Hydroxyphenylpyruvate Dioxygenase Is a Metabolic Immune Checkpoint for UTX-deficient Colorectal Cancer.

BACKGROUND & AIMS: Aberrant epigenetic events mediated by histone methyltransferases and demethylases contribute to malignant progression of colorectal cancer (CRC). However, the role of the histone demethylase ubiquitously transcribed tetratricopeptide repeat on chromosome X (UTX) in CRC remains poorly understood. METHODS: UTX conditional knockout mice and UTX-silenced MC38 cells were used to investigate UTX function in tumorigenesis and development of CRC. We performed time of flight mass cytometry to clarify the functional role of UTX in remodeling immune microenvironment of CRC. To investigate metabolic interaction between myeloid-derived suppressor cells (MDSCs) and CRC, we analyzed metabolomics data to identify metabolites secreted by UTX-deficient cancer cells and taken up by MDSCs. RESULTS: We unraveled a tyrosine-mediated metabolic symbiosis between MDSC and UTX-deficient CRC. Loss of UTX in CRC resulted in methylation of phenylalanine hydroxylase, preventing its degradation and subsequently increasing tyrosine synthesis and secretion. Tyrosine taken up by MDSCs was metabolized to homogentisic acid by hydroxyphenylpyruvate dioxygenase. Homogentisic acid modified protein inhibitor of activated STAT3 via carbonylation of Cys 176, and relieved the inhibitory effect of protein inhibitor of activated STAT3 on signal transducer and activator of transcription 5 transcriptional activity. This in turn, promoted MDSC survival and accumulation, enabling CRC cells to acquire invasive and metastatic traits. CONCLUSIONS: Collectively, these findings highlight hydroxyphenylpyruvate dioxygenase as a metabolic checkpoint to restrict immunosuppressive MDSCs and to counteract malignant progression of UTX-deficient CRC.

ARNTL inhibits the malignant behaviors of oral cancer by regulating autophagy in an AKT/mTOR pathway-dependent manner.

Current studies have shown that ARNTL, an important clock gene, plays an anticancer role and is downregulated in certain types of cancer. However, the biological functions and mechanisms of ARNTL in tumors remain largely unknown. This study aimed to elucidate how ARNTL-induced autophagy impacts the biological properties of tongue squamous cell carcinoma (TSCC) cells and the mechanisms by which ARNTL expression activates autophagy. ARNTL was stably overexpressed in TSCC cells to investigate its functions in vitro and in vivo. We found that activation of autophagy induced by ARNTL decreases cell proliferation, enhances cell death, and hinders the migratory ability of TSCC cells. Moreover, ARNTL antagonizes the AKT/mTOR pathway, which potentiates autophagy induction. The manipulation of Akt activation cancels the effects of ARNTL overexpression on the biological behaviors of TSCC cells. Furthermore, after the addition of SC79, the upregulated BAX expression due to ARNTL overexpression and downregulated expressions of BCL-2 and MMP2 were remarkably rescued. In vivo tumorigenicity assays and immunohistochemistry also confirmed that ARNTL overexpression suppresses tumor development. Our study found for the first time that ARNTL inhibits the malignant behaviors of oral cancer cells by regulating autophagy in an AKT/mTOR pathway-dependent manner, which provides a novel theoretical basis for the potential future application of ARNTL to treat patients with oral cancer.

Oral microbial communities in 5-year-old children with versus without dental caries.

BACKGROUND: Caries in young children has received more and more attention. The study of the oral microbiota may help to understand the polymicrobial etiology of dental caries. OBJECTIVES: To investigate the diversity and structure of microbial communities in saliva samples from 5-year-old children with versus without dental caries. METHODS: A total of 36 saliva samples were collected from 18 children with high caries (HB group) and from 18 children without caries (NB group). Then, 16S rDNA was amplified from bacterial samples using polymerase chain reaction, and high-throughput sequencing was performed using Illumina Novaseq platforms. RESULTS: Sequences were clustered into operational taxonomic units (OTUs), which were distributed among 16 phyla, 26 classes, 56 orders, 93 families, 173 genera, and 218 species. Firmicutes, Bacteroides, Proteobacteria, Actinobacteria, Fusobacteria, Patescibacteria, Epsilonbacteraeota, Cyanobacteria, Acidobacteria and Spirochaetes were basically the same in different groups, but their relative abundances were different. The core microbiome was defined as the species from 218 shared microbial taxa. The alpha diversity test showed that there were no significant differences in microbial abundance and diversity between the high caries and no caries groups. The results from principal coordinate analysis (PCoA) and hierarchical clustering showed that the two groups had similar microorganisms. The biomarkers of different groups were defined by LEfSe analysis to identify potential caries-related and health-related bacteria. Co-occurrence network analysis of dominant genera showed that oral microbial communities in the no caries group were more complex and aggregated than those in the high caries group. Finally, the PICRUSt algorithm was used to predict the function of the microbial communities from saliva samples. The obtained results showed that mineral absorption was greater in the no caries group than in the high caries group. BugBase was used to determine phenotypes present in microbial community samples. The obtained results showed that Streptococcus was greater in the high caries group than in the no caries group. CONCLUSION: Findings of this study provide a comprehensive understanding of the microbiological etiology of dental caries in 5-year-old children and are expected to provide new methods for its prevention and treatment.

Modeling turbulence in underwater wireless optical communications based on Monte Carlo simulation: comment.

This note aims to report and correct a mistake in the mentioned paper [J. Opt. Soc. Am. A34, 1187 (2017)JOAOD60740-323210.1364/JOSAA.34.001187]. The quadratic equation given in the paper to provide the solution to the possible refractive direction of a transmitted photon after interacting with the curved turbulent boundary is incorrect due to neglecting the refractive index variation along the propagation link. The revised equation is provided and substantiated by numeric simulation results.

Doppler Shift Tolerance of Typical Pseudorandom Binary Sequences in PMCW Radar.

In the context of all-digital radar systems, phase-modulated continuous wave (PMCW) based on pseudorandom binary sequences (PRBSs) appears to be a prominent candidate modulation scheme for applications such as autonomous driving. Among the reasons for its candidacy are its simplified transmitter architecture and lower linearity requirements (e.g., compared to orthogonal-frequency division multiplexing radars), as well as its high velocity unambiguity and multiple-input multiple-output operation capability, all of which are characteristic of digital radars. For appropriate operation of a PMCW radar, choosing a PRBS whose periodic autocorrelation function (PACF) has low sidelobes and high robustness to Doppler shifts is paramount. In this sense, this article performs an analysis of Doppler shift tolerance of the PACFs of typically adopted PRBSs in PMCW radar systems supported by simulation and measurement results. To accurately measure the Doppler-shift-induced degradation of PACFs, peak power loss ratio (PPLR), peak sidelobe level ratio (PSLR), and integrated-sidelobe level ratio (ISLR) were used as metrics. Furthermore, to account for effects on targets whose ranges are not multiples of the range resolution, oversampled PACFs are analyzed.

Root Anatomy and Root Canal Morphology of Maxillary Second Permanent Molars in a Chongqing Population: A Cone-Beam Computed Tomography Study.

BACKGROUND To investigate variations in the anatomy of root canals in permanent second molars of the upper jaw in a population in Chongqing, China, using cone-beam computed tomography (CBCT). MATERIAL AND METHODS CBCT imaging data of 400 second permanent molars of the upper jaws of 200 patients were retrospectively reviewed. Patients' gender, age, numbers of roots and canals, root fusion of permanent second molars of the maxilla on both sides, and morphological categories of root canals of mesiobuccal roots were recorded. The distances from the apices of the distobuccal and mesiobuccal roots to the buccal bone plate were measured. RESULTS Of the 400 permanent second maxillary molars, 312 (78.0%) had three roots and 247 (61.75%) had three canals. Fused roots were observed in 126 (31.5%) teeth; of these, 67 (53.2%) had three canals and 44 (34.9%) had two canals. Morphologically, 297 (74.25%), 29 (7.25%), nine (2.25%) and 65 (16.25%) teeth had type I, II, III, and IV mesiobuccal root canals, respectively, with 103 (25.75%) having secondary mesiobuccal canals. The distances from the apices of the mesiobuccal, distobuccal, and single buccal roots to the surface of the buccal osseous lamella were 7.34±1.89 mm, 6.26±1.74 mm, and 8.60±2.56 mm, respectively. CONCLUSIONS The root form and canal shape of permanent second molars of the upper jaw varied greatly among the population of Chongqing, China. CBCT is a valuable method for assessing the complex anatomic morphology of teeth.

The Effects of a Toothpaste Containing the Active Ingredients of Galla chinensis and Sodium Fluoride on Dentin Hypersensitivity and Sealing of Dentinal Tubules: An In Vitro Study and an Eight-Week Clinical Study in 98 Patients.

BACKGROUND This study aimed to evaluate the desensitizing effect of toothpaste containing the active ingredients of an extract of Galla chinensis, both in vitro and in patients with dentin hypersensitivity. MATERIAL AND METHODS Ninety-eight patients with dentin hypersensitivity were divided into two study groups and given toothpaste containing either the active ingredients of Galla chinensis extract and sodium fluoride, or a control toothpaste containing only sodium fluoride. Assessments included the tactile stimulation test and the Schiff cold air sensitivity scale, which were conducted at the baseline examination and after 4 and 8 weeks of dental brushing. Twenty-five intact human premolars from 24 patients with dentin hypersensitivity were prepared and randomly divided into four groups, the untreated baseline group, the study group, the positive control group, and the control group. After brushing with different toothpaste for 7 days, the effects on dentinal tubule sealing in each group was determined by scanning electron microscopy (SEM), and the degree of dentinal tubule plugging and diameter of the open dentinal tubules were calculated. RESULTS Toothpaste containing the active ingredients of Galla chinensis and sodium fluoride significantly reduced the degree of dentin hypersensitivity when compared with toothpaste containing sodium fluoride alone after 4 weeks and 8 weeks of use. Toothpaste containing the active ingredients of Galla chinensis significantly reduced the number and diameter of the open dentinal tubules. CONCLUSIONS Toothpaste that contained the active ingredients of Galla chinensis and sodium fluoride reduced the symptoms of dentin hypersensitivity by sealing the dentinal tubules.

Sealing effects of different Chinese herbal medicines on dentinal tubules: a scanning electron microscopic observation.

BACKGROUND AND OBJECTIVES: To evaluate the sealing effects of different Chinese herbal medicines on dentinal tubules, and to provide a reference for the clinical treatment of dentin hypersensitivity. METHODS: Forty dentin slices prepared by freshly extracted bovine mandibular central incisors were randomly assigned to procyanidins, tannic acid, gallic acid, naringin, epigallocatechin gallate (EGCG), glycyrrhizic acid, paeonol, and blank groups. Dentin slices in each Chinese herbal medicine group were treated three times a day, each for 5 min, and then immersed in a remineralization solution for the rest of the time. Dentin slices in the blank group were directly immersed in the remineralization solution for 7 days. The dentinal tubule sealing effect was observed under the scanning electron microscope (SEM). RESULTS: SEM results showed that the dentinal tubules were almost completely open in the blank group, which was mostly open in the gallic acid, EGCG, glycyrrhizic acid, and paeonol groups, and were sealed in procyanidins, tannic acid, and naringin groups. Significant differences were detected in mean area, mean diameter of dentinal tubules, and mean plugging rate of dentinal tubules between the remaining Chinese herbal medicine groups and blank group (P < .05). Among them, the dentinal tubule sealing effect of procyanidins, tannic acid, and naringin was obvious. CONCLUSION: The findings suggested that procyanidins, tannic acid, and naringin can effectively seal dentinal tubules, which provided a basis for clinical treatment of dentin hypersensitivity.

[Effect of low intensity pulsed ultrasound on expression of TGF-ß1 and Smads during dentin injury and repair].

OBJECTIVE: To explore the effect of low intensity pulsed ultrasound (LIPUS) on TGF-ß1/Smad 2, 3 signal pathway during the dentin injury and repair.
 Methods: Among 25 Sprague-Dawley rats, 5 rats served as a blank control group without treatment. The remaining 20 rats received modified caries preparation inbilateral maxillary first molars to establish a model of dentin-pulp injury and repair. The right maxillary first molars served as a LIPUS group, which received LIPUS irradiation (frequency: 1.5 MHz, pulse width: 200 µs, pulse repetition frequency: 1 kHz, spatial averaged temporal averaged intensity: 30 mW/cm2, 20 min/d), and the left maxillary first molars served as a cavity-prepared group, which received fake LIPUS irradiation. The rats were sacrificed at 1, 3, 5, 7 and 14 days after LIPUS irradiation. Immunohistochemical staining and Image-pro plus 6.0 were applied to detect the expression and distribution of transforming growth factor-beta1 (TGF-ß1) and small mothers against decapentaplegic 2/3(Smad 2 and Smad 3).
 Results: Immunohistochemical staining showed that the expression of TGF-ß1 and Smad 2, 3 were low innormal pulp, but they were increased in different degree after dentin injury. The result of image analysis showed that the expression of TGF-ß1 in the cavity-prepared group gradually increased at the first day and peaked at day 5, and then it returned to normal level at day 14. However, the expression of TGF-ß1 in the LIPUS group were significantly higher than that in the cavity-prepared group at day 3 and 5 (both P<0.05). The expressions of Smad 2,3 in both the LIPUS group and the cavity-prepared group were consistently increased all the way, but the expressions in the LIPUS group were higher compared with that in the cavity-prepared group (P<0.05).
 Conclusion: The TGF-ß1/Smad 2, 3 signal pathway can be activated during the dentin injury and repair. LIPUS can up-regulate the expression of TGF-ß1 and Smad 2, 3 in the early period, which may take part in the dentin-pulp complex injury and repair process.

Luteolin enhances drug chemosensitivity by downregulating the FAK/PI3K/AKT pathway in paclitaxel­resistant esophageal squamous cell carcinoma.

Drug resistance is a key factor underlying the failure of tumor chemotherapy. It enhances the stem­like cell properties of cancer cells, tumor metastasis and relapse. Luteolin is a natural flavonoid with strong anti­tumor effects. However, the mechanism(s) by which luteolin protects against paclitaxel (PTX)­resistant cancer cell remains to be elucidated. The inhibitory effect of luteolin on the proliferation of EC1/PTX and EC1 cells was detected by cell counting kit­8 assay. Colony formation and flow cytometry assays were used to assess clonogenic capacity, cell cycle and apoptosis. Wound healing and Transwell invasion tests were used to investigate the effects of luteolin on the migration and invasion of EC1/PTX cells. Western blotting was used to detect the protein levels of EMT­related proteins and stem cell markers after sphere formation. Parental cells and drug­resistant cells were screened by high­throughput sequencing to detect the differential expression of RNA and differential genes. ELISA and western blotting were used to verify the screened PI3K/Akt signaling pathway, key proteins of which were explored by molecular docking. Hematoxylin and eosin staining and TUNEL staining were used to observe tumor xenografts on morphology and apoptosis in nude mice. The present study found that luteolin inhibited tumor resistance (inhibited proliferation, induced cell cycle arrest and apoptosis and hindered migration invasion, EMT and stem cell spherification) in vitro in PTX­resistant esophageal squamous cell carcinoma (ESCC) cells. In addition, luteolin enhanced drug sensitivity and promoted the apoptosis of drug­resistant ESCC cells in combination with PTX. Mechanistically, luteolin may inhibit the PI3K/AKT signaling pathway by binding to the active sites of focal adhesion kinase (FAK), Src and AKT. Notably, luteolin lowered the tumorigenic potential of PTX­resistant ESCC cells but did not show significant toxicity in vivo. Luteolin enhanced drug chemosensitivity by downregulating the FAK/PI3K/AKT pathway in PTX­resistant ESCC and could be a promising agent for the treatment of PTX­resistant ESCC cancers.

The mammalian actin elongation factor ENAH/MENA contributes to autophagosome formation via its actin regulatory function.

Macroautophagy/autophagy is a catabolic process crucial for degrading cytosolic components and damaged organelles to maintain cellular homeostasis, enabling cells to survive in extreme extracellular environments. ENAH/MENA, a member of the Ena/VASP protein family, functions as a highly efficient actin elongation factor. In this study, our objective was to explore the role of ENAH in the autophagy process. Initially, we demonstrated that depleting ENAH in cancer cells inhibits autophagosome formation. Subsequently, we observed ENAH's colocalization with MAP1LC3/LC3 during tumor cell starvation, dependent on actin cytoskeleton polymerization and the interaction between ENAH and BECN1 (beclin 1). Additionally, mammalian ATG9A formed a ring-like structure around ENAH-LC3 puncta during starvation, relying on actin cytoskeleton polymerization. Furthermore, ENAH's EVH1 and EVH2 domains were found to be indispensable for its colocalization with LC3 and BECN1, while the PRD domain played a crucial role in the formation of the ATG9A ring. Finally, our study revealed ENAH-led actin comet tails in autophagosome trafficking. In conclusion, our findings provide initial insights into the regulatory role of the mammalian actin elongation factor ENAH in autophagy.Abbreviations: 3-MA 3-methyladenine; ABPs actin-binding proteins; ATG autophagy related; ATG9A autophagy related 9A; Baf A1 bafilomycin A1; CM complete medium; CytERM endoplasmic reticulum signal-anchor membrane protein; Cyto D cytochalasin D; EBSS Earl's balanced salt solution; ENAH/MENA ENAH actin regulator; EVH1 Ena/VASP homology 1 domain; EVH2 Ena/VASP homology 2 domain; GAPDH glyceraldehyde-3-phosphate dehydrogenase; Lat B latrunculin B; LC3-I unlipidated form of LC3; LC3-II phosphatidylethanolamine-conjugated form of LC3; MAP1LC3/LC3 microtubule associated protein 1 light chain 3; mEGFP monomeric enhanced green fluorescent protein; mTagBFP2 monomeric Tag blue fluorescent protein 2; OSER organized smooth endoplasmic reticulum; PRD proline-rich domain; PtdIns3K class III phosphatidylinositol 3-kinase; WM wortmannin.

Remineralization efficacy of a toothpaste containing 8% arginine and calcium carbonate on enamel surface.

PURPOSE: To investigate the remineralization efficacy of different types of toothpastes on initial enamel lesions in vitro. METHODS: Artificial initial lesions were created on 150 enamel discs from freshly extracted bovine incisors. These enamel discs were divided into five groups. The test treatment consisted of undiluted Colgate Sensitive Pro-Relief Toothpaste containing 8.0% arginine, calcium carbonate and 1,450 ppm fluoride that was applied on the enamel surface under a pH-cycling including 4 x 3-minute application daily for 12 days and soaked in remineralizing solution during the untreated periods. The two other test products were commercial products: Crest Cavity Protection Toothpaste, containing 0.11% fluoride and GC Tooth Mousse, a professional remineralizing treatment paste (the active ingredients: casein phosphopeptide - amorphous calcium phosphate, fluoride). NaF solution (0.14% fluoride) was used as the positive control, while double distilled water (ddH2O) was used as the negative control. The remineralization of enamel discs was evaluated using Knoop hardness test, confocal laser scanning microscopy (CLSM) and polarized light microscopy (PLM), and the caries lesion depth was quantified using an image analyzer. The data were analyzed by ANOVA. RESULTS: All test products showed a recovery of the Knoop Hardness Number (KHN) after remineralization cycling treatment. The recovery of enamel KHN for Colgate Sensitive Pro-Relief, GC Mousse, Crest toothpasteand NaF groups were 44.53 +/- 6.72%, 35.00 +/- 7.83%, 24.56 +/- 5.95% and 42.51 +/- 6.74% respectively, while the recovery of negative control group was 18.99 +/- 4.98%. PLM results indicated the lesion depth recovery of 49.63 +/- 8.06%, 35.08 +/- 2.19%, 22.60 +/- 7.30% and 53.20 +/- 1.48% respectively, which were also significantly greater than that of the negative group (20.51 +/- 4.80%). CLSM analysis showed a reduction of average area, and total and average dye fluorescence of the lesions after treatment. The Colgate Sensitive Pro-Relief group presented significantly greater remineralization than the other toothpaste groups, while the Crest toothpaste group showed the lowest remineralization ability.

An improved method for preparing stained ground teeth sections.

Objective: In oral histopathology teaching and research, there is a need for high-quality undemineralized tooth sections that are easy to handle, have controlled thickness, allow the observation of intact microstructures, and can be preserved for long periods of time. Methods: Teeth were collected under non-demineralizing conditions. Tooth sections (15-25 µm) were prepared using a diamond knife, then randomly divided into three groups: (1) stained with rosin, (2) stained with hematoxylin and eosin, or (3) not stained. The prepared tooth sections were evaluated by microscopy for clarity and microstructure visibility. Results: The use of a diamond knife in the sectioning and grinding process yielded high-quality ground sections of teeth. Rosin-stained ground sections allowed better identification of microstructures within the teeth, compared with unstained or hematoxylin and eosin-stained ground sections. Conclusion: The best results were obtained in the ground sections of teeth that were stained with rosin. Ground sections of teeth prepared using this staining method could be useful in oral histopathology teaching and research.

Untargeted metabolomics of saliva in pregnant women with and without gestational diabetes mellitus and healthy non-pregnant women.

Objective: The aim of this study was to compare the differences in salivary metabolites between pregnant women with gestational diabetes mellitus (GDM), healthy pregnant women (HPW), and healthy non-pregnant women (HNPW), and analyze the possible associations between the identified metabolites and gingivitis. Method: The study included women with GDM (n = 9, mean age 28.9 ± 3.6 years, mean gestational age 30.1 ± 3.2 weeks), HPW (n = 9, mean age 27.9 ± 3.0 years, mean gestational age 28.6 ± 4.7 weeks), and HNPW (n = 9, mean age 27.7 ± 2.1 years). Saliva samples were collected from all participants and were analyzed with LC-MS/MS-based untargeted metabolomic analysis. Metabolite extraction, qualitative and semi-quantitative analysis, and bioinformatics analysis were performed to identify the differential metabolites and metabolic pathways between groups. The identified differential metabolites were further analyzed in an attempt to explore their possible associations with periodontal health and provide evidence for the prevention and treatment of periodontal inflammation during pregnancy. Results: In positive ion mode, a total of 2,529 molecular features were detected in all samples, 166 differential metabolites were identified between the GDM and HPW groups (89 upregulated and 77 downregulated), 823 differential metabolites were identified between the GDM and HNPW groups (402 upregulated and 421 downregulated), and 647 differential metabolites were identified between the HPW and HNPW groups (351 upregulated and 296 downregulated). In negative ion mode, 983 metabolites were detected in all samples, 49 differential metabolites were identified between the GDM and HPW groups (29 upregulated and 20 downregulated), 341 differential metabolites were identified between the GDM and HNPW groups (167 upregulated and 174 downregulated), and 245 differential metabolites were identified between the HPW and HNPW groups (112 upregulated and 133 downregulated). A total of nine differential metabolites with high confidence levels were identified in both the positive and negative ion modes, namely, L-isoleucine, D-glucose 6-phosphate, docosahexaenoic acid, arachidonic acid, adenosine, adenosine-monophosphate, adenosine 5'-monophosphate, xanthine, and hypoxanthine. Among all pathways enriched by the upregulated differential metabolites, the largest number of pathways were enriched by four differential metabolites, adenosine, adenosine 5'-monophosphate, D-glucose 6-phosphate, and adenosine-monophosphate, and among all pathways enriched by the downregulated differential metabolites, the largest number of pathways were enriched by three differential metabolites, L-isoleucine, xanthine, and arachidonic acid. Conclusion: Untargeted metabolomic analysis of saliva samples from pregnant women with GDM, HPW, and HNPW identified nine differential metabolites with high confidence. The results are similar to findings from previous metabolomics studies of serum and urine samples, which offer the possibility of using saliva for regular noninvasive testing in the population of pregnant women with and without GDM. Meanwhile, the associations between these identified differential metabolites and gingivitis need to be further validated by subsequent studies.

Effects of topical fluoride application on oral microbiota in young children with severe dental caries.

While the effect of fluoride on severe early childhood caries (S-ECC) is clear, knowledge of how it influences the oral microbiota and the consequential effects on oral health is limited. In this cohort study, we investigated the changes introduced in the oral ecosystem before and after using fluoride varnish in 54- to 66-month-old individuals (n=90: 18 children were sampled at 5 different time points). 16S rDNA was amplified from bacterial samples using polymerase chain reaction, and high-throughput sequencing was performed using Illumina MiSeq platforms. Many pronounced microbial changes were related to the effects of fluoride varnishing. The health-associated Bacteroides and Uncultured_bacterium_f_Enterobacteriaceae were enriched in the saliva microbiome following treatment with fluoride varnishing. Co-occurrence network analysis of the dominant genera showed that different groups clearly showed different bacterial correlations. The PICRUSt algorithm was used to predict the function of the microbial communities from saliva samples. The results showed that starch and sucrose metabolism was greater after fluoride use. BugBase was used to determine phenotypes present in microbial community samples. The results showed that Haemophilus and Neisseria (phylum Proteobacteria) was greater before fluoride use. We conclude that the changes in oral microbiology play a role in fluoride prevention of S-ECC.

Untargeted metabolomics of saliva in caries-active and caries-free children in the mixed dentition.

Objective: To compare the differences in salivary metabolites between caries-active and caries-free children in the mixed dentition, and explore their correlation with caries status. Methods: The study involved 20 children (aged 8-9 years) in the mixed dentition, including 10 caries-active (aged 8.6 ± 0.49years) and 10 caries-free children(aged 8.5 ± 0.5years), with a male/female ratio of 1:1. The saliva samples were collected from all children. Metabolite extraction, LC-MS/MS-based untargeted metabolomics, qualitative and semi-quantitative analysis and bioinformatics analysis were performed to identify differential metabolites between the two sample groups. The differential metabolites identified were further analyzed in an attempt to find their correlations with caries status. Results: In the positive ion mode, a total of 1606 molecular features were detected in the samples of the two groups, 189 of which were differential metabolites when comparing the caries-active group with the caries-free group, including 104 up-regulated and 85 down-regulated metabolites. In the negative ion mode, a total of 532 molecular features were detected in the samples of two groups, 70 of which were differential metabolites when comparing the caries-active group with the caries-free group, including 37 up-regulated and 33 down-regulated metabolites. In the positive ion mode, two of the top 5 up-regulated differential metabolites were found in and annotated to specific metabolic pathways, whereas in the negative ion mode, only one of the top 5 up-regulated differential metabolites was found in and annotated to specific metabolic pathways. In both the positive and negative ion modes, the top 5 down-regulated differential metabolites were both annotated to the metabolic pathways. KEGG pathway enrichment analysis of differential metabolites showed that histamine and arachidonic acid identified in the positive ion mode, as well as succinate and L-histidine identified in the negative ion mode were enriched in the top 3 significantly altered pathways. Conclusion: The enriched differential metabolites including histamine, L-histidine and succinate were correlated with the presence of dental caries, but their role in the caries process needs to be further investigated.

Observation of dressed odd-order multi-wave mixing in five-level atomic medium.

By selectively blocking specific laser beams, we investigate coexisting seven distinguishable dressed odd-order multi-wave mixing (MWM) signals in a K-type five-level atomic system. We demonstrate that the enhancement and suppression of dressed four-wave mixing (FWM) signal can be directly detected by scanning the dressing field instead of the probe field. We also study the temporal and spatial interference between two FWM signals. Surprisingly, the pure-suppression of six-wave mixing signal has been shifted far away from resonance by atomic velocity component. Moreover, the interactions among six MWM signals have been studied.

Efficacy of a desensitizing toothpaste containing arginine and calcium carbonate on dentin surface pore structure and dentin morphology.

PURPOSE: To investigate the laboratory changes in dentin tubule occlusion morphology during short term use of desensitizing products as evaluated by electron microscopy and an image analysis. METHODS: Freshly extracted human third molar teeth were collected at random and 40 dentin discs were prepared. These dentin samples were then divided in to four groups (n=10). The test treatment consisted of undiluted Colgate Sensitive Pro-Relief Toothpaste containing 8.0% arginine and calcium carbonate that was applied on the dentin surface under a brushing cycle of 200 strokes, 2 times/day, for 10 days and then soaked in the filtrated human saliva. The two other test products were a commercial toothpaste, Sensodyne Original, containing 10% strontium chloride and a professional re-mineralizing treatment paste (GC Tooth Mousse). The negative control group was soaked in human saliva that had been sterilized by filtration. The occluding ability of the dentin tubules, using the dentin disc model, was evaluated using scanning electron microscopy (SEM). The degree of occlusion of the dentin tubules was quantified using an image analyzer and the results were analyzed by ANOVA and a Tukey's test. RESULTS: All test products created a smear layer on the dentin surface that significantly reduced the diameter of dentin tubules after treatment. Compared to the dentin tubule area on disks treated with the negative control (72.02 +/- 7.23 microm2), disks treated with Colgate Sensitive Pro-Relief, Sensodyne Original, and GC Mousse had dentin tubule areas of 2.10 +/- 0.42 microm2, 10.11 +/- 2.83 microm2, and 30.40 +/- 4.04 microm2 respectively. These differences were statistically significant.

Transient receptor potential vanilloid type-1 regulates periodontal disease damage via the PI3K/AKT signaling pathway.

Objectives: This study aimed to investigate the function of transient receptor potential vanilloid 1 (TRPV1) in regulating periodontal lesions. In addition, we explored the underlying mechanism of the phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT) pathway. Materials and Methods: Lipopolysaccharide (LPS) stimulation of human periodontal ligament cells (HPDLCs) was used to construct a periodontitis cell model, and experimental periodontitis (EP) rats were established by ligation. The mechanism by which TRPV1 regulates periodontitis was further verified by injecting the TRPV1 agonist capsaicin (CPS) and antagonist capsazepine (CPZ) into the gingiva of rats; the alveolar bone losses in each group were measured by stereomicroscopy. Real-time quantitative polymerase chain reaction (qRT-PCR) and Western blotting (WB) were used to research the expression of TRPV1 and proinflammatory cytokines, and WB was performed to test the phosphorylation of PI3K and AKT. Results: In vitro experiments showed that LPS induced the upregulation of TRPV1 and proinflammatory cytokines and promoted the phosphorylation of PI3K and AKT proteins in HPDLCs, which was consistent with their expression in the rat periodontitis model. Moreover, in vivo studies indicated that CPZ had anti-inflammatory effects through the PI3K/AKT pathway and inhibited bone loss induced by periodontal ligation in rats, while CPS had the opposite effect. Conclusion: TRPV1 was involved in the process of alveolar bone defects and the inflammatory response in rats with periodontitis induced by ligation. Its mechanism might be related to the phosphorylation of related proteins in the PI3K/AKT signaling pathway.

Upregulation of TACAN in the trigeminal ganglion affects pain transduction in acute pulpitis.

OBJECTIVE: Acute pulpitis is one of the common causes of tooth pain. TACAN (Tmem120a) is a newly identified ion channel that senses mechanical pain. In this experiment, we studied the expression of the TACAN ion channel in the trigeminal ganglia in a rat model of pulpitis to explore the correlation between the expression of this ion channel and inflammatory pain. DESIGN: Lipopolysaccharide was used to induce acute pulpitis in rats, and pulpitis was assessed histologically. The facial pain threshold of the rats was measured by the von Frey test. TACAN mRNA expression in rat dental pulp and the trigeminal nerve was measured by qPCR, and TACAN protein expression in the trigeminal ganglia was evaluated by western blot analysis and immunofluorescence. Antisense oligonucleotides were used to reduce TACAN protein expression in the trigeminal ganglia, and the change in the pain threshold in the rats with acute pulpitis was determined. RESULTS: The results showed that the TACAN transcript level in rat pulp tissue increased under inflammatory conditions, and we proved that pulpitis increased TACAN protein expression in the rat ipsilateral trigeminal ganglia. The facial pain threshold was decreased in rats with pulpitis. A short-term decrease in TACAN protein expression could improve the pain threshold. CONCLUSIONS: With the development of pulpitis after bacterial infection, the upregulation of TACAN expression in the trigeminal ganglia promoted pain sensitivity. A short-term reduction in TACAN expression relieved pain. Therefore, this study indicated that TACAN is a potential target channel for new analgesics.