Lines assay

PNA Target Method Modification Cell type/line Assay Reference... 

To enable the validity of the assay to be examined, it is desirable to use at least three doses of the Standard Preparation and of the substance being examined. It is also advisable to use doses in logarithmic progression in a parallel line assay. 

The statistical evaluation by means of fhe four-point parallel line assay resulted for the Aronal forte toothpaste in a significant higher activity of factor 1.11 (C.l. 1.03-1.19 p = 0.05) in comparison to the dental gel standard. The evaluation carried out on the quality of the experiment... 

Incubate at least four series, cells with three or more different concentrations of the preparation to be examined and the reference preparation in a microtitre plate and include in each series appropriate controls of untreated cells. Choose the concentrations of the preparations such that the lowest concentration produces some protection and the largest concentration produces less than maximal protection against the viral cytopathic effect. At a suitable time add the cytopathic virus to the wells with the exception of a sulScient number of wells in ah series, which are left with uninfected control cells. Determine the cytopathic effect of virus quantitatively with a suitable method. Calculate the potency of the preparation to be examined by the usual statistical methods for a parallel line assay. 

Posner and coworkers have prepared a series of semi-synthetic and synthetic ether and ester-linked dimers that were found to have potent anti-proliferative and antitumour activities in vitro. Some of these trioxane dimers were found to be as antiproliferative as calcitriol, the hormonally active form of vitamin D, which is used to treat psoriasis, a skin disorder characterized by uncontrolled cell prohferation. Of the semi synthetic dimers, a polyethylene glycol-linked dimer 107, with S-stereochemistry at both of the lactol acetal positions, was found to be very anti-proliferative and showed activity against leukaemia and colon cancer cell hues in the National Cancer Institute (NCI), USA 60-cell line assay. 

O Neill and coworkers have also sought to address the problem of the metabolically susceptible CIO acetal linkage . A series of CIO carba dimers were prepared and assayed for antitumour activity. The two most potent compounds that were prepared are two phosphate ester finked dimers 115 and 116 (Scheme 40). They are principally active against leukaemia, colon and certain melanoma and breast cancer cell lines in the NCI 60-cell line assay. 

The estrogenic and antiestrogenic activities of several PBDE congeners and three hydroxylated PBDEs were tested in vitro using human breast cell line assays based on estrogen receptor (ER)-dependent luciferase reporter gene expression (Mccrts et al. 2001). The hydroxylated PBDEs,... 

This as yet unidentified plant has yielded a small amount of a potently active compound in the 1138 yeast bioassay this has been submitted to the National Cancer Institute for bioassay in the 60-cell line assay. The active material has been identified as the known alkaloid cryp-tolepine (30) cryptolepine had an IC50 value of 5.8 fig/ml in the M109 cytotoxicity assay. 

The cytotoxicity of taxoids 40-i and 40-S bearing the oxanorstatine residue were evaluated in our standard five human cancer cell line assay.71 As Table 7 shows, these two stereoisomers were found to possess considerably different cytotoxicity, which is rather unexpected. Taxoid 40-R showed a 3- to 10-fold increase in activity as compared to paclitaxel, while the other isomer, taxoid 40-S, exhibited a 2- to 4-fold decrease in activity, i.e. one to two orders of magnitude difference in activity is observed just by changing the stereochemistry of the epoxide moiety at C-3. This... 

This type of test is called parallel-line assay and is based on the comparison of a sample response with that of a reference standard (Finney, 1978). In general, it determines the response - at least by duplicates - of a series of dilutions of each preparation (sample and standard) while plotting the means of their corresponding doses on a logarithmic scale. As this test requires analysis of a linear portion of the curves, at least three points of each curve belonging to such a portion should be selected. The more selected points, the better the comparison. 

Finney DJ (1978), Parallel line assays, In Statistical Methods in Biological Assays, Charles Griffin, London, pp. 69-104. 

Besides IgG (7S) and IgM (19S) production, tilorone was also found to elevate IgE levels. Using a parallel line assay, as described by Finney53, Megel eta/.3 found that tilorone elevated IgE-like antibody levels 3.2 times with relation to saline control. 

Mutagenicity studies using Ames Salmonalla assays have been negative studies of sister chromatid exchange and mouse lymphoma line assays have been positive. 

Reactions can be analyzed almost instantaneously through in-line analyses, i.e., by analyzing the reaction using a probe inserted into the reactor or a reactor stream. In-line assays may be used for analyzing reactions run in dedicated equipment, which is often the case in manufacturing, or to assay reactions that are difficult to assay by conventional external methods (see below). Relatively few analytical techniques have been adapted for in-line assay. 

Fourier-transform infrared spectroscopy (FTIR) and pH measurements are the techniques most often adapted for in-line IPC. pH measurements are used for reactions that are run in water or have an aqueous component, e.g., an aqueous extraction. FTIR is especially good for monitoring continuous reactions [12] and reactions that would be dramatically changed by exposure to the atmosphere and temperature of the laboratory. Suitable reactions include low-temperature reactions, reactions run under pressure, reactions with gaseous or toxic materials (e.g., ethylene oxide), and reactions run under inert atmosphere. Further advantages of in-line assays are that no samples need to be prepared, and assay results can be generated within minutes. 

The prediction of the important structural features that affect intestinal permeability is useful information to obtain early in the drug discovery process. The two most common models used to obtain fast, high-throughput measurements are the parallel artificial membrane permeation assay (PAMPA) and the cell line assays that feature cultured human colon adenocarcinoma cells (Caco-2). Each method uses a surrogate model to mimic intestinal absorption followed by LC-MS analysis. 

The use of the Caco-2 cell line assays provide more physiologically relevant data than the PAMPA assays since they express transporters so that both active and passive transport can be determined. Caco-2 cell monolayers are contained in a 96-well plate format and test compounds can be incubated to model and test absorption [85],... 

The result of a prior in-line assay is taken into account when deciding on the need for the determination of other parameters in the assayed sample. To this end, the result associated with the first analyte is compared with a pre-set threshold value specific for a given analytical problem and a binary answer (yes/no, present/absent, high/low) is obtained. Depending on the answer, other analytes may or may not be determined. A significant reduction in the total number of determinations is attained, thus expanding the analytical productivity of the laboratory. 

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