Publications

We present a non-invasive method to characterize the function of pluripotent stem-cell-derived cardiomyocytes based on video microscopy and image analysis. The platform, called Pulse, generates automated measurements of beating frequency, beat duration, amplitude, and beat-to-beat variation based on motion analysis of phase-contrast images captured at a fast frame rate. Using Pulse, we demonstrate recapitulation of drug effects in stem-cell-derived cardiomyocytes without the use of exogenous labels and show that our platform can be used for high-throughput cardiotoxicity drug screening and studying physiologically relevant phenotypes.

The new rhabdoviral genus Tibrovirus currently has two members, Coastal Plains virus and Tibrogargan virus. Here, we report the coding-complete genome sequence of a putative member of this genus, Bivens Arm virus. A genomic comparison reveals Bivens Arm virus to be closely related to, but distinct from, Tibrogargan virus.

Mast cells (MC) and myeloid dendritic cells (DC) act proximally in detecting and processing antigens and immune insults. We sought to understand their comparative dynamic behavior with respect to the airway epithelium in the steady state and in response to an allergic stimulus in mouse trachea. We devised methods to label MC in living trachea and to demonstrate that MC and DC occupy distinct layers of the tracheal mucosa, with DC being closer to the lumen. DC numbers doubled after allergen challenge, but MC numbers remained stable. MC and DC migrated minimally in either steady state or allergen-challenge conditions, and their interactions with one another appeared to be stochastic and relatively infrequent. While DC, unlike MC, exhibited probing behaviors involving dendrites, these projections did not cross the epithelium into the airway lumen. MC typically were located too far from the epithelial surface to contact the tracheal lumen. However, MC had protrusions toward and into blood vessels, likely to load with IgE. Thus, DC and MC occupy distinct niches and engage in sessile surveillance in the mouse trachea. Little or no access of these cell types to the airway lumen suggests that trans-epithelial transport of proteins in the steady state would be required for them to access luminal antigens.

BACKGROUND

Diabetes increases the risk of tuberculosis. We sought to identify populations of persons with diabetes in California at further increased risk for tuberculosis to target tuberculosis infection screening and treatment efforts.

METHODS

We performed a retrospective population-based analysis of adult (aged ≥18 years) tuberculosis cases reported in California during 2010-2012. Tuberculosis cases with and without diabetes were grouped into regions of birth and stratified by age category. Population estimates were calculated using 2011-2012 California Health Interview Survey data. We calculated tuberculosis disease rate and relative risk of tuberculosis among persons with diabetes stratified by birth location and age group; and the number needed to screen and, if positive, treat for tuberculosis infection to prevent one case of active tuberculosis over 5 years (NNS).

RESULTS

During 2010-2012, among 6,050 adults with active tuberculosis in California, 82% were foreign-born and 24% had diabetes. The overall relative risk for tuberculosis among persons with diabetes was 3.5 (95% confidence interval, 3.3-3.7) with a rate of 21 per 100,000 persons with diabetes. The rate among foreign-born persons with diabetes (141.5/100,000) was almost 12 times greater than among nonforeign-born persons with diabetes (12.0/100,000). The NNS was 7,930 among all adults, 2,740 among adults with diabetes, 1,526 among all foreign-born adults, and 596 among foreign-born adults with diabetes.

CONCLUSIONS

In California, foreign-born persons with diabetes had significantly elevated rates of active tuberculosis. Focusing tuberculosis infection screening and treatment efforts on foreign-born persons with diabetes may be a feasible and efficient way to make progress toward tuberculosis elimination in California.