The Highly Conserved Stem-Loop II Motif Is Dispensable for SARS-CoV-2.

The stem-loop II motif (s2m) is an RNA structural element that is found in the 3' untranslated region (UTR) of many RNA viruses, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Though the motif was discovered over 25 years ago, its functional significance is unknown. In order to understand the importance of s2m, we created viruses with deletions or mutations of the s2m by reverse genetics and also evaluated a clinical isolate harboring a unique s2m deletion. Deletion or mutation of the s2m had no effect on growth in vitro or on growth and viral fitness in Syrian hamsters in vivo. We also compared the secondary structure of the 3' UTR of wild-type and s2m deletion viruses using selective 2'-hydroxyl acylation analyzed by primer extension and mutational profiling (SHAPE-MaP) and dimethyl sulfate mutational profiling and sequencing (DMS-MaPseq). These experiments demonstrate that the s2m forms an independent structure and that its deletion does not alter the overall remaining 3'-UTR RNA structure. Together, these findings suggest that s2m is dispensable for SARS-CoV-2. IMPORTANCE RNA viruses, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), contain functional structures to support virus replication, translation, and evasion of the host antiviral immune response. The 3' untranslated region of early isolates of SARS-CoV-2 contained a stem-loop II motif (s2m), which is an RNA structural element that is found in many RNA viruses. This motif was discovered over 25 years ago, but its functional significance is unknown. We created SARS-CoV-2 with deletions or mutations of the s2m and determined the effect of these changes on viral growth in tissue culture and in rodent models of infection. Deletion or mutation of the s2m element had no effect on growth in vitro or on growth and viral fitness in Syrian hamsters in vivo. We also observed no impact of the deletion on other known RNA structures in the same region of the genome. These experiments demonstrate that s2m is dispensable for SARS-CoV-2.

Fluorescence and lasing of neutral nitrogen molecules inside femtosecond laser filaments in air: mechanism and applications.

High power femtosecond laser pulses launched in air undergo nonlinear filamentary propagation, featuring a bright and thin plasma channel in air with its length much longer than the Rayleigh length of the laser beam. During this nonlinear propagation process, the laser pulses experience rich and complex spatial and temporal transformations. With its applications ranging from supercontinuum generation, laser pulse compression, remote sensing to triggering of lightning, the underlying physical mechanism of filamentation has been intensively studied. In this review, we will focus on the fluorescence and cavity-free lasing effect of the plasma filaments in air. The different mechanisms underlying the fluorescence of the excited neutral nitrogen molecules will be throughly examined and it is concluded that the electron collision excitation is the dominant channel for the formation of the excited nitrogen molecules. The recently discovered "air lasing" effect, a cavity-free bidirectional lasing emission emitted by the filaments, will be introduced and its main properties will be emphasized. The applications of the fluorescence and lasing effect of the neutral nitrogen molecules will be introduced, with two examples on spectroscopy and detection of electric field. Finally, we discuss the quenching effect of the lasing effect in atmosphere and the mechanisms responsible will be analyzed. An outlook for the achievement of backward lasing in air will be briefly presented.

Assessment and evaluation of online education and virtual simulation technology in dental education: a cross-sectional survey.

BACKGROUND: The global outbreak of coronavirus disease (COVID-19) has led medical universities in China to conduct online teaching. This study aimed to assess the effectiveness of a blended learning approach that combines online teaching and virtual reality technology in dental education and to evaluate the acceptance of the blended learning approach among dental teachers and students. METHODS: The Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) checklist was followed in this study. A total of 157 students' perspectives on online and virtual reality technology education and 54 teachers' opinions on online teaching were collected via questionnaires. Additionally, 101 students in the 2015-year group received the traditional teaching method (TT group), while 97 students in the 2017-year group received blended learning combining online teaching and virtual reality technology (BL group). The graduation examination results of students in the two groups were compared. RESULTS: The questionnaire results showed that most students were satisfied with the online course and the virtual simulation platform teaching, while teachers held conservative and neutral attitudes toward online teaching. Although the theoretical score of the BL group on the final exam was greater than that of the TT group, there was no significant difference between the two groups (P = 0.805). The skill operation score of the BL group on the final exam was significantly lower than that of the TT group (P = 0.004). The overall score of the BL group was lower than that of the TT group (P = 0.018), but the difference was not statistically significant (P = 0.112). CONCLUSIONS: The blended learning approach combining online teaching and virtual reality technology plays a positive role in students' learning and is useful and effective in dental education.

Comprehensive 3-dimensional Positional and Morphological Analyses of Condyle and Glenoid Fossa in Patients with Skeletal Class II Malocclusion following Bimaxillary Orthognathic Surgery.

This study aimed to comprehensively and quantitatively characterize 3-dimensional (3D) positional and morphological changes of the condyle and glenoid fossa in patients with skeletal Class II malocclusion treated with bimaxillary orthognathic surgery. Twenty eligible patients treated at our institution from January 2016 to December 2021 with more than 12 months of postoperative follow-up were retrospectively enrolled. Radiographic data of cone-beam computed tomography (CBCT) for each patient were collected at 3 stages: 1 week preoperatively (T0), immediately after surgery (T1), and at least 12 months postoperatively (T2). Positional changes, surface and volumetric alterations of condyle, and bone remodeling in glenoid fossa were measured and compared based on voxel- and surface registrations in visual 3D methods. Most patients exhibited a tendency for condyles to shift posteriorly, laterally, superiorly, and rotated outward, downward, and forward immediately after surgery. Posterior, medial, superior movement and outward, upward, and backward rotation of condyles were observed during follow-up (T1-T2). Bone resorption frequently occurred in the posterior area of condylar surfaces, while bone remodeling was more common in the anterior region of the glenoid fossa. Reduced volume of the condyle was found in most cases, which was not associated with the amount of mandibular advancement. Overall, the condyle and its corresponding glenoid fossa remained relatively stable during the follow-up. Our results reveal positional and morphological alterations in the condyle and the glenoid fossa after bimaxillary orthognathic surgery in patients with skeletal class II malocclusion. These changes predominantly fall within the spectrum of physical adaption.

Amplification of light pulses with orbital angular momentum (OAM) in nitrogen ions lasing.

Nitrogen ions pumped by intense femtosecond laser pulses give rise to optical amplification in the ultraviolet range. Here, we demonstrated that a seed light pulse carrying orbital angular momentum (OAM) can be significantly amplified in nitrogen plasma excited by a Gaussian femtosecond laser pulse. With the topological charge of ℓ = ±1, we observed an energy amplification of the seed light pulse by two orders of magnitude, while the amplified pulse carries the same OAM as the incident seed pulse. Moreover, we show that a spatial misalignment of the plasma amplifier with the OAM seed beam leads to an amplified emission of Gaussian mode without OAM, due to the special spatial profile of the OAM seed pulse that presents a donut-shaped intensity distribution. Utilizing this misalignment, we can implement an optical switch that toggles the output signal between Gaussian mode and OAM mode. This work not only certifies the phase transfer from the seed light to the amplified signal, but also highlights the important role of spatial overlap of the donut-shaped seed beam with the gain region of the nitrogen plasma for the achievement of OAM beam amplification.

Huntingtin-interacting protein family members have a conserved pro-viral function from Caenorhabditis elegans to humans.

Huntingtin-interacting protein family members are evolutionarily conserved from yeast to humans, and they are known to be key factors in clathrin-mediated endocytosis. Here we identified the Caenorhabditis elegans protein huntingtin-interacting protein-related 1 (HIPR-1) as a host factor essential for Orsay virus infection of C. elegans Ablation of HIPR-1 resulted in a greater than 10,000-fold reduction in viral RNA, which could be rescued by ectopic expression of HIPR-1. Viral RNA replication from an endogenous transgene replicon system was not affected by lack of HIPR-1, suggesting that HIPR-1 plays a role during an early, prereplication virus life-cycle stage. Ectopic expression of HIPR-1 mutants demonstrated that neither the clathrin light chain-binding domain nor the clathrin heavy chain-binding motif were needed for virus infection, whereas the inositol phospholipid-binding and F-actin-binding domains were essential. In human cell culture, deletion of the human HIP orthologs HIP1 and HIP1R led to decreased infection by Coxsackie B3 virus. Finally, ectopic expression of a chimeric HIPR-1 harboring the human HIP1 ANTH (AP180 N-terminal homology) domain rescued Orsay infection in C. elegans, demonstrating conservation of its function through evolution. Collectively, these findings further our knowledge of cellular factors impacting viral infection in C. elegans and humans.

Three-dimensional quantitative changes of condyle in patients with skeletal class III malocclusion after bimaxillary orthognathic surgery with 5-year follow-up.

OBJECTIVE: The present study aimed to characterize three-dimensional (3D) long-term quantitative condyle change including positional, surface, and volumetric alterations in patients with skeletal class III malocclusion treated with bimaxillary orthognathic surgery. MATERIAL AND METHODS: Twenty-three eligible patients (9 males, 14 females, mean age: 28.28 years old) treated from Jan. 2013 to Dec. 2016 with postoperative follow-up over 5 years were retrospectively enrolled. Cone-beam computed tomography scan for each patient was conducted at 4 stages: 1 week preoperatively (T0), immediately after surgery (T1), 12 months postoperatively (T2), and 5-year postoperatively (T3). Positional changes, surface, and volumetric remodeling of condyle were measured in segmented visual 3D models and statistically compared between stages. RESULTS: Our 3D quantitative calibrations revealed that the condylar center shifted in anterior (0.23 ± 1.50 mm), medial (0.34 ± 0.99), and superior (1.11 ± 1.10 mm) directions and rotated outward (1.58 ± 3.11°), superior (1.83 ± 5.08°), and backward (4.79 ± 13.75°) from T1 to T3. With regard to condylar surface remodeling, bone formation was frequently observed in the anteromedial areas, while bone resorption was commonly detected in the anterolateral area. Moreover, condylar volume remained largely stable with a minimal reduction during the follow-up. CONCLUSION: Collectively, although condyle undergoes positional changes and bone remodeling after bimaxillary surgery in patients with mandibular prognathism, these changes largely fall in the range of physical adaptations in the long run. CLINICAL RELEVANCE: These findings advance the current understanding of long-term condylar remodeling after bimaxillary orthognathic surgery in skeletal class III patients.

Clinical validation of an AI-based motion correction reconstruction algorithm in cerebral CT.

OBJECTIVES: To evaluate the clinical performance of an artificial intelligence (AI)-based motion correction (MC) reconstruction algorithm for cerebral CT. METHODS: A total of 53 cases, where motion artifacts were found in the first scan so that an immediate rescan was taken, were retrospectively enrolled. While the rescanned images were reconstructed with a hybrid iterative reconstruction (IR) algorithm (reference group), images of the first scan were reconstructed with both the hybrid IR (motion group) and the MC algorithm (MC group). Image quality was compared in terms of standard deviation (SD), signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), the mean squared error (MSE), peak signal-to-noise ratio (PSNR), structural similarity index (SSIM), and mutual information (MI), as well as subjective scores. The diagnostic performance for each case was evaluated accordingly by lesion detectability or the Alberta Stroke Program Early CT Score (ASPECTS) assessment. RESULTS: Compared with the motion group, the SNR and CNR of the MC group were significantly increased. The MSE, PSNR, SSIM, and MI with respect to the reference group were improved by 44.1%, 15.8%, 7.4%, and 18.3%, respectively (all p < 0.001). Subjective image quality indicators were scored higher for the MC than the motion group (p < 0.05). Improved lesion detectability and higher AUC (0.817 vs 0.614) in the ASPECTS assessment were found for the MC to the motion group. CONCLUSIONS: The AI-based MC reconstruction algorithm has been clinically validated for reducing motion artifacts and improving diagnostic performance of cerebral CT. KEY POINTS: • An artificial intelligence-based motion correction (MC) reconstruction algorithm has been clinically validated in both qualitative and quantitative manner. • The MC algorithm reduces motion artifacts in cerebral CT and increases the diagnostic confidence for brain lesions. • The MC algorithm can help avoiding rescans caused by motion and improving the efficiency of cerebral CT in the emergency department.

Vertical transmission in Caenorhabditis nematodes of RNA molecules encoding a viral RNA-dependent RNA polymerase.

Here, we report on the discovery in Caenorhabditis nematodes of multiple vertically transmitted RNAs coding for putative RNA-dependent RNA polymerases. Their sequences share similarity to distinct RNA viruses, including bunyaviruses, narnaviruses, and sobemoviruses. The sequences are present exclusively as RNA and are not found in DNA form. The RNAs persist in progeny after bleach treatment of adult animals, indicating vertical transmission of the RNAs. We tested one of the infected strains for transmission to an uninfected strain and found that mating of infected animals with uninfected animals resulted in infected progeny. By in situ hybridization, we detected several of these RNAs in the cytoplasm of the male and female germline of the nematode host. The Caenorhabditis hosts were found defective in degrading exogenous double-stranded RNAs, which may explain retention of viral-like RNAs. Strikingly, one strain, QG551, harbored three distinct virus-like RNA elements. Specific patterns of small RNAs complementary to the different viral-like RNAs were observed, suggesting that the different RNAs are differentially recognized by the RNA interference (RNAi) machinery. While vertical transmission of viruses in the family Narnaviridae, which are known as capsidless viruses, has been described in fungi, these observations provide evidence that multicellular animal cells harbor similar viruses.

Comprehensive characterization of epidemiological and 3D radiographic features of non-third molar impacted teeth in a Chinese dental population.

OBJECTIVE: This retrospective study aimed to comprehensively delineate the epidemiological and 3-dimensional radiographic characteristics of non-third molar (non-M3) impacted teeth in a Chinese dental population. MATERIAL AND METHODS: Patients with impacted teeth except for the third molar (ITEM3) were retrospectively screened via cone-beam CT images from 75,021 patients treated at our institution from June 2012 to December 2018. Demographic and clinical data of patients with ITEM3 were retrieved from medical records. CBCT coupled with 3-dimensional reconstruction was employed to characterize the radiographic features of ITEM3. Associations between these epidemiological, clinical, and radiographic features were further statistically analyzed. RESULTS: Among 1975 eligible patients, 2467 ITEM3s were identified with a prevalence of 2.63% (1975/75,021). Females slightly outnumbered males with a ratio of 1.12:1. The majority of ITEM3 was single (1577, 79.85%) in the maxilla. The maxillary canine teeth were the most frequently impacted (52.45%), followed by maxillary incisors. The mesioangular position was the most common orientation (43.8%), followed by vertical and buccal-lingual orientations. The most frequently associated lesion was external root resorption of the adjacent tooth, which was significantly correlated with the morphology and position of the impacted tooth. CONCLUSION: Most ITEM3 was single, mesioangular, found at maxillary canines, sometimes associated with diverse complications. Our data advance the current understanding of ITEM3 and offer insights into the management of this dental abnormality. CLINICAL RELEVANCE: These findings are useful for clinicians to comprehensively understand the prevalence, radiographic features, and complications of non-M3 impacted teeth.

Quantitative sensory testing of mandibular somatosensory function following orthognathic surgery-A pilot study in Chinese with class III malocclusion.

BACKGROUND: Somatosensory changes after sagittal split ramus osteotomy (SSRO) have not been fully studied in Chinese patients by the latest technologies. OBJECTIVE: To provide a comprehensive analysis of somatosensory function at the lower lip and chin at different time points following SSRO in a Chinese population. METHODS: A total of 22 patients (18-27 years; nine men) with skeletal III malocclusion and scheduled for SSRO were recruited. Quantitative sensory testing (QST) was performed at pre-operation (baseline), 1 week (1W), 1, 3 and 6 months (1M, 3M, 6M) post-operatively. Cold detection threshold (CDT), warm detection threshold (WDT), cold pain threshold (CPT), heat pain threshold (HPT), mechanical detection threshold (MDT), mechanical pain threshold (MPT), pressure pain threshold (PPT) and two-point discrimination threshold (2PD) were tested at the lower lip and chin. RESULTS: Except for PPT at both test sides at 1W and 1M, all QST values indicated a significantly reduced sensitivity (p < .05). All values had returned to baseline values at 3M with exception of HPT at the right chin which, however, had recovered at 6M (p > .05). CONCLUSIONS: Somatosensory function at the lower lip and chin appears to be fully recovered in the majority of young Chinese adults 6 months after SSRO for skeletal class III malocclusion.

A CREB1-miR-181a-5p loop regulates the pathophysiologic features of bone marrow stromal cells in fibrous dysplasia of bone.

BACKGROUND: Fibrous dysplasia (FD) is a bone marrow stromal cell (BMSC) disease caused by activating mutations of guanine nucleotide-binding protein alpha-stimulating activity polypeptide (GNAS) and is characterized by increased proliferative activity and disrupted osteogenesis of BMSCs. However, the molecular mechanisms regulating the pathophysiologic features of BMSCs in FD remain unknown. This study aimed to identify and verify the roles of the CREB1-miR-181a-5p regulatory loop in FD pathophysiology. METHODS: MicroRNA (miRNA) sequencing analysis was used to identify the possible miRNAs implicated in FD. The proliferation, apoptosis, and osteogenic differentiation of BMSCs, as well as the osteoclast-induced phenotype, were measured and compared after exogenous miR-181a-5p transfection into FD BMSCs or miR-181a-5p inhibitor transfection into normal BMSCs. Chromatin immunoprecipitation and luciferase reporter assays were performed to verify the interactions between CREB1 and miR-181a-5p and their effects on the FD pathological phenotype. RESULTS: Compared to normal BMSCs, FD BMSCs showed decreased miR-181a-5p levels and exhibited increased proliferative activity, decreased apoptotic capacity, and impaired osteogenesis. FD BMSCs also showed a stronger osteoclast activation effect. miR-181a-5p overexpression reversed the pathophysiologic features of FD BMSCs, whereas miR-181a-5p suppression induced an FD-like phenotype in normal BMSCs. Mechanistically, miR-181a-5p was the downstream target of CREB1, and CREB1 was posttranscriptionally regulated by miR-181a-5p. CONCLUSIONS: Our study identifies that the interaction loop between CREB1 and miR-181a-5p plays a crucial role in regulating the pathophysiologic features of FD BMSCs. MiR-181a-5p may be a potential therapeutic target for the treatment of FD.

The Caenorhabditis elegans RIG-I Homolog DRH-1 Mediates the Intracellular Pathogen Response upon Viral Infection.

Mammalian retinoic acid-inducible gene I (RIG-I)-like receptors detect viral double-stranded RNA (dsRNA) and 5'-triphosphorylated RNA to activate the transcription of interferon genes and promote antiviral defense. The Caenorhabditis elegans RIG-I-like receptor DRH-1 promotes defense through antiviral RNA interference (RNAi), but less is known about its role in regulating transcription. Here, we describe a role for DRH-1 in directing a transcriptional response in C. elegans called the intracellular pathogen response (IPR), which is associated with increased pathogen resistance. The IPR includes a set of genes induced by diverse stimuli, including intracellular infection and proteotoxic stress. Previous work suggested that the proteotoxic stress caused by intracellular infections might be the common trigger of the IPR, but here, we demonstrate that different stimuli act through distinct pathways. Specifically, we demonstrate that DRH-1/RIG-I is required for inducing the IPR in response to Orsay virus infection but not in response to other triggers like microsporidian infection or proteotoxic stress. Furthermore, DRH-1 appears to be acting independently of its known role in RNAi. Interestingly, expression of the replication-competent Orsay virus RNA1 segment alone is sufficient to induce most of the IPR genes in a manner dependent on RNA-dependent RNA polymerase activity and on DRH-1. Altogether, these results suggest that DRH-1 is a pattern recognition receptor that detects viral replication products to activate the IPR stress/immune program in C. elegansIMPORTANCEC. elegans lacks homologs of most mammalian pattern recognition receptors, and how nematodes detect pathogens is poorly understood. We show that the C. elegans RIG-I homolog DRH-1 mediates the induction of the intracellular pathogen response (IPR), a novel transcriptional defense program, in response to infection by the natural C. elegans viral pathogen Orsay virus. DRH-1 appears to act as a pattern recognition receptor to induce the IPR transcriptional defense program by sensing the products of viral RNA-dependent RNA polymerase activity. Interestingly, this signaling role of DRH-1 is separable from its previously known role in antiviral RNAi. In addition, we show that there are multiple host pathways for inducing the IPR, shedding light on the regulation of this novel transcriptional immune response.

Orsay Virus CP-δ Adopts a Novel ß-Bracelet Structural Fold and Incorporates into Virions as a Head Fiber.

Fiber proteins are commonly found in eukaryotic and prokaryotic viruses, where they play important roles in mediating viral attachment and host cell entry. They typically form trimeric structures and are incorporated into virions via noncovalent interactions. Orsay virus, a small RNA virus which specifically infects the laboratory model nematode Caenorhabditis elegans, encodes a fibrous protein δ that can be expressed as a free protein and as a capsid protein-δ (CP-δ) fusion protein. Free δ has previously been demonstrated to facilitate viral exit following intracellular expression; however, the biological significance and prevalence of CP-δ remained relatively unknown. Here, we demonstrate that Orsay CP-δ is covalently incorporated into infectious particles, the first example of any attached viral fibers known to date. The crystal structure of δ(1-101) (a deletion mutant containing the first 101 amino acid [aa] residues of δ) reveals a pentameric, 145-Å long fiber with an N-terminal coiled coil followed by multiple ß-bracelet repeats. Electron micrographs of infectious virions depict particle-associated CP-δ fibers with dimensions similar to free δ. The δ proteins from two other nematode viruses, Le Blanc and Santeuil, which both specifically infect Caenorhabditis briggsae, were also found to form fibrous molecules. Recombinant Le Blanc δ was able to block Orsay virus infection in worm culture and vice versa, suggesting these two viruses likely compete for the same cell receptor(s). Thus, we propose that while CP-δ likely mediates host cell attachment for all three nematode viruses, additional downstream factor(s) ultimately determine the host specificity and range of each virus.IMPORTANCE Viruses often have extended fibers to mediate host cell recognition and entry, serving as promising targets for antiviral drug development. Unlike other known viral fibers, the δ proteins from the three recently discovered nematode viruses are incorporated into infectious particles as protruding fibers covalently linked to the capsid. Crystal structures of δ revealed novel pentameric folding repeats, which we term ß-bracelets, in the intermediate shaft region. Based on sequence analysis, the ß-bracelet motif of δ is conserved in all three nematode viruses and could account for ∼60% of the total length of the fiber. Our study indicated that δ plays important roles in cell attachment for this group of nematode viruses. In addition, the tightly knitted ß-bracelet fold, which presumably allows δ to survive harsh environments in the worm gut, could be applicable to bioengineering applications given its potentially high stability.

Information transfer from the optical phase to a plasmonic digital encoder composed of a gold nanorod pair.

Small all-optical devices are central to the optical computing. Plasmonic digital encoders (PDEs) with a featured dimension of ∼1µm hold the key for transferring information from far field to photonic processing systems. Here we propose a PDE design composed of two gold nanorods (AuNRs), whose pattern represents 2-bit digital information. We implanted information into the spectral phase of a femtosecond pulse by pulse shaping and controlled the two-photon photoluminescence pattern of an AuNR pair. The high contrast ratios were achieved with 13.01 and 6.02 dB for binary codes "1-0" and "0-1", respectively.

Blood and Salivary MicroRNAs for Diagnosis of Oral Squamous Cell Carcinoma: A Systematic Review and Meta-Analysis.

PURPOSE: This meta-analysis aimed to compare and evaluate the diagnostic accuracy of blood and salivary microRNAs (miRNAs) in discriminating oral squamous cell carcinoma (OSCC). METHODS: The PubMed, Embase, Web of Science, and Cochrane Library were searched (updated to February 2020) to identify all articles describing the diagnostic value of blood and salivary miRNAs for OSCC. The pooled parameters were calculated using Revman (v.5.3) and STATA (v.14.0). RESULTS: Twenty articles involving 1,106 patients and 732 controls were included in this meta-analysis. The pooled sensitivity and specificity of salivary miRNAs were 0.70 (95% CI: 0.63-0.77) and 0.82 (95% CI: 0.72-0.90). For blood miRNAs, they were 0.79 (95% CI: 0.73-0.84) and 0.82 (95% CI: 0.77-0.86). The areas under receiver operating characteristic curve in saliva, blood, and body fluid miRNAs were 0.80 (95% CI: 0.77-0.84), 0.88 (95% CI: 0.84-0.90), and 0.87 (95% CI: 0.84-0.90), respectively. CONCLUSIONS: The results of this meta-analysis indicate a moderate diagnostic accuracy of blood and salivary miRNAs presented for OSCC. These findings may provide less invasive and relatively reliable diagnostic tools for OSCC detection.

CBCT study on the positional relationship between marginal points of pterygomaxillary junction and anterior nasal spine.

PURPOSE: This study aimed to locate the inferior end (Pti) and the superior end (Pts) of pterygomaxillary junction (PMJ) relative to anterior nasal spine (ANS) so as to provide references for pterygomaxillary separation. METHODS: The study was based on CBCT images of 109 Chinese patients. We projected Pti and Pts to the frontal plane and measured the distance as well as the positional relationship between the projection points and ANS via three-dimensional reconstruction image. RESULTS: On average, the ANS was 5.18 mm above the Pti and the horizontal distance between the Pti and ANS was 21.86 mm. The horizontal and vertical distances between Pts and ANS was 20.41 mm and 10.91 mm, respectively. The vertical height of PMJ was 16.09 mm. Scatter plots diagrammatic centered on ANS showed that 73% (160/218) Pti and 64% (140/218) Pts appeared in a 45° fan shape ranged from 20 to 25 mm radius in bilateral inferior and superior quadrant, respectively. There was no significant difference in the distance between both sides (P > 0.05). CONCLUSION: During the pterygomaxillary disjunction, it exists a risk of injuring neurovascular bundle of the pterygopalatine fossa 16.09 mm above the lowest border of the pterygomaxillary junction. The region within a 45° fan shape ranged in 20-25 mm radius in inferior quadrant centered on ANS might be suitable for the osteotome position. The positional relationship especially between the ANS and Pti found in this study provides a reference for surgeons during pterygomaxillary disjunction.

Development and validation of a seven-immune-feature-based prognostic score for oral squamous cell carcinoma after curative resection.

Immune infiltrates have been increasingly recognized as robust prognostic factors for human cancer. Here, we developed and validated a seven-immune-feature-based prognostic score (7IFBPS) for patients with oral squamous cell carcinoma (OSCC) after curative resection. Fourteen immune features regarding detailed locations and densities of seven types of tumor-infiltrating immune cells (TIIs) were characterized in clinical samples from 269 eligible patients in three independent cohorts by immunohistochemistry coupled with digital quantitation. Optimal cutoff values for individual immune features were yielded using X-tile software. The 7IFBPS was constructed by Kaplan-Meier and Cox regression model in training cohort and verified in testing, validation and combined cohorts. Concordance index (C-index), receiver operating characteristics and calibration curves were employed to define the performance of 7IFBPS in prognostic prediction. High CD3 IM (invasive margin), CD3 CT (center of tumor), CD8 CT, CD45RO IM, CD45RO CT, FOXP3 IM and FOXP3 CT significantly associated with improved survival. The 7IFBPS score was calculated using the formula: 1.041 × CD3 IM + 1.24 × CD3 CT + 1.701 × CD8 CT + 1.127 × CD45RO IM + 1.348 × CD45RO CT + 1.089 × FOXP3 IM + 1.483 FOXP3 CT. High 7IFBPS significantly associated with improved survival in all cohorts and served as an independent prognostic predictor. The C-index of 7IFBPS for predicting survival was 0.668 (95% CI, 0.609-0.726). Calibration curves for survival probability showed good agreement between prediction by 7IFBPS and actual observation. Collectively, our findings established the 7IFBPS as a novel powerful prognostic classifier for resectable OSCC. It holds potentials to be incorporated into current prognostic regime to better patient stratification.

Therapeutically targeting head and neck squamous cell carcinoma through synergistic inhibition of LSD1 and JMJD3 by TCP and GSK-J1.

BACKGROUND: The histone demethylase LSD1 is a key mediator driving tumorigenesis, which holds potential as a promising therapeutic target. However, treatment with LSD1 inhibitors alone failed to result in complete cancer regression. METHODS: The synergistic effects of TCP (a LSD1 inhibitor) and GSK-J1 (a JMJD3 inhibitor) against HNSCC were determined in vitro and in preclinical animal models. Genes modulated by chemical agents or siRNAs in HNSCC cells were identified by RNA-seq and further functionally interrogated by bioinformatics approach. Integrative siRNA-mediated gene knockdown, rescue experiment and ChIP-qPCR assays were utilised to characterise the mediators underlying the therapeutic effects conferred by TCP and GSK-J1. RESULTS: Treatment with TCP and GSK-J1 impaired cell proliferation, induced apoptosis and senescence in vitro, which were largely recapitulated by simultaneous LSD1 and JMJD3 knockdown. Combinational treatment inhibited tumour growth and progression in vivo. Differentially expressed genes modulated by TCP and GSK-J1 were significantly enriched in cell proliferation, apoptosis and cancer-related pathways. SPP1 was identified as the mediator of synergy underlying the pro-apoptosis effects conferred by TCP and GSK-J1. Co-upregulation of LSD1 and JMJD3 associated with worse prognosis in patients with HNSCC. CONCLUSIONS: Our findings revealed a novel therapeutic strategy of simultaneous LSD1 and JMJD3 inhibition against HNSCC.

Metformin promotes the osseointegration of titanium implants under osteoporotic conditions by regulating BMSCs autophagy, and osteogenic differentiation.

Osteoporosis is a common bone disorder with adverse effects on oral osseointegration, and the effects of metformin on bone metabolism have received increasing attention. The aim of the present study was to test the hypothesis that metformin promoted osteogenesis of bone mesenchymal stem cells (BMSCs) and osseointegration of titanium implants. BMSCs were treated with metformin to assess autophagic capacity, reactive oxygen species (ROS) production, anti-aging ability, and osteogenic differentiation. To determine its potential application in peri-implant of the maxilla, metformin was injected around the implant each day, immediately after the implant was embedded into the tooth socket. The results showed that metformin increased the autophagic capacity and decreased ROS production of osteoporotic BMSCs under hypoxia and serum deprivation (H/SD) culturing conditions. Metformin treatment significantly enhanced stemness properties and mineralized nodule formation, and increased the expression of osteogenic markers, including runt related transcription factor 2 (Runx2), osteocalcin (OCN), and alkaline phosphatase (ALP). Moreover, metformin substantially accelerated the formation of new bone, ameliorated the bone microarchitecture and promoted osseointegration of the dental implant. Collectively, metformin induces an osteogenic effect around the implant. Considering the widespread use of metformin, the results of the present study might promote a novel understanding of the positive effects of local metformin delivery on alveolar ridge defect, and have potential clinical application for the acceleration of osseointegration.