2,908 research outputs found

    Geometry of the p-Adic Special Orthogonal Group SO(3)p

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    We derive explicitly the structural properties of the p-adic special orthogonal groups in dimension three, for all primes p, and, along the way, the two-dimensional case. In particular, starting from the unique definite quadratic form in three dimensions (up to linear equivalence and rescaling), we show that every element of SO(3)p is a rotation around an axis. An important part of the analysis is the classification of all definite forms in two dimensions, yielding a description of the rotation subgroups around any fixed axis, which all turn out to be abelian and parametrised naturally by the projective line. Furthermore, we find that for odd primes p, the entire group SO(3)p admits a representation in terms of Cardano (aka nautical) angles of rotations around the reference axes, in close analogy to the real orthogonal case. However, this works only for certain orderings of the product of rotations around the coordinate axes, depending on the prime; furthermore, there is no general Euler angle decomposition. For p = 2, no Euler or Cardano decomposition exists

    Lymphoid EVA1 Expression Is Required for DN1-DN3 Thymocytes Transition

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    Background: Thymus organogenesis and T lymphocyte development are accomplished together during fetal life. Proper development and maintenance of thymus architecture depend on signals generated by a sustained crosstalk between developing thymocytes and stromal elements. Any maturation impairment occurring in either cellular component leads to an aberrant thymic development. Gene expression occurring during T lymphocyte differentiation must be coordinated in a spatio-temporal fashion; one way in which this is achieved is through the regulation by cell-cell adhesion and interactions. Principal Findings: We examined the role played by Epithelial V-like Antigen 1 (EVA1), an Ig adhesion molecule expressed on thymus epithelial cells (TEC) and immature thymocytes, in T cell development by employing RNA interference in vitro and in vivo models. Fetal liver derived haematopoietic progenitors depleted of Eva1, displayed a delayed DN1-DN3 transition and failed to generate CD4CD8 double positive T cells in OP9-DL1 coculture system. In addition, we could observe a coordinated Eva1 up-regulation in stromal and haematopoietic cells in coculture control experiments, suggesting a possible EVA1 involvement in TEC-haematopoietic cells crosstalk mechanisms. Similarly, Rag2-cc double knock out mice, transplanted with Eva1 depleted haematopoietic progenitors displayed a 10-fold reduction in thymus reconstitution and a time delayed thymocytes maturation compared to controls. Conclusions: Our findings show that modulation of Eva1 expression in thymocytes is crucial for lymphocyte physiological developmental progression and stromal differentiation

    Altered glycosylation profile of purified plasma ACT from Alzheimer’s disease

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    Background Alzheimer\u2019s disease (AD) is one of the most frequent cause of neurodegenerative disorder in the elderly. Inflammation has been implicated in brain degenerative processes and peripheral markers of brain AD related impairment would be useful. Plasma levels of alpha-1-antichymotrypsin (ACT), an acute phase protein and a secondary component of amyloid plaques, are often increased in AD patients and high blood ACT levels correlate with progressive cognitive deterioration. During inflammatory responses changes in the micro-heterogeneity of ACT sugar chains have been described. Methods N-Glycanase digestion from Flavobacterium meningosepticum (PNGase F) was performed on both native and denatured purified ACT condition and resolved to Western blot with the purpose to revealed the ACT de-glycosylation pattern. Further characterization of the ACT glycan profile was obtained by a glycoarray; each lectin group in the assay specifically recognizes one or two glycans/epitopes. Lectin-bound ACT produced a glyco-fingerprint and mayor differences between AD and controls samples were assessed by a specific algorithms. Results Western blot analysis of purified ACT after PNGase F treatment and analysis of sugar composition of ACT showed significantly difference in \u201cglyco-fingerprints\u201d patterns from controls (CTR) and AD; ACT from AD showing significantly reduced levels of sialic acid. A difference in terminal GlcNac residues appeared to be related with progressive cognitive deterioration. Conclusions Low content of terminal GlcNac and sialic acid in peripheral ACT in AD patients suggests that a different pattern of glycosylation might be a marker of brain inflammation. Moreover ACT glycosylation analysis could be used to predict AD clinical progression and used in clinical trials as surrogate marker of clinical efficacy

    Curcumin blocks autophagy and activates apoptosis of malignant mesothelioma cell lines and increases the survival of mice intraperitoneally transplanted with a malignant mesothelioma cell line

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    Malignant mesothelioma (MM) is a primary tumor arising from the serous membranes. The resistance of MM patients to conventional therapies, and the poor patients' survival, encouraged the identification of molecular targets for MM treatment. Curcumin (CUR) is a "multifunctional drug". We explored the in vitro effects of CUR on cell proliferation, cell cycle regulation, pro-survival signaling pathways, apoptosis, autophagy of human (MM-B1, H-Meso-1, MM-F1), and mouse (#40a) MM cells. In addition, we evaluated the in vivo anti-tumor activities of CUR in C57BL/6 mice intraperitoneally transplanted with #40a cells forming ascites.CUR in vitro inhibited MM cells survival in a dose- and time-dependent manner and increased reactive oxygen species'intracellular production and induced DNA damage. CUR triggered autophagic flux, but the process was then blocked and was coincident with caspase 8 activation which activates apoptosis. CUR-mediated apoptosis was supported by the increase of Bax/Bcl-2 ratio, increase of p53 expression, activation of caspase 9, cleavage of PARP-1, increase of the percentage of cells in the sub G1 phase which was reduced (MM-F1 and #40a) or abolished (MM-B1 and H-Meso-1) after MM cells incubation with the apoptosis inhibitor Z-VAD-FMK. CUR treatment stimulated the phosphorylation of ERK1/2 and p38 MAPK, inhibited that of p54 JNK and AKT, increased c-Jun expression and phosphorylation and prevented NF-κB nuclear translocation. Intraperitoneal administration of CUR increased the median survival of C57BL/6 mice intraperitoneally transplanted with #40a cells and reduced the risk of developing tumors. Our findings may have important implications for the design of MM treatment using CUR

    In Vitro and in vivo anti-tumoral effects of the flavonoid apigenin in malignant mesothelioma

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    Malignant mesothelioma (MM) is a tumor arising from mesothelium. MM patients' survival is poor. The polyphenol 4',5,7,-trihydroxyflavone Apigenin (API) is a "multifunctional drug". Several studies have demonstrated API anti-tumoral effects. However, little is known on the in vitro and in vivo anti-tumoral effects of API in MM. Thus, we analyzed the in vitro effects of API on cell proliferation, cell cycle regulation, pro-survival signaling pathways, apoptosis, and autophagy of human and mouse MM cells. We evaluated the in vivo anti-tumor activities of API in mice transplanted with MM #40a cells forming ascites. API inhibited in vitro MM cells survival, increased reactive oxygen species intracellular production and induced DNA damage. API activated apoptosis but not autophagy. API-induced apoptosis was sustained by the increase of Bax/Bcl-2 ratio, increase of p53 expression, activation of both caspase 9 and caspase 8, cleavage of PARP-1, and increase of the percentage of cells in subG1 phase. API treatment affected the phosphorylation of ERK1/2, JNK and p38 MAPKs in a cell-type specific manner, inhibited AKT phosphorylation, decreased c-Jun expression and phosphorylation, and inhibited NF-κB nuclear translocation. Intraperitoneal administration of API increased the median survival of C57BL/6 mice intraperitoneally transplanted with #40a cells and reduced the risk of tumor growth. Our findings may have important implications for the design of MM treatment using API

    Lung involvement in "stable" undifferentiated connective tissue diseases: a rheumatology perspective

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    Previous studies of the occurrence of interstitial lung disease (ILD) in undifferentiated connective tissue diseases (UCTD) were conducted in patients admitted to Respiratory Medicine Units. The aim of the present prospective study was to investigate lung involvement in UCTD patients admitted to a Rheumatology Unit. Eighty-one consecutive UCTD patients were enrolled in the study. Each patient underwent history and physical examination, routine laboratory investigations, antinuclear antibody (ANA) profiling, B-mode echocardiography, and lung function study according to previously reported methods. Lung high resolution computed tomography (HRCT) was performed in patients who provided informed consent. Six patients (7.4%) had a history of grade II dyspnea. Three of them had a DLCO ranging from 42 to 55% of the predicted value; and a HRCT-documented ILD with a non-specific interstitial pneumonia (NSIP) pattern. Symptoms in the other three patients were due to cardiac disease. None of the 75 asymptomatic patients, had relevant findings at physical examination, 26/75 had a DLCO <80% (<70% in 10 cases). Of these, 3 of the 30 patients who underwent lung HRCT were affected by NSIP-ILD. Six of the 81 enrolled were affected by ILD, which was symptomatic in three patients. A higher percentage of patients had a reduced DLCO. The latter finding may reflect a preradiographic ILD or a preechocardiographic pulmonary vascular disease

    Non-Aβ-dependent factors associated with global cognitive and physical function in alzheimer's disease: a pilot multivariate analysis

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    Recent literature highlights the importance of identifying factors associated with mild cognitive impairment (MCI) and Alzheimer's Disease (AD). Actual validated biomarkers include neuroimaging and cerebrospinal fluid assessments; however, we investigated non-Aβ-dependent factors associated with dementia in 12 MCI and 30 AD patients. Patients were assessed for global cognitive function (Mini-Mental state examination-MMSE), physical function (Physical Performance Test-PPT), exercise capacity (6-min walking test-6MWT), maximal oxygen uptake (VO₂max), brain volume, vascular function (flow-mediated dilation-FMD), inflammatory status (tumor necrosis factor-α ,TNF- α, interleukin-6, -10 and -15) and neurotrophin receptors (p75NTR and Tropomyosin receptor kinase A -TrkA). Baseline multifactorial information was submitted to two separate backward stepwise regression analyses to identify the variables associated with cognitive and physical decline in demented patients. A multivariate regression was then applied to verify the stepwise regression. The results indicated that the combination of 6MWT and VO₂max was associated with both global cognitive and physical function (MMSE = 11.384 + (0.00599 × 6MWT) - (0.235 × VO₂max)); (PPT = 1.848 + (0.0264 × 6MWT) + (19.693 × VO₂max)). These results may offer important information that might help to identify specific targets for therapeutic strategies (NIH Clinical trial identification number NCT03034746)
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