We have studied concurrent apical/basolateral and regulated/constitutive secretory targeting in filter-grown thyroid epithelial monolayers in vitro, by following the exocytotic routes of two newly synthesized endogenous secretory proteins, thyroglobulin (Tg) and p500. Tg is a regulated secretory protein as indicated by its acute secretory response to secretagogues. Without stimulation, pulse-la...

Neurotransmitters are released from nerve terminals and neuroendocrine cells by calcium-dependent exocytosis of vesicles. Before fusion, vesicles are docked to the plasma membrane and rendered release competent through a process called priming. Electrophysiological methods such as membrane capacitance measurements and carbon fiber amperometry accurately measure the fusion step of exocytosis wit...

BACKGROUND The question of whether Asperger syndrome can be distinguished from autism has attracted much debate and may even incur delay in diagnosis and intervention. Accordingly, there has been a proposal for Asperger syndrome to be subsumed under autism in the forthcoming Diagnostic and Statistical Manual of Mental Disorders, fifth edition, in 2013. One approach to resolve this question has ...

Secondary contact is the reestablishment of gene flow between sister populations that have diverged. For instance, at the end of the Quaternary glaciations in Europe, secondary contact occurred during the northward expansion of the populations which had found refugia in the southern peninsulas. With the advent of multi-locus markers, secondary contact can be investigated using various molecular...

Dissecting the mechanisms of T cell-mediated immunity requires the identification of functional characteristics and surface markers that distinguish between activated and memory T lymphocytes. In this study, we compared the rates of cytokine production by virus-specific primary and memory CD8+ T cells directly ex vivo. Ag-specific IFN-gamma and TNF-alpha production by both primary and long-term...

The mydriatic response to eyedrops of the anticholinergic agent tropicamide at very low concentration (0.01%) has been studied in people with Down's syndrome. By comparison with healthy subjects people with Down's syndrome had responses approximately three times greater, suggesting a peripheral imbalance between cholinergic and adrenergic autonomic influences.

Arcanobacterium haemolyticum is a Gram-positive, β-hemolytic emerging human pathogen that is classified into smooth or rough biotypes. This bacterial species is also a rare pathogen of animals. Smooth biotypes possess smooth colony edges, are moderate to strong in β-hemolysis, and predominately cause wound infections. In contrast, rough biotypes possess rough and irregular colony edges, have we...

We introduce a simple micro-fluidic device containing an actuated flexible membrane, which allows the viscoelastic characterization of cells in small volumes of suspension by loading them in compression and observing the cell deformation in time. From this experiment, we can determine the characteristic time constant of recovery of the cell. To validate the device, two cell types known to have ...

Multisite protein phosphorylation and dephosphorylation are key cellular regulatory mechanisms but their system properties have been difficult to study in vivo and in vitro. Here we show by mathematical analysis that steady-state invariants enable the mechanism of the kinase or the phosphatase to be determined from steady-state measurements. Invariants exist when both enzymes act distributively...