Elevation in serum thyroglobulin during prolonged Antarctic residence: effect of thyroxine supplement in the polar 3,5,3'-triiodothyronine syndrome

Extended Antarctic residence (AR) is associated with an increase in serum TSH, a decrease in free T(4), and an increase in T(3) production and clearance. It is not clear whether these adaptations reflect changes in clearance alone or whether intrinsic thyroidal synthetic activity also changes. Thyroglobulin (Tg) secretion is an independent marker of intrinsic thyroid activity whose kinetics are independent of those of T(3) and T(4). In this study we examined changes in Tg levels in healthy subjects before and during AR and their responses to thyroid supplementation to help determine whether alterations in thyroid activity, and not just kinetics of clearance, underlie the changes seen with the polar T(3) syndrome. In cohort 1, we compared measurements of TSH and Tg in 12 subjects before deployment and monthly for 11 months during AR. In cohort 2, we compared the same measurements in 12 subjects monthly for 11 months of AR. Subjects were randomized to receive either placebo or levothyroxine in cohort 1 for 7 months and in cohort 2 for 11 months. Tg increased over baseline during the first 4 months of AR by 17.0 +/- 4.6% and after 7 more months by 31.7 +/- 4.3% over baseline in the placebo group of both cohorts (P < 0.0002). When L-T(4) was taken, Tg returned to a value not different from baseline (4.5 +/- 3.9%). The percent changes from baseline in serum TSH and Tg during AR were highly correlated (P < 0.00003) in the placebo group for both cohorts. The rise in Tg with TSH and the reduction in Tg with L-T(4) provide evidence of target tissue response to TSH and further confirm the TSH rise as physiologically significant. The results also suggest that the adaptive changes in thyroid hormone economy with AR reflect TSH-dependent changes in thyroid synthetic activity, which may help explain a portion of the increases in T(3) production found with AR.     

Effect of clarithromycin on airway obstruction and inflammatory markers in induced sputum in cystic fibrosis: a pilot study.

To determine whether macrolide antibiotics improve pulmonary function and decrease airway inflammation in cystic fibrosis (CF), we treated 10 patients (females; aged 19-26 years, all colonized with P. aeruginosa, none with atypical Mycobacteria) with 3 weeks of placebo, followed by 6 weeks of clarithromycin (500 mg BID) in a single-blind prospective study. We also determined the safety of sputum induction and the reproducibility of assessing inflammatory markers in induced sputum. Subjects performed spirometry and underwent sputum induction (12-min inhalation of 3% saline) at 3-week intervals. We found that sputum induction was well-tolerated. We also found that the reproducibility was high for neutrophil (PMN) number (R = 0.87, P = 0.009), interleukin (IL)-8 (R = 0.73, P < 0.05, free neutrophil elastase (NE) (R = 0.82, P < 0.05), and myeloperoxidase (MPO) levels (R = 0.86, P < 0.05), but was less so for tumor necrosis factor (TNF)-alpha (R = -0.15, P = 0.7). We found no significant difference in pulmonary function after 6 weeks of treatment with clarithromycin (FEV(1) (% predicted) (mean +/- SEM), 2.2 +/- 0.9 (60 +/- 24%) vs. 2.3 +/- 1 (61 +/- 29%)), and no significant differences in any of the inflammatory indices measured. The median (and range) values before and after treatment for indices of airway inflammation in the induced sputum samples were: for PMNs, 8 (1-326) and 21 (0.2 -175) x 10(6) cells/mL sputum; for IL-8, 156 (24-656) and 202 (16-680) ng/mL; for free NE, 260 (31-1,264) and 237 (49-1,048) microg/mL; for TNF-alpha, 20 (7-128) and 35 (17-87) pg/mL; and for MPO, 169 (13-960) and 195 (14-816) microg/mL. We conclude that clarithromycin is not uniformly effective in improving airway obstruction or in decreasing airway inflammation in patients with CF.     

Consequences of long-term inflammation. Airway remodeling

Airway inflammation may not account for all the clinical manifestations of asthma. Airway remodeling, which is thought to be a result of airway chronic inflammation, may help fill this void. Remodeling is described for fatal and nonfatal asthmatics including changes in smooth muscle, collagen deposition, noncollagenous matrix, and mucus glands. This article also reviews the correlation of airway remodeling with clinical, physiologic and biologic data, experimental models of airways remodeling, and effect of therapy on airway remodeling. Throughout, it is emphasized that the concept of airway remodeling is a dynamic process that is active and potentially progressive in asthmatic patients but that may be prevented by appropriate therapy.     

T cell subsets and cellular immunity in end-stage renal disease

The T lymphocyte population was studied by immunofluorescent staining with monoclonal antibodies and laser flow cytometry in the blood of 50 patients with end-stage renal disease undergoing long-term maintenance intermittent hemodialysis. The absolute number of T cells was lower in patients receiving dialysis for more than one year (p less than 0.001), as was the absolute count of helper T cells (p less than 0.005). In patients under 30 years of age, the absolute number of helper T cells was markedly reduced, whereas the number of suppressor/cytotoxic T lymphocytes was not changed. In patients between the ages of 30 and 60 years, both helper and suppressor cells were significantly reduced. In patients over 60 years of age, only the number of helper T cells was reduced. The in vitro response of patients' lymphocytes was reduced both in the mixed lymphocyte reaction (p less than 0.01) and after phytohemagglutinin stimulation (p less than 0.001). Natural killer cytotoxicity of patients' peripheral blood mononuclear cells, however, was unaffected.     

Energy utilization associated with regular activity breaks and continuous physical activity: A randomized crossover trial

Aims

To quantify and compare energy utilization associated with prolonged sitting alone, or interrupted with regular activity breaks and/or an additional bout of continuous physical activity.

Cathepsin E Promotes Pulmonary Emphysema via Mitochondrial Fission

Emphysema is characterized by loss of lung elasticity and irreversible air space enlargement, usually in the later decades of life. The molecular mechanisms of emphysema remain poorly defined. We identified a role for a novel cathepsin, cathepsin E, in promoting emphysema by inducing mitochondrial fission. Unlike previously reported cysteine cathepsins, which have been implicated in cigarette smoke-induced lung disease, cathepsin E is a nonlysosomal intracellular aspartic protease whose function has been described only in antigen processing. We examined lung tissue sections of persons with chronic obstructive pulmonary disease, a clinical entity that includes emphysematous change. Human chronic obstructive pulmonary disease lungs had markedly increased cathepsin E protein in the lung epithelium. We generated lung epithelial-targeted transgenic cathepsin E mice and found that they develop emphysema. Overexpression of cathepsin E resulted in increased E3 ubiquitin ligase parkin, mitochondrial fission protein dynamin-related protein 1, caspase activation/apoptosis, and ultimately loss of lung parenchyma resembling emphysema. Inhibiting dynamin-related protein 1, using a small molecule inhibitor in vitro or in vivo, inhibited cathepsin E-induced apoptosis and emphysema. To the best of our knowledge, our study is the first to identify links between cathepsin E, mitochondrial fission, and caspase activation/apoptosis in the pathogenesis of pulmonary emphysema. Our data expand the current understanding of molecular mechanisms of emphysema development and may provide new therapeutic targets.Emphysema is a major subset of chronic obstructive pulmonary disease (COPD) and is defined anatomically as the destruction of the distal lung parenchyma and enlargement of the air spaces. Pulmonary emphysema is one of the main causes of morbidity and death worldwide. The most studied factor in developing COPD has long been recognized to be cigarette smoking. However, only 10% to 20% of heavy smokers develop clinically significant COPD.^1,2 Importantly, recent studies indicate that complementary pathogenic mechanisms, such as proteolytic/antiproteolytic imbalance, oxidative stress, apoptosis, or altered innate immunity, are involved in the development and progression of alveolar destruction.^3–6Cathepsins have been implicated in mediating alveolar destruction via their proteolytic activity. Cathepsins are intracellular hydrolases and include serine proteases (cathepsins A and G), aspartic proteases (cathepsins D and E), and cysteine cathepsins (cathepsins B, C, F, H, K, L, O, S, V, X, and W). Cathepsin E (Cat E), a nonlysosomal intracellular aspartic protease, is homologous to aspartic protease cathepsin D, a major proteolytic activity in the lysosomal component.⁷ Recent studies have reported that Cat E plays an important role in antigen processing via the major histocompatibility complex class II pathway, host defense against cancer cells and invading microorganisms, gastric differentiation, and development of signet-ring cell carcinoma.^8–12 However, Cat E has not been linked to lung disease.Human lung sections from persons with COPD indicated increased expression of Cat E protein in the lung epithelial cells. To investigate if increased expression of lung epithelial Cat E could lead to emphysema, we generated lung-targeted constitutive and inducible Cat E transgenic (Tg) mice. Our data indicated that inducible Cat E Tg mice developed emphysema-like lung changes as early as 1 week. We noted robust caspase 3 activation, and, when mice were administered a caspase inhibitor, emphysema was prevented. To our surprise, we did not find changes in caspases usually associated with caspase 3 activation, such as caspases 8 and 9, in Cat E Tg mice. Instead, we found significant induction of a mitochondrial fission protein, dynamin-related protein 1 (Drp1). When we inhibited Drp1 in Cat E Tg mice with Mdivi-1, a small molecule Drp1 inhibitor, we completely abolished the development of emphysema. Collectively, our data indicate that increased Cat E is a clinically relevant finding in human COPD and invoke a novel role for Cat E in mitochondrial fission-induced emphysema.     

The Predicting Response to Inhaled Corticosteroid Efficacy (PRICE) trial

BACKGROUND: Although guidelines recommend anti-inflammatory therapy for persistent asthma, recent studies suggest that 25% to 35% of patients with asthma may not improve lung function with inhaled corticosteroids. OBJECTIVE: To evaluate potential biomarkers of predicting short-term (6-week) response to inhaled corticosteroid with subsequent evaluation of responders and nonresponders to asthma control over a longer interval (16 additional weeks). METHODS: Eighty-three subjects with asthma off steroid were enrolled in this multicenter study. Biomarkers and asthma characteristics were evaluated as predictors of inhaled corticosteroid response over a 6-week trial for changes in FEV(1) and methacholine PC(20). After this, an additional 4-month trial evaluated asthma control. RESULTS: Although multiple baseline predictors had significant correlations with improvements for short-term inhaled steroid success, the only strong correlations (r >or= +/- 0.6) were albuterol reversibility (r = 0.83; P < .001), FEV(1)/forced vital capacity (r = -0.75; P < .001), and FEV(1) % predicted (r = -0.71; P < .001). Dividing the subjects in the short-term inhaled steroid trial into responders (>5% FEV(1) improvement) and nonresponders (相似文献