Pulse Parameters and Thresholds for (ir)Reversible Electroporation on Hepatocellular Carcinoma Cells in Vitro.

Hepatocellular carcinoma is a leading cause of cancer-related death in many parts of the world. Traditional treatment options are not always effective. During the promising minimally invasive electroporation-based therapies, biological cell membranes are exposed to an external, sufficiently high, pulsed electric field which creates so-called nanopores into the lipid bilayer of the cell membrane. These pores can either be permanent (irreversible electroporation (IRE)), leading to apoptosis, or repairable (reversible electroporation (RE)), with continued cell function. In tumor therapy, RE is used to increase the diffusion of a chemotherapeutic drug during electrochemotherapy. For both IRE and RE, the success of the treatment is dependent on application of the appropriate electric field. Therefore, this study aims to define the pulse parameters and thresholds for IRE and RE on hepatocellular carcinoma (HepG2) cells in-vitro.In a custom-made in-vitro setup, HepG2 cell viability (0, 5, 10, and 15 min), and the peak temperature were measured after electroporation with the different IRE and RE pulsing protocols, to determine the most successful settings for IRE and RE. A CAM/PI flow cytometric assay was performed to confirm cell permeabilization for the RE pulsing protocols with the highest cell viability.The results indicated that an IRE pulsing protocol (70 pulses, 100 µs pulse length, and 100 ms interval) with an electric field strength of 4000 V/cm was needed as threshold for almost complete cell death of HepG2 cells. A RE pulsing protocol (8 pulses, 100 µs pulse length, and 1000 ms interval) with an electric field strength of 1000 V/cm was needed as threshold for viable and permeabilized HepG2 cells. The low peak temperatures (max 30.1°C for IRE, max 23.1°C for RE) within this study indicated that the reduction in HepG2 cell viability was caused by the applied electric field and was not a result of Joule heating.

Linking spatial distribution of Rhipicephalus appendiculatus to climatic variables important for the successful biocontrol by Metarhizium anisopliae in Eastern Africa.

Cattle production is constantly threatened by diseases like East Coast fever, also known as theileriosis, caused by the protozoan parasite Theileria parva which is transmitted by ticks such as the brown ear tick, Rhipicephalus appendiculatus. To reduce the extensive use of chemical acaricides, fungal-based microbial control agents such as Metarhizium anisopliae have been tested and show promising results against R. appendiculatus both in field and in semi-field experiments in Africa. However, no known endeavors to link the spatial distribution of R. appendiculatus to climatic variables important for the successful application of M. anisopliae in selected East African countries exists. This work therefore aims to improve the successful application of M. anisopliae against R. appendiculatus by designing a temperature-dependent model for the efficacy of M. anisopliae against three developmental stages (larvae, nymphs, adults) of R. appendiculatus. Afterward a spatial prediction of potential areas where this entomopathogenic fungus might cause a significant epizootic in R. appendiculatus population in three selected countries (Kenya, Tanzania, Uganda) in Eastern Africa were generated. This can help to determine whether the temperature and rainfall at a local or regional scale might give good conditions for application of M. anisopliae and successful microbial control of R. appendiculatus.

History-dependent attachment ofPseudomonas aeruginosato solid-liquid interfaces and the dependence of the bacterial surface density on the residence time distribution.

This study investigates how the recent history of bacteria affects their attachment to a solid-liquid interface. We compare the attachment from a flowing suspension of the bacterium,Pseudomonas aeruginosaPAO1, after one of two histories: (a) passage through a tube packed with glass beads or (b) passage through an empty tube. The glass beads were designed to increase the rate of bacterial interactions with solid-liquid surfaces prior to observation in a flow cell. Analysis of time-lapse microscopy of the bacteria in the flow cells shows that the residence time distribution and surface density of bacteria differ for these two histories. In particular, bacteria exiting the bead-filled tube, in contrast to those bacteria exiting the empty tube, are less likely to attach to the subsequent flow cell window and begin surface growth. In contrast, when we compared two histories defined by different lengths of tubing, there was no difference in either the mean residence time or the surface density. In order to provide a framework for understanding these results, we present a phenomenological model in which the rate of bacterial surface density growth,dN(t)/dt, depends on two terms. One term models the initial attachment of bacteria to a surface, and is proportional to the nonprocessive cumulative residence time distribution for bacteria that attach and detach from the surface without cell division. The second term for the rate is proportional to the bacterial surface density and models surface cell division. The model is in surprisingly good agreement with the data even though the surface growth process is a complex interplay between attachment/detachment at the solid-liquid interface and cell division on the surface.

Dual Task Performance Is Associated with Amyloidosis in Cognitively Healthy Adults.

BACKGROUND: Preclinical Alzheimer's disease (AD) provides an opportunity for the study and implementation of interventions and strategies aimed at delaying, mitigating, and preventing AD. While this preclinical state is an ideal target, it is difficult to identify efficiently and cost-effectively. Recent findings have suggested that cognitive-motor dual task paradigms may provide additional inference. OBJECTIVES: Investigate the relationship between dual task performance and amyloidosis, suggestive of preclinical Alzheimer's disease and whether dual task performance provides additional information beyond a cognitive composite, to help in the identification of amyloidosis. DESIGN: Cross-sectional. SETTING: Outpatient specialty brain health clinical research institution in the United States. PARTICIPANTS: 52 cognitively healthy adults. MEASUREMENTS: The data included demographics, amyloid standardized uptake value ratio obtained via florbetapir-PET, neuropsychological testing, apolipoprotien E genotype, and dual task performance measures. Data were analyzed via hierarchal multiple linear regression or logistic regression, controlling for age, education, and apolipoprotien E genotype. Receiver operating characteristic curves were plotted, and sensitivity and specificity calculated via 2x2 contingency tables. RESULTS: There was a moderate relationship (rs>.30) between motor and cognitive dual task effects and amyloid standardized uptake value ratio (ps<.042). A strong relationship (r=.58) was found between combined dual task effect, a measure of automaticity derived from dual task performance, and amyloid standardized uptake value ratio (p<.001). Additionally, combined dual task effect showed promise in its unique contributions to amyloid standardized uptake value ratio, accounting for 7.8% of amyloid standardized uptake value ratio variance beyond cognitive composite scores (p=.018). Additionally, when incorporated into the cognitive composite, combined dual task effect resulted in improved diagnostic accuracy for determining elevated amyloid standardized uptake value ratio, and increased the sensitivity and specificity of the cognitive composite. CONCLUSSION: Dual task performance using the combined dual task effect, a measure of automaticity, was a moderate predictor of cerebral amyloidosis, which suggests that it has utility in the screening and diagnosis of individuals for preclinical AD. Additionally, when combined with the cognitive composite, the combined dual task effect improves diagnostic accuracy. Further research is warranted.

The effect of climate variability in the efficacy of the entomopathogenic fungus Metarhizium acridum against the desert locust Schistocerca gregaria.

Despite substantial efforts to control locusts they remain periodically a major burden in Africa, causing severe yield loss and hence loss of food and income. Distribution maps indicating the value of the basic reproduction number R0 was used to identify areas where an insect pest can be controlled by a natural enemy. A dynamic process-based mathematical model integrating essential features of a natural enemy and its interaction with the pest is used to generate R0 risk maps for insect pest outbreaks, using desert locust and the entomopathogenic fungus Metarhizium acridum (Synn. Metarhizium anisoliae var. acridum) as a case study. This approach provides a tool for evaluating the impact of climatic variables such as temperature and relative humidity and mapping spatial variability on the efficacy of M. acridum as a biocontrol agent against desert locust invasion in Africa. Applications of M. acridum against desert locust in a few selected African countries including Morocco, Kenya, Mali, and Mauritania through monthly spatial projection of R0 maps for the prevailing climatic condition are illustrated. By combining mathematical modeling with a geographic information system in a spatiotemporal projection as we do in this study, the field implementation of microbial control against locust in an integrated pest management system may be improved. Finally, the practical utility of this model provides insights that may improve the timing of pesticide application in a selected area where efficacy is highly expected.

A comparison of structural features and vulnerability between government and nongovernment alcohol and other drug (AOD) treatment providers.

OBJECTIVE: Both public (government-run), and not-for-profit (nongovernment) service providers provide alcohol and other drug (AOD) treatment services. Research has rarely studied the structural features of these providers, such as workforce characteristics, procurement arrangements, and funding security. The study reported here sought to document and analyze the differences between these two AOD treatment provider types in Australia. METHODS: The study administered an online survey instrument targeted at managers of AOD treatment sites. The survey comprised three sections: (1) the service (e.g., treatment types); (2) workforce (e.g., total number of staff); and (3) funding and procurement arrangements (e.g., contract length). The study completed a total of 207 site surveys. The studied compared government and nongovernment services on structural features that may create a more or less sustainable or vulnerable service (funding arrangements, payment mechanisms, and contract length). RESULTS: Government providers were more likely to provide medically oriented treatment types such as withdrawal management and pharmacotherapy, whereas nongovernment organization (NGO) providers were more likely to offer rehabilitation. Consistent with this, government services were more likely to employ medical professionals and nurses, indicative of a more medically oriented workforce, while NGO services were more likely to employ AOD workers, youth workers, peer workers, and counselors. Our data illustrate that NGO services were more likely to be subject to competitive tendering and to have shorter contract lengths, compared with government services, and overall to be more structurally vulnerable. CONCLUSION: Despite the reliance on NGOs to provide the majority of specialist care (71% of all treatment episodes in Australia), these services are more vulnerable than their government counterparts. To ensure that a comprehensive suite of treatment services is available, procurement arrangements that support stability and security in nongovernment service providers and government service providers are essential.

Effect of Tribochemical Coating on Composite Repair Strength.

CLINICAL RELEVANCE: Tribochemical treatment of existing composite surfaces is highly effective for composite repair. When repairing an old composite restoration, the clinician should try to use the same composite originally used for the restoration. If the information about the original restoration is not known, a composite with strong mechanical properties should be used for the repair restoration. SUMMARY: This study evaluated the effect of tribochemical coating on composite-to-composite repair interfacial fracture toughness (iFT). Sixty beam-shaped specimens (21×4×3 ± 0.2 mm) were prepared with a nanofill composite (Filtek Supreme Ultra [FSU]) and a nanohybrid composite (Clearfil Majesty ES-2 [CME]) and aged for 50,000 thermocycles (5°C-55°C, 20-second dwell time) and then sectioned in half. The resulting 120 hemispecimens (60 for each composite) were randomly assigned to different repair methods (n=10): universal adhesive (Clearfil Universal Bond Quick [CUB]), sand-blasting followed by CUB, or tribochemical coating (CoJet, CoJet sand, Espe-Sil, and Visio-Bond). The repair surface was prepared with a diamond bur (Midwest #471271), rinsed, and dried. Each aged composite brand (FSU, CME) was repaired with either the same composite or the opposite composite. All adhesives and composites were light cured with a high-irradiance LED curing light (Elipar DeepCure-S). After postrepair storage in 100% humidity and at 37°C for 24 hours, iFT was measured as KIc (MPa m½). Data were analyzed for statistical significance using two-way analysis of variance (ANOVA) and the Tukey honest significant difference post hoc test (α=0.05). Regardless of the substrate composite, ANOVA showed significant differences for surface treatment (p<0.0001) and repair composite (p<0.0001). Mean iFT values (SD) ranged from 0.91 (0.10) MPa·m½ to 2.68 (0.12) MPa·m½. Repairs made with FSU after CoJet resulted in significantly higher iFT (FSU: 2.68 MPa·m½; CME: 2.21 MPa·m½) when compared to the other experimental groups. The repair iFT was higher with CoJet treatment and when the nanofill composite FSU was used as the repair composite.

Efficacy of oregano and rosemary essential oils to affect morphology and membrane functions of noncultivable sessile cells of Salmonella Enteritidis 86 in biofilms formed on stainless steel.

AIMS: This study evaluated the efficacy of essential oil from Origanum vulgare L. (oregano; OVEO) and Rosmarinus officinalis L. (rosemary; ROEO) to inactivate sessile cells of Salmonella enterica serovar Enteritidis 86 (SE86) in young and mature biofilms formed on stainless steel. METHODS AND RESULTS: Ultrastructural alterations and damage in different physiological functions caused by OVEO and ROEO in noncultivable sessile cells of SE86 were investigated using scanning electron microscopy and flow cytometry. OVEO (2·5 µl ml-1 ) and ROEO (40 µl ml-1 ) were effective to eradicate young and mature biofilms formed by SE86 sessile cells on stainless steel surfaces; however, the efficacy varied with exposure time. OVEO and ROEO caused alterations in morphology of SE86 sessile cells, inducing the occurrence of bubbles or spots on cell surface. OVEO and ROEO compromised membrane polarization, permeability and efflux activity in noncultivable SE86 sessile cells. These findings show that OVEO and ROEO act by a multitarget mechanism on SE86 membrane functions. CONCLUSIONS: ROEO and OVEO showed efficacy to eradicate SE86 sessile cells in preformed biofilms on stainless steel, displaying a time-dependent effect and multitarget action mode on bacterial cell membrane. SIGNIFICANCE AND IMPACT OF THE STUDY: The study provides for the first time the effects of OVEO and ROEO on morphology and physiological functions of noncultivable sessile cells of S. Enteritidis biofilms preformed on stainless steel surfaces.

Composite-composite Adhesion as a Function of Adhesive-composite Material and Surface Treatment.

OBJECTIVE: To evaluate the composite-to-composite repair interfacial fracture toughness (iFT) as a function of adhesive and composite repair material. METHODS AND MATERIALS: Beam-shaped composite specimens (21×4×3±0.2 mm) were prepared for each substrate material (Filtek Supreme Ultra [FSU] or Clearfil Majesty ES-2 [CME]) and artificially aged for 50,000 thermocycles (5-55°C, 20-second dwell time). Aged specimens were sectioned in half, and the resulting hemispecimens were randomly assigned to one of the different repair methods (n=10) based on the following variables: type of substrate composite (FSU or CME), acid etch (yes or no), adhesive type (Scotchbond Universal or Clearfil SE Bond 2), and type of repair composite (FSU or CME). The repair surface was prepared with a course diamond bur (Midwest #471271). When used, 37% phosphoric acid was applied for 20 seconds, rinsed, and dried. All adhesives and composites were applied according to manufacturers' instructions. After postrepair storage (100% humidity, 37°C, 24 hours), iFT was measured and expressed as MPa. Data were analyzed for statistical significance using a three-way analysis of variance and Tukey post hoc tests (α=0.05). RESULTS: iFT values ranged from 0.64 ± 0.19 MPa to 1.28 ± 013 MPa. Significantly higher iFT values were achieved when FSU was used as the repair composite resin regardless of the substrate composite resin (p<0.001). Clearfil SE Bond 2 adhesive was associated with significantly higher iFT values for FSU substrate (p<0.001). The etching procedure had no significant effect on the iFT values of the repair procedures (p>0.05). CONCLUSIONS: Composite repair strength is adhesive and composite dependent. Repair strength appears to be higher when FSU is the repair composite regardless of the adhesive used.

Bio-inspired Model of Humanoid Robot for Ascending Movement.

Stair climbing is one of the important daily life activities that biped robots have to carry out. However, the number of researches study the ascending movement mechanisms and its stability is low. In this study, we have inspired by human ascending movement underlying mechanisms and developed a new control law based on the nature of the human motor behavior. This model has been developed in phase space using an intermittent sliding mode controller to give stable control and eliminate the effect of the system's uncertainty. A planar five-link biped model has been used to test the model. The embedded space and controller has been formed for each joint separately. Therefore, in this case, the position of each angle in embedded space gets compared along time with its corresponding desired dynamic. The position of each angle in space regarding its corresponding reference trajectory made the error signal. Results show that the designed sliding mode controllers successfully keeps the trajectory near the desired dynamics, and the output follows the desired dynamic very well.

Geographic variation in surgical practice patterns and outcomes for resected nonmetastatic gastric cancer in Ontario.

Background: Gastrectomy with negative resection margins and adequate lymph node dissection is the cornerstone of curative treatment for gastric cancer (gc). However, gastrectomy is a complex and invasive operation with significant morbidity and mortality. Little is known about surgical practice patterns or short- and long-term outcomes in early-stage gc in Canada. Methods: We undertook a population-based retrospective cohort study of patients with gc diagnosed between 1 April 2005 and 31 March 2008. Chart review provided clinical and operative details such as disease stage, primary tumour location, surgical approach, operation, lymph nodes, and resection margins. Administrative data provided patient demographics, geography, and vital status. Variations in treatment and outcomes were compared for 14 local health integration networks. Descriptive statistics and log-rank tests were used to examine geographic variation. Results: We identified 722 patients with nonmetastatic resected gc. We documented significant provincial variation in case mix, including primary tumour location, stage at diagnosis, and tumour grade. Short-term surgical outcomes varied across the province. The percentage of patients with 15 or fewer lymph nodes removed and examined varied from 41.8% to 73.8% (p = 0.02), and the rate of positive surgical margins ranged from 15.2% to 50.0% (p = 0.002). The 30-day surgical mortality rates did not vary statistically significantly across the province (p = 0.13); however, rates ranged from 0% to 16.7%. Overall 5-year survival was 44% and ranged from 31% to 55% across the province. Conclusions: This cohort of patients with resected stages i-iii gc is the largest analyzed in Canada, providing important historical information about treatment outcomes. Understanding the causes of regional variation will support interventions aiming to improve gc operative outcomes in the cancer system.

Deficient primary cilia in obese adipose-derived mesenchymal stem cells: obesity, a secondary ciliopathy?

Obesity alters the composition, structure and function of adipose tissue, characterized by chronic inflammation, insulin resistance and metabolic dysfunction. Adipose-derived mesenchymal stem cells (ASCs) are responsible for cell renewal, spontaneous repair and immunomodulation in adipose tissue. Increasing evidence highlights that ASCs are deficient in obesity, and the underlying mechanisms are not well understood. We have recently shown that obese ASCs have defective primary cilia, which are shortened and unable to properly respond to stimuli. Impaired cilia compromise ASC functions. This work suggests an intertwined connection of obesity, defective cilia and dysfunctional ASCs. We have here discussed the current data regarding defective cilia in various cell types in obesity. Based on these observations, we hypothesize that obesity, a systemic chronic metainflammation, could impair cilia in diverse ciliated cells, like pancreatic islet cells, stem cells and hypothalamic neurons, making these critical cells dysfunctional by shutting down their signal sensors and transducers. In this context, obesity may represent a secondary form of ciliopathy induced by obesity-related inflammation and metabolic dysfunction. Reactivation of ciliated cells might be an alternative strategy to combat obesity and its associated diseases.

Insight into the development of obesity: functional alterations of adipose-derived mesenchymal stem cells.

Obesity is associated with a variety of disorders including cardiovascular diseases, diabetes mellitus and cancer. Obesity changes the composition and structure of adipose tissue, linked to pro-inflammatory environment, endocrine/metabolic dysfunction, insulin resistance and oxidative stress. Adipose-derived mesenchymal stem cells (ASCs) have multiple functions like cell renewal, spontaneous repair and homeostasis in adipose tissue. In this review article, we have summarized the recent data highlighting that ASCs in obesity are defective in various functionalities and properties including differentiation, angiogenesis, motility, multipotent state, metabolism and immunomodulation. Inflammatory milieu, hypoxia and abnormal metabolites in obese tissue are crucial for impairing the functions of ASCs. Further work is required to explore the precise molecular mechanisms underlying its alterations and impairments. Based on these data, we suggest that deregulated ASCs, possibly also other mesenchymal stem cells, are important in promoting the development of obesity. Restoration of ASCs/mesenchymal stem cells might be an additional strategy to combat obesity and its associated diseases.

Reevaluation of established and new criteria in differential diagnosis of Spitz nevus and melanoma.

The histopathologic differentiation between Spitz nevus and melanoma is of particular interest in routine diagnostic procedures of melanocytic tumors. Atypical Spitz nevi are sometimes difficult to distinguish from melanoma. There is still no single criterion that ensures a distinction of melanoma and atypical Spitz nevus. The aim of this study was to reevaluate established and new criteria to differentiate Spitz nevus from melanoma more reliably. We analyzed 25 melanomas with a Breslow index ≥ 1 mm and 18 classical compound Spitz nevi concerning their histopathologic, immunohistochemical and molecular genetic characteristics. Moreover, clinical follow-up data for 5 years were collected. We found statistically significant differences between Spitz nevus and melanoma for the following features: pagetoid spread, atypia, maturation, elastosis, Kamino bodies, p16 expression, and the staining pattern of HMB45. BRAF was positive in 7/21 melanomas and in 1/14 Spitz nevi. Fluorescence in situ hybridization confirmed the histopathologic diagnosis in 36/37 cases. The established clinical, histopathologic, and immunohistochemical criteria to differentiate Spitz nevus and melanoma could be reproduced in our collective. Especially, the expression of p16, BRAF analysis and fluorescence in situ hybridization proved to be helpful tools to improve the differentiation of Spitz nevus and melanoma in our study. Nevertheless, there is-until now-no reliable histopathologic and immunohistochemical parameter which can discriminate Spitz nevus and melanoma with absolute certainty.

Effects of Colloidal Crystals, Antibiotics, and Surface-Bound Antimicrobials on Pseudomonas aeruginosa Surface Density.

We examined the effect of a crystalline layer of silica particles in the size range 0.5-4 µm on the adsorption and surface growth of Pseudomonas aeruginosa. Growth on these colloidal crystal monolayers (CCMs) was compared to growth on a flat plate of silica. All surfaces were coated with a thin film of silica to provide chemical uniformity of the different topographies. The results showed that the CCM reduces the density of colony forming units (CFU) on the solid by 99-99.9% when the suspension load was 103 CFU. We also examined the interaction between the CCM and either antibiotics or a chemically bound antimicrobial. The addition of 20 µg/mL tobramycin after an initial 24 h growth period caused a further decrease in CFU counts of about 99-99.9% for all topographies. The percentage reduction as a result of the antibiotics was similar for all topographies, which suggested that there was no particular synergy between the topography and antibiotics. On the other hand, the additive nature of the two effects suggested promise for clinical studies: the large percentage reduction in CFU density on addition of the antibiotic to a flat surface was maintained on the topography, even starting from a much lower CFU density. A similar result was obtained for the combination of CCM and a covalently bound layer of antimicrobial poly(allylamine hydrochloride) (PAH). The PAH reduced the CFU, and the CCM caused a further reduction; the two factors behaved approximately independently. Overall the CCM was found to be very effective at reducing the density of adsorbed P. aeruginosa both with and without the additional reductions caused by antibiotics or surface-bound antimicrobials.

The productive techniques and constitutive effects of 'evidence-based policy' and 'consumer participation' discourses in health policy processes.

For over twenty years there have been calls for greater 'consumer' participation in health decision-making. While it is recognised by governments and other stakeholders that 'consumer' participation is desirable, barriers to meaningful involvement nonetheless remain. It has been suggested that the reifying of 'evidence-based policy' may be limiting opportunities for participation, through the way this discourse legitimates particular voices to the exclusion of others. Others have suggested that assumptions underpinning the very notion of the 'affected community' or 'consumers' as fixed and bounded 'policy publics' need to be problematised. In this paper, drawing on interviews (n = 41) with individuals closely involved in Australian drug policy discussions, we critically interrogate the productive techniques and constitutive effects of 'evidence-based policy' and 'consumer participation' discourses in the context of drug policy processes. To inform our analysis, we draw on and combine a number of critical perspectives including Foucault's concept of subjugated knowledges, the work of feminist theorists, as well as recent work regarding conceptualisations of emergent policy publics. First, we explore how the subject position of 'consumer' might be seen as enacted in the material-discursive practices of 'evidence-based policy' and 'consumer participation' in drug policy processes. Secondly, we consider the centralising power-effects of the dominant 'evidence-based policy' paradigm, and how resistance may be thought about in this context. We suggest that such interrogation has potential to recast the call for 'consumer' participation in health policy decision-making and drug policy processes.

Deficiency of RITA results in multiple mitotic defects by affecting microtubule dynamics.

Deregulation of mitotic microtubule (MT) dynamics results in defective spindle assembly and chromosome missegregation, leading further to chromosome instability, a hallmark of tumor cells. RBP-J interacting and tubulin-associated protein (RITA) has been identified as a negative regulator of the Notch signaling pathway. Intriguingly, deregulated RITA is involved in primary hepatocellular carcinoma and other malignant entities. We were interested in the potential molecular mechanisms behind its involvement. We show here that RITA binds to tubulin and localizes to various mitotic MT structures. RITA coats MTs and affects their structures in vitro as well as in vivo. Tumor cell lines deficient of RITA display increased acetylated α-tubulin, enhanced MT stability and reduced MT dynamics, accompanied by multiple mitotic defects, including chromosome misalignment and segregation errors. Re-expression of wild-type RITA, but not RITA Δtub ineffectively binding to tubulin, restores the phenotypes, suggesting that the role of RITA in MT modulation is mediated via its interaction with tubulin. Mechanistically, RITA interacts with tubulin/histone deacetylase 6 (HDAC6) and its suppression decreases the binding of the deacetylase HDAC6 to tubulin/MTs. Furthermore, the mitotic defects and increased MT stability are also observed in RITA-/- mouse embryonic fibroblasts. RITA has thus a novel role in modulating MT dynamics and its deregulation results in erroneous chromosome segregation, one of the major reasons for chromosome instability in tumor cells.

Experimental amine-epoxide sealer: a physicochemical study in comparison with AH Plus and EasySeal.

AIM: To compare selected physicochemical and biological properties of an experimental sealer with those of two commercially available sealers. METHODOLOGY: AH Plus and EasySeal were used as model materials for commercially available amine-epoxide sealers. They were mixed as stated by the manufacturer. The two components of experimental sealer EvoSeal A were mixed 1 : 1 vol%. The setting time was determined in two different ways: first, by setting of sealers in a temperature- and moisture-controlled environment followed by testing with a Gilmore needle and secondly, by oscillating measurements of setting behaviour using a rheometer. Differential scanning calorimetry (DSC) of the sealer was performed for comparison of thermal properties. Flow and film thickness were determined by applying pressures of 100 g and 15.3 kg, respectively, on the materials between two glass plates and measuring the diameters of the compressed sealer and the thickness with a micrometer gauge. Solubility of set materials was conducted by layering the samples with water, storing in a temperature- and humidity-controlled environment and evaporating the solvent. The solved sealer parts were then weighed. The radiopacity was measured in an X-ray experiment comparing radiopacity of a cured sealer to an aluminium step wedge. Volume shrinkage was defined by measuring the densities of samples before and after setting. The film thickness, fluidity, curing time, radiopacity and solubility of the test materials were performed as specified in DIN EN ISO 6876:2010 draft. The volume shrinkage was determined in a method adapted from standard DIN 13907:2007-01. Antibacterial activity was tested against Gram-positive Streptococcus oralis cultures in a contact test based on standard ISO 22196:2011 (E). Statistical analysis was performed using Mann-Whitney U-test where applicable. Significant differences were determined with P < 0.05. RESULTS: The experimental sealer, EvoSeal A, reached standard specifications. In terms of film thickness, the highest value was measured for EvoSeal A with a film thickness of 27 µm, comparing to 6 µm for EasySeal (P ≤ 0.001) and 8 µm for AH Plus (P ≤ 0.001). Comparing the flow, all values corresponded to EasySeal with a diameter of 17.3 mm. The only significant difference was determined for AH Plus compared to EvoSeal A (P = 0.0353). Volume shrinkage of EvoSeal A was 48% smaller compared to EasySeal and approximately 20% lower compared to AH Plus. The shortest curing time was determined for EvoSeal A (3.0 h) followed by EasySeal (4.1 h) and AH Plus (24 h). For all groups, significant differences were observed (P ≤ 0.001). EvoSeal A had a significantly higher radiopacity than EasySeal (P ≤ 0.001) but significantly lower values than AH Plus (P ≤ 0.001). The solubility of AH Plus and EvoSeal A was <0.5% (P = 0.2435). Compared to EasySeal with a solubility of 2.7%, significant differences were observed (P ≤ 0.02). Three weeks after setting, EasySeal and EvoSeal A still had an antibacterial effect against S. oralis in contrast to AH Plus. In this respect, comparing AH Plus with EvoSeal A and EasySeal, respectively, significant differences were observed (P ≤ 0.001). No significant differences between EasySeal with EvoSeal A (P = 0.540) were determined. CONCLUSIONS: The physical and chemical properties of the experimental sealer EvoSeal A were comparable to the two commercially established sealers EasySeal and AH Plus.