Electroexcitation of nucleon resonances at Q^2=0.65 GeV/c^2 from a combined analysis of single- and double-pion electroproduction data

Data on single- and double-charged pion electroproduction off protons are successfully described in the second and third nucleon resonance regions with common N* photocouplings. The analysis was carried out using separate isobar models for both reactions. From the combined analysis of two exclusive channels, the gamma* p --> N*+ helicity amplitudes are obtained for the resonances P11(1440), D13(1520), S31(1620), S11(1650), F15(1680), D33(1700), D13(1700), and P13(1720) at Q2=0.65 GeV/c^2.Comment: 12 pages, 12 figures (eps), Published in PHYSICAL REVIEW C 72, 045201 (2005

Statin‐induced myopathy: Translational studies from preclinical to clinical evidence

Statins are the most prescribed and effective drugs to treat cardiovascular diseases (CVD). Nevertheless, these drugs can be responsible for skeletal muscle toxicity which leads to reduced compliance. The discontinuation of therapy increases the incidence of CVD. Thus, it is essential to assess the risk. In fact, many studies have been performed at preclinical and clinical level to investigate pathophysiological mechanisms and clinical implications of statin myotoxicity. Consequently, new toxicological aspects and new biomarkers have arisen. Indeed, these drugs may affect gene transcription and ion transport and contribute to muscle function impairment. Identifying a marker of toxicity is important to prevent or to cure statin induced myopathy while assuring the right therapy for hypercholesterolemia and counteracting CVD. In this review we focused on the mechanisms of muscle damage discovered in preclinical and clinical studies and high-lighted the pathological situations in which statin therapy should be avoided. In this context, preventive or substitutive therapies should also be evaluated

A novel human aquaporin-4 splice variant exhibits a dominant-negative activity: a new mechanism to regulate water permeability.

Two major isoforms of aquaporin-4 (AQP4) have been described in human tissue. Here we report the identification and functional analysis of an alternatively spliced transcript of human AQP4, AQP4-Δ4, that lacks exon 4. In transfected cells AQP4-Δ4 is mainly retained in the endoplasmic reticulum and shows no water transport properties. When AQP4-Δ4 is transfected into cells stably expressing functional AQP4, the surface expression of the full-length protein is reduced. Furthermore, the water transport activity of the cotransfectants is diminished in comparison to transfectants expressing only AQP4. The observed down-regulation of both the expression and water channel activity of AQP4 is likely to originate from a dominant-negative effect caused by heterodimerization between AQP4 and AQP4-Δ4, which was detected in coimmunoprecipitation studies. In skeletal muscles, AQP4-Δ4 mRNA expression inversely correlates with the level of AQP4 protein and is physiologically associated with different types of skeletal muscles. The expression of AQP4-Δ4 may represent a new regulatory mechanism through which the cell-surface expression and therefore the activity of AQP4 can be physiologically modulated

Directed growth and fusion of membrane-wall microdomains requires CASP-mediated inhibition and displacement of secretory foci.

Casparian strips (CS) are aligned bands of lignin-impregnated cell walls, building an extracellular diffusion barrier in roots. Their structure profoundly differs from tight junctions (TJ), analogous structures in animals. Nonetheless, CS membrane domain (CSD) proteins 1-5 (CASP1-5) are homologues of occludins, TJ components. CASP-marked membranes display cell wall (matrix) adhesion and membrane protein exclusion. A full CASP knock-out now reveals CASPs are not needed for localized lignification, since correctly positioned lignin microdomains still form in the mutant. Ultra-structurally, however, these microdomains are disorganized, showing excessive cell wall growth, lack of exclusion zone and matrix adhesion, and impaired exocyst dynamics. Proximity-labelling identifies a Rab-GTPase subfamily, known exocyst activators, as potential CASP-interactors and demonstrate their localization and function at the CSD. We propose that CASP microdomains displace initial secretory foci by excluding vesicle tethering factors, thereby ensuring rapid fusion of microdomains into a membrane-cell wall band that seals the extracellular space

Effects of the ionizing radiation disinfection treatment on historical leather

Microorganisms often cause significant damage on historical objects. The archive or library materials as well as textile or leather artifacts suffer serious attacks that need appropriate care treatments. Several biocide processes have been implemented but often their application does not preserve the material of the good. The objective of this work is the disinfection through ionizing radiation of leather wallpaper from the museum building Palazzo Chigi in Ariccia (Rome, Italy). The controlled sterilization treatments were carried out using X-ray beams to eliminate the microorganisms present on the leather and maintaining unchanged the properties of the constituent material. Some fragments of decorated leather wallpaper, dating back to the 1700s, were irradiated with X-rays up to 5,000 Gy. The amount of microorganisms was evaluated by microbiological analysis before and after X-ray irradiation treatments to identify the dose that inhibits the bacterial load. It will be shown how the results obtained by the application of different chemical-physical techniques (Scanning Electron Microscopy, Fourier Transform Infrared spectroscopy and Light Transmission Analysis) have helped in the evaluation of the impact of the X-rays on leather chemical and physical integrity

Combined effect of cadmium and lead on durum wheat

Cadmium (Cd) and lead (Pb) are two toxic heavy metals (HMs) whose presence in soil is generally low. However, industrial and agricultural activities in recent years have significantly raised their levels, causing progressive accumulations in plant edible tissues, and stimulating research in this field. Studies on toxic metals are commonly focused on a single metal, but toxic metals occur simultaneously. The understanding of the mechanisms of interaction between HMs during uptake is important to design agronomic or genetic strategies to limit contamination of crops. To study the single and combined effect of Cd and Pb on durum wheat, a hydroponic experiment was established to examine the accumulation of the two HMs. Moreover, the molecular mechanisms activated in the roots were investigated paying attention to transcription factors (bHLH family), heavy metal transporters and genes involved in the biosynthesis of metal chelators (nicotianamine and mugineic acid). Cd and Pb are accumulated following different molecular strategies by durum wheat plants, even if the two metals interact with each other influencing their respective uptake and translocation. Finally, we demonstrated that some genes (bHLH 29, YSL2, ZIF1, ZIFL1, ZIFL2, NAS2 and NAAT) were induced in the durum wheat roots only in response to Cd

Comment on the narrow structure reported by Amaryan et al

The CLAS Collaboration provides a comment on the physics interpretation of the results presented in a paper published by M. Amaryan et al. regarding the possible observation of a narrow structure in the mass spectrum of a photoproduction experiment.Comment: to be published in Physical Review