Cumulative action

Concentrations lethal to humans are not expected to be encountered at room temperature because of the low volatility of cumene. If inhalation of high concentrations of the vapor did occur, dizziness, incoordination, and unconsciousness could be expected. In animals, cumene narcosis is characterized by slow induction and long duration, suggesting a cumulative action. There are no reports of systemic effects in humans. 

Dosage titration - Because of cumulative action, initiate therapy with a low dose, increase in increments of 0.5 mg gradually at 5 or 6 day intervals to the smallest amount necessary for optimal relief. Maximum daily dose is 6 mg. 

The effect of many drugs used to treat cancer also reflects a cumulative action—eg, the extent of binding of a drug to DNA is proportional to drug concentration and is usually irreversible. The effect on tumor growth is therefore a consequence of cumulative exposure to the drug. Measures of cumulative exposure, such as AUC, provide a means to individualize treatment. 

Early experience also showed that the induced plasma current in a tokamak generates a magnetic field that loops die minor axis nf Ihe torus. The field lines form helices along the toroidal surface the plasma must cross the lines to escape. It does so through the cumulative action of many random displacements caused by interparticle collisions, tin effect diffusing across the field lines and out of the system). Thermal energy is transported by much the same process. 

There are several important comments to be made on this North American recreation-based work. At the broadest level wilderness settings and natural environments are just one kind of tourist-tourist context and even within such an environment categorisation there are many variations. Recreational conflict appears to be particularly noticeable when the specific focused purposes of one group are frustrated by the cumulative actions of another. By way of contrast, in many tourist situations there are shared goals. The visitors in the setting have come to see, experience and enjoy the same features and activities. In this kind of scenario the tolerance for fellow visitors may be quite high. 

QUANTITATIVE INHERITANCE Inheritance of a characteristic (e.g., height in man and milk production in cattle) that depends on the cumulative action of many genes, each of which produces a small effect. (See also ADDITIVE FACTOR)... 

Acrylonitrile closely resembles hydrocyanic acid in its toxic action. By inhibiting the respiratory enzymes of tissue, it renders the tissue cells incapable of oxygen absorption. Poisoning is acute there is little evidence of cumulative action on repeated exposure. Exposure to low concentration is followed by flushing of the face and increased salivation further exposure results in irritation of the eyes and nose, photophobia, deepened respiration. If exposure continues, shallow respiration. 

DOT CLASSIFICATION 4.3 Label Dangerous When Wet SAFETY PROFILE Poison by ingestion, inhalation, skin contact, intravenous, and intraperitoneal routes. Moderately toxic to humans by ingestion. Questionable carcinogen with experimental tumorigenic data. Mutation data reported. The fatal dose, by ingestion, is probably around 20 to 30 g for an adult. It does not have a cyanide effect. Calcium cyanamide is not believed to have a cumulative action. Flammable. Reaction with water forms the explosive acetylene gas. When heated to decomposition it emits toxic fumes of NOx and CN". See also CALCIUM COMPOUNDS, AMIDES, and CYANIDE. 

Thiomalate (salt of ester of the malic acid) also has been used very successfully to treat severe cases of rheumatoid arthritis. A complete cure or a significant improvement has been noted in approximately 50% of patients using this treatment modality, with 40% of patients exhibiting side effects. Thiomalate is also toxic and possesses cumulative action. Minimal concentrations of the gold compounds reach many cells and remain in the body for years. ... 

A further advance in the use of pulse technique is the spin echo method (Hahn, 1950 Waugh et al., 1968 Mehring, 1978 Emerson and Bray, 1993). Briefly in this technique, a 90 pulse is applied at t = to- 90 pulse is that for which Op = 7112. This causes an induction, which then dephases and begins to decay. After a time r, a 180 pulse is imposed, which now rotates the spins by 180 . As a consequence, the same mechanism which was responsible for dephasing of spins in the xy plane, now acts to rephase the spins. After a time interval of 2r, a spin echo is formed. The spin echo therefore represents cumulative action of two FIDs taking place from opposite directions. The FT of the second half of the spin echo gives the absorption spectrum. 

Cumulative action of chemical cross-linking and catalytic dehydration presents arise a necessary and sufficient condition of carbonization, which is observed in the process of thermal-oxidative degradation of PE-MMT nanocomposites. 

Pentaborane is considered to be the most toxic boron hydride in the case of inhalation. Inhalation exposures of small laboratory animals showed values of LDjq of 9 to 46 mg m. It exerts particularly a cumulative action on the central nervous system, accompanied by tremor and cramps. Chronic exposures (for 6 months) to vapours at a concentration of 2.5 mg m resulted in an insufficient oxygen supply to tissues (anoxia), decreases in the body weight, apathy and tremor. Dissection demonstrated no serious pathological changes [77]. The chronic exposures of animals can lea4 to damage to the liver and kidneys [80]. 

The racemic a-acetylmethadol (dZ-6-dimethylamino-4,4-diphenyl-3-acetyoxyheptane) has been studied clinically by David and Sender (93). When the racemic dZ-a-acetylmethadol was administered oraUy or subcutaneously to hospitalized patients, the average daily dose required to control pain adequately was 20-30 mg. given either in 5 mg. doses four or five times daily or 10 mg. two or three times daily. Some cumulative action... 

Being water-soluble, barbital sodium is more readily absorbed than its parent eompound barbital. Owing to its slow rate of excretion there exists an element of risk of a cumulative action. 

Reserpine has been used in the management of mild to moderate hypertension, but because of very significant CNS adverse effects and its cumulative action in the adrenergic neurons, reserpine is rarely used. Reserpine and related Rauwolfia alkaloids have been used in the symptomatic treatment of agitated psychotic states, such as schizophrenic disorders, although other antipsychotic agents generally have replaced reserpine and the alkaloids. 

Individual exposure depends on a cumulative action from various sources such as worlqtlace exposure, amounts of substance contained in water, air, indoor euviromneiit (as a consequence of use of various products by constmction and maintenance), food products, food packaging, household products, and cosmetics. The total exposure should not exceed the above values. 

Kagan YS, Stankevich VV (1964) Cumulation coefficient as quantitative criterion for evaluation of cumulative action of toxicant. In Current Problems of Work Hygiene, Industrial Toxicology and Occupational Diseases in Petroleum and Petrochemical Industries, pp 48-49. 

The major factor in skin diseases caused by exogenous substances is the repeated and cumulative action on the skin of agents in weak irritant solutions. The repeated exposure to surfactants represents a model for the induction of ICD (Tupker et al. 1989a). During the course of the exposure (patch test applied twice daily for 3 weeks), a progressively damaging clinical effect accompanied by an increase in TEWL (due to a cumulative action of these agents on the skin) is observable. 

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