Comparación de la profundidad de fotopolimerización de resinas fluidas a través de 4 porcelanas de alta opacidad / Comparison of the light cure depth of flowable resins through 4 high-opacity porcelains

Se estudia la profundidad de polimerización que se obtiene en resinas compuestas fluidas al ser iluminadas a través de bloques de cerámica de distinta composición y distintos grosores. En formadores metálicos cilíndricos de 4mm de alto y 6mm de diámetro se depositó resina fluida hasta enrasar en superficie y posteriormente se iluminó por 60 seg interponiendo las distintas cerámicas entre la luz y la resina. Se utilizó una lámpara led para la iluminación del material. Algunos de los grupos en estudio presentaron diferencias significativas entre sí dependiendo del grosor de la cerámica y el tipo de ella. Es posible polimerizar resina fluida a través de cerámicas de distinta opacidad obteniendo grosores de resina mayores a los que se establecen para la línea de cementación de las restauraciones de cerámica libre de metal. Relevancia: A través de bloques de cerámica de diferente opacidad y composición se obtiene polimerización de resina compuesta fluida, lo que permitiría usar esta resina como medio de cementación de restauraciones a base de cerámicas cuyos grosores permitan el paso de la luz.

We studied the depth of cure obtained in flowable composite resins when illuminated through ceramic blocks of different composition and different thicknesses. The flowable composite resin was deposited in forming metal cylinders of 4mm of high and 6mm of diameter, brought to volume and then illuminated for 60 sec interposing the different ceramics between light and resin. A LED lamp was used to illuminate the material. Some of the groups exhibited significant differences among them depending on the thickness of the ceramic and its type. Flowable resin may polymerize through ceramics of different thicknesses and could be used for the cementation of ceramic restorations.

Thalamic involvement and its impact on clinical disability in patients with multiple sclerosis: a diffusion tensor imaging study at 3T.

BACKGROUND AND PURPOSE: Several studies suggest that grey matter involvement may play a role in multiple sclerosis (MS) pathology. Diffusion tensor imaging (DTI) at 3T was used to investigate the presence of damage to the normal-appearing thalamus in MS and its relationship with disability. MATERIALS AND METHODS: Twenty-four patients with relapsing-remitting (RR, n = 13, age = 41.7 +/- 6.1, Expanded Disability Status Scale [EDSS] score = 2.2 +/- 1.2) and secondary-progressive (n = 11, age = 46.9 +/- 9.6, EDSS = 5.9 +/- 1.0) MS and 24 age- and sex-matched healthy volunteers were studied. Fractional anisotropy (FA) and mean diffusivity (MD) were measured in regions of interest of normal-appearing thalamus. We examined group differences in MD and FA and correlations between DTI-derived metrics and clinical or imaging measures of disease. RESULTS: Patients with MS had higher thalamic FA (P < .0001) and MD (P = .035) than volunteers. MD values correlated with the Paced Auditory Serial Addition Task (r = -0.43, P = .034) and motor EDSS (r = 0.47, P = .021) scores. In patients with RRMS, MD values correlated with global EDSS (r = 0.75, P = .003) and motor EDSS (r = 0.68, P = .010). Correlations were found between MD values and T1 and T2 lesion load (r = 0.58, P < .05) and brain parenchymal fraction (r = -0.46, P < .05). CONCLUSIONS: DTI was able to detect abnormalities in normal-appearing thalamus of patients with MS. The strength of association between thalamic DTI measures and functional impairment was in the same range as those seen with standard MR imaging disease measures. The assessment of the integrity of the thalamus with DTI is a promising metric as a marker of disease for future studies.

A case study on the effect of neutralizing antibodies to interferon beta 1b in multiple sclerosis patients followed for 3 years with monthly imaging.

Interferon beta (IFN-beta) is among the first-line treatment options for patients with multiple sclerosis (MS). A potential caveat of therapy, however, is the development of neutralizing antibodies (NAb) and/or neutralizing activity (NA) non-antibody mediated, although debate is still ongoing as to whether NAb significantly hampers the efficacy of the drug or rather represents an immunologically irrelevant epiphenomenon. In the present study, we describe the effect of NAb on IFN-beta-1b through clinical and magnetic resonance imaging (MRI) outcome measures of five relapsing-remitting multiple sclerosis (RRMS) patients who were treated with 250 mug of subcutaneously administered IFN-beta-1b every other day and developed NAb at varying titres and times during the course of therapy. Despite the small number of NAb(+) patients, heterogeneity in MRI/clinical response to IFN-beta-1b was identified. Response to IFN-beta-1b therapy was observed in the absence or presence of NAb. Also observed was failure to IFN-beta-1b coincident with high and sustained NAb titres, but also before NAb development or in the presence of low NAb titres. Multiple MRI and NAb measurements performed within the same individual allow for a better description of the complex heterogeneous response to IFN-beta-1b with respect to NAb occurrence.

Sera from adult patients with cystic fibrosis contain antibodies to Pseudomonas aeruginosa type III apparatus.

Expression of type III proteins of Pseudomonas aeruginosa in patients with cystic fibrosis (CF) was investigated by measuring the immune response against components of the type III pathway. Twenty-three of the 33 sera contained antibodies against PcrV, a protein involved in translocation of type III cytotoxins into eukaryotic cells, and 11 of 33 had antibodies against ExoS, while most CF sera contained antibodies against PopB and PopD, components of the type III apparatus. These data indicate that P. aeruginosa commonly expresses components of the type III translocation apparatus in adult CF patients.

Endothelial nitric oxide synthase as a potential susceptibility gene in the pathogenesis of emphysema in alpha1-antitrypsin deficiency.

A role for endothelial nitric oxide synthase (NOS3) in the susceptibility of individuals with alpha1-antitrypsin (alpha1AT) deficiency to destructive lung disease was evaluated. Six polymorphic sites were identified within the NOS3 gene (i.e., -924A/G, -788C/T, -691C/T, 774C/T, 894G/T, and 1998C/G). The genotype distribution was determined in 339 patients and 94 control individuals. Frequency of the 774T allele in severely affected individuals was 0.417 versus 0.269 in control subjects (P = 0.018), whereas the 894T allele frequency was 0.427 versus 0.280 in control subjects (P = 0.024). Patients with less severe lung disease had the 774T and 894T allele frequencies of 0.289 and 0.344, respectively, similar to frequencies in a control group (P > 0.3). No direct correlation between pulmonary function and five other NOS3 polymorphisms was observed. Thus, functional allelic variants that are in linkage disequilibrium with the 774C/T and 894G/T may be present in the specified genomic area. These data are consistent with a modulatory role for NOS3 in destructive lung disease associated with alpha1AT deficiency.

Influence of 6-hydroxydopamine on ethanol narcosis in mice.

The effects of 6-hydroxydopamine (6-OHDA) i.c.v. on ethanol-induced narcosis were studied in mice, either untreated or pretreated with alpha-methyl-p-tyrosine (AMPT), p-chlorophenylalanine (PCPA) or 5-hydroxytryptophan (5-HTP). Mice treated with 6-OHDA 200 micrograms i.c.v., exhibited longer ethanol narcosis time than untreated controls. This effect was significantly increased when mice treated with 6-OHDA received AMPT (inhibitor of catecholamine biosynthesis) or 5-HTP (precursor or serotonin biosynthesis). After administration of PCPA (inhibitor of tryptophan hydroxylase) 6-OHDA did not prolong ethanol narcosis. Alcohol blood levels at awakening time were not significantly influenced by 6-OHDA. These results are consistent with the idea that a decrease in brain noradrenaline as well as an increase in brain serotonin enhance the narcotic action of ethanol, while both, the increase in brain noradrenaline and the decrease in brain serotonin shorten ethanol narcosis.

Influence of 6-hydroxydopamine on ethanol narcosis in mice.

The effects of 6-hydroxydopamine (6-OHDA) i.c.v. on ethanol-induced narcosis were studied in mice, either untreated or pretreated with alpha-methyl-p-tyrosine (AMPT), p-chlorophenylalanine (PCPA) or 5-hydroxytryptophan (5-HTP). Mice treated with 6-OHDA 200 micrograms i.c.v., exhibited longer ethanol narcosis time than untreated controls. This effect was significantly increased when mice treated with 6-OHDA received AMPT (inhibitor of catecholamine biosynthesis) or 5-HTP (precursor or serotonin biosynthesis). After administration of PCPA (inhibitor of tryptophan hydroxylase) 6-OHDA did not prolong ethanol narcosis. Alcohol blood levels at awakening time were not significantly influenced by 6-OHDA. These results are consistent with the idea that a decrease in brain noradrenaline as well as an increase in brain serotonin enhance the narcotic action of ethanol, while both, the increase in brain noradrenaline and the decrease in brain serotonin shorten ethanol narcosis.