15 research outputs found
Fungal communities of the Pine Wilt Disease Complex: Studying the Interaction of Ophiostomatales with Bursaphelenchus xylophilus
Considered one of the most devastating plant–parasitic nematodes worldwide,
Bursaphelenchus xylophilus (commonly known as pinewood nematode, PWN) is the
causal agent of the pine wilt disease in the Eurasian coniferous forests. This migratory
parasitic nematode is carried by an insect vector (Monochamus spp.) into the host
tree (Pinus species), where it can feed on parenchymal cells and reproduce massively,
resulting in the tree wilting. In declining trees, PWN populations are strongly dependent
on fungal communities colonizing the host (predominantly ophiostomatoid fungi known
to cause sapwood blue-staining, the blue-stain fungi), which not only influence their
development and life cycle but also the number of individuals carried by the insect vector
into a new host. Our main aim is to understand if PWN-associated mycobiota plays a
key role in the development of PWD, in interaction with the PWN and the insect vector,
and to what extent it can be targeted to disrupt the disease cycle. For this purpose, we
characterized the fungal communities of Pinus pinaster trees infected and non-infected
with PWN in three collection sites in Continental Portugal with different PWD temporal
incidences. Our results showed that non-infected P. pinaster mycoflora is more diverse
(in terms of abundance and fungal richness) than PWN-infected pine trees in the most
recent PWD foci, as opposed to the fungal communities of long-term PWD history
sites. Then, due to their ecological importance for PWN survival, representatives of the
main ophiostomatoid fungi isolated (Ophiostoma, Leptographium, and Graphilbum) were
characterized for their adaptative response to temperature, competition in-between taxa,
and as food source for PWN. Under the conditions studied, Leptographium isolates
showed promising results for PWN control. They could outcompete the other species,
especially O. ips, and significantly reduce the development of PWN populations when
compared to Botrytis cinerea (routinely used for PWN lab culturing), suggesting this to
be a natural antagonist not only for the other blue-stain species but also for the PWN
Quando a expressão plástica e a matemática dão as mãos
info:eu-repo/semantics/publishedVersio
Oral particle uptake and organ targeting drives the activity of amphotericin B nanoparticles
There are very few drug delivery
systems that target key organs
via the oral route, as oral delivery advances normally address gastrointestinal
drug dissolution, permeation, and stability. Here we introduce a nanomedicine
in which nanoparticles, while also protecting the drug from gastric
degradation, are taken up by the gastrointestinal epithelia and transported
to the lung, liver, and spleen, thus selectively enhancing drug bioavailability
in these target organs and diminishing kidney exposure (relevant to
nephrotoxic drugs). Our work demonstrates, for the first time, that
oral particle uptake and translocation to specific organs may be used
to achieve a beneficial therapeutic response. We have illustrated
this using amphotericin B, a nephrotoxic drug encapsulated within <i>N</i>-palmitoyl-<i>N</i>-methyl-<i>N</i>,<i>N</i>-dimethyl-<i>N</i>,<i>N</i>,<i>N</i>-trimethyl-6-<i>O</i>-glycol chitosan
(GCPQ) nanoparticles, and have evidenced our approach in three separate
disease states (visceral leishmaniasis, candidiasis, and aspergillosis)
using industry standard models of the disease in small animals. The
oral bioavailability of AmB-GCPQ nanoparticles is 24%. In all disease
models, AmB-GCPQ nanoparticles show comparable efficacy to parenteral
liposomal AmB (AmBisome). Our work thus paves the way for others to
use nanoparticles to achieve a specific targeted delivery of drug
to key organs via the oral route. This is especially important for
drugs with a narrow therapeutic index
Clinical validation of cutoff target ranges in newborn screening of metabolic disorders by tandem mass spectrometry: A worldwide collaborative project.
Purpose: To achieve clinical validation of cutoff values for newborn screening by tandem mass
215 spectrometry through a worldwide collaboration. Methods: Cumulative percentiles of amino
216 acids and acylcarnitines in dried blood spots of approximately 30 million normal newborns and
217 10,615 true positive cases are compared to assign clinical significance, which is achieved when
218 the median of a disease range is either >99%ile or <1%ile of the normal population. The cutoff
219 target ranges of analytes and ratios are then defined as the interval between the limits of the two
220 populations. When overlaps occur, adjustments are made to maximize sensitivity and specificity
221 taking in consideration all available factors. Results: As of December 1, 2010, 129 sites in 45
222 countries have uploaded to the project website a total of 23,970 percentile data points, 558,168
223 analyte results of 10,615 true positive cases with 64 conditions, and 5,088 cutoff values. The
224 average rate of submission of true positive cases between December 1, 2008 and December 1,
225 2010 was 4.7 cases per day (3,418 cases). This cumulative evidence generated 91 and 23 high
226 and low target cutoff ranges, respectively. The overall proportion of cutoff values within the
227 respective target range was 43% (2,176/5,088). Conclusions: An unprecedented level of
228 cooperation and collaboration has allowed the objective definition of cutoff target ranges for 114
229 markers applied to newborn screening of rare metabolic disorders. This set of data could be used
230 as baseline for monitoring of future performance
Clinical validation of cutoff target ranges in newborn screening of metabolic disorders by tandem mass spectrometry: A worldwide collaborative project
PURPOSE:: To achieve clinical validation of cutoff values for newborn screening by tandem mass spectrometry through a worldwide collaborative effort. METHODS:: Cumulative percentiles of amino acids and acylcarnitines in dried blood spots of approximately 25-30 million normal newborns and 10,742 deidentified true positive cases are compared to assign clinical significance, which is achieved when the median of a disorder range is, and usually markedly outside, either the 99th or the 1st percentile of the normal population. The cutoff target ranges of analytes and ratios are then defined as the interval between selected percentiles of the two populations. When overlaps occur, adjustments are made to maximize sensitivity and specificity taking all available factors into consideration. RESULTS:: As of December 1, 2010, 130 sites in 45 countries have uploaded a total of 25,114 percentile data points, 565,232 analyte results of true positive cases with 64 conditions, and 5,341 cutoff values. The average rate of submission of true positive cases between December 1, 2008, and December 1, 2010, was 5.1 cases/day. This cumulative evidence generated 91 high and 23 low cutoff target ranges. The overall proportion of cutoff values within the respective target range was 42% (2,269/5,341). CONCLUSION:: An unprecedented level of cooperation and collaboration has allowed the objective definition of cutoff target ranges for 114 markers to be applied to newborn screening of rare metabolic disorders. © 2011 Lippincott Williams & Wilkins