Impact of mono- and poly-ester fractions on polysorbate quantitation using mixed-mode HPLC-CAD/ELSD and the fluorescence micelle assay.

Determination of excipient content in drug formulation is an important aspect of pharmaceutical formulation development and for analytical testing of the formulation. In this study, the influence of polysorbate subspecies, in particular mono- and poly-esters, for determining polysorbate (PS) content were investigated by comparing three of the most widely used PS quantitation approaches, the Fluorescence Micelle Assay (FMA) and Mixed-Mode High Performance Liquid Chromatography coupled with Charged Aerosol Detection (MM-CAD) or Evaporative Light Scattering Detection (MM-ELSD). FMA and MM-CAD were employed to investigate the quantitation behavior of PS20 and PS80 subspecies and corresponding degradation products in placebo formulations using forced degradation conditions at 40°C for up to 12 weeks.

The immunogenicity of antibody aggregates in a novel transgenic mouse model.

Purpose: Protein aggregates have been discussed as a potential risk factor related to immunogenicity. Here we developed a novel human IgG transgenic (tg) mouse system expressing a mini-repertoire of human IgG1 antibodies (Abs) for the assessment of immunogenic properties of human mAb preparations.

Methods: Transgenic mice were generated using germline versions of the human Ig heavy chain γ1 (IgH-γ1), and the human Ig light chain (IgL) κ and λ genes.

Structure and function of purified monoclonal antibody dimers induced by different stress conditions.

Purpose: To investigate structure and function of different monoclonal antibody (MAb) dimers.

Methods: MAb dimers were induced by process-related, low pH and UV light stress. Dimers were isolated and purified by chromatography and extensively characterized by biochemical, structural and functional methods.

The Hershey access clinic: a model for improving patient access.

Background: When waiting times for new and return patient visits at Hershey Medical Center's Department of Dermatology approached 4 and 2 months, respectively, the Hershey access clinic was implemented to increase access for patients with acute problems.

Objective: The purpose of this study was to assess the impact of the Hershey access clinic on patient care.

Results: The great majority of patients were satisfied with the access clinic.

[Paediatric laryngotracheal stenosis: pattern of care in Germany].

Background: Stenoses of the larynx and upper trachea in the pediatric population require a multidisciplinary approach and center-based treatment. Patterns of care and treatment strategies in Germany were evaluated using a standardized questionnaire.

Material And Methods: A questionnaire was transmitted by telefax to 141 departments of Otorhinolaryngology (ORL) and to 214 pediatric (PED) departments.

Infliximab associated new-onset psoriasis.

Infliximab infusion is not yet FDA-approved for psoriasis but has been reported to be very effective for plaque psoriasis. We report 2 patients without a history of psoriasis who after administration of infliximab for their inflammatory bowel disease experienced new onset, biopsy confirmed psoriasis.

Biocatalytic conversion of avermectin to 4"-oxo-avermectin: heterologous expression of the ema1 cytochrome P450 monooxygenase.

The cytochrome P450 monooxygenase Ema1 from Streptomyces tubercidicus R-922 and its homologs from closely related Streptomyces strains are able to catalyze the regioselective oxidation of avermectin into 4"-oxo-avermectin, a key intermediate in the manufacture of the agriculturally important insecticide emamectin benzoate (V. Jungmann, I. Molnár, P.

Biocatalytic conversion of avermectin to 4"-oxo-avermectin: characterization of biocatalytically active bacterial strains and of cytochrome p450 monooxygenase enzymes and their genes.

4"-Oxo-avermectin is a key intermediate in the manufacture of the agriculturally important insecticide emamectin benzoate from the natural product avermectin. Seventeen biocatalytically active Streptomyces strains with the ability to oxidize avermectin to 4"-oxo-avermectin in a regioselective manner have been discovered in a screen of 3,334 microorganisms. The enzymes responsible for this oxidation reaction in these biocatalytically active strains were found to be cytochrome P450 monooxygenases (CYPs) and were termed Ema1 to Ema17.

Cystic basal cell carcinoma or hidrocytoma? The use of an excisional biopsy in a histopathologically challenging case.

Basal cell carcinoma (BCC) has many histologic variants. These variants may show differentiation toward benign and malignant tumors of cutaneous appendages, especially hair follicles. Herein we describe a lesion that was clinically thought to be a BCC, but a superficial biopsy showed histologic features suggestive of an apocrine hidrocystoma.

Discovering new enzymes and metabolic pathways: conversion of succinate to propionate by Escherichia coli.

The Escherichia coli genome encodes seven paralogues of the crotonase (enoyl CoA hydratase) superfamily. Four of these have unknown or uncertain functions; their existence was unknown prior to the completion of the E. coli genome sequencing project.

A base-off analogue of coenzyme-B12 with a modified nucleotide loop--1H-NMR structure analysis and kinetic studies with (R)-methylmalonyl-CoA mutase, glycerol dehydratase, and diol dehydratase.

(Co beta-5'-Deoxyadenosin-5'-yl)-(p-cresolyl)cobamide (Ado-PCC), an analogue of the base-off form of coenzyme-B12 (CoB12), was prepared by alkylation of (Co alpha/beta-cyano/aqua)-(p-cresolyl)cobamide (PCC) with 5'-chloro-5'-deoxyadenosine. The 500 MHz 1H-NMR spectrum of Ado-PCC in D2O at pH 7.4 was completely analyzed using COSY and NOESY two-dimensional experiments.