Reliability and differentiation capability of dynamic and static kinematic measurements of rearfoot eversion in patellofemoral pain

Excessive rearfoot eversion is thought to be a risk factor for patellofemoral pain development, due to the kinesiological relationship with ascendant adaptations. Individuals with patellofemoral pain are often diagnosed through static clinical tests, in scientific studies and clinical practice. However, the adaptations seem to appear in dynamic conditions. Performing static vs. dynamic evaluations of widely used measures would add to the knowledge in this area. Thus, the aim of this study was to determine the reliability and differentiation capability of three rearfoot eversion measures: rearfoot range of motion, static clinical test and static measurement using a three-dimensional system. A total of 29 individuals with patellofemoral pain and 25 control individuals (18-30 years) participated in this study. Each subject underwent three-dimensional motion analysis during stair climbing and static clinical tests. Intraclass correlation coefficient and standard error measurements were performed to verify the reliability of the variables and receiver operating characteristic curves to show the diagnostic accuracy of each variable. In addition, analyses of variance were performed to identify differences between groups. Rearfoot range of motion demonstrated higher diagnostic accuracy (an area under the curve score of 0.72) than static measures and was able to differentiate the groups. Only the static clinical test presented poor and moderate reliability. Other variables presented high to very high values. Rearfoot range of motion was the variable that presented the best results in terms of reliability and differentiation capability. Static variables do not seem to be related to patellofemoral pain and have low accuracy values.

Association between risk behaviors and adiposity indicators in adolescents from Southern Brazil: A methodological approach

The aim of this study was to analyze the association between risk behaviors and adiposity indicators in adolescents and to discuss some methodological aspects related to this relationship. We evaluated 1,321 adolescents (55.2% female) aged 10-16 years. Relative body fat (%fat) by measurement of triceps and subscapular skinfold thickness and waist circumference (WC) were used as total and central adiposity indicators, respectively. Physical inactivity, time spent in front of the TV, the consumption of soda and/or chocolate, alcohol, and tobacco smoking were analyzed as risk behaviors. Information about the socioeconomic status (categorized into three levels) and nutritional status of the mother (overweight or normal weight) were used as adjustment factors in the analyses of prevalence ratio (PR) of the outcomes and their associated 95% confidence intervals (95% CI). The chi-square test and Poisson regression were used for statistical analyses. Low associations were found between risk behaviors and adiposity indicators. Tobacco smoking was the most positively correlated behavior with adiposity in girls (%fat: PR = 1.61; 95% CI = 1.04-2.47; WC: PR = 1.90; 95% CI = 1.17-3.08) and in adolescents whose mothers were normal weight (%fat: PR = 2.31; 95% CI = 1.33-4.03; WC: PR: 2.31; CI: 1.19-4.46). Additionally, as an important methodological issue, we highlighted the assessment of risk behaviors in adolescents as crucial to producing more robust evidence on the subject. Of the investigated behaviors, we concluded that tobacco smoking is the behavior most associated with adiposity indicators.

12 item Allodynia Symptom Checklist/Brasil: cross-cultural adaptation, internal consistency and reproducibility

Since there was no Portuguese questionnaire to evaluate cutaneous allodynia, which has been pointed out as a risk factor of migraine, we aimed to perform the cross-cultural adaptation of the 12 item Allodynia Symptom Checklist for the Brazilian population and to test its measurement properties. It consisted in six stages: translation, synthesis, back translation, revision by a specialist committee, pretest and submission the documents to the committee. In the pretest stage, the questionnaire was applied to 30 migraineurs of both sexes, who had some difficulty in understanding it. Thus, a second version was applied to 30 additional subjects, with no difficulties being reported. The mean filling out time was 3'36", and the internal consistency was 0.76. To test reproducibility, 15 other subjects filled out the questionnaire at two different times, it was classified as moderate (weighted kappa=0.58). We made available to Brazilian population an easy, quick and reliable questionnaire.

Delineation of vertebral area on the coronal plane using three-dimensional ultrasonography advanced volume contrast imaging (VCI) Omni view: intrarater reliability and agreement using standard mouse, high definition mouse, and pen-tablet

Objective: To assess the fetal lumbosacral spine by three-dimensional (3D) ultrasonography using volume contrast imaging (VCI) omni view method and compare reproducibility and agreement between three different measurement techniques: standard mouse, high definition mouse and pen-tablet. Methods: A comparative and prospective study with 40 pregnant women between 20 and 34+6 weeks was realized. 3D volume datasets of the fetal spine were acquired using a convex transabdominal transducer. Starting scan plane was the coronal section of fetal lumbosacral spine by VCI-C function. Omni view manual trace was selected and a parallel plane of fetal spine was drawn including interest region. Intraclass correlation coefficient (ICC) was used for reproducibility analysis. The relative difference between three used techniques was compared by chi-square test and Fischer test. Results: Pen-tablet showed better reliability (ICC = 0.987). In the relative proportion of differences, this was significantly higher for the pen-tablet (82.14%; p < 0.01). In paired comparison, the relative difference was significantly greater for the pen-tablet (p < 0.01). Conclusion: The pen-tablet showed to be the most reproductive and concordant method in the measurement of body vertebral area of fetal lumbosacral spine by 3D ultrasonography using the VCI.

Effect of Different Radiopacifying Agents on the Physicochemical Properties of White Portland Cement and White Mineral Trioxide Aggregate

Introduction: The aim of this study was to evaluate the pH, calcium ion release, setting time, and solubility of white mineral trioxide aggregate (WMTA) and white Portland cement (WPC) combined with the following radiopacifying agents: bismuth oxide (BO), calcium tungstate (CT), and zirconium oxide (ZO). Methods: Fifty acrylic teeth with root-end filling material were immersed in ultrapure water for measurement of pH and calcium release (atomic absorption spectrophotometry) at 3, 24, 72, and 168 hours. For evaluation of setting time, each material was analyzed according to the American Society for Testing and Materials guidelines 266/08. The solubility test was performed according to American National Standards Institute/American Dental Association specification no. 57/2000. Solubility, setting time, and pH values were compared by using analysis of variance and Tukey test, and the values of calcium release were compared by the Kruskal-Wallis and Miller tests. The significance level was set at 5%. Results: The pH and calcium release were higher at 3 and 24 hours. WPC was the material with the higher values for both properties. WMTA had the greatest solubility among all materials (P < .05). All radiopacifiers increased the setting time of WPC, and WMTA had the shortest setting time among all materials (P < .05). Conclusions: All materials released calcium ions. Except for WPC/CT at 168 hours, all materials promoted an alkaline pH. On the basis of the obtained results, ZO and CT can be considered as potential radiopacifying agents to be used in combination with Portland cement. (J Endod 2012;38:394-397)

Translation and Cross-cultural Adaptation of the Lower Extremity Functional Scale Into a Brazilian Portuguese Version and Validation on Patients With Knee Injuries

STUDY DESIGN: Clinical measurement. OBJECTIVE: To translate and culturally adapt the Lower Extremity Functional Scale (LEFS) into a Brazilian Portuguese version, and to test the construct and content validity and reliability of this version in patients with knee injuries. BACKGROUND: There is no Brazilian Portuguese version of an instrument to assess the function of the lower extremity after orthopaedic injury. METHODS: The translation of the original English version of the LEFS into a Brazilian Portuguese version was accomplished using standard guidelines and tested in 31 patients with knee injuries. Subsequently, 87 patients with a variety of knee disorders completed the Brazilian Portuguese LEES, the Medical Outcomes Study 36-Item Short-Form Health Survey, the Western Ontario and McMaster Universities Osteoarthritis Index, and the International Knee Documentation Committee Subjective Knee Evaluation Form and a visual analog scale for pain. All patients were retested within 2 days to determine reliability of these measures. Validation was assessed by determining the level of association between the Brazilian Portuguese LEFS and the other outcome measures. Reliability was documented by calculating internal consistency, test-retest reliability, and standard error of measurement. RESULTS: The Brazilian Portuguese LEES had a high level of association with the physical component of the Medical Outcomes Study 36-Item Short-Form Health Survey (r = 0.82), the Western Ontario and McMaster Universities Osteoarthritis Index (r = 0.87), the International Knee Documentation Committee Subjective Knee Evaluation Form (r = 0.82), and the pain visual analog scale (r = -0.60) (all, P<.05). The Brazilian Portuguese LEES had a low level of association with the mental component of the Medical Outcomes Study 36-Item Short-Form Health Survey (r = 0.38, P<.05). The internal consistency (Cronbach alpha = .952) and test-retest reliability (intraclass correlation coefficient = 0.957) of the Brazilian Portuguese version of the LEES were high. The standard error of measurement was low (3.6) and the agreement was considered high, demonstrated by the small differences between test and retest and the narrow limit of agreement, as observed in Bland-Altman and survival-agreement plots. CONCLUSION: The translation of the LEFS into a Brazilian Portuguese version was successful in preserving the semantic and measurement properties of the original version and was shown to be valid and reliable in a Brazilian population with knee injuries. J Ort hop Sports Phys Ther 2012;42(11):932-939, Epub 9 October 2012. doi:10.2519/jospt.2012.4101

MODULARITY, NOISE, AND NATURAL SELECTION

Most biological systems are formed by component parts that are to some degree interrelated. Groups of parts that are more associated among themselves and are relatively autonomous from others are called modules. One of the consequences of modularity is that biological systems usually present an unequal distribution of the genetic variation among traits. Estimating the covariance matrix that describes these systems is a difficult problem due to a number of factors such as poor sample sizes and measurement errors. We show that this problem will be exacerbated whenever matrix inversion is required, as in directional selection reconstruction analysis. We explore the consequences of varying degrees of modularity and signal-to-noise ratio on selection reconstruction. We then present and test the efficiency of available methods for controlling noise in matrix estimates. In our simulations, controlling matrices for noise vastly improves the reconstruction of selection gradients. We also perform an analysis of selection gradients reconstruction over a New World Monkeys skull database to illustrate the impact of noise on such analyses. Noise-controlled estimates render far more plausible interpretations that are in full agreement with previous results.

STATISTICAL TEST FOR GENOTYPE AND ENVIRONMENT CONTRIBUTION IN THE GENOTYPES x ENVIRONMENTS INTERACTION MATRIX

The objective of the present work was to propose a method for testing the contribution of each level of the factors in a genotypes x environments (GxE) interaction using multi-environment trials analyses by means of an F test. The study evaluated a data set, with twenty genotypes and thirty-four environments, in a block design with four replications. The sum of squares within rows (genotypes) and columns (environments) of the GxE matrix was simulated, generating 10000 experiments to verify the empirical distribution. Results indicate a noncentral chi-square distribution for rows and columns of the GxE interaction matrix, which was also verified by the Kolmogorov-Smirnov test and Q-Q plot. Application of the F test identified the genotypes and environments that contributed the most to the GxE interaction. In this way, geneticists can select good genotypes in their studies.

Serotonin-2C receptors in the basolateral nucleus of the amygdala mediate the anxiogenic effect of acute imipramine and fluoxetine administration

A growing body of evidence indicates that facilitation of serotonin-2C receptor (5-HT2CR)-mediated neurotransmission in the basolateral nucleus of the amygdala (BLA) is involved in anxiety generation. We investigated here whether BLA 5-HT(2C)Rs exert a differential role in the regulation of defensive behaviours related to generalized anxiety (inhibitory avoidance) and panic (escape) disorders. We also evaluated whether activation of BLA 5-HT(2C)Rs accounts for the anxiogenic effect caused by acute systemic administration of the antidepressants imipramine and fluoxetine. Male Wistar rats were tested in the elevated T-maze after intra-BLA injection of the endogenous agonist 5-HT, the 5-HT2CR agonist MK-212 or the 5-HT2CR antagonist SB-242084. This test allows the measurement of inhibitory avoidance acquisition and escape expression. We also investigated whether intra-BLA administration of SB-242084 interferes with the acute anxiogenic effect caused by imipramine and fluoxetine in the Vogel conflict test, and imipramine in the elevated T-maze. While intra-BLA administration of 5-HT and MK-212 facilitated inhibitory avoidance acquisition, suggesting an anxiogenic effect, SB-242084 had the opposite effect. None of these drugs affected escape performance. Intra-BLA injection of a sub-effective dose of SB-242084 fully blocked the anxiogenic effect caused either by the local microinjection of 5-HT or the systemic administration of imipramine and fluoxetine. Our findings indicate that 5-HT(2C)Rs in BLA are selectively involved in the regulation of defensive behaviours associated with generalized anxiety, but not panic. The results also provide the first direct evidence that activation of BLA 5-HT(2C)Rs accounts for the short-term aversive effect of antidepressants.

Anticancer drug screening from images of zebrafish embryogenesis

During the previous 10 years, global R&D expenditure in the pharmaceuticals and biotechnology sector has steadily increased, without a corresponding increase in output of new medicines. To address this situation, the biopharmaceutical industry's greatest need is to predict the failures at the earliest possible stage of the drug development process. A major key to reducing failures in drug screenings is the development and use of preclinical models that are more predictive of efficacy and safety in clinical trials. Further, relevant animal models are needed to allow a wider testing of novel hypotheses. Key to this is the developing, refining, and validating of complex animal models that directly link therapeutic targets to the phenotype of disease, allowing earlier prediction of human response to medicines and identification of safety biomarkers. Morehover, well-designed animal studies are essential to bridge the gap between test in cell cultures and people. Zebrafish is emerging, complementary to other models, as a powerful system for cancer studies and drugs discovery. We aim to investigate this research area designing a new preclinical cancer model based on the in vivo imaging of zebrafish embryogenesis. Technological advances in imaging have made it feasible to acquire nondestructive in vivo images of fluorescently labeled structures, such as cell nuclei and membranes, throughout early Zebrafishsh embryogenesis. This In vivo image-based investigation provides measurements for a large number of features at cellular level and events including nuclei movements, cells counting, and mitosis detection, thereby enabling the estimation of more significant parameters such as proliferation rate, highly relevant for investigating anticancer drug effects. In this work, we designed a standardized procedure for accessing drug activity at the cellular level in live zebrafish embryos. The procedure includes methodologies and tools that combine imaging and fully automated measurements of embryonic cell proliferation rate. We achieved proliferation rate estimation through the automatic classification and density measurement of epithelial enveloping layer and deep layer cells. Automatic embryonic cells classification provides the bases to measure the variability of relevant parameters, such as cell density, in different classes of cells and is finalized to the estimation of efficacy and selectivity of anticancer drugs. Through these methodologies we were able to evaluate and to measure in vivo the therapeutic potential and overall toxicity of Dbait and Irinotecan anticancer molecules. Results achieved on these anticancer molecules are presented and discussed; furthermore, extensive accuracy measurements are provided to investigate the robustness of the proposed procedure. Altogether, these observations indicate that zebrafish embryo can be a useful and cost-effective alternative to some mammalian models for the preclinical test of anticancer drugs and it might also provides, in the near future, opportunities to accelerate the process of drug discovery.

Development and application of a GC system for NMHC analyses of air samples from the CARIBIC aircraft project

The subject of this thesis is the development of a Gaschromatography (GC) system for non-methane hydrocarbons (NMHCs) and measurement of samples within the project CARIBIC (Civil Aircraft for the Regular Investigation of the atmosphere Based on an Instrument Container, www.caribic-atmospheric.com). Air samples collected at cruising altitude from the upper troposphere and lowermost stratosphere contain hydrocarbons at low levels (ppt range), which imposes substantial demands on detection limits. Full automation enabled to maintain constant conditions during the sample processing and analyses. Additionally, automation allows overnight operation thus saving time. A gas chromatography using flame ionization detection (FID) together with the dual column approach enables simultaneous detection with almost equal carbon atom response for all hydrocarbons except for ethyne. The first part of this thesis presents the technical descriptions of individual parts of the analytical system. Apart from the sample treatment and calibration procedures, the sample collector is described. The second part deals with analytical performance of the GC system by discussing tests that had been made. Finally, results for measurement flight are assessed in terms of quality of the data and two flights are discussed in detail. Analytical performance is characterized using detection limits for each compound, using uncertainties for each compound, using tests of calibration mixture conditioning and carbon dioxide trap to find out their influence on analyses, and finally by comparing the responses of calibrated substances during period when analyses of the flights were made. Comparison of both systems shows good agreement. However, because of insufficient capacity of the CO2 trap the signal of one column was suppressed due to breakthroughed carbon dioxide so much that its results appeared to be unreliable. Plausibility tests for the internal consistency of the given data sets are based on common patterns exhibited by tropospheric NMHCs. All tests show that samples from the first flights do not comply with the expected pattern. Additionally, detected alkene artefacts suggest potential problems with storing or contamination within all measurement flights. Two last flights # 130-133 and # 166-169 comply with the tests therefore their detailed analysis is made. Samples were analyzed in terms of their origin (troposphere vs. stratosphere, backward trajectories), their aging (NMHCs ratios) and detected plumes were compared to chemical signatures of Asian outflows. In the last chapter a future development of the presented system with focus on separation is drawn. An extensive appendix documents all important aspects of the dissertation from theoretical introduction through illustration of sample treatment to overview diagrams for the measured flights.

Measurement and modeling of cloud condensation nuclei in continental air

Atmospheric aerosol particles serving as cloud condensation nuclei (CCN) are key elements of the hydrological cycle and climate. Knowledge of the spatial and temporal distribution of CCN in the atmosphere is essential to understand and describe the effects of aerosols in meteorological models. In this study, CCN properties were measured in polluted and pristine air of different continental regions, and the results were parameterized for efficient prediction of CCN concentrations.The continuous-flow CCN counter used for size-resolved measurements of CCN efficiency spectra (activation curves) was calibrated with ammonium sulfate and sodium chloride aerosols for a wide range of water vapor supersaturations (S=0.068% to 1.27%). A comprehensive uncertainty analysis showed that the instrument calibration depends strongly on the applied particle generation techniques, Köhler model calculations, and water activity parameterizations (relative deviations in S up to 25%). Laboratory experiments and a comparison with other CCN instruments confirmed the high accuracy and precision of the calibration and measurement procedures developed and applied in this study.The mean CCN number concentrations (NCCN,S) observed in polluted mega-city air and biomass burning smoke (Beijing and Pearl River Delta, China) ranged from 1000 cm−3 at S=0.068% to 16 000 cm−3 at S=1.27%, which is about two orders of magnitude higher than in pristine air at remote continental sites (Swiss Alps, Amazonian rainforest). Effective average hygroscopicity parameters, κ, describing the influence of chemical composition on the CCN activity of aerosol particles were derived from the measurement data. They varied in the range of 0.3±0.2, were size-dependent, and could be parameterized as a function of organic and inorganic aerosol mass fraction. At low S (≤0.27%), substantial portions of externally mixed CCN-inactive particles with much lower hygroscopicity were observed in polluted air (fresh soot particles with κ≈0.01). Thus, the aerosol particle mixing state needs to be known for highly accurate predictions of NCCN,S. Nevertheless, the observed CCN number concentrations could be efficiently approximated using measured aerosol particle number size distributions and a simple κ-Köhler model with a single proxy for the effective average particle hygroscopicity. The relative deviations between observations and model predictions were on average less than 20% when a constant average value of κ=0.3 was used in conjunction with variable size distribution data. With a constant average size distribution, however, the deviations increased up to 100% and more. The measurement and model results demonstrate that the aerosol particle number and size are the major predictors for the variability of the CCN concentration in continental boundary layer air, followed by particle composition and hygroscopicity as relatively minor modulators. Depending on the required and applicable level of detail, the measurement results and parameterizations presented in this study can be directly implemented in detailed process models as well as in large-scale atmospheric and climate models for efficient description of the CCN activity of atmospheric aerosols.

Controllo ottico automatizzato di circuiti fotonici integrati: Progettazione, realizzazione e valutazione

In this report a new automated optical test for next generation of photonic integrated circuits (PICs) is provided by the test-bed design and assessment. After a briefly analysis of critical problems of actual optical tests, the main test features are defined: automation and flexibility, relaxed alignment procedure, speed up of entire test and data reliability. After studying varied solutions, the test-bed components are defined to be lens array, photo-detector array, and software controller. Each device is studied and calibrated, the spatial resolution, and reliability against interference at the photo-detector array are studied. The software is programmed in order to manage both PIC input, and photo-detector array output as well as data analysis. The test is validated by analysing state-of-art 16 ports PIC: the waveguide location, current versus power, and time-spatial power distribution are measured as well as the optical continuity of an entire path of PIC. Complexity, alignment tolerance, time of measurement are also discussed.

The sensitivity of the photostationary state of NOx and its implication for the oxidation capacity in a semi-rural and boreal forest region

Für das Vermögen der Atmosphäre sich selbst zu reinigen spielen Stickstoffmonoxid (NO) und Stickstoffdioxid (NO2) eine bedeutende Rolle. Diese Spurengase bestimmen die photochemische Produktion von Ozon (O3) und beeinflussen das Vorkommen von Hydroxyl- (OH) und Nitrat-Radikalen (NO3). Wenn tagsüber ausreichend Solarstrahlung und Ozon vorherrschen, stehen NO und NO2 in einem schnellen photochemischen Gleichgewicht, dem „Photostationären Gleichgewichtszustand“ (engl.: photostationary state). Die Summe von NO und NO2 wird deshalb als NOx zusammengefasst. Vorhergehende Studien zum photostationären Gleichgewichtszustand von NOx umfassen Messungen an unterschiedlichsten Orten, angefangen bei Städten (geprägt von starken Luftverschmutzungen), bis hin zu abgeschiedenen Regionen (geprägt von geringeren Luftverschmutzungen). Während der photochemische Kreislauf von NO und NO2 unter Bedingungen erhöhter NOx-Konzentrationen grundlegend verstanden ist, gibt es in ländlicheren und entlegenen Regionen, welche geprägt sind von niedrigeren NOx-Konzetrationen, signifikante Lücken im Verständnis der zugrundeliegenden Zyklierungsprozesse. Diese Lücken könnten durch messtechnische NO2-Interferenzen bedingt sein - insbesondere bei indirekten Nachweismethoden, welche von Artefakten beeinflusst sein können. Bei sehr niedrigen NOx-Konzentrationen und wenn messtechnische NO2-Interferenzen ausgeschlossen werden können, wird häufig geschlussfolgert, dass diese Verständnislücken mit der Existenz eines „unbekannten Oxidationsmittels“ (engl.: unknown oxidant) verknüpft ist. Im Rahmen dieser Arbeit wird der photostationäre Gleichgewichtszustand von NOx analysiert, mit dem Ziel die potenzielle Existenz bislang unbekannter Prozesse zu untersuchen. Ein Gasanalysator für die direkte Messung von atmosphärischem NO¬2 mittels laserinduzierter Fluoreszenzmesstechnik (engl. LIF – laser induced fluorescence), GANDALF, wurde neu entwickelt und während der Messkampagne PARADE 2011 erstmals für Feldmessungen eingesetzt. Die Messungen im Rahmen von PARADE wurden im Sommer 2011 in einem ländlich geprägten Gebiet in Deutschland durchgeführt. Umfangreiche NO2-Messungen unter Verwendung unterschiedlicher Messtechniken (DOAS, CLD und CRD) ermöglichten einen ausführlichen und erfolgreichen Vergleich von GANDALF mit den übrigen NO2-Messtechniken. Weitere relevante Spurengase und meteorologische Parameter wurden gemessen, um den photostationären Zustand von NOx, basierend auf den NO2-Messungen mit GANDALF in dieser Umgebung zu untersuchen. Während PARADE wurden moderate NOx Mischungsverhältnisse an der Messstelle beobachtet (10^2 - 10^4 pptv). Mischungsverhältnisse biogener flüchtige Kohlenwasserstoffverbindungen (BVOC, engl.: biogenic volatile organic compounds) aus dem umgebenden Wald (hauptsächlich Nadelwald) lagen in der Größenordnung 10^2 pptv vor. Die Charakteristiken des photostationären Gleichgewichtszustandes von NOx bei niedrigen NOx-Mischungsverhältnissen (10 - 10^3 pptv) wurde für eine weitere Messstelle in einem borealen Waldgebiet während der Messkampagne HUMPPA-COPEC 2010 untersucht. HUMPPA–COPEC–2010 wurde im Sommer 2010 in der SMEARII-Station in Hyytiälä, Süd-Finnland, durchgeführt. Die charakteristischen Eigenschaften des photostationären Gleichgewichtszustandes von NOx in den beiden Waldgebieten werden in dieser Arbeit verglichen. Des Weiteren ermöglicht der umfangreiche Datensatz - dieser beinhaltet Messungen von relevanten Spurengasen für die Radikalchemie (OH, HO2), sowie der totalen OH-Reaktivität – das aktuelle Verständnis bezüglich der NOx-Photochemie unter Verwendung von einem Boxmodell, in welches die gemessenen Daten als Randbedingungen eingehen, zu überprüfen und zu verbessern. Während NOx-Konzentrationen in HUMPPA-COPEC 2010 niedriger sind, im Vergleich zu PARADE 2011 und BVOC-Konzentrationen höher, sind die Zyklierungsprozesse von NO und NO2 in beiden Fällen grundlegend verstanden. Die Analyse des photostationären Gleichgewichtszustandes von NOx für die beiden stark unterschiedlichen Messstandorte zeigt auf, dass potenziell unbekannte Prozesse in keinem der beiden Fälle vorhanden sind. Die aktuelle Darstellung der NOx-Chemie wurde für HUMPPA-COPEC 2010 unter Verwendung des chemischen Mechanismus MIM3* simuliert. Die Ergebnisse der Simulation sind konsistent mit den Berechnungen basierend auf dem photostationären Gleichgewichtszustand von NOx.

MR imaging in Crohn's disease: correlation of MR motility measurement with histopathology in the terminal ileum

BACKGROUND: The objective of the study was to correlate MR-detectable motility alterations of the terminal ileum with biopsy-documented active and chronic changes in Crohn's disease. METHODS: This IRB approved retrospective analysis of 43 patients included magnetic resonance enterography (MRE) and terminal ileum biopsies (<2 weeks apart). Motility was measured at the terminal ileum using coronal 2D trueFISP pulse sequences (1.5T MRI,TR 83.8,TE1.89) and dedicated motility assessment software. Motility grading (hypermotility, normal, hypomotility, complete arrest) was agreed by two experienced readers. Motility was compared and correlated with histopathology using two-tailed Kruskal-Wallis test and paired Spearman Rank-Order Correlation tests. KEY RESULTS: Motility abnormalities were present in 27/43 patients: nine hypomotility and 18 complete arrest. Active disease was diagnosed on 15 biopsies: eight moderate and seven severe inflammatory activity. Chronic changes were diagnosed on 17 biopsies: 13 moderate and four severe cases. In four patients with normal motility alterations on histopathology were diagnosed. Histopathology correlated with presence (P = 0.0056 for hypomotility and P = 0.0119 for complete arrest) and grade (P < 0.0001; P = 0.0004) of motility alterations. A significant difference in the motility was observed in patients with active or chronic CD compared with patients without disease (P < 0.001; P = 0.0024). CONCLUSIONS & INFERENCES: MR-detectable motility changes of the terminal ileum correlate with histopathological findings both in active and chronic CD. Motility changes may indicate the presence pathology, but do not allow differentiation of active and chronic disease.