A simple and efficient method for producing multitransgenic animals is required for medical and veterinary applications. Sperm-mediated gene transfer (SMGT) is an effective method for introducing ...multiple genes into pigs (Sus, Sus scrofa). The major benefits of this technique are the high efficiency, low cost, and ease of use compared with that of other methods: Sperm-mediated gene transfer does not require embryo handling or expensive equipment. The aim of this study was to investigate the influence of SMGT treatment and exogenous DNA uptake on sperm quality. Even after a coincubation with a 20-fold larger amount (100
μg/mL) of DNA than usual (5
μg/mL), sperm quality parameters were not significantly affected, confirming the hypothesis that the SMGT protocol itself or the amount of bound DNA do not compromise the possibility of an extended employment of SMGT. More importantly, we found that semen used for in vitro fertilization 24
h after DNA uptake gave good cleavage (60% vs. 58%, treated vs. control) and developmental rates definitely positive (41% vs. 48%, treated vs. control). These good results are connected to a competitive efficiency of transformation (62%) due to the numerous improvements in SMGT technique. We demonstrate that SMGT-treated spermatozoa retain good quality and fertilization potential for at least 24
h, expanding the possibility to apply transgenesis in field conditions in swine, where the greatest hurdles are fertilization timing and plain procedure.
Broadly defined, nanoscale materials are substances in which at least one critical dimension is less than 100
nm. Nanoscale materials are employed in several industrial applications as well as in ...biology and medicine. Despite their wide use, very little research has been carried out on the potential toxicity of nanoparticles. For this reason, we report on a molecular approach in nanotoxicology research. Using the differential display technique, we focused our attention on mRNA expression in a BALB3T3 A31-1-1 cell line that was not exposed and exposed for 72
h to 1
μM of cobalt microparticles (Co-μ), nanoparticles (Co-nano), and ions. In the experiments, we obtained 10 differentially expressed sequences. These genes represent candidate biomarkers capable of indicating specific cellular effects after Co-nano exposure. In addition, our results show that treatment with Co-nano somehow activates cellular pathways of defense and repair mechanisms. It is also evident that molecular techniques are valuable tools in nanotoxicology research, where they will certainly find wide use.
A wide investigation of the synthetic analogue of tetrahedrite, Cu12Sb4S13, has been performed by a combination of several techniques, magnetisation and differential scanning calorimetric ...measurements, cw, and pulsed EPR spectroscopy, to obtain complementary information about the presence and the distribution of Cu(II). The high temperature susceptibility of the sample accounts for two Cu(II) per formula unit, in agreement with the charge balance. However, strong antiferromagnetic interactions, observed even at room temperature, are associated with a transition at 83(3) K. At lower temperatures a residual susceptibility is observed. At 4.2 K ESEEM experiments enabled observation of the chemical environment of the residual paramagnetic species. Cu(II) was found randomly distributed in the M(1) site. The statistical presence of nearest neighbouring Cu(II) ions justify the observed antiferromagnetic interactions and transition. Nevertheless, isolated paramagnetic ions have been determined below the Néel temperature: they are mainly located near the surface of the grains. A colour centre, previously observed in natural samples, has been also identified.
Background and aim: Inflammation has been extensively implicated in the pathogenesis of Alzheimer’s disease (AD). Although there is evidence of a key role for cytokines in neuroinflammation ...processes, so far the proinflammatory cytokine interleukin (IL)-18 has not been associated with AD. The aim of this study was to investigate the impact of two polymorphisms of the human IL-18 gene promoter at positions −607 (C/A) and −137 (G/C) on both susceptibility to and progression of AD. Results: The results revealed that the genotype distribution of the −607 (C/A) polymorphism was different between patients with AD and control subjects (χ2 = 7.99, df = 2, p = 0.0184). In particular, carriers of the CC genotype were at increased risk of developing AD (OR 2.33; 95% CI 1.29 to 4.22; p = 0.0052). The observed genotypes were in Hardy–Weinberg equilibrium, as for the −607 polymorphism, whereas the −137 polymorphism appeared in Hardy–Weinberg disequilibrium only in the patient group (p = 0.0061). Finally, in a 2 year follow-up study, the −137 CC genotype was strongly and specifically associated with a faster cognitive decline (F = 4.024; df = 4,192; p = 0.0037 for time by IL-18 −137 G/C group interaction) with no interaction effect with the apolipoprotein E ε4/non-ε4 allele presence. Conclusion: As IL-18 cytokine promoter gene polymorphisms have been previously described to have functional consequences on IL-18 expression, it is possible that individuals with a prevalent IL-18 gene variant have a dysregulated immune response, suggesting that IL-18 mediated immune mechanisms may play a crucial role in AD.
We report the observation of a very high energy gamma -ray source whose position is coincident with HESS J1841-055. This source has been observed for 4.5 years by the ARGO-YBJ experiment from 2007 ...November to 2012 July. Its emission is detected with a statistical significance of 5.3 standard deviations. Parameterizing the source shape with a two-dimensional Gaussian function, we estimate an extension (ProQuest: Formulae and/or non-USASCII text omitted), which is consistent with the HESS measurement. The observed energy spectrum is dN/dE = (9.0 + or - 1.6) x 10 super(-13)(E/5 TeV) super(-2.32+ or -0.23) photons cm super(-2) s super(-1) TeV super(-1), in the energy range 0.9-50 TeV. The integral gamma -ray flux above 1 TeV is 1.3 + or - 0.4 Crab, which is 3.2 + or - 1.0 times the flux derived by HESS. The differences in the flux determination between HESS and ARGO-YBJ and possible counterparts at other wavelengths are discussed.
The energy of atmospheric neutrinos detected by MACRO was estimated using multiple Coulomb scattering of upward throughgoing muons. This analysis allows a test of atmospheric neutrino oscillations, ...relying on the distortion of the muon energy distribution. These results have been combined with those coming from the upward throughgoing muon angular distribution only. Both analyses are independent of the neutrino flux normalization and provide strong evidence, above the 4σ level, in favour of neutrino oscillations.
IntroductionAcute T-cell lymphoblastic leukaemia (T-ALL) is a childhood cancer, characterised by infiltration of immature T-cells in bone marrow. Notch hyperactivation is a major driver of T-ALL ...development where CXCL12/CXCR4 axis plays an important role in T-ALL maintenance. In thymus the lympho-stromal communication drives progressive maturation of T-cells. Notch receptors regulate T-cell fate choices, dominating early steps of thymocyte maturation. In T-cell differentiation, Notch3, in association with pre-TCR and chemochine receptor CXCR4, govern the transition from double negative (DN) to double positive (DP) thymocytes. Previously, our laboratory demonstrated the lymphomagenic potential of Notch3 by creating a transgenic mouse model (N3-ICtg), characterised by the constitutive activation of the intracellular domain (IC) of Notch3 receptor (N3-IC) in immature thymocytes. In order to investigate the oncogenic cross-talk between Notch3 and CXCR4 in T-ALL progression, we analysed DP T-cells in different lymphoid compartments of N3-ICtg mice.Material and methodsFreshly isolated cells from thymus, blood and bone marrow of N3-ICtg and WT mice were analysed by flow cytometry in order to verify the presence of DP T-cells and their cell-surface expression of CXCR4 and Notch3 receptors. Experiments in TALL1, a human T-ALL leukemic CD3+/CD4+/CD8+ cell line characterised by the activation of Notch3 and high expression of CXCR4, were also performed. TALL1 cells were treated with γ-secretase inhibitor (GSI) or their gene expression of Notch3 was silenced and then analysed by flow cytometry, RT-PCR and western blot. Statistical interpretation of the results was performed.Results and discussionsDP-gated thymocytes obtained by N3-ICtg mice have shown a high co-expression of Notch3 and CXCR4 and a high migratory ability induced by SDF-1. An anomalous percentage representation of these DP T-cells at different ages in circulating blood, spleen and bone morrow may suggest an interaction between CXCR4 and Notch3 in T-ALL cell propagation. Experiments in human TALL1 cell line with Notch3 targeted inhibition suggest a modulated expression of CXCR4 through a β-arrestin1-mediated mechanism. CXCR4-antagonists treatment will further elucidate the molecular crosstalk between the two receptors.ConclusionNotch3 abnormal pathway, through boosting the expression of CXCR4 on cell-surface, may play a role in DP T-cells egress from thymus, and define a possible mechanism of ’pre-leukemic-cells’ dissemination.
In this paper we compute rest-frame extinctions for the afterglows of a sample of gamma-ray bursts complete in redshift. The selection criteria of the sample are based on observational high-energy ...parameters of the prompt emission and therefore our sample should not be biased against dusty sight-lines. It is therefore expected that our inferences hold for the general population of gamma-ray bursts. Our main result is that the optical/near-infrared extinction of gamma-ray burst afterglows in our sample does not follow a single distribution. 87% of the events are absorbed by less than 2 mag, and 50% suffer from less than 0.3-0.4 mag extinction. The remaining 13% of the afterglows are highly absorbed. The true percentage of gamma-ray burst afterglows showing high absorption could be even higher since a fair fraction of the events without reliable redshift measurement are probably part of this class. These events may be due to highly dusty molecular clouds/star forming regions associated with the gamma-ray burst progenitor or along the afterglow line of sight, and/or to massive dusty host galaxies. No clear evolution in the dust extinction properties is evident within the redshift range of our sample, although the largest extinctions are at z~1.5-2, close to the expected peak of the star formation rate. Those events classified as dark are characterized, on average, by a higher extinction than typical events in the sample. A correlation between optical/near-infrared extinction and hydrogen-equivalent column density based on X-ray studies is shown although the observed NH appears to be well in excess compared to those observed in the Local Group. Dust extinction does not seem to correlate with GRB energetics or luminosity.
We present results of a Monte Carlo study of the sensitivity of the planned IceCube detector to predicted fluxes of muon neutrinos at TeV to PeV energies. A complete simulation of the detector and ...data analysis is used to study the detector’s capability to search for muon neutrinos from potential sources such as active galaxies and gamma-ray bursts (GRBs). We study the effective area and the angular resolution of the detector as a function of muon energy and angle of incidence. We present detailed calculations of the sensitivity of the detector to both diffuse and pointlike neutrino fluxes, including an assessment of the sensitivity to neutrinos detected in coincidence with GRB observations. After three years of data taking, IceCube will be able to detect a point-source flux of
E
ν
2×d
N
ν
/d
E
ν
=7×10
−9 cm
−2
s
−1
GeV at a 5
σ significance, or, in the absence of a signal, place a 90% c.l. limit at a level of
E
ν
2×d
N
ν
/d
E
ν
=2×10
−9 cm
−2
s
−1
GeV. A diffuse
E
−2 flux would be detectable at a minimum strength of
E
ν
2×d
N
ν
/d
E
ν
=10
−8 cm
−2
s
−1
sr
−1
GeV. A GRB model following the formulation of Waxman and Bahcall would result in a 5
σ effect after the observation of 200 bursts in coincidence with satellite observations of the gamma rays.
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