932 research outputs found
The Ostrogoths in Italy
The paper intends to establish a summary of the policies of Theoderic, of his
achievements and his failures, as well as the basic principies of his politics,
which were far from negative to the evolution of his kingdom in Italy
The Ostrogoths in Italy
The paper intends to establish a summary of the policies of Theoderic, of his
achievements and his failures, as well as the basic principies of his politics,
which were far from negative to the evolution of his kingdom in Italy
Transcriptional inhibition of type I collagen gene expression in scleroderma fibroblasts by the antineoplastic drug ecteinascidin 743.
We previously showed that COL1A1 expression is up-regulated at the transcriptional level in systemic sclerosis (SSc) fibroblasts and that the CCAAT-binding factor (CBF) is involved in this increased expression. Ecteinascidin 743 (ET-743) is a chemotherapeutic agent that binds with sequence specificity to the minor groove of DNA and inhibits CBF-mediated transcriptional activation of numerous genes. Therefore, we examined the effects of ET-743 on the increased COL1A1 expression in SSc fibroblasts. The drug caused a potent and dose-dependent inhibition of type I collagen biosynthesis, which reached 70-90% at 700 pM without affecting cell viability. The same drug concentration caused 60-80% reduction in COL1A1 mRNA levels. The stability of the corresponding transcripts was not affected. In vitro nuclear transcription assays demonstrated a 54% down-regulation of COL1A1 transcription. Transient transfections with COL1A1 promoter constructs containing the specific CBF binding sequence into SSc cells previously treated with 700 pM ET-743 failed to show an effect on COL1A1 promoter activity. Furthermore, ET-743 did not affect the binding of CBF or Sp1 transcription factors to their cognate COL1A1 elements. However, treatment with 700 pM ET-743 of stably transfected NIH 3T3 cells expressing a human type II procollagen gene under the control of the human COL1A1 promoter caused a greater than 50% reduction in the production of type II procollagen and a similar decrease in the corresponding type II procollagen transcripts. These results indicate that ET-743 is a potent inhibitor of COL1A1 transcription. However, this effect cannot be explained by a direct effect on CBF binding to the COL1A1 promoter. Although the exact mechanisms responsible for the transcriptional inhibition of COL1A1 by ET-743 are not apparent, our observations suggest that the drug may be an effective agent to decrease collagen overproduction in SSc and other fibrotic diseases
: Teoderico l'Amalo e la civiltà romana
The ciuilitas of Thedoric not only can be appreciated in his desire to restore the ancient buildings and in the obvious refinement of the gifts he gave to Clodoveus and Gundobadus but also in his consideration towards the individual conscience of his subjects. His attitude in the religious ambitus is one of moderation and tolerance which converts him almost into a modern iluminated spirit. The cohesive force between the elements which compose his kingdom had to be based on the maintenance of the Law. This was his main preoccupation: with this in mind he gave orders to generals, praised the Senate, remonstrated all those who broke the laws, exalted those who worked in their keeping and punished the lawbreakers. The principal aim of his government was to maintain the ciuilitas. For this reason he favoured actions such as mixed marriages which helped the Goths enter into the romanitas and encouraged the implantation of the Roman civilization amongst the Gepids. That was the signiHcation he gave to the wars carried out in the Gallia in 508. This image of him was real and he was described in an inscription as custos libertatis et propagator Romani nominis
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Potential of Human Umbilical Cord Blood Mesenchymal Stem Cells to Heal Damaged Corneal Endothelium
Purpose: 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. Methods: 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. Results: 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. Conclusions: 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
Role of protein kinase C-delta in the regulation of collagen gene expression in scleroderma fibroblasts
Working with cultured dermal fibroblasts derived from control individuals and patients with systemic sclerosis (SSc), we have examined the effects of protein kinase C-delta (PKC-delta) on type I collagen biosynthesis and steady-state levels of COL1A1 and COL3A1 mRNAs. Rottlerin, a specific inhibitor of PKC-delta, exerted a powerful, dose-dependent inhibition of type I and type III collagen gene expression in normal and SSc cells. Optimal rottlerin concentrations caused a 70-90% inhibition of type I collagen production, a \u3e80% reduction in COL1A1 mRNA, and a \u3e70% reduction in COL3A1 mRNA in both cell types. In vitro nuclear transcription assays and transient transfections with COL1A1 promoter deletion constructs demonstrated that rottlerin profoundly reduced COL1A1 transcription and that this effect required a 129-bp promoter region encompassing nucleotides -804 to -675. This COL1A1 segment imparted rottlerin sensitivity to a heterologous promoter. Cotransfections of COL1A1 promoter constructs with a dominant-negative PKC-delta expression plasmid showed that suppression of this kinase silenced COL1A1 promoter activity. The results indicate that PKC-delta participates in the upregulation of collagen gene transcription in SSc and suggest that treatment with PKC-delta inhibitors could suppress fibrosis in this disease
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Self-Assembled Matrix by Umbilical Cord Stem Cells
Corneal integrity is critical for vision. Corneal wounds frequently heal with scarring that impairs vision. Recently, human umbilical cord mesenchymal stem cells (cord stem cells) have been investigated for tissue engineering and therapy due to their availability and differentiation potential. In this study, we used cord stem cells in a 3-dimensional (3D) stroma-like model to observe extracellular matrix organization, with human corneal fibroblasts acting as a control. For 4 weeks, the cells were stimulated with a stable Vitamin C (VitC) derivative ±TGF-β1. After 4 weeks, the mean thickness of the constructs was ∼30 μm; however, cord stem cell constructs had 50% less cells per unit volume, indicating the formation of a dense matrix. We found minimal change in decorin and lumican mRNA, and a significant increase in perlecan mRNA in the presence of TGF-β1. Keratocan on the other hand decreased with TGF-β1 in both cell lineages. With both cell types, the constructs possessed aligned collagen fibrils and associated glycosaminoglycans. Fibril diameters did not change with TGF-β1 stimulation or cell lineage; however, highly sulfated glycosaminoglycans associated with the collagen fibrils significantly increased with TGF-β1. Overall, we have shown that cord stem cells can secrete their own extracellular matrix and promote the deposition and sulfation of various proteoglycans. Furthermore, these cells are at least comparable to commonly used corneal fibroblasts and present an alternative for the 3D in vitro tissue engineered model
Aging measurements on triple-GEM detectors operated with CF4-based gas mixtures
We present the results of a global irradiation test of full size triple-GEM detectors operated with CF 4 -based gas mixtures. This study has been performed in the framework of an R&D activity on detectors for the innermost region of the first muon station of the LHCb experiment. The prototypes have been irradiated at the Calliope facility of the ENEA-Casaccia with a high intensity 1.25 MeV γ 60 Co source. After the irradiation test the detectors performances have been measured with X-rays and with a 3 GeV pion beam at CERN. A SEM analysis on several samples of the detectors has been performed to complete the understanding of the physical processes occurring in a GEM detector during a strong irradiation
Human Nidogen Gene: Structural and Functional Characterization of the 5'-Flanking Region
Nidogen is a sulfated multifunctional glycoprotein present in basement membranes. In this study, we have cloned the 5'-flanking region of the human nidogen gene. Initially, an ∼ 35-kb DNA clone (NCos4) was isolated from a human cosmid genomic library. Southern hybridization of EcoRI-digested NCos4 allowed isolation of a 3.7-kb fragment, which was shown to contain a portion of intron 1, the entire exon 1, and ∼ 0.9 kb of 5'-flanking sequences of the nidogen gene. Nucleotide sequencing of the 5'-flanking DNA revealed the presence of two canonic CCAAT consensus sequences in the antisense strand and a potential variant of the TATA motif, TATTT, in the sense strand. One putative AP-2 and six putative SP1 binding sites were also present. To test the functional promoter activity of the 5'-flanking genomic DNA, two nidogen promoter/CAT reporter gene constructs, with the promoter segment spanning from –864 to –1 and from –534 to –1, respectively, were developed and analyzed in transient transfections of human and mouse cell cultures. Both constructs showed clearly detectable promoter activity, and the activity of the larger construct could be up-regulated by 12-O-tetradecanoyl phorbol 13-acetate up to 2.5 times. The results indicate that the nidogen promoter/CAT gene constructs developed in this study provide a means to examine the transcriptional regulation of nidogen gene expression in human diseases of the basement membrane zone
Production and performance of LHCb triple-GEM detectors equipped with the dedicated CARDIAC-GEM front-end electronics
The production of the triple-GEM detectors for the innermost region of the first muon station of the LHCb experiment has started in February 2006, and is foreseen to be completed by the end of July. The final design of the detector and the construction procedure and tools, as well as the quality controls are defined. The performances of each detector, composed by two triple-GEM chambers equipped with dedicated CARDIAC-GEM front-end electronics, are studied with a cosmic ray telescope. The cosmic ray telescope has been set up including all the final off-detector components
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