Identification animals

Historically, drug absorption, distribution, metabolism, excretion, and toxicity ADMET) studies in animal models were performed after the identification of a lead compound. In order to avoid costs, nowadays pharmaceutical companies evaluate the ADMET profiles of potential leads at an earlier stage of the development... 

Taxonomy The classification, nomenclature, and laboratory identification of organisms (Do not confuse with taxidermy - stuffing dead animals)... 

Hazard identification through animal experiments, epidemiological studies, or structure activity analyses... 

Hazard identification, step one, means identification of new chemicals or other factors that may cause harmful health effects. Previously, novel hazards were usually observed in case studies or after accidents or other excessive exposures, usually in occupational environments. Today, thorough toxicity studies are required on all pesticides, food additives, and drugs. New chemicals also have to be studied for their potential toxic effects. Thus, earlier hazards were in most cases identified after they had caused harmful effects in humans. Today, most chemical products have been evaluated for their toxicity with experimental animals. Therefore, hazard identification has become a preventive procedure based on safety studies conducted before a chemical compound or product reaches the market, and before individuals are exposed to it. ... 

Hazard identification is defined as tlie process of determining whetlier human exposure to an agent could cause an increase in the incidence of a health condition (cancer, birtli defect, etc.) or whetlier exposure to nonliumans, such as fish, birds, and otlier fonns of wildlife, could cause adverse effects. Hazard identification cliaracterizes tlie liazard in terms of tlie agent and dose of the agent. Since tliere are few hazardous chemicals or hazardous agents for wliich definitive exposure data in humans exists, tlie identification of health hazards is often characterized by the effects of health hazards on laboratory test animals or other test systems. ... 

These iiicchanisnis can affect the near-term and ultimate fate of a chemical hazard. Recognition of these inechanisms can significantly assist in the identification of a chemical agent as a health hazard. In recent years, the understanding of chemical transport, chemical manipulation in the body, and response by animals luid humans to cheniicals has advtmccd to a point where it is possible to determine whether a chemical is indeed a health hazard. 

Methyl-heptenone also forms a bromine derivative which is well suited for the identification of the ketone. This body, which has the formula CgHjjBrgO. OH, melts at 98° to 99°, and is obtained as follows Three grams of methyl-heptenone are mixed with a solution containing 3 grams of caustic soda, 12 grams of bromine, and 100 c c. of water. After a time an oily substance is deposited, which is extracted with ether. The solvent is evaporated, and the residue, redissolved in ether, is treated with animal charcoal and filtered. On slow evaporation the product is obtained in well-defined crystals. 

This system for keeping track of these important units is used as the basis for the standard geologic lime and the evolution of the animal life on earth. (See also Tables 2-26 and 2-27.) Table 2-28 gives the relationship between geologic time and important physical and evolutionary events that are used to aid in the identification of rock units in relative geologic time [26]. 

A new coronavirus was quickly identified after the outbreak of an atypical pneumonia in southern China early in 2003. The new virus eventually caused 8,000 infections with approximately 800 deaths in 29 countries. The condition was named Severe Acute Respiratory Syndrome, SARS, and the causative coronavirus named SARS-CoV. The zoonotic nature of the infection came with the identification of a similar virus in bats (Poon et al. 2005), although it is possible that the bat virus passed through other animal hosts and recombined with other SARS-like coron-aviruses prior to infecting humans (Hon et al. 2008). SARS-CoV is not currently circulating in the human population however, the mysterious appearance and rapid spread of this virus emphasized how vulnerable the human population is to such respiratory infections. This has spurred interest in the development of antivirals that could be used either in treatment or as prophylaxis to complement public health measures in curbing future outbreaks. 

For chemicals in general the identification of a potential hazard normally arises from the application of in vitro tests or from short-term toxicity studies undertaken in laboratory animals (up to a period of 90 days in the case of the rat where the test material normally should not exceed 1% of the total diet). This usually enables a critical effect to be assessed. 

The second pathway is the eccentric cleavage that occurs at double bonds other than the central 15,15 -double bond of the P-carotene molecule to produce different products called P-apocarotenals with various chain lengths. Because only trace amounts of apocarotenals were detected in vivo from tissues of animals fed P-carotene and these compounds can be formed non-enzymatically from P-carotene auto-oxidation, the existence of this pathway was controversial until recently. The identification of P-carotene 9, 10 -oxygenase (BC02), which acts specifically at the 9, 10 double bond of P-carotene to produce P-apo-lO -carotenal and P-ionone, provided clear evidence of the eccentric cleavage pathway in vivo. Lycopene was also reported as a substrate for BC02 activity. 

NOAEL (no-observed-adverse-effect level) is defined as the highest dose at which no adverse effects are observed in the most susceptible animal species. The NOAEL is used as a basis for setting human safety standards for acceptable daily intakes (ADIs), taking into account uncertainty factors for extrapolation from animals to humans and inter-individual variabilities of humans. The adequacy of any margin of safety or margin of exposure must consider the nature and quality of the available hazard identification and dose-response data and the reliability and relevance of the exposure estimations. In some cases, no adverse endpoint can be identified such as for many naturally occurring compounds that are widespread in foods. In that case, an ADI Not Specified is assigned. ... 

The degree of confidence in the final estimation of risk depends on variability, uncertainty, and assumptions identified in all previous steps. The nature of the information available for risk characterization and the associated uncertainties can vary widely, and no single approach is suitable for all hazard and exposure scenarios. In cases in which risk characterization is concluded before human exposure occurs, for example, with food additives that require prior approval, both hazard identification and hazard characterization are largely dependent on animal experiments. And exposure is a theoretical estimate based on predicted uses or residue levels. In contrast, in cases of prior human exposure, hazard identification and hazard characterization may be based on studies in humans and exposure assessment can be based on real-life, actual intake measurements. The influence of estimates and assumptions can be evaluated by using sensitivity and uncertainty analyses. - Risk assessment procedures differ in a range of possible options from relatively unso-... 

Barlow, S.M. et al.. Hazard identification by methods of animal-based toxicology. Food Chem. Toxicol, 40, 145, 2002. 

A novel TLC spectrofluorometric method for identification and determination of selenium in different food samples of animal and vegetable origin has been proposed [30]. The procedure involves the digestion of food sample (1 to 5 g) in the presence of cone. HNO3 (5 ml), 70% HCIO4 (10 ml), and FIjO (10 ml) in a 250-ml Kjeldahl flask reduction of Se(VI) into Se(IV) complexation of the isolated selenium with 23-diaminonaphthene (DAN) extraction of the resultant Se—DAN complex with cyclohexane and spectrofluorometric determination followed by confirmation of the presence of Se in the sample by TLC using thin layers of MN-300 cellulose powder. 

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