Guinea pig assay

In guinea pig assays for skin sensitization, 4 of 5 tested mineral oil hydraulic fluids (Pyroguard A-443, Sunsafe F, Houghto-Safe 5047F, and MIL-H-5606) displayed no activity the remaining fluid,... 

Species guinea pig Assay maximization test Result strong... 

Standardized validating predictive assays in mice have been developed in the last 10 years. LLNA as one of such assays offers advantages in the low number of animals used, lower cost, and less time required for conducting the assay in comparison to various guinea pig assays. 

Weaver, J.L., Staten, D., Swarm, J., Armstrong, G., Bates, M., Hastings, K.L. (2003). Detection of systemic hypersensitivity to drugs using standard guinea pig assays. Toxicology 193 209-17. 

There are several acceptable ways to evaluate DTH responses in nonclinical species. Of these, the most common are the guinea pig assays used to assess contact sensitization. Both the Magnusson and Kligman model (guinea pig maximization test) and the Buehler model measure the elicitation phase of the hypersensitivity response, though the tests vary in their methods of chemical application and utilization of adjuvants. Most recently, the local lymph node assay has been accepted as a stand alone test for chemical hypersensitivity. This assay is conducted in mice and measures the induction phase of sensitization. In humans, the most common methods to assess delayed hypersensitivity are the patch test (contact sensitivity for diagnostic purposes) and the human repeat insult patch test (contact sensitivity for predictive purposes). Additionally, intradermal... 

Muchowski recently reported -ll-deoxy-lla,12a-difuoro-methylene-PGE2 (HI) to have 5x the potency of I-PGE2 in a guinea pig assay (histamine agonist) when administered by aerosol, and to be equipotent when administered by the intravenous route (126,127). The 13,14-dihydro derivative IV was similarly active, as were the and Eq counterparts. Interestingly, the lla,12a-methylene analogs were essentially inactive. In a clinical trial with mildly asthmatic patients neither III or IV were sufficiently effective to be of interest (126). 

All estimates of relative potency whether obtained from chemical or biological methods of assay are derived by equating those quantities which produce an equivalent effect and will depend on the calculation of a ratio or a difference. The assay of digitalis in which the individual lethal doses of standard or test preparation are equated provides a practical example of the use of both these treatments. In the U.S.P. pigeon assay the actual lethal doses are used to calculate the relative potency as a ratio. In the B.P. guinea pig assay their logarithms are used. The application of both these treatments to results obtained in the conduct of a B.P. assay will be illustrated. 

Research lea ding to the discovery of vitamin C began in 1907 when it was observed by Axel Holst and Theodor Ern hlich that guinea pigs were as susceptible to scurvy as humans and that the disease could be produced experimentally in these animals (8). These findings led to the development of an assay for the biological deterrnination of antiscorbutic activity of food products (9). 

Enslein K, Gombar VK, Blake BW, Maibach HI, Hostynek JJ, Sigman CC et al. A quantitative structure-activity relationships model for the dermal sensitization guinea pig maximization assay. Food Chem Toxicol 1997 35 1091-8. 

Assay of Endogenous NE. Endogenous NE release from the guinea pig vas deferens was measured by means of a high pressure-liquid chromatograph with an ODS column and an electrochemical detector as described previously (16). 

Anthrax Medium from cuitures of B. anthracis 1 Separation of protective antigen from medium 2 Adsorption 3 + 3 quantal assay in guinea-pigs using challenge with B. anthracis Exclusion of live 6. anthracis and of anthrax toxin... 

Diphtheria (adsorbed) Cultures of C. diphtheriae in liquid medium 1 Separation and concentration of toxin 2 Conversion of toxin to toxoid 3 Adsorption of toxoid to adjuvant 3+3 quantal assay in guinea-pigs using intra-dermal challenge Inoculation of guinea-pigs to exclude residual toxin... 

Tetanus (adsorbed) Cultures of Cl. tetani in liquid medium 1 Conversion of toxin to toxoid 2 Separation and purification of toxoid 3 Adsorption to adjuvant 3 + 3 quantal assay in mice using subcutaneous challenge with tetanus toxin Inoculation of guinea-pigs to exclude presence of untoxoided toxin... 

When assayed in HEK293 cells transfected with the cloned human, rat and guinea pig TRPVl, (23a) showed similar potencies. Not unexpeetedly, (23a) showed poor metabolic stability and a structure-activity study to optimize potency and drug-like properties was initiated. Modification on the left-handed A -aryl section showed that ... 

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