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  • Articles: DFG German National Licenses  (8)
  • Electronic Resource  (8)
  • Pleuromutilin  (4)
  • Effusions  (2)
  • Kleiner Feldberg  (2)
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  • Articles: DFG German National Licenses  (8)
Material
  • Electronic Resource  (8)
  • 1
    ISSN: 1432-2307
    Keywords: Key words Adenocarcinoma cell ; Mesothelial cells ; Effusions ; Immunohistochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  The detection of malignant cells in serous effusions obtained from patients diagnosed with cancer marks the presence of metastatic disease and is associated with a poor outcome. The purpose of this study was to evaluate the role of CD44s and CD44v isoforms in the distinction between mesothelial cells and malignant epithelial cells in effusions. Fifty-nine fresh pleural and peritoneal effusions were studied. These consisted of 41 specimens from patients with known gynecological neoplasms, 9 from patients diagnosed with breast adenocarcinoma, and 9 effusions from patients with various nongynecological malignancies or tumors of unknown origin. Forty-three effusions contained malignant/atypical epithelial cells, and 16 effusions were diagnosed as reactive. Three effusions contained exclusively malignant cells. Specimens were stained with anti-CD44s, v3, v5, v6, v7 and v3-10. The presence of staining in cancer cells, benign mesothelial cells and lymphocytes was evaluated. CD44s immunoreactivity was seen in 10 of 43 (23%) cases in malignant/atypical epithelial cells and in 53 of 56 (94%) cases in benign cells. In contrast, CD44v3-10 was seen in 23 of 43 (55%) cases in malignant/atypical epithelial cells and in 3 of 56 (6%) cases in benign cells. We advocate the use of CD44s and CD44v3-10 immunostaining in diagnostic evaluation of difficult serous effusions.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Monatshefte für Chemie 112 (1981), S. 1441-1450 
    ISSN: 1434-4475
    Keywords: Contraction of ring A ; Photo-Wolff-rearrangement ; Pleuromutilin ; Tricyclic diterpene
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Derivatives of the antibiotic pleuromutilin are rapidly metabolised in animals. This phenomenon is responsible for the lack of biological activity of these compoundsin vivo although their activitiesin vitro are extremely high (MHK=0,005–0.1 μg/ml). In order to reduce the rate of metabolism a compound with slightly modified conformation (15) in the appropriate region of the molecule (C-1, C-2)3a was chosen for biological tests. The synthesis of this compound is described in detail.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 1434-4475
    Keywords: Pleuromutilin ; Inversion of configuration ; 1,5-Hydride-shift
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The contact of pleuromutilin derivatives with the protein moiety of cytochrome P-450 as well as its orientation towards the heme iron is mainly dependent on the steric environment of the hydrindanone-part of the tricyclus. The apparent affinity between substrate and enzyme, which is correlated with the rate of metabolism can be reduced by inversion of configuration at carbon 6. This inversion is achieved by equilibrating the diastereomeric ketones12 and13 followed by a selective reduction of the keto group at position 7. The 6-methylgroup of14 was assigned α-configuration on the basis of spectroscopic data in comparison to those of the naturally configurated compound14a.
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 1434-4475
    Keywords: Pleuromutilin ; Ketol-isomerization ; 11,2-Hydride-shift ; 1,2-Carbonyl-transposition ; Photoaddition to enones
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract 2-Hydroxy-19,20-dihydropleuromutilin (10) undergoes a stereospecific ketolisomerisation when treated with base under phase/transfer conditions (11, 12). The subsequent reductive elimination of the 3-acetoxygroup afforded mutilin with a 1,2-transposed ketofunction (13).
    Type of Medium: Electronic Resource
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  • 5
    ISSN: 1434-4475
    Keywords: Pleuromutilin ; Inversion of configuration ; Reversible retro-en-cleavage ; Simmons-Smith-reaction ; Type I-“metallo-en”-reaction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The reaction of pleuromutilin-22-0-tosylat(2) withEtZnI afforded a mixture of the 12-epimeric compounds2 and3. A reversible retro-en-reaction of the homoallylic system is discussed as a possible mechanistic pathway. The structure assignment is based on1H- and13C-NMR spectroscopic data.
    Type of Medium: Electronic Resource
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  • 6
    ISSN: 1432-2307
    Keywords: Key words Gynaecological cancers ; Effusions ; Epithelial markers ; Immunocytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  The detection of malignant cells in pleural, peritoneal, and pericardial fluids of cancer patients marks the presence of metastatic disease and is associated with a grave prognosis. We evaluated five epithelial markers for the detection of cancer cells in 94 fresh pleural, peritoneal and pericardial effusions. Eighty-four of the samples were regarded as adequate for analysis after evaluation of cytological smears, including 61 samples from patients known to have gynaecological neoplasms. The other 23 samples were from patients with various non-gynaecological malignancies or tumours of unknown origin. Our control cases were 10 fallopian tubes not affected by any malignancy and 12 malignant mesotheliomas. Cell blocks from all cases were stained for CA-125, BerEP4, carcinoembryonic antigen (CEA), BG8 (Lewis Y blood antigen), and B72.3 (TAG-72). Fifty-one of 84 cases were diagnosed as malignant or suggestive of malignancy in cytological smears and/or cell block sections. However, staining for epithelial markers highlighted the presence of malignant cells in 7 additional cases. When membrane staining was evaluated, the sensitivity of the markers studied in detecting malignant cells was as follows: CA-125: 88%, BerEP4: 78%, CEA: 26%, BG8: 86%, B72.3: 79%. Membrane positivity for CEA, B72.3 and BerEP4 was not detected in reactive mesothelial cells. However, membranous staining in mesothelial cells was evident in 13% and 31% of cases with the use of BG8 and CA-125, respectively. Weak cytoplasmic staining for CEA was observed in mesothelial cells in 2 cases. When Ber-EP4, B72.3, and BG8 staining results in cancer cells were combined, the following sensitivity levels were observed: BG8+B72.3: 91%; BG8+Ber-EP4: 90%; B72.3+Ber-EP4: 93%; BG8+ Ber-EP4+B72.3: 95%. The detection of malignant cells in effusions is facilitated by the use of immunocytochemistry using a wide panel of antibodies. BerEP4 and B72.3 appear to be the best markers when both sensitivity and specificity are considered, followed by BG8, while CEA and CA-125 have a limited role in the detection of metastases from gynaecological tumours owing to the low sensitivity of the former and the low specificity of the latter. Analysis of all staining results should be based on a thorough morphological examination.
    Type of Medium: Electronic Resource
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  • 7
    ISSN: 1573-0662
    Keywords: Atmospheric multiphase system ; atmospheric acidity ; cloud chemistry ; cloud acidity ; phase-partitioning ; Kleiner Feldberg
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Geosciences
    Notes: Abstract The chemistry of cloud multiphase systems was studied within the Kleiner Feldberg Cloud Experiment 1990. The clouds encountered during this experimental campaign could be divided into two categories according to the origin of air masses in which the clouds formed. From the chemical point of view, clouds passing the sampling site during the first period of the campaign (26 October-4 November) were characterized by lower pollutant loading and higher pH, as compared to clouds during the final period of the experimental campaign (10–13 November). The study of multiphase partitioning of the main chemical constituents of the cloud systems and of atmospheric acidity within the multiphase systems themselves (gas + interstitial aerosol + liquid droplets) are presented in this paper. A general lack of gaseous NH3 was found in these cloud systems, which caused a lack of buffer capacity toward acid addition. Evidence supports the hypothesis that the higher acidity of the cloud systems during this final period of the campaign was due to input of HNO3. Our measurements, however, could not determine whether the observed input was due to scavenging of gaseous HNO3 from the air feeding into the cloud, or to heterogeneous HNO3 formation via NO2 oxidation by O3 to NO3 and N2O5. Sulfate in cloud droplets mainly originated from aerosol SO 4 2− scavenging, since S(IV) to S(VI) liquid phase conversion was inhibited due to both lack of H2O2 and low pH of cloud droplets, which made O3 and metal catalyzed S(IV) oxidation inefficient.
    Type of Medium: Electronic Resource
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  • 8
    ISSN: 1573-0662
    Keywords: Cloud model ; airflow model ; cloud chemistry ; cloud microphysics ; aerosols ; Henry's Law ; nitric acid ; cloud-water acidity ; turbulence ; mixing ; scavenging ; Kleiner Feldberg ; GCE
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Geosciences
    Notes: Abstract The airflow, cloud microphysics and gas- and aqueous-phase chemistry on Kleiner Feldberg have been modelled for the case study of the evening of 1 November 1990, in order to calculate parameters that are not easily measured in the cloud and thus to aid the interpretation of the GCE experimental data-set. An airflow model has been used to produce the updraught over complex terrain for the cloud model, with some care required to ensure realistic modelling of the strong stable stratification of the atmosphere. An extensive set of measurements has been made self-consistent and used to calculate gas and aerosol input parameters for the model. A typical run of the cloud model has calculated a peak supersaturation of 0.55% which occurs about 20 s after entering cloud where the updraught is 0.6 m s−1. This figure has been used to calculate the efficiency with which aerosol particles were scavenged; it is higher than that calculated by other methods, and produces a cloud with slightly too many droplets. A broad cloud droplet size spectrum has been produced by varying the model inputs to simulate turbulent mixing and fluctuations in cloud parameters in space and time, and the ability of mixing processes near cloud-base to produce a lower peak supersaturation is discussed. The scavenging of soluble gases by cloud droplets has been observed and departures from Henry's Law in bulk cloud-water samples seen to be caused by variation of pH across the droplet spectrum and the inability of diffusion to adjust initial distributions of highly soluble substances across the spectrum in the time available. Aqueous-phase chemistry has been found to play a minor role in the cloud as modelled, but circumstances in which these processes would be more important are identified.
    Type of Medium: Electronic Resource
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