The other side of the coin: systemic effects of Serendipita indica root colonization on development of sedentary plant-parasitic nematodes in Arabidopsis thaliana

MAIN CONCLUSION

Upon systemic S. indica colonization in split-root system cyst and root-knot nematodes benefit from endophyte-triggered carbon allocation and altered defense responses what significantly facilitates their development in A. thaliana. Serendipita indica is an endophytic fungus that establishes mutualistic relationships with different plants including Arabidopsis thaliana. It enhances host's growth and resistance to different abiotic and biotic stresses such as infestation by the cyst nematode Heterodera schachtii (CN). In this work, we show that S. indica also triggers similar direct reduction in development of the root-knot nematode Meloidogyne javanica (RKN) in A. thaliana. Further, to mimick the natural situation occurring frequently in soil where roots are unequally colonized by endophytes we used an in vitro split-root system with one half of A. thaliana root inoculated with S. indica and the other half infected with CN or RKN, respectively. Interestingly, in contrast to direct effects, systemic effects led to an increase in number of both nematodes. To elucidate this phenomenon, we focused on sugar metabolism and defense responses in systemic non-colonized roots of plants colonized by S. indica. We analyzed the expression of several SUSs and INVs as well as defense-related genes and measured sugar pools. The results show a significant downregulation of PDF1.2 as well as slightly increased sucrose levels in the non-colonized half of the root in three-chamber dish. Thus, we speculate that, in contrast to direct effects, both nematode species benefit from endophyte-triggered carbon allocation and altered defense responses in the systemic part of the root, which promotes their development. With this work, we highlight the complexity of this multilayered tripartite relationship and deliver new insights into sugar metabolism and plant defense responses during S. indica-nematode-plant interaction.

Wildfire and smoke association with COVID-19 cases in the Pantanal wetland, Brazil

OBJECTIVES

In 2020, Brazil experienced two concurrent public health challenges related to respiratory disease: wildfires and increased mortality due to the coronavirus (COVID-19) pandemic. Smoke from these wildfires contributed to a variety of air pollutants, including fine particulate matter (PM2.5). The present study aims to investigate the effects of environmental and socio-economic factors on COVID-19 hospitalisation in the Pantanal.

STUDY DESIGN

Ecological retrospective study.

METHODS

We applied a multilevel negative binomial model to relate monthly hospitalisation data with environmental variables.

RESULTS

We showed that monthly PM2.5 concentration levels had the greatest influence on the increase in hospitalisations by COVID-19 in the elderly (23 % increase). The Gini index, a coefficient that reflects income inequalities, also had a positive association with COVID-19 hospitalisations (18 % increase). Higher temperatures and humidity were protective factors, showing a 15 % and 14 % decrease in hospitalisations, respectively. The results of the present study suggest that high PM2.5 exposure contributed to the increase in COVID-19 hospitalisations, as did the social inequalities of each municipality.

CONCLUSIONS

The present study highlights the importance of gathering evidence supported by multiple information sources to guide decision-making and identify populations needing better public health systems.

Institutional outbreaks of influenza-like illnesses in the state of São Paulo: an analysis of the epidemiological profile during the COVID-19 pandemic

OBJECTIVES

This study aimed to spatiotemporally analyze the profile of influenza-like illness (ILI) outbreaks in the state of São Paulo, Brazil, between 2020 and 2022.

STUDY DESIGN

This was a cross-sectional retrospective study.

METHODS

Outbreaks of ILI with final diagnoses of COVID-19, influenza, or other respiratory viruses (ORVs) recorded between January 2020 and November 2022, obtained from the Notifiable Diseases Information System (SINAN NET) Outbreak module, were analyzed. Kernel density estimates and Getis-Ord Gi∗ statistics were performed to identify spatial clusters.

RESULTS

A total of 13,314 ILI outbreaks were identified, involving 130,568 cases and 2649 deaths. Of these, 104,399 (80%) were confirmed as COVID-19, 15,861 (12%) were confirmed as ORV, and 10,308 (8%) were confirmed as influenza. The year 2021 had the highest number of outbreaks and cases. Schools recorded the most outbreaks and cases, followed by long-term care facilities for older adults (LTCs). The highest average number of cases per outbreak and the highest attack rates occurred at social gatherings and prisons. Prisoners were three times more likely to contract COVID-19 during outbreaks than people in other institutions. The highest hospitalization and mortality rates for all virus types occurred in the LTC group. The occurrence and intensity of outbreaks were highly heterogeneous among the different institutions after the introduction of new SARS-CoV-2 variants in the state.

CONCLUSIONS

ILI outbreaks were not randomly distributed; they clustered in specific areas. Transmissibility varied among different institutions with different responses to the COVID-19 pandemic. These results can be used as a basis for prioritizing actions and allocating resources during future pandemics.

Multiscale architecture: Mechanics of composite cytoskeletal networks

Different types of biological cells respond differently to mechanical stresses, and these responses are mainly governed by the cytoskeleton. The main components of this biopolymer network are actin filaments, microtubules, and intermediate filaments, whose mechanical and dynamic properties are highly distinct, thus opening up a large mechanical parameter space. Aside from experiments on whole, living cells, "bottom-up" approaches, utilizing purified, reconstituted protein systems, tremendously help to shed light on the complex mechanics of cytoskeletal networks. Such experiments are relevant in at least three aspects: (i) from a fundamental point of view, cytoskeletal networks provide a perfect model system for polymer physics; (ii) in materials science and "synthetic cell" approaches, one goal is to fully understand properties of cellular materials and reconstitute them in synthetic systems; (iii) many diseases are associated with cell mechanics, so a thorough understanding of the underlying phenomena may help solving pressing biomedical questions. In this review, we discuss the work on networks consisting of one, two, or all three types of filaments, entangled or cross-linked, and consider active elements such as molecular motors and dynamically growing filaments. Interestingly, tuning the interactions among the different filament types results in emergent network properties. We discuss current experimental challenges, such as the comparability of different studies, and recent methodological advances concerning the quantification of attractive forces between filaments and their influence on network mechanics.

Serendipita indica changes host sugar and defense status in Arabidopsis thaliana: cooperation or exploitation?

Manipulation of sugar metabolism upon S. indica root colonization triggers changes in sugar pools and defense responses in A. thaliana. Serendipita indica is an endophytic fungus that establishes mutualistic relationships with many different plants including important crops as well as the model plant A. thaliana. Successful root colonization typically results in growth promotion and enhanced tolerance against various biotic and abiotic stresses. The fungus delivers phosphorus to the host and receives in exchange carbohydrates. There are hints that S. indica prefers hexoses, glucose, and fructose, products of saccharose cleavage driven by invertases (INVs) and sucrose synthases (SUSs). Carbohydrate metabolism in this interaction, however, remains still widely unexplored. Therefore, in this work, the sugar pools as well as the expression of SUSs and cytosolic INVs in plants colonized by S. indica were analyzed. Using sus1/2/3/4 and cinv1/2 mutants the importance of these genes for the induction of growth promotion and proper root colonization was demonstrated. Furthermore, the expression of several defense-related marker genes in both multiple mutants in comparison to the wild-type plants was determined. Our results show that in colonized A. thaliana plants S. indica manipulates the sugar metabolism by altering the expression of host's INV and SUS and modulates both the sugar pools and plant defense in its favor. We conclude that the interaction A. thaliana-S. indica is a balancing act between cooperation and exploitation, in which sugar metabolism plays a crucial role. Small changes in this mechanism can lead to severe disruption resulting in the lack of growth promotion or altered colonization rate.

Opportunistic osteoporosis screening in multi-detector CT images via local classification of textures

Our study proposed an automatic pipeline for opportunistic osteoporosis screening using 3D texture features and regional vBMD using multi-detector CT images. A combination of different local and global texture features outperformed the global vBMD and showed high discriminative power to identify patients with vertebral fractures.

INTRODUCTION

Many patients at risk for osteoporosis undergo computed tomography (CT) scans, usable for opportunistic (non-dedicated) screening. We compared the performance of global volumetric bone mineral density (vBMD) with a random forest classifier based on regional vBMD and 3D texture features to separate patients with and without osteoporotic fractures.

METHODS

In total, 154 patients (mean age 64 ± 8.5, male; n = 103) were included in this retrospective single-center analysis, who underwent contrast-enhanced CT for other reasons than osteoporosis screening. Patients were dichotomized regarding prevalent vertebral osteoporotic fractures (noFX, n = 101; FX, n = 53). Vertebral bodies were automatically segmented, and trabecular vBMD was calculated with a dedicated phantom. For 3D texture analysis, we extracted gray-level co-occurrence matrix Haralick features (HAR), histogram of gradients (HoG), local binary patterns (LBP), and wavelets (WL). Fractured vertebrae were excluded for texture-feature and vBMD data extraction. The performance to identify patients with prevalent osteoporotic vertebral fractures was evaluated in a fourfold cross-validation.

RESULTS

The random forest classifier showed a high discriminatory power (AUC = 0.88). Parameters of all vertebral levels significantly contributed to this classification. Importantly, the AUC of the proposed algorithm was significantly higher than that of volumetric global BMD alone (AUC = 0.64).

CONCLUSION

The presented classifier combining 3D texture features and regional vBMD including the complete thoracolumbar spine showed high discriminatory power to identify patients with vertebral fractures and had a better diagnostic performance than vBMD alone.

Evolution and functional characterization of pectate lyase PEL12, a member of a highly expanded Clonostachys rosea polysaccharide lyase 1 family

Background

Pectin is one of the major and most complex plant cell wall components that needs to be overcome by microorganisms as part of their strategies for plant invasion or nutrition. Microbial pectinolytic enzymes therefore play a significant role for plant-associated microorganisms and for the decomposition and recycling of plant organic matter. Recently, comparative studies revealed significant gene copy number expansion of the polysaccharide lyase 1 (PL1) pectin/pectate lyase gene family in the Clonostachys rosea genome, while only low numbers were found in Trichoderma species. Both of these fungal genera are widely known for their ability to parasitize and kill other fungi (mycoparasitism) and certain species are thus used for biocontrol of plant pathogenic fungi.

Results

In order to understand the role of the high number of pectin degrading enzymes in Clonostachys, we studied diversity and evolution of the PL1 gene family in C. rosea compared with other Sordariomycetes with varying nutritional life styles. Out of 17 members of C. rosea PL1, we could only detect two to be secreted at acidic pH. One of them, the pectate lyase pel12 gene was found to be strongly induced by pectin and, to a lower degree, by polygalacturonic acid. Heterologous expression of the PEL12 in a PL1-free background of T. reesei revealed direct enzymatic involvement of this protein in utilization of pectin at pH 5 without a requirement for Ca²⁺. The mutants showed increased utilization of pectin compounds, but did not increase biocontrol ability in detached leaf assay against the plant pathogen Botrytis cinerea compared to the wild type.

Conclusions

In this study, we aimed to gain insight into diversity and evolution of the PL1 gene family in C. rosea and other Sordariomycete species in relation to their nutritional modes. We show that C. rosea PL1 expansion does not correlate with its mycoparasitic nutritional mode and resembles those of strong plant pathogenic fungi. We further investigated regulation, specificity and function of the C. rosea PEL12 and show that this enzyme is directly involved in degradation of pectin and pectin-related compounds, but not in C. rosea biocontrol.

Electronic supplementary material

The online version of this article (10.1186/s12866-018-1310-9) contains supplementary material, which is available to authorized users.

High-Frequency Oscillatory Ventilation and Nitric Oxide: Alternative or Complementary to ECMO

One hundred and seventy-seven term or near-term neonates were referred to an ECMO center for severe PPHN-associated diseases. In 2 time periods from 1987 to 1991 and from 1992 to April 1995 alternative treatment modes were tried in an attempt to obviate ECMO. During the first time period patients underwent trial high-frequency oscillatory ventilation before ECMO. In the second time period patients first received inhaled NO followed by HFOV in a non-responders. If this also failed HFOV was combined with I NO. In both time periods about 40% of the patients were spared ECMO treatment by these alternative treatment modalities. I NO only benefited 15% of the ECMO candidates who apparently had fared just as well on HFOV alone in the preceding time period. While patients who were improved by I NO were spared HFOV with its potential severe complications, i.e. air leaks and cardiocirculatory instability, more extended long-term studies will have to show which of these 2 treatment modalities (INO or HFOV) should be given first priority in an attempt to avoid ECMO in neonates with severe respiratory failure.

Prognosis and Outcome of Neonates Treated Either with Veno-Arterial (VA) or Veno-Venous (VV) ECMO

A comparison was done between neonates requiring veno-arterial (VA) ECMO (too small jugular vein, inability to insert a 12 Fr double lumen catheter or cardio-circulatory instability) and neonates treated with veno-venous (VV) ECMO in the same period of time. From 1991-1995 ECMO was done in 48 neonates after failure of maximum conventional treatments, NO-inhalation and HFOV. 30/48 babies were treated with VV-ECMO, with a switch to VA-ECMO later on in 3 of them. In 18 infants VA-ECMO was installed primarily. Differences between the VA- and VV-ECMO group were: the 01 was higher in the VV-treated babies (62±20 vs. 48±13, p < 0.03), as were birth weight (3385±570 vs. 2963±653 g, p< 0.04), gestational age (39.7 ± 1.6 vs. 37.9 ± 2.7 weeks, p< 0.01) and MAP (18.7 ± 2.2 vs. 17.1 ± 2.4 cm H2O, p< 0.05). Severe ICH's occurred more frequently in the VA-treated babies (29 vs. 7%, p< 0.05), the rate of other complications was equal. The mortality rates were 43% (VA) and 15% (VV), p< 0.05. About one third of neonatal ECMO candidates will be treated with VA-ECMO, even if the VV-ECMO technique is available. Need for VA-ECMO implies - due to a higher number of preterm babies and a greater severity of illness before ECMO - a higher incidence of ICH's and a higher mortality rate.

Die Leitlinie „Akutes Skrotum im Kindes und Jugendalter“ kurzgefasst

The guideline "The Acute Scrotum in Children and Adolescents" has been developed by representatives of the German Society of Pediatric Surgery, the German Society for Urology, and the German Society for Pediatric Radiology confirmed by the German Society for Pediatric and Adolescent Medicine. It went online in December 2015. The core statements of the guideline will be summarised. All relevant references can be found in the original [1]. Conclusions agreed within the team of authors are marked (#).

A Versatile Family 3 Glycoside Hydrolase from Bifidobacterium adolescentis Hydrolyzes β-Glucosides of the Fusarium Mycotoxins Deoxynivalenol, Nivalenol, and HT-2 Toxin in Cereal Matrices

Glycosylation plays a central role in plant defense against xenobiotics, including mycotoxins. Glucoconjugates of Fusarium toxins, such as deoxynivalenol-3-O-β-d-glucoside (DON-3G), often cooccur with their parental toxins in cereal-based food and feed. To date, only limited information exists on the occurrence of glucosylated mycotoxins and their toxicological relevance. Due to a lack of analytical standards and the requirement of high-end analytical instrumentation for their direct determination, hydrolytic cleavage of β-glucosides followed by analysis of the released parental toxins has been proposed as an indirect determination approach. This study compares the abilities of several fungal and recombinant bacterial β-glucosidases to hydrolyze the model analyte DON-3G. Furthermore, substrate specificities of two fungal and two bacterial (Lactobacillus brevis and Bifidobacterium adolescentis) glycoside hydrolase family 3 β-glucosidases were evaluated on a broader range of substrates. The purified recombinant enzyme from B. adolescentis (BaBgl) displayed high flexibility in substrate specificity and exerted the highest hydrolytic activity toward 3-O-β-d-glucosides of the trichothecenes deoxynivalenol (DON), nivalenol, and HT-2 toxin. A Km of 5.4 mM and a Vmax of 16 μmol min(-1) mg(-1) were determined with DON-3G. Due to low product inhibition (DON and glucose) and sufficient activity in several extracts of cereal matrices, this enzyme has the potential to be used for indirect analyses of trichothecene-β-glucosides in cereal samples.

Comparison of homo- and heterofermentative lactic acid bacteria for implementation of fermented wheat bran in bread

Despite its potential health benefits, the integration of wheat bran into the food sector is difficult due to several adverse technological and sensory properties such as bitterness and grittiness. Sourdough fermentation is a promising strategy to improve the sensory quality of bran without inducing severe changes to the bran matrix. Therefore, identification of species/strains with potential for industrial sourdough fermentations is important. We compared the effects of different representatives of species of lactic acid bacteria (LAB) on wheat bran. Lactobacillus plantarum, Lactobacillus pentosus, Lactobacillus brevis, Lactobacillus sanfranciscensis and Fructobacillus fructosus produced highly individual fermentation patterns as judged from carbohydrate consumption and organic acid production. Interestingly, fructose was released during all bran fermentations and possibly influenced the fermentation profiles of obligately heterofermentative species to varying degrees. Except for the reduction of ferulic acid by L. plantarum and L. pentosus, analyses of phenolic compounds and alkylresorcinols suggested that only minor changes thereof were induced by the LAB metabolism. Sensory analysis of breads baked with fermented bran did not reveal significant differences regarding perceived bitterness and aftertaste. We conclude that in addition to more traditionally used sourdough species such as L. sanfranciscensis and L. brevis, also facultatively heterofermentative species such as L. plantarum and L. pentosus possess potential for industrial wheat bran fermentations and should be considered in further investigations.

ZNF804A genetic variation (rs1344706) affects brain grey but not white matter in schizophrenia and healthy subjects

BACKGROUND

Genetic variation in the gene encoding ZNF804A, a risk gene for schizophrenia, has been shown to affect brain functional endophenotypes of the disorder, while studies of white matter structure have been inconclusive.

METHOD

We analysed effects of ZNF804A single nucleotide polymorphism rs1344706 on grey and white matter using voxel-based morphometry (VBM) in high-resolution T1-weighted magnetic resonance imaging scans of 62 schizophrenia patients and 54 matched healthy controls.

RESULTS

We found a significant (p < 0.05, family-wise error corrected for multiple comparisons) interaction effect of diagnostic group x genotype for local grey matter in the left orbitofrontal and right and left lateral temporal cortices, where patients and controls showed diverging effects of genotype. Analysing the groups separately (at p < 0.001, uncorrected), variation in rs1344706 showed effects on brain structure within the schizophrenia patients in several areas including the left and right inferior temporal, right supramarginal/superior temporal, right and left inferior frontal, left frontopolar, right and left dorsolateral/ventrolateral prefrontal cortices, and the right thalamus, as well as effects within the healthy controls in left lateral temporal, right anterior insula and left orbitofrontal cortical areas. We did not find effects of genotype of regional white matter in either of the two cohorts.

CONCLUSIONS

Our findings demonstrate effects of ZNF804A genetic variation on brain structure, with diverging regional effects in schizophrenia patients and healthy controls in frontal and temporal brain areas. These effects, however, might be dependent on the impact of other (genetic or non-genetic) disease factors.

The progestin levonorgestrel disrupts gonadotropin expression and sex steroid levels in pubertal roach (Rutilus rutilus)

The aim of the present study was to investigate the effects of the synthetic progestin levonorgestrel (LNG) on the reproductive endocrine system of a teleost fish, the roach (Rutilus rutilus). Pubertal roach were exposed for 28 days in a flow-through system to four concentrations of LNG (3, 31, 312, and 3124 ng/l). Both males and females treated with 3124 ng/l LNG exhibited the upregulated levels of vitellogenin and oestrogen receptor 1 mRNA in the liver. At the same concentration, LNG caused a significant upregulation of the mRNA expression of the gene encoding luteinising hormone β-subunit (lhβ) and the suppression of the mRNA expression of the gene encoding follicle-stimulating hormone β-subunit (fshβ) in the pituitary of both male and female roach. A lower LNG concentration (312 ng/l) suppressed mRNA expression of fshβ in males only. Females treated with 3124 ng/l LNG exhibited significantly lower plasma 11-ketotestosterone (11-KT) and oestradiol (E2) concentrations, whereas their testosterone (T) level was higher compared with the control. Females exposed to 312 ng/l LNG presented significantly lower plasma E2 concentrations. Males exposed to ≥31 ng/l LNG exhibited significantly reduced 11-KT levels. As determined through a histological analysis, the ovaries of females were not affected by LNG exposure, whereas the testes of males exposed to 31 and 312 ng/l LNG exhibited a significantly higher percentage of spermatogonia B compared with the control. The results of the present study demonstrate that LNG disrupts the reproductive system of pubertal roach by affecting the pituitary gonadotropin expression and the sex steroid levels. This disruption was determined to occur in males after exposure to an environmentally relevant concentration (31 ng/l). Moreover, the highest tested concentration of LNG (3124 ng/l) exerted an oestrogenic effect on fish of both sexes.

Altered sucrose synthase and invertase expression affects the local and systemic sugar metabolism of nematode-infected Arabidopsis thaliana plants

Sedentary endoparasitic nematodes of plants induce highly specific feeding cells in the root central cylinder. From these, the obligate parasites withdraw all required nutrients. The feeding cells were described as sink tissues in the plant's circulation system that are supplied with phloem-derived solutes such as sugars. Currently, there are several publications describing mechanisms of sugar import into the feeding cells. However, sugar processing has not been studied so far. Thus, in the present work, the roles of the sucrose-cleaving enzymes sucrose synthases (SUS) and invertases (INV) in the development of Heterodera schachtii were studied. Gene expression analyses indicate that both enzymes are regulated transcriptionally. Nematode development was enhanced on multiple INV and SUS mutants. Syncytia of these mutants were characterized by altered enzyme activity and changing sugar pool sizes. Further, the analyses revealed systemically affected sugar levels and enzyme activities in the shoots of the tested mutants, suggesting changes in the source-sink relationship. Finally, the development of the root-knot nematode Meloidogyne javanica was studied in different INV and SUS mutants and wild-type Arabidopsis plants. Similar effects on the development of both sedentary endoparasitic nematode species (root-knot and cyst nematode) were observed, suggesting a more general role of sucrose-degrading enzymes during plant-nematode interactions.

Migration of Ag- and TiO2-(Nano)particles from textiles into artificial sweat under physical stress: experiments and exposure modeling

Engineered nanoparticles (ENP) are increasingly used to functionalize textiles taking advantage, e.g., of the antimicrobial activity of silver (Ag)-ENP or the UV-absorption of titania (TiO2)-ENP. Mobilization and migration of ENPs from the textile into human sweat can result in dermal exposure to these nanoobjects and their aggregates and agglomerates (NOAA). In this study we assessed exposure to NOAA migrating from commercially available textiles to artificial sweat by an experimental setup that simulates wear-and-tear during physical activity. By combining physical stress with incubation in alkaline and acidic artificial sweat solutions we experimentally realized a worst case scenario for wearing functionalized textiles during sports activities. This experimental approach is not limited to NOAA, but can be used for any other textile additive. Out of four investigated textiles, one T-shirt and one pair of trousers with claimed antimicrobial properties were found to release Ag <450 nm in detectable amounts (23-74 μg/g/L). Textiles containing TiO2 for UV protection did not release significant amounts of TiO2 <450 nm, but the antimicrobial T-shirt released both TiO2 and Ag <450 nm. The silver was present in dissolved and particulate form, whereas TiO2 was mainly found as particulate. On the basis of our experimental results we calculated external dermal exposure to Ag and TiO2 for male and female adults per use. For silver, maximal amounts of 17.1 and 8.2 μg/kg body weight were calculated for total and particulate Ag <450 nm, respectively. For TiO2, the exposure levels amount to maximal 11.6 μg/kg body weight for total (mainly particulate) TiO2. In comparison with other human exposure pathways, dermal exposure to NOAA from textiles can be considered comparably minor for TiO2-NOAA, but not for Ag-NOAA.

Characterization of silver release from commercially available functional (nano)textiles

Silver, both in the nano as well as in other forms, is used in many applications including antimicrobial textiles. Washing of such textiles has already been identified as an important process that results in the release of silver into wastewater. This study thus investigated the release of silver from eight different commercially available silver-textiles during a washing and rinsing cycle. The silver released was size-fractionated and characterized using electron microscopy. In addition, the antimicrobial functionality of the textiles was tested before and after washing. Three of the textiles contained nanosized silver (labeled or confirmed by manufacturers' information), another used a metallic silver wire and four contained silver in undeclared form. The initial silver content of the textiles was between 1.5 and 2925mg Ag/kg. Only four of the investigated textiles leached detectable amounts of silver, of which 34-80% was in the form of particles larger than 450nm. Microscopic analysis of the particles released in the washing solutions identified Ti/Si-AgCl nanocomposites, AgCl nanoparticles, large AgCl particles, nanosilver sulfide and metallic nano-Ag, respectively. The nanoparticles were mainly found in highly agglomerated form. The identified nanotextiles showed the highest antimicrobial activity, whereas some of the other textiles, e.g. the one with a silver wire and the one with the lowest silver content, did not reduce the growth of bacteria at all. The results show that different silver textiles release different forms of silver during washing and that among the textiles investigated AgCl was the most frequently observed chemical form in the washwater.

Release of titanium dioxide from textiles during washing

Nano-TiO(2) has the highest production of all nanomaterials, and pigment-TiO(2) is a commodity used on the million tons/year scale. Information on the release of TiO(2) from consumer products is therefore an important part of analyzing the potential environmental exposure to TiO(2). For this study, we investigated the release of TiO(2) from six different functional textiles during washing. TiO(2) is used in textiles because of its UV-absorbing properties and as pigment. Analysis of fiber cross sections showed that the TiO(2) was contained in the fiber matrix. The sun-protection textiles had Ultraviolet Protection Factors that were between 58 and 6100 after washing and therefore above the labeled factor of 50+. Five of the textiles (sun-protection clothes) released low amounts of Ti (0.01 to 0.06 wt % of total Ti) in one wash cycle. One textile (with antimicrobial functionality) released much higher amounts of Ti (5 mg/L, corresponding to 3.4 wt % of total Ti in one wash cycle). Size fractionation showed that about equal amounts were released as particles below and above 0.45 μm. After 10 washings, only in two textiles significantly lower Ti contents were measured. Electron microscopy showed that the TiO(2) particles released into washing solution had a roundish appearance with primary particle sizes between 60 and 350 nm that formed small aggregates with up to 20 particles. The results indicate that functional textiles release some TiO(2) particles, but that the amounts are relatively low and mostly not in the nanoparticulate range.

SU-D-BRB-01: 4D-CT Lung Ventilation Images Vary with 4D-CT Sorting Techniques

PURPOSE

4D-CT ventilation imaging is a novel promising technique for lung functional imaging and has potential as a biomarker for radiation pneumonitis, but has not been validated in human subjects. The current 4D- CT technique with phase-based sorting results in artifacts at an alarmingly high frequency (90%), which may introduce variations into ventilation calculations. The purpose of this study was to quantify the variability of 4D- CT ventilation imaging to 4D-CT sorting techniques.

METHODS

Two 4D-CT images were generated from the same data set by: (1) phase-based; (2) anatomic similarity- and abdominal displacement-based sorting for five patients. Two ventilation image sets (V_phase and V_anat) were then calculated by deformable image registration of peak-exhale and peak-inhale4D-CT images and quantification of regional volume change based on Hounsfield unit change. The variability of 4D-CT ventilation imaging wasquantified using the voxel-based Spearman rank correlation coefficients and Dice similarity coefficients (DSC) for the spatial overlap of segmented low- functional lung regions. The relationship between the abdominal motionrange variation and ventilation variation was also assessed using linearregression. Furthermore, the correlations between V_phase or V_anat and SPECT ventilation images (assumed ground-truth) were compared.

RESULTS

In general, displacement- and anatomic similarity-based sorting reduced 4D- CT artifacts compared to phase-based sorting. The voxel-based correlationsbetween V_phase and V_anat were only moderate (range, 0.57-0.77). The DSCs for the low-functional lung regions were moderate to substantial (0.58-0.70). The relationship between the motion range variation and ventilation variation was strong on average (R2=0.79±0.25), suggesting that ventilation variations are related to 4D-CT artifacts. Vanat was found to improve correlations with SPECT ventilation images compared to V_phase.

CONCLUSIONS

4D-CT ventilation images vary markedly with 4D-CT sorting techniques. 4D-CT artifacts should be considered as a significant source of variation in 4D-CT ventilation imaging during its validation. This study wassupported in part by NIH/NCI R01 93626. SK and CL are employees ofPhilips Research.

Expression profiles of LHbeta, FSHbeta and their gonadal receptor mRNAs during sexual differentiation of Xenopus laevis tadpoles

The gonadotropins, luteinising hormone (LH) and follicle stimulating hormone (FSH), are important hormones regulating reproductive biology in vertebrates, especially the processes of steroidogenesis and gamete maturation. Despite the role of gonadotropins during the reproductive cycle in amphibians is well established, much less is known about the functional maturation of the hypothalamus-pituitary-gonad axis during larval development. Therefore, the present study aimed to analyze the expression profiles of hypophyseal LHbeta and FSHbeta mRNA and of their corresponding gonadal receptors (LH-R, FSH-R) in Xenopus laevis tadpoles during their ontogeny and sexual differentiation. The first significant elevation of LHbeta and FSHbeta mRNA was observed at late premetamorphosis. A clear raise of LHbeta mRNA was present during prometamorphic stages especially in males, while the LH-R only slowly increased during ontogeny with highest levels during metamorphic climax. In contrast, FSHbeta mRNA expression only slightly increased during ontogeny, however in both sexes the FSH-R mRNA was considerably elevated at prometamorphosis and further at metamorphic climax. Our results suggest that LHbeta and LH-R mRNA expression might be involved in initial maturation events of gametes, at least in males, while the gradually increase of FSH-R mRNA coincided with the advancing process of gamete maturation in both sexes. The present study provides for the first time evidence based on expression of gonadotropins and their corresponding gonadal receptors that the hypothalamus-pituitary-gonad axis evolves already at early stages of ontogeny and sexual differentiation in amphibians.

Genomic SELEX for Hfq-binding RNAs identifies genomic aptamers predominantly in antisense transcripts

An unexpectedly high number of regulatory RNAs have been recently discovered that fine-tune the function of genes at all levels of expression. We employed Genomic SELEX, a method to identify protein-binding RNAs encoded in the genome, to search for further regulatory RNAs in Escherichia coli. We used the global regulator protein Hfq as bait, because it can interact with a large number of RNAs, promoting their interaction. The enriched SELEX pool was subjected to deep sequencing, and 8865 sequences were mapped to the E. coli genome. These short sequences represent genomic Hfq-aptamers and are part of potential regulatory elements within RNA molecules. The motif 5′-AAYAAYAA-3′ was enriched in the selected RNAs and confers low-nanomolar affinity to Hfq. The motif was confirmed to bind Hfq by DMS footprinting. The Hfq aptamers are 4-fold more frequent on the antisense strand of protein coding genes than on the sense strand. They were enriched opposite to translation start sites or opposite to intervening sequences between ORFs in operons. These results expand the repertoire of Hfq targets and also suggest that Hfq might regulate the expression of a large number of genes via interaction with cis-antisense RNAs.

Patient-reported outcomes in hernia repair

BACKGROUND

The project aimed at testing the feasibility of a quality improvement system based on patient-reported outcomes in short-stay surgery for groin hernia repair.

METHODS

In two centres for short-stay surgery all patients referred for hernia repair were surveyed between August 1999 and January 2002. Patients reported on health-related quality of life (SF-36), symptoms (Hernia Symptom Checklist, HSCL) and other indicators pre-operatively (T0) and 14 days (T1) and 6 months post-operatively (T2). Three of the eight SF-36 subscales (physical functioning, bodily pain, and role physical) and the HSCL at T2 were considered as main outcome indicators. The main outcomes were analysed by generalized linear models with regard to predictors.

RESULTS

At T0 a total of 342 hernia patients were included. The response rate at T2 was 54.1% (92.4% males, 58.6 years of age). At T2 only 21.1% did not report complaints (i.e. haematoma, pain, numbness) post-operatively. The overall positive course is reflected by the HSCL: from 32.4% pre-operatively, it rises slightly to 38.5% at T1 and decreases to 10.6% at T2 (T0-T2: P < 0.001). The SF-36 subscales "physical functioning", "bodily pain", and "role physical" showed the same course over time (slight decrease of health-related quality of life at T1 and large increase at T2). The main patient-reported outcomes were mainly influenced by the pre-operative level, age, and self-reported post-operative complaints.

CONCLUSION

The low response rate was mainly due to non-delivery of questionnaires at T1 during the regular post-operative visit by the operating physician. Though non-response occurs under conditions of routine care, meaningful information was gained which should be used for quality improvement activities. Because the pre-operative level is a major determinant of the post-operative health outcomes, the prospective pre-post measurement should be standard, in case institutional comparisons are intended.

A geometric model of the beating heart

OBJECTIVES

A comprehensive model of the human heart that covers multiple surfaces, like those of the four chambers and the attached vessels, is presented. It also contains the coronary arteries and a set of 25 anatomical landmarks. The statistical model is intended to provide a priori information for automated diagnostic and interventional procedures.

METHODS

The end-diastolic phase of the model was adapted to fit 27 clinical multi-slice computed tomography images, thus reflecting the anatomical variability to be observed in that sample. A mean cardiac motion model was also calculated from a set of eleven multi-phase computed tomography image sets. A number of experiments were performed to determine the accuracy of model-based predictions done on unseen cardiac images.

RESULTS

Using an additional deformable surface technique, the model allows for determination of all chambers and the attached vessels on the basis of given anatomical landmarks with an average accuracy of 1.1 mm. After such an individualization of the model by surface adaptation the centerlines of the three main coronary arteries may be estimated with an average accuracy of 5.2 mm. The mean motion model was used to estimate the cardiac phase of an unknown multi-slice computed tomography image.

CONCLUSION

The mean shape model of the human heart as presented here complements automated image analysis methods with the required a priori information about anatomical constraints to make them work fast and robustly.

Evaluation von zwei „schnellen” Softwareprogrammen zur Bestimmung der linksventrikulären Volumina in der retrospektiv EKG-gegateten Mehrzeilen-Spiral-CT des Schweineherzens: Biplanare Flächen-Längen-Methode und „Shape-tracking”-Methode

PURPOSE

Evaluation of 2 "fast" software tools, a biplane area-length method, and a new automatic "shape tracking" method, for the calculation of left ventricle volumes (end-diastolic volume EDV, end-systolic volume ESV, stroke volume SV) and ejection fraction (EF) in retrospectively ECG-gated multidetector computed tomography.

MATERIALS AND METHODS

60 contrast-enhanced cardiac CT datasets (16 x 0.75 mm collimation, normal dose: 120-140 kV, 400-500 mAs (eff) [n = 44], low dose 120 kV, 100 mAs (eff) [n = 16]) were acquired from eight intubated healthy pigs on different days. Images were reconstructed with a slice thickness and increment of 2 mm every 10 % of the cardiac cycle. The LV function was evaluated via the common short axis method as the reference method, the biplane area-length method, and the automatic "shape tracking" method. In the latter a three-dimensional triangulated deformable surface model was used to segment the endocardial border of the left ventricle and to track its motion through the cardiac phases. The results were compared using the Bland-Altman-plot, the correlation coefficient, and the Wilcoxon test.

RESULTS

All 60 data sets could be evaluated with all three methods. Good correlations were found for left ventricular functional parameters for all data sets, the normal dose (ND), and low dose (LD) data sets between 0.65 and 0.89 for the "shape tracking" method and between 0.7 and 0.87 for the area-length method. The "shape tracking" method showed a mean overestimation of the EDV of 3.1 (LD, p = 0.38) to 4.3 ml (ND, p < 0.05), the SV of 4.0 (LD, p = 0.08) to 4.9 ml (ND, p < 0.05) and the EF of 1.3 (LD, p = 0.16) to 2.0 % (ND, p < 0.05). The EDV was underestimated between 0.3 (LD, p = 0.7) and 1.1 ml (ND, p = 0.08). The area-length method showed an overestimation of the EDV (6.6 to 6.7 ml [p < 0.05]), the SV (5.9 to 8.4 ml [p < 0.05]), the EF (1.2 to 3.0 % [p < 0.05]) and the normal dose ESV (0.6 ml [p = 0.74]). The low dose ESV was underestimated (1.3 ml [p = 0.21]).

CONCLUSION

The left ventricular functional parameters acquired with both "fast" software methods correlate well with the common semi-automatic short axis method, and both methods significantly overestimate the EDV, SV and EF. Both methods can be used in low dose examinations.