Bioassay performance

The organic material accumulated from water and used for bioassays should be representative of that originally present in the water. As much unaltered material as possible should be accumulated. In this sense, the desire for effective accumulation is the same whether the organic mixture is to be separated for identification purposes or used directly for bioassays. The primary intent of this report is to describe some accumulation techniques which are applicable to bioassay requirements and to present preliminary results of bioassays performed on organic mixtures accumulated from drinking water. 

Maltoni C et al Benzene A multipotential carcinogen. Results of long-term bioassays performed at the Bologna Institute of Oncology. AmJ Ind Med 4 589-630, 1983... 

The aim of the present study was to identify the DR CALUX bioassay performance criteria for the analysis of PHAHs in sediment samples in order to implement the bioassay in the assessment of dredged materials for systematic monitoring in the eoming years. Therefore, both an intra-and interlaboratory validation study was performed. 

Special emphasis on bioassays performed in cell culture. 

Contamination (including mycoplasma) and differences in serum lots for cultures can affect bioassay performance. Consequently, it is important to maintain cell lines adequately and use consistent sources of material to ensure reproducibility of test results. Bioassay data generally follow a sigmoidal curve, which can complicate the interpretation of results. 

Factors Considerations When Rodent Bioassays Performed Not Needed... 

For all these tests, interpretation and use would be easier if data on baseline responses were available. Currently, the quantity and quality of baseline data vary between tests. In the cases of standardised tests, such as the earthworm reproduction bioassay, performance criteria exist that can be used to discern if an observed effect is significant. For other assays, information of this type is not available. One area that any work to establish baselines should focus on is the interplay between soil factors, ecotypes and measured responses. This will give baselines for variation within the tests and will help to derive performance criteria that can be used as part of an algorithm to discern the status of a given location. 

When reviewing a natural products manuscript, I look for novelty, significance, and completeness of the study, so that a definite contribution is being made. It is important that the work of others is appropriately cited and built on as a foundation and that the authors try to answer as many questions in their own work as is feasible. The work must be carried out according to accepted standards in terms of collection and authentication of the biological material and in the rigor with which chemical structures are determined, bioassays performed, and synthetic procedures conducted. 

Commune sin-related compounds are shown in Fig. (13). Jadulco and coworkers quite recently isolated communesins B (71), C (80), and D (72) from the fungus Penicillium sp. derived from the Mediterranean sponge Axinella verrucosa [51]. These three communesins have been shown to exhibit moderate antiproliferative activity in several bioassays performed on different leukemia cell lines. 

Of the 19 pesticides grouped in Table II, all were negative in five Phase I bioassays and the Phase 2 bioassays performed. These compounds included insecticides (I), fungicides (F), and herbicides (H). Malath ion, parathion, pentachloronitrobenzene (PCNB), and phorate were also negative for heritable chromosomal effects in the mouse dominant lethal test. The six compounds grouped in Table III that were positive in three or more bioassays were acephate, captan, demeton, folpet, monocrotophos, and trichlorfon. Positive results were seen for demeton in all in vitro tests in Phase 1 and Phase 2. Folpet and captan were positive in all Phase 1 and all Phase 2 in vitro assays except the test for unscheduled DNA synthesis in WI-38 cells. Trichlorfon was positive in all Phase 1 and Phase 2 in vitro tests, with the exclusion of relative toxicity tests with E coli and subtiI is. 

In order to provide additional information for the risk assessment, the Committee performed benchmark dose (BMD) modelling using the carcinogenicity data on ochratoxin A from the rat bioassay performed by the NTP (National Toxicology Program, 1989). The occurrence of combined adenomas and carcinomas in the kidneys of the male rats (Table 2), as the most sensitive sex and species for kidney carcinogenicity of ochratoxin A, was considered the most appropriate data for modelling. 

Additionally, ecotoxicity is assessed through bioassays performed on the compost (or soil) obtained after disintegration of the compostable article. Bioassays are a quick, reliable and economic instrument that allow the verification of the ecotoxicological effects of the overall degraded material, and a rapid comparison among different material formulations. Bioassays are a useful instrument for regulatory purposes and will be discussed in more detail in Chapter 4. 

A stable reference toxin derived from a preparation of crystalline type A neurotoxin was proposed for standardizing botulism toxin bioassays performed in different laboratories under diverse conditions (63). Standardized procedures for using the bioassay for detecting botulism neurotoxin in foods and identifying toxigenicity and toxin type of the organisms were established on the basis of the results of a collaborative study (40). 

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