Adhesive restoration of endodontically treated premolars: influence of posts on cuspal deflection

To determine, by means of a non-destructive experimental procedure, the effectiveness of adhesive restorations in reducing the cuspal deflection of endodontically treated premolars, with or without root canal fiber posts.To determine, by means of a non-destructive experimental procedure, the effectiveness of adhesive restorations in reducing the cuspal deflection of endodontically treated premolars, with or without root canal fiber posts. MATERIALS AND METHODS: The cuspal deflection of ten sound, intact maxillary premolars was evaluated. A loading device induced deformation by axial force (ranging from 98 to 294 N) applied on the occlusal surface of teeth while laser sensors registered the amount of deflection. Once tested, teeth were endodontically treated and the marginal ridges were removed. The teeth were randomly divided into two groups and restored with: group 1) dual curing adhesive, flowable composite, and microhybrid composite; group 2) the same materials associated with root canal glass fiber post and composite cement. The cuspal deflection test was repeated with the same protocol after restorative procedures, allowing a direct comparison of the same samples. Statistical analysis was performed using ANOVA at a significance level of 0.05. RESULTS: Different average cuspal deflection was detected in the two groups: composite resin with post insertion resulted in lower deformation compared with composite alone. Mean deflection ranged from 3.43 to 12.17 μm in intact teeth, from 14.42 to 26.93 μm in group 1, and from 15.35 to 20.39 μm in group 2. ANOVA found significant differences (p = 0.02). CONCLUSION: Bonded composite restorations with fiber posts may be more effective than composite alone in reducing the cuspal deflection in endodontically treated premolars in which the marginal ridges have been lost

Radical-induced purine lesion formation is dependent on DNA helical topology

AbstractHerein we report the quantification of purine lesions arising from gamma-radiation sourced hydroxyl radicals (HO•) on tertiary dsDNA helical forms of supercoiled (SC), open circular (OC), and linear (L) conformation, along with single-stranded folded and non-folded sequences of guanine-rich DNA in selected G-quadruplex structures. We identify that DNA helical topology and folding plays major, and unexpected, roles in the formation of 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxo-dG) and 8-oxo-7,8-dihydro-2'-deoxyadenosine (8-oxo-dA), along with tandem-type purine lesions 5′,8-cyclo-2′-deoxyguanosine (5′,8-cdG) and 5′,8-cyclo-2′-deoxyadenosine (5′,8-cdA). SC, OC, and L dsDNA conformers together with folded and non-folded G-quadruplexes d[TGGGGT]4 (TG4T), d[AGGG(TTAGGG)3] (Tel22), and the mutated tel24 d[TTGGG(TTAGGG)3A] (mutTel24) were exposed to HO• radicals and purine lesions were then quantified via stable isotope dilution LC-MS/MS analysis. Purine oxidation in dsDNA follows L > OC ≫ SC indicating ..

Endovascular management of giant visceral artery aneurysms

Endovascular management of small visceral artery aneurysms is an established treatment with satisfactory outcomes. However, when size exceeds 5 cm visceral aneurysms are considered as “giant” (giant visceral artery aneurysms or GVAAs) and management is significantly more complex. Between August 2007 and June 2019 eleven cases of GVAAs that were endovascularly treated were retrospectively reviewed and included in this single center study. Mean size was 80 mm (± 26.3 mm) x 46 mm (+ -11.8 mm). Nine of the lesions were true aneurysms, and two were pseudoaneurysms. In 8 patients, the lesion was causing compression symptoms in the surrounding organs, one patient developed a contained rupture while 2 patients were completely asymptomatic. However, all patients were hemodynamically stable at the time of treatment. Technical success was defined as immediate complete exclusion of the aneurysmal sac, and clinical success as complete relief from clinical symptoms. Follow-up was performed with CT angiography, ultrasound and clinical examination. Mean follow-up was 45 months (range 6–84). Technical and clinical success were both 91%. Complications were one lack of control of contained rupture that was subsequently operated, one case of self-limiting non-target spleen embolization and one case of splenic abscess. Three patients died, one due to the contained rupture 15 days after procedure, the other two for other causes and occurred during the long-term follow-up. This series suggests that endovascular treatment of giant visceral artery aneurysms and pseudoaneuryms is a valid minimally invasive solution with very satisfactory immediate and long-term outcomes unless the aneurysm is already ruptured. A variety of endovascular tools may be required for successful treatment

New insights into the reaction paths of hydroxyl radicals with purine moieties in DNA and double-stranded oligodeoxynucleotides

The reaction of hydroxyl radical (HO•) with DNA produces many primary reactive species and many lesions as final products. In this study, we have examined the optical spectra of intermediate species derived from the reaction of HO• with a variety of single- and double-stranded oligodeoxynucleotides and ct-DNA in the range of 1 µs to 1 ms by pulse radiolysis using an Intensified Charged Coupled Device (ICCD) camera. Moreover, we applied our published analytical protocol based on an LC-MS/MS system with isotopomeric internal standards to enable accurate and precise measurements of purine lesion formation. In particular, the simultaneous measurement of the four purine 50,8-cyclo-20-deoxynucleosides (cPu) and two 8-oxo-7,8-dihydro-20-deoxypurine (8-oxo-Pu) was obtained upon reaction of genetic material with HO• radicals generated either by γ-radiolysis or Fenton-type reactions. Our results contributed to the debate in the literature regarding absolute level of lesions, method of HO• radical generation, 50R/50S diastereomeric ratio in cPu, and relative abundance between cPu and 8-oxo-Pu.Fil: Chatgilialoglu, Chryssostomos. Istituto Per la Sintesi Organica E la Fotoreattivita, Bologna; ItaliaFil: Krokidis, Marios G.. Consiglio Nazionale delle Ricerche; ItaliaFil: Masi, Annalisa. Consiglio Nazionale delle Ricerche; ItaliaFil: Barata Vallejo, Sebastian. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; ArgentinaFil: Ferreri, Carla. Consiglio Nazionale delle Ricerche; ItaliaFil: Terzidis, Michael A.. Consiglio Nazionale delle Ricerche; ItaliaFil: Szreder, Tomasz. Institute of Nuclear Chemistry and Technology; PoloniaFil: Bobrowski, Krzysztof. Institute of Nuclear Chemistry and Technology; Poloni

Describing the chemical bonding in C70 and C70O3 - a quantum chemical topology study

C-c-C-c and C-a-C-b bonds in C-70 have dominant characteristics of double bonds, whereas the remaining six other types of bonds are single bonds with contributions from pi-electron density. `Single' bonds can act as active sites in chemical reactions which would typically require a multiple bond, such as addition of an ozone molecule, due to the fact that all adjacent bonds can serve as an efficient source of pi-electron density. Thus any alteration in the electron density distribution following functionalization has far-reaching impact. We note that formation of the most stable ozonide isomer causes the smallest total perturbation in the electron density of the parent fullerene and C-C bond evolution correlates well with the shape of the minimum energy path for the ozone ring opening reaction on the fullerene surface. Finally, we observe that the O-O bond in C70O3 is protocovalent, and as such resembles the O-O bond in H2O2. (C) 2014 Elsevier B.V. All rights reserved