Upregulation of calcium/calmodulin-dependent kinase II (CaMKII) is implicated in the pathogenesis of osteoarthritis (OA) and reactivation of articular cartilage hypertrophy. However, direct ...inhibition of CaMKII unexpectedly augmented symptoms of OA in animal models. The role of CaMKII in OA remains unclear and requires further investigation.
Analysis of CaMKII expression was performed in normal human and OA articular chondrocytes, and signaling mechanisms were assessed in articular, fetal and Pluripotent Stem Cell (PSC)-derived human chondrocytes using pharmacological (KN93), peptide (AC3-I) and small interfering RNA (siRNA) inhibitors of CaMKII.
Expression levels of phospho-CaMKII (pCaMKII) were significantly and consistently increased in human OA specimens. BMP2/4 activated expression of pCaMKII as well as COLII and COLX in human adult articular chondrocytes, and also increased the levels and nuclear localization of SMADs1/5/8, while TGFβ1 showed minimal or no activation of the chondrogenic program in adult chondrocytes. Targeted blockade of CaMKII with specific siRNAs decreased levels of pSMADs, COLII, COLX and proteoglycans in normal and OA adult articular chondrocytes in the presence of both BMP4 and TGFβ1. Both human fetal and PSC-derived chondrocytes also demonstrated a decrease of chondrogenic differentiation in the presence of small molecule and peptide inhibitors of CaMKII. Furthermore, immunoprecipitation for SMADs1/5/8 or 2/3 followed by western blotting for pCaMKII showed direct interaction between SMADs and pCaMKII in primary chondrocytes.
Current study demonstrates a direct role for CaMKII in TGF-β and BMP-mediated responses in primary and PSC-derived chondrocytes. These findings have direct implications for tissue engineering of cartilage tissue from stem cells and therapeutic management of OA.
It is proposed to exploit the decay of the meson
B
+
→
p
π
+
π
+
Σ
¯
c
-
-
and of its charge conjugate
B
-
copiously produced at LHC to obtain a sample of
Λ
c
baryons through the strong decay
Σ
c
→
Λ
...c
π
. The sample thus obtained is not affected by biases typically introduced by selections that depend on specific decay modes. Therefore it allows a measurement of the absolute branching fraction for the decay of the
Λ
c
baryon into
p
K
π
or into other observable final states to be performed in a model independent manner. The accuracy that can be achieved with this method is discussed and it is shown that it would be either competitive with or an improvement over current measurements.
The feasibility of an electron-polarized, active target to be used as detector in neutrino scattering experiments, suggested by several theoretical papers, has been investigated. We report on the ...properties of the paramagnetic crystal Gd2SiO5 (GSO), in which 7.7% of the total number of electrons present can be polarized by lowering the temperature and applying an intense external magnetic field.
The material magnetic susceptibility has been measured down to cryogenic temperatures showing that for H=5T and T=4K about 80% of the maximum allowed magnetization can be attained. Also the spectral and time response of the crystal have been characterized and the scintillation process has been studied using a photomultiplier to measure the response to gamma rays irradiation and cosmic rays operating the GSO crystal at 13.5K. An avalanche photodiode (APD) readout of the scintillation signal from the GSO crystal has also been performed, since the magnetic field-independent response of this device allows it to be placed close to the crystal in the cryogenic environment.
In this paper, results of a time performance study of triple gas electron multiplier (GEM) detectors are discussed.
This study was driven by an R&D activity on detectors for the Level 0 LHCb muon ...trigger. However, the results presented in this paper are of more general interest, i.e. for experiments with high rate charged particle triggering.
Little interest was given so far to time performance of GEM detectors. Only one group measured double GEM detector time resolution with the Ar/CO
2 (70/30) gas mixture.
Our study aimed at triple GEM detector optimisation for good time performance through a detailed investigation of the role played by detector geometry, electric fields and gas mixture.
The results reported here, in particular when using the gas mixture Ar/CO
2/CF
4 (60/20/20), considerably improve the time performance discussed in the above-mentioned paper and make the triple GEM detector a promising option for high rate charged particle triggering.
The reported incidence of necrotising enterocolitis in neonates with complex CHD with ductus-dependent systemic circulation ranges from 6.8 to 13% despite surgical treatment; the overall mortality is ...between 25 and 97%. The incidence of gastrointestinal complications after hybrid palliation for neonates with ductus-dependent systemic circulation still has to be defined, but seems comparable with that following the Norwood procedure.
We reviewed the incidence of gastrointestinal complications in a series of 42 consecutive neonates with ductus-dependent systemic circulation, who received early hybrid palliation associated with a standardised feeding protocol.
The median age and birth weight at the time of surgery were 3 days (with a range from 1 to 10 days) and 3.07 kg (with a range from 1.5 to 4.5 kg), respectively. The median ICU length of stay was 7 days (1-70 days), and the median hospital length of stay was 16 days (6-70 days). The median duration of mechanical ventilation was 3 days. Hospital mortality was 16% (7/42). In the postoperative period, 26% of patients were subjected to early extubation, and all of them received treatment with systemic vasodilatory agents. Feeding was started 6 hours after extubation according to a dedicated feeding protocol. After treatment, none of our patients experienced any grade of necrotising enterocolitis or major gastrointestinal adverse events.
Our experience indicates that the combination of an "early hybrid approach", systemic vasodilator therapy, and dedicated feeding protocol adherence could reduce the incidence of gastrointestinal complications in this group of neonates. Fast weaning from ventilatory support, which represents a part of our treatment strategy, could be associated with low incidence of necrotising enterocolitis.
Antineutrino induced electron capture is a resonant process that can have a large cross-section for beams of monochromatic antineutrinos. We calculate the cross-section of this process and ...investigate an experimental setup where monochromatic antineutrinos are produced from the bound-beta decay of fully ionized radioactive atoms in a storage ring. If the energy between the source and the target is well matched, the cross-sections can be significantly larger than the cross-sections of commonly used non-resonant processes. The rate that can be achieved at a small distance between the source and two targets of 10
3
kg is up to one interaction per 8.3⋅10
18
decaying atoms. For a source-target distance corresponding to the first atmospheric neutrino oscillation maximum, the largest rate is one interaction per 3.2⋅10
21
decaying atoms, provided that extremely stringent monochromaticity conditions (10
−7
or better) are achieved in future ion beams.
To test the feasibility of altering the phenotype of umbilical cord blood mesenchymal stem cells (UCB MSCs) toward that of human corneal endothelial cells (HCEC) and to determine whether UCB MSCs can ..."home" to sites of corneal endothelial cell injury using an ex vivo corneal wound model.
RNA was isolated and purified from UCB MSCs and HCECs. Baseline information regarding the relative gene expression of UCB MSCs and HCEC was obtained by microarray analysis. Quantitative real-time PCR (q-PCR) verified the microarray findings for a subset of genes. The ability of different culture media to direct UCB MSCs toward a more HCEC-like phenotype was tested in both tissue culture and ex vivo corneal endothelial wound models using three different media: MSC basal medium (MSCBM), a basal medium used to culture lens epithelial cells (LECBM), or lens epithelial cell-conditioned medium (LECCM). Morphology of the MSCs was observed by phase-contrast microscopy or by light microscopic observation of crystal violet-stained cells. Immunolocalization of the junction-associated proteins, zonula occludins-1 (ZO1) and N-cadherin, was visualized by fluorescence confocal microscopy. Formation of cell-cell junctions was tested by treatment with the calcium chelator, EGTA. A second microarray analysis compared gene expression between UCB MSCs grown in LECBM and LECCM to identify changes induced by the lens epithelial cell-conditioned culture medium. The ability of UCB MSCs to "home" to areas of endothelial injury was determined using ZO1 immunolocalization patterns in ex vivo corneal endothelial wounds.
Baseline microarray analysis provided information regarding relative gene expression in UCB MSCs and HCECs. MSCs attached to damaged, but not intact, corneal endothelium in ex vivo corneal wounds. The morphology of MSCs was consistently altered when cells were grown in the presence of LECCM. In tissue culture and in ex vivo corneal wounds, UCB MSC treated with LECCM were elongated and formed parallel sheets of closely apposed cells. In both tissue culture and ex vivo corneal endothelial wounds, ZO1 and N-cadherin localized mainly to the cytoplasm of UCB MSCs in the presence of MSCBM. However, both proteins localized to cell borders when UCB MSCs were grown in either LECBM or LECCM. This localization was lost when extracellular calcium levels were reduced by treatment with EGTA. A second microarray analysis showed that, when UCB MSCs were grown in LECCM instead of LECBM, the relative expression of a subset of genes markedly differed, suggestive of a more HCEC-like phenotype.
Results indicate that UCB MSCs are able to "home" to areas of injured corneal endothelium and that the phenotype of UCB MSCs can be altered toward that of HCEC-like cells. Further study is needed to identify the specific microenvironmental conditions that would permit tissue engineering of UCB MSCs to replace damaged or diseased corneal endothelium.
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