484 research outputs found
Inv21p12q22del21q22 and intellectual disability
Chromosomal rearrangements are common in humans. Pericentric inversions are among the most frequent aberrations (1-2%). Most inversions are balanced and do not cause problems in carriers unless one of the breakpoints disrupts important functional genes, has near submicroscopic copy number variants or hosts "cryptic" complex chromosomal rearrangements. Pericentric inversions can lead to imbalance in offspring. Less than 3% of Down syndrome patients have duplication as a result of parental pericentric inversion of chromosome 21. We report a family with an apparently balanced pericentric inversion of chromosome 21. The proband, a 23-year-old female was referred for prenatal diagnosis at 16weeks gestation because of increased nuchal translucency. She has a familial history of Down's syndrome and moderate intellectual disability, a personal history of four spontaneous abortions and learning difficulties. Peripheral blood and amniotic fluid samples were collected to perform proband's and fetus' cytogenetic analyses. Additionally, another six family members were evaluated and cytogenetic analysis was performed. Complementary FISH and MLPA studies were carried out. An apparent balanced chromosome 21 pericentric inversion was observed in four family members, two revealed a recombinant chromosome 21 with partial trisomy, and one a full trisomy 21 with an inverted chromosome 21. Array CGH analysis was performed in the mother and the brother's proband. MLPA and aCGH studies identified a deletion of about 1.7Mb on the long arm of inverted chromosome 21q22.11. We believe the cause of the intellectual disability/learning difficulties observed in the members with the inversion is related to this deletion. The recombinant chromosome 21 has a partial trisomy including the DSCR with no deletion. The risk for carriers of having a child with multiple malformations/intellectual disability is about 30% depending on whether and how this rearrangement interferes with meiosis
Listeria monocytogenes encodes a functional ESX-1 secretion system whose expression is detrimental to in vivo infection
Bacterial pathogenicity deeply depends on the ability to secrete virulence factors that bind specific targets on host cells and manipulate host responses. The Gram-positive bacterium Listeria monocytogenes is a human foodborne pathogen that remains a seriThis work was supported for the DC lab by national funds through FCT - Fundacao para a Ciencia e a Tecnologia/MEC Ministerio da Educacao e Ciencia and co-funded by FEDER funds within the partnership agreement PT2020 related with the research unit number
The β-carboline alkaloid harmine inhibits telomerase activity of MCF-7 cells by down-regulating hTERT mRNA expression accompanied by an accelerated senescent phenotype
The end replication problem, which occurs in normal somatic cells inducing replicative senescence, is solved in most cancer cells by activating telomerase. The activity of telomerase is highly associated with carcinogenesis which makes the enzyme an attractive biomarker in cancer diagnosis and treatment. The indole alkaloid harmine has multiple pharmacological properties including DNA intercalation which can lead to frame shift mutations. In this study, harmine was applied to human breast cancer MCF-7 cells. Its activity towards telomerase was analyzed by utilizing the telomeric repeat amplification protocol (TRAP). Our data indicate that harmine exhibits a pronounced cytotoxicity and induces an anti-proliferation state in MCF-7 cells which is accompanied by a significant inhibition of telomerase activity and an induction of an accelerated senescence phenotype by over-expressing elements of the p53/p21 pathway
Guaranteed optimal reachability control of reaction-diffusion equations using one-sided Lipschitz constants and model reduction
We show that, for any spatially discretized system of reaction-diffusion, the
approximate solution given by the explicit Euler time-discretization scheme
converges to the exact time-continuous solution, provided that diffusion
coefficient be sufficiently large. By "sufficiently large", we mean that the
diffusion coefficient value makes the one-sided Lipschitz constant of the
reaction-diffusion system negative. We apply this result to solve a finite
horizon control problem for a 1D reaction-diffusion example. We also explain
how to perform model reduction in order to improve the efficiency of the
method
Synthesis and characterization of polystyrene-blockpoly(vinylbenzoic acid): a promising compound for manipulating photoresponsive properties at the nanoscale
"Published online: 27 January 2015"Using reversible addition-fragmentation chain
transfer (RAFT) polymerization, the effect of PSt macroRAFT
and 4VBA ratio on the synthesis of a carboxylic
acid functional block copolymer (PSt-b-P4VBA) was
studied. PSt macroRAFT polymer was initially prepared
followed by the insertion of 4-vinylbenzoic acid (4VBA)
monomer. The chemical structure of the diblock copolymer
was confirmed by NMR and FTIR. The effect of PSt
macroRAFT and 4VBA ratio on copolymerization yield
and on molecular weight distribution was assessed by gel
permeation chromatography. The rate of polymerization
did not change as the 4VBA/PSt macroRAFT ratio
increased, indicating an ideal amount of 4VBA insertion.
An optimal ratio of [PSt macroRAFT]:[AIBN]:[4VBA]
was 1.2:1:180. DSC and XRD confirmed the amorphous
structure of homo and copolymer. Thermal stability was
higher for PSt-b-P4VBA forming activated porous carbon
char by dehydration, carbonization and oxidation. SEM
and STEM observations showed a morphological evolution
between PSt macroRAFT and the correspondent
copolymer.The authors acknowledge the n-STeP-Nanostructured systems for Tailored Performance, with reference NORTE-07-0124-FEDER-000039, supported by the Programa Operacional Regional do Norte (ON.2), PEst-C/CTM/LA0025/2013 (Strategic Project-LA 25-2013-2014)
Azimuthal anisotropy and correlations at large transverse momenta in and Au+Au collisions at = 200 GeV
Results on high transverse momentum charged particle emission with respect to
the reaction plane are presented for Au+Au collisions at =
200 GeV. Two- and four-particle correlations results are presented as well as a
comparison of azimuthal correlations in Au+Au collisions to those in at
the same energy. Elliptic anisotropy, , is found to reach its maximum at
GeV/c, then decrease slowly and remain significant up to
-- 10 GeV/c. Stronger suppression is found in the back-to-back
high- particle correlations for particles emitted out-of-plane compared to
those emitted in-plane. The centrality dependence of at intermediate
is compared to simple models based on jet quenching.Comment: 4 figures. Published version as PRL 93, 252301 (2004
Azimuthal anisotropy in Au+Au collisions at sqrtsNN = 200 GeV
The results from the STAR Collaboration on directed flow (v_1), elliptic flow
(v_2), and the fourth harmonic (v_4) in the anisotropic azimuthal distribution
of particles from Au+Au collisions at sqrtsNN = 200 GeV are summarized and
compared with results from other experiments and theoretical models. Results
for identified particles are presented and fit with a Blast Wave model.
Different anisotropic flow analysis methods are compared and nonflow effects
are extracted from the data. For v_2, scaling with the number of constituent
quarks and parton coalescence is discussed. For v_4, scaling with v_2^2 and
quark coalescence is discussed.Comment: 26 pages. As accepted by Phys. Rev. C. Text rearranged, figures
modified, but data the same. However, in Fig. 35 the hydro calculations are
corrected in this version. The data tables are available at
http://www.star.bnl.gov/central/publications/ by searching for "flow" and
then this pape
Self-Mating in the Definitive Host Potentiates Clonal Outbreaks of the Apicomplexan Parasites Sarcocystis neurona and Toxoplasma gondii
Tissue-encysting coccidia, including Toxoplasma gondii and Sarcocystis neurona, are heterogamous parasites with sexual and asexual life stages in definitive and intermediate hosts, respectively. During its sexual life stage, T. gondii reproduces either by genetic out-crossing or via clonal amplification of a single strain through self-mating. Out-crossing has been experimentally verified as a potent mechanism capable of producing offspring possessing a range of adaptive and virulence potentials. In contrast, selfing and other life history traits, such as asexual expansion of tissue-cysts by oral transmission among intermediate hosts, have been proposed to explain the genetic basis for the clonal population structure of T. gondii. In this study, we investigated the contributing roles self-mating and sexual recombination play in nature to maintain clonal population structures and produce or expand parasite clones capable of causing disease epidemics for two tissue encysting parasites. We applied high-resolution genotyping against strains isolated from a T. gondii waterborne outbreak that caused symptomatic disease in 155 immune-competent people in Brazil and a S. neurona outbreak that resulted in a mass mortality event in Southern sea otters. In both cases, a single, genetically distinct clone was found infecting outbreak-exposed individuals. Furthermore, the T. gondii outbreak clone was one of several apparently recombinant progeny recovered from the local environment. Since oocysts or sporocysts were the infectious form implicated in each outbreak, the expansion of the epidemic clone can be explained by self-mating. The results also show that out-crossing preceded selfing to produce the virulent T. gondii clone. For the tissue encysting coccidia, self-mating exists as a key adaptation potentiating the epidemic expansion and transmission of newly emerged parasite clones that can profoundly shape parasite population genetic structures or cause devastating disease outbreaks
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