172 research outputs found
Tryptophan-PNA gc Conjugates Self-Assemble to Form Fibers
No full textPeptide nucleic acids and their conjugates to peptidescan self-assembleand generate complex architectures. In this work, we explored theself-assembly of PNA dimers conjugated to the dipeptide WW. Our studiessuggest that the indole ring of tryptophan promotes aggregation ofthe conjugates. The onset of fluorescence is observed upon self-assembly.The structure of self-assembled WWgc is concentration-dependent, beingspherical at low concentrations and fibrous at high concentrations.As suggested by molecular modeling studies, fibers are stabilizedby stacking interactions between tryptophans and Watson-Crick hydrogenbonds between nucleobases
Nouvelle publication : Aux origines des GAFAM
No full textGRISET Pascal, « Aux origines des GAFAM », in Bouzeghoub, M. et Mosseri, R., Les Big Data à découvert, Paris, CNRS Editions, 2017, 354 pages, pp 300-301. Cet ouvrage collectif analyse l'impact des données numériques et l'ensemble de ses répercussions à travers 150 articles synthétiques rédigés par un panel d’experts. Les Big Data à découvert, sous la direction de MOKRANE BOUZEGHOUB et RÉMY MOSSERI, CNRS éditions, 2017
Chiral fibers formation upon assembly of tetraphenylalanine peptide conjugated to a PNA dimer
No full textSelf-assembly of biomolecules such as peptides, nucleic acids or their analogues affords supramolecular objects, exhibiting structures and physical properties dependent on the amino-acid or nucleobase composition. Conjugation of the peptide diphenylalanine (FF) to peptide nucleic acids triggers formation of self-assembled structures, mainly stabilized by interactions between FF. In this work we report formation of homogeneous chiral fibers upon self-assembly of the hybrid composed of the tetraphenylalanine peptide (4F) conjugated to the PNA dimer adenine-thymine (at). In this case nucleobases seem to play a key role in determining the morphology and chirality of the fibers. When the PNA "at" is replaced by guanine-cytosine dimer "gc", disordered structures are observed. Spectroscopic characterization of the self-assembled hybrids, along with AFM and SEM studies is reported. Finally, a structural model consistent with the experimental evidences has also been obtained, showing how the building blocks of 4Fat arrange to give helical fibers
Paediatric and adolescent alveolar soft part sarcoma: A joint series from European cooperative groups
No full textAlveolar soft part sarcomas (ASPS) are generally chemo- and radio-resistant mesenchymal tumours, with no standardized treatment guidelines. We describe the clinical behaviour of paediatric ASPS and compare these features to previously reported adult series.
PATIENTS AND METHODS:
The clinical data of 51 children and adolescents with ASPS, prospectively enrolled in or treated according to seven European Paediatric trials were analysed.
RESULTS:
Median age was 13 years [range: 2-21]. Primary sites included mostly limbs (63%). IRS post-surgical staging was: IRS-I (complete resection) 35%, II (microscopic residual disease) 20%, III (gross residual disease) 18% and IV (metastases) 27%. Only 3 of the 18 evaluable patients (17%) obtained a response to conventional chemotherapy. After a median follow-up of 126 months (range: 9-240), 14/18 patients with IRS-I tumour, 10/10 IRS-II, 7/9 IRS-III and 2/14 IRS-IV were alive in remission. Sunitinib treatment achieved two very good partial responses in four patients. Ten-year overall survival (OS) and event free survival (EFS) was 78.0 ± 7% and 62.8 ± 7% respectively. Stage IV, size >5 cm and T2 tumours had a poorer outcome, but only IRS staging was an independent prognostic factor.
CONCLUSIONS:
ASPS is a very rare tumour frequently arising in adolescents and in the extremities, and chemo resistant. Local surgical control is critical. ASPS is a poorly chemo sensitive tumour. For IRS-III/IV tumours, delayed radical local therapies including surgery are essential. Metastatic patients had a poor prognosis but targeted therapies showed promising results
Paediatric and adolescent alveolar soft part sarcoma: A joint series from European cooperative groups
No full textAbstract
BackgroundAlveolar soft part sarcomas (ASPS) are generally chemo- and radio-resistant mesenchymal tumours, with no standardized treatment guidelines. We describe the clinical behaviour of paediatric ASPS and compare these features to previously reported adult series.
Patients and MethodsThe clinical data of 51 children and adolescents with ASPS, prospectively enrolled in or treated according to seven European Paediatric trials were analysed.
ResultsMedian age was 13 years [range: 2-21]. Primary sites included mostly limbs (63%). IRS post-surgical staging was: IRS-I (complete resection) 35%, II (microscopic residual disease) 20%, III (gross residual disease) 18% and IV (metastases) 27%. Only 3 of the 18 evaluable patients (17%) obtained a response to conventional chemotherapy. After a median follow-up of 126 months (range: 9-240), 14/18 patients with IRS-I tumour, 10/10 IRS-II, 7/9 IRS-III and 2/14 IRS-IV were alive in remission. Sunitinib treatment achieved two very good partial responses in four patients. Ten-year overall survival (OS) and event free survival (EFS) was 78.07% and 62.8 +/- 7% respectively. Stage IV, size >5cm and T2 tumours had a poorer outcome, but only IRS staging was an independent prognostic factor.
ConclusionsASPS is a very rare tumour frequently arising in adolescents and in the extremities, and chemo resistant. Local surgical control is critical. ASPS is a poorly chemo sensitive tumour. For IRS-III/IV tumours, delayed radical local therapies including surgery are essential. Metastatic patients had a poor prognosis but targeted therapies showed promising results. Pediatr Blood Cancer 2013;60:1826-1832. (c) 2013 Wiley Periodicals, Inc
Visible point vector summations from hypercube and hyperpyramid lattices
No full textNew identities are given, based on ideas related to visible (from the origin) point vectors. Each result was found from summing on vpv lattices dividing space
into radial regions from the origin. This is
related to recent work by the author in which new partition type infinite products were derived. Also
recently, Baake et al [3] and Mosseri [14] considered the 2-D
visible lattice points as part of an optical
experiment in which the so-called Optical Fourier Transform was applied. Many of the techniques
espoused in Glasser and Zucker [11], and in Ninham et al [15] involving Mellin and Möbius inversions
are applicable also to the current paper
FX MiniRAIL catheter usage for treatment of de novo complex coronary lesions: results from the "OFFAR"
No full textGradual prolonged balloon angioplasty may cause less arterial trauma, higher success rates, and fewer complications than conventional angioplasty (POBA). The OFFAR aimed to determine the safety and effectiveness of the FX MiniRAIL (FX) catheter, used with a slow, stepwise inflation protocol
Visualisation of the left anterior descending coronary artery on CT images used for breast radiotherapy planning.
No full textOBJECTIVE: To assess the visualisation of the left anterior descending (LAD) coronary artery on CT images used for breast radiation treatment planning.
METHODS: Delineation of the LAD artery was achieved for 25 breast patients by 1 radiologist and 1 radiation oncologist independently on two sets of images for each patient: one pre-operative CT scan using intravenous (IV) contrast media to determine the primary gross tumour volume (GTV) and one post-operative CT scan used for treatment planning. A Student's paired t-test was used to compare the number of CT slices in which the LAD was visible for each patient in the two series. Interpolations and extrapolations of the LAD volume were performed for the left-sided cases using a published heart atlas in order to report doses to the LAD structure.
RESULTS: There was a non-significant difference between the results with and without IV contrast media (p=0.34 for the radiologist; p=0.90 for the radiation oncologist). The visible LAD artery corresponded to a 30% portion (range 12-47%) of the interpolated structure. The maximum dose to the left artery varied widely, from 2.7 to 41.7 Gy, in the group of patients with left breast tumours. The largest values (>25 Gy) corresponded to those patients in whom the LAD artery distal extremity lay inside the breast fields.
CONCLUSIONS: With the current planning CT protocol, only one-third of the LAD artery could be objectively visualised. Contrast-enhanced imaging used for GTV delineation before the breast surgery did not improve the visualisation of the artery.
ADVANCES IN KNOWLEDGE: This study has revealed the lack of consistency that may be encountered when contouring heart vessels, thereby questioning the reliability of dose reporting
Prophylactic Pre-Operative Coronary Revascularization Is the Phoenix Awakening?⁎⁎Editorials published in the Journal of the American College of Cardiologyreflect the views of the author and do not necessarily represent the view of JACCor the American College of Cardiology.
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