Screen for small molecules increasing the mitochondrial membrane potential.

The identification of small molecules that positively modulate the mitochondrial respiratory function has broad applications in fundamental research, therapeutic target validation, and drug discovery. We present an approach in which primary screens for mitochondrial function in yeast are used to efficiently identify a subset of high-value compounds that can in turn be rapidly tested against a broad range of mammalian cell lines. The ability of the yeast assay to successfully identify in a high-throughput format hit compounds that increase the mitochondrial membrane potential and adenosine triphosphate (ATP) levels by as little as 15% was demonstrated. In this study, 14 hits were identified from a collection of 13,680 compounds. Secondary testing with myotubes, fibroblasts, and PC-12 and HepG2 cells identified two compounds increasing ATP levels in hepatocytes and two other compounds increasing ATP in fibroblasts. The effect on hepatocytes was further studied using genomic and mitochondrial proteomic tools to characterize the changes induced by the two compounds. Changes in the accumulation of a series of factors involved in early gene response or apoptosis or linked to metabolic functions (i.e., ß-Klotho, RORα, PGC-1α, G6PC, IGFBP1, FTL) were discovered.

A portable cell-based impedance sensor for toxicity testing of drinking water.

A major limitation to using mammalian cell-based biosensors for field testing of drinking water samples is the difficulty of maintaining cell viability and sterility without an on-site cell culture facility. This paper describes a portable automated bench-top mammalian cell-based toxicity sensor that incorporates enclosed fluidic biochips containing endothelial cells monitored by Electric Cell-substrate Impedance Sensing (ECIS) technology. Long-term maintenance of cells on the biochips is made possible by using a compact, self-contained disposable media delivery system. The toxicity sensor monitors changes in impedance of cell monolayers on the biochips after the introduction of water samples. The fluidic biochip includes an ECIS electronic layer and a polycarbonate channel layer, which together reduce initial impedance disturbances seen in commercially available open well ECIS chips caused by the mechanics of pipetting while maintaining the ability of the cells to respond to toxicants. A curve discrimination program was developed that compares impedance values over time between the control and treatment channels on the fluidic biochip and determines if they are significantly different. Toxicant responses of bovine pulmonary artery endothelial cells grown on fluidic biochips are similar to cells on commercially-available open well chips, and these cells can be maintained in the toxicity sensor device for at least nine days using an automated media delivery system. Longer-term cell storage is possible; bovine lung microvessel endothelial cells survive for up to four months on the fluidic biochips and remain responsive to a model toxicant. This is the first demonstration of a portable bench top system capable of both supporting cell health over extended periods of time and obtaining impedance measurements from endothelial cell monolayers after toxicant exposure.

[Correlation between chronic idiopathic urticaria and infection due to H. pylori]. / Correlación entre urticaria crónica idiopática e infección por H. pylori.

BACKGROUND: H. pylori is considered one of the major etiological agents for chronic idiopathic urticaria; it infects 15 percent of the world's population and induces an inflammatory process in the gastric mucosa. In some cases it is related to chronic urticaria, even in the absence of digestive symptoms. OBJECTIVE: The purpose of this study is to find the correlation between chronic idiopathic urticaria and infection due to Helicobacter pylori. PATIENTS AND METHODS: Twenty patients with chronic idiopathic urticaria and a positive urea breath test for H. pylori were included in the study. All other frequent pathologies were eliminated. Patients began treatment with amoxicillin, clarithromycin and omeprazole for 14 days. Thirty days after the start of treatment, the urea breath test was performed in all of the patients. Also cutaneous symptoms were evaluated. RESULTS: Urticaria disappeared in 11 patients (55%), in 9 (45%) the urea breath test became negative and in two remained positive. Urticaria persisted in 9 patients (45%), in 6 (30%) the urea breath test was negative and in 3 (15%) persisted as positive. Only two patients (10%) experienced gastric symptoms. CONCLUSION: We found a correlation between the disappearance of the symptoms and a negative urea breath test in 45 percent of the patients who were studied. We must consider the possibility of H. pylori infection, which can be present even without gastric symptoms.