Sensitivity to Sulfited Foods among Sulfite-Sensitive Subjects with Asthma

Eight individuals with asthma who had been diagnosed as sulfite sensitive on the basis of double-blind capsule-beverage challenges were subjected to challenges with various sulfited foods, including lettuce, shrimp, dried apricots, white grape juice, dehydrated potatoes (as mashed potatoes), and mushrooms. Four of these patients failed to respond to challenges with any of the sulfited foods. The other four patients experienced a decrease in pulmonary function on double-blind challenges with sulfited lettuce. Two of three of these patients reacted to challenges with dried apricots and white grape juice; the fourth patient has not yet been challenged with these products. Only one of these four patients reacted to challenges with dehydrated potatoes and mushrooms, and, in this case, the response to double-blind challenges with dehydrated potatoes was not consistent. None of the sulfite-sensitive subjects with asthma responded to challenges with sulfited shrimp. It is concluded that sulfite-sensitive subjects with asthma will not necessarily react after ingestion of sulfited foods. The likelihood of a reaction is dependent on the nature of the food, the level of residual sulfite, the sensitivity of the patient, and perhaps on the form of residual sulfite and the mechanism of the sulfite-induced reaction

Spatial differences in corneal electroretinogram potentials measured in rat with a contact lens electrode array

PURPOSE: It has been known for several decades that the magnitude of the corneal electroretinogram (ERG) varies with position on the eye surface, especially in the presence of focal or asymmetric stimuli or retinal lesions. However, this phenomenon has not been well-characterized using simultaneous measurements at multiple locations on the cornea. This work provides the first characterization of spatial differences in the ERG across the rat cornea. METHODS: A contact lens electrode array was employed to record ERG potentials at 25 corneal locations simultaneously following brief full-field flash stimuli in normally sighted Long-Evans rats. These multi-electrode electroretinogram (meERG) responses were analyzed for spatial differences in a-wave and b-wave amplitudes and implicit times. RESULTS: Spatially distinct ERG potentials could be recorded reliably. Comparing relative amplitudes across the corneal locations suggested a slight non-uniform distribution when using full-field, near-saturating stimuli. Amplitudes of a- and b-waves were approximately 3 % lower in the inferior quadrant than in the superior quadrant of the cornea. CONCLUSIONS: The present results comprise the start of the first normative meERG database for rat eyes and provide a basis for comparison of results from eyes with functional deficit. Robust measures of spatial differences in corneal potentials will also support optimization and validation of computational source models of the ERG. To fully utilize the information contained in the meERG data, a detailed understanding of the roles of the many determinants of local corneal potentials will eventually be required