Susceptibility 1116 Subject

The AEGL-1 values were based on concentrations at 0.5 ppm and 0.1 ppm, which were the thresholds for mild headaches in healthy individuals at exposure durations of 1 and 6 h, respectively (Stewart et al. 1974). This effect can be considered the threshold for mild discomfort (only one subject was affected at each exposure), which falls within the definition of an AEGL-1. The 0.5-ppm concentration was used to derive the 30-min and 1-h AEGL-1 values, and the 0.1-ppm concentration was used for the 4- and 8-h values. Because the time and concentration values were based on the most susceptible subject, these concentrations were adjusted by an uncertainty factor (UF) of 3 to account for potential differences in human sensitivity and scaled to the appropriate time periods using the C xt=k relationship. A UF of 3 was considered sufficient as no susceptible populations were identified (the headache effect is the same as that experienced by patients medicated with nitro... 

Varicella vaccine produces an attenuated clinically inapparent varicella infection in susceptible subjects. 

Other dissociations are the altered states of consciousness seen in hypnosis and hysteria that have been likened to sleepwalking. The word somnambulism denotes not only sleepwalking per se, it also denotes those hypnotic trance states that impose a kind of sleepiness on susceptible subjects during waking. For Pierre Janet (and for Charcot, Freud, and the rest), this was the very essence of dissociation. The psychoanalytic model ascribed the same repressed libidinal wishes to the hypnotic somnambulist that it found to be the root cause of all dreaming. The fact of the matter is that any coordinated behavior is likely to invite the ascription of motive. If the subject is unconscious or nonconscious, then the motive must be unconscious too. 

Other BAs, such as putrescine (Put), cadaverine (Cad), tryptamine (Try), /3-phenylethyl-amine (Phe), spermine (Spm), and spermidine (Spd), have been described as potentiators that enhance the toxicity of His (21,22) likewise, Tyr and Phe are thought to precipitate migraine attacks in susceptible subjects (23). 

Progestogens with a degree of mineralocorticoid activity will tend to cause water and salt retention and to increase blood pressure in susceptible subjects. However, effects on blood pressure can be variable for example, medroxyprogesterone has been variously reported to cause a fall in blood pressure in some initially hypertensive patients while rapidly increasing diastolic pressure in some other women, or to have no effect on blood pressure at all. 

Factors that may have contributed to this metabolic acidosis included low birth weight, renal tubular immaturity, and impaired renal function, which may have resulted in systemic accumulation with repetitive dosing. This case stresses the fact that topical medications can cause systemic effects if a sufficient amount of drug is absorbed in a susceptible subject. 

Most diuretics cause hyperuricemia. Increased reabsorption of uric acid (along with other solutes) in the proximal tubule as a consequence of volume depletion is one reason however, diuretics also compete with uric acid for excretory transport mechanisms. There is a small increased risk of acute gout in susceptible subjects (73). In the large outcome trials, about 3-5% of subjects treated with diuretics for hypertension developed clinical gout... 

Aortic and mitral valvular fibrosis can lead to congestive cardiac failure fibrosis rarely affects the endocardium more extensively (extending into the myocardium) or the pericardium (resulting in constrictive pericarditis). Vasospastic effects can occasionally be as severe in susceptible subjects as with ergotamine especially dangerous are combinations with ergotamine tartrate, as are combinations of ergot alkaloids with beta-blockers (SEDA-9,128). 

Since salbutamol and its congeners are not entirely selective in their beta2-stimulating action, they retain some stimulant effects on the heart, central nervous system, and carbohydrate and fat metabolism these only become troublesome with relative overdosage or in particularly susceptible subjects. Adverse effects occur through stimulation of extra-pulmonary beta2-adrenoceptors they consist of ... 

As discussed above, hthium inhibits the synthesis of thyroid hormone and its release from the thyroid, and stimulates the formahon of antithyroid anhbodies in susceptible subjects [122]. Lithium-induced hypothyroidism responds to thyroxine therapy. Lithium... 

Shomers et al. [96] cited the large variation in individual samples of submandibular-sublingual saliva as the reason for their finding of a similar average content of cysteine-rich phosphoproteins in groups of caries-resistant and caries-susceptible subjects. 

Of interest, lipid-containing pellicle was less permeable to lactic acid diffusion in vitro than lipid-depleted pellicle and pellicles from caries-resistant subjects were less permeable than pellicles from caries-susceptible subjects [102], These observations suggest a possible protection mechanism against caries without highlighting the particular lipids responsible. Other studies have indicated that lipids adversely affect the association of calcium with salivary glycoprotein [105]. It has also been speculated that because lipids modify the hydrophobic nature of the pellicle, they may facilitate bacterial adhesion [102,105],... 

Few studies have investigated links between salivary enzymes and caries or calculus. Neither Ruan et al. [97] nor Stuchell and Mandel [114] could find differences in lysozyme levels between caries-resistant and caries-susceptible subjects. On the other hand, Mandel [84] found significantly less lysozyme in submandibular saliva from heavy calculus-formers than from non-calculus formers, and a similar trend in acid phosphatase level was almost significant. Mandel speculated that lysozyme, by its interaction with cell walls [106], might modify initial calcification processes. 

Fig. 15.3 Biofilm (plaque) pH in caries-resistant and caries-susceptible subjects. The pH decreased and returned to initial values more rapidly following a 10% sucrose rinse in caries-resistant subjects (o) than in caries-susceptible subjects ( ). Each group had five subjects (Figure 2 in Mandel and Zengo (1973) Genetic and chemical aspects in caries resistance. Comparative immunology of the oral cavity, ed. H. Scherp and S. Mergenhagen, pp. 118 - 137, US Government Printing Office)...

Porphyria maybe classified as hepatic or erythropoietic. However, enzyme defects are sometimes common to both tissues. Porphyrias can be induced by alcohol, stress, infection, starvation, hormonal changes (e.g., menstruation), and certain drugs. These drugs presumably precipitate acute manifestations in susceptible subjects since they are inducers of cytochrome P-450 and increase the need for synthesis of heme as they deplete the mitochondrial pool of free heme. Major hepatic porphyrias include acute intermittent porphyria, variegate porphyria, hereditary coproporphyria, and porphyria cutanea tarda. The principal erythropoietic porphyrias are hereditary erythropoietic porphyria and erythropoietic protoporphyria. 

It is normally assumed that the magnetic susceptibility subjected to analysis (fitting procedure) has already been corrected for the underlying diamagnetism and eventually for the temperature-independent paramagnetism, so that that quantity is the net temperature-dependent paramagnetic susceptibility. 

The sulfonamides are as efficacious as oral penicillin in preventing streptococcal infections and recurrence of rheumatic fever in susceptible subjects and are used in patients who are hypersensitive to penicillin. Untoward responses usually occur during the first 8 weeks serious reactions after this time are rare. White blood cell counts should be checked weekly during the first 8 weeks. 

The beneficial effects of iodine supplementation in the prevention and control of developed thyroid abnormalities due to iodine deficiency have been discussed so far in this chapter. However, supplementation with excess iodine, including the improvement of a previous iodine-deficient state, may cause thyroid dysfunctions, viz., iodine-induced hypothyroidism/iodide goiter in susceptible subjects (Roti and Vagenakis, 2000) and iodine-induced hyperthyroidism (IIH) especially in individuals over 40 years of age and who have been iodine deficient for a long period in the past (Vidor et ai, 1973). It may also increase the ratio of papillary/follicular carcinomas (Slowinska-Klencka et ai, 2002). In other words, both low and excess intake of iodine is related to further risk of thyroid disease. Although a daily intake of up to 1000 pg/day by a normal adult individual is quite safe (WHO, 1994), the upper limit is much lower in a population that has been exposed to iodine deficiency in the past. Therefore, to prevent IDD, the recommended iodine requirement in an adult individual is fixed within a narrow range of 150 rg/day (Knudsen et ai, 2000). Iodine supplementation under certain conditions in certain populations causes adverse effects, e.g., iodide goiter and iodine-induced hypothyroidism, IIH, iodine-induced thyroiditis and thyroid cancer. 

The thyroid gland seems to be well adapted to incidents of iodine intake in very high amounts. Still, there is evidence showing that increased intake of iodine may induce clinically relevant problems in some susceptible subjects. These effects are optimally identifiable at population level, as individual responses vary depending on many other factors that are difficult to control. One of the main undesirable consequences of increased iodine intake in a population is a higher incidence of hyperthyroidism. This chapter discusses the epidemiology and etiology of iodine-induced hyperthyroidism (IIH), which follows normalization of iodine supply. 

Increased iodine intake may induce clinically relevant disturbances in some susceptible subjects. 

In contrast to inhalation of capsaicin and citric acid, inhalation of UNDW may be associated with clinically-significant bronchoconstriction in susceptible subjects (Fontana et al. 2005). Thus, a heightened level of vigilance is required during the performance of fog challenge studies. 

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