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Notes: Optical absorption spectrum of polydiacetylene (PDA) crystalline films shifts toward higher energies as irregularity in molecular ordering is increased. We view this behavior in terms of the reduced overlap of conjugated π-electron wave function among one-dimensional PDA molecular wires. This point is further discussed by using the Kronig–Penney model, in which the influence of irregularity in molecular ordering is assessed in terms of a change in the intermolecular distance which in turn shifts the fundamental absorption edge. © 2001 American Institute of Physics.

Notes: Two distinct allergens of Dermatophagoides pteronyssinus were isolated from culture medium extract and whole body extract monitored by the same probe of pooled human serum and compared. IgE-binding activity of allergens from the two sources was detected by microplate-ELISA with the same probe throughout the column chromatography. An allergen obtained from culture medium extract (Ag-CME) had a molecular weight of 27,000 by SDS-polyacrylamide gel electrophoresis (PAGE) and two isoelectric point ranges, pI 4.0–4.7 and 5.9–6.8. Another allergen from whole body extract (Ag-WBE) had a molecular weight of 15,000 by SDS-PAGE and an isoelectric point range, pI 4.8–5.3. Ag-CME and Ag-WBE are probably the same allergens as antigen P1 and DpX, respectively.

Notes: Background Both prostaglandin (PG) D receptor (DP) and CRTH2 (chemoattractant receptor-homologous molecule expressed on Th2 cells)/DP2 are high-affinity receptors for PGD2. Previous studies have demonstrated that PGD2 enhances releasability and induces CRTH2/DP2-mediated migration in human basophils, but the precise effects of PGD2 on basophils as well as receptor usage have not been fully clarified.Objective We comprehensively explored the roles of DP and CRTH2/DP2 in basophil functions by using selective agonists and antagonists for each receptor.Methods DP and CRTH2/DP2 transcripts were quantified by real-time PCR. We studied the effects of selective agonists (DP: BW245C; CRTH2/DP2: 13,14-dihydro-15-keto (DK)-PGD2) and/or antagonists (DP: BWA868C; CRTH2/DP2: ramatroban) on Ca2+ mobilization, migration, degranulation, CD11b expression and survival of human basophils.Results Basophils expressed transcripts of both DP and CRTH2/DP2, but the levels of CRTH2/DP2 transcripts were ca. 100-fold higher compared with DP transcripts. Ca2+ influx was induced in basophils by either PGD2 or DK-PGD2/CRTH2 agonist but not by BW245C/DP agonist. Basophils treated with PGD2 were completely desensitized to subsequent stimulation with DK-PGD2, but not vice versa. DK-PGD2 as well as PGD2 up-regulated CD11b expression, induced migration and enhanced degranulation, and those effects were completely antagonized by ramatroban/CRTH2 antagonist. In contrast, BW245C/DP agonist exhibited an inhibitory effect on basophil migration and IgE-mediated degranulation, and the migration inhibitory effect was effectively antagonized by BWA868C/DP antagonist. On the other hand, while PGD2 significantly shortened the basophil life-span, neither DK-PGD2/CRTH2 agonist nor BW245C/DP agonist did.Conclusion CRTH2/DP2 is primarily responsible for the pro-inflammatory effects of PGD2 on human basophils, while DP introduces negative signals capable of antagonizing the effects of CRTH2/DP2 in these cells. The effects of PGD2 on longevity imply a mechanism(s) other than via DP or CRTH2/DP2. CRTH2/DP2 on basophils may afford opportunities for therapeutic targeting in allergic inflammation.

Notes: Endothelin is a potent bronchoconstrictor peptide first identified as a novel vasoconstrictor produced by vascular endothelial cells. Recent reports suggest that airway epithelial cells are also capable of releasing this active peptide. To investigate the regulatory mechanism of endothelin expression, we studied the effects of endotoxin and pro-inflammatory cytokines such as interleukin-1 and tumour necrosis factor on the expression and release of endothelin-1 by airway epithelial cells. Both endotoxin and the cytokines stimulated endothelin-1 release by human bronchial epithelial cells. Northern blot analysis showed increased expression of preproendothelin-1 mRNA by these factors. These results suggested that airway epithelial cells might play a role in the local airway smooth muscle tone through the production of endothelin, which might be upregulaled by inflammatory products in the airways.

Notes: Mite fauna and fungal flora in the house dust from homes of asthmatic children with positive and negative skin test to house dust allergen and non-asthmatic controls were examined. There was no conspicuous difference in mile species distribution among the three groups. Pyroglyphid mites dominate the mite fauna in house dust more than half of which being Dermatophagoides: D. pteronvssinus and D. farinae. There was no statisucally significant difference in numbers between the two species and either species could dominate depending on the conditions of the individual houses. The average number of acarina in 0.5 g of fine dust did not differ statistically among the three groups; however, mite number per square meter floor differed between patients with positive skin test and negative skin test. The results suggest that house-cleaning might influence the possible sensitization of children. The genetic distribution of mould fungi in house dust was largely similar to that of airborne fungi. The average number of fungal colonies detected in 0.5 g of dust did not differ statistically among the three groups. Wallemia with its minute spores may cause sensitization but has so far been investigated investigated.

Notes: Background: We cultured Dermatophagoides farinae (Df), one of the most common mites in house dust and the most important allergen among natural allergens. With this material, we attempted to produce an animal model of the atopic eczema/dermatitis syndrome (AEDS).Methods: We cultured Df mites in high density and prepared a crude extract of Df (DfE) together with the culture medium. We applied the extract to the back skin of NC/Nga and BALB/c mice three times per week for 8 weeks.Results: In the NC/Nga group, dryness or scaling appeared on the skin, and scratching behavior increased at the second week in the DfE-treated group. Skin erosion and hemorrhage occurred at the fourth week. The epidermis thickened and deepened into the upper dermis, in which mast cells were highly accumulated, corresponding with the skin lesion of AEDS patients. Specific IgE and IgG to DfE and total IgE were elevated in the sera. Mice treated with an extract of mite culture medium did not develop skin lesions. In the BALB/c group, mice developed specific IgE and IgG to DfE, however, no typical skin lesions appeared. Mast cells in the upper dermis did not increase.Conclusions: Repeated painting of Dermatophagoides extract produced IgE-associated AEDS-like lesions on the skin of NC mice.

Notes: To determine the amount of chironomids and mite antigens in the indoor and outdoor environment, we investigated samples from air, soil and house dust in the area around Lake Kojima, located in the western part of Japan. Three species of chironomid (Tokunagayusurika akamusi, Chironomus yoshimatsui and Chironomus plumosus) and a species of mite, Dermatophagoides farinae antigens were studied. The antigens were detected and quantified by inhibition ELISA. In the outdoor environment, C. yoshimatsui and T. akamusi antigens were more abundant than mite antigen, and seasonal fluctuations were observed. In the indoor environment, mite was the predominant antigen. D. farinae antigen was detected in almost all dust samples, with a slight reduction in winter compared to summer.

Notes: Background: Cytokines liberated by TH2 cells play crucial roles in the pathogenesis of bronchial asthma. Recent studies have demonstrated that CC chemokine receptor (CCR)4 is preferentially expressed by TH2 cells. These facts suggest possible involvement of two CCR4-specific ligands i.e., thymus and activation-regulated chemokine (TARC) and macrophage-derived chemokine (MDC), in the pathogenesis of bronchial asthma via recruitment of TH2 cells to inflammatory sites. We investigated the levels of TARC and MDC in the serum and induced sputum of asthmatics. Methods: The levels of TARC in the serum (46 asthmatics and 26 healthy subjects) and induced sputum (30 asthmatics and 6 healthy subjects) were measured using a highly sensitive ELISA system. The levels of eotaxin and MDC were also measured by ELISA. Results: TARC, but not MDC, was significantly increased in asthmatic sera (P〈0.001). Although MDC was undetectable in the sputum of most cases by our assay system, sputum TARC was significantly increased (P=0.027). Conclusions: The elevated TARC levels in asthmatics might be involved in the pathophysiology of asthma.