Keywords: kidney ; renal cortex ; proximal tubule ; enzymatic dissociation ; cell culture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary A procedure is described for the establishment and propagation of epithelial cell rich cultures derived from normal human kidney cortex (NHK-C cells). Cells are harvested from tissue fragments of donor human kidney by progressive enzymatic dissociation. NHK-C cultures are morphologically heterogeneous but exhibit, predominantly, the functional characteristics of cells of the kidney proximal tubule.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 23
    ISSN: 1432-203X
    Keywords: anthocyanin ; cell culture ; nitrate ; sucrose ; Vitis vinifera
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In pigmented cells of Vitis vinifera suspension cultures, best accumulation of anthocyanins was obtained when nitrate concentration was reduced from 25 mM to 6.25 mM and when sucrose concentration was increased from 88 mM to 132 mM. Under such conditions growth was greatly decreased. However, cell viability was maintained. The increases in anthocyanins in pigmented cells were due largely to increases in peonidin — glucoside. The high sucrose and the low nitrate concentrations can be one of the important culture factors in controlling of anthocyanin production by cell cultures.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 24
    Electronic Resource
    Electronic Resource
    Springer
    Molecular and cellular biochemistry 108 (1991), S. 151-156 
    ISSN: 1573-4919
    Keywords: cytochrome P-450 ; mitochondria ; heme ; hepatocytes ; mitochondrial DNA ; cell culture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract This study examined various biochemical parameters such as mitochondria and mitochondrial DNA (mtDNA), total heme and cyto P450 content in fresh hepatocytes and dedifferentiated hepatocytes. These parameters were chosen in order to understand the dramatic decrease in drug metabolism in cultured hepatocytes. The data in this study shows a temporal decrease in cytochrome P450, total heme and also a decrease in mitochondria. Also, the ratio of mtDNA content to mitochondrial density was found to increase as hepatocytes underwent dedifferentiation. Stereological analysis of cell preparations provided a measure of mitochondrial density per cell area and mtDNA content was assessed by the use of a specific radiolabelled probe. This study demonstrates that a loss of the organelle which is partially responsible for synthesis of heme correlates with a decrease in cytochrome P450.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 25
    Electronic Resource
    Electronic Resource
    Springer
    Molecular and cellular biochemistry 104 (1991), S. 35-43 
    ISSN: 1573-4919
    Keywords: α1-adrenergic receptors ; β-adrenergic receptors ; cardiac muscle ; cell culture ; gene expression ; protein kinase C
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract The molecular mechanisms of cardiac myocyte growth are relevant to important problems in cardiovascular disease. A cell culture model has been developed to explore the role of adrenergic hormones in cardiac myocyte growth and gene expression. Activation of a cardiac myocyte α1-adrenergic receptor by catecholamines induces hypertrophic growth of neonatal rat cardiac myocytes and initiates selective increases in contractile protein gene transcription. These effects on growth and gene expression do not depend on contractile activity. The cardiac myocytes contain at least two subtypes of α1-adrenergic receptors and at least three isoforms of protein kinase C (PKC). A distinct α1 receptor subtype may mediate hypertrophy and gene transcription. Different isoforms of PKC are translocated to different intracellular sites on activation, and there is evidence that the β-PKC isoform may be an element in the signal transduction pathway from an α1 receptor at the surface to the cardiac myocyte nucleus. Growth regulation through a β-adrenergic receptor can also be demonstrated in the culture model. The growth response mediated through a β-adrenergic receptor differs in several respects from that transduced through an al adrenergic receptor.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 26
    Electronic Resource
    Electronic Resource
    Springer
    Plant molecular biology 16 (1991), S. 167-169 
    ISSN: 1573-5028
    Keywords: Phaseolus vulgaris ; cell culture ; chalcone isomerase ; elicitor
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 27
    Electronic Resource
    Electronic Resource
    Springer
    Plant molecular biology 16 (1991), S. 739-740 
    ISSN: 1573-5028
    Keywords: Lupinus polyphyllus ; cell culture ; cDNA clone ; ribosomal protein ; rps 16
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 28
    ISSN: 1573-5028
    Keywords: tobacco ; 5-enolpyruvylshikimate-3-phosphate synthase ; cDNA clone ; gene expression ; gene amplification ; glyphosate ; cell culture ; tolerance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Two distinct cDNAs for 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) were obtained from a glyphosate-tolerant tobacco cell line. The cDNAs were 89% identical and the predicted sequences of the mature proteins were greater than 83% identical with EPSPS proteins from other plants. Tobacco EPSPS proteins were more similar to those from tomato and petunia than Arabidopsis. One cDNA clone, EPSPS-1, represented a gene that was amplified in glyphosate-tolerant cells, while the gene for EPSPS-2 was unaltered in these cells. Consequently, EPSPS-1 mRNA was more abundant in tolerant than unselected cells, whereas EPSPS-2 mRNA was at relatively constant levels in these cell lines. Exposure of unselected cells and tobacco leaves to glyphosate produced a transient increase in EPSPS mRNA. However, glyphosate-tolerant cells containing amplified copies of EPSPS genes did not show a similar response following exposure to glyphosate. A significant proportion of the EPSPS gene amplification was maintained when tolerant cells were grown in the absence of glyphosate for eight months. Plants regenerated from these cells also contained amplified EPSPS genes.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 29
    ISSN: 1573-0778
    Keywords: cell culture ; lymphocyte ; lymphokine-activated killer cell ; recombinant interleukin 2 ; serum-free medium
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract We examined a serum-free medium (designated as TYI 101) for the generation of lymphokine-activated killer (LAK) cells from human lymphocytes, regional lymph node lymphocytes (RLNL) and peripheral blood lymphocytes (PBL). TYI 101 medium consisted of, in addition to nutrient mixture, transferrin, insulin, fetuin, sodium selenite, 2-mercaptoethanol, o-phosphorylethanolamine, chick egg yolk and porcine kidney extract. These hormones were effective for supporting RLNL proliferation as assessed by (3H)-thymidine uptake. When human lymphocytes from two different sources were cultivated with recombinant interleukin 2 (rIL-2) in TYI 101 medium, LAK activity was generated. In cultures of PBL from a healthy donor, LAK cells were generated in TYI 101 medium as efficiently as in RPMI 1640 medium supplemented with 10% human AB-type serum (RPMI-AB). In cultures of RLNL from lung cancer patients, LAK activity obtained in TYI 101 medium was about sixty-five percent of that in RPMI-AB. However, the addition of a small amount of AB-type serum improved the generation of LAK activity, LAK cell expansion, and cell viability in TYI 101 medium. We conclude that TYI 101 medium can be used for the generation of LAK cells from human lymph node lymphocytes with supplementation of none or only a reduced amount of human serum.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 30
    ISSN: 1573-0778
    Keywords: adoptive immunotherapy ; cell culture ; cell culture apparatus ; Interleukin-2 ; lymphokine-activated killer cells
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract We recently developed a new culture system based on dialysis perfusion (designated JCC-device) for the generation and expansion of human lymphokine-activated killer (LAK) cells (Murata et al., 1990). More recently we have scaled up the volume of the culture vessel of the JCC-device from 100 ml to 400 ml for clinical use. In the present study, using this new 400 ml JCC-device, we cultured human lymph node lymphocytes (LNL) obtained from 8 surgical patients with primary lung cancer, and investigated the cellular characteristics in comparison with a conventional batchwise culture system using tissue culture dishes. With the JCC-device, the cell density reached a maximum 2.7×107 cells/ml with greater than 90% viability by the appropriate exchange of perfusion medium and by making additions at the appropriate intervals for recombinant interleukin-2 (rIL-2). The expansion fold of LNL with the JCC-device, ranging 6.6- to 19.2-fold (mean 13.8-fold), was not significantly different from that in dish cultures. There was no marked difference in cell surface phenotypes between the two culture systems in 7 out of 8 cases. As for LAK activity of LNL, the JCC culture was either superior or equal in 4 out of 8 cases, but inferior in the other 4 cases to the conventional dish cultures. In the latter cases, the usage of serum for the JCC culture was limited, which might have resulted in the low LAK activity. The JCC-device was able to reduce the consumption of basal medium, rIL-2 and serum by 20%, 84% and 96%, respectively compared to the conventional tissue culture systems. The JCC-device improved the routine performance of adoptive immunotherapy with LAK cells and rIL-2.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 31
    Electronic Resource
    Electronic Resource
    Springer
    Cytotechnology 7 (1991), S. 121-130 
    ISSN: 1573-0778
    Keywords: cell culture ; cellulose sulphate ; encapsulation ; monoclonal antibodies ; poly-dimethyl-diallyl-ammoniumchloride
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract A new encapsulation method was developed for the cultivation of mammalian cells. The capsules were produced using a solution of sodium cellulose sulphate (CS)(1.5%) and poly-dimethyl-diallyl-ammoniumchloride (PDMDAAC). When CS droplets fell into the precipitation bath consisting of a 2% solution of PDMDAAC, immediately a membrane at the interphase was built up. The influences of varying encapsulation process parameters on capsule characteristics, cell growth, and monoclonal antibody production were tested. This new method showed advantages when compared to other methods mainly due to time simplicity of the whole process.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 32
    Electronic Resource
    Electronic Resource
    Springer
    Cytotechnology 5 (1991), S. 31-46 
    ISSN: 1573-0778
    Keywords: serum-free ; cell culture ; carcinoma
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 33
    Electronic Resource
    Electronic Resource
    Springer
    Fish physiology and biochemistry 9 (1991), S. 261-269 
    ISSN: 1573-5168
    Keywords: Cortisol ; RU 486 ; temperature ; rainbow trout ; cell culture ; [3H]-Thymidine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The rainbow trout gonadal cell line, RTG-2, which survives temperatures from 0 to 28°C and proliferates at 5 to 26°C, responded to cortisol from 28°C to 0°C by influencing [3H]-thymidine incorporation into DNA. Over the normal temperature range of rainbow trout, 10–22°C, cortisol inhibited [3H]-thymidine incorporation. The antiglucocorticoid RU 486 had no effect on [3H]-thymidine incorporation at these temperatures and blocked the response to cortisol. Another antiglucocorticoid RU 362 also had no effect but was less effective in blocking the cortisol response. During incubation at 28°C this inhibitory response to cortisol was detected inconsistently during the first 24 h but was observed consistently during the second 24 h. At 0°C, cortisol and RU 486 had no effect during short treatments, but a 60 h exposure to either steroid stimulated [3H]-thymidine incorporation over a 48 h labelling period. These results suggest that temperature shifts between 10–22°C, do not change the direction of a response to cortisol and support the use of the upper portion (20–22°C) of the temperature range for studies on salmonid cells in culture.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 34
    ISSN: 1573-5044
    Keywords: ammonium ; anthocyanin ; cell culture ; growth kinetics ; production medium ; Vitis vinifera
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Cultivating Vitis vinifera cell suspensions in a production medium which is characterized by high sucrose and low nitrate concentrations (132 mM and 6.25 mM respectively) repressed growth but enhanced the intracellular accumulation of anthocyanins, especially peonidin 3-glucoside. Increasing the ammonium concentration of the production medium from 2 to 8–16 mM increased growth and decreased the accumulation of anthocyanins and peonidin 3-glucoside specifically. Instead, peonidin 3-p-coumaroylglucoside accumulated. At 24 mM ammonium concentration, growth was inhibited and accumulation of peonidin 3-p-coumaroylglucoside was significant (p〈0.05) and represented 42% of total anthocyanins after 12 days of culture compared with 19% in the production medium with 2 mM ammonium.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 35
    Electronic Resource
    Electronic Resource
    Springer
    Plant and soil 130 (1991), S. 75-80 
    ISSN: 1573-5036
    Keywords: cell culture ; FeHEDTA ; Glycine max ; iron chelate reduction ; iron nutrition ; soybean
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The abilities of suspension cultures and intact roots of soybean (Glycine max L. cv. Hawkeye) to reduce ferric chelate were compared. Ferric chelate was supplied as ferric hydroxyethylethylenediaminetriacetic acid (FeHEDTA) and reduction was measured spectrophotometrically using bathophenan-throlinedisulfonic acid (BPDS) as the ferrous scavenger. Ferric chelate reduction by cell suspension cultures showed typical saturation kinetics; however, no difference was observed between cells that had been continuously grown with Fe (+Fe) and those that had been grown for four days without added Fe (−Fe). Values for Km and Vmax, determined from a Lineweaver-Burk plot, were 57 μM and nmoles mg-1 dry weight for the +Fe cells and 50 μM and 22 nmoles mg-1 dry weight for the -Fe cells, respectively. Ferric chelate reduction by Fe-deficient roots also exhibited saturation kinetics, while roots grown with adequate Fe did not reduce ferric chelate. The Km and Vmax values for Fe-deficient roots were 45 μM and 20 nmoles mg-1 dry weight, respectively, and did not differ from values obtained for cells in culture. This study offers strong evidence that the mechanism responsible for the reduction of ferric chelate is the same for cultured cells and roots and that the process is controlled at the cellular level. We propose that suspension cultures can be used as an alternative to intact roots in the study of ferric chelate reduction.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 36
    ISSN: 1573-5117
    Keywords: callus ; cell culture ; domestication ; protoplast ; tissue culture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Cellular biotechnology is a promising application in the propagation and selection of superior strains of seaweeds. Although axenic cultures, organogenetic tissue cultures, vegetative micro-propagation, callus induction and high yields of agar from calli have been described for several species of Gelidium, a number of basic problems remain to be solved. These include standardized methods for obtaining axenic cultures, identification of requirements for organic nutrients, PGR's, cellular disorganization and reorganization, somaclonal variation and somatic incompatibilities. Future progress in seaweed biotechnology will depend on the resolution of many of these problems.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 37
    Electronic Resource
    Electronic Resource
    Springer
    Hydrobiologia 227 (1991), S. 187-192 
    ISSN: 1573-5117
    Keywords: Turbellaria ; planaria ; cell culture ; leucine uptake
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We have tested various conditions for the culture of cells dispersed from planarians. The cells were procurred by digestion of planarian tissue in pronase and filtering through a nylon mesh. Using incorporation of L-[3H]leucine into protein as a gauge of cell growth, we found that the optimum salt concentration was about 50% of that for mammalian cells (about 160 mOsm) and that optimum pH was about 8. Sera from several species and a tetrapeptide (Arg-Gly-Asp-Ser, the cell-attachment sequence in fibronectin) greatly increased leucine uptake and extended cell survival up to a period of about two weeks. Various growth factors and some other substances tested had no effect on uptake of leucine, cell morphology, or survival. A few other compounds tested were cytotoxic. None of the experimental media promoted cell proliferation.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 38
    Electronic Resource
    Electronic Resource
    Springer
    Plant cell, tissue and organ culture 26 (1991), S. 53-59 
    ISSN: 1573-5044
    Keywords: cell culture ; cell wall ; conditioned medium ; inoculum density ; low inoculum growth factor ; Pinus radiata
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Pinus radiata cells in suspension culture abruptly lose their growth capacity when diluted below a critical inoculum density. This threshold density can be lowered by adding the supernatant (conditioned medium) from healthy cultures which have been grown separately at high densities. Fresh medium is conditioned rapidly indicating that the factor responsible is either potent or produced rapidly. Activity-response curves increase progressively with concentration indicating that still greater effect may be obtained if the factor can be concentrated following separation from other medium components. The effect is not mimicked by a number of candidate compounds (including auxins, cytokinins, polyamines and vitamins). Partial characterisation studies indicate that the factor is relatively small (〈1 000 dalton) and possibly an oligosaccharide. It is considered that the factor is an essential structural component of the walls of expanding cells where it is reversibly-bound.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 39
    ISSN: 1573-6830
    Keywords: acetylcholinesterase ; asymmetric-form types ; chick hindlimb muscle ; development ; cell culture ; diisopropylfluorophosphate inactivation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary 1. We have analyzed the behavior of two types of asymmetric molecular forms (A forms) of acetylcholinesterase (AChE) during development of chick hindlimb muscle,in vivo and in cell culture, and upon irreversible inactivation of peroneal muscle AChE with diisopropylfluorophosphate (DFP)in vivo. 2. In agreement with previous developmental studies on chick muscle, globular forms of AChE (G forms) are predominant in chick hindlimb at early embryonic ages, being gradually replaced by A forms as hatching (and, therefore, onset of locomotion) approaches. Of the two A-form types, AI appears and accumulates significantly earlier than AII, so that A/G and II/I ratios higher than 1 are attained only at about hatching time. 3. Cultures prepared from 11-day chick embryo hindlimb myoblasts express both types of A forms, with a combined activity of 27% of total AChE after 12 days in culture. AI forms appear again earlier and are much more abundant than type II asymmetric species through the life span of cultures. 4. All AChE activity in the peroneal muscle is irreversibly inactivated by injection of DFPin vivo. The recovery of A forms follows the same sequence described for normal development, with a delayed and slower recovery of AII forms as compared with AI. 5. Several hypotheses involving tail polypeptides or tissue target molecules, or posttranslational interconversion, are proposed to help explain the earlier appearance and accumulation of AI forms in chick muscle.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 40
    Electronic Resource
    Electronic Resource
    Springer
    Plant cell, tissue and organ culture 24 (1991), S. 49-54 
    ISSN: 1573-5044
    Keywords: anthocyanin ; cell culture ; osmotic potential ; reverse-phase HPLC ; Vitis vinifera
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Cell cultures of grapes, Vitis vinifera L. cv Gamay Fréaux were grown under different conditions of external osmotic potential induced by an increase of sucrose concentration or by the addition of mannitol to the culture medium. Addition of 82 mM mannitol or increasing sucrose concentration to 132 mM had similar effects on repressing growth. Cyanidin 3-glucoside, peonidin 3-glucoside and peonidin 3-p-coumaroylglucoside are three main anthocyanins of Vitis cells. Increasing osmotic potential from −0.43 MPa to −0.8 MPa in the medium resulted in a significant intracellular accumulation of anthocyanin especially peonidin 3-glucoside in the pigmented cells. High osmotic potential appears to stimulate the methylation of anthocyanins. Osmotic potential is an important culture factor and may be useful in the controlling of anthocyanin production and composition.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 41
    Electronic Resource
    Electronic Resource
    Springer
    Plant cell, tissue and organ culture 24 (1991), S. 207-210 
    ISSN: 1573-5044
    Keywords: anthraquinone production ; cell culture ; Galium vernum ; polymeric adsorbents ; secretion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Anthraquinones produced by suspension cultures of Galium vernum are completely retained intracellularly. Surprisingly, in the presence of some polymeric adsorbents anthraquinones are partially released into the culture medium. The secretion and in situ removal stimulates anthraquinone production in cell cultures of Galium vernum. Best results were obtained with Wofatit ES and Amberlite XAD-2.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 42
    Electronic Resource
    Electronic Resource
    Springer
    Plant cell, tissue and organ culture 25 (1991), S. 147-152 
    ISSN: 1573-5044
    Keywords: cell culture ; Daucus carota ; 2-deoxy-D-glucose ; invertase ; selection
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Variant carrot (Daucus carota L.) cell lines resistant to the growth inhibitory effects of the glucose analogue 2-deoxy-D-glucose (dGlc) were isolated utilizing a feeder plate technique. Growth of sensitive cells was less than 7.5% of controls on medium supplemented with 3.0 mM dGlc, whereas resistant variants achieved growth ranging from 15% to 70% of that in controls. Increased levels of acid invertase activity in variant cell lines in response to dGlc in the culture medium, together with decreased sensitivity of the acid invertase enzyme (EC 3.2.1.26) to dGlc, is proposed as one of several potential mechanisms contributing to the observed dGlc resistance.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 43
    ISSN: 1573-0603
    Keywords: bronchial epithelium ; cell culture ; intermediate filaments ; carbohydrate cytochemistry ; lectins ; peroxidase-labeled lectins
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary A protocol is presented for correlating the morphology of human bronchial epithelial cells after Papanicolaou staining with their periodic acid schiff (PAS)/AB-reactivity, intermediate filament type, and the pattern of staining with lectins having specific affinities for glycoconjugates:griffionia simplicifolia (GSA-IB4; terminal alpha-d-galactose),Dolichos biflorus (DBA,N-acetyl-d-galactosamine). The combination of these stains identified differentiation markers in morphologic studies of normal, transformed, and malignant bronchial epithelial cells in culture.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 44
    ISSN: 1573-0603
    Keywords: pH ; NH 4 + ; BCECF ; human kidney ; proximal tubule ; cell culture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary This protocol describes the use of the pH-sensitive, intracellularly trapped dye 2′,7′-bis (2-carboxyethyl), 5 (and -6) carboxyfluorescein (BCECF), to characterize the pH regulating mechanisms in cultured human kidney proximal tubule cells. This is a reliable method for intracellular pH measurements and is applicable to single cells, cell suspensions, and confluent cultures.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 45
    Electronic Resource
    Electronic Resource
    Springer
    Methods in cell science 13 (1991), S. 285-288 
    ISSN: 1573-0603
    Keywords: DNA ; fluorimetry ; fibroblast ; cell culture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary An improved direct fluorimetric assay is described using bisbenzimidazol fluorescence at 356 nm excitation and 458 nm emission wavelengths. The turbidity of the medium was shown to have no effect on fluorescence under an absorbance of 0.2 at the excitation wavelength. The method was evaluated by comparisons with a colorimetric DNA assay and cell counting. The linearity of fluorescence was determined up to 15μg/ml of DNA. The method was very reproducible and sensitive to detect 10 ng/ml of DNA and may be used for cell suspensions containing around 5000 cells/ml or more.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 46
    Electronic Resource
    Electronic Resource
    Springer
    Methods in cell science 13 (1991), S. 289-294 
    ISSN: 1573-0603
    Keywords: fetal bovine ; oviduct ; cell culture ; microscopy ; immunocytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Bovine epithelial cell monolayers were obtained for culture from fetal oviduct after in situ trypsinization. Isolated ciliated and secretory cells obtained in high yield with good viability were suspended in B2-MENEZO'S medium supplemented with 7.5% fetal bovine serum FBS. The plated primary cultures reached confluency 2 days after initial seeding, producing a monolayer of cohesive polygonal cells with viability of 85 to 95%. Associated with this large epithelial cell population, ciliated cells as well as a few elongated spindle cells were observed. After the first subculture the ciliated cells disappeared and the epithelial cells in the monolayer grew more rapidly to confluence than adult-derived cultures. In addition, frozen-thawed oviduct epithelial cells also maintained a level of 75 to 85% viability during postthaw subculture. The epithelial cells maintained their secretory activity in culture as indicated by electron microscopy and immunocytochemistry. The cell culture monolayers contained keratin, a specific cytoskeletal component of epithelial cells. This culture system may offer benefits for in vitro culture of mammalian embryos.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 47
    Electronic Resource
    Electronic Resource
    Springer
    Plant cell, tissue and organ culture 26 (1991), S. 195-201 
    ISSN: 1573-5044
    Keywords: Brassica napus ; cell culture ; diffusion ; liquid medium ; oxygen availability ; protoplast culture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A method for estimating the oxygen availability in plant cell cultures grown in stationary liquid media (e.g. many protoplast cultures) was developed. The method is based on short-term measurements of respiration rate versus oxygen concentration on a sample of cells, suspended in liquid media. From such data it is possible to estimate the oxygen concentration at the bottom of a stagnant liquid culture, by calculating the amount of oxygen reaching the cells by diffusion. As an example, rape (Brassica napus L. cv. Omega) hypocotyl protoplasts were grown with different oxygen concentrations at the site of the cells, obtained by varying the cell density, the height of the liquid layer and the oxygen content of the gas phase. The number of surviving calli was positively correlated with the estimated oxygen availability in the range between 60 and 350 μM O2, below 60 μM all cells died. This indicates that oxygen availability can be a limiting factor in the range usually encountered in protoplast cultures, and that the method can be useful when designing optimal growth conditions for stationary cultures of plant cells.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 48
    Electronic Resource
    Electronic Resource
    Springer
    Plant cell, tissue and organ culture 27 (1991), S. 267-274 
    ISSN: 1573-5044
    Keywords: cell culture ; enzyme induction ; fungal elicitor ; l-phenylalanine ammonia-lyase ; Picea abies
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The activity of l-phenylalanine ammonia-lyase (PAL) (EC 4.3.1.5) was determined in seedlings, callus cells, cell suspension cultures and in young needles of spruce (Picea abies) (L.) (Karst). PAL activity increased up to 10 fold in response to transferring suspension cultured cells into new cultivation medium. PAL was also induced about 10 fold when callus cells were transferrd into liquid medium. The increase was transient and it required the presence of a carbohydrate. In cell suspension cultures, grown in the dark (white cells), but not in light-grown cultures (green cells), PAL activity was induced up to 30 fold by UV-light. With a cell wall preparation of Rhizosphaera kalkhoffii, a forest pathogenic fungus, used as elicitor, the activity of PAL could be induced more than 10 fold. The degree of induction depended on the elicitor concentration. Induction was prevented by cycloheximide but not by actinomycin D.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 49
    Electronic Resource
    Electronic Resource
    Springer
    Cellular and molecular neurobiology 11 (1991), S. 579-591 
    ISSN: 1573-6830
    Keywords: proteoglycans ; glycosaminoglycans ; mouse retina ; photoreceptors ; retinal neurons ; cell culture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary 1. In recent years, a number of histochemical and immunocytochemical studies have suggested that proteoglycans, particularly those in the inter-photoreceptor matrix, exhibit altered distributions in several murine models for retinal degenerations. We are using a cell culture system to characterize the proteoglycans synthesized by neurons and photoreceptors derived from mouse retina, with the long-term goal of analyzing their role in retinal degenerations. 2. In this study we describe initial studies using cells derived from the retinas of normal mice. Cultures of retinal neurons and photoreceptors, which were free of glial, epithelia, or endothelial cells, were labeled with3H-glucosamine and35SO4. Proteoglycans isolated from the medium and cell layer were analyzed on the basis of charge, relative hydrodynamic size, and glycosaminoglycan content. 3. The studies indicate that the cultures actively synthesize proteoglycans. The medium contained predominantly chondroitin sulfate/dermatan sulfate, while the cell layer had a higher proportion of heparan sulfate, indicating a differential distribution between the two compartments.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 50
    Electronic Resource
    Electronic Resource
    Springer
    Cytotechnology 5 (1991), S. 15-30 
    ISSN: 1573-0778
    Keywords: high density ; cell culture ; serum-free medium ; hybridoma ; CHO cells ; virus production ; insect cells ; adoptive immunotherapy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Conclusion At the 1989 annual meeting of the U.S. Tissue Culture Associations, Ricahrd am, a leading investigator in the serum-free nutrient requirements of cultured cells, commented on the process of medium development. He noted that a survey of major media manufacturers revealed that, among the top selling mammalian cell culture media formulations, most were nearly thirty years old. This commentary is noteworthy considering the tremendous changes in cell culture understanding and derived applications which have emerged over these three decades. Fastidious cell types relatively unknown to investigators of the 1950s and 1960s are now being cultivated in defined, serum-free environments. Culture environments range from limiting dilution clonal recoveries to maintenance cultures approaching tissue densities. While research applications continue to predominate, applications of cell culture have expanded to the engineered production of biopharmaceuticals, to replacement of animal models for toxicology testing, and to the preservation, activation and expansion of human cells, tissues and organs. It is likely that future nutrient medium development will be predicated upon the design of a minimal number of defined formulations of relatively generic utility to a broad class of cell types. Analytical techniques derived from those described herein will be exploited in the user laboratory and in collaboration with the supplier to optimize the nutrient composition for the desired biological response.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 51
    ISSN: 1573-0778
    Keywords: cell culture ; kinetics ; Ig promoter/enhancer ; plasmacytoma ; recombinant protein production
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract A model mammalian cell system for the production of recombinant proteins was investigated. Murine myeloma cells which had lost the ability to produce both heavy and light chain immunoglobulin molecules were transfected with a vector containing the immunoglobulin heavy chain promoter and enhancer elements linked to the human growth hormone gene. The growth kinetics of G32, a clonal isolate, were found to be similar to both the parent myeloma and hybridomas. However, production of hGH by G32 was growth associated, rather than as a secondary metabolite as is the case for hybridomas. In addition, G32 produced hGH at molar levels greater than most hybridomas.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 52
    Electronic Resource
    Electronic Resource
    Springer
    Cytotechnology 6 (1991), S. 49-54 
    ISSN: 1573-0778
    Keywords: Bivalvia ; cell culture ; embryo ; mitosis ; scallop
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Primary cell cultures obtained from embryos of Mizuchopecten yessoensis (Bivalvia) survived for four months. Although the number of cells progressively decreased during the cultivation, mitotic cells were observed both at the first stages and at the end. A possibility of growing marine invertebrates cells in long term primary culture is discussed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 53
    ISSN: 1573-0778
    Keywords: cell culture ; endosteal human osteoblasts ; maxilla ; mandible ; titanium ; biocompatibility ; alkaline phosphatase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Fragments of cancellous and cortical bone from human maxilla and mandible were cultured by the explant technique. Cells isolated by trypsinization of primary cultures were characterized as osteoblasts on the basis of intracellular alkaline phosphatase activity, the constituents of the extracellular matrix, and response to human parathormone (PTH). In culture, the osteoblasts often gave rise to superposed clumps of large cells whose cytoplasm contained endoplasmic reticulum, numerous mitochondria, vacuoles, and a dense network of intermediate filaments, often at the level of the plasma membrane. In the presence of vitamin C and 1,25-dihydroxyvitamin D3, the osteoblasts produced an extracellular matrix composed of collagen type I and various non-collagenous proteins, including osteocalcin. Biochemical test results were comparable to those reported for osteoblasts of other origins (rat calvaria, human iliac crest), and namely elevated intracellular alkaline phosphatase activity and cAMP accumulation in response to stimulation by human PTH (1–34). Osteoblasts isolated in this manner were cultured in the presence of pure titanium disks to determine the effects of exposure to this metal. Electron microscopy revealed few significant differences in cell growth and specific enzyme activity compared to control osteoblasts grown on plastic dishes, reflecting the excellent biologic and biochemical relationship between the osteoblasts and pure titanium. This experimental system thus appears suitable for biocompatibility studies, and in particular, evaluation of dental implants.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 54
    ISSN: 1573-904X
    Keywords: Caco-2 ; unstirred water layer ; intestinal permeability ; steroids ; cell culture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Caco-2 monolayers grown on Transwell polycarbonate membranes have been characterized as a valuable tool in drug transport studies. Despite the clear advantages of this system, the lack of stirring may create an unstirred water layer (UWL) whose resistance may limit the transcellular transport of lipophilic molecules. The objective of this study was to evaluate a novel diffusion cell where the transport buffer is mixed by gas lift and to determine the mixing flow rate needed to reduce the thickness (h) of the UWL adjacent to cell monolayers. The transport of the leakage marker, mannitol, remained at least 15-fold lower than the flux of testosterone, indicating that the stirring flow rates used did not affect the integrity of the monolayers. The permeability (P) of testosterone (log PC 3.13) across monolayers mounted on this diffusion cell was 4.07, 10.90, and 14.18 × 10−5 cm/sec at flow rates of 0, 15, and 40 ml/min, respectively, and the apparent UWLs were calculated to be 1966, 733, and 564µm. P and h in the stagnant Transwell were 3.08 × 10−5 cm/sec and 2597 µm, respectively. On the other hand, h was significantly smaller in the unstirred, cell-free membranes than in their cell-containing counterparts. P was correlated with lipophilicity and, in the case of the more lipophilic compounds, with the mixing flow rate.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 55
    Electronic Resource
    Electronic Resource
    Springer
    Pharmaceutical research 8 (1991), S. 1453-1460 
    ISSN: 1573-904X
    Keywords: peptide ; transport ; permeability ; lipophilicity ; hydrogen bonding ; cell culture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The relationship between structure and permeability of peptides across epithelial cells was studied. Using confluent monolayers of Caco-2 cells as a model of the intestinal epithelium, permeability coefficients were obtained from the steady-state flux of a series of neutral and zwitterionic peptides prepared from D-phenylalanine and glycine. Although these peptides ranged in lipophilicity (log octanol/water partition coefficient) from −2.2 to +2.8, no correlation was found between the observed flux and the apparent lipophilicity. However, a strong correlation was found for the flux of the neutral series and the total number of hydrogen bonds the peptide could potentially make with water. These results suggest that a major impediment to peptide passive absorption is the energy required to break water–peptide hydrogen bonds in order for the solute to enter the cell membrane. This energy appears not to be offset by the favorable introduction of lipophilic side chains in the amino acid residues.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 56
    Electronic Resource
    Electronic Resource
    Springer
    Bulletin of experimental biology and medicine 112 (1991), S. 1152-1156 
    ISSN: 1573-8221
    Keywords: experimental leprosy ; synthetic tuftsin ; cell culture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...