NCO-sP(EO-stat-PO) Coatings on Gold Sensors—a QCM Study of Hemocompatibility

The reliability of implantable blood sensors is often hampered by unspecific adsorption of plasma proteins and blood cells. This not only leads to a loss of sensor signal over time, but can also result in undesired host vs. graft reactions. Within this study we evaluated the hemocompatibility of isocyanate conjugated star shaped polytheylene oxide—polypropylene oxide co-polymers NCO-sP(EO-stat-PO) when applied to gold surfaces as an auspicious coating material for gold sputtered blood contacting sensors. Quartz crystal microbalance (QCM) sensors were coated with ultrathin NCO-sP(EO-stat-PO) films and compared with uncoated gold sensors. Protein resistance was assessed by QCM measurements with fibrinogen solution and platelet poor plasma (PPP), followed by quantification of fibrinogen adsorption. Hemocompatibility was tested by incubation with human platelet rich plasma (PRP). Thrombin antithrombin-III complex (TAT), β-thromboglobulin (β-TG) and platelet factor 4 (PF4) were used as coagulation activation markers. Furthermore, scanning electron microscopy (SEM) was used to visualize platelet adhesion to the sensor surfaces. Compared to uncoated gold sensors, NCO-sP(EO-stat-PO) coated sensors revealed significant better resistance against protein adsorption, lower TAT generation and a lower amount of adherent platelets. Moreover, coating with ultrathin NCO-sP(EO-stat-PO) films creates a cell resistant hemocompatible surface on gold that increases the chance of prolonged sensor functionality and can easily be modified with specific receptor molecules

Comparative analysis of selected exhaled breath biomarkers obtained with two different temperature-controlled devices

<p>Abstract</p> <p>Background</p> <p>The collection of exhaled breath condensate (EBC) is a suitable and non-invasive method for evaluation of airway inflammation. Several studies indicate that the composition of the condensate and the recovery of biomarkers are affected by physical characteristics of the condensing device and collecting circumstances. Additionally, there is an apparent influence of the condensing temperature, and often the level of detection of the assay is a limiting factor. The ECoScreen2 device is a new, partly single-use disposable system designed for studying different lung compartments.</p> <p>Methods</p> <p>EBC samples were collected from 16 healthy non-smokers by using the two commercially available devices ECoScreen2 and ECoScreen at a controlled temperature of -20°C. EBC volume, pH, NOx, LTB₄, PGE₂, 8-isoprostane and cys-LTs were determined.</p> <p>Results</p> <p>EBC collected with ECoScreen2 was less acidic compared to ECoScreen. ECoScreen2 was superior concerning condensate volume and detection of biomarkers, as more samples were above the detection limit (LTB₄and PGE₂) or showed higher concentrations (8-isoprostane). However, NOx was detected only in EBC sampled by ECoScreen.</p> <p>Conclusion</p> <p>ECoScreen2 in combination with mediator specific enzyme immunoassays may be suitable for measurement of different biomarkers. Using this equipment, patterns of markers can be assessed that are likely to reflect the complex pathophysiological processes in inflammatory respiratory disease.</p

The benzene metabolite para-benzoquinone is genotoxic in human, phorbol-12-acetate-13-myristate induced, peripheral blood mononuclear cells at low concentrations

Benzene is one of the most prominent occupational and environmental pollutants. The substance is a proven human carcinogen that induces hematologic malignancies in humans, probably at even low doses. Yet knowledge of the mechanisms leading to benzene-induced carcinogenesis is still incomplete. Benzene itself is not genotoxic. The generation of carcinogenic metabolites involves the production of oxidized intermediates such as catechol, hydroquinone and para-benzoquinone (p-BQ) in the liver. Further activation to the ultimate carcinogenic intermediates is most probably catalyzed by myeloperoxidase (MPO). Yet the products of the MPO pathway have not been identified. If an oxidized benzene metabolite such as p-BQ was actually the precursor for the ultimate carcinogenic benzene metabolite and further activation proceeds via MPO mediated reactions, it should be possible to activate p-BQ to a genotoxic compound in vitro. We tested this hypothesis with phorbol-12-acetate-13-myristate (PMA) activated peripheral blood cells exposed to p-BQ, using the cytokinesis-block micronucleus test. Addition of 20–28 ng/ml PMA caused a significant increase of micronuclei at low and non-cytotoxic p-BQ concentrations between 0.04 and 0.2 μg/ml (0.37–1.85 μM). Thus with PMA or p-BQ alone no reproducible elevation of micronuclei was seen up to toxic concentrations. PMA and p-BQ induce micronuclei when administered jointly. Our results add further support to the hypothesis that MPO is a key enzyme in the activation of benzene

Occupational health hazards of street cleaners – a literature review considering prevention practices at the workplace

Street cleaning is an integral part of the solid waste management system. There are different ways to achieve clean streets depending on the availability of equipment, the type and magnitude of dirt, the surface conditions encountered or traffic conditions. In general, hand sweeping by an individual worker or a group, hose flushing, or machine sweeping or flushing are applied. In order to obtain information about the occurrence and relevance of occupational health hazards of street cleaners, the current international literature, as well as corresponding German regulations, were reviewed and evaluated. Street cleaning includes a variety of health hazards for employees. These can be subdivided into effects of occupational tasks and effects of working conditions such as weather or road traffic. The hazards result from physical, chemical and biological exposures, but may also be due to physiological and psychological burden or inadequate safety aspects. The most commonly reported work-related complaints are musculoskeletal and respiratory disorders, cuts, slips, and road traffic accidents. In developing countries, street cleaners seem to be still heavily exposed to dust and, in most cases, no suitable protective measures are available. Especially in industrialized countries there exist a number of standards and recommendations for waste workers that aim to reduce their occupational health impacts