Messung der kombinierten Diffusionskapazität für Kohlenmonoxid und Stickstoffmonoxid bei Gesunden und Patienten mit Atemwegs- und Lungenerkrankungen

In Anbetracht der hohen Prävalenz an Atemwegs- und Lungenerkrankungen gewinnt deren Diagnostik und Therapie zunehmend an Bedeutung. Eine klinisch etablierte Methode zur Lungenfunktionsprüfung stellt die nicht-invasive Messung der Diffusionskapazität für Kohlenmonoxid (DLCO) dar, die Rückschluss auf die Gasaustauschfähigkeit der Lunge gibt. Welche Komponenten der Lunge- die Perfusion bzw. das Parenchym - bei reduzierter Diffusionskapazität konkret von pathologischen Veränderungen betroffen sind, lässt sich mittels des neuen Messverfahrens der kombinierten Diffusionskapazität für Kohlenmonoxid und Stickstoffmonoxid (DLNO) eruieren. Die vorliegende Untersuchung hat sich zum Ziel gesetzt, die Abhängigkeit des viel versprechenden Verfahrens von den Messbedingungen sowie die Aussagekraft der Messergebnisse bezüglich pathologischer Lungenveränderungen unter Hinzunahme bildgebender Verfahren zu prüfen. Bei Variation der Atemanhaltezeit von 4 s, 6 s, 8 s und 10 s differierten bei gesunden (n=10; Mittelwert +/- SD Alter 31 +/- 9 a; FEV(1) 108 +/- 8% Soll) und lungenkranken Probanden (n=10; Alter 33 +/- 9 a; FEV(1) 69 +/- 28% Soll) DLCO und DLNO signifikant (jeweils p < 0.05). Bei 6 s und 8 s waren jedoch für beide Studiengruppen vergleichbare Messwerte zu erheben, so dass eine standardisierte Messung der kombinierten Diffusionskapazität für CO und NO bei 6 s Atemanhaltezeit bzw. bei 8 s entsprechend den derzeit geltenden Empfehlungen zur Messung der Standard DLCO bei 10±2 s Atemanhaltezeit (MacIntyre et al., 2005) durch die Daten aktueller Untersuchung zu empfehlen ist. Der Vergleich der Messungen der kombinierten Diffusionskapazität sowie der Spirometrie und Ganzkörperplethysmographie von lungenkranken Probanden (n=21; Mittelwert +/- SD Alter 34 +/- 8 a; FEV(1) 59 +/- 13% Soll) mit deren hochauflösenden Thorax-Computertomograhien zeigte eine stärkere Korrelation mit DLCO und DLNO als mit den Messgrößen konventioneller Messmethoden, FEV1 als Standardgröße inbegriffen. Die CT Scores korrelierten am engsten mit DLNO (rS = -0.83; p < 0.001). Ferner ließ sich eine signifikante Beziehung zu DLCO (rS = -0.79; p < 0.001) und dem volumenspezifischen Transferkoeffizienten KNO (rS = -0.63; p < 0.01) nachweisen. Demnach erlaubt das neue Messverfahren der kombinierten Diffusionskapazität für CO und NO den Schweregrad struktureller Lungenalterationen nicht-invasiv zu quantifizieren. Um den Zusatznutzen vorgestellter Methode abschließend zu beurteilen, bedarf es weiterer prospektiver Longitudinalstudien

Environmental behavior and ecotoxicity of engineered nanoparticles to algae, plants, and fungi

Developments in nanotechnology are leading to a rapid proliferation of new materials that are likely to become a source of engineered nanoparticles (ENPs) to the environment, where their possible ecotoxicological impacts remain unknown. The surface properties of ENPs are of essential importance for their aggregation behavior, and thus for their mobility in aquatic and terrestrial systems and for their interactions with algae, plants and, fungi. Interactions of ENPs with natural organic matter have to be considered as well, as those will alter the ENPs aggregation behavior in surface waters or in soils. Cells of plants, algae, and fungi possess cell walls that constitute a primary site for interaction and a barrier for the entrance of ENPs. Mechanisms allowing ENPs to pass through cell walls and membranes are as yet poorly understood. Inside cells, ENPs might directly provoke alterations of membranes and other cell structures and molecules, as well as protective mechanisms. Indirect effects of ENPs depend on their chemical and physical properties and may include physical restraints (clogging effects), solubilization of toxic ENP compounds, or production of reactive oxygen species. Many questions regarding the bioavailability of ENPs, their uptake by algae, plants, and fungi and the toxicity mechanisms remain to be elucidate

Lung diffusing capacity for nitric oxide and carbon monoxide in relation to morphological changes as assessed by computed tomography in patients with cystic fibrosis

Background Due to large-scale destruction, changes in membrane diffusion (Dm) may occur in cystic fibrosis (CF), in correspondence to alterations observed by computed tomography (CT). Dm can be easily quantified via the diffusing capacity for nitric oxide (DLNO), as opposed to the conventional diffusing capacity for carbon monoxide (DLCO). We thus studied the relationship between DLNO as well as DLCO and a CF-specific CT score in patients with stable CF. Methods Simultaneous single-breath determinations of DLNO and DLCO were performed in 21 CF patients (mean ± SD age 35 ± 9 y, FEV1 66 ± 28%pred). Patients also underwent spirometry and bodyplethysmography. CT scans were evaluated via the Brody score and rank correlations (rS) with z-scores of functional measures were computed. Results CT scores correlated best with DLNO (rS = -0.83; p < 0.001). Scores were also related to the volume-specific NO transfer coefficient (KNO; rS = -0.63; p < 0.01) and to DLCO (rS = -0.79; p < 0.001) but not KCO. Z-scores for DLNO were significantly lower than for DLCO (p < 0.001). Correlations with spirometric (e.g., FEV1, IVC) or bodyplethysmographic (e.g., SRaw, RV/TLC) indices were weaker than for DLNO or DLCO but most of them were also significant (p < 0.05 each). Conclusion In this cross sectional study in patients with CF, DLNO and DLCO reflected CT-morphological alterations of the lung better than other measures. Thus the combined diffusing capacity for NO and CO may play a future role for the non-invasive, functional assessment of structural alterations of the lung in CF

Globally invariant metabolism but density-diversity mismatch in springtails.

Soil life supports the functioning and biodiversity of terrestrial ecosystems. Springtails (Collembola) are among the most abundant soil arthropods regulating soil fertility and flow of energy through above- and belowground food webs. However, the global distribution of springtail diversity and density, and how these relate to energy fluxes remains unknown. Here, using a global dataset representing 2470 sites, we estimate the total soil springtail biomass at 27.5 megatons carbon, which is threefold higher than wild terrestrial vertebrates, and record peak densities up to 2 million individuals per square meter in the tundra. Despite a 20-fold biomass difference between the tundra and the tropics, springtail energy use (community metabolism) remains similar across the latitudinal gradient, owing to the changes in temperature with latitude. Neither springtail density nor community metabolism is predicted by local species richness, which is high in the tropics, but comparably high in some temperate forests and even tundra. Changes in springtail activity may emerge from latitudinal gradients in temperature, predation and resource limitation in soil communities. Contrasting relationships of biomass, diversity and activity of springtail communities with temperature suggest that climate warming will alter fundamental soil biodiversity metrics in different directions, potentially restructuring terrestrial food webs and affecting soil functioning

Global fine-resolution data on springtail abundance and community structure

Springtails (Collembola) inhabit soils from the Arctic to the Antarctic and comprise an estimated ~32% of all terrestrial arthropods on Earth. Here, we present a global, spatially-explicit database on springtail communities that includes 249,912 occurrences from 44,999 samples and 2,990 sites. These data are mainly raw sample-level records at the species level collected predominantly from private archives of the authors that were quality-controlled and taxonomically-standardised. Despite covering all continents, most of the sample-level data come from the European continent (82.5% of all samples) and represent four habitats: woodlands (57.4%), grasslands (14.0%), agrosystems (13.7%) and scrublands (9.0%). We included sampling by soil layers, and across seasons and years, representing temporal and spatial within-site variation in springtail communities. We also provided data use and sharing guidelines and R code to facilitate the use of the database by other researchers. This data paper describes a static version of the database at the publication date, but the database will be further expanded to include underrepresented regions and linked with trait data.</p

C, N, pH of different aggregate fractions of a tropical savanna soil amended with organic and mineral amendments

Soil samples (0 – 5 cm) were taken from a tropical topsoil at the premises of the University of Ngaoundéré, Ngaoundéré, Cameroon. A field experiment was installed in May 2018, with t0 sampling in December 2017 and in May 2018. Four treatments were implemented: A control receiving no amendment, a mineral control receiving NPK fertiliser (20-10-10), a compost treatment receiving a compost that was prepared from Tithonia diversifolia whole plants at an annual rate of 75 t/ha, and a combined biochar and compost treatment, where compost and biochar prepared from Tithonia diversifolia were co-composted (10 % v/v biochar) and applied at an annual biochar rate of 25 t/ha. Amendments were applied in June 2018 and 2019 to a depth of approximately 10 cm and Sorghum bicolor var. S35 was sown at 0.5 m distance within the rows and 0.5 m distance between the rows approximately two weeks after the amendment. The experimental design was a Latin Square with five field repetitions of each treatment, rendering a total of 20 plots of 2 x 2 m each. Soil samples were taken from the centre of each plot with a small shovel in December of 2017, 2018, and 2019 for dry season sampling, and in May of 2018 and 2019 right before amendment and in June of 2018 and 2019 right before sowing for rainy season sampling. In 2019, a total of four sampling campaigns was carried out in May and June due to additional mesofauna sampling. Samples taken in December 2018 and in December 2019 were dry sieved on site into four different aggregate sizes: 400 – 2000 µm; 200 – 400 µm; 50 – 200 µm; < 50 µm. C and N contents were obtained by grinding air-dried soil samples using a kitchen blender for homogenisation, and then measuring C and N by dry combustion. pH was measured by suspending 5 g of air-dried soil sample in 12.5 mL of either 0.01 M CaCl2 (pHCaCl2), demineralised water (pHH2O), or 1 M KCl (pHKCl). Samples were gently shaken for 2 h, allowed for sedimentation and pH was measured using a digital pH-meter. All measurements were conducted in duplicates. Due to limited sample availability, no pH values could be obtained for aggregate fractions < 400 µm. \nThe field experiment was part of the PhD dissertation project of Laura Sophie Schnee which was carried out in partnership between the Unviersities of Bremen, Germany, and Ngaoundéré, Cameroon

Physiological, molecular and behavioural effects of copper oxide nanoparticles and copper chloride on the springtail Folsomia candida exposed via artificial test soils in a laboratory experiment

Collembola of the species Folsomia candida were exposed towards copper oxide nanoparticles or copper chloride in a laboratory test. Springtails were exposed in artificial test soils either containing kaolin or Montmorillonite K10 as clay fraction. Size of clay fraction was either 19 or 30% of total mass. The survival, reproduction, dry weight and Cu bioaccumulation were assessed in a 28-day reproduction test. Metallothionein levels, Catalase activity, moulting frequency and Cu content of the exuviae were assessed after a 6-day exposure. Results indicated toxic effetcs on physiological and molecular endpoints and a non-linear dose-response relationship for copper oxide nanoparticles when applied in montmorillonite soil, but not in kaolin soil

Reproduction test on the springtail Folsomia candida exposed via artificial test soils in a laboratory experiment

In a laboratory experiment, the soil invertebrate Folsomia candida (Collembola) was exposed to CuCl2 or copper oxide nanoparticles (CuO-NP) for 28 days. The animals were exposed via artificial test soil which varied in the size (19 or 30% of total mass) or the clay type of their clay fraction (kaolin or montmorillonite). The test substances were dissolved (CuCl2) or dispersed (CuO-NP) in pure miliQ water and stirred into the dry test soils to end up with test concentrations of 1, 3, 10 and 32 mg Cu/kg and a water content of 50% of the maximum water holding capacity of the respective soils. As a control, soil with miliQ water only was tested. At the beginning of the experiment, 5 animals at the age of 10-12 days were inserted into the test vessels containing the spiked test soil. After 28 days, the previously inserted adult animals and the juvenile animals produced within the last 28 days were extracted by floatation of the test soils with tap water. The water surface was photographed and the number of produced juveniles was counted manually with the computer programme ImageJ to assess the reproductive output of the animals and their survival rate. The adult animals were collected from the water surface and further analysed for dry mass and Cu body concentration. The endpoints survival, reproduction and dry mass per individual were referred to the average values of the negative control. All endpoints were statistically compared to the control by a linear model

Biomarker test on the springtail Folsomia candida exposed via artificial test soils in a laboratory experiment

In a laboratory experiment, the soil invertebrate Folsomia candida (Collembola) was exposed to CuCl2 or copper oxide nanoparticles (CuO-NP) for 6 days. The animals were exposed via artificial test soil which varied in the size (19 or 30% of total mass) or the clay type of their clay fraction (kaolin or montmorillonite). The test substances were dissolved (CuCl2) or dispersed (CuO-NP) in pure miliQ water and stirred into the dry test soils to end up with test concentrations of 1, 3, 10 and 32 mg Cu/kg and a water content of 50% of the maximum water holding capacity of the respective soils. As a control, soil with miliQ water only was tested. At the beginning of the experiment, around 220 animals at the age of 10-12 days were inserted into the test vessels containing the spiked test soil. After 6 days, all animals were extracted by floatation of the test soils with tap water. 50 and 150 animals were collected for catalase and metallothionein analysis, respectively. The endpoints survival, reproduction and dry mass per individual were referred to the average values of the negative control. All endpoints were statistically compared to the control by a linear model

Moulting test on the springtail Folsomia candida exposed via artificial test soils in a laboratory experiment

In a laboratory experiment, the soil invertebrate Folsomia candida (Collembola) was exposed to CuCl2 or copper oxide nanoparticles (CuO-NP) for 6 days. The animals were exposed via artificial test soil which varied in the size (19 or 30% of total mass) or the clay type of their clay fraction (kaolin or montmorillonite). The test substances were dissolved (CuCl2) or dispersed (CuO-NP) in pure miliQ water and stirred into the dry test soils to end up with test concentrations of 1, 3, 10 and 32 mg Cu/kg and a water content of 50% of the maximum water holding capacity of the respective soils. As a control, soil with miliQ water only was tested. For all soils, two tests with 5 replicates per treatment were conducted. At the beginning of the experiment, 30 animals at the age of 10-12 days were inserted into the test vessels containing the spiked test soil. After 6 days, all animals were extracted by floatation of the test soils with tap water and transferred to a Paris-plaster culture plate. After 2, 5 and 7 days, the exuviae shed by the animals were collected under a binocular and analysed for their total Cu content (not per biomass as mass of exuviae is too little to be measured) via atomic absorption spectroscopy (AAS). The number of shed exuviae per animal was calculated for each time point and statistically compared to the control by a linear mixed-effect model considering the two test runs as random factor. The Cu contents of the samples were analysed by an ordinal regression with respect to their ability to exceed the limit of detection or quantification in the AAS