Application of Several Special Staining Methods for Paraffin Sections on Epon-Embedded Semithin Sections

Aim: This study aimed to compare several specific staining protocols recommended for paraffin sections and toluidine blue and light green double staining combination to be tried for the first time with routine toluidine blue staining on semithin epon sections. Material and Methods: Samples of 1x1x1 mm were taken from the liver, skin, and aorta tissues of Wistar albino adult rats. Tissue samples were fixed with 5% glutaraldehyde at +4º C overnight, postfixed with 1% osmium tetroxide for one hour, and then, blocked with Epon 812 after processing. Semithin sections of 1 μm thickness were obtained from the epon blocks. Sections were stained with Altmann’s method (for mitochondria), Verhoeff’s method (for elastic fibers), Gordon&Sweets’ silver impregnation method (for type III collagen), toluidine blue and light green double staining combination (for type I collagen) and routine toluidine blue method. Results: In liver sections, mitochondria in hepatocytes were differentiated by the Altmann method, and stromal type III collagen fibers were distinguished with Gordon&Sweets’ method. Elastic lamellar structures were easily observed in black in the aortic sections stained with the Verhoeff method. Successful results were obtained in the staining of dermal type I collagen with toluidine blue and light green double staining in skin sections. Conclusion: Since the specific staining tried for the first time gave positive results in epon sections, it was concluded that these methods can be used to determine the localization of cellular and intercellular components that are aimed to be examined at the ultrastructural level

Risk Factors Influencing Tolerance and Clinical Features of Food Protein-induced Allergic Proctocolitis

Objective: Continued progress in our understanding of the food protein-induced allergic proctocolitis (FPIAP) will provide the development of diagnostic tests and treatments. We aimed to identify precisely the clinical features and natural course of the disease in a large group of patients. Also, we investigated the predicting risk factors for persistent course since influencing parameters has not yet been established. Methods: Infants who were admitted with rectal bleeding and had a diagnosis of food protein-induced allergic proctocolitis in 5 different allergy or gastroenterology outpatient clinics were enrolled. Clinical features, laboratory tests, and prognosis were evaluated. Risk factors for persistent course were determined by logistic regression analyses. Results: Among the 257 infants, 50.2% (n = 129) were girls and cow's milk (99.2%) was the most common trigger. Twenty-four percent of the patients had multiple food allergies and had more common antibiotic use (41.9% vs 11.8%), atopic dermatitis (21% vs 10.2%), wheezing (11.3% vs 1.5%), colic (33.8% vs 11.2%), and IgE sensitization (50% vs 13.5%) compared to the single-food allergic group (P < 0.001,P = 0.025,P = 0.003,P < 0.001, respectively). In multivariate logistic regression analysis, presence of colic (odds ratio [OR]: 5.128, 95% confidence interval [CI]: 1.926-13.655,P = 0.001), IgE sensitization (OR: 3.964, 95% CI: 1.424-11.034,P = 0.008), and having allergy to multiple foods (OR: 3.679, 95% CI: 1.278-10.593,P = 0.001] were found to be risk factors for continuing disease after 1 year of age. Conclusion: Although most children achieve tolerance at 1 year of age, IgE sensitization, allergy to multiple foods, and presence of colic were risk factors for persistent course and late tolerance. In this context, these children may require more close and extended follow-up