1,721,031 research outputs found
Reproducility of APT
No full textBackground: The aim of the present study was to evaluate the reproducibility of Atopy Patch Tests (APT) by simultaneously applying 2 identical patch test series in 85 patients affected by atopic dermatitis. Methods: The test substances included 2 commercially available materials (Dermatophagoides mix 20% pet., Alternaria Alternata 2.4% pet.) and 8 self-made food preparations containing egg yolk, egg white, peanuts, cow’s milk, soy milk, wheat flour, rice, and corn meal. Results: The percentage of agreement in the frequency of positive responses varied from 87.1% (corn meal) to 100% (soy milk). The reproducibility was satisfactory for Dermatophagoides mix, Alternaria alternata, egg yolk, and soy milk. Conclusions: For Dermatophagoides and Alternaria Alternata the agreement rate was similar to that of standard patch tests and therefore APTs may be considered sufficiently reproducible to be employed as a diagnostic testing procedure. As regards food materials, such as soy milk, egg yolk, and corn meal, APT reproducibility may be acceptable. For other foodstuffs, preparation methods have to be improved
Thickness and echogenicity of the skin in children as assessed by 20-MHz ultrasound
No full textBackground: Skin anatomy and physiology undergo modifications throughout the whole lifespan. in children the skin appears with structural characteristics, as evaluated by histology, which differ from those of adults, especially in the first years of life. Objective: The aim of our study was to evaluate skin thickness and echogenicity at different sites in children by 20-MHz ultrasound. Methods: Eight skin sites of 42 children and 30 young adults were studied with a 20-MHz B scanner. Skin thickness and mean echogenicity were evaluated. The echographic images were processed and segmented by a dedicated program: the 0-30 amplitude interval, which marks the hypoechogenic parts of the tissue, and the 201-255 range, highlighting the hyperreflecting areas, have been selected. Results and Conclusion: Whereas skin thickness shows a gradual increase from birth to adulthood, maturation of the skin leads to variations in the intensity of its echogenicity, depending on the different skin areas. Whereas on the face and the trunk it appears lower in adults with respect to children, a gradual increase can be observed on the limbs with growing age. The distribution of skin reflectivity also greatly varies in different phases of life. Copyright (C) 2000 S. Karger AG, Basel
Combined skin prick and patch testing enhances identification of peanut-allergic patients with atopic dermatitis
No full textBackground: Food atopy patch tests (APTs) are considered a useful tool for the diagnosis of food allergy. Hypersensitivity to peanuts has not been investigated by means of APTs so far. Methods: APTs and skin prick tests (SPTs) with peanuts were performed in 136 atopic dermatitis (AD) patients. Relevance of positive and negative responses to these tests was assessed by repeated open challenges with peanuts. Results: Nine percent of our AD patients reacted to the challenge. Positive responses to APTs were recorded in 19\% of the patients, whereas in 12\% positive SPTs were observed. APTs were more frequently positive in subjects with eczematous responses after challenge with respect to those with urticarial reactions. SPT reactivity proved to be higher in patients above 12 years of age, whereas APT positivity was more frequent in children under 6 years. APT sensitivity proved significantly higher than SPT sensitivity, in particular in children under 12 years of age. On the contrary, SPT specificity and positive predictive value were significantly higher with respect to those of APT in the age group of subjects under 6 years of age. Conclusions: Our data suggest that APTs with peanuts may represent a useful integration to standard testing modalities employed for the diagnosis of peanut allergy in AD patients
Does Static precede dynamic osteogenesis in endochondral ossification as occurs in intramembranous ossification?
No full textEndochondral ossification takes place with calcified cartilage cores providing a rigid scaffold for new bone formation. Intramembranous ossification begins in connective tissue and new bone formed by a process of static ossification (SO) followed by dynamic ossification (DO) as previously described. The aim of the present study was to determine if the process of endochondral ossification is similar to that of intramembranous ossification with both a static and a dynamic phase of osteogenesis. Endochondral ossification centers of the tibiae and humeri of newborn and young growing rabbits were studied by light and transmission electron microscopy. The observations clearly showed that in endochondral ossification, the calcified trabeculae appeared to be lined first by osteoclasts. The osteoclasts were then replaced by flattened cells (likely cells of the reversal phase) and finally by irregularly arranged osteoblastic laminae, typical of DO. This cellular sequence did not include osteoblasts seen in the phase of SO. These findings clearly support our working hypothesis that SO only forms in soft tissues to provide a rigid framework for DO, and that DO requires a rigid mineralized surface. The presence of osteocytes in contact with the calcified cartilage also suggests the existence of stationary osteoblasts in endochondral ossification. Stationary osteoblasts did not appear to be a unique feature of SO. The presence of stationary osteoblasts may appear to provide the initial osteocytes during osteogenesis that may function as mechanosensors throughout the bone tissue. If this is the case, then bone would be capable of sensing mechanical strains from its inception
Heterotopic human bone: mechanism of deposition and structure.
No full textHeterotopic human bone is a pathologic bone that needs to degenerate rather than to be preserved, and for this reason rapidly osteocyte death occurs
Bone tissue electroporation: a preliminary in vivo study.
No full textGoal of the study is to extablish the values of parameners of electroporation above which, in the treated bone regions, cell damage becomes irreversible, leading to cell death
Contact sensitization to disperse dyes in children
No full textFrom January 1996 to December 2000, 1098 children, including 667 subjects with suspected allergic contact dermatitis and 431 patients with atopic dermatitis ( AD), were patch tested with seven disperse dyes: disperse blue 124 (DB124), disperse blue 106 (DB106), disperse red 1 (DR1), disperse yellow 3 (DY3), disperse orange 3 (DO3), p-aminoazobenzene (PAAB), and p-dimethylaminoazobenzene (PDAAB). Of these, 51 patients (4.6\%; 34 girls and 17 boys) proved sensitized to disperse dyes. AD or history of AD was present in 30 patients (59\%). The most common sensitizer was DY3 ( 17 patients), followed by DO3 ( 15 patients), and DB124 ( 14 patients). Among dye-positive patients, about 12\% were sensitized to disperse dyes alone and only 14\% reacted to para-phenylenediamine. In disperse dye-sensitive children not affected by AD, the feet, axillae, and groin appeared to be the most common localizations, whereas in those with AD, involvement of the face and the flexural areas of the limbs was more common. In conclusion, our study showed that in children with suspected contact sensitization, disperse dyes should be regarded as potential triggering allergens
Endochordral versus intramembranous ossification: analogies and differences.
No full textStationary osteoblasts are not a typical finding of static osteogenesis; they may also exist in the earòly stage of dynamic osteogenesis
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