Propagule pressure increase and phylogenetic diversity decrease community's susceptibility to invasion.

BACKGROUND: Invasions pose a large threat to native species, but the question of why some species are more invasive, and some communities more prone to invasions than others, is far from solved. Using 10 different three-species bacterial communities, we tested experimentally if the phylogenetic relationships between an invader and a resident community and the propagule pressure affect invasion probability. RESULTS: We found that greater diversity in phylogenetic distances between the members of resident community and the invader lowered invasion success, and higher propagule pressure increased invasion success whereas phylogenetic distance had no clear effect. In the later stages of invasion, phylogenetic diversity had no effect on invasion success but community identity played a stronger role. CONCLUSIONS: Taken together, our results emphasize that invasion success does not depend only on propagule pressure, but also on the properties of the community members. Our results thus indicate that invasion is a process where both invader and residing community characters act in concert.

Experimental evolution in fluctuating environments: tolerance measurements at constant temperatures incorrectly predict the ability to tolerate fluctuating temperatures.

The ability to predict the consequences of fluctuating environments on species distribution and extinction often relies on determining the tolerances of species or genotypes in different constant environments (i.e. determining tolerance curves). However, very little is known about the suitability of measurements made in constant environments to predict the level of adaptation to rapidly fluctuating environments. To explore this question, we used bacterial clones adapted to constant or fluctuating temperatures and found that measurements across a range of constant temperatures did not indicate any adaptation to fluctuating temperatures. However, adaptation to fluctuating temperatures was only apparent if growth was measured during thermal fluctuation. Thus, tolerance curves based on measurements in constant environments can be misleading in predicting the ability to tolerate fast environmental fluctuations. Such complications could lead to false estimates of the genetic merits of genotypes and extinction risks of species due to climate change-induced thermal fluctuations.

Salt chamber treatment is ineffective in treating eosinophilic inflammation in asthma.

BACKGROUND: We have shown that salt chamber treatment reduces airway hyper-responsiveness as an add-on therapy in adult asthmatics on inhaled corticosteroids. METHODS: We assessed whether this effect is due to the suppression of eosinophilic airway inflammation. Thirty-nine adult asthmatics on inhaled corticosteroids were randomized to receive active salt chamber treatment with low-salt treatment 6.6 mg/m(3) (n = 14), high-salt treatment 10.8 mg/m(3) (n = 15) or placebo 0.3 mg/m(3) (n = 10) 10 times in a 2 weeks' period in a double-blind manner. RESULTS: The level of induced sputum eosinophilic cationic protein µg/l, was 3070 before and 4651 after the low-salt treatment period, on average. In the high-salt treatment group, it was 12 192 µg/l vs 11 803 and in the placebo group 3942 vs 4144, respectively. Salt chamber treatment had no effect on sputum eosinophil or neutrophil cell numbers. CONCLUSIONS: The reduction in hyper-responsiveness observed in the previous study is probably not due to the effect on eosinophilic inflammation.

Corticosteroid therapy in intensive care unit patients with PCR-confirmed influenza A(H1N1) infection in Finland.

OBJECTIVE: To evaluate the incidence, treatment, and outcome of influenza A(H1N1) in Finnish intensive care units (ICUs) with special reference to corticosteroid treatment. METHODS: During the H1N1 outbreak in Finland between 11 October and 31 December 2009, we prospectively evaluated all consecutive ICU patients with high suspicion of or confirmed pandemic influenza A(H1N1) infection. We assessed severity of acute disease and daily organ dysfunction. Ventilatory support and other concomitant treatments were evaluated and recorded daily throughout the ICU stay. The primary outcome was hospital mortality. RESULTS: During the 3-month period altogether 132 ICU patients were tested polymerase chain reaction-positive for influenza A(H1N1). Of these patients, 78% needed non-invasive or invasive ventilatory support. The median (interquartile) length of ICU stay was 4 [2-12] days. Hospital mortality was 10 of 132 [8%, 95% confidence interval (CI) 3-12%]. Corticosteroids were administered to 72 (55%) patients, but rescue therapies except prone positioning were infrequently used. Simplified Acute Physiology Score II and Sequential Organ Failure Assessment scores in patients with and without corticosteroid treatment were 31 [24-36] and 6 [2-8] vs. 22 [5-30] and 3 [2-6], respectively. The crude hospital mortality was not different in patients with corticosteroid treatment compared to those without: 8 of 72 (11%, 95% CI 4-19%) vs. 2 of 60 (3%, 95% CI 0-8%) (P = 0.11). CONCLUSIONS: The majority of H1N1 patients in ICUs received ventilatory support. Corticosteroids were administered to more than half of the patients. Despite being more severely ill, patients given corticosteroids had comparable hospital outcome with patients not given corticosteroids.

Birch pollen honey for birch pollen allergy--a randomized controlled pilot study.

BACKGROUND: Only a few randomized controlled trials have been carried out to evaluate various complementary treatments for allergic disorders. This study assessed the effects of the preseasonal use of birch pollen honey (BPH; birch pollen added to honey) or regular honey (RH) on symptoms and medication during birch pollen season. METHODS: Forty-four patients (59% female, mean age 33 years) with physician-diagnosed birch pollen allergy consumed either BPH or RH daily in incremental amounts from November 2008 to March 2009. Seventeen patients (53% female, mean age 36 years) on their usual allergy medication served as the control group. From April to May, patients recorded daily rhinoconjunctival and other symptoms and their use of medication. Fifty patients completed the study. RESULTS: During birch pollen season in 2009, BPH patients reported a 60% lower total symptom score (p < 0.01), twice as many asymptomatic days (p < 0.01), and 70% fewer days with severe symptoms (p < 0.001), and they used 50% less antihistamines (p < 0.001) compared to the control group. The differences between the BPH and RH groups were not significant. However, the BPH patients used less antihistamines than did the RH patients (p < 0.05). CONCLUSIONS: Patients who preseasonally used BPH had significantly better control of their symptoms than did those on conventional medication only, and they had marginally better control compared to those on RH. The results should be regarded as preliminary, but they indicate that BPH could serve as a complementary therapy for birch pollen allergy.

Cow's milk allergy as a predictor of bronchial hyperresponsiveness and airway inflammation at school age.

BACKGROUND: Cow's milk allergy (CMA) has been found to be associated with an increased incidence of asthma at school age. However, prospective population-based studies of CMA and the development of airway inflammation and bronchial hyperresponsivess (BHR) are lacking. OBJECTIVE: The aims of this study was to evaluate CMA as a risk factor for BHR and airway inflammation presented later in childhood. METHODS: We followed prospectively 118 children with CMA and invited them to a clinical visit at a mean age of 8.6 years including the measurement of exhaled nitric oxide (FE(NO) ) and bronchial challenge with histamine. Ninety-four patients and 80 control subjects from the same cohort participated. RESULTS: At school age, children with a history of CMA had higher FE(NO) levels (P=0.0009) and more pronounced responsiveness to histamine (P=0.027) than their controls. Stratified analysis showed a significant difference only in IgE-positive CMA. Multinomial logistic regression analysis showed that IgE-positive CMA [odds ratio (OR) 3.51; 95% confidence intervals (CI) 1.56-7.90; P=0.002] and a history of wheeze during the first year of life (OR 2.81; 95% CI 1.16-6.84; P=0.023) were independent explanatory factors for increased FE(NO) , and IgE-positive CMA (OR 3.37; 95% CI 1.03-10.97; P=0.044) and parental smoking (OR 3.41; 95% CI 1.14-10.22; P=0.028) for increased BHR, whereas for IgE-negative CMA, no associations with FE(NO) or BHR were found. In the CMA group, those exposed to CM very early at the maternity hospital, had less BHR (P=0.002). CONCLUSIONS: Compared with their controls, children with a history of IgE-positive CMA show signs of airway inflammation, expressed as higher FE(NO) , and more pronounced bronchial responsiveness to histamine at school age. In contrast to IgE-negative CMA, IgE-positive CMA is a significant predictor of increased FE(NO) and BHR at school age. Very early exposure to CM was associated with less BHR.

Duration of clinical reactivity in cow's milk allergy is associated with levels of specific immunoglobulin G4 and immunoglobulin A antibodies to beta-lactoglobulin.

BACKGROUND: The development of tolerance in IgE-mediated allergies has been associated with lower cow's milk (CM)-specific IgE levels, increasing levels of specific IgG4 and, more contestably, IgA. OBJECTIVE: We investigated whether specific antibody responses to CM proteins differ over time between patients who recovered from cow's milk allergy (CMA) by the age of 3 years and those who developed tolerance only after the age of 8 years. METHODS: The study population comprised of 83 patients with IgE-mediated CMA. They belonged to a cohort of 6209 healthy, full-term infants followed prospectively for the emergence of CMA. Serum samples were available at diagnosis (median age 7 months), 1 year later (median 19 months) and at follow-up (median 8.5 years). Age-matched control subjects with no history of CMA (n=76) participated in the follow-up. Serum levels of IgE antibodies to CM were measured using UniCAP. Levels of IgA, IgG1 and IgG4 antibodies to beta-lactoglobulin and alpha-casein were measured using ELISA. RESULTS: Patients with persistent CMA at the age of 8 years (n=18 at diagnosis, n=16 at later time-points) had higher CM-specific IgE levels at all three time-points (P<0.001) compared with patients who became tolerant by 3 years (n=55 at diagnosis, n=54 a year later, n=40 at follow-up). They had lower serum IgA levels to beta-lactoglobulin at diagnosis (P=0.01), and lower IgG4 levels to beta-lactoglobulin (P=0.04) and alpha-casein (P=0.05) at follow-up. CONCLUSION: High CM-specific IgE levels predict the persistence of CMA. Development of tolerance is associated with elevated levels of beta-lactoglobulin-specific serum IgA at the time of diagnosis, and later increasing specific IgG4 levels to beta-lactoglobulin and alpha-casein.

Improved survival after in-hospital cardiac arrest outside critical care areas.

BACKGROUND: The in-hospital Utstein Guidelines may be used to evaluate resuscitation strategies. This study utilized the Utstein template prospectively to examine changes in outcome and outcome-related factors after resuscitation outside critical care areas over a 10-year period. METHODS: Seinäjoki Central Hospital (460 beds) is a secondary hospital in Finland with acute care activities. In 1993, the in-hospital cardiac arrest management was remodelled; an intensive care unit-based resuscitation team was formed and prospective data collection began (modified according to the Utstein Guidelines in 1997). An analysis of resuscitation attempts outside critical care areas between 1993 and 2002 was performed. To monitor developments, the patients were divided into two groups (first period, 1993-97; second period, 1998-2002). Variables independently associated with survival were identified using multiple logistic regression analysis. RESULTS: During the 10-year period, resuscitation was attempted in 183 patients. Survival to discharge was 6% during the first period and 16% during the second (P = 0.048). The corresponding figures for survival at 1 year from the event were 3% and 10% (P = 0.064). Independent predictors of survival were ventricular fibrillation or ventricular tachycardia as the initial rhythm [odds ratio (OR), 9.8; confidence interval (CI), 3.2-30.3] and cardiac arrest occurring during the second period (OR, 3.3; CI, 1.1-10.1). CONCLUSION: Prospective Utstein style data collection proved to be a valuable tool for the evaluation of management and outcome following in-hospital cardiac arrest. Increased survival was seen over 10 years outside critical care areas. Organizational changes, including cardiopulmonary resuscitation training for ward personnel and standardized resuscitation management, may have contributed to this change.

Vacancy-impurity complexes in highly Sb-doped Si grown by molecular beam epitaxy.

Positron annihilation measurements, supported by first-principles electron-structure calculations, identify vacancies and vacancy clusters decorated by 1-2 dopant impurities in highly Sb-doped Si. The concentration of vacancy defects increases with Sb doping and contributes significantly to the electrical compensation. Annealings at low temperatures of 400-500 K convert the defects to larger complexes where the open volume is neighbored by 2-3 Sb atoms. This behavior is attributed to the migration of vacancy-Sb pairs and demonstrates at atomic level the metastability of the material grown by epitaxy at low temperature.

Does the implementation of a clinical information system decrease the time intensive care nurses spend on documentation of care?

BACKGROUND: The number of intensive care units (ICU) using a clinical information system (CIS) is increasing. It is believed that replacing manual charting with an automatic documentation system allocates nurses more time for patient care. The objective of this study was to measure changes in nurses' working time utilization after the implementation of a CIS in a polyvalent ICU of a large Finnish central hospital. METHODS: An activity analysis-based comparison of the ICU nurses' working time utilization before and after the implementation of a CIS. RESULTS: After the implementation of a CIS the total time the nurses spent on documentation of nursing care increased by 3.6% (NS), 15 min per shift of 8 h per nurse. The total time they spent on patient care increased by 5.5% (P < 0.05), 21 min. Intensive care nursing activities increased by 3.7% (P < 0.05), 14 min. The length of the nurses' ICU experience had some effect on these figures. The demand for nurse labor remained constant. CONCLUSIONS: After the implementation of a CIS, an increase in the time nurses spent on documentation of care was detected, which suggests a need for further development of the system. As all the measured time changes were relatively small, any plans to reduce the ICU staff number with the aid of computers were not justified.

Ga sublattice defects in (Ga,Mn)As: thermodynamical and kinetic trends.

We have used positron annihilation spectroscopy and infrared absorption measurements to study the Ga sublattice defects in epitaxial Ga(1-x)MnxAs with Mn content varying from 0% to 5%. We show that the Ga vacancy concentration decreases and As antisite concentration increases with increasing Mn content. This is in agreement with thermodynamical considerations for the electronic part of the formation energy of the Ga sublattice point defects. However, the absolute defect concentrations imply that they are determined rather by the growth kinetics than by the thermodynamical equilibrium. The As antisite concentrations in the samples are large enough to be important for compensation and magnetic properites. In addition, the Ga vacancies are likely to be involved in the diffusion and clustering of Mn at low annealing temperatures.

Formation of thermal vacancies in highly As and P doped Si.

Using positron annihilation measurements we observed the formation of thermal vacancies in highly As and P doped Si. The vacancies start to form at temperatures as low as 650 K and are mainly undecorated at high temperatures. Upon cooling the vacancies form stable vacancy-impurity complexes such as V-As3. We determine the vacancy formation energy of E(f)=1.1(2) eV and the migration energy of E(m)=1.2(1) eV in highly doped Si. By associating these values with the vacancy-impurity pair, we get an estimate of 2.8(3) eV for the formation energy of an isolated neutral monovacancy in intrinsic Si.

Evidence of the Zn vacancy acting as the dominant acceptor in n-type ZnO.

We have used positron annihilation spectroscopy to determine the nature and the concentrations of the open volume defects in as-grown and electron irradiated (E(el)=2 MeV, fluence 6 x 10(17) cm(-2)) ZnO samples. The Zn vacancies are identified at concentrations of [V(Zn)] approximately 2 x 10(15) cm(-3) in the as-grown material and [V(Zn)] approximately 2 x 10(16) cm(-3) in the irradiated ZnO. These concentrations are in very good agreement with the total acceptor density determined by temperature dependent Hall experiments. Thus, the Zn vacancies are dominant acceptors in both as-grown and irradiated ZnO.

Prevalence of work-aggravated symptoms in clinically established asthma.

This population-based cross-sectional survey assessed the prevalence of work-aggravated asthma symptoms and the effect of the work environment on the aggravation of symptoms of established asthma. A questionnaire was sent to 2,613 persons (aged 20-65 yrs) with asthma. The analyses were restricted to the 969 respondents who were currently employed. The effect of occupational exposure on the aggravation of asthma symptoms at work was assessed according to both self-reported and expert-evaluated exposure. Approximately 21% of the respondents reported work-aggravated asthma symptoms at least weekly during the past month. The prevalence of those with work-aggravated symptoms increased by age, self-reported occupational exposure to dusts, abnormal temperatures or poor indoor air quality, physically strenuous work, and chemicals, and expert-evaluated probability of daily occupational exposure to airborne dusts, gases or fumes. Aggravation of asthma symptoms at work is common among employed adults with asthma. Both self-reported and expert-evaluated exposure to dusts, abnormal temperatures or poor indoor air quality, physically strenuous work, and chemicals explained the significant worsening of symptoms. The findings suggest a marked role of the work environment in the aggravation of symptoms of established asthma.

A dual long-term effect of breastfeeding on atopy in relation to heredity in children at 4 years of age.

BACKGROUND: The long-term effect of early feeding on atopic sensitization is still unsolved. The aim of this study was to evaluate the long-term effect of breastfeeding on atopy in groups of 4-year-old children stratified by atopic heredity. METHODS: We collected four groups of 4-year-old children from a birth cohort: two groups with differing backgrounds of atopic heredity, all exclusively breast-fed for at least 3 months; and two groups with differing atopic heredity, but all fed with cow's milk-based formula during their first weeks. The data were collected with a questionnaire, skin prick testing, and measurement of serum total and allergen-specific IgE levels. RESULTS: Breastfeeding significantly decreased the risk of allergic rhino-conjunctivitis [odds ratio (OR) 0.41, 95% confidence interval (CI) 0.18-0.95] and sensitization to furred pets, as measured by skin prick results, in children with atopic heredity, whereas in children without atopic heredity, breastfeeding was related to an increased risk of symptomatic atopy (OR 2.57, 95% CI 1.16-5.70), and high serum IgE values. A significant interaction was found between heredity and breastfeeding. CONCLUSIONS: The long-term effect of breastfeeding was dual: in children with atopic heredity, breastfeeding protected against atopy, whereas in children without atopic heredity, it increased the risk of atopy.

Vacancy defects as compensating centers in Mg-doped GaN.

We apply positron annihilation spectroscopy to identify V(N)-Mg(Ga) complexes as native defects in Mg-doped GaN. These defects dissociate in postgrowth annealings at 500-800 degrees C. We conclude that V(N)-Mg(Ga) complexes contribute to the electrical compensation of Mg as well as the activation of p-type conductivity in the annealing. The observation of V(N)-Mg(Ga) complexes confirms that vacancy defects in either the N or Ga sublattice are abundant in GaN at any position of the Fermi level during growth, as predicted previously by theoretical calculations.

Formation of vacancy-impurity complexes by kinetic processes in highly As-doped Si.

Positron annihilation experiments have been applied to verify the formation mechanism of electrically inactive vacancy-impurity clusters in highly n-type Si. We show that the migration of V-As pairs at 450 K leads to the formation of V-As2 complexes, which in turn convert to stable V-As3 defects at 700 K. These processes manifest the formation of V-As3 as the dominant vacancy-impurity cluster in highly n-type Si. They further explain the electrical deactivation and clustering of As in epitaxial or ion-implanted Si during postgrowth heat treatment at 700 K.

Cutaneous nocardiosis of the chest wall and pleura--10-year consequences of a hand actinomycetoma.

We report an unusual case of primary cutaneous nocardiosis due to Nocardia otitidiscaviarum presenting first as a mycetoma of the right hand and wrist. The patient refused treatment and was lost to follow-up until he showed up 10 years later with numerous discharging large sinuses and abscesses on the upper right quadrant of the chest wall and in the right armpit. Roentgenograms revealed pleural masses. Histology was in keeping with the diagnosis of mycetoma. Treatment with amikacin, rifampicin and co-trimaxole proved to be successful.