Insult

The foregoing is an equilibrium analysis, yet some transient effects are probably important to film resilience. Rayleigh [182] noted that surface freshly formed by some insult to the film would have a greater than equilibrium surface tension (note Fig. 11-15). A recent analysis [222] of the effect of surface elasticity on foam stability relates the nonequilibrium surfactant surface coverage to the foam retention time or time for a bubble to pass through a wet foam. The adsorption process is important in a new means of obtaining a foam by supplying vapor phase surfactants [223]. 

The biological response to chemical insult may take numerous forms, depending on the physicochemical properties of the material and the conditions of exposure. Listed below are some of the more significant and frequendy encountered types of injury or toxic response they may be defined in terms of tissue pathology, altered or aberrant biochemical processes, or extreme physiological responses. 

Extrinsic Pathway. Coagulation is initiated when tissue extracts with Hpid—protein properties are released from the membranes of endothehal cells following injury or insult. These substances, collectively designated tissue thromboplastin, complex with circulating Factor VII and in the presence of calcium ions subsequentiy activate Factor X (Fig. 1). In vitro evidence suggests that Factor X can be activated less rapidly through the interaction of kaUikrein [9001-01-8] with Factor VII. 

Vision is vital for human activities, and eyes are very sensitive to a number of toxic insults induced by chemical compounds. The most serious outcome is permanent eye damage which may be so severe as to cause loss of vision. The eye consists of the cornea and conjunctiva, the choroid, the iris, and the ciliary body. It also contains the retina, which is of neural origin, and the optic nerve. The retina contains photoreceptors, a highly specific light-sensitive type of neural tissue. The eye also contains the lens and a small cerebrospinal fluid system, the aqueous humor system, that is important for the maintenance of the steady state of hydration of the lens and thus the transparency of the eye. 

Hands - metal mesh gloves, fire resistant gloves, and insulted gloves... 

The definition above has replaced older ones that focused to varying degrees on chronic bronchitis and/ or emphysema. Chronic bronchitis and emphysema frequently represent different consequences of the same insult leading to changes in large aiiways, small airways and pulmonary parenchyma (Table 1). 

Several glutamate antagonists have been or are in the process of being evaluated both preclinically and clinically as neuroprotective agents. For example, MK-801, an NMDA antagonist, reduces the detrimental effects of excess glutamate (as well as other insults to neurons) in a variety of animal models. Unfortunately the... 

Although methods have been established to derive these levels (Barnes and Dourson 1988 EPA 1990c), uncertainties are associated with these techniques. Furthermore, ATSDR acknowledges additional uncertainties inherent in the application of the procedures to derive less than lifetime MRLs. As an example, acute inhalation MRLs may not be protective for health effects that are delayed in development or are acquired following repeated acute insults, such as h q)ersensitivity reactions, asthma, or chronic bronchitis. As these kinds of health effects data become available and methods to assess levels of significant human exposure improve, these MRLs will be revised. 

Schmidt RR. 1984. Altered development of immunocompetence following prenatal or combined prenatal-postnatal insult A timely review. J Am College Toxicol 3 57-72. 

Cohort Study—A type of epidemiological study of a specific group or groups of people who have had a common insult (e.g., exposure to an agent suspected of causing disease or a common disease) and are followed forward from exposure to outcome. At least one exposed group is compared to one unexposed group. 

Embryotoxicity and Fetotoxicity—Any toxic effect on the conceptus as a result of prenatal exposure to a chemical the distinguishing feature between the two terms is the stage of development during which the insult occurs. The terms, as used here, include malformations and variations, altered growth, and in utero death. 

Blood vessels were congested and cardiac ventricles were distended with blood in rats that died as the result of a 6-hour/day, 5-day/week for 30-day exposure to 81 mg/kg/day (males) and 27 mg/kg/day (females) (Hoechst 1985c). However, it is unclear whether these effects were due to a direct action of endosulfan on the blood vessels and heart or were a result of a more general toxic insult (e.g., convulsions). The respective NOAELs for males and females were 27 and 9 mg/kg/day. 

Neuropsychiatric diseases Hyperventilation Panic fear attacks Globus hystericus Anaphylaxis factitia Hoigne syndrome Epileptic cramps Apoplectic insult... 

The maintenance of the integrity of the information in DNA molecules is of utmost importance to the survival of a particular organism as well as to survival of the species. Thus, it can be concluded that surviving species have evolved mechanisms for repairing DNA damage occurring as a result of either replication errors or environmental insults. 

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