Effects of Kv1.3 knockout on pyramidal neuron excitability and synaptic plasticity in piriform cortex of mice.

Kv1.3 belongs to the voltage-gated potassium (Kv) channel family, which is widely expressed in the central nervous system and associated with a variety of neuropsychiatric disorders. Kv1.3 is highly expressed in the olfactory bulb and piriform cortex and involved in the process of odor perception and nutrient metabolism in animals. Previous studies have explored the function of Kv1.3 in olfactory bulb, while the role of Kv1.3 in piriform cortex was less known. In this study, we investigated the neuronal changes of piriform cortex and feeding behavior after smell stimulation, thus revealing a link between the olfactory sensation and body weight in Kv1.3 KO mice. Coronal slices including the anterior piriform cortex were prepared, whole-cell recording and Ca2+ imaging of pyramidal neurons were conducted. We showed that the firing frequency evoked by depolarization pulses and Ca2+ influx evoked by high K+ solution were significantly increased in pyramidal neurons of Kv1.3 knockout (KO) mice compared to WT mice. Western blotting and immunofluorescence analyses revealed that the downstream signaling molecules CaMKII and PKCα were activated in piriform cortex of Kv1.3 KO mice. Pyramidal neurons in Kv1.3 KO mice exhibited significantly reduced paired-pulse ratio and increased presynaptic Cav2.1 expression, proving that the presynaptic vesicle release might be elevated by Ca2+ influx. Using Golgi staining, we found significantly increased dendritic spine density of pyramidal neurons in Kv1.3 KO mice, supporting the stronger postsynaptic responses in these neurons. In olfactory recognition and feeding behavior tests, we showed that Kv1.3 conditional knockout or cannula injection of 5-(4-phenoxybutoxy) psoralen, a Kv1.3 channel blocker, in piriform cortex both elevated the olfactory recognition index and altered the feeding behavior in mice. In summary, Kv1.3 is a key molecule in regulating neuronal activity of the piriform cortex, which may lay a foundation for the treatment of diseases related to piriform cortex and olfactory detection.

Enrichment of Trypsin Inhibitor from Soybean Whey Wastewater Using Different Precipitating Agents and Analysis of Their Properties.

Recovering valuable active substances from the by-products of agricultural processing is a crucial concern for scientific researchers. This paper focuses on the enrichment of soybean trypsin inhibitor (STI) from soybean whey wastewater using either ammonium sulfate salting or ethanol precipitation, and discusses their physicochemical properties. The results show that at a 60% ethanol content, the yield of STI was 3.983 mg/mL, whereas the yield was 3.833 mg/mL at 60% ammonium sulfate saturation. The inhibitory activity of STI obtained by ammonium sulfate salting out (A-STI) was higher than that obtained by ethanol precipitation (E-STI). A-STI exhibited better solubility than E-STI at specific temperatures and pH levels, as confirmed by turbidity and surface hydrophobicity measurements. Thermal characterization revealed that both A-STI and E-STI showed thermal transition temperatures above 90 °C. Scanning electron microscopy demonstrated that A-STI had a smooth surface with fewer pores, while E-STI had a rough surface with more pores. In conclusion, there was no significant difference in the yield of A-STI and E-STI (p < 0.05); however, the physicochemical properties of A-STI were superior to those of E-STI, making it more suitable for further processing and utilization. This study provides a theoretical reference for the enrichment of STI from soybean whey wastewater.

Establishment of a 3D esthetic analysis workflow on 3D virtual patient and preliminary evaluation.

BACKGROUND: In esthetic dentistry, a thorough esthetic analysis holds significant role in both diagnosing diseases and designing treatment plans. This study established a 3D esthetic analysis workflow based on 3D facial and dental models, and aimed to provide an imperative foundation for the artificial intelligent 3D analysis in future esthetic dentistry. METHODS: The established 3D esthetic analysis workflow includes the following steps: 1) key point detection, 2) coordinate system redetermination and 3) esthetic parameter calculation. The accuracy and reproducibility of this established workflow were evaluated by a self-controlled experiment (n = 15) in which 2D esthetic analysis and direct measurement were taken as control. Measurement differences between 3D and 2D analysis were evaluated with paired t-tests. RESULTS: 3D esthetic analysis demonstrated high consistency and reliability (0.973 < ICC < 1.000). Compared with 2D measurements, the results from 3D esthetic measurements were closer to direct measurements regarding tooth-related esthetic parameters (P<0.05). CONCLUSIONS: The 3D esthetic analysis workflow established for 3D virtual patients demonstrated a high level of consistency and reliability, better than 2D measurements in the precision of tooth-related parameter analysis. These findings indicate a highly promising outlook for achieving an objective, precise, and efficient esthetic analysis in the future, which is expected to result in a more streamlined and user-friendly digital design process. This study was registered with the Ethics Committee of Peking University School of Stomatology in September 2021 with the registration number PKUSSIRB-202168136.

Clinical evaluation of a one-piece polyetheretherketone removable partial denture fabricated using a novel digital workflow: A self-controlled clinical trial.

PURPOSE: To explore the clinical application of one-piece polyetheretherketone (PEEK) removable partial dentures (RPDs) fabricated using a novel digital workflow and to evaluate their weights and fits in vivo and patient satisfaction. MATERIALS AND METHODS: Fifteen cases with posterior partially edentulous situations were selected, and each patient received two types of RPDs, including a novel digital workflow (test group) and a conventional workflow (control group). For the test group, one-piece RPDs were designed through three-dimensional (3D) methods by scanning stone casts and fabricated by milling PEEK discs. Each RPD was weighed. The gaps between the oral tissue and RPDs in each group were duplicated using a polyvinylsiloxane (PVS) replica and measured by 3D analysis. A visual analog scale (VAS) was used to evaluate the patient's satisfaction. Paired t-tests were used to compare the differences in the weight, the gaps of each RPD, and VAS values between the two groups. One-way analysis of variance tests was used to compare the differences in the gap among different components in each group. RESULTS: The RPD in the test group weighed less than that in the control group (p < 0.01). No statistically significant differences in the gaps of denture bases and rests (p > 0.05) were found between the two groups, but the gaps of major connectors in the test group were significantly smaller than in the control group (p < 0.05). The VAS scores for comfortableness and masticatory efficiency were not significantly different between the two groups (p > 0.05) but the scores for the aesthetic appearance of the clasps in the test group were significantly higher than that in the control group (p < 0.05). CONCLUSIONS: One-piece PEEK RPDs manufactured using a novel digital workflow weighed less than conventional RPDs and exhibited a clinically acceptable internal fit. Although the aesthetic appearance of the PEEK clasps was superior to the control, there is still room for improvement.

Template-aided and freehand guiding plane preparation for removable partial dentures: A randomized controlled trial.

PURPOSE: To evaluate the accuracy of guiding plane preparation for removable partial dentures (RPDs) using 3D-printed templates compared to the freehand method. MATERIALS AND METHODS: Twenty partially edentulous patients requiring RPDs were randomly divided into two groups: the template-aided group (n = 10) and the freehand group (n = 10). Fifty-six guiding planes were prepared by a single clinician using two different methods. The angle deviation between the prepared guiding plane and the RPD path of placement was measured for both groups. The 3D deviations between the prepared guiding plane and the designed guiding plane were measured for the template-aided group. Patient satisfaction with the RPD was evaluated 2 weeks post-RPD wearing. RESULTS: The angular deviation observed in the template-aided group (1.77±1.11 degrees) was significantly lower than that (6.29±4.18 degrees) in the freehand group (p < .001). Additionally, the 3D deviation between the prepared guiding plane and the designed guiding plane of the template-aided group was 106.2±40.9 µm. No significant difference in patient satisfaction scores related to RPD wearing was found between the two groups. CONCLUSIONS: Utilizing the cobalt-chromium (CoCr) alloy template significantly improved the accuracy of guiding plane preparation in the clinic, irrespective of the site of the abutment tooth.

THE ACCURACY OF INTRAORAL SCAN IN OBTAINING DIGITAL IMPRESSIONS OF EDENTULOUS ARCHES: A SYSTEMATIC REVIEW.

OBJECTIVES: Accuracy is a crucial factor when assessing the quality of digital impressions. This systematic review aims to assess the accuracy of intraoral scan (IOS) in obtaining digital impressions of edentulous jaws. METHODS: This systematic review adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and was registered in the International Prospective Register of Systematic Reviews (PROSPERO ID: CRD42022382983). A thorough retrieval of 7 electronic databases was undertaken, encompassing MEDLINE (PubMed), Web of Science, EMBASE, Scopus, Cochrane Library, Virtual Health Library, and Open gray, through September 11, 2023. A snowball search was performed by tracing the reference lists of the included studies. The Population, Intervention, Comparison, and Outcome (PICO) question of this systematic review was: "What is the accuracy of intraoral scan in obtaining digital impressions of edentulous arches?" The Modified Methodological Index for Nonrandomized Studies (MINORS) was employed to assess the risk of bias. RESULTS: Among the studies retrieved from databases and manual search, a total of 25 studies were selected for inclusion in this systematic review, including 9 in vivo and 16 in vitro studies. Twenty-one of the included studies utilized the 3D deviation analysis method, while 4 studies employed the linear or angular deviation analysis method. The accuracy results of in vitro studies indicated a trueness range of 20-600 µm and a precision range of 2-700 µm. Results of in vivo studies indicated a trueness range of 40-1380 µm, while the precision results were not reported. CONCLUSION: According to the results of this study, direct digital impressions by IOS cannot replace the conventional impressions of completely edentulous arches in vivo. Edentulous digital impressions by IOS demonstrated poor accuracy in peripheral areas with mobile tissues, such as the soft palate, vestibular sulcus, and sublingual area.

Licochalcone Mediates the Pain Relief by Targeting the Voltage-Gated Sodium Channel.

Licorice is a traditional Chinese medicine and recorded to have pain relief effects in national pharmacopoeia, but the mechanisms behind these effects have not been fully explored. Among the hundreds of compounds in licorice, licochalcone A (LCA) and licochalcone B (LCB) are two important components belonging to the chalcone family. In this study, we compared the analgesic effects of these two licochalcones and the molecular mechanisms. LCA and LCB were applied in cultured dorsal root ganglion (DRG) neurons, and the voltage-gated sodium (NaV) currents and action potentials were recorded. The electrophysiological experiments showed that LCA can inhibit NaV currents and dampen excitabilities of DRG neurons, whereas LCB did not show inhibition effect on NaV currents. Because the NaV1.7 channel can modulate Subthreshold membrane potential oscillations in DRG neuron, which can palliate neuropathic pain, HEK293T cells were transfected with NaV1.7 channel and recorded with whole-cell patch clamp. LCA can also inhibit NaV1.7 channels exogenously expressed in HEK293T cells. We further explored the analgesic effects of LCA and LCB on formalin-induced pain animal models. The animal behavior tests revealed that LCA can inhibit the pain responses during phase 1 and phase 2 of formalin test, and LCB can inhibit the pain responses during phase 2. The differences of the effects on NaV currents between LCA and LCB provide us with the basis for developing NaV channel inhibitors, and the novel findings of analgesic effects indicate that licochalcones can be developed into effective analgesic medicines. SIGNIFICANCE STATEMENT: This study found that licochalcone A (LCA) can inhibit voltage-gated sodium (NaV) currents, dampen excitabilities of dorsal root ganglion neurons, and inhibit the NaV1.7 channels exogenously expressed in HEK293T cells. Animal behavior tests showed that LCA can inhibit the pain responses during phase 1 and phase 2 of formalin test, whereas licochalcone B can inhibit the pain responses during phase 2. These findings indicate that licochalcones could be the leading compounds for developing NaV channel inhibitors and effective analgesic medicines.

CDC20 promotes bone formation via APC/C dependent ubiquitination and degradation of p65.

The E3 ubiquitin ligase complex CDC20-activated anaphase-promoting complex/Cyclosome (APC/CCDC20 ) plays a critical role in governing mitotic progression by targeting key cell cycle regulators for degradation. Cell division cycle protein 20 homolog (CDC20), the co-activator of APC/C, is required for full ubiquitin ligase activity. In addition to its well-known cell cycle-related functions, we demonstrate that CDC20 plays an essential role in osteogenic commitment of bone marrow mesenchymal stromal/stem cells (BMSCs). Cdc20 conditional knockout mice exhibit decreased bone formation and impaired bone regeneration after injury. Mechanistically, we discovered a functional interaction between the WD40 domain of CDC20 and the DNA-binding domain of p65. Moreover, CDC20 promotes the ubiquitination and degradation of p65 in an APC11-dependent manner. More importantly, knockdown of p65 rescues the bone loss in Cdc20 conditional knockout mice. Our current work reveals a cell cycle-independent function of CDC20, establishes APC11CDC20 as a pivotal regulator for bone formation by governing the ubiquitination and degradation of p65, and may pave the way for treatment of bone-related diseases.

A double-blind randomized within-subject study to evaluate clinical applicability of four digital workflows for the fabrication of posterior single implant crown.

OBJECTIVE: To compare efficiency and clinical efficacy of posterior single implant crowns (PSIC) fabricated using four digital workflows. MATERIALS AND METHODS: Twenty-two patients with one missing first molar were included. Each patient received four screw-retained implant crowns fabricated through four different workflows including a fully digital workflow with immediate digital impression (Group i-IOS), a fully digital workflow with digital impression after implant osseointegration (Group d-IOS), a model-based hybrid workflow using immediate analogue impression (Group i-AI), and a model-based hybrid workflow with conventional analogue impression after implant osseointegration (Group d-AI). The crown delivery sequence was randomized and blinded. The efficiency for each workflow and clinical outcome of each crown were recorded. RESULTS: The average clinical working time in fully digital workflows (i-IOS 46.90 min, d-IOS 45.66 min) was significantly lower than that in the hybrid workflows (i-AI 54.59 min, d-AI 55.96 min; p < .001). Significantly more laboratory time was spent in hybrid workflows (i-AI 839.60 min, d-AI 811.73 min) as compared to fully digital workflows (i-IOS 606.25 min, d-IOS 607.83 min, p < .01). No significant differences in the chairside time at delivery were found. More crowns in Group i-AI (15%) needed additional laboratory interventions than in the other groups (p = .029). CONCLUSION: Digital impression and model-free fully digital workflow improved prosthetic efficiency in the fabrication of PSIC. With the limitation that the results were only applicable to the implant system used and the digital technologies applied, findings suggested that workflows integrating immediate impression with implant surgery procedure was clinically applicable for restoration of PSIC.

Effect of a novel interocclusal recording method on occlusal accuracy of implant-supported fixed prostheses: A randomized clinical trial.

OBJECTIVES: To investigate the effect of a novel interocclusal recording method on the occlusal accuracy of implant-supported fixed prostheses for partially dentate patients with distal extension. MATERIALS AND METHODS: Twenty patients with two or more adjacent teeth missing in the distal extension and scheduled to receive implant-supported fixed prostheses were enrolled. Two interocclusal recording methods were used: placing polyvinyl siloxane (PVS) on the interocclusal recording caps (test), and placing PVS on healing abutments (control). The intraoral occlusal contacts in maximal intercuspal position (MIP) were compared with those in the mounted casts to calculate sensitivity and positive predictive value (PPV). Then, patients were randomly allocated into two groups to determine which interocclusal record would be used. The implant prostheses' evaluations mainly included occlusal adjustment height, volume, and time, occlusal contact score based on articulating paper examination. Paired-samples t-test, Mann-Whitney U test, and least squares regression analyzed the statistic differences. RESULTS: The test method had higher sensitivity to detect intraoral occlusal contacts than the control method (p = .002), but similar PPV (p = .10). During the prostheses' evaluations, the occlusal adjustment height in the test group was significantly lower than that in the control group [99.4 (53.2, 134.2) vs. 159.0 (82.3, 247.8) µm, p = .03], while the occlusal contact score before adjustment was higher (p = .006). The groups had similar occlusal adjustment volume and time. CONCLUSIONS: The novel interocclusal recording method for implant-supported fixed prostheses was more accurate and could reduce the occlusal adjustment.

Comparison of the dimensional and morphological accuracy of three-dimensional digital dental casts digitized using different methods.

The purpose of this study was to compare the accuracy of digital dental casts from plaster cast scanning (PCS), impression scanning (IPS), intraoral scanning (IOS), and cone-beam computed tomography (CBCT) scanning (CCS) methods. The maxillary and mandibular dental casts of 15 patients who needed CBCT scans for oral examination or treatment were digitized via four methods. 12 linear distance measurements of all digital dental casts were selected and acquired with software and compared to those of the reference plaster cast to evaluate the dimensional accuracy. Three-dimensional deviation analysis of the IPS, IOS and CCS groups with respect to the reference PCS group was performed to evaluate the morphological accuracy. The discrepancy in linear distances between the digital dental casts and reference plaster casts was statistically significant (p < 0.01). The dimensional accuracies of the PCS (0.06 ± 0.12 mm) and IPS (0.03 ± 0.05 mm) casts were better than those of the IOS (0.37 ± 0.30 mm) and CCS (0.54 ± 0.40 mm) casts. The one-sample t test showed that there were statistically significant differences between the discrepancies in 8 of the linear distances for the PCS group and 9 of the linear distances for the IPS group between the digital dental casts and reference plaster casts, with an ideal error of 0.00 (p < 0.05). The sequence of morphological accuracy from good to poor was maxillary and mandibular IPS, mandibular IOS; maxillary IOS; and maxillary and mandibular CCS. The accuracy of the digital dental casts from the PCS and IPS methods was greater than that of IOS and CCS methods. Although accuracy of the digital dental cast from IOS was low, it satisfied the clinical requirements for fixed restorations in small units. The accuracy of the digital dental cast from CCS was poorest and could only be used for procedures with lower accuracy requirements.

Integrative Analysis Reveals the Diverse Effects of 3D Stiffness upon Stem Cell Fate.

The origin of life and native tissue development are dependent on the heterogeneity of pluripotent stem cells. Bone marrow mesenchymal stem cells (BMMSCs) are located in a complicated niche with variable matrix stiffnesses, resulting in divergent stem cell fates. However, how stiffness drives stem cell fate remains unknown. For this study, we performed whole-gene transcriptomics and precise untargeted metabolomics sequencing to elucidate the complex interaction network of stem cell transcriptional and metabolic signals in extracellular matrices (ECMs) with different stiffnesses, and we propose a potential mechanism involved in stem cell fate decision. In a stiff (39~45 kPa) ECM, biosynthesis of aminoacyl-tRNA was up-regulated, and increased osteogenesis was also observed. In a soft (7~10 kPa) ECM, biosynthesis of unsaturated fatty acids and deposition of glycosaminoglycans were increased, accompanied by enhanced adipogenic/chondrogenic differentiation of BMMSCs. In addition, a panel of genes responding to the stiffness of the ECM were validated in vitro, mapping out the key signaling network that regulates stem cells' fate decisions. This finding of "stiffness-dependent manipulation of stem cell fate" provides a novel molecular biological basis for development of potential therapeutic targets within tissue engineering, from both a cellular metabolic and a biomechanical perspective.

ZIM1 Combined with Hydrogel Inhibits Senescence of Primary PαS Cells during In Vitro Expansion.

Bone marrow stem cells (BMSCs) are a promising source of seed cells in bone tissue engineering, which needs a great quantity of cells. Cell senescence occurs as they are passaged, which could affect the therapeutic effects of cells. Therefore, this study aims to explore the transcriptomic differences among the uncultured and passaged cells, finding a practical target gene for anti-aging. We sorted PαS (PDGFR-α+SCA-1+CD45-TER119-) cells as BMSCs by flow cytometry analysis. The changes in cellular senescence phenotype (Counting Kit-8 (CCK-8) assay, reactive oxygen species (ROS) test, senescence-associated ß-galactosidase (SA-ß-Gal) activity staining, expression of aging-related genes, telomere-related changes and in vivo differentiation potential) and associated transcriptional alterations during three important cell culture processes (in vivo, first adherence in vitro, first passage, and serial passage in vitro) were studied. Overexpression plasmids of potential target genes were made and examed. Gelatin methacryloyl (GelMA) was applied to explore the anti-aging effects combined with the target gene. Aging-related genes and ROS levels increased, telomerase activity and average telomere length decreased, and SA-ß-Gal activities increased as cells were passaged. RNA-seq offered that imprinted zinc-finger gene 1 (Zim1) played a critical role in anti-aging during cell culture. Further, Zim1 combined with GelMA reduced the expression of P16/P53 and ROS levels with doubled telomerase activities. Few SA-ß-Gal positive cells were found in the above state. These effects are achieved at least by the activation of Wnt/ß-catenin signaling through the regulation of Wnt2. The combined application of Zim1 and hydrogel could inhibit the senescence of BMSCs during in vitro expansion, which may benefit clinical application.

Preliminary application and evaluation of digital step-by-step tooth-preparation templates.

STATEMENT OF PROBLEM: Tooth preparation is a fundamental technique, and inaccurate preparation may lead to excessive irreversible tooth removal or insufficient restorative space. The conventional process depends mostly on operator experience, and variable quality is inevitable. Whether a tooth preparation template would be beneficial, especially for inexperienced dentists, is unclear. PURPOSE: The purpose of this preliminary study was to evaluate the application of new digitally designed step-by-step templates to guide tooth preparation. MATERIAL AND METHODS: A laboratory scanner was used to obtain digital scans of dental casts. A 3-dimensional reverse engineering software program was used for the step-by-step digital design. The data for a series of guide templates were imported into a computer-aided manufacturing (CAM) machine for milling. Ten experts and 10 inexperienced dentists prepared teeth on a dentoform in a mannequin head. They were instructed to complete the preparation within 20 minutes both with and without the step-by-step template. The prepared crowns were subsequently scanned with an intraoral scanner, the scans were imported into a preparation evaluation software program, and various indexes were scored. The t test was used to analyze the differences between the 2 methods of tooth preparation in each group (α=.05). RESULTS: No significant differences were found in total scores with and without the guide templates in the expert group (P=.256), but the scores in the inexperienced group differed significantly between the 2 preparation methods (P<.001). In undercut comparisons, the 2 methods of preparation did not differ significantly in the expert (P=.912) or inexperienced groups (P=.601). However, the scores for taper and occlusal reduction were significantly higher in the inexperienced group when using the guide template (P<.001). CONCLUSIONS: The new digitally designed step-by-step tooth preparation guide template significantly improved the efficiency and quality of tooth preparation for inexperienced dentists when preparing multiple teeth.

Accuracy of two best-fit alignment strategies with different reference areas for wear measurement with an intraoral scanner: an in vitro study.

AIM: The aim of the present in vitro study was to assess and compare the accuracy of two best-fit alignment strategies with different reference areas for wear measurement with an intraoral scanner (IOS). MATERIALS AND METHODS: Eight anatomic contour zirconia crowns were fabricated and scanned twice with an IOS. One of the scan datasets (Data Trueness) was duplicated and wear facets were simulated (Data Wear). The other scan dataset (Data Baseline) was aligned to Data Wear by two best-fit alignment strategies with different reference areas (the occlusal surface with no signs of wear [Group Occlusal], and the axial surface [Group Axial]), and 3D deviation analysis was performed to detect wear loss. The 3D deviation between Data Trueness and Data Wear was calculated as the truth-value for accuracy evaluation (Group Trueness). RESULTS: The color-difference map showed Group Occlusal had a similar wear-facet distribution to Group Trueness while Group Axial showed an obvious tilting position, and the obtained height loss values were larger and with large standard deviations. Both Group Occlusal and Group Axial showed significant differences compared with Group Trueness in maximum height loss and mean height loss (P < 0.05) while showed no significant difference in mean distance (P > 0.05). The paired t test showed significant differences between Group Occlusal and Group Axial in maximum height loss and mean height loss (P < 0.05) while showed no significant difference in mean distance (P > 0.05). CONCLUSIONS: Best-fit alignment with the occlusal reference area produced a better alignment result than that with the axial reference area. Measuring wear with an IOS has potential, but the method is prone to overestimating the height loss.

A three-dimensional printed assembled sleeveless guide system for fiber-post removal.

This report describes a technique to develop a three-dimensional printed assembled sleeveless guide system to aid the fiber-post removal in a safe and efficient way. The surface and volume data of the dentition containing the targeted tooth were acquired with optical scanners and cone-beam computed tomography. The virtual path of the fiber-post removal was determined and integrated with a guide prototype with a cylindrical passage. The prototype data was split into two separate parts, combined with the matched pin and jack structures to facilitate the assembly. A guide tube was generated based on the axis of the cylindrical passage, split into three units, and combined with the previously processed data with connectors to form the finalized guide system. The adaptor for the head of handpiece was designed to facilitate the guidance. All the finalized data were printed with titanium alloy. The fiber-post of the upper right central incisor was successfully removed with the aid of this assembled sleeveless guide system that guides the handpiece rather than the rotary instrument.

The accuracies of three intraoral scanners with regard to shade determination: An in vitro study.

PURPOSE: To compare the accuracies of three intraoral scanners for shade determination function in vitro, and to preliminarily investigate the shade-matching characteristics of the three intraoral scanners. MATERIALS AND METHODS: The shade of the middle third region of each shade tab on the Vita Classical A1-D4 shade guide (VC) was measured with a spectrophotometer (Vita Easyshade V, VE) and three intraoral scanners, including CEREC Omnicam (OM), 3Shape TRIOS 3 (T3), and TRIOS 4 (T4). A conversion table between VC values and CIELAB values was established from the database of VE to analyze the trueness. The reproducibility of the instruments was then compared by repeating the measurements five times. RESULTS: The mean color difference for each instrument was highest in the OM, followed by the T4, and lowest in the T3 and VE, respectively. The L* and a* value for OM, and the b* value for T4, were significantly different from those for VE (p <0.05). The reproducibility of the instrument was highest in the VE (Fleiss' kappa: 0.95), followed by the T3 (Fleiss' kappa: 0.89), T4 (Fleiss' kappa: 0.87), and OM (Fleiss' kappa: 0.78). CONCLUSIONS: Of the three intraoral scanners, the trueness was best on the T3. The reproducibility of all the instruments was excellent.

Mechanisms Underlying the Inhibition of KV1.3 Channel by Scorpion Toxin ImKTX58.

Voltage-gated KV1.3 channel has been reported to be a drug target for the treatment of autoimmune diseases, and specific inhibitors of Kv1.3 are potential therapeutic drugs for multiple diseases. The scorpions could produce various bioactive peptides that could inhibit KV1.3 channel. Here, we identified a new scorpion toxin polypeptide gene ImKTX58 from the venom gland cDNA library of the Chinese scorpion Isometrus maculatus Sequence alignment revealed high similarities between ImKTX58 mature peptide and previously reported KV1.3 channel blockers-LmKTX10 and ImKTX88-suggesting that ImKTX58 peptide might also be a KV1.3 channel blocker. By using electrophysiological recordings, we showed that recombinant ImKTX58 prepared by genetic engineering technologies had a highly selective inhibiting effect on KV1.3 channel. Further alanine scanning mutagenesis and computer simulation identified four amino acid residues in ImKTX58 peptide as key binding sites to KV1.3 channel by forming hydrogen bonds, salt bonds, and hydrophobic interactions. Among these four residues, 28th lysine of the ImKTX58 mature peptide was found to be the most critical amino acid residue for blocking KV1.3 channel. SIGNIFICANCE STATEMENT: In this study, we discovered a scorpion toxin gene ImKTX58 that has not been reported before in Hainan Isometrus maculatus and successfully used the prokaryotic expression system to express and purify the polypeptides encoded by this gene. Electrophysiological experiments on ImKTX58 showed that ImKTX58 has a highly selective blocking effect on KV1.3 channel over Kv1.1, Kv1.2, Kv1.5, SK2, SK3, and BK channels. These findings provide a theoretical basis for designing highly effective KV1.3 blockers to treat autoimmune and other diseases.

pH Stimuli-Responsive, Rapidly Self-healable Coatings Enhanced the Corrosion Resistance and Osteogenic Differentiation of Mg-1Ca Osteoimplant.

Mg-Ca alloys have emerged as a promising research direction for biomedical implants in the orthopedic field. However, their clinical use is deterred by their fast corrosion rate. In this work, a pH stimuli-responsive silk-halloysite (HNT)/phytic acid (PA) self-healing coating (Silk-HNT/PA) is constructed to slow down the corrosion rate of Mg-1Ca alloy and its cell viability and osteogenic differentiation ability are enhanced. The Silk-HNT/PA coating exhibits appealing active corrosion protection, by eliciting pH-triggerable self-healing effects, while simultaneously affording superior biocompatibility and osteogenic differentiation ability. Moreover, in vivo studies by histological analysis also demonstrate better osseointegration for the Silk-HNT/PA coated Mg-1Ca alloy. In summary, the Silk-HNT/PA coating in the present study has great potential in enhancing the biomedical utility of Mg alloys.

DUSP5 promotes osteogenic differentiation through SCP1/2-dependent phosphorylation of SMAD1.

Dual-specificity phosphatases (DUSPs) are defined by their capability to dephosphorylate both phosphoserine/phosphothreonine (pSer/pThr) and phosphotyrosine (pTyr). DUSP5, a member of DUSPs superfamily, is located in the nucleus and plays crucially regulatory roles in the signaling pathway transduction. In our present study, we discover that DUSP5 significantly promotes osteogenic differentiation of mesenchymal stromal cells (MSCs) by activating SMAD1 signaling pathway. Mechanistically, DUSP5 physically interacts with the phosphatase domain of small C-terminal phosphatase 1/2 (SCP1/2, SMAD1 phosphatases) by the linker region. In addition, we further confirm that DUSP5 activates SMAD1 signaling through a SCP1/2-dependent manner. Specifically, DUSP5 attenuates the SCP1/2-SMAD1 interaction by competitively binding to SCP1/2, which is responsible for the SMAD1 dephosphorylation, and thus results in the activation of SMAD1 signaling. Importantly, DUSP5 expression in mouse bone marrow MSCs is significantly reduced in ovariectomized (OVX) mice in which osteogenesis is highly passive, and overexpression of Dusp5 via tail vein injection reverses the bone loss of OVX mice efficiently. Collectively, this work demonstrates that the linker region of DUSP5 maybe a novel chemically modifiable target for controlling MSCs fate choices and for osteoporosis treatment.