Evaluation of the BacterioScan 216Dx for Standalone Preculture Screen of Preserved Urine Specimens in a Clinical Setting.

Background: The BacterioScan 216Dx laser microbial growth monitoring system was evaluated as an option for preurine culture screening of preserved urine specimens at an acute care medical center.

Methods: The BacterioScan 216Dx system performance characteristics and the economic impact (cost effectiveness) for the laboratory were assessed. Urinalysis performance compared to urine culture was assessed if urinalysis was ordered as part of the patient care set.

TPC2 controls pigmentation by regulating melanosome pH and size.

Melanin is responsible for pigmentation of skin and hair and is synthesized in a specialized organelle, the melanosome, in melanocytes. A genome-wide association study revealed that the two pore segment channel 2 (TPCN2) gene is strongly linked to pigmentation variations. TPCN2 encodes the two-pore channel 2 (TPC2) protein, a cation channel.

TPC2 mediates new mechanisms of platelet dense granule membrane dynamics through regulation of Ca2+ release.

Platelet dense granules (PDGs) are acidic calcium stores essential for normal hemostasis. They develop from late endosomal compartments upon receiving PDG-specific proteins through vesicular trafficking, but their maturation process is not well understood. Here we show that two-pore channel 2 (TPC2) is a component of the PDG membrane that regulates PDG luminal pH and the pool of releasable Ca(2+).

Myosin vc interacts with Rab32 and Rab38 proteins and works in the biogenesis and secretion of melanosomes.

Class V myosins are actin-based motors with conserved functions in vesicle and organelle trafficking. Herein we report the discovery of a function for Myosin Vc in melanosome biogenesis as an effector of melanosome-associated Rab GTPases. We isolated Myosin Vc in a yeast two-hybrid screening for proteins that interact with Rab38, a Rab protein involved in the biogenesis of melanosomes and other lysosome-related organelles.

Mechanism of platelet dense granule biogenesis: study of cargo transport and function of Rab32 and Rab38 in a model system.

Dense granules are important in platelet aggregation to form a hemostatic plug as evidenced by the increased bleeding time in mice and humans with dense granule deficiency. Dense granules also are targeted by antiplatelet agents because of their role in thrombus formation. Therefore, the molecular understanding of the dense granule and its biogenesis is of vital importance.

Isolation and characterization of cytoplasmic cofilin-actin rods.

Cofilin-actin bundles (rods), which form in axons and dendrites of stressed neurons, lead to synaptic dysfunction and may mediate cognitive deficits in dementias. Rods form abundantly in the cytoplasm of non-neuronal cells in response to many treatments that induce rods in neurons. Rods in cell lysates are not stable in detergents or with added calcium.

Strongylocentrotus drobachiensis oocytes maintain a microtubule organizing center throughout oogenesis: implications for the establishment of egg polarity in sea urchins.

Although it has been known for over a century that sea urchin eggs are polarized cells, very little is known about the mechanism responsible for establishing and maintaining polarity. Our previous studies of microtubule organization during sea urchin oogenesis described a cortical microtubule-organizing center (MTOC) present during germinal vesicle (GV) migration in large oocytes. This MTOC was localized within the future animal pole of the mature egg.

Formation of actin-ADF/cofilin rods transiently retards decline of mitochondrial potential and ATP in stressed neurons.

When neurons in culture are transiently stressed by inhibition of ATP synthesis, they rapidly form within their neurites rodlike actin inclusions that disappear when the insult is removed. Oxidative stress, excitotoxic insults, and amyloid beta-peptide oligomers also induce rods. Immunostaining of neurites indicates that these rods also contain the majority of the actin filament dynamizing proteins, actin-depolymerizing factor (ADF) and cofilin (AC).

Beta-secretase-cleaved amyloid precursor protein accumulates at actin inclusions induced in neurons by stress or amyloid beta: a feedforward mechanism for Alzheimer's disease.

Rod-like inclusions (rods), composed of actin saturated with actin depolymerizing factor (ADF)/cofilin, are induced in hippocampal neurons by ATP depletion, oxidative stress, and excess glutamate and occur in close proximity to senile plaques in human Alzheimer's disease (AD) brain (Minamide et al., 2000). Here, we show rods are found in brains from transgenic AD mice.

In vitro activity differences between proteins of the ADF/cofilin family define two distinct subgroups.

The actin depolymerizing factor (ADF)/cofilins are an essential group of proteins that are important regulators of actin filament turnover in vivo. Although protists and yeasts express only a single member of this family, metazoans express two or more members in many cell types. In cells expressing both ADF and cofilin, differences have been reported in the regulation of their expression, their pH sensitivity, and their intracellular distribution.