Intravital FRET: Probing Cellular and Tissue Function in Vivo

The development of intravital Förster Resonance Energy Transfer (FRET) is required to probe cellular and tissue function in the natural context: the living organism. Only in this way can biomedicine truly comprehend pathogenesis and develop effective therapeutic strategies. Here we demonstrate and discuss the advantages and pitfalls of two strategies to quantify FRET in vivo—ratiometrically and time-resolved by fluorescence lifetime imaging—and show their concrete application in the context of neuroinflammation in adult mice.     

Alpha‐Synuclein Binds to the Inner Membrane of Mitochondria in an α‐Helical Conformation

The human alpha‐Synuclein (αS) protein is of significant interest because of its association with Parkinson's disease and related neurodegenerative disorders. The intrinsically disordered protein (140 amino acids) is characterized by the absence of a well‐defined structure in solution. It displays remarkable conformational flexibility upon macromolecular interactions, and can associate with mitochondrial membranes. Site‐directed spin‐labeling in combination with electron paramagnetic resonance spectroscopy enabled us to study the local binding properties of αS on artificial membranes (mimicking the inner and outer mitochondrial membranes), and to evaluate the importance of cardiolipin in this interaction. With pulsed, twofrequency, double‐electron electron paramagnetic resonance (DEER) approaches, we examined, to the best of our knowledge for the first time, the conformation of αS bound to isolated mitochondria.     

Heavy metal exposure in patients suffering from electromagnetic hypersensitivity

Background

Risks from electromagnetic devices are of considerable concern. Electrohypersensitive (EHS) persons attribute a variety of rather unspecific symptoms to the exposure to electromagnetic fields. The pathophysiology of EHS is unknown and therapy remains a challenge.

Objectives

Heavy metal load has been discussed as a potential factor in the symptomatology of EHS patients. The main objective of the study was to test the hypothesis of a link between EHS and heavy metal exposure.

Methods

We measured lead, mercury and cadmium concentrations in the blood of 132 patients (n = 42 males and n = 90 females) and 101 controls (n = 34 males and n = 67 females).

Results

Our results show that heavy metal load is of no concern in most cases of EHS but might play a role in exceptional cases.

Conclusions

The data do not support the general advice to heavy metal detoxification in EHS.     

Influence of atmospheric plasma-induced graft polymerization of DADMAC into cotton on dyeing with acid dyes

The primary objective of this work was to generate dyes sites in cotton fiber for acid dyes via free radical graft polymerization of diallyldimethylammonium chloride (DADMAC), to confer cationized cotton, and evaluate the dyeability of the cationized cotton toward acid dyes, which is unprecedented. Plasma-induced graft polymerization of DADMAC on cotton, using different plasma conditions, followed by dyeing with different acid dyes was studied. The color yield of dyed cotton was evaluated using K/S. Light fastness, color change, and staining following accelerated washing cycles were carried out to evaluate the effectiveness of cotton cationization. Cross-section dyed cotton was studied using scanning electron microscopy and showed deep dyeing of acid dyes into cotton fibers. This approach resulted in significant dye uptake into the fibers and considerably reduced the need for effluent treatment.     

Influence of Compaction Conditions on the Foamability of AlSi8Mg4 Alloy

Aluminum AlSi8Mg4 alloy foams were produced by the powder compact foaming route using different parameters for the uniaxial powder compaction step. Compaction time, pressure, and temperature were varied and were found to influence both the density of the foamable precursor and the peak expansion reached during foaming. While peak expansion cannot be related to any single pressing parameter alone in a simple way, a clear dependence of expansion on the precursor density was found. Densification to a relative density between 97.5 and 99 pct yielded volume expansions of the foam up to 880 pct. Lower densities result in weaker foaming, due to insufficient encapsulation of the blowing agent; in addition, we were surprised to find that higher densification also has an adverse effect on peak expansion, most likely due to the elimination of nucleation centers or the effect of entrapped compressed air. Precursor microstructures were analyzed to identify the mechanisms leading to the observed density dependence of expansion.     

Magneto-optical current sensor by domain wall motion inorthoferrites

A brief review of the latest developments on optical current measurements based on the Faraday effect is presented. In all existing magneto-optical current transformers, the main measured parameter is the polarization state of the light transmitted by a sensor element. A new transformer is described by means of new results concerning the domain wall excitation. The measured parameter is the geometrical position of the boundary between domains with opposite magnetizations. In a wide frequency band, including DC currents, the measurement results are a linear function of the measured current. They are not affected by temperature changes and mechanical factors     

Mycophenolate mofetil: therapeutic applications in kidney transplantation and immune-mediated renal disease

The inhibition of arylamine N-acetyltransferase (NAT) activity by ibuprofen was determined in a human colon tumour (adenocarcinoma) cell line. Two assay systems were employed, one with cellular cytosols (9000 g supernatant) and the other with intact colon tumour cell suspensions. The NAT activity in a human colon tumour cell line was inhibited by ibuprofen in a dose-dependent manner in both systems, i.e. the greater the concentration of ibuprofen in the reaction, the greater the inhibition of NAT activities in both systems. The data also indicated that ibuprofen decreases the apparent Km and Vmax of NAT enzyme from human colon tumour cells in both systems examined. This report is the first demonstration to show that ibuprofen affects human colon tumour cell NAT activity.     

Exotic species in Lake Champlain

The Lake Champlain basin contains substantially fewer exotic species (N = 48) than the Great Lakes (N > 180), in part due to its isolation from commercial traffic. Exotic species have been introduced by authorized and unauthorized stocking, bait buckets, use of ornamental plants, and through the Champlain and Chambly canals that link the lake to the Hudson River, Mohawk River, Erie Canal, and the Great Lakes. Several species, such as water chestnut and zebra mussels, have had severe ecological, economic, and nuisance effects. The rate of appearance of new species increased in the 1990s, potentially as a result of increasing activity in the basin, improved water quality in the Champlain Canal, and increased sampling. Efforts to slow the introduction of new species have focused on public education and legislation to reduce bait bucket introductions and quarantine undesirable plants; however, the major remaining vector for introductions is the Champlain Canal. An estimated 20 species have entered the lake via canals, of which at least 12 used the Champlain Canal, and numerous species in the connected drainage systems could still enter via this route; some are already in the Erie Canal. Most recently (2008), the Asian clam was discovered two locks below Lake Champlain. The Lake Champlain canals also function as a conduit for exotic species exchange between the Hudson River, St. Lawrence River, and Great Lakes. The potential for future introductions could be reduced by a biological barrier on the Champlain Canal, and additional emphasis on public education.