scholarly journals In Vitro Methods to Decipher the Structure of Viral RNA Genomes

2021 ◽  
Vol 14 (11) ◽  
pp. 1192
Author(s):  
Cristina Romero-López ◽  
Sara Esther Ramos-Lorente ◽  
Alfredo Berzal-Herranz

RNA viruses encode essential information in their genomes as conserved structural elements that are involved in efficient viral protein synthesis, replication, and encapsidation. These elements can also establish complex networks of RNA-RNA interactions, the so-called RNA interactome, to shape the viral genome and control different events during intracellular infection. In recent years, targeting these conserved structural elements has become a promising strategy for the development of new antiviral tools due to their sequence and structural conservation. In this context, RNA-based specific therapeutic strategies, such as the use of siRNAs have been extensively pursued to target the genome of different viruses. Importantly, siRNA-mediated targeting is not a straightforward approach and its efficiency is highly dependent on the structure of the target region. Therefore, the knowledge of the viral structure is critical for the identification of potentially good target sites. Here, we describe detailed protocols used in our laboratory for the in vitro study of the structure of viral RNA genomes. These protocols include DMS (dimethylsulfate) probing, SHAPE (selective 2′-hydroxyl acylation analyzed by primer extension) analysis, and HMX (2′-hydroxyl molecular interference). These methodologies involve the use of high-throughput analysis techniques that provide extensive information about the 3D folding of the RNA under study and the structural tuning derived from the interactome activity. They are therefore a good tool for the development of new RNA-based antiviral compounds.

Coatings ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 549 ◽  
Author(s):  
Bruna Sinjari ◽  
Gianmaria D’Addazio ◽  
Martina Bozzi ◽  
Manlio Santilli ◽  
Tonino Traini ◽  
...  

The aim of this in vitro study was to evaluate the enamel surface topography after treatment with three air polishing powders: Glycine (A), erythritol (B), and sodium bicarbonate (C) (Air Flow Soft, Plus and Classic powders, EMS Electro Medical Systems S.A., Nyon, Switzerland). Fifteen extracted incisors were randomly divided into three groups of five teeth each, A, B and C, respectively. The teeth were blocked in plaster bases, washed, dried and half-covered with polytetrafluoroethylene strips before treatment. In this way, each half-treated dental element became test and control of itself. Comparative statistical analysis of Rq (geometric average of the deviations occurring in roughness profile) was performed. The scanning electron microscope (SEM) analysis showed different degrees of surface roughness between the groups, decreasing after treatment. In addition, a statistically significant reduction p < 0.05 was present in group C (Rq mean non-treated 108.17 µm, 95% CI: 97.29–124.01 and Rq mean treated 86.78 µm, 95% CI: 80.63–93.70). A decrease in surface roughness post-treatment was not observed in group A and B. Therefore, it may be concluded that the air flow powders tested herein can be used on dental enamel to reduce the surface roughness due to function and the action of dental therapies.


Sensors ◽  
2021 ◽  
Vol 21 (22) ◽  
pp. 7490
Author(s):  
Nattapong Sirintawat ◽  
Tanyaporn Leelaratrungruang ◽  
Pongsakorn Poovarodom ◽  
Sirichai Kiattavorncharoen ◽  
Parinya Amornsettachai

This study aimed to investigate and compare the reliability and accuracy of tooth shade selection in the model using 30 milled crowns via five methods: (1) digital single-lens reflex (DSLR) camera with twin flash (TF) and polarized filter (DSLR + TF), (2) DSLR camera with a ring flash (RF) and polarized filter (DSLR + RF), (3) smartphone camera with light corrector and polarized filter (SMART), (4) intraoral scanner (IOS), and (5) spectrophotometer (SPEC). These methods were compared with the control group or manufacturer’s shade. The CIE Lab values (L, a, and b values) were obtained from five of the methods to indicate the color of the tooth. Adobe Photoshop was used to generate CIE Lab values from the digital photographs. The reliability was calculated from the intraclass correlation based on two repetitions. The accuracy was calculated from; (a) ΔE calculated by the formula comparing each method to the control group, (b) study and control groups were analyzed by using the Kruskal–Wallis test, and (c) the relationship between study and control groups were calculated using Spearman’s correlation. The reliability of the intraclass correlation of L, a, and b values obtained from the five methods showed satisfactory correlations ranging from 0.732–0.996, 0.887–0.994, and 0.884–0.999, respectively. The ΔE from all groups had statistically significant differences when compared to the border of clinical acceptance (ΔE = 6.8). The ΔE from DSLR + TF, DSLR + RF, SMART, and SPEC were higher than clinical acceptance (ΔE > 6.8), whereas the ΔE from IOS was 5.96 and all of the L, a, and b values were not statistically significantly different from the manufacturer’s shade (p < 0.01). The ΔE of the DSLR + RF group showed the least accuracy (ΔE = 19.98), whereas the ∆E of DSLR + TF, SMART, and SPEC showed similar accuracy ∆E (ΔE = 10.90, 10.57, and 11.57, respectively). The DSLR camera combined with a ring flash system and polarized filter provided the least accuracy. The intraoral scanner provided the highest accuracy. However, tooth shade selection deserves the combination of various techniques and a professional learning curve to establish the most accurate outcome.


2012 ◽  
Vol 13 (6) ◽  
pp. 830-833
Author(s):  
Romel Joseph

ABSTRACT Aim The aim of this in vitro study was to evaluate the apical seal obtained with four root canal sealers AH 26, Sealapex, Endoflas FS and AH Plus, with lateral condensation. Materials and methods Sixty root canals were prepared using the step-back technique. The specimens were divided into four experimental groups of 12 teeth and two control groups of 12 teeth. The experimental groups were obturated by laterally condensed gutta-percha with one of the tested sealers and control groups were obturated without any sealer. Methylene blue dye penetration with centrifuging method was used to evaluate the apical sealing ability. The quantitative apical leakage of each specimen was measured after 2 weeks. Results The results showed no significant differences between all groups except between AH Plus and Endoflas FS (<0.05). AH Plus showed significantly less leakage than Endoflas FS. Conclusion AH Plus showed the least leakage compared to AH 26, Sealapex and Endoflas FS. How to cite this article Joseph R, Singh S. Evaluation of Apical Sealing Ability of Four Different Sealers using Centrifuging Dye Penetration Method: An in vitro Study. J Contemp Dent Pract 2012;13(6):830-833.


2006 ◽  
Vol 17 (4) ◽  
pp. 290-295 ◽  
Author(s):  
Marcos Paulo Nagayassu ◽  
Luciana Keiko Shintome ◽  
Eduardo Shigueyuki Uemura ◽  
José Eduardo Junho de Araújo

The purpose of this in vitro study was to evaluate the effect of different surface treatments on the shear bond strength of a resin-based cement to porcelain. Sixty pairs of 50% aluminous porcelain discs were fabricated. In each pair, one disc measured 6 mm in diameter X 3 mm thickness (A) and the other measured 3 mm in diameter X 3mm thickness (B). The specimens were randomly assigned to 6 groups (n=10 pairs of discs), according to the surface treatment: etching with 10% hydrofluoric acid for 2 or 4min (G1 and G2); 50-µm particle aluminum oxide sandblasting for 5 s (G3); sandblasting followed by etching for 2 or 4min (G4 and G5) and control - no treatment (G6). A silane agent was applied to the treated surface of both discs of each pair. Bistite II DC dual-cure resin cement was applied and the B discs were bonded to their respective A discs. Specimens were stored in distilled water at 37ºC for 24 h and were tested in shear strength at a crosshead speed of 2 mm/min. Means in MPa were: G1: 14.21 ± 4.68; G2: 8.92 ± 3.02; G3: 10.04 ± 2.37; G4: 12.74 ± 5.15; G5: 10.99 ± 3.35; G6: 6.09 ± 1.84. Data were compared by one-way ANOVA and Tukey's test at 5% significance level. Bond strength recorded after 2-min acid etching was significantly higher than 4-min etching (p<0.05) and control (p<0.05), but did not differ significantlyfrom sandblasting alone (p>0.05) or followed by etching for 2 or 4 min (p>0.05). Within the limitations of an in vitro study, it may be concluded that 2-min hydrofluoric acid etching produced a favorable micromechanical retention that enhanced resin cement bond strength to porcelain.


2020 ◽  
Vol 14 (4) ◽  
pp. 244-249
Author(s):  
Amir Hossein Mirhashemi ◽  
Atefe Saffar Shahroudi ◽  
Keyvan Shahpoorzadeh ◽  
Niloofar Habibi Khameneh

Background. This study compared the force decay pattern of two different orthodontic active tiebacks (ATBs) exposed to five different commercially available mouth rinses. Methods. In this in vitro study, 90 transparent ATBs and 90 gray ATBs were divided into six groups; one was the control group, and the others were exposed to one of these mouth rinses twice a day for 60 seconds: Listerine, chlorhexidine, Orthokin, Persica, and fluoride. The initial force of each ATB was 250 g at a 24-mm extension. The force of ATBs was measured on days 1, 7, 14, and 28 using a digital gauge. Results. The highest percentage of force loss was observed between days 14 and 28 (P<0.05). At the end of the study, the Persica group exhibited the highest force degradation in both ATB types. In the transparent ATBs, it was followed by Orthokin, Listerine, fluoride, chlorhexidine, and control groups, respectively. In the gray ATBs, Orthokin, chlorhexidine, control, Listerine, and fluoride groups exhibited the highest force decay in descending order. In some groups, the differences between transparent and gray ATBs were significant. In the control group, the force of transparent ATB was significantly higher than gray ones on days 7 and 14 but not significantly after four weeks. Conclusion. ATBs’ force degradation could be exacerbated by the use of some mouth rinses. There were some differences between force relaxation patterns of transparent and gray ATBs. The data could be beneficial in choosing appropriate O-rings for making ATBs.


2021 ◽  
Vol 22 (18) ◽  
pp. 9986
Author(s):  
Giulia Brunello ◽  
Kathrin Becker ◽  
Luisa Scotti ◽  
Dieter Drescher ◽  
Jürgen Becker ◽  
...  

Several decontamination methods for removing biofilm from implant surfaces during surgical peri-implantitis treatment have been reported, including the intraoperative usage of chlorhexidine (CHX)-based antiseptics. There is a lack of information on possible adverse effects on bone healing. The study aimed to examine the impact of three CHX-based mouthwashes on osteoblast-like cells (SaOS-2) in vitro. Cells were cultured for three days in 96-well binding plates. Each well was randomly treated for either 30, 60 or 120 s with 0.05% CHX combined with 0.05% cetylpyridinium chloride (CPC), 0.1% CHX, 0.2% CHX or sterile saline (NaCl) as control. Cell viability, cytotoxicity and apoptosis were assessed at day 0, 3 and 6. Cell viability resulted in being higher in the control group at all time points. At day 0, the CHX 0.2 group showed significantly higher cytotoxicity values compared to CHX 0.1 (30 s), CHX + CPC (30 s, 60 s and 120 s) and control (60 s and 120 s), while no significant differences were identified between CHX + CPC and both CHX 0.1 and NaCl groups. All test mouthwashes were found to induce apoptosis to a lower extent compared to control. Results indicate that 0.2% CHX presented the highest cytotoxic effect. Therefore, its intraoperative use should be carefully considered.


2020 ◽  
Vol 21 (4) ◽  
pp. 1303 ◽  
Author(s):  
Stefan Bauersachs ◽  
Pascal Mermillod ◽  
Carmen Almiñana

Oviductal extracellular vesicles (oEVs) are emerging as key players in the gamete/embryo–oviduct interactions that contribute to successful pregnancy. Various positive effects of oEVs on gametes and early embryos have been found in vitro. To determine whether these effects are associated with changes of embryonic gene expression, the transcriptomes of embryos supplemented with bovine fresh (FeEVs) or frozen (FoEVs) oEVs during in vitro culture compared to controls without oEVs were analyzed by low-input RNA sequencing. Analysis of RNA-seq data revealed 221 differentially expressed genes (DEGs) between FoEV treatment and control, 67 DEGs for FeEV and FoEV treatments, and minor differences between FeEV treatment and control (28 DEGs). An integrative analysis of mRNAs and miRNAs contained in oEVs obtained in a previous study with embryonic mRNA alterations pointed to direct effects of oEV cargo on embryos (1) by increasing the concentration of delivered transcripts; (2) by translating delivered mRNAs to proteins that regulate embryonic gene expression; and (3) by oEV-derived miRNAs which downregulate embryonic mRNAs or modify gene expression in other ways. Our study provided the first high-throughput analysis of the embryonic transcriptome regulated by oEVs, increasing our knowledge on the impact of oEVs on the embryo and revealing the oEV RNA components that potentially regulate embryonic development.


2021 ◽  
pp. 1-9
Author(s):  
Camila A. Zamperini ◽  
Berdan Aydin ◽  
Herve Y. Sroussi ◽  
Ana Karina Bedran-Russo

The role of the host immune system in caries progression is mainly speculative, and it is believed that it entails the enzymatic degradation of the dentin organic matrix. The aim of this study was to evaluate the proteolytic effect of human neutrophil enzymes on root caries progression. For this, specimens of bovine root dentin were divided into 4 groups (<i>n</i> = 30): caries (C), caries + neutrophils (C + N), no caries (Control), and no caries + neutrophils (Control + N). <i>Streptococcus mutans</i> biofilm (10<sup>5</sup> CFU/mL) was grown on the root surface to artificially induce root carious lesions (C and C + N groups). Specimens were then exposed to neutrophils (5 × 10<sup>6</sup> cells/mL) for 48 h (C + N and Control + N groups). Caries development and neutrophil exposures were repeated a 2nd and 3rd time. Caries depth (CD) and dentin demineralization (DD) were assessed by infiltration of rhodamine B using fluorescence microscopy. Collagen fibril ultrastructure was characterized under a polarized microscope with Picrosirius red staining. There were no significant differences (<i>p</i> &#x3e; 0.05) in CD and DD between the C and C + N groups for 1, 2, and 3 caries-neutrophil exposures. Immature collagen was significantly less present in the carious groups (C, <i>p</i> = 0.003; C + N, <i>p</i> = 0.01) than in the noncarious groups in the most superficial 200 µm. We thus concluded that human neutrophil enzymes did not influence short-term root caries progression, and immature collagen fibrils were more susceptible to degradation during <i>S. mutans</i>-induced root caries progression.


Medicina ◽  
2021 ◽  
Vol 57 (1) ◽  
pp. 45
Author(s):  
Yeojung Kim ◽  
Sangwon Yun ◽  
Keun-A Shin ◽  
Woosuk Chung ◽  
Youngkwon Ko ◽  
...  

Background and objectives: There are several studies that sevoflurane could enhance proliferation of cancer cells, while others suggest no effect on clinical outcome. We conducted in vivo and in vitro experiments to investigate the effects of sevoflurane, a volatile anesthetic, on proliferation and outcomes of Lewis lung carcinoma (LLC) cells. Materials and Methods: A total of 37 mice were injected with LLC cells to compare the tumor size and survival of the sevoflurane exposed group (sevo group) and control group. The sevo group was exposed to 2% sevoflurane and 4 L/min of oxygen for 1 h per day 3 times per week, and the control group was exposed only to 4 L/min of oxygen. In vitro study, 12 plates incubated with LCC cells. 6 plates were exposed to 2% sevoflurane for 1 hr/day for 3 days and 6 plates were not exposed, and cell proliferation was compared after 3 days. Results: There were no significant differences in survival or tumor size between mice exposed to sevoflurane and control mice (survival: 29.06 ± 4.45 vs. 28.76 ± 3.75, p = 0.836; tumor size: 0.75 (0.41–1.02) vs. 0.49 (0.11–0.79), p = 0.153). However, in vitro study, the proliferation of LLC cells exposed to sevoflurane increased by 9.2% compared to the control group (p = 0.018). Conclusions: Sevoflurane (2 vol%) exposure could promote proliferation of LLC cells in vitro environment, but may not affect proliferation of LLC cells in vivo environment. These results suggest that in vitro studies on the effects of anesthetics on cancer may differ from those of in vivo or clinical studies.


2010 ◽  
Vol 1 (3) ◽  
pp. 163-166
Author(s):  
Shelly Ahuja

ABSTRACT Introduction The major cellular events in the tissue repair are mitogenesis, migration and metabolism. The proteins responsible for coordination of these events are called “growth factors”. The activated platelets at the wound margins release several growth factors, such as PDGF, TGF-β and EGF, etc., and plasma exudates also provide an important source of TGF-β factors. Materials and methods Periodontal ligament fibroblast obtained from third molar impaction surgery, periodontal ligaments were cultured under standard conditions and spread on 96 well tissue culture plates. Platelet concentrate was obtained after centrifugation of 350-400 ml of blood at 1000 and 5000 rpm. 15 μl of platelet concentrate was added to each well. The proliferation rate of test and control group was determined by Redox indicator (Alamar blue® assay). The number of cells were counted by neu bar counting chamber after 24, 48 and 72 hours. Results The proliferation activity of cells was considerably higher in the platelet concentrate group (test group) than the control group. The difference was highly significant upto 72 hours after addition of platelet concentrates (Mann-Whitney U test p < 0.001). Conclusion A cellular effect of the platelet concentrate is clearly discernible. It was concluded that the use of platelet concentrate is an effective modality of regeneration.


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