Discovery of 2,4-bis-arylamino-1,3-pyrimidines as insulin-like growth factor-1 receptor (IGF-1R) inhibitors

The insulin-like growth factor-1 receptor (IGF-1R) plays an important role in the regulation of cell growth and differentiation, and in protection from apoptosis. IGF-1R has been shown to be an appealing target for the treatment of human cancer. Herein, we report the synthesis, structure-activity relationships (SAR), X-ray cocrystal structure and in vivo tumor study results for a series of 2,4-bis-arylamino-1,3-pyrimidines.     

Keeping Plant Tissue Slices Attached to the Slide During Harsh Extraction of PoIysaccharide

During extraction of hemicellulose and noncellulose polysaccharides from plant histological slices of plants the morphological integrity of the slices may be disturbed if the reagents extracting hemicellulose and noncellulose polysaccharides are rinsed away by water. Removing the reagents by delicate suction rather than removing the glass tray from the staining dish, followed by desiccation and a rinse in 95% ethanol terminates the treatment without altering the morphology of the tissues.     

The Small Heat Shock Protein Hsp27 Affects Assembly Dynamics and Structure of Keratin Intermediate Filament Networks

The mechanical properties of living cells are essential for many processes. They are defined by the cytoskeleton, a composite network of protein fibers. Thus, the precise control of its architecture is of paramount importance. Our knowledge about the molecular and physical mechanisms defining the network structure remains scarce, especially for the intermediate filament cytoskeleton. Here, we investigate the effect of small heat shock proteins on the keratin 8/18 intermediate filament cytoskeleton using a well-controlled model system of reconstituted keratin networks. We demonstrate that Hsp27 severely alters the structure of such networks by changing their assembly dynamics. Furthermore, the C-terminal tail domain of keratin 8 is shown to be essential for this effect. Combining results from fluorescence and electron microscopy with data from analytical ultracentrifugation reveals the crucial role of kinetic trapping in keratin network formation.     

Semaphorin 5A is a bifunctional axon guidance cue for axial motoneurons in vivo

Semaphorins are a large class of proteins that function throughout the nervous system to guide axons. It had previously been shown that Semaphorin 5A (Sema5A) was a bifunctional axon guidance cue for mammalian midbrain neurons. We found that zebrafish sema5A was expressed in myotomes during the period of motor axon outgrowth. To determine whether Sema5A functioned in motor axon guidance, we knocked down Sema5A, which resulted in two phenotypes: a delay in motor axon extension into the ventral myotome and aberrant branching of these motor axons. Both phenotypes were rescued by injection of full-length rat Sema5A mRNA. However, adding back RNA encoding the sema domain alone significantly rescued the branching phenotype in sema5A morphants. Conversely, adding back RNA encoding the thrombospondin repeat (TSR) domain alone into sema5A morphants exclusively rescued delay in ventral motor axon extension. Together, these data show that Sema5A is a bifunctional axon guidance cue for vertebrate motor axons in vivo. The TSR domain promotes growth of developing motor axons into the ventral myotome whereas the sema domain mediates repulsion and keeps these motor axons from branching into surrounding myotome regions.     

Comparative Histochemical Analysis of Cell Wall Polysaccharides by Enzymatic and Chemical Extractions of Two Fruits

A protocol for extracting polysaccharides from cell walls has been modified and used to analyze histochemically two fruits with opposite characteristics. Grapes are nonclimacteric fruits and are harvested at full maturity. In contrast, kiwi fruits are climacteric and are harvested and consumed before they are physiologically mature. The two fruits were analyzed histochemically using two protocols. One method is defined as chemical, and is based on subsequential extractions of pectins by chemical agents. The other is defined as enzymatic because it removes pectins using pectinase followed by hot ammonium oxalate. In both protocols, two types of hemicellulosic polymers are removed by 1 M and 4 M/KOH leaving a cellulosic residue on the slide. Both protocols remove the same amount of pectins, thus confirming their precision. The sum of hemicellulose and the cellulosic insoluble residue are equivalent using the two methods, but the relative amounts of the cellulose and hemicellulosic polymers were dependent upon the method of extraction. When the enzyme was used to extract the pectins, there was less cellulose and more hemicellulose. The removal of polysaccharides by ammonium oxalate and by guanidinethio-cyanate in the enzymatic and the chemical protocols, respectively, yielded approximately the same amount of removed material.

Similar results were obtained from both fruits. Grape, being softer than kiwi fruit, was relatively richer in pectic substances and less rich in hemicellulose and cellulose polymers. No difference in cell wall material could be ascribed to the different ripening habits.     

Functional exploratory data analysis for high‐resolution measurements of urban particulate matter

In this work we propose the use of functional data analysis (FDA) to deal with a very large dataset of atmospheric aerosol size distribution resolved in both space and time. Data come from a mobile measurement platform in the town of Perugia (Central Italy). An OPC (Optical Particle Counter) is integrated on a cabin of the Minimetrò, an urban transportation system, that moves along a monorail on a line transect of the town. The OPC takes a sample of air every six seconds and counts the number of particles of urban aerosols with a diameter between 0.28 m and 10 m and classifies such particles into 21 size bins according to their diameter. Here, we adopt a 2D functional data representation for each of the 21 spatiotemporal series. In fact, space is unidimensional since it is measured as the distance on the monorail from the base station of the Minimetrò. FDA allows for a reduction of the dimensionality of each dataset and accounts for the high space‐time resolution of the data. Functional cluster analysis is then performed to search for similarities among the 21 size channels in terms of their spatiotemporal pattern. Results provide a good classification of the 21 size bins into a relatively small number of groups (between three and four) according to the season of the year. Groups including coarser particles have more similar patterns, while those including finer particles show a more different behavior according to the period of the year. Such features are consistent with the physics of atmospheric aerosol and the highlighted patterns provide a very useful ground for prospective model‐based studies.