Sensitization geographic differences

The conditional stability constants found for the different marine areas are not very different. A trend can be observed of K increasing towards the open ocean. Thus relative stronger complexes are formed in the open ocean than in estuarine and coastal waters. Comparable values have been observed by other authors, using the same technique. Application of different techniques however, can result in several orders of magnitude higher K (Kramer, 1986). This cannot only be attributed to geographical differences. Another factor is, that different techniques have different sensitivities for the various species of the element concerned. 

Table 4. Geographic differences extreme (low and high) proportions of sensitization (standardized by age/sex) (%) of selected allergens in different dermatological departments (IVDK) in Germany and Austria (from Schnuch et al. 1997)...

Fisher, N.S., L.B. Graham, E.J. Carpenter, and C.F. Wurster. 1973. Geographic differences in phytoplankton sensitivity to PCBs. Nature 241 548-549. 

As part of the radon program at EML to develop or improve and field test radon monitors, a modified activated carbon device (Warner, 1986) was developed to obtain higher measurement sensitivity. As a result, we have surveyed 380 buildings in six states in the eastern United States. The purpose of the measurements reported in this paper was to test the feasibility of the new version of the passive activated carbon device and to obtain data on indoor radon levels in different geographical locations. 

The sensitivity of the antennal olfactory receptor system differs even between Colorado beetle populations (see Figure 5). The beetles of the field population in Wageningen are relatively more sensitive for cis-3-hexenyl acetate when tested than those of the laboratory stock culture. Beetles of the Utah population are relatively less sensitive for trans-2-hexen-1-ol and trans-2-hexenal than the individuals of the field population in Wageningen, and those insects obtained from the laboratory stock culture. The functional significance of these differences for the geographic variation in host plant range of this insect species needs further elucidation (21,22). 

Wheeler et al. (2002) established acute freshwater and saltwater SSDs for 21 substances, including ammonia, metals, several pesticides, and narcotic substances. Using HC5 calculations and curve slope, they found freshwater species were either more sensitive (ammonia, copper, nickel, or zinc) or less sensitive (chlordane, endosulfan, pentachlorophenol) than saltwater species. In some cases, the distributions were very similar however, the taxonomic compositions of the freshwater and saltwater data sets were not always comparable. Maltby et al. (2005) analyzed SSDs for 16 insecticides and inter alia compared SSDs based on saltwater and freshwater species. They concluded (page 379) that the taxonomic composition of the species assemblage used to construct the SSD does have a significant influence on the assessment of hazard, but the habitat and geographical distribution of the species do not. Differences in freshwater and saltwater SSDs were primarily driven by taxonomy (e.g., both crustaceans and insects are present in freshwater, but only crustaceans are found in seawater). Correcting for the disparity in taxonomy removed habitat differences. 

The problems of P-lactam and quinolone resistance in Neisseria gonorrhoeae are increasing, and selection of a particular drug will depend on sensitivity testing and a knowledge of resistance patterns in different geographical locations. Effective treatment... 

Prolonged paralysis can result from idiosyncrasy, overdose, or reduced or abnormal plasma cholinesterase activity. There are geographical and racial differences in sensitivity to suxamethonium (SEDA-6, 129) (95,96) some of these differences arise from dietary and other environmental factors and others result from variations in plasma cholinesterase genotypes. Genotypically normal patients may be paralysed by a usual (1 mg/kg) dose of suxamethonium for as short a time as 2 minutes or (rarely) as long as 20 minutes, and the duration in general inversely reflects plasma cholinesterase activity (97). 

Various parameters appear in the simple algebraic Eq. 1 for the frequency (proportion) of resistant weeds in a species that is preponderantly sensitive to a given herbicide. N is the very low frequency of resistant individuals in the population before it is exposed to the herbicide. In the absence of herbicide, resistance is sustained in the population by a balance between mutation and depletion of the proportion of resistant individuals by their lesser fitness in the absence of selection, resulting in a resistance fraction somewhat lower than the mutation frequency. If mutants were more fit than the wild type, they would be the wild type. Mutant fitness can be near neutrality, and the mutants would then be found in different proportions at various geographical areas due to drift". 

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