Four cases of wheat-dependent exercise-induced anaphylaxis with negative gluten cap-rast score]

BACKGROUND: Either omega-5 gliadin or high molecular weight glutenin is known to be a major allergen in wheat-dependent exercise-induced anaphylaxis (WDEIA). It is generally considered that gluten specific IgE score is more reliable than that of wheat specific IgE score for the diagnosis of WDEIA. Our aim was to verify the significance of gluten specific IgE in the diagnosis of WDEIA. METHODS: We evaluated the result of gluten CAP-RAST score and omega-5 gliadin specific IgE score on four WDEIA patients who visited our hospital during the years 2004 and 2005, whose diagnosis were onfirmed by prick tests, immunoblot tests and provocation tests. RESULTS: Contrary to our expectations, all four patients showed negative gluten CAP-RAST scores, however all patient's omega-5 gliadin specific IgE scores were positive. CONCLUSION: Our results suggest that gluten specific CAP-RAST score is unreliable in the diagnosis of WDEIA. On the other hand omega-5 gliadin specific IgE score is possibly a better candidate as a diagnostic tool for WDEIA.     

A Comparative Analysis of the Murine Thymic Microenvironment in Normal,Autoimmune, and Immunodeficiency States

It is widely accepted that the thymic microenvironment regulates normal thymopoiesis through a highly coordinated and complex series of cellular and cytokine interactions. A direct corollary of this is that abnormalities within the microenvironment could be of etiologic significance in T-cell-based diseases. Our laboratory has developed a large panel of monoclonal antibodies (mAbs) that react specifically with epithelial or nonepithelial markers in the thymus. We have taken advantage of these reagents to characterize the thymic microenvironment of several genetic strains of mice, including BALB/cJ, C57BL/6J, NZB/BlnJ, SM/J, NOD/Ltz, NOD/Ltz-scid/sz, C57BL/6J-Hcph m^e/Hcph m^e, and ALY/NscJcl-aly/aly mice, and littermate control animals. We report herein that control mice, including strains of several backgrounds, have a very consistent phenotypic profile with this panel of monoclonal antibodies, including reactivity with thymic epithelial cells in the cortex, the medulla and the corticomedullary junction, and the extracellular matrix. In contrast, the disease-prone strains studied have unique, abnormal staining of thymic cortex and medulla at both the structural and cellular levels. These phenotypic data suggest that abnormalities in interactions between developing thymocytes and stromal cells characterize disease-prone mice.     

Age-dependent change in activities of lysosomal enzymes in rat brain

The age-dependent change in activities of seven lysosomal enzymes (cathepsin D, β-glucuronidase, acid phosphatase, acid/alkaline DNases and acid/alkaline RNases) was studied in four brain regions (cerebrum, hippocampus, pons and cerebellum) of Wistar rats. The activity of cathepsin D was significantly increased with aging in the four regions. The age-dependent change in activities of acid and alkaline DNases showed the characteristic regional difference, and the ratio of acid to alkaline DNases was increased with aging in all regions. Acid RNase showed the lowest activity in 18-month-old rats, and alkaline RNase activity was decreased with aging. The activity of β-glucuronidase was higher in 2-month-old rats in all of the regions studied. Acid phophatase showed no significant age-dependent change except in pons. The study demonstrated that all of the lysosomal enzyme activities do not change in parallel with aging, and that the age-dependent change showed the characteristic regional difference.     

Structural basis for distinct roles of Lys63- and Lys48-linked polyubiquitin chains

Ubiquitination, a modification in which single or multiple ubiquitin molecules are attached to a protein, serves as a signalling function that controls a wide variety of cellular processes. To date, two major forms of polyubiquitin chain have been functionally characterized, in which the isopeptide bond linkages involve Lys48 or Lys63. Lys48-linked polyubiquitin tagging is mostly used to target proteins for degradation by the proteasome, whereas Lys63-linked polyubiquitination has been linked to numerous cellular events that do not rely on degradative signalling via the proteasome. Apparently linkage-specific conformations of polyubiquitin chains are important for these cellular functions, but the structural bases distinguishing Lys48- and Lys63-linked chains remain elusive. Here, we report NMR and small-angle X-ray scattering (SAXS) studies on the intersubunit interfaces and conformations of Lys63- and Lys48-linked di- and tetraubiquitin chains. Our results indicate that, in marked contrast to Lys48-linked chains, Lys63-linked chains are elongated molecules with no stable non-covalent intersubunit interfaces and thus adopt a radically different conformation from that of Lys48-linked chains.     

Stimulatory effect of vasoactive intestinal polypeptide on catecholamine secretion from isolated guinea pig adrenal chromaffin cells

The stimulatory effect of vasoactive intestinal polypeptide (VIP) on catecholamine (CA) secretion from isolated guinea pig adrenal chromaffin cell was studied. VIP (1-10 microM) induced dose-dependent CA secretion, which was slow and continued for at least 30 min. This VIP-induced CA secretion was dependent on the presence of Ca2+ in the medium, but no significant increase in Ca2+ uptake by the cells was observed during their stimulation with VIP. Studies on the intracellular free Ca2+ level ([Ca2+]i) using fura-2 showed that acetylcholine and muscarine induced a marked increase in the [Ca2+]i, but that VIP induced only a slight increase. Thus VIP may induce CA secretion by increasing the sensitivity of the secretion of CA to Ca2+.     

Tissue-engineered vascular autograft: inferior vena cava replacement in a dog model

Tissue-engineered vascular autografts (TEVAs) were made by seeding 4-6 x 10(6) of mixed cells obtained from femoral veins of mongrel dogs onto tube-shaped biodegradable polymer scaffolds composed of a polyglycolid acid (PGA) nonwoven fabric sheet and a copolymer of L-lactide and caprolactone (n = 4). After 7 days, the inferior vena cavas (IVCs) of the same dogs were replaced with TEVAs. After 3, 4, 5, and 6 months, angiographies were performed, and the dogs were sacrificed. The implanted TEVAs were examined both grossly and immunohistologically. The implanted TEVAs showed no evidence of stenosis or dilatation. No thrombus was found inside the TEVAs, even without any anticoagulation therapy. Remnants of the polymer scaffolds were not observed in all specimens, and the overall gross appearance similar to that of native IVCs. Immunohistological staining revealed the presence of factor VIII positive nucleated cells at the luminal surface of the TEVAs. In addition, lesions were observed where alpha-smooth muscle actin and desmin positive cells existed. Implanted TEVAs contained a sufficient amount of extracellular matrix, and showed neither occlusion nor aneurysmal formation. In addition, endothelial cells were found to line the luminal surface of each TEVA. These results strongly suggest that "ideal" venous grafts with antithrombogenicity can be produced.     

Culture of chondrocytes in fibroin-hydrogel sponge

Fibroin-hydrogel sponge and collagen gel were used as scaffold for in vitro cartilage regeneration. Fibroin-hydrogel sponge was formed by phase separation from freezed fibroin solution. Chondrocytes were harvested from proximal humerus, distal femur and proximal tibia of 4-week-old Japanese white rabbits and inoculated in the fibroin-hydrogel sponge and collagen gel. Those constructs were cultured in DMEM supplemented with 10% FCS and 50 ml L-ascorbate at 37 degrees C. Histological observation, measurement of sulfated glycosaminoglycan and cell density were carried out at 3, 7, and 14 days after the cultivation. Well-defined cartilage tissue can be seen both in the fibroin-hydrogel sponge and in the collagen gel. The matrix was intensely stained by safranin-O and showed a metachromatic reaction in both group. However, the quantity of sulfated glycosaminoglycan and cell density of the fibroin-hydrogel sponge group were increased more rapidly than these of the collagen gel group. Thus, the chondrocytes proliferated in the fibroin sponge without losing their differentiated phenotype. It is possible that culture environment in the fibroin sponge was suitable for chondrocytes regeneration.