Library

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
    L1210 leukemia i. v. implanted as a model for testing short-chain nitrosourea analogs (1986)
    Springer
    Journal of cancer research and clinical oncology 111 (1986), S. 31-34 
    Details
    ISSN: 1432-1335
    Keywords: Nitrosourea analogs ; L1210 Leukemia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A total of 11 newly synthesized 2-chloroethyl-nitrosoureas and 1 2-fluoroethylnitrosourea with short-chain substituents were tested for their cytostatic activity on the L1210 mouse leukemia in comparison to clinically used nitrosoureas. Initial experiments showed advantages of the i.v. route for tumor inoculation. Therefore, the anatomical generalisation of tumor cells after i.v. injection was studied by bio-assay. Tumor cell determinations in different organs were 10 to 100 times higher compared with i.p. implantation. Of the new compounds 10 showed marked cytostatic activity in this tumor model by producing cures, and 5 of them must be considered as superior to BCNU, the most commonly used nitrosourea.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00402772
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    N-Nitrosodiethanolamine is activated in the rat to an ultimate genotoxic metabolite by sulfotransferase (1986)
    Springer
    Journal of cancer research and clinical oncology 111 (1986), S. 20-24 
    Details
    ISSN: 1432-1335
    Keywords: N-Nitrosodiethanolamine ; N-Nitroso-2-hydroxymorpholine ; N-Nitrosoethylethanolamine ; Genotoxicity inhibition-Sulfate conjugation-DCNP
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Inhibition of sulfotransferase by 2,6-dichloro-4-nitrophenol (DCNP) has been found to completely abolish the genotoxic potential of N-nitrosodiethanolamine (NDELA) in rat liver as indicated by induction of DNA single strand breaks. The DNA strand breaking potential of N-nitroso-2-hydroxymorpholine (NHMOR), a metabolite of NDELA formed by alcohol dehydrogenase-mediated oxidation, was also almost quantitatively abolished. In contrast to these β-hydroxylated nitrosamines, the effectiveness of N-nitrosodiethylamine (NDEA) remained unaffected by DCNP with respect to its DNA damaging potential. N-Nitrosoethylethanolamine (NEELA) was the most potent genotoxic agent of this series of nitrosamines and its strand breaking activity was only partialy inhibited by DCNP. A new activation mechanism for NDELA is proposed: NDELA is transformed at first by alcohol dehydrogenase into the cyclic hemiacetal NHMOR. This cyclic β-hydroxynitrosamine appears to be a substrate for sulfotransferase. The resulting sulfate conjugate is suggested to be the ultimate genotoxic electrophile. However, the results do not exclude the possiblity that NDELA itself undergoes sulfate conjugation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00402770
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    8th International AEK Symposium of the Division of Experimental Cancer Research of the German Cancer Society (1995)
    Springer
    Journal of cancer research and clinical oncology 121 (1995), S. 683-690 
    Details
    ISSN: 1432-1335
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01218527
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Biological activity of N-nitrosodiethanolamine and of potential metabolites which may arise after activation by alcohol dehydrogenase in Salmonella typhimurium, in mammalian cells, and in vivo (1986)
    Springer
    Journal of cancer research and clinical oncology 111 (1986), S. 149-153 
    Details
    ISSN: 1432-1335
    Keywords: N-Nitrosodiethanolamine ; Genotoxicity ; Alcohol dehydrogenase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The potent carcinogen N-nitrosodiethanolamine (NDELA) which is nonmutagenic in standard modifications of the S. typhimurium/mammalian microsome assay, can be activated effectively by alcohol dehydrogenase/NAD (ADH/NAD) to intermediates which are directly mutagenic in strains TA 98 and TA 100. The expected metabolites N-nitroso-2-hydroxymorpholine (NHMor), N-nitroso-(2-hydroxyethyl)-glycine (NHEG), N-nitrosoiminodiacetic acid (NIDA), and glycolaldehyde were assayed for their direct mutagenic activities in S. typhimurium TA 1535, TA 98, and TA 100. All compounds were clearly mutagenic in TA 100, but different specifities were observed for the other strains. NDELA and its putative mutagenic metabolites were also tested for induction of genotoxic activities by determination of DNA single strand breaks in primary rat hepatocytes. In these cells, NDELA and NHMor were clearly genotoxic, whereas NHEG and NIDA were inactive. In contrast, when assayed for the induction of selective DNA amplification NDELA and its metabolites were not found to induce SV40 DNA synthesis in SV40-transformed Chinese Hamster cells. The compounds were also assayed for induction of DNA single strand breaks in the liver after a single oral application to rats. NDELA and NHMor were about equally active in this in vivo test, whereas NHEG, NIDA and glycolaldehyde were inactive. Differences in biological activity in the cultivated cells, as compared to hepatocytes or to the in vivo situation may most probably be due to differences in metabolism and/or pharmacokinetics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00400754
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Increased mutagenicity of N-nitrosodiethanolamine in human lymphocyte cultures after activation by alcohol dehydrogenase (1989)
    Springer
    Journal of cancer research and clinical oncology 115 (1989), S. 445-448 
    Details
    ISSN: 1432-1335
    Keywords: NDELA mutagenicity ; Human lymphocytes ; Alcohol dehydrogenase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The effect of alcohol dehydrogenase (ADH/NAD) from yeast and horse liver was tested on the induction of chromosomal mutations and sister chromatid exchanges (SCE) by N-nitrosodiethanolamine (NDELA) in human lymphocyte cultures. BrdUrd (27 μg) was added 24 h after starting the cultures to allow visualisation of SCE. ADH/NAD and NDELA were added 24 h later in different concentrations. No significantly higher level of numerical or structural chromosome aberrations was observed. However, the SCE frequency per cell was significantly increased by adding NAD (31.25 μmol and 62.5 μmol). The exclusive addition of 220 units ADH from yeast as well as 1.8 units ADH from horse liver also raised the number of SCE highly significantly. The combination of NAD and ADH was more effective than each substances alone in the yeast but not in the horse liver system. NDELA in a range of 12.5–62.5 μmol, given to cultures with ADH/NAD from yeast, additionally increased the SCE frequencies in a dose-dependent way. Similar results were found in cultures containing ADH/NAD from horse liver and 6.25–31.25 μmol NDELA, but the total numbers of SCE were distinctly higher. These results indicate that NDELA is strongly activated by ADH from yeast but even more by ADH from horse liver.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00393334
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Scientific Proceedings Fifth Symposium of the Section of Experimental Cancer Research (SEK) of the German Cancer Society (1989)
    Springer
    Journal of cancer research and clinical oncology 115 (1989), S. S5 
    Details
    ISSN: 1432-1335
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00587529
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    151. Kann durch die proximal-gastrale Vagotomie die Carcinomgefährdung des operierten Magens im Vergleich zur Magenresektion reduziert werden. Ergebnisse des Nitratbelastungstestes (1985)
    Springer
    Langenbeck's archives of surgery 366 (1985), S. 608-608 
    Details
    ISSN: 1435-2451
    Keywords: Operative procedures in ulcer surgery ; Nitrate exposure test ; Risk of carcinoma ; Operationsverfahren in der Ulcus-Chirurgie ; Nitratbelastung ; Carcinomgefähr-dung
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Zur Abschätzung des Carcinomrisikos bei magenoperierten Patienten (B I, B II, PGV) wurde ein Nitratbelastungstest durchgeführt: Bei 12 Patienten nach PGV, BI und BII (Orale Belastung 200 mg Nitrat) wurden Magensaftproben 30, 90 und 240 min hinsichtlich intragastraler Nitritkonzentrationen analysiert und mit 12 Kontrollen verglichen. Bereits nach 30 min zeigte sich ein Anstieg der Medianen Nitritkonzentration bei den Gruppen BI (7,5 ppm) und BII (14,1 ppm). Der Anstieg bei diesen Gruppen lag zu allen Zeiten signifikant (p 0,005) über PGV und Kontrollgruppe. Aus der niedrigen Nitritkonzentration nach PGV schließen wir, daß dieses OP-Verfahren bei dem Faktor der Nitritbildung ein geringeres Carcinomrisiko im Vergleich zur B I und B II-Magenresektion darstellt.
    Notes: Summary To estimate the risk of carcinoma in patients after gastric surgery (Billroth I, II, proximal gastric vagotomy), a nitrate exposure test was carried out (before the operation and 30, 90, and 240 min after oral exposure to 200 mg nitrate) for intragastric nitrite concentration. Twelve healthy subjects served as controls. The median nitrite concentration showed an increase in the B-I (7.5 ppm) and B-II (14.1 ppm) groups in contrast to the PGV and control groups. Since PGV showed lower nitrite concentration, we conclude that, concerning nitrite formation, this procedure has less risk of developing carcinoma in comparison to B-I and B-II resection.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01836750
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Brain uptake and CNS levels of 1-(2-chloroethyl)-1-nitroso-3-(2-hydroxyethyl)urea (HECNU) (1987)
    Springer
    Investigational new drugs 5 (1987), S. 361-364 
    Details
    ISSN: 1573-0646
    Keywords: 1-(2-chloroethyl)-1-nitroso-3(2-hydroxyethyl)urea (HECNU) ; blood brain barrier ; cerebrospinal fluid concentration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Abstract The uptake of 14C-labeled 1-(2-chloroethyl)-1-nitroso-3-(2-hydroxyethyl) urea (HECNU) into the brain was investigated in the rat after intracarotid injection according to the method of OLDENDORF, as well as in cisternal cerebrospinal fluid obtained by suboccipital puncture after i.v. injection of the drug. The brain uptake index was 31.9 ± 2.9%. Cerebrospinal fluid/blood quotients after i.v. injection were 0.82 at 10 min and 1.10 at 60 min. The results of both methods clearly show that HECNU, in spite of its hydrophilic property, easily penetrates the blood-brain barrier.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00169975
    Library Location Call Number Volume/Issue/Year 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...