Sensitivity Between Foods

Cross-reactivity is also common between latex and a variety of foods, mostly fruits. Presentation may include cutaneous, urticaria, eczema, and dermatitis airborne—rhinitis, conjunctivitis, and asthma and mucosal leading to ana- 

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Systematically, allergy prevention can be directed into at least three potential strategies (1) primary prevention that inhibits IgE and other immunological sensitization, (2) secondary prevention that abrogates disease expression subsequent to immunological sensitization, and (3) tertiary prevention that suppresses symptoms after and despite disease expression (70). 

As in other allergic diseases, both patient factors and external factors contribute to fatal food-induced anaphylaxis (71). Patient factors include failure to inquire about ingredients in foods prepared by others, failure to appreciate the dose-response nature of food allergens, and denial or minimalization of symptoms based on previous nonfatal reactions. Patients may fail to carry or use injectable epinephrine or may mistakenly rely on oral antihistamine therapy for 

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As previously discussed, food effects are an important parameter for enteric-coated systems, especially for drugs, that are sensitive to food. Pancreatic enzyme-containing products fail when they come in contact too early with lipids, proteins, and carbohydrates present in food. The clinical efficacy of pancreatic enzymes formulated as enteric-coated tablets was investigated in man and dog [44], The enteric materials examined were hydroxypropyl methylcellulose phthal-ate (HPMCP), cellulose acetate phthalate (CAP), and the methacrylic acid copolymer USP/NF Type C. In vivo behavior monitored by x-ray scintigraphy showed clear differences between the three coating formulations. HPMCP-coated products adhered to the gastric mucosa, whereas CAP and methacrylate copolymer... 

The safe levels of hepatotoxins in food and drinking waters have been evaluated in terms of tolerable daily intake (TDl). This value should be ideally taken as a result of human studies, but often such studies are inadequate or nonexistent. Alternatively, they are often obtained after animal studies, although the variability in sensitivity between animals and humans that makes necessary the estabhshment of safety factors to deal with this uncertainty should be taken into account. 

There is considerable cross-reactivity with other NSAIDs and the now widely banned food colorant tar-trazine (78). Cross-sensitization between aspirin and tar-trazine is common for example, in one series 24% of aspirin-sensitive patients also reacted to tartrazine (SEDA-9, 76). 

Antimicrobial medication requires the nurse to follow the same general administration procedures that are required for any type of medication. The most critical step is to determine if the patient has allergies to drugs, food, environmental stimuM, and a family history of allergies to antibiotics. There is also a high incidence of cross sensitivity between some antibiotics such as penicillin and cephalasporins. Always display allergies in red and clearly write them on the patient s record. Even if the patient s record indicates that the patient doesn t have allergies, always ask the patient each time you administer the antimicrobial medication. 

Several aspects affect the extent and character of taste and smell. People differ considerably in sensitivity and appreciation of smell and taste, and there is lack of a common language to describe smell and taste experiences. A hereditary or genetic factor may cause a variation between individual reactions, eg, phenylthiourea causes a bitter taste sensation which may not be perceptible to certain people whose general abiUty to distinguish other tastes is not noticeably impaired (17). The variation of pH in saUva, which acts as a buffer and the charge carrier for the depolarization of the taste cell, may influence the perception of acidity differently in people (15,18). Enzymes in saUva can cause rapid chemical changes in basic food ingredients, such as proteins and carbohydrates, with variable effects on the individual. 

Whatever the physiology of odor perception may be, the sense of smell is keener than that of taste (22). If flavors are classed into odors and tastes as is common practice in science, it can be calculated that there are probably more than 10 possible sensations of odor and only a few, perhaps five, sensations of taste (13,21,35—37). Just as a hereditary or genetic factor may cause taste variations between individuals toward phenylthiourea, a similar factor may be in operation with odor. The odor of the steroid androsterone, found in many foods and human sweat, may eflcit different responses from different individuals. Some are very sensitive to it and find it unpleasant. To others, who are less sensitive to it, it has a musk or sandalwood-like smell. Approximately 50% of the adults tested cannot detect any odor even at extremely high concentrations. It is befleved that this abiUty is genetically determined (38). 

A study that examined the interaction between exposure concentration and time of exposure on nervous system function found that concentration, rather than time of exposure, was more important in determining effects (Bushnell 1997). Rats were trained to press two levers for food reward one lever when a light flashed, the second lever produced food when there was no signal. The trained rats were exposed to 0,400, 800, 1,200, 1,600,2,000, or 2,400 ppm trichloroethylene for 0.33, 0.67, or 1 hour. Response times were signiflcantly increased only at 2,400 ppm at 0.67 and 1 hour. Sensitivity was significantly decreased at 2,400 ppm at all exposure times. At 0.33 hour, sensitivity was not affected at the other concentrations. At 0.67 hour, sensitivity was significantly decreased at 2,000, and 1,200 ppm, and at 1 hour, sensitivity was... 

Applications Membranes create a boundary between different bulk gas or hquid mixtures. Different solutes and solvents flow through membranes at different rates. This enables the use of membranes in separation processes. Membrane processes can be operated at moderate temperatures for sensitive components (e.g., food, pharmaceuticals). Membrane processes also tend to have low relative capital and energy costs. Their modular format permits rehable scale-up and operation. This unit operation has seen widespread commercial adoption since the 1960s for component enrichment, depletion, or equilibration. Estimates of annual membrane module sales in 2005 are shown in Table 20-16. Applications of membranes for diagnostic and bench-scale use are not included. Natural biological systems widely employ membranes to isolate cells, organs, and nuclei. 

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