3 research outputs found
Epidemiology of flavescence dor\ue9e in vineyards in north-western Italy
A serious outbreak of flavescence dor\ue9e (FD) was reported in
Piemonte, northwestern Italy, in 1998, and since then, the disease has
compromised the economy of this traditional wine-growing area, even
following the application of compulsory insecticide treatments to control
Scaphoideus titanus, the vector of the causal phytoplasma. Affected vines
show severe symptoms, varying according to the cultivar, and are rogued
to reduce disease spread. Following winter and pruning, a previously
affected vine may appear symptomless and free of phytoplasmas in its
aerial as well as its root system, even by nested-polymerase chain reaction
assays. Such plants are considered to be \u201crecovered\u201d. Since 1998
homogenous data on the incidence of newly infected, healthy, or recovered
plants productivity, presence of vectors, and treatment schedules
have been collected in seven severely affected vineyards of southern
Piemonte for 5 years (1999 to 2003). Infectivity and recovery rates were
also calculated each year. From 1999 to 2003, the average number of
healthy plants decreased and the numbers of recovered plants and those
with symptoms increased. Productivity of recovered vines, although
lower than that of healthy ones, was always higher than that of vines with
symptoms and was not influenced by the time elapsed from date of recovery.
The relationships between the ln-transformed number of vectors
trapped in the vineyards the previous year and the infection and the recovery
rates were fitted by an exponential (R2 = 0.95) and an asymptotic
(R2 = 0.93) model, respectively
Amyposomes, a nanotechnological chaperone with anti-amyloidogenic activity
Aim: The effect of liposomes bi-functionalized with phosphatidic acid and with a synthetic peptide derived from human apolipoprotein E has been evaluated on the aggregation features of different amyloidogenic proteins: human Amyloid β1-40 (Aβ1-40), transthyretin (TTR) variant S52P, human β2microglobulin (β2m) variants ΔN6 and D76N, Serum Amyloid A (SAA). Methods: The formation of fibrillar aggregates of the proteins was investigated by ThioflavinT fluorescence assay and validated by Atomic Force Microscopy. Results: The results show that liposomes are preventing the transition of non-aggregated forms to the fibrillar state, with stronger effects on Aβ1-40, β2m ΔN6 and SAA. Liposomes also induce disaggregation of the amyloid aggregates of all the proteins investigated, with stronger effects on Aβ1-40, β2 D76N and TTR.SPR assays show that liposomes bind Aβ1-40 and SAA aggregates with high affinity (KD in the nanomolar range) whereas binding to TTR aggregates showed a lower affinity (KD in the micromolar range). Aggregates of β2m variants showed both high and low affinity binding sites. Computed Structural analysis of protein fibrillar aggregates and considerations on the multidentate features of liposomes allow to speculate a common mechanism of action, based on binding the β-stranded peptide regions responsible for the amyloid formation. Conclusion: Thus, multifunctional liposomes perform as pharmacological chaperones with anti-amyloidogenic activity, with a promising potential for the treatment of a number of protein-misfolding diseases.Key messageAmyloidosis is a group of diseases, each due to a specific protein misfolding.Anti-amyloidogenic nanoparticles have been gaining the utmost importance as a potential treatment for protein misfolding disorders.Liposomes bi-functionalized with phosphatidic acid and with a synthetic peptide derived from human apolipoprotein E showed anti-amyloidogenic activity