Total loss and distribution of nitrogen and phosphorus in the outdoor run of organic laying hens.

1. The objective of this study was to determine the level and variation of the total mass, and load of nitrogen (N) and phosphorus (P) excreted into the outdoor run of organic egg production systems. 2. Three egg production farms with an aviary system and an outdoor run were selected for this study. Four measurements, one per season, were executed on each farm. 3. Mean content of N and P of a manure dropping was 14·0 g N kg⁻¹ and 3·12 g P kg⁻¹, mean mass of a dropping was 6·36 g and mean dry matter content of a dropping was 238 g kg⁻¹. Mean rate of excretion in the outdoor run was 2·99 droppings per hen per h. Mean percentage of hens outside during the time the outdoor run could be accessed was lowest on Farm 1 (1·7%), highest on Farm 2 (16·0%), and intermediate on Farm 3 (7·1%). 4. On all farms an exponential decrease of the number of hens and of the load of N and P with increasing distance from the hen house was found. Load of N exceeded the fertilisation standard (of 170 kg ha⁻¹y⁻¹) in the region at a 0 to 19 m distance from the hen house on Farm 1, 0 to 146 m on Farm 2 and 0 to 52 m on Farm 3. 5. It is concluded that the husbandry system should be redesigned to solve the problem of overloading, unwanted loss of N and P to the environment and loss of N and P from the organic production cycle.

Soil self-cleaning capacity: Removal of organic compounds during sub-surface irrigation with sewage effluent.

Globally, the reuse of treated sewage effluent for irrigation purposes is increasingly encouraged as a practical solution against the mismatch between the demand for and availability of freshwater resources. The reuse of sewage effluent for sub-surface irrigation (SSI) in agriculture serves the dual purpose of supplying water to crops and diminishing emissions of contaminants of emerging concern (CoECs) into surface water. To investigate such reuse, in a real scale cropland with SSI using sewage effluent, from September 2017 to March 2019 including the extremely dry year 2018, residues were followed of 133 CoECs as related to their physicochemical properties and quantified by liquid chromatography coupled to high-resolution mass spectrometry. Of the 133 target CoECs, 89 were retrieved in the field, most non-detect CoECs have low persistency. During the growing season with sub-surface irrigation, CoECs spread to the shallow groundwater and rhizosphere. Significantly lower concentrations are found between infiltration pipes as compared to directly next to the pipes in shallow groundwater for all persistency-mobility classes. CoECs belonging to the class pm (low persistency and low mobility) or class PM (high persistency and high mobility) class show no change amongst their removal in the rhizosphere and groundwater in a dry versus normal year. CoECs belonging to the class pM (low persistency and high mobility) show high seasonal dynamics in the rhizosphere and shallow groundwater, indicating that these CoECs break down. CoECs of the class Pm (high persistency and low mobility) only significantly build up in the rhizosphere next to infiltration pipes. Climatic conditions with dry summers and precipitation surplus and drainage in winter strongly affect the fate of CoECs. During the dry summer of 2018 infiltrated effluent is hardly diluted, resulting in significantly higher concentrations for the CoECs belonging to the classes pM and Pm. After the extremely dry year of 2018, cumulative concentrations are still significantly higher, while after a normal year during winter precipitation surplus removes CoECs. For all persistency-mobility classes in the shallow groundwater between the pipes, we find significant removal efficiencies. For the rhizosphere between the pipes, we find the same except for Pm. Next to the pipes however we find no significant removal for all classes in both the rhizosphere and shallow groundwater and even significant accumulation for Pm. For this group of persistent moderately hydrophobic CoECs risk characterization ratio's were calculated for the period of time with the highest normalized concentration. None of the single-chemical RCRs are above one and the ΣRCR is also far below one, implying sufficiently safe ambient exposures. Overall the deeper groundwater (7.0-11.8 m below soil surface) has the lowest response to the sub-surface irrigation for all persistency-mobility. When adopting a SSI STP effluent reuse system care must be taken to monitor the CoECs that are (moderately) hydrophobic as these can build up in the SSI system. For the deeper groundwater and for the discharge to the surface water, we find significant removal for the pM and the PM class but not for other classes. In conclusion, relatively high removal efficiencies are shown benefiting the surface waters that would otherwise receive the STP effluent directly.

Inflammatory and regenerative processes in bioresorbable synthetic pulmonary valves up to two years in sheep-Spatiotemporal insights augmented by Raman microspectroscopy.

In situ heart valve tissue engineering is an emerging approach in which resorbable, off-the-shelf available scaffolds are used to induce endogenous heart valve restoration. Such scaffolds are designed to recruit endogenous cells in vivo, which subsequently resorb polymer and produce and remodel new valvular tissue in situ. Recently, preclinical studies using electrospun supramolecular elastomeric valvular grafts have shown that this approach enables in situ regeneration of pulmonary valves with long-term functionality in vivo. However, the evolution and mechanisms of inflammation, polymer absorption and tissue regeneration are largely unknown, and adverse valve remodeling and intra- and inter-valvular variability have been reported. Therefore, the goal of the present study was to gain a mechanistic understanding of the in vivo regenerative processes by combining routine histology and immunohistochemistry, using a comprehensive sheep-specific antibody panel, with Raman microspectroscopy for the spatiotemporal analysis of in situ tissue-engineered pulmonary valves with follow-up to 24 months from a previous preclinical study in sheep. The analyses revealed a strong spatial heterogeneity in the influx of inflammatory cells, graft resorption, and foreign body giant cells. Collagen maturation occurred predominantly between 6 and 12 months after implantation, which was accompanied by a progressive switch to a more quiescent phenotype of infiltrating cells with properties of valvular interstitial cells. Variability among specimens in the extent of tissue remodeling was observed for follow-up times after 6 months. Taken together, these findings advance the understanding of key events and mechanisms in material-driven in situ heart valve tissue engineering. STATEMENT OF SIGNIFICANCE: This study describes for the first time the long-term in vivo inflammatory and regenerative processes that underly in situ heart valve tissue engineering using resorbable synthetic scaffolds. Using a unique combinatorial analysis of immunohistochemistry and Raman microspectroscopy, important spatiotemporal variability in graft resorption and tissue formation was pinpointed in in situ tissue-engineered heart valves, with a follow-up time of up to 24 months in sheep. This variability was correlated to heterogenous regional cellular repopulation, most likely instigated by region-specific differences in surrounding tissue and hemodynamics. The findings of this research contribute to the mechanistic understanding of in situ tissue engineering using resorbable synthetics, which is necessary to enable rational design of improved grafts, and ensure safe and robust clinical translation.

Divergent composition but similar function of soil food webs of individual plants: plant species and community effects.

Soils are extremely rich in biodiversity, and soil organisms play pivotal roles in supporting terrestrial life, but the role that individual plants and plant communities play in influencing the diversity and functioning of soil food webs remains highly debated. Plants, as primary producers and providers of resources to the soil food web, are of vital importance for the composition, structure, and functioning of soil communities. However, whether natural soil food webs that are completely open to immigration and emigration differ underneath individual plants remains unknown. In a biodiversity restoration experiment we first compared the soil nematode communities of 228 individual plants belonging to eight herbaceous species. We included grass, leguminous, and non-leguminous species. Each individual plant grew intermingled with other species, but all plant species had a different nematode community. Moreover, nematode communities were more similar when plant individuals were growing in the same as compared to different plant communities, and these effects were most apparent for the groups of bacterivorous, carnivorous, and omnivorous nematodes. Subsequently, we analyzed the composition, structure, and functioning of the complete soil food webs of 58 individual plants, belonging to two of the plant species, Lotus corniculatus (Fabaceae) and Plantago lanceolata (Plantaginaceae). We isolated and identified more than 150 taxa/groups of soil organisms. The soil community composition and structure of the entire food webs were influenced both by the species identity of the plant individual and the surrounding plant community. Unexpectedly, plant identity had the strongest effects on decomposing soil organisms, widely believed to be generalist feeders. In contrast, quantitative food web modeling showed that the composition of the plant community influenced nitrogen mineralization under individual plants, but that plant species identity did not affect nitrogen or carbon mineralization or food web stability. Hence, the composition and structure of entire soil food webs vary at the scale of individual plants and are strongly influenced by the species identity of the plant. However, the ecosystem functions these food webs provide are determined by the identity of the entire plant community.

A systems approach to understand microplastic occurrence and variability in Dutch riverine surface waters.

Assessment methods on data quality and environmental variability are lacking for microplastics (MP). Here we assess occurrence and variability of MP number concentrations in two Dutch rivers. Strict QA/QC procedures were applied to identify MP using Fourier-transform infrared (FTIR) microscopy followed by state of the art automated image analysis. For a series of randomly selected, yet ever smaller subareas of filters, we assessed how accurately MP numbers and polymer types are represented during partial filter analysis. Levels of uncertainty were acceptable when analysing 50% of a filter during chemical mapping, and when identifying at least a subset of 50 individual particles with attenuated total reflection (ATR)-FTIR. Applying these guidelines, MP number concentrations between 67 and 11532 MP m-3 were detected in Dutch riverine surface waters. Spatial differences caused MP number concentrations to vary by two orders of magnitude. Temporal differences were lower and induced a maximum variation of one order of magnitude. In total, 26 polymer types were identified, the most common were polyethylene (23%), polypropylene (19.7%) and ethylene propylene diene monomer rubber (18.3%). The highest diversity of polymer types was found for small MPs, whereas MP larger than 1 mm was scarce and almost exclusively made of polyethylene or polypropylene. Virtually all sampling locations revealed MP number concentrations that are considerably below known effect thresholds for anticipated adverse ecological effects.

Modular operation of microfluidic chips for highly parallelized cell culture and liquid dosing via a fluidic circuit board.

Microfluidic systems enable automated and highly parallelized cell culture with low volumes and defined liquid dosing. To achieve this, systems typically integrate all functions into a single, monolithic device as a "one size fits all" solution. However, this approach limits the end users' (re)design flexibility and complicates the addition of new functions to the system. To address this challenge, we propose and demonstrate a modular and standardized plug-and-play fluidic circuit board (FCB) for operating microfluidic building blocks (MFBBs), whereby both the FCB and the MFBBs contain integrated valves. A single FCB can parallelize up to three MFBBs of the same design or operate MFBBs with entirely different architectures. The operation of the MFBBs through the FCB is fully automated and does not incur the cost of an extra external footprint. We use this modular platform to control three microfluidic large-scale integration (mLSI) MFBBs, each of which features 64 microchambers suitable for cell culturing with high spatiotemporal control. We show as a proof of principle that we can culture human umbilical vein endothelial cells (HUVECs) for multiple days in the chambers of this MFBB. Moreover, we also use the same FCB to control an MFBB for liquid dosing with a high dynamic range. Our results demonstrate that MFBBs with different designs can be controlled and combined on a single FCB. Our novel modular approach to operating an automated microfluidic system for parallelized cell culture will enable greater experimental flexibility and facilitate the cooperation of different chips from different labs.

Characterization of picosecond pulse nonlinear propagation in chalcogenide As(2)S(3) fiber.

We characterize the nonlinear propagation of picosecond pulses in chalcogenide As(2)S(3) single-mode fiber using a pump-probe technique. The cross-phase modulation (XPM)-induced sideband broadening and stimulated Raman scattering (SRS)-induced sideband amplification are measured in order to map out the Raman gain spectrum of this glass across the C-band. We extract the Raman response function from the Raman gain spectrum and determine the power and polarization dependence of the SRS. In contrast to previous work using As(2)Se(3) fiber, we find that the As(2)S(3) fiber does not suffer from large two-photon absorption (TPA) in the wavelength range of the telecommunications band. We achieved a 20 dB peak Raman gain at a Stokes shift of 350 cm(-1) in a 205 mm length of As(2)S(3) single-mode fiber. The Raman gain coefficient is estimated to be 4.3x10(-12) m/W and the threshold pump peak power is estimated to be 16.2 W for the 205 mm As(2)S(3) fiber. We also demonstrate that we can infer the dispersion of the As(2)S(3) fiber and justify the Raman response function by comparing simulation and experimental results.

Lactate clearance metrics are not superior to initial lactate in predicting mortality in trauma.

PURPOSE: Despite the availability of different lactate clearance (LC) metrics for clinical use, it remains unknown which metric is superior as a clinical predictor for outcome, particularly in trauma patients. This retrospective study compared four previously described metrics of LC and examined the association between LC and outcome in trauma patients. METHODS: Lactate values of trauma patients admitted to a level I trauma center between 2010 and 2013 were retrieved from patient records. LC was calculated according to Huckabee, Regnier et al., Billeter et al. and Zhang et al. Patients were categorized as isolated traumatic brain injury (TBI), trauma with TBI, and trauma without TBI. The primary study outcome was in-hospital mortality. RESULTS: 367 trauma patients were eligible for LC calculation. Only LC by Zhang et al. [area under the curve (AUC) > 0.622, p < 0.01], and Billeter et al. (AUC > 0.616, p < 0.05) were predictive for mortality in trauma patients with and without TBI. However, both were equally prognostic as the initial lactate value for in-hospital mortality. The prognostic value of initial lactate and lactate clearance for in-hospital mortality were not found to differ between isolated TBI, polytrauma with TBI, and trauma without TBI. CONCLUSIONS: LC metrics based on the methods of Zhang et al. and Billeter et al. predicted mortality in trauma patients, and their prognostic value did not differ between patients with and without TBI. However, initial lactate value was equally prognostic as these LC metrics. Our findings suggest that a single initial lactate measurement may be a more clinically useful tool to predict mortality than the calculation of lactate clearance.

Polymorphic expression of the glutathione S-transferase P1 gene and its susceptibility to Barrett's esophagus and esophageal carcinoma.

Factors determining individual susceptibility to esophageal cancer or premalignant Barrett's epithelium are still largely unclear. An imbalance between phase I drug metabolism [e.g., cytochrome P450 (CYP)] and phase II detoxification [e.g., glutathione S-transferase (GST)] may contribute to the development of these diseases. Polymorphic variants in the CYP1A1 gene were described leading to increased levels of bioactive compounds, whereas polymorphisms in GST genes often resulted in impaired detoxification. We studied the frequencies of polymorphic variants in CYP1A1, GSTP1, GSTT1, and GSTM1 genes in 98 patients with Barrett's epithelium and 34 patients with esophageal cancer. The results were compared with those obtained from 247 healthy blood donors. DNA was extracted, and PCR-RFLP methods were used to detect genetic polymorphisms. Chi2 analysis, Spearman rank correlation, and Wilcoxon rank sum tests were used for statistical evaluation. Polymorphisms in CYP1A1, GSTM1, and GSTT1 occurred at an equal frequency in patients and controls. Occurrence of the polymorphic GSTP1b variant in the GSTP1 gene resulted in a significantly lower GST enzyme activity (P < 0.05), and GSTP1b was found significantly more often in patients with Barrett's epithelium (70%; P < 0.001) and patients with esophageal adenocarcinoma (76%; P = 0.005), as compared to healthy blood donors (41%). In conclusion, presence of the GSTP1b allele leads to lower GST enzyme activity levels and, consequently, impaired detoxification. This most important esophageal GST isoform may, therefore, contribute to the development of Barrett's epithelium and adenocarcinoma.

Towards microfluidic sperm refinement: impedance-based analysis and sorting of sperm cells.

The use of high quality semen for artificial insemination in the livestock industry is essential for successful outcome. Insemination using semen with a high number of sperm cells containing morphological defects has a negative impact on fertilization outcome. Therefore, semen with a high number of these abnormal cells is discarded in order to maintain high fertilization potential, resulting in the loss of a large number of morphologically normal sperm cells (up to 70-80% of original sample). A commonly occurring morphological sperm anomaly is the cytoplasmic droplet on the sperm flagella. Currently, no techniques are available to extract morphologically normal sperm cells from rejected samples. Therefore, we aim to develop a microfluidic setup which is able to detect and sort morphologically normal sperm cells label-free and non-invasively. In a proof-of-concept experiment, differential impedance measurements were used to detect the presence of cytoplasmic droplets on sperm flagella, which was quantified by calculating the area under the curve (AUC) of the corresponding impedance peaks. A receiver operating characteristic curve of this electrical analysis method showed the good predictive power of this analysis method (AUC value of 0.85). Furthermore, we developed a label-free cell sorting system using LabVIEW, which is capable of sorting sperm cells based on impedance. In a proof-of-concept experiment, sperm cells and 3 µm beads were sorted label-free and non-invasively using impedance detection and dielectrophoresis sorting. These experiments present our first attempt to perform sperm refinement using microfluidic technology.

Regulation of the CRABP-I gene during mouse embryogenesis.

The cellular retinoic acid binding protein type I (CRABP-I) shows a highly specific expression pattern during mouse embryonic development. The tissues that express CRABP-I, i.e. the central nervous system (CNS), neural crest, branchial arches, limb bud and frontonasal mass, coincide with those that are most sensitive to unphysiological retinoic acid (RA) concentrations. We have investigated the transcriptional elements that are responsible for the spatiotemporal regulation of CRABP-I expression in the mouse embryo. We show here that a 16 kb fragment harbours all the elements needed for the correct spatiotemporal expression pattern. Upon further dissection of this fragment we have found that expression in the CNS is driven by elements in the upstream region of the gene, while expression in mesenchymal and neural crest tissue is regulated via element(s) located downstream of exon II of the gene. Two distinct fragments in the upstream region are required for expression in the CNS, as neither of these fragments alone is able to drive correct expression of a reporter gene in transgenic mice. DNAseI footprinting analysis of the two upstream fragments revealed the presence of a number of protected elements. One of these regulatory elements has the hallmarks of an RA response element, suggesting that CRABP-I expression in neural tissue can be directly modulated by RA via the RARs/RXRs.

Differential effects of interleukin 1-alpha (IL-1 alpha) or tumor necrosis factor-alpha (TNF-alpha) on motility of human melanoma cell lines on fibronectin.

Interleukin-1 alpha (IL-1 alpha) and tumor necrosis factor-alpha (TNF-alpha) induce a motogenic response in a number of benign and malignant cells. We examined the chemokinetic effects of these cytokines on the cell migration of four melanoma cell lines on fibronectin using modified Boyden chambers and video-time lapse analysis. Flow cytometry analysis of IL-1 receptors, TNF receptors, and shifts in beta 1 integrin expression were correlated with the effects of these cytokines on cell migration on fibronectin. The four melanoma cell lines exhibited heterogeneous expression of types I and II IL-1 receptors as well as p60 TNF receptors. Scant p80 TNF receptor expression was detected on only one cell line. Three of four melanoma cell lines demonstrated type I IL-1 receptors by Western blotting. IL-1 alpha and TNF-alpha induced heterogeneous modulation of beta 1 integrin expression in the four melanoma cell lines tested; downward shift of the alpha 2, alpha 3, alpha 4, and beta 1 integrin subunits was detected among three of the melanoma cell lines as were upward shifts of the alpha 4, alpha 5, and alpha 6 integrin subunits among three of the melanoma cell lines. IL-1 alpha and TNF-alpha induced enhanced migration on fibronectin in one of the melanoma cell lines and were related to an upward shift in the alpha 4 and alpha 5 integrin subunit expression. Taken together, the findings indicate that expression of a particular receptor for IL-1 or TNF does not necessarily signal a motogenic response in melanoma cells, but induces heterogeneous shifts in beta 1 integrin expression. However, upregulation in alpha 4 and alpha 5 integrin subunits appears to relate to enhanced migration on fibronectin.

A putative mechanism for bog patterning.

The surface of bogs commonly shows various spatial vegetation patterning. Typical are "string patterns" consisting of regular densely vegetated bands oriented perpendicular to the slope. Here, we report on regular "maze patterns" on flat ground, consisting of bands densely vegetated by vascular plants in a more sparsely vegetated matrix of nonvascular plant communities. We present a model reproducing these maze and string patterns, describing how nutrient-limited vascular plants are controlled by, and in turn control, both hydrology and solute transport. We propose that the patterns are self-organized and originate from a nutrient accumulation mechanism. In the model, this is caused by the convective transport of nutrients in the groundwater toward areas with higher vascular plant biomass, driven by differences in transpiration rate. In a numerical bifurcation analysis we show how the maze patterns originate from the spatially homogeneous equilibrium and how this is affected by changes in rainfall, nutrient input, and plant properties. Our results confirm earlier model results, showing that redistribution of a limiting resource may lead to fine-scale facilitative and coarse-scale competitive plant interactions in different ecosystems. Self-organization in ecosystems may be a more general phenomenon than previously thought, which can be mechanistically linked to scale-dependent facilitation and competition.

Mycosis fungoides: disease evolution and prognosis of 309 Dutch patients.

OBJECTIVES: To determine the disease course of Dutch patients with mycosis fungoides and to define factors related to disease progression and survival. DESIGN: A multicenter, 13-year, retrospective cohort analysis. SETTING: Eight dermatology departments collaborating in the Dutch Cutaneous Lymphoma Group. PATIENTS: Three hundred nine patients with mycosis fungoides registered between October 1985 and May 1997, including 89 patients with limited patches or plaques (stage Ia), 135 with generalized patches or plaques (stage Ib), 46 with skin tumors (stage Ic), 18 with enlarged but uninvolved lymph nodes (stage II), 18 with lymph node involvement (stage III), and 3 with visceral involvement (stage IV). MAIN OUTCOME MEASURES: Response to initial treatment, sustained complete remission, actuarial disease progression, and overall and disease-specific survival per clinical stage. RESULTS: The median follow-up was 62 months (range, 1-113 months). For the entire group, the actuarial overall and disease-specific survival was 80% and 89% at 5 years, and 57% and 75% at 10 years, respectively. The actuarial 5-year disease-specific survival of patients with stage Ia, Ib, and Ic disease was 100%, 96%, and 80%, respectively, and only 40% for patients with stage III disease. Using multivariate analysis, the presence of extracutaneous disease, the type and extent of skin involvement, the response to initial treatment, and the presence of follicular mucinosis were independently associated with higher disease progression and mortality rates. The calculated risks of disease progression at 5 and 10 years gradually increased from 4% to 10% for those with stage Ia disease, from 21% to 39% for those with stage Ib disease, and from 32% to 60% for those with stage Ic disease; for those with stage III disease, the risk remained at 70% at 5 and 10 years. The overall risk of disease progression at 5 and 10 years was 24% and 38%, respectively, for the total study group. CONCLUSION: At least within the first 10 years after diagnosis, disease progression and mycosis fungoides-related mortality occur in only a subset of patients generally presenting with advanced disease.

Differential effect of magnesium and calcium on integrin-mediated melanoma cell migration on type IV collagen and fibronectin.

We characterized the effects of extracellular Mg2+ and Ca2+ on the regulation of integrin-mediated cell migration of melanoma cells on type IV collagen and fibronectin. Melanoma cell motility was studied using transmembrane migration in modified Boyden chambers and time-lapse video image analysis. Increasing Mg2+ or Ca2+ ion concentration from 0.1 to 10 mM produces distinct effects on melanoma cell migration on type IV collagen. Increasing Mg2+ ion concentration increased cell migration to a maximum at 5 mM, followed by a decrease at 10 mM. In contrast, Ca2+ alone did not support cell migration on this substrate. Combinations of both cations indicate that Ca2+ decreases cell migration in the presence of Mg2+. However, as opposed to the findings on collagen, peak migration on fibronectin was observed at 1 mM and Ca2+ alone was able to support migration on fibronectin. The Mg(2+)-enhanced migration was inhibited by function-blocking monoclonal antibodies anti-alpha 2 or anti-beta 1 integrin subunit on the type IV collagen and anti-alpha 5 and anti-beta 1 on fibronectin. Taken together, the data indicate that Mg2+ promotes the integrin-mediated cell migration, whereas Ca2+ has the opposite effect. The Ca2+ and Mg2+ concentration in the tumour extracellular microenvironment may modulate integrin-mediated functions and melanoma metastasis.

Role of alpha 3 beta 1 and alpha 2 beta 1 integrins in melanoma cell migration.

Recent findings indicate that variable expression of beta 1 integrins may play a role in differential melanoma cell motility. Primary melanoma (PM) and metastatic melanoma (MM) cultures, derived from the same patient, were tested for their beta 1, alpha 2, alpha 3 and alpha 6 integrin subunit expression and cell migration on type IV collagen (CN IV) or laminin (LN). The MM cell line expressed markedly increased levels of the beta 1, alpha 2 and alpha 3, but not alpha 6 subunit compared to the PM cell line. The MM cell migration rate was significantly higher than that of the PM cell line on LN- or CN IV-coated substrates. Furthermore, the cell migration rate of both lines was significantly higher (p < 0.001) on these substrates than on the control substrates. The MM and PM cell migration was significantly inhibited by function-blocking anti-beta 1 and anti-alpha 3 MAbs, but not by the anti-alpha 6 MAb tested. In contrast, the anti-alpha 2 MAb significantly inhibited MM but not PM cell migration. These data show that the alpha 3 subunit plays a significant role in melanoma cell motility on CN IV and LN and that the alpha 2 subunit has a significant contribution to the motility of the MM cell line.

Skin equivalent: an attractive model to evaluate early melanoma metastasis.

The growth patterns and morphological phenotype of four human melanoma cell lines with different metastatic potentials were investigated in submerged and in air-exposed (skin equivalent) keratinocyte-melanoma cell co-cultures. In contrast to the submerged co-cultures, all four cell lines formed sharply demarcated tumour cell nests within the epidermal compartment of the skin equivalent model, with the morphology highly mimicking the in vivo situation. Differences among the melanoma cell lines tested were observed with respect to the number of clusters formed and the ability to exhibit invasive growth. Only the two metastatic cell lines were able to invade the dermal compartment. Screening of cellular adhesion molecules revealed that the expression patterns in different cell lines were heterogeneous and remained unchanged during the whole culture period, irrespective of whether the melanoma cells were located in the epidermal or dermal compartment. A correlation was found between expression of a lower number of different cellular adhesion molecules and the ability to acquire invasive growth capability. Our results indicate that melanoma cells exhibit a heterogeneous growth behaviour when co-cultured with human keratinocytes, and the air-exposed skin equivalent model was shown to be suitable for studying differences in growth patterns and potential invasive behaviour.

Characterization of interleukin-1 alpha-induced melanoma cell motility: inhibition by type I and type II receptor-blocking monoclonal antibodies.

Interleukin-1 alpha (IL-1 alpha) induces cell motility in a variety of benign cell types and in some but not all malignant cell lines in vitro. This study characterizes the IL-1 alpha-induced motility of an aggressive human melanoma cell line that expresses both type I and type II IL-1 receptors. We tested the effect of monoclonal antibodies including function-blocking moAbs against the type I and type II IL-1 receptors on melanoma cell motility to determine which receptor is involved in signal transduction of IL-1 alpha-induced melanoma cell motility. IL-1 alpha significantly increases MM-RU melanoma cell migration in a dose-dependent manner using modified Boyden chamber assays at concentrations 10 to 100 times less than concentrations that significantly inhibit cell growth. Computer-assisted time-lapse image analysis reveals that the motility is inhibited in a dose-dependent manner by neutralizing antibodies against IL-1 alpha. Function-blocking monoclonal antibodies against either type I or type II IL-1 receptors show a significant inhibition of cytokine-induced enhanced cell migration. When both the anti-IL-1 receptor antibodies are added together, the motility-response is completely blocked to control levels. Taken together the data indicate that the IL-1 alpha-induced motility of MM-RU melanoma cells is mediated through both type I and type II IL-1 receptors. The significant inhibition of motility by neutralizing IL-1 alpha or blocking either one or both of the IL-1 receptors indicates an integration of IL-1-induced signals in the induction of melanoma cell migration.

The ergonomics of flight management systems: fixing holes in the cockpit certification net.

Recent air traffic control regulations mandate the installation of computer-based flight management systems in airliners across Europe. Integrating and certifying add-on cockpit systems is a long and costly process, which in its current form cannot meaningfully address ergonomics aspects. Two levels of problems occur: add-on systems carry many "classic" HCI failures, which could easily be addressed with modified certification requirements. Further, adding new technology changes practice, creates new skill and knowledge demands and produces new forms of error, which are more difficult to assess in advance. However, one innovative certification approach for add-on cockpit systems, based on the use of a representative population of user pilots, was found to be promising. This method minimizes the subjective bias of individual pilots in addition to defining pass/fail criteria in an operational environment.

[Exogenous ochronosis, a little-known side effect of hydroquinone-containing ointments]. / Exogene ochronosis, een weinig bekende bijwerking van hydrochinon-bevattende crèmes.

Two patients with exogenous ochronosis, an unfamiliar side effect of hydroquinone-containing bleaching creams, are presented. This disorder is characterized by progressive darkening of the area to which the cream is applied. Histologically there is deposition of yellow-brown pigment in the dermis, in addition to degeneration of collagen and elastic fibres. The chemical composition of the ochronotic material and the pathogenesis of this paradoxical effect of hydroquinone are unknown. Hydroquinone containing creams should not be used for longer than two years. If there is no improvement within six months, application should be discontinued.