Susceptible groups individuals

Differential susceptibility of individual clones of eastern white pine to ozone and sulfur dioxide was shown by Berry and Heggestad and Costonis. When Dochinger et a/. determined that chlorotic dwarf could be caused by an interaction of ozone and sulfur dioxide, th used a chlorotic dwarf-susceptible clone to eliminate the genotype variable. Houston tested the response of tolerant and susceptible clones of eastern white pine (on the basis of symptom expression under ambient conditions) to ozone or sulfur dioxide. Injury caused by sulfur dioxide or sulfur dioxide plus ozone correlated well with the earlier field responses, but ozone did not produce a consistent response. They also found that a 6-h exposure to a mixture of sulfur dioxide and ozone caused a difference in needle elongation between clones within tolerant and sensitive groups. This suggests that tolerance may function over a wide range of responses. 

In fact, a beneficial effect on the emissions of NO has been attributed to MMT (Lynam etal. 1999). By contrast, several reports have shown that roadside air, soils, plants and animals are contaminated by elevated Mn concentrations (Thibault etal. 2002 Zayed etal. 1999). Consequently, Frumkin and Solomon (1997) concluded that especially susceptible groups of the population (fetuses, infants, children, pregnant and nursing women, the elderly people, individuals with pre-existing neurological... 

In a study of the infrared spectral characteristics of human whole stimulated saliva collected from individuals classified as to dental caries status, a correlation was found between absorption bands at 1389 and 833 cm", and the caries status of 398 airmen of the U.S. Air Force (Harris et al., 1959). Also flow rate and these infrared bands were directly correlated. In order to reinforce such presumptive evidence that the characteristics of the infrared curves might be an indicator of caries-susceptibility status, a series of infrared studies of the saliva of normally caries-resistant rodents and other animals was done and the results were compared with the composite curves of previous human caries-resistant and caries-susceptible groups (Harris et ai, 1960). Included in the study were pilocarpine-stimulated salivary specimens of the rat, hamster, rabbit, cat, dog, and monkey. The spectra for all experimental animals within the same species were identical. The spectra of the saliva among the... 

Unusually susceptible populations are those groups of individuals who respond more quickly or at lower exposure levels than the general population to the toxic effects of methyl parathion. These responses may be genetic in origin or may be due to differences in development or life style factors such as nutrition or behavior, or due to preexisting disease states. 

Prevention of vascular disease is one of the goals of a study in progress in Sweden, in which newly diagnosed diabetic children have been randomized in a doubleblind study where one group receives placebo and the other a preparation containing ascorbic acid, )3-carotene, nicotinamide, selenium and vitamin E (Ludvigsson, 1992). Future research with antioxidants may attempt to prevent the onset of pancreatic beta-cell destruction in the prediabetic phase of susceptible individuals. 

No population has been identified which is unusually susceptible to toxic effects resulting from -hexane exposure. It is possible that individuals with diminished peripheral nerve function may be more susceptible to w-hcxanc neurotoxicity than the general population. This group would include diabetics, alcoholics and the aged. 

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