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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: The purpose of this study was to examine longitudinal changes of the occlusal force distribution in lower distal-extension removable partial dentures with the conus crown telescopic system. Occlusal force applied to the denture and forces transmitted to the retainers were measured on several separate occasions from the insertion of new dentures to about 3 months after. The occlusal force distribution ratio to the retainers was calculated when a load of 20N was applied to the denture.The results are summarized as follows:〈list xml:id="l1" style="custom"〉(i) The more posterior the loading point of occlusal force, the smaller was the ratio. When the occlusal force was applied to the most anterior artificial tooth, the ratio was 65-100% of the occlusal force.(ii) As the denture wearing time proceeded, the ratio was decreased. The smaller the ratio, the greater was the rate of its decrease.

Notes: Not only forces but also torque exerted on abutment teeth are important factors for planning the construction of distal extension removable partial dentures. The purpose of this study was to make longitudinal analysis of torque transmitted from denture base to a direct abutment tooth of these dentures with circumferential clasps.The results are summarized as follows:(i) Vertical Max. MT (maximal mean value of torque) was decreased and became constant after one or one and half months of the insertion of new dentures.(ii) Lateral Max. MT in one subject was changed from the lingual direction to the buccal direction while in another subject it was constant.(iii) In the vertical direction, there were no remarkable differences of Max. MT and Ave. T (average value of torque) between subjects. Max. MT was 5–10 × 10−3 kgm−1 in the downward. Ave. T was 2–3 × 10−3kgm ss−1 in the downward and 0.3 × 10−3kgm ss−1 in the upward.(iv) In the lateral direction, there were considerable differences of Max. MT and Ave. T between subjects. Max. MT was less than 20 × 10−3kgm. Ave. MT was 2–8 × 10−3 kgm ss−1.

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: Using the ELISA method, IgE antibodies to chironomid midges; Tokunagayusurika akamusi larva (TAL), T. akamusi adult (TAA), Chironomus yoshimatsui larva (CYL), C. yoshimatsui adult (CYA) and Chironomus plumosus adult (CPA), were measured in the sera of 36 children with bronchial asthma who visited Tamano City Hospital near Lake Kojiima in the Okayama prefecture. IgE antibodies to adult midges (TAA, CYA and CPA) were widely detected, but only few IgE antibodies to larvae (TAL and CYL). The amount of IgE antibody to CYA and to CPA correlated (P 〈 0.001), but the amount of IgE antibody to TAA and to CYA or CPA did not. This suggests that the allergenicity of CYA and CPA is similar, but the allergenicity of TAA is independent of that of CYA or CPA. On the other hand, the ELISA inhibition test showed that TAA allergenicity was independent of that of TAL, CYL, CYA, CPA and the house-dust mite, Dermatophagoides farinae (Df), The inhibition test also showed that CYA and CPA had similar allergenicity, but differed from TAL, TAA, CYL and Df. This indicates that the allergenicities of chironomid midges change during the metamorphosis from larva to adult, and are not common among all species.

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.

Notes: summary The effect of balancing-side occlusal contact patterns on ipsilateral TMJ dynamics was evaluated in this study. Vertical displacement of the balancing-side lower second molar during clenching at canine edge-to-edge position, with 0 and 1 mm of inter-canine distance, was measured for 42 normal subjects in relation to their balancing-side occlusal contact. Balancing-side occlusal contact was classified into four following patterns; (1) simultaneous balancing-side and working-side contact (without clenching); (2) balancing-side contact (with clenching only); (3) no balancing-side contact (with or without clenching); and (4) exclusive balancing-side contact (no working-side contact). The vertical displacement of the balancing-side condyle, calculated from the displacement of the balancing-side second molar, showed three different types of displacement pattern. These three types showed distinctive incidence in relation to the pattern of balancing-side occlusal contact. It was revealed that balancing-side occlusal contact can affect the ipsilateral TMJ dynamics.

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.