Adverse effect, definition

A phase-3 assessment of the accuracy of Levovist (SHU508A, Schering, Berlin) in investigating the portal system has been reported (8). It was injected into peripheral veins in 588 patients in concentrations of 200-400 mg/ml. During the 24 hours after the last injection, pain at the site of injection, vasodilatation, and paresthesia were the only adverse effects definitely related to the injection. There were 18 adverse events in 12 patients and the only severe reaction (fever) was not considered to have been related to Levovist. 

In cases where an adverse effect was confirmed, a definite, causative link with exposure to an environmental chemical or chemicals needed to be established. 

A major difficulty which has been encountered with these definitions (identified as a particular problem by EDSTAC) is the definition of the term adverse . For a chemical to be judged an ED, it is important to show that the response seen has an adverse effect on the health or reproductive capacity of affected organisms or populations and is not just a change which falls within the normal range of physiological variation. 

Compatibility. Clear definition of compatibility is rather difficult. Compatibility has been defined as the ability of two or more materials to exist in close and permanent association for an indefinite period without phase separation and without adverse effect of one on the other [28]. On the other hand, compatibility is easily recognized in solvent-borne adhesives as a homogeneous blend of materials without phase separation. Normally, compatibility is understood as a clear transparent mixture of a resin with a given polymer. But, compatibility is a more complex thermodynamic phenomenon which can be evaluated from specific... 

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. ... 

Wheat bran has been the fiber source most commonly used to study effects of dietary fiber on calcium absorption in controlled laboratory studies. However, wheat bran and other forms of fiber as they occur in food products present several disadvantages in terms of definition and by concurrently altering intakes of other substances or materials known or suspected of having an adverse effect on the bioavailability of calcium such as phytates and oxalates (5,13,17,22-28). Several studies have been conducted which have sought to separate or compare the effects of phytate and fiber... 

Claims are what is said in labeling and advertising, and may be either of a positive (therapeutic or beneficial) or negative (lack of an adverse effect) nature. The positive or efficacy claims are not usually the direct concern of the toxicologist though it must be kept in mind that such claims both must be proved and can easily exceed the limits of the statutory definition of a device, turning the product into a drug or combination product. 

Biological definition The dose, below which the organism does not suffer from any (adverse) effects from the compound considered. 

For continuous data, there are still a number of outstanding issues regarding the benchmark including (Crump 2002) (1) definition of an adverse effect (2) whether to calculate the BMD from a continuous health outcome, or first convert the continuous response to a binary (yes/no) response (3) quantitative definition of the BMD, in particular in such a manner that BMD from continuous and binary data are commensurate (4) selection of a mathematical dose-response model for calculating a BMD (5) selection of the level of risk to which the BMD corresponds and (6) selection of a statistical methodology for implementing the calculation. 

A general definition of the term acute toxicity is The adverse effects occurring within a given time, following a single exposure to a substance. The term usually excludes local irritant or corrosive effects arising from a single application of a substance to the skin or eye (Section 4.5) (EC 2003). 

According to the definitions provided in the OECD test guidelines (TG 420 and 423), acute oral toxicity refers to those adverse effects that occur following oral administration of a single dose of a substance or multiple doses given within 24 h. 

In the test guidelines for 90-day dermal (OECD TG 411) and inhalation (OECD TG 413) toxicity studies, the following definition in relation to the term subchronic is provided Subchronic dermal/inhalation toxicity is the adverse effects, which follow repeated daily dermal application/ inhalation of a chemical for part (not exceeding 10%) of a life span. ... 

In the test guidelines for chronic toxicity (OPPTS 870.4100, 870.4300), the following definition is provided Chronic toxicity is the adverse effects occurring as a result of the repeated daily exposure of experimental animals to a chemical by the oral, dermal, or inhalation routes of exposure. The guidelines request an exposure period of at least 12 months. The preferred species is the rat. 

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