A transcytotic transport mechanism across the tympanic membrane.

Drug treatments for middle ear diseases are currently delivered systemically, or locally after opening the impermeable tympanic membrane (TM). We previously used bacteriophage display to discover novel peptides that are actively transported across the intact TM, with a variety of transport rates. Peptide structures were analyzed for evidence regarding the mechanism for this unexpected transport, which was then tested by the application of chemical inhibitors. Primary sequences indicated that trans-TM peptides share one of two amino acid motifs. Secondary structures revealed that linear configurations associate with higher transport rates than coiled structures. Tertiary analysis indicated that the shared sequence motifs are prominently displayed at the free ends of rapidly transported peptide phage. The shared motifs were evaluated for similarity to known motifs. The highest probability matches were for protein motifs involved in transmembrane transport and exosomes. Overall, structural findings suggest that the shared motifs represent binding sequences. They also implicate transcytosis, a polarized cell transport mechanism consisting of endocytosis, transcellular transport, and exocytosis. Inhibitor studies indicated that macropinocytosis, retrograde transport through Golgi and exocytosis participate in transport across the TM, consistent with transcytosis. This process can be harnessed to noninvasively deliver therapeutics to the middle ear.

Isolation and characterization of Streptomyces bacteriophages and Streptomyces strains encoding biosynthetic arsenals.

The threat to public health posed by drug-resistant bacteria is rapidly increasing, as some of healthcare's most potent antibiotics are becoming obsolete. Approximately two-thirds of the world's antibiotics are derived from natural products produced by Streptomyces encoded biosynthetic gene clusters. Thus, to identify novel gene clusters, we sequenced the genomes of four bioactive Streptomyces strains isolated from the soil in San Diego County and used Bacterial Cytological Profiling adapted for agar plate culturing in order to examine the mechanisms of bacterial inhibition exhibited by these strains. In the four strains, we identified 104 biosynthetic gene clusters. Some of these clusters were predicted to produce previously studied antibiotics; however, the known mechanisms of these molecules could not fully account for the antibacterial activity exhibited by the strains, suggesting that novel clusters might encode antibiotics. When assessed for their ability to inhibit the growth of clinically isolated pathogens, three Streptomyces strains demonstrated activity against methicillin-resistant Staphylococcus aureus. Additionally, due to the utility of bacteriophages for genetically manipulating bacterial strains via transduction, we also isolated four new phages (BartholomewSD, IceWarrior, Shawty, and TrvxScott) against S. platensis. A genomic analysis of our phages revealed nearly 200 uncharacterized proteins, including a new site-specific serine integrase that could prove to be a useful genetic tool. Sequence analysis of the Streptomyces strains identified CRISPR-Cas systems and specific spacer sequences that allowed us to predict phage host ranges. Ultimately, this study identified Streptomyces strains with the potential to produce novel chemical matter as well as integrase-encoding phages that could potentially be used to manipulate these strains.

The relationship between alcohol consumption and glycemic control among patients with diabetes: the Kaiser Permanente Northern California Diabetes Registry.

BACKGROUND: Alcohol consumption is a common behavior. Little is known about the relationship between alcohol consumption and glycemic control among people with diabetes. OBJECTIVE: To evaluate the association between alcohol consumption and glycemic control. DESIGN: Survey follow-up study, 1994-1997, among Kaiser Permanente Northern California members. PATIENTS: 38,564 adult diabetes patients. MEASUREMENTS: Self-reported alcohol consumption, and hemoglobin A1C (A1C), assessed within 1 year of survey date. Linear regression of A1C by alcohol consumption was performed, adjusted for sociodemographic variables, clinical variables, and diabetes disease severity. Least squares means estimates were derived. RESULTS: In multivariate-adjusted models, A1C values were 8.88 (lifetime abstainers), 8.79 (former drinkers), 8.90 (<0.1 drink/day), 8.71 (0.1-0.9 drink/day), 8.51 (1-1.9 drinks/day), 8.39 (2-2.9 drinks/day), and 8.47 (>/=3 drinks/day). Alcohol consumption was linearly (p < 0.001) and inversely (p = 0.001) associated with A1C among diabetes patients. CONCLUSIONS: Alcohol consumption is inversely associated with glycemic control among diabetes patients. This supports current clinical guidelines for moderate levels of alcohol consumption among diabetes patients. As glycemic control affects incidence of complications of diabetes, the lower A1C levels associated with moderate alcohol consumption may translate into lower risk for complications.