Comparing environmental impacts of deep-seabed and land-based mining: A defensible framework

The crises of climate change and biodiversity loss are interlinked and must be addressed jointly. A proposed solution for reducing reliance on fossil fuels, and thus mitigating climate change, is the transition from conventional combustion-engine to electric vehicles. This transition currently requires additional mineral resources, such as nickel and cobalt used in car batteries, presently obtained from land-based mines. Most options to meet this demand are associated with some biodiversity loss. One proposal is to mine the deep seabed, a vast, relatively pristine and mostly unexplored region of our planet. Few comparisons of environmental impacts of solely expanding land-based mining versus extending mining to the deep seabed for the additional resources exist and for biodiversity only qualitative. Here, we present a framework that facilitates a holistic comparison of relative ecosystem impacts by mining, using empirical data from relevant environmental metrics. This framework (Environmental Impact Wheel) includes a suite of physicochemical and biological components, rather than a few selected metrics, surrogates, or proxies. It is modified from the "recovery wheel" presented in the International Standards for the Practice of Ecological Restoration to address impacts rather than recovery. The wheel includes six attributes (physical condition, community composition, structural diversity, ecosystem function, external exchanges and absence of threats). Each has 3-5 sub attributes, in turn measured with several indicators. The framework includes five steps: (1) identifying geographic scope; (2) identifying relevant spatiotemporal scales; (3) selecting relevant indicators for each sub-attribute; (4) aggregating changes in indicators to scores; and (5) generating Environmental Impact Wheels for targeted comparisons. To move forward comparisons of land-based with deep seabed mining, thresholds of the indicators that reflect the range in severity of environmental impacts are needed. Indicators should be based on clearly articulated environmental goals, with objectives and targets that are specific, measurable, achievable, relevant, and time bound.

Prioritised research agenda for prevention and control of chronic respiratory diseases

The 2008-2013 World Health Organization (WHO) action plan on noncommunicable diseases (NCDs) includes chronic respiratory diseases as one of its four priorities. Major chronic respiratory diseases (CRDs) include asthma and rhinitis, chronic obstructive pulmonary disease, occupational lung diseases, sleep-disordered breathing, pulmonary hypertension, bronchiectiasis and pulmonary interstitial diseases. A billion people suffer from chronic respiratory diseases, the majority being in developing countries. CRDs have major adverse effects on the life and disability of patients. Effective intervention plans can prevent and control CRDs, thus reducing morbidity and mortality. A prioritised research agenda should encapsulate all of these considerations in the frame of the global fight against NCDs. This requires both CRD-targeted interventions and transverse NCD programmes which include CRDs, with emphasis on health promotion and disease prevention.

Urinary leukotriene (LT) E(4) in adolescents with dysmenorrhea: a pilot study

In the present study we measured levels of urinary leukotriene (LT) E(4) as an index of LT production during the menstrual cycle in adolescents. Mean urinary LTE(4) levels in girls with dysmenorrhea was approximately threefold higher than normal laboratory values on Day 1 of the menstrual period and approximately twofold higher than normal laboratory values on Day 5 of the menstrual period. Compared with urinary LTE(4) levels in girls with eumenorrhea, urinary LTE(4) levels in girls with dysmenorrhea were higher on Day 1 [361 +/- 123 pg/mg creatinine vs. 122 +/- 37 pg/mg creatinine, p =.1; not significant (NS)] and on Day 5 (202 +/- 26 pg/mg creatinine vs. 117 +/- 26 pg/mg creatinine, p <.05) of the menstrual period, as well as on Day 10 (159 +/- 33 pg/mg creatinine vs. 88 +/- 21 pg/mg creatinine, p =.1; NS) of the menstrual cycle. Increased urinary excretion of leukotrienes, inflammatory mediators known to cause potent vasoconstriction and uterine contractions, in girls with dysmenorrhea in this pilot study, suggests that these mediators may be involved in generating dysmenorrhea symptoms in adolescents.

Recurrent panniculitis in a man with asthma receiving treatment with leukotriene-modifying agents

Leukotriene-modifying drugs are novel agents introduced recently to treat asthma. Both 5-lipoxygenase inhibitors, such as zileuton, and leukotriene receptor antagonists, such as zafirlukast and montelukast, have proved effective in the treatment of asthma. To our knowledge, there have been no detailed reports regarding dermatologic manifestations of this class of drugs. This article describes an unusual case of erythema nodosum in a 46-year-old asthmatic man who received 2 different leukotriene modifiers.

Clinical pharmacology of leukotriene receptor antagonists and 5-lipoxygenase inhibitors

Blinded, randomized, and placebo-controlled clinical trials have established that cysteinyl leukotriene (cysLT) receptor antagonists and 5-lipoxygenase (5-LO) inhibitors are safe and effective asthma treatments. Trials of 13- to 26-wks' duration demonstrate that both the cysLT1 receptor antagonist, zafirlukast, and the 5-LO inhibitor, zileuton, improve pulmonary function and decrease daytime and nocturnal symptoms. Concomitant rescue beta-agonist inhaler use and the need for corticosteroid rescue are also reduced. Preliminary studies suggest that antileukotriene agents may also reduce indices of airway inflammation, including inflammatory cell counts and airway hyperresponsiveness. Both cysLT1 antagonists and 5-LO inhibitors offer a new approach to asthma management.

Clinical studies with agents active on the 5-lipoxygenase pathway

Leukotrienes may be considered asthmatic mediators. Compounds inhibiting their production and activity show promise in the treatment of asthma. Further clinical studies will determine the clinical usefulness of such agents.

Nitric oxide synthase in human and rat lung: immunocytochemical and histochemical localization

Nitric oxide synthase (NOS) produces nitric oxide, a mediator of potential importance in numerous physiologic and inflammatory processes in the lung. We localized constitutive NOS (c-NOS) and inducible NOS (i-NOS) within lung tissue by immunoperoxidase labeling with specific antibodies or by histochemical demonstration of the characteristic NADPH diaphorase activity of NOS. We analyzed human airway (n = 4) or parenchyma (n = 10) specimens obtained from uninvolved areas of surgical tumor resections. We also studied human fetal lung samples (n = 6) and normal or inflamed (16 h after intratracheal LPS instillation) rat lung tissue. Immunostaining with anti-c-NOS identified c-NOS antigen in rat lung nerves, endothelium, and airway epithelium. Normal or inflamed rat macrophages were not stained. Human nerve elements and large-vessel endothelium showed immunostaining with the anti-c-NOS, but no labeling of the airway or alveolar epithelium was seen. Immunostaining with anti-i-NOS showed strong labeling of rat macrophages after LPS treatment, in vivo or in vitro, while normals were negative. Human alveolar macrophages were occasionally positive for i-NOS, especially in areas of chronic inflammation, which also showed focal immunolabeling of endothelium. Uniform labeling of epithelium in large, cartilaginous airways was found with anti-i-NOS in both human bronchi and normal rat trachea samples, suggesting a constitutive role for a NOS that shares epitope(s) with or is highly homologous to the inducible, macrophage type of NOS. Histochemical staining for NADPH diaphorase activity was consistent with immunolocalization of NOS antigens.(ABSTRACT TRUNCATED AT 250 WORDS)

Human alveolar macrophages have 15-lipoxygenase and generate 15(S)-hydroxy-5,8,11-cis-13-trans-eicosatetraenoic acid and lipoxins

Eicosanoids derived from lipoxygenase (LO)-catalyzed reactions play important roles in pulmonary inflammation. Here, we examined formation of LO-derived products by human alveolar macrophages (HAM). HAM converted [1-14C]-arachidonic acid to a product carrying 14C-radiolabel that was identified as 15(S)-hydroxy-5,8,11-cis-13-trans-eicosatetraenoic acid (15-HETE) by physical methods. 15-LO mRNA was demonstrated in HAM by reverse transcription-polymerase chain reaction. Incubation of HAM for 3 d with interleukin 4(IL-4) before exposure to [1-14C]arachidonic acid led to both increased mRNA for 15-LO and a 4-fold increase in 15-HETE formation. In contrast, 5(S)-hydroxy-6-trans-8,11,14-cis-eicosatetraenoic acid generation was not significantly altered by prior exposure to IL-4. Additionally, lipoxins (LXA4 and LXB4) were detected from endogenous substrate, albeit in lower levels than leukotriene B4 (LTB4), in electrochemical detection/high performance liquid chromatography profiles from HAM incubated in the presence and absence of the chemotactic peptide (FMLP) or the calcium ionophore (A23187). Exposure of HAM to leukotriene A4 (LTA4) resulted in a 2-fold increase in LXA4 and 10-fold increase in LXB4. These results demonstrate the presence of 15-LO mRNA and enzyme activity in HAM and the production of LXA4 and LXB4 by these cells. Along with 5-LO-derived products, the biosynthesis of 15-LO-derived eicosanoids by HAM may also be relevant in modulating inflammatory responses in the lung.

The relaxant properties in guinea pig airways of S-nitrosothiols

Several cellular constituents of the lung have the capacity to synthesize a factor capable of relaxing smooth muscle which has the physicochemical properties of nitric oxide (NO). In other systems, it has been shown that NO may be stabilized in the plasma and cellular milieu by reduced thiol in the form of an S-nitrosothiol (RS-NO). These compounds have half-lives that are significantly greater than that of NO, and also retain the vasorelaxant activity of NO, which is mediated by activating guanylate cyclase and raising cyclic GMP levels. The effects of RS-NO and their potential mechanism of action on airways, however, have not been previously investigated. In this study, we have examined the smooth muscle relaxant properties of several biological and synthetic RS-NO on guinea pig trachea. Our data reveal that RS-NO are generally potent airway smooth muscle relaxants with at least a partial effect through stimulation of cyclic GMP. Relaxations were attenuated significantly by the guanylate cyclase inhibitor methylene blue (P less than .05), and RS-NO-induced increases in cyclic GMP were demonstrated (P less than .0005). The IC50 values for S-nitroso-glutathione, S-nitroso-cysteine, S-nitroso-homocysteine, S-nitroso-N-acetylcysteine, S-nitroso-penicillamine and S-nitroso-captopril were 0.99 +/- 0.09, 3.2 +/- 0.2, 2.1 +/- 0.3, 2.1 +/- 0.8, 1.8 +/- 0.8 and 20 +/- 0.7 microM (mean +/- S.E.M.), respectively. In this system isoproterenol has an IC50 of 0.016 microM and theophylline an IC50 of 74 microM, making the relaxant properties of these NO derivatives of potential pharmacological and physiological relevance.

CO2 elimination by high frequency ventilation (4 to 10 Hz) in normal subjects

We measured the rate of CO2 elimination (VCO2) by oscillatory high frequency ventilation (HFV) in 8 normal subjects and studied the effects of varying frequency, stroke volume, lung volume, and bronchodilation on VCO2. Subjects breath-held while a loudspeaker at the mouth sinusoidally forced low volumes (15 to 150 ml) of air at a high frequency (4 to 10 Hz) into the respiratory system. The CO2 eliminated from the lungs was washed out by a bias flow at the mouth. In each of 6 subjects studied, VCO2 was greater at 8 Hz than at 4 Hz (130 versus 74 ml/min; p less than 0.05) with oscillation volumes (VT) of 100 ml. At a fixed frequency of 10 Hz there was a positive linear correlation (p less than 0.01) between oscillation volume and VCO2. At a lung volume 500 ml below total lung capacity VCO2 ranged from 130 to 215 ml/min at a mean VT of 130 ml and 5 to 60 ml/min at a VT of only 10% of the estimated anatomic dead space. In 3 subjects, after inhalation of isoproterenol, there was a greater VCO2 over the entire vital capacity (p less than 0.01). We concluded that HFV can achieve values of CO2 elimination close to the estimated metabolic CO2 production in normal unintubated subjects over short periods of time.