Evaluation of Smear Layer Removal Using Different Irrigation Methods In Root Canals

This study evaluated different irrigation methods in smear layer removal from the root canal walls using maleic acid (MA). Maxillary anterior teeth (N=30, n=10 per group) were decoronated, canals were enlarged with Protaper (size F4) and allocated to three groups: EndoUltra: 2.5 ml of 7% MA was irrigated for 30 s, followed by EndoUltra activation for 30 s; EndoSafe: EndoSafe irrigation system was used for 1 minute using 5 ml of 7% MA; Side-vented needle: 30 gauge needle irrigation was performed for 1 min using 5 ml of 7% MA. After SEM analysis, the inter-examiner reliability was verified using Kendall's Co-efficient and data were analyzed using Pearson Chi-Square test. No statistical significant differences were found between the two examiners (p⟩0.05). In intra-group comparison, needle and EndoSafe irrigation demonstrated significantly better smear layer removal at middle third of the root canal system (p⟨0.05) when compared to apical third. In inter-group comparison, smear layer was minimally removed with needle irrigation. In the apical third, EndoUltra group removed smear layer more effectively. Endosafe needle irrigation in combination with 7% MA removed the smear layer in the root canal at best, while the EndoUltra performed the best at the apical third of the root.

Pathogenesis and tissue tropism of Newcastle disease virus and avian influenza virus (H9N2) in single and mixed infections

Newcastle disease (ND) and avian influenza (AI) are globally considered as a serious threat to the chicken and other avian species. The paramyxovirus type 1 and orthomyxovirus type A are RNA viruses, which cause ND and AI infection, respectively.

Abstract P2-02-17: Metabolism-driven cancer identification with GLUT5-specific molecular probes

Background: Current cancer imaging agents are limited in their ability to distinguish cancers from normal cells (low cancer-selectivity) and identify cancers at different stages of development (low cancer-specificity). This limitation makes biopsy mandatory for diagnosis and continuous treatment monitoring. Analysis of biopsy samples may also have some ambiguity in clearly identifying malignant and metastatic cells, resulting in cases of mischaracterization and overdiagnosis. Hence, cancer-selective and cancer-specific imaging agents are needed. Distinguishing cancer types and stages can be achieved by addressing differences in their nutrient uptake, manifested as changes in the expression of facilitative sugar transporters (GLUTs). Here, we present a novel approach to target the enhanced metabolism in breast cancers with sugar-like fluorescently labeled probes – ManCous - engineered for specific uptake by fructose transporter GLUT5. The differential accumulation of these probes in cancer cells parallels the differential activity of GLUT5 and results in active fluorescence accumulation within cancers with the highest levels observed in premalignant phenotypes.

Results: Locking fructose conformation in the furanose form was found to provide a sugar-like mimics recognized explicitly by GLUT5. The corresponding coumarin conjugates – ManCous (Figure 1A) - were found to exhibit GLUT5-specific uptake and work as reporters of GLUT5 activity in cells. Differential activity of GLUT5 in cells was found to parallel the differences in the uptake of ManCous. Significant differences in accumulation of ManCou-induced fluorescence were observed between normal and cancer cells and between cancer phenotypes (Figure 1A). Namely, an 8-fold difference in ManCou accumulation was observed between normal and adenocarcinoma MCF7 cells, and 70-fold difference was observed between normal and premalignant MCF10aNeoT cells. The uptaken ManCou were found to be metabolized by hexokinase to form phosphorylated analogs and effectively compete with glucose for hexokinase II (Figure 1B). The probes were found to be non-cytotoxic at concentrations below 100 μM, with higher cytotoxicity towards cancer cells at probe concentrations above 100 μM

Conclusions: The dependence of breast cancer cells on fructose provides a firm basis for developing imaging approaches to discriminate between normal and cancer cells as well as potentially between cancer phenotypes. While current probes are restricted to in-vitro imaging, further probe evolution is expected to lead to new in vivo agents, owing to a proper modification of the scaffold with the relevant radioactive (PET) or other imaging entity and retention of transporter specificity. The development of transporter-specific GLUT5 affinity probes could further contribute to enhancing the impact of fructose uptake inhibition for approaching cancer-specific therapies.

Citation Format: Ghosh A, Kannan S, Begoyan VV, Weselinski LJ, Rao S, Tanasova M. Metabolism-driven cancer identification with GLUT5-specific molecular probes [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P2-02-17.

Tumor suppressor Interferon Regulatory Factor 1 selectively blocks expression of endogenous retrovirus

Endogenous retroviruses (ERVs) comprise 10% of the genome, with many of these transcriptionally silenced post early embryogenesis. Several stimuli, including exogenous virus infection and cellular transformation can reactivate ERV expression via a poorly understood mechanism. We identified Interferon Regulatory Factor 1 (IRF-1), a tumor suppressor and an antiviral host factor, as a suppressor of ERV expression. IRF-1 decreased expression of a specific mouse ERV in vitro and in vivo. IRF-3, but not IRF-7, also decreased expression of distinct ERV families, suggesting that suppression of ERVs is a relevant biological function of the IRF family. Given the emerging appreciation of the physiological relevance of ERV expression in cancer, IRF-1-mediated suppression of specific ERVs may contribute to the overall tumor suppressor activity of this host factor.

A quantitative analysis of the performance of computing architectures used in neural simulations

BACKGROUND

Numerical solutions of neuron models are helping neuroscientists gain new insights into the behavior of neural systems. Although computing power is increasing, the complexity of the systems being simulated is also increasing. If the computation is not well matched to the computing hardware, simulations can take lengthy times to run, which can make it more difficult to draw inferences from those simulations and also to use them in feedback with living neurons such as in the dynamic clamp.

NEW METHOD

In this paper, we perform a quantitative analysis to get a better sense of how much impact the hardware architectures can have on simulation performance. Three different architectures are implemented on the same hardware platform and compared with respect to simulation time, error, and resources used.

RESULTS

The results indicate that a lookup table approach to evaluate functions can decrease simulation time by orders of magnitude with respect to the traditional approach of mathematical operations.

COMPARISON WITH EXISTING METHOD(S)

There are many different ways to implement a lookup table approach to evaluate a function. The method presented in this paper sacrifices some speed for greater generality and accuracy with respect to other published methods.

CONCLUSIONS

Lookup tables with 32 interpolation points can dramatically speed up computation time of neural simulations without adding significant error. In this paper linear interpolation was used, but higher order interpolation could be used to further reduce simulation time.

Effect of probiotics on C-reactive protein levels in preterm infants: Secondary analysis of a randomized controlled trial

BACKGROUND

Excessive inflammation is associated with adverse outcomes in preterm infants. C- reactive protein (CRP) is a marker of inflammation/infection. Probiotics have anti-inflammatory properties. Randomized controlled trials (RCTs) in preterm infants have not reported effect of probiotics on CRP.

AIM

To evaluate effect of probiotics on CRP in preterm infants who had participated in a RCT of Bifidobacterium breve (B. breve) m-16v.

METHODS

Data on all infants (GA <33 weeks, n = 159) enrolled in the RCT was analyzed. For study purpose, CRP <15 mg/L and ≤10 mg/L was considered normal for the first week, and thereafter respectively. Mixed logistic regression modelling was used to assess probiotic effect on CRP levels.

RESULTS

There were 1579 CRP measurements (Probiotic: 851 vs. Placebo: 728). Baseline characteristics and number [Median (IQR)] of CRP estimations per infant [l0 (5, 20) vs. 10 (6, 17), p = 0.861] were comparable between probiotic vs. placebo group. There was no significant difference in the proportion of infants with high CRP over time (treatment by weekly time points interaction, p = 0.187), and across all time points between probiotic and placebo group (adjusted OR: 1.62, 95% CI: 0.91-2.88, p = 0.102)CONCLUSION:B. breve m-16v did not decrease CRP levels in preterm infants born <33 weeks.