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The pathological changes in osteoarthritis—a degenerative joint disease prevalent among older people—start at the molecular scale and spread to the higher levels of the architecture of articular cartilage to cause progressive and irreversible structural and functional damage. At present, there are no treatments to cure or attenuate the degradation of cartilage. Early detection and the ability to monitor the progression of osteoarthritis are therefore important for developing effective therapies. Here, we show that indentation-type atomic force microscopy can monitor age-related morphological and biomechanical changes in the hips of normal and osteoarthritic mice. Early damage in the cartilage of osteoarthritic patients undergoing hip or knee replacements could similarly be detected using this method. Changes due to aging and osteoarthritis are clearly depicted at the nanometre scale well before morphological changes can be observed using current diagnostic methods. Indentation-type atomic force microscopy may potentially be developed into a minimally invasive arthroscopic tool to diagnose the early onset of osteoarthritis in situ. [ABSTRACT FROM AUTHOR]

Seven isoforms of 85 kDa polypeptides (p85) were identified as methionine synthase (MetE) homologs by partial aminoacid sequencing in tobacco pollen tube extracts. Immunocytochemistry data showed a localization of the antigen on the surface of tip-focussed post-Golgi secretory vesicles (SVs), that appear to be partially associated with microtubules (Mts). The chemical dissection of pollen tube high speed supernatant (HSS) showed that two distinct pools of MetE are present in pollen tubes, one being the more acidic isoforms sedimenting at 15S and the remaining at 4S after zonal centrifugation through a sucrose density gradient. The identification of the MetE within the pollen tube and its possible participation as methyl donor in a wide range of metabolic reactions, makes it a good subject for studies on pollen tube growth regulation. [ABSTRACT FROM AUTHOR]

Reduction of HAuCl by NaSCN or KSCN produces colloidal gold particles of 2.6 nm in diameter and homogeneous in size (coefficient of variation ∼15%). The Au sol forms protein-gold complexes. The amount of protein required to form an Au-protein complex is best determined in the electron microscope, where serial dilutions of protein with gold sol are inspected for the presence of aggregates. By immuno-electron microscopy SCN-gold complexed to protein A is active and visible as is shown by revealing α-amylase in rat pancreatic acinar cells. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented in response to the article on the efficacy of triclosan in treating malaria in rodents.

A correction to the article "Early Detection of Aging Cartilage and Osteoarthritis in Mice and Patient Samples Using Atomic Force Microscopy" that was published in the February 1, 2009 issue is presented.