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  • 1
    Electronic Resource
    Electronic Resource
    Polymer/metal interfaces studied by carbon near-edge x-ray absorption fine structure spectroscopy (1988)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 89 (1988), S. 2482-2489 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Interaction of polyimide and two simple organic polymers with an evaporated chromium metal overlayer was studied by surface-sensitive carbon 1s near-edge x-ray absorption fine structure (NEXAFS) spectroscopy. The technique was used to measure unoccupied electronic states in the polymers. Assignments of C1s→π* transitions in poly(pyromellitimido oxydianiline) (PMDA-ODA polyimide) were based upon transitions measured for model polymers which contained structural subunits of the polyimide. Changes in the NEXAFS spectrum of each polymer were observed after sequential depositions of chromium. Abrupt changes in the carbonyl C1s→π* transition peaks show that the carbonyl groups on these polymers are sites for initial interaction with chromium. No evidence was seen for the formation of Cr–arene complexes on any of the polymer surfaces.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.455042
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  • 2
    Electronic Resource
    Electronic Resource
    Activity and properties of CTP: Cholinephosphate cytidylyltransferase in adult and fetal rat lung
    Amsterdam : Elsevier
    Biochimica et Biophysica Acta (BBA)/Lipids and Lipid Metabolism 441 (1976), S. 280-293 
    Details
    ISSN: 0005-2760
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Biology , Chemistry and Pharmacology , Medicine , Physics
    Type of Medium: Electronic Resource
    URL: http://linkinghub.elsevier.com/retrieve/pii/0005-2760(76)90171-5
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  • 3
    Electronic Resource
    Electronic Resource
    Induction of oocyte maturation by jun-N-terminal kinase (JNK) on the oncogenic ras-p21 pathway is dependent on the raf-MEK-MAP kinase signal transduction pathway (2000)
    Springer
    Cancer chemotherapy and pharmacology 45 (2000), S. 441-449 
    Details
    ISSN: 1432-0843
    Keywords: Key words Oncogenic ras-p21 ; Oocyte maturation ; Dominant negative mutant of raf
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Purpose: We have previously found that microinjection of activated MEK (mitogen activated kinase kinase) and ERK (mitogen-activated protein; MAP kinase) fails to induce oocyte maturation, but that maturation, induced by oncogenic ras-p21 and insulin-activated cell ras-p21, is blocked by peptides from the ras-binding domain of raf. We also found that jun kinase (JNK), on the stress-activated protein (SAP) pathway, which is critical to the oncogenic ras-p21 signal transduction pathway, is a strong inducer of oocyte maturation. Our purpose in this study was to determine the role of the raf-MEK-MAP kinase pathway in oocyte maturation and how it interacts with JNK from the SAP pathway. Methods: We microinjected raf dominant negative mutant mRNA (DN-raf) and the MAP kinase-specific phosphatase, MKP-T4, either together with oncogenic p21 or c-raf mRNA, into oocytes or into oocytes incubated with insulin to determine the effects of these raf-MEK-MAP kinase pathway inhibitors. Results: We found that oocyte maturation induced by both oncogenic and activated normal p21 is inhibited by both DN-raf and by MKP-T4. The latter more strongly blocks the oncogenic pathway. Also an mRNA encoding a constitutively activated MEK strongly induces oocyte maturation that is not inhibited by DN-raf or by MKP-T4. Surprisingly, we found that oocyte maturation induced by JNK is blocked both by DN-raf and MKP-T4. Furthermore, we discovered that c-raf induces oocyte maturation that is inhibited by glutathione-S-transferase (GST), which we have found to be a potent and selective inhibitor of JNK. Conclusion: We conclude that there is a strong reciprocal interaction between the SAP pathway involving JNK and the raf-MEK-MAP kinase pathway and that oncogenic ras-p21 can be preferentially inhibited by MAP kinase inhibitors. The results imply that blockade of both MAP kinase and JNK-oncogenic ras-p21 interactions may constitute selective synergistic combination chemotherapy against oncogenic ras- induced tumors.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002800051017
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  • 4
    Electronic Resource
    Electronic Resource
    Selective advantage of fra (X) heterozygotes (1990)
    Springer
    Human genetics 〈Berlin〉 86 (1990), S. 25-32 
    Details
    ISSN: 1432-1203
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The high incidence of the fra (X) syndrome (about 1∶2000 male newborns) requires an explanation in view of the low fitness of mentally retarded hemizygous males and heterozygous females. In the past, it has been proposed that the mutation rate may be unusually high, and that mutations occur exclusively in male germ cells. According to an alternative hypothesis, a moderately high mutation rate might combine with a selective advantage of clinically unaffected heterozygotes. In earlier studies, such a combined hypothesis was shown to lead to plausible implications regarding mutation rate and fitness. Moreover, a mutation rate in male germ cells of the magnitude required by the exclusive mutation hypothesis was excluded by studies on comprehensive pedigree data. In this third study in the series, an increased fitness of heterozygous females is demonstrated directly by a comparison of the reproductive performance of heterozygotes with that of adequate controls (mothers and grandparents of Down's syndrome patients). Since average numbers of children have decreased during recent decades in populations of industrialized countries, heterozygotes (mothers of affected probands and their female relatives in their own generation) were subdivided into those born before and after 1940. Moreover, sibship sizes of probands' mothers and fathers were analyzed separately for family branches in which the fra (X) trait segregated (mostly the maternal branch), or did not segregate (in most instances the paternal branch). In all four categories reproductive performance in heterozygotes was found to be higher than in the controls. This difference was significant statistically for two of the four groups: it was small and nonsignificant only for the parental family branch in which the fra (X) mutant did not segregate and for mothers born after 1940. Fitness estimates ranged between 1.11 and 1.36. A higher incidence of dizygotic twinning suggests a biological component for this increased fertility. On the other hand, fra (X) families have a significantly lower social status than the controls. This suggests a socio-psychological component of their higher fertility. Apparently, both components contribute to their fertility: at present, their relative importance cannot be assessed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00205167
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  • 5
    Electronic Resource
    Electronic Resource
    Microheterogeneity of acute phase proteins in patients with clinically active and clinically nonactive osteoarthritis (1995)
    Springer
    Clinical rheumatology 14 (1995), S. 434-440 
    Details
    ISSN: 1434-9949
    Keywords: Microheterogeneity ; α-1-acid ; Glycoprotein ; α-1-antichymotrypsin ; Cytokines ; Osteoarthritis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Microheterogeneity of two acute phase glycoproteins, α-1-acid glycoprotein (AGP) and α-1-antichymotryspin (ACT), concentrations of AGP, ACT, and C-reactive protein (CRP), and levels of three cytokines: interleukin 1 β (IL-1-β), interleukin 6 (IL-6), and tumor necrosis factor α (TNF-α) were determined in 61 serum samples and 7 synovial fluids (SFs) obtained from patients (n=61) with osteoarthritis. Using affinity immunoelectrophoresis with concanavalin A (conA), a significant decrease in the reactivity of AGP and ACT with this lectin was found in patients with clinically active osteoarthritis when compared to those with clinically nonactive disease (p〈0.001 and p〈0.05, respectively). There was no increase in the concentration of AGP, ACT, and C-reactive protein (CRP) in the sera examined. In particular, no increase in the serum level of these proteins was found in the patients with clinically active disease. Low concentrations of IL-6 and TNF-α were found in most sera and SFs examined. In 6 out of 7 SFs available, IL-6 concentrations were higher than in the respective serum samples but for TNF-α the same could be shown in one case only. Low concentrations of IL-1-β were found in 4 serum samples obtained from patients with clinically active osteoarthritis and in no SF specimen studied. In the entire group, serum level of TNF-α correlated weakly with the AGP and ACT reactivity coefficients with conA (r=0.3634, p〈0.005 and r=0.3324, p〈0.02, respectively). Our findings suggest that there are changes in the microheterogeneity of acute phase glycoproteins in some patients with osteoarthritis similar to those observed in rheumatoid arthritis and other chronic inflammations. Possible mechanisms of the involvement of cytokines in the regulation of glycosylation of acute phase glycoproteins in osteoarthritis are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02207678
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