66 research outputs found
Circulating hematopoietic stem cells and putative intestinal stem cells in coeliac disease
Background:
The intestinal stem cells (ISC) modulation and the role of circulating hematopoietic stem cells (HSC) in coeliac disease (CD) are poorly understood. Our aim was to investigate the longitudinal modifications in peripheral blood HSC traffic and putative ISC density induced by gluten-free diet (GFD) in CD.
Methods:
Thirty-one CD patients and 7 controls were enrolled. Circulating CD133+ and CD34+ HSC were measured by flow cytometry, at enrolment and after 7 days and 1, 3, 6, 12, and 24 months of GFD. Endoscopy was performed at diagnosis and repeated at 6, 12, and 24 months following GFD. We used the Marsh-Oberhuber score to evaluate the histological severity of duodenal damage; immunohistochemistry was employed to measure the intraepithelial lymphoid infiltrate (IEL, CD3+ lymphoid cells) and the putative ISC compartment (CD133+ and Lgr5+ epithelial cells).
Results:
At enrolment, circulating HSCs were significantly increased in CD patients and they further augmented during the first week of GFD, but progressively decreased afterwards. CD patients presented with villous atrophy, abundant IEL and rare ISC residing at the crypt base. Upon GFD, IEL progressively decreased, while ISC density increased, peaking at 12 months. After 24 months of GFD, all patients were asymptomatic and their duodenal mucosa was macroscopically and histologically normal.
Conclusions:
In active CD patients, the ISC niche is depleted and there is an increased traffic of circulating HSC versus non-coeliac subjects. GFD induces a precocious mobilization of circulating HSC, which is followed by the expansion of the local ISC compartment, leading to mucosal healing and clinical remission
Allelic Variation, Alternative Splicing and Expression Analysis of Psy1 Gene in Hordeum chilense Roem. et Schult
Background: The wild barley Hordeum chilense Roem. et Schult. is a valuable source of genes for increasing carotenoid content in wheat. Tritordeums, the amphiploids derived from durum or common wheat and H. chilense, systematically show higher values of yellow pigment colour and carotenoid content than durum wheat. Phytoene synthase 1 gene (Psy1) is considered a key step limiting the carotenoid biosynthesis, and the correlation of Psy1 transcripts accumulation and endosperm carotenoid content has been demonstrated in the main grass species. Methodology/Principal findings: We analyze the variability of Psy1 alleles in three lines of H. chilense (H1, H7 and H16) representing the three ecotypes described in this species. Moreover, we analyze Psy1 expression in leaves and in two seed developing stages of H1 and H7, showing mRNA accumulation patterns similar to those of wheat. Finally, we identify thirtysix different transcripts forms originated by alternative splicing of the 59 UTR and/or exons 1 to 5 of Psy1 gene. Transcripts function is tested in a heterologous complementation assay, revealing that from the sixteen different predicted proteins only four types (those of 432, 370, 364 and 271 amino acids), are functional in the bacterial system. Conclusions/Significance: The large number of transcripts originated by alternative splicing of Psy1, and the coexistence of functional and non functional forms, suggest a fine regulation of PSY activity in H. chilense. This work is the first analysis of H. chilense Psy1 gene and the results reported here are the bases for its potential use in carotenoid enhancement in duru
Workshop summary:Kaons@CERN 2023
Kaon physics is at a turning point – while the rare-kaon experiments NA62 and KOTO are in full swing, the end of their lifetime is approaching and the future experimental landscape needs to be defined. With HIKE, KOTO-II and LHCb-Phase-II on the table and under scrutiny, it is a very good moment in time to take stock and contemplate about the opportunities these experiments and theoretical developments provide for particle physics in the coming decade and beyond. This paper provides a compact summary of talks and discussions from the Kaons@CERN 2023 workshop, held in September 2023 at CERN
A new measurement of the K±→π±γγ decay at the NA48/2 experiment
The NA48/2 experiment at CERN collected two data samples with minimum bias trigger conditions in 2003 and 2004. A measurement of the rate and dynamic properties of the rare decay K±→π±γγK±→π±γγ from these data sets based on 149 decay candidates with an estimated background of 15.5±0.715.5±0.7 events is reported. The model-independent branching ratio in the kinematic range z=(mγγ/mK)2>0.2z=(mγγ/mK)2>0.2 is measured to be BMI(z>0.2)=(0.877±0.089)×10−6BMI(z>0.2)=(0.877±0.089)×10−6, and the branching ratio in the full kinematic range assuming a particular Chiral Perturbation Theory description to be B(Kπγγ)=(0.910±0.075)×10−6B(Kπγγ)=(0.910±0.075)×10−6
Direct search for light gluinos
We present the results for a direct search for light gluinos through the appearance of with high transverse momentum in the vacuum tank of the NA48 experiment at CERN. We find one event within a lifetime range of s and another one between s. Both events are consistent with the expected background from neutrons in the beam, produced by 450 GeV protons impinging on the Be targets, which interact with the residual air in the tank. From these data we give limits on the production of the hypothetical bound state, the hadron, and its decay in the mass range between 1 and 5~GeV
Measurement of the very rare decay
The decay K+→π+νν¯
, with a very precisely predicted branching ratio of less than 10−10
,
is among the best processes to reveal indirect effects of new physics.
The NA62 experiment at CERN SPS is designed to study the K+→π+νν¯
decay and to measure its branching ratio using a decay-in-flight technique.
NA62 took data in 2016, 2017 and 2018, reaching the sensitivity of the Standard Model
for the K+→π+νν¯
decay by the analysis of the 2016 and 2017 data,
and providing the most precise measurement of the branching ratio to date
by the analysis of the 2018 data.
This measurement is also used to set limits on BR(K+→π+X
), where X
is a scalar
or pseudo-scalar particle.
The final result of the BR(K+→π+νν¯
) measurement and its interpretation in terms
of the K+→π+X
decay from the analysis of the full 2016-2018 data set is presented, and future plans and prospects are reviewed
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