Treatment of cervical cancer Touboul, Cyril; Skalli, Dounia; Guillo, Eric ...
La revue du praticien
64, Številka:
6
Magazine Article
The treatment of uterine cervical cancer evolved the last past twenty years. The management of early stages cervical cancer is based on surgery +/- after an initial brachytherapy in order to increase ...loco-regional control. A conservative treatment preserving uterine and ovarian functions is sometimes possible for young patients < 40 years old wishing to conceive. This strategy allows pregnancies with low recurrence rate. Finally, the use of the sentinel lymph node staging should be validated within the next few years. The treatment of locally advanced stages is based on concomitant chemoradiation therapy, which allows obtaining an important complete tumour response rate (90%). Thereafter, the irradiation modalities will depend on the para-aortic lymph nodes status diagnosed by PET-computed tomography +/- staging laparoscopic para-aortic lymphadenectomy. The use of completion surgery may be indicated in case of cervical residual disease and has to be balanced with its specific morbidity. All the decisions are made during a multidisciplinary tumour board.
•We analyze Titan's tholins using HPLC-Orbitrap.•We strictly identify the isomers of seven of the major molecules constituting tholins.•All confirmed molecules bear nitrogen and most of them are ...aromatics.•This supports the hypothesis of a tholins formation passing through PANH.
Although the Cassini Spacecraft and the Huygens lander provided vast information about Titan atmospheric chemistry and the formation of its aerosols, the exact composition of these aerosols still remains unknown. A fruitful proxy to investigate these aerosols is the use of laboratory experiments that allow producing and studying analogs of Titan aerosol, the so-called tholins. Even when produced in the laboratory, unveiling the exact composition of the aerosol remains problematic due to the high complexity of the material. Numerous advances have been recently made using high-resolution mass spectrometry (HRMS) (Pernot et al. 2010 Anal. Chem. 82, 1371; Somogyi et al. 2012 Int. J. Mass Spectrom. 316–318, 157–163; Gautier et al. 2014 Earth Planet. Sci. Lett. 404, 33–42) that allowed the separation of isobaric compounds and a robust identification of chemical species composing tholins regarding their molecular formulae. Nevertheless isomeric species cannot be resolved by a simple mass measurement. We propose here an analysis of tholins by high performance liquid chromatography (HPLC) coupled to HRMS to unveil this isomeric ambiguity for some of the major tholins compounds. By comparing chromatograms obtained when analyzing tholins and chemical standards, we strictly identified seven molecules in our tholins samples: melamine, cyanoguanidine, 6-methyl-1,3,5-triazine-2,4-diamine, 2,4,6-triaminopyrimidine, 3-amino-1,2,4-triazole, 3,5-Dimethyl-1,2,4-triazole and 2,4-diamino-1,3,5-triazine. Several molecules, including hexamethylenetriamine (HMT) were not present at detectable levels in our sample. The use for the first time of a coupled HPLC–HRMS technique applied to tholins study demonstrated the interest of such a technique compared to single high-resolution mass spectrometry for the study of tholins composition.
Influx of solar photons and heavy charged particles from Saturn's magnetosphere on Titan's atmosphere – mainly comprised of methane and nitrogen – induce an intense organic photochemistry which leads ...to the formation of a large amount of aerosols in suspension in the atmosphere. In order to infer the role of nitrogen in aerosol formation processes we produced laboratory analogs of Titan's aerosols. In this work, we compare the composition of different analogs by using high resolution mass spectrometry and propose an additional study using gas-chromatography coupled to mass-spectrometry for a new kind of analog produced by polymerization of cryogenically trapped gaseous neutral species. The comparison of these materials emphasizes the importance of ion chemistry processes for the inclusion of nitrogen in molecules constituting Titan's tholins. A statistical approach is also used for the treatment of high resolution mass spectra of these highly complex organic materials. This method allows distinguishing molecular families that can be reconstructed by an ideal copolymer. We investigate several copolymer reconstructions, and we suggest that an HCN (or CH3CN)/C2H4 based copolymer agrees well with the polymeric structure of tholins produced with 5% of methane in nitrogen.
•We analyze different Titan's tholins with orbitrap mass spectrometry.•Results show the importance of ionic chemistry for nitrogen incorporation in tholins.•A statistical approach is used to deal with the high complexity of the mass spectra.•Tholins structures present different molecular families.•Copolymer reconstruction suggests HCN/C2H4 as a possible pattern for polymerization.
Although the Cassini Spacecraft and the Huygens lander provided numerous information about Titan atmospheric chemistry and the formation of its aerosols, the exact composition of these aerosols still ...remains unknown. A fruitful proxy to investigate these aerosols is the use of laboratory experiments that allow producing and studying analogs of Titan aerosol, the so35 called tholins. Even when produced in the laboratory, unveiling the exact composition of the aerosol remains problematic due to the high complexity of the material. Numerous advances have been recently made using high-resolution mass spectrometry (HRMS) (Pernot et al. 2010, Somogyi et al. 2012, Gautier et al. 2014) that allowed the separation of isobaric compounds and a robust identification of chemical species composing tholins regarding their molecular formulae. Nevertheless isomeric species cannot be resolved by a simple mass measurement. We propose here an analysis of tholins by high performance liquid chromatography (HPLC) coupled to HRMS to unveil this isomeric ambiguity for some of the major tholins compounds. By comparing chromatograms obtained when analyzing tholins and chemical standards, we strictly identified seven molecules in our tholins samples: melamine, cyanoguanidine, 6-methyl-1,3,5-triazine-2,4-diamine, 2,4,6-triaminopyrimidine, 3-amino- 1,2,4-triazole, 3,5-Dimethyl-1,2,4-triazole and 2,4-diamino-1,3,5-triazine. Several molecules, including hexamethylenetriamine (HMT) were not present at detectable levels in our sample. The use for the first time of a coupled HPLC-HRMS technique applied to tholins study demonstrated the interest of such a technique compared to single high-resolution mass spectrometry for the study of tholins composition.
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