Vernalization Alters Sink and Source Identities and Reverses Phloem Translocation from Taproots to Shoots in Sugar Beet.

During their first year of growth, overwintering biennial plants transport Suc through the phloem from photosynthetic source tissues to storage tissues. In their second year, they mobilize carbon from these storage tissues to fuel new growth and reproduction. However, both the mechanisms driving this shift and the link to reproductive growth remain unclear. During vegetative growth, biennial sugar beet (Beta vulgaris) maintains a steep Suc concentration gradient between the shoot (source) and the taproot (sink). To shift from vegetative to generative growth, they require a chilling phase known as vernalization. We studied sugar beet sink-source dynamics upon vernalization and showed that before flowering, the taproot underwent a reversal from a sink to a source of carbohydrates. This transition was induced by transcriptomic and functional reprogramming of sugar beet tissue, resulting in a reversal of flux direction in the phloem. In this transition, the vacuolar Suc importers and exporters TONOPLAST SUGAR TRANSPORTER2;1 and SUCROSE TRANSPORTER4 were oppositely regulated, leading to the mobilization of sugars from taproot storage vacuoles. Concomitant changes in the expression of floral regulator genes suggest that these processes are a prerequisite for bolting. Our data will help both to dissect the metabolic and developmental triggers for bolting and to identify potential targets for genome editing and breeding.

Multi-omics data integration reveals link between epigenetic modifications and gene expression in sugar beet (Beta vulgaris subsp. vulgaris) in response to cold.

BACKGROUND: DNA methylation is thought to influence the expression of genes, especially in response to changing environmental conditions and developmental changes. Sugar beet (Beta vulgaris ssp. vulgaris), and other biennial or perennial plants are inevitably exposed to fluctuating temperatures throughout their lifecycle and might even require such stimulus to acquire floral competence. Therefore, plants such as beets, need to fine-tune their epigenetic makeup to ensure phenotypic plasticity towards changing environmental conditions while at the same time steering essential developmental processes. Different crop species may show opposing reactions towards the same abiotic stress, or, vice versa, identical species may respond differently depending on the specific kind of stress. RESULTS: In this study, we investigated common effects of cold treatment on genome-wide DNA methylation and gene expression of two Beta vulgaris accessions via multi-omics data analysis. Cold exposure resulted in a pronounced reduction of DNA methylation levels, which particularly affected methylation in CHH context (and to a lesser extent CHG) and was accompanied by transcriptional downregulation of the chromomethyltransferase CMT2 and strong upregulation of several genes mediating active DNA demethylation. CONCLUSION: Integration of methylomic and transcriptomic data revealed that, rather than methylation having directly influenced expression, epigenetic modifications correlated with changes in expression of known players involved in DNA (de)methylation. In particular, cold triggered upregulation of genes putatively contributing to DNA demethylation via the ROS1 pathway. Our observations suggest that these transcriptional responses precede the cold-induced global DNA-hypomethylation in non-CpG, preparing beets for additional transcriptional alterations necessary for adapting to upcoming environmental changes.

A methodology for the assessment of inhalation exposure to aluminium from antiperspirant sprays.

Inhalative exposure can occur accidentally when using cosmetic spray products. Usually, a tiered approach is applied for exposure assessment, starting with rather conservative, simplistic calculation models that may be improved with measured data and more refined modelling. Here we report on an advanced methodology to mimic in-use conditions for antiperspirant spray products to provide a more accurate estimate of the amount of aluminium possibly inhaled and taken up systemically, thus contributing to the overall body burden. Four typical products were sprayed onto a skin surrogate in defined rooms. For aluminium, size-related aerosol release fractions, i.e. inhalable, thoracic and respirable, were determined by a mass balance method taking droplet maturation into account. These data were included into a simple two-box exposure model, allowing calculation of the inhaled aluminium dose over 12 min. Systemic exposure doses were calculated for exposure of the deep lung and the upper respiratory tract using the Multiple Path Particle Deposition Model (MPPD) model. The total systemically available dose of aluminium was in all cases found to be less than 0.5 µg per application. With this study it could be demonstrated that refinement of the input data of the two-box exposure model with measured data of released airborne aluminium is a valuable approach to analyse the contribution of antiperspirant spray inhalation to total aluminium exposure as part of the overall risk assessment. We suggest the methodology which can also be applied to other exposure modelling approaches for spray products, and further is adapted to other similar use scenarios.

Specificity and reproducibility of nasal biomarkers in patients with allergic rhinitis after allergen challenge chamber exposure.

BACKGROUND: Allergic rhinitis is an inflammatory disease that causes cellular influx and mediator release in the nose. These inflammatory changes might be used as nasal biomarkers to assess the efficacy of novel anti-allergic treatments. OBJECTIVE: To assess the specificity and reproducibility of nasal biomarkers in patients with allergic rhinitis after grass pollen exposure in an allergen challenge chamber. METHODS: In a monocenter pilot study, 15 patients with allergic rhinitis and 19 healthy individuals underwent two 4-hour Dactylis glomerate pollen challenges in the challenge chamber with an interval of 21 days. Before challenge, on exit, and after 2 and 22 hours, a nasal lavage was performed and nasal secretions were collected on filter paper to determine a wide panel of cells and mediators. Furthermore, total nasal symptom score, nasal flow, and nasal nitric oxide were measured. RESULTS: Pollen exposure significantly increased eosinophil, interleukin (IL) 5, IL-6, IL-13, and macrophage inflammatory protein 1ß levels in allergic patients but not in healthy individuals. The effect could be reproduced for eosinophils, IL-5, IL-6, and macrophage inflammatory protein 1ß after the second allergen challenge. By contrast, the IL-13 levels were higher and eotaxin levels first increased after repetitive allergen challenge. There was no correlation between total nasal symptom score and elevated cell or cytokine levels. Nasal nitric oxide levels were nonspecifically elevated in both patients with allergy and healthy controls. CONCLUSION: A subset of cellular and soluble biomarkers in nasal lavage and secretion reveals specificity and reproducibility in patients with allergic rhinitis. These can be used to measure the immunologic efficacy of antiallergic treatments in an allergen challenge chamber. Carryover effects attributable to priming must be considered when designing cross-over studies. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00297843.

Thoracic and respirable aerosol fractions of spray products containing non-volatile compounds.

A versatile and simple mass balance method for the measurement of the release fraction of thoracic and respirable particles of non-volatile compounds of spray products is presented. The release fractions are defined as the ratio between the mass of suspended non-volatile particulate matter in the thoracic and respirable particle size range and the total mass of non-volatile material released with the spray action. For its determination, a spray bolus of short duration and of defined mass is sprayed into a well stirred control chamber. The respirable and thoracic aerosol mass associated with the spray bolus is determined by measuring the time averaged mass concentration inside the control volume and the half time of the exponential concentration decrease to be expected in well stirred systems to correct for mass losses during sampling. The method is used for a wide range of spray products and technologies for which the release fractions vary by orders of magnitude. A set of data is presented elucidating the relationship between spray technology and fine particle release. Furthermore, a simple rule of thumb was derived from the data that allows for estimation of the release fractions based on a characteristic diameter of the spray droplets. The usefulness of the mass balance method for substance classification as well as for generating input data for exposure assessment and indoor air quality modeling is discussed.

Approach on environmental risk assessment of nanosilver released from textiles.

Based on the increased utilization of nanosilver (silver nanomaterials=AgNM) as antibacterial agent, there is the strong need to assess the potential environmental implication associated with its new application areas. In this study an exemplary environmental risk assessment (ERA) of AgNM applied in textiles was performed. Environmental exposure scenarios (via municipal sewage treatment plant (STP)) with wastewater supply from domestic homes) were developed for three different types of textiles equipped with AgNM. Based on these scenarios predicted environmental concentrations (PECs) were deduced for STPs and for the environmental compartments surface water, sediment as well as soil. These PECs were related to PNECs (predicted no effect concentrations). PNECs were deduced from results of ecotoxicity tests of a selected AgNM (NM-300K). Data on ecotoxicology were derived from various tests with activated sludge, cyanobacteria, algae, daphnids, fish, duckweed, macrophytes, chironomids, earthworms, terrestrial plants as well as soil microorganisms. Emission data for the AgNM NM-300K from textiles were derived from washing experiments. The performed ERA was based on the specifications defined in the ECHA Guidances on information requirements and chemical safety assessment. Based on the chosen scenarios and preconditions, no environmental risk of the AgNM NM-300K released from textiles was detected. Under conservative assumptions a risk quotient for surface water close to 1 indicated that the aquatic compartment may be affected by an increased emission of AgNM to the environment due to the high sensitivity of aquatic organisms to silver. Based on the successful retention of AgNM in the sewage sludge and the still ongoing continual application of sewage sludge on farmland it is recommended to introduce a threshold for total silver content in sewage sludge into the respective regulations. Regarding potential risk mitigation measures, it is emphasized to preferably directly introduce AgNM into the textile fiber since this will strongly minimize the release of AgNM during washing. If this is not possible due to technical limitations or other reasons, the introduction of a threshold level controlling the release of AgNM from textiles is suggested. It has to be noted that this study is a case study which is only valid for the investigated NM-300K and its potential application in textiles.

Beryllium Concentrations at European Workplaces: Comparison of 'Total' and Inhalable Particulate Measurements.

A field study was carried out in order to derive a factor for the conversion of historic worker exposure data on airborne beryllium (Be) obtained by sampling according to the 37-mm closed faced filter cassette (CFC) 'total' particulate method into exposure concentration values to be expected when sampling using the 'Gesamtstaubprobenahmesystem' (GSP) inhalable sampling convention. Workplaces selected to represent the different copper Be work processing operations that typically occur in Germany and the EU were monitored revealing a broad spectrum of prevailing Be size distributions. In total, 39 personal samples were taken using a 37-mm CFC and a GSP worn side by side for simultaneous collection of the 'total' dust and the inhalable particulates, respectively. In addition, 20 static general area measurements were carried out using GSP, CFC, and Respicon samplers in parallel, the latter one providing information on the extra-thoracic fraction of the workplace aerosol. The study showed that there is a linear relationship between the concentrations measured with the CFC and those measured with the GSP sampler. The geometric mean value of the ratios of time-weighted average concentrations determined from GSP and CFC samples of all personal samples was 2.88. The individual values covered a range between 1 and 17 related to differences in size distributions of the Be-containing particulates. This was supported by the area measurements showing that the conversion factor increases with increasing values of the extra-thoracic fraction covering a range between 0 and 79%.

Global changes in diets and the consequences for land requirements for food.

Provision of food is a prerequisite for the functioning of human society. Cropland where food and feed are grown is the central, limiting resource for food production. The amount of cropland needed depends on population numbers, average food consumption patterns, and output per unit of land. Around the globe, these factors show large differences. We use data from the Food and Agriculture Organization to consistently assess subcontinental dynamics of how much land was needed to supply the prevailing diets during a span of 46 y, from 1961 to 2007. We find that, in most regions, diets became richer while the land needed to feed one person decreased. A decomposition approach is used to quantify the contributions of the main drivers of cropland requirements for food: changes in population, agricultural technology, and diet. We compare the impact of these drivers for different subcontinents and find that potential land savings through yield increases were offset by a combination of population growth and dietary change. The dynamics of the three factors were the largest in developing regions and emerging economies. The results indicate an inverse relationship between the two main drivers behind increased land requirements for food: with socioeconomic development, population growth decreases and, at the same time, diets become richer. In many regions, dietary change may override population growth as major driver behind land requirements for food in the near future.

Effects of ultrafine particles on the allergic inflammation in the lung of asthmatics: results of a double-blinded randomized cross-over clinical pilot study.

BACKGROUND: Epidemiological and experimental studies suggest that exposure to ultrafine particles (UFP) might aggravate the allergic inflammation of the lung in asthmatics. METHODS: We exposed 12 allergic asthmatics in two subgroups in a double-blinded randomized cross-over design, first to freshly generated ultrafine carbon particles (64 µg/m³; 6.1 ± 0.4 × 105 particles/cm³ for 2 h) and then to filtered air or vice versa with a 28-day recovery period in-between. Eighteen hours after each exposure, grass pollen was instilled into a lung lobe via bronchoscopy. Another 24 hours later, inflammatory cells were collected by means of bronchoalveolar lavage (BAL). ( TRIAL REGISTRATION: NCT00527462) RESULTS: For the entire study group, inhalation of UFP by itself had no significant effect on the allergen induced inflammatory response measured with total cell count as compared to exposure with filtered air (p = 0.188). However, the subgroup of subjects, which inhaled UFP during the first exposure, exhibited a significant increase in total BAL cells (p = 0.021), eosinophils (p = 0.031) and monocytes (p = 0.013) after filtered air exposure and subsequent allergen challenge 28 days later. Additionally, the potential of BAL cells to generate oxidant radicals was significantly elevated at that time point. The subgroup that was exposed first to filtered air and 28 days later to UFP did not reveal differences between sessions. CONCLUSIONS: Our data demonstrate that pre-allergen exposure to UFP had no acute effect on the allergic inflammation. However, the subgroup analysis lead to the speculation that inhaled UFP particles might have a long-term effect on the inflammatory course in asthmatic patients. This should be reconfirmed in further studies with an appropriate study design and sufficient number of subjects.

A generic approach to estimate airborne concentrations of substances released by indoor spray processes using a deterministic 2-box model.

Sprays are used both in workplace and consumer settings. Although spraying has advantages, such as uniform distribution of substances on surfaces in a highly efficient manner, it is often associated with a high inhalation burden. For an adequate risk assessment, this exposure has to be reliably quantified. Exposure models of varying complexity are available, which are applicable to spray applications. However, a need for improvement has been identified. In this contribution, a simple 2-box approach is suggested for the assessment of the time-weighted averaged exposure concentration (TWA) using a minimum of input data. At the moment, the model is restricted to binary spray liquids composed of a non-volatile fraction and volatile solvents. The model output can be refined by introducing correction factors based on the classification and categorization of two key parameters, the droplet size class and the vapor pressure class of the solvent, or by using a data set of experimentally determined airborne release fractions related to the used spray equipment. A comparison of model results with measured data collected at real workplaces showed that this simple model based on readily available input parameters is very useful for screening purposes. The generic 2-box spray model without refinement overestimates the measurements of the considered scenarios in approximately 50% of the cases by more than a factor of 100. The generic 2-box model performs better for room spraying than for surface spraying, as the airborne fraction in the latter case is clearly overestimated. This conservatism of the prediction was significantly reduced when correction factors or experimentally determined airborne release fractions were used in addition to the generic input parameters. The resulting predictions still overestimate the exposure (ratio tool estimate to measured TWA > 10) or they are accurate (ratio 0.5-10). If the available information on boundary conditions (application type, equipment) does not justify the usage of airborne release fraction, room spraying should be used resulting in the highest exposure estimate. The model scope may be extended to (semi)volatile substances. However, acceptance may be compromised by the limited availability of measured data for this group of substances and thus may have limited potency to evaluate the model prediction.

Siliques are Red1 from Arabidopsis acts as a bidirectional amino acid transporter that is crucial for the amino acid homeostasis of siliques.

Many membrane proteins are involved in the transport of nutrients in plants. While the import of amino acids into plant cells is, in principle, well understood, their export has been insufficiently described. Here, we present the identification and characterization of the membrane protein Siliques Are Red1 (SIAR1) from Arabidopsis (Arabidopsis thaliana) that is able to translocate amino acids bidirectionally into as well as out of the cell. Analyses in yeast and oocytes suggest a SIAR1-mediated export of amino acids. In Arabidopsis, SIAR1 localizes to the plasma membrane and is expressed in the vascular tissue, in the pericycle, in stamen, and in the chalazal seed coat of ovules and developing seeds. Mutant alleles of SIAR1 accumulate anthocyanins as a symptom of reduced amino acid content in the early stages of silique development. Our data demonstrate that the SIAR1-mediated export of amino acids plays an important role in organic nitrogen allocation and particularly in amino acid homeostasis in developing siliques.

Aerosol formation during foam application of non-volatile biocidal substances.

The application of biocidal products by foam is considered an alternative to droplet spraying when disinfecting surfaces or fighting infestations. Inhalation exposure to aerosols containing the biocidal substances cannot be ruled out during foaming. In contrast to droplet spraying, very little is known about aerosol source strength during foaming. In this study, the formation of inhalable aerosols was quantified according to the aerosol release fractions of the active substance. The aerosol release fraction is defined as the mass of active substance transferred into inhalable airborne particles during foaming, normalised to the total amount of active substance released through the foam nozzle. Aerosol release fractions were measured in control chamber experiments where common foaming technologies were operated according to their typical conditions of use. These investigations include foams generated mechanically by actively mixing air with a foaming liquid as well as systems that use a blowing agent for foam formation. The values of the aerosol release fraction ranged from 3.4 × 10-6 to 5.7 × 10-3 (average values). For foaming processes based on mixing air and the foaming liquid, the release fractions could be correlated to the process and foam parameters such as foam exit velocity, nozzle dimensions, and foam expansion ratio.

Inhalation and dermal exposure to biocidal products during foam and spray applications.

OBJECTIVES: Foaming and spraying are common application techniques for biocidal products. In the past, inhalation and dermal exposure during spraying have been investigated extensively. Currently, however, no exposure data are available for foaming, hindering a reliable risk assessment for foam applications of biocidal products. The focus of this project was the quantification of inhalation and potential dermal exposure to non-volatile active substances during the foam application of biocidal products in occupational settings. In some settings, exposure during spray application was measured for comparative purposes. METHODS: The inhalation and dermal exposure of operators were investigated during the application of benzalkonium chlorides and pyrethroids by foaming and spraying, considering both small- and large-scale application devices. Inhalation exposure was measured by personal air sampling; potential dermal exposure was measured using coveralls and gloves. RESULTS: Potential dermal exposure was substantially higher than inhalation exposure. Changing from spraying to foaming reduced inhalation exposure to airborne non-volatile active substances, but had no relevant effect on potential dermal exposure. However, for potential dermal exposure, considerable differences were observed between the application device categories. CONCLUSIONS: To our knowledge, this study presents the first comparative exposure data for the foam and spray application of biocidal products in occupational settings with detailed contextual information. The results indicate a reduction of inhalation exposure with foam application compared to spray application. However, special attention is necessary for dermal exposure, which is not reduced by this intervention.

An image classification approach to analyze the suppression of plant immunity by the human pathogen Salmonella Typhimurium.

BACKGROUND: The enteric pathogen Salmonella is the causative agent of the majority of food-borne bacterial poisonings. Resent research revealed that colonization of plants by Salmonella is an active infection process. Salmonella changes the metabolism and adjust the plant host by suppressing the defense mechanisms. In this report we developed an automatic algorithm to quantify the symptoms caused by Salmonella infection on Arabidopsis. RESULTS: The algorithm is designed to attribute image pixels into one of the two classes: healthy and unhealthy. The task is solved in three steps. First, we perform segmentation to divide the image into foreground and background. In the second step, a support vector machine (SVM) is applied to predict the class of each pixel belonging to the foreground. And finally, we do refinement by a neighborhood-check in order to omit all falsely classified pixels from the second step. The developed algorithm was tested on infection with the non-pathogenic E. coli and the plant pathogen Pseudomonas syringae and used to study the interaction between plants and Salmonella wild type and T3SS mutants. We proved that T3SS mutants of Salmonella are unable to suppress the plant defenses. Results obtained through the automatic analyses were further verified on biochemical and transcriptome levels. CONCLUSION: This report presents an automatic pixel-based classification method for detecting "unhealthy" regions in leaf images. The proposed method was compared to existing method and showed a higher accuracy. We used this algorithm to study the impact of the human pathogenic bacterium Salmonella Typhimurium on plants immune system. The comparison between wild type bacteria and T3SS mutants showed similarity in the infection process in animals and in plants. Plant epidemiology is only one possible application of the proposed algorithm, it can be easily extended to other detection tasks, which also rely on color information, or even extended to other features.

Pollen starch granules in bronchial inflammation.

BACKGROUND: Pollen grains with a diameter of more than 10 µm preferentially deposit in the upper airways. Their contribution to lower airway inflammation is unclear. One hypothesis is that lower airway inflammation is mainly caused by allergen containing pollen starch granules, which are released from the pollen grains and can easily enter the peripheral airways because of their smaller size. OBJECTIVE: To investigate the differential effect of pollen grains and pollen starch granules on nasal symptoms and lower airway inflammation. METHODS: In a 2-period crossover design, 30 patients with allergic rhinitis and mild intermittent asthma underwent 2 allergen challenges on consecutive days in an environmental challenge chamber with either a mixture of pollen grains plus starch granules or starch granules only. End points were the total nasal symptom score (TNSS), nasal secretion weight, nasal flow, spirometry, and exhaled nitric oxide (eNO). RESULTS: The presence of pollen grains had a significant and considerable effect on increase in TNSS and secretion weight and on decrease in nasal flow. Starch granules alone only had minimal effects on nasal symptoms. Challenges with starch granules significantly increased eNO. Pollen had no effect on eNO. CONCLUSION: Pollen grains cause nasal symptoms but do not augment lower airway inflammation, whereas starch granules trigger lower airway inflammation but hardly induce nasal symptoms.

Change in agglomeration status and toxicokinetic fate of various nanoparticles in vivo following lung exposure in rats.

The deposition characteristics in lungs following inhalation, the potential toxic effects induced and the toxicokinetic fate including a possible translocation to other sites of the body are predominantly determined by the agglomeration status of nanoscaled primary particles. Systemic particle effects, i.e. effects on remote organs besides the respiratory tract are considered to be of relevant impact only for de-agglomerated particles with a nanoscaled aspect. Rats were exposed to various types of nanoscaled particles, i.e. titanium dioxide, carbon black and constantan. These were dispersed in physiologically compatible media, e.g. phosphate buffer, sometimes including auxiliaries. Rats were treated with aqueous nanoparticle dispersions by intratracheal instillation or were exposed to well-characterized nanoparticle aerosols. Subsequently, alterations in the particle size distribution were studied using transmission electron microscopy (TEM) as well as the bronchoalveolar lavage (BAL) technique. Based on the results in various approaches, a tendency of nanoscaled particles to form larger size agglomerates following deposition and interaction with cells or the respiratory tract is predominant. The contrary trend, i.e. the increase of particle number due to a disintegration of agglomerates seems not to be of high relevance.

A common toxin fold mediates microbial attack and plant defense.

Many plant pathogens secrete toxins that enhance microbial virulence by killing host cells. Usually, these toxins are produced by particular microbial taxa, such as bacteria or fungi. In contrast, many bacterial, fungal and oomycete species produce necrosis and ethylene-inducing peptide 1 (Nep1)-like proteins (NLPs) that trigger leaf necrosis and immunity-associated responses in various plants. We have determined the crystal structure of an NLP from the phytopathogenic oomycete Pythium aphanidermatum to 1.35A resolution. The protein fold exhibits structural similarities to cytolytic toxins produced by marine organisms (actinoporins). Computational modeling of the 3-dimensional structure of NLPs from another oomycete, Phytophthora parasitica, and from the phytopathogenic bacterium, Pectobacterium carotovorum, revealed a high extent of fold conservation. Expression of the 2 oomycete NLPs in an nlp-deficient P. carotovorum strain restored bacterial virulence, suggesting that NLPs of prokaryotic and eukaryotic origins are orthologous proteins. NLP mutant protein analyses revealed that identical structural properties were required to cause plasma membrane permeabilization and cytolysis in plant cells, as well as to restore bacterial virulence. In sum, NLPs are conserved virulence factors whose taxonomic distribution is exceptional for microbial phytotoxins, and that contribute to host infection by plasma membrane destruction and cytolysis. We further show that NLP-mediated phytotoxicity and plant defense gene expression share identical fold requirements, suggesting that toxin-mediated interference with host integrity triggers plant immunity-associated responses. Phytotoxin-induced cellular damage-associated activation of plant defenses is reminiscent of microbial toxin-induced inflammasome activation in vertebrates and may thus constitute another conserved element in animal and plant innate immunity.

A pilot study on the refinement of acute inhalation toxicity studies: the isolated perfused rat lung as a screening tool for surface-active substances.

New surface-active agents in waterproofing sprays are frequently tested for acute inhalation toxicity in vivo according to OECD Test Guideline 403. In order to refine and reduce the number of acute inhalation tests performed, we propose a screening test that uses isolated lungs. The test consists of the exposure of isolated, ventilated and perfused rat lungs, to aerosolised formulations of waterproofing agents (mass median aerodynamic diameter = 1µm), and on-line monitoring of respiratory parameters and gross pathology analysis. A pilot evaluation of the isolated perfused rat lung model for use in a screening test was carried out by blind testing 12 surface-active substances. The results obtained compared well with data available from in vivo acute inhalation studies. Substances that triggered harmful effects, such as impaired lung compliance and atelectasis of the isolated perfused lung, were also found to cause changes in respiratory parameters, some of which would be severe enough to lead to death in in vivo tests with rats. The changes in respiratory parameters suggest that the mode-of-action is associated with impairment of the surfactant layer. Therefore, pre-testing in the isolated perfused rat lung allows the identification of surface-active substances with the potential for causing acute inhalation toxicity.

Exploiting protease activation for therapy.

Proteases have crucial roles in homeostasis and disease; and protease inhibitors and recombinant proteases in enzyme replacement therapy have become key therapeutic applications of protease biology across several indications. This review briefly summarises therapeutic approaches based on protease activation and focuses on how recent insights into the spatial and temporal control of the proteolytic activation of growth factors and interleukins are leading to unique strategies for the discovery of new medicines. In particular, two emerging areas are covered: the first is based on antibody therapies that target the process of proteolytic activation of the pro-form of proteins rather than their mature form; the second covers a potentially new class of biopharmaceuticals using engineered, proteolytically activable and initially inactive pro-forms of antibodies or effector proteins to increase specificity and improve the therapeutic window.

The effect of radiofrequency electromagnetic fields (RF-EMF) on biomarkers of oxidative stress in vivo and in vitro: A protocol for a systematic review.

BACKGROUND: Oxidative stress is conjectured to be related to many diseases. Furthermore, it is hypothesized that radiofrequency fields may induce oxidative stress in various cell types and thereby compromise human and animal health. This systematic review (SR) aims to summarize and evaluate the literature related to this hypothesis. OBJECTIVES: The main objective of this SR is to evaluate the associations between the exposure to radiofrequency electromagnetic fields and oxidative stress in experimental models (in vivo and in vitro). METHODS: The SR framework has been developed following the guidelines established in the WHO Handbook for Guideline Development and the Handbook for Conducting a Literature-Based Health Assessment). We will include controlled in vivo and in vitro laboratory studies that assess the effects of an exposure to RF-EMF on valid markers for oxidative stress compared to no or sham exposure. The protocol is registered in PROSPERO. We will search the following databases: PubMed, Embase, Web of Science Core Collection, Scopus, and the EMF-Portal. The reference lists of included studies and retrieved review articles will also be manually searched. STUDY APPRAISAL AND SYNTHESIS METHOD: Data will be extracted according to a pre-defined set of forms developed in the DistillerSR online software and synthesized in a meta-analysis when studies are judged sufficiently similar to be combined. If a meta-analysis is not possible, we will describe the effects of the exposure in a narrative way. RISK OF BIAS: The risk of bias will be assessed with the NTP/OHAT risk of bias rating tool for human and animal studies. We will use GRADE to assess the certainty of the conclusions (high, moderate, low, or inadequate) regarding the association between radiofrequency electromagnetic fields and oxidative stress. FUNDING: This work was funded by the World Health Organization (WHO). REGISTRATION: The protocol was registered on the PROSPERO webpage on July 8, 2021.