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Trametes spec. laccase (EC 1.10.3.2.) mediates the oxidative coupling of 6-aminopenicillanic, 7-aminocephalosporanic, and 7-aminodesacetoxycephalosporanic acid with 2,5-dihydroxybenzoic acid derivatives to form new penicillin and cephalosporin structures, respectively. The heteromolecular hybrid dimers are formed by nuclear amination of the p-hydroquinones with the primary amines and inhibited in vitro the growth of Staphylococcus species, including some multidrug-resistant strains.

In order to design potential biomaterials, we investigated the laccase-catalyzed cross-linking between L-lysine or lysine-containing peptides and dihydroxylated aromatics. L-Lysine is one of the major components of naturally occurring mussel adhesive proteins (MAPs). Dihydroxylated aromatics are structurally related to 3,4-dihydroxyphenyl-L-alanine, another main component of MAPs. Mass spectrometry and nuclear magnetic resonance analyses show that the epsilon-amino group of L-lysine is able to cross-link dihydroxylated aromatics. Additional oligomer and polymer cross-linked products were obtained from di- and oligopeptides containing L-lysine. Potential applications in medicine or industry for biomaterials synthesised via the three component system consisting of the oligopeptide [Tyr-Lys]10, dihydroxylated aromatics and laccase are discussed.

The ability of the imperfect soil fungus Paecilomyces lilacinus to transform the environmental pollutant dibenzofuran was investigated. Transformation of dibenzofuran and related derivatives lead to 14 products, which were identified by UV spectroscopy, mass spectrometry, and proton nuclear magnetic resonance spectroscopy. Biotransformation was initiated by two separate hydroxylation steps, leading to the accumulation of 4-monohydroxylated and 4-dihydroxylateddibenzofurans. Hydroxylation at both aromatic rings produced 2,7-dihydroxydibenzofuran, 3,7-dihydroxydibenzofuran, and 2,8-dihydroxydibenzofuran. Further oxidation yields ring cleavage of dibenzofuran, which has not been described before for filamentous fungi. The ring fission products were identified as benzo[ b]furo[3,2-d]-2-pyrone-6-carboxylic acid and [2-(1-carboxy-methylidene)-benzofuran-3-ylidene]-hydroxy-acetic acid and its derivatives hydroxylated at carbon 7 and 8 at the non-cleaved ring. Other metabolites were riboside-conjugates of 2-hydroxydibenzofuran and 3-hydroxydibenzofuran. The results showed that P. lilacinus transforms the hydrophobic compound dibenzofuran by phase I/phase II reactions to produce hydroxylated products and excretable sugar conjugates.

Background: Retrospective investigation to identify associations between certain patient characteristics and survival in 531 patients with resected colorectal cancer (CRC). Special reference is given to a standardized comorbidity., Methods: To compare different levels of exposure we determined hazard ratios (HR) in Cox proportional hazards models for survival times and odds ratios (OR) in logistic regression models., Results: Overall survival was associated with tumor stages (III+IV vs. I+II; HR 7.48), tumor differentiation (low vs. high; HR 1.84), blood transfusions (>2 vs. < or =2; HR 1.88), and comorbidity (Charlson Comorbidity Index >2 vs. < or =2; HR 1.77). Low tumor stage (I+II vs. III+IV; OR 11.1), elevated Charlson Comorbidity Index (>2 vs. < or =2; OR 3.83), and longer ICU stay (>2 days vs. < or =2 days; OR 3.40) more frequently lead to non-cancer-related death than to cancer-related death., Conclusion: Standardized comorbidity should be considered as a factor in survival studies of CRC.

Cells of the white rot fungus Pycnoporus cinnabarinus grown in glucose were able to hydroxylate biphenyl and diphenyl ether, although growth was inhibited by these substrates at concentrations above 250 microM. 2- and 4-Hydroxybiphenyl were detected as products of biphenyl metabolism and 2- and 4-hydroxydiphenyl ether as products of diphenyl ether metabolism in the culture media. After addition of 2-hydroxydiphenyl ether and 2-hydroxybiphenyl to cell-free supernatants containing laccase as the only ligninolytic enzyme, different coloured precipitates were formed. HPLC analysis revealed the formation of additional hydrophobic metabolites with one major product per transformation. Mass spectrometric analysis of the methyl derivatives of the polymer mixture indicated dimers and trimers with different binding types. The main products were identified as dimers with carbon-carbon bonds in para-position to the hydroxyl group of the monomers by mass spectroscopy and nuclear magnetic resonance spectroscopy.

Hydroxylation of biphenyl by the dibenzofuran-degrading yeast Trichosporon mucoides SBUG 801 was studied. Glucose-grown cells degraded 40% of the biphenyl added within the first 24 h of incubation. The first step in the biotransformation pathway was the monohydroxylation of the biaryl compound to produce 2-, 3-, and 4-hydroxybiphenyl. Further oxidation produced seven dihydroxylated intermediates; the second hydroxyl group was added either on the aromatic ring already hydroxylated or on the second ring. Of all metabolites, 2,5-dihydroxybiphenyl accumulated in the supernatant in the highest concentration. The initial hydroxylation favors the 4-position to produce 4-hydroxybiphenyl, which is subsequently hydroxylated to form 3,4-dihydroxybiphenyl. When biphenyl was replaced as a substrate by 4-hydroxybiphenyl, further hydroxylation of the intermediate 3,4-dihydroxybiphenyl resulted in 3,4,4'-trihydroxybiphenyl. Incubation of T. mucoides with biphenyl and 18O2 indicated a monooxygenase-catalyzed reaction in the oxidation of biphenyl. The hydroxylation was inhibited by 1-aminobenzotriazole and metyrapone, known cytochrome P450 inhibitors. These results are very similar to those observed in the biotransformation of biphenyl in mammals.

A new CEDIA assay for the measurement of digoxin in serum on random access analyzers was evaluated by twelve laboratories in Europe and the United States. Studies on the analytical range, reproducibility, calibration stability, recovery in controls, interlaboratory comparability, comparability with routine methods, and the effect of various interfering factors have been performed and the results are presented in this paper. The analytical performance was comparable to that of routine methods provided the manual pipetting step for pre-incubation was performed with accurate pipettes. A major advantage of the CEDIA Digoxin assay in terms of convenience is the simple two-point calibration procedure. Moreover, digoxin can be determined within 15 minutes after receiving the samples on random access analyzers like Boehringer Mannheim/Hitachi analysis systems. Thus, the CEDIA Digoxin assay represents an attractive alternative to the measurement of digoxin on dedicated immunochemical assay systems.

We evaluated a CEDIA assay for the determination of digitoxin in serum on random access analyzers. The multicenter evaluation included studies on the analytical range, calibration stability and reproducibility of the new assay. Moreover, recovery in controls, transferability of results obtained in different laboratories, comparability with routine methods, and the effect of various interfering factors have been analyzed. Summarized the analytical performance was comparable to that of routine methods. The CEDIA Digitoxin assay represents an attractive alternative to established digitoxin immunoassays because it can be performed on random access analyzers, thus permitting the simultaneous determination of digitoxin and other serum analytes without sample splitting.