Fluorescent ‘intravital’ imaging is a new research technique by which the interior of living tissues and organs (in living bodies, if possible) can be observed, revealing the kinetics of cell and molecular processes in real time. Recent technological innovations in optical equipment and fluorescence imaging techniques have enabled a variety of cellular phenomena in different tissues and organs to be characterized under completely native conditions. This shift from static to dynamic biology constitutes the beginning of a new era in biomedical sciences.

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In vivo imaging is a novel experimental approach for biological research.Multiphoton microscopy (MPM), a type of fluorescence microscopy, is a new tool for in vivo imaging analysis. MPM allows observation of both tissue structures and cell behaviors or cell-cell interactions in living animals in real time. Skin is an ideal tissue for MPM analysis as it is directly accessible to the microscope. In the skin, immune cells cooperate to maintain skin homeostasis or to exert immune responses against foreign antigens. In vivo imaging by MPM analysis provides precise information on cell dynamics in the skin, and has significantly expanded our knowledge of the cutaneous immune system. In this review, we will discuss recent insights related to the mechanisms of allergic skin inflammation that have been revealed by MPM analysis.

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Intravital imaging is becoming more popular and is being used to visualize cellular motility and functions. In contrast to in vitro analysis, which resembles in vivo analysis, intravital imaging can be used to observe and analyze cells directly in vivo. In this review, I will summarize recent imaging studies of autoreactive T cell infiltration into the central nervous system (CNS) and provide technical background. During their in vivo journey, autoreactive T cells interact with many different cells. At first, autoreactive T cells interact with endothelial cells in the airways of the lung or with splenocytes, where they acquire a migratory phenotype to infiltrate into the CNS. After arriving at the CNS, they interact with endothelial cells of the leptomeningeal vessels or the choroid plexus before passing through the bloodebrain barrier. CNS-infiltrating T cells become activated by recognizing endogenous autoantigens presented by local antigen-presenting cells (APCs). This activation was visualized in vivo by using protein-based sensors. One such sensor detects changes in intracellular calcium concentration as an early marker of T cell activation. Another sensor detects translocation of Nuclear factor of activated Tcells (NFAT) from cytosol to nucleus as a definitive sign of T cell activation. Importantly, intravital imaging is not just used to visualize cellular behavior. Together with precise analysis, intravital imaging deepens our knowledge of cellular functions in living organs and also provides a platform for developing therapeutic treatments.

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Discoveries from basic science research in the last decade have brought significant progress in knowledge of pathophysiologic processes of allergic diseases, with a compelling impact on understanding of the natural history, risk prediction, treatment selection or mechanism-specific prevention strategies. The view of the pathophysiology of allergic diseases developed from a mechanistic approach, with a focus on symptoms and organ function, to the recognition of a complex network of immunological pathways. Several subtypes of inflammation and complex immune-regulatory networks and the reasons for their failure are now described, that open the way for the development of new diagnostic tools and innovative targeted-treatments. An endotype is a subtype of a disease condition, which is defined by a distinct pathophysiological mechanism, whereas a disease phenotype defines any observable characteristic of a disease without any implication of a mechanism. Another key word linked to disease endotyping is biomarker that is measured and evaluated to examine any biological or pathogenic processes, including response to a therapeutic intervention. These three keywords will be discussed more and more in the future with the upcoming efforts to revolutionize patient care in the direction of precision medicine and precision health. The understanding of disease endotypes based on pathophysiological principles and their validation across clinically meaningful outcomes in asthma, allergic rhinitis, chronic rhinosinusitis, atopic dermatitis and food allergy will be crucial for the success of precision medicine as a new approach to patient management.

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Background: Although right middle lobe (RML)-atelectasis of the lungs is a common complication of asthma, the relevant data is limited. The aim of this study is to define the characteristics of RML atelectasis in asthma during childhood. Methods: Children with asthma who had recently developed RML atelectasis were included; antiinflammatory medications, clarithromycin, and inhaled salbutamol were prescribed, chestphysiotherapy (starting on the sixth day) was applied. Patients were reevaluated on the sixth, fourteenth, thirtieth, and ninetieth days, chest X-rays were taken if the atelectasis had not resolved at the time of the previous visit. Results: Twenty-seven patients (6.8 (4.8-8.3) years, 48.1% male) with RML atelectasis were included. Symptoms started 15 (7-30) days before admission. The thickness of the atelectasis was 11.8±5.8 mm; FEV₁% was 75.9±14.2 and Childhood Asthma Control Test scores were 11.8±5.6 at the time of admission. The atelectasis had been resolved by the sixth (n=3), fourteenth (n=9), thirtieth (n=10), and ninetieth days (n=3). The treatment response of the patients whose atelectasis resolved in fourteen days was better on the sixth-day (atelectasis thickness: 4.7±1.7 vs. 11.9±7.3 mm, p=0.021) compared to those whose atelectasis resolved later. Nearly half (54.5%) of the patients whose atelectasis had resolved by fourteen days were using controller medications at the time of admission. However, only two patients (13.3%) were on controller treatment in the latter group (p=0.032). Regression analysis didn't reveal any prognostic factors for the early resolution of atelectasis. Conclusions: Early diagnosis and treatment of RML atelectasis prevents complications. Patients who had early resolution of atelectasis had already been on anti-inflammatory medications, and responded better to aggressive treatment within the first week.

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Background: Minimal persistent inflammation (MPI) contributes to hyperreactivity in allergic rhinitis. However, little is known regarding whether pre-onset activation of eosinophils and mast cells is present or not in Japanese cedar pollinosis (JCP). Furthermore, a prophylactic effect of intranasal corticosteroids on such MPI in JCP has not been investigated. Methods: We designed a double-blinded, randomized, placebo-controlled, crossover trial. Twenty patients with JCP were examined outside the pollen season (UMIN000008410). Nasal provocation with paper discs containing extracts of Japanese cedar pollen was performed once a day for 3 consecutive days. Onset of nasal symptoms was monitored over 15 min after each provocation. The levels of eosinophil cationic protein (ECP) and tryptase in nasal secretions were examined. Fluticasone furoate nasal spray or placebo treatment was started one day before the first provocation. Results: In the placebo group, 25% of the patients showed onset of nasal symptoms following provocation on the first day. In addition, 75% and 68% of the patients showed symptom onset on the second and third day of provocation, respectively. After the first provocation, the levels of ECP and tryptase in nasal secretions were significantly increased. These increases were seen not only in symptomatic but also in asymptomatic subjects in response to provocation, and the levels were similar between these subjects. Prophylactic treatment with fluticasone significantly suppressed the increase in nasal ECP and tryptase associated with repeated provocations. Conclusions: These results suggest that pre-onset activation of eosinophils and mast cells is present in experimental JCP, and that prophylactic treatment with intranasal corticosteroids has the potential to control such activation.

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Backgrounds: It remains unclear whether a persistently high exhaled nitric oxide fraction (FeNO) in patients with controlled asthma is associated with the progressive loss of lung function. Methods: This was a 3-year prospective study. We examined the changes in pre- and post-bronchodilator forced expiratory volume in 1 s (FEV1) and FeNO in 140 patients with controlled asthma. We initially determined the FeNO cut-off point for identifying patients with a rapid decline in FEV1 (>40 mL/yr). Next, a total of 122 patients who maintained high or non-high FeNO were selected, and the associations between the FeNO trend and changes in FEV1 and bronchodilator response (BDR) were investigated. Results: A FeNO level >40.3 ppb yielded 43% sensitivity and 86% specificity for identifying patients with a rapid decline in FEV1. Patients with persistently high FeNO had higher rates of decline in FEV1 (42.7 ± 37.5 mL/yr) than patients with non-high FeNO (16.7 ± 31.5 mL/yr) (p < 0.0005). The changes in BDR from baseline to the end of the study, in patients who had high or non-high levels of FeNO were 0.8% and 0.1%, respectively ((p < 0.01). In a multivariate analysis adjusted by age, body mass index, asthma control, blood eosinophil numbers, and FEV1% of predicted, a FeNO level of ≥40 ppb was independently associated with an accelerated decline in FEV1 ((p < 0.05). Conclusions: This study suggests that FeNO is potentially valuable tool for identifying individuals who are at risk of a progressive loss of lung function among patients with controlled asthma.

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Background: Parvalbumin and collagen have been identified as cross-reactive allergens for fish allergies. Although doctors realize that various fish elicit allergies, the targets of food allergen labeling laws were only mackerels and salmons in Japan and mackerels in South Korea. This study aimed to reveal the causative species for fish allergy via questionnaires and blood tests. Methods: Questionnaire research was conducted in Japan via the internet concerning allergies for fish- allergic patients or their family members. Next, IgE reactivities and cross-reactivities of 26 fish species were analyzed using sera obtained from 16 Japanese patients who were allergic to fish parvalbumin or collagen by enzyme-linked immunosorbent assay (ELISA) and inhibition ELISA. Results: Questionnaire research revealed that 88% patients cannot eat mackerel and salmon in addition to other fish. In addition, 85% respondents were not satisfied with the current food allergen labeling law. In ELISA analyses, we clarified that pooled serum obtained from patients with fish parvalbumin-specific allergies exhibited IgE reactivity to the extracts of most fish species, and pooled serum obtained from patients with fish collagen-specific allergies displayed IgE reactivity to the extracts of all types of fish. Inhibition ELISA experiments revealed cross-reactivities of parvalbumin or collagen to extracts from all fish tested. Conclusions: Most patients with fish allergies displayed allergic symptoms following the intake of various fish species. In addition, fish parvalbumin and collagen were causative factors of fish allergy and were highly cross-reactive fish panallergens. Therefore, current laws should be revised in Japan and South Korea.

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Background: The chemokine receptor, CC-chemokine receptor 3 (CCR3), and its major ligands, eotaxin, RANTES, and MCP-4, are involved in eosinophil chemotaxis. It is thought that CCR3 plays an important role in the recruitment and activation of eosinophils in nasal polyposis. We examined nasal polyp extract-induced eosinophil chemotaxis and the effect of a CCR3 antagonist using EZ-TAXIScan, a novel real-time chemotaxis assay device. Methods: Nasal polyps were obtained from chronic rhinosinusitis (CRS) patients during surgery. The polyps were homogenized and eotaxin levels in the extracts were measured. Eosinophils were purified from human peripheral blood by the CD16 negative selection method. Nasal polyp extract-induced eosinophil chemotaxis, with or without CCR3 antagonist, was assessed by EZ-TAXIScan. Results: There was a significant positive correlation between the eosinophil counts in nasal polyp and eotaxin levels in the nasal polyp extracts. Using EZ-TAXIScan, eosinophil chemotactic responses were observed following stimulation with nasal polyp extracts. There was a significant positive correlation between the chemotactic index toward the nasal polyp extracts and their eotaxin levels. Nasal polyp extract-induced chemotaxis was completely inhibited by CCR3 antagonist but not by chemoattractant receptor-homologous molecule expressed on Th2 cells (CRTH2) antagonist which inhibited PGD2- induced eosinophil chemotaxis. Conclusions: The CCR3 pathway may play an important role in the pathogenesis of eosinophil recruit ment in nasal polyps through selective eosinophil chemotaxis.

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Background: Cry j 2 and Cha o 2 are major allergens in Japanese cedar (Cryptomeria japonica; CJ) and Japanese cypress (Chamaecyparis obtuse; CO) pollen, respectively. Here, we assessed the epitopes related to the cross-reactivity between Cry j 2 and Cha o 2 using in vitro analyses. Methods: Peptides were synthesized based on Cry j 2 sequential epitopes and relevant Cha o 2 amino acid sequences. Four representative monoclonal antibodies (mAbs) against Cry j 2 were used according to their epitope recognitions. Serum samples were collected from 31 patients with CJ pollinosis. To investigate cross-reactivity between Cry j 2 and Cha o 2, ELISA and inhibition ELISA were performed with mAbs and sera from patients with CJ pollinosis. Results: Two of four mAbs had reactivity to both Cry j 2 and Cha o 2. Of these two mAbs, one mAb (T27) recognized the amino acid sequence ¹⁶⁹KVVNGRTV¹⁷⁶ on Cha o 2. This is related to the core epitope ¹⁶⁹KWVNGREI¹⁷⁶ on Cry j 2, which is an important IgE epitope. In addition, we found that these correlative sequences and purified allergens showed cross-reactivity between Cry j 2 and Cha o 2 in IgE of CJ patients. Conclusions: We demonstrated the importance of ¹⁶⁹KVVNGRTV¹⁷⁶ in Cha o 2 for cross-reactivity with the Cry j 2 epitope ¹⁶⁹KWVNGREI¹⁷⁶, which plays an important role in allergenicity in CJ pollinosis. Our results are useful for the development of safer and more efficient therapeutic strategies for the treatment of CJ and CO pollen allergies.

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Background: We have proposed a new scoring system (Anaphylaxis SCoring Aichi: ASCA) for a quantitative evaluation of the anaphylactic reaction that is observed in an oral food challenge (OFC). Furthermore, the TS/Pro (Total Score of ASCA/cumulative protein dose) can be a marker to represent the overall severity of a food allergy. We aimed to develop a prediction model for a severe allergic reaction that is provoked in a boiled egg white challenge. Methods: We used two separate datasets to develop and validate the prediction model, respectively. The development dataset included 198 OFCs, that tested positive. The validation dataset prospectively included 140 consecutive OFCs, irrespective of the result. A ‘severe reaction’ was defined as a TS/Pro higher than 31 (the median score of the development dataset). A multivariate logistic regression analysis was performed to identify the factors associated with a severe reaction and develop the prediction model. Results: The following four factors were independently associated with a severe reaction: ovomucoid specific IgE class (OM-sIgE: 0-6), aged 5 years or over, a complete avoidance of egg, and a total IgE < 1000 IU/mL. Based on these factors, we made a simple scoring prediction model. The model showed good discrimination in a receiver operating characteristic analysis; area under the curve (AUC) = 0.84 in development dataset, AUC = 0.85 in validation dataset. The prediction model significantly improved the AUC in both datasets compared to OM-sIgE alone. Conclusions: This simple scoring prediction model was useful for avoiding risky OFC.

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Background: Inducible nitric oxide synthase (iNOS) induced by inflammatory cytokines and iNOS activity in bronchial epithelial cells is a major determinant of fractional exhaled nitric oxide (FeNO) levels. The aim of this study was to investigate the association of iNOS promoter gene polymorphisms and FeNO levels in Japanese asthmatics before the introduction of asthma treatment. Methods: Asthmatics were recruited from Fukushima Medical University Hospital. Genotyping of the pentanucleotide repeat (CCTTT)n and seven previously detected single nucleotide polymorphisms (SNPs) in the iNOS promoter lesion was performed. The relationships between the genotypes and FeNO levels before the introduction of asthma treatment were compared. Results: In 91 asthmatics, the number of microsatellite repeats ranged from 9 to 20 and showed a bimodal distribution. According to this distribution, asthmatics were divided into two groups: genotypes with at least one long allele with more than 14 repeats (L/s or L/L) and genotypes with both short alleles with 14 or fewer repeats (s/s). No significant differences were observed in each parameter between the two groups. The mean FeNO level before treatment was significantly higher in the L/s or L/L subjects than in the s/s subjects. After treatment, the lowest FeNO level did not differ between the two groups. Three SNPs detected in the Japanese subjects were not associated with FeNO levels. Conclusions: The number of CCTTT repeats in the iNOS promoter region was associated with FeNO levels in asthmatics before treatment, suggesting the importance of iNOS genotype in the clinical application of FeNO for asthmatics.

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Background: Several guidelines, including the Japanese Pediatric Guideline for the Treatment and Management of Asthma (JPGL), recommend salmeterol/fluticasone combination therapy (SFC) as step 3 to 4 treatment for moderate to severe asthma. However, the optimal step-down approach to SFC remains unclear. In the current study, we examined step-down approaches in asthmatic children whose symptoms had been stabilized by SFC 100/200 μg/day. Methods: This randomized, multicenter, open-label, parallel-group study was conducted over 12 weeks. For step-down therapy, subjects aged 5e15 years were randomly assigned to an SFC group (25/50 μg b.i.d.) or an FP group (100 μg b.i.d.), and treated for 12 weeks. Childhood Asthma Control Test (C-ACT) scores, lung function, and exhaled nitric oxide (FeNO) levels were monitored. Results: Of 131 enrolled subjects, 128 completed the study and were included in the analysis. Decreases in % peak expiratory flow rate and % forced expiratory flow at 50% of vital capacity (V50) were observed in the FP group at each time point. There was a significant difference between the two groups for the change in %V50 from its previous value at each time point. There were no significant changes in FeNO levels (range 15-20 ppb) or C-ACT scores (~26 points) within or between groups. Conclusions: A high level of asthma control was maintained with both approaches. The use of SFC step-down resulted in somewhat better respiratory function, with no worsening of airway inflammation. However, halving the dose of SFC and switching to FP alone are both optimal step-down approaches.

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Background: The Childhood Atopic Dermatitis Impact Scale (CADIS) was developed to measure the impact of AD on QoL in both affected children and their families. However, no scale of this kind exists in Japan. The aims of this study were to validate the Japanese Culturally Modified Version of the CADIS (JCMV-CADIS) and to describe the family impact of children with AD in a Japanese context. Methods: Participants included primary-caregivers for children with AD between 2 and 6 years of age. Interviews were conducted, and new items for the Japanese version were drafted. Reliability and validity were evaluated and compared with the original CADIS, and unique features of the Japanese version were analyzed. Results: Exploratory factor analysis revealed the following factors: “Symptoms” and “Activity Limitations and Behavior” in the Child domain, and “Emotions Related to Social Factors,” “Emotions Related to the Child's Condition,” “Family and Social Function,” “Complexity of Care,” and “Approaches to Management of AD in Daily Life” in the Parent domain. The latter two factors were unique to the JCMV-CADIS and were not derived from the Original. “Emotion” was split into two independent factors. All factors showed good reliability (internal consistency and stability) and validity (concurrent validity and discriminant validity), except for the concurrent validity of “Approaches to Management of AD in Daily Life.” This factor seemed to reflect characteristics similar to the family-related function. Conclusions: The JCMV-CADIS is a QoL scale developed for Japanese children with AD and their families. Further evaluation of clinical applicability is needed.

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Background: Gastroesophageal reflux disease (GERD) is known as a common comorbidity of asthma and chronic cough. The impact of GERD symptoms on cough-specific quality of life (QoL) in patients with asthmatic cough is poorly understood. The aim of this study is to determine the association of GERD symptoms with cough-specific quality of life in patients with cough variant asthma (CVA) using the Leicester Cough Questionnaire (LCQ). Methods: A total of 172 consecutive patients (121 females) with mean cough duration of 45.1 months (range 2-480 months) completed the Japanese version of the LCQ. The Frequency Scale for the Symp- toms of Gastroesophageal reflux was administered to assess symptoms of acid-reflux and dysmotility. A range of clinical variables that may determine cough-specific QoL (LCQ) were estimated. Results: The mean LCQ scores was 12.9 (SD 3.5), consistent with severe impairment in QoL. Female gender, symptoms of gastroesophageal dysmotility, sensitization to allergens (house dust and Japanese cedar pollen) and the number of sensitized allergens were associated with lower LCQ scores (i.e. impaired cough-specific QoL) in univariate regression analysis. Acid-reflux symptoms, airway hyper- responsiveness, fractional exhaled nitric oxide, and sensitization to molds were unrelated to the LCQ score. After adjustment for gender, symptoms of gastroesophageal dysmotility was the only significant determinant of impaired cough-specific QoL accounting for 23% of the variance. Conclusions: Cough-specific QoL is severely impaired in patients with CVA. Symptoms of gastroesoph- ageal dysmotility are an independent predictor of cough-specific QoL of patients with CVA.

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Background: The prevalence of maternal oral contraceptive pills (OCP) use and that of childhood asthma are high in western countries. The aim of this study is to examine the association of OCP use with childhood wheeze and allergic diseases in Japan. Methods: Relevant data were extracted from a hospital based birth cohort study named as Tokyo-Children's Health, Illness and Development Study (T-CHILD) of which questionnaire conducted during pregnancy included maternal history and duration of OCP use. To identify wheeze and allergic diseases in the children, the questionnaire of the International Study of Asthma and Allergies in Childhood (ISAAC) was used. Logistic regression models were applied to estimate those association and adjustments were made for maternal history of allergy, maternal education level, maternal age at pregnancy, maternal BMI, maternal smoking during pregnancy, mode of delivery, gestational age at delivery, daycare attendance, number of previous live births, and gender of child. Results: OCP use was associated with ever wheeze (adjusted odds ratio [aOR], 1.62; 95% confidence interval [CI], 1.10-2.40), current wheeze (aOR, 1.59; 95% CI, 1.01-2.50), ever asthma (aOR, 1.65; 95% CI, 1.02 -2.65), and ever rhinitis (aOR, 1.90; 95% CI, 1.30-2.80). Compared with no prior OCP use, using OCP for more than three months statistically increased the odds of ever wheeze (P = 0.012), current wheeze (P = 0.035), and ever rhinitis (P = 0.002). Conclusions: Our findings suggest that maternal OCP use has a role in the development of wheeze, asthma and rhinitis in children. Extended use of OCP is likely to increase the risk of wheeze and rhinitis.

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