Publications by authors named "William van der Schalie"

In the military, combat wound infections can progress rapidly to life-threatening sepsis. The discovery of effective small-molecule drugs to prevent and/or treat sepsis is a priority. To identify potential sepsis drug candidates, we used an optimized larval zebrafish model of endotoxicity/sepsis to screen commercial libraries of drugs approved by the U.

View Article and Find Full Text PDF

Engineered nanomaterials pose occupational health and environmental concerns as they possess unique physical and chemical properties that can contribute to toxicity. High throughput toxicity screening methods are needed to address the increasing number of nanomaterials in production. Here we used a zebrafish photomotor response (PMR) test to evaluate a set of fifteen nanomaterials with military relevance.

View Article and Find Full Text PDF

Resuscitation and detection of stressed total coliforms in chlorinated water samples is needed to assess and prevent health effects from adverse exposure. In this study, we report that the addition of a growth enhancer mix consisting of trehalose, sodium pyruvate, magnesium chloride, and 1× trace mineral supplement improved growth of microorganisms from chlorinated secondary effluent in the base medium with Colilert-18. Improving growth of chlorine stressed microorganisms from secondary effluent is crucial to decreased detection time from 18 to 8 h.

View Article and Find Full Text PDF

Zebrafish are an attractive model for chemical screening due to their adaptability to high-throughput platforms and ability to display complex phenotypes in response to chemical exposure. The photomotor response (PMR) is an established and reproducible phenotype of the zebrafish embryo, observed 24 h post-fertilization in response to a predefined sequence of light stimuli. In an effort to evaluate the sensitivity and effectiveness of the zebrafish embryo PMR assay for toxicity screening, we analyzed chemicals known to cause both neurological effects and developmental abnormalities, following both short (1 h) and long (16 h+) duration exposures.

View Article and Find Full Text PDF

This manuscript describes how to prepare fluidic biochips with Rainbow trout gill epithelial (RTgill-W1) cells for use in a field portable water toxicity sensor. A monolayer of RTgill-W1 cells forms on the sensing electrodes enclosed within the biochips. The biochips are then used for testing in a field portable electric cell-substrate impedance sensing (ECIS) device designed for rapid toxicity testing of drinking water.

View Article and Find Full Text PDF

The US Army's need for a reliable and field-portable drinking water toxicity sensor was the catalyst for the development and evaluation of an electric cell-substrate impedance sensing (ECIS) device. Water testing technologies currently available to soldiers in the field are analyte-specific and have limited capabilities to detect broad-based water toxicity. The ECIS sensor described here uses rainbow trout gill epithelial cells seeded on fluidic biochips to measure changes in impedance for the detection of possible chemical contamination of drinking water supplies.

View Article and Find Full Text PDF

Rainbow trout gill epithelial cells (RTgill-W1) are used in a cell-based biosensor that can respond within one hour to toxic chemicals that have the potential to contaminate drinking water supplies. RTgill-W1 cells seeded on enclosed fluidic biochips and monitored using electric cell-substrate impedance sensing (ECIS) technology responded to 18 out of the 18 toxic chemicals tested within one hour of exposure. Nine of these chemical responses were within established concentration ranges specified by the U.

View Article and Find Full Text PDF

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.

View Article and Find Full Text PDF

A number of toxicity sensors for testing field water using a range of eukaryotic cell types have been proposed, but it has been difficult to identify sensors with both appropriate sensitivity to toxicants and the potential for long-term viability. Assessment of bovine pulmonary artery endothelial cell (BPAEC) monolayer electrical impedance with electric cell-substrate impedance sensing (ECIS) showed promise in a previous systematic evaluation of toxicity sensor technologies. The goal of the study reported here was to improve toxicant responsiveness and field portability of this cell-based toxicity sensor.

View Article and Find Full Text PDF

We have evaluated a Xenopus cell line as a potential sensor for detecting toxins in water. X. laevis melanophores responded rapidly by dispersing melanosomes following exposure to six (ammonia, arsenic, copper, mercury, pentachlorophenol and phenol) of 12 tested chemicals in the desired sensitivity range.

View Article and Find Full Text PDF

Comprehensive identification of chemical contaminants in Army field water supplies can be a lengthy process, but rapid analytical methods suitable for field use are limited. A complementary approach is to directly measure toxicity instead of individual chemical constituents. Ten toxicity sensors utilizing enzymes, bacteria, or vertebrate cells were tested to determine the minimum number of sensors that could rapidly identify toxicity in water samples containing one of 12 industrial chemicals.

View Article and Find Full Text PDF

A PHP Error was encountered

Severity: Warning

Message: fopen(/var/lib/php/sessions/ci_sessionaegbejtf0ijkol0in2h33kkcm616eiu5): Failed to open stream: No space left on device

Filename: drivers/Session_files_driver.php

Line Number: 177

Backtrace:

File: /var/www/html/index.php
Line: 316
Function: require_once

A PHP Error was encountered

Severity: Warning

Message: session_start(): Failed to read session data: user (path: /var/lib/php/sessions)

Filename: Session/Session.php

Line Number: 137

Backtrace:

File: /var/www/html/index.php
Line: 316
Function: require_once