Lactoferrin, an iron-binding protein found in high concentrations in mammalian exocrine secretions, is an important component of the host defense system. It is also a major protein of the secondary granules of neutrophils from which is released upon activation. Due to its potential clinical utility, recombinant human lactoferrin (rhLF) has been produced in various eukaryotic expression systems; however, none of these are fully compatible with humans. Most of the biopharmaceuticals approved by the FDA for use in humans are produced in mammalian expression systems. The Chinese hamster ovary cells (CHO) have become the system of choice for proteins that require post-translational modifications, such as glycoproteins. The aim of this study was to scale-up expression and purification of rhLF in a CHO expression system, verify its glycan primary structure, and assess its biological properties in cell culture models. A stable CHO cell line producing >200 mg/L of rhLF was developed and established. rhLF was purified by a single-step cation-exchange chromatography procedure. The highly homogenous rhLF has a molecular weight of approximately 80 kDa. MALDI-TOF mass spectrometric analysis revealed N-linked, partially sialylated glycans at two glycosylation sites, typical for human milk LF. This novel rhLF showed a protective effect against oxidative stress in a similar manner to its natural counterpart. In addition, rhLF revealed a modulatory effect on cellular redox via upregulation of key antioxidant enzymes. These data imply that the CHO-derived rhLF is fully compatible with the native molecule, thus it has promise for human therapeutic applications.

Vancomycin is the first-line therapy for methicillin-resistant

Vancomycin and daptomycin MICs from 161 isolates of methicillin-resistant Staphylococcus aureus (MRSA)were compared using commercial and in-house broth microdilution, Etest, and common automated methods. Vancomycin Etest MICs were higher than those of other methods, whereas the MICs for daptomycin testing were comparable. Vancomycin MICs vary depending on the testing methodology.Vancomycin is the gold standard for the treatment of serious infections due to methicillin-resistant Staphylococcus aureus (MRSA). Recent guidelines from the Infectious Diseases Society of America (IDSA) state that patients infected with MRSA strains that have a vancomycin MIC of Ն2 g/ml have a higher probability of treatment failure and recommend changing to alternate therapy (9). It is essential that clinical microbiology laboratories accurately determine vancomycin MICs to guide appropriate therapy.Trends toward increasing vancomycin MICs have been noted over the past 5 to 10 years (13). Hypotheses for the increase in vancomycin MICs include "MIC creep," clonal shift, and variation in vancomycin MICs demonstrated with various testing methods (3,10,14). It is critical for laboratorians to be aware of the normal distribution of vancomycin MICs observed by the testing system in use in their institution to properly assess the possibility of MIC creep or strains of MRSA with falsely elevated vancomycin MICs. A "falsely" elevated MIC could lead to an unnecessary change in treatment.The purpose of this study was to compare vancomycin and daptomycin MICs obtained by a variety of testing methods. A total of 161 consecutive blood culture isolates of MRSA were included in this study. The isolates were from Memorial Hermann Hospital, a 700-bed, private, tertiary care, universityaffiliated teaching hospital located within the Texas Medical Center in Houston, Texas, between August 2005 and May 2007. Diversilab sequencing according to the manufacturer's instructions yielded at least seven clones (data not shown), as found in other studies of MRSA isolates from our institution (15). Vancomycin MICs were determined by broth microdilution (BMD) trays prepared commercially and in-house, agarbased methods including Etest (bioMérieux, Durham, NC) and agar dilution, as well as automated BMD methods BD Phoenix, Vitek 2, and Microscan. Daptomycin MICs were determined by commercially prepared BMD trays, Etest, and Microscan. Etest inoculums were performed by hand plating. Agar and broth methods were performed according to CLSI standards using strain ATCC 29213 for quality control with each day of testing (2). All MIC determinations were performed in duplicate, and all commercial systems were used according to the manufacturer's instructions. Agar plates were prepared by serially diluting vancomycin hydrochloride hydrate (Sigma, St. Louis, MO) in Mueller-Hinton (BBL) agar at the following concentrations: 0.25, 0.5, 0.75,1, 1.5, and 2.0 g/ml. Custom-made frozen broth microdilution trays with an expanded dilution range of vancomycin and daptomycin were purchased...

The risk factors for relapse of methicillin-resistant Staphylococcus aureus (MRSA) bacteremia after vancomycin treatment are unknown. Diversilab typing was used to classify recurrent bacteremia as relapse or reinfection. Bacteremia for >7 days and staphylococcal cassette chromosome mec element (SCCmec) type II were independently associated with relapse of MRSA bacteremia after vancomycin treatment.

Neural tube defects (NTDs) are among the most common severely disabling birth defects in the United States, affecting approximately 1-2 of every 1,000 live births. The etiology of NTDs is multifactorial, involving the combined action of both genetic and environmental factors. HOX genes play a central role in establishing the initial body plan by providing positional information along the anterior-posterior body and limb axis and have been implicated in neural tube closure. There are many mouse models that exhibit both naturally occurring NTDs in various mouse strains as well as NTDs that have been created by "knocking out" various genes. A nonparametric linkage method, the transmission disequilibrium test (TDT), was utilized to test the HOX gene family and human equivalents of genes (when known) or the syntenic region in humans to those in mouse models which could play a role in the formation of NTDs. DNA from 459 spina bifida (SB) affected individuals and their parents was tested for linkage and association utilizing polymorphic markers from within or very close to the HOXA, HOXB, HOXC, and HOXD genes as well as from within the genes/gene regions of eight mouse models that exhibit NTDs. No significant findings were obtained for the tested markers.