Evaluation of the Pivot Profile©, a new method to characterize a large variety of a single product: Case study on honeys from around the world.

Honey is a natural product with very diverse sensory attributes that are influenced by the flower source, the bee species, the geographic origin, the treatments and conditions during storage. This study aimed at describing 50 honeys from diverse flower sources in different continents and islands, stored under various conditions. Many articles have been published on the sensory characterization of honeys, thus a common list of attributes has been established, but it appeared to be poorly suited to describe a large number of honeys from around the world. This is why the novel and rapid sensory evaluation method, the Pivot Profile©, was tested, with the participation of 15 panelists during five sessions. The first objective was to obtain a sensory description of the 50 honeys that were tested. From 1152 distinct terms, a list of 29 sensory attributes was established and the attributes divided into three categories: color/texture (8 terms), aroma (16 terms), and taste (5 terms). At first, the honeys have been ranked according to their level of crystallization from fluid/liquid to viscous/hard. Then color was the second assessment factor of the variability. In terms of aroma, honeys from Africa were characterized by smoky, resin, caramel and dried fruit as opposed to floral and fruity, mainly for honeys from South America and Europe. Finally, the honeys were ranked according to their sweetness. The second objective of this study was to test the new sensory method, called Pivot Profile© which is used to describe a large number of products with interpretable results.

Involvement of cyclin-dependent kinases in axotomy-induced retinal ganglion cell death.

We have tested the role of cyclin-dependent kinases (CDKs) in the type 3B death of axotomized retinal ganglion cells, by injecting intraocularly olomoucine, roscovitine, or butyrolactone I. Each of these inhibits CDK1, CDK2, and CDK5; CDK1 and CDK2 are involved in cell proliferation, whereas CDK5 is involved in neuronal differentiation. The inhibitors partially protected ganglion cells against the effects of axotomy. These agents may affect the ganglion cells directly, because CDK1, its regulatory subunit cyclin B1, and CDK5 were identified immunohistochemically in the perikarya of ganglion cells, and this was confirmed for CDK1 and CDK5 in Western blots of the ganglion cell layer. These blots showed an axotomy-induced phosphorylation of CDK5 occurring remarkably quickly (within 6 hours of axotomy) but little if any change in the phosphorylation state of CDK1. In addition, we studied the expression of proliferation markers, including proliferating cell nuclear antigen (PCNA) and the synthesis of DNA, by immunohistochemical and autoradiographic methods. Normal or axotomized ganglion cells did not express PCNA and did not synthesize DNA. Although we cannot exclude the possibility that axotomized ganglion cells may leave their quiescent state, our data show that they did not progress beyond the G1 phase of the cell cycle. Finally, in contrast to inhibitors of CDKs, cell cycle blockers with different targets than CDKs did not protect ganglion cells. Globally, our results suggest that axotomy-induced death of ganglion cells involves the activation of CDK1, CDK2, or CDK5 (most probably CDK5) but not the full cell cycle machinery.