994 resultados para line: formation
Resumo:
Aquest estudi analitza les pràctiques diàries, els valors socials i les actituds de la població catalana en el procés de transició cap a la societat xarxa. Analitza el comportament de les persones a Internet i fora d'Internet, investigant el paper específic dels usos d'Internet a l'hora d'influenciar pràctiques i actituds. Es basa en les respostes a una enquesta de 3.005 individus, una mostra representativa de la població catalana el 2002. L'enquesta es va fer entre el febrer i el maig del 2002, i es basava en entrevistes cara a cara a partir d'un qüestionari de 179 preguntes. Es van utilitzar fonts secundàries per a situar els resultats catalans, particularment sobre els usos d'Internet, en el context global. L'anàlisi es va completar el 2007 incorporant-hi noves dades secundàries. L'estudi va cobrir pràctiques socials de treball, comunicació, sociabilitat, usos d'espai i temps, usos d'Internet, identitat cultural, pràctica política, associacionisme i formació de projectes d'autonomia. Es van construir diversos models estadístics per a proporcionar una anàlisi causal de cada una d'aquestes àrees d'estudi. El descobriment més significatiu fa referència a la relació entre els usos d'Internet i la construcció d'autonomia per part d'actors socials. Fent servir anàlisis factorial, l'estudi va definir cinc índexs d'autonomia que eren estadísticament independents: autonomia personal, autonomia professional, autonomia comunicativa, autonomia corporal i autonomia sociopolítica. Cada un d'aquests índexs d'autonomia independents estan fortament associats amb la freqüència i la intensitat de l'ús d'Internet, i les relacions observades es mantenen quan es controlen per variables sociodemogràfiques. A partir d'aquest estudi es pot afirmar que Internet és una plataforma important per a la construcció d'autonomia en la societat xarxa. En general, la societat catalana sembla que canviï de manera similar a altres societats en transició, amb l'èmfasi afegit del paper del territori i la família a l'hora d'enfortir les relacions socials, amb la contribució positiva d'Internet a un dens patró d'interacció social.
Resumo:
The oocyst wall of coccidian parasites is a robust structure that is resistant to a variety of environmental and chemical insults. This resilience allows oocysts to survive for long periods, facilitating transmission from host to host. The wall is bilayered and is formed by the sequential release of the contents of two specialized organelles - wall forming body 1 and wall forming body 2 - found in the macrogametocyte stage of Coccidia. The oocyst wall is over 90% protein but few of these proteins have been studied. One group is cysteine-rich and may be presumed to crosslink via disulphide bridges, though this is yet to be investigated. Another group of wall proteins is rich in tyrosine. These proteins, which range in size from 8-31 kDa, are derived from larger precursors of 56 and 82 kDa found in the wall forming bodies. Proteases may catalyze processing of the precursors into tyrosine-rich peptides, which are then oxidatively crosslinked in a reaction catalyzed by peroxidases. In support of this hypothesis, the oocyst wall has high levels of dityrosine bonds. These dityrosine crosslinked proteins may provide a structural matrix for assembly of the oocyst wall and contribute to its resilience.
Resumo:
Aquest estudi analitza les pràctiques diàries, els valors socials i les actituds de la població catalana en el procés de transició cap a la societat xarxa. Analitza el comportament de les persones a Internet i fora d'Internet, investigant el paper específic dels usos d'Internet a l'hora d'influenciar pràctiques i actituds. Es basa en les respostes a una enquesta de 3.005 individus, una mostra representativa de la població catalana el 2002. L'enquesta es va fer entre el febrer i el maig del 2002, i es basava en entrevistes cara a cara a partir d'un qüestionari de 179 preguntes. Es van utilitzar fonts secundàries per a situar els resultats catalans, particularment sobre els usos d'Internet, en el context global. L'anàlisi es va completar el 2007 incorporant-hi noves dades secundàries. L'estudi va cobrir pràctiques socials de treball, comunicació, sociabilitat, usos d'espai i temps, usos d'Internet, identitat cultural, pràctica política, associacionisme i formació de projectes d'autonomia. Es van construir diversos models estadístics per a proporcionar una anàlisi causal de cada una d'aquestes àrees d'estudi. El descobriment més significatiu fa referència a la relació entre els usos d'Internet i la construcció d'autonomia per part d'actors socials. Fent servir anàlisis factorial, l'estudi va definir cinc índexs d'autonomia que eren estadísticament independents: autonomia personal, autonomia professional, autonomia comunicativa, autonomia corporal i autonomia sociopolítica. Cada un d'aquests índexs d'autonomia independents estan fortament associats amb la freqüència i la intensitat de l'ús d'Internet, i les relacions observades es mantenen quan es controlen per variables sociodemogràfiques. A partir d'aquest estudi es pot afirmar que Internet és una plataforma important per a la construcció d'autonomia en la societat xarxa. En general, la societat catalana sembla que canviï de manera similar a altres societats en transició, amb l'èmfasi afegit del paper del territori i la família a l'hora d'enfortir les relacions socials, amb la contribució positiva d'Internet a un dens patró d'interacció social.
Resumo:
Aquest estudi analitza les pràctiques diàries, els valors socials i les actituds de la població catalana en el procés de transició cap a la societat xarxa. Analitza el comportament de les persones a Internet i fora d'Internet, investigant el paper específic dels usos d'Internet a l'hora d'influenciar pràctiques i actituds. Es basa en les respostes a una enquesta de 3.005 individus, una mostra representativa de la població catalana el 2002. L'enquesta es va fer entre el febrer i el maig del 2002, i es basava en entrevistes cara a cara a partir d'un qüestionari de 179 preguntes. Es van utilitzar fonts secundàries per a situar els resultats catalans, particularment sobre els usos d'Internet, en el context global. L'anàlisi es va completar el 2007 incorporant-hi noves dades secundàries. L'estudi va cobrir pràctiques socials de treball, comunicació, sociabilitat, usos d'espai i temps, usos d'Internet, identitat cultural, pràctica política, associacionisme i formació de projectes d'autonomia. Es van construir diversos models estadístics per a proporcionar una anàlisi causal de cada una d'aquestes àrees d'estudi. El descobriment més significatiu fa referència a la relació entre els usos d'Internet i la construcció d'autonomia per part d'actors socials. Fent servir anàlisis factorial, l'estudi va definir cinc índexs d'autonomia que eren estadísticament independents: autonomia personal, autonomia professional, autonomia comunicativa, autonomia corporal i autonomia sociopolítica. Cada un d'aquests índexs d'autonomia independents estan fortament associats amb la freqüència i la intensitat de l'ús d'Internet, i les relacions observades es mantenen quan es controlen per variables sociodemogràfiques. A partir d'aquest estudi es pot afirmar que Internet és una plataforma important per a la construcció d'autonomia en la societat xarxa. En general, la societat catalana sembla que canviï de manera similar a altres societats en transició, amb l'èmfasi afegit del paper del territori i la família a l'hora d'enfortir les relacions socials, amb la contribució positiva d'Internet a un dens patró d'interacció social.
Resumo:
Thioredoxins comprise a conserved family of redox regulators involved in many biological processes, including stress resistance and aging. We report that the C. elegans thioredoxin TRX-1 acts in ASJ head sensory neurons as a novel modulator of the insulin-like neuropeptide DAF-28 during dauer formation. We show that increased formation of stress-resistant, long-lived dauer larvae in mutants for the gene encoding the insulin-like neuropeptide DAF-28 requires TRX-1 acting in ASJ neurons, upstream of the insulin-like receptor DAF-2. Genetic rescue experiments demonstrate that redox-independent functions of TRX-1 specifically in ASJ neurons are needed for the dauer formation constitutive (Daf-c) phenotype of daf-28 mutants. GFP reporters of trx-1 and daf-28 show opposing expression patterns in dauers (i.e. trx-1 is up-regulated and daf-28 is down-regulated), an effect that is not observed in growing L2/L3 larvae. In addition, functional TRX-1 is required for the down-regulation of a GFP reporter of daf-28 during dauer formation, a process that is likely subject to DAF-28-mediated feedback regulation. Our findings demonstrate that TRX-1 modulates DAF-28 signaling by contributing to the down-regulation of daf-28 expression during dauer formation. We propose that TRX-1 acts as a fluctuating neuronal signaling modulator within ASJ neurons to monitor the adjustment of neuropeptide expression, including insulin-like proteins, during dauer formation in response to adverse environmental conditions.
Resumo:
OBJECTIVES/HYPOTHESIS: Facial nerve regeneration is limited in some clinical situations: in long grafts, by aged patients, and when the delay between nerve lesion and repair is prolonged. This deficient regeneration is due to the limited number of regenerating nerve fibers, their immaturity and the unresponsiveness of Schwann cells after a long period of denervation. This study proposes to apply glial cell line-derived neurotrophic factor (GDNF) on facial nerve grafts via nerve guidance channels to improve the regeneration. METHODS: Two situations were evaluated: immediate and delayed grafts (repair 7 months after the lesion). Each group contained three subgroups: a) graft without channel, b) graft with a channel without neurotrophic factor; and c) graft with a GDNF-releasing channel. A functional analysis was performed with clinical observation of facial nerve function, and nerve conduction study at 6 weeks. Histological analysis was performed with the count of number of myelinated fibers within the graft, and distally to the graft. Central evaluation was assessed with Fluoro-Ruby retrograde labeling and Nissl staining. RESULTS: This study showed that GDNF allowed an increase in the number and the maturation of nerve fibers, as well as the number of retrogradely labeled neurons in delayed anastomoses. On the contrary, after immediate repair, the regenerated nerves in the presence of GDNF showed inferior results compared to the other groups. CONCLUSIONS: GDNF is a potent neurotrophic factor to improve facial nerve regeneration in grafts performed several months after the nerve lesion. However, GDNF should not be used for immediate repair, as it possibly inhibits the nerve regeneration.
Resumo:
The ciliary body and iris are pigmented epithelial structures in the anterior eye segment that function to maintain correct intra-ocular pressure and regulate exposure of the internal eye structures to light, respectively. The cellular and molecular factors that mediate the development of the ciliary body and iris from the ocular pigmented epithelium remain to be fully elucidated. Here, we have investigated the role of Notch signaling during the development of the anterior pigmented epithelium by using genetic loss- and gain-of-function approaches. Loss of canonical Notch signaling results in normal iris development but absence of the ciliary body. This causes progressive hypotony and over time leads to phthisis bulbi, a condition characterized by shrinkage of the eye and loss of structure/function. Conversely, Notch gain-of-function results in aniridia and profound ciliary body hyperplasia, which causes ocular hypertension and glaucoma-like disease. Collectively, these data indicate that Notch signaling promotes ciliary body development at the expense of iris formation and reveals novel animal models of human ocular pathologies.
Resumo:
The FIT trial was conducted to evaluate the safety and efficacy of 90Y-ibritumomab tiuxetan (0.4 mCi/kg; maximum dose 32 mCi) when used as consolidation of first complete or partial remission in patients with previously untreated, advanced-stage follicular lymphoma (FL). Patients were randomly assigned to either 90Y-ibritumomab treatment (n = 207) or observation (n = 202) within 3 months (mo) of completing initial induction therapy (chemotherapy only: 86%; rituximab in combination with chemotherapy: 14%). Response status prior to randomization did not differ between the groups: 52% complete response (CR)/CR unconfirmed (CRu) to induction therapy and 48% partial response (PR) in the 90Y-ibritumomab arm vs 53% CR/CRu and 44% PR in the control arm. The primary endpoint was progression-free survival (PFS) of the intent-to-treat (ITT) population. Results from the first extended follow-up after a median of 3.5 years revealed a significant improvement in PFS from the time of randomization with 90Y-ibritumomab consolidation compared with control (36.5 vs 13.3 mo, respectively; P < 0.0001; Morschhauser et al. JCO. 2008; 26:5156-5164). Here we report a median follow-up of 66.2 mo (5.5 years). Five-year PFS was 47% in the 90Y-ibritumomab group and 29% in the control group (hazard ratio (HR) = 0.51, 95% CI 0.39-0.65; P < 0.0001). Median PFS in the 90Y-ibritumomab group was 49 mo vs 14 mo in the control group. In patients achieving a CR/CRu after induction, 5-year PFS was 57% in the 90Y-ibritumomab group, and the median had not yet been reached at 92 months, compared with a 43% 5-year PFS in the control group and a median of 31 mo (HR = 0.61, 95% CI 0.42-0.89). For patients in PR after induction, the 5-year PFS was 38% in the 90Y-ibritumomab group with a median PFS of 30 mo vs 14% in the control group with a median PFS of 6 mo (HR = 0.38, 95% CI 0.27-0.53). Patients who had received rituximab as part of induction treatment had a 5-year PFS of 64% in the 90Y-ibritumomab group and 48% in the control group (HR = 0.66, 95% CI 0.30-1.47). For all patients, time to next treatment (as calculated from the date of randomization) differed significantly between both groups; median not reached at 99 mo in the 90Y-ibritumomab group vs 35 mo in the control group (P < 0.0001). The majority of patients received rituximab-containing regimens when treated after progression (63/82 [77%] in the 90Y-ibritumomab group and 102/122 [84%] in the control group). Overall response rate to second-line treatment was 79% in the 90Y-ibritumomab group (57% CR/CRu and 22% PR) vs 78% in the control arm (59% CR/CRu, 19% PR). Five-year overall survival was not significantly different between the groups; 93% and 89% in the 90Y-ibritumomab and control groups, respectively (P = 0.561). To date, 40 patients have died; 18 in the 90Y-ibritumomab group and 22 in the control group. Secondary malignancies were diagnosed in 16 patients in the 90Y-ibritumomab arm vs 9 patients in the control arm (P = 0.19). There were 6 (3%) cases of myelodysplastic syndrome (MDS)/acute myelogenous leukemia (AML) in the 90Y-ibritumomab arm vs 1 MDS in the control arm (P = 0.063). In conclusion, this extended follow-up of the FIT trial confirms the benefit of 90Y-ibritumomab consolidation with a nearly 3 year advantage in median PFS. A significant 5-year PFS improvement was confirmed for patients with a CR/CRu or a PR after induction. Effective rescue treatment with rituximab-containing regimens may explain the observed no difference in overall survival between both patient groups who were - for the greater part - rituximab-naïve.
Resumo:
We conducted a cross-sectional, hospital-based study between January 2006-March 2008 to estimate the resistance of Mycobacterium tuberculosis to first-line drugs in patients with tuberculosis at a Brazilian hospital. We evaluated the performance of the [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide] (MTT) microplate assay compared with the Bactec-MGIT 960 system for mycobacteria testing. The prevalence of resistance in M. tuberculosis was 6.7%. Multidrug-resistance [resistance to rifampicin (RMP) and isoniazid (INH)], INH-resistance and streptomycin (SM)-resistance accounted for 1%, 3.8% and 3.8% of all resistance, respectively, and all isolates were susceptible to ethambutol (EM). The resistance was primary in four cases and acquired in three cases and previous treatment was associated with resistance (p = 0.0129). Among the 119 M. tuberculosis isolates, complete concordance of the results for INH and EM was observed between the MTT microplate and Bactec-MGIT 960TM methods. The observed agreement for RMP was 99% (sensitivity: 90%) and 95.8% for SM (sensitivity 90.9%), lower than those for other drugs. The MTT colourimetric method is an accurate, simple and low-cost alternative in settings with limited resources.
Resumo:
ATM and PARP-1 are two of the most important players in the cell's response to DNA damage. PARP-1 and ATM recognize and bound to both single and double strand DNA breaks in response to different triggers. Here we report that ATM and PARP-1 form a molecular complex in vivo in undamaged cells and this association increases after gamma-irradiation. ATM is also modified by PARP-1 during DNA damage. We have also evaluated the impact of PARP-1 absence or inhibition on ATM-kinase activity and have found that while PARP-1 deficient cells display a defective ATM-kinase activity and reduced gamma-H2AX foci formation in response to gamma-irradiation, PARP inhibition on itself is able to activate ATM-kinase. PARP inhibition induced gamma H2AX foci accumulation, in an ATM-dependent manner. Inhibition of PARP also induces DNA double strand breaks which were dependent on the presence of ATM. As consequence ATM deficient cells display an increased sensitivity to PARP inhibition. In summary our results show that while PARP-1 is needed in the response of ATM to gamma irradiation, the inhibition of PARP induces DNA double strand breaks (which are resolved in and ATM-dependent pathway) and activates ATM kinase.