Effects of 5-aminolaevulinic acid on human ovarian cancer cells and human vascular endothelial cells in vitro.

Results are reported on the cellular effects and the sensitivity of cultured tumor epithelial cells (TEC) derived from human ovarian cystadenocarcinoma and human umbilical vein-derived endothelial cells (HUVEC) to exogenous 5-aminolaevulinic acid (ALA) and ALA-induced photodynamic therapy (PDT). Cellular alterations and PDT efficiency were evaluated using colorimetric thiazolyl blue (MTT) assay, trypan blue exclusion assay, electron microscopy, and gel electrophoresis. ALA-induced protoporphyrin IX (PpIX) accumulation in TEC was associated with a concentration and time-dependent significant decrease in mitochondrial activity, increase in cell membrane permeability, and dark toxicity. Maximum PpIX loaded TEC demonstrated a high sensitivity to PDT. Neither cellular alterations nor PDT effects were observed in HUVEC under identical experimental conditions. These results indicate a potential clinical value for the use of ALA-mediated PDT to treat minimal residual disease in mucinous ovarian carcinoma. In addition, the ALA-induced PpIX cytotoxicity may be exported to a new chemotherapeutic regimen via a conventionally viewed photochemotherapeutic agent.     

Ueber die Bestimmung des Extractes im Weine nach der indirecten Methode

Ohne Zusammenfassung     

REVIEW: metal complexes as urease inhibitors

Urease plays a significant role in the pathogenesis of several diseases and also has practical implications in other fields, such as agriculture or chemical analysis. Among the multitude of chemical species known to inhibit urease, metal complexes stand out as a special category due to their specific mechanism of action, distinct from purely organic substances. Their inhibitory activity seems to depend on the type of metal and its oxidation state as well as on the coordination environment of the central atom. Furthermore, the study of the interaction between metal ions and their complexes with urease renders valuable insights into detailed catalytic mechanisms of this enzyme. This brief survey attempts to provide an overview of the published research on urease inhibition by metal complexes.     

Experimental investigation of the muon transfer reaction from deuterium to helium isotopes

Muon transfer from the ground state of muonic deuterium to a helium atom proceeds mainly via the formation of a muonic molecule in an excited state. A large number of decay X rays ( 6.8 keV) from these (dµHe)^* molecules were observed for the⁴He as well as for the³He case. The time distributions of these X rays allow the determination of the ground state transfer rate. The simultaneous employment of Ge/Si-detectors and CCDs for the same target conditions allows the determination of the branching ratio of radiative to nonradiative decay for the first time.     

Precision measurement of nuclear muon capture by3He

In this article we report the results of an experiment performed in 1993 at PSI. The goal was to determine the absolute rate of nuclear muon capture by³He. In the experiment we used a new technique recently developed at Gatchina. As a preliminary result from this experiment we obtained _c=(1496±3(stat)-3(syst)) s^–1.     

Magnetische Nichtäquivalenz von Methylenprotonen in Metallocenen

Zusammenfassung In den NMR-Spektren von etwa 20 Cymantren-und Ferrocenderivaten wurde magnetische Nichtäquivalenz (MNÄ) von Methylenprotonen beobachtet. Im Gegensatz zu Ferrocenen, woMNÄ bisher nur in -disubstituierten Verbindungen gefunden wurde, tritt ein solcher Effekt bei Cymantrenen auch in einzelnen -disubstituierten Derivaten auf. Durch Tieftemperatur-NMR-Spektren (bei-60°C) einiger Substanzen wurden weitere Hinweise auf Unterschiede in der konformativen Beweglichkeit von Ferrocenen und Cymantrenen gewonnen. Verbindungen mit C=O-Gruppen zeigen besonders starkeMNÄ-Effekte. Die Möglichkeiten zur Anwendung derMNÄ auf Probleme bevorzugter Konformationen und zur Konstitutionszuordnung von Isomeren werden diskutiert.

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Magnetic non-equivalence of methylene protons in metallocenes (cymantrenes, VIII.) ferrocene derivatives, XLIII.)

The NMR spectra of about 20 derivatives of cymantrene and ferrocene were found to show magnetic non-equivalence (MNÄ) of methylene protons. This phenomenon, in ferrocenes hitherto observed only in the spectra of -disubstituted compounds, occurs in cymantrenes also in some -disubstituted derivatives. Recording of low temperature NMR spectra (at-60°C) of several compounds provided additional information as to different conformational mobilities in ferrocenes and cymantrenes. Compounds containing C=O groups show particularly large differences in the chemical shifts of methylene protons. The possibilities of employingMNÄ for problems of preferred conformations and for structural assignments of isomers are discussed.

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Mit 6 Abbildung

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Diese Arbeit zählen wir als 8. Mitt. über Cymantrenderivate und 43. Mitt. über Ferrocenderivate.

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7. Mitt. über Cymantrenderivate:H. Egger undA. Nikiforov, Mh. Chem.99, 2311 (1968); 42. Mitt. über Ferrocenderivate:K. Bauer, H. Falk undK. Schlögl, Mh. Chem.99, 2186 (1968).