ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Rationale for the selection and use of in vitro assays to screen for chemopreventive agents (1997)
    Springer
    Methods in cell science 19 (1997), S. 1-2 
    Details
    ISSN: 1573-0603
    Keywords: Chemoprevention ; In vitro assays ; Drug screening
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract This issue reports the methods of twelve in vitro assays currently being used to screen potential chemopreventive agents for activity. These assays provide quantitative data to help determine the efficacy and prioritize agents for further development in whole animal screening. It is essential that such in vitro assays provide accurate, consistent, and relevant data to identify and prioritize agents with the most promise to prevent human cancer. The twelve assays presented in this volume are currently providing such data to the National Cancer Institute's Chemoprevention Program.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1009772307902
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Chemoprevention of carcinogen-induced transformation in primary rat tracheal epithelial cells (1997)
    Springer
    Methods in cell science 19 (1997), S. 3-8 
    Details
    ISSN: 1573-0603
    Keywords: Antineoplastic agents ; Cell transformation ; Chemoprevention ; Epithelial cells ; Respiratory tract
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract This rat tracheal epithelial (RTE) focus inhibition assay is designed to provide information on the anticarcinogenic properties of potential chemopreventive (CP) agents. The assay uses cultured primary RTE cells and measures the inhibition of morphological transformation induced by the carcinogen, benzo[a]pyrene (B[a]P). RTE cells are used as a model for human respiratory epithelial cells, a major target tissue of carcinogens, to provide data to help evaluate the anticarcincogenic potential of CP agents. In the assay, primary RTE cells are treated with the carcinogen B[a]P for 24 hours in the presence of the test CP agent. After 30 days, foci of morphologically transformed, precancerous cells are identified and inhibition is scored as a decrease in the number of these foci compared to the B[a]P-alone treated cultures. The RTE assays provides important data for agent selection prior to whole animal screening assays in the development of chemoprevention drugs.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1009714624740
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    The A427 anchorage-independence assay as a screening tool to identify potential chemopreventive agents (1997)
    Springer
    Methods in cell science 19 (1997), S. 9-12 
    Details
    ISSN: 1573-0603
    Keywords: Anchorage-independent growth ; Chemoprevention ; Human lung tumor cells ; In vitro model
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract An in vitro model for screening potential chemopreventive agents using inhibition of anchorage-independent growth of a human lung tumor cell line, A427, is described. A427 cells were selected for the model development, as they are known to be tumorigenic in animals, can grow in soft agarose, and their growth can be inhibited by a well-known chemopreventive agent, 13-cis-retinoic acid. Cells are plated on agarose, allowed to develop colonies for 28 days, the stained colonies are enumerated, and the inhibition of spontaneous colony formation measured. A cytotoxicity test is used concurrently with anchorage independent assay for measuring the relative survival of cells to ensure that any observed inhibition of anchorage independent growth is due to the biological activity of the chemopreventive agents, as it uses human cells as substrates rendering the efficacy data feasible for direct extrapolation to humans.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1009766608811
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    An ornithine decarboxylase activity assay to screen for potential chemopreventive agents (1997)
    Springer
    Methods in cell science 19 (1997), S. 33-36 
    Details
    ISSN: 1573-0603
    Keywords: Chemopreventive agent ; Ornithine decarboxylase ; Tracheal epithelial cells ; Tumor promoter
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A unique assay method to detect ornithine decarboxylase (ODC) activity in normal tracheal epithelial cells induced by a classic tumor promoter, 12-O-tetradecanoyl-phorbol-13-acetate (TPA) has been developed. Using this new assay, the inhibition of induced ODC activity is measured, thereby providing a screening system to identify potential chemopreventive or therapeutic agents. The assay is designed to be specific as it detects a radioactively labeled reaction product, putrescine from the decarboxylation of ornithine by ODC. As TPA is a classical tumor promoter, inhibition TPA-induced ODC activity can also be used to select antitumor promoter agents. Since the assay requires only 2 days to complete, it can be used to screen a large number of compounds for chemopreventive activity in a relatively short period of time.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1009794520990
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Identification of chemopreventive agents by screening for induction of glutathione-S-transferase as a biomarker (1997)
    Springer
    Methods in cell science 19 (1997), S. 49-52 
    Details
    ISSN: 1573-0603
    Keywords: Glutathione-S-transferase ; Human liver cells ; Phase II enzyme
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract For selection and identification of potential chemopreventive agents, a biochemical assay using induction of a phase II enzyme, glutathione-S-transferase (GST) in a liver cell culture is described. A normal human liver cell line (Chang liver cells) was selected as the candidate cell line for induction of GST (liver tissues are abundant in GST) by a known chemopreventive agent, oltipraz. Exponentially growing cells plated for 24 hours are exposed to various doses of a chemopreventive agent for an additional 24 hours, homogenized by sonication, and the homogenate is assayed for GST in a modified microplate enzyme assay using CDNB (1-chloro-2,4-dinitrobenzene) as a substrate. A concurrent protein assay is performed to determine the specific enzyme activity. As the assay is modified from a spectrophotometric assay to a microplate assay, it is reliable, sensitive and fast, a significant number of test agents can be screened in a short time.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1009750705969
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    The human epidermal cell asay for chemopreventive agents (1997)
    Springer
    Methods in cell science 19 (1997), S. 13-18 
    Details
    ISSN: 1573-0603
    Keywords: Carcinogen biomarker ; Chemoprevention ; Growth inhibition ; Human keratinocytes ; In vitro toxicity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Methods are described for a human keratinocyte assay for screening cancer preventive agents. Normal human keratinocytes at the first or second subculture are seeded into multi-well dishes. Cultures are repeatedly exposed to the carcinogen, propane sultone, and nontoxic concentrations of potential chemopreventive agents. At the end of the exposure period, the cultures are evaluated for growth and involucrin expression. Data are analyzed to determine the potential for test agents to inhibit propane sultone induced growth or to induce involucrin expression relative to that in propane sultone treated controls.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1009718725649
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    The human epithelial cell cytotoxicity assay for determining tissue specific toxicity (2000)
    Springer
    Methods in cell science 22 (2000), S. 17-24 
    Details
    ISSN: 1573-0603
    Keywords: Albumin ; Bronchial cells ; Chemoprevention ; Ecto-cervical cells ; Growth inhibition ; Hepatocytes ; Human ; In vitro ; Keratinocytes ; Mammary epithelial cells ; Mitochondrial function ; Normal ; Oral mucosal cells ; PCNA ; Prostate epithelial cells ; Renal cells ; Toxicity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The Human Epithelial Cell Cytotoxicity (HECC) Assay for determining organ specific cytotoxicity uses human epithelial cells from eight different human tissues, including: skin, mammary, prostate, renal, bronchial, oral, ecto-cervix, and liver. Although the initial studies using this assay were conducted using cancer chemopreventive agents, the HECC Assay can also be used to evaluate other types of drugs, personal care products, environmental chemicals, and potential toxicants. Human epithelial cells at an early passage are seeded into multi-well dishes. The cells are exposed to multiple concentrations of a test agent for a three day period. The concentration ranges for test agents in the assay are determined in a preliminary assay using an exposure of five days and log dilutions from the highest soluble concentration. At the end of the exposure period, the cultures are evaluated for inhibition of growth. In the HECC Assay, cultures are exposed for three days. At the end of the exposure period, the cultures are evaluated for inhibition of growth, mitochondrial function, and PCNA expression or albumin synthesis (hepatocytes). Data are analyzed to determine the concentration that inhibited and point by 50 percent (TC50). Values for each agent in each target epithelial cell line or culture and the target tissue specific sensitivity are compared to determine the relative sensitivity of each epithelial cell line to the test agent.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1009832830130
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Guidance for development of chemopreventive agents (1994)
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 56 (1994), S. 25-31 
    Details
    ISSN: 0730-2312
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcb.240560904
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Introductory remarks: Development of chemopreventive agents for prostate cancer (1992)
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 50 (1992), S. 1-8 
    Details
    ISSN: 0730-2312
    Keywords: chemoprevention ; clinical trials ; intermediate biomarkers ; prostate ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: The term “cancer chemoprevention” refers to the prevention of cancer by intervening with drugs prior to the malignant (i.e., invasive) stage of carcinogenesis. The development of chemopreventive drugs is the major objective of the Chemoprevention Branch at the National Cancer Institute.The testing of drug for cancer chemoprevention differs from testing of those for cancer treatment. Chemopreventive drug trials involve healthy target populations, and the endpoints of reduced cancer incidence or mortality, reduced/eliminated precancerous lesions, or increased latency must be achieved with little or no drug toxicity.The design of cancer chemoprevention trials for prostate presents several problems, such as the age of the study population and undependable methods for detecting microscopic foci by sequential sampling. A major motivation for organizing this workshop is the development of strategies for the design of chemopreventive intervention trials for prostate cancer.One of the most difficult problems of chemoprevention drug testing is the necessity of lengthy trials due to the long developmental period of many cancers. This is especially true for prostate cancer. A major solution to the problem is the use of intermediate biomarkers, defined as morphological or molecular intraepithelial changes that can constitute short-term endpoints in chemoprevention clinical trials. They are categorized as histological, genetic, proliferation-related, and differentiation-related. Modulation of intermediate biomarkers, instead of cancer incidence, as trial endpoints would allow chemoprevention trials to be of shorter duration, to use fewer subjects, and to be of lower cost. Review of the current status of prostatic intermediate biomarkers, and methods for identifying and validating them, are also major reason for convening this workshop. © 1992 Wiley-Liss, Inc.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcb.240501203
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Chemoprevention of rat mammary carcinogenesis: Exceptional activity of dietary dehydroepiandrosterone (DHEA) (1993)
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 53 (1993), S. 253-254 
    Details
    ISSN: 0730-2312
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: A major determinant of progress in human breast cancer prevention is the identification of agents with significant anticarcinogenic activity and acceptable levels of toxicity in experimental animals. Over the past 20 years, more than 50 experimental regimens have been shown to have significant chemopreventive activity in the rat mammary gland. The most effective approaches to mammary cancer chemoprevention in rats involve surgical endocrine ablations such as bilateral ovariectomy. However, prophylactic surgical ablations are unlikely to be acceptable to the majority of the general public. All chemicals evaluated to date are less effective, and none has been shown to reduce mammary cancer incidence to zero. As a result, efforts continue to identify chemical agents whose protective activity is comparable to that of endocrine ablation. DHEA is an adrenal steroid with chemopreventive activity in several animal models for human cancer. In the present studies, the chemopreventive efficacy of DHEA was evaluated in rats exposed to the mammary gland carcinogen, N-methyl-N-nitrosourea (MNU). Groups of 20 female Sprague-Dawley rats were fed an AIN-76A diet supplemented with 0, 400, or 800 mg DHEA per kg diet; one week later, all rats received a single i.p. injection of 35 mg MNU per kg body weight. Animals were palpated weekly to monitor mammary tumor development, and all mammary tumors were histologically confirmed. When administered at 800 mg/kg diet, DHEA reduced mammary cancer incidence in controls from 95% to 15%; carcinoma multiplicity in rats receiving 800 mg DHEA per kg diet was reduced by more than 85% from control levels. In a separate study, the 400 mg/kg diet dose of DHEA reduced the incidence of mammary cancer to 5% from 80% found in controls fed the basal diet. Reductions in mammary cancer incidence and multiplicity associated with DHEA administration were accompanied by large increases in cancer latency. Evaluation of mammary gland wholemounts from animals fed DHEA demonstrated a massive induction of lobuloalveolar differentiation. These results indicate the dietary supplementation with non-toxic dose levels of DHEA has chemopreventive efficacy approaching that of endocrine ablation. This protection may be mediated by the induction of differentiation in the mammary gland, during which sensitive mammary parenchymal structures (terminal end buds) are stimulated to develop into structures (alveolar buds) less sensitive to carcinogenic insult.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcb.240531154
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...