Nanohardness reduction and root dentine erosion after final irrigation with ethylenediaminetetraacetic, etidronic and peracetic acids.

AIM: To evaluate the nanohardness reduction and erosion in root canal dentine after application of 17% ethylenediaminetetraacetic acid (EDTA), 9% etidronic acid (HEBP) and 2% peracetic acid (PAA) either alone or combined with sodium hypochlorite (NaOCl). METHODOLOGY: One hundred and sixty single-rooted teeth were decoronated and their root canals were chemomechanically prepared. For the nanohardness evaluation, 80 roots with instrumented canals were split longitudinally into two halves. Dentine blocks with a length of 7 mm were obtained from the middle third of one half of each tooth and were embedded in epoxy resin blocks exposing the root canal walls. Initial nanohardness values of root canal dentine were measured for each specimen using a nanoindenter with a Berkovich tip. The specimens were divided into seven experimental (n = 10) and one control (n = 10) group according to the final irrigation regimens: Group 1: 2.5% NaOCl, Group 2: 17% EDTA, Group 3: 2.5% NaOCl-17% EDTA, Group 4: 2% PAA, Group 5: 2.5% NaOCl-2% PAA, Group 6: 9% HEBP, Group 7: 2.5% NaOCl + 9% HEBP and Group 8: Distilled water (control). The measurement of the nanohardness values was repeated for each specimen after being exposed to the irrigants. The nanaohardness reduction of each sample was calculated and recorded. The other 80 instrumented root canals were used for scanning electron microscope (SEM) evaluation. First, they were irrigated with the same protocols stated above and longitudinally split into two halves. One half of each root canal was viewed using SEM for the amount of erosion. The erosion scores were recorded. Data were analysed statistically using Kruskal-Wallis and Bonferroni-adjusted Mann-Whitney U-tests with a significance level of 0.05. RESULTS: Use of etidronic acid and NaOCl + HEBP reduced the nanohardness values significantly more than the other experimental solutions (P < 0.05). There was no significant difference between the values for the nanohardness reduction in the samples irrigated with a single chelator and chelator combined with NaOCl (P > 0.05). Peritubular and intertubular erosion were observed in the samples irrigated with HEBP and NaOCl + HEBP. CONCLUSION: Final irrigation of root canals using etidronic acid alone or combined with NaOCl was associated with structural alterations in root canal dentine of extracted teeth.

Upper-limb actuated exoskeleton for muscular dystrophy patients: preliminary results.

Being able to perform a lost movement is an important experience towards increased independence and self-esteem, particularly for neuromuscular patients, who see their muscles weaken day after day. In this pilot study, preliminary results on the testing of a motorized upper-limb exoskeleton for muscular dystrophy patients are presented. The mechatronic system is a five Degrees of Freedom exoskeleton, which acts at shoulder, elbow, and wrist levels. It is designed to help severely impaired people to regain independence during daily-life activities. While wearing the exoskeleton, the user has the direct control of the system by actively piloting the position of end-effector by means of joystick or vocal control. The usability of the system and a quantitative assessment of arm functionality with and without the exoskeleton are evaluated on five muscular dystrophy patients. According to the objective functional benefit evaluation performed through the PUL scale, all participants strongly increased their range of motion and they were able to perform activities that were not possible without the exoskeleton, such as such as feeding, playing activities at the table, combing hair or using a keyboard. As for the evaluation of self-perceived functional benefit, four patients reflected the effective measured functional improvement. System usability has been evaluated to be good.

Responses of Mytilus galloprovincialis hemocytes to environmental strains of Vibrio parahaemolyticus, Vibrio alginolyticus, Vibrio vulnificus.

Marine bivalves are exposed to different types of bacteria in the surrounding waters, in particular of the Vibrio genus. In the hemocytes of the mussel Mytilus spp. immune responses to different vibrios have been largely characterized. However, little information is available on the hemocyte responses to human pathogenic vibrios commonly detected in coastal waters and bivalve tissues that are involved in seafood-borne diseases. In this work, functional parameters of the hemocytes from the Mediterranean mussel M. galloprovincialis were evaluated in response to in vitro challenge with different vibrios isolated from environmental samples of the Adriatic sea (Italy): V. parahaemolyticus Conero, V. alginolyticus 1513 and V. vulnificus 509. V. parahaemolyticus ATCC 43996 was used for comparison. At the 50:1 bacteria hemocyte ratio, only V. parahaemolyticus strains induced significant lysosomal membrane destabilisation. Stimulation of extracellular lysozyme release, total ROS, O2- and NO production were observed, although to different extents and with distinct time courses for different vibrios, V. vulnificus 509 in particular. Further comparisons between V. parahaemolyticus Conero and V. vulnificus 509 showed that only the latter induced dysregulation of the phosphorylation state of p38 MAP Kinase and apoptotic processes. The results indicate that mussel hemocytes can mount an efficient immune response towards V. parahaemolyticus and V. alginolyticus strains, whereas V. vulnificus 509 may affect the hemocyte function. This is the first report on immune responses of mussels to local environmental isolates of human pathogenic vibrios. These data reinforce the hypothesis that Mytilus hemocytes show specific responses to different vibrio species and strains.

Environmental nanoparticles are significantly over-expressed in acute myeloid leukemia.

The increase in the incidence of acute myeloid leukemia (AML) may suggest a possible environmental etiology. PM2.5 was declared by IARC a Class I carcinogen. No report has focused on particulate environmental pollution together with AML. The study investigated the presence and composition of particulate matter in blood with a Scanning Electron Microscope coupled with an Energy Dispersive Spectroscope, a sensor capable of identifying the composition of foreign bodies. 38 peripheral blood samples, 19 AML cases and 19 healthy controls, were analyzed. A significant overload of particulate matter-derived nanoparticles linked or aggregated to blood components was found in AML patients, while almost absent in matched healthy controls. Two-tailed Student's t-test, MANOVA and Principal Component Analysis indicated that the total numbers of aggregates and particles were statistically different between cases and controls (MANOVA, P<0.001 and P=0.009 respectively). The particles detected showed to contain highly-reactive, non-biocompatible and non-biodegradable metals; in particular, micro- and nano-sized particles grouped in organic/inorganic clusters, with statistically higher frequency of a subgroup of elements in AML samples. The demonstration, for the first time, of an overload of nanoparticles linked to blood components in AML patients could be the basis for a possible, novel pathogenetic mechanism for AML development.

Changes in adhesion ability of Aeromonas hydrophila during long exposure to salt stress conditions.

AIMS: Stressful environmental conditions influence both bacterial growth and expression of virulence factors. In the present study, we evaluated the influence of NaCl on Aeromonas hydrophila adhesiveness at two temperatures. This agent is often involved in clinical cases; however, its pathogenic potential is still not fully understood. METHODS AND RESULTS: Bacteria were grown in presence of 1·7%, 3·4%, 6·0% NaCl over a 188 day period and then reinoculated in fresh Nutrient Broth with incubation at 4 and 24°C. Bacterial adhesiveness was tested on Hep-2 cells, and specimens were processed for light, scanning and transmission electron microscopy. Adhesive capacity decreased over time with an increase in reduction percentages depending on NaCl concentrations. At 1·7% NaCl, the reduction was apparently temporary and adhesiveness rapidly recovered in revitalized bacteria, while 3·4%, 6·0% NaCl seemed to be detrimental. Normal, elongated and filamentous bacteria retained adhesiveness capability, although with reduced expression, while in spherical cells, this property seemed to be lost or dramatically reduced. CONCLUSIONS: Our study shows that high osmolarity plays a significant role in adhesion inhibition, therefore having possible implications in the pathogenesis of the infections by Aer. hydrophila. SIGNIFICANCE AND IMPACT OF THE STUDY: This study intends to give a contribution to a better understanding of the pathogenic role of this bacterium whose pathogenicity is still under debate.