22 research outputs found

    Is Aggressive Surgical Palliation of Proximal Bile Duct Cancer With Involvement of Both Main Hepatic Ducts Worthwhile?

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    The only curative treatment for proximal bile duct cancer with involvement of both main hepatic ducts is liver transplantation. Most patients do not fulfill the requirements for liver transplantation. Our treatment strategy in appropriate cases is palliative tumor resection and reconstruction of the biliary passage by sutureless bilioenteric anastomosis. We have treated 12 patients, 5 in combination with intraluminal and percutaneous radiotherapy. Our results indicate that this strategy leads to effective palliation in some cases provided that only microscopic residual tumor is left in-situ. Our survival times compare favourably with survival after liver transplantation

    Sphingosine-1-phosphate links glycosphingolipid metabolism to neurodegeneration via a calpain-mediated mechanism

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    We have recently reported that the bioactive lipid sphingosine-1-phosphate (S1P), usually signaling proliferation and anti-apoptosis induces neuronal death when generated by sphingosine-kinase2 and when accumulation due to S1P-lyase deficiency occurs. In the present study, we identify the signaling cascade involved in the neurotoxic effect of sphingoid-base phosphates. We demonstrate that the calcium-dependent cysteine protease calpain mediates neurotoxicity by induction of the endoplasmic reticulum stress-specific caspase cascade and activation of cyclin-dependent kinase5 (CDK5). The latter is involved in an abortive reactivation of the cell cycle and also enhances tau phosphorylation. Neuroanatomical studies in the cerebellum document for the first time that indeed neurons with abundant S1P-lyase expression are those, which degenerate first in S1P-lyase-deficient mice. We therefore propose that an impaired metabolism of glycosphingolipids, which are prevalent in the central nervous system, might be linked via S1P, their common catabolic intermediate, to neuronal death

    Determination of nutrient salts by automatic methods both in seawater and brackish water: the phosphate blank

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    9 páginas, 2 tablas, 2 figurasThe main inconvenience in determining nutrients in seawater by automatic methods is simply solved: the preparation of a suitable blank which corrects the effect of the refractive index change on the recorded signal. Two procedures are proposed, one physical (a simple equation to estimate the effect) and the other chemical (removal of the dissolved phosphorus with ferric hydroxide).Support for this work came from CICYT (MAR88-0245 project) and Conselleria de Pesca de la Xunta de GaliciaPeer reviewe

    Microtubule affinity regulating kinase activity in living neurons was examined by a genetically encoded fluorescence resonance energy transfer/fluorescence lifetime imaging-based biosensor: inhibitors with therapeutic potential

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    BACKGROUND: Deregulation of the protein kinase MARK has been linked to Alzheimer disease. - RESULTS: Mark-specific inhibitors and a biosensor are identified. - CONCLUSION: The inhibitors and the biosensor are tools to provide new insights into the role of MARK during polarity establishment and maintenance of neurons. - SIGNIFICANCE: The inhibitors might possess therapeutic potential by interfering with abnormal Tau phosphorylation in Alzheimer disease.Protein kinases of the microtubule affinity regulating kinase (MARK)/Par-1 family play important roles in the establishment of cellular polarity, cell cycle control, and intracellular signal transduction. Disturbance of their function is linked to cancer and brain diseases, e.g. lissencephaly and Alzheimer disease. To understand the biological role of MARK family kinases, we searched for specific inhibitors and a biosensor for MARK activity. A screen of the ChemBioNet library containing ∼18,000 substances yielded several compounds with inhibitory activity in the low micromolar range and capable of inhibiting MARK activity in cultured cells and primary neurons, as judged by MARK-dependent phosphorylation of microtubule-associated proteins and its consequences for microtubule integrity. Four of the compounds share a 9-oxo-9H-acridin-10-yl structure as a basis that will serve as a lead for optimization of inhibition efficiency. To test these inhibitors, we developed a cellular biosensor for MARK activity based on a MARK target sequence attached to the 14-3-3 scaffold protein and linked to enhanced cyan or teal and yellow fluorescent protein as FRET donor and acceptor pairs. Transfection of the teal/yellow fluorescent protein sensor into neurons and imaging by fluorescence lifetime imaging revealed that MARK was particularly active in the axons and growth cones of differentiating neurons

    Hsp90-Tau Complex Reveals Molecular Basis for Specificity in Chaperone Action

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    Protein folding in the cell relies on the orchestrated action of conserved families of molecular chaperones, the Hsp70 and Hsp90 systems. Hsp70 acts early and Hsp90 late in the folding path, yet the molecular basis of this timing is enigmatic, mainly because the substrate specificity of Hsp90 is poorly understood. Here, we obtained a structural model of Hsp90 in complex with its natural disease-associated substrate, the intrinsically disordered Tau protein. Hsp90 binds to a broad region in Tau that includes the aggregation-prone repeats. Complementarily, a 106-Å-long substrate-binding interface in Hsp90 enables many low-affinity contacts. This allows recognition of scattered hydrophobic residues in late folding intermediates that remain after early burial of the Hsp70 sites. Our model resolves the paradox of how Hsp90 specifically selects for late folding intermediates but also for some intrinsically disordered proteins - through the eyes of Hsp90 they look the same. © 2014 Elsevier Inc

    T-Cell Density at the Invasive Margin and Immune Phenotypes Predict Outcome in Vulvar Squamous Cell Cancer

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    Background: Although quantification of tumor infiltrating lymphocytes (TILs) has become of increasing interest in immuno-oncology, only little is known about TILs infiltration in the tumor microenvironment and its predictive value in vulvar cancer. Methods: Immunohistochemistry and automated digital image analysis was applied to measure the densities of CD3+ (DAKO, #IR503) and CD8+ (DAKO, #IR623) TILs at the invasive margin and in the center of 530 vulvar squamous cell cancers. Results: An elevated density of CD3+ T-cell at the invasive margin was significantly associated with low tumor stage (p = 0.0012) and prolonged survival (overall survival [OS] p = 0.0027, progression free survival [PFS] p = 0.024) and was independent from tumor stage, nodal stage, grade, and HPV-status in multivariate analysis (p + cells in the center of the tumor was weaker compared to the invasive margin (OS p = 0.046, PFS p = 0.031) and lacking for CD8+ T-cell densities at any location (p ≥ 0.14 each). Unsupervised clustering of CD3+ and CD8+ T-cell densities identified three major subgroups corresponding to the immune desert (137 patients), immune excluded (220 patients) and immune inflamed phenotypes (133 patients). Survival analysis revealed a particular poor prognosis for the immune desert phenotype for OS (p = 0.0071) and PFS (p = 0.0027). Conclusion: Our data demonstrate a high prognostic value of CD3+ T-cells at the invasive margin and immune phenotypes in vulvar squamous cell cancer
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