New acenaphthylene-based dithienylethenes have been prepared. Surprisingly they did not show photochromism. However, they readily underwent a tandem addition of a nucleophile and an electrophile, leading to a small library of dearomatized colourless analogues, which, on the contrary, were endowed with photochromic activity.
View Article and Find Full Text PDFBackground: In patients with Lynch syndrome, germline mutations in DNA mismatch repair (MMR) genes cause a high risk of developing a broad spectrum of cancers. To date, the management of patients with Lynch syndrome has represented a major challenge because of large variations in age at cancer onset. Several factors, including genetic anticipation, have been proposed to explain this phenotypic heterogeneity, but the molecular mechanisms remain unknown.
View Article and Find Full Text PDFThe Peutz-Jeghers Syndrome (PJS) is an autosomal dominant polyposis disorder with increased risk of multiple cancers. STK11/LKB1 (hereafter named STK11) germline mutations account for the large majority of PJS cases whereas large deletions account for about 30% of the cases. We report here the first thorough molecular characterization of 15 large deletions identified in a cohort of 51 clinically well-characterized PJS patients.
View Article and Find Full Text PDFA small library of natural product-like compounds has been assembled by coupling an Ugi multicomponent reaction with two postcondensation transformations, carried out in one-pot fashion: a S(N)2' cyclization followed by an intramolecular Heck reaction.
View Article and Find Full Text PDFThe synthesis of phosphatidyl serine containing saturated fatty acids was thoroughly studied and optimized in order to establish a protocol amenable to large-scale synthesis. The key step was a one-pot multicomponent reaction involving an O-benzyl phosphorodiamidite, protected serine and diacylglycerol, followed by in situ oxidation of the resulting phosphite. In order to replace expensive and poorly stable tetrazole, a screening of substitutes was carried out and imidazolium chloride was selected as the best suited one.
View Article and Find Full Text PDFFamilial adenomatous polyposis is a rare autosomal dominant inherited disease (incidence, 1/8000). More than 90% of families affected by familial adenomatous polyposis have a mutation in the tumor suppressor gene adenomatous polyposis coli (APC). Mutations in this gene are characterized by 100% penetrance, although there is a variation in phenotypic expression of the disease.
View Article and Find Full Text PDFA very short convergent synthesis of dihydrobenzoxazepinones, bearing four diverse diversity points, based on coupling the Ugi reaction with a Mitsunobu cyclization, was developed. These compounds are potential α-helix mimics, where three of the four appendages are expected to imitate the residues in i, i + 4 and i + 7 positions. A library of 22 compounds bearing lipophilic substituents, designed to interact with the hydrophobic cleft of anti-apoptotic protein Bcl-xL, was synthesized.
View Article and Find Full Text PDFResearch progress is often promoted by unexpected results that open the way to new scenarios. In this communication, an unprecedented condensation of arylacetic acids and isocyanides and the unusual base-mediated rearrangement of the resulting products to give two novel classes of polysubstituted pyrrolones and pyrrolidinediones are reported.
View Article and Find Full Text PDFThe purpose of this study was to estimate vascular endothelial growth factor (VEGF) and transforming growth factor (TGF)-beta1 serum levels in children with hereditary hemorrhagic telangiectasia (HHT) type 1 and type 2 and to correlate them to the presence of arteriovenous malformations (AVMs). High VEGF levels were initially found in an infant who had been hospitalized with intestinal bleeding and suspected HHT. This case led to the evaluation of VEGF and TGF-beta1 by standard enzyme-linked immunosorbent assay in 13 children with HHT and familiarity.
View Article and Find Full Text PDFObjective: To evaluate the variation of some biomarkers related to the level of enzymatic activity dependent on the different polymorphisms.
Methods: We studied 27 butadiene-exposed workers and 37 controls using different biomarkers of the genotoxic effect. The genotypes were determined using polymerase chain reaction and restriction fragment length polymorphism-polymerase chain reaction techniques; the subjects were assigned to a specific group based on the microsomal epoxide hydrolase (mEH) activity predicted by their genotype (low, intermediate, high).
Objective: We surveyed the datasheets of 29 laboratories concerning prenatal diagnosis of de novo apparently balanced chromosome rearrangements to assess the involvement of specific chromosomes, the breakpoints distribution and the impact on the pregnancy outcome.
Method: By means of a questionnaire, data on 269.371 analyses performed from 1983 to 2006 on amniotic fluid, chorionic villus and fetal blood samples were collected.
Colorectal Dis
March 2010
Objective: To investigate whether preoperative noncolonic cancer stem cells in bone marrow (BM) of R0 colorectal cancer (CRC) patients are cancer cells and impact on liver metastases (LM) rates.
Method: Prospective data on continuous CRC patients were collected from five centres. Bone marrow aspirates, taken at laparotomy, were sent to a single lab.
beta-amino acids have been employed in the past as bifunctional building blocks in intramolecular Ugi multicomponent reactions to yield beta-lactam derivatives. By using 7-azabicyclo[2.2.
View Article and Find Full Text PDFA short (2 steps) synthesis of diverse benzoxazinones by coupling the Ugi multicomponent reaction with an intramolecular Mitsunobu substitution is reported. The cyclization step proceeds via an unexpected cine substitution.
View Article and Find Full Text PDFBackground: The Italian external quality assessment scheme in classical cytogenetics was started in 2001 as an activity funded by the National Health System and coordinated by the Italian Public Institute of Health.
Objectives: The aim of our work is to present data from the first 4 years of activity, 2001-2004.
Methods: Italian cytogenetics public laboratories were enrolled on a voluntary basis, and this nationwide program covered prenatal, postnatal and oncological diagnosis.
Lactenediynes are compounds characterized by the fusion of a beta-lactam with a cyclodeca-3-ene-1,5-diyne. In this work the most promising members of this family have been activated by attaching a carbalkoxy or a carbamoyl group to the azetidinone nitrogen, and conjugated to various DNA-complexing moieties, either acting by intercalation or through groove binding. These conjugated artificial enediynes have been demonstrated to possess in vitro ability to produce single and double strand cleavage of plasmid DNA.
View Article and Find Full Text PDFHereditary Haemorrhagic Telangiectasia (HHT) or Rendu-Osler-Weber syndrome is an autosomal dominant disease characterized by local angiodysplasia affecting different organism districts. From a clinical viewpoint, HHT patients suffer from epistaxis, mucocutaneous telangiectases and arteriovenous malformations in various organs. Mutations in two known genes (ENG and ALK1) account for the majority of HHT patients.
View Article and Find Full Text PDFA 4-component Ugi reaction with a suitable isocyanide, followed by a novel secondary transformation involving a Pd(II)-mediated (R5 = H) or a Pd(0)-mediated (R5 = CO2Me) SN2' cyclization to give highly functionalized N-acyl-2-vinylpyrrolidines, is reported. The overall yields are usually good and in most cases the Pd(0)-catalyzed reaction gave the final product in almost quantitative yield.
View Article and Find Full Text PDFThis paper introduces a new substrate for reverse-phase protein microarray applications based on macroporous silicon. A key feature of the microarray substrate is the vastly surface enlarging properties of the porous silicon, which simultaneously offers highly confined microarray spots. The proof of principle of the reverse array concept was demonstrated in the detection of different levels of cyclin E, a possible cancer biomarker candidate which regulates G1-S transition and correlates with poor prognosis in different types of human cancers.
View Article and Find Full Text PDFMulticomponent reactions are a powerful tool in combinatorial chemistry and diversity-oriented synthesis for the assembly of collections of complex molecules in a highly straightforward and efficient manner. Additional advantages in terms of isolation and purification can be obtained by performing these condensations on a polymeric support or with the aid of solid-supported reagents, scavengers or catalysts. This review covers research published in this area during the last two years and provides a perspective of future directions.
View Article and Find Full Text PDFSTRADalpha is a pseudokinase that forms a heterotrimeric complex with the scaffolding protein MO25 and the tumor suppressor serine threonine protein kinase LKB1. Mutations in the LKB1 gene are responsible for the Peutz-Jeghers Syndrome (PJS) characterized by a predisposition to hamartomatous polyps and hyperpigmentation of the buccal mucosa. Mutations in LKB1 have also been observed in some sporadic tumours unrelated to PJS.
View Article and Find Full Text PDFIn a previously published article (Resta et al., 2006) on Robert's syndrome in prenatal diagnosis, a case of a 36-year-old woman and her 36-year-old, nonconsanguineous husband were presented. Our findings suggest the existence of nonsense mediated decay (NMD) variability which could account for the varying severity reported in carriers of identical mutations.
View Article and Find Full Text PDFGermline mutations of the tumor suppressor gene LKB1/STK11 are responsible for the Peutz-Jeghers syndrome (PJS), an autosomal-dominant disorder characterized by mucocutaneous pigmentation, hamartomatous polyps, and an increased risk of associated malignancies. In this study, we assessed the presence of pathogenic mutations in the LKB1/STK11 gene in 46 unrelated PJS families, and also carried genotype-phenotype correlation in regard of the development of cancer in 170 PJS patients belonging to these families. All LKB1/STK11 variants detected with single-strand conformational polymorphism were confirmed by direct sequencing, and those without LKB1/STK11 mutation were further submitted to Southern blot analysis for detection of deletions/rearrangements.
View Article and Find Full Text PDFA short, two-step approach to the synthesis of diazepane or diazocane systems, based on a Ugi multicomponent reaction followed by a subsequent intramolecular SN2 reaction was studied. 1-sulfonyl tetrahydrobenzo[e]-1,4-diazepin-1-ones 1 were obtained in very high yield through a Ugi multicomponent reaction followed by Mitsunobu cyclization. On the other hand, aliphatic 1-sulfonyl 1,4-diazepan-5-ones 2 could be obtained employing different cyclization conditions (sulfuryl diimidazole).
View Article and Find Full Text PDFHereditary non-polyposis colorectal cancer (HNPCC) is caused by inactivating mutations of DNA mismatch repair genes. Large genomic rearrangements in these genes have been increasingly recognized as important causes of HNPCC. Using multiplex ligation-dependent probe amplification, we identified three MSH2 deletions in Italian patients with HNPCC (proband A: exons 1-3, proband M: exon 8, and proband C: exons 1-6).
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