338 research outputs found
Mismatch repair gene defects in sporadic colorectal cancer enhance immune surveillance
Background: There is evidence that colorectal cancers (CRC) with DNA mismatch repair deficiency (MMR-D) are associated with a better prognosis than the generality of large bowel malignancies. Since an active immune surveillance process has been demonstrated to influence CRC outcome, we investigated whether MMR-D can enhance the immune response in CRC.
Patients and Methods: A group of 113 consecutive patients operated for CRC (42 stage I or II and 71 with stage III or IV) was retrospectively analyzed. The expression of MMR genes (MSH2, MLH1, MSH6 and PSM2) and co-stimulatory molecule CD80 was assessed by tissue microarray immunohistochemistry. In addition, tumor infiltrating mononuclear cells (TIMC) and T cell subpopulations (CD4, CD8, T-bet and FoxP-3) were quantified. The effect of specific siRNA (siMSH2, siMLH1, siMSH6 and siPSM2) transfection in HT29 on CD80 expression was quantified by flow cytometry. Non parametric statistics and survival analysis were used.
Results: Patients with MMR-D showed a higher T-bet/CD4 ratio (p = 0.02), a higher rate of CD80 expression and CD8 lymphocyte infiltration compared to those with no MMR-D. Moreover, in the MMR-D group, the Treg marker FoxP-3 was not expressed (p = 0.05). MMR-D patients with stage I or II and T-bet expression had a significant better survival (p = 0.009). Silencing of MSH2, MLH1 and MSH6, but not PSM2, significantly increased the rate of CD80+ HT29 cells (p = 0.007, p = 0.023 and p = 0.015, respectively).
Conclusions: CRC with MMR-D showed a higher CD80 expression, and CD8+ and Th1 T-cell infiltration. In vitro silencing of MSH2, MLH1 and MSH6 significantly increased CD80+ cell rate. These results suggest an enhanced immune surveillance mechanism in presence of MMR-D
The mineral tooeleite Fe6(AsO3)4SO4(OH)4⋅4H2O – An infrared and Raman spectroscopic study-environmental implications for arsenic remediation
Facile synthesis and reactivity study of mixed phosphane-isocyanide Pd(II) and Pd(0) complexes
The reaction between an equimolecular mixture of isocyanide CNR (CNR = di-methylphenyl isocyanide (DIC), tert-butyl isocyanide (TIC), triphenyl phosphane (PPh3) and a dechlorinated solution of the palladium allyl dimers [Pd(g3-allyl)Cl]2 (allyl = 2-Meallyl, 1,1-Me2allyl) in stoichiometric ratio yields the
mixed derivative [Pd(g3-allyl)(CNR)(PPh3)] only. Apparently, the mixed derivative represents the most stable species among all the possible ones that might be formed under those experimental conditions. Theoretical calculations are in agreement with the experimental observation and the energy stabilization
of the mixed species with respect to the homoleptic derivatives is traced back to an overall push–pull effect exerted by the isocyanide and the phosphane acting synergically. Similar behavior is observed in the case of the synthesis of the palladacyclopentadienyl complexes [Pd(C4(COOMe)4)(CNR)(PPh3)] and of the palladium(0) olefin complexes whose synthesis invariably yields the mixed [Pd(g2-ole-fin)(CNR)(PPh3)] derivatives. The paper includes studies on the reactivity toward allylamination in the case of the palladium(II) allyl complexes. A diffractometric investigation on the solid state structures
of four different palladium isocyanide–phosphane complexes is also included
C–N coupling in the gas-phase reactions of ammonia and [M(CH)]+ (M = Ni, Pd, Pt): a combined experimental/computational exercise
CD80 down-regulation is associated to aberrant DNA methylation in non-inflammatory colon carcinogenesis
A mass spectrometric study of the adducts of acetylacetone and cyanogen (Traube's isomers)
ChemInform Abstract: SYNTHESIS OF PYRIMIDINES FROM β-DICARBONYL COMPOUNDS AND CYANOGEN: A METAL-CATALYZED ONE-POT PROCESS
ChemInform Abstract: DARST. UND CHARAKTERISIERUNG VON N,N′-BIS-(O-ARSONOPHENYL)-PROPYLENDIIMIN-(1,3) UND SEINER SALZE UND KOMPLEXE
Kinetics and mechanism of the reaction of bis-\u3bc-diethylphosphidobis(tetracarbonylmanganese) with tri-n-butylphosphine
ChemInform Abstract: Metal-catalysed Highly Selective Synthesis of α-Amido-β-cyanoenaminones from Acetoacetamides and Cyanogen: Physicochemical Properties and Solid-state Conversion into Pyrroline Isomers.
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