Ultrastructural study of Chlamydomonas cilia shows that anterograde IFT particles form trains that are long and narrow, while retrograde IFT form short, compact particle trains.

Alkaptonuria (AKU) is an ultra-rare disease developed from the lack of homogentisic acid oxidase activity, causing homogentisic acid (HGA) accumulation that produces a HGA-melanin ochronotic pigment, of unknown composition. There is no therapy for AKU. Our aim was to verify if AKU implied a secondary amyloidosis. Congo Red, Thioflavin-T staining and TEM were performed to assess amyloid presence in AKU specimens (cartilage, synovia, periumbelical fat, salivary gland) and in HGA-treated human chondrocytes and cartilage. SAA and SAP deposition was examined using immunofluorescence and their levels were evaluated in the patients' plasma by ELISA. 2D electrophoresis was undertaken in AKU cells to evaluate the levels of proteins involved in amyloidogenesis. AKU osteoarticular tissues contained SAA-amyloid in 7/7 patients. Ochronotic pigment and amyloid co-localized in AKU osteoarticular tissues. SAA and SAP composition of the deposits assessed secondary type of amyloidosis. High levels of SAA and SAP were found in AKU patients' plasma. Systemic amyloidosis was assessed by Congo Red staining of patients' abdominal fat and salivary gland. AKU is the second pathology after Parkinson's disease where amyloid is associated with a form of melanin. Aberrant expression of proteins involved in amyloidogenesis has been found in AKU cells. Our findings on alkaptonuria as a novel type II AA amyloidosis open new important perspectives for its therapy, since methotrexate treatment proved to significantly reduce in vitro HGA-induced A-amyloid aggregates.

The synthesis of a series of benzofulvene derivatives 3 related to the recently studied ethyl 1-methylene-3-(4-methylphenyl)-1H-indene-2-carboxylate (BF1) is described. The properties of these trans-diene derivatives were characterized with regard to their capability of polymerizing spontaneously to give new polymers based on functionalized indene monomeric units. The series of polymers has been investigated by NMR spectroscopy, multiangle light scattering online to size exclusion chromatography, UV-vis spectroscopy, mass spectrometry, differential scanning calorimetry, and scanning electron microscopy. The new polymers show very interesting properties such as a thermoreversible polymerization/depolymerization, a variable degree of π-stacking, a tendency to give nanostructured macromolecular aggregates, and a high solubility in the most common organic solvents. Remarkably, this study demonstrated that most of the polymer properties (e.g. formation, molecular weight, structure, thermoreversibility, and aggregation in nanostructured entities) may be modulated by the stereoelectronic characteristics of the substituents present on the indene moiety.

Vinyl polymers carrying l-phenylalanine residues were synthesized in the free and in the cross-linked hydrogel form, as homo- and copolymers with N-isopropylacrylamide (NIPAAm). The protonation reaction thermodynamics of the COO- group were studied in aqueous media, at different temperatures and at increased concentrations of sodium chloride, mainly by potentiometry and solution calorimetry. The soluble polymer, namely poly(N-acryloyl-l-phenylalanine), and its copolymers with low NIPAAm content displayed characteristic features. Their basicity constants (log K), as well as the enthalpy (−ΔH°) changes in relation to α (degree of protonation) showed an abrupt drop at α = 0.5. This was ascribed to the formation of hydrogen bonds between the protonated and the ionized neighboring COO- groups. The process was driven by the side-chain aromatic rings that improved hydrophobic interactions. The entropy (ΔS°) changes sharply increased as a result of the increased macromolecular conformational freedom and the release of water molecules surrounding the hydrophilic groups of the polymer. The corresponding cross-linked polymers formed hydrogels that were responsive to pH, temperature, and ionic strength. The two hydrogels, P9 (homopolymer with 9 mol% cross-links) and CP2 (copolymer with 90 mol% of NIPAAm and 2 mol% cross-links), were characterized for their pH- and temperature-responsive behavior by equilibrium and oscillatory swelling studies. They demonstrated a strong pH-dependent volume phase-transition and an unusual sodium chloride phase-transition phenomenon. Moreover, the hydrogel CP2 exhibited a temperature-dependent volume phase-transition (LCST, lower critical solution temperature) behavior in aqueous solution, where the LCST decreased by lowering the pH. It was nontoxic against the RAW264 cell line.