Symptoms of respiratory tract infection and associated care-seeking in subjects with and without obstructive lung disease; The Tromso Study: Tromso 6

ABSTRACT: BACKGROUND: Respiratory tract infections (RTIs) may be more severe in those with asthma or COPD and these patients are more frequently in need of health care. The aim of the study was to describe the frequency of RTI symptoms in a general adult population and how care-seeking is associated with the presence of obstructive lung disease. METHODS: Cross-sectional data including spirometry and self-reported chronic diseases were collected among middle-aged and elderly subjects in the Tromso population survey (Tromso 6). Self- reported RTI symptoms, consultations and antibiotic use were the main outcome variables. Possible predictors of RTI symptoms were evaluated by multivariable logistic regression. RESULTS: Of the 6414 subjects included, 798 (12.4 %) reported RTI symptoms in the previous week. RTI symptoms were reported less frequently by subjects aged 75 years or above, than by those younger than 55 years (OR 0.5). Winter season (OR 1.28), current smoking (OR 1.60), low self-rated health (OR 1.26) and moderate to severe bronchial obstruction (OR 1.51), were also statistically significant independent predictors of RTI symptoms, but these variables did not predict RTI symptoms that had started within the previous seven days. Among subjects with RTI symptoms, 5.1 % also reported a consultation with a doctor. In those with bronchial obstruction by spirometry, who did not report asthma or COPD, this frequency was 2.4 %. Antibiotic treatment was reported by 7.4 % of the participants, among whom one third had consulted a doctor. Antibiotics were taken more frequently when asthma or COPD was reported (13.7 %), but not in subjects with bronchial obstruction who did not report these diseases (7.2 %). CONCLUSIONS: RTI symptoms seldom led to consultation with a doctor and not even in subjects with obstructive lung disease. This was in particular the case in subject who did not know about their obstructive lung disease. Strategies for early diagnosis of COPD and providing health care to subjects with such disease cannot rely on their doctor visits due to respiratory symptoms.     

The effect of stimulation therapy and donepezil on cognitive function in Alzheimer¿s disease. A community based RCT with a two-by-two factorial design

ABSTRACT: BACKGROUND: Progressive neurodegeneration in Alzheimer's disease (AD) induces cognitive deterioration, and there is controversy regarding the optimal treatment strategy in early AD. Stimulation therapy, including physical exercise and cholinesterase inhibitors are both reported to postpone cognitive deterioration in separate studies. We aimed to study the effect of stimulation therapy and the additional effect of donepezil on cognitive function in early AD. METHOD: DESIGN: A two-by-two factorial trial comprising stimulation therapy for one year compared to standard care to which a randomized double-blinded placebo controlled trial with donepezil was added. SETTING: Nine rural municipalities in Northern Norway. PARTICIPANTS: 187 participants [greater than or equal to]65 years with a recent diagnosis of mild or moderate AD were included in the study of which 146 completed a one-year follow-up. INTERVENTIONS: In five municipalities the participants received stimulation therapy whereas participants in four received standard care. All participants were randomised double-blinded to donepezil or placebo and tested with three different cognitive tests four times during the one-year study period. MAIN OUTCOME: Changes in MMSE sum score. SECONDARY OUTCOME: Changes in ADAS-Cog and Clock Drawing Test. RESULTS: MMSE scores remained unchanged amongst AD participants receiving stimulation therapy and those receiving standard care. The results were consistent for ADAS-Cog and Clock Drawing Test. No time trend differences were found during one-year follow-up between groups receiving stimulation therapy versus standard care or between donepezil versus placebo. CONCLUSION: In rural AD patients non-pharmacological and pharmacological therapy did not improve outcome compared with standard care but all groups retained cognitive function during one year follow-up. Other studies are needed to confirm these results. ClinicalTrials.gov (Identifier: NCT00443014). EudraCT database (no 2004-002613-37). KEYWORDS: Alzheimer's disease. Symptomatic treatment. Postponement of cognitive deterioration.     

Restrictive pulmonary function is more prevalent in patients with ankylosing spondylitis than in matched population controls and is associated with impaired spinal mobility: a comparative study

Introduction  

Pulmonary involvement is a known manifestation in patients with ankylosing spondylitis (AS). However, previous studies have been based on small samples and the reported prevalence and associations with typical clinical features vary. The purpose of this study was to compare pulmonary function (PF) in patients with AS and population controls, and to study associations between PF and disease related variables, cardio-respiratory fitness and demographic variables in patients with AS.     

Threshold for onset of injury in Chinook salmon from exposure to impulsive pile driving sounds

The risk of effects to fishes and other aquatic life from impulsive sound produced by activities such as pile driving and seismic exploration is increasing throughout the world, particularly with the increased exploitation of oceans for energy production. At the same time, there are few data that provide insight into the effects of these sounds on fishes. The goal of this study was to provide quantitative data to define the levels of impulsive sound that could result in the onset of barotrauma to fish. A High Intensity Controlled Impedance Fluid filled wave Tube was developed that enabled laboratory simulation of high-energy impulsive sound that were characteristic of aquatic far-field, plane-wave acoustic conditions. The sounds used were based upon the impulsive sounds generated by an impact hammer striking a steel shell pile. Neutrally buoyant juvenile Chinook salmon (Oncorhynchus tshawytscha) were exposed to impulsive sounds and subsequently evaluated for barotrauma injuries. Observed injuries ranged from mild hematomas at the lowest sound exposure levels to organ hemorrhage at the highest sound exposure levels. Frequency of observed injuries were used to compute a biological response weighted index (RWI) to evaluate the physiological impact of injuries at the different exposure levels. As single strike and cumulative sound exposure levels (SEL(ss), SEL(cum) respectively) increased, RWI values increased. Based on the results, tissue damage associated with adverse physiological costs occurred when the RWI was greater than 2. In terms of sound exposure levels a RWI of 2 was achieved for 1920 strikes by 177 dB re 1 μPa(2)?s SEL(ss) yielding a SEL(cum) of 210 dB re 1 μPa(2)?s, and for 960 strikes by 180 dB re 1 μPa(2)?s SEL(ss) yielding a SEL(cum) of 210 dB re 1 μPa(2)?s. These metrics define thresholds for onset of injury in juvenile Chinook salmon.     

Acute effects of reducing vertical displacement and step frequency on running economy

This work studies the immediate effects of altering the vertical displacement of the center of mass (VD) and step frequency (SF) on the metabolic cost of level treadmill running at 16 km · h(-1) on 16 male runners. Alterations of VD, SF, and the product VD × SF was induced using a novel feedback system, which presents target and current values to the runner by visual or auditory display. Target values were set to 5 and 10% reductions from individual baseline values. The results were expressed as relative changes from baseline values. Alterations led to an increase in metabolic cost in most cases, measured as V(O2) uptake per minute and kilogram of body mass. Correlations were weak. Still, linear multiple regression revealed a positive coefficient (0.28) for the relationship between VD × SF and V(O2). Separate rank correlation tests showed negative correlation (τ = -0.19) between SF and V(O2) and positive correlation (τ = 0.16) between VD and V(O2). There is a coupling between VD and SF caused by the mechanics of running; hence, isolated reduction of either factor was hard to achieve. The linear model also showed a negative coefficient for the relationship between the height of the center of mass above the ground (CoMh) and V(O2). The effect size was small (multiple R(2) 0.07 and 0.12). Still the results indicate that reducing VD × SF by reducing the vertical displacement can have a positive effect on running economy, but a concurrent reduction in CoMh may diminish the positive effect. Midterm and long-term effects of altering the technique should also be studied.     

Recovery of barotrauma injuries in Chinook salmon, Oncorhynchus tshawytscha from exposure to pile driving sound

Juvenile Chinook salmon, Oncorhynchus tshawytscha, were exposed to simulated high intensity pile driving signals to evaluate their ability to recover from barotrauma injuries. Fish were exposed to one of two cumulative sound exposure levels for 960 pile strikes (217 or 210 dB re 1 μPa(2)·s SEL(cum); single strike sound exposure levels of 187 or 180 dB re 1 μPa(2)?s SEL(ss) respectively). This was followed by an immediate assessment of injuries, or assessment 2, 5, or 10 days post-exposure. There were no observed mortalities from the pile driving sound exposure. Fish exposed to 217 dB re 1 μPa(2)·s SEL(cum) displayed evidence of healing from injuries as post-exposure time increased. Fish exposed to 210 dB re 1 μPa(2)·s SEL(cum) sustained minimal injuries that were not significantly different from control fish at days 0, 2, and 10. The exposure to 210 dB re 1 μPa(2)·s SEL(cum) replicated the findings in a previous study that defined this level as the threshold for onset of injury. Furthermore, these data support the hypothesis that one or two Mild injuries resulting from pile driving exposure are unlikely to affect the survival of the exposed animals, at least in a laboratory environment.     

Congruent responses to weather variability in high arctic herbivores

Assessing the role of weather in the dynamics of wildlife populations is a pressing task in the face of rapid environmental change. Rodents and ruminants are abundant herbivore species in most Arctic ecosystems, many of which are experiencing particularly rapid climate change. Their different life-history characteristics, with the exception of their trophic position, suggest that they should show different responses to environmental variation. Here we show that the only mammalian herbivores on the Arctic islands of Svalbard, reindeer (Rangifer tarandus) and sibling voles (Microtus levis), exhibit strong synchrony in population parameters. This synchrony is due to rain-on-snow events that cause ground ice and demonstrates that climate impacts can be similarly integrated and expressed in species with highly contrasting life histories. The finding suggests that responses of wildlife populations to climate variability and change might be more consistent in Polar regions than elsewhere owing to the strength of the climate impact and the simplicity of the ecosystem.     

Large scale experimental effects of three levels of sheep densities on an alpine ecosystem

Plant–herbivore dynamics is a major topic in ecological research, but empirical knowledge on the ecological effects of different densities of large grazers from fully replicated experiments is rare. Previous studies have focused on grazing vs no grazing, and our understanding of the extent to which different levels of grazing alter vegetation composition, and how quickly such effects can be measured, is therefore limited. We performed a fully replicated, short‐term (four‐year) experiment using large enclosures (each ～0.3 km²) with three different sheep densities (no grazing, low grazing and high grazing, respectively) in an alpine environment with summer grazing in southern Norway to address these issues. Sheep grazing mainly affected plant species at high densities of sheep as compared to no sheep after a four‐year treatment; few effects of low sheep densities were detectable. Highly selected herbs, herbs suggested vulnerable to trampling, and woody species decreased, while most graminoids, one ruderal, one prostrate species and two bryophyte taxa increased at high sheep densities. We found contrasting responses within main functional groups highlighting that fine details of plant life histories need to be known for responses to grazing to be successfully predicted. Vascular plant cover and bare soil responded to sheep density after two years of treatment, but only for one of the species was frequency change observed at this stage. Overall, plants in low grazing plots were found to be almost unaffected. Changes in abundance were mainly found at the no grazing and high grazing treatments. Plant species that decreased at high grazing generally increased at no grazing and vice versa, suggesting a response to both cessation of grazing and enhanced grazing respectively. Our study demonstrates, beyond a simple comparison of heavily grazed and non‐grazed sites, that herbivore effects on plants are typically non‐linearly related to herbivore density, and that the speed of plant responses will depend both on the plant property examined and the grazing pressure.     

Expression and characterization of endochitinase C from Serratia marcescens BJL200 and its purification by a one-step general chitinase purification method

In this study we cloned, expressed, purified, and charaterized chitinase C1 from Serratia marcescens strain BJL200. As expected, the BJL200-ChiC1 amino acid sequence of this strain was highly similar to sequences of ChiC1 identified in two other strains of S. marcescens. BJL200-ChiC1 was overproduced in E. coli by the T7 expression system, and purified by a one-step hydrophobic interaction chromatography (HIC) with phenyl-sepharose. BJL200-ChiA and BJL200-ChiB had an approximately 30-fold higher k(cat) and 15 fold-lower K(m) than BJL200-ChiC1 for the oligomeric substrate 4-methylumbelliferyl-beta-D-N-N'-N'-triacetylchitotrioside, while BJL200-ChiC1 was 10-15 times faster than BJL200-ChiB and BJL200-ChiA in degrading the polymeric substrate CM-chitin-RBV. BJL200-ChiC1 degradation of beta-chitin resulted in a range of different chito-oligosaccharides (GlcNAc)(2) (main product), GlcNAc, (GlcNAc)(3), (GlcNAc)(4), and (GlcNAc)(5), indicating endo activity. The purification method used for BJL200-ChiC1 in this study is generally applicable to family 18 chitinases and their mutants, including inactive mutants, some of which tend to bind almost irreversibly to chitin columns. The high specificity of the interaction with the (non-chitinous) column material is mediated by aromatic residues that occur in the substrate-binding clefts and surfaces of the enzymes.     

Effects of fertilization on understorey vegetation in a Norwegian Pinus sylvestris forest

Abstract. Boreal coniferous forests have been impacted by long distance airborne pollutant deposition for most of the 20th century. Changes in forest understorey vegetation attributable to N‐deposition have been observed in southern Sweden, but not so far in southern Norway. We recorded the quantity of all species of vascular plants, bryophytes and lichens in 144 plots in a fertilization experiment in a 35‐yr old Pinus sylvestris forest in Aust Agder County, southernNorway initiated 6 yr before our study. Each plot represented a combination of three levels of nitrogen, two levels of magnesium and two levels of phosphorus addition. Effects of fertilization on species quantity were tested by Kruskal‐Wallis one‐way analysis by ranks. For vascular plants, only small and hardly significant differences were found between treatments and control. Significant negative effects of N‐fertilization were found on both mosses and lichens. To some extent, these effects could be attributed to direct effects of application of the fertilizer, but were more likely to be due to a negative feedback response to the faster growth of pine trees in fertilized stands, reducing throughfall precipitation and increasing litter fall. Significant differences between Mg‐ and P‐fertilized sites and respective controls were found for too few species to be likely to represent an overall trend.