Performing fiberoptic endotracheal intubation: clinical aspects.
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Anesthesia↗
Biomedical subjects
R A Stackhouse
Publications and source records attributed to R A Stackhouse.
Transtracheal oxygenation and ventilation.
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Humans↗
The effect of humic acid on the toxicity and bioavailability of trivalent chromium.
The influence of humic acid (HA) on the toxicity and bioavailability of two forms of trivalent chromium (chromic chloride and chrome lignosulfonate) was evaluated using a common freshwater invertebrate, Daphnia pulex. With both compounds, the 50 mg/liter HA significantly decreased toxicity at all time points examined. The remaining two HA concentrations, 0.5 and 5 mg/liter, either had no influence or decreased the toxicity of the compounds. Humic acid appeared to have no influence on the bioavailability of chrome lignosulfonate. However, for chromic chloride, 5 and 50 mg/liter HA decreased the percentage free chromium at all time points examined.
Animals↗
Influence of cadmium exposure on selected hematological parameters in freshwater teleost, Notemigonus crysoleucas.
The use of hematological parameters for assessing the acute toxicity of heavy metals to mammals has shown considerable promise. These parameters include the measurement of blood glucose, hematocrit, and a variety of enzymes. The present investigation was undertaken to evaluate the use of selected hematological parameters in aquatic organisms. Exposure of Notemigonus crysoleucas to cadmium resulted in a 96-hr LC50 value of 3.15 mg Cd/liter. The influence of cadmium on selected hematological parameters was examined following 96 hr of exposure to 0, 1.35, and 2.40 mg Cd/liter. Cadmium exposure produced significant alterations (P less than 0.05) in the levels of glucose, aspartate aminotransaminase, and alanine aminotransaminase. Hematocrit was not altered by exposure to cadmium. These results indicate that glucose and transaminases may be useful as diagnostic tests for cadmium exposure in aquatic organisms.
Animals↗
Evaluation of a new approach to the safety assessment of biomaterials.
The effectiveness of a bacterial luminescence inhibition assay in assessing the toxicity of compounds which are released from biomaterials was evaluated. Luminescence from a strain of bacteria most closely resembling Photobacterium phosphoreum was measured. The concentration that inhibited luminescence by 50% (EC50) was determined for selected plasticizers, monomers and additives. The intraperitoneal (i.p.-ALD) and intravenous (i.v.-ALD) approximate lethal doses were determined using mice. By ranking the reference compounds toxic/non-toxic, a 37.5% agreement was obtained for the i.p.-ALD and i.v.-ALD toxicity data. While there was only a 12.5% agreement for the i.p. ALD and EC50 values, there was a 75% agreement between the i.v.-ALD and EC50 values. Although additional validation is required, these results provide preliminary indications that the bacterial luminescence inhibition assay is a promising alternative approach to the safety assessment of biomaterials.
Animals↗