Particle bioassay

Particle bioassay method was used lo test the activity of extracts. aPlant materials were ground or cut into small pieces and extracted with 70% acetone. 

Compounds 19 and 20 along with some acylated phosphatidic derivatives in addition to 1,2-dioleoylphosphatidic acid, were tested using the particle bioassay [83]. Commercially available l-oleoyl-2-lysophosphatidic acid (21) possessed repellent activity which was enhanced by monomethylation. When A. cochlioides zoospores were pre-treated with an excess of the natural stimulant N-frans-feruloyltyramine (19), and then exposed to Chromosorb W AW particles coated with various test compounds, it was found that 1 -oleoyl-2-lysophosphatidic (21, 100 ppm) and its monomethyl ester (22) (10 ppm), as well as the natural repellent 1-linoleoyl-2-lysophosphatidic acid monomethyl ester (20, 30 ppm), effectively inhibited zoospore motility [83], However, l-oleoyl-2-lysophosphatidic acid dimethyl ester (23) and 1,2-dioleoylphosphatidic acid tested with and without the stimulant (19) showed neither repellent nor motility inhibitory activity. The bioassay revealed that compounds possessing repellent activity are monoacylated phosphatidic acid derivatives containing at least one hydroxy group on the phosphoryl unit [83]. 

Endocrine disrupters (e.g., bisphenol A) are supposed to be the pollutants in our environment and pose a serious concern in human health. The minute amount of these compounds in our environment is difficult to detect mainly due to lack of a simple and sensitive bioassay method. In the present study, the estrogenic and repellent activities of known estrogenic compounds revealed to be correlated. The particle bioassay method is very simple and... 

The vast majority of bioassays on marine organisms have been conducted on toxicants that are soluble in seawater. Because drilling mud contains solid particles, a special procedure had to be developed. 

Gustavson, K.E., Svenson, A., and Harkin, J.M. Comparison of toxicities and mechanism of action of / -alkanols in the submitochondrial particle and the Vibrio fischeri bioluminescence (Microtox ) bioassay. Environ. Toxicol. Chem., 17(10) 1917-1921, 1998. 

Due to the lack of bioassays that mimic the situation of toxin-containing food particles, most of the work has been performed on herbivores that feed on diets of phytoplankton species with different degrees of toxicity. This has led to multiple variant parameters, not allowing the direct comparison of effects due to the varying toxin contents. In a few cases, these studies have the advantage of being able to directly compare different clones of one species with variable toxicities but otherwise comparable biochemical composition. There, the effect of the toxins can be determined without overlaying effects due to different nutritional quality of the food. 

Throughout this chapter, we cite examples of the use of the NIST Standard Reference Material SRM 1649, which is referred to as Air Particles or Urban Air Particulate Matter, (a) to validate analytical procedures for determination of PAHs and PACs in samples of complex mixtures of particulate matter in ambient air and (b) for laboratory intercomparisons of methodologies for bacterial bioassays and bioassay-directed fractionations of organic extracts of such mixtures (e.g., see Claxton et al., 1992a Lewtas et al., 1990a, 1992 and May et al., 1992). 

As with the Salmonella reversion assay, this shortterm test is conducted both without (— PMS) and with metabolic activation produced by addition of post-mitochondrial supernatant containing rat liver enzymes ( + PMS). These terms are equivalent to — S9 and + S9 in the Ames reversion assay we use the latter designation for both types of bacterial assays. A more sensitive micro-forward mutation bioassay using this TM677 strain to determine the mutagenicity of indoor air particles, including ETS and wood smoke, is described by Lewtas et al. (1987). 

Bioassay-Directed Chemical Analysis for Vapor-Phase and Particle-Phase PAHs and PACs in Ambient Air Using Bacterial Assays... 

Figure 10.25 shows these mutagrams for the vapor and particle phases, respectively. Interestingly, the total direct mutagenicity of the vapor phase, 210 rev m-3, was actually greater than that of the particle phase, 160 rev m 3 furthermore, its mutagenicity profile was substantially different. Thus, fraction 4 is the major peak for the vapor-phase sample whereas most of the particle-phase mutagenicity is in the more polar peaks 6 and 7. Similar enhancements in the contributions of more polar species were reported for bioassay-directed fractionation of SRM 1649 urban air particulate matter (Schuetzle and Lewtas, 1986 Nishioka et al., 1988 ... 

For example, Legzdins and co-workers (1994) used the bioassay-directed fractionation and chemical analysis technique to isolate, identify, and quantify 2-nitrofluoranthene in extracts of ambient particles collected in Hamilton, Ontario, Canada. They found it accounted for 70% of the total nonpolar direct bacterial mutagenicity (strain YG1021, standard reversion assay, Maron and Ames, 1983). 

Huisingh, J., R. Bradow, R. Jungers, L. Claxton, R. Zweidinger, S. Tejada, J. Bumgarner, F. M. Waters, V. F. Simmon, C. Hare, C. Rodgriguez, and L. Snow, Application of Bioassay to Characterization of Diesel Particle Emissions, in Applications of Short-Term Bioassay in the Fractionation and Analysis of Complex Environmental Mixtures (M. D. Waters, S. Nesnow, J. L. Huisingh, S. Sandhu, and L. Claxton, Eds.), pp. 383-418, Plenum, New York, 1979. 

Although this chapter focuses on applications with effluent wastewaters, all types of aquatic environmental media (freshwater, brackish, marine) can be appraised with the pT-scale procedure. Testing of liquid samples is virtually unlimited and can include untreated and treated wastewater, surface water, ground water, porewater, elutriates and organic extracts of sediments. Applications could also be extended to assess toxicity of particle-bound substances in suspended matter and sediments. In this case, sample dilutions can be made with reference sediment material (Hoss and Krebs, 2003). The pT-method can also capture the effects of both soluble and particulate toxicity in a sample, provided that appropriate bioassays are employed. 

One of the most sensitive bioassays for osteoblast and osteoclast activities in vivo is the use of ectopic models of bone formation and bone matrix resorption (38,39). Devitalized, demineralized bone powders (DBP) are subcutaneously implanted in young rats. There is a phenotypic conversion of connective cell tissue mesenchyme into cartilage. Subsequently this cartilage becomes calcified, vascularized and bone is deposited in two weeks. If mineral-containing bone particles (BP) are implanted, a different phenomenon is observed. Large multinucleated osteoclast-like cells are recruited to the site of implantation. There is a complete resorption of the BP four weeks after implantation. In collaboration with Dr. Julie Glowacki of the Harvard University School of Medicine, we took advantage of these procedures and used implants of normal DBP and BP into rats that had been maintained on the three experimental diets C, L, and D (40). 

The National Toxicology Program (NTP) has not evaluated uranium compounds in rodent cancer bioassays by any route for the potential to induce cancer in humans. However, because uranium emits predominantly high-LET alpha particles, current theories on gene mutation and apoptotic mechanisms of... 

Cancer. There has been interest in the potential carcinogenicity of uranium, which emits alpha-particle radiation, although natural, depleted, or enriched uranium or uranium compounds have not been evaluated in rodent cancer bioassays by any route by the NTP (BEIR 1980, 1988, 1990 Hahn 1989 Otake and Schull 1984 Sanders 1986 UNSCEAR 1982, 1986, 1988). However, there is no unequivocal evidence that inhalation, oral, or dermal exposure induces cancers in humans because it is difficult to isolate the... 

The nse of high-speed LC-MS-MS with a heated-nebrrhzer atmospheric-pressnre chemical ionization (APCI) interface in a bioassay for phenylbutazone and its metabolites in eqnine urine and plasma, described by Covey et al. [1] in 1986, can be considered as a breakthrough in LC-MS. Phenylbutazone, hydroxy-phenylbutazone, and oxy-phenylbutazone were separated on a 33x4.6-mm-ID colunm packed with 3-pm particles in only 1 min. SRM of fottr product iorts per analyte was apphed. The results for phenylbutazone in a 60-sample, 48-h phenylbntazone pharmacokinetic study are shown in Figrtre 11.1. A set of 5 standards, 11 plasma samples, and 11 urine samples were analysed in duplo within 60 min [1]. 

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