Prognostic significance of DNA cytometry in cutaneous malignant lymphomas.

The current classification of cutaneous malignant lymphomas (ML) into low-grade and high-grade lymphomas was found to be of limited reproducibility and permitted only a rough prediction about outcome. With this in mind, the relationship between nuclear DNA content and both prognosis and histologic grading according to the Kiel classification was evaluated on Feulgen-stained imprint specimens. In all, 49 cases of malignant non-Hodgkin's lymphoma, primary of the skin or with an involvement of the skin as one of the first symptoms, were studied using a computerized high-resolution image analysis system. The 2c deviation index (2cDI), which reflects the variation of the nuclear DNA values around the normal diploid peak, was found to be the best prognostically relevant criterion. Using the 2cDI, a significant discrimination (P less than 0.001 in the U test) between low-grade and high-grade ML was achieved. The prognostic benefit of the 2cDI was well documented by a significant inverse correlation between the 2cDI and the period of time until the patients progressed at least into one higher stage or died of lymphoma (r equals -0.63, P less than 0.05). In addition, the 2cDI enabled prognosis of the course of disease. In the group with low 2cDI values (2cDI, less than 0.5), no progression of the disease was observed after 1 year. In the groups presenting with a 2cDI between 0.5 and 1.0 and higher than 1.0, a progression was found in 57% and 64% of the cases studied, respectively. In conclusion, these measurements indicate that the determination of DNA distribution patterns in imprint specimens allows a precise and objective prognostic evaluation of cutaneous ML

Single-walled carbon nanotubes: Induced decomposition of peroxides and non-covalent encapsulation into water-soluble PEG-eggs

This thesis presents two studies aimed of furthering the understanding of single-walled carbon nanotube (SWNT) chemistry for potential applications in composite and biological systems. In composite systems, SWNTs are used as structural members, and bis-acyl peroxides are frequently used as reaction initiators to cure the surrounding matrix. The behavior of the peroxide is often critical to the performance of the final composite. In this study, SWNTs are shown to induce the decomposition of a series of bis-acyl peroxides by single electron transfer. Four bis-acyl peroxides are evaluated for decomposition rate in the presence of SWNTs via iodometry. The resulting SWNTs are analyzed for functionalization by Raman microscopy and X-ray Photoelectron Spectroscopy (XPS). Benzoyl peroxide (BP), p-methoxybenzoyl peroxide (pMBP), phthaloyl peroxide (PhP), and trifluoroacetyl peroxide (TFAP) have known decomposition characteristics and known sensitivities to electron sources. This study demonstrates that all four peroxides undergo induced decomposition in the presence of SWNTs. Of the four, phthaloyl peroxide exhibits the greatest increase, followed by TFAP, BP, and pMBP. This study also demonstrates that all but TFAP functionalize the SWNTs. The decomposition data may be used to design improved composite systems. In aqueous solution, the ability of SWNTs to heat up upon exposure to radiofrequency energy gives them potential uses in biological systems. SWNTs are not soluble alone in aqueous solution, so one approach is to use amphiphilic triblock copolymers to capture and isolate SWNTs in water. This study addresses the difficulties encountered in synthesizing these polymers reproducibly and controllably. Presented here are modifications to the Atom Transfer Radical Polymerization (ATRP) method that not only enable the reproducible synthesis of these triblocks, but also enable them to be made in a highly controlled manner with specific block lengths. The SWNTs encapsulated by the polymers made through this new approach are shown not only to retain their fluorescence but also to demonstrate fluorescence on par with the best surfactants in current use. These structures are expected to provide a new entry into the use of nonfunctionalized SWNTs in biological systems such as radiofrequency heating for the destruction of cancer cells

The ATAC Acetyltransferase Complex Coordinates MAP Kinases to Regulate JNK Target Genes

SummaryIn response to extracellular cues, signal transduction activates downstream transcription factors like c-Jun to induce expression of target genes. We demonstrate that the ATAC (Ada two A containing) histone acetyltransferase (HAT) complex serves as a transcriptional cofactor for c-Jun at the Jun N-terminal kinase (JNK) target genes Jra and chickadee. ATAC subunits are required for c-Jun occupancy of these genes and for H4K16 acetylation at the Jra enhancer, promoter, and transcribed sequences. Under conditions of osmotic stress, ATAC colocalizes with c-Jun, recruits the upstream kinases Misshapen, MKK4, and JNK, and suppresses further activation of JNK. Relocalization of these MAPKs and suppression of JNK activation by ATAC are dependent on the CG10238 subunit of ATAC. Thus, ATAC governs the transcriptional response to MAP kinase signaling by serving as both a coactivator of transcription and as a suppressor of upstream signaling

FUSION OF 3D POINT CLOUDS WITH TIR IMAGES FOR INDOOR SCENE RECONSTRUCTION

Obtaining accurate 3D descriptions in the thermal infrared (TIR) is a quite challenging task due to the low geometric resolutions of TIR cameras and the low number of strong features in TIR images. Combining the radiometric information of the thermal infrared with 3D data from another sensor is able to overcome most of the limitations in the 3D geometric accuracy. In case of dynamic scenes with moving objects or a moving sensor system, a combination with RGB cameras and profile laserscanners is suitable. As a laserscanner is an active sensor in the visible red or near infrared (NIR) and the thermal infrared camera captures the radiation emitted by the objects in the observed scene, the combination of these two sensors for close range applications are independent from external illumination or textures in the scene. This contribution focusses on the fusion of point clouds from terrestrial laserscanners and RGB cameras with images from thermal infrared mounted together on a robot for indoor 3D reconstruction. The system is geometrical calibrated including the lever arm between the different sensors. As the field of view is different for the sensors, the different sensors record the same scene points not exactly at the same time. Thus, the 3D scene points of the laserscanner and the photogrammetric point cloud from the RGB camera have to be synchronized before point cloud fusion and adding the thermal channel to the 3D points

Primary and malignant cholangiocytes undergo CD40 mediated Fas dependent Apoptosis, but are insensitive to direct activation with exogenous fas ligand

Introduction Cholangiocarcinoma is a rare malignancy of the biliary tract, the incidence of which is rising, but the pathogenesis of which remains uncertain. No common genetic defects have been described but it is accepted that chronic inflammation is an important contributing factor. We have shown that primary human cholangiocyte and hepatocyte survival is tightly regulated via co-operative interactions between two tumour necrosis family (TNF) receptor family members; CD40 and Fas (CD95). Functional deficiency of CD154, the ligand for CD40, leads to a failure of clearance of biliary tract infections and a predisposition to cholangiocarcinoma implying a direct link between TNF receptor-mediated apoptosis and the development of cholangiocarcinoma. Aims To determine whether malignant cholangiocytes display defects in CD40 mediated apoptosis. By comparing CD40 and Fas-mediated apoptosis and intracellular signalling in primary human cholangiocytes and three cholangiocyte cell lines. Results Primary cholangiocytes and cholangiocyte cell lines were relatively insensitive to direct Fas-mediated killing with exogenous FasL when compared with Jurkat cells, which readily underwent Fas-mediated apoptosis, but were extremely sensitive to CD154 stimulation. The sensitivity of cells to CD40 activation was similar in magnitude in both primary and malignant cells and was STAT-3 and AP-1 dependent in both. Conclusions 1) Both primary and malignant cholangiocytes are relatively resistant to Fas–mediated killing but show exquisite sensitivity to CD154, suggesting that the CD40 pathway is intact and fully functional in both primary and malignant cholangiocytes 2) The relative insensitivity of cholangiocytes to Fas activation demonstrates the importance of CD40 augmentation of Fas dependent death in these cells. Agonistic therapies which target CD40 and associated intracellular signalling pathways may be effective in promoting apoptosis of malignant cholangiocytes

Identification and functional characterization of muscle satellite cells in Drosophila

Work on genetic model systems such as Drosophila and mouse has shown that the fundamental mechanisms of myogenesis are remarkably similar in vertebrates and invertebrates. Strikingly, however, satellite cells, the adult muscle stem cells that are essential for the regeneration of damaged muscles in vertebrates, have not been reported in invertebrates. In this study, we show that lineal descendants of muscle stem cells are present in adult muscle of Drosophila as small, unfused cells observed at the surface and in close proximity to the mature muscle fibers. Normally quiescent, following muscle fiber injury, we show that these cells express Zfh1 and engage in Notch-Delta-dependent proliferative activity and generate lineal descendant populations, which fuse with the injured muscle fiber. In view of strikingly similar morphological and functional features, we consider these novel cells to be the Drosophila equivalent of vertebrate muscle satellite cells

R-spondin1 regulates muscle progenitor cell differentiation and fusion through dual regulation of canonical and non-canonical Wnt signaling pathways

Orchestration of numerous molecular pathways is required to deliver stem cells mediated tissue regeneration. As such, mechanisms controlling one aspect of regeneration are often antagonistic to others. Much attention has focused on Wntmediated signalings as this family is involved in many important steps in mammalian regeneration. In many cell types, the R-spondin (Rspo) family of secreted proteins acts as potent activators of the canonical Wnt/β-catenin pathway. Here, we identify Rspo1 as a mediator of skeletal muscle tissue repair. First, we show that Rspo1-null muscles do not display any abnormalities at the basal level. However deletion of Rspo1 results in global alteration of muscle regeneration kinetics following acute injury. We found that muscle progenitor cells lacking Rspo1 show delayed differentiation. Transcriptome analysis demonstrated that Rspo1 is required for the activation of Wnt/β-catenin target genes in muscle cells. Furthermore, muscle cells lacking Rspo1 have a fusion phenotype leading to larger myotubes containing supernumerary nuclei both in vitro and in vivo. We found the increase in muscle fusion was dependent on downregulation of Wnt/β-catenin and up-regulation of non-canonical Wnt7a/Fzd7/Rac1 signaling. We conclude that reciprocal control of canonical and non-canonical Wnt signaling pathways by Rspo1 in muscle stem cell progeny is a key step ensuring normal tissue architecture restoration following acute damage

A formin-nucleated actin aster concentrates cell wall hydrolases for cell fusion in fission yeast.

Cell-cell fusion is essential for fertilization. For fusion of walled cells, the cell wall must be degraded at a precise location but maintained in surrounding regions to protect against lysis. In fission yeast cells, the formin Fus1, which nucleates linear actin filaments, is essential for this process. In this paper, we show that this formin organizes a specific actin structure-the actin fusion focus. Structured illumination microscopy and live-cell imaging of Fus1, actin, and type V myosins revealed an aster of actin filaments whose barbed ends are focalized near the plasma membrane. Focalization requires Fus1 and type V myosins and happens asynchronously always in the M cell first. Type V myosins are essential for fusion and concentrate cell wall hydrolases, but not cell wall synthases, at the fusion focus. Thus, the fusion focus focalizes cell wall dissolution within a broader cell wall synthesis zone to shift from cell growth to cell fusion

Comparison of Francisella tularensis genomes reveals evolutionary events associated with the emergence of human pathogenic strains

.Sequencing of the non-pathogenic Francisella tularensis sub-species novicida U112, and comparison with two pathogenic sub-species, provides insights into the evolution of pathogenicity in these species