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Endotoxin Detection in Body Fluids: Chemical Versus Bioassay Methodology
Published in Helmut Brade, Steven M. Opal, Stefanie N. Vogel, David C. Morrison, Endotoxin in Health and Disease, 2020
Due to the numerous biological responses to endotoxin and the complexity of the molecule, it is not surprising that quite a few assays for endotoxin have been described in the literature. It is quite obvious, however, that only a few of these, namely the LAL assay (and variations thereof) and the cell culture assays, lend themselves to widespread use. The question still remaining, however, is how suitable these tests are for assessing the bioactivity of endotoxin. Is it sufficient to know the total amount (as a chemical entity) of endotoxin present or its bioactivity (however that may be defined)? Of course the methods need much more testing before we can attempt to answer these questions. It seems, however, that a sensitive, accurate, and precise chemical test is required before the bioactivity issue can be resolved. Whether the LAL assay can be standardized to a point that meets these criteria (the LAL assay does have a bioactivity issue) remains to be seen.
Physico-Chemical Methods for the Quality Control of Medicinal Plants, Plant Derivatives and Phytomedicines in Brazil
Published in Luzia Valentina Modolo, Mary Ann Foglio, Brazilian Medicinal Plants, 2019
Paula Carolina Pires Bueno, Alberto José Cavalheiro
For plant raw materials, the Brazilian Pharmacopoeia 5th edition suggests a sampling plan, which considers the amount of sample available, the numbers of containers and the level of division of the drug (Table 2.2). Overall, for drugs finely fragmented, pulverized or with dimensions smaller than 1.0 cm, the sample must be at least 250.0 g, considering a total amount batch up to 100 kg, and/or at least an amount, which is sufficient for the execution of every physico-chemical test with further amount for sample. For drugs with dimensions greater than 1.0 cm, the sample must be at least 500.0 g. If the total amount of the received batch is smaller than 10 kg, the final sample must be at least 125.0 g. The samples must be taken in similar amounts from the superior part, middle and inferior part of each container to be sampled. In the end, every portion must be joined, homogenized and divided in four equal parts, separating the sample over a square area. Then, the two diagonal parts must be put together followed by the remaining parts. If necessary, the process must be repeated until there is no accentuated difference in the dimensions of the fragments in question. Finally, a part of this sampled and homogenized material must be retained as a reference sample, which might be used in any retesting procedures if necessary.
Principles of forensic science and crime scene investigation
Published in Jason Payne-James, Richard Jones, Simpson's Forensic Medicine, 2019
Jason Payne-James, Richard Jones
If a male has been vasectomised successfully, no sperm cells should be present within an ejaculate. In these cases, a second chemical test can be used for confirmation. Prostate specific antigen (PSA) found in semen uses an antibody-based technique. The Florence Iodine test to detect choline in seminal fluid can also be used in which a small amount of the reagent is introduced to a slide carrying some of the extracted stain. The iodine in a potassium iodide solution is precipitated by the chemically basic choline forming characteristic brown crystals, suggesting the presence of semen. However, this method is not considered to be very sensitive and caution should be taken in the interpretation of the results.
Risk characterisation of constituents present in jamu to promote its safe use
Published in Critical Reviews in Toxicology, 2021
Suparmi Suparmi, Dasep Wahidin, Ivonne M. C. M. Rietjens
The overview presented in Table 1 and Supplemental material 1 clearly indicates the potential presence of API adulteration in jamu. Many of the case reports summarised in these tables lack details that would be important for a rigorous hazard and risk assessment. For instance, some fail to mention the exact level of the APIs detected in the samples showing their presence only by qualitative analysis using thin layer chromatography (TLC) (Gitawati 2013; Wisnuwardhani et al. 2013; Fauziah et al. 2015; Mustarichie et al. 2017), a spot test (Hanum et al. 2017), or a qualitative chemical test (Maesaroh 2020). Other issues hampering hazard and/or risk assessment are the simultaneous presence of more than one API (Lau et al. 2003; Doshi et al. 2009), or the lack of a description of the recommended daily use of these jamu samples to assess the potential exposure to APIs resulting from consuming the jamu.
Effect of biotransformation by liver S9 enzymes on the mutagenicity and cytotoxicity of melanin extracted from Aspergillus nidulans
Published in Pharmaceutical Biology, 2016
Rita de Cássia Ribeiro Gonçalves, Rodrigo Rezende Kitagawa, Eliana Aparecida Varanda, Maria Stella Gonçalves Raddi, Carla Andrea Leite, Sandra Regina Pombeiro Sponchiado
Substances with known biological activities, such as melanin, are tested for their cytotoxic and mutagenic effects to determine possible adverse effects that may prevent their use as therapeutic agents. The Ames test (Salmonella/Mammalian Microsome Mutagenesis Assay), which can be used to evaluate chemically induced genotoxicity and mutagenicity, is the most accepted and widely used in vitro assay for this purpose. This test assesses the abilities of certain agents to induce gene mutations in different strains of Salmonella typhimurium (Maron and Ames 1983; Mortelmans and Zeiger 2000). In vitro cytotoxicity assays have been widely used for chemical screening due to the high costs, lengthy experimental times, significant laboratory space requirements, and socioethical concerns associated with testing on laboratory animals. These factors have led to the development of in vitro assays that serve as alternatives to acute in vivo toxicity testing. One in vitro approach has been the use of established cell lines in cytotoxicity assays to determine the acute potencies of chemical test agents (Eisenbrand et al. 2002; Ukelis et al. 2008).
In vitro metabolism of imidacloprid and acetamiprid in rainbow trout and rat
Published in Xenobiotica, 2020
Richard C. Kolanczyk, Mark A. Tapper, Barbara R. Sheedy, Jose A. Serrano
Chemical test solutions were prepared and then dispensed into the appropriate wells. For example, 200 μM IMI was prepared by the addition of 5.4 μL of 367 mM IMI to 10 mL of exposure media. Then 1.7 mL of this test solution was added to the appropriate well. Test solutions in 12-well plates were equilibrated to incubation temperature before the addition of liver slices to wells. Plates were incubated at 11 °C on an orbital shaker. Incubation was terminated by removing 500 μL of exposure media from well, then adding it to a microfuge tube containing 200 μL ACN. These samples were processed for chemical evaluation (see Chemical and metabolite analyses section).