Apical Tissues Research Articles

Multi-component resistance responses of melon to zucchini yellow mosaic virus.

A major resistance gene of the melon accession PI414723 to zucchini yellow mosaic virus (ZYMV) is located at the Zym-1 locus on chromosome 2, but the underlying defense mechanisms are poorly understood. The physiological responses and expression of selected genes at Zym-1 were assessed in PI414723 and in the susceptible genotype Védrantais. Viral titers and the expression of genes related to systemic acquired resistance (SAR) were evaluated in inoculated (Inoc) and non-inoculated (Non-Inoc) portions of the cotyledons at 3, 7 and 10 days after inoculation (dai) and in apical leaves at 10 dai. ZYMV was detected in both portions of the cotyledons but not in the apical leaves of PI414723 plants. Also, ZYMV was recovered in a susceptible zucchini only from Inoc portions at 3 dai. By contrast, in Védrantais ZYMV was detected and recovered from all tissues at high concentrations. Starchy local lesions and accumulation of transcripts of the SAR marker genes PR1 and PR4 were also detected in the resistant genotype. Plus, transcripts of one candidate resistance gene analog previously located at Zym-1 and of two melon homologs of restricted tobacco etch virus movement 2 (RTM2) genes located close to Zym-1, accumulated only in PI414723. It is proposed that resistance results from the combined action of the R gene, involved in restricting ZYMV replication after a supposed recognition event and of the RTM genes which impact viral systemic movement to distal apical tissues.

Positive contribution of shoot apex to the growth and flooding tolerance of Hemarthria altissima upon complete submergence

ABSTRACT Flooding events tend to destroy the original flood-intolerant vegetation in riparian zones, but the flood-tolerant species can confront the stress, and contribute to the riparian ecosystem. Grass species, Hemarthria altissima, are usually dominant in the riparian zones. This species is considered as good forage which is usually grazed by livestock or mowed by local people. Therefore, the apical tissues of the plants are often removed, and the plants have to grow without stem apexes, during their life cycle. In this study, we aimed to examine the differences in growth performance of intact versus apex-cut individuals of H. altissima upon complete submergence. Two groups of H. altissima plants (with and without shoot apexes) were treated with dark non-submergence and dark complete submergence conditions for 200 days. During the experiment, we measured plant growth, biomass changes in plant organs, and the consumption of non-structural carbohydrates (NSC) by different tissues. During submergence, shoot elongation stopped, and around six lateral buds were developed averagely by each plant without apexes. This growth performance finally caused 60% decline of NSC in underground parts. The relatively intensive consumption of carbohydrates in submerged apex-removed plants induced the 21% stem length decreased under water, which indicated the decreasing submergence tolerance of plants with shoot apex removed. Therefore, we suggest that when using H. altissima for restoring degraded riparian ecosystems, the shoot apexes should be protected from grazing by livestock or harvesting by local people in order to maintain the submergence tolerance of H. altissima.

Algorithm for Locating Apical Meristematic Tissue of Weeds Based on YOLO Instance Segmentation

Laser technology can be used to control weeds by irradiating the apical meristematic tissue (AMT) of weeds when they are still seedlings. Two factors are necessary for the successful large-scale implementation of this technique: the ability to accurately identify the apical meristematic tissue and the effectiveness of the localization algorithm used in the process. Based on this, this study proposes a lightweight weed AMT localization algorithm based on YOLO (look only once) instance segmentation. The YOLOv8n-seg network undergoes a lightweight design enhancement by integrating the FasterNet lightweight network as its backbone, resulting in the F-YOLOv8n-seg model. This modification effectively reduces the number of parameters and computational demands during the convolution process, thereby achieving a more efficient model. Subsequently, F-YOLOv8n-seg is combined with the connected domain analysis algorithm (CDA), yielding the F-YOLOv8n-seg-CDA model. This integration enables the precise localization of the AMT of weeds by calculating the center-of-mass coordinates of the connected domains. The experimental results indicate that the optimized model significantly outperforms the original model; the optimized model reduces floating-point computations by 26.7% and the model size by 38.2%. In particular, the floating-point calculation is decreased to 8.9 GFLOPs, and the model size is lowered to 4.2 MB. Comparing this improved model against YOLOv5s-seg and YOLOv10n-seg, it is lighter. Furthermore, it exhibits exceptional segmentation accuracy, with a 97.2% accuracy rate. Experimental tests conducted on five different weed species demonstrated that F-YOLOv8n-seg-CDA exhibits strong generalization capabilities. The combined accuracy of the algorithm for detecting these weeds was 81%. Notably, dicotyledonous weeds were detected with up to 94%. Additionally, the algorithm achieved an average inference speed of 82.9 frames per second. These results indicate that the algorithm is suitable for the real-time detection of apical meristematic tissues across multiple weed species. Furthermore, the experimental results demonstrated the impact of distinctive variations in weed morphology on identifying the location of the AMT of weeds. It was discovered that dicotyledonous and monocotyledonous weeds differed significantly in terms of the detection effect, with dicotyledonous weeds having significantly higher detection accuracy than monocotyledonous weeds. This discovery can offer novel insights and avenues for future investigation into the identification and location of the AMT of weeds.

Uncovering PheCLE1 and PheCLE10 Promoting Root Development Based on Genome-Wide Analysis.

Moso bamboo (Phyllostachys edulis), renowned for its rapid growth, is attributed to the dynamic changes in its apical meristem. The CLAVATA3/EMBRYO SURROUNDING REGION-RELATED (CLE) family genes are known to play crucial roles in regulating meristem and organ formation in model plants, but their functions in Moso bamboo remain unclear. Here, we conducted a genome-wide identification of the CLE gene family of Moso bamboo and investigated their gene structure, chromosomal localization, evolutionary relationships, and expression patterns. A total of 11 PheCLE genes were identified, all of which contained a conserved CLE peptide core functional motif (Motif 1) at their C-termini. Based on Arabidopsis classification criteria, these genes were predominantly distributed in Groups A-C. Collinearity analysis unveiled significant synteny among CLE genes in Moso bamboo, rice, and maize, implying potential functional conservation during monocot evolution. Transcriptomic analysis showed significant expression of these genes in the apical tissues of Moso bamboo, including root tips, shoot tips, rhizome buds, and flower buds. Particularly, single-cell transcriptomic data and in situ hybridization further corroborated the heightened expression of PheCLE1 and PheCLE10 in the apical tissue of basal roots. Additionally, the overexpression of PheCLE1 and PheCLE10 in rice markedly promoted root growth. PheCLE1 and PheCLE10 were both located on the cell membrane. Furthermore, the upstream transcription factors NAC9 and NAC6 exhibited binding affinity toward the promoters of PheCLE1 and PheCLE10, thereby facilitating their transcriptional activation. In summary, this study not only systematically identified the CLE gene family in Moso bamboo for the first time but also emphasized their central roles in apical tissue development. This provides a valuable theoretical foundation for the further exploration of functional peptides and their signaling regulatory networks in bamboo species.

Genome-wide transcript expression analysis reveals major chickpea and lentil genes associated with plant branching.

The search for elite cultivars with better architecture has been a demand by farmers of the chickpea and lentil crops, which aims to systematize their mechanized planting and harvesting on a large scale. Therefore, the identification of genes associated with the regulation of the branching and architecture of these plants has currently gained great importance. Herein, this work aimed to gain insight into transcriptomic changes of two contrasting chickpea and lentil cultivars in terms of branching pattern (little versus highly branched cultivars). In addition, we aimed to identify candidate genes involved in the regulation of shoot branching that could be used as future targets for molecular breeding. The axillary and apical buds of chickpea cultivars Blanco lechoso and FLIP07-318C, and lentil cultivars Castellana and Campisi, considered as little and highly branched, respectively, were harvested. A total of 1,624 and 2,512 transcripts were identified as differentially expressed among different tissues and contrasting cultivars of chickpea and lentil, respectively. Several gene categories were significantly modulated such as cell cycle, DNA transcription, energy metabolism, hormonal biosynthesis and signaling, proteolysis, and vegetative development between apical and axillary tissues and contrasting cultivars of chickpea and lentil. Based on differential expression and branching-associated biological function, ten chickpea genes and seven lentil genes were considered the main players involved in differentially regulating the plant branching between contrasting cultivars. These collective data putatively revealed the general mechanism and high-effect genes associated with the regulation of branching in chickpea and lentil, which are potential targets for manipulation through genome editing and transgenesis aiming to improve plant architecture.

Correlation between PD-1/PD-L1 and RANKL/OPG in chronic apical periodontitis model of Sprague-Dawley rats.

Chronic apical periodontitis (CAP) is characterized by inflammation and destruction of the apical periodontium that is of pulpal origin, appearing as an apical radiolucent area, and does not produce clinical symptoms. Little is known about whether the PD-1/PD-L1 ratio is associated with the balance between RANKL and OPG in CAP. The relationship between PD-1/PD-L1 and RANKL/OPG in CAP is investigated in this study. A CAP rat model was established using Sprague-Dawley rats. The pulp chambers were exposed to the oral cavity to allow bacterial contamination. The apical tissues of the bilateral mandibular first molars were analyzed for histological morphology using hematoxylin and eosin (H&E) staining. Immunohistochemistry and qRT-PCR were used to determine the expression of PD-1, PD-L1, OPG, and RANKL mRNA and proteins in periapical tissues and mandibular samples, respectively. The radiological images indicated a poorly defined low-density shadow and alveolar bone resorption after periodontitis induction. Histological analysis revealed an infiltration of inflammatory cells and alveolar bone resorption in the periapical tissues. Mandibular mRNA and periapical protein expression of PD-1, PD-L1, and RANKL was upregulated 7-28days after periodontitis induction, while the expression of OPG was downregulated. No significant relationship was observed between PD-1/PD-L1 and RANKL/OPG at either mRNA or protein levels in CAP. There is an increased expression of PD-1, PD-L1, and RANKL and a decreased expression of OPG, indicating progression of CAP.

Metformin switches cell death modes to soothe the apical periodontitis via ZBP1.

Apical periodontitis (AP) is a disease caused by pathogenic microorganisms and featured with the degradation of periapical hard tissue. Our recent research showed the crucial role of Z-DNA binding protein 1 (ZBP1)-mediated necroptosis and apoptosis in the pathogenesis of AP. However, the specific regulatory mechanisms of ZBP1 in AP are not fully elucidated. It was found that metformin has a regulatory role in cell necroptosis and apoptosis. But whether and how metformin regulates necroptosis and apoptosis through the ZBP1 in the context of AP remains unknown. This study provided evidence that lipopolysaccharide (LPS) promotes the synthesis of left-handed Z-nucleic acids (Z-NA), which in turn activates ZBP1. Knockout of Zbp1 by CRISPR/Cas9 technology significantly reduced LPS-induced necroptosis and apoptosis invitro. By using Zbp1-knockout mice, periapical bone destruction was alleviated. Moreover, type I interferon induced the expression of interferon-stimulated genes (ISGs), which serve as a major source of Z-NA. In addition, the RNA-editing enzyme Adenosine Deaminase RNA specific 1 (ADAR1) prevented the accumulation of endogenous Z-NA. Meanwhile, metformin suppressed the ZBP1-mediated necroptosis by inhibiting the expression of ZBP1 and the accumulation of ISGs. Metformin also promoted mitochondrial apoptosis, which is critical for the elimination of intracellular bacterial infection. The enhanced apoptosis further promoted the healing of infected apical bone tissues. In summary, these results demonstrated that the recognition of Z-NA by ZBP1 plays an important role in AP pathogenesis. Metformin suppressed ZBP1-mediated necroptosis and promoted apoptosis, thereby contributing to the soothing of inflammation and bone healing in AP.

E3 Ubiquitin Ligase ASB14 Inhibits Cardiomyocyte Proliferation by Regulating MAPRE2 Ubiquitination.

The ubiquitin proteasome system is a highly specific and selective protein regulatory system that plays an essential role in the regulation of the cell cycle. Despite its significance, the role of ubiquitination in cardiomyocyte proliferation remains largely unclear. This study aimed to investigate the potential impact of E3 ubiquitin ligase ASB14 (Ankyrin Repeat And SOCS Box Containing 14) on cardiac regeneration. We conducted a microarray analysis of apical resection ventricle tissues, and our findings revealed that ASB14 was down-regulated during the cardiac regenerative response. Subsequently, we examined the effect of ASB14 silencing on cardiomyocyte nuclear proliferation both in vitro and in vivo. Our results indicated that ASB14 silencing promoted cardiomyocyte nuclear proliferation, suggesting that ASB14 may play a role in regulating cardiac regeneration. To further investigate the potential therapeutic implications of ASB14 deficiency, we examined the cardiac function of mice with ASB14 deficiency in response to ischemic injury. Our findings showed that mice with ASB14 deficiency exhibited preserved cardiac function and a therapeutic effect in response to ischemic injury, which was attributed to the enhancement of cardiomyocyte nuclear proliferation. To elucidate the underlying mechanisms, we investigated the effect of ASB14 on microtubule-associated protein RP/EB family member 2 (MAPRE2) protein degradation. Our results indicated that the loss of ASB14 decreased the degradation of MAPRE2 protein, subsequently promoting cardiomyocyte nuclear proliferation and enhancing cardiac repair after myocardial infarction (MI). In conclusion, our study provides evidence that inhibition of ASB14-mediated MAPRE2 ubiquitination promotes cardiomyocyte nuclear proliferation, which may serve as a potential target for treating heart failure induced by MI injury.

Poly(Lysine)-Derived Carbon Quantum Dots Conquer Enterococcus faecalis Biofilm-Induced Persistent Endodontic Infections.

Persistent endodontic infections (PEIs) mediated by bacterial biofilm mainly cause persistent periapical inflammation, resulting in recurrent periapical abscesses and progressive bone destruction. However, conventional root canal disinfectants are highly damaging to the tooth and periodontal tissue and ineffective in treating persistent root canal infections. Antimicrobial materials that are biocompatible with apical tissues and can eliminate PEIs-associated bacteria are urgently needed. Here, ε-poly (L-lysine) derived carbon quantum dots (PL-CQDs) are fabricated using pyrolysis to remove PEIs-associated bacterial biofilms. Due to their ultra-small size, high positive charge, and active reactive oxygen species (ROS) generation capacity, PL-CQDs exhibit highly effective antibacterial activity against Enterococcus faecalis (E. faecalis), which is greatly dependent on PL-CQDs concentrations. 100 µg/mL PL-CQDs could kill E. faecalis in 5 min. Importantly, PL-CQDs effectively achieved a reduction of biofilms in the isolated teeth model, disrupting the dense structure of biofilms. PL-CQDs have acceptable cytocompatibility and hemocompatibility in vitro and good biosafety in vivo. Thus, PL-CQDs provide a new strategy for treating E. faecalis-associated PEIs.

Effect of EGCG-based paste as intracanal dressing, in MMPs 2 and 9 expression in dog's periapical lesions.

High expression of MMP-2 and MMP-9 in periapical lesions plays an important role in the degradation of the extracellular matrix. This study aimed to investigate the effect of epigallocatechin-3-gallate (EGCG)-based endodontic paste as an intracanal dressing on the expression of MMP-2 and MMP-9 in periapical lesions. Periapical lesions were experimentally induced in 35 mature beagle dog premolars randomly divided into healthy teeth, untreated periapical lesions, periapical lesions treated in a single session (control groups), and periapical lesions treated in two sessions with EGCG or calcium hydroxide-based pastes (experimental groups). After 120 days, specimens were obtained for histopathologic and immunofluorescence analyses to assess the expression of MMP-2 and MMP-9. The statistical analysis was performed using a p-value of 0.05. Endodontic treatment in two sessions using medication with EGCG and calcium hydroxide-based pastes provided similar repair of the apical and periapical tissues and neoformation of periodontal ligament fibers, cementum, and alveolar bone (p>0.05). The experimental groups treated in two sessions with both medications presented expression of MMP-2 and MMP-9 similar to that in healthy teeth (p>0.05), and significantly lower than teeth treated in a single session or untreated periapical lesions (p <0.001). Expression of MMP-2 and MMP-9 was observed in the cytoplasm of fibroblasts, osteoblasts, cementoblasts, cementocytes, and vascular endothelium. The use of EGCG-based endodontic paste reduced the expression of MMP-2 and MMP-9 and allowed repair of periapical lesions, similar to calcium hydroxide-based paste, and superior to treatment performed in a single session.

Influence of IgA nephropathy on the progression of pulpitis and apical periodontitis in HIGA mice

ObjectivesImmunoglobulin (Ig)A nephropathy has been associated with oral infections such as periodontitis, but its pathogenesis is not fully understood; no treatments exist. This study analyzes the influence of IgA nephropathy, an autoimmune disease, on the pathogenesis of pulpitis and apical periodontitis. MethodsTwo groups of mice were used in pulp infection experiments: high serum IgA nephropathy model mice (HIGA) and control mice (BALB/c). Histologic analyses of the pulp and apical periodontal tissues were performed on days 3, 5, 7, 14, and 28 following oral bacterial infection. The dynamics of odontoblasts, apoptotic cells, and IgA expression were analyzed using anti-Nestin, TUNEL, and anti-IgA staining, respectively. ResultsInflammatory cells infiltrated the exposed pulp at day three in both groups and by 14 days, these cells had infiltrated from the pulp to the apical periodontal tissue. The area of necrotic pulp tissue increased significantly in the control group at seven days. Odontoblasts decreased from day three onwards and disappeared by 28 days in both groups. The number of apoptotic cells in the pulp and apical periodontal tissues was significantly higher in the experimental group at day 28. The experimental group exhibited a significant increase in IgA production in the pulp after 14 days. Bone resorption in the apical periodontal tissue was significantly decreased in the experimental group at day 28. ConclusionsThe results of this study suggest that IgA nephropathy may modulate the inflammatory response and sustain long-term biological defense responses in pulpitis and apical periodontitis in HIGA mice.

Effect of Recombinant Human Platelet-Derived Growth Factor on Healing of Chronic Periapical Tissue Pathosis Following Apical Surgery in a Canine Model: A Histomorphometric and Microcomputed Tomography Analysis.

This canine in vivo study assessed the effect of recombinant human platelet-derived growth factor (rhPDGF) on the healing of periapical tissues following apical surgery. From a total of 96 premolar teeth, 64 teeth from six beagle dogs (2 years old) were classified as experimental and were randomly assigned to four experimental groups (16 teeth per group). After having the pulp extirpated, leaving teeth open to the oral cavity for 1 week, and sealing with an immediate restorative material for 8 weeks, nonsurgical endodontic treatment was performed. A split-mouth design was used, and intra-animal randomization of treatment sides was applied to the groups as follows: apical curettage + 1.5-mm root-end resection (Group 1); apicoectomy + mineral trioxide aggregate (MTA) root-end filling (Group 2); apicoectomy + MTA root-end filling + rhPDGF (Group 3); and apical curettage + rhPDGF (Group 4). The animals were sacrificed 24 months after apical surgery, and histologic and μCT analyses were performed for bone volume loss (BVL). Group 1 showed partial resolution of the periapical lesions without signs of tissue regeneration (BVL: 49.09 ± 10.97 mm3). Group 2 had minimal bone regeneration and showed cementum reformation in 9 teeth, with no direct attachment to the MTA (BVL: 35.34 ± 10.97 mm3). Group 3 showed regeneration of all damaged apical tissues without direct contact between the cementum and MTA (BLV: 4.51 ± 1.55 mm3). Group 4 showed regeneration of PDL, bone, and cementum and attachment of functional cementum fibers (BVL: 2.82 ± 2.3 mm3). The difference in BVL was statistically significant only for Groups 1 and 2 (P < .05). rhPDGF may help regenerate apical tissue structures following apical surgery.

Clinical determination of anatomical diameter in different dental groups correlating them with gender, age, tooth/canal and pulpoperiradicular diagnosis: an observational clinical study

The aim of this observational clinical study (OCS) was to determine the clinical anatomical diameter (CAD) in several dental groups, thus correlating them with gender, age, tooth/canal and pulpoperiradicular diagnosis. Three-hundred fifty-nine teeth/584 vital or necrotic root canals from patients of both genders and different ages composed the sample. After performing the necessary previous procedures, K-Flexofiles were used to determine the CAD. Then, the gender and age of the patients, as well as the pulpoperiradicular diagnosis of the teeth were tabulated to conduct the statistical analysis (p < 0.05). Of the 359 teeth/584 root canals evaluated, 208/342 were from women (mean age 38.85 ± 13.42 years) and 151/242 were from men (mean age 45.41 ± 14.90 years). Statistically significant differences between the CAD means of root canals from women and men were not identified (p = 0.411). The analysis of the correlation between the CAD and age also showed a total independence (p = 0.271). Teeth with pulp necrosis and asymptomatic apical periodontitis diagnosed radiographically (TPNAAPDR) had a significantly larger CAD mean than teeth with pulp necrosis and no asymptomatic apical periodontitis diagnosed radiographically (TPNNAAPDR) and teeth with vital pulp and normal apical tissues (TVPNAT) (p = 0.0297); and the last two did not differ statistically (p > 0.05). The largest CAD mean was observed in single canals of maxillary central incisors. The lowest values of this variable were identified in the mesiobuccal and mesial canals of maxillary and mandibular first molars, respectively. The CAD of the root canals was influenced only by the root canal/tooth and pulpoperiradicular diagnosis.

Long-Term Clinical and Radiographic Observation of Previously Regenerated Treated Incisors Subjected to Orthodontic Movement. A Case Series

IntroductionWith an increasing number of anterior traumatized teeth treated with regenerative endodontic procedures (REPs) nowadays, orthodontic movement of such teeth is expected to become a common scenario in everyday clinical practice. However, little is known about the clinical implications and the response capacity of regenerated tissues to orthodontic forces. MethodsThe aim of this clinical article was to report on 4 cases of REP-treated immature anterior permanent teeth subjected to orthodontic forces, and to describe the long-term response of the regenerated apical and intracanal tissues. ResultsSigns of orthodontic-induced external root resorption were observed in 2 of the 4 presented cases without, however, the presence of any associated adverse events. No other complications were observed, either clinically or radiographically, throughout the observation period. In the long-term, all 4 cases responded favorably to orthodontic forces, maintaining healthy apical tissues and structural integrity of both intracanal as well as apically regenerated tissues. ConclusionsThe orthodontic movement of REP-treated teeth seems feasible, nevertheless, special care should be implemented. Lightly acting orthodontic forces, short duration of active movement, and close monitoring of the patient seem to be prerequisites to limit complications to a minimum and achieve a favorable healing of REP-treated teeth in the long-term following orthodontic treatment completion.

Heterogeneity in macrophages along the cochlear spiral in mice: insights from SEM and functional analyses.

The susceptibility of sensory cells to pathological conditions differs between the apical and basal regions of the cochlea, and the cochlear immune system may contribute to this location-dependent variability. Our previous study found morphological differences in basilar membrane macrophages between the apical and basal regions of the cochlea. However, the details of this site-dependent difference and its underlying structural and biological basis are not fully understood. In this study, we utilized scanning electron microscopy to examine the ultrastructure of macrophages and their surrounding supporting structures. Additionally, we examined the phagocytic activities of macrophages and the expression of immune molecules in both apical and basal regions of the cochlea. We employed two mouse strains (C57BL/6J and B6.129P-Cx3cr1tm1Litt/J) and evaluated three experimental conditions: young normal (1-4 months), aging (11-19 months), and noise-induced damage (120 dB SPL for 1 h). Using scanning electron microscopy, we revealed location-specific differences in basilar membrane macrophage morphology and surface texture, architecture in mesothelial cell layers, and spatial correlation between macrophages and mesothelial cells in both young and older mice. Observations of macrophage phagocytic activities demonstrated that basal macrophages exhibited greater phagocytic activities in aging and noise-damaged ears. Furthermore, we identified differences in the expression of immune molecules between the apical and basal cochlear tissues of young mice. Finally, our study demonstrated that as the cochlea ages, macrophages in the apical and basal regions undergo a transformation in their morphologies, with apical macrophages acquiring certain basal macrophage features and vice versa. Overall, our findings demonstrate apical and basal differences in macrophage phenotypes and functionality, which are related to distinct immune and structural differences in the macrophage surrounding tissues.

Periradicular tissue fluid-derived biomarkers for apical periodontitis: An in vitro methodological and in vivo cross-sectional study.

Periradicular tissue fluid (PTF) offers a source of diagnostic, prognostic and predictive biomarkers for endodontic disease. (1) To optimize basic parameters for PTF paper point sampling in vitro for subsequent in vivo application. (2) To compare proteomes of PTF from teeth with normal apical tissues (NAT) and asymptomatic apical periodontitis (AAP) using high-throughput panels. (1) To assess volume absorbance, paper points (n = 20) of multiple brands, sizes and sampling durations were inserted into PBS/1%BSA at several depths. Wetted lengths (mm) were measured against standard curves to determine volume absorbance (μL). To assess analyte recovery, paper points (n = 6) loaded with 2 μL recombinant IL-1β (15.6 ng/mL) were eluted into 250 μL: (i) PBS; (ii) PBS/1% BSA; (iii) PBS/0.1% Tween20; (iv) PBS/0.25 M NaCl. These then underwent: (i) vortexing; (ii) vortexing/centrifugation; (iii) centrifugation; (iv) incubation/vortexing/centrifugation. Sandwich-ELISAs determined analyte recovery (%) against positive controls. (2) Using optimized protocols, PTF was retrieved from permanent teeth with NAT or AAP after accessing root canals. Samples, normalized to total fluid volume (TFV), were analysed to determine proteomic profiles (pg/TFV) of NAT and AAP via O-link Target-48 panel. Correlations between AAP and diagnostic accuracy were explored using principal-component analysis (PCA) and area under receive-operating-characteristic curves (AUC [95% CI]), respectively. Statistical comparisons were made using Mann-Whitney U, anova and post hoc Bonferonni tests (α < .01). (1) UnoDent's 'Classic' points facilitated maximum volume absorbance (p < .05), with no significant differences after 60 s (1.6 μL [1.30-1.73]), 1 mm depth and up to 40/0.02 (2.2 μL [1.98-2.20]). For elution, vortexing (89.3%) and PBS/1% BSA (86.9%) yielded the largest IL-1β recovery (p < .05). (2) 41 (NAT: 13; AAP: 31) PTF samples proceeded to analysis. The panel detected 18 analytes (CCL-2, -3, -4; CSF-1; CXCL-8, -9; HGF; IL-1β, -6, -17A, -18; MMP-1, -12; OLR-1; OSM; TNFSF-10, -12; VEGF-A) in ≥75% of AAP samples at statistically higher concentrations (p < .01). CXCL-8, IL-1β, OLR-1, OSM and TNFSF-12 were strongly correlated to AAP. 'Excellent' diagnostic performance was observed for TNFSF-12 (AUC: 0.94 [95% CI: 0.86-1.00]) and the PCA-derived cluster (AUC: 0.96 [95% CI: 0.89-1.00]). Optimized PTF sampling parameters were identified in this study. When applied clinically, high-throughput proteomic analyses revealed complex interconnected networks of potential biomarkers. TNFSF-12 discriminated periradicular disease from health the greatest; however, clustering analytes further improved diagnostic accuracy. Additional independent investigations are required to validate these findings.

The role of trace elements in the pathomorphology of destructive forms of periodontitis of an infectious nature

Aim. To study and analyze the role of trace elements in pathomorphological changes occurring in teeth with destructive forms of apical periodontitis in the acute stage by means of light and electron microscopy.Materials and methods. Pathological changes were studied on 46 teeth with destructive forms of periodontitis in the acute stage using an Olympus BX-40 light microscope. Scanning electron microscopy was used to conduct X-ray microanalysis of 10 teeth.Results. The infiltration of the inflammatory focus is an indirect evidence of a change in the balance between the production of oxygen radicals by phagocytic cells in destructive forms of periodontitis and their elimination, which includes multifaceted interrelated factors, namely, direct damage to biomolecules, increased signaling of the nuclear factor, and cell death. The increased amount of studied chemical elements in the tissues of teeth with apical forms of periodontitis during the period of exacerbation allows us to assume that oxygen can become a source of free radicals and stimulate the process of resorption of the tooth root.Conclusions. Cellular infiltration found in biopsy specimens of teeth with destructive forms of periodontitis in the acute stage, as well as an increased content of trace elements in dental tissues, suggests that this contributes not only to loss of bone mass in the periapical space, but also leads to the destruction of apical tissues. Trace elements are biomarkers of oxidative stress. Treatment should be aimed at accelerating the restoration of oxidative balance.

ANALYSIS OF ROOT CANAL CHARACTERISTICS OF MAXILLARY INCISORS WITH CONE BEAM COMPUTED TOMOGRAPHY

Pulpitis is a common oral disease that greatly affects the health as well as the quality of life of patients. Which if left untreated or poorly treated can lead to inflammation of apical tissues [3]. Root canal treatment (endodontic treatment) aimed at eliminating bacteria, preserving and restoring mechanical function of teeth. Root canal treatment takes time, instrument and depends on doctor's skills and clinical experience. It is clear that the additional information provided by CBCT may increase and/or improve diagnostic accuracy and confidence in decision-making as well as have an impact of treatment planning. More clinical studies are required to assess the long-term impact of CBCT on the outcomes of endodontic treatment [10]. In Vietnam, cone beam computed tomography (CBCT) is a new technology in the field of endodontics with multiple advantageous features such as establishing 3D images of the root canal system with a low dose of X rays, providing more information, true spatial relationships, and image data can be sectioned. Hence, CBCT is highly beneficial and has high value in the field of endodontics, especially in cases of teeth with complex root canal systems. With the desire to apply science and technology into clinical pratice, we carry out this study: "Analysis of root canal characteristics of maxillary incisors with cone beam computed tomography” with the 2 aims:&#x0D; &#x0D; To evaluate the number of root canals in maxillary incisors.&#x0D; To analyze curvature and morphology of the root canal system in maxillary incisors.&#x0D;

Role of Interleukin-17A in Endodontic Disease

Background: Endodontic disease is a complicated condition marked by inflammation of the apical tissues and is influenced by microbial, immunological, and environmental variables. Inflammatory cells, proinflammatory, and immunoregulatory cytokines are all recruited as part of the intricate immunological host response that occurs here; one of these cytokines is interleukin-17A (IL-17A). Objectives: This study aimed to determine the concentration of IL-17A by Enzyme Linked ImmunoSorbent Assay (ELISA) in the saliva of patients with endodontic disease to find the correlation between IL-17A and endodontic disease. Materials and Methods: The samples are collected from 60 patients (n = 60) with an age range of 20–50 years. The samples are collected from specialized dental centers and private clinics throughout the time period (December 2021–February 2022). The control samples are 20 (n = 20). The rate of samples was divided between males and females with ratios of 43.33% and 56.66%, respectively. Results: The result showed that the concentration of IL-17A was increased in patients compared with the control P-value (0.000). The difference in age showed no effect on the results of this study. Conclusion: This study showed that proinflammatory cytokines start immune responses in pulp tissues after bacterial infections and imply IL-17A endodontic illness.

NLRP3 Disturbs Treg/Th17 Cell Balance to Aggravate Apical Periodontitis

Apical periodontitis is an inflammatory condition that is considered an immunological reaction of the periapical tissue to invading bacteria and their pathogenic components. Recent research has revealed that NLR family pyrin domain containing 3 (NLRP3) is crucial to the pathogenesis of apical periodontitis and serves as a link between innate and adaptive immunity. The balance between regulatory T-cell (Treg) and T helper cell 17 (Th17 cell) determines the direction of the inflammatory response. Therefore, this study aimed to investigate whether NLRP3 exacerbated periapical inflammation by disturbing Treg/Th17 balance and the underlying regulatory mechanisms. In the present study, NLRP3 was raised in apical periodontitis tissues as opposed to healthy pulp tissues. Low NLRP3 expression in dendritic cells (DCs) increased transforming growth factor β secretion while decreasing interleukin (IL)–1β and IL-6 production. The Treg ratio and IL-10 secretion rose when CD4+ T cells were cocultured with DCs primed with IL-1β neutralizing antibody (anti–IL-1β) and specific small interfering RNA (siRNA) targeting NLRP3 (siRNA NLRP3), but the proportion of Th17 cells and IL-17 release dropped. Furthermore, siRNA NLRP3-mediated suppression of NLRP3 expression aided Treg differentiation and elevated Foxp3 expression as well as IL-10 production in CD4+ T cells. Inhibition of NLRP3 activity by MCC950 boosted the percentage of Tregs while decreasing the ratio of Th17 cells, leading to reduced periapical inflammation and bone resorption. Nigericin administration, however, exacerbated periapical inflammation and bone destruction with an unbalanced Treg/Th17 response. These findings demonstrate that NLRP3 is a pivotal regulator by regulating the release of inflammatory cytokines from DCs or directly suppressing Foxp3 expression to disturb Treg/Th17 balance, thus exacerbating apical periodontitis.