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Introduction: The aim of the present study was to determine the antimicrobial effect of various gel formulations on plaque formation; different tooth gels were compared to a toothpaste containing comparable antimicrobial ingredients with regard to its microbiocidal activity. The study was conducted under the assumption, that a chief requirement for the prevention of plaque formation is the combination of mechanical removal and antimicrobial activity, and not the sole capability of mechanical plaque removal. Methods: Ledermix ® fluoride gel as commercially available with preservative. and without preservative and perfume oils, Elmex® gelée, and Meridol® toothpaste were tested in a standardized in-vitro test modification of the quantitative suspension test EN 1040. Instead of testing in a suspension, the respective product was directly placed on a standardized contaminated sterile stainless steel disk without adding any bio-burden. 50% egg yolk in Aqua dest. was used as a neutralizer. Results: Within 1 min, Elmex® gelée showed a RF >5 log10 against S. pyogenes and S. sanguinis. Against S. mutans, a log10 RF of =5 was achieved after 2 min, against C. albicans after 5 min, and against P. aeruginosa after 10 min S. aureus was the most difficult organisms to be reduced. After an application time of 10 min, only a log10 RF of 2.4 was achieved. Ledermix exceeded the antimicrobial efficacy of Elmex ® gelée against S. mutans and C. albicans and was already effective against these organisms after 1 min, but did not show the same antimicrobial efficacy as Elmex® gelée against P. aeruginosa. Similar to Elmex® gelée, a required reduction of >5 log10 for antimicrobials under no organic challenge was not achieved against S. aureus. Ledermix® fluoride gel without preservatives and Ledermix ® fluoride gel without preservatives and perfume oil did not show the antimicrobial efficacy of the standard Ledermix® fluoride gel formulation, indicating that the observed antimicrobial efficacy is chiefly based on the preservative, and possibly the perfume oil. Compared to the tested gels, Meridol® toothpaste was less effective and reached any antimicrobial effect >5 log10 only against S. sanguinis after 10 min. Conclusion: All unmodified tested gels showed an antimicrobial effect. Because no relevant antimicrobial efficacy against plaque forming bacteria was achieved within 2 min, in practice, an anti-plaque forming effect based on the antimicrobial action of gels cannot be assumed when used in the oral cavity. However, the results of the present study indicate that the antimicrobial efficacy of gels is determined by their formulation and that for the prevention of plaque formation the combination of mechanical removal and antimicrobial activity is not the chief requirement only, but a sustained antimicrobial effect may be of greater importance. [ABSTRACT FROM AUTHOR]

Ceftriaxone, a third-generation cephalosporin, has been reported to occasionally cause fatal drug-induced immune hemolytic anemia (DIHA). A clinical and serologic analysis of the first two patients with severe drug-induced thrombocytopenia (DITP) due to ceftriaxone and one patient with fatal DIHA is reported. Sera were assessed by the IAT, EIA, glycoprotein (GP)-specific immunoassay, flow cytometry, and immunoprecipitation using trans-fectants expressing GPIIb/IIIa and GPIb/IX and with different cephalosporins. Sera from Patients 1 and 2 reacted strongly with PLTs in the presence of the drug, but not with RBCs. The binding sites of the drug-dependent antibodies (DDAbs) could be localized to GPIIb/IIIa and GPIb/IX, respectively. Inhibition studies indicated that DDAbs recognized epitopes residing on the GPIIb/IIIa complex and on the GPIX subunit, respectively. No cross-reactivity was observed with other cephalosporin derivatives. Serum 3 showed strong agglutination with RBCs of Rhnull phenotype in the presence of ex-vivo metabolites of ceftriaxone, but no cross-reactivity with PLTs. The first two cases of severe DITP and a third patient with DIHA are reported. DDAbs from all patients showed individual reaction patterns and clear cell lineage specificity. In addition, the DDAbs were dependent on the substitution at position 3 of the ceftriaxone molecule. Epitopes on GPIIb/IIIa and GPIX were involved on PLTs. The Rh protein was not the only target of DDAbs on RBCs. [ABSTRACT FROM AUTHOR]

The principle of a patient-specific immunoadsorber (PsIA) is demonstrated. Studies with model systems (HSA/anti-HSA) on immobilization, stability, and leakage form the basis for the presented fast-performance liquid chromatography (FPLC) and batch experiments, which were conducted using two different protein A adsorbers and autologous and heterologous PsIA systems. Experiments to determine the binding capacity of protein A adsorbers and PsIAs are described. In all experiments, the adsorption of plasma IgG, total protein, and C1q and C3d circulating immune complexes were measured. Plasma of patients with autoimmune diseases (rheumatoid arthritis, systemic lupus erythematosus) was investigated. Analysis was performed in both the initial plasma and the flow-through or supernatant. Results of the investigations using FPLC and batch experiments were compared. Autologous PsIA systems are suitable for the selective removal of elevated levels of circulating immune complexes in the plasma. [ABSTRACT FROM AUTHOR]

Wir haben die P450‐Monooxygenase CYP107D1 (OleP) aus Streptomyces antibioticus für die stereo‐ und regioselektive 7β‐Hydroxylierung von Lithocholsäure (LCS) zur Herstellung von Ursodeoxycholsäure (UDCS) durch "Protein‐Engineering" angepasst. OleP wurde zuvor für die Hydroxylierung von Testosteron an der 7β‐Position beschrieben, hydroxyliert jedoch LCS ausschließlich an der 6β‐Position, wodurch Murideoxycholsäure (MDCS) gebildet wird. Struktur‐ und 3DM‐Analysen, sowie molekulare Modellierungen wurden verwendet, um die Aminosäurereste F84, S240 und V291 als spezifitätsbestimmend zu identifizieren. Durch einen Alaninscan wurde S240A als UDCS‐produzierende Variante identifiziert. Basierend auf den identifizierten Positionen wurde eine synthetische "small but smart" Bibliothek durch die Verwendung eines farbbasierten Assays auf UDCS Produktion getestet. Hier konnte eine beinahe perfekte regio‐ und stereoselektive Dreifachvariante (F84Q/S240A/V291G) identifiziert werden, die UDCS in einer 10‐fach höheren Menge produziert als die S240A Variante. Der hergestellte Biokatalysator eröffnet neue Möglichkeiten zur umweltfreundlichen Synthese von UDCS aus dem Abfallprodukt LCS. [ABSTRACT FROM AUTHOR]

We engineered the cytochrome P450 monooxygenase CYP107D1 (OleP) from Streptomyces antibioticus for the stereo‐ and regioselective 7β‐hydroxylation of lithocholic acid (LCA) to yield ursodeoxycholic acid (UDCA). OleP was previously shown to hydroxylate testosterone at the 7β‐position but LCA is exclusively hydroxylated at the 6β‐position, forming murideoxycholic acid (MDCA). Structural and 3DM analysis, and molecular docking were used to identify amino acid residues F84, S240, and V291 as specificity‐determining residues. Alanine scanning identified S240A as a UDCA‐producing variant. A synthetic "small but smart" library based on these positions was screened using a colorimetric assay for UDCA. We identified a nearly perfectly regio‐ and stereoselective triple mutant (F84Q/S240A/V291G) that produces 10‐fold higher levels of UDCA than the S240A variant. This biocatalyst opens up new possibilities for the environmentally friendly synthesis of UDCA from the biological waste product LCA. [ABSTRACT FROM AUTHOR]