Microfluidic flow cytometry: The role of microfabrication methodologies, performance and functional specification.

Flow cytometry is an invaluable tool utilized in modern biomedical research and clinical applications requiring high throughput, high resolution particle analysis for cytometric characterization and/or sorting of cells and particles as well as for analyzing results from immunocytometric assays. In recent years, research has focused on developing microfluidic flow cytometers with the motivation of creating smaller, less expensive, simpler, and more autonomous alternatives to conventional flow cytometers. These devices could ideally be highly portable, easy to operate without extensive user training, and utilized for research purposes and/or point-of-care diagnostics especially in limited resource facilities or locations requiring on-site analyses.

CFD assessment of the effect of convective mass transport on the intracellular clearance of intracellular triglycerides in macrosteatotic hepatocytes.

Donor livers available to transplant for patients with end-stage liver disease are in severe shortage. One possible avenue to expand the donor pool is to recondition livers that would be otherwise discarded due to excessive fat content. Severely steatotic livers (also known as fatty livers) are highly susceptible to ischemia-reperfusion injury and as a result, primary liver non-function post-transplantation.

Differential regulation of intestinal efflux transporters by pregnancy in mice.

1. In the intestines, the nuclear receptors farnesoid X receptor (Fxr) and pregnane X receptor (Pxr) regulate the transcription of metabolizing enzymes and transporters that dictate the absorption of nutrients and xenobiotics. 2.

Metabolic Flux Distribution during Defatting of Steatotic Human Hepatoma (HepG2) Cells.

Methods that rapidly decrease fat in steatotic hepatocytes may be helpful to recover severely fatty livers for transplantation. Defatting kinetics are highly dependent upon the extracellular medium composition; however, the pathways involved are poorly understood. Steatosis was induced in human hepatoma cells (HepG2) by exposure to high levels of free fatty acids, followed by defatting using plain medium containing no fatty acids, or medium supplemented with a cocktail of defatting agents previously described before.

Elevated sensitivity of macrosteatotic hepatocytes to hypoxia/reoxygenation stress is reversed by a novel defatting protocol.

Macrosteatotic livers exhibit elevated intrahepatic triglyceride (TG) levels in the form of large lipid droplets (LDs), reduced adenosine triphosphate (ATP) levels, and elevated reactive oxygen species (ROS) levels, and this contributes to their elevated sensitivity to ischemia/reperfusion injury during transplantation. Reducing macrosteatosis in living donors through dieting has been shown to improve transplant outcomes. Accomplishing the same feat for deceased donor grafts would require ex vivo exposure to potent defatting agents.

Automated image analysis method for detecting and quantifying macrovesicular steatosis in hematoxylin and eosin-stained histology images of human livers.

Large-droplet macrovesicular steatosis (ld-MaS) in more than 30% of liver graft hepatocytes is a major risk factor for liver transplantation. An accurate assessment of the ld-MaS percentage is crucial for determining liver graft transplantability, which is currently based on pathologists' evaluations of hematoxylin and eosin (H&E)-stained liver histology specimens, with the predominant criteria being the relative size of the lipid droplets (LDs) and their propensity to displace a hepatocyte's nucleus to the cell periphery. Automated image analysis systems aimed at objectively and reproducibly quantifying ld-MaS do not accurately differentiate large LDs from small-droplet macrovesicular steatosis and do not take into account LD-mediated nuclear displacement; this leads to a poor correlation with pathologists' assessments.

Rat hepatocyte culture model of macrosteatosis: effect of macrosteatosis induction and reversal on viability and liver-specific function.

Background & Aims: A common cause of liver donor ineligibility is macrosteatosis. Recovery of such livers could enhance donor availability. Living donor studies have shown diet-induced reduction of macrosteatosis enables transplantation.

Cell-cell interaction modulates neuroectodermal specification of embryonic stem cells.

The controlled differentiation of embryonic stem (ES) cells is of utmost interest to their clinical, biotechnological, and basic science use. Many investigators have combinatorially assessed the role of specific soluble factors and extracellular matrices in guiding ES cell fate, yet the interaction between neighboring cells in these heterogeneous cultures has been poorly defined due to a lack of conventional tools to specifically uncouple these variables. Herein, we explored the role of cell-cell interactions during neuroectodermal specification of ES cells using a microfabricated cell pair array.