Toxicokinetics of methylmercury in diabetic KK-Ay mice and C57BL/6 mice.

We compared the toxicokinetics of methylmercury (MeHg) in KK-Ay type 2 diabetic mice and C57BL/6J mice to evaluate how metabolic changes associated with diabetes affect MeHg toxicokinetics. A single dose of MeHg (0.2, 1, or 5 mg mercury/kg) was administered orally to 12-week-old KK-Ay and C57BL/6J male mice. Total mercury concentrations in plasma, blood cells, whole blood, and tissues (brain, kidneys, liver, and pancreas) were measured after 4, 7, 11, and 14 days. The volume of distribution/bioavailability and the elimination rate constant per day were higher in KK-Ay mice, while the terminal elimination half-life was lower in almost all samples of KK-Ay mice. The area under the curve was lower in all blood and almost all tissue samples from KK-Ay mice. Total clearance/bioavailability was lower in all blood and tissue samples of KK-Ay mice at all MeHg doses. These results indicate that MeHg is more rapidly absorbed by, and eliminated from, the blood cells, brain, liver, kidney, and pancreas of KK-Ay mice under the experimental conditions. Different patterns of tissue-to-plasma and tissue-to-whole blood partition coefficients suggest that notable differences in MeHg transfer between plasma and blood cells affect its distribution in tissues of the two mouse strains. These findings are useful to understand the selective distribution of MeHg to target organs and the sensitivity to MeHg in pathological states.

Melinjo (Gnetum gnemon) extract intake during lactation stimulates hepatic AMP-activated protein kinase in offspring of excessive fructose-fed pregnant rats.

Excessive maternal fructose intake during pregnancy and in early postnatal life has metabolic consequences for the offspring. We investigated the effects of melinjo (Gnetum gnemon) extract (MeE) intake during lactation on the expression and phosphorylation of adenosine monophosphate-activated protein kinase (AMPK) in the liver of offspring from excessive fructose-fed pregnant dams. Pregnant Wistar rats received a normal diet and 100g/L fructose solution during gestation ad libitum. At delivery, dams were divided into two groups: a control diet (FC) or a 0.1% MeE-containing diet (FM) fed during lactation. The dams that were not treated with fructose were fed a control diet (CC). At postnatal week 3, some pups were sacrificed, while the remaining continued to receive a normal diet and were sacrificed at week 17. Blood chemistry and phosphorylation levels of AMPK and acetyl-coenzyme A carboxylase (ACC) were evaluated. Plasma glucose levels in FC female offspring increased compared to that receiving CC at weeks 3 and 17; however, the levels in FM female offspring decreased at week 17. The insulin levels in FM female offspring decreased significantly compared to that in FC female offspring at week 3. Hepatic AMPK phosphorylation was upregulated in FM offspring at week 3 and in female, but not male, offspring at week 17. ACC phosphorylation in FM female offspring was upregulated at week 17. Our results suggest that maternal MeE intake during lactation may modulate the hepatic AMPK pathways in female offspring.

Association of COPD exacerbation frequency with gene expression of pattern recognition receptors in inflammatory cells in induced sputum.

BACKGROUND: Bacteria and viruses are major causes of chronic obstructive pulmonary disease (COPD) exacerbations. Molecular components of these pathogens are recognized by pattern-recognition receptors (PRRs) expressed by various cells in the airway, which leads to initiation of inflammatory processes. Expression levels of PRRs in airway inflammatory cells are expected to affect susceptibility to COPD exacerbation. AIMS: This prospective observational study was conducted to detect any association between exacerbation and PRR expression. METHODS: Thirty-one male COPD patients were recruited. At baseline, clinical history, lung function measurements, peripheral blood samples and induced sputum were obtained. Using sputum samples, we performed gene expression analysis of TLR2, TLR3, TLR4, NOD1, NOD2, RIG-I and MDA-5 by quantitative reverse transcription-polymerase chain reaction in addition to quantitative bacterial culture. COPD exacerbations were assessed based on Anthonisen's criteria using symptom diaries for the following 1-year period. RESULTS: During 1-year follow-up period, 13 patients experienced at least one exacerbation, but 18 patients did not. Those with exacerbations tended to be more severe COPD and showed larger neutrophil fraction in their induced sputum. Among PRRs, only TLR3 gene expression was increased in COPD patients with exacerbation compared with those without exacerbations. Multivariate logistic regression analysis including neutrophil fraction and TLR3 gene expression as predictor variables demonstrated that only an increase of neutrophil fraction, but not TLR3 gene expression, was a significant predictor for COPD exacerbation. CONCLUSION: TLR3 expression in inflammatory cells might affect the susceptibility to COPD exacerbation.

Surveys on the competencies of specialist occupational physicians and effective methods for acquisition of competencies in Japan.

OBJECTIVES: The aim of this study was to study the necessary competencies for specialist occupational physicians in Japan and the effective training methods for acquiring them. METHODS: A competency list (61 items) was developed for the questionnaires in the study by making use of existing competency lists from the Japan Society for Occupational Health (JSOH) as well as lists from the US and Europe. Certified senior occupational physicians (CSOPs) in the certification program of the JSOH completed a questionnaire on the necessary competencies. Examiners of the examination for certified occupational physicians (COPs) completed another questionnaire on effective training methods. RESULTS: All 61 competencies in the questionnaires were evaluated as "necessary". Some of the competencies in the list from the JSOH were evaluated lower than the items added from the American and European lists. When the respondents were categorized into a "practical group", the members of which mainly provided occupational health services, an "academic group", the members of which belonged to research or education institutes such as medical schools, and all others, the practical group evaluated some competencies significantly higher than the academic group, particularly those related to work accommodation. Among three options for training methods, the most effective methods were lectures and textbooks for 5 competency items, on-the-job training (OJT) for 30 items, and case-based learning (CBL) for 29 items. CONCLUSIONS: Some competencies should be added to the JSOH list. CBL should be introduced in training programs for specialist occupational physicians.

Abasic site-binding ligands conjugated with cyanine dyes for "off-on" fluorescence sensing of orphan nucleobases in DNA duplexes and DNA-RNA hybrids.

A series of abasic site-binding ligands conjugated with cyanine dyes have been developed for "off-on" fluorescence sensing of an orphan nucleobase in DNA duplexes and DNA-RNA hybrids.

Computed tomography assessment of pharmacological lung volume reduction induced by bronchodilators in COPD.

Pharmacological lung volume reduction in COPD is an important goal in treatment with long-acting bronchodilators because in addition to airflow limitation, lung hyperinflation considerably affects COPD symptoms. Quantitative computed tomography (CT) simultaneously provides structural information about airway dimensions, emphysematous changes, and lung volumes, some of which are difficult to be evaluated by pulmonary function. Here, we evaluated changes in CT parameters and pulmonary function in 30 patients with COPD who underwent CT scans before and one year after starting tiotropium treatment and in 12 patients with COPD who were not treated with long-acting bronchodilators. Baseline pulmonary function and CT parameters did not differ between the two groups. One-year tiotropium therapy improved physiological-indices including residual volume (RV) and ratio of RV to total lung capacity (RV/TLC) (-235 mL, p = 0.005, and -2.9%, p = 0.0001, respectively), and CT-indices including wall area percent (WA%) and inner luminal area in right upper lobe apical and lower lobe basal segmental bronchi (-1.59%, p = 0.01, 2.27 mm(2), p = 0.0005; and -1.33%, p = 0.0008, 3.42 mm(2), p < 0.0001, respectively), low attenuation volume (LAV) and total lung volume (CT-TLV) (-92 mL, p = 0.0003, and -211 mL, p = 0.002, respectively). Changes in LAV, CT-TLV, RV, and RV/TLC were significantly greater in the tiotropium, than the non-bronchodilator group. The tiotropium-induced reduction in LAV correlated with the decrease in RV (ρ = 0.45, p = 0.01). Our findings not only indicate the value of the comprehensive CT measurements in assessing the effects of bronchodilators, including pharmacological lung volume reduction, but also further understanding of the structural changes underlying physiological improvements induced by bronchodilators.

Oxidative stress induced interleukin-32 mRNA expression in human bronchial epithelial cells.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is characterized by airflow obstruction and persistent inflammation in the airways and lung parenchyma. Oxidative stress contributes to the pathogenesis of COPD. Interleukin (IL)-32 expression has been reported to increase in the lung tissue of patients with COPD. Here, we show that IFNγ upregulated IL-32 expression and that oxidative stress augmented IFNγ-induced-IL-32 expression in airway epithelial cells. We further investigated transcriptional regulation responsible for IFNγ induced IL-32 expression in human airway epithelial cells. METHODS: Human bronchial epithelial (HBE) cells were stimulated with H2O2 and IFNγ, and IL-32 expression was evaluated. The cell viability was confirmed by MTT assay. The intracellular signaling pathways regulating IL-32 expression were investigated by examining the regulatory effects of MAPK inhibitors and JAK inhibitor after treatment with H2O2 and IFNγ, and by using a ChIP assay to identify transcription factors (i.e. c-Jun, CREB) binding to the IL-32 promoter. Promoter activity assays were conducted after mutations were introduced into binding sites of c-Jun and CREB in the IL-32 promoter. IL-32 expression was also examined in HBE cells in which the expression of either c-Jun or CREB was knocked out by siRNA of indicated transcription factors. RESULTS: There were no significant differences of cell viability among groups. After stimulation with H2O2 or IFNγ for 48 hours, IL-32 expression in HBE cells was increased by IFNγ and synergistically upregulated by the addition of H2O2. The H2O2 augmented IFNγ induced IL-32 mRNA expression was suppressed by a JNK inhibitor, but not by MEK inhibitor, p38 inhibitor, and JAK inhibitor I. Significant binding of c-Jun and CREB to the IL-32 promoter was observed in the IFNγ + H2O2 stimulated HBE cells. Introducing mutations into the c-Jun/CREB binding sites in the IL-32 promoter prominently suppressed its transcriptional activity. Further, knocking down CREB expression by siRNA resulted in significant suppression of IL-32 induction by IFNγ and H2O2 in HBE cells. CONCLUSION: IL-32 expression in airway epithelium may be augmented by inflammation and oxidative stress, which may occur in COPD acute exacerbation. c-Jun and CREB are key transcriptional factors in IFNγ and H2O2 induced IL-32 expression.

Impact of COPD exacerbations on osteoporosis assessed by chest CT scan.

BACKGROUND: COPD pathology involves not only the lungs but also extrapulmonary abnormalities. Osteoporosis is one of the most important abnormalities because it may cause vertebral compression fractures and deteriorate pulmonary function. COPD patients have many risk factors for osteoporosis, such as low BMI, decreased activity, systemic inflammation, and use of corticosteroids. Some of these factors have been shown to deteriorate with COPD exacerbations. We previously demonstrated the correlation between emphysema and osteoporosis and between emphysema progression and COPD exacerbations. Thus, the hypothesis that exacerbation causes osteoporosis progression in COPD patients was investigated. METHODS: Forty-two COPD patients not on osteoporosis treatment for over 2 years were recruited. During follow-up, exacerbations had been prospectively recorded. Thoracic vertebral bone mineral density (BMD) was measured using chest CT, and the annual change in BMD was calculated. The change was compared between patients with and without a history of exacerbations. RESULTS: The decrease in thoracic vertebral BMD was greater in patients with than in those without a history of exacerbations (median ΔBMD mg/ml·year: -3.78 versus -0.30, p = 0.02). Moreover, multivariate regression analysis showed that exacerbations and baseline PaO2 were independent predictors of the BMD decrease (R² = 0.20, p = 0.007, and R² = 0.09, p = 0.03, respectively) after adjustment for baseline age, smoking status, and airflow limitation. CONCLUSIONS: This is the first longitudinal study to demonstrate that COPD exacerbations are independently associated with osteoporosis progression. Osteoporosis progression should be evaluated in COPD patients, especially in those with a history of frequent exacerbations.

A NOD2 gene polymorphism is associated with the prevalence and severity of chronic obstructive pulmonary disease in a Japanese population.

BACKGROUND AND OBJECTIVE: Genetic background is thought to be one of the risk factors for development of COPD. Recently, it has been proposed that the innate immune system is involved in the pathophysiology of COPD. We hypothesized that polymorphisms in the nucleotide-binding and oligomerization domain (NOD)1 and NOD2 genes would be associated with the pathogenesis of COPD. In addition, the associations between these single nucleotide polymorphisms (SNPs) and phenotypes of COPD were analysed. METHODS: Japanese COPD patients (n = 228) and non-COPD smokers (n = 101) were recruited from the outpatient clinic at Kyoto University Hospital, Kyoto, Japan. At entry into the study, a blood sample was taken and a pulmonary function test was performed. Genotyping was performed for 6 selected tag SNPs of NOD1 and 5 tag SNPs of NOD2. Further investigations were performed for SNP that were associated with COPD, including baseline gene expression, the relative proportions of splicing variants in whole blood, responses to ligand and enhancement of gene expression in peripheral blood neutrophils stimulated with pro-inflammatory cytokines. RESULTS: The distribution of NOD2 rs1077861 genotypes differed between Japanese COPD patients and non-COPD smokers (P = 0.036). This SNP was also associated with a lower FEV(1) % predicted (57.2 ± 1.8 for TT vs 50.8 ± 2.3 for TA/AA, P = 0.03) and DL(CO) /V(A) (2.89 ± 0.1 in TT vs 2.53 ± 0.14 in TA/AA, P = 0.036) in COPD patients. NOD2 gene expression after stimulation with 10 ng/mL of tumour necrosis factor-α for 4 h, was increased to a greater extent in TA/AA genotype than in TT genotype peripheral blood neutrophils (P = 0.015). CONCLUSIONS: The NOD2 rs1077861 SNP may influence the development and progression of COPD in Japanese subjects.

Proventricular dilatation disease associated with avian bornavirus infection in a Citron-crested Cockatoo that was born and hand-reared in Japan.

A 5-month-old female Citron-crested Cockatoo (Cacatua sulphurea citrinocristata) that was born and hand-reared in Japan died with suspected proventricular dilatation disease (PDD). Macroscopic and microscopic examinations of the bird revealed characteristic features of PDD, i.e., distention of the proventriculus and infiltration of lymphocytes and plasma cells in ganglia of various organs and in central and peripheral nerves. A linkage of this PDD case to infection with avian bornavirus (ABV) was documented by RT-PCR amplification of the virus genomes from the affected bird. Phylogenetic analysis revealed that the ABV identified in this study clustered into the genotype 2, which is one of the dominant ABV genotypes worldwide. To the best of our knowledge, this is the first report of a natural case of PDD associated with ABV infection in Japan.

Abnormal swallowing reflex and COPD exacerbations.

BACKGROUND: It is unclear whether an abnormal swallowing reflex affects COPD exacerbations. This study investigated the prevalence of abnormal swallowing reflexes and its relationship with COPD exacerbation prospectively. We also clarified its association with gastroesophageal reflux disease (GERD) and airway bacterial colonization. METHODS: Swallowing reflex and serum C-reactive protein (CRP) levels were examined in subjects with stable COPD and in control subjects. Concurrently, GERD symptoms were assessed using a self-reported questionnaire, and sputum bacterial cultures were investigated in the same subjects. Exacerbations were counted prospectively during the following 12 months. RESULTS: The study group comprised 67 subjects with COPD and 19 controls. The prevalence of abnormal swallowing reflex was significantly higher in subjects with COPD (22/67) than controls (1/19; P = .02). Among subjects with COPD, the serum CRP level, GERD symptoms, isolation of sputum bacteria, and the frequency of exacerbations were significantly increased in those with abnormal swallowing reflexes compared with controls (2.72 vs 1.04 mg/L, P = .04, for serum CRP level; 6.75 vs 4.10 points, P = .04, for GERD symptoms; 5/11 vs 3/22, P = .04, for the isolation of sputum bacteria; and 2.82 vs 1.56/y, P = .007, for the annual frequency of exacerbations). Multivariable analysis confirmed that abnormal swallowing reflex was significantly associated with frequent exacerbations (>or= 3/y; P = 0.01). CONCLUSIONS: Abnormal swallowing reflexes frequently occurred in subjects with COPD and predisposed them to exacerbations. Abnormal swallowing reflexes in COPD might be affected by the comorbidity of GERD, and cause bacterial colonization.

Cough-reflex sensitivity to inhaled capsaicin in COPD associated with increased exacerbation frequency.

BACKGROUND AND OBJECTIVE: The causes of exacerbations in COPD patients are poorly understood. This study examined the association between cough-reflex sensitivity in patients with stable COPD and the frequency of subsequent exacerbations. METHODS: The sampling frame for cases and controls for this study was patients attending a hospital outpatient clinic. cough-reflex sensitivity was evaluated using the log concentration of capsaicin causing five or more coughs (log C(5)). Subsequent COPD exacerbations were identified prospectively via symptom-based diaries over a 12-month period. RESULTS: The study group comprised 45 COPD subjects and 10 controls. Mean log C(5) was lower in the COPD group than in the control group (0.97 (95% confidence interval (CI): 0.76-1.18) versus 1.26 (95% CI: 0.81-1.71), P = 0.095). In the COPD group, log C(5) was negatively correlated with serum CRP level (r = -0.36, P = 0.02) and significantly associated with the exacerbation frequency (r = -0.38, P = 0.01). Stepwise multiple regression analysis showed that cough-reflex sensitivity was significantly associated with exacerbation frequency (r(2) = 0.15, P = 0.01). CONCLUSIONS: Hypersensitivity of the cough reflex to inhaled capsaicin might reflect airway inflammation in stable COPD patients, which predisposes to frequent exacerbations.

Increased expression of soluble form of vascular cell adhesion molecule-1 aggravates autoimmune arthritis in MRL-Fas(lpr) mice.

Vascular cell adhesion molecule-1 (VCAM-1, CD106) is important in leukocyte trafficking and its increased expression is associated with a number of chronic inflammatory diseases, including rheumatoid arthritis (RA). A soluble form of VCAM-1 (sVCAM-1) is generated by shedding of the membrane-bound molecule. The concentration of sVCAM-1 is increased in the sera of RA patients, but its pathological role has not been elucidated. The effect of sVCAM-1 relative to protection or aggravation of disease on the development of spontaneous arthritis was examined in an animal model of RA, namely MRL-Fas(lpr) mice (which display a disease resembling human RA), by generation of sVCAM-1 transgenic MRL-Fas(lpr) mice. Transgenic MRL-Fas(lpr) mice that expressed sVCAM-1 had higher incidence and increased severity of arthritis associated with higher levels of serum IgG rheumatoid factor compared with non-transgenic MRL-Fas(lpr) mice. These results suggest that sVCAM-1 plays an arthritogenic role in the development of inflammatory arthritis in MRL-Fas(lpr) mice and may present an important target for therapeutic strategy of RA.

Structural analyses on the mercuryII-mediated T-T base pair.

Recently, it was reported that T-T mismatches can specifically recognize Hg(II), and form T-Hg(II)-T pairs. In order to understand the structure and properties of the T-Hg(II)-T pair, we measured NMR spectra for a DNA duplex, d(CGCGTTGTCC) x d(GGACTTCGCG), with two successive T-T mismatches (Hg(II)-binding sites) in the middle of the duplex. We identified imino proton resonances of the T-T mismatches in mercury-free duplex, and performed titration experiments with Hg(II) by using 1-dimensional (1D) (1)H NMR spectra. From the titration spectra, disappearances of imino proton signals were observed upon the addition of Hg(II). Furthermore, we observed additional signals of transient species, most likely mono-mercurated duplexes. This is an evidence that structural transformations between Hg(II)-free and Hg(II)-bound forms are slow enough for each species to give independent signals. These data strongly suggest that the imino protons of thymine bases were substituted with Hg(II), to form T-Hg(II)-T pairs in which one Hg(II) cross-links two N3 atoms of thymines.

MercuryII-mediated formation of thymine-HgII-thymine base pairs in DNA duplexes.

The very specific binding of the HgII ion unexpectedly and significantly stabilizes naturally occurring thymine-thymine base mispairing in DNA duplexes. Following this finding, we prepared DNA duplexes containing metal-mediated base pairs at the desired sites, as well as novel double helical architectures consisting only of thymine-HgII-thymine pairs.

[An autopsy case of massive hemoptysis in systemic sarcoidosis with pulmonary granulomatous arteritis].

A 49-year-old female was admitted to our hospital because of worsening of congestive heart failure on November 2000 in a state after insertion of permanent pacemaker for complete atrioventricular block in 1986, followed by a clinical history of chronic heart failure due to dilated cardiomyopathy. After admission, her general condition had been improved, but, she had massive hemoptysis suddenly and died on February 2001. At autopsy, noncaseating granulomas were observed scattering in lungs, liver and spleen, not associated with any infectious lesions, therefore indicating systemic sarcoidosis. In lungs, granulomatous arteritis in small- and medium-sized muscular arteries associated with disputation of the media and elastic laminae were observed, suggesting the direct cause of hemoptysis. This is the extremely rare case of pulmonary arteritis with systemic sarcoidosis resulting the death from massive hemoptysis.