350 research outputs found
High One-Dimensional Charge Mobility in Semiconducting Columnar Mesophases of Isocyano-Triphenylene Metal Complexes
ProducciĂłn CientĂficaThis paper reports the synthesis, liquid crystal behavior, and charge-transport properties in the mesophase of isocyano-triphenylene gold, copper, palladium, and platinum complexes [MX(CNR)] (CNR = 2-(6-(4-isocyanophenoxy)hexyloxy)-3,6,7,10,11-pentakisdodecyloxytriphenylene; M = Au, X = Cl, C6F5, C6F4OC10H21, CN; M = Cu, X = Cl), [(ÎĽ-4,4′-C6F4C6F4){Au(CNR)}2], [(ÎĽ-Cl2){Cu(CNR)2}2], and [MX2(CNR)2] (M = Pd, Pt; X = Cl, Br, I, and M = Pt, X = CN). The thermal and electronic properties of these materials are modulated by the metal fragment. The complexes that display columnar mesomorphism are those that support more than one triphenylene per molecule or those that produce a similar effect by dipole–dipole interactions between the metal groups. These circumstances improve the balance of favorable enthalpic interactions versus unfavorable entropic contributions into a columnar stacking. Hybrid inorganic/organic dual columnar mesophases with high SCLC hole mobility along the columnar stacking, above 1 cm2 V–1 s–1, have been found. It is worth noting that the dicyanoplatinum complex displays mesophase phosphorescence based on Pt···Pt interactions.Ministerio de Ciencia e InnovaciĂłn (Proyect CTQ2014-52796-P
Pain management in pediatric day surgery patients at The Maternal and Child Medical Research Center in Mongolia
Temporal multi-omics identifies LRG1 as a vascular niche instructor of metastasis
Metastasis is the primary cause of cancer-related mortality. Tumor cell interactions with cells of the vessel wall are decisive and potentially rate-limiting for metastasis. The molecular nature of this cross-talk is, beyond candidate gene approaches, hitherto poorly understood. Using endothelial cell (EC) bulk and single-cell transcriptomics in combination with serum proteomics, we traced the evolution of the metastatic vascular niche in surgical models of lung metastasis. Temporal multiomics revealed that primary tumors systemically reprogram the body’s vascular endothelium to perturb homeostasis and to precondition the vascular niche for metastatic growth. The vasculature with its enormous surface thereby serves as amplifier of tumor-induced instructive signals. Comparative analysis of lung EC gene expression and secretome identified the transforming growth factor–β (TGFβ) pathway specifier LRG1, leucine-rich alpha-2-glycoprotein 1, as an early instructor of metastasis. In the presence of a primary tumor, ECs systemically up-regulated LRG1 in a signal transducer and activator of transcription 3 (STAT3)–dependent manner. A meta-analysis of retrospective clinical studies revealed a corresponding up-regulation of LRG1 concentrations in the serum of patients with cancer. Functionally, systemic up-regulation of LRG1 promoted metastasis in mice by increasing the number of prometastatic neural/glial antigen 2 (NG2)+ perivascular cells. In turn, genetic deletion of Lrg1 hampered growth of lung metastasis. Postsurgical adjuvant administration of an LRG1-neutralizing antibody delayed metastatic growth and increased overall survival. This study has established a systems map of early primary tumor-induced vascular changes and identified LRG1 as a therapeutic target for metastasis
Trisomy 8, A Cytogenetic Abnormality In Myelodysplastic Syndromes, Is Constitutional Or Not?
Isolated trisomy 8 is not considered presumptive evidence of myelodysplastic syndrome (MDS) in cases without minimal morphological criteria. One reason given is that trisomy 8 (+8) can be found as a constitutional mosaicism (cT8M). We tried to clarify the incidence of cT8M in myeloid neoplasms, specifically in MDS, and the diagnostic value of isolated +8 in MDS. Twenty-two MDS and 10 other myeloid neoplasms carrying +8 were studied. Trisomy 8 was determined in peripheral blood by conventional cytogenetics (CC) and on granulocytes, CD3+ lymphocytes and oral mucosa cells by fluorescence in situ hybridization (FISH). In peripheral blood CC, +8 was seen in 4/32 patients. By FISH, only one patient with chronic myelomonocytic leukemia showed +8 in all cell samples and was interpreted as a cT8M. In our series +8 was acquired in all MDS. Probably, once discarded cT8M by FISH from CD3+ lymphocytes and non-hematological cells, +8 should be considered with enough evidence to MDS
Versatile Coordination of Cyclopentadienyl-Arene Ligands and Its Role in Titanium-Catalyzed Ethylene Trimerization
Cationic titanium(IV) complexes with ansa-(η5-cyclopentadienyl,η6-arene) ligands were synthesized and characterized by X-ray crystallography. The strength of the metal-arene interaction in these systems was studied by variable-temperature NMR spectroscopy. Complexes with a C1 bridge between the cyclopentadienyl and arene moieties feature hemilabile coordination behavior of the ligand and consequently are active ethylene trimerization catalysts. Reaction of the titanium(IV) dimethyl cations with CO results in conversion to the analogous cationic titanium(II) dicarbonyl species. Metal-to-ligand backdonation in these formally low-valent complexes gives rise to a strongly bonded, partially reduced arene moiety. In contrast to the η6-arene coordination mode observed for titanium, the more electron-rich vanadium(V) cations [cyclopentadienyl-arene]V(NiPr2)(NC6H4-4-Me)+ feature η1-arene binding, as determined by a crystallographic study. The three different metal-arene coordination modes that we experimentally observed model intermediates in the cycle for titanium-catalyzed ethylene trimerization. The nature of the metal-arene interaction in these systems was studied by DFT calculations.
Oligonucleotide array-CGH identifies genomic subgroups and prognostic markers for tumor stage mycosis fungoides
Mycosis fungoide (MF) patients who develop tumors or extracutaneous involvement usually have a poor prognosis with no curative therapy available so far. In the present European Organization for Research and Treatment of Cancer (EORTC) multicenter study, the genomic profile of 41 skin biopsies from tumor stage MF (MFt) was analyzed using a high-resolution oligo-array comparative genomic hybridization platform. Seventy-six percent of cases showed genomic aberrations. The most common imbalances were gains of 7q33.3q35 followed by 17q21.1, 8q24.21, 9q34qter, and 10p14 and losses of 9p21.3 followed by 9q31.2, 17p13.1, 13q14.11, 6q21.3, 10p11.22, 16q23.2, and 16q24.3. Three specific chromosomal regions, 9p21.3, 8q24.21, and 10q26qter, were defined as prognostic markers showing a significant correlation with overall survival (OS) (P=0.042, 0.017, and 0.022, respectively). Moreover, we have established two MFt genomic subgroups distinguishing a stable group (0-5 DNA aberrations) and an unstable group (>5 DNA aberrations), showing that the genomic unstable group had a shorter OS (P=0.05). We therefore conclude that specific chromosomal abnormalities, such as gains of 8q24.21 (MYC) and losses of 9p21.3 (CDKN2A, CDKN2B, and MTAP) and 10q26qter (MGMT and EBF3) may have an important role in prognosis. In addition, we describe the MFt genomic instability profile, which, to our knowledge, has not been reported earlier
Routine use of ancillary investigations in staging diffuse large B-cell lymphoma improves the International Prognostic Index (IPI)
<p>Abstract</p> <p>Background</p> <p>The International Prognostic Index (IPI) is used to determine prognosis in diffuse large B-cell lymphoma (DLBCL). One of the determinants of IPI is the stage of disease with bone marrow involvement being classified as stage IV. For the IPI, involvement on bone marrow is traditionally defined on the basis of histology with ancillary investigations used only in difficult cases to aid histological diagnosis. This study aimed to determine the effect of the routine use of flow cytometry, immunohistochemistry and molecular studies in bone marrow staging upon the IPI.</p> <p>Results</p> <p>Bone marrow trephines of 156 histologically proven DLBCL cases at initial diagnosis were assessed on routine histology, and immunohistochemistry using two T-cell markers (CD45RO and CD3), two B-cell markers (CD20 and CD79a) and kappa and lambda light chains. Raw flow cytometry data on all samples were reanalysed and reinterpreted blindly. DNA extracted from archived paraffin-embedded trephine biopsy samples was used for immunoglobulin heavy chain and light chain gene rearrangement analysis. Using immunophenotyping (flow cytometry and immunohistochemistry), 30 (19.2%) cases were upstaged to stage IV. A further 8 (5.1%) cases were upstaged using molecular studies. A change in IPI was noted in 18 cases (11.5%) on immunophenotyping alone, and 22 (14.1%) cases on immunophenotyping and molecular testing. Comparison of two revised IPI models, 1) using immunophenotyping alone, and 2) using immunophenotyping with molecular studies, was performed with baseline IPI using a Cox regression model. It showed that the revised IPI model using immunophenotyping provides the best differentiation between the IPI categories.</p> <p>Conclusion</p> <p>Improved bone marrow staging using flow cytometry and immunohistochemistry improves the predictive value of the IPI in patients with DLBCL and should be performed routinely in all cases.</p
Covert Genetic Selections to Optimize Phenotypes
In many high complexity systems (cells, organisms, institutions, societies, economies, etc.), it is unclear which components should be regulated to affect overall performance. To identify and prioritize molecular targets which impact cellular phenotypes, we have developed a selection procedure (“SPI”–single promoting/inhibiting target identification) which monitors the abundance of ectopic cDNAs. We have used this approach to identify growth regulators. For this purpose, complex pools of S. cerevisiae cDNA transformants were established and we quantitated the evolution of the spectrum of cDNAs which was initially present. These data emphasized the importance of translation initiation and ER-Golgi traffic for growth. SPI provides functional insight into the stability of cellular phenotypes under circumstances in which established genetic approaches cannot be implemented. It provides a functional “synthetic genetic signature” for each state of the cell (i.e. genotype and environment) by surveying complex genetic libraries, and does not require specialized arrays of cDNAs/shRNAs, deletion strains, direct assessment of clonal growth or even a conditional phenotype. Moreover, it establishes a hierarchy of importance of those targets which can contribute, either positively or negatively, to modify the prevailing phenotype. Extensions of these proof-of-principle experiments to other cell types should provide a novel and powerful approach to analyze multiple aspects of the basic biology of yeast and animal cells as well as clinically-relevant issues
Experimental Assessment of the Role of Acetaldehyde in Alcoholic Cardiomyopathy
Alcoholism is one of the major causes of non-ischemic heart damage. The myopathic state of the heart due to alcohol consumption, namely alcoholic cardiomyopathy, is manifested by cardiac hypertrophy, compromised ventricular contractility and cardiac output. Several mechanisms have been postulated for alcoholic cardiomyopathy including oxidative damage, accumulation of triglycerides, altered fatty acid extraction, decreased myofilament Ca(2+ )sensitivity, and impaired protein synthesis. Despite intensive efforts to unveil the mechanism and ultimate toxin responsible for alcohol-induced cardiac toxicity, neither has been clarified thus far. Primary candidates for the specific toxins are ethanol, its first and major metabolic product - acetaldehyde (ACA) and fatty acid ethyl esters. Evidence from our lab suggests that ACA directly impairs cardiac function and promotes lipid peroxidation resulting in oxidative damage. The ACA-induced cardiac contractile depression may be reconciled with inhibitors of Cytochrome P-450 oxidase, xanthine oxidase and lipid peroxidation Unfortunately, the common methods to investigate the toxicity of ACA have been hampered by the fact that direct intake of ACA is toxic and unsuitable for chronic study, which is unable to provide direct evidence of direct cardiac toxicity for ACA. In order to overcome this obstacle associated with the chemical properties of ACA, our laboratory has used the chronic ethanol feeding model in transgenic mice with cardiac over-expression of alcohol dehydrogenase (ADH) and an in vitro ventricular myocyte culture model. The combination of both in vivo and in vitro approaches allows us to evaluate the role of ACA in ethanol-induced cardiac toxicity and certain cellular signaling pathways leading to alcoholic cardiomyopathy
Validation and functional characterization of GWAS-identified variants for chronic lymphocytic leukemia: a CRuCIAL study
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