ABSTRACT
A double-masked, randomised, placebo-controlled study was conducted to evaluate the effectiveness of nedocromil 2% eyedrops, a mast cell stabilizer, in 20 symptomatic patients with vernal conjunctivitis. A 1-week baseline period was followed by 6 weeks of treatment. Clinical examination and cytological evaluation of tear fluid were performed weekly, and the patients recorded their subjective assessment on a daily diary card. The nedocromil group showed significantly less hyperaemia in the course of treatment than did the placebo group, and significantly less itching at all visits compared with baseline itching. In the nedocromil-treated group, but not in the placebo group, the number of neutrophils, eosinophils and lymphocytes in tears decreased significantly during some treatment weeks when compared with baseline. The overall assessment of treatment efficacy by both clinician and patient was significantly in favour of nedocromil treatment over placebo.
Subject(s)
Anti-Inflammatory Agents, Non-Steroidal/therapeutic use , Conjunctivitis, Allergic/drug therapy , Quinolones/therapeutic use , Tears/cytology , Adolescent , Adult , Child , Conjunctivitis, Allergic/pathology , Double-Blind Method , Female , Humans , Hyperemia/drug therapy , Male , Nedocromil , Ophthalmic Solutions , Pruritus/drug therapyABSTRACT
Eleven ryegrass-sensitive patients were challenged weekly for 4 weeks with incremental doses of ryegrass allergen applied topically to one eye; a buffer was applied to the other eye. A clinical examination and tear-fluid cytology were performed before challenge and at 20 minutes, 1 hour, and 6 hours after challenge. A significant clinical reaction and neutrophil accumulation in the tear film occurred at 20 minutes. At 1 hour, a clinical response and tear cytologic reaction were present only at higher antigen concentrations. Six hours after antigen challenge, only the highest allergen concentration (320,000 BU/ml) produced a clinical late-phase reaction (LPR) (p less than 0.01) and tear cytologic change (presence of eosinophils and lymphocytes). Five nonryegrass-sensitive control subjects were unresponsive to a similar challenge. These results indicate that a conjunctival response to allergen challenge is dose dependent, that is, the higher the dose, the more likely an LPR will occur and that an LPR correlates with significant numbers of inflammatory cells in the tear film.
Subject(s)
Allergens/administration & dosage , Eye Diseases/physiopathology , Hypersensitivity, Delayed/diagnosis , Hypersensitivity/physiopathology , Immunologic Tests , Adolescent , Adult , Conjunctiva/physiopathology , Dose-Response Relationship, Drug , Female , Humans , Hypersensitivity, Immediate/diagnosis , Male , Middle Aged , Poaceae/immunology , Tears/cytology , Time FactorsABSTRACT
The clinical response after allergen challenge and immunologic mechanisms leading to tissue inflammation have been extensively studied in the skin, nose and lung of allergic subjects. The present paper reviews personal studies aimed at evaluating clinical, cellular and humoral events after administration of specific allergen to the eye. Specific conjunctival provocation tests performed in grass-sensitive patients caused persisting inflammatory changes in conjunctival scrapings and tear fluid with a significant accumulation of different inflammatory cells depending on the time of observation (neutrophils, 20 min; eosinophils, 6 h; neutrophils, eosinophils and lymphocytes, 12-24 h after provocation). Increasing the dose of allergen resulted in a dose-dependent increase in the number of inflammatory cells recruited. When high doses of allergen were used, the challenge not only induced late-phase histological changes, but also clinical symptoms 6-10 h after provocation. Several mediators of allergic inflammation, such as histamine, C3a des-Arg, leukotrienes B4 and C4, were also present and could be measured in tears after allergen challenge. Our studies represent the first evidence in humans that a late phase of allergic reaction occurs in the eye. They also suggest that the conjunctival provocation test may represent a model for the study of cells and mediators involved in the pathophysiology of allergic inflammation as well as of its pharmacologic modulation.
Subject(s)
Conjunctivitis, Allergic/immunology , Immunologic Tests/methods , Allergens , Conjunctivitis, Allergic/diagnosis , Conjunctivitis, Allergic/pathology , Dose-Response Relationship, Immunologic , Humans , Inflammation/diagnosis , Inflammation/immunology , Time FactorsABSTRACT
A study was conducted on pigs to evaluate the importance of gastric emptying rate in reflux esophagitis development. Gastric emptying was previously measured in 25 pigs. Then, the following operative procedures were carried out: Heller's cardiomyotomy, common bile duct ligature, cholecysto-gastric anastomosis, and extramucosal duodenal myotomy on 10 animals (group A); the same procedures except extramucosal duodenal myotomy on another 10 animals (group B); common bile duct ligature and cholecysto-gastric anastomosis on the last 5 animals (group C). Six months later, gastric emptying was measured again; whereas in group A a significant shortening of gastric emptying was found, the other 2 groups remained unchanged. Then, all the animals were sacrificed and the lower third of the esophagus was removed for histologic examination. In all the pigs undergoing cardiomyotomy (groups A and B) appearance of esophagitis was found. No signs of esophagitis were found in group C. The conclusions reached are cardiomyotomy is in all cases responsible for reflux esophagitis development; extramucosal duodenal myotomy is capable of shortening gastric emptying, but this does not affect reflux esophagitis development.
