Approach to juxtarenal inflammatory aneurysms

The incidence of inflammatory abdominal aortic aneurysm (IAAA) in a late review of the literature is estimated about 2-15% overall aortic aneurysms. In our data this type of aneurysm is 3.6 overall aortic aneurysms treated. In the majority of the cases, IAAA is juxtarenal or infrarenal. Ethiopathogenesis of IAAA till today is not certain. Recent hypothesis on IAAA attribute the same ethiopathogenesis in both atherosclerotic and inflammatory aneurysm. The interaction of genetic, environmental and infective factors should be able to determine an autoimmune inflammatory reaction of variable severity. 80% of the patients suffering from IAAA present abdominal or lumbar pain, loss of weight and increase of the RC sedimentation velocity. The IAAA's natural history goes to rupture. Entrapment of nearstanding organs totally involved in the fibrotic process is the most frequent complication. Usually there is a compression of the ureter and the duodenum with consequenced hydroureteronephrosis and bowel obstruction. Preoperative diagnosis is possible; CT scan and MRI guarantee and accuracy about 90%. Intraoperatively the external wall of IAAA appears whitish and translucent and always there are tenacious adhesion given by the avventital wounds inflammation. Confirm is given by the histological examination of the aneurysmatic wall and peravventitial tissues. Our experience and a late review of the literature concorde that surgical indication for the treatment of IAAA is the same for the atherosclerotic one. This conviction is supported by the fact that the diagnostic methodical evolution and the improvement in mininvasive surgical technique lowered perioperating morbility and mortaliy. We prefer, according with many authors, retroperitoneal approach to juxtarenal IAAA, instead of standardized transperitoneal access with xifo-pubical or transversal under costal incision. This approach offers some advantages as easier exposition of aorta, whose postero-lateral wall is hardly ever involved in inflammatory process, little duodenum's and left renal veins manipulation and low incidence of paralytic ileum and respiratory disease. Endovascular surgery hasn't in this moment any role in juxtarenal IAAA treatment because this type of aneurysm has inadequate proximal neck. In the future, probably, endovascular repair will be possible using a new type of endograft with renal legs. Often surgical treatment is inadequate to control retroperitorenal fibrosis and so surgeon has to use perioperating pharmacolocical therapy.     

INFLUENCE OF PROTAPER FINISHING FILES AND SODIUM HYPOCHLORITE ON CLEANING AND SHAPING OF MANDIBULAR CENTRAL INCISORS – A HISTOLOGICAL ANALYSIS

Objective:

This study investigated the influence of the last apical instrument of the ProTaper system with and without 2.5% sodium hypochlorite for cleaning mandibular central incisors.

Material and Methods:

Thirty two mandibular central incisors were divided into six study groups: Group I – F1 instrument with 2.5% sodium hypochlorite; Group II – F1 and F2 with 2.5% sodium hypochlorite; Group III – F1, F2 and F3 with 2.5% sodium hypochlorite; Group IV – F1 with distilled water; Group V – F1 and F2 with distilled water; Group VI – F1, F2 and F3 with distilled water. The two remaining teeth comprised the negative control group. The specimens were prepared following the principles of the technique suggested by the manufacturer and then submitted to histological preparation and morphometric analysis. Data were analyzed statistically by the Kruskal Wallis test at 1% significance level.

Results:

There was statistically significant difference (p<0.01) between all study groups, except between Groups I and VI.

Conclusions:

It was concluded that no technique allowed complete cleaning of the root canals. However, the technique of finishing preparation of the apical third with the F3 instrument with 2.5% sodium hypochlorite irrigation was the most effective.     

Fibronectin upregulation in human temporomandibular joint disks with internal derangement

Fibronectin is a large fibril-forming extracellular glycoprotein that seems to be involved in joint diseases. The objective of this study was to investigate the expression of fibronectin in human temporomandibular joint disks obtained from patients with internal derangement and varying extents of disk tissue degeneration/regeneration with that of temporomandibular joint disks free of significant morphological alterations by means of immunohistochemical methods. Twelve adult human temporomandibular joint disks (10 diseased disks and 2 normal disks) were used in this study. Temporomandibular joint disks were fixed in 10% buffered formalin. Sections were then immunohistochemically processed using a monoclonal antibody specific to human fibronectin and streptavidin-biotin detection methods. Positive reactions to fibronectin were found in normal and diseased disk tissues but to a different extent. Normal disk tissues revealed weak fibronectin expression, which was mainly located along the collagen bundles. Temporomandibular joint disks with internal derangement exhibited a higher immunoreactivity. Distinct reticular fibronectin structures were found inside the diseased disk, particularly nearby the newly formed blood vessels, tears, and clefts. In the covering layer of the disk surface, fibronectin was expressed in a fascicular pattern running parallel to the disk surface. The findings suggest that temporomandibular joint disk tissue can express fibronectin and that the expression is more pronounced in disk specimens of patients with internal derangement of the temporomandibular joint, supporting a role of this glycoprotein in the degeneration/regeneration processes of human temporomandibular joint disk tissue.     

Disentangling dynamic networks: Separated and joint expressions of functional connectivity patterns in time

Resting‐state functional connectivity (FC) is highly variable across the duration of a scan. Groups of coevolving connections, or reproducible patterns of dynamic FC (dFC), have been revealed in fluctuating FC by applying unsupervised learning techniques. Based on results from k‐means clustering and sliding‐window correlations, it has recently been hypothesized that dFC may cycle through several discrete FC states. Alternatively, it has been proposed to represent dFC as a linear combination of multiple FC patterns using principal component analysis. As it is unclear whether sparse or nonsparse combinations of FC patterns are most appropriate, and as this affects their interpretation and use as markers of cognitive processing, the goal of our study was to evaluate the impact of sparsity by performing an empirical evaluation of simulated, task‐based, and resting‐state dFC. To this aim, we applied matrix factorizations subject to variable constraints in the temporal domain and studied both the reproducibility of ensuing representations of dFC and the expression of FC patterns over time. During subject‐driven tasks, dFC was well described by alternating FC states in accordance with the nature of the data. The estimated FC patterns showed a rich structure with combinations of known functional networks enabling accurate identification of three different tasks. During rest, dFC was better described by multiple FC patterns that overlap. The executive control networks, which are critical for working memory, appeared grouped alternately with externally or internally oriented networks. These results suggest that combinations of FC patterns can provide a meaningful way to disentangle resting‐state dFC. Hum Brain Mapp 35:5984–5995, 2014. © 2014 The Authors. Human Brain Mapping published by Wiley Periodicals, Inc.