Early appearance of 2, 3-butanediol in acute myocardial infarction. A new marker for ischaemia?

In 28 patients with acute myocardial infarction, the release pattern of 2, 3-butanediol (BD), a product of intermediary metabolism, and creatine kinase activity (CK) in blood were compared. Whereas CKat entry was low in all patients, the BD level was elevated in 18 (64%). However, BD returned to normal levels during the next 24 h whereas CK increased. The BD level at entry did not allow differentiation between patients with transmural or non-transmural infarction; it was independent of clinical findings and biochemical parameters. We suggest that, in patients with acute myocardial infarction, elevated levels of BD originates from myo-cardial metabolism. Whether it reflects ongoing ischaemia or reperfusion of the infarcted area remains unresolve

2,3-butanediol in experimental myocardial ischaemia in pigs

To investigate the role of 2,3-butanediol in myocardial ischaemia we analysed this compound in pig's myocardium and blood. Ischaemia was induced by ligation of a coronary artery. In the first study we found significantly higher levels of 2,3-butanediol in the homogenate of ischaemic myocardium than in non-ischaemic myocardium. The lactate concentration was also significantly elevated. In the second study, where ischaemia was similarly induced, and where reperfusion was achieved by re-opening the ligated coronary artery after 20 min, 2,3-butanediol in peripheral blood was found to increase significantly. In the pigs in which the coronary artery was not re-opened, the 2,3-butanediol level in peripheral blood was unchanged. We conclude that in pigs' anaerobic myocardia accumulation of 2,3-butanediol occurs; if the myocardium is reperfused this metabolite also appears in the bloo

Defining a Novel Role for the Coxsackievirus and Adenovirus Receptor in Human Adenovirus Serotype 5 Transduction In Vitro in the Presence of Mouse Serum

Human adenoviral serotype 5 (HAdV-5) vectors have predominantly hepatic tropism when delivered intravascularly, resulting in immune activation and toxicity. Coagulation FX binding to HAdV-5 mediates liver transduction and provides protection from virion neutralisation in mice. FX is dispensable for liver transduction in mice lacking IgM antibodies or complement, suggesting alternative transduction pathways exist. To identify novel factor(s) mediating HAdV-5 FX-independent entry, we investigated HAdV-5 transduction in vitro in the presence of serum from immunocompetent C57BL/6 or immunocompromised mice lacking IgM antibodies (Rag 2-/- and NSG). Sera from all three mouse strains enhanced HAdV-5 transduction of A549 cells. While inhibition of HAdV-5:FX interaction with X-bp inhibited transduction in the presence of C57BL/6 serum, it had negligible effect on the enhanced transduction observed in the presence of Rag 2-/- or NSG serum. Rag 2-/- serum also enhanced transduction of the FX-binding deficient AdT*. Interestingly, Rag 2-/- serum enhanced HAdV-5 transduction in a FX-independent manner in CHO-CAR and SKOV3-CAR cells. Additionally, blockade of CAR with soluble HAdV-5 fiber knob inhibited mouse serum-enhanced transduction in A549 cells, suggesting a potential role for CAR. Transduction of HAdV-5 KO1 and HAdV-5/F35 (CAR-binding deficient) in the presence of Rag 2-/- serum was equivalent to that of HAdV-5, indicating that direct interaction between HAdV-5 and CAR is not required. These data suggest that FX may protect HAdV-5 from neutralization but has minimal contribution to HAdV-5 transduction in the presence of immunocompromised mouse serum. Alternatively, transduction occurs via an unidentified mouse serum protein capable of bridging HAdV-5 to CAR

Label-free protein detection based on the heat-transfer method-a case study with the peanut allergen Ara h 1 and aptamer-based synthetic receptors

© 2015 American Chemical Society. Aptamers are an emerging class of molecules that, because of the development of the systematic evolution of ligands by exponential enrichment (SELEX) process, can recognize virtually every target ranging from ions, to proteins, and even whole cells. Although there are many techniques capable of detecting template molecules with aptamer-based systems with high specificity and selectivity, they lack the possibility of integrating them into a compact and portable biosensor setup. Therefore, we will present the heat-transfer method (HTM) as an interesting alternative because this offers detection in a fast and low-cost manner and has the possibility of performing experiments with a fully integrated device. This concept has been demonstrated for a variety of applications including DNA mutation analysis and screening of cancer cells. To the best our knowledge, this is the first report on HTM-based detection of proteins, in this case specifically with aptamer-type receptors. For proof-of-principle purposes, measurements will be performed with the peanut allergen Ara h 1 and results indicate detection limits in the lower nanomolar regime in buffer liquid. As a first proof-of-application, spiked Ara h 1 solutions will be studied in a food matrix of dissolved peanut butter. Reference experiments with the quartz-crystal microbalance will allow for an estimate of the areal density of aptamer molecules on the sensor-chip surface

Compact fixturing based on magneto-rheological fluids for aeronautic stringers milling

The paper explains the compact fixturing based on magneto-rheological (MR) fluids that have been designed and validated for aeronautic stringers milling. The MR fluid based tooling developed is flexible and reconfigurable as it can be adapted to different profile's lengths and sections and it is able to fix compliant workpieces without reference faces as the MR fluid adapts to the outer shape of each profile. The MR fluid based tooling is suitable to hold non-magnetic materials such as aluminum and also materials that do not admit high clamping forces, such as titanium, because they will appear as deformation after machining due to the memory effect of titanium. The MR fluid based tooling has been tested in a machine environment under real machining conditions and promising results have been obtained

Formation and electrical characterization of black lipid membranes in porous filter materials

Black lipid membranes (BLMs) are planar lipid bilayers that can be formed in porous supports such as filters. A BLM as a biomimetic membrane has important applications in, for instance, biosensing and drug-permeability assays. In the present study, BLMs were formed in the pores of three different filters to investigate their ability to support the formation of a high-quality lipid bilayer. Poly (vinylidene fluoride) (PVDF), poly(acrylonitrile) (PAN), and polypropylene/polyethylene (PP/PE) filters were utilized as filter supports, and the bilayer formation was monitored in situ by capacitance measurements. The maximum capacitance was obtained for PVDF (5.34 μF · cm−2) versus PP/PE and PAN (2.95 and 0.91 μF · cm−2, respectively). Additionally, BLM leakage current measurements by wave deviation provided consistent results. Thickness and compactness of the bilayers were evaluated using pore forming protein (ClyA) insertion. The results show that PVDF with the highest porosity level was the most suitable support for BLM formation. The optimal thickness for the BLM in PVDF was 3–5 nm, where the most efficient protein insertion took place, in comparison with other filters.info:eu-repo/semantics/publishe

Improving the sensitivity of the heat-transfer method (HTM) for cancer cell detection with optimized sensor chips

© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. In this article, we increased the sensitivity of the heat-transfer method (HTM) for the detection of breast cancer cells (ZR-75-1 cells, see figure) in phosphate buffered saline (PBS). The effect of small technological changes on the limit of detection (LoD) of the methodology was examined. To this extent, polished aluminum substrates with a mirror finish were used, replacing the unpolished chips used in previous studies. These chips were coated with a polyurethane layer and imprinted for the target cell type, creating a so-called surface imprinted-polymer (SIP). Binding of target cells to the SIP resulted in an increase of the thermal resistance at the solid-liquid interface under study. Background thermal resistance measurements were performed with polished and unpolished aluminum substrates. In addition, the effect of using silver paste as thermal coupling between the aluminum chip and the copper heat provider was analyzed. The results of these experiments reveal that optimal thermal contact is achieved when directly coupling the copper heat provider to the polished side of the aluminum substrate as evidenced by a decrease in the baseline thermal resistance. In addition, noise levels on the heat-transfer resistance (Rth) signal decreased by a factor in the optimal configuration. Dose-response curves were obtained using the optimized methodology and were compared with results obtained with the original substrates. These quantitative experiments demonstrated an improvement of the LoD by approximately thirty percent. ZR-75-1 cells applied onto a home-made rubber stamp.status: publishe