129 research outputs found
Incoherent deeply virtual Compton scattering off He 4
No full textVery recently, for the first time, the two channels of nuclear deeply virtual Compton scattering, the coherent and incoherent ones, have been separated by the CLAS collaboration at the Jefferson Laboratory, using a He4 target. The incoherent channel, which can provide a tomographic view of the bound proton and shed light on its elusive parton structure, is thoroughly analyzed here in the impulse approximation. A convolution formula for the relevant nuclear cross sections in terms of those for the bound proton is derived. Novel scattering amplitudes for a bound moving nucleon have been obtained and used. A state-of-the-art nuclear spectral function, based on the Argonne-18 potential, exact in the two-body part, with the recoiling system in its ground state, and modelled in the remaining contribution, with the recoiling system in an excited state, has been used. Different parametrizations of the generalized parton distributions of the struck proton have been tested. A good overall agreement with the data for the beam spin asymmetry is obtained. It is found that the conventional nuclear effects predicted by the present approach are relevant in deeply virtual Compton scattering and in the competing Bethe-Heitler mechanism, but they cancel each other to a large extent in their ratio, to which the measured asymmetry is proportional. Besides, the calculated ratio of the beam spin asymmetry of the bound proton to that of the free one does not describe that estimated by the experimental collaboration. This points to possible interesting effects beyond the impulse approximation analysis presented here. It is therefore clearly demonstrated that the comparison of the results of a conventional realistic approach, as the one presented here, with future precise data, has the potential to expose quark and gluon effects in nuclei. Interesting perspectives for the next measurements at high luminosity facilities, such as JLab at 12 GeV and the future Electron Ion Collider, are addressed
Adjuvant postoperative radiotherapy in rectal cancer: 148 cases treated at Florence University with 8 years median follow up
No full text
Are postoperative fever and/or septic complications prognostic factors in colorectal cancer resected for cure?
No full textLocal recurrence in rectal cancer: an italian perspective from three units of Coloproctology.
No full textHeteronuclear NMR investigations of dynamic regions of intact Escherichia coli ribosomes.
No full text15N-(1)H NMR spectroscopy has been used to probe the dynamic properties of uniformly (15)N labeled Escherichia coli ribosomes. Despite the high molecular weight of the complex ( approximately 2.3 MDa), [(1)H-(15)N] heteronuclear single-quantum correlation spectra contain approximately 100 well resolved resonances, the majority of which arise from two of the four C-terminal domains of the stalk proteins, L7/L12. Heteronuclear pulse-field gradient NMR experiments show that the resonances arise from species with a translational diffusion constant consistent with that of the intact ribosome. Longitudinal relaxation time (T(1)) and T(1 rho) (15)N-spin relaxation measurements show that the observable domains tumble anisotropically, with an apparent rotational correlation time significantly longer than that expected for a free L7/L12 domain but much shorter than expected for a protein rigidly incorporated within the ribosomal particle. The relaxation data allow the ribosomally bound C-terminal domains to be oriented relative to the rotational diffusion tensor. Binding of elongation factor G to the ribosome results in the disappearance of the resonances of the L7/L12 domains, indicating a dramatic reduction in their mobility. This result is in agreement with cryoelectron microscopy studies showing that the ribosomal stalk assumes a single rigid orientation upon elongation factor G binding. As well as providing information about the dynamical properties of L7/L12, these results demonstrate the utility of heteronuclear NMR in the study of mobile regions of large biological complexes and form the basis for further NMR studies of functional ribosomal complexes in the context of protein synthesis
Outcome and prognostic factors of local recurrent rectal cancer: a pooled analysis of 150 patients.
No full textSurgery is the only curative treatment in patients with locally
recurrent rectal cancer (LRRC). The aim of this study was to evaluate the outcome
and the prognostic factors of tumour-free resection margin (R0) and overall
survival (OS) in LRRC.
METHODS: Consecutive LRRC patients observed between 1987 and 2005 in three
Italian university hospitals were evaluated. Survival curves were estimated using
the Kaplan-Meier method and compared with the log-rank test. In order to identify
factors associated with both R0 resection and OS, a logistic regression analysis
was performed in patients who underwent surgery with curative intent.
RESULTS: Out of 150 patients with LRRC, 107 underwent surgery, but since 7 were
found to have unresectable disease only 100 underwent surgical resection. Of
them, 51 underwent radical and 49 extended resection. Sixty of the 107 patients
underwent multimodality treatment. In 61 patients, R0 resection was achieved.
Median OS after surgery was 43.4 months. In patients, who had surgery with
curative intent, independent variables associated with R0 resection were: surgery
for the primary tumour performed in other hospitals (p = 0.042) extended
resection (p = 0.025) and use of positron emission tomography (PET) as a staging
modality (p = 0.03). Independent variables associated with OS were:
post-operative radiotherapy (p = 0.004), stage of the primary tumour (p = 0.004),
R0 resection (p = 0.00001), and use of PET (0.02).
CONCLUSIONS: Resection for LRRC results in improved survival. Other than the
well-known prognostic factors R0 resection and OS, PET scan has an independent
impact both on OS and R0 resection. It should therefore be included in routine
clinical practice when staging LRRC
Outcome and prognostic factors of local recurrent rectal cancer: a pooled analysis of 150 patients.
No full textBackground: Surgery is the only curative treatment in patients with locally recurrent rectal cancer (LRRC). The aim of this study was to evaluate the outcome and the prognostic factors of tumour-free resection margin (R0) and overall survival (OS) in LRRC.
Methods: Consecutive LRRC patients observed between 1987 and 2005 in three Italian university hospitals were evaluated. Survival curves were estimated using the Kaplan–Meier method and compared with the log-rank test. In order to identify factors associated with both R0 resection and OS, a logistic regression analysis was performed in patients who underwent surgery with curative intent.
Results: Out of 150 patients with LRRC, 107 underwent surgery, but since 7 were found to have unresectable disease only 100 underwent surgical resection. Of them, 51 underwent radical and 49 extended resection. Sixty of the 107 patients underwent multimodality treatment. In 61 patients, R0 resection was achieved. Median OS after surgery was 43.4 months. In patients, who had surgery with curative intent, independent variables associated with R0 resection were: surgery for the primary tumour performed in other hospitals (p = 0.042) extended resection (p = 0.025) and use of positron emission tomography (PET) as a staging modality (p = 0.03). Independent variables associated with OS were: post-operative radiotherapy (p = 0.004), stage of the primary tumour (p = 0.004), R0 resection (p = 0.00001), and use of PET (0.02).
Conclusions: Resection for LRRC results in improved survival. Other than the well-known prognostic factors R0 resection and OS, PET scan has an independent impact both on OS and R0 resection. It should therefore be included in routine clinical practice when staging LRRC
Structure, dynamics and folding of an Immunoglobulin Domain of the Gelation Factor (ABP-120) from Dictyostelium discoideum
No full textWe have carried out a detailed structural and dynamical characterisation of the isolated fifth repeat of the gelation factor (ABP-120) from Dictyostelium discoideum (ddFLN5) by NMR spectroscopy to provide a basis for studies of co-translational folding on the ribosome of this immunoglobulin-like domain. The isolated ddFLN5 can fold autonomously in solution into a structure that resembles very closely the crystal structure of the domain in a construct in which the adjacent sixth repeat (ddFLN6) is covalently linked to its C-terminus in tandem but deviates locally from a second crystal structure in which ddFLN5 is flanked by ddFLN4 and ddFLN6 at both N- and C-termini. Conformational fluctuations were observed via 15N relaxation methods and are primarily localised in the interstrand loops that encompass the C-terminal hemisphere. These fluctuations are distinct in location from the region where line broadening is observed in ddFLN5 when attached to the ribosome as part of a nascent chain. This observation supports the conclusion that the broadening is associated with interactions with the ribosome surface [Hsu, S. T. D., Fucini, P., Cabrita, L. D., Launay, H., Dobson, C. M. & Christodoulou, J. (2007). Structure and dynamics of a ribosome-bound nascent chain by NMR spectroscopy. Proc. Natl. Acad. Sci. USA, 104, 16516–16521]. The unfolding of ddFLN5 induced by high concentrations of urea shows a low population of a folding intermediate, as inferred from an intensity-based analysis, a finding that differs from that of ddFLN5 as a ribosome-bound nascent chain. These results suggest that interesting differences in detail may exist between the structure of the domain in isolation and when linked to the ribosome and between protein folding in vitro and the folding of a nascent chain as it emerges from the ribosome
Craniofacial catch-up growth in intrauterine growth retarded rats following postnatal nutritional rehabilitation
No full textFil: Luna, María Eugenia. Fil: Quintero, Fabián Aníbal. Instituto de Genética Veterinaria. Facultad de Ciencias Veterinarias. Universidad Nacional de La Plata; ArgentinaFil: Cesani Rossi, María Florencia. Instituto de Genética Veterinaria. Facultad de Ciencias Veterinarias. Universidad Nacional de La Plata; ArgentinaFil: Fucini, María Cecilia. Instituto de Genética Veterinaria. Facultad de Ciencias Veterinarias. Universidad Nacional de La Plata; ArgentinaFil: Prío, Verónica. Servicio de Diagnóstico por Imagen. Facultad de Ciencias Veterinarias. Universidad Nacional de La Plata; ArgentinaFil: Guimarey, Luis Manuel. Instituto de Genética Veterinaria. Facultad de Ciencias Veterinarias. Universidad Nacional de La Plata; ArgentinaFil: Oyhenart, Evelia Edith. Cátedra de Antropología Biológica IV. Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; Argentin
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