Symbiotic riboflavin degradation by Microbacterium and Nocardioides bacteria.

Unlike its biosynthetic mechanisms and physiological function, current understanding of riboflavin degradation in soil is limited to a few bacteria that decompose it to lumichrome. Here, we isolated six Microbacterium and three Nocardioides strains. These strains utilized riboflavin and lumichrome, respectively, as carbon sources. Among these strains, we identified Microbacterium paraoxydans R16 (R16) and Nocardioides nitrophenolicus L16 (L16), which were isolated form the same enrichment culture. Co-cultured R16 and L16 reconstituted a riboflavin-degrading interspecies consortium, in which the R16 strain degraded riboflavin to lumichrome and ᴅ-ribose. The L16 strain utilized the lumichrome as a carbon source, indicating that R16 is required for L16 to grow in the consortium. Notably, rates of riboflavin degradation and growth were increased in co-cultured, compared with monocultured R16 cells. These results indicated that a beneficial symbiotic interaction between M. paraoxydans R16 and N. nitrophenolicus L16 results in the ability to degrade riboflavin.

Two-Component Flavin-Dependent Riboflavin Monooxygenase Degrades Riboflavin in Devosia riboflavina.

The actinobacterium Microbacterium maritypicum splits riboflavin (vitamin B2) into lumichrome and d-ribose. However, such degradation by other bacteria and the involvement of a two-component flavin-dependent monooxygenase (FMO) in the reaction remain unknown. Here we investigated the mechanism of riboflavin degradation by the riboflavin-assimilating alphaproteobacterium Devosia riboflavina (formerly Pseudomonas riboflavina). We found that adding riboflavin to bacterial cultures induced riboflavin-degrading activity and a protein of the FMO family that had 67% amino acid identity with the predicted riboflavin hydrolase (RcaE) of M. maritypicum MF109. The D. riboflavina genome clustered genes encoding the predicted FMO, flavin reductase (FR), ribokinase, and flavokinase, and riboflavin induced their expression. This finding suggests that these genes constitute a mechanism for utilizing riboflavin as a carbon source. Recombinant FMO (rFMO) protein of D. riboflavina oxidized riboflavin in the presence of reduced flavin mononucleotide (FMN) provided by recombinant FR (rFR), oxidized FMN and NADH, and produced stoichiometric amounts of lumichrome and d-ribose. Further investigation of the enzymatic properties of D. riboflavina rFMO indicated that rFMO-rFR coupling accompanied O2 consumption and the generation of enzyme-bound hydroperoxy-FMN, which are characteristic of two-component FMOs. These results suggest that D. riboflavina FMO is involved in hydroperoxy-FMN-dependent mechanisms to oxygenize riboflavin and a riboflavin monooxygenase is necessary for the initial step of riboflavin degradation.IMPORTANCE Whether bacteria utilize either a monooxygenase or a hydrolase for riboflavin degradation has remained obscure. The present study found that a novel riboflavin monooxygenase, not riboflavin hydrolase, facilitated this process in D. riboflavina The riboflavin monooxygenase gene was clustered with flavin reductase, flavokinase, and ribokinase genes, and riboflavin induced their expression and riboflavin-degrading activity. The gene cluster is uniquely distributed in Devosia species and actinobacteria, which have exploited an environmental niche by developing adaptive mechanisms for riboflavin utilization.

Maintenance treatment using abatacept with dose reduction after achievement of low disease activity in patients with rheumatoid arthritis (MATADOR) - A prospective, multicenter, single arm pilot clinical trial.

OBJECTIVES: To preliminarily evaluate the feasibility of maintenance therapy with reduced dose of intravenous abatacept (ABT) to 250 mg/body/month after achieving remission or low disease activity (LDA). PATIENTS AND METHODS: RA patients treated with ABT at 13 sites were enrolled in this prospective interventional pilot study during the period between March 2013 and March 2015. Inclusion criteria were (1) age at 20 years or older, (2) under treatment with monthly intravenous ABT at approved doses, (3) DAS28-CRP lower than 2.7 at least for 6 months, (4) agreed to join this trial with written informed consent and (5) body weight under 125 kg. Enrolled patients were maintained with intravenous monthly ABT at a reduced dose of 250 mg/body (MATADOR protocol). The primary end point was the proportion of the patients continued with MATADOR protocol at week 48. MATADOR protocol was discontinued upon disease flare or other reasons such as patients' request or severe adverse event (AE). Disease activities and structural changes were also evaluated. RESULTS: Fifty-three patients fulfilled the entry criteria and were followed for 1-year. MATADOR protocol was continued for 1-year in 43 (81%) of the evaluated patients. Three patients experienced severe AEs. Mean DAS28-CRP and remission rate were 1.56 and 88% when ABT reduced and 1.80 and 81% at 1-year, respectively. Structural remission was achieved in 34 out of 42 evaluated patients. CONCLUSIONS: Reduced dose of intravenous ABT was proposed as a feasible choice for maintenance therapy for RA after achievement of remission/LDA, although further randomized trials would be awaited.

Down-Regulation of Soluble α-Klotho is Associated with Reduction in Serum Irisin Levels in Chronic Obstructive Pulmonary Disease.

PURPOSE: The klotho gene was originally identified as a putative aging-suppressor gene. Klotho-depleted mice display a shortened life span and exhibit a variety of premature aging-related phenotypes such as pulmonary emphysema and sarcopenia. This study was designed to determine the roles of secreted-type klotho protein on lung and skeletal muscle in chronic obstructive pulmonary disease (COPD). METHODS: Serum α-klotho and irisin levels were assayed in 16 non-smokers, 13 smokers without COPD, and 24 smokers with COPD. Moreover, we examined correlations between soluble α-klotho levels and the results of lung function test, cardiopulmonary exercise test (CPET), and skeletal muscle function in smokers with COPD. RESULTS: Soluble α-klotho levels were significantly lower in smokers with COPD compared to non-smokers and smokers without COPD. In smokers with COPD, those levels did not significantly correlate with any parameters of lung function test. In CPET, peak VO2 significantly correlated with FEV1 (% predicted) (r = 0.76, p = 0.0003) and DLCO (% predicted) (r = 0.62, p = 0.003). In contrast, soluble α-klotho levels did not significantly correlate with peak VO2. Irisin levels were also significantly lower in smokers with COPD. Moreover, there was a significant correlation between soluble α-klotho and serum irisin levels (r = 0.61, p = 0.004). CONCLUSIONS: Our findings could provide a critical first step to understanding the impacts of soluble α-klotho on skeletal muscle in COPD and may lead to the identification of new molecular targets for the treatment of COPD.

Impaired nuclear factor erythroid 2-related factor 2 expression increases apoptosis of airway epithelial cells in patients with chronic obstructive pulmonary disease due to cigarette smoking.

BACKGROUND: Cigarette smoking-induced oxidative stress is known to be a key mechanism in COPD pathogenesis. Nuclear factor erythroid 2-related factor 2 (Nrf2) is a central transcription factor that regulates the antioxidant defense system. The aim of this study was to compare Nrf2 expression in COPD subjects and control subjects, and to determine the role of Nrf2 in protecting against oxidative stress-induced apoptosis. METHODS: We enrolled 8 COPD subjects and 7 control subjects in this study. We performed bronchial brushing by bronchoscopy and obtained bronchial epithelial cells from the airways. Nrf2 expression in bronchial epithelial cells was evaluated by real-time PCR and Western blotting. We examined the effect of 10 or 15 % cigarette smoke extract (CSE) induced A549 cells apoptosis using a time-lapse cell imaging assay with caspase-3/7 activation detecting reagent and performed Terminal deoxynucleotidyltransferase-mediated dUTP nick end labelling assay for confirming A549 cells apoptosis. We also examined the effects of Nrf2 knockdown and, 0.1, 0.5, and 1.0 mM N-acetyl cysteine on CSE-induced apoptosis. Statistical analyses were performed using t-test, paired t-test or an analysis of variance followed by the Tukey-Kramer method. RESULTS: Nrf2 mRNA expression in COPD subjects was significantly lower than that in control subjects and Nrf2 mRNA were negatively correlated with pack year. Nrf2 protein in COPD subjects was significantly lower than that in control subjects. CSE-induced A549 cells apoptosis was increased in a time-, concentration-dependent manner, and was significantly increased by Nrf2 knockdown. N-acetyl cysteine significantly ameliorated CSE-induced apoptosis. CONCLUSIONS: Nrf2 expression was lower in COPD patients than in control subjects. Nrf2 might have a protective role against apoptosis caused by CSE-induced oxidative stress. These results suggest an involvement of Nrf2 in COPD and administration of antioxidants to patients with COPD might be a basic therapeutic option.

Up-regulation of the MicroRNA miR-30c Induced by High Mobility Group Box 1 in A549 Cells Used as an Alveolar Epithelial Model.

Background: MicroRNAs (miRNAs) have been reported to be involved in multiple diseases, including chronic obstructive pulmonary disease (COPD), a progressive disease in which alveolar apoptosis may play a role. We hypothesized that miRNAs are associated with the response to injury. induced by high mobility group box 1 (HMGB1), a cytokine crucial for the development of COPD, and studied the potential link between HMGB1 and miRNAs. Materials and Methods: A549 cells were stimulated with recombinant HMGB1. RNA and protein were extracted and culture supernatants were collected. Molecules downstream of HMGB1 signaling were analyzed by reverse transcription polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA). Expression levels of miRNA were analyzed by quantitative RT-PCR. Cellular injury was evaluated by western blotting of relevant proteins. Apoptosis was evaluated by in situ terminal deoxynucleotidyl transferase dUTP nick end-labeling (TUNEL). Results: HMGB1 treatment of A549 cells resulted in the up-regulation of tumor necrosis factor (TNF)-α and macrophage inflammatory protein (MIP)-2 mRNAs and over expression of matrix metalloprotease (MMP)-7 protein in the supernatant. The miRNA miR-30c was also up-regulated in response to HMGB1 treatment. Cellular injury and apoptosis were observed following HMGB1 treatment, as demonstrated by the oyerexpression of cyclin A2 (CCNA2) and phosphatase and tensin homolog (PTEN) proteins and-b'y decreased levels of pro-caspase-7 protein. The TUNEL assay showed that A549 cells with HMGB1 stimulation underwent apoptosis. Conclusions: Up-regulation of miR-30c and apoptosis of A549 cells were observed following HMGB1 stimulation. Our model demonstrates the potential for utilization of HMGB1 and miR-30c in further studies of alveolar apoptosis in COPD.

Clinical and structural remission rates increased annually and radiographic progression was continuously inhibited during a 3-year administration of tocilizumab in patients with rheumatoid arthritis: A multi-center, prospective cohort study by the Michinoku Tocilizumab Study Group.

OBJECTIVE: To evaluate the clinical and structural efficacy of tocilizumab (TCZ) during its long-term administration in patients with rheumatoid arthritis (RA). METHODS: In total, 693 patients with RA who started TCZ therapy were followed for 3 years. Clinical efficacy was evaluated by DAS28-ESR and Boolean remission rates in 544 patients. Joint damage was assessed by calculating the modified total Sharp score (mTSS) in 50 patients. RESULTS: When the reason for discontinuation was limited to inadequate response or adverse events, the 1-, 2-, and 3-year continuation rates were 84.0%, 76.8%, and 72.2%, respectively. The mean DAS28-ESR was initially 5.1 and decreased to 2.5 at 6 months and to 2.2 at 36 months. The Boolean remission rate was initially 0.9% and increased to 21.7% at 6 months and to 32.2% at 36 months. The structural remission rates (ΔmTSS/year ≤ 0.5) were 68.8%, 78.6%, and 88.9% within the first, second, and third years, respectively. The structural remission rate at 3 years (ΔmTSS ≤ 1.5) was 66.0%, and earlier achievement of swollen joint count (SJC) of 1 or less resulted in better outcomes. CONCLUSIONS: TCZ was highly efficacious, and bone destruction was strongly prevented. SJC was an easy-to-use indicator of joint destruction.

Irisin, a newly discovered myokine, is a novel biomarker associated with physical activity in patients with chronic obstructive pulmonary disease.

BACKGROUND AND OBJECTIVE: Irisin is a recently identified hormone secreted by skeletal myocytes, which has been proposed to mediate the beneficial effects of exercise. Physical activity has been emphasized as one of the principal targets of the treatment for chronic obstructive pulmonary disease (COPD). This study was designed to evaluate the possibility of using serum irisin level as a novel biomarker associated with physical activity in patients with COPD. METHODS: We measured the serum irisin level in 72 COPD patients and 27 control subjects, and investigated its correlation to pulmonary function parameters, exercise capacity and physical activity level. In addition, we analysed the effects of acute and chronic exercise on serum irisin level. RESULTS: Fat-free mass index was not significantly different between the two study groups. However, lower serum irisin level was observed in COPD patients than in the control subjects (COPD patients: median (interquartile range) 31.6 (22.7-40.4) ng/mL; control subjects: 50.7 (39.3-65.8) ng/mL; P < 0.001). The serum irisin level did not significantly correlate with any pulmonary function parameters and 6-min walk distance. However, serum irisin level was associated with the physical activity level in all subjects. In COPD patients, acute exercise did not affect serum irisin level, but an 8-week exercise training was linked to the significant increase in its level. CONCLUSIONS: Circulating irisin could be used to evaluate physical activity in COPD patients and increased after an 8-week exercise training. Serum irisin level may prove to be a valuable biomarker in clinical follow up of COPD.

Pentraxin-3 as a Biomarker for Febrile Neutropenia in Patients with Lung Cancer.

BACKGROUND: Pentraxin-3 (PTX3) is a newly discovered biomarker for various inflammatory conditions. We measured plasma PTX3 levels in patients with febrile neutropenic lung cancer and examined the utility of PTX3 levels as a biomarker for febrile neutropenia. METHODS: Fourteen patients with febrile neutropenic lung cancer were enrolled in the study. In addition, 10 untreated lung cancer patients and 12 healthy adults were enrolled as a disease control group and a healthy control group, respectively. On the day of onset of febrile neutropenia (day 1) and days 3 and 7, PTX3 and C-reactive protein (CRP) levels were measured. In the control groups, PTX3 and CRP levels were measured once. RESULTS: On day 1, plasma CRP levels in febrile neutropenia during chemotherapy or chemoradiotherapy for lung cancer (FN/LC) patients (8.11 ± 6.42 mg/dL) were significantly higher than those in healthy controls (HC) and chemotherapy/chemoradiotherapy-naïve lung cancer (CN/LC) patients (p < 0.05). However, CRP levels of the CN/LC group (0.33 ± 0.02 mg/dL) were also significantly higher than those of the HC group (0.07 ± 0.09 mg/dL) (p < 0.05). In contrast, plasma PTX3 levels of the FN/LC group (6.14 ± 5.28 ng/mL) were significantly higher than those of the HC and CN/LC groups on day 1 (p < 0.05), but PTX3 levels of the CN/LC group (1.60 ± 0.64 ng/mL) were not significantly higher than those of the HC group (1.05 ± 0.25 ng/mL). In the FN/LC group, PTX3 levels peaked immediately on day 1. CONCLUSIONS: PTX3 may be a useful biomarker for diagnosis of FN in patients with LC.

Percutaneous transluminal pulmonary valvuloplasty in a child with tricuspid atresia, ventricular septal defect, and severe pulmonary valve stenosis: usefulness of the femoral artery approach.

Percutaneous transluminal pulmonary valvuloplasty may be indicated in not only isolated pulmonary valve stenosis, but also complex congenital heart diseases. Because palliative surgery for increasing pulmonary blood flow entails a risk of scar formation and immediate postoperative complications, catheter intervention is preferred, if possible. However, an acute-angled, twisted, or tortuous access route or a small valve orifice occasionally makes it difficult for the catheter to reach or cross the target. We succeeded in performing this intervention for such a complex stenosis effectively and safely in a patient with tricuspid atresia, ventricular septal defect (VSD), and severe pulmonary valve stenosis, thereby evading surgery. In previous reports, the catheter for this cardiac anomaly was accessed via the femoral vein. In the present case, the catheter was advanced through the femoral artery via the aorta, left ventricle, VSD, and right ventricle to the pulmonary valve, using a micro-catheter in a telescopic manner, in combination with a coronary balloon dilatation catheter. This maneuver, which has not been reported previously, made it much easier to perform the procedure as compared to the femoral vein approach, despite the acute turn and the pinhole orifice. Moreover, reported complications of the femoral vein approach, including bradycardia, hypotension, and valve regurgitation, were not observed in this case. We conclude that the femoral artery approach can be a safe and effective alternative in patients for whom a more conventional procedure has been unsuccessful.

Epistatic effects of multiple receptor genes on pathophysiology of asthma - its limits and potential for clinical application.

To date, genome-wide association studies (GWAS) permit a comprehensive scan of the genome in an unbiased manner, with high sensitivity, and thereby have the potential to identify candidate genes for the prevalence or development of multifactorial diseases such as bronchial asthma. However, most studies have only managed to explain a small additional percentage of hereditability estimates, and often fail to show consistent results among studies despite large sample sizes. Epistasis is defined as the interaction between multiple different genes affecting phenotypes. By applying epistatic analysis to clinical genetic research, we can analyze interactions among more than 2 molecules (genes) considering the whole system of the human body, illuminating dynamic molecular mechanisms. An increasing number of genetic studies have investigated epistatic effects on the risk for development of asthma. The present review highlights a concept of epistasis to overcome traditional genetic studies in humans and provides an update of evidence on epistatic effects on asthma. Furthermore, we review concerns regarding recent trends in epistatic analyses from the perspective of clinical physicians. These concerns include biological plausibility of genes identified by computational statistics, and definition of the diagnostic label of 'physician-diagnosed asthma'. In terms of these issues, further application of epistatic analysis will prompt identification of susceptibility of diseases and lead to the development of a new generation of pharmacological strategies to treat asthma.

Analysis of the contributing factors to airway hyperresponsiveness by a forced oscillation technique in patients with asthma.

BACKGROUND: Forced oscillation technique (FOT) is increasingly used to obtain much information on the state of the respiratory system. However, there are little data about FOT parameters on methacholine provocation test in adult asthma. This study was designed to determine the physiological implications of FOT parameters during methacholine provocation and analyze the major contributing factors to airway hyperresponsiveness (AHR) in asthma. METHODS: Spirometry and FOT were performed in 22 asthmatic patients and 21 normal control subjects before and after provocation with a maximal dose of methacholine. RESULTS: In asthmatic patients, the percent increase in resistance at 5 Hz (R5) and resistance at 20 Hz (R20) after the methacholine provocation was 70 [45-93] % and 16 [5-23] %. The percent change in R20 was not significantly correlated with the percent change in FVC or FEV1. Similarly, the percent change in R5 was not significantly correlated with the percent change in FEV1, but was significantly correlated with the percent change in FVC. Moreover, the percent change in R5 was significantly correlated with the closing index (r = 0.55, p = 0.01). In addition, AHR to methacholine was closely correlated with the percent change in R5 (r = -0.71, p = 0.001). CONCLUSIONS: Simultaneous measurement of FOT and bronchial challenge test provide meaningful information, and greater change in R5 may represent exaggerated response of small airways in asthmatic patients. This study will provide new insights into the physiological implications of each FOT parameter in asthmatic patients.

Feasibility of methotrexate discontinuation following tocilizumab and methotrexate combination therapy in patients with long-standing and advanced rheumatoid arthritis: a 3-year observational cohort study.

OBJECTIVES: Methotrexate (MTX) is associated with extensive side effects, including myelosuppression, interstitial pneumonia, and infection. It is, therefore, critical to establish whether its administration is required after achieving remission with tocilizumab (TCZ) and MTX combination therapy in patients with rheumatoid arthritis (RA). Therefore, the aim of this multicenter, observational, cohort study was to evaluate the feasibility of MTX discontinuation for the safety of these patients. METHODS: Patients with RA were administered TCZ, with or without MTX, for 3 years; those who received TCZ+MTX combination therapy were selected. After remission was achieved, MTX was discontinued without flare development in one group (discontinued [DISC] group, n = 33) and continued without flare development in another group (maintain [MAIN] group, n = 37). The clinical efficacy of TCZ+MTX therapy, patient background characteristics, and adverse events were compared between groups. RESULTS: The disease activity score in 28 joints-erythrocyte sedimentation rate (DAS28-ESR) at 3, 6, and 9 months was significantly lower in the DISC group (P < .05, P < .01, and P < .01, respectively). Further, the DAS28-ESR remission rate at 6 and 9 months and Boolean remission rate at 6 months were significantly higher in the DISC group (P < .01 for all). Disease duration was significantly longer in the DISC group (P < .05). Furthermore, the number of patients with stage 4 RA was significantly higher in the DISC group (P < .01). CONCLUSIONS: Once remission was achieved, MTX was discontinued in patients who responded favorably to TCZ+MTX therapy, despite the prolonged disease duration and stage progression.

The endosomal Na(+)/H(+) exchanger contributes to multivesicular body formation by regulating the recruitment of ESCRT-0 Vps27p to the endosomal membrane.

Multivesicular bodies (MVBs) are late endosomal compartments containing luminal vesicles (MVB vesicles) that are formed by inward budding of the endosomal membrane. In budding yeast, MVBs are an important cellular mechanism for the transport of membrane proteins to the vacuolar lumen. This process requires a class E subset of vacuolar protein sorting (VPS) genes. VPS44 (allelic to NHX1) encodes an endosome-localized Na(+)/H(+) exchanger. The function of the VPS44 exchanger in the context of vacuolar protein transport is largely unknown. Using a cell-free MVB formation assay system, we demonstrated that Nhx1p is required for the efficient formation of MVB vesicles in the late endosome. The recruitment of Vps27p, a class E Vps protein, to the endosomal membrane was dependent on Nhx1p activity and was enhanced by an acidic pH at the endosomal surface. Taken together, we propose that Nhx1p contributes to MVB formation by the recruitment of Vps27p to the endosomal membrane, possibly through Nhx1p antiporter activity.

Validity of HMGB1 measurement in epithelial lining fluid in patients with COPD.

BACKGROUND: It has been known that high-mobility group box 1 (HMGB1) plays an important role in the pathogenesis of various inflammatory disorders in the lung. We attempted to determine the validity of measurement of HMGB1 levels in epithelial lining fluid (ELF) from patients with chronic obstructive pulmonary disease (COPD). MATERIALS AND METHODS: We measured HMGB1 levels in ELF separately obtained from central or peripheral airways using a bronchoscopic microsampling technique in 14 non-smokers, 13 smokers without COPD and 30 smokers with COPD. We also evaluated whether those levels were correlated with the indexes of pulmonary function and grade of low-attenuation area (LAA) on high-resolution computed tomographic scans. RESULTS: HMGB1 levels in ELF from central airways did not significantly differ among the three groups. However, HMGB1 levels in peripheral airways were significantly higher in COPD patients than in non-smokers and smokers without COPD. Both the concentrations of interleukin-8 and human polymorphonuclear elastase in peripheral airways were also significantly higher in COPD patients. Moreover, those levels were significantly correlated with HMGB1 level. In addition, HMGB1 level in peripheral airways was closely correlated with the degree of airflow obstruction and grade of LAA in COPD patients. CONCLUSIONS: HMGB1 levels in peripheral airways were elevated in smokers without COPD, as compared with non-smokers, and those levels were further augmented in COPD patients. Those levels were associated with the severity of COPD. Therefore, HMGB1 in peripheral airways may be a potentially interesting target for new pharmacological treatments in COPD patients.

Association of airway pentosidine levels with bronchodilator response mediated by salbutamol administration in asthmatic patients.

BACKGROUND: Recently, increased levels of pentosidine, an intermolecular cross-linking type of advanced glycation end products, are observed in the airways of asthmatic patients. This study was designed to determine whether differences in bronchodilator response among individuals with asthma are attributable to pentosidine levels in their airways. METHODS: Fifty-six asthmatic patients (21 with airway obstruction, 35 without airway obstruction) and 10 normal controls were included in this study. For asthmatic patients, we evaluated the spontaneous reversibility of airway obstruction or the reversibility that can be obtained after methacholine provocation. And we also measured pentosidine levels and percentage of sputum eosinophils in induced sputum, and exhaled nitric oxide (NO) levels. RESULTS: The pentosidine levels did not significantly differ between the two asthmatic subgroups with and without airway obstruction. In asthmatic patients without airway obstruction, airway hyperresponsiveness to methacholine (PC20 methacholine) was significantly correlated with sputum eosinophils and exhaled NO levels. In contrast, PC20 methacholine was not significantly correlated with pentosidine levels. In asthmatic patients with or without airway obstruction, bronchodilator response was not significantly correlated with sputum eosinophils and exhaled NO levels. However, bronchodilator response was closely correlated with pentosidine levels (asthmatics without airway obstruction: r = -0.54, p = 0.002; asthmatics with airway obstruction: r = -0.48, p = 0.03). CONCLUSIONS: Our results showed that pentosidine might be a potential biomarker reflecting the reduced bronchodilator response in asthma. This study will provide new insights into the mechanisms underlying persistent airway obstruction.

Potential roles of pentosidine in age-related and disease-related impairment of pulmonary functions in patients with asthma.

BACKGROUND: Pentosidine is well established as an intermolecular cross-linking type of advanced glycation end products, and it accumulates with aging in various connective tissues. OBJECTIVE: To determine whether pentosidine contributes to age-related and disease-related impairment of pulmonary functions in patients with asthma. METHODS: We measured pentosidine levels in induced sputum from young to elderly patients with asthma and assessed the slope of the nitrogen (N(2)) alveolar plateau (delta N(2)), closing volume (CV), and closing capacity (CC) from a nitrogen washout curve in a single breath. RESULTS: Pentosidine levels in induced sputum were significantly higher in patients with asthma than in normal controls (patients with asthma: median, 20.1, interquartile range, 16.7-26.5 ng/mL; normal controls: median, 3.0, interquartile range, 0.7-7.5 ng/mL; P < .001). The levels were closely correlated with age in both normal controls and patients with asthma. However, the slope of age-related increase in pentosidine levels was markedly steeper in patients with asthma than in normal controls. CV/vital capacity, CC/total lung capacity, and delta N(2) increased with aging in both normal controls and patients with asthma. Moreover, in each range of age (21-40, 41-60, 61-80 years), CV/vital capacity, CC/total lung capacity, and delta N(2) were significantly higher in patients with asthma than in normal controls. In addition, pentosidine levels in patients with asthma were closely correlated with each of these variables. CONCLUSION: Our results demonstrated the association between sputum levels of pentosidine and age-related small airways function in both normal controls and patients with asthma. Moreover, the age-related increase in pentosidine levels was more pronounced in patients with asthma. These findings will herald new era in the pathophysiology of elderly asthma.

Characteristics of young atopic adults with self-reported past wheeze and airway hyperresponsiveness.

BACKGROUND: The present study aimed to illustrate clinical characteristics of spirometric measures and allergy sensitisation among young atopic adults who reported wheezing episodes before adulthood but were not diagnosed with asthma by physicians and have no current wheeze symptoms (self-reported past-wheezers), especially those who exhibited airway hyperresponsiveness (AHR). METHODS: Fifty self-reported past-wheezers were divided into two groups according to AHR to methacholine. Spirometric functions and blood atopic parameters were compared in these groups with those in 25 age-matched atopic adults with a history of childhood asthma diagnosed by specialists but have no current wheeze symptoms (past-asthmatics) and in 60 counterparts without a previous and current wheezing episode (never-wheezers). RESULTS: Twenty-one of the 50 past-wheezers exhibited AHR (PC(20) < 8 mg/ml). Levels of spirometric function and allergic sensitization in both past-wheezer groups were intermediate between those in never-wheezers and past-asthmatics. Lower FEV(1) and FEF(25-75) values (% predicted) were observed in self-reported past-wheezers with AHR relative to those without AHR. More blood eosinophils and higher serum levels of total IgE and IgE specific to house dust mites were observed in self-reported past-wheezers with AHR relative to those without AHR. CONCLUSIONS: Our findings raise the possibility that self-reported past-wheezers with AHR might form a distinct subgroup with features similar to past-asthmatics, which is one of the risk groups for adult asthma.

Idiopathic Obliterative Bronchiolitis in a Young Woman: A Rare Case of a Transbronchial Lung Biopsy Contributing to the Diagnosis.

Idiopathic obliterative bronchiolitis (OB) is a rare disease that usually requires a surgical lung biopsy. A 25-year-old woman with progressive exertional dyspnea for several months showed a severe mixed restrictive and obstructive pattern on spirometry. Chest computed tomography showed a mosaic pattern, and pulmonary ventilation-perfusion scintigraphy showed a matched defect. The bronchoscopic specimens obtained from both the alveolar and bronchiolar regions of the predicted lesion area contributed to the diagnosis of OB. She had no underlying causes of secondary OB, and she was diagnosed with idiopathic OB. Since lung transplantation was indicated, she was referred to a lung transplantation-certified hospital.

Altered motor activity of alternative splice variants of the mammalian kinesin-3 protein KIF1B.

Several mammalian kinesin motor proteins exist as multiple isoforms that arise from alternative splicing of a single gene. However, the roles of many motor protein splice variants remain unclear. The kinesin-3 motor protein KIF1B has alternatively spliced isoforms distinguished by the presence or absence of insertion sequences in the conserved amino-terminal region of the protein. The insertions are located in the loop region containing the lysine-rich cluster, also known as the K-loop, and in the hinge region adjacent to the motor domain. To clarify the functions of these alternative splice variants of KIF1B, we examined the biochemical properties of recombinant KIF1B with and without insertion sequences. In a microtubule-dependent ATPase assay, KIF1B variants that contained both insertions had higher activity and affinity for microtubules than KIF1B variants that contained no insertions. Mutational analysis of the K-loop insertion revealed that variants with a longer insertion sequence at this site had higher activity. However, the velocity of movement in motility assays was similar between KIF1B with and without insertion sequences. Our results indicate that splicing isoforms of KIF1B that vary in their insertion sequences have different motor activities.